PMID- 19870488 TI - AN EPIDEMIC IN A MOUSE COLONY DUE TO THE VIRUS OF ACUTE LYMPHOCYTIC CHORIOMENINGITIS. AB - A filtrable virus, identical with that which causes acute lymphocytic choriomeningitis, has been found to cause a disease in white mice. Naturally infected mice usually show no symptoms, but such animals inoculated intracerebrally with sterile bouillon or other materials develop characteristic symptoms. The same symptoms are produced by intracerebral injection of the virus into mice from a disease-free stock. Guinea pigs are very susceptible and are therefore useful for detecting the virus and for neutralization tests. The disease in both naturally infected and inoculated animals is discussed and the pathological findings given. PMID- 19870489 TI - STUDIES ON MENINGOCOCCUS INFECTION : IX. STANDARDIZATION AND CONCENTRATION OF ANTIMENINGOCOCCUS HORSE SERUM (TYPE I). AB - Type I antimeningococcal horse sera have been standardized by the quantitative determination of their type-specific precipitin content. By a method involving dialysis and precipitation by treatment with carbon dioxide, the antibody in such sera has been purified tenfold with respect to the nitrogen content. PMID- 19870490 TI - STUDIES ON THE COMMON COLD : VI. CULTIVATION OF THE VIRUS IN TISSUE MEDIUM. AB - 1. Studies of the cultivation of the virus of common cold in tissue medium, and the capacity of the culture virus to induce infection in human volunteers are reported. 2. Detailed descriptions are given of the methods employed to isolate the virus, preserve and cultivate it, and to test its activity in human volunteers. 3. The virus of common cold can easily be isolated from properly selected patients and cultivated in tissue medium. 4. When kept in the original nasopharyngeal washings, the virus will survive at ice box temperature under anaerobic conditions for at least 13 days. 5. If the nasopharyngeal washings are frozen and dried in vacuo, the virus retains its activity for at least 4 months. 6. The virus of common cold has been proven to multiply in medium containing chick embryo tissue. Such cultures retain their capacity to produce typical infections in human beings for many transfers involving a period of several months. Attempts to cultivate the virus have been successful in seven out of eight instances. 7. Prolonged cultivation of the virus in tissue medium eventually leads to a loss of activity. 8. Strains of virus under cultivation maintain their potency best when transfers are made at 2 and 3 day intervals. 9. After removal from the incubator a culture of virus rapidly becomes inactive whether it be kept under seal in the ice box or frozen and dried in vacuo. 10. The destructive action of the medium can be prevented if the culture is mixed with gum acacia before freezing and drying in vacuo. PMID- 19870491 TI - STUDIES ON THE VIRUS OF INFLUENZA. AB - 1. Evidence is presented indicating the presence of a filtrable virus in the nasopharyngeal secretions of individuals suffering from influenza. 2. An attempt to transfer influenza from one human being to another by means of filtered nasopharyngeal washings resulted in the production in the inoculated volunteer of a common cold. 3. A filtrable agent has been cultivated in tissue medium from the filtered nasopharyngeal washings of patients with influenza. 4. Inoculation of the cultivated virus into human volunteers results for the most part in the production of a severe common cold with a tendency to pronounced constitutional reaction. 5. In one instance following inoculation of culture virus an infection clinically resembling influenza has been produced. 6. The more closely the source of the virus approached the type of epidemic influenza, the more likely the virus was to provoke constitutional symptoms. 7. The presence of certain pathogenic bacteria in the upper respiratory tract of inoculated individuals was not observed to modify the course or character of the experimental infection. 8. On prolonged cultivation the virus loses the capacity to infect human volunteers. PMID- 19870492 TI - RELATION OF THE HYPOPHYSIS TO THE SPLEEN : I. EFFECT OF HYPOPHYSECTOMY ON GROWTH AND REGENERATION OF SPLEEN TISSUE II. THE PRESENCE OF A SPLEEN-STIMULATING FACTOR IN EXTRACTS OF ANTERIOR HYPOPHYSIS. AB - 1. Removal of the hypophysis in adult rats is followed by progressive atrophy of the spleen. At the end of 2 months the ratio of spleen weight to body weight is one-half the normal. The administration of hypophyseal emulsion repairs to a considerable degree the atrophy of the spleen in such animals. 2. Hypophysectomy completely inhibits the regeneration of splenic tissue after partial splenectomy. Administration of anterior hypophyseal emulsion restores the regenerative capacity of splenic tissue of the hypophysectomized rat to the normal. 3. The daily administration of anterior hypophyseal emulsion of cattle or of alkaline extracts of fresh or acetone-dried anterior hypophysis during a period of 10 days in normal Bartonellacarrier or Bartonella-free rats results in hypertrophy of the spleen to twice normal size. Normal rats receiving emulsion during a period of 1 month become refractory to the spleen-stimulating effect. The spleen shows little increase in size above the normal at the end of this period. Injections of horse serum or of alkaline extracts of acetone-dried kidney, spleen or liver of cattle did not cause enlargement of the spleen of rats of Barlonella-free stock. 4. The increase in the size of the spleen, following daily administration of emulsion of the anterior hypophysis, is due primarily to a marked hyperplasia of the reticular and endothelial cells of the red pulp. The follicles also increase in size. Clusters of reticular cells containing numerous lymphoid elements appear throughout the splenic pulp. The reticular tissue of the bone marrow is similarly increased. There is a striking increase in the number of hemocytoblasts and megakaryocytes. The Kupffer cells are not affected. 5. The spleen-stimulating factor is not present in the acid extract of anterior hypophysis that contains thyrotropic and adrenotropic factors. It is present in some degree in an alkaline extract of fresh anterior hypophysis containing growth and gonadotropic factors. It is also present in alkaline extracts of acetone-dried anterior hypophysis relatively free from growth hormone. 6. The presence of a spleen-stimulating factor in the anterior hypophysis is suggested by these experiments. PMID- 19870493 TI - THE EFFECT OF COMBINATION WITH DIAZO COMPOUNDS ON THE IMMUNOLOGICAL REACTIVITY OF ANTIBODIES. AB - Sufficient coupling with any of five different diazo compounds eventually destroyed the reactivity of all the antisera here studied. The rates of inactivation varied considerably among the several antisera. By stopping the reaction at intervals, it was possible to prepare partially inactivated antibodies of peculiarly modified reactivity. Thus, the flocculating activity of diphtheria antitoxin with toxin was completely destroyed long before there was any demonstrable impairment of its protective titer in vivo. The first change induced in antipneumococcus horse sera was the apparently complete loss of reactivity with the capsular carbohydrate at a time when the agglutinating, animal-protecting and complement-fixing activity of the sera were only slightly affected. On further coupling, the sera no longer caused visible agglutination; but aggregation of the serum-treated bacteria could be induced by centrifugation. Still further coupling destroyed all antibody activity. Rabbit antisera to egg albumen and horse serum no longer precipitated the homologous antigen after treatment with diazo compounds, probably due to their failure to combine with the antigen. The hemolytic, complement-fixing and lipoid-flocculating activity of coupled rabbit antisera to sheep red blood cells fell off in parallel; the hemagglutinin seemed somewhat more resistant. The reagin of syphilitic serum was destroyed almost instantaneously by comparatively small amounts of diazo compounds. Finally, in the case of antityphoid agglutinin, the isoelectric point of the coupled antibody, measured on the surface of specifically sensitized bacteria, was found to shift from an original value of pH 4.7 to one of less than pH 2.7 as progressively more sulfanilic acid radicals added on to the antibody molecule. The groups in protein which participate in its reaction with diazo compounds probably include aliphatic amines, the imidazole ring of histidine, the indole group of tryptophane, the NH of proline and hydroxyproline and the phenyl group of tyrosine. Although it has been possible to modify antibodies chemically so that they combine with the corresponding antigens without causing their aggregation, the experiments here described furnish no indication as to which of these groups in antibody protein are primarily concerned in the antigen-antibody reaction, and which are responsible for the secondary flocculation. Such localization awaits the development of a technic for attacking individual groups in the protein molecule. PMID- 19870494 TI - NEUTRALIZATION TESTS WITH SERA OF CONVALESCENT OR IMMUNIZED ANIMALS AND THE VIRUSES OF SWINE AND HUMAN INFLUENZA. AB - Human and swine influenza viruses were regularly neutralized by their homologous immune sera. However, the sera of animals convalescent from infection with either the swine or human influenza virus possessed little, if any, neutralizing capacity for the heterologous virus. Hyperimmunization of animals against swine influenza virus tended to increase the neutralizing capacity of their sera for human influenza virus, but in an inconstant fashion, whereas repeated inoculations with human influenza virus frequently resulted in sera with strong neutralizing activities against swine influenza virus. These observations serve to emphasize both the immunological distinctiveness and the interrelationships of swine and human influenza viruses. PMID- 19870495 TI - THE INCIDENCE OF NEUTRALIZING ANTIBODIES FOR HUMAN INFLUENZA VIRUS IN THE SERUM OF HUMAN INDIVIDUALS OF DIFFERENT AGES. AB - The results of mouse protection tests with 136 human sera and a strain of human influenza virus are described. After the 1st year of life, the sera of approximately half the individuals tested contained sufficient antibody to furnish complete protection to mice. A much higher percentage of the sera obtained from individuals recently convalescent from influenza exerted a completely protective effect. On the other hand, certain sera protected only partially under the conditions of the tests. The results have been compared with those obtained by Shope in tests done with the same sera against swine influenza virus. The possible epidemiological significance of the results is discussed. PMID- 19870496 TI - THE INCIDENCE OF NEUTRALIZING ANTIBODIES FOR SWINE INFLUENZA VIRUS IN THE SERA OF HUMAN BEINGS OF DIFFERENT AGES. AB - Sera from a very high proportion of the human adults and new-born infants studied neutralized swine influenza virus; sera from children below the age of 12 years seldom exerted such an effect. The results of neutralization experiments with human sera and the virus of swine influenza have been compared with the outcome of similar tests with the virus of human influenza, and it seems evident that the presence of antibodies neutralizing swine influenza virus cannot be deemed the result of repeated exposures to the current human type of virus. From the known history of swine influenza and the similarity of its etiologic virus to that obtained from man it seems likely that the virus of swine influenza is the surviving prototype of the agent primarily responsible for the great human pandemic of 1918, as Laidlaw has already suggested. The presence in human sera of antibodies neutralizing swine influenza virus is believed to indicate a previous immunizing exposure to, or infection with, an influenza virus of the 1918 type. PMID- 19870497 TI - IMMUNOLOGICAL STUDIES WITH THE VIRUS OF INFECTIOUS LARYNGOTRACHEITIS OF FOWLS USING THE DEVELOPING EGG TECHNIQUE. AB - (1) The technique of chorioallantoic membrane inoculation has been applied to the study of the virus of infectious laryngotracheitis as it occurs amongst Australian poultry. (2) When suitably diluted suspensions of virus are inoculated, isolated foci or pocks appear whose macroscopic form and histological structure is characteristic. The numbers of these foci may be used as a measure of the amount of virus present. (3) Two distinct types of focus are produced by laryngotracheitis strains, one being characteristic of epizootic strains from New South Wales and from America, the other of a Victorian strain which is of very low virulence for fowls. (4) No qualitative antigenic differences can be detected amongst these strains but the epizootic strains are more readily neutralised by immune serum than the enzootic Victorian strain. (5) A study of the inactivation of the virus by immune serum shows that (a) the process of inactivation requires time for its completion in vitro; (b) the proportionate reduction in titre produced by a given concentration of antiserum is independent of the initial virus concentration; (c) reactivation by dilution is readily demonstrable; (d) virus in the presence of small concentrations of immune serum producing only a slight inactivating effect is rendered incapable of passing a gradocol membrane normally permeable to it; (e) the foci produced from partially neutralised virus suspensions are smaller than normal, suggesting delay in the initiation of foci. (6) These findings bring the neutralisation of a typical virus by immune serum completely into line with the phage-antiphage reaction as described by Andrewes and Elford. PMID- 19870498 TI - STUDIES IN SYNERGY : THE SYNERGIC ACTION OF STAPHYLOTOXIN AND BEEF LENS EXTRACT IN RABBITS. AB - The degree of immunization and sensitization of rabbits following injections of beef lens is markedly increased when the animals are under the influence of staphylotoxin. Since the effect of the latter is exerted when the two substances are introduced separately into the same tissues with several hours elapsing between injections, or into different veins, it appears that an intimate association of them is unnecessary. A stimulating action of the toxin on the antibody-forming cells is a more probable explanation of the phenomena observed. Animals actively immune to staphylotoxin fail to show any synergic effect of this toxin when introduced with beef lens. Neutralization of the toxin in vitro, on the other hand, fails to eliminate this stimulating effect. PMID- 19870499 TI - STUDIES IN SYNERGY : SYNERGIC STIMULATING EFFECT OF HYPERSENSITIVITY TO FOREIGN PROTEIN AND TO BACTERIA. AB - 1. The relative synergic stimulating influence of anti-horse serum sensitivity, non-hemolytic streptococcal hyperergy and staphylotoxin intoxication have been determined in connection with rabbits' reaction to simultaneous injections of lens extracts. These three synergic states are increasingly active in the order named. 2. Heterologous lens extract is a much more powerful antigen than is homologous lens, even under conditions where the reactivity of the immunized animal has been much enhanced. PMID- 19870500 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : II. THE IDENTITY OF PRECIPITIN AND AGGLUTININ. AB - 1. The absolute, quantitative agglutinin method has been used for the determination of the presence or absence of small amounts of specific polysaccharide in pneumococcus variants. 2. A technique is described for the removal of group specific antibody from antipneumococcus horse serum. 3. The type specific anticarbohydrate agglutinin and precipitin are not only present in identical amounts in Type I antipneumococcus horse serum, but a reduction in one is also accompanied by a quantitatively identical reduction in the other, providing evidence for their actual identity. In purified antibody solutions somewhat more agglutinin than precipitin is found, possibly owing to alteration of a portion of the antibody in the process of purification. PMID- 19870501 TI - ACTIVE IMMUNIZATION OF GUINEA PIGS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : II. IMMUNIZATION WITH FORMOLIZED VIRUS. AB - From a study by quantitative methods, the conclusion is reached that a resistance of high degree may be induced in guinea pigs and mice against experimental equine encephalomyelitis by means of formolized vaccines in which no active virus can be demonstrated. The induced resistance is not due to residual traces of active virus which might possibly have escaped detection in the formolized tissue preparations. PMID- 19870502 TI - INFECTION AND INTOXICATION : THEIR INFLUENCE UPON HEMOGLOBIN PRODUCTION IN EXPERIMENTAL ANEMIA. AB - Infection in human cases is often believed to be responsible for anemia. It is generally believed that lack of absorption and definite blood destruction are responsible for the anemia. Accelerated metabolism due to thyroid or dinitrophenol does not modify hemoglobin production in these standard anemic dogs. Endometritis lasting over many weeks will profoundly reduce the production of hemoglobin in the standard anemic dog. A sterile abscessalso will diminish the production of new hemoglobin in the anemic dog when liver is being fed but particularly during fasting periods when the usual abundant production of new hemoglobin is reduced to zero. Impaired absorption can be excluded as a factor of any significance in certain experiments given above. Destruction of red cells can likewise be excluded as of any significance in certain experiments given above. These experiments point to a disturbance of internal metabolism related to hemoglobin building in the body as responsible for the inhibition of hemoglobin production under these conditions. We believe this same factor is often of importance in human disease. PMID- 19870503 TI - THE EFFECT OF PROLONGED APPLICATION OF LARGE DOSES OF FOLLICULAR HORMONE ON THE UTERUS OF RABBITS. AB - Follicular hormone under physiological conditions produced hyperplasia of the muscular wall and proliferation of the mucous membrane of the uterus of rabbits. The following pathological changes were brought about by prolonged application of large doses of the hormone: (a) hyperaemia of the myometrium and the endometrium, with occasional scanty extravasal haemorrhages; (b) glandular-cystic hyperplasia of the endometrium; (c) infarct-like necrosis of the myometrium; (d) aseptic suppuration in the uterine cavity. These four processes can sometimes be found simultaneously in the same uterus, but they occur more frequently in sequence. While follicular hormone, applied in physiological doses, has a stimulating effect, prolonged application of large doses destroys the uterus. The effects described above were only to be observed in the rabbit, not in the rat. This illustrates the fact that hormone reactions may vary in different species. PMID- 19870504 TI - PROTHROMBIN DEFICIENCY THE CAUSE OF BLEEDING IN BILE FISTULA DOGS. AB - The bleeding tendency that develops in bile fistula dogs, completely or partially deprived of bile, is due to a prothrombin deficiency of the blood plasma. However, a relatively low prothrombin level may exist in these animals without the occurrence of spontaneous hemorrhage. The prothrombin level may remain within the limits of normal if sufficient bile has been fed. In these cases no disturbance in blood clotting occurs. PMID- 19870505 TI - STUDIES WITH HUMAN INFLUENZA VIRUS CULTIVATED IN ARTIFICIAL MEDIUM. AB - The in vitro cultivation of strains of human influenza virus has been successfully conducted through a prolonged series of successive transfers. The cultivated virus has retained the antigenic and immunological properties which characterized the animal passage virus from which it was derived. The culture virus is still virulent for mice and ferrets; it is capable of inducing an active state of immunity in animals vaccinated subcutaneously or intraperitoneally; it elicits specific neutralizing antibodies in the serum of infected or vaccinated animals. The virus has been successfully cultivated to date only in the presence of oxygen; when conditions of reduced oxygenation are imposed by the use of vaseline seal, with or without the addition of cystein, multiplication of the virus is not supported. On the other hand, it has been possible to cultivate the virus in the medium of Li and Rivers in ordinary test tubes. This affords a greatly simplified procedure, since the interval between transfers may be prolonged. The results of neutralization tests with various sera and the culture virus are presented and discussed. PMID- 19870506 TI - ON GROUP SPECIFIC A SUBSTANCES : III. THE SUBSTANCE IN COMMERCIAL PEPSIN. AB - A method of preparation and a preliminary chemical investigation of the substance present in commercial (pig) pepsin which reacts with human A antiserum are presented. The material offers especial advantage in securing in quantity a serologically highly active preparation suitable for further studies. Active preparations were isolated moreover from commercial (pig) gastric mucin. Some other materials showing group specific reactions are mentioned. PMID- 19870507 TI - QUANTITATIVE STUDIES ON THE PRECIPITIN REACTION : EFFECT OF SALTS ON THE REACTION. AB - 1. A quantitative study has been made of the effect on the precipitin reaction between the specific polysaccharide of Type III pneumococcus and the homologous antibody of salt concentrations ranging from O.1 M to 1.79 M, including the effect of ions of higher valence. 2. Within these limits, observed decreases in precipitated antibody with increasing salt concentration appear to be due to a decrease in the amount of antibody combined with the S III, rather than to an increase in solubility of the S III-antibody compounds. 3. The egg albumin antibody reaction is far less sensitive to changes in salt concentration than is the S III-antibody reaction. PMID- 19870508 TI - EXPERIMENTAL ENCEPHALITIS (ST. LOUIS TYPE) IN MICE WITH HIGH INBORN RESISTANCE : A CHRONIC SUBCLINICAL INFECTION. AB - 1. St. Louis encephalitis virus injected intracerebrally or intraperitoneally in maximum doses in resistant mice is distributed and is effective in a manner generally similar to that in susceptible mice. The minimum infecting dose is at least 1,000 times greater in resistant than susceptible mice and virus injected in the brain tends to remain at a relatively low titre, persist for a few days, and then disappear. 2. Virus dropped in the nares is demonstrable and progresses in the brains of resistant mice as in susceptible mice, but does not increase in titre beyond the 5th day, does not bring about fatal encephalitis, and persists for at least 4 weeks. 3. Lesions in the brains of resistant mice following nasal instillation of virus do not appear until the 8th day, reach a maximum at 40 days, and are still present, though resolving, at 3 months. The changes resemble those seen in the human disease and in other unnamed forms of encephalitis. 4. The quantity of virus drops 1,000-fold when recovered from resistant mice and becomes non-infective by the nasal route. Passage in susceptible mice promptly restores its full titre. PMID- 19870509 TI - PERSISTENCE OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS IN IMMUNE ANIMALS AND ITS RELATION TO IMMUNITY. AB - In some apparently healthy mice the virus of lymphocytic choriomeningitis persisted for a considerable period of time after recovery, in the blood, urine, and nasal secretions, while in other mice it soon became undemonstrable. It is possible that the persistence of the virus is due to lesions in the lungs, liver, and kidneys. The immunity to lymphocytic choriomeningitis in mice does not seem to depend upon the presence of virus in the blood and the organs tested. No antivirus was detected in sera from several solidly immune mice, which fact suggests that circulating antivirus plays no important part in their immunity. Leucocytes also seem to be no essential factor in this immunity, which probably is closely linked with the tissues. The urine of guinea pigs which had recovered from severe attacks of lymphocytic choriomeningitis contained virus for a few weeks after recovery, while that from mild cases contained no virus. Virus was never demonstrated in the blood of immune guinea pigs. Antivirus was readily detected in it. PMID- 19870510 TI - THE PROTECTIVE ACTION OF NASALLY INSTILLED IMMUNE SERUM AGAINST INFECTION WITH CERTAIN NEUROTROPIC VIRUSES BY WAY OF THE NOSE. AB - 1. Immune serum instilled intranasally in guinea pigs has protected them from infection with lethal amounts of pseudorabies virus by the nasal route. The same effect was obtained in mice with immune serum against the virus of equine encephalomyelitis (Eastern strain). 2. The protective effect of the immune serum in the nose begins at the time of instillation, is still evident 5 hours later, and usually has disappeared by the end of 24 hours. 3. Attempts to prolong the local effectiveness of immune serum by means of several devices were unsuccessful. 4. The action of the immune serum appears to be a local one in the nose, in view of the fact that the administration of even larger amounts of it intramuscularly failed to protect guinea pigs against infection with pseudorabies by the nasal route. PMID- 19870511 TI - PROTECTIVE ACTION OF CERTAIN CHEMICALS AGAINST INFECTION OF MONKEYS WITH NASALLY INSTILLED POLIOMYELITIS VIRUS. AB - In the present investigation evidence was obtained indicating that nasal instillations of suitable concentrations of sodium alum or tannic acid induce in Macacus rhesus monkeys resistance to the development of poliomyelitis when the virus is introduced by the nasal route. It was found that apparently different concentrations of these chemicals are required to exert this type of protective effect in different hosts or against different viruses, for while mice are readily protected against nasal infection with equine encephalomyelitis virus by 0.5 per cent solutions of tannic acid or alum (7), monkeys require at least 3 per cent solutions to become resistant against poliomyelitis. Experiments designed to elucidate the development of this refractory state in monkeys indicate that it is a result of the action of these chemicals not upon the virus but rather upon the tissues of the host (probably the olfactory mucosa); further evidence in favor of this hypothesis may be found in the observation that several days of treatment are required before resistance is induced. While one nasal instillation a day for 3 days proved effective when additional treatments were given on the days of virus administration, there was no protection against infection when the virus was given 48 and 96 hours after the last treatment. The resistance which was demonstrable when the virus was instilled intranasally on the 4th and 6th days after the beginning of treatment was also found to be present a week later when the treatments were given daily, indicating that the refractory state can be maintained in this manner. It was observed, however, that monkeys which were given nasal instillations of alum or tannic acid for 5 days or more may retain the resistance they acquired for 1 or 2 months without any additional treatment (Table V); thus, of 15 refractory monkeys retested after 1 month, 11 were still resistant; seven of 15 monkeys were refractory when retested after 2 months, while only one of 11 failed to develop poliomyelitis after an interval of 3 months. These last results suggest that to maintain such a refractory state over a period of months it may be necessary to employ daily instillations only for about a week, with subsequent repetitions at intervals of several days or a week. An experiment performed to determine the effect of beginning alum treatment soon after, rather than before, the virus is administered, indicated that there is no danger from a possible early or primary effect enhancing the invasiveness of the virus. One cannot state with any certainty, however, whether or not in some of the monkeys so treated the development of poliomyelitis is inhibited or prevented. Finally, it should be stressed that treatment with alum or tannic acid either completely prevented the disease in monkeys, or else was entirely without effect. It is therefore not surprising that no evidence was obtained of development of specific, active immunity in monkeys rendered refractory by chemical treatment. As far as could be ascertained, the nasal instillation of tannic acid or alum in man proved thoroughly innocuous beyond some local irritation for a short time. The desirability of testing this procedure as an aid in the prevention of poliomyelitis in man during the months of greatest incidence or during epidemics is quite apparent. In conclusion, there may be broader implications in this approach to the prevention of certain infectious diseases transmitted naturally or experimentally by way of the nose. It seems desirable to make studies with other viruses transmitted by the nasal route, including those of influenza and the common cold. The evidence obtained in the present study that the chemically induced refractory state may persist in a large number of monkeys for a month or two after treatment over a period of 5 days or more, suggests that studies on individuals who are subject to frequent attacks of common cold may perhaps be profitable. PMID- 19870512 TI - SOME EFFECTS OF OVARIECTOMY DURING THE PERIOD OF DECLINING REPRODUCTIVE POWERS IN MICE. AB - Cessation of breeding and castration of female mice approaching the period of declining reproductive power have at least two effects upon the subsequent life history of these animals. 1. The average expectation of life is appreciably increased. 2. The incidence of tumor is markedly decreased, especially in the older age groups. PMID- 19870513 TI - THE INFLUENCE OF INTRAUTERINE FACTORS ON THE FETAL WEIGHT OF RABBITS. AB - Observations were made on 475 fetuses carried by 71 pregnant rabbits. 63 or 88.7 per cent of the 71 does were sacrificed from 28 to 31 days after the last fertile mating, and these does bore 401 or 88.2 per cent of the total of 455 fully developed fetuses. The following information was available with reference to each fetus: age, weight, weight of corresponding placenta, horn, i.e., right or left, presentation, and position or order. The presentation indicated that part, head or breech, which was directed toward the vagina, and position or order, the relative locus of the fetus in the horn, the first position being that nearest the ovary. As the gestation period approached its normal limit of 31 days, the relative daily increase in mean fetal weight was progressively retarded. There was no significant difference between the number of fetuses in each uterine horn. Head presentation was significantly more frequent than breech, but the uterine horn in which the fetus was located had no influence on its presentation. A greater relative number of breech presenting fetuses was observed in the third position than in the other positions. Presentation did not exert a significant influence on fetal weight. Fetal weight at or near term was significantly influenced by the position or order in the uterine horn. In general, the weights of fetuses implanted high up nearest the ovary were greater than those developing nearest the outlet, and fetuses occupying intermediate positions had intermediate weights. When, however, only two fetuses were present in a horn, position had no effect on their weights. A significant positive coefficient of correlation was observed between fetal and placental weights. Moreover, placental weight was influenced by position in the uterine horn in exactly the same manner that fetal weight was so influenced. The factors which produced variability in fetal weight at or near term, did not account for the abnormally low birth weights of the dwarf rabbits observed in this laboratory. PMID- 19870514 TI - ON THE MECHANISM OF IMMUNITY IN TUBERCULOSIS : THE HOST-PARASITE RELATIONSHIP UNDER THE CONDITIONS OF A LOCALIZED AGAR FOCUS OF INFECTION AND THE GENERALIZATION OF THE DISEASE IN NORMAL AND IMMUNIZED RABBITS. AB - 1. There is an extracellular factor which inhibits the growth of tubercle bacilli in immunized rabbits. 2. Extracellular factors localize carbon particles, trypan blue and tubercle bacilli at the site of introduction to a greater extent in the immunized than in the normal animal. 3. This greater fixation is brought about by an increase in the density and extent of the fibrin barrier formed about the focus of the immunized animal. The more pronounced in vivo agglutination of tubercle bacilli and carbon particles in the vaccinated or tuberculous rabbit also tends to immobilize them in the tissues. 4. The growth inhibitory and localizing agents are effective in the fixation of small doses on reinfection at the portal of entry. 5. With large doses on reinfection, the increased lymph flow resulting from the intensified inflammation in the immunized animal brings about a more rapid dissemination of the bacilli to the draining lymph nodes than in the normal animal. 6. The most significant factor in immunity is the increased capacity of the rapidly mobilized mononuclear phagocytes to destroy tubercle bacilli. The impotent polymorphonuclear leukocytes quickly disappear from the site of reinfection. 7. The invading bacilli that reach the draining lymph nodes of the immunized animal are retarded in multiplication or destroyed by these phagocytes. 8. Vaccination of rabbits with BCG brings into play the factors tending to immobilize the bacilli of reinfection, inhibit their growth and destroy them with a resulting significant immunity. 9. A virulent primary infection affords a greater immunity than one of low virulence and the host reactions are expressed by a quantitative increase in those immunity factors which operate in a vaccinated animal. PMID- 19870515 TI - THE EFFECT OF AVITAMINOSIS-A ON THE PROSTATE. AB - 1. Vitamin A deficiency alone in the white rat is associated with atrophy of the testis and accessory sexual glands. This would appear to be indicative of some disturbance in the hypophyseal-gonadalprostatic hormonal relationships. All of the known vitamins necessary for the rat, except vitamin A, were present in the diet fed the animals studied. 2. Vitamin A deficiency in the rat is associated with foci of inflammation and epithelial metaplasia in the prostatic acini and vesicular ducts entirely similar to that reported in other organs. 3. Focal metaplasia and inflammation is occasionally encountered in the prostate of patients with extreme inanition associated with stenosis of the esophagus. It seems probable that this lesion is due to vitamin A deficiency. PMID- 19870516 TI - THE CULTIVATION OF TISSUES FOR PROLONGED PERIODS IN SINGLE FLASKS. AB - 1. Fragments of breast muscle from a 12 day old chick embryo have been kept alive in single flasks for an entire year without being transferred. The nutrient materials were supplied by frequent applications of adult fowl serum diluted with Tyrode solution. 2. When fragments of fixed tissues are cultivated in serum, cell multiplication and cell death are both reduced to an extremely low level. 3. The presence of a plasma coagulum is not essential to the continued survival and further development of tissues cultivated inserum. 4. The fibrinogen, prothrombin, and fibrin of coagulated plasma are not essential to the development of connective tissue fibers in vitro. PMID- 19870517 TI - THE FATE OF A VIRULENT HEMOLYTIC STREPTOCOCCUS INJECTED INTO THE SKIN OF NORMAL AND IMMUNIZED RABBITS. AB - 1. Hemolytic streptococci, highly virulent for rabbits, when injected into the skin of normal animals increased greatly in number at the site of injection during the first 12 hours, diminished somewhat after 24 hours but still persisted after 21 days. They produced large abscesses within 24 hours, there was ulceration, and healing occurred after about 5 weeks. Histological observations confirmed the bacteriological evidence that the streptococci underwent great multiplication at the site of their injection. 2. Virulent hemolytic streptococci injected into the skin of normal rabbits appeared in small numbers within 1 hour in the lymph nodes. As multiplication proceeded in the skin, hemolytic streptococci were found in large numbers from 1 hour to 7 days after inoculation in the inguinal lymph nodes. 3. Hemolytic streptococci were recovered from deeper lymph nodes, that is, from the iliac nodes, but only in animals of which the inguinal lymph nodes contained bacteria in relatively large numbers. 4. Virulent hemolytic streptococci injected into the skin of normal rabbits in some instances entered the blood stream in considerable number, and occasionally caused death with bacteremia. Streptococci were recovered more frequently from the spleen and were present in this organ only when they had been recovered from the deep (iliac) lymph nodes. 5. When virulent hemolytic streptococci were injected into the skin of immunized rabbits, in a few instances they increased in number for a short time, but usually diminished rapidly and had entirely disappeared in 48 hours. The gross lesions were smaller than in normal rabbits. There was more phagocytosis, and redness and edema had disappeared after 48 hours. 6. When virulent streptococci were injected into the skin of immune rabbits they passed to the regional lymph nodes in relatively smaller numbers than in the previously normal controls and appeared in these nodes in considerable numbers only in animals in which there had been conspicuous multiplication at the site of inoculation. No streptococci could be found in the iliac lymph node, blood or spleen. 7. Virulent streptococci injected into the skin of normal animals multiply actively, resist phagocytosis, invade the tissues widely, enter adjacent and distant lymph nodes and in some instances are distributed by the blood stream to internal organs. After immunization associated with some sensitization, virulent streptococci are more readily ingested by phagocytes, remain sharply localized, are rapidly destroyed, fail to pass the nearest lymph nodes and do not enter the blood stream. PMID- 19870518 TI - THE IMMUNOLOGICAL SPECIFICITY OF STAPHYLOCOCCI : IV. CUTANEOUS REACTIONS TO THE TYPE-SPECIFIC CARBOHYDRATES. AB - 1. Skin reactions to the type specific carbohydrates of Staphylococcus indicate that cutaneous sensitivity to Type B is either extremely rare or nonexistent. 2. Skin reactions to Type A carbohydrate occur in about 12 per cent of normal infants and children and in 65 to 70 per cent of normal adults. 3. Skin reactions to Type A carbohydrate occur regularly in patients with Staphylococcus infection. 4. Skin reactivity is not associated with demonstrable serum precipitins, for (a) normal individuals, though skin reactive, have not been found to possess them, and (b) not all patients with verified infection develop them. 5. The patients elaborating type specific precipitins, who numbered less than 30 per cent in this study, are those with severe, prolonged, or generalized Staphylococcus infection. 6. Specific carbohydrates have not been found in the urine of patients during Staphylococcus infection. PMID- 19870519 TI - EFFECT OF PURIFIED ENZYMES ON VIRUSES AND GRAM-NEGATIVE BACTERIA. AB - Evidence is presented that some viruses behave like proteins in that they are inactivated by proteolytic enzymes, whereas others prove more or less resistant. Ten strains of living Gram-negative bacteria resisted the action of purified trypsin and chymotrypsin, while the killed organisms were rapidly digested. Gram positive bacteria, on the other hand, were resistant whether living or dead. The findings are discussed. PMID- 19870520 TI - CHEMO-IMMUNOLOGICAL STUDIES ON CONJUGATED CARBOHYDRATE-PROTEINS : X. THE IMMUNOLOGICAL PROPERTIES OF AN ARTIFICIAL ANTIGEN CONTAINING GLUCURONIC ACID. AB - 1. Artificial carbohydrate-protein antigens containing the azobenzylglycosides of glucose and glucuronic acid give rise in rabbits to antibodies which are distinct and immunologically specific. 2. The artificial antigen containing glucuronic acid reacts in high dilutions in antipneumococcus horse sera Types II, III, and VIII. The chemical basis for this serological activity is discussed. PMID- 19870521 TI - AN AIR-DRIVEN ULTRACENTRIFUGE FOR MOLECULAR SEDIMENTATION. AB - Details of construction are given for an air-driven ultracentrifuge for molecular sedimentation. This instrument, like the standard oil-driven machine of Svedberg, uses rotors giving a 6.50 cm. radius of rotation and has cameras of great depth of focus. PMID- 19870522 TI - IMMUNIZATION EXPERIMENTS WITH SWINE INFLUENZA VIRUS. AB - 1. Swine influenza virus obtained from the lungs of infected ferrets or mice, when administered intramuscularly or subcutaneously, immunizes swine to swine influenza. 2. Ferrets, which have received subcutaneous injections of swine influenza virus obtained from the lungs of infected ferrets, are immune to intranasal infection with this virus. Similar injections with virus from the lungs of infected mice or swine do not immunize. 3. Mice can be immunized to intranasal infection with swine influenza virus by the subcutaneous injection of virus obtained from the lungs of infected mice, but not by similar injection with virus from the lungs of infected ferrets or swine. Repeated injections induce greater immunity than a single one. 4. Intraperitoneal inoculation of both mice and ferrets with swine influenza virus immunizes them to intranasal infection and it appears to make little or no difference whether the virus used as vaccine is obtained from the lungs of infected mice, ferrets, or swine. 5. Field experiments in which swine influenza followed the intramuscular administration of virus are cited as examples of the hazard involved in the use of this means of immunization in a densely crowded susceptible population. PMID- 19870523 TI - SEROLOGICAL REACTIONS WITH A VIRUS CAUSING RABBIT PAPILLOMAS WHICH BECOME CANCEROUS : I. TESTS OF THE BLOOD OF ANIMALS CARRYING THE PAPILLOMA. AB - A method has been devised for serological tests with a virus producing rabbit papillomas that become carcinomatous. The discrete character of the growths caused by the virus when suitably diluted fits it notably for quantitative experimentation. It shows no tendency to lie latent in domestic rabbits though it does so on occasion in cottontails, the natural hosts. Sera which partially neutralize it do not alter its character, or attenuate it, but merely cut down the number of its effective entities. The serum of normal domestic rabbits is ordinarily devoid of neutralizing influence on the virus, but that of animals carrying the papillomas usually exhibits neutralizing power soon after these appear. The rate at which this power increases depends in general upon the amount of papillomatous tissue developing, but exceptions to the rule occur, the presence of fairly large growths being compatible with a lack of such powers in demonstrable amount. Even when the antiviral power is great it has no evident influence on the course of established papillomas, other factors determining whether these enlarge or retrogress. It acts to prevent successful reinoculation of the animal, however. PMID- 19870524 TI - STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III : I. THE CAPACITY OF STRAINS OF PNEUMOCOCCUS TYPE III TO GROW AT 41 degrees C. AND THEIR VIRULENCE FOR RABBITS. AB - 1. A correlation appears to exist between the failure of certain strains of Pneumococcus Type III to grow at 41 degrees C. and their lack of virulence for rabbits. 2. It is likely that the capacity to grow at 41 degrees C.-an attribute constantly but not exclusively associated with strains of Pneumococcus Type III virulent for rabbits-is a prerequisite, but not the sole factor, in determining their virulence for these animals. PMID- 19870525 TI - SEROLOGICAL REACTIONS WITH A VIRUS CAUSING RABBIT PAPILLOMAS WHICH BECOME CANCEROUS : II. TESTS OF THE BLOOD OF ANIMALS CARRYING VARIOUS EPITHELIAL TUMORS. AB - The serum of a rabbit with large cancers resulting from the transplantation of a squamous cell carcinoma that had arisen from a virusinduced papilloma, possessed the power to neutralize the virus, and so too in less degree did that of an animal of the same transplantation series in which a small nodule had developed. The sera of rabbits carrying tar papillomas or the Brown-Pearce carcinoma proved wholly devoid of effect on the virus. The implantation of Brown-Pearce tumor material mixed with virus did not lead to an enduring establishment of the latter in the resulting growths, nor to any immediate changes in their morphological character. The significance of the facts is discussed. PMID- 19870526 TI - CHANGES IN THE BONE MARROW AND BLOOD CELLS OF DEVELOPING RABBITS. AB - 1. The full number of erythroid cells in the blood stream of the rabbit is reached by the 3rd week of life. 2. During this period, there is a predominance of erythrogenesis in the bone marrow. 3. During the 2nd week of life the bone marrow is in a state of hyperplasia owing to the needs of the body for blood and the small space available for the marrow. 4. This hyperplasia is reduced as the growth of the bone permits the marrow to spread. The control of the growth of the bones has an important bearing on hematopoiesis. 5. During the first 3 weeks of life, the chemical factors for the multiplication of red cells as well as for the elaboration of hemoglobin become available. 6. The amount of hemoglobin does not increase as rapidly as the number of cells, so that the macrocytic anemia of the fetus becomes reduced. The proportion of hemoglobin per red cell characteristic of the adult rabbit is reached by the 3rd month. 7. Further evidence on the intravascular origin of red blood cells is given. 8. The development of all of the white blood cells, with the exception of the monocyte, goes on at a slower rate than that of the red cells. 9. The monocytes reach their full number in the blood stream in the 1st week of life; granulocytes and lymphocytes by the 5th and 6th months. 10. Each of the three strains of white cells has a different rate of development. 11. The question as to whether the stem cell or primitive cell is identical with the lymphocyte is discussed. PMID- 19870527 TI - QUANTITATIVE STUDIES ON ANTIBODY PURIFICATION : I. THE DISSOCIATION OF PRECIPITATES FORMED BY PNEUMOCOCCUS SPECIFIC POLYSACCHARIDES AND HOMOLOGOUS ANTIBODIES. AB - 1. Quantitative data are given on the effect of changes in hydrogen ion concentration and of salt solutions of high concentration on certain immune precipitates obtained at lower salt concentration. 2. Advantage is taken of the shift in reaction equilibrium brought about by the salt in the case of pneumococcus carbohydrate-anti-carbohydrate precipitates to enable the preparation, in a single step from unconcentrated serum, of antibody solutions in which up to 93 per cent of the total nitrogen is immune nitrogen. The method permits successive absorptions of a serum to be made with the same specific precipitate. 3. A modification of Felton's alkaline earth hydroxide dissociation procedure is proposed which yields highly purified antibody with precipitates which have been subjected to several successive salt dissociations. PMID- 19870528 TI - SURVIVAL OF THE VIRUS OF POLIOMYELITIS IN THE ORAL AND NASAL SECRETION OF CONVALESCENTS. AB - The positive detection of the virus of poliomyelitis in the nasal secretions of 2 children, 16 and 13 days after the onset of the disease, is described. 7 animals which had been inoculated with other concentrates became ill with symptoms and temperature elevations suggestive of poliomyelitis, from 1 to 3 weeks following inoculation, but without definite paralysis. In 2 of these animals which were sacrificed, the histologic findings were compatible with the diagnosis of poliomyelitis but were not typical. Of the serums of the 5 remaining animals 4 failed to neutralize stock virus, whereas the serum of the fifth neutralized the virus on two different occasions. This serum was obtained from a monkey that had been inoculated with concentrated nasal secretions of a child 43 days after the onset of illness. It is suggested that the present quarantine period of 3 weeks is compatible with the available data. It is further suggested that the methods of procedure described may be useful in similar investigations. PMID- 19870529 TI - THE EPIDEMIOLOGY OF LYMPHOCYTIC CHORIOMENINGITIS IN WHITE MICE. AB - In a mouse colony in which lymphocytic choriomeningitis is endemic infection takes place either in utero or shortly after birth. Virus is discharged from infected mice with the nasal secretions and urine. In some mice the infection lasts for several months, and such carriers can transmit the disease to healthy mice by contact. The portal of entry appears to be the nasal mucosa rather than the gastrointestinal tract. Mice infected by contact show no definite symptoms while those infected in utero often do. The disease has persisted in the colony for at least 15 months without change in its character. Mouse stocks differ in their susceptibility to contact infection and the findings given in the paper could be reproduced only with a very susceptible stock. Wild mice (Mus musculus) can be infected by contact, although less easily than our white mice. The source of the infection in the colony has not been determined. The fact that the serum of the caretaker neutralizes the virus indicates that he has been infected. It seems likely that the virus went from him to the mice rather than vice versa. Other possible sources of infection are considered. PMID- 19870530 TI - THE COMPLEMENT FIXATION REACTION WITH PNEUMOCOCCUS CAPSULAR POLYSACCHARIDE. AB - 1. Complement is not fixed by immune aggregates resulting from the interaction of pneumococcus capsular polysaccharide and type-specific immune horse serum, although under proper conditions the substitution of immune rabbit serum gives positive results. 2. The negative results with immune horse serum are due to some poorly understood property of the specific antibodies rather than to some heterologous inhibitor present in the serum. 3. It has been shown that with immune rabbit serum-polysaccharide combinations, complement fixation is an adsorptive phenomenon conditioned upon the surface exposure of the immune aggregates. 4. A close parallelism to the selective adsorption of phosphatides by these immune aggregates has been pointed out. 5. In those instances in which complement is fixed this phenomenon must be regarded as tertiary and conditioned by (a) union of antigen and antibody, and (b) particulation. 6. The general significance of complement fixation as applied to bacterial polysaccharides has been discussed. PMID- 19870531 TI - ACTIVE IMMUNIZATION OF GUINEA PIGS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : III. QUANTITATIVE STUDIES OF SERUM ANTIVIRAL BODIES IN ANIMALS IMMUNIZED WITH ACTIVE AND INACTIVE VIRUS. AB - An analysis of the preceding experiments discloses that antiviral bodies are demonstrable not at all or in small amounts in the sera of guinea pigs injected with a quantity of active virus not sufficient to induce immunity against the described intracerebral test for induced resistance. However, neutralizing bodies are found in immune animals, although in low concentration, and are regularly manifested when serum is added to low multiples of infective doses of virus under optimal conditions of time and temperature. Hyperimmune serum, on the other hand, reveals a distinct increase in the amount of antiviral bodies present. Irrespective of the mode of procedure for revealing neutralizing bodies, there does not appear to be any notable difference in the content of such bodies in the serum of animals immunized with active virus or with formolized vaccine in which active virus could not be demonstrated. In other words, the antigenic complexes in active as well as in inactive virus produce similar degrees of antibody reaction. The formolization of virus tissue suspensions, therefore, can be considered as a process whereby the virus is inactivated but the antigenicity of the suspensions is preserved, as is also shown in the preceding paper of this series in tests on tissue immunity. In that article is described the remarkably high degree of tissue immunity which results from injections of inactive virus; now we demonstrate that this resistance is associated with a minimal degree of serum antibody. Finally, the question may well be asked, if practically no antiviral bodies are demonstrable immediately or soon after mixing immune serum and virus, and are recognizable in a tenfold increase when functions of time and temperature are brought into play, whether the bodies are "neutralizing" or the phenomenon is due merely to aggregation of virus particles by the serum. From the recent work on the same virus and immune serum (9) by Merrill, there appears to be warrant for the belief in aggregation of virus particles which in turn diminishes the virus activity to the indicated degree. PMID- 19870532 TI - ACTIVE IMMUNIZATION OF GUINEA PIGS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : IV. EFFECT OF IMMUNE SERUM ON ANTIGENICITY OF ACTIVE AND INACTIVE VIRUS. AB - A study was undertaken on the effect in vivo, in the guinea pig, of equine encephalomyelitis virus antiserum upon the antigenic response to active, as compared with that to formolized, inactive virus. It was found that when animals were given subcutaneously a proper amount of hyperimmune serum 1 hour before inoculation, in the subcutis, of either active or of inactive virus, no immunity was induced against an intracerebral test of more than 1,000 and less than 10,000 M.L.D. of virus. This preventive power of the serum was lost by its dilution, the loss being proportional to the dilution, and, on the other hand, more serum was needed to obtain the blocking effect as the quantity of virus was increased. When an insufficient amount of serum was introduced into the animals along with the same quantities of active virus or formolized vaccine, a certain number of those receiving the untreated virus succumbed to virus infection in the course of the inoculations, but the survivors were rendered resistant to the intracerebral test; all the guinea pigs treated with higher dilutions of serum and with formolized material were brought safely to an immune state. The point to be stressed then is that antigenic stimuli present in untreated active virus and in formolized virus tissue suspensions in which no active virus is demonstrable by drastic tests (1) and which are wholly noninfective in animals (1), are completely inhibited from acting by the use of proper amounts of immune serum. The mechanism underlying this preventive power of adequate amounts of serum may be explained on the basis of facts deduced in preceding papers of this series (1, 3) and in the present article. We have shown that 3 x 10(7) m.i.u. of active virus contains a sufficient amount of antigen to induce immunity without the necessity of its multiplication in the animal body. This has been fully established by the similar degree of resistance brought about by 3 x 10(7) m.i.u. of virus formolized to a degree in which no active virus could be revealed (1). The assumption that the blocking effect of serum in the quantity employed prevents multiplication of the virus which is reflected in the production of inadequate amounts of antigen, is therefore untenable, since this effect was obtained when a sufficient amount of antigen was present in "living" as well as in "killed" virus. On the other hand, with insufficient amounts of immune serum (to be noted in higher dilutions shown in Table II), only the active virus could multiply-the formolized vaccine was not affected in respect to its antigenicity by these quantities of serum-and so produce more antigenic substance. This substance, in turn, brought about greater resistance in the host. The precise action of proper amounts of serum in preventing development of immunity by both active and inactive virus is not definitely known. However, two hypotheses are offered for consideration: the first implies that the action of the serum is direct, that is, by entering into combination with the antigens to bar antigenic capacity; the second ascribes to the serum an indirect action, on the cells of the body, in such a way as to make them unable to react to the antigenic stimuli present in the inoculated materials. The identity of these antigenic stimuli in virus suspensions containing the active, infective agent or this agent inactivated by formalin is at the present time undetermined. If virus were obtainable in pure state, free from extraneous material, the answer to this question might be readily given, but it is quite a different matter when the substance called virus is a mixture of the infective agent, of inflammatory tissue products, of tissue, etc. We have, however, shown that induced immunity is not due to the presence of "living" virus, but whether the antigenic action originates from "killed" virus or from another constituent of the suspension is not clear. On the other hand, Sabin (7) suggests the possibility that the virus may not be the direct antigenic stimulus but that some substance on which it acts and which becomes liberated from infected cells may be the factor responsible. While this subject awaits the results of further study, we believe that formalin inactivates the infective agent in virus suspensions and preserves the antigenic component therein, whatever its nature may be. It would be of interest if this phenomenon of prevention of antigenic capacity by proper amounts of immune serum might apply to such materials which by their very nature do not multiply in the body of the host, e.g., toxin and antitoxin. Theobald Smith (8) and later Park (9) demonstrated that in mixtures of diphtheria toxin-antitoxin, when smaller amounts of immune serum (antitoxin) are used, the toxicity of the mixture is retained and immunity results; if the serum is increased, toxicity is reduced and immunity occurs irregularly, and if more serum is added, no toxicity nor immunity results. This is supported by the experiments of Hartley (10) on washed precipitates from underneutralized, neutral, and overneutralized mixtures of antitoxin and toxin: those derived from underneutralized material are toxic and powerfully antigenic; those from neutralized, atoxic and of good antigenic action, and from overneutralized, atoxic and of low antigenicity. Hartley states, moreover, that the precipitate reactions of toxicity and antigenicity bear a close relationship to the nature of the mixture from which they are produced. There is, therefore, a connection between the preventive reactions of the serum on the two forms of virus and of antitoxin on toxin in respect to toxicity and antigenicity. Furthermore, the toxin is rendered atoxic with retention of immunizing capacity by formalin: the production of toxoid or anatoxin (Glenny and Hopkins (11), Ramon (12))-again a condition related to the effects following formolization of the virus. It has, however, been stated that "in an immunizing mixture prepared with modified [formolized, but partially detoxified] toxin the antitoxin present does not within wide limits affect the antigenic power" (Glenny, Hopkins, and Pope (13)). It is not known whether a preliminary injection of antitoxic serum could have prevented the antigenic power of fully detoxified toxin, that is, after the passive immunity induced by the serum disappears. If a preventive action of antitoxic serum could be shown under these circumstances, a remarkable correlation of the reactions of proper amounts of antitoxin to toxoid and of proper amounts of immune serum on the virus would be evident. Finally, the inhibition of antigenic power of both active and inactive virus by immune serum has been demonstrated to apply to the virus of equine encephalomyelitis in guinea pigs and no generalizations of the application of the phenomenon to other viruses are intended. PMID- 19870533 TI - STUDIES ON THE SUPRARENAL CORTEX : V. THE INFLUENCE OF THE CORTICAL HORMONE UPON THE EXCRETION OF WATER AND ELECTROLYTES IN THE SUPRARENALECTOMIZED DOG. AB - 1. The withdrawal of maintenance injections of the cortical hormone from the suprarenalectomized dog during balance experiments, in which a constant meat diet is given, with constant fluid and salt intake, is followed by increased urinary loss of sodium and chloride, and by retention of potassium and nitrogen. 2. Where the water intake is low, a definite diuresis usually accompanies this excretion of sodium and chloride, but where fluids are forced, no diuresis may be observed. 3. The reinjection of the cortical hormone in suprarenal insufficiency causes an active renal excretion of potassium which is greatly in excess of the probable extra accumulation of this component in the extracellular fluids during the period when insufficiency is developing. This potassium excretion is surmised to be sufficient to account for such an accumulation, if diffusible potassium is present in like concentration equally throughout all of the body water, intracellular as well as extracellular. The excretion of potassium is accompanied by a. corresponding excretion of phosphate and of nitrogen. 4. The excretion of electrolytes which is associated with withdrawal and with subsequent reinjection of suprarenal cortical hormone differs from the effects produced with various diuretic agents regarding which data are available. The effects produced by injection of the cortical hormone during suprarenal insufficiency, however, do resemble those produced with pituitrin, particularly in the greatly increased excretion of potassium relative to sodium, and in the coincidental dilution of the circulating blood. They suggest the possibility that the two similar effects may be ascribable to a common cause. PMID- 19870534 TI - CHANGES IN OUTLYING BONE MARROW ACCOMPANYING A LOCAL INCREASE OF TEMPERATURE WITHIN PHYSIOLOGICAL LIMITS. AB - A great difference exists in the adult bone marrow of central bones as compared with outlying bones of the mammalia and avia, the distal bones being at a great disadvantage from the standpoint of blood cell production. Several experimental procedures are reported by which this disadvantage is overcome and in consequence fatty marrow of outlying bones is replaced by red marrow occurring chiefly at the epiphyseal regions, unless a low oxygen stimulus is also provided when marrow of the diaphysis becomes involved. A common factor in all of the experiments was an elevation of temperature beyond that prevailing in these distal regions, and it is felt that the evidence warrants the opinion that the cause of improvement is thermal. In some experiments, blood cell formation was increasing while the heat was adversely affecting the testis. The experiments permit construction of a general theory of fat distribution in bone marrow. In certain grafts of precartilage to other rats, normal differentiation into bone, cartilage, and marrow occurred, while in others cartilage and very small amounts of primitive marrow developed with slight, or no bone formation. Cartilage was always successfully engrafted. The capacity to form sinusoids in bone marrow is determined by the nature of the tissue rather than by the ingrowing endothelium. PMID- 19870535 TI - AN INCREASE IN RETICULO-ENDOTHELIAL CELLS IN OUTLYING BONE MARROW CONSEQUENT UPON A LOCAL INCREASE IN TEMPERATURE. AB - In adult mammals and birds there is a great quantitative difference in the reticulo-endothelial system content of the bone marrow of central bones as compared with distal outlying bones. Experimental procedures reported in the accompanying communication effecting development and increase of hemopoiesis in inactive yellow marrow also effect a reticulo-endothelial cell increase. PMID- 19870536 TI - STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III : II. CERTAIN DISTINGUISHING PROPERTIES OF TWO STRAINS OF PNEUMOCOCCUS TYPE III VARYING IN THEIR VIRULENCE FOR RABBITS, AND THE REAPPEARANCE OF THESE PROPERTIES FOLLOWING R-->S RECONVERSION OF THEIR RESPECTIVE ROUGH DERIVATIVES. AB - The results which have been presented show that under the conditions of artificial cultivation at 37 degrees C. definite differences exist between two smooth strains of Pneumococcus Type III both of which are highly virulent for mice by the intraperitoneal route, but which may be sharply distinguished in their virulence for rabbits. These differences consist in the size of the fully developed intact capsule and the interval of time required for its loss. The somewhat smaller capsule of the avirulent strain, well formed and easily demonstrable during the early period of growth, diminishes quickly, while the large capsule of the strain virulent for rabbits is retained for a considerably longer period. Closely correlated with the time at which this reduction of capsule occurs is the appearance of changes in the surface properties of the bacteria which are revealed by a shifting of the range of acid agglutination, susceptibility to clumping in anti-R serum and ingestion by normal adult human polymorphonuclear leucocytes and serum. Since it has been shown that these alterations as growth continues, result in a loss of characteristics which distinguish the strictly type specific, fully capsulated pneumococcus and ultimately lead to a state temporarily approximating that of the completely avirulent R form, and since under the experimental conditions they are inaugurated sooner, advance more rapidly and are more complete in the rabbit avirulent organism, we believe that they may partly account for difference in rabbit virulence of the two strains. In the following paper an attempt has therefore been made to correlate this behavior in vitro with the events attendant upon inoculation into the animal body. The studies of Clark and Ruehl (16), Henrici (17), Bayne-Jones and Adolph (18) and others have demonstrated a marked increase in the size of the bacterial cell associated with the early phases of growth. These authors have dealt chiefly with noncapsulated rod forms and even Clark and Ruehl who included cultures of various cocci do not make reference to variations in capsule size. Recently Seastone (19) has called attention to the large volume occupied by young capsulated streptococci. Similarly we have found that increase and decrease of Pneumococcus Type III volume appears to be due largely to the formation of capsule in young cultures and its subsequent loss as the organisms age. Because of the relatively great proportion of capsule in comparison with soma, a greater disparity exists between the volume of young and old pneumococci than that found by those who have studied bacteria lacking this structure. Of interest in connection with our observations are those of Preisz (20) on the nature of the capsules of virulent anthrax bacilli and strains attenuated by cultivation at 42.5 degrees C. The latter produced soft, rapidly dissolving capsules while such structures in the former were characteristically firm and were retained by the bacilli for longer periods. This worker also noted in confirmation of the earlier work of others, that the capsules of B. anthracis are lost during the course of growth in serum media and in the subcutaneous tissues of the susceptible mouse. We have demonstrated that the R variants derived under the same conditions from the two smooth strains of Pneumococcus Type III reveal certain characteristics by which they may be distinguished from each other in respect to cell and colony morphology, growth in broth, as well as growth at 41 degrees C. (cf. Paper I). By employing the method of Griffith, these two R variants have been induced to revert to the S form. Following the injection into mice of the various possible combinations of living R variant and the killed S organisms of either rabbit virulent or avirulent strain, as well as very large numbers of the R variant alone, S forms emerged which in their various attributes, notably that of virulence for rabbits, resembled the original smooth strain from which the particular R variant involved was dissociated. The function of the smooth killed organisms in the process of transformation appeared to be only that of a stimulus toward reversion to the S. They apparently play no role in determining the virulence or the growth properties of the resulting S form. These observations indicate that the factors involved in virulence are conditioned by stable physiological properties peculiar to the individual strain and that although temporarily inactive during the R state, they are again resumed unaltered upon the transition to the S form. They serve also to reemphasize the fact, apparent from several studies but perhaps not sufficiently realized, that the R variants of the pneumococcus, even though obtained under the same conditions from the same type but from different strains, may vary definitely in their various attributes. Finally, they strongly suggest that the degree of virulence of a given strain of a bacterial species may be determined not only by its ability to multiply in the environment of the host and to synthesize certain substances of definite chemical and antigenic properties, but also by the capacity to elaborate these in greater or lesser degree and under the conditions of parasitism within the animal body to maintain them in contact with the soma of the cell in such state that they afford an efficient barrier to the defensive mechanisms of the host. PMID- 19870537 TI - STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III : III. CORRELATION OF THE BEHAVIOR IN VIVO OF PNEUMOCOCCI TYPE III VARYING IN THEIR VIRULENCE FOR RABBITS WITH CERTAIN DIFFERENCES OBSERVED IN VITRO. AB - AMONG THE EXPERIMENTAL FINDINGS REPORTED IN THIS PAPER TO WHICH WE WISH TO GIVE PARTICULAR EMPHASIS ARE THE FOLLOWING: 1. The results which follow the intravenous injection into rabbits of two strains of Pneumococcus Type III of different degrees of virulence vary with the state of the capsule. Thus when this structure is completely developed both remain in the blood. A culture of either strain begins to become susceptible to the blood-clearing mechanism contemporaneously with the onset of capsular degeneration and the initiation of other concomitant changes at the surface of the organism (cf Paper II), which occur much earlier with the less virulent strain. 2. When, in either case, removal from the blood stream occurs, this is effected by the phagocytic cells of the body. There is no suggestion that a new or unknown mechanism is involved. The greatest share of the burden is borne by the fixed phagocytic cells of the liver and spleen, and to a less extent by those of the lung and bone marrow. Nevertheless, it has been demonstrated that the polymorphonuclear leucocytes may also participate. 3. Phagocytosis by the leucocytes of the normal animal either in intro or in vivo has been observed only at such a time as the capsule has become impaired. Ingestion of the organisms by the fixed tissue cells appears also to be effective only under the same condition and is accordingly observed with much younger cultures of the less virulent strain. 4. Following their removal from the blood and their accumulation within the fixed phagocytes of the organs, destruction of most of the cocci proceeds within 2 to 4 hours. Both strains are destroyed provided they are in the state favorable to phagocytic attack. 5. Evidence has been presented which indicates that just as in vitro, so in a local area of inflammation within the body, aging with attendant capsular loss and increasing susceptibility to phagocytosis may take place. 6. With organisms from either strain a variable period of lag follows their injection into the blood stream, even when they are introduced in a state of active multiplication and complete encapsulation. 7. Differences in virulence for rabbits of two strains of Pneumococcus Type III do not imply that this animal possesses a defensive mechanism which is absent in other species, since it has been possible to demonstrate similar differences when the organisms are injected intravenously into mice. This fact indicates that the factors determining the degree of virulence of these strains are to be sought in the organisms themselves, rather than in the kind of host. PMID- 19870538 TI - AN UNSATURATED FATTY ACID FRACTION OF PIG PANCREAS WHICH INHIBITS THE GROWTH OF CHICKEN SARCOMA. AB - The inhibiting action of pancreatic tissue was found to be associated with the unsaturated fatty acid fraction. As small an amount of fatty acid as 0.1 mg. inhibited the chicken sarcoma agent contained in 0.2 cc. of a 1:60 aqueous extract of Chicken Tumor I. The unsaturated fatty acid had an acid number and an iodine number similar to those for oleic acid. Commercial oleic acid also was found to inhibit the growth of the chicken sarcoma in comparable quantities. PMID- 19870539 TI - TISSUE CULTURE STUDIES ON BACTERIAL HYPERSENSITIVITY : I. TUBERCULIN SENSITIVE TISSUES. AB - 1. A high degree of cellular sensitivity to tuberculin toxicity was demonstrated when explants from tuberculous animals were grown in media containing that substance. 2. Similar degrees of sensitivity were noted in cells derived from animals infected with either virulent or relatively lowly virulent strains of tubercle bacilli. 3. The specificity of the tuberculin cytotoxicity was proven by testing with other bacterial cytotoxic materials. 4. Tuberculin sensitive cells grown in vitro in normal media showed, when tested with tuberculin, persistence of this cellular sensitivity through several transplantations during which time many new generations of cells developed. 5. There was a depression of the initial growth energy of explants from animals during the toxic phase of the disease. During the healing stage the initial growth energy returned to normal although marked sensitivity to tuberculin persisted. 6. The degree of cellular sensitivity to tuberculin in vitro did no parallel the acuity of the infectious process but represented a more or less permanent acquired characteristic impressed on the cell as a result of the infection. PMID- 19870540 TI - TISSUE CULTURE STUDIES ON BACTERIAL HYPERSENSITIVITY : II. REACTIONS OF TISSUES FROM GUINEA PIGS INFECTED WITH GROUP C HEMOLYTIC STREPTOCOCCI. AB - 1. Guinea pigs infected with naturally pathogenic hemolytic streptococci (group C Lancefield) develop a low grade chronic type of disease characterized chiefly by purulent lymphadenitis. 2. Cutaneous hyperreactivity to a crude streptococcal extract invariably occurred during the course of this infection. 3. Production of antibodies (precipitins and agglutinins) was studied. 4. The hemolytic streptococcal extract had a specific toxic effect, when tested in vitro, on cells from infected animals; this was shown by microscopic evidence of cellular injury, and by quantitative inhibition of cellular migration and growth. The specificity of the reaction was proven by testing with other cytotoxic substances. 5. There was no parallelism between skin hypersensitivity and humoral antibody titer. 6. There was no correlation between the degree of skin reactivity to the bacterial extract and the degree of sensitivity of splenic cells to the toxic action of the same extract in vitro. 7. Comparison of cellular sensitivity to tuberculin with cellular sensitivity to streptococcal extract in cultures of guinea pig tissues showed that the former was more intense and was more persistent on prolonged growth in vitro. PMID- 19870541 TI - THE PROTECTIVE ACTION OF TYPE I ANTIPNEUMOCOCCUS SERUM IN MICE : IV. THE PROZONE. AB - 1. Type I antipneumococcus horse serum, in amounts exceeding a characteristic optimum, fails to protect mice against infection with the homologous type pneumococci. This failure is due to a marked inhibition of the phagocytic mechanism in the earlier stages of the infectious process. On the other hand, antipneumococcus rabbit serum in similar quantities does not inhibit phagocytosis, nor does it block the protection. 2. The experimental evidence suggests that the prozoning action of immune horse serum is due primarily to some characteristic property of the specific antibody and secondarily to an heterologous component of the serum, ineffective in itself but acting through the mediation of the antigen-antibody combination. This secondary factor may be a lipid. PMID- 19870542 TI - THE PROTECTIVE ACTION OF TYPE I ANTIPNEUMOCOCCUS SERUM IN MICE : V. THE EFFECT OF ADDED LIPIDS ON THE PROTECTIVE MECHANISM. AB - 1. The addition of small amounts of cholesterol and of cephalin reduces markedly the protective action of antipneumococcus horse serum. 2. These lipids do not affect the protective action of antipneumococcus rabbit serum. 3. These findings may be explained (a)by the selective adsorption of lipid on the antigen-antibody complex, and (b) by certain lipid antagonisms. 4. The failure of large amounts of immune horse serum to protect mice against pneumococcus infection is explicable on the basis of selective participation of lipids dependent upon the species from which the antibody is derived. 5. The lipids modify the results of protection tests only through participation in the process of specific sensitization. PMID- 19870543 TI - OBSERVATIONS ON THE RELATION OF THE VIRUS CAUSING RABBIT PAPILLOMAS TO THE CANCERS DERIVING THEREFROM : I. THE INFLUENCE OF THE HOST SPECIES AND OF THE PATHOGENIC ACTIVITY AND CONCENTRATION OF THE VIRUS. AB - All the strains of the Shope virus thus far tested which give rise to vigorous, progressively enlarging papillomas in domestic rabbits, function as carcinogenic agents by way of these growths. The more pathogenic the virus as evidenced by the brevity of its incubation period and the vigor of the papillomas produced, the sooner and oftener does cancer occur. The number of virus entities contained in the inoculum notably influences the outcome, cancer appearing most frequently in those confluent, papillomatous masses which have resulted from the greatest concentration of the virus material under test. The papillomas experimentally induced by the ordinary inoculation methods are essentially aggregates of proliferating cell families, each the outcome of some primary cell-virus association. Some of these associations are followed more frequently by cancer than others are in the same animal. Cottontail rabbits, the natural hosts of the virus, are notably resistant to its sustained activity, as compared with domestic rabbits. Though often growing rapidly at first, the papillomas of cottontails soon become relatively inert in most cases, and they usually retrogress, and rarely undergo malignant change. In an instance here reported both a squamous cell carcinoma and a metastasizing sarcoma appeared at the base of some papillomas due to experimental inoculation, which had existed on the ears of a cottontail for nearly 2 years. The meaning of the phenomena is discussed. PMID- 19870544 TI - OBSERVATIONS ON THE RELATION OF THE VIRUS CAUSING RABBIT PAPILLOMAS TO THE CANCERS DERIVING THEREFROM : II. THE EVIDENCE PROVIDED BY THE TUMORS: GENERAL CONSIDERATIONS. AB - The papillomas caused by the Shope virus sometimes grow down spontaneously into the subcutaneous tissue and extend along the lymphatics in the same way as do many cancers of the human breast. They may even invade the voluntary muscle under such circumstances, taking on an aspect suggestive of squamous cell carcinomatosis, but ultimately they differentiate in the way characteristic of the papilloma. Slight operative interferences with papillomas may be followed by a development of secondary nodules in the lungs. These result from cell emboli, and the same local conditions determine their fate as are effective in the case of emboli composed of human cancer cells. The virus-induced papilloma is not only a neoplasm in its immediate aspect and habit but sometimes one that verges upon malignancy. The tumors, including the cancers, which eventually derive from it in favorable hosts, are representative of more than a mere enhancement of the activity of the growth. They develop within a relatively brief period of time but only after the papilloma has grown for a long while; and they are morphologically various whereas the parent tumor is remarkably constant in its form. Some of the new growths differ but little from the papilloma, however, even when possessed of the ability to metastasize, and many continue to be influenced by the virus. The Shope virus is heavily conditioned in its carcinogenic activity, yet it is the nearest cause for cancer now known. PMID- 19870545 TI - STUDIES ON NATURAL IMMUNITY TO PNEUMOCOCCUS TYPE III : IV. OBSERVATIONS ON A NON TYPE SPECIFIC HUMORAL FACTOR INVOLVED IN RESISTANCE TO PNEUMOCOCCUS TYPE III. AB - Since there is no evidence for the occurrence of type specific antibody in the normal rabbit and since, as we have shown, the Pneumococcus Type III whether avirulent or virulent is not removed from the blood stream or destroyed when the capsule is intact, the following factors which have been revealed in the course of our work appear to represent certain essential components, if not the complete mechanism, upon which the natural immunity of the rabbit against this organism depends. (a) The elevation of the body temperature after intravenous infection to 41 degrees C. or thereabouts and its maintenance for varying periods. (b) The ability of the phagocytic cells, both fixed and mobile, to attack any cocci which have become vulnerable through the deterioration of capsular integrity. (c) The adjuvant effect of an antibody, reacting with the somatic C carbohydrate, which enhances the phagocytosis of such organisms as no longer possess a completely intact envelope. Conversely, the varying degrees of virulence for rabbits observed among Pneumococcus Type III strains are based upon: (a) differences in the ability of the organisms to multiply at the elevated temperatures encountered in the infected host. Strains markedly susceptible to the harmful influence of this factor fail to induce a generalized fatal infection. Not all "thermo resistant" strains are highly virulent, however, and these may contrast sharply with regard to (b) size of the capsule and the ease with which it is impaired or completely lost. The capsules must be maintained intact for a sufficient time until multiplication of the organisms can proceed to such a degree that death of the host results. Avirulent strains even when capable of growth at 41 degrees C. appear to be unable to satisfy this requirement. The differences in virulence of various strains apparently conditioned by these factors are not limited solely to the case of the rabbit, since for at least two strains similar differences in virulence have been shown to exist when the intravenous route of infection is employed in mice. PMID- 19870546 TI - IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS : IV. STATISTICAL STUDIES OF ELEMENTARY BODIES IN RELATION TO INFECTION AND AGGLUTINATION. AB - Methods have been described by which the number of elementary bodies present in a suspension can be estimated. It has been shown that by means of replicate counts, in which the Petroff-Hausser chamber was used, a high degree of accuracy can be attained. By means of the Gates densitometer, the number of elementary bodies in a suspension can be determined with a coefficient of variation of about 3.0 per cent. A method has been described by which the accuracy of estimation of the infectious titer of a suspension can be increased without greatly enlarging the number of animals employed. This consists of selecting as the end-point that dilution of virus which on intradermal inoculation in a rabbit would lead theoretically to an equal number of positive and negative results. The statistical advantages of this method have been confirmed by the experiences of other laboratories. By the application of the methods described, there was shown to be a direct correlation between the number of elementary bodies and the number of infectious units of virus present in a given suspension. At the mean of the distribution this ratio is as the logarithms 9.62 to 8.0. To extrapolate this curve, in order to determine the number of elementary bodies present in a single infectious unit, while tempting, is probably not justifiable. It must likewise be remembered that the data given apply to a particular strain of vaccine virus, and that the number of infectious units has been determined by intradermal inoculation of rabbits. It appears also that this method may be of value in studies of the virulence of different strains of vaccine virus, since by its application one may determine not only the infectious liter of a suspension, but its content of elementary bodies. In the agglutination reaction it was found that optimum titers of serum were obtained when the test antigen contained from 2.0 x 10(9) to 1.05 x 10(10) elementary bodies per cc. Approximately 1.95 x 10(8) particles per cc. of suspension were required for the production of visible agglutination. PMID- 19870547 TI - THE HEMOCYTOLOGICAL CONSTITUTION OF ADULT MALE RABBITS FROM FIFTEEN STANDARD BREEDS. AB - A study of the red blood cells, hemoglobin, blood platelets, and the total and individual white blood cells was made on 180 male rabbits of known age and representing fifteen standard breeds. An attempt was made to eliminate or bold constant such variables as age, sex, season, time of examination, technical errors, food, housing, and disease. The mean, variance of the mean, and standard deviation were calculated for each breed sample and for the group as a whole. An analysis of the variance showed that the variation between the breed samples was significantly greater than the variation within the breed samples for the red blood cells, hemoglobin, blood platelets, total white blood cells, basophiles, eosinophiles, and lymphocytes per cubic millimeter and in per cent and the neutrophiles in per cent. No significant variations were detected in the monocytes except when the breeds were divided into heavy and light breeds. No variation in the neutrophiles per cubic millimeter was detected; a large number of the breeds had exactly the same mean neutrophile level. Characteristic blood formulae were found for the various breed samples having an adequate numerical representation. It was concluded that the varying blood formulae could not be explained on any other, except an hereditary (genetic) basis. PMID- 19870548 TI - NITROGEN, POTASSIUM, SODIUM, AND CHLORINE METABOLISM IN RICKETS, WITH SPECIAL REFERENCE TO BILIARY FISTULA RICKETS IN PUPPIES. AB - 1. Rickets developed in three puppies deprived of vitamin D and sunlight since birth, in which, at the age of 6 to 7 weeks gall bladder fistula was established. The results of studies of their bones and of the calcium and phosphate metabolism have previously been published (2). Studies on the nitrogen, potassium, sodium, and chlorine metabolism, here presented, reveal that the metabolism was greatly interfered with as compared with that in three controls without gall bladder fistula rickets. This interference, together with an inhibited gain in weight, demonstrates that the pathogenesis of biliary, fistula rickets in puppies has to be considered distinctly different from infantile rickets as well as from rickets produced in rats. 2. The nitrogen, potassium, sodium, and chlorine metabolism was also studied in three rachitic and four healthy infants, and in eleven rachitic and six control rats. The balance of these substances, as well as their distribution in stool and urine, proved to be the same whether or not rickets was present. 3. The pathogenesis of biliary fistula rickets is discussed on the basis of these studies. The assumption has been made that deficiency in other vitamins than vitamin D might have a bearing upon the development of this disease. Further study with a view to possible elimination of these unspecific factors might lead to the experimental production by gall bladder fistula of a purely rachitic state. 4. The normal balance and distribution of nitrogen, potassium, sodium, and chlorine in the stool and urine of rachitic infants and rats are considered further evidence of the hypothetical nature of the so called absorption theory in infantile rickets. PMID- 19870549 TI - STUDIES ON INFLAMMATION : XII. MECHANISM OF INCREASED CAPILLARY PERMEABILITY. A CRITIQUE OF THE HISTAMINE HYPOTHESIS. AB - Various types of inflammatory exudates have been obtained either by the introduction into normal tissues of a chemical irritant, or by a burn, or by bacteria in either dogs or rabbits. A study has also been made on an exudate of human origin. These exudates have all been found to contain a factor which induces prompt increase in the permeability of normal skin capillaries, demonstrable by the almost immediate accumulation from the circulation of trypan blue into areas of skin injected with the cell-free exudate. The active factor may be carried down with the precipitate resulting from the interaction of the exudate with either saturated ammonium sulfate or 20 per cent sodium sulfate. The active factor passes through a dialyzing membrane. It can be recovered from the dialysate as a protein-free crystalline material. The active factor manifests no property in common with histamine or presumably with the hypothetical H substance assumed to be closed related to histamine. This is indicated by the following considerations: (a) difference between the tissue staining pattern of the exudate or of its active fraction and that of histamine; (b) opposite effects by histamine and the active factor found in exudates on the tonicity of the isolated strip of guinea pig intestine. The observations presented in this report do not substantiate Lewis' hypothesis of histamine or of its closely related H substance as the primary cause of increased capillary permeability in inflammation. The present studies are being continued in an endeavor to free of its impurities and to identify the active crystalline-like material isolated from an inflammatory exudate. The details of this investigation will form the subject of a separate future communication. PMID- 19870550 TI - A HIGH SPEED VACUUM CENTRIFUGE SUITABLE FOR THE STUDY OF FILTERABLE VIRUSES. AB - 1. A high speed centrifuge is described in which the speed is limited only by the strength of the material of which the rotor is made. It carries sixteen tubes, each of which conveniently accommodates 7 cc. of fluid. 2. The centrifuge operates in a very high vacuum and therefore requires only a small amount of driving energy. The arrangement has been found to eliminate the possibility of producing injurious frictional heat. 3. The rotating parts are supported by anair bearing and are driven by compressed air. 4. The centrifuge has been successfully operated at a speed of 30,000 revolutions per minute, representing a maximum centrifugal force in the fluid of 95,000 times gravity. 5 Celluloid tubes used for centrifugation of fluid at high speeds are described. 6. Experiments are described in which good sedimentation of the yellow fever virus was obtained. PMID- 19870551 TI - PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES: EFFECT OF BACTERIAL FILTRATES INJECTED INTRAVASCULARLY UPON REACTIONS TO ANTIGEN + ANTIBODY COMPLEXES. AB - Rabbits were sensitized by a single intravenous injection of horse serum 6 days prior to the experiments. In these rabbits there appeared hemorrhagic and necrotic reactions in sites of intradermal tests with horse serum when the tests were preceded by 1 hour, or followed 18 to 24 hours later by an intravenous injection of potent bacterial filtrates. The skin-preparatory and reacting potencies of the filtrates were titrated by means of the phenomenon of local skin reactivity to bacterial filtrate. The experiments demonstrated that the ability of bacterial filtrates to elicit reactions in the antigen injected sites in sensitized animals is strictly conditioned by their skin-preparatory potency and seems to be quite independent of their provocative potency. Combinations of animal protein antigens with homologous antisera, which are endowed with provocative potency but are totally devoid of skin-preparatory potency, fail to elicit reactions in antigen-injected sites. The various methods of elicitation of the phenomenon of local tissue reactivity are summarized and discussed in the text. PMID- 19870552 TI - A SKIN TEST FOR DETECTING GROUP C HEMOLYTIC STREPTOCOCCAL INFECTION CAUSING EPIZOOTIC LYMPHADENITIS IN GUINEA PIGS : APPLICATIONS IN SELECTING BREEDING STOCK. AB - 1. A skin test with a crude bacterial extract prepared from group C (Lancefield) hemolytic streptococci was used as a means of detecting possible carriers of the streptococcus causing epizootic lymphadenitis in guinea pigs. A positive test similar to a positive tuberculin reaction was considered presumptive evidence of present or recent infection with this streptococcus. 2. 20 positive reactors were found in 330 supposedly normal guinea pigs. 3. 195 negatively reacting animals were used as a breeding stock which yielded 1,296 progeny over a period of 15 months. None of the breeding stock or their progeny showed evidence of spontaneous lymphadenitis. Skin tests of 100 of the progeny were all negative. 4. The use of this skin test as a means of obtaining guinea pig breeding stock free of the streptococcus causing spontaneous lymphadenitis is suggested. PMID- 19870553 TI - THE SPECIFIC POLYSACCHARIDES OF TYPES I, II, AND III PNEUMOCOCCUS : A REVISION OF METHODS AND DATA. AB - 1. The thermolability of the specific polysaccharides of Types I, II, and III pneumococcus has been shown by three independent methods: (a) diminution of the viscosity of solutions on heating; (b) decrease in the amount of antibody precipitated from homologous rabbit antisera; and (c) increased tendency (S III) to pass through a collodion membrane. 2. These effects may be explained most simply as a partial depolymerization under the influence of heat. In air, particularly in the presence of broth, oxidation also appears to be involved. 3. Improved and simpler methods of preparation based on these findings, are given for S I, S II, and S III. The resulting products precipitate more anti-S from homologous rabbit antisera than do the earlier preparations. 4. The methyl glycoside of methyl galacturonate has been isolated from the hydrolytic products of S I, and evidence of the ultimate structural unit obtained. PMID- 19870554 TI - HYPERSENSITIVENESS AND ANTIBODY FORMATION IN TUBERCULOUS RABBITS. AB - 1. Rabbits infected with bovine tubercle bacilli develop hyper-sensitiveness to an intracutaneous injection of tuberculin. This sensitiveness appears from the 2nd to the 6th week after infection and increases rapidly thereafter. Tests, as a rule, show fluctuation in the intensity of the sensitization. Sensitization is followed by an interval of several weeks preceding death during which the animals fail to react. 2. Rabbits infected with bovine tubercle bacilli form antibodies that fix complement in the presence of tubercle bacilli. The antibodies appear after 2 weeks, increase during 6 to 10 weeks, and persist until the animals die. 3. In the later period of infection the skin fails to react to tuberculin at a time when the serum contains complement fixing antibodies. PMID- 19870555 TI - LIPIDS AND IMMUNOLOGICAL REACTIONS : III. LIPID CONTENT OF SPECIFIC PRECIPITATES FROM TYPE I ANTIPNEUMOCOCCUS SERA. AB - 1. Specific precipitates resulting from the interaction of the homologous capsular polysaccharide and Type I antipneumococcus horse and rabbit sera have been analyzed by gasometric micro methods for total nitrogen, lipid nitrogen, and lipid carbon. 2. Lipid may, under certain conditions, form as much as 51 per cent or as little as 4 per cent by weight of specific precipitates. 3. The total lipid content of specific precipitates, within the range studied, is entirely independent of the protein content. 4. Lipid nitrogen forms a very small but detectable portion of the total nitrogen of precipitates. 5. The absolute lipid content of precipitates is a function of the concentration of lipid in the reacting mixture prior to precipitation, and seems to be governed by the laws of adsorption phenomena. PMID- 19870556 TI - SPOTTED FEVER : II. AN EXPERIMENTAL STUDY OF FIEVRE BOUTONNEUSE. AB - Several methods for the experimental study of the rickettsial diseases have been applied to fievre boutonneuse. An analysis of the results has indicated that fievre boutonneuse is a variety of spotted fever and that the etiologic agent is a rickettsia which belongs to the genus Dermacentroxenus and to the species rickettsi (Wolbach (6)). The distinctive morphology of the organism and its characteristic intranuclear clustering in ticks and in tissue cultures are the important criteria upon which this conclusion is based. Immunological, histological, and cytological observations of a confirmatory nature are also reported. PMID- 19870557 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS. II. AB - In continuation of previous work sensitization experiments have been made with various substances such as urushiol, benzyl chlorides, and acyl chlorides. In the case of a series of substituted benzenes (Cl, NO(2)) a connection between sensitizing capacity and lability of the Cl or NO(2) groups has been shown, indicating the formation of conjugated antigens in the animal. This led to the study of benzyl and acyl chlorides which, actually, were found to have sensitizing capacity. Most informative as to the relationship between reactions of the skin surface and anaphylaxis were experiments with acyl chlorides. Guinea pigs sensitized with p-chlorobenzoyl chloride showed, on the one hand, the usual surface lesions after application of the substance, and on the other typical anaphylactic shock following intravenous injection of a compound of p chlorobenzoyl chloride and guinea pig serum; from which it may be inferred that the two types of allergic manifestation are closely related conditions. PMID- 19870558 TI - THE RELATION BETWEEN ANTIANAPHYLAXIS AND ANTIBODY BALANCE : I. THE ROLE OF EXCESS OF CIRCULATING ANTIBODY IN HYPERSENSITIVENESS. AB - 1. Sensitized guinea pigs injected with normal rabbit or guinea pig serum previous to intravenous inoculation of antigen may be protected against a few lethal doses of antigen. The protection is greater with foreign than with homologous serum and appears to be related roughly to the amount of serum introduced. 2. Sensitized guinea pigs injected with antibody-containing serum preliminary to intravenous injection of antigen, show no greater refractoriness to anaphylaxis than do those injected with normal serum. 3. Moreover, in many instances, the injection of an excess of antibody into the circulation of sensitized guinea pigs, leads to an increased susceptibility of these animals to anaphylaxis. 4. These results indicate that an excess of circulating antibody is not responsible for a state of antianaphylaxis, but on the contrary, may contribute toward the anaphylactic reaction itself. PMID- 19870559 TI - THE RELATION BETWEEN ANTIANAPHYLAXIS AND ANTIBODY BALANCE : II. THE EFFECT OF SPECIFIC DESENSITIZATION UPON RESISTANCE TO INFECTION AND UPON ANTIBODY BALANCE. AB - It has been shown that antianaphylaxis is not caused by a partial saturation of cellular or humoral antibodies by the following facts. 1. Guinea pigs passively sensitized with anti-horse or antipneumococcus serum and specifically desensitized do not manifest as great a reactivity upon resensitization with the same antiserum as upon the original sensitization. 2. Guinea pigs passively sensitized with anti-Friedlander Type B serum or antipneumococcus Type II serum and specifically desensitized do not attain the same degree of reactivity as normal animals when passively sensitized with anti-horse serum. 3. Guinea pigs passively sensitized with anti-Friedlander Type B serum and desensitized with the specific carbohydrate remain as resistant to infection with Friedlander's bacillus Type B as undesensitized guinea pigs. Since in this case, at least, it is agreed that type-specific immunity and type-specific hypersensitiveness are due to the same type-specific antibody, a change in anaphylactic response should be accompanied by a change in immune response, provided this change depends on antibody balance. 4. A determination of the antibody content of the serum of sensitized as well as of desensitized guinea pigs by mouse protection tests indicates that a loss of reactivity in desensitized animals cannot be adequately accounted for on the basis of depletion of circulating antibody. These experiments suggest that hypersensitiveness and resistance are different manifestations of the same antigen-antibody reaction while antianaphylaxis is a state of refractoriness which is due neither to excess of circulating antibody nor to antibody depletion, but is the result of secondary changes the true nature of which is still not definitely established. PMID- 19870560 TI - FURTHER STUDIES ON TYPHUS FEVER : ON HOMOLOGOUS ACTIVE IMMUNIZATION AGAINST THE EUROPEAN STRAIN OF TYPHUS FEVER. AB - 1. Guinea pigs can be actively immunized against European typhus fever with homologous formalinized Rickettsia tissue cultures, provided sufficient amounts are injected. The method is suggested for practical application in man. 2. Serovaccination against European typhus fever can be successfully applied to guinea pigs by a variety of methods, the simplest of which consists of the injection of mixtures of virulent defibrinated guinea pig blood and convalescent guinea pig serum taken from 3 to 5 days after defervescence. Similar results can be obtained with mixtures in which tissue culture virus, either with convalescent guinea pig serum or with antimurine horse serum, is used. There is no indication so far that such animals become carriers. Possible application of these methods to typhus epidemics is discussed. PMID- 19870561 TI - STUDIES ON THE MECHANISM OF IMMUNITY IN TYPHUS FEVER : I. RICKETTSIA PROWAZEKI IN THE DIFFERENT STAGES OF THE TYPHUS LESION. AB - This study of the lesions produced in the skin of guinea pigs inoculated intracutaneously with Mexican typhus virus, shows that there is an early polymorphonuclear response at the point of inoculation. As early as 24 hours after the virus is given, a mononuclear phagocytic infiltration, which is more pronounced around the larger vessels of the corium, vascularis, and muscularis, replaces the polymorphonuclear infiltration. The endothelial cells of capillaries and small vessels swell up, thus partially occluding the lumina. Rickettsia bodies are found in the swollen cells, in numbers which remind one of the intracellular Rickettsiae of the tunica in typhus infected guinea pigs. The mature Mooser's cells are found in abundance on the 3rd to the 4th day after inoculation. They are found in various positions as follows: (a) in the endothelial cells of capillaries, particularly in places of little or no infiltration; (b) within the mononuclear nodules formed around the larger vessels and within the dense infiltration of the vascularis (the parasitized cells are usually traced to a capillary wall); and (c) less frequently the organisms are found within the swollen cells of arterioles and small veins. The organisms disappear gradually from the zones of increasing polymorphonuclear infiltrations, suggesting that the presence of such polymorphonuclears is due to the bursting of the infected cells. In the artificial lesions produced in the skin by the inoculation of considerable numbers of Rickettsiae, the tissue reactions are abnormally enhanced. One can see in the same slide different stages of the development of the lesions and their relationship to the infecting agent. The early perivascular infiltration by mononuclear phagocytes does not seem to be related to an actual infection of the endothelial lining by the inoculated virus, but seems rather, when properly controlled, to be primarily due to a nonspecific type of response. The capillaries or small vessels within these infiltrated zones may become parasitized and call forth a polymorphonuclear reaction which may thus transform the cytological picture of the nodule. The subsequent migration of macrophages terminates the histological sequence. In capillaries apart from areas of cellular infiltrations, the polymorphonuclear reaction is first to appear, when the Rickettsiae are liberated from the cells. One cannot safely generalize from the results observed in an artificial typhus lesion, but in the light of these observations, it is probable that the Rickettsia bodies are difficult to find in typhus patients or infected animals because they disappear rapidly from the nodules, or perhaps because some nodules are not necessarily related to an infected endothelium. At any rate, a late typhus lesion is not likely to reveal Rickettsiae which most probably have been removed by the early polymorphonuclear invasion. PMID- 19870562 TI - STUDIES ON THE MECHANISM OF IMMUNITY IN TYPHUS FEVER : II. ALLERGIC AND TOXIC REACTIONS PRODUCED WITH RICKETTSIA PROWAZEKI. AB - The intradermal inoculation of Mexican typhus virus into immune guinea pigs produces a local reaction which is similar in its appearance to the lesion observed in the skin of normal animals submitted to the same treatment. The reaction in the immune animal appears earlier and fades sooner than the lesion in the normal guinea pig. The inoculation of heat-killed or formalin-killed Rickettsiae produces no significant reactions at the site of the intradermal injection in typhus immune guinea pigs. The virus, inoculated intradermally, has been recovered from the local lesion 72 hours after the injection into typhus immune guinea pigs. Normal guinea pigs and persons without a history of typhus fever present a congestion and some swelling of the skin at the site of the intradermal injection of formalinized Mexican Rickettsiae. The reaction appears 24 hours after the inoculation and fades within 48 hours. Heating the formalinized Rickettsia suspensions at 70 degrees C. for 30 minutes renders them inactive in normal men and guinea pigs. From the experiments reported in this paper it seems that the reactions observed in typhus immune guinea pigs submitted to a second inoculation of typhus virus, belong to the group of reactions presented by tuberculous animals (Koch's phenomenon) and the accelerated takes shown by immune persons submitted to revaccination with vaccinia virus. A heat labile substance has been demonstrated in the formalinized Rickettsia bodies, which produces a reaction in the skin of normal men and guinea pigs. PMID- 19870563 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : III. ANAPHYLAXIS INDUCED BY ARSPHENAMINE. AB - Experiments are described which show that with a given treatment guinea pigs can be sensitized to arsphenamine, so that a considerable percentage die in anaphylactic shock on intravenous administration of the substance. PMID- 19870564 TI - AN ACQUIRED RESISTANCE OF GROWING ANIMALS TO CERTAIN NEUROTROPIC VIRUSES IN THE ABSENCE OF HUMORAL ANTIBODIES OR PREVIOUS EXPOSURE TO INFECTION. AB - 1. As mice grow older they acquire a resistance to peripheral inoculation with the Indiana and New Jersey strains of vesicular stomatitis virus and to some extent also to Western equine encephalomyelitis virus, but little or none to the Eastern strain. 2. While some mice may become resistant as early as the 30th day of life, others may still be susceptible at 1 year of age. 3. This resistance is readily demonstrable when the inoculations are made by intranasal, subcutaneous, intramuscular, intraperitoneal, and intravenous routes, but not when the virus is injected directly into the brain. 4. The resistance is not related to previous exposure to infection or to the presence of specific or nonspecific antiviral bodies in the blood. 5. No difference in susceptibility to peripheral inoculation was found in young and old guinea pigs to pseudorabies virus, and in relatively young and old Macacus rhesus monkeys to poliomyelitis virus. PMID- 19870565 TI - HUMORAL ANTIBODIES AND RESISTANCE OF VACCINATED AND CONVALESCENT MONKEYS TO POLIOMYELITIS VIRUS. AB - 1. Monkeys convalescent from a paralytic attack of poliomyelitis develop humoral antibodies slowly; in the present series their first appearance in most was at 2 months and in some not until 3 months after the attack. 2. Convalescent monkeys display resistance to reinfection with the same strain by the nasal route long before antibodies become demonstrable in their serum, in this respect differing from many vaccinated monkeys whose serum neutralizes the virus, while they remain susceptible to nasal infection. 3. When antibodies appear in the serum of resistant convalescent monkeys, they are not quantitatively greater than in the serum of vaccinated monkeys which succumb to infection. As regards resistance to infection, humoral antibodies, therefore, do not have the same significance in vaccinated as in convalescent poliomyelitis monkeys. PMID- 19870566 TI - STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : VII. CULTIVATION OF THE COCCOBACILLIFORM BODIES IN FERTILE EGGS AND IN TISSUE CULTURES. AB - The coccobacilliform bodies of fowl coryza were successfully cultivated in the fetal membranes of fertile eggs. Microscopic examination indicated growth in approximately 50 per cent of 94 eggs inoculated on the 3rd to 4th day of incubation. Growth was generally inhibited, however, in eggs inoculated on the 10th day. One strain of the specific bodies was maintained through 11 successive passages in 4 day eggs. A more consistent growth of the coccobacilliform bodies was obtained in tissue cultures. One strain, originally isolated in November, 1935, has been carried through 100 successive subcultures at intervals of 1-3 days. The specific bodies fail to maintain their morphological identity for any length of time in this medium. It is noted that growth of the coccobacilliform bodies in fertile eggs and in tissue cultures is not dependent on the presence of living cells. PMID- 19870567 TI - STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : VIII. THE INFECTIVITY OF FETAL MEMBRANE AND TISSUE CULTURE SUSPENSIONS OF THE COCCOBACILLIFORM BODIES. AB - Fetal membrane and tissue culture suspensions of the coccobacilliform bodies are infective for normal fowl. Intranasal injection is commonly followed by a coryza which is serially transmissible and communicable by direct contact. The specific bodies are generally demonstrable in the nasal exudate of birds infected either by injection or contact. Compared with the original strain of the coryza of slow onset the reaction produced by these suspensions is often less vigorous; the incidence of apparent cases, characterized by a nasal discharge, being 97 per cent and 53 per cent, respectively. The apparent cases are similarly characterized by a long incubation period and a tendency towards chronicity. PMID- 19870568 TI - THE STANDARDIZATION OF LONGEVITY AGAINST DOSE IN EXPERIMENTAL TUBERCULOSIS BY INTRACEREBRAL INOCULATION. AB - Intracerebral inoculation of tuberde bacilli into normal guinea pigs induces acute meningoencephalitis with minor metastatic lesions. The disease is fatal in a relatively short time and is characterized by a rather typical succession of symptoms and a fairly characteristic temperature curve. The disease is produced by very small numbers of bacilli; and under standard conditions, survival time is so uniform as to make possible quantitative or titration experiments. Certain possible applications of the method are discussed. PMID- 19870569 TI - THE SUSCEPTIBILITY OF SWINE TO THE VIRUS OF HUMAN INFLUENZA. AB - Swine inoculated intranasally with human influenza virus alone develop an ill defined, mild, and usually afebrile illness of short duration. At postmortem the anterior lobes of the lungs of such animals contain scant, scattered areas of lobular atelectasis. Transmission of the virus for 5 serial passages through two groups of swine failed noticeably to enhance its pathogenicity for this species. The disease produced in swine by infection with human influenza virus alone is indistinguishable clinically and pathologically from that caused by infection with swine influenza virus alone. Transmission of human influenza virus from swine to swine by contact succeeded in only one of four attempts. Swine inoculated intranasally with a mixture of human influenza virus and H. influenzae suis usually develop a febrile, depressing illness similar to mild swine influenza. The pneumonia encountered in such animals at autopsy is similar to but less extensive than that seen in swine influenza. In some animals H. influenzae suis fails to become established and the disease then seen is identical with that caused by human influenza virus alone. The human influenza virus recovered after 5 serial transfers in swine was immunologically the same as that with which the experiments were begun. PMID- 19870570 TI - STUDIES ON THE SOLUBLE PRECIPITABLE SUBSTANCES OF VACCINIA : I. THE DISSOCIATION IN VITRO OF SOLUBLE PRECIPITABLE SUBSTANCES FROM ELEMENTARY BODIES OF VACCINIA. AB - 1. Thermolabile and thermostable soluble precipitable substances dissociate in vitro from the elementary bodies of vaccinia. 2. These substances are serologically related to the soluble precipitable substances found in suspensions of fresh vaccine pulp. PMID- 19870571 TI - STUDIES ON THE SOLUBLE PRECIPITABLE SUBSTANCES OF VACCINIA : II. THE SOLUBLE PRECIPITABLE SUBSTANCES OF DERMAL VACCINE. AB - 1. Thermolabile (L) and thermostable (S) antigens occur in solution in suspensions of vaccine pulp. 2. These antigens are also present on the elementary bodies of vaccinia and participate in the agglutination of these bodies by antivaccinia serum. PMID- 19870572 TI - STUDIES ON THE SOLUBLE PRECIPITABLE SUBSTANCES OF VACCINIA : III. THE PRECIPITIN RESPONSES OF RABBITS TO THE LS ANTIGEN OF VACCINIA. AB - Observations on antibody production in the rabbit in response to the injection of the LS antigen of vaccinia have shown that this antigen retains its ability to stimulate the production of L and S antibodies, not only when it is in a state of solution as found in lapine Seitz filtrates, but also after it has been partially purified. As reported in previous papers, both the L and S antibodies participate (a) in the true agglutination of washed elementary bodies, (b) in the precipitation of the soluble LS antigen found in fresh vaccine suspensions or dissociated in vitro from washed elementary bodies. The difference in the thermostability of the L and S components of the LS antigen as far as their reactivity in vitro is concerned, holds in respect of their capacity to stimulate antibody production. Heating at 70 degrees C. invariably abolishes the antigenicity of the L component while the S component remains antigenic after being heated to 90 degrees C. PMID- 19870573 TI - IMMUNOLOGICAL STUDIES ON A NEW PREPARATION OF TYPE SPECIFIC POLYSACCHARIDE FROM PNEUMOCOCCUS TYPE I. AB - A type specific polysaccharide has been isolated from the autolyzed broth of Type I Pneumococcus by a modified Avery and Goebel's method. The newly prepared polysaccharide reacts with the homologous immune rabbit serum which has been completely absorbed with the acetyl polysaccharide of Avery and Goebel. The newly prepared polysaccharide produces passive immunity in mice and rats and possibly in rabbits. The antigenicity is not lost on boiling in acid or alkaline medium, but the precipitative activity is decreased. In conclusion, it has been shown that the polysaccharide from Type I Pneumococcus, as isolated by a slight modification of Avery and Goebel's method, is a more complete antigen. PMID- 19870574 TI - LIPIDS AND IMMUNOLOGICAL REACTIONS : IV. THE LIPID PATTERNS OF SPECIFIC PRECIPITATES FROM TYPE I ANTIPNEUMOCOCCUS SERA. AB - 1. Complete lipid patterns of specific precipitates from horse and rabbit Type I antipneumococcus sera, as well as of the sera themselves, have been determined by gasometric micro methods. 2. The lipid patterns of horse and rabbit antisera are very similar, and as regards the phosphatide fractions are relatively identical. 3. The lipid patterns of specific precipitates from horse and rabbit antisera show one outstanding qualitative difference. The specific precipitate from horse antiserum contains an amino phosphatide, which is probably cephalin, while that from rabbit antiserum contains a non-amino phosphatide, which is thought to be lecithin. PMID- 19870575 TI - A QUANTITATIVE TECHNIQUE FOR PERFORMING PLASMAPHERESIS. AB - 1. A special apparatus and technique are described which permit one to conduct plasmapheresis quantitatively. 2. The validity of the methods employed, for determining serum protein concentration and blood volume as prerequisites for the calculation of the amount of blood to be withdrawn, are discussed. PMID- 19870576 TI - THE INFLUENCE OF DIET UPON THE REGENERATION OF SERUM PROTEIN : I. STANDARDIZATION OF EXPERIMENTAL TECHNIQUE. AB - 1. From a consideration of previous work related to the problem of the influence of diet upon the regeneration of serum protein, a plan of study is described which eliminates the many variables shown to be operating in the studies conducted by these pioneer workers. 2. By the administration of a protein-free diet at a high level of caloric intake to the dog subjected to plasmapheresis during which one-fourth of the blood volume of the animal is withdrawn daily, it is possible to reduce the serum protein concentration to the basal level (3.5 to 4.2 per cent) and to deplete the organism of its reserve stores of this protein within 1 week. The subsequent week has been demonstrated to be an equilibrium period. 3. The dog contains a reserve store of serum protein building material equivalent to about 30 to 40 per cent of the total amount normally present in the circulation. 4. When fed the protein-free diet and when subjected to quantitative plasmapheresis, whereby the basal level of the serum protein concentration is maintained constant, the dog is able in 1 week to regenerate approximately 20 to 30 per cent of the total amount of this blood protein normally present in the plasma. 5. The administration of a diet favorable for promoting the regeneration of serum protein requires approximately 4 to 5 days before a constant and maximal response to the dietary stimulus is obtained. Equilibrium data are yielded during the 2nd week, and these are employed in calculating the potency ratio of the dietary protein. PMID- 19870577 TI - THE INFLUENCE OF DIET UPON THE REGENERATION OF SERUM PROTEIN : II. THE POTENCY RATIOS OF SERUM PROTEIN, LACTALBUMIN AND CASEIN, AND THE EFFECT OF TISSUE PROTEIN CATABOLISM ON THE FORMATION OF SERUM PROTEIN. AB - 1. By the technique of quantitative plasmapheresis the effects of single proteins in artificial synthetic diets were studied with respect to their value in promoting the regeneration of serum protein. 2. The ratio of (a) the amount of serum protein per week removed by bleeding above that regenerated by the dog when eating the protein-free diet, to (b) the dietary protein increment (i.e., above that required for nitrogen equilibrium) was termed the potency ratio. The results indicated that serum protein was slightly superior to casein and lactalbumin in promoting the regeneration of serum protein. However, the respective potency ratios, varying from approximately 0.51 to 0.36, were comparable and not widely divergent as those reported by others. It was concluded that, whereas in some individuals dietary proteins may be able to produce a significant increase in the serum protein concentration, the potency ratios are not sufficiently different to warrant the administration of any one protein in preference to another. 3. The inhibitory effect of the basal protein-free diet with respect to serum protein regeneration in the dog was also demonstrated by the inability of the protein concentration to attain the normal level in spite of discontinued plasmapheresis. However, a subsequent fasting period resulted in a progressive rise in the serum protein concentration until the normal value was approximated. These observations are interpreted as indicating that the products of tissue protein catabolism can be utilized in the formation of new serum protein. 4. The experimental production of what seems to be an inhibition of the serum protein regenerating mechanism was described. This observation together with the hypothetical evidence presented by Bloomfield (17) and Weech and his associates (9) suggests that the most profitable line of approach to solution of the problem of hypoproteinemia lies not so much in the evaluation of dietary factors but in finding a way for stimulating internally the serum protein regenerating mechanism, which seems to involve in some manner the capacity of the tissue to furnish protein for the needs of the plasma. 5. A hypothesis explaining the mechanisms responsible for serum protein formation was presented and the experimental support for it discussed. The role of tissue protein catabolism in this function was emphasized. PMID- 19870578 TI - EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTI-KIDNEY SERUM : I. PREPARATION AND IMMUNOLOGICAL STUDIES OF NEPHROTOXIN. AB - Nephritis can be induced in rats by the injection of anti-kidney sera obtained from rabbits immunized with suspensions of perfused rat kidney. Anti-kidney sera, thus prepared, contain a number of antibodies capable, on injection into rats, of inducing a severe anaphylactoid reaction with general vascular manifestations that involve the kidney as well as other organs. These sera also contain a nephrotoxic agent that affects the kidney primarily. The nephrotoxic effect is characterized clinically by severe persistent albuminuria with casts, and transient anasarca during the acute disease, but no significant hematuria occurs. When a severe anaphylactoid reaction is superimposed on the nephrotoxic injury, hematuria is an outstanding feature. Nephrotoxin is demonstrable in vivo and is not related quantitatively to the precipitins in the anti-kidney serum against kidney extract. It is most readily obtained by immunization with kidney suspensions, but may occasionally appear after injections of other organ preparations; it does not result from immunization with erythrocytes or serum. Nephrotoxin is present in the globulin fraction of anti-kidney serum. The nephrotoxic action of anti-kidney serum is easily removed by absorption with kidney cells or fat-free kidney tissue. Similar preparations of liver likewise remove it, but less readily. Neither kidney, liver, or brain lipids affect it, nor does absorption with red blood cells or serum. Nephrotoxin appears to be an antibody that is relatively organ specific in its affinities. It differs from the more common antibodies involved in reverse anaphylaxis in one respect, at least: The animal rapidly becomes desensitized against the latter and fails to react, whereas desensitization to nephrotoxin is difficult to secure. PMID- 19870579 TI - TISSUE CULTURE STUDIES ON BACTERIAL HYPERSENSITIVITY : III. THE PERSISTENCE IN VITRO OF THE INHERENT SENSITIVITY TO TUBERCULIN OF CELLS FROM TUBERCULOUS ANIMALS. AB - 1. Mononuclear exudative cells, obtained from tuberculous guinea pigs by the intrapleural injection of parowax, exhibited characteristic sensitivity to the toxic action of tuberculin when tested in tissue culture. 2. Experiments with these cells, practically free of body fluids, show conclusively that sensitivity to tuberculin is an inherent characteristic of mesenchymal cells from tuberculous animals. 3. Fibroblastic growths which developed from mononuclear exudative cells derived from a tuberculous animal showed persistence of sensitivity to the toxic action of tuberculin on repeated transplantations over a prolonged period in vitro. PMID- 19870580 TI - EFFECT OF PNEUMOCOCCUS AUTOLYSATE ANTITOXIN ON PNEUMOCOCCUS PNEUMONIA IN GUINEA PIGS. AB - 1. In rabbits, guinea pigs, and mice pneumococcus autolysate antitoxin has no effect against generalized infection by the pneumococcus. 2. In a large proportion of cases of pneumonia and sepsis caused by the intratracheal inoculation of large amounts of living pneumococci in normal or sensitized guinea pigs, autolysate antitoxin saves the animal. 3. The autolysate antitoxin is protective in most cases of pneumonia and sepsis caused by the intratracheal inoculation of small amounts of living pneumococci combined with sublethal doses of staphylococcus toxin. 4. These experiments indicate that in pneumococcus pneumonia of guinea pigs the autolysate toxin or toxins are elaborated only in the lungs. PMID- 19870581 TI - THE EFFECT OF EXPERIMENTAL REDUCTION OF KIDNEY SUBSTANCE UPON THE PARATHYROID GLANDS AND SKELETAL TISSUE. AB - Reduction of renal tissue in young rats regularly leads to a marked increase in the volume of the parathyroid glands. If partially nephrectomized rats are maintained on a low calcium diet, growth is stunted, and skeletal lesions are produced, of far greater severity than can be ascribed to the dietary calcium deficiency alone. The picture closely resembles that found in cases of renal rickets in children. PMID- 19870582 TI - DOES THE GONADOTROPIC HORMONE INDUCE ANTIBODIES OR ANTIHORMONES? AB - 1. It is shown in 52 experiments upon rabbits that the purified gonadotropic hormone has no antigenic function-as an antigen or a haptene-either in the form of prolan derived from the urine of pregnant women or in the form of prosylan, derived from the blood of pregnant mares. 2. The experiments reported elsewhere which ascribe an antigenic structure to prolan, are due to confusion with the so called non-specific urine antigen (urine colloid). 3. Sera of rabbits which are abundant in prolan antihormone (Collip) also contain no antibodies against prolan. The antihormones against the gonadotropic substances must accordingly be considered as protective ferments (Abderhalden). 4. The employment of castrated animals has no influence upon the above results. 5. The lack of immunizingly effective components in pure prolan and prosylan (a) inhibits the possibility of serological diagnosis of pregnancy for the diagnostician; (b) protects the therapeutist against undesirable toxic and allergic secondary effects in intensive prolan treatment. The latter also is valid for pure prosylan preparations. 6. No prolan antibodies could be found in the blood of pregnant women in the 2nd and 4th month of pregnancy, or 1 day and 1 month postpartum. 7. Antihormone against prolan of human origin has no paralysing effect upon a prosylan preparation derived from the blood of pregnant mares (antex); there exists therefore a species specificity. PMID- 19870583 TI - IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS : V. METABOLIC STUDIES OF ELEMENTARY BODIES OF VACCINIA. AB - Previous investigations of the metabolism of viruses have been hindered by the difficulty or impossibility of securing adequate amounts of the active agents in a pure state. However, by the application of recently developed technics, it is possible to prepare large quantities of vaccine virus free from living host cells, and to concentrate the suspensions to any desired degree. Advantage has been taken of this in the present investigation. Large quantities of washed elementary bodies of vaccinia were prepared, and suspended in small volumes of liquid. The amounts of oxygen consumed aerobically and of acid produced anaerobically were measured, the latter as carbon dioxide released from a buffer solution containing sodium bicarbonate and carbon dioxide. Even when large amounts of virus were used (as much as 26 mg., dry weight, of elementary bodies) the quantities of oxygen consumed and of acid liberated were very small. Furthermore, the greater part of the gaseous exchange which occurred took place in the first hour of observation; during the succeeding periods no absorption of oxygen or liberation of carbon dioxide was demonstrated. No increased absorption followed the addition of glucose, glucose monophosphate, or methylene blue. At the conclusion of the experiments the virus was shown to be fully active. Such findings are in sharp contrast to the results to be expected if true respiration were taking place, as for example in resting bacteria, in which case the quantities of oxygen consumed are much greater and are relatively constant during the period of observation. It was considered that the failure of elementary bodies to consume oxygen might be due to lack of a proper substrate, or of respiratory supplements. In an effort to supply these essentials, a tissue extract was prepared which was shown to contain respiratory supplements, and this was added to the suspension of elementary bodies. It had, however, no effect on the rate of utilization of oxygen by the elementary bodies. Since elementary bodies alone, and in the presence of simple and complex substrates, showed no evidence of continued respiration, it was decided to ascertain whether they contained substances capable of stimulating the metabolism of other cells. Rabbit erythrocytes were used for this purpose; and the amounts of oxygen consumed under aerobic conditions and of acid produced under anaerobic conditions, respectively, by the red blood cells were determined. In neither case was any consistent stimulation of metabolism demonstrated. In the interpretation of the results of our experiments it must be borne in mind that the conditions under which they were performed are highly artificial, and while they are compatible with the survival of virus, there is no reason to suppose that they would permit its growth (3, 4). It may be said, however, that under the conditions which have been described above, no evidence was secured that vaccine virus, in considerable amounts, freed from viable host cells and bacteria, is capable of continued utilization of measurable quantities of oxygen, or of continued release of appreciable amounts of acid. PMID- 19870584 TI - THE BACTERICIDAL PROPERTIES OF ULTRAVIOLET IRRADIATED LIPIDS OF THE SKIN. AB - The lipids of the skin after exposure to ultraviolet light are bactericidal. Since other fats and oils which have been irradiated are bactericidal on account of the active oxygen released on contact with bacteria, the mechanism of the bactericidal action of irradiated lipids of the skin must be similar because the lipids have the properties of other irradiated fats and oils. Irradiation increases the active oxygen content of dried skin markedly but little increase occurs if the lipids have been extracted. Although the normal lipids extracted from the skin contain some active oxygen, the active oxygen content is much increased by irradiation. The vapor from lipids exposed to ultraviolet light fogs photographic plates intensely and retards the growth of hemolytic streptococcus. When emulsified in salt solution, the irradiated lipids kill hemolytic streptococcus promptly in comparison with emulsions of lipid which have not been irradiated. The addition of neutralized cysteine HCl to the emulsions of the lipid, normal or irradiated, prolongs the life of bacteria suspended in the emulsions. This protective effect is due to the reducing action of the cysteine, Normal non-irradiated lipid, extracted from the skin under conditions which permit oxidation, kills bacteria more quickly than that used in these experiments, where precautions were taken to prevent oxidation (unpublished data). Even though these precautions were taken some oxidation occurred, because lipid so extracted contained some active oxygen, and bacteria lived longer in emulsions of this normal lipid if cysteine were added. PMID- 19870585 TI - VITAMIN C THERAPY AND PROPHYLAXIS IN EXPERIMENTAL POLIOMYELITIS. AB - 1. A group of 34 monkeys were infected intracerebrally with 0.1 cc. of a 10 per cent virus suspension. Following infection, 9 animals were treated with daily injections of 700 to 100 mg., 16 with 50 to 10 mg. and 9 with 5 mg. of vitamin C for a period of 2 weeks. In the whole group there were 6 animals that survived without showing any evidence of paralysis. 2 of these had received 50 to 10 mg. while 4 had received 5 mg. All of 19 untreated control monkeys, infected simultaneously with the same amount of virus, developed paralysis. 2. Another group of 6 monkeys were infected intracerebrally with 0.05 cc. of virus. Following infection, one animal was treated in the same manner with 25 mg. and 5 with 5 mg. of vitamin C. In the whole group there was one animal that survived without showing any evidence of paralysis. This animal had received 5 mg. All of 7 untreated control monkeys, infected simultaneously with the same amount of virus, developed paralysis. 3. A third group of 22 monkeys were infected intracerebrally with 0.01 cc. of virus. Following infection, one animal was treated in the same manner with 100 mg., 2 with 50 to 10 mg., and 19 with 5 mg. of vitamin C. In the whole group there were 12 animals that survived without showing any evidence of paralysis. One of these had received 10 mg., while 11 had received 5 mg. Of 12 untreated control monkeys, infected simultaneously with the same amount of virus, 2 failed to show any paralytic symptoms and 10 developed paralysis. 4. A summary of the results obtained in all three groups shows: (a) that among a total of 62 treated monkeys, 19 survived without paralysis and 43 succumbed to the disease, while of a total of 38 untreated controls, only 2 failed to develop paralysis and 36 succumbed to the disease; (b) that treatment with large doses of vitamin C was without any beneficial effect (all 10 monkeys which had received 700 to 100 mg. developing paralysis, that the administration of intermediate doses was followed by occasional survival without paralysis of the treated animal (3 monkeys surviving of a total of 19 which had received 50 to 10 mg.), and that nearly one-half of the animals which had received small doses escaped the disease (16 monkeys surviving of a total of 33 which had received 5 mg.). 5. Attempts to protect monkeys against subsequent intracerebral infection by the prophylactic administration of vitamin C, either per os or parenterally, have produced negative results. 6. The pathogenesis of infantile paralysis is discussed in the light of the experimental findings and the possibility is suggested that vitamin C represents one of the deficiency factors in the susceptibility problem of the human disease. PMID- 19870586 TI - THE BACTERICIDAL ACTION OF HUMAN SERUM ON HEMOLYTIC STREPTOCOCCI : I. OBSERVATIONS MADE WITH SERUM FROM PATIENTS WITH ACUTE INFECTIONS AND FROM NORMAL INDIVIDUALS. AB - Sera obtained from patients at the time of acute active infections were found, in every instance, to be bactericidal for hemolytic streptococci. The observations were made with sera from twenty-five patients. The group consisted of cases of pneumococcus, hemolytic streptococcus, staphylococcus, meningococcus, tubercle bacillus, and malarial infections; the etiology of the diseases in other patients was either uncertain or may have been a mixed infection. In sera taken from the same group of patients, soon after recovery or marked improvement had taken place, the streptococcidal property was absent or greatly diminished in potency. By comparative tests made with sera from twenty healthy adults, the streptococcidal action was not demonstrable. Three different strains of Streptococcus hemolyticus of the beta type were employed in the experiments. Differences in susceptibility of the strains to the killing power of the serum were noted. PMID- 19870587 TI - AN ANALYSIS OF MITOSIS IN LIVER RESTORATION. AB - 1. Following partial hepatectomy in the rat, there is a latent period of 1 day during which the rapidly growing organ shows no increase in cell number. Mitosis then begins rapidly, following a brief pre-mitotic period of visible nuclear changes. 2. It can be shown that the increase in cell number during the ensuing 48 hours follows a formula of the type dN/dt = ke(-kt.), beyond this time it is retarded more than this simplified formula would predict. The average mitosis rate at 1, 2, and 3 day intervals after operation follows the same formula; from this the duration of each mitosis is calculated to be about 49 minutes. It is not necessary to assume that amitotic division plays an important part, and no such divisions have been seen by the writers. 3. The percentage of cells in mitosis in a single hypertrophying liver varies widely from hour to hour, so that a single mitosis count tells nothing about the growth rate. The fluctuations occur at different times in different livers. It appears that no great number of mitoses begin or end simultaneously. 4. Mitoses are evenly distributed throughout the liver and throughout each lobule; there is no preponderance near the bile duct cells. 5. The mean initial mitosis rate (at 24 hours after operation) is 2.13 per cent, and it diminishes from then on. This rate is very similar to that in early embryo heart and tissue cultures of mesenchyme. In individual specimens the rate can be over 8 per cent. This rapid rate occurs without signs of cell dedifferentiation. PMID- 19870588 TI - THE BACTERICIDAL ACTION OF HUMAN SERUM ON HEMOLYTIC STREPTOCOCCI : II. FACTORS WHICH INFLUENCE THE PHENOMENON IN VITRO. AB - Although sera derived from patients at the time of acute, active infection were found to be capable of destroying hemolytic streptococci under aerobic conditions, the organisms retained viability when the tests were performed in the environment of anaerobiosis afforded by a vaseline seal or an anaerobic jar. Within the limitations of the experimental procedures which were employed, the aerobic or anaerobic effect was found to be a reversible reaction. Heating sera at 60 degrees C. for 1 hour inactivated the streptococcidal element in most instances, but not in every case; heating at 56 degrees C. for 1 hour impaired the killing power of half of the specimens which were tested. Sera retained the capacity to destroy hemolytic streptococci when kept in the ice box for 3 weeks; a slight diminution in killing power was noted after 4 weeks. By the methods which were employed, the streptococcidal property of sera could not be correlated with either true antibacterial agglutination or with pseudo-agglutination. The significance of the findings as a basis for analyzing the mechanism of the streptococcidal phenomenon is discussed. PMID- 19870589 TI - THE CAPILLARY SUPPLY IN NORMAL AND HYPERTROPHIED HEARTS OF RABBITS. AB - 1. During normal growth of the rabbit heart, muscle fibers enlarge, and the capillaries multiply so that a relatively constant capillary supply per unit of tissue is maintained from the time of birth to maturity. 2. In cardiac hypertrophy the muscle fibers enlarge, but the capillaries do not multiply and, as a result, the capillary supply per unit of tissue is reduced. 3. The decreased concentration of capillaries in the hypertrophied heart would constitute an impediment to the adequate exchange of metabolic substances, but the seriousness of the impediment cannot be estimated without further physiological data. PMID- 19870590 TI - PRODUCTION OF HEMORRHAGIC NECROTIC SKIN LESIONS IN THE RABBIT BY MEANS OF HEMOPHILUS INFLUENZAE AND HEMOPHILUS PERTUSSIS. AB - 1. The intradermal injection of H. influenzae in the abdominal wall of rabbits induces inflammation, frequently combined with a central pustule. The corresponding injection of H. pertussis causes a bluish violet discoloration of the skin area involved which undergoes slight hemorrhagic necrotic changes within a few days. 2. The intravenous injection of living H. influenzae, 24 hours after the intradermal inoculation with living H. influenzae, is able to transform the respective skin areas into severe hemorrhagic necrotic lesions within 3 to 5 hours. 3. Heat-killed H. influenzae, if injected intravenously, may produce hemorrhagic-necrotic lesions in areas previously prepared with living or heat killed H. influenzae. 4. H. pertussis, if injected intravenously, may cause, perhaps to a lesser extent, hemorrhagic necrotic lesions in skin areas 24 hours previously injected with H. influenzae. 5. The normal course of the infection of rabbit skin with H. pertussis is not, or not essentially, influenced by intravenous reinjection of living or killed H. influenzae or H. pertussis. 6. The agar washing filtrate of B. typhosus, if injected intravenously, can produce hemorrhagic necrotic lesions in rabbit skin prepared intracutaneously with living as well as with heat-killed H. influenzae. The intravenous injection of B. typhosus agar washing filtrate has no influence on areas prepared with H. pertussis. 7. Conversely, H. influenzae as well as H. pertussis, if injected intravenously, are able to produce hemorrhagic necrotic lesions in rabbit skin prepared 24 hours previously with B. typhosus agar washing filtrate. 8. The effectiveness of suspensions of H. influenzae apparently is confined to the bacteria themselves rather than to the supernatant fluids. This does not exclude the possibility of producing effective exotoxins under special experimental conditions. PMID- 19870591 TI - STUDIES ON THE SOMATIC C POLYSACCHARIDE OF PNEUMOCOCCUS : I. CUTANEOUS AND SEROLOGICAL REACTIONS IN PNEUMONIA. AB - A study of 46 cases of pneumococcus pneumonia has shown that a characteristic response may be elicited by the intracutaneous injection of 0.1 mg. of the somatic C polysaccharide of pneumococcus. During the acute febrile period in patients who recover, the response consists of a delayed erythema which reaches its maximum intensity in 18 to 24 hours. During convalescence the reaction is not demonstrable. In patients in whom the disease is prolonged by complications the capacity of the skin to react persists. In 7 fatal cases the skin failed to react to C polysaccharide. Parallel studies of the reaction of the patients' serum with C have confirmed and extended the observations of Tillett and Francis on the appearance of the precipitation phenomenon during the acute stages and its disappearance in recovery. That the cutaneous and serological reactions are not specific for pneumococcus infection is shown by the results in 29 control cases. 8 patients with infectious febrile diseases not of pneumococcus origin gave responses similar to those noted in pneumonia. 2 patients with non-infectious fevers and 18 of 19 normal individuals failed to give either skin or serum reactions. These observations emphasize the importance of using separate components of the bacterial cell in the interpretation of cutaneous and serological reactions in pneumonia. The parallelism in results of the skin and serum tests in pneumococcus pneumonia with the somatic carbohydrate C, the significance of the reactions in relation to the clinical course and outcome of the disease, and the frequency of occurrence of both reactions in bacterial infections other than those of pneumococcal origin, are discussed. PMID- 19870592 TI - STUDIES ON THE SOMATIC C POLYSACCHARIDE OF PNEUMOCOCCUS : II. THE PRECIPITATION REACTION IN ANIMALS WITH EXPERIMENTALLY INDUCED PNEUMOCOCCIC INFECTION. AB - The capacity of the serum of rabbits following intradermal pneumococcus infections to precipitate in the presence of pneumococcus C polysaccharide has been studied during the resultant periods of active infection and during recovery. In rabbits infected with Type I, III, or VIII pneumococci, large hemorrhagic lesions are produced which frequently bring about death of the animals after a febrile illness of 3 to 4 days. Repeated precipitation tests with the sera of these animals have been uniformly and consistently negative, not only during the acute illness but in the recovery period as well. On the other hand, the sera of monkeys of the Macacus cynomolgos species actively ill with experimental Type III pneumonia have been shown to react in precipitation tests with the C substance. The serum reaction appears within the first 24 hours after infection, remains positive in high titer for 2 to 3 days during the acute illness, and disappears with the onset of recovery. The precipitation reaction with C also occurs with the sera of monkeys following intradermal and intraperitoneal infection with pneumococci. The results of precipitation tests of the serum of monkeys during experimental pneumonia are similar to those obtained with the sera of patients suffering from pneumococcus lobar pneumonia. From the results of these studies it would appear improbable that the demonstration of the serum precipitation phenomenon with C polysaccharide in monkeys, and possibly also in man, is conditioned by previous exposure to pneumococcus antigen. PMID- 19870593 TI - EXPERIMENTAL ATTEMPTS TO INCREASE THE BLOOD SUPPLY TO THE DOG'S HEART BY MEANS OF CORONARY SINUS OCCLUSION. AB - Sudden occlusion of the left anterior descending branch approximately 2 cm. below the ostium of the left circumflex coronary artery in the dog's heart produces a mortality rate of approximately 50 per cent. In dogs weighing approximately 15 kilos surviving more than 24 hours (average 1 week), an infarction is produced which almost invariably measures 5 x 5 cm. on surface. Following coronary sinus obturation such secondary sudden occlusion of the left anterior descending branch is followed either by no infarction or by a reduction in the size of the infarct. The success of the procedure, quite apart from the mortality rate, depends upon the completeness of the coronary sinus obturation. On the other hand, sudden and complete coronary sinus obturation by itself is associated with a high operative mortality and apparently does not affect the mortality rate following subsequent sudden left anterior descending branch occlusion. Partial persistent obturation of the coronary sinus, however, is in itself associated with a low operative mortality. Furthermore, its experimental production in dogs appears to lower the mortality rate following subsequent sudden occlusion of the left anterior descending branch and to diminish the extent of the infarction. In the introduction to this report it was pointed out that there are three important desiderata to the problem of improving the coronary circulation in the human heart. The findings herein reported fulfill these requisites to an encouraging degree. It has been shown that following the outlined procedures, a functional increase in the blood supply to the heart can be produced in a significant proportion of experimental animals, this varying with the nature of the experimental procedure. The manipulation is simple, can be performed in the dog within approximately 20 minutes, and does not lead to appreciable pericardial adhesions. Increase in the nutrition of the myocardium is noted 1 week after the experimental procedure. Although no experiments employing sudden left anterior descending coronary branch occlusion were carried out sooner than 1 week, there is available anatomic evidence that within possibly 24 hours after coronary sinus occlusion a dilatation of the vascular bed occurs. In subsequent experiments attempts will be made to determine whether this early vascular dilatation is adequate to compensate for subsequent sudden left anterior descending branch occlusion. A discussion is given of the results following various coronary sinus occlusion procedures in which it is indicated that it is desirable to produce a partial or gradual occlusion in order to lower the mortality rate both of the initial procedure as well as of the subsequent sudden arterial occlusion. Experiments thus far reported on cardiopexy operations are lacking in evidence that they are associated with appreciable improvement in the vascular nutrition of the myocardium. PMID- 19870594 TI - THE PRODUCTION OF BLOOD PLATELETS IN THE LUNGS. AB - 1. A new fixing solution is described, which preserves the platelets and prevents contact hemolysis of the erythrocytes, so that counts of both corpuscles may be made in the same preparation. 2. Comparative counts of platelets in arteries and veins show that arterial blood contains a larger number of platelets than venous blood. This difference is accentuated under experimental conditions that cause a reduction in the number of platelets. It is concluded that new platelets are added to the blood in the capillary areas of the lungs, and that there is a corresponding destruction of platelets as the blood passes through the capillary areas of the systemic circulation. 3. Perfusion of the lungs with a platelet preserving solution, compared with that of other organs, gives evidence of the existence of a source of platelet material in the lungs. 4. Histological examination of the lungs with a technique adequate to give a differential staining of platelet material demonstrates the presence of giant cells in the lungs, and supports the view that they are active in the production of platelets. 5. In extrauterine life giant cells are concentrated in the marrow and the lungs, with the maximum of their activity in platelet production in the lungs. PMID- 19870595 TI - THE EFFECTS OF GONADOTROPIC HORMONES IN THE TREATMENT OF EXPERIMENTAL TUBERCULOSIS. AB - Experimental tuberculosis in rabbits and guinea pigs was favorably influenced by the administration of antuitrin-S, pregnant mare serum, and, to a lesser extent, follutein. No retardation of disease was obtained by the use of either anterior pituitary extract or emmenin. The results suggest that the gonadotropic hormone may be a factor in the temporary amelioration of symptoms observed in tuberculous women during pregnancy. PMID- 19870596 TI - IMMUNIZATION OF RABBITS TO INFECTIOUS PAPILLOMATOSIS. AB - Two intraperitoneal injections of either infectious or non-infectious rabbit papilloma suspensions actively immunize rabbits against papillomatosis. The capacity of the non-infectious suspensions to immunize is considered as evidence that they contain papilloma virus even though none can be demonstrated by the usual infection test. PMID- 19870597 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : II. THE EFFECT OF RESECTION OF SPLANCHNIC NERVES ON EXPERIMENTAL RENAL HYPERTENSION. AB - Excision of the thoracic portion of the splanchnic nerves and the lower four dorsal sympathetic ganglia on both sides failed to prevent the development of persistent hypertension which, in dogs, follows the production of renal ischemia by partial clamping of the renal arteries (1). In dogs with this type of experimental renal hypertension existent for varying lengths of time (up to about 4 years), excision of the splanchnic nerves and the lower four dorsal sympathetic ganglia failed to effect any degree of permanent lowering of the blood pressure. For the dog, at least, these results tend to minimize the importance of the splanchnic vasomotor mechanism in the pathogenesis of renal hypertension. This is in agreement with the conclusions of Prinzmetal and Wilson (6) and of Pickering (7) about the part played by the vasomotor system in human hypertension. It is also in agreement with the work of Page (8), and of Collins (9), who showed that in dogs excision of the extrinsic renal nerves alone does not prevent experimental hypertension due to renal ischemia. Although the results of this investigation fail to give experimental support for the operation that is being practised on human beings with hypertension, yet they do not necessarily controvert the reports of beneficial effects in some cases of human hypertension. Further study of the effects on man is necessary before the results of this operation can be adequately evaluated. PMID- 19870598 TI - IMMUNOLOGICAL AND CHEMICAL INVESTIGATIONS OF VACCINE VIRUS : VI. ISOLATION OF A HEAT-STABLE, SEROLOGICALLY ACTIVE SUBSTANCE FROM TISSUES INFECTED WITH VACCINE VIRUS. AB - A method has been described by which a stable, serologically active substance has been isolated in a relatively pure state from tissues infected with vaccine virus. It has the characteristics of an alcohol-soluble protein which is not precipitated by boiling in a neutral aqueous solution. In a dilution of 1:640,000 it gives a precipitate when mixed with a serum containing antibodies against Craigie's S antigen of vaccine virus, but no visible reaction occurs when it is mixed with serum depleted of S antibodies by means of absorption. PMID- 19870599 TI - THE ANTIBODY RESPONSE OF HUMAN SUBJECTS VACCINATED WITH THE VIRUS OF HUMAN INFLUENZA. AB - Human influenza virus cultivated in tissue culture medium may be administered subcutaneously or intradermally to human individuals without causing evidence of infection. Subjects so treated develop a good titer of circulating antibodies effective against mouse passage virus and, if antibodies were previously present, vaccination stimulates the production of more antibody. The antibodies so induced persist for at least 5 months, although in this period of time some decline in titer may have begun. The antibody response to vaccination parallels both in extent and persistence that occurring as a result of the naturally acquired disease. The available data do not enable one to evaluate the effect of vaccination in preventing human infection with influenza. It seems not unlikely that the increase in circulating antibody will be accompanied by an increased ability to combat the natural infection. PMID- 19870600 TI - INHERITANCE OF RESISTANCE OF MICE TO ENTERIC BACTERIAL AND NEUROTROPIC VIRUS INFECTIONS. AB - Under the conditions specified, there may be selected promptly from a hybrid stock of mice, of which 40 to 50 per cent die following a standard dose of B. enteritidis or St. Louis encephalitis virus, lines in which as high as 95 per cent and as low as 15 per cent succumb. Three lines,-one bacteria-susceptible virus-susceptible, one bacteria-susceptible-virus-resistant, and one bacteria resistant-virus-susceptible,-are regarded as remaining relatively stable after approximately twelve generations of selection and brother to sister or line inbreeding. Crossing susceptible with resistant lines and testing F(1), F(2), F(3), and backcross progeny resulted in mortality percentages in the neighborhood of those expected on the basis that resistance to B. enteritidis and to encephalitis virus is each inherited independently on a single factor basis with resistance dominant over susceptibility. A bacteria-resistant-virus-resistant line is being developed from a cross between bacteria-susceptible-virus-resistant and bacteria-resistant-virus-susceptible lines. All selected lines proved uniformly susceptible to a strain of mouse passage rabies virus. PMID- 19870601 TI - EXPERIMENTAL PRODUCTION OF HEMORRHAGE AND VASCULAR LESIONS IN LYMPH NODES: AN EXTENSION OF THE SHWARTZMAN PHENOMENON. AB - Characteristic changes are produced in the lymph nodes of rabbits following the intravenous injection of certain bacterial filtrates administered 24 hours after either an intralymphatic or an intradermal injection of the same filtrate. These changes are limited to the nodes served by the lymphatic injected or to those furnishing the lymphatic drainage for the injected skin site. By either method the initial or preparatory injection of filtrate reaches the lymph nodes through one or more of its afferent lymphatics, and similar lesions are produced in the nodes. The lesions consist of hemorrhages recognizable by gross and microscopic examination. The capillaries and veins are congested and thrombosed. Their endothelial cells are swollen. Arterioles are generally little affected. Though hemorrhages and thromboses are usually seen together in the nodes, they have been observed occurring independently. They are both probably secondary to endothelial changes. The lesions are not dependent on the amount of preexisting inflammation in the nodes. Endothelial changes, hemorrhages and thromboses were usually noted in the regional nodes when positive Shwartzman reactions had been elicited in prepared skin by intravenous injection of the bacterial filtrate. However, these lesions in many instances were observed under similar conditions in these nodes even when the Shwartzman reaction in the skin was negative. It appears that lymph nodes are more susceptible to the production of the Shwartzman phenomenon than the skin sites which they drain. A single intralymphatic or intradermal injection of the bacterial filtrates used in this study, even in high concentrations, does not produce in adjacent lymph nodes the characteristic changes noted when this preparatory injection is followed by a subsequent intravenous injection of the filtrate. Single intravenous injections also are not productive of hemorrhage and thrombosis in lymph nodes. PMID- 19870602 TI - THE RAPID INVASION OF THE BODY THROUGH THE OLFACTORY MUCOSA. AB - 1. Prussian blue particles pass rapidly from the surface of the olfactory mucosa and within 2 minutes are found in the tissue spaces, in blood and lymph vessels, in the perineural spaces of the olfactory nerve fibers and in the subarachnoid space and pia-arachnoid membrane. 2. There is great affinity of pigment particles for the olfactory sensory cells. 3. Preliminary treatment of the olfactory mucosa with tannic acid does not alter the speed with which this absorption occurs. It does, however, cause an inflammation of the mucosa and appears to prevent the pigment from entering the olfactory sensory cells. 4. Both pneumococci and S. enteritidis pass through the olfactory mucosa and reach the tissue spaces, the vessels and the subarachnoid space with the same rapidity as the pigment. This can be demonstrated both microscopically and by distribution tests. They invade by passage between the cells of the mucosa and there is no apparent affinity of the organisms for the olfactory sensory cells. 5. Tannic acid treatment of the olfactory mucosa in no way alters this invasion of organisms through the mucosa. 6. The pantropic virus, equine encephalomyelitis, was detected in the forebrain as promptly as were pigment and bacteria; neurotropic viruses, however,-those of St. Louis encephalitis, rabies and louping ill,-were not demonstrated in less than 24 hours. PMID- 19870603 TI - STUDIES ON MENINGOCOCCUS INFECTION : X. A FURTHER NOTE ON THE PRESENCE OF MENINGOCOCCUS PRECIPITINOGENS IN THE CEREBROSPINAL FLUID. AB - Precipitin tests have been carried out on spinal fluid from cases of meningococcal and other forms of meningitis, with monovalent anti-meningococcus horse serum of high titer. Using such a test it has been possible within 2 hours to diagnose and type cases of Type I and Type II meningococcal meningitis. In a certain number of cases fluids which were negative when first drawn became positive after standing for 1 or 2 days at 37 degrees C. or room temperature. In 9.5 per cent of all Type I cases the fluids did not become positive. Fluids from cases due to atypical meningococci may react with the type serum of the group to which they belong (i.e., Types II* and VII, which belong to group II, with Type II serum) but do not in every case. Fluids from forms of meningitis other than meningococcal give no reaction. The use of concentrated sera is not advantageous at present, owing to the heterologous reactions which occur. PMID- 19870604 TI - CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES : I. PURIFICATION BY DIALYSIS, AND ATTEMPTS AT FRACTIONAL PRECIPITATION. AB - A quantitative biological assay of the products obtained from the dialysis of B. typhosus, meningococcus, and B. coli culture filtrates has been undertaken. It was found that the active principles of the phenomenon of local skin reactivity to bacterial filtrates were retained by cellophane membranes. An appreciable purification was thus effected, amounting, on the average, to about a threefold increase in reacting potency per milligram of dry weight and of nitrogen. Attempts to purify bacterial filtrates by the fractional precipitation of their concentrates with dilute alkali, acid, and alcohol were unsuccessful. PMID- 19870605 TI - ANAPHYLACTIC SENSITIZATION WITH CHEMICALLY DEFINITE COMPOUNDS. AB - Injection of sodium atoxyl-diazoamino-sulfoanthranilate into guinea pigs produces an anaphylactic hypersensitiveness to the corresponding azoprotein (Schultz-Dale test). This leads to the conclusion that the injected sodium atoxyl-diazoamino sulfoanthranilate first decomposes and then couples in vivo with the body protein to form the corresponding azoprotein and that therefore it is this compound, produced within the organism itself, which sensitizes. PMID- 19870606 TI - CHANGES IN THE CUTANEOUS LYMPHATICS OF HUMAN BEINGS AND IN THE LYMPH FLOW UNDER NORMAL AND PATHOLOGICAL CONDITIONS. AB - Vital dyes injected intradermally enter lymphatic capillaries directly, rendering them visible, and appear later in the draining lymphatic trunks as colored streamers. The method enables one to perceive the state of the lymphatic channels and the rate of lymph flow within them. It yields consistent results when tested under physiological conditions known to increase or decrease lymph flow. In the horizontally placed normal limb at rest there is slight lymph flow. In a normal leg or arm hanging downward lymph flow ceases although fluid in the limb increases. When a previously dependent arm is raised above the head, or when the foot of a seated subject is propped on a table, lymph flow in the raised limb becomes active. It ceases in the skin of an arm subjected to partial obstruction of the veins by pressure from without, but very active lymph flow appears during the reactive hyperemia which follows upon the release of venous obstruction. It is still greater following release of total circulatory obstruction, and seems to be the same whether or not the limb has previously been engorged with blood. In the ischemic patches which appear in the skin of a limb during total circulatory obstruction (Bier's spots) the lymphatic capillaries are definitely and considerably constricted, whereas they are slightly dilated in the purple, congested regions of the skin round about. On release of obstruction there occurs a strikingly rapid, equal lymphatic drainage from both regions. The significance of all the findings is discussed. When dye is injected intradermally and the skin sucked, much of the foreign material is driven into the lymphatics draining the injected area. PMID- 19870607 TI - THE LYMPHATICS AND LYMPH FLOW IN THE EDEMATOUS SKIN OF HUMAN BEINGS WITH CARDIAC AND RENAL DISEASE. AB - Local intradermal injections of dye have disclosed the fact that the skin lymphatics in regions of cardiac edema are patent, full of fluid and much widened. Intercommunication between them is ready and dye escapes from them more rapidly than from the vessels of normal skin. A retrograde distribution of dye by way of the lymphatics often occurs and it may pass unseen along the deeper channels to emerge in the skin at unexpected, distant situations. A valvular incompetence of the lymphatics consequent on dilatation would appear to be the cause of these phenomena. In regions of cardiac edema lymph stagnates, despite the fact that the channels are open. In nephritic edema the lymphatic capillaries are wider than normal but not as wide as in cardiac edema. No sign of incompetency of the valves is to be observed. Instead lymph flow is considerably greater than normal, even when edema fluid is accumulating. It was noted to be greater in the periods of fluid equilibrium also and extraordinarily rapid in periods of diuresis. PMID- 19870608 TI - THE MOLECULAR WEIGHT OF ANTIBODIES. AB - 1. Highly purified rabbit Type III pneumococcus anticarbohydrate proved to be homogeneous in the ultracentrifuge and its sedimentation constant, 7.0.10(-13), did not differ from that of the principal component of normal rabbit globulin or of immune rabbit globulin containing up to 50 per cent of anti-egg albumin. The molecular weight of antibody in the rabbit is therefore probably very close to that of the principal normal globulin component, namely, 150,000. 2. Highly purified horse Type I pneumococcus anticarbohydrate, on the other hand, was only homogeneous in the ultracentrifuge when prepared from sera stored without preservative. Its sedimentation constant, 18.4.10(-13), coincided with that of the principal globulin component in most of the Felton solutions and purified antibody solutions studied. The molecular weight of pneumococcus anticarbohydrate in the horse is probably three to four times that of the principal normal globulin component. 3. The significance of the differences between pneumococcus anticarbohydrate formed in the rabbit and in the horse is discussed. 4. Results are given of ultracentrifuge studies on the molecular species in solutions of egg albumin-anti-egg albumin specific precipitates dissolved in excess egg albumin. The implications of the results are discussed. PMID- 19870609 TI - ANTIDIURETIC PITUITARY SUBSTANCE IN BLOOD, WITH SPECIAL REFERENCE TO THE TOXEMIA OF PREGNANCY. AB - A method is described for the quantitative extraction of posterior pituitary antidiuretic substance from blood with which it has been mixed in vitro and in vivo for experimental purposes. With this procedure, it is found that a similarly extractable active substance may be detected as a normal constituent of dog and human blood. The data obtained from the blood of normal pregnancies and several cases of early toxemia, do not indicate any causal relationship between the presence of this substance in the circulating blood and the early symptoms (hypertension, edema, albuminuria) of the toxemia of pregnancy. PMID- 19870610 TI - BLOOD PLASMA PROTEIN REGENERATION AS INFLUENCED BY INFECTION, DIGESTIVE DISTURBANCES, THYROID, AND FOOD PROTEINS : A DEFICIENCY STATE RELATED TO PROTEIN DEPLETION. AB - When blood plasma proteins are depleted by bleeding, with return of washed red cells (plasmapheresis), it is possible to bring dogs to a steady state of low plasma protein in the circulation and a uniform plasma protein production on a basal diet. Such dogs become test subjects by which the effect of various factors on plasma protein regeneration can be measured. Dogs previously the subjects of plasmapheresis, during long rest periods appear to increase their stores of plasma protein building materials and their blood plasma protein concentrations above former normal levels. A sterile abscess (turpentine) induces a marked reduction in plasma protein regeneration in these test dogs consuming an ample basal diet. The sharp reduction during the initial 24 hours may in part reflect an extravasation of plasma protein into the injured tissue but there also appears to develop a true disturbance of the mechanism which produces plasma proteins. Digestive disturbances interfere seriously with plasma protein production. Whereas large quantities of live yeast upset digestion and form no plasma protein, autoclaved yeast is well utilized, having a potency ratio of 4.4. Amino acids have been tested inadequately. A mixture of cystine, glutamic acid, and glycine does seem to have a definite effect upon protein metabolism and plasma protein production. Iron, under the conditions of these experiments, does not influence the output of plasma proteins. Liver extract (parenteral) is also inert. The proteins of red blood cells when added to the diet are poorly utilized for plasma protein formation and show a potency ratio of only 10.1. Kidney protein added to the kidney basal diet shows a potency ratio of about 5 as compared with 4.6 for that basal diet. A digest of beef stomach and rice polishings shows a potency ratio of about 7.9. Dried powdered serum shows a potency ratio of 3.5, which is much less than fresh serum (2.6). Powdered thyroid fed in doses sufficient to accelerate body metabolism shows no distinct effect upon plasma protein production not attributable to the protein in the thyroid powder itself. Long periods (25 to 30 weeks) of plasma depletion and basal diet intake remove much protein from body fluids and tissues. Associated with this protein depletion the dog loses its appetite and may vomit some food. There is loss of hair, a tendency to skin ulceration, and a distinct lowering of resistance to infection. The plasma protein output may fall to fasting levels in spite of food intake sufficient to maintain weight. We believe this condition to be a deficiency state related to severe depletion of the essential protein matrix of the body cells. PMID- 19870611 TI - LIVER FUNCTION AND BLOOD PLASMA PROTEIN FORMATION : NORMAL AND ECK FISTULA DOGS. AB - Normal dogs and two Eck fistula dogs, receiving a daily diet containing an average of 1 gm. of vegetable protein per kilo of body weight, showed after average intervals of 7 to 9 weeks, slight decreases in amounts of circulating plasma protein (Table 21). A third Eck fistula dog under similar circumstances was unable to maintain its plasma protein concentration above the edema level. This dog by biopsy was shown to have an abnormal liver and the evidence indicated that the other organs were normal. The animal showed active thirst and diuresis as compared with controls (Table 25). This Eck fistula dog had less than one tenth the capacity of the normal dog to form new plasma protein when various food proteins were added to the basal diet, and no significant quantitative differences in the relative potency of these foods (liver, kidney, heart muscle, soy bean, salmon) could be distinguished (Table 22). It appears that the liver abnormality is responsible for this abnormal reaction. This observation gives strong support to the thesis that the liver is actively concerned with fabrication of new plasma protein. PMID- 19870612 TI - THE DISTRIBUTION IN THE BLOOD AND LYMPH OF PNEUMOCOCCUS TYPE III INJECTED INTRAVENOUSLY IN RABBITS, AND THE EFFECT OF TREATMENT WITH SPECIFIC ANTISERUM ON THE INFECTION OF THE LYMPH. AB - Experiments are described which show that in rabbits infected intravenously with virulent Type III pneumococci, these organisms are found not only in the thoracic duct lymph, as previously reported, but also in lymph from the cervical and leg lymphatics. The nonmotile bacteria must have crossed both vascular and lymphatic endothelium in reaching the lymph. Intracellular transportation by phagocytes is apparently not the means by which this is effected. The intravenous and intraperitoneal injection of large amounts of homologous type-specific antibody fails even after many hours to terminate or permanently reduce the pneumococcal infection of the lymph. The failure of antiserum to sterilize the lymph is discussed. PMID- 19870613 TI - A QUANTITATIVE STUDY OF THE CROSS REACTION OF TYPES III AND VIII PNEUMOCOCCI IN HORSE AND RABBIT ANTISERA. AB - 1. A preparation of the specific polysaccharide of Type VIII pneumococcus is described in which the use of heat, strong acid, and alkali were avoided. 2. Quantitative estimations are given of the homologous and cross reacting precipitin and agglutinin in Types III and VIII antisera produced in the rabbit and in the horse. Quantitative data are also given on the mechanism of the Type VIII precipitin reaction and the cross reaction between the Type III polysaccharide and Type VIII antipneumococcus horse serum. 3. The significance of the data is discussed. PMID- 19870614 TI - REINFECTION (SECOND ATTACK) IN EXPERIMENTAL POLIOMYELITIS. AB - Monkeys which have recovered from an attack of experimental poliomyelitis are subject to reinfection by the nasal route. Second attacks of the disease result from inoculation with the specimen of virus used to produce the first attack and with specimens of different origin. Reinfection takes place in monkeys which have recovered from mild and from severe attacks and in convalescent animals which have been subjected to hyperimmunization. The 2 year quiet period proposed by Still to separate relapses from second attacks, judging from the monkey, is probably excessive. Until greater attention is given the reinfections of varying intensities in man, conclusions on this point must be wholly tentative. PMID- 19870615 TI - THE CULTURE OF WHOLE ORGANS : I. TECHNIQUE OF THE CULTURE OF THE THYROID GLAND. AB - 1. A technique has been developed for the transplantation of the whole thyroid into the Lindbergh pump, and its perfusion, without the occurrence of infection, emboli, and other complications. 2. The gland remains alive during the period of perfusion, which lasted from 3 to 21 days. 3. The technique is simple enough to be used as a routine procedure for physiological or pathological studies of the thyroid gland. PMID- 19870616 TI - EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTI-KIDNEY SERUM : II. CLINICAL AND FUNCTIONAL STUDIES. AB - The glomerulonephritis induced in rats by nephrotoxin was characterized clinically during its initial phase by severe albuminuria, cylindruria, and anasarca, but not by hematuria. Rapidly fatal nephritis was produced by injecting relatively large amounts of anti-kidney serum at frequent intervals. In such cases the blood urea mounted rapidly; the urea clearance fell; and death occurred within about 2 weeks. A milder nephritis of the chronic type was induced by giving smaller quantities of anti-kidney serum in either single or divided doses. In these instances there was no immediate alteration of the urea clearance. Lipemia and plasma protein deficit appeared with the development of anasarca. The majority of rats which survived the initial stage of this experimental nephritis continued to show marked albuminuria with casts until they died or were sacrificed months later. Some of these animals showed retardation of growth and a progressive fall of the urea clearance. Terminally there developed marked retention of urea, plasma protein deficit, anemia, and hypertension. PMID- 19870617 TI - EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTI-KIDNEY SERUM : III. PATHOLOGICAL STUDIES OF THE ACUTE AND CHRONIC DISEASE. AB - Administration of the relatively organ specific antibody, so called nephrotoxin, present in anti-kidney serum, is followed by a diffuse glomerulonephritis. This is characterized early by swelling of the intercapillary substance of the glomerular tuft and by tubular degeneration. Fibrin thrombi are only present in the glomerular capillaries when the injection of anti-kidney serum results in a severe anaphylactoid reaction, and are due to factors other than nephrotoxin. The urinary abnormalities which develop in all rats after a suitable injection of nephrotoxin usually continue until the animal dies or is sacrificed. Microscopic renal lesions of the early phase merge into scarring of the glomeruli and tubules. Histological study of those animals which die from 3 to 11 months after treatment reveals a chronic progressive glomerulonephritis with generalized vascular lesions. PMID- 19870618 TI - EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTI-KIDNEY SERUM : IV. PREVENTION OF THE INJURIOUS EFFECTS OF NEPHROTOXIN IN VIVO BY KIDNEY EXTRACT. AB - A saline extract of perfused rat kidney administered intravenously to rats immediately before injecting an anti-rat-kidney serum, by the same route, prevents renal damage. A preliminary injection of physiological salt solution or of an extract of perfused rat liver has no preventive effect. These findings are a further indication that the nephrotoxic effect induced by anti-kidney serum is dependent upon a relatively organ specific antibody, nephrotoxin. PMID- 19870619 TI - AN IMPROVED AIR-DRIVEN TYPE OF ULTRACENTRIFUGE FOR MOLECULAR SEDIMENTATION. AB - 1. A description is given of the construction details and operation characteristics of an improved type of air-driven ultracentrifuge operating in vacuum and suitable for the determination of sedimentation constants of protein molecules. 2. The rotor of the centrifuge is made of a forged aluminum alloy; it is oval in shape, measures 185 mm. at its greatest diameter, and weighs 3,430 gm. It carries a transparent cell located at a distance of 65 mm. from the axis of rotation and designed to accommodate a fluid column 15 mm. high. 3. The rotor has been run repeatedly over long periods at a speed of 60,000 R.P.M., which corresponds to a centrifugal force of 260,000 times gravity in the center of the cell. At this speed no deformation of the rotor nor leakage of the cell has been observed. 4. The sharp definition of sedimentation photographs taken at high speed serves to indicate the absence of detectable vibrations in the centrifuge. 5. When a vacuum of less than 1 micron of mercury is maintained in the centrifuge chamber, the rise in the rotor temperature amounts to only 1 or 2 degrees C. after several hours' run at high speed. 6. There has been no evidence of convection currents interfering with normal sedimentation of protein molecules in the centrifugal field. 7. A driving air pressure of about 18 pounds per square inch is sufficient to maintain the centrifuge at a steady speed of 60,000 R.P.M. With a driving pressure of 80 pounds per square inch, it can be accelerated to this speed in less than 20 minutes, and also brought to rest in about the same length of time by the application of the braking system. 8. The adaptation of Svedberg's optical systems to this centrifuge for photographically recording the movement of sedimentation boundaries is described. PMID- 19870620 TI - TISSUE CULTURE STUDIES ON BACTERIAL HYPERSENSITIVITY : IV. PROTECTIVE EFFECT OF IMMUNE PLASMA AGAINST THE DELETERIOUS INFLUENCE OF STREPTOCOCCAL EXTRACT ON HYPERSENSITIVE CELLS. AB - 1. Plasmas from guinea pigs, chronically infected with group C hemolytic streptococci, neutralize the components of bacterial extract which exert a marked toxic action on hypersensitive cells in vitro. 2. The neutralizing capacity of these immune plasmas is relatively specific for the bacterial extract, and is not due to a variable nonspecific effect on normal or hypersensitive tissue cells. 3. A rough correlation between the agglutinin titer and the relative neutralizing capacity of immune plasma suggests that the latter may be a manifestation of antibody action. 4. The tolerance by guinea pigs of chronic hemolytic streptococcal lymphadenitis is explainable, at least in part, by the neutralizing capacity of their plasmas, since such soluble bacterial products as may be absorbed from infectious foci would probably be neutralized before they could exert a deleterious influence on the hypersensitive cells of the animals. PMID- 19870621 TI - STUDIES ON THE SEROLOGICAL TYPING OF STREPTOCOCCUS HEMOLYTICUS. AB - The cross-reactions which interfere with satisfactory serological identification of hemolytic streptococcus are due to anticarbohydrate in the sera used for typing. This antibody can be removed easily by absorption with purified streptococcus carbohydrate, and type identification is then readily established. The serological classification of hemolytic streptococcus from throat infections contracted in New York during 1935 and 1936 showed the predominance of types 4, 13 and 22. Type 13 appeared to be the most serious in initiating rheumatic activity during this period of observation. PMID- 19870622 TI - THE COAGULATION OF BLOOD BY SNAKE VENOMS AND ITS PHYSIOLOGIC SIGNIFICANCE. AB - Nine of the 17 venoms here tested were found capable of coagulating citrated blood or plasma. As has been believed by most workers in the field, 7 of these 9 coagulant venoms convert fibrinogen to an insoluble modification resembling fibrin (Bothrops atrox, Bothrops jararaca, Bothrops nummifera, Crotalus adamanteus, Crotalus horridus, Crotalus terrificus basiliscus, Crotalus terrificus terrificus). The optimum pH for this coagulation was determined for 3 of these, and was found in each case to be approximately pH 6.5, the same as that for the action of thrombin on fibrinogen. Unlike thrombin, however, the fibrinogen-coagulating activity of the venoms was unaffected by the antithrombin elaborated in the course of anaphylactic shock. In addition to coagulating fibrinogen directly, 3 of these venoms (Bothrops atrox, Bothrops jararaca, and to a less extent, Crotalus terrificus basiliscus) acted on prothrombin to convert it to thrombin, without the necessary intervention of either calcium or platelets. Finally, 2 venoms (Notechis scutatus, and to a slight extent, a mixed Micrurus venom), which had no demonstrable effect on purified fibrinogen, nevertheless converted prothrombin to thrombin. Unlike the reaction between the venoms and fibrinogen, this activation of prothrombin has no definite pH optimum, but takes place over a wide zone (pH 5.6-8.3). In the case of Bothrops atrox, there was some indication that the initial velocity of the reaction increased with increasing alkalinity, but that the amount of thrombin ultimately formed decreased. Extraordinarily minute quantities of some of these venoms sufficed to produce a demonstrable activation of prothrombin. Thus, the fer de lance (Bothrops atrox) venom was active in a 1:25,000,000 dilution, and that of the Australian tiger snake (Notechis scutatus) was active in a 1:4,000,000 dilution. The thrombin formed was indistinguishable from that produced by the action of calcium + platelets on prothrombin. Like the latter type of thrombin, and unlike venoms which act directly on fibrinogen, thrombin formed from prothrombin by venom was inhibited by antithrombin. Every one of the 9 non-coagulant venoms in this series destroyed prothrombin; and 5 of these destroyed fibrinogen as well. As is discussed in the text, there is reason to believe that these several properties of the venoms (coagulation and destruction of fibrinogen; activation and destruction of prothrombin) depend on the proteolytic enzymes which they were found to contain. These observations lend further support to the thesis that, in the course of physiological coagulation, (a) calcium plus platelets (or tissue derivative) constitute an enzyme system which reacts with prothrombin to form thrombin, and which is thus analogous to trypsin and to several of the proteolytic venoms here discussed, and (b) the thrombin so formed is itself a proteolytic enzyme which, like papain and the majority of the coagulant and proteolytic snake venoms here studied, reacts with fibrinogen to form a fibrillar gel, fibrin. PMID- 19870623 TI - ELECTROPHORESIS OF PURIFIED ANTIBODY PREPARATIONS. AB - Electrophoretic mobilities of antibody preparations isolated from type specific antipneumococcus horse and rabbit sera, measured over a range of pH values, show that these preparations are distinctly different from normal serum proteins in their electrochemical properties. PMID- 19870624 TI - A QUANTITATIVE THEORY OF THE PRECIPITIN REACTION : IV. THE REACTION OF PNEUMOCOCCUS SPECIFIC POLYSACCHARIDES WITH HOMOLOGOUS RABBIT ANTISERA. AB - 1. The reaction between the specific polysaccharide of Type III pneumococcus and homologous antibody in rabbit sera is quantitatively accounted for by expressions similar to those derived from the mass law for the corresponding horse sera. Preliminary data are also given for the Type I reaction. 2. Differences and similarities of the reaction with antibodies produced by the two animals are discussed. 3. Calculations are made of the equivalent composition of the specific precipitate at various reference points in the reaction range. 4. Certain theoretical and practical implications of the findings are pointed out. PMID- 19870625 TI - CHEMICAL PROPERTIES OF THE PURIFIED SPREADING FACTOR FROM TESTICLE. AB - 1. The factor responsible for the spreading property of testicle extracts was found to be soluble in water, in salt solution, and in acid media. It is relatively stable at high hydrogen ion concentrations, and it is not precipitated or inactivated by hydrochloric acid up to pH 2.0. The spreading substance is not soluble in acetone, ether, alcohol, chloroform, or pyridine. It is inactivated by crystalline trypsin and pepsin at the optimum pH of action of these enzymes. It is not attacked by a crystallized carboxypolypeptidase. The substance does not pass semipermeable membranes which retain proteins. The color tests for proteins are positive. At least 14.2 per cent of the fraction isolated is nitrogen. Taken together these properties are strong evidence that the testicular factor is a protein. 2. A method for the preparation of the spreading factor in relatively pure form is presented and discussed. 3. In addition to the spread, concentrated solutions of the testicular factor are shown to produce a condition of the skin having the characters of edema. PMID- 19870626 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : III. THE PRODUCTION OF PERSISTENT HYPERTENSION IN MONKEYS (MACAQUE) BY RENAL ISCHEMIA. AB - Persistent elevation of systolic and diastolic blood pressure due to renal ischemia has been produced in monkeys (macaque) by the same method previously used for this purpose in dogs. PMID- 19870627 TI - EFFECT OF INTENSE SONIC VIBRATIONS ON ELEMENTARY BODIES OF VACCINIA. AB - Thoroughly washed elementary bodies of vaccinia were inactivated by sonic vibrations with a frequency of about 8900 cycles per second; the inactivation was not accompanied by a disruption of the bodies. Adventitious substances, notably protein, prevented or hindered the inactivation. There is some evidence that oxidation might have played a role in the inactivation. PMID- 19870628 TI - VIRUSES OF POLIOMYELITIS : AN IMMUNOLOGICAL COMPARISON OF SIX STRAINS. AB - Qualitative immunological differences exist between early passage strains or so called human strains of the virus of poliomyelitis. These differences show a relationship to the epidemic source of the virus and are exemplified in this study by 4 strains isolated in different years during an eastern and western epidemic of poliomyelitis. PMID- 19870629 TI - SPONTANEOUS ENCEPHALOMYELITIS OF MICE, A NEW VIRUS DISEASE. AB - 1. The characteristics of a filterable virus obtained from mice found spontaneously paralyzed and showing lesions of encephalomyelitis are described. 2. The course of the disease in mice, following intracerebral inoculation, is briefly as follows: After an incubation period varying from 7 to over 30 days a flaccid paralysis of one of the limbs appears. This paralysis usually spreads rapidly until all four limbs are affected. Young mice are more susceptible than older ones, and very young mice, less than 4 weeks of age, usually die without showing signs of paralysis. 3. Adult mice often show no signs of infection after an intracerebral inoculation of virus. A number of these mice, although showing no signs of paralysis, nevertheless have become infected, a fact which is demonstrated by recovery of the virus from the mice as well as by histopathological studies. 4. Intranasal instillation of the virus is the only other method of producing the infection. This method, however, produces paralysis in only a small percentage of the mice. Following intranasal instillation of the virus, there often develops a slight immunity to a subsequent intracerebral injection of virus. 5. The paralysis in the surviving mice recedes gradually, but a permanent residual paralysis, usually of the hind legs, is almost invariable. Such mice, however, are virus carriers, as the virus can be recovered from the spinal cord for 1 year after infection. 6. Paralyzed mice are immune to a subsequent intracerebral injection of the virus. There is evidence that neutralizing substances are present in the immune mice. A considerable proportion of the mice which have remained well after an intracerebral injection of virus are immune to a second injection. 7. The virus resists the action of 50 per cent glycerine at from 2-4 degrees C. for at least 150 days. It passes all grades of Berkefeld filters with ease. By the use of graded collodion filters, the size of the virus particle has been determined to be probably about 13 to 19 mmicro. 8. The virus of mouse encephalomyelitis is not pathogenic for rhesus monkeys. No evidence of immunological relationship with the virus of human poliomyelitis has been obtained. 9. The anatomical basis of the paralysis is an acute necrosis of the ganglion cells of the anterior horn of the spinal cord. Isolated ganglion cells of the cerebrum also undergo necrosis. Following the acute necrosis of the ganglion cells, there is a marked neuronophagia. A perivascular infiltration is observed in the brain and spinal cord. PMID- 19870630 TI - STUDIES ON HAEMOPHILUS INFLUENZAE : I. INFECTION OF MICE WITH MUCIN SUSPENSIONS OF THE ORGANISM. AB - 1. It has been shown that the ability of virulent S. influenzae to kill mice is enhanced by suspending the organism in mucin. 2. The occurrence of a true infection characterized by in vivo multiplication of the organism has been established. 3. The necessity for using a pure inbred strain of mice for this type of study has been confirmed. 4. The increase in mucin virulence of a strain of H. influenzae by repeated passage through mice has been shown. 5. The usefulness of this method in passive immunization studies has been demonstrated. PMID- 19870631 TI - THE PROBABLE NATURE OF THE INFECTIOUS AGENT OF TRACHOMA. AB - 1. The infectious agent of trachoma can be freed from extraneous bacteria by passage through rabbit testicle. 2. The infectious agent multiplies little, if at all, during such passage, but in many instances retains its infectivity undiminished. 3. No specific changes occur in the rabbit testicle incidentally to the passage. 4. On rare occasion the trachoma agent may be freed from bacteria by intracerebral passage. The brain tissues show no specific reaction. 5. Filtration experiments with Seitz, Kramer, Berkefeld, and Elford filters confirm the general observation that the infectious agent is filterable with difficulty. 6. Tissue culture experiments, with tissues containing the infectious agent (conjunctiva, rabbit testicle, brain, etc.), conducted under a wide variety of conditions, proved uniformly unsuccessful in the cultivation of the agent. 7. The agent is inactivated by bile, AgNO(3), phenol, cocaine, tartar emetic, and gentian violet. Its heat inactivation temperature is between 45 degrees and 50 degrees C., at a time interval of 15 minutes. 8. Attempts to preserve the infectious agent in glycerine were unsuccessful. 9. The accumulated evidence suggests that the infectious agent of trachoma is a virus. PMID- 19870632 TI - STUDIES ON THE SUPRARENAL CORTEX : VI. THE EFFECT OF SUPRARENAL CORTICAL HORMONE UPON THE ELECTROLYTE EXCRETION OF THE INTACT NORMAL DOG. A PROPOSED METHOD OF COMPARATIVE ASSAY. AB - The effect of the administration of suprarenal cortical hormone upon the excretion of sodium and potassium has been studied on normal dogs. It is shown to be qualitatively similar to the effect of this hormone upon suprarenalectomized animals and upon patients with Addison's disease. The phenomenon is proposed as the basis for a suitable method for comparative assay of suprarenal cortical extracts. The method is simple, time saving, and uses a minimum of extract. PMID- 19870633 TI - THE EFFECT OF PROLONGED CULTIVATION IN VITRO UPON THE PATHOGENICITY OF YELLOW FEVER VIRUS. AB - 1. Experimental evidence is presented to show that prolonged cultivation of yellow fever virus in vitro results in a change in its pathogenicity, and that this change varies with the type of tissues used for the cultivation. 2. In the tissue cultures used for the propagation of the virus, three different types of tissues were used. They included whole mouse embryo, chick embryo from which the head and spinal cord had been removed, and testicular tissues of mice and guinea pigs. 3. The changes in the pathogenicity of the virus cultivated for a period of over 3 years in a medium containing the tissues of whole mouse embryo were not striking. The viscerotropic virulence of the virus appeared somewhat diminished, in that when injected subcutaneously into rhesus monkeys or hedgehogs it failed to produce a fatal infection, although there is evidence to indicate that a generalized infection takes place as demonstrated by the appearance of virus in the circulating blood in relatively high concentration during infection. The neurotropic virulence of the virus remained unaltered during the cultivation in this medium. 4. The changes in the pathogenicity of the virus cultivated in medium containing tissues of chick embryo from which the head and spinal cord had been removed were very pronounced. The viscerotropic virulence of the virus was lost to a large extent. When injected subcutaneously into monkeys there was as a rule a very mild generalized infection, as demonstrated by the minimal quantities of virus found in the circulating blood. Its neurotropism was also much diminished. When injected into monkeys intracerebrally, it no longer produced a fatal encephalitis but only a moderate febrile reaction, followed by recovery and solid immunity to reinoculation with a highly virulent strain of virus. When injected intracerebrally into mice, the mortality ratio was not diminished but the incubation period was markedly prolonged. 5. The changes in the pathogenicity of the virus cultivated in medium containing testicular tissues were somewhat similar to those observed after cultivation in chick embryo medium which contained only a minimal amount of nervous tissue. Its viscerotropic affinity had been largely lost and only very small amounts of virus were found in the circulating blood of monkeys inoculated subcutaneously. Given intracerebrally, it produced death from encephalitis in monkeys. The incubation period in mice inoculated intracerebrally with this virus was also prolonged but somewhat less so than with the virus grown in chick embryo tissues without the central nervous system. PMID- 19870634 TI - THE USE OF YELLOW FEVER VIRUS MODIFIED BY IN VITRO CULTIVATION FOR HUMAN IMMUNIZATION. AB - The response of rhesus monkeys to a subcutaneous inoculation with varying amounts of virus modified by prolonged cultivation in vitro has been studied. The tissue components of the medium consisted of chick embryo tissue containing minimal amounts of nervous tissue. The immunity produced in monkeys, as measured by the antibody titer developed, has no relation to the amount of virus inoculated. Monkeys inoculated subcutaneously with the tissue culture virus are rendered immune to a subsequent injection of a highly virulent yellow fever virus. This resistance is already present 7 days after vaccination. The subcutaneous inoculation of the culture virus into immune persons leads to a substantial increase of the serum antibody titer. The results of vaccinating eight normal persons with culture virus are presented. The reactions were minimal. The highest temperature recorded following vaccination was 37.4 degrees C. The sera taken from the eight vaccinated persons 2 to 4 weeks after inoculation with the tissue culture virus showed the presence of yellow fever antibodies. PMID- 19870635 TI - THE ADAPTATION OF UNMODIFIED STRAINS OF YELLOW FEVER VIRUS TO CULTIVATION IN VITRO. AB - 1. In a search for suitable tissues for the cultivation of yellow fever virus in vitro, mouse embryos were inoculated with this virus in utero. A titration for virus content of the various organs of the embryos indicated that the virus was present in the brain in greatest concentration. 2. Unmodified strains of yellow fever virus were readily adapted to cultivation in vitro in a medium consisting of minced mouse embryo brain tissue and Tyrode solution containing 10 per cent normal monkey serum. 3. After a continued cultivation in mouse embryo brain tissue cultures for twenty to twenty-five subcultures, these strains were readily adapted to cultivation in whole mouse embryo tissue medium. 4. There is evidence to indicate that a prolonged cultivation of the virus in mouse embryo brain medium increases its neurotropic properties. 5. Attempts to employ monkey tissues for in vitro cultivation of yellow fever virus gave entirely negative results. PMID- 19870636 TI - TOXEMIA OF PREGNANCY IN THE RABBIT : I. CLINICAL MANIFESTATIONS AND PATHOLOGY. AB - The clinical manifestations and pathology of a disorder associated with pregnancy in the rabbit have been described. The disorder bears a close analogy to toxemia of pregnancy in man and offers an experimental approach to the problems associated with that condition. The evidence at hand indicates that the disorder is of endogenous origin and arises from a disturbance of functions concerned in reproductive processes. PMID- 19870637 TI - INFECTIOUS CATARRH OF MICE : I. A NATURAL OUTBREAK OF THE DISEASE. AB - A natural outbreak of an infectious catarrh in a colony of Swiss mice is reported. The disease was generally characterized by a peculiar chattering sound during life and by a rhinitis, an otitis media, and a pneumonia at autopsy. The pneumonia was slowly progressive and terminated fatally in a high percentage of cases. The mortality in a group of 75 naturally infected mice was 95 per cent over a period of 11 months. The disease was readily reproducible in susceptible mice by the nasal instillation of exudate from any locus of infection. It was also transmissible by direct contact. In both naturally and experimentally infected animals there was an incubation period of 10 days or more before symptoms were apparent. Recovery from the disease was not observed. PMID- 19870638 TI - INFECTIOUS CATARRH OF MICE : II. THE DETECTION AND ISOLATION OF COCCOBACILLIFORM BODIES. AB - Small Gram-negative cells resembling the so called coccobacilliform bodies of fowl coryza were regularly found in the nasal and middle ear exudate of mice naturally and experimentally infected with catarrh. These bodies were successfully isolated from exudates and cultivated in tissue cultures. There was no microscopic evidence, however, of their multiplication in ordinary nutrient media enriched with blood. They were filterable through collodion membranes with an average pore size of 640 mmicro and, hence, separable from secondary bacteria. The size of the bodies in stained films averaged between 0.3 and 0.4micro. A second organism cultivable in fluid blood media with the formation of compact clumps and similar to the X bacillus of chickens was also isolated from infected mice. PMID- 19870639 TI - INFECTIOUS CATARRH OF MICE : III. THE ETIOLOGICAL SIGNIFICANCE OF THE COCCOBACILLIFORM BODIES. AB - Evidence is presented that the etiology of infectious murine catarrh is specifically referable to the coccobacilliform bodies. The disease was regularly produced in normal mice by the nasal instillation of primary tissue cultures. In the presence of the X bacillus, transfers of primary cultures were usually uninfective. Pure cultures, however, retained their pathogenicity through as many as 12 transfers. The onset and progress of the experimental disease were somewhat retarded in comparison with the natural disease, but in general there was a close parallel. Mice injected with cultures did, however, show a significant decrease in the incidence of rhinitis. Transmission by direct contact was demonstrated in the presence of a rhinitis but not in its absence. PMID- 19870640 TI - THE ACTION OF IMMUNE SERUM ON HUMAN INFLUENZA VIRUS IN VITRO. AB - Studies have been conducted on the effect of immune serum upon a strain of human influenza virus (PR8) grown in chick embryo tissue culture medium. The results have demonstrated (a) that when cells are exposed to the action of immune serum of high titer and subsequently washed freely, these cells support the growth of virus as well as cells treated with normal serum; (b) that, in agreement with the results of other workers, when virus is added to cell suspensions before the addition of immune serum of low titer, virus survives in the cells; (c) that when mixtures of immune serum of low titer and virus are added to cells, there is little evidence of survival or multiplication of the virus. Furthermore, when immune serum of high titer is used the virus is inactivated regardless of whether the cells are first exposed to virus or immune serum. Finally, virus mixed with a strong immune serum is inactivated in the absence of cells, as shown by the fact that centrifugation at high speeds of such serum-virus mixtures yields no active virus, whereas normal serum-virus mixtures yield fully active virus. PMID- 19870641 TI - THE AUTOLYTIC SYSTEM OF PNEUMOCOCCI. AB - 1. Living pneumococcus cells contain a group of enzymes, the bacteriolytic system, capable of causing the lysis of heat-killed pneumococci (R and S variants irrespective of type derivation). This lysis expresses itself by a loss of the Gram staining reaction, a disintegration of the cell body, and a clearing of the bacterial suspension. 2. Under certain conditions of treatment with the bacteriolytic complex, it is possible to render the cocci Gram-negative without changing their characteristic morphology, or causing any appreciable clearing of the cell suspension. 3. The enzyme responsible for this change has been partially purified, and some of its properties described. 4. The cellular structure which is responsible for the Gram-positive reaction of pneumococci is resistant to proteolytic enzymes, and is still present when tryptic digestion has reduced the heat-killed cell to a body which has lost 75 per cent of its original weight, and contains only 8 per cent nitrogen. 5. The same enzyme preparation which attacks pneumococci is also capable of liberating reducing sugars from some acetyl amino glucose glucuronides of animal and bacterial origin. The possibility is considered, and discussed, that one and the same enzyme in the autolytic complex is capable of attacking both types of substrates. PMID- 19870642 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : III. A REACTION MECHANISM AND A QUANTITATIVE THEORY. AB - 1. By the application of an absolute, quantitative microchemical method for the estimation of agglutinins, precise data have been obtained on the course of the agglutination of Type I pneumococcus by homologous anticarbohydrate. 2. Within the limitations imposed by the necessity for the agglutination reaction to take place at the bacterial surface, the reaction is shown to be analogous to the precipitin reaction and subject to the same laws. 3. The entire process of a typical instance of specific bacterial agglutination has been quantitatively accounted for on a purely chemical basis and expressed in the form of equations derived from the law of mass action. 4. Experimental verification of predictions based on the theory has shown a fundamental difference between this instance of specific bacterial agglutination and the commonly adduced analogies, and necessitated a revision of current conceptions regarding the role of electrolytes and of physical forces in the reaction. PMID- 19870643 TI - INFECTIOUS MYXOMATOSIS OF RABBITS : PREPARATION OF ELEMENTARY BODIES AND STUDIES OF SEROLOGICALLY ACTIVE MATERIALS ASSOCIATED WITH THE DISEASE. AB - From the results of the experiments described in this paper it is obvious that large amounts of elementary bodies of myxoma can be obtained in a relatively pure state by means of the methods used. Furthermore, it is evident that infectious myxomatosis is a viral disease in which elementary bodies of the same order of magnitude as vaccinal elementary bodies play a conspicuous ro1e in that they either represent the etiological agent or are intimately associated with it. The bodies are specifically agglutinated by antimyxoma serum and are agglutinated to a less extent by serum from rabbits convalescing from fibroma, a disease closely related to myxoma. In virus-free filtrates of emulsions prepared from infected skin there is a soluble precipitinogen or precipitinogens specific for the malady. Moreover, a specific precipitinogen or precipitinogens are demonstrable in virus-free serum of animals acutely ill as a result of extensive infection with myxoma virus. It is believed that this is the second viral disease, yellow fever (14) being the first, in which a specific soluble antigen free from virus has been found in the serum of ill animals. PMID- 19870644 TI - MECHANISM OF THE LYSIS OF PNEUMOCOCCI BY FREEZING AND THAWING, BILE, AND OTHER AGENTS. AB - PNEUMOCOCCI, LIVING OR DEAD, ARE SOLUBLE IN BILE WHEN: (a) the autolytic enzymes are still present in a potentially active form; (b) conditions are favorable for enzymatic action. Bile solubility of pneumococci involves as a necessary step one, or a few, of the many stages of the autolytic complex. These observations hold true for the disruption of pneumococci by freezing and thawing, by previous desiccation with cold acetone, and by dilute solutions of antiseptics. A possible mechanism is discussed to account for these forms of lysis. PMID- 19870645 TI - THE EFFECT OF THE BACTERIOLYTIC ENZYME OF PNEUMOCOCCUS UPON THE ANTIGENICITY OF ENCAPSULATED PNEUMOCOCCI. AB - 1. Mice immunized with heat-killed cells of virulent pneumococci (Type I) which have been treated with active preparations of the bacteriolytic enzyme, develop a certain degree of type specific resistance to subsequent infection. This active immunity, however, appears to be due to the small amount of free acetyl polysaccharide present in the suspension of digested bacteria, and is always of a less pronounced degree than that obtained with intact heat-killed cells. 2. Virulent pneumococci killed by heat or iodine when subjected to the action of active preparations of the bacteriolytic enzyme lose the antigenic property of stimulating in rabbits the formation of precipitating antibodies for the type specific polysaccharide. 3. The enzyme prepared from S or R pneumococci, irrespective of type derivation, is equally effective against the capsular polysaccharide antigen of any specific type of this bacterial species. 4. The inactivation of the capsular polysaccharide antigen is observed when the cells are merely rendered Gram-negative, without being caused to undergo actual disintegration or lysis. 5. These observations emphasize the importance of minimizing the chances of alterations due to the action of cellular enzymes in the course of preparation of the cell suspension to be used as immunizing agents. PMID- 19870646 TI - PROPAGATION OF RABIES VIRUS IN TISSUE CULTURE. AB - Rabies virus has been propagated in serum-Tyrode solution containing either embryo mouse brain or embryo chick brain. The culture virus reached a titre of 3 x 10(-5) cc. after 4 days' incubation at 37 degrees C., and survived at least 2 months at 5 degrees C. in the liquid or dry state. PMID- 19870647 TI - INFLUENCE OF HOST FACTORS ON NEUROINVASIVENESS OF VESICULAR STOMATITIS VIRUS : I. EFFECT OF AGE ON THE INVASION OF THE BRAIN BY VIRUS INSTILLED IN THE NOSE. AB - 1. After intracerebral injection or nasal instillation of vesicular stomatitis virus in young or old mice, there was no evidence of a generalized, systemic or blood infection. 2. Within 1 hour after nasal instillation of as much as 100,000 M.C.L.D. in young or old mice, no virus (i.e., less than 60 to 70 M.C.L.D.) could be demonstrated in the nasal mucosa. 2 days later and thereafter virus was abundant in the nasal mucosa of young mice, while among old mice it remained undemonstrable in some and present in small amount in others. 3. Virus was not detected in the anterior rhinencephalon of young and old mice within a few minutes and 5 hours after nasal instillation, but was almost uniformly demonstrable in this region, although not in the rest of the brain, on the 2nd day. This indicated that the primary invasion of the brain occurred by the olfactory rather than the fifth nerve pathway. 4. The essential difference in the further pathogenesis of the disease between the young mice which succumb with encephalomyelitis (5th day) and the old mice which survive without showing clinical signs of brain involvement, is in the progression of the virus from the anterior rhinencephalon. In the young the rest of the brain is invaded, while in the old resistant mice it is not, the progression of virus being arrested somewhere in the anterior rhinencephalon. 5. Since minimal amounts of virus injected intracerebrally were shown to be disseminated quickly through the entire brain, killing old as well as young mice, it was clear that virus so inoculated must spread differently from that which reaches the brain by the olfactory pathway. 6. That the arrest of virus progression in the brains of certain old mice is the result of a preexisting, localized barrier, developed with age, and is not due to a rapidly acquired, specific, cerebral immunity was shown by the failure of old mice to resist an intracerebral injection of 1 to 10 M.C.L.D., 2, 3, 4, or 5 days after preliminary nasal instillation. PMID- 19870648 TI - INFLUENCE OF HOST FACTORS ON NEUROINVASIVENESS OF VESICULAR STOMATITIS VIRUS : II. EFFECT OF AGE ON THE INVASION OF THE PERIPHERAL AND CENTRAL NERVOUS SYSTEMS BY VIRUS INJECTED INTO THE LEG MUSCLES OR THE EYE. AB - 1. Injection of vesicular stomatitis virus into the leg muscles of young mice gives rise to flaccid paralysis of the inoculated extremity as the first clinical sign of a disease which is invariably fatal; old mice similarly injected with the largest doses of virus survive without exhibiting any signs of illness. 2. In young mice the virus was shown to multiply at the site of inoculation and to invade the sciatic nerve and spinal cord; there was no evidence of multiplication of virus in the blood or viscera. 3. In old mice, after intramuscular injection of as much as 10 million M.C.L.D., there was no evidence of either local or systemic multiplication; in spite of the persistence of thousands of M.C.L.D. of virus at the site of inoculation for at least 4 days, there was no detectable invasion of the sciatic nerve or the central nervous system. 4. Injection of the virus directly into the sciatic nerve of old mice led to the typical paralytic disease in half the number of animals. 5. For 3 days after intrasciatic injection the virus could be demonstrated in the nerve but not in the spinal cord or brain. At the onset of paralysis (6th day) virus was detectable in the spinal cord but no longer in the inoculated nerve. 6. The capacity of the virus to invade the central nervous system from the nerve but not from the muscle suggested the existence of a barrier in the muscle or myoneural junction. 7. Injection of the virus into the vitreous humor of the eye is followed by a fatal encephalitis in 15 day old mice, but 1 year old mice, with few exceptions, survive without showing signs of disease. 8. The spread of virus in the brains of intraocularly injected, 15 day old mice was too rapid to indicate the pathways which were pursued, but in 21 day old mice there was evidence that the primary pathway was probably along the axons of the optic nerve with decussation to the contralateral diencephalon and mesencephalon, and subsequent early spread to the corresponding occipital cortex. In resistant, old mice, however, no virus was found in any part of the brain. PMID- 19870649 TI - PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR : XIII. SEDIMENTATION OF THE TUMOR AGENT, AND SEPARATION FROM THE ASSOCIATED INHIBITOR. AB - 1. The agent causing Chicken Tumor I can be separated from the other constituents of the tumor filtrate by means of high speed centrifugation. The separation was practically complete when a filtrate of average viscosity (0.018 poise) was submitted to a centrifugal field of 14,000 times gravity for 2 hours. 2. Relative purification of the agent was obtained by means of differential centrifugation and washing in Tyrode's solution or in distilled water. The washed sediment gave opalescent solutions composed of minute particles of approximately, but not exactly, the same size. The dry weight of the active material separated by high speed centrifugation was 0.0008 mg. per cc. of filtrate, or about 1 part per 2800 parts of the total filtrate. 3. The tumor-producing activity of the washed sediment was significantly greater than that of the entire original filtrate. It is suggested that the gain in tumor-producing power was effected by the removal of an inhibiting factor, known to occur normally in chicken tumor extracts. PMID- 19870650 TI - LYMPH NODES AS A SOURCE OF NEUTRALIZING PRINCIPLE FOR VACCINIA. AB - An antiviral principle is elaborated within the regional lymph nodes draining skin into which vaccinia is injected. The immunity conferred by clinical Jennerian vaccination may be largely of lymph node origin. PMID- 19870651 TI - THE MULTIPLICATION OF THE VIRUS OF YELLOW FEVER IN AEDES AEGYPTI. AB - Aedes aegypti have been shown to be capable of multiplying the Asibi strain of yellow fever virus in their bodies. Following the ingestion of infected blood, the content of virus falls for several days, reaching a minimum during the 1st week. It then increases rapidly until quantities of virus greater than those previously encountered can be demonstrated. The actual final amount of virus demonstrable, however, is subject to variations of which we know little. PMID- 19870652 TI - DOES LIVER SUPPLY FACTORS IN ADDITION TO IRON AND COPPER FOR HEMOGLOBIN REGENERATION IN NUTRITIONAL ANEMIA? AB - 1. Our data indicate that the effectiveness of whole liver in the treatment of nutritional anemia in rats induced by a milk diet is directly proportional to its available iron and copper content. The other constituents in liver are not needed for maximum hemoglobin regeneration on a diet of milk, iron, copper, and manganese. 2. Commercial preparations of liver products with iron or iron and copper vary greatly in their hemoglobin-regenerating efficiency in rats with nutritional anemia. The variation is correlated directly with the iron and copper content of the preparation. When the copper-iron ratio was too wide hemoglobin regeneration was checked, although the iron supply was sufficient for optimum regeneration. PMID- 19870653 TI - IMMUNOLOGICAL RELATIONSHIP BETWEEN THE SWINE AND HUMAN INFLUENZA VIRUSES IN SWINE. AB - Swine recovered from infection with either swine influenza or swine influenza virus alone are usually not only immune but refractory to human influenza infection. Swine recovered from infection with a mixture of human influenza virus and H. influenzae suis are usually immune to swine influenza while those recovered from infection with human influenza virus alone are usually not immune to swine influenza. The possible mechanisms involved in the cross-immunity between the influenza viruses are discussed. PMID- 19870654 TI - THE EFFECT OF HEMOPHILUS INFLUENZAE SUIS VACCINES ON SWINE INFLUENZA. AB - Either living or heat-killed H. influenzae suis vaccines, given intramuscularly to swine, elicit an immune response capable of modifying the course of a later swine influenza infection. The protection afforded is only partial and is in no way comparable to the complete immunity afforded by swine influenza virus vaccines. PMID- 19870655 TI - DEMONSTRATION OF PASSIVE IMMUNITY IN EXPERIMENTAL MONKEY MALARIA. AB - A Plasmodium knowlesi infection in rhesus monkeys is almost invariably fatal. This infection, however, may be made chronic by the early administration of antimalarial drugs. The animals then will harbor a chronic infection for an indefinite period. The serum taken from monkeys with chronic infection and injected into those suffering from an acute attack was found to have a definite depressing effect upon the course of the experimental disease. In some instances death was prevented and the acute infection changed into a chronic form; in others, the course of the experimental disease was prolonged. In a similar manner the serum from monkeys harboring a chronic Plasmodium inui infection, when injected into monkeys suffering from an acute attack due to this parasite, was found to be effective in reducing the intensity of the primary infection. The data presented indicate that protective antibodies are produced in the serum of monkeys during experimental malaria infection. PMID- 19870656 TI - CHEMO-IMMUNOLOGICAL STUDIES ON CONJUGATED CARBOHYDRATE-PROTEINS : XI. THE SPECIFICITY OF AZOPROTEIN ANTIGENS CONTAINING GLUCURONIC AND GALACTURONIC ACIDS. AB - 1. Azoprotein antigens containing glucuronic and galacturonic acids give rise in rabbits to specific antibodies. The immune sera show no serological crossing with antigens containing glucose or galactose. 2. The galacturonic acid antigen reacts in antipneumococcus horse serum Type I in high dilutions. 3. Azoprotein antigens containing galacturonic acid, benzene sulfonic and carboxylic acids precipitate in antipneumococcus horse sera of various types but not in normal horse serum. The mechanism underlying these cross reactions is discussed. PMID- 19870657 TI - STUDIES ON THE PHYSIOLOGICAL CONDITIONS PREVAILING IN TISSUE CULTURES. AB - An analysis of some of the physiological factors active in Maitland tissue cultures has been presented in the hope that it may be of some value in clarifying the principles underlying tissue cultures in general. It has been found that the empirically determined necessity of using relatively small amounts of tissue in such cultures is dependent upon the fact that excessive tissue leads to a rapid change of reaction toward the acid side. Whereas tissue may remain viable in an environment as alkaline as pH 9 and over, viability is rapidly destroyed when the reaction approaches pH 6. Evidence is presented to indicate that the changes in electrode potentials which take place in Maitland cultures are not, as has been suggested, the determining factors upon which virus multiplication depends, although they may, of course, be incidentally important. It has been shown that there are fundamental differences between those conditions in Maitland cultures which favor the multiplication of a typical virus and those upon which the growth of the Rickettsiae of typhus fever depends. The virus which we have studied (equine encephalitis virus, western type) multiplies during the period of active tissue metabolism. The maximum virus titrations are obtained at about the time at which metabolism has come to a standstill. Thereafter the virus not only ceases to increase but rapidly deteriorates. The period of viability of the tissue cells themselves is shortened by several days in the presence of virus multiplication. There is some evidence that a temporary acceleration of oxygen uptake takes place during the time of active virus multiplication. Technical difficulties in controlling such experiments prevent certainty in regard to this point. In contrast with the conditions determining the growth of a virus agent in the Maitland cultures the multiplication of Rickettsiae does not begin to any determinable extent until after active cell metabolism has either become stabilized or has ceased. The Rickettsiae continue to grow at a time when the cells are no longer viable. It appears likely that these organisms find the most favorable conditions for growth in cells which are no longer metabolically active but in which some delicately heat-susceptible elements have not yet been disturbed. As a consequence of these observations, frozen and preserved embryonic tissues have been successfully used for Rickettsia cultivation. A report on these experiments will be made in a separate communication. PMID- 19870658 TI - A QUANTITATIVE THEORY OF THE PRECIPITIN REACTION : V. THE REACTION BETWEEN CRYSTALLINE HORSE SERUM ALBUMIN AND ANTIBODY FORMED IN THE RABBIT. AB - 1. The reaction between crystalline horse serum albumin and homologous antibody in rabbit sera is quantitatively accounted for by expressions similar to those derived from the law of mass action for other immune precipitating systems. 2. The reaction of an azo dye prepared from crystalline serum albumin by coupling with diazotized R-salt-azo benzidine was also studied with homologous antibody and anti-serum albumin. 3. Quantitative data obtained on cross reactions with the two antigens differ markedly from data on the corresponding reactions in the egg albumin system and indicate that tyrosine and perhaps histidine, while important in determining the serological specificity of egg albumin, have little connection with the specificity of serum albumin. 4. Calculations are made of the equivalent composition of the specific precipitate at various reference points in the reaction range. PMID- 19870659 TI - A QUANTITATIVE THEORY OF THE PRECIPITIN REACTION : VI. THE REACTION BETWEEN MAMMALIAN THYROGLOBULINS AND ANTIBODIES TO HOMOLOGOUS AND HETEROLOGOUS PREPARATIONS. AB - 1. Quantitative data for both homologous and heterologous precipitin reactions of human, hog, beef, and sheep thyroglobulins show that these reactions have the same mechanism as other instances of the precipitin reaction and may be expressed quantitatively by the same equations derived from the law of mass action. 2. It is shown that all of the added antigen is precipitated in the region of antibody excess and in the equivalence zone, so that in these portions of the reaction range the composition of the specific precipitate may be calculated from the nitrogen precipitated and the amount of antigen nitrogen added. 3. The thyroglobulin-antibody reaction is characterized by low antibody N to antigen N ratios, as would be expected with an antigen of high molecular weight. Molecular ratios varying from 60:1 to 1:1 were calculated for the extremes of the reaction range, indicating a very large number of immunologically reactive groupings on the thyroglobulin molecule. 4. Failure of thyroxine or diiodotyrosine to inhibit specific precipitation was confirmed, but it is shown that this need not mean that these substances do not occur in thyroglobulin, as has been claimed. PMID- 19870660 TI - VARIATION IN THE SIZE OF TRANSPLANTS OF THE PROSTATE AND SEMINAL VESICLE IN THE ANTERIOR CHAMBER OF THE EYE. AB - 1. A method is described with which the two-dimensional size of a transplant in the anterior chamber of the eye may be measured daily with a high degree of accuracy. 2. The size of transplants of the prostate and seminal vesicles varies from day to day and objective evidence indicates that this variation is related to physiologically active testicular tissue. PMID- 19870661 TI - THE PHYSIOLOGICAL RESPONSE OF PROSTATIC AND VESICULAR TRANSPLANTS IN THE ANTERIOR CHAMBER OF THE EYE. AB - 1. With a photographic method for the determination of the size of prostatic and vesicular transplants in the anterior chamber of the eye, it has been possible to follow continuously the response to an injection of a hormone. 2. The results may be briefly summarized as follows: (a) One injection of the gonadotropic substance of pregnancy urine produces a moderate increase in size; (b) subsequent injections of this same substance for a period of at least 3 months are without effect; (c) an alkaline extract of the whole anterior pituitary gland produces a similar increase; (d) all pituitary derivatives are ineffective in the castrated animal; (e) castration brings about a decrease in size that gradually loses velocity; (f) the male sex hormone produces a slight increase in intact, and a variable, at times conspicuous, increase in castrated animals; (g) the female sex hormone provokes a conspicuous increase in both intact and castrated animals; (h) the hormone of the corpus luteum has no effect; and (i) there is no evidence of synergism of the pituitary and male sex hormones nor of antagonism of the male and female sex hormones in adult rabbits. PMID- 19870662 TI - THE RELATION OF BLOOD CHOLESTEROL AND THE SIZE OF PROSTATIC AND VESICULAR TRANSPLANTS IN THE ANTERIOR CHAMBER OF THE EYE. AB - In male rabbits, injections of the female sex hormone result in marked increase in the size of ocular transplants of the prostate and seminal vesicles and a correlated elevation of the blood cholesterol. Other hormones, which cause an increase in the size of the transplants, do not show this correlation. The ingestion of cholesterol with conspicuous increase of the blood cholesterol, has no effect on the size of the transplants. PMID- 19870663 TI - THE CULTURE OF WHOLE ORGANS : II. THE EFFECTS OF PERFUSION ON THE THYROID EPITHELIUM. AB - 1. During the 1st and 2nd day of cultivation of the whole thyroid gland in the Lindbergh apparatus, perfused by a medium containing 20 or 40 per cent homologous serum diluted with glucose-Tyrode, the state of the thyroid epithelium remains histologically normal and even the most delicate cytological details retain their normal aspect. 2. Cultivation over a period up to 6 days need not cause any serious histological alteration of the gland; but cytological examination reveals an increasingly damaged condition of the mitochondria and the Golgi apparatus. These changes seem not to interfere with the life of the cells, however; epithelial culture from the perfused organs yields positive results. 3. The process of cultivation is liable to cause a slight morphological reaction in the thyroid epithelium, which resembles a feeble stimulation of the tissue. 4. Addition of the thyro-stimulating factor from the anterior pituitary to the perfusion fluid causes a stimulation of the cultivated thyroid epithelium which is comparable to, but not so marked as, the corresponding reaction in the living animal. PMID- 19870664 TI - THE CULTURE OF WHOLE ORGANS : III. THE PROBLEM OF ANTIHORMONES STUDIED ON ISOLATED LIVING THYROID GLANDS. AB - 1. Perfusion of isolated thyroid glands from rabbits, made refractory to the action of the thyro-stimulating factor from the hypophysis by repeated injections for 2 months, has shown that in this condition the thyroid epithelium responds to pituitary stimulation. 2. The serum from refractory rabbits does not neutralize completely the thyro-stimulating effect of anterior pituitary extract upon an isolated normal thyroid gland. 3. It is believed that tissues other than the thyroid play a role in bringing about the phenomena which have been described as refractoriness against a prolonged action of the thyro-stimulating pituitary factor. PMID- 19870665 TI - IMMUNIZATION OF GUINEA PIGS WITH A MODIFIED STRAIN OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS. AB - A strain of choriomeningitis virus which was highly virulent for guinea pigs, as isolated from a naturally infected white mouse, has been markedly attenuated for guinea pigs by serial intracerebral passage through white mice. The change of virulence occurred before the 8th serial passage. The modified virus as a rule produces fever in guinea pigs but no other symptoms, and the infection is followed by a very solid immunity. Parallel passages of the same strain through guinea pigs have maintained its high virulence for this species but slightly reduced its pathogenicity for mice. These observations indicate that the differences in virulence for guinea pigs noted before (1, 2) with different strains of choriomeningitis virus obtained from infected stock mice may be due not only to differences in the susceptibility of guinea pigs but also to variations in the virulence of the virus. A marked degree of resistance was demonstrable in several guinea pigs on the 4th, 8th, and 10th day after injection with modified virus, when antivirus could not yet be detected in the serum. Circulating antivirus appears therefore to play a secondary part in their immunity, which seems to be closely associated with the tissues as in mice. PMID- 19870666 TI - ELEMENTARY BODIES OF VACCINIA FROM INFECTED CHORIO-ALLANTOIC MEMBRANES OF DEVELOPING CHICK EMBRYOS. AB - By a method of differential centrifugation and tryptic digestion suspensions of elementary bodies have been prepared from chorioallantoic membranes of chick embryos infected with vaccine virus. The infective titer of the final suspension of elementary bodies was usually the same as that of the original tissue emulsion. Elementary bodies from infected chick membranes were agglutinated as well by antivaccinal serum obtained from different mammalian species as were bodies prepared from inoculated rabbit skin. Seitz filtrates of infected chick material contained soluble precipitable substances of vaccinia; these filtrates and filtrates from infected rabbit skin, respectively, reacted equally well with rabbit serum which contained either L or S antibodies. PMID- 19870667 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : IV. ANAPHYLAXIS INDUCED BY PICRYL CHLORIDE AND 2:4 DINITROCHLOROBENZENE. AB - It has been shown that by the cutaneous administration of simple chemical compounds in small quantities-2:4:6 trinitrochlorobenzene (picryl chloride) and 2:4 dinitrochlorobenzene, the latter a typical incitant of contact dermatitis in man-it is possible to induce true anaphylactic sensitization in guinea pigs, demonstrable by the intravenous injection of protein conjugates and by the Dale technique, using isolated uterine horns. This furnishes strong evidence for the formation of antigenic conjugates following application of substances of simple chemical constitution. Since the anaphylactic state is induced by the same method of administration that gives rise to cutaneous sensitivity, the assumption would appear justified, when one takes into account the chemical properties of the inciting substances, that the formation of conjugated antigens offers an explanation for the skin effects also. In the experiments with picryl chloride, anaphylactic antibodies, and occasionally precipitins, have been demonstrated. The differences between the cutaneous and anaphylactic types of sensitivity are discussed. PMID- 19870668 TI - SPREADING PROPERTIES OF LEECH EXTRACTS AND THE FORMATION OF LYMPH. AB - 1. The injection of leech extracts into the skin increases its permeability, as shown both by the spread of fluid and of foreign particles through the dermis. The spread is followed some hours after the injection by more or less edema of the subcutaneous tissue. 2. A preliminary study of the chemical properties of the leech spreading factor indicates a similarity with the spreading factor prepared from testicle. 3. Attempts to separate the leech spreading and anticoagulating factors showed that the two have practically the same distribution in the leech body, extracts from the separated head being the most active. 4. It is undetermined whether two distinct factors are responsible for the spreading and anticoagulating properties of leech extracts. A chemical similarity is suggested by the fact that agents which affect the activity of one factor have a parallel effect on the other. 5. The mechanism of the spread produced by leech extracts and by other spreading agents is discussed. PMID- 19870669 TI - THE EFFECT OF DIET ON THE SUSCEPTIBILITY OF THE CANINE HEMATOPOIETIC FUNCTION TO DAMAGE BY AMIDOPYRINE. AB - 1. By feeding dogs a black tongue diet and at the same time administering amidopyrine, acute stomatitis and anemia may be produced. 2. Both stomatitis and anemia occur some time before they could be expected to appear as result of the diet feeding alone. 3. The anemia is associated with suppression of maturation of the hematopoietic bone marrow elements. PMID- 19870670 TI - THE COMPOSITION OF SPECIFIC PRECIPITATES IN THE REGION OF ANTIGEN EXCESS. AB - Data are given, for seven different antisera, for the composition of the specific precipitate as a function of the relative proportions of antiserum and antigen used. In the region of antigen excess, a linear relation is found between the ratio of antibody to antigen in the precipitate and the amount of antiserum used. The significance of these results, particularly in their bearing on theories of the precipitin reaction, is discussed. PMID- 19870671 TI - STUDIES ON PULMONARY EDEMA : I. THE CONSEQUENCES OF BILATERAL CERVICAL VAGOTOMY IN THE RABBIT. AB - 1. Bilateral cervical vagotomy in rabbits soon leads to death, usually within 8 to 24 hours. 2. Gradually increasing dyspnea, crises with expulsion of frothy, serous or sanguineous fluid from the mouth and nose, and terminal asphyxia are the important clinical features. 3. Postmortem examination reveals severe acute pulmonary edema and congestion, variable amounts of bronchopneumonia, and evidences of aspiration of food and secretions. This picture is similar to that found in the lungs in the bulbar form of poliomyelitis. 4. These changes are brought about by a combination of factors secondary to bilateral vagotomy: laryngeal paralysis (aspiration of food, slow asphyxia); loss of the vagal innervation of the lungs. 5. Laryngeal paralysis is not an essential factor in the production of severe pulmonary edema and death following bilateral cervical vagotomy. 6. To denote the pathogenesis of this type of edema, the term neuropathic pulmonary edema is employed. PMID- 19870672 TI - STUDIES ON PULMONARY EDEMA : II. THE PATHOGENESIS OF NEUROPATHIC PULMONARY EDEMA. AB - 1. Guinea pigs die shortly after bilateral cervical vagotomy, even when continuous artificial respiration effected through a tracheal cannula is carried out. Death is caused by severe pulmonary edema and congestion. 2. Direct observation of the lungs after bilateral vagotomy demonstrates that pulmonary edema develops gradually and increases slowly in amount and severity. Congestion precedes and accompanies the development of the edema. 3. Neuropathic pulmonary edema in the guinea pig is caused by disturbance to or abolition of the pulmonary vasomotor nerves. 4. The evidence obtained by experiments on animals suggests that neuropathic pulmonary edema in man is caused by disturbances, either central or peripheral, to the vasomotor control of the pulmonary vessels. PMID- 19870673 TI - PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : I. THE MOUSE PROTECTIVE VALUE OF TYPE I SERA WITH REFERENCE TO THE PRECIPITIN CONTENT. AB - The ability to carry out with some measure of precision mouse protection tests for the estimation of potency of antipneumococcus sera has made possible the correlation of the protective potency with the amount of specifically precipitable protein. With antipneumococcus rabbit sera these protective ratios are relatively constant and higher than those with immune horse serum. Type I antipneumococcus horse sera, on the other hand, show no such constancy but fall into two groups; and there is as yet no simple method for determining to which group a serum belongs. PMID- 19870674 TI - PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : II. IMMUNOLOGICAL FRACTIONATION OF TYPE I ANTIPNEUMOCOCCUS HORSE AND RABBIT SERA. AB - The generally held view has been that in any immune serum only a single antibody would be induced by and react with a single antigen. Were this true the various manifestations of antibody activity should show a quantitative parallelism. It has already been shown (1), however, that with antipneumococcus horse serum the mouse protective potency does not parallel the maximum amount of specifically precipitable protein except within certain well defined groups of antisera. The simplest explanation of this situation is that different horses form antibodies differing in specific protective capacity, but from our studies it seems probable that in any immune serum there may occur a mixture of antibodies which, while directed against the same antigen, possess different protective capacities, different avidities, etc. It would now appear that this latter hypothesis is the more tenable since the experiments here reported indicate the existence of antibodies of various protective potencies in horse antisera. It would not be unreasonable to hold that the antibodies of a single serum represent a series of substances with varying properties. On the basis of the present immunological fractionation experiments, the following deductions seem permissible. 1. Antipneumococcus horse sera must contain at least three, possibly many, antibody substances which react with the capsular polysaccharide. These are: (a) A substance which precipitates upon the addition of a relatively small amount of polysaccharide. This antibody possesses a low protective potency. (b) A substance which is precipitated with intermediate amounts of polysaccharide and which possesses an extremely high protective value. (c) A third substance which is precipitated only with the addition of relatively large amounts of polysaccharide. The protective value of this antibody is very low It may represent a degraded form. 2. With antipneumococcus rabbit serum the situation is somewhat simpler. This is in accord with the fact that with Type I antipneumococcus sera from this species there is a direct proportionality between the amount of specifically precipitable protein and the protective potency of the serum (1). The results with antipneumococcus rabbit serum indicate the existence of at least two antibody substances: (a) An antibody with high protective value which makes up the greater proportion of the total content. (b) A second substance which is precipitated only upon the addition of relatively large amounts of capsular polysaccharide. The existence of this second antibody is not clearly demonstrated by the present findings but the lower protective ratios obtained as greater amounts of antibody are removed probably indicate its existence. This may also represent degraded material. The observations on the antibodies of both horse and rabbit antisera will be supported by experiments with immunochemical fractionation which will be reported in a subsequent paper. PMID- 19870675 TI - PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : III. IMMUNOCHEMICAL FRACTIONATION OF TYPE I ANTIPNEUMOCOCCUS HORSE AND RABBIT SERA. AB - Immunological and immunochemical fractionation of Type I antipneumococcus horse and rabbit sera have demonstrated the existence of several forms of immune protein, each fraction behaving as a type specific antibody, but differing from the others in chemical and immunological properties. PMID- 19870676 TI - THE ABSORPTION OF PROTEIN SOLUTIONS FROM THE PULMONARY ALVEOLI. AB - Horse serum, crystallized hemoglobin, and crystallized egg albumin have been injected into the lung alveoli of dogs in which the entrances of the right lymphatics have been tied and the thoracic duct cannulated. Samples of blood and lymph have been taken following this injection. Only after several hours in the case of the horse serum and hemoglobin have these proteins been detected by immunological methods and invariably they have appeared first in the blood. Egg albumin also enters the blood capillaries, but much more rapidly than the other two proteins, due probably to the smaller molecular size. PMID- 19870677 TI - FURTHER OBSERVATIONS ON VITAMIN C THERAPY IN EXPERIMENTAL POLIOMYELITIS. AB - 1. A group of 181 monkeys were infected intracerebrally with amounts of virus ranging from 0.01 to 0.05 cc. of a 10 per cent virus suspension. At different intervals following infection treatment of these animals was begun with daily injections of 5 to 100 mg. of natural vitamin C for a period of 2 weeks. Of 89 monkeys treated on the 1st or 2nd day of infection 26 (29.2 per cent) survived without showing any evidence of paralysis; of 53 monkeys treated on the 3rd day of the infection 23 (43.3 per cent) survived without showing any evidence of paralysis; of 39 monkeys treated on the 5th day of the infection 9 (23 per cent) survived without showing any evidence of paralysis. 2. A group of 101 monkeys were infected intracerebrally with amounts of virus ranging from 0.05 to 0.1 cc. of a 10 per cent virus suspension. At different intervals following infection treatment of these animals was begun with daily injections of 5 to 100 mg. of synthetic vitamin C for a period of 2 weeks. Of 25 monkeys treated on the 1st day of infection 2 (8 per cent) survived without showing any evidence of paralysis; of 26 monkeys treated on the 3rd day of the infection 5 (19.2 per cent) survived without showing any evidence of paralysis; of 50 monkeys treated on the 4th and 5th day of the infection 4 (8 per cent) survived without showing any evidence of paralysis. 3. The above two groups of treated animals were accompanied by a group of 98 control monkeys which were infected intracerebrally with the same amounts of virus and remained untreated. In this group there were 5 (5.1 per cent) animals which survived without showing any evidence of paralysis. 4. The figures, taken as a whole, show that among 181 monkeys treated with natural vitamin C 58 (32 per cent) survived without paralysis, and among 101 monkeys treated with synthetic vitamin C 11 (10.8 per cent) survived without paralysis. In comparing the percentage of non-paralytic survivors of the two treated groups with that of the untreated controls (5.1 per cent) it is found that about six times as many animals escaped paralysis following treatment with natural vitamin C as did the corresponding controls. In the group of animals treated with synthetic vitamin C, on the other hand, there were only about twice as many non-paralytic survivors as among the controls. 5. The results obtained in this investigation, as far as they are concerned with the therapeutic effect of natural vitamin C in experimental poliomyelitis, are in close agreement with the data previously published. PMID- 19870678 TI - VITAMIN C CONTENT OF MONKEY TISSUES IN EXPERIMENTAL POLIOMYELITIS. AB - 1. The concentrations of reduced ascorbic acid present in the tissues of normal rhesus monkeys are of a magnitude in keeping with the values found for other animal species which are incapable of synthesizing vitamin C. These concentrations are subject to distinct increase by prolonged parenteral administration of ascorbic acid. 2. The amounts of vitamin C present in nervous tissue and the suprarenals of monkeys, paralyzed as the result of poliomyelitis infection, are slightly below the normal average when examined at the height of paralysis or in early convalescence. The figures show a tendency for a return to normal or slightly hypernormal levels concomitant with the progress of convalescence. 3. Vitamin C titrations of the tissues of monkeys which had received parenteral injections of ascorbic acid during the incubation period of poliomyelitic infection give different results according to whether such animals develop paralysis or survive without paralytic symptoms. In paralyzed C-treated monkeys the vitamin C levels are practically identical with those of normal C prepared monkeys. Markedly higher values, however, are obtained with non paralytic survivors in the early stages of their survival. As the period of survival lengthens normal figures prevail again. 4. The data are discussed in their relationship to the success or failure of vitamin C therapy in experimental poliomyelitis. PMID- 19870679 TI - THE INFLUENCE OF PROLONGED, INTENSIVE PLASMAPHERESIS UPON THE ABILITY OF THE ORGANISM TO REGENERATE SERUM PROTEIN. AB - 1. When the dog is subjected to quantitative plasmapheresis and fed appropriate "synthetic" artificial rations, it is possible to evaluate the ability of the organism to regenerate serum protein from both exogenous and endogenous sources. Approximately 44 per cent of the protein, casein, fed in excess of the minimal amount needed normally to meet the general nitrogen requirements, is utilized for the formation of new serum protein. Under our experimental conditions the dog can regenerate each week solely from endogenous sources approximately 0.6 gm. of this blood protein per kilo of optimal body weight. This is equivalent to about 21 per cent of the total amount of serum protein normally present in the plasma. 2. When the dog is fed an adequate protein diet and is subjected to a regime of prolonged intensive plasmapheresis (period of 16 consecutive weeks), no impairment in the ability of the organism to regenerate serum protein from either exogenous or endogenous sources occurs. Under our conditions of experimentation the dog appears to be able to form each week an amount of the blood protein approximately equal to that normally present in the plasma. Because of this remarkable ability of the normal organism to regenerate rapidly serum protein over a relatively long period of time, it seems that loss of protein alone in conditions of Bright's disease cannot be the etiologic agent responsible for the persistence of the hypoproteinemia. An additional factor, the "specific" ability of such individuals to regenerate serum protein, must be taken into consideration. PMID- 19870680 TI - THE INFLUENCE OF PREGNANCY AND LACTATION UPON THE REGENERATION OF SERUM PROTEIN. AB - 1. In view of the markedly short period of gestation in the dog and in view of the relatively large litters that are cast and nursed, this species when compared with the human being undergoes a much greater physiological strain during pregnancy and lactation. This is evidenced by marked decreases in the hematocrit values, in total cell volumes and in the serum protein concentrations, by an appreciable plasma hydration, and in some cases by significant reductions in the total circulating serum protein. 2. When pregnant dogs are fed a protein-free diet at a high level of caloric intake and are subjected to our standardized plasmapheresis technique, it is possible to deplete the animal of its reserve serum protein stores and reduce the serum protein concentration to the basal level (3.5 to 4.2 per cent) within the extremely short period of from 2 to 3 days. This indicates that the dog during pregnancy possesses a very limited amount of reserve serum protein. 3. Once the basal serum protein level is attained, the pregnant or lactating dog exhibits a marked impairment in its ability to regenerate serum protein. The synthesis of body proteins in the fetus during pregnancy and the milk proteins during lactation is considered to be actually an internal plasmapheresis, leading to a depletion of the serum protein by the preferential utilization of the materials from which this complex is made. These parasitic effects on the maternal organism are believed to be of primary importance, over and above any hydremia, in causing the lowered serum protein concentrations characteristic of pregnancy. PMID- 19870681 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : VI. THE EFFECT OF SECTION OF ANTERIOR SPINAL NERVE ROOTS ON EXPERIMENTAL HYPERTENSION DUE TO RENAL ISCHEMIA. AB - Section of the anterior spinal nerve roots from the sixth thoracic to the second lumbar inclusive did not prevent or significantly and permanently reduce hypertension produced by constricting the main renal arteries of dogs. The significance of these results for the pathogenesis of human and experimental hypertension is discussed. PMID- 19870682 TI - ON THE MODE OF ACTION OF SULFANILAMIDE IN EXPERIMENTAL STREPTOCOCCUS EMPYEMA. AB - Sulfanilamide prevents the evolution of an invariably fatal streptococcus empyema in rabbits when it is given repeatedly and in sufficient doses subcutaneously. Complete sterilization of the inoculated cavity occurs on approximately the 2nd day. The serum, defibrinated blood and artificial pleural exudate of similarly treated animals inhibits the growth of the same streptococcus in the test tube but even repeated doses of such treated blood serum fail to sterilize the culture. The coccal chains grown in such drugged serum are elongated and present pleomorphic and metachromatic organisms and may give rise to colonies that are at first less predominantly mucoid in appearance. Such organisms have, however, lost little if any of their virulence. Cooperation on the part of locally derived clasmatocytes is apparently required in complete sterilization of the animal body. This conclusion is reached not only by a process of exclusion from comparison with the test tube results, but through the direct histological demonstration of a precocious and increasing mobilization of clasmatocytes in the parietal and visceral pleura of treated animals. In other words, sulfanilamide apparently produces a bacteriostasis sufficiently marked to protect the accumulated leucocytes and to allow the natural defense macrophages to accumulate. There is direct evidence that the drug does not in itself stimulate the mobilization of the macrophages. There is no evidence that the cell reaction which finally accounts for disposal of the organisms is other than local. PMID- 19870683 TI - STUDIES ON THE ROLE OF THE SPLEEN IN EXPERIMENTAL POLIOMYELITIS. AB - 1. No difference in susceptibility to infection between splenectomized and non splenectomized monkeys was observed when virus was injected intravenously in large amounts. 2. In a small series of animals, the results suggested that splenectomy decreased resistance to amounts of virus subinfective for non splenectomized monkeys. 3. Splenectomy subsequent to intravenous or intrasplenic inoculation of amounts of virus subinfective for non-splenectomized monkeys did not render the animals susceptible. 4. Following vascular injection, the virus accumulates in the spleen, where it can be detected 24 hours after inoculation, but not at 3 or 5 days. 5. Evidence that splenectomy interferes with antibody formation is presented and discussed. 6. We were unable to demonstrate virus in crude extracts of poliomyelitic spleens but were successful with perfused spleen extracts. This may be due to removal of a neutralizing factor. 7. Attempts to immunize test animals with virus present in poliomyelitic spleens were negative. PMID- 19870684 TI - GLOBIN UTILIZATION BY THE ANEMIC DOG TO FORM NEW HEMOGLOBIN. AB - It has been shown that the standard anemic dog can use sheep, goose or dog hemoglobin when given by vein and return quantitatively its equivalent as new dog hemoglobin within the red cells. Globin at times can be used when given by vein with a quantitative return of new hemoglobin in red cells in these same anemic dogs. Again the administration of globin by vein will inhibit the expected hemoglobin formation; and we believe the toxic effect of the globin is responsible. A digest of globin may be used by the anemic dog to form new hemoglobin. Globin from both horse and dog have been tested and seem to react in identical fashion. The globin radicle of hemoglobin appears to be an important limiting factor in abundant hemoglobin building in this type of anemia due to blood loss. Globin fed by mouth is well utilized to form new hemoglobin and we may record a 30 to 40 per cent utilization or a return of 30 to 40 gm. new hemoglobin from the feeding of 100 gm. globin. This is to be compared with the utilization of liver protein-an average return of 13 gm. new hemoglobin for the feeding of 100 gm. liver protein. PMID- 19870685 TI - PANMYELOPHTHISIS WITH HEMORRHAGIC MANIFESTATIONS IN RATS ON A NUTRITIONAL BASIS. AB - During the 12 months ending May, 1937, 72 rats were observed that manifested typical symptoms of panmyelophthisis. The disease may start as agranulocytosis, thrombocytopenia or pure red cell anemia, leading progressively, often rapidly, to aleukia hemorrhagica with its typical manifestations (epistaxis, melena, hematuria, purpura). Blood examinations revealed correspondingly low white cell, red cell and platelet counts with very pronounced granulocytopenia (0 to 4 per cent). Bone marrow smears and histological findings were consistent with the diagnosis of panmyelophthisis. Suprarenal hemorrhage was a frequent postmortem finding. The pathogenesis of this experimental panmyelophthisis and this hemorrhagic diathesis is confined to special nutritional conditions. These diseases have been observed by us in rats kept on a diet deficient in vitamin B(6), containing cane sugar and supplemented with vitamin B(1) and crystalline natural or synthetic lactoflavin. Lack of vitamin B(6), however, is not a necessary condition, since the disease was encountered in the majority of the animals after the specific deficiency disease which became apparent in rats kept on the B(6) free diet was successfully treated with purified B(6) preparations. Even in the untreated animals kept on the B(6) deficient diet acrodynia was, as a rule, in distinct remission before symptoms of panmyelophthisis and hemorrhagic diathesis became manifest. By means of the addition of Peters' eluate to the basal diet, panmyelophthisis could be prevented and, in animals where it was recognized in an early stage, cured. In view of these facts it is suggested that Peters' eluate contains a specific maturation factor for the primary blood producing tissue, the reticulo-endothelium, a factor which, being different from lactoflavin, vitamin B(6) and probably also from the so called filtrate factor, constitutes another distinct component of the vitamin B(2) group. Bacteriological studies brought forward no conclusive positive evidence for the infectious etiology of the experimental panmyelophthisis in our rats. The possible relation of this new disease in rats to aleukia hemorrhagica and its partial manifestations in man, as well as to the so called Waterhouse-Friderichsen syndrome, is discussed. Administration of amidopyrine, at least under the conditions chosen, failed to provoke panmyelophthisis in rats kept on the same diet as that given to rats in which the disease spontaneously developed. PMID- 19870686 TI - THE RELATION OF ALTERED LOCAL TISSUE REACTIVITY (SHWARTZMAN PHENOMENON) TO INFECTION AND INFLAMMATION. AB - Living B. aertrycke were effective in place of aertrycke filtrate as either the preparatory or the provocative injection in the production of a positive Shwartzman reaction. When living B. aertrycke were injected subcutaneously a more severe inflammation resulted, organization was delayed, and more living organisms survived at the site of inoculation in rabbits that had received 24 hours later an intravenous injection of B. aertrycke filtrate than was the case in similarly infected rabbits that had not received a subsequent injection of bacterial filtrate. When a local state of hypersusceptibility was created by the subcutaneous injection of B. aertrycke filtrate, the subsequent (24 hours) injection of living B. aertrycke led to the development at the site of subcutaneous preparation of a hemorrhagic necrosing inflammation in which the bacteria localized. PMID- 19870687 TI - THE BACTERICIDAL ACTION OF HUMAN SERUM ON HEMOLYTIC STREPTOCOCCI : III. STUDIES CONCERNING: (1) THE SIGNIFICANCE OF HYDROGEN ION CONCENTRATION IN RELATION TO THE STREPTOCOCCIDAL ACTION OF SERUM; (2) THE EFFECT OF REDUCING AGENTS ON THE PHENOMENON. AB - Aerobic Tests. Changes in pH Which Occurred during Incubation.-(a) The pH of sterile specimens of both normal and patients' sera increased, during 24 hours incubation, from 8.0-8.8 up to 9.2-9.6. (b) The pH of patients' sera, inoculated with hemolytic streptococci, progressed in the alkaline direction as did the sterile specimens. (c) The pH of normal sera, inoculated with hemolytic streptococci, pursued a variable course at lower levels than the sterile specimens. The differences in the changes in pH which occurred in streptococcidal sera and in normal controls were dependent upon and secondary to the presence or absence of killing action in the specimens. Aerobic Tests. Effect of Different Levels of Hydrogen Ion Concentration, Adjusted at Beginning of Experiment, but Uncontrolled during Period of Incubation.-(a) The streptococcidal activity of patients' sera was inactivated when the hydrogen ion concentration of the specimens was adjusted to levels ranging from 6.4 to 7.4. The inactivation of highly potent samples of sera required a greater reduction in pH than did specimens of moderate killing activity. (b) Normal sera, adjusted to pH 9.2 or higher, exhibited a relatively slowly acting bactericidal process, which seemed to represent the toxic effect of alkalinity. Aerobic Tests. Effect of Glutathione and Sodium Ascorbate.-The streptococcidal action of patients' sera was markedly impaired by the addition of reducing agents. The inactivation was, in general, comparable to that previously obtained under conditions of anaerobiosis. The results, suggesting that some factor pertaining to biological oxidation-reduction may influence the streptococcidal action of sera, have been discussed. Tests Performed in Closed Jars by Means of Which Relatively Constant pH Was Maintained during the Period of Incubation.-Under the experimental conditions which were employed, the effectiveness of the streptococcidal action of patients' sera was maintained only in alkaline ranges. The most potent specimens of sera were active at lower levels of pH (7.9-8.2) than were other samples (8.4-8.8). All of the observations reported in this article were made with a strain of hemolytic streptococcus of the beta type, which is highly sensitive to the destructive action of serum from acutely ill patients. PMID- 19870688 TI - CHANGES IN BLOOD VESSELS (CAPILLARY FRAGILITY) WITH INFLAMMATION. AB - Suction with a partial vacuum of -70 mm. Hg applied to normal skin of rabbits causes intracutaneous hemorrhage after an average time of 8 minutes. Inflammation produced by various agents, including turpentine, killed streptococci, staphylococci, pneumococci or meningococci, and filtrates from cultures of meningococci or typhoid bacilli, produces a series of changes that are almost uniform. Immediately after injection of the irritant there is greatly increased resistance to the production of hemorrhage by suction so that the time required may be from (1/2) hour to almost 2 hours. This increased resistance to suction applied to the surface of the skin is doubtless caused by contraction of blood vessels following injection of the irritant. The period of increased resistance is soon followed by diminished resistance of the vascular walls so that hemorrhage after 12 to 24 hours following injection occurs within from 1 to 4 minutes of suction. The subsequent course of events varies; resistance of the vascular wall to suction, designated for convenience capillary fragility, may return to normal after from 2 to 9 days (observed with turpentine, streptococcus), or for several days may considerably exceed this level (observed with staphylococcus, pneumococcus), or may remain at a low level for a week or more (observed with tuberculin). With inflammation in a sensitized animal (allergic inflammation) the preliminary period of resistance may be diminished and the appearance of capillary fragility hastened, so that hemorrhage occurs after 2 minutes of suction applied 6 hours after injection, and later it may fall to an even lower level (observed with hemolytic streptococci in sensitized animals). The preparatory injection of toxic substances, such as meningococcus or typhoid filtrate, used in the production of the Shwartzman phenomenon, causes inflammation with injury of small blood vessels indicated by susceptibility to hemorrhage with suction. It is probable that subsequent intravenous injection causes hemorrhage by further injury to these injured blood vessels. PMID- 19870689 TI - AN EPIZOOTIC DISEASE OF FERRETS CAUSED BY A FILTERABLE VIRUS. AB - 1. An epizootic disease of ferrets with a very high case fatality rate is described. 2. By the use of suitable material the natural disease can be transmitted experimentally. 3. The primary causative agent of the disease is a filterable virus. 4. Secondary invasion by bacteria of the respiratory tract of infected animals frequently occurs. The most important secondary invader is hemolytic streptococcus. 5. There seems to be no immunological relationship between the virus of the ferret disease and the viruses of canine distemper and of human influenza. 6. Histologically the disease is characterized by cytoplasmic and intranuclear inclusion bodies in epithelial cells of many organs. 7. These inclusion bodies are indistinguishable from those occurring in canine distemper. PMID- 19870690 TI - THE COMPARATIVE EFFECTS OF NEUTRONS AND X-RAYS ON THE WHOLE BODY. AB - Irradiation of the whole bodies of mice with neutron rays in sufficient quantities, leads to a clinical, bacteriological and anatomical picture similar to that following Roentgen irradiation. The mucosa of the small intestine and the lymphoid and hemapoietic tissues are the most radiosensitive. The mechanism of death after both forms of radiation seems to be a combination of tissue destruction and enterogenous infection, the former predominating in the acute deaths after large doses. Aside from any possible delayed effects from exposure to small doses over a long period of time, concerning which we have no information, these changes after relatively large doses make it imperative that workers in laboratories generating neutrons protect themselves from exposure by screening. For the same amount of ionization measured by a small bakelite-walled thimble chamber, neutrons are more biologically destructive than x-rays. The average daily dose to those working with neutrons should not exceed one-fourth of the tolerance dose accepted for x-rays. Whether daily doses of this magnitude, over a long period of time, will result in damage is not known. Also, if neutrons are tried therapeutically normal tissue must be protected from undue irradiation. PMID- 19870691 TI - STUDIES ON IMMUNITY IN A TYPE OF HUMAN ALLERGY (HAY FEVER): SEROLOGIC RESPONSE OF NON-SENSITIVE INDIVIDUALS TO POLLEN INJECTIONS. AB - Large injections of ragweed pollen extract into normal non-sensitive volunteers did not produce a sensitization to ragweed. Group 1 volunteers in whose skin many reactions were induced by injections of ragweed extract mixed with ragweed sensitive serum failed to show any serological changes. The theory that the immune substance found in the serum of treated ragweed sensitive cases was due to the reaction or to some substance created by it and not to the ragweed per se was not upheld. On the contrary in group 2, volunteers who received larger amounts of ragweed but no sensitive serum, serological changes were induced resembling those previously observed to occur in ragweed sensitive patients after treatment. They were demonstrable by an inhibition of the immediate reaction and by interference with the neutralization of sensitive serum by its antigen. These serological changes are therefore independent of the specific reaction characteristic of this type of allergy. The inhibiting factor was found to be related to the pseudoglobulin fraction of the serum and was shown to be specific. PMID- 19870692 TI - THE CALCIUM CONTENT OF THE KIDNEY AS RELATED TO PARATHYROID FUNCTION. AB - Partial nephrectomy in rats leads to an increase in the calcium content of the residual renal tissue. This increase is correlated with enlargement of the parathyroid glands, the degree depending upon the severity of the kidney lesions. Early removal of the parathyroid glands almost completely prevents this increase in kidney calcium. PMID- 19870693 TI - THE EFFECT OF INCREASED ANTIPNEUMOCOCCAL IMMUNITY ON THE INCEPTION OF EXPERIMENTAL LOBAR PNEUMONIA IN THE DOG. AB - In view of the finding that one or more attacks of pneumococcus lobar pneumonia experimentally induced in dogs failed to protect the animals against subsequent infection, an attempt was made to determine whether or not the dog's antipneumococcal immunity could be enhanced to the degree of complete resistance to the experimental disease. To this end dogs were passively immunized by the intravenous injection of large quantities of both unconcentrated antipneumococcus horse serum and concentrated antibody solution and actively immunized by vaccination with killed and living cultures of pneumococci. None of these procedures were found to result in constant protection against the pulmonary infection. The disease, however, was of brief duration, the lesions of limited extent and usually sterile within 24 hours. A combination of active and passive immunization produced no better results. It was only when immune bodies and leucocytes were implanted with the infecting dose that prevention of infection was secured with any degree of constancy. Even under these conditions the lesion sometimes involved a considerable portion of a lobe. The factors involved in the inception of experimental lobar pneumonia are discussed and the bearing of this study on the prophylactic immunization of human beings against pneumococcus pneumonia is suggested. PMID- 19870694 TI - SPOTTED FEVER : III. THE IDENTIFICATION OF DERMACENTROXENUS RICKETTSI AND ITS DIFFERENTIATION FROM NON-PATHOGENIC RICKETTSIAE IN TICKS. AB - Comparative studies were made of the microorganisms present in D. variabilis ticks, some of which served as a control series while the remainder were exposed to infection with D. rickettsi and thereafter maintained under various conditions. All female ticks contained in their ovaries a coccoid intracellular microorganism. About 50 per cent of all ticks after refeeding contained rickettsia-like microorganisms in variable numbers in nearly all organs. The groups of ticks exposed to infection with the virus of spotted fever, in addition to the above mentioned microorganisms, usually harbored large numbers of D. rickettsi, distinguishable with certainty from the non-pathogenic organisms only by their localization in nuclei of tick cells. No influence upon the size, number, or distribution of either the non-pathogenic rickettsiae or D. rickettsi in ticks was attributable to refeeding, variations of the temperature of incubation, or variations of the length of the period of incubation. We conclude from the results of these studies that the non-pathogenic rickettsiae which occur in D. variabilis ticks have no well defined relationship to D. rickettsi since they differ from the latter organism not only in the absence of virulence and immunizing properties, but also in their distribution in tick tissues and inability to multiply in the nuclei of cells. PMID- 19870695 TI - EXPERIMENTAL LOCAL BLADDER EDEMA CAUSING URINE REFLUX INTO URETER AND KIDNEY. AB - Experimental infiltration of the intravesical ureter of the normal bladder in the living, anesthetized animal with magnesium sulfate or physiological salt solution caused a reflux of urine into the ureter in 6 out of 18 guinea pigs (33 per cent); in 22 out of 27 rabbits (81 per cent), and in 14 out of 17 dogs (82 per cent). The vesical pressure necessary to produce this experimental reflux is low and ranges between 2 and 12 mm. of Hg; hydrostatic pressure of the bladder contents often sufficed to drive urine into the kidney pelvis. After an experimental reflux had occurred, increased vesical pressure often failed to raise the level of the regurgitant column in the ureters of rabbit and dog: these higher pressures had rendered an incompetent valve competent. Control pressures ranging between 8 and 40 mm. of Hg without a preceding infiltration, caused no reflux in the great majority of dogs. The amount of infiltrated fluid necessary to produce reflux varied from 0.2 cc. in the guinea pig to 0.5 to 2 cc. in dog. Spontaneous regurgitation, that is regurgitation without a preceding infiltration, was seen in 4 guinea pigs, 4 rabbits and 2 dogs. Antiperistalsis of the ureters, that is a wave of contraction passing from the bladder to the kidney, was never seen in our animals with experimental reflux. Biopsy of the bladder in rabbit and dog showed edema of the ureterovesical valves after infiltration in most of our animals. Hemorrhages into the submucosa in the neighborhood of the ureteral valves were observed in some. The bladders of 3 rabbits, exhibiting spontaneous reflux without infiltration showed pouting, edematous lips of the ureterovesical orifices. The cause of experimental regurgitation is a non-obstructive edema of the vesical valve; this edema renders the valve flap more rigid and therefore incompetent at relatively low intravesical pressures. Higher intravesical pressures may again render the incompetent valve competent. The experimental results are applied to the human subject because the urinary bladder of dog and of man are quite similar in structure and function. Reasons are presented suggesting that the described type of reflux may cause pyelitis and pyelonephritis. PMID- 19870696 TI - UNILATERAL INHIBITION OF THE RENAL SHWARTZMAN PHENOMENON FOLLOWING INJECTION OF BACTERIAL FILTRATE INTO THE RENAL ARTERY. AB - A positive Shwartzman reaction, as indicated by thrombosis and focal hemorrhage in one or more organs, was elicited in 19 of 34 rabbits in which the preparatory injection of bacterial filtrate was made into the left renal artery and the reacting injection was made in the ear vein 24 hours later. In 24 of the 34 rabbits the kidneys were undisturbed throughout the duration of the experiment except for the intra-arterial injection of the left. In 12 of these 24 a positive Shwartzman reaction was observed in the uninjected right kidneys. In only 1 of the 24 injected left kidneys were there changes that might be construed as representing a positive Shwartzman reaction. The changes in this kidney consisted of glomerular thrombosis, not associated with hemorrhage or necrosis. The positive renal Shwartzman reactions seen in the right kidneys were similar to those reported by Apitz and Gerber as representing the renal changes occurring as part of a generalized Shwartzman reaction. The retention of the bacterial filtrate of the preparatory injection in the left kidney, by obstructing both vein and artery for 15 minutes, did not lessen the refractory state. The removal of the right kidney prior to the experiment, with the subsequent demonstration that circulation through the remaining left kidney was not impaired by the intra arterial injection of filtrate, indicated that the refractory state of the injected kidney was not the result of failure of the reacting dose of filtrate to reach the kidney. In the unilaterally nephrectomized rabbits the development of a positive reaction in other organs indicated that the lack of reaction in the kidney represented a local refractory state. No explanation of the phenomenon was disclosed by these experiments. PMID- 19870697 TI - AN EXPERIMENTAL STUDY OF PROTECTIVE INOCULATION WITH HEAT KILLED TUBERCLE BACILLI. AB - Heat killed tubercle bacilli repeatedly injected into or below the skin of rabbits increase conspicuously their resistance against infection with virulent tubercle bacilli. Protection against tuberculous infection following the administration of heat killed tubercle bacilli to rabbits is only slightly less than that given by BCG. Addition of certain antigens, notably heated horse serum, increases the protection given by heat killed tubercle bacilli so that it is approximately the same as that afforded by BCG. These experiments and tentative observations of persons exposed to tuberculous infection indicate that heat killed tubercle bacilli may be substituted for the living attenuated microorganism in the attempt to increase resistance against tuberculous infection and to influence favorably the delicate balance between asymptomatic or latent infection and progressive manifest disease that is characteristic of human tuberculosis. PMID- 19870698 TI - STUDIES ON HAEMOPHILUS INFLUENZAE : II. A COMPARATIVE STUDY OF THE VIRULENCE OF SMOOTH, ROUGH, AND RESPIRATORY STRAINS OF HAEMOPHILUS INFLUENZAE AS DETERMINED BY INFECTION OF MICE WITH MUCIN SUSPENSIONS OF THE ORGANISM. AB - 1. A comparative study of the mucin virulence of smooth, converted rough, and respiratory strains of H. influenzae was carried out in mice. 2. The smooth strains were found to be significantly more virulent than either the converted rough or respiratory strains. 3. The converted rough and respiratory strains were found to be approximately equal in virulence. 4. A diminution in virulence was observed in those smooth strains which had dissociated spontaneously either partially or completely. PMID- 19870699 TI - PROTHROMBIN DEFICIENCY AND THE BLEEDING TENDENCY IN LIVER INJURY (CHLOROFORM INTOXICATION). AB - The bleeding tendency in acute chloroform intoxication is due to deficiency in both plasma fibrinogen and plasma prothrombin. If the disorder is mild, no bleeding occurs. However, the prothrombin falls to rather low levels, although the fibrinogen falls only moderately. A bleeding tendency may also be produced by giving small repeated doses of chloroform. In such experiments, the hemorrhagic tendency is due to a deficiency in prothrombin alone. The fibrinogen level is unaffected. The relation of the liver injury to the plasma prothrombin level indicates that the liver is concerned in the manufacture of prothrombin. Prothrombin formation appears to be more easily interfered with than does fibrinogen formation. PMID- 19870700 TI - CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES : II. PHYSICOCHEMICAL PROPERTIES. AB - Several physicochemical properties of the active principles of the phenomenon of local skin reactivity to bacterial filtrates have been investigated. Ultrafiltration through Zsigmondy filters of graded porosities has shown that the active substances are retained by membranes finer than 100 to 120 seconds, whereas coarser ones readily permit their passage. The average porosity of this filtration end-point represents a particle size of about 50 to 100 mmicro. When fractionally precipitated with ammonium sulfate, most of the activity of a culture filtrate was concentrated in the two-thirds saturated portion. Isoelectric properties were studied by means of capillary analysis and cataphoresis. At pH 3.0 and below, the substances suspended in the culture filtrates migrated to the cathode; activity in this chamber, however, could not be demonstrated. At pH 4.0 and above, reversal to the anode occurred, as the active materials became negatively charged and readily migrated to this chamber. The isoelectric point, therefore, was considered to be between pH 3.0 and 4.0. Preliminary experiments on adsorption, extraction, and pH stability have been described. PMID- 19870701 TI - THE ROLE OF THE THYROID IN THE REGULATION OF THE BLOOD CHOLESTEROL OF RABBITS. AB - 1. The blood cholesterol of rabbits on a normal diet without added cholesterol is increased only slightly (19 per cent) by thyroidectomy. 2. In rabbits with a hypercholesterolemia due to long continued cholesterol feeding, thyroidectomy causes a marked rise (137 per cent) in the blood cholesterol. This rise is usually maintained. 3. When long continued cholesterol feeding has failed to cause a rise in the blood cholesterol of rabbits, thyroidectomy abolishes this resistance and a hypercholesterolemia is promptly produced. 4. A single injection of thyroxin causes a significant drop in the blood cholesterol of rabbits with hypercholesterolemia. This reaction is not influenced by thyroidectomy. 5. Potassium iodide causes an increase in the blood cholesterol of rabbits with hypercholesterolemia. This reaction is not influenced by thyroidectomy in contrast to the effect of KI in preventing a rise in blood cholesterol when given concurrently from the beginning of cholesterol feeding, an effect which is abolished by thyroidectomy. It is suggested that two different mechanisms are involved. 6. A single injection of insulin produces a fall in the blood cholesterol of rabbits with hypercholesterolemia. If anything, thyroidectomy increases the magnitude of this effect. PMID- 19870702 TI - STUDIES ON INFLAMMATION : XIV. ISOLATION OF THE FACTOR CONCERNED WITH INCREASED CAPILLARY PERMEABILITY IN INJURY. AB - There is present in inflammatory exudates a factor which induces a prompt increase in the permeability of normal capillaries. Its liberation and presence in exudates offers a reasonable explanation for the mechanism of increased permeability of small vessels in injured tissue. A method for the isolation and purification of this permeability factor has been described. In its essential features, this consists of treating the exudate with pyridine followed by acetone. After separation of the protein fractions further purification can be obtained by prolonged extraction with butyl alcohol or by subjecting the acetone supernatant fraction to low temperature (-20 degrees C.). The latter favors spontaneous separation of the active principle. The purified material is a crystalline doubly refractive nitrogenous substance. The factor is evidently not a protein, yet it contains amino and carboxyl groups. It gives a positive test for the presence of an indole nucleus in its structure (Adamkiewicz test). The active material is dialyzable; and it is precipitated by concentrated ammonium sulfate. The present evidence indicates that it is an intermediary breakdown product of protein metabolism, probably belonging to the group of relatively simple polypeptides. Further studies are being conducted in an endeavor to determine its precise chemical structure. PMID- 19870703 TI - CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES : III. APPLICATION OF DIALYSIS TO THE PRODUCTION OF THE ACTIVE PRINCIPLES IN FLUID MEDIA. AB - B. coli, meningococcus, and B. typhosus have been cultivated in a diffused broth medium, prepared by immersing cellophane bags containing saline into nutrient broth. An abundant growth occurred inside the bags, while the outside broth remained sterile. Under these conditions, the production of the active principles of the phenomenon of local skin reactivity to bacterial filtrates has been consistent. When the culture filtrates so obtained were redialyzed against saline, active preparations were obtained which were practically free from non specific ingredients. PMID- 19870704 TI - STUDIES ON INFLAMMATION : XV. CONCERNING THE MECHANISM OF CELL MIGRATION. AB - A crystalline nitrogenous substance recovered from inflammatory exudates induces in cutaneous tissue a rapid migration of polymorphonuclear cells through the endothelial wall of small vessels. For the sake of convenience the tentative name of leukotaxine has been proposed for this active substance which per se is capable of rapidly reproducing the basic sequences of the inflammatory reaction, namely, the initial increased capillary permeability followed by the outward migration of polymorphonuclear leukocytes. Comparison of the effect of various inflammatory irritants (e.g. turpentine or aleuronat) with that of leukotaxine indicates that the migration of cells does not seem to be primarily referable to the initial increase in vascular permeation. Furthermore leukotaxine is definitely chemotactic. It induces an active migration of leukocytes into capillary glass tubes containing this substance. The relation of leukotaxine to the mechanism of cellular migration at the site of inflammation is pointed out. PMID- 19870705 TI - STUDIES ON INFLAMMATION : XVI. ON THE FORMATION OF A CHEMOTACTIC SUBSTANCE BY ENZYMATIC ACTION. AB - Blood serum digested by trypsin yields split products which, when injected into the skin of normal rabbits, rapidly increase the permeability of small cutaneous vessels. This is likewise followed in the affected tissue by prompt local migration of polymorphonuclear leukocytes. The tryptic digest of blood serum can be purified by methods previously described (3). The resulting crystalline substance alters the permeability of the capillary wall and favors local migration of leukocytes in a manner similar to leukotaxine proper. The present observations indicate that leukotaxine, or a substance having at least identical biological properties, appears to have been formed by proteolytic enzymatic action on an otherwise relatively inactive blood serum. This finding serves as additional evidence in support of the view that leukotaxine, recovered from inflammatory exudates, is probably an intermediary product of protein catabolism. PMID- 19870706 TI - STUDIES ON THE RELATIONSHIP OF THE SEX HORMONES TO INFECTION : I. THE EFFECT OF THE ESTROGENIC AND GONADOTROPIC HORMONES ON VACCINIA AND THE SPREADING FACTOR. AB - THE ESSENTIAL FINDINGS OF THESE EXPERIMENTS MAY BE SUMMARIZED AS FOLLOWS: The estrogenic hormone after being given for 1 week slows up the spread of India ink but allows it to reach and exceed a normal spread after 24 hours. After injections of the estrogenic hormone for 3 weeks the spread of India ink is much less than in the control animals. The resistance of the rabbit to vaccinia is increased if the rabbit has been castrated and then given the estrogenic hormone for a period of 3 weeks before being vaccinated. At the present time nothing can be said about the action of the gonadotropic hormone on India ink, as the experiments did not agree. PMID- 19870707 TI - TWO SEROLOGICAL TYPES OF GROUP B HEMOLYTIC STREPTOCOCCI WITH RELATED, BUT NOT IDENTICAL, TYPE-SPECIFIC SUBSTANCES. AB - 1. Among group B hemolytic streptococci one serological type previously described as homogeneous has been shown, instead, to contain two closely related types, distinguishable by reciprocal absorption experiments. These streptococci are designated Types Ia and Ib. 2. Homologous organisms in each case absorb all antibodies from their respective antisera, while organisms of the heterologous related type absorb only the antibody responsible for the cross reactions. Group B streptococci of other types do not absorb the antibodies responsible for the cross reactions between these two related types. The precipitin reaction and passive protection tests in mice were employed in this analysis. 3. The type specific substance of Type Ia is a polysaccharide. Preliminary study indicates that this is also true of Type Ib. While no data are available concerning the chemical relationships of these substances, it seems probable that the two types elaborate polysaccharides, related chemically as well as serologically. PMID- 19870708 TI - THE EFFECT OF HYPERTROPHIC CARTILAGE ON BONE MARROW GROWTH. AB - Intravenous injections of colloidal thorium dioxide were made in rabbits and moderate amounts caused no significant changes in the cellular elements of venous blood. Thorium dioxide was held locally with great tenacity in the cells of the reticulo-endothelial system in the bone marrow and showed little tendency to migrate despite drastic stimuli to the marrow in the form of anemia and plethora. In recently injected rabbits, thorium-laden macrophages abutted each cartilage column in the direction of growth where the cartilage was being removed. In marrow which had formed subsequent to injection the macrophages were thorium free, allowing recognition of the new tissue by x-ray and histological techniques as clear zones. The growth pattern of marrow could be detected in this way. The bone marrow increases in length principally in the region of hypertrophic cartilage at the metaphyses and it is evident that the increase is facilitated by the presence of macrophages whose primary function is the resolution of the wasted hypertrophic cartilage cells. Growth in thickness of bone marrow occurs at its circumference. In contrast to the zonal growth of bone marrow, growth of the reticuloendothelial system in liver and spleen is chiefly interstitial. PMID- 19870709 TI - DEMONSTRATION OF TYPE SPECIFIC PROTEINS IN EXTRACTS OF FUSOBACTERIA. AB - 1. The classification of fusobacteria into types, as suggested by Slanetz and Rettger on the basis of their cultural and biochemical characteristics, was confirmed. The following additional data are presented: the behavior of types I, II, and III in several previously untested carbohydrates; the final pH in 1 per cent glucose broth; the hydrolysis of starch; the failure to decompose sodium hippurate and citrates; the absence of pathogenicity for several types of experimental animals; and the absence of fibrinolysin and of proteolytic enzymes. 2. By the use of a technic described in the text, it was possible to grow the anaerobic fusobacteria in mass cultures. 3. With the methods of Heidelberger and Kendall, immunologically type specific proteins were extracted from fusobacteria types I, II, and III. This observation, which is in a sense an extension of the work of Lancefield on Streptococcus hemolyticus, group A, represents the second instance of a bacterial protein functioning as a determinant of bacterial types. 4. Preliminary data indicate that group specificity depends upon a carbohydrate which is extractable by the methods of Heidelberger and Avery. PMID- 19870710 TI - THE PRESERVATION OF VIRULENT TREPONEMA PALLIDUM AND TREPONEMA PERTENUE IN THE FROZEN STATE; WITH A NOTE ON THE PRESERVATION OF FILTRABLE VIRUSES. AB - 1. A simple method for freezing and maintaining tissue specimens in a mixture of solid carbon dioxide and 95 per cent ethyl alcohol at a temperature approximating -78 degrees C. is described. 2. When frozen and maintained at this temperature Treponema pallidum and Treponema pertenue, upon thawing, exhibited normal morphology and motility and their virulence for rabbits was not appreciably altered after periods of at least 1 year. This applied to a number of different strains of each organism. The infectivity of material in which treponemes were scant was maintained as well as of material in which they were abundant. 3. At temperatures of -10 degrees C. and -20 degrees C. syphilis treponemes did not survive as long as 2 months. Death of the organism occurred not at the time of freezing but during the maintenance period. 4. Treponemes did not commonly survive freezing and desiccation, although one lot of dried material which contained T. pallidum was infective for rabbits 1 day after desiccation. 5. The viruses of human influenza, yellow fever, and spontaneous encephalomyelitis of mice when frozen and maintained at -78 degrees C. showed substantially the same titer after 6 months as before freezing. 6. Certain practical applications of the method are suggested. PMID- 19870711 TI - ANAPHYLACTIC SHOCK BY AZODYES. II. AB - From the experiments presented, it follows that the specific precipitation and the production of anaphylactic shock with certain azodyes, as described previously, is due to these substances themselves and is not dependent upon formation of azoproteins by interaction of the dyes with proteins in the test tube or the animal body. Besides these, some other azodyes which in our tests did not give precipitation with corresponding immune sera were also found, in very small quantities, to induce anaphylactic contraction of the uterus of sensitized guinea pigs. PMID- 19870712 TI - HEMOGLOBIN PRODUCTION IN ANEMIA AS INFLUENCED BY THE BILE FISTULA. AB - The presence of a renal bile fistula with escape of all bile into the urinary tract seriously impairs the capacity of an anemic dog to form new hemoglobin on standard diets. These bile fistula dogs will produce about one-half as much hemoglobin in anemia on standard diets as during earlier control periods without a bile fistula. Iron given by mouth to an anemic bile fistula dog will effect the production of about one-half the amount of new hemoglobin as in control periods. Iron given by vein to an anemic bile fistula dog will approximate the theoretical 100 per cent return of new hemoglobin. Obviously absorption is a very important factor in the utilization of iron by these dogs. The reaction to liver feeding is much like the reaction to iron feeding but we have no proof of inadequate protein digestion and absorption in these bile fistula dogs. In fact the uniform body weight and normal clinical state over periods of years speak for adequate absorption of protein digestion products. Evidence cited above supports our belief that inadequate hemoglobin production (protein formation) noted in these bile fistula dogs may be related to a disturbed liver function. PMID- 19870713 TI - ANAPHYLAXIS IN THE ISOLATED HEART. AB - The isolated hearts of guinea pigs sensitized to horse serum have been shown to react characteristically upon exposure to small amounts of antigen. The cardiac rate is temporarily accelerated and transient alterations in amplitude of contraction are to be observed. Electrocardiographic abnormalities, previously recorded by remote leads during anaphylactic shock in the intact animal, have been recorded by direct leads from the isolated perfused hearts of sensitized animals during this reaction. An additional effect of anaphylaxis in the isolated heart of the guinea pig is reported: a striking reduction in the rate of flow through the coronary vessels. The anaphylactic reaction of the isolated heart of the guinea pig has been compared with the action of histamine upon the same preparation and the effect of atropine upon each has been observed. The implications of certain quantitative differences in the influence of atropine upon these reactions are discussed. PMID- 19870714 TI - QUANTITATIVE STUDIES ON ANTIBODY PURIFICATION : II. THE DISSOCIATION OF ANTIBODY FROM PNEUMOCOCCUS SPECIFIC PRECIPITATES AND SPECIFICALLY AGGLUTINATED PNEUMOCOCCI. AB - 1. The salt dissociation and barium hydroxide-barium chloride methods are extended to the preparation of highly purified antibody solutions from specific precipitates derived from Type III and Type VIII antipneumococcus horse sera and a low grade polyvalent bovine serum. Analytically pure precipitin (agglutinin) was obtained from the last, and Types I, II, and III antibodies were separated. 2. Difficulties connected with the application of the methods to Type I antipneumococcus rabbit sera are described, as is also the purification of antibody from low grade pig and sheep sera. 3. The dissociation of antibody by both methods from Type I pneumococci agglutinated in antisera produced in the horse, rabbit, pig, and sheep, is described and its advantages discussed. 4. Certain theoretical aspects of the work are also discussed. PMID- 19870715 TI - INFLUENCE OF HOST FACTORS ON NEUROINVASIVENESS OF VESICULAR STOMATITIS VIRUS : III. EFFECT OF AGE AND PATHWAY OF INFECTION ON THE CHARACTER AND LOCALIZATION OF LESIONS IN THE CENTRAL NERVOUS SYSTEM. AB - It will be well to restate the main problem at this point and to examine how far the accumulated data can help to elucidate it. The problem is this: Why are old mice generally resistant to all forms of peripheral inoculation of vesicular stomatitis virus when intracerebral injection is equally fatal for mice of all ages? The results of experiments in which the presence of virus was demonstrated by animal passage suggested that the reason can perhaps be found in (a) the different mechanisms of virus progression after intracerebral and peripheral injection, and (b) the development with age of localized barriers capable of halting the spread of virus (1, 2). The present study sought histological evidence for the nature of virus progression and for the changes observed in the older animals. The results clearly demonstrate that after intracerebral injection virus spreads along an open system, the lesions being distributed almost entirely in contiguity with the ventricles and their extensions, while after peripheral inoculations the evidence points to progression of the virus in a closed system of neurons and their processes, at least in the stage preceding neuronal necrosis, the distribution of lesions depending upon the central connections of the primary neurons connected with the inoculated site. Thus, in young mice, nasal instillation of the virus was followed by necrosis of a long chain of neurons, starting with those in the olfactory mucosa and progressing through specific zones of the olfactory pathway, pursuing the same order in which the various regions are known to have their major connections with one another. It is important to note that after nasal instillation the apparent lesions were present where the cell bodies of the neurons are situated, and not along the tracts connecting one group of neurons with another, which accounts for the lack of contiguity between the affected zones and the normal appearing, intervening areas. The assumption that the primary progression of the virus in this case occurs in a closed system is based on the absence of lesions in unrelated areas contiguous to those which are necrotic and to the tracts which connect one affected zone with another. Additional evidence for the assumption that the initial dissemination of peripherally injected virus is in a closed system is found in the decussating optic nerve pathway primarily pursued by the intraocularly injected virus. The progression of the virus along this decussating pathway was indicated in the experimental data obtained on mice 21 days or older, while in younger animals the spread of virus was so rapid and diffuse that the pathways along which it might have occurred remained obscure (2). In the present study, in which 15 day old mice were used, the lesions in the retinal neurons and the constant involvement of only the contralateral superior colliculus left little doubt that the primary spread of the virus, even in these very young animals, must have occurred within the retinal neuron processes (axons) which decussate in the optic chiasm (in the mouse, as in the rat, very few of these go to the homolateral side) and synapse chiefly with the neurons of the contralateral superior colliculus and also, apparently to a lesser extent, with those of the contralateral external geniculate body, where lesions were also demonstrated. Virus spreading in the optic nerve along the perineural subarachnoid space would be found at the base of the brain at the optic chiasm; virus extending along the interstitial spaces in the optic nerve should involve not only the nuclei of both sides of the optic pathway but also non-optic structures, such as the medial geniculate bodies, posterior colliculi, etc., by means of the commissures of von Gudden and of Meynert, whose fibers course through the chiasm. The highly specific localization observed in the present study is best accounted for by progression along the suggested closed pathway. Hurst (10) observed that poliomyelitis virus, after injection into the left sciatic nerve, may, after invading the lumbar cord, be found first in the contralateral motor cortex or thalamus and he suggested that this was evidence of progression along a decussating pathway and in favor of the axonal hypothesis of virus spread. It was not shown, however, that this particular localization was specifically related to the introduction of virus in the left sciatic nerve, or that it could be reversed by inoculating the sciatic nerve of the opposite side. The hypothesis proposed by Hurst, however, finds support in the present instance for (a) the superior colliculi never showed lesions after intracerebral, intranasal, or intramuscular inoculations, and (b) necrosis was produced in either the right or the left superior colliculus, depending on whether the virus was injected into the left or right eyes. The localization of lesions after injection of virus into the muscles of one leg indicated that in the young the invasion occurred along the local peripheral nerves, especially the motor fibers (neurons destroyed in the lumbar cord with those in the spinal ganglia intact), after a primary attack on the muscle itself. The only other lesions found at a late stage were in the reticular substance of the medulla, the olfactory portions of the brain appearing entirely normal. In this respect the mechanism of progression of intramuscularly injected vesicular stomatitis virus differs from that of eastern equine encephalomyelitis and pseudorabies viruses similarly injected into mice of the same age and breed: the former (E.E.E.) invades the central nervous system in the majority of instances, by being eliminated on the nasal mucosa and then along the olfactory pathways (18), while the latter appears to employ chiefly the local sensory fibers, attacking primarily the neurons in the spinal ganglia (unpublished observations). Because the CNS of old mice remain for the most part susceptible to vesicular stomatitis virus (although definite evidence of resistance to necrosis of the neurons was observed), and because after intracerebral injection the virus has been shown to spread in an open (ventricular) system, it is clear why young and old mice are equally susceptible to inoculation by this route. After peripheral inoculation, however, it has been amply demonstrated by experimental and histological methods that the spread of this virus begins and continues, at least until the cells disintegrate, in a closed system within the neurons and their processes and apparently also across the synapses. The halting of the virus somewhere in the anterior rhinencephalon after nasal instillation in resistant mice (1) would appear to be due to an arrest in an insusceptible neuron or an impenetrable synapse somewhere in the chain, and to the failure of the affected neurons to disintegrate (no lesions were found in the CNS of these mice) and thus to liberate the virus into the open system. After intramuscular injection, on the other hand, the virus encounters a different kind of muscle cell in the old mouse, and its inability to invade the nerves may perhaps be bound up with its demonstrated inability to attack and multiply in these changed muscle cells, although the role of a possible alteration in the terminal nerve endings themselves is not yet clear. After intraocular injection, the virus fails to affect visibly the retinal neurons of resistant old mice and the further invasion of the CNS is inhibited. The resistance of old mice to peripheral inoculations of vesicular stomatitis virus thus appears to be the result of (a) changes produced by age not in the whole animal but in certain specific, isolated structures, and (b) the special mode of progression of peripherally injected virus. It may be of interest to point out two phenomena which may perhaps be related to the one investigated in the present study. Tobacco mosaic virus has been found to produce different types of disease in certain plants of different ages; thus a widespread, systemic necrosis leads to the death of young Nicotiana rustica plants, while in old plants it is possible to produce necrotic foci in many parts of the plant by direct inoculation, although generalization does not occur from an isolated focus as it does in young specimens (19). In other words, age apparently does not change the whole plant, but it does transform something which allows the virus to spread easily from one site to another. MacNider (20) has observed that dogs which survive a severe type of hepatic injury from uranium, repair this injury with a special type of atypical, epithelial cell and become resistant not only to secondary intoxications by uranium but also by chloroform; he has also found that this change in epithelial cell type may be acquired as a product of senility, and that when it develops it imparts to the liver a degree of resistance to chloroform comparable to that induced by a process of repair following a severe hepatic injury from uranium nitrate. PMID- 19870716 TI - INFLUENCE OF HOST FACTORS ON NEUROINVASIVENESS OF VESICULAR STOMATITIS VIRUS : IV. VARIATIONS IN NEUROINVASIVENESS IN DIFIERENT SPECIES. AB - Peripheral inoculation of vesicular stomatitis virus is constantly followed by myelitis or encephalitis in young mice, but not in young (or old) guinea pigs. The cause of this variation was elucidated by investigating the fate of the virus after inoculation by a number of different routes. Direct intracerebral injection of minimally infective amounts of virus was found to be equally fatal for young mice and young guinea pigs, indicating that the central nervous system as a whole was as easily injured by the virus in one species as in the other. The events following nasal instillation of the virus varied in young and old guinea pigs. While there appeared to be a transitory multiplication of virus in the nasal mucosa of both young and old, the central nervous system was regularly invaded only in the young. In these, virus was first found only in the anterior rhinencephalon; later it spread to the piriform and hippocampal (olfactory regions) but not to the neopallial portions of the cortex, and the only other area to exhibit virus was the diencephalon (including the pars optica hypothalami), where its further progression was apparently arrested. Absence of central nervous system disease following inoculation into sites supplied by spinal nerves (e.g. sciatic) was found to be due to inability of the virus to invade the nerves. Since direct intrasciatic inoculation frequently led to a fatal ascending myelitis, it was evident that the central nervous system could be invaded along the spinal nerves, and that they did not constitute the main barrier. Furthermore, since multiplication of virus was demonstrated in tissues supplied by the spinal nerves, a process of elimination made it seem possible that the specialized, terminal nerve endings might be the structures which prevent the progression of the virus from the infected tissues to the axons and hence also to the central nervous system. 7 day old guinea pigs (or guinea pigs as a species) were thus found to possess much the same type of barriers to the progression of peripherally inoculated vesicular stomatitis virus as are acquired by mice at a considerably later age. In a discussion of the present data, they have been correlated with known variations in neuroinvasiveness of other viruses and their bearing on the nature of inapparent or subclinical infections of the central nervous system has been considered. PMID- 19870717 TI - SERUM SODIUM, POTASSIUM AND CHLORIDE AFTER SUPRARENALECTOMY IN CATS WITH DIABETES INSIPIDUS. AB - The external symptoms of suprarenal insufficiency in cats with diabetes insipidus are the same as in those animals with only the suprarenals removed, except that the symptoms develop more rapidly in the former. The serum electrolyte changes, however, are different; there is no consistent or marked decrease in the concentration of sodium or chloride following suprarenalectomy in cats with diabetes insipidus, but there is the usual increase in the concentration of potassium. It is suggested that this indicates that changes in sodium are less characteristic of suprarenal insufficiency than are disturbances of potassium metabolism or distribution. A possible inter-relationship between the suprarenal cortex and the posterior lobe of the pituitary as salt-regulating mechanisms is discussed. PMID- 19870718 TI - IRON METABOLISM IN EXPERIMENTAL ANEMIA : "AVAILABILITY OF IRON". AB - In experimental anemia in dogs due to blood loss the term "available iron" as determined by the dipyridyl test has no physiological significance. Iron salts (100 per cent available by dipyridyl) given in optimum dose (560 mg. per 2 weeks) will cause a net production of 50 to 55 gm. hemoglobin above the control base line in anemic dogs. This means that an iron salt which is rated as 100 per cent available by the dipyridyl test is only 35 per cent physiologically available. The term "available iron (dipyridyl)" simmers down to iron not in the form of hematin compounds. The absorption of this "available iron" is conditioned by a great variety of factors, many unknown at this time. Iron is indeed an elusive sprite whose "availability" or comings and goings cannot be determined in dogs by dipyridyl-perhaps only in part by studies of absorption and excretion. Liver contains "available iron (dipyridyl)" but also organic factors influencing hemoglobin regeneration in anemia as liver ash contains only about 50 per cent the potency of the whole liver. One can readily dissociate the iron from other potent factors in various tissues. Fractions of heart, liver, spleen, and kidney may contain very little iron yet cause much hemoglobin regeneration in anemic dogs. No investigator has reported any condition of copper deficiency in man or dog. In fact, in anemias copper is usually above normal concentration in the liver. It is unlikely, therefore, that in experimental anemia in dogs and in the various anemias of man, any significance attaches to the intake of copper. PMID- 19870719 TI - THE HEMOLYTIC EFFECT OF INDOL IN DOGS FED NORMAL DIETS. AB - Indol is mildly hemolytic when fed to dogs taking normal diets. PMID- 19870720 TI - INDUCED SUSCEPTIBILITY OF THE BLOOD TO INDOL. AB - 1. Indol, orally administered, causes anemia when certain deficient diets are fed. 2. The same amount of indol causes no considerable hematologic disturbance when normal diets are fed. 3. The anemia can be cured by supplementing the diet with liver extract, or by substituting a normal diet for the deficient diet. 4. Neither the diet alone nor the administration of indol alone produces marked anemia under the experimental conditions observed. PMID- 19870721 TI - THE INCREASED SUSCEPTIBILITY TO HEMOLYSIS BY INDOL IN DOGS FED DEFICIENT DIETS. AB - 1. Indol is more hemolytic in the presence of a deficiency complex than when a normal diet is fed. 2. The hemolytic effect can be abolished by supplementing the deficient diet with liver extract curative of pernicious anemia in man. 3. The hemolysis affects all hemoglobin-containing cells, including reticulocytes. 4. The repair of the anemia resulting from the administration of indol in the presence of a deficiency represents the cessation of a hemolytic process. 5. An abnormally low rate of production of erythrocytes may well be a factor in the production of the anemia. PMID- 19870722 TI - RESULTS OF THE INTRATRACHEAL INJECTION OF THE BORDET-GENGOU BACILLUS IN THE MONKEY AND RABBIT. AB - Experiments are reported which show that the virulent Bordet-Gengou bacillus can produce a significant lymphocytosis and an interstitial mononuclear pneumonia in both the monkey and the rabbit. Both of these reactions occur apparently as the result of a toxic material formed in vivo from the Bordet-Gengou bacillus and are not dependent on the multiplication of the organism itself. It was also shown that the strictly avirulent form could also cause an interstitial mononuclear pneumonia but no lymphocytosis. This interstitial mononuclear pneumonia was thought to be the result of the foreign substance produced by the organism when it was in this stage. This was substantiated by the fact that this lesion could be produced both by living and dead organisms. PMID- 19870723 TI - CANINE DISTEMPER IN THE RHESUS MONKEY (MACACA MULATTA). AB - Canine distemper has been transmitted to rhesus monkeys by a variety of methods. The disease is strikingly similar if not identical in its features with distemper in dogs. PMID- 19870724 TI - THE SPARING EFFECT OF CANINE DISTEMPER ON POLIOMYELITIS IN MACACA MULATTA. AB - 1. Rhesus monkeys inoculated with canine distemper are relatively or completely immune to experimental poliomyelitis during the first 2 weeks of the distemper. 2. Monkeys convalescent from distemper are not resistant to experimental poliomyelitis. 3. Two monkeys vaccinated with distemper virus responded to poliomyelitis in a modified manner. 4. Distemper antiserum did not influence the course of experimental poliomyelitis in rhesus monkeys. 5. Equine encephalomyelitis and vaccinia encephalitis showed no sparing effect on the course of experimental poliomyelitis. 6. The concurrence of distemper and poliomyelitis in monkeys seems to represent a new immunity mechanism in the virus field. PMID- 19870725 TI - BLOOD PLASMA PROTEINS AS INFLUENCED BY INTRAVENOUS INJECTION OF GUM ACACIA. AB - Lowered plasma protein concentration following single injections of gum acacia in the dog is due in some part to dilution, and in greater part to actual decrease in total circulating protein. The maximum decrease in the total circulating protein does not take place at the same time as the maximum decrease in concentration. Fluctuations in fibrinogen concentration are marked, and are not necessarily proportional to changes in plasma protein concentration. Plasma protein concentration returns to normal limits within 10 to 21 days after the injection, at which time total circulating protein and plasma volume are lower than normal. Loss of protein cannot be accounted for by increase in urinary nitrogen. It is possible to maintain dogs at low levels of plasma protein concentration for several weeks by repeated injections of gum acacia solution. Anatomical changes following such a procedure in a normal dog are most conspicuous in the liver (Fig. A). These observations further implicate the liver as a source of plasma protein. Two mechanisms for the diminution of plasma protein following gum injection are suggested. One of these is based on the possibility that the liver cells being engorged with gum acacia are not able to produce the necessary amount of plasma protein to supply the normal demand. The other possibility is that with the injection of the gum, since there is obviously a greatly increased amount of colloid in the blood, the more readily removable colloid, i.e. plasma protein, is taken out of the blood stream, in an attempt to return plasma volume and colloid osmotic pressure to the normal limits. It is probable that both of these mechanisms are involved. Injection of gum acacia is suggested as a technique for further study of disturbed liver function. It must be obvious that clinical use of gum acacia for intravenous injection is not without danger. PMID- 19870726 TI - IMMUNOLOGICAL STUDIES OF A HEAT-STABLE SUBSTANCE ISOLATED FROM TISSUES INFECTED WITH VACCINE VIRUS. AB - We have shown that it is possible to obtain from extracts of vaccine virus infected tissues a substance or substances, apparently protein, which are serologically active, and which are specifically related to vaccinal infection. The present investigation is concerned with a study of their immunological reactions. Their intraperitoneal injection in rabbits is followed by the appearance in the serum of these animals of antibodies directed specifically against them. The precipitating capacities of this serum are entirely removed after addition of appropriate quantities of heated vaccine virus extract, indicating that antibodies against only the heat-stable antigens have been produced. Further evidence of the specificity of the antibodies is gained from the reverse experiment, that is, absorption of a virus extract with the serum. We have shown that under suitable conditions the serum will remove S antigen specifically leaving the labile substances in solution. This would apparently indicate that they are serologically distinct although both are vaccinal products. Serum of animals injected with the S substance and containing antibodies against it in high titer is apparently capable of neutralizing minute amounts of active virus. The animals providing the serum are, however, without demonstrable resistance to vaccinia. The significance of the neutralizing activity of the serum is debatable because it is of a greatly different order of magnitude from that which follows infection with vaccinia. PMID- 19870727 TI - TOXEMIA OF PREGNANCY IN THE RABBIT : II. ETIOLOGICAL CONSIDERATIONS WITH ESPECIAL REFERENCE TO HEREDITARY FACTORS. AB - No definite conclusions relative to the etiology of toxemia of pregnancy in the rabbit can be drawn from the evidence obtained to date, but certain findings are suggestive and will be investigated further in future studies. These findings suggest that the disorder in the rabbit is a generic variation of eclampsia in man. The incidence, clinical manifestations and pathological lesions indicate that the disorder is of hypophyseal origin and that the association with pregnancy is due to altered activity of that gland in the terminal stages of gestation. Hereditary factors related to race and certain constitutional variations were associated with increased susceptibility, but their expression was apparently dependent upon environmental conditions. The association of widespread reproductive disturbances with the outbreak of toxemia suggests a causal relation, and it is assumed that the endocrine imbalance was a primary factor in their genesis and was induced by changed environmental conditions. The general response of the population was manifest in functional disturbances which were of minor severity in normal groups and were expressed as toxemia in inherently susceptible animals. PMID- 19870728 TI - THE EFFECT OF FORMALDEHYDE ON PNEUMOCOCCI. AB - When used in low concentration, formaldehyde increases the rate of autolytic disintegration of pneumococci whereas in large concentrations it completely inhibits autolysis and preserves both the morphological and staining characteristics of the cells. Pneumococci treated with large concentrations of formaldehyde, then washed free of the antiseptic and resuspended in physiological solutions, rapidly undergo a change which renders them Gram-negative and smaller. The lysis is only partial, however, and is not accompanied by an actual disintegration of the cell. It is caused by the autolytic enzyme of the cell which remains inactive in the presence of an excess of formaldehyde but recovers its activity when the cells are resuspended in a neutral medium after removal of the antiseptic. If the autolytic enzyme is irreversibly inactivated by heating, or maintained inactive in acid or alkaline reaction, the formolized cells retain their staining characteristics and morphological integrity. Formolized pneumococci which have become Gram-negative owing to the action of their autolytic enzyme, fail to elicit the type specific carbohydrate antibodies in rabbits. Formolized pneumococci in which the autolytic enzyme has been destroyed or maintained inactive, and which have retained their Gram-positive character, function as a very effective type specific antigen in the rabbit. These observations emphasize once more the close relation between the Gram-positive structure of pneumococci and the capsular polysaccharide antigen of the cell. They can be used as a basis for the preparation of suspensions of formolized pneumococci which are stable and very effective as type specific antigens. PMID- 19870729 TI - THE CARCINOGENIC EFFECT OF A PAPILLOMA VIRUS ON THE TARRED SKIN OF RABBITS : I. DESCRIPTION OF THE PHENOMENON. AB - The Shope papilloma virus elicits carcinomas forthwith, as well as papillomas in great variety, when it is distributed by way of the blood stream to the tarred epidermis of domestic rabbits. The phenomenon will be analyzed in succeeding papers with the aid of additional instances. PMID- 19870730 TI - A GROWTH INHIBITORY SUBSTANCE FOR THE INFLUENZA GROUP OF ORGANISMS IN THE BLOOD OF VARIOUS ANIMAL SPECIES : THE USE OF THE BLOOD OF VARIOUS ANIMALS AS A SELECTIVE MEDIUM FOR THE DETECTION OF HEMOLYTIC STREPTOCOCCI IN THROAT CULTURES. AB - 1. 5 per cent sheep blood agar is a selective medium for beta hemolytic streptococci in throat cultures since sheep blood inhibits the growth of bacillus X (H. hemolyticus) and B. parainfluenzae hemolyticus. The growth of H. influenzae is also inhibited by sheep blood. 2. The inhibitory action of sheep blood resides in the erythrocytes and is thermolabile. Disruption of the cell by laking has no effect upon the inhibitor. 3. The bloods of animals closely related to the sheep, such as the goat and the cow, have a similar inhibitory action on the growth of hemolytic and non-hemolytic members of the influenza group, while human blood contains a similar but less powerful inhibitor for these organisms. 4. Members of the influenza group grow well on unheated rodent blood: rabbit, guinea pig, and rat. 5. These organisms also grow fairly well on unheated horse blood. PMID- 19870731 TI - EXPERIMENTAL SYPHILIS OF ORIENTAL ORIGIN: CLINICAL REACTION IN THE RABBIT. AB - Two oriental strains of T. pallidum of Chinese origin were compared with two well known occidental strains, the Nichols and the Zinsser-Hopkins, on the basis of the clinical reaction to infection in the rabbit. Four experiments were carried out, two each in Peiping and New York. Animals from American and Chinese sources were represented in each experiment. The results obtained showed that the reaction to both Chinese strains was generally comparable to that of the American strains. But with both Chinese strains, lesions of the eyes were more frequent, the time relations of certain phases of the reaction were shortened, and there was a higher incidence of complete recovery (latency) within the observation period. In view of the well known variability of the syphilitic reaction, however, it was not felt that these qualitative differences in clinical response could be ascribed to inherent or biologically fixed properties of the strains. PMID- 19870732 TI - HEPATIC DYSFUNCTION IN DOGS FED DIETS CAUSATIVE OF BLACK TONGUE. AB - 1. The feeding to dogs of a diet lacking the vitamin B(2) (G) complex results in a lowered capacity of the liver to excrete intravenously injected bilirubin. 2. Normal function can be partly restored by supplementing the diet with liver extract. 3. Normal function can be completely restored by feeding a normal diet. PMID- 19870733 TI - THE ABSENCE FROM THE URINE OF PERNICIOUS ANEMIA PATIENTS OF A MOSQUITO GROWTH FACTOR PRESENT IN NORMAL URINE. AB - Extracts prepared from the urine of normal persons or patients with aplastic anemia or leukemia contain a substance, possibly flavine or a flavine compound, which under suitable conditions of test enhances the growth of larvae of the mosquito, Aedes aegypti. This substance is lacking, or is present in much smaller amount, in extracts from the urine of pernicious anemia patients showing symptoms of the disease. Extracts from the urine of the same patients after adequate treatment contain as much of the substance as normal urine extracts. PMID- 19870734 TI - THE METABOLISM OF LUNG TISSUE IN EXPERIMENTAL LOBAR PNEUMOCOCCUS PNEUMONIA IN THE DOG. AB - The metabolism of infected and uninfected lung tissues was determined at various stages of experimental lobar pneumococcus pneumonia in dogs. Analyses of tissues and analyses of the blood entering and leaving the lungs indicate a fairly normal aerobic metabolism of the tissue throughout the course of the infection. PMID- 19870735 TI - SOME EFFECTS OF FORMALDEHYDE ON HORSE ANTIPNEUMOCOCCUS SERUM AND DIPHTHERIA ANTITOXIN, AND THEIR SIGNIFICANCE FOR THE THEORY OF ANTIGEN-ANTIBODY AGGREGATION. AB - Small amounts of formaldehyde inhibited the precipitating activity of horse diphtheria antitoxin with toxin and of horse antipneumococcus serum with the homologous capsular carbohydrate. Approximately 1 part of commercial formaldehyde to 1000 parts of serum, acting for 24 hours, inhibited the flocculating activity completely. In both cases, the combining affinity of the treated antibody for the corresponding antigen was not demonstrably affected, as determined both by in vitro experiments and by animal protection. More intensive treatment of the antipneumococcus serum caused an apparent loss of its bacterial agglutinating activity, but on centrifugation the organisms cohered: combination had occurred, and only the spontaneous aggregation was prevented. These effects are the same as those previously described for diazo compounds, and have been qualitatively reproduced with acetaldehyde, benzaldehyde and butyraldehyde. The quantitative relationships suggest that only a few groups in the antibody molecule need be modified by formaldehyde in order to prevent aggregation; and it is probable that these are some of the free NH(2) groups of the antibody protein. In marked contrast, the combining affinity of both antipneumococcus antibody and diphtheria antitoxin for the corresponding antigens was only slightly affected by amounts of formaldehyde which sufficed to block the free NH(2) groups rapidly and almost completely. Similarly, this amount of treatment did not affect the reactivity of these two antisera acting as antigen with a rabbit antiserum versus horse serum. The integrity of the NH(2) groups is apparently not essential for the activity of these sera acting either as antigen or as antibody; and the slow disappearance of their activity in concentrated HCOH is apparently to be ascribed to some secondary reaction other than the simple addition of HCOH to free NH(2) groups. The present experiments do not support the theory that antigen-antibody aggregates are lattice-like structures built up from elementary antigen-antibody compounds because of residual specific combining groups. The aggregating activity of both antipneumococcus serum and diphtheria antitoxin was completely inhibited by procedures which did not demonstrably affect their combining power with antigen. This suggests that the aggregation of antigen-antibody compounds is a secondary, non-specific reaction. It is perhaps significant that the amount of formaldehyde which just sufficed to prevent aggregation also caused a marked increase in the solubility of the pneumococcus antibody, which could then no longer be precipitated at serum pH by dilution with water or by dialysis. This strongly suggests that the loss of precipitating activity is actually due to the increased solubility of the antibody and supports the hypothesis that the primary cause of specific antigen-antibody aggregation is the relative insolubility of the bound antibody. PMID- 19870736 TI - THE DEGREE OF COMPENSATORY RENAL HYPERTROPHY FOLLOWING UNILATERAL NEPHRECTOMY : II. THE INFLUENCE OF THE PROTEIN INTAKE. AB - Compensatory hypertrophy of the kidney in albino rats is increased by an increase in the protein intake. The effect is greater in old rats than young rats. Successive increases in the protein intake are followed by a reduction in the increase in the degree of compensatory renal hypertrophy. PMID- 19870737 TI - OBSERVATIONS ON THE PATHOLOGICAL CHANGES FOLLOWING EXPERIMENTAL HYPERTENSION PRODUCED BY CONSTRICTION OF THE RENAL ARTERY. AB - The clinical histories and pathological findings of six animals dying within a few days following bilateral constriction of the renal arteries have been presented. No explanation for the rise in blood pressure was found. The clinical histories and pathological findings of twelve animals with a sustained hypertension have been considered together with the detailed account of one of these in which a marked degree of arterial disease was found. It has been suggested from the study of this group that, though no cause for the initiation of the hypertension was found, the induced arterial disease might account for its maintenance. PMID- 19870738 TI - EVIDENCE OF ACTIVE IMMUNITY TO EXPERIMENTAL POLIOMYELITIS OBTAINED BY THE INTRANASAL ROUTE IN MACACUS RHESUS. AB - The experiments reported above indicate that the intranasal instillations of pituitrin S and adrephine, alter susceptibility in the rhesus monkey. One-half to two-thirds of the treated animals resisted intranasal infection, and, moreover, most of the resistant animals which had received combined treatment and virus developed active immunity, as indicated by the presence of neutralizing substance in their serums and by their ability to resist intracerebral infection. We have, it appears, not alone modified in some fashion the usual reaction of this animal to intranasal infection, but we have also successfully vaccinated these animals by the nasal route, so that the response in animals more nearly approaches what we believe to be the response in human beings. We have no knowledge of the mechanism by means of which pituitrin S and adrephine produce this apparent alteration in susceptibility, but since the outcome of continued exposure to virus in most of the animals treated with these substances results in immunity, we believe that this offers a more hopeful approach toward the control of the disease. PMID- 19870739 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : IV. QUANTITATIVE DATA ON PNEUMOCOCCUS R (DAWSON S)- ANTI-R (S) SYSTEMS. AB - 1. The quantitative, absolute method of agglutinin estimation is extended to the reaction between Types I and II pneumococcus R (S) suspensions prepared in various ways and antisera from rabbits injected with these cells. 2. Quantitative estimations of the amount of antibody to pneumococcus C substance are also given. 3. The significance of the data is discussed. PMID- 19870740 TI - THE COURSE OF VIRUS-INDUCED RABBIT PAPILLOMAS AS DETERMINED BY VIRUS, CELLS, AND HOST. AB - An experimental analysis of the factors responsible for the observed differences in the course of virus-induced papillomas of the rabbit has shown that some are referable to the virus, others to the cells, and yet others to host influences. The interplay of these factors affords enlightening illustration of the nature of the cell-virus relationship in virus-induced tumors. Retrogression of the rabbit papillomas appears to be consequent on a generalized resistance of host origin, elicited by and directed against the proliferating, virus-infected cells. PMID- 19870741 TI - A STUDY OF THE MACROPHAGE REACTION IN THE PULMONARY LESIONS OF DOGS WITH EXPERIMENTAL PNEUMOCOCCUS LOBAR PNEUMONIA. AB - A study has been made of the occurrence of the macrophage reaction in the pulmonary lesions of dogs sacrificed during the course of experimentally induced pneumococcus lobar pneumonia or dying as a result of the infection. This characteristic transformation of the fixed tissue cells of the lung was found as a constant accompaniment of recovery. It was also present in varying degrees in the great majority of fatal instances provided the animal lived more than 40 hours. In general the longer the animal survived, the more pronounced the macrophage reaction observed in the lung lesions at autopsy. The numbers of pneumococci in the lesions diminished progressively with the evolution of the cellular change which terminated in resolution of the pneumonic exudate. Some dogs surviving for 4 days or more showed practically complete clearing of the pulmonary lesions but succumbed with an overwhelming bacteremia or empyema or both. On the other hand, several animals dying with a sterile blood, exhibited lesions characterized by little or no macrophage response and the presence of many pneumococci. These findings suggest that recovery from experimental lobar pneumonia in the dog depends on a dual mechanism consisting of a generalized process which prevents or controls invasion of the blood stream and a local one by which the lesion is finally freed from the invading microorganisms. The nature of these two processes is discussed. PMID- 19870742 TI - LOCAL RECOVERY IN EXPERIMENTAL PNEUMOCOCCUS LOBAR PNEUMONIA IN THE DOG. AB - An investigation has been made of the process of local recovery occurring in the pulmonary lesions of dogs with experimental pneumococcus lobar pneumonia. Six animals showing simultaneous healing and spread of the pathological process in different parts of the lungs were sacrificed during the active stage of the disease for bacteriological and histological study. It was found that with few exceptions the clearing (resolving) lesions as revealed by x-ray during life were sterile on culture while the young, metastatic processes yielded an abundant growth of pneumococci. The resolving areas which represented the older lesions were characterized by the presence of a well developed macrophage reaction, whereas the early lesions consisted of alternating areas of edema and polymorphonuclear infiltration and contained usually many pneumococci both free and in the cells. The only pneumococci found in the areas of macrophage mobilization were intracellular forms, for the most part in the process of digestion. In several instances these striking differences in the cellular picture and the numbers and distribution of pneumococci were observed in different parts of a single lobe lesion. Tests on the blood serum failed to reveal any evidence of acquired antipneumococcal humoral immunity. The significance of these findings in relation to the mechanism of recovery is discussed. PMID- 19870743 TI - JAPANESE B ENCEPHALITIS VIRUS: ITS DIFFERENTIATION FROM ST. LOUIS ENCEPHALITIS VIRUS AND RELATIONSHIP TO LOUPING ILL VIRUS. AB - 1. Japanese B encephalitis virus, obtained from Japanese investigators, has proved virulent for mice and monkeys, confirming the reports from Japan. It has also been found virulent for monkeys when instilled intranasally and for sheep when introduced intracerebrally or intranasally. 2. Japanese B encephalitis virus has been differentiated from St. Louis virus and found similar to louping ill virus according to its reactions in animal species. Serologically, however, it is distinct. 3. Japanese B encephalitis and its related group of primary virus encephalitides of man have been discussed with regard to their differentiation and mode of spread. PMID- 19870744 TI - THE INFLUENCE OF INFLAMMATION ON THE ABSORPTION OF SUBSTANCES OF VARIED DIFFUSIBILITY. AB - 1. Inflammation retards the absorption of horse serum globulin and crystalline egg albumin from the peritoneal cavity and subcutaneous tissue, but retardation of the absorption of crystalline egg albumin is less than that of globulin, which is less diffusible. 2. Inflammation retards the absorption of the specific polysaccharide of pneumococcus Type I from the peritoneal cavity; inflammation may accelerate, but does not hinder, the absorption of glucose from the peritoneal cavity. 3. Inflammation retards the spread of trypan blue in the skin, but accelerates absorption from the skin of the more diffusible dye, brom phenol blue. 4. Phenol red is excreted in the urine with equal rapidity after injection into normal and into inflamed subcutaneous tissue or into normal and into inflamed peritoneal cavities. Direct extractions of phenol red from inflamed subcutaneous sites indicate that inflammation accelerates the absorption of the dye from these areas. 5. Inflammation retards the absorption of the indiffusible proteins, carbohydrates and dyes; it tends to accelerate the absorption of the diffusible carbohydrates and dyes. PMID- 19870745 TI - A STABLE HEMOLYSIN-LEUCOCIDIN AND ITS CRYSTAL-LINE DERIVATIVE ISOLATED FROM BETA HEMOLYTIC STREPTOCOCCI. AB - 1. A chemically pure hemolysin-leucocidin has been isolated from beta hemolytic streptococci, but not from other species of bacteria studied. 2. It does not give rise to antibodies, but precipitates immune sera against hemolytic streptococci, and is therefore a hapten. 3. A highly purified sample of S. H. up to a dilution of 1:128,000 hemolyzes red blood cells. Its hemolytic activity is not specifically neutralized by antiserum versus beta hemolytic streptococci. It is leucocidic in that it inhibits the reduction of methylene blue by leucocytes. 4. The hemolysin-leucocidin is stable to oxygen, to heat and to moderate changes in hydrogen ion concentration. Its chemical structure has been determined in part. Its molecular weight is 2260. 5. A crystalline derivative has been isolated as the sodium salt from the hemolysin-leucocidin. As the free acid it has a molecular weight of 720. Its hemolytic and leucocidic activity parallels that of S. H., although it is not serologically active. It possesses a high degree of toxicity for mice and rabbits. PMID- 19870746 TI - HYDROGEN ION CONCENTRATION IN EXUDATES OF PNEUMOCOCCUS INFECTION. AB - The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH determinations on exudates from living animals. For indirect evidence of an increase in hydrogen ion concentration within the lesions, the difference in sugar content between exudate and blood from animals with pneumococcus infection has been measured. With sanguinous exudate from the consolidated lungs of dogs with experimental pneumococcus pneumonia, the findings were not always consistent, but usually there was either direct or indirect evidence of increased hydrogen ion concentration. The physicochemical changes in exudate from animals treated with artificial pneumothorax showed no important differences from those in other specimens. In concurrence with Lord's (1, 2) observation of increased acidity in pneumonia exudate obtained at autopsy, sugar concentrations, which are low in the blood, were markedly reduced in exudates from animals which had died of the infection. Serous exudates from dermal pneumococcus infection in rabbits uniformly showed definite acidity by both direct and indirect methods of estimation. The hydrogen ion concentrations in exudate from dermal pneumococcus infection in rabbits varied between pH 6.87 and 6.66 but were not always proportional to the difference in sugar concentrations between the exudate and blood. While these hydrogen ion concentrations are similar to those attained in the pneumonic exudate from dogs, they are of lesser magnitude than those which Takahashi (3) has described in the pus of secondary empyema due to the pneumococcus. PMID- 19870747 TI - THE EFFECTS OF ACIDITY UPON THE GROWTH OF PNEUMOCOCCUS IN CULTURE MEDIA CONTAINING PROTEINS. AB - In the presence of animal fluids or their protein constituents, Type I Pneumococcus survived and multiplied at acid hydrogen ion concentrations which in the plain broth were bactericidal for these organisms. Minimal numbers of these cells readily produced pneumococcus growth in serum broth when adjusted at hydrogen ion concentration as great as pH 5.5 with hydrochloric, or to pH 6.5 with acetic acid. Growth of the pneumococci could be demonstrated in serum broth adjusted to pH 5.0 with hydrochloric, or to pH 5.5 with acetic acid although at these hydrogen ion concentrations, large amounts of inoculum were necessary. Similar results were obtained with broth to which certain animal proteins were added and in serum broth which was previously heated by autoclave at 20 pounds pressure for 20 minutes. Pneumococcus growth proceeded at a more rapid rate in serum dextrose broth at pH 6.5 than in dextrose broth alone at the optimal hydrogen ion concentration of pH 7.8. At pH 6.0 large numbers of pneumococci failed to produce the same amount of growth in serum dextrose broth as at pH 6.5 or in dextrose broth alone at pH 7.8. It is of interest that in serum dextrose broth cultures, the stationary and decline phases of pneumococcus growth were prolonged and cell death delayed in comparison with cultures in dextrose broth alone. PMID- 19870748 TI - BLOOD PLASMA PROTEIN REGENERATION AS INFLUENCED BY FASTING, INFECTION, AND DIET FACTORS : VARIABLE RESERVE STORES OF PLASMA PROTEIN BUILDING MATERIAL IN THE DOG. AB - When blood plasma proteins are depleted by bleeding, with return of the washed red cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal low protein diet. These dogs are clinically normal with normal appetite, no anemia and normal nitrogen metabolism. These dogs become test subjects by which various factors relating to plasma protein production may be tested. The normal dog (10 to 13 kg.) has a substantial reserve store of plasma protein building material (10 to 60+ gm.) which requires 2 to 6 weeks plasmapheresis for its complete removal. After this period the dog will produce uniform amounts of plasma protein each week on a fixed basal diet. Dogs previously depleted by plasmapheresis and then permitted to return to normal during a long rest period of many weeks, may show much higher reserve stores of protein building material in subsequent periods of plasma depletion (see Table 1). Under uniform conditions of low protein diet intake when plasmapheresis is discontinued for 2 weeks the plasma protein building material is stored quantitatively in the body and can subsequently be recovered (Table 4) in the next 2 to 3 weeks of plasmapheresis. Given complete depletion of plasma protein building reserve stores the dog can produce very little (2+/- gm. per week) plasma protein on a protein-free diet. This may be related to the wear and tear of body protein and conservation of these split products. Abscesses produced in a depleted dog during a fast may cause some excess production of plasma protein which is probably related to products of tissue destruction conserved for protein anabolism. Gelatin alone added to the basal diet causes very little plasma protein production but when supplemented by tryptophane gives a large protein output, while tryptophane alone is inert. PMID- 19870749 TI - UTERINE ADENOMATA IN THE RABBIT : I. CLINICAL HISTORY, PATHOLOGY AND PRELIMINARY TRANSPLANTATION EXPERIMENTS. AB - 83 cases of an adenomatous tumor of the uterine mucosa have been observed in a colony of rabbits during the past 4 years The results of a clinical and pathological study of the tumor, together with a description of transplantation experiments are included in the present report. The clinical histories of tumor bearing animals are similar in all cases. Discovery of the tumor is preceded by a long period of reproductive disturbance, and its subsequent course is one of slow, continuous growth which has terminated in death with metastasis in all animals held under observation for longer than 1 year. Microscopically, the tumor shows an atypical alveolar structure, and its characteristics closely resemble those of an adenocarcinoma of the uterine fundus in women. Pathological changes similar to those observed in mice after treatment with estrogenic substances occur in the thyroid, suprarenal, pituitary and mammary glands. Intraocular transplantation of the tumor has been successful, and at the present time the growth has been carried through 6 generations by serial transfer. PMID- 19870750 TI - ON CROSS REACTIONS OF IMMUNE SERA TO AZOPROTEINS : II. ANTIGENS WITH AZOCOMPONENTS CONTAINING TWO DETERMINANT GROUPS. AB - Azoproteins have been prepared with azocomponents possessing two serologically active groups. On immunization with such antigens immune sera were obtained containing two separate, unrelated antibodies, each specific for one of the two groups and separable by absorption. In other cases one of the two structures was dominant, in that antibodies were formed only towards this and not towards the other grouping. The specificity of the antibodies was in general found to be influenced to some extent by the presence of a second group in the antigen. The relevancy of these observations for antibodies directed against natural antigens has been noted. PMID- 19870751 TI - STATISTICAL STUDIES OF THE NATURE OF THE INFECTIOUS UNIT OF VACCINE VIRUS. AB - A method has been described by which it is possible to estimate the number of particles of vaccine virus which are required to cause infection in the rabbit skin. The method consists essentially in performing a series of intradermal inoculations in rabbits of suitably diluted virus suspensions. The percentage of inoculations at each dilution giving rise to lesions is observed, and the data are subjected to appropriate statistical analysis. Several strains of vaccine virus, differing in their characteristics, have been studied with the following results. Infection with the New York City Board of Health virus appears to follow the injection of a single particle of virus. The same is true for the strain derived from it but cultured in a chick embryo-Tyrode solution medium for a prolonged period. This strain, as has been noted, has largely lost its ability to cause extensive necrosis in the rabbit skin, and causes generalized infection only exceptionally. From the results here reported, it appears that other factors are responsible for the altered character of the lesion than the ability of the virus to establish a foothold in the animal organism. In this respect the cultured appears to be the equal of the original passage virus. Similarly the Noguchi strain of virus is apparently capable of infecting, if a single virus particle is properly introduced. PMID- 19870752 TI - SEROLOGICAL EVIDENCE FOR THE OCCURRENCE OF INFECTION WITH HUMAN INFLUENZA VIRUS IN SWINE. AB - Antibodies capable of neutralizing human influenza virus were present in the sera of old swine on two New Jersey institution farms, but absent from the sera of young swine on the same farms. The old animals had lived through the winter of 1936-37 in which outbreaks of upper respiratory tract disease were prevalent among the human inmates of the two institutions, while the young swine studied were born long after these outbreaks. It is believed that the swine whose sera neutralized human influenza virus had undergone an unrecognized human influenza virus infection acquired from man. The possible bearing of these observations upon the theory that swine influenza was originally of human origin is discussed. PMID- 19870753 TI - THE EXCRETION OF CYANOL, AZOFUCHSIN I AND WATER BY THE KIDNEYS OF RABBITS. AB - 1. The excretion of water has been studied in a large number of experiments on rabbits. After the ingestion of 100 cc. of water, the day before the experiment and as part of the experiment, the average diuresis amounted to 0.6 cc. per minute during a half hour period. The highest individual rate was 1.5 cc. per minute. 2. The excretion of cyanol and of azofuchsin I has also been studied. It has been shown that the cyanol excretion curve closely parallels the inulin excretion curve of Kaplan and Smith. Evidence is presented that cyanol is disposed of entirely or mainly by filtration. 3. The excretion of azofuchsin I is not only very different from that of cyanol or inulin, but almost identical with that of phenol red. Evidence is presented that at low plasma concentration azofuchsin is, in the main, secreted. PMID- 19870754 TI - ACUTE EXPERIMENTAL GLOMERULAR NEPHRITIS IN RABBITS: A CORRELATION OF MORPHOLOGICAL AND FUNCTIONAL CHANGES. AB - It has been shown in this paper that structural and functional changes in acute glomerular nephritis in rabbits produced by nephrotoxins by the method of Masugi are the same as those found in human glomerular nephritis. The morbid anatomy is characterized by glomerular cell proliferation, and in some cases by deposition of fibrin and crescent formation of the glomeruli and by fatty changes of the tubules. The functional changes are: oliguria, proteinuria, hematuria, cylindruria, edema, rise in blood urea, and according to Masugi (1933, 1934) and Smadel (1936, 1937), rise in blood pressure, lipuria, and fall in urea clearance and plasma proteins. As we are unaware of any discrepancies between the experimentally induced disease and human nephritis, the conclusion follows that the two so closely resemble each other that they appear to be identical. As to the pathogenesis, it has been shown that the disease begins with a period of latency. This is characterizied anatomically by hyperemia of the glomeruli; and functionally, in at least a number of cases, by an increased diuresis. It follows, therefore, that the theory of Volhard, according to which glomerular nephritis is caused by arteriolar spasms, can no longer be maintained. It has further been demonstrated that proliferation of glomerular cells is the typical lesion, and that deposition of fibrin and crescent formation occur only in certain cases, and in these only in a widely varying number of glomeruli. As crescents are found as early as the proliferation itself, it follows that they should not be regarded as pathognomonic of the subacute phase, but that they represent a complication which probably aggravates the disease. As to correlation of morphological and functional changes, it has been demonstrated that oliguria, marked proteinuria and diminished excretion of cyanol appear at the time when the glomerular changes are at their peak. Evidence has been presented that the oliguria and the decrease in cyanol excretion in acute glomerular nephritis are chiefly the result of the glomerular damage. It has further been demonstrated that the excretion of azofuchsin was unchanged, except for a diminution in the rabbit which at autopsy showed a marked fatty change of the tubules. We regard these observations as evidence, that, in acute glomerular nephritis in rabbits, glomeruli and tubules may function independently of each other. PMID- 19870755 TI - THE EFFECT OF A TISSUE ENZYME UPON PNEUMOCOCCI. AB - Polymorphonuclear leucocytes contain an enzyme which destroys the basophilic character of beat-killed pneumococci (R and S variants) and inactivates the type specific polysaccharide antigen of encapsulated cells. The same enzyme, however, fails to cause a disintegration of the bacterial cells, or to decompose the capsular polysaccharide itself. The enzyme has been extracted from a number of animal tissues; it appears identical with a purified enzyme extracted from pancreatin and which decomposes yeast nucleic acid. These facts are considered with regard to the failure of rabbits to produce the type specific carbohydrate antibodies when immunized with heat-killed encapsulated pneumococci by the intradermal route. PMID- 19870756 TI - IMMUNIZATION OF EXPERIMENTAL ANIMALS WITH A SOLUBLE ANTIGEN EXTRACTED FROM PNEUMOCOCCI. AB - Pneumococci killed by acetic acid at pH 4.2, then allowed to become Gram-negative at pH 7.0, under conditions such that no cellular disintegration takes place, release in solution small amounts of a substance which is precipitable by acetic acid, and soluble at neutral reaction. This soluble fraction injected into rabbits by the intravenous route causes the production of antibodies which afford definite protection to mice infected with virulent pneumococci of Types I, II, and III. Other types were not tried. White mice immunized with this soluble antigen exhibit some active immunity to virulent pneumococci, but the results have been very irregular so far. Soluble fractions, similar in properties and with apparently the same immunizing action, have been obtained from both virulent (S) and avirulent (R) cells of pneumococci. PMID- 19870757 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : VII. THE PRODUCTION OF THE MALIGNANT PHASE OF HYPERTENSION. AB - The production of the acute malignant phase of experimental hypertension has been accomplished in seventeen dogs. The method used to produce this type of hypertension was the same as for the benign type (4), namely, constriction of the main renal arteries, or the equivalent, constriction of the aorta above the origin of both main renal arteries, but the constriction was especially severe. The malignant phase in the animals was characterized by hypertension, terminal renal insufficiency and the development of petechiae and larger hemorrhages in many internal organs, especially the alimentary tract. These were due to dissecting hemorrhage through, or rupture of, the wall of severely hyalinized or necrotic arterioles, or rupture of capillaries. Hyalinization and necrosis of arterioles were more severe and more widespread in animals that had a period of benign hypertension before the onset of renal insufficiency. In animals with a previous long period of benign hypertension, thickening of the media also occurred in arterioles, with or without hyalinized intima. Elevation of blood pressure (mechanical factor) and renal insufficiency (humoral factor) are at least two of the necessary conditions for the development of the necrotic arterioles and hemorrhages. Necrotic arterioles and hemorrhages have not yet been observed in animals that have had very high blood pressure for years without renal insufficiency, nor in animals with azotemia, due to removal of both kidneys, but without hypertension. Hyalinized retinal arterioles have been observed in dogs with persistent hypertension and with moderate or no disturbance of renal function. That ischemia is not the cause of the necrosis of the arterioles is shown by their absence from the ischemic kidneys of the dogs and their widespread presence in other organs that were not ischemic. These experiments show that the necrotic arterioles and hemorrhages are secondary to and not the primary cause of the malignant phase of hypertension. PMID- 19870758 TI - BILE AND BLOOD PLASMA CHOLESTEROL AS INFLUENCED BY BLOOD DESTRUCTION IN NORMAL AND BILE FISTULA DOGS. AB - Destruction of large amounts of red cells in normal and bile fistula dogs by means of acetyl phenylhydrazine causes no significant alterations of the blood plasma but there is some decrease in the bile cholesterol. During Bartonella canis infection the splenectomized bile fistula dog periodically breaks down large quantities of red cells with slight decrease in the plasma cholesterol and marked decrease in the bile cholesterol. In the periods of blood regeneration following such acute anemias there are no significant alterations in the values for plasma or bile cholesterol. PMID- 19870759 TI - WHITE CELL MORPHOLOGY IN RABBITS WITH INDUCED PERITONEAL EXUDATES. AB - 1. When peritoneal exudates are produced in the rabbit by the injection of a large volume of isotonic saline, nearly all the cells in the exudate are polymorphonuclear leucocytes, and the number contained in a single exudate may exceed the entire number originally present in the circulation. 2. The migration of polymorphonuclear leucocytes from the blood stream into the exudate is followed by a stimulation of the marrow, so that the blood stream is filled with young cells, many of which also pass into the exudate. This marrow stimulation, with the resultant shift of the polynuclear count to the left, is probably produced by the absorption of breakdown products of the cells which first appear in the exudate. 3. If exudates are produced repeatedly at intervals of from 4 to 10 days, the marrow responds by throwing younger and younger cells into the circulation, so that the blood stream becomes full of very young polymorphonuclear leucocytes of class I, or even metamyelocytes. If 4 or 5 exudates are produced in rapid succession, the polymorphonuclear leucocytes in the circulation are all replaced by metamyelocytes and myelocytes. PMID- 19870760 TI - STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : IX. THE COOPERATIVE ACTION OF HEMOPHILUS GALLINARUM AND THE COCCOBACILLIFORM BODIES IN THE CORYZA OF RAPID ONSET AND LONG DURATION. AB - Coccobacilliform bodies were regularly demonstrable, in addition to H. gallinarum, in exudate from birds infected with a passage strain of the coryza of rapid onset and long duration (type III). Both agents were present throughout the entire course of the disease. The characteristics of type III coryza were reproduced by injecting a mixture of the two agents. The behavior of each component was altered by the association, indicative of a synergistic relation. Evidence that the coccobacilliform bodies might occasionally develop in birds infected with H. gallinarum following transfer by indirect contact was also obtained. The combined action of the two infective agents adequately accounts for the etiology of this particular strain of type III coryza. PMID- 19870761 TI - THE AGGLUTINATION OF PLASMODIUM KNOWLESI BY IMMUNE SERUM. AB - A specific agglutination of Plasmodium knowlesi detectable both by macroscopic and by microscopic methods is described. Agglutinins for Plasmodium knowlesi appear in the sera of monkeys between 15 and 45 days after the onset of the infection and become progressively stronger as the malarial infection gradually subsides. Agglutinins persist in the sera of chronically infected animals for a year or longer. The sera of animals which have been repeatedly superinfected agglutinate parasites at dilutions as high as 1:1,000. Sera from normal monkeys, from monkeys acutely ill with malaria, and from monkeys chronically infected with a different species of malarial parasite (Plasmodium inui) do not agglutinate Plasmodium knowlesi. Immune serum agglutinates mature intracellular or extracellular parasites but does not agglutinate unparasitized cells or cells containing immature parasites. The relation of these observations to the mechanism of active and passive immunity in monkey malaria is discussed. PMID- 19870762 TI - THE COMPLEMENT FIXATION REACTION IN MONKEY MALARIA. AB - 1. A specific complement fixation reaction test for Plasmodium knowlesi malaria in rhesus monkeys is reported with details involved in the preparation of the antigen and procedures employed in setting up the test. 2. It was found that specific complement-fixing antibodies appeared early in the course of the experimental disease and persisted during the course of the chronic infection. 3. The first appearance of complement-fixing antibodies was generally followed by a temporary fall in titer. During the first 2 months of infection there was no apparent relationship between the number of circulating parasites and the changes in complement fixation titer. 4. During the stage of chronic infection there was a fall in the titer of complement-fixing antibodies preceding each parasitic relapse, and after the relapse had terminated, there was an elevation of the complement-fixing titer. PMID- 19870763 TI - THE FATE OF VACCINIA VIRUS ON CULTIVATION IN VITRO WITH KUPFFER CELLS (RETICULO ENDOTHELIAL CELLS). AB - The pathogenic activity of vaccinia virus is in large part suppressed when it is mixed with living Kupffer cells or clasmatocytes in the test-tube and injected intradermally. Vaccinia increases in quantity when introduced into cultures of Kupffer cells in vitro, and survives in immediate association with these elements. No antiviral principle is elaborated by them under such conditions. PMID- 19870764 TI - BLEEDING TENDENCY AND PROTHROMBIN DEFICIENCY IN BILIARY FISTULA DOGS: EFFECT OF FEEDING BILE AND VITAMIN K. AB - In biliary fistula dogs the plasma prothrombin falls eventually to low levels and bleeding commonly occurs. Faulty absorption of vitamin K from the intestine in these animals is an important causative factor. Feeding bile permits absorption of the traces of this vitamin normally present in mixed diets, and as a result a slow rise in prothrombin level is observed. If a standard diet is supplemented with large amounts of vitamin K concentrate the prothrombin rise is rapid, provided bile or bile salt is supplied to aid in the absorption. Variations in the rate of prothrombin depletion in biliary fistula dogs kept on constant diet indicate the existence of additional factors which require further study. Our experience indicates that vitamin A and vitamin D supplements do not correct the prothrombin deficiency in biliary fistula animals. PMID- 19870765 TI - A MENINGO-ENCEPHALITIS IN CHICKS PRODUCED BY THE INTRACEREBRAL INJECTION OF FOWL POX VIRUS. AB - 1. Intracerebral inoculation of fowl pox virus in young chicks produces a disease characterized by the development of drowsiness and somnolence 4 to 5 days after inoculation. This is followed by spastic paralysis and convulsions on the 6th and 7th day. The majority of inoculated chicks die on the 7th or 8th day. 2. The pathological lesions are found chiefly in the meninges, perivascular structures, the choroid plexus, paranasal sinuses, mastoid cells, the bone marrow of the cranial bones, and the orbital tissues. No affinity for nervous tissue per se develops. 3. In this environment the virus has a high virulence for the choroidal plexus epithelium and acquires the capacity for infecting cells of mesodermal origin. All infected cells of whatever origin undergo a similar structural change. Fowl pox inclusions can be demonstrated within them and they become spherical in shape and detached from each other. 4. The virus has been carried through 14 successive intracerebral passages. The symptoms and lesions in the chicks inoculated with the 14th passage showed no marked difference from those of the first passage. No enhancement of the changes brought about in the virus by the intracerebral environment seems to take place upon repeated passage. PMID- 19870766 TI - A STUDY OF THE BEHAVIOR OF FOWL POX VIRUS MODIFIED BY INTRACEREBRAL PASSAGE. AB - 1. Intracerebral transfer in chicks of fowl pox virus produces marked changes in its behavior when studied in the chorio-allantoic membrane of chick embryos and in the skin of baby chicks. 2. A great and persistent increase in virulence for epithelial cells, characterized by rapid necrosis instead of proliferation and hyperplasia, is acquired by the virus propagated intracerebrally. 3. An affinity for cells of mesodermal origin including endothelial cells of blood vessels, and an increase in affinity for entodermal cells is acquired by the virus propagated intracerebrally. 4. The intracerebral virus causes a uniform morphological change in all types of cells, in that the infected cells rapidly become spherical in shape, detached, and desquamated followed by necrosis. 5. One intracerebral passage is sufficient to produce this change in the virus. PMID- 19870767 TI - A METHOD FOR DETERMINING THE DIFFERENTIAL SEDIMENTATION OF PROTEINS IN THE HIGH SPEED CONCENTRATION CENTRIFUGE. AB - A method is presented for determining the relative degree of sedimentation of proteins and other small particles, either in pure form or in a mixture, utilizing the concentration centrifuge of Bauer and Pickels. Chemical analysis or biological assay of material obtained at different fluid levels by means of a special sampling device is used to measure the degree of sedimentation. The results are reproducible within 10 per cent and, under the conditions of the experiments cited, are characteristic for the proteins thus far investigated. PMID- 19870768 TI - THE DEMONSTRATION OF LESIONS AND VIRUS IN THE LUNGS OF MICE RECEIVING LARGE INTRA PERITONEAL INOCULATIONS OF EPIDEMIC INFLUENZA VIRUS. AB - Following the intraperitoneal inoculation of mice with large doses of epidemic influenza virus (50,000 to 1 million intranasal M.L.D.) it can be recovered from the lungs in high concentration, and pulmonary lesions of moderate extent may be observed. The virus reaches its highest titer in the lungs 48 to 72 hours after intraperitoneal injection and may persist for 10 days. Virus may be recovered from the blood in the first 24 hours, but is readily detected in the omentum and peritoneum for 5 to 6 days. Mice which as a result of the intraperitoneal injection of virus show a high concentration of virus in the lungs do not die but become solidly immune to intranasal infection. Moreover, as early as 24 to 48 hours after intraperitoneal inoculation of large amounts of virus the animals may exhibit resistance to infection with fatal doses of virus given intranasally. Influenza virus given intravenously to mice is rapidly removed from the blood but persists in the lungs and induces pulmonary lesions. Virus can also be recovered from the liver for several days. With subcutaneous inoculation of influenza virus, however, the virus does not reach the blood or lungs in detectable amounts although the regional lymph nodes may yield considerable quantities of the agent. A brief consideration is presented of the mechanisms of infection and resistance which may be involved. PMID- 19870769 TI - HORMONE STUDIES WITH THE ULTRACENTRIFUGE : I. AN IMPROVED AIR-DRIVEN VACUUM ULTRACENTRIFUGE SUITABLE FOR CONCENTRATION WORK IN BIOLOGICAL EXPERIMENTS. AB - 1. An ultracentrifuge is described in which the rotor is driven by a compressed air turbine, and is spun in an evacuated chamber to minimize friction and heating. The rotating parts are supported by a cushion of air in an air bearing. 2. The centrifuge rotor holds 10 test tubes inclined at 45 degrees to the axis, and has a capacity of 55 cc. It is operated at a maximum speed of 51,000 R.P.M., which develops at the top of the fluid column in the test tubes a centrifugal field of over 100,000 times gravity, and at the bottom of the fluid column a field of over 200,000 times gravity. 3. By means of a reverse turbine, the rotor can be brought to a stop from full speed in a relatively short time. 4. A precession damping device is described, which effectively damps the precession and wobbling of the rotor that usually occurs at certain speeds in machines of this type. 5. A relatively long section of shaft is used between the centrifuge rotor and lower bearings. This prevents vibrations from being appreciably transmitted through the shaft to the lower bearings and driving mechanism, and results in a negligible wear on the bearings. 6. The driving mechanism is designed so that the positions of its parts are adjustable, and so that the driving mechanism may be dismantled without disturbing these adjustments. PMID- 19870770 TI - IMMUNITY OF MICE FOLLOWING SUBCUTANEOUS VACCINATION WITH ST. LOUIS ENCEPHALITIS VIRUS. AB - 1. Susceptible mice injected subcutaneously or intraperitoneally with 15,000 intracerebral lethal doses of St. Louis encephalitis virus develop an immunity in 4 to 7 days to 1,000 to 1,000,000 lethal doses given either intracerebrally or intranasally. 2. This immunity persists 4 to 6 weeks, then decreases gradually and disappears after 8 to 12 weeks. 3. More than 1,000 intracerebral doses of virus given as a vaccine do not materially increase the amount or duration of the immunity; less than 1,000 doses give little or no immunity. 4. Test virus injected intracerebrally into immunized mice induces few lesions and is rapidly destroyed; instilled intranasally, it rarely reaches the olfactory lobes or brain. 5. While immunity is maximum, circulating neutralizing antibodies are not detectable. Moreover, the immunity is not affected by endothelial cell blockade or by splenectomy. 6. A few moments after the immunizing virus is given, it can be recovered from the blood in relatively high concentration. After 24 hours, the blood no longer contains demonstrable virus nor do any organs thus far tested except the spleen. The brain and cord remain entirely normal. The spleen, however, becomes enlarged and harbors virus for as long as 30 days. PMID- 19870771 TI - CUTANEOUS INFECTIVITY IN EXPERIMENTAL POLIOMYELITIS : INCREASED SUSCEPTIBILITY AFTER NEUROSURGICAL PROCEDURES. AB - 1. Bilateral olfactory neurectomy did not prevent experimental poliomyelitis on intravenous or intracutaneous inoculation. 2. Various operative procedures increased the susceptibility of monkeys to infection with experimental poliomyelitis. PMID- 19870772 TI - EFFECT OF REPEATED SUPERINFECTION UPON THE POTENCY OF IMMUNE SERUM OF MONKEYS HARBORING CHRONIC INFECTIONS OF PLASMODIUM KNOWLESI. AB - Protection tests have been utilized to determine the effect of superinfection upon the potency of immune serum of monkeys with chronic Plasmodium knowlesi infections. The results of these tests showed that: 1. In 2 groups of monkeys with comparable P. knowlesi infections the immune serum of 8 monkeys which had been superinfected on 7 separate occasions over a period of 2 months was much more potent than the immune serum of a group of 7 monkeys which were allowed to continue their chronic course of infection without superinfection. 2. After a series of 9 more intense superinfections the serum from the same 2 groups of monkeys contained no demonstrable protective antibodies. 3. The serum from 8 of the 10 monkeys in the original 2 groups showed a relatively high concentration of protective antibodies following a month's rest and a single superinfection. 4. The results of the experiments indicate that it is possible to increase the potency of immune serum by superinfection, but it is also possible to obtain a decrease in the protective property of the serum by too severe superinfections. PMID- 19870773 TI - THE QUANTITATIVE RELATIONSHIP BETWEEN IMMUNE SERUM AND INFECTIVE DOSE OF PARASITES AS DEMONSTRATED BY THE PROTECTION TEST IN MONKEY MALARIA. AB - The minimal infective dose of Plasmodium knowlesi for rhesus monkeys was found in this study to be between 1 and 10 parasites when injected intraperitoneally. As the dose of parasites is increased, the length of time prior to the appearance of circulating parasites is decreased. However, the severity of the infection once it is established is independent of the initial dose of parasites. In passive protection experiments a quantitative relationship was demonstrated between the number of parasites in the inoculum and the effective amount of immune serum given at the time of infection and in equal doses daily for 9 days thereafter. The smaller the inoculum, the less the quantity of immune serum required to prevent the death of the animal. When relatively large amounts of immune sera and small numbers of parasites were used in the protection experiment, infection was prevented. PMID- 19870774 TI - FATE OF NASALLY INSTILLED POLIOMYELITIS VIRUS IN NORMAL AND CONVALESCENT MONKEYS WITH SPECIAL REFERENCE TO THE PROBLEM OF HOST TO HOST TRANSMISSION. AB - With a method of intranasal instillation of poliomyelitis virus that brings about infection of all M. rhesus monkeys subjected to it, a study was undertaken of the fate of nasally instilled virus in normal and convalescent, immune animals. Control experiments revealed that nasal mucosa of normal monkeys contained no observable antiviral factors and that when five or ten minimal cerebral infective doses were added to the mucosa, virus could be detected by the employed procedure. In the olfactory bulbs even a single infective dose could be recovered, since suspensions of both bulbs could be transferred to the brain of a monkey without any loss of material. After nasal instillation of virus in normal monkeys, it disappeared quickly (4 hours or less) and could be recovered neither from the excised nasal mucosa nor from the olfactory bulbs during the first 48 hours. At 72 hours, just before or coincident with the first rise of temperature, virus was found in very small amounts in the nasal mucosa and for the first time also in the olfactory bulbs. At 96 hours, at least 3 days before the appearance of nervous signs, and later, while virus continued to be present in considerable amounts in the olfactory bulbs (and presumably elsewhere in the central nervous system), none was detected in the nasal mucosa. In convalescent, immune animals receiving the same strain of virus intranasally which caused the original infection, none could be recovered from the nasal mucosa or central nervous system at 4 hours, 1, 2, 3, 4, 5, and 7 days. The bearing of these observations on the problem of host to host transmission of poliomyelitis virus is discussed. PMID- 19870775 TI - VITAL STAINING OF THE CONNECTIVE TISSUES. AB - Trypan blue injected intravenously is bound almost at once by the intercellular connective tissue elements all over the body,-by collagen, reticulin, and elastic fibers. This union of dye and tissue elements is the factor responsible for the early macroscopic blue color and is antecedent to cellular colloidopexic action. Different examples of connective tissue differ among themselves in their ability to hold the dye. Diffuse staining of elastic fibers noted by previous observers is merely a special case of the general affinity of connective tissue for the dye. The evidence suggests that the histiocytes are cells specialized to segregate noxae that become diffusely bound to the intercellular connective tissue matrix. PMID- 19870776 TI - QUANTITATIVE STUDIES OF BRUCELLA PRECIPITIN SYSTEMS : I. PRECIPITATION OF HOMOLOGOUS ANTISERA BY BRUCELLA ENDOANTIGENS. AB - It has been shown that the precipitation by the endoantigens of the three species of brucella of their homologous antibodies may be described by equations developed from the law of mass action. The endoantigens may be used for the accurate calibration of brucella antisera. The nitrogen-containing constituent of the endoantigens does not always seem to be intimately connected with the ability to precipitate the specific antibodies. PMID- 19870777 TI - QUANTITATIVE STUDIES OF BRUCELLA PRECIPITIN SYSTEMS : II. THE PRECIPITATION OF HETEROLOGOUS ANTISERA BY BRUCELLA ENDOANTIGENS. AB - Quantitative cross precipitation studies with goat antisera show the three endoantigens of the brucella to be serologically distinguishable. Although the endoantigens of Br. abortus and Br. suis are very similar, they do not react identically, permitting the serological distinction of the two organisms. These differences in cross precipitation may be used to identify an organism of the brucella group or to determine the organism responsible for a brucella antiserum. PMID- 19870778 TI - IMMUNIZATION OF GUINEA PIGS AGAINST LYMPHOCYTIC CHORIOMENINGITIS WITH FORMOLIZED TISSUE VACCINES. AB - Guinea pigs can be immunized against lymphocytic choriomeningitis by 2 or 3 injections with formolized vaccines prepared from a variety of infected guinea pig tissues. Vaccines prepared from the consolidated areas of diseased lungs gave the best results. The immunity produced was partial in the majority of the cases, in that the vaccinated animals as a rule showed fever after the test of immunity and virus was present in the circulation during the febrile period. Vaccines prepared from infected mouse tissue had no, or very little, immunizing power for guinea pigs, even when prior to formolization they contained at least as much virus as guinea pig tissue vaccines. This failure to immunize appears to be due to the interference by heterologous antigens, since the immunity induced by homologous vaccines was often inhibited when formolized normal mouse tissue suspensions treated in the same manner as the guinea pig tissue vaccines were added to the latter before inoculation. The inhibitory effect of the heterologous tissue was less marked when it was not mixed with the vaccine but injected simultaneously on the opposite side of the body. The immunizing power of homologous vaccines did not parallel their virus content prior to formolization. A high degree of immunity, characterized by protective antibodies in the serum, was produced in some guinea pigs by prolonged treatment with large doses of homologous vaccine, while sera of guinea pigs vaccinated in the ordinary manner contained no detectable neutralizing antibodies. It is possible, therefore, that the immunity produced by inactive virus differs only quantitatively from that induced by an infection. PMID- 19870779 TI - AN UNIDENTIFIED VIRUS PRODUCING ACUTE MENINGITIS AND PNEUMONITIS IN EXPERIMENTAL ANIMALS. AB - An infectious agent is described which belongs apparently to the class of filtrable viruses, but which, on the basis of the evidence at hand, is not to be identified with any virus previously described. The virus has multiple tropisms and is pathogenic for mice, ferrets, and monkeys of both M. rhesus and M. cynomolgos species. Intranasal infection of mice and ferrets causes extensive pneumonic lesions of fatal severity. Intracerebral inoculation of the virus produces in monkeys a lymphocytic choriomeningitis from which the animal recovers, while in mice a rapidly fatal choriomeningitis is produced. Fatal paralysis occurs in a moderate proportion of mice which receive the virus by intraperitoneal or subcutaneous routes, while the remainder become immune to the intracerebral test but not to the intranasal test. Subcutaneous inoculation of mice, monkeys, ferrets, rabbits, and guinea pigs causes local granulomatous induration of the skin with enlargement of the regional lymph nodes. The virus was repeatedly recovered in 1936 from ferrets inoculated with throat washings of patients suffering from an epidemic disease clinically indistinguishable from epidemic influenza. It is impossible, however, to conclude whether the virus is of ferret or human origin. Although possessing many features in common with the virus of lymphocytic choriomeningitis and the virus of lymphogranuloma inguinale, cross immunity tests have failed to yield any evidence that the new agent is immunologically related to either of the aforementioned viruses. For purposes of identification the name virus of acute meningopneumonitis is suggested. PMID- 19870780 TI - THE EFFECT OF CORTICOSTERONE AND RELATED COMPOUNDS ON THE RENAL EXCRETION OF ELECTROLYTES. AB - The sodium and chloride retaining effect of suprarenal cortical extracts and of crystalline compounds derived from the suprarenal cortex parallels their effectiveness in maintaining suprarenalectomized dogs. All of the active compounds thus far studied produce a potassium diuresis when injected into normal dogs. The injection of a synthetic compound, desoxy-corticosterone acetate, produced in normal dogs a very marked sodium and chloride retention and a potassium diuresis. In a suprarenalectomized dog desoxy-corticosterone acetate was substituted successfully for suprarenal cortical extract. PMID- 19870781 TI - INTRAPERITONEAL AND INTRACEREBRAL ROUTES IN SERUM PROTECTION TESTS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : I. A COMPARISON OF THE TWO ROUTES IN PROTECTION TESTS. AB - Young (12 to 15 day old) mice are approximately as susceptible to the virus of equine encephalomyelitis, Eastern or Western strain, when it is given intraperitoneally as are adult mice when the virus is injected intracerebrally. With this susceptibility by the intraperitoneal route as a basis, the injection of immune serum-virus mixtures intraperitoneally was found to result in protection in dilutions which give rise to infection after intracerebral inoculation. The difference of protective power by the two indicated routes was shown not to depend on the amount of inoculum nor on the age of the intracerebrally injected mice. Incubation at 37 degrees C. for 2(1/2) hours neither increases nor diminishes the protective action of immune serum when the intraperitoneal method is employed. The phenomenon of selective protection in different tissues is elicited by the sera of hyperimmunized mice, guinea pigs, and rabbits and by sera derived from horses infected with the disease in nature or exposed to it by contact. Of four horses recovered from the malady, all showed antibody in their sera; of others exposed by contact, four of nine animals revealed antiviral bodies, when the intraperitoneal technique was employed. These tests on horse sera have pointed to the potential value of this procedure for epidemiological studies. Finally, the reaction itself has significance through its bearing on the mechanism of immunity. PMID- 19870782 TI - PRODUCTION OF EXPERIMENTAL OSTEOMYELITIS IN RABBITS BY INTRAVENOUS INJECTION OF STAPHYLOCOCCUS AUREUS. AB - 1. The conditions under which a certain strain of staphylococcus (OH 172) causes in rabbits the development of bone inflammation have been described. 2. The virulence of the strain for rabbits was markedly raised by passage through this animal species, and especially after the culture had been recovered from a bone abscess. 3. The results indicate that it is possible to produce consistently inflammation of the bones of rabbits by the mere intravenous injection of a suitable strain of staphylococcus, without resorting to any elaborate operative technique designed to localize the organisms in the bones. It appears also that the inflammatory process so produced bears a close resemblance to staphylococcal osteomyelitis as occurring in human beings. PMID- 19870783 TI - SENSORY NEURON DEGENERATION IN VITAMIN DEFICIENCY : DEGENERATION OF THE POSTERIOR COLUMNS OF THE SPINAL CORD, PERIPHERAL NERVES, AND DORSAL ROOT GANGLION CELLS IN YOUNG PIGS FED A DIET CONTAINING THIAMIN (B(1)) AND RIBOFLAVIN BUT OTHERWISE DEFICIENT IN VITAMIN B COMPLEX. AB - Young pigs were given an artificial diet presumably adequate in all respects. As they developed, the quantity of yeast was gradually reduced while thiamin (vitamin B(1)) and riboflavin were given in its place. The rate of growth decreased, the general condition of the animals became impaired, and marked ataxia without motor weakness developed. Histologically, severe degeneration of the posterior columns of the spinal cord, the dorsal root ganglion cells, and the peripheral nerves was found. PMID- 19870784 TI - THE ISOLATION OF THE BLOOD GROUP A SPECIFIC SUBSTANCE FROM COMMERCIAL PEPTONE. AB - The isolation of the blood group A specific substance from commercial peptone has been described. The chemical and serological properties of the material from that source have been defined. PMID- 19870785 TI - FACTORS INFLUENCING THE PERSISTENCE OF CHORIOMENINGITIS VIRUS IN THE BLOOD OF MICE AFTER CLINICAL RECOVERY. AB - Mice infected in utero continued to carry choriomeningitis virus in the blood more regularly and in greater amount than suckling mice infected by contact. This result may be due to the difference in tissue maturity at the time of infection: the more immature the tissues are when infected, the longer the virus appears to persist in them after maturation. A similar result was obtained with mice of different ages infected either by contact or by intranasal instillation of virus, in that the carrier state lasted longer in the younger animals. This cannot be attributed entirely to the difference in age, however, since young mice as a rule showed more severe symptoms than mature animals. It is possible, therefore, that the difference in the severity of the disease accounted in part for that in the duration of the infection. In mature mice infected experimentally as well as in some of the suckling mice infected by contact the severity of the disease was the determining factor, the infection persisting longest in those animals that showed the most severe reaction. The character of the virus used also appeared to influence the persistence of the virus in the blood. A strain of virus isolated in 1935 from an infected stock mouse and modified by intracerebral passage in mice (5) disappeared from the circulation more rapidly than the stock strain maintained by natural passage in the infected mouse stock. The guinea pig passage strain, however, which was obtained from the same mouse as the mouse passage virus but passed through guinea pigs by pad inoculation, persisted in the blood more frequently than the stock strain. Carrier mice without exception had a high degree of immunity to intracerebral injection with virus, while other animals once infected but no longer carrying detectable amounts of virus in the blood often showed an incomplete immunity that manifested itself in an accelerated, non fatal reaction, presumably of an allergic nature. This observation does not prove, however, that the immunity always is an "infection immunity," since a high degree of resistance not associated with detectable amounts of virus in the blood and brain was produced by repeated injections with the mouse passage strain. Since the blood and the tissues of old carriers often contain large amounts of virus, it is very unlikely that their immunity is due to protective antibodies circulating in the blood or fixed in the tissue spaces. It rather appears that the susceptible cells of such animals are infected and that cells occupied by actively multiplying virus cannot be reinfected. The mechanism of this infection immunity as well as the immunity apparently not associated with infection requires further study. PMID- 19870786 TI - THE PASSAGE OF RABBIT VIRULENT TYPE III PNEUMOCOCCI FROM THE RESPIRATORY TRACT OF RABBITS INTO THE LYMPHATICS AND BLOOD. AB - 1. Rabbit virulent Type III pneumococci when instilled into the nose or trachea were recovered from the lymphatics draining the area involved in the lymph collected during a subsequent 4 hour period. Their detection rarely failed, and not infrequently was possible at the end of the 1st hour. 2. The organisms practically invariably appeared first in the lymphatics and subsequently in a few cases were recovered from the blood during the 4 hour test period. 3. The intravenous administration of antiserum 2(1/2) to 3 hours before the instillation of organisms decreased the number of animals whose lymph or blood became positive and the total length of time in which organisms were recovered in lymph from the efferent lymphatics during the test period. PMID- 19870787 TI - RELATION BETWEEN DEGREE OF IMMUNITY OF MICE FOLLOWING VACCINATION WITH ST. LOUIS ENCEPHALITIS VIRUS AND THE TITRE OF THE PROTECTIVE ANTIBODIES OF THE SERUM. AB - Vaccination of susceptible mice with St. Louis encephalitis virus induced an acquired immunity to intracerebral inoculation which appeared within 1 week. When first demonstrable this immunity was at a very high level and it remained so for about 6 weeks, after which time it declined and disappeared completely between the 12th and 20th week after vaccination. Humoral antibodies of significant titre could not be demonstrated during the first 6 weeks after vaccination when actual immunity to intracerebral inoculation was at its highest level. Antibodies were first detected 8 weeks after vaccination, when immunity was decreasing. The humoral antibody titre reached its peak at 23 weeks, at which time immunity had completely disappeared. A high level of circulating antibody was still present 37 weeks after vaccination. The evidence presented leads to the conclusion that humoral antibodies do not play a major part in the immunity acquired by susceptible mice after vaccination against St. Louis encephalitis virus. PMID- 19870788 TI - SENSITIZATION AND ANTIBODY FORMATION WITH INCREASED RESISTANCE TO TUBERCULOUS INFECTION INDUCED BY HEAT KILLED TUBERCLE BACILLI. AB - Rabbits (and human beings) differ widely in the rapidity with which they undergo sensitization with heat killed tubercle bacilli, but after repeated injections all animals become sensitized. Intracutaneous injection of a small quantity of heat killed tubercle bacilli into a previously normal animal produces a nodule which persists from 8 to 12 weeks; the same injection into well sensitized animals produces a lesion which ulcerates within from 1 to 3 weeks and is completely healed after about 5 weeks. Complete healing is functional evidence of the disappearance of the antigen. Intracutaneous injection of heat killed tubercle bacilli induces more rapid sensitization than subcutaneous or intravenous injection, but after repeated injections the difference disappears. Increasing quantities of heat killed tubercle bacilli or the same quantity divided into several simultaneous injections accelerates sensitization. The rapidity of antibody formation measured by complement fixation varies in different rabbits under the same conditions but complement fixation is always demonstrable after repeated injections of heat killed tubercle bacilli. Antibody formation is more rapid and reaches higher titers with intravenous than with intracutaneous or with subcutaneous injections. It is accelerated by division of the injected antigen into multiple simultaneous injections. Small quantities of BCG induce rapid sensitization and more abundant antibody formation measured by complement fixation than heat killed tubercle bacilli but with repeated injections the difference disappears. Animals that are sensitized and immunized (allergic) before infection are in most instances more resistant to infection than previously normal animals, but there is no correlation between the intensity of sensitization or the titer of antibodies, on the one hand, and resistance to infection on the other. A previously normal animal subjected to infection differs essentially from a sensitized and immunized animal during the first few weeks of infection when sensitization and immunity are developing as the result of infection, but subsequently the progress of sensitization and antibody formation measured by the means at our disposal follows for a time the same course in both. Sensitization diminishes and in most instances disappears, whereas the titer of complement fixation remains elevated. When infection pursues a fatal course sensitization permanently disappears, but in animals that proceed toward recovery sensitization measured by injection of tuberculin into the skin repeatedly diminishes, usually to complete disappearance, and then increases in successive waves which tend to diminish in height with recovery from infection. The titer of complement fixation gradually diminishes with recovery from infection. It is probable that the skin test for sensitization and complement fixation applied to the blood serum measure antibodies or other factors determining sensitization and immunity that are in excess of those actively concerned in the maintenance of resistance. PMID- 19870789 TI - THE EFFECT OF SEX HORMONES ON THE RENAL EXCRETION OF ELECTROLYTES. AB - In normal male dogs subcutaneous injections of progesterone, estrone, alpha estradiol or testosterone propionate were followed by a decreased renal excretion of sodium and chloride. The compounds differed markedly in their potency and in the duration of the effect following a single subcutaneous injection. The injection of estrone, alpha-estradiol or testosterone propionate was followed by a decreased renal excretion of inorganic phosphorus and total nitrogen. On the day of injection a slight increase in the renal excretion of potassium frequently followed administration of progesterone, estrone, alpha-estradiol or testosterone propionate. Experiments on suprarenalectomized dogs indicated that the effect of the sex hormones on the renal excretion of electrolytes was not necessarily mediated through the suprarenal gland. With the possible exception of progesterone none of the compounds studied was effective in prolonging the life of suprarenalectomized male dogs. PMID- 19870790 TI - PROPAGATION OF THE VIRUS OF HUMAN INFLUENZA IN THE GUINEA PIG FETUS. AB - The PR8 strain of human influenza virus was found to proliferate and disseminate widely in the tissues of fetal guinea pigs inoculated in utero. Large quantities of virus free of bacteria were recovered from lung, liver, and placenta, and smaller quantities from blood and brain, after incubation periods ranging from 2 to 6 days. Although the fetuses proved to constitute an excellent medium for the propagation of influenza virus, they evinced little gross reaction to the infection. Several series of passages from fetus to fetus were accomplished; one consisted of 10 transfers, another of 16. For serial passage the virus was inoculated intracerebrally into half-grown fetuses and the fetal lungs were harvested 48 hours later as a source of virus for subinoculation. It is concluded that multiplication of the virus occurred particularly in the lungs, which may be considered a significant reaffirmation of the pneumotropic tendencies of this virus. Following passage in series the virus was found, on the basis of cross immunity and cross-neutralization tests, to be immunologically identical with the mouse passage virus from which it was derived. Other properties also appeared to be unaltered by passage of the virus under these conditions. PMID- 19870791 TI - ALTERED CUTANEOUS CONDITIONS IN THE SKIN OF TUBERCULOUS GUINEA PIGS AS DEMONSTRATED WITH A VITAL DYE. AB - 1. In the skin of the tuberculous guinea pig while it is allergic, the spread of a vital dye, pontamine sky blue, and the drainage of the dye into the vascular system take place much more slowly than in the normal animal. 2. In the skin of moribund tuberculous guinea pigs, animals no longer allergic, dye spreads more rapidly than in the normal animal. 3. The spread of dye is somewhat restricted in the skin of guinea pigs infected with a hemolytic Streptococcus. The animals were allergic. 4. The findings suggest that the dye method may disclose altered tissue conditions in the allergic state. PMID- 19870792 TI - STUDIES ON THE ANTIGENIC STRUCTURE OF SOME MAMMALIAN SPERMATOZOA. AB - 1. A method has been described for separation of heads and tails of mammalian spermatozoa. 2. By means of absorption technique applied to homologous spermatozoal sera, head-specific and tail-specific antigens could be demonstrated. Both are heat-labile. 3. A heat-stable antigen was found to be common to both heads and tails. This substance is species-specific. 4. Antibodies against the head- and tail-specific antigens led to two different types of agglutination as shown by the slide method. 5. Using heterologous antisera against spermatozoa three different cross-reacting antigens could be observed, two in the heads, one in the tails. 6. One of the head-antigens is not active in the native cell; it comes to action only after breaking the cell. Antibodies against this substance were not found in antisera against native bull spermatozoa but were formed when vibrated spermatozoa or heads were injected into rabbits. 7. The cross-reactions can be removed from an antiserum leaving the head- as well as the tail-specific reaction intact. PMID- 19870793 TI - THE EFFECT OF THE PULSE UPON THE FORMATION AND FLOW OF LYMPH. AB - The ears of rabbits were perfused with defibrinated rabbit's blood in such a way that pulsation could be imparted to the perfusate or withheld from it at will. In the absence of pulsation there was almost no lymph flow, whereas when it was present lymph flow was rapid despite the fact that the "systolic" pressure of the perfusate never exceeded the constant pressure in the non-pulsatile instances and the volume flow was far less. Non-pulsatile perfusion led to a slight flow of lymph in ears that were becoming edematous, whereas when it was pulsatile the lymph flow was enormous. The pulse exercises an influence to move fluid into the lymphatics and along them. PMID- 19870794 TI - THE EFFECT OF THE PULSE ON THE SPREAD OF SUBSTANCES THROUGH TISSUES. AB - The pulsation of blood vessels in the ear of the rabbit greatly increases the rate of the spread of dye introduced into the subcutaneous tissue. The appearance of edema in tissues perfused at a constant pressure leads to very little increase in the rate of dye spread. By contrast, a rapid interstitial spread of dye occurs in tissues becoming edematous while perfused with a pulsatile flow of blood. The significance of these facts is discussed. PMID- 19870795 TI - THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : I. THE RESPONSE OF MICE TO THE NASAL INSTILLATION OF VACCINIA VIRUS. AB - A catarrhal reaction manifested by a coryza and a pneumonia of characteristic pathology was regularly produced in mice by the nasal instillation of vaccinia virus. Inoculation into embryonated eggs indicated that the virus entered the circulation as early as the 2nd day after injection. The vaccinial catarrh was readily transmissible by the passage of nasal exudate but not by contact. Dosage was important in establishing the virus in the nasal passages, the limiting dilution being approximately 10(-3) of an egg membrane suspension (at least 1000 times the amount required to infect an embryonated egg). The morbidity rate was variable but in general high, reaching 70 per cent in 2 groups of 50 mice. An immunity which was effective against reinfection for several months but ultimately declined was attendant on recovery. The amount of virus required to produce this immunity was significantly less than the infective dosage. PMID- 19870796 TI - MOLECULAR WEIGHT, ELECTROCHEMICAL AND BIOLOGICAL PROPERTIES OF TUBERCULIN PROTEIN AND POLYSACCHARIDE MOLECULES. AB - Studies have been made by means of sedimentation in the ultracentrifuge, and by diffusion and electrophoresis, to determine the molecular weights and homogeneity of the tuberculin protein and polysaccharide molecules as found in their natural state in the unchanged filtrates from culture media after growth of tubercle bacilli. These results have been compared with data obtained on fractions isolated by chemical procedures from them or from old tuberculin. By means of electrophoresis in the Tiselius apparatus it was possible to separate the protein from the polysaccharide, as these two fractions occur naturally in the original culture medium filtrates of acid-fast bacilli. The protein from the bovine strain of bacillus proved to be homogeneous in sedimentation (S(20) = 1.6), diffusion (D(20) = 12.0) and electrophoresis, with a molecular weight of about 10,000. The tuberculin polysaccharide isolated in electrophoresis appeared to be practically the same in sedimentation and in precipitin reaction as the polysaccharide isolated by chemical procedure. The latter proved to be homogeneous in sedimentation (S(20) = 1.6) and diffusion (D(20) = 11.0) with a molecular weight of about 9000. A practically homogeneous protein was isolated from the culture filtrate of the human tubercle bacillus H 37 by fractional ammonium sulfate precipitation, with a molecular weight of 32,000 (S(20) = 3.3; D(20) = 8.2). It was electrochemically homogeneous, with an isoelectric point at pH 4.3 and an isoionic point at pH 4.7. It could be dried or frozen with no loss in homogeneity. It was highly antigenic in the precipitin reaction and produced the anaphylactic type of local skin reaction in tuberculous guinea pigs, in contrast to the true tuberculin type of reaction caused by a purified PPD fraction. Furthermore death resulted in tuberculous guinea pigs from intracutaneous injection of exceptionally small amounts. A protein with molecular weight of about 17,000 was isolated from the filtrate from cultures of the timothy bacillus. The nucleic acid originally occurring in old tuberculin (OT) seems to be responsible for the high electrochemical mobility observed. From OT and the PPD made from it, potent but non-antigenic molecules of 16,000 and 9000 weight and with a low content of nucleic acid were isolated. With increase in size these deviated much from the normal compact spherical shape, and aggregation was evident from the tendency toward gel formation. The smallest molecule (9000) was homogeneous (S(20) = 1.0; D(20) = 10.0) and had lost some tuberculin potency. PMID- 19870797 TI - RENAL FUNCTION AS AFFECTED BY EXPERIMENTAL UNILATERAL KIDNEY LESIONS : I. NEPHROSIS DUE TO SODIUM TARTRATE. AB - 1. A method is described for the production of a nephrosis in one kidney of an experimental animal. The normal kidney in the same animal is available for a control. 2. The nephrosis produced by the injection of 7.5 per cent sodium tartrate is limited to the proximal convoluted tubule. There is no histological evidence of glomerular damage. 3. This damage results in a disturbance of water and chloride excretion as well as a decrease in the clearances of urea, xylose, inulin, creatinine and phenol red, and is observed under conditions of no diuresis, sugar diuresis and salt diuresis. 4. Excreted ferrocyanide is found in the cells of the proximal tubule of the damaged kidney. It is not present in these cells in the normal kidney. This is taken to be evidence of back diffusion of ferrocyanide through the damaged cells. 5. The decrease in clearance of creatinine and inulin, which in the dog represent glomerular filtrate, may therefore be explained by back diffusion and is not necessarily due to glomerular change. 6. The phenol red clearance from the damaged kidney is diminished in relation to inulin. This is further evidence of depressed tubular activity. PMID- 19870798 TI - CARCINOMA IN THE LEOPARD FROG: ITS PROBABLE CAUSATION BY A VIRUS. AB - An epithelial tumor with acidophilic intranuclear inclusions frequently occurs in the kidneys of leopard frogs. This tumor usually has the appearance of an infiltrating and destructive adenocarcinoma, which, when large, not uncommonly metastasizes; less often it is more orderly and adenomatous. When inoculated as living fragments or cell suspensions into the lymph sacs, the cranial cavity, or the abdomen, no significant local growth results and the implanted material is resorbed. However, in approximately 20 per cent of the frogs surviving inoculation for more than 6 months, tumors develop in the kidney, which are like the "spontaneous" neoplasms. The incidence far exceeds that in the controls. Desiccated and glycerinated tumor injected into the abdomen gives the same result as inoculation with living tumor; in somewhat over 20 per cent of animals surviving more than 6 months kidney tumors occur. In alien species of frogs, no such tumors are produced by inoculation either with living or with desiccated tumor. These experiments indicate the probability that the kidney tumor of the leopard frog is caused by an inclusion-forming, organ-specific virus. PMID- 19870799 TI - CHEMO-IMMUNOLOGICAL STUDIES ON CONJUGATED CARBOHYDRATE-PROTEINS : XII. THE IMMUNOLOGICAL PROPERTIES OF AN ARTIFICIAL ANTIGEN CONTAINING CELLOBIURONIC ACID. AB - 1. Artificial antigens containing the azobenzyl glycosides of the disaccharide cellobiose and the aldobionic acid, cellobiuronic acid, give rise in rabbits to antibodies which are specific and characteristic of the saccharide constituent. The antiserum to cellobiuronic acid shows broader serological cross reactions than does that to cellobiose. 2. An antiserum to the cellobiuronic acid antigen precipitates the capsular polysaccharide of Type III Pneumococcus when the latter is combined with a heterologous protein. 3. The cellobiuronic acid test antigen precipitates vigorously in antipneumococcus sera Types II, III, and VIII. The mechanism of these reactions is discussed. PMID- 19870800 TI - RENAL INSUFFICIENCY FOLLOWING TRYPSIN INJECTION INTO THE RENAL ARTERIES. AB - 1. The injection of trypsin into both renal arteries of the dog was found to cause an acute necrosis of large sections of the kidney, an immediate excretory insufficiency, and a transient hypertension. 2. Dogs surviving the acute phase of the trypsin injection, developed a chronic renal excretory insufficiency with no hypertension, despite the severity and duration of the renal excretory insufficiency. 3. The application of a Goldblatt clamp to the renal artery of one of the two kidneys, previously injected with trypsin, led to a rise in blood pressure which returned at once to normal when the ischemic kidney was removed, even though the pre-existing renal excretory insufficiency was augmented. This experience demonstrated unequivocally that chronic renal excretory insufficiency and hypertension are not directly related. 4. The application of a Goldblatt clamp to the renal artery of one kidney and the simultaneous injection of trypsin into the other led to a hypertension. The later removal of the ischemic kidney led to a severe renal excretory insufficiency, at the same time the pre-existing hypertension disappeared. This indicated again that renal excretory insufficiency and renal ischemia produced different phenomena and that the former had no direct relation to hypertension. PMID- 19870801 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : V. SENSITIZATION TO DIAZOMETHANE AND MUSTARD OIL. AB - With the view of making new types of chemicals accessible for investigations on drug hypersensitiveness, methods have been devised for sensitizing animals with diazomethane and mustard oil, two non-aromatic compounds. Guinea pigs have been sensitized to diazomethane, a substance of high reactivity and known to cause severe allergic effects in man. With the second substance, allylisothiocyanate, likewise capable of forming conjugates with substances in the animal body, sensitization effects have been obtained in man and in hogs. Sensitization in human beings was successful with one out of six individuals treated. The observations indicate species and individual differences as regards the ability to become sensitized to various chemical compounds. PMID- 19870802 TI - A PYOGENIC FILTERABLE AGENT IN THE ALBINO RAT. AB - A filterable agent resembling the viruses is described. It was encountered in sarcoma 39, a propagable neoplasm of the white rat, and has now been maintained in this species for 28 passages over a period of some 7 months without appreciable loss in virulence. Its chief effect is the production of large abscesses in an animal species comparatively resistant both to viral diseases and suppuration. The white mouse is more susceptible than the white rat, the rabbit less so, and the guinea pig highly resistant. The agent has been repeatedly recovered from sarcoma 39 treated in special ways, but under the ordinary circumstances of routine transplantation it does not manifest itself. As yet there is no certainty on where it came from or how it maintains itself under natural conditions. PMID- 19870803 TI - THE CARCINOGENIC EFFECT OF A PAPILLOMA VIRUS ON THE TARRED SKIN OF RABBITS : II. MAJOR FACTORS DETERMINING THE PHENOMENON: THE MANIFOLD EFFECTS OF TARRING. AB - A considerable variety of tumors, both benign and malignant, result from the localization of the rabbit papilloma virus in skin which has been prepared by repeated tarrings. They appear only in individuals highly susceptible to the action of the virus, and are more likely to be engendered by highly pathogenic inocula. No evidence has been found that differences in the potentialities of the virus entities are responsible for the diversity of the growths. This is referable to changes in the epidermal cells; and much more preliminary tarring is required to produce these changes than suffices to cause localization of the virus out of the blood stream with a resulting papillomatosis of the ordinary sort. The character of the individual anomalous tumors depends in some degree upon the extent of the preparatory changes in the cells, malignant growths being more frequent when the epidermis has been tarred for a relatively long period. All are focal or punctate in origin, and they exhibit their peculiar characters from the first, none being due to secondary alterations in ordinary papillomas. Tarring after the virus has localized in the epidermis does not significantly increase their number. They are the outcome of the state of the cells at the time of virus infection. Tarring exerts important influences in addition to changing the cells in such a way that unusual tumors result from the action of the virus. The procedure is notably effective in determining localization of the virus out of the blood stream; enables it to produce growths when otherwise it would not do so though present in the tarred skin; stimulates the proliferation of the tumors engendered; makes them disorderly and aggressive; and hastens the anaplasia of such of them as are malignant. It has similar effects upon the tar tumors, as will be demonstrated in a subsequent paper. PMID- 19870804 TI - CELLULAR REACTIONS TO POLYSACCHARIDES FROM TUBERCLE BACILLI AND FROM PNEUMOCOCCI. AB - 1. Purified tuberculo-polysaccharides are relatively innocuous both to normal and to tuberculous guinea pigs. 2. Both tuberculo-polysaccharides and polysaccharides from pneumococci call larger numbers of leucocytes from the blood vessels than do saline and dextrose and trehalose. 3. The mechanisms controlling the delivery of lymphocytes and neutrophils into the blood stream are different. 4. Slight irritation of the peritoneal lining slows the delivery of lymphocytes to the blood stream. 5. There are two phases in the reaction of the bone marrow to intraperitoneal injections. Correlated with the draining of neutrophils from vessels to tissues, owing to the presence of foreign materials in the latter, there is a draining of young neutrophils from the marrow into the sinuses of the marrow as these same materials reach the sinuses. The subsequent disintegration of the neutrophils extravasated into the tissues is correlated with increased myeloid activity in the marrow. PMID- 19870805 TI - ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS : I. GENERAL METHODS AND DETERMINATION OF PARTICLE SIZE. AB - Ultracentrifugal studies on the CL dermal strain of vaccine virus indicate the following characteristics of the elementary bodies:- 1. A stable suspension of Paschen bodies in a dilute buffer solution of pH 6.2 to 8 sediments with the formation of a characteristic primary boundary which consistently shows a spread of approximately 14 per cent. 2. The principal sedimentation boundary is accompanied frequently by one or several more rapidly moving boundaries which probably are produced by groups of agglutinated elementary bodies consisting of two or more particles. 3. Occasionally the principal boundary may exhibit an irregular or peculiar behavior, a fact which necessitates a careful selection of material and the performance of many experiments for accurate interpretation of results. 4. The sedimentation constant of the slowest moving particles forming the principal boundary is computed to be 49.1 x 10(-11) cm./sec./dyne. On the basis of this sedimentation rate, the average diameter of the smallest virus particles in appreciable amounts is estimated at 236 mmicro. If the boundary spread is due principally to slight differences in particle size, then the largest single elementary bodies are approximately 252 mmicro in diameter. PMID- 19870806 TI - ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS : II. THE INFLUENCE OF SUCROSE, GLYCEROL, AND UREA SOLUTIONS ON THE PHYSICAL NATURE OF VACCINE VIRUS. AB - ULTRACENTRIFUGAL STUDIES OF THE CL DERMAL STRAIN OF VACCINE VIRUS WARRANT THE FOLLOWING CONCLUSIONS: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest with sucrose and most marked with urea. The normal rate of sedimentation of Paschen bodies may be restored by resuspending them in dilute buffer solution. 2. The density of elementary bodies of vaccinia suspended in dilute buffer solutions is estimated to be 1.16 gm. per cc. Higher values for the density are found if the particles are suspended in solutions containing sucrose, glycerol, or urea. In 53 per cent sucrose, for example, the density is 1.25 gm. per cc. 3. Paschen bodies appear to be quite permeable to water and urea, less so to glycerol, and only slightly, if at all, to sucrose. 4. The increased density of the elementary bodies of vaccinia in sucrose solutions may be accounted for by an osmotic extraction of water from the particles. On this basis the water which can be thus extracted corresponds to at least a third of the original volume of the particles. PMID- 19870807 TI - THE LYMPHATIC PATHWAY FROM THE NOSE AND PHARYNX : THE ABSORPTION OF DYES. AB - 1. In the monkey, dog, cat, and rabbit the cervical lymph duct was cannulated, and then a solution of T-1824, or trypan blue, or a fine graphite suspension, all in physiological saline, was dropped into the nose. T-1824 was used in all four animals, trypan blue in the cat and dog, the graphite suspension (Hydrokollag) in the cat alone. 2. No Hydrokollag was ever found in the cervical lymph. 3. Trypan blue and T-1824 appear in the cervical lymph 15 to 30 minutes after being placed in the nose of the cat and monkey, 51 to 53 minutes in the dog, and 14 minutes in the rabbit. 4. T-1824 and trypan blue were also absorbed from the nose directly into the blood. 5. Neither the dyes nor the Hydrokollag, though left in the nose for as long as 6 hours, were found to pass through the cribriform plate and reach the interior of the cranium. 6. In the monkey cervical lymph passes through a chain of five or more lymph nodes, in the rabbit frequently through two nodes, in the cat through one node except in rare instances, and in the dog through one node. PMID- 19870808 TI - REACTIONS OF NORMAL AND TUBERCULOUS ANIMALS TO TUBERCULO-PROTEIN AND TUBERCULO PHOSPHATIDE. AB - Prior observations on the cellular reactions to tuberculo-phosphatide are confirmed and compared with reactions induced by this material in tuberculous animals. In the latter the response is accelerated and augmented and simulates the Koch phenomenon. Tuberculo-protein produces no macroscopic reaction in normal animals. The microscopic reaction of neutrophiles and monocytes regresses in less than a week. The same material in tuberculous animals causes a response characterized by more or less hemorrhage and necrosis, tissue degeneration, and infiltration of neutrophiles and monocytes. Late in the reaction there may be a few epithelioid cells and foreign body giant cells. Preparations of tuberculo phosphatide which contain no tubercle bacilli, or only a few, induce the typical cellular response but do not induce hypersensitiveness to tuberculin. Repeated intradermal skin-test injections of tuberculo-protein MA-100 in normal guinea pigs may be followed by a mild hypersensitiveness to subsequent injections. PMID- 19870809 TI - TUBERCULAR ALLERGY WITHOUT INFECTION. AB - 1. Guinea pigs can be rendered hypersensitive to tuberculo-protein by small, repeated, intradermal injections of active tuberculo-protein. 2. The addition of tuberculo-phosphatide to the protein speeds up the process of sensitization and enhances it so that the reactions become indurated and necrotic, closely simulating those of the disease. 3. Active tuberculo-proteins induce a new formation of monocytes and some epithelioid cells. The addition of phosphatide to the protein brings about a massive formation of epithelioid cells. 4. With the increased cellular reaction to the mixed injections may be correlated the increase in the speed and intensity of the sensitization. 5. The intradermal route is the best for these sensitizations, probably because it provides the greatest dose per cell of the sensitizing agent. 6. The degree of sensitization artificially obtainable by the synergistic action of tuberculo-phosphatide and tuberculo-protein is quite comparable to the degree of sensitization naturally occurring in tuberculous animals; moreover, this degree of sensitization may be induced with amounts of the materials from the bacilli which could conceivably be present in the tissues of an infected host. PMID- 19870810 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : I. HISTOPATHOLOGY OF THE NERVOUS SYSTEM IN THE GUINEA PIG. AB - The action of the virus of equine encephalomyelitis in the guinea pig brain has been studied, and various histological changes have been described in detail. After peripheral inoculation (as in the pad) the earliest detectable pathologic change in the nervous system is the accumulation of leucocytes within the lumen of blood vessels, and the proliferation of the vascular adventitia. This precedes the appearance of any significant perivascular cuffing, and may or may not be accompanied by a few polymorphonuclear leucocytes in the tissue. The typical lesion is a fairly well circumscribed focus of polymorphonuclear leucocytes accompanying the blood vessel changes described above. The leucocytes may be numerous or sparse, and may or may not be accompanied by neuronal destruction. In early cases, before the onset of symptoms, such circumscribed lesions appear in small number irregularly scattered through the gray matter. The neo- and olfactory cortices are the principal sites of predilection, although basal ganglia, thalamus, cerebellum, and lower olfactory centers may also be involved. The hippocampus is much less affected than other parts of the brain. A rough distinction is made between inflammatory and degenerative lesions, a distinction which depends on the relationship between the neuronal destruction and the exudative changes in any given site. These two types are described, and their significance is discussed. After intracerebral inoculation, the inflammatory changes are much less marked than after peripheral inoculation. This is due not to insufficient time for the development of lesions but to a different type of pathological process. Following intracerebral inoculation, there is primary destruction of neurones, involving especially the hippocampus, and also large areas of the neo-cortex. This change, similar to ischemic necrosis, is regarded in part as a non-specific reaction of especially vulnerable tissue. PMID- 19870811 TI - THE PRODUCTION BY A NEW METHOD OF RENAL INSUFFICIENCY AND HYPERTENSION IN THE RABBIT. AB - A simple method is described for the production of renal insufficiency in rabbits by limiting the blood flow through one kidney and later removing the other. Renal insufficiency of any desired degree of severity can be obtained. The limitation of blood flow should be produced by allowing the artery to grow up to the size of a loop of thread laid around it when the rabbit is small. Attempts to reduce the blood flow by constricting the renal artery in the adult rabbit usually result in necrosis of the kidney. The induction of renal insufficiency is usually followed by loss of weight and disturbance of the equilibrium apparatus. Hemorrhages into the intestinal wall and into the lumen of the intestine are frequent. A moderate degree of anemia, as judged from hematocrit readings, comes on very rapidly after reduction in total kidney mass. The total red blood cell volume seems to assume a new and lower level which is maintained for a long time. Hypertension is present before the right kidney ablation and becomes more severe after this operation. A certain degree of hypertension can be produced in adult rabbits by moderate restriction of renal blood flow of one kidney. The severity of this is increased by removal of the other kidney. PMID- 19870812 TI - IMMUNOLOGICAL REACTIONS WITH A VIRUS CAUSING PAPILLOMAS IN RABBITS : I. DEMONSTRATION OF A COMPLEMENT FIXATION REACTION: RELATION OF VIRUS-NEUTRALIZING AND COMPLEMENT-BINDING ANTIBODIES. AB - The sera of rabbits bearing virus-induced papillomas have been found to bind complement when mixed with antigens consisting of extracts or filtrates of the growths containing the virus. The sera of normal rabbits, of those immune to other viruses (vaccinia, herpes, fibroma, myxoma), of rabbits with syphilis, or of those with papillomas consequent on tarring, did not fix complement upon admixture with the papilloma antigens. The complement-binding antibody was present in the serum specimens in the same relative proportions as the virus neutralizing antibody, and both were present in greatest amount in the sera of rabbits that had borne large papillomas over considerable periods of time. A few sera were come upon that neutralized small amounts of the virus yet failed to bind complement to any noteworthy degree in the tests. The sera of cottontail rabbits fixed complement and neutralized the virus in much higher titer than the sera of domestic rabbits with comparable growths. The implications of the findings will be discussed in a subsequent paper, after the properties of the complement-binding antigen have been scrutinized. PMID- 19870813 TI - IMMUNOLOGICAL REACTIONS WITH A VIRUS CAUSING PAPILLOMAS IN RABBITS : II. PROPERTIES OF THE COMPLEMENT-BINDING ANTIGEN PRESENT IN EXTRACTS OF THE GROWTHS: ITS RELATION TO THE VIRUS. AB - The antigen that binds complement in the presence of sera neutralizing the Shope papilloma virus can be readily extracted from papillomas yielding infectious virus, but not from the normal skin of rabbits bearing the growths. The virus and the complement-binding antigen appear to have the same particle size, as determined by filtration, and they are thrown down together in the centrifuge. They are destroyed by the same amounts of heating and, in general, by the same changes in pH. It is possible, nevertheless, by irradiation with ultraviolet light, or by treatment with weak alkali, to render papilloma extracts non pathogenic without diminishing their capacity to bind complement when mixed with immune serum. PMID- 19870814 TI - IMMUNOLOGICAL REACTIONS WITH A VIRUS CAUSING PAPILLOMAS IN RABBITS : III. ANTIGENICITY AND PATHOGENICITY OF EXTRACTS OF THE GROWTHS OF WILD AND DOMESTIC SPECIES: GENERAL DISCUSSION. AB - A study has been made of the yield of virus and of the complement-binding antigen from the virus-induced papillomas of cottontail and domestic rabbits. Extracts of the discrete, naturally occurring papillomas of cottontail rabbits usually contain virus in large amount; and, as a rule, they also contain the complement binding antigen in high titer. The confluent growths produced experimentally with the virus in some cottontails, on the other hand, often fail to yield the virus, or furnish it in small amount; and extracts of them have little if any complement binding capacity. The sera of cottontails with massive papillomas from which the virus cannot be recovered often have high antibody titers. Many extracts were tested of the virus-induced papillomas of domestic rabbits. None contained the virus in large amount, and the majority of them failed to manifest it on sensitive test. A few fixed complement in low titer when mixed with immune sera, but most failed to do so. Crude extracts of the "non-infectious," virus-induced papillomas of domestic rabbits stimulated the formation of virus-neutralizing and complement-binding antibodies in low titer when injected intraperitoneally into normal rabbits of the same breed, but Berkefeld filtrates of the same materials proved devoid of this immunizing effect. The significance of the findings described in the three papers is discussed. The evidence as a whole favors the view that the virus stimulates the formation of the virus-neutralizing and complement-binding antibodies in vivo, and many facts indicate that it is closely associated, and in all probability identical, with the antigen that reacts with immune serum to fix complement in vitro. PMID- 19870815 TI - INTRAPERITONEAL AND INTRACEREBRAL ROUTES IN SERUM PROTECTION TESTS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : II. MECHANISM UNDERLYING THE DIFFERENCE IN PROTECTIVE POWER BY THE TWO ROUTES. AB - Minute amounts of antiserum injected intraperitoneally protect against large doses of equine encephalomyelitis virus given intramuscularly or intraperitoneally in 12 to 15 day old mice. Antiserum given intraperitoneally with virus intracerebrally or intranasally results in little or no protection. These phenomena occur as well when serum-virus mixtures are injected at the different sites. The marked variation of the protective capacity of antiserum as thus displayed would appear to be dependent upon the differing pathways of progression of the virus from the site of injection to the central nervous system. PMID- 19870816 TI - INTRAPERITONEAL AND INTRACEREBRAL ROUTES IN SERUM PROTECTION TESTS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : III. COMPARISON OF ANTIVIRAL SERUM CONSTITUENTS FROM GUINEA PIGS IMMUNIZED WITH ACTIVE OR FORMOLIZED INACTIVE VIRUS. AB - Earlier experiments had shown that the sera of animals immunized with active virus have much greater protective potency when serum-virus mixtures are injected intraperitoneally into 12 to 15 day old mice than when given intracerebrally. The present work was concerned with similar tests on sera derived from guinea pigs immunized by vaccines in which the virus had been inactivated by formalin. In comparing the content of antiviral body by means of intracerebral and by intraperitoneal inoculation, it was found that both sera show about the same low degree of neutralizing capacity by the former method. By intraperitoneal inoculation, on the other hand, serum collected from guinea pigs immunized by means of active virus reveals high protective power, while that from animals receiving formolized, inactive virus exhibits lower neutralization titers which approach those obtained by the intracerebral method. The significance of this unexpected finding is discussed. PMID- 19870817 TI - STUDIES ON THE NASAL HISTOLOGY OF EPIDEMIC INFLUENZA VIRUS INFECTION IN THE FERRET : I. THE DEVELOPMENT AND REPAIR OF THE NASAL LESION. AB - A study has been made of the nasal histology in normal ferrets and in ferrets during and after infection with epidemic influenza virus. During the acute stage of infection the respiratory epithelium of the nasal mucous membrane undergoes necrosis with desquamation of the superficial cells and exudation into the air passages, and an inflammatory reaction occurs in the submucosa. Repair begins on the 4th day after infection, and from the 6th to the 14th day the respiratory area is covered successively by a transitional, a stratified squamous, and finally a stratified columnar epithelium. By the 21st day after infection the epithelium has been largely restored to normal but repair in the submucosa and cartilage is still in progress. The respiratory mucosa is substantially normal in structure 1 month after infection although minor abnormalities of cellular arrangement and type can still be distinguished. PMID- 19870818 TI - STUDIES ON THE NASAL HISTOLOGY OF EPIDEMIC INFLUENZA VIRUS INFECTION IN THE FERRET : II. THE RESISTANCE OF REGENERATING RESPIRATORY EPITHELIUM TO REINFECTION AND TO PHYSICOCHEMICAL INJURY. AB - Because of the marked morphological abnormality of the nasal respiratory epithelium in ferrets recovering from epidemic influenza virus infection, attempts were made to determine whether the anatomical changes were associated with functional changes in the epithelial cells. It was found that on the 7th or 8th day after infection, at which time an immature transitional type of epithelium covers the respiratory area, the cells are resistant not only to reinfection with influenza virus but to a severe physicochemical stimulus supplied by iontophoresis or prolonged irrigation with zinc sulfate. Later, as the ciliated columnar cells return, susceptibility to physicochemical injury returns although resistance to influenza virus persists. The ciliated columnar cells are the ones which are damaged by the physicochemical agent while the deeper cells in the regenerating area remain unaffected. 5 weeks after infection the epithelium is anatomically normal but tissue resistance to zinc sulfate is still present to some degree as evidenced by foci of undamaged cells remaining after ionization. The olfactory epithelium which is undamaged by the PR8 strain of epidemic influenza virus also becomes resistant to ionization after infection. As soon as the respiratory epithelium exhibits any loss of resistance to zinc sulfate the chemical produces complete necrosis of the olfactory area. The refractory state to physicochemical agents exhibited by the regenerating nasal mucosa of the ferret after influenza virus infection is thought to be a non specific resistant state, significant for a time at least, in the mechanism of immunity to influenza virus. PMID- 19870819 TI - STUDIES ON THE NASAL HISTOLOGY OF EPIDEMIC INFLUENZA VIRUS INFECTION IN THE FERRET : III. HISTOLOGICAL AND SEROLOGICAL OBSERVATIONS ON FERRETS RECEIVING REPEATED INOCULATIONS OF EPIDEMIC INFUENZA VIRUS. AB - A study of the respiratory mucous membrane was made in the turbinates of ferrets which had received repeated inoculations of influenza virus. There was no evidence that persistent immunity is related to the presence of a structural modification of the respiratory epithelium. In fact, the respiratory epithelium in fully immune animals differs histologically only in minor respects from that of the normal, untreated ferret. On the other hand, a functional difference exists between the normal and the previously infected animals as evidenced by a marked acceleration of the repair process in the latter. Serological studies at the time of reinfection, 4 months or more after the previous attack, indicate that a relation exists between the height of antibody titer and resistance. The degree of immunity is probably a product of serological immunity and the rate of tissue repair. The implications of these studies to the problem of influenza in man are discussed. PMID- 19870820 TI - PLASMA PROTHROMBIN: EFFECT OF PARTIAL HEPATECTOMY. AB - Extirpation of a large portion of the liver in rats results in a marked decrease in the plasma prothrombin. The plasma prothrombin level gradually returns to normal during the period required for restoration of the liver to its normal weight. The decrease in prothrombin incident to partial hepatectomy supports the thesis that the liver is concerned in the manufacture of plasma prothrombin. PMID- 19870821 TI - CELLULAR REACTIONS TO TUBERCULO-PROTEINS COMPARED WITH THE REACTIONS TO TUBERCULO LIPIDS. AB - 1. Tuberculo-protein in solution induces the formation of monocytes in the normal animal and tubercles of epithelioid cells in that which is tuberculous. 2. Freshly precipitated tuberculo-proteins from the culture media and from the bacilli induce a moderate formation of epithelioid cells in normal animals, and more in the tuberculous. 3. Insoluble forms of tuberculo-protein induce complex tubercular tissue in normal animals. This action is enhanced in the tuberculous. PMID- 19870822 TI - CELLULAR REACTIONS TO DEFATTED TUBERCLE BACILLI AND THEIR PRODUCTS. AB - The cellular reactions to defatted tubercle bacilli are complex and like those to heat-killed whole tubercle bacilli. The firmly bound lipid, when removed from these organisms, is non-acid-fast; it contains an hydroxy acid which is acid-fast and a polysaccharide, which is not. This hydroxy acid gives rise to foreign body giant cells and the tissues eventually become infiltrated with eosinophiles. The polysaccharides, both from the defatted bacilli and from the unfilterable lipid, call neutrophiles from the blood stream. The reactions to the unfilterable lipid include those of both its constituents. PMID- 19870823 TI - NORMAL AND PATHOLOGICAL FACTORS INFLUENCING THE SPREAD OF A VITAL DYE IN THE CONNECTIVE TISSUE. AB - A method has been devised to measure the spread of vital dyes in the skin of mice. Spread is greatly influenced by physiological and pathological changes which add fluid to the tissue or abstract it. Spread is greater in the quiet, living ear than in the ear of an animal just killed. It is equally considerable in the frankly edematous ears of living and dead animals, and not greater in either case than in normal, quiet tissues. During the early stages of edema formation on the other hand, dye spread is notably rapid. It is still greater in the ears of normal animals actively moving about, and is greatest in tissues subjected to very gently intermittent changes in external pressure. The significance of these findings is discussed. PMID- 19870824 TI - A STUDY OF HUMAN SKIN GRAFTED UPON THE CHORIO-ALLANTOIS OF CHICK EMBRYOS. AB - Human skin grafted upon the chorio-allantoic membrane of chick embryos adheres and becomes nourished for as long as 10 days. Occasionally regrafts upon a second egg have succeeded and thus prolonged the vitality of the graft to 14 days. In successful experiments the epithelium of the chorio-allantois fuses with that of the graft, the collagen fibers of the corium interlace with those of the membrane after the separation or disappearance of the ectodermal layer, and the blood vessels of the chick anastomose, and unite by intervening pools of extravasated blood, with those of the graft. This vascular communication between the two tissues is largely responsible for the nourishment of the graft by affording a plasmatic circulation. Gradually there is a partial revascularization of the graft by an ingrowth of blood vessels from the chick membrane. Human skin grafts were susceptible to experimental infection by several viruses. PMID- 19870825 TI - THE SIGNIFICANCE OF HUMAN DOUBLE ZONE BETA HEMOLYTIC STREPTOCOCCI IN THE UDDER OF THE COW. AB - Human strains of double zone beta hemolytic streptococci produced mastitis in 11 quarters of 4 young cows. Following the acute phase of the infection, the streptococci were eliminated from 6 quarters at various intervals. However, sufficient positive infections were maintained throughout the period of observation to show that the human strains can produce the same degree of infection as bovine double zone beta hemolytic streptococci. PMID- 19870826 TI - QUANTITATIVE STUDIES ON ANTIBODY PURIFICATION : III. THE REACTION OF DISSOCIATED ANTIBODY WITH SPECIFIC POLYSACCHARIDE, AND THE EFFECT OF FORMALDEHYDE. AB - 1. Tested quantitatively, antibody recovered by dissociation of specific precipitates from antipneumococcus sera reacts with homologous polysaccharide almost as does the antibody in the original sera. 2. The dissociation methods employed appear to yield a portion of all of the anticarbohydrates of differing reactivities in the sera, rather than a fraction of low or high reactivity. 3. The reversible inactivation of purified pneumococcus anticarbohydrate by formaldehyde is confirmed, and the failure of data on the formaldehyde-antibody reaction to permit a choice between alternative theories of specific precipitation is shown. PMID- 19870827 TI - NUTRITIONAL CYTOPENIA (VITAMIN M DEFICIENCY) IN THE MONKEY. AB - Young rhesus monkeys (Macaca mulatta) were given a diet containing casein, polished rice, whole wheat, salt mixture, sodium chloride, cod liver oil, and ascorbic acid. They developed a syndrome characterized by anemia, leukopenia, and loss of weight. Ulceration of the gums and diarrhea were common, and death occurred between the 26th and 100th day. 4 monkeys were given the deficient diet supplemented with 1 mg. of riboflavin daily, and these developed the characteristic signs and died. in periods of time similar to the survival of monkeys receiving the deficient diet alone. Nicotinic acid, either alone or in combination with riboflavin and thiamin chloride, failed to alter appreciably the course of the deficiency manifestations. Thus, it is evident that this nutritional cytopenia is not the result of a deficiency of vitamin B, riboflavin, or nicotinic acid. The deficient diet supplemented with either 10 gm. of dried brewers' yeast or 2 gm. of liver extract (Cohn fraction G) daily supported good growth, permitted normal body development, and maintained a normal blood picture over long periods. It is obvious that yeast and liver extract contain a substance essential to the nutrition of the monkey which is not identical with any of those factors of the vitamin B complex that have been chemically identified. We have proposed the term vitamin M for this factor which prevents nutritional cytopenia in the monkey. PMID- 19870828 TI - THE LYMPHATIC PATHWAY FROM THE NOSE AND PHARYNX : THE ABSORPTION OF CERTAIN PROTEINS. AB - 1. In a number of cats, dogs, monkeys, and in a rabbit, the cervical lymph ducts were cannulated and protein solutions dropped into the nose, and the lymph was examined afterwards for the presence of the protein employed. 2. Egg albumin was found in the lymph in all cases with one exception. Horse serum was never detected. Serum albumin did not come through in the cats, but did in a rabbit. 3. With a 1 per cent solution of T-1824 in horse serum no dye appeared in the lymph. This is regarded as confirming Gregersen and Gibson's (2) view that T-1824 combines with the serum proteins. PMID- 19870829 TI - VASCULARIZATION OF THE CORNEA OF THE RAT IN RIBOFLAVIN DEFICIENCY, WITH A NOTE ON CORNEAL VASCULARIZATION IN VITAMIN A DEFICIENCY. AB - Vascularization of the cornea of the rat in the absence of antecedent pathology is probably a specific and the most reliable criterion of riboflavin deficiency. Its initiation and repair may be used for testing the biological activity of compounds structurally related to riboflavin. The facts that the invading capillaries are easily visible in the living animal and that the growth and regression of the blood vessels are under dietary control and for a considerable period of time unaccompanied by other pathological reactions, make this method very suitable for the study of problems related to capillary growth. We believe that the best hypothesis in explanation is that the vascularization is a response to asphyxia of the tunica propria. PMID- 19870830 TI - THE MOLECULAR WEIGHT OF ANTIBODIES. AB - 1. Highly purified preparations of homogeneous antibody can be made by the salt dissociation methods (6, 7) without any change in sedimentation due to the method of purification. 2. Antibodies prepared from sera of various animal species fall into two groups as regards molecular weight; in one group cow, horse, and pig, a heavy molecule of molecular weight 990,000 is formed; in human being, rabbit, and monkey, the molecular size is that of the normal gamma serum globulin. Both types of antibody molecules are either not compact or not spherical since the frictional ratios f/f(0) are 2.0 and 1.5 respectively. 3. Horse antibody shows an unchanged activity and sedimentation diagram between pH 3.44-9.06, although there is some aggregation at the more acid and some dissociation at the more alkaline pH. At pH 1.44 the antibody activity is unchanged but some breakdown of the molecule takes place. At pH 12.4 activity is destroyed and the molecule is completely broken down. 4. Some horse antibody preparations show evidence of breakdown of the antibody into inhomogeneous material on continued immunization over a long period. PMID- 19870831 TI - AN ELECTROPHORETIC STUDY OF IMMUNE SERA AND PURIFIED ANTIBODY PREPARATIONS. AB - 1. Antibody produced in the horse migrates as a new serum component between the beta and gamma components, whereas rabbit antibody is electrophoretically identical with the gamma globulin component of the serum. 2. In rabbit and monkey antisera the percentage of antibody in the serum and in the gamma globulin fraction can be determined by integration of the electrophoresis diagrams of unabsorbed and absorbed sera. Antibody solutions of high purity can be obtained by electrophoretic isolation of the gamma globulin of rabbit antisera in which the percentage of antibody to total gamma globulin is high. 3. The isoelectric points of pig, cow, horse, and rabbit antibodies have been determined. 4. In horse sera prolonged immunization is accompanied by the formation of another antibody component of lower mobility. PMID- 19870832 TI - A NEOPLASM OF MONOCYTES OF MICE AND ITS RELATION TO SIMILAR NEOPLASMS OF MAN. AB - A transmissible neoplasm of mice characterized by malignant cells resembling histiocytes (monocytes) is described. The morphology of these cells and the microscopic appearance of the lesions are similar to those of human neoplasms formed by histiocytes. The malignant histiocytes form tumor-like masses in the liver and spleen and infiltrate these and other tissues. They are present in small numbers in the blood of many mice when the disease is far advanced. The malignant cells have scant phagocytic ability. The fixed cells of the host (endothelial cells and fibroblasts) have no significant part in the production of the lesions of the disease. Transmission is readily accomplished when material containing the malignant histiocytes is used for inoculations, but fails in their absence. Attempts to demonstrate a cell-free transmitting agent have been unsuccessful. PMID- 19870833 TI - THE LYMPHATIC PATHWAY FROM THE NOSE AND PHARYNX : THE DISSEMINATION OF NASALLY INSTILLED VACCINIA VIRUS. AB - Vaccinia virus dropped into the nose of a susceptible animal does not appear in cervical lymph in less than 12 hours. After 12 hours, and thereafter continuously for 7 days, a stream of virus is entering the blood through the cervical lymph ducts. Virus passes through the lymph nodes. Virus is fixed by the lymphocytes, and the significance of this is discussed. PMID- 19870834 TI - A PRECIPITINOGEN IN THE SERUM PRIOR TO THE ONSET OF ACUTE RHEUMATISM. AB - 1. A precipitin reaction occurs between sera taken just before and shortly after the onset of acute rheumatism. 2. It recurs with repeated rheumatic cycles. 3. Certain properties of the precipitinogen and the precipitin are described. PMID- 19870835 TI - OBSERVATIONS ON THE RELATION OF THE EYE TO IMMUNITY IN EXPERIMENTAL SYPHILIS. AB - Three experiments are reported in which an attempt has been made to determine the extent to which the eye participates in the general resistance which develops in rabbits during the course of syphilitic infection. Rabbits treated with arsphenamine well after the period when they would be expected to be immune to intratesticular or intracutaneous inoculations were reinoculated with the homologous strain of T. pallidum, the organisms being injected into either the cornea itself or the anterior chamber. Altogether in the three experiments 43 presumably immune animals were injected, 25 into the cornea itself and 18 into the anterior chamber. 41 normal animals were used as controls. In the immune animals 27 or 62 per cent showed lesions in the cornea. 14 of the 43 test animals were inoculated simultaneously in the cornea and in the skin of the back. In 9 of these 14, lesions developed in the cornea although no lesions developed in the skin. The lesions developing in the corneas of the "immune" animals had a longer incubation period on the average, were often of longer duration, and in some instances were more severe than the lesions developing in the control animals. In the case of some animals, also, they showed a greater tendency to recur. The immediate reactions in both the normal and the "immune" animals were entirely comparable and there was no evidence of an accelerated reaction in the test animals. It is concluded that the eye of the syphilitic rabbit does not share to the same extent as other tissues in the general resistant state which develops in that animal during the course of syphilitic infection. Possible explanations for this finding are discussed. PMID- 19870836 TI - INFECTIOUS MYXOMATOSIS OF RABBITS : STUDIES OF A SOLUBLE ANTIGEN ASSOCIATED WITH THE DISEASE. AB - The soluble antigen of myxoma is a heat-labile protein which has an isoelectric point near pH 4.5 and is precipitated from half saturated solutions of ammonium sulfate. It can be partially purified by methods of differential precipitation based on variations in the pH and electrolyte concentration. Rabbits receiving the labile, soluble substance of myxoma develop homologous precipitins and their serum agglutinates elementary bodies of myxoma, provided the dermal pulp from which the bodies are obtained contains the soluble substance; neutralizing antibodies do not appear, however, and the animals are not resistant to infection with the virus of myxoma. Elementary bodies of myxoma appear to have a heat stable agglutinogen that operates when brought in contact with serum from animals recovered from myxoma, but little, if at all, when in contact with anti-soluble substance serum. PMID- 19870837 TI - DETECTION OF THE VIRUS OF POLIOMYELITIS IN THE NOSE AND THROAT AND GASTRO INTESTINAL TRACT OF HUMAN BEINGS AND MONKEYS. AB - Five strains of virus were recovered from nasal washings and feces. Four strains were of human origin, the fifth strain came from a monkey sacrificed at the height of the disease. Of the four human strains the first was isolated from the feces of a 14 year old child 7 days after the onset of illness. The second strain was from the nasal washings of a 6(1/2) year old child, 5 days after the onset of illness. The third and fourth strains were recovered from the same patient, a 2(1/2) year old child, 9 days after the onset of illness. One of these strains was obtained from nasopharyngeal washings and the other from the feces. The single monkey strain was isolated from the upper intestinal segment and appears to be the only instance of its isolation from this source in the literature. We believe that the detection of the virus in the nasal washings of two additional patients during convalescence lends further support to the belief that the virus of poliomyelitis is spread by human contact. Furthermore, the recovery of the virus from the gastro-intestinal tract with as great or greater frequency as from the upper respiratory tract, need not, it appears to us, alter our concept of the mode of entrance of the virus into the body, namely, by way of the upper respiratory tract. If the presence of the virus is conceded, then a consideration of the physiologic passage of nasal and oral secretions into the gastro intestinal tract by reflex swallowing would serve to explain adequately the presence of the virus in those organs. It might even be further predicated that since the gastro-intestinal tract functions as a temporary reservoir for secretions from the upper respiratory tract, the gut should, after a time, contain the virus in higher concentration than any single sample of secretion obtained from the upper respiratory tract by nasal washing. It appears to us that failures to detect the virus in the gastro-intestinal tract are perhaps more indicative of inadequate procedures for its detection than of its absence. The recovery of the virus from the feces 7 and 9 days after the onset of illness takes on added significance. It indicates first, that the virus withstands the gastric acidity which under normal physiological conditions tends to keep gastric contents relatively free of bacteria. It further suggests that improper disposal of feces from patients with poliomyelitis may have serious public health consequences, particularly in smaller communities where inadequate sewage disposal may result in contamination of surrounding beaches or even local water systems. PMID- 19870838 TI - A SPREADING FACTOR IN CERTAIN SNAKE VENOMS AND ITS RELATION TO THEIR MODE OF ACTION. AB - The venom of several species of poisonous snakes acts to spread India ink through the skin as do the spreading factors procurable from certain tissues and elaborated by invasive bacteria. The factor is most abundant in the venom of the Viperidae (rattlesnake) family and relatively scant in the venom of Colubridae proteroglypha (cobra) family, and it is absent from toad venom. Extracts of the supralabial glands of harmless snakes contain only negligible amounts of the factor. Rattlesnake venom heated at 65 degrees to 100 degrees loses a large proportion of its toxicity but retains the ability to spread ink. Rattlesnake venom that has lost its toxicity on standing or on heating markedly enhances the infection produced by bacterial or virus suspension in the rabbit skin. Antivenine serum inactivates both the toxic and spreading factors of venom. PMID- 19870839 TI - MIXED MOLECULES OF HEMOCYANINS FROM TWO DIFFERENT SPECIES. AB - By means of the improved electrophoretic technique it has been possible to study the association products which are formed when mixed and dissociated hemocyanins from two different species are reassociated. Both the dissociation and the reassociation of the hemocyanins have been produced simply by altering the pH of the solutions. Scale method electrophoretic diagrams have been used throughout this investigation. This method has adequately demonstrated its advantages and has permitted exact calculations of the mobility, concentration, and homogeneity of components which were either present in too small an amount or were too nearly similar electrochemically to have been defined by other methods. Evidence has been presented which indicates that a number of mixed hemocyanins have been produced. These mixed hemocyanin molecules contain fractions of the dissociated hemocyanins from two different species. PMID- 19870840 TI - A STUDY OF RICKETTSIAE GROWN ON AGAR TISSUE CULTURES. PMID- 19870841 TI - THE SPECIFICITY OF KERATINS. AB - Kerateine and metakeratin were prepared from wool, chicken feathers and human hair. Chemical analyses revealed that the compounds are closely related. The results of serological studies disclose that species specificity is an individual characteristic of the keratins employed and that the specificity observed is dependent on the redox state of the sulfhydryl groupings in the protein molecule. PMID- 19870842 TI - GROWTH OF THE FOWL CORYZA BODIES IN TISSUE CULTURE AND IN BLOOD AGAR. AB - Evidence is presented that the growth capacity of chick embryo tissue for the fowl coryza bodies is conditioned by a diffusible cellular component which is essential for their multiplication. This growth factor is inactivated at pH 6, but withstands a temperature of 100 degrees C. for 60 minutes. An amount sufficient to promote a normal growth of the specific bodies may be present in tissue culture supernatants long after its content in the tissue is exhausted. Postembryonic tissue (liver and spleen) contains a variable amount of growth factor and is not a satisfactory substitute for the chick embryo. Multiplication of recently isolated fowl coryza bodies is not demonstrable in nutrient media enriched with blood. Experiments with one strain, however, indicate that an adaptation to fluid blood in an agar medium may take place after many generations in tissue culture. The probable bacterial nature of the fowl coryza bodies is discussed on the basis of their cultural requirements. PMID- 19870843 TI - DIFFERENCES IN IMMUNIZATION AND SENSITIZATION IN RABBITS INJECTED WITH RELATIVELY AVIRULENT OR HIGHLY VIRULENT CULTURES OF THE SAME STRAIN (H) OF HEMOLYTIC STREPTOCOCCUS. AB - 1. When a relatively avirulent strain of hemolytic streptococcus was injected into the skin of rabbits a considerable amount of skin sensitivity to streptococcus filtrate developed, and there was scant demonstrable immunity. 2. When the same strain of streptococcus was made highly virulent by repeated passages through rabbits, little sensitization and considerable immunity was produced. 3. Rabbits injected with a virulent culture of hemolytic streptococcus developed agglutinins and precipitins earlier and in larger amounts than animals injected with the avirulent form of the same organism. 4. Increase in virulence of hemolytic streptococci enhances the ability to protect against local infection and increases antibody formation but diminishes the production of sensitization. Avirulent and virulent strains of this microorganism have similar relations. PMID- 19870844 TI - THE RELATIONSHIP OF INFECTING DOSAGE, LEUCOCYTIC RESPONSE, BACTEREMIA, AND EXTENT OF PULMONARY INVOLVEMENT TO THE OUTCOME OF EXPERIMENTAL LOBAR PNEUMONIA IN THE DOG. AB - The present study comprises observations on the course and outcome of experimentally produced Type I pneumococcus lobar pneumonia in dogs. It was found that within certain limits of dosage the outcome of the disease was closely related to the amount of culture and the volume of the starch inoculum employed. The much higher mortality rate resulting from simply increasing the volume of starch in which the pneumococci were suspended, appeared to be due chiefly to the greater area of lung tissue initially involved. Certain striking relationships were observed to exist between the leucocytic response, extent of pulmonary involvement, bacteremia and outcome. Marked changes in the number of white blood cells at end of the first 24 hours of the disease provided more valuable prognostic information than either the blood culture or the size of the lesion. Dogs showing high white counts at this stage seldom succumbed, while absence of leucocytosis and leucopenia were associated with a mortality which increased with the diminishing numbers of circulating white blood cells. Over 90 per cent of the animals with counts of less than 2,000 cells per c. mm. died. The extent of the pulmonary lesion was likewise observed to bear a direct relationship to death rate. With the lesion confined to a single lobe the mortality was only 1 per cent. Spread to other lobes was accompanied by a sharply rising death rate until it reached 98 per cent in dogs with three-fourths the lung field involved. Increasing occurrence of bacteremia paralleled both the decreasing white counts and the extending pulmonary lesions and subsequent to the 24 hour stage of the disease the presence or absence of pneumococci in the blood appears to be of more significance, in relation to outcome, than either of these two other factors. Even in the presence of leucopenia and an extensive lesion the animal might survive provided the blood remained sterile. PMID- 19870845 TI - PHYSIOLOGICAL CONDITIONS EXISTING IN CONNECTIVE TISSUE : I. TTHE METHOD OF INTERSTITIAL SPREAD OF VITAL DYES. AB - The escape of a vital dye from the lymphatics of the ears of living mice and its subsequent movement through normal and pathological connective tissue have been observed at high magnification. The dye first appears outside such channels as bristly, wavy lines of color, which can be bent and twisted by pressure with a micro probe and spring back to their original positions when the pressure is removed, as if the dye were fixed upon or between some tissue elements. Our findings indicate that this is the case, that the bristly lines of color are formed by dye moving between connective tissue fibers or along them. With the onset of mild edema, such as the dye induces secondarily, the bristles disappear, the coloration becoming diffuse and freely movable with the micro probe. When edema is induced before dye is introduced into the lymphatics, the character of its escape is wholly different. It first appears as a colored cloud, freely movable in the edema fluid, the manner of its passage into the tissues being completely changed. In the ears of mice partly dehydrated by bleeding, or in those of dead animals, the bristly or wavy lines were more evident than in normal individuals. It was plain that dehydration did not change the mode of transportation of the dye through the tissue but merely emphasized some of the characteristics of its passage. In animals injected intravenously with large amounts of physiological saline, with result in the presence of more tissue fluid than usual, the colored bristles were seldom seen. It is plain that connective tissue fibers serve indirectly as pathways for the transport of substances of large molecule. We have not been able by the dye method to demonstrate the presence of any free fluid in the normal tissues of the mouse ear. PMID- 19870846 TI - PHYSIOLOGICAL CONDITIONS EXISTING IN CONNECTIVE TISSUE : II. THE STATE OF THE FLUID IN THE INTRADERMAL TISSUE. AB - The interstitial movement of several dyes of widely different chemical constitution and diffusibility, in the connective tissues of the mouse ear, has been observed at high magnification. Dye extension seems to be conditioned by the form and structure of the connective tissue fibers. After escaping from the lymphatics of the ears of living mice, each dye appeared first in the tissues as bristly projections of color. These bent and twisted when pressed upon by a micro probe but sprang back into place when the pressure was removed. The present work and the preceding have shown that the lines of color are formed by dye along or between connective tissue fibers. Intermittent external pressure applied to the tissue, squeezes and bends the fibers together and greatly increases the spread of dye along them. The connective tissue fibers assume an important role in the spread of substances through tissues subjected to pressure changes. The experiments have given evidence of the existence of a tissue matrix in the organ but none of the presence of free interstitial fluid. In tissue subjected to irritant stimuli and in frankly edematous tissue, free fluid is readily demonstrated. When it is present the method of extension of dye is completely changed. Dye appears in the tissues as a diffusely colored cloud which can be freely moved by pressure with a micro probe. The bearing of this evidence upon the condition of interstitial fluid and the nature of the interstitial spaces is discussed. PMID- 19870847 TI - QUANTITATIVE RELATIONSHIPS BETWEEN THE IMMUNIZING DOSE OF EPIDEMIC INFLUENZA VIRUS AND THE RESULTANT IMMUNITY. AB - A direct proportion exists between the concentration of epidemic influenza virus used for intraperitoneal immunization of mice and the degree of immunity to intranasal infection which develops. Mice vaccinated with virus of a given strength resist infection with virus of the same concentration but not more. An irreducible minimum exists since mice vaccinated with less than ten intranasal lethal doses do not develop sufficient immunity to overcome intranasal infection with virus of the same strength. The fact that there exists a limiting threshold for the degree of immunity which a certain strength of virus will induce indicates that the virus does not multiply after intraperitoneal inoculations. In ferrets a state of partial immunity is induced as a result of subcutaneous vaccination with active influenza virus. Vaccination with doses containing 100 or more intranasal infectious units is required for the production of circulating antibodies, protection of the animals from pulmonary involvement, and modification of the severity of the disease. On the other hand, intranasal inoculation with one infectious unit results in a firm, immediate immunity, although the duration of immunity may bear a relation to the severity of the original infection and consequently to the size of the infecting dose. Ferrets in a state of partial immunity resulting from subcutaneous vaccination, or from the waning of a firm immunity following infection, respond to intranasal inoculation of influenza virus with an accelerated production of neutralizing antibodies. The antibody titer under these conditions reaches a much higher level than occurs following a primary infection. Fully immune animals, however, show no further antibody response to a second inoculation. PMID- 19870848 TI - HEREDITARY BRACHYDACTYLIA AND ALLIED ABNORMALITIES IN THE RABBIT. AB - A series of deformities in the rabbit ranging from brachydactylia to acheiropodia have been described. Experimental breeding demonstrated that the occurrence of the deformities was determined by simple recessive hereditary factors and that the various types were genetically related and were not distinct hereditary entities. Embryological investigation showed the first abnormal change was a dilatation of blood vessels in affected buds. This was followed by hemorrhage and necrosis of the parts involved. Sloughing subsequently occurred, and the deformity was completely expressed by the 25th day of fetal life. PMID- 19870849 TI - HEMOGLOBIN PRODUCTION IN ANEMIA LIMITED BY LOW PROTEIN INTAKE : INFLUENCE OF IRON INTAKE, PROTEIN SUPPLEMENTS AND FASTING. AB - A low protein intake will cause limited hemoglobin production in standard anemic dogs. It appears that the dog on a limited protein intake is unable to produce the usual amount of globin and therefore of hemoglobin even in the presence of a large excess of iron. Iron given by mouth or by vein shows the same result-the dog made anemic by blood withdrawal cannot produce the expected new hemoglobin related to the iron intake when the protein intake is held at low levels. These dogs can be kept in perfect health and weight equilibrium during these long periods of limited diet intake and anemia. Under the stress of protein limitation the proteins of salmon muscle, banana and carrot are well utilized and it requires only 7 to 8 gm. of these food proteins to produce 1 gm. of new hemoglobin. These experiments show clearly that the iron content of liver is not wholly responsible for its potency in anemia due to hemorrhage. PMID- 19870850 TI - A VIRUS DISEASE OF CATS, PRINCIPALLY CHARACTERIZED BY ALEUCOCYTOSIS, ENTERIC LESIONS AND THE PRESENCE OF INTRANUCLEAR INCLUSION BODIES. AB - An acute, highly fatal epizootic disease of cats is described, which can be recognized by a fulminating and extreme leucopenia involving all types of white blood cells, aplasia of the bone marrow, including both the granulocytic and the erythrocytic series and occasionally the megakaryocytes, aplasia of lymphoid tissue, and characteristic intranuclear inclusion bodies in the cells of the intestinal mucosa and in certain cells of the spleen, lymph nodes and bone marrow. The infection has been induced in healthy cats by means of bacteria-free filtrates of emulsions of the spleen of infected animals. Collateral evidence supports the conclusion that the disease is due to a virus. The pathogenicity of the infectious agent has proved thus far to be strictly limited to the natural host. PMID- 19870851 TI - STUDIES ON ANTIBACTERIAL IMMUNITY INDUCED BY ARTIFICIAL ANTIGENS : I. IMMUNITY TO EXPERIMENTAL PNEUMOCOCCAL INFECTION WITH AN ANTIGEN CONTAINING CELLOBIURONIC ACID. AB - 1. An artificial antigen containing the azobenzyl glycoside of cellobiuronic acid gives rise in rabbits to antibodies which: (a) give the Neufeld reaction and agglutinate Type III pneumococci, (b) confer passive protection on mice against infection with Types II, III, and VIII pneumococci. 2. Rabbits immunized with the artificial cellobiuronic acid antigen acquire active resistance to infection with virulent Type III pneumococci. 3. The antibodies evoked by an antigen containing the azobenzyl glycoside of cellobiose exhibit none of these phenomena. PMID- 19870852 TI - ARTIFICIAL MAINTENANCE MEDIA FOR CELL AND ORGAN CULTIVATION : I. THE CULTIVATION OF FIBROBLASTS IN ARTIFICIAL AND SERUMLESS MEDIA. AB - Several media designed for maintaining the life of cells and organs outside the body have been described. Cultures from a pure strain of fibroblasts have been maintained in these media in vital condition and with little or no proliferation for periods varying from 43 to 56 days. One of these media is very simple, inexpensive, and easy to prepare; and one is serumless. PMID- 19870853 TI - COMPLEMENT FIXATION IN HUMAN MALARIA WITH AN ANTIGEN PREPARED FROM THE MONKEY PARASITE PLASMODIUM KNOWLESI. AB - In the studies of complement fixation described in this paper, the antigens were prepared from (a) normal monkey red cells, (b) parasitized red cells of monkeys dying with Plasmodium knowlesi infection, (c) the spleens of monkeys dying with Plasmodium knowlesi infection; the sera came from (a) normal human beings, (b) patients with syphilis, (c) patients with paresis who were receiving malaria therapy with Plasmodium knowlesi, Plasmodium vivax, or Plasmodium falciparum, and (d) patients with malaria alone. The malarial antigens gave negative complement fixation reactions with 70 to 80 per cent of the luetic and normal sera and weak or doubtful reactions with the remaining 20 to 30 per cent. With the exception of one antigen prepared from spleen, there was no evidence that the malarial antigens were more reactive with Wassermann-positive than with Wassermann negative sera. Some human sera give weak complement fixation with antigens prepared from normal monkey erythrocytes, and the percentage of these positive reactions is slightly higher with malarial sera than with normal or luetic sera. The most sensitive and specific malarial antigen was prepared from dried parasitized red cells by extraction with saline, freezing, and thawing. This P. knowlesi antigen gives strong complement fixation with malarial sera from human beings infected with P. knowlesi, P. vivax, or P. falciparum. The titer of complement-fixing antibodies reaches a maximum about 1 month after the beginning of the acute infection. At this time all of the P. knowlesi sera tested were positive. After 4 months the reaction diminishes rapidly in titer but may remain positive for 12 months or longer. With P. knowlesi infections in man, the complement fixation reaction remains positive for some time after the infection has apparently disappeared as judged by daily smears and inoculation of monkeys with the blood. The complement fixation reaction in malaria is group-specific rather than species-specific. Sera from patients infected with P. vivax or P. falciparum react in the same way with the P. knowlesi antigen as the homologous sera. Absorption of malarial human sera with normal monkey erythrocytes does not remove the immune bodies which fix complement with malarial antigens. PMID- 19870854 TI - A COMPARISON OF VIRUS-INDUCED RABBIT TUMORS WITH THE TUMORS OF UNKNOWN CAUSE ELICITED BY TARRING. AB - Tarring the ears of rabbits of one sort with a single kind of tar evoked epidermal tumors of a few sharply defined types, namely ordinary papillomas, carcinoids, carcinomas, and "frill horns." These last, relatively infrequent, are now recognized for the first time. The carcinoids have proved to be the expression of a spurious malignancy of papillomas, resulting from intercurrent influences, and they were wholly dependent upon these for their threatening aspect and behavior. Chief amongst such influences was continued tarring. It had the effect of establishing the papillomas, stimulated their proliferation, complicated their morphology, and rendered some of them disorderly, aggressive, and anaplastic. It brought all of the tissues of the ears into an excitable state, and often this state endured long after the skin had apparently returned to normal. The characters of the papilloma-carcinoids and of the frill horns were so different and distinctive as to imply the action of differing, specific causes. The papillomas were very like those induced with the Shope virus, and hence a point-to-point comparison was made of their manifestations, including the derivation of carcinomas from them. This comparison demonstrated that the unknown cause of the tar papillomas provoked neoplastic phenomena which were identical in all essential respects with those due to the virus. To suppose, for experimental purposes, that the papillomas which tarring elicits are caused by a virus rendered pathogenic by this procedure, is to demand least of the unknown. Yet it does not follow that they must be due to a virus. PMID- 19870855 TI - ANTIGENIC PROPERTIES OF THE TYPE-SPECIFIC SUBSTANCE DERIVED FROM GROUP A HEMOLYTIC STREPTOCOCCI. AB - 1. A substance extracted from group A hemolytic streptococcus is described, which induces active immunity in mice, and in rabbits gives rise to precipitins and to protective antibodies passively transferable to mice. 2. The active immunity in mice is principally type-specific, but some degree of non-type-specific immunity is also developed. The passively transferable protective antibodies are type specific with only a slight suggestion of non-type specificity. In the precipitin test, the rabbit immune sera give both type-specific and non-type-specific reactions which have not been fully analyzed serologically. 3. Substances contained in the extract absorb the protective antibodies from the serum of rabbits immunized with whole hemolytic streptococci. 4. The most satisfactory method of extraction so far developed is fully described. Chemical tests on the material are consistent with the presence of protein and nucleic acid. 5. The type-specific M substance, prepared as previously described, was compared in some of its antigenic properties with the above mentioned substance. It was found capable of inducing active immunity in mice and of absorbing protective antibody from anti-bacterial immune serum in a manner qualitatively similar to that obtained with the preparations made by the newer methods. PMID- 19870856 TI - UTERINE ADENOMATA IN THE RABBIT : II. HOMOLOGOUS TRANSPLANTATION EXPERIMENTS. AB - The behavior of a transplanted adenocarcinoma of the uterus of a rabbit has been studied through 12 serial generations in the anterior chamber of the eye and 6 serial generations in the testicle. The transplanted tumor is characterized by slow growth which is at first expansive and later invasive, by an ability to form more or less differentiated structures in response to different environmental conditions and by late metastasis. The endocrinological changes that distinguish animals bearing the spontaneous tumor do not occur in animals bearing the transplanted tumor. Various experiments were undertaken in an attempt to discover the nature of the factors determining the characteristics of the spontaneous and of the transplanted tumor. It was found that successful transplantation was followed by a phase during which animals were refractory to reinoculation. The results of transplantation into the eyes of animals with spontaneous tumors suggested the existence of a similar phase during the early development of the tumor but the number of observations was not sufficiently numerous to warrant definite conclusions. PMID- 19870857 TI - ORGAN WORK AND ORGAN WEIGHT. AB - 1. The ratios between the rates of growth of the body and of the heart, kidneys, and liver are approximately uniform between 40 gm. body weight and the body weight at maturity in the albino rat. The male and female hearts grow at 0.75 times the rate of growth of the body, the male kidneys at 0.717 times, the female kidneys at 0.648 times, and the liver at 0.838 times the rate of growth of the body as a whole. 2. Formulas for the prediction of organ weight from body weight were derived from the data on 1591 albino rats kept under constant conditions. 3. A series of experiments in which dietetic and metabolic variables were introduced into otherwise constant conditions showed that the heart weight was not affected by diet, and that both kidney weight and weight of liver protein (used as a measure of effective liver size) varied in the direction of change in the protein content of the diet. Decrease in rate of metabolism induced by thyroidectomy and increase in metabolism following the administration of thyroxin led to a corresponding fall and rise of heart, kidney, and liver protein weight. These results were confirmed in experiments on fasted rats with the exception that under these conditions thyroidectomy did not appreciably decrease liver protein weight relatively to fasted controls. Increase in organ metabolism due to dinitrophenol had no effect on organ weight. 4. When experimental changes alter the composition of the body with respect to fat or water, the comparison of experimental and control organ weights in terms of any one function of body weight is fallacious. 5. Conditions that change kidney weight usually change liver protein weight in the same direction and roughly to the same degree. The possible meaning of two exceptions to this rule is discussed. 6. The observations made are regarded as supporting the hypothesis that, after weaning, change in the weight of the heart, kidney, and liver protein is determined mainly by change in the amount of work done by these organs. PMID- 19870858 TI - NEPHRITIS AND ITS INFLUENCE UPON HEMOGLOBIN PRODUCTION IN EXPERIMENTAL ANEMIA. AB - Spontaneous glomerulonephritis develops not infrequently (11 per cent incidence) in the anemia colony. The course of the nephritis is insidious and usually extends over several years but ends in uremia, often with terminal bronchopneumonia. Hemoglobin production in these standard anemic dogs is well established as related to various standard food factors. These tests are summarized in the tables above to show the changes that appear year by year in the life of each dog. Nephritis causes little or no change in hemoglobin production in anemic dogs in the early stages of the disease. In the late stages of nephritis there may be no change or moderate changes in hemoglobin production in these anemic dogs. The average is 70 per cent of normal hemoglobin production in advanced nephritis. It seems unlikely that this degree of impairment of hemoglobin production in nephritis would result in spontaneous anemia in the dog. PMID- 19870859 TI - THE ANTIBODY RESPONSE TO SWINE INFLUENZA. AB - Antibodies that neutralize swine influenza virus became detectible in the serum of swine on the 6th or 7th day after infection with swine influenza. Their appearance corresponded rather closely with clinical recovery. In swine with the milder filtrate disease, neutralizing antibodies did not appear until sometime between the 7th and 10th days. The maximum antibody titers ranged from 1:60 to 1:160 and were attained on from the 14th to the 27th days after infection. PMID- 19870860 TI - VITAMIN C IN RELATION TO EXPERIMENTAL POLIOMYELITIS : WITH INCIDENTAL OBSERVATIONS ON CERTAIN MANIFESTATIONS IN MACACUS RHESUS MONKEYS ON A SCORBUTIC DIET. AB - In the experiments reported in the present communication it was found that vitamin C, both natural and synthetic preparations, had no effect on the course of experimental poliomyelitis induced by nasal instillation of the virus. The objection cannot be raised that too large an amount of virus was used, since recent studies (3) on the fate of the nasally instilled virus indicated that all but an undetectable amount of it is swallowed and disappears from the nasal mucosa within 3 hours or less, and that none is demonstrable in the central nervous system before the 3rd day. Vitamin C administration was begun immediately after the instillation of virus and if it were capable of exerting any effect on the virus or the tissues it could have done so even before multiplication of virus had begun. Monkeys whose store of vitamin C was depleted reacted in the same way as those receiving an adequate diet. There is no apparent explanation for the difference between these results and those reported earlier by Jungeblut (1,2). During the present investigation it was found that monkeys on a scorbutic diet died of spontaneous acute infections, chiefly pneumonia and enterocolitis, while their mates receiving an adequate diet remained well. The surviving monkeys on the scorbutic diet developed the osseous and other changes of human scurvy, and the vitamin C used in this study was shown to produce healing and calcification in the bones as well as to check the edema and hemorrhagic diathesis. PMID- 19870861 TI - THE SOLUBLE MALARIAL ANTIGEN IN THE SERUM OF MONKEYS INFECTED WITH PLASMODIUM KNOWLESI. AB - A soluble malarial antigen which fixes complement with immune serum is found in the serum of monkeys infected with Plasmodium knowlesi. The amount of antigen in the serum is related to the parasite count during the acute phase of the infection. The antigen is not excreted in the urine. Intravenous injection into normal monkeys of serum containing the antigen stimulates the production of specific complement-fixing antibodies which react with antigens extracted from parasitized cells, as well as with the antigen present in serum obtained during the acute phase of infection. Monkeys immunized with serum antigen apparently possess very little or no immunity to infection. The soluble malarial antigen is labile to acids and alkalies, is not destroyed by a temperature of 56 degrees C., and is precipitated, for the most part, in the albumin fraction of the serum by ammonium sulfate. PMID- 19870862 TI - EFFECT OF PREGNANCY UPON THE IMMUNITY OF MICE VACCINATED AGAINST ST. LOUIS ENCEPHALITIS VIRUS. AB - 1. Virgin and pregnant Swiss mice are equally susceptible to intracerebral inoculation of St. Louis encephalitis virus. 2. Following subcutaneous vaccination with the St. Louis virus, the great majority of virgin Swiss mice become immune to subsequent intracerebral injection of 10,000 M.L.D. of the virus. 3. The majority of mice vaccinated during pregnancy do not become immune to even as little as 500 intracerebral M.L.D. of the virus. The depression of the ability to acquire immunity against the virus is most marked when the vaccination is carried out late in pregnancy, but it is also demonstrable when the mice are vaccinated early in the gestation period and during the first 2 weeks postpartum. At 7 weeks postpartum the response to vaccination is more nearly like that of virgin mice. 4. Pregnancy not only interferes with the development of acquired immunity but it also diminishes a previously established immunity. 5. Offspring of the mice vaccinated during pregnancy are not immune to 100 M.L.D. of virus. PMID- 19870863 TI - THE EFFECTS OF ANAPHYLAXIS, AND OF HISTAMINE, UPON THE CORONARY ARTERIES IN THE ISOLATED HEART. AB - Anaphylaxis in the isolated, perfused hearts of cats has been shown to be accompanied by a considerable, though transient, increase in coronary flow. This result is contrasted with that observed in the hearts of guinea pigs and rabbits in which the coronary arteries are constricted during anaphylaxis. Attention is directed to the fact that, in the hearts of these three species, the effects of anaphylaxis and of histamine are qualitatively parallel. The characteristic anaphylactic response in the isolated hearts of guinea pigs has been evoked: (a) in the organs removed from immune animals, (b) by each of two antigens (horse serum and egg albumen) under conditions of double sensitization, and (c) upon exposure of the hearts of passively sensitized animals to the type-specific polysaccharide of the pneumococcus. It is evident that, among the effects of anaphylaxis upon smooth muscle in various organs, there must be considered that upon the coronary arteries. PMID- 19870864 TI - STUDIES ON THE MECHANISM OF IMMUNITY IN TUBERCULOSIS : THE ROLE OF EXTRACELLULAR FACTORS AND LOCAL IMMUNITY IN THE FIXATION AND INHIBITION OF GROWTH OF TUBERCLE BACILLI. AB - 1. The fate of bacilli of reinfection at the portal of entry and in metastatic foci, and also the associated host responses, are essentially similar in rabbits and guinea pigs. 2. However, in the guinea pig tubercle bacilli of reinfection are more effectively fixed at the portal of entry than in the rabbit. 3. The guinea pig fixes at the site of reinfection unrelated substances, such as trypan blue and agar particles, more effectively than the rabbit. 4. At the site of a local non-specific inflammation precipitins from the circulating blood accumulate in higher concentration in tuberculous guinea pigs than in tuberculous rabbits. 5. These differing fixing capacities of the two species are associated with differences of extracellular character in the inflammation resulting from reinfection. (a) In the guinea pig, whose tissues are highly sensitized and greatly injured by the tubercle bacillus, the lymphatics adjoining the site of reinfection become thrombosed. In the rabbit whose tissues are moderately sensitized and less injured by the tubercle bacillus the corresponding lymphatics remain open. (b) In the guinea pig the fibrinous network at the site of inflammation forms a fine sieve-like structure. In the rabbit this network forms a coarse sieve-like barrier. 6. In rabbits and guinea pigs primarily infected, the destruction of tubercle bacilli takes place first and most extensively at the portal of entry. At this time they are less effectively destroyed in the nearest metastatic foci. Simultaneously they are still growing without hinderance in such foci in remote internal organs. 7. The cell-free body fluids of normal animals support the growth of tubercle bacilli in vivo. The body fluids of tuberculous animals under the same conditions are bacteriostatic for this microorganism. 8. Tubercle bacilli often multiply by preliminary subdivision into non-acid-fast granules, from which the acid-fast rods sprout. This confirms the work of Kahn. PMID- 19870865 TI - STUDIES ON THE MECHANISM OF IMMUNITY IN TUBERCULOSIS : THE MOBILIZATION OF MONONUCLEAR PHAGOCYTES IN NORMAL AND IMMUNIZED ANIMALS AND THEIR RELATIVE CAPACITIES FOR DIVISION AND PHAGOCYTOSIS. AB - 1. Tuberculous and vaccinated rabbits and guinea pigs mobilize mononuclear phagocytes at the site of a non-specific inflammation with greater rapidity than do normal animals, just as they respond to tubercle bacilli. 2. The succession of cells that characterizes inflammation in general is accelerated in allergic rabbits and guinea pigs in response to non specific irritants. 3. The pH at the site of reinfection with tubercie bacffli in immun ized rabbits and guinea pigs and at the site of a non-specific inflammation in the latter is slightly lower than in a similar site in a normal animal. 4. No constant relation was found between the mobifization of mononuclears and the hydrogen ion concentration at the site of inflammation. 5. The rate of mitotic and amitotic division of mononuclears in allergic rabbits and guinea pigs in response to non-specific irritants is greater than in normal animals. 6. Mononuclears derived from actively tuberculous or vaccinated guinea pigs exhibit greater in vitro phagocytic capacity for carbon particles than mononuclears obtained from normal animals. 7. Mononuclears of tuberculous rabbits ingest more staphylococci than the phagocytes of the same type originating from normal animals. 8. Mononuclears originating from actively tuberculous rabbits and guinea pigs exhibit greater in vitro phagocytic capacity for tuberde bacilli than mononuclears obtained from normal animals. 9. The enhancement of the phagocytic capacity for tubercie bacilli afforded mononuclears by vaccination with a bacillus of low virulence is lower, and of questionable significance. 10. The increased phagocytic activity of mononuclears derived from tuberculous or vaccinated rabbits and guinea pigs for tubercie bacilli and for non-specific particulate matter occurs in media containing sera derived from normal and from tuberculous individuals. 11. The more rapid mobilization of mononuclears by immunized animals in response to specific as well as non-specific irritants is associated with their increased physiological activity. The significance of this enhanced activity conferred by the tuberculous process on the mesenchyme cells is discussed in relation to the mechanism of immunity to tuberculosis and other phenomena. PMID- 19870866 TI - THE MODE OF ACTION OF SULFANILAMIDE ON STREPTOCOCCUS. II. AB - The precise mode of therapeutic action of sulfanilamide on streptococcus can be arrived at only by considering the sum total of factors that inhibit or favor the natural growth of the microorganism under the experimental conditions that obtain, whether in vivo or in vitro. Too sweeping conclusions have hitherto been drawn from the study of a single variable factor, such as an unfavorable temperature or the absence or presence of peptone. We have attempted here to analyze the factors that have hitherto been recognized and some new ones, but particularly the relationship of these factors to one another. The result obtained on adding sulfanilamide to the streptococcus in the test tube is usually bacteriostasis and not complete destruction of even small numbers of bacteria. This is on the condition that the suspending medium is a favorable one for the growth of the microorganism; the more growth-promoting the medium is the less the bacteriostasis. If, on the other hand, the medium is too poor, or one that in itself inhibits growth, the addition of sulfanilamide may lead to sterilization of the culture. The conditions for growth of the streptococcus in the body of the rabbit or mouse, depend on the strain of bacteria used, but are on the whole favorable. Defence, however, in the form of phagocytosis by both polymorphonuclear and by mononuclear cells is attempted even in the susceptible animal. When sulfanilamide is used to treat such an animal, or when sulfanilamide grown (inhibited) streptococci are employed, phagocytosis is pronounced, whether studied in the test tube or in the animal body. In the rabbit the delay by sulfanilamide and resultant increased phagocytosis by polymorphonuclears allows mononuclear cells to accumulate and recovery may result. Sulfanilamide not only does not completely destroy the streptococcus but does not even impair its innate virulence. It acts upon the streptococcus not only by inhibiting growth but by a temporary inhibition of hemotoxin formation, but only under certain conditions. The drug does not neutralize hemotoxin already formed. No significant effect of sulfanilamide on the formation of leucocidin or fibrinolysin by streptococcus has been evident in our experiments. Sulfanilamide differs in one important respect from other drugs that are destructive either in the test tube or actually in the body, for protozoa and bacteria. Protozoa fix or adsorb arsenicals and acriflavine that kill them variably in vitro and in vivo. Streptococci fix both gentian violet and acriflavine, which dyes have marked destructive action in the test tube but are less effective in vivo. Sulfanilamide is not diminished at all by contact in vitro with large masses of streptococci, nor does the action of this drug render the microorganism more capable than untreated cocci to adsorb gentian violet or acriflavine, or to be destroyed by these highly bactericidal substances. PMID- 19870867 TI - CAUSES OF THE CESSATION OF GROWTH OF FIBROBLASTS CULTIVATED IN EMBRYO JUICE. AB - Experiments designed to ascertain the reason for the cessation of growth of heart fibroblasts when they are cultivated in a plasma coagulum with embryo juice as nutrient fluid have shown that it is due, first, to the gradual removal of serum from the coagulum, and second, to an insufficient supply of embryo juice. In a medium containing embryo extract at 66 per cent concentration and serum at 8 per cent concentration, growth continued until the entire coagulum in a 3(1/2) cm. flask was covered with tissue. The serum is needed to furnish additional nutriment, and also to prevent digestion of the coagulum. PMID- 19870868 TI - THE ENHANCING EFFECT OF AZOPROTEINS ON THE LESIONS PRODUCED BY VACCINE VIRUS, THE SHOPE FIBROMA VIRUS, AND THE AGENT TRANSMITTING CHICKEN TUMOR I. AB - It is known that azoprotein solutions, like testicular extracts, possess the property of causing particles to spread through the dermis. The present work shows that azoproteins exhibit, like testicular extract, the power to increase the size of virus lesions in the skin of rabbits, and the size of tumors in chickens. The results indicate that the extent of the lesion is roughly proportional to the spreading power of the solution. This suggests that the spread of the infective material, over a larger area of skin, is directly responsible for the enhancing effect. The production of extensive lesions by means of spreading agents may have a practical value when large amounts of working material are needed. PMID- 19870869 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : IX. THE EFFECT ON BLOOD PRESSURE OF CONSTRICTION OF THE ABDOMINAL AORTA ABOVE AND BELOW THE SITE OF ORIGIN OF BOTH MAIN RENAL ARTERIES. AB - Constriction of the aorta just above the origin of both main renal arteries invariably resulted in elevation of the carotid systolic and carotid mean pressure. The hypertension was not immediate, but developed in about the same time as after constriction of the main renal arteries (3). Constriction of the aorta just below the origin of both main renal arteries had no significant effect on the carotid systolic or carotid mean pressure. Since these results were first reported (1), Rytand (88, 89) has shown by an indirect method, namely, the demonstration of the development of cardiac hypertrophy, that hypertension in the upper part of the body can be produced in the rat by constriction of the aorta just above the origin of both main renal arteries. The immediate effect of constriction of the aorta either below or above the main renal arteries is a fall of blood pressure (femoral mean pressure) below the site of the clamp, the extent of the fall being directly dependent upon the degree of constriction of the aorta. Of particular interest is the eventual elevation of the femoral mean pressure above the normal in some animals with the aorta constricted or even occluded above the origin of the main renal arteries. This was most pronounced and persistent in those animals in which, in addition, the aorta below the origin of the renal arteries, and, in some animals, the main renal arteries, also were constricted. The most important factors which determined this elevation of blood pressure in the lower part of the body were probably increased flow of blood into the vascular bed below the clamp and peripheral vasoconstriction of renal and humoral origin, as in the case of the hypertension produced by constriction of the main renal arteries alone (2-86). Although elevation of the carotid systolic or carotid mean pressure occurred invariably within 24 to 48 hours after the constriction of the aorta above the site of origin of both main renal arteries, yet there was a tendency, after a variable period, for the elevated blood pressure to become lower or even to drop to the original level. Increased constriction, and finally occlusion of the aorta, above the origin of the main renal arteries, and even constriction or occlusion of the aorta below the renal arteries, in addition, failed to induce hypertension that persisted for a long time at a high level. In order to produce this effect, it was necessary to constrict the main renal arteries as well. The possible explanation of the failure of the hypertension to persist for a long time after constriction of the aorta alone, is that the initial ischemia of the kidneys disappeared due to the improvement of the blood flow through the kidneys as a result of (a) the increase of the natural accessory circulation to the kidneys; (b) the increased blood pressure above the site of the clamp and consequent increased flow of blood into the part of the aorta below the clamp; (c) increased pressure below the site of the clamp due, in great part, to peripheral vasoconstriction, and in part to the increased inflow of blood into the lower part of the body through the aorta and collateral channels. For the dog, this method is not necessary for the production of persistent hypertension. Constriction of the main renal arteries is easily performed and is effective for the production of generalized hypertension (2-11). However, constriction of the aorta in addition to constriction of the renal arteries results in greatly elevated persistent hypertension. Constriction of the aorta alone above the origin of the main renal arteries would be useful in the dog only for the production of relatively short periods of hypertension in the upper part of the body. For small animals it may be a more effective and useful method. In the dog, the only technical difficulty encountered was the erosion of the wall of the aorta by the clamp. This may not occur in small animals. In previous studies (2-11) that have dealt with the constriction of the main renal arteries, this accident rarely occurred. When the constriction of the aorta above the origin of the main renal arteries was of moderate degree, or was gradually made very great, the resultant hypertension was not accompanied by impairment of renal excretory function, as determined by urea clearance or by the quantity of urea, creatinine or non-protein nitrogen in the blood, the benign phase of hypertension (3). When the constriction of the aorta was suddenly made very great, impairment of the renal excretory function usually followed, and the animal developed fatal convulsive uremia and characteristic vascular lesions, the malignant phase of hypertension (9). These facts, are all indicative of the renal origin of the hypertension which results from the constriction of the aorta just above the origin of both main renal arteries. Hypertension did not persist for a sufficiently long time to permit any conclusive comparison between the effect of the high and low pressures on the structure of the vascular system, above and below the site of the clamp, respectively. During the period of survival of these animals, no significant differences were observed between the appearance of the vascular system of the upper part of the body and that of the lower part of the body, and significant cardiac hypertrophy did not develop. In the aorta and large arteries, intimal arteriosclerosis was not observed. In the aorta of one old animal several small plaques of calcification were found in the media, but these were present in the portion of the aorta below, as well as above the clamp, and they were no larger or more abundant than were observed in some old dogs with normal blood pressure. Dogs 3-50 and 3-83, that are still alive, with very high blood pressure above the site of the aortic clamps, and relatively low pressure (though greater than normal) below the site of the aortic clamps, will be valuable for the determination of possible differences between the effects of the two levels of blood pressure in the large and small blood vessels. In these dogs also, it will be possible to determine the effect of the persistently high blood pressure on the myocardium. The possible application of the results of this study to the problem of the pathogenesis of human eclampsia is mentioned here for consideration. Since this condition occurs in pregnancy only at a time when the uterus is greatly enlarged, it is at least possible that the mass may press on the aorta or both main renal arteries sufficiently to produce renal ischemia. The suddenness with which the uremic convulsive phase of eclampsia develops is in keeping with this idea. In the dog, an aggravating effect of pregnancy on an already established hypertension has not been noted. As a matter of fact, most of the hypertensive dogs that have become pregnant, have shown a slight or moderate fall, rather than an increased rise of pressure. Since the dog stands with the body in a horizontal position, and does not lie on its back, pressure of the pregnant uterus on the aorta and blood vessels is less than in human beings who stand erect and frequently lie on their backs. The soundness of this suggestion could be tested by placing pregnant women, in the early stage of eclampsia, in a position which could relieve possible pressure on the aorta and main renal arteries. A possible explanation of the fall of pressure in the pregnant hypertensive dogs is the compensatory effect of the normal kidneys of the pups, as in the case of an animal with one main renal artery constricted and the other kidney normal. As has been shown (3, 31, 72), the presence of one normal kidney in an animal hypertensive due to constriction of the other main renal artery, results, after a variable period, in a return of the blood pressure to normal. How the normal kidney acts to produce this effect is not known. PMID- 19870870 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : II. PATHOGENESIS OF THE DISEASE IN THE GUINEA PIG. AB - After inoculation with equine encephalomyelitis virus by various routes, guinea pigs were sacrificed at early stages, before symptoms were apparent. The brains were studied histologically, with serial sections; all lesions were noted, and subjected to topographical analysis. Nine cases are presented in detail. With any given mode of inoculation the distribution of lesions varied very widely from one instance to another. In some cases, affected regions bore a striking and definite anatomical relationship to each other. These distributions can be explained only by the assumption that the anatomical pathways played some role in the spread of the virus. In other instances lesions were present in areas, the anatomical connections of which were entirely normal. Attention is called to the frequency of lesions in the neocortex, with intact subcortical centers. Such distribution is held to render nerve spread extremely improbable. The only satisfactory explanation of such random distributions is by direct passage of virus from the blood stream into the brain tissue. There is no histological difference between lesions which result from blood spread and those resulting from nerve spread. PMID- 19870871 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : III. INTRAOCULAR INFECTION WITH FIXED VIRUS IN THE GUINEA PIG. AB - The behavior of a fixed strain of Eastern equine encephalomyelitis virus was studied in guinea pigs after intraocular inoculation. Such inoculation concerns the central and not the peripheral nervous system. The susceptibility to intraocular injection lies midway between the highly virulent intracerebral and the quite avirulent peripheral routes. The virus must act for 10 to 13 hours in order to induce a fatal infection. Removal of the inoculated eyeball before this interval almost always prevents fatality although it may allow immunity to develop. The virus, at suitable intervals after injection into the eye, may be recovered from successive and appropriate optic centers before it is demonstrable in non-optic portions. Approximately 24 hours are required for the virus to reach a significant concentration in the contralateral geniculate body, 36 hours in the contralateral visual cortex. Significant amounts of virus may be present in the optic chiasm and tract prior to involvement of the higher centers. Virus placed in contact with the retina produces an insignificant, essentially non-specific reaction comparable to that produced at the site of direct intracerebral inoculation. In the retina there is no ganglion cell necrosis unless there is a complicating intraocular infection. In the cerebral visual centers the first reaction is inflammatory and interstitial, and may appear in the lateral geniculate body as early as 24 hours after injection. Neuronal necrosis is not the primary action of the virus on the nervous system in these experiments. The distribution of lesions in the brain is in excellent agreement with the method of direct testing for virus content, and is far more accurate than the latter. The virus in its primary distribution through the nervous system follows the nerve pathways of the optic system. This occurs within the central nervous system, where presumably there is first an involvement of the nerve cell body and then a spread along the cell process or axone. PMID- 19870872 TI - ON THE SEROLOGICAL SPECIFICITY OF PEPTIDES. III. AB - Experiments are described dealing with immune sera to pentapeptides and peptide amides. Absorption and inhibition tests gave no indication of the presence in the immune sera of special antibodies for portions of a peptide molecule but the antibodies appeared to be specific for an entire pentapeptide even though the sera contained qualitatively different fractions. Marked disparity was found between the reactions of peptides and corresponding amides indicating differences between acid and other polar groups in their influence on serological specificity. PMID- 19870873 TI - BLOOD PLASMA PROTEIN PRODUCTION AS INFLUENCED BY AMINO ACIDS : CYSTINE EMERGES AS A KEY AMINO ACID UNDER FIXED CONDITIONS. AB - When blood plasma proteins are depleted by bleeding with return of the washed red blood cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal low protein diet. These dogs are clinically normal. By the introduction of variables into their standardized existence insight into the formation of plasma proteins can be obtained. The liver basal diet maintains health in such hypoproteinemic dogs during periods as long as a year. 17 to 27 per cent of its protein content (entirely liver protein) is presumably converted into plasma protein. Gelatin alone added to the liver basal diet causes very little if any extra plasma protein production. The addition to gelatin of cystine, or tyrosine, or tryptophane, or of both tyrosine and tryptophane has little or no effect on its potency for plasma protein production. When gelatin is supplemented by cystine and either tryptophane or tyrosine, 25 to 40 per cent of the protein content of the combination is converted into plasma protein-an efficiency equaling that of any protein hitherto tested. Preliminary experiments indicate that methionine cannot substitute for cystine nor can phenylalanine substitute for tyrosine in the efficient combination of gelatin plus cystine plus tyrosine. Laked red blood cells given by vein afford little or no material for plasma protein formation. When the reserve stores of plasma protein building material are exhausted the dog can form little if any plasma protein during protein-free diet periods. PMID- 19870874 TI - RADIOACTIVE IRON AND ITS METABOLISM IN ANEMIA : ITS ABSORPTION, TRANSPORTATION, AND UTILIZATION. AB - Artificially produced radioactive iron is an extremely sensitive agent for use in following iron in the course of its changes in body metabolism, lending itself to studies of absorption, transport, exchange, mobilization, and excretion. The need of the body for iron in some manner determines the absorption of this element. In the normal dog when there is no need for the element, it is absorbed in negligible amounts. In the anemic animal iron is quite promptly assimilated. The plasma is clearly the means of transport of iron from the gastrointestinal tract to its point of mobilization for fabrication into hemoglobin. The speed of absorption and transfer of iron to the red cell is spectacular. The importance of the liver and bone marrow in iron metabolism is confirmed. PMID- 19870875 TI - ANTIGEN-ANTIBODY REACTIONS BETWEEN LAYERS ADSORBED ON BUILT UP STEARATE FILMS. AB - By adsorbing antigens and antibodies on barium stearate multilayers immunological reactions at surfaces have been studied. Pneumococcus polysaccharide specific antibody systems using purified antibodies from both horse and rabbit sera were investigated. The polysaccharides failed to show visible adsorption, but by alternate treatment with antibody and polysaccharide several layers of antibody could be specifically deposited. With the diphtheria toxin-antitoxin system antitoxin was found to adsorb to layers of toxin but not conversely. The reaction, however, was not specific. Molecular weights calculated from the thickness of adsorbed protein layers, using dissymmetry factors, roughly correspond to molecular weights calculated from sedimentation and diffusion constants. PMID- 19870876 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : VI. EXPERIMENTS ON THE SENSITIZATION OF GUINEA PIGS TO POISON IVY. AB - Experiments are described on the latency period in sensitization to poison ivy and on the time necessary for the agent to remain in contact with the skin. The chief matter of investigation concerned the manner in which the whole skin becomes sensitive following treatment at a particular site, and especially whether this is effected by way of the epidermis. Two methods were used to interrupt the continuity of the skin, one by cutting through both skin and the underlying thin muscular layer, the other by removing a strip of skin so as to spare the skin muscle. These procedures led to different results when poison ivy extract was applied to the areas thus isolated. In the first case, sensitization was mostly prevented, whereas with the second method generalized hypersensitiveness occurred almost uniformly. An explanation is to be found in the severance of the lymph vessels lying on the surface of the muscular layer, pointing to the necessity of a free lymph passage. On the other hand the experiments prove that general sensitization is not dependent upon maintaining the integrity of the skin around a treated area. An inhibition of sensitization by incisions extending through the panniculus carnosus was seen to some extent in anaphylactic sensitization with protein antigens, namely when sufficiently small amounts were employed. PMID- 19870877 TI - ELECTROPHORESIS OF ANTERIOR PITUITARY PROTEINS. AB - The moving boundary method of electrophoresis has been applied to a study of pituitary extracts and purified protein fractions derived from these extracts. The technique employed was that developed by Tiselius and involved the optical observation of the protein boundaries by Toepler's schlieren method. The present experiments were designed primarily to determine the number of proteins present, the degree of homogeneity of the various fractions, and the electrophoretic mobility of the individual components under standard conditions. The preparations studied included crude gland extracts obtained with dilute alkali, glycerol, and saline; purified pituitary fractions prepared by isoelectric and precipitation procedures; and freshly prepared and aged solutions of crystalline prolactin. The bulk of the crude gland extracts is composed of physiologically inert proteins, the gradual removal of which in the course of the chemical purification procedures could be controlled by electrophoretic analysis. Freshly prepared solutions of crystalline prolactin exhibit a high degree of electrochemical homogeneity. Upon storage, however, a second component, presumably denatured prolactin, is formed. PMID- 19870878 TI - EPIDEMIOLOGY OF LYMPHOCYTIC CHORIOMENINGITIS IN A MOUSE STOCK OBSERVED FOR FOUR YEARS. AB - A small mouse stock in which lymphocytic choriomeningitis is endemic has been observed over a period of 4 years. The disease has persisted during that time, but it has become so mild that it can no longer be recognized by clinical observation. In spite of this fact, all of the stock mice tested, both young and old, carried considerable amounts of virus in their organs and blood. The females readily transmit the infection to their offspring. Intrauterine infection has become the only mode of transmission of the disease in contrast to the situation in 1935 when a certain number of mice were born virus-free and became infected by contact shortly after birth. The present mildness of the disease appears to be due to two factors, namely, the change in its mode of transmission just mentioned, and a shift in the severity of the disease with regard to the age of the host at the time of infection. This shift has occurred gradually since 1935 when the mice infected in utero were the only ones to become sick. Since 1937, however, the virus is quite harmless for such animals and produces symptoms only in suckling mice from the virus-free stock exposed to contact infection. Evidence is presented which suggests that the shift in the severity of the disease was caused by a decrease of the pathogenicity of the virus for embryonic mouse tissue and a concurrent increase of the resistance to intrauterine infection of the mice from the infected stock. Another change noted concerned the communicability of the experimental disease. In contrast to observations made in 1935 the experimental infection of mature mice from the virus-free colony is now very rarely transmitted by contact to healthy mice, young or old. Suckling mice from the same stock infected by intranasal instillation of virus, however, readily transmit the disease and continue to do so as they grow up. The same is true for mice infected naturally. The reason for this discrepancy has not been ascertained, but it has been shown that naturally infected mice capable of transmitting the disease in general discharge large amounts of virus through the nose for a longer period of time than mature mice infected experimentally which fail to transmit their infection. It may likewise be of significance in this connection that the virus can lose its communicability by animal passage. A marked change (chiefly climatic and dietary) in the environmental conditions of the infected stock failed to influence the course and character of the epidemic. PMID- 19870879 TI - OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS. AB - In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods. PMID- 19870880 TI - EXPERIMENTAL HYPERTENSION : THE EFFECTS OF UNILATERAL RENAL ISCHEMIA COMBINED WITH INTESTINAL ISCHEMIA ON THE ARTERIAL BLOOD PRESSURE. AB - Unilateral renal ischemia superimposed upon intestinal ischemia has resulted in a prolonged elevation in the arterial blood pressure in a high percentage of the animals which were studied. PMID- 19870881 TI - SEROLOGICAL STUDIES OF SWINE INFLUENZA VIRUSES. AB - 1. Cross-neutralization tests with sera from swine recovered from infection with swine influenza indicated the serological identity of 7 strains of swine influenza virus obtained from different sources. 2. Cross-neutralization tests with sera from rabbits, immunized to swine influenza virus, exposed serological differences among the same 7 swine influenza virus strains. Two strains appeared to be serologically similar and were characterized by the ability to produce effective homologous virus-neutralizing sera which were, however, poor or ineffective against the heterologous virus strains. Two other strains were also serologically similar but produced antibodies effective not only against themselves, but against all heterologous strains as well. The remaining 3 strains were intermediate in their ability to produce heterologous virus-neutralizing antibodies. 3. The human influenza viruses included, especially strains WS and Oakham, were most effectively differentiated serologically from the swine influenza viruses by rabbit antisera. 4. The suggestion is advanced that swine antisera express the antigenic composition of the swine influenza viruses, while rabbit antisera reflect either their antigenic arrangement or the arrangement of the components responsible for their mouse pathogenicity. On this interpretation the 7 strains of swine influenza virus studied would be considered to have similar antigenic compositions but differing antigenic structures. 5. The serological differences among strains of the swine influenza virus, detectible by rabbit antisera, are probably of no practical significance so far as the natural disease, swine influenza, is concerned. PMID- 19870882 TI - AMOUNT AND DURATION OF IMMUNITY INDUCED BY INTRADERMAL INOCULATION OF CULTURED VACCINE VIRUS. AB - Continued cultivation of vaccine virus in a medium consisting of minced chick embryo tissue and Tyrode's solution has resulted in a virus qualitatively changed to such an extent that considerable amounts of it can be injected intradermally into human beings without danger or inconvenience. Individuals who are vaccinated intradermally with the cultured virus should be revaccinated dermally six months to a year later with a potent calf lymph virus in order to obtain a satisfactory immunity to smallpox without being subjected to the dangers and inconvenience associated with primary vaccinations with calf lymph virus. PMID- 19870883 TI - PROTECTIVE ANTIBODIES IN THE SERUM OF SYPHILITIC RABBITS. AB - 1. When an emulsion containing virulent Treponema pallidum is added to serum from normal rabbits and from untreated immune syphilitic rabbits that have been infected with a homologous strain of T. pallidum the mixture incubated at 37 degrees C., and injected intracutaneously into normal rabbits, typical syphilitic lesions commonly develop at the sites of inoculation of the normal serum spirochete mixture, while at the sites of inoculation of immune serum-spirochete mixtures usually either no lesion develops or else the incubation period of the resulting lesions is shorter and the lesions remain smaller than those produced by normal serum-spirochete mixtures. 2. In a series of preliminary experiments, of 56 areas inoculated with serum-spirochete mixtures, in 42 the suppressive action of the syphilitic serum was manifest, in 10 areas questionable evidence of protection was noted, and in 4 areas there was no evidence that the syphilitic serum had exerted a suppressive or protective action. 3. The protective action of syphilitic serum seems to have been lessened by heating to 56 degrees C. 4. The results of the protection test in three other series of experiments were as follows: (a) Of 12 areas in 6 rabbits inoculated with normal serum-spirochete mixtures typical syphilitic lesions developed, while in the same number of areas inoculated with immune serum-spirochete mixtures there was complete or partial suppression of lesions in all. (b) Of 45 areas inoculated with serum from 10 different immune syphilitic rabbits, definite evidence of protection was observed in 37, questionable evidence in 5, and no evidence of protection in 3. (c) Of 8 areas in 4 rabbits inoculated with immune serum-spirochete mixtures no lesions developed during the period of observation, while of 8 areas in the same rabbits inoculated with one of two normal serum-spirochete mixtures typical syphilitic lesions developed in each. PMID- 19870884 TI - STUDIES ON A BACTERICIDAL AGENT EXTRACTED FROM A SOIL BACILLUS : I. PREPARATION OF THE AGENT. ITS ACTIVITY IN VITRO. AB - A Gram-positive, spore-bearing, aerobic bacillus, capable of lyzing the living cells of many Gram-positive microbial species, has been isolated from soil. Cultures of this soil bacillus in peptone media release during autolysis a soluble agent which exerts a bactericidal effect on all the Gram-positive microorganisms so far tested, and inactivates their glucose dehydrogenases. It also inhibits the growth of the susceptible species in culture media. Several of the Gram-positive species undergo lysis when incubated with the bactericidal agent. It appears however, that lysis is only a secondary process, due to the autolytic enzymes of the susceptible cells, and that it follows upon some other primary injury caused by the active agent. The bactericidal agent is ineffective against all the Gram-negative bacilli so far tested. PMID- 19870885 TI - THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : II. THE RESPONSE OF MICE TO THE NASAL INSTILLATION OF VARIOLA VIRUS. AB - Variola virus was cultivated in embryonated eggs from smallpox crusts and maintained through 85 passages. Therein it produced foci of cellular proliferation and necrosis on the chorioallantoic membrane but did not affect the embryo. The virus from egg cultures was inactive in the skin of the rabbit on primary injection and in the testis both initially and on passage. In the monkey it provoked a cutaneous eruption of short duration after an incubation period of 5 days. On nasal instillation in the mouse the virus caused no symptoms and failed to survive on the mucous membrane of the upper air passages. Beginning with the 64th egg passage it was regularly recoverable from the lung, on subinoculation in eggs, through the 5th day and occasionally through the 7th day. Its presence in the lung was attended by progressive pathological changes. PMID- 19870886 TI - STUDIES ON A BACTERICIDAL AGENT EXTRACTED FROM A SOIL BACILLUS : II. PROTECTIVE EFFECT OF THE BACTERICIDAL AGENT AGAINST EXPERIMENTAL PNEUMOCOCCUS INFECTIONS IN MICE. AB - In the first paper of this series, a description was given of a cell-free extract, obtained from autolysates of a particular strain of a soil bacillus, which selectively inhibits the growth of all the Gram-positive microorganisms so far tested, and exerts on them a bactericidal effect in vitro. In the present study it is shown that the same agent protects white mice against infection with large numbers of virulent pneumococci. It also exerts a curative effect when administered to mice several hours after injection of the infecting organisms. The degree of protection afforded, and the minimal effective dose of bactericidal agent, are approximately the same for all virulent pneumococci, irrespective of type specificity. The bactericidal agent is entirely ineffective against infection with virulent Friediander bacilli (type B). This agrees with the fact that the agent does not affect Gram-negative bacilli in vitro. The protective action exerted by the bactericidal agent against experimental pneumococcus infection depends upon the same mechanism which determines its bactericidal effect in vitro. PMID- 19870887 TI - THE SIMULTANEOUS OCCURRENCE OF THE VIRUSES OF CANINE DISTEMPER AND LYMPHOCYTIC CHORIOMENINGITIS : A CORRECTION OF "CANINE DISTEMPER IN THE RHESUS MONKEY". AB - A particular strain of canine distemper, long maintained by serial passage in dogs and ferrets was found to contain the virus of lymphocytic choriomeningitis in addition to that of distemper. PMID- 19870888 TI - ARTIFICIAL MAINTENANCE MEDIA FOR CELL AND ORGAN CULTIVATION : II. THE CULTIVATION OF ORGANS IN ARTIFICIAL MEDIA. AB - Experiments have been described in which organs cultivated in the Lindbergh apparatus have been kept alive in artificial media for periods ranging from 3 days to 3 weeks, with life continuing in portions of some glands for from 35 to 62 days. The media used varied in composition from very simple and inexpensive ones in which some serum was used to a rather complex medium containing only that negligible amount of serum that is necessary as a solvent for vitamin A. The experiments performed demonstrate that artificial media can be used for organ cultivation, thus making it possible to study the behavior of human organs; to control the composition of the media at will; and to reduce the cost of experimentation. PMID- 19870889 TI - THE BEHAVIOR OF ABNORMAL HUMAN THYROID TISSUE CULTIVATED IN THE LINDBERGH APPARATUS. AB - 1. Human thyroid tissue may be kept alive and in good condition in the Lindbergh apparatus for at least 3 weeks, in usable condition from 1 to 2 months, provided that the vascular tree remain patent and functioning. 2. Experiments with altered amounts of iodin, adrenalin, hormones, and other substances show constant results only in connection with eschatin and pitressin which, in concentrations of 1:1000 in the perfusate almost invariably cause hyperplasia of the explanted tissue. 3. The original state of the tissue and the character of the symptom complex in the patient from which it was taken appeared to play no part in the subsequent behavior of the tissue explants. 4. In one experiment a most remarkable metaplasia was observed in the explanted thyroid tissue during the 6 to 8 weeks that it remained in two apparatuses. The cause of this is not evident. PMID- 19870890 TI - A SOLUBLE ANTIGEN OF LYMPHOCYTIC CHORIOMENINGITIS : I. SEPARATION OF SOLUBLE ANTIGEN FROM VIRUS. AB - The virus of lymphocytic choriomeningitis can be sedimented in the ultracentrifuge and washed repeatedly; the virus retains its activity provided that a small amount of normal serum is present in the diluent. A soluble substance capable of fixing complement in the presence of immune serum can be separated from the virus. Washed virus fixes complement poorly. The serologically specific soluble antigen is widely distributed in tissues of infected guinea pigs, mice, and monkeys. PMID- 19870891 TI - CELLULAR REACTIONS TO A DYE-PROTEIN WITH A CONCEPT OF THE MECHANISM OF ANTIBODY FORMATION. AB - 1. The use of an antigen which can be seen within cells demonstrates that one may stimulate the phagocytic cells either of the liver and spleen or of the tissues and lymph nodes to produce antibodies. 2. The appearance of antibodies in the serum correlates with the time when the dye-protein is no longer visible within the cells and with the phenomenon of a partial shedding of their surface films. 3. It is thus inferred that the cells of the reticulo-endothelial system normally produce globulin and that antibody globulin represents the synthesis of a new kind of protein under the influence of an antigen. 4. An antigen is a substance which can specifically modify the synthesis of the cytoplasm of the cells of the reticulo-endothelial system. PMID- 19870892 TI - POLIOMYELITIS AND THE LYMPHATIC APPARATUS. AB - In rhesus monkeys the Toomey "T" strain of poliomyelitis virus could not be detected in cervical or thoracic duct lymph after intranasal or intracerebral inoculation. PMID- 19870893 TI - A MOUSE TEST FOR MEASURING THE IMMUNIZING POTENCY OF ANTIRABIES VACCINES. AB - 1. A quantitative practical mouse test is described for measuring the immunizing potency of antirabies vaccines. 2. Virulent virus, injected intraperitoneally as a vaccine, immunized mice within 10 days and for a period of at least 9 months. Demonstrable neutralizing antibodies accompanied this immunity. Virus given subcutaneously failed to immunize as effectively. The margin between immunizing and infecting dose of vaccine was small. 3. Commercial vaccines containing virulent virus prepared for the treatment of man gave results similar to those obtained with laboratory virus. 4. Commercial vaccines inactivated with phenol and prepared for the treatment of man in general failed to immunize mice. None contained virulent virus. The phenolized preparation from one commercial firm, however, as also the chloroformized preparation from another, immunized mice consistently when given intraperitoneally in quantities approximating 5 times that advocated per gm. of body weight in man. 5. Commercial canine vaccines inactivated with phenol proved non-virulent and failed to immunize mice. 6. Commercial canine vaccines inactivated with chloroform (Kelser) proved non virulent but capable of immunizing mice provided a single intraperitoneal injection of 2 to 5 times that prescribed for dogs per gm. of body weight was given. 7. Chloroformized vaccines proved irritative to the peritoneum of mice. PMID- 19870894 TI - LUNG EDEMA FOLLOWING BILATERAL VAGOTOMY : STUDIES ON THE RAT, GUINEA PIG, AND RABBIT. AB - 1. Small animals (rat and guinea pig) vagotomized in the neck die within a period of hours, the lungs showing extensive congestion and edema. 2. Tracheotomy permits appreciably longer survival with minimal lung changes approximating those seen in the control animals. 3. Intrathoracic vagotomy (sparing the recurrent laryngeal nerve) on one side, and cervical vagotomy on the other, permits almost indefinite survival (guinea pig and rabbit), unless laryngeal paralysis from the unilateral denervation produces respiratory obstruction (rat, guinea pig, and rabbit). 4. Pulmonary edema following bilateral vagotomy probably results primarily from respiratory obstruction. It is suggested that circulatory failure may also be a factor of some importance. The role of vagotomy itself is considered in relationship to these two phenomena. 5. The reaction of smaller animals to bilateral vagotomy, with regard to lung changes, apparently differs in no way from that of the larger animals, but is less readily demonstrated because of the smaller diameters of the air passages. PMID- 19870895 TI - IMMUNE RESPONSE OF RABBITS TO INJECTION OF PLASMODIUM KNOWLESI. AB - Specific complement-fixing antibodies are produced in the serum of rabbits in response to injections of living or dead Plasmodium knowlesi. Sera from rabbits receiving injections of either parasitized or normal monkey erythrocytes are parasiticidal in vitro for P. knowlesi. Because absorption of parasiticidal rabbit sera with normal monkey erythrocytes abolishes the parasiticidal effect, it is concluded that the effect is largely due to an antibody to the red cells. Normal rabbit serum is not parasiticidal. Experiments on passive protection in monkey malaria with serum from rabbits which have received intraperitoneal injections of living or dead P. knowlesi yield no conclusive evidence that protective antibodies are formed. PMID- 19870896 TI - PRODUCTION IN MONKEYS OF COMPLEMENT-FIXING ANTIBODIES WITHOUT ACTIVE IMMUNITY BY INJECTION OF KILLED PLASMODIUM KNOWLESI. AB - Injection into rhesus monkeys of Plasmodium knowlesi killed by heat, formalin, drying, or freezing and thawing stimulates the production of complement-fixing antibodies, but no demonstrable agglutinating or protective antibodies are formed. Possible differences in the immunity mechanisms concerned in active infection and in artificial immunization are discussed. PMID- 19870897 TI - FAMILIAL MAMMARY TUMORS IN THE RABBIT : I. CLINICAL HISTORY. AB - The clinical histories of two different types of familial mammary cancer in the rabbit have been described. In one type, the first clinical sign of breast abnormality was a sudden and intense engorgement and thereafter the disorder passed through stages of cyst formation and benign neoplasia to cancer with metastasis. In the second type, neoplasia originated in clinically normal breast tissue and there was no history of antecedent mammary abnormality. PMID- 19870898 TI - FAMILIAL MAMMARY TUMORS IN THE RABBIT : II. GROSS AND MICROSCOPIC PATHOLOGY. AB - The pathological histories of two types of familial mammary cancer in the rabbit have been described. One type was distinguished by characteristic antecedent mammary changes similar to those found in Schimmelbusch's disease in women and by a distinctive papillary structure. The second type originated in normal breast tissue and was characterized histologically by an atypical proliferation of acini. PMID- 19870899 TI - FAMILIAL MAMMARY TUMORS IN THE RABBIT : III. FACTORS CONCERNED IN THEIR GENESIS AND DEVELOPMENT. AB - The clinical and pathological course of 25 mammary tumors in rabbits has been described. The antecedent breast history and morphology of the growths allowed a natural classification into two distinct types, one of which was distinguished by a preexisting cystic mastitis and a papillary structure, while the other originated in clinically normal mammary tissue and was characterized by an adenomatous structure. The two types of neoplasia occurred almost exclusively in two family groups and heredity played a fundamental role both in the occurrence of the tumors and in the determination of tumor type. Endocrine changes, comparable with those found in animals after long continued administration of estrogenic substances, occurred in tumor-bearing rabbits and it was inferred that the spontaneous growths represented a natural counterpart of the experimental induction of neoplasia with estrone. PMID- 19870900 TI - HEPATIC INJURY ON A NUTRITIONAL BASIS IN RATS. AB - In forty-eight rats kept on a basal diet deficient in the vitamin B complex and supplemented with vitamin B(1) and riboflavin or with vitamin B(1), riboflavin and vitamin B(6), various pathological changes in the liver were observed. These changes were characterized mainly by parenchymatous and fatty degeneration, focal and massive necrosis, hyperemia and hernorrhage and, in some of the rats, by perilobular and condensation fibrosis. Addition of yeast or Peters' eluate (yeast extract) regularly prevented this hepatic injury. On the basis of the evidence obtained, it is assumed that the liver changes are of nutritional origin and should be correlated to deficiency of a part of the vitamin B(2) complex. PMID- 19870901 TI - ROLE OF INBORN RESISTANCE FACTORS IN MOUSE POPULATIONS INFECTED WITH BACILLUS ENTERITIDIS. AB - 1. Under conditions in which mouse typhoid is allowed to spread naturally among herds of mice comprised of different proportions of individuals of innately high or low susceptibility: (a) 85 to 95 per cent of the innately susceptible succumb to mouse typhoid in contrast to less than 5 per cent of the innately resistant, regardless of whether either constitutes 25, 50, or 75 per cent of the population respectively. (b) The surviving population is therefore comprised largely of individuals known at the outset to be innately resistant. These resistants are, nevertheless, apt to have become infected and to harbor mouse typhoid bacilli in their spleens and feces. 2. Under conditions in which recruits are added to surviving populations comprised chiefly of innately resistants among which mortalities have practically ceased: (a) Mouse typhoid infection spreads to both innately resistant and susceptible recruits. (b) Mortality from mouse typhoid is limited almost exclusively to the innately susceptible recruits and is "sporadic" or "epidemic" in character according to the numbers and proportion of susceptibles added. (c) Innately resistant recruits remain well unless subjected to some non-specific hazard, such as heat or overcrowding, in which case both they and the susceptibles succumb in proportions similar to their relative numbers in the population. 3. It was plain that survivors are almost exclusively the individuals known at the outset to have been innately resistant. 4. There was no tendency for known susceptibles to become immunized through herd exposure at epidemic times, at postepidemic times in which the dosage of mouse typhoid bacilli was relatively small, nor at repeated short intervals. Finally, susceptibles given repeated, known, sublethal doses of mouse typhoid bacilli or St. Louis encephalitis virus by a natural route failed to develop immunity against a subsequent test dose. PMID- 19870902 TI - NEUTRALIZATION OF EPIDEMIC INFLUENZA VIRUS : THE LINEAR RELATIONSHIP BETWEEN THE QUANTITY OF SERUM AND THE QUANTITY OF VIRUS NEUTRALIZED. AB - A linear relationship exists between the logarithm of the quantity of epidemic influenza virus neutralized and the logarithm of the quantity of antiserum which is capable of achieving this result. This relationship is the same for the serum of a ferret convalescent from experimental influenza as for the serum of a rabbit immunized with the virus. By means of the linear relationship between virus and antiserum it is possible to determine a fixed, rather than a relative, value for the neutralizing capacity of a serum. PMID- 19870903 TI - THE PRODUCTION OF KIDNEY ANTIBODIES BY INJECTION OF HOMOLOGOUS KIDNEY PLUS BACTERIAL TOXINS. AB - Rabbits injected with emulsions of homologous kidney to which staphylcoccus or streptococcus toxins had been added produced complement fixing antibodies which reacted with both rabbit kidney and brain. By absorption tests it was demonstrated that the sera contained at least two antibodies, one specific for kidney, the other non-specific. Similar kidney antibodies were found in the blood of a majority of patients with scarlet fever but in only a few normal persons. The possibility that a similar or related antibody may be concerned in the etiology of scarlatinal nephritis is discussed. PMID- 19870904 TI - A CULTURE FLASK FOR THE CIRCULATION OF A LARGE QUANTITY OF FLUID MEDIUM. AB - An apparatus has been developed which permits the cultivation of a large number of tissue fragments in a large quantity of culture medium. The tissue fragments are cultivated in a thin layer of well oxygenated and constantly circulating medium. PMID- 19870905 TI - THE IMMUNOLOGICAL RELATIONSHIP OF THE CAPSULAR POLYSACCHARIDE OF TYPE XIV PNEUMOCOCCUS TO THE BLOOD GROUP A SPECIFIC SUBSTANCE. AB - 1. The agglutination of human erythrocytes and the precipitation of the blood group A substance by Type XIV antipneumococcus horse serum are properties of the specific anticarbohydrate immune bodies in the serum. 2. Absorption of Type XIV antipneumococcus horse serum with the homologous bacterial polysaccharide removes the agglutinins for human erythrocytes as well as the precipitins for the group A substance. 3. Absorption of Type XIV antipneumococcus horse serum with the group A substance markedly diminishes the ability of the serum to agglutinate erythrocytes of all groups. 4. Absorption of Type XIV antipneumococcus horse serum with human erythrocytes causes a marked diminution in the precipitation with group A substance. 5. The chemical and immunological relationship between the specific substances of blood group A and the Type XIV Pneumococcus is discussed. PMID- 19870906 TI - STUDIES ON A BACTERICIDAL AGENT EXTRACTED FROM A SOIL BACILLUS : III. PREPARATION AND ACTIVITY OF A PROTEIN-FREE FRACTION. AB - A cell-free extract of cultures of an unidentified soil bacillus, which exerts a bactericidal effect on Gram-positive microorganisms, has been described in previous reports; the first active preparations which were obtained were found to contain a protein precipitable at pH 4.5. It is shown in the present report that the bactericidal agent can be obtained in an active form free of protein. The new purified preparations retain all the activity of the original material, both in vitro and in vivo. PMID- 19870907 TI - THE MANNER OF GROWTH OF FROG CARCINOMA, STUDIED BY DIRECT MICROSCOPIC EXAMINATION OF LIVING INTRAOCULAR TRANSPLANTS. AB - The adenocarcinoma which commonly occurs in the kidney of leopard frogs has been transplanted into the anterior chamber of the eye where its growth characteristics have been studied by direct observation with the slit-lamp microscope. Such observations have been amplified by photographs taken at intervals to furnish permanent and objective records of the mode of development and progress of the growths, from earliest to advanced stages. The fifteen tumors which fumished the transplants were typical large invasive adenocarcinomas having the usual irregular and apparently anarchic arrangement of their component tubules and acini. However, the transplanted tumors developed according to definite and well defined structural patterns, their type depending on the immediate physical environment. Three such morphogenetic patterns were observed. Unimpeded outgrowths into the aqueous tumor characteristically assumed a tubulo papillary arrangement; the earliest formation consisted of solid, purely epithelial cylinders, many of which at later stages acquired a lumen and thus became tubular; generally only the coarser projections developed vascular stalks. Further growth was made by repeated branching, and lateral outpouching of the tubules. Where the tumor grew in contact with firm, even surfaces, such as lens or cornea, differentiation was lost and broad membranes formed which gradually spread over the surfaces; secondarily, new cylindrical or tubular processes arose from such indifferent cellular carpets. Where the tumor made contact with loose tissue such as iris, it invaded this organ, and, supported by the stroma, assumed an acinar pattern quite like that of the original adenocarcinoma of the kidney. All three types of growth were sometimes found coexisting in different portions of the anterior chamber. The rate of growth of transplanted tumors was followed by photographic records taken periodically. A fairly constant mode of progress was noted: after a variable period of lag and a period of gradual outgrowth, there followed rather abruptly a short period of rapid growth, after which growth increments gradually became smaller. Variations in growth rate due to season and to temperature were evident, but further experiments are required to evaluate the part played by these factors. Attempts to transplant normal kidney in the anterior chamber were unsuccessful. The manner of growth in the vitreus was found to be similar to that in the anterior chamber. The factors that determine the manner of tumor growth are as yet imperfectly understood. Evidence is however accumulating to the effect that neoplastic growth is not as anarchic as is suggested by histologic sections of some tumors (26). The present experiments support the view that cancers are much more responsive to the laws governing growth and organization than is generally supposed. PMID- 19870908 TI - CHARACTERISTICS OF FROG CARCINOMA IN TISSUE CULTURE. AB - The adenocarcinoma of leopard frogs may be cultivated with ease in plasma media. In such cultures two types of growth occur with regularity. The first is in the form of tubules which promptly grow out in the solid medium and retain their tubular form as long as they remain completely enveloped by plasma. When, however, they make contact with the surface of the glass, they adhere to it, the part in contact becomes flat, and its cells now grow no longer as tubules but as membranes. The manner of growth in vitro resembles the growth of transplants of the same tumor in the anterior chamber of the living eye, thus suggesting that in each case the habit of growth is determined by the same morphogenetic factors, i.e. those inherent in the cells themselves, and those depending on interfacial forces. The malignant cells of the frog carcinoma have the attributes which in general distinguish malignant cells from normal cells of corresponding type. In comparison with adult kidney cells, their normal homologues, the conspicuous properties of frog carcinoma cells are: larger and more variable size and shape of cell body, of nucleus, and nucleolus; coarser and denser structure of cytoplasm, of nucleoplasm, and of nuclear membrane; increase in number of mitochondria, and more frequent occurrence of mitosis. These cytological characteristics remain unaltered in cultures maintained for as long as six months. Frog carcinoma is a transmissible disease due to an agent which induces inclusion bodies, and which has other attributes indicating that it is a virus. The general correspondence in character between its cells and the malignant cells of mammalian tumors of diverse origin suggests that neoplastic phenomena are essentially alike, no matter in what group of animals they occur or what their causal factors may be. PMID- 19870909 TI - THE PASSAGE OF PROTEINS FROM THE VASCULAR SYSTEM INTO JOINTS AND CERTAIN OTHER BODY CAVITIES. AB - 1. Experiments designed to study, in the rabbit, the passage of foreign proteins from the blood stream into synovial fluid and to compare such passage with that taking place into the aqueous humor, spinal fluid, and urine are described. 2. Crystalline egg albumin and horse serum proteins regularly appeared in the knee joints within short periods of time following their intravenous injection. 3. These proteins also appeared promptly in the aqueous humor but in lower concentrations. In the spinal fluid they appeared only rarely and in minimal amounts. 4. Crystalline egg albumin was readily eliminated from the body via the urine. It was also removed rapidly from the knee joint and anterior chamber of the eye. 5. Horse serum proteins appeared only occasionally in the urine. Their concentration in the blood serum remained relatively high for several days. Their increased concentration in the joint fluids in the longer experiments indicates that the rate of entrance exceeded the rate of removal. 6. Foreign proteins of the type employed were all found in the joint fluids in higher concentrations than they were in the other body fluids examined. 7. The possible significance of this study with respect to normal joint physiology and to certain abnormal joint conditions has been commented upon. PMID- 19870910 TI - THE PASSAGE OF TYPE III RABBIT VIRULENT PNEUMOCOCCI FROM THE VASCULAR SYSTEM INTO JOINTS AND CERTAIN OTHER BODY CAVITIES. AB - 1. Within 24 hours following intravenous inoculation with rabbit virulent strains of pneumococcus Type III, most rabbits develop infections of one or both knees. The frequency of bilateral knee joint involvement increases as the duration of the disease is prolonged. 2. The spinal fluid, aqueous humor, and bladder urine remain sterile at a time when the knee joints contain pneumococci. Subsequently, however, they may be invaded. 3. The administration of a single dose of type specific horse immune serum, at a period when in all probability one or both knee joints contain organisms, appears to be ineffective in bringing about resolution of the infections process in these sites, even though horse serum constituents may be demonstrated serologically to be present within the joint cavities. PMID- 19870911 TI - ENCEPHALOPATHY FOLLOWING INJECTIONS OF BONE MARROW EXTRACT. AB - Monkey bone marrow extract when injected intracerebrally into guinea pigs or rabbits produces a distinctive encephalopathy. The Purkinje cells are severely affected, especially those at the periphery of the cerebellum. Nuclear alterations first appear, with well marked intranuclear acidophilic inclusion bodies. Similar inclusions appear at a little later stage in the ectodermal glia. The affected cells later become necrotic and usually disappear. The reaction is essentially glial and non-inflammatory, and hence is called encephalopathy rather than encephalitis. A hyaline necrosis of cerebral blood vessels, especially at the base of the brain, is described. Small areas of softening may appear in the cerebellum as a result, but this is considered a secondary process, independent of the Purkinje cell loss. There may also inconstantly be found a loss of cerebellar granule cells and a selective necrosis of the hippocampal pyramidal cells. Secondary and reparative reactions are described. Similar changes are produced by extracts of lymph nodes from Hodgkin's disease, and by leucocytic cream of human blood. A tentative explanation of the pathogenesis is suggested, and similarities to certain virus diseases are pointed out. PMID- 19870912 TI - A FURTHER CONTRIBUTION TO VITAMIN C THERAPY IN EXPERIMENTAL POLIOMYELITIS. AB - 1. Multiple paralytic doses of poliomyelitis virus (RMV strain), when brought together with small amounts of synthetic ascorbic acid in vitro, are rendered non infectious as determined by intracerebral injection of such mixtures into rhesus monkeys. 2. Vitamin C administration to monkeys infected intranasally with the RMV strain produces results which differ in accordance with the technique employed for nasal instillation. With an infection of maximum severity, induced by flooding the nasal portal of entry with large amounts of virus, vitamin C administration fails to exert any demonstrable influence on the course of the disease. With a less forceful method of droplet instillation, the picture of the disease in control animals becomes so variable that the results cannot be easily interpreted; but the available data suggest that vitamin C treatment may be a factor in converting abortive attacks into an altogether non-paralytic infection. 3. The administration of synthetic vitamin C to monkeys infected intracerebrally with small doses of the RMV strain gives results comparable to those previously obtained with this substance in monkeys infected intracerebrally with the Aycock strain of poliomyelitis virus. 4. The implications of the findings are discussed. PMID- 19870913 TI - THE RETICULO-ENDOTHELIAL SYSTEM AND HORMONE REFRACTORINESS. AB - 1. Young splenectomized female rats, free of latent infection, show greater increases in ovarian weight in response to injections of pregnant mare's serum than do young normal rats with spleens intact. 2. The regression in ovarian weight which occurs after about a month in such injected splenectomized animals may be prevented by repeated injections of an agent like trypan blue which causes blockage of the compensating reticulo-endothelial elements. 3. The plasmas obtained from these splenectomized and splenectomized dye-blocked animals possess less antihormone substance than plasmas from similarly treated normal animals. 4. Young female rats, heavily infected with Bartonella muris, and therefore possessing an injured reticulo-endothelial system, develop heavier ovaries in response to injections of pregnant mare's serum than do normal uninfected rats. 5. Similar differences in effect on the testes and seminal vesicles of young normal, splenectomized, and bartonella-infected male rats have been obtained using pregnancy urine extract. 6. Young splenectomized, and splenectomized dye blocked guinea pigs injected with thyrotropic extract, show heavier and more highly active thyroids than normal hormone-injected animals, 7. These results are explained on the basis that the reticulo-endothelial system participates in the production of antihormone substances. PMID- 19870914 TI - HEMOLYTIC STREPTOCOCCUS LYMPHADENITIS IN GUINEA PIGS. AB - A group of guinea pigs carrying a chronic streptococcus cervical lymphadenitis has been studied. The chronic disease may be transmitted with pure cultures of streptococci isolated from the naturally occurring abscesses. Its probable mode of transmission under natural conditions was shown to be the ingestion of the infective agent. The spontaneous appearance of an acutely fatal variant was observed. Infection with the chronic strains protected animals against the highly virulent strain. Such immunity could not be passively transferred to either mice or guinea pigs, nor could any opsonizing, precipitating, or bactericidal antibody be associated with it. The presence of allergy could not be correlated with this immunity. The dissociation of the chronic and acute strains was investigated and non-invasive phases isolated. No precipitin reaction attributable to an antigenic virulence factor could be demonstrated. No protection was obtained with vaccines or aggressins. PMID- 19870915 TI - THE VIRULENCE OF GROUP C HEMOLYTIC STREPTOCOCCI OF ANIMAL ORIGIN. AB - A non-antigenic mucoid polysaccharide similar to that described by Kendall, Heidelberger, and Dawson was isolated from group C hemolytic streptococci. A simple method for its quantitative estimation is described. By means of this quantitative method, as well as by the direct isolation of the carbohydrates, the size and persistence of capsules in young cultures of various strains have been related to the non-antigenic mucoid polysaccharide. Similarly, invasiveness in different strains has been related to the mucoid polysaccharide. Data indicating the non-haptene nature of this material are presented. An autolytic process, accelerated by bile, is involved in the loss of capsular material from young streptococci. PMID- 19870916 TI - ESTIMATION OF THE PURITY OF PREPARATIONS OF ELEMENTARY BODIES OF VACCINIA. AB - A method of estimating the purity of preparations of elementary bodies of vaccinia is described. It depends on the comparison of the number of infective units of virus in a given material with the number of elementary bodies. The latter figure is estimated from the dry weight of the preparation by means of a calculated value for the weight of a single dehydrated elementary body. Values for the ratio of infective units of vaccine virus to elementary bodies varied between 1 : 2.4 and 1 : 9.2 in seven consecutive experiments; the average was 1:4.2. These ratios indicate a high degree of purity of the preparation. Moreover, they indicate that a relatively high percentage of the elementary bodies in the preparations was infective. PMID- 19870917 TI - THE SPECIFICITY OF KERATEINE DERIVATIVES. AB - Carboxymethyl, alpha-carboxyethyl-, alpha-carboxy-n-propyl-, alpha carboxyisopropyl-, alpha-carboxy-n-butyl, alpha-carboxyisobutyl, alpha carboxyamyl-, benzyl-, and beta-phenylethylkeratemes were prepared from the parent protein, reduced keratin or kerateine. Chemical analysis disclosed that the various compounds differed in their isoelectric points and solubilities depending on the nature of the substituent group introduced. In general, it was found that in so far as could be determined, nearly all of the available sulfhydryl groups were substituted, while no detectable substitution of the free amino groups of the proteins occurred. The results of the serologic studies revealed that the kerateine derivatives acquired a new immunologie character dependent on the nature of the introduced determinant group. Inhibition tests confirmed the results obtained. Evidence was also produced to show that the grouping See PDF for structure may play a role in some of the reactions observed. PMID- 19870918 TI - ELECTROPHORETIC PATTERNS OF NORMAL AND PATHOLOGICAL HUMAN BLOOD SERUM AND PLASMA. AB - The electrophoretic patterns of a series of normal and pathological human sera and plasmas have been obtained using the schlieren scanning method. From these patterns the mobilities and concentrations of the electrophoretically distinct protein components have been computed. The mobilities fall into five well defined groups corresponding to albumin, alpha, beta, and gamma globulins, and fibrinogen. The concentrations of the different components in pathological sera have been compared with those in normal sera, and the following tentative generalizations may be made. The albumin/globulin ratios for pathological sera have been consistently lower than those for normal sera. The values of the alpha globulin/albumin ratio for the sera of the febrile patients studied were high, the average value being over twice the normal value. The gamma globulin/albumin ratios for aplastic anemia and rheumatic fever sera were also above normal. Certain pathological conditions, notably nephrosis, were accompanied by large increases in a gamma globulin. There is evidence that, in part at least, this consists of a labile lipo-protein. PMID- 19870919 TI - EXPERIMENTS ON HISTAMINE AS THE CHEMICAL MEDIATOR FOR CUTANEOUS PAIN. AB - Experimental evidence shows that histamine is liberated when the upper layers of the skin are stimulated in the threshold range although no gross or microscopic evidence of tissue damage is demonstrable. A histamine-like substance is recoverable from the anterior chamber of the rabbit's eye on electrical stimulation of the cornea. This substance is liberated in direct proportion to the intensity of the stimulus. Histamine when injected intradermally or applied to the denuded skin (less epidermis and some cutis) or cornea causes pain. That the substance liberated is most likely histamine was shown by its action on the intestinal strip of the guinea pig, which action was not effaced by adding atropine to the bath; by its heat stability, its neutralization by histaminase and its dialysability through cellophane membranes, and by the fact that thymoxyethyldiethylamine, which appears to be a specific antagonist to histamine, neutralizes the action of the diffusates of stimulated skin and when injected subcutaneously or rectally abolishes generally the pain responses to pinching, pricking and cutting, and lowers the electrical threshold of the skin markedly without affecting the somatic sensory nerve trunks. PMID- 19870920 TI - SEROLOGICAL STUDIES ON SUGAR : I. REACTIONS BETWEEN SOLUTIONS OF REAGENT SUCROSE AND TYPE II ANTIPNEUMOCOCCUS SERUM. AB - Solutions of all of the C. P. sucrose reagents of American manufacture that were tested gave reactions with Type II antipneumococcus serum. The capacity of that antiserum to react with sucrose solutions was removed by absorption with the homologous pneumococci or with Leuconostoc mesenteroides. The serological reactivity was due not to sucrose itself but to accompanying substances that could be removed by precipitation with a proper concentration of alcohol or by treatment with activated carbon. Although Type II antipneumococcus serum was used to detect its presence the reactive material found in the sucrose can be considered to be only related and not identical with antigens of Type II pneumococci. PMID- 19870921 TI - RADIOACTIVE IRON AND ITS EXCRETION IN URINE, BILE, AND FECES. AB - Radioactive iron as ferrous gluconate given by vein enables us to study iron excretion in urine, bile, and feces. There is an initial extra output in urine and feces during a few days (3 to 15 days) following the iron injection and this may total 2 to 8 per cent of the injected iron. Following this initial reaction the urinary excretion of radio-iron drops to traces or even to zero. The feces always contain measurable amounts of radio-iron-in five dogs receiving 100 to 250 mg. of radio-iron the fecal excretion per day settled down to 0.05 to 0.4 mg. per day. Blood destruction (acetyl-phenylhydrazine) causes a definite increase in radio-iron eliminated in the feces (0.1 to 1.0 mg. per day). Probably most of this excess iron comes through the biliary tract (bile fistula). The bile under usual conditions contributes very little iron to the intestine (0.01 mg. radio iron per day or less). The body controls its iron stores by absorption or lack of it rather than by its capacity to eliminate it. The evidence is overwhelming that the dog excretes iron with difficulty and in small amounts (even in the plethoric state) by means of the biliary and gastro-intestinal tracts. PMID- 19870922 TI - EXPERIMENTAL PRODUCTION OF DIGESTIVE TRACT ULCERATIONS. AB - We have attempted to reproduce in animal experiments a group of pathological findings which we have observed to be associated with shock. In order to simulate the compensatory vasomotor reactions occurring in shock, we have utilized the intraperitoneal injection of adrenalin hydrochloride in dogs, cats, rabbits and guinea pigs. That the effect of adrenalin hydrochloride when injected by this route is of long duration has been shown by the prolonged hyperglycemia which it produces. Our experiments have resulted in the production of a lesion in the digestive tract which is identical in the gross with those which we observed in our human material. The histological changes, however, have been found to differ from those encountered in the latter. These differences have been noted to occur only in the dog and cat, where the initial changes take place in the mucosa, and the alterations in the submucosa appear secondary to these. In the rabbit and guinea pig the histogenesis of the lesions is identical with that observed in man, the lesions first manifesting themselves in changes in the submucosa, congestion, edema and hernorrhage. Only later are similar changes seen in the mucosa, progressing finally to necrosis and ulceration. The cause of the histological differences has been found in the presence of arteriovenous anastomoses which occur in the submucosa in the case of the dog and cat and in the mucosa in the case of the rabbit, guinea pig and man. We have pointed out that variations in blood flow through the intestinal wall may result from the short circuiting of the blood through the arteriovenous anastomoses. This, associated with the vasoconstriction known to occur in shock, may if severe and prolonged, result in necrosis of the intestinal wall. We have experimentally reproduced the same lesion by the injection of adrenalin, which acts in a similar way. The experimentally produced anatomical changes offer additional evidence in support of the clinical occurrence of a vasospasm which is of sufficient severity and duration to cause tissue necrosis. PMID- 19870923 TI - A METHOD FOR THE STUDY OF INDUCED INTERFERENCE WITH TRANSPLANTABLE TISSUE GROWTH. AB - 1. A design of experiments and technical procedure is described for the study of interference with transplantable tissue growth by test agents. The methods are guided by the principle of randomization and are based on the pairing of test and control in each host. 2. A system of analysis, employing well known statistical measures, is applied to results obtained with these methods and shows that they lead to consistently reproducible results. 3. A simple analytical method is proposed for correlating results obtained with different kinds of transplantable tissue in different strains of animals. This method is based on the condensation of an extended frequency distribution of events in control series of cases into a three category array of a normal frequency distribution. The three categories of test action are the inhibitory, the ineffectual, and the accelerative. PMID- 19870924 TI - INHIBITION OF TRANSPLANTABLE MOUSE TUMOR GROWTH BY TISSUE EXTRACTS AND THEIR PROTEIN FRACTIONS. AB - 1. Mammary tissue of pregnant rabbits is found to contain an agent which inhibits the growth of Bashford Adenocarcinoma 63 in mice but this material is without effect on the Crocker Sarcoma 180. 2. Of the tissues so far studied the mammary gland of rabbits has yielded the most active product. 3. From the results it is probable that pregnancy enhances the production of the agent but this cannot be considered as established beyond doubt. 4. The factor is found, with diminished activity, only in the protein fraction obtained from the aqueous extract by full saturation with ammonium sulfate. PMID- 19870925 TI - EXPERIMENTAL MENINGOCOCCUS INFECTION OF THE CHICK EMBRYO. AB - 1. A strain of meningococci obtained directly from the spinal fluid of a patient has been propagated in serial passage in 10 to 12 day old chick embryos without change in its essential characteristics. 2. The chick embryo is susceptible to infection with the meningococcus, and, depending on its stage of development, reacts to the infection with more or less specific lesions. 3. In chick embryos of 15 days incubation, following the utilization of definite portals of entry, such as the nasopharynx, or by inoculation of the amniotic fluid or by inoculation of the body wall, the meningococcus is localized in specific areas, namely in the cranial sinuses, the lungs or meninges, or in all of these areas. 4. The lesions of the meningococcus infection in man, a septicemia, sinusitis, pneumonia and meningitis can be reproduced in the chick embryo by choosing embryos at the proper state of development and utilizing the various portals of entry experimentally available. PMID- 19870926 TI - THE PATHOGENESIS OF MENINGOCOCCUS MENINGITIS IN THE CHICK EMBRYO. AB - 1. A microscopic and bacteriological analysis of the meningitis produced in the chick embryo following inoculation of meningococci into the body wall or into the amniotic cavity indicates that the meninges are invaded by way of the blood stream. 2. There is no indication that a direct extension of the infection by way of the middle ear, the cranial sinuses or the pia-arachnoid sheath of the olfactory nerves to the meninges takes place. PMID- 19870927 TI - A STUDY OF PASSIVE IMMUNITY TO MENINGOCOCCUS INFECTION IN THE CHICK EMBRYO. AB - 1. 14 day old chick embryos are protected against subsequent meningococcus infection through the amniotic route by the intravenous administration of an homologous antiserum produced in hens, by a commercial concentrated polyvalent meningococcus antiserum and by a commercial meningococcus antitoxin. 2. Titrations of the different antisera indicate that the homologous and commercial polyvalent sera have approximately the same protective value and are much more effective than the commercial antitoxin. The titrations also show that the chick embryo is a sensitive indicator of the amount of antibodies present in a given amount of serum. 3. The mechanism of the protective action of the antisera is not apparent from these experiments except that in the treated embryos there is a relative inhibition of the growth and presumably a neutralization of the injurious products of the meningococci. PMID- 19870928 TI - ON THE NATURE OF THE PRESSOR ACTION OF RENIN. AB - 1. Tachyphylaxis occurs when renin is repeatedly injected into dogs and cats regardless of whether they are normal, anesthetized, pithed, hepatectomized, suprarenalectomized, nephrectomized, or eviscerated. 2. The pressor response to renin in brief experiments is independent of the height of the arterial pressure or the presence of the suprarenals. Evisceration and large doses of ergotamine reduce the response. It is largely uninfluenced by pithing, intracisternal injection of renin, cocaine, strychnine, caffeine, and infusion of sodium bicarbonate or hydrochloric acid. It may be slightly increased by large blood transfusions or hepatectomy but the result is short lived. 3. There is no parallelism between the pressor responses to carotid sinus stimulation, adrenine, and tyramine on the one hand and renin on the other. 4. Section of the brain may be followed by depressor responses to renin. 5. Intracisternal injection of renin elicits no significant rise in blood pressure or other circulatory manifestations. 6. Continuous infusion of renin produces a prolonged rise of arterial pressure in normal and chronically suprarenalectomized dogs, but the pressure ultimately falls despite continued infusion. 7. Tachyphylaxis develops in the isolated rabbit's ear perfused with blood and small doses of renin. The same blood perfused through a second ear causes no vasoconstriction when renin is added. Addition of renin-activator restores the ability of renin to cause constriction. 8. Renin alone causes no vasoconstriction when perfused with Ringer's solution, but renin plus renin-activator restores activity. Tachyphylaxis does not develop when Ringer's solution is employed instead of recirculating blood. 9. Blood from animals made tachyphylactic by repeated injections of renin is lacking in activator and also fails to cause vasoconstriction in the rabbit's ear when renin and renin-activator are added. 10. Renin-activator is lost and tachyphylaxis develops more slowly during continuous infusion of renin. Blood pressure may fall after a period of renin infusion despite the pressure in the blood of excess renin. Injection of partially purified activator restores the activator content of the blood as demonstrated in the rabbit's ear, but no rise in arterial pressure occurs. PMID- 19870929 TI - QUANTITATIVE STUDIES OF PROSTATIC SECRETION : I. CHARACTERISTICS OF THE NORMAL SECRETION; THE INFLUENCE OF THYROID, SUPRARENAL, AND TESTIS EXTIRPATION AND ANDROGEN SUBSTITUTION ON THE PROSTATIC OUTPUT. AB - A simple isolation of the prostate enabled quantitative collection of prostatic secretion in dogs over periods of months. The secretory stimulant was pilocarpine and 2 similar amounts injected with a 6 hour interval gave smaller amounts at the second testing, suggesting a fatigue effect. The prostate was not absolutely refractory since doubling the amount of alkaloid injected at the second test increased the volume to equal or exceed the preliminary secretion. The depression effect had disappeared at 24 hours. In normal dogs the secretory curves were essentially regular, with occasional prolonged rises or depressions. The amount of secretion did not bear a direct relationship to the weight of the gland in adult dogs. The germinal epithelium of the testis underwent atrophy during the first few weeks of cage life while the prostatic secretion was maintained, showing that the atrophy was differential and did not involve the cells producing the androgenic hormone. The atrophy was reversible and all dogs kept for more than 4 months showed restoration of the germ cells. A few dogs developed atrophy of the germinal cells with cessation of prostatic secretion for many weeks but with final recovery. Removal of the suprarenal glands with suprarenal insufficiency did not produce sterility. The distribution of electrolytes in the prostatic secretion differed from that in the serum-transudate system, although the concentration of osmotically active substances was the same, being made up almost entirely of sodium and chloride. The distribution was not affected by the different physiological procedures used in this study. Protein concentrations were less than 1 per cent. The rate of prostatic atrophy following castration was determined, and cessation of secretion occurred in 7 to 23 days. The restoration of prostatic fluid in castrate dogs following daily injections of testosterone propionate followed a smooth curve to form a plateau which was interrupted occasionally by prolonged elevations with return to the established level. The prostate having been reconstructed, the dosage of androgenic material injected could be greatly reduced without causing a decrease in secretion. Ablation of the thyroid and parathyroid glands had no significant influence on prostatic secretion. Hyperthyroidism caused a secretory depression interrupted with returns to normal levels. PMID- 19870930 TI - FURTHER STUDIES ON THE BLOOD AND THE HEMATOPOIETIC TISSUES IN MALIGNANT PANLEUCOPENIA OF CATS. AB - The most conspicuous clinical finding during the course of this virus disease is a fulminating panleucopenia. The earliest significant decrease noted is usually in the number of the lymphocytes. From the study of lymph nodes and bone marrow during the incubation period and throughout the illness, it appears that failure of leucopoiesis is the cause of leucopenia. Inclusion bodies in the primitive blood cells of the marrow suggest a direct action of the virus on these cells. When recovery occurs a marked myelogenous leucemoid response is noted. Available data indicate the presence of a mild anemia due to a failure in erythropoiesis, less marked than the leucopenia probably because of the longer life of the adult circulating erythrocytes. The erythrocytes appear to have an increased fragility and the serum has a slight increase in icterus, suggesting an increased mean erythrocyte age. During recovery erythropoiesis does not begin until after the myeloid marrow response has begun to subside, due possibly to previous mechanical crowding of the marrow by the more rapidly growing myeloblasts and myelocytes. PMID- 19870931 TI - EXPERIMENTAL STUDIES OF THE VIRUS OF INFECTIOUS AVIAN ENCEPHALOMYELITIS. AB - The results of investigations thus far carried out on experimental avian encephalomyelitis indicate that the virus of this newly described disease conforms to the group of definitely established viruses. It was essential to determine its taxonomy since the only prior record of its study (1) defines the infective agent as a virus because the usual cultural attempts failed to reveal a visible microorganism to be identified with it, and because the transmissible agent passed through Seitz and Berkefeld N filters. At the present time such determinants fail completely to satisfy the criteria for defining a virus and their acceptance would lead to the inclusion of certain filtrable microbic agents, difficult to reveal except by special cultural procedures, as viruses (10). The virus of avian encephalomyelitis is distinct from that of equine encephalomyelitis and is clearly a virus sui generis. The striking feature of its properties is its narrow range of host susceptibility-only the avian species are responsive to inoculation; ordinary laboratory animals are apparently resistant, even to large numbers of chicken cerebral infective doses. In addition, it is probable that its size is in the range of that of the equine virus. Studies also reveal that the virus is not easily sedimented by centrifugation (that is, at 5400 R.P.M. for one hour in the angle centrifuge and at 12,000 R.P.M. for one hour in the open air centrifuge) and is resistant to the action of glycerol and to drying. It is readily filtrable through Seitz one and two disc filters, through Berkefeld V and N candles, and is active in dilutions in broth up to 10( 6). It passes through gradocol membranes of 73 mmicro average pore diameter at least (the end-point has not as yet been definitely determined). An attack of the experimental disease leads to development of resistance to reinoculation and of antibodies in the serum. Old birds are reported as being refractory to infection, both in nature and in the laboratory (1, 2). Whether this resistance in mature animals is due to earlier exposure to infection, or to the development of structural or physiological barriers to invasion by the virus, remains still to be determined. Under experimental conditions, the route by which the virus acts uniformly to induce disease is the intracerebral. Yet in certain instances other peripheral ways of inoculation such as the intraperitoneal, subcutaneous, intradermal, intravenous, intramuscular, intrasciatic, may also be effective. Thus far, in limited experiments, feeding, or instilling nasally, or injecting into the vitreous body the infective agent has been ineffective. Whether the viral progression is axonal from peripheral sites is still to be determined; as should be also the question whether it multiplies in any of the organs other than the central nervous tissues. The virus was not detected in the blood during the period of incubation or during the acute phases of the experimental disease. So that unless it is found that other animals harbor the virus, or that still other sources of it exist as yet not disclosed, it is not likely that the disease is disseminated by a blood-sucking insect. The actual portal of entry and the factor in the spread of the disease in nature is still obscure, since the evidence here presented is still too incomplete to elucidate these problems. The pathological lesions induced are of interest. The neuronal reaction resembles that brought about by axonal disturbance (axon reaction, Nissl's or retrograde degeneration). The question may well be asked whether there may not be here an initial injury by the virus to the axonal process of the neuron, which in turn induces the retrograde changes in the cell body. This has as yet to be studied, as well as the possibility of viral progression along an axonal route with or without concurrent multiplication. The significance of the second major lesion in the central nervous system, namely, the generally marked perivascular reaction, is also still to be determined. Finally, the only observable and histopathological change in organs other than the central nervous tissues (in which we have not as yet noted the change) is in the hyperplasia of the normally present lymphoid islands. One is impressed by the prodigious numbers of lymphoid elements surrounding the vessels of the central nervous system and the question here is whether these hyperplastic areas serve as depots to supply the cells for this perivascular reaction. PMID- 19870932 TI - THE MASKING EFFECT OF EXTRAVASATED ANTIBODY ON THE RABBIT PAPILLOMA VIRUS (SHOPE). AB - The foregoing experiments have shown that the causative virus is usually "masked" in the large, disorderly, fissured and inflamed papillomas of cottontails when antiviral antibody is present in quantity in their blood, though virus can be recovered as a rule from the smaller, discrete, well ordered papillomas of these rabbits, almost irrespective of the amount of antibody in the blood of the individuals bearing them. Other findings are described which indicate that the masking of the virus in the large fissured growths is due to serum antibody present in them as result of exudation or hemorrhage, which neutralizes the virus when the growths are extracted or preserved in vitro. The local conditions that favor extravasation of serum (and the accumulation of antibody) prevail as a rule in the large, confluent growths arising after virus has been sown broadcast on scarified skin, but to lesser extent or not at all in the discrete papillomas that occur naturally or as result of tattoo inoculation. The state of affairs is notably different in the papillomas of domestic rabbits. The virus is regularly masked in these, and usually masked completely, even when there is little antibody in the blood and the local conditions do not favor its extravasation into the growths. The findings indicate that something other than antibody is primarily responsible for the masking in this species. PMID- 19870933 TI - BLOOD PLASMA PROTEINS AS INFLUENCED BY INTRAVENOUS INJECTION OF GUM ACACIA : II. PRODUCTION OF CHRONIC HYPOPROTEINEMIA. AB - By repeated weekly intravenous injections of gum acacia solution in dogs over periods of 4 to 5 months, it has been possible to maintain plasma protein concentration and total circulating protein at very low levels. If sufficient numbers of such injections are given and then discontinued, plasma protein concentration will remain below the normal limits for several more months. Acacia remains in the blood during this time. Reduction of fibrinogen concentration in such animals is out of proportion to and more marked than the changes in plasma protein concentration. This would indicate interference with liver function. Plasma volume when determined at 7 day intervals during injection periods at first diminishes, then rises 20 to 25 per cent above basal levels. The total blood volume does not show such marked changes because of a decrease in red cell volume. Globulins are reduced to a greater extent than albumin after a single injection of gum acacia, although both albumin and the globulins diminish. This cannot be accounted for by a decrease in fibrinogen alone. After 14 to 16 weekly injections, both albumin and globulins are more profoundly reduced. During injection periods in such animals, it has not been possible to control quantitatively the dietary intake, a complication which has made it difficult to ascertain the effect of various protein diets upon the protein-acacia balance. The changes described, however, have taken place regardless of various types of animal protein diets. Following periods of injection, in spite of very low plasma protein concentration and high acacia concentration in the blood, most of the dogs eat well and therefore they can be used during this period for controlled dietary experiments which may be of value in investigating the mechanism of the production and function of the plasma proteins. PMID- 19870934 TI - THE EFFECT OF DIETARY PROTEIN ON THE COURSE OF NEPHROTOXIC NEPHRITIS IN RATS. AB - Acute nephritis of medium severity, affecting both glomeruli and tubules, was produced in rats by injections of anti-rat-kidney serum, given on 3 consecutive days. The course of the nephritis was markedly influenced by the type of diet which was fed. Rats tended to recover promptly from the induced nephritis when a low protein-high carbohydrate diet was given. On the other hand, in nephritic rats maintained on a medium protein diet the nephritis almost invariably became chronic and half the animals died of renal insufficiency during the 10(1/2) months of observation. Finally none of the rats which received a high protein-low carbohydrate diet recovered from the acute renal injury; all developed chronic progressive nephritis and the majority died of renal failure after some months. PMID- 19870935 TI - PROLONGED MAINTENANCE OF SPIROCHETES AND FILTRABLE VIRUSES IN THE FROZEN STATE. AB - 1. Observations are reported on the virulence of various types of spirochetes and filtrable viruses after storage at - 787deg;C. for periods up to 3 years. 2. Five specimens of Treponema pallidum belonging to 4 different strains, and 7 specimens of T. pertenue belonging to 5 different strains were tested after storage for approximately 3 years. With one exception each specimen contained actively motile treponemes, and all specimens were highly pathogenic for rabbits. Many other specimens of these spirochetes stored for shorter periods were also tested with similar results. 3. Relapsing fever spirochetes tested after storage from 6 months to 1 year showed active motility and were virulent for mice. 4. Leptospira icterohemorrhagiae was found to be actively motile after storage for 5, 6, and 10 months. The spirochete of rat bite fever, Spirillum minus, was virulent for mice after storage for 1 year. 5. The virus of human influenza, PR8 strain, tested after storage for approximately 3 years was fatal to mice in essentially the same dilution as was the same lot of material before freezing. Similar results were obtained upon testing the virus of meningopneumonitis after storage for 3 years. The virus of lymphogranuloma inguinale was pathogenic for mice after storage for 10 months. PMID- 19870936 TI - FACTORS INFLUENCING THE SURVIVAL OF SPIROCHETES IN THE FROZEN STATE. AB - TITRATION EXPERIMENTS MADE WITH RELAPSING FEVER SPIROCHETES BEFORE AND AFTER FREEZING SHOWED THE FOLLOWING: 1. With each freezing and thawing there is a slight but regular decrease in virulence, which decrease bears no relation to the duration of storage at - 78 degrees C. Ordinarily infectivity is destroyed by more than 4 refreezings. 2. There was not always close correlation between motility and infectivity. 3. Cooling spirochetes from 0 degrees C. to -78 degrees C. over a 2 to 6 hour period damages them only slightly more than does rapid cooling, but warming from - 78 degrees C. to 0 degrees C. over a 2 to 6 hour period kills most of the organisms. Rapid thawing, as in a water bath, damages the spirochetes less than thawing more slowly, as at room temperature. 4. At storage temperatures of -12 degrees C. and -20 degrees C. there is a gradual decrease in virulence over a period of days or weeks, and by the 6th week the infectivity of the material is markedly reduced. PMID- 19870937 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : V. AGGLUTININ AND PRECIPITIN CONTENT OF ANTISERA TO HAEMOPHILUS INFLUENZA, TYPE B. AB - 1. The quantitative, absolute methods of agglutinin and precipitin analysis previously developed for antipneumococcus sera have been shown to be applicable to horse and rabbit anti-influenza type B sera and plasmas. 2. With the aid of these methods and improved immunization schedules the antibody content of the rabbit sera has been increased five to ten times. 3. The method recommended for the purification of rabbit antipneumococcus antibody has also been found applicable to rabbit anti-influenza type B sera. PMID- 19870938 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : V. HISTOPATHOLOGY IN THE MOUSE. AB - In mice affected with equine encephalomyelitis, the first pathological disturbance in infant animals is an inflammatory reaction, which is usually less pronounced in adult animals. A characteristic type of parenchymal damage appears to be independent of the inflammation. In such foci of injury there is initially a vacuolation of intercellular tissue. Neurones in such areas are at first intact, later show cytoplasmic changes, and finally nuclear alterations. Complete disintegration of tissue and all its elements may be the end result. PMID- 19870939 TI - STUDIES ON THE CULTIVATION OF THE VIRUS OF LYMPHOGRANULOMA VENEREUM. AB - Two strains of the lymphogranuloma venereum virus were maintained in tissue cultures for 12 and 21 generations respectively. In a third strain a quantitative increase in potency as high as 1000 times was obtained by inoculating tissue cultures with infected emulsions of known virulence. Greater increases in potency were consistently obtained by maintaining tissue cultures and virus at room temperature (23 degrees C. with a range of approximately +/- 5 degrees C.) than by incubating them at 37 degrees C. The virus did not survive in the absence of oxygen. Embryonic guinea pig brain and serum ultrafiltrate were found to be the most effective vehicles for propagation of the lymphogranuloma virus. There is evidence that the site of activity for this virus is intracellular. Embryonic guinea pig brain cells were maintained in the serum ultrafiltrate diluted with buffered salt solution in good (morphologic) condition for as long as 70 days. Not only could old cultures be successfully inoculated with the virus of lymphogranuloma, but high titres could be maintained over extended periods. PMID- 19870940 TI - THE SELECTIVE ACTION OF SULFANILAMIDE ON THE PARASITES OF EXPERIMENTAL MALARIA IN MONKEYS IN VIVO AND IN VITRO. AB - It was found that with mixed malaria infections in the same experimental animal sulfanilamide eradicates a virulent P. knowlesi infection, leaving the animal with a milder chronic P. inui infection. Determinations of the metabolic activity of the two parasites in vitro showed that P. knowlesi consumed approximately six times more oxygen than P. inui. The addition of sulfanilamide in concentrations less than that necessary to effect a cure almost completely inhibited the respiration of P. knowlesi parasites in vitro, while the same concentrations of the drug against the same number of P. inui parasites had no apparent effect. PMID- 19870941 TI - PERMEABILITY OF THE HUMAN PLACENTA TO ANTIBODIES : A QUANTITATIVE STUDY. AB - The ratio of the titers of various antibodies, namely, hemagglutinins and syphilitic reagin, in the maternal blood to that of the corresponding antibody in the cord blood was found to be relatively constant, falling somewhere between 8 and 16. This figure may be considered the "index of permeability" of human placenta to antibodies, or the coefficient of distribution of antibodies between maternal and cord blood. The possible application of these findings to the study of the placental permeability to sensitizing antibodies (or reagins) is discussed. PMID- 19870942 TI - A CRYSTALLINE PRESSOR SUBSTANCE (ANGIOTONIN) RESULTING FROM THE REACTION BETWEEN RENIN AND RENIN-ACTIVATOR. AB - 1. Renin reacts with renin-activator to form a strong pressor substance which is heat-stable, water- and alcohol-soluble, fluorescent, acid-stable, and alkali labile. It is a reducing substance and is destroyed by strong oxidizing substances. It forms crystalline salts with oxalic and picric acids. The color reaction for arginine is the only one found to be strongly positive. It is suggested that this substance be called angiotonin. 2. Angiotonin produces a sharp, immediate rise in arterial pressure when injected intravenously. Pithing and dissipation of the anesthetic appear to increase the response. Tachyphylaxis occurs, in contrast to renin, only after many single doses. 3. The responses to adrenaline and angiotonin do not parallel one another. Cocaine, atropine, and stilbestrol do not affect the pressor action of angiotonin. Suprarenalectomy in brief experiments is also without effect. 4. Maximal amounts of angiotonin result when the proportion between renin and activator is roughly 3 to 100. This is not a stoichiometric relationship in the chemical sense. The temperature suitable for good yields is about 38 degrees C., and the time of reaction from 10 to 20 minutes. 5. Renin destroys angiotonin when incubated with it. 6. Angiotonin causes marked contraction of intestinal segments of rabbits without reducing their rhythmic motion. It sensitizes the intestine to further doses of angiotonin and alters the intestine such that renin-activator contracts it. Angiotonin also constricts the vessels of a rabbit's ear perfused with blood or Ringer's solution. PMID- 19870943 TI - A SOLUBLE ANTIGEN OF LYMPHOCYTIC CHORIOMENINGITIS : II. CHARACTERISTICS OF THE ANTIGEN AND ITS USE IN PRECIPITIN REACTIONS. AB - The soluble antigen of lymphocytic choriomeningitis which is readily separable from the virus is a relatively stable substance and appears to be of a protein nature. A specific precipitin reaction can be demonstrated when immune serum is added to solutions of antigen which have been freed of certain serologically inactive substances. The complement-fixation and precipitation reactions which occur in the presence of immune serum and non-infectious extracts of splenic tissue obtained from guinea pigs moribund with lymphocytic choriomeningitis seem to be manifestations of union of the same soluble antigen and its antibody. On the other hand, the antisoluble substance antibodies and neutralizing substances appear to be different entities. PMID- 19870944 TI - CHEMICAL AND IMMUNOLOGICAL STUDIES ON THE AGENT PRODUCING LEUKOSIS AND SARCOMA OF FOWLS. AB - The activity of the agent producing sarcoma or leukosis in material deposited by high speed centrifugation is the same as that of the original crude extracts. Material sedimentable at high speed containing approximately 10(-5) mg. N produces tumors at the site of injection. Small quantities of material sedimentable at high speed are present in normal chicken sera, and about twice as much in leukemic sera (strain 1). Normal chicken and mouse spleens and all other human and mouse tissues examined contain large amounts of material sedimentable at high speed. Extraction of leukemic blood cells with saline yields little additional virus. The washed cells readily produce leukosis even after irradiation with amounts of x-rays sufficient to destroy the leukemic cells but not the virus. Freezing at -60 degrees C. preserves the activity of the high speed deposits for at least 6 months. Addition of 5 per cent of saturated Na(2)SO(4) solution slightly delays deterioration of high speed deposits in the ice box. Most of the agent measured by inoculation of chickens and the fraction sedimentable at high speed measured by its nitrogen content is precipitated by one-third saturation with sodium sulfate. PMID- 19870945 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : X. THE OXYGEN CONSUMPTION OF THE ISCHEMIC KIDNEY. AB - The consumption of oxygen by slices of renal tissue of the rabbit was studied by means of the Warburg manometric method. The ischemic kidney of the rabbit shows a definite diminution of oxygen consumption, compared with the normal kidney. PMID- 19870946 TI - AN ELECTROPHORETIC STUDY OF NEPHROTIC SERA AND URINE. AB - The electrophoretic patterns of the sera and urine of two cases of lipoid nephrosis have been obtained and have been compared with a typical pattern of normal serum. The patterns of the pathological sera deviated widely from the normal, indicating relatively low albumin and high globulin content. The comparison of the patterns of nephrotic sera cleared by centrifugation and by ether extraction shows that a large portion of the beta globulin consisted of a labile lipo-protein. The pattern of the nephrotic urine proteins resembled that of normal serum, with, however, significant differences. PMID- 19870947 TI - APPARATUS FOR FREEZING AND DRYING VIRUS IN LARGE QUANTITIES UNDER UNIFORM CONDITIONS. AB - 1. The apparatus described was designed for the desiccation under uniform conditions of large quantities of yellow fever virus in the frozen state. 2. Several hundred cubic centimeters of virus material, distributed in small containers, have been desiccated simultaneously to almost complete dryness and with no appreciable loss of infectivity. 3. Good keeping qualities of the virus activity are insured by sealing the containers either while evacuated or after filling with dry nitrogen. PMID- 19870948 TI - CARDIAC LESIONS RESEMBLING ASCHOFF BODIES IN RABBITS. AB - Cardiac lesions, resembling those of human rheumatic fever, have been observed in rabbits during the course of a seemingly spontaneous epizootic. PMID- 19870949 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : IV. INFECTION IN THE MOUSE WITH FRESH AND FIXED VIRUS. AB - A fresh strain of equine encephalomyelitis virus is infectious for adult mice in high dilutions by all modes of peripheral inoculation. A fixed strain has very limited invasive power when injected peripherally unless virus is placed in fairly close contact with nerve cell bodies, as in the intranasal or intraocular routes. For fixed virus the effectiveness of the mode of inoculation may be graded in the following descending order: intracerebral, intraocular and intranasal, intravenous, intraperitoneal, intramuscular, subcutaneous. Fixed virus has a very limited power of invading the central nervous system along the axones of peripheral nerves even when injected directly into the nerve. Infants are more susceptible to infection than are adults. But even for infants, intraperitoneal inoculation with fixed virus is significantly less effective than similar inoculations with fresh virus. Brain trauma does not increase the effective titer of fresh or fixed viruses but may shorten the incubation period for fresh virus. With fixed virus injected intramuscularly, a pronounced facilitating effect may be produced by the simultaneous intraperitoneal injection of 0.20 to 0.25 cc. of 50 per cent glycerine. Other irritants tried are without effect. PMID- 19870950 TI - THE SIGNIFICANCE OF THE SYNOVIAL VILLUS AND THE CILIARY PROCESS AS FACTORS IN THE LOCALIZATION OF BACTERIA IN THE JOINTS AND EYES OF RABBITS. AB - 1. Histological examination of sections of the eyes and joints of large numbers of rabbits injected with hemolytic streptococci has clearly demonstrated that when arthritis or cyclitis occurs, the synovial villi and ciliary processes are the most frequent and usually the primary sites of inflammation. 2. By special methods for demonstration of bacteria, it has been shown that bacteria which found lodgement in either an eye or a joint were demonstrable first in the vessels of ciliary processes or synovial villi. 3. A localized synovitis or iridocyclitis is brought about by the localization of bacteria in the synovial villus and ciliary process. 4. These experiments, which give a clearer insight into the pathogenesis of infectious arthritis and iritis, explain why both may occur in association with certain infectious diseases. PMID- 19870951 TI - THE HYDROLYSIS OF HYALURONIC ACID BY BACTERIAL ENZYMES. AB - An improved method is described for preparing the enzyme which hydrolyzes the polysaccharide acid contained in vitreous humor, umbilical cord, synovial fluid, and the mucoid phase of group A hemolytic streptococci. Preparations have been obtained from pneumococci, group A hemolytic streptococci, Clostridium welchii, and from splenic tissue, which display the same specific activity. Evidence is presented to show that the hydrolytic enzyme is not the same as that responsible for the lysis of pneumococci. In pneumococci and hemolytic streptococci the major portion of the enzyme is bound to the cell structure. The enzyme from Clostridium welchii is associated with other carbohydrate-splitting enzymes in the culture medium and not with the bacterial cells. It is suggested that the disappearance of the mucoid capsule of group A hemolytic streptococci is due to enzymatic hydrolysis of the acid polysaccharide. The relation between enzyme activity and the virulence and invasiveness of group A hemolytic streptococci is briefly considered. PMID- 19870952 TI - CHARACTERISTICS OF A STRAIN OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS ENCOUNTERED AS A CONTAMINANT IN TISSUE CULTURES OF RABIES VIRUS. AB - A strain of lymphocytic choriomeningitis virus has been encountered, which grows readily in mouse embryo, serum, Tyrode culture media. Its origin is not definitely known but appears to be either the mouse brain tissue or, more probably, the monkey serum. This strain gives clear cut results on filtration tests through Elford membranes, establishing the size of the virus, according to formula, as 33 to 50 mmicro. The strain shows a high and uniform virulence in W Swiss mice. This appears to be due in part, at least, to the age and strain of mice employed for passage and titration. The strain has been found to be more virulent in young than in old mice, especially following intraperitoneal inoculation. Finally, the strain, when given as a vaccine intraperitoneally in amounts as small as 160 intracerebral lethal doses, induces an immunity against subsequent intracerebral inoculations of as much as 10,000 lethal doses. PMID- 19870953 TI - SYMPTOMATIC HERPES, A SEQUELA OF ARTIFICIALLY INDUCED FEVER : INCIDENCE AND C ASPECTS; RECOVERY OF A VIRUS FROM HERPETIC VESICLES, AND COMPARISON WITH A K STRAIN OF HERPES VIRUS. AB - 1. Symptomatic herpes occurred in 190 (46.2 per cent) of 411 patients treated with fever induced by physical methods. 2. Herpes recurred in only 7, or 5.3 per cent, of 131 patients given subsequent fever treatments, suggesting that some immunity develops with the first attack. 3. An acute encephalitis-like syndrome of short duration and without sequelae developed in a group of patients with severe herpes following fever therapy. 4. A filter-passing virus, recovered from herpetic vesicles on patients treated with artificially induced fever, produced a fatal encephalitis in rabbits when inoculated intracerebrally and by corneal scarification. Intranuclear inclusion bodies were observed in corneal epithelial cells and in motor ganglion cells of the brain similar to those observed in rabbits injected with known strains of herpes virus. 5. Four strains of virus that had been recovered from herpetic vesicles appearing on patients subsequent to artificially induced fever were shown by cross-protection tests on rabbits to be immunologically related to the Frank strain of herpes virus. PMID- 19870954 TI - THE THERMAL INACTIVATION TIME AT 41.5 degrees C. OF THREE STRAINS OF HERPES SIMPLEX VIRUS. AB - 1. The thermal inactivation time at 41.5 degrees C. of the H. F. and Frank strains of herpes simplex virus, under the conditions described, was 80 hours. 2. A strain of herpes virus recently recovered from a patient treated with a physically induced fever had a thermal inactivation time of 50 hours at 41.5 degrees C. 3. The neurotropic factor of the H. F. and Frank strains of virus was more resistant to a temperature of 41.5 degrees C. than the dermotropic factor. There was little difference in the thermostability of these two factors of the Go strain. PMID- 19870955 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : XI. THE EFFECT OF EXCISION OF THE CAROTID SINUSES ON EXPERIMENTAL HYPERTENSION PRODUCED BY RENAL ISCHEMIA. AB - Excision of both carotid sinuses, with or without section of cardio-aortic inhibitor fibers, was not followed by a significant change of femoral mean blood pressure from the normal. This procedure did not interfere with the development of hypertension produced by renal ischemia. There was no significant difference between the levels of hypertension due to renal ischemia in animals with both carotid sinuses previously excised and in those with both carotid sinuses intact. In one of three animals with hypertension due to renal ischemia, in which the elevated blood pressure had gradually subsided, there was a slight and only temporary reelevation of pressure after excision of both carotid sinuses. In the other two animals, excision of the carotid sinuses had no effect on the blood pressure. In all three, however, increased constriction of the renal arteries caused significant and persistent reelevation of the blood pressure. The carotid sinus has no demonstrable influence upon hypertension caused by renal ischemia, although in such animals it probably plays the same part in the regulation of blood pressure as it does in normal animals (7). PMID- 19870956 TI - TOXOPLASMIC ENCEPHALOMYELITIS : IV. EXPERIMENTAL TRANSMISSION OF THE INFECTION TO ANIMALS FROM A HUMAN INFANT. AB - 1. Infected material from the brain and spinal cord of an infant suffering from a recently recognized form of granulomatous encephalomyelitis was inoculated into rabbits and mice and produced an experimental disease which was readily transmissible in series. 2. A parasite identical with that in the lesions of the human case was found in the lesions of the experimental animals. 3. The morphology of this microorganism, the course of the disease and the lesions produced in the animals inoculated with it, the wide host range of this parasite, and the results of cross immunity experiments, establish its identity as a Toxoplasma. It is suggested that the microorganism be designated Toxoplasma hominis. 4. The clinical and pathologic features of the infection produced in animals by this Toxoplasma are described. 5. The infection in the infant is the first proved instance of human toxoplasmosis. Since the lesions were confined to the central nervous system the disease is termed toxoplasmic encephalomyelitis. 6. The first experimental transmission of human toxoplasmosis to animals is recorded. PMID- 19870957 TI - ON THE PRESENCE IN SYPHILITIC SERUM OF ANTIBODIES TO SPIROCHETES, THEIR RELATION TO SO CALLED WASSERMANN REAGIN, AND THEIR SIGNIFICANCE FOR THE SERODIAGNOSIS OF SYPHILIS. AB - 1. In confirmation of Gaehtgens, syphilitic human sera give positive complement fixation with cultures of so called T. pallidum (Reiter strain). Syphilitic rabbit sera are equally reactive. Syphilitic human and rabbit sera agglutinate these cultures, often in high titre (Beck). 2. Normal rabbit sera react weakly with the culture to give both agglutination and complement fixation in low titre. Normal human sera, despite the fact that they contain agglutinins in low titre, fail to fix complement with the Reiter strain of cultured spirochetes. Confirming Gaehtgens, the latter reaction is therefore of practical utility for the serum diagnosis of syphilis. 3. When syphilitic serum is heated at 63 degrees C., there is no demonstrable difference in the thermolability of the antibody to spirochetes, and of the reagin which determines the Wassermann and flocculation tests. 4. (a) The absorption of syphilitic serum by spirochetal suspensions removes all reactivity, not only for the spirochetes, but for tissue lipoids (alcoholic beef heart extract) as well; the sera become Wassermann- and flocculation-negative. (b) Absorption of syphilitic serum with tissue lipoids renders the Wassermann and flocculation tests negative, but does not demonstrably change the reactivity of the serum with spirochetes. (c) Rabbits immunized to beef heart lipoid develop spirochetal agglutinins and complement-fixing antibodies (Reiter strain) in high titre. 5. It is concluded that these cultured spirochetes contain antigenic material serologically related to a substance present in mammalian tissue, as well as other antigenic factors not present in such extracts, but equally reactive with syphilitic serum. 6. These findings support the thesis that the primary serologic change in syphilis is the development of antibodies to T. pallidum. The Wassermann and flocculation tests would be explained on the basis that the tissue extracts used as "antigen" in these tests contain one or more substances serologically related to antigenic components of T. pallidum. Similarly, the cultured Reiter strain of spirochete is apparently sufficiently close serologically to T. pallidum to be agglutinated by and to give complement fixation with the antibodies to T. pallidum present in syphilitic serum. 7. Since suspensions of cultured spirochetes contain antigenic factors which react specifically with syphilitic serum, some of which are not present in ordinary Wassermann and flocculation "antigens," they may prove even more valuable than those tissue extracts in the serodiagnosis of syphilis. PMID- 19870958 TI - SEROLOGICAL TESTS FOR HOMOLOGOUS SERUM PROTEINS IN TISSUE CULTURES MAINTAINED ON A FOREIGN MEDIUM. AB - Connective tissue cells (fibroblasts) derived from skeletal muscle of 12 day old chick embryos were cultivated for almost 8 months (35 weekly passages) in rabbit plasma and rabbit embryo tissue juice diluted with Tyrode's solution. When fluids separated from these cultures were tested with immune precipitins developed against chicken serum, they gave positive reactions which showed no tendency to diminish with an increasing number of culture generations. Barring the intervention of unknown precipitable substances, these results indicate that connective tissue can produce proteins which are identical with, or closely related to, serum proteins. The experiments further demonstrated that tissues cultivated in a foreign plasma do not lose their species specificity. PMID- 19870959 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : VII. SKIN SENSITIZATION BY INTRAPERITONEAL INJECTIONS. AB - A method has been described by which sensitization to a simple chemical, picryl chloride (2:4:6 trinitrochlorobenzene), can be satisfactorily attained by means of intraperitoneal injection of the compound when killed tubercle bacilli suspended in paraffin oil were used as adjuvant. Sensitivity of the contact dermatitis type results therefrom. It follows that although skin sensitization of this type is most easily obtained by dermal application this route of administration is no necessary condition for such sensitivity. PMID- 19870960 TI - STUDIES ON THE MOLECULAR WEIGHT OF DIPHTHERIA TOXIN, ANTITOXIN, AND THEIR REACTION PRODUCTS. AB - Purified diphtheria antitoxic horse pseudoglobulin has been prepared which is homogeneous by sedimentation, diffusion, and electrophoresis. Immunologically, however, the preparation contains only 43.5 per cent antitoxin specifically precipitable by toxin. The inactive pseudoglobulin remaining after specific precipitation was found to have the same physical and chemical properties as the original antitoxic pseudoglobulin. Although the molecular weight of antitoxin is the same as that of the normal horse serum globulins, the electrophoretic mobility does differ from those normally present. The molecular weight of diphtheria toxin is 70,000 and of antitoxin is 150,000. From ultracentrifuge studies on the two reactants and on mixtures of toxin and antitoxin in the soluble inhibition zones, the average molecular composition of the specific floccules at certain reference points throughout the equivalence zone and the maximum "valence" of toxin and antitoxin with respect to each other have been calculated. The significance of the results has been discussed in relation to antigen-antibody reactions in general and a possible explanation for the exceptional behavior of the toxin-antitoxin reaction in the region of excess antitoxin has been suggested. PMID- 19870961 TI - ANTI-EGG ALBUMIN ANTIBODY IN THE HORSE. AB - The reaction between three times recrystallized egg albumin and its antibody in the horse has been studied. The reaction exhibits a behavior typical of the Ramon diphtheria flocculation reaction. PMID- 19870962 TI - A QUANTITATIVE THEORY OF THE PRECIPITIN REACTION : VII. THE EGG ALBUMIN-ANTIBODY REACTION IN ANTISERA FROM THE RABBIT AND HORSE. AB - 1. In two rabbits subjected to prolonged injections with crystalline egg albumin the antibodies in one showed progressive changes such as noted in an earlier paper; the antibodies in the other did not. 2. The significance of this behavior in the production of sera for therapeutic use is pointed out. 3. Quantitative studies are reported on the low grade or incomplete antibody present in the early stages of immunization of a horse with egg albumin. 4. Quantitative studies on the flocculating antibody from later bleedings from the horse are given, and the dissociation of the soluble pre-zone compounds by rabbit anti-egg albumin is studied. Rough velocity estimations are reported. 5. The bearing of the findings on the mechanism of precipitin and flocculation reactions and of the Danysz effect is discussed in terms of the union of multivalent antigen with multivalent antibody. PMID- 19870963 TI - BLOOD PLASMA PROTEIN PRODUCTION AND UTILIZATION : THE INFLUENCE OF AMINO ACIDS AND OF STERILE ABSCESSES. AB - When blood plasma proteins are depleted by bleeding with return of the washed red blood cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal low protein diet. These dogs are clinically normal. Introduction of variables into their standardized life gives insight into the production of plasma protein. Casein retested as the basal protein in the ration may show high yield of plasma protein, equal to 33 per cent of the protein fed. This equals the potency of liver protein (17 to 33 per cent) and approaches the utilization of plasma protein by mouth (40 per cent). Zein has no effect upon plasma protein regeneration but when it is supplemented with cystine, tryptophane, lysine, and glycine, there is a doubling of the liver basal plasma protein production and a retention of the fed protein nitrogen. Threonine does not modify the above reaction. Liver protein supplemented with cystine, leucine, glutamic acid, and glycine in the basal diet yields double the amount of new formed plasma protein compared with liver alone. This combination is then as potent as plasma protein itself when given by mouth-40 per cent utilization. Tyrosine or lysine, arginine, and isoleucine do not modify the above responses. Methionine is not as effective as cystine in supplementing gelatin and tyrosine to produce plasma protein. Cystine, leucine, and glutamic acid appear to be of primary importance in the building of new plasma protein in these experiments. Plasma protein formation is dependent upon materials coming from the body reserve and from the diet. Given an exhaustion of the reserve store there is very little plasma protein produced during a protein fast (3 to 6 gm. per week). A turpentine abscess does not modify this fasting plasma protein reaction. Homologous plasma given by vein will promptly correct experimental hypoproteinemia due to bleeding. It will maintain nitrogen equilibrium and replenish protein stores. Even during hypoproteinemia plasma protein may promptly pass out of the circulation to supply body needs for protein. Perhaps the most significant concept which derives from all these experiments is the fluidity of the body protein (including plasma protein)-a ready give and take between the protein depots-a "dynamic equilibrium" of body protein. PMID- 19870964 TI - THE INFLUENCE OF NITROGEN RETENTION UPON THE REGENERATION OF PLASMA PROTEINS. AB - 1. Because of the clinical observation that the capacity to form new plasma proteins is sometimes impaired in cases of nephritis (2), experiments were performed to determine whether the impaired function in the nephritic is related to nitrogen retention. 2. These experiments consisted of producing renal injury by injecting uranium nitrate into standard hypoproteinemic dogs and comparing the rate of blood plasma protein formation under these conditions of nitrogen retention with that in the uninjured dog. 3. Despite elevations in blood N.P.N. to more than ten times normal, no interference with plasma protein formation was observed. These elevations in N.P.N. affected principally the urea and undetermined fractions. 4. Neither elevation in N.P.N. nor proteinuria per se appears to have any effect upon plasma protein production. Possibly the deficient production of plasma proteins in the nephritic is related to a more general disturbance in metabolism in which the elevation in N.P.N. is secondary. PMID- 19870965 TI - FAMILIAL MAMMARY TUMORS IN THE RABBIT : IV. THE EVOLUTION OF AUTONOMY IN THE COURSE OF TUMOR DEVELOPMENT AS INDICATED BY TRANSPLANTATION EXPERIMENTS. AB - A series of experiments is described in which fragments derived from two mammary tumors of distinct types were transferred at different developmental stages to the anterior chamber of the eye of normal rabbits. It was found that the ability to survive and to grow progressively after transplantation was not immediately related to anaplastic cellular changes. On the other hand, there existed a definite correlation between the success of transplantation and the morphological relationship of tumor cells and the normal cells of the host. Transplantation to normal animals could not be effected during stages of local tissue invasion but was successfully performed as soon as the tumor cells manifested the ability to invade foreign tissues or to metastasize in the spontaneous host. It was concluded, therefore, that neither anaplasia nor local tissue invasion represented autonomy but, rather, stages in its development and that the final attainment of this condition was only evidenced by metastasis or by invasion in foreign tissues. The tumors were successfully transplanted to normal animals during this series of experiments and have been carried by serial transfer to the present time. The most outstanding feature in the transplantation of the papillary type tumor was the marked difference in susceptibility exhibited by the two sexes. The acinar type tumor was distinguished by high transplantability, an extremely rapid growth rate and early regression. PMID- 19870966 TI - THE RESTORATION OF LOST ORGAN TISSUE : THE RATE AND DEGREE OF RESTORATION. AB - 1. When half of the total kidney, suprarenal, ovarian, or testicular mass is removed the rate of growth of the remaining half is independent of the rate of growth of the organ at the time of removal. 2. The removal of half of the prostate, or seminal vesicular tissue, or of one uterine horn is not followed by any appreciable growth of the part that remains. 3. The rate of restoration of renal, ovarian, testicular, and suprarenal tissue after removal of half of these organs is at first very rapid, but quickly decelerates and at about 40 days after the removal there is a complete cessation of growth. 4. In none of these organs is all the lost tissue restored. In the testicle the 50 per cent left increases to 56 per cent and in the kidney, suprarenal, and ovary to 70 per cent of the original amount before operation. PMID- 19870967 TI - A DISTINCTIVE SUBSTANCE ASSOCIATED WITH THE BROWN-PEARCE RABBIT CARCINOMA : I. PRESENCE AND SPECIFICITY OF THE SUBSTANCE AS DETERMINED BY SERUM REACTIONS. AB - A substance is regularly present in saline extracts of the Brown-Pearce rabbit carcinoma growth which is capable of fixing complement specifically in mixture with the sera of certain rabbits bearing the tumor or in which this has recently retrogressed, as the foregoing experiments have shown. The substance was not demonstrable in extracts of the normal tissues, virus papillomas, or uterine cancers of rabbits, nor in extracts of rabbit tissues infected with certain viruses (vaccine virus, Virus III, fibroma virus). The sera of normal rabbits, of those immune to a variety of infectious diseases, including syphilis, vaccinia, fibromatosis, and Virus III, and of others with uterine cancers or virus-induced papillomas, failed to fix complement specifically in mixture with extracts containing the antigen of the Brown-Pearce tumor. The significance of the findings will be discussed in the succeeding paper, after consideration has been given to some of the properties of the serologically active material derived from the Brown-Pearce tumor. PMID- 19870968 TI - A DISTINCTIVE SUBSTANCE ASSOCIATED WITH THE BROWN-PEARCE RABBIT CARCINOMA : II. PROPERTIES OF THE SUBSTANCE: DISCUSSION. AB - The serologically active substance of the Brown-Pearce tumor, a complement-fixing antigen, differs notably from certain other tissue antigens (the Wassermann, Forssman, and organ- and species-specific tissue haptens, for example) in the fact that it is not effective after alcoholic extraction of the tissue containing it. Like many of the proteins and viruses it is in-activated upon heating to 65 degrees C. for 30 minutes; and, like them as well, its activity is lost upon treatment with acid (to pH 4.5 or lower) or alkali (to pH 11.5 or higher). Filtration and centrifugation experiments disclosed the fact that the antigen of the Brown-Pearce tumor passed readily through collodion membranes with average pore diameters of 383 mmicro and more, but was retained completely by those with average pore diameters of 348 mmicro and less. It was thrown down completely or almost completely upon centrifugation at 20,000 R.P.M. for one hour. The findings indicate that the Brown-Pearce tumor antigen has a large and nearly uniform particle size and weight,-as large as that of many of the viruses. They differentiate it sharply from the generality of "soluble antigens.rdquo; Upon direct comparison, the complement-fixing antigen of the Brown-Pearce tumor was found to be similar in a number of its general traits to the serologically active substance of the virus-induced papillomas of rabbits, which in turn is intimately associated or identical with the virus responsible for the papillomas. Extracts of the Brown-Pearce tumor containing the serologically active substance in quantity have given rise to no lesions, however, upon injection into normal or tarred rabbits. The significance of the findings is discussed. PMID- 19870969 TI - SOME CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA. AB - Treatment of elementary bodies of vaccinia with dilute solutions of sodium hydroxide resulted in the extraction of certain soluble materials accounting for half of the dry weight of the virus. Elementary bodies contained about 0.4 per cent inorganic phosphorus, practically all of which occurred in the form of a nucleoprotein containing thymus nucleic acid. In addition, a substance was recovered that reacted with S antibodies. From past experience one is led to believe that S antigen, as ordinarily encountered, is a protein which is not in combination with nucleic acid. PMID- 19870970 TI - A LATENT VIRUS IN NORMAL MICE CAPABLE OF PRODUCING PNEUMONIA IN ITS NATURAL HOST. AB - 1. A virus capable of producing fatal pneumonia in mice has been isolated repeatedly from the lungs of certain apparently healthy mice. Not all mice carry the virus. It was obtained only from mice supplied by three breeders although mice from eight different sources were studied. 2. The virus was avirulent as it occurred in normal mouse lungs and became virulent only after serial mouse lung passage. It was strictly pneumotropic for mice and produced pneumonia when given intranasally but showed no evidence of infection when given by other routes. The virus was non-infectious for ferrets and did not become pathogenic for this species after numerous serial passages. It was also non-pathogenic for rabbits, guinea pigs, rhesus monkeys, voles, deer mice, skunks, wood-chucks, opossums, and Syrian hamsters. 3. All strains of the virus which have been tested have been immunologically identical, as indicated both by cross immunity and cross neutralization tests in mice. 4. The virus was antigenic both in mice and in rabbits and was readily differentiated from viruses of human influenza and of swine influenza by means of either cross immunity or cross neutralization tests. 5. The virus was also neutralized by about 30 per cent of normal human sera tested. 6. The virus was extremely labile, and suspensions prepared in saline or broth became inactivated within a few hours at room temperature. The addition of normal horse serum to the virus suspensions, however, exerted a definite stabilizing effect. 7. Ultrafiltration results indicated that the virus particles have a diameter of about 100 to 150 millimicrons. 8. Evidence is presented which indicates that this virus is different from other viruses which various investigators have found in normal mouse lungs. PMID- 19870971 TI - PASSIVE IMMUNITY IN AVIAN MALARIA. AB - The effect of therapy with immune serum has been studied in thirty-two cases of Plasmodium circumflexum infection, all of them produced by blood inoculation. Eighteen of these cases never showed parasites, and seven others developed infections which were definitely milder than those of the controls. The therapeutic serum was in all cases obtained from chronic cases which had previously been superinfected to raise the immune titre. It seems justifiable to conclude that: 1. Passive immunity can be conferred in avian malaria, at least when caused by Plasmodium circumflexum just as it can be in certain types of monkey malaria, and perhaps in human malaria as well. 2. Whatever the nature of the protective substances present in the serum of chronic cases may be, they are present in very low concentration. Their concentration can be raised by superinfection, however. These substances may be strain-specific or species specific, but the results of these experiments do not give any clear-cut answer to this question. 3. Serum therapy previous to infection seems to be more effective than when given afterward. 4. The administration of normal serum or even of physiological saline in a dosage comparable to that employed with the immune serum used in these experiments produced similar macroscopic changes in the size of the spleen. 5. Agglutination of cells parasitized by Plasmodium circumflexurn when mixed with immune serum was observed. PMID- 19870972 TI - GROWTH INHIBITION BY SUBSTANCES IN LIVER. AB - Certain tissue constituents inhibitory to cell growth, extracted from liver, are described. The findings indicate that inhibitory material is adsorbed to colloids in the native state and is freed from them by alcohol extraction. One inhibitor, ethanolamine, has been isolated. This substance differs in its biological properties from the bulk of the inhibitory material present in liver. Progress in purification of other inhibitors is described, and it is shown that inhibition by these extracts is not correlated with surface activity or with the presence of pigmented constituents. The inhibitors have common properties which suggest that they are of physiological significance in the regulation of growth: action over a wide range of concentrations at which other cell functions are undamaged; reversibility of action; presence in adult liver in concentrations near those which inhibit growth in vitro, while in embryo liver they are found only in much lower concentrations. PMID- 19870973 TI - STUDIES OF THE INFECTIOUS UNIT OF MYXOMA. AB - The virus of infectious myxoma of rabbits behaves on inoculation into the skin as if infection were initiated by a single viral particle. PMID- 19870974 TI - ON CROSS REACTIONS OF EGG ALBUMIN SERA. AB - Experiments are presented on the cross reactions of hen egg albumin immune sera with egg albumins of other species by means of exhaustion with heterologous proteins and by inhibition tests. From the results it can be concluded that the sera contain multiple, qualitatively distinct antibodies. For this, two not mutually exclusive explanations come into consideration: the presence in proteins of a number of different, perhaps similar, complex determinants, and the fact, established by previous results, that one antigenic grouping can call forth the formation of diverse antibodies. It is inferred that cross reactions between proteins of kindred species are ascribable, in general, to similarity in determinant structures, and not to the distribution of identical determinant groups among the related proteins. PMID- 19870975 TI - ANTIBODY FORMATION IN A TUBERCULOUS LESION AT THE SITE OF INOCULATION. AB - Complement fixing antibody in animals injected with heat killed tubercle bacilli in oil appears earlier in the lesion at the site of injection than in the blood serum. Complement fixing antibody in an extract prepared by suspending one part by weight of tissue from the local site in five parts of saline is in general in higher concentration than in the blood, for a period of approximately 3 weeks following injection. After this time the serum may show the higher titre. The titre of antibody at the site of injection tends to increase with the quantity of heat killed bacilli injected into the skin, up to a definable maximum. No evidence was found to support the opinion that local accumulation of antibody was caused by fixation of antibody contained in the serum and produced elsewhere in the body, for extracts of lesions produced by the injection of paraffin oil, old tuberculin, and cod liver oil showed no demonstrable antibody, or at most a very low titre, even when the serum titre was high. After reinjection of heat killed tubercle bacilli in oil into rabbits with antibody in the serum, antibody did not appear in the local lesion any earlier than in normal animals similarly injected. These observations give evidence that antibody is formed in the skin at the site of injection of tubercle bacilli. PMID- 19870976 TI - CANCERS DERIVING FROM THE VIRUS PAPILLOMAS OF WILD RABBITS UNDER NATURAL CONDITIONS. AB - The naturally occurring virus papillomas of western cottontail rabbits become malignant occasionally. The cancers derive from the papilloma cells, that is to say from elements already rendered neoplastic by the virus and still infected therewith. Papillomas produced with the virus in jack rabbits and snowshoe rabbits become cancerous in the same way but much more frequently, as is the case in domestic rabbits also. To all three species the virus is foreign. The character of the cancers of the wild rabbits is described and the relation of the virus to them discussed on the basis of experimental findings. The facts support the view that the cancers result from virus variation, this in many instances being but slight. PMID- 19870977 TI - ANGIOTONIN-ACTIVATOR, RENIN- AND ANGIOTONIN-INHIBITOR, AND THE MECHANISM OF ANGIOTONIN TACHYPHYLAXIS IN NORMAL, HYPERTENSIVE, AND NEPHRECTOMIZED ANIMALS. AB - 1. Angiotonin does not exert its vasoconstrictor effect in the absence of a substance contained in red blood cells and serum which we have called "angiotonin activator." A fraction has been separated from blood in which angiotonin activator is concentrated. It contains little or no reninactivator. 2. Repeated intravenous injections of angiotonin into animals causes the pressor response gradually to lessen and finally to disappear (the phenomenon of tachyphylaxis), but much more slowly than when renin is injected. When the response to angiotonin is abolished, renin also fails to act. Large doses of renin reduce and finally abolish the responsiveness to angiotonin. Exhaustion of renin-activator in the blood abolishes the response to renin without abolishing the response to angiotonin. 3. Blood from animals made tachyphylactic by infusion of angiotonin contains greatly reduced amounts of angiotonin-activator. An inhibitor also appears in the blood. 4. Bilateral nephrectomy prolongs and greatly enhances the rise of arterial pressure following injection of angiotonin and renin. The enhancement reaches a maximum in from 24 to 30 hours after operation. Blood from these animals exhibits greatly increased ability to activate angiotonin and renin when tested in isolated perfused organs. Large amounts of angiotonin are required to reduce the amount of activator in their blood. Renin-activator is simultaneously but little affected. 5. Tranfusion of blood from an animal made tachyphylactic to angiotonin into a nephrectomized dog reduces the response of the latter to angiotonin. Angiotonin when added to the blood of the recipient of the transfusion and perfused through a rabbit's ear also exhibits greatly reduced vasoconstrictor action. 6. Transfusion of normal blood in large amounts into nephrectomized or hypertensive dogs reduces the recipient's response to renin. If renintachyphylaxis is established in the donor, transfusion abolishes the response to renin in the recipient. The blood from such animals exhibits greatly reduced vasoconstrictor properties when perfused through an isolated organ with renin or angiotonin. 7. Renin-tachyphylactic or normals dog's blood does not reduce arterial pressure elevated by a single injection of renin into nephrectomized dogs. 8. Nephrectomized dogs exhibit the greatest pressor response to infusion of angiotonin and renin, normal animals the least, and hypertensive animals about midway between. PMID- 19870978 TI - TYPE-SPECIFIC ANTIGENS, M AND T, OF MATT AND GLOSSY VARIANTS OF GROUP A HEMOLYTIC STREPTOCOCCI. AB - 1. Two qualitatively different type-specific antigens, designated M and T, have been found present in matt variants of group A hemolytic streptococci, but only one of these, the T antigen, occurs in the degraded glossy variant. 2. The protein nature of the M antigen, present in matt variants only, has been demonstrated in previous work, but the chemical characteristics of the newly recognized antigenic factor, T, present in both variants, have not been determined. This T factor is identified only by its immunological reactions. It is unknown whether the two type-specific antigenic factors, M and T, occur as separate chemical entities in the matt variant or in conjugation. 3. Antibody to the type-specific protein, M, appears responsible for the M precipitin reaction, for type-specific protection, and, as a rule, for part of the type-specific agglutination of matt variants, but in type 1 it does not cause agglutination. 4. Antibody to the second type-specific antigen, T, seems to be solely responsible for type-specific agglutination of the glossy form and to play a large role in type-specific agglutination of the matt form, but apparently it is not involved in protection. This T antibody causes all of the type-specific agglutination of type 1. Consequently, type 1 matt and glossy variants agglutinate and absorb agglutinin alike, and antisera to both are identical in content of type-specific agglutinin though they differ in respect to M antibody. 5. Recognition of the principle underlying type-specific agglutination of glossy variants makes it possible to suggest, with certain reservations, the use of glossy variants for type classification by agglutination. These variants are suitable for preparing type-specific agglutinating antisera, and they form stable suspensions for use in the reaction. Improved methods are needed for deriving glossy from matt variants. PMID- 19870979 TI - THE SIGNIFICANCE OF M AND T ANTIGENS IN THE CROSS REACTIONS BETWEEN CERTAIN TYPES OF GROUP A HEMOLYTIC STREPTOCOCCI. AB - In any one strain the occurrence of the previously recognized type-specific protein, M, is usually completely correlated with the presence of the recently recognized type-specific antigen, T. Strain C203 is exceptional in having the T substance of type 1 as well as the two type-specific antigens, M and T, characteristic of type 3. It does not have the M antigen of type 1. While other strains with similar antigenic peculiarities have not been encountered, it is probable that they occur, and the existence of such anomalies must be suspected when unusual serological reactions occur. PMID- 19870980 TI - ON GROUP SPECIFIC A SUBSTANCES : IV. THE SUBSTANCE FROM HOG STOMACH. AB - An investigation is presented on the A substance contained in swine stomach. Preparations made by several procedures, and largely consisting of carbohydrates, were found by means of the ninhydrin method of Van Slyke and his colleagues to contain amino acids accounting for the bulk of the non-hexosamine nitrogen. As a working hypothesis the idea is advanced that amino acid structures can play a role in the serological specificity of haptens consisting predominantly of polysaccharides. PMID- 19870981 TI - PROTEIN CONSUMPTION AND THE RESTORATION OF LOST ORGAN TISSUE. AB - 1. At all levels of immediate protein consumption, from almost none to excessive amounts, the degree of growth of the single kidney, suprarenal, and ovary left after removal of one of each of these organs is the same up to 5 days after the operation. 2. On a 1 per cent protein diet there is no growth of the remaining organs after the first 5 days. 3. On diets containing from 10 per cent to 57 per cent of protein there is no definite relation between the level of protein consumption and the rate and degree of growth from 5 to 40 days after the operation. 4. When rats are given a 1 per cent protein diet for 10 days before the operation a continuation of this diet reduces the initial growth of the remaining organs and leads to a cessation of growth after the first 2 days. PMID- 19870982 TI - AMINO ACIDS AND HEMOGLOBIN PRODUCTION IN ANEMIA. AB - Certain individual amino acids when given to standard anemic dogs cause an increase in new hemoglobin production. Occasional negative experiments are recorded. Glycine, glutamic acid, aspartic acid, cystine, histidine, phenylalanine, and proline when given in 1 gm. doses daily for 2 weeks, increase hemoglobin output on the average 23 to 25 gm. above the control level. This reaction amounts to 25 to 30 per cent of the new hemoglobin produced by the feeding of 300 gm. liver daily for 2 weeks-a standard liver test. Alanine, valine, isoleucine, and arginine in the same dosage increase the hemoglobin output on the average 13 to 17 gm. per 2 weeks over the control level. Leucine, methionine, lysine, tryptophane, and tyrosine fall in a middle group with hemoglobin output of about 20 gm. Isovaleric acid, beta-hydroxybutyric acid, glutaric acid, and asparagine have shown positive effects and the butyrate is unusually potent for hemoglobin production (Table 2). The isomeric and dl synthetic forms of the amino acids are as effectively utilized in this reaction as are the natural forms. PMID- 19870983 TI - THE SPECIFICITY OF OXIDIZED AND REDUCED PROTEINS OF THE OCULAR LENS. AB - Oxidized and reduced proteins were prepared from the ocular lenses of sheep, swine, chicken and fish (pike). The proteins were prepared under conditions designed to avoid denaturation and to produce relatively pure compounds. Serologic studies revealed that species specificity is demonstrable in the proteins from chicken and fish lenses, but in the more closely related species (swine and sheep) this characteristic is not so evident. Serologic differences may be detected in the lens preparations from a single species, depending on the redox state of the protein. PMID- 19870984 TI - AN HETEROPHILE FACTOR IN RAGWEED POLLEN. AB - 1. There is serological evidence that ragweed pollen antigen contains a factor which causes an increased hemolysin titre for sheep cells, when injected into rabbits. 2. It remains questionable whether the antigen absorbs normal rabbit hemolysins. It does, however, absorb anti-ragweed hemolysins, as demonstrated by hemolysis inhibition test. 3. Dilution and lyophilization (Mudd-Flosdorf method) of antigen-antibody mixture shows that one hemolytic unit of anti-ragweed rabbit serum combines with 0.00007 mg. of low ragweed total N. There were three zones of inhibition of hemolysis demonstrated. 4. The immune hemolysins are completely absorbed by sheep cells and by Forssman antigen, but not by human cells of groups A or B. 5. Although Forssman antigen was able to absorb anti-ragweed hemolysin, the ragweed antigen was not able to absorb Forssman antibody. 6. Human ragweed sensitive sera from 22 cases with hay fever, before treatment, did not show increased titre of heat-labile or heat-stable hemolysin. There was no change after treatment. 7. Among the human cases there were encountered blood groups A, B, and O. Heat-labile hemolysins for sheep cells were present in nineteen of the twenty-two sera regardless of blood groups. PMID- 19870985 TI - SOME PROPERTIES OF THE ENCEPHALOPATHIC AGENT IN PRIMATE BONE MARROW (THE GORDON AGENT). AB - The nature of the encephalopathic agent present in monkey bone marrow has been investigated. It is readily soluble at a pH of 7.4, as well as at the low pH of 2.0 and 3.0. The point of minimal solubility is pH 4.2. Heat inactivation is produced by a temperature of 75 degrees C., acting for 15 minutes. The agent is digested by pepsin. It exhibits a slight degree of sedimentation with the air driven centrifuge. It is non-dialyzable. It is precipitated from solution (pH 7.4) by ammonium sulfate, over a range of 0.4 to 0.8 saturation. These findings all suggest that the agent is a protein. No immunological reactions could be elicited. PMID- 19870986 TI - PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR : XIV. RELATION BETWEEN A TUMOR NUCLEOPROTEIN AND THE ACTIVE PRINCIPLE. AB - 1. The tumor-producing fraction, isolated from Chicken Tumor I by means of differential centrifugation at high speed, has been investigated as regards its power to absorb ultraviolet light. A characteristic absorption spectrum was found, with a maximum at lambda2575. The absorbing power of the material in that region was largely due to the presence of nucleic acid, or of a closely related compound. 2. Inactivation of the purified tumor fraction with ultraviolet light depressed the absorbing power of the material, especially in the region of 2600 2500A. These changes were those which nucleic acid would present under the same conditions. 3. Inactivation of the tumor agent with acid or alkali was accompanied by decomposition of the tumor nucleoprotein and passage of free nucleic acid into solution. 4. Partial or complete inactivation of the tumor agent by heat, at 50 degrees or 65deg;C., was attended by liberation of nucleic acid of low molecular weight. 5. The parallelism between tumor-producing activity and the integrity of the tumor ribonucleoprotein suggests that the nucleoprotein may be an essential part of the active principle. PMID- 19870987 TI - A TYPE-SPECIFIC ANTIGENIC PROTEIN DERIVED FROM THE STAPHYLOCOCCUS. AB - Chemical extraction of lyophilized and ground staphylococci of type A has yielded a type-specific, antigenic fraction which has been shown to be protein. In precipitin tests this fraction reacts in high dilution with homologous immune sera prepared by the injection of animals either with the whole organisms or with the protein itself. Reactions with sera prepared against heterologous types of staphylococci occur only in low dilutions. The type specificity of this fraction has been found to be entirely independent of that of the type-specific carbohydrate described by Julianelle and Wieghard. PMID- 19870988 TI - INFECTIVITY AND IMMUNITY RESULTING FROM THE INJECTION OF POLIOMYELITIS VIRUS BY THE INTRACUTANEOUS ROUTE. AB - The infectivity of poliomyelitis virus by the intracutaneous route occurs in certain strains but is not a constant character. The inconsistency of skin infectivity tests indicates that there is some property yet unknown which influences this characteristic. Strains of poliomyelitis virus vary in the degree of immunity produced in experimental monkeys injected with active virus by the intracutaneous route and subsequently tested for resistance by intranasal injections. The variation has no relation to the virulence of the strain. Further investigation on the intranasal route of injection should be carried on so that this method may be used with greater assurance in immunity tests, and also in other procedures of poliomyelitis experimentation. PMID- 19870989 TI - THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : III. THE SURVIVAL OF VARIOLA AND VACCINIA VIRUSES IN THE LUNGS OF MICE PREVIOUSLY INFECTED WITH VARIOLA. AB - Recovery from the transient pulmonary reaction which accompanies the nasal instillation of variola virus in mice was followed by a measurable protection against the homologous virus and also against vaccinia. Variola virus which regularly survived in the lung of normally susceptible mice through the 5th day was noticeably reduced in titer on the 3rd day in the lung of recovered animals, and usually eliminated by the 5th day. Vaccinia virus produced a less severe systemic reaction in recovered mice and its titer in the lung was significantly reduced on the 5th day. The residence of both viruses in the lung of recovered mice was attended by pathological changes, visible macroscopically. PMID- 19870990 TI - THE INACTIVATION OF THE VIRUS OF EPIDEMIC INFLUENZA BY SOAPS. AB - The capacity of certain fatty acids at pH 7.5 to inactivate the virus of epidemic influenza has been demonstrated. Most effective of these are oleic, linolic, and linolenic acids. Studies were made of such variables as pH, rate of inactivation, and ratios of reactant concentrations, using oleic acid as a prototype of the effective acids. Attempts to recover active virus from inactive mixtures by decrease in pH, dialysis, dilution, or addition of calcium chloride solution to inactivated virus have been unsuccessful. The stability of virus at different hydrogen ion concentrations has been determined. Quantitative comparisons have been made of the immunizing capacity of fully active virus and virus rendered non infectious by treatment with oleic acid. It was found that while the infectious property of the virus is removed the immunogenic capacity is essentially unaltered. The possible mechanism by which the soaps act upon influenza virus has been discussed. PMID- 19870991 TI - AVIAN THIAMIN DEFICIENCY : A CORRELATION OF THE PATHOLOGY AND CLINICAL BEHAVIOR. AB - A correlation of the histopathology and clinical behavior of thiamin deficient pigeons has been undertaken. Opisthotonus in acutely deficient pigeons was frequently attended by no degenerating nerve fibers or neurons in either the central or peripheral nervous systems. When the deficiency was complicated by starvation, it developed more slowly, opisthotonus appeared later, and many degenerating nerve fibers were usually present. In both instances the opisthotonus disappeared in a very short time after thiamin was injected intramuscularly. A more chronic deficiency, characterized by leg weakness (opisthotonus being absent) appeared when the ration was partially deficient in thiamin, or occasionally when the caloric intake was grossly inadequate. In birds of this type degenerating nerve fibers were always found in the peripheral nerves. The number of such fibers in the sciatic nerves corresponded closely with the degree of paralysis, and during repair which occurred when thiamin (irrespective of other factors) was added to the ration, nerve fibers regenerated (increased in number) at a rate which paralleled the clinical improvement closely. The large and long nerve fibers, many of which could be traced directly into the dorsal ganglia, degenerated first, and if the deficiency were prolonged, smaller nerve fibers became affected as well. In many of these pigeons with marked leg weakness, cell bodies in the dorsal ganglia exhibited lysis of chromatin and eccentricity of their nuclei. This was observed nowhere else in the nervous system. During repair and until after the paralysis had been recovered from completely, these phenomena (chromatolysis) persisted. In chronically thiamin deficient pigeons large and long degenerating nerve fibers were found in two regions of the spinal cord at all levels. One group of these in the ventral funiculus was thought to arise in the reticular region of the medulla oblongata, and the other which was situated in the posterior part of the lateral funiculus could be followed to the lateral surface of the medulla oblongata, and from there by way of the inferior cerebellar peduncles into the medullary portion of the cerebellum. In the central as well as the peripheral nervous system the long and large nerve fibers degenerated first. Medium and small sized fibers were affected later and the degeneration became quite generalized. In many of the chronically deficient pigeons with leg weakness, incidental postmortem findings compatible with cardiac failure were encountered. In the hearts from many of these pigeons, microscopic examination revealed many areas of focal necrosis, some of which had become infiltrated with polymorphonuclear leucocytes. In a peripheral neuron of a thiamin deficient pigeon the first consistent morphological alteration appeared in the axis cylinder. No doubt a period of functional impairment of the neuron (such as produced opisthotonus) preceded this. The axis cylinder followed by the myelin sheath degenerated at a point most distal to its trophic cell body. This process of disintegration proceeded toward the trophic cell body for a variable distance, depending upon the severity and duration of the deficiency. The cell body (in a dorsal ganglion) appeared to shrink first and later exhibited chromatolysis. When thiamin was administered the axis cylinder (and myelin sheath) regenerated, and when this was complete, the cell body returned to normal. It has been concluded that the opisthotonus of thiamin deficiency is a manifestation of decerebration due to a functional impairment of the neurons which have an inhibitory influence upon the lower brain stem centers. Leg weakness (when produced by the same deficiency) is due to degeneration of peripheral nerve fibers within the sciatic nerve. Heart failure may be attended by no visible histological changes, but in many instances necrosis of myocardial fibers occurs. PMID- 19870992 TI - ULTRACENTRIFUGATION STUDIES OF YELLOW FEVER VIRUS. AB - 1. It was possible to study in the ultracentrifuge by optical methods the behavior of yellow fever virus particles directly in the unaltered serum from infected monkeys. 2. The virus showed an extremely high light absorption in the spectral range of 320 to 440 mmicro, which seemed to be its intrinsic property. In a 1 cm. thickness of fluid, the small amount of virus present in unaltered infective serum absorbed about as much light (approximately 25 per cent) in the middle of this range as did all the normal serum proteins present in a combined concentration some 1000 times as great. 3. The concentration of virus in the unaltered serum was found to be of the order of 0.00005 gm. per cc. 1 cc. of a 10(-9) dilution, which, as has been shown, may constitute a minimal infective dose for monkeys, would contain approximately 10,000 virus particles. The probability that most of the virus particles were in the inactive form is discussed. 4. In infective serum having a viscosity of 14 millipoises, the particles sediment with a blurred boundary at rates lying between approximately 18 and 30 x 10(-13) cm./sec./dyne. Evidence indicates that this spread is the result of an aggregation or association phenomenon. 5. Computations of size are in approximate agreement with those made from ultrafiltration studies. On the assumption that the density of the virus particle is near that of protein, its volume is computed to be at least that of a spherical particle having a diameter of 12 mmicro. An assumed density of 1.15 gm. per cc. yields a diameter of 19 mmicro, considering the shape as spherical. PMID- 19870993 TI - A DOG TEST FOR MEASURING THE IMMUNIZING POTENCY OF ANTIRABIES VACCINES. AB - 1. A quantitative method is described for testing the immunizing potency of antirabies vaccines in dogs. 2. Phenolized, single-injection, canine vaccines from seven manufacturers, when administered to dogs according to directions, failed to protect them against the least measurable amount of test virus fatal to 50 per cent or more of controls. Chloroformized vaccines from two of three manufacturers, under the same conditions, gave equivocal or suggestive results. 3. Commercial chloroformized vaccines in 10 cc. doses, injected intraperitoneally rather than subcutaneously into dogs, conferred a significant degree of immunity but proved temporarily irritative to the peritoneum. 4. These results of canine vaccines in dogs parallel closely those already reported in mice. PMID- 19870994 TI - THE UTILIZATION OF IRON AND THE RAPIDITY OF HEMOGLOBIN FORMATION IN ANEMIA DUE TO BLOOD LOSS. AB - The formation of hemoglobin in the anemic dog takes place at a very rapid rate. Radio-iron is detectable in the circulating red cells 4 hours after feeding. The absorbed labelled iron is entirely converted into hemoglobin within 4 to 7 days under standard anemic conditions. When red cell production has been accelerated by iron feeding or diet factors or when the dose of iron is very small, the dog can turn out as hemoglobin almost all the absorbed radio-iron in 2 to 3 days. In general, absorption of radio-iron as shown by utilization to form hemoglobin in anemic dogs is more efficient in small doses in single feeding experiments. As the iron intake is increased the percentage absorption rapidly falls. PMID- 19870995 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : I. CERTAIN BASIC ANALYSES AND OBSERVATIONS ON LIPID COMPONENTS OF THE VIRUS. AB - The results of chemical analyses reveal that it is possible to secure preparations of elementary bodies of vaccinia that possess a considerable uniformity in their chemical constituents. Furthermore, the amounts of certain of these constituents, namely, nitrogen, alpha-amino nitrogen after hydrolysis, phosphorus, total fat, phospholipid, neutral fat, reducing sugar after hydrolysis, and cystine, in the purified virus are significantly different from those in the various materials discarded during the process of purification. The amounts of phospholipid and neutral fat in the virus preparations are not appreciably affected by extraction with ethyl ether or by digestion with lipase, procedures which do not inactivate the virus. Cholesterol, on the contrary, is apparently completely removed by these manipulations, and hence is not considered to play an important part in the economy of the virus. PMID- 19870996 TI - I. POLIOMYELITIC VIRUS IN HUMAN STOOLS. AB - 1. The detection of the virus of poliomyelitis in 10 stools from 8 individuals is reported. All were in relation to epidemic poliomyelitis and 7 of them represented well recognized forms of the disease. The positive stools were distributed among 56 specimens collected from 53 persons in the first 4 weeks of illness. 2. The ease of detection of virus was directly related to the non paralytic type of disease and inversely related to the age of the patients. 3. The negative results with stools employed for controls gives point to the use of the fecal examinations as an epidemiological tool. 4. The stability of the virus in feces has been demonstrated by successful mailing of samples over long distances and during the heat of summer. 5. At least one infective dose per gram of fecal material was extracted from one stool. PMID- 19870997 TI - II. POLIOMYELITIC VIRUS IN URBAN SEWAGE. AB - In two out of three large urban epidemics of poliomyelitis the virus of this disease has been detected in samples of sewage. From one of the sites it was found repeatedly. Both positive sites were located in the vicinity of isolation hospitals, and we believe that the findings indicate that this virus can be transported, for short distances at least, through the medium of flowing sewage. PMID- 19870998 TI - III. METHOD FOR DETECTING POLIOMYELITIC VIRUS IN SEWAGE AND STOOLS. AB - 1. The active agent in sewage and aqueous suspensions of human stools, capable of producing poliomyelitis in rhesus monkeys after intraperitoneal inoculation, can be precipitated by 50 per cent saturation with ammonium sulfate, and no loss of activity seems to occur during this procedure. 2. The precipitated virus is not consistently "redissolvable" in water. 3. By precipitation and subsequent dialysis of the precipitate, a preparation is obtained which may be smaller in volume, and is less toxic for monkeys, than was the original material. 4. The procedure can be applied in tests on the infectivity of stools, and sewage specimens. PMID- 19870999 TI - THE ACTIVATING, TRANSFORMING, AND CARCINOGENIC EFFECTS OF THE RABBIT PAPILLOMA VIRUS (SHOPE) UPON IMPLANTED TAR TUMORS. AB - The effects of the rabbit papilloma virus upon tar tumor tissue are widely various, as the present paper and previous ones attest. It enables some of the benign tar tumors of domestic rabbits (papillomas, carcinomatoids) to establish themselves after implantation,-which they are unable to do under ordinary circumstances, being dependent upon favoring factors; and it may drive them to active proliferation without altering their morphology. Some growths it fails to influence and some it converts into virus papillomas. Often, however, it brings about cytological changes which are indicative of a combination of its influence with that of the undetermined factor motivating the original tumor. The resulting neoplasm exhibits a blend of characteristics. The virus makes some benign tar tumors become cancerous forthwith, the malignancy developing without intermediate virus papillomatosis. It can be readily imposed upon some of the squamous cell carcinomas which tar elicits in its natural host, the cottontail rabbit, and it may drive such tumors to proliferate faster, or alter them morphologically, or do both. Its stimulating effect is especially pronounced in the case of those tar cancers that are slow-growing. Since the virus can influence tar cancers markedly, one can scarcely suppose it to be devoid of effect upon the cancers of the same type which derive from the papillomas it has itself engendered. Other implications of the work are discussed. PMID- 19871000 TI - A TRANSPLANTABLE RABBIT CARCINOMA ORIGINATING IN A VIRUS-INDUCED PAPILLOMA AND CONTAINING THE VIRUS IN MASKED OR ALTERED FORM. AB - A squamous cell carcinoma derived from a virus-induced rabbit papilloma has been propagated in fourteen successive groups of animals. It grows rapidly now in most individuals to which it is transplanted, killing early and metastasizing frequently. The original cancer was the outcome of alterations in epidermal cells already rendered neoplastic by the virus, and the latter, or an agent nearly related to it, has persisted and increased in the malignant tissue, as a study of the blood of the first ten groups of cancerous animals has shown. An antibody capable of specifically neutralizing the virus in vitro appeared in the blood of every new host in which the tumor enlarged progressively, and reached a titer comparable with that obtaining in animals which had long carried large papillomas. The antibody was absent from normal rabbits and those in which the cancer failed to grow. The implications of these facts are considered. PMID- 19871001 TI - A DWARF MUTATION IN THE RABBIT : THE CONSTITUTIONAL INFLUENCE ON HOMOZYGOUS AND HETEROZYGOUS INDIVIDUALS. AB - An hereditary type of dwarfism in the rabbit has been described. In contrast to the dwarfs described in other animals, this type is evident at birth and conforms to the classification, nannosomia primordialis, as used in human pathology. In homozygous form the variation is lethal and produces a miniature individual approximately one-third the size of its normal sibs. Heterozygous animals are approximately two-thirds the size of normal sibs at birth and never attain an equal stature. The expression of the variation is modified by genetic factors carried by a line of cretinoid animals and, rarely, dwarfs derived from crosses with this line survive for 1 to 2 months. The striking changes in such survivors are hypertrophy and hyperplasia of the acidophilic cells of the pituitary and atrophy of the gonads. Such changes are not present in ordinary dwarfs and it is concluded that the acidophilic hyperplasia represents the influence of the modifying factors of the cretinoid line and supplies the growth hormone responsible for survival. The gonadotropic hormone is not supplied by the secretory activity of these cells and as a result the gonads atrophy. The evidence at hand indicates that the primary effect of the dwarfing gene is an inhibition of the secretory functions of the pituitary. In homozygous individuals, the inhibition is complete and the variation is expressed as a lethal dwarf. In heterozygous animals, the function of the organ is altered, producing an undersized individual. The modifying factors of the cretinoid line act either to partially remove the inhibition or to alter the constitution of the animal so that life is possible for a short period without the full complement of pituitary hormones. PMID- 19871002 TI - THE ACTION OF RENIN ON RABBITS WITH RENAL HYPERTENSION. AB - Our results lead us to believe that renin in the form in which it is extracted from the kidney cannot be the agent causing chronic renal hypertension. The reasons against accepting renin as the pressor substance responsible for the hypertension of renal ischemia may be summed up as follows:- 1. The high blood pressure levels of renal ischemia cannot be approximated by any constant injection of renin that will maintain a sustained increase in normal animals. 2. The ratio of size of response to size of dose becomes progressively less as the amount of the dose is increased. If the hypertension of renal ischemia were due to a large elaboration of renin in the body, a small dose injected would be expected to have much less effect than in a normal individual. This is not the case; the response of the hypertensive animal to a given dose of renin is the same. Also animals with increased blood pressure due to a constant infusion of renin respond differently qualitatively and quantitatively to renin than do animals hypertensive from renal ischemia. 3. Since renin exhibits the phenomenon of tachyphylaxis one cannot explain the sustained hypertension of renal ischemia as due to a substance toward which the body becomes refractory as more and more of it is given. If tolerance results from the presence in the renin preparation of an antagonistic contaminant which persists longer in the body than the pressor agent, renal hypertension is definitely not caused by renin. This follows from our observations that rabbits hypertensive from renal ischemia, and in which tolerance is produced, maintain the blood pressure they had before injection of any renin. PMID- 19871003 TI - CHOLINE AS A MEMBER OF THE VITAMIN B(2) COMPLEX. AB - The experimental rations commonly used in studies on the vitamin B(2) complex are, as a rule, low in content of choline. Addition of vitamin B(6) has an aggravating influence on the specific effect of deficiency of choline, especially with regard to the development of cortical necrosis of the kidneys. The acute and subacute lesions associated with this specific type of renal injury are described. The renal lesions and fat infiltration of the liver, observed in rats kept on a vitamin B free diet, supplemented with thiamine, riboflavin and vitamin B(6), are indistinguishable from those attributed hitherto to cystine intoxication. Attention is drawn to the role of choline as a potential member of the vitamin B(2) complex and, in this connection, to the importance of the ratio cystine/methionine in the diet. PMID- 19871004 TI - ELECTROPHORESIS OF THE COMPLEMENT-FIXING ANTIGEN OF HUMAN INFLUENZA VIRUS. AB - 1. An electrophoretic study has been made of normal mouse serum, influenza mouse serum, and influenza mouse lung suspension. The mobilities of the protein fractions present have been determined at various pH's by the optical method. 2. The pH-mobility curve of the soluble (complement-fixing) antigen present in the lung suspension has been determined analytically by sampling and application of the complement fixation test. The results show that the complement-fixing antigen has a mobility definitely smaller than that of serum albumin and close to that of a globulin, with an isoelectric point close to pH 5. PMID- 19871005 TI - THE OCCURRENCE OF MALARIA ANTIBODIES IN HUMAN SERUM FOLLOWING INDUCED INFECTION WITH PLASMODIUM KNOWLESI. AB - Evidence has been presented which indicates that antibodies appear in the serum of individuals following an induced malaria infection with Plasmodium knowlesi. PMID- 19871006 TI - STUDIES ON ANTIBACTERIAL IMMUNITY INDUCED BY ARTIFICIAL ANTIGENS : II. IMMUNITY TO EXPERIMENTAL PNEUMOCOCCAL INFECTION WITH ANTIGENS CONTAINING SACCHARIDES OF SYNTHETIC ORIGIN. AB - 1. Azoproteins containing structurally isomeric aldobionic acids evoke in rabbits antibodies which are both serologically and immunologically specific. 2. Antigens containing the azobenzyl glycosides of the synthetic gentio-biuronic and glucuronic acids evoke in rabbits antibodies which confer passive immunity on mice against infection with multiple lethal doses of virulent Type II pneumococci. PMID- 19871007 TI - ENCEPHALOMYELITIS OF MICE : I. CHARACTERISTICS AND PATHOGENESIS OF THE VIRUS. AB - 1. The two strains of virus named GD VII and FA, respectively, accidentally discovered during experiments with yellow fever, have been shown to be immunologically related to each other, as well as to the virus of mouse encephalomyelitis. 2. Infection of the central nervous system can be produced with both strains by intracerebral, intranasal, or intraperitoneal inoculations. The cardinal symptom produced by the GD VII strain of virus by all three methods of inoculation is a flaccid paralysis of the limbs. The symptoms produced by the FA strain are referable to lesions of the brain when infection is produced by intracerebral and intranasal inoculation. Following intraperitoneal inoculation of the FA strain of virus, however, a flaccid paralysis is usually produced. 3. By the use of graded collodion membranes the particle size of the virus of mouse encephalomyelitis has been shown to be from 9 to 13 mmicro 4. The stability of the virus at different hydrogen ion concentrations has been tested. It has been found that there are two optima of stability, one at about pH 8.0 and the other at pH 3.3. 5. The virus is readily inactivated at 37 degrees C. by 1 per cent hydrogen peroxide. 6. Of organic solvents tested, ether had no action, whereas ethyl alcohol in 20 per cent concentration almost completely inactivated the virus after 45 minutes in the cold. 7. The virus can be precipitated by means of ammonium sulfate. 8. With increasing age mice acquire a relative resistance to the virus. 9. Immunity to a subsequent intracerebral inoculation can be produced by intraperitoneal, as well as intranasal, administrations of relatively large amounts of virus. 10. Mice infected by the intracerebral inoculation of a relatively avirulent virus acquire a high degree of immunity to a subsequent inoculation of a highly virulent strain. 11. The course of infection in mice following intracerebral, intranasal, and intraperitoneal inoculation of the FA strain of virus has been studied. PMID- 19871008 TI - ENCEPHALOMYELITIS OF MICE : II. A METHOD FOR THE MEASUREMENT OF VIRUS ACTIVITY. AB - In a study of mouse encephalomyelitis the following observations were made:- 1. A definite relationship exists between the amount of virus inoculated intracerebrally and the length of the incubation period. 2. The reciprocal of the incubation period was found to be approximately proportionate to the logarithm of the amount of virus inoculated. The relationship can, therefore, be given a simple mathematical form. 3. This fact provides a basis for a new method for measurement of the activity of mouse encephalomyelitis virus. PMID- 19871009 TI - ENCEPHALOMYELITIS OF MICE : III. EPIDEMIOLOGY. AB - 1. In the feces of approximately two-thirds of normal mice 6 weeks of age an agent in all respects similar to the virus of mouse encephalomyelitis can be recovered. 2. In isolated mice, fed on sterile food and water, excretion of virus has been shown to persist up to 53 days after isolation. 3. In normal mice known to be virus carriers virus has been demonstrated in the gastro-intestinal tract but not in the central nervous system, thoracic or abdominal viscera, or any organs of the head. 4. The source of the virus excreted in the feces has been shown to be located in all probability in the intestinal wall. 5. Evidence is presented that the virus can invade the animal organism, as virus has been demonstrated in the mesenteric lymph glands. PMID- 19871010 TI - THE RELATIONSHIP OF SULFAPYRIDINE, NICOTINIC ACID, AND COENZYMES TO THE GROWTH OF STAPHYLOCOCCUS AUREUS. AB - Our studies indicate that sulfapyridine modifies the normal metabolism of a bacterium. Coenzymes inhibit the effect of sulfapyridine on the growth of staphylococcus in Knight's medium. Nicotinic acid does not interfere with the action of sulfapyridine under the same conditions. The possible relation of sulfapyridine, nicotinic acid, and coenzymes in relation to bacterial growth is discussed. PMID- 19871011 TI - A TRANSMISSIBLE AGENT (THEILER'S VIRUS) IN THE INTESTINES OF NORMAL MICE. AB - Every experiment with the contents of one, or with those pooled from two to five of the normal stock of Rockefeller Institute strain of albino mice, 1 to 2 months of age, revealed the presence of a virus which, after intracerebral inoculation into normal mice, induced characteristic paralytic encephalomyelitis, indistinguishable from Theilerapos;s disease. No difference was seen in this effect of intestinal contents deriving from animals paralyzed during the course of spontaneous encephalomyelitis and from normal mice. The influence of age on carriage of virus, as well as on the persistence of the carrier state, is discussed. The present, as well as previous work has shown that the virus found in normal (or paralyzed) mice is similar to that of Theiler's disease in all of its properties thus far investigated; among the strains of the latter now at hand it can be classified with those having a low degree of invasiveness after peripheral inoculation. The virus has thus far been recovered from intestinal contents, intestinal walls, and mesenteric glands but not from the central nervous system of normal mice; from these sites, as well as from the central nervous system, in paralyzed mice. In order of concentration of virus, the contents have more, the walls less, and the glands least. PMID- 19871012 TI - INFECTIOUS MYXOMATOSIS OF RABBITS : II. DEMONSTRATION OF A SECOND SOLUBLE ANTIGEN ASSOCIATED WITH THE DISEASE. AB - A second soluble antigen, separable from the virus, occurs in extracts of infected skin and in the serum of rabbits acutely ill with infectious myxomatosis. Like the first antigen (A), the second (B) is heat labile and has certain characteristics of a globulin. The two antigens precipitate in different concentrations of ammonium sulfate and can be separated by this method. Neither of the antigens after being heated at 56 degrees C. precipitates in the presence of specific antibody but each is capable of inhibiting the activity of its antibody. PMID- 19871013 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : II. PROPERTIES OF NUCLEIC ACID OBTAINED FROM VACCINE VIRUS. AB - It has been possible by means of classical chemical methods to isolate and to characterize to some extent the nucleic acid of elementary bodies of vaccinia. Determination by means of diphenylamine reagent revealed that the major part of the nucleic acid was of the thymus type. This was further substantiated by its stability in the presence of ribonuclease, less than 10 per cent undergoing depolymerization during prolonged incubation at 37 degrees C. By the technique employed, at least 5.6 per cent of the virus was shown to be thymonucleic acid. This amount agreed favorably with the value calculated from the non-lipid organic phosphorus of elementary bodies on the assumption that the phosphorus bound in the organic form was derived principally from nucleic acid. PMID- 19871014 TI - THE RENAL CLEARANCE OF HEMOGLOBIN IN THE DOG. AB - Simultaneous hemoglobin and creatinine renal clearance studies have been presented which indicate that hemoglobin is eliminated by the kidney at a rate which is 3 per cent of the creatinine clearance, above a plasma hemoglobin concentration of approximately 250 mg. per 100 cc. In dogs whose average glomerular filtration rate is 66 cc. per minute, about 2 cc. of plasma are cleared of hemoglobin per minute. A definite renal threshold exists for hemoglobin at a plasma concentration of about 100 mg. per 100 cc., below which hemoglobinuria does not occur. The uniformity of the process indicates that hemoglobinuria is not the result of a transient glomerular injury induced by the hemoglobin. It is tentatively suggested that the experimental results obtained may be interpreted in terms of the following concept. The glomerulus permits the filtration of hemoglobin in amounts directly dependent upon plasma concentration. However, only 3 per cent of all the pores of the membrane are electrostatically large enough to permit the passage of an undissociated hemoglobin molecule. Of that hemoglobin which passes down the tubule, a relatively constant though small amount is recovered by the tubules by a process not unlike that of phagocytosis found elsewhere in the body. An average value for this "athrocytic" capacity in a medium-sized dog is 2 mg. of hemoglobin per minute. This pattern of renal hemoglobin excretion is in agreement with the principles of the modern theory of kidney function. PMID- 19871015 TI - PRIMARY PULMONARY COCCIDIOIDOMYCOSIS : EXPERIMENTAL INFECTION WITH COCCIDIOIDES IMMITIS. AB - 1. The literature concerning inhalation infection with Coccidioides immitis is briefly reviewed. 2. A laboratory technique for exposing animals to inhalation of the spores of Coccidioides immitis is described. 3. Primary pulmonary infection was produced in 42 per cent of 72 animals exposed by this method. 4. No marked weight loss was apparent in the animals infected. 5. Skin tests with coccidioidin were not entirely satisfactory in diagnosis. Positive skin tests with coccidioidin were obtained in many of the infected animals, but inconsistencies occurred. 6. The gross and microscopic lesions are briefly described and illustrated. PMID- 19871016 TI - IDENTITY OF "INHIBITOR" AND ANTIBODY IN EXTRACTS OF VIRUS-INDUCED RABBIT PAPILLOMAS. AB - The "inhibitor" demonstrable in extracts of the virus-induced rabbit papillomas is identical with the antiviral antibody found in the blood of hosts bearing the growths. The conditions in these latter are frequently favorable to its extravasation in considerable amount into them. Its significance and its influence upon the recovery of virus from the papillomas are discussed. PMID- 19871017 TI - THE LIBERATION OF RENIN BY PERFUSION OF KIDNEYS FOLLOWING REDUCTION OF PULSE PRESSURE. AB - 1. Isolated dogs' kidneys have been perfused with defibrinated blood under hemodynamic conditions similar to those in the body. Under these circumstances blood flow, urine secretion, and oxygen consumption are well maintained, but urea clearance is low. Renal venous blood collected initially and at the end of 3 or more hours of perfusion exhibited no difference in vasoconstriction properties when perfused along with renin or renin-activator through an isolated rabbit's ear. 2. Reduction of pulse pressure by constricting the renal artery may be performed without reducing mean pressure significantly. Impairment of urea clearance and rate of urine secretion follow, and oxygen consumption is slightly reduced. 3. After an hour or more of perfusion with reduced pulse pressure, gradual rise in mean renal arterial pressure distal to the clamp and reduction of blood flow occur. 4. Renal venous blood collected after about one hour of perfusion with reduced pulse pressure differs from that collected before reduction of pulse pressure in that it causes intense vasoconstriction when perfused with renin-activator through an isolated rabbit's ear. 5. Perfusion of a dog's hind leg under similar circumstances does not cause this change in the venous blood to occur. PMID- 19871018 TI - PROPAGATION OF VACCINIA VIRUS IN THE RABBIT FETUS. AB - 1. A method is described for propagation of bacteria-free vaccinia virus in the rabbit fetus. 2. For the production of severe generalized infection, affording a high yield of virus, the following conditions were found to be favorable: the use of 24 day fetuses, a virus dosage of 10,000 adult rabbit skin units, injection into multiple sites, and an incubation period of 4 days in utero. 3. Under these conditions the virus was found to disseminate widely in the infected fetus, being recoverable particularly from liver, lungs, brain, skin, placenta, and kidney. 4. Under varied conditions of virus dosage, fetal age, and incubation period, all grades of reaction were observed in the fetus, ranging from the mildest infection, with only an occasional small lesion demonstrable, to generalized vaccinia with pocks in nearly every organ of the body, and often death. 5. It was shown that the virus could be carried in serial passage through fetuses. A series of 27 such passages was made by using fetal skin for subinoculation at each transfer. Similarly, two other strains of the virus were evolved in shorter series of transfers by using respectively fetal brain and fetal liver as the subinocula. 6. The passage strains maintained their identity and titer, as judged by the intradermal inoculation of adult rabbits. However, these strains underwent a significant reduction in their capacity to infect by the scarification method, and the lesions induced by intradermal inoculation were much milder than those produced by the parent strain. None of the passage strains manifested properties characteristic of the so called neurovaccine strain, despite the frequent use of intracerebral inoculation in the fetuses. 7. In explanation of the reduction of virulence of the passage strains, it is suggested that a given suspension of virus may be considered as consisting of particles of varying degrees of virulence, and that when cultivation is carried out in highly susceptible tissues a relative overgrowth of the less virulent elements is permitted, so that apparent attenuation results. PMID- 19871019 TI - THE INHIBITION OF THE BACTERIOSTATIC ACTION OF SULFONAMIDE DRUGS BY SUBSTANCES OF ANIMAL AND BACTERIAL ORIGIN. AB - Sulfonamide inhibitor has been demonstrated in extracts of fresh normal muscle, pancreas, and spleen of certain animals. When autolysis of tissues takes place the amount of inhibitor is greatly increased. Fresh liver from beef, rabbit, and guinea pig is free of active inhibitor, although inhibitor is demonstrable in autolysates of this tissue. Fresh rabbit kidney is likewise free of active inhibitor. Following acid hydrolysis extracts of fresh rabbit liver and kidney cause sulfonamide inhibition. Normal human urine contains little or no active inhibitor. However, upon acid hydrolysis, inhibitor is uniformly present. Sulfonamide inhibitor is present in some, but not all, sterile serous effusions occurring during certain diseases. Inhibitor was found uniformly in pus. None was found in blood serum. In certain species of bacteria the inhibitor is found in the cells only and is not demonstrable in the culture medium, whereas in other species, the inhibitor is found in the culture supernatant, and the cells themselves are relatively free. The development of sulfapyridine fastness in a strain of Pneumococcus Type I is accompanied by a greatly increased production of sulfonamide inhibitor. PMID- 19871020 TI - STUDIES ON EPIDEMIC INFLUENZA VIRUS : THE NATURE AND PROPERTIES OF THE COMPLEMENT FIXING ANTIGEN. AB - Evidence is presented which indicates that influenza virus elaborates a soluble antigen. The antigen is considerably smaller than the virus and can be separated from it, but the virus has not been washed free of antigen. The properties of the antigen suggest that it is an unstable protein of relatively large size. PMID- 19871021 TI - THE SYNERGISM OF HUMAN INFLUENZA AND CANINE DISTEMPER VIRUSES IN FERRETS. AB - The infections produced in ferrets by human influenza virus and canine distemper virus were studied. Cross immunity and cross neutralization tests showed that these two viruses were not related antigenically. Ferrets infected with influenza virus alone rapidly produced considerable quantities of neutralizing antibodies, and after the 6th day virus was not demonstrable in their lungs. Ferrets infected with both influenza and distemper viruses simultaneously produced but small amounts of neutralizing antibody, and influenza virus persisted in undiminished concentration in their lungs throughout the course of the infection. PMID- 19871022 TI - STUDIES ON THE PATHOGENESIS OF EXPERIMENTAL PNEUMOCOCCUS PNEUMONIA IN THE DOG : I. SECONDARY PULMONARY LESIONS. RELATIONSHIP OF BRONCHIAL OBSTRUCTION AND DISTRIBUTION OF PNEUMOCOCCI TO THEIR INCEPTION. AB - A study has been made of the mode of origin of the secondary lesions occurring spontaneously during the course of experimental pneumococcus pneumonia in the dog. It was observed that the primary lesions of dogs exhibiting interlobar spread contained much more edema fluid than did those in which the inflammatory process remained confined to a single lobe. Furthermore, the sequence of spread from lobe to lobe in relation to the anatomical arrangement of the bronchi and the prone position of the animal was such as to suggest that secondary lobe involvement arose as a result of edematous pneumonic exudate flowing into the more dependent bronchial openings. Experiments were undertaken to determine whether pneumococci are constantly being distributed throughout the lung in the experimental disease in varying degree yet produce secondary foci of consolidation only if the microorganisms reach the terminal airways and are retained there through some interference with the normal eliminatory mechanism. Attempts to produce secondary lesions in dogs with non-spreading single lobe involvement, by means of plugging a terminal bronchus of a normal lobe with starch paste or mucin were largely unsuccessful. In only three out of 19 instances did a lesion develop at the site of obstruction. An investigation was then made of the distribution of pneumococci in the lungs of dogs at the height of the pneumonia. In dogs with single lobe lesions pneumococci were recovered from the lesion itself but not from any other part of the peripheral lung tissue, whereas in animals showing spread to other lobes pneumococci were found to be distributed widely throughout the lung in both the apparently normal and the involved lobes. Some of the microscopic sections of the uninvolved parts of the lungs of dogs with metastatic lesions revealed small masses of pneumococcus containing exudate in the smaller bronchi and terminal airways of otherwise normal tissue. This finding, in conjunction with the detection of beginning inflammatory changes in other areas normal in the gross, would seem to provide direct evidence of the manner in which pneumococci are transferred from the initial lesion to other lobes and highly presumptive evidence for the mode of origin of the secondary lesions. PMID- 19871023 TI - STUDIES ON THE PATHOGENESIS OF EXPERIMENTAL PNEUMOCOCCUS PNEUMONIA IN THE DOG : II. SECONDARY PULMONARY LESIONS. THEIR PRODUCTION BY INTRATRACHEAL AND INTRABRONCHIAL INJECTION OF FLUID PNEUMONIC EXUDATE. AB - On the basis of earlier findings, which suggested that interlobar spread in experimental canine pneumonia was due to the flow of infected edematous exudate from the initially involved lobe to other parts of the lung by way of the air passages, an attempt was made to induce secondary lesions by means of the intrabronchial and intratracheal injection of fluid pneumonic exudate. Such exudate was aspirated from the lungs of dogs with rapidly evolving lesions and injected through a bronchoscope into other animals showing well localized monolobar involvement which is seldom associated with spread to other parts of the lung. The deposition of relatively small amounts of fluid exudate in the larger air passages 24 to 48 hours after the onset of the disease was followed regularly by the occurrence of secondary lesions provided the dog was maintained in a position favoring the flow of fluid into the depths of the lung. Lesions in the various lobes could be produced at will by arranging the position of the animals so that the injected fluid would be carried by gravity into the most dependent bronchial opening nearest the point at which the exudate was deposited. Pneumonia was produced by this means as readily in normal dogs as in those with infection already present. If, however, the dog was placed in a position unfavorable to the flow of fluid into the bronchi, infection did not occur. Likewise the injection of viscid pneumonic exudate, with the animal tilted at an angle most favorable for entrance into the lobe bronchi, did not result in pulmonary involvement. These artificially induced secondary lesions resembled in every way both macroscopically and microscopically those occurring spontaneously in the course of the experimental disease. PMID- 19871024 TI - STUDIES ON THE RENAL ARTERIAL BLOOD PRESSURE AND THE METABOLISM OF KIDNEY TISSUE IN EXPERIMENTAL HYPERTENSION. AB - 1. In the hypertension which accompanies constriction of the renal arteries, there is no constant relationship between the height of the general systemic arterial pressure and the pressure in the renal artery distal to the point of constriction. The hypertension may persist even though the renal arterial pressure returns to or almost to the control level. 2. Studies on the renal blood flow and oxygen consumption following subtotal nephrectomy were abandoned because of inability to produce hypertension in dogs by this method. It is suggested that the mechanism of the hypertension following renal arterial constriction (dogs) and that following subtotal nephrectomy (rats) may not be the same in the two instances. 3. Studies on isolated renal cortical tissue of dogs and of rabbits following renal arterial constriction and subtotal nephrectomy showed that there is not necessarily a diminution in the capacity of the tissues of hypertensive animals to use oxygen. PMID- 19871025 TI - THE VASOCONSTRICTOR ACTION OF PLASMA FROM HYPERTENSIVE PATIENTS AND DOGS. AB - 1. Plasma from the renal vein, femoral artery or vein of normal dogs and plasma from the femoral artery, femoral and antecubital veins of man cause little or no vasoconstriction when added in small amounts to blood from a bilaterally nephrectomized dog used as perfusing medium in an isolated rabbit's ear. 2. Plasma from the femoral vessels and antecubital vein of patients with essential hypertension, malignant hypertension, and chronic nephritic hypertension causes marked vasoconstriction under the same circumstances. The plasma of dogs made hypertensive either by constriction of the parenchyma by the scar of silk perinephritis or by constriction of the renal artery by a clamp also causes pronounced vasoconstriction. 3. Plasma from the renal vein of normal dogs produces little or no vasoconstriction, but that of hypertensive dogs elicits vasoconstriction but usually not so marked as that elicited by plasma collected from peripheral vessels. A sample of renal venous plasma from one hypertensive patient caused severe vasoconstriction, not quite so intense as that produced by the peripheral vein plasma. 4. Since renin is liberated into the renal vein in large amounts in hypertensive dogs and reacts with renin-activator to produce angiotonin and since the conditions of the experiment are such as to enhance greatly the sensitivity of the ear preparation to angiotonin, it is believed that the vasoconstriction is the result of the presence of angiotonin in the peripheral blood. 5. Since vasoconstriction occurs under the same experimental conditions with plasma from both hypertensive patients and dogs, this is considered cogent evidence in favor of the view that the chemical mediator of both is similar and is possibly angiotonin. 6. A method is presented which is believed will distinguish between plasma from patients with normal blood pressure and that from those with hypertension, and between plasma from normal dogs and that from dogs with experimental renal hypertension. PMID- 19871026 TI - HETEROTRANSPLANTATION OF FROG CARCINOMA; CHARACTER OF GROWTH IN THE EYES OF ALIEN SPECIES. AB - Transplantation into foreign hosts of the kidney carcinoma of leopard frogs has been investigated by grafting the tumor in the anterior chamber of two other species belonging to the same family of frogs (green frog, bullfrog), of a species from a different family (the toad), and of animals of different classes of cold-blooded vertebrates (goldfish, alligator). In the eyes of frogs of alien species, the kidney carcinoma became established as readily as in the eye of the natural host. In toads, the proportion of successful transplantation was slightly less. No progressive growth of transplanted tumor occurred in the fish or the reptile, although in fish characteristic tumor acini persisted and a few mitoses were to be found long after implantation. In the alligator the transplants deteriorated much more rapidly. Thus the success of transplantation into alien species decreased as the relationship to the original species became more distant. An inflammatory reaction to the tumor graft appeared in the eye of reptiles and fish, but no such reaction occurred in amphibians. The character and rate of growth of transplants were followed by continued direct examination with the microscope and were found to be practically the same in the eye of alien species as in the original species. Nor were differences in the finer structure of the tumor observed in the several species. The neoplastic cells retained their acinar arrangement, supported by stroma which developed quite as well from the tissues of alien hosts as from those of the natural host. It was possible to engraft the tumor in the eye of the natural host, then to transplant it into the eye of another species, and finally to retransplant it in the original species. In this way the tumor has been propagated for 443 days. A tissue culture of the tumor has been successfully transplanted into the eye of an alien host. Thus these results demonstrate that, among cold-blooded vertebrates, the humors and tissues of the eye have a high degree of tolerance for foreign tumor grafts. PMID- 19871027 TI - THE EFFECT OF TEMPERATURE ON THE GROWTH OF FROG CARCINOMA : I. DIRECT MICROSCOPIC OBSERVATIONS ON LIVING INTRAOCULAR TRANSPLANTS. AB - From the results of these experiments we can now attempt to answer the questions proposed in the introduction. Just as in normal tissues, it has been found that growth and development of a malignant neoplasm are influenced by temperature both quantitatively and qualitatively. The most striking effect was the acceleration in the rate of growth of the tumor at higher temperature, and retardation at lower. The ultimate size attained within periods averaging 3 months was regularly much greater at higher temperature. Also, the character of growth was quite different. At high temperature, there was more efficient vascularization, and the tumors formed long, branching, tubular outgrowths and cysts; at low temperature the outgrowths were short and stubby and cysts were rare. These differences were accentuated by repeatedly passing the tumor from one generation to another. In particular, in such serial passages, there was a remarkable tendency for the tumor to develop greatly dilated tubules and large cysts, which later, however, became solid as the result of ingrowth from the wall. The experiments demonstrate that the carcinoma in the frog can exist over a wide range of temperature. Even a temperature as low as 4 degrees , as in the hibernation experiment, produces no injury to the tumor. This result is consistent with the common occurrence of large, healthy, spontaneous tumors in frogs which have recently hibernated in their natural state. PMID- 19871028 TI - INFECTION OF GUINEA PIGS BY APPLICATION OF VIRUS OF LYMPHOCYTIC CHORIOMENINGITIS TO THEIR NORMAL SKINS. AB - As shown in Table I, 97 guinea pigs were used in this study. Fifty-seven were exposed by placing a virus suspension on their normal skins. Of this number, 34 had screw-top capsules attached to them. Thirteen were exposed by spreading the virus suspension on their feed and cage litter. Ten were inoculated intracerebrally to establish the potency of the virus. The remaining 17 were not exposed artificially to the virus and were employed as controls to detect cross infection. Twenty-two guinea pigs, to which capsules were attached, died as a result of virus infection; 1 died of unknown causes and 11 survived without showing any clinical signs of the infection. Sixteen of the animals without the capsules died of virus infection and 7 did not become infected. The 10 guinea pigs that were inoculated intracerebrally became infected and died. None of the animals that were exposed by spreading the virus on the feed and the litter in the cages, or those used as unexposed controls, developed any clinical signs of infection with lymphocytic choriomeningitis. It is realized that minute abrasions, not visible with a hand lens, may have been present in the skins of these guinea pigs. However, any condition of this nature would be a factor encountered in any normal skin. In view of these facts, it is believed that these results indicate that the virus of lymphocytic choriomeningitis may infect guinea pigs through the normal, apparently intact, skin. PMID- 19871029 TI - THE DEPRESSOR EFFECT OF SPLENO-RENO-PEXY ON HYPERTENSION DUE TO RENAL ISCHEMIA. PMID- 19871030 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : VIII. SENSITIZATION TO PICRIC ACID; SUBSIDIARY AGENTS AND MODE OF SENSITIZATION. AB - Sensitization of guinea pigs to picric acid was obtained by application of oil solutions to the skin, preferably on inflamed sites or by treatment with a compound of picric acid with n-butyl-p-aminobenzoate. The lesions obtained in sensitive animals on superficial administration bore resemblance to human eczema. It seems probable that picric acid sensitization is an instance where a substance does not sensitize directly but after conversion into a more reactive compound, a principle which should be of wider application to instances where the original substance does not readily form conjugates. PMID- 19871031 TI - THE PROLONGED COEXISTENCE OF VACCINIA VIRUS IN HIGH TITRE AND LIVING CELLS IN ROLLER TUBE CULTURES OF CHICK EMBRYONIC TISSUES. AB - 1. The virus of vaccinia in so called roller tube cultures of mixed embryonic chick tissue rapidly increases to maximal titre. 2. Under these conditions the quantity of virus in the tissue remains at or near the maximum for at least 9 weeks and considerable amounts are present in the fluids removed each day. 3. The same results are obtained when only fragments of embryonic chick heart are employed. 4. Many, though not necessarily all, of the cells in infected cultures remain alive and retain the capacity to proliferate. The presence of these living cells is essential for the persistence of the virus. 5. No apparent differences in the rate or amount of growth of cells in infected as contrasted with non infected cultures can be discerned in the gross. 6. It is suggested, but not proved, that virus is continually being produced rather than simply preserved throughout the period. PMID- 19871032 TI - A SOLUBLE ANTIGEN OF LYMPHOCYTIC CHORIOMENINGITIS : II. INDEPENDENCE OF ANTI SOLUBLE SUBSTANCE ANTIBODIES AND NEUTRALIZING ANTIBODIES, AND THE ROLE OF SOLUBLE ANTIGEN AND INACTIVE VIRUS IN IMMUNITY TO INFECTION. AB - Anti-soluble substance antibodies and neutralizing substances, which develop following infection with the virus of lymphocytic choriomeningitis, appear to be separate entities. The times of appearance and regression of the two antibodies are different in both man and the guinea pig; the antisoluble substance antibodies appear earlier and remain a shorter time. Moreover, mice develop them but no demonstrable neutralizing substances. Injection of formalin-treated, virus free extracts containing considerable amounts of soluble antigen fails to elicit anti-soluble substance antibodies and to induce immunity in normal guinea pigs; administration of such preparations to immune pigs, however, is followed by a marked increase in the titer of anti-soluble substance antibodies in their serum. On the other hand, suspensions of formolized washed virus are effective in normal guinea pigs in stimulating both anti-soluble substance antibodies and protective substances, and in inducing immunity to infection. PMID- 19871033 TI - STUDIES OF A MURINE STRAIN OF POLIOMYELITIS VIRUS IN COTTON RATS AND WHITE MICE. AB - 1. A neurotropic murine virus was isolated by passing poliomyelitis virus (SK strain) from the monkey to cotton rats and white mice. 2. The murine virus has been grown in tissue culture consisting of embryonic mouse brain in ox serum ultrafiltrate. 3. The symptoms and lesions produced by the murine infection compare in all respects with those of poliomyelitis in monkey and man. 4. The murine virus, while highly pathogenic for mice and cotton rats, is non-pathogenic for albino rats, guinea pigs, and rabbits. It possesses limited pathogenicity for rhesus monkeys. 5. Although producing no paralysis in the above mentioned refractory animals, the murine virus may be recovered in active form from neural and extraneural sites of infected albino rats, guinea pigs, and monkeys, but not from rabbits. 6. The identity of the murine and monkey virus is further suggested by cross-neutralization between the murine virus and homologous (SK) and related (Aycock) antipoliomyelitis sera, as well as between homologous and related monkey poliomyelitis virus and antimurine virus sera. 7. Immunization of monkeys with live murine virus, in the form of mouse brain or tissue culture, seems to confer some degree of resistance against subsequent infection with the homologous poliomyelitis monkey virus. 8. The presence of the murine virus in the central nervous system of infected monkeys appears to interfere with the propagation of SK and Aycock poliomyelitis monkey virus in the same animal. PMID- 19871034 TI - THE USE OF ULTRAVIOLET LIGHT IN PREPARING A NON-VIRULENT ANTIRABIES VACCINE. AB - Rabies virus, exposed to the rays of a mercury vapor lamp under proper conditions, loses virulence yet retains considerable immunizing potency for mice. PMID- 19871035 TI - INFLUENCE OF AGE FACTORS ON SUSCEPTIBILITY OF MICE TO RABIES VIRUS. AB - 1. 7 to 9 day old mice are more susceptible than older mice to injections of fixed or street virus by any route. 2. 20 day old mice are more susceptible than 60 day old mice to peripheral but not intracerebral injection of fixed virus. 3. 20 day and 60 day old mice are equally susceptible to street virus. PMID- 19871036 TI - INFLUENCE OF AGE FACTORS ON IMMUNIZABILITY OF MICE TO RABIES VIRUS. AB - 1. W-Swiss mice 60 or more days old are more readily immunizable against rabies virus infection than 20 day old or younger mice; this difference in immunizability with increasing age is most conspicuous when vaccination with virulent virus is followed by intracerebral test infection and least apparent when vaccination with avirulent virus is followed by intramuscular test infection. 2. The titre of circulating neutralizing antibodies does not parallel the titre of immunity. PMID- 19871037 TI - NUTRITIONAL CYTOPENIA IN MONKEYS RECEIVING THE GOLDBERGER DIET. AB - Experiments are reported upon young rhesus monkeys which were given a diet essentially the same as the Goldberger black tongue-producing diet, supplemented in various ways. Those receiving the unsupplemented diet developed the syndrome characterized by leucopenia, anemia, gingivitis, diarrhea, and death, which has been previously described in monkeys receiving our diet of refined foodstuffs. An animal receiving the Goldberger diet supplemented with ascorbic acid and liver extract exhibited normal growth and development and has maintained a normal blood picture for approximately 2 years. Likewise, the feeding of a crude liver extract to an animal with profound anemia and leucopenia was followed by a dramatic reticulocyte response and ultimate recovery. However, the ash of liver extract failed to maintain a normal blood picture or to prolong life. Supplementing the diet with ascorbic acid, thiamin chloride, nicotinic acid (or amide), and riboflavin failed to prevent the leucopenia, gingivitis, diarrhea, and death. The combination of nicotinic acid and riboflavin, however, appeared to have a definite erythropoietic effect. Shigella paradysenteriae was isolated from the stools of several of the animals which received the deficient diet. Further studies are needed to clarify the relationship between the deficiency, the infection, and the blood picture. Three of the animals exhibited edema of the face. It is evident that the Goldberger diet, even when supplemented with nicotinic acid, riboflavin, thiamin, and ascorbic acid, is inadequate for maintenance of health in the young monkey. The nature of the deficiency manifestations would indicate that the diet is deficient in the substance or substances which we have previously termed vitamin M. PMID- 19871038 TI - HEMOGLOBIN AND PLASMA PROTEIN : SIMULTANEOUS PRODUCTION DURING CONTINUED BLEEDING AS INFLUENCED BY DIET PROTEIN AND OTHER FACTORS. AB - Given healthy dogs, fed abundant iron and a limited protein diet, with sustained anemia due to simple bleeding, we can study the capacity of each animal to produce new hemoglobin and plasma protein. Some dogs can produce much hemoglobin and enough new plasma protein to maintain the plasma protein concentration at approximately a low normal level. It is probable that their plasma protein producing capacity is not fully extended (Table 2). Other dogs (Table 5) can produce the same amount of hemoglobin but a hypoproteinemia develops and continues which should mean a maximal stimulus to produce new plasma protein. In such dogs we have strong stimuli to produce simultaneously new hemoglobin and new plasma protein. The ratio of plasma protein to hemoglobin varies from 40 to 60 per cent. The total new formed blood protein may amount to 30 to 40 per cent of the total diet protein intake which shows that some dogs have remarkable capacity to conserve and use diet protein. In this emergency of simultaneous depletion of hemoglobin and plasma protein levels, the dog gives preference to hemoglobin manufacture no matter what one of the listed food proteins is tested. PMID- 19871039 TI - THE TISSUE SPECIFICITY OF BRAIN AND MEDULLATED NERVES AS SHOWN BY PASSIVE ANAPHYLAXIS IN GUINEA PIGS. AB - Prolonged immunization of rabbits with a sedimented, heat-killed vaccine of Pasteurella boviseptica grown in an infusion broth prepared from rat brain resulted in the production of antisera containing antibodies for the broth as well as for the bacteria. When guinea pigs were prepared by intra-abdominal injection with such antisera and tested 24 hours later by intravenous injection with autoclaved extracts of different organs and tumors of rats, they were found to be passively sensitized, so that severe or fatal anaphylaxis was obtained with extracts of brain and carcinoma 256,-a transplantable tumor of the rat which originated in the mammary gland,-and very slight or negative reactions with extracts of other tissues. The brain antigen was found to be organ-specific but not species-specific. It was present in the white matter of the central nervous system and in sciatic nerve, but was almost completely absent from the brains of fetal and newly born rats and rabbits. It was absent from the brain of the fetal guinea pig but was present very soon after birth. The amount of the specific brain antigen seemed to be dependent upon the length of the period of gestation, the stage of development of the animal at birth, and the degree of myelinization of the central nervous system. The anaphylactogen of brain broth was soluble in water and insoluble in strong ethyl alcohol. It was thermostable in neutral and slightly acid solutions but more or less thermolabile on the alkaline side of neutrality. PMID- 19871040 TI - ELECTROPHORETIC STUDIES ON ELEMENTARY BODIES OF VACCINIA. AB - Electrophoretic studies were made on vaccine virus, collodion particles, and glass particles suspended in 0.01 molar buffer solutions at pH 7.9, in which the moving boundary method was used. In some experiments, uncoated particles were used; in others, particles were coated with proteins and then resuspended in the buffer solution after a washing; in still others, an excess of protein which had been used to coat the particles was included in the buffer medium. Streaming boundaries were obtained with all dilute suspensions of particles in solutions containing no soluble protein instead of the flat ones usually observed with the Tiselius moving boundary technique. This boundary artifact was suppressed by maintaining a density gradient of sufficient magnitude in association with the moving boundary to counteract the tendency of endosmotic flow. This was done partially by increasing the concentration of the particles in the suspensions, and almost completely by retaining an excess of soluble-coating substance in the solutions containing the particles. The mobility of elementary bodies of vaccinia corresponds to that found for the heat-stable (S) antigen. This value was not altered by drying, heating, ether extraction, or simple washing, but was materially increased by treatment with the surface active detergent (duponol) which presumably altered the nature of the surface of the virus particles. Collodion particles coated with the heat-stable antigen of vaccinia had the same mobility as elementary bodies under comparable conditions. Glass particles coated with normal rabbit serum moved at the rate of albumin, the fastest serum component in the buffer solutions used. However, both collodion particles and vaccine virus moved at a somewhat slower rate when they were similarly coated and measured in the presence of an excess of serum in the solutions. This was probably due to adsorption of a small amount of one of the slower components (globulin) of rabbit serum on the surface of the particles. Simple washing after treatment seemed to remove the coating of serum proteins, at least in part, from both collodion particles and elementary bodies of vaccinia. PMID- 19871041 TI - OBSERVATIONS ON MIXTURES OF ELEMENTARY BODIES OF VACCINIA AND COATED COLLODION PARTICLES BY MEANS OF ULTRACENTRIFUGATION AND ELECTROPHORESIS. AB - It has been shown experimentally that mixtures of two types of particles, namely, elementary bodies of vaccinia and collodion particles coated with protein, sediment with a single boundary in the analytical centrifuge. Such mixtures have been shown to develop one or two boundaries on electrophoresis in the Tiselius apparatus, depending on the type of coating on the surface of the collodion particles. When covered with the heat-stable soluble antigen of vaccinia, collodion particles migrate in the electrical field at the same rate as elementary bodies. On the other hand, if they are coated with a component of normal rabbit serum, they migrate at a different rate. The estimation of purity of preparations of virus by means of data obtained by ultracentrifugation and electrophoresis is discussed. PMID- 19871043 TI - THE MECHANISM BY WHICH EXPERIMENTAL NEPHRITIS IS PRODUCED IN RABBITS INJECTED WITH NEPHROTOXIC DUCK SERUM. AB - 1. Glomerulonephritis was produced in rabbits by the injection of antirabbit kidney duck serum. 2. The clinical and pathologic characteristics of the disease are discussed. 3. It was found possible by appropriate means either to accelerate the development of the nephritis or to prevent its appearance entirely. 4. An apparent correlation was found between the development of the nephritis and the formation of antibodies to duck serum by the injected rabbit. 5. The generally accepted concept of the mechanism of the disease does not appear to be in accordance with the facts here observed. A new hypothesis is presented. PMID- 19871042 TI - UNION IN VITRO OF THE PAPILLOMA VIRUS AND ITS ANTIBODY. AB - Experiments are described which show that the rabbit papilloma virus elicits an antibody of one type only, this being capable both of neutralizing the virus and of fixing complement in mixture with it. The virus and its antibody have a powerful, specific affinity for one another, each being capable of absorbing the other in great excess when they are brought together in the test tube. The union formed by them in vitro cannot be dissociated in any demonstrable degree by dilution or centrifugation. In many respects the findings differ from those with most viruses previously studied. PMID- 19871044 TI - EXPERIMENTAL ENCEPHALITIS : SOME FACTORS AFFECTING INFECTION WITH CERTAIN NEUROTROPIC VIRUSES. AB - The action on mice of several neurotropic viruses was studied with reference to factors which influence infection. With pseudorabies virus, section of the sciatic nerve with inoculation into the ipsilateral foot pad significantly retarded the speed of infection. The virus ascended other nerves of the leg, but at a slower rate. It would appear that the number of nerve fibers available for passage may play a role in the speed with which infection occurs with this virus. When pseudorabies virus was inoculated into an area of inflammation its effects were markedly lessened. Similar experiments with unmodified equine encephalomyelitis virus which, unlike pseudorabies, does not ascend along local nerves, showed no impedance of infection. Brain trauma did not change the rate of infection with the viruses of St. Louis encephalitis, herpes, or pseudorabies. But intraperitoneal injection of glycerine, followed by intramuscular inoculation of St. Louis virus, resulted in marked facilitation of infection, as already remarked of fixed equine encephalomyelitis virus. This phenomenon did not occur with pseudorabies or herpes. In contrast to certain other viruses, pseudorabies and herpes viruses were only slightly more effective in young mice than in adults. With St. Louis virus, as with fixed equine encephalomyelitis viruses, inoculation into the eye or nose was far more effective than other peripheral routes. This was not the case with pseudorabies. Herpes, however, also showed greater sensitivity of the intraocular route. After injection into the eye, St. Louis and fixed equine encephalomyelitis viruses invaded the optic pathway, while herpes and pseudorabies avoided the optic fibers and attacked the trigeminal nerve. These phenomena are discussed in the light of cellufugal and cellupetal progression of viruses. The similarities in the action of fixed equine encephalomyelitis and St. Louis encephalitis viruses are discussed and contrasted with herpes and pseudorabies. PMID- 19871045 TI - THE RECOVERY FROM PATIENTS WITH ACUTE PNEUMONITIS OF A VIRUS CAUSING PNEUMONIA IN THE MONGOOSE. AB - 1. A virus capable of producing pulmonary consolidation in the wild mongoose (Herpestes griseus) has been isolated from throat washings obtained from four patients with a clinical syndrome termed acute pneumonitis. 2. The virus was not pathogenic for ferrets, mice, guinea pigs, rabbits, monkeys, voles, hamsters, deer mice, skunks, opossums, or woodchucks. 3. The virus was filterable through Berkefeld V and N candles, was not inactivated by glycerin or by freezing and drying in vacuum, and was propagated for at least 30 serial passages on the chorio-allantoic membrane of the developing chick embryo. 4. Normal mongooses placed in contact with infected mongooses developed pulmonary consolidation. 5. The virus was neutralized by the serum of mongooses convalescent from the infection but was not neutralized by normal mongoose serum. 6. Serum of human beings convalescent from acute pneumonitis also neutralized the virus, but serum obtained from the same individuals during the acute phase of the disease failed to do so. 7. The evidence so far obtained strongly suggests that this virus is the cause of acute pneumonitis in human beings. It differs from other viruses known to cause infections of the respiratory tract in man. PMID- 19871046 TI - THE PLACENTAL TRANSMISSION OF ANTIBODIES IN THE SKIN SENSITIVE TYPE OF HUMAN ALLERGY. AB - 1. Quantitative studies of the skin-sensitizing antibodies, blocking antibodies, and hemagglutinins in sera of allergic human beings have been made. 2. A comparison of 12 maternal and the 12 corresponding cord sera by the method of passive transfer showed the human placenta to be impermeable to skin-sensitizing antibodies. 3. Direct skin tests and passive transfer studies of 6 infants at the ages of 3 to 6 months showed negative reactions to the antigens to which their mothers were sensitive. 4. The blocking antibody present in the sera of hay fever patients after treatment with pollen extract injections was also demonstrated in the cord sera. The apparent placental transmission of this antibody gave further evidence that it was distinct from the skin-sensitizing antibody. Infant sera obtained at the ages of 3 to 6 months showed no evidence of this immune antibody. 5. The cord sera from 4 of these cases were shown to contain the same isoagglutinins as the maternal sera, showing that the placentas were permeable to these antibodies. The mothers and their offspring reacted alike to Schick testing. 6. Typhoid agglutinins were demonstrated in maternal and cord sera of an adult who previously received injections of triple typhoid vaccine, whereas the serum of the corresponding infant at the age of 3 months failed to show agglutinins. PMID- 19871047 TI - THE COMPARATIVE SUSCEPTIBILITY OF FETAL AND POSTNATAL GUINEA PIGS TO THE VIRUS OF EPIDEMIC INFLUENZA. AB - Experiments were carried out to determine the relative susceptibility of guinea pigs at different ages to the virus of epidemic influenza. From a correlation of these studies on the mature fetus, the newborn, and the adult animal, with previously reported findings on the immature fetus, we draw two conclusions: first, that there is a gradually increasing resistance to infection with this virus during intrauterine development, with but little change thereafter; and second, that at the time of birth there is a sudden loss of infectibility by routes other than the intranasal. These results illustrate then the benefits which may accrue if one projects into the period of antenatal life studies dealing with the age factor in relation to susceptibility to infection. It is implied that data collected from observations of the postnatal animal alone are of necessity incomplete and may be misleading. PMID- 19871048 TI - QUANTITATIVE ASPECTS OF HOMOLOGOUS AND HETEROLOGOUS ACTIVE IMMUNITY TO STRAINS OF THE VIRUS OF EPIDEMIC INFLUENZA. AB - When mice are immunized by one intraperitoneal inoculation with active or inactive influenza virus (strain PR8, W.S., and Melbourne) the quantity required for protection against heterologous strains is about 10 times the homologous minimal immunizing dose. Three injections increase the immunity to all strains, but the ratio between the homologous and heterologous minimal immunizing dose is not altered. Swine influenza virus given intraperitoneally fails to immunize against human strains unless the quantity injected is 1,000 times the minimal amount required for homologous immunity. Intranasal immunization of mice with 1/100 M.L.D. of attenuated ferret passage strains PR8 and Philadelphia, or the tissue culture strain of swine influenza, gives a solid resistance to infection with heterologous strains. When smaller amounts of virus are given intranasally, strain specificity becomes more apparent, and with minimal doses the immunity may be effective only against the homologous and closely related strains. PMID- 19871049 TI - INFECTIOUS CATARRH OF THE ALBINO RAT : I. EXPERIMENTAL TRANSMISSION IN RELATION TO THE ROLE OF ACTINOBACILLUS MURIS. AB - A disease syndrome referred to as infectious catarrh, encountered under natural conditions of exposure in a rat colony, was transmitted to selected animals and maintained for 5 years by nasal instillation or contact. During this period 37 passages were made in 156 rats, the rates of pneumonia, otitis media, and rhinitis being 28, 63, and 87 per cent, respectively. After the 12th passage, Brucella bronchiseptica and Actinobacillus muris (B. actinoides var. muris), which were originally present, were no longer cultivable from infected rats. By reason of the maintenance of infectious catarrh in the absence of the latter and also because of its non-invasiveness on nasal instillation, it is now believed that Actinobacillus muris is of no direct etiological significance. PMID- 19871050 TI - INFECTIOUS CATARRH OF THE ALBINO RAT : II. THE CAUSAL RELATION OF COCCOBACILLIFORM BODIES. AB - Evidence is presented that infectious catarrh of the rat is caused by Gram negative coccobacilliform bodies which resemble the agents of fowl coryza and mouse catarrh. These bodies were demonstrable microscopically in at least 90 per cent of the exudates from the nasal passages and middle ears. The characteristic syndrome was reproduced in selected rats by the nasal instillation of pure tissue culture growths and was maintained for 10 successive passages by the injection of exudate. The experimentally produced disease was also communicable by direct contact. The biological characteristics of the specific bodies are discussed in relation to the organisms of the pleuropneumonia group. PMID- 19871051 TI - THE ISOLATION OF THE BLOOD GROUP SPECIFIC B SUBSTANCE. AB - The isolation of group specific B substance from human stomach juice is described. The substance is carbohydrate-like in nature and is as potent as the carbohydrate-like substance group A isolated from commercial pepsin and peptone respectively. PMID- 19871052 TI - STUDIES ON THE MECHANISM OF VOMITING PRODUCED BY STAPHYLOCOCCUS ENTEROTOXIN. AB - THE EMETIC ACTION OF STAPHYLOCOCCUS ENTEROTOXIN WAS TESTED ON YOUNG AND ADULT CATS UNDER VARIOUS EXPERIMENTAL CONDITIONS WITH THE FOLLOWING RESULTS: 1. No direct action on isolated intestinal strips was observed. 2. Emesis resulted following intravenous, intracardial, and intraperitoneal injections, but failed to appear subsequent to oral, subcutaneous, or intramuscular administration. 3. Emesis occurred following (a) celiac ganglionectomy, (b) gastrectomy, (c) spinal cord transection at T(2) or caudad, and (d) unilateral vagotomy. 4. Mild retching movements and rarely emesis resulted subsequent to enterotoxin injection following (a) double vagotomy, (b) abdominal evisceration, and (c) spinal cord transection at C(7). 5. Emesis never occurred following (a) destruction of the vomiting center, (b) injection of enterotoxin into the fourth ventricle over the vomiting center, and (c) transection of the central nervous system between the anterior border of the pons and the posterior border of the hypothalamus. 6. Morphine inhibited, ergotoxine inhibited or delayed, while atropine and pentobarbital had little or no effect on emesis due to enterotoxin injection. These experiments indicate that the action of staphylococcus enterotoxin on peripheral sensory structures is of greater importance in the initiation of emesis than direct action of the enterotoxin on the vomiting center. The principal pathways of the afferent and efferent impulses are described. PMID- 19871053 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : III. THE EFFECT OF PURIFIED ENZYMES ON ELEMENTARY BODIES OF VACCINIA. AB - The effects of a number of crystalline and highly purified enzymes on elementary bodies of vaccinia are reported. These effects have been followed by determination of amino nitrogen, staining reaction, and studies of infectivity. Pepsin, at a pH which inactivates the virus, results in its solution and rapid release of amino nitrogen. Crystalline trypsin, chymotrypsin, carboxypeptidase, and ribonuclease are without appreciable effect on the virus. Papain within a short time produces profound alteration in the staining reaction of the elementary body with release of amino nitrogen accompanied by complete inactivation of the virus. This reaction is not shared by crystalline ficin, another plant papain, or by cathepsin, an intracellular proteinase analogous to plant papains but of animal origin. PMID- 19871054 TI - STUDIES OF THE TRANSMISSIBLE AGENT OF THE ROUS CHICKEN SARCOMA I : PRECIPITATION WITH BASIC PROTEINS. AB - The viscosity of Rous sarcoma extracts can be reduced with a polysaccharide enzyme isolated from pneumococcus or testis without destruction of the active agent and thus more concentrated active filtrates can be obtained. The active agent can be precipitated with basic proteins. The basic protein can be separated from the components originally coming from the tumor filtrate by electrophoresis. PMID- 19871055 TI - THE BEHAVIOR OF RENAL BLOOD FLOW AFTER PARTIAL CONSTRICTION OF THE RENAL ARTERY. AB - 1. Studies have been made of the behavior of renal blood flow after partial constriction of the renal artery in twenty-four dogs. 2. When reduction in renal blood flow is produced by partial constriction of the renal artery, a readjustment of flow in the direction of normal occurs within a few minutes, subsequent constriction being again followed by a return of flow toward normal until the artery is markedly constricted. 3. Renal blood flow after marked constriction of the artery becomes extremely susceptible to the vasoconstrictive action of small doses of adrenalin, and flow may cease with larger doses for a considerable period of time. 4. Arterial hypertension of significant degree may follow partial constriction of one renal artery during brief experiments when adrenalin in addition has been administered. 5. Further evidence is presented in favor of the concept that the renal circulation enjoys a control independent of systemic arterial pressure. PMID- 19871056 TI - A STUDY OF THE NEUROTROPIC TENDENCY IN STRAINS OF THE VIRUS OF EPIDEMIC INFLUENZA. AB - The demonstration by Stuart-Harris that the W.S. strain of epidemic influenza virus can induce a fatal nervous disease in mice has been confirmed. In contrast, however, no previous period of adaptation to chick embryonic brain was required. By serial brain to brain passages in mice originally inoculated with the virus cultivated in the usual chick embryo culture medium a fatal disease, essentially meningeal in character, is produced. The Melbourne strain has been similarly enhanced while other strains have failed to reveal any neurotropic tendencies. The evidence indicates that the neurotropic characteristic is present in the two strains as an inherent quality which is quantitatively heightened and does not represent the acquisition of a property not previously present. PMID- 19871057 TI - THE ANTIGENIC POTENCY OF EPIDEMIC INFLUENZA VIRUS FOLLOWING INACTIVATION BY ULTRAVIOLET RADIATION. AB - A study of the antigenic potency of influenza virus inactivated by ultraviolet radiation has been made. Virus so inactivated is still capable of functioning as an immunizing agent when given to mice by the intraperitoneal route. In high concentrations inactivated virus appears to be nearly as effective as active virus but when quantitative comparisons of the immunity induced by different dilutions are made, it is seen that a hundredfold loss in immunizing capacity occurs during inactivation. Virus in suspensions prepared from the lungs of infected mice is inactivated more rapidly than virus in tissue culture medium. A standard for the comparison of vaccines of epidemic influenza virus is proposed. PMID- 19871058 TI - QUANTITATIVE STUDIES OF PROSTATIC SECRETION : II. THE EFFECT OF CASTRATION AND OF ESTROGEN INJECTION ON THE NORMAL AND ON THE HYPERPLASTIC PROSTATE GLANDS OF DOGS. AB - Cystic hyperplasia of the prostate occurs spontaneously in senile dogs only when they possess physiologically effective amounts of androgenic hormone. The cysts are closely grouped and radially arranged in a conical manner with the base of the cone at the periphery of the gland. Flattened and columnar epithelium, varying from about 5 to 25micro are seen in each cyst. The cysts communicate with the urethra by way of ducts. Both normal and cystic prostates undergo marked atrophy when the testes are removed, the chief difference 3 months after orchiectomy being the persistence of slightly dilated clefts and spaces at the site of the former cysts in the senile state. In the castrate dog whose prostate gland is being reconstructed as result of the influence of daily injections of androgen, certain doses of estrogen prevent increase of secretion and still larger doses greatly depress the output of the gland. In dogs so treated by daily injections of testosterone propionate, 10 mg., the amount of secretion is maintained from day to day at a level by daily injections of stilbestrol, 0.4 to 0.6 mg. and greatly depressed by doses of 1 to 1.5 mg. When the larger amounts of estrogen are used, together with androgen, squamous metaplasia occurs in the posterior lobe of the prostate while the epithelium of the acini decreases in height to cuboidal or low columnar form; these histological signs of activity of both androgen and estrogen on the prostate show that inhibition of the male hormone by stilbestrol is incomplete at these ratios. In dogs with either normal or cystic prostate glands, the prostate decreases in size when estrogen is injected in amounts to depress prostatic secretion profoundly. The gland is maintained in an atrophic state and overdosage avoided by controlled periodic injections of stilbestrol until secretion is reduced to the minimum, followed by free intervals, the estrogen being again administered when secretion measurably increases. The shrinkage is related to depression of male hormone production. Overdosage of estrogen causes the prostate gland of dogs to enlarge, and structures of the posterior lobe and utriculus respond first and most markedly with metaplasia caused by this material. The prostatic enlargement does not resemble the common cystic hyperplasia of senile dogs. Metaplasia rapidly disappears from the prostate, and the epithelial structures quickly return to normal when estrogen is discontinued and androgen is administered. PMID- 19871059 TI - THE ETIOLOGY OF HYPERTENSION DUE TO COMPLETE RENAL ISCHEMIA. AB - 1. Perfusates of totally ischemic kidneys of cats contain a pressor substance which is not present in the perfusates of normal kidneys, ischemic hind limbs, or ischemic gravid uteri. 2. The pressor material in ischemic renal perfusates originates directly in the kidney as a result of complete ischemia. 3. The pressor principle contained in ischemic renal perfusates is the cause of the hypertension which follows the reestablishment of circulation in completely ischemic kidneys, since perfusates of unreleased completely ischemic kidneys contain more pressor material than perfusates of released ischemic kidneys of the same animal. 4. The pressor principle in ischemic renal perfusates is presumed to be renin for the following reasons, (a) Both substances are destroyed by boiling, (b) Both substances induce tachyphylaxis. (c) The configuration of both pressor curves is identical, (d) The pressor action of both is not reversed by 933F, proving they are not epinephrine-like substances. (e) When incubated with plasma, both form a heat-stable pressor substance. (f) The pressor effect of both is uninfluenced by a previous injection of cocaine, (g) Unreleased, completely ischemic kidneys yield more pressor material on extraction than do released ischemic kidneys of the same animal. 5. The perfusates of blood-free ischemic kidneys contain more renin than those of blood-filled ischemic kidneys. 6. A method is described by which the power of various substances to inhibit or enhance the production of renin in the ischemic kidney may be tested. 7. A small amount of the heat-stable pressor substance, presumably angiotonin or hypertensin, is formed by the reaction of the pressor material (renin) and plasma in the vessels of the kidney during the period of complete ischemia. PMID- 19871060 TI - A STUDY OF QUANTITATIVE CHANGES OF THE SHOPE RABBIT PAPILLOMA VIRUS AT THE SITE OF INOCULATION IN THE SKIN OF THE COTTONTAIL AND DOMESTIC RABBIT. AB - By excising after varying intervals the site of inoculation of the rabbit skin injected intracutaneously with the Shope papilloma virus and titrating its virus content, it has been shown that demonstrable active virus disappears from the skin within approximately 24 hours. The disappearance of most of the virus within such a short time as 15 to 60 minutes makes a transportation of virus from the site of inoculation as a responsible factor unlikely. The rate of disappearance seems to be the same both in the domestic and in the cottontail rabbit. PMID- 19871061 TI - THE RELATIONSHIP BETWEEN SPREADING FACTOR AND HYALURONIDASE. AB - A comparative study of spreading factor and hyaluronidase in preparations from various sources revealed the following points of similarity and dissimilarity in the two reactions. 1. Similarities: (a) All preparations containing hyaluronidase also produced spreading. (b) Heating at 65 degrees and 100 degrees C. for 30 minutes produced a comparable effect on both reactions. (c) The demonstration of the presence of hyaluronic acid in skin offers a plausible explanation for the mechanism of spreading on the basis of hyaluronidase activity. 2. Dissimilarities: (a) No parallelism was observed in the degree of activity of spreading factor and hyaluronidase in the same preparations. (b) All preparations which produced spreading did not contain hyaluronidase. (c) Antisera to hyaluronidase preparations specifically and completely inhibited the activity of the homologous enzyme but did not inhibit the spreading factor in the same preparations. The significance of the similarities and dissimilarities between the two reactions is discussed. It is concluded that while hyaluronidase may play a role in the spreading reaction the phenomenon is a complex one and cannot be explained on the basis of a simple chemical reaction. PMID- 19871062 TI - QUANTITATIVE EXPERIMENTS WITH ANTIBODIES TO A SPECIFIC PRECIPITATE. I. AB - 1. Rabbits were injected with the washed specific precipitate from Type II antipneumococcus horse serum. Antibody in the resulting antiserum was determined by the quantitative agglutinin method using various specific precipitates as antigens. 2. Suspensions of Types I and II antipneumococcus horse specific precipitates, as well as the specific precipitates derived from Type VIII Pn (anti-C portion), and H. influenzae horse antisera were found to remove the same amount of antibody from the immune rabbit serum. 3. Purified antibody solutions prepared by dissociation methods from Types I and II antipneumococcus horse sera were found to remove the same quantity of antibody as did the homologous specific precipitates. 4. Specific precipitates from anti-crystalline egg albumin and anti diphtheria horse sera were found to remove only a fraction of the antibody. The reasons for this are discussed. 5. A specific precipitate prepared from pepsin digested Type I anti-pneumococcus horse serum removed all of the antibody to the homologous antigen from the rabbit anti-precipitate serum, but followed a different quantitative course. 6. From the quantitative course of these reactions and from experiments with specific precipitates from anti-Pn rabbit and pig sera it is concluded that the only antigenic specificity demonstrable for the antibodies investigated was that due to their common origin, and that the groupings responsible for their antibody function constitute either a small part of the total protein molecule or else are non-antigenic. PMID- 19871063 TI - STRUCTURAL AND FUNCTIONAL TRANSFORMATIONS IN THE TUBULAR EPITHELIUM OF THE DOG'S KIDNEY IN CHRONIC BRIGHT'S DISEASE AND THEIR RELATION TO MECHANISMS OF RENAL COMPENSATION AND FAILURE. AB - 1. The wall of the proximal convolution in chronic canine nephritis is composed of various types of epithelial cells which can be recognized as definite structural types from their cytological characteristics. 2. The function of these cell types, as tested by their reaction to the administration of trypan blue, varies with their structural constitution. 3. As a result of the varied cellular content of its wall the abnormal proximal convolution handles trypan blue by mechanisms which differ both quantitatively and qualitatively from those of the normal convolution. 4. A distinguishing characteristic of the decompensated kidney in chronic canine nephritis is the inability of its epithelium to concentrate trypan blue within its cells and to prevent diffusion of the dye from the lumen into the tubule wall. 5. It follows: (a) (from conclusion 3), that it cannot be assumed that the renal mechanisms concerned with other substances are not unaltered and that comparisons of blood and urine concentrations (clearances) have similar significance in the normal and nephritic kidney; (b) (from conclusion 4), that tubular dysfunction may play a part in the ultimate failure of the compensating kidney in all forms of chronic Bright's disease where the tubule walls are similarly affected. PMID- 19871064 TI - EXPERIMENTAL INFECTION WITH INFLUENZA A VIRUS IN MICE : THE INCREASE IN INTRAPULMONARY VIRUS AFTER INOCULATION AND THE INFLUENCE OF VARIOUS FACTORS THEREON. AB - Following intranasal inoculation of influenza A virus (strain PR8) there is a rapid increase of the virus in the lungs which with large doses reaches a maximum within 24 hours. With smaller doses, although the proportional increase is greater, the maximum concentration is not reached until 48 hours following inoculation. If a lethal dose is administered, the ultimate concentration of the virus in the lungs is the same, irrespective of the size of the dose. If a sublethal dose is given, the titer of the virus in the lungs does not achieve the titer reached in mice receiving a lethal dose. Within 48 hours following inoculation of a sublethal dose the lungs of a mouse may contain at least 76,000 M.L.D., yet the mouse survives. The intranasal instillation of sterile fluid (distilled water, varying concentrations of NaCl, broth, or 10 per cent normal serum) into a mouse sublethally infected produces a sharp rise in the virus content of the lung usually followed by death within 3 to 8 days. If, however, the instillate consists of 10 per cent immune serum, there is no rise in the virus titer, and no apparent harm results from the instillation. The implications of these phenomena are discussed and an hypothesis presented to explain their occurrence. PMID- 19871065 TI - A COMPARISON OF CUTANEOUS SENSITIZATION AND ANTIBODY FORMATION IN RABBITS IMMUNIZED BY INTRAVENOUS OR INTRADERMAL INJECTIONS OF INDIFFERENT OR HEMOLYTIC STREPTOCOCCI AND PNEUMOCOCCI. AB - 1. Rabbits that had received repeated intravenous injections of heat-killed indifferent streptococci with no resulting sensitization were subsequently made skin-sensitive to them by repeated intracutaneous injection of heat-killed vaccine. 2. Serum agglutinins and precipitins developed earlier in rabbits that had received repeated intravenous injections of killed streptococci and pneumococci than in those injected intracutaneously. However, when such injections were continued over a longer period, the antibodies in both groups of animals reached a similar level. 3. Species specific agglutinins reached about the same level after either intracutaneous or intravenous injections of heat killed Type I(S) pneumococcus vaccine. Type specific agglutinins were present only in the intravenously injected animals after 33 days but were present in all the animals after 63 days although the titres were somewhat lower in those injected intradermally. Both groups developed precipitins which were only slightly less in the intradermally injected rabbits. 4. These experiments indicate that rabbits intravenously injected with heat-killed streptococci can be made highly skin-sensitive in the same manner as animals injected intracutaneously and that they are not immune or refractory to skin sensitization. When antigen was injected either intracutaneously or intravenously into rabbits for a fairly long time, the amount of circulating antibody in both groups was approximately equal. PMID- 19871066 TI - INTERMITTENT TAKE-UP OF FLUID FROM THE CUTANEOUS TISSUE. AB - Methods have been devised to bring microscopic amounts of fluid into contact with cutaneous connective tissue, under pressure or without pressure, in such a manner that it enters neither blood capillaries nor lymphatics directly. The take-up of fluid brought into contact with the tissues in this way has been measured and its characteristics studied. Elaborate control tests, here described and discussed, have indicated the possible errors in the employment of these methods. Locke's or Tyrode's solutions brought into contact with the cutaneous tissues, by the method described and at atmospheric pressure, pass into the tissue intermittently. Forced into the skin by pressures of 1.0 to 2.0 cm. of water the take-up is still intermittent in character. From this it follows that either the absorption of interstitial fluid from localized regions is periodic or the movements of interstitial fluid are influenced by intermittent physiological changes. PMID- 19871067 TI - REDUCTION OF ARTERIAL BLOOD PRESSURE OF HYPERTENSIVE PATIENTS AND ANIMALS WITH EXTRACTS OF KIDNEYS. AB - 1. Extracts of kidneys have been prepared containing a substance which lowers arterial blood pressure for prolonged periods in patients with essential and malignant hypertension, and in hypertensive dogs and rats. 2. Several different chemical procedures are proposed for the preparation of the extract. The best one has not been decided upon. 3. The quantity of original fresh whole kidney required to yield enough extract to lower blood pressure from hypertensive levels (200 mm. Hg mean pressure) to normal levels is roughly 600 to 900 gm. in dogs within 4 to 8 days. In hypertensive patients the yield from 700 to 1000 gm. daily for several weeks may be necessary. 4. Lowering of the blood pressure too rapidly in animals results in a shock syndrome which may be fatal. If overdosage is avoided, no appreciable rise in blood urea nitrogen occurs, nor do other signs of toxicity appear. 5. Lowering of blood pressure to nearly normal levels has been accomplished in 60 hypertensive dogs, and in some of these it has been allowed to rise and was again reduced as many as five times. Similar results have been obtained with hypertensive rats. 6. Six patients with essential hypertension have been treated resulting in prolonged reduction of blood pressure. Clinically the patients appear improved. 7. Five patients with malignant hypertension have been treated, with reduction of the blood pressure in all instances. One patient was treated despite urea clearance of 5 per cent of normal. His blood pressure was sharply reduced, but death in uremia occurred. The second patient also exhibited sharp reduction of pressure and died after treatment was discontinued. The other three are much improved after treatment, as indicated by increase in vision and mental activity, loss of dyspnea, improvement in the electrocardiogram, etc. 8. The length of time the blood pressure remains lowered varies greatly in both animals and man. The trend is usually upwards after discontinuing treatment for 4 to 6 days. 9. Increasing experience with this treatment suggests that it is of value in the management of hypertension, but it is yet in the experimental stage. PMID- 19871068 TI - FACTORS INFLUENCING THE INTERMITTENT PASSAGE OF LOCKE'S SOLUTION INTO LIVING SKIN. AB - Minute amounts of Locke's or Tyrode's solution have been brought into contact with the interstitial connective tissue of the skin of the living mouse, at atmospheric pressure, in such a manner that the blood or lymphatic vessels are not entered directly. Under such circumstances these absorbable fluids enter the tissue spontaneously. Entrance is strikingly intermittent, not continuous, and so too when very slight pressures are brought to bear on the fluids (1). Hyperemia of the tissues, with accompanying dilatation of the blood vessels, increases the entrance of fluids at atmospheric pressure but it is still intermittent. By contrast, venous obstruction leads to intermittent backflow into the apparatus, but reflex hyperemia, following release of the obstruction, is attended by an increase of flow into the tissues in spite of the great reactive dilatation of vessels. The inflow is also intermittent. If the skin is deprived of circulation, fluid does not enter it at all at atmospheric pressure, though it moves in regularly and continuously if slight pressure is put upon it. Edema-forming fluids, described in the text, also enter in a continuous manner when forced into the skin of either living or dead animals. So too do serum and sperm oil. The findings indicate that the passage of interstitial fluid into the blood vessels may be intermittent under normal circumstances and its escape from them as well. The observed occurrence of intermittent flow in the blood vessels of several tissues (9, 15-25) will go far to account for the intermittent entrance of fluid into the skin. PMID- 19871069 TI - CIRRHOSIS OF THE LIVER CAUSED BY EXCESS DIETARY CYSTINE. AB - 1. Cystine fed to young albino rats as 10 per cent of the diet resulted in: (a) Portal hemorrhagic necrosis, resembling eclampsia, within 3 or 4 days. (b) A high mortality rate. (c) Fatty infiltration of hepatic cells in all rats surviving the initial acute lesion. (d) Cirrhosis of the liver in rats surviving more than 2 weeks. 2. 5 per cent dietary cystine produced marked fatty infiltration of the liver, followed by portal hemorrhagic necrosis. Cirrhosis was present in one of the two rats on the diet for 6 weeks. 3. The livers of rats fed 5 or 10 per cent cystine diets followed by the McCollum stock diet, showed evidence of residual cellular damage, and of regeneration as shown by mitotic figures. 4. In this series of 30 rats on excess dietary cystine, a renal lesion was found in only one case. PMID- 19871070 TI - THE OCCURRENCE DURING ACUTE INFECTIONS OF A PROTEIN NOT NORMALLY PRESENT IN THE BLOOD : I. DISTRIBUTION OF THE REACTIVE PROTEIN IN PATIENTS' SERA AND THE EFFECT OF CALCIUM ON THE FLOCCULATION REACTION WITH C POLYSACCHARIDE OF PNEUMOCOCCUS. AB - The serum obtained from human beings and monkeys during the acute phase of diverse infections contains a protein which is precipitable by the C polysaccharide of pneumococcus. The distribution of this protein in acute phase serum has been studied, and the effect of calcium on the precipitation reaction with the C polysaccharide is described. Other distinctive features of this reaction are discussed. 1. When heated above 65 degrees C., serum obtained from patients during certain acute infections loses the property of reacting in precipitation tests with the C polysaccharide of pneumococcus. The loss of activity under these conditions occurs at temperatures known to denature many proteins. 2. The reactive component in "acute phase" serum which precipitates with the C polysaccharide is tentatively regarded as a protein. 3. The reactive substance is associated with the albumin fraction of serum. 4. In the reaction between patients' serum and C polysaccharide, flocculation is conditioned by the presence of calcium ions. 5. The following distinctive features of the C-reaction are discussed with reference to known characteristics of antigen-antibody phenomena: (a) the occurrence of the reactive component in blood only during the acute stage of the infection; (b) the lack of specificity of the reaction with respect to the inciting cause of the disease; (c) the presence of the active substance in the albumin fraction of the serum; (d) the action of calcium in producing flocculation. PMID- 19871071 TI - THE OCCURRENCE DURING ACUTE INFECTIONS OF A PROTEIN NOT NORMALLY PRESENT IN THE BLOOD : II. ISOLATION AND PROPERTIES OF THE REACTIVE PROTEIN. AB - Methods are described for isolating a protein commonly present in the blood of patients during the acute phase of various infections which, unlike the normal serum proteins, is precipitable by the C polysaccharide of Pneumococcus. The reactive protein is present in the fraction of serum albumin precipitated by either ammonium or sodium sulfate between 50 and 75 per cent saturation. From this fraction the reactive protein separates out on dialysis against tap water. Following removal of the alcohol-ether-soluble lipids from acute phase serum the reactive protein becomes soluble in tap water, and is no longer precipitable by traces of calcium but still retains its precipitability with the C polysaccharide. PMID- 19871072 TI - THE OCCURRENCE DURING ACUTE INFECTIONS OF A PROTEIN NOT NORMALLY PRESENT IN THE BLOOD : III. IMMUNOLOGICAL PROPERTIES OF THE C-REACTIVE PROTEIN AND ITS DIFFERENTIATION FROM NORMAL BLOOD PROTEINS. AB - The C-reactive protein present in the albumin fraction of the serum of patients during certain acute bacterial infections is highly antigenic upon injection into rabbits. The antiserum thus prepared reacts specifically with this protein and does not react with the proteins of normal human serum. Immunological specificity has been demonstrated by both precipitin and complement-fixation tests. Antiserum prepared in rabbits to the C-reactive protein from human sources also reacts specifically with the similar protein in the serum of monkeys acutely ill with experimental pneumococcus infection. By means of immunological reactions it is possible to detect amounts of reactive protein which are too small to yield a visible precipitate in tests with the C polysaccharide. Certain of the properties are discussed which distinguish the C-reactive protein from the proteins of normal human serum. PMID- 19871073 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMOCOCCAL PNEUMONIA : I. THE ACTION OF TYPE SPECIFIC ANTIBODY UPON THE PULMONARY LESION OF EXPERIMENTAL PNEUMONIA. AB - A uniformly fatal lobar pneumonia was produced in white rats by inoculation of the left main bronchus with virulent Type I pneumococci suspended in mucin. All of the animals succumbed in less than 5 days, half of them dying within 48 hours. In only 5 of 40 rats was the lesion confined to the left lung, and all but one developed pleurisy, pericarditis, or both. All had bacteriemia at the time of death. The pathogenesis of the pulmonary lesion was studied by examining the lungs of 35 rats killed at various intervals following inoculation. The pneumonic process spread rapidly until most of the left lung was involved in 36 hours. Frequent blood cultures showed invasion of the blood stream in a few rats at 6 hours and in over 90 per cent at the end of the first day. The first signs of pleurisy usually appeared at 18 hours. Microscopic examination of the actively spreading lesion revealed three characteristic zones: (1) an outer "edema zone" in which the alveoli contained many pneumococci floating freely in edema fluid, (2) a middle zone where both leucocytes and organisms were present, many of the latter being phagocytized, and (3) an inner zone of advanced consolidation in which the alveoli contained many leucocytes but no organisms and where there were already local areas of early resolution. Study of numerous lesions, at intervals of from 12 to 36 hours after inoculation, indicated that the pneumococci spread into normal alveoli principally by way of the infected edema fluid in the outer zone. Pneumococcus-laden edema fluid in large bronchi and in alveoli beneath the pleura suggested the mode of spread of the infection to other lobes and possibly to the pleural cavity. No adequate explanation could be found for the presence of active phagocytosis in the lungs of animals with bacteriemia and presumably without circulating antibodies, but this conspicuous phagocytic reaction was obviously responsible for the clearing of the central part of the spreading lesion. The action of type specific antibody upon the pulmonary lesion of experimental lobar pneumonia was studied in rats similarly infected but treated with antipneumococcal serum. When injected intravenously in a single dose within 18 hours after inoculation the antiserum was found to protect all of the rats against the otherwise fatal pneumonia. It stopped the spread of the pneumonic lesion, cleared the blood stream of organisms, and prevented the extension of early pleurisy. The antibody caused agglutination and capsular swelling of the pneumococci in the lung, particularly in the edema zone at the margin of the lesion where they were most numerous. Apparently immobilized by agglutination the organisms were overtaken by leucocytes and destroyed by phagocytosis. The phagocytic reaction was greatly accelerated by the specific opsonins of the antiserum, and the pneumococci were destroyed by polymorphonuclear leucocytes before many macrophages appeared in the alveolar exudate. Within a week after treatment resolution of the pulmonary lesion was well in progress. Both horse and rabbit antibody were shown to penetrate the lung, and immune bodies were demonstrated in the alveoli within 10 minutes after the start of treatment. The relation of the observed phenomena to the curative action of anti-pneumococcal serum has been briefly discussed, and it is pointed out that the principal effect of antiserum is to cause immobilization of the pneumococci in the advancing edema zone. Experiments to be reported in a later publication have shown that sulfapyridine exerts a similar effect through a different mechanism. PMID- 19871074 TI - STUDIES ON PHOTO-OXIDATION OF ANTIGEN AND ANTIBODIES. AB - 1. Quantitative precipitin studies indicate that progressive photo-oxidation progressively destroys the antigenic function of egg albumin. 2. Quantitative precipitin reactions of antisera (anti-egg albumin rabbit serum and antipneumococcus Type I horse serum) demonstrate that progressive photo-oxidation causes progressive lowering of the potency of the sera. 3. Quantitative precipitin reactions of the photo-oxidized globulin gamma fraction of anti-egg albumin rabbit serum and of Felton solution of antipneumococcus Type I horse serum show that these specific antibody fractions behave similarly to antibodies in whole sera. 4. Egg albumin whose precipitin reaction is destroyed by photo oxidation no longer causes anaphylaxis in guinea pigs and does not produce precipitins in rabbits. 5. Chemical studies of progressively photo-oxidized egg albumin show a progressive destruction of tryptophane and histidine while tyrosine remains intact and cystine is reversibly oxidized. Sulfhydryl groups can no longer be demonstrated in photo-oxidized egg albumin whose antigenic characteristics are greatly weakened. 6. Similar studies on the globulin gamma fraction of anti-egg albumin rabbit serum and on Felton solution show no diminution of these amino acids in photo-oxidized material whose antigenic properties are destroyed. 7. The non-coagulable nitrogen and the amino nitrogen of egg albumin, antisera, and their specific antibody fractions show but an insignificant increase during photo-oxidation, indicating that the loss of the precipitin reaction is not due to splitting of the respective protein molecules. 8. Electrophoretic studies of egg albumin, antisera, and their specific antibody fractions show that photo-oxidation causes a marked alteration of the pattern of these substrates. 9. Photo-oxidation of proteins causes the formation of aggregates, indicating denaturation. 10. Hematoporphyrin migrates with the albumin fraction of unaltered as well as the photo-oxidized anti-egg albumin rabbit serum and pneumococcus Type I horse serum; in isolated proteins such as egg albumin, globulin gamma, or Felton solution, etc., the dye moves independently of the protein; after progressive photo-oxidation Hp becomes progressively fixed to the protein. Eosin behaves similarly to hematoporphyrin. PMID- 19871075 TI - THE ROENTGEN RADIATION OF PAPILLOMA VIRUS (SHOPE) : I. THE EFFECT OF X-RAYS UPON PAPILLOMAS ON DOMESTIC RABBITS. AB - Virus-induced papillomas (Shope) on domestic rabbits are susceptible to Roentgen rays. The dosage which uniformly brings about their complete and permanent disappearance has been found to be 3600 r (200 kilovolts), whether this dose be administered at one time or fractionally. 60 per cent of the tumors are cured when irradiated with 3000 r. PMID- 19871076 TI - ACTION OF SYNTHETIC DETERGENTS ON THE METABOLISM OF BACTERIA. AB - A study of the effects of synthetic detergents and wetting agents on respiration and glycolysis of Gram-positive and Gram-negative microorganisms has led to the following conclusions. 1. All the cationic detergents studied are very effective inhibitors of bacterial metabolism at 1:3000 concentration, and several are equally active at 1:30,000. Few of the anionic detergents inhibit as effectively as the cationic compounds. 2. Gram-positive and Gram-negative microorganisms are equally sensitive to the action of the cationic detergents. On the other hand, all the anionic detergents included in our studies selectively inhibit the metabolism of Gram-positive microorganisms. 3. The inhibitory action of both types of detergents is influenced markedly by hydrogen ion concentration. Cationic detergents exhibit their maximum activity in the alkaline pH range, and the anionic, in the acid range. 4. Studies of homologous series of straight chain alkyl sulfates and sulfoacetates (C(8) to C(18)) demonstrate that maximum inhibition is exerted by the 12, 14, and 16 carbon compounds (lauryl, myristyl, and cetyl). 5. It has been observed that three lauryl esters of amino acids are powerful inhibitors of bacterial metabolism. To our knowledge, the effects on bacterial metabolism of such cationic detergents (without the quaternary ammonium structure) have not been studied previously. Our results demonstrate that other cationic detergents can exhibit an inhibitory activity comparable to quaternary ammonium compounds. 6. Certain detergents stimulate bacterial metabolism at concentrations lower than the inhibiting values. This effect has been found more frequently among the anionic detergents. PMID- 19871077 TI - UTERINE ADENOMATA IN THE RABBIT : III. SUSCEPTIBILITY AS A FUNCTION OF CONSTITUTIONAL FACTORS. AB - An investigation of uterine adenomata in the rabbit revealed an incidence of 16.7 per cent in the total female population over 2 years of age. However, the incidence varied widely in relation to age, breed, and genetic constitution and closely paralleled that of toxemia of pregnancy with reference to the same constitutional factors. In addition, all of the tumor bearing animals suffered attacks of this disease during their earlier breeding history. The facts suggest that the association of the two disorders occurred as a result of the liver damage incident to toxemia which impaired the function of this organ in relation to estrin inactivation and the concentration of this substance in the blood stream subsequently rose to a carcinogenic level. A consideration of the disparity in the distribution of uterine growths in rabbits and women indicated that the absence of squamous epithelium in the cervix of the rabbit and the greater physiological activity of the endometrium of the fundus in this species were the determining factors. PMID- 19871078 TI - QUANTITATIVE EXPERIMENTS WITH ANTIBODIES TO SPECIFIC PRECIPITATES. II. AB - 1. Antisera have been produced in chickens with specific precipitates from Type II pneumococcus horse and rabbit antisera. 2. Specific precipitates from anti Types I and II pneumococcus horse sera removed the same amount of antibody from the chicken anti-horse specific precipitate serum. Specific precipitates from horse antisera to diphtheria toxin and to crystalline egg albumin removed about one-half of the antibody. 3. Specific precipitates from anti-egg albumin, antipneumococcus C substance, and anti-Type II pneumococcus rabbit sera removed the same amount of antibody from the chicken anti-rabbit specific precipitate serum. 4. No antibody was removed from the chicken anti-horse specific precipitate serum by rabbit specific precipitates or from the chicken anti-rabbit specific precipitate serum by horse specific precipitates. 5. It is concluded that the antigenic specificities of antibodies from the horse and rabbit are not influenced by their particular antibody functions. PMID- 19871079 TI - THE ORIGIN OF PLATELETS : THEIR BEHAVIOR IN THE HEART-LUNG PREPARATION. AB - 1. In heart-lung preparations perfused with heparinized blood, clumping of platelets and a sharp fall in the platelet count occurred in the first 5 to 15 minutes after the external circuit was established. 2. In 10 such preparations surviving from 1 to 4 hours, only one showed a return of the platelet count to the level existing before operation. 3. When platelets were reduced in numbers before the blood was used for perfusion, the count tended to level off after a small recovery, if any. 4. An estimate of clumping showed it to bear an inverse relationship to the platelet recovery. 5. No satisfactory evidence of platelet production in the lungs has been obtained in these studies with heart-lung preparations. 6. The possibility of special factors which may influence platelet formation is discussed. PMID- 19871080 TI - HYALURONIDASES OF BACTERIAL AND ANIMAL ORIGIN. AB - Hyaluronidase has been investigated in various strains of pneumococci and hemolytic streptococci, and in some material of animal origin. The enzyme activity was measured by a viscosimetric method using as a substrate a fluid containing hyaluronic acid as the viscous component, and by the hydrolysis of pure hyaluronic acid into its reducing components. In pneumococci the enzyme was demonstrated in all types and in all strains tested, including smooth and rough forms of Types I, II, III, and VI. In hemolytic streptococci the enzyme from strain H44, group A, reported previously, was further investigated. In this strain, as well as in other hemolytic streptococci containing the enzyme, great variability of the enzyme concentration was found. Furthermore, the enzyme proved to be very labile, giving in the viscosimetric measurements a typical stoppage of the activity initially present. In 13 out of 14 other strains of group A organisms investigated, no enzyme was demonstrable, but the variation in activity in the enzyme-active strains renders the negative findings inconclusive. A very active enzyme, though of great variability, was found in one group C strain. The enzyme was prepared from the leech in confirmation of the work of Claude. The enzyme from testis showed a maximum at pH 4.4 in contrast to the optimum of 5.8 in pneumococcal, streptococcal, and Cl. welchii preparations. The pH curve of the testis enzyme indicated, however, a second optimum coinciding with that of the bacterial enzymes. The hydrolysis further indicated a break at about 50 per cent hydrolysis, indicating primarily the hydrolysis down to aldobionic acid units. The depolymerizing action of testis enzyme is more marked than that of pneumococcal enzyme. The results have been interpreted as due to the presence of two enzymes, one attacking the long chain molecule, the other hydrolyzing the aldobionic acid formed. The enzyme was further prepared from beef spleen. Here the hydrolysis of beta-glucuronides was compared to that of hyaluronic acid. The two actions apparently are catalyzed by two distinct enzymes. Enzyme preparations were further obtained from rabbit skin. Since hyaluronic acid has also been found in the skin, this organ may play a considerable role in the metabolism of hyaluronic acid. In addition to hyaluronic acid, it has been shown that hyaluronidases also hydrolyze the sulfuric acid containing polysaccharide of the cornea. This polysaccharide has previously been characterized as a natural sulfuric acid ester of hyaluronic acid. The pneumococcal enzyme preparations also attacked a polysaccharide acid prepared from submaxillary gland, which is not hyaluronic acid. However, it is believed that this hydrolysis is due to a second enzyme contained in the preparations. The testis enzyme, on the other hand, attacked chondroitinsulfuric acid and also contained a sulfatase. The depolymerizing action of hyaluronidase has been discussed. It is concluded that depolymerization and hydrolysis are probably due to the same enzyme attacking hyaluronic acid. It is suggested that the first attack of the enzyme does not cause an opening of glucosidic linkages. The available evidence indicates that the viscosity of the natural fluids is not due to macromolecules but to micellae formation, and that these micellae are depolymerized by the enzymatic reaction. It is assumed that the depolymerization is due to a primary enzyme-substrate reaction, which in itself is insufficient to open the glucosidic linkages. The latter reaction involves further steps. The relationship between hyaluronidase and "spreading factor" has been discussed anew. Though more data have been reported pointing to the identity of hyaluronidase and "spreading factor," our inability to demonstrate hyaluronidase in streptococcal material of high "spreading" potency, is still a serious obstacle to the unitarian theory. However, it seems possible that the streptococcal material may contain reversibly inactive enzyme which may be reactivated in vivo. PMID- 19871081 TI - NEUTRALIZATION OF INFLUENZA A VIRUS BY HUMAN SERUM. AB - A linear relationship exists between the quantity of human serum used and the quantity of influenza A virus neutralized. By means of this relationship it is possible to determine the maximum quantity of virus which a given human serum can neutralize. This quantity, the neutralizing capacity, is a fixed value and, unlike the serum dilution end point, is independent of the amount of virus used in the neutralization test. PMID- 19871082 TI - A COMPLEX VACCINE AGAINST INFLUENZA A VIRUS : QUANTITATIVE ANALYSIS OF THE ANTIBODY RESPONSE PRODUCED IN MAN. AB - A quantitative study of the antigenicity of various vaccines containing influenza A virus has been made in human beings. A complex vaccine prepared from chick embryos inoculated with both influenza A virus and the X strain of canine distemper virus was found to be more effective than other vaccines in stimulating the production of neutralizing antibodies against the former virus. The increased antibody levels which resulted from the administration of this vaccine remained almost unaltered for at least 5 months. PMID- 19871083 TI - THE ROLE OF RENAL METABOLISM IN HYPERTENSION AND UREMIA. AB - 1. The chemical mediator of renal hypertension is rapidly destroyed by the metabolic activity of the normal kidney. The excretory function of the kidney plays little, if any, role in eliminating the mediator of hypertension. 2. If specific substances are responsible for the uremic syndrome, they are neither produced nor eliminated to any significant extent by the metabolic activity of the kidneys. The elimination of these postulated uremia-producing substances would have to be primarily dependent upon the excretory activities of the kidney. 3. No evidence was obtained to support the view that a unilateral ureterovenous fistula leads to "nephrotoxic" symptoms. PMID- 19871084 TI - CONDITIONAL NEOPLASMS AND SUBTHRESHOLD NEOPLASTIC STATES : A STUDY OF THE TAR TUMORS OF RABBITS. AB - The "warts" which tar elicits on rabbit skin (papillomas, carcinomatoids, frill horns) are true tumors, benign growths expressive of slight yet irreversible deviations of epidermal cells from the normal. The neoplastic condition gives the cells a superiority over their neighbors when both are submitted to the same encouraging influences, and then they proliferate into tumors. Their state entails such disabilities, though, that they are unable to maintain themselves under ordinary circumstances, and consequently growths composed of them disappear when no longer aided. Often the neoplastic cells resume the normal aspect and habit of life long before the tumor mass is gone; and they may persist as part of an apparently normal epidermis, retaining their neoplastic potentialities for months after all signs of the growth have disappeared. In these instances it can be made to appear again, sometimes repeatedly, by non-carcinogenic stimulation of the skin (wound healing, turpentining). There is reason however to suppose that in the end the tumor cells, unless helped, die or are cast off. It is plain that the neoplastic state does not necessarily connote independence of behavior or success in tumor formation. On the contrary it may render cells unable to survive or endow them with powers which they can exert only under favoring conditions. This is the case with the cells composing the tar warts of rabbits. In the lack of such conditions the cells of these growths do not manifest themselves but remain in a subthreshold neoplastic state, whereas if aided they form neoplasms. The deviations from the normal represented by the benign tar tumors of rabbits are slight and limited in character, but further deviations in larger variety may be superimposed upon them, with result in malignant tumors, growths possessed of a greater, though not always absolute, independence. Tar cancers usually come about in this way, by successive, step-like deviations from the normal, and so also do the cancers which derive from virus-induced papillomas as well as many human carcinomas. After cells have become cancerous they frequently undergo further changes, some apparently step-like in character, and all taking the direction of greater malignancy. The hypotheses that tumors are due to somatic mutations and to viruses respectively are discussed in the light of these phenomena. PMID- 19871085 TI - THE EXPERIMENTAL DISCLOSURE OF LATENT NEOPLASTIC CHANGES IN TARRED SKIN. AB - A carcinogenic tar applied to rabbit skin renders many more epidermal cells neoplastic than ever declare themselves by forming tumors. They may be present in large numbers and persist for a considerable time after brief tarring, yet give rise to no growths unless encouraged. The stimulus of wound healing will suffice to make some of them multiply and form tumors. No evidence has been obtained, in experiments specifically directed to the point, that the cells which tar renders neoplastic respond in this way because they are possessed of peculiarities not shared by the rest of the normal epithelium. The fact that non-specific stimulation (as e.g. wound healing) may act as the deciding influence in tumor formation brings out the need for a sharp distinction between the forces which induce neoplastic change and those which determine, or prevent, its realization in terms of a tumor. The distinction is vital to the appraisal of the many carcinogenic substances worked with nowadays. The ability of tumor cells to lie latent for long periods and respond to non-carcinogenic stimulation by multiplying into growths provides an explanation of those clinical instances in which cancer appears rapidly after acute injury to tissue that had seemed normal. PMID- 19871086 TI - EXPERIMENTAL HYPOALBUMINEMIA : ITS EFFECT ON THE MORPHOLOGY, FUNCTION, AND PROTEIN AND WATER CONTENT OF THE LIVER. AB - 1. Adult dogs maintained for 6 weeks upon a carrot-protein-deficient diet exhibited a progressive fall in the serum protein confined entirely to the albumin fraction. The degree of hypoalbuminemia was pronounced, i.e. a fall from 3.75 to 2.00 gm. per cent. 2. Parallel microscopic changes in the liver were observed which consisted of a gradual loss in the stainable cytoplasm producing extensive vacuolization. This vacuolization was not due to the accumulation of fat or of glycogen as shown by chemical analyses as well as by stained sections of the livers. 3. The histological changes in the livers were assumed to be due to a loss of protein inasmuch as there was a parallel fall in the protein content of the liver pari passu with the fall in the serum albumin of the blood. This assumption is made more probable by the fact that the water content of the liver increased as the protein content decreased. 4. Liver function, as measured by the excretion of iso-iodeikon, fell with the fall of the serum albumin thus indicating the production of hepatic insufficiency by the protein deficient diet. 5. These observations are discussed in relation to the question whether the liver is the site of formation or of storage of serum albumin. Certain other, particularly therapeutic, implications are also discussed, i.e. the importance of a high protein intake in patients with liver disease. PMID- 19871087 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : IX. SKIN SENSITIZATION INDUCED BY INJECTION OF CONJUGATES. AB - Experiments with guinea pigs are described which show that under special experimental conditions the intraperitoneal injection of conjugates made with homologous erythrocyte stromata leads to typical skin sensitization of the contact type towards the respective simple chemicals, namely picryl chloride or 2,4-dinitrofluorobenzene. Therefore such sensitivity can be brought about not only by low molecular chemical compounds but by a material which must be regarded as a typical antigen. PMID- 19871088 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : XIV. THE EFFECT OF INTERMITTENT RENAL ARTERIAL OCCLUSION ON THE BLOOD PRESSURE OF THE DOG. AB - By means of a silver chain attached to a silver ring around the main renal artery, intermittent renal arterial occlusion, up to 30 minutes daily, was practiced for as long as 5 months in unilaterally nephrectomized dogs. This did not result in the development of persistently elevated blood pressure. Persistent moderate constriction of the renal artery of such animals by a silver clamp, after intermittent temporary occlusion had failed to affect the blood pressure, produced the usual rise of blood pressure, without accompanying significant impairment of renal excretory function. When the renal artery accidentally became persistently constricted to a great degree, or actually occluded, or if occlusion was deliberately produced by continuous pulling of the chain, hypertension and renal insufficiency (the malignant phase) quickly developed. The results do not lend support to the view that brief daily periods of renal ischemia from intrarenal vasospasm, or from any other cause, can produce persistent hypertension of renal origin. PMID- 19871089 TI - EXPERIMENTAL POLIOMYELITIS IN CERCOPITHECUS AETHIOPS SABAEUS (THE GREEN AFRICAN MONKEY) BY ORAL AND OTHER ROUTES. AB - The green African monkey, Cercopithecus aethiops sabaeus, has been infected with experimental poliomyelitis after feeding artificially contaminated food. This species is also highly susceptible to intracerebral, intranasal, and intraabdominal inoculations. In one experiment with a human stool from a case of poliomyelitis, Cercopithecus was more susceptible to intranasal and to intraabdominal inoculation than Macaca mulatta. PMID- 19871090 TI - HETEROLOGOUS TRANSPLANTATION OF MAMMALIAN TUMORS : I. THE TRANSFER OF RABBIT TUMORS TO ALIEN SPECIES. AB - A series of experiments was undertaken in an attempt to transplant rabbit tumors to animals of alien species using the anterior chamber of the eye as an inoculation site. The uterine tumor H-31 and the breast tumors T-36 and B-240 were successfully transplanted to all the various animals tried, including guinea pigs, swine, goats, and sheep, and the H-31 and T-36 tumors were maintained by serial transfer in the two first species. On the other hand, all attempts to transfer the Brown-Pearce tumor to guinea pigs were unsuccessful. The growth characteristics of the transplanted tumors were generally similar to those observed in the natural host, but noteworthy exceptions occurred. The tumors obtained a blood supply from the foreign host and invaded the periorbital tissues but did not metastasize. Histologically, the cellular morphology of the rabbit tumors was retained, but variations in parenchymal-stromal relations characterized the form of growth in different species. PMID- 19871091 TI - HETEROLOGOUS TRANSPLANTATION OF MAMMALIAN TUMORS : II. THE TRANSFER OF HUMAN TUMORS TO ALIEN SPECIES. AB - The successful heterologous transplantation of several human tumors, including a breast carcinoma, a carcinoma of the colon, a melanotic sarcoma, and a fibrosarcoma, has been reported. Histologically, the appearance of the transplants of the carcinomata differed from that of the spontaneous tumors, but the directly observed growth of the transplanted fragments together with the presence of invasion in microscopic sections afforded proof of successful transfer. Transplants of the sarcomata, on the other hand, were morphologically identical with the primary tumors, and in the case of the fibrosarcoma serial passage to a second generation of animals was successfully performed. PMID- 19871092 TI - A NEW GROWTH FACTOR REQUIRED BY CERTAIN HEMOLYTIC STREPTOCOCCI. AB - A new factor essential for the growth of hemolytic streptococci of Lancefield's group A has been demonstrated. It has not been possible to identify this factor with any other known growth factor. The active substance occurred in liver as a water-soluble, alcohol-insoluble, non-dialyzable material. It could be rendered dialyzable by treatment in strong alcohol with HCl, but not by many less drastic procedures. The most active concentrates prepared gave a maximal effect when approximately 10 gamma per cc. were added. PMID- 19871093 TI - THE EFFECT OF A POLYSACCHARIDE-SPLITTING ENZYME ON STREPTOCOCCAL INFECTION. AB - 1. Confirming the observations of other experimenters, it has been found that group A hemolytic streptococci produce a capsule containing a polysaccharide which is similar to, if not identical with, certain high molecular weight sugars found in the mammalian body. 2. Leech extract possesses a powerful enzyme capable of splitting one of the linkages in this polysaccharide and of decapsulating group A and group C hemolytic streptococci in vitro and in vivo. 3. Mice and guinea pigs can be protected from intraperitoneal infection with a virulent group C streptococcus by the intraperitoneal administration of leech extract. In contrast there is little protective action of leech extract in mice infected with group A hemolytic streptococci. 4. The protective effect of leech extract against streptococcal group C infection is probably due to the removal of the capsule in vivo. 5. The capsule of mouse virulent group C streptococci plays a major role in the virulence of that microorganism, while the capsule of certain mouse virulent group A streptococci plays little, if any, role in virulence, at least when the infection is intraperitoneal in the mouse. PMID- 19871094 TI - HEREDITARY TRANSMISSION OF THE WESTERN TYPE OF EQUINE ENCEPHALOMYELITIS VIRUS IN THE WOOD TICK, DERMACENTOR ANDERSONI STILES. AB - The Western type of equine encephalomyelitis virus can be passed as an hereditary infection in a tick of the family Ixodidae, Dermacentor andersoni Stiles. Under experimental conditions, this virus has been carried in this tick for two successive generations, possibly for a third, passing certainly once, and possibly twice, from the female through the eggs to the larvae. The virus carrying larval, nymphal, and adult stages of this tick, furthermore, are capable of infecting susceptible hosts when they are permitted to feed on them. PMID- 19871095 TI - THE EFFECT OF TYROSINASE ON EXPERIMENTAL HYPERTENSION. AB - 1. The intravenous injection of tyrosinase, a phenolic oxidase obtained from mushrooms, consistently lowers the blood pressure of rats made hypertensive by three different methods, while on the average not affecting the blood pressure of normal animals. 2. The intravenous and intramuscular injection of tyrosinase lowers blood pressure in dogs made hypertensive by the method of Goldblatt, while affecting that of normal ones to a less extent. 3. Tyrosinase inactivates renin, angiotonin, Victor's pressor substance, adrenalin, and tyramine in vitro, and alters the response of the blood pressure to these substances in rats and dogs. 4. Renal function of hypertensive dogs is not depressed when the blood pressure is lowered by tyrosinase. 5. Tyrosinase is an effective substance for combating experimental arterial hypertension. It is probable that some phenolic substance present in hypertension is altered. PMID- 19871096 TI - THE INTERACTION OF HOST AND BACTERIUM IN THE DEVELOPMENT OF COMMUNICABILITY BY STREPTOCOCCUS HAEMOLYTICUS. AB - An epidemic of infections due to group A Streptococcus haemolyticus type 12 originated in an infant with bronchiectasis, and involved children and nurses. Some of the children spread contagion; the nurses did not spread contagion. The children who spread contagion had few or no recognizable type 12 organisms in their throats; most of the nurses had type 12 predominant in their throat flora. Two children who spread contagion had non-hemolytic streptococci in their throat flora, which became hemolytic on cultivation and proved to be type 12. Four children had in their throat flora hemolytic type 12 streptococci which became non-hemolytic when grown in fluid media containing serum. These infants appeared to act as disseminating hosts in which the pathogen developed communicability and at the same time became morphologically and physiologically labile. The labile streptococci gave rise to atypical forms whose requirements for rapid reproduction (as tested in vitro) were similar to those existing in the human host. The hypothesis presented is that the genesis of communicability depends on the coexistence of two conditions: a transmitting host lacking in restraining influences, permitting the acquisition of physiological lability by the microorganism; and the development of adaptive mechanisms in the bacterial cell, facilitating survival under atmospheric conditions and subsequent colonization in the environment of human tissues. PMID- 19871097 TI - BLOOD PLASMA PROTEIN PRODUCTION AS INFLUENCED BY VARIOUS DEGREES OF HYPOPROTEINEMIA AND BY AMINO ACIDS. AB - When blood plasma proteins are depleted by bleeding with return of the washed red blood cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal low protein diet. These dogs are clinically normal but their resistance to infection is distinctly below normal. Introduction of variables into this standardized existence gives information relative to plasma protein production. Plasma protein production under these conditions with a plasma protein concentration of 3.5 to 4.2 gm. per cent is relatively constant. As the plasma protein concentration rises the plasma protein removed falls rapidly (Table 1). At 4.6 gm. per cent the protein removed is less than 50 per cent of the amount removed at a plasma protein level of 4.0 gm. per cent. Cystine appears to be an important amino acid for plasma protein formation. This shows in Table 2 and is supported by data coming from published experiments. These experiments related to the factors which control plasma protein production bear on the problems of shock, hemorrhage, and protein wastage and their treatment by plasma injections which hold the attention of surgeons and physiologists at the moment. Again we would emphasize the fluidity of body protein including plasma protein-an ebb and flow between protein depots and plasma protein-a "dynamic equilibrium" of body protein. A discussion of the passage of large protein molecules through cell borders is submitted. PMID- 19871098 TI - STUDIES ON INFLUENZA VIRUS : THE COMPLEMENT-FIXING ANTIGEN OF INFLUENZA A AND SWINE INFLUENZA VIRUSES. AB - Influenza complement fixation tests designed for use with ferret serum are described. Complement-fixing antigens derived from influenza ferret lungs were unsatisfactory due to their low content of soluble antigen; those prepared from mouse lungs or developing chick embryo membranes proved to be better antigenically and were reliable when the various reagents in the test were properly adjusted to eliminate non-specific fixation of complement. The results of cross complement fixation tests indicated that the soluble antigens of the PR8 and W.S. strains of influenza A virus were closely similar, if not identical. They indicated also that the soluble antigen of swine virus possessed components present in the antigens of the human strains of virus. PMID- 19871099 TI - THE QUANTITY OF IRRADIATED NON-VIRULENT RABIES VIRUS REQUIRED TO IMMUNIZE MICE AND DOGS. AB - In the experiments described above, we found with respect to tissue culture rabies virus that 1 cc., which contains approximately 50,000 mouse intracerebral lethal doses, properly irradiated, was required to immunize a mouse; 500 cc., which contain 25,000,000 doses, were required to immunize a 20 pound beagle dog. Tissue culture virus concentrated ten times proved capable of immunizing mice in a dose one-tenth as large as that required for unconcentrated culture virus. Brain virus suspensions were centrifuged so as to remove a large part of the tissue particles without striking loss in the virulence of the supernatant. The centrifuged supernatants of 1 to 5 per cent brain virus suspensions were irradiated so as to destroy virulence and yet retain immunizing potency. Irradiated supernatants of mouse brain virus proved capable of immunizing mice as well as or better than similar supernatants treated with chloroform. 0.1 cc. of a 1 per cent irradiated dog brain virus containing approximately 50,000 mouse intracerebral lethal doses immunized mice effectively. PMID- 19871100 TI - ORGAN SPECIFICITY OF TISSUES OF THE DOG AND MAN AS SHOWN BY PASSIVE ANAPHYLAXIS IN GUINEA PIGS. AB - The immunization of rabbits for periods of 6 to 8 weeks with sedimented, heat killed vaccines of Pasteurella boviseptica grown in infusion broths made from six different tissues of the dog and seven tissues of man, caused the production of sera containing antibodies for the broths as well as for the bacteria. The broth made from human fibromyoma of the uterus was the least antigenic of all, as indicated by passive anaphylactic tests in guinea pigs. When these animals were prepared by intraabdominal injection with the rabbit antisera and tested 48 hours later by intravenous injection with autoclaved aqueous extracts of a large number of organs of the dog and man, the guinea pigs were found to be passively sensitized so that severe or fatal anaphylaxis was generally obtained with broths made from the homologous organ and in some instances with those prepared from heterologous organs of the same species. In most instances, the injection of broths from heterologous tissues did not desensitize to later injections of that from the homologous tissue. The most organ-specific antisera were those for striated muscle, small intestine (ileum), kidney, placenta, and fibromyoma, and the least so those for whole blood, liver, and lung. The cross-reactions of the antiserum for blood were mostly with extracts of tissues which normally contain large amounts of blood. The presence of Forssman antigen in the tissues of the dog did not interfere with the demonstration of organ specificity by the methods used. In general, the results indicate that the various tissues of man and the dog contain thermostable, water-soluble, organ-specific substances which can be demonstrated by passive anaphylaxis in guinea pigs. The chemical nature of these substances has not been definitely determined, although there are some indications that they are protein split-products, probably proteoses. PMID- 19871101 TI - THE PRODUCTION OF BACTERICIDAL SUBSTANCES BY AEROBIC SPORULATING BACILLI. AB - Several species of aerobic sporulating bacilli recently isolated from soil, sewage, manure, and cheese, as well as authentic strains obtained from type culture collections, have been found to exhibit antagonistic activity against unrelated microorganisms. Cultures of these aerobic sporulating bacilli yield an alcohol-soluble, water-insoluble fraction,-tyrothricin,-which is bactericidal for most Gram-positive and Gram-negative microbial species. Two different crystalline products have been separated from tyrothricin. One, which may be called tyrocidine, is bactericidal in vitro for both Gram-positive and Gram-negative species; the other substance, gramicidin, is effective only against Gram-positive microorganisms. In general, tyrocidine behaves like a protoplasmic poison and like other antiseptics, loses much of its activity in the presence of animal tissues. Gramicidin on the contrary exerts a much more subtle physiological effect on the susceptible bacterial cells and, when applied locally at the site of the infection, retains in vivo a striking activity against Gram-positive microorganisms. PMID- 19871102 TI - A VIRUS FROM CASES OF ATYPICAL PNEUMONIA : RELATION TO THE VIRUSES OF MENINGOPNEUMONITIS AND PSITTACOSIS. AB - From the lungs of two fatal cases and from the sputum of two non-fatal cases of atypical bronchopneumonia, a psittacosis-like virus was isolated by direct intranasal inoculation of mice. Intraperitoneal injection of the same human material into mice gave negative results. The virus has a relatively high virulence for mice by intranasal or intra-cerebral inoculation, but does not kill after intraperitoneal inoculation. Its virulence for Java ricebirds is low and it fails to produce a carrier state in mice and birds. Two cases showed an increase in complement-fixing antibodies to the new virus and to psittacosis. The virus is antigenically related to the viruses of meningopneumonitis and psittacosis by complement fixation and by active immunity tests in mice. PMID- 19871103 TI - THE ISOLATION OF AN O SPECIFIC SUBSTANCE FROM GASTRIC JUICE OF SECRETORS AND CARBOHYDRATE-LIKE SUBSTANCES FROM GASTRIC JUICE OF NON-SECRETORS. AB - 1. The isolation of a group specific O substance from the gastric juice of human beings belonging to group O is described. Absorbed normal beef serum constitutes the anti-O reagent. 2. The O specific substance inhibits the agglutination of human red blood cells belonging to group O. The agglutination of A cells by the isoagglutinin anti-A, or B cells by the isoagglutinin anti-B, is not influenced by the O substance. 3. The A and B specific substances isolated from human gastric juices inhibit the agglutination of O cells by absorbed normal beef serum, frequently to about the same extent as does the O substance itself. 4. The carbohydrate fraction isolated from the gastric juice of non-secretors belonging to group B does not inhibit the agglutination of human red blood cells of group B by the isoagglutinin anti-B nor the agglutination of O cells by the anti-O reagent. The significance of these findings for the conception of the nature of the blood groups and their inheritance is discussed. PMID- 19871104 TI - FATAL INFECTION OF IRRADIATED WHITE MICE WITH EUROPEAN TYPHUS BY THE INTRA ABDOMINAL ROUTE. AB - A fatal infection of irradiated white mice with the Breinl strain of European typhus has been established and passed serially for 22 passages by the intra abdominal route. Rickettsiae were abundant and easily demonstrable in the moribund or dead mice. The mortality of irradiated mice infected with passage material (peritoneal washings or blood) was nearly 100 per cent as contrasted to no mortality in the control mice given the same dose of x-ray (450 R) and the same volume of fluid intra-abdominally. (The observation period of control mice was arbitrarily limited to 14 days.) After eighteen passages in irradiated mice no increase in virulence for non-irradiated adult mice was detected. After passage in guinea pigs, the rickettsial infection deriving from the mouse passage material was identical with the Breinl strain as judged by fever, cross immunity tests, and brain lesions in sections. PMID- 19871105 TI - QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : I. A METHOD. AB - 1. A quantitative micro method, conforming to the criteria of analytical chemistry, is proposed for the estimation of complement, or its combining component or components, in milligrams per milliliter instead of in the customary relative and variable volume units. 2. Data are given showing the range of accuracy and reproducibility of the new method. PMID- 19871106 TI - QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : II. THE INTERRELATION OF COMPLEMENT WITH ANTIGEN-ANTIBODY COMPOUNDS AND WITH SENSITIZED RED CELLS. AB - 1. The molecular quantities of hemolysin and complement combining component or components (C'1) involved in hemolysis have been calculated on the basis of new, quantitative, absolute methods of analysis. 2. Molecular combining ratios between antigen, antibody, and C'1 have been established. 3. The data are shown to be in accord with the theory of combination of multivalent antigen with multivalent antibody. 4. The fixation of complement by antigen-antibody combination is qualitatively and quantitatively accounted for on this basis. PMID- 19871107 TI - INHERITANCE IN GUINEA PIGS OF THE SUSCEPTIBILITY TO SKIN SENSITIZATION WITH SIMPLE CHEMICAL COMPOUNDS. AB - It has proved possible to set up lines of guinea pigs of significantly different susceptibilities towards a compound of simple structure, namely 2:4 dinitrochlorobenzene. This provides direct evidence that the type of sensitization under discussion is influenced by heredity. PMID- 19871108 TI - CASEIN DIGESTS PARENTERALLY UTILIZED TO FORM BLOOD PLASMA PROTEIN. AB - When blood plasma proteins are depleted by bleeding with return of the washed red cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a uniform plasma protein production on a basal diet limited in protein. Such dogs are clinically normal but have a lowered resistance to infection and certain intoxications. Casein digests given by vein or subcutaneously to such plasma depleted dogs are effective in promoting abundant new plasma protein production. Casein digest L by vein is equivalent to whole liver of like protein equivalence by mouth. The ratio of new plasma protein production to protein intake is 20 to 25 per cent in both instances. Casein digest L by vein gives the same response in plasma protein output as the same digest by mouth. Protein digest X by vein requires addition of tryptophane and cysteine to be effective in plasma protein production. The added cysteine sulfur is more than 95 per cent retained by the dog. The speed of digest injection has no effect on its utilization, within the range tested. Casein digest L given by vein to non-depleted dogs is less well utilized than in dogs depleted of plasma protein. PMID- 19871109 TI - A SIMPLIFIED PERFUSION APPARATUS FOR THE MAINTENANCE OF LIVING ORGANS IN VITRO. AB - A simplified perfusion apparatus for the maintenance of living organs in vitro is described. PMID- 19871110 TI - NATURE OF NON-PARALYTIC AND TRANSITORY PARALYTIC POLIOMYELITIS IN RHESUS MONKEYS INOCULATED WITH HUMAN VIRUS. AB - 1. The occurrence of non-paralytic poliomyelitis in monkeys inoculated with human or first passage virus was proved by histological examination of the nervous system and by isolation of the virus. 2. The non-paralytic infection was almost invariably associated with the destruction of an appreciable number of nerve cells in the spinal cord, and failure of the process to progress seemed to depend upon an equilibrium between the host and the virus, in which the latter occasionally persisted in an active state since it could produce the typical paralytic disease on passage to other monkeys. 3. While there were no reliable clinical or laboratory criteria, the diagnosis of non-paralytic poliomyelitis was made when the following changes were found in the spinal cord: (a) outfall of neurons confirmed by the presence of the reaction of degeneration in the nerve roots, and (b) foci of glial infiltration and perivascular cuffing in the gray matter. 4. Anterior horn cells showing diffuse chromatolysis and acidophilic, intranuclear inclusions were present 2 days after disappearance of paralysis of short duration, and nerve cells with marginated Nissl substance and eccentric nuclei were found side by side with obviously older lesions in monkeys with non paralytic poliomyelitis. These cytologic changes were not present in monkeys sacrificed in still later stages of the disease. 5. The transitory character of the paralysis in some monkeys may depend in part on the fact that apparently normal function can be carried on with less than the normal number of nerve cells and in part on the probable, but not proved, possibility that not all nerve cells attacked by poliomyelitis virus are irreversibly damaged. PMID- 19871111 TI - THE NATURAL HISTORY OF HUMAN POLIOMYELITIS : I. DISTRIBUTION OF VIRUS IN NERVOUS AND NON-NERVOUS TISSUES. AB - 1. Studies on a large number of tissues obtained from fatal cases of human poliomyelitis have revealed that the virus is distributed predominantly in two systems: (a) certain regions of the nervous system, and (b) the alimentary tract. 2. Poliomyelitis virus was demonstrated in the walls of the pharynx, ileum, and only once in those of the descending colon, while the contents of the descending colon regularly contained the virus. 3. The presence of virus in the walls of the alimentary tract appears to be the result neither of generalized dissemination of the virus nor of secondary centrifugal spread, but rather that of primary localization or portal of entry. 4. In the absence of evidence of any demonstrable centrifugal spread to peripheral collections of nerve cells (e.g., in the superior cervical sympathetic ganglia, suprarenals, salivary glands), the presence of virus in the abdominal sympathetic plexus of one case may be indicative of at least one pathway of centripetal virus progression. 5. The absence of demonstrable virus in the nasal mucosa, olfactory bulbs, and anterior perforated substance suggests that neither the upper respiratory tract nor the olfactory pathway were affected in the cases of human poliomyelitis studied in the present investigation. PMID- 19871112 TI - HISTOLOGICAL CHANGES FOLLOWING OVARIECTOMY IN MICE : I. dba HIGH TUMOR STRAIN. AB - 1. In dba mice ovariectomized at birth the vagina, uterus, and mammary glands showed a gradual recovery from the castrate state, and finally reached the stage which they presumably can attain only under the influence of estrogenic hormones. Tumors of the mammary glands developed in 37 animals, of 75 examined, between the ages of 14 and 28 months (3 adenomas and 34 carcinomas). 2. As ovarian regeneration had not taken place the probability that estrogen originated in some other organ in the absence of the ovaries is suggested. 3. The consistent nodular hyperplasia of the suprarenal cortex and close morphological similarity of cells of these nodules to lutein-like cells of the ovaries points to the abnormal suprarenals as possible sources of the estrogenic hormones. PMID- 19871113 TI - A METHOD TO DETERMINE THE PERIPHERAL ARTERIAL BLOOD PRESSURE IN THE MOUSE. AB - Advantage has been taken of the relative transparency of the claw of the mouse to devise a method, here described, to measure the blood pressure in the animal's leg. Direct measurements of the systolic blood pressure from the carotid arteries of anesthetized mice have also been made. Simultaneous blood pressure readings by both these methods applied to the same animal showed close agreement. The systolic pressure ranged from 60 to 126 mm. Hg, according to the conditions. PMID- 19871114 TI - THE SWINE LUNGWORM AS A RESERVOIR AND INTERMEDIATE HOST FOR SWINE INFLUENZA VIRUS : I. THE PRESENCE OF SWINE INFLUENZA VIRUS IN HEALTHY AND SUSCEPTIBLE PIGS. AB - Multiple intramuscular injections of H. influenzae suis were found to precipitate swine influenza virus infections in a group of apparently normal swine. The most likely explanation of the phenomenon seemed to be that the animals, though healthy and susceptible, harbored the virus in some unknown manner. The factors possibly determining the phenomenon were explored experimentally but without success. PMID- 19871115 TI - THE SWINE LUNGWORM AS A RESERVOIR AND INTERMEDIATE HOST FOR SWINE INFLUENZA VIRUS : II. THE TRANSMISSION OF SWINE INFLUENZA VIRUS BY THE SWINE LUNGWORM. AB - 1. The swine lungworm can serve as intermediate host in transmitting swine influenza virus to swine. The virus is present in a masked non-infective form in the lungworm, however, and, to induce infection, must be rendered active by the application of a provocative stimulus to the swine it infests. Multiple intramuscular injections of H. influenzae suis furnish a means of provoking infection. Swine influenza infections can be provoked in properly prepared swine during the autumn, winter, and spring, but not during the summer. The phenomenon, while not regularly reproducible, occurs in well over half the experiments conducted outside the refractory period of summer. No explanation for the failures is apparent. 2. The virus can persist in its lungworm intermediate host for at least 2 years. 3. Swine infected with swine influenza virus by way of the lungworm intermediate host exhibit a more pronounced pneumonia of the posterior lobes of the lung than do animals infected intranasally with virus. The situation of the worms providing the virus will account for this. 4. Occasional swine infested with lungworms carrying influenza virus fail to become clinically ill after provocation but instead become immune. In these it is believed that lungworms containing the virus are localized outside the respiratory tract at the time of provocation. 5. It is believed that the experiments described furnish an explanation for the findings recorded in the preceding paper, in which swine influenza virus infections were induced in apparently normal swine by multiple injections of H. influenzae suis. 6. In a single experiment swine lungworms failed to transmit hog cholera virus. PMID- 19871116 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : IV. DEMONSTRATION OF COPPER IN THE PURIFIED VIRUS. AB - A search by means of spectroscopic and enzymatic techniques has failed to demonstrate either cytochrome or cytochrome oxidase in purified elementary bodies of vaccinia. A constituent of the virus which catalyzes the oxidation of cystein has been found and identified as copper in a concentration amounting to 0.05 per cent of the dry weight of the virus. The copper constituent was not removed by repeated washing, ultrafiltration, dialysis against 0.1 molar potassium cyanide, or by electrodialysis over a pH range which did not inactivate the virus. During the process of purification of the virus a 25-fold increase of the copper constituent was observed. Emission spectra obtained from the dry virus also revealed copper but no significant traces of other metallic substances. No biological role can yet be ascribed to the copper component of virus. PMID- 19871117 TI - THE EFFECT OF THE VIRUS: HOST CELL RELATIONSHIP ON INFECTION WITH VACCINIA. AB - Experiments are described in which it is shown that, in addition to the amount of virus injected, the chance of a lesion also depends on the tissue mass (number of cells) exposed to the virus shortly after injection, and that the larger the number of host cells per virus particle the greater the probability of a lesion. This point has been shown by three types of experiments: (1) varying the size of the inoculum showed that the smaller sizes were relatively more effective than the larger ones; (2) localizing the virus by the estrogenic hormone decreased the chance of a lesion occurring; (3) spreading the virus over a larger area increased the probability of a lesion. It is also shown that because the ratio of virus particles to host cells varies and because this ratio partly determines whether a lesion occurs, the number of particles of virus cannot be predicted by the use of the Poisson law of small numbers. PMID- 19871118 TI - AN INQUIRY INTO THE STRUCTURAL CONDITIONS AFFECTING FLUID TRANSPORT IN THE INTERSTITIAL TISSUE OF THE SKIN. AB - With the aim of determining the structural conditions which affect fluid movement in the cutaneous connective tissue of mice, various test fluids were brought into contact with it under conditions such that neither blood vessels nor lymphatics were directly entered. Locke's solution, mouse serum, and a mixture of Locke's solution with a dye which causes edema were all employed. At atmospheric pressure, Locke's solution entered the tissues intermittently. When subjected to very low pressures it continued to enter the skin intermittently and at approximately the same rate. At pressures above 4.5 cm. of water, however, the flow became continuous but it did not increase in rate significantly until pressures of about 8.5 cm. were employed. There was no relationship between the rate of flow and the pressure employed. At a pressure of about 8.5 cm. the resistance of the tissues seemed to give way abruptly as if the formed elements had been separated. This has been termed the "breaking point." After it had been reached each further increase of pressure produced a proportionately greater inflow. Under the conditions of our experiments, the dye-Locke"s solution and also the homologous serum failed to enter the tissues at atmospheric pressure. It was necessary to subject these fluids to pressure to force them into the skin at the same rate at which the Locke's solution entered it spontaneously. Under these circumstances the dye-Locke's solution and the serum entered the skin continuously, not intermittently like the plain Locke's solution. As the pressure was gradually raised, no significant increase of flow into the tissues occurred until a point was reached, on the average 8.5 cm. of water, at which fluid suddenly began to enter very rapidly. This point, the "breaking point" already mentioned, was reached at the same pressure irrespective of the character of the fluid employed, showing that the phenomenon was produced by the fluid bulk. Once it had been attained, further increases in pressure caused proportionately greater inflow of fluid. The circulation had nothing to do with the phenomenon, for it occurred in the skin of dead mice." The findings indicate that under normal circumstances the movement of fluid in the interstitial tissue does not take place as though in preexisting channels. The experiments confirm previous observations from this laboratory (13, 14) that in normal skin tissue the state of affairs is such that fluid cannot flow freely. However, when fluid is introduced into the skin under pressure spaces are forcibly opened up. Inflammatory edema in the skin changed the phenomena of fluid entrance into it under pressure. The reason is that there then occurred a separation of the formed elements and the interstitial fluid moved as in preformed channels. Even when very low pressures were employed (3.0 to 7.0 cm. of water), there appeared usually a linear relationship between the pressure and the rate of flow. PMID- 19871119 TI - THE CARDIAC FACTOR IN THE "PRESSOR" EFFECTS OF RENIN AND ANGIOTONIN. AB - Upon the isolated hearts of cats perfused with Ringer-Locke solution renin produced no significant effect. Angiotonin, on the other hand, brought about decrease in coronary flow and increase in amplitude of beat without any consistent effect upon heart rate. Both renin and angiotonin augmented the cardiac output and raised the "arterial" pressure in the Starling heart-lung preparation; here too without influence on the heart rate. Electrocardiograms recorded before, during and after the pressor effects of renin and angiotonin in the anesthetized cat showed no abnormalities until the blood pressure had risen above 190 mm. Hg when various types of cardiac arrhythmias appeared. These were prevented, or normal rhythm was restored, by cutting the vagus nerves or injecting atropine. It is concluded that the "pressor" effects of renal pressor substances include direct stimulation of the myocardium and augmentation of ventricular beat. Unless these actions lead to excessive decrease in diastolic volume of the ventricles, the cardiac output will be increased. The significance of this in the production of the pressor effect is discussed. PMID- 19871120 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : VI. THE AGGLUTININ CONTENT OF ANTISERA TO HEMOLYTIC STREPTOCOCCI. AB - 1. Application of the quantitative agglutination procedure to hemolytic streptococci and their antisera is shown to yield values indicative of the antibody content of the antisera in weight units. 2. Estimations are given of type-specific and group-specific antibody in a number of antisera. 3. An incomplete analysis is given of the antigenic components and antibodies involved in the agglutination. 4. Adaptation of the experimental conditions to a simple qualitative type determination of hemolytic streptococci is suggested. PMID- 19871121 TI - INFLUENCE OF AGE ON SUSCEPTIBILITY AND ON IMMUNE RESPONSE OF MICE TO EASTERN EQUINE ENCEPHALOMYELITIS VIRUS. AB - The experiments described in this paper were carried out with the Rockefeller Institute strain of albino mice and with the Eastern strain of the virus of equine encephalomyelitis. 1. The observation was confirmed that with increasing age of mice there occurred a decrease in susceptibility to intraperitoneal injection of active virus; also, the length of incubation period of those which succumbed increased with age. 2. The mice of various age groups which survived an intraperitoneal injection of active virus were indistinguishable in their antibody response. 3. Young mice, vaccinated with formalin-inactivated. virus when 2, 5, and 7 days old, gave an immune response to such a degree that they showed (a) measurable peritoneal immunity which increased with small increments of age, (b) no cerebral resistance, and (c) detectable amounts of neutralizing antibody in their sera which paralleled, though at a considerably lower level, their peritoneal resistance. 4. The peritoneal resistance induced as a result of vaccination was shown to be not local, but a general, systemic immunity, specific for the Eastern strain. Such a peritoneal resistance was demonstrable by the 4th day after beginning of vaccination of 10-days-old mice. 5. After intraperitoneal injection of active virus, large amounts of virus were recoverable from the blood of non-vaccinated young mice; none was found in the blood of vaccinated young mice; a minimal amount was detectable in the blood of non-vaccinated adult mice. 6. The bearing of age on the degree of immune response of which mice are capable and on their susceptibility to the virus has been discussed. PMID- 19871122 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : V. A FLAVIN ASSOCIATED WITH THE PURIFIED VIRUS. AB - Suspensions of purified elementary bodies of vaccinia exhibit fluorescence in the presence of ultraviolet light. This fluorescent constituent can be separated by chromatographic methods provided the virus is first denatured by acid and heat. By means of the specific protein of d-amino acid oxidase it has been possible to identify the flavin constituent as flavin-adenine-dinucleotide and show that it can participate in the oxidative deamination of d-alanine. By means of microbiological assay the flavin component has been quantitatively measured and shown to compare favorably in concentration with that observed in animal cells and in some bacteria; its concentration in virus is lower than that observed in yeast. The demonstration that it exists as an integral portion of the virus is not conclusive. So far, however, it has been separated from the elementary bodies only by means which in themselves inactivate the virus. PMID- 19871124 TI - THE CAPACITY OF THE RENAL VASCULAR BED IN HYPERTENSION. AB - By using kerosene and avoiding postmortem rigor one can obtain perfusion rates in kidneys nearly five times faster than those reported by observers who perfused kidneys immediately post mortem with saline solution, only half as viscous as kerosene. The results obtained by kerosene perfusion indicate possible renal blood flow 50 to 100 per cent greater than that measured by Smith and his coworkers (7) in living men by diodrast clearance under normal conditions, and about as high as those observed in febrile subjects. Like the diodrast method, kerosene perfusion shows a striking decrease in renal vascular bed between early matuity (age 18 to 35) and senescence (45 to 60). This decrease is about 25 per cent. Most kidneys from patients with hypertension without uremia have vascular beds in the normal range, but a few show great decreases in capacity for blood flow. This evidence is interpreted as another indication that renal arteriosclerosis is often a result, rarely a cause of hypertension. Significant occlusion of large renal arteries is rare. Uremia due to amyloid may occur with no significant decrease in renal vascular bed, but the uremia of renal sclerosis, glomerulo- or pyelonephritis is associated with reduction of vascular bed to very low levels. PMID- 19871123 TI - SECOND ATTACKS OF POLIOMYELITIS : AN EXPERIMENTAL STUDY. AB - 1. It was found in forty rhesus monkeys that intracerebral, intraocular, intracutaneous, intraperitoneal, intraspinal, and neural inoculations of poliomyelitis virus produced no lesions in the olfactory bulbs despite the fact that the animals contracted pronounced paralyses. This indicated that the virus could be restricted to certain neuronal systems. 2. Similarly intranasal inoculation of seven animals produced no lesions in the ciliary ganglia. 3. Two monkeys convalescent from an intracutaneous and an intracerebral inoculation respectively had further paralyses after intranasal inoculation of heterologous virus. A third animal convalescent from an intranasal inoculation showed extension of lesions after intranasal and intraocular inoculation with heterologous virus. 4. Two spinal animals in which an attack of poliomyelitis was limited to an isolated segment of spinal cord, contracted typical paralyses in the previously uninvaded portions of the CNS following intranasal inoculation of homologous virus. 5. Four of six convalescent monkeys showed extension of lesions but no clinical signs after homologous virus inoculation through a previously un invaded portal. 6. Four animals convalescent from a unilateral intranasal inoculation showed evidence of new invasion in the opposite olfactory bulb but no extension of paralyses following a second inoculation of homologous virus into the appropriate nostril. 7. Two animals had second attacks after heterologous second inoculations. The intranasal portal was employed for both exposures. 8. It thus seems apparent that in the rhesus monkey a second attack of poliomyelitis, whether paralytic or not, seems to depend upon the strains of virus used and the degree to which virus is disseminated through the neuraxis during the first exposure. 9. The above experimental data emphasize the difficulty of utilizing the rhesus monkey for experiments seeking to elucidate the mechanisms of immunity in man and suggest that human immunity to poliomyelitis does not result from immunization of the nervous system but rather is the result of some process which prevents infective quantities of active virus from reaching nervous tissue. PMID- 19871125 TI - THE CAPACITY OF THE CORONARY BED IN CARDIAC HYPERTROPHY. AB - After eliminating vascular rigor, perfusing human hearts with kerosene under pressure postmortem gives values for coronary flow which seem an index of the maximum possible flow during life. This is 3.1 cc. per gm. per minute at 100 mm. Hg in normal men under 40. It is 35 per cent lower in the hearts of those 60 to 80 years old, and also falls in hypertrophied hearts. In old people it is 30 per cent lower in hearts over 600 gm. than in those under 350; in patients 40 to 60 years old it is 37 per cent less in hearts over 600 as compared with those under 350 gm. In discussion it is brought out that while the decrease in coronary capacity associated with age or hypertrophy may play a part in predisposing some hearts to congestive failure, there is no evidence that the hypertrophied heart has an inadequate oxygen supply or that its fibers are too thick for adequate oxygen diffusion. Congestive failure cannot be ascribed to anoxia except in the presence of severe anemia, coronary occlusion, or tachycardia with low blood pressure. Decrease in perfusibility with age and growth may be a perfectly normal adaptation to the needs of the tissue; the perfusibility of the heart of the young adult is about half that of an infant at 2 years. PMID- 19871126 TI - MYOHEMOGLOBINURIA : A STUDY OF THE RENAL CLEARANCE OF MYOHEMOGLOBIN IN DOGS. AB - When myohemoglobin is injected intravenously into dogs, in amounts ranging from 0.75 to 1.50 gm., it is rapidly eliminated from the plasma and approximately 65 per cent is excreted by the kidneys in from 1(1/2) to 2(1/2) hours. Myohemoglobin does not appear in the urine below a threshold plasma concentration which is slightly under 20 mg. per 100 cc. but above this level the rate of renal excretion is directly proportional to the plasma concentration. The maximum myohemoglobin/creatinine clearance ratio averages 0.58 contrasted with a value of 0.023 for blood hemoglobin. This indicates that the rate of renal clearance of myohemoglobin is twenty-five times more rapid than that of blood hemoglobin. Evidence is presented that the excretory mechanism is essentially similar for the two substances but that differences in molecular weight account for different rates of glomerular filtration. PMID- 19871127 TI - THE TUBULAR FACTOR IN RENAL HEMOGLOBIN EXCRETION. AB - A drop has been observed in the renal threshold for hemoglobin in dogs, of over 60 per cent, following repeated injections daily. It was not associated with a cessation of tubular reabsorption. Hemoglobin excretion rate curves, obtained initially and after lowering the threshold, have proved to be parallel lines originating at the respective levels. Hemoglobin containing radio-active iron has been used to determine the amount of iron retained by the kidneys 24 hours after injection. The kidneys of normal animals retain slightly less iron than those of animals with lowered thresholds, despite the fact that the former group has a much higher estimated rate of tubular reabsorption. It is suggested that hemoglobin products are more rapidly removed from the kidneys of normal animals, following reabsorption, than from those of animals which have received multiple injections of hemoglobin. PMID- 19871128 TI - THE BEHAVIOR OF POX VIRUSES IN THE RESPIRATORY TRACT : IV. THE NASAL INSTILLATION OF FOWL POX VIRUS IN CHICKENS AND IN MICE. AB - Fowl pox virus from active skin lesions was established in the upper respiratory tract of normal chickens by nasal instillation and maintained for 12 successive passages. The nasal infection was not communicable by direct contact but did afford protection, for at least 6 weeks, against subsequent development of the virus in the skin. Multiplication of the virus in the nasal passages was only irregularly attended by specific mucosal changes and was not accompanied by the vigorous counter-reaction engendered by the causal agents of roup. The same strain of virus on propagation in embryonated eggs also survived and multiplied in the nasal tract but with somewhat reduced activity, the 34th egg transfer failing to afford complete protection. Nasal instillation in mice was followed only by a reaction in the lung from which the virus was recoverable through the 7th day. PMID- 19871129 TI - OBSERVATIONS ON THE INFECTION OF CHICK EMBRYOS WITH BACTERIUM TULARENSE, BRUCELLA, AND PASTEURELLA PESTIS. AB - 1. Comparison of the infections of chick embryos by the chorio-allantoic route indicates that Bacterium tularense and Brucella suis, abortus, and melitensis exhibit varying degrees of facultative intracellular parasitism. Pasteurella pestis is adapted to rapid proliferation and spread in the intercellular fluids. 2. In the early stages of infection Bacterium tularense has a marked affinity for growth within ectodermal epithelial cells. Brucella suis and Brucella abortus differ in their selectivity for cells of mesodermal derivation and especially in their effect on vascular endothelium. The strain of Brucella melitensis studied is limited in its intracellular growth to ectodermal epithelium. 3. Many of the features characteristic of these infections in the natural hosts are reproduced in the chick embryo and its membranes. 4. The possible implications regarding the differences in behavior of these microorganisms in relation to the problem of infection and pathogenesis of these diseases are discussed. PMID- 19871130 TI - THE ROENTGEN RADIATION OF PAPILLOMA VIRUS (SHOPE) : II. THE EFFECT OF X-RAYS UPON PAPILLOMA VIRUS IN VITRO. AB - Cell-free suspensions of papilloma virus (Shope) required for their inactivation in vitro amounts of Roentgen irradiation that are much greater than those needed to inactivate other infectious agents previously described. These amounts, millions of r units, are several thousand times greater than those required to eradicate permanently papillomas induced by the virus in domestic rabbits. Large doses of Roentgen radiation reduce the titer of papilloma virus, lengthen the period of time between inoculation and the appearance of papillomas, and decrease the size attained by the papillomas. PMID- 19871131 TI - RENAL HYPERTENSION PRODUCED BY AN AMINO ACID. AB - Acute renal hypertension is produced by the injection of the amino acid dopa (l dihydroxyphenylalanine) into the partially or completely ischemic kidney of the cat. Evidence is presented suggesting that the rise in blood pressure following the injection of dopa is caused by its conversion into hydroxytyramine, a pressor amine. Kidneys with normal blood flow fail to transform dopa into a pressor substance. PMID- 19871132 TI - IMMUNOLOGICAL SPECIFICITY OF MATERIAL SEDIMENTABLE AT HIGH SPEED PRESENT IN NORMAL AND TUMOR TISSUES. AB - Materials sedimentable at high speed (approximately 27,000 R.P.M.) were found in all normal and neoplastic tissues studied. They are carriers of the Forssman antigen and of the Wassermann hapten. These heavy materials exhibit species, organ, and individual specificity and produce several antibodies which can be demonstrated by absorption tests. Heavy materials from chicken sarcoma and chicken spleen could not be distinguished by complement fixation tests. PMID- 19871133 TI - NEUTRALIZATION OF THE AGENT CAUSING LEUKOSIS AND SARCOMA OF FOWLS BY RABBIT ANTISERA. AB - Neutralizing antibodies against fowl tumor agents can be produced in rabbits by injection of heavy materials obtained from chicken tumor. Similar sediments from normal chicken spleen produce no neutralizing antibodies. The complement-fixing antibodies produced by both materials are unrelated to the neutralizing antibodies. PMID- 19871134 TI - FURTHER STUDIES OF THE INFECTIOUS UNIT OF VACCINIA. AB - A study has been made of the comparative virulence of several strains of vaccine virus for a number of hosts, and wide variation in animal susceptibility has been demonstrated. The results obtained in experiments with a chick-embryo-adapted strain are interpreted as indicating that the particles of virus are of essentially uniform virulence. Results of statistical analyses are presented which indicate that as the virulence of a strain of virus increases the number of elementary bodies per infectious unit approaches 1, and at that limit the chance of infection is governed primarily by the presence or absence of virus in the inoculum. With lower virulence the chance of a lesion following inoculation of virus is still described by the binomial theorem, but the actual distribution is primarily of susceptible cells not of viral particles. It is postulated that with regard to the proportion of cells available for parasitism, differences exist between different animals of a species, and that this distribution is of a normal character. PMID- 19871135 TI - ENDOCRINE FUNCTION OF THE SURGICALLY REDUCED PANCREAS. AB - The pancreas reduced to 4 or 10 gm. weeks or months previously by partial resection, is able to maintain a normal glycemic level in dogs of about 10 kilos in good condition. When the pancreas is reduced to 4 gm. the capacity for secreting insulin under certain conditions of strain is diminished whereas a pancreas reduced to 10 gm. may have a normal or decreased capacity. This decreased functional capacity is shown: (1) by a longer hyperglycemic curve after the intravenous injection of 1 gm. of glucose per kilo; (2) by the requirement of smaller doses of extract of anterior hypophysis to produce diabetes; and (3) by the longer time required to correct the diabetic hyperglycemia if reduced pancreas is grafted in the neck of pancreatectomized animals. The time to recover is in inverse ratio to the weight of the transplanted pancreatic tissue. PMID- 19871136 TI - THE PREPARATION AND PHYSICOCHEMICAL CHARACTERIZATION OF THE SERUM PROTEIN COMPONENTS OF COMPLEMENT. AB - 1. Methods for the separation from guinea pig serum in highly purified form of three of the components of complement are described. These substances are the so called mid-piece, end-piece, and 4th component. 2. Mid-piece has been separated as a euglobulin, with an electrophoretic mobility of 2.9 x 10(-5) in phosphate buffer of ionic strength 0.2 at pH 7.7, and with a sedimentation constant of 6.4 x 10(-13) in potassium chloride of ionic strength 0.2. 3. End-piece and 4th component were found together in a euglobulin fraction of serum which contained 10.3 per cent carbohydrate and had an electrophoretic mobility of 4.2 x 10(-5) in phosphate buffer of ionic strength 0.2 at pH 7.7. PMID- 19871137 TI - STUDIES ON AN AGGLUTINOGEN (Rh) IN HUMAN BLOOD REACTING WITH ANTI-RHESUS SERA AND WITH HUMAN ISOANTIBODIES. AB - Studies are reported on an individual agglutinogen (Rh) in human blood which has been found to be of clinical importance because occasionally it gives rise to the formation of immune isoantibodies in man, a peculiarity which leads to untoward transfusion reactions. A method for the determination of the presence or absence of the new blood factor is described, which can be used for typing patients and prospective blood donors. Examination of families showed that the agglutinogen is inherited as a simple Mendelian dominant. The distribution of the factor Rh among white individuals and negroes may indicate racial differences. The property is probably genetically independent of the blood groups and the factors M and N. PMID- 19871138 TI - THE DETECTION OF A "MASKED" VIRUS (THE SHOPE PAPILLOMA VIRUS) BY MEANS OF IMMUNIZATION : RESULTS OF IMMUNIZATION WITH MIXTURES CONTAINING VIRUS AND ANTIBODY. AB - A study has been made of the immunization procedure described by Shope, with particular reference to the detection of "masked" papilloma virus by means of it. Papilloma extracts were frequently encountered which, though non-pathogenic, elicited the specific antiviral antibody and induced resistance to the virus upon injection intraperitoneally into normal rabbits. The results of the immunization experiments were often complicated, however, by the effects of extravasated antibody, which had accumulated in various amounts in many of the papillomas and was consequently present in extracts of them together with "masked" virus. The extravasated antibody was often sufficient to render extracts of domestic rabbit papillomas non-antigenic; and sometimes, when present in excess, its passive transfer conferred resistance to reinfection with the virus. The conclusion seems warranted that only positive immunization findings can be interpreted with certainty. Negative results provide no decisive evidence as to whether "masked" virus is or is not present in the injected material, unless the amount of extravasated antibody also present is known. The findings may have a bearing on the negative outcome of immunization experiments with extracts of the cancers deriving from the natural papillomas of cottontails. Crude suspensions of domestic rabbit papillomas, which contain little or no virus demonstrable by ordinary methods, are far less antigenic than extracts of the natural growths of wild rabbits, which contain virus in quantity. In explanation of the finding the possibility seems worthy of attention that domestic rabbit papillomas may contain much less virus than the growths of cotton tails, the natural hosts of the virus. PMID- 19871139 TI - EXPERIMENTAL NEPHRITIS IN RATS INDUCED BY INJECTION OF ANTIKIDNEY SERUM : V. CHRONIC NEPHRITIS OF INSIDIOUS DEVELOPMENT FOLLOWING APPARENT RECOVERY FROM ACUTE NEPHROTOXIC NEPHRITIS. AB - 1. Three different inbred lines of rats were found to vary in their response to antikidney serum: rats of the Whelan strain were most susceptible to nephrotoxin and most prone to develop chronic glomerulonephritis immediately following the acute injury induced by this agent; animals of the Evans strain were almost as vulnerable to the acute effects of nephrotoxin; Wistar rats were the least affected. 2. Both Evans and Wistar rats usually recovered quickly from the acute injury, and between the 2nd and 5th months after injection they excreted normal or only slightly abnormal urines. During this period of absence of clinical signs of disease, histopathological examination of their kidneys revealed only minor scarring in the glomerular tufts. 3. Most of these apparently recovered rats subsequently developed a slowly progressing chronic glomerulonephritis irrespective of whether they were fed a basal or high protein diet. 4. Histopathologically similar renal lesions were present in all three strains of rats with active chronic nephritis regardless of whether the chronic disease followed immediately the acute nephrotoxic injury or was separated from it by an interval of months. These lesions were somewhat more severe, however, in Whelan rats. 5. Some intraglomerular scarring was present in the kidneys of all rats which survived acute nephrotoxic nephritis. It was especially prominent in those animals that remained clinically cured for as long as a year. 6. The permanent clinical recovery of certain animals, which were found to have moderate glomerular fibrosis on postmortem examination, suggests that factors other than this residual scarring contributed to the development of the recurrent nephritis observed in most of the Evans and Wistar rats. These unknown factors may produce varying degrees of renal functional trauma affecting both glomeruli and tubules. PMID- 19871140 TI - QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : III. UPTAKE OF COMPLEMENT NITROGEN UNDER VARYING EXPERIMENTAL CONDITIONS. AB - 1. Quantitative data are given on the effect of variations in the time of contact and the proportions of the reactants on the quantity of complement combining component nitrogen (C'1 N) found in active guinea pig serum. 2. C'1 N was the same when determined with precipitates containing excess antibody or excess antigen. 3. Finely divided specific precipitates took up the complement combining component (C'1) from subsequently added guinea pig serum almost as well as specific precipitates formed in the presence of complement. PMID- 19871141 TI - INFLUENCE OF CHARACTER OF ANTIBODY UPON VELOCITY OF FLOCCULATION. AB - Results of a thorough study of the rates of flocculation of 20 antisera when mixed with their antigens in all proportions are presented. The relation between the alpha (constant antibody) and beta (constant antigen) optima is discussed. It is suggested that most of the antisera examined can be classified into two main types, one of which, the H type, gives an optimum by both the alpha and beta procedures, whereas the R type gives an optimum only by the former technique. It appears that these differences can only be accounted for by the influence of differences in the physical and chemical properties of the various antibodies. PMID- 19871142 TI - EXPERIMENTAL GONOCOCCUS INFECTION OF THE CHICK EMBRYO. AB - 1. The reaction of the chick embryo to nine strains of gonococci was studied. Four of these were inoculated intra-amniotically in 14 to 15 day embryos. 2. Infection of the 10 day chorio-allantoic membrane was localized and accompanied by polymorphonuclear leucocytic phagocytosis. 3. Infection was either transitory or persisted until hatching. Several strains killed the 10 day embryo in 3 days. 4. Chicken immune sera placed on the infected membranes failed to affect phagocytosis. 5. Slight sinusitis, bronchitis, and infection of the pulmonary alveoli were common following intra-amniotic injection of 14 to 15 day embryos. Infection also extended to the pulmonary and abdominal air sacs. 6. Serial passage on the membrane so modified one strain that it killed a greater percentage of both 10 day and 14 day embryos. The infection after modification was also accompanied by bacteremia and meningitis in one embryo. 7. The ability of meningococci to invade tissue and produce septicemia is contrasted with the inability of gonococci to produce more than a superficial infection. 8. The infection of the embryo with gonococci reproduces all of the essential characteristics of the disease in man. 9. Gonococci were found within columnar epithelial cells in a case of acute human urethritis. PMID- 19871143 TI - TRANSPLANTABLE EPITHELIOMAS OF THE LIP AND MOUTH OF CATFISH : I. PATHOLOGY. TRANSPLANTATION TO ANTERIOR CHAMBER OF EYE AND INTO CORNEA. AB - The catfish (Ameiurus nebulosus) taken from streams near Philadelphia, is commonly afflicted with an epithelial tumor bearing some resemblance to epithelioma of the lip in man. This neoplasm usually occurs as solitary or multiple, large, red, fleshy masses upon the lips or dental plates, and by reason of its size, may prevent closure of the mouth. The tumor is comprised of epithelial cells, often in papillary arrangement, supported by a delicate vascularized connective tissue stroma. The larger growths frequently invade adjacent normal tissues and force their way into vessels where they are found as emboli. The clinical course of the tumor is one of relatively slow but progressive growth. This neoplasm has been observed from the time of its inception in a number of animals. Thus it has been learned that the proliferative stage of the neoplastic process is preceded and accompanied by a striking vascular reaction. Intense hyperemia invariably occurs in that region of the mucosal surface which later becomes the site of neoplastic proliferation. Furthermore, by direct microscopic observation of the living tumors the atypical structure and arrangement of the blood vessels become apparent. A study of the significance of these vascular phenomena in their relation to the inception and growth of the tumor is now in progress. It has been found possible to transmit the catfish tumor to fish of the same species by implanting fragments of the tumor into the anterior chamber of the eye. Also, by taking advantage of an anatomical peculiarity of the catfish cornea, it has been possible to embed the tumor fragments in normal tissue where it could still be readily observed both in the gross and microscopically. The growth of the transplants in the eye has been followed by periodic examination of the living tumor by means of the slit lamp microscope. In the anterior chamber, the tumor characteristically forms dense membranes which spread over the inner surface of the cornea. In this manner growth continues until the tumor fills the chamber. Between the two layers of the cornea, tumor growth is expansive. Attempts to transplant the tumor to the anterior chamber of two other species of fish and to frogs, were unsuccessful. Implantation of the catfish epithelioma in alien species of fish excited no exudative response, whereas in a less closely related species of animal, the leopard frog, a pronounced exudative reaction resulted. PMID- 19871144 TI - THE COMPLEMENT FIXATION TEST IN THE DIAGNOSIS OF VIRUS INFECTIONS OF THE CENTRAL NERVOUS SYSTEM. AB - A specific complement fixation test can be obtained in various central nervous system virus infections by using as antigens emulsions of infected brain tissue, freezing and thawing the brain emulsion, and then centrifuging it in an angle head centrifuge at 3500 R.P.M. for 1 hour. The method has proved reliable in the case of rabies, St. Louis encephalitis, Japanese B encephalitis, lymphocytic choriomeningitis, Eastern equine encephalomyelitis, Western equine encephalomyelitis, louping ill, and spontaneous encephalomyelitis of mice (Theiler's disease). The specificity of the reaction, regardless of the virus involved, requires different temperatures of inactivation of the sera according to animal species: 56 degrees C. for guinea pig, 60 degrees C. for mouse, and 65 degrees C. for rabbit and dog sera, all heated for 20 minutes. For human sera a temperature of inactivation of 60 degrees C. also for 20 minutes has been adopted; at this temperature the reaction is in general specific. Complement fixing antibodies in high titre were found in the sera of rabbits, guinea pigs, mice, and dogs immunized with rabies virus. Complement-fixing antibodies were present in high titre in sera drawn from two persons 8 years after an attack of louping ill, from five persons 2(1/2) years after an attack of Eastern equine encephalomyelitis, and from two persons 2(1/2) years after Western equine encephalomyelitis. In cases of St. Louis encephalitis and lymphocytic choriomeningitis, complement-fixing antibodies have been found shortly following infection but not after long periods. PMID- 19871145 TI - CULTIVATION OF THE HOG CHOLERA VIRUS. AB - The work of Hecke on the cultivation, of hog cholera virus was confirmed with ease. Virus was grown in the presence of fresh minced swine testicle in flasks containing Tyrode solution, on the chorioallantoic membrane of embryonated eggs, and on the surface of swine serum agar. In flasks it was grown for 14 transfers; while on eggs it was grown for 13 transfers, followed by an equal number of transfers on agar, making 26 transfers in all. Only one strain of virus was used and we do not know whether all strains can be cultivated so readily or whether we were particularly fortunate in the selection of the strain used. Neither do we know whether swine testicle is better than other tissues for growth. The cultured virus produces characteristic hog cholera when injected into swine, and its effect can be neutralized with commercial anti-hog cholera serum. No evidence of attenuation of the virus was obtained, the last culture being highly virulent when small amounts were injected. No evidence for the adaptation to the egg could be secured, since passages without swine testicle on the membrane or intravenously for 2 transfers resulted in a loss of the virus. No contaminating virus that might favor the cultivation could be detected by animal or egg inoculation. Not only has the virus been cultivated but it has been demonstrated in large amounts in the culture. Four suspensions containing slightly over 0.5 mg. of protein nitrogen produced typical hog cholera when 1 x 10(-6) cc. was injected, and one suspension made in the same way was active in one-tenth this amount. Few titrations on what is commonly known as hog cholera virus, i.e. the serum from acutely ill pigs, are available. We made one such titration and produced a delayed disease with 1 x 10(-5) cc. of infectious serum. It seems probable that the culture virus is more active than the commonly used virus and that its practical use in hog cholera vaccination and hyperimmunization would result in a considerable saving. All of the methods used yielded active cultures, but the serum agar method is the one of choice since larger amounts of suspension can be obtained with less labor. PMID- 19871146 TI - NEUTRALIZING ANTIBODIES IN HUMAN SERUM AFTER INFLUENZA A : THE LACK OF STRAIN SPECIFICITY IN THE IMMUNOLOGICAL RESPONSE. AB - The increased concentrations of neutralizing antibodies against influenza A virus in human serum which occur after influenza A do not differentiate between antigenically different strains of this virus or swine influenza virus but instead appear to possess equal reactivity against these agents. The decrease in antibody levels which occurs with time is also independent of the strain of virus used to measure it. PMID- 19871147 TI - STUDIES ON CONDITIONS AFFECTING THE SURVIVAL IN VITRO OF A MALARIAL PARASITE (PLASMODIUM LOPHURAE). AB - The survival of Plasmodium lophurae in vitro, at temperatures of 39.5-42 degrees C., is favored by a balanced salt solution having a high potassium content, by aeration but not by a very high oxygen tension, by an optimal density of parasites per cubic millimeter, by frequent renewal of the suspending medium, by concentrated red cell extract, by optimal concentrations of plasma or serum, of chick embryo extract, of glucose or glycogen, and of glutathione, and probably by yeast extract and a very low concentration of liver extract. In the best preparations, as judged by infectivity, more than 40 per cent of the parasites were alive on the 3rd day, more than 20 per cent on the 4th day, perhaps 1 per cent on the 5th day, and about 0.05 per cent on the 6th day. Evidence was obtained that the parasites had multiplied during the 1st day of incubation. PMID- 19871148 TI - INFLUENCE OF EXTRANEOUS PROTEIN AND VIRUS CONCENTRATION ON THE INACTIVATION OF THE RABBIT PAPILLOMA VIRUS BY X-RAYS. AB - The pronounced resistance to the x-rays manifested by the papilloma virus in ordinary suspensions is due to the protecting influence of extraneous matter and also in considerable degree to the amount of virus present in the preparation. Two to 4 million r were required to inactivate the virus contained in the crude papilloma extracts prepared for the present work, whereas 100,000 r or less was enough to inactivate comparable concentrations of virus after extraneous matter had been excluded by repeated differential centrifugation. The addition of normal rabbit serum or crystalline egg albumin to purified suspensions of virus was found to increase greatly the amount of irradiation required to inactivate the virus. Furthermore the percentage destruction of virus by a given amount of irradiation increases as the concentration is decreased by dilution with saline or buffer solutions. As little as 3,000 r will inactivate much of the virus in very dilute suspensions. The complement-binding antigen of papilloma virus suspensions is also inactivated by x-rays, but requires a somewhat larger amount of irradiation than necessary to destroy the infectivity of the suspensions. The effects of irradiation on the antiviral antibody present in the blood of animals which have become immune to the virus-an antibody that specifically fixes complement in mixture with the papilloma virus-are also conditioned by extraneous material. 250,000 to 500,000 r had only a slight effect on the antibody in whole serum, while this amount of irradiation completely inactivated comparable amounts of antibody in preparations partially purified by precipitation with ammonium sulfate. As a whole the findings indicate that under certain conditions of purity and concentration most of the radiation does not act by direct hits on virus or antibody particles, but indirectly by ionizing or exciting some other molecules present in the exposed suspension, which then react with the virus or antibody molecules. PMID- 19871149 TI - COMPARATIVE VIRULENCE OF ST. LOUIS ENCEPHALITIS VIRUS CULTURED WITH BRAIN TISSUE FROM INNATELY SUSCEPTIBLE AND INNATELY RESISTANT MICE. AB - We find that St. Louis encephalitis virus cultured in 10 per cent serum-Tyrode solution plus brain tissue from 1-day-old innately susceptible mice attains a higher titre than when cultured in a similar solution plus brain tissue from 1 day-old closely related, yet innately resistant mice. This difference in titre persists regardless of whether the serum comes from innately susceptible or resistant mice. The relatively high titre of virus in the susceptible media is not affected by the addition of an extract (not cell-free) from the resistant brain; the relatively low titre of the virus in the resistant media may possibly be slightly enhanced by the addition of an extract from the susceptible brain. The findings as a whole show that the marked difference in the increase of St. Louis encephalitis virus in the brain tissue of innately susceptible and resistant mice, on culture in vitro, is due to some difference in the brain tissue itself. PMID- 19871150 TI - THE SEROLOGICAL SPECIFICITY OF PARTICULATE COMPONENTS DERIVED FROM VARIOUS NORMAL MAMMALIAN ORGANS. AB - 1. Particles derived from filtrates of organ suspensions by high speed centrifugation were serologically active as shown by agglutination and complement fixation techniques. Particles from brain, liver, lung, kidney, heart muscle, spleen, testicle, and pancreas of various species have been studied. 2. All particles showed a certain degree of organ specificity with the exception of pancreas. Cross-reactions occurred between the particles from various organs from one species, which were more marked when complement fixation technique was employed than by the agglutination test. However, agglutination always appeared earlier and was stronger, and complement fixation was positive in higher dilutions of antigen in the presence of homologous antiserum than with heterologous antisera. 3. The cross-reactions did not depend on the occasional precipitins for serum and the agglutinins for the red cells of the species from which the particles were derived, nor did they bear a relation to Wassermann and Forssman antibodies present in some of the sera. 4. The organ specific differentiation of the particles from various organs could more clearly be demonstrated by two means: The antiserum could be diluted in such a way that only the homologous reaction still showed a positive result while the cross-reactions had become negative; or the cross-reacting antibodies could be absorbed by heterologous particles and the homologous reaction was still more or less intact. 5. In addition to the organ specific differentiation, most particles were found to exhibit species specificity. While the particles derived from kidney, lung, testicle, and heart muscle aggregated only in the presence of the antiserum against the corresponding organ particles from the homologous species, brain particles reacted with brain antisera against both homologous and heterologous species alike. Absorption of brain particle antisera with brain preparations from a heterologous species removed all antibodies. Liver particle preparations showed an intermediate position in that all liver preparations with the exception of rabbit liver particles were aggregated by any liver particle antiserum. However, absorption with liver particles from a heterologous species left a distinct species specific reaction in the serum. 6. The antigens involved are all destroyed by heating to 100 degrees C. for a few minutes with the exception of brain particles, which after 20 minutes at 100 degrees C. still gave complement fixation almost to the same strength as the untreated controls. 7. Alcoholic and ether extracts of brain reacted with the brain particle antisera only. All alcoholic or ether extracts of other organs gave no complement fixation. None of the various other organ particle antisera tested contained antibodies for these extracts. 8. The relationship between the heat-stable and the alcohol-soluble brain particle antigen studied by absorption technique revealed that there were two antigens present, both organ specific and independent of the species, the one alcohol- and ether-soluble, the other not soluble in these solvents but heat stable. Some of the sera showed besides a few species specific antibodies. 9. Preliminary evidence has been gathered to show that no iso-immunization could be obtained with any one of the organ particles. As far as cytotoxic activity of the sera is concerned only the kidney particle antisera have been studied for nephrotoxins; these failed to reveal any such activity in the mouse. PMID- 19871151 TI - STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES : LXIV. ANTIGENICITY OF DEXTRAN PRODUCED BY LEUCONOSTOC MESENTEROIDES. AB - Anti-Leuconostoc mesenteroides sera have been produced in rabbits. These antisera gave precipitin reactions with relatively high dilutions of the homologous polysaccharide, dextran, having a maximum nitrogen content of 0.08 per cent. It can therefore be concluded that this dextran is a haptene. PMID- 19871152 TI - THE NATURAL HISTORY OF HUMAN POLIOMYELITIS : II. ELIMINATION OF THE VIRUS. AB - Studies on the elimination of virus in human paralytic poliomyelitis during the first 2 weeks of the disease, revealed the following:- 1. The nasal (not nasopharyngeal) secretions collected from 22 patients on cotton plugs over a period of 3 days and the saliva and oral secretions expectorated during a similar period by 20 patients failed to yield virus. 2. In 10 of the patients whose secretions (nasal, oral, or both) were investigated, virus was isolated from single specimens of the lower intestinal contents. 3. No virus was found in large amounts of urine (up to 200 cc.) obtained from 12 patients, 6 of whom had paralysis of the bladder. 4. In the present tests virus was found 4 times more often in the stools of patients under 8 years of age (64 per cent of 11 cases) than in older individuals (17 per cent of 12 cases). This difference was found to obtain when our data were combined with those which could justifiably be selected from the literature, the total figures indicating that virus has been isolated from 50 per cent of 58 children under 8 years of age and from 12 per cent of 60 older individuals. 5. No support was found for the hypothesis that poliomyelitis virus in the stools originates from swallowed nasal secretions and saliva or oral secretions. PMID- 19871153 TI - THE INACTIVATING EFFECT OF SULFAPYRIDINE ON THE LEUKOTOXIC ACTION OF BENZENE. AB - 1. In rabbits receiving subcutaneous injections of benzene, the simultaneous administration of sulfapyridine, per os, prevented the development of leukopenia. The sparing effect of sulfapyridine on the intoxication of the leukopoietic tissue by benzene was demonstrated not only by the range of daily leukocyte counts but also by microscopic examination of the bone marrow of treated animals. 2. The administration of para-aminobenzoic acid failed to inhibit the leukotoxic action of benzene. 3. The administration of sulfapyridine alone to rabbits was followed by daily variation in the number of leukocytes in the circulating blood but persistent leukocytosis was not observed. The inhibiting action of sulfapyridine was not found to be referable to the development of an overcompensating leukocytosis. 4. In preliminary experiments, the excretion of phenols by rabbits receiving sulfapyridine together with benzene differed from that observed in animals receiving benzene alone. In the former group, the rise in the excretion of total phenols was not so high as in the latter group, but the percentage of combined phenols was greater. The possible significance of the findings has been discussed. PMID- 19871154 TI - A QUANTITATIVE STUDY OF THE SCARLET FEVER TOXIN-ANTITOXIN FLOCCULATION REACTION. AB - 1. Highly purified scarlet fever toxin has been prepared from culture filtrates of two scarlatinal strains (NY5 and 594B) of hemolytic streptococcus grown on a medium of defined composition. 2. The flocculation reaction of Rane and Wyman has been studied quantitatively and has been shown specific for scarlet fever toxin and antitoxin. 3. Scarlet fever toxin from strains NY5 and 594B are quantitatively identical in their immunological behavior. 4. Pure scarlet fever toxin contains 0.00023 mg. nitrogen per flocculating unit and close to 1.3 x 10(8) skin test doses per mg. nitrogen as calculated from the immunological data. Both the immunological and the analytical data suggest that scarlet fever toxin is a protein. Similar calculations indicate that scarlet fever antitoxin contains 0.00093 mg. nitrogen per unit. 5. The scarlet fever toxin-antitoxin complex is readily dissociated in dilute solutions. In this respect the scarlet fever toxin antitoxin system contrasts sharply with the diphtheria toxin-antitoxin system. 6. The scarlet fever toxin-antitoxin reaction is discussed in relation to other flocculation reactions. PMID- 19871155 TI - CAPACITY OF PLEUROPNEUMONIA-LIKE MICROORGANISMS TO GROW ON CHORIOALLANTOIC MEMBRANES. AB - 1. Among eight strains or variants, included in four different immunological types of pleuropneumonia-like microorganisms, all grew on chorioallantoic membranes; those belonging to Klieneberger's Type L(5) (Sabin Type A) grew very poorly; and those included in three other types grew with varying degrees of vigor. 2. In all instances, strains of pleuropneumonia-like microorganisms tested grew better on dead sterile chorioallantoic membranes than on living membranes. 3. None of the strains tested was in itself lethal for chick embryos. 4. No constant macroscopic lesion developed as a result of inoculating chorioallantoic membranes with pleuropneumonia-like microorganisms. PMID- 19871156 TI - DETERMINATION OF THE VOLUME OF THE EXTRACELLULAR FLUID OF THE BODY WITH RADIOACTIVE SODIUM. AB - A method for measuring the volume of fluid available for the distribution of sodium (sodium space) by the use of its radioactive isotope (Na(24)) has been described and the accuracy of the method has been discussed. Simultaneous determinations of the plasma volume by means of the blue dye T-1824 and the volume of the extracellular fluid by employing radiosodium and sodium thiocyanate have been made in normal subjects. Repeated measurements were made at varying periods of time in the same individuals. In order to establish the rate of diffusion equilibrium for the radioactive isotope of sodium and thiocyanate between serum and serous effusions, simultaneous samples of both were obtained at varying intervals after the intravenous injection of these substances. Since evidence in the literature indicates that there is an excess of sodium mainly limited to bone, which cannot be attributed to the extracellular phase, experiments on dogs and man were so devised that the ratio of tissue concentration to plasma concentration for radiosodium and chemically determined chloride could be calculated. The following conclusions may be drawn from the results of this investigation: 1. Radiosodium after intravenous administration spreads rapidly during the first 3 hours from the plasma into a volume of fluid which represents approximately 25 per cent of the body weight of man. Thereafter for 6 hours it diffuses more slowly into certain tissue spaces-the central nervous system and probably the skeleton. The plasma volume and interstitial fluid represent 15 and 85 per cent of the sodium space respectively. 2. Diffusion equilibrium for both radiosodium and thiocyanate is not established between serum and transudates in edematous patients until from 9 to 12 hours after the intravenous injection of these substances. 3. Until more complete information is available, it is concluded that unless the difference between repeated observations on the same individual exceeds +/-1.38 liters there is no significant change in the sodium space providing that the activity of the standard and serum samples are in the range of 40 counts per minute per milliliter with the counting apparatus used. As the activity of the samples increases, the error becomes less because there is no correlation between the magnitude of the error and the magnitude of the activity. 4. Climatic conditions produce no significant changes in the volume of the blood or extracellular fluid. 5. In the dog, following the intravenous injection of radiosodium, the concentration of the isotope in bone reaches its maximum rapidly (3 hours). The extra sodium in the skeleton of dog is equal to about (1/4) of the total counts in the body, assuming that the chloride space of bone represents its extracellular volume. Similar amounts of excess sodium are found in the skeleton of man 12 hours after the administration of Na(24). 6. Correction of the sodium space of man for the excess sodium reduced the average value by 3.7 liters or 18.9 per cent. The average corrected volume for the normal subjects 6 hours after the injection is 15.9 liters or 21.1 per cent of the body weight compared with the thiocyanate space of 17.7 liters, representing 23.5 per cent of the body weight. 7. The most useful method for calculating the sodium space from the data obtained after intravenous administration of radiosodium is as follows: See PDF for Equation This space exceeds the volume of extracellular fluid by the amount of excess sodium in the body that cannot be attributed to the extracellular phase. 8. While neither the thiocyanate method nor the radiosodium method gives precise estimates of the extracellular fluid, the error is of the same order of magnitude in both. For clinical use, the thiocyanate method is superior because of the ready availability of the substance, and the apparatus required. PMID- 19871157 TI - THE EFFECT OF HIGH PROTEIN DIETS ON EXPERIMENTAL RENAL HYPERTENSION. AB - The effect of high and low protein diets were studied on fourteen dogs in twenty four different experiments. In only two of these animals, both with moderate renal excretory failure, was a reversible rise in blood pressure elicited by a high protein diet. The possible mechanisms involved in meeting an increased excretory load are discussed. PMID- 19871158 TI - OCCURRENCE OF POLIOMYELITIS VIRUS IN AUTOPSIES, PATIENTS, AND CONTACTS. AB - 1. Poliomyelitis virus has been recovered in monkeys from 50 per cent of spinal cords, 10 per cent of olfactory bulbs, 50 per cent of tonsil-adenoid tissue, and from 26 per cent of the colon contents of autopsies; from the stools of 20 per cent of patients, and of 5 per cent of the contacts examined in this series. 2. Other materials as indicated in Table I were tested without success. 3. In autopsies with positive cords, tonsil-adenoid tissues, or colon contents were positive in 73 per cent. 4. 22 per cent of stools from patients with paralysis yielded virus and 19 per cent of the stools from patients without paralysis yielded virus. 5. 20 per cent of the stools from males and 22 per cent of the stools from females yielded virus. 6. 40 per cent of 35 stools from patients under 16 years yielded virus while 8 per cent of 38 stools from patients above the age of 15 yielded virus. 7. 71 per cent of the cords of 35 autopsies under 16 years yielded virus while 31 per cent 16 years and over yielded virus. 8. Repeat stools from 5 positive cases, 1 month after the first positive stool, were negative. The stool of one contact was positive the 2nd month after first recovery but was negative the 3rd month. PMID- 19871159 TI - THE BACTERICIDAL ACTION OF SYNTHETIC DETERGENTS. AB - 1. The bactericidal action of a number of anionic and cationic synthetic detergents on four Gram-positive and three Gram-negative bacteria has been investigated. 2. Cationic detergents, as a group, were found to exhibit marked bactericidal effects on Gram-positive microorganisms and somewhat less pronounced action on Gram-negative organisms. 3. The anionic detergents were germicidal only against the Gram-positive organisms, and they were considerably less effective than the cationic compounds. Of the anionic detergents, the most active one was an alkyl sulfate derived from a branched-chain, secondary alcohol. 4. Correlations between bactericidal action and inhibition of bacterial metabolism, and also between bactericidal action and chemical structure of the detergents are discussed. PMID- 19871160 TI - INHIBITION BY PHOSPHOLIPIDS OF THE ACTION OF SYNTHETIC DETERGENTS ON BACTERIA. AB - 1. Lecithin, cephalin, and sphingomyelin prevent the inhibition of bacterial metabolism which is caused by synthetic anionic and cationic detergents. The phospholipids must be added either before or simultaneously with the detergent. Addition after the detergent is without effect. Bacteria still exhibit this phenomenon after they have been exposed to the phospholipid and thoroughly washed. 2. A similar action of the phospholipids has been demonstrated towards the bactericidal compounds isolated by Dubos and Hoogerheide from soil bacteria. There is very little effect with bactericidal mercury compounds. 3. The effect of lecithin against the bactericidal action of synthetic detergents was also determined. It was found that germicidal quantities of the detergents were not effective in the presence of the phospholipids. PMID- 19871161 TI - PERIODIC EXAMINATION OF SEWAGE FOR THE VIRUS OF POLIOMYELITIS. AB - From a series of tests covering 15 months, another instance is recorded of the detection of the virus of poliomyelitis in urban sewage. It has not yet been possible to detect the virus of poliomyelitis in sewage during non-epidemic periods. It is likely that the periodic sampling of sewage for pathogenic viruses or bacteria may be a method of epidemiological value. PMID- 19871162 TI - THE NATURAL HISTORY OF EXPERIMENTAL POLIOMYELITIS INFECTION : I. STUDIES ON THE CENTRIFUGAL SPREAD AND ELIMINATION OF VIRUS IN INTRASCIATICALLY INOCULATED RHESUS MONKEYS. AB - 1. Eight rhesus monkeys with experimental poliomyelitis following intrasciatic inoculation of "M.V." virus were used to study the extent of virus spread in the central and peripheral nervous systems and the question of its elimination in the nasal secretions. 2. Tests on nasal secretions collected on absorbent cotton plugs daily and continuously from the moment of inoculation to the end of the disease failed to reveal virus. 3. No virus was found in the olfactory bulbs, nasal mucosa, tonsils and adjacent pharyngeal tissue, salivary glands, adrenals, superior cervical sympathetic ganglia, abdominal celiac ganglia, and small intestine. 4. Elimination of virus by the nasal route was not one of the consequences of poliomyelitis infection resulting from invasion of the "M.V." virus by way of a peripheral nerve in rhesus monkeys. 5. No indiscriminate widespread dissemination of virus occurred in the central nervous system of the intraneurally inoculated rhesus monkeys nor did the virus spread outward sufficiently to involve the collateral sympathetic ganglia or the collections of nerve cells in various peripheral tissues. Under certain circumstances, therefore, the presence of virus in these ganglia and tissues may be used as an index to the portal of entry of the virus. PMID- 19871163 TI - A COMPARISON OF ERYTHROCYTE SEDIMENTATION RATES AND ELECTROPHORETIC PATTERNS OF NORMAL AND PATHOLOGICAL HUMAN BLOOD. AB - Electrophoretic studies and erythrocyte sedimentation rate measurements were carried out on normal and pathological human blood. An increase in alpha globulin levels appears to take place, as well as an increase in sedimentation rates, when there is present any considerable inflammation or tissue destruction, irrespective of its cause. A graphic correlation is presented between sedimentation rates and alpha globulin levels, which is at least as good as a similar correlation involving fibrinogen levels. PMID- 19871164 TI - STUDIES CONCERNING THE SITE OF RENIN FORMATION IN THE KIDNEY : I. THE ABSENCE OF RENIN IN THE AGLOMERULAR KIDNEY OF THE MIDSHIPMAN FISH. AB - 1. The absence of glomeruli in the kidney of the midshipman fish (Porichthys notatus) is reported. 2. The detection of renin in the glomerular kidney of the carp, the catfish, and the hog, and the apparent absence of this substance in the aglomerular kidney of the midshipman fish suggest that the tubular portion of the mammalian kidney does not produce or store renin. PMID- 19871165 TI - THE ANTIGENIC RELATIONSHIP OF THE VIRUSES OF MENINGOPNEUMONITIS AND LYMPHOGRANULOMA VENEREUM. AB - Animals recovered from infection with the viruses of lymphogranuloma venereum, meningopneumonitis, and psittacosis, were reinoculated in crossimmunity tests with these viruses. In mice immunized by intracerebral or intranasal inoculation a reciprocal partial cross-immunity between the viruses of lymphogranuloma venereum and meningopneumonitis was demonstrated. In preliminary experiments, similar cross-immunity between the agents of lymphogranuloma venereum and psittacosis was not definitely demonstrated. Hamsters, white rats, and kangaroo rats recovered from intracerebral or intranasal infection with the virus of lymphogranuloma venereum were more resistant than normal controls to inoculation with the virus of meningopneumonitis. Sera of animals immunized with the viruses of lymphogranuloma venereum and meningopneumonitis showed cross-reactions by complement fixation with antigens of these viruses. The results indicate an antigenic relationship between the viruses of lymphogranuloma venereum and meningopneumonitis. PMID- 19871166 TI - A FURTHER STUDY OF THE CROSS REACTION BETWEEN THE SPECIFIC POLYSACCHARIDES OF TYPES III AND VIII PNEUMOCOCCI IN HORSE ANTISERA. AB - 1. The cross reaction of the specific polysaccharide of Type VIII pneumococcus with Type III antipneumococcus horse serum has been studied quantitatively and found similar to the S III-anti-S VIII reaction. 2. Contrasted with the general similarity of the two-segment reaction curves were distinct qualitative and quantitative differences in the course and character of the reciprocal reactions with respect to each segment. 3. These differences could be interpreted in terms of the known chemical differences between the specific polysaccharides of the two types. A minimum molecular weight of 62,000 was calculated for S III and 140,000 for S VIII. 4. It was also found possible to fractionate the Type VIII antibody into portions characteristic of each segment of the cross reaction curve. At least three different kinds of Type III and Type VIII anticarbohydrates were identified. PMID- 19871167 TI - THE QUANTITATIVE DETERMINATION OF INFLUENZA VIRUS AND ANTIBODIES BY MEANS OF RED CELL AGGLUTINATION. AB - 1. The agglutination titer for chicken red cells of freshly prepared or carefully stored suspensions of PR8 influenza virus, that is to say virus of maximum pathogenicity, was found to be proportional to the mouse lethal titer of the same preparations. 2. The agglutination titer of infected allantoic fluid procured in a standard way is relatively constant, regardless of the influenza strain used and its pathogenicity for mice. 3. Virus preparations inactivated by heat or storage may retain their agglutinating power. 4. Certain animal sera contain a partially heat-labile factor which, in low dilution, inhibits the agglutination of chicken red cells by influenza A and influenza B viruses. 5. The agglutination inhibition test, using ferret and human sera, gives qualitative data regarding influenza antibodies which are similar to the information obtained on the same sera by means of the virus neutralization test. 6. There is a definite relationship between the agglutination inhibition titer and the virus neutralization titer of a serum. On a logarithmic scale of both variables, this relationship is essentially linear within the range investigated. 7. The agglutination inhibition titer of immune ferret serum is inversely proportional to the amount of virus used in the test. PMID- 19871168 TI - DEMONSTRATION OF AGGLUTININS FOR BARTONELLA BACILLIFORMIS. AB - 1. Methods of preparing a satisfactory antigen having been developed, a technique for performing an agglutination test with B. bacilliformis is made available. 2. As a result of repeated intravenous injection of living cultures of B. bacilliformis at short intervals, rabbits have been found to produce a high titre of specific agglutinins which, under the conditions obtaining in the present series of experiments, begins to decline after about one month following the last inoculation. 3. Sera from six cases of bartonellosis in different stages of its several manifestations have been shown by the agglutination test to contain a low but definite titre of circulating antibody. 4. Several of these same sera have been shown to contain as well a significantly high titre of agglutinins for three strains of Proteus. No definite conclusions can be drawn from this phenomenon since the case histories had not been probed for the possibility of typhus fever; and since the relatively high titres obtained with a few of the present sera may very well fall within the extremes of normal serum titres. PMID- 19871169 TI - THE ENDURING PARTNERSHIP OF A NEOPLASTIC VIRUS AND CARCINOMA CELLS : CONTINUED INCREASE OF VIRUS IN THE V2 CARCINOMA DURING PROPAGATION IN VIRUS-IMMUNE HOSTS. AB - The V2 carcinoma-a transplanted rabbit cancer derived originally from a virus induced papilloma and carrying in masked or altered form the virus primarily responsible for it-was propagated in five successive groups of animals all previously hyperimmunized against the papilloma virus. The cancer grew as well in the hyperimmunized hosts as in normal animals implanted during the same months; and serological tests, made when the tumor was eventually returned to ordinary hosts, proved that the virus was still associated with the carcinoma cells: it had increased to the usual extent as the tumor grew in the hyperimmune animals. The continued increase of the neoplastic virus during propagation of the V2 carcinoma in hyperimmunized hosts contrasts sharply with the elimination of certain extraneous passenger viruses when the tumors they ride upon are grown in hosts previously immunized against them. The facts as a whole would seem to warrant a distinction between the enduring partnership of a neoplastic virus and carcinoma cells on the one hand and the casual association of passenger viruses with tumor cells on the other. PMID- 19871170 TI - THE EFFECT OF SULFAPYRIDINE UPON THE DEVELOPMENT OF IMMUNITY TO PNEUMOCOCCUS IN RABBITS. AB - 1. Sulfapyridine, administered to rabbits during the period of developing immunity after a single intravenous injection of heat-killed Pneumococcus Type I, exerted no influence upon the immune response. 2. Active immunity as indicated by increased resistance to homologous intradermal infection was present 48 hours after the immunizing injection and 2 days before circulating type specific antibodies were detectable. 3. Of the serological techniques employed for the detection of circulating antibody the mouse protective test yielded the highest percentage of positive results followed in order by tests for type specific agglutinins and precipitins, the latter being least satisfactory for the detection of small amounts of antibody. PMID- 19871171 TI - COMPARATIVE DIABETOGENIC ACTION OF THE HYPOPHYSIS FROM VARIOUS ANIMALS. AB - Of all the anterior hypophyses tested, those of the human produced the most marked diabetogenic action in the dog with its pancreatic tissue reduced to 4 gm., and in the hypophysectomized and pancreatectomized toad. The human hypophysis also produced diabetogenic action in the normal dog on daily doses of 1.26 mg. per kilo per day for 2 days. The hypophysectomized dog with its pancreas reduced to 4 gm. is very sensitive to the anterior hypophyseal diabetogenic action and is the best test animal for demonstrating such action in mammals. The anterior hypophysis of man, toad, rat, and chicken produces in such animals a diabetogenic action with doses of from 10 to 15 mg. per kilo per day. The bovine anterior hypophysis has identical action in 20 mg. doses. That of canine origin was much less active in a few though inconclusive experiments. It was impossible to demonstrate a diabetogenic action with either guinea pig hypophysis or with that of fish probably because insufficient doses were injected. The diabetogenic action was not obtained by the injection of other organ extracts of toads, dogs and oxen, of corticosterone (30, 40, and 60 mg. in 4 days) or of desoxycorticosterone (80 mg. and 200 mg. in 4 days). The toad (Bufo arenarum Hensel), deprived of its hypophysis and pancreas is the most sensitive biological reactor for testing the diabetogenic action. In this animal the diabetogenic action of anterior hypophyses from varied sources decreased in the following order: man, dog, toad (Bufo arenarum Hensel), white rat, guinea pig, chicken (whole hypophysis), ox, serpent (Constrictor constrictor (L.)), the fish "corvina" Micropogon opercularis (Quoy and Gaimard, 1824), and "merluza" Merlucius hubbsi (Marini, 1933). PMID- 19871172 TI - QUANTITATIVE EXPERIMENTS WITH ANTIBODIES TO A SPECIFIC PRECIPITATE : III. ANTIGENIC PROPERTIES OF HORSE SERUM FRACTIONS ISOLATED BY ELECTROPHORESIS AND BY ULTRACENTRIFUGATION. AB - 1. Rabbit antisera to a Type II pneumococcus specific precipitate from horse serum were tested with fractions prepared by ultracentrifugation and electrophoresis of normal and immune horse serum. 2. In one instance a rapidly sedimenting protein from normal horse serum had nearly the same quantitative antigenic properties toward the anti-antibody rabbit serum as did the purified pneumococcus antibody solutions previously reported. In another instance a comparable fraction removed only a part of the rabbit antibody. 3. Electrophoretic gamma-globulin from an immune horse serum had quantitatively the same antigenic properties as did antibody solutions prepared by salt-dissociation of specific precipitates. 4. Electrophoretic gamma-globulin from normal horse serum differed in its antigenic behavior from gamma-globulin containing antibody. The data are compared with the antigenic properties of acid and alkali treated pneumococcus specific polysaccharides toward antipneumococcus horse sera. An interpretation in terms of polymers is suggested. 5. The cross-reaction of goat serum gamma-globulin against the anti-antibody serum is reported and the extent of the reaction compared with those of goat and horse serum albumins against a rabbit antiserum to the latter. PMID- 19871173 TI - THE LS-ANTIGEN OF VACCINIA : I. INHIBITION OF L- AND S-ANTIBODIES BY SUBSTANCES IN TREATED VACCINE DERMAL FILTRATE. AB - Experimental data are presented which may be interpreted as follows. The heat labile (L) and heat-stable (S) antigens of vaccinia occur in nature as a complex consisting of a single substance with two serologically active parts, each of which may be degraded independently of the other. PMID- 19871174 TI - THE LS-ANTIGEN OF VACCINIA : II. ISOLATION OF A SINGLE SUBSTANCE CONTAINING BOTH L- AND S-ACTIVITY. AB - Virus-free filtrate, obtained from suspensions of vaccine virus-infected dermal pulp of rabbits and rich in the soluble substances of vaccinia, was shown to contain four distinct components in electrophoresis experiments. Electrophoretic and serological observations served as a guide in developing a method for separating these components from one another. This method depended upon changes in the solubilities of the components with alterations of pH. Three of the four components appeared to be serologically inert when tested with anti-vaccinia sera. All of the L- and S-activity was found to be associated with a single component which was electrically homogeneous at several values of pH and which was homogeneous in the ultracentrifuge. This single substance, designated as LS antigen, precipitates in equal titers with optimal amounts of L- and of S antibody and is completely removed from solution by absorption with either antibody. The LS-antigen of vaccinia appears to be a protein molecule with two antigenically distinct parts, L and S. Heating modifies the L-portion in such a manner that the substance no longer precipitates with L-antibody; this degraded antigen still combines with L-antibody, as is shown by inhibition tests, and still precipitates with S-antibody. Similarly, treatment with heat and dilute alkali modifies the S-portion of LS-antigen so that it combines but does not precipitate with S-antibody; and at the same time all recognizable immunological properties of the L-portion are destroyed. PMID- 19871175 TI - THE EFFECT OF VARIOUS DIETS ON THE LIVER DAMAGE CAUSED BY EXCESS CYSTINE. AB - 1. The effect of 9 different diets on the liver lesions resulting from excess dietary cystine has been studied in 130 rats. 2. The incidence and severity of each of the following liver lesions were varied by changes in the composition of diets containing 5 or 10 per cent cystine: (a) Hemorrhage was least severe with low fat diets. (b) Necrosis was most severe with synthetic diets. (c) Cirrhosis was delayed by a diet high in lard, 20 per cent, and cod liver oil, 5 per cent, but not by a diet high in butter, 25 per cent. (d) Fatty infiltration was found consistently only with low protein, high fat diets. In other words, the pathogenesis of the liver lesion due to excess dietary cystine can be modified by diet. 3. In the presence of cystine as 5 per cent of a low protein, high fat diet, 1 per cent choline inhibited fatty infiltration but did not protect the liver against damage by cystine. 4. In these experiments there was no apparent correlation between fatty infiltration of the liver and the incidence or degree of cirrhosis. PMID- 19871176 TI - LIVER DAMAGE AND URINARY EXCRETION OF SULFATE IN RATS FED l-CYSTINE, dl METHIONINE, AND CYSTEIC ACID. AB - 1. Rats fed l-cystine at excessive levels excrete large amounts of sulfate sulfur in the urine and develop liver necrosis and cirrhosis. 2. Rats fed dl-methionine at excessive levels excrete large amounts of sulfate sulfur, but do not develop liver necrosis and cirrhosis. 3. Rats fed cysteic acid at high levels excrete relatively small amounts of sulfate, but do develop liver necrosis and cirrhosis. 4. In conclusion, there is no apparent correlation between the amount of sulfate formed and the development of liver damage in rats fed l-cystine, dl-methionine, and cysteic acids. PMID- 19871177 TI - CELL STATE AS AFFECTING SUSCEPTIBILITY TO A VIRUS : ENHANCED EFFECTIVENESS OF THE RABBIT PAPILLOMA VIRUS ON HYPERPLASTIC EPIDERMIS. AB - Rabbit skin can be rendered abnormally susceptible to papilloma virus infection by preliminary treatments with a variety of agents. The most effective agents thus far found are 0.3 per cent methylcholanthrene in benzene and a mixture in equal parts of turpentine and acetone, applied four or five times at 2 day intervals. When virus is inoculated into skin altered by these agents, either intradermally or by inunction after scarification, papillomas appear earlier and in greater number than on normal skin, and much higher dilutions give rise to growths. The method provides a means of detecting amounts of virus which cause no papillomas upon inoculation into normal skin. Papilloma virus material which is rubbed into scarified normal or hyperplastic skin is largely lost in the scabbing which ensues, and nearly all of it fails to reach susceptible cells. The preparatory agents which increase the effectiveness of the virus bring about marked epidermal hyperplasia, and the hyperplastic tissue regenerates with greater rapidity when scarified. The agents evidently act in large part by providing young epidermal cells in quantity to the virus, as also by inducing a richer vascularization than ordinary in support of the papillomatous proliferation. It is possible that they also act by providing especially susceptible cells. The implications of the findings are discussed. PMID- 19871178 TI - RED CELL AND PLASMA VOLUMES (CIRCULATING AND TOTAL) AS DETERMINED BY RADIO IRON AND BY DYE. AB - 1. Application of the principles of hydrodynamics to the problem of blood flow and blood volume indicates that the calculation of blood volume and cell volume from the venous hematocrit and plasma volume (as determined by the dye method) is subject to considerable error. 2. This conclusion is borne out by determinations of total cell volume by viviperfusion and with the use of radioactive iron tagged erythrocytes, which have shown the erythrocyte volume to be only 70 to 75 per cent of the volume indicated by the previously mentioned calculations. 3. The average hematocrit of the entire vascular system is considerably lower than the hematocrit of the large vessels, and the cell-plasma ratio of the smaller vessels is still less. 4. In the dog there are no considerable stores of immobilized erythrocytes, and the total erythrocyte volume and circulating erythrocyte volume are identical. 5. The "rapidly circulating blood volume" can be determined by dividing the erythrocyte volume by the venous hematocrit, and is found to be considerably less than the total blood volume. 6. The concept of the "rapidly circulating plasma volume" is introduced, and it is found to be approximately 80 per cent of the total plasma volume. 7. The volume of plasma in the peripheral, cell free, sluggishly moving plasma films, plus that contained in small vessels in which no red cells are present, is also determined and found to be approximately 20 per cent of the entire plasma volume. 8. The existence and magnitude of these fractions of the blood plasma volume should receive consideration in studies of blood flow and blood volume. PMID- 19871179 TI - INFLUENCE OF AGE ON SUSCEPTIBILITY OF MICE TO ST. LOUIS ENCEPHALITIS VIRUS AND ON THE DISTRIBUTION OF LESIONS. AB - 1. Young mice are more susceptible than older mice to the virus of St. Louis encephalitis inoculated intraperitoneally, but with virus inoculated intracerebrally or intranasally, there is no significant age difference in susceptibility. The greatest change in the resistance to the virus inoculated intraperitoneally occurs between the 2nd and 3rd weeks of life. 2. The distribution of the lesions of St. Louis encephalitis in the C.N.S. of young and of old animals following intraperitoneal inoculation indicates that the virus may reach the brain either by the ascending pathway from the spinal cord or by the olfactory pathway irrespective of the age of the animal. However the ascending pathway is most frequently concerned. 3. The distribution of lesions does not offer evidence that the virus enters the C.N.S. of young animals directly from the blood stream following intraperitoneal inoculation. 4. Although widespread lesions occur earlier in the C.N.S. of young mice than in that of older mice inoculated intraperitoneally with large doses of virus, this fact is not satisfactorily explained by assuming the more rapid increase of the virus in the C.N.S. of young animals, since the latter are not more susceptible to virus inoculated directly into the brain. 5. The observations can be explained by the hypothesis that a greater amount of virus survives and reaches the portals of the C.N.S. in young animals following intraperitoneal inoculation and that this is an important factor in the influence of age on susceptibility to the virus. PMID- 19871180 TI - STUDIES ON THE MECHANISM OF IMMUNITY IN TUBERCULOSIS : THE FATE OF TUBERCLE BACILLI INGESTED BY MONONUCLEAR PHAGOCYTES DERIVED FROM NORMAL AND IMMUNIZED ANIMALS. AB - 1. Mononuclear phagocytes of immunized animals that had ingested tubercle bacilli in vivo and had subsequently been transplanted and grown in the environment of a normal animal continue to inhibit the multiplication of the microorganism in their cytoplasm in the absence of immune body fluids. 2. Mononuclear phagocytes of immunized animals that had ingested tubercle bacilli in vitro in the presence of immune serum inhibit the multiplication of the microorganism in their cytoplasm to a much greater extent than cells of normal animals that had ingested the bacteria in the same medium and had grown in a similar environment. 3. The presence of immune serum during the in vitro ingestion of tubercle bacilli by mononuclear phagocytes of normal animals does not regularly endow them with increased bacteriostatic properties for the microorganism. Whether or not continued sojourn of normal cells in immune body fluids will confer upon them such properties has not been determined. 4. Mononuclear phagocytes of immunized animals that had ingested tubercle bacilli in vitro in a medium of normal serum and had subsequently grown in an environment devoid of immune body fluids inhibit the multiplication of the microorganism in their cytoplasm to a much greater extent than do normal cells under the same conditions. 5. Active tuberculosis confers on the mononuclear phagocytes themselves increased bacteriostatic properties for the tubercle bacillus which are independent of the immune body fluids or of the organ environment in which they grow. PMID- 19871181 TI - SEROLOGICAL REACTIVITY OF HYDROLYTIC PRODUCTS FROM SILK. AB - The foregoing experiments show that products of the hydrolysis of silk that consist of peptides having, from amino nitrogen determinations, molecular weights from about 600 to 1000 were capable of inhibiting the reactions of precipitin sera for silk. From the results it may reasonably be inferred that silk fibroin contains determinant structures not larger than the peptides examined, which probably consist of not more than 8 to 12 amino acids. That similar relations may obtain with other proteins is not improbable in view of results previously reported with dialyzable split products. PMID- 19871182 TI - SYNTHESIS OF INOSITOL IN MICE. AB - It has been shown that mice are able to synthesize inositol. This synthesis was not observed when pantothenic acid was absent from the diet. Cultures from the intestinal tract of animals which exhibited spontaneous cure of alopecia yielded microorganisms which synthesized much more inositol than did organisms isolated in the same fashion from the tracts of mice that had become hairless. Some observations on the distribution of free and combined inositol have been made and it has been shown that several biological materials contain combined inositol. It has been found that deficiency of inositol can develop even when inositol is present in the diet if pantothenic acid is omitted. PMID- 19871183 TI - QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : IV. ADDITION OF HUMAN COMPLEMENT TO SPECIFIC PRECIPITATES. AB - 1. A modified method is given for the titration of human complement so that C'1 titers are measured, as in guinea pig serum, instead of the C'2 titers yielded by the usual titration. 2. The measurement of complement combining component or components in weight units, instead of relative terms, is carried out as in guinea pig serum and leads to similar values, 0.03 to 0.05 mg. of C' N per ml. of human serum. 3. Other similarities in human and guinea pig complements are noted and discussed. PMID- 19871184 TI - THE EFFECT OF UNDERNOURISHMENT ON THE SUSCEPTIBILITY OF THE RABBIT TO INFECTION WITH VACCINIA. AB - Experiments are reported in which it is shown that if rabbits are deprived of food, the lesions resulting from injection of vaccinia are either fewer or smaller; presumably this is partially explainable on reduction of available nutrients in the cell. The number and character of the lesions are also modified by the state of hydration of the interstitial tissues: If the amount of interstitial fluid is increased by permitting the animal to drink water, the lesions are even less numerous; but if the interstitial tissues are dehydrated either by withholding water or by injecting physiological saline solution into the peritoneal cavity, then the lesions are more numerous. The increase in interstitial fluids in these experiments was not due to decreased plasma proteins, for these were normal. In this respect, therefore, the rabbit differs from man, for unless the plasma proteins are reduced, simple starvation in man results in dehydration rather than edema of the tissues. From these experiments it is concluded that the virus is less able to multiply in the poorly nourished cell than in the well nourished one, and that hydration of the tissues increases the resistance of the tissue to infection while dehydration has the opposite effect. It is suggested that this is because hydration tends to localize the virus in situ, with result that fewer cells are exposed to it, while dehydration has the opposite effect. However, actual changes in cell susceptibility consequent upon altered water balance may be responsible for the effect. PMID- 19871185 TI - THE REACTION OF PERIPHERAL BLOOD VESSELS TO ANGIOTONIN, RENIN, AND OTHER PRESSOR AGENTS. AB - 1. Both renin and angiotonin in small doses cause constriction of the arterioles in the ears of normal rabbits, as seen directly with the microscope. Capillaries appear unaffected while venules exhibit slight or no constriction with small doses and moderate constriction with large doses. The flow of blood through the tissues is not reduced except when very large doses are administered. Tyramine and methylguanidine sulfate in isopressor amounts act somewhat similarly. 2. Isopressor amounts of epinephrine and pitressin, by contrast, elicit severe vasoconstriction of arterioles lasting longer than that due to angiotonin, and flow of blood is sharply reduced or abolished altogether. The degree of venular constriction was also greater, while the capillaries remained unaffected. 3. The vasoconstrictor action of angiotonin on peripheral vessels in moat chambers in normal rabbit's ears is indistinguishable from that of renin, except that it is more rapid. PMID- 19871186 TI - HUMAN ALLERGY TO MAMMALIAN SERA. AB - Four patients allergic to many mammalian sera were found to have circulating, skin-sensitizing antibodies for these sera. A study of these antibodies by in vitro neutralization and subsequent local passive transfer showed that, in the case of each patient, one particular mammalian serum neutralized antibodies for all sera whereas other mammalian sera neutralized antibodies for themselves alone or for themselves plus one or several additional sera but not for all sera. The possibility of multiple common allergenic determinants in mammalian sera is discussed. PMID- 19871187 TI - STUDIES ON LYMPHOGRANULOMA VENEREUM : I. DEVELOPMENT OF THE AGENT IN THE YOLK SAC OF THE CHICKEN EMBRYO. AB - Making use of the fact that the cells of the yolk sac of the developing embryo are readily infected with the agent of lymphogranuloma venereum and that the virus bodies can be readily observed in these cells because of the structure of the latter, the development of this agent has been followed at short intervals. It has been found to go through a regular cycle of development similar to that described for psittacosis in the spleen and less fully for lymphogranuloma venereum in the brain of infected mice. The development as observed microscopically can be shown to run parallel to changes in the infective titre of the yolk sac as tested in other eggs. PMID- 19871188 TI - SEROLOGICALLY REACTIVE POLYSACCHARIDES PRODUCED THROUGH THE ACTION OF BACTERIAL ENZYMES : I. DEXTRAN OF LEUCONOSTOC MESENTEROIDES FROM SUCROSE. AB - A serologically reactive polysaccharide of dextran nature was produced from sucrose by the action of some enzyme or similar heat-labile agent contained in sterile filtered extracts derived from sucrose broth cultures of Leuconostoc mesenteroides. Rigorous controls were included to prove that this reaction occurred in the absence of microorganisms. Purified preparations of the dextran formed by the sterile extracts were similar to the dextran elaborated in sucrose broth cultures of the bacteria in respect to both chemical and serological properties. The serological likeness was established not only by tests against leuconostoc antiserums but also by cross reactions with antiserums of Types 2, 20, and 12 pneumococci and by tests against a series of variously absorbed antiserums. PMID- 19871189 TI - OBSERVATIONS ON THE CONDITIONS OF DIETARY HEPATIC INJURY (NECROSIS, CIRRHOSIS) IN RATS. AB - Experimental dietary hepatic injury (diffuse or focal necrosis and cirrhosis in rats, with or without ascites and pleural and pericardial effusion) is determined by the dietary factors instrumental also in the production of fat infiltration of the liver and thus opposed to the lipotropic activity of casein. Accordingly, rats maintained on a diet low in casein with a moderately high or high content of fat and without choline regularly exhibited hepatic injury after between 100 and 150 days. Supplements of l-cystine had an aggravating effect on the production of cirrhosis of the liver, whereas a supplement of choline alone reduced the severity and the incidence of hepatic injury, although not decisively. The combined administration of l-cystine plus choline or of dl-methionine in adequate doses, however, proved to be highly effective in preventing injury to the liver. These conclusions have been corroborated by the use of different modifications of the basal diet. Rats with dietary hepatic injury exhibit, in sequence, changes that vary from diffuse necrosis resembling human acute or subacute yellow atrophy to advanced portal cirrhosis. Diffuse necrotizing nephrosis was a frequent accompaniment of the hepatic injury. Cystine again, proved to be a factor which aggravated this condition. PMID- 19871190 TI - STUDIES ON THE ANTIBACTERIAL ACTION OF THE SULFONAMIDE DRUGS : I. THE RELATION OFp-AMINOBENZOIC ACID TO THE MECHANISM OF BACTERIOSTASIS. AB - The following observations have been made which substantiate the theory that the sulfonamide drugs used in the treatment of bacterial infections exert their bacteriostatic effect by competing with the essential metabolite, p-amino-benzoic acid, for an important enzyme site on the bacterial cell. 1. p-Aminobenzoic acid was shown to nullify the bacteriostatic effect of all of the six sulfonamide compounds studied even though the drugs exhibited marked differences in chemical structure. 2. The bacteriostatic potency of each sulfonamide drug was found to be directly proportional to its ability to counteract the antibacteriostatic action of p-aminobenzoic acid. 3. In the case of each drug tested over a wide range of concentrations the minimum amount of p-aminobenzoic acid needed to prevent bacteriostasis was such that the ratio of p-aminobenzoic acid to drug was constant. 4. The linear relationship between p-aminobenzoic acid and drug was interpreted as indicating the competitive inhibition of an essential enzyme reaction by a substance chemically related to the substrate. This interpretation was supported by the fact that the equation derived on purely theoretical grounds relating drug and acid expressed the same linear relationship as that observed experimentally. PMID- 19871191 TI - STUDIES ON THE ANTIBACTERIAL ACTION OF THE SULFONAMIDE DRUGS : II. THE POSSIBLE RELATION OF DRUG ACTIVITY TO SUBSTANCES OTHER THANp-AMINOBENZOIC ACID. AB - 1. In cultures of Staphylococus aureus in a synthetic medium nicotinamide and cozymase were shown to block the bacteriostatic action of chemically unrelated sulfonamide drugs as well as the chemically related compound sulfapyridine. The antibacterial properties of organic dyes totally unrelated to the sulfonamide compounds (methylene blue and thionine) were also nullified by the addition of cozymase to the culture medium. 2. The antagonistic action of the pyridine containing coenzyme, cozymase, was found, by quantitative study, to be no greater against sulfapyridine than against other structurally dissimilar sulfonamide compounds. 3. The antidrug effects of nicotinamide and cozymase in staphylococcus cultures were observed to be directly proportional to their ability to stimulate the growth of the organism in the synthetic medium. When tested in cultures of B. coli in which they failed to accelerate bacterial growth, these same substances failed to influence the bacteriostatic action of the sulfonamide drugs. 4. The in vitro action of the coenzyme, cocarboxylase, as measured in the Warburg respirometer, was shown to be unaffected by the chemically related drug, sulfathiazole, even when the latter was present in great excess. The above observations fail to support the theory that sulfapyridine, sulfathiazole, and sulfadiazine prevent bacterial growth by interfering with the functioning of the chemically related coenzymes, cozymase, and cocarboxylase. The mode of action of sulfanilamide and its more common derivatives is discussed in the light of these observations, and a tentative theory is offered to explain the differences in bacteriostatic potency exhibited by the various sulfonamide compounds. PMID- 19871192 TI - STUDIES ON THE PURIFICATION OF POLIOMYELITIS VIRUS : I. YIELDS AND ACTIVITY OF PREPARATIONS OBTAINED BY DIFFERENTIAL CENTRIFUGATION. AB - Results of experiments on the preparation of high molecular weight constituents from normal and poliomyelitis-infected medullae-cords are presented. Relatively large yields were obtained from glycerolated normal or infected tissues or from tissues that had been stored at -10 degrees C. for a few days. When the frozen tissues were stored for several weeks, the amount of sedimentable nitrogen isolated from the normal cords decreased and became almost negligible. Under these same conditions small but definite amounts of a high molecular weight material were isolated from the infectious extracts. This material regularly produced poliomyelitis when 1 ml. containing 5 x 10(-9) gm. of nitrogen was injected intracerebrally into rhesus monkeys. The purified virus sediment contains nitrogen, phosphorus, and carbohydrate, it gives the Millon's test for protein, and is precipitated by one-third saturation with ammonium sulfate. Results of ultracentrifugal analyses show that a relatively homogeneous component with S(W) (20 degrees ) = 62 x 10(-13) is present. PMID- 19871193 TI - ON THE MECHANISM OF SPECIFIC PRECIPITATION. AB - A study of the precipitability by the appropriate antisera of 34 different haptens, containing from one to six reactive groups, leads to the conclusion that the possibility of framework ("lattice") formation is neither necessary nor sufficient for specific precipitation, but that instead precipitation depends upon the reduction, by mutual neutralization of polar groups of antibody and antigen (or hapten) and mechanical blocking off of polar groups of closely neighboring molecules of antibody, of the solubility of the complex below the point at which it can remain in solution. The decisive factors appear to be the number of polar groups of the antigen (hapten) left free, and the distance separating the different reactive groups, which determines the amount of steric hindrance exerted by one antibody molecule on another. No hypothesis is offered as to how these primary insoluble aggregates unite with each other to produce the larger aggregates which are finally observed. PMID- 19871194 TI - THE ROLE OF THE COMPONENTS OF COMPLEMENT IN SPECIFIC IMMUNE FIXATION. AB - From the experiments reported here it is evident that the amount of each complement component which combines with specific immune aggregates depends upon a number of factors, including the age of the complement; the concentrations of antigen, antibody, and complement; hydrogen ion and electrolyte concentrations; and time and temperature of incubation for fixation. The experiments also reveal the following: 1. C'4 must be considered a combining component of complement because it is invariably inactivated or adsorbed by specific aggregates. 2. C'3, although necessary for the final action of complement, e.g., hemolysis or bactericidal action, is fixed only partially or not at all by antigen-antibody compounds. 3. C'2 is fixed together with C'4, as is evident from those experiments in which reactivations were conducted with a CO(2)-insoluble fraction which contained no C'4 activity. 4. Mid-piece, which contains C'1, generally stated to be the single combining component of complement, is adsorbed by immune aggregates in varying amounts depending on the experimental conditions employed. 5. No inactivation or adsorption of C'4 and of C'3 occurs upon the addition to specific aggregates of serum which has been heated at 56 degrees C. for 30 to 50 minutes. This indicates that certain thermolabile constituents of serum are necessary for the fixation of C'4. Inactivation of C'4 by hydrazine or the removal of C'3 by the insoluble carbohydrate from yeast does not markedly influence the fixation of the other components. 6. The assumption that the mid piece is the single combining component of complement is further questioned for the following reasons. First, C'4 in fresh, untreated serum combines with specific aggregates, but C'4 in heat-inactivated serum does not. It is, therefore, apparent that a part of the combining complement must be attributed to C'4 and its carrier C'2. Second, it will be shown in a subsequent paper that C'1, heated at 56 degrees C. for 45 minutes, combines with specific immune complexes, and in doing so may in fact inhibit the further combination of the components of untreated complement. This effect, first noted by Ehrlich and Sachs (27), is termed a "complementoid" action. Thirdly, it will also be shown on the basis of quantitative nitrogen data (28), that the combining nitrogen, in those instances in which large amounts of serum are added to a constant amount of aggregate, should for the most part be attributed to C'4 and its carrier C'2. 7. The nature and the molecular size of the antigen does not influence the qualitative picture of fixation of the complement components. 8. While it is tempting to speculate on the mechanism of complement fixation, it probably is advisable that such speculation be postponed until experiments similar to those reported here are performed with purified components. However, certain differences between the fixation of the complement components to specific aggregates and the adsorption of these components to non-specific agents, are apparent. For example, in specific immune fixation C'4, C'2, and varying amounts of C'1 are fixed, while in non-specific adsorption both to inorganic adsorbents (29) and to untreated bacteria (30, 31), no fixation of C'4-C'2 occurs while all of the other components of complement are adsorbed. Furthermore, C'3 is bound only partially or not at all to specific aggregates, while it is completely adsorbed or inactivated by non-specific adsorbents. It appears, therefore, that the highly reactive component, C'4, is directly and immediately involved in specific immune fixation. 9. A very small amount of specific immune aggregate combines with a large amount of complement; whereas a large amount of non-specific agent adsorbs only a small amount of complement. This difference is undoubtedly due to the marked chemical affinity of C'4-C'2 and C'1 for the surfaces presented by immune aggregates. 10. It can be now stated that when complement exerts its activity in hemolytic, bacteriolytic, or bactericidal reactions, C'4-C'2 and varying amounts of C'1 must first combine (fix) with the antigen-antibody compound in question; and that any secondary manifestation is dependent both on the adjunctive action of the unbound C'3 (26) and on the nature of the substrate employed. The chemical and immunological implications of these results will be further elaborated in subsequent papers. PMID- 19871195 TI - STUDIES ON MENINGOCOCCAL INFECTION : XII. IMMUNOCHEMICAL STUDIES ON MENINGOCOCCUS TYPE II. AB - From meningococcus Type II broth autolysates, a substance, corresponding to the protective antibody has been isolated. This substance, termed kappa substance, is firmly connected with protein but can be separated by the action of proteolytic enzymes. Methods of preparation and purification are given, together with chemical and serological data. In whole cells from young cultures, this substance is also connected with protein, especially with one protein fraction which requires highest alkali concentration to effect solution. PMID- 19871196 TI - STUDIES ON HYPOALBUMINEMIA PRODUCED BY PROTEIN-DEFICIENT DIETS : I. HYPOALBUMINEMIA AS A QUANTITATIVE MEASURE OF TISSUE PROTEIN DEPLETION. AB - In five dogs placed on a protein-poor diet for 3 weeks, the decline in total circulating plasma albumin was a small (3 per cent) but relatively constant part of the total nitrogen lost. These data together with observations on dogs by others indicate that there is a constant relationship or partition in the loss (or gain) between plasma albumin and total body protein induced by diet. Based on this relationship a formula is developed for estimating the degree of total tissue protein deficiency from the value of the serum albumin concentration alone. This formula would also apply to the replenishment of protein deficiencies of dietary origin and it indicates that for every gram of increase in serum albumin desired about 30 gm. must be retained for increases in other proteins of the body. PMID- 19871197 TI - STUDIES ON HYPOALBUMINEMIA PRODUCED BY PROTEIN-DEFICIENT DIETS : II. RAPID CORRECTION OF HYPOALBUMINEMIA WITH AN AD LIBITUM MEAT DIET. AB - Serum albumin depletion, induced by a 3 weeks fast, was completely corrected within 1 week by the ingestion of a diet consisting solely of meat administered ad libitum. The average protein intake was 50 gm. per kilo of body weight per day. A 2nd week of the same diet produced no further increase in serum albumin though it did lead to an increase in the globulin fraction. PMID- 19871198 TI - THE LOCALIZED ACTION ON THE SPINAL CORD OF INTRAMUSCULARLY INJECTED TETANUS TOXIN. AB - Local tetanus limited to one leg was studied in cats after intramuscular injection of tetanus toxin. 1. The electric and mechanical response of the affected muscle after a single stimulus to the intact sensory-motor nerve is greater in amplitude and duration than the response of the corresponding muscle of the unaffected leg (Fig. 1). 2. This augmented response of the muscle is associated with an augmented response arising from the ipsilateral portion of the spinal cord, while the contralateral part of the cord is unaffected, as demonstrated by electrographic records from the motor nerves (Figs. 2 to 5). 3. The augmented muscular response is abolished when the reflex arc is broken, but the augmented response in the spinal cord is independent of changes in the muscle, the neuromuscular junction, the afferent and efferent peripheral nerves, and the dorsal root ganglia. 4. The augmented spinal response develops in the absence of the peripheral signs of local tetanus. Hence the pathogenesis of the altered state in the spinal cord is independent of the peripheral effects of the toxin. 5. In local tetanus, therefore, the toxin injected intramuscularly acts selectively upon the segments of the spinal cord which supply the innervation of the injected area. 6. The augmented spinal response may be prevented by section of the nerve trunks supplying the area of injection prior to the injection of the toxin. 7. It is concluded that in local tetanus the toxin is carried to the spinal cord by way of peripheral nerves. PMID- 19871199 TI - COPPER AND COBALT RELATED HEMOGLOBIN PRODUCTION IN EXPERIMENTAL ANEMIA. AB - Copper added to a standard diet often effects a moderate increase in hemoglobin production in anemia due to blood loss. The copper response is quite irregular in contrast to the iron response. In these dogs there is no lack of copper held in reserve stores (liver and spleen) so the reaction is not related to an actual deficiency of the element. An effect upon enzyme complexes related to globin and hemoglobin production is to be considered. Cobalt under similar conditions causes no stimulus to hemoglobin production, rather an inhibitory effect when more than minimal doses are given. The claim that cobalt causes a polycythemia in dogs receives no support from our experiments. PMID- 19871200 TI - RED CELL AND PLASMA RADIOACTIVE COPPER IN NORMAL AND ANEMIC DOGS. AB - Following ingestion of radioactive copper by the dog, the metal appears quickly in the plasma, the concentration reaching its peak in from 2 to 5 hours, after which it falls abruptly. Demonstrable amounts are still present after 2 days. The radioactive copper likewise appears rapidly in the circulating red blood cells, and there is a slow but gradual increase in its concentration over a 2 day period. It is suggested by the data that in the animals in which hematopoietic activity is accelerated the uptake of radio-copper is somewhat more extensive. The possibility that this is due to greater adsorption by the new red cells in these instances is not ruled out. PMID- 19871201 TI - ANTIBODY RESPONSE OF HUMAN BEINGS FOLLOWING VACCINATION WITH INFLUENZA VIRUSES. AB - Eleven different preparations of influenza virus were used to vaccinate large groups of human beings. The antibody response to these vaccines was measured by means of the in vitro agglutination inhibition test, and the geometric mean titers of sera taken 2 weeks after vaccination were compared. From these comparisons the following conclusions were drawn: 1. There was a wide individual variation in the antibody response of human beings to the same preparation of influenza virus administrated subcutaneously. The amount of antibody produced by a group with a low prevaccination antibody level was very nearly the same as the amount produced by groups that had higher initial levels. 2. The use of the X strain of distemper virus in the preparation of an influenza vaccine did not enhance the antigenicity of the influenza virus present. 3. Within certain limits the mean antibody response of human beings increased as the amount of virus injected was increased. When large amounts of influenza A virus were given, the antibody response was of the same order of magnitude as that which occurred following actual infection by this virus. 4. When the vaccine was prepared from allantoic fluid, there was no significant difference in the antibody response of human beings given active virus, formalin-inactivated virus, heat-inactivated virus, or virus inactivated by the drying process. 5. Ground infected chick embryos, when diluted with infected allantoic fluid, gave a greater antibody response than allantoic fluid alone (when the virus remained active). The antigenicity of such a preparation was diminished when the virus was inactivated by formalin. 6. Antibody levels 6 and 9 weeks after vaccination showed a marked drop from the 2-week postvaccination levels. In a small group the antibody levels at 5 months were still further reduced. Those individuals who possessed the higher titers tended to lose their antibodies faster than did those at a lower level. PMID- 19871202 TI - ARTERIAL HYPERTENSION IN RATS : I. METHODS. AB - Normal standards for the blood pressure of rats under pentobarbital sodium anesthesia have been ascertained. Arterial hypertension did not consistently follow the injection of estradiol and pitressin in adult rats, and only transient hypertension occurred after the injection of dihydroxyphenylalanine. The injection of adrenalin in oil, however, was followed by cardiac hypertrophy, and it also resulted from (a) partial constriction of one renal artery, (b) the production of unilateral hydronephrosis, (c) traumatic injury to one kidney, (d) inducing unilateral perinephritis with a cellophane membrane. The blood pressure in many of the animals became elevated. In rats the weight of the heart is probably a more reliable index of the presence of the hypertensive state than is one measurement, or two, of blood pressure under anesthesia. The latter is extremely variable, both in normal and in hypertensive animals. Rats are, however, liable to hypertension under natural circumstances, and it can be easily induced in a number of ways. The weight of the heart may then become rapidly increased. To judge from the findings in this species, rats are very susceptible to the production of the hypertensive state, in comparison with other animals. PMID- 19871203 TI - ARTERIAL HYPERTENSION IN RATS : II. EFFECTS ON THE KIDNEYS. AB - 1. When rats developed cardiac hypertrophy or elevation of blood pressure as a result of one of several methods designed to bring about arterial hypertension, renal vascular disease occurred frequently. 2. When injury to one kidney was followed by cardiac hypertrophy or elevation of blood pressure, vascular lesions were found with considerable regularity in the opposite one, as well as in the one injured. 3. Renal lesions rarely occurred in the absence of cardiac hypertrophy or elevated blood pressure. 4. Renal vascular lesions in rats are occasioned, therefore, by injury to one kidney and are usually associated with, and dependent on, the presence of arterial hypertension. PMID- 19871204 TI - TOXEMIA OF PREGNANCY IN THE GUINEA PIG. AB - The clinical and pathological manifestations of a disease occurring in the late stages of pregnancy or following parturition in the guinea pig are described. The similarity of this disease to toxemia of pregnancy in the rabbit is discussed. The disease appears to be of endogenous origin and is in some way associated with a disordered metabolism occurring at about the time of parturition. PMID- 19871205 TI - THE HYPOPHYSIS AND SECRETION OF INSULIN. AB - The ability of the pancreas, from various types of dogs, to correct diabetic hyperglycemia has been studied (Table XI). The pancreas from one animal was united by a vascular union with the neck blood vessels of another dog which had been pancreatectomized for 20 hours. The time necessary to reduce the blood sugar level to 120 mg. per cent was determined. 1. Pancreas from 6 hypophysectomized dogs produced a normal insulin secretion, showing that an anterior pituitary hormone is not necessary for its production or maintenance. 2. In 14 of 17 normal dogs given anterior pituitary extract for 3 or more consecutive days and presenting diabetes (fasting blood sugar 150 mg. per cent or more) the pancreas showed diminished insulin production. 3. In animals which remained diabetic after discontinuing the injections of hypophyseal extract, the pancreas islands were markedly pathologic and the insulin secretion was practically nil. 4. When hyperglycemia existed on the 2nd to 5th day but fell later, the insulin secretion of 5 dogs was normal in 2, supernormal in 1, and less than normal in 2. Histologic examination showed a restoration of beta cells. 5. In 14 dogs resistant to the diabetogenic action of anterior pituitary extract, as shown by little or no change in blood sugar, the pancreatic secretion of insulin was normal in 6 cases, supernormal in 3, and subnormal in 5 cases. Clear signs of hyperfunction of B cells were observed. In 6 resistant animals a high blood sugar (150 mg. per cent) appeared shortly before transplanting, but insulin secretion was normal in 4, supernormal in 1, and subnormal in 1 case. 6. With one injection of extract and 1 day of hyperglycemia the capacity of the pancreas to secrete insulin was not altered. 7. A high blood sugar level lasting 4 days does not alter the islets. The hypophyseal extract acts, therefore, by some other mechanism. In normal dogs, the continuous intravenous infusion of glucose for 4 days maintained the blood sugar at levels as high as those after pituitary extract. In these animals the B cells were hyperplastic and insulin secretion normal. 8. Anterior hypophyseal hyperglycemia is due at first to extrapancreatic factors which are the most important, and last only during the injections of extracts. Pancreatic factors appear afterwards and are responsible for permanent diabetes. Hypophyseal extract produces histological changes in many tissues and damages the Langerhans islands. The coexistent high blood sugar probably exhausts the B cells and exaggerates their injury. 9. In all cases there is a relation between the cytology of the islet B cells and the insulin secreting capacity. PMID- 19871206 TI - THE EFFECT OF EXTERNAL TEMPERATURE ON THE COURSE OF INFECTIOUS MYXOMATOSIS OF RABBITS. AB - Rabbits, convalescent from vaccinia and in good general health, were subjected to infection with myxoma during a period of exposure to a high external temperature. It was observed that in proportion as the temperature was elevated, a profound change in the course of the myxoma infection occurred. At the highest temperatures, the disease was held completely in abeyance, and no lesions appeared within 17 days of observation. At lower temperatures, lesions appeared which tended to be circumscribed, and which reached their maximum development within 6 or 8 days after inoculation. Regression then set in and complete healing occurred. There was wide variation in the degree of protection which a given temperature conferred on an individual rabbit as measured by the amount of virus required to cause infection, although for single animals the difference in concentration of virus required to produce consistently positive and consistently negative results was not apparently different from that obtaining in the controls. With the data at hand, it does not appear justifiable to draw final conclusions as to the state of immunity of the animals which survived the modified infection. PMID- 19871207 TI - COMPARATIVE STUDY OF MENINGOPNEUMONITIS VIRUS, PSITTACOSIS OF PIGEON ORIGIN, AND PSITTACOSIS OF PARROT ORIGIN. AB - Comparative morphological, histological, and biological studies suggest a close relationship between the meningopneumonitis virus of Francis and Magill and a virus recovered from thiamin-deficient pigeons. Both of these viruses are morphologically identical with typical psittacosis, and it seems probable that they are biologically modified strains of psittacosis. They both differ from typical psittacosis in that they are regularly more pathogenic for the pigeon after intracranial injection, and fail to produce hepatic necrosis after intraperitoneal injection in mice. A virus recently isolated from human cases of atypical pneumonia by Eaton, Beck, and Pearson may also be closely related to these two viruses. A number of psittacosis viruses of pigeon origin showed a similarly increased pathogenicity for pigeons by the intracerebral route, as compared with psittacosis viruses of parrot origin. The viruses of parrot origin, however, commonly produced latent infection in pigeons even when clinical illness was not evidenced. For the isolation of psittacosis of pigeon origin from human sputum the intracranial injection of mice or pigeons may be essential, although it is probable that the intranasal injection of mice would be successful. The intraperitoneal injection of mice may give negative results. PMID- 19871208 TI - LYMPHOCYTIC CHORIOMENINGITIS IN THE SYRIAN HAMSTER. AB - The virus of lymphocytic choriomeningitis produces an intense systemic infection in Syrian hamsters with few if any clinical and pathological signs of disease. Specific soluble antigen is demonstrable in the spleen of infected animals until about the 14th day when antisoluble substance antibodies make their appearance. Circulating virus disappears after the 4th week and neutralizing antibodies are present in serum in detectable amounts shortly thereafter; both types of antibody persist for at least several months. The viruses of St. Louis encephalitis and lymphocytic choriomeningitis can be concurrently passed in series in the brains of hamsters. The resultant disease is indistinguishable from that caused by the virus of St. Louis encephalitis alone. PMID- 19871209 TI - THE BACTERICIDAL ACTION OF PROPYLENE GLYCOL VAPOR ON MICROORGANISMS SUSPENDED IN AIR. I. AB - It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed. With lesser concentrations of propylene glycol, rapid and marked reduction in the number of air-borne bacteria occurred, but complete sterilization of the air required a certain interval of time. Pronounced effects on both pneumococci and hemolytic streptococci were observed when concentrations as low as 1 gm. of glycol to fifty million cc. of air were employed. Numerous control tests showed that failure of the glycol-treated microorganisms to grow on the agar plates was due to actual death of the bacteria. The means by which propylene glycol vapor produces its effect on droplet-borne bacteria is discussed and data relating the bactericidal properties of propylene glycol in vitro to the lethal action of its vapor is presented. Atmospheres containing propylene glycol vapor are invisible, odorless, and non-irritating. This glycol is essentially non toxic when given orally and intravenously. Tests on possible deleterious effects of breathing propylene glycol containing atmospheres over long periods of time are being carried out. PMID- 19871210 TI - STUDIES IN RODENT POLIOMYELITIS : I. FURTHER EXPERIMENTS WITH THE MURINE STRAIN OF SK POLIOMYELITIS VIRUS. AB - 1. SK murine virus maintained over more than 200 serial mouse passages increased in virulence for mice from an initial intracerebral titer of about 1:1 million to a maximum titer of not less than 1:1 billion dilution activity. 2. Following intracerebral injection with murine virus of remote mouse passages, 5 of 13 rhesus monkeys developed a characteristic encephalitic syndrome. Repeated intravenous injection of massive doses of virus caused localized flaccid paralysis in 2 of 14 monkeys. 3. Intracerebral injection of graded doses of murine virus into mice of different age groups caused fatal paralysis in young and old animals alike. Infection with small doses of virus by peripheral routes, while uniformly fatal to young mice, was followed by survival of almost half of the old mice. 4. The incubation period of the disease in young mice infected intracerebrally with a standard dose of murine virus, when studied throughout the period of 1 year, was found considerably lengthened during the summer months. 5. Cross neutralization tests furnished no evidence for any serological relationship between SK murine virus and lymphocytic choriomeningitis virus. Theiler's virus was found to be neutralizable by antimurine horse serum and, to a lesser extent, by concentrated antipoliomyelitis horse serum; however, such inactivation, in both cases, was distinctly inferior to that occurring with SK murine virus. On the other hand, no neutralization whatsoever was obtained between SK murine virus and normal adult mouse serum, whereas the same serum completely neutralized Theiler's virus. Mice surviving infection with Theiler's virus, though acquiring immunity to this virus, remained fully susceptible to reinfection with SK murine virus. 6. Neutralization tests with SK murine virus against poliomyelitis convalescent monkey sera gave irregular results, but neutralization of murine virus occurred regularly with a hyperimmune antipoliomyelitis horse serum. Hyperimmune antimurine horse and rabbit sera, on the other hand, failed to inactivate three strains of monkey poliomyelitis virus (SK, RMV, Aycock) by intracerebral tests in monkeys. The same sera inactivated murine virus in mice by intraperitoneal, but not by intracerebral injection of virus-serum mixtures. 7. The identity of SK murine virus and its relation to other rodent strains of poliomyelitis virus is discussed on the basis of the available data. PMID- 19871211 TI - STUDIES IN RODENT POLIOMYELITIS : II. CULTIVATION OF THE MURINE STRAIN OF SK POLIOMYELITIS VIRUS. AB - 1. The murine virus may be grown in embryonic mouse brain-serum ultrafiltrate cultures. The virus fails to grow in embryonic chick tissue cultures or in fertilized egg preparations. 2. Some relationship can be demonstrated between the amount of nervous tissue and the infectivity of the culture. 3. Optimum titers of virus potency (10(-6)) can be obtained by adjusting the pH of the growing culture at 7.3 to 7.6. 4. A simple pH inactivation curve for virus alone and for virus when actively growing in tissue culture has been obtained. 5. The rate of virus propagation, as determined by potency tests in mice, has been established for cultures which were seeded with large or small amounts of virus. The murine virus "grows" relatively fast. The optimum titer for a large inoculum was reached in 19 hours, for a small inoculum in 72 hours. 6. With extended subcultivation in vitro the cultured virus shows a loss of infectivity for mice by peripheral injection. However, potency as determined by intracerebral injection remains constant. 7. Mice surviving inoculation of culture virus by routes other than intracerebral acquire a relative resistance to reinfection with mouse passage virus. 8. The murine culture virus passes without difficulty through collodion membranes with an A.P.D. of 30 mmicro. Its particle size may therefore be estimated as lying between 10 to 15 mmicro. 9. On a basis of in vitro activity and cross infection, the murine culture virus is distinct from the virus of lymphocytic choriomeningitis. 10. Murine culture virus may be used as an interfering agent to block infection with poliomyelitis virus in monkeys. The interaction between the two viruses seems to be quantitatively limited. Such interference, with the present potency of culture virus, operates effectively only against comparatively small doses of monkey virus. PMID- 19871212 TI - MORPHOLOGICAL STRUCTURE OF THE VIRUS OF VACCINIA. AB - The pictorial data obtained by means of the electron microscope indicate a remarkable regularity in the morphology of the elementary body of vaccinia. The virus particles apparently have internal structure and some sort of limiting membrane. PMID- 19871213 TI - THE HISTOGENESIS OF CELLS IN EXPERIMENTAL PNEUMONIA IN THE DOG. AB - The kinds of cells and the sequence in which they appeared in the inflammatory exudate were studied in a series of experimentally produced pneumonic lesions in dogs. There was a gradual and progressive change in the character of the exudate and the kinds of cells as the disease progressed. The microscopic findings could be more closely correlated with the age of the lesions than with their gross appearance or with the clinical condition of the animal at the time of death. The cells in the exudate came principally from the blood. The polymorphonuclear leucocytes were gradually replaced by larger phagocytic mononuclear cells. These were derived chiefly from the hypertrophy and transformation into larger phagocytic cells of the lymphocytes and monocytes of the blood after they entered the air spaces along with the polymorphonuclear leucocytes in the early stages of the disease. To follow the development of the hematogenous exudate cells into macrophages in the dog, the pneumonic process must be studied from its earliest inception and at close stages during the first 36 hours of the disease. The local septal cells contributed only in a minor way to the origin of the macrophages. Their principal reaction appeared to be one of enlargement without detachment from the alveolar walls. Consolidation of the lungs occurred as a result of the spread of the pneumococci through the air spaces by direct passage of the infected edema fluid from alveolus to alveolus through the pores of Kohn and from bronchiole to bronchiole from aspiration during breathing and coughing. The similarity of the histogenesis of the exudate cells in this series of experimentally induced pneumonic lesions in the dog and in those which occur spontaneously in man was discussed. PMID- 19871214 TI - THE EFFECTS OF RENAL HYPERTENSION ON THE VESSELS OF THE EARS OF RABBITS. AB - 1. The present experiments demonstrate by direct observation that peripheral arterioles in moat chambers in rabbits' ears constrict during the development of renal hypertension, and that they remain persistently constricted, although not sufficiently to interrupt the blood supply to the tissues. The arteriolar constriction in the hypertensive animals was not dependent upon nerves, since it occurred in newly formed arterioles which had probably never been supplied with nerves, as well as in older arterioles with a functional nerve supply. 2. No capillary constriction was observed during or following the development of hypertension, although the walls of the capillaries could be very clearly seen. Persistent hypertension was associated in two examples with increased sticking of leukocytes to the walls of the capillaries and venules, some emigration of leukocytes, and a few small hemorrhages. 3. During development of hypertension, new arteriovenous anastomoses were observed to appear in the chambers. 4. No evidence of change was noted in the viscosity of the blood or in the appearance of the blood corpuscles in the hypertensive rabbits. 5. The constriction of the arterioles during and following the development of hypertension closely resembled that produced by intravenous injections of angiotonin. PMID- 19871215 TI - NUTRITIONAL DEFICIENCIES AS A CAUSE OF ELEVATED BLOOD PRESSURE IN RATS (WITH ESPECIAL REFERENCE TO THE VITAMIN B(2) COMPLEX). AB - The effects of dietary deficiencies on the blood pressure of rats were studied, with especial reference to vitamin B deficiencies. A deficiency of the entire vitamin B complex was followed by a slight fall in blood pressure. A deficiency of only thse heat-stable fractions was followed by a significant and persistent rise in pressure, which could be reversed by restoring these factors to the diet. Partial deficiencies were followed by a higher rise of blood pressure than were complete deficiencies, perhaps because of the debilitating effects of the latter. Even an excessive intake of the heat-stable fractions of the vitamin B complex did not prevent entirely a rise of pressure if the diet was otherwise deficient. Under the latter conditions, the rise in pressure was slower and less marked than in those animals with a deficiency of the vitamin B(2) complex only. It therefore appears that, while a deficiency of the vitamin B(2) complex plays a dominant role in causing a rise of blood pressure in rats, other dietary factors as yet undefined are also involved. From analogy with other deficiency states, it is possible that thsese undefined nutritional factors cause their effects by interfering with absorption and utilization of the vitamin B(2) complex. PMID- 19871216 TI - SELECTIVE "STAINING" FOR ELECTRON MICROGRAPHY : THE EFFECTS OF HEAVY METAL SALTS ON INDIVIDUAL BACTERIAL CELLS. AB - The physical basis of contrast and image formation in electron micrography is considered in relation to the possibility of recording selective chemical effects on cell components. A technology of selective microchemical analysis, equivalent to differential staining, is suggested as practicable in electron micrography. Electron pictures of bacteria after exposure to salts of heavy metals have shown the bacterial inner protoplasm, but not the cell walls, to be selectively darkened; shrinkage, coagulation, or escape of protoplasm from the injured cells may result and be recorded in the electron micrographs. Recording of the action of germicidal agents on individual bacterial cells is indicated as one promising field of application of microchemical analysis with the aid of the electron microscope. PMID- 19871217 TI - A SEROLOGICAL CLASSIFICATION OF VIRIDANS STREPTOCOCCI WITH SPECIAL REFERENCE TO THOSE ISOLATED FROM SUBACUTE BACTERIAL ENDOCARDITIS. AB - A total of 108 strains of viridans streptococci from subacute bacterial endocarditis, and 99 strains from human throats and extracted teeth have been studied, and approximately two-thirds of all the strains so far have been differentiated into a number of serological groups. The similarity between strains from these sources is evident from the fact that approximately 50 per cent of the reacting strains from each source fall into two groups I and II, and that three groups I, II, and IV, contain streptococci from both sources in approximately the same distribution. Fifteen vaginal strains of viridians streptococci failed, with the exception of one strain, to react with groups I-IV of the endocarditis serums. More than three-fourths of the strains from both sources were Streptococcus salivarius as determined by Sherman's criteria. However, no correlation between the biochemical and serological classification could be made. It may be concluded that the viridans streptococci are amenable to classification by serological methods. The results so far obtained do not indicate a serological difference between strains of viridans streptococci isolated from subacute bacterial endocarditis, and those isolated from human throats and extracted teeth. The greater definitive value of serological methods in the identification of a particular strain is indicated. PMID- 19871218 TI - RADIOACTIVE IRON ABSORPTION IN CLINICAL CONDITIONS: NORMAL, PREGNANCY, ANEMIA, AND HEMOCHROMATOSIS. AB - Radio iron is a tool which makes iron absorption studies quite accurate in dogs and reasonably satisfactory in human beings. This method is vastly superior to others previously used. Normal human pregnancy without significant anemia may show active radio iron absorption-16 to 27 per cent of iron intake. The pregnant woman as a rule shows 2 to 10 times the normal absorption of radio iron. Diseased states in which iron stores are known to be very abundant-pernicious anemia, hemochromatosis, familial icterus, and Mediterranean anemia -show very little absorption, probably less than normal. This is in spite of a severe anemia in all conditions except hemochromatosis. Chronic infections in spite of anemia show no utilization of radio iron, whether it may be absorbed or not. Leukemia shows little utilization of radio iron in red cells in spite of absorption (autopsy), probably because of white cells choking the red marrow. Polycythemia shows very low values for iron absorption as do normal persons. Two pregnant women showed only normal iron absorption. We believe that reserve stores of iron in the body, rather than anemia, control iron absorption. This control is exerted upon the gastro-intestinal mucosa which can refuse or accept iron under various conditions. PMID- 19871219 TI - STUDIES IN RODENT POLIOMYELITIS : III. EXPERIMENTAL POLIOMYELITIS IN GUINEA PIGS PRODUCED WITH THE MURINE STRAIN OF SK POLIOMYELITIS VIRUS. AB - 1. Murine SK poliomyelitis virus has been transferred from mouse to guinea pig with the establishment of a fixed strain of cavian passage virus. 2. The disease thus produced in guinea pigs is characterized by the occurrence of flaccid paralysis. Typical poliomyelitic lesions are found in the anterior horn of the spinal cord. 3. Guinea pigs are susceptible to infection with murine virus by the intracerebral, intravenous, intraperitoneal, and subcutaneous route; cavian passage virus produces paralysis only upon intracerebral or intravenous injection. Neither virus paralyzes guinea pigs by feeding or nasal instillation. 4. The potency of the virus (murine or cavian) in guinea pigs is considerably lower than in mice and compares with the titer of the original SK strain in monkeys. In paralyzed guinea pigs the virus is found only in the central nervous system and not in extraneural sites, such as blood or abdominal viscera. 5. Attempts to cultivate cavian passage virus in tissue culture have yielded evidence of some in vitro propagation but no passage virus has as yet been obtained by this method. 6. Cross neutralization tests with cavian passage virus in guinea pigs and with murine virus in mice have established the serological identity of the two viruses. Inactivation of cavian passage virus in guinea pigs by poliomyelitis-convalescent monkey sera is irregular. Complete neutralization has been obtained with a concentrated poliomyelitis horse serum. 7. Resistance to reinfection with potent virus can be demonstrated in convalescent guinea pigs as well as in guinea pigs which have survived a symptomless infection with either murine or cavian virus. This immunity is demonstrable by the power of the serum of such animals to neutralize the virus in vitro and by the ability of nerve tissue to dispose in vivo of the infectious agent. 8. Cavian passage virus has a limited pathogenicity for rhesus monkeys. Of a total of 35 monkeys injected intracerebrally with guinea pig passage virus 26 failed to respond with any manifest symptoms of disease; 8 monkeys showed various signs of definite involvement of the central nervous system consisting of tremor, convulsions, facial palsy, and localized pareses; 1 monkey developed typical flaccid paralysis. 9. Following injection with cavian virus the virus may be recovered from the tissues of normal monkeys but not from the tissues of convalescent monkeys shortly after a paralyzing attack of poliomyelitis due to SK or Aycock virus. 10. Immunization of monkeys with early cavian passage virus by the subcutaneous route has given no clear-cut evidence of protection against intracerebral reinfection with SK poliomyelitis virus. Neither has there been any evidence of effective interference in monkeys injected intravenously with early cavian passage virus and intracerebrally with RMV poliomyelitis virus. 11. The bearing of the experimental data upon the epidemiology of the human disease is discussed. PMID- 19871220 TI - STUDIES IN RODENT POLIOMYELITIS : IV. THE PATHOLOGY OF MURINE AND CAVIAN POLIOMYELITIS. AB - A description has been given of the lesions produced in mice and guinea pigs by inoculation of the Jungeblut-Sanders virus. The histopathological findings, although in themselves not conclusive, would tend to support the opinion that Jungeblut and Sanders have transmitted the SK poliomyelitis virus to mouse and guinea pig. In mice the virus apparently retains its affinity for the anterior horns of the spinal cord, but in a moderate degree. Associated with a marked increase in virulence of the virus, a strong affinity for the cerebral tissues, more particularly the olfactory centers, develops. On transmitting this murine variant of the virus to guinea pigs, however, the original character of the virus is again revealed. There is a reversion to a predominant affinity for the nerve cells of the anterior horns of the spinal cord. PMID- 19871221 TI - DISTRIBUTION OF THE Rh FACTOR IN AMERICAN INDIANS. AB - Erythrocytes from 120 full blooded American Indians and 155 Indians of mixed ancestry were tested for the Rh agglutinogen. Only a single blood among the full blooded Indians appeared to lack this factor, and in the Indians known not to be full blooded, the distribution of this (and other) blood properties was found to be intermediate between that for whites and pure Indians according to expectation. A variant of Rh demonstrable by a special human serum was more than twice as frequent in full blooded Indians as in white individuals. PMID- 19871222 TI - THE PATHOGENESIS AND PATHOLOGY OF EXPERIMENTAL TYPE I PNEUMOCOCCIC PNEUMONIA IN THE MONKEY. AB - The pathogenesis of lobar consolidation and microscopic pathology of induced Type I pneumococcic pneumonia in a series of fourteen monkeys, killed at close intervals of time after infection, have been studied. The inflammatory process which resulted in consolidation was primarily intraalveolar and intrabronchial. The pneumococci spread within the air spaces as a result of the dissemination of the infected edema fluid directly from alveolus to alveolus through the pores of Kohn and from bronchiole to bronchiole as a result of repeated aspiration during breathing. The pneumonic process within the air spaces developed and progressed independently of the reaction in the interstitial tissues. The organisms spread to the interstitial tissue secondarily from the alveolar spaces. Once in the interstitial tissues they appeared to be the important source of infection producing bacteremia but not important in the mechanism by which consolidation was produced. The exudate cells came chiefly from the blood. The large mononuclear cells which replaced the polymorphonuclear leucocytes were derived principally from the hypertrophy and transformation of lymphocytes and monocytes into macrophages after they entered the exudate in the early stages of the disease. The part the local septal cells played as the source of the macrophages could not be accurately determined. The reaction of the septal cells appeared to be chiefly one of swelling without detachment and occasional proliferation to form binucleated attached cells. To follow the transformation of the hematogenous mononuclear cells into macrophages in the exudate, the inflammatory reaction must be examined at frequent intervals during the first 36 hours of the disease. The similarity of the pathogenesis of lobar consolidation in human pneumonia to that observed in the experimentally induced disease in monkeys and dogs was discussed. PMID- 19871223 TI - FUNCTION OF COMPONENTS OF COMPLEMENT IN IMMUNE HEMOLYSIS. AB - 1. At a temperature of 1 degrees C., C'2, C'4, and C'1 combine with sensitized sheep erythrocytes, while C'3 does not combine. 2. C'1, although combining with sensitized cells in the absence of C'4, is hemolytically inert unless C'4 combines previous to, or simultaneously with it. 3. C'4 does not combine in the absence of C'1. 4. Although C'3 is not fixed by antibody-sheep cell aggregates, it is essential for hemolysis, operating on the sensitized red cell after the fixation of C'4, C'2, and C'1 and behaving as if it were a catalyst. PMID- 19871224 TI - STUDIES IN RODENT POLIOMYELITIS : V. INTERFERENCE BETWEEN MURINE AND MONKEY POLIOMYELITIS VIRUS. AB - 1. The murine strain of SK poliomyelitis virus interferes with the propagation in rhesus monkeys of SK, Aycock, and RMV poliomyelitis monkey virus. 2. This interference is demonstrable by intracerebral injection of mixtures of murine and monkey virus prepared in vitro as well as by separate injection of the two viruses by diverse routes. 3. Mixture tests carried out with graded doses of murine and monkey virus show that 0.5 cc. of a 10 per cent suspension prepared from the brains of paralyzed mice is capable of counteracting at least 100 minimal paralyzing doses of two strains of monkey virus. 4. No interference was demonstrable with suspensions of brains infected with murine virus which had been inactivated by heating for (1/2) hour at 75 degrees C., or with suspensions prepared from normal mice, or with brain suspensions prepared from mice infected with herpes virus. 5. When murine virus is introduced into monkeys by the intravenous route, before or after intracerebral infection with monkey virus, distinct prophylactic or therapeutic results may be obtained. 6. Analysis of the figures shows that the success of interference depends upon (a) the size of the infecting dose of monkey virus, (b) the amount of murine virus injected, and (c) the choice of proper intervals between the injection of monkey and murine virus. 7. The mechanism of the interference phenomenon here described is discussed in the light of the available data. PMID- 19871225 TI - HEPATIC VITAMIN A IN THE RAT AS AFFECTED BY THE ADMINISTRATION OF DIBENZANTHRACENE. AB - 1. The decreased concentrations of vitamin A in the livers of rats given dibenzanthracene probably are due to a particular effect of the carcinogen on the ability of the liver to store the vitamin and not to the production of general hepatic dysfunction. 2. The administration of dibenzanthracene to normal rats does not (a) increase significantly their hepatic content of total fat nor decrease that of phospholipid; (b) impair the ability of their livers to fabricate serum albumin; (c) impair the capacity of their livers to esterify cholesterol or phenol; (d) interfere with the hepatic synthesis and conjugation of glucuronic acid; or (e) interfere with the hepatic storage of riboflavin. 3. The simultaneous ingestion of yeast by the dibenzanthracene-treated rats further depletes their hepatic stores of vitamin A. This depletion conceivably is due to the fact that yeast alone also might deplete the liver of its vitamin A and thus a summation of two similar effects is attained. 4. The results suggest a competition between vitamin A and dibenzanthracene for some substance, possibly a protein, to which vitamin A may be bound in the liver. PMID- 19871226 TI - CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : VI. STUDIES ON THE NATURE OF THE ENZYMES ASSOCIATED WITH THE PURIFIED VIRUS. AB - Purified elementary bodies of vaccinia have been tested with a variety of substrates and found to possess phosphatase, catalase, and lipase activity. Tests for malate, succinate, pyruvate, and lactate dehydrogenases were negative. Interpretation of these results is complicated by the observation that elementary bodies of vaccinia adsorb relatively large quantities of certain enzymes from dilute solutions. These enzymes are not eluted by procedures of washing and centrifuging similar to those carried out in the preparation of the virus. For this reason, the presence of phosphatase, catalase, and lipase in the purified virus may well be accounted for on the basis of adsorption from the host tissues which are known to be rich in these particular enzymes. That some degree of specificity in this adsorption is to be recognized is shown by the failure of the virus to adsorb urease, an enzyme of vegetable origin. Until some method can be devised which will distinguish between the enzymes of the host cell and those which may be integral parts of the virus it would seem that the problem of the enzyme constituents of vaccine virus is incapable of definite solution. PMID- 19871227 TI - THE REACTION BETWEEN THE ENZYME TYROSINASE AND ITS SPECIFIC ANTIBODY. AB - 1. Antibodies to the enzyme tyrosinase, obtained from the mushroom Psalliota campestris, have been produced in rabbits and human beings. 2. These antibody preparations, though precipitating the enzyme from solution, do not affect its catalytic activity. PMID- 19871228 TI - A NON-VIRULENT, SINGLE-DOSE RABIES VACCINE FOR PROPHYLACTIC IMMUNIZATION OF DOGS. AB - Our studies on rabies vaccines thus far have led us to the view that in order to develop and test vaccines, quantitative methods are necessary, and that such quantitative methods may be exploited to greatest advantage by using mice, preferably W-Swiss, as the test animal. Dogs, due to their variability and susceptibility to intercurrent infections when kept under experimental conditions, are useful chiefly to check whether or not a vaccine produces a high grade of immunity; they remain of limited value in testing the comparative potencies of weak vaccines. A second point is that the Pasteur strain of virus has proved as potent as any tested for the preparation of vaccines. Another point is that virus material for preparing vaccines must titre at least 330,000 mouse doses per cc. to be effective. This requirement has eliminated all culture vaccines thus far reported, with the possible exception of Plotz's (7) and leaves virus-containing brain tissue as the sole potent source of vaccine. In summary, we believe that a single injection of non-virulent irradiated vaccine, prepared as herein described, immunizes mice and dogs effectively against a subsequent test inoculation of virulent rabies virus and does so to a greater degree than do other vaccines now obtainable. It is easily and quickly prepared, keeps well, and has a low nitrogen content. PMID- 19871229 TI - ADSORPTION OF INFLUENZA HEMAGGLUTININS AND VIRUS BY RED BLOOD CELLS. AB - A number of experiments were performed on the adsorption of influenza hemagglutinins on chicken red blood cells, from which the following conclusions were drawn:- 1. When chicken red blood cells and preparations of influenza viruses were mixed together, the influenza hemagglutinins present were rapidly adsorbed onto the cells. After varying lengths of time, dependent on the conditions of the experiment, the adsorbed hemagglutinins began to elute from the cells. With the Lee strain at 23 degrees C. and the PR8 strain at 37 degrees C. almost all of the adsorbed agglutinin was released in 4 to 6 hours. 2. When the number of red cells used for adsorption was increased, the speed and degree of adsorption of the hemagglutinins increased. The time of maximum adsorption of hemagglutinins was the same, regardiess of red cell concentration, and with the larger amounts of red cells the speed and degree of elution was decreased. 3. When adsorption of PR8 virus agglutinins was carried out at 4 degrees C. the adsorption was rapid and nearly complete. When the reaction was carried out at higher temperatures (27 degrees and 37 degrees C.), the adsorption was equally rapid but was progressively less complete with rise in temperature. At 4 degrees C. the maximum adsorption was not reached for 5 hours; at 27 degrees C. it was reached in 25 minutes; and at 37 degrees C. the greatest degree of adsorption was attained between 3 and 5 minutes. The amount of elution observed at 4 degrees C. at 18 hours was negligible, but the degree of elution increased with temperature so that at 37 degrees C. almost all of the adsorbed agglutinin was released in 6 hours' time. 4. Red cells which had adsorbed and then fully eluted the agglutinin were not capable of adsorbing a detectable amount of fresh agglutinin. In addition, such cells would no longer agglutinate even though exposed to fresh virus suspensions. 5. The hemagglutinin of influenza B virus was capable of being adsorbed on and eluted from several successive lots of chicken red cells without appreciable loss of agglutinating activity. 6. The hemagglutinins of the PR8 and Lee strains were rapidly inactivated at 60 degrees C. The presence of active virus was not necessary for the occurrence of the adsorption-elution reaction on chicken red cells. 7. The activity of the portion of the red cells responsible for the adsorption of the hemagglutinins persisted, though in reduced amount, even after heating for 5 minutes at 100 degrees C. Hemagglutinins were adsorbed and eluted from red cell stroma. 8. The infective agent in influenza virus suspensions was adsorbed by chicken red cells simultaneously with the adsorption of hemagglutinins. 95 per cent of the infective agent was removed from suspension by the red cells after contact for 15 minutes. From then on the infective agent was gradually released from the red cells. After 4 hours the 50 per cent mortality titer of the supernatant fluid was as high as at the beginning of the experiment. PMID- 19871230 TI - THE MANUFACTURE OF ANTIBODIES IN VITRO. AB - A protein solution with the properties of a specific antiserum to the triphenylmethane dye methyl blue has been made by treating a solution of bovine gamma-globulin and the dye with alkali and then slowly neutralizing the alkali. Some success has been obtained also in the formation of antibodies from other serum proteins and by other denaturation-renaturation procedures. By heating solutions of gamma-globulin and antigen to 57 degrees C. for several days antisera homologous to the antigens have been prepared. This method has been used successfully with the azodye 1,3-dihydroxy-2,4,6-tri(p-azophenyl-arsonic acid) benzene and with pneumococcus polysaccharide Type III. The antipneumococcus sera were found to precipitate the polysaccharide of Type III but not those of Types I and VIII and to agglutinate pneumococci of Type III but not those of Types I and II. PMID- 19871231 TI - THE ACTION OF EXTREME COLD ON LEUKEMIC CELLS OF MICE. AB - Suspensions of leukemic cells of mice from three different strains of leukemia were subjected to rapid or slow freezing and rapid or slow thawing. Suspensions rapidly frozen to -196 degrees C. were in all cases innocuous, whereas those frozen slowly were capable of transmitting leukemia. The infectivity of slowly frozen material varied from an estimated 0.0001 per cent to 1 per cent of that of fresh material, and this figure probably represents the percentage of surviving leukemic cells. Particles of spleen and lymph node reacted to slow and rapid freezing in the same manner as suspensions prepared from them. For one of the strains rapid thawing was less injurious than slow thawing; for the other two the rate of thawing seemed to be immaterial. Infectivity was equally well preserved after freezing to -21 degrees C. whether freezing occurred spontaneously after supercooling or was initiated near the freezing point by inoculation with ice, or whether thawing was slow or rapid. Suspensions already slowly frozen at temperatures of -2 degrees or lower, whether spontaneously or by inoculation with ice, could no longer be completely inactivated by subsequent rapid cooling to 196 degrees C. Unfrozen suspensions initially above the freezing point or supercooled to -2 degrees C. or -8 degrees C. and then rapidly cooled to -196 degrees C. were inactivated. This protective action of previous slow freezing was most marked when the initial temperature of the frozen suspension was -15 degrees C. or lower; when it was -2 degrees C. protection was barely detected. These observations indicate that the changes which are peculiar to rapid freezing alone and lead to complete inactivation take place during rapid transition from the liquid to the solid state, in a range of temperature lying between -15 degrees C. and the freezing point. Temperature measurements carried out in this range showed that suspensions were about equally infections whether the temperature at their centers dropped from 0 degrees C. to -15 degrees C. in 30 minutes or in 1 minute; when the drop occurred in 12 seconds or less, the suspensions became innocuous. PMID- 19871232 TI - STUDIES ON THE NUTRITION OF HEMOPHILUS INFLUENZAE : I. THE RELATIONSHIP BETWEEN THE UTILIZATION OF COENZYME AND HEMIN AND THE REDUCTION OF NITRATE. AB - The metabolic activity of H. influenzae can be followed quantitatively by measurement of the nitrite produced in a medium containing 0.2 per cent potassium or sodium nitrate. When X-factor, or hemin, and other specific substances required for the optimum growth of H. influenzae, are present in excess, the nitrite produced by this organism is quantitatively related to the concentration of V-factor, or total coenzyme. This quantitative relationship has been demonstrated for five strains of H. influenzae. It has been shown that various media, which in the past have been used for the determination of coenzyme by growth of H. influenzae, have in many instances been deficient in X-factor and that this substance rather than coenzyme has been the specific factor limiting growth. When 0.5 per cent blood is added to a basal proteose-peptone medium the specific requirements for optimum growth and metabolic activity of H. influenzae, other than coenzyme, are met, and a large number of specific biocatalysts and nutritive substances added to this medium are without effect in stimulating further growth. The foregoing studies have formed the basis for a quantitative method for the determination of total coenzyme in blood and tissue. This method is being described elsewhere. PMID- 19871233 TI - RECIPROCAL TRANSMISSION TESTS WITH INFECTIOUS CATARRH OF CHICKENS, MICE, AND RATS. AB - Infectious catarrh of chickens (fowl coryza of slow onset) was not transmissible to mice or rats by nasal instillation of the specific coccobacilliform bodies. Exudates were also inactive in both rodents on foot pad injection. The infectious catarrhs of the mouse and the rat were reciprocally transmissible by the nasal injection of exudates or tissue cultures of the respective coccobacilliform bodies and by direct contact. Exudates and cultures also produced an arthritic reaction in both hosts on foot pad injection. The coccobacilliform bodies of mouse catarrh were innocuous in chickens on nasal instillation, whereas those of rat catarrh were established locally but were maintained for only two passages. In the opposite host each of the two rodent forms of infectious catarrh reproduced the typical features of the naturally acquired disease, a highly fatal pneumonia being characteristic of the mouse but not of the rat. PMID- 19871234 TI - EXPERIMENTAL INFECTION OF THE CHICK EMBRYO WITH THE VIRUS OF PSEUDORABIES. AB - The chick embryo responds to experimental infection with the virus of pseudorabies with a disease pattern simulating the natural infection. Virus lesions of the membrane are followed by infection of all tissues of the central nervous system. Fixed strains produce a hemorrhagic destruction of the central nervous system of the embryo, which is referable to destruction of blood vessel endothelium. Field strains lack the hemorrhagic tendency, but infect the brain when inoculated on the membrane. Neutralization of the virus by specific hyperimmune serum can be demonstrated by inoculation on the membrane. The reaction of the embryo to the virus varies with the age of the embryo. This is reflected both in the membranal lesion and in the subsequent encephalitis. PMID- 19871235 TI - STUDIES IN THE PATHOGENESIS OF EXPERIMENTAL DYSENTERY INTOXICATION. AB - The intravenous injection of Shiga toxin into dogs causes a rise in hemoglobin, red blood cell count, hematocrit reading, and specific gravity of the whole blood. There is thus a decrease in circulating blood volume. The specific gravity of the blood plasma does not change. These findings indicate that the toxin of B. shigae produces a shock-like circulatory state. As a result there occurs a compensatory vasoconstriction in the duodenum of the dog and in the cecum of the rabbit. It has been shown that the toxin of B. shigae has no direct effect upon the intestinal mucosa when brought into contact therewith, but that its absorption through the mucosa leads to the appearance of a lesion in the duodenum of the dog. Therefore we interpret the pathological alterations in the intestinal tract, following the injection of Shiga toxin, as the anatornic end result of a pronounced and prolonged homeostatic vasoconstriction. PMID- 19871236 TI - HEMOGLOBIN PRODUCTION FACTORS IN THE HUMAN LIVER : ANEMIAS, HYPOPROTEINEMIA, CIRRHOSIS, PIGMENT ABNORMALITIES, AND PREGANCY. AB - Human liver tissue has been assayed to determine the amount of hemoglobin production factors in normal and abnormal states. Standardized dogs made anemic by blood removal have been used in this biological assay. Normal animal liver as control is rated as 100 per cent. Normal human liver tissue as compared with the normal animal control contains more of these hemoglobin production factors-a biological assay ratio of 120 to 160 per cent. Infections, acute and chronic, do not appear to modify these values, the concentration of hemoglobin-producing factors falling within the normal range. Pernicious anemia and aplastic anemia both show large liver stores of hemoglobin-producing factors-a biological assay ratio of 200 to 240 per cent. Therapy in pernicious anemia reduces these liver stores as new red cells are formed. Secondary anemia presents a low normal or subnormal liver store of hemoglobin-producing factors-an assay of 60 to 130 per cent. Hemochromatosis, erythroblastic anemia, and hemolytic icterus in spite of large iron deposits in the liver usually show a biological assay which is normal or close to normal. Polycythemia shows low reserve stores of hemoglobin-producing factors. Leukemias present a wide range of values discussed above. Hypoproteinemia almost always is associated with low reserve stores of hemoglobin producing factors in the liver-biological assays of 60 to 80 per cent. Hypoproteinemia means a depletion of body protein reserve stores including the labile protein liver reserves-a strong indication that the prehemoglobin material (or globin) is related to these liver stores. Pregnancy, eclampsia, and lactation all may present subnormal liver stores of hemoglobin-producing factors. Exhaustion of protein stores lowers the barrier to infection and renders the liver very susceptible to many toxic substances. It should not be difficult to correct hypoproteinemia under these conditions and thus relieve the patient of a real hazard. PMID- 19871237 TI - A GENERALIZED VISCERAL DISEASE OF GUINEA PIGS, ASSOCIATED WITH INTRANUCLEAR INCLUSIONS. AB - A spontaneous generalized visceral disease of guinea pigs, characterized by the presence of intranuclear inclusion bodies of the herpes type, is described. The possible relation of this disease to the salivary gland virus infection of guinea pigs is discussed. PMID- 19871238 TI - STUDIES CONCERNING THE SITE OF RENIN FORMATION IN THE KIDNEY : III. THE APPARENT SITE OF RENIN FORMATION IN THE TUBULES OF THE MESONEPHROS AND METANEPHROS OF THE HOG FETUS. AB - 1. Renin was found in both the mesonephric and metanephric kidneys of the smallest hog fetuses examined. These were from 17 to 24 mm. in length in the case of the former, and 25 to 49 mm. in that of the latter. 2. No evidence was found in either type of kidney of juxtaglomerular cells described by Goormaghtigh as the probable site of renin formation. 3. The renin content in both the mesonephros and the metanephros was found to be independent of its arteriologlomerular component but directly dependent upon the number, size, and functional state of the tubular component. It increased in amount with increasing tubular proliferation during the course of embryonic development, and decreased with the progressive tubular atrophy and degeneration incident thereto. 4. The site of renin formation is discussed. PMID- 19871239 TI - EFFECTS OF EXCESS DIETARY CYSTEIC ACID, dl-METHIONINE, AND TAURINE ON THE RAT LIVER. AB - 1. Cysteic acid fed to albino rats as 12.5 to 15 per cent of the McCollum stock diet caused portal necrosis and cirrhosis of the liver within 2 weeks. Concentrations of cysteic acid of 6.25 per cent or less in the diet produced no liver lesions within 2 weeks. 2.dl-Methionine fed as 6.4 to 12.4 per cent of the McCollum stock diet or of a low protein, low fat diet, resulted in severe atrophy of the liver cells but no cirrhosis of the liver. 3. Taurine fed as 1 to 10 per cent of the McCollum stock diet produces no liver lesions. 4. For reasons discussed in the paper, it is concluded that the liver necrosis and cirrhosis produced by cystine and cysteic acid are not dependent upon the S-S linkage of the cystine, the oxidation of the sulfur, the formation and excretion of large amounts of urinary sulfate, or the presence of an amino group separated from a sulfur molecule by a 2 carbon chain. PMID- 19871240 TI - STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : VI. FACILITATION OF INFECTION IN THE MOUSE. AB - 50 per cent glycerine injected intraperitoneally, intramuscularly, or intravenously, greatly enhances the activity of equine encephalomyelitis virus injected intramuscularly, increasing its virulence up to 100-fold. The same effect is produced by very concentrated sodium chloride. The result appears due to dehydration of the nervous system, suddenly produced. Gradual withdrawal of body fluids, produced by depriving animals of drinking water, results in sharp concentration of the blood, equal to that produced by glycerine or salt. But such deprivation of water alone does not result in significant dehydration of the brain, nor does it have any effect on virus action. The facilitation effect is not produced by drastic procedures involving shifts of electrolytes without loss of total water from the brain. Glycerine has no facilitating action when the virus is administered intranasally or intraocularly, suggesting a fundamental difference in pathogenesis between these routes and the intramuscular. PMID- 19871241 TI - THE FORMATION OF ANTIBODIES IN THE POPLITEAL LYMPH NODE IN RABBITS. AB - Typhoid vaccine and sheep erythrocytes were injected subcutaneously into the feet of rabbits, and the subsequent formation of agglutinins and hemolysins in the popliteal lymph node was compared with the output of lymphocytes through the efferent lymph and with changes in the lymph node. Antibodies began to appear in the efferent lymph 2 to 4 days after the injection of the antigen and reached their highest titer after 6 days. This was preceded by a sharp rise in the output of lymphocytes through the efferent lymph, while in the lymph node there was lymphatic hyperplasia after preliminary infiltration of granulocytes and monocytes. This hyperplasia was first of a diffuse type, but was later superseded by large so called germinal centers, the latter lagging somewhat behind the rise in antibody titer. The fact that the tissue response accompanying the formation of antibodies was chiefly a lymphocytic one points to the lymphocyte as a factor in the formation of antibodies. PMID- 19871242 TI - SIMULTANEOUS RENAL AND HEPATIC EXCRETION OF WATER, CYANOL, AND AZOFUCHSIN I IN RABBITS. AB - 1. The renal and hepatic excretion of water, cyanol, and azofuchsin I was studied in rabbits under various conditions. It was observed that under the conditions of our experiments the urine rate was independent of the bile rate, and vice versa. The renal excretion of these dyes also was independent of their hepatic excretion except in cases in which the liver was severely damaged. On the other hand, the hepatic excretion of these dyes depended also on their renal elimination. 2. The relationship between the renal and hepatic excretion of cyanol and azofuchsin I could be expressed in the form of hyperbolas. 3. In the use of dyes as a measure of renal function, no noteworthy error is introduced by their hepatic excretion except in cases in which the liver is severely damaged. PMID- 19871243 TI - INDUCED RESISTANCE OF THE CENTRAL NERVOUS SYSTEM TO EXPERIMENTAL INFECTION WITH EQUINE ENCEPHALOMYELITIS VIRUS : I. NEUTRALIZING ANTIBODY IN THE CENTRAL NERVOUS SYSTEM IN RELATION TO CEREBRAL RESISTANCE. AB - 1. Neutralizing antibody to equine encephalomyelitis virus was found in the spinal fluid of rabbits sufficiently vaccinated with active or formalin inactivated virus. Antibody was specific for the Western or for the Eastern virus. 2. Neutralizing capacity of spinal fluid was equivalent to that of a 1/300 dilution of serum of the same animal, and was of the same order of magnitude as that of perfused brain of a vaccinated animal. 3. Vaccinated rabbits which showed antibody in the spinal fluid resisted intracerebral or intracisternal injection of active virus. This immunity was specific, i.e., there was no cross-reaction between the Eastern and Western virus after vaccination with formalin-inactivated virus. On the other hand, lack of antibody in the spinal fluid, even when antibody was demonstrable in the undiluted serum, was associated with lack of cerebral resistance. PMID- 19871244 TI - THE CONTROL OF THE RENAL EXCRETION OF WATER : I. THE EFFECT OF VARIATIONS IN THE STATE OF HYDRATION ON WATER EXCRETION IN DOGS WITH DIABETES INSIPIDUS. AB - Water and electrolyte excretion has been studied in a series of dogs with diabetes insipidus, in which the extent of neurological damage was subsequently determined. The animals were studied before and after the introduction of variables which produce marked changes in the state of hydration,-administration and restriction of water and the substitution of 0.5 per cent sodium chloride for it as a drinking fluid. Observations were made on those factors, both general and renal, which appear to be important in determining the excretion of water and electrolyte, or which may be expected to yield information on the mechanisms by which the regulation of such excretion is achieved. These are the volume of extracellular fluid and plasma and the concentration of the contained electrolyte, glomerular filtration rate, and the excretion of electrolyte, urea, and water itself, as well as the tonicity of the urine. PMID- 19871245 TI - THE CONTROL OF THE RENAL EXCRETION OF WATER : II. THE RATE OF LIBERATION OF THE POSTERIOR PITUITARY ANTIDIURETIC HORMONE IN THE DOG. AB - 1. The administration of the posterior pituitary antidiuretic hormone by constant intravenous infusion has been used to examine the two characteristic actions of the hormone; namely, the facilitation of the active renal tubular reabsorption of water distally in the nephron and the inhibition of the renal tubular reabsorption of sodium proximally. 2. Experimental evidence was obtained which indicates that variations in the excretion of water and electrolyte involve the integration of these two actions with obscure variables which are discemible in the experimental data but are not subject to definition at this time. 3. Graded antidiuresis in the animal with diabetes insipidus, when normally hydrated, was only obtained in the range of 0.001 to 0.005 unit (pressor) per hour. This range of hormone administration was also found to be physiologically active in the normal animals. These observations together with others permit the placing of the normal rate of liberation of the antidiuretic hormone in a10 to 15 kilo dog in the range of 0.001 to 0.005 unit per hour. PMID- 19871246 TI - QUANTITATIVE ALTERATIONS IN THE HYPEREMIA RESPONSES TO LOCAL ISCHEMIA OF THE SMALLEST BLOOD VESSELS OF THE HUMAN SKIN FOLLOWING SYSTEMIC ANOXEMIA, HYPERCAPNIA, ACIDOSIS, AND ALKALOSIS. AB - The responsiveness of the smallest blood vessels of the human skin was measured in systemic anoxemia, hypercapnia, acidosis, and alkalosis. A method was used which measured quantitatively the reactive hyperemia produced by a standardized period of local ischemia of these fine vessels. By timing the clearing period of the threshold hyperemia response a direct indication of blood flow in these fine vessels was obtained. The following conclusions were reached concerning the responses of the smallest blood vessels of the skin. 1. Systemic anoxemia causes a decrease in sensitivity to local ischemia and a slowing of the blood flow. 2. Hypercapnia prevents the changes resulting from anoxemia. 3. These changes in the smallest blood vessels of the skin occur independently of changes in pulse rate, blood pressure, and respiratory rate and depth. 4. With systemic acidosis there is a decrease in sensitivity to local ischemia and a slowing of blood flow. The exact opposite takes place in systemic alkalosis. 5. The view is advanced, after due consideration of the facts, that the carbon dioxide concentration of the blood, or something directly associated with it, is the most important factor determining the sensitivity of these vessels, rather than oxygen saturation or changes in blood pH. PMID- 19871247 TI - UNSATURATED FATTY ACIDS IN THE DIETARY DESTRUCTION OF N,N-DIMETHYLAMINOAZOBENZENE (BUTTER YELLOW) AND IN THE PRODUCTION OF ANEMIA IN RATS. AB - Crude linoleic acid incorporated with or without butter yellow in a synthetic diet proved to be toxic for rats. The toxic effect manifested itself in loss of weight, progressive anemia of the secondary type, leucopenia, and pediculosis. It could be neutralized preventively and therapeutically by administration of yeast. The toxicity of the diet containing linoleic acid appears to be due to oxidative break-down products of the unsaturated fatty acid. The color of the same diet when it contained crude linoleic acid supplemented with butter yellow faded progressively in the presence of air (O(2)), even at room temperature. Purified preparations of linoleic acid and, to a less degree, purified preparations of arachidonic and oleic acids have shown the same destructive effect on butter yellow in vitro. Brown (unpolished) or white rice contains a stabilizer (antioxidant) for the preservation of butter yellow. In experiments on the production of hepatoma in rats following the ingestion of butter yellow, rice on one hand and crisco or butter fat on the other hand have proved to be procarcinogenic. These results would seem to be correlated with the preservation of butter yellow in the diet and in the intestine, because of the antioxidant in rice and the low supply of unsaturated fatty acids,respectively. PMID- 19871248 TI - LIVER INJURY, LIVER PROTECTION, AND SULFUR METABOLISM : METHIONINE PROTECTS AGAINST CHLOROFORM LIVER INJURY EVEN WHEN GIVEN AFTER ANESTHESIA. AB - Protein-depleted dogs are very susceptible to injurious agents-in particular, chloroform. Methionine given shortly before chloroform anesthesia will give complete protection against chloroform. Methionine (or cysteine plus choline) given 3 or 4 hours after chloroform anesthesia will give significant protection against the liver injury of chloroform anesthesia. Methionine given more than 4 hours after chloroform anesthesia gives no protection against liver injury. Choline alone given before chloroform gives no protection against liver injury. The protein-depleted dogs have livers which are deficient in both nitrogen and sulfur, but sulfur is depleted more than is the nitrogen. The N/S ratio therefore rises. Methionine or cystine feeding promptly makes up this liver sulfur deficit. Viable liver cells are necessary for this uptake of sulfur. Livers of fetuses in utero or of newborn pups tolerate a chloroform anesthesia which will cause fatal liver injury in adults. The nitrogen and sulfur values of these fetus or pup livers are within the high normal values for adults. Blood-forming cells are present in the fetus or pup livers during this period. When these blood islands are eliminated during the 3rd or 4th week of life, the liver then becomes normally susceptible to chloroform liver injury. Methionine or methionine-rich protein digests (e.g. casein) or various proteins by mouth or by vein should prove useful to protect the liver against certain types of injury and to aid in organ repair. PMID- 19871249 TI - SEROLOGICAL REACTIONS OF PROTEIN FILMS AND DENATURED PROTEINS. AB - Films of several proteins, hen ovalbumin, horse and human serum albumins, and globulins were found to combine specifically with antibodies, showing that the reactions can take place independently of the structure which secures the compact shape of the protein molecule. Serum globulin films differed from ovalbumin in that they lost their reactivity when kept on the water surface. Species specific reactions were observed with films of serum albumin and suitably diluted antisera, and likewise in the customary precipitin tests in which immune sera for denatured hen ovalbumin were tested against ovalbumin of other species. Specific fixation was also observed upon exposing monolayers of purified antibodies for pneumococci of Types I and III to the corresponding polysaccharides. PMID- 19871250 TI - QUANTITATIVE STUDIES OF THE PHOTOCHEMICAL DESPECIATION OF HORSE SERUM : AN APPROACH TO THE PROBLEM OF INTRAVENOUS FOREIGN PROTEIN THERAPY. AB - 1. Normal horse serum was irradiated for periods of 3 to 4 days, with visible light or with ultraviolet light of known intensity and wave length. The photosensitizer hematoporphyrin was employed in some instances. The serum was exposed to the air in thin layers, and thoroughly agitated throughout irradiation. 2. The irradiated sera were unchanged in color, and over 90 per cent of the original protein content remained precipitable by phosphotungstic acid. 3. Studies of the antigenicity of the sera were carried out on guinea pigs and rabbits. Fresh antigenicities of deviated specificity and of an activity of the order of 1/50th, 1/1,000th, and less than 1/20,000th that of normal horse serum were obtained. The residual content of material having the same antigenic specificity as normal horse serum was estimated as approximately equivalent in activity to dilutions of normal horse serum of 1 cc., 1/10 cc., and less than 1/100 cc. per litre respectively. PMID- 19871251 TI - THE IMMUNIZATION OF FOWLS AGAINST MOSQUITO-BORNE PLASMODIUM GALLINACEUM BY INJECTIONS OF SERUM AND OF INACTIVATED HOMOLOGOUS SPOROZOITES. AB - This paper reports attempts to immunize domestic fowls against mosquito-borne infections of Plasmodium gallinaceum by means of (a) vaccination with inactivated homologous sporozoites; (b) injections of sera, both normal sheep serum, and serum from fowls chronically infected with the homologous Plasmodium, (c) combinations of both sporozoite vaccine and serum. It was possible to reduce the normal malaria death rate (55.4 per cent) in these fowls by each of the above methods but most markedly by the combined prophylactic treatment. Mortality rates were 21.1 per cent in vaccinated fowls, 16.7 per cent in serum-treated fowls, and 7.3 in those having the combined treatment. Intensity of infection was measured by counting the percentage of red cells infected each day. It was found that in each group of fowls having prophylactic treatment the average of highest percentages of red cells infected was less than in untreated malarious fowls (30.1 per cent). The average figure was 20.5 per cent in vaccinated fowls, 17.9 per cent in those having serum injections, and 15.0 per cent in those having combined treatment. The prepatent period was not markedly affected by any of the prophylactic procedures. It averaged 9.1 days in the untreated group, 8.9 days in both the vaccinated and serum-treated groups, and 9.7 days in the group having combined treatment. The results seemed to demonstrate an interaction of both cellular and humoral agencies in defence against malaria, since the greatest immunizing effect was seen in the series having both sporozoite vaccine and serum injections. PMID- 19871252 TI - THE SPECIFIC POLYSACCHARIDE CONTENT OF PNEUMONIC SPUTA. AB - 1. The average specific polysaccharide content of rusty or bloody sputa in Type III was 91 times greater than the average for Types I, II, VII, and VIII pneumonia. 2. Those Type III sputums which were classified as reticulated contained an average S concentration of 1,360 mg. per cent or 170 times more than the amount found in other types. 3. Those Type III sputa which were classified as non-reticulated contained an average S concentration of 45 mg. per cent or 5.5 times more than the amount found in other types. 4. The amount of specific polysaccharide in the sputa of patients with Type III pneumonia furnishes an index to the severity of the disease and an aid in prognosis. PMID- 19871253 TI - THE SPECIFIC POLYSACCHARIDE CONTENT OF PNEUMONIC LUNGS. AB - 1. The specific polysaccharide content of pneumonic lungs in Type III pneumonia was 60 times greater than in Type I, II, VII, and VIII cases. 2. The highest values were obtained from gray hepatized lobes, but the red hepatized and edematous areas also contained large quantities of S. 3. Comparable yields of polysaccharide were recovered from the sputa and lungs of fatal cases. 4. Preliminary peptic digest of lung exudates increased the S yields. 5. The data support the hypothesis that the outcome in Type III pneumonia is related to the ability of the pneumococci to produce capsular polysaccharide. PMID- 19871254 TI - HYPOPROTEINEMIA AS PROTECTION AGAINST MERCURIC CHLORIDE INJURY IN DOGS. AB - Twelve control dogs receiving a single intravenous injection of mercuric chloride, 3.0 mg. per kg., all died within 4 to 11 days afterwards with marked nitrogen retention and extensive necrosis and calcification of the epithelium lining the proximal convoluted tubules. Three dogs of comparable age and weight were reduced to a standard hypoproteinemic state by repeated plasmapheresis. Each dog then received the same dose of mercuric chloride as the controls. None of these dogs became sick, none showed any elevation of non-protein nitrogen, and the kidneys- both in the gross and histologically-appeared normal when they were examined 8 to 45 days later. As tested thus far intensive plasmapheresis following the injection of mercuric chloride has been without effect in preventing the classical changes of mercuric chloride injury observed in the control dogs. The simplest explanation for these phenomena is that mercuric chloride acts on a more or less specific substance (presumably fabricated or concentrated in the renal cortex) which is depleted in the standard hypoproteinemic state. Other possibilities are mentioned. These findings are in sharp contrast to the results of similar experiments with uranium nitrate. The hypoproteinemic state appears to render the animals more susceptible to uranium injury (3). This probably indicates that the mode of action of the two heavy metals is different. PMID- 19871255 TI - LOW PROTEIN DIET AUGMENTS HYPERPROTEINEMIA PRODUCED BY REPEATED INJECTIONS OF HOMOLOGOUS PLASMA : EVIDENCE FOR A DYNAMIC EQUILIBRIUM BETWEEN FOOD, PLASMA, AND TISSUE PROTEINS. AB - 1. In 4 dogs maintained on a high protein diet (lean meat) repeated intravenous injections of plasma obtained from healthy donor dogs (18 to 24 injections during the course of 3 to 4 weeks, totalling 1595 to 4355 cc.-averaging 1800 cc. when figured on thc basis of a 5 kg. dog) resulted in a mean increase in the plasma protein concentration of 20 per cent (from 7.1 per cent to 8.5 per cent). 2. In 7 dogs maintained on a low protein diet (only 7 per cent of total caloric value derived from protein) almost identical injections of donor's plasma caused an average increase in the plasma protein concentration of 40 per cent (from 6.7 per cent to 9.4 per cent). 3. The albumin:globulin ratio in the group on the low protein diet showed an average fall of 30 per cent (from 1.4 to 0.9) while in the group on the high protein diet the change in this ratio was insignificant (from 1.3 to 1.2). 4. In all dogs in both groups there was a consistent fall in the hematocrit value of about 15 to 20 per cent (from 49 to 40, or 18 per cent) which can be explained in part at least by the increase in plasma volume of about 15 per cent. 5. There were no significant changes in body weight or in plasma N.P.N. PMID- 19871256 TI - COAGULATION AND LIQUEFACTION OF SEMEN : PROTEOLYTIC ENZYMES AND CITRATE IN PROSTATIC FLUID. AB - Certain specimens of human semen shorten the coagulation time of whole blood because of the presence of active thromboplastic agents, while other samples prolong its coagulation time. Human prostatic fluid in large amounts always delays or abolishes blood coagulation. The delay or absence of clotting is counteracted by adding calcium ions and is due to the large concentration of citrate in prostatic fluid and in some semens. While most specimens of dog semen shorten the coagulation time of blood because of their thromboplastic activity, certain specimens render blood incoagulable or delay coagulation; in contrast to human semen, this adverse effect on coagulation is not overcome with calcium ions and is due to a different mechanism, the lysis of fibrinogen. The citrate content of dog prostatic fluid is small. Human semen which has become liquefied does not contain thrombin or prothrombin, but fibrinogen and thromboplastic substances are present. Beef fibrinogen added to semen is destroyed by incubation for 18 hours, but added prothrombin and thromboplastic substances are still present after this treatment. Dog semen, in some instances, contains small amounts of thrombin. The semens of man and dog contain a fibrinolysin for human blood which seems not to differ greatly from the fibrinolysin associated with hemolytic streptococci. The blood of the donor of prostatic fluid is susceptible to fibrinolysis by this fluid. However, the blood of persons with some diseases, is absolutely resistant to the action of seminal fibrinolysin. In how many diseases this happens has not yet been determined. The semens of man and dog both contain an agent capable of inactivating fibrinogen, but in different amounts. This activity may be called fibrinogenase. Human semen is rich in fibrinolysin, poor in fibrinogenase; dog semen is rich in fibrinogenase, poor in fibrinolysin. These species differences, together with the fact that it is easy by appropriate dilution to retain the stronger proteolytic agent and eliminate the weaker one, imply that fibrinolysin and fibrinogenase are different entities. Dog semen, and less constantly human semen, contain very small amounts of trypsin. All of these proteolytic agents derive from the prostate gland; their secretion in prostatic fluid constitutes a hitherto undescribed function for the prostate gland. PMID- 19871257 TI - A NATURAL ANTIBODY THAT REACTS IN VITRO WITH A SEDIMENTABLE CONSTITUENT OF NORMAL TISSUE CELLS : I. DEMONSTRATION OF THE PHENOMENON. AB - The foregoing experiments have shown that complement fixation takes place when the blood serum of normal adult rabbits is mixed with fresh saline extracts of normal rabbit tissues under controlled conditions. A natural antibody, which reacts in vitro with a sedimentable constituent of normal tissue cells, is responsible for the phenomenon. PMID- 19871258 TI - A NATURAL ANTIBODY THAT REACTS IN VITRO WITH A SEDIMENTABLE CONSTITUENT OF NORMAL TISSUE CELLS : II. SPECIFICITY OF THE PHENOMENON: GENERAL DISCUSSION. AB - Continued serological investigations of the sedimentable constituents of normal and neoplastic tissues have shown that the blood serum of normal rabbits will fix complement in mixture with saline extracts of normal rabbit tissues. The phenomenon has proved referable, not to anticomplementary effects of serum or antigen nor to so called non-specific complement fixation, but to a naturally occurring serum principle, hitherto unrecognized, which reacts specifically in vitro with a sedimentable constituent of normal tissue cells. The principle exists in the blood of nearly all adult rabbits but is absent from that of rabbits less than 1 month old. It can be salted out from serum with ammonium sulfate and is destroyed when heated at 65 degrees C. for 20 to 30 minutes. Its titer was found to run parallel in general with that of two natural antibodies also present in normal rabbit's blood (natural Wassermann reagin, natural anti sheep hemolysin); but absorption tests showed it to be distinct from these. Because of its properties, the serum principle has been termed the natural tissue antibody. The substance with which the natural tissue antibody reacts is regularly present in saline extracts of many normal tissues,-those of rabbits and of other species as well. Kidney and liver tissues always yield it in abundance, while spleen, brain, and testicle provide somewhat less; heart and voluntary muscle extracts contain relatively little, and non-nucleated erythrocytes and skin are practically devoid of it. The results of affinity and absorption tests indicate that it is nearly or quite the same from whatever tissue or species derived. It is readily sedimentable in the high-speed centrifuge, little or none remaining in the supernatant liquid of potent suspensions spun at 25,000 R.P.M. (45,400 g) for 1 hour. It either does not come away into alcohol or is inactivated thereby, is readily destroyed by heat (56-70 degrees C. for 30 minutes), and diminishes notably in antigenic potency upon standing overnight in saline suspension or when the tissues containing it are kept in glycerol. Its properties suggest that it may be a protein. The implications of the findings are discussed in relation to the formation of the natural antibody and its place amongst serological phenomena, to so called "non-specific" fixation of complement and other serological complexities, and with particular reference to the character of the sedimentable constituents of normal and neoplastic tissue cells. PMID- 19871259 TI - THE METABOLISM OF THE CENTRAL NERVOUS SYSTEM IN EXPERIMENTAL POLIOMYELITIS. AB - 1. During paralysis, the brain of the mouse infected with poliomyelitis virus shows on test after mincing a decrease in anaerobic glycolysis with no significant change in oxygen utilization. The decrease in anaerobic glycolysis varies from 5 per cent to 50 per cent. 2. Sodium fluoride produces a greater inhibition of anaerobic glycolysis in normal than in poliomyelitic brain. 3. Dehydrogenase activity is higher for poliomyelitis-infected brain without added substrate. This difference from normal disappears when substrates are added. 4. The ratio of See PDF for Equation for the sliced motor cortex is higher than for sliced visual cortex of the dog and cat. 5. The oxygen consumption of the anterior horn of the sliced spinal cord of dog and cat is much less than that of the cerebral cortex. 6. The findings are in keeping with the view that, at a certain stage of the infection, the nerve cells may be reversibly injured but not yet destroyed by the virus. PMID- 19871260 TI - STUDIES ON HYPOALBUMINEMIA PRODUCED BY PROTEIN-DEFICIENT DIETS : III. THE CORRECTION OF HYPOALBUMINEMIA IN DOGS BY MEANS OF LARGE PLASMA TRANSFUSIONS. AB - 1. It proved possible to correct dietary hypoalbuminemia in dogs by large plasma transfusions (about 50 cc. per kilo per day). After 1 week of injections the increase of plasma protein exceeded the normal level although but 10 to 13 per cent of the injected protein remained in the blood. There was an associated increase in plasma volume and a marked diuresis. During the following 2 weeks the plasma volume and protein returned to their previous low levels. 2. The nitrogen introduced was retained and produced no change in urinary excretion during the week of plasma injections, but in the following 2 weeks there was an increased nitrogen output. The inference would seem to be that the large amounts of plasma injected in these experiments were not permanently utilized by the body as nitrogenous nourishment but after some delay were largely excreted in the urine. PMID- 19871261 TI - THE OCCURRENCE OF MUCOID POLYSACCHARIDE IN HEMOLYTIC STREPTOCOCCI OF HUMAN ORIGIN. AB - 1. A rapid method for the roughly quantitative estimation of mucoid polysaccharide in hemolytic streptococci has been described. 2. Using this method, about 94 per cent of strains from moderate or severe streptococcal infections in man have been found to produce mucoid polysaccharide in greater or less amount. In a group of streptococci from normal throats only about 8 per cent produced this substance, all of the producers falling into Lancefield's group A. 3. Of the Lancefield group A strains from both normal and infected sources, 92 per cent showed the presence of mucoid polysaccharide in culture dilutions of 1:10 or higher. 4. The probable significance of the mucoid polysaccharide in streptococcal virulence is indicated. PMID- 19871262 TI - QUANTITATIVE STUDIES OF SULFONAMIDE RESISTANCE. AB - 1. In vitro experiments were performed with E. coli, using a method designed for the quantitative study of various aspects of sulfonamide resistance. 2. Resistance was found to be a gradually developing process, and was demonstrated for all four drugs tested, sulfanilamide, sulfapyridine, sulfathiazole, and sulfadiazine. 3. It was shown that the degree of resistance developed was correlated with the bacteriostatic potency of the sulfonamides, and that organisms resistant to certain bacteriostatic concentrations of one sulfonamide were equally resistant to similar bacteriostatic concentrations of the other sulfonamides. 4. These observations were interpreted as indicating that the development of sulfonamide resistance represents an interaction between the organisms and the one common structural unit of all the sulfonamides, namely, the p-amino nucleus. It is also suggested that this interaction may involve the same enzyme system (or systems) as those concerned in the antagonism of the sulfonamides by para-aminobenzoic acid. 5. The relation of these findings to the broader aspects of sulfonamide resistance is discussed, and it is postulated that, despite reports to the contrary, all organisms susceptible to the bacteriostatic action of the sulfonamides are capable of becoming resistant to all of the sulfonamides. PMID- 19871263 TI - THE VIRUS OF INFECTIOUS FELINE AGRANULOCYTOSIS : I. CHARACTERS OF THE VIRUS: PATHOGENICITY. AB - Thirty-two strains of an infectious filterable agent, with properties that establish it as a virus, have been isolated from a malady of cats. This disease can be readily recognized and differentiated from other feline diseases by blood studies, which make apparent the characteristic profound leucopenia and marked relative lymphocytosis in the absence of thrombopenia and appreciable anemia. (Because the cytological pictures of the bone marrow and blood are essentially similar to those which characterize human agranulocytosis, we have named the disease under study "infectious feline agranulocytosis.") The cytological reaction to the presence of the virus is further characterized by proliferation of the reticuloendothelial cells of the lymph nodes and spleen, and by the formation of intranuclear inclusion bodies in the cells of the gastro-intestinal mucosa, lymph nodes, and bronchial mucosa. The etiological agent, the virus of infectious feline agranulocytosis, is pathogenic for cats when given by the oral, intragastric, cutaneous, subcutaneous, intraperitoneal, intravenous, and intranasal routes; it can be recovered at the height of the disease from the blood, spleen, liver, lung, intestinal mucosa, nasal secretions, nasal mucosa and turbinates, feces, and urine. The virus appears to be limited in its pathogenicity to the feline species. We found that a variety of animals, as represented by albino Swiss mice, guinea pigs, domestic rabbits, and ground squirrels (Citellus richardsonii Sabine), failed entirely to react to the injection of massive doses of virus. Repeated attempts at infection of these animals regularly failed when the intranasal, intraperitoneal, subcutaneous, and intramuscular routes of inoculation were employed for single doses. The same was true when from four to six transfers in "blind" serial tissue passages were made. Moreover, attempts to propagate the virus on the chorio-allantoic membrane of the developing chick were unsuccessful. The significance of the facts is discussed in the paper that follows. PMID- 19871264 TI - THE VIRUS OF INFECTIOUS FELINE AGRANULOCYTOSIS : II. IMMUNOLOGICAL RELATION TO OTHER VIRUSES. AB - The infection of cats by the virus of infectious feline agranulocytosis is followed by the production of specific neutralizing and protective antibodies, and recovery from the disease is associated with the development of solid immunity to reinfection. From the evidence presented it is obvious that the virus is not related to the viruses of hog cholera, lymphocytic choriomeningitis, fox encephalitis, vesicular stomatitis, the Western type of equine encephalomyelitis, herpes, and B virus infection. PMID- 19871265 TI - STUDIES CONCERNING THE SITE OF RENIN FORMATION IN THE KIDNEY : IV. THE RENIN CONTENT OF THE MAMMALIAN KIDNEY FOLLOWING SPECIFIC NECROSIS OF PROXIMAL CONVOLUTED TUBULAR EPITHELIUM. AB - 1. The administration of tartrate to adult rabbits was found to produce in some of them, a profound and widespread necrosis of the proximal convoluted tubular epithelium without affecting the other portions of the nephrons. 2. The markedly damaged kidneys were found to be almost completely devoid of pressor substance (renin), indicating that in the mammalian kidney, the epithelium of the proximal convoluted tubules is concerned in the formation or storage of renin. PMID- 19871266 TI - SYNERGISTIC ACTION OF HEMOPHILUS INFLUENZAE SUIS AND THE SWINE INFLUENZA VIRUS ON THE CHICK EMBRYO. AB - The synergistic effect of Hemophilus influenzae suis and swine influenza virus in the pig can be reproduced by the inoculation of these agents on the chorioallantoic membrane of 9 to 10 day old chick embryos. Two strains of human influenza virus that were studied failed to substitute for the swine virus in the synergistic reaction. No loss of synergistic effect was noted when the swine influenza virus was put through 11 chick embryo passages. Recently isolated and old stock strains of Hemophilus were equally able to enhance the effect of the virus. Heat-killed cultures of H. influenzae suis can be substituted for the bacterial component of the reaction. Infection of the embryo with swine influenza virus predisposes to infection with H. influenzae suis. The combination of H. influenzae suis and swine influenza virus causes a selective destruction of the embryo lungs, not produced by the individual components. This pneumonia exhibits the essential features of the natural disease. PMID- 19871267 TI - EPIDEMIC KERATOCONJUNCTIVITIS : I. ISOLATION AND IDENTIFICATION OF A FILTERABLE VIRUS. AB - 1. A virus has been isolated from two patients suffering with epidemic keratoconjunctivitis. 2. At first the virus could be maintained only by the inoculation of tissue cultures (serum ultrafiltrate and embryonic mouse brain) with conjunctival scrapings or with emulsified mouse brains from early passage animals. Later it caused a fatal disease in every mouse into which it was inoculated, and could, then be readily maintained in mice. 3. The virus proved pathogenic for unweaned white Swiss mice by the intranasal, intraperitoneal, and intracerebral routes; for adult mice by the intranasal and intracerebral routes, and for rabbits by only the intracerebral route. 4. Although the titer of tissue cultures rarely exceeded 10(-2) or 10(-3), the virus, once established in mice, increased in potency until titers of 10(-5) and 10(-6) were attained. Mice injected with either the emulsion of mouse brain tissue or with the tissue culture material in these dilutions developed symptoms within a definite incubation period; once the disease was initiated, it followed a characteristic course for a period of a few to 24 hours, and consistently terminated in death. 5. The pathological changes in mice were limited to the central nervous system, and were not particularly distinctive. The neurotropic character of the virus is further shown by the fact that only the brain tissue was consistently pathogenic for mice. 6. Serial tissue cultures could be maintained only at room temperature, and when the inoculum from virus-infected cultures into fresh tissue cultures contained ground-up cells. 7. The highest level of potency in cultures occurred on about the 6th day at room temperature. 8. The virus passed without difficulty through an E-K Seitz filter (double pads) and through all grades of Berkefeld filters. 9. The virus passed consistently through graded collodion membranes with an A.P.D. of 75 to 100 millimicrons and to a lesser extent through those with an A.P.D. of 50 to 75 millimicrons. Membranes with an A.P.D. of less than 50 millimicrons retained the virus. 10. The mouse virus was not neutralized by anti lymphocytic choriomeningitis serum, antiherpes serum, normal human serum, or serum from cases of non-specific conjunctivitis or keratitis. 11. Mice hyperimmunized to Theiler's virus were susceptible to the mouse keratoconjunctivitis virus. The latter virus was also not neutralized by hyperimmune Theiler rabbit serum. 12. The mouse virus could be neutralized by serum from the two patients from whom the virus had been isolated, and also by that from the three patients convalescing from epidemic keratoconjunctivitis in California and the serum of a convalescent in New York. The neutralization data were confirmed by tests on 15 additional convalescent serums (unpublished data). 13. A mild but characteristic picture of epidemic keratoconjunctivitis was reproduced in a human volunteer following inoculation with the mouse virus. 14. The serum of the human volunteer, while not neutralizing the mouse virus before infection, contained neutralizing antibodies 1 month after infection. 15. Development of antibodies was demonstrated in one patient (R.H.) in the present series, and in six other patients of another series (unpublished data). PMID- 19871268 TI - THE SWINE LUNGWORM AS A RESERVOIR AND INTERMEDIATE HOST FOR SWINE INFLUENZA VIRUS : III. FACTORS INFLUENCING TRANSMISSION OF THE VIRUS AND THE PROVOCATION OF INFLUENZA. AB - 1. During a 3 year study of the lungworm as intermediate host for the swine influenza virus 98 transmission experiments, using 216 swine, have been conducted. Of these, 50 gave negative results. In the remaining 48, transmission of swine influenza virus by way of the lungworm was demonstrated in one or more animals of each experiment. Irregularities in the results would appear to be due not so much to lack of transmission of masked virus by the lungworms as to failure to evoke its pathogenic capabilities. 2. The stimulus of choice that was most successful in the provocation of swine influenza consisted of multiple intramuscular injections of H. influenzae suis. In several experiments pigs developed swine influenza virus infections 9 to 17 days after infestation with infected lungworms in the absence of any known provocative stress. In these instances an immune response of the swine to the lungworms themselves is suspected of having furnished the provocation. 3. During May, June, July, and August, swine prepared by the ingestion of lungworms carrying virus were absolutely refractory to the provocation of influenza, and they were relatively refractory in September and October. The masked virus was activated most readily during the first 4 months of the year. 4. In a single experiment we succeeded in demonstrating by direct means the presence of swine influenza virus in the neighborhood of lungworms at the base of the lung at a time when the virus was not demonstrable anywhere else in the respiratory tract. 5. Masked swine influenza virus was found to be present in lungworm ova obtained either from the respiratory tracts or the feces of infected swine. 6. In a number of instances, masked swine influenza virus has been found to persist for over a year in lungworm larvae within the earthworm intermediate hosts, and in one case its presence was demonstrated after 32 months. 7. Two varieties of a single species of earthworm, namely, Allolobophora caliginosa f. typica (Savigny) and A. caliginosa f. trapezoides (Duges), have been found separately capable of serving as intermediate hosts for virus-infected lungworms. 8. Lungworm ova, obtained from convalescent swine which are no longer carrying swine influenza virus in infectious form in their respiratory tracts, contain masked virus. PMID- 19871269 TI - THE SWINE LUNGWORM AS A RESERVOIR AND INTERMEDIATE HOST FOR SWINE INFLUENZA VIRUS : IV. THE DEMONSTRATION OF MASKED SWINE INFLUENZA VIRUS IN LUNGWORM LARVAE AND SWINE UNDER NATURAL CONDITIONS. AB - 1. The presence of masked swine influenza virus has been demonstrated in lungworm larvae from earthworms dug on Midwestern farms. 2. Swine influenza virus infections were provoked in 2 of 3 swine obtained from an Iowa farm during an interepizootic period. 3. The evidence presented has been interpreted as indicating that the swine lungworm is the reservoir and intermediate host for swine influenza virus in the field. 4. A concept of the epidemiology of swine influenza in which the causative virus is represented as being maintained and disseminated in a masked form by its lungworm intermediate host has been presented. PMID- 19871270 TI - COMPLEMENT FIXATION WITH THE NEUROTROPIC VIRUSES. AB - Antigens capable of fixing complement specifically with the appropriate antibodies have been prepared from brain tissue of hamsters and mice infected with the viruses of St. Louis, Japanese, Western, and Eastern encephalitis, and with the West Nile virus. The antigens were freed of the material which reacts with normal serum by means of centrifugation at relatively high speed. In addition, the infectivity of the preparation was destroyed by irradiation with ultraviolet light. Cross reactions were demonstrated by means of the complement fixation technique with materials from animals infected with the viruses of Eastern and Western equine encephalitis. No relationship was detectable by this procedure between St. Louis, Japanese, and West Nile viruses. These findings emphasize the need for further investigation and correlation of the immunological reactions of the groups of neurotropic viruses, since the equine agents are apparently unrelated when studied by neutralization and cross-immunity tests while these methods provide evidence of the presence of common antigenic structures in the St. Louis, Japanese, and West Nile agents. PMID- 19871271 TI - THE LS-ANTIGEN OF VACCINIA : III. PHYSICAL-CHEMICAL PROPERTIES OF LS-ANTIGEN AND SOME OF ITS DEGRADATION PRODUCTS. AB - Studies on LS-protein, the soluble double antigen of vaccinia, and on the degradation products L'S and L''S' have been made with electrophoresis and in the analytical ultracentrifuge. LS, which is homogeneous electrically and in the ultracentrifuge, has an isoelectric point at pH 4.8. At 4 degrees C. its partial specific volume is 0.72 cc./gm., and its diffusion constant is 1.50 x 10(-7) cm.(2)/sec. The sedimentation constant is 6.35 at 20 degrees C., the molecular weight is 214,000, and the molecule appears to have an elongated ellipsoidal shape with an axis ratio of 1:20. L'S and L''S' are homogeneous electrically but not in the ultracentrifuge, L''S' being extremely polydisperse. PMID- 19871272 TI - THE LS-ANTIGEN OF VACCINIA : IV. CHEMICAL ANALYSIS OF LS AND THE EFFECT OF CHYMOTRYPSIN ON LS. AB - Pure LS-antigen of vaccinia contains 15.8 per cent N and 50.6 per cent C. These analytical data together with the absence of lipids, phosphorus, nucleic acid, and glucosamine in preparations of the antigen confirm the protein nature of the substance. The action of proteolytic enzymes on LS offers further confirmation of the protein character of the antigen. Both the L- and S-activities of the antigen are destroyed by digestion with papain. The effects of crystalline chymotrypsin on LS-antigen are particularly interesting for, under proper conditions, this enzyme destroys the serological activity of the S-portion of the molecule without affecting the L-portion. This newly prepared degradation product of LS, called LS'', contains the same amount of N as the native substance but unlike LS, it forms needle-shaped crystalloids. PMID- 19871273 TI - THE EFFECT OF SALICYLATES ON THE PRECIPITATION OF ANTIGEN WITH ANTIBODY. AB - 1. Sodium salicylate modifies the precipitation of normal rabbit serum protein by sodium tungstate, and partially inhibits the precipitation of horse serum euglobulin by rabbit antiserum. Sodium salicylate added to a system containing crystalline egg albumin and its antibody partly prevents the formation of precipitate, the degree of inhibition being related to the concentration of salicylate. 2. Precipitation in the equivalence zone is more readily prevented by salicylate than precipitation in the region of antibody excess, the immune system becoming progressively less sensitive to the action of salicylate as the excess of antibody becomes larger. 3. Formed precipitates were partly dissolved following resuspension in the presence of salicylate. 4. The salicylate effect on immune precipitation is reversible, and appears to be due to inactivation of antibody. 5. Salicylate was more effective in preventing specific precipitation than other anions of a lyotropic series tested. PMID- 19871274 TI - ALLERGENIC RELATIONSHIP OF THE POLLENS OF DWARF AND GIANT RAGWEED TO SEVERAL OF THEIR BOTANIC RELATIVES. AB - Thirty-eight of forty patients, allergic to the pollen of dwarf and giant ragweed, were found to be allergic also to the pollen of botanically related species. There was definite variation in the degree of reactivity to the various pollens in different patients. One additional patient reacted to dwarf ragweed but not to giant ragweed or to four other composites. Antibody neutralization studies in six cases indicated that (a) in four cases dwarf ragweed could have been the only sensitizing allergen. (b) In one case either dwarf or giant ragweed could have been the only sensitizing allergen. (c) In one case cosmos plus either of the ragweeds or some undetermined pollen could have been the sensitizing allergen, (d) In none of the six cases studied could cosmos, sunflower, goldenrod, or dandelion have been the only sensitizing allergens. The evidence presented supports the following concepts: (1) Hypersensitiveness of this type develops as the result of allergenic stimulation. (2) The pollens of the ragweeds and their botanic relatives contain, in addition to species-specific allergens, multiple common allergenic determinants which vary in their distribution among related species. (3) A person exposed simultaneously to a group of allergens may become sensitized to certain members of the group and not to others, while another person, exposed to the same group of allergens, may become sensitized to different members of the group. PMID- 19871275 TI - AN IMMUNOLOGICAL AND ELECTROPHORETIC COMPARISON OF THE ANTIBODY TO C POLYSACCHARIDE AND THE C-REACTIVE PROTEIN OF ACUTE PHASE SERUM. AB - 1. Studies of the precipitation reaction of C polysaccharide with C protein, and of C polysaccharide with C antibody are reported. The similarity between these two systems in this respect is demonstrated. 2. The differences between C protein and C antibody are emphasized. The differences between this protein and antibodies in general have been reported previously by others. 3. Electrophoretic studies show that C antibody is in the gamma globulin fraction of serum whereas C protein migrates with the alpha(1) globulin fraction of acute phase protein. PMID- 19871276 TI - THE ULTRACENTRIFUGE AS AN AID IN THE DETECTION OF POLIOMYELITIS VIRUS. AB - 1. By means of differential ultracentrifugation, a purified and concentrated macromolecular fraction has been regularly obtained from infected human, monkey, and chimpanzee stools. This fraction was isolated from sixteen stools in which virus was thought to be present, and inoculated intracerebrally into sixteen monkeys, of which fifteen developed poliomyelitis. 2. Eleven stool specimens in which virus was suspected, when tested separately in eleven monkeys by the intra abdominal-intranasal method, produced poliomyelitis in two of these animals. When the same specimens were tested separately by the ultracentrifugal-intracerebral method, poliomyelitis developed in ten monkeys out of eleven inoculated. 3. With the intra-abdominal-intranasal method, it has been customary to inoculate the virus present in 1.6 gm. of stool. With the ultracentrifugal-intracerebral method, the virus present in as much as 30 gm. of stool has been inoculated. 4. From one titration experiment it would appear that the ultracentrifugal intracerebral method is at least 100 times more sensitive than the intra abdominal-intranasal method. PMID- 19871277 TI - THE DISTRIBUTION OF WATER AND ELECTROLYTES BETWEEN BLOOD AND SKELETAL MUSCLE IN EXPERIMENTAL HYPERTENSION. AB - THE EFFECT OF AN ABNORMAL RENAL CIRCULATION AND A RESULTING HYPERTENSION ON THE DISTRIBUTION OF WATER AND ELECTROLYTES IN SKELETAL MUSCLE OF DOGS WAS AS FOLLOWS: (1) By analysis of the muscle the total content of sodium and chloride was found increased and the total potassium content decreased. (2) A redistribution of water occurred in the muscle involving a shift of water from the muscle cells to the extracellular phase. The calculated mean values per kilo of muscle were, extracellular phase (F) = 254, +/- 54 gm.; intracellular water (H(2)O)(C) = 532, +/- 47 gm., and total solids (S) = 214, +/- 8 gm. This extracellular phase volume of 254 gm. represents an increase of 65 per cent over that found in normal dog muscle. After subjecting the hypertensive dogs to large increases in total body water produced by the intravenous injection of normal isotonic salt solution, the total bulk of 1 kilo of muscle increased a mean average of 103 gm. of which one half was attributed to the extracellular phase and the other half to the swelling of the muscle cells. Whether the changes found in this study are the result of the functional disturbances caused by the experimental renal abnormalities, or the hypertension, or a combination of both is uncertain at this time. The significance of the results is that there is quantitative evidence that a redistribution of water has occurred in skeletal muscle so that a real extracellular edema exists. PMID- 19871278 TI - THE STATE OF THE VESSELS OF THE MESENTERY IN SHOCK PRODUCED BY CONSTRICTING THE LIMBS AND THE BEHAVIOR OF THE VESSELS FOLLOWING HEMORRHAGE. AB - 1. Direct observations of the arteries, arterioles, capillaries, veins, and lymphatics in the mesentery of anesthetized cats put into shock by incomplete occlusion of the circulation of the limbs showed that: (a) Marked constriction of the arteries and arterioles, produced by muscular contraction, occurred usually within an hour after incomplete occlusion of the limbs, lasted several hours, and finally gave way in most instances to relaxation an hour or more before death. The constriction reduced the blood supply to the mesentery and intestine and the venous return from them. It did not, however, interrupt the blood flow. No pooling or stagnation of blood was seen even as a terminal phenomenon. (b) The veins of the mesentery also became constricted but showed less tendency to dilate as death approached. The lymphatics likewise became somewhat narrowed. Even during the terminal stage the leukocytes moved along without change in shape or sticking to the walls of the capillaries or venules. (c) Hematocrit determinations showed progressive hemoconcentration of moderate degree. (d) Autopsy usually showed the presence of small hemorrhages in many parts of the body, especially the heart, liver, spleen, and lungs. (e) Bilateral nephrectomy, suprarenalectomy, and pancreatectomy did not significantly alter the morphological picture elicited by shock induced by restriction of the circulation to the limbs. 2. Removal of large amounts of blood was always followed within a short time by constriction of arteries, arterioles, veins, and lymphatics of the mesentery. 3. Fall in arterial pressure produced by pithing was not accompanied by change in diameter of the arteries, arterioles, veins, or lymphatics, or by blanching of the mesentery or gut. PMID- 19871279 TI - ORAL PAPILLOMATOSIS OF RABBITS: A VIRUS DISEASE. AB - Papillomas occur frequently on the oral mucosa of domestic rabbits procured in the metropolitan area of New York. They are small and benign, and are situated mostly on the under side of the tongue. A filtrable virus can be extracted from them with which growths can be reproduced in the oral mucosa of several species of rabbits and hares but which fails to cause lesions when inoculated into other rabbit tissues and into the oral mucosa of other species. The virus differs notably from the Shope virus, which causes cutaneous papillomas in rabbits but proves innocuous to oral mucosa: rabbits solidly immune to the oral papilloma virus are fully susceptible to the Shope virus and vice versa. The oral papillomas are not highly contagious, for susceptible animals kept in individual cages in the same rooms with others carrying the growths, fed the same kind of food, and cared for by the same attendants, do not "catch" them. They are found much more frequently in the offspring of dams that carry the growths than in those of mothers free from them, and the causative virus can be recovered from the mouth washings of rabbits having no growths. The observations indicate that the virus may be spread by transfer from the mother to the young during the period of suckling, and that it may lie latent in the mouth, doing no harm unless the mucous membrane is injured. The slight trauma occurring now and then when coarse foods are chewed may furnish the required tissue nidus under natural conditions, for papillomas occasionally appear after virus has been dropped into the mouths of uninoculated rabbits; but the more extensive injury and healing resulting from experimental tattoo inoculations proves regularly effective in this respect. Tar can also act as an efficient adjuvant to the virus, the incidence of "spontaneous" oral papillomas being much higher in domestic rabbits that had had the opportunity to lick tar from their ears and paws during long periods than in normal control animals. The virus is recoverable in quantity from the oral papillomas of tarred domestic rabbits, and the findings indicate that it is their essential cause, the tar acting merely to prepare the tissue for the virus' action. For the same tar does not elicit oral papillomas in wild cottontail rabbits, which do not carry the causative virus though fully susceptible to it. The implications of the findings are discussed. PMID- 19871280 TI - STUDIES ON THE NATURE OF THE VIRUS OF INFLUENZA : I. THE DISPERSION OF THE VIRUS OF INFLUENZA A IN TISSUE EMULSIONS AND IN EXTRA-EMBRYONIC FLUIDS OF THE CHICK. AB - A considerable fraction of the influenza A virus contained in infected allantoic fluid of the developing chick is not sedimentable under conditions which remove virus activity almost completely from filtrates of emulsified mouse lung. The infectious unit from tissue suspensions is about 100 mmicro in diameter and is of the same chemical composition as particles of the same size and abundance separated from normal tissues by an identical procedure. Evidence has been presented showing that the infectivity can be, and probably is, carried on such normal cell components as an adsorbate. Other non-infective particles such as erythrocytes may also become infectious units through adsorption of the virus. The virus occurs in allantoic fluid in two states of dispersion. A variable percentage is associated with particles considerably less than 100 mmicro in diameter, probably more nearly 10 mmicro, while the remainder is reversibly aggregated. Reversal to the more disperse state may be effected by dilution, sonic vibration, or moderate heat treatment. PMID- 19871281 TI - STUDIES ON THE NATURE OF THE VIRUS OF INFLUENZA : II. THE SIZE OF THE INFECTIOUS UNIT IN INFLUENZA A. AB - The pathogenic agent of influenza A has been sedimented from infected extra embryonic fluids of the developing chick, embryo by ultracentrifugation. Material so obtained contains two fractions resolvable in the analytical centrifuge cell. The first, a homogeneous fraction, showed a sedimentation constant S(20) = 20 to 31 x 10(-13). The second showed a sedimentation constant S(20) = about 800 +/- 100 x 10(-13), was much less homogeneous than the first, and was shown to consist principally of aggregated particles of the more disperse fraction. Both fractions contained the virus in essentially equal amounts per unit of protein weight as calculated from nitrogen determinations. Electron micrographs of the isolated virus protein indicated that the predominating unit is roughly spherical in shape and has a modal particle diameter of about 11 mmicro, in good agreement with the sedimentation data in indicating a molecular weight of about 650,000. Approximately 300 of the particles having molecular weight of 650,000 were present in the minimal dose producing infection in mice after nasal instillation. The influenza A virus may now be regarded as one of the smallest pathogenic agents thus far isolated. Preliminary analyses indicate that it is also one of the least complex, being composed principally of nucleoprotein. PMID- 19871282 TI - TEN AMINO ACIDS ESSENTIAL FOR PLASMA PROTEIN PRODUCTION EFFECTIVE ORALLY OR INTRAVENOUSLY. AB - When blood plasma proteins are depleted by bleeding with return of the washed red cells (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet protein intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and to certain intoxications. When the protein intake of such dogs is completely replaced by the growth mixture (Rose) of crystalline amino acids, plasma protein production is excellent, weight and nitrogen balance are maintained. This growth mixture consists of ten amino acids, threonine, valine, leucine, isoleucine, tryptophane, lysine, phenylalanine, methionine, histidine, arginine, and is as effective as most diet proteins in plasma protein production. The above amino acid mixture in aqueous solution may be given by vein with equally good plasma protein production and no apparent clinical disturbance even when given rapidly. Cystine may replace methionine in the above mixture with equally good plasma protein production for 7 to 10 days but at the expense of the body tissues, that is, with weight loss and a negative nitrogen balance. The addition of cystine to the protein-free, otherwise adequate diet may result in the production of considerable new plasma protein during a period as long as 1 week (cystine effect). This reaction may depend upon the amino acid constitution of the preceding diet protein in that it occurred following a liver feeding but did not occur after pancreas feeding. Arginine is required in the diet of the protein depleted dog for fabrication of plasma protein. It is apparently not needed for nitrogen balance for as long as 1 or 2 weeks. The omission of either threonine or valine from the growth mixture is quickly followed by a sharp decline in plasma protein formation and by a negative nitrogen balance. When histidine, arginine, and most of the lysine are omitted from the growth mixture, nitrogen balance and weight may be maintained for as long as 1 week but plasma protein production falls off markedly. The findings indicate that the growth mixture of amino acids should be a valuable addition to transfusion and infusion therapy in disease states associated with deficient nitrogen intake or tissue injury and accelerated nitrogen loss, including shock, burns, and major operative procedures. PMID- 19871283 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : XIX. THE PRODUCTION OF PERSISTENT HYPERTENSION IN SHEEP AND GOATS. AB - Persistent hypertension has been produced in the goat and sheep by constriction of the main renal arteries. The presence or absence of accompanying uremia depends upon the degree of constriction of the renal arteries. In both sheep and goat, constriction of one main renal artery also caused elevation of the blood pressure which tended to persist longer than in the dog. Excision of the one kidney with main renal artery constricted resulted in a prompt (24 hours) return of the blood pressure to normal. In the animals with hypertension of long duration but without renal excretory insufficiency, (the "benign" phase) no significant arterio- or arteriolosclerosis developed as a result of the hypertension alone. In the animals that had both hypertension and renal excretory insufficiency, (the "malignant" phase) the typical terminal arteriolar lesions developed in many organs. These lesions consisted of necrosis and fibrinoid degeneration of arterioles and necrotizing arteriolitis which should not be confused with arteriolosclerosis. The same humoral mechanism which is responsible for experimental renal hypertension in the dog and other animals also obtains in the pathogenesis of experimental renal hypertension in the sheep and goat. PMID- 19871284 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : XX. THE BIOASSAY OF RENIN. AB - A simple, rapid method for the bioassay of renin has been presented. Reliable and consistent results are obtained by this method whereby an arbitrary dog unit of renin has been established. The response of normal unanesthetized dogs to renin is independent of the body weight of dogs weighing between 10 and 25 kilos. An estimate of potency of renin per kilo of body weight of the test animals is therefore not only unnecessary but misleading. A dog unit of renin has been defined as that amount which raises the blood pressure at least 30 and not more than 35 mm. Hg within 3 minutes in at least three unanesthetized dogs. The potency is expressed as dog units of renin per cubic centimeter. The determination of the amount of renal substance represented by a cubic centimeter of extract and the number of dog units per cubic centimeter give an estimate of the yield of renin which can be expressed as dog units of renin per gram of original renal tissue. By determination of the number of dog units per cubic centimeter and the amount of nitrogen in milligrams per cubic centimeter in any renal extract the purity of the renin can be determined and expressed as dog units of renin per milligram N. The establishment of a standard method for the bioassay of renin is considered highly desirable and the method outlined in this paper is suggested for this purpose. PMID- 19871285 TI - MAMMALIAN RED CELLS AS A SOURCE OF "SMALL PARTICLES". AB - 1. Small particles essentially similar to those previously isolated from other tissues have been isolated from mammalian red blood cells (horse blood). 2. About one-third of the dry weight of the particles is lipids. 3. The particles produce hemolysins against the homologous erythrocytes when inoculated into a foreign species. 4. The fact that the particles can be isolated from mammalian red cells which do not contain visible granules is taken to indicate that some at least of the particles isolated from whole organs represent disintegrated "stroma." PMID- 19871286 TI - THE INACTIVATION OF THE VIRUS OF LYMPHOCYTIC CHORIOMENINGITIS BY SOAPS. AB - The capacities of certain compounds at pH 7.3-7.5 to inactivate the virus of lymphocytic choriomeningitis have been demonstrated. Among the more effective substances were the fatty acids chaulmoogric, linolic, linolenic, myristic, oleic, and ricinolic, and the detergents zephiran, duponol LS, and aerosol OT. Upon the oleic acid inactivation of the virus, studies have been made of such variables as pH, rate of inactivation, and relative amounts of virus and oleate for removal of the infectivity. The role of oxidation in the process was determined as negligible. Attempts to recover infectious virus from oleate inactivated mixtures have been unsuccessful. It has been found that neither oleate nor ether-inactivated virus was capable of producing immunity in mice under the experimental conditions in which untreated virus induced a moderate immunity. PMID- 19871287 TI - THE COURSE OF EXPERIMENTAL INFECTION OF THE CHICK EMBRYO WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS. AB - The titration curve for the virus of Eastern equine encephalomyelitis inoculated into the 10 day old chick embryo shows that the maximum increase in virus content continues until shortly before the generalized destruction of the embryo is apparent. This is followed by a stationary phase. Histological studies of infected embryos fail to demonstrate selective tissue destruction, and titrations show the virus to be distributed throughout the egg, although concentrated in the embryo. The chorioallantoic membrane gradually becomes increasingly resistant with age to both the Eastern and Western viruses. Increased resistance with age is also apparent in the hatched chick. These findings are based on the use of the chick embryo itself as the test animal to determine the 50 per cent mortality end point. The limits of accuracy of this method are defined. PMID- 19871288 TI - ISOLATION OF CHROMATIN THREADS FROM THE RESTING NUCLEUS OF LEUKEMIC CELLS. AB - 1. A method for the separation of chromatin threads from the resting nucleus of leukemic cells has been described. 2. The isolation of the chromatin strands was accomplished by purely mechanical means, and the separation, including extraction and purification in the centrifuge, required only about 1 hour. 3. Evidence is presented to show that the chromatin strands are morphologically related to the chromosomes, if not identical. 4. It seems probable that, by the present technique, chromatin strands can be obtained from different mammalian tissues for direct microscopical examination and biochemical analysis. PMID- 19871289 TI - MORPHOLOGICAL STRUCTURE OF RICKETTSIAE. AB - The morphological structures of the rickettsiae of epidemic and endemic typhus fever, Rocky Mountain spotted fever, and Q fever are similar to one another and to certain bacteria. The rickettsial organisms in common with the elementary bodies of vaccinia virus and all bacteria would appear to have a limiting membrane which surrounds a substance that seems to be protoplasmic in nature; numbers of dense granules are embedded in the inner protoplasm. PMID- 19871290 TI - INDUCED RESISTANCE OF THE CENTRAL NERVOUS SYSTEM TO EXPERIMENTAL INFECTION WITH EQUINE ENCEPHALOMYELITIS VIRUS : II. SEROTHERAPY IN WESTERN VIRUS INFECTION. AB - Under none of the experimental conditions here described was treatment of the infection induced by the virus of Western equine encephalomyelitis in mice and guinea pigs with specific hyperimmune rabbit serum effective if begun after the onset of signs of encephalitis. In mice, after intracerebral inoculation of virus, serum was ineffective when given even before that stage. After peripheral introduction of virus in guinea pigs the disease was completely arrested in certain animals by single or multiple doses of antiserum if treatment was begun within 24 to 48 hours after virus inoculation. In others the incubation period was prolonged to 2 or even as long as 7 weeks. In untreated guinea pigs, injection of virus alone led to active immunity in those which survived. Antiserum blocked the antigenicity of active virus in the serum-treated animals. The decrease in titer in the sera of all antiserum-treated animals proceeded at the same rate as in those of control guinea pigs which received antiserum alone. Thus it was not possible to predict which ones would survive and which would succumb after a prolonged incubation period. Delayed fatal disease occurred at a time when the neutralizing antibody of the treated guinea pigs had fallen to a low titer. It is therefore likely that the virus which persisted throughout this long incubation period had been prevented from passing to and infecting other cells but reached them when antibody fell to an ineffective level in the surrounding medium. The relative frequency of such delayed reactions limits to a further extent the degree to which antiserum can be depended on for effective treatment of infection with the virus of equine encephalomyelitis. PMID- 19871291 TI - HEMOGLOBIN AND PLASMA PROTEIN : SIMULTANEOUS PRODUCTION DURING CONTINUED BLEEDING AS INFLUENCED BY AMINO ACIDS, PLASMA, HEMOGLOBIN, AND DIGESTS OF SERUM, HEMOGLOBIN, AND CASEIN. AB - Given healthy dogs, fed abundant iron and protein-free or low protein diets, with sustained anemia due to bleeding, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. The reserve stores of blood protein producing materials in this way are very largely depleted, and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for considerable periods of time. These dogs are very susceptible to infection and to injury by many poisons. Under such conditions, these anemic and hypoproteinemic dogs will use very efficiently a variety of digests (serum, hemoglobin, and casein) and the growth mixture (Rose) of pure amino acids. Nitrogen balance is maintained and considerable new blood proteins are produced. Dog plasma by vein is used freely in these doubly depleted dogs to make new hemoglobin in abundance (Table 1). Serum digests by vein are well utilized to make new hemoglobin and plasma protein in the same dogs (Table 1). Serum digests by mouth are effectively used to make new blood proteins (Table 5). Dog or sheep hemoglobin given in large amounts intraperitoneally are remarkably well utilized to form hemoglobin and plasma protein (Table 6). It must be obvious that the globin of the hemoglobin is saved in these protein-depleted dogs and used to make large amounts of hemoglobin and plasma protein. Hemoglobin digests are also well utilized whether given by mouth (Table 7) or by vein (Table 8) and liberal amounts of plasma protein are manufactured from digests presumably ideally suited for hemoglobin production. Casein digests are well used (Table 8) and form as much new plasma protein as any material tested-even serum digests. Amino acid mixtures are of especial interest. The growth mixture of 10 amino acids (Rose) is well utilized by mouth or by vein and favors new hemoglobin production more than any material tested (Table 2). Cystine replacing methionine in the amino acid mixture increases the plasma protein-hemoglobin output ratio, that is it favors plasma protein production. Digests of various sorts and amino acid mixtures or combinations of digests and amino acid mixtures can be used rapidly and effectively to build new hemoglobin or plasma protein, to maintain nitrogen equilibrium, and to replete reserve protein stores. These experiments point to clinical problems. The unexplained preference given to hemoglobin production in these hypoproteinemic dogs is observed under all conditions, even when whole plasma or serum digests are given by vein. In general, 2 to 4 gm. of hemoglobin are formed for every gram of plasma protein. This all adds up to a remarkable fluidity in the use of plasma protein or hemoglobin which can contribute directly to the body protein pool from which are evolved, without waste of nitrogen, the needed proteins, whether hemoglobin, plasma protein, or tissue proteins. PMID- 19871292 TI - BIOCHEMICAL STUDIES ON SHOCK : I. THE METABOLISM OF AMINO ACIDS AND CARBOHYDRATE DURING HEMORRHAGIC SHOCK IN THE RAT. AB - During and following the production of shock by hemorrhage in the normal, suprareno-demedullated, and suprarenalectomized rat, the following significant changes in amino acid and carbohydrate metabolism have been observed. 1. In the intact, suprareno-demedullated, and suprarenalectomized rat there is a progressive rise in the whole blood and plasma amino acid nitrogen levels during and after a fatal, shock-inducing hemorrhage. The rate of rise varies inversely with the survival time. In animals surviving the hemorrhage there is little or no elevation in whole blood amino acid levels during the 8 hours following hemorrhage, and a decrease in 24 hours due to hemodilution. The plasma amino acids, however, rise slightly. 2. The blood amino acid nitrogen elevation occurs only after the blood pressure has fallen to between 85 and 90 mm. of Hg. 3. The blood keto acids, as pyruvate, and the blood lactate become elevated during shock in the normal, suprareno-demedullated and suprarenalectomized rat. 4. In the normal fasted rat with low liver glycogen stores the blood sugar may rise moderately or may not rise at all during hemorrhagic shock. In animals with high liver glycogen levels (fed rats or fasted rats previously fed high protein diets) shock generally induces a marked hyperglycemia. In both groups hypoglycemia may occur terminally. 5. In the suprareno-demedullated and suprarenalectomized rats shock is always accompanied by a fall in the blood sugar. 6. There is no significant difference between the liver glycogen levels of suprareno demedullated rats fasted 48 hours and those similarly fasted but surviving 24 hours after a hemorrhage. The blood chemical changes have been interpreted as due to a decrease in hepatic function resulting from early anoxia of the liver and to the later effects of anoxia on the peripheral tissues causing an increased rate of protein breakdown and of glucose utilization and an accumulation of lactate and pyruvate in the blood and tissues. PMID- 19871293 TI - FURTHER STUDIES ON THE SURVIVAL AND DEVELOPMENT IN VITRO OF A MALARIAL PARASITE. AB - The survival of Plasmodium lophurae in vitro is favored by the presence of calcium pantothenate (0.02 mg. per ml). Survival of about 2 weeks in vitro at 40 41 degrees C. has been obtained under the following conditions: a medium consisting of duck red cell extract in balanced salt solution with glutathione and glucose or glycogen, serum, embryo extract, and calcium pantothenate; daily replacement of about half of the medium with fresh medium; addition of fresh uninfected erythrocytes every 2nd day; gentle agitation of the preparation on a rocking machine. In some of these preparations significant increases in male gametocytes and, more rarely, in total numbers of parasites occurred during the first few days. PMID- 19871294 TI - A METHOD FOR THE DETERMINATION OF THE BLUE DYE T-1824 IN PLASMA. AB - A method for the estimation of the concentration of the blue dye, T-1824, in plasma has been developed. The method is based on the fact that the dye can be reduced to a colorless compound by Na(2)S(2)O(4), in alkaline solution. The extinction coefficient is determined under specified conditions before and after reduction of the dye. Under the conditions employed hemoglobin does not interfere, even if partly present as HbCO or as methemoglobin; the absorption of light by the hemoglobin is the same before and after reduction of the dye. Absorption of light by suspended lipids and plasma pigments is also unaltered by the Na(2)S(2)O(4). Hence variations from sample to sample in hemolysis or degree of lipemia do not affect the accuracy with which T-1824 is determined. PMID- 19871295 TI - THE IMMUNOLOGICAL PROPERTIES OF THE HETEROPHILE ANTIGEN AND SOMATIC POLYSACCHARIDE OF PNEUMOCOCCUS. AB - 1. The lipocarbohydrate or F polysaccharide derived from a rough variant of Type I pneumococcus (I R) is antigenic in rabbits and gives rise to precipitins and sheep cell hemolysins. The somatic or C carbohydrate on the other hand is not antigenic. 2. Antisera for the rough variant of Type 1 pneumococcus contain also bacterial agglutinins immunologically unrelated to the C and F precipitins and the heterophile antibody. 3. A study has been made of the quantitative precipitin reaction of the C and F polysaccharides in the serum of rabbits immunized with the IR pneumococcus clarifying certain of these relationships. PMID- 19871296 TI - BIOCHEMICAL STUDIES ON THE VIRUS AND THE INCLUSION BODIES OF SILKWORM JAUNDICE. AB - Silkworm jaundice virus is stable only between pH 5 and about pH 9. The fact that polyhedral bodies retain virus activity after exposure to hydrogen ion concentrations as high as pH 2 is regarded as being due to the protection of virus occluded within the bodies. Further evidence on this point is furnished by experiments on the activity of the polyhedra when treated with antiformin formalin and when treated with 1 per cent sodium dodecyl sulfate. Free jaundice virus is inactivated by 36 per cent urea, 36 per cent guanidine, or 1 per cent sodium dodecyl sulfate. A purified preparation, active at a concentration of 10( 12) gm. per cc., consisting essentially of a nucleoprotein component having a sedimentation constant of 17 S, a particle diameter of 10 mmicro, and a molecular weight of about 300,000, was obtained from the polyhedra-free blood of jaundiced silkworms. However, a component having a sedimentation constant of 16 S was demonstrated in the blood of normal worms. This component, the material from diseased blood, and polyhedral bodies, were found to contain serologically related material. Absorption of material from diseased blood with antiserum induced by a preparation from normal blood yielded a substance having a sedimentation constant of 17 S, which reacted strongly only with antiserum to material from diseased blood. This fact, and especially the fact that the inoculation of normal blood does not produce jaundice, demonstrates that a difference must exist between the purified material from diseased worms and that from normal ones. Chemical analyses of the purified virus material and of the polyhedral bodies also showed certain differences, although both probably represent nucleoproteins. Examination by means of the electron microscope showed further differences. PMID- 19871297 TI - ANTIGENIC RELATIONSHIP OF BRITISH SWINE INFLUENZA STRAINS TO STANDARD HUMAN AND SWINE INFLUENZA VIRUSES : THE USE OF CHICKEN AND FERRET ANTISERA IN RED CELL AGGLUTINATION. AB - The antigenic relationships of Type A (PR 8, WS) and Type B (Lee) human strains and the Shope and British (Cambridge, North Ireland) swine strains were studied by specific antiserum inhibition of chicken red cell agglutination by the influenza virus. The Cambridge and North Ireland strains were found to be closely related to the Type A strains and differentiated from the Shope virus. The distinctive antigenicity of the Lee strain of Type B was confirmed. Specific antibodies were developed in chickens following single intraperitoneal injections of influenza virus. Inhibition tests yielded results, in the antigenic analysis of the influenza viruses examined, comparable to those obtained with ferret antisera. Specific inhibition of hemagglutination by influenza virus proved an effective method for the study of strain relationships. PMID- 19871298 TI - CHANGES IN LIPID CONTENT OF SERUM AND OF LIVER FOLLOWING BILATERAL RENAL ABLATION OR URETERAL LIGATION. AB - 1. In the dog and monkey bilateral nephrectomy or ureteral ligation results in a marked, progressive increase of total fatty acids, of free and esterified cholesterol, of phospholipid, and of free fat of serum. 2. No such changes follow unilateral nephrectomy, splenectomy, or fasting. 3. The increase after bilateral nephrectomy is not inhibited by glucose administration. 4. A marked increase of the phospholipid and a less significant elevation in cholesterol content of the liver accompanies this increase of serum lipids after bilateral nephrectomy. PMID- 19871299 TI - IMMUNITY TO YELLOW FEVER ENCEPHALITIS OF MONKEYS AND MICE IMMUNIZED BY NEURAL AND EXTRANEURAL ROUTES. AB - Monkeys and mice surviving cerebral infection with yellow fever virus of relatively avirulent strains have been found to resist maximal intracerebral doses of yellow fever virus of a highly neurotropic strain. Such animals, however, do not resist more than very small doses of intracerebrally inoculated virus of Eastern equine encephalomyelitis. Animals immunized by extraneural routes, on the other hand, are not uniformly resistant to neural infection with neurotropic yellow fever virus. Monkeys which have undergone systemic infection with virus of the avirulent 17D strain or of several jungle strains resist only small intracerebral doses of neurotropic virus; while mice, even when possessed of very high serum-antibody levels as the result of intraperitoneal hyperimmunization, manifest only an irregular resistance to intracerebral challenge inocula. The difference in the resistance of neurally and extraneurally immunized animals is not related to similar differences in the levels of protective antibody in the sera. Indeed, the average of the serum-antibody titers of the hyperimmune mice is several times that of the intracerebral immunes. A possibly significant relation does exist, however, between the resistance of mice to neural infection and the content of protective antibody in the brain. The protective activity of suspensions of brains from mice surviving cerebral infection was found to be several times that of brain suspensions from the hyperimmunized animals. It is concluded that the superior resistance to neural infection of animals whose immunity results from a previous non-fatal infection of the nervous system is effected by a specific local mechanism which is based at least in part upon an increased concentration of antibody in the cerebral tissue. PMID- 19871300 TI - NON-FATAL INFECTION OF MICE FOLLOWING INTRACEREBRAL INOCULATION OF YELLOW FEVER VIRUS. AB - Observations have been reported which indicate that mice inoculated intracerebrally with active yellow fever virus may develop an infection which is not only non-fatal but may also be completely inapparent. The most extensive observations were made on mice which showed signs of infection but were still alive 22 days after inoculation with virus of one or another of several 17D substrains. In such cases, the infection usually progressed no further and partial or complete recovery often ensued. Agents other than yellow fever virus were excluded as a significant cause of such nonfatal infections by the failure of repeated attempts to isolate other infective agents, by the demonstration of antibodies against yellow fever virus in the sera of the mice, and by the demonstration of a high degree of resistance on the part of such surviving mice to reinoculation with large doses of neurotropic yellow fever virus. Completely inapparent infections with 17D virus were also shown to occur. Studies of apparently normal survivors of 17D virus titrations revealed a small but significant number of animals resistant to intracerebral challenge with neurotropic yellow fever virus. Further, pooled sera from such mice were shown to contain specific protective antibodies. The occurrence of non-fatal infections with 17D virus was found related to virus dose and substrain. Small doses of virus provoked a significantly higher proportion of non-fatal infections than large doses; while different 17D substrains, tested over equivalent ranges of virus dose, varied greatly with respect to the proportion of infections which did not terminate with death. In the case of two substrains (17DD low and 17D(3)), non-fatal infections (as demonstrated by resistance to intracerebral challenge with neurotropic virus) were sufficiently frequent to cause an increase, when included in the computation of the infective titers, of 25 per cent above the figures based on deaths alone. The demonstration of non-fatal infections, thus, may be important to the accuracy of quantitative determinations of infectivity. Limited observations with virus of the French neurotropic and the pantropic Asibi strains revealed that non-fatal infections do occur, but only rarely. Somewhat more extensive observations with unmodified virus of strains isolated from Brazilian cases of jungle yellow fever, in contrast, revealed an occurrence of non-fatal infections much greater than that observed with the most productive 17D substrains. With these jungle strains, the demonstration of non-fatal infections proved indispensable to any measure of the level of infectivity of virus preparations. The demonstration of the proportional occurrence in mice of non fatal infections with yellow fever virus provides an additional means by which different virus strains and substrains may be characterized. PMID- 19871301 TI - VENEZUELAN EQUINE ENCEPHALOMYELITIS IN MAN. AB - A filterable agent was isolated from the blood and from washings of the upper respiratory passages of a young laboratory worker during a mild, acute, febrile illness. This agent was identified as a strain of Venezuelan equine encephalomyelitis virus. Circulating specific complement-fixing and neutralizing antibodies not present in sera withdrawn during the acute phase of illness were demonstrated in sera obtained during convalescence. A fellow laboratory worker who became similarly ill simultaneously also developed during convalescence specific circulating antibodies not present prior to illness. PMID- 19871302 TI - THE DETECTION OF POLIOMYELITIS VIRUS IN FLIES COLLECTED DURING EPIDEMICS OF POLIOMYELITIS : I. METHODS, RESULTS, AND TYPES OF FLIES INVOLVED. AB - 1. A series of 19 different samples of flies collected within epidemic areas during and after the onset of nearby human cases of poliomyelitis have been tested for the virus of poliomyelitis. Four of these samples proved positive. 2. Methods used in collecting the flies, preparing the inocula, and examining the inoculated monkeys (and other animals) are described. 3. All of the positive tests were obtained by the intranasal and intra-abdominal inoculation of Java (cynomolgus) monkeys. Green African and rhesus monkeys represented the smaller number of other monkeys used in which only negative results were obtained. 4. All of the positive samples (as well as nearly all the negative ones) contained "blow flies," and green bottle flies. PMID- 19871303 TI - THE DETECTION OF POLIOMYELITIS VIRUS IN FLIES COLLECTED DURING EPIDEMICS OF POLIOMYELITIS : II. CLINICAL CIRCUMSTANCES UNDER WHICH FLIES WERE COLLECTED. AB - During the summer and fall of 1941, 19 samples of flies were collected in epidemic areas both during and after epidemics of poliomyelitis. Of 8 samples collected for the most part during the latter part of a local epidemic but within 10 days of the onset of a local case of poliomyelitis, 4 yielded the virus; whereas of 8 samples collected more than 10 days from the onset of the last local case, none yielded the virus. In 4 instances there was a potential (though not proven) source of virus (in the form of "exposed" human feces of recent origin) within a few yards or few feet of the site where fly collections were made. Collections of flies from 3 of these sites yielded the virus. No attempt is made in this paper to develop epidemiological implications from this finding. PMID- 19871304 TI - THE INFLUENCE OF BIOTIN UPON SUSCEPTIBILITY TO MALARIA. AB - Biotin-deficient chickens and ducks developed much more severe infections with Plasmodium lophurae than did non-deficient control animals. While a very mild degree of biotin deficiency sufficed to increase susceptibility, even an extreme degree of pantothenic acid deficiency had no effect. Biotin deficiency also increased the susceptibility of ducks to P. cathemerium. In animals infected with P. lophurae, the concentration of biotin in the plasma as well as in the red cells rose during the course of the infection, reached a peak at about the same time as the parasite number reached its peak, and then returned to normal as the infection subsided. While the administration of additional biotin to animals partially deficient in biotin could be considered a specific measure tending to lessen the severity of infection with P. lophurae, the injection of biotin into animals fed a diet adequate in this vitamin had no antimalarial effects, perhaps because the excess biotin was rapidly removed from the blood. PMID- 19871305 TI - ANTIGENIC PROPERTIES OF NATIVE AND REGENERATED HORSE SERUM ALBUMIN. AB - Comparative immunological measurements have been carried out on crystalline horse serum albumin in the native state and after regeneration from 8 M urea solutions. The mean antigenic activity of the regenerated protein has been found to be less than 10 per cent of that of the native, whereas both antigens proved to be immunologically equivalent. The problem of the relation between protein denaturation and immunological activity has been considered and discussed on the basis of known physical and chemical differences between native and denatured protein. PMID- 19871306 TI - THE INFLUENCE OF AGE OF HOST AND TEMPERATURE OF INCUBATION ON INFECTION OF THE CHICK EMBRYO WITH VESICULAR STOMATITIS VIRUS. AB - Chick embryos after 7 days of incubation were found to be much more susceptible to infection with vesicular stomatitis virus than were 10 day embryos. They had a 100 per cent mortality and were very suitable for titrations of the virus. The rate of increase of virus in 7 and 10 day embryos was studied. Two different temperatures of incubation were employed, 35-36 degrees C. and 39-40 degrees C., and the growth curves for the virus under the different conditions are presented. 10 day embryos were highly resistant and at 39-40 degrees C. more than half of them survived. At the lower temperature of incubation, 35-36 degrees C., all 10 day embryos died, but they survived much longer than did 7 day embryos. In the 7 day embryos death occurred after about 12 hours at 39-40 degrees C. and after about 16 hours at 35-36 degrees C., or earlier at the higher temperature. In embryos of both ages the virus titer reached at the higher temperature was only about 1 per cent of that reached at 35-36 degrees C., even in those that died. PMID- 19871307 TI - STUDIES ON THE SITE OF ANTIBODY FORMATION IN RABBITS FOLLOWING INTRACUTANEOUS INJECTIONS OF PNEUMOCOCCUS OR OF STREPTOCOCCUS VACCINE. AB - 1. The antibody response of rabbits following intracutaneous injections of pneumococcus or of streptococcus vaccines showed three phases. (a) Within 5 to 12 days following a single injection of pneumococcus or of streptococcus vaccine, high antibody titres were detected in extracts from the site of the injection into the skin, the spleen, the bone marrow, and the liver. Occasionally, antibodies were also found in the draining lymph nodes. During this first phase, the titre of the circulating antibodies was low or negative. (b) During the next phase, when the interval between antigen injection and antibody titrations was prolonged from 2 to 4 weeks, the titres of the blood and of the organs showed only slight differences. High titres were observed during this period in extracts from the injected parts of the skin. (c) After a still longer interval during a third phase of antibody response, the serum titre decreased more rapidly than the titre of the extracts from spleen, bone marrow, and injected skin. 2. Similar results were obtained in rabbits following repeated intracutaneous injections of the vaccines. In these rabbits, however, antibodies usually were not detected during the first phase in extracts from the site of the injection into the skin. The repeated injections of the antigen had perhaps neutralized locally formed antibodies and interfered with their detection until an excess of antibodies was produced. No antibodies were found in the lymph nodes of the rabbits that had received repeated injections of vaccines. 3. The antibody titre of the kidney, anterior wall of the stomach, and non-injected parts of the skin was negative or very low. 4. The demonstration of antibodies in extracts from the site of the injection of antigen into the skin and their presence in lymph nodes before they are demonstrable in the blood shows that they are formed at the local site of inflammation. At the same time antibodies are formed in organs that fix antigen, namely in spleen, liver, and bone marrow. PMID- 19871308 TI - HYPOTENSION AND LOSS OF PRESSOR RESPONSE TO ANGIOTONIN AS THE RESULT OF TRAUMA TO THE CENTRAL NERVOUS SYSTEM AND SEVERE HEMORRHAGE. AB - 1. Angiotonin refractoriness and hypotension follow upon injury to the central nervous system in dogs and cats. Refractoriness does not develop when the nervous system is quickly and expertly destroyed or the activity of the nervous system depressed by widespread injection into it of a local anesthetic. The syndrome develops in the absence of the kidneys and the suprarenal glands. 2. Glycine, methyl isothiourea, and rest are the only agents studied which tend to restore responsiveness, and the first two of these have only an irregular and temporary effect. 3. There is a marked degree of specificity in the syndrome since undiminished pressor responses to adrenalin, tyramine, methyl isothiourea are observed during complete angiotonin refractoriness. 4. Despite the prolonged hypotension, change in the amount of plasma proteins and in the hematocrit readings is not striking. 5. Parallelism seems to exist between the fall in blood pressure after trauma to the nervous system and development of angiotonin refractoriness. After the syndrome has developed, elevation of the blood pressure by the injection of gum acacia solution or whole blood does not restore the responsiveness to angiotonin. 6. Angiotonin refractoriness and hypotension also develop after marked hemorrhage. Suprarenalectomy or nephrectomy does not prevent its appearance. PMID- 19871309 TI - STUDIES IN SENSITIZATION TO SKIN : I. THE PRODUCTION OF ANTIBODIES TO SKIN BY MEANS OF THE SYNERGISTIC ACTION OF HOMOLOGOUS SKIN ANTIGEN AND STAPHYLOCOCCUS TOXIN. AB - 1. Techniques for the preparation of skin antigen suitable for intramuscular injection in rabbits, and of skin antigens (autolysate) for serological experiments are described. 2. A method was evolved which produced a soluble skin antigen (autolysate) suitable for performing precipitin tests. 3. Injection of the rabbit skin antigen and of staphylococcus toxin in rabbits resulted in the formation of antibodies (precipitins) to homologous skin. 4. When homologous skin alone was injected into rabbits, the antibody formation was questionable, or at most, slight. 5. The injection of staphylococcus toxin alone resulted in antibody formation, this antibody being specific for the toxin and not reacting with broth. 6. By utilization of the synergistic action of staphylococcus toxin and of homologous skin antigen, it has been possible for the first time to produce specific antiskin antibodies in experimental animals. PMID- 19871310 TI - STUDIES ON EXPERIMENTAL HYPERTENSION : XXI. THE PURIFICATION OF RENIN. AB - 1. Extraction of finely ground fresh hog kidney with distilled water adjusted to pH 7.8 with sodium hydroxide, followed by successive treatment, as described, with trichloroacetic acid and acetone, gives renin in good yield of a purity suitable for physiological studies and a good starting material for further purification. It contains 15 dog units per mg. N. 2. Further successive purification of this material with ethyl alcohol and ammonium sulfate gives a preparation containing 130 dog units per mg. N. The purest preparation hitherto reported (15) contained 16.0 to 20.8 units per mg. N. Preliminary Tiselius electrophoresis studies suggest homogeneity, but further studies to establish purity are in progress. 3. The properties of the most purified renin indicate that it is a protein. Its chemical and physiological properties correspond to those of the material in crude renal extract which induces an elevation of blood pressure when it is injected intravenously. PMID- 19871311 TI - THE METABOLISM OF THE ISCHEMIC KIDNEY : I. THE RESPIRATION AND THE OXIDASE ACTIVITY OF THE ISCHEMIC KIDNEY. AB - The consumption of oxygen by slices of kidney tissue of dogs made hypertensive by the Goldblatt technique was studied manometrically. The respiration of the ischemic kidney tissue was found to be much less than that of the normal kidney. Further, a marked reduction in oxidizing ability, as measured by the oxygen uptake and ammonia formation in the presence of the added amines and amino acids, tyramine, isoamylamine, dl-alanine, and l-aspartic acid, was observed. Extracts of the kidneys were made and tested for amine oxidase, amino acid oxidase, and polyphenol oxidase activity by measuring the increased oxygen consumption and ammonia formation in the presence of the substrates listed above with the addition of l-epinephrine, histamine, and dl- and l-dihydroxyphenylalanine. The preparations from ischemic kidneys of dogs and rabbits showed much lower activity. Animals with varying degrees of constriction of the renal arteries and therefore varying degrees of renal ischemia were prepared and studied. The results with these animals suggested a direct relationship between the degree of renal ischemia and the decrease in oxidizing power of the tissue. The product of the enzymic oxidation of tyramine was identified as p-hydroxyphenylacetaldehyde by isolation as the dinitrophenylhydrazone of p-hydroxyphenylacetaldehyde. PMID- 19871312 TI - SYNERGISTIC ACTION OF HEMOPHILUS INFLUENZAE SUIS AND THE SWINE INFLUENZA VIRUS ON THE CHICK EMBRYO. II. AB - Blood cultures of embryos killed by the synergistic action of swine influenza virus and Hemophilus influenzae suis are consistently negative, and embryos infected with swine influenza virus may be killed both by filtered extracts of frozen and dried Hemophilus and by suspensions of heat-killed bacteria. The addition of Hemophilus to the chorioallantoic membrane of embryos infected with swine influenza virus causes the virus to spread from the membrane to the allantoic fluid and embryo. This spreading effect also obtains when a purified preparation of hyaluronidase is used instead of Hemophilus, but it is unaccompanied by a comparable increase in mortality. It is probable that the spread of the virus produced by the bacteria is only partly responsible for the development of the complex infection and that products of these organisms other than the spreading factor play a large part in the mortality of embryos receiving the combination of virus and bacterium. PMID- 19871313 TI - FURTHER STUDIES ON THE TITRATION AND NEUTRALIZATION OF THE WESTERN STRAIN OF EQUINE ENCEPHALOMYELITIS VIRUS IN TISSUE CULTURE. AB - 1. Titration and neutralization of the Western strain of equine encephalomyelitis virus can be carried out in vitro by means of tissue culture. 2. The in vitro titration test as presented is a more sensitive method than animal inoculation. 3. Tissue culture may be better than animal inoculation for the detection of small amounts of virus. 4. The neutralization obtained in tissue culture is 100 to 1,000 times greater than that observed in the intracerebral test in mice and is comparable to the potency obtained by the intraperitoneal route of inoculation. 5. The possibility of applying this method to the study of other viruses, known and unknown, is discussed. 6. Further applications of the method described above to evaluation and standardization of bacterial toxins and antitoxins and to the testing of the toxicity of biological and chemical products are suggested. 7. Evidence for the reactivation in vitro as well as in vivo of virus in neutral mixtures by dilution is presented. PMID- 19871314 TI - TYPING GROUP A HEMOLYTIC STREPTOCOCCI BY M PRECIPITIN REACTIONS IN CAPILLARY PIPETTES. AB - A method is described for performing type-specific anti-M precipitin tests on group A hemolytic streptococci in 1 mm. capillary pipettes. These tests require so much less precipitating serum than was formerly used that the method now seems to be practical. PMID- 19871315 TI - REACTIONS IN SKIN AND IN INTERNAL ORGANS OF RABBITS SENSITIZED WITH STREPTOCOCCUS OR WITH PNEUMOCOCCUS VACCINE AND THEIR RELATIONSHIP TO ANTIBODIES. AB - 1. Homologous vaccine was injected into abdominal organs of rabbits after different intervals following sensitization by a single or by repeated intracutaneous injections of heat-killed pneumococci Type I or of formalin-killed hemolytic streptococci (Strain AB(13)). 2. Local inflammation with or without necrosis was observed in the liver and in the spleen of most of the rabbits. Injections into the kidney and into the anterior wall of the stomach usually caused hemorrhagic lesions at the site of injections, frequently accompanied by slight or moderate inflammation and seldom by necrosis. 3. No correlation was found between the skin and the organ reactions of the animals sensitized with killed streptococci or with killed pneumococci. There was also no correlation between skin or organ reactions and antibody titre of serum. 4. Allergic reactions occur in those organs, namely, liver and spleen, in which antibodies are demonstrable in a high titre, and they are usually absent in kidney and stomach wall in which the antibody titre is low or negative. It is probable that the reactions are caused by the union of antigen and its specific antibody in the tissue. PMID- 19871316 TI - INCREASED RESISTANCE TO VIRAL INFECTION AS A RESULT OF INCREASED FLUID IN TISSUES. AB - Experiments are described in which it is shown that the estrogenic hormone (alpha estradiol propionate) increases the amount of extracellular fluid in the skin. Since previous work showed that this hormone increases resistance of rabbits to vaccinia virus, it is suggested that the increased resistance is the result of increased fluid in the tissues. In further test of this thesis, experiments were performed in which the extracellular fluid in the skin was increased by the intraperitoneal injection of a salt solution known to increase the hydration of the tissues. Under these conditions it was found that the spread of India ink in the skin, as well as susceptibility to viral infection, was decreased in the same magnitude as obtains when the animals are treated with estrogenic hormone. The identity of effects under the two sets of circumstances seems to warrant the conclusion that in both instances the spread of India ink and decreased susceptibility to vaccinia are due to the common factor of increased volume of the extracellular fluid. PMID- 19871317 TI - ADSORPTION OF INFLUENZA VIRUS ON CELLS OF THE RESPIRATORY TRACT. AB - A STUDY OF THE REACTION BETWEEN INFLUENZA VIRUS AND THE CELLS OF THE EXCISED AND PERFUSED FERRET LUNG HAS YIELDED THE FOLLOWING RESULTS: (1) The cells of the lung rapidly adsorbed large amounts of intratracheally inoculated virus. (2) After a short interval the pulmonary cells began spontaneously to release the adsorbed virus, and in the case of influenza B the release was 75 per cent complete after 5 hours. (3) The Lee strain was more completely released from pulmonary cells after 5 hours than was the PR8 strain. (4) After the cells released the adsorbed virus they appeared incapable of adsorbing virus as before. (5) When the mouse infecting capacity of the virus had been done away with by heat or formalin, the virus was adsorbed by the pulmonary cells but was not released. In all except the last of the characteristics listed the interaction between influenza virus and the pulmonary cells closely resembles that between influenza virus and avian red blood cells. In the living ferret inhaled influenza virus was also rapidly adsorbed by the lung, but in a very short time the adsorbed virus which at first could be readily eluted (after perfusion and excision of the lung) became so much more firmly fixed as not to be released by this method. Free virus could not be demonstrated in the living ferret until 24 hours after the animal had been exposed to the inoculum. On the basis of these and previous experiments it is postulated that the destruction of a specific receptor substance,-which may involve an enzymatic reaction,-may be a necessary preliminary event in the parasitism of susceptible cells by influenza virus. PMID- 19871318 TI - THE ELIMINATION OF ADMINISTERED ZINC IN PANCREATIC JUICE, DUODENAL JUICE, AND BILE OF THE DOG AS MEASURED BY ITS RADIOACTIVE ISOTOPE (Zn). AB - The excretion of intravenously injected labeled zinc into pancreatic juice, duodenal juice, and bile of the dog was investigated. The use of the radioactive isotope permitted the injection of minute amounts of zinc, amounts that were negligible when compared with the total amount of zinc already present in the animal. 1. A large proportion of the injected Zn(65) was eliminated by way of the external secretion of the pancreas. As much as 11 per cent was excreted in the pancreatic juice in 14 days. 2. Very little of the administered radiozinc appeared in the bile. The maximum excretion observed for this pathway was 0.4 per cent in 8 days. 3. Radiozinc was also found in large amounts in the juice obtained from an isolated loop of the duodenum. PMID- 19871319 TI - THE MULTIPLICATION OF BACTERIOPHAGE IN VIVO AND ITS PROTECTIVE EFFECT AGAINST AN EXPERIMENTAL INFECTION WITH SHIGELLA DYSENTERIAE. AB - 1. Anti-Shiga bacteriophage injected into the general circulation can multiply in the brain of mice infected intracerebrally with Shigella dysenteriae. 2. Under proper conditions, the injection of active bacteriophage into the general circulation can protect mice against an otherwise fatal intracerebral infection with Shigella dysenteriae. 3. The protection so induced appears to depend upon the early establishment of a high bacteriophage level in the infected animal. PMID- 19871320 TI - RADIOACTIVE IRON ABSORPTION BY GASTRO-INTESTINAL TRACT : INFLUENCE OF ANEMIA, ANOXIA, AND ANTECEDENT FEEDING DISTRIBUTION IN GROWING DOGS. AB - Iron absorption is a function of the gastro-intestinal mucosal epithelium. The normal non-anemic dog absorbs little iron but chronic anemia due to blood loss brings about considerable absorption-perhaps 5 to 15 times normal. In general the same differences are observed in man (1). Sudden change from normal to severe anemia within 24 hours does not significantly increase iron absorption. As the days pass new hemoglobin is formed. The body iron stores are depleted and within 7 days iron absorption is active, even when the red cell hematocrit is rising. Anoxemia of 50 per cent normal oxygen concentration for 48 hours does not significantly enhance iron absorption. In this respect it resembles acute anemia. Ordinary doses of iron given 1 to 6 hours before radio-iron will cause some "mucosa block"-that is an intake of radio-iron less than anticipated. Many variables which modify peristalsis come into this reaction. Iron given by vein some days before the dose of radio-iron does not appear to inhibit iron absorption. Plasma radio-iron absorption curves vary greatly. The curves may show sharp peaks in 1 to 2 hours when the iron is given in an empty stomach but after 6 hours when the radio-iron is given with food. Duration time of curves also varies widely, the plasma iron returning to normal in 6 to 12 hours. Gastric, duodenal, or jejunal pouches all show very active absorption of iron. The plasma concentration peak may reach a maximum before the solution of iron is removed from the gastric pouch-another example of "mucosa block." Absorption and distribution of radio-iron in the body of growing pups give very suggestive experimental data. The spleen, heart, upper gastro-intestinal tract, marrow, and pancreas show more radio-iron than was expected. The term "physiological saturation" with iron may be applied to the gastro-intestinal mucosal epithelium and explain one phase of acceptance or refusal of ingested iron. Desaturation is a matter of days not hours, whereas saturation may take place within 1 to 2 hours. We believe this change is a part of the complex protein metabolism of the cell. PMID- 19871321 TI - AN OUTBREAK OF PSITTACOSIS IN PIGEONS, INVOLVING THE PRODUCTION OF INCLUSION BODIES, AND TRANSFER OF THE DISEASE TO MAN. AB - An epizootic disease in pigeons associated with atypical pneumonia in two persons handling the birds has been studied. Most of the observations made during the work were consistent with the idea that we were dealing with an infection caused by a member of the psittacosis-lymphogranuloma venereum group of viruses. The outbreak was peculiar, however, in that tissues of the diseased pigeons contained many intranuclear inclusions and that the viruses isolated from these birds produced both intranuclear inclusions and elementary bodies in the cytoplasm of cells of chorio-allantoic membranes of the developing egg. Whether the pigeons were simultaneously infected with two viruses or whether the virus of pigeon psittacosis can produce intranuclear inclusions under certain conditions remains to be determined. PMID- 19871322 TI - EFFECTS OF HYPOTENSION DUE TO HEMORRHAGE AND OF BLOOD TRANSFUSION ON RENAL FUNCTION IN DOGS. AB - 1. Renal blood flow is decreased by hypotension due to bleeding, and glomerular filtration rate is disproportionately decreased. After a first 40 minute stage of hypotension at about 60 mm. Hg infusion of blood with consequent restoration of the general blood volume and arterial pressure usually results in a return to normal of renal blood flow and function although renal blood flow subsequently tends to decrease. The restoration of renal blood flow and function is associated with an increase of urine flow above the control level. 2. Diodrast clearance loses its value as a measure of renal plasma flow (a) during severe or prolonged hypotension, and (b) immediately after restoration of arterial pressure by infusion after a first stage of hypotension. In the former case (a) it is decreased in consequence of decreased renal extraction of diodrast from blood which itself is presumably the result of distribution of renal blood flow through nephrons whose vascular resistance is low. (b) The disparity after transfusion is due to excretion of diodrast accumulated in the kidney tubules and, presumably, in the interstitial fluid during hypotension. The presence of diodrast and inulin in the renal interstitial fluid explains the addition of these substances to renal venous blood observed in some of these experiments. The shifting equilibrium of diodrast between renal plasma and interstitial fluid may explain some of the instances of low diodrast extraction observed in these experiments during transfusion after hypotension, and may explain also the incomplete renal extraction of diodrast under normal conditions. 3. Dogs with denervated kidneys respond to blood transfusion and restoration of arterial pressure by a disproportionately slow and incomplete return towards normal of renal clearance and, presumably, of renal blood flow. On the basis of these facts it is suggested that high spinal anesthesia may interfere with recovery of renal circulation in cases of shock treated by transfusion. 4. Profound or prolonged and repeated hypotension due to bleeding decreases the ability of normal and denervated kidneys of intact and anesthetized dogs to respond to transfusion and the restoration of arterial pressure by proportionately increased clearance and plasma flow, apparently because of renal vasoconstriction due to the release of humorally circulating vasoconstrictor substances. PMID- 19871323 TI - THE DISAPPEARANCE OF PHOSPHATASE FROM THE HYDRONEPHROTIC KIDNEY. AB - "Alkaline" phosphatase disappears or only remains in small amounts in the rabbit and rat kidney after periods of hydronephrosis of 2 to 5 days or more, following complete obstruction of the ureter. By the use of the Gomori-Takamatsu technique it has been possible to distinguish normally functioning from non-functioning cells, when by ordinary histologic stains the cells are indistinguishable. PMID- 19871324 TI - THE STABILITY OF VARIOLA VIRUS PROPAGATED IN EMBRYONATED EGGS. AB - After 24 transfers in embryonated eggs a strain of variola virus (Chinese) was established in the testis of the rabbit and maintained for 11 passages at intervals of 7 days. Residence in the rabbit testis was not accompanied by any significant alteration in the species identity of the virus. A second strain of variola virus (Minnesota) was transferred 180 times in embryonated eggs with no apparent change in its behavior. Subsequent attempts, however, to maintain this strain in the rabbit by serial testicular passage were unsuccessful. These observations are discussed in relation to the so called transformation of variola to vaccinia virus by animal passage. PMID- 19871325 TI - LABORATORY TRANSMISSION OF ST. LOUIS ENCEPHALITIS VIRUS BY THREE GENERA OF MOSQUITOES. AB - 1. St. Louis virus has been successfully transmitted in the laboratory by the following 9 species of mosquitoes from 3 genera: Culex tarsalis, Culex pipiens, Culex coronator, Aedes lateralis, Aedes taeniorhynchus, Aedes vexans, Aedes nigromaculis, Theobaldia incidens, and Theobaldia inornata. 2. Though transmission has not been demonstrated, survival of the virus for more than a few days was shown to occur in Culex quinquefasciatus, Culex stigmatosoma, Psorophora ciliata, and Anopheles maculipennis freeborni. 3. In experiments with Culex tarsalis, infection occurred from feeding on chickens and ducks which had been previously inoculated by the subcutaneous route. After an incubation period these mosquitoes infected other chickens and virus was in turn demonstrated in the blood of these. This is interpreted as proof that fowl may serve as reservoirs of virus in nature. Since mosquitoes have been repeatedly found naturally infected with St. Louis virus and epidemiologic evidence supports their incrimination, their role as vectors is now established. The fully incriminated species is Culex tarsalis. PMID- 19871326 TI - THE OXIDATION OF p-AMINOBENZOIC ACID AND ANTHRANILIC ACID BY SPECIFICALLY ADAPTED ENZYMES OF A SOIL BACILLUS. AB - 1. A soil bacillus has been isolated capable of developing specific adaptive enzymes which oxidize PABA apparently to carbon dioxide, water, and ammonia. A few related compounds which, however, do not give the diazo reaction are similarly attacked. 2. This bacillus is also capable of developing analogous but apparently independent adaptive enzymes specifically directed against anthranilic acid, the ortho isomer of PABA. 3. Sulfapyridine is bacteriostatic for this bacillus and this effect is inhibited as in the case of other bacterial species by PABA. Other effects of the sulfonamide drugs and sulfanilic acid upon the specific oxidative enzymes have been described. 4. The specific adaptive enzymes of this soil bacillus may be used for the identification of as little as 10 gamma of either PABA or OABA. A method is described for carrying out these determinations. 5. The possible advantages of this enzymatic method as compared with the more sensitive but less specific techniques which measure the activity of PABA as a growth factor for certain bacterial species have been discussed. PMID- 19871327 TI - SUSCEPTIBILITY OF CEBUS CAPUCINA (THE SOUTH AMERICAN RINGTAIL MONKEY) AND CERCOPITHECUS CEPHUS (THE AFRICAN MUSTACHE MONKEY) TO POLIOMYELITIS VIRUS. AB - 1. The South American ringtail monkey, Cebus capucina, has been infected with the virus of poliomyelitis as found in ultracentrifuged concentrates from poliomyelitic human stools. 2. This species was also found susceptible to poliomyelitis virus found in rhesus and cynomolgus monkey cords, representing early generations of virus derived from two different human sources and from flies trapped in an epidemic area. 3. The Hartford strain of poliomyelitis has been successfully established in different generations in Cebus capucina monkeys. 4. The African mustache monkey, Cerocopithecus cephus, has been infected with poliomyelitis virus by the intra- and subcutaneous routes as readily as the green African monkey, Cercopithecus aethiops sabaeus, and the rhesus monkey, Macaca mulatta. PMID- 19871328 TI - THE EFFECTS OF ROENTGEN RAYS ON CELL-VIRUS ASSOCIATIONS : FINDINGS WITH VIRUS INDUCED RABBIT PAPILLOMAS AND FIBROMAS. AB - The virus-induced papillomas of cottontail as well as domestic rabbits regress completely within a few weeks when exposed to 5,000 r of x-ray irradiation. The x rays do not immediately kill the papilloma cells, but lead to death by inhibiting cellular division and producing pathological changes in the cells which then continue to differentiate. The virus associated with the growths, however, not only persists in undiminished amount during regression, but often an increased yield of it can be obtained on extraction. The fibroma virus in crude extracts or in vivo is inactivated by far less irradiation than the papilloma virus. 10,000 r destroys 90 per cent or more of the infectivity of the fibroma virus, whereas at least 100,000 r is required to inactivate 50 per cent of the papilloma virus in extracts containing about the same amount of protein. No variant of the papilloma virus or fibroma virus has been encountered as a result of the irradiation. PMID- 19871329 TI - STUDIES ON HERPETIC INFECTION IN MICE : I. PASSIVE PROTECTION AGAINST VIRUS INOCULATED INTRANASALLY. AB - Passive immunity, naturally acquired from immune mothers or artificially induced through the administration of immune rabbit serum, conferred on suckling mice of the albino Swiss strain a high degree of resistance against herpetic infection following the intranasal instillation of the virus. Antibodies, which could be readily demonstrated in the blood of 2-week-old mice, were received by the offspring of immune mothers primarily by the mammary route. Naturally acquired immunity declined rapidly when suckling was interrupted. Herpes virus was not recovered from the fetuses of either immune or infected, non-immune mothers. PMID- 19871330 TI - STUDIES ON HERPETIC INFECTION IN MICE : II. THE PATHWAYS OF INVASION OF THE CENTRAL NERVOUS SYSTEM AFTER INTRANASAL INSTILLATION OF VIRUS IN SUCKLING MICE. AB - Instilled intranasally into suckling mice, a mouse-passaged strain of herpes virus (HF) reaches the brain by both the trigeminal and olfactory pathways. PMID- 19871331 TI - STUDIES ON HERPETIC INFECTION IN MICE : III. THE VISCERAL LESIONS IN SUCKLING MICE. AB - Intranasal instillation of herpes virus in suckling mice results in specific lesions widely distributed in the viscera. The lungs are infected by aspiration of the virus. Virus disseminated by way of the blood establishes itself in endothelium in certain situations where parenchymal lesions result by direct spread from the vascular foci. Evidence of blood-borne infection was found frequently in the liver and spleen, less frequently in the suprarenals, and, in one instance, in the bone marrow. Renal infection appeared to be uriniferous. Lymph carriage of the virus also occurs, and lymph nodes draining infected areas were often found to contain herpetic inclusion bodies. Herpes virus seems incapable of invading the central nervous system of suckling mice by the vascular route. PMID- 19871332 TI - THE PNEUMOCOCCAL CAPSULAR SWELLING REACTION, STUDIED WITH THE AID OF THE ELECTRON MICROSCOPE. AB - Electron micrographs indicate, in harmony with previous findings, that the pneumococcal capsule is a gel of low density outside of and closely applied to the bacterial cell wall. Interaction with homologous immune rabbit serum greatly increases the thickness and density of this capsular gel; the increase in thickness of the specifically swollen pneumococcal capsule may exceed by 25-fold the thickness of the surface deposit caused by rabbit immune serum on the cell walls and flagella of homologous non-capsulated bacteria. Conclusions drawn from these and earlier data are that homologous immune serum permeates the pneumococcal capsular gel; the specific antibody combines with the capsular polysaccharide; non-specific serum components are secondarily adsorbed to or combined with the specific antigen-antibody complex. The relatively low antibacterial titers characteristic of pneumococcal antisera can be explained in part by the permeation of the capsule by antiserum, in part by the high combining capacity of pneumococcal carbohydrate for antibody (17). PMID- 19871333 TI - PRODUCTION OF A SCURVY-LIKE CONDITION BY FEEDING OF A COMPOUND STRUCTURALLY RELATED TO ASCORBIC ACID. AB - The feeding of glucoascorbic acid, an analog of ascorbic acid, to mice and cotton rats caused the production of a condition exhibiting many of the changes characteristic of scurvy as seen in susceptible species. The condition was not prevented or cured by ascorbic acid, but was cured by removal of the glucoascorbic acid from the ration. The condition was produced in mice fed a highly purified ration. It was not produced in mice fed a natural ration. The presence of a substance in certain plant products which prevented the production of the condition was demonstrated. PMID- 19871334 TI - THE YIELD OF RABIES VIRUS IN THE CHICK EMBRYO. AB - Rabies virus was inoculated intracerebrally in 8 day old chick embryos and the virus activity of pools of embryos titered after incubation at 35-36 degrees C. for different lengths of time. The virus reached a titer of 10(-5.5) to 10(-6.5) in 5 to to 6 days and remained at a rather constant level until the 9th day of the infection. The report by Kligler and Bernkopf that rabies virus will invade the very young embryo after inoculation on the chorioallantoic membrane was confirmed. PMID- 19871335 TI - THE IMMUNOLOGICAL RESPONSE TO INFLUENZA VIRUS INFECTION AS MEASURED BY THE COMPLEMENT FIXATION TEST : RELATION OF THE COMPLEMENT-FIXING ANTIGEN TO THE VIRUS PARTICLE. AB - A quantitative complement fixation test with influenza immune sera and virus antigens obtained from allantoic fluid is described. The method utilizes a photoelectric densitometer which provides a simple, objective, and accurate determination of the hemolytic reaction. The enhancement of the hemolytic activity of complement in the presence of serum or allantoic fluid necessitates a preliminary titration of complement in the presence of these agents. An accurate appraisal of the activity of the complement under the conditions of the actual test permits the selection of an optimal amount of complement and greatly increases the sensitivity of the test. The substance (or substances) responsible for the enhanced hemolytic activity of complement has been found in human and many animal sera and in allantoic fluids obtained from the developing chick embryo. It requires the presence of both complement and hemolysin, resists heating at 100 degrees C. for 2 hours, and is dialyzable. Allantoic fluid or mouse lung preparations of influenza virus contain a complement-fixing antigen which is intimately associated with the virus particle. It sediments in the high speed centrifuge at the same rate as the hemagglutinin and infective particle and, like the latter, is adsorbed by fowl red blood cells and eluted from the cells on standing at room temperature or 37 degrees C. It cannot be separated from the virus particle by repeated washings in the centrifuge or repeated adsorptions with red blood cells; the hemagglutinin and complement-fixing antigen titers remain roughly proportional. This antigen shows a high degree of strain specificity in cross complement fixation tests with PR8, W.S., and swine ferret antisera, and, as found with the neutralization test, it shows little or no strain specificity with human sera. A soluble antigen is also present in influenza virus preparations which can be readily separated from the virus particle by centrifugation. It is not adsorbed by red blood cells. Furthermore, it reacts in lower titer with ferret antisera and usually shows less strain specificity in cross complement fixation tests. In general, allantoic fluid virus preparations contain much less of the soluble antigen than mouse lung extracts. PMID- 19871336 TI - A KINETIC ANALYSIS OF THE RENIN-ANGIOTONIN PRESSOR SYSTEM AND THE STANDARDIZATION OF THE ENZYMES RENIN AND ANGIOTONASE. AB - The physicochemical background of the renal vasporessor system (renin-renin substrate, angiotinin, angiotonase) is given. The formation and destruction of angiotonin is shown to consist of two consecutive reactions, both of which follow the laws of first order kinetics. Each reaction was studied separately and its reaction constant found to be proportional to the enzyme concentration. Hence these constants should be used to express the activity of the enzymes, renin and angiotonase. The over-all reaction of a mixture of renin and angiotonase such as occurs in kidney extracts with the alpha-globulin fraction of serum, viz., rapid increase followed by a slow decline in angiotonin concentration, was found experimentally to correspond closely to the theoretical values calculated for such a reaction. The curve obtained also satisfyingly explains the characteristic pressor response to the intravenous injection of renin. An accurate method for the determination of renin in the presence of angiotonase is presented. PMID- 19871337 TI - THE BACTERICIDAL ACTION OF PROPYLENE GLYCOL VAPOR ON MICROORGANISMS SUSPENDED IN AIR : II. THE INFLUENCE OF VARIOUS FACTORS ON THE ACTIVITY OF THE VAPOR. AB - A study of the conditions which affect the bactericidal action of propylene glycol vapor on air-suspended microorganisms has been carried out. The killing process was found to be more effective when both the total number of air-borne droplets and the number of organisms in the bacterial suspension are small. A temperature below 80 degrees F. and an atmospheric relative humidity between 45 and 70 per cent were found to constitute the most favorable conditions for the lethal action of the vapor. Experiments were performed to test the bactericidal efficiency of propylene glycol vapor in both small and large enclosed spaces. These studies revealed that equally marked bactericidal action is obtained when propylene glycol is dispersed in an 800 cubic foot room as occurs in chambers of 2 cubic foot capacity. The susceptibility to vapor action of bacteria re suspended in saliva was just as great as when broth was used as the suspending medium. Both partially and completely dehydrated bacteria also succumbed to the effects of the vapor. However, when unsterile dust collected from inhabited rooms was dispersed into the air, little reduction of the natural microbic population contained in this material was observed. Data are presented showing the minimum glycol concentration necessary for effective bactericidal action on various microorganisms. Pneumococci were killed by amounts of propylene glycol as low as 1 gm. in 20 million cc. of air. Concentrations of 1 to 5 million to 1 to 10 million were required to produce the same degree of killing of streptococci and staphylococci. The observations here reported add further support to the previously proposed conception of the mechanism of the lethal action of propylene glycol vapor, namely, that a bactericidal concentration of the glycol accumulates in the bacterial droplet as a result of contact with and absorption of glycol molecules from the surrounding atmosphere. PMID- 19871338 TI - STUDIES OF ANTIGENIC DIFFERENCES AMONG STRAINS OF INFLUENZA A BY MEANS OF RED CELL AGGLUTINATION. AB - A study of cross inhibition tests among strains of influenza A virus and their antisera showed that the results obtained were subject to a certain amount of variation due to the red cells, the virus suspensions, and the ferret antisera employed. Methods have been demonstrated for handling the data obtained from such tests, so that these variables were corrected or avoided, making it possible to use the agglutination technique for antigenic comparisons. The antigenic pattern of eighteen strains of influenza A virus, obtained from the 1940-41 epidemic in the United States, has been compared by means of agglutination inhibition tests with ferret antisera. No significant antigenic differences were found among sixteen of these strains (all isolated from throat washings by the inoculation of chick embryos) although they were obtained from individuals in widely separated regions of the country. Two strains, from cases occurring early in the epidemic and isolated from throat washings by ferret and mouse passage, showed a slight but significant strain difference from the other strains and from each other. One of the 1940-41 strains on cross test resembled the PR8 strain more closely than any other stock strain tested. PMID- 19871339 TI - LABORATORY TRANSMISSION OF WESTERN EQUINE ENCEPHALOMYELITIS VIRUS BY MOSQUITOES OF THE GENERA CULEX AND CULISETA. AB - 1. Western equine virus has been successfully transmitted in the laboratory by 3 species of mosquitoes from 2 genera not previously reported as laboratory vectors: Culex tarsalis, Culiseta inornata, and Culiseta incidens. 2. Though transmission was not demonstrated, survival of the virus for more than a few days was shown to occur in Culex stigmatosoma and Psorophora confinnis. Possibly transmission occurred by the former. 3. In experiments with Culex tarsalis, infection of the mosquitoes occurred from feeding on an inoculated guinea pig, a duck, and virus-blood suspensions. After an incubation period of 10 to 30 days at a temperature above 25 degrees C. these mosquitoes infected chickens and a guinea pig by their bite and virus was in turn demonstrated in the blood of the chickens and in the brain of the guinea pig. A total of 12 transmissions occurred. The fact that mosquitoes can be infected from fowl and in turn transmit to fowl, together with much other supporting data from field and laboratory, is interpreted as strengthening evidence that fowl serve as reservoirs of virus in nature. 4. Since Culex tarsalis mosquitoes have been repeatedly found infected with Western equine virus and epidemiologic evidence supports their incrimination, the vector role of this species is now established, and it may be regarded as fully incriminated. 5. Culiseta inornata has also been found infected in nature and now proven a laboratory vector. This species does not fit the epidemiological picture in the Yakima Valley as well as C. tarsalis, but may play an important role elsewhere. 6. Anopheles maculipennis freeborni and Culex pipiens found naturally infected have not transmitted the virus under laboratory conditions. PMID- 19871340 TI - A FILTERABLE VIRUS CAUSING ENTERITIS AND PNEUMONIA IN CALVES. AB - An infectious disease of calves has been described which is characterized by fever, diarrhea, and pneumonia, followed soon by recovery. On autopsy of animals killed at the height of the disease, there is found a catarrhal enteritis and a bronchopneumonia that is usually confined to the anterior lobes of the lungs. From this disease an agent has been secured by the serial inoculation of lung extracts that produces a pneumonia in white mice. Attempts to demonstrate by the same means a similar agent in uninoculated mice from the same stock have yielded negative results. Suspensions of the lungs of the mice with pneumonia, when inoculated intranasally or intratracheally into calves, cause a disease like the natural infection, characterized by fever, diarrhea, and pneumonia. In two experiments pen contact of normal calves with calves inoculated with the passed material resulted in the typical disease. Early in its course the causative agent is found only in the lungs and intestines, but at its height is generally distributed throughout the body. Calves that have recovered from the induced disease are resistant to subsequent infection and their blood serum will neutralize the causative agent as not previously. Sera from calves that have recovered from the natural disease also neutralize the agent. Cultures from the infected lungs of calves and mice as a rule show no growth, and material that has been passed through Berkefeld N filters produces the characteristic disease. It is therefore concluded that this disease of calves is caused by a filterable virus. PMID- 19871341 TI - NEUTRALIZING AND COMPLEMENT-FIXING ANTIBODY PRODUCTION AND RESISTANCE FOLLOWING VACCINATION IN EXPERIMENTAL ENCEPHALITIS INFECTIONS. AB - In mice vaccinated subcutaneously with different doses of virulent W.E.E. virus or with formolized vaccine, neutralizing and complement-fixing antibodies paralleled resistance to some extent yet appeared in groups in which resistance remained undetectable, persisted at a similar maximum level in spite of different titers of resistance, and after resistance had become negligible. In mice vaccinated subcutaneously with different doses of virulent St. Louis encephalitis virus or with formolized vaccine, neutralizing and complement-fixing antibodies bore little relation to resistance. Neutralizing antibodies appeared only in the group showing resistance but not until resistance was diminishing. Complement fixing antibodies developed equally well in groups with or without resistance. PMID- 19871342 TI - STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : I. EFFECTS OF PROTEOLYTIC ENZYMES ON STREPTOCOCCAL CELLS. AB - 1. Proteolytic enzymes destroy the type-specific M antigen of group A hemolytic streptococci not only when the M substance is contained in cell-free extracts but also when it is a component of the living cell. 2. The injection of enzyme treated cultures into rabbits fails to induce the formation of M antibodies, but does result in the production of T antibodies and, therefore, provides a method of preparing anti-T sera free from M antibodies. 3. Exposure to these enzymes does not kill the bacteria. Virulence and the ability to form M substance are restored on subculture and animal inoculation. 4. The study of the effect of proteolytic enzymes on group A hemolytic streptococci provides new techniques for analyzing the antigenic composition of these microorganisms. PMID- 19871343 TI - WATER METABOLISM IN HYPERTENSIVE RATS. AB - The water intake in hypertensive rats was investigated. Rats made hypertensive by renal ischemia increased their water consumption by 75 per cent over the preoperative level. Polyuria was associated with this polydipsia and the independence of these occurrences from a number of other factors was demonstrated. It was found that the presence of a normal kidney exerted a compensatory influence which may mask either hypertension or polyuria or both. The appearance or exacerbation of the changes upon removal of the normal kidney, on the one hand, and the elimination or mitigation of the symptoms upon removal of the ischemic kidney on the other support the view that the changes observed cannot have been due to passive elimination of the kidney tissue by ischemia, but to active malfunction of the renal, and especially the tubular, mechanism upon withdrawal of oxygen. The view is put forward that polyuria is a primary sequel of ischemia rather than secondary to the intra- and extrarenal effects of hypertension. A number of concomitant observations are in harmony with this hypothesis. PMID- 19871344 TI - SELECTIVE REVERSIBLE INHIBITION OF MICROBIAL GROWTH WITH PYRITHIAMINE. AB - Growth of many microbial species was inhibited by pyrithiamine, the pyridine analog of thiamine. Growth of many other species was not influenced. In a series of bacteria, yeasts, and molds, it was found that inhibition of growth occurred only in those in which growth was stimulated by thiamine or its component pyrimidine and thiazole portions. The amount of pyrithiamine required for inhibition was correlated with the type of thiamine requirements of various species. The least amount was needed to inhibit organisms which required intact thiamine. Those which could use the pyrimidine and thiazole portions were not so readily inhibited. In the case of the former organisms, half maximal inhibition was produced by as little as 0.03 gamma per cc. In all instances, the inhibition was overcome by sufficient amounts of thiamine. The synthesis of thiamine by insusceptible species was studied, and it was concluded that formation of thiamine or other antagonistic substance did not provide an adequate explanation of the resistance of these species to the action of pyrithiamine. PMID- 19871345 TI - POLIOMYELITIS IN THE CYNOMOLGUS MONKEY : I. COMPARISON OF THE UPPER PORTION OF THE ALIMENTARY TRACT WITH ITS LOWER, GASTROINTESTINAL PORTION AS A PORTAL OF ENTRY, WITH SPECIAL REFERENCE TO THE PERIPHERAL GANGLIA. AB - 1. Cynomolgus monkeys were subjected to a series of non-traumatic exposures of the mucous membranes of the alimentary tract, designed to test the relative permeability to poliomyelitis virus of its upper and lower portions. 2. In the first stage, dried poliomyelitis virus of tested potency was administered in fat covered capsules to 26 monkeys in such a way as to avoid contamination of the oropharynx but to permit thorough exposure of the gastro-intestinal mucosae. No clinical evidence of poliomyelitic infection appeared. 3. Subsequent application of small amounts of virus to the tongues of 18 of the same monkeys caused paralytic poliomyelitis in one of them. 4. Virus given subsequently by enema to 11 of the monkeys caused no clinical manifestations of poliomyelitis. 5. Of 7 monkeys later treated with virus by oronasal spraying, one developed typical preparalytic signs of infection, and the distribution of lesions indicated that entry had occurred through the afferent nerves of the oropharynx and, possibly, the esophagus. 6. The 6 surviving monkeys were exposed to virus by inhalation. One of them developed paralytic poliomyelitis by olfactory entry. The others appeared to have acquired some resistance to infection. 7. The 5 surviving monkeys were inoculated intracerebrally, as a test of immunity. One of them developed paralytic poliomyelitis. The other 4 showed no clinical signs of infection, but all had typical lesions of varying extent and intensity in the central nervous system. 8. A histological examination of the peripheral nervous ganglia in 12 of the exposed monkeys sacrificed at various stages of the experiments revealed lesions compatible with poliomyelitis in all. Ganglia connected with the head alone (Gasserian, cervical sympathetic) were more constantly and, on the average, more severely involved than the celiac, which is connected only with the intestine. 9. While the celiac ganglion was involved in 7 cases, no evidence was found of the spread of infection from it to the spinal cord. PMID- 19871346 TI - POLIOMYELITIS IN THE CYNOMOLGUS MONKEY : II. RESISTANCE TO SPREAD OF INFECTION IN THE CENTRAL NERVOUS SYSTEM FOLLOWING EXPOSURES OF THE MUCOUS MEMBRANES TO VIRUS, WITH COMMENTS ON NON-PARALYTIC POLIOMYELITIS. AB - 1. Repeated non-traumatic exposures to poliomyelitis virus of the mucous membranes of the upper respiratory tract and of various portions of the alimentary tract in 5 cynomolgus monkeys, extending over a period of 9 to 14 months, were followed by a definite, though limited resistance to intracerebral inoculation to the homologous strain of virus in 4 of them. Only one monkey developed paralysis (20 per cent incidence) and the other 4 remained free of signs and symptoms of the disease. 92 per cent of 25 previously untreated monkeys developed paralysis with the same strain after intracerebral inoculation. 2. Microscopic examination of the central and peripheral nervous systems of the 4 non-paralytic cases revealed in all instances typical lesions in the central nervous system descending from the level of inoculation into the brain-stem but in only 2 into the spinal cord and then only in limited, small areas. Lesions were found in the peripheral ganglia in all animals which corresponded in distribution with the surface membranes previously exposed to virus. No lesions were found in the central nervous system indicative of invasion preceding the intracerebral inoculation. 3. Our observations point to the acquisition by the immune animal, as a result of surface exposure, of the power to limit the spread of infection in the central nervous system rather than of the capacity entirely to prevent implantation and multiplication of virus. 4. This limitation of spread, it is suggested, resembles the tendency so commonly seen in human poliomyelitis of the disease to "halt" at some stage of its evolution, resulting in the various clinical gradations in extent and severity of involvement (subclinical, abortive, non-paralytic, mild paralytic forms, etc.) 5. The experimental methods of exposure, previous to intracerebral inoculation, employed in our study are compared with the natural exposures of human beings during the course of life, which, as age advances, lead to increasing resistance to poliomyelitis and to an increasing incidence of specific neutralizing antibodies in the blood. 6. The mechanism of resistance is obscure. It may be related to the continuing presence of infection in the peripheral ganglia but this is as yet unproved. PMID- 19871347 TI - BIOCHEMICAL STUDIES ON SHOCK : II. THE ROLE OF THE PERIPHERAL TISSUES IN THE METABOLISM OF PROTEIN AND CARBOHYDRATE DURING HEMORRHAGIC SHOCK IN THE RAT. AB - The changes in the blood levels of amino nitrogen, glucose, lactate, and pyruvate were compared in eviscerate (liverless) rats and eviscerate rats subjected to hemorrhage, in order to establish the role of the peripheral tissues in the blood changes during shock. It was found that:- 1. The blood amino acids accumulate at a more rapid rate in the bled liverless rats than in the control liverless animals. 2. The blood sugar falls more rapidly in the liverless rat after hemorrhage, both in animals with intact suprarenal glands and those with enucleated suprarenal medullae. 3. The blood lactate and pyruvate rise slowly in the liverless rat, but maintain a constant relation to each other except terminally when convulsions occur. In the bled liverless rat both lactate and pyruvate increase much more rapidly than in the control liverless rat, and the lactate/pyruvate ratio also increases. These data are interpreted to indicate that a decrease in liver function during hemorrhagic shock serves to make apparent a considerable increase in peripheral protein catabolism and accentuates the effects of an increased carbohydrate utilization by the periphery. The lactate and pyruvate changes are determined chiefly by anoxia of the peripheral tissue and probably indicate an increasing predominance of anaerobic over aerobic metabolism of carbohydrate in muscle. The liver plays a negligible role in the lactate and pyruvate changes in shock. PMID- 19871348 TI - THE SEROLOGICAL DIAGNOSIS OF RELAPSING FEVER. AB - 1. Spirochetes of relapsing fever have been separated from the blood of heavily infected mice and rats by hemolysing with saponin, followed by repeated washing of the spirochetal suspension with physiological saline. 2. Spirochetes obtained in this manner appear to have broad antigenic specificity. Antigens of this type fixed complement in the presence of serum obtained from man or animals infected with one or other of the recognized strains or "species" of relapsing fever spirochetes. Macroscopic agglutination of the antigens likewise was observed with sera from the same sources. 3. Positive serological reactions were not observed with convalescent sera obtained following infection with other diseases, for example, typhus fever, malaria, Rocky Mountain spotted fever, Weil's disease, syphilis, and typhoid fever. Hyperimmune sera prepared against other pathogens also failed to react with the relapsing fever antigens. 4. No apparent change in the antigen occurred following storage in the ice box for as long as 4 months. 5. The results indicate that treatment of the spirochetes of relapsing fever with saponin yields a relatively stable antigenic preparation which may prove useful in the serological diagnosis of this disease. PMID- 19871349 TI - BIOCHEMICAL STUDIES ON SHOCK : IV. THE OXYGEN CONSUMPTION OF LIVER AND KIDNEY TISSUE FROM RATS IN HEMORRHAGIC SHOCK. AB - 1. With increasing severity of shock following hemorrhage in fasted rats there is an increasing depression in the rate of oxygen uptake, in oxygen, of liver slices from the bled animals. The respiration of kidney tissue is only slightly depressed even in severe states of shock. 2. The rates of oxygen uptake of liver tissue from bled rats are nicely correlated with the increases in blood amino nitrogen that follow severe hemorrhage. 3. A supplement of coenzyme factors, in the form of a hot water extract of normal rat liver, increases the oxygen uptake of liver tissue from rats in mild shock, but is without effect on the respiration of liver slices from rats in moderate or severe shock. 4. The ability of rat liver to oxidize succinate is not impaired even in severe shock, but the extra oxygen uptake does not improve the basal rate of respiration of the tissue. 5. Effects on the rate of oxygen uptake of normal rat liver slices comparable to those seen after hemorrhage could be produced by exposing the tissue to an atmosphere of nitrogen for periods of 15 and 60 minutes. This treatment had more marked effects on the respiration of kidney slices than are found after hemorrhage, but the kidney, unlike the liver, exhibited a marked degree of recovery in the presence of glucose. 6. The significance of these findings is briefly discussed. PMID- 19871350 TI - FATAL MURINE TYPHUS INFECTION IN THE dba STRAIN OF MICE, WITH OBSERVATIONS ON STRAIN VARIATION IN SUSCEPTIBILITY. AB - Injected intracranially in the dba strain of mice, murine typhus rickettsiae caused a serially transmissible meningoencephalitis similar to that produced by psittacosis and certain other viruses. All injected mice of this strain suddenly became ill and approximately half of these animals died on the 5th and 6th days after injection. Swiss mice injected in parallel series showed illness in only a few animals, and no deaths occurred. These experiments were carried out at room temperatures ranging from 60-80 degrees F. After intraperitoneal injection, a uniformly fatal rickettsial peritonitis developed in all dba mice kept at environmental temperatures of 65-73 degrees F. or 70-80 degrees F. Death occurred between the 3rd and 7th days after injection, depending somewhat on the dosage used. Among Swiss, brown agouti, and A albino mice injected in parallel series, the mortality was less than 60 per cent. These experiments indicate that mice of the dba strain are much more susceptible to murine typhus than are mice of the other three strains studied. PMID- 19871351 TI - VARIATION IN MORBIDITY AND MORTALITY OF MURINE TYPHUS INFECTION IN MICE WITH CHANGES IN THE ENVIRONMENTAL TEMPERATURE. AB - Murine typhus rickettsiae injected intraperitoneally in mice of the dba strain caused a uniformly fatal rickettsial peritonitis if the animals were kept at a room temperature ranging from 65-73 degrees F. or from 70-80 degrees F. With an environmental temperature range of 85-98 degrees F., a mortality of less than 25 per cent was observed. By utilizing different strains of mice and controlling the environmental temperature, conditions may be created under which murine typhus will have any desired degree of mortality. Such conditions have obvious advantages for the evaluation of therapeutic measures in typhus infection. PMID- 19871352 TI - RELATIONSHIP OF THE VIRUS OF LOUPING ILL IN SHEEP AND THE VIRUS OF RUSSIAN SPRING SUMMER ENCEPHALITIS IN MAN. AB - An experimental study of three strains of Russian spring-summer encephalitis virus and one of louping ill virus has yielded the following results:- 1. The sera of mice hyperimmunized to the viruses of Russian encephalitis and louping ill respectively have produced complement fixation with both antigens in almost precisely the same titer. 2. In neutralization tests hyperimmune sera against the Russian virus strains protected against louping ill virus to the same extent as against the Russian virus strains. Conversely, hyperimmune sera against the louping ill virus protected against the Russian viruses, although to a less degree than against louping ill virus. 3. In cross-resistance tests in mice, a vaccine consisting of formolized Russian virus gave strong protection against this latter and moderate protection against louping ill virus. Formolized louping ill virus gave moderate protection against infection with louping ill and considerably less against the Russian virus. 4. Serum from an individual recovered from a laboratory infection with louping ill virus contracted in 1933 gave positive complement fixation and neutralization tests with the Russian spring-summer encephalitis, as well as with louping ill virus. 5. Serum from a patient who became infected with either Russian or louping ill virus or both while working with the viruses in the laboratory in the fall of 1942, gave positive reactions on complement fixation and neutralization tests against them both. 6. No such similarities have been found with other central nervous system viruses. Hence it would appear that they are specific. PMID- 19871353 TI - FURTHER LABORATORY STUDIES ON THE CLASSIFICATION OF PSITTACOSIS-LIKE AGENTS. AB - 1. It was demonstrated by pathogenicity and latency tests in mammals and birds that variations exist among a group of viruses, isolated from several sources and producing coccoid elementary bodies resembling those of psittacosis. 2. Active cross immunity tests emphasized these differences and confirmed their significance. 3. On the basis of the present experimental evidence the psittacosis-like viruses causing atypical pneumonia in man may be classified into three groups: psittacosis, ornithosis, and human pneumonitis (strain S-F) of undetermined origin. PMID- 19871354 TI - STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : II. THE OCCURRENCE OF STRAINS IN A GIVEN TYPE CONTAINING M BUT NO T ANTIGEN. AB - 1. Group A hemolytic streptococci have been described which do not agglutinate in anti-T serum because they lack T antigen. 2. Other strains occur which contain T antigen yet do not agglutinate in anti-T serum because T agglutination is blocked by the presence of large amounts of M substance in the streptococci. 3. Strains belonging to a number of types have been analyzed to determine their antigenic composition with respect to M and T antigens. PMID- 19871355 TI - STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : III. TYPES WITH SEROLOGICALLY IDENTICAL M BUT DISTINCT T ANTIGENS: TYPES 10 AND 12. AB - 1. In this study a series of experiments showing the antigenic relationship of type 10 and type 12 group A hemolytic streptococci is reported. Agglutinin, precipitin, and passive protection tests with unabsorbed and reciprocally absorbed antisera were employed to show that representative type 10 and 12 strains contain serologically identical M antigens but unrelated type-specific T antigens. 2. Twenty-three other strains of group A hemolytic streptococci previously classified as either type 10 or type 12, collected from various sources, were shown to have an antigenic composition similar to one or the other of the two representative type strains. 3. The relationship of the two specific antigens, M and T, must be considered when any method employing the agglutinin reaction for the typing of group A hemolytic streptococci is used. PMID- 19871356 TI - BIOCHEMICAL STUDIES ON SHOCK : III. THE ROLE OF THE LIVER AND THE HEPATIC CIRCULATION IN THE METABOLIC CHANGES DURING HEMORRHAGIC SHOCK IN THE RAT AND THE CAT. AB - 1. In a series of rats subjected to hemorrhage and shock a high negative correlation was found between the portal and peripheral venous oxygen saturations and the arterial blood pressure on the one hand, and the blood amino nitrogen levels on the other, and a high positive correlation between the portal and the peripheral oxygen saturations and between each of these and the blood pressure. 2. In five cats subjected to hemorrhage and shock the rise in plasma amino nitrogen and the fall in peripheral and portal venous oxygen saturations were confirmed. Further it was shown that the hepatic vein oxygen saturation falls early in shock while the arterial oxygen saturation showed no alteration except terminally, when it may fall also. 3. Ligation of the hepatic artery in rats did not affect the liver's ability to deaminate amino acids. Hemorrhage in a series of hepatic artery ligated rats did not produce any greater rise in the blood amino nitrogen than a similar hemorrhage in normal rats. The hepatic artery probably cannot compensate to any degree for the decrease in portal blood flow in shock. 4. An operation was devised whereby the viscera and portal circulation of the rat were eliminated and the liver maintained only on its arterial circulation. The ability of such a liver to metabolize amino acids was found to be less than either the normal or the hepatic artery ligated liver and to have very little reserve. 5. On complete occlusion of the circulation to the rat liver this organ was found to resist anoxia up to 45 minutes. With further anoxia irreversible damage to this organ's ability to handle amino acids occurred. 6. It is concluded that the blood amino nitrogen rise during shock results from an increased breakdown of protein in the peripheral tissues, the products of which accumulate either because they do not circulate through the liver at a sufficiently rapid rate or because with continued anoxia intrinsic damage may occur to the hepatic parenchyma so that it cannot dispose of amino acids. PMID- 19871357 TI - STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : IV. RELATED T BUT DISTINCT M ANTIGENS IN TYPES 15, 17, 19, 23, 30, AND IN TYPES 4, 24, 26, 28, 29, 46. IDENTIFICATION BY SLIDE AGGLUTINATION. AB - 1. The occurrence of closely related T antigens in the series composed of types 15, 17, 19, 23, and 30 accounts for most of the cross reactions observed among these types. Similarly T antigens, unrelated to the first series but mutually related, occur in a second series comprising types 4, 24, 26, 28, 29, and 46. 2. Matt variants of each of the eleven types studied possess type-specific M antigens demonstrable either by precipitin or agglutinin reactions. 3. In seven of these types, strains have been encountered which do not possess the T antigen usually associated with the type in question. 4. Procedures are outlined in the appendix for preparing specific antisera for the classification of these types by the slide agglutination technique. PMID- 19871358 TI - DEPRESSION OF ANAEROBIC GLYCOLYSIS OF EMBRYONIC TISSUE BY WESTERN STRAIN OF EQUINE ENCEPHALOMYELITIS VIRUS. PREVENTION OF THIS EFFECT BY SPECIFIC IMMUNE SERUM. AB - Studies were made on the effect of mixing the Western strain of equine encephalomyelitis virus (W.E.E.) and embryonic tissue on the rate of anaerobic glycolysis of the tissue. Whole chick embryo, chick embryo from which brain and spinal cord had been removed, and embryonic skeletal muscle were employed. 1. W.E.E. virus depressed the rate of anaerobic glycolysis of embryonic tissues within 2 days after its addition to the tissue. The decrease in anaerobic glycolysis varied from 17 to 82 per cent and was apparent 2 to 4 days after the addition of the virus. No significant effect of the virus was observed 4 hours and 6 days after mixing it with the tissue. 2. Anti-W.E.E. immune serum prevented the inhibiting action of W.E.E. virus on the anaerobic glycolysis of embryonic skeletal muscle. PMID- 19871359 TI - STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES : INDUCTION OF TRANSFORMATION BY A DESOXYRIBONUCLEIC ACID FRACTION ISOLATED FROM PNEUMOCOCCUS TYPE III. AB - 1. From Type III pneumococci a biologically active fraction has been isolated in highly purified form which in exceedingly minute amounts is capable under appropriate cultural conditions of inducing the transformation of unencapsulated R variants of Pneumococcus Type II into fully encapsulated cells of the same specific type as that of the heat-killed microorganisms from which the inducing material was recovered. 2. Methods for the isolation and purification of the active transforming material are described. 3. The data obtained by chemical, enzymatic, and serological analyses together with the results of preliminary studies by electrophoresis, ultracentrifugation, and ultraviolet spectroscopy indicate that, within the limits of the methods, the active fraction contains no demonstrable protein, unbound lipid, or serologically reactive polysaccharide and consists principally, if not solely, of a highly polymerized, viscous form of desoxyribonucleic acid. 4. Evidence is presented that the chemically induced alterations in cellular structure and function are predictable, type-specific, and transmissible in series. The various hypotheses that have been advanced concerning the nature of these changes are reviewed. PMID- 19871360 TI - A VIRUS CAUSING PNEUMONIA IN CATS AND PRODUCING ELEMENTARY BODIES. AB - From a contagious respiratory disease of cats an agent has been transmitted to mice, rabbits, guinea pigs, hamsters, and embryonated eggs. When inoculated intranasally into cats, it produces a disease like that seen in the naturally infected animals. Parenteral injection causes only a mild fever. From cats killed during acute illness, the agent was demonstrated regularly in the discharges from the eyes and nose and in the pneumonic lung but not in other organs. The agent can be demonstrated in the nasal mucosa of cats 1 to 2 months after injection. Cultures of egg yolk sac containing the agent showed no growth, and cultures of active lung suspensions were usually negative, such positive findings as were obtained being due to respiratory contaminants. Attempts to pass the agent through Berkefeld N filters were generally unsuccessful. Stained preparations of egg yolk sac membranes and of infected mouse or hamster lungs showed typical elementary bodies. Centrifuge experiments showed that the agent and the bodies sedimented at the same rate. Complement fixation experiments using a suspension of partially purified bodies as antigen were negative with control sera and positive with sera from recovered cats. It is concluded that the respiratory disease of cats is due to a virus that forms elementary bodies. PMID- 19871361 TI - A STUDY OF CONDITIONS FOR THE OPTIMUM PRODUCTION OF PR8 INFLUENZA VIRUS IN CHICK EMBRYOS. AB - In order to determine the conditions for the optimum production of PR8 influenza virus in chick embryos, a study has been made of the roles of concentration of virus in the inoculum, temperature of incubation of infected embryos, length of time of incubation of infected embryos, and age of embryos at the time of inoculation. Relative amounts of virus in different preparations were measured indirectly by means of determinations of chicken red blood cell agglutination titers. Frozen infectious allantoic fluid which produced infection in chick embryos at a maximum dilution of 10(-7) was employed as a stock inoculum. Best results were obtained with an amount of stock inoculum of 0.1 cc. of a 10(-5) dilution, a temperature of incubation of 35 degrees C., a length of time of incubation of 36 to 48 hours, and with embryos brought to 10 or 11 days of age at 37 degrees C. or 9 or 10 days of age at 39 degrees . An uncontrolled factor arising from inherent variations in the properties of different embryos and different batches of embryos was discussed. PMID- 19871362 TI - QUANTITATIVE ASPECTS OF THE RED BLOOD CELL AGGLUTINATION TEST FOR INFLUENZA VIRUS. AB - A detailed study has been made of the nature of the variables inherent in the chicken red cell agglutination test for influenza virus in an effort to obtain a method of measurement of biological activity of sufficient accuracy that it might be employed as a reliable index of chemical purity of preparations of the virus. It was found that the temperature at which the test is conducted has a marked effect on the titer, whereas within the range of pH 6-8 the pH has a negligible effect. It was also found that a variation in results may be encountered due to a variation in the specific behavior of red cells from different chickens and to an instability of the red cells themselves. Preparations of purified influenza virus held at 4 degrees C., on the other hand, were found to be stable with respect to chicken red cell agglutinating activity for several months. This fact, together with the fact that in duplicate measurements upon different samples the accuracy was such that the chances were 19 out of 20 that differences of 8.4 per cent in the mean end points were significant, made it possible to establish a reproducible standard of CCA activity based on a unit weight of purified virus material. As a result, it was possible to devise a standardized procedure for carrying out with high accuracy quantitative measurements of influenza virus. PMID- 19871363 TI - THE MOUSE INFECTIVITY TITRATION OF INFLUENZA VIRUS. AB - A study has been made to establish the statistical significance of results obtained in mouse infectivity titrations of influenza virus. Five titrations, each composed of five replicas, were carried out and 50 per cent end points were calculated for each titration. Three criteria for evaluating the end points were employed, namely, the presence or absence of pulmonary lesions, the occurrence of death, and a weighted composite taking into account both the extent of lung consolidation and the occurrence of death. Standard deviations of the distribution of end points obtained by each method were computed, and from these data levels of probabilities for significance in the differences between end points were determined. It was found that the chances are 19 out of 20 that differences of 0.99, 0.77, and 0.73 logarithmic units, respectively, for the lesion, the death, and the weighted end points are significant. PMID- 19871364 TI - THE ACTION OF CRYSTALLINE PROTEOLYTIC ENZYMES ON ANGIOTONIN. AB - Angiotonin was subjected to enzymatic digestion by crystalline carboxy-peptidase, chymotrypsin, trypsin, and pepsin. These enzymes were found to destroy it in vitro. Hydrogen ion optima and proteolytic coefficients for these reactions were determined and were found to be of approximately the expected magnitude for typical substrates. Regarding the purified crystalline enzymes as reagents, the experimental findings were interpreted on the basis of Bergmann's specificity studies. We were thus directed to the conclusion that angiotonin contains (1) a free terminal amino group, (2) a free terminal carboxyl group, (3) one basic amino acid residue which may be terminal but its carboxyl must be united in a peptide linkage, (4) one central dibasic amino acid residue in combination with an aromatic amino acid residue, (5) an aromatic amino acid residue which may be part of (4) and, if not part of (4) must be terminal with its carboxyl group in peptide linkage. The simplest compound satisfying these conditions is tyrosyl arginylglutamyl-phenylalanine or a combination of amino acids with similar general characteristics. PMID- 19871365 TI - THE RENAL PATHOLOGY OF NUTRITIONAL HYPERTENSION IN RATS. AB - Rats subsisting on a diet partially deficient in the heat-stable fractions of the vitamin B complex are known to experience a rise in blood pressure. The present study shows that after prolonged administration of this dietary, abnormal structural changes occur in the kidneys. The surface of this organ becomes finely granular. The afferent arterioles show degenerative changes, consisting of irregular subendothelial hyaline deposits which encroach on the lumen. The interlobular arteries undergo the same change, plus degeneration of the media; the lumen of these vessels is likewise compromised. Resultant, small, streak-like areas of ischemic atrophy occur in both cortex and medulla, with necrosis of the epithelial lining of the uriniferous tubules. The glomeruli are reduced in size, the number of their component loops decreased, their pattern simplified, and the capillary basement membrane thickened. In addition to these changes, kidneys from animals on a more profoundly deficient diet display numerous areas of hemorrhagic infiltration in the cortical and subcapsular regions. The possible identity of these lesions with those seen in essential hypertension in man is discussed. PMID- 19871366 TI - THE EFFECT OF VITAMIN B(1) DEFICIENCY AND OF RESTRICTED FOOD INTAKE ON THE RESPONSE OF MICE TO THE LANSING STRAIN OF POLIOMYELITIS VIRUS. AB - In several experiments it was shown that a deficiency of vitamin B(1) in the diet increased the resistance of mice to the Lansing strain of poliomyelitis. The source of the virus was a suspension of infected mouse brain in saline, which was injected intracerebrally. Both the mortality rate and the incidence of paralysis were lower in the deficient animals than in the normally fed controls. The protection was more pronounced with respect to paralysis than with respect to the number of deaths. Some deaths in the deficient groups were undoubtedly due to the vitamin deficiency, as indicated by numerous deaths among groups of animals which were given the deficient diet but injected with a suspension of normal brain. An attempt was made to maintain a state of chronic vitamin deficiency by giving small amounts of the vitamin. The results also seem to indicate that the effect of the deficiency was more in delaying the action of the virus than in preventing it. The greatest difference between normally fed and deficient animals receiving the virus came at about the 12th day after inoculation. Comparable results were obtained by restricting the intake of the complete diet to 1 gm. per mouse per day, which is about 40 per cent of the intake of the normally fed mice. Restriction of the caloric intake alone gave similar results. Restriction of food intake was effective in experiments in which extra vitamin B(1) was given in the diet and also when a diluted saline solution was given by stomach tube to assure a sufficient intake of fluid. Other data are necessary before an explanation can be given for the manner in which these deficiencies increase the resistance of the mice to the virus of poliomyelitis. PMID- 19871367 TI - HEREDITY OF THE Rh BLOOD TYPES. AB - Data are presented concerning the Rh blood types in 97 families with 275 children and in 135 mother-child combinations. The results obtained are in complete agreement with the theory of six allelic genes. When the theory is tested by applying the chi square and gene frequency methods to data on the distribution of the Rh types in the population, the agreement is also satisfactory. The practical implications of the findings are discussed. PMID- 19871368 TI - AN EVALUATION OF METHODS FOR THE CONCENTRATION AND PURIFICATION OF INFLUENZA VIRUS. AB - The concentration and purification of influenza virus by means of differential centrifugation in a vacuum type centrifuge, by adsorption on and elution from adult chicken red cells, by elution of the precipitate formed on freezing and thawing of allantoic fluid, by adsorption on and elution from embryonic chick red cells, and by combinations of the first method with each of the three succeeding methods, have been studied. Over-all yields of virus of about 50 to 70 per cent were obtained by these methods and combinations of methods except for somewhat lower yields when adsorption on and elution from adult chicken red cells was employed. However, the purified products obtained by methods involving only the use of red cells or the freezing and thawing technique were found to contain about 80 per cent of non-virus protein. The purified products obtained when differential centrifugation was used either alone or in combination with any one of the other methods were found to be indistinguishable and to consist of a fairly homogeneous component having a sedimentation constant of about 600 S. Such preparations possessed about 22,000 chicken red cell agglutinating units per mg. of protein nitrogen and solutions containing only about 10(-14) gm. of the materials gave 50 per cent infectivity end points in chick embryos. The Sharples centrifuge was found to be almost as efficient as the vacuum type centrifuge for the concentration and purification of influenza virus and, because of its larger capacity, is recommended for the preparation of purified virus on a large scale. PMID- 19871369 TI - THE SIZE OF INFLUENZA VIRUS. AB - The sedimentation behavior of influenza virus in dilute solutions of electrolyte was found to be quite variable. At times the virus activity appeared to sediment at a rate comparable with that of particles about 80 to 120 mmicro in diameter, at other times at a rate comparable with that of particles about 10 mmicro in diameter, and at still other times the bulk of the activity appeared to sediment at a rate comparable with that of the larger particles and the residual activity at a rate comparable with that of the smaller particles. However, in the presence of a sucrose density gradient, the virus activity was always found to sediment with a rate comparable to that of particles about 80 to 120 mmicro in diameter; hence it appeared that the variable sedimentation behavior in dilute electrolyte solution was due to convection or mechanical disturbances during centrifugation. About 30 per cent of the high molecular weight protein present in the allantoic fluid of chick embryos infected with the F 12 strain of influenza virus was found to consist of a component having a sedimentation constant of about 30 S, and hence a probable particle diameter of about 10 mmicro. The residual protein of high molecular weight was present in the form of a component having a sedimentation constant of about 600 S, and hence a probable particle diameter of about 70 mmicro. The proportion of the 30 S component in allantoic fluid of chick embryos infected with the PR8 strain of influenza virus was found to be considerably less. The 600 S and 30 S components of F 12 allantoic fluid were purified and separated by differential centrifugation. The purified preparations of the 600 S component were found to possess a specific virus activity from 100 to over 10,000 times that of the purified preparations of the 30 S component, the difference in activity apparently depending only on the degree of fractionation of the two components. The purified 30 S component was found to sediment normally in the presence of 12 per cent sucrose, whereas the small residual virus activity of such preparations was found to sediment in the presence of a sucrose density gradient with a rate comparable to that of much heavier particles. It is concluded that influenza virus activity is not associated with material having a particle diameter of about 10 mmicro, but is associated solely with material having a sedimentation constant of about 600 S and hence a probable particle diameter of about 70 mmicro. PMID- 19871370 TI - THE STABILITY OF INFLUENZA VIRUS IN THE PRESENCE OF SALTS. AB - The stability of centrifugally purified PR8 influenza virus at pH 7 in 0.001, 0.01, 0.1, and 1.0 M phosphate buffers, in veronal and borate buffers, and in adjusted solutions of saline and distilled water was investigated. The results demonstrate that the stability of this virus can vary considerably at pH 7 depending upon the nature and concentration of the salts present. Borate, veronal, and phosphate buffers at a concentration of about 0.1 M showed almost equal ability to maintain virus activity over several weeks of time at 4 degrees C. In many cases, it may prove inconvenient to use veronal buffer, however, because of the difficulty in determining protein concentration in its presence. The 0.1 M phosphate buffer has proved in tests not described here to be slightly more consistent in preserving virus activity than the borate and may, therefore, be considered slightly superior to the latter. It is apparent that unbuffered saline is a poor solvent for preserving virus activity regardless of pH. The activity of partially inactivated virus in distilled water and in saline solutions was increased ten to 1000 times by diluting such solutions with 0.1 M phosphate buffer. Some reactivation was also effected with veronal but not with borate buffers. PMID- 19871371 TI - THE EFFECT OF SOME CHEMICALS ON PURIFIED INFLUENZA VIRUS. AB - A study was made of the effect of 0.05 and 0.5 N solutions of 20 different chemicals on the activity of purified PR8 influenza virus in 0.1 M phosphate buffer. It was found by tests in chick embryos and in mice that virus activity was destroyed by strong oxidizing agents such as iodine, by salts of heavy metals, by mercurochrome, by formaldehyde, and by the detergents phemerol, roccal, and sodium dodecyl sulfate. Reducing agents appeared to have little if any inactivating effect with the exception of 0.05 N ascorbic acid. At the concentrations tested, sulfathiazole sodium exerted only a weak inactivating effect. 0.5 N phenol inactivated the virus promptly, but solutions of the strength more commonly used for bactericidal purposes were only weakly virucidal. The virus appeared relatively unaffected by glucose, ammonium sulfate, calcium chloride, sodium thiosulfate, and arginine. PMID- 19871372 TI - CENTRIFUGATION AND ULTRAFILTRATION STUDIES ON ALLANTOIC FLUID PREPARATIONS OF INFLUENZA VIRUS. AB - A synthetic density gradient technique has been applied to the study of the PR8 and Lee strains of influenza virus in the angle centrifuge. The method counteracted convective disturbances and permitted about a fiftyfold improvement in clearing supernatant fluids of virus. Sedimenting boundaries of infective virus particles, hemagglutinin, and complement-fixing antigen were obtained in the angle centrifuge and correlated with boundaries observed optically in the ultracentrifuge. The sedimentation constant of infective Lee virus particles is approximately 800 Svedberg units, while that of PR8 virus is only about 700. On the assumption of spherical shape, these values correspond to approximate diameters of 85 and 80 mmicro respectively. These values agree with those obtained by filtration with graded collodion membranes. The concentration of primary virus particles in untreated allantoic fluid preparations of PR8 or Lee virus is of the order of 0.01 per cent. The primary infective particles are identical with the hemagglutinin and the complement-fixing antigen to a large extent. However, allantoic fluid preparations of PR8 virus also show a slightly inhomogeneous group of particles with an average sedimentation constant of 460 S, which are adsorbed by and eluted from red blood cells yet appear to be non infective. In addition the virus preparations contain a small amount of "soluble antigen" which sediments more slowly than the virus and is not adsorbed by red blood cells. This soluble antigen is probably associated with material which was observed optically in the ultracentrifuge to sediment at rates ranging from very low values up to that characteristic of the primary virus boundary. This distribution of rate makes it seem likely that the material represents disintegrated virus particles. Calculations based on the experimental results obtained indicate that of the order of 10 influenza virus particles are required to produce infection of chick embryos or mice with the PR8 virus. While a comparable number is required with Lee virus for infection of chick embryos, about 10,000 particles are necessary for infection of mice. The ratio of hemagglutinin to red blood cells required to produce 50 per cent agglutination with dilute virus suspensions in the standard test is roughly 1. PMID- 19871373 TI - THE ROLE OF THE MUCOID POLYSACCHARIDE (HYALURONIC ACID) IN THE VIRULENCE OF GROUP A HEMOLYTIC STREPTOCOCCI. AB - 1. A quantitative turbidimetric method for the estimation of hyaluronidase activity, based on the ability of the enzyme to decrease the capacity of the polysaccharide to precipitate acidified protein has been developed. Two units of hyaluronidase, by this method, are equivalent to one viscosity-reducing unit. 2. Hyaluronidase added to a phagocytic system containing defibrinated human blood, immune or non-immune, greatly increases the rate of phagocytosis of group A streptococci. Phagocytosis of Type I pneumococci is not affected by hyaluronidase under the same conditions. 3. The bactericidal activity of non-immune blood against group A streptococci is increased by hyaluronidase; the activity of immune blood is, however, somewhat inhibited by the enzyme. Killing of pneumococci is not affected by the presence of the enzyme. 4. Mice can be protected against group A streptococcal infection by frequent treatment with 200 turbidity-reducing units of hyaluronidase; the protective action of the enzyme is removed by heating at 60 degrees C. for 1 hour. Mice infected with Type I pneumococcus and treated with hyaluronidase die somewhat sooner than the untreated controls. PMID- 19871374 TI - PARA-AMINOBENZOIC ACID PRODUCTION BY STAPHYLOCOCCI. AB - 1. Strains of staphylococci produce diazotizable materials which can be converted to a dye, and the intensity of the color reaction can be quantitated in the same manner as p-aminobenzoic acid. The sulfonamide-resistant strains which we have studied produce more diazotizable substance than non-resistant strains. 2. The development of a color by the diazotizable substance can be inhibited by exposing the substance to a soil bacillus (Mirick) specifically adapted to oxidize PABA. 3. The diazotizable substance produced by staphylococci inhibits the anti staphylococcic action of sodium sulfathiazole to approximately the same degree as equivalent amounts of pure p-aminobenzoic acid. 4. Two microbiological methods for assaying p-aminobenzoic acid were employed for quantitating the amount of this material produced by staphylococci. In general, the sulfonamide-resistant strains produced more p-aminobenzoic acid than the sulfonamide-sensitive strains. The inconstant results obtained with these biological assays are discussed. PMID- 19871375 TI - IMMUNOLOGICAL RELATIONSHIPS AMONG CENTRAL NERVOUS SYSTEM VIRUSES. AB - From observations carried out with the viruses of Russian spring-summer encephalitis, louping ill, W.E.E., and the Japanese B, St. Louis, and West Nile types of encephalitis, the following facts and inferences have been derived. 1. Russian encephalitis and louping ill viruses showed a close relationship by complement fixation, neutralization, and intraperitoneal cross-resistance tests. Intracerebral cross-resistance tests, on the other hand, failed to reveal any connection between them. Neither Russian nor louping ill virus appeared to be related to the remaining viruses tested. 2. Japanese B, St. Louis, and West Nile types of encephalitis, as a group, showed a certain degree of group relationship, but it was not so close as that between the Russian and louping ill viruses. In complement fixation tests, besides homologous reactions, Japanese serum brought about reactions with both St. Louis and West Nile antigens; St. Louis serum reacted with Japanese antigen, and West Nile serum with Japanese antigen. In neutralization tests with mouse sera, no relationship was found amongst these three viruses, while in similar tests with either hamster or guinea pig serum, which gave higher homologous titers,-it was found that Japanese serum protected against West Nile and St. Louis viruses, St. Louis serum protected against West Nile virus, and West Nile serum against Japanese virus. In intracerebral and intraperitoneal cross-resistance tests, no relationship was found to exist between these three viruses. Moreover, the Japanese B, St. Louis, and West Nile viruses appeared to be unrelated to any one of the three other viruses tested. 3. W.E.E. virus stood apart in all tests as unrelated to any of the other viruses studied. 4. The homologous titers of complement-fixing antibodies in mouse sera showed a gradual decline with the passing of time after vaccination, and this loss of homologous titer was paralleled by a similar drop in the titer of the heterologous reactions. In the case of the Japanese B, St. Louis, and West Nile viruses, with which at the start the amount of crossing was not high, a point was reached beyond which heterologous reactions could no longer be detected. 5. A comparison of the specific levels of complement-fixing and neutralizing antibodies for the viruses in mouse hyperimmune sera showed their rate of persistence to differ. Complement-fixing antibodies which had highest titers on the 10th day, diminished gradually until, when tested on the 50th day, all titers had reached levels from one-fourth to one-eighth of their values on the 10th day. On the other hand, the levels of neutralizing antibodies for the same samples of serum were, on the 50th day, as high as or higher than those found on either the 25th or 10th days, save in the case of the Japanese B virus. 6. The state of immunity of animals following vaccination with the viruses discussed was found to be different at a given time, depending on the method employed to determine it. Thus, mice vaccinated with St. Louis virus had positive complement-fixing antibodies on the 10th day and no neutralizing antibodies. The state of immunity changed in the course of time. For this reason it is felt that in order to detect whether two viruses are related or not, multiple observations are necessary, over a considerable time and employing all available methods of immune comparison. PMID- 19871376 TI - INTERFERENCE BETWEEN THE INFLUENZA VIRUSES : I. THE EFFECT OF ACTIVE VIRUS UPON THE MULTIPLICATION OF INFLUENZA VIRUSES IN THE CHICK EMBRYO. AB - Reciprocal interference between influenza A, influenza B, and swine influenza viruses has been demonstrated in the chick embryo. Certain temporal and quantitative factors which influence the production of interference in this host virus system have been studied. The implications of these observations in relation to the mechanism by which interference is produced are discussed. PMID- 19871377 TI - INTERFERENCE BETWEEN THE INFLUENZA VIRUSES : II. THE EFFECT OF VIRUS RENDERED NON INFECTIVE BY ULTRAVIOLET RADIATION UPON THE MULTIPLICATION OF INFLUENZA VIRUSES IN THE CHICK EMBRYO. AB - Influenza A or influenza B virus rendered non-infective by ultraviolet radiation was found to be capable of producing interference with the multiplication of active influenza viruses in the chick embryo. Certain temporal and quantitative relationships affecting the interference phenomenon with this host-virus system were studied. An hypothesis of the mechanism of interference between the influenza viruses is proposed and discussed. PMID- 19871378 TI - THE DURATION OF IMMUNITY TO PLASMODIUM KNOWLESI MALARIA IN RHESUS MONKEYS. AB - Rhesus monkeys with experimental Plasmodium knowlesi infections of varying duration were treated with sodium sulfathiazole to sterilize the infection and after differing lengths of time were reinoculated intraperitoneally with homologous strains of the plasmodium, for the purpose of determining whether there is any acquired immunity to malaria in hosts from whom all parasites have been removed. Two monkeys, one receiving sulfathiazole on the 2nd day of acute infection and the other on the 4th day, had no immunity at the time of reinoculation, 3 weeks and 10 weeks later, respectively. Both developed infections which followed the course usual in an acute attack in a normal monkey. In monkeys which survived acute infection with the aid of immune serum or quinine and in which a naturally acquired immunity had developed to the point where the acute infection was converted into a chronic one, there was an undoubted persistence of partial immunity up to about a year after sterilization of the infection with sulfathiazole, as indicated by recovery of reinoculated animals after mild or moderately severe infections differing widely in characteristics from the infection in the normal monkey. The end point at which immunity disappears seems to be independent of the length of the chronic infection. PMID- 19871379 TI - THERAPEUTIC EFFECTIVENESS OF PENICILLIN IN EXPERIMENTAL MURINE TYPHUS INFECTION IN dba MICE. AB - The administration of penicillin in relatively large but non-toxic doses to dba mice after injection with murine typhus rickettsiae resulted in a marked reduction in mortality, particularly when the initial dosage of rickettsiae was relatively small, approaching the minimal lethal dose. No evidence of secondary bacterial infection was obtained by bacteriological and histological studies, and it seems justifiable to conclude that the greatly increased survival rate in the treated mice was caused by the action of penicillin on typhus rickettsiae. The theoretical and practical implications of the results are discussed. PMID- 19871380 TI - BLOOD-SUCKING VECTORS OF ENCEPHALITIS: EXPERIMENTAL TRANSMISSION OF ST. LOUIS ENCEPHALITIS (HUBBARD STRAIN) TO WHITE SWISS MICE BY THE AMERICAN DOG TICK, DERMACENTOR VARIABILIS SAY. AB - (1) The common dog tick, Dermacentor variabilis, is capable of being infected with the virus of St. Louis encephalitis, Hubbard strain, by feeding on inoculated animals and, once infected, can transmit the virus to normal susceptible animals by bite. (2) A female can transmit the infection to her offspring, through all stages of metamorphosis of the 2nd generation into the 3rd generation. (3) Ticks infected under laboratory conditions and kept inactive at a temperature of 12.5 degrees C., remained infective for at least a period of 10 months. Eggs laid by an infected female and stored in a refrigerator (12.5 degrees C.) for 10 months retained infective virus, and larvae hatched from such eggs at the end of the 10 months of dormancy were also infective. (4) The present work, a preliminary account of which appeared in December, 1941 (1, 2), is of theoretical significance since in so far as we are aware, it represents the first successful transmission of St. Louis encephalitis to experimental animals by a blood-sucking vector. PMID- 19871381 TI - STUDIES ON THE DENATURATION OF ANTIBODY : I. THE ACTION OF UREA ON DIPHTHERIA ANTITOXIN. AB - Diphtheria antitoxin has been shown to be inactivated in the presence of urea. In 7.5 molar area at pH 7.82 nearly half the activity is destroyed in 24 hours, as measured by the neutralizing power of toxin. The reaction appears to be first order with respect to antitoxin, since the initial rate is independent of the antitoxin concentration, but the rate decreases rapidly with time. Higher or lower pH of the presence of M/10 sodium sulfite increases the antitoxin inactivation. The meaning of the results is discussed. PMID- 19871382 TI - STUDIES ON LYMPHOGRANULOMA VENEREUM : II. THE ASSOCIATION OF SPECIFIC TOXINS WITH AGENTS OF THE LYMPHOGRANULOMA-PSITTACOSIS GROUP. AB - Toxins, which resemble in most respects bacterial endotoxins, are associated with the agents of lymphogranuloma venereum, meningopneumonitis, and mouse pneumonitis as they grow in the yolk sac of the chick embryo. They are labile and are not readily separated from the bodies of the agent. They kill mice rapidly after intravenous, and in some cases after intraperitoneal, injection but the minimal lethal dose is relatively large and, in those freshly harvested yolk sacs which have been tested, has corresponded to about 36 million infective units. Characteristic lesions are produced in all mice except those which die very rapidly, and are found especially in the liver where necrosis of the midzone of the lobule occurs. Antitoxic sera which are effective against a few lethal doses of the toxin can be produced in rabbits or chickens by using either toxin or toxoid as antigen. Such sera behave in a manner analogous to antiendotoxins against bacterial endotoxins and they do not neutralize by the law of multiple proportions. Antitoxic sera can also be obtained from human beings convalescent from at least one of these diseases. The toxins and antitoxins appear to be highly specific and they may offer a useful tool in distinguishing between different members of this closely interrelated group. PMID- 19871383 TI - TITRATION OF INFLUENZA VIRUS IN CHICK EMBRYOS. AB - A study was made to establish the reproducibility of end points obtained in the titration of influenza viruses in chick embryos. Six tests were performed, each composed of five replicate titrations of a purified preparation of the PR8 strain of influenza virus. The data from these titrations were subjected to statistical analysis which revealed that the chances are 19 out of 20 that differences in end points of 0.37 and 0.62 logarithmic units are significant in titrations employing ten embryos and five embryos per dilution, respectively. Additional simultaneous titrations in embryos and in mice showed that chick embryos are sensitive to considerably smaller amounts of virus than are mice, and that the mouse titration is adversely affected by inactive virus under conditions which are without apparent influence on the embryo titration. PMID- 19871384 TI - ISOLATION FROM NORMAL MICE OF A PNEUMOTROPIC VIRUS WHICH FORMS ELEMENTARY BODIES. AB - 1. A pneumotropic virus which forms elementary bodies has been isolated from apparently normal albino Swiss mice. 2. The antigenic relationship of this virus to those of meningopneumonitis, lymphogranuloma venereum, hamster pneumonia (7), and human pneumonitis (8) was established either by cross-immunity or complement fixation or both. 3. In spite of a relationship to other viruses, the virus could be differentiated from all the others studied by certain of its properties. PMID- 19871385 TI - THE EFFECT OF CHEMICAL CARCINOGENS ON VIRUS-INDUCED RABBIT PAPILLOMAS. AB - The application of methylcholanthrene and tar to virus-induced papillomas of the domestic rabbit caused them to become carcinomatous with great rapidity, and the malignant changes were frequently multiple. In bringing on the cancers the chemical agents acted in their specific capacity as carcinogens, not as ordinary stimulants of cell proliferation. The cancers derived from the virus-infected cells and were of the same types as arise from these elements spontaneously after a much longer time. The evidence would seem to indicate that the chemical carcinogens acted by way of the virus. PMID- 19871386 TI - HETEROGENETIC ANTIBODIES IN ACUTE HEPATITIS. AB - A heterogenetic antibody showing fixation of complement with human liver and agglutination of sheep erythrocytes was found in certain cases of acute infective hepatitis. The antigen concerned in these reactions was apparently heat stable and alcohol soluble. Differences from other heterogenetic antigen-antibody systems have been noted. The possible relation of the heterogenetic antibody to liver damage was considered. PMID- 19871387 TI - EXPERIMENTAL EPIDEMIOLOGY OF TUBERCULOSIS : THE PREVENTION OF NATURAL AIR-BORNE CONTAGION OF TUBERCULOSIS IN RABBITS BY ULTRAVIOLET IRRADIATION. AB - 1. Ultraviolet irradiation of the air of a room exercises a protective influence against natural air-borne contagion of tuberculosis in rabbits. 2. When the radiant energy is of low intensity it reduces considerably the incidence of tuberculosis. (a) It completely protects rabbits of high natural resistance from acquiring demonstrable disease though they become tuberculin sensitive. (b) It fails to protect a small proportion of rabbits of low natural resistance from fatal tuberculosis. 3. When the radiant energy is of high intensity all rabbits, whether of high or of low natural resistance, are almost completely protected from a contagion so severe that it is fatal to the great majority of rabbits of the same genetic constitution not protected by these rays. The protected rabbits do not develop tuberculin sensitivity. 4. The contagion of tuberculosis in these studies is air-borne and the radiant energy exercises its protective influence by its bactericidal properties. It is probable that ultraviolet irradiation may control air-borne contagion of human tuberculosis. PMID- 19871388 TI - EXPERIMENTAL EPIDEMIOLOGY OF TUBERCULOSIS : HEREDITARY RESISTANCE TO ATTACK BY TUBERCULOSIS AND TO THE ENSUING DISEASE AND THE EFFECT OF THE CONCENTRATION OF TUBERCLE BACILLI UPON THESE TWO PHASES OF RESISTANCE. AB - 1. Hereditary resistance to attack by air-borne tubercle bacilli is distinct from the resistance to the ensuing disease. 2. One inbred rabbit family has little resistance to attack: by the microorganism but has considerable resistance against the ensuing disease. 3. Another inbred family has considerable resistance against attack by the tubercle bacillus but has little resistance against the ensuing disease. 4. Increasing concentrations of tubercle bacilli in the environment of the family of high genetic resistance to the disease increase the incidence of infection, accelerate the onset of the disease, and affect its essential character in proportion to the concentration of the microorganism. 5. Up to a certain concentration of tubercle bacilli in the environment of the families of low genetic resistance to the disease, increasing concentrations of the infectious agent also increase the incidence of the disease and accelerate its onset, although its anatomical character is always of a uniform rapidly progressive type. Beyond this concentration further increment of the infectious agent exercises no effect. PMID- 19871389 TI - THE RECOVERABILITY OF VIRUS FROM PAPILLOMAS PRODUCED THEREWITH IN DOMESTIC RABBITS. AB - By preliminary preparation of the skin in ways that render it hyperplastic the presence of infective virus can be demonstrated in extracts of domestic rabbit papillomas which yield no growths when inoculated by the ordinary methods and which for this reason have been supposed to contain no virus. The amount of virus recovered by the method outlined in the present work, however, is small when compared with the yield obtained in most instances from comparable cottontail rabbit papillomas. The yield is greatly influenced not only by the virus strain used to produce the growths but by the individual rabbit host. Although virus has been obtained from papillomas produced in domestic rabbits by all of the virus strains tested, a total of 21 thus far, only about one-fourth of these strains are readily to be procured again from the growths they cause and the others are demonstrable only in hosts in which the conditions are favorable for reasons unknown. An experimental comparison of the capacity of suspensions of papilloma tissue from domestic and cottontail rabbits to elicit specific antibodies has shown that the titers attained are approximately proportional to the amount of infective virus demonstrable in the suspensions. The findings as a whole indicate that far less virus exists in infective or antigenic form in the papillomas of domestic rabbits than in those of cottontail rabbits. PMID- 19871390 TI - AMINO ACID MIXTURES EFFECTIVE PARENTERALLY FOR LONG CONTINUED PLASMA PROTEIN PRODUCTION. CASEIN DIGESTS COMPARED. AB - When blood plasma proteins are depleted by bleeding with return of red cells suspended in saline (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and to certain intoxications. The ten growth essential amino acids of Rose plus glycine will maintain nitrogen balance and produce as much new plasma protein as will good diet proteins. This good utilization is demonstrated over periods of several months when the amino acids are given either orally or parenterally. There is no evidence of toxicity in general nor to unnatural forms of these synthetic amino acids in particular. Given parenterally appropriate mixtures of these amino acids are well tolerated even upon rapid injection. The minimal daily requirements for a 10 kilo dog may be given intravenously in 10 minutes without reaction. Subcutaneously a 10 per cent solution may be given rapidly without reaction. Among various mixtures tested Vt approximates a minimum for a 10 kilo dog. It contains in grams (dl threonine 0.7, dl-valine 1.5, l-(-) leucine 1.5, dl-isoleucine 1.4, dl-lysine hydrochloride 1.5, l(-) tryptophane 0.4, dl-phenylalanine 1.0, dl-methionine 0.6, l(+)-histidine hydrochloride 0.5, l(+)-arginine hydrochloride 0.5, and glycine 1.0. The presence of glycine improves tolerance to rapid intravenous injection, but excess glycine does not improve utilization of the mixture. Over a long period this mixture appears suboptimal in quantity. Doubled it is more than ample. Of two casein digests tested the one prepared by enzymatic hydrolysis provided good nitrogen retention and fairly good plasma protein production but was much less tolerable upon intravenous injection than certain mixtures of pure amino acids. The other one prepared by acid hydrolysis and tryptophane fortification afforded bare nitrogen equilibrium and produced virtually no plasma protein. Skin lesions observed after 10 to 20 weeks of synthetic diet probably reflect a deficiency of some member or members of the vitamin B(2) group. A persistent slight weight loss in the face of a strongly positive nitrogen balance may accompany this deficiency. PMID- 19871391 TI - METHIONINE PROTECTS AGAINST MAPHARSEN LIVER INJURY IN PROTEIN-DEPLETED DOGS. AB - Depletion of body protein stores by means of low protein diet or plasmapheresis causes greater susceptibility to liver injury by the arsenical compound, mapharsen. Normal dogs can tolerate mapharsen in doses of 0.006 to 0.008 gm. per kilo whereas in protein-depleted dogs doses of 0.002 to 0.0025 gm. per kilo cause liver injury with jaundice. Methionine (2 to 4 gm.) given by mouth 20 to 24 hours prior to administration of mapharsen is protective and the dogs will tolerate 0.0045 gm. per kilo with no icterus developing. Methionine (1 gm.) intravenously just prior to mapharsen injection is not as consistent in effecting protection, but the smaller dose may be responsible. PMID- 19871392 TI - QUALITATIVE DIFFERENCES IN THE ANTIGENIC COMPOSITION OF INFLUENZA A VIRUS STRAINS. AB - A study of the PR8, Christie, Talmey, W.S., and swine strains of influenza A virus by means of antibody absorption tests revealed the following findings: 1. Serum antibody could be specifically absorbed with allantoic fluid containing influenza virus or, more effectively, with concentrated suspensions of virus obtained from allantoic fluid by high-speed centrifugation or by the red cell adsorption and elution technique. Normal allantoic fluid, or the centrifugalized sediment therefrom, failed to absorb antibodies. Influenza B virus (Lee) caused no detectable absorption of antibody from antisera directed against influenza A virus strains, but it specifically absorbed antibody from Lee antisera. 2. The neutralizing, agglutination-inhibiting, and complement-fixing anti-bodies in ferret antisera were completely absorbed only by the homologous virus strain, even though 2 absorptions were carried out with large amounts of heterologous virus strains. 3. PR8 virus appeared to have the broadest range of specific antigenic components for it completely absorbed the heterologous antibodies in Christie and W.S. antisera and left only those antibodies which reacted with the respective homologous strains. The other virus strains (Christie, Talmey, W.S., swine) were more specific in the absorption of heterologous antibodies and completely removed only those antibodies which reacted with the absorbing virus. 4. The absorption tests revealed a higher degree of specificity and individuality of the virus strains than the various cross reactions previously reported. The strain specificity of PR8 virus was equally manifest in absorption tests with ferret sera and with human sera following vaccination. 5. The amount of homologous antibody remaining in a PR8 ferret serum after absorption with PR8 virus, obtained by the red cell adsorption and elution method, varied inversely as the concentration of virus used for absorption. A given concentration of virus, however, absorbed a greater percentage of neutralizing antibodies than either agglutination-inhibiting or complement-fixing antibodies. PMID- 19871393 TI - STUDIES ON THE ETIOLOGY OF PRIMARY ATYPICAL PNEUMONIA : A FILTERABLE AGENT TRANSMISSIBLE TO COTTON RATS, HAMSTERS, AND CHICK EMBRYOS. AB - 1. A filterable virus from certain cases of primary atypical pneumonia was transmitted to chick embryos by inoculation into the amnion of suspensions of bacteriologically sterile lung tissue or filtered sputum, and three strains were adapted by passage. 2. After intranasal inoculation into cotton rats or hamsters, suspensions of the infected chick embryo tissues produced pulmonary lesions which were similar to those seen after instillation of infective human material. 3. The agent propagated in chick embryos was specifically neutralizable by serum from patients recovered from primary atypical pneumonia and was not neutralized by the acute-phase specimens. 4. Passages of the virus in cotton rats and hamsters gave confusing results because of contamination with latent respiratory agents already present in the animals. PMID- 19871394 TI - THE SIGNIFICANCE OF ANTIGENIC DIFFERENCES AMONG STRAINS OF THE "A GROUP" OF INFLUENZA VIRUSES. AB - "Acute" and "convalescent" samples of serum from 40 patients from a localized outbreak of influenza were tested for mouse-protective antibodies against 7 different strains of influenza virus, which included 2 laboratory strains representative of "group A" and of "group B," and 5 strains from the investigated outbreak. The latter 5 strains although not identical were related to each other and to the PR8 strain. The chief point shown by the data was the considerable degree of antigenic difference among the 6 "group A" strains, evidenced by the marked differences in the protective capacities of the serums when tested against the various strains. A number of the "acute" serums showed high protective capacity against some strains but relatively little protective capacity against other strains. In the 5 instances in which it was possible to test the "acute" serums against strictly homologous strains of virus, no protective capacity was demonstrable. In 7 of 36 cases, the antibody responses evoked by influenza infections were not detectable by tests with some strains, but were detectable by tests against other related strains. PMID- 19871395 TI - THE CONSTITUTION OF MITOCHONDRIA AND MICROSOMES, AND THE DISTRIBUTION OF NUCLEIC ACID IN THE CYTOPLASM OF A LEUKEMIC CELL. AB - 1. Rat tumor extracts, containing chiefly the cytoplasmic constituents of leukemic cells, were fractionated into three main portions, the different components separating in the centrifuge according to size. 2. Mitochondria were isolated by centrifugation at relatively low speed. Elementary composition of purified mitochondria was found to correspond to about 11.5 per cent nitrogen, 1.6 per cent phosphorus, and 27 per cent lipids. Phosphorus and nitrogen content of the lipid portion suggests that as much as 75 to 80 per cent of the lipids of mitochondria is represented by phospholipids. Tests for ribose nucleic acid were positive. 3. Microsomes were separated by means of centrifugation at 18,000 x g. A relation between the high phosphorus content of the microsomes and the marked basophilia of the cytoplasm of leukemic cells is suggested. 4. Phosphorus distribution in the tumor extract, and light absorption analysis of the third fraction, seem to demonstrate that nucleic acid was not present either in a free condition, or in the form of nucleoprotein of relatively low molecular weight. The nature of the results suggests that ribose nucleic acid occurs in the cytoplasm of leukemic cells only in association with formed elements of relatively large size, namely microsomes, and mitochondria. PMID- 19871396 TI - BILIARY EXCRETION OF RADIOACTIVE IRON AND TOTAL IRON AS INFLUENCED BY RED CELL DESTRUCTION. AB - Iron is eliminated in the bile of normal dogs at a low but quite constant rate, 0.2 mg. per day. The feeding of large amounts of iron to normal dogs does not cause an increased iron excretion in the bile nor does the injection of considerable quantities of colloidal iron by vein. When red cell destruction is brought about by acetyl-phenylhydrazine the elimination of biliary iron may increase tenfold and parallels the increased output of bile pigment. When red cells containing radioactive iron are destroyed by acetyl-phenylhydrazine there is a significant increase in radioactive iron excreted in the bile which parallels the bile pigment excretion-Charts A and C. The excretion of iron and bile pigment is independent of the volume of bile. When hemoglobin is destroyed the pigment radicle is totally excreted as bile pigment but only 3 per cent of the released iron is eliminated in the bile with conservation of the remainder. The importance of the liver and spleen as storehouses of iron is again confirmed. The body conserves iron even when it is present in marked excess. PMID- 19871397 TI - POLIOMYELITIS IN THE CYNOMOLGUS MONKEY : III. INFECTION BY INHALATION OF DROPLET NUCLEI AND THE NASOPHARYNGEAL PORTAL OF ENTRY, WITH A NOTE ON THIS MODE OF INFECTION IN RHESUS. AB - 1. Poliomyelitis virus suspensions were atomized so as to produce dry droplet nuclei which, suspended in air, were introduced into a special infecting chamber and inhaled by test animals, both rhesus and cynomolgus monkeys. 2. Without olfactory blockade, 5 of 7 rhesus and 6 of 7 cynomolgus monkeys developed poliomyelitis of the CNS with entry through the olfactory nerves. 3. With olfactory blockade, 2 of 35 rhesus and 4 of 10 cynomolgus monkeys developed this form of the disease by routes proved by serial sections of the olfactory bulbs not to have been olfactory. 4. The neural pathways of infection from the mucous surfaces to the CNS in the 4 cynomolgus monkeys with blockade were shown in 2 instances to have been the afferent fibers of the trigeminal nerve into the Gasserian ganglion and thence to its central connections in the pons-medulla; in another case this was the probable route. In one instance the pathway consisted of the sympathetic fibers of the nose or nasopharynx into the cervical sympathetic ganglia and thence into the uppermost levels of the thoracic cord. The routes in the 2 rhesus monkeys with non-olfactory takes were not accurately determined but in one there was suggestive evidence of entry through the trigeminal nerve. 5. Study of the peripheral ganglia in a number of exposed cynomolgus and rhesus monkeys, including several with no demonstrated involvement of the CNS, revealed lesions most constantly in the Gasserian ganglia; less so in the cervical sympathetics and still less so in the celiac. In 2 rhesus monkeys dying of other causes a few days after exposure, lesions were limited to the Gasserian ganglia. No evidence was found in any case of passage of infection from the celiac ganglia into the CNS. 6. The importance of the peripheral ganglia as intermediate stations in the centripetal passage of infection from the body surface is again emphasized. 7. Comparison of the present with a previous study suggests that infection by inhalation of virus occurs with greater ease than by ingestion. PMID- 19871398 TI - EXPERIMENTAL STREPTOBACILLUS MONILIFORMIS ARTHRITIS IN THE CHICK EMBRYO. AB - 1. A strain of Streptobacillus moniliformis isolated from a case of rat bite fever in man has been found to produce infection of the developing chick embryo following inoculation of the chorio-allantois. 2. The disease in embryos is characterized by invasion of the blood stream and an almost exclusive localization of the infectious process to the synovial lining of the joints. 3. In the early stages of the development of the joint lesions the Streptobacillus moniliformis behaves as a facultative intracellular parasite within the cytoplasm of the synovial lining cells. Conditions favorable for the growth of the microorganisms are maintained only temporarily. The infection appears to be self limiting in nature. PMID- 19871399 TI - CERTAIN CONDITIONS DETERMINING ENHANCED INFECTION WITH THE RABBIT PAPILLOMA VIRUS. AB - The infection of normal or hyperplastic rabbit skin with the papilloma virus can be greatly enhanced by protecting the scarified and inoculated area with a layer of paraffined gauze until healing occurs. In this way the necrosis which follows upon scarification and also the scabbing are almost entirely prevented and in consequence epithelial regeneration is usually complete within 24 hours. Not only are many susceptible cells provided to the virus far earlier than would otherwise be the case,-and collateral tests have shown that it becomes associated with them within a few hours instead of after many,-but the inoculum is itself conserved, instead of becoming largely lost amidst necrotic tissue and scab, as under ordinary circumstances. The effective titer of the virus is increased by the procedure from 10 to 100 times over that attained when hyperplastic skin is allowed to dry after inoculation. Since the results under the latter circumstances are 10 to 100 times better than those when normal skin is treated in the same way it follows that a 100- to 10,000-fold increase in the effectiveness of the virus has now been obtained. PMID- 19871400 TI - THE HISTOPATHOLOGY OF PROGRESSIVE MUSCULAR DYSTROPHY AS REVEALED BY ULTRAVIOLET PHOTOMICROGRAPHY. AB - Results have been presented of the application of a simplified technique of ultraviolet photomicrography to a study of the specific lesions in muscle in subjects with progressive muscular dystrophy. An exact description of the histological changes occurring in this syndrome, as revealed by photomicrographs in ultraviolet light, is difficult at this time because of the lack of an adequate system of nomenclature. Attention has been drawn, however, to lesions of consistent character, found in sections of muscle removed at biopsy, which appear to be specific for the disease. The method of simplified ultraviolet photomicrography possesses certain marked advantages over those classical methods of histology and pathology which depend on staining and examination of specimens in visible light. Not only is greater resolution achieved with ultraviolet light photomicrography but the image which is obtained in the ultraviolet may provide some idea of the chemical nature of the tissue as well, since it results chiefly from the selective absorption of light by proteins, nucleoproteins, and nucleic acids. PMID- 19871401 TI - THE INITIATING AND PROMOTING ELEMENTS IN TUMOR PRODUCTION : AN ANALYSIS OF THE EFFECTS OF TAR, BENZPYRENE, AND METHYLCHOLANTHRENE ON RABBIT SKIN. AB - Benzpyrene brings about neoplastic changes in rabbit epidermis much sooner than has been supposed. The long interval that elapses before visible growths appear is due in the main to the relatively slight power of the carcinogen to encourage multiplication of the cells it renders neoplastic. Yet some slight power of this sort it has. Methylcholanthrene has somewhat more but not nearly so much as tar. It may initiate neoplastic changes within less than 17 days, as compared with less than 10 days for tar, but tumors due to it do not ordinarily appear until months after those called forth by tarring. All three agents give rise to growths of essentially the same kinds, but most of those due to benzpyrene and methlycholanthrene remain for a long while small, dry, and indolent whereas many of the tar tumors are fleshy, vigorous, and rapidly enlarging,-differences wholly consequent on differences in the ability to promote growth. Such ability is an important element in the effectiveness of carcinogens. Tar and the polycyclic hydrocarbons cause many more cells to become tumor cells than give rise to visible growths. Benzpyrene is as effective in initiating neoplastic changes when dissolved in mineral oil as when in benzene, yet no tumors result from it until months after the benzene solution has given rise to them, the reason being that when in oil it is almost devoid of influence to encourage cell proliferation. Benzene itself has a very slight influence of the sort. Solvents may determine not only whether carcinogens initiate neoplastic change but may condition to a crucial degree the influence of these agents to encourage tumor formation. Rabbit epidermis is much more responsive to carcinogenic influences than that of the mouse, as measured in terms of time taken to elicit benign neoplasms. Even benzene will call forth these growths from rabbit skin. In appraising the relative responsiveness to carcinogens of various animal species it is essential to reckon in terms of cells of identical type. PMID- 19871402 TI - THE DETERMINING INFLUENCE OF TAR, BENZPYRENE, AND METHYLCHOLANTHRENE ON THE CHARACTER OF THE BENIGN TUMORS INDUCED THEREWITH IN RABBIT SKIN. AB - The benign tumors of rabbit skin which appear in response to benzpyrene and methylcholanthrene are nearly all of the same kinds that tar produces, namely frill horns, papillomas, and carcinomatoids; but the collateral effects of these agents render many of them very different from the tar tumors. The connective tissue of the corium is so slowly excited by the pure hydrocarbons that for a long while it furnishes to most of the growths only a scanty stroma, when any, and in consequence they remain small,-low, dry, indolent, bas-relief affairs, made up almost entirely of the neoplastic epithelium,-not florid, fleshy excrescences with a large connective tissue component, such as tarring calls forth. The frill horns usually desquamate instead of building up like those due to tar, and some of their cells undergo a dyskeratotic change with result in spherical, homogeneous, deep-staining bullet-like elements, which give to the growths a singular aspect. In a frill horn due to benzpyrene numerous inclusion bodies were come upon which would seem to have been the result of intercurrent infection with a "passenger virus." Benzpyrene and methylcholanthrene produce papillomas, carcinomatoids, and frill horns in very different proportionate numbers from those obtaining when tar is the carcinogen. Tar gives rise much more frequently to carcinomatoids, -papillomas urged on to mimic cancers,-as would follow from its pronounced stimulating influence; yet it seldom produces frill horns whereas the pure hydrocarbons do so frequently. All three agents cause many more cells to become potentially capable of forming tumors than do so ordinarily, but the latent neoplastic elements on which tar exerts a promoting influence, causing them to form visible growths, are in general not the same as those which respond to benzpyrene and methylcholanthrene. Yet the relatively rare occurrence of frill horns due to tar cannot be wholly explained in this way and it becomes necessary to suppose that tar seldom changes normal cells into frill horn cells. Benzpyrene and methylcholanthrene give rise now and again to sebaceous adenomas, as tar does not. But tar does away with the sebaceous glands at an early period whereas the other two carcinogens cause them to increase notably in number. No evidence has been obtained that tar, benzpyrene, methylcholanthrene, arsenical preparations, or benzene,-which produces tumors of rabbit skin occasionally (1), bring about any neoplastic changes peculiar to them individually when they act upon cells of a single sort, those of the stratum germinativum of rabbit epidermis. Yet the experimental findings make plain that these agents exert no inconsiderable influence on the morphology of the benign cutaneous growths they call forth and on the frequency with which this or that kind occurs. In appraising the action of carcinogens one must take into account not only the capacity of these agents to induce neoplastic change and to promote, or perhaps suppress, tumor growth but an ability to condition to no inconsiderable extent both the kind of tumor arising and its structure. PMID- 19871403 TI - GELATIN-ITS USEFULNESS AND TOXICITY : BLOOD PROTEIN PRODUCTION IMPAIRED BY CONTINUED GELATIN BY VEIN. AB - Gelatin given by vein to doubly depleted dogs (anemic and hypoproteinemic) gives no immediate toxic response, no anaphylactoid reactions, and may contribute something to the building of new hemoglobin and plasma protein. Gelatin given by vein during 1 to 2 weeks (total 3 to 17 gm. per kilo) usually causes serious disturbances-inhibition of blood protein production, signs of intoxication, much weight loss, and even death. Gelatin given by vein for 2 to 3 days (total 1 to 3 gm. per kilo) may not cause any recognizable abnormalities, but dogs vary greatly in their response to gelatin by vein. Some dogs may tolerate a total of 7 gm. per kilo without significant disturbance and other dogs may be seriously intoxicated by 2 to 3 gm. per kilo. No one can predict which animal will be least tolerant. Some experiments with gelatin by vein for 2 to 3 days (total gelatin 1 to 2 gm. per kilo) given with and followed by amino acids or casein digests do show absence of intoxication and ample production of new hemoglobin and plasma protein during the weeks following the injection of gelatin. This may suggest possible usefulness of gelatin with amino acids or casein digests in acute emergencies (shock, hemorrhage). These doubly depleted dogs are very susceptible to various injurious agents as compared to normal dogs. They may serve as sensitive testing machines for evaluating plasma substitutes. Where the gelatin by vein inflicts its damage is not clear and there is little if any significant histological evidence but the disturbance of blood protein production implicates the liver. Gelatin of smaller molecular weight (degraded by autoclaving) is no less toxic than the standard gelatin. Gelatin by mouth may contribute to but cannot alone support the production of new hemoglobin and plasma protein. Gelatin by vein has definite limitations in dogs and, by implication, when used in human cases the amount given should be very carefully watched. PMID- 19871404 TI - PERITONEAL ABSORPTION : RED CELLS LABELED BY RADIO-IRON HEMOGLOBIN MOVE PROMPTLY FROM PERITONEAL CAVITY INTO THE CIRCULATION. AB - The absorption of red cells from the normal peritoneum of the dog can be demonstrated by means of red cells labeled with radio-iron incorporated in the hemoglobin of these red cells. Absorption in normal dogs runs from 20 to 100 per cent of the amount given within 24 hours. Dogs rendered anemic by bleeding absorb red cells a little less rapidly-ranging from 5 to 80 per cent of the injected red cells. Doubly depleted dogs (anemic and hypoproteinemic) absorb even less in the three experiments recorded. This peritoneal absorption varies widely in different dogs and even in the same dog at different times. We do not know the factors responsible for these variations but there is no question about active peritoneal absorption. The intact red cells pass readily from the peritoneal cavity into lymph spaces in diaphragm and other areas of the peritoneum. The red cells move along the lymphatics and through the lymph glands with little or no phagocytosis and eventually into the large veins through the thoracic ducts. PMID- 19871405 TI - A SEDIMENTABLE COMPONENT OF ALLANTOIC FLUID AND ITS RELATIONSHIP TO INFLUENZA VIRUSES. AB - Macromolecular material was isolated from normal allantoic fluid by a centrifugation procedure comparable to that currently employed for the concentration and purification of influenza viruses. The yield of material was found to vary with the age of the embryo, reaching a maximum average value after 14 days of incubation at 39 degrees C. of about 0.02 mg. per ml. of allantoic fluid. The purified material was found to contain protein, carbohydrate, and lipid and to have a general composition similar to purified preparations of PR8 influenza virus. A typical preparation of normal material had an isoelectric point at pH 2.3. Sedimentation studies indicated that the normal material can give a variety of sedimentation constants depending upon the concentration and viscosity of the preparations. The sedimentation constant, corrected for viscosity, of the major component of a fresh preparation was 170 S. The diameters of the predominant particles shown in electron micrographs of the normal material and of preparations of PR8 influenza virus were about 40 and 100 mmicro, respectively. Serological tests indicated that the normal material is a good antigen and that preparations of both A and B types of influenza virus obtained from allantoic fluids by centrifugation show a strong serological relationship to the normal material. Freezing and thawing of allantoic fluid, and repeated adsorption of virus on red cells, failed to provide a practical basis for the separation of normal protein from the virus entity in the case of PR8 virus. In the cases of similar preparations of F12 and of Lee viruses, a partial separation of a small component was accomplished by fractional centrifugation and this component and the normal protein were shown to be identical or very closely related. Antiserum to the purified normal material inhibited red cell agglutination by A and B types of influenza virus at serum dilutions of 600 to 700, but failed to show significant neutralizing capacity in chick embryo and in mouse tests at a serum dilution of 100. Rabbit antiserum to purified preparations of PR8 virus gave a 50 per cent red cell agglutination inhibition endpoint at a serum dilution of 112,000. Some of the implications of the findings are discussed. PMID- 19871406 TI - THE EXPERIMENTAL TRANSMISSION OF COLORADO TICK FEVER. AB - 1. The symptoms, history of tick bite, characteristic fever curve, and white blood cell picture should enable the physician to make a diagnosis of Colorado tick fever in nearly every case. 2. The typical white blood cell picture is a depression of the total leucocytes with a shift to the left of the granulocytes. Basophilic cytoplasmic bodies appear occasionally in lymphocytes 3 to 4 days after clinical recovery. 3. The disease can be transmitted serially in human beings by parenteral injection of blood or serum. Such transfers have not resulted in decreased or increased virulence. 4. The naturally acquired and experimental cases of Colorado tick fever are identical in their manifestations. 5. An attack of Colorado tick fever confers a degree of definite immunity to the disease. 6. Colorado tick fever is not a mild form of Rocky Mountain spotted fever since individuals immunized with ground tick vaccine against Rocky Mountain spotted fever are still susceptible to Colorado tick fever. 7. Adult Dermacentor andersoni ticks allowed to feed on typical cases, then carried through to a new generation and fed on susceptible adults, failed to transmit the disease. 8. Colorado tick fever has been successfully transmitted to an experimental animal, the golden hamster. PMID- 19871407 TI - HEMATOLOGICAL FINDINGS IN THE GOLDEN HAMSTER (CRICETUS AURATUS). AB - Values for hemoglobin, erythrocytes, volume of packed cells, leucocytes, and their distribution, and red blood cell diameter are presented as determined on a group of 114 hamsters of both sexes and of various ages. PMID- 19871408 TI - INDUCED RESISTANCE OF THE CENTRAL NERVOUS SYSTEM TO EXPERIMENTAL INFECTION WITH EQUINE ENCEPHALOMYELITIS VIRUS : III. ABORTIVE INFECTION WITH WESTERN VIRUS AND SUBSEQUENT INTERFERENCE WITH THE ACTION OF HETEROLOGOUS VIRUSES. AB - Although vaccination of guinea pigs with formalin-inactivated Western equine encephalomyelitis virus rendered them specifically immune to an intracerebral challenge dose of 1,000 M.L.D. of Western virus, it failed to protect their central nervous system against the initial effects of the virus: the intracerebral challenge dose was followed by an abortive infection of 20 to 30 hours' duration characterized by fever and histopathological changes which simulated the response at that early stage of non-vaccinated control animals. During the abortive infection of immune animals, virus could occasionally be demonstrated in their brains; indeed, it was detected with about the same frequency it was isolated from brains of similarly inoculated, non-immune guinea pigs during corresponding early phases of the infection. About one week after the abortive infection there was found a marked transitory accumulation of specific neutralizing antibody in the brain tissue. See PDF for Equation equalled at this time 1:1 to 1:10 instead of the value of about 1:300 found under physiological conditions. Guinea pigs which had recovered from an abortive infection with Western virus were resistant for a limited period of time to the effects of intracerebral inoculations of the immunologically distinct viruses of Eastern equine encephalomyelitis or vesicular stomatitis. PMID- 19871409 TI - RELATIONSHIP OF A NEW GROWTH FACTOR REQUIRED BY CERTAIN HEMOLYTIC STREPTOCOCCI TO GROWTH PHENOMENA IN OTHER BACTERIA. AB - By a series of quantitative assays of concentrates prepared in a variety of ways, it has been shown that the previously described growth factor now called "strepogenin," required by certain hemolytic streptococci, is very similar to and possibly identical with the recently described growth factors for Lactobacillus casei and Smith's Streptococcus lactis. An improved procedure for assay of strepogenin with the aid of Lactobacillus casei has been described, and additional properties of the growth factor have been presented. PMID- 19871410 TI - THE INFLUENCE OF DIET ON THE PRODUCTION OF TUMORS OF THE LIVER BY BUTTER YELLOW. AB - The presence of fat in the diet accelerates the production of hepatic tumors by p dimethylaminoazobenzene (butter yellow), and when its quantity is very small, few are produced. Butter yellow with diets consisting in large part of rice, or with other diets with low protein content, causes nodular cirrhosis, but, rice substituted for sugar in a diet containing protein, fat, and butter yellow with adequate vitamins accelerates the production of tumors though the added rice is insufficient to induce nodular cirrhosis. Rice favors the production of hepatic tumors by agencies that are not yet explained. Butter yellow produces hepatic tumors in the absence of cirrhosis, but with diets that produce cirrhosis, the frequency of tumors and of their precursors, cystic ducts and cholangiofibrosis, increases with the severity of cirrhosis. PMID- 19871411 TI - THE PATHOGENESIS OF TUMORS OF THE LIVER PRODUCED BY BUTTER YELLOW. AB - A conspicuous feature of the cirrhosis that is produced by butter yellow is the new formation of bile ducts that sprout from ducts of the larger portal spaces and penetrate between "portal units" to anastomose with liver cell columns at the periphery of these units. Hyperplasia of the liver may occur with butter yellow administration in the absence of cirrhosis or other change associated with widespread destruction of liver tissue; it occurs as diffuse or focal lesions and affects both parenchymal cells and newly formed ducts. Focal hyperplasia is a precursor of trabecular and adenomatous hepatomas which arise as multiple tumors. Butter yellow causes localized cystic dilatation of newly formed bile ducts unaccompanied by acute or chronic inflammation and liver cells adjacent to them may undergo hyperplasia. Cystic ducts by proliferation of their epithelium may form cyst-adenomas. Butter yellow causes newly formed ducts to undergo dilatation, and with acute inflammation and fibrosis to produce circumscribed macroscopically recognizable lesions (cholangiofibrosis). Cholangiofibrosis is the precursor of tumors that reproduce the histological characters of small bile ducts (cholangiomas), and often proceed to the formation of scirrhous carcinoma. Hepatomas, cyst-adenomas, and cholangiomas may become malignant with formation of metastases in which the characteristics of the parent tumor are reproduced. PMID- 19871412 TI - SPECIFICITY IN THE EFFECTS ON BRAIN METABOLISM OF TWO DIFFERING NEUROTROPIC VIRUSES. AB - 1. Brain tissue infected with the virus of Western equine encephalomyelitis shows specific differences in metabolism from brain tissue infected with the virus of poliomyelitis. 2. With added glucose concentration of 121 mg. per cent, oxygen utilization of poliomyelitic brain is significantly below normal and that of encephalitic brain is not. 3. With added glucose concentration of 217 mg. per cent, oxygen utilization of encephalitic brain is significantly below normal and that of poliomyelitic brain is not. 4. With lactate-glucose as the substrate, oxygen utilization of encephalitic brain is significantly below normal and that of poliomyelitic brain is not. 5. With pyruvate-glucose as the substrate, neither encephalitic brain nor poliomyelitic brain differs significantly from normal in oxygen consumption. 6. With succinate-glucose as the substrate, oxygen utilization of poliomyelitic brain is significantly above that of the normal control in the 1st hour. 7. With added glucose concentration of 37.5 mg. per cent, anaerobic metabolism of encephalitic brain is significantly below the normal whereas that of poliomyelitic brain is not. 8. With added glucose concentration of 229.5 mg. per cent, anaerobic metabolism of both encephalitic brain and poliomyelitic brain is significantly below the normal. PMID- 19871413 TI - THE COMPARATIVE EFFECTS OF VITAMIN B(1) DEFICIENCY AND RESTRICTION OF FOOD INTAKE ON THE RESPONSE OF MICE TO THE LANSING STRAIN OF POLIOMYELITIS VIRUS, AS DETERMINED BY THE PAIRED FEEDING TECHNIQUE. AB - In a paired feeding experiment the effects of vitamin B(1) deficiency and of restriction of food intake have been compared. In both groups of animals the number of cases of paralysis and the number of deaths were less than in a control group on an unrestricted amount of the complete diet. The maximum difference occurred on the 15th day after inoculation. The incidence of paralysis and death in the vitamin-deficient group was also less than in the paired restricted group. The maximum difference occurred on the 17th day following inoculation, after which the difference gradually became less. At the end of the experiment (28 days) there was a slightly greater number of deaths in the restricted group than in the vitamin-deficient group. Apparently the effect of vitamin B(1) deficiency on the action of the virus of poliomyelitis in the mouse is not due solely to the resulting anorexia. From the 3rd to the 25th day after inoculation the animals were examined at hourly intervals throughout the day and night. On the 26th and 27th days they were examined every 3 hours. Except for two mice in the unrestricted group dying before the hourly examinations were begun, peripheral paralysis was observed in every animal which died. PMID- 19871414 TI - STUDIES IN HUMAN IMMUNIZATION AGAINST INFLUENZA : DURATION OF IMMUNITY INDUCED BY INACTIVE VIRUS. AB - The administration to human beings of formalin-killed influenza virus, concentrated from allantoic fluid, resulted in a high order of antibody response within 2 weeks after injection. Even after 1 year the great majority of individuals vaccinated had antibody levels considerably above their prevaccination titer for the PR8, Lee, and a current 1943 strain. An investigation of the occurrence of epidemic influenza A in seven widely separated populations, 1 year after vaccination of part of these groups, showed that the attack rate among vaccinated persons was consistently lower than that of control individuals. The average reduction in attack rate was of the order of 35 per cent. PMID- 19871415 TI - THE RELATION OF CHEMICAL STRUCTURE IN CATECHOL COMPOUNDS AND DERIVATIVES TO POISON IVY HYPERSENSITIVENESS IN MAN AS SHOWN BY THE PATCH TEST. AB - 1. Additional evidence is presented in support of the view which postulates a close chemical and biologic relation between the active ingredients in poison ivy and Japan lac. 2. Biologic evidence, based on the use of the patch test in man, is presented in support of the view that the active ingredient in poison ivy is a catechol derivative with a long, unsaturated side-chain in the 3-position. 3. Of the catechol compounds and derivatives studied, group reactions in patients sensitive to poison ivy leaves or extract were exhibited by the following compounds: 3-pentadecyl catechol (100 per cent of 21 cases), 4-pentadecyl catechol (38 per cent of 21 cases), "urushiol" dimethyl ether (33 per cent of 33 cases), 3-pentadecenyl-1'-veratrole (21 per cent of 14 cases), 3-methyl catechol (14 per cent of 21 cases), and hydrourushiol dimethyl ether (10 per cent of 20 cases). It has been found that 3-geranyl catechol shows a practically constant group reactivity in persons sensitive to poison ivy. 4. The uniformly positive group reaction to 3-pentadecyl catechol is notable since this substance possesses a saturated side-chain, whereas the active ingredient in poison ivy is known to have an unsaturated side-chain. 5. The group reactivity was not restricted to the 3-position, for in some instances 4-pentadecyl catechol also gave group reactions which, however, were less intense and less frequent than those shown by 3 pentadecyl catechol. This indicates that in some cases a long side-chain in the 4 position may be effective in producing group specific reactions. 6. Only an occasional person showed sensitiveness to 3-methyl catechol (short side-chain), and in one instance the group reactivity appeared to be specific for the 3 position. 7. The position of the side-chain in the catechol configuration has some bearing on the degree and incidence of group reactions in persons hypersensitive to poison ivy. 8. Evidence is presented to indicate that the introduction of double bonds in the alkyl side-chain increases the incidence and intensity of group reactions. 9. Methylating the hydroxyl groups in the catechol configuration diminishes strongly the incidence of group reactivity but does not eliminate it entirely in persons hypersensitive to poison ivy. Thus, "urushiol" dimethyl ether (3-pentadecadienyl veratrole) gave group reactions in 33 per cent of 33 persons. 10. Methylating the hydroxyl groups as well as saturating the double bonds in the alkyl side-chain still further diminishes the group reactions but an occasional person hypersensitive to poison ivy may still show positive reaction to such a substance as 3-pentadecyl veratrole (hydrourushiol dimethyl ether). In this respect our results are not in full agreement with those recorded by Toyama who stated that hydrourushiol dimethyl ether is entirely harmless. 11. The significance of the group reactivity displayed by certain veratrole compounds is discussed, and several possible explanations of their behavior are advanced. 12. The group reactions discussed in this paper relate only to various catechol and veratrole compounds. Preliminary studies by us indicate that this sensitiveness extends to other phenolic derivatives. 13. Among the veratrole compounds showing positive reactions, the order of frequency and intensity was: (1) "urushiol" dimethyl ether (average of two double bonds); (2) S-pentadecenyl 1'-veratrole (one double bond); (3) hydrourushiol dimethyl ether (saturated side chain). It may be noted that 4-pentadecyl veratrole was inactive. PMID- 19871416 TI - THE ESSENTIAL DIFFERENCE BETWEEN THE TWO OPTIMUM PROPORTIONS FLOCCULATION RATIOS. AB - The fact that the optimum proportion flocculation ratio is different when determined by the alpha (Dean and Webb) and beta (Ramon) procedures is pointed out. It is demonstrated that this difference is a consequence of the difference in the two methods, and that the two optima, though they may in certain cases lie near together, can never coincide. A new ratio (the epsilon ratio), intermediate between the alpha and beta ratios, and having theoretical advantages over both of them, is defined. PMID- 19871417 TI - PREPARATION OF THE TYPE-SPECIFIC POLYSACCHARIDE OF THE TYPE I MENINGOCOCCUS AND A STUDY OF ITS EFFECTIVENESS AS AN ANTIGEN IN HUMAN BEINGS. AB - 1. Methods for preparing small amounts of Type I meningococcal polysaccharide which are electrophoretically homogeneous and contain only traces of other immunologically reactive material are given. 2. These polysaccharides are very poor antigens in man but in a small number of instances definite amounts of precipitin and protective antibody were formed. 3. The significance of these findings is discussed. PMID- 19871418 TI - PARALLELISM IN THE LETHAL AND HEMOLYTIC ACTIVITY OF THE TOXIN OF CLOSTRIDIUM SEPTICUM. AB - The relation of the lethal toxin to the hemolysin produced by Clostridium septicum, strain 44, has been investigated. The following results suggest that the hemolytic and lethal actions of crude toxin are functions of a single substance or that they are functions of two substances which have similar physical, chemical, and antigenic properties. (1) Within the limits of experimental error, the lethal activity of cultures is directly proportional to their hemolytic activity. (2) Treatment of a culture supernate with hydrogen peroxide diminishes to the same extent its hemolytic and lethal activities. (3) The hemolytic principle and the lethal toxin are adsorbed to approximately the same extent by charcoal. (4) The hemolytic principle and the lethal toxin are adsorbed to approximately the same extent by kaolin. (5) Treatment of culture supernate with erythrocytes results in the removal of most of the lethal activity as well as of most of the hemolytic activity. (6) Both lethal toxin and hemolytic principle are partially destroyed in dilute solution at 36 degrees C. The loss in lethal and hemolytic activities occurs in parallel. (7) The lethal and hemolytic activities of cultures are found to be inseparable by fractional precipitation with ammonium sulfate. (8) The antihemolytic capacity of antitoxic horse serum is found to be directly proportional to the antilethal capacity. PMID- 19871419 TI - NUTRITIONAL REQUIREMENTS AND FACTORS AFFECTING THE PRODUCTION OF TOXIN OF CLOSTRIDIUM SEPTICUM. AB - A medium consisting of a complete acid hydrolysate of casein supplemented with cystine, tryptophan, growth accessory factors, glucose, and inorganic salts, has been developed for the cultivation of Clostridium septicum. Toxin equivalent to 400 to 700 L.D(50) per ml. has been obtained regularly in this medium. The principal factors found to affect the yield of toxin are:- (a) Phase of strain employed: Cultures of Cl. septicum may contain a number of variants. Some of these may be characterized by their colonial morphology on blood agar as: (1) rough, non-hemolytic colonies; (2) smooth, non-hemolytic colonies; (3) smooth, hemolytic colonies. Of these three variants, only the last produces toxin. (b) Quantity of growth and length of time cultures were incubated: The toxin and hemolysin content of cultures increases as the bacterial population increases, reaching a maximum value when the number of bacteria is at a maximum, or shortly thereafter. Upon further incubation, the toxin and hemolysin content decreases. (c) Presence of a hemolysin-inactivating factor: A substance, possibly lipid, and present in cooked meat, is capable of inactivating hemolysin produced in casein hydrolysate medium and can account for the absence of hemolysin from cultures grown in cooked-meat broth. PMID- 19871420 TI - KINETICS OF LYSIS BY CLOSTRIDIUM SEPTICUM HEMOLYSIN. AB - The kinetics of the hemolytic reaction effected by the hemolysin of Clostridium septicum, strain 44, has been studied with regard to the effect of concentration, temperature, and hydrogen ion concentration on the rate of the hemolytic reaction. The kinetics of hemolysis was found to resemble in several respects that of enzyme-catalyzed reactions, but differed in the absence of a clearly defined pH optimum. Attention is drawn to differences between the hemolytic system studied and certain other hemolytic systems. PMID- 19871421 TI - EXPERIMENTAL TYPHUS INFECTION IN THE EASTERN COTTON RAT (SIGMODON HISPIDUS HISPIDUS). AB - 1. The course of typhus infection in cotton rats has been described, and a relationship between the dose administered and the time of death has been demonstrated. 2. Rather incomplete pathological studies indicated that typhus in the cotton rat is an acute infection primarily involving mesothelial tissue, and tissues of mesothelial origin. Depending somewhat upon the route of infection, rickettsiae were most easily demonstrated in smears from liver, brain, and pericardial and peritoneal exudates. By subinoculation into the yolk sacs of fertile eggs, rickettsiae were readily isolated from these sources and, with rather less facility, from blood. 3. Although relatively large numbers of rickettsiae were found necessary to produce lethal infections, the susceptibility of the cotton rat as measured by the development of an immunizing infection proved to be very high. The supporting data suggest that cotton rats might be suitable for the isolation of new strains. 4. Contrary to the earlier report (1), age was not found to influence markedly the susceptibility of the cotton rat to lethal infection with any of the strains studied. 5. Comparative studies indicated that cotton rats were just as susceptible to murine infection as white mice and more susceptible to Breinl infection than the latter animal. The susceptibility of cotton rats and of guinea pigs to Breinl infection was found to be about the same. Comparative studies in these animals were not made with other strains. 6. No toxic activity of rickettsial suspensions could be demonstrated for cotton rats, although suspensions of infected cotton rat livers were shown to be toxic for mice. 7. A method has been described by which three strains of Rickettsia prowazeki were carried in serial intracardial passage as fatal infections for cotton rats. No evidence was obtained that prolongation of such passage increased the virulence of the strains for the rats. 8. Cotton rats surviving typhus infection were shown to be solidly immune to reinfection with homologous virus and to possess nearly complete immunity to rickettsiae of heterologous immunologic character. Sera from recovered rats, furthermore, were shown to possess neutralizing, complement-fixing, and antitoxic antibodies but no agglutinins for proteus OX19. 9. The technique of a serum neutralization test in cotton rats has been described in which the test antigen consists of suspensions of infected cotton rat livers. By this technique neutralizing antibody was demonstrated in human, rabbit, guinea pig, and cotton rat sera. Although some degree of cross-neutralization could be shown, serum titers against homologous antigen were uniformly greater than against comparable doses of antigen of heterologous immune nature. PMID- 19871422 TI - FURTHER OBSERVATIONS ON THE RELATION OF THE EYE TO IMMUNITY IN EXPERIMENTAL SYPHILIS : II. THE DEVELOPMENT OF IMMUNITY AFTER PRIMARY INTRACORNEAL INOCULATION. AB - Two experiments are reported in which an attempt was made to determine the extent to which a primary syphilitic infection of the cornea in rabbits is followed by the development of a local corneal immunity, by the generalization of the virus, and by the development of a general immunity to the infection. Female rabbits were inoculated intracorneally with a virulent strain of T. pallidum and the disease was allowed to run its course until the lesions which had developed at the site of inoculation had healed spontaneously. Popliteal lymph nodes were transferred from about one-half of these animals (in the second experiment only) to normal male rabbits and in almost every instance the nodes were proved by this method to contain virulent treponemes, showing that generalization of the syphilitic infection is the rule after intracorneal inoculation. All animals were treated with arsphenamine after the local lesion had subsided (160 and 275 days after the original inoculation). The rabbits were then reinoculated with the homologous strain of treponemes, injections being made into the cornea originally inoculated and also into the skin of the back. In one experiment both corneas were reinoculated. The incidence of lesions developing in either cornea after reinoculation was higher than the incidence of lesions developing in the skin. The lesions developing in the corneas of the "immune" animals had a longer incubation period and were of shorter duration on the average than the lesions in the control group. As far as intensity of reaction was concerned no difference was observed. Inoculation of the cornea of rabbits with syphilitic virus is often followed by the development of immunity to the homologous strain of organisms. This immunity is imparted to the skin to a greater extent than to either the cornea inoculated originally or to the opposite uninoculated cornea. It persists after treatment with arsphenamine. It appears to be more marked the longer treatment is postponed. It is apparent from Table IV that in one-half of all the test animals both cornea and skin were immune to a second inoculation of homologous syphilitic virus. In addition to these there were 5 animals in which the cornea was immune and the skin nearly so, for the lesions which developed in the skin of these animals were minimal in extent and duration and were in no way comparable to those which were observed in the controls. Thus in two-thirds of our animals there developed in both the skin and the cornea, after a primary intracorneal inoculation, a high degree of resistance toward a second inoculation with homologous syphilitic virus, but syphilitic disease of the cornea does not always impart to the cornea itself an absolute immunity to reinoculated homologous virus. PMID- 19871423 TI - FURTHER OBSERVATIONS ON THE RELATION OF THE EYE TO IMMUNITY IN EXPERIMENTAL SYPHILIS : III. THE INFLUENCE OF A NON-SPECIFIC INFLAMMATORY REACTION IN THE CORNEA ON THE DEVELOPMENT OF IMMUNITY IN THAT TISSUE AFTER INTRATESTICULAR INOCULATION. AB - Two experiments are reported in which rabbits originally inoculated with syphilis and treated late in the course of the disease (174th to 210th day) were reinoculated subsequently in both corneas with the homologous strain of syphilitic virus. In each animal one cornea was inoculated with dead tubercle bacilli prior to reinoculation with the syphilitic virus. This procedure was carried out in order to bring about a non-specific inflammatory reaction with resultant vascularization, the intention being to find out if such vascularization would render the cornea more resistant to inoculation with the homologous strain of syphilitic virus. The results of both experiments were similar and while they were not conclusive, they indicated that there was a tendency for corneas which had been injected with dead tubercle bacilli to be more refractory to a subsequent inoculation with homologous syphilitic virus than the corneas of the same animals that had not been injected with dead tubercle bacilli. This tendency may be interpreted as suggestive evidence for the view that in the syphilitic rabbit there develop circulating antibodies toward the homologous strain of T. pallidum. PMID- 19871424 TI - A DEVICE FOR AUTOMATICALLY CONTROLLING THE CONCENTRATION OF GLYCOL VAPORS IN THE AIR. AB - A device for automatically maintaining any desired concentration of triethylene or propylene glycol vapor in air is described. It can also be used to measure very rapidly the glycol content of room air. This instrument should greatly facilitate tests of the efficacy of glycol vapors in preventing air-borne infections. PMID- 19871425 TI - POLIOMYELITIS BY ACCIDENTAL CONTAGION IN THE CHIMPANZEE. AB - Poliomyelitis virus was isolated from the stools of two uninoculated chimpanzees which had been quartered for 6 months in cages adjoining those of rhesus monkeys receiving intranasal inoculations of potent human stools. Upon arrival, and for 4 months thereafter, neither chimpanzee had antibody against the virus eventually isolated from it. However, antibody had developed against the animals' own virus strains at the time these were isolated from the feces. PMID- 19871426 TI - STUDIES ON A NON-HEMOLYTIC STREPTOCOCCUS ISOLATED FROM THE RESPIRATORY TRACT OF HUMAN BEINGS : I. BIOLOGICAL CHARACTERISTICS OF STREPTOCOCCUS MG. AB - A single serological type of non-hemolytic streptococcus, designated streptococcus MG, has been isolated from the lungs of fatal cases of primary atypical pneumonia, from the sputa of patients with this disease, and occasionally from the respiratory tracts of normal human beings. Certain biological characteristics of this microorganism have been studied. All of the 59 strains isolated have been shown to belong to a homogeneous bacteriological group with characteristics which serve to distinguish it from any other well defined species of streptococcus. It has been suggested that this microorganism probably represents a distinct and hitherto undifferentiated species of streptococcus. PMID- 19871427 TI - STUDIES ON A NON-HEMOLYTIC STREPTOCOCCUS ISOLATED FROM THE RESPIRATORY TRACT OF HUMAN BEINGS : II. IMMUNOLOGICAL CHARACTERISTICS OF STREPTOCOCCUS MG. AB - The results of studies on the antigenic structure and immunological specificity of a non-hemolytic streptococcus, designated streptococcus MG, are described. Evidence is presented to show that this microorganism possesses a capsule and that this structure contains a polysaccharide antigen which is responsible for the type specific serological reactions obtained with streptococcus MG. PMID- 19871428 TI - STUDIES ON A NON-HEMOLYTIC STREPTOCOCCUS ISOLATED FROM THE RESPIRATORY TRACT OF HUMAN BEINGS : III. IMMUNOLOGICAL RELATIONSHIP OF STREPTOCOCCUS MG TO STREPTOCOCCUS SALIVARIUS TYPE I. AB - The results of studies on the immunological relationship between streptococcus MG and Streptococcus salivarius type I are described. Evidence is presented to show that Streptococcus salivarius type I, like streptococcus MG, possesses a capsular polysaccharide antigen. Similarities in the capsular polysaccharides of these two different species of non-hemolytic streptococci appear to be responsible for their immunological relationship. PMID- 19871429 TI - STUDIES ON THE MAMMARY TUMORS OF DOGS : I. LACTATION AND THE INFLUENCE OF OVARIECTOMY AND SUPRARENALECTOMY THEREON. AB - Spontaneous mammary tumors occur in middle aged or senile dogs and are of three principal pathological types; a diffuse epithelial and connective tissue overgrowth often with associated cartilage and bone; solid masses of epithelial cells; intracystic papillomatous tumors. The metastases in this series were always composed of papillary carcinomatous cysts; this tissue in transplants to abdominal connective tissue induced epithelial osteogenesis. All of the dogs with mammary tumors had lipid-rich suprarenal cortical tumors. The tumors frequently secrete a dilute milk with citric acid content considerably increased above serum levels; large numbers of colostrum corpuscles are present in this fluid. After weaning, normal parturient dogs undergo a complete cessation of mammary secretion; lactation persists considerably longer in dogs with mammary tumor than in normal dogs. Absence of suckling does not eliminate lactation in pseudopregnancy. The failure of the breast to lactate under the stimulus of prolactin signifies a lack of physiological maturity. The breasts of mature dogs have two types of response to ovariectomy; either great physiological involution results or lactation, actual or potential, is retained in areas for at least 3 to 6 months. Those in which excision of the ovaries does not cause prompt and great involution of the breast include all dogs with mammary tumors, all with pseudopregnancy, and certain dogs, presumably normal which we are unable to characterize further at this time. Excision of the suprarenal glands in addition to the ovaries usually did not completely eliminate lactation or the lactational potential. PMID- 19871430 TI - PLASMA PROTEIN METABOLISM-NORMAL AND ASSOCIATED WITH SHOCK : OBSERVATIONS USING PROTEIN LABELED BY HEAVY NITROGEN IN LYSINE. AB - Labeled plasma proteins are produced by administering to dogs the amino acid lysine synthesized with heavy nitrogen. Such labeled proteins are apparently indistinguishable biologically from proteins of normal isotope concentration. Labeled plasma proteins, as plasma, injected into normal dogs pass out of the blood stream at an initially rapid but constantly decreasing non-logarithmic rate. This outflow is balanced by a simultaneous inflow of plasma proteins from the tissues. Fifty per cent of the labeled protein is out of the blood stream in about 24 hours; 75 per cent in about 6 days. Shock due to trauma of intestine or leg shows a dilution curve of labeled plasma protein not unlike that of the normal dog. If anything, dilution appears a little less rapid in shock. Since the usual shrinkage of plasma volume and plasma protein mass is present in these shocked dogs, these data are compatible with a decreased inflow of protein into the plasma during shock. Methods are described which are suitable for the use of heavy nitrogen incorporated in the epsilon group of lysine and its subsequent analysis in body fluids. These data may indicate that the plasma proteins are normally in constant and rapid exchange with a mobile pool of body protein. PMID- 19871431 TI - ADJUVANTS IN IMMUNIZATION WITH INFLUENZA VIRUS VACCINES. AB - Subcutaneous inoculation, of PR8 allantoic fluid, or watery suspensions of the virus obtained from allantoic fluid by high-speed centrifugation or by elution after adsorption on red cells induced serum antibodies in experimental animals, which reached the highest levels within 2 weeks after inoculation and were gradually lost thereafter. The addition of killed acid-fast bacteria (Myco. tuberculosis or butyricum), paraffin oil, and a proprietary adsorption base (Falba) to form a stable water-in-oil emulsion of influenza virus suspensions greatly enhanced and maintained immunity and antibody response to the virus. These adjuvants provided a much more effective method of increasing antibody production to the virus than the use of concentrated preparations of virus alone. Paraffin oil and Falba without the acid-fast bacilli were less effective as adjuvants, although the antibody levels induced were higher than those produced by watery suspensions of the virus and were maintained at a constant level for at least 6 months. Myco. butyricum appeared to be more effective in producing antibodies against the virus than the tubercle bacilli in the emulsions of paraffin oil and Falba. Immunization with these adjuvants and suspensions of influenza virus obtained from allantoic fluid induced antibodies not only against the virus but against antigenic material contained in normal allantoic fluid, although the latter titers were considerably lower. A suspension of influenza virus (sedimented by high-speed centrifugation) and Myco. butyricum in sesame oil induced about four times as much antibody as when the virus was suspended in saline, in sesame oil alone, or in combination with typhoid bacilli. PMID- 19871432 TI - THE SPIROCHETICIDAL ACTION OF PENICILLIN IN VITRO AND ITS TEMPERATURE COEFFICIENT. AB - 1. Penicillin was found to be actively spirocheticidal in vitro against the Reiter, Kazan, Nichols, and Noguchi strains of so called S. pallida, and a strain of mouth spirochetes. The threshold concentration was 0.01 unit per Cc. (1 160,000,000 penicillin). The rate and degree of action increased with the concentration of penicillin up to a level of approximately 0.1 to 0.25 unit per cc., which rendered more than 99 per cent of the organisms non-viable within 12 hours. Higher concentrations did not appreciably accelerate the effect. 2. Within the range 4 x 10(4)-10(7) organisms per cc., the initial rate at which the spirochetes were killed was not affected by their number. Consistent with that observation, no demonstrable penicillin was bound or inactivated by thick suspensions. The amount of penicillin required to sterilize suspensions of varying density nevertheless varied to a large extent with the initial number of organisms. This was only in part due to the progressive deterioration of the penicillin with prolonged incubation; and the persistence of organisms resistant to the drug, and perhaps an adaptative change after prolonged exposure to penicillin, may be contributing factors. 3. The organisms remained actively motile for a period of 8 to 24 hours after they had been rendered non-viable by the action of penicillin. Even 500 units of penicillin per cc., or approximately 10,000 times an effectively spirocheticidal concentration, did not accelerate that delayed immobilization. It follows that, although penicillin rapidly renders the organisms non-viable, the metabolic system affected is not immediately essential to the life of the cell, and the motility and presumably other vital functions remain unaffected for a significant number of hours. 4. The rate at which the organisms were killed by penicillin increased with temperature in the range 8-40 degrees C. With an original inoculum of 10(6) spirochetes per cc., the percentage of organisms surviving after 24 hours at 39-40 degrees , 36-37 degrees , 32-33 degrees , 22-23 degrees , and 8 degrees C. was 0.02, 0.2, 1, 10, and 100 respectively; and those results were independent of the concentration of penicillin in the range 0.25 to 250 units per cc. If these observations with a non-pathogenic organism in vitro are applicable to the pathogenic organism in vivo, they suggest that the combined use of fever and penicillin in the treatment of syphilis may be more effective than either alone. PMID- 19871433 TI - INFLUENCE OF pH AND OF CERTAIN OTHER CONDITIONS ON THE STABILITY OF THE INFECTIVITY AND RED CELL AGGLUTINATING ACTIVITY OF INFLUENZA VIRUS. AB - A study has been made of the pH stability of centrifugally purified strains of influenza virus with respect to the biological properties of mouse infectivity and chicken red blood cell agglutinating activity. Observations also were made on the importance of composition of buffer, temperature of storage, and concentration of virus protein to the stability of the virus. When tested for stability at a protein concentration of 0.1 mg. per cc. in phosphate buffer, the infectivity of PR8 virus was found to be most stable at pH 6.5-7; the swine virus, at pH 7-7.9; and the Lee strain, at a pH of 7.9 or higher. The CCA activity of the PR8 virus in phosphate buffer was most stable at pH 7, that of the swine virus at pH 7-8, and that of the Lee virus at a pH greater than 9. Furthermore, the Lee virus was much less stable in dilute solution in phosphate buffer, even under optimum conditions of pH, than either the PR8 or swine strains. The different strains of influenza virus were found to possess certain characteristics in common. They lost infectivity and CCA activity on the acid side of optimum pH conditions much more rapidly than on the alkaline side. Under suitable conditions of buffer and pH, the infectivity decreased while the CCA activity remained unchanged. In general, the rate of loss in infectivity was greater than the rate of loss in CCA activity. When tests of stability were carried out at a protein concentration of 0.1 mg. per cc. in a composite phosphate-glycine-NaCl buffer, the virus strains showed less marked differences and possessed much higher stabilities of CCA activity and infectivity than when stored at the same concentration in phosphate buffer alone. Under the modified conditions, all three viruses possessed maximum stabilities of CCA activity and infectivity at pH 7-8 with the exception of the PR8 virus whose infectivity appeared more stable at pH 7 than at pH 8. In detailed experiments with the Lee virus, it was found that the infectivity and CCA activity of this strain at pH 7 and at a protein concentration of 0.1 mg. per cc. were maintained best in the composite phosphate-glycine-NaCl buffer, less well in a buffer containing glycine and NaCl, and least well in phosphate buffer alone. In tests with PR8 virus, the activity was found to be much more stable at 4 degrees C. than at 23 degrees C. When stored at a concentration of 2 mg. per cc. at 4 degrees C. in phosphate buffer at pH 7, the PR8 and Lee strains were found to be much more stable than when stored at the concentration of 0.1 mg. per cc. At the higher concentration, no significant losses in either infectivity or CCA activity were observed over a period of 2 months. PMID- 19871434 TI - THE SEDIMENTATION RATE OF THE BIOLOGICAL ACTIVITIES OF INFLUENZA A VIRUS. AB - The sedimentation rates of the mouse infectivity principles of the PR8 and the F12 strains of influenza A virus were shown by studies in the separation cell to have values which are not significantly different from sedimentation rates of the principal components of purified preparations. It was shown further that the bulk of the chicken red blood cell agglutinating activity and of the chick embryo infectivity of PR8 influenza virus preparations sediments at the same rate as that of the 100 mmicro. component. Some activity was shown to be associated with aggregates. These results lend strong support to the assumption that the three biological activities are associated with the particles characterized as spheres with a diameter of about 100 mmicro. PMID- 19871435 TI - BIOPHYSICAL PROPERTIES OF PREPARATIONS OF PR8 INFLUENZA VIRUS. AB - The biophysical properties of several preparations of PR8 influenza virus have been studied. Electron micrographs showed slightly irregular, circular particles with an average diameter of 115 mmicro and a standard deviation of the distribution of diameters of 15 per cent. The specific volume was determined with a pycnometer to be 0.79. The sedimentation rate was found to vary inversely with the concentration of virus. The extrapolated value for one preparation was 722 Svedberg units and the value for another preparation was 658 units. Sedimentation studies in sucrose solutions of varying densities showed a non-linear dependence of sedimentation rate upon solvent density, indicating that the density in solution increases with increasing sugar concentration. The virus particles floated in a sugar solution with a density of 1.18. The density in the absence of sucrose was estimated to be about 1.1. The virus was shown not to lose infectivity very rapidly in sucrose solutions. The spreading of the boundary during sedimentation was shown to be represented by a standard deviation of the sedimentation rate equal to 8 per cent of the mean. This corresponds to a distribution of diameters with a standard deviation of 4 per cent of the mean. A more slowly sedimenting component was observed with the ultracentrifuge in the highest concentrations of several of the preparations. The intrinsic viscosities, calculated on the basis of concentrations expressed as grams per cubic centimeter, of several highly purified preparations were determined to be between 11.3 and 16.5. The variation of sedimentation rate with concentration was shown to be due entirely to the variation of solution viscosity with concentration. The viscosity of the virus preparations can be explained as being due in great part to the presence of the slower sedimenting contaminating components which possess a very high intrinsic viscosity. The average particle diameter of the anhydrous PR8 virus particle was calculated from sedimentation and specific volume data to be about 80 mmicro. The discrepancy between this value and that obtained from the electron micrographs, the greater size distribution from the electron micrographs, the slight irregularities in some of the particles as observed in the electron micrographs, the behavior of the sedimentation process in sucrose solutions of different densities, and the inactivation of the virus by withdrawal of electrolytes can all be explained in a straightforward manner if it is assumed that the virus particles in solution contain, in addition to the constituents shown by chemical analysis, about 60 per cent by weight of water. It is estimated that such hydrated virus particles are about 100 mmicro in diameter. PMID- 19871436 TI - ELECTROPHORETIC STUDIES ON PR8 INFLUENZA VIRUS. AB - Crude preparations of PR8 influenza virus, obtained by high-speed centrifugation, contain two electrophoretically distinct components. One of these, present to the extent of 10 to 20 per cent, was identified by electrophoresis, centrifuge, and activity tests, as an impurity similar to or identical with a high molecular weight acidic substance shown by Knight to be elaborated by normal uninfected embryos. The other component, present to the extent of 80 to 90 per cent, appeared to represent the active virus. The virus fraction was separated from the impurity by repeated fractional centrifugation. It then appeared homogeneous in the analytical centrifuge and in the Tiselius apparatus, and possessed an isoelectric point at pH 5.3 as measured by the micro-electrophoresis method. PMID- 19871437 TI - EFFECT OF ENZYME INHIBITORS AND ACTIVATORS ON THE MULTIPLICATION OF TYPHUS RICKETTSIAE : I. PENICILLIN, PARA-AMINOBENZOIC ACID, SODIUM FLUORIDE, AND VITAMINS OF THE B GROUP. AB - By injection into typhus-infected yolk sacs, a number of agents were tested for possible inhibition or acceleration of rickettsial growth. The previously reported rickettsiostatic activity of penicillin was further confirmed. Para aminobenzoic acid, in single injections of 6.6 mg. and 3.3 mg. giving initial concentrations of approximately 1:6000 and 1:12,000 was found to have rickettsiostatic activity approximately equal to that of penicillin. No conclusion could be drawn regarding the possibility of a synergistic action of para-aminobenzoic acid and penicillin. Para-aminobenzoic acid neutralized with sodium hydroxide was found to be as effective as the acid itself, when given in single injections of 6.6 mg. Sodium benzoate, as Well as the ortho and meta forms of aminobenzoic acid were found to be ineffective when given in similar amounts. Para-aminobenzoic acid, when added to the food in a concentration of 3 per cent, was shown to have a remarkably effective chemotherapeutic action on murine typhus infection in mice. Sodium fluoride was found at times to accelerate the growth of rickettsiae in the yolk sac, and to cause heavy infection under conditions such that the controls showed practically no multiplication of the organism. When rickettsiostatic substances (penicillin and para-aminobenzoic acid) were combined with sodium fluoride, their rickettsiostatic activity was not demonstrably changed. Other agents studied and found not to affect rickettsial multiplication are listed. The possible mechanisms involved in the observed inhibition and stimulation of rickettsial growth under these conditions are discussed. PMID- 19871438 TI - CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : VII. A QUANTITATIVE STUDY OF THE TYPE SPECIFIC AND GROUP SPECIFIC ANTIBODIES IN ANTIMENINGOCOCCAL SERA OF VARIOUS SPECIES AND THEIR RELATION TO MOUSE PROTECTION. AB - 1. The quantitative method for the estimation of agglutinins has been applied to antimeningococcal horse, rabbit, and chicken sera and to the sera of humans convalescing from meningococcus meningitis. The type-specific and group-specific agglutinin N can be measured, using homologous and heterologous suspensions of meningococci. 2. Type I horse, rabbit, and chicken antimeningococcal sera contain considerable amounts of antibody which cannot be removed either by Type II meningococcus suspension or by preparations of the Type I specific polysaccharide. This residual type-specific antibody has marked potency in protecting mice against subsequent infection with meningococci. 3. Most human convalescent sera contain group-specific antibody. Small amounts of protective antibody and of antipolysaccharide are also formed. 4. Type I antisera absorbed with Type I polysaccharide and with Type II meningococci could be used as a guide in the purification of this new antigen. PMID- 19871439 TI - IMMUNITY IN MUMPS : II. THE DEVELOPMENT OF COMPLEMENT-FIXING ANTIBODY AND DERMAL HYPERSENSITIVITY IN HUMAN BEINGS FOLLOWING MUMPS. AB - 1. A specific antibody, demonstrable by the technique of complement fixation, regularly appears, or increases in concentration, in the sera of human beings during an attack of mumps or during convalescence. 2. Specific dermal hypersensitivity, demonstrable by the injection of heat-inactivated mumps virus, has been shown to develop in 6 human beings after recovery from mumps. 3. Complement-fixing antibody and the hypersensitive state also emerge as a result of clinically inapparent infection with the virus of mumps. 4. These two phenomena are apparently unrelated in respect to immunologic mechanisms. 5. The data presented indicate that the complement fixation test should prove of value both in diagnosis and in the determination of immunity. 6. The skin test for dermal hypersensitivity, on the other hand, becomes positive after recovery and therefore would appear to be useful only as an index of resistance. PMID- 19871440 TI - IMMUNITY IN MUMPS : III. THE COMPLEMENT FIXATION TEST AS AN AID IN THE DIAGNOSIS OF MUMPS MENINGOENCEPHALITIS. AB - 1. Fifty-one patients exhibiting signs and symptoms compatible with the clinical syndrome of acute aseptic meningoencephalitis have been studied by means of the complement fixation test for the demonstration of antibody reacting with the virus of mumps or its products. 2. In 17 of these individuals in whom the clinical diagnosis could be made with assurance because of an associated enlargement of the salivary glands, the test yielded evidence of recent infection with the virus. 3. In 16 patients without involvement of the salivary glands the results of the test likewise indicated recent infection with this virus. 4. In the remaining 18 patients the test gave no evidence of a recent infection with the virus. 5. Except for histories of recent exposure obtained from certain of the individuals in whom the complement fixation test was considered to be positive, the characteristics of the disease and the data afforded by the usual laboratory studies failed to distinguish the last 2 groups. 6. On the basis of these findings, it is concluded that the complement fixation test should be of value in the diagnosis of those cases of acute aseptic meningoencephalitis in which the virus of mumps is the etiologic agent and in which involvement of the salivary glands is slight or absent. PMID- 19871441 TI - AN ETIOLOGIC CONSIDERATION OF DONOVANIA GRANULOMATIS CULTIVATED FROM GRANULOMA INGUINALE (THREE CASES) IN EMBRYONIC YOLK. AB - 1. A microorganism identical with that originally described by Anderson has been cultivated in pure strain from two additional cases of granuloma inguinale by means of inoculating the yolk of chick embryos with uncontaminated human tissue containing Donovan bodies. 2. The morphological and cultural characteristics of the three isolated strains are described and discussed. 3. This microorganism has been cultivated in vitro only in media containing embryonic yolk. It failed to grow on any of a variety of artificial media. 4. It has not proved to be pathogenic for common experimental animals. 5. The Donovan body is reproduced in the epithelial cells of the yolk sac and in the yolk. The microorganism evidently reproduces both extracellularly and intracellularly. 6. The microorganism produces in culture antigens that elicit immune reactions in the skin and serum of granuloma inguinale patients. 7. This microorganism is judged to be a bacterium and the etiological agent of granuloma inguinale. 8. It is proposed that these strains of the bacterium be the type of a new genus, Donovania, in recognition of Donovan's original description of the pathognomonic bodies of granuloma inguinale; and that the specific name granulomatis be applied to designate its relationship to the characteristic lesion of the disease. PMID- 19871442 TI - IMMUNOLOGIC RELATIONSHIP OF DONOVANIA GRANULOMATIS TO GRANULOMA INGUINALE. AB - 1. A washed bacterial suspension of Donovan microorganisms cultivated in the yolk of chick embryos was used as an antigen in intracutaneous tests in 6 cases of granuloma inguinale in the active stage of the disease. These injections were responded to by an extensive erythematous and edematous reaction that reached its height in 24 hours and disappeared within 48 hours later. Four control cases without granuloma inguinale did not react to the injection to any greater extent than would be expected from the slight trauma incident to them. The skin of the reacting patients responded in a similar manner but to a lesser extent to a filtrate of infected yolk. Simultaneous control injections of filtered normal yolk demonstrated that sensitivity to normal yolk was not responsible for the reactions. 2. A mucoid material present in infected yolk, soluble in N/100 NaOH, and precipitable by N/100 HCl was recovered and purified by repeated acid precipitation, extraction with ether, washing in distilled water, and dissolution in N/100 NaOH. We regard this material to be of capsular origin. 3. The presumptive capsular material injected intradermally elicited a somewhat different and milder reaction in patients with active granuloma inguinale, but we regard it as specific. 4. The "capsularrdquo; material in suitable dilution elicited distinct precipitation reactions when mixed with the serum from 18 of 19 cases of active granuloma inguinale. Serum from 1 active case showed no precipitation. Sixty-four serums, including 6 from lymphopathia venereum patients and 18 from Wassermann- or Kahn-positive patients, and 1 from an early chancroid failed to precipitate. Two serums from a total of 66 used as controls showed a precipitate in the presence of the capsular material. These patients gave no history or evidence of granuloma inguinale. 5. The "capsular" material fixed complement in the presence of serum from patients with granuloma inguinale. Serum from 12 of 15 cases of granuloma inguinale demonstrated complement fixation. Three failed to fix complement. Of 19 control serums 18 failed to fix complement in the presence of the capsular material and 1 fixed only a very slight amount of complement. None of these serums nor the capsular material itself was anticomplementary. 6. The high proportion of precipitation and complement fixation reactions obtained from patients with active granuloma inguinale is indicative of a specific immunological relationship of the Donovan microorganism cultivated in embryonic yolk to the disease, granuloma inguinale. 7. We suggest that one or all of these methods might be so standardized as to be of distinct diagnostic value. PMID- 19871443 TI - AN ELECTRON MICROSCOPE STUDY OF ISOLATED MITOCHONDRIA : METHOD AND PRELIMINARY RESULTS. AB - 1. The present paper constitutes a preliminary study of the morphology of mitochondria by means of electron microscopy. 2. The mitochondria that were the subject of this investigation were obtained from a lymphosarcoma of the rat. They were separated from the other components of the leukemic cells by a method of differential centrifugation, and thus made available for direct examination in the electron microscope. 3. In the purified form the mitochondria appeared as spherical bodies, the majority of them varying in size approximately from 0.6 to 1.3 micro in diameter. 4. Certain aspects of mitochondria in the electron microscope suggest that these elements are surrounded by a differentiated membrane. In some cases the limiting membrane seemed to be responsible for maintaining the general shape of the mitochondria, even when most of the mitochondrial substance had been lost. 5. By means of the electron microscope, it is possible to distinguish small elements, 80 to 100 mmicro in diameter, within the body of certain mitochondria. Further work is suggested to establish whether these small granules are normal constituents of mitochondria, and what relation may exist between them and ordinary microsomes. 6. The nature of mitochondria as morphological units is discussed. Present evidence indicates that mitochondria constitute definite physical entities which can persist in the absence of the cytoplasm. PMID- 19871444 TI - HEREDITY OF THE Rh BLOOD TYPES : II. OBSERVATIONS ON THE RELATION OF FACTOR HR TO THE RH BLOOD TYPES. AB - 1. The theory of six allelic genes is reviewed, using the new improved nomenclature, and data are summarized regarding the distributions of the eight Rh types among white and negro individuals in New York City. 2. Results are presented of tests for property Hr in a series of 239 white individuals and 49 negroes. Statistical analysis of these data yields results supporting Race and Taylor's hypothesis that anti-Hr sera react with the blood properties determined by the genes Rh(2), Rh'' Rh(o), and rh, but not with the factors determined by genes Rh(1) and Rh'. 3. The practical importance of the Hr factor is discussed. PMID- 19871445 TI - THE ROLE OF THE LYMPHOCYTE IN ANTIBODY FORMATION. AB - Following the injection of typhoid antigen or sheep erythrocytes into the pad of the rabbit's hind foot, lymph from the efferent lymphatic of the popliteal lymph node was collected and analyzed for antibody content. On separating the lymphocytes from the lymph plasma, it was found that the antibody titer of the cell extract was substantially and consistently higher than that of the surrounding fluid. This difference was greatest at the time of greatest rate of increase of antibody titer in the whole lymph, rather than when the antibody titer of the lymph plasma was highest. These results can only be interpreted to mean that the lymphocytes either produce antibodies or take them up from the lymph plasma. Incubation in vitro of lymphocytes containing one species of antibody with lymph plasma containing another showed that antibodies pass from the cells to the supernatant lymph fluid to reach approximate equilibrium; acquisition of antibody from supernatant lymph fluid was not observed. Similar results were obtained when normal lymphocytes were allowed to incubate in vivo in their own lymph fluid to which antibodies had been added. It was again found that antibodies were not absorbed or adsorbed by lymphocytes. These results seem to indicate that lymphocytes are instrumental in the formation of antibodies. PMID- 19871446 TI - STUDIES ON MENINGOCOCCAL INFECTION : XIII. CORRELATION BETWEEN ANTIPOLYSACCHARIDE AND THE ANTIBODY WHICH PROTECTS MICE AGAINST INFECTION WITH TYPE I MENINGOCOCCI. AB - Absorption tests indicated that the protective antibody (Type I) in four antimeningococcal horse sera corresponded closely to one of the components of the polysaccharide preparation previously isolated by the authors from Type I meningococci. This antibody was, however, a minor fraction in the three therapeutic sera tested, being secondary in amount to non-protective antibody corresponding to another component of the polysaccharide preparation, plus antibody corresponding to agar. In one case, removal of the agar-antibody diminished the protective titer by 30 per cent. PMID- 19871447 TI - OBSERVATIONS ON THE SITES OF REMOVAL OF BACTERIA FROM THE BLOOD IN PATIENTS WITH BACTERIAL ENDOCARDITIS. AB - In 6 patients with bacterial endocarditis studies were made of the bacterial content of arterial and venous blood. Paired samples were collected, approximately simultaneously, from two different locations in the circulatory system, and colony counts were determined. As many as 48 specimens were taken for culture during a single period of study. Venous blood was drawn not only from different locations in the extremities, but also from the superior and inferior venae cavae, the right auricle, and the hepatic and renal veins. As would be expected, colony counts were highest in arterial blood. Blood from the antecubital veins gave colony counts only slightly lower than arterial blood. In the femoral veins, on the other hand, there were appreciably fewer organisms. This difference is attributed to the type of tissues drained by the two veins. Colony counts in blood from the superior and inferior venae cavae were also lower than arterial counts, the ratio being comparable to that found in femoral vein blood. In the renal veins colony counts were only slightly below the arterial level indicating that few organisms are removed from the blood during passage through the kidneys. The greatest reduction in bacterial content was found in hepatic vein blood. In 3 of the 6 subjects this reduction amounted to more than 95 per cent, and in all subjects the difference was very considerable. Mixed venous blood in the right auricle of the heart gave colony counts which were usually one-half to two-thirds as high as in corresponding samples of arterial blood. An interesting finding in these studies was a remarkable constancy of the bacterial content of arterial blood, during periods of 1 or 2 hours. Despite the fact that a considerable portion of the bacteria which leave the heart in arterial blood appear to be removed during a single circuit of the body, the number of bacteria in successive samples of arterial blood shows little change. This indicates that in bacterial endocarditis organisms are discharged into the blood from the endocardial vegetations at a comparatively even rate, rather than in a haphazard fashion as a result of the breaking off of infected particles. PMID- 19871448 TI - IMMUNITY IN MUMPS : I. EXPERIMENTS WITH MONKEYS (MACACUS MULATTA). THE DEVELOPMENT OF COMPLEMENT-FIXING ANTIBODY FOLLOWING INFECTION AND EXPERIMENTS ON IMMUNIZATION BY MEANS OF INACTIVATED VIRUS AND CONVALESCENT HUMAN SERUM. AB - Since the experimental data have already been discussed at some length, it is here necessary only to review those observations which appear to be of most significance. The manifestations of the disease we have produced in monkeys have in general been similar to those described by previous workers. It has been found that members of the species M. mulatta are regularly susceptible to infection with the virus of mumps, provided they have not been in contact with animals which have recently been infected. Such contact may be followed by the development of resistance to inoculation unattended by overt signs of infection. Following the intraparotid injection of virus into a susceptible animal, an antigen appears in the gland which reacts specifically in the complement fixation test with sera of monkeys which have recovered from an attack of mumps. This antigen has not been demonstrated in any other organ of the infected monkey which has been examined, nor does it persist or increase in amount when introduced into the brain or the testes. Attempts to propagate it in the tissues of other animal species including the developing hen's egg and tissue cultures have so far been uniformly unsuccessful. The antigen is relatively thermostabile, resisting a temperature of 65 degrees C. for at least 20 minutes at the optimal hydrogen ion concentration. It is unimpaired by a concentration of formalin of 0.3 per cent. Together with the virus it may be preserved indefinitely in the frozen state. The maximal quantity of antigen in the gland, which may be considerable, is attained on or about the 5th day following inoculation of the virus. An antibody which reacts with the antigen appears in the serum from 8 to 14 days after infection. This antibody has not been found in the serum of normal monkeys which have had no opportunity for contact with the virus. It has been demonstrated during convalescence in the serum of all animals which have been examined. The antibody which is present in large amounts soon after recovery, although decreasing in concentration with the lapse of time, may continue to be present for many months. At 62 degrees C. for 20 minutes its activity is not reduced and on storage at 4 degrees C. its titer has remained unaltered for over 2 years. A similar factor which appears in human beings convalescent from mumps is less stabile, since its activity is reduced appreciably under these conditions. In the CO(2) cabinet, however, both antibodies can be preserved for long periods of time. The definition of these reagents has afforded means whereby the simian infection with the virus of mumps, whether it is actively in progress or has occurred at some time in the past, can be recognized. Upon the establishment of these facts, the estimation of the quantity of antigen in the glands of vaccinated animals was employed as an index of their resistance in studies on the effect of the injection of formolized and alumprecipitated formolized suspensions of infected parotid gland. It has been shown that such vaccines, in which the virus has been rendered inactive, lead to the production of complement-fixing antibody. In about 60 per cent of the vaccinated animals, moreover, evidence of increased resistance was obtained as indicated by the partial or complete suppression of the formation of antigen in the inoculated gland. In certain instances no evidence of resistance was observed, yet antibody was found to be present. It is clear, therefore, that resistance is not determined solely by the presence of the complement-fixing antibody. The possibility, however, of its participation as a factor in immunity cannot be excluded. Employing the same criterion of resistance, the virus-neutralizing capacity of a pool of human mumps convalescent sera and of a globulin concentrate prepared from the pool has been studied. Neither of these materials was found to prevent entirely the formation of antigen, although each of them appeared to exert some inhibitory effect. PMID- 19871449 TI - ANAEROBIC GLYCOLYSIS OF THE BRAIN IN EXPERIMENTAL POLIOMYELITIS. AB - The rate of anaerobic glycolysis of brain tissue was compared for normal animals and animals with experimentally induced poliomyelitis, using two different strains of mice and two different procedures. The report of interference of poliomyelitis with anaerobic glycolysis of brain was not confirmed. In one series there was a small increase and in the other series a small decrease in the brain Q(CO(CO2) ) (N(2) ) calculated for infected animals as compared to normal animals. When the calculations were made on the basis of wet weight of brain there was no difference in glycolysis. It is considered that the methods so far used for study of the enzymes may be inadequate, and that no decision is as yet possible on the effect of poliomyelitis on anaerobic glycolysis. PMID- 19871450 TI - THE VIRUS-NEUTRALIZING ACTION OF SERUM FROM MICE INFECTED WITH POLIOMYELITIS VIRUS. AB - Evidence is presented that the serum of mice paralyzed with the Lansing strain of poliomyelitis virus possesses the capacity to protect normal mice against the same virus when mixtures of virus and serum are inoculated intracerebrally. The virus-neutralizing action was present mainly in mice paralyzed between the 3rd and 6th days following inoculation and was rarely demonstrable in the serum of mice developing paralysis more than 10 days after inoculation. Serum from non paralyzed mice had approximately the same neutralizing capacity when obtained during the same period following inoculation in which serum from paralyzed mice showed the greatest effect. Neutralization of the virus was not obtained with serum from normal mice or from mice inoculated with normal nervous tissue. Further investigation of the phenomenon is in progress. PMID- 19871451 TI - ECK FISTULA LIVER SUBNORMAL IN PRODUCING HEMOGLOBIN AND PLASMA PROTEINS ON DIETS RICH IN LIVER AND IRON. AB - The Eck fistula shunts the portal blood around the liver which receives its blood only by way of the hepatic artery. There are slight gross and histological changes in the Eck fistula liver of the dog. There is evidence at times of some functional abnormalities of the liver due to the Eck fistula but the dog can tolerate this fistula for 1 to 8 years and appear normal. Chloroform is tolerated by the Eck fistula dog, which may take twice a lethal dose for the control dog without evidence of significant liver injury. Acacia given by vein is deposited in the Eck fistula liver and impairs further its functional capacity to contribute to hemoglobin production. The stress of anemia brings out the fact that the anemic Eck fistula animal cannot utilize standard diet factors and iron as efficiently as the anemic non-Eck control dog. The output of new hemoglobin in some instances may drop to one-fourth of normal. When hypoproteinemia alone or combined with anemia is produced in the Eck fistula dog, we observe at times very low production of plasma protein-seven a drop to one-tenth of normal. This interrelation of liver abnormality, liver dysfunction, and lessened plasma protein and hemoglobin production is significant. It is generally accepted that the liver is concerned with the production of several plasma proteins-fibrinogen, prothrombin, and albumin. The experiments above indicate that the liver is concerned directly or indirectly with the production of new hemoglobin. Our belief is that the liver contributes to the fabrication of hemoglobin by means of the mobile plasma proteins which to a large extent derive from the liver. PMID- 19871452 TI - THE PREPARATION AND PROPERTIES OF INFLUENZA VIRUS VACCINES CONCENTRATED AND PURIFIED BY DIFFERENTIAL CENTRIFUGATION. AB - Influenza virus vaccines containing from 1 to 10 mg. of virus materials per cc. concentrated and purified from infectious allantoic fluids by means of one or two cycles of differential centrifugation and inactivated by different treatments have been prepared and subjected to laboratory tests. Suitable inactivation of the virus preparations with retention of full red cell agglutinating activity and immunizing potency in mice was achieved by treatment with minimal amounts of formaldehyde or ultraviolet light. Treatment with phenol or chloroform failed to cause adequate loss of virus activity. Excessive amounts of formaldehyde or of ultraviolet light were found to cause a loss in red cell agglutinating activity and in immunizing potency. Freezing resulted in the immediate loss of red cell agglutinating activity of the formalinized vaccine. Storage of the vaccines in the frozen state was accompanied by a gradual decrease in red cell agglutinating activity. Drying of the vaccines from the frozen state resulted in a loss of red cell agglutinating activity and, in the case of the formalinized vaccine, in a loss in immunizing potency. There appeared to be at least a rough correlation between red cell agglutinating activity and immunizing potency. The immunizing potency and red cell agglutinating activity of a purified formalinized vaccine containing 2 mg. of virus material per cc. were unchanged following 2 months' storage at 4 degrees but were measurably decreased following storage for 2 months at 18 to 25 degrees and at 37 degrees . At equivalent dosages of virus material the immunizing potency of formalinized centrifugally purified virus, of formalinized virus purified by the red cell elution method, and of infectious allantoic fluid was not measurably different. The immunizing potency of a formalinized polyvalent vaccine containing centrifugally purified Lee, PR8, and Weiss influenza virus materials at concentrations of 5, 2.5, and 2.5 mg. per cc., respectively, was found to be essentially the same as that of a similar vaccine prepared commercially. In both cases the protection afforded against the Weiss strain appeared to be better than that against the Lee and PR8 strains. The commercially prepared vaccine is being subjected to clinical tests in man at dosage levels ranging from 0.01 mg. to 10 mg. The latter corresponds to a level approximately 100 times that of infectious allantoic fluid. It was found that the bacterial contamination that frequently accompanies operation on a large scale can be controlled by the addition of one part per 10,000 of formalin plus one part per 100,000 of phenyl mercuric nitrate to the allantoic fluid immediately following harvesting, without affecting the quality of the vaccine. This procedure and the use of virus materials purified and concentrated by a single cycle of differential centrifugation by means of the Sharples centrifuge were found to be suitable for the production of influenza virus vaccines on a large scale. By means of this method influenza vaccines possessing 20 or more times the immunizing potency of infectious allantoic fluid and 10 or more times the immunizing potency of the usual commercial vaccine prepared by the red cell elution method can be manufactured rapidly on a very large scale with considerable ease and efficiency. PMID- 19871453 TI - BLOOD VESSELS IN FAT TISSUE. RELATION TO PROBLEMS OF GAS EXCHANGE. AB - 1. The ratio of the surface of the capillary bed to the volume of tissue supplied by the vessels (S/V ratio) for both open and closed capillaries in fat-rich tissue of the rat is 51.9, in fat-poor tissue of the same sort 222.2. About one half of the capillaries in fat-rich tissue, to one-fourth in fat-poor tissue, are open during ordinary activity. The total capillary bed of fat-rich tissue is one third as great as in muscle; the total capillary bed of fat-poor tissue has about the same density as that of the most poorly supplied muscle. This establishes the fact quantitatively that the capillary bed of fat is relatively inadequate, compared to other tissues, for transferring inert gases from fat tissue at a sufficiently rapid rate to prevent the occurrence of extravascular bubbles following rapid decompression from high pressure atmospheres. It also explains the greater distention of the blood vessels in fat tissue, due to gas, than in any other tissue following decompression. The observations have a bearing also on the estimation of the permeability of the blood-fat barrier to inert gases. 2. The volume of protoplasm of fat cells may be very small; a method is presented for estimating it quantitatively. Since it alone is important in metabolism, recalculation of the basic data on a basis of the ratio of surface area of capillaries to volume of protoplasm of fat cell in fat tissue yields a more useful figure. For fat-rich fat tissue S/V (protoplasm) = 2159.0 (for total capillary surface) or 977.6 (for open capillary surface). This means that for purpose of metabolism, the capillary bed is far richer than that of muscle. PMID- 19871454 TI - A STUDY OF TISSUE CULTURE CELLS BY ELECTRON MICROSCOPY : METHODS AND PRELIMINARY OBSERVATIONS. AB - By means of a tissue culture technique, cells from chick embryos were procured in a state which proved to be suitable for electron microscopy. The electron micrographs disclosed details of cell structure not revealed by other methods of examination. PMID- 19871455 TI - PASSIVE IMMUNITY TO POLIOMYELITIS IN THE CHIMPANZEE. AB - A series of 6 chimpanzees was inoculated orally with stool from a poliomyelitis patient. Three of these animals had been given 170 cc. of homologous, hyperimmune monkey serum prior to inoculation, while three were unprotected. All 6 of the animals were subsequently shown to have poliomyelitis virus in their stools and characteristic lesions in their central nervous systems although none of them developed paralytic poliomyelitis. All of the immunized animals had demonstrable blood antibody at the time of inoculation although it was present in only one case 30 days later. PMID- 19871456 TI - NON-PARALYTIC POLIOMYELITIS IN THE CHIMPANZEE. AB - 1. Thirteen cases of non-paralytic poliomyelitis infection in chimpanzees are described. Nine of these animals were excreting virus in. their stools at periods of from 3 days to 8 weeks following inoculation. 2. All animals killed during the acute stage showed lesions in the brain distributed in centers usually involved in, and compatible with the presence of, poliomyelitic infection. In 2 chimpanzees typical cord lesions were also present. No lesions were found in the brains of 4 control chimpanzees which had had no virus contact as far as known. The occurrence of a purely systemic or peripheral form of poliomyelitis, without lesions in the central nervous system, has thus not been established. 3. Four instances of arrest of the pathological process near the portal of entry into the brain, indicating partial resistance, are included in this series. One was a chimpanzee inoculated intranasally (A1-75) who had severe tuberculosis at the time of inoculation. The second was an animal convalescent after intracerebral inoculation (A1-74), who sustained a second infection limited to the olfactory bulbs when inoculated intranasally 2 months later with homologous virus. The third (A5-01) was inoculated orally with human stool, but contammation of the olfactory area resulted with infection of the olfactory bulbs and of the forebrain; virus was present in the stools of this animal. The fourth chimpanzee (A48) had suffered an initial non-paralytic attack after stomach tube inoculation, followed by a second attack about 9 months later after oral inoculation with part of the same virus-containing pool (human stools). The second attack consisted of a facial paralysis, with arrest of the pathological process near the facial nucleus. 4. Although cerebral lesions were light in some of the non-paralytic and inapparent infections, their presence in all indicates the action of virus on the central nervous system with the possibihty of production of at least partial local resistance. It is not unreasonable to assume that this may occur in inapparent human cases, although the point is, of course, not susceptible to critical proof in man. 5. The degree of severity of pathological involvement in non-paralytic cases varies from a fully developed distribution of lesions in brain and spinal cord in some chimpanzees, to mild and scattered lesions in the brains of others. This suggests that if the extent of pathological reaction is an indicator of subsequent local resistance to reinfection, the degree of protection afforded by a non-paralytic attack of poliomyelitis to even homologous virus must be variable. PMID- 19871457 TI - STUDIES IN RODENT POLIOMYELITIS : VI. FURTHER OBSERVATIONS ON INTERFERENCE BETWEEN MURINE AND SIMIAN STRAINS OF POLIOMYELITIS VIRUS. AB - 1. Attempts to separate by processes of physical segregation, i.e. ultrafiltration, ultracentrifugation, or dialysis, from live SK murine poliomyelitis virus a non-pathogenic agent capable of interfering with simian poliomyelitis virus were unsuccessful. Neither was it possible to convert live SK murine virus into a non-pathogenic interfering agent by processes of chemical inactivation, i.e., phenolization or formalinization. 2. Preparations of SK murine virus, which had been markedly attenuated by ultraviolet irradiation, gave evidence of having retained some interfering power in rhesus monkeys. 3. MM murine poliomyelitis virus interfered, both in mixture tests and by peripheral administration, with two simian strains of poliomyelitis virus. With adequate amounts, distinct protective effects could be obtained in rhesus monkeys which had received murine virus (animal passage or tissue culture virus) up to 48 hours after intracerebral infection with simian poliomyelitis virus. 4. Theiler's virus of spontaneous mouse encephalomyelitis, when tested in mixture with simian poliomyelitis virus, gave some evidence of irregular and low grade interference. Interference could not be shown conclusively in experiments to prevent poliomyelitic infection or to modify its effects. 5. The nature of the interfering agent present in murine virus is discussed. PMID- 19871458 TI - THE CARDIOTOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : I. INCREASED SENSITIVITY OF THE ISOLATED FROG'S HEART TO REPEATED APPLICATION OF THE TOXIN. AB - 1. A study has been made of the effect on the isolated frog's heart of a preparation derived from the supernatant fluid of cultures of hemolytic streptococcus. 2. The streptococcal preparation was found to induce systolic contracture, the contracture usually developing only after the second of two administrations of the preparation. It was found that a single application of the streptococcal preparation sensitized the heart to a second application. 3. The properties of the cardiotoxic factor so far as they have been studied were found to be identical with those of the oxygen-labile hemolysin of streptococci. The capacity of normal and of immune sera to neutralize the cardiotoxic action paralleled the antihemolytic potency of the sera. PMID- 19871459 TI - THE CARDIOTOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : II. INHIBITION OF CARDIOTOXIC EFFECT BY A SUBSTANCE RELEASED FROM THE FROG'S HEART. AB - 1. The mechanism of sensitization of the isolated frog' heart to a product of the hemolytic streptococcus has been investigated. The sensitization depends upon the release from the isolated heart of a substance which inhibits the action of the cardiotoxin. The inhibitor is released upon the first (sensitizing) administration of cardiotoxin, but not upon the second (contracture-producing) administration. 2. The inhibitor released by the heart neutralizes the lethal factor present in the streptococcal preparation employed. 3. Some of the properties of the inhibitor have been investigated. PMID- 19871460 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : I. THE SPECIFIC ANTIGENS OF SHIGELLA PARADYSENTERIAE (FLEXNER). AB - 1. Methods for the isolation of the specific antigens of Types V, W, Z, and Newcastle Shigella paradysenteriae are given. 2. The physical, chemical, toxic, and immunological properties of these substances are described. PMID- 19871461 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : II. THE CHEMICAL DEGRADATION OF THE SPECIFIC ANTIGEN OF TYPE Z SHIGELLA PARADYSENTERIAE (FLEXNER). AB - The chemical and enzymatic dissociation of the specific antigen of Type Z Shigella paradysenteriae has been studied. The chemical, toxic, and serological properties of the products of degradation have been investigated. The nature of the toxic component has been discussed. PMID- 19871462 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : III. ANTIBODY RESPONSE IN MAN FOLLOWING THE ADMINISTRATION OF THE SPECIFIC ANTIGEN OF TYPE V SHIGELLA PARADYSENTERIAE (FLEXNER). AB - 1. Volunteers have been immunized with the purified specific antigen of Type V Shigella paradysenteriae (Flexner). The subjects developed a high titer of bacterial agglutinins and mouse-protective antibodies. The agglutinin titer fell moderately after a period of 6 months. The subjects responded fairly well to a small recall dose of the antigen. 2. Two individuals from a group of 10 injected with the specific polysaccharide obtained from Type V organisms responded with an increase in bacterial agglutinins. Mouse-protective antibodies were demonstrable in the one serum tested. PMID- 19871463 TI - NUTRITION OF THE HOST AND NATURAL RESISTANCE TO INFECTION : I. THE EFFECT OF DIET ON THE RESPONSE OF SEVERAL GENOTYPES OF MUS MUSCULUS TO SALMONELLA ENTERITIDIS INFECTION. AB - 1. A diet of whole wheat and whole dried milk has been shown to promote a higher survival rate, among W-Swiss mice subjected to S. enteritidis infection, than that promoted by a "synthetic" diet. 2. The demonstration of this ability of diet to condition natural resistance has been found to depend upon the genetic constitution of the mice employed. The demonstration has been possible in W-Swiss mice, a strain only moderately inbred and retaining a degree of genetic variability. The demonstration has not been possible in three highly inbred strains of mice selected so that they differed predictably from one another in natural resistance. 3. The nutritional factors involved are present in whole wheat and are absent or negligible in dried whole milk. Their nature has not yet been determined. PMID- 19871464 TI - A NEW VIRUS DISEASE OF PIGEONS : I. RECOVERY OF THE VIRUS. AB - A virus has been isolated from the tissues of a pigeon with visceral lesions that were characterized by focal necrosis of parenchymatous tissue, by the presence in affected cells of intranuclear inclusions of the herpetic type, and by secondary inflammatory reaction. This newly recognized virus, which has been tentatively called the I.N.I. agent is pathogenic for pigeons and embryonated eggs but is avirulent for rabbits, guinea pigs, and mice. The virus is smaller than the agent of psittacosis and is immunologically different from it. The I.N.I. agent and psittacosis virus were both of etiological importance in an epizootic among pigeons. Some birds were infected simultaneously with the two agents while others were infected with only one. PMID- 19871465 TI - CIRRHOSIS OF THE LIVER IN "DONOR" DOGS FED A HIGH FAT DIET AND SUBJECTED TO REPEATED BLEEDINGS. AB - 1. In 13 dogs used repeatedly as donors for plasmapheresis and plasma injection experiments and fed a kennel diet that for a period of over a year consisted chiefly of bones with much adherent fat, cirrhosis of the liver occurred in 10. Marked fatty change without definite fibrosis occurred in 2 of the dogs. 2. In control dogs fed the same kennel diet during the same period but not subjected to repeated bleedings, no instance of cirrhosis was observed. 3. In previous plasmapheresis and plasma injection experiments "donor dogs" subjected to similar bleedings over comparable periods but maintained on a different kennel diet did not develop cirrhosis. 4. This series of events suggests that in dogs maintained on a relatively high fat diet repeated bleedings predispose them to cirrhosis of the liver. No data are available to decide the more fundamental question: Do the repeated bleedings remove something (other than hemoglobin) necessary for continued integrity of the liver, or is the cirrhosis the result of relative anoxia or increased lipemia occasioned by the repeated bleedings or perhaps of both combined? PMID- 19871466 TI - HEMOGLOBIN AND PLASMA PROTEIN : THEIR RELATION TO INTERNAL BODY PROTEIN METABOLISM. AB - Hemoglobin (presumably its essential protein globin), given intraperitoneally to a protein-fasting dog, will be used effectively to supply the protein requirements of the body. Nitrogen balance may thus be maintained for 20 days under favorable conditions. New hemoglobin and plasma protein will be formed related to hemoglobin injections in depleted dogs where there is urgent need for these proteins (anemia and hypoproteinemia). Obviously this calls for supplementary amino acids which in globin are low and we assume these amino acids must be contributed from body protein stores. Plasma proteins (in plasma) tested in the same manner are completely utilized with no loss of nitrogen, positive nitrogen balance, weight balance, and no change in the albumin-globulin ratios. Hemoglobin (globin) is less effectively utilized as compared with plasma protein given parenterally and there is some increase in urinary nitrogen above control periods. The albumin-globulin ratio may be somewhat modified by hemoglobin injections intraperitoneally. Hemoglobin (globin) digests contribute effectively to body maintenance of nitrogen equilibrium. These digests are about as effective as whole hemoglobin in maintaining nitrogen balance but cause a rise in undetermined nitrogen not seen when hemoglobin alone is given intraperitoneally. Pigment radicles derived from hemoglobin given intraperitoneally are thrown away and appear as surplus bile pigment even when there is urgent need for all available nitrogenous material-given protein fasting, anemia, and hypoproteinemia in a bile fistula dog. The body evidently prefers to make rather than conserve the pyrrol aggregate (pigment radicle). We assume that the injected hemoglobin (globin) or hemoglobin digests contribute to the body protein pool and from this pool various proteins emerge to supply protein requirements of tissue or organ cells or to produce new hemoglobin or plasma protein if needed. We have no explanation as to what determines the pattern of this protein flow but new hemoglobin is very high on the priority list. PMID- 19871467 TI - THE SYNTHESIS, STORAGE, AND EXCRETION OF CREATINE, CREATININE, AND GLYCOCYAMINE IN PROGRESSIVE MUSCULAR DYSTROPHY AND THE EFFECTS OF CERTAIN HORMONES ON THESE PROCESSES. AB - The diminished excretion of creatinine in progressive muscular dystrophy is a more striking and specific phenomenon than the excess excretion of creatine, marked though this is. While creatinuria is invariably encountered in all cases of long-standing dystrophy, the extent to which the excretion of creatinine is decreased provides a more reliable indication of the severity of the disease since an excess output of creatine may occur physiologically in normal human subjects and in many pathological conditions not known to be associated with muscle disease. In progressive muscular dystrophy the residual muscle mass, as inferred from the excretion of creatinine, provides a useful index of the state of the disease at any given time. Although there is excessive creatinuria in progressive muscular dystrophy, there is no evidence that a deprivation of methyl stores occurs through a loss of urinary creatine. The loss of methyl groups contained in the excess creatine is, under ordinary conditions of diet, almost exactly compensated for by a drop in the excretion of methyl groups in the urinary creatinine. Testosterone propionate, administered over variable periods of time, resulted in the retention of creatine both in normal male children and in male children with progressive muscular dystrophy, as shown in the normal subjects by a diminution in creatine output, and in both by an excess creatinuria for variable periods of time following withdrawal of the hormone. An increase in the excretion of creatine in progressive muscular dystrophy occurred following the administration of methyl testosterone. Neither testosterone propionate nor methyl testosterone appeared to effect any consistent change in the output or urinary creatinine. No effects on the excretion of creatine and creatinine were observed following the prolonged administration of concentrate of gonadotropic and thyrotropic principles of the hypophysis, or from the administration of desoxycorticosterone acetate to patients with progressive muscular dystrophy. Except in one case, in which marked improvement was observed following the administration of testosterone propionate, no effects on the clinical course of the patients with progressive muscular dystrophy were observed as a result of treatment by any of the various hormones employed in this study. PMID- 19871468 TI - TOLERANCE TO AMINO ACID MIXTURES AND CASEIN DIGESTS GIVEN INTRAVENOUSLY : GLUTAMIC ACID RESPONSIBLE FOR REACTIONS. AB - Several synthetic mixtures of natural and racemic crystalline amino acids suitable for the daily nitrogen requirement are tested in dogs for their tolerance upon intravenous injection. Certain mixtures of the ten essential amino acids plus non-essential amino acids exclusive of glutamic acid are accepted without any obvious sign of disturbance even at rates above 10 mg. nitrogen per kilo per minute for quantities greater than 300 mg. per kilo. One such mixture consists in parts per 100 of dl-threonine 7, dl-valine 15, l(-)-leucine 10.9, dl isoleucine 9.9, l(+)-lysine. HCl.H(2)O 10.9, dl-tryptophane 3, dl-phenylalanine 9.9, dl-methionine 6, l(+)-histidine.HCl.H(2)O 5, l(+)-arginine-HCl 5, glycine 9.9, dl-alpha-alanine 4, dl-serine 2, l(-)-cystine 0.5, and l(-)-tyrosine 1. In addition other well tolerated mixtures included the prolines. When glutamic acid, natural or racemic, is included in similar mixtures vomiting reactions frequently occur at nitrogen rates above 4 mg. per kilo per minute. Vomiting almost always occurs on the first daily injection containing glutamic acid and usually on any subsequent injection containing more than 100 mg. glutamic acid per kilo unless given very slowly. Upon the addition of glycine certain mixtures of the ten essential amino acids show an improved tolerance. Two casein digests tested usually produced vomiting at injection rates above 2 mg. nitrogen per kilo per minute, probably because of their glutamic acid content. No serious reaction has ever occurrred to any mixture of amino acids or casein digest tested. Elimination of minor reactions such as vomiting appears possible and desirable for greater usefulness of these solutions in parenteral feeding. PMID- 19871469 TI - A COMPARISON OF HUMAN AND GUINEA PIG COMPLEMENTS AND THEIR COMPONENT FRACTIONS. AB - 1. Defects in methods previously proposed for the estimation of complement components are: failure to ensure an excess of the desired components and failure to ensure absence of anticomplementary effects in the dilution ranges used. Existing data are therefore subject to these uncertainties. 2. Methods are proposed for controlling the adequacy of the reagent for each component, for using it in dilutions below its anticomplementary range, and for reinforcing it with necessary components if these are present in inadequate amounts. 3. Titrations are given of the four components in human and guinea pig complements and in "midpiece," "endpiece," and in the various reagents used, including one with C'3 reactivity, solely, and one withC'4 reactivity. 4. C'3 is shown to be the component which usually limits the titer in guinea pig complement, and C'2 the component of lowest titer in human complement. 5. In immune hemolysis, each component of human complement may be replaced by the corresponding component of guinea pig complement and vice versa. PMID- 19871470 TI - THE REGENERATIVE CYCLE OF MOTONEURONS, WITH SPECIAL REFERENCE TO PHOSPHATASE ACTIVITY. AB - 1. The regenerative cycle of motoneurons after axon amputation is described, and an attempt made to correlate morphological and chemical events in cell bodies with the growth requirements of regenerating axons. 2. The "normal" pattern of Nissl material in the cell is considered to be the resultant of a steady state in cytoplasmic nucleoprotein. Chromatol is then interpreted as a shift of the balance of nucleoprotein turnover in fa of degradation. The rapid early depletion of Nissl substance in chromatolysis is ascribed to the increased growth requirements created by the active early sprouting of the regenerating axon. Acid phosphatase activity begins to increase above normal levels during this period in the region of nucleopro degradation. 3. The recovery period of chromatolysis due to axon section coincide in time with the phase of gradual lengthening of the regenerating axon, and is thought to represent a gradual restoration of the balance of nucleoprotein degradation and synthesis. During this period acid phosphatase activity is at its height in the region of transformation of Nissl substance, later declines to normal levels when the original pattern of Nissl bodie is restored. 4. The transformation of cytoplasmic nucleoprotein which occurs in chromatolysis after axon section, with the probable liberation (46), and depletion (44), of nucleotides, associated with acid phosphatase activity, suggests the hypothesis that liberated nucleotides or nucleotide compounds may pass down the axon in which they take part in enzymatic activity associated with growth and organization of the newly formed axon. This type of activity would not be incompatible with the ideas previously expressed (30, 81) of a continual function of Nissl substance in maintaining the integrity of the large volume of cytoplasm represented by the axon, as well perhaps as the associated myelin sheath. PMID- 19871471 TI - CYTOCHROME OXIDASE IN NORMAL AND REGENERATING NEURONS. AB - Manometric determinations of cytochrome oxidase activity were carried out on grey matter from the thalamus and anterior horn of cats and monkeys under various experimental conditions. The thalamus of the cat was studied following the degeneration of virtually all the thalamic neurons secondary to decortication. In comparing the deneuronated thalamus with the normal one, it was found that approximately 34 per cent of the cytochrome oxidase activity was contributed by the neurons and the balance by neuroglia and mesodermal tissues which on the operated side remained comparable to that of the normal side. Total activity of the normal thalamus averaged 5.52 units per mg. of dry weight where I unit is defined as the amount of cytochrome oxidase required to produce a net oxygen consumption of 10 c.mm. per hour under the specified conditions of the experiment. The grey matter of the anterior horns of the spinal cord was isolated by a special technique and its cytochrome oxidase activity was compared with anterior horns in which motoneurons had been stimulated to regenerative activity by section of peripheral nerves. Each animal was studied in relation to an anterior horn which was normal and one in which only the functional state of the motoneurons had been changed. Average normal levels of 2.23 units were found for cat anterior horn and 0.69 units for the monkey. Reductions of cytochrome oxidase activity in the range of 22 to 23 per cent were observed for both cat and monkey following nerve section. In the latter the time sequence was carefully studied in relation to the cytological cycle known as chromatolysis and a virus refractory state previously described by us. It was found that maximal reduction of cytochrome oxidase activity coincided with maximal refractoriness of the cells to poliomyelitis virus (30 to 70 days following nerve section). Neither of these states could be correlated in time with maximal chromatolysis (10 to 15 days). PMID- 19871472 TI - REVERSIBLE INACTIVATION OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES. AB - 1. The transforming substance of Pneumococcus Type III is inactivated by treatment with ascorbic acid. This effect of ascorbic acid is catalyzed by traces of cupric ion and is prevented by the presence of sulfhydryl compounds. 2. Under certain conditions, the activity of transforming substance treated with ascorbic acid can be restored by the use of glutathione and other sulfhydryl compounds. 3. Other compounds, such as catechol, hydroquinone, and p-phenylenediamine, which undergo autoxidation similar to that of ascorbic acid, have an analogous effect on the transforming substance. 4. The effect of these compounds on the transforming substance is nullified by exclusion of oxygen or by the use of catalase. 5. It is concluded that inactivation of the transforming substance is probably oxidative in character and depends on the formation of peroxides in the course of autoxidation of ascorbic acid or related compounds. 6. The relation of this phenomenon to that of the inactivation of other biologically active substances by ascorbic acid is discussed. PMID- 19871473 TI - PLASMA PROTEIN METABOLISM-ELECTROPHORETIC STUDIES : RESTORATION OF CIRCULATING PROTEINS FOLLOWING ACUTE DEPLETION BY PLASMAPHERESIS. AB - Electrophoretic patterns of normal dog plasma in veronal buffer at pH 8.5 are shown to be essentially similar to patterns of human plasma. Dog albumin has a higher mobility than human albumin and in a mixture of dog and human plasmas migrates as a partially separated peak. Normal dog plasma frequently shows four alpha globulin peaks. Rates of restoration of plasma protein components in dogs subjected to acute plasmapheresis have been studied by electrophoresis. During the first 24 hours following such acute depletion, appreciable quantities of all electrophoretic components of the plasma proteins enter the circulating blood stream even when food is not given and has not been given for 12 hours before plasmapheresis. In such fasting periods albumin and total globulin appear in approximately the proportions present in normal plasma. Alpha and beta globulins continue relatively elevated during subsequent days in which caloric and protein intakes are adequate for weight and nitrogen gains. Initial albumin levels, however, are regained more slowly than those of total globulin. The relative proportions of the electrophoretic components of plasma proteins may be disturbed from normal following a single acute depletion for as long as 2 to 3 weeks after the total protein level has returned to normal. Abnormally high beta globulin and fibrinogen, but a low albumin, were found in a dog with an acute and chronic cholangitis and hepatitis. Similar elevation of gamma globulin was noted in a dog in which a hemolytic reaction occurred. PMID- 19871474 TI - A COMPARISON OF THE EFFECTS OF PYRIDOXINE AND PANTOTHENIC ACID DEFICIENCIES ON THE NERVOUS TISSUES OF SWINE. AB - 1. When pigs were fed diets deficient in pyridoxine or pantothenic acid, ataxia developed and lesions were found in the sensory neuron. 2. The morphological pattern of the lesions differed in the early stages of the two deficient states. Degeneration of the peripheral process of the sensory neuron was the initial and most prominent feature in pyridoxine deficiency. Chromatolysis was the first evidence of damage to the afferent neuron in pantothenic acid-deficient animals. 3. The possible significance of this evidence of damage to different portions of the sensory neuron is discussed. PMID- 19871475 TI - CELLULAR DYNAMICS IN THE INTESTINAL MUCOSA: THE EFFECT OF IRRADIATION ON EPITHELIAL MATURATION AND MIGRATION. AB - Although irradiation of the duodenum of rats inhibits mitosis in the crypts and halts the normal passage of cells up the villi, the maturation of goblet cells is not affected. The ripening of mucous elements while arrested in the crypts, where they form, instead of during their migration along the villi, results in the so called mucous change, which has hitherto been considered a form of degeneration. During the phase of recovery, the reestablishment of normal migration and desquamation is marked by the appearance of strata of fully formed goblet cells at successive levels out along the villi. It is suggested that some gastrointestinal disturbances known to occur in spontaneous and experimental vitamin deficiency might be explained in terms of aberrations in the cellular replacement of the intestinal mucosa. PMID- 19871476 TI - INDIVIDUAL BLOOD DIFFERENCES IN MEXICAN INDIANS, WITH SPECIAL REFERENCE TO THE Rh BLOOD TYPES AND Hr FACTOR. AB - 98 Mexican Indians were tested for the blood properties A-B-O, A(1)-A(2), M-N, P, Rh'-Rh''-Rh(0)-rh, and Hr. Of the 98 Indians, 90.8 per cent belonged to group 0, 6.1 per cent belonged to A(1), and 3.1 per cent to group B. There were 61.2 per cent of type M, 3.1 per cent of type N, and 35.7 per cent of type MN. Of the 95 Mexican Indians tested with anti-P serum, 21.1 per cent were found to lack the P agglutinogen. In tests for the Rh blood types, 48.0 per cent of the Indians were found to belong to type Rh(1), 9.2 per cent to type Rh(2), 41.8 per cent to type Rh(1)Rh(2), and 1 per cent to type Rh(0). There were no bloods giving intermediate reactions. Of the 95 Indians tested for the Hr factor 44.2 per cent were found to lack this property. The reactions for the Rh blood types and Hr factor were correlated with each other and the results supported the conclusion of Race et al. that in addition to the six standard allelic genes and the so called intermediate genes, there is one or possibly two genes having the property of determining agglutinogens which react with anti-Rh' and anti-Rh'' sera, but not with anti-Hr serum. This gene (or genes) appears to be relatively common among Mexican Indians (approximately 3.3 per cent) in contrast to its rareness in white individuals. PMID- 19871477 TI - A PROTEOLYTIC ENZYME PRODUCED BY GROUP A STREPTOCOCCI WITH SPECIAL REFERENCE TO ITS EFFECT ON THE TYPE-SPECIFIC M ANTIGEN. AB - 1. Group A streptococci sometimes produce in broth culture an extracellular proteolytic enzyme. 2. Under suitable cultural conditions the enzyme has been demonstrated in representative cultures of most of the Griffith types. Its production by a given strain may be suppressed by serial passage through mice and the variant so produced has been found to maintain this change in character on subculture in artificial media. 3. Under certain conditions, the enzyme attacks the type-specific M antigens of all the group A streptococci so far tested, with the exception of that of type 28. The enzyme exhibits its maximal activity at 37 degrees C.: Extracts made from enzyme-producing cultures which have been grown at this temperature lack the M antigen; enzyme-producing strains may sometimes be induced to yield M substance in extracts by culturing the streptococci at 22 degrees C. Cultures which, when grown at 37 degrees C. yield M substance in extracts, do not produce the enzyme. 4. Human and rabbit fibrin are attacked and streptococcal fibrinolysin is also inactivated by the enzyme. Other susceptible substrates include casein, milk, gelatin, and benzoyl-l-arginineamide but not l leucylglycylglycine. 5. The general properties of the enzyme resemble those of papain and some of the cathepsins: It is active under the reducing conditions produced in broth cultures by the presence of living bacteria; it is also activated by substances which reduce disulfide to sulfhydryl groups, e.g. potassium cyanide, cysteine, glutathione, and thioglycollic acid, but it is not activated by ascorbic acid. The enzyme is inactivated by iodoacetic acid and also by normal rabbit or mouse serum. PMID- 19871478 TI - LOSS OF GROUP CARBOHYDRATE DURING MOUSE PASSAGES OF A GROUP A HEMOLYTIC STREPTOCOCCUS. AB - In the course of rapid passages through mice a strain of group A type 27 hemolytic streptococcus was found to have lost its group carbohydrate without the loss of type-specific precipitinogens, agglutinogens, or its capacity to induce protective antibodies in rabbits, and without the acquisition of the carbohydrate of another group. The loss of group carbohydrate was shown to be complete, within the limits of the methods for its detection. Extracts of the anomalous strain did not react with group A antisera; and antisera prepared with organisms of this anomalous strain did not contain demonstrable antibodies for the group carbohydrate. Bacterial suspension of the anomalous strain failed to absorb any appreciable amount of group-specific antibody. The fact that the anomalous strain lacking group-specific carbohydrate, C, was derived from the original was established by the demonstration of persistence of its other characteristics, in particular the precipitinogens, agglutinogens, and antigens responsible for protective antibodies of type 27. PMID- 19871479 TI - THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : I. THE FINDINGS WITH SKIN OF C STRAIN EMBRYOS TRANSPLANTED TO ADULT ANIMALS. AB - A method has been devised whereby the transplanted epidermis of mouse embryos can be selectively exposed to the action of a chemical carcinogen. Scharlach R was dissolved in olive oil with the aim of stimulating and attracting the epidermal cells, methylcholanthrene was added to the solution, and numerous fine globules of it were injected into the thigh muscles of adult mice together with fragments of embryo skin. Much of the oil underwent primary inclusion in the resulting cysts, and the proliferating epidermis, while forming them, extended to not a few of the outlying droplets with result that they too were added to the cyst contents. During these activities the methylcholanthrene came into direct contact with many of the epithelial cells, and later on the layer lining the cyst was continually exposed to the influence of the carcinogen. The epidermis underwent neoplastic changes with great rapidity; often in less than 4 weeks papillomas and carcinomas had arisen like those deriving from adult epidermis. The growths were punctate in origin and usually multiple. Many were transplanted to adults of the same homologous breed of mice that furnished the embryo material (mice of C strain). The grafts did not uniformly succeed as was the case with those of normal skin of embryos of the same stock,-which regularly grew at first in the new hosts and remained alive long after. The benign papillomas failed to live or barely survived, and the apparently malignant papillomas, though rapidly forming nodules of considerable size, usually regressed later. Some of the carcinomas also regressed or wholly failed, while others gave rise to progressively enlarging tumors. The best results were obtained with grafts in which several neoplasms were intermingled, these flourishing together in the new hosts. Methylcholanthrene in olive oil exerts an influence on epidermal cells like that of Scharlach R, stimulating them to multiply, attracting them, and causing them to mimic carcinomatous elements. PMID- 19871480 TI - THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : II. CONTRIBUTORY EXPERIMENTS; RESULTS WITH THE SKIN OF C3H AND WEBSTER-SWISS EMBRYOS; GENERAL CONSIDERATIONS. AB - Experiments were carried out to learn whether the widely differing liabilities to induced epidermal tumors of individual mice and rabbits are due to a previous localization out of the blood of an agent capable of undergoing change when the skin is exposed to carcinogenic influences, and of producing tumors in consequence. On the assumption that such an agent would localize in increased quantity where cutaneous inflammation exists, like various inert substances of large molecule and the epidermotrophic viruses when circulating, skin areas on adult and new-born animals were for some weeks kept inflamed, and months later, when the areas appeared normal, methylcholanthrene was applied to them and to control areas on the same or other individuals. No differences were observable in tumor incidence. These results led to attempts to test whether embryo epidermis is capable of undergoing neoplastic change, and the work of Paper I was done which showed that epidermal tumors arise with great rapidity and regularity from embryo skin transplanted to adults of homologous strain (C strain) together with methylcholanthrene. Webster-Swiss mice proved unsuited to experiments of the sort owing to heterogeneity of the breed, the transplanted embryo skin dying in most instances before the methylcholanthrene introduced with it could have been carcinogenic. The skin of C3H embryos also did badly, as if from incompatibility in some instances but mostly because its epidermal cells proliferated less vigorously than those of C embryos and did not tolerate methylcholanthrene nearly so well. Despite these difficulties, epidermal tumors were occasionally induced, as also in the transplanted skin of Webster-Swiss embryos, and the growths appeared quite soon, all things considered. The effect of methylcholanthrene on the skin of sucklings, their mothers, and young adult mice of the C strain was studied in order to find out whether the rapid rate of neoplastic change in the transplanted epidermis of embryos is indicative of some liability connected with its period of development. The skin of new-born animals proved very refractory to the carcinogen, hair coming in at the same rate as on control litters and no perceptible inflammation occurring for about 2 weeks, although within this period the mothers of the treated animals and the young adults became hairless where the methylcholanthrene had been put and their skin was much inflamed. Later on, as the applications were kept up, similar changes took place in the sucklings, but none of these developed tumors during some 6 weeks of observation whereas growths appeared within 3 weeks on more than half of the mother mice and on some of the young adults. The failure to produce tumors in the sucklings seems to have been due to cutaneous conditions preventing the necessary exposure of the deeper epidermal cells to methylcholanthrene. In any projected correlation of age differences with the response of cells to carcinogens allowance must be made for such factors. The present findings give no ground for the supposition that embryo skin has any special liability to neoplastic change. The results of transferring the tumors derived from embryo epidermis to new hosts have made plain that the neoplastic state not infrequently entails disabilities which are crucial, the tumor cells failing to succeed unless aided. This holds true of some carcinomas as well as of papillomas. By transplanting pieces of the organs of C embryos together with methylcholanthrene tumors of many sorts besides the epidermal have been obtained. As yet only those of the stomach have been worked with extensively. They can be elicited as quickly and regularly as those of the epidermis and can be as easily transplanted. The findings as a whole render it impossible to suppose that the neoplastic potentialities possessed by transplanted embryo tissues are due to the lodgement in them of tumor-producing viruses as specialized in their effects as those now known, or of precursor agents conferring neoplastic liabilities specialized to the same degree. Some other possibilities are mentioned. The rarity of neoplasms at birth is due to the circumstances of intrauterine life and to its brevity, not to any lack of capacity of the cells of the embryo to undergo neoplastic change. PMID- 19871481 TI - STUDIES ON THE DENATURATION OF ANTIBODY : II. THE EFFECT OF PROTEIN CONCENTRATION ON THE RATE OF DENATURATION OF DIPHTHERIA ANTITOXIN BY UREA. AB - The specific rate of inactivation of antitoxin in urea solutions, as measured by the Romer neutralization test with toxin, has been shown to be independent of the concentration of protein under the conditions studied. The amount of precipitate obtained in the quantitative precipitation test with toxin, however, increases greatly with increasing protein concentration during denaturation. The time during which the protein concentration is important in this respect has been shown to be the interval in which the urea is being dialyzed from the solutions. The meaning of the results is discussed. PMID- 19871482 TI - THE EXPERIMENTAL INFECTION OF THE HUMAN BODY LOUSE, PEDICULUS HUMANUS CORPORIS, WITH MURINE AND EPIDEMIC LOUSE-BORNE TYPHUS STRAINS. AB - Experiments are described which demonstrate that human body lice (Pediculus humanus corporis), were infected experimentally with murine and epidemic louse borne strains of typhus fever by feeding on suitably prepared rabbits. Details of the two methods of infection, the "bleb technique" and the "I.V. technique," are presented. It is concluded that the experimental infection of human lice with typhus can be accomplished very easily and rapidly with these methods. The possible applications of the method are discussed. PMID- 19871483 TI - INDUCED ANTIBODIES THAT REACT IN VITRO WITH SEDIMENTABLE CONSTITUENTS OF NORMAL AND NEOPLASTIC TISSUE CELLS : PRESENCE OF THE ANTIBODIES IN THE BLOOD OF RABBITS CARRYING VARIOUS TRANSPLANTED CANCERS. AB - Antibodies were found in the blood of certain rabbits carrying one or another of four transplanted cancers (Brown-Pearce and V2 carcinomas; RSI and Kato sarcomas) which will fix complement in vitro in mixture with saline extracts of various normal and neoplastic rabbit tissues-including liver, kidney, spleen, and the four tumors mentioned-and chick embryo tissue as well. These antibodies, which have been called induced tissue antibodies, are similar to the natural antibodies previously described (2) in that they react with those constituents of the various tissue cells that prove readily sedimentable in the high speed centrifuge; they differ from the natural antibodies in being absent from the blood of normal rabbits and in withstanding 65 degrees C. for 30 minutes. Certain quantitative differences suggest that the induced tissue antibodies have somewhat various affinities, depending in part upon the type of neoplasm carried by the host. They may perhaps be consequent on antigenic differences between the sedimentable constituents of the tumor cells and those of the new hosts; for they were not found in the blood of rabbits carrying papillomas and cancers composed of the animals' own cells, and not in that of rabbits in which multiple vaccinia or fibroma virus lesions had recently regressed. The characters of the sedimentable constituents of normal and neoplastic tissue cells, as revealed thus far by chemical, morphological, and serological studies, have recently been discussed (2,8). In this relation, it has seemed essential to recognize the induced antibodies here described, particularly since they may complicate serological studies aimed at disclosing distinctive sedimentable substances in tissue cells. In an associated paper experiments are reported which bear upon the relation between the induced tissue antibodies and an antibody that reacts specifically with a distinctive sedimentable constituent of Brown-Pearce carcinoma cells (7). PMID- 19871484 TI - INCIDENCE AND SPECIFICITY OF THE ANTIBODY FOR A DISTINCTIVE CONSTITUENT OF THE BROWN-PEARCE TUMOR. AB - A detailed study has been made of an antibody which appears in the blood of certain rabbits implanted with the Brown-Pearce carcinoma or injected with extracts of it and which reacts specifically in vitro in mixture with a distinctive sedimentable constituent of the Brown-Pearce tumor cell. The observations as a whole seem to indicate that this constituent of the Brown Pearce tumor differs notably from certain other sedimentable substances which can be extracted from various rabbit tissues and identified by serological means. The implications of the findings are discussed. PMID- 19871485 TI - PROTEIN METABOLISM AND PROTEIN RESERVES DURING ACUTE STERILE INFLAMMATION : HIGH PROTEIN INTAKE COMPENSATES FOR INCREASED CATABOLISM. AB - Adult dogs were given a proteinless diet plus casein, 80 calories/kilo, 0.4 gm. nitrogen/kilo/day. Sterile controlled inflammation was produced by subcutaneous injection of turpentine. The reaction is characterized by local swelling, induration, and abscess formation, terminated by rupture or incision after 3 to 5 days and by general reactions of malaise, fever, leucocytosis, and increased urinary nitrogen. For 3 to 6 days after turpentine the nitrogen intake was provided in seven experiments by amino acids given parenterally (a solution of the ten essential amino acids (Rose) plus glycine). A normal dog with a normal protein intake showed a negative nitrogen balance after turpentine-urinary nitrogen doubled even as in inflammation during fasting. A protein-depleted dog (low protein reserves produced by very low protein intake) given a normal protein intake after turpentine maintained nitrogen balance-urinary nitrogen rose only slightly. With a high (doubled) protein intake the depleted dog showed strongly positive balance. Normal dogs with high (doubled) protein intakes react to turpentine with doubled urinary nitrogen outputs on individual days and therefore are maintained in approximate nitrogen balance and weight balance. This end may be achieved equally well or better by oral feeding, when such is possible and absorption unimpaired. The increased nitrogen excretion after injury is again shown directly related to the state of body protein reserves. Increased catabolism not inhibition of anabolism best explains the excess urinary nitrogen. Protection during injury of valuable protein reserves appears possible through an adequate intake of protein nitrogen. PMID- 19871486 TI - BACTERIOSTATIC EFFECT OF HUMAN SERA ON GROUP A STREPTOCOCCI : II. COMPARATIVE BACTERIOSTATIC EFFECT OF NORMAL WHOLE BLOOD FROM DIFFERENT ANIMAL SPECIES IN THE PRESENCE OF HUMAN CONVALESCENT SERA. AB - 1. Heparin was more satisfactory for preventing blood from clotting than defibrination, potassium and ammonium oxalate, or sodium citrate in bacteriostasis of group A streptococci in the presence of streptococcal antibodies in convalescent serum. 2. Blood from rabbit, guinea pig, or sheep could not be substituted for human blood in promoting bacteriostasis when human antibody was used. Mixtures of human leukocytes and plasma of each of these animals or of animal leukocytes and human plasma were also not effective with human antibody. 3. Complement, leukocytes, and a thermostable factor which was found in human plasma were essential in the indirect bacteriostatic technique employed for the inhibition of streptococcal growth in the presence of convalescent human serum. 4. The thermostable component was active in human serum, as well as in plasma, in 1:12 dilution, withstood storage at 4 degrees C. for at least 7 weeks, and was destroyed by heating at 70 degrees C. for 30 minutes. PMID- 19871487 TI - BACTERIOSTATIC EFFECT OF HUMAN SERA ON GROUP A STREPTOCOCCI : III. INTERFERENCE WITH BACTERIOSTATIC ACTIVITY BY BLOCKAGE OF THE LEUKOCYTES. AB - 1. Type-specific M extracts and group-specific C carbohydrate of group A streptococci inhibited bacteriostasis of these microorganisms in the presence of normal whole blood and of sera from patients convalescent from streptococcal infections. The inhibition was not specific with respect to streptococcal types and depended merely on the formation of precipitates in the system. The extracts had no antagonistic action in themselves. 2. Preformed precipitates derived from the interaction of an antigen and its homologous antibody or from finely divided coagulated particles of human plasma or ascitic fluid also interfered with the bacteriostasis. The supernatant fluid in which one of these precipitates was formed did not inhibit bacteriostatic activity; therefore, it seems that other possible products of the antigen-antibody reaction were not inhibitory. The relative size of the precipitate particles was a conditioning factor since small particles of one precipitate inhibited bacteriostasis, but large ones of the same precipitate failed to do so. 3. Stained films of blood cells treated with antigen antibody mixtures which formed a precipitate revealed large cytoplasmic vacuoles containing precipitates in the polymorphonuclear leukocytes and monocytes; such engorged cells subsequently failed to phagocytize streptococci in homologous serum. Blood cells treated in the same manner, except that the antigen-antibody mixtures formed no precipitate, contained no vacuoles, and these cells were able to phagocytize the streptococci. 4. Leukocytes studied in the living state in the presence of colored precipitate and streptococci sensitized by convalescent human serum showed unselective phagocytosis of both precipitate and bacteria. The capacity of these leukocytes to ingest material however was limited. 5. As a result of non-selective saturation of their phagocytic capacity in the bacteriostatic systems containing both streptococci and precipitate, the limited number of leukocytes phagocytized only a fraction of the streptococci; consequently the remainder were able to multiply. PMID- 19871488 TI - THE CHEMICAL ALTERATION OF A BACTERIAL SURFACE, WITH SPECIAL REFERENCE TO THE AGGLUTINATION OF B. PROTEUS OX-19. AB - The chemical substitution of a bacterial surface has been effected by the addition of benzene sulfonyl chloride to B. proteus OX-19. The substitution of imidazole and amino groups on the bacteria has been followed by the microelectrophoretic method. Concomitant changes in the agglutinability of substituted organisms have been observed, without appreciable change in the antibody-combining capacities of the organisms. The significance of these observations has been discussed. PMID- 19871489 TI - INVESTIGATIONS ON THE OCCURRENCE OF Rh SUBSTANCES IN AMNIOTIC FLUID. AB - 1. Rh substances are found in amniotic fluid. Not all anti-Rh sera seem to be suitable for the detection of Rh substances in amniotic fluid. Careful selection of Rh antisera, as well as quantitative considerations, determine success or failure of their demonstration. 2. The baby's Rh type and not the mother's determines the occurrence of Rh substances in amniotic fluid. 3. There are Rh secretors and Rh non-secretors. At least four out of five individuals are secretors. 4. The secretion of Rh substance into the amniotic fluid would seem to be entirely independent of the secretion of the blood group specific substances. 5. The majority of Rh-positive amniotic fluids seem to contain both Rh(1) and Rh(2) substances. However, in certain instances fluids belonging to the pure Rh(1) type or pure Rh(2) type were found. 6. Three cases of erythroblastosis were described. All three came from Rh-negative mothers with Rh-positive babies. The amniotic fluids of all three failed to reveal the presence of Rh substances. PMID- 19871490 TI - PLASMA PROTEIN PRODUCTION INFLUENCED BY AMINO ACID MIXTURES AND LACK OF ESSENTIAL AMINO ACIDS : A DEFICIENCY STATE RELATED TO UNKNOWN FACTORS. AB - When blood plasma proteins are depleted by bleeding with return of red cells suspended in saline (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and intoxication and probably to vitamin deficiency. When the diet nitrogen is provided by certain mixtures of the ten growth essential amino acids plus glycine, given intravenously at a rapid rate, plasma protein production is good. The same mixture absorbed subcutaneously at a slower rate may be slightly better utilized. Fed orally the same mixture is better utilized and associated with a lower urinary nitrogen excretion. An ample amino acid mixture for the daily intake of a 10 kilo dog may contain in grams dl threonine 1.4, dl-valine 3, dl-leucine 3, dl-isoleucine 2, l(+)-lysine.HCl.H(2)O 2.2, dl-tryptophane 0.3, dl-phenylalanine 2, dl-methionine 1.2, l(+) histidine.HCl.H(2)O 1, l(+)-arginine.HCl 1, and glycine 2. Half this quantity is inadequate and not improved by addition of a mixture of alanine, serine, norleucine, proline, hydroxyproline, and tyrosine totalling 1.4 gm. Aspartic acid appears to induce vomiting when added to a mixture of amino acids. The same response has been reported for glutamic acid (8). Omission from the intake of leucine or of leucine and isoleucine results in negative nitrogen balance and rapid weight loss but plasma protein production may be temporarily maintained. It is possible that leucine may be captured from red blood cell destruction. Tryptophane deficiency causes an abrupt decline in plasma protein production. No decline occurred during 2 weeks of histidine deficiency but the urinary nitrogen increased to negative balance. Plasma protein production may be impaired during conditions of dietary deficiency not related to the protein or amino acid intake. Skin lesions and liver function impairment are described. Unidentified factors present in liver and yeast appear to be involved. PMID- 19871491 TI - BACTERIOSTATIC EFFECT OF HUMAN SERA ON GROUP A STREPTOCOCCI : I. TYPE-SPECIFIC ANTIBODIES IN SERA OF PATIENTS CONVALESCING FROM GROUP A STREPTOCOCCAL PHARYNGITIS. AB - 1. Type-specific antibodies were demonstrated by the indirect bacteriostatic test in sera from human adults convalescing from group A streptococcal infection of the upper respiratory tract. The time of appearance of the antibodies varied from 3 to 5 weeks; and they persisted in 2 patients for at least 37 weeks after the onset of the infection. 2. The specificity of the antibody response in one serum was tested with strains of 7 heterologous types; in another, with 6; and in the third, with 2; but in no instance were cross-reactions observed. Moreover, each convalescent serum showed approximately equal bacteriostasis for 7 different strains of the same type as that which caused the infection. 3. The antibodies were specifically absorbed from the serum by homologous heat-killed streptococci, but not significantly by strains of heterologous types. 4. The specific M antigen of the streptococcal cell with its respective antibody, and not the T substance, appeared to be concerned in the reaction. 5. In spite of numerous technical difficulties inherent in the method, this bacteriostatic test provides a useful procedure for studying type-specific immunity in streptococcal infections. PMID- 19871492 TI - PLASMA PROTEIN METABOLISM-ELECTROPHORETIC STUDIES : CHRONIC DEPLETION OF CIRCULATING PROTEINS DURING LOW PROTEIN FEEDING. AB - The findings on electrophoretic analysis of plasma proteins during many weeks of low protein feeding in dogs accord in general with those of chemical analysis as concerns the alterations in plasma albumin and globulin concentrations. Long continued restriction of dietary protein results in decreased albumin levels while plasma globulin concentrations remain essentially normal. The degree of depletion of electrophoretic albumin is, however, considerably greater than that of chemical albumin. When large amounts of protein are fed to such depleted dogs complete restoration of normal plasma albumin concentrations requires several weeks. During these weeks large quantities of nitrogen are retained, presumably as tissue protein reserves. Prompt production of plasma globulin is apparent during such periods. These relationships are more clearly shown in electrophoretic than in chemical analyses and are more conspicuous when only moderate protein intakes are fed. These data may indicate that plasma globulins and certain tissue proteins, in contrast to plasma albumin, enjoy prior demands on the total available pool of body protein materials under emergency conditions. Total electrophoretic globulin areas are increased during depletion. Such increases result largely from elevated alpha globulin peaks and are not disclosed by chemical analysis. They are found to be associated with elevated plasma lipid levels which occur in these depleted dogs. These experiments suggest that in potency tests for dietary protein materials, factors other than the quality of fed protein may influence the relative production of plasma albumin and globulin. PMID- 19871493 TI - PLASMA PROTEIN PRODUCTION AS INFLUENCED BY PARENTERAL PROTEIN DIGESTS, VERY HIGH PROTEIN FEEDING, AND RED BLOOD CELL CATABOLISM. AB - When blood plasma proteins are depleted by bleeding, with return of the washed red cells (plasmapheresis), it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and to certain intoxications. Certain protein digests given by vein may favor good production of plasma protein, as well as nitrogen and weight equilibrium, over long periods in these standardized dogs. These digests may be equally effective when given subcutaneously or intraperitoneally and more effective orally (one dog). Certain other digests may not be well utilized. The total nitrogen of the protein digests is better retained upon oral feeding than parenteral injection. Most of the excess nitrogen excretion is not in the urea and ammonia fraction of the urine. The rate of plasma protein production may reach as high as 1 gm./kilo/day in the dog when ample protein of good quality is fed. The products of catabolism of red blood cells in vivo may add to the production of plasma protein, at least during the administration of casein digest by vein. PMID- 19871494 TI - EFFECT OF ENZYME INHIBITORS AND ACTIVATORS ON THE MULTIPLICATION OF TYPHUS RICKETTSIAE : II. TEMPERATURE, POTASSIUM CYANIDE, AND TOLUIDIN BLUE. AB - The time of blending the rickettsial inoculum, as also the strain of hen's egg employed, influenced the degree of infection which developed in fertile eggs after the injection of typhus rickettsiae into the yolk sac. By varying these factors, maximal or minimal infections could be obtained. Eggs incubated at 40 degrees C. developed only minimal rickettsial infection, whereas control eggs incubated at 37.5 degrees C. became heavily infected. Potassium cyanide markedly enhanced rickettsial growth in experiments in which the control eggs developed only minimal infection. Under circumstances such that the control eggs became heavily infected, KCN had no appreciable effect. Toluidin blue and methylene blue delayed the development of rickettsial infection in the yolk sac, but their rickettsiostatic action under the conditions of these experiments was less marked than that of penicillin and para-aminobenzoic acid. The rickettsiostatic action resulting from temperature elevation was neutralized by KCN, and hence is believed to be due to the increased activity of the cyanide-sensitive respiratory enzyme (cytochrome oxidase) in the entodermal cells in which the rickettsiae multiply. The rickettsiostatic action of toluidin blue and methylene blue, though probably also resulting from increased metabolic activity in the entodermal cells, was not neutralized by KCN. This observation is in harmony with the reported observation that dyes of this type furnish an alternative mechanism for intracellular oxidation which is cyanide-insensitive. The rickettsiostatic action of para-aminobenzoic acid was not neutralized by KCN. No conclusions can be reached at present concerning the mechanism of action of this compound. Dinitrophenol and several compounds related to para-aminobenzoic acid gave negative results. PMID- 19871495 TI - IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : I. ESTIMATION OF A AND B ISOANTIBODIES IN HUMAN SERUM BY THE QUANTITATIVE PRECIPITIN METHOD. AB - 1. With purified blood group A and B specific substances from the gastric mucin of pigs precipitin reactions can be obtained in sera containing homologous isoagglutinins. By microquantitative precipitin technics the anti-A and anti-B content of normal and immune isoagglutinin-containing sera can be estimated on a weight basis. 2. There was a general correlation between antibody N precipitable from the sera of groups O and B by A substance and the agglutinin titer for A erythrocytes before and after immunization with blood group substances. 3. The reaction between A substance and its homologous isoagglutinin present in the sera of immunized individuals was of the same type as in other antigen-antibody systems. PMID- 19871496 TI - MEASUREMENT OF ANAEROBIC GLYCOLYSIS IN BRAIN AS RELATED TO POLIOMYELITIS. AB - Experiments with mouse brain, homogenates show that the anaerobic glycolysis of such preparations can be increased tenfold by addition of appropriate coenzymes and phosphate esters. The previously reported alterations in anaerobic glycolysis during poliomyelitis, as measured with low activity preparations, are believed to be of doubtful value in so far as the changes may be related to any specific phase of metabolism. In order to obtain this type of information, the experiment usually must be designed specifically to measure the desired factor. PMID- 19871497 TI - THE METABOLISM OF THE KIDNEY IN EXPERIMENTAL RENAL HYPERTENSION : II. THE CONCENTRATION OF CYTOCHROME C AND THE ACTIVITIES OF THE CYTOCHROME OXIDASE AND OF THE SUCCINIC DEHYDROGENASE SYSTEMS IN THE KIDNEY OF DOGS WITH EXPERIMENTAL RENAL HYPERTENSION. THE INHIBITORY EFFECT OF RENIN AND OF KIDNEY TISSUE PREPARATIONS FROM HYPERTENSIVE DOGS ON THE RESPIRATORY ENZYMES. AB - These investigations are part of an attempt to study and interpret the intermediary metabolism of the kidneys in experimental renal hypertension. Hypertension was produced in dogs by the clamping procedure of Goldblatt and associates or by the silk perinephritis method of Page. Enzymatic studies were made by means of Warburg's manometric method. Cytochrome c was in addition determined spectrophotometrically. Tissue slices, homogenized tissue, and tissue extracts were used. A study of the cytochrome c concentration and the activities of the cytochrome oxidase and succinic dehydrogenase systems of kidneys from normal dogs and dogs with experimental renal hypertension was made. It was found that the cytochrome c concentration and the activities of the cytochrome oxidase and succinic dehydrogenase systems were markedly lower in the kidney slices and in the tissue suspensions from hypertensive dogs. Tissue suspensions and extracts of kidneys from hypertensive dogs showed an inhibitory effect on the activity of the cytochrome oxidase and succinic dehydrogenase, and the amine oxidase systems. Renin preparations also showed a marked inhibitory effect on the activities of cytochrome oxidase, succinic dehydrogenase, l-amino acid oxidase, and amine oxidase systems. A significant increase was found in the kidney of dogs whose other kidney had been removed or subjected to Goldblatt's or Page's technique in the activities of the cytochrome-cytochrome oxidase system, the succinic dehydrogenase system, and in the concentration of nucleotide-bound phosphorus, of flavin-adenine dinucleotide, and of the nicotinamide-adenine dinucleotides (coenzymes I and II). From the results of these studies it can be concluded that an increase in the concentration and activity of the respiratory enzymes precedes hypertrophy of the kidney. This can be explained by the assumption that an increase in the activity of the respiratory biocatalysts acts as a stimulus for cell growth and multiplication. PMID- 19871498 TI - HEREDITARY ACHONDROPLASIA IN THE RABBIT : I. PHYSICAL APPEARANCE AND GENERAL FEATURES. AB - An achondroplastic condition in the rabbit has been described. It is present at birth and is characterized by size reduction, by a disproportion of bodily parts, most marked in the extremities, and by an invariably lethal effect. The animals are still-born or die very shortly after birth. In physical appearance and in the character of the skeletal changes as shown by x-ray photographs, achondroplasia in the rabbit has a remarkable resemblance to the disease in man and in cattle and dogs. The condition which first occurred in offspring of pure bred Havana rabbits is inherited. In anticipation of the later discussion of this phase of the study (13), it can be stated that the mode of inheritance is on the basis of a simple recessive unit factor and that the appearance of non-achondroplastic transmitters (heterozygotes) is that of normal animals. PMID- 19871499 TI - HEREDITARY ACHONDROPLASIA IN THE RABBIT : II. PATHOLOGIC ASPECTS. AB - Pathological observations on hereditary achondroplasia in the rabbit have been described. At autopsy, the chief features of interest are: reduced size with disproportionately shortened extremities and large head, cutaneous and subcutaneous edema of variable degree and distribution, small shortened bones with a cartilaginous appearance and texture, immature teeth, and cleft palate in one-fourth the cases; blood-stained fluid in the thoracic and abdominal cavities; a comparatively small heart pointing to the right of the midline, a very large firm thymus, a large pale soft spleen, a large swollen liver with red mottling, and a stomach distended with thin greenish mucus but no milk. The mean relative weights of all organs in terms of the net body weight were larger than those of normal new-born litter mates. The mean actual weights of the kidneys, the brain, and especially the spleen and the thymus were also larger than their respective normal values, those of the heart, liver, and adrenals were slightly smaller, while that of the pituitary was the same. Histologically, all endochondral cartilages show marked abnormalities of differentiation with pronounced deficiency of ossification. Calcification of membranous bones is likewise deficient. The histological abnormalities of the long bones are very similar to, if not identical with, those characteristic of human fetal chondrodystrophy, the creeper fowl condition, the "bull-dog" calf, and achondroplasia of the dog. No histological evidence was found in any organ which would suggest a basis for a responsible causal agent of the abnormality. Minor to marked vascular dilatation and congestion and edema is a variable feature but is fairly widely distributed. The changes in the thyroid indicate an active gland. The cellular pattern of the pituitary is characterized by some increase in basophilic cells. The lymphoid elements of the spleen are more or less depleted. The hemopoietic tissue in the spleen and liver is reduced in amount. In blood obtained from the heart, there is a reduction in the numbers of red and white cells and platelets and in the hemoglobin content as well; immature cells and particularly normoblasts are comparatively numerous. PMID- 19871500 TI - HEREDITARY ACHONDROPLASIA IN THE RABBIT : III. GENETIC ASPECTS; GENERAL CONSIDERATIONS. AB - Hereditary achondroplasia (chondrodystrophia foetalis) in the rabbit has been described in the present and preceding papers (1, 2). It is the first instance of this abnormality in rodents to be reported. The variation arose in pure bred Havana stock. The abnormality is determined by the expression of a simple recessive unit factor, affected individuals being homozygous for the factor. Females are somewhat more frequently affected than males, but the character is not sex-linked. Rabbits heterozygous for the factor as determined by appropriate breeding tests have a perfectly normal appearance at birth and in later life. The condition appears to be determined solely by the genetic constitution of the animal. Attention was drawn to the fact that although the development of the achondroplastic form proceeds to birth at term, death regularly occurs at the time of or very shortly after parturition. This feature of the condition is briefly discussed. PMID- 19871501 TI - THE PROTECTIVE ACTION OF TRYPAN RED AGAINST INFECTION BY A NEUROTROPIC VIRUS. AB - Trypan red, when injected intraperitoneally into mice, has been found greatly to lower the incidence of the infection of mice inoculated intraperitoneally with the neurotropic MM virus. The protective action of the dye is overcome if the virus is inoculated in too high concentration. The lowered incidence of infection was observed in mice inoculated with virus for as long as 29 days after the last dye injection. Of a number of dyes tested, trypan red, brilliant vital red, and Congo red were found effective. In cotton rats inoculated intraperitoneally with MM virus, trypan red was likewise found to lower the incidence of infection. With monkeys and a typical poliomyelitis virus no protection was observed against the virus inoculated intraperitoneally. The latter experiment is considered to have been inadequate for a critical test of the effect of trypan red on poliomyelitis infection. When either the MM virus or Lansing virus were inoculated intracerebrally into mice, the effect of the dye on incidence of infection was small. In the case of the Lansing virus the difference was statistically significant, however. The possible relation of alteration in the permeability of the barrier between the blood and the central nervous system as a cause of the effect of trypan red is discussed. PMID- 19871502 TI - MAXIMAL HEMOGLOBIN AND PLASMA PROTEIN PRODUCTION UNDER THE STIMULUS OF DEPLETION. AB - The maximal output ceiling for hemoglobin in anemia due to blood loss is about 60 gm. per week-the dog receiving a rich protein diet plus high iron intake. Ferrous and ferric salts are equally effective. Iron intravenously plus a rich protein diet may push this level up to 90 to 100 gm. per week. Evidently iron absorption is a limiting factor. Maximal output for hemoglobin plus plasma protein in doubly depleted dogs may reach 120 to 130 gm. per week and using intravenous iron may reach 140 to 160 gm. per week. Maximal output for plasma protein alone in hypoproteinemia due to plasmapheresis reaches 60 to 70 gm. per week but this is not the true ceiling. Technically we cannot remove the new plasma protein as fast as it is formed and the hypoproteinemia is not maintained in the face of a rich protein diet intake. Furthermore the evidence points to the protein circulating pool contributing to the accretion of tissue protein in such dogs with a strong positive nitrogen balance and weight gain. Maximal figures for hemoglobin production in anemia run close to 1 gm. hemoglobin per kilo per day. Maximal figures for new hemoglobin plus plasma protein production in anemia and hypoproteinemia using iron given intravenously, may reach 1.5 gm. blood protein per kilo per day. The actual maximal plasma protein production equals about 1 gm. per kilo per day but the true production ceiling cannot be reached by this technique, for reasons given above. PMID- 19871503 TI - STUDIES ON THE ETIOLOGY OF PRIMARY ATYPICAL PNEUMONIA : II. PROPERTIES OF THE VIRUS ISOLATED AND PROPAGATED IN CHICK EMBRYOS. AB - Experiments to determine the optimum conditions for propagation of the virus of atypical pneumonia in chick embryos are described. Variations in the activity of infected chick embryo material were investigated. The highest dilution of chick embryo suspension producing pulmonary lesions in hamsters and cotton rats is not over 10(-3). Dilutions of 10(-4) infect chick embryos. The virus is unstable at room temperature and also loses activity when stored in a dry-ice refrigerator unless the suspensions are kept in sealed glass tubes. Filtration experiments indicate a maximum particle size of 180 to 250 mmicro. The virus propagated in chick embryos produces pulmonary lesions in hamsters and cotton rats which have been immunized to their own non-bacterial agents inducing pulmonary lesions. Of these, the pneumonia virus of hamsters most frequently causes intercurrent respiratory infections, and methods of controlling epizootics due to this agent are described. PMID- 19871504 TI - STUDIES ON THE ETIOLOGY OF PRIMARY ATYPICAL PNEUMONIA : III. SPECIFIC NEUTRALIZATION OF THE VIRUS BY HUMAN SERUM. AB - Significant increases in neutralizing antibodies were demonstrated in 42 of a total of 69 persons with a clinical diagnosis of primary atypical pneumonia. Detailed titrations of virus-neutralizing antibodies in a representative group of 28 patients are presented. Increases of four- to 64-fold were demonstrated. Acute phase titers were 4 or less in 83 per cent and convalescent titers were 16 or over in 86 per cent of these cases. Only about half of the number of patients having increases in neutralizing antibodies also developed cold agglutinins and agglutinins for the indifferent streptococcus No. 344. Patients from the Eastern United States as well as those from the Pacific Coast were shown to develop virus neutralizing antibodies. Patients with pneumococcal pneumonia and pneumonias caused by influenza virus type A or viruses of the psittacosis group did not have significant increases in neutralizing antibodies for the virus of atypical pneumonia. Cold agglutinins appeared in 3 cases of type A influenzal pneumonia. Sera from persons with atypical pneumonia, when tested against the 3 most prevalent respiratory viruses isolated from cotton rats and hamsters, failed to neutralize these agents or showed no significant change in neutralization titer. PMID- 19871505 TI - MECHANISM OF THE AUGMENTING ACTION OF MINERAL OIL ON ANTIBODY PRODUCTION : TISSUE REACTIONS AND ANTIBODY RESPONSE TO DYSENTERY VACCINE IN SALINE, AND IN SALINE LANOLIN-MINERAL OIL EMULSION. AB - A comparative study was made in rabbits of antibody production and tissue changes following the injection into the foot pads, of saline in Falba and mineral oil emulsion, of killed cells of Shigella paradysenteriae Flexner in saline, and of killed cells of Shigella paradysenteriae in saline in Falba-mineral oil emulsion. It was found that antibody production was greatly prolonged by the emulsification in oil. While with antigen in saline the serum titers began to fall 9 days after injection and disappeared somewhere between the 3rd and 6th months, with antigen in paraffin oil they began to drop only after 14 days, and were still high after 10 months, when the experiment was ended. The toxic effects of the antigen were greatly reduced by the emulsification in oil. A subcutaneous dose of 1.5 mg. of antigen in saline caused mesenchymal reactions in lung, liver, and spleen as well as toxic degeneration and sometimes necrosis of the liver whereas eight times as much of the antigen in oil produced no systemic lesions. Oil drops remained detectable in the foot pad until the end of the experiment. Bacteria remained visible in the oil for 1 week or more, but with saline they disappeared within 1 day. The latter observation shows that retention of antigen at the site of injection is at least one of the mechanisms of prolongation of antibody formation by paraffin oil. The tissue reaction in the foot pad to antigen in oil was largely one of suppuration with the production of persisting mononuclear granulomata whereas after antigen in saline it was chiefly one of catarrhal inflammation, subsiding within a month. The changes in the regional lymph nodes were essentially those of lymphatic hyperplasia with the production of numerous lymphocytes and large active secondary nodules, the macrophages remaining subsidiary. The lymphocytic reaction in the lymph nodes closely paralleled the antibody response but the monocytic reaction at the site of injection was not correlated with this response; in fact, in the antigen in oil experiments the monocytic reaction reached its height after the peak of antibody production. The tissue changes observed in the various experiments were consistent with the finding previously reported from this laboratory, that the lymphocyte is concerned in antibody formation. PMID- 19871506 TI - HEMOGLOBIN PRECIPITATION IN RENAL TUBULES : A STUDY OF ITS CAUSES AND EFFECTS. AB - 1. A readily reproducible pathological lesion closely resembling that typical of the "transfusion kidney" has been obtained by the injection of hemoglobin into rabbits having acid urine, whose renal tubules had previously been damaged to a moderate degree by (a) a short period of complete renal ischemia, or (b) the administration of a specific chemical poison-sodium tartrate. 2. It has been found that hemoglobin is precipitated in the tubules of damaged kidneys excreting either acid or alkaline urine, in contrast to the absence of hemoglobin precipitation in normal kidneys. 3. In the acid state hemoglobin casts are more numerous and more persistent than in the alkaline, and are associated with renal functional disturbances, in contrast to the lack of such disturbances when the urine is alkaline. 4. The ultimate outcome, both anatomically and functionally, in any given instance is determined by variations in the degree of tubular damage, the level of hemoglobinemia, and the urinary pH. PMID- 19871507 TI - THE INFLUENCE OF CHOLINE, CYSTINE, AND OF alpha-TOCOPHEROL UPON THE OCCURRENCE OF CEROID PIGMENT IN DIETARY CIRRHOSIS OF RATS. AB - 1. Five per cent l-cystine in a stock or low protein diet produces ceroid deposits in rat liver. This effect of l-cystine is much greater in low protein than in stock diets. 2. One per cent choline has an inhibiting effect on deposition of liver ceroid resulting from a low protein diet containing excess cystine. 3. The occurrence of ceroid pigment in the livers of rats on a low protein diet, with or without the addition of excess l-cystine, is transiently inhibited by the administration of alpha-tocopherol. Five per cent cod liver oil in the diet did not prevent this effect of alpha-tocopherol. 4. On low protein, vitamin E-deficient diets, there occurs after 4 months, a rapid and progressive weight loss. This does not happen when alpha-tocopherol is added to the diet. PMID- 19871508 TI - STUDIES ON THE BIOCHEMICAL, BIOPHYSICAL, AND IMMUNOGENIC PROPERTIES OF JAPANESE B TYPE ENCEPHALITIS VIRUS AND VACCINES. AB - Studies on the biochemical, biophysical, and immunogenic properties of Japanese B type encephalitis virus and vaccines have been made in order to determine whether a purified vaccine suitable for human use could be obtained by means of differential centrifugation of extracts of infected mouse brains. Studies were also made on extracts of normal mouse brains, it was found that extracts of normal as well as of infected mouse brains contained fairly large amounts of several components of high molecular weight. Components having sedimentation constants near 5 and 40 Svedberg units were found in extracts of infected brains. However the rates of sedimentation of the different components were so similar that it was found impossible, from a practical standpoint, to secure a vaccine consisting largely of virus by means of differential centrifugation. It was also found that a considerable portion of virus was lost or destroyed in the centrifugation process so that it was impossible to secure an effective degree of concentration of immunogenic potency. Although vaccines possessing about twice the immunogenic potency of the starting material were obtained, it was concluded that it was not practical to purify and concentrate Japanese B type encephalitis virus in infected mouse brain extracts by means of differential centrifugation for the production of a vaccine on a large scale. The optimum pH stability range of Japanese B type encephalitis virus activity was found to be near pH 8.5. The virus is inactivated fairly rapidly at pH 7 and very rapidly at more acid reactions. The virus is inactivated rapidly near pH 10. Extracts of infected mouse brains with buffers near pH 8 containing disodium phosphate were found to possess slightly higher titers than saline extracts near pH 7. However vaccines prepared from such extracts were found to possess essentially the same immunogenic potency, hence, although extraction at the more alkaline reaction may perhaps remove more active virus, there was no indication that more immunogenic material was removed at the more alkaline reaction. The use of different diluents in the titration of virus activity and the use of different agents in the preparation and storage of virus suspensions were investigated. It was found that low titers were obtained when Ringer's solution, phosphate buffer at pH 7, or saline-phosphate buffer at pH 8.2 were used as diluents but that high titers were obtained when 10 per cent rabbit serum in saline or in phosphate buffer, 10 per cent skim milk in saline or in phosphate buffer, or 1 per cent arginine at pH 8.3 were used. Undiluted skim milk adjusted to pH 8.4 was found to be as satisfactory as undiluted rabbit serum for the preparation of infected brain suspensions for storage at -70 degrees C. A satisfactory neutralization test was conducted with virus stored in undiluted skim milk at -70 degrees C. and subsequently diluted with 10 per cent skim milk in saline. The demonstration that skim milk can be substituted for rabbit serum in the storage, titration, and neutralization tests of Japanese B type encephalitis virus is of practical importance, for skim milk is more convenient to prepare and more readily available in many localities. PMID- 19871509 TI - PLASMA PROTEIN METABOLISM-ELECTROPHORETIC STUDIES : THE INFLUENCE OF PLASMA LIPIDS ON ELECTROPHORETIC PATTERNS OF HUMAN AND DOG PLASMA. AB - Electrophoretic patterns of human and dog plasma are markedly altered by the extraction of a large part of the plasma lipids. Total electrophoretic areas, relative areas of individual electrophoretic components, and electrophoretic albumin: globulin ratios undergo change. For human plasma, such extractions confirm previous observations that a particularly rich lipid content characterizes beta globulin. Abnormally large beta peaks regularly occur in the presence of elevated plasma lipids. Marked increases in gamma globulin, however, are also found to be due in large part to elevated plasma lipid levels in certain abnormal human plasmas. The greatest relative amount of lipid in dog plasma, in contrast to human plasma, is associated not with the beta globulin, but with components usually designated as alpha globulins. Not only the areas, but the configuration and the number of alpha globulin peaks in dog plasma are altered by the extraction of plasma lipids. The results demonstrate that increased alpha globulin areas which occur in the plasma of hypoproteinemic dogs are due in large part to elevated plasma lipid levels. PMID- 19871510 TI - ENDURING IMMUNITY FOLLOWING VACCINATION OF MICE WITH FORMALIN-INACTIVATED VIRUS OF RUSSIAN SPRING-SUMMER (FAR EASTERN, TICK-BORNE) ENCEPHALITIS : CORRELATION WITH SERUM-NEUTRALIZING AND COMPLEMENT-FIXING ANTIBODIES. AB - A single course of two intraperitoneal injections of formalin-inactivated virus of Russian spring-summer encephalitis induced in albino mice a solidly immune state which endured almost throughout life. Active virus is therefore not essential for the production of a high degree of lasting immunity. The immune response to vaccination consists of resistance to peripherally introduced active virus and development of circulating antibody. A correlation has been found to exist throughout the long period of the immune state between the titer of neutralizing antibody, as determined by the intraperitoneal method described, and the degree of immunity to peripherally introduced active virus. Thus laboratory tests for the immunizing power of a vaccine suggest themselves, to be carried out by an estimation in vaccinated mice of (a) immunity to peripherally inoculated active virus, and (b) serum virus-neutralizing antibody determined by the intraperitoneal method. The roles as indicators of immunity in vaccinated mice of complement-fixing antibody in the serum, of the intracerebral challenge dose of virus, and of the intracerebral method for testing neutralizing antibody are discussed. Finally, if the immune response of man to vaccination with formalin inactivated virus of Russian spring-summer encephalitis follows the pattern of the response of mice as here described, and if the correlation of neutralizing antibody with immunity to peripherally introduced virus applies to man as to mice, then possibly the degree of immunity in human beings following vaccination can be appraised by a peripheral test for neutralizing antibody in the serum. PMID- 19871511 TI - PREVENTION OF PNEUMOCOCCAL PNEUMONIA BY IMMUNIZATION WITH SPECIFIC CAPSULAR POLYSACCHARIDES. AB - 1. Immunization of man with 0.03 to 0.06 mg. of each of the capsular polysaccharides of pneumococcus types I, II, V, and VII, given in a single subcutaneous injection, has been shown to be effective in preventing pneumonia caused by these types but not that due to heterologous types. 2. Immunity appears within a period of 2 weeks following injection of the polysaccharides. Its duration was not determined, although 6 months can be set as a minimum. 3. Immunization of alternate subjects in the population reduced greatly the incidence of pneumonia in the non-immunized. 4. The carrier rate for pneumococcus types I, II, V, and VII was lowered significantly in the immunized group as compared with the controls. It is suggested that an over-all reduction in the incidence of carriers was responsible for the lowered rates for pneumococcal pneumonia in the non-immunized group. PMID- 19871512 TI - THE ETIOLOGY OF COLORADO TICK FEVER. AB - 1. The infectious agent of Colorado tick fever filtered through 181 mmicro membranes caused infection in hamsters and one volunteer. 2. In five out of seven instances, hamsters were infected initially with serum filtered through 24 mmicro membranes or the tick fever appeared on serial transfer. 3. We could not infect two volunteers with 24 mmicro filtrates, though these filtrates did cause infection in hamsters as shown by development of the fever on serial transfer. In one instance, the serum of the hamsters rendered ill in this way was injected into the volunteer who had remained well after inoculation with the original material and it caused Colorado tick fever. 4. Normal hamster serum was passaged through 10 groups of animals and then two human volunteers were injected with it. They did not come down with Colorado tick fever, although both of them were susceptible to the disease as shown by the fact that they fell ill of it on later inoculation with serum from a natural instance of the disease. 5. The infectious agent of Colorado tick fever passes through 24 mmicro membranes. On this basis, it is classified as a virus. PMID- 19871514 TI - STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) : I. THE PRECISION OF MEASUREMENTS IN VIVO OF THE VIRUS AND ANTIBODIES AGAINST IT. AB - This study on pneumonia virus of mice (PVM) was carried out in order to obtain as accurate data as possible on the degree of variation which may be expected in titrations of the virus or of antibodies against it in vivo. It is believed that the knowledge gained will facilitate further investigations on this latent pneumotropic virus and make possible a more exact assessment of the significance of experimental results obtained with the agent. The reproducibility of 50 per cent maximum score titration end points with PVM in mice is such that the chances are 19 out of 20 that a difference of 1.084 log units (i.e. a twelvefold difference) in the end points obtained in two separate titrations is significant. The reproducibility of 50 per cent maximum score serum dilution end points in neutralization tests with PVM in mice is such that the chances are 19 out of 20 that a difference of 0.626 log units (i.e. a fourfold difference) in the end points obtained with two sera against similar amounts of virus is significant. It was found that there is a linear exponential relationship between the serum dilution end point and the quantity of PVM used in a neutralization test. This relationship appears to be identical with immune serum obtained from different animal species, and appears also to be identical to the linear relationship described previously in similar studies with influenza A virus. PMID- 19871513 TI - THE PREPARATION OF HIGHLY PURIFIED PR8 INFLUENZA VIRUS FROM INFECTED MOUSE LUNGS. AB - Highly purified preparations of PR8 influenza virus were obtained from perfused, infected mouse lungs by a combination of methods involving adsorption of the virus on and elution from chicken red cells and differential centrifugation. Such preparations were found to possess 50 per cent infectivity end-points at 10(-11) to 10(-11.8), and 10(-13) to 10(-14.3) gm. of nitrogen in mice and in chick embryos, respectively. A sedimentation constant of 683 S was obtained for the material and electron micrographs revealed essentially spherical particles about 100 mmicro in diameter. The material was isoelectric at pH 5.4 and chemical analyses on several of the preparations indicated the presence of 10.1 per cent of nitrogen, 1.06 per cent of phosphorus, 6.2 per cent of carbohydrate and about 33 per cent of lipid. Positive tests were obtained for both ribonucleic and desoxyribonucleic acids. The virus was precipitated strongly by antisenim to purified PR8 virus obtained from the allantoic fluid of infected chick embryos and this serum inhibited the agglutination of red cells by the mouse virus to a dilution of about 40,000. In general, the properties of the virus isolated from infected mouse lungs were found to coincide with those of the virus obtained from the allantoic fluid of infected chick embryos. PMID- 19871515 TI - STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) : II. IMMUNOLOGICAL EVIDENCE OF LATENT INFECTION WITH THE VIRUS IN NUMEROUS MAMMALIAN SPECIES. AB - The results of neutralization tests with PVM and serum obtained from numerous animal species indicate that antibodies agaiust this virus were present in the blood of all mammalian species tested, as not in that of fowls, and that their incidence in various species was widely different. They indicate, also, that in certain species, particularly the cotton rat, there were marked seasonal variations in the incidence of such antibodies; in the late winter and spring the incidence was much higher than during the summer and fall seasons. Cotton rats and hamsters which did not possess neutralizing antibodies against PVM were susceptible to manifest pulmonary infection with this virus, irrespective of the effects of previous experiments upon them, whereas those which possessed such antibodies were immune. It is suggested that circulating antibodies against PVM were present as a result of preceding infection with a latent virus; either PVM or an agent closely related to it in antigenic composition. Appropriate non specific stimuli, e.g. the intranasal injection of suspensions of normal chick embryos, induced the development of neutralizing antibodies against PVM with significantly greater frequency in each of three species than occurred in control animals. Materials derived from patients with primary atypical pneumonia yielded results almost identical to those obtained with normal chick embryo suspensions. It is suggested that such materials, like the other non-specific stimuli employed, were effective in evoking a specific antibody response, because they unbalanced an equilibrium which previously existed between animal host and latent pneumotropic virus. PMID- 19871516 TI - STUDIES ON THE NATURE OF RESISTANCE OF GRAM-NEGATIVE BACILLI TO PENICILLIN : ANTAGONISTIC AND ENHANCING EFFECTS OF AMINO ACIDS. AB - The susceptibility of E. coli and Salmonella to penicillin is highest in a basal medium devoid of amino acids. Blood serum in certain concentrations, meat infusion broth, yeast extract, and casein hydrolysate interfere with the penicillin activity. The effect is apparently due to the antagonism of certain amino acids in the materials. Dicarboxyl-monoamino acids (i.e. aspartic, glutamic, and hydroxyglutamic acids and asparagine) cystine, arginine, histidine, and hydroxyproline are capable of suppressing the effect of penicilhn upon Gram negative organisms. The antagonism of amino acids is not primarily related to their effect upon the rate of bacterial growth. It is suggested from the experiments detailed, that the antipenicillin activity is due to the effect of the amino acids upon bacterial metabolism. Prepassages in media of various concentrations of antagonistic amino acids alter the resistance of E. coli to penicillin. The changes are in inverse relation to the concentration of the antagonists. The antipenicillin activity of amino acids may be reversed significantly by dl-methionine. The substance, however, reverses only incompletely the antagonism of materials of mixed composition; i.e., casein hydrolysate, meat infusion broth, and serum. Upon addition of methionine, methionine sulfoxide, and threonine, there occurs a marked enhancement of penicillin susceptibility of broth cultures of Brucella, Eberthella, Salmonella, and Shigella. The enhancement is apparently due to the ability of this amino acid mixture to reverse effectively the action of the antagonists present in the cultures. Methionine is essential for the enhancement of penicillin susceptibility. Threonine and methionine sulfoxide facilitate the effect of methionine following a reciprocal quantitative relationship. PMID- 19871517 TI - STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) : III. HEMAGGLUTINATION BY THE VIRUS; THE OCCURRENCE OF COMBINATION BETWEEN THE VIRUS AND A TISSUE SUBSTANCE. AB - 1. The cause for the phenomenon of hemagglutination with heated PVM suspensions has been sought. 2. Evidence in wide variety indicates that the component responsible for hemagglutination is the virus particle itself. 3. The virus is capable of combining with a substance present in lung tissue of certain mammalian host species susceptible to infection by PVM. The occurrence of such combination accounts for a number of unusual properties manifested by this pneumotropic virus. PMID- 19871518 TI - STUDIES ON SCRUB TYPHUS : I. SOLUBLE ANTIGEN IN TISSUES AND BODY FLUIDS OF INFECTED MICE AND RATS. AB - A complement-fixing antigen specific for scrub typhus occurs in the body fluids and tissues of infected mice, white rats, and cotton rats. The specific serological substance is demonstrable only in those animals which develop a rapidly fatal disease after an incubation period of a few days. Such an experimental infection is induced in mice and rats by the intravenous injection of suspensions of yolk sac rich in R. orientalis. Ether extraction is an important step in the preparation of a complement-fixing antigen from tissues of mice dying with scrub typhus. The Imphal No. 8 and Calcutta strains of R. orientalis are indistinguishable on the basis of complement fixation and cross immunity tests. The complement-fixing antigen in body fluids of infected mice and rats and in our preparations of tissues from such animals occurs as a soluble antigen. Under the proper conditions the soluble antigen can be stored or dehydrated without loss of serological activity. PMID- 19871519 TI - FORMATION OF SEROLOGICALLY REACTIVE DEXTRANS BY STREPTOCOCCI FROM SUBACUTE BACTERIAL ENDOCARDITIS. AB - Serologically reactive dextrans were synthesized from sucrose by 22 of 48 strains of streptococci isolated from the blood of patients with subacute bacterial endocarditis. One strain formed an appreciable amount of levan as well as dextran. Nine strains of group H streptococci from throats formed dextran serologically similar to that formed by the described endocarditis streptococci. Six strains of S. salivarius from throats and feces, which were included for comparison, formed levan which agreed in serological properties with the purified levan previously described for one strain of that species. The experimental method comprised a series of serological tests that were controlled and supplemented by physical and chemical tests, and furnished a relatively simple but entirely adequate way of recognizing and distinguishing dextrans and levans in bacterial cultures without isolation of the purified polysaccharides. The possible use of dextran and levan formation in the differential description of non-hemolytic streptococci is suggested. PMID- 19871520 TI - STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES : II. EFFECT OF DESOXYRIBONUCLEASE ON THE BIOLOGICAL ACTIVITY OF THE TRANSFORMING SUBSTANCE. AB - It has been shown that extremely minute amounts of purified preparations of desoxyribonuclease are capable of bringing about the complete and irreversible inactivation of the transforming substance of Pneumococcus Type III. The significance of the effect of the enzyme, and its bearing on the chemical nature of the transforming substance, together with certain considerations concerning the biological specificity of desoxyribonucleic acids in general, are discussed. PMID- 19871521 TI - STUDIES ON THE CHEMICAL NATURE OF THE SUBSTANCE INDUCING TRANSFORMATION OF PNEUMOCOCCAL TYPES : III. AN IMPROVED METHOD FOR THE ISOLATION OF THE TRANSFORMING SUBSTANCE AND ITS APPLICATION TO PNEUMOCOCCUS TYPES II, III, AND VI. AB - 1. An improved method is outlined for the isolation and purification of the pneumococcal transforming substance. This method makes use of the fact that citrate inhibits the destructive action of the enzyme, desoxyribonuclease, which is released together with the active material during lysis of the living bacterial cells. A fivefold greater yield of purified transforming agent is obtained by the present method than by the procedure previousiy described. 2. The specific transforming substance has been isolated from pneumococci of types II and VI, in addition to Type III. In each instance the biologically active material has been found to consist of desoxyribonucleic acid. PMID- 19871522 TI - WESTERN EQUINE ENCEPHALOMYELITIS VIRUS IN THE BLOOD OF EXPERIMENTALLY INOCULATED CHICKENS. AB - 1. Chickens inoculated subcutaneously with 0.2 cc. of a 10(-2) to 10(-7) dilution of Western equine mouse brain virus had the virus in the blood serum between the 12th and the 48th hour in most instances. The fowls showed no signs of illness. 2. Viremia could be induced regularly in chickens by inoculating subcutaneously the least amount of virus which would produce encephalitis in the mouse when inoculated by the intracerebral route. 3. Even the minimal infecting dose for a chicken led to such multiplication of the virus that it was detectable in the serum in a 10(-4) dilution. Moreover, a minimal infecting dose appeared to result in a longer period of viremia than was produced by a larger dose. 4. Virus has not been found to persist for more than 3 days after inoculation in any organ of the chicken tested for it and usually it did not persist over 2 days. Antibodies were present in the blood within at least 15 days after inoculation. 5. It is concluded that chickens may serve as sources of infection for mosquitoes or other blood-sucking ectoparasites for short periods of time after the infecting bite of a similar invertebrate vector. There is no evidence that the chicken serves as a latent carrier of the virus. 6. No virus could be found in the blood of 2 inoculated calves, and virus has not been demonstrated regularly or with the same case in the blood of horses or of men, as it has in that of chickens. It seems unlikely therefore that large mammals serve frequently as sources for mosquito infection. 7. These experimental data on fowls and mammals correlate well with other epidemiological and laboratory findings, in particular with the feeding preference of the mosquitoes found infected in epidemic areas. PMID- 19871523 TI - ST. LOUIS ENCEPHALITIS VIRUS IN THE BLOOD OF EXPERIMENTALLY INOCULATED FOWLS AND MAMMALS. AB - 1. Of three species of mammals tested by peripheral inoculation (guinea pig, cat, and horse) none showed viremia under conditions which suggested that any of these species would serve as a frequent source of mosquito infection. 2. Of the birds tested (chicken, duck, and dove) all developed viremia and might readily serve as natural sources of mosquito infection. Chickens were shown to be very highly susceptible to infection by minute amounts of virus inoculated subcutaneously. 3. Virus may appear in the blood of chickens within 16 hours after inoculation and it has persisted till at least the 120th hour. No fowl showed any sign of illness as a result of the infection. PMID- 19871524 TI - LABORATORY TRANSMISSION OF JAPANESE B ENCEPHALITIS VIRUS BY SEVEN SPECIES (THREE GENERA) OF NORTH AMERICAN MOSQUITOES. AB - In the present studies ten common species of Western North American mosquitoes have been tested for their ability to act as vectors of Japanese B encephalitis virus (see summary Table XII). The strain of Japanese B encephalitis virus which was used was adapted to direct mouse brain passage, probably a disadvantage, but no freshly isolated strain was available. Of the ten species of mosquitoes tested, seven were demonstrated to be laboratory vectors. These seven species represent three genera (Culex, Aedes, and Culiseta). In previously reported work Japanese and Russians had only incriminated five species of two genera (Aedes and Culex) (1-3). Transmission was made to mice 21 times and to a chicken once. Two attempts to infect mosquitoes from an infected chicken were unsuccessfui, but no significance is attached to so few experiments. Repeated tests for virus in the eggs, or in imagines reared from eggs of infected female mosquitoes have been negative. In this we failed to confirm results claimed by Japanese investigators (5, 6). These data, in addition to the published accounts by Japanese and Russian workers of the natural epidemiology of this disease lead us to believe that this virus might well establish itself in North America, especially if introduced in those areas where our native encephalitides are now endemic. These studies also indicate that species of mosquitoes (Culex tarsalis, Culex pipiens, See PDF for Structure Aedes dorsalis, and Culiseta inornata) now known to be fully incriminated vectors of the Western equine or St. Louis encephalitis viruses can also serve as laboratory vectors of the Japanese B virus. Methods for the effective abatement of these species should be further developed and put into practice if future epidemics of encephalitis of the Western equine, St. Louis, or Japanese B types in Western North America are to be prevented or brought under control. PMID- 19871525 TI - INTERFERENCE BETWEEN VIRUSES IN TISSUE CULTURE. AB - The influence of one virus on the growth of another in tissue culture was investigated. The 17DD High strain of yellow fever virus was found capable of completely suppressing the growth of both the Asibi strain of the same virus and of the heterologous West Nile virus, even when these were added to the cultures in large amounts. The 17DD High strain of yellow fever virus and the West Nile virus produced either partial or complete suppression of growth of the Venezuelan equine encephalomyelitis virus, depending upon the quantity of the latter inoculated into the cultures. Owing to lack of methods for the detection of interference except in a single direction, reciprocal interference with these viruses could not be investigated. The 17DD High strain of yellow fever virus and the West Nile virus were able to suppress completely, or almost completely, the growth of influenza A virus added to the infected cultures in maximal amounts. Interference in the reverse direction, even with the use of small amounts of the neurotropic viruses, was not demonstrable. Cultures infected with the 17DD High strain of yellow fever virus were examined for the presence of neutralizing antibodies and non-specific antiviral substances; neither was found present. PMID- 19871526 TI - EFFECT OF PHOTO-OXIDATION ON ISOHEMAGGLUTINATING ANTIBODIES. AB - Photo-oxidation (in the presence of eosin Y as a sensitizer) of isohemagglutinating sera destroyed their agglutinating activity gradually, but did not seem to convert any of the agglutinins studied into inhibiting ("incomplete" or "blocking") antibody. PMID- 19871527 TI - SUPPRESSION OF GROWTH OF BROWN-PEARCE TUMOR CELLS BY A SPECIFIC ANTIBODY : WITH A CONSIDERATION OF THE NATURE OF THE REACTING CELL CONSTITUENT. AB - Experiments are reported in detail which show that an antibody which appears in the blood of certain rabbits implanted with the Brown-Pearce tumor or injected with cell-free extracts of it is capable of suppressing the growth of the tumor cells under a variety of experimental conditions, the effects of the antibody being wholly distinct from those of unknown factors that frequently bring about regression of the growth. The implications of the findings are discussed with particular reference to facts indicating that the distinctive cell constituent with which the antibody reacts may play a significant part in the proliferative activities of the Brown-Pearce tumor cell. PMID- 19871528 TI - PERIOD OF INFECTIVITY OF PATIENTS WITH EXPERIMENTALLY INDUCED INFECTIOUS HEPATITIS. AB - 1. Serum and stools obtained in the pre-icteric phase of one patient, and pooled specimens of the same materials from 5 patients with experimentally induced (by feeding) infectious hepatitis produced the disease in 10 out of 15 human volunteers following feeding or parenteral inoculation. 2. Pooled specimens of urine and nasopharyngeal washings from 5 patients, obtained in the acute phase of infectious hepatitis when virus was proven to be in the stool and serum, were not demonstrably infectious when fed and given intranasally to 6 volunteers. 3. Serum obtained in the midincubation period of one patient with experimentally induced infectious hepatitis failed to produce apparent infection when inoculated parenterally into 3 human volunteers. This is in contrast to the situation in homologous serum jaundice in which "virus" has been demonstrated in the sera of volunteers during the incubation period. 4. Serum and stools obtained from one patient and pooled specimens of stools from 5 patients 25 to 31 days after onset of experimental infectious hepatitis failed to produce apparent infection in 10 human volunteers. 5. No appreciable difference was detected in length of incubation period following the parenteral administration of widely different amounts of the same strain of "virus." PMID- 19871529 TI - STUDIES ON THE COMPLEMENT FIXATION ANTIGENS OF INFLUENZA VIRUSES TYPES A AND B. AB - Two types of specific particles can be obtained from allantoic fluid preparations of influenza A and B virus. The larger particle which possesses all the attributes of the virus and which shows a sedimentation constant of about 600 S was compared with the smaller component (30 S) by complement fixation technic. The 30 S component can be differentiated from the 600 S particle by the patterns of the optimal antigen-antibody relationships and by cross-absorption of the sera with the two particles. Some of the 30 S-type antigen can be demonstrated in higher concentrations of the 600 S particles by the use of sera containing only anti-30 S; i.e., sera carefully absorbed with 600 S component. Also, upon sonic vibration of the 600 S particle, serologically active material was released which behaved in every respect like the 30 S antigen. The response of human beings to these antigens was found to vary. Antibodies to the 30 S component developed in the majority of subjects exposed to active virus either under epidemic or experimental conditions, but only rarely following vaccination with three different vaccines. In selecting sera without 30 S antibodies a fairly close correlation between the antibody titers obtained by inhibition of hemagglutination and complement fixation with the 600 S component was obtained. The presence of 30 S antibodies prevented such a correlation. The reaction with the 30 S antigen may be of value in the diagnosis and study of the epidemiology of influenza. PMID- 19871530 TI - PRECIPITIN REACTIONS OF HIGHLY PURIFIED INFLUENZA VIRUSES AND RELATED MATERIALS. AB - Antisera to purified PR8 virus, to purified protein from normal allantoic fluid, and to purified normal mouse lung particles were obtained from hyper-immunized rabbits and used in quantitative precipitin tests employing various purified preparations of influenza virus and related materials as antigens. The results of those tests indicated that the most highly purified preparations of PR8 or of Lee influenza virus obtained from infectious allantoic fluid contain an antigen characteristic of normal allantoic fluid and likewise that highly purified mouse lung PR8 virus contains an antigen characteristic of normal mouse lungs. Since the infectivity of virus preparations which were ultracentrifugally and electrochemically homogeneous was precipitated by the appropriate antisera to normal antigens, it was concluded that the normal antigens constitute a part of the 100 mmicro particles with which influenza virus activity is at present deemed to be associated. It was estimated from quantitative precipitin data that the most highly purified preparations of PR8 and of Lee influenza viruses obtained from infectious allantoic fluid contain at least about 20 and 30 per cent, respectively, of an antigenic structure characteristic of the sedimentable protein of normal allantoic fluid. PMID- 19871531 TI - COLORADO TICK FEVER AND DENGUE : AN EXPERIMENTAL IMMUNOLOGICAL AND CLINICAL COMPARISON. AB - Six human beings were inoculated with dengue and developed typical disease. Two of these were reinoculated and proved immune. The remaining four were later inoculated with Colorado tick fever. Three developed typical disease. The fourth, who remained well, has previously lived in an endemic area (Colorado). One patient was inoculated with Colorado tick fever first and later with dengue. He developed both diseases. Colorado tick fever and dengue do not give a cross immunity. Hamsters can be infected with Colorado tick fever but not with dengue. Colorado tick fever and dengue appear to be distinct disease entities. PMID- 19871532 TI - ANTIBODY FORMATION IN VOLUNTEERS FOLLOWING INJECTION OF PNEUMOCOCCI OR THEIR TYPE SPECIFIC POLYSACCHARIDES. AB - 1. A modification of the microanalytical quantitative precipitin method, five to ten times as sensitive as the older procedure, has been used to measure the type specific antibody response in human beings. Injections of type-specific pneumococci or equivalent amounts of their type-specific polysaccharides led to comparable antibody production. In general, the few hundredths of a milligram of polysaccharides injected functioned as extraordinarily powerful antigens. 2. Subcutaneous injections of the polysaccharides were as effective as intracutaneous, and the resulting antibody levels, which were highly variable individually, remained relatively constant for 5 to 8 months, gradually tapering off during periods of observation that exceeded 2 years in some instances. 3. After the injection of several type-specific polysaccharides widely diverse combinations of selective and non-selective responses were observed. 4. Booster doses had little or no effect in increasing circulating antibody, even after 2 years. A tentative explanation is given of this unexpected result. 5. Possibly because they frequently harbor pneumococci, normal human beings appear to be in serological equilibrium with the C-antigen of pneumococcus, since in most instances the quite appreciable anti-C content of their sera remained relatively constant during periods of a year or longer. Many of the sera also contained antibody to S VII. PMID- 19871533 TI - MOUSE-PROTECTIVE TITERS OF SERA OF VOLUNTEERS FOLLOWING INJECTION OF PNEUMOCOCCI OR THEIR TYPE-SPECIFIC POLYSACCHARIDES. AB - 1. Sera of human subjects immunized with pneumococci or their type-specific polysaccharides showed type-specific antibody by mouse protection tests as well as on determinations of the specifically precipitable nitrogen. 2. The ratio, mouse-protective units to antibody nitrogen, was less in human sera of low potency than in more potent human or animal sera. PMID- 19871534 TI - A NEUROPATHOLOGICAL STUDY OF ACUTE HUMAN POLIO-MYELITIS WITH SPECIAL REFERENCE TO THE INITIAL LESION AND TO VARIOUS POTENTIAL PORTALS OF ENTRY. AB - The peripheral and central nervous tissues of eight patients dying of acute poliomyelitis were examined histologically to discover whether and to what extent the distribution of lesions was consistent with the hypothesis that virus enters the mucous membranes through the superficial nerve fibers, infects the neurons in peripheral ganglia, and proceeds thence into the central nervous system to infect connecting centers. Evidence consistent with this hypothesis was found in all cases. Based on concurrent lesions in the primary and secondary centers, the frequency of involvement of the various systems and the probability of their having acted as primary pathways for entering infection may be summarized as follows:- (a) Trigeminal afferent system (V cranial): very frequent. (b) Visceral afferent system (IX and X cranial): fairly common but less than V. (c) Gustatory system (VII, IX, and X cranial): occasional. (d) Sympathetic system, upper levels (pharynx, bronchial tree, upper esophagus): occasional. (e) Sympathetic system, lower (intestine): occasional or doubtful. (f) Vagal efferent (parasympathetic) system (X cranial) and olfactory (I cranial) system: uninvolved. In general, the evidence of penetration through the upper alimentary and respiratory tracts was more conspicuous and consistent than through the lower alimentary tract. The pharynx appears to be an especially favorable site for the primary penetration of virus into the body. Our data suggest that the primary lesion of poliomyelitis occurs in the peripheral ganglia. Primary invasion through the sympathetics results in initial involvement of the central nervous system at the spinal level; invasion through all the other channels described results in initial involvement of the central nervous system at the level of the brainstem (midbrain, pons, medulla). In neither instance does the level of initial involvement necessarily determine the site of initial paralysis. PMID- 19871535 TI - PLASMA SUBSTITUTES : HUMAN AND ANIMAL GLOBIN RELATED TO THE PRODUCTION OF HEMOGLOBIN AND PLASMA PROTEIN DOG HEMOGLOBIN UTILIZATION IMPROVED BY METHIONINE BUT NOT BY ISOLEUCINE. AB - Hemoglobin and globin alone, supplemented, or modified in various ways are seriously considered as plasma substitutes. Human globin given to doubly depleted (anemic and hypoproteinemic) dogs by vein contributes to the production of new hemoglobin and plasma protein, but there is some toxicity and weight loss. Dog hemoglobin given intraperitoneally is better tolerated and somewhat more completely utilized with more blood proteins formed and less weight loss. Dog globin (tryptic digest) given by vein in anemic dogs is associated with a moderate production of new hemoglobin. Horse globin by mouth contributes to the formation of new hemoglobin in the standard anemic dog. Dog hemoglobin given intraperitoneally in protein fasting, non-anemic dogs is well utilized to maintain nitrogen and weight balance. A dl-isoleucine supplement fails to improve this utilization of hemoglobin for maintenance in the dog. A small supplement of dl-methionine greatly improves the utilization of dog hemoglobin for maintenance in the dog and further addition of isoleucine is without effect. The intermediary metabolism of dog hemoglobin is not yet worked out. Electrophoretic analyses (Table 6) suggest that globin appears in the peripheral circulation after intraperitoneal injections of hemoglobin. PMID- 19871536 TI - THE ABSENCE OF ANTIBODY IN THE MACROPHAGES DURING MAXIMUM ANTIBODY FORMATION. AB - Following the injection of dysentery antigen in saline or in saline-in-paraffin oil emulsion into the pad of the rabbit's hind foot, considerable quantities of antibody were recovered from the popliteal lymph node, while the tissue at the site of injection, containing many granulocytes and numerous macrophages, revealed only insignificant quantities of antibody. Following the injection of various dysentery and typhoid antigen combinations into the abdominal cavity, no antibody was found in the isolated granulocytes and macrophages of the peritoneal exudate, while the supernatant fluid revealed titers that roughly paralleled those of the blood serum. Similar results were obtained when animals were injected first with antibody intravenously, and subsequently with an unspecific irritant intraperitoneally. The presence of antibody in the supernatant fluid was, therefore, interpreted as being due to secondary concentration (fixation) in an inflamed area. These findings together with the previously described observations on the lymphocyte seem to show that the macrophage does not synthesize agglutinins against dysentery or typhoid bacilli. PMID- 19871537 TI - THE ACTIVATION OF SKIN GRAFTS. AB - Rabbit skin rendered hyperplastic by various agents showed less tendency than normal skin to contract when sliced off, and when used for grafts it united with the bed more rapidly and was vascularized sooner. The stimulated epidermis proliferated practically at once, and abundantly, to cover adjacent raw surfaces. Also the donor area healed much more swiftly than usual and became infected less often. Certain grave limitations and hazards encountered during the experiments with hyperplastic grafts are considered. PMID- 19871538 TI - THE EFFECT OF HIGH PRESSURES ON HEMAGGLUTINATING ANTIBODIES. AB - It was found that exposure of hemagglutinating sera to pressures of the order of 3,000 to 4,000 atmospheres destroyed their agglutinating power, but did not convert them to inhibiting ("blocking") antibodies. Higher pressures (4,500 to 5,500 atmospheres) were required to destroy inhibiting anti-Rh(0) antibodies in a "blocking" serum. This conforms with ideas already held that the "blocking" antibodies are significantly more stable than the agglutinating antibodies. PMID- 19871539 TI - FACTORS AFFECTING THE GROWTH OF TUBERCLE BACILLI IN LIQUID MEDIA. AB - 1. Certain water-soluble esters of long chain fatty acids (in particular of oleic acid) favor submerged and diffuse growth of mycobacteria throughout the depth of synthetic liquid media. 2. Esters of oleic acid increase considerably the amount of growth yielded by avian strains in synthetic media. 3. The addition of serum albumin to synthetic liquid media permits visible growth of minimal inocula of virulent human tubercle bacilli (10(-8) mg.) within 11 to 15 days. 4. Cultures growing diffusely in media containing the water-soluble esters- with or without albumin-consist of cells of classical morphology and staining properties, which again exhibit the usual mode of growth when returned to the standard synthetic or egg yolk media. PMID- 19871540 TI - THE SITE OF ANGIOTONIN DESTRUCTION. AB - 1. Theoretical considerations render it unlikely that the greatest part of the angiotonase found in the organism is available for the destruction of angiotonia. A priori considerations support the view that only plasma angiotonase is involved in angiotonin destruction in vivo. 2. We have utilized the magnitude and duration of the presser response to angiotonin as an index of available angiotonase, and we have found that: (a) Nephrectomy and evisceration are without marked effect on angiotonin response. (b) Hemorrhage and hemodilution without shock cause a striking increase in the response to angiotonin and this appears to be due to removal of the plasma rather than the cells. Shock developing after hemorrhage results in a state of refractoriness to angiotonin. (c) Intact red cells in vitro have no destructive action on angiotonin, but after hemolysis they have several hundred times the activity of plasma, (d) Intravascular hemolysis, whether produced in vitro or in vivo, decreases the response to angiotonin to a degree which is consistent with the hypothesis that the normal animal destroys angiotonin entirely in its plasma. The active principle in hemolyzed blood is destroyed by heating to 65-70 degrees C. for 15 minutes. 3. These findings support the hypothesis that all or at least the greatest part of angiotonin destruction under physiological circumstances occurs in the plasma, and the significance of this hypothesis is discussed. PMID- 19871541 TI - PERIOD OF INFECTIVITY OF PATIENTS WITH HOMOLOGOUS SERUM JAUNDICE AND ROUTES OF INFECTION IN THIS DISEASE. AB - 1. Pooled specimens of serum obtained from 3 human volunteers three-fourths through their respective 56, 66, and 70 day incubation periods of homologous serum jaundice produced the disease in 1 out of 4 human volunteers following parenteral inoculation. 2. Serum specimens obtained from these same 3 patients during the acute, pre-icteric phase of their homologous serum jaundice produced the disease in 3 out of 4 human volunteers following parenteral inoculation. 3. These same sera, proven to be infectious by parenteral inoculation, failed to produce disease when ingested by 10 other human volunteers. 4. Pooled specimens of serum obtained in the convalescent phase (28 to 32 days after onset) of these 3 patients failed to produce apparent infection when inoculated parenterally into 5 human volunteers. 5. Pooled specimens of feces of 3 patients obtained in the acute phase of homologous serum jaundice, when virus was proven to be in the serum, were not demonstrably infectious when fed to 6 volunteers. 6. These findings are slightly different from those encountered in a similar study with infectious material from cases of infectious hepatitis. PMID- 19871542 TI - INFLUENCE OF DIETARY FACTORS AND SEX ON THE TOXICITY OF CARBON TETRACHLORIDE IN RATS. AB - Six groups of rats on different diets were exposed to the inhalation of carbon tetrachloride (about 300 p. p. m.) for 150 days. Food intake and changes in weight were followed throughout the experiment. Animals fed a diet low in protein showed greater susceptibility than rats on a diet high in protein. Methionine was a good substitute for protein (casein) in the diet. Increase in fat intake with correspondingly lower carbohydrate intake exerted a harmful effect, especially evident in combination with a low protein diet. In this change of the fat: carbohydrate ratio, whether the increased fat or the lowered carbohydrate is the specific factor must remain unanswered at the present time. Necrotizing nephrosis was the presenting sign of the intoxication caused by carbon tetrachloride, in addition to hepatic changes, such as hydropic degeneration, necrosis, and cirrhosis. Dietary factors (methionine and methionine-containing protein, as well as low fat intake) more consistently prevented renal injury than cirrhosis of the liver. Under identical dietary conditions, especially with higher fat intake, male rats appeared to evince greater susceptibility to carbon tetrachloride than female rats. The significance of this observation and its wider applicability has been discussed. PMID- 19871543 TI - HEMOGLOBIN AND PLASMA PROTEIN PRODUCTION : VARIOUS PROTEINS, CONCENTRATES, AND DIGESTS INFLUENCE BLOOD PROTEIN PRODUCTION IN ANEMIA AND HYPOPROTEINEMIA. AB - Given healthy dogs, fed abundant iron and protein-free or low protein diets, with sustained anemia and hypoproteinemia due to bleeding, we can study the capacity of these animals to produce simultaneousiy new hemoglobin and plasma protein. The reserve stores of blood protein-producing materials in this way are largely depleted, and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for considerable periods of time. These dogs are very susceptible to infection and to injury by many poisons. Dogs tire of these diets and loss of appetite terminates many experiments. These incomplete experiments are not recorded in the present paper but give supporting evidence in harmony with those tabulated. Under these conditions (double depletion) the dogs use effectively the proteins listed above-egg, lactalbumin, meat, beef plasma, and digests of various food proteins and hemoglobin. Egg protein at times seems to favor slightly the production of plasma protein when compared with the average response (Tables 1 and 2). Various digests and concentrates compare favorably with good food proteins in the production of new hemoglobin and plasma protein in these doubly depleted dogs. Whole beef plasma by mouth is well utilized and the production of new hemoglobin is, if anything, above the average-certainly plasma protein production is not especially favored. "Modified" beef plasma by vein causes fatal anaphylaxis (Table 4). Hemoglobin digests are well used by mouth to form both hemoglobin and plasma protein. Supplementation by amino acids is recorded. Methionine in one experiment may have been responsible for a better protein output and digest utilization (Table 7). PMID- 19871544 TI - IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : II. PROPERTIES OF THE BLOOD GROUP A SUBSTANCE FROM POOLS OF HOO STOMACHS AND OF SPECIFIC PRECIPITATES COMPOSED OF "A" SUBSTANCE AND HOMOLOGOUS HUMAN ANTIBODY. AB - 1. The microquantitative precipitin method can be used to compare the relative activity of different preparations of the blood group A substance from hog stomachs and to study the effect of chemical treatment upon its stability. 2. With samples of about 25 microg. antibody nitrogen, an error of +/-1.7 microg. antibody nitrogen will result in an error of +/-12 per cent in the estimation of the amount of A substance. 3. The blood group A substance showed no significant loss of activity at 37 degrees C. after 48 hours at pH 1.07 to 10.7 or after 2 hours at 100 degrees C. over a pH range from 2.97 to 7.58. Exposure at 100 degrees C. at pH 1.03 or at 9.03 or higher resulted in loss of activity. Parallel results were obtained by the hemagglutination inhibition and quantitative precipitin methods. 4. The solubility of specific precipitates of the blood group A substance from hog stomach and its homologous antibody formed in man was found to be about 1.6 microg. antibody N/ml. 5. A comparison is given of the chemical properties and activity of blood group A substances obtained by several procedures from pools of hog stomachs. PMID- 19871545 TI - IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : III. PROPERTIES OF PURIFIED BLOOD GROUP A SUBSTANCES FROM INDIVIDUAL HOG STOMACH LININGS. AB - 1. Studies on a number of individual hog stomachs have shown that substances with blood group A activity cannot be obtained from all hogs. Of ten stomachs studied, only seven yielded products with blood group A activity. All ten purified preparations, however, showed identical properties with respect to nitrogen, reducing sugar, glucosamine, acetyl, and relative viscosity. Six of the seven active samples were of equal potency in precipitating anti-A; the seventh was slightly less active. 2. Preparations from random pools of hog stomachs, although possessing the same analytical properties, were of lower activity than those from individual active stomachs as determined by the microquantitative precipitin method. 3. An immunochemical method for estimating the absolute purity of the blood group A substance by determining the proportion of its glucosamine precipitated by excess anti-A was developed. Values of about 84 per cent for the purity of six of the seven purified active preparations from the individual hog stomachs were obtained. 4. The inactive products, unlike the active ones, did not stimulate the production of anti-A on injection into human beings and did not precipitate anti-A or inhibit hemagglutination of A erythrocytes by anti-A. PMID- 19871546 TI - THE PREPARATION OF SECTIONS OF GUINEA PIG LIVER FOR ELECTRON MICROSCOPY. AB - 1. A method is described whereby sections of guinea pig liver cells can be prepared for electron microscopy after fixation. 2. The high resolving powerof the electron microscope reveals the presence of two components, one particulate, the other apparently of fibrous texture, in the ground substance of the cells. PMID- 19871547 TI - SULFONAMIDE CHEMOTHERAPY OF COMBINED INFECTION WITH INFLUENZA VIRUS AND BACTERIA. AB - 1. Sulfonamide chemotherapy controls the bacterial component of combined infection with influenza virus and pneumococci in rats. 2. Reinstillation of fluid (broth, physiological salt solution) into the respiratory passages of mice several days after sublethal viral infection converts the viral infection into a lethal one. 3. Sulfonamide chemotherapy controls the bacterial component of combined bacterial and viral infection of mice, produced by intrabronchial inoculation of mixtures of bacteria and sublethal or lethal doses of virus. 4. Bacterial pneumonia may be superimposed upon sublethal viral infection in mice by inhalation of fine droplets of bacterial suspension several days after inoculation of virus. Normal mice inhaling fine droplets of bacterial suspension fail to develop obvious disease. 5. Sulfonamide chemotheiapy controls bacterial pneumonia superimposed on sublethal viral infection by inhalation of fine droplets of bacterial culture. 6. The secondary bacterial penumonia does not convert the sublethal viral infection into a lethal one. 7. If another pandemic of influenza occurs, it is probable that sulfonamide chemotherapy will be valuable in the treatment of secondary bacterial pneumonia and will be effective in lowering the case fatality rate if the viral component of the infection is not severe enough by itself to cause death. PMID- 19871548 TI - ST. LOUIS ENCEPHALITIS : INFECTION OF CHICKEN MITES, DERMANYSSUS GALLINAE, BY FEEDING ON CHICKENS WITH VIREMIA; TRANSOVARIAN PASSAGE OF VIRUS INTO THE SECOND GENERATION. AB - A colony of chicken mites (Dermanyssus gallinae) was established from a single adult female mite and her offspring. This colony of mites was shown to be free of the virus of St. Louis encephalitis. Infection of mites from this homogeneous colony with the virus of St. Louis encephalitis was accomplished by feeding on chickens having viremia. The virus was recovered as readily from mites which had not been allowed to feed for 8 days as from mites freshly engorged, showing that the demonstration of virus in the mites does not depend on the presence of fresh infective chicken blood. Transovarian passage of the St. Louis virus into the second generation has been demonstrated in mites infected experimentally. The female mite infected as an adult can pass the St. Louis virus through eggs laid after additional feeding on normal blood. Persistence of the virus for a period of 6 months has been shown in a colony of mites infected experimentally in the laboratory. PMID- 19871549 TI - LOCALIZATION OF RIBONUCLEIC ACID IN THE CYTOPLASM OF LIVER CELLS. AB - The attempt has been made to determine the character of the basophile material that occurs normally in the cytoplasm of liver cells and accumulates in association with the hyperplasia of liver cells and of newly formed bile ducts when the azo dye butter yellow is administered to white rats. This substance in the normal liver cells, in the parenchymatous foci of basophile hyperplasia that are precursors of hepatomas, and in the hyperplastic basophile ducts that precede the cholangiomas produced by butter yellow has the characteristics of ribonucleic acid. It absorbs ultraviolet radiation of wave length 2537 A. It does not, like desoxyribonucleic acid, give the Feulgen reaction. It is removed from the cytoplasm by ribonuclease, and precipitation with lanthanum acetate protects it against the enzyme. PMID- 19871550 TI - STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT : II. THE NATURE OF THE CAUSAL AGENT IN EXPERIMENTALLY INFECTED MICE. AB - Coccobacilliform bodies, pleuropneumonia-like organisms, or other cultivable pathogenic bacteria were not demonstrable in lung and exudate suspensions from selected adult rats naturally infected with endemic pneumonia or from experimentally infected mice. The specific factor in lung suspensions from mice was identified with an agent which was active on dilution through 10(7). It failed to pass through Berkefeld N filters but was generally present in V filtrates, with a loss in titer up to 1000-fold. It was largely removed from suspension on centrifugation at a speed of 9000 R.P.M. for 30 minutes. Attempts to cultivate the agent in embryonated eggs were uniformly unsuccessful. In fluid suspension it failed to withstand storage at 40 degrees C. for a week but remained viable for at least 3 months in a frozen state under dry ice. The relation of the infective agent to viruses and to pleuropneumonia-like organisms is discussed. PMID- 19871551 TI - INFLUENCE OF EXPERIMENTAL KIDNEY DAMAGE ON HISTOCHEMICALLY DEMONSTRABLE LIPASE ACTIVITY IN THE RAT. COMPARISON WITH ALKALINE PHOSPHATASE ACTIVITY. AB - Lipase activity was found in the cytoplasm of the proximal convoluted tubules in tissue sections of rat, rabbit, dog, mouse, hamster, and guinea pig, stained according to Gomori's method. Uranium and mercury poisoning do not inactivate the enzyme in necrotic cells of the proximal convoluted tubules. Its activity diminished in the atrophic and regenerating cells of the kidneys of rats, surviving the acute phase of the intoxication. In the acute stage of choline deficiency marked reduction in enzymatic activity was seen in the necrotic tubules, and in the atrophied and regenerating tubules in the subacute stage. Lipase activity was markedly diminished in hydronephrotic kidneys 10 to 12 days after ligation of the ureter. In sections stained for alkaline phosphatase activity nearly identical alterations were found. Experimental damage influences both histochemically demonstrable enzymes in a similar manner. PMID- 19871552 TI - A RICKETTSIAL INFECTION IN CANADIAN VOLES. AB - From apparently normal voles captured on Grosse Isle, Province of Quebec, Canada, an infective agent has been grown in embryonated eggs, and by inoculation an inapparent infection was established in voles, mice, guinea pigs, hamsters, and rats. No growth of the agent was obtained in the absence of living cells, and the manner of its development in the yolk sac of embryonated eggs, as well as morphological, epidemiological, and pathogenic features, indicates a rickettsial nature. The inability to transmit infection by either cage or intrauterine contact points to a vector, and mites are shown to have a probable part in the epidemiology. Mice infected with the vole agent resist lethal doses of the Karp strain of scrub typhus, and certain epidemiological, morphological, and immunological features support the relationship indicated by the mouse tests. It is therefore concluded that voles on this island have an inapparent infection due to a rickettsia that may be related to the rickettsia of scrub typhus. PMID- 19871553 TI - FRACTIONATION OF MAMMALIAN LIVER CELLS BY DIFFERENTIAL CENTRIFUGATION : I. PROBLEMS, METHODS, AND PREPARATION OF EXTRACT. AB - 1. Materials and technical procedures involved in the preparation of liver suspensions have been described and discussed. 2. Liver extracts prepared by the present method appear to contain almost exclusively elements of cytoplasmic origin and can be considered to represent, on a large scale, the cytoplasm of liver cells. PMID- 19871554 TI - FRACTIONATION OF MAMMALIAN LIVER CELLS BY DIFFERENTIAL CENTRIFUGATION : II. EXPERIMENTAL PROCEDURES AND RESULTS. AB - 1. A method is described whereby the major components of liver suspensions are segregated according to size into three main fractions: (a) a large granule fraction composed of elements approximately 0.5 to 2 micro in diameter; (b) a microsome fraction composed of submicroscopic elements approximately 80 to 150 mmicro in diameter; and, (c) a supernate fraction containing the soluble components of the extract. 2. The nature and origin of the constituents of liver extract is discussed. The large granule fraction is deemed to consist mostly of mitochondria and liver secretory granules, whereas the microsome fraction corresponds to the chromophilic ground substance of the hepatic cell. Phosphorus distribution in the supernate fraction, and ultraviolet absorption of the solution suggests that practically all the ribose nucleoproteins of liver extract are sedimentable, and occur in association with the large granules and microsomes. 3. The method of fractionation of liver suspension by differential centrifugation is being used as a means to investigate the chemical constitution of the morphological constituents of cytoplasm, and the distribution of biochemical activities in the cytoplasm of the hepatic cell. 4. The method of differential centrifugation is found to be applicable not only to the fractionation of cells but also, with the aid of auxiliary techniques, to the fractionation of much smaller elements, such as mitochondria. PMID- 19871555 TI - STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT : I. THE TRANSMISSION OF A COMMUNICABLE DISEASE TO MICE FROM NATURALLY INFECTED RATS. AB - A specific disease entity was established in white mice by the nasal instillation of lung and exudate suspensions from each of 14 adult albino rats affected with endemic pneumonia. The induced disease was characterized by pneumonia (96 per cent), otitis media (94 per cent), and rhinitis (30 per cent). It progressed slowly after an incubation period of 7 to 14 days and was attended by a variable mortality which reached 33 per cent in 22 weeks. Maintenance of the disease was regularly accomplished by direct transmission from mouse to mouse but only by the nasal route and only from the three foci of involvement. It was also transmissible by direct contact but required a prolonged period of exposure. The relation of the disease to infectious catarrh, which it closely resembles, is discussed. PMID- 19871556 TI - MOBILIZATION OF BASOPHILE SUBSTANCE (RIBONUCLEIC ACID) IN THE CYTOPLASM OF LIVER CELLS WITH THE PRODUCTION OF TUMORS BY BUTTER YELLOW. AB - Butter yellow (dimethylaminoazobenzene) causes degenerative changes in liver cells accompanied by chromatolysis of cytoplasmic structures that stain with basic dyes because they contain ribonucleic acid. These changes are profoundly modified by the protein content of the diet. Chromatolysis is succeeded by focal regeneration with reaccumulation of ribonucleic acid in the cytoplasm of liver cells; these foci of basophile hyperplasia have their origin in the parenchyma surrounding portal spaces and consist of cells arranged in columns or as tubules with lumina. Hepatomas arise from foci of basophile hyperplasia and corresponding with the arrangement of cells in these foci may be trabecular or adenomatous. Butter yellow causes new formation of bile ducts which arise chiefly in the immediate neighborhood of secondary portal spaces and produce the precancerous lesion, designated cholangiofibrosis. These bile ducts may accumulate ribonucleic acid in their cytoplasm and undergo hyperplasia. Cholangiomas arise from newly formed bile ducts that are the site of basophile hyperplasia. Changes accompanying chromatolysis and basophile hyperplasia aid in the definition of structural elements of the cytoplasm and in the localization of ribonucleic acid with relation to the mitochondria. PMID- 19871557 TI - REACTIONS OF MONKEYS TO EXPERIMENTALLY INDUCED INFLUENZA VIRUS A INFECTION : AN ANALYSIS OF THE RELATIVE ROLES OF HUMORAL AND CELLULAR IMMUNITY UNDER CONDITIONS OF OPTIMAL OR DEFICIENT NUTRITION. AB - 1. Macaca mulatta monkeys on a normal diet have proved resistant to intranasal but not to intratracheal inoculation of influenza virus. 2. Neutralizing antibodies appeared 8 to 10 days after inoculation with either living or heat inactivated virus. The antibodies were noted to be still present as long as 9 months after infection with living virus. 3. A specific granulopenic leucopenia characteristically followed primary influenza virus inoculation, regardless of altered conditions of diet, exposure, and route of inoculation, but it was not observed in monkeys previously infected with the same virus, all of which invariably survived. 4. Nutritional deficiency and exposure to cold increased the susceptibility of monkeys on intranasal instillation of the virus; the leucopenia was profound and fatalities frequently occurred even though neutralizing humoral antibodies developed as promptly and in relatively the same titer as under optimum nutritional conditions. PMID- 19871558 TI - TYPE-SPECIFIC PROTECTION AND IMMUNITY FOLLOWING INTRANASAL INOCULATION OF MONKEYS WITH GROUP A HEMOLYTIC STREPTOCOCCI. AB - 1. Nasopharyngeal carrier states of several weeks to several months duration were induced in the Macaca mulatta by the intranasal inoculation with matt strains of group A streptococci. 2. Following such a successful inoculation with a particular type of group A streptococcus, the animal was usually resistant to reimplantation with that same type for several months to a year or more, although reimplantation with a heterologous type could generally be easily effected. 3. This resistance was shown to be closely correlated with the antibodies directed toward the type-specific M antigen, not toward the T antigen of the strains employed. 4. A majority (83.8 per cent) of the animals in which intranasal inoculation was followed by successful implantation developed significant increases in the antistreptolysin O titres of their sera; and in a limited number of instances, type-specific agglutinins and bacteriostatic antibodies were demonstrable in the animals' sera following successful implantation. 5. Nasopharyngeal carrier states could not be induced with the glossy, avirulent variants of group A streptococci; these animals, moreover, failed to show antibody responses and were susceptible to implantation with the matt variants of the homologous glossy strains. 6. The findings are in accord with the known facts regarding immunity to group A streptococci gained through experiments on rodents; and the possible relationship of these observations to the problem of type specific immunity in human beings is discussed. PMID- 19871559 TI - PREPARATION AND PROPERTIES OF SHIGA TOXIN AND TOXOID. AB - 1. Shigella dysenteriae (Shiga) can, under the proper cultural conditions, produce a soluble toxin which is independent of the specific somatic polysaccharide antigen. A method is described for the rapid production of this toxin by an avirulent R variant of this organism. 2. The amount of bacterial protoplasm synthesized, and the yield of toxin produced, are very much increased when the culture is grown under conditions which favor aerobic metabolism and which do not permit accumulation of organic acids. 3. Although addition of an excess of inorganic iron to the medium does not interfere with the synthesis of bacterial protoplasm, maximal toxin production is obtained only in media which have been freed of the metal. 4. R Shiga bacilli grown under conditions of extreme aerobiosis at pH 7.0 in a simple medium free of inorganic iron and containing fumaric acid, glucose, meat extract, and peptone, give rise within 24 to 36 hours to cultures exhibiting a high degree of toxicity. The toxic principle rapidly becomes soluble as the cells die; it can be concentrated, purified, and freed of phosphorus by selective precipitation methods. 5. The toxin is fairly resistant to heat at pH 6.0 but rapidly denatured at pH 9.0. It is only slowly inactivated by trypsin. It filters readily and without loss of activity through anionic exchange resins but is precipitated and adsorbed by cationic resins which retain the nitrogen and toxic activity of the preparation. 6. The most active preparations of toxin available possess an LD(50) of 1 to 10 microg. for mice and rabbits. Young mice (up to 5 weeks of age) are more resistant than older animals. 7. The soluble toxin can be detoxified by treatment with 0.5 per cent formalin at pH 8.5; detoxification does not take place at lower pH whereas treatment at higher pH destroys specific antigenicity. Mice immunized with Shiga toxoid (in solution, or in the form of an alum precipitate) develop active immunity to the toxin. PMID- 19871560 TI - THE FATE OF INJECTED PARTICULATE ANTIGENS IN RELATION TO THE FORMATION OF ANTIBODIES. AB - Earlier studies have shown that the injection of antigenic material into the pad of the rabbit's foot is followed by the appearance of antibodies in the regional lymph node, in lymph coming from that node, and especially in the lymphocytes present in such efferent lymph. In the present work the fate of particulate antigenic material has been investigated during the period between its injection into the foot of the rabbit and the appearance of antibodies in the regional lymphatic tissue. It has been found that soluble substance of the same immunologic specificity as the antigenic material injected can be identified in extracts of the injected tissue and of the regional lymph node, and in the efferent lymph from that node. The concentration of this soluble material falls off slowly in the injected tissue in the course of the few days following the injection. It falls off quickly in the extract of the lymph node and in the lymph itself, and its disappearance is succeeded by the appearance of antibody. Evidence is presented that the immunologically active substance is derived from the injected antigenic material by a physiologic process, and this process is discussed as the means by which antigens, originally comprised in cells, are made available to the lymphocyte. PMID- 19871561 TI - THE SPECIFICITY OF SEROLOGICAL PRECIPITATION. AB - Precipitative mixing experiments have been conducted with the aid of a turbidimeter and a darkfield microscope. The results of these experiments, correlated with observations of macroscopic features, indicate that serological precipitation is largely governed by a highly specific mechanism except in the terminal period, when the operation of non-specific forces becomes apparent. The findings are used as the basis for a new description of precipitation in terms of the formation and aggregation of elementary particles of specific precipitate, called seromicrons. PMID- 19871562 TI - EFFECT OF IN VITRO CULTIVATION ON THE PATHOGENICITY OF WEST NILE VIRUS. AB - The West Nile virus was cultivated in suspended cell culture media employing several different tissue components, and it has been observed to survive in culture for at least 32 days. Continued propagation of the virus in vitro resulted in a change in its pathogenicity. The change lay in a marked reduction or a complete loss of the ability of the virus to produce fatal infections in mice and in hamsters on peripheral inoculation, although there was no obvious simultaneous alteration in the lethal effect of the virus by the cerebral route. In mice, the extent to which invasiveness was lost depended upon the passage level of the virus and the age of the test animals. The younger (and more susceptible) the mice, the greater the number of passages which was required to diminish the virulence of the virus by peripheral routes; after 68 passages, the virus still retained its full capacity to kill 3-day-old mice, while its ability to kill 8-day-old mice was reduced and its ability to kill mice 14 or more days of age was essentially abolished. How soon the loss of pathogenicity occurs in hamsters has not been determined. Prolonged cultivation rendered the virus avirulent for hamsters by the intraperitoneal route. PMID- 19871563 TI - INHIBITION OF PHOSPHORYLATION OF GLUCOSE IN MOUSE BRAINS BY VIRUSES AND ITS PREVENTION BY PREPARATIONS OF DIPHOSPHOPYRIDINE NUCLEOTIDE. AB - 1. Inhibition of glucose utilization in homogenates of brains of mice infected with poliomyelitis virus (Lansing strain) is reported. The inhibition occurs with glucose, or fructose-6-phosphate as substrate. No inhibition occurs in the presence of hexosediphosphate. 2. Brain homogenates of mice infected with the Theiler FA strain of mouse encephalomyelitis virus show inhibition ranging between 45 and 85 per cent (average 73 per cent). 3. Purified preparations of the Lansing and the Theiler FA strain invariably inhibit glycolysis when added to homogenates of normal mouse brain. A similar, but much less consistent inhibition is provoked by adding high concentrations of non-neurotropic viruses (influenza A and tobacco mosaic virus) to normal mouse brains. 4. The magnitude of inhibition caused by the purified virus is a function of the virus concentration and depends on temperature and time of incubation of the virus-brain mixture. 5. The inhibition of glycolysis in the brains of mice infected with Theiler FA virus and in normal brain-Theiler FA virus mixtures is prevented by the addition of preparations of DPN and glucose. PMID- 19871564 TI - EFFECT OF IN VITRO CULTIVATION ON THE PATHOGENICITY OF VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS. AB - Continued in vitro cultivation in a Maitland type medium resulted in a marked modification of the extraneural pathogenicity of the Venezuelan equine encephalomyelitis virus. The ability of the virus to induce lethal infections after peripheral inoculation was almost completely lost for mice 42 or more days of age, was somewhat reduced for mice 28 days of age, but was still retained for mice 21 or less days of age. The virulence of the virus by the cerebral route remained essentially unaffected for mice of any of the experimental age groups. Prolonged cultivation also resulted in almost complete attenuation of the virus for rabbits and guinea pigs by the intraperitoneal route. PMID- 19871565 TI - THE PRODUCTION OF CHRONIC GLOMERULONEPHRITIS IN RATS BY THE INJECTION OF RABBIT ANTI-RAT-PLACENTA SERUM. AB - 1. The injection of rabbit anti-rat-placenta serums in young adult rats produced chronic glomerulonephritis in 18 of 32 animals. 2. The course of the nephritis and the renal lesions were indistinguishable from those obtained in 11 of 13 animals injected with rabbit anti-rat-kidney serum. 3. Six instances of similar renal lesions occurred among 99 control animals. In 2 the rats had been injected with rabbit anti-rat-erythrocyte serum, in 2 with rabbit anti-rat-serum serum, while in 2 others the lesions were found among normal stock. PMID- 19871566 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : IV. THE SEROLOGICAL AND TOXIC PROPERTIES OF THE SOMATIC ANTIGENS. AB - 1. The toxicity of killed dysentery bacilli can be ascribed to the somatic antigen. Antibodies to intact dysentery bacilli apparently contain no toxin neutralizing antibodies other than those which precipitate the purified somatic antigen. 2. The serological properties of dysentery bacilli are determined by the specific somatic antigen. The specificity and cross-reactivity of the somatic antigen are dependent upon the carbohydrate moiety of the molecular complex. PMID- 19871567 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : V. A QUANTITATIVE STUDY OF THE SEROLOGICAL CROSS-REACTIONS. AB - A quantitative study of the serological cross-reactions of the somatic antigens of Types I, III, and I-III Shigella paradysenteriae has been made. From the results obtained it has been concluded that the somatic antigens of Shigella paradysenteriae (Flexner) Types I, III, and I-III are single chemical substances. The specificity and serological cross-reactions exhibited by these antigens are dependent upon similarities in their chemical constitutions. PMID- 19871568 TI - FURTHER STUDIES ON EFFECTS OF TISSUE EXTRACTS ON STAPHYLOCOCCUS AUREUS. AB - 1. The ability of alcoholic-precipitated extracts of beef tissue-brain, spleen, heart, and kidney-to stimulate the growth of Staphylococcus aureus, in vitro, and to convert the yellow S form to a white R variant with altered biochemical characteristics conforming to those of an avirulent organism, has been confirmed. 2. The avirulence of the white R variant has been established by tests in vivo on mice. 3. Staphylococcus aureus infections induced subcutaneously, intraperitoneally, and intravenously in mice responded favorably to brain extract following subcutaneous or oral administration. The mortality was 2 per cent in 444 experimental animals and 81 per cent in 448 control animals. 4. The extracts appeared equally efficient when used therapeutically (mortality 2 per cent of 162 experimental animals and 90 per cent in the control series) or prophylactically (mortality 2 per cent of 282 experimental animals and 76 per cent in 286 control mice). Extracts of brain and spleen were more effective than those of either heart or kidney. 5. Studies concerning the mechanism of action of the tissue extracts indicate that they prevented the formation of toxin by Staphylococcus aureus, and had but little effect on toxin actions. 6. Toxicity tests revealed that the brain and spleen extracts were relatively non-toxic, dosages equivalent to 2 per cent of the body weight being well tolerated. Kidney and heart extracts were much more toxic, producing mortality in dosages as low as 0.3 per cent of the body weight. PMID- 19871569 TI - REACTIONS OF MONKEYS TO EXPERIMENTALLY INDUCED STREPTOCOCCUS HEMOLYTICUS, GROUP C, INFECTION : AN ANALYSIS OF THE RELATIVE ROLES OF HUMORAL AND CELLULAR IMMUNITY UNDER CONDITIONS OF OPTIMAL OR DEFICIENT NUTRITION. AB - Macaca mulatta on a normal diet proved to be resistant on intranasal inoculation with Streptococcus hemolyticus, group C. More than half of the monkeys maintained for various periods on a modified dietary regimen deficient in vitamin B became more or less anemic. All developed a granulopenic leucopenia during which many developed spontaneous infections, and all were extremely susceptible on intranasal instillation of Streptococcus hemolyticus, group C. In normal monkeys, primary inoculation with the streptococcus resulted in an immediate marked neutrophilic leucocytosis. In the nutritionally deficient animals with leucopenia, only an abortive transitory leucocytosis was observed. Following reinoculation with the same strain of hemolytic streptococci in normal healthy monkeys, the prompt leucocytic response originally observed, failed to develop, yet the animals remained asymptomatic. In the first instance the opsonic index remained low at the preinoculation base line level, but in the second, a sharp increase in the opsonic index occurred in several days. This humoral response apparently rendered unnecessary the quantitative granulocytic leucocytosis associated with survival in the first instance. There was no demonstrable difference in time of appearance or titer of the antibody responses, i.e. precipitins, antistreptolysins, and opsonins between the normal and nutritionally deficient monkeys. Synthetic folic acid (L. casei factor) relieved both leucopenia and anemia promptly in the "vitamin M"-deficient monkeys, with increase in resistance to endogenous infection when this supplement was given sufficiently promptly. PMID- 19871570 TI - INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS : I. IN VIVO STUDIES WITH THE VIRUSES OF WESTERN AND EASTERN EQUINE ENCEPHALOMYELITIS, ST. LOUIS ENCEPHALITIS, POLIOMYELITIS (LANSING), AND RABIES. AB - Anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (Eastern or Western type) or with the St. Louis encephalitis virus. No comparable effect is observed in experimental infections produced with rabies or poliomyelitis (Lansing) viruses. The neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ether anesthesia are caused by viruses which apparently are not destroyed by ether in vitro. Another striking difference between these two groups of viruses is their pathogenesis in the animal host; those which are inhibited in vivo by ether anesthesia tend to infect cells of the cortex, basal ganglia, and only occasionally the cervical region of the cord. On the other hand, those which are not inhibited in vivo by ether anesthesia tend to involve cells of the lower central nervous system and in the case of rabies, peripheral nerves. This difference is of considerable importance in view of the fact that anesthetics affect cells of the lower central nervous system only in very high concentrations. It is obvious from the complexity of the problem that no clear-cut statement can be made at this point as to the mechanism of the observed effect of ether anesthesia in reducing the mortality rate in certain of the experimental neurotropic virus infections. Important possibilities include a direct specific effect of diethyl ether upon the virus and a less direct effect of the anesthetic upon the virus through its alteration of the metabolism of the host cell. PMID- 19871571 TI - EXPERIMENTAL VIBRIO INFECTIONS OF DEVELOPING CHICK EMBRYOS. AB - Developing chick embryos are highly susceptible to infection with strains on V. cholerae representing Gardner and Venkatraman's 6 groups and the types Inaba and Ogawa. There is a moderate decrease in susceptibility with advancing age of the embryo. The influence of dosage on survival rates is not marked, probably because a minimal dose, consisting of a very few organisms, is sufficient to produce death rapidly. Passive protection of a low order is conferred on the embryos by the introduction of inactivated specific immune serum at the time of inoculation of vibrios. This protective influence is enormously enhanced by the previous or simultaneous administration of guinea pig complement. The antigens of group I organisms which give rise to embryo-protective and bacteriolytic antibodies are dual in character. One antigen is shared by all members of the group and is productive of antibodies which will protect against infections with all strains of the group, of whatever type. The other antigen is type-specific, and its antibodies are protective and lytic only for organisms of the homologous type. PMID- 19871572 TI - NUTRITION OF THE HOST AND NATURAL RESISTANCE TO INFECTION : II. THE DIETARY EFFECT AS CONDITIONED BY THE HETEROGENEITY OF THE TEST PATHOGEN POPULATION. AB - The property of a diet of whole wheat and whole dried milk to promote a higher survival rate among a stock of heterogenetic, outbred W-Swiss mice subjected to S. enteritidis infection, over that promoted by a "synthetic" diet, has been shown to be a function of the infecting bacterial population. Broth cultures so prepared as presumably to yield S. enteritidis organisms of uniform character have consistently failed to reveal an effect of diet on natural resistance, even though the parent bacterial populations revealed a dietary effect. The dietary difference effect on natural resistance could not be demonstrated with an avirulent culture of S. typhimurium, or with a freshly prepared virulent culture of S. typhimurium presumably uniform in character. The dietary effect on natural resistance was demonstrated by employing a 1:1 mixture of avirulent and virulent cultures of S. typhimurium. PMID- 19871573 TI - IMMUNITY IN MUMPS : IV. THE CORRELATION OF THE PRESENCE OF COMPLEMENT-FIXING ANTIBODY AND RESISTANCE TO MUMPS IN HUMAN BEINGS. AB - Of 163 persons giving positive complement fixation tests who were exposed to mumps, 1 afterwards developed the disease; of 285 negative reactors similarly exposed, 56 afterwards came down with mumps. Of 78 individuals subjected to intimate exposure to mumps whose tests were originally negative and who failed to develop the disease, 41 per cent gave positive reactions when tested 1 month later. Seventy-seven per cent of complement fixation tests done on the sera of 565 normal adults who admitted a previous attack of mumps were positive. A similar correlation was recorded in tests on the sera of a small group of children with positive histories. Of 356 medical students admitting previous attacks, 80 per cent gave positive tests. Of 386 normal adults who denied previous attacks, 42 per cent gave positive tests; of 85 children giving negative histories, 38 per cent reacted positively. The results of complement fixation tests on the sera of 1665 normal adults (over 17 years) and 679 children (1 to 17 years) are recorded. It has been shown that 63 per cent of the adults and 57 per cent of the children had antibody in their blood which reacted with the virus of mumps. In groups in which exceptionally intense exposure was not known to have occurred in the past, the proportions of positive reactors were: adults, 61 per cent; children, 49 per cent. In contrast to these normal persons, the incidence of positive reactors among permanently institutionalized mental defectives was 38 per cent of 356 adults and 32 per cent of 475 children. In only 2 per cent of 320 normal adults and children did the titer of complement-fixing antibody reach 1 192. In no instance in which the endpoint was determined was a higher titer recorded. The results of complement fixation tests on the sera of mother and newborn infant were essentially the same in 5 instances. PMID- 19871574 TI - IMMUNITY IN MUMPS : V. THE CORRELATION OF THE PRESENCE OF DERMAL HYPERSENSITIVITY AND RESISTANCE TO MUMPS. AB - The results of skin tests read at 48 hours on several hundred adults and children in which heat-inactivated mumps virus was the antigen have been presented and discussed. They can be summarized as follows:- Of 89 persons tested before the onset of mumps, 89 per cent exhibited erythematous reactions 10 mm. or less in diameter and 95 per cent, reactions 15 mm. or less in diameter. Of 40 persons tested during the first 5 days of mumps, 95 per cent exhibited reactions 10 mm. or less and 98 per cent reactions 15 mm. or less. Of 480 exposed persons the attack rate of mumps was 46 per cent among 340 with reactions 10 mm. or less and 10 per cent among 240 with reactions greater than 10 mm. The attack rate was only 2 per cent among 161 with reactions exceeding 15 mm. The attack rates in 13 skin tested groups which were exposed to mumps tended to be inversely proportional to the incidence of reactions exceeding 10 mm. The incidence of reactions exceeding 10 mm. was approximately twice as high among 529 adults (persons 18 years or older) as it was among 306 children (persons under 18 years). Of 179 adults giving positive histories of mumps, 82 per cent exhibited skin reactions exceeding 10 mm. In certain groups the correlation between history and positive skin test was as high as 0.9. Of 132 adults giving negative histories, 58 per cent exhibited skin reactions of this magnitude. The proportion of reactions exceeding 10 mm. in a small number of children giving positive histories was 75 per cent. The proportion of reactions less than 10 mm. was 15 per cent. Of 167 adults with positive complement fixation tests, 87 per cent exhibited skin reactions exceeding 10 mm. Of 111 adults with negative complement fixation tests, 52 per cent exhibited reactions exceeding 10 mm. Of 43 children with positive complement fixation tests, the skin test reactions exceeded 10 mm. in 70 per cent. The skin reactions exceeded 10 mm. in 29 per cent of 105 children with negative complement fixation tests. In 69 of 72 individuals in whom skin reactions exceeded 10 mm., complement-fixing antibody either appeared in the blood or increased in amount within about 2 weeks after the tests were done. Such antibody responses likewise were observed in 34 of 76 individuals in whom skin reactions were 10 mm. or less. The data summarized up to this point were obtained with virus derived from the infected parotid gland of monkeys. The results of simultaneous tests in 82 individuals employing materials prepared from infected monkey parotid gland and amniotic membrane of chick embryos infected with mumps virus indicated in general that the same individual responded in a similar manner to both antigens. In many instances, however, the membrane material produced weaker reactions. Occasionally an individual failed to react at all to one of these materials but did respond to the other. PMID- 19871575 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMOCOCCAL PNEUMONIA : II. THE EFFECT OF SULFONAMIDE THERAPY UPON THE PULMONARY LESION OF EXPERIMENTAL PNEUMONIA. AB - Experimental pneumococcal pneumonia was produced in albino rats by intrabronchial inoculation of Type I pneumococci suspended in mucin. The resulting pneumonia was uniformly fatal in untreated rats. Eighty per cent of the animals so infected and treated with sulfonamide drugs 6 hours after inoculation survived the pneumonia. At the end of 1 week the surviving animals were sacrificed, and examination of the lungs showed sharply demarcated localized pulmonary lesions containing no pneumococci. Microscopic study of the lungs of treated animals sacrificed at 6, 18, 42, 66, 96, and 168 hours after the start of treatment revealed the following sequence of events. During the first 18 hours the drug apparently had little effect upon the pneumonic lesion, but at the end of 18 hours pneumococci in the edema zone began to show striking changes in their morphology, indicating bacteriostesis. Forty-two hours after the start of treatment the edema zone had disappeared, the pneumonia had ceased to spread, and the pneumococci at the margin of the lesion had been overtaken by leucocytes. Careful examination of the exudate in the periphery of the lesion revealed definite phagocytosis of pneumococci. By the 4th day no pneumococci could be found in the stained sections, and after 1 week there remained only macrophages in the rapidly clearing alveoli. In order to demonstrate the phagocytic reaction more clearly the effect of sulfonamide drugs was studied in pneumonic rats previously rendered leucopenic by exposure to x-ray. The pneumonia in these animals was relatively acellular, and the few macrophages present in each alveolus could be seen to have phagocyted large numbers of pneumococci after 18 to 42 hours of treatment. The macrophages not only phagocyted the pneumococci but ultimately destroyed them, the pneumonic lesion later going on to complete resolution. The fact that this phagocytic reaction was observed in the lungs of animals with bacteremia suggests that the phagocytosis is independent of circulating type-specific opsonins. PMID- 19871576 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMOCOCCAL PNEUMONIA : III. FACTORS INFLUENCING THE PHAGOCYTOSIS OF PNEUMOCOCCI IN THE LUNG DURING SULFONAMIDE THERAPY. AB - The phagocytosis which occurs in the lungs of rats receiving sulfonamide is due neither to an opsonizing action of the sulfonamides nor to type-specific antibody. The evidence presented indicates that the destruction of the pneumococci is brought about by a phagocytic mechanism independent of both opsonization and capsular injury. PMID- 19871577 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMOCOCCAL PNEUMONIA : IV. THE MECHANISM OF PHAGOCYTOSIS IN THE ABSENCE OF ANTIBODY. AB - 1. Evidence has been presented in previous publications that the phagocytosis of pneumococci in the pneumonic lung during chemotherapy is due neither to specific opsonins nor to capsular injury (1, 2). The present studies have shown that the phagocytosis taking place in the lung is independent of any sort of intermediary factor and results from a direct action of the phagocytic cells upon the pneumococci. 2. Phagocytosis in the absence of antibody has been demonstrated not only in the lungs of living rats but in formalin-fixed lungs, on the surfaces of a variety of tissues (both freshly removed from the animal and previously "killed" with heat), and on the surfaces of such inert materials as moistened filter paper, cloth, and fiber glass. On the other hand, smooth materials such as glass, cellophane, albumin, and paraffin have failed to support the phagocytic reaction. This latter observation indicates that the physical character of the surface to which the leucocytes have access constitutes a determining factor in the non-antibody mechanism of phagocytosis. 3. Further experiments have defined the relationship of "surface phagocytosis" to that induced by specific opsonins. The non-antibody mechanism was found to operate only upon surfaces of suitable physical properties, whereas opsonins enabled phagocytes floating freely in a fluid medium to engulf the fully encapsulated organisms. 4. Direct visualization of the surface phenomenon in the lung revealed that leucocytes phagocyte the virulent organisms in the absence of antibody only after having trapped them against the alveolar walls. Once the encapsulated pneumococci have been ingested, they can be seen to undergo digestion within a few hours. The discovery of the phenomenon of surface phagocytosis affords clarification of previously unanswered problems concerning the mechanism of recovery in pneumococcal pneumonia. PMID- 19871578 TI - IMMUNITY IN EXPERIMENTALLY INDUCED INFECTIOUS HEPATITIS. AB - 1. 9 human volunteers, convalescent from infectious hepatitis experimentally induced by a strain of virus employed in this laboratory, were resistant when reinoculated with the same strain of virus, 6 to 9 months later. 2. 8 out of 12 previously healthy control subjects developed infectious hepatitis with jaundice following administration of this same material. 3. The demonstration of homologous immunity produced by this strain of virus is in agreement with the demonstration by others of homologous immunity produced by another strain of infectious hepatitis virus. PMID- 19871579 TI - IMMUNITY IN MUMPS : VI. EXPERIMENTS ON THE VACCINATION OF HUMAN BEINGS WITH FORMOLIZED MUMPS VIRUS. AB - The results observed after experimental inoculation of active mumps virus into 41 vaccinated and 32 unvaccinated children,-with the consent of their parents or guardians,-indicated that formol-inactivated mumps virus obtained from the parotid gland of the infected monkey and employed as a vaccine in the manner which has been described increased the resistance of about half of those to whom it was administered. PMID- 19871580 TI - STUDIES ON HERPETIC INFECTION IN MICE : IV. THE EFFECT OF SPECIFIC ANTIBODIES ON THE PROGRESSION OF THE VIRUS WITHIN THE NERVOUS SYSTEM OF YOUNG MICE. AB - Two-week-old mice inoculated with herpes virus on the pad of a hind foot regularly developed paralysis of the infected limb followed by paraplegia and encephalitis terminating fatally 5 or 6 days after inoculation. Hyperimmune rabbit serum given intraperitoneally at the time virus was inoculated on the foot pad prevented the formation of an herpetic lesion of the foot pad. When the antiserum was given 12 hours after inoculation of the virus, a typical infection of the epithelium of the foot pad developed, but the virus was prevented from causing obvious signs of infection of the nervous system in many of the animals. Amputation of the foot 2 hours after the inoculation of the virus prevented the paralysis of the hind leg. Some of the mice died of a delayed encephalitis. Amputation of the foot at 24 hours neither prevented nor delayed the sequence of paralysis of the hind leg, encephalitis, and death. In order to study immune serum therapy of an infection of the nervous system uncomplicated by a peripheral focus of infection or by traumatic disturbance of the central nervous system, 2 week-old mice were inoculated on the foot pad, the infected feet were amputated 24 hours later, and the immune serum was administered at varying intervals thereafter. Using litter mate controls and statistically significant numbers of mice, it was shown that hyperimmune rabbit serum, administered during the first one-third of the incubation period, retards and, in some cases, arrests the progress of herpetic infection within the nervous system. PMID- 19871581 TI - THE PROPERTIES OF T ANTIGENS EXTRACTED FROM GROUP A HEMOLYTIC STREPTOCOCCI. AB - 1. T antigens of group A hemolytic streptococci have been obtained in soluble form by digestion of the bacterial cells with pepsin or trypsin. Large quantities of this antigen were readily extracted from type 1 strains, whereas only small amounts could be obtained from strains of other types. 2. The T antigen, prepared in this way from a type 1 strain, was partially purified by chemical precipitation and further enzymatic digestion. An active fraction, apparently protein in nature, was separated electrophoretically at pH 7.00. The separated material, pooled and analyzed at the same pH, gave only a single peak. The isoelectric point of this substance was about pH 4.50. An elementary analysis was obtained. Although the T antigen was resistant to digestion with proteolytic enzymes and ribonuclease, it was readily inactivated by heat, especially in acid media and in strong salt solutions. The serological activity of this purified T substance was lost after exposure to ultraviolet radiation. 3. Analysis by means of the ultracentrifuge showed that the material was polydisperse and therefore probably impure. 4. The soluble form of the T substance was active in the precipitin reaction, in the fixation of complement, in inhibition of T agglutination, and as an antigen when injected into rabbits. The antibodies produced did not protect mice against infection with virulent strains of hemolytic streptococci containing the same T antigen. 5. The immunological specificity of T antigen in soluble form is the same as that of the T antigen in the intact streptococcus from which it was derived. PMID- 19871582 TI - THE PRESSURE AND INTERSTITIAL RESISTANCE PREVAILING IN THE NORMAL AND EDEMATOUS SKIN OF ANIMALS AND MAN. AB - Means have been described for the study of pressure conditions in normal and pathological skin of living human beings and mice. The true pressure in normal skin cannot be measured directly by any of the means hitherto described, because there is insufficient free fluid to make manometric determinations. However, for practical purposes, the intracutaneous pressure has been approximately estimated by introducing into skin exceedingly small amounts of a relatively unabsorbable fluid, a mixture of Locke's solution and a vital dye, and then finding the least pressure required to overcome the resistance of the skin to the passage of this fluid through it at the lowest rate measurable with accuracy by the apparatus at hand. In the present paper measurements of this pressure have been termed the interstitial resistance. In normal skin the interstitial pressure, as estimated by measurements of the interstitial resistance, is low, slightly less, on the average, than 1.7 cm. of water in the skin of the mouse, and less than 3.1 cm. of water in human skin. It remains unchanged in states of active hyperemia. In edematous skin the interstitial pressure can be directly measured by determination of the edema fluid pressure. It has been compared with determinations of the interstitial resistance and found to be only 0.5 cm. of water lower in both the mouse and man. Under the conditions of our experiments, in skin rendered slowly edematous by the introduction of irritant chemicals or their topical application, little rise in pressure took place. On the other hand, in rapidly forming edema of the skin the edema fluid pressure and the intradermal interstitial resistance rose and became great enough to hinder materially the further escape of fluid from the blood vessels. The edema fluid pressure rose in proportion to the rapidity with which the edema formed. When a rapidly formed edema subsided, the edema fluid pressure and interstitial resistance fell, but if inflammation and induration followed later, the interstitial resistance became high again. As these conditions subsided the interstitial resistance fell, at times to normal levels, even in the presence of edema. In mouse skin injured by squeezing according to a standard procedure, with result in pronounced edema, the intradermal interstitial resistance rose within a few hours to levels of 10 to 15 cm. of water. In those instances in which the injury progressed to induration, the interstitial resistance rose to such high levels that it seemed impossible that fluid could continue to escape from the capillaries. Such a state of affairs may be of great importance in determining whether necrosis follows trauma. PMID- 19871583 TI - THE EFFECTS OF VENOUS OBSTRUCTION UPON INTERSTITIAL PRESSURE IN ANIMAL AND HUMAN SKIN. AB - The changes of intracutaneous pressure in the limbs of mice and human beings have been followed during and after periods of venous obstruction with almost unhindered arterial flow. During the first 30 minutes of obstruction the interstitial pressure in the tense skin of the lower legs of mice, a pressure which is slightly higher than that in the loose skin of the ears, backs, and thighs (21), rose from 2.6 to 4.6 cm. of water to about 32 cm., thereafter remaining constant. It would appear that the escape of fluid from the capillaries is checked at this pressure. In the skin of the arm and leg of man the interstitial pressure rose from 2.5-3.7 cm. of water to 15.0-23.0, within 15 to 27 minutes after venous obstruction had been produced, mounting no higher during the period of observation. When venous obstruction had existed for about 20 minutes or more the subjects sometimes experienced sensations of relief from congestion as if some tissue adjustment or the opening of some venous by-pass in the marrow had occurred, preventing a further rise of pressure. However this may be, the pressures still appeared to be great enough to prevent further escape of fluid from the capillaries, at least for the time being. PMID- 19871584 TI - CHEMICAL STUDIES ON HOST-VIRUS INTERACTIONS : I. THE EFFECT OF BACTERIOPHAGE ADSORPTION ON THE MULTIPLICATION OF ITS HOST, ESCHERICHIA COLI B WITH AN APPENDIX GIVING SOME DATA ON THE COMPOSITION OF THE BACTERIOPHAGE, T2. AB - The addition of active or irradiated T2 bacteriophage and T4 bacteriophage to E. coli B stops bacterial multiplication. The respiratory rate and respiratory quotient of the inhibited bacteria remained at the values observed just before infection. A respiratory rate decrease which occasionally appears can be roughly correlated with change of turbidity of the suspension. An intracellular inhibitor of multiplication appears to be liberated into lysates. A similar substance has been separated from normal E. coli B after sonic disintegration. These bacteriostatic preparations contain cytoplasmic granules with lactic acid dehydrogenase activity. The relationship of these phenomena to the interference effect in this system and others has been considered. PMID- 19871585 TI - CHEMICAL STUDIES ON HOST-VIRUS INTERACTIONS : II. THE CHEMICAL SIMULATION OF THE INTERFERENCE PHENOMENON BY 5-METHYL TRYPTOPHANE. AB - 5-methyl tryptophane inhibited the multiplication of E. coli B without apparently affecting the rate of its oxygen utilization or R. Q. in a synthetic medium. E. coli B, under conditions of inhibition in the presence of this compound, was infected with the bacterial viruses T2 or T4. Infected organisms, in the presence of this compound, were unable to reproduce virus, assayable by the plaque method. Indeed, the number of infectious centers disappeared at a logarithmic rate in the presence of 5-methyl tryptophane, although the compound did not reduce the titers of B, T2, or T4, when the bacteria or viruses were exposed separately to the agent. In contrast to the irreversibility of the interference effects induced by viruses, the effects induced by short exposures to 5MT appear to be reversible on removal of the compound. PMID- 19871586 TI - THE ACTIVATING EFFECT OF MAGNESIUM AND OTHER CATIONS ON THE HEMOLYTIC FUNCTION OF COMPLEMENT. AB - 1. The evidence presented indicates that Mg(++), or other cation such as Ca(++), Ni(++), or Co(++), is essential for the hemolytic action of C'. Ca(++), Ni(++), and Co(++) are less effective than Mg(++). The hemolytic system usually does not contain sufficient Mg(++) for optimal hemolytic activity so that a marked enhancement can be obtained by addition of extra Mg(++). 2. The enhancing action of tissue fluids can be ascribed to their contribution of Mg(++). 3. Substances which bind Mg(++) and Ca(++) are anticomplementary when added to the usual hemolytic system which contains only a small quantity of Mg(++). This type of anticomplementary effect can be overcome by addition of extra Mg(++). 4. Ca(++) may also be essential to the lytic process but its action is much less pronounced than that of Mg(++). PMID- 19871587 TI - FLUORESCEIN CIRCULATION TIME AS A PROGNOSTIC SIGN IN EXPERIMENTAL TRAUMATIC SHOCK. AB - Repeated determinations of the circulation time by the fluorescein method were made in normal and shocked dogs. In normal animals the circulation time ranges from 9 to 16 seconds with an average of 12.6 seconds. In traumatic shock the circulation time is invariably prolonged. For prognosis in the traumatized animal two determinations of fluorescein circulation time separated by an interval of 1 hour are essential. If the second circulation time is longer than the first and both are over 30 seconds, the animal will not survive without therapy. On the other hand, if the second circulation time is below 25 seconds or is considerably shorter than the first, the prognosis is good. In many of these experiments the change in circulation time appeared to be the earliest index of eventual recovery or death. It gave a clue to the fate of the animal when no decisive judgment could be made from the blood pressure and heart rate. In three dogs the cyanide and fluorescein circulation times were compared during shock. It was found that the cyanide circulation time, though increased in shock, remained at a fairly constant value while over the same period the fluorescein circulation time showed progressive changes. This discrepancy between the cyanide and fluorescein methods may be explained by the fact that the former does not include the minute peripheral systemic circulation. Since the study of shock is concerned with tissue anoxia and is primarily a phenomenon of the failure of the peripheral circulation, it is important to choose procedures such as the fluorescein method as a measure of the condition of the peripheral vascular system. PMID- 19871588 TI - THE CONSTRUCTION AND OPERATION OF EXPERIMENTAL ROOMS FOR THE STUDY OF AIR-BORNE INFECTION. AB - This communication describes the construction and operation of two identical experimental rooms in which it is possible to produce and maintain a wide range of temperature and humidity with or without exchange of the room air. The ability to maintain a large air mass under constant conditions makes it possible to study the effects of different atmospheric states on air-suspended bacteria and viruses in relation to their survival, particle size, humidification, killing by lethal vapors, and host susceptibility. A brief description of the functioning of the rooms under experimental conditions is given. PMID- 19871589 TI - STUDIES ON MALARIAL PARASITES : VI. THE CHEMISTRY AND METABOLISM OF NORMAL AND PARASITIZED (P. KNOWLESI) MONKEY BLOOD. AB - 1. Normal monkey, Macaca mulatta, plasma and red cells are similar in their inorganic composition to those of human beings. Inorganic phosphate values of plasma and red cells from parasitized monkey blood are lower than normal. Plasma potassium values are higher than normal particularly during segmentation. Other inorganic components of parasitized blood show little variation from normal. 2. Monkey red blood cells parasitized with P. knowlesi consume oxygen in the presence of glucose, lactate, glycerol, and amino acids as substrates. Their respiration is inhibited by cyanide, carbon monoxide, and high oxygen tensions. Normal monkey red blood cells consume oxygen at an appreciable rate only in the presence of methylene blue. 3. Parasitized erythrocytes convert glucose to lactate at a rate 25 to 75 times that of the normal monkey erythrocyte. Unlike the normal red cell, the parasitized cell utilizes lactate if oxygen is present. Lactate is utilized, however, at a rate that is only one-sixth that of its production from glucose. 4. The significance of these findings in relation to the problem of cultivation of malarial parasites is discussed. PMID- 19871590 TI - STUDIES ON MALARIAL PARASITES : VII. METHODS AND TECHNIQUES FOR CULTIVATION. AB - 1. Methods of recovering adequate amounts of Plasmodium knowlesi from the monkey (Macaca, mulatta) for biochemical studies and in vitro cultivation are described. Concentrates of red blood cells parasitized with P. knowlesi can be obtained by differential sedimentation of parasitized blood because of physical and chemical changes produced by the parasites in the host cell and the plasma of the blood. 2. Two different techniques, the rocker-dilution and the rocker-perfusion methods, are described for the cultivation of malarial parasites. Details of the apparatus, assembly, and sterilization are given, as well as methods of counting and evaluating parasites. 3. In a series of 235 control experiments for 20 to 24 hours using three types of apparatus, the average rate of multiplication was 3.9. Each technique has specific value for studying the various aspects of metabolism, nutrition, and the action of antimalarial drugs. PMID- 19871591 TI - STUDIES ON MALARIAL PARASITES : VIII. FACTORS AFFECTING THE GROWTH OF PLASMODIUM KNOWLESI IN VITRO. AB - 1. Methods have been described for the preparation and sterilization of a synthetic nutrient medium which supports normal growth during one 24 hour asexual cycle of the erythrocytic form of P. knowlesi. 2. Successive subcultures with good multiplication can be carried out when whole blood or plasma is added to the medium. Data are presented from two such experiments where the sixth and seventh generations, respectively, were injected into normal monkeys. In both cases, the injections produced clinical malaria and in one, an abnormally severe course was observed. 3. A high percentage (95 per cent) of O(2) inhibits multiplication in in vitro cultures. A gas phase approximating alveolar air permits normal development. A lower percentage (0.37 per cent) of O(2) in the gas phase supports growth at least as well. 4. Certain experiments indicate that in vitro growth is better supported in normal monkey plasma than in plasma from parasitized monkeys. Heating of parasitized plasma to 56 degrees C. for 30 minutes removed the deleterious effect. 5. A nutritional need by the parasite for glucose and p aminobenzoic acid has been shown. Attempts to demonstrate the need for other individual components of the nutrient medium have not been successful though the effect of the absence of blocks of nutrient such as purines and pyrimidines, amino acids, or water-soluble vitamins can be observed. 6. Further assay of the nutritional requirements of the parasite appears to be hampered by the supply of nutrient furnished by the red cells and plasma. Cultivation of parasitized cells washed free of plasma and resuspended in synthetic medium containing 1 per cent serum albumin has been accomplished as one step directed toward the removal of such interfering factors. PMID- 19871592 TI - STUDIES ON THE TOXICITY OF INFLUENZA VIRUSES : I. THE EFFECT OF INTRACEREBRAL INJECTION OF INFLUENZA VIRUSES. AB - Intracerebral injection of preparations of influenza viruses into mice led to tonic and clonic convulsions and death in tetanus, usually within 24 to 72 hours. Histological examination revealed the destruction of the ependymal lining of the ventricles as the dominant finding. These reactions were obtained in four different strains of mice as well as in rats, guinea pigs, and hamsters. They were observed in mice after injection of mouse and egg-adapted virus, and all strains of virus tested gave these responses as long as sufficient quantities of the agents were injected. Control materials, such as normal allantoic fluids, particulate components of normal chorio-allantoic membranes, and suspensions of normal murine lungs, gave uniformly negative results. Activation of a latent virus as well as the inadvertent admixture of a neurotropic agent to the influenza cultures was excluded. Propagation of the influenza viruses in the central nervous system could not be demonstrated and, in fact, the agents were no longer demonstrable in 4 days. It was concluded that the observed neurological reactions were the result of toxic activities rather than of virus propagation. Comparison between the infectivity, hemagglutinating capacity, and the toxic activity showed that preparations with the higher titers of virus and hemagglutinin were also the more toxic ones. The toxic agents could not be separated from the infectious particles by the use of such technics as differential high speed centrifugation, adsorption onto and elution from chicken red cells, and precipitation by protamine. The toxic effect of influenza A virus preparations was specifically neutralized by anti-influenza A and not by anti influenza B serum, and conversely. In addition, antigenic differences were noted between two strains of influenza A virus by this method of testing. PMID- 19871593 TI - STUDIES ON THE TOXICITY OF INFLUENZA VIRUSES : II. THE EFFECT OF INTRA-ABDOMINAL AND INTRAVENOUS INJECTION OF INFLUENZA VIRUSES. AB - Upon intra-abdominal or intravenous injection of allantoic fluids infected with influenza viruses, mice frequently died within 8 to 96 hours. Similar results were observed upon injection of rabbits, rats, and guinea pigs. Autopsy of the mice revealed widespread necrosis of liver and spleen, hemorrhages into the intestines, pleural exudation, and other occasional findings. Survivors frequently developed pulmonary consolidation or jaundice. The dominant type of lesion depended on the strain of virus used. All attempts to demonstrate propagation of the influenza viruses outside of the respiratory tract failed. It was concluded that the early lesions were the result of toxic activities of the virus and not of virus multiplication in the affected tissues. Injection into chick embryos of highly diluted inocula produced higher titers of virus, hemagglutmin, and toxicity in the allantoic fluids than the use of more concentrated seed culture. Serial passage of various strains in high dilution frequently increased the toxic activity. The infectivity often reached its peak in 24 hours when tests for toxicity were still negative. Maximal toxicity was usually not attained before 48 hours. The toxic activity could not be separated from the infective property by such means as differential centrifugation and adsorption onto and elution from chicken red cells. However, upon heating, formalinization, and irradiation with ultraviolet light, the ability of the agents to propagate was lost at a faster rate than the toxic property. The toxic property remained stable for 2 to 3 months at 4 degrees C. This stability was comparable to that of the infectivity for chick embryos. Specific immune sera neutralized in high dilution the toxic activity of the homologous virus. Non specific neutralization occurred in low dilutions of normal and heterologous immune sera. Strain differences were indicated by this method of testing. Vaccination of mice by the subcutaneous or intra-abdominal routes protected mice specifically against the toxic effects of intra-abdominally or intravenously injected preparations of virus. PMID- 19871594 TI - DISSOCIATION OF HEMAGGLUTINATING AND ANTIBODY-MEASURING CAPACITIES OF INFLUENZA VIRUS. AB - Preparations of Type B influenza virus, propagated in the embryonated egg and obtained in the form of allantoic fluid, were found after heating at 56 degrees C. for 30 minutes to retain the capacity to agglutinate erythrocytes but no longer measured specific antibody when used as antigen in titrations of serum antibody. The dissociation of the two activities suggests the presence in such virus preparations of a complex virus antigen comprising, (1) a heat-stable component which agglutinates erythrocytes and reacts primarily with specific antibody; (2) a heat-labile component reacting with a factor of normal serum which ordinarily tends to inhibit the hemagglutinating activity of influenza virus. The relation of the reagents to other known serological activities of influenza virus is being studied. PMID- 19871595 TI - THE RAPID PRODUCTION OF ACUTE DISSEMINATED ENCEPHALOMYELITIS IN RHESUS MONKEYS BY INJECTION OF HETEROLOGOUS AND HOMOLOGOUS BRAIN TISSUE WITH ADJUVANTS. AB - 1. A picture resembling acute disseminated encephalomyelitis in the human being has been regularly and rapidly produced in rhesus monkeys by injection of emulsions of adult rabbit and monkey brain administered with adjuvants. 2. No lesions of the central nervous system resulted from injection of similar emulsions of fetal rabbit brain or adult rabbit lung. 3. A description of the gross and histological findings in the central nervous system is given and compared with features of human demyelinating disease. 4. The experimental findings are in accord with the hypothesis that antibody to the injected brain emulsion reacts with the tissues of the nervous system of the animal to produce the pathological changes. PMID- 19871596 TI - ALLERGIC ENCEPHALOMYELITIS IN MONKEYS IN RESPONSE TO INJECTION OF NORMAL MONKEY NERVOUS TISSUE. AB - By subcutaneous injection of central nervous tissue emulsified with adjuvants according to Freund's technique it has been possible to induce in the majority of monkeys an acute disseminated encephalomyelitis which is interpreted as an isoimmunization to CNS tissue. Positive reactions occurred only in response to CNS tissue containing white matter; i.e., cerebral white matter, spinal cord (whether normal or poliomyelitis-infected), and cortical "gray" matter (with an estimated 10 per cent contamination with white matter). No reaction occurred when peripheral nerve or kidney suspension or saline alone was injected with adjuvants. The perivascular and extravascular infiltration induced was confined to the CNS. PMID- 19871597 TI - CENTRIFUGATION STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) : THE RELATIVE SIZES OF FREE AND COMBINED VIRUS. AB - A technique has been devised for obtaining free or uncombined pneumonia virus of mice (PVM). Free PVM, liberated from infected mouse lungs by means of this technique, is infectious and causes hemagglutination directly. The results of quantitative studies carried out in the high speed angle centrifuge indicate that the free virus is relatively small, with dimensions of the order of 40 millimicrons. When it is in combination with lung tissue particles, PVM appears to be a relatively large virus with minimal dimensions of the order of 140 millimicrons. Non-infectious virus particles, released from combination with lung tissue particles by heating, are similar to the infectious free virus in size. PMID- 19871598 TI - PROPERTIES OF PNEUMONIA VIRUS OF MICE (PVM) IN RELATION TO ITS STATE. AB - Additional evidence is presented that PVM is capable of combining firmly with lung tissue particles or erythrocytes from certain susceptible species. Release of the virus from such combination can be effected by treatment with alkali as well as by heating. Free virus expressed from infected lungs without grinding the tissues is infectious and causes hemagglutination when tested directly. The concentration of virus can be estimated more accurately by means of the hemagglutination technique than from the results of infectivity tests in mice. Present evidence indicates that PVM may occur in 4 different states and that in each state it manifests distinctive properties. PMID- 19871599 TI - THE EFFECT OF dl-METHIONINE, l-CYSTINE, AND dl-ISOLEUCINE ON THE UTILIZATION OF PARENTERALLY ADMINISTERED DOG HEMOGLOBIN : A SUGGESTION FOR DESIGNING THE COMPOSITION OF THE "IDEAL" PROTEIN DIGEST. AB - 1. Further observations on the utilization of parenterally administered dog hemoglobin show that oral supplements of dl-methionine and l-cystine improve the efficiency of utilization of hemoglobin N, while a fed supplement of dl isoleucine alone is without effect. 2. When N-isoleucine is added to a fed supplement of methionine or methionine and cystine, the utilization of parenterally given hemoglobin N is even better than with the sulfur-containing amino acids alone. 3. A suggested approach to the problem of designing the quantitatively "ideal" amino acid mixture lies in the definition of what may be called total organism-amino acid patterns of rat, dog, man, etc. These may vary considerably not only at different developmental stages in a given species, but also certainly from one species to another. 4. Further attempts to detect globin in the peripheral circulation have pointed to the need for a highly specific procedure such as that an immunologic method may offer. 5. Reduced hemin in dog plasma migrates with alpha(1)-globulin and albumin in veronal buffer at pH 8.5 and the colored zones give strong hemochromogen absorption bands. PMID- 19871600 TI - DISINFECTION OF CLOUDS OF MENINGOPNEUMONITIS AND PSITTACOSIS VIRUSES WITH TRIETHYLENE GLYCOL VAPOR. AB - 1. Triethylene glycol in excess of saturation, introduced as a vapor into a cloud chamber in which a dynamic cloud of either meningopneumonitis virus or psittacosis virus was developed simultaneously with, or in most instances subsequently to, the glycol cloud, induced distinct reduction in concentration of air-home virus, as measured both by cloud sampling in capillary impingers and by exposure of mice to the cloud. The relative humidity in the chamber was held between 35 and about 60 per cent. 2. Reduction of virus concentration in samplers, in glycol runs as compared with controls, ranged from 0 to 93 per cent (average, 62 per cent). 3. Reduction of infective response in mice, based on counts of focal lesions on lung surfaces, ranged from 55 to 98 per cent (average 73 per cent). PMID- 19871601 TI - STUDIES ON SPREADING FACTORS : I. THE IMPORTANCE OF MECHANICAL FACTORS IN HYALURONIDASE ACTION IN SKIN. AB - The spreading response induced by intradermal administration of hyaluronidase is influenced not only by enzyme concentration, but also by the volume and pressure of the injection. These pressure-volume factors influence the rate of spreading and determine the final area of spreading. When a constant volume is injected, the rate of spreading to the area determined by the volume of injection is a function of the enzyme concentration. These and other findings have led to the conclusion that hyaluronidase is an effective spreading agent only when the slow diffusion of enzyme in skin is accelerated by a localized increase of interstitial pressure and volume. These considerations of hyaluronidase action in skin have been utilized to explain the shape of the dosage-response curve of hyaluronidase spreading activity, and the differences in the spreading reactions between crude snake venoms and purified hyaluronidase. The significance of the findings as related to the role of hyaluronidase in bacterial invasiveness, and in the assay of S. F. are briefly discussed. PMID- 19871602 TI - THE EFFECT OF LIPIDS AND SERUM ALBUMIN ON BACTERIAL GROWTH. AB - Long chain fatty acids have been found to exhibit both inhibitory and stimulatory effects on the growth of tubercle bacilli and of a certain unidentified micrococcus culture. The toxicity of the fatty acids was much reduced or abolished by (a) esterification, even when the resulting product was a water soluble ester, and (b) addition of crystalline serum albumin to the culture medium; other proteins tested were inactive in this respect. Marked growth stimulation of the microorganisms studied was obtained when certain long chain fatty acids were added to the culture medium in the form of their water-soluble esters, or in admixture with adequate amounts of serum albumin. Abundant growth of the micrococcus resulted from the addition of oleic, linoleic, linolenic, or arachidonic acid (0.0001 to 0.001 per cent) to a mineral medium containing glucose as sole source of carbon; in the case of this microbial species, none of the other substances tested could substitute for these unsaturated fatty acids. Enhancement of growth of tubercle bacilli was obtained by adding to the medium 0.001 to 0.01 per cent of a variety of fatty acids (saturated or unsaturated) even in the absence of glucose or of any other readily available carbon compound. These results suggest that long chain fatty acids can affect the growth of different microbial species through different metabolic channels and that, in order to study the mechanism of these metabolic and growth reactions, it is essential to use the fatty acids under conditions where they cannot manifest their toxic properties. PMID- 19871603 TI - THE NUCLEIC ACID AND CARBOHYDRATE OF INFLUENZA VIRUS. AB - Both ribonucleic and desoxyribonucleic acids have been obtained from purified particles of PR8 influenza virus. These particles were also found by extraction with formamide to contain carbohydrate in addition to that of the nucleic acids. Carbohydrate-rich fractions, essentially devoid of nucleic acid, were obtained not only from the particles representing PR8 virus but from those of Lee influenza virus as well. The carbohydrate in each case appeared to be a polysaccharide composed of mannose, galactose, and glucosamine units. PMID- 19871604 TI - THE INACTIVATION OF PENICILLINS F, G, K, AND X BY HUMAN AND RABBIT SERUM. AB - 1. Penicillins F, G, K, and X were all inactivated by human and rabbit serum, but two qualitatively distinct mechanisms were apparently involved. 2. One was a slow inactivation of all four penicillins by a relatively thermostable serum component which was not demonstrably affected by heating for 60 minutes at 56 degrees C. (a) In both human and rabbit serum this general inactivation of penicillin behaved like a pseudo first order reaction, with a velocity constant of 0.05-0.07 for penicillin X, and 0.09-0.11 for penicillins F and G. (b) The percentage of penicillins F, G, and X inactivated per hour was independent of their concentration over the range 0.4 to 50 micrograms per cc., averaging 9.5, 10, and 6.5 per cent, respectively, in human serum, and 9,8.5, and 5 per cent in rabbit serum. (c) The rate of inactivation varied linearly with the concentration of the serum factor. (d) Penicillin X was consistently and significantly less susceptible to inactivation than any of the other penicillins. Although minor differences were observed between F and G, these were not consistent, and are of questionable significance. 3. Superimposed on this slow inactivation of penicillins F, G, K, and X by a thermostable serum component was a much faster inactivation observed only with penicillin K. (a) In both rabbit and human serum, the serum factor responsible for this inactivation was highly thermolabile, and was almost completely destroyed within 5 minutes at 56 degrees C., leaving only a thermostable component, not affected by further heating. (b) The inactivation of K by this thermolabile component was not a first order reaction, but varied with the concentration of both serum and penicillin. At high concentrations of K, the rate of inactivation due to the thermolabile factor was negligible, and penicillin K was destroyed no more rapidly than F, G, or X. The rate of inactivation increased as the concentration of penicillin was reduced. At penicillin K concentrations of 50, 10, 2, and 0.4 micrograms per cc., the hourly destruction in rabbit serum averaged 10, 16, 21, and 54 per cent. The corresponding figures in human serum were 10, 11, 14, and 54 per cent. The reservations entailed by the large serum error at the lower concentrations of penicillin are discussed in the text. 4. The temperature coefficient for the inactivation of penicillin K by fresh human or rabbit serum was 2.5 for each 10 degrees C. No significant inactivation was observed in 24 hours at 20 degrees C.; and this was true also of penicillins F, G, and X. 5. Heparinized plasma was just as active as serum, washed red blood cells had no effect, and the activity of whole blood was referable to its plasma content. 6. The nature of the serum factors responsible for these two types of penicillin inactivation are under present study. 7. The urinary excretion of penicillin is so rapid that the slow destruction of penicillins F, G, and X in the circulating blood as here described is of secondary significance therapeutically. It nevertheless must contribute to their rapid disappearance from the blood; and the fact that X is inactivated more slowly than either F or G could be reflected in higher and more sustained blood levels than are afforded by the latter two species. There are some reports that such is the case (15-17), and the following paper provides further evidence for the superiority of penicillin X in this respect over the other species so far studied. The serum inactivation of penicillin K, at a rate which increases as its concentration falls, should be reflected in significantly lower and more evanescent blood levels than are observed with penicillins F, G, or X. As will be discussed in the following paper, this has been found to be the case, and provides a simple explanation for its paradoxically low therapeutic activity in vivo (8-11). PMID- 19871605 TI - THE VARYING BLOOD LEVELS AFFORDED BY PENICILLINS F, G, K, AND X IN RABBITS AND MAN. AB - 1. In both man and rabbit, penicillin X provided higher and more sustained blood levels than did penicillins F or G similarly administered in equal dosage (0.6 mg. per kg.); while penicillin K gave lower and evanescent levels. (a) One hour after intramuscular injection, the blood levels in rabbits averaged 0.11, 0.18, 0.02, and 0.33 for F, G, K, and X, respectively; and levels of 0.1 mg. per kg. were sustained for 1, 1.4,0.5, and 2.1 hours, respectively. (b) In man, the blood levels of G, K, and X averaged 0.23, 0.16, and 0.37 mg. per kg. 1 hour after intramuscular injections at 0.6 mg. per kg., and 0.11, 0.02, and 0.15 mg. per kg. 1 hour after intravenous injection. (c) In man, a level of 0.1 microgram per cc. was sustained for 1.6, 1.2, and 2.3 hours after the intramuscular injection of G, K, and X, respectively, and for 1, 0.5, and 1.3 hours after their intravenous injection. 2. The total urinary recovery of penicillins F, G, and X varied between 68 and 100 per cent, averaging 61, 87, and 74 per cent, respectively, in rabbits. In man, the urinary recovery of G and X averaged 86 and 93 per cent, respectively. In sharp contrast, the urinary recovery of penicillin K averaged 33 per cent in seven rabbits and 28 per cent in six human volunteers. The major portion of the penicillin appeared in the first 30 to 60 minutes. This suggests a rapid inactivation of penicillin K in vivo. 3. The therapeutic significance of these data is discussed in the text, and in greater detail in the following paper. PMID- 19871606 TI - THE THERAPEUTIC ACTIVITY OF PENICILLINS F, G, K, AND X IN EXPERIMENTAL INFECTIONS WITH PNEUMOCOCCUS TYPE I AND STREPTOCOCCUS PYOGENES. AB - 1. The relative bactericidal activities of penicillins F, G, K, and X against Type I pneumococcus in vitro were 60, 100, 180, and 135. The corresponding activities against Streptococcus pyogenes, strain C-203, were 75, 100, 115, and 145, respectively. 2. The total curative doses (CD(50)) of penicillins F, G, K, and X in pneumococcal infections of white mice (ten injections at 3 hour intervals) were 4.6, 3.8, 20, and 2.4 mg. per kg., respectively, or relative activities of 83, 100, 19, and 160, referred to G as 100. 3. The corresponding curative doses in streptococcal infections of white mice were 2.6, 1.3, 14.0, and 0.5 mg. per kg., or relative activities of 50, 100, 9, and 260. 4. Penicillin K was therefore one-tenth as active in vivo as would be implied by its bactericidal activity in vitro. This probably reflects its rapid inactivation in vivo, evidenced by the low and evanescent blood levels observed in both rabbits and man, and the low urinary recovery of this species of penicillin. 5. Penicillin X was significantly more active therapeutically than its bactericidal activity in vitro would imply. This probably reflects its slower inactivation in vivo, evidenced by the somewhat higher and more prolonged blood levels afforded by this penicillin in comparison with penicillin G. Judged by the mouse infections with the strains here used, penicillin X is the penicillin of choice in the treatment of infections with pneumococcus Type I and hemolytic streptococci. 6. The curative dose of penicillin in streptococcal and pneumococcal infections paralleled the varying susceptibility of these organisms to penicillin in vitro. PMID- 19871607 TI - DESOXYCORTICOSTERONE ACETATE : THE POTENTIATION OF ITS ACTIVITY BY SODIUM CHLORIDE. AB - 1. Desoxycorticosterone acetate (DCA) and NaCl, in the dosage employed in normal rats, caused renal and cardiac hypertrophy, characteristic changes in the renal tubular epithelium, atrophic changes in the subcapsular zone of the adrenal cortex, and serum electrolyte changes characterized by a rise in sodium and fall in potassium. 2. In rats rendered nephritic with a rabbit anti-rat-kidney serum, the same regimen caused similar changes. In addition, DCA given concurrently with NaCl greatly intensified the nephritic process and gave rise to striking arterial hypertension. 3. A diet, virtually sodium-free, administered to normal and nephritic rats receiving daily injections of DCA abolished or reduced to a minimum the effects of this steroid; i.e., a liberal ingestion of NaCl was essential for the potentiation of the action of DCA. 4. The addition of KCl to the drinking water of rats receiving DCA and NaCl tended to correct the depression of the level of potassium in the serum, but had no effect upon the hypertension in nephritic animals nor upon the anatomical lesions. 5. The mechanism by which the sodium ion potentiates the activity of DCA has not been established. PMID- 19871609 TI - QUANTITATIVE STUDY OF COLLAGEN CONTENT IN EXPERIMENTAL CIRRHOSIS. AB - Quantitative determinations of collagen were carried out on rat livers showing cirrhosis due to p-dimethylaminoazobenzene and carbon tetrachloride. A twofold increase in collagen content occurred in cirrhosis due to p dimethylaminoazobenzene. The average total hepatic collagen as well as the per cent collagen content were doubled. The collagen content after 1(1/2) months of normal diet had fallen to normal levels. In cirrhosis due to carbon tetrachloride, the collagen content underwent about a fourfold increase. Partial reversal with significant decrease in collagen content occurred after stopping the carbon tetrachloride. The incomplete resorption of collagen in this group can be attributed to impaired hepatic regeneration following the prolonged administration of the compound. The chemical values for collagen parallel the quantitative evaluations of collagen content, based on microscopic examination of liver sections stained for reticulum. Deposition of collagen in hepatic cirrhosis is not necessarily an irreversible phenomenon. PMID- 19871608 TI - REACTIONS OF MONKEYS TO EXPERIMENTAL MIXED INFLUENZA AND STREPTOCOCCUS INFECTIONS : AN ANALYSIS OF THE RELATIVE ROLES OF HUMORAL AND CELLULAR IMMUNITY, WITH THE DESCRIPTION OF AN INTERCURRENT NEPHRITIC SYNDROME. AB - 1. The vital importance of the cellular defense forces in the resistance of the monkey to combined streptococcus and influenza virus infections has been demonstrated. 2. Some of the conditions prejudicial to the maintenance of an optimum cellular reserve in the infected animal have been revealed; viz., undernutrition, physical cold, intratracheal route of infection. 3. The potential threat exerted by latent foci of streptococci, and the importance, in relation to the combined infection with virus, of cellular and humoral immunity, together or separately, have been demonstrated. The essential role of optimum nutrition (notably as concerns the vitamin B complex, and folic acid specifically) in the prevention of disastrous illness from these infectious agents, individually or in combination, would seem to have been proven. 4. Signs of glomerular nephritis appeared in a significant number of monkeys receiving Streptococcus hemolyticus and influenza virus in sequence, followed by reinoculation or spontaneous reappearance of the streptococci. 5. Reinoculation of Streptococcus hemolyticus, group C, resulted in a prompt "booster" increase in the opsonic index. Virus instillation was followed by just as sudden a depression in this index. 6. Reinoculation failed to evoke either the granulocytosis or the leucopenia in monkeys which are characteristic effects of the streptococcus and the virus respectively when these agents are introduced for the first time by way of the nasal mucous membrane. 7. Simultaneous intranasal inoculation of influenza virus, type A, and Streptococcus hemolyticus, group C, in nutritionally normal Macaca mulatta failed to produce obvious signs of disease. In most of the animals, however, a streptococcus-induced leucocytosis followed by a delayed virus-induced granulopenia developed. 8. Inoculation of influenza virus followed in 4 to 17 days by streptococci produced obvious signs of disease in five of eleven animals which had become leucopenic as result of the action of the virus, and fatal streptococcal septicemia in two monkeys. 9. The development of signs of infection in previously healthy monkeys exposed to virus followed by streptococci confirms both the clinical and laboratory experience of other observers, that virus infection may predispose to secondary bacterial invasion, and, that at times, under unfavorable circumstances, the infection may become overwhelming. Although the complete mechanism of resistance is as yet not wholly clear, the depressant or inhibitory effect of the virus on both its cellular and humoral elements has been established. PMID- 19871610 TI - ANTIBODY FORMATION IN MEN FOLLOWING INJECTION OF FOUR TYPE-SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS. AB - 1. Random selections of the sera of trainees injected 2 months previously with the specific polysaccharides of Types I, II, V, and VII pneumococci contained quantities of antibody to Types I, II, and VII sufficient to account for the favorable results of the immunization procedure. 2. As in earlier studies, the levels of the antibody for the C polysaccharide remained relatively constant before and after the injections. 3. The serum from the preliminary bleedings often contained antibody to the Type VII polysaccharide. This remained relatively constant in a control group injected with saline. PMID- 19871611 TI - THE SIGNIFICANCE OF LESIONS IN PERIPHERAL GANGLIA IN CHIMPANZEE AND IN HUMAN POLIOMYELITIS. AB - 1. The peripheral ganglia of eighteen inoculated chimpanzees and thirteen uninoculated controls, and of eighteen fatal human poliomyelitis cases, were studied for histopathological evidence of the route of transmission of virus from the alimentary tract to the CNS. 2. Lesions thought to be characteristic of poliomyelitis in inoculated chimpanzees could not be sharply differentiated from lesions of unknown origin in uninoculated control animals. Moreover, although the inoculated animals as a group, in comparison with the control animals, had a greater number of infiltrative lesions in sympathetic as well as in sensory ganglia, it was not possible to make satisfactory correlations between the distribution of these lesions and the routes of inoculation. 3. In sharp contrast with chimpanzees, the celiac and stellate ganglia of the human poliomyelitis cases were free of any but insignificant infiltrative lesions. Lesions in human trigeminal and spinal sensory ganglia included neuronal damage as well as focal and perivascular inflitrative lesions, as is well known. In most ganglia, as in monkey and chimpanzee sensory ganglia, these were correlated in intensify with the degree of severity of lesions in the region of the CNS receiving their axons. This suggested that lesions in sensory ganglia probably resulted from spread of virus centrifugally from the CNS, in accord with considerable experimental evidence. 4. Two principal difficulties in the interpretation of histopathological findings in peripheral ganglia were revealed by this study. The first is that the specificity of lesions in sympathetic ganglia has not been established beyond doubt as being due to poliomyelitis. The second is that the presence of characteristic lesions in sensory ganglia does not, and cannot, reveal whether the virus reached the ganglia from the periphery or from the central nervous system, except in very early preparalytic stages or in exceptional cases of early arrest of virus spread and of lesion production. PMID- 19871612 TI - PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN. AB - Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive urinary nitrogen balance and a liberal output of blood proteins but there is always weight loss, however we may choose to explain this loss. These experiments touch on the complex problems of parenteral nutrition, experimental and clinical. PMID- 19871613 TI - ANEMIA AND HYPOPROTEINEMIA : WEIGHT MAINTENANCE EFFECTED BY FOOD PROTEINS BUT NOT BY MIXTURES OF PURE AMINO ACIDS. AB - Dogs with sustained anemia and hypoproteinemia due to bleeding and a continuing low protein or protein-free diet with abundant iron are used to test the value of food proteins as contrasted with mixtures of pure amino acids. The stimulus of double depletion (anemia and hypoproteinemia) drives the body to use every source of protein and all protein-building materials with the utmost conservation. Raiding of body tissue protein to produce plasma protein and hemoglobin is a factor when protein-building factors are supplied in small amounts. In this severe test (double depletion) the good food proteins in adequate amounts are able to maintain body weight, a strongly positive nitrogen balance, and produce considerable amounts of new hemoglobin and plasma protein. Casein, lactalbumin, whole egg protein, liver protein are all adequate in amounts of 150 to 250 gm. protein per week. Under comparable conditions mixtures of pure amino acids (essential for growth) do produce large amounts of new hemoglobin and plasma protein and a positive nitrogen balance but do not maintain body weight. The loss of weight is conspicuous even with large amounts of amino acids (200 to 300 gm. protein equivalent per week). Methionine, threonine, and phenylalanine are related to nitrogen conservation in growth mixtures of essential amino acids (Paper I) but when these three are given together they have little influence on the doubly depleted dog (Table 3). Some unidentified substance or compound present in certain proteins but absent in mixtures of the essential amino acids may be responsible for these differences in the response of the doubly depleted dog. PMID- 19871614 TI - RAIDING OF BODY TISSUE PROTEIN TO FORM PLASMA PROTEIN AND HEMOGLOBIN : WHAT IS PREMORTAL RISE OF URINARY NITROGEN? AB - Dogs with sustained anemia and hypoproteinemia due to bleeding and a continuing low protein or protein-free diet with abundant iron will continue to produce much new hemoglobin and plasma protein for many weeks. The stimulus of double depletion (anemia and hypoproteinemia) leads to raiding of body and tissue protein to fill the demand for new hemoglobin and plasma protein. The blood proteins in these experiments take priority over the organ and tissue proteins. This is another illustration of the "ebb and flow" or dynamic equilibrium between organ or tissue protein and blood proteins. The average dog cannot tolerate this drain of double depletion for more than 7 to 11 weeks and during this time may lose 30 to 40 per cent of body weight. Some dogs are much more resistant to this raiding than others. Some dogs show a high blood protein output during every week up to the danger point. With the largest blood protein output one usually observes the most rapid weight loss. For every kilogram of weight loss we observe 50 to 140 gm. blood protein output. The weekly blood protein production ranges from 40 to 66 gm. These experiments make heavy demands on the body protein and we expected to record a "premortal rise" in urinary nitrogen. No such observations are noted, rather a most frugal use of all protein and minimum figures for urinary nitrogen. We suspect that "premortal rise" in many experiments means a terminal infection with the related catabolism of tissue protein and high urinary nitrogen. PMID- 19871615 TI - ACTIVE IMMUNITY TO POLIOMYELITIS IN CHIMPANZEES FOLLOWING SUBCLINICAL INFECTION. AB - This report is concerned with the production of subclinical poliomyelitis in the chimpanzee, and immunity to such infection. Subclinical infection was produced in eight chimpanzees by the administration of virus orally or intracutaneously, and was measured by the production of a virus carrier state and the development of neutralizing antibodies. Immunity was tested by attempting to induce the carrier state again by a challenge dose of virus by the same routes. With an homologous strain as the challenge virus, immunity as defined here was produced in each of four chimpanzees tested. Neutralizing antibodies to the homologous strain were present about 1 month following the first exposure to virus by either the oral or cutaneous route. In another group of two chimpanzees, one developed neutralizing antibodies and immunity to heterologous strains, and one did not. PMID- 19871616 TI - AN INACTIVE PRECURSOR OF STREPTOCOCCAL PROTEINASE. AB - 1. Streptococcal proteinase is derived from an inactive precursor found in culture filtrates of proteinase-producing streptococci. 2. The precursor can be converted into the proteinase by low concentrations of trypsin but not by chymotrypsin. 3. In cultures grown in suitable media the conversion of precursor to proteinase is effected autocatalytically. This reaction occurs under reducing conditions and is initiated by active proteinase present in low concentrations with the precursor. 4. The autocatalytic reaction is suppressed or retarded by conditions which decrease the activity of the proteinase, e.g. by growing cultures at 22 degrees C. instead of at 37 degrees C. or by growing them under markedly aerobic conditions. It is also retarded in the presence of casein. PMID- 19871617 TI - AN EXPERIMENTAL STUDY OF SHOCK WAVES RESULTING FROM THE IMPACT OF HIGH VELOCITY MISSILES ON ANIMAL TISSUES. AB - The spark shadowgram method of studying shock waves is described. It has been used to investigate the properties of such waves produced by the impact of a high velocity missile on the surface of water. The method can be adapted for study of behavior of shock waves in tissue by placing the tissue on a water surface or immersing it in water. Spark shadowgrams then reveal waves passing from tissue to water or reflected from tissue surfaces. Reflection and transmission of shock waves from muscle, liver, stomach, and intestinal wall are compared with reflection from non-living surfaces such as gelatin gel, steel, plexiglas, cork, and air. Because of its heterogeneous structure, waves transmitted by tissue are dispersed and appear as a series of wavelets. When the accoustical impedance (density x wave velocity) of a medium is less than that in which the wave is moving, reflection will occur with inversion of the wave; i.e., a high pressure wave will become a low pressure wave. This inversion occurs at an air surface and is illustrated by shadowgrams of reflection from stomach wall, from a segment of colon filled with gas, and from air-filled rubber balloons. Bone (human skull and beef ribs) shows good reflection and some transmission of shock waves. When steel is directly hit by a missile, clearly visible elastic waves pass from metal to water, but a similar direct hit on bone does not result in elastic waves strong enough to be detected by a spark shadowgram. PMID- 19871618 TI - MODE OF ACTION OF STREPTOMYCIN ON TYPE b H. INFLUENZAE : I. ORIGIN OF RESISTANT ORGANISMS. AB - 1. Of fourteen patients with type b H. influenzae infections treated with streptomycin alone ten recovered promptly; in three of the four remaining cases failure was proved to be due to emergence of resistance of the organisms to streptomycin. 2. The rapid development of resistance to 1000 units of streptomycin per cc. during treatment argues against metabolic adaptation of the bacteria. 3. Careful study of large samples of initial bacterial populations shows resistant members in all ten strains examined. The incidence varies from 1 in 1.1 billion to 1 in 13.8 billion organisms. 4. The proportion of resistant members is not significantly higher, before treatment, in patients who do poorly than in those who respond promptly. 5. The results indicate that emergence of resistance is the result of a selective process; after elimination of sensitive members the very few resistant ones, apparently present in all strains, make up most or all of the population in the cultures taken after commencement of treatment. 6. The survival of organisms which can grow in high concentrations of streptomycin, either in patients or in vitro, is influenced more by the size of the bacterial population than by any other known factor. 7. Since the bacterial population is relatively small in those patients with mild or moderately severe infections the likelihood of a significant number of very resistant members being present is remote. 8. The traits responsible for resistance of the organisms are apparently inherited: (a) The resistant state of one strain has been transmitted in vitro without change in degree through over one hundred subcultures in the absence of streptomycin, (b) Persistence of resistant organisms in the nasopharynx of one patient during a one year period raises an important public health problem. PMID- 19871619 TI - NORMAL STRUCTURE AND DEGENERATIVE CHANGES OF THE CYTOPLASM OF LIVER CELLS AND OF TUMOR CELLS DERIVED FROM THEM. AB - Discrete bodies which may be designated cytochondria occupy the greater part of the cytoplasm of liver cells. A part, but not all, of these bodies have the characteristics of mitochondria. They consist of a rim which stains deeply and a central part which stains faintly or remains unstained. In liver cells about portal spaces, in foci of regeneration, and in tumor cells the rims of the cytochondria stain with basic dyes and contain ribonucleic acid or related substances. With increasing accumulation of basophile substances about cytochondria as the central veins are approached, these bodies aggregate to form clumps or orient themselves with palisade-like arrangment in two rows just within the margins of the liver cell columns. With aggregation of the cytochondria that are surrounded by basophile material, other cytochondria in the same cells are devoid of this material and wholly acidophile. With chromatolysis (disappearance of basophile substance) caused by dimethylaminoazobeiizene (butter yellow) cytochondria lose their peripheral basophilia and stain only with acid dyes. When ribonucleic acid is removed from fixed liver tissue by ribonuclease, cytochondria lose their affinity for basic stains and become acidophile. Of the cytochondria that are surrounded by ribonucleic acid or related substances part have the characteristics of mitochondria. Under the influence of butter yellow cytochondria may become greatly swollen and intensely acidophile in the center though they retain their basophile rim. These swollen bodies in part at least have the reactions of mitochondria. In tumor cells of hepatomas mitochondria are smaller and less abundant than in parenchymatous cells of the liver, and accompanying them are bodies of similar size which do not react as mitochondria. The cytochondria of hepatomas produced by butter yellow undergo acidophile degeneration similar to that of liver cells and form swollen spherical bodies with basophile rims. With partial or complete loss of basophile substance, these altered cytochondria may form conspicuous cell inclusions. PMID- 19871620 TI - THE EFFECT OF ULTRAVIOLET IRRADIATION ON VARIOUS PROPERTIES OF INFLUENZA VIRUSES. AB - The effect of ultraviolet irradiation on various properties of the influenza viruses Types A and B has been analyzed. The studies involved propagation and interference in the allantoic sac of the chick embryo, inhibition of embryonic development, toxicity for white mice, hemagglutination including the adsorption elution mechanism, immunizing capacity for mice and, finally, complement fixation activities in the presence of antibodies to the 600S antigen (human convalescent and postvaccination sera) and the 30S antigen (convalescent sera only). It has been shown that the various activities of the influenza viruses were affected by irradiation at different rates, indicating that they are based, at least in part, on different constituents of the virus particle. On account of these differences in the susceptibility of the various properties to ultraviolet light it was possible (a) to differentiate between the interference phenomenon as observed in the allantoic sac, and the development of non-agglutinability in red cells by either homologous or heterologous fresh virus, and (b) to separate individual steps involved in the mechanism of infection of susceptible host cells. The implications of these findings are discussed. PMID- 19871621 TI - IMPAIRMENT OF ANTIBODY RESPONSE IN PYRIDOXINE-DEFICIENT RATS. AB - Striking impairment of the antibody response to sheep erythrocytes was found in pyridoxine-deficient rats. Deficiencies in the three other B factors required by the rat, and low protein feeding, having effects on body weight comparable to pyridoxine deficiency, failed to influence the antibody response studied. Confirming previous observations, a striking loss of thymic and lymphoid tissue occurred in the pyridoxine-deficient animals. A marked deficit in thymus weight also resulted from the feeding of a diet low in thiamin. Histologically, however, lymphoid atrophy was less pronounced in thiamin-deficient rats than in those deprived of pyridoxine. PMID- 19871622 TI - STUDIES ON GLYCOGEN NEPHROSIS IN ALLOXAN-TREATED DIABETIC RATS. AB - Two hundred and seven albino rats were injected subcutaneously with alloxan in doses varying from 140 to 200 mg. per cent per kilo of body weight. Fifty-nine animals which developed hyperglycemia (blood sugar levels above 150 mg. per cent) were observed for periods from 5 days to 32 weeks. Postmortem examination of the kidneys of these diabetic animals revealed glycogen deposition in the loops of Henle and convoluted tubules in 26 rats or 44 per cent. Glycogen could not be demonstrated in the glomeruli. Within the time limits of this experiment (32 weeks) no intercapillary glomerulosclerosis was observed. The following facts were revealed regarding glycogen nephrosis in alloxan diabetes: (a) Its appearance in the kidneys of the diabetic rats depended solely upon the terminal blood sugar levels of these animals. A value of 350 mg. per cent was the critical level, above which glycogen nephrosis was almost invariably demonstrable. With terminal levels below 300 mg. per cent no glycogen nephrosis was found. (b) No relationship existed between the postmortem finding of glycogen nephrosis and the initial blood sugar level, or the maximum height of the hyperglycemia attained by individual rats. (c) The results suggest that glycogen nephrosis is a reversible lesion. PMID- 19871623 TI - A MANOMETRIC METHOD FOR MEASURING THE ACTIVITY OF THE CL. WELCHII LECITHINASE AND A DESCRIPTION OF CERTAIN PROPERTIES OF THIS ENZYME. AB - A manometric method has been described for measurement of the activity of Cl. welchii lecithinase. The method depends on displacement of carbon dioxide from a bicarbonate-carbon dioxide-buffered medium by the phosphorylcholine liberated during the enzymatic hydrolysis. PMID- 19871624 TI - A STUDY OF THE COMPETITION OF LECITHIN AND ANTITOXIN FOR CL. WELCHII LECITHINASE. AB - Lecithin has been found to interfere with the combining reaction of Cl. welchii alpha toxin (lecithinase) and its antitoxin. If the lecithinase is first brought into contact with lecithin, and the antitoxin is then added, the antitoxin fails to stop the enzymatic reaction, but gradually decelerates it. If the lecithinase is brought into contact with both lecithin and antitoxin at the same instant, it appears to combine in part with each, and the enzymatic process takes place at a reduced rate, which gradually declines further. If the lecithinase is first brought into contact with antitoxin, before the lecithin is added, the enzymatic reaction is completely inhibited. This ability of lecithin to inhibit the antitoxin-toxin combination cannot be explained adequately as a non-specific coating of the toxin-enzyme by the lecithin. It is rather suggested that lecithin and antitoxin compete specifically for combination with the same regions on the enzyme molecule. Lecithin has similarly been found to interfere with the combination of Crotalus terrificus venom and its antiserum. The above findings provide a partial explanation for the lack of effectiveness of antitoxin when given late in the course of Cl. welchii infection. PMID- 19871625 TI - EPIDEMIC DIARRHEAL DISEASE OF SUCKLING MICE : I. MANIFESTATIONS, EPIDEMIOLOGY, AND ATTEMPTS TO TRANSMIT THE DISEASE. AB - 1. The disease was almost certainly infectious. 2. Its eradication offered much greater practical difficulties than are presented by certain other infections of mice. 3. A definite tendency toward greater susceptibility in first litters as contrasted with subsequent ones was noted. 4. Advantage could be taken of this increasing resistance to keep the infected colony in efficient production, but accidental loss of the stock prevented the continuation of the plan for a time sufficient to exclude possible failure due to seasonal variation. 5. Multiple etiologies may well have existed even within this circumscribed outbreak. 6. Experimental investigation of the condition offers extraordinary difficulties but its thorough understanding promises to bring new light to basic problems of disease. PMID- 19871626 TI - AN EPIDEMIC DIARRHEAL DISEASE OF SUCKLING MICE : II. INCLUSIONS IN THE INTESTINAL EPITHELIAL CELLS. AB - Intranuclear inclusions were found in 75 per cent of young mice suffering from a spontaneous diarrheal disease. They were confined to the epithelial cells of the small intestine, and to the intestinal and mesenteric lymphadenoid tissue. They were seen only between the 10th and 15th days after birth, in apparently healthy control mice of the same age group, they were found in only two of thirty-six animals (5.5 per cent) and these were in mice from the same room and stock as the diseased animals. Nursing mice experimentally infected by feeding unfiltered diarrheal feces, also showed inclusion bodies from the 10th to the 14th day inclusive. The inclusions were not present during a corresponding age period, in the healthy stock used for these experiments. Inclusions have also been found in the cytoplasm of the intestinal epithelial cells of young mice but without any significant relation to the disease under study. No conclusions as to their nature are warranted at this time. PMID- 19871627 TI - RELATION OF THE SIZE OF THE INOCULUM AND THE AGE OF THE INFECTION TO THE CURATIVE DOSE OF PENICILLIN IN EXPERIMENTAL SYPHILIS, WITH PARTICULAR REFERENCE TO THE FEASIBILITY OF ITS PROPHYLACTIC USE. AB - 1. A relatively small amount of penicillin sufficed to abort syphilitic infection in rabbits when administered during the incubation period of the disease. 2. The abortive dose, given as a single intramuscular injection in oil and beeswax, varied with the age of the infection. (a) With a fixed intratesticular inoculum, the amount of penicillin necessary to prevent infection in half the animals remained at a constant level for 4 days. By the end of the 2nd week more than seven times this dosage was needed; and by the 6th week, after the chancre had appeared, more than thirty times the amount was needed to obtain the same result. The progressive increase in the abortive dose of penicillin with the passage of time probably reflects the interim multiplication of organisms. (b) Qualitatively similar results were obtained in rabbits inoculated intracutaneously. 3. The abortive dose varied also with the size of the inoculum. In animals inoculated intracutaneously with 20, 2,000, and 200,000 spirochetes, and treated 4 days later, it required 200, 500, and 3,500 units per kg., respectively, to protect half the animals, and the corresponding PD(90) dosages were 500, 2,000, and 16,000 units per kg. 4. The present observations, indicating the ease of aborting experimental rabbit syphilis during the incubation period by a single injection of penicillin, are perhaps applicable to the prevention of the disease in man. 5. Asymptomatic infections were rare in animals receiving inadequate doses of penicillin during the incubation period. Sixty-four of sixty-five such animals developed darkfield-positive lesions at the inoculated site. In animals treated 6 weeks after inoculation, however, after the development of lesions, inadequate treatment was usually manifested by an asymptomatic redissemination of organisms demonstrable only by lymph node transfer. The difference in the two groups probably reflects the beginning development of immunity in the rabbits treated 6 weeks after inoculation. 6. As suggested by Rake and Dunham (11), the treatment of animals during the incubation period permits a rapid assay of antisyphilitic agents, and one which requires only small amounts of material. Possible limitations of the method are discussed in the text. PMID- 19871628 TI - STUDIES ON STREPTOCOCCAL FIBRINOLYSIS : V. THE IN VITRO PRODUCTION OF FIBRINOLYSIN BY VARIOUS GROUPS AND TYPES OF BETA HEMOLYTIC STREPTOCOCCI; RELATIONSHIP TO ANTIFIBRINOLYSIN PRODUCTION. AB - A method for the measurement of fibrinolysin production by beta hemolytic streptococci is described. The test was shown to be highly accurate in that repeated determinations showed only small variations. A study of 766 strains of beta hemolytic streptococci isolated from normal soldiers and patients with respiratory disease showed that fibrinolysin was produced by Lancefield groups A, C, and G, and, in addition, by a few strains of groups B and F. Group A streptococci produced more fibrinolysin on the average than the other groups. The median titers were 117 for group A, 61 for group C, and 20 for group G streptococci. In a study of 388 typed group A streptococci from different subjects the fibrinolytic capacity of an organism was shown to be related to the serological type. The importance of this observation in relation to the role of streptococcal fibrinolysis in infections is discussed. Finally, it was demonstrated that strains of streptococci which produced large amounts of fibrinolysin were capable of stimulating antifibrinolysin formation in patients whereas strains that produced small amounts only occasionally caused antibody formation. PMID- 19871629 TI - THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : III. THE TUMORS ELICITED FROM GASTRIC EPITHELIUM. AB - Epithelial tumors have been readily obtained by the implantation of embryo stomach tissue together with olive oil containing methylcholanthrene (with or without Scharlach R) in adult mice of homologous strain. The implanted tissue from the squamous portion of the stomach rapidly encysted the oil, and benign and malignant papillomas and squamous cell carcinomas soon arose from the stratified squamous lining of the cysts. Bits of the glandular portion of the stomach also formed cysts, but the gland cells underwent metaplasia in response to the carcinogen, altering first to transitional epithelium and then to a stratified squamous layer. So swiftly did these changes take place that nearly all of the tumors took origin from epithelium that had already become stratified and squamous, and the growths themselves were of this type. A single transitional cell carcinoma and an adenoacanthoma were procured, but no adenocarcinomas; nor did any benign papillomas develop, though they often resulted from the action of methylcholanthrene on the squamous portion of the embryo stomach. Search failed to disclose any distinctive precancerous changes in the gastric tissue. Five of the cancers were transplanted and they grew in every host. No tumors arose from any of the numerous control implants. Those consisting of glandular tissue formed cysts lined partly with columnar epithelium secreting mucus and partly with tubular glands equipped with chief and parietal cells in good condition. Pepsin and rennin were found in the fluid contained in these cysts, but no free hydrochloric acid. The enzymes were present also when the cysts contained methylcholanthrene and the glands had not yet been wholly replaced by metaplastic epithelium. The tumors appeared months sooner than when methylcholanthrene is injected into the stomach of adult animals or given by mouth; some of them were well established after 5 or 6 weeks. They arose regularly when the requisite experimental conditions were provided. The utilization of transplanted embryo tissue provides a means whereby gastric tumors free from bacterial infection can be procured swiftly and easily. PMID- 19871630 TI - THE METABOLISM OF AMINO ACIDS AND CASEIN DIGEST IN PHLORHIZINIZED DOGS. AB - When solutions of sugar-forming amino acids are given parenterally or orally to phlorhizinized dogs, extra sugar and nitrogen are excreted in the urine. The route of administration does not influence the way in which the amino acids are metabolized. 89 percent of the expected sugar was recovered when the acids were fed and 81 per cent when the acids were administered parenterally. Casein digests are metabolized like the amino acids with extra sugar and nitrogen excreted in the urine. When casein digest is given orally there is an average conversion into sugar of 53 per cent, as compared with 56 per cent intravenously. Solutions of amino acids or casein digests are readily available sources to the body of nitrogen and carbohydrate. PMID- 19871631 TI - THE OCCURRENCE DURING ACUTE INFECTIONS OF A PROTEIN NOT NORMALLY PRESENT IN THE BLOOD : IV. CRYSTALLIZATION OF THE C-REACTIVE PROTEIN. AB - A procedure is described for the isolation and crystallization from human serous fluids of the C-reactive protein, a substance which appears in the blood especially in the early phase of certain acute infectious diseases. Immunological studies confirm earlier work in showing that the protein is highly antigenic and serologically specific, and demonstrate that crystallization of the protein effectively separates it from normal serum proteins. PMID- 19871632 TI - STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : VI. THE DETOXIFICATION OF SHIGELLA PARADYSENTERIAE BY MEANS OF PERIODIC ACID. AB - A method for detoxifying Type Z and sp. Newcastle Sh. paradysenteriae (Flexner) has been described. This procedure involves exposing the bacilli at pH 5.0 to 0.01 M periodic acid. Microorganisms treated with this reagent for an appropriate time interval lose approximately 90 per cent of their toxicity, yet they are capable of eliciting in experimental animals antibodies effective against the unaltered organisms. PMID- 19871633 TI - ELECTROPHORETIC STUDY OF ANTIVIRAL SERA. AB - 1. Sera of animals immunized against Japanese B encephalitis, Venezuelan equine encephalomyelitis, and Western equine encephalomyelitis viruses were fractionated by electrophoresis. 2. Electrophoretic patterns of rabbit sera before and after immunization against Japanese B virus showed no consistent change traceable to antibody formation. 3. To determine the antibody content, the electrophoretic fractions of the respective sera were mixed in varying dilutions with infected mouse brain suspensions, and the neutralizing titers of the fractions were compared. 4. In all instances serum fractions containing gamma-globulin were protective, whereas in no case did serum albumin show any virus-neutralizing activity. The Japanese B encephalitis antibody appeared to be associated entirely with the gamma-globulin. The Venezuelan and Western equine encephalomyelitis antibodies were associated with the beta- and gamma-globulins and probably possessed an average electrophoretic mobility between that of beta- and gamma globulins. 5. Normal rabbit serum similarly separated electrophoretically showed no neutralizing properties. 6. Chickens, whose electrophoretic serum pattern is markedly different from that of rabbits, were also immunized against the Japanese B encephalitis virus. Their antisera were electrophoretically fractionated and similarly subjected to neutralization tests. The specific neutralizing capacity of chicken serum was considerably lower than that of rabbit serum and no neutralizing activity was found in the fractions containing the faster moving components. The antibody appeared to be associated with component 4 which had a mobility of approximately 2.3 x 10(-5) cm.(2)/volt/sec. PMID- 19871634 TI - THE ANTIBACTERIAL PROPERTIES OF SULFUR. AB - 1. Saturated solutions of sulfur in alcohol (alcohol-sulfur) when diluted with broth are inhibitory to the growth of various Gram-positive bacteria and to C. hominis. By an arbitrary method of unitage with S. aureus as the test organism, our alcohol-sulfur contains 1,600 to 2,000 units per cc. and one unit contains between 0.24 and 0.34 gamma sulfur. The activity of a preparation is in general directly proportional to its sulfur content. 2. Solutions of sulfur in carbowax (carbowax-sulfur) when diluted with broth are likewise inhibitory to the growth of various Gram-positive bacteria and to C. hominis. When S. aureus is used as test organism, 1 unit contains between 0.1 and 0.2 gamma sulfur. The activity of these preparations is also in general directly proportional to their sulfur content. 3. Carbowax-sulfur when incorporated in agar in 1-500 to 1-2,000 dilution inhibits the growth of various Gram-positive aerobic and anaerobic bacteria, C. hominis, and certain dermatophytes. 4. Our experiments appear to show that both alcohol-sulfur and carbowax-sulfur owe their inhibitory properties to the sulfur particles that are dispersed throughout the medium when these sulfur preparations are diluted with broth. The inhibitory effect of these particles may or may not be due to a combination of the sulfur particles with substances in the medium in which they are suspended. 5. Evidence suggests that the activity of both alcohol-sulfur and carbowax-sulfur is due to sulfur in the same form. The inhibitory effect is characterized by prolonged bacteriostasis with similar activity over a wide range of dilutions. There is no evidence of true bactericidal action even with the highest concentrations used. PMID- 19871635 TI - THE ANTIRICKETTSIAL EFFECT OF THIONINE DYES : I. THE USE OF METHYLENE BLUE AND TOLUIDINE BLUE TO COMBAT EXPERIMENTAL TSUTSUGAMUSHI DISEASE (SCRUB TYPHUS). AB - Methylene blue (MB) and toluidine blue (TB) when administered in maximum tolerated oral doses to mice and to cotton rats are highly effective in preventing the usual lethal outcome of intraperitoneally induced infections with R. orientalis. This activity is manifest even when dye administration is delayed until a systemic infection has been well established. Methylene blue is also effective in cerebral infections in mice. The toxicity of MB, however, limits parenteral (subcutaneous) administration of the dye to dosage levels which are much less effective than the maximum tolerated oral levels. The inability of mice to tolerate an adequately effective parenteral dose of MB suggests that the properties of the dye responsible for its toxicity may be separated from those upon which its antirickettsial effect depends. The relationship between the response of mice to oral treatment with MB and such factors as the size of the infecting dose and the times of initiation and of withdrawal of treatment may be summarized as follows: 1. With a constant infecting dose, the time of initiation of treatment largely determines the degree of therapeutic effect. 2. The interval after infection beyond which further treatment does not increase the survival rate depends not upon the previous duration of treatment but upon the size of the infecting dose. Paradoxically, treatment can be discontinued sooner after a massive infecting dose than after a smaller one. PMID- 19871636 TI - INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS : II. IN VITRO STUDIES WITH THE VIRUSES OF WESTERN AND EASTERN EQUINE ENCEPHALOMYELITIS, ST. LOUIS ENCEPHALITIS, POLIOMYELITIS (LANSING), AND RABIES. AB - 1. Experimental neurotropic virus infections previously shown to be altered by ether anesthesia are caused by viruses destroyed in vitro by anesthetic ether; this group includes the viruses of Eastern equine encephalomyelitis, Western equine encephalomyelitis, and St. Louis encephalitis. 2. Experimental neurotropic virus infections which were not altered by ether anesthesia are caused by viruses which are refractory to the in vitro virucidal activity of even large amounts of anesthetic ether; this group includes the viruses of poliomyelitis (Lansing) and rabies. 3. Quantitative studies of the in vitro virucidal activity of ether indicate that concentrations of this anesthetic within the range found in central nervous system tissues of anesthetized animals possess no virucidal activity. 4. The lowest concentration of ether possessing significant virucidal capacity is more than fifteen times the maximum concentration of the anesthetic tolerated by the experimental animal. 5. Concentrations of ether 50 to 100 times the maximum amount tolerated by the anesthetized animal are capable of destroying large amounts of susceptible viruses, the average lethal dose (LD(50)) being reduced more than 5 log units. 6. On the basis of the studies presented in this report, it cannot be concluded that direct virucidal activity of ether is not the underlying mechanism of the inhibition by anesthesia of certain experimental neurotropic virus infections. Indirect inhibition of the virus by the anesthetic through an alteration in the metabolism of either the host cell or the host animal as a whole appears at this point to be a more likely possibility. PMID- 19871637 TI - HISTOLOGICAL AND SEROLOGICAL SEQUENCES IN EXPERIMENTAL HYPERSENSITIVITY. AB - 1. Groups of normal rabbits were given, single intravenous injections of foreign proteins in doses of 1 gm. per kilo, bled at regular intervals for serologic studies, and sacrificed after varying lengths of time for pathological studies. The protein solutions used were of crystallized bovine serum albumin, bovine serum gamma globulin, and bovine serum. The experiments were planned, first, to correlate the sequence of pathological and immunological changes, and second, to compare the responses to two chemically and immunologically distinct plasma protein fractions and to the whole serum of the same species. 2. (a) The principal pathological lesions in rabbits given bovine serum were similar to those which have been previously observed following, the injection of horse serum and were characterized by widely dispersed but segmental acute inflammatory lesions of the arteries. These lesions were at their height 2 weeks after injection and showed marked repair at 4 weeks. (b) Crystallized bovine serum albumin produced lesions almost exclusively confined to the arteries which were at their height at 2 weeks, were healing at 3, and healed by 4 weeks. The lesions were less numerous and less intense than in animals given whole serum and were only found in some of the animals. (c) Bovine serum gamma globulin elicited quite different histologic sequences. The most striking lesions involved the glomeruli of the kidneys, and to a lesser degree, the heart. Lesions in the liver and joints were present but less conspicuous, and arterial lesions were rare and slight in degree. The lesions not only differed from those in rabbits given albumin in distribution but in timing, since they were most widespread and acute at 1 week and were healing at 2 weeks after injection. Moreover, lesions were observed in almost every animal. 3. Results of immunological studies were consistent with the interpretation that the pathological lesions were due to an antigen-antibody reaction in the tissues, as shown by the following: (a) Acute lesions were only observed when antigen was present and before antibody appeared in the circulation. (b) Healing of lesions was only observed (with one exception) when antigen had almost or completely disappeared from the circulation, usually with the appearance of antibody. (c) There was a correlation between the rapidity of evolution of the lesions and the rapidity with which the antigen disappeared from the circulation. (d) There was a rough correlation between the proportion of animals showing lesions and the proportion developing antibodies after the injection of a particular protein solution. PMID- 19871638 TI - A STUDY OF THE INHIBITION OF STREPTOCOCCAL PROTEINASE BY SERA OF NORMAL AND IMMUNE ANIMALS AND OF PATIENTS INFECTED WITH GROUP A HEMOLYTIC STREPTOCOCCI. AB - Antiproteinase sera were prepared by immunizing horses with filtrates from a selected strain of group A streptococcus. This strain, which produced high titred proteinase but no erythrogenic toxin, was selected from forty-two strains of group A streptococci which produced varying amounts of proteinase. A few strains belonging to groups B, C, and G were also tested; they were all proteinase negative. Methods are described for titrating streptococcal proteinase in crude culture filtrates and for measuring the antiproteinase activity of serum. The antiproteinase titres of sera from immunized horses ranged from 125 units to 1,000 units per cc. in contrast to the low titres of normal horse sera, only 5 per cent of which had titres as high as 10 to 30 units per cc. The available evidence suggests that the antiproteinase activity of immune sera is dependent on the action of specific antibody for streptococcal proteinase. Patients infected with group A streptococci do not develop high anti-proteinase titres. There appears to be no correlation between the occurrence of rheumatic fever and the antiproteinase titre of the patient's serum. PMID- 19871639 TI - MODE OF ACTION OF STREPTOMYCIN ON TYPE b HEMOPHILUS INFLUENZAE : II. NATURE OF RESISTANT VARIANTS. AB - In all of ten strains of H. influenzae examined prior to exposure to streptomycin a very small fraction of the bacteria formed colonies in the presence of 1,000 units of streptomycin per cc. These variant organisms possess the characteristics of bacterial mutants. 1. Different independent cultures of the same strain on different occasions, and even cultures seeded in a single test with the same inoculum, show marked variation in prevalence of resistant variants in populations of comparable size. This variation is just as great in genetically homogeneous culture sources as in heterogeneous sources. Evidence is presented for the continuous random occurrence of these resistant organisms. 2. The rate of occurrence of the resistant members is not significantly different for the ten strains studied; it varies from 2.6 x 10(-11) to 7.0 x 10(-11) per bacterium per bacterial generation. The results of five different tests on the same strain show comparable variation, 2.9 x 10(-11) to 5.3 x 10(-11). This low rate contributes evidence consistent with the mutation hypothesis. 3. Variants exhibiting resistance to 1,000 units of streptomycin per cc. transmit this trait unchanged in degree through many generations. The results obtained after twelve or more subcultures in streptomycin-free media suggest that in a portion of the colonies resistant to streptomycin an additional trait, differing from those exhibited by the parent culture, is associated; the nutritional requirements of these cultures are different. PMID- 19871640 TI - THE MODIFYING EFFECTS OF CERTAIN SUBSTANCES OF BACTERIAL ORIGIN ON THE COURSE OF INFECTION WITH PNEUMONIA VIRUS OF MICE (PVM). AB - Evidence is presented which indicates that certain polysaccharide preparations derived from various bacterial species, as well as similar materials not of bacterial origin, are capable of lessening the severity of infection with pneumonia virus of mice (PVM) and inhibiting multiplication of the virus in mouse lungs infected with this agent. It seems probable that modification with respect to the virus is mediated by a substance which may be polysaccharide in nature. PMID- 19871641 TI - MULTIPLICATION AND SPREAD OF THE VIRUS OF ST. LOUIS ENCEPHALITIS IN MICE WITH SPECIAL EMPHASIS ON ITS FATE IN THE ALIMENTARY TRACT. AB - 1. Beginning at 24 hours after intravenous injection of about 10 million intracerebral LD(50) of virus there was evidence of simultaneous, progressive multiplication in the brain and intestinal tract. 2. When the virus was introduced directly into the brain or the nasal cavities and mouth, none was found in the intestinal tract until there was general centrifugal spread from the central nervous system during the last stages of the infection at 96 or 120 hours after inoculation when the virus in the entire brain had reached a concentration of about 3 billion LD(50). 3. Centrifugal spread began when the virus in the brain reached a concentration of about 400 million LD(50) and virus appeared in the pharynx, tongue, and adrenals before it was demonstrable in the intestinal tract, blood, or viscera such as the spleen, liver, and kidneys. 4. Despite the high concentrations of virus which developed in the intestinal tract following intravenous inoculation, it was not demonstrable in the stools, differing in this respect from Theiler's virus in mice and poliomyelitis virus in human beings and monkeys. 5. No antiviral agent was found in the stools, but the urine of normal mice having a pH of 5.6, inactivated large amounts of St. Louis encephalitis virus. 6. There was no evidence of multiplication in the nasal mucosa of mice which succumbed with encephalitis following nasal instillation of the virus, the course of events being comparable in this respect to the behavior of the M.V. poliomyelitis virus in rhesus monkeys. 7. At the terminal stage of infection the virus content per milligram of tissue was as great in the leg muscles as in the sciatic nerves. Since this was also true for the urinary bladder, heart, lungs, and tongue among other tissues, and since the amount in the blood was too negligible to account for it, it would appear that the virus either accumulated in these tissues by diffusion from the nerve fibers, along which it was spreading from the central nervous system, or that it multiplied in some constituent other than the nerve fibers. PMID- 19871642 TI - THE RELATION TO THE COURSE OF AVIAN MALARIA OF BIOTIN AND A FAT-SOLUBLE MATERIAL HAVING THE BIOLOGICAL ACTIVITIES OF BIOTIN. AB - Biotin deficiency produced by a synthetic biotin-deficient diet was as effective in decreasing the resistance of chickens to infection with Plasmodium lophurae as biotin deficiency produced by a diet high in egg white. In moderately biotin deficient ducks Plasmodium cathemerium at first multiplied more slowly than in adequately fed controls. The parasitemia in the deficient animals later overtook that in the controls and attained higher peak parasite numbers. The multiplication of P. cathemerium was notably inhibited in ducks inoculated when they were approaching death from biotin deficiency. The total and differential leucocyte count of biotin-deficient chickens did not differ significantly from that of adequately fed controls. During infection of chickens with P. lophurae and ducks with either P. lophurae or P. cathemerium significant changes occur in the concentration in the plasma of free biotin and of a material which on hydrolysis yields a fat-soluble substance (FSF) having the biological activities of biotin but differing chemically from it. In ducks which survived infections with P. cathemerium or P. lophurae the biotin concentration rose very early in the course of the infection, before there was any anemia. It fell slightly, rose to a peak at about the time of the peak parasite number, and then returned to normal. The concentration of bound FSF, which was determined in terms of its biotin activity, increased at first, then decreased, then rose and continued at a high level throughout the period of decline in parasitemia. In most of the animals which died of either infection the free biotin, instead of returning to normal, rose to very high values Just before death, while the bound FSF, instead of remaining at a high value, fell to very low values, reaching zero in several animals. Greater resistance seemed to be associated with a greater excess of bound FSF over free biotin. In animals about to die the free biotin exceeded the bound FSF. The biotin content of the liver of ducks and chickens fed an adequate diet and killed just after having undergone an infection with either P. lophurae or P. cathemerium was much less than that of control uninfected animals. When P. lophurae was cultured in vitro in suspensions of duck erythrocytes a very wide range in biotin concentration in the culture fluid did not affect its rate of multiplication. Plasma protein fractions relatively rich in FSF at a concentration of 0.75 per cent inhibited multiplication, while comparable concentrations of plasma fractions poor in FSF did not. The results obtained fit the assumption that the substance in plasma which yields FSF is directly concerned in resistance to avian malaria. PMID- 19871643 TI - IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : IV. PREPARATION OF BLOOD GROUP A SUBSTANCES FROM HUMAN SOURCES AND A COMPARISON OF THEIR CHEMICAL AND IMMUNOCHEMICAL PROPERTIES WITH THOSE OF THE BLOOD GROUP A SUBSTANCE FROM HOG STOMACH. AB - 1. Blood group substances have been prepared from human saliva, stomach, and amniotic fluid from individuals of blood group A(1) and A(2). Several of the saliva samples were obtained from individuals shown to be heterozygous, A(1)O. 2. The purified blood group A substances from human sources were similar in nitrogen, glucosamine, reducing sugar, and acetyl content. The A(1) and A(2) substances differed in optical rotation. All of the human A samples were levorotatory while those from hog stomach were dextrorotatory. 3. By two immunochemical criteria the various human preparations could be shown to fall into distinct groups, with respect to purity. The best products showed maximal activity and almost all of their glucosamine was specifically precipitable by anti-A. These samples of human A substance were only about one-half as effective in precipitating antibody to hog A substance formed in man as was homologous hog A substance although the same total amount of antibody was precipitable by excess of either antigen. 4. Human blood group A(1) substance was found to be antigenic in individuals of blood groups B and O but was not as good an antigen as hog A substance. PMID- 19871644 TI - FACTORS INVOLVED IN PRODUCTION OF CLOSTRIDIUM WELCHII ALPHA TOXIN. AB - Maximum production of the alpha toxin by Cl. welchii is dependent on the inclusion in the medium of several substances in addition to those required for growth. These factors include: 1. Some substance present in enzymatic digests of certain proteins such as casein and gelatine. 2. Glycerylphosphorylcholine and other substances that are present in extracts of pancreas. 3. The use of starch or dextrin as a carbohydrate source in the absence of other fermentable carbohydrates. The omission of any one of these factors from the medium results in a very low yield of alpha toxin. PMID- 19871645 TI - RELATION OF IRON SALTS TO INHIBITION OF GLYCOLYSIS BY THEILER FA VIRUS OF MOUSE ENCEPHALOMYELITIS. AB - 1. Brain homogenates of mice infected with the Theiler FA strain of mouse encephalomyelitis virus show marked inhibition of glucose phosphorylation. 2. A similar effect can be obtained by incubating normal brain homogenates with small amounts of ferrous sulfate. 3. Partially purified preparations of Theiler FA virus contain iron in amounts corresponding to their inhibitory effect on brain glycolysis. The virus preparations were purified by chemical fractionation and differential centrifugation and were dialyzed against potassium cyanide or pyrophosphate and potassium chloride for several days before they were analyzed for iron content. 4. The inhibitory effect of the virus preparations and of ferrous sulfate has been shown to be dependent on a heat-labile factor present in normal brain ("inactivating factor"). 5. The glycolytic activity of brain homogenates of mice infected with the Theiler FA virus can be restored by addition of a factor prepared from rabbit muscle extract. This "restoring factor" is non-dialyzable and is heat-labile. It has no hexokinase or phosphohexokinase activity. Its restoring activity is destroyed by the "inactivating factor" present in brain. PMID- 19871646 TI - THE MECHANISM OF AERIAL DISINFECTION BY GLYCOLS AND OTHER CHEMICAL AGENTS : I. DEMONSTRATION THAT THE GERMICIDAL ACTION OCCURS THROUGH THE AGENCY OF THE VAPOR PHASE. AB - Theoretical analysis of the mechanism of action of chemical aerial disinfectants reveals that the rapid killing action which is obtained cannot be accounted for by a collision process between germicidal aerosol particles and the air-borne bacteria. However, a mechanism involving condensation of germicide molecules in the vapor state on to the bacteria-containing droplets results in a theoretical velocity of the correct order of magnitude. Experimental tests of this theory show that pure germicide vapors free of aerosol droplets are almost instantly lethal to air-borne bacteria. Conversely, pure germicidal aerosols in the absence of vapor, had no effect on air-borne bacteria within 20 minutes or more. Therefore, it may be concluded on both theoretical and experimental grounds that rapid air sterilization requires the existence of the germicide in the vapor state. PMID- 19871647 TI - THE MECHANISM OF AERIAL DISINFECTION BY GLYCOLS AND OTHER CHEMICAL AGENTS : II. AN ANALYSIS OF THE FACTORS GOVERNING THE EFFICIENCY OF CHEMICAL DISINFECTION OF THE AIR. AB - The effectiveness of any compound as an aerial germicide depends upon the extent of condensation of its vapor on air-suspended bacteria, and on the rate at which the resulting concentration of germicide can produce death of the microorganisms. The properties of any compound conducive to production of the highest rate of kill of air-borne microorganisms by means of the smallest possible concentration of germicide vapor, are as folows: (a) a low vapor pressure, but not lower than 0.001 mm. Hg at 25 degrees C.; (b) high hygroscopicity; (c) toxicity for bacterial metabolism-a high degree of potency is not necessary although the killing action will be more efficient the higher the antibacterial activity of the compound employed. For any compound the killing action is always a direct function of the concentration of its vapor in the air. The maximum amount of a hygroscopic substance which can exist in the vapor state decreases as the relative humidity increases. Hence, at high relative humidities the bactericidal efficiency is lowest. At lower relative humidities the air can contain more vapor, and hence a greater effect is possible. At any relative humidity, the killing action is greater, the more closely the germicide vapor concentration approaches the saturation point. The presence of soluble compounds in droplets containing bacteria promotes more extensive condensation of the germicide than would otherwise occur, and so enhances its effectiveness. In the absence of such soluble substances, low atmospheric humidities may cause complete desiccation of a bacterial particle. Under these conditions its surface may become resistant to the condensation of the vapor, and thus prevent effective germicidal action. The influence of temperature changes on the killing efficiency maybe correctly deduced from a consideration of the effect of a rise in temperature on the vapor pressure of the germicide and on the rate of its bactericidal action in vitro. Equations are presented for estimating quantitatively the magnitude of some of the effects discussed. PMID- 19871648 TI - THE TRANSMISSION OF THE VIRUS OF LYMPHOCYTIC CHORIOMENINGITIS BY TRICHINELLA SPIRALIS. AB - In experiments in which guinea pigs were infected concurrently with the virus of lymphocytic choriomeningitis and the parasitic nematode, Trichinella spiralis, proof was obtained that trichinella larvae, after maturation in the muscles, had acquired the virus and were capable of transmitting it to new susceptible hosts. Transmission resulted both when living larvae were fed to normal guinea pigs and when triturated dead larvae were injected subcutaneously. Control experiments and other tests made plain that transmission of the virus was not due to mere adherence of it to the outer surface of the larvae but that these actually harbored it. The significance of these experiments in relation to natural transmission of the virus of lymphocytic choriomeningitis remains to be determined. PMID- 19871649 TI - CHEMICAL STUDIES ON HOST-VIRUS INTERACTIONS : III. TRYPTOPHANE REQUIREMENTS IN THE STAGES OF VIRUS MULTIPLICATION IN THE ESCHERICHIA COLI-T2 BACTERIOPHAGE SYSTEM. AB - The inhibition of virus multiplication by 5-methyl tryptophane can be specifically reversed by tryptophane. The conditions of reversal indicate that 5MT specifically interferes with tryptophane utilization. The tryptophane requirements of virus multiplication appear to exist throughout the latent period and determine the time of lysis and amount of virus liberated. A latent period may be interrupted for 15 minutes or more and be resumed on addition of tryptophane. Extended inhibition with 5MT results in a somewhat variable "killing" effect, the extent of which determines aspects of the reversal of the inhibition by tryptophane. The implications of these phenomena have been discussed. PMID- 19871650 TI - MORPHOLOGICAL AND OTHER CHARACTERISTICS OF THE AGENT OF FELINE PNEUMONITIS GROWN IN THE ALLANTOIC CAVITY OF THE CHICK EMBRYO. AB - The agent of feline pneumonitis has been grown in the allantoic cavity for 50 serial passages. During this time the amount of agent in allantoic fluid increased about 100-fold. The titer of the agent in the allantoic fluid of the individual embryo reached a peak on the 5th day and then declined. Large inocula were required in order to obtain maximal titers. The toxic factor was present in suspensions of chorioallantoic membranes in allantoic fluid from heavily infected eggs, and could be neutralized by the specific antitoxin produced in rabbits by injection of toxin in yolk sac suspensions. Electron micrographs of the agent of feline pneumonitis grown in the allantoic cavity show that the elementary body is composed of a dense centrally located substance surrounded by a thinner material, part or all of which is the limiting membrane. Separation of these two portions of the body may be due partially or entirely to distortion during drying. The wrinkled surface of the elementary bodies is evidence that such distortion does occur. The average diameter of gold-shadowed bodies is 525 mmicro. PMID- 19871651 TI - STUDIES ON SPREADING FACTORS : II. THE EFFECT OF SERUM UPON HYALURONIDASE SPREADING ACTIVITY. AB - The reaction between normal serum and hyaluronidase has been studied in vitro and under in vivo conditions in skin. Using in vitro conditions of incubation, serum exhibits antihyaluronidase activity as measured by assay of hyaluronidase spreading activity in skin. This confirms the work of others, who have previously described the serum inhibitory factor using other tests of hyaluronidase activity. When, however, hyaluronidase and setum are allowed to incubate in skin under in vivo conditions, no inhibitory influence of serum upon hyaluronidase spreading activity is evident. This latter finding has been taken to indicate that the environmental conditions in skin are unfavorable for the inhibitory reaction of serum upon hyaluronidase. The disparity between the in vivo and in vitro effectiveness of serum, and the significance of the serum factor as a defense mechanism against invasive processes, have been briefly discussed. PMID- 19871652 TI - TOLERANCE TO BACTERIAL PYROGENS : I. FACTORS INFLUENCING ITS DEVELOPMENT. AB - In a study of the febrile responses of rabbits to repeated intravenous injections of pyrogenic substances from Eberthella typhosa, Serratia marcescens, and Pseudomonas aeruginosa, the following observations were made: 1. A characteristic pattern of response to daily injections of the same dose of pyrogenic material was noted. This consisted of a progressive diminution in febrile response during the 1st week or 10 days, after which an animal responded to each injection with approximately the same degree of fever, even when the injections were continued for several weeks. 2. Animals given injections of the same amount of pyrogenic material at semiweekly or weekly intervals showed some diminution in febrile reaction but the alteration was less pronounced than that in animals injected every day. 3. Pyrogen tolerance appeared to be lost quickly. Animals allowed to rest for approximately 3 weeks reacted to readministration of pyrogen with fever comparable with that which occurred after the first injection. 4. By gradually increasing the size of the daily dose of pyrogen a tolerance could be established such that a reduced, but still considerable, amount of pyrogen caused no fever whatever. 5. Rabbits that had been injected with S. marcescens or Ps. aeruginosa pyrogens showed a diminished febrile response to E. typhosa vaccine. 6. Passive transfer of the unresponsiveness to pyrogens could not be demonstrated. 7. Prevention of temperature elevations during the course of immunization by use of an antipyretic drug did not interfere with the development of tolerance to pyrogens. 8. A series of mechanically induced bouts of fever did not reduce the responsiveness to bacterial pyrogens. PMID- 19871653 TI - TOLERANCE TO BACTERIAL PYROGENS : II. ROLE OF THE RETICULO-ENDOTHELIAL SYSTEM. AB - IN EXPERIMENTS DESIGNED TO ELUCIDATE THE MECHANISM BY WHICH TOLERANCE TO BACTERIAL PYROGENS IS DEVELOPED, THE FOLLOWING OBSERVATIONS WERE MADE: 1. Animals whose febrile reactions to bacterial pyrogens were markedly diminished, as a result of repeated injections, showed increases in response following R-E blockade. 2. Pyrogenic substances disappeared from the circulating blood more rapidly in rabbits rendered pyrogen-tolerant than in normal animals. Lack of specificity was shown by the fact that rabbits previously injected with Eberthella typhosa bacterial vaccine were able to remove the pyrogens of Serratia marcescens and Pseudomonas aeruginosa from their blood more rapidly than normal animals. 3. R-E blockade-retarded the speed of disappearance of pyrogens from the circulating blood of animals which had been rendered relatively tolerant by previous injections of these substances. A possible mechanism for the development of unresponsiveness to bacterial pyrogens is suggested. PMID- 19871654 TI - CYTOCHONDRIA OF NORMAL CELLS, OF TUMOR CELLS, AND OF CELLS WITH VARIOUS INJURIES. AB - Bodies that may be designated cytochondria occupy the greater part of the cytoplasm of the normal and tumor cells that have been studied. They are characterized (a) by their behavior as discrete particles with surface properties that cause osmotic changes in the presence of water; (b) by reactions to stains which show that they have a rim surrounding a clearer (lipoid) center; (c) by their varying, relation to the basophile substance (ribonucleic acid) of the cytoplasm. Mitochondria which have characteristic reactions to stains promptly lose their distinctive reactions in the presence of solvents or as the result of pathological changes, becoming apparently indistinguishable from other cytochondria. Changes that occur in cytochondria give insight into the pathogenesis of a variety of pathological lesions. Hydropic swelling of cytochondria caused by chloroform, butter yellow, and other agents, representing one variety of parenchymatous degeneration or cloudy swelling, results in changes similar to those following the immersion of fresh tissues in water. When parenchymatous cells undergo fatty degeneration as the result of injury fat accumulates within cytochondria. PMID- 19871655 TI - INHIBITION BY CERTAIN POLYSACCHARIDES OF HEMAGGLUTINATION AND OF MULTIPLICATION OF INFLUENZA VIRUS. AB - The complex carbohydrates apple pectin, citrus pectin, flaxseed mucilage, blood group A substance, gum acacia, and gum myrrh as well as an extract of RBC, when examined in a pattern test, were shown to inhibit the agglutination of chicken RBC by influenza A virus. A number of other simple and complex carbohydrates showed no inhibitory effect. The hemagglutination-inhibiting action of apple pectin was examined in some detail and evidence was adduced to show that it affected both virus and red cell. Apple pectin was also found to inhibit the multiplication of influenza A virus in embryonated eggs. PMID- 19871656 TI - THE NATURE OF NON-SPECIFIC INHIBITION OF VIRUS HEMAGGLUTINATION. AB - A study of the component in serum and tissue extracts responsible for non specific inhibition of hemagglutination with mumps virus and the PR8 and Lee strains of influenza virus has yielded the following results: 1. The inhibitory factor was found in high titer in human serum and in saline extracts of various organs procured at autopsy (lung, liver,kidney, spleen). The inhibition titers of extracts of these organs were usually higher than the serum titers, whereas the titers of muscle extracts were invariably lower. 2. Similar results were obtained with serum and tissue extracts from normal rabbits and guinea pigs. 3. The serum inhibition titers were not affected by heating to 75 degrees C. for 30 minutes, whereas the titers of the tissue extracts were usually reduced by heating at 65 degrees C. or 75 degrees C. for 30 minutes. 4. Saline extracts of human and chicken red blood cells also contained an inhibitory substance in high titer, and these cells showed marked agglutination with influenza and mumps viruses. Rabbit red cells, on the other band, underwent little or no agglutination with these viruses and extracts of these cells failed to cause inhibition. Sheep red cells varied in their capacity to agglutinate and also in their yield of the inhibitory substance. 5. When the virus receptor substance was removed from chicken red cells by adsorption and elution with influenza virus, extracts of the cells no longer yielded the inhibitory factor. 6. The inhibitory substance did not neutralize influenza virus in mice and it failed to fix complement when mixed with influenza or mumps viruses. 7. Evidence was obtained that some virus was released from the inhibitory substance after incubation for 6 hours at 22 degrees C. or 37 degrees C. The implications of these findings are discussed. PMID- 19871657 TI - ABSORPTION FROM THE PULMONARY ALVEOLI. AB - Experiments upon dogs anesthetized with nembutal and lasting 4 hours, in which the right lymphatic duct and thoracic duct have been cannulated and collection of lung lymph and blood specimens was accomplished after intratracheal instillation of dog plasma, purified bovine serum albumin, crystallized egg albumin, and hemoglobin, have shown that the absorption of such molecules is slight. Experiments in which pyrex glass spheres averaging 4 micra in diameter were instilled failed to disclose entrance of these distinctive foreign particles into the lymph stream, though the fact that lung phagocytes were often found containing the particles or covered with them, indicated that eventually these particles would be found in lung lymphatics and in lymph nodes. The protection against absorption from the lung alveoli is in the main due to intact alveolar epithelium through which molecules of the dimensions of the proteins. commonly entering the alveoli, as a result of trauma or disease, pass very slowly and are found in small traces in lung lymph and even to a less degree in blood. PMID- 19871658 TI - ON THE ORIGIN OF HEPARIN : AN EXAMINATION OF THE HEPARIN CONTENT AND THE SPECIFIC CYTOPLASMIC PARTICLES OF NEOPLASTIC MAST CELLS. AB - 1. The spontaneous mast cell tumor of the dog contains heparin. 2. The cytoplasmic particulate content of the tumor mast cells varies with their anaplasia. This conclusion is based on the following findings: (a) in the immature cell of the more malignant tumor the particulate matter appeared in the living cells by phase microscopy to be composed of greyish illdefined particles or as a fine, weakly metachromatic granulation in the fixed and stained preparation; (b) in the mature cells of a relatively benign mast cell tumor, both in the living cell and in stained preparations, the particulate matter occurred in the form of discrete, dense, and strongly metachromatic granules, resembling those of the normal mast cell. 3. The heparin content was large (fifty times that of dog liver) in the growth with mature cells and only moderate (1.7 times) in that with immature cells. 4. Since there may be a great amount of greyish particulate matter (or fine stained granules) in a tumor of relatively low heparin content, it is suggested that this material represents an early or precursor phase in the development of heparin. 5. This possibility and the fact that the blood stream may be invaded by mature tumor mast cells of large heparin content without evident disturbance in the coagulability of the blood suggest the value of a comprehensive biochemical study of the heparin of mast cell tumors. PMID- 19871659 TI - THE MORPHOLOGY AND BEHAVIOR OF NEOPLASTIC MAST CELLS CULTIVATED IN VITRO. AB - Fragments from two mast cell tumors of the dog have been cultured in vitro. Studies on the living and on fixed and stained preparations revealed the following: Only mast cells grew out from the original tumor fragments though these contained other types of cells. They grew in some of the roller tube cultures in a sheet resembling an epithelium but in hanging drop cultures they lay separate and were irregularly spindle or star-shaped with long protoplasmic processes. The cytoplasmic granules of the proliferating mast cells varied in size, number, and tinctorial properties. In most of the cells they stained metachromatically, in occasional cells some of the granules only could be stained, and in a few none could be stained. PMID- 19871660 TI - AMINO ACID COMPOSITION OF HIGHLY PURIFIED VIRAL PARTICLES OF INFLUENZA A AND B. AB - Microbiological assays for amino acids were made on hydrolysates of four to five highly purified preparations each of influenza A virus (PR8 strain) and influenza B virus (Lee strain). The results of the assays indicated that these strains of influenza virus contain approximately the same amounts of alanine, aspartic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, and valine. However, significant differences were found in the values for arginine, glutamic acid, lysine, tryptophane, and tyrosine. It is believed that these differences may provide, at least in part, a chemical explanation for some of the differing properties of the PR8 and Lee strains of influenza viruses. PMID- 19871661 TI - THE SUPERINFECTION OF THE RABBIT PAPILLOMA (SHOPE) BY EXTRANEOUS VIRUSES. AB - 1. The potentialities that viruses have for the superinfection of virus tumors have not been recognized nor has the fact that a single cell can harbor more than one virus. 2. Rabbit papillomas, induced by the papilloma virus (Shope), were superinfected by B virus, myxoma virus, vaccinia virus, and probably, virus III. Similar attempts at superinfection by herpes virus were without success. The criteria for parasitization included the histopathological finding of specific inclusion bodies, the recovery of each virus by suitable animal passage, and the immunological identification of each virus. 3. Papillomas and probably the individual cells thereof were readily infected simultaneously by two viruses when the combination of B virus and myxoma virus was used. 4. Cells of the Shope papilloma have a selective affinity for certain extraneous viruses introduced at a site distant from the tumor growths. It was found that exceptionally few cells in the basal layers of the epidermis escaped when myxoma virus was used as the superinfecting agent. 5. The cells of an epidermoid carcinoma which terminated the rabbit papilloma-to-carcinoma sequence were readily infected by B virus with resultant multiple intranuclear inclusion bodies in single cells. 6. Attempts to establish a prolonged superinfection of cells of the Shope papilloma by virus III were unsuccessful. This rabbit tumor differs therein from the Brown-Pearce tumor, an epithelioma of rabbits, in its susceptibility to infection with virus III. PMID- 19871662 TI - MULTIPLE VIRUS INFECTION OF SINGLE HOST CELLS. AB - Evidence is presented to show that two or more viruses can simultaneously manifest their characteristic activities within individual epithelial cells of the normal rabbit's cornea. This evidence, together with that previously presented (1, 5, 6), makes plain that multiple virus infection of a single host cell can take place in corneal cells, in the cells of chick embryos, and in those of rabbit tumors, both benign (Shope's papilloma) and malignant. Certain implications of the findings are discussed. PMID- 19871663 TI - THE INFLUENCE OF INJECTIONS OF HOMOLOGOUS HEMOGLOBIN ON THE KIDNEYS OF NORMAL AND DEHYDRATED ANIMALS. AB - 1. Dehydration, if sufficiently prolonged, favors the accumulation of hemoglobin or its derivatives in the kidneys of rabbits, principally casts formed in the distal convoluted tubules. 2. Once pigment casts have been produced in the distal convoluted tubules, there is obstruction, with atrophy and dilatation of the tubules proximal to the obstruction. 3. When the involvement is sufficiently extensive, there is elevation of the non-protein nitrogen and some animals die because of renal failure. PMID- 19871664 TI - INFECTION OF MICE WITH MAMMALIAN TUBERCLE BACILLI GROWN IN TWEEN-ALBUMIN LIQUID MEDIUM. AB - Introduction of the bacilli by the mtravenous route or by feeding gives rise to a disease predominantly localized in the lungs. Following intracerebral infection, the bacilli first multiply rapidly in the brain tissue, and then invade other organs, producing lesions especially in the lungs. Injection of the bacilli by the intraperitoneal route is less effective than by either the intravenous or intracerebral routes; however, admixture of the bacilli with some of the components of egg yolk increases both the infectivity and the pulmonary localization. Different strains of mice differ markedly in their susceptibility to experimental tuberculous infection; the highest susceptibility was observed among the pigmented strains (line 1 dba and C57 black). Greater resistance does not appear to depend on the ability to prevent the establishment of infection, but rather corresponds to a slower rate of progression of the infectious process. It is possible to produce in mice tuberculosis presenting any desired degree of acuteness or chronicity by controlling certain factors which condition the initiation and the progression of the infection. PMID- 19871665 TI - VIRULENCE AND MORPHOLOGICAL CHARACTERISTICS OF MAMMALIAN TUBERCLE BACILLI. AB - Experimental infection of the mouse can be used for the determination of virulence of cultures of mammalian tubercle bacilli. The relative virulence of such cultures for the mouse is approximately the same as for the guinea pig. Cultures of virulent and avirulent variants of mammalian tubercle bacilli grown in the depth of Tween 80-albumin liquid medium, on the surface of solid agar modifications of this medium, and on the surface of a liquid modification of this medium exhibit consistent morphological differences. All virulent cultures tend to form microscopically demonstrable serpentine cords of varying thickness and length consisting of highly acid-fast bacilli oriented in parallel along the long axis of the cord. The formation of cords appears to be an important factor in conditioning the ability of cultures to spread on the surface of liquid and solid media. It can be inhibited by the addition to the medium of the surface-active water-dispersible oleic acid ester, Tween 80. Avirulent variant bacilli grow in a more or less non-oriented fashion. They have never been observed to form cords under any condition of growth and are much less acid-fast than the virulent cultures when grown in Tween-albumin medium. Two strains of mammalian tubercle bacilli which are intermediate in degree of virulence between the fully virulent and the avirulent variants also exhibit intermediate morphological characteristics. PMID- 19871666 TI - CHANGES IN THE PLASMA PROTEIN PATTERN (TISELIUS ELECTROPHORETIC TECHNIC) OF PATIENTS WITH HYPERTENSION AND DOGS WITH EXPERIMENTAL RENAL HYPERTENSION. AB - The plasma protein pattern of patients with uncomplicated essential hypertension showed only slight variations from the normal while that of patients with severely malignant hypertension showed marked shifts. The fibrinogen and beta globulins were usually elevated beyond the normal range and the albumin decreased. In less severely malignant hypertension, the changes were less marked. In dogs with experimental renal hypertension, the gamma-globulin level was greatly elevated, and in one animal exhibiting the malignant syndrome beta globulin and fibrinogen were also increased. Elevation of beta-globulin seems in some manner associated with the occurrence of severe vascular disease. PMID- 19871667 TI - ANTIPROTEINS IN HORSE SERA : II. ANTIBODIES TO PNEUMOCOCCUS NUCLEOPROTEIN AND THEIR REACTION WITH ANTIGEN. AB - The antiprotein in an antipneumococcus horse serum resulting from intravenous injections of infected pleural exudate showed a precipitin type of reaction with pneumococcus nucleoprotein rather than the antitoxin type of response. PMID- 19871668 TI - ANTIPROTEINS IN HORSE SERA : III. ANTIBODIES TO RABBIT SERUM ALBUMIN AND THEIR REACTION WITH ANTIGEN. AB - 1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin. 2. The resulting antibody resembled diphtheria antitoxin and anti-egg albumin in the horse in giving a sharp zone of flocculation with antigen, in being water-soluble, in reactivity toward an anti-antibody rabbit serum, and in its electrophoretic properties. 3. The effect of continued immunization, and of variation in volume and temperature on the reactivity of the antibody are discussed. 4. Intravenous injection of the same antigen into horses did not give rise to detectable amounts of antibody of the same type. PMID- 19871669 TI - ANTIPROTEINS IN HORSE SERA : IV. ANTIBODIES TO RABBIT SERUM GLOBULIN AND THEIR INTERACTION WITH ANTIGEN. AB - 1. The intravenous injection of two horses with alum-precipitated rabbit serum globulin resulted in the production of antibody which gave a typical precipitin reaction without a prezone in the region of antibody excess. 2. The chemical, physical, and serological properties of this antibody are comparable to those of the more familiar anticarbohydrate antibodies. 3. The subcutaneous injection of horses with the globulin antigen gave rise to low grade "univalent" antibody which did not precipitate with soluble antigen. 4. The low grade antibody could be removed from solution by attachment to preformed specific precipitates, or by coprecipitation in the presence of "multivalent" precipitating antibody. 5. It is concluded that the familiar antitoxin type of antibody is not the only form of antiprotein response in horses but that precipitating and low grade non precipitating antibodies may also be formed. 6. The nature of the antigen and the route of injection are demonstrated to be important factors in determining the characteristics of the antibody formed. PMID- 19871670 TI - THE TOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : III. INDUCTION IN MICE OF TEMPORARY RESISTANCE TO THE LETHAL EFFECT OF THE TOXIN. AB - 1. The susceptibility of mice to the lethal effect of preparations containing the oxygen-labile hemolysin (streptolysin O) of group A hemolytic streptococci has been studied. Injection of a single sublethal dose of the streptococcal preparation causes the development of resistance to the effect of a lethal dose injected subsequently. 2. Resistance is demonstrable 3 to 6 hours after the injection of the streptococcal preparation, persists for approximately 30 hours, and then disappears. 3. Resistance induced by the streptococcal preparation, although relatively specific, is directed not only against the streptococcal preparation but also against saponin. Mice made refractory to the streptococcal preparation and to saponin exhibit normal susceptibility to a number of other toxic agents, with the possible exception of the alpha toxin of Cl. welchii. 4. Mice injected with a sublethal dose of saponin develop resistance to the effect of a lethal dose of either saponin or the streptococcal preparation. 5. Resistance depends upon processes distinct from those underlying classical antitoxic immunity. PMID- 19871671 TI - THE ENHANCING EFFECT OF CONCURRENT INFECTION WITH PNEUMOTROPIC VIRUSES ON PULMONARY TUBERCULOSIS IN MICE. AB - The course of pulmonary tuberculosis in the mouse appears to be accelerated as a result of concurrent infection of the lung with either of two pneumotropic viruses. This effect is obtained with virus inocula sufficiently small as to induce little or no definite viral pneumonia. PMID- 19871672 TI - THE BINDING OF FATTY ACIDS BY SERUM ALBUMIN, A PROTECTIVE GROWTH FACTOR IN BACTERIOLOGICAL MEDIA. AB - Serum albumin is a protective bacterial growth factor; by binding traces of fatty acid in the media it permits initiation of growth by the smallest possible inocula of tubercle bacilli. Each molecule of albumin binds 3 to 6 molecules of oleic acid (1 to 2 per cent of the weight of the albumin) tightly enough to prevent bacteriostasis, and 9 molecules of oleic acid in equilibrium with a saturated neutral solution. The property requires undenatured albumin. Crystalline beta-lactoglobulin has a smaller capacity, and a number of other proteins no perceptible capacity to bind oleic acid. The inhibitory effect of the commercial product Tween 80 (polyoxyethylene sorbitan monooleate) on the growth of small inocula of tubercle bacilli in liquid media is caused by its content of unesterified oleic acid (0.6 per cent by weight). Purified Tween 80, freed of this contaminating fatty acid, not only permits growth of small inocula, but protects against small amounts of added oleic acid. The implications of the binding capacity of albumin for its possible physiological significance in the animal body (transport; protection against cytotoxins), and for the structure of the protein, are briefly discussed. PMID- 19871673 TI - ST. LOUIS ENCEPHALITIS : TRANSMISSION OF VIRUS TO CHICKENS BY INFECTED MITES DERMANYSSUS GALLINAE AND RESULTING VIREMIA AS SOURCE OF VIRUS FOR INFECTION OF MITES. AB - Transmission of the virus of St. Louis encephalitis to normal chickens by the bite of infected mites (Dermanyssus gallinae) has been demonstrated. Both experimentally infected and naturally infected mites were shown to be capable of transferring the virus of St. Louis encephalitis to chickens by bite. Virus is present in the blood of such chickens in small amounts, so that demonstration of viremia was possible only by utilizing chorioallantoic passage in hens' eggs. However, there is sufficient virus present in the blood for uninfected chicken mites to acquire the virus by feeding on chickens in which viremia has resulted from previous bite of infected mites. Thus it has been shown that the arachnid vector Dermanyssus gallinae is capable of transmitting the virus of St. Louis encephalitis to normal chickens by bite and that such chickens can serve as a source of virus for uninfected mites. PMID- 19871674 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMONIA DUE TO FRIEDLANDER'S BACILLUS : I. THE PATHOGENESIS OF EXPERIMENTAL FRIEDLANDER'S BACILLUS PNEUMONIA. AB - Experimental pneumonia due to Friedlander's bacillus was produced in white rats by the intrabronchial inoculation of the bacilli suspended in mucin. The pneumonia was lobar in type, was almost uniformly fatal, and simulated the acute form of the natural disease in human beings. The pathogenesis of the pneumonic lesion was studied by examination of microscopic sections of the lungs of animals killed at frequent intervals during the course of the infection. The histologic characteristics of the various stages of the pneumonia were essentially the same as those previously described in experimental pneumococcal (Type I) pneumonia except for the following differences: (1) In isolated areas of the lung in Friedlander's pneumonia many more bacteria were encountered in the alveoli than were ever noted in experimental pneumococcal pneumonia. (2) Abscess formation was common in the late stages of Friedlander's infection, whereas it was not noted in the pneumococcal lesion. (3) Organization of the alveolar exudate, rarely observed in experimental pneumococcal pneumonia, was a prominent feature of the pneumonia due to Friedlander's bacillus. The mechanism of spread of Friedlander's lesion appeared to be the same as that of pneumococcal pneumonia. Likewise there was noted the same phagocytosis of organisms in the lungs of even bacteremic animals dying of the infection. PMID- 19871675 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMONIA DUE TO FRIEDLANDER'S BACILLUS : II. THE EFFECT OF SULFONAMIDE CHEMOTHERAPY UPON THE PULMONARY LESION OF EXPERIMENTAL FRIEDLANDER'S BACILLUS PNEUMONIA. AB - Sulfonamide chemotherapy was found to cure rats of an otherwise fatal form of experimental Friedlander's bacillus pneumonia when treatment was begun 6 hours after inoculation. Most of the pneumonic lesions cleared completely, but an occasional animal exhibited small residual abscesses in the previously consolidated lung. The recovery process taking place in the lungs was studied histologically at various intervals during therapy. As in the case of pneumococcal pneumonia, the principal action of the sulfonamide was upon the bacteria in the advancing edema zone at the periphery of the pneumonic lesion. The bacteriostatic action of the drug appeared to stop the spread of the pneumonia, and the Friedlander bacilli were ultimately ingested and destroyed by the phagocytic cells in the alveolar exudate. The phagocytosis of bacteria in the lung was shown to be unrelated to the presence of antibody in the blood. PMID- 19871676 TI - STUDIES ON THE MECHANISM OF RECOVERY IN PNEUMONIA DUE TO FRIEDLADER'S BACILLUS : III. THE ROLE OF "SURFACE PHAGOCYTOSIS" IN THE DESTRUCTION OF THE MICROORGANISMS IN THE LUNG. AB - Phagocytosis of encapsulated Friedlander's bacilli has been demonstrated in the lungs of rats in the absence of both circulating and local antibody. The mechanism of phagocytosis independent of antibody has been shown to be due to the same surface factors that operate in the phagocytosis of Type I pneumococcus under similar conditions. Direct observation of the phagocytic process reveals that leucocytes in the lung can phagocyte unopsonized Friedlander's bacilli only by trapping them against the surfaces of alveolar walls or bronchi, or by pinning them against the surfaces of adjacent leucocytes. Evidence is presented that Friedlander's bacilli thus phagocyted are rapidly killed in the cytoplasm of the phagocytic cells. Reasons are discussed for the failure of prolonged chemotherapy to cure lung abscesses that not infrequently complicate the pneumonia due to Friedlander's bacillus. PMID- 19871677 TI - STUDIES ON THE CONGLUTINATION REACTION, WITH SPECIAL REFERENCE TO THE NATURE OF CONGLUTININ. AB - 1. Dilution of pooled plasma with more than an equal volume of saline solution destroys its ability to produce conglutination of red cells sensitized by univalent antibody. This can be correlated with Pedersen's work showing that X protein is readily dissociated by dilution. The observation explains the discrepancy between the reports of British and American workers regarding the incidence of Rh "agglutinins" in the serum of Rh-negative mothers of erythroblastotic babies. 2. Plasma has a higher conglutinating activity than serum as shown by the finding that plasma gives titers on the average more than twice as high as those obtained with serum. The greater activity of plasma would seem due to the presence of fibrinogen which is apparently an important component of the colloidal complex of plasma proteins making up conglutinin. 3. Aside from its action in precipitating fibrinogen, heating at 56 degrees C. for onehalf hour has no harmful effect on conglutinin. 4. Fetal plasma and serum yield much lower conglutination titers than adult plasma and serum, indicating that fetal blood is deficient in conglutinin. After birth, there is generally a marked increase in the conglutinin content of the blood. There is little or no variation in the conglutinin activity of sera from different normal adult individuals. 5. The use of whole citrated blood in exchange transfusion to an erythroblastotic baby caused an appreciable rise in the total plasma proteins after the transfusion and a corresponding increase in the conglutinating activity. When however, in another instance, two-fifths of the plasma was removed from the donor's blood and replaced with saline, there was no appreciable change in the protein concentration or conglutinin activity of the infant's plasma after the transfusion. 6. The fortification of pooled plasma by mixing 4 parts of it with 1 part of 25 per cent human albumin solution markedly increased its conglutinin content as shown by a fourfold increase in the conglutination titers obtained. Addition of less or more than this optimal amount of albumin resulted in lower titers. The 25 per cent human albumin solution itself yielded titers only half as high as did unmodified pooled plasma and was difficult to work with because of its high viscosity. Similar results were obtained in experiments with immune globulin solutions and pooled plasma. 7. Albumin solutions of less than 12.5 per cent concentration had little or no conglutinin activity; similarly, immune globulin solutions of less than 4.6 per cent concentration gave only relatively low titers when used as conglutinin. Yet, mixtures of these dilute solutions in certain optimal proportions yielded solutions with conglutinin activities considerably higher than that of pooled plasma. The albumin-globulin ratio in the mixtures giving the best results proved to be approximately the same as the albumin-globulin ratio of normal human serum or plasma. 8. Suitable mixtures of albumin and globulin solutions with a total protein concentration equal to that of normal plasma gave conglutination titers about four times as high as those obtained with unmodified pooled plasma. This suggests that there may be substances in normal plasma which tend to maintain the albumin and globulin in molecular dispersion. Another possibility is that in the fractionation process the albumin and globulin are rendered less hydrophilic, thus increasing their tendency to form colloidal aggregates. 9. The experiments described support the theory that clumping of cells by univalent antibodies in plasma media occurs in two stages, namely, (1) specific adsorption of univalent antibodies, and (2) non specific adsorption of conglutinin by the sensitized cells causing them to stick together. The experiments further support the concept of conglutinin or X-protein as a colloidal aggregate of plasma proteins. Finally, they demonstrate that the intensity of the clumping (conglutination-not agglutination) depends on the quantity and quality of conglutinin and not merely on the total protein content of the medium of suspension. PMID- 19871678 TI - THE FINE STRUCTURE OF CLOTS FORMED FROM PURIFIED BOVINE FIBRINOGEN AND THROMBIN: A STUDY WITH THE ELECTRON MICROSCOPE. AB - 1. A technique has been described for the preparation of clots from purified fibrinogen and thrombin of bovine origin which are suitable for study with the electron microscope. Experiments have been carried out to compare the fine structure of clots prepared at various values of pH. 2. The clots are composed of meshworks of single and compound fibers. At pH 8.5 the unit fibers have a smaller average diameter than those formed at pH 7.6 or pH 6.3. The tendency for the lateral association of unit fibers into compound fibers is markedly increased as the pH is decreased. 3. A striking feature of all the clots studied is cross striation of the unit fibers. The periodicity of these striae is quite constant throughout (approximately 250 A). There is a precise coincidence of the striations of the individual unit fibers where these are associated side by side to form compound fibers. PMID- 19871679 TI - THE RELATIVE PRESSURES WITHIN CUTANEOUS LYMPHATIC CAPILLARIES AND THE TISSUES. AB - The pressure in the cutaneous lymphatic capillaries of normal mice anesthetized with nembutal ranged between 0.0 and 2.7 cm. of water. Measurements of the interstitial pressure in the tissue immediately next the lymphatics showed that, in more than half the instances studied, there was a slight gradient of pressure from the tissues to the lymph. In nearly all the other instances the pressures inside and outside the lymphatic capillaries were approximately equal. In two cases in which lymph flow in the capillaries was rapid, the lymph pressure may have been negative. Under these circumstances there must have been a considerable gradient of pressure from the tissues to the lymph. In skin which was rapidly becoming, or had recently become, edematous as result of the application of xylol or of heat, the intralymphatic capillary pressure generally was increased, yet when compared with the pressure prevailing in the edema fluid outside of the capillaries it was usually found to be relatively much lower, at times by as much as 5.9 cm. of water. The findings indicate that a pressure gradient is an important factor in lymph formation under normal and pathological circumstances. PMID- 19871680 TI - THE SUSCEPTIBILITY OF INFANT RHESUS MONKEYS TO POLIOMYELITIS VIRUS ADMINISTERED BY MOUTH : A STUDY OF THE DISTRIBUTION OF VIRUS IN THE TISSUES OF ORALLY INFECTED ANIMALS. AB - Although rhesus monkeys have been generally regarded as refractory to infection with poliomyelitis virus administered by the oral route, two of seven infant rhesus developed paralytic poliomyelitis when fed murine-adapted strains of virus. Preliminary intranasal treatment with zinc sulfate and negative serial sections of the olfactory bulbs of the positive animals ruled out the possibility that infection occurred by way of the olfactory pathway. Studies on the distribution of virus in the tissues of the infected animals yielded positive results in one animal only. In this instance, virus was widely distributed throughout the body being isolated from spinal cord, buccal mucosa, duodenal wall, colon contents, superficial lymph nodes, spleen, heart, and adrenals. PMID- 19871681 TI - PLASMA ESTERASE ACTIVITY IN PATIENTS WITH LIVER DISEASE AND THE NEPHROTIC SYNDROME. AB - By a study of plasma esterase in various hypoproteinemic states information was gained concerning the synthesis of a protein by the liver, which may be applicable to the problem of albumin synthesis. Patients with infectious hepatitis and cirrhosis showed defective formation of plasma esterase that paralleled the defect in albumin formation. The defect could only be altered in patients with cirrhosis by very prolonged therapy indicating that liver function itself had to improve before the proteins could be formed in a normal manner. Patients with the nephrotic syndrome showed a normal or hypernormal formation of plasma esterase. Following spontaneous remissions or the administration of albumin the esterase level showed a marked rise which was in direct contrast to the difficult alterability of the enzyme level in patients with severe liver involvement. It is suggested that the defect in protein synthesis by patients with the nephrotic syndrome may be due to the lack of certain essential materials, one of which may be albumin itself, rather than to any abnormality in the liver. PMID- 19871682 TI - THE PATHOGENESIS OF THE RENAL INJURY PRODUCED IN THE DOG BY HEMOGLOBIN OR METHEMOGLOBIN. AB - Severe and persistent impairment of kidney function has been produced in dogs by intravascular hemolysis due to arsine, or by the intravenous injection of solutions of dog hemoglobin and methemoglobin. The kidneys of these animals have been examined by the usual histological methods and also by means of the ferrocyanide histochemical method to determine the pathogenesis of the renal injury. These observations indicate that obstruction to flow of urine through the renal tubules is an important factor in the early reduction of kidney function. The material filling the lumina of the renal tubules was found to be chiefly methemoglobin in concentrated solution of gel-like consistency. No evidence of formation of a pigment insoluble at the pH of the urine such as hemochromogen or hematin was found. The cessation of urine flow is most readily explained by the increased viscosity of the tubule contents. The intravenous administration of methemoglobin was found to produce more severe renal injury than the injection of equal amounts of oxyhemoglobin. Necrosis of the proximal convoluted tubule cells was present as a late lesion in animals injected with methemoglobin, large amounts of hemoglobin, or following extensive intravascular hemolysis. Such injury is probably a contributing factor in the persistent severe depression of renal function seen in these animals. Following disappearance of most of the intratubular pigment, a large number of collapsed tubules lined by hemosiderin filled cells were found. The ferrocyanide histochemical studies indicated that these represented non-functioning nephrons although no obstructing intratubular material was present. Direct measurements in two animals failed to reveal any reduction of renal blood flow following the injection of methemoglobin in amounts sufficient to produce renal injury. PMID- 19871683 TI - STUDIES ON THE MECHANISM OF ADAPTATION OF INFLUENZA VIRUS TO MICE. AB - 1. When strains of influenza A virus which have been isolated in chick embryos are introduced into the mouse lung, the virus multiplies readily and achieves initially a titer which is as high as is even obtained, even after repeated passage. The high initial titer of virus may be unaccompanied by any lethal or visible pathogenic effects; but with four or five mouse passages the agent becomes lethal in high titer and causes extensive pulmonary consolidation, though its capacity to multiply in the lung has not increased. In one example the adaptation to mouse lung was accompanied by increasing capacity to agglutinate guinea pig red cells without a corresponding increase in agglutinating power for chicken cells. Influenza B virus, in preliminary tests, did not behave in a similar fashion. 2. The adaptation of influenza A virus to mice is accompanied by changes in antigenic pattern, as detected by cross-tests with the agglutination inhibition method. Two strains, initially similar, with passage, changed in pattern along divergent paths so that they became not only unlike the parent strains but unlike each other. This finding has important implications for the interpretation of the strain difference problem in human influenza. PMID- 19871684 TI - COMPARISONS OF INFLUENZA VIRUS STRAINS FROM THREE EPIDEMICS. AB - Some of the peculiarities of strains of influenza A and B virus from two epidemics have been described. The influenza B virus of 1945-46, when compared with influenza A virus, proved to be much more difficult to isolate from human sources by any known means. Its adaptation to the chick embryo (by any route) or to mice was much slower than that of A virus. It did not keep nearly as well on storage at -72 degrees C. either in throat garglings or as passage material. Its adaptation to amniotic growth was usually much better than to allantoic growth even after repeated allantoic passages. It failed to show primary evidence of occurring in the O form, although many of the secondary O characteristics were present and persisted. Its titer in throat washings was not demonstrably high as compared with certain strains of A virus, which were demonstrated in garglings at dilutions of 10(-5) and 10(-6). The antigenic patterns of influenza A strains from two epidemics were compared. No antigenic differences of significant degree were found among the strains of either epidemic and the difference between the strains of the two epidemics was very slight. A similar study was made of the influenza B strains of the epidemic of 1945-46. This also showed complete lack of significant strain differences. The implications of these findings for influenza prophylaxis are discussed. PMID- 19871685 TI - THE EFFECT OF SULFHYDRYL GROUPS ON PNEUMONIA VIRUS OF MICE (PVM). AB - Evidence is presented which indicates that PVM is affected adversely in concentrated lung tissue suspensions or in the presence of glutathione. Because iodoacetamide inhibits or eliminates these effects in a similar manner, it is concluded that sulfhydryl groups are essential to their development. PMID- 19871686 TI - STUDIES ON A LUNG TISSUE COMPONENT WHICH COMBINES WITH PNEUMONIA VIRUS OF MICE (PVM). AB - Evidence has been obtained which indicates that the lung tissues of mammalian species susceptible to infection with PVM contain a specific component which combines with the virus. The concentration of this tissue component appears to be directly proportional to the suceptibility of the species; in its absence infection with PVM cannot be established. The available evidence suggests that the presence of the virus-combining component in lung tissue may play a decisive ro1e in the initiation of infection with this pneumotropic virus. PMID- 19871687 TI - TRANSMISSION OF EPIDEMIC GASTROENTERITIS TO HUMAN VOLUNTEERS BY ORAL ADMINISTRATION OF FECAL FILTRATES. AB - Epidemic gastroenteritis was transmitted to human volunteers by the oral administration of fecal filtrates. The original inocula were obtained from patients in a natural outbreak which occurred at Marcy State Hospital in the winter of 1946-47. The experimental disease closely resembled that of the donors. The incubation period ranged from I to 5 days, with a mean of 3 days. The disease was carried through three generations, in the last two by means of fecal filtrates. Oral administration of unfiltered throat washings from experimental cases of the disease likewise induced gastroenteritis but subjects who inhaled a portion of the same throat washings remained asymptomatic. Volunteers who inhaled throat washings taken from patients in the epidemic at Marcy State Hospital also failed to develop the disease. Five volunteers who had previously been inoculated with fecal filtrates were reinoculated with the same material. Gastroenteritis followed in one of the two subjects who had failed to contract the disease the first time. The others remained well. Embryonated hens' eggs were inoculated with one of the two unfiltered stool suspensions used in the pool which had induced gastroenteritis in each of the three volunteers to whom it was fed. Three sets of eggs were inoculated: one on the chorioallantoic membrane, another into the yolk sac, and a third into the amniotic sac. Three serial passages were carried out by each method at varying time intervals. Penicillin and streptomycin were employed as antibacterial agents. Tissue and extraembryonic fluids from the third passage were non-infective for volunteers. PMID- 19871688 TI - THE DEMONSTRATION OF ONE-STEP GROWTH CURVES OF INFLUENZA VIRUSES THROUGH THE BLOCKING EFFECT OF IRRADIATED VIRUS ON FURTHER INFECTION. AB - After allantoic injection of chick embryos with a known amount of influenza virus, the process of adsorption of the agent onto host cells and infection of them can be interrupted at a given time by the administration of large quantities of heterologous virus inactivated by irradiation. A sudden great increase in the amount of free virus in the allantoic fluid occurring after 6 hours in the case of the PR8 strain, and 9 hours in that of the Lee strain, indicates that the untreated virus associated with the host cells has multiplied. The length of the period preliminary to this increase remains the same even though the concentration of the original inoculum is varied over a wide range. Since administration of the irradiated virus leaves no susceptible host cells, because of the interference phenomenon, and further adsorption of active virus is minimized or entirely prevented, practically the entire new increment of virus can be found in the allantoic fluid and assayed; for every ID(50) adsorbed about 50 ID(50) are released. Homologous irradiated virus, on the other hand, when injected after infection of the allantoic sac, reduces the yield of virus to a more or less considerable extent. Some inhibitory effect can still be observed when the homologous irradiated virus is given several hours after infection. This effect is linked to the virus particle and destroyed by prolonged irradiation. PMID- 19871689 TI - STEPWISE INTRATYPE TRANSFORMATION OF PNEUMOCOCCUS FROM R TO S BY WAY OF A VARIANT INTERMEDIATE IN CAPSULAR POLYSACCHARIDE PRODUCTION. AB - 1. A variant intermediate between the classical R and S forms has been isolated by selective procedures from a rough strain of pneumococcus originally derived from Type II S. 2. The intermediate variant D39/Int53 is avirulent for mice, forms rough colonies, and does not possess a demonstrable capsule. However, it synthesizes SSSII which is immunologically indistinguishable from that produced by fully encapsulated pneumococcus Type II, though in much smaller amount. The polysaccharide is present as a surface component and as it exists in the cell is highly antigenic for rabbits. 3. An extract of the intermediate variant causes the transformation in vitro of an R strain into a variant resembling the intermediate in SSSII production but without any apparent alteration in the colonial characteristics of the R variant. 4. The intermediate variant is convertible in vivo, into a fully encapsulated strain of pneumococcus Type II. Transformation of the intermediate to a heterologous type of pneumococcus (Type III) was unsuccessful. 5. A method is described for the preparation of transforming extracts of pneumococci utilizing the massive growth of the organisms obtained in the presence of a large concentration of glucose. PMID- 19871690 TI - PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION. AB - A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma. Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed. Solutions stored at 4 degrees C. showed no conversion of hemoglobin to methemoglobin over a period of 2(1/2) months; over a 6 month period a small and variable amount of methemoglobin may be formed. PMID- 19871691 TI - PREPARATION OF DRIED HEMOGLOBIN WITHOUT LOSS OF ACTIVITY. AB - The technique for freezing, drying, and preserving in vacuo which is in common use for plasma can be successfully applied to hemoglobin solutions when the hemoglobin is first deoxygenated to the extent of 99.7 per cent or more. In confirmation of Morrison and Hisey, the preliminary deoxygenation of the solution is found necessary to avoid formation of methemoglobin during drying. If a solution of oxyhemoglobin is frozen and dried, 20 to 30 per cent is changed to methemoglobin. Deoxygnated hemoglobin dried and preserved in vacuo retained all its oxygenbinding activity for 180 days, when stored at temperatures from 4 degrees to 30 degrees C. Storage at 38 degrees C. for 92 days, or at 56 degrees for 7 days, caused no loss in activity. The dried hemoglobin had a foam structure which caused it to dissolve immediately upon contact with water. Deoxygnated hemoglobin in the dry state was partly converted to methemoglobin by even momentary contact with oxygen. When, however, the deoxygnated hemoglobin was dissolved before it was exposed to air, the hemoglobin in solution was relatively stable, and could be stored for months at 4 degrees in contact with air without significant loss of activity. PMID- 19871692 TI - RENAL EFFECTS OF HEMOGLOBIN INFUSIONS IN DOGS IN HEMORRHAGIC SHOCK. AB - The immediate effects of treating hemorrhagic shock in dogs by replacing lost blood with 7 per cent hemoglobin solution were favorable, both on renal function and on general condition. However, subsequent transitory depression of the urea clearance for several days, shown by some of the treated animals, but not by untreated bled controls, indicates sufficient possibility of renal damage by the hemoglobin solution to prevent its recommendation at present as a blood substitute. PMID- 19871693 TI - STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : X. ANTIBODIES INDUCING IMMEDIATE-TYPE SKIN REACTIONS. AB - Evidence is presented to show that guinea pigs actively sensitized to simple chemical compounds form serum antibodies capable of sensitizing the skin of normal guinea pigs. Skin sites prepared as for the Prausnitz-Kustner test develop immediate-type ("evanescent") reactions with erythema and edema, upon subsequent injection of the corresponding simple compounds or protein conjugates thereof, and give effects resembling transferred reaginic reactions as seen in human beings. The antibodies were obtainable after sensitization by acyl chlorides, acid anhydrides, and also substances of lesser reactivity, picryl chloride and 2:4 dinitrochlorobenzene, which are human allergens. Observations are reported on the specificity of the antibodies and on various details of the reaction. Like effects result when antiprotein immune sera and their corresponding antigens are employed for the test, making it highly probable that the antibodies secured after sensitization to drugs result from immunization by conjugates formed in vivo. The sera obtained after sensitization with simple chemical compounds readily confer passive anaphylaxis, and their capacity for sensitizing the skin declines gradually with progressive heating. It was observed that following a reaction of substantial degree in guinea pig skin the area involved does not fully recover for some days its capacity to react, the effect being a manifestation, it would seem, of what has been termed "non-specific antianaphylaxis." PMID- 19871694 TI - PREPARATION FROM HUMAN RED CELLS OF A SUBSTANCE INHIBITING VIRUS HEMAGGLUTINATION. AB - Methods have been described for the extraction and purification of an agent inhibiting the hemagglutination of red cells by influenza (PR8) and mumps viruses. Human red cells have served as the chief source of the inhibitor but the latter has also been found in human lung. The active extracts have been purified to the extent that 0.1 gamma of material suffices to inhibit one hemagglutinating dose of virus. Incomplete chemical characterization of the most highly purified fractions available indicates the presence of 2.6 per cent nitrogen, at least 50 per cent of polysaccharide, and no phosphorus. In the ultracentrifuge the purified preparation behaves as a polydisperse macromolecular substance. The active material can be obtained from red cell stroma in an ether- and chloroform soluble form which, on further treatment, can be converted into chloroform insoluble material. It is possible that the former represents more closely the virus receptor as it exists in the red cell. The purified inhibitor is inactivated on incubation with the virus at 37 degrees C. The nature of this effect is being investigated. PMID- 19871695 TI - STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT : III. CARRIAGE OF THE VIRUS-LIKE AGENT BY YOUNG RATS AND IN RELATION TO SUSCEPTIBILITY. AB - An attempt was made to reestablish the virus-like agent associated with rat pneumonia by the nasal instillation of the infectious material into supposedly normal young rats from the selected Princeton colony. The incidence of the pneumonia in these animals after the injection of suspensions of pneumonic lungs from either rats or mice was not significantly greater than the incidence under natural conditions. In attempting to account for the refractory state of the immature rats it was found that the agent was widely dispersed through the breeding colony at an early age. Detailed tests of many litters indicated that the agent was acquired shortly after birth by way of the upper air passages as the result of maternal contact. In most instances it was so well tolerated by young rats during the suckling period and for several months thereafter that its presence was recognized only by nasal transfer to mice. There is every indication that the rate of infection of rats in the breeding colony approaches 100 per cent by the time the animals are old enough to be used experimentally. PMID- 19871696 TI - STUDIES OF THE DISTRIBUTION OF POLIOMYELITIS VIRUS : V. THE VIRUS IN FAMILIAL ASSOCIATES OF CASES. AB - The occurrence and duration of the carrier state in familial associates of recognized cases of poliomyelitis was studied by the examination for virus of stool specimens collected from the members of four families at regular intervals for a period of over 2 months. The results indicate that: (1) virus may persist in their stools continuously for 4 to 5 weeks; (2) virus may be encountered intermittently in the stools; (3) in some instances virus may be present for brief periods only; (4) children are more likely to maintain virus than are adults in the same family; (5) infection of a family takes place rapidly, suggesting again simultaneous infection from a common source. PMID- 19871697 TI - STUDIES ON PLANT HYPERTENSINASE. AB - Many plants contain an enzyme similar in most biological properties to the hypertensinase obtained from blood and some animal tissues, notably kidney and intestinal mucosa. Wheat bran is a rich source of the plant hypertensinase, and from it a potent, non-toxic preparation was made by the use of isoelectric and ammonium sulfate precipitation as the means of purification. Hypertensinase derived from bran and administered intramuscularly was not absorbed, or was absorbed only very slowly, into the blood plasma. Repeated intramuscular injection of large quantities of plant hypertensinase did not reduce the blood pressure of dogs with experimental renal hypertension. The intravenous injection of large quantities of plant hypertensinase into dogs resulted in an immediate increase in the content of hypertensinase in the plasma. Dogs with a high hypertensinase level in the plasma failed to react, or reacted much less markedly to the intravenous injection of amounts of renin or hypertensin which had previously proved effective. The slow intravenous injection of plant hypertensinase into a dog with experimental renal hypertension reduced the blood pressure to the normal level for the period during which the concentration of plant hypertensinase in the blood was considerably elevated. After the return of the hypertensinase of the plasma to normal, the blood pressure rose again to its previously high level. Inactivated plant hypertensinase did not increase the hypertensinase content of the plasma, did not interfere with the action of renin and hypertensin, and did not reduce the high blood pressure of dogs with experimental renal hypertension. In a dog with an increased level of plasma hypertensinase, the pressor substance hypertensin could still be detected in the systemic blood immediately after the intravenous injection of renin in an amount to which the animal responded with only a slight rise in blood pressure. PMID- 19871698 TI - STUDIES IN THE RELATION OF THE HEMOLYTIC STREPTOCOCCUS TO RHEUMATIC FEVER : II. FRACTIONATION OF THE HEMOLYTIC STREPTOCOCCUS BY HIGH SPEED CENTRIFUGATION. AB - AFTER DISINTEGRATION BY SONIC VIBRATIONS THE CONTENTS OF THE HEMOLYTIC STREPTOCOCCUS CAN BE SEPARATED BY DIFFERENTIAL CENTRIFUGATION INTO THREE FRACTIONS: an insoluble residue, cytoplasmic particles, and a solution of proteins of smaller unit size. The residue (R) presumably comprises the cell walls of the bacteria and contains the type-specific M protein. The cytoplasmic particles (CP) contain some lipoid, the group-specific carbohydrate, and nucleoprotein of the ribose type. The supernate fraction (S) contains two components, presumably protein, at least one of which is part of a dissociable nucleoprotein of the desoxyribose type. Both CP and S precipitate and fix complement with antistreptococcal sera. Both give rise to antibodies on injection into rabbits. Both are of broad reactivity. CP and S can be shown to be serologically distinct by several means, including cross-absorption tests. On continued disintegration of the organism an inverse relation is noted between the yield of R and that of CP, whereas the yield of S is constant. A theory as to the structure of the streptococcal cell is offered in terms of the data presented. PMID- 19871699 TI - STUDIES IN THE RELATION OF THE HEMOLYTIC STREPTOCOCCUS TO RHEUMATIC FEVER : III. COMPLEMENT FIXATION VERSUS STREPTOCOCCAL NUCLEOPROTEINS WITH THE SERA OF PATIENTS WITH RHEUMATIC FEVER AND OTHERS. AB - Complement-fixing antibodies to the cytoplasmic particles (CP) and to the S fraction of streptococcal nucleoproteins are present in normal human sera, the range of concentrations varying among the age groups. The titer of these antibodies rises between the first half-week and the 3rd week of scarlet fever, in more than 80 per cent of the cases. The titers then remain elevated for at least 4 months. In children, 91 per cent of the normal sera examined showed anti CP titers up to 32; 87 per cent of sera in active rheumatic disease had titers above this level. Corresponding data with S fell in the same range of percentage distribution. Anti-CP and anti-S titers remained elevated long after the rheumatic process had reached quiescence. No correlation of serologic titer with the degree of clinical activity was found in the case of either antibody. PMID- 19871700 TI - HEPARINEMIA (?) : AN ANTICOAGULANT IN THE BLOOD OF DOGS WITH HEMORRHAGIC TENDENCY AFTER TOTAL BODY EXPOSURE TO ROENTGEN RAYS. AB - When the entire body of dogs was exposed to 450 units of Roentgen irradiation a hemorrhagic syndrome developed which was characterized by thrombo-cytopenia, prolonged clotting and bleeding times, and neutropenia. The prothrombin time remained normal until about 24 hours before death. The calcium, phosphorus, and magnesium levels were not altered. Fibrinogen was present but syneresis was poor. Toluidine blue and protamine sulfate, substances which can inhibit the biologic action of heparin, restored the clotting time to normal. The hemorrhagic state was not materially altered by transfusions, vitamin K, or vitamin C. Toluidine blue and protamine sulfate were ineffective in the control of hemorrhage produced by dicumarol. The defect responsible for bleeding after irradiation appeared to be the presence in the circulation of an anticoagulant whose properties, so far as tested, were indistinguishable from those of heparin. PMID- 19871701 TI - A MURINE VIRUS (JHM) CAUSING DISSEMINATED ENCEPHALOMYELITIS WITH EXTENSIVE DESTRUCTION OF MYELIN : II. PATHOLOGY. AB - A description has been given of the pathologic changes produced experimentally in animals by the inoculation of a virus material obtained from a mouse with spontaneous encephalomyelitis. The most distinctive feature of the lesions in the central nervous system is the widespread destruction of myelin. Giant cells derived from a variety of tissue elements characterize the early lesions. The liver in the majority of cases is the seat of focal necrosis. In some mice, infected with large doses by the intravenous route, there is produced massive necrosis of the liver, with fat infiltration and calcification. Giant cells are occasionally found in lymphatic tissue, but no significant changes were noted in other organs. Inclusions or elementary bodies were not demonstrated in the lesions. Similar lesions were produced by the inoculation of mouse virus into hamsters. In rats, the lesions were of a more chronic character. The relation of this disease to other demyelinating diseases of man and animals is discussed. PMID- 19871702 TI - PULMONARY EDEMA IN INFLUENZAL PNEUMONIA OF THE MOUSE AND THE RELATION OF FLUID IN THE LUNG TO THE INCEPTION OF PNEUMOCOCCAL PNEUMONIA. AB - Pulmonary edema is a component of the fully developed influenza viral lesion in the mouse. Mice with experimental pulmonary fluid have an increased susceptibility to inhaled pneumococci and under these circumstances the organisms grow in the lung and produce the lesion of bacterial pneumonia. The presence of pulmonary edema in the lesion due to the influenza virus in the lung of the mouse appears to account adequately for the previous observation that inhaled pneumococci grow in the influenza viral lesion. Mice dying of pneumococcal septicemia after inhaling fine droplets containing this organism do not have pneumonia. The delay in migration of polymorphonuclear leucocytes into the lung after injection of pneumococci suspended in serum is an important factor in susceptibility to infection since it allows ample time for pneumococci to grow in the pulmonary fluid. The slow phagocytic action of pulmonary macrophages likewise permits growth of pneumococci. Conditions in human beings that are known to be complicated by pulmonary edema are also known to be associated with increased susceptibility to secondary bacterial pneumonia. PMID- 19871703 TI - PRODUCTION OF BCG VACCINE IN A LIQUID MEDIUM CONTAINING TWEEN 80 AND A SOLUBLE FRACTION OF HEATED HUMAN SERUM : I. PRODUCTION AND VIABILITY OF THE CULTURE. AB - Diffuse, submerged growth of BCG bacilli has been obtained in liquid media containing 0.02 per cent Tween 80 and the soluble fraction of human serum heated under acid conditions (pH 2.5) at 65 degrees C. In the absence of glucose or glycerine,-which had a detrimental effect on viability-these cultures consisted predominantly of cells that were living and that remained viable during prolonged storage at temperatures ranging from 4 to 37 degrees C. PMID- 19871704 TI - PRODUCTION OF BCG VACCINE IN A LIQUID MEDIUM CONTAINING TWEEN 80 AND A SOLUBLE FRACTION OF HEATED HUMAN SERUM : II. ANTIGENICITY OF THE CULTURE AFTER VARIOUS PERIODS OF STORAGE. AB - Groups of guinea pigs were vaccinated by the intracutaneous route with cultures of BCG grown in a liquid medium containing Tween 80 and the soluble fraction of heated human serum. After the cultures had been stored at 4 degrees C. for various periods of time, the antigenic response was compared with that of another group of guinea pigs receiving standard BCG vaccine prepared by the conventional technique. The local lesions occurring at the site of injection of cultures in Tween-serum filtrate medium were more severe than those produced by the standard vaccine. It was shown that this difference was probably due to the much larger number of viable bacilli in the former preparations. A marked degree of sensitization could be produced with culture dilutions containing as few as 10 viable units (single bacilli or small clumps). Slightly larger doses of BCG led to the highest degree of tuberculin allergy detectable by the technique employed. Further increases in the dose of vaccine failed to alter the level of sensibility when the animals were tested with tuberculin 5 weeks after vaccination. The same degree of sensitization was achieved by vaccination with 0.1 cc. of either the standard vaccine or any of the fresh or stored cultures in Tween-serum filtrate medium. It was shown that these doses contained numbers of living bacilli far greater than the minimal number required to induce maximal sensitization. Under the conditions used, the guinea pigs vaccinated with cultures of BCG (fresh or stored) grown in the Tween-serum filtrate medium exhibited a marked degree of resistance to subcutaneous infection with virulent tubercle bacilli. PMID- 19871705 TI - THE EFFECT OF INJURY BY TOXIC AGENTS UPON OSMOTIC PRESSURE MAINTAINED BY CELLS OF LIVER AND OF KIDNEY. AB - As shown in a previous paper the cells of the liver and of the kidney maintain an osmotic pressure approximately twice that of blood and of erythrocytes, exceeding this slightly in the case of liver and being slightly less in that of kidney. When liver cells are injured by chloroform or by carbon tetrachloride the osmotic pressure they maintain falls to the level of the medium that surrounds them but is promptly restored when recovery from the injury, with some regeneration of liver cells, occurs. When nephrosis is caused by potassium chromate or by chloroform the osmotic pressure maintained by parenchymatous cells of the renal cortex falls to that of the medium about them but returns to its normal level with recovery from the injury. PMID- 19871706 TI - SPECIFIC COAGULASES OF STAPHYLOCOCCUS AUREUS. AB - Three staphylococcal coagulases termed I, II, and III were differentiated by measuring the antibody titer of human sera. Coagulases I and II are antigenically distinct; coagulase III appears to be related to both coagulases I and II. These results were confirmed by specific neutralization experiments. These observations emphasize the importance of employing the correct type of coagulase in studying the role of this substance in the pathogenesis of staphylococcal infections. Preliminary observations in animals indicate that specific anticoagulase develops following induced infections. The role of this antibody in the recovery mechanism remains to be determined. PMID- 19871707 TI - ASSOCIATION OF A SPECIAL STRAIN OF PLEUROPNEUMONIA-LIKE ORGANISMS WITH CONJUNCTIVITIS IN A MOUSE COLONY. AB - An outbreak of conjunctivitis, unaccompanied by involvement of the respiratory tract, is reported in a colony of white mice. A special strain of pleuropneumonia like organisms was regularly isolated from the eyes and nasal passages of affected mice but not from the lungs or middle ears. Ocular carriage of these organisms in the absence of an inflammatory reaction occurred in at least 50 per cent of the adult mice. Transmission to the young was presumably initiated by parental contact, the organisms being recoverable after the eyes were open, and was continued after weaning by direct contact between cage mates. These organisms were repeatedly established on the conjunctiva of normal Swiss mice by direct contact with infected animals and subsequently maintained there for ten successive passages. Multiplication of the pleuropneumonia-like organisms, which was largely limited to the eye and its appendages, was accompanied by a low rate of conjunctivitis. The multiple conjunctival instillation of ocular washings from infected mice was the only additional method of implantation of the organisms which was successful. PMID- 19871708 TI - INFLUENZA : I. THE HEMAGGLUTINATION AND INFECTIVITY TITRE CURVES OF PR8 INFLUENZA VIRUS CULTIVATED IN EMBRYONATED EGGS AT DIFFERENT TEMPERATURES. AB - Groups of embryonated eggs infected with the PR8 strain of influenza virus A were incubated at 34 degrees , 37.5 degrees , and 40 degrees C. At frequent intervals, for periods ranging up to 96 hours, pooled allantoic fluids were tested simultaneously for infectivity and hemagglutination. After about 12 hours of virus growth, fluids often showed infectivity titres greater than 10(-5), but were incapable of causing hemagglutination. At later time intervals, marked disagreement between the two tests for viral activity was noted at all temperatures, but most strikingly at 40 degrees C. Hemagglutination titres were highest and best sustained in eggs incubated at 34 degrees C., while incubation at 37.5 degrees C. resulted in the highest and best sustained infectivity titres. Hemagglutination titre determinations do not reflect accurately the rate of influenza virus multiplication. Possible reasons for the lack of correspondence between hemagglutination and infectivity are discussed. PMID- 19871709 TI - INFLUENZA : II. EFFECT OF INFLUENZA VIRUS MULTIPLICATION ON THE OXYGEN CONSUMPTION CURVES OF EMBRYONATED EGGS INCUBATED AT DIFFERENT TEMPERATURES. AB - In addition to the cycles of growth shown by the influenza A virus during the first 24 hours of its residence in the fertile egg, cycles separated by longer time intervals have been noted between the 24th and 96th hours. These longer cycles are best seen when the eggs are incubated at 40 degrees C. Corresponding fairly accurately with these cycles of growth of the virus, wide cyclic variations in the rates of increase in oxygen consumption of the infected eggs have been found to occur. These variations are in striking contrast to the uniformity of increase noted in uninfected eggs. The variations in infectivity may be caused by periodic interference with virus multiplication by accumulated inactive virus particles. The variations in oxygen consumption probably are correlated with variations in the concentration of virus toxins. PMID- 19871710 TI - INFLUENZA : III. RAPID ALTERATIONS IN THE RESPIRATORY RATE OF EMBRYONATED EGGS APPARENTLY CAUSED BY INFLUENZA VIRUS TOXIN. AB - Allantoic fluid from embryonated eggs infected with influenza A virus contains a toxic agent which can be demonstrated and quantitatively measured by its rapid effect on oxygen consumption when it is introduced in new series of fertile eggs. The effects were measured 90 minutes after the injection of the infected fluid, and were seen following both intra-allantoic injection and injection into the yolk sac. This toxin, in concentrations resulting from the injection of 0.5 cc. or less of the infected fluid, has no effect on oxygen consumption. The injection of 0.75 to 2.0 cc. of the fluid strikingly increases the oxygen consumption of the fertile eggs, while the injection of 3.0 cc. markedly depresses respiration. A similar reversal and eventual loss of the effect of the toxin on respiration were noted when the concentration of toxin was progressively diminished by heat inactivation. The toxic agent is slowly inactivated by heating at 56 degrees C., but is effective long after infectivity and hemagglutinating ability have been destroyed. In this respect the agent differs from rickettsial and lymphogranuloma venereum virus toxins. The method described may be of value in studying the physiological effects of other toxic agents. PMID- 19871711 TI - IMPROVED METHODS FOR THE PREPARATION OF THE SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS. AB - The specific polysaccharides of Types I and V pneumococcus give sharp equivalence zones and show maximal precipitation with homologous rabbit antisera only when carefully prepared from cultures which have not been neutralized with alkali. The precipitating power of S V toward homologous rabbit antiserum falls off in 0.1 N NaOH even more rapidly than that of S I, dropping to 7 per cent of the original value in 6 days at room temperature. The alkaline solution develops a large absorption peak at 270 mmicro. Directions are given for the preparation of S VII and S XII. PMID- 19871712 TI - THE ABNORMAL COURSE OF BACTERIAL PROTEIN SYNTHESIS IN THE PRESENCE OF PENICILLIN. AB - Washed staphylococcal cells separated from peptone-broth cultures containing penicillin G did not differ markedly from cells not exposed to penicillin in their rate of oxygen, phosphate, glutamic acid, or amino nitrogen utilization. Washed normal staphyloccal cells, respiring in solutions containing glucose and various mixtures of amino acids, utilized the amino acids with an increase in the cellular protein nitrogen. Similar cells under the same conditions, but exposed to penicillin G, utilized oxygen, phosphate, and amino acids at essentially the same rates, but there was no increase in the protein nitrogen of the cells. Penicillin-treated washed cells, when utilizing amino acids, produced increased amounts of extracellular substances containing non-amino nitrogen in quantities approximately equivalent to the amino acid nitrogen utilized. The non-amino fraction could be tentatively identified as polypeptide, which was produced, instead of cellular protein, when penicillin was present. PMID- 19871713 TI - FACTORS IN PLASMA CONCERNED IN NATURAL RESISTANCE TO AN AVIAN MALARIA PARASITE (PLASMODIUM LOPHURAE). AB - The plasma of adult chickens, when injected into young chicks or chick embryos infected with Plasmodium lophurae, lessened the parasitemia. The substances responsible for this effect were inactivated or removed by the heating of adult chicken plasma for (1/2) hour at 65 degrees C., followed by centrifugation to remove the coagulated material; but they were not affected by heating for (1/2) hour at 56 degrees C. The active materials were present in the euglobulin fraction of hen plasma. In similar experiments with ducks, the plasma from each of a series of adult ducks was tested for its effect on the course of infection in young ducklings. The adult ducks were then inoculated with a large dose of parasites. There was a positive correlation between the effectiveness of a plasma in lessening the parasitemia of ducklings treated with it and the resistance on infection exhibited by the duck from which the plasma had been obtained. More than half of the adult female ducks with an active ovary which were tested, but only one of the males, had effective plasmas and also showed relative resistance to the infection. PMID- 19871714 TI - THE EFFECT OF TUBERCLE BACILLI ON THE POLYMORPHONUCLEAR LEUCOCYTES OF NORMAL ANIMALS. AB - A description is given of a slide cell whereby the rate of migration of very small amounts of leucocytes can be followed and measured. The migration of polymorphonuclear leucocytes was found to be inhibited by virulent tubercle bacilli pathogenic for the class of animal (mammal or bird) from which the leucocytes were obtained; it was not affected by the avirulent variants of these microorganisms, or by bacilli pathogenic for animals of the other class. Tests failed to disclose that the inhibition of leucocytic migration resulted from any gross damage caused by the bacilli to the leucocytes. PMID- 19871715 TI - STUDIES OF THE HEMOLYSIS OF RED BLOOD CELLS BY MUMPS VIRUS : I. THE DEVELOPMENT OF MUMPS VIRUS HEMOLYSIN AND ITS INACTIVATION BY CERTAIN PHYSICAL AND CHEMICAL AGENTS. AB - The conditions for the production of extra-embryonic fluids with hemolytic activity from chick embryos infected with mumps virus have been investigated. Infected fluids with strong hemolytic activity can be obtained by harvesting the fluids of 6- to 8-day-old chick embryos inoculated by the amniotic route after 5 to 6 days' incubation at 35 degrees C. Under such circumstances, the hemolytic capacity of amniotic fluids is usually much higher than that of the allantoic fluids. The hemolytic activity and infectivity of the virus have been found to be reduced or destroyed by heat, formaldehyde, and ultraviolet irradiation under conditions which leave the hemagglutinating capacity practically unchanged. Ultraviolet irradiation appeared to have a greater deleterious effect on the infectivity of the virus than on its hemolytic capacity. The marked reduction or destruction of hemolytic activity of the virus produced by certain treatments with these various agencies was not accompanied by loss of the ability of the virus to elute following its adsorption on red blood cells during the process of hemagglutination. This test for hemolytic activity, which measures a more labile property of the virus than do determinations of virus hemagglutination or virus elution, may be useful in detecting changes which occur early during degradation of the virus. PMID- 19871716 TI - STUDIES OF THE HEMOLYSIS OF RED BLOOD CELLS BY MUMPS VIRUS : II. THE RELATIONSHIPS OF HEMAGGLUTINATION, VIRUS ELUTION, AND HEMOLYSIS. AB - The relationship between hemagglutination and hemolysis by the mumps virus has been studied under conditions which affect (a) the receptors of chicken red cells and (b) the adsorption and subsequent elution of the virus from these cells. The results show that the hemolytic action of the virus appears to involve some of the same receptor areas of erythrocytes that are implicated in hemagglutination. Materials such as allantoic fluid, egg white, and red cell extract, which inhibit the agglutination of chicken red cells by mumps virus, also interfere with its hemolytic activity. Of these inhibitors, egg white and red cell extract, which are readily destroyed by the virus during incubation at 37 degrees C., exert a greater antagonistic effect on hemagglutination than on hemolysis. Heated mumps virus or unheated influenza virus interferes with the hemolysis of red cells by untreated mumps virus. Though hemolysis takes place during elution of the virus after its adsorption on the red cell, the processes are apparently distinct. The hemolytic activity is easily affected by certain conditions of pH and temperature which have no effect on the ability of mumps virus to adsorb on and elute from red cells. PMID- 19871717 TI - STUDIES ON THE ENTRY AND EGRESS OF POLIOMYELITIC INFECTION : I. NEUTROTROPIC INFECTION OF THE PERIPHERAL GANGLIA IN APPARENTLY HEALTHY MONKEYS FOLLOWING CASUAL EXPOSURE. AB - In rhesus and cynomolgus monkeys without signs or symptoms of poliomyelitis, a comparison of the incidence, numbers, size, and character of lesions in certain peripheral ganglia (gasserian, nodose, superior cervical sympathetic, and celiac) was made between 9 "new" animals sacrificed 1 to 3 days after arrival in a laboratory devoted exclusively to poliomyelitis research, and 17 "old" animals housed there without special isolation precautions for periods ranging from 17 days to 10(1/2) months. The comparison showed that the "old" animals had more infiltrative lesions of various sizes than the "new" and that neuronophagia occurred in 65 per cent of the "old" animals as compared with none in the "new." The heaviest and most frequent involvement occurred in the gasserian and superior cervical sympathetic ganglia, while that of the nodose (vagal afferent) ganglia was somewhat less, and that of the celiac ganglia was still less and without neurophagia. The ganglia of the VII and IX cranial nerves were also examined and showed no lesions of note. Reasons are presented for believing that the lesions were of centripetal and not of centrifugal origin. The lesions, while not positively identified as poliomyelitic, were of similar morphology, were presumably due to an infective neurotropic agent, and were acquired under conditions of potential exposure to poliomyelitis virus. The possibility is suggested that the asymptomatic acquisition of neurotropic lesions in this group of casually exposed monkeys can be comparable to the acquisition of "subclinical" poliomyelitis in man. PMID- 19871718 TI - RECIPROCAL CHANGES IN PLASMA PROTEIN AND PLASMA ACACIA AS RESULT OF HIGH AND LOW PROTEIN DIETS. AB - Dogs were made hypoproteinemic by repeated injections of gum acacia, and the acacia injections were discontinued. Diets of varying protein content were then given. When a high protein diet is provided the plasma protein concentration increases; with a low protein diet, or under conditions of fasting, the plasma protein concentration diminishes. Similarly, plasma acacia concentration shows increases and decreases which are reciprocal to the protein variations. Total circulating plasma protein and total circulating plasma acacia show similar changes. In all instances total circulating colloid (acacia plus protein) concentration adds up to an amount within normal limits for protein alone. The results indicate that under these conditions, acacia stored in the body (principally in the liver) can be removed from its site of deposit and returned to the blood. The data also show that dogs in which acacia is deposited in large quantities, require a larger amount of protein in the diet to maintain a constant plasma protein content than do normal dogs. It appears that the mechanism for maintenance of peripheral colloidal material may be dependent on differences in intracellular and extracellular colloidal osmotic pressure. The experiments also support the idea that plasma protein molecules, as well as gum acacia, may pass in and out of cells through the cell membranes. PMID- 19871719 TI - IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : XI. SPECIES DIFFERENCES AMONG BLOOD GROUP A SUBSTANCES. AB - The reactions of hog, human, and horse blood group A substances with antibodies produced on injection of these substances into individuals of blood groups B and O have been studied by hemagglutination inhibition and by quantitative precipitin technics. Species differences in reactivity with antisera exist among these blood group A substances. Hog and human A substances are very closely related chemically as evidenced by their extensive cross-reaction while horse A substance crossreacts much less with antisera to both hog and human A substances. Analysis for hexosamine of specific precipitates of hog and human A substances and antibody to human A substance formed as a consequence of heterospecific pregnancy has shown that essentially all of the glucosamine of the blood group substance is precipitated. PMID- 19871720 TI - ON THE DYNAMICS OF PHOTOSYNTHESIS. AB - Minute amounts of photosynthesis in marine plants can be accurately measured by adding a little phenolphthalein to the sea water, and observing changes in the color of the indicator. In the case of fresh water aquatics bicarbonates are added. By this method it is found that Ulva which has been kept in the dark begins photosynthesis as soon as it is exposed to sunlight and that the rate steadily increases until a constant speed is attained. This may be explained by assuming that sunlight decomposes a substance whose products either catalyze photosynthesis or enter directly into the reaction. Quantitative theories are developed in order to account for the facts. PMID- 19871721 TI - LIGHT AND THE MUSCLE TONUS OF INSECTS THE HELIOTROPIC MECHANISM. AB - The tonus of the muscles of heliotropic insects is due chiefly to the action of light; it is markedly decreased in the dark. Each eye controls the tonus of a different group of muscles on both sides of the body. Different areas of each eye likewise are related to the tonus of different muscle groups, and the relationship is entirely analogous to that of the otic labyrinth of vertebrates. Asymmetrical conditions of muscle tension are produced by any procedure which establishes an unequal photochemical reaction in the two eyes, by difference in illumination, by partial or complete blackening of one eye, or establishing unequal sensitiveness in the two eyes. The unbalanced condition of muscle tonus expresses itself in unusual postures of the resting insects, and in movements in forced paths-circus motions when one eye has been blackened. These reactions vary directly with the intensity of the illumination, as shown not only by the variation in diameters of the circles, but also by the reactions of the insects on vertical surfaces and on the turntable. The relation of the results of these experiments to the problem of heliotropic orientation is too obvious to require detailed discussion, which could only lead to a repetition of the description of the mechanism f heliotropism which Loeb has so clearly expounded. The experiments are so completely in accordance with Loeb's muscle tension theory of heliotropism, that they are tantamount to a complete proof of it. PMID- 19871722 TI - LUTEAR CELLS AND HEN-FEATHERING. AB - The experimental evidence had made clear that some substance is produced in the testis of the male Sebright that suppresses in him the development of the secondary sexual plumage of the cock of his species. The detection in his testis of lutear cells like those in hens makes the conclusion highly probable that it is these cells that cause the suppression of cock-feathering in both the Sebright male and in hens of all fowls. Genetic work by Morgan had shown that one or two Mendelian factor-differences are responsible for hen-feathering in the Sebright. These factor-differences produce their effects through the testes. The presence of these genetic factors, we now see, causes the testes of the Sebright to produce a kind of secretory cell that is ordinarily only produced in the female, or possibly to a slight extent in young males (Boring), or in numbers insufficient to suppress the male plumage in the testes of some ordinary cock birds (Reeves). PMID- 19871723 TI - A METHOD OF STUDYING RESPIRATION. AB - An apparatus is described which makes it possible to measure rapidly and accurately small amounts of CO(2) given off by organisms of all kinds. The apparatus can also be used to measure photosynthesis. PMID- 19871724 TI - THE ANTAGONISM BETWEEN THYROID AND PARATHYROID GLANDS. AB - From the facts stated in this paper it is evident that the thymus gland of mammals contains a substance which is capable of producing tetany when fed to the larvae of certain species of salamanders (Ambystoma opacum and Ambystoma maculatum). As long as the larvae have not developed their own thymus glands, they are able, by means of some mechanism, to counterbalance the tetanic action of the thymus substance introduced in their food. When, however, the secretion from their own thymus glands is added to the thymus material introduced with the food, this mechanism of preventing tetany becomes inadequate and tetany ensues. In the larva of a third species of salamander, Ambystoma tigrinum, this mechanism will prevent tetany even when the larvae are fed on thymus. In mammals the parathyroids are known to prevent tetany and are supposed either to absorb the tetany-producing substance and thus prevent its action or to change it into another non-toxic substance. It is at least probable that in the amphibians the parathyroids play the same role. Larvae of anuran amphibians, which develop their parathyroids soon after hatching, never show tetanic convulsions if they are fed on thymus, but in certain species of salamanders, whose parathyroids develop only during metamorphosis, the larvae invariably have tetanic convulsions upon thymus feeding, while the metamorphosed animals never show tetany. But in addition to the parathyroids the salamanders must possess still another mechanism which during the larval period inhibits the production of tetany by the animal's own thymus glands. In the larvae of Ambystoma opacum and Ambystoma maculatum this mechanism is sufficient only to prevent tetany from the animal's own thymus, while in the larvae of Ambystoma tigrinum it is capable of preventing tetany even when the larvae are fed with thymus. If the thymus is the organ by whose action tetany is produced, we can understand why tetany in human beings occurs far more frequently in children than in adults, since in the latter the thymus gland is replaced, at least to a great extent, by connective tissue. The relation of thymus to tetany may also possibly explain the occurrence of tetany during pregnancy; while the parathyroids of the mother may be sufficient to prevent tetany from her largely atrophied thymus, they may not be sufficient to prevent tetany from the excess of thymus substance furnished by the fetus to the blood of the mother. PMID- 19871725 TI - FURTHER PROOF OF THE EXISTENCE OF A SPECIFIC TETANY-PRODUCING SUBSTANCE IN THE THYMUS GLAND. AB - The effect of the thymus gland in producing tetany is due to a specific tetany toxin produced by and contained in the thymus, and the thymus gland must be added to the group of glands for which the function of internal secretion has been demonstrated. PMID- 19871726 TI - DIFFERENCE IN THE ACTION OF RADIUM ON GREEN PLANTS IN THE PRESENCE AND ABSENCE OF LIGHT. PMID- 19871727 TI - AMPHOTERIC COLLOIDS : I. CHEMICAL INFLUENCE OF THE HYDROGEN ION CONCENTRATION. AB - 1. It has been shown in this paper that while non-ionized gelatin may exist in gelatin solutions on both sides of the isoelectric point (which lies for gelatin at a hydrogen ion concentration of C(H) = 2.10(-5) or pH = 4.7), gelatin, when it ionizes, can only exist as an anion on the less acid side of its isoelectric point (pH > 4.7), as a cation only on the more acid side of its isoelectric point (pH < 4.7). At the isoelectric point gelatin can dissociate practically neither as anion nor as cation. 2. When gelatin has been transformed into sodium gelatinate by treating it for some time with M/32 NaOH, and when it is subsequently treated with HCl, the gelatin shows on the more acid side of the isoelectric point effects of the acid treatment only; while the effects of the alkali treatment disappear completely, showing that the negative gelatin ions formed by the previous treatment with alkali can no longer exist in a solution with a pH < 4.7. When gelatin is first treated with acid and afterwards with alkali on the alkaline side of the isoelectric point only the effects of the alkali treatment are noticeable. 3. On the acid side of the isoelectric point amphoteric electrolytes can only combine with the anions of neutral salts, on the less acid side of their isoelectric point only with cations; and at the isoelectric point neither with the anion nor cation of a neutral salt. This harmonizes with the statement made in the first paragraph, and the experimental results on the effect of neutral salts on gelatin published in the writer's previous papers. 4. The reason for this influence of the hydrogen ion concentration on the stability of the two forms of ionization possible for an amphoteric electrolyte is at present unknown. We might think of the possibility of changes in the configuration or constitution of the gelatin molecule whereby ionized gelatin can exist only as an anion on the alkaline side and as a cation on the acid side of its isoelectric point. 5. The literature of colloid chemistry contains numerous statements which if true would mean that the anions of neutral salts act on gelatin on the alkaline side of the isoelectric point, e.g. the alleged effect of the Hofmeister series of anions on the swelling and osmotic pressure of common gelatin in neutral solutions, and the statement that both ions of a neutral salt influence a protein simultaneously. The writer has shown in previous publications that these statements are contrary to fact and based on erroneous methods of work. Our present paper shows that these claims of colloid chemists are also theoretically impossible. 6. In addition to other physical properties the conductivity of gelatin previously treated with acids has been investigated and plotted, and it was found that this conductivity is a minimum in the region of the isoelectric point, thus confirming the conclusion that gelatin can apparently not exist in ionized condition at that point. The conductivity rises on either side of the isoelectric point, but not symmetrically for reasons given in the paper. It is shown that the curves for osmotic pressure, viscosity, swelling, and alcohol number run parallel to the curve of the conductivity of gelatin when the gelatin has been treated with acid, supporting the view that these physical properties are in this case mainly or exclusively a function of the degree of ionization of the gelatin or gelatin salt formed. It is pointed out, however, that certain constitutional factors, e.g. the valency of the ion in combination with the gelatin, may alter the physical properties of the gelatin (osmotic pressure, etc.) without apparently altering its conductivity. This point is still under investigation and will be further discussed in a following publication. 7. It is shown that the isoelectric point of an amphoteric electrolyte is not only a point where the physical properties of an ampholyte experience a sharp drop and become a minimum, but that it is also a turning point for the mode of chemical reactions of the ampholyte. It may turn out that this chemical influence of the isoelectric point upon life phenomena overshadows its physical influence. 8. These experiments suggest that the theory of amphoteric colloids is in its general features identical with the theory of inorganic hydroxides (e.g. aluminum hydroxide), whose behavior is adequately understood on the basis of the laws of general chemistry. PMID- 19871728 TI - A THEORY OF THE MECHANISM OF DISINFECTION, HEMOLYSIS, AND SIMILAR PROCESSES. AB - 1. The course of such processes as hemolysis is very largely dependent upon variations in resistance among the different individuals, and secondarily upon the course of the fundamental reaction. 2. The fundamental reaction may be either a simple process, or the expression of a complex series of changes whose rate is at all times governed by that of the slowest of the series. This might perhaps be regarded as another expression of the so called "Law of the minimum." 3. Unnatural assumptions would be requisite for the explanation of a resemblance between the course of such processes in general and that of a monomolecular reaction. 4. The supposition that such a general resemblance exists is not supported by the available evidence. 5. The independent determination of either the nature of the fundamental reaction, or the type of the variation curve for the particular case under observation, will further our knowledge of the nature of such processes and lead to a far deeper insight into the nature and reactions of living matter. PMID- 19871729 TI - THE LAW CONTROLLING THE QUANTITY OF REGENERATION IN THE STEM OF BRYOPHYLLUM CALYCINUM. AB - 1. A method is given which allows us to measure the influence of the mass of a leaf upon the quantity of shoots regenerated in an isolated piece of stem. This method consists in isolating a piece of stem with only two leaves left at the basal node and then splitting the stem lengthwise so that each half has one basal leaf. By leaving one leaf intact while the size of the sister leaf is reduced, the influence of the mass of the leaf upon the quantity of shoots regenerated by the stem can be measured. 2. This method has yielded the result that the mass of shoots regenerated at the apex of such a piece of stem increases under equal conditions and in equal time with the mass of the leaf, and is approximately proportional to the mass of the leaf. 3. Such an influence of the mass of the leaf upon the mass of shoots produced by the stem is only intelligible on the assumption that the growth of the regenerating shoot occurs at the expense of material furnished by the basal leaf. 4. This assumption is supported by two facts: first, that in the dark this influence of the leaf disappears more or less completely; and, second, that a leaf attached to the base of a regenerating stem after some time weighs markedly less than does a sister leaf completely detached from the stem, but otherwise under equal conditions. 5. This latter fact that a leaf when attached to the base of an excised piece of stem wilts more rapidly than when completely isolated is the reason that the proportionality between mass of a basal leaf and mass of shoot regenerated at the apex of an isolated piece of stem cannot always be demonstrated with the same degree of accuracy as the proportionality between the mass of completely isolated leaves and the mass of shoots they produce. 6. The material furnished by the leaf to the stem is not restricted to water but includes also the solutes, since not only the fresh weight but also the dry weight of the shoot regenerated by a piece of stem increases with the mass of the leaf attached to the base of the stem; and since not only the water contents but the dry weight of a leaf attached to the base of an excised piece of stem diminish when compared with the dry weight of a completely detached sister leaf. 7. The mass of shoots produced by an isolated piece of stem without leaf is small and almost negligible compared with the mass of shoots produced by the same piece of stem when a leaf of sufficient mass is attached to the base of the stem. PMID- 19871730 TI - REVERSAL OF REACTION BY MEANS OF STRYCHNINE IN PLANARIANS AND STARFISH. AB - Two cases have been described, that of the marine planarian Bdelloura and that of the starfish Asterias forbesii, in which strychnine reverses reciprocal inhibition. These facts indicate that the nervous systems of these invertebrates function in a manner similar to those of the earthworm and vertebrates. Moreover, it would seem that strychnine acts upon some chemical component of the neuron which is always present in synaptic structures but which also occurs in the simpler neurons of lower forms. The fact that strychnine is without this characteristic effect on such forms as medusa and sea anemone, indicates that the nervous systems of the starfish and planarian have chemical affinities with the vertebrates which the coelenterates do not possess. PMID- 19871731 TI - STUDIES ON BIOLUMINESCENCE : VII. REVERSIBILITY OF THE PHOTOGENIC REACTION IN CYPRIDINA. PMID- 19871732 TI - THE PHOTIC SENSITIVITY OF CIONA INTESTINALIS. AB - 1. Ciona possesses two means of responding to an increase in the intensity of illumination. One is by means of a local reaction; the other is by a retraction reflex of the body as a whole. 2. The "ocelli" are not photoreceptors. The photosensitive area is in the intersiphonal region containing the neural mass. This area contains no pigment. 3. The reaction time to light is composed of a sensitization period during which Ciona must be exposed to the light, and of a latent period during which it need not be illuminated in order to react to the stimulus received during the sensitization period. 4. The duration of the reaction time varies inversely as the intensity. Analysis shows the latent period to be constant. The relation between the sensitization period and the intensity follows the Bunsen-Roscoe rule. 5. During dark adaptation the reaction time is at first large, then it decreases until a constant minimum is reached. 6. A photochemical system consisting of a reversible reaction is suggested in order to account for the phenomena observed. This system includes a photosensitive substance and its precursor, the dynamics of the reaction following closely the peculiarities of the photosensitivity of Ciona. 7. It is shown that in order to produce a reaction, a constant ratio must be reached between the amount of sensitive substance broken down by the stimulus and the amount previously broken down. 8. From the chemical system suggested certain experimental predictions were made. The actual experiments verified these predictions exactly. 9. The results obtained with regularly repeated stimulation not only fail to show any basis for a learning process or for the presence of a "higher behavior," but follow the requirements of the photochemical system suggested before. PMID- 19871733 TI - AN INDICATOR METHOD OF MEASURING THE CONSUMPTION OF OXYGEN. AB - The blood of the horseshoe crab (Limulus) absorbs oxygen and turns blue when shaken in air. In the presence of certain organisms which consume oxygen it is quickly decolorized. By measuring the time required for the change of color the rate of consumption of oxygen may be determined. PMID- 19871734 TI - COMPARATIVE STUDIES ON RESPIRATION : I. INTRODUCTION. AB - A series of investigations on respiration with improved quantitative methods has been commenced. The first of these are here described. They show that when anesthetics are employed in sufficient concentration to produce any result, plants show a rise in the rate of respiration which is followed by a fall. In the animals studied, the rise (found in higher concentrations only) was preceded by a temporary fall which is not entirely due to lowering of muscular activity or tonus. In lower concentrations the effect on animals was merely a decrease of respiration. The results of all the investigations are opposed to the theory of Verworn. PMID- 19871735 TI - COMPARATIVE STUDIES ON RESPIRATION : II. THE EFFECT OF ANESTHETICS AND OTHER SUBSTANCES ON THE RESPIRATION OF ASPERGILLUS NIGER. AB - 1. In concentrations which are high enough to produce any effect, formaldehyde, ether, and acetone cause an increase, followed by a decrease, in the rate of respiration. 2. 3.65 per cent ether, which causes an increase with certain cultures, produces only a decrease with others. 3. The reaction producing an increase in the respiration with 7.3 per cent ether is a reversible process, while the reaction producing the decrease is not reversible. 4. 0.5 per cent caffeine produces only a decrease in respiration while a saturated solution causes an increase, which is followed by a decrease. PMID- 19871736 TI - COMPARATIVE STUDIES ON RESPIRATION : III. THE EFFECT OF ETHER ON THE RESPIRATION AND GROWTH OF BACILLUS SUBTILIS. AB - 1. In all the concentrations of ether studied (from 0.037 to 7.3 per cent) there is an increase in the rate of respiration of Bacillus subtilis followed by a decrease. 2. In 7.3 per cent ether in tap water there is an extraordinary increase in the output of CO(2) (amounting to 50 times the normal). This does not occur when 0.85 per cent NaCl is added, which indicates antagonism between ether and NaCl. 3. Ether is toxic in low concentrations (0.037 to 1.1 per cent) and high concentrations (3.65 to 7.3 per cent) but in intermediate concentrations (1.1 to 3.65 per cent) stimulates growth. PMID- 19871737 TI - COMPARATIVE STUDIES ON RESPIRATION : IV. THE EFFECT OF ETHER ON THE RESPIRATION OF WHEAT. AB - These experiments show that 7.3 and 3.65 per cent ether solutions cause an increase in respiration followed by a decrease. The results agree with those of Haas on Laminaria, of Gustafson on higher fungi, and of Mrs. Brooks on bacteria. They do not agree with the theory of Verworn that anesthesia is a kind of asphyxia and that it decreases respiration. PMID- 19871738 TI - COMPARATIVE STUDIES ON RESPIRATION : V. THE EFFECT OF ETHER ON THE PRODUCTION OF CARBON DIOXIDE BY ANIMALS. AB - 1. The experiments on frog tadpoles show that with 0.15, 0.37, and 0.55 per cent ether solutions there is a decrease in CO(2) output. The effect is reversible. With these concentrations the breathing movements and body movements remained normal during the experiment. In 3.65 and 7.3 per cent ether there is a decrease of respiration followed by an increase which in turn is followed by a decrease. The increase may reach about three times the normal rate. The increase in the CO(2) output is accompanied by the peeling of the skin. The effect is irreversible. 2. Experiments on an aquatic insect, Dineutes assimilis Aube, show that in 7.3 per cent ether there is a decrease followed by an increase which in turn is followed by a decrease. There is no apparent disintegration of structures in the organism accompanying the increase. The effect is irreversible. 3. The experiments on frog eggs with 7.3 per cent ether show a result similar to that found in aquatic insects. 4. Experiments on Fundulus embryos show that with 0.73 per cent ether there is a reversible decrease in the rate of CO(2) production. In 3.65 per cent ether there is a temporary decrease followed by an increase, after which the rate begins to fall off. In 7.3 per cent ether there is an immediate increase amounting to 307 per cent which is followed by a decrease. The increase in the 3.65 and 7.3 per cent ether is accompanied by irreversible changes leading to death. The decrease found in 0.73 per cent ether is not sufficient to cause narcosis, as is shown by experiments on which the same decrease is produced by lowering the temperature. 5. These experiments show that narcosis is not due to asphyxia. The action of anesthetics is due to some other cause than the effect on respiration. There is a difference between the animals studied and the plants described in this series of articles, since in animals the increase in the CO(2) output is accompanied by irreversible changes leading to death, while this is not necessarily the case in plants. The reversible (narcotic) action of ether on the animals studied was accompanied by a decrease in the carbon dioxide output; in plants this is not ordinarily the case. These facts are of considerable interest, but their interpretation must be left to future investigation. PMID- 19871739 TI - ON THE CONTROL OF ROPE IN BREAD. PMID- 19871740 TI - THE RATE OF TRANSMISSION IN THE NERVE NET OF THE COELENTERATES. AB - Nerve net transmission in Metridium at 21 degrees C. varies from 121 to 146 mm. per second. PMID- 19871742 TI - TEMPERATURE COEFFICIENT OF THE ACTION OF beta-RAYS UPON THE EGG OF NEREIS. AB - The temperature coefficient of the action of beta-rays from radium upon the egg of Nereis lies between 1.1 and 1.2. This is of a magnitude characteristic of photochemical reactions. PMID- 19871741 TI - AMPHOTERIC COLLOIDS : II. VOLUMETRIC ANALYSIS OF ION-PROTEIN COMPOUNDS; THE SIGNIFICANCE OF THE ISOELECTRIC POINT FOR THE PURIFICATION OF AMPHOTERIC COLLOIDS. AB - 1. It is shown by volumetric analysis that on the alkaline side from its isoelectric point gelatin combines with cations only, but not with anions; that on the more acid side from its isoelectric point it combines only with anions but not with cations; and that at the isoelectric point, pH = 4.7, it combines with neither anion nor cation. This confirms our statement made in a previous paper that gelatin can exist only as an anion on the alkaline side from its isoelectric point and only as a cation on the more acid side of its isoelectric point, and practically as neither anion nor cation at the isoelectric point. 2. Since at the isoelectric point gelatin (and probably amphoteric colloids generally) must give off any ion with which it was combined, the simplest method of obtaining amphoteric colloids approximately free from ionogenic impurities would seem to consist in bringing them to the hydrogen ion concentration characteristic of their isoelectric point (i.e., at which they migrate neither to the cathode nor anode of an electric field). 3. It is shown by volumetric analysis that when gelatin is in combination with a monovalent ion (Ag, Br, CNS), the curve representing the amount of ion-gelatin formed is approximately parallel to the curve for swelling, osmotic pressure, and viscosity. This fact proves that the influence of ions upon these properties is determined by the chemical or stoichiometrical and not by the "colloidal" condition of gelatin. 4. The sharp drop of these curves at the isoelectric point finds its explanation in an equal drop of the water solubility of pure gelatin, which is proved by the formation of a precipitate. It is not yet possible to state whether this drop of the solubility is merely due to lack of ionization of the gelatin or also to the formation of an insoluble tautomeric or polymeric compound of gelatin at the isoelectric point. 5. On account of this sudden drop slight changes in the hydrogen ion concentration have a considerably greater chemical and physical effect in the region of the isoelectric point than at some distance from this point. This fact may be of biological significance since a number of amphoteric colloids in the body seem to have their isoelectric point inside the range of the normal variation of the hydrogen ion concentration of blood, lymph, or cell sap. 6. Our experiments show that while a slight change in the hydrogen ion concentration increases the water solubility of gelatin near the isoelectric point, no increase in the solubility can be produced by treating gelatin at the isoelectric point with any other kind of monovalent or polyvalent ion; a fact apparently not in harmony with the adsorption theory of colloids, but in harmony with a chemical conception of proteins. PMID- 19871743 TI - ON THE EXPERIMENTAL PRODUCTION OF EDEMA IN LARVAL AND ADULT ANURA. PMID- 19871744 TI - STUDIES ON BIOLUMINESCENCE : IX. CHEMICAL NATURE OF CYPRIDINA LUCIFERIN AND CYPRIDINA LUCIFERASE. AB - There seems to be very little doubt but that luciferase is a protein or so closely associated with proteins that their removal destroys its characteristic properties. The particular group of proteins to which it belongs may be arrived at by a process of exclusion, and only the group of albumins has properties which agree completely with those of luciferase. Dubois believes Pholas luciferase to be an oxidizing enzyme similar to the oxydones of Battelli and Stern because it is readily destroyed by fat solvents such as chloroform, strong alcohol, etc. He has detected iron in a luciferase solution which has dialyzed against running water for a long time, and believes it to be made up of protein in combination with iron and to act as an "oxyzymase ferrique." Cypridina luciferase, on the other hand, is not readily destroyed by fat solvents. Toluene and chloroform are good preservatives, and I often make use of them for this purpose, keeping the luciferase solutions for many months. Professor A. H. Phillips of Princeton University has very kindly analyzed some whole dried Cypridinoe for me and finds iron, copper, and manganese but no zinc or vanadium to be present. Whether these metals are connected with the action of Cypridina luciferase is uncertain, but it is significant that all three of the metals thought to be concerned in organic oxidations are present. Although a large amount of luciferin mixed with a small amount of luciferase will use up all the latter, I agree with Dubois that luciferase has sufficient properties in common with the enzymes as a class to be considered an enzyme. The peroxidases are well known to be used up in the reactions they accelerate. All workers on enzymes agree that the more enzymes are purified the less active they become. The chemical procedures necessary to remove foreign material bring about irreversible changes in the enzyme itself, a characteristic also of many protein groups and of the colloidal state in general. This is true in the case of luciferase, for the crude luciferase solution is the most active preparation that can be obtained. I believe that Cypridina luciferase should be placed in a class of oxidizing enzymes by itself-a group having the chemical reactions of an albumin, possibly in combination with some heavy metal, and which as far as we know, acts specifically on only one substance, Cypridina luciferin. It resembles the plant peroxidases in resisting the action of chloroform, toluene, etc., but will not oxidize any of the hydroxyphenol or aminophenol compounds so readily oxidized by the peroxidases, nor will the peroxidases oxidize luciferin with light production. Dubois' researches show that Pholas luciferase differs in some properties from Cypridina luciferase, and my own work indicates that firefly luciferase is more like that of Pholas. A comparative study of other species of luminous animals is needed in order to delimit more accurately the class of luciferases as a whole. Luciferin presents many characteristics in common with the proteins, but two, which, to say the least, throw doubt on its protein nature: (1) its peculiar solubility (in alcohols, esters, and glacial acetic acid), (2) and its resistance to digestion by proteases, even by trypsin which has almost universal digestive action. These two peculiarities have been discussed above. We can only say that if a protein, luciferin must belong to a new group differing from known natural proteins in these respects. In general characteristics this new group would fall somewhere on the border-line between the proteoses and peptones. It would not be surprising to find in nature proteoses or peptones soluble in absolute alcohol. We know also that some NH-CO linkages of proteins are broken down with great difficulty by trypsin as it is difficult to obtain a tryptic digest of protein which does not give the biuret reaction, and the work of Fischer and Abderhalden has shown that certain artificial polypeptides are not digested by pure activated pancreatic juice. We have, then, three possibilities. Luciferin is (1) either a natural proteose not attacked by trypsin, or (2) if attacked by trypsin, its decomposition products (presumably amino-acids) still contain the group oxidizable with light production, or (3) it is not a protein at all. I believe that luciferin has too many protein characteristics to conform to the last possibility. I have been unable to oxidize with light production various mixtures of amino-acids (from beef and casein) by means of luciferase and consequently am led to believe that luciferin is a new natural proteose, soluble in absolute alcohol and not digested by trypsin. Dubois believes Pholas luciferin to be a natural albumin with acid properties. Cypridina luciferin could not possibly be regarded as an albumin, but it is very likely that the luciferins of different species of luminous animals differ in certain characteristics. As in the case of the luciferases, we know that the luciferins are not identical substances, and only future work can determine in what particulars they differ. A summary of the properties of Cypridina luciferin and Cypridina luciferase will be found in the tables accompanying this paper. PMID- 19871745 TI - THE TEMPERATURE COEFFICIENT OF PHOTOSYNTHESIS. AB - The temperature coefficient of photosynthesis in Ulva (between 17 degrees and 27 degrees C.) is 1.81. This may be explained by assuming that the process involves a light reaction with a low coefficient followed by an ordinary reaction with a high coefficient. PMID- 19871746 TI - A COMPARATIVE STUDY OF PERMEABILITY IN PLANTS. AB - Quantitative studies on Laminaria (a brown alga), Ulva (a green alga), Rhodymenia (a red alga), and Zostera (a flowering plant) show that the behavior of these plants, in respect to changes in permeability, is essentially alike in all cases. PMID- 19871747 TI - NATURE OF THE RETARDING INFLUENCE OF THE THYMUS UPON AMPHIBIAN METAMORPHOSIS. AB - 1. Though thymus-fed salamander larvae often metamorphose normally, thymus feeding sometimes retards and in rare cases inhibits metamorphosis completely. 2. The addition of normal food to a thymus diet abolishes the inhibitory effect of the thymus. 3. Addition of a small quantity of iodothyrin leads rapidly to precocious metamorphosis of thymus-fed larvae. 4. The inhibitory effect of the thymus is not due to a specific inhibiting substance in the thymus, but to the absence from the thymus of a substance required to develop the thyroid to the secretory state. PMID- 19871748 TI - PARATHYROIDS AND CALCIUM METABOLISM. AB - The experiments reported in this article are in full agreement with the facts known about the action of Ca and Mg salts in tetanic animals. In the concentrations used here both Ca lactate and Mg lactate suppressed the muscular convulsions in the tetanic salamander larvae. The Mg lactate, however, appears to be more effective than the Ca lactate. At any rate the suppression of the tetanic convulsions does not seem to be a specific action of the calcium. The most important result seems to be the fact that the salts used, though they prevented the muscular convulsions, did not prevent the other symptoms of tetany which in the salamander larvae are very definite and constant. The permanent spasmodic contractions and the paralysis of the muscles developed in spite of the presence of the Ca and Mg, Furthermore, the muscular contractions and the paralysis developed even in such thymus-fed animals in which the convulsions had been suppressed completely; this was the case in one of the animals of the Mg series. From the experiments of Biedl and others it is likely that the tetanic convulsions are due to lesions of the central nervous system, since convulsions of a leg can be prevented by isolating it from the central nervous system by cutting the nerves which connect the muscles with the central nervous system. Evidently these lesions of the central nervous system are the chief factor in tetany, while the convulsions of the muscles are only an effect. In the larvae of salamanders these lesions find a definite expression in the permanent paralysis of almost the entire muscular system. In the writer's opinion, MacCallum's hypothesis that the tetany toxin has a special affinity for Ca, thereby diminishing the Ca content of the organism, cannot be disproved at present. But the present experiments seem to prove, first, that the tetany-producing substance causes permanent lesions of the nervous system, which lead to permanent spasmodic contractions and paralysis of the muscle even in the absence of tetanic convulsions, and second, that these cannot be prevented by either Ca or Mg. For the most part they result in an early death of the animals no matter whether or not Ca or Mg has been applied. In connection with this fact we wish to mention Biedl's claim that no one has yet succeeded in prolonging the life of parathyroidectomized animals by the application of Ca. From MacCallum's paper, on account of the lack of controls, it cannot be seen whether his parathyroidectomized dogs lived longer with Ca treatment than without. That in spontaneous tetany Ca treatment may effect a cure, as is evident from the report by Howland and Marriott, does not prove that in this case Ca has inhibited tetany as a disease. In spontaneous tetany the period of the action of the tetany producing substance may be a very short one and the mere prevention of the tetanic convulsions may keep the patient alive until normal function of the glands involved has been restored. The pathological changes which the central nervous system undergoes in this short period may not be severe enough to endanger the life of the patient after the cessation of the action of the tetany toxin. In the light of the facts presented our experiments lead to the following conclusions: 1. The thymus gland excretes a tetany-producing substance which in the normal animal is antagonized in an unknown way by the parathyroids. 2. In animals devoid of parathyroids (salamander larvae, parathyroidectomized mammals) this substance may, according to MacCallum, reduce the Ca content of the organism; but by far the most dangerous and important quality of this substance is its highly injurious effect upon the central nervous system, which causes permanent spasmodic contractions of the muscles and paralysis of almost the entire muscular system. 3. It is possible to prevent the muscular contractions by introducing Ca salts into the body, though this can be done more effectively by means of Mg salts. 4. No substance, however, has been found so far to antagonize the tetany toxin and to prevent the development of the lesions of the central nervous system caused by the tetany toxin. 5. This explains why in spite of the application of Ca or Mg and in spite of the suppression by these substances of the tetanic convulsions the other symptoms of tetany develop and frequently lead to the death of the animal. 6. Accordingly the most important function of the parathyroids is to prevent the tetany toxin, by antagonizing it, from coming into contact with the central nervous system. PMID- 19871749 TI - RATE OF RECOVERY FROM THE ACTION OF FLUORITE RAYS. PMID- 19871750 TI - SENSITIZATION TO HEAT DUE TO EXPOSURE TO LIGHT OF SHORT WAVE-LENGTHS. PMID- 19871751 TI - THE PHYSIOLOGICAL BASIS OF MORPHOLOGICAL POLARITY IN REGENERATION. I. AB - 1. In Bryophyllum calycinum two apical leaves suppress the shoot formation in all the dormant buds situated basally from the leaf; one apical leaf suppresses the shoot formation in the basal buds situated in the same half of the stem where the leaf is, and, if one-half of the petiole of such a leaf is removed, the growth of basal buds in one quadrant of the stem is suppressed. 2. This inhibitory influence of a leaf upon shoot formation in the basal part of a stem is diminished or disappears when the mass of the leaf is reduced below a certain limit. 3. The inhibitory influence of an apical leaf upon the growth of shoots in horizontally suspended stems is greater when the leaf is on the upper than when it is on the lower side of the stem. 4. All these facts suggest the possibility that the inhibitory influence of the leaf upon shoot formation is due to inhibitory substances secreted by the leaf and carried by the sap from the leaf towards the base of the stem. 5. An apical leaf accelerates root formation in the basal part of a stem and this accelerating effect increases with the mass of the leaf. 6. This inhibitory influence of a leaf upon shoot formation and the favoring influence upon root formation in the more basally situated parts of the stem is one of the factors determining the polar character of regeneration. PMID- 19871752 TI - AMPHOTERIC COLLOIDS : III. CHEMICAL BASIS OF THE INFLUENCE OF ACID UPON THE PHYSICAL PROPERTIES OF GELATIN. AB - 1. The method of removing the excess of hydrobromic acid after it has had a chance to react chemically with gelatin has permitted us to measure the amount of Br in combination with the gelatin. It is shown that the curves representing the amount of bromine bound by the gelatin are approximately parallel with the curves for the osmotic pressure, the viscosity, and swelling of the gelatin solution. This proves that the curves for osmotic pressure are an unequivocal function of the number of gelatin bromide molecules formed under the influence of the acid. The cc. of 0.01 N Br in combination with 0.25 gm, of gelatin we call the bromine number. 2. The explanation of this influence of the acid on the physical properties of gelatin is based on the fact that gelatin is an amphoteric electrolyte, which at its isoelectric point is but sparingly soluble in water, while its transformation into a salt with a univalent anion like gelatin Br makes it soluble. The curve for the bromine number thus becomes at the same time the numerical expression for the number of gelatin molecules rendered soluble, and hence the curve for osmotic pressure must of necessity be parallel to the curve for the bromine number. 3. Volumetric analysis shows that gelatin treated previously with HBr is free from Br at the isoelectric point as well as on the more alkaline side from the isoelectric point (pH >== 4.7) of gelatin. This is in harmony with the fact that gelatin (like any other amphoteric electrolyte) can dissociate on the alkaline side of its isoelectric point only as an anion. On the more acid side from the isoelectric point gelatin is found to be in combination with Br and the Br number rises with the pH. 4. When we titrate gelatin, treated previously with HBr but possessing a pH = 4,7, with NaOH we find that 25 cc. of a 1 per cent solution of isoelectric gelatin require about 5.25 to 5.5 cc. of 0.01 N NaOH for neutralization (with phenolphthalein as an indicator). This value which was found invariably is therefore a constant which we designate as "NaOH (isoelectric)." When we titrate 0.25 gm. of gelatin previously treated with HBr but possessing a pH < 4.7 more than 5.5 cc. of 0.01 N NaOH are required for neutralization. We will designate this value of NaOH as "(NaOH)(n)," where n represents the value of pH. If we designate the bromine number for the same pH as "Br(n)" then we can show that the following equation is generally true: (NaOH)(n) = NaOH (isoelectric) + Br(n). In other words, titration with NaOH of gelatin (previously treated with HBr) and being on the acid side of its isoelectric point results in the neutralization of the pure gelatin (NaOH isoelectric) with NaOH and besides in the neutralization of the HBr in combination with the gelatin. This HBr is set free as soon as through the addition of the NaOH the pH of the gelatin solution becomes equal to 4.7. 5. A comparison between the pH values and the bromine numbers found shows that over 90 per cent of the bromine or HBr found was in our experiments in combination with the gelatin. PMID- 19871753 TI - INFLUENCE OF ELECTROLYTES UPON THE VISCOSITY OF DOUGH. PMID- 19871755 TI - DECREASE OF PERMEABILITY AND ANTAGONISTIC EFFECTS CAUSED BY BILE SALTS. AB - Sodium taurocholate is able to produce a decrease in permeability and to antagonize NaCl. This confirms the hypothesis that antagonistic relations can be predicted from studies on the permeability of pure substances. PMID- 19871754 TI - COMPARATIVE STUDIES ON RESPIRATION : VI. INCREASED PRODUCTION OF CARBON DIOXIDE ACCOMPANIED BY DECREASE OF ACIDITY. AB - In petals of Salvia high concentrations of ether cause an increase in oxygen consumption and in the production of CO(2), while at the same time a decrease occurs in the acidity of the cell contents. PMID- 19871756 TI - A COMPARISON OF PERMEABILITY IN PLANT AND ANIMAL CELLS. AB - Quantitative studies show a striking agreement between frog skin and plant tissues in respect to certain important aspects of permeability, antagonism, injury, recovery, and death. PMID- 19871757 TI - THE RELATION BETWEEN THE OXYGEN CONCENTRATION AND RATE OF REDUCTION OF METHYLENE BLUE BY MILK. AB - The rate of reduction of methylene blue by milk and acetaldehyde is proportional to the concentration of oxygen in the milk. This fact may be made the basis of a method of determining oxygen in gaseous mixtures. PMID- 19871758 TI - INFLUENCE OF TEMPERATURE AND HYDROGEN ION CONCENTRATION UPON THE SPORE CYCLE OF BACILLUS SUBTILIS. AB - 1. At 5 degrees C. no germination took place. 2. At 25 degrees C. and at 37 degrees C. germination occurs if the hydrogen ion concentration of the broth is kept between pH 5 and pH 10, but not at higher or lower pH values. 3. The completion of the spore cycle likewise requires a hydrogen ion concentration between pH 5 and pH 10. 4. The spores can germinate when the pH value is 10, although after germination the vegetative cells multiply only to a very slight extent and soon pass into spores. 5. The slight growth and multiplication of vegetative cells in broth of pH 10 suggest that the formation of endospores in this medium must be caused largely by the unfavorable reaction of the medium rather than by the accumulation of metabolic products. 6. Automatic adjustment of the medium seems to play a role in the completion of the spore cycle. 7. The results are not only of theoretical importance but they have a practical application to the preservation of food by canning and by other methods. PMID- 19871759 TI - BIOELEMENTS; THE CHEMICAL ELEMENTS OF LIVING MATTER. PMID- 19871760 TI - PHOTOREACTIONS OF PARTIALLY BLINDED WHIP-TAIL SCORPIONS. AB - The experiments dealt with in this paper were devised to ascertain (1) the relative effectiveness as photoreceptors of the whip-tail scorpion's median eyes, lateral eye groups, and cutaneous sensitive areas, and (2) the effect on orientation produced by symmetrical and by asymmetrical interference with the photoreceptive mechanism. Each of the receptors was eliminated unilaterally and bilaterally, singly and in combinations with other receptors. In all, sixteen different abnormal conditions of the photoreceptive apparatus were produced. The reactions of animals thus partially blinded were measured in terms of angular deflection from an initial path of locomotion. Measurements obtained under anterior, lateral, and bilaterally balanced illumination were compared with measurements made on normal animals under the same conditions of illumination. The change from the normal reaction induced by covering a photoreceptor was taken as an index of the effectiveness of the receptor prevented from functioning. By comparing the values of the changes from normal reactions produced by the elimination of the several receptors, their relative effectiveness is approximated as median eyes : lateral eyes : cutaneous sensitive areas :: 1:1.6:2.2. All animals in which the receptive mechanism was rendered functionally asymmetrical exhibited, when subJected to bilaterally balanced illumination, deflections toward the side which had been made less sensitive. In a series of measurements made on animals in ten different conditions of asymmetry the amplitudes of the deflections were proportional to the degree of unbalance which had been produced in the photosensitive mechanism. Animals in which the receptive mechanism was reduced but left in a symmetrical condition maintained an undisturbed balance of reaction when subjected to equal, opposed lights. Under lateral or anterior illumination the rate of attaining a new direction of orientation was reduced in proportion to the extent of the interference with the receptive mechanism. The reactions of symmetrically and asymmetrically blinded scorpions indicate that orientation is attained and maintained by a transmission of impulses to the muscles of locomotion which is proportional bilaterally to the excitation of the symmetrically located photoreceptors. In their effect on orientation the three pairs of receptors are completely coordinated. Orientation depends upon bringing the excitation of the receptive mechanism as a whole into bilateral equilibrium. PMID- 19871761 TI - A STUDY OF THE ACTION OF ACID AND ALKALI ON GLUTEN. AB - In this paper there are reported studies of the acid-base equilibrium in systems containing gluten suspended in solution of hydrochloric acid and sodium hydroxide. The studies have involved measurements of the hydrogen ion concentration, of the electrical conductivity, and of the solution of the proteins. Further, measurements have been made of the swelling and of the viscosity of the gluten component of such systems. The results seem to show that simple chemical phenomena are most important in such systems, and that the modifications of these, resulting from colloidal and heterogeneous characteristics, are of secondary importance in determining the condition of equilibrium, though somewhat more significant in the progress of the system toward the condition of equilibrium. PMID- 19871762 TI - RELATION BETWEEN THYROID GLAND, METAMORPHOSIS, AND GROWTH. AB - 1. Two substances are involved in amphibian metamorphosis as studied in Ambystoma opacum: first, iodine, which is taken up by the food, and second, an excretor substance, which is evolved during the processes of growth and serves to induce the excretory function of the thyroid gland. 2. This explains why in larvae, whose metamorphosis is inhibited by lack of iodine, growth is checked at the time when metamorphosis should occur; for at this time the excretor substance commences to act and this results, if iodine is absent, in the excretion by the thyroid of toxic substances which cause the breakdown of proteins and consequently a decrease in size of the larvae. 3. Larvae whose metamorphosis is inhibited by extirpation of the thyroid or by the hereditary lack of a thyroid (as is the case in Typhlomolge) can grow normally, since in them the action of the excretor substance cannot result in the excretion by the thyroid of a toxic growth-inhibiting substance. 4. At low temperature less excretor substance is produced than at high temperature during an equal rate of growth; therefore larvae kept at low temperature reach a larger size than larvae kept at high temperature, before they metamorphose. PMID- 19871763 TI - AMPHOTERIC COLLOIDS : IV. THE INFLUENCE OF THE VALENCY OF CATIONS UPON THE PHYSICAL PROPERTIES OF GELATIN. AB - 1. A method is given by which the amount of equivalents of metal in combination with 1 gm. of a 1 per cent gelatin solution previously treated with an alkali can be ascertained when the excess of alkali is washed away and the pH is determined. The curves of metal equivalent in combination with 1 gm. of gelatin previously treated with different concentrations of LiOH, NaOH, KOH, NH(4)OH, Ca(OH)(2), and Ba(OH)(2) were ascertained and plotted as ordinates, with the pH of the solution as abscissae, and were found to be identical. This proves that twice as many univalent as bivalent cations combine with the same mass of gelatin, as was to be expected. 2. The osmotic pressure of 1 per cent solutions of metal gelatinates with univalent and bivalent cation was measured. The curves for the osmotic pressure of 1 per cent solution of gelatin salts of Li, Na, K, and NH(4) were found to be identical when plotted for pH as abscissae, tending towards the same maximum of a pressure of about 325 mm. of the gelatin solution (for pH about 7.9). The corresponding curves for Ca and Ba gelatinate were also found to be identical but different from the preceding ones, tending towards a maximum pressure of about 125 mm. for pH about 7.0 or above. The ratio of maxi mal osmotic pressure for the two groups of gelatin salts is therefore about as 1:3 after the necessary corrections have been made. 3. When the conductivities of these solutions are plotted as ordinates against the pH as abscissae, the curves for the conductivities of Li, Na, Ca, and Ba gelatinate are almost identical (for the same pH), while the curves for the conductivities of K and NH(4) gelatinate are only little higher. 4. The curves for the viscosity and swelling of Ba (or Ca) and Na gelatinate are approximately parallel to those for osmotic pressure. 5. The practical identity or close proximity of the conductivities of metal gelatinates with univalent and bivalent metal excludes the possibility that the differences observed in the osmotic pressure, viscosity, and swelling between metal gelatinates with univalent and bivalent metal are determined by differences in the degree of ionization (and a possible hydratation of the protein ions). 6. Another, as yet tentative, explanation is suggested. PMID- 19871764 TI - THE SELECTIVE ACTION OF NICOTINE ON THE CENTRAL NERVOUS SYSTEM OF THE SQUID, LOLIGO PEALII. AB - 1. In specimens of freshly hatched squid, Loligo pealii, nicotine acts upon the cerebral ganglia alone. 2. After 1 minute in the nicotine solution 1:500,000, the latent period for the mantle spasm is independent of the time spent in the solution. 3. The mantle spasm is conditioned by a chemical reaction, since the temperature coefficient of the process has a magnitude of about 2.8. 4. The velocity of the process which brings about the mantle spasm varies as the cube root of the concentration of the nicotine. PMID- 19871765 TI - ON THE EXPERIMENTAL PRODUCTION OF EDEMA BY NEPHRECTOMY. PMID- 19871766 TI - ANTAGONISM BETWEEN ALKALOIDS AND SALTS IN RELATION TO PERMEABILITY. AB - Certain alkaloids which decrease permeability are able to antagonize NaCl. In this respect they resemble salts which decrease permeability, for it has been shown that such salts antagonize NaCl. PMID- 19871767 TI - A NEW APPARATUS FOR MEASURING SURFACE TENSION. PMID- 19871768 TI - RELATION BETWEEN METAMORPHOSIS AND OTHER DEVELOPMENTAL PHENOMENA IN AMPHIBIANS. AB - 1. The difference in time existing between the first shedding of the skin and the reduction of the gills to mere stubs without fringes is constant and unchangeable, which indicates that the fundamental cause for both is a common one. 2. This common cause is the action of iodine, and consequently both phenomena constitute, or at least are part of, the metamorphosis of the salamanders. 3. The development of the adult skin coloration and of the legs may take place either before or after metamorphosis. Iodine cannot enforce either of these phenomena. 4. The same is true of the development of the sex organs. 5. Development of the tongue and palatal teeth can be checked even in animals in which metamorphosis takes place. 6. Consequently development of the skin coloration, as well as development of the legs, sex organs, tongue, and palatal teeth are all caused by substances not identical with the substances causing metamorphosis and, since they are also all independent of each other in their development, it is probable that special chemical mechanisms exist for the development of each one of these six groups of organs. 7. This assumption is also supported by the fact that the order of development in several of these organ pairs can be changed by a difference in temperature, which would indicate that the development of each of these groups of organs is caused by chemical reactions with different temperature coefficients. 8. That the germ cells can develop in amphibians either before or after metamorphosis does not mean that the germ plasma is opposed as a unit to the somatic plasma, since other organs which are believed to be part of the somatic plasma behave in this respect like the germ cells. 9. The noteworthy feature of the amphibian metamorphosis is that instead of being controlled and kept in harmony by the organic individual the development of at least six groups of organs is controlled separately by the action of probably six different chemical mechanisms, each of which can be stopped or enforced independently either by directly supplying the substances required or by causing an increased formation within the body by suitable temperatures. PMID- 19871769 TI - SENSORY EQUILIBRIUM AND DARK ADAPTATION IN MYA ARENARIA. AB - 1. The reaction time of Mya to light is composed of two parts. The first, a sensitization period, is an exceedingly short interval of the order of magnitude associated with photographic processes. The second is a latent period of about 1.3 seconds, during which Mya need not remain exposed to the stimulating light. 2. The process of dark adaptation in Mya is orderly. Its progress may be represented by the formation of a photosensitive substance according to the dynamics of a bimolecular reaction. See PDF for Structure 3. Photosensory equilibrium as represented by the light- and dark-adapted conditions finds a rational explanation in terms of the "stationary state" of a reversible photochemical reaction involving a photosensitive substance and its two precursors. 4. There are two corollaries to this hypothesis. The first requires that the reaction time at sensory equilibrium for a given intensity should vary inversely with the temperature; the second, that the rate of dark adaptation should vary directly with the temperature. Experiments verified both of these requirements. PMID- 19871770 TI - AMPHOTERIC COLLOIDS : V. THE INFLUENCE OF THE VALENCY OF ANIONS UPON THE PHYSICAL PROPERTIES OF GELATIN. AB - 1. When we plot the values of osmotic pressure, swelling, and viscosity of gelatin solutions as ordinates over the pH as abscissae, practically identical curves are obtained for the effect of monobasic acids (HCl, HBr, HNO(3), and acetic acid) on these properties. 2. The curves obtained for the effect of H(2)SO(4) on gelatin are much lower than those obtained for the effect of monobasic acids, the ratio of maximal osmotic pressures of a 1 per cent solution of gelatin sulfate and gelatin bromide being about 3:8. The same ratio had been found for the ratio of maximal osmotic pressures of calcium and sodium gelatinate. 3. The curves representing the influence of other dibasic and tribasic acids, viz. oxalic, tartaric, succinic, citric, and phosphoric, upon gelatin are almost identical with those representing the effect of monobasic acids. 4. The facts mentioned under (2) and (3) permit us to decide between a purely chemical and a colloidal explanation of the influence of acids on the physical properties of gelatin. In the former case we should be able to prove, first, that twice as many molecules of HBr as of H(2)SO(4) combine with a given mass of gelatin; and, second, that the same number of molecules of phosphoric, citric, oxalic, tartaric, and succinic acids as of HNO(3) or HCl combine with the same mass of gelatin. It is shown in the present paper that this is actually the case. 5. It is shown that gelatin sulfate and gelatin bromide solutions of the same pH have practically the same conductivity. This disproves the assumption of colloid chemists that the difference in the effect of bromides and sulfates on the physical properties of gelatin is due to a different ionizing and hydratating effect of the two acids upon the protein molecule. PMID- 19871771 TI - INTRACELLULAR ACIDITY IN VALONIA. PMID- 19871772 TI - ON THE CONTROL OF THE RESPONSE TO SHADING IN THE BRANCHIAE OF CHROMODORIS. AB - The branchial plumes of Chromodoris respond, by contraction, to a decrease in light intensity. This response is obliterated by high temperatures (above 32 degrees ) and by direct sunlight, and is possible only within a limited range of alkalinity of the sea water. A concealing retraction of the whole gill-crown is reflexly determined by the self-contraction of the individual plumes under "optimal" conditions of light, temperature, and alkalinity. This protective response of the branchiae is superimposed upon their simple system of fundamental activities (protrusion, retraction) apparently concerned with regulating the respiratory exchange of the nudibranch. PMID- 19871773 TI - IODINE AND THE THYROID : III. THE SPECIFIC ACTION OF IODINE IN ACCELERATING AMPHIBIAN METAMORPHOSIS. AB - 1. Amphibian metamorphosis depends upon the amount of iodine secured by the larvae; the greater the quantity the more rapid the differentiation. 2. Bromine is physiologically inert when fed even in large quantities to frog larvae, hence it cannot be substituted for iodine. Bromine feeding has no effect on the thyroid. 3. Iodine is the active constituent of the thyroid gland, in the Anura at any rate, and functions within the body by stimulating intracellular oxidations; it is apparently specific in its action. 4. The basal metabolism of patients suffering from athyreosis, whose metabolism is 40 per cent below normal, is very likely held at this figure and prevented from sinking lower to the death point by the introduction of iodine into the body through food and water. 5. The thyroid gland is an organ the function of which is the extraction from the circulation, storage, and supplying to the organism, under the pressure of its needs, the small quantities of iodine taken into the body. The chief function of this gland then is the utilization of iodine in small quantities. PMID- 19871774 TI - THE EFFECT OF VARIOUS ACIDS ON THE DIGESTION OF PROTEINS BY PEPSIN. AB - 1. At equal hydrogen ion concentration the rate of pepsin digestion of gelatin, egg albumin, blood albumin, casein, and edestin is the same in solutions of hydrochloric, nitric, sulfuric, oxalic, citric, and phosphoric acids. Acetic acid diminishes the rate of digestion of all the proteins except gelatin. 2. There is no evidence of antagonistic salt action in the effect of acids on the pepsin digestion of proteins. 3. The state of aggregation of the protein, i.e. whether in solution or not, and the viscosity of the solution have no marked influence on the rate of digestion of the protein. PMID- 19871776 TI - THE GROWTH OF HIGHER PLANTS IN SOILS FREE OF MICROORGANISMS. PMID- 19871775 TI - THE RESPIRATORY RATE OF THE SCIATIC NERVE OF THE FROG IN REST AND ACTIVITY. AB - 1. With the indicator method of Haas, the rates of carbon dioxide production have been measured in the case of the sciatic nerve, various parts of the brain, and the sartorius muscle of the frog. The rate of respiration of the sciatic nerve is from 10 to 30 per cent of that of the other tissues, varying somewhat with the individual. 2. Stimulation of the sciatic nerve with induction shocks sufficient to induce tetanus of the muscle does not increase the output of carbon dioxide from the sciatic nerve, even if continued as long as 30 minutes. Sartorius muscle used as a control showed a marked increase in carbon dioxide production upon relaxation after contraction resulting from such stimulation. 3. These facts indicate that the nerve impulse does not depend upon processes leading to the production of carbon dioxide. PMID- 19871778 TI - THE INHERITANCE OF A FLUCTUATING CHARACTER. PMID- 19871777 TI - THE ETCHING OF MARBLE BY ROOTS IN THE PRESENCE AND ABSENCE OF BACTERIA. AB - In a study of the effect of soil bacteria upon the etching power of the roots of Canada field peas upon polished marble, it has been shown that the presence of the bacteria increases the etching power of the roots. PMID- 19871779 TI - VERMILION-DEFICIENCY. AB - In May, 1916, a culture of Drosophila melanogaster showed that a new sex-linked lethal had arisen. The linkage relations indicated that the position of the lethal was in the neighborhood of the sex-linked recessive "vermilion," whose locus in the X chromosome is at 33.0. When females heterozygous for the lethal were outcrossed to vermilion males, all the daughters that received the lethal bearing chromosome showed vermilion eye-color, though, from the pedigree, vermilion was known to be absent from the ancestry of the mother. The lethal action and the unexpected appearance of vermilion both suggested that this was another instance of the phenomenon called "deficiency;" that is, the loss or "inactivation" of the genes of a section of the X chromosome. The lethal action would then be due to the deficient region including one or more genes necessary for the life of the individual. The appearance of vermilion in females carrying only one vermilion gene would be explainable on the ground that the deficient bearing females are virtually haploid for the region including the vermilion locus. Linkage tests showed that the amount of crossing over in the neighborhood of the deficiency was cut down by about five units. Part of this may be attributed to the actual length of the "deficient" region, within which it is probable that no crossing over occurs, and part (probably most) to an alteration in the synaptic relations in the regions immediately adjacent. In more remote regions there was no disturbance or perhaps a slight rise in the frequency of crossing over. Both the local fall and the possible rise in more distant regions would seem to argue that a "pucker" at synapsis had been caused by an actual shortening of the deficient chromosome. That the deficient region extends to the left of the locus of vermilion was indicated by a test in which it was observed that the presence of an extra piece of chromosome including the loci for vermilion and sable ("vermilion-sable duplication") did not neutralize the lethal action of the deficiency. Haploid tests with the other recessive mutations in the neighborhood of vermilion showed that the deficiency was not extensive enough to include their loci. Cytological preparations were made but were unsatisfactory. The stock was finally lost, apparently as the result of injurious action upon viability, fertility, and productivity by the deficiency. PMID- 19871780 TI - THE NATURE OF THE LATENT PERIOD IN THE PHOTIC RESPONSE OF MYA ARENARIA. AB - The latent period in the response of Mya to illumination varies inversely as the duration of the exposure to which it is subjected. The reciprocal of the latent period, measuring the velocity of the process which underlies it, is a linear function of the exposure period. Since the duration of the exposure represents the amount of photochemical activity, it is concluded that the substances formed at that time act to catalyze a chemical reaction which determines the duration of the latent period. This explanation is in accord with the previous work on the photochemical reaction and with the effect of temperature on the latent period. As a result of the combined investigations there is presented a concrete hypothesis for the mechanism of photic reception in Mya. PMID- 19871781 TI - THE EFFECT OF TEMPERATURE ON THE LATENT PERIOD IN THE PHOTIC RESPONSE OF MYA ARENARIA. AB - 1. The effect of temperature on the reaction time of Mya to light is mainly confined to the latent period. The sensitization period, representing a photochemical process, is changed comparatively little. 2. The relation between the latent period and the temperature is adequately expressed by the Arrhenius equation, for temperatures below 21 degrees C. Above this temperature, the latent period becomes increasingly longer than is required by the Arrhenius formula when micro = 19,680. 3. These deviations, occurring above the highest environmental temperature of Mya, are explained on the assumption that the principal product formed during the latent period is inactivated by heat. 4. Calculation of the velocity of the hypothetical inactivation reaction at different temperatures shows that it also follows the Arrhenius rule when micro = 48,500. This value of micro corresponds to those generally found for spontaneous inactivations and destructions. PMID- 19871782 TI - THE PHYSIOLOGICAL BASIS OF MORPHOLOGICAL POLARITY IN REGENERATION. II. AB - 1. The experiments show that the mass of air roots formed in a stem increases with the mass of the leaf attached to the stem, though it has not been possible to establish an exact mathematical relation between the two masses, owing to unavoidable sources of error. 2. Darkened leaves do not increase the mass of roots formed. 3. In stems suspended horizontally air roots appear on the lower side of the stem, with the exception of the cut end where they usually appear around the whole circumference of the stem. When the lower half of a stem suspended horizontally is cut off, roots are formed on the upper side. It is shown by experiments on leaves suspended horizontally that the more rapidly growing roots and shoots on the lower side inhibit the root and shoot formation in the upper half of such a leaf; and likewise the more rapid formation of roots on the lower side of a horizontally suspended stem seems to account for the inhibition of root formation on the upper side of such a stem. Likewise the more rapid growth of shoots on the upper side of a stem suspended horizontally is likely to inhibit the growth of shoots on the lower side. 4. Each leaf contains in its axil a preformed bud capable of giving rise to a root, which never grows out in the normal stem on account of the inhibitory influence of the normal roots at the base of the plant. These dormant root buds are situated above (apically from) the dormant shoot bud. The apical root buds can be caused to develop into air roots when a piece of stem is cut out from a plant from which the leaves except those in the basal node of the piece are removed. The larger these basal leaves the better the experiments succeed. 5. These apical air roots grow out in a few days, while the roots at the basal end of the stem (which in our experiments dip into water) grow out about a week later. As soon as the basal roots grow out in water they cause the air roots in the more apical region of the stem to dry out and to disappear. 6. In addition to the basal roots, basal nodes have also an inhibitory effect on the growth of the dormant root buds in the apical region of a stem. This is indicated by the fact that a stem with one pair of leaves near the base will form apical air roots more readily when no node is situated on the stem basally from the leaf than if there is a node basally from the leaf. PMID- 19871783 TI - THE INFLUENCE OF ELECTROLYTES ON THE ELECTRIFICATION AND THE RATE OF DIFFUSION OF WATER THROUGH COLLODION MEMBRANES. AB - 1. When pure water is separated by a collodion membrane from a watery solution of an electrolyte the rate of diffusion of water is influenced not only by the forces of gas pressure but also by electrical forces. 2. Water is in this case attracted by the solute as if the molecules of water were charged electrically, the sign of the charge of the water particles as well as the strength of the attractive force finding expression in the following two rules, (a) Solutions of neutral salts possessing a univalent or bivalent cation influence the rate of diffusion of water through a collodion membrane, as if the water particles were charged positively and were attracted by the anion and repelled by the cation of the electrolyte; the attractive and repulsive action increasing with the number of charges of the ion and diminishing inversely with a quantity which we will designate arbitrarily as the "radius" of the ion. The same rule applies to solutions of alkalies. (b) Solutions of neutral or acid salts possessing a trivalent or tetravalent cation influence the rate of diffusion of water through a collodion membrane as if the particles of water were charged negatively and were attracted by the cation and repelled by the anion of the electrolyte. Solutions of acids obey the same rule, the high electrostatic effect of the hydrogen ion being probably due to its small "ionic radius." 3. The correctness of the assumption made in these rules concerning the sign of the charge of the water particles is proved by experiments on electrical osmose. 4. A method is given by which the strength of the attractive electric force of electrolytes on the molecules of water can be roughly estimated and the results of these measurements are in agreement with the two rules. 5. The electric attraction of water caused by the electrolyte increases with an increase in the concentration of the electrolyte, but at low concentrations more rapidly than at high concentrations. A tentative explanation for this phenomenon is offered. 6. The rate of diffusion of an electrolyte from a solution to pure solvent through a collodion membrane seems to obey largely the kinetic theory inasmuch as the number of molecules of solute diffusing through the unit of area of the membrane in unit time is (as long as the concentration is not too low) approximately proportional to the concentration of the electrolyte and is the same for the same concentrations of LiCl, NaCl, MgCl(2), and CaCl(2). PMID- 19871784 TI - COMPARATIVE STUDIES ON RESPIRATION : VII. RESPIRATION AND ANTAGONISM. INTRODUCTORY NOTE. PMID- 19871785 TI - COMPARATIVE STUDIES ON RESPIRATION : IX. THE EFFECTS OF ANTAGONISTIC SALTS ON THE RESPIRATION OF ASPERGILLUS NIGER. AB - 1. In the presence of 0.05 per cent dextrose the respiration of Aspergillus niger is increased by NaCl in concentrations of 0.25 to 0.5M, and by 0.5M CaCl(2). 2. Stronger concentrations, as 2M NaCl and 1.25M CaCl(2), decrease the respiration. The decrease in the higher concentrations is probably an osmotic effect of these salts. 3. A mixture of 19 cc. of NaCl and 1 cc. of CaCl(2) (both 0.5M) showed antagonism, in that the respiration was normal, although each salt alone caused an increase. 4. Spores of Aspergillus niger did not germinate on 0.5M NaCl (plus 0.05 per cent dextrose) while they did on 0.5M CaCl(2) (plus 0.05 per cent dextrose) and on various mixtures of the two. This shows that a substance may have different effects on respiration from those which it has upon growth. PMID- 19871786 TI - THE RELATIVE PHYSIOLOGICAL EFFECTS OF beta- AND gamma-RAYS UPON THE EGG OF NEREIS. AB - When Nereis eggs are exposed to radiations from a tube of radium emanation, the walls of which absorb all the alpha-rays, the resulting physiological change is produced by rays having a coefficient of absorption of the order of 23.9 cm.(-1) This fact indicates that the physiological effect is due almost exclusively to beta-rays. The gamma-rays alone can produce the reaction. To produce equivalent physiological effects exposure to gamma-rays alone must be approximately 60 times as long as exposure to beta- and gamma-rays together. PMID- 19871787 TI - THE RELATIVE PHYSIOLOGICAL EFFECTS OF beta-RAYS OF DIFFERENT VELOCITIES. AB - 1. The physiological effect upon the eggs of Nereis of homogeneous groups of beta rays of different velocities is proportional to their ability to ionize air. 2. beta-rays of low velocity produce a greater amount of physiological change than the same number of rays of high velocity. 3. These conclusions are consistent with, but do not prove, the view that the physiological effects of radiations from radium and x-rays are due to the production by them of an ionization of some substance in the egg. PMID- 19871788 TI - CHANGES IN PROTOPLASMIC CONSISTENCY AND THEIR RELATION TO CELL DIVISION. AB - 1. The development of the amphiaster is associated with the formation of two semisolid masses within the more fluid egg substance. 2. The elongation of the egg during cleavage is possibly produced as a consequence of the mutual pressure of these two growing semisolid masses. 3. The division of the egg into two blastomeres consists essentially in a growth, within the egg, of two masses of material at the expense of the surrounding cytoplasm. When all the cytoplasm of the egg is incorporated in these two masses cleavage occurs. 4. After a certain period of time the semisolid masses revert to a more fluid state. In the eggs studied this normally occurs after the cleavage furrow has completed the separation of the two blastomeres. The formation of the furrow, however, may be prevented in various ways, upon which the egg reverts to a single spherical semifluid mass containing two nuclei. 5. An egg mutilated during its semisolid state (amphiaster stage) may or may not revert to a more fluid state. If the more solid state is maintained, the cleavage furrow persists and proceeds till cleavage is completed. If the mutilation causes the egg to revert to the more fluid state the furrow becomes obliterated and a new cleavage plane is subsequently adopted. 6. The nuclei of eggs in the semifluid state are able to alter their positions. In semifluid mutilated eggs the nuclei tend to move to positions which may assure symmetry in aster formation and cleavage. PMID- 19871789 TI - COMPARATIVE STUDIES ON RESPIRATION : VIII. THE RESPIRATION OF BACILLUS SUBTILIS IN RELATION TO ANTAGONISM. AB - 1. In relatively low concentrations of NaCl, KCl, and CaCl(2) the rate of respiration of Bacillus subtilis remains fairly constant for a period of several hours, while in the higher concentrations, there is a gradual decrease in the rate. 2. NaCl and KCl increase the rate of respiration of Bacillus subtilis somewhat at concentrations of 0.15 M and 0.2 M respectively; in sufficiently high concentrations they decrease the rate. CaCl(2) increases the rate of respiration of Bacillus subtilis at a concentration of 0.05 M and decreases the rate at somewhat higher concentrations. 3. The effects of salts upon respiration show a well marked antagonism between NaCl and CaCl(2), and between KCl and CaCl(2). The antagonism between NaCl and KCl is slight and the antagonism curve shows two maxima. PMID- 19871790 TI - A CHANGE IN THE BAR GENE OF DROSOPHILA INVOLVING FURTHER DECREASE IN FACET NUMBER AND INCREASE IN DOMINANCE. PMID- 19871791 TI - ADRENALIN IN ANNELIDS : A CONTRIBUTION TO THE COMPARATIVE STUDY OF THE ORIGIN OF THE SYMPATHETIC AND THE ADRENALIN-SECRETING SYSTEMS AND OF THE VASCULAR MUSCLES WHICH THEY REGULATE. AB - 1. The sympathetic nervous system and the adjuvant adrenalin-secreting system are found in their earliest form in the annelid kingdom, and consist of cells situated in the central nervous system which are the common ancestors of both, and which are both secretory and nervous in function. 2. These cells are developed in the annelid kingdom parallel with the development of a contractile vascular system, which possesses muscles comparable in physiological actions with the muscle of the vertebrate heart. 3. This vascular muscle is regulated by the processes of the common ancestral cells as well as by their secretory activity. 4. In the primitive form contractile rhythm is an intrinsic property of cardiac muscle; its nerve supply regulates the rhythm, it does not initiate it. The beat is therefore myogenic, not neurogenic. 5. The contractile vascular system of annelids is mainly branchial in function. The vertebrate heart has been derived from it by the growing around of the lateral body folds to form a new ventral surface. PMID- 19871792 TI - ELECTRIFICATION OF WATER AND OSMOTIC PRESSURE. AB - 1. Amphoteric electrolytes form salts with both acids and alkalies. It is shown for two amphoteric electrolytes, Al(OH)(3) and gelatin, that in the presence of an acid salt water diffuses through a collodion membrane into a solution of these substances as if its particles were negatively charged, while water diffuses into solutions of these electrolytes, when they exist as monovalent or bivalent metal salts, as if the particles of water were positively charged. The turning point for the sign of the electrification of water seems to be near or to coincide with the isoelectric point of these two ampholytes which is a hydrogen ion concentration of about 2 x 10(-5)N for gelatin and about 10(-7) for Al(OH)(3). 2. In conformity with the rules given in a preceding paper the apparently positively charged water diffuses with less rapidity through a collodion membrane into a solution of Ca and Ba gelatinate than into a solution of Li, Na, K, or NH(4) gelatinate of the same concentration of gelatin and of hydrogen ions. Apparently negatively charged water diffuses also with less rapidity through a collodion membrane into a solution of gelatin sulfate than into a solution of gelatin chloride or nitrate of the same concentration of gelatin and of hydrogen ions. 3. If we define osmotic pressure as that additional pressure upon the solution required to cause as many molecules of water to diffuse from solution to the pure water as diffuse simultaneously in the opposite direction through the membrane, it follows that the osmotic pressure cannot depend only on the concentration of the solute but must depend also on the electrostatic effects of the ions present and that the influence of ions on the osmotic pressure must be the same as that on the initial velocity of diffusion. This assumption was put to a test in experiments with gelatin salts for which a collodion membrane is strictly semipermeable and the tests confirmed the expectation. PMID- 19871793 TI - THE HELIOTROPISM OF ONCHIDIUM: A PROBLEM IN THE ANALYSIS OF ANIMAL CONDUCT. PMID- 19871794 TI - THE COMBINATION OF ENZYME AND SUBSTRATE : I. A METHOD FOR THE QUANTITATIVE DETERMINATION OF PEPSIN. II. THE EFFECT OF THE HYDROGEN ION CONCENTRATION. AB - 1. A quantitative method for the determination of pepsin is described depending on the change in conductivity of a digesting egg albumin solution. 2. The combination of pepsin with an insoluble substrate has been followed by this method. 3. The amount of pepsin removed from solution by a given weight of substrate is independent of the size of the particles of the substrate. 4. There is an optimum zone of hydrogen ion concentration for the combination of enzyme and substrate corresponding to the optimum for digestion. 5. It is suggested that the pepsin combines largely or entirely with the ionized protein. PMID- 19871795 TI - LABYRINTH AND EQUILIBRIUM : I. A COMPARISON OF THE EFFECT OF REMOVAL OF THE OTOLITH ORGANS AND OF THE SEMICIRCULAR CANALS. AB - 1. A dogfish from which all six ampullae have been removed maintains its equilibrium; the righting reactions occur promptly; compensatory movements of the eyes occur in response to rotations in all planes except the horizontal; the compensatory position of the eyes is retained if the animal is held in an abnormal position. Both the static and dynamic functions of equilibrium continue, therefore, after complete removal of all the semicircular canals and all the ampullae. 2. After complete removal of the otoliths from the vestibules without injury to the ampullae the animal maintains its equilibrium in the water, rights itself promptly, and makes compensatory motions to rotations in all planes. If held in an abnormal position the compensatory position of the eyes is maintained. Both static and dynamic functions of equilibrium continue. 3. Destruction of both the semicircular canals and the otolith organs completely abolishes all compensatory movements and equilibrium reactions of labyrinthine origin. 4. It is pointed out that these observations do not justify the theory of Mach and Breuer that the ampullae and semicircular canals are the organs for the dynamic functions of equilibrium, and that the otoliths are the organs for the static functions of equilibrium. 5. The new experiments recorded in this paper show that the ampullae alone (without the otoliths) suffice for all the dynamic and all the static functions of equilibrium of the ear; and that the otolith organs (without the ampullae) suffice for all the static and for all the dynamic functions of equilibrium of the ear with the exception of the response to a rotation of the animal in a horizontal plane. PMID- 19871796 TI - STUDIES ON BIOLUMINESCENCE : X. CARBON DIOXIDE PRODUCTION DURING LUMINESCENCE OF CYPRIDINA LUCIFERIN. PMID- 19871797 TI - STUDIES ON BIOLUMINESCENCE : XI. HEAT PRODUCTION DURING LUMINESCENCE OF CYPRIDINA LUCIFERIN. PMID- 19871799 TI - IODINE AND THE THYROID : IV. QUANTITATIVE EXPERIMENTS ON IODINE FEEDING AND METAMORPHOSIS. PMID- 19871798 TI - THE ISOELECTRIC POINTS OF THE PROTEINS IN CERTAIN VEGETABLE JUICES. AB - The state in which a protein substance exists depends upon the nature of its combination with acids or bases and is changed by change in the protein compound. The nature of the compound of a protein that exists at any hydrogen ion concentration can be ascertained if the isoelectric point of the protein is known. Accordingly information regarding the isoelectric points of vegetable proteins is of importance for operations in which it may be desirable to change the state of protein substances, as in the dehydration of vegetables. The Protein in Potato Juice.-The hydrogen ion concentration of the filtered juice of the potato is in the neighborhood of 10(-7)N. Such juice contains the globulin tuberin to the extent of from 1 to 2 per cent. The character of the compound of tuberin that exists in nature was suggested by its anodic migration in an electric field. The addition of acid to potato juice dissociated this compound and liberated tuberin at its isoelectric point. The isoelectric point of tuberin coincided with a slightly lower hydrogen ion concentration than 10(-4)N. At that reaction it existed most nearly uncombined. The flow of current during cataphoresis was greatest in the neighborhood of the isoelectric point. This evidence supplements that of the direction of the migration of tuberin, since it also suggests the existence of the greatest number of uncombined ions near this point. At acidities greater than the isoelectric point tuberin combined with acid. The compound that was formed contained nearly three times as much acid as was needed to dissociate the tuberin compound that existed in nature. At such acidities tuberin migrated to the cathode. Though never completely precipitated tuberin was least soluble in the juice of the potato in the neighborhood of its isoelectric point. Both the compounds of tuberin with acids and with bases were more soluble in the juice than was uncombined tuberin. The nature of the slight precipitate that separated when potato juice was made slightly alkaline was not determined. The Protein in Carrot Juice.-The isoelectric point of the protein in carrot juice coincided with that of tuberin. Remarkably similar also were the properties of carrot juice and the juice of the potato. Existing in nature at nearly the same reaction they combined with acids and bases to nearly the same extent and showed minima in solubility at the same hydrogen ion concentrations. The greatest difference in behavior concerned the alkaline precipitate which, in the carrot, was nearly as great as the acid precipitate. The Protein in Tomato Juice.-The protein of the tomato existed in a precipitated form near its isoelectric point. Accordingly it was not present to any extent in filtered tomato juice. If, however, the considerable acidity at which the tomato exists was neutralized the protein dissolved and was filterable. It then migrated to the anode in an electric field. The addition of sufficient acid to make the hydrogen ion concentration slightly greater than 10(-5)N again precipitated the protein at its isoelectric point. At greater acidities migration was cathodic. PMID- 19871800 TI - INFLUENCE OF THE CONCENTRATION OF ELECTROLYTES ON THE ELECTRIFICATION AND THE RATE OF DIFFUSION OF WATER THROUGH COLLODION MEMBRANES. AB - 1. When a watery solution is separated from pure water by a collodion membrane, the initial rate of diffusion of water into the solution is influenced in an entirely different way by solutions of electrolytes and of non-electrolytes. Solutions of non-electrolytes, e.g. sugars, influence the initial rate of diffusion of water through the membrane approximately in direct proportion to their concentration, and this. influence begins to show itself under the conditions of our experiments when the concentration of the sugar solution is above M/64 or M/32. We call this effect of the concentration of the solute on the initial rate of diffusion of water into the solution the gas pressure effect. 2. Solutions of electrolytes show the gas pressure effect upon the initial rate of diffusion also, but it commences at a somewhat higher concentration than M/64; namely, at M/16 or more (according to the nature of the electrolyte). 3. Solutions of electrolytes of a lower concentration than M/16 or M/8 have a specific influence on the initial rate of diffusion of water through a collodion membrane from pure solvent into solution which is not found in the case of the solutions of non-electrolytes and which is due to the fact that the particles of water diffuse in this case through the membrane in an electrified condition, the sign of the charge depending upon the nature of the electrolyte in solution, according to two rules given in a preceding paper. 4. In these lower concentrations the curves representing the influence of the concentration of the electrolyte on the initial rate of diffusion of water into the solution rise at first steeply with an increase in the concentration, until a maximum is reached at a concentration of M/256 or above. A further increase in concentration causes a drop-in the curve and this drop increases with a further increase of concentration until that concentration of the solute is reached in which the gas pressure effect begins to prevail; i.e., above M/16. Within a range of concentrations between M/256 and M/16 or more (according to the nature of the electrolyte) we notice the reverse of what we should expect on the basis of van't Hoff's law; namely, that the attraction of a solution of an electrolyte for water diminishes with an increase in concentration. 5. We wish to make no definite assumption concerning the origin of the electrification of water and concerning the mechanism whereby ions influence the rate of diffusion of water particles through collodion membranes from pure solvent to solution. It will facilitate, however, the presentation of our results if it be permitted to present them in terms of attraction and repulsion of the charged particles of water by the ions. With this reservation we may say that in the lowest concentrations attraction of the electrified water particles by the ions with the opposite charge prevails over the repulsion of the electrified water particles by the ions with the same sign of charge as that of the water; while beyond a certain critical concentration the repelling action of the ion with the same sign of charge as that of the water particles upon the latter increases more rapidly with increasing concentration of the solute than the attractive action of the ion with the opposite charge. 6. It is shown that negative osmosis, i.e. the diminution of the volume of the solution of acids and of alkalies when separated by collodion membranes from pure water, occurs in the same range of concentrations in which the drop in the curves of neutral salts occurs, and that it is due to the same cause; namely, the repulsion of the electrified particles of water by the ion with the same sign of charge as that of the water. This conclusion is supported by the fact that negative osmosis becomes pronounced when the ion with the same sign of charge as that of the electrified particles of water carries more than one charge. PMID- 19871801 TI - THE ACTION OF STRYCHNINE AND NICOTINE ON THE NEUROMUSCULAR MECHANISM OF ASTERIAS. PMID- 19871803 TI - STUDIES ON BIOLUMINESCENCE : XII. THE ACTION OF ACID AND OF LIGHT IN THE REDUCTION OF CYPRIDINA OXYLUCIFERIN. PMID- 19871802 TI - THE CHROMOSOMES OF PARTHENOGENETIC FROGS. PMID- 19871804 TI - STUDIES ON ENZYME ACTION : XVIII. THE SACCHAROGENIC ACTIONS OF POTATO JUICE. AB - The saccharogenic enzymes present in potato juice were studied. The actions were followed upon the substances present in the juice and upon added sucrose, maltose, and soluble starch. Sucrase and amylase were found to be present in the juice. No indication of a maltase was obtained. The sucrase showed optimum conditions for action at pH 4 to 5, the amylase at pH 6 to 7, both upon the starch present in the juice and upon added soluble starch. The action of a yeast sucrase preparation upon the juice showed the presence of sucrose (or raffinose) in a concentration of the order of magnitude of 1 per cent. PMID- 19871805 TI - THE PHOTOCHEMICAL NATURE OF THE PHOTOSENSORY PROCESS. AB - 1. In order to produce a response in Mya, the minimum amount of light energy required is 5.62 meter candle seconds. This energy follows the Bunsen-Roscoe law for the relation between intensity and time of exposure. 2. The necessary minimum amount of energy varies but little with the temperature; the temperature coefficient for 10 degrees C. is 1.06. 3. In view of these facts it is concluded that the initial action of the light is photochemical in nature. This substantiates the hypothesis previously suggested to account for the mechanism of photoreception. 4. The constant energy requirement for stimulation of Mya shows that the traditional division of animals into those which respond to a constant source of light and those which respond to a rapidly augmented light is without any fundamental significance for sensory physiology. PMID- 19871807 TI - APPARATUS FOR MEASUREMENT OF OXIDASE AND CATALASE ACTIVITY. PMID- 19871806 TI - THE FREE ENERGY OF BIOLOGICAL PROCESSES : PRELIMINARY PAPER. PMID- 19871808 TI - INFLUENCE OF A SLIGHT MODIFICATION OF THE COLLODION MEMBRANE ON THE SIGN OF THE ELECTRIFICATION OF WATER. AB - 1. It is shown that collodion membranes which have received one treatment with a 1 per cent gelatin solution show for a long time (if not permanently) afterwards a different osmotic behavior from collodion membranes not treated with gelatin. This difference shows itself only towards solutions of those electrolytes which have a tendency to induce a negative electrification of the water particles diffusing through the membrane, namely solutions of acids, acid salts, and of salts with trivalent and tetravalent cations; while the osmotic behavior of the two types of membranes towards solutions of salts and alkalies, which induce a positive electrification of the water particles diffusing through the membrane, is the same. 2. When we separate solutions of salts with trivalent cation, e.g. LaCl(3) or AlCl(3), from pure water by a collodion membrane treated with gelatin, water diffuses rapidly into the solution; while no water diffuses into the solution when the collodion membrane has received no gelatin treatment. 3. When we separate solutions of acid from pure water by a membrane previously treated with gelatin, negative osmosis occurs; i.e., practically no water can diffuse into the solution, while the molecules of solution and some water diffuse out. When we separate solutions of acid from pure water by collodion membranes not treated with gelatin, positive osmosis will occur; i.e., water will diffuse rapidly into the solution and the more rapidly the higher the valency of the anion. 4. These differences occur only in that range of concentrations of electrolytes inside of which the forces determining the rate of diffusion of water through the membrane are predominantly electrical; i.e., in concentrations from 0 to about M/16. For higher concentrations of the same electrolytes, where the forces determining the rate of diffusion are molecular, the osmotic behavior of the two types of membranes is essentially the same. 5. The differences in the osmotic behavior of the two types of membranes are not due to differences in the permeability of the membranes for solutes since it is shown that acids diffuse with the same rate through both kinds of membranes. 6. It is shown that the differences in the osmotic behavior of the two types of collodion membranes towards solutions of acids and of salts with trivalent cation are due to the fact that in the presence of these electrolytes water diffuses in the form of negatively charged particles through the membranes previously treated with gelatin, and in the form of positively charged particles through collodion membranes not treated with gelatin. 7. A treatment of the collodion membranes with casein, egg albumin, blood albumin, or edestin affects the behavior of the membrane towards salts with trivalent or tetravalent cations and towards acids in the same way as does a treatment with gelatin; while a treatment of the membranes with peptone prepared from egg albumin, with alanine, or with starch has no such effect. PMID- 19871809 TI - INFLUENCE OF THE CONCENTRATION OF ELECTROLYTES ON SOME PHYSICAL PROPERTIES OF COLLOIDS AND OF CRYSTALLOIDS. AB - 1. When a 1 per cent solution of a metal gelatinate, e.g. Na gelatinate, of pH = 8.4 is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain rate which can be measured by the rise of the level of the liquid in a manometer. When to such a solution alkali or neutral salt is added the initial rate with which water will diffuse into the solution is diminished and the more so the more alkali or salt is added. This depressing effect of the addition of alkali and neutral salt is greater when the cation of the electrolyte added is bivalent than when it is monovalent. This seems to indicate that the depressing effect is due to the cation of the electrolyte added. 2. When a neutral M/256 solution of a salt with monovalent cation (e.g. Na(2)SO(4) or K(4)Fe(CN)(6), etc.) is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain initial rate. When to such a solution alkali or neutral salt is added, the initial rate with which water will diffuse into the solution is diminished and the more so the more alkali or salt is added. The depressing effect of the addition of alkali or neutral salt is greater when the cation of the electrolyte added is bivalent than when it is monovalent. This seems to indicate that the depressing effect is due to the cation of the electrolyte added. The membranes used in these experiments were not treated with gelatin. 3. It can be shown that water diffuses through the collodion membrane in the form of positively charged particles under the conditions mentioned in (1) and (2). In the case of diffusion of water into a neutral solution of a salt with monovalent or bivalent cation the effect of the addition of electrolyte on the rate of diffusion can be explained on the basis of the influence of the ions on the electrification and the rate of diffusion of electrified particles of water. Since the influence of the addition of electrolyte seems to be the same in the case of solutions of metal gelatinate, the question arises whether this influence of the addition of electrolyte cannot also be explained in the same way, and, if this be true, the further question can be raised whether this depressing effect necessarily depends upon the colloidal character of the gelatin solution, or whether we are not dealing in both cases with the same property of matter; namely, the influence of ions on the electrification and rate of diffusion of water through a membrane. 4. It can be shown that the curve representing the influence of the concentration of electrolyte on the initial rate of diffusion of water from solvent into the solution through the membrane is similar to the curve representing the permanent osmotic pressure of the gelatin solution. The question which has been raised in (3) should then apply also to the influence of the concentration of ions upon the osmotic pressure and perhaps other physical properties of gelatin which depend in a similar way upon the concentration of electrolyte added; e.g., swelling. 5. When a 1 per cent solution of a gelatin-acid salt, e.g. gelatin chloride, of pH 3.4 is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain rate. When to such a solution acid or neutral salt is added-taking care in the latter case that the pH is not altered-the initial rate with which water will diffuse into the solution is diminished and the more so the more acid or salt is added. Water diffuses into a gelatin chloride solution through a collodion membrane in the form of negatively charged particles. 6. When we replace the gelatin-acid salt by a crystalloidal salt, which causes the water to diffuse through the collodion membrane in the form of negatively charged particles, e.g. M/512 Al(2)Cl(6), we find that the addition of acid or of neutral salt will diminish the initial rate with which water diffuses into the M/512 solution of Al(2)Cl(6), in a similar way as it does in the case of a solution of a gelatin-acid salt. PMID- 19871810 TI - QUANTITATIVE LAWS IN REGENERATION. I. AB - 1. Equal masses of sister leaves of Bryophyllum calycinum produce equal masses of shoots and roots in equal time and under equal conditions. 2. The mass of shoots and roots produced by different masses of sister leaves in equal time and under equal conditions is approximately in direct proportion to the masses of the leaves. 3. When a piece of stem inhibits the production of shoots and roots in a leaf of Bryophyllum connected with it, the stem gains in mass and this gain in mass equals approximately the mass of shoots and roots the leaf would have produced if it had been detached from the stem. 4. This suggests that the inhibitory influence of the stem upon the formation of shoots and roots in the leaf is due to the fact that the material available for this process naturally flows into the stem. PMID- 19871811 TI - A DEVICE FOR REGULATING THE TEMPERATURE OF INCUBATORS EITHER ABOVE OR BELOW ROOM TEMPERATURE. PMID- 19871812 TI - CONCERNING THE HEREDITARY ADAPTATION OF ORGANISMS TO HIGHER TEMPERATURE. AB - 1. Imagos of Drosophila raised at temperatures of from 12-28.5 degrees C. when placed at any temperature from 15-32.5 degrees C. produce eggs which develop normally at these temperatures. 2. Imagos raised at temperatures of from 29-32.5 degrees and then kept permanently within these temperatures produce eggs which do not develop. 3. Imagos raised at from 28.5-32.5 degrees C. and then placed at temperatures of from 12-25 degrees C. produce eggs which develop normally. 4. Imagos raised at from 28.5-32.5 degrees C. placed at 15-25 degrees C. for 24 hours or longer and then put back into a temperature of from 28.5-32.5 degrees C., produce eggs which will develop at the latter temperature. 5. There is no evidence of any hereditary adaptation to higher temperatures. PMID- 19871813 TI - STEREOTROPISM AS A FUNCTION OF NEUROMUSCULAR ORGANIZATION. AB - From what has been said concerning the neuromuscular organization of the Asterias ray, it is possible to arrive at certain definite conclusions regarding the nature of the stereotropism of that organ. The righting movements from the start are not haphazard; i.e., they cannot be explained on any hypothesis of "trial and error." The excitation of the sensory cells of the dorsal sheath initiates dorsal flexure of the ray. This movement makes it possible for the tube feet of the tip to touch bottom and start the vigorous action which follows and completes the righting If the "feelers" by chance touch bottom they initiate the reaction de novo. As to the remaining phases, the stereotropic reaction of the ray is referable to the high degree of surface sensitivity of the tube feet disks and the propagation of excitatory and inhibitory impulses, resulting from stimulation, along appropriate paths to the muscles of the ray. In this respect the tube feet may be regarded as playing a role similar to that of tropistic receptors in general. That is, unequal stimulation of the receptors causes a corresponding inequality of tone or of contraction in the musculature which ultimately results in an equilibrium of orientation to the factor involved. It is evident that as a mechanism for righting stereotropism differs in one important respect from other tropisms. The latter depend for their operation upon unilateral effects in organisms which are dynamically bilaterally symmetrical. In stereotropism the sensitivity of the organism is not distributed in bilaterally symmetrical fashion. As a rule only the ventral side is stereosensitive; i.e., the sensitivity is unilaterally distributed. There is a tropistic action in such cases because of the fact that when the sensitive surface is only partially stimulated an unequal contraction of the musculature follows and this as a result brings the sensitive surface into such a position that it is all equally stimulated. Equal muscle tone follows and the organism is in equilibrium with its environment. PMID- 19871814 TI - REGENERATION AND NEOTENY. AB - It is apparently quite certain that removal of parts of the body (limbs, tail) followed by regeneration of these parts (1) does not produce neoteny in the larvae of salamanders, and (2) has no influence upon metamorphosis. PMID- 19871815 TI - COMPARATIVE STUDIES ON RESPIRATION : X. TOXIC AND ANTAGONISTIC EFFECTS OF MAGNESIUM IN RELATION TO THE RESPIRATION OF BACILLUS SUBTILIS. AB - 1. Concentrations of MgCl(2) up to 0.01 M have little effect upon the rate or respiration of Bacillus subtilis; at 0.03 M there is an increase in the rate, while in the higher concentrations there is a gradual decrease. 2. There is a well marked antagonism between MgCl(2) and NaCl, and a very slight antagonism between MgCl(2) and CaCl(2). PMID- 19871816 TI - INTENSITY AND THE PROCESS OF PHOTORECEPTION. AB - 1. In the photosensory process of Mya the latent period varies inversely as the intensity of the stimulating light. 2. Quantitative analysis of the data shows that the photochemical effect of the light is a logarithmic function of its intensity, the two variables being related to each other according to the well known "compound interest" law. 3. Comparison with previous experiments demonstrates that the Reciprocity Law of Bunsen and Roscoe applies to the photosensory process not only for the minimum energy required for a response, but for a much greater range of energy application as well. PMID- 19871817 TI - LABYRINTH AND EQUILIBRIUM : II. THE MECHANISM OF THE DYNAMIC FUNCTIONS OF THE LABYRINTH. PMID- 19871818 TI - STUDIES IN THE DYNAMICS OF HISTOGENESIS : I. TENSION OF DIFFERENTIAL GROWTH AS A STIMULUS TO MYOGENESIS. AB - 1. The region of most active mitosis per mm. of cross-section in the intestine is the entodermal epithelial tube. The mitotic figures primarily follow the path of a right-handed helix. In one of the twenty embryos the mitotic figures describe the path of a right-handed helix. 2. The region of least active or relatively passive growth per mm. of cross-section is the mesenchyme, derived from the splanchnic mesoderm surrounding the epithelial tube. 3. The rapid expansion, due to epithelial growth in a rotating spiral manner, of the intestinal lumen is greater than the activity manifest in the surrounding mesenchyme. This causes a pressure in the latter resulting in a flattening and elongation of the mesenchymal cells. The successive changes in shape of these cells through the spherical, ellipsoidal, and spindle cellular phases are seen. The mesenchymal wall decreases in thickness, due to tension caused by epithelial tubular dilation. 4. The rotating spiral growth of the epithelial cells causes the formation of a series of mesenchymal cellular and fibrillar concentric rings due to the centripetal force of the former. 5. The circular, smooth muscle cells are differentiated in the outer, more condensed margins of the ring. At these points the developing tensional stresses are greater than within the ring. 6. The inner circular smooth muscle coat is the first one differentiated and is incident to the rapid growth of the epithelial tube in diameter. The former soon tends to restrict the growth of the epithelial tube in diameter. The tube, pursuing the lines of least resistance, grows in length. During the period of rapid growth in length the outer longitudinal muscle coat is in the process of formation. 7. The tensional stresses to which the elongated strained mesenchymal cells are subjected appear to be a dynamic stimulus to smooth muscle differentiation. 8. From this study of a closely graded and progressive series of sections of intestinal development, the conclusion is drawn that muscle tissue is not self differentiating, in the strict sense of the term, but that the tension of differential growth acts as the stimulus to smooth muscle differentiation. PMID- 19871819 TI - THE NATURE OF THE DIRECTIVE INFLUENCE OF GRAVITY ON THE ARRANGEMENT OF ORGANS IN REGENERATION. AB - 1. When leaves of Bryophyllum calycinum are suspended in moist air in a vertical plane and sidewise, roots and shoots are formed exclusively or predominate in the notches on the lower side of the leaves. When pieces of stems of the same plant are suspended horizontally in moist air, roots develop on the lower side of the stem, with the exception of the extreme basal end where they may develop on both sides. 2. The writer has suggested in a preceding paper that this directive influence of gravity on the arrangement of the regenerating organs may be due to the combination of two factors. The first factor is gravity, which causes a slightly greater collection of sap on the lower side of these organs, and as a consequence roots develop a little more quickly on the lower than on the upper side. The second factor is of an inhibitory character inasmuch as quite generally organs which grow out first, or which grow quickly, have a tendency to retard or inhibit the growth of similar organs in other places. 3. The writer was able to prove the action of this inhibitory factor by cutting off the lower edges of leaves suspended sidewise in a vertical plane or the lower halves of stems suspended in a horizontal plane (in moist air). In this case roots developed as abundantly on the upper side of these organs as they otherwise would have developed on the lower side. 4. It was, however, still necessary to prove the idea that gravity causes sap to collect in larger quantity in the lower parts of organs. This gap is filled by the present paper in which it is shown, first, that in the leaves suspended in moist air a red pigment is formed which has a tendency to collect gradually in the lowest parts of the leaf when the latter is suspended in a vertical plane. This red pigment serves as an indicator for the distribution of sap in the leaf and thus shows directly the tendency of the sap to collect in greater abundance on the lower edge of a leaf suspended in a vertical plane. Second, it is shown that when leaves or stems of Bryophyllum are suspended, in the way described, under water instead of in moist air, roots develop on the upper side as well as on the lower side. The directive effect of gravity upon the arrangement of organs disappears in this case since the abundance of the outside water makes the effect of a slight difference in the distribution of sap between the upper and lower side a negligible factor. Third, it is shown that the dry weight of the lower half of leaves suspended sidewise for several weeks in moist air in a vertical plane is greater than that of the upper half when roots and shoots are formed on the lower side only. This indicates that material from the upper half flows into the growing organs of the lower half. No such difference between upper and lower half of leaf is found when the leaves are suspended in the same way in water and roots and shoots are formed on both sides of the leaf. 5. It is shown that when a leaf connected with a piece of stem is suspended in moist air the red pigment goes into the stem instead of collecting in the lower part of the leaf, thus supporting the view expressed in a preceding paper that the inhibitory action of the stem on the root and shoot formation in a leaf of Bryophyllum is due to the fact that the material available in the leaf for organ formation is naturally sent into the stem. PMID- 19871820 TI - ON THE CAUSE OF THE INFLUENCE OF IONS ON THE RATE OF DIFFUSION OF WATER THROUGH COLLODION MEMBRANES. I. AB - 1. In three previous publications it had been shown that electrolytes influence the rate of diffusion of pure water through a collodion membrane into a solution in three different ways, which can be understood on the assumption of an electrification of the water or the watery phase at the boundary of the membrane; namely, (a) While the watery phase in contact with collodion is generally positively electrified, it happens that, when the membrane has received a treatment with a protein, the presence of hydrogen ions and of simple cations with a valency of three or above (beyond a certain concentration) causes the watery phase of the double layer at the boundary of membrane and solution to be negatively charged. (b) When pure water is separated from a solution by a collodion membrane, the initial rate of diffusion of water into a solution is accelerated by the ion with the opposite sign of charge and retarded by the ion with the same sign of charge as that of the water, both effects increasing with the valency of the ion and a second constitutional quantity of the ion which is still to be defined. (c) The relative influence of the oppositely charged ions, mentioned in (b), is not the same for all concentrations of electrolytes. For lower concentrations the influence of that ion usually prevails which has the opposite sign of charge from that of the watery phase of the double layer; while in higher concentrations the influence of that ion begins to prevail which has the same sign of charge as that of the watery phase of the double layer. For a number of solutions the turning point lies at a molecular concentration of about M/256 or M/512. In concentrations of M/8 or above the influence of the electrical charges of ions mentioned in (b) or (c) seems to become less noticeable or to disappear entirely. 2. It is shown in this paper that in electrical endosmose through a collodion membrane the influence of electrolytes on the rate of transport of liquids is the same as in free osmosis. Since the influence of electrolytes on the rate of transport in electrical endosmose must be ascribed to their influence on the quantity of electrical charge on the unit area of the membrane, we must conclude that the same explanation holds for the influence of electrolytes on the rate of transport of water into a solution through a collodion membrane in the case of free osmosis. 3. We may, therefore, conclude, that when pure water is separated from a solution of an electrolyte by a collodion membrane, the rate of diffusion of water into the solution by free osmosis is accelerated by the ion with the opposite sign of charge as that of the watery phase of the double layer, because this ion increases the quantity of charge on the unit area on the solution side of the membrane; and that the rate of diffusion of water is retarded by the ion with the same sign of charge as that of the watery phase for the reason that this ion diminishes the charge on the solution side of the membrane. When, therefore, the ions of an electrolyte raise the charge on the unit area of the membrane on the solution side above that on the side of pure water, a flow of the oppositely charged liquid must occur through the interstices of the membrane from the side of the water to the side of the solution (positive osmosis). When, however, the ions of an electrolyte lower the charge on the unit area of the solution side of the membrane below that on the pure water side of the membrane, liquid will diffuse from the solution into the pure water (negative osmosis). 4. We must, furthermore, conclude that in lower concentrations of many electrolytes the density of electrification of the double layer increases with an increase in concentration, while in higher concentrations of the same electrolytes it decreases with an increase in concentration. The turning point lies for a number of electrolytes at a molecular concentration of about M/512 or M/256. This explains why in lower concentrations of electrolytes the rate of diffusion of water through a collodion membrane from pure water into solution rises at first rapidly with an increase in concentration while beyond a certain concentration (which in a number of electrolytes is M/512 or M/256) the rate of diffusion of water diminishes with a further increase in concentration. PMID- 19871821 TI - THE EFFECT OF TEMPERATURE UPON FACET NUMBER IN THE BAR-EYED MUTANT OF DROSOPHILA : PART I. PMID- 19871822 TI - THE EFFECT OF TEMPERATURE UPON FACET NUMBER IN THE BAR-EYED MUTANT OF DROSOPHILA : PART II. PMID- 19871823 TI - THE EFFECT OF TEMPERATURE UPON FACET NUMBER IN THE BAR-EYED MUTANT OF DROSOPHILA : PART III. AB - Three strains of the bar-eyed mutant of Drosophila melanogaster Meig have been reared at constant temperatures over a range of 15-31 degrees C. The mean facet number in the bar-eyed mutant varies inversely with the temperature at which the larvae develop. The temperature coefficient (Q(10)) is of the same order as that for chemical reactions. The facet-temperature relations may be plotted as an exponential curve for temperatures from 15-31 degrees . The rate of development of the immature stages gives a straight line temperature curve between 15 and 29 degrees . Beyond 29 degrees the rate decreases again with a further rise in temperature. The facet curve may be readily superimposed on the development curve between 15 and 27 degrees . The straight line feature of the development curve is probably due to the flattening out of an exponential curve by secondary factors. Since both the straight line and the exponential curve appear simultaneously in the same living material, it is impractical to locate the secondary factors in enzyme destruction, differences in viscosity, or in the physical state of colloids. Differential temperature coefficients for the various separate processes involved in development furnish the best basis for an explanation of the straight line feature of the curve representing the effect of temperature on the rate of physiological processes. Facet number in the full-eyed wild stock is not affected by temperature to a marked degree. The mean facet number for fifteen full-eyed females raised at 27 degrees is 859.06. The mean facet number for the Low Selected Bar females at 27 degrees is 55.13; for the Ultra-bar females at 27 degrees it is 21.27. A consistent sexual difference appears in all the bar stocks, the females having fewer facets. This relation may be expressed by the sex coefficient, the average value of which is 0.791. The average observed difference in mean facet number for a difference of 1 degrees C. in the environment in which the flies developed is 3.09 for the Ultra-bar stock and 14.01 for the Low Selected stock. The average proportional differences in the mean for a difference of 1 degrees C. are 9.22 per cent for Ultra-bar, and 14.51 for Low Selected. The differences in the number of facets per degrees C. are greatest at the low and least at the high temperatures. The difference in the number of facets per degrees C. varies with the mean. The proportional differences in the mean per degrees C. are greatest at the lower (15-17.5 degrees ) and higher (29-31 degrees ) temperatures and least at the intermediate temperatures. Temperature is a factor in determining facet number only during a relatively short period in larval development. This effective period, at 27 degrees , comes between the end of the 3rd and the end of the 4th day. At 15 degrees , this period is initiated at the end of 8 days following a 1st day at 27 degrees . At 27 degrees this period is approximately 18 hours long. At 15 degrees it is approximately 72 hours long. The number of facets and the length of the immature stage (egg-larval-pupal) appear related when the whole of development is passed at one temperature. That the number of facets is not dependent upon the length of the immature stage is shown by experiments in which only a part of development was passed at one temperature and the remainder at another. Temperature affects the reaction determining the number of facets in approximately the same way that it affects the other developmental reactions, hence the apparent correlation between facet number and the length of the immature stage. Variability as expressed by the coefficient of variability has a tendency to increase with temperature. Standard deviation, on the other hand, appears to decrease with rise in temperature. Neither inheritance nor induction effects are exhibited by this material. This study shows that environment may markedly affect the somatic expression of one Mendelian factor (bar eye), while it has no visible influence on another (white eye). PMID- 19871824 TI - THE INFLUENCE OF HYDROGEN ION CONCENTRATION ON THE INACTIVATION OF PEPSIN SOLUTIONS. AB - 1. Pepsin in solution at 38 degrees C. is most stable at a hydrogen ion concentration of about 10(-5) (pH 5.0). 2. Increasing the hydrogen ion concentration above pH 5.0 causes a slow increase in the rate of destruction of pepsin. 3. Decreasing the hydrogen ion concentration below pH 5.0 causes a very rapid increase in the rate of destruction of the enzyme. 4. Neither the purity of the enzyme solution nor the anion of the acid used has any marked effect on the rate of destruction or on the zone of hydrogen ion concentration in which the enzyme is most stable. 5. The existence of an optimum range of hydrogen ion concentration for the digestion of proteins by pepsin cannot be explained by the destruction of the enzyme by either too weak or too strong acid. PMID- 19871825 TI - THE EFFECT OF THE CONCENTRATION OF ENZYME ON THE RATE OF DIGESTION OF PROTEINS BY PEPSIN. AB - 1. In certain cases the rate of digestion of proteins by pepsin is not proportional to the total concentration of pepsin. 2. It is suggested that this is due to the fact that the enzyme in solution is in equilibrium with another substance (called peptone for convenience) and that the equilibrium is quantitatively expressed by the law of mass action, according to the following equation. See PDF for Equation It is assumed that only the uncombined pepsin affects the hydrolysis of the protein. 3. The hypothesis has been put in the form of a differential equation and found to agree quantitatively with the experimental results when the concentration of pepsin, peptone, or both is varied. 4. Pepsin inactivated with alkali enters the equilibrium to the same extent as active pepsin. 5. Under certain conditions (concentration of peptone large with respect to pepsin, and concentration of substrate relatively constant) the relative change in the amount of active pepsin is inversely proportional to the concentration of peptone and the equation simplifies to Schutz's rule. 6. An integral equation is obtained which holds for the entire course of the digestion (except for the first few minutes) with varying enzyme concentration. This equation is identical in form with the one derived by Arrhenius for the action of ammonia on ethyl acetate. 7. It is pointed out that there are many analogies between the action of pepsin on albumin solutions and the action of toxins on an organism. PMID- 19871826 TI - THE DARK ADAPTATION OF THE HUMAN EYE. AB - During the dark adaptation of the human eye, its visual threshold decreases to a small fraction of its original value in the light. An analysis of the quantitative data describing this adaptation shows that it follows the course of a bimolecular chemical reaction. On the basis of these findings it is suggested that visual reception in dim light is conditioned by a reversible photochemical reaction involving a photosensitive substance and its two products of decomposition. Accordingly, dark adaptation depends on the course of the "dark" reaction during which the two products of decomposition reunite to synthesize the original photosensitive substance. PMID- 19871827 TI - THE SIGNIFICANCE OF THE CAMBIUM IN THE STUDY OF CERTAIN PHYSIOLOGICAL PROBLEMS. AB - 1. The adjacent, undifferentiated, uninucleated cells of the lateral meristem or cambium are of two distinct shapes and sizes: (1) small, more or less isodiametric initials which are of the same general order of magnitude as the cells of the terminal meristem and embryo; and (2) large, elongated initials which in certain cases may attain a length of more than 10,000 micra and a volume of 10,000,000 cubic micra. The large initials may be induced to divide to form small initials, and the latter to regenerate elongated cells of normal dimensions. Thus, the cambium affords an unusually favorable medium for the study of a number of fundamental physiological and cytological problems. 2. A study of the cambium reveals the fact that there is a very-much greater variability in the size of meristematic cells in plants than was suspected by Sachs or Strasburger, and that the working sphere of the nucleus is by no means so restricted as assumed by these investigators. 3. Although the larger cambial initials of Pinus strobus tend to have larger nuclei, the nucleocytoplasmic-relation varies within wide limits and the diploid number of chromosomes is constant. The conditions in the cambium do not support Winkler's view that there is a close correlation between chromosomal number (chromosomal mass) and cell size in the somatic tissue of plants, and that giant cells are hyperchromatic. 4. The process of cell plate formation in the cambium is a remarkable phenomenon, and one which is significant in discussing the relative merits of various theories concerning the dynamics of karyokinesis and cytokinesis. 5. The newly formed partition membranes in the cambial initials frequently intersect the side walls at angles of varying degrees of acuteness, which is in contradiction to Errera's (Plateau's) Law of Minimal Area. PMID- 19871828 TI - A QUANTITATIVE STUDY OF THE EFFECT OF ANIONS ON THE PERMEABILITY OF PLANT CELLS. PMID- 19871829 TI - THE ANTAGONISTIC ACTION OF ANIONS. PMID- 19871830 TI - THE NATURE OF THE GROWTH RATE. AB - 1. The growth rate of organisms may be considered as a chemical reaction which gives the mature organism as its end-product. The organism grows at a definite rate which is, at any moment, proportional to the amount of growth yet to be made. 2. Shoots of young pear trees measured at weekly intervals during the growing season showed a rate similar to that of an autocatalytic reaction. 3. Young walnut trees showed distinct cycles of growth in a single season, but the growth in each cycle proceeded at a rate corresponding to an autocatalytic reaction. 4. The growth rate follows a definite, quantitative course though judged by different criteria. Data are presented for maize in which green weight, dry weight, and height of the plant are used. Data for cattle show that either weight or height of the animal may be used as a criterion. PMID- 19871831 TI - ON THE CAUSE OF THE INFLUENCE OF IONS ON THE RATE OF DIFFUSION OF WATER THROUGH COLLODION MEMBRANES. II. AB - 1. It had been shown in previous publications that when pure water is separated from a solution of an electrolyte by a collodion membrane the ion with the same sign of charge as the membrane increases and the ion with the opposite sign of charge as the membrane diminishes the rate of diffusion of water into the solution; but that the relative influence of the oppositely charged ions upon the rate of diffusion of water through the membrane is not the same for different concentrations. Beginning with the lowest concentrations of electrolytes the attractive influence of that ion which has the same sign of charge as the collodion membrane upon the oppositely charged water increases more rapidly with increasing concentration of the electrolyte than the repelling effect of the ion possessing the opposite sign of charge as the membrane. When the concentration exceeds a certain critical value the repelling influence of the latter ion upon the water increases more rapidly with a further increase in the concentration of the electrolyte than the attractive influence of the ion having the same sign of charge as the membrane. 2. It is shown in this paper that the influence of the concentration of electrolytes on the rate of transport of water through collodion membranes in electrical endosmose is similar to that in the case of free osmosis. 3. On the basis of the Helmholtz theory of electrical double layers this seems to indicate that the influence of an electrolyte on the rate of diffusion of water through a collodion membrane in the case of free osmosis is due to the fact that the ion possessing the same sign of charge as the membrane increases the density of charge of the latter while the ion with the opposite sign diminishes the density of charge of the membrane. The relative influence of the oppositely charged ions on the density of charge of the membrane is not the same in all concentrations. The influence of the ion with the same sign of charge increases in the lowest concentrations more rapidly with increasing concentration than the influence of the ion with the opposite sign of charge, while for somewhat higher concentrations the reverse is true. PMID- 19871832 TI - THE REVERSAL OF THE SIGN OF THE CHARGE OF MEMBRANES BY HYDROGEN IONS. AB - 1. It had been shown in previous papers that when a collodion membrane has been treated with a protein the membrane assumes a positive charge when the hydrogen ion concentration of the solution with which it is in contact exceeds a certain limit. It is pointed out in this paper that by treating the collodion membrane with a protein (e.g. oxyhemoglobin) a thin film of protein adheres to the membrane and that the positive charge of the membrane must therefore be localized in this protein film. 2. It is further shown in this paper that the hydrogen ion concentration, at which the reversal in the sign of the charge of a collodion membrane treated with a protein occurs, varies in the same sense as the isoelectric point of the protein, with which the membrane has been treated, and is always slightly higher than that of the isoelectric point of the protein used. 3. The critical hydrogen ion concentration required for the reversal seems to be, therefore, that concentration where enough of the protein lining of the membrane is converted into a protein-acid salt (e.g. gelatin nitrate) capable of ionizing into a positive protein ion (e.g. gelatin) and the anion of the acid used (e.g. NO(3)). PMID- 19871833 TI - THE INFLUENCE OF THE SUBSTRATE CONCENTRATION ON THE RATE OF HYDROLYSIS OF PROTEINS BY PEPSIN. AB - 1. It is pointed out that the apparent exceptions to the law of mass action found in enzyme reactions may be found in catalytic reactions in strictly homogeneous solutions. 2. These deviations in the rate of reaction from the law of mass action may be explained by the hypothesis that the active mass of the reacting substances is not directly proportional to the total concentration of substance taken. 3. In support of this suggestion it is shown that for any given concentration of pepsin the relative rate of digestion of concentrated and of dilute protein solutions is always the same. If the rate of digestion depended on the saturation of the surface of the enzyme by substrate the relative rate of digestion of concentrated protein solutions should increase more rapidly with the concentration of enzyme than that of dilute solutions. This was found not to be true, even when the enzyme could not be considered saturated in the dilute protein solutions. 4. The rate of digestion and the conductivity of egg albumin solutions of different concentration were found to be approximately proportional at the same pH. This agrees with the hypothesis first expressed by Pauli that the ionized protein is largely or entirely the form which is attacked by the enzyme. 5. The rate of digestion is diminished by a very large increase in the viscosity of the protein solution. This effect is probably a mechanical one due to the retardation of the diffusion of the enzyme. PMID- 19871834 TI - ENZYME ACTION IN ECHINODONTIUM TINCTORIUM ELLIS AND EVERHART. AB - In Echinodontium tinctorium the presence of the following enzymes was demonstrated: esterase, maltase, lactase, sucrase, raffinase, diastase, inulase, cellulase, hemicellulase, urease, rennet, and catalase. PMID- 19871835 TI - COMPARATIVE STUDIES ON RESPIRATION : XI. THE EFFECT OF HYDROGEN ION CONCENTRATION ON THE RESPIRATION OF PENICILLIUM CHRYSOGENUM. AB - 1. Variations in pH value between 4 and 8 produce practically no effect on the normal rate of respiration (the rate at neutrality is called normal). 2. Increasing the pH value to 8.80 causes respiration to fall to 60 per cent of the normal, after which it remains stationary for the duration of the experiment. 3. Decreasing the pH value to 2.65 causes a gradual rise and a gradual return to normal; at pH 1.10 to 1.95 the preliminary rise amounts to 20 per cent and is followed by a fall to below the normal. 4. The decrease in respiration brought about by solutions of a pH value of 1.95 or less are irreversible, while a similar decrease which occurs at pH 8.80 is reversible, the rate coming back to practically normal after the material is replaced in a neutral solution. 5. Determinations by means of Winkler's method showed an increase in the consumption of oxygen in acid solutions and a decrease in alkaline solutions. PMID- 19871836 TI - THE ANALYSIS OF NEUROMUSCULAR MECHANISMS IN CHITON. AB - 1. The degree of curvature of the body and of the girdle of a Chiton is determined by the activity of antagonistic muscle groups. At a certain, early stage in the strychninization of a Chiton the reciprocal inhibition involved in the natural use of these muscle groups is reversed, such that extensor muscles, rather than, as normally, flexor muscles, contract as the result of stimulation. This condition involves a reversal, under strychnine, of the normally positive stereotropism of the foot, and of the usual response of the mollusk to an increased illumination of its ventral surface. Strychnine reversal of this character is not a matter of the relative strength of the opposed muscle groups, for the flexor muscles are the more powerful and are the ones always shortened in tetanic contraction. 2. Nicotine, in contrast to strychnine, primarily induces contraction of flexor muscles. Its effects, moreover, are in a degree selective, being notably exerted on "cerebral" nervous structures. Curare is devoid of characteristic action on the neuromuscular responses of Chiton. 3. The chemical organization of the neuromuscular organs of Chiton, as far as revealed by these tests, corresponds to a more simple condition than is inferred for gastropods. In particular, the behavior with respect to curare resembles more that of the neuromuscular apparatus of flatworms. PMID- 19871837 TI - THE KINETICS OF THE ACTION OF CATALASE EXTRACT FROM MARINE ALGAE, WITH A NOTE ON OXIDASE. AB - Ulva taeniata contains oxidase. The existence of peroxidase is not proved. PMID- 19871838 TI - QUANTITATIVE LAWS IN REGENERATION. II. AB - This paper contains the results of a reexamination of a law expressed in a previous paper; namely, that when a piece of stem inhibits the growth of shoots and roots in a leaf connected with it the dry weight of the stem increases and that this gain equals approximately the mass of shoots and roots the leaf would have produced if it had been detached from the stem. This has been confirmed and it has been shown that the gain of the stem as a rule even exceeds slightly the mass of shoots and roots the leaf would have produced if it had not been inhibited by the stem. This supports the idea that the inhibitory influence of the stem upon the formation of roots and shoots in the leaf is due to the fact that the material available and required for this process naturally flows into the stem. PMID- 19871839 TI - THE REVERSAL OF THE SIGN OF THE CHARGE OF COLLODION MEMBRANES BY TRIVALENT CATIONS. AB - 1. Trivalent cations cause a collodion membrane covered with a protein film to be charged positively while they do not produce such an effect on collodion membranes not possessing a protein film. The same had been found for the reversal of the sign of charge of the membrane by acid. 2. This reversal in the sign of charge of the membrane by trivalent cations occurs on the alkaline side of the isoelectric point of the protein used; while the reversal by acid occurs on the acid side of the isoelectric point. 3. The reversal seems to be due to or to be accompanied in both cases by a chemical change in the protein. The chemical change which occurs when the hydrogen ions reverse the sign of charge of the protein film consists in the formation of a protein-acid salt whereby the H ion becomes part of a complex protein cation; while the chemical change which occurs when trivalent cations reverse the sign of charge of the protein film consists in the formation of an insoluble and therefore sparingly or non-ionizable metal proteinate. PMID- 19871840 TI - IONIC RADIUS AND IONIC EFFICIENCY. AB - 1. It has been shown in preceding papers that when we separate solutions of electrolytes from pure water by collodion membranes the ions with the same sign of charge as the membrane increase while the ions with the opposite sign of charge diminish the rate of diffusion of water from the side of pure water to the side of solution; and that the accelerating and depressing effects of these ions on the rate of diffusion of water increase with their valency. 2. It is shown in this paper that aside from the valency a second quantity of the ion plays a role in this effect, namely the radius, which in a monatomic ion means the distance between the central positive nucleus and the outermost ring or shell of electrons of the ion. In monatomic, monovalent anions the radius increases in the order Cl< Br< I (being largest in I), while for monatomic, monovalent cations it increases in the order Li< Na< K< Rb (being largest in Rb). 3. It is shown that the accelerating as well as the depressing effect of the anions mentioned increases directly with the order of magnitude of their radius and that the efficiency is greatest in the case of I which has the largest radius; while the accelerating as well as the depressing effect of cations increases inversely with the order of magnitude of their radius, Li with the smallest radius having the greatest efficiency. 4. This is intelligible on the assumption that the action of the ions is electrostatic in character, in the case of cations due to the electrostatic effect of the excess charge of their positive nucleus, and in the case of anions due to the excess charge of their captured electron. The electrostatic effect of the positive nucleus of a cation on the membrane (or any other body) will be the greater the smaller the ionic radius of the cation; and the electrostatic effect of an excess electron will be the greater the further its distance from its own positive nucleus. 5. It is suggested that this rule may possibly include polyatomic, monovalent ions (e.g. NO(3), CNS, etc.) when we replace these polyatomic ions by monatomic models in which the radius is calculated in such a way as to give the model the same electrostatic effect which the polyatomic ion possesses. 6. These conclusions are in harmony with the fact that the efficiency of ions increases also with their valency. 7. It is suggested that these rules concerning the influence of the ionic radius can possibly be demonstrated in other phenomena, depending on the electrostatic effect of ions. PMID- 19871841 TI - PHOTOCHEMISTRY OF VISUAL PURPLE : I. THE KINETICS OF THE DECOMPOSITION OF VISUAL PURPLE BY LIGHT. AB - 1. Visual purple solutions are prepared under such conditions that the bleaching reaction is irreversible. 2. A method is described for the colorimetric estimation of very small quantities of visual purple. By this means the kinetics of the bleaching reaction are investigated. 3. The results show that the course of the decomposition follows that of a monomolecular reaction, without any measurable period of induction or after effect. PMID- 19871842 TI - THE RECOVERY OF TRANSMISSIVITY IN PASSIVE IRON WIRES AS A MODEL OF RECOVERY PROCESSES IN IRRITABLE LIVING SYSTEMS : PART I. PMID- 19871843 TI - THE MECHANISM OF INJURY AND RECOVERY. PMID- 19871844 TI - INHIBITORY ACTION OF PARATYPHOID BACILLI ON THE FERMENTATION OF LACTOSE BY BACILLUS COLI. I. AB - Bacteria of the paratyphoid group may be divided into two classes according to the behavior of 4 day cultures in lactose bouillon after a second inoculation with certain types of Bacillus coli. One class includes all true hog-cholera bacilli, the other nearly all true paratyphoid and enteriditis types. Under the imposed conditions Bacillus coli produces the usual amount of gas in the presence of the first group. In the presence of the second no gas or only a bubble appears. The production of acid is not interfered with. The significance of the inhibition was investigated in a variety of ways suggested by the particular hypothesis entertained at the time. Two main possibilities presented themselves; first, the direct association of the inhibition with living paratyphoid bacilli, and, second, the existence of a ferment or other product of growth as the inhibiting agent. The theory that the living bacilli or those killed at the lowest possible temperature are responsible was favored by a number of experiments. Thus the complete removal of bacteria by filtration, or by centrifugation combined with the use of kaolin to produce a clear fluid restored gas production. The presence of a fine cloud of bacteria was sufficient to inhibit. On the other hand, the addition of large numbers of living bacteria from agar slants or from lactose bouillon after the requisite incubation period to fresh lactose bouillon failed to inhibit gas production when Bacillus coli was added simultaneously. When the inhibiting culture was heated at 62 degrees C. for 35 minutes to sterilize it, gas production was still largely inhibited. But it was restored when higher temperatures were used, completely at 100 degrees C. and above. It was also gradually restored by exposing the heated culture to 37 degrees C. for 3 or more days. The presence of variable amounts of lactose, or even the complete absence of lactose did not interfere with the development of the inhibitory factor. The activity of the inhibition factor presents itself in the form of a curve, beginning at 0 when both paratyphoid and colon bacilli are inoculated simultaneously and rising as Bacillus coli is inoculated at longer intervals from the paratyphoid bacilli. The maximum of inhibition is reached at about the 4th day; thereafter it remains at the same level for a few days and then gradually falls until it is lost within 3 or 4 weeks. The curve of the hog cholera group is delayed in that the maximum inhibition is reached at the end of 3 weeks. These curves have not been accurately determined. Taking into consideration all the accumulated data the writers tentatively present the hypothesis that the inhibitory factor is some metabolic product of the paratyphoid bacillus, possibly an enzyme, which is destroyed at a temperature somewhat above the thermal death point of the bacilli and which more gradually disappears from incubated cultures. The substance fails to pass Berkefeld filters. It is carried down mechanically with substances clearing the culture fluid. The experiments support current theories which hold that the acid producing and gas-producing entities in cultures are distinct. PMID- 19871845 TI - COMPARATIVE STUDIES ON RESPIRATION : XII. A COMPARISON OF THE PRODUCTION OF CARBON DIOXIDE BY PENICILLIUM AND BY A SOLUTION OF DEXTROSE AND HYDROGEN PEROXIDE. AB - A neutral solution of dextrose and hydrogen peroxide acts like Penicillium chrysogenum in producing an increased amount of CO(2) upon the addition of acid, but not upon the addition of alkali. PMID- 19871846 TI - DYNAMICS OF NERVE CELLS : I. THE TEMPERATURE COEFFICIENT OF THE NEUROGENIC RHYTHM OF THE HEART OF LIMULUS POLYPHEMUS. AB - In the case of the heart of Limulus polyphemus the same magnitude and variation of the temperature coefficient (Q(10)) is obtained from the whole heart as from the ganglion alone. From the magnitude of the temperature coefficients and their variation with changes of temperature we may conclude that the rate of the heart beat is determined by alteration of chemical processes in the ganglion cells. PMID- 19871847 TI - DYNAMICS OF NERVE CELLS : II. THE TEMPERATURE COEFFICIENTS OF CARBON DIOXIDE PRODUCTION BY THE HEART GANGLION OF LIMULUS POLYPHEMUS. AB - 1. It is possible to determine by the colorimetric method the rate of production of carbon dioxide by the cardiac ganglion of Limulus. 2. Carbon dioxide formation in the cardiac ganglion was found to run parallel to the rate of heart beat for different temperatures. 3. The conclusion seems justified that the rate of cardiac rhythm of Limulus depends upon a chemical reaction in the nerve cells of the cardiac ganglion and that this reaction is associated with the production of carbon dioxide since the rate of beat and the rate of CO(2) production are similarly affected by changes in temperature. PMID- 19871848 TI - ON THE ROLE OF AN INTEGUMENTARY PIGMENT IN PHOTORECEPTION IN HOLOTHURIA. PMID- 19871849 TI - STUDIES IN THE DYNAMICS OF HISTOGENESIS : II. TENSION OF DIFFERENTIAL GROWTH AS A STIMULUS TO MYOGENESIS IN THE ESOPHAGUS. AB - Esophageal Development. 1. The region of most active mitosis per mm. of cross section in the esophagus is the entodermal epithelial tube. The mitotic figures follow a spiral path in the manner of a left-handed helix from the cephalic to the caudal direction. 2. The region of least active growth per mm. of cross section in the esophagus is the mesenchyme surrounding the epithelial tube. 3. The helicoidal activity of the epithelial tube causes a vortical reaction in the surrounding mesenchyme. The mesenchymal whirlpool represents a reaction to the spirally grooving epithelial tube. 4. In embryos 9.5 to 14 mm. in length the esophageal epithelial tube grows relatively more rapidly in width than in length. During this period the myoblasts which form the inner, close spiral, muscle coat of the esophagus are becoming rapidly differentiated in the outer condensed margin of the mesenchymal maelstrom. 5. The nuclei, first spherical then oval, and finally rod shaped with rounded ends, are drawn out in the direction of the circumference of the mesenchymal rim which is directed tangentially. 6. The cytoplasm is also drawn out in the direction of the mesenchymal rim of the vortex. The elongated rows of isolated granules appear which subsequently, by confluence, form the myofibrillae. These cytoplasmic derivatives are elongated in the direction of the circumference of the vortex. 7. Between the epithelial tube and the myoblastic rim at the periphery of the mesenchymal whorl is found the embryonic connective tissue. From this direct observation the conclusion is made that an optimum tensional stress stimulus is necessary to elicit the formation of muscular tissue at the circumference of the mesenchymal vortex. Consequently, the formation of a specific derivative from a pluripotent mesenchymal cell is due to the fortuitous circumstance of position. 8. In embryos from 14 to 24 mm. in length, the esophagus grows relatively more rapidly in length than in width. This elongation is due to two factors; first, the descent of the stomach, and, second, the resistance to diametrical growth presented by the inner close spiral musculature. The epithelial tube, still the dominant zone of mitotic activity, pursues the lines of least resistance, and consequently growth in length takes place. This is due to the shifting of the planes of cell division on account of the compression of the inner, close spiral, muscle coat. 9. The undifferentiated mesenchyme peripherad to the inner, close spiral musculature is elongated and the histogenetic changes in muscular formation are gradually taking place between 14 and 24 mm. A very attenuated, outer, elongated, spiral, or longitudinal muscle coat is detected in the esophagus of a 24 mm. pig embryo. 10. The characteristic intestino-colic flexure is a torsional reaction of the mesenchyme. The mesenchymal cells are thrown into a left-handed helicoidal series, corresponding to the activity in the epithelial tube. The right-handed helicoidal reaction of the mesenchyme, therefore, is due to the left-handed helicoidal growth of the epithelial tube. 11. The normal asymmetry of the abdominal viscera as well as the position of the gut is dependent upon the clockwise reaction of the stretched mesenchymal cell. These cells are stretched by the left-handed helicoidal growth of the epithelial tube. One factor producing situs inversus viscerum could be the reversal of the spiral growth of the epithelial tube resulting in a reaction of the mesenchyme in a direction opposite, namely counterclockwise, to that which occurs normally. PMID- 19871850 TI - ION SERIES AND THE PHYSICAL PROPERTIES OF PROTEINS. I. AB - 1. This paper contains experiments on the influence of acids and alkalies on the osmotic pressure of solutions of crystalline egg albumin and of gelatin, and on the viscosity of solutions of gelatin. 2. It was found in all cases that there is no difference in the effects of HCl, HBr, HNO(3), acetic, mono-, di-, and trichloracetic, succinic, tartaric, citric, and phosphoric acids upon these physical properties when the solutions of the protein with these different acids have the same pH and the same concentration of originally isoelectric protein. 3. It was possible to show that in all the protein-acid salts named the anion in combination with the protein is monovalent. 4. The strong dibasic acid H(2)SO(4) forms protein-acid salts with a divalent anion SO(4) and the solutions of protein sulfate have an osmotic pressure and a viscosity of only half or less than that of a protein chloride solution of the same pH and the same concentration of originally isoelectric protein. Oxalic acid behaves essentially like a weak dibasic acid though it seems that a small part of the acid combines with the protein in the form of divalent anions. 5. It was found that the osmotic pressure and viscosity of solutions of Li, Na, K, and NH(4) salts of a protein are the same at the same pH and the same concentration of originally isoelectric protein. 6. Ca(OH)(2) and Ba(OH)(2) form salts with proteins in which the cation is divalent and the osmotic pressure and viscosity of solutions of these two metal proteinates are only one-half or less than half of that of Na proteinate of the same pH and the same concentration of originally isoelectric gelatin. 7. These results exclude the possibility of expressing the effect of different acids and alkalies on the osmotic pressure of solutions of gelatin and egg albumin and on the viscosity of solutions of gelatin in the form of ion series. The different results of former workers were probably chiefly due to the fact that the effects of acids and alkalies on these proteins were compared for the same quantity of acid and alkali instead of for the same pH. PMID- 19871851 TI - THE RECOVERY OF TRANSMISSIVITY IN PASSIVE IRON WIRES AS A MODEL OF RECOVERY PROCESSES IN IRRITABLE LIVING SYSTEMS : PART II. AB - 1. Passive iron (steel) wires, when activated after prolonged immersion in nitric acid of 55 to 90 per cent concentration (volumes per cent of HNO(3), specific gravity 1.42) revert spontaneously to the passive state, after a temporary reaction which is transmitted rapidly over the whole length of wire. The duration of this reaction at any region decreases rapidly with increase in the concentration above a certain critical limit of 52 to 54 per cent. In weaker acid (50 per cent and lower) the reaction continues uninterruptedly until all the metal is dissolved. 2. Immediately after this automatic repassivation the wire fails to transmit activation through more than a short distance (1 to 2 cm.); if left undisturbed in the acid it recovers by degrees its power of transmission (as measured by the distance traveled by an activation wave), at first slowly, then more rapidly; eventually, after an interval varying with the concentration of acid and the temperature, the activation wave is transmitted through an indefinite distance as before. 3. The return of complete transmissivity in 55 per cent acid occupies less than a minute (at 20 degrees ); in stronger acid it is more gradual, requiring in 90 per cent acid 20 minutes or more. This "complete recovery time" is nearly proportional to the excess of concentration of acid above the limiting value of 53 to 54 per cent. 4. In a given solution of acid the rate of recovery exhibits a temperature coefficient closely similar to that of most chemical reactions at this temperature (3-20 degrees ), and also to that of the rate of recovery (refractory period) of irritable living tissues after stimulation (Q(10) = about 3). 5. Two definite phases are distinguishable in the recovery process: (1) the redeposition of the continuous passivating surface layer (of oxide or oxygen compound); and (2) the progressive change of the newly passivated wire from the state of incomplete to that of complete transmissivity. The former phase is of brief duration and is indicated by a sudden change in the electrical potential of the wire, from that of active to that of passive iron; this phase is succeeded by the second and more prolonged period during which the passivating layer undergoes the progressive alteration associated with the recovery of transmissivity. This alteration appears to consist in a progressive thinning of the passivating film until a minimal thickness of (probably 1 molecule) is attained. Further thinning is prevented by local electrochemical oxidation. 6. The phenomena of partial or limited transmission during the second phase of the recovery process show a close correspondence with the phenomena of conduction with decrement in irritable living tissues such as nerve. Other analogies with the behavior of irritable tissues (threshold phenomena, distinction between "local" and "propagated" effects, summation, effects resembling electrotonus) are described. PMID- 19871852 TI - A THEORY OF INJURY AND RECOVERY : I. EXPERIMENTS WITH PURE SALTS. AB - 1. Laminaria exposed for a short period to 0.52 M NaCl loses a part of its electrical resistance but recovers it completely when replaced in sea water. When the period is lengthened recovery is incomplete. If the exposure is sufficiently prolonged no recovery occurs. (After exposure to 0.278 M CaCl(2) the resistance falls when the tissue is replaced in sea water.) 2. Equations are developed which enable us to predict the resistance of the tissue during exposure to NaCl or CaCl(2) as well as the recovery curves after any length of exposure to either of these solutions. PMID- 19871853 TI - LABYRINTH AND EQUILIBRIUM : III. THE MECHANISM OF THE STATIC FUNCTIONS OF THE LABYRINTH. PMID- 19871854 TI - THE ACTION OF INHIBITORY NERVES ON CARBON DIOXIDE PRODUCTION IN THE HEART GANGLION OF LIMULUS. AB - It has been shown in this paper that stimulation of the inhibitory nerves of the neurogenic heart of Limulus, which correspond to the vagus nerves of the vertebrate heart, results in a marked diminution of CO(2) production in the heart ganglion, while stimulation of the ganglion, leading to increased activity of the heart, leads also to increased CO(2) production by the ganglion. This shows that inhibition of the automaticity of this ganglion by the action of its inhibitory nerves consists, not in a process of blocking, but in a diminution of those chemical reactions in the ganglion cells which give rise to the production of CO(2). PMID- 19871855 TI - THE KINETICS OF INACTIVATION OF COMPLEMENT BY LIGHT. AB - The photoinactivation of complement has been studied with a view to determining if possible how many kinds of molecules disappeared during the reaction. It was found that: 1. The apparent course of photoinactivation is that of a monomolecular reaction. 2. Diffusion is not the limiting factor responsible for this fact, because the temperature coefficient of diffusion is much higher than that of photoinactivation (Q(10) = 1.22 to 1.28, and Q(10) = 1.10 respectively). 3. There is no change in the transparency of serum solutions during photoinactivation, at least for light of the effective wave-length, which is in the ultra-violet region probably at about 2530 Angstrom units. It is pointed out that under these conditions only one interpretation is possible; namely, that during photoinactivation a single disappearing molecular species governs the rate of reaction. This substance must be primarily responsible for the hemolytic power of serum when it is used as complement. PMID- 19871856 TI - THE MECHANISM OF COMPLEMENT ACTION. AB - IT HAS BEEN SHOWN: 1. That complement exposed to ultra-violet light is not thereby sensitized to the action of heat (which indicates that it is not protein). 2. That inactivation of complement by ultra-violet light is accompanied by a decrease in its surface tension. 3. That photoinactivation of complement is not a result of any changes in hydrogen ion concentration since these are less than 0.05 pH. 4. That hydrogen ion concentrations high enough to transform serum proteins from the cation to the anion condition (i.e. past the isoelectric point) permanently inactivate complement. These facts together with those given in previous papers lead to the following hypotheses. 1. That there is present in serum a hemolytic substance which is formed from a precursor (which may resemble lecithin) and is constantly being formed and simultaneously being broken down into inactive products. 2. That both precursor and lysin contain the same photosensitive molecular group. 3. That the lytic substance is dependent for its activity upon the state of the serum proteins. PMID- 19871857 TI - COMPARATIVE STUDIES ON RESPIRATION : XIII. AN APPARATUS FOR MEASURING THE PRODUCTION OF MINUTE QUANTITIES OF CARBON DIOXIDE BY ORGANISMS. PMID- 19871858 TI - ENVIRONMENTAL FACTORS OTHER THAN TEMPERATURE AFFECTING FACET NUMBER IN THE BAR EYED MUTANT OF DROSOPHILA. PMID- 19871859 TI - THE SIGNIFICANCE OF THE HYDROGEN ION CONCENTRATION FOR THE DIGESTION OF PROTEINS BY PEPSIN. AB - The experiments described above show that the rate of digestion and the conductivity of protein solutions are very closely parallel. If the isoelectric point of a protein is at a lower hydrogen ion concentration than that of another, the conductivity and also the rate of digestion of the first protein extends further to the alkaline side. The optimum hydrogen ion concentration for the rate of digestion and the degree of ionization (conductivity) of gelatin solutions is the same, and the curves for the ionization and rate of digestion as plotted against the pH are nearly parallel throughout. The addition of a salt with the same anion as the acid to a solution of protein already containing the optimum amount of the acid has the same depressing effect on the digestion as has the addition of the equivalent amount of acid. These facts are in quantitative agreement with the hypothesis that the determining factor in the digestion of proteins by pepsin is the amount of ionized protein present in the solution. It was shown in a previous paper that this would also account for the peculiar relation between the rate of digestion and the concentration of protein. The amount of ionized protein in the solution depends on the amount of salt formed between the protein (a weak base) and the acid. This quantity, in turn, according to the hydrolysis theory of the salts of weak bases and strong acids, is a function of the hydrogen ion concentration, up to the point at which all the protein is combined with the acid as a salt. This point is the optimum hydrogen ion concentration for digestion, since the solution now contains the maximum concentration of protein ions. The hydrogen ion concentration in this range therefore is merely a convenient indicator of the amount of ionized protein present in the solution and takes no active part in the hydrolysis. After sufficient acid has been added to combine with all the protein, i.e. at pH of about 2.0, the further addition of acid serves to depress the ionization of the protein salt by increasing the concentration of the common anion. The hydrogen ion concentration is, therefore, no longer an indicator of the amount of ionized protein present, since this quantity is now determined by the anion concentration. Hence on the acid side of the optimum the addition of the same concentration of anion should have the same influence on the rate of digestion irrespective of whether it is combined with hydrogen or some other ion (provided, of course, that there is no other secondary effect of the other ion). The proposed mechanism is very similar to that suggested by Stieglitz and his coworkers for the hydrolysis of the imido esters. Pekelharing and Ringer have shown that pure pepsin in acid solution is always negatively charged; i.e., it is an anion. The experiments described above show further that it behaves just as would be expected of any anion in the presence of a salt containing the protein ion as the cation and as has been shown by Loeb to be the case with inorganic anions. Nothing has been said in regard to the quantitative agreement between the increasing amounts of ionized protein found in the solution (as shown by the conductivity values) and the amount predicted by the hydrolysis theory of the formation of salts of weak bases and strong acids. There is little doubt that the values are in qualitative agreement with such a theory. In order to make a quantitative comparison, however, it would be necessary to know the ionization constant of the protein and of the protein salt and also the number of hydroxyl (or amino) groups in the protein molecule as well as the molecular weight of the protein. Since these values are not known with any degree of certainty there appears to be no value at present in attempting to apply the hydrolysis equations to the data obtained. It it clear that the hypothesis as outlined above for the hydrolysis of proteins by pepsin cannot be extended directly to enzymes in general, since in many cases the substrate is not known to exist in an ionized condition at all. It is possible, however, that ionization is really present or that the equilibrium instead of being ionic is between two tautomeric forms of the substrate, only one of which is attacked by the enzyme. Furthermore, it is clear that even in the case of proteins there are difficulties in the way since the pepsin obtained from young animals, or a similar enzyme preparation from yeast or other microorganisms, is said to have a different optimum hydrogen ion concentration than that found for the pepsin used in these experiments. The activity of these enzyme preparations therefore would not be found to depend on the ionization of the protein. It is possible of course that the enzyme preparations mentioned may contain several proteolytic enzymes and that the action observed is a combination of the action of several enzymes. Dernby has shown that this is a very probable explanation of the action of the autolytic enzymes. The optimum hydrogen ion concentration for the activity of the pepsin used in these experiments agrees very closely with that found by Ringer for pepsin prepared by him directly from gastric juice and very carefully purified. Ringer's pepsin probably represents as pure an enzyme preparation as it is possible to prepare. There is every reason to suppose therefore that the enzyme used in this work was not a mixture of several enzymes. PMID- 19871860 TI - RADIOACTIVITY AND PHYSIOLOGICAL ACTION OF POTASSIUM. AB - 1. The non-radioactive cesium ion can replace the potassium ion almost quantitatively in solutions required for the development of the egg of the sea urchin into swimming blastulae. 2. Thorium chloride and uranium acetate cannot replace the potassium chloride in the solutions required for the development of the egg. 3. Thorium chloride and uranium acetate do not antagonize the action of the potassium contained in sea water upon the development of eggs. PMID- 19871861 TI - CHEMICAL CHARACTER AND PHYSIOLOGICAL ACTION OF THE POTASSIUM ION. AB - 1. It is shown that the NH(4) ion acts in cases of antagonism on the egg of Fundulus more like the K ion than the Na ion; this corresponds to the fact that in its general chemical behavior the NH(4) ion resembles the K ion more closely than the Na ion. 2. It is shown that the tolerance of sea urchin eggs towards the Li ion can be increased 500 per cent or more if at the same time a certain amount of Na ion is replaced by K, Rb, or Cs ions. Since in the periodic table Na occupies a position between K and Li it is inferred that the Li and K ions deviate in their physiological action in the opposite direction from the Na ion. 3. These data indicate that the behavior of the K ion in antagonistic salt action (which forms the basis of the physiologically balanced action of ions) is due to its purely chemical character, i.e. its position in the periodic table or rather to its atomic number, and not to those explosions in its nucleus which give rise to a trace of radioactivity. PMID- 19871862 TI - ION SERIES AND THE PHYSICAL PROPERTIES OF PROTEINS. II. AB - 1. Our results show clearly that the Hofmeister series is not the correct expression of the relative effect of ions on the swelling of gelatin, and that it is not true that chlorides, bromides, and nitrates have "hydrating," and acetates, tartrates, citrates, and phosphates "dehydrating," effects. If the pH of the gelatin is taken into considertion, it is found that for the same pH the effect on swelling is the same for gelatin chloride, nitrate, trichloracetate, tartrate, succinate, oxalate, citrate, and phosphate, while the swelling is considerably less for gelatin sulfate. This is exactly what we should expect on the basis of the combining ratios of the corresponding acids with gelatin since the weak dibasic and tribasic acids combine with gelatin in molecular proportions while the strong dibasic acid H(2)SO(4) combines with gelatin in equivalent proportions. In the case of the weak dibasic acids he anion in combination with gelatin is therefore monovalent and in the case of the strong H(2)SO(4) it is bivalent. Hence it is only the valency and not the nature of the ion in combination with gelatin which affects the degree of swelling. 2. This is corroborated in the experiments with alkalies which show that LiOH, NaOH, KOH, and NH(4)OH cause the same degree of swelling at the same pH of the gelatin solution and that this swelling is considerably higher than that caused by Ca(OH)(2) and Ba(OH)(2) for the same pH. This agrees with the results of the titration experiments which prove that Ca(OH)(2) and Ba(OH)(2) combine with gelatin in equivalent proportions and that hence the cation in combination with the gelatin salt with these two latter bases is bivalent. 3. The fact that proteins combine with acids and alkalies on the basis of the forces of primary valency is therefore not only in full agreement with the influence of ions on the physical properties of proteins but allows us to predict this influence qualitatively and quantitatively. 4. What has been stated in regard to the influence of ions on the swelling of the different gelatin salts is also true in regard to the influence of ions on the relative solubility of gelatin in alcohol water mixtures. 5. Conductivity measurements of solutions of gelatin salts do not support the theory that the drop in the curves for swelling, osmotic pressure, or viscosity, which occurs at a pH 3.3 or a little less, is due to a drop in the concentration of ionized protein in the solution; nor do they suggest that the difference between the physical properties of gelatin sulfate and gelatin chloride is due to differences in the degree of ionization of these two salts. PMID- 19871863 TI - NUMERICAL LAW OF REGRESSION OF CERTAIN SECONDARY SEX CHARACTERS. AB - The discrepancy in the relative variation of C and of theta led us to examine more closely the velocity of regression at the beginning in all the cases. At a given point of the curve, the velocity is furnished by the differential quotient of the length with reference to the time: See PDF for Equation At the beginning of regression, that is to say, at the time 0 See PDF for Equation We have tabulated the corresponding numerical values in the various instances: See PDF for Structure Although there is not absolute equality among the figures of the last column, one cannot fail to be struck by the fact that there is very little difference; in all instances they diverge much less than those of the first two columns, in which the variation is from 0.5 to 4.75 and from 1.95 to 12.0. We must admit, therefore, within rather wide limits, the constancy of the product of the time of regression and the constant C, whether the castration is intrapuberal or post-puberal. Geometrically, this result is represented by the constancy of the angle of the ordinate and the tangent to the parabola at the point of departure of the regression curve. Furthermore, it follows that the numerical law is represented not only by a parabola, but more exactly by segments of homothetic parabolas-an unexpected generalization, which gives a remarkable unity to the law with which it is concerned. PMID- 19871864 TI - PHOTOCHEMISTRY OF VISUAL PURPLE : II. THE EFFECT OF TEMPERATURE ON THE BLEACHING OF VISUAL PURPLE BY LIGHT. AB - The temperature coefficient of the bleaching of visual purple by light is 1.00 over a range of 30 degrees. This indicates that the monomolecular course of the reaction represents a real chemical process, as opposed to a possible diffusion process, and that the reaction is probably simple in nature. PMID- 19871865 TI - THE AMPHOTERIC PROPERTIES OF SOME AMINO-ACIDS AND PEPTIDES. AB - The titration curves of solutions of glycine, alanine, alpha-ammo-butyric acid, leucine, glycyl-glycine, alanyl-glycine, alanyl-alanine, acetone, acetamide, urea, acetic acid, and aceturic acid were determined and some of the relations as dependent upon the chemical structures discussed. The isoelectric points of some of the amphoteric electrolytes were found experimentally. The definition of isoelectric point, its theoretical significance, and method of calculation were considered in some detail. PMID- 19871866 TI - THE ISOELECTRIC POINT OF RED BLOOD CELLS AND ITS RELATION TO AGGLUTINATION. AB - 1. The movement of normal and sensitized red blood cells in the electric field is a function of the hydrogen ion concentration. The isoelectric point, at which no movement occurs, corresponds with pH 4.6. 2. On the alkaline side of the isoelectric point the charge carried is negative and increases with the alkalinity. On the acid side the charge is positive and increases with the acidity. 3. On the alkaline side at least the charge carried by sensitized cells is smaller and increases less rapidly with the alkalinity than the charge of normal cells. 4. Both normal and sensitized cells combine chemically with inorganic ions, and the isoelectric point is a turning point for this chemical behavior. On the acid side the cells combine with the hydrogen and chlorine ions, and in much larger amount than on the alkaline side; on the alkaline side the cells combine with a cation (Ba), and in larger amount than on the acid side. This behavior corresponds with that found by Loeb for gelatin. 5. The optimum for agglutination of normal cells is at pH 4.75, so that at this point the cells exist most nearly pure, or least combined with anion and cation. 6. The optimum for agglutination of sensitized cells is at pH 5.3. This point is probably connected with the optimum for flocculation of the immune serum body. PMID- 19871867 TI - THE PRODUCTION OF VOLATILE FATTY ACIDS BY BACTERIA OF THE DYSENTERY GROUP. AB - THESE STUDIES SHOW: 1. A close agreement exists among all the organisms studied in the total quantity of volatile fatty acids produced and in the ratio of formic to acetic, under aerobic conditions, and in the presence of 1 per cent of glucose. 2. When grown upon peptone alone, with free access of air to the cultures, volatile fatty acids are produced in appreciable quantities, although the reaction of the solution has gone more alkaline as shown by colorimetric pH tests. Formic acid is not found, but in its place we obtain propionic acid. 3. Upon exhaustion of air from the non-sugar medium the bacteria again produce formic acid, and in addition some butyric. This is true for both Shiga and non Shiga cultures. The reaction is distinctly more acid. 4. The presence of glucose in the medium from which the air has been pumped furnishes a condition which provokes about the same type and degree of fermentation that operates in the glucose medium bathed in air at atmospheric pressure. 5. The enormous quantity of formic acid produced by these bacteria may play a significant part in the digestive disturbances and toxic symptoms accompanying their infection of the human intestinal tract. PMID- 19871868 TI - THE RESPONSE OF POPILLIA JAPONICA TO LIGHT AND THE WEBER-FECHNER LAW. AB - Light and a temperature above 23 degrees C. are necessary for the activity of Popillia. The effect of light as indicated by the rate of locomotor response is related to light intensity according to Fechner's expression of Weber's law. PMID- 19871869 TI - COMPARATIVE STUDIES ON RESPIRATION : XIV. ANTAGONISTIC ACTION OF LANTHANUM AS RELATED TO RESPIRATION. AB - 1. Concentrations of La(NO(3))(3) up to 0.000025 M have little effect upon the rate of respiration of Bacillus subtilis; at 0.000006 M there is an increase in rate, while in higher concentrations there is a decrease in rate. 2. There is well marked antagonism between La(NO(3))(3) and NaCl, and very slight antagonism between La(NO(3))(3) and CaCl(2). 3. It requires a very small amount of La(NO(3))(3) to antagonize NaCl, the proportions of the two salts at their maximum antagonism being 99.8 parts of NaCl and 0.2 parts of La(NO(3))(3). PMID- 19871870 TI - ON THE DIFFERENTIATION OF THE LEAF TISSUE FLUIDS OF LIGNEOUS AND HERBACEOUS PLANTS WITH RESPECT TO OSMOTIC CONCENTRATION AND ELECTRICAL CONDUCTIVITY. PMID- 19871871 TI - EXPERIMENTAL PRODUCTION OF GIGANTISM BY FEEDING THE ANTERIOR LOBE OF THE HYPOPHYSIS. AB - 1. Metamorphosed salamanders of the species Ambystoma opacum and Ambystoma tigrinum were fed on a pure diet of the anterior lobe of the hypophysis of cattle; the controls were fed on an abundant diet of earthworms. 2. The rate of growth of the animals fed on the anterior lobe of the hypophysis was greatly increased over the rate of growth of normal animals. 3. Growth of the animals fed on anterior lobe did not cease after they had reached the normal "maximum" size of the species, and experimental giants were produced. 4. The largest animal of the species Ambystoma opacum fed on anterior lobe of the hypophysis was 19 mm. larger than the largest normal animal of this species known to the writer; the largest animal of the species Ambystoma tigrinum fed on anterior lobe is at present about 28 mm. larger than the largest normal animal of the eastern race of this species known to the writer. PMID- 19871872 TI - TIME AND INTENSITY IN PHOTOSENSORY STIMULATION. AB - In its photosensory effect, the action of light depends on two variables, intensity and time. If the intensity alone is varied, the photochemical effect is proportional to the logarithm of the intensity. If the time alone is varied, the effect is proportional to the time. Experiments here reported show that when both the intensity and the time are varied, the photochemical effect is equal to the product of their separate activities: E = kt log I. These results furnish the means of expressing directly the relation between the intensity of illumination and the reaction time of Mya. PMID- 19871873 TI - THE RELATION BETWEEN THE WAVE-LENGTH OF LIGHT AND ITS EFFECT ON THE PHOTOSENSORY PROCESS. AB - 1. Following the description of a simple method of securing high intensities of monochromatic illumination, it is shown that the most effective portion of the spectrum for the stimulation of Mya is near lambda = 500 micromicro. 2. The quantitative data secured is interpreted in terms of certain photochemical findings, and as a result the absorption spectrum of the photosensitive substance of Mya is tentatively mapped out. PMID- 19871874 TI - ION SERIES AND THE PHYSICAL PROPERTIES OF PROTEINS : III. THE ACTION OF SALTS IN LOW CONCENTRATION. AB - 1. Ions with the opposite sign of charge as that of a protein ion diminish the swelling, osmotic pressure, and viscosity of the protein. Ions with the same sign of charge as the protein ion (with the exception of H and OH ions) seem to have no effect on these properties as long as the concentrations of electrolytes used are not too high. 2. The relative depressing effect of different ions on the physical properties of proteins is a function only of the valency and sign of charge of the ion, ions of the same sign of charge and the same valency having practically the same depressing effect on gelatin solutions of the same pH while the depressing effect increases rapidly with an increase in the valency of the ion. 3. The Hofmeister series of ions are the result of an error due to the failure to notice the influence of the addition of a salt upon the hydrogen ion concentration of the protein solution. As a consequence of this failure, effects caused by a variation in the hydrogen ion concentration of the solution were erroneously attributed to differences in the nature of the ions of the salts used. 4. It is not safe to draw conclusions concerning specific effects of ions on the swelling, osmotic pressure, or viscosity of gelatin when the concentration of electrolytes in the solution exceeds M/16, since at that concentration the values of these properties are near the minimum characteristic of the isoelectric point. PMID- 19871875 TI - A THEORY OF INJURY AND RECOVERY : II. EXPERIMENTS WITH MIXTURES. AB - 1. The equations which serve to predict the injury of tissue in 0.52 M NaCl and in 0.278 M CaCl(2) and its subsequent recovery (when it is replaced in sea water) also enable us to predict the behavior of tissue in mixtures of these solutions, as well as its recovery in sea water after exposure to mixtures. 2. The reactions which are assumed in order to account for the behavior of the tissue proceed as if they were inhibited by a salt compound formed by the union of NaCl and CaCl(2) with some constituent of the protoplasm (certain of these reactions are accelerated by CaCl(2)). 3. In this and preceding papers a quantitative theory is developed in order to explain: (a) the toxicity of NaCl and CaCl(2); (b) the antagonism between these substances; (c) the fact that recovery (in sea water) may be partial or complete, depending on the length of exposure to the toxic solution. PMID- 19871876 TI - THE RATE OF OVULATION IN THE DOMESTIC FOWL DURING THE PULLET YEAR. AB - The rate of ovulation of the domestic fowl may be expressed by the equation of an autocatalytic chemical reaction. This is not surprising in view of the fact that the rate of growth may also be expressed by such an equation, and that the rate of ovulation is probably an index of the growth of the eggs. This brings the phenomenon of ovulation in the hen under the general subject of growth, and substantiates the generality and the probability of the hypothesis that growth, or at any rate the limiting factor of growth, is an autocatalytic reaction. PMID- 19871877 TI - THE PHAGOCYTOSIS OF SOLID PARTICLES : I. QUARTZ. AB - 1. A new quantitative method of measuring phagocytosis of solid particles is described. 2. A method of calculating the chances of collision between leucocytes and quartz particles of different sizes is developed. 3. The speed with which three suspensions of different sized quartz particles should be ingested by leucocytes is predicted from the calculated chances of collision, and the prediction is verified experimentally. 4. The formula for the chances of collision is also verified by varying the speed of rotation of the tubes in which the phagocytic mixtures are incubated. PMID- 19871879 TI - AN INVESTIGATION INTO THE CAUSE OF THE SPONTANEOUS AGGREGATION OF FLAGELLATES AND INTO THE REACTIONS OF FLAGELLATES TO DISSOLVED OXYGEN : PART I. PMID- 19871878 TI - THE PHAGOCYTOSIS OF SOLID PARTICLES : II. CARBON. AB - 1. By measurements of the diameter and velocity of leucocytes and of the particles in two carbon suspensions, the relative rates of ingestion of the two suspensions by the leucocytes are predicted and the predictions verified experimentally. 2. The results indicate that 4.7micro particles of carbon are ingested as readily as 3.2micro particles. The more rapid apparent rate of ingestion of the 4.7micro particles is due to their greater availability rather than the greater capability of the leucocytes. 3. There is almost no phagocytosis of carbon in absence of serum or in heated serum. 4. The clumping of unwashed leucocytes is accllerated by serum and by the ingestion of carbon. 5. The available evidence indicates that the phagocytosis of bacteria does not follow the law for a monomolecular reaction, possibly because of the toxic effect upon the leucocytes of bacterial extracts. PMID- 19871880 TI - AN INVESTIGATION INTO THE CAUSE OF THE SPONTANEOUS AGGREGATION OF FLAGELLATES AND INTO THE REACTIONS OF FLAGELLATES TO DISSOLVED OXYGEN : PART II. AB - Spontaneous aggregations of flagellates are formed under the cover-glass because the organisms are attracted to and remain in regions where the concentration of dissolved oxygen is less than the saturation concentration under atmospheric partial pressure. These regions of lessened oxygen content arise towards the center of the liquid beneath the cover-glass, owing to the oxygen consumed by the flagellates in respiration not being replaced here by the solution of atmospheric oxygen, as it is along the edges of the liquid. The flagellates, however, are insensitive to the attraction of regions of lessened oxygen concentration when the oxygen concentration throughout the liquid is above a certain value. Therefore, for the aggregations to form, either the initial concentration of dissolved oxygen must be below this limiting value, or an interval of time must first elapse after the making of the preparation until the respiration of the organisms has reduced the oxygen concentration throughout the liquid down to this limiting value. The aggregations will then form because the flagellates have become positively chemotropic to the lower concentration of oxygen at the center of the liquid. Once established, such an aggregation of flagellates does not remain long in the same form. An area free from flagellates appears at the center of the aggregation so that the organisms lie in a circular band surrounding the clear area. The latter increases in size and its bordering band of flagellates in diameter, the band gradually becoming less circular and more square in shape, if the cover-glass is a square one. The clear central area is a region where the oxygen consumption of the flagellates has reduced the oxygen content to such a low value that the organisms are forced to leave the region. They collect in a band where the concentration of dissolved oxygen is an optimum for them. It is the equilibrium position between the oxygen consumed at the center and that diffusing in from the edges of the liquid. As the consumption at the center is more rapid than the replacement from the edge, the flagellate band moves outwards until it becomes stationary at a position where the rates of consumption and replacement of oxygen are equal. Although the flagellates collect in this manner in regions of optimum oxygen concentration, yet greater concentrations of dissolved oxygen have no injurious effect on them. Concentrations of dissolved oxygen lower than the optimum have the effect of inhibiting the movement of the flagellates. They recover their activity, however, immediately they are given access to dissolved oxygen again. Work done in the past on chemotropism of flagellates will have to be revised in the light of the above facts, since the oxygen content of solutions used has never been taken into account. PMID- 19871881 TI - THE EQUILIBRIUM BETWEEN HEMOLYTIC SENSITIZER AND RED BLOOD CELLS IN RELATION TO THE HYDROGEN ION CONCENTRATION. AB - 1. In a salt-free medium the proportion of the total amount of hemolytic sensitizer present, combined with the homologous cells, reaches a maximum of almost 100 per cent at pH 5.3. On the alkaline side of this point the proportion combined diminishes with the alkalinity and reaches a minimum of approximately 5 per cent at pH 10. On the acid side of pH 5.3 the proportion combined diminishes with the acidity but somewhat less rapidly than for a corresponding increase in alkalinity. 2. The presence of NaCl greatly increases the proportion of sensitizer combined with cells at all reactions except those in the neighborhood of pH 5.3. At this point the combination of sensitizer with cells is independent of the presence of electrolyte. 3. The curves representing the proportion of sensitizer combined or free run almost exactly parallel, both when the sensitizer combines de novo and when it dissociates from combination; therefore, in constant volume, at a given hydrogen ion concentration, and at a given temperature, an equilibrium exists between the amount of sensitizer free and that combined with cells. 4. The combination of sensitizer and cells is related fundamentally to the isoelectric point of the sensitizer. 5. The dissociated ions of the sensitizer, formed either by its acid or its basic dissociation, do not unite with cells. Combination takes place only between the cells and the undissociated molecules of the sensitizer. PMID- 19871882 TI - SUMMATION OF DISSIMILAR STIMULI APPLIED TO LEAFLETS OF SENSITIVE BRIER (SCHRANKIA). AB - 1. The pinnae of sensitive brier or Schrankia are favorable for demonstrating summation of dissimilar stimuli. 2. The demonstration was made as follows: A time of day was chosen when the closure of a single proximal leaflet did not provoke closure of the next distal leaflet. An irritating gas was applied to the pinna. A few seconds later, a single leaflet was touched; it closed, induced closure of the next distal leaflet, and inaugurated a wave of closure which proceeded until all leaflets on the same side of the mid-rib were closed. PMID- 19871883 TI - COMPARATIVE STUDIES ON RESPIRATION : XV. THE EFFECT OF BILE SALTS AND OF SAPONIN UPON RESPIRATION. AB - 1. The addition of Na taurocholate produces an increase in the rate of respiration at a concentration of 0.0000125 M, and a decrease at 0.001 M and in higher concentrations. 2. NaCl is antagonized by Na taurocholate, the most favorable proportion being 14,375 parts of NaCl to 1 part of Na taurocholate (molecular proportions). 3. Solutions of saponin, at concentrations from 0.00005 M to 0.001 M, decrease the rate of respiration: lower concentrations produce no effect. PMID- 19871884 TI - COMPARATIVE STUDIES ON RESPIRATION : XVI. EFFECTS OF HYPOTONIC AND HYPERTONIC SOLUTIONS UPON RESPIRATION. AB - 1. In highly hypertonic solutions of sea water the rate of respiration of Laminaria agardhii is rapidly reduced. 2. In highly hypotonic solutions the rate of respiration of Laminaria agardhii is reduced somewhat less rapidly than in the case of hypertonic solutions. 3. Hypertonic solutions of NaCl, CaCl(2), and of mixtures of NaCl, and CaCl(2) in the proportion of 50:1, all caused a decrease in the rate of respiration of wheat seedlings. PMID- 19871885 TI - FURTHER OBSERVATIONS ON THE PRODUCTION OF PARTHENOGENETIC FROGS. PMID- 19871886 TI - CHEMICAL AND PHYSICAL BEHAVIOR OF CASEIN SOLUTIONS. AB - The experiments on casein solutions therefore confirm the conclusion at which we arrived from the behavior of gelatin and crystalline egg albumin that the forces determining the combination between proteins and acids or alkalies are the same forces of primary valency which also determine the reaction between acids and alkalies with crystalloids, and that the valency and not the nature of the ion in combination with a protein determines the effect on the physical properties of the protein. PMID- 19871887 TI - THE COLLOIDAL BEHAVIOR OF PROTEINS. AB - 1. It is well known that neutral salts depress the osmotic pressure, swelling, and viscosity of protein-acid salts. Measurements of the P.D. between gelatin chloride solutions contained in a collodion bag and an outside aqueous solution show that the salt depresses the P.D. in the same proportion as it depresses the osmotic pressure of the gelatin chloride solution. 2. Measurements of the hydrogen ion concentration inside the gelatin chloride solution and in the outside aqueous solution show that the difference in pH of the two solutions allows us to calculate the P.D. quantitatively on the basis of the Nernst formula See PDF for Equation if we assume that the P.D. is due to a difference in the hydrogen ion concentration on the two sides of the membrane. 3. This difference in pH inside minus pH outside solution seems to be the consequence of the Donnan membrane equilibrium, which only supposes that one of the ions in solution cannot diffuse through the membrane. It is immaterial for this equilibrium whether the non-diffusible ion is a crystalloid or a colloid. 4. When acid is added to isoelectric gelatin the osmotic pressure rises at first with increasing hydrogen ion concentration, reaches a maximum at pH 3.5, and then falls again with further fall of the pH. It is shown that the P.D. of the gelatin chloride solution shows the same variation with the pH (except that it reaches its maximum at pH of about 3.9) and that the P.D. can be calculated from the difference of pH inside minus pH outside on the basis of Nernst's formula. 5. It was found in preceding papers that the osmotic pressure of gelatin sulfate solutions is only about one-half of that of gelatin chloride or gelatin phosphate solutions of the same pH and the same concentration of originally isoelectric gelatin; and that the osmotic pressure of gelatin oxalate solutions is almost but not quite the same as that of the gelatin chloride solutions of the same pH and concentration of originally isoelectric gelatin. It was found that the curves for the values for P.D. of these four gelatin salts are parallel to the curves of their osmotic pressure and that the values for pH inside minus pH outside multiplied by 58 give approximately the millivolts of these P.D. In this preliminary note only the influence of the concentration of the hydrogen ions on the P.D. has been taken into consideration. In the fuller paper, which is to follow, the possible influence of the concentration of the anions on this quantity will have to be discussed. PMID- 19871888 TI - METHODS OF STUDYING THE RESPIRATORY EXCHANGE IN SMALL AQUATIC ORGANISMS, WITH PARTICULAR REFERENCE TO THE USE OF FLAGELLATES AS AN INDICATOR FOR OXYGEN CONSUMPTION. AB - 1. Flagellates are positively chemotactic to a certain concentration of dissolved oxygen which is lower than that in water saturated with oxygen under atmospheric partial pressure. Consequently, when a small aquatic animal is held motionless between cover-slip and slide in a suspension of flagellates in water saturated with oxygen, the flagellates are attracted to those parts of the animal which are absorbing oxygen. The relative sizes of the flagellate aggregations then show the relative activities of the different surfaces of the animal in absorbing oxygen. 2. Applying this method to the red Chironomus larva it was found that the animal respires by the whole body surface except by the head and the "ventral gills" and that the relative intensity of oxygen intake by the different parts of the body varies in different individuals and in the same individual at different times. 3. The absence of oxygen intake by the "ventral gills" was confirmed with the microspectroscope. In oxygen-free water all the hemoglobin of the blood becomes reduced. When an air bubble is now introduced so that it touches the "ventral gills" oxyhemoglobin first appears in the nearest body segment to the bubble, not in the "gills." 4. When a small aquatic animal is held motionless between cover slip and slide in a solution of an indicator which changes color about the neutral point of water the relative extent of color change at different surfaces of the animal's body indicates the relative amounts of carbon dioxide given off by these surfaces. 5. Using this method with the red Chironomus larva similar conclusions were reached for carbon dioxide output as for oxygen intake. PMID- 19871889 TI - THE PHAGOCYTOSIS OF SOLID PARTICLES : III. CARBON AND QUARTZ. AB - 1. The rates of ingestion of quartz and carbon particles by leucocytes, when both are in suspension in serum, was compared with the availability of the two particles as predicted from the calculated chances of collision with the leucocytes, and it was shown that carbon is ingested about 4 times as readily as quartz. 2. The greater ease of ingestion of carbon was verified by a new method of measuring phagocytosis, described as the film method in which the cells ingest particles as they creep about on a slide. 3. The relative rates of ingestion of carbon and quartz depend upon the condition of the cells, the difference increasing as the phagocytic activity of the cells decreases. 4. Sponge cells also ingest carbon about 3 times as readily as quartz. 5. The hypothesis is suggested that the cause of the more rapid ingestion of carbon may be identical with the cause of the greater instability of the carbon suspensions. 6. An inorganic analogy to this selective phagocytic action is offered. 7. The application to opsonins and agglutinins is discussed. PMID- 19871890 TI - STUDIES ON ENZYME ACTION : XIX. THE SUCROLYTIC ACTIONS OF BANANAS. AB - A number of different methods of treatment of unripe and ripe bananas for the purpose of obtaining and studying sucrolytic and amylolytic enzymes are described. No conclusive evidence of the presence of an amlyase could be obtained in any of the preparations. The sucrase of unripe and ripe bananas was studied more extensively. With ripe bananas, both soluble and insoluble sucrase preparations were obtained. Conditions for converting the soluble into an insoluble form were found. The actions of the sucrase preparations as far as the hydrogen ion concentration for maximum action and the time-action relation are concerned are similar to the behavior of the yeast and the potato sucrase. PMID- 19871891 TI - A THEORY OF INJURY AND RECOVERY : III. REPEATED EXPOSURES TO TOXIC SOLUTIONS. AB - Tissues of Laminaria transferred from sea water to solutions of pure salts, and thence to other solutions of pure salts, or to sea water, behave in a manner which can be predicted by means of the equations previously developed. The behavior of the tissue may be explained as due to a series of catenary reactions. It is possible that a similar explanation may be applied to other fundamental life processes. PMID- 19871892 TI - THE RATE OF GROWTH OF THE DAIRY COW : EXTRAUTERINE GROWTH IN WEIGHT. AB - The growth period of the Jersey and Holstein cows is made up of at least three cycles, two extrauterine cycles with maxima at about 5 and 20 months of age, and one intrauterine cycle, the maximum of which has not yet been determined. The equation of an autocatalytic monomolecular reaction was found to give very good results when applied to the cycle having its maximum at about 5 months of age. The values obtained from this equation when applied to the cycle having the maximum at about 20 months of age were higher than the observed values probably due to the retarding effect of pregnancy and lactation on growth. PMID- 19871893 TI - CASEIN VISCOSITY STUDIES. AB - 1. Viscosity and pH curves of casein dissolved in NaOH, KOH, LiOH, and NH(4)OH are shown and it is found that a maximum viscosity occurs at about the same pH point with each alkali; i.e., 9.1 to 9.25. The magnitude of the viscosity is largest in ammonia solutions. 2. The maximum viscosity occurs in 8 to 10 per cent solutions of casein in alkalies when about 98 x 10(-5) gram equivalents of base are combined with 1 gram of casein. 3. A maximum viscosity occurs in the same region (pH 9.1 to 9.25) when casein is dissolved in Na(2)CO(3), Na(3)AsO(4), Na(2)SO(3), NaF, and Na(2)PO(3). 4. The maximum viscosity obtained with borax solutions of casein occurs at 8.15 to 8.2 pH. It is suggested that casein acts like mannitol, glycerol, etc., in increasing the dissociation of boric acid. 5. The flattening of the viscosity curves of casein solutions, following the decline from maximum, is shown to be due to alkaline hydrolysis whence casein no longer exists as such but is cleaved into a major protein containing no phosphorus or sulfur and less nitrogen. This cleavage commences at pH 10.0 to 10.5. 6. When casein is prepared from solutions that have been subjected to high temperatures (60 degrees C. and above) or has otherwise been heated during its preparation, it yields solutions in alkalies of high viscosity. PMID- 19871894 TI - THE SIGNIFICANCE OF LATENCY TIME IN ENZYME DETERMINATION. PMID- 19871896 TI - THE PHYSIOLOGICAL ZERO: AN EXPLANATION OF THE DEPARTURE FROM THE LINEAR GRAPH OF REACTION RATE VALUES AT THE LOWER TEMPERATURES. PMID- 19871895 TI - ASSOCIATIVE BACTERIAL ACTION IN THE PROPIONIC ACID FERMENTATION. PMID- 19871897 TI - COMPARATIVE STUDIES ON RESPIRATION : XVII. DECREASED RESPIRATION AND RECOVERY. PMID- 19871898 TI - DONNAN EQUILIBRIUM AND THE PHYSICAL PROPERTIES OF PROTEINS : I. MEMBRANE POTENTIALS. AB - 1. It is shown that a neutral salt depresses the potential difference which exists at the point of equilibrium between a gelatin chloride solution contained in a collodion bag and an outside aqueous solution (without gelatin). The depressing effect of a neutral salt on the P.D. is similar to the depression of the osmotic pressure of the gelatin chloride solution by the same salt. 2. It is shown that this depression of the P.D. by the salt can be calculated with a fair degree of accuracy on the basis of Nernst's logarithmic formula on the assumption that the P.D. which exists at the point of equilibrium is due to the difference of the hydrogen ion concentration on the opposite sides of the membrane. 3. Since this difference of hydrogen ion concentration on both sides of the membrane is due to Donnan's membrane equilibrium this latter equilibrium must be the cause of the P.D. 4. A definite P.D. exists also between a solid block of gelatin chloride and the surrounding aqueous solution at the point of equilibrium and this P.D. is depressed in a similar way as the swelling of the gelatin chloride by the addition of neutral salts. It is shown that the P.D. can be calculated from the difference in the hydrogen ion concentration inside and outside the block of gelatin at equilibrium. 5. The influence of the hydrogen ion concentration on the P.D. of a gelatin chloride solution is similar to that of the hydrogen ion concentration on the osmotic pressure, swelling, and viscosity of gelatin solutions, and the same is true for the influence of the valency of the anion with which the gelatin is in combination. It is shown that in all these cases the P.D. which exists at equilibrium can be calculated with a fair degree of accuracy from the difference of the pH inside and outside the gelatin solution on the basis of Nernst's logarithmic formula by assuming that the difference in the concentration of hydrogen ions on both sides of the membrane determines the P.D. 6. The P.D. which exists at the boundary of a gelatin chloride solution and water at the point of equilibrium can also be calculated with a fair degree of accuracy by Nernst's logarithmic formula from the value pCl outside minus pCl inside. This proves that the equation x(2) = y ( y + z) is the correct expression for the Donnan membrane equilibrium when solutions of protein-acid salts with monovalent anion are separated by a collodion membrane from water. In this equation x is the concentration of the H ion (and the monovalent anion) in the water, y the concentration of the H ion and the monovalent anion of the free acid in the gelatin solution, and z the concentration of the anion in combination with the protein. 7. The similarity between the variation of P.D. and the variation of the osmotic pressure, swelling, and viscosity of gelatin, and the fact that the Donnan equilibrium determines the variation in P.D. raise the question whether or not the variations of the osmotic pressure, swelling, and viscosity are also determined by the Donnan equilibrium. PMID- 19871899 TI - DONNAN EQUILIBRIUM AND THE PHYSICAL PROPERTIES OF PROTEINS : II. OSMOTIC PRESSURE. AB - 1. It had been shown in previous publications that the osmotic pressure of a 1 per cent solution of a protein-acid salt varies in a characteristic way with the hydrogen ion concentration of the solution, the osmotic pressure having a minimum at the isoelectric point, rising steeply with a decrease in pH until a maximum is reached at pH of 3.4 or 3.5 (in the case of gelatin and crystalline egg albumin), this maximum being followed by a steep drop in the osmotic pressure with a further decrease in the pH of the gelatin or albumin solution. In this paper it is shown that (aside from two minor discrepancies) we can calculate this effect of the pH on the osmotic pressure of a protein-acid salt by assuming that the pH effect is due to that unequal distribution of crystalloidal ions (in particular free acid) on both sides of the membrane which Donnan's theory of membrane equilibrium demands. 2. It had been shown in preceding papers that only the valency but not the nature of the ion (aside from its valency) with which a protein is in combination has any effect upon the osmotic pressure of the solution of the protein; and that the osmotic pressure of a gelatin-acid salt with a monovalent anion (e.g. Cl, NO(3), acetate, H(2)PO(4), HC(2)O(4), etc.) is about twice or perhaps a trifle more than twice as high as the osmotic pressure of gelatin sulfate where the anion is bivalent; assuming that the pH and gelatin concentrations of all the solutions are the same. It is shown in this paper that we can calculate with a fair degree of accuracy this valency effect on the assumption that it is due to the influence of the valency of the anion of a gelatin-acid salt on that relative distribution of the free acid on both sides of the membrane which Donnan's theory of membrane equilibrium demands. 3. The curves of the observed values of the osmotic pressure show two constant minor deviations from the curves of the calculated osmotic pressure. One of these deviations consists in the fact that the values of the ascending branch of the calculated curves are lower than the corresponding values in the curves for the observed osmotic pressure, and the other deviation consists in the fact that the drop in the curves of calculated values occurs at a lower pH than the drop in the curves of the observed values. PMID- 19871900 TI - THE ROLE OF THE ACTIVITY COEFFICIENT OF THE HYDROGEN ION IN THE HYDROLYSIS OF GELATIN. AB - 1. The hydrolysis of gelatin at a constant hydrogen ion concentration follows the course of a monomolecular reaction for about one-third of the reaction. 2. If the hydrogen ion concentration is not kept constant the amount of hydrolysis in certain ranges of acidity is proportional to the square root of the time (Schutz's rule). 3. The velocity of hydrolysis in strongly acid solution (pH less than 2.0) is directly proportional to the hydrogen ion concentration as determined by the hydrogen electrode i.e., the "activity;" it is not proportional to the hydrogen ion concentration as determined by the conductivity ratio. 4. The addition of neutral salts increases the velocity of hydrolysis and the hydrogen ion concentration (as determined by the hydrogen electrode) to approximately the same extent. 5. The velocity in strongly alkaline solutions (pH greater than 10) is directly proportional to the hydroxyl ion concentration. 6. Between pH 2.0 and pH 10.0 the rate of hydrolysis is approximately constant and very much greater than would be calculated from the hydrogen and hydroxyl ion concentration. This may be roughly accounted for by the assumption that the uncombined gelatin hydrolyzes much more rapidly than the gelatin salt. PMID- 19871901 TI - ENERGY AND VISION. AB - A method was devised for measuring the minimum visibile in different parts of the spectrum, as done by Langley in 1888. The results are generally in good agreement with those given by this author, although not as close on both sides of the wave length 0.55 micro; this may be due partly to the use of a rock salt prism, to the fact that the minimum was determined by looking at a beam of diffused transmitted, instead of diffused reflected light, and also to the fact that Langley experimented with the sun, through the earth's atmosphere, and had to take into account the thickness of the atmosphere interposed and the brightness of the sky. Although his experiments were made with great care, the differences from one day to another are important. However, when he expresses the energy in absolute units, he always refers to the same mean amount of energy radiated by the sun on 1 sq. cm. This amount is certainly not constant, if one judges from the differences observed in two measurements of sensitivity of the eye of the same individual at different dates. On the contrary, for a given wave length, our measurements always agreed closely, as our source of radiation was very nearly constant, owing to the absence of a varying amount of water vapor interposed. This may in some way account for the discrepancies observed. PMID- 19871902 TI - THE RATE OF GROWTH OF THE DOMESTIC FOWL. AB - This paper points out the fact that the growth period of the domestic fowl is analogous to that of the mammal, being composed of three, or perhaps four, cycles; two of these cycles are postembryonic with maxima at about 8 and 18 weeks varying somewhat with the breed and two or at least one, are embryonic with maxima at 11 to 12 and 15 to 16 days of age. Hatching occurs during the first part of the second or third cycle resembling in this respect the guinea pig rather than the mouse. The velocity curves of each of these cycles are similar to and can be represented by the equation of an autocatalytic monomolecular reaction. PMID- 19871903 TI - THE THERMOLABILITY OF COMPLEMENT, IN RELATION TO THE HYDROGEN ION CONCENTRATION. AB - 1. The destruction which complement undergoes on being heated in dilution in distilled water is least at a reaction between pH 6.1 and 6.4. This depends upon the relative preservation of the midpiece function at this point. This reaction represents probably the isoelectric point of a compound of the euglobulin with some substance present also in serum. 2. During the process of thermoinactivation it is chiefly or entirely the ions of this euglobulin compound which react, and these combine or interact with substances contained in the pseudoglobulin and albumin fraction. 3. The behavior of the euglobulin is different in the anionic and in the cationic condition, since on the acid side of pH 6.1 to 6.4 the destruction by heat increases as rapidly with the acidity in the presence as in the absence of NaCl. On the alkaline side of this point the presence of NaCl protects complement from destruction because of the depression in the ionization of the euglobulin. PMID- 19871904 TI - A SIMPLE CASE OF SALT ANTAGONISM IN STARFISH EGGS. AB - The jelly surrounding the eggs of the starfish, Asterias forbesi, is insoluble in normal sea water, but rapidly swells and dissolves when the eggs are washed in a pure isotonic solution of NaCl. In the presence of a small proportion of CaCl(2) this solvent and disintegrative action of the NaCl solution is entirely prevented, and in the mixed solution the jelly exhibits the same insolubility and other properties as in normal sea water. 2. This action of CaCl(2) in preventing the dissolution of the jelly runs parallel with its action in preventing certain definite effects of the pure NaCl solution on the living egg (agglutination, cytolytic action, membrane formation, prevention of maturation). 3. The inference is that the essential factor in these and similar antagonistic and protective actions is the formation of solid water-insoluble colloidal salts (e.g., soaps and proteinates) of calcium (or other metal) with the structural colloids of the protoplasm. Apparently the presence of a certain proportion of such compounds is necessary to the structural stability of the living protoplasm, and especially to the water-insolubility and semipermeability of its external layer or plasma membrane. When the cell is immersed in the pure NaCl solution, water-soluble Na compounds are substituted for the insoluble Ca compounds which normally provide the necessary insolubility and coherence, and disintegration results. PMID- 19871905 TI - STUDIES IN WOOD DECAY : II. ENZYME ACTION IN POLYPORUS VOLVATUS PECK AND FOMES IGNIARIUS (L.) GILLET. AB - Circumstantial evidence is presented which indicates that Polyporus volvatus is parasitic. Cultures of Polyporus volvatus and Fomes igniarius may be obtained from the young sporophores by the tissue method. In Polyporus volvatus the presence of the following enzymes was demonstrated: esterase, maltase, lactase, sucrase, raffinase, diastase, inulase, cellulase, hemicellulase, glucosidase, rennet, and catalase. In Fomes igniarius the presence of the following enzymes was demonstrated: esterase, maltase, lactase, sucrase, raffinase, diastase, inulase, cellulase, hemicellulase, glucosidase, urease, rennet, and catalase. PMID- 19871906 TI - STUDIES ON THE REGULATION OF OSMOTIC PRESSURE : I. THE EFFECT OF INCREASING CONCENTRATIONS OF GELATIN ON THE CONDUCTIVITY OF A SODIUM CHLORIDE SOLUTION. AB - 1. In pure gelatin solutions the conductivity of the solution increases with increasing concentrations, regardless of the hydrogen ion concentration. The actual value of the specific conductivity is greater at that reaction where the degree of ionization is greater. 2. The addition of gelatin in increasing concentrations to a 0.6 per cent sodium chloride solution affects the conductivity of that solution in two ways: (a) At pH 3.3, (where gelatin is highly ionized) the conductivity increases with each added increment of gelatin. (b) At pH 5.1 and 7.4 (where gelatin is less highly ionized) the conductivity decreases with each added increment of gelatin. A similar study is being made of crystalline egg albumin. PMID- 19871907 TI - CORRELATION OF THE PROPAGATION-VELOCITY OF THE CONTRACTION-WAVE IN MUSCLE WITH THE ELECTRICAL CONDUCTIVITY OF THE SURROUNDING MEDIUM. PMID- 19871908 TI - DONNAN EQUILIBRIUM AND THE PHYSICAL PROPERTIES OF PROTEINS : III. VISCOSITY. AB - 1. Gelatin solutions have a high viscosity which in the case of freshly prepared solutions varies under the influence of the hydrogen ion concentration in a similar way as the swelling, the osmotic pressure, and the electromotive forces. Solutions of crystalline egg albumin have under the same conditions a comparatively low viscosity which is practically independent of the pH (above 1.0). This difference in the viscosities of solutions of the two proteins seems to be connected with the fact that solutions of gelatin have a tendency to set to a Jelly while solutions of crystalline egg albumin show no such tendency at low temperature and pH above 1.0. 2. The formulae for viscosity demand that the difference in the order of magnitude of the viscosity of the two proteins should correspond to a difference in the relative volume occupied by equal masses of the two proteins in the same volume of solution. It is generally assumed that these variations of volume of dissolved proteins are due to the hydration of the isolated protein ions, but if this view were correct the influence of pH on viscosity should be the same in the case of solutions of gelatin, of amino-acids, and of crystalline egg albumin, which, however, is not true. 3. Suspensions of powdered gelatin in water were prepared and it was found, first, that the viscosity of these suspensions is a little higher than that of gelatin solutions of the same concentration, second, that the pH influences the viscosity of these suspensions similarly as the viscosity of freshly prepared gelatin solutions, and third, that the volume occupied by the gelatin in the suspension varies similarly as the viscosity which agrees with the theories of viscosity. It is shown that this influence of the pH on the volume occupied by the gelatin granules in suspension is due to the existence of a Donnan equilibrium between the granules and the surrounding solution. PMID- 19871909 TI - CONDUCTIVITY AND PERMEABILITY. AB - An electrical current passing through a living plant flows partly through the cell wall and partly through the protoplasm. The relative amounts of these two portions of the current can be calculated. The outcome of such calculations shows that the conclusions drawn from the study of the resistance of the tissue as a whole apply also to the resistance of the protoplasm, and consequently to the permeability of the protoplasm to ions. PMID- 19871910 TI - STEREOTROPIC REACTIONS OF THE SHOVEL-NOSED RAY, RHINOBATUS PRODUCTUS. PMID- 19871911 TI - THE STEREOTROPISM OF THE DOGFISH (MUSTELUS CALIFORNICUS) AND ITS REVERSAL THROUGH CHANGE OF INTENSITY OF THE STIMULUS. AB - 1. The dogfish responds to certain contact stimuli by definite stereotropic reactions. These reactions can be positive or negative. 2. The sense of the stereotropic response depends on the strength of the stimulus; a "weak" stimulus, produces a positive and a "strong" stimulus, a negative response. 3. The strength of stimulus necessary to cause a reversal of the reaction depends in part on the physiological state of the animal. 4. The stereotropic reactions occur equally well in the absence of the forebrain. PMID- 19871912 TI - CHEMICAL STIMULATION OF THE NERVE CORD OF LUMBRICUS TERRESTRIS. PMID- 19871913 TI - THE FORMATION OF THE ASTER IN ARTIFICIAL PARTHENOGENESIS. PMID- 19871914 TI - STUDIES ON THE ORGANIZATION OF THE STARFISH EGG. PMID- 19871915 TI - THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS : I. CONDITIONS CONTROLLING ABSORPTION AND RETENTION OF POTASSIUM. AB - 1. Individual variations in the potassium content of the fresh muscles of frogs are notable even when computed as percentages of the dry solids. The potassium content averaged higher in freshly collected summer frogs than in winter frogs after a period of captivity. 2. Muscles show a loss of from 8 to 15 per cent of their potassium during perfusion with potassium-free Ringer solution but tenaciously hold the remainder. 3. Muscles, stimulated to contract under conditions that do not produce irreversible stages of fatigue, show losses of potassium no greater than those attributable to the presence of a potassium-free medium. 4. A condition favorable to the taking up of potassium probably occurs in a contracting muscle because rubidium and cesium, substances very similar to potassium in chemical and physiological behavior, are absorbed in retainable form by a contracting muscle but not by a resting one. PMID- 19871916 TI - COMPARATIVE HYDROLYSIS OF GELATIN BY PEPSIN, TRYPSIN, ACID, AND ALKALI. AB - A comparison has been made of the relative velocity of hydrolysis of the various peptid linkings of the gelatin molecule when hydrolyzed by acid, alkali, pepsin or trypsin. It has been found that: 1. Those linkages which are most rapidly split by pepsin or trypsin are among the more resistant to acid hydrolysis. 2. Those linkages which are hydrolyzed by pepsin are also hydrolyzed by trypsin. 3. Trypsin hydrolyzes linkages which are not attacked by pepsin. 4. Of the linkages which are hydrolyzed by both enzymes, those which are most rapidly hydrolyzed by pepsin are only slowly attacked by trypsin. 5. Those linkages which are attacked by trypsin or pepsin are among the ones first (most rapidly) hydrolyzed by alkali. In general it may be said that the course of the early stages of hydrolysis of gelatin is similar with alkali, trypsin, or pepsin and quite different with acid. PMID- 19871917 TI - DONNAN EQUILIBRIUM AND THE PHYSICAL PROPERTIES OF PROTEINS : IV. VISCOSITY Continued. AB - 1. The proof is completed that the influence of electrolytes on the viscosity of suspensions of powdered particles of gelatin in water is similar to the influence of electrolytes on the viscosity of solutions of gelatin in water. 2. It has been suggested that the high viscosity of proteins is due to the existence of a different type of viscosity from that existing in crystalloids. It is shown that such an assumption is unnecessary and that the high viscosity of solutions of isoelectric gelatin can be accounted for quantitatively on the assumption that the relative volume of the gelatin in solution is comparatively high. 3. Since isoelectric gelatin is not ionized, the large volume cannot be due to a hydration of gelatin ions. It is suggested that this high volume of gelatin solutions is caused by the existence in the gelatin solution of submicroscopic pieces of solid gelatin occluding water, the relative quantity of which is regulated by the Donnan equilibrium. This would also explain why the influence of electrolytes on the viscosity of gelatin solutions is similar to the influence of electrolytes on the viscosity of suspensions of particles of gelatin. 4. This idea is supported by experiments on solutions and suspensions of casein chloride in which it is shown that their viscosity is chiefly due to the swelling of solid particles of casein, occluding quantities of water regulated by the Donnan equilibrium; and that the breaking up of these solid particles into smaller particles, no longer capable of swelling, diminishes the viscosity. 5. This leads to the idea that proteins form true solutions in water which in certain cases, however, contain, side by side with isolated ions and molecules, submicroscopic solid particles capable of occluding water whereby the relative volume and the viscosity of the solution is considerably increased. This accounts not only for the high order of magnitude of the viscosity of such protein solutions but also for the fact that the viscosity is influenced by electrolytes in a similar way as is the swelling of protein particles. 6. We therefore reach the conclusion that there are two sources for the viscosity of protein solutions; one due to the isolated protein ions and molecules, and the other to the submicroscopic solid particles contained in the solution. The viscosity due to the isolated molecules and ions of proteins we will call the general viscosity since it is of a similar low order of magnitude as that of crystalloids in solution; while the high viscosity due to the submicroscopic solid protein particles capable of occluding water and of swelling we will call the special viscosity of protein solutions. Under ordinary conditions of hydrogen ion concentration and temperature (and in not too high a concentration of the protein in solution) the general viscosity due to isolated ions and molecules prevails in solutions of crystalline egg albumin and in solutions of metal caseinates (where the metal is monovalent) while under the same conditions the second type of viscosity prevails in solutions of gelatin and in solutions of acid-salts of casein; and also in solutions of crystalline egg albumin at a pH below 1.0 and at higher temperatures. The special viscosity is higher in solutions of gelatin than of casein salts for the probable reason that the amount of water occluded by the submicroscopic solid gel particles in a gelatin solution is, as a rule, considerably higher than that occluded by the corresponding particles of casein. PMID- 19871918 TI - THE RECIPROCAL RELATION BETWEEN THE OSMOTIC PRESSURE AND THE VISCOSITY OF GELATIN SOLUTIONS. AB - 1. These experiments confirm the conclusion that protein solutions are true solutions consisting of isolated ions and molecules, and that these solutions may or may not contain in addition solid submicroscopic particles capable of occluding water. 2. The typical influence of electrolytes on the osmotic pressure of protein solutions is due to the isolated protein ions since these alone are capable of causing a Donnan equilibrium across a membrane impermeable to the protein ions but permeable to most crystalloidal ions. 3. The similar influence of electrolytes on the viscosity of protein solutions is due to the submicroscopic solid protein particles capable of occluding water since the amount of water occluded by (or the amount of swelling of) these particles is regulated by the Donnan equilibrium. 4. These ideas are supported by the fact that the more the submicroscopic solid particles contained in a protein solution or suspension are transformed into isolated ions (e.g., by keeping gelatin solution for 1 hour or more at 45 degrees C.) the more the viscosity of the solution is diminished while the osmotic pressure is increased, and vice versa. PMID- 19871919 TI - THE NATURE OF FOVEAL DARK ADAPTATION. AB - 1. After a discussion of the sources of error involved in the study of dark adaptation, an apparatus and a procedure are described which avoid these errors. The method includes a control of the initial light adaptation, a record of the exact beginning of dark adaptation, and an accurate means of measuring the threshold of the fovea after different intervals in the dark. 2. The results show that dark adaptation of the eye as measured by foveal vision proceeds at a very precipitous rate during the first few seconds, that most of the adaptation takes place during the first 30 seconds, and that the process practically ceases after 10 minutes. These findings explain much of the irregularity of the older data. 3. The changes which correspond to those in the fovea alone are secured by correcting the above results in terms of the movements of the pupil during dark adaptation. 4. On the assumption that the photochemical effect of the light is a linear function of the intensity, it is shown that the dark adaptation of the fovea itself follows the course of a bimolecular reaction. This is interpreted to mean that there are two photolytic products in the fovea; that they are disappearing because they are recombining to form anew the photosensitive substance of the fovea; and that the concentration of these products of photolysis in the sense cell must be increased by a definite fraction in order to produce a visual effect. 5. It is then suggested that the basis of the initial event in foveal light perception is some mechanism that involves a reversible photochemical reaction of which the "dark" reaction is bimolecular. Dark adaptation follows the "dark" reaction; sensory equilibrium is represented by the stationary state; and light adaptation by the shifting of the stationary state to a fresh point of equilibrium toward the "dark" side of the reaction. PMID- 19871920 TI - THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS : II. THE CAUSE OF POTASSIUM SELECTION AS INDICATED BY THE ABSORPTION OF RUBIDIUM AND CESIUM. AB - 1. Frog muscles perfused with Ringer solution in which potassium chloride has been replaced by an equivalent amount of rubidium or cesium chloride take up rubidium or cesium and incorporate them into the tissue substance in such form as to be retained during a subsequent perfusion with potassium-free Ringer solution, provided the muscles contract during the first perfusion. Retention of rubidium or cesium by a resting muscle does not occur. 2. Rats on synthetic diets, adequate in all respects except that potassium was replaced by an equivalent amount of rubidium or cesium, died after a period varying from 10 to 17 days with characteristic symptoms including tetanic spasms. Muscle, heart, liver, kidney, spleen, and lung tissues were then found to contain significant amounts of rubidium or cesium. The concentration of these metals in the muscle amounted, in some cases, as shown by a spectroscopic estimation, to about half the concentration of potassium normally found in mammallian muscle. 3. The results are regarded as tending to confirm the theory that the peculiarities in the physiological effects of potassium, including the facility with which it is "selected" by living cells in preference to sodium, are related to the electronic structure of the potassium ion as compared with that of similar ions. The possible relationship of the comparative migration velocity, a function of the electronic structure, to physiological effects is suggested. PMID- 19871921 TI - THE RELATION OF RESPIRATION TO RHYTHM IN THE CARDIAC GANGLION OF LIMULUS POLYPHEMUS. PMID- 19871922 TI - COMPARATIVE STUDIES ON RESPIRATION : XIX. A PRELIMINARY STAGE IN THE PROGRESS OF ETHER ANESTHESIA. AB - Using these concentrations of ether (1 per cent, 3.65 per cent, 7.3 per cent), the following conclusions may be drawn. 1. The first effect of ether is to cause a depression in the rate of respiration. This is followed by a rapid rise above normal, which in turn is succeeded by a fall. 2. With all these concentrations the respiration is ultimately reduced to approximately the same level; the stronger the ether, the less time required to produce this result. 3. Even when the respiration has been reduced below normal, recovery is possible on removal from the ether, and appears to be complete, if sufficient time is allowed. If, however, the rate has been too far depressed, no recovery is possible. 4. These results extend those of Irwin on frog eggs and Fundulus embryos. PMID- 19871923 TI - STEREOTROPIC ORIENTATION OF THE TUBE FEET OF STARFISH (ASTERIAS) AND ITS INHIBITION BY LIGHT. PMID- 19871924 TI - COMPARATIVE STUDIES ON RESPIRATION : XX. THE CAUSE OF PARTIAL RECOVERY. AB - The respiration of Chlorella is diminished by exposure to hypertonic salt solutions. After a short exposure there is complete recovery when the algae are removed to the normal medium. After a longer exposure recovery may be incomplete, as shown by the fact that the rate of respiration fails to rise to the normal level. Staining with methylene blue indicates that few, if any, of the cells are killed as the result of the exposure. It would therefore seem that the treatment produces a persistent lowering of the rate of metabolism. Such a condition of metabolism is also found after exposure to chloroform. PMID- 19871925 TI - THE EFFECT OF HYDROGEN ION CONCENTRATION ON THE PRODUCTION OF CARBON DIOXIDE BY BACILLUS BUTYRICUS AND BACILLUS SUBTILIS. AB - 1. The maximum rate of CO(2) production of Bacillus butyricus was found to be at a pH value of 7; of Bacillus subtilis at pH 6.8. If the pH value be raised or lowered there is a progressive decrease in the rate of production of CO(2). 2. Spontaneous recovery follows the addition of alkali to either organism, while addition of acid is followed by recovery only upon addition of an equivalent amount of alkali, and is not complete except when the amount of acid is very small. PMID- 19871926 TI - THE INFLUENCE OF ELECTROLYTES ON THE SOLUTION AND PRECIPITATION OF CASEIN AND GELATIN. AB - 1. Colloids have been divided into two groups according to the ease with which their solutions or suspensions are precipitated by electrolytes. One group (hydrophilic colloids), e.g., solutions of gelatin or crystalline egg albumin in water, requires high concentrations of electrolytes for this purpose, while the other group (hydrophobic colloids) requires low concentrations. In the latter group the precipitating ion of the salt has the opposite sign of charge as the colloidal particle (Hardy's rule), while no such relation exists in the precipitation of colloids of the first group. 2. The influence of electrolytes on the solubility of solid Na caseinate, which belongs to the first group (hydrophilic colloids), and of solid casein chloride which belongs to the second group (hydrophobic colloids), was investigated and it was found that the forces determining the solution are entirely different in the two cases. The forces which cause the hydrophobic casein chloride to go into solution are forces regulated by the Donnan equilibrium; namely, the swelling of particles. As soon as the swelling of a solid particle of casein chloride exceeds a certain limit it is dissolved. The forces which cause the hydrophilic Na caseinate to go into solution are of a different character and may be those of residual valency. Swelling plays no role in this case, and the solubility of Na caseinate is not regulated by the Donnan equilibrium. 3. The stability of solutions of casein chloride (requiring low concentrations of electrolytes for precipitation) is due, first, to the osmotic pressure generated through the Donnan equilibrium between the casein ions tending to form an aggregate, whereby the protein ions of the nascent micellum are forced apart again; and second, to the potential difference between the surface of a micellum and the surrounding solution (also regulated by the Donnan equilibrium) which prevents the further coalescence of micella already formed. This latter consequence of the Donnan effect had already been suggested by J. A. Wilson. 4. The precipitation of this group of hydrophobic colloids by salts is due to the diminution or annihilation of the osmotic pressure and the P.D. just discussed. Since low concentrations of electrolytes suffice for the depression of the swelling and P.D. of the micella, it is clear why low concentrations of electrolytes suffice for the precipitation of hydrophobic colloids, such as casein chloride. 5. This also explains why only that ion of the precipitating salt is active in the precipitation of hydrophobic colloids which has the opposite sign of charge as the colloidal ion, since this is always the case in the Donnan effect. Hardy's rule is, therefore, at least in the precipitation of casein chloride, only a consequence of the Donnan effect. 6. For the salting out of hydrophilic colloids, like gelatin, from watery solution, sulfates are more efficient than chlorides regardless of the pH of the gelatin solution. Solution experiments lead to the result that while CaCl(2) or NaCl increase the solubility of isoelectric gelatin in water, and the more, the higher the concentration of the salt, Na(2)SO(4) increases the solubility of isoelectric gelatin in low concentrations, but when the concentration of Na(2)SO(4) exceeds M/32 it diminishes the solubility of isoelectric gelatin the more, the higher the concentration. The reason for this difference in the action of the two salts is not yet clear. 7. There is neither any necessity nor any room for the assumption that the precipitation of proteins is due to the adsorption of the ions of the precipitating salt by the colloid. PMID- 19871927 TI - THE ORIGIN OF THE POTENTIAL DIFFERENCES RESPONSIBLE FOR ANOMALOUS OSMOSIS. AB - 1. Collodion bags coated with gelatin on the inside were filled with a M/256 solution of neutral salt (e.g., NaCl, CaCl(2), CeCl(3), or Na(2)SO(4)) made up in various concentrations of HNO(3) (varying from N/50,000 to N/100). Each collodion bag was put into an HNO(3) solution of the same concentration as that inside the bag but containing no salt. In this case water diffuses from the outside solution (containing no salt) into the inside solution (containing the salt) with a relative initial velocity which can be expressed by the following rules: (a) Water diffuses into the salt solution as if the particles of water were negatively charged and as if they were attracted by the cation and repelled by the anion of the salt with a force increasing with the valency of the ion. (b) The initial rate of the diffusion of water is a minimum at the hydrogen ion concentration of about N/50,000 HCl (pH 4.7, which is the point at which gelatin is not ionized), rises with increasing hydrogen ion concentration until it reaches a maximum and then diminishes again with a further rise in the initial hydrogen ion concentration. 2. The potential differences between the salt solution and the outside solution (originally free from salt) were measured after the diffusion had been going on for 1 hour; and when these values were plotted as ordinates over the original pH as abscissae, the curves obtained were found to be similar to the osmotic rate curves. This confirms the view expressed by Girard) Bernstein, Bartell, and Freundlich that these cases of anomalous osmosis are in reality cases of electrical endosmose where the driving force is a P.D. between the opposite sides of the membrane. 3. The question arose as to the origin of these P. D. and it was found that the P.D. has apparently a double origin. Certain features of the P.D. curve, such as the rise and fall with varying pH, seem to be the consequence of a Donnan equilibrium which leads to some of the free HNO(3) being forced from the solution containing salt into the outside solution containing no (or less) salt. This difference of the concentration of HNO(3), on the opposite sides of the membrane leads to a P.D. which in conformity with Nernst's theory of concentration cells should be equal to 58 x (pH inside minus pH outside) millivolts at 18 degrees C. The curves of the values of (pH inside minus pH outside) when plotted as ordinates over the original pH as abscissae lead to curves resembling those for the P. D. in regard to location of minimum and maximum. 4. A second source of the P.D. seems to be diffusion potentials, which exist even if no membranes are present and which seem to be responsible for the fact that the rate of diffusion of negatively charged water into the salt solution increases with the valency of the cation and diminishes with the valency of the anion of the salt. 5. The experiments suggest the possibility that the establishment of a Donnan equilibrium between membrane and solution is one of the factors determining the Helmholtzian electrical double layer, at least in the conditions of our experiments. PMID- 19871928 TI - THE INACTIVATION OF TRYPSIN. I. PMID- 19871929 TI - THE INACTIVATION OF TRYPSIN : II. THE EQUILIBRIUM BETWEEN TRYPSIN AND THE INHIBITING SUBSTANCE FORMED BY ITS ACTION ON PROTEINS. AB - 1. A study has been made of the equilibrium existing between trypsin and the substances formed in the digestion of proteins which inhibit its action. 2. This substance could not be obtained by the hydrolysis of the proteins by acid or alkali. It is dialyzable. 3. The equilibrium between this substance (inhibitor) and trypsin is found to agree with the equation, trypsin + inhibitor right harpoon over left harpoon trypsin-inhibitor The equilibrium is reached instantaneously and is independent of the substrate concentration. If it be further assumed that the rate of hydrolysis is proportional to the concentration of the free trypsin and that the equilibrium conforms to the law of mass action, it is possible to calculate the experimental results by the application of the law of mass action. 4. The equilibrium has been studied by varying (a) the concentration of the inhibiting substance, (b) the concentration of trypsin, (c) the concentration of gelatin, and (d) the concentration of trypsin and inhibitor (the relative concentration of the two remaining the same). In all cases the results agree quantitatively with those predicted by the law of mass action. 5. It was found that the percentage retarding effect of the inhibiting substance on the rate of hydrolysis is independent of the hydrogen ion concentration between pH 6.3 and 10.0. 6. The fact that the experimental results agree with the mechanism outlined under 3, is contrary to the assumption that any appreciable amount of trypsin is combined with the gelatin at any one time; i.e., the velocity of the hydrolysis must depend on the time required for such a compound to form rather than for it to decompose. 7. The experiments may be considered as experimental proof of the validity of Arrhenius' explanation of Schutz's rule as applied to trypsin digestion. 8. Inactivated trypsin does not enter into the equilibrium. PMID- 19871930 TI - THE INACTIVATION OF TRYPSIN : III. SPONTANEOUS INACTIVATION. AB - 1. The rate of inactivation of purified trypsin solutions approximates closely that demanded by the monomolecular formula. The more carefully the solution is purified the closer the agreement with the formula. 2. The products formed by the action of trypsin on proteins renders the trypsin more stable. Gelatin and glycine have no effect. 3. The rate of inactivation of trypsin solutions containing these products does not follow the course of a monomolecular reaction but becomes progressively slower than the predicted rate. 4. The protective action of these substances is much greater if they are added all at once at the beginning of the experiment than if they are added at intervals. These observations may be quantitatively accounted for by the hypothesis that a compound is formed between trypsin and the inhibiting substance which is stable as well as inactive, and that the rate of decomposition depends on the amount of uncombined trypsin present. 5. Trypsin is most stable at a pH of 5 and is rapidly destroyed in strongly acid or alkaline solution. 6. The protective effect of the inhibiting substances is small on the acid side of pH 5, increases from pH 5 to 7, and then remains approximately constant. PMID- 19871931 TI - DIRECT AND INDIRECT DETERMINATIONS OF PERMEABILITY. AB - 1. Methods are described for obtaining cell sap from Nitella without contamination. 2. Tests of the cell sap show that in a balanced solution of NaNO(3) plus Ca(NO(3))(2) there is a slow penetration of NO(3) and that the cell remains in a normal condition, but in pure NaNO(3) there is rapid penetration accompanied by injury. 3. Inasmuch as determinations of electrical conductivity give the same result it may be concluded that this method gives reliable information regarding permeability. 4. While observations on recovery from plasmolysis give similar results, the method is less satisfactory. PMID- 19871933 TI - THE EFFECTS OF RADIUM RAYS ON METABOLISM AND GROWTH IN SEEDS. PMID- 19871932 TI - STUDIES ON BIOLUMINESCENCE : XIV. THE SPECIFICITY OF LUCIFERIN AND LUCIFERASE. AB - Among sixteen groups of luminous forms investigated by the author, in only four (fireflies, Pholas, ostracods, and Odontosyllis) is it possible to demonstrate the luciferin-luciferase reaction. In many groups this is probably due to the small amount of these substances present in the luminescent organism or to their instability. In the medusae and pennatulids, despite a large amount of luminescent material, luciferin and luciferase cannot be demonstrated. This does not appear to be due to the presence of luciferin and luciferase in equivalent proportion, or to their instability. In fact, one is led to the conclusion that luciferin and luciferase do not exist in these forms, but such a conclusion must be regarded as merely tentative, in view of the fundamental character of the luciferin-luciferase reaction. Luciferin of one form will not luminesce with the luciferase of another form or vice versa, unless very closely related (Cypridina and Pyrocypris). All experiments emphasize the specificity of the light producing substances of Cypridina. PMID- 19871934 TI - CORRESPONDENCE OF SKIN PIGMENTS IN RELATED SPECIES OF NUDIBRANCHS. PMID- 19871935 TI - THE PHYSIOLOGY OF THE RESPIRATION OF FISHES IN RELATION TO THE HYDROGEN ION CONCENTRATION OF THE MEDIUM. AB - 1. The ability of marine fishes to absorb oxygen at low tension from the sea water is more or less dependent upon the hydrogen ion concentration of the water. 2. The ability of fishes to withstand wide variations in the range of hydrogen ion concentration of the sea water can be correlated with their habitats. The fishes that are most resistant to a wide variation in the hydrogen ion concentration are most cosmopolitan in their habitat. Those that are least resistant to a variation in the hydrogen ion concentration are the most restricted in their range of habitat. 3. There is a close correlation between the optimum condition of the sea water for the absorption of oxygen at low tension by the herring (Clupea pallasii), the condition of the sea water to which they react positive and that in which they are found most abundantly. 4. It is suggested that the variation in the ability to absorb oxygen at low tension at a given pH of individuals of a species is dependent upon the alkaline reserve of the blood of the individual fish. PMID- 19871936 TI - THE EFFECT OF IODINE AND IODOTHYRIN ON THE LARVAE OF SALAMANDERS : IV. THE ROLE OF IODINE IN THE INHIBITION OF THE METAMORPHOSIS OF THYMUS-FED SALAMANDERS. PMID- 19871937 TI - THE INFLUENCE OF FEEDING THE ANTERIOR LOBE OF THE HYPOPHYSIS ON THE SIZE OF AMBYSTOMA TIGRINUM. AB - 1. Animals of the species Ambystoma tigrinum when fed anterior lobe can reach a size far in excess of that of animals fed earthworms and presumably also of that of liver-fed animals. 2. Liver produces a rate of growth as high as that resulting from anterior lobe-feeding, but maintains growth only, until the animals reach a definite size far below that of anterior lobe-fed animals. PMID- 19871938 TI - THE TEMPERATURE COEFFICIENT OF PHAGOCYTOSIS. AB - 1. The experiments of Madsen and Watabiki on the effect of temperature on the phagocytosis of bacteria are discussed and a new analysis of their curves is given, showing that the rate of phagocytosis is very nearly a logarithmic function of the temperature from 0 degrees to 35 degrees C.; i.e., Q(10) is constant over that range and is equal to 2.0. 2. New experiments are reported on the effect of temperature on the phagocytosis of quartz and carbon particles of uniform sizes, showing a marked increase in the temperature coefficient below 30 degrees C. PMID- 19871939 TI - THE PENETRATION OF CATIONS INTO LIVING CELLS. AB - Direct tests of the cell sap of Nitella show that the protoplasm is normally permeable to Li, Cs, and Sr, and that penetration is more rapid in an unbalanced than in a balanced solution. PMID- 19871940 TI - THE ORIGIN OF THE ELECTRICAL CHARGES OF COLLOIDAL PARTICLES AND OF LIVING TISSUES. AB - 1. When a solution of a salt of gelatin or crystalline egg albumin is separated by a collodion membrane from a watery solution (free from protein) a potential difference is set up across the membrane in which the protein is positively charged in the case of protein-acid salts and in which the protein is negatively charged in the case of metal proteinates. The turning point is the isoelectric point of the protein. 2. Measurements of the pH of the (inside) protein solution and of the outside watery solution show that when equilibrium is established the value pH inside minus pH outside is positive in the case of protein-acid salts and negative in the case of metal proteinates. This is to be expected when the P.D. is caused by the establishment of a Donnan equilibrium, since in that case the pH should be lower outside than inside in the case of a protein-acid salt and should be higher outside than inside in the case of a metal proteinate. 3. At the isoelectric point where the electrical charge is zero the value of pH inside minus pH outside becomes also zero. 4. It is shown that a P.D. is established between suspended particles of powdered gelatin and the surrounding watery solution and that the sign of charge of the particles is positive when they contain gelatin-acid salts, while it is negative when the powdered particles contain metal gelatinate. At the isoelectric point the charge is zero. 5. Measurements of the pH inside the powdered particles and of the pH in the outside watery solution show that when equilibrium is established the value pH inside minus pH outside is positive when the powdered particles contain a gelatin-acid salt, while the value pH inside minus pH outside is negative when the powdered particles contain Na gelatinate. At the isoelectric point the value pH inside minus pH outside is zero. 6. The addition of neutral salts depresses the electrical charge of the powdered particles of protein-acid salts. It is shown that the addition of salts to a suspension of powdered particles of gelatin chloride also diminishes the value of pH inside minus pH outside. 7. The agreement between the values 58 (pH inside minus pH outside) and the P. D. observed by the Compton electrometer is not only qualitative but quantitative. This proves that the difference in the concentration of acid (or alkali, as the case may be) in the two phases is the only cause for the observed P.D. 8. The Donnan theory demands that the P.D. of a gelatin chloride solution should be 1(1/2) times as great as the P.D. of a gelatin sulfate solution of the same pH and the same concentration (1 per cent) of originally isoelectric gelatin. This is found to be correct and it is also shown that the values of pH inside minus pH outside for the two solutions possess the ratio of 3:2. 9. All these measurements prove that the electrical charges of suspended particles of protein are determined exclusively by the Donnan equilibrium. PMID- 19871941 TI - THE THEORETICAL RESPONSE OF LIVING CELLS TO CONTACT WITH SOLID BODIES. AB - The theoretical behavior of a hypothetical fluid cell in contact with flat and curved solid surfaces is discussed from the point of view of surface tension. An equation is derived for calculating the equilibrium position of the cell on a flat surface in terms of the surface tensions between the cell and the plasma, the plasma and the solid surface, and the solid surface and the cell. It is shown that the same equilibrium is predicted from consideration of the contact angle between the cell and the solid body. The relative surface energy has been calculated at various stages in the ingestion of a solid particle by a fluid cell four times as large in diameter, and it is thus shown that no particle will be ingested until the surface tensions are such that the cell would spread to infinity on a flat surface of the same substance. Here again the same equilibrium is predicted from considerations of the contact angle. The adhesiveness of blood cells to solid substances is shown to be a pure surface tension phenomenon, but in most reactions between living cells and solid bodies the fluidity of the protoplasm is also a factor of prime importance. The frequent occurrence of adhesiveness as a property of cells in contact with solid bodies is due in part to the fact that, by so adhering, the surface area of the cell not touching the solid is decreased. PMID- 19871942 TI - CHANGE OF ACID AGGLUTINATION OPTIMUM AS INDEX OF BACTERIAL MUTATION. AB - A distinct difference in acid agglutination optimum for Type D (bacillus of rabbit septicemia) and its mutant form, Type G, has been observed. The optimum for Type D lies between pH 3.5 and pH 3.0. This changes during mutation, the resulting Type G mutants having in general an optimum lying between pH 4.7 and pH 3.8. The constancy of the optimum for Type D is very strict, while that for Type G is slightly less so. The variation is never so great as to cause an overlapping of optima and consequent failure of differentiation. These acid agglutination optima are in the nature of physical constants for the two types and would imply a fundamental difference in the chemical constitution of the organisms. Animal passage, far from causing a reversion of the mutant Type G to the primordial Type D form, brings about a still greater instability in the presence of H ions. PMID- 19871943 TI - THE MECHANISM OF GRANULAR GROWTH OF RABBIT SEPTICEMIA BACILLUS TYPE G. AB - The acid agglutination optimum of Microbes D and G is not independent of the nature of the buffer mixture. Glycocoll-HCl buffer mixtures cause complete flocculation at high C(H)+ (2.7 to 2.4), at which points little or no flocculation occurs with the Na lactate-lactic acid buffer series. Beef infusion has the property of broadening the acid agglutination optimum of both Microbes D and G, bacilli of rabbit septicemia. This extension is in the direction of a lower C(H)+. There is no evidence that the beef infusion has the power, per se, of agglutinating these organisms. It would seem merely to increase their sensitiveness to sedimentation in the presence of H ions. The data presented explain the mechanism of the granular growth character of Microbe G in liquid media as compared to the diffuse growth of Microbe D. Peptone (Fairchild), contrary to beef infusion, shifts the acid agglutination optimum of Microbes D and G in the direction of a higher C(H)+. Strong concentrations of peptone exhibit an inhibitory effect on the agglutination of Microbe D in the optimum zone. PMID- 19871944 TI - THE AGGLUTINATION OF RED BLOOD CELLS IN THE PRESENCE OF BLOOD SERA. AB - 1. The addition of blood serum displaces the optimum for agglutination of red blood cells in a salt-free medium to the reaction characteristic of flocculation of the serum euglobulin. 2. This effect is not due merely to a mechanical entanglement of the cells by the precipitating euglobulin, since at reactions at which the latter is soluble it protects the cells from the agglutination which occurs in its absence. 3. A combination of some sort appears therefore to take place between sheep cells and sheep, rabbit, and guinea pig serum euglobulin, and involves a condensation of the serum protein upon the surface of the red cell. 4. At the optimal point for agglutination of persensitized cells both mid- and end piece of complement combine with the cells. 5. Agglutination is closely related to an optimal H ion concentration in the suspending fluid, and probably of the cell membrane, and not to a definite reaction in the interior of the cell. PMID- 19871945 TI - THE RELATIVE TOXICITY OF THE HALIDES AND CERTAIN OTHER ANIONS. PMID- 19871946 TI - SOME EFFECTS OF RADIUM RADIATIONS ON WHITE MICE. AB - It has been estimated that 92 per cent of the total radiation emitted by radium in equilibrium with its subsequent products is given off in the form of alpha rays. This, however, cannot be utilized when the source is enclosed in an ordinary container, because the alpha-rays are absorbed completely by even a small thickness of glass. About 3.2 per cent of the total radiation is emitted in the form of beta-rays, and 4.8 per cent as gamma radiation. The effects produced on the radiated mice of these experiments were due mainly to the beta-rays, which are easily absorbed by tissue. The gamma-rays, being only slightly absorbed by organic matter, probably contributed very little to the observed effects. It is interesting to correlate the different effects produced by the same dose of radiation. The mice which received a dose of 1.9 millicurie hours showed no local effects on the skin or hair. Neither females nor males were sterilized, and the time at which they opened their eyes or reached sexual maturity was not affected, as far as we could tell. The only difference noted between the radiated animals and the controls was in the body weight. This dose accelerated the growth of the young mice, that is, while initially of the same weight, soon after irradiation they became distinctly bigger than the controls, but finally the animals of each group had substantially the same average weight. That this variation in body weight should be accidental is unlikely, since it was observed also in the animals treated by a slightly larger dose (2.4 millicurie hours). The number of animals (seven) which showed this effect is too small to prove conclusively the accelerating effect of small doses of radiation on the body growth of mice. But considering that similar results have been. obtained by radiating plants and beetles, it is reasonable that the observed increase in weight might be attributed, at least in part, to the effects of radiation. Since this paper was first written Russ, Chambers, and Scott have shown that small doses of x-rays accelerate the body growth of rats. In view of this additional evidence there can be little doubt that the increase in weight observed in our experiments was due to the radiation. A dose of 2.4 millicurie hours applied over the backs of the animals produced no local skin effects, but it accelerated the growth of the mice as in the previous case. In addition it caused permanent sterilization of all the females. A similar result was obtained with 4.9 millicurie hours, except that the effect on the rate of growth was uncertain. A dose of 6.8 millicurie hours produced a definite but mild skin erythema and retarded the development of lanugo hair. But since in this instance the emanation was applied over the heads of the animals, the dose reaching the ovaries was not sufficient to cause sterilization, as already explained. No other definite effect was noted. In connection with the sterilization of the females it should be noted that a dose of radiation which produced no visible skin changes was sufficient to cause permanent sterility. On account of the greater distance of the ovaries from the source of radiation as compared with that of the skin directly below the tube, and the depth of tissue which the rays had to traverse to reach the ovaries, the amount of radiation acting on the latter was much smaller than the amount falling on the skin. The radiation emitted by the emanation tube is reduced to about 50 per cent of its initial value after traversing 1 mm. of tissue. Still, while the skin was not visibly affected, the mice were sterilized. This shows that the ovaries are influenced very easily by radiation of this type. We can estimate the amount of radiation reaching the ovaries which is sufficient to cause sterility to be less than 25 per cent of the amount necessary to produce visible skin changes in the mice. It should be noted also that whenever sterility of the female mice was induced, it was permanent. Furthermore, those mice which were not rendered sterile by radiation were, as far as the experiments enable us to say, as prolific as the controls. Remembering that a dose of 1.9 millicurie hours had no apparent effect on the ovaries, while a slightly larger dose, 2.4 millicurie hours, caused permanent sterility, it might be concluded that it is not possible to produce temporary sterility by radiation. We know, however, that temporary sterility can be produced, at least when the animals are radiated at a later stage in their development. The mice in our experiments were radiated for the first time soon after birth, and it is not improbable that under these conditions temporary sterility cannot be obtained. Large sublethal doses produced severe skin burns, retarded the body growth of the animals, but failed to sterilize the males. About one-third of the total skin area of the mice showed marked effects from the radiation. The animals were very sick for a time, and their growth was temporarily stunted. But nevertheless they recovered and finally became apparently normal except for the narrow hairless strip of skin which had been closest to the emanation tube. Only the females were rendered permanently sterile. The males did not show even temporary sterility when the doses of radiation were close to the lethal dose. While the testes of mammals are known to be very easily affected by radiation, still they are more resistant than the ovaries. In addition, in these experiments they were at a greater distance from the source of radiation than the ovaries, and they were better protected by the thicker layer of tissue in the path of the rays. The fact that no sublethal dose in these experiments sterilized the males shows that under the conditions of irradiation adopted the amount of radiation reaching the testes was not sufficient to affect them noticeably. If the source of radiation had been applied closer to the reproductive organs of the males, they would have been sterilized by millicurie hour doses much smaller than the lethal dose. Some of the radiated animals were killed with ether, and macroscopic and microscopic examinations of the reproductive organs were made. The ovaries of the sterile females were generally atrophied and colored yellow. The normal histological structure was altered. The characteristic findings were the destruction of the Graafian follicles, with absence of ovum cells. The testes and the epididymis of the radiated mice of the present experiment appeared macroscopically and histologically normal, with the presence of abundant spermatozoa. Owing to the method adopted for the irradiation of the mice, the testes were too far from the source of radiation, and too well protected by the intervening tissue to be definitely affected by the rays. PMID- 19871947 TI - BANANA GEL. AB - The conditions for the formation of gels from banana extracts were studied. Gels were obtained with extracts more alkaline than pH 7.0 with very small quantities of calcium, strontium, and barium salts, the gel formation with these salts decreasing in the indicated order. In solutions more acid than pH 6.0, no gels were obtained with these salts. Magnesium, lithium, and sodium salts did not cause gel formation either in acid or alkaline solutions. Pancreatine gave a gel on incubation with banana extract at pH 5.0. The gel-forming property of banana extracts was destroyed on boiling. PMID- 19871948 TI - QUANTITATIVE LAWS IN REGENERATION : III. THE QUANTITATIVE BASIS OF POLARITY IN REGENERATION. AB - It is well known that a long defoliated piece of stem of Bryophyllum calycinum forms shoots only at the apical or the two apical nodes, while when such a stem is cut into as many pieces as there are nodes each node produces shoots. It is shown in this paper that the dry weight of shoots produced in the apical nodes of a long piece of stem is approximately equal to the dry weight of shoots the same stem would have produced if it had been cut into as many pieces as it possesses nodes. Hence all the material which can be used for the growth of shoots goes into the most apical part of the stem and this accounts for the polar character of regeneration in this case. It seems that the mass of basal roots produced by a piece of defoliated stem also increases with the mass of the stem. PMID- 19871949 TI - ELECTRICAL CHARGES OF COLLOIDAL PARTICLES AND ANOMALOUS OSMOSIS. AB - 1. It has been shown in previous publications that when solutions of different concentrations of salts are separated by collodion-gelatin membranes from water, electrical forces participate in addition to osmotic forces in the transport of water from the side of the water to that of the solution. When the hydrogen ion concentration of the salt solution and of the water on the other side of the membrane is the same and if both are on the acid side of the isoelectric point of gelatin (e.g. pH 3.0), the electrical transport of water increases with the valency of the cation and inversely with the valency of the anion of the salt in solution. Moreover, the electrical transport of water increases at first with increasing concentration of the solution until a maximum is reached at a concentration of about M/32, when upon further increase of the concentration of the salt solution the transport diminishes until a concentration of about M/4 is reached, when a second rise begins, which is exclusively or preeminently the expression of osmotic forces and therefore needs no further discussion. 2. It is shown that the increase in the height of the transport curves with increase in the valency of the cation and inversely with the increase in the valency of the anion is due to the influence of the salt on the P.D. (E) across the membrane, the positive charge of the solution increasing in the same way with the valency of the ions mentioned. This effect on the P.D. increases with increasing concentration of the solution and is partly, if not essentially, the result of diffusion potentials. 3. The drop in the transport curves is, however, due to the influence of the salts on the P.D. (epsilon) between the liquid inside the pores of the gelatin membrane and the gelatin walls of the pores. According to the Donnan equilibrium the liquid inside the pores must be negatively charged at pH 3.0 and this charge is diminished the higher the concentration of the salt. Since the electrical transport is in proportion to the product of E x epsilon and since the augmenting action of the salt on E begins at lower concentrations than the depressing action on epsilon, it follows that the electrical transport of water must at first rise with increasing concentration of the salt and then drop. 4. If the Donnan equilibrium is the sole cause for the P.D. (epsilon) between solid gelatin and watery solution the transport of water through collodion-gelatin membranes from water to salt solution should be determined purely by osmotic forces when water, gelatin, and salt solution have the hydrogen ion concentration of the isoelectric point of gelatin (pH = 4.7). It is shown that this is practically the case when solutions of LiCl, NaCl, KCl, MgCl(2), CaCl(2), BaCl(2), Na(2)SO(4), MgSO(4) are separated by collodion-gelatin membranes from water; that, however, when the salt has a trivalent (or tetravalent?) cation or a tetravalent anion a P.D. between solid isoelectric gelatin and water is produced in which the wall assumes the sign of charge of the polyvalent ion. 5. It is suggested that the salts with trivalent cation, e.g. Ce(NO(3))(3), form loose compounds with isoelectric gelatin which dissociate electrolytically into positively charged complex gelatin-Ce ions and negatively charged NO(3) ions, and that the salts of Na(4)Fe(CN)(6) form loose compounds with isoelectric gelatin which dissociate electrolytically into negatively charged complex gelatin Fe(CN)(6) ions and positively charged Na ions. The Donnan equilibrium resulting from this ionization would in that case be the cause of the charge of the membrane. PMID- 19871950 TI - DOES THE KINETICS OF TRYPSIN DIGESTION DEPEND ON THE FORMATION OF A COMPOUND BETWEEN ENZYME AND SUBSTRATE. AB - 1. The velocity of hydrolysis of gelatin by trypsin increases more slowly than the gelatin concentration and finally becomes nearly independent of the gelatin concentration. The relative velocity of hydrolysis of any two substrate concentrations is independent of the quantity of enzyme used to make the comparison. 2. The rate of hydrolysis is independent of the viscosity of the solution. 3. The percentage retardation of the rate of hydrolysis by inhibiting substances, is independent of the substrate concentration. 4. There is experimental evidence that the enzyme and inhibiting substance are combined to form a widely dissociated compound. 5. If the substrate were also combined with the enzyme, an increase in the substrate concentration should affect the equilibrium between the enzyme and the inhibiting substance. This is not the case. 6. The rate of digestion of a mixture of casein and gelatin is equal to the sum of the rates of hydrolysis of the two substances alone, as it should be if the rate is proportional to the concentration of free enzyme. This contradicts the saturation hypothesis. 7. If the reaction is followed by determining directly the change in the substrate concentration, it is found that this change agrees with the law of mass action; i.e., the rate of digestion is proportional to the substrate concentration. PMID- 19871951 TI - THE INFLUENCE OF X-RAYS ON THE PROPERTIES OF BLOOD. AB - When rabbits are exposed to x-radiation as described, there results a definite change in the See PDF for Equation ratio of their plasma. This change is evidently one which defines a state of uncompensated alkali excess. The time required for a maximum change in the chemical reaction is the same as that required for a maximum change in the decrease of leucocytes. Sodium bicarbonate injected into the peritoneal cavity is followed by results identical with those observed following exposure to x-rays. The maximum changes occur in a shorter time following bicarbonate injection, but the relation between chemical and morphological changes are the same. We consider this analogy to be an important one in that it is suggestive of a relationship between the effect of salt and the effect of x-rays. PMID- 19871952 TI - KINETICS OF THE BIOLUMINESCENT REACTION IN CYPRIDINA. I. PMID- 19871953 TI - KINETICS OF THE BIOLUMINESCENT REACTION IN CYPRIDINA. II. AB - 1. The decay curve of the light produced in the course of the luminescent reaction in Cypridina is, after the first second, in complete agreement with the theoretical expectation for a monomolecular reaction, if light intensity at any instant is assumed to be proportional to reaction velocity at that instant. It is shown that for such a reaction log I = - kt + log Ak and that the experimental values satisfy this equation. 2. The first second or two of the reaction is characterized by a brilliant initial flash, whose value is much too high to accord with the succeeding intensities and with the above formula. It is suggested that this initial high reaction velocity is an indication of a heterogeneous system. 3. Identical solutions run simultaneously give decay curves which check within the limits of the photographic error. 4. Stirring does not affect the reaction velocity or the form of the decay curve. 5. Reaction velocity is proportional to enzyme concentration, over the range of concentrations used in the study. 6. Changes in the concentration of the substrate do not affect the value of k, when all other factors are held constant. A diminution of luciferin concentration results only in a decrease in the value of the y-intercept, Log Ak, the two straight line plottings for two different concentrations being parallel. 7. The temperature coefficient is high, being about 4.5 for the 15-25 degrees interval, and 3.0 for the 25-35 degrees interval. PMID- 19871954 TI - A NOTE ON THE ACTION OF CURARE, ATROPINE, AND NICOTINE ON THE INVERTEBRATE HEART. AB - 1. The alkaloids (curare, atropine, and nicotine) in molluscs and arthropods stimulate and paralyze the central nervous system and peripheral (visceral) ganglia, but do not paralyze the motor nerve endings to skeletal or visceral muscle. 2. They stimulate and paralyze the denervated heart. 3. They paralyze or block the cardioinhibitory nerves, but not the cardioaccelerator nerves. 4. In the Limulus heart these drugs act primarily on the heart ganglion, not on the heart muscle or the intrinsic motor nerve fibers. PMID- 19871955 TI - THE EFFECT OF TEMPERATURE ON THE PHOTOTROPIC RESPONSE OF NECTURUS. PMID- 19871956 TI - EFFECT OF COCAINE ON THE GROWTH OF LUPINUS ALBUS. A CONTRIBUTION TO THE COMPARATIVE PHARMACOLOGY OF ANIMAL AND PLANT PROTOPLASM. AB - 1. The effects of cocaine and its decomposition products were studied on the growth of the young roots of Lupinus albus. 2. The results obtained were compared with similar experiments on animal tissues. 3. It was found that, while cocaine is the most toxic of these compounds studied for animal tissues, it was of comparatively low toxicity in respect to its effect on the growth of roots. On the other hand, sodium benzoate, being practically non-toxic for animals, was the most toxic of the compounds studied for the plant roots. PMID- 19871957 TI - STUDIES ON THE REGULATION OF OSMOTIC PRESSURE : II. THE EFFECT OF INCREASING CONCENTRATIONS OF ALBUMIN ON THE CONDUCTIVITY OF A SODIUM CHLORIDE SOLUTION. AB - Egg albumin, like gelatin, influences the conductivity of a 0.6 per cent NaCl solution in two ways: (a) At an hydrogen ion concentration of about pH 3.0, increasing concentrations increase the conductivity. (b) Near the isoelectric point of albumin and at the pH of the blood, increasing concentrations of albumin decrease the conductivity of the NaCl solution. PMID- 19871958 TI - ON THE EQUILIBRIUM CONDITION BETWEEN BLOOD SERUM AND SEROUS CAVITY FLUIDS. AB - 1. Comparative studies of blood serum and edema fluid from the same individual indicate that, regardless of the pathological condition present, whether the fluid be "transudate" or "exudate," certain definite qualitative chemical relations obtain. 2. The chief feature of these relations is that the edema fluid contains more Cl and less K than the blood serum; while the Na, HCO(3), Ca, urea, glucose, and non-protein nitrogen exist in approximately the same concentrations in the serum and in the edema fluid. The freezing point is also the same in both fluids, while the specific conductivity is constantly higher in the edema fluid. 3. The above mentioned variations between the edema fluid and the serum appear to be related to the difference in the concentration of protein in the two solutions. 4. The relationships between blood serum and edema fluid seem to result from a simple membrane equilibrium, influenced in part by the proteins present. PMID- 19871959 TI - THE COLLOIDAL BEHAVIOR OF EDESTIN. AB - 1. It has been shown by titration experiments that the globulin edestin behaves like an amphoteric electrolyte, reacting stoichiometrically with acids and bases. 2. The potential difference developed between a solution of edestin chloride or acetate separated by a collodion membrane from an acid solution free from protein was found to be influenced by salt concentration and hydrogen ion concentration in the way predicted by Donnan's theory of membrane equilibrium. 3. The osmotic pressure of such edestin-acid salt solutions was found to be influenced by salt concentration and by hydrogen ion concentration in the same way as is the potential difference. 4. The colloidal behavior of edestin is thus completely analogous to that observed by Loeb with gelatin, casein, and egg albumin, and may be explained by Loeb's theory of colloidal behavior, which is based on the idea that proteins react stoichiometrically as amphoteric electrolytes and on Donnan's theory of membrane equilibrium. PMID- 19871960 TI - THE ELIMINATION OF DISCREPANCIES BETWEEN OBSERVED AND CALCULATED P.D. OF PROTEIN SOLUTIONS NEAR THE ISOELECTRIC POINT WITH THE AID OF BUFFER SOLUTIONS. AB - 1. It had been noticed in the previous experiments on the influence of the hydrogen ion concentration on the P.D. between protein solutions inside a collodion bag and aqueous solutions free from protein that the agreement between the observed values and the values calculated on the basis of Donnan's theory was not satisfactory near the isoelectric point of the protein solution. It was suspected that this was due to the uncertainty in the measurements of the pH of the outside aqueous solution near the isoelectric point. This turned out to be correct, since it is shown in this paper that the discrepancy disappears when both the inside and outside solutions contain a buffer salt. 2. This removes the last discrepancy between the observed P.D. and the P. D. calculated on the basis of Donnan's theory of P.D. between membrane equilibria, so that we can state that the P.D. between protein solutions inside collodion bags and outside aqueous solutions free from protein can be calculated from differences in the hydrogen ion concentration on the opposite sides of the membrane, in agreement with Donnan's formula. PMID- 19871961 TI - ELECTRICAL CHARGES OF COLLOIDAL PARTICLES AND ANOMALOUS OSMOSIS : II. INFLUENCE OF THE RADIUS OF THE ION. AB - 1. When solutions of KCl, NaCl, or LiCl are separated from water without salt by a collodion-gelatin membrane and when the pH of both salt solution and water are on the acid side of the isoelectric point of gelatin, water diffuses from the side of pure water into the salt solution at a rate increasing inversely with the radius of the cations. 2. The adsorption theory would lead us to assume that this influence of the cations is due to an increase of the P.D. between the liquid and the membrane inside the pores of the gelatin film of the membrane, but direct measurements of this P.D. contradict such an assumption, since they show that the influence of the three salts on this P.D. is identical at pH 3.0. 3. It is found, however, that the P.D. across the membrane is affected in a similar way by the three cations as is the transport of water through the membrane. 4. This P.D. across the membrane varies inversely as the relative mobility of the three cations which suggests that the influence of the three cations on the diffusion of liquid through the membrane is partly if not essentially due to a diffusion potential. PMID- 19871962 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : I. A CONVENIENT CELL FOR MICROSCOPIC CATAPHORESIS EXPERIMENTS.. PMID- 19871963 TI - AN APPARATUS FOR MACROSCOPIC CATAPHORESIS EXPERIMENTS. PMID- 19871964 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : II. THE AGGLUTINATION OF THE BACILLUS OF RABBIT SEPTICEMIA AND OF BACILLUS TYPHOSUS BY ELECTROLYTES. AB - 1. Measurements have been made of the potential and of the cohesive force at the surface of Bacillus typhosus and the bacillus of rabbit septicemia in solutions of various salts and acids. 2. Electrolytes in low concentration (0.01 N) affect primarily the potential, and in high concentration decrease the cohesive force. 3. As long as the cohesive force is not affected, agglutination occurs whenever the potential is reduced below about 15 millivolts. 4. When the cohesive force is decreased the critical potential is also decreased, and in concentrated salt solution no agglutination occurs even though there is no measurable potential. PMID- 19871965 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : III. AGGLUTINATION IN THE PRESENCE OF PROTEINS, NORMAL SERUM, AND IMMUNE SERUM. AB - 1. The addition of proteins or serum to suspensions of bacteria, (Bacillus typhosus or rabbit septicemia) at different pH widens the acid agglutination zone and shifts the isoelectric point to that of the added substance. 2. The amount of serum required to agglutinate is much less near the acid agglutination point of the organisms. 3. The addition of immune serum prevents the salt from decreasing the cohesive force between the organisms, and agglutination therefore is determined solely by the potential, provided excess immune body is present. Whenever the potential is decreased below 15 millivolts the suspension agglutinates. PMID- 19871966 TI - THE FLOCCULATION OF BACTERIA BY PROTEINS. AB - 1. The effect of adding pure proteins to bacterial suspensions at different H ion concentrations has been studied. 2. The zone of flocculation of protein-treated bacteria bears a significant relationship to the isoelectric point of the protein used. With the higher concentration of protein, agglutination occurs at or near the isoelectric point of that protein; at reactions acid to this, the bacteria carry a positive charge and are not agglutinated. With diminishing concentration of protein, the zone of flocculation shifts toward and goes beyond that characteristic of the untreated bacteria. This occurs both in the presence and absence of salts. 3. A diversity of other suspensions, such as sols of gold, mastic, cellulose nitrate, cellulose acetate, Fe(OH)(3), oil emulsions, and erythrocytes, have been found by ourselves and others to exhibit a similar altered stability when treated with proteins in the same way. PMID- 19871967 TI - FURTHER STUDIES ON EOSIN HEMOLYSIS. AB - Additional experimental work on the subject of eosin hemolysis has been carried out. This indicates that red cells may be protected against the toxic action of eosin in sunlight by the presence of inorganic reducing agents. It is pointed out that a marked parallelism exists between the substances which react with the Folin and Denis reagent and the compounds which afford protection to red cells against the photodynamic action of eosin. The property which is possessed in common by all of the substances is that they are easily oxidized, and their ability to protect red cells lies in their power of reduction. The toxic action of eosin probably involves the oxidation of tyrosine and tryptophane which are contained in the protein molecules of the stroma. PMID- 19871968 TI - THE CALIBRATION OF THE OSTERHOUT RESPIRATORY APPARATUS FOR ABSOLUTE QUANTITIES OF CARBON DIOXIDE. PMID- 19871969 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS : I. THE SOLUBILITY OF CERTAIN PROTEINS AT THEIR ISOELECTRIC POINTS. AB - 1. Two proteins of the globulin type, serum globulin and tuberin, and the protein of milk, casein, have been purified (a) of the other proteins and (b) of the inorganic electrolytes with which they exist in nature. The methods that were employed are described. 2. All three proteins were found to be only very slightly soluble in water in the pure uncombined state. The solubility of each was accurately measured at 25.0 degrees +/- 0.1 degrees C. The most probable solubility of the pseudoglobulin of serum was found to be 0.07 gm. in 1 liter; of tuberin 0.1 gm. and of casein 0.11 gm. The methods that were employed in their determination are described. 3. Each protein investigated dissolved in water to a constant and characteristic extent when the amount of protein precipitate with which the solution was in heterogeneous equilibrium was varied within wide limits. The solubility of a pure protein is therefore proposed as a fundamental physicochemical constant, which may be used in identifying and in classifying proteins. 4. The concentration of protein dissolved must be the sum of the concentration of the undissociated protein molecule which is in heterogeneous equilibrium with the protein precipitate, and of the concentration of the dissociated protein ions. 5. The dissociated ions of the dissolved protein give a hydrogen ion concentration to water that is also a characteristic of each protein. PMID- 19871970 TI - CELL PENETRATION BY ACIDS : V. NOTE ON THE ESTIMATION OF PERMEABILITY CHANGES. AB - The penetration of acid into mantle tissue of Chromodoris zebra is accelerated after local faradic stimulation, and is retarded by brief treatment with anesthetic solutions. The spontaneous outward diffusion of intracellular pigment is an inadequate criterion of "permeability." Outward diffusion of pigment and penetration of acid are both facilitated when the tissue is artificially put under tension. PMID- 19871971 TI - THE COMBINATION OF GELATIN WITH HYDROCHLORIC ACID. AB - The amount of HCl combined with a given weight of gelatin has been determined by hydrogen electrode measurements in 1 per cent, 2.5 per cent, and 5 per cent solutions of gelatin in HCl of various concentrations, by correcting for the amount of HCl necessary to give the same pH to an equal volume of water without protein. The curve so obtained indicates that the amount of HCl combined with 1 gm. of gelatin is constant between pH 1 and 2, being about 0.00092 moles. PMID- 19871972 TI - THE MECHANISM BY WHICH TRIVALENT AND TETRAVALENT IONS PRODUCE AN ELECTRICAL CHARGE ON ISOELECTRIC PROTEIN. AB - 1. Experiments on anomalous osmosis suggested that salts with trivalent cations, e.g. LaCl(3), caused isoelectric gelatin to be positively charged, and salts with tetravalent anions, e.g. Na(4)Fe(CN)(6), caused isoelectric gelatin to be negatively charged. In this paper direct measurements of the P.D. between gels of isoelectric gelatin and an aqueous solution as well as between solutions of isoelectric gelatin in a collodion bag and an aqueous solution are published which show that this suggestion was correct. 2. Experiments on anomalous osmosis suggested that salts like MgCl(2), CaCl(2), NaCl, LiCl, or Na(2)SO(4) produce no charge on isoelectric gelatin and it is shown in this paper that direct measurements of the P.D. support this suggestion. 3. The question arose as to the nature of the mechanism by which trivalent and tetravalent ions cause the charge of isoelectric proteins. It is shown that salts with such ions act on isoelectric gelatin in a way similar to that in which acids or alkalies act, inasmuch as in low concentrations the positive charge of isoelectric gelatin increases with the concentration of the LaCl(3) solution until a maximum is reached at a concentration of LaCl(3) of about M/8,000; from then on a further increase in the concentration of LaCl(3) diminishes the charge again. It is shown that the same is true for the action of Na(4)Fe(CN)(6). From this it is inferred that the charge of the isoelectric gelatin under the influence of LaCl(3) and Na(4)Fe(CN)(6) at the isoelectric point is due to an ionization of the isoelectric protein by the trivalent or tetravalent ions. 4. This ionization might be due to a change of the pH of the solution, but experiments are reported which show that in addition to this influence on pH, LaCl(3) causes an ionization of the protein in some other way, possibly by the formation of a complex cation, gelatin-La. Na(4)Fe(CN)(6) might probably cause the formation of a complex anion of the type gelatin-Fe(CN)(6). Isoelectric gelatin seems not to form such compounds with Ca, Na, Cl, or SO(4). 5. Solutions of LaCl(3) and Na(4)Fe(CN)(6) influence the osmotic pressure of solutions of isoelectric gelatin in a similar way as they influence the P.D., inasmuch as in lower concentrations they raise the osmotic pressure of the gelatin solution until a maximum is reached at a concentration of about M/2,048 LaCl(3) and M/4,096 Na(4)Fe(CN)(6). A further increase of the concentration of the salt depresses the osmotic pressure again. NaCl, LiCl, MgCl(2), CaCl(2), and Na(2)SO(4) do not act in this way. 6. Solutions of LaCl(3) have only a depressing effect on the P.D. and osmotic pressure of gelatin chloride solutions of pH 3.0 and this depressing effect is quantitatively identical with that of solutions of CaCl(2) and NaCl of the same concentration of Cl. PMID- 19871973 TI - IONIZING INFLUENCE OF SALTS WITH TRIVALENT AND TETRAVALENT IONS ON CRYSTALLINE EGG ALBUMIN AT THE ISOELECTRIC POINT. AB - 1. While crystalline egg albumin is highly soluble in water at low temperature at the pH of its isoelectric point, it is coagulated by heating. It has long been known that this coagulation can be prevented by adding either acid or alkali, whereby the protein is ionized. 2. It is shown in this paper that salts with trivalent or tetravalent ions, e.g. LaCl(3) or Na(4)Fe(CN)(6), are also able to prevent the heat coagulation of albumin at the isoelectric point (i.e. pH 4.8), while salts with a divalent ion, e.g. CaCl(2), BaCl(4), Na(2)SO(4), or salts like NaCl, have no such effect. 3. This is in harmony with the fact shown in a preceding paper that salts with trivalent or tetravalent ions can cause the ionization of proteins at its isoelectric point and thus give rise to a membrane potential between micellae of isoelectric protein and surrounding aqueous solution, while the above mentioned salts with divalent and monovalent ions have apparently no such effect. PMID- 19871974 TI - ON THE INFLUENCE OF AGGREGATES ON THE MEMBRANE POTENTIALS AND THE OSMOTIC PRESSURE OF PROTEIN SOLUTIONS. AB - 1. It is shown that when part of the gelatin in a solution of gelatin chloride is replaced by particles of powdered gelatin (without change of pH) the membrane potential of the solution is influenced comparatively little. 2. A measurement of the hydrogen ion concentration of the gelatin chloride solution and the outside aqueous solution with which the gelatin solution is in osmotic equilibrium, shows that the membrane potential can be calculated from this difference of hydrogen ion concentration with an accuracy of half a millivolt. This proves that the membrane potential is due to the establishment of a membrane equilibrium and that the powdered particles participate in this membrane equilibrium. 3. It is shown that a Donnan equilibrium is established between powdered particles of gelatin chloride and not too strong a solution of gelatin chloride. This is due to the fact that the powdered gelatin particles may be considered as a solid solution of gelatin with a higher concentration than that of the weak gelatin solution in which they are suspended. It follows from the theory of membrane equilibria that this difference in concentration of protein ions must give rise to potential differences between the solid particles and the weaker gelatin solution. 4. The writer had shown previously that when the gelatin in a solution of gelatin chloride is replaced by powdered gelatin (without a change in pH), the osmotic pressure of the solution is lowered the more the more dissolved gelatin is replaced by powdered gelatin. It is therefore obvious that the powdered particles of gelatin do not participate in the osmotic pressure of the solution in spite of the fact that they participate in the establishment of the Donnan equilibrium and in the membrane potentials. 5. This paradoxical phenomenon finds its explanation in the fact that as a consequence of the participation of each particle in the Donnan equilibrium, a special osmotic pressure is set up in each individual particle of powdered gelatin which leads to a swelling of that particle, and this osmotic pressure is measured by the increase in the cohesion pressure of the powdered particles required to balance the osmotic pressure inside each particle. 6. In a mixture of protein in solution and powdered protein (or protein micellae) we have therefore two kinds of osmotic pressure, the hydrostatic pressure of the protein which is in true solution, and the cohesion pressure of the aggregates. Since only the former is noticeable in the hydrostatic pressure which serves as a measure of the osmotic pressure of a solution, it is clear why the osmotic pressure of a protein solution must be diminished when part of the protein in true solution is replaced by aggregates. PMID- 19871975 TI - THE VISIBILITY OF MONOCHROMATIC RADIATION AND THE ABSORPTION SPECTRUM OF VISUAL PURPLE. AB - 1. After a consideration of the existing data and of the sources of error involved, an arrangement of apparatus, free from these errors, is described for measuring the relative energy necessary in different portions of the spectrum in order to produce a colorless sensation in the eye. 2. Following certain reasoning, it is shown that the reciprocal of this relative energy at any wave length is proportional to the absorption coefficient of a sensitive substance in the eye. The absorption spectrum of this substance is then mapped out. 3. The curve representing the visibility of the spectrum at very low intensities has exactly the same shape as that for the visibility at high intensities involving color vision. The only difference between them is their position in the spectrum, that at high intensities being 48 micromicro farther toward the red. 4. The possibility is considered that the sensitive substances responsible for the two visibility curves are identical, and reasons are developed for the failure to demonstrate optically the presence of a colored substance in the cones. The shift of the high intensity visibility curve toward the red is explained in terms of Kundt's rule for the progressive shift of the absorption maximum of a substance in solvents of increasing refractive index and density. 5. Assuming Kundt's rule, it is deduced that the absorption spectrum of visual purple as measured directly in water solution should not coincide with its position in the rods, because of the greater density and refractive index of the rods. It is then shown that, measured by the position of the visibility curve at low intensities, this shift toward the red actually occurs, and is about 7 or 8 micromicro in extent. Examination of the older data consistently confirms this difference of position between the curves representing visibility at low intensities and those representing the absorption spectrum of visual purple in water solution. 6. It is therefore held as a possible hypothesis, capable of direct, experimental verification, that the same substance-visual purple-whose absorption maximum in water solution is at 503 micromicro, is dissolved in the rods where its absorption maximum is at 511 micromicro, and in the cones where its maximum is at 554 micromicro (or at 540 micromicro, if macular absorption is taken into account, as indeed it must be). PMID- 19871976 TI - THE INFLUENCE OF ELECTROLYTES ON THE CATAPHORETIC CHARGE OF COLLOIDAL PARTICLES AND THE STABILITY OF THEIR SUSPENSIONS : I. EXPERIMENTS WITH COLLODION PARTICLES. AB - 1. When collodion particles suspended in water move in an electric field they are, as a rule, negatively charged. The maximal cataphoretic P.D. between collodion particles and water is about 70 millivolts. This is only slightly more than the cataphoretic P.D. found by McTaggart to exist between gas bubbles and water (55 millivolts). Since in the latter case the P.D. is entirely due to forces inherent in the water itself, resulting possibly in an excess of OH ions in the layer of water in contact and moving with the gas bubble, it is assumed that the negative charge of the collodion particles is also chiefly due to the same cause; the collodion particles being apparently only responsible for the slight difference in maximal P.D. of water-gas and water-collodion surfaces. 2. The cataphoretic charge of collodion particles seems to be a minimum in pure water, increasing as a rule with the addition of electrolytes, especially if the cation of the electrolyte is monovalent, until a maximal P.D. is reached. A further increase in the concentration of the electrolyte depresses the P.D. again. There is little difference in the action of HCl, NaOH, and NaCl or LiCl or KCl. 3. The increase in P.D. between collodion particles and water upon the addition of electrolyte is the more rapid the higher the valency of the anion. This suggests that this increase of negative charge of the collodion particle is due to the anions of the electrolyte gathering in excess in the layer of water nearest to the collodion particles, while the adjoining aqueous layer has an excess of cations. 4. In the case of chlorides and at a pH of about 5.0 the maximal P.D. between collodion particles and water is about 70 millivolts, when the cation of the electrolyte present is monovalent (H, Li, Na, K); when the cation of the electrolyte is bivalent (Mg, Ca), the maximal P.D. is about 35 to 40 millivolts; and when the cation is trivalent (La) the maximal P.D. is lower, probably little more than 20 millivolts. 5. A reversal in the sign of charge of the collodion particles could be brought about by LaCl(3) but not by acid. 6. These results on the influence of electrolytes on the cataphoretic P.D. between collodion particles and water are also of significance for the theory of electrical endosmose and anomalous osmosis through collodion membranes; since the cataphoretic P.D. is probably identical with the P.D. between water and collodion inside the pores of a collodion membrane through which the water diffuses. 7. The cataphoretic P.D. between collodion particles and water determines the stability of suspensions of collodion particles in water, since rapid precipitation occurs when this P.D. falls below a critical value of about 16 millivolts, regardless of the nature of the electrolyte by which the P.D. is depressed. No peptization effect of plurivalent anions was noticed. PMID- 19871977 TI - THE COLLOIDAL BEHAVIOR OF SERUM GLOBULIN. AB - 1. The globulin prepared from ox serum by dilution and precipitation with carbon dioxide has been found, by electrometric titration experiments, to behave like an amphoteric electrolyte, reacting stoichiometrically with acids and bases. 2. The potential difference developed between a solution of globulin chloride, phosphate, or acetate and a solution of the corresponding acid, free from protein, separated from the globulin by a collodion membrane, was found to be influenced by hydrogen ion concentration and salt concentration in the way predicted by Donnan's theory of membrane equilibrium. In experiments with sodium globulinate and sodium hydroxide it was found that the potential difference could be similarly explained. 3. The osmotic pressure of such solutions could be qualitatively accounted for by the Donnan theory, but exhibited a discrepancy which is explicable by analogy with certain experiments of Loeb on gelatin. 4. The application of Loeb's theory of colloidal behavior, which had previously been found to hold in the case of gelatin, casein, egg albumin, and edestin, has thus been extended to another protein, serum globulin. PMID- 19871978 TI - THE EXCRETION OF CARBON DIOXIDE BY RELAXED AND CONTRACTED SEA ANEMONES. AB - 1. The metabolism of the sea anemone Metridium marginatum Edw. was measured in four states, relaxed, relaxing, contracted, and contracting, by means of an Osterhout respiratory apparatus. The basis of measurement was the number of hundred-thousandths of a milligram of carbon dioxide excreted per second by a gram of living sea anemone. 2. In the relaxed state this varied from 6.1 to 4.4+ and averaged 5.43-. 3. In a comparison of the relaxed and contracted states the amount of carbon dioxide excreted was found to beabout the same; in one instance in relaxation 4.2 and in contraction 4.1+; in another in relaxation 7.8+ and 7.9- and in contraction 8.1-. 4. In a comparison of the three states relaxed, relaxing, and contracting, the first two were found to average about the same, 4.8+ and 4.6- respectively and the last proved to be appreciably higher 7.1-. 5. It is, therefore, concluded that the process of relaxing and the states of relaxation and of contraction are accompanied by no unusual metabolism, but that in the operation of contracting the metabolism becomes about half again as intense as that characteristic of the other states. 6. The maintenance of the contracted state in Metridium for days at a time without an increase of metabolism indicates that its musculature is of the type known as tonus muscle. 7. In tonus muscle, contraction is accomplished by an active shortening of the myofibrils, extension by a passive drawing out of these fibrils through the distension of the adjacent cavities, etc., and the continued maintenance of any particular state of shortening by some form of catch mechanism in the muscle, such, possibly, as the gelation of its sarcoplasm. PMID- 19871979 TI - CELL PENETRATION BY ACIDS : VI. THE CHLOROACETIC ACIDS. AB - Measurements of the penetration of tissue from Chromodoris zebra are believed to show that a determining factor in penetration involves the establishment of a critical pH (near 3.5) in relation to superficial cell proteins. The rapidity with which this state is produced depends upon acid strength, and upon some property of the acid influencing the speed of absorption; hence it is necessary to compare acids within groups of chemical relationship. The actual speed of penetration observed with any acid is dependent upon two influences: preliminary chemical combination with the outer protoplasm, followed by diffusion. The variation of the temperature coefficient of penetration velocity with the concentration of acid, and the effect of size (age) of individual providing the tissue sample agree in demonstrating the significant part played by diffusion. In comparing different acids, however, their mode of chemical union with the protoplasm determines the general order of penetrating ability. PMID- 19871980 TI - ABSORPTION OF NUTRIENTS AND PLANT GROWTH IN RELATION TO HYDROGEN ION CONCENTRATION. AB - The absorption of nutrients depends to a large extent on the reaction of the substrate. At maximal growth the intake of salt is at minimum. Different ions are very differently affected. The intake of water is independent of the absorption of salts. PMID- 19871981 TI - CATAPHORETIC CHARGES OF COLLODION PARTICLES AND ANOMALOUS OSMOSIS THROUGH COLLODION MEMBRANES FREE FROM PROTEIN. AB - 1. It had been shown in previous papers that when a salt solution is separated from pure water by a collodion membrane, water diffuses through the membrane as if it were positively charged and as if it were attracted by the anion of the salt in solution and repelled by the cation with a force increasing with the valency. In this paper, measurements of the P.D. across the membrane (E) are given, showing that when an electrical effect is added to the purely osmotic effect of the salt solution in the transport of water from the side of pure water to the solution, the latter possesses a considerable negative charge which increases with increasing valency of the anion of the salt and diminishes with increasing valency of the cation. It is also shown that a similar valency effect exists in the diffusion potentials between salt solutions and pure water without the interposition of a membrane. 2. This makes it probable that the driving force for the electrical transport of water from the side of pure water into solution is primarily a diffusion potential. 3. It is shown that the hydrogen ion concentration of the solution affects the transport curves and the diffusion potentials in a similar way. 4. It is shown, however, that the diffusion potential without interposition of the membrane differs in a definite sense from the P.D. across the membrane and that therefore the P.D. across the membrane (E) is a modified diffusion potential. 5. Measurements of the P.D. between collodion particles and aqueous solutions (epsilon) were made by the method of cataphoresis, which prove that water in contact with collodion particles free from protein practically always assumes a positive charge (except in the presence of salts with trivalent and probably tetravalent cations of a sufficiently high concentration). 6. It is shown that an electrical transport of water from the side of water into the solution is always superposed upon the osmotic transport when the sign of charge of the solution in the potential across the membrane (E) is opposite to that of the water in the P.D. between collodion particle and water (epsilon); supporting the theoretical deductions made by Bartell. 7. It is shown that the product of the P.D. across the membrane (E) into the cataphoretic P.D. between collodion particles and aqueous solution (epsilon) accounts in general semiquantitatively for that part of the transport of water into the solution which is due to the electrical forces responsible for anomalous osmosis. PMID- 19871982 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : IV. THE COMBINATION OF ANTIGEN AND ANTIBODY AT DIFFERENT HYDROGEN ION CONCENTRATIONS. AB - 1. The amount of immune body required to agglutinate a suspension of Bacillus typhosus increases in direct proportion to the concentration of the suspension. 2. The amount of immune body combined with the organisms is constant from pH 9 to pH 3.7. Below the latter value the amount in combination is decreased. 3. The addition of immune serum to a suspension of Bacillus typhosus at a pH of 2,5 increases the positive charge of the organisms. These results are contradictory to the idea that the combination is caused by a difference in the sign of the charge carried by the immune body and the organism. They agree with the assumption that the immune body forms a film on the surface of the organism and that the effect on the charge is the result of this film. PMID- 19871983 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : V. THE REMOVAL OF ANTIBODY FROM SENSITIZED ORGANISMS. AB - 1. The removal of antibody from Bacillus typhosus is no more complete at pH 3 than at pH 7. 2. Approximately twelve agglutinating doses are firmly combined with the organisms. Immune body in excess of this amount is easily removable by distilled water. 3. A method of testing for the presence of immune body on the organism is described which depends on the difference in the acid agglutination of sensitized and unsensitized organisms. 4. Repeated washing in distilled water will serve to remove all the immune body from sensitized bacteria. PMID- 19871984 TI - THE ADHESIVENESS OF LEUCOCYTES TO SOLID SURFACES. AB - 1. Methods are described for measuring the stickiness of cells to solid surfaces. 2. The effect of various factors such as temperature, serum concentration, sodium chloride concentration, etc., on the adhesiveness of leucocytes to solid surfaces and the phagocytosis of solid particles are compared, and certain marked differences pointed out. 3. On account of these differences it is concluded that forces of surface tension, though undoubtedly operative in determining the behavior of cells in contact with solid bodies, are not the only factors involved. 4. Ways in which changes in the structure or rigidity of the protoplasm might affect phagocytosis and adhesiveness in opposite directions are suggested. PMID- 19871985 TI - EFFECT OF THE HYDROGEN ION CONCENTRATION ON THE PHAGOCYTOSIS AND ADHESIVENESS OF LEUCOCYTES. AB - 1. Immediately after coming into contact with glass, leucocytes are most adhesive at pH 8.0 or > 8.0. 2. Agglutination of leucocytes increases with increasing H ion concentration from pH 8.0 to 6.0. 3. In phagocytosis experiments where leucocytes creep about on the slide picking up articles the optimum pH is 7.0. Here ameboid movement is probably the limiting factor. 4. The optimum for phagocytosis of quartz from suspension is on the acid side of neutrality at or near pH 6.7. 5. Phagocytosis of quartz increases with the acidity, while adhesiveness of leucocytes to glass increases with the alkalinity. PMID- 19871986 TI - THE INFLUENCE OF AMMONIUM SALTS ON CELL REACTION. AB - 1. It may be shown by means of cells of the flowers of a hybrid Rhododendron which contain a natural indicator, by means of starfish eggs stained with neutral red, and by means of an "artificial cell" in which living frog's skin is employed that increased intracellular alkalinity may be brought about by solutions of a decidedly acid reaction which contain ammonium salts. 2. These results are analogous to those previously obtained with the CO(2)-bicarbonate system, and depend on the facts: (a) that NH(4)OH is sufficiently weak as a base to permit a certain degree of hydrolysis of its salts; and (b) that living cells are freely permeable to NH(4)OH (or NH(3)?) and not to mineral and many organic acids, and presumably not at least to the same extent to ammonium salts as such. PMID- 19871987 TI - A MICRO INJECTION STUDY ON THE PERMEABILITY OF THE STARFISH EGG. AB - The experiments with the NH(4)Cl are similar to, and corroborate micro injection experiments performed in connection with some work on mustard gas in which the writer collaborated. Eggs immersed in sea water containing decomposed mustard gas, at a certain low concentration are not affected. If, however, the solution be injected, the egg quickly cytolyzes owing to the free HCl present. A similar impermeability of the protoplasmic surface film to certain substances was also encountered in injection work on Amoeba. Amoeboe immersed in an aqueous solution of eosin will not take the stain till after death. On the other hand, the eosin, when injected into the Amoeba, quickly permeates the protoplasm, to be arrested only at the surface. The semipermeability of a living cell appears primarily to be a function of its surface film. It is immaterial whether this film be that of the original cortex of the cell, a film newly formed over a cut surface, or a film that surrounds an artificially induced vacuole within the cell. As long as such a surface film exists neither the acid group of the NH(4)Cl nor the alkaline group of the NaHCO(3) can, within certain concentration limits, penetrate the protoplasm. These solutions, if injected beneath the surface film, however, will produce their characteristic effects upon the protoplasm. PMID- 19871988 TI - THE RELATION OF THE REACTION AND OF SALT CONTENT OF THE MEDIUM ON NITRIFYING BACTERIA. PMID- 19871989 TI - THE EQUIVALENCE OF AGE IN ANIMALS. AB - 1. A method of plotting growth curves is presented which is considered more useful than the usual method in bringing out a number of important phenomena such as the equivalence of age in different animals, difference in the shape and duration of corresponding growth cycles in different animals, and also in determinating the age of maxima without resorting to complicated mathematical computations. 2. It is suggested that after the third cycle is past the conceptional age of the maximum of the third cycle may be taken as the age of reference for estimating the equivalent physiological ages in different animals. Before the age of the third cycle, the maxima of the second and first cycles are most conveniently used as points of reference. 3. It is shown that the product of the conceptional age of the maximum of the third cycle by 13, gives a value which is, with the possible exception of man, very near to the normal duration of life of animals under the most favorable conditions of life. In other words, the equivalent physiological ages in different animals bear an approximately constant linear relation to the duration of their growth periods. 4. Attention is called to certain differences in the shape and duration of the corresponding growth cycles in different animals and of the effect of sex on these cycles. PMID- 19871990 TI - THE PERMEABILITY OF CELLS FOR OXYGEN AND ITS SIGNIFICANCE FOR THE THEORY OF STIMULATION. AB - It can be demonstrated by an indicator method that living cells are as freely permeable to oxygen as dead cells, and that sudden admission of oxygen to the cell cannot account for increased oxidation as a result of stimulation. Oxygen penetrates as readily as carbon dioxide among the acids and ammonia among the alkalies. Exposure of living plant cells to high oxygen pressures does not initiate certain oxidations (except after some hours), which proceed readily in dead plant cells in the air. In the light of the preceding statement, about the permeability of cells for oxygen, this is interpreted to mean that more oxygen enters the cell at high pressure, but that the reacting substances (chromogen and oxidase) are kept apart by some phase boundary as long as the cell is alive. Increased oxygen concentration eventually produces injury to the cell. PMID- 19871991 TI - THE PERMEABILITY OF LIVING CELLS TO DYES AS AFFECTED BY HYDROGEN ION CONCENTRATION. AB - 1. An accurate quantitative method of measuring the penetration of dye into the living cell is described. 2. Cresyl blue is unable to penetrate rapidly unless the pH outside the cell is decidedly greater than that inside. The rate of penetration increases with increasing pH. 3. Around pH 9 penetration of the dye is rapid while the reverse is true of exosmosis. At low pH values (5.9) exosmosis is rapid and penetration is very slow. PMID- 19871992 TI - SOME ASPECTS OF SELECTIVE ABSORPTION. AB - 1. A mechanism exists in Valonia which prevents certain substances (Na, Mg, Ca, SO(4)) from reaching as high a concentration inside the cell as in the sea water which surrounds it. 2. A trapping mechanism also exists which causes K to accumulate in the cell in a concentration far in excess of that found in sea water. Practically all the K in the cell exists in the form of KCl. 3. The concentration of Cl does not differ greatly within and without. 4. These facts are not in harmony with present theories regarding the accumulation of K in living cells. PMID- 19871993 TI - SODIUM CHLORIDE AND SELECTIVE DIFFUSION IN LIVING ORGANISMS. AB - 1. It is shown that NaCl acts like CaCl(2) or LaCl(3) in preventing the diffusion of strong acids through the membrane of the egg of Fundulus with this difference only that a M/8 solution of NaCl acts like a M/1,000 solution of CaCl(2) and like a M/30,000 solution of LaCl(3). 2. It is shown that these salts inhibit the diffusion of non-dissociated weak acid through the membrane of the Fundulus egg but slightly if at all. 3. Both NaCl and CaCl(2) accelerate the diffusion of dissociated strong alkali through the egg membrane of Fundulus and CaCl(2) is more efficient in this respect than NaCl. 4. It is shown that in moderate concentrations NaCl accelerates the rate of diffusion of KCl through the membrane of the egg of Fundulus while CaCl(2) does not. PMID- 19871994 TI - THE INFLUENCE OF SALTS ON THE RATE OF DIFFUSION OF ACID THROUGH COLLODION MEMBRANES. AB - 1. The writer had previously published the observation that if a salt solution made up in an acid solution (e.g. HCl) of a definite pH (e.g. 3.0) is separated by a collodion membrane from pure water containing the same acid of the same pH, acid is at first driven from the salt solution into the water, so that the pH of the latter becomes at first lower than that of the solution. 2. It is shown in this paper that this paradoxical phenomenon is not due to any peculiarity of the membrane but is a consequence of the well known fact that the diffusion constant of an acid is increased by a salt. PMID- 19871995 TI - THE MECHANISM OF THE INFLUENCE OF ACIDS AND ALKALIES ON THE DIGESTION OF PROTEINS BY PEPSIN OR TRYPSIN. AB - 1. The effect of the addition of acid on the amount of ionized protein has been compared with the effect on the rate of digestion of gelatin, casein, and hemoglobin by pepsin. 2. A similar comparison has been made of the addition of alkali in the case of trypsin with gelatin, casein, hemoglobin, globin, and edestin. 3. In general, the rate of digestion may be predicted from the amount of ionized protein as determined by the titration curve or conductivity. The rate of digestion is a minimum at the isoelectric point of the protein and a maximum at that pH at which the protein is completely combined with acid or alkali to form a salt. 4. The physical properties of the protein solution have little or no effect on the rate of digestion. PMID- 19871996 TI - STUDIES ON BIOLUMINESCENCE : XV. ELECTROREDUCTION OF OXYLUCIFERIN. AB - Oxyluciferin may be reduced to luciferin at cathodes, when an electric current is passed through the solution, or at cathodes formed by metal couples in solution, or at cathodes of oxidation-reduction cells of the NaCl - Pt - Pt - Na(2)S type. It is also reduced at those metal surfaces (Al, Mn, Zn, and Cd) which liberate nascent hydrogen from water, although no visible hydrogen gas separates from the surface. Molecular hydrogen does not reduce oxyluciferin even though very finely divided but will reduce oxyluciferin in contact with palladium. Palladium has no reducing action except in presence of hydrogen, and apparently acts as a catalyst by virtue of some power of converting molecular into atomic hydrogen. Conditions are described under which a continuous luminescence of luciferin can be obtained. This luminescence may be used as a test for atomic hydrogen. It is suggested that the steady luminescence of bacteria is due to continuous oxidation of luciferin to oxyluciferin and reduction of oxyluciferin to luciferin in different parts of the bacterial cell. PMID- 19871997 TI - ON THE GROWTH AND RESPIRATION OF SULFUR-OXIDIZING BACTERIA. AB - 1. It is shown that Sulfomonas thiooxidans oxidizes elementary sulfur completely to sulfuric acid. Sodium thiosulfate is oxidized by this organism completely to sulfate. Sulfomonas thiooxidans differs, in this respect, from various other sulfur-oxidizing bacilli which either produce elementary sulfur, from the thiosulfate, or convert it into sulfates and persulfates. 2. The organism derives its carbon from the CO(2) of the atmosphere, but is incapable of deriving the carbon from carbonates or organic matter. 3. The S:C, or ratio between the amount of sulfur oxidized to sulfate and amount of carbon assimilated chemosynthetically from the CO(2) of the atmosphere, is, with elementary sulfur as a source of energy, 31.8, and with thiosulfate 64.2. The higher ratio in the case of the thiosulfate is due to the smaller amount of energy liberated in the oxidation of sulfur compound than in the elementary form. 4. Of the total energy made available in the oxidation of the sulfur to sulfuric acid, only 6.65 per cent is used by the organism for the reduction of atmospheric CO(2) and assimilation of carbon. 5. Sulfates do not exert any injurious effect upon sulfur oxidation by Sulfomonas thiooxidans. Any effect obtained is due to the cation rather than the sulfate radical. Nitrates exert a distinctly injurious action both on the growth and respiration of the organism. 6. There is a definite correlation between the amount of sulfur present and velocity of oxidation, very similar to that found in the growth of yeasts and nitrifying bacteria. Oxidation reaches a maximum with about 25 gm. of sulfur added to 100 cc. of medium. However, larger amounts of sulfur have no injurious effect. 7. Dextrose does not exert any appreciable injurious effect in concentrations less than 5 per cent. The injurious effect of peptone sets in at 0.1 per cent concentration and brings sulfur oxidation almost to a standstill in 1 per cent concentration. Dextrose does not exert any appreciable influence upon sulfur oxidation and carbon assimilation from the carbon dioxide of the atmosphere. 8. Sulfomonas thiooxidans can withstand large concentrations of sulfuric acid. The oxidation of sulfur is affected only to a small extent even by 0.25 molar initial concentration of the acid. In 0.5 molar solutions, the injurious effect becomes marked. The organism may produce as much as 1.5 molar acid, without being destroyed. 9. Growth is at an optimum at a hydrogen ion concentration equivalent to pH 2.0 to 5.5, dropping down rapidly on the alkaline side, but not to such an extent on the acid, particularly when a pure culture is employed. 10. Respiration of the sulfur-oxidizing bacteria can be studied by using the filtrate of a vigorously growing culture, to which a definite amount of sulfur is added, and incubating for 12 to 24 hours. PMID- 19871998 TI - THE PHAGOCYTOSIS OF SOLID PARTICLES : IV. CARBON AND QUARTZ IN SOLUTIONS OF VARYING ACIDITY. AB - 1. Leucocytes ingest quartz particles more readily than carbon in acid solutions, and carbon more readily than quartz in alkaline solutions. 2. In the presence of acacia carbon is always preferred to quartz even in acid solutions. 3. Manganese dioxide particles are ingested by leucocytes with extraordinary rapidity as compared with manganese silicate or quartz. 4. Leucocytes are not attracted toward carbon or quartz particles but manganese dioxide exerts a distinct attraction for them. 5. Spores of Penicillium are ingested more readily than quartz. 6. Very small quartz particles, 1 micron in diameter, are not ingested as readily as larger particles of the same material. This result being contrary to the predictions of surface tension indicates that some other factor is involved in the ingestion of these small particles. 7. Measurements of the carbon electrode potentials and the cataphoretic charges on the particles have failed to supply an explanation for the varying relative rates of ingestion of carbon and quartz with varying hydrogen ion concentration. PMID- 19871999 TI - MUSCLE TENSION AND REFLEXES IN THE EARTHWORM. AB - 1. By the use of preparations of earthworm in which the cutaneous receptors have been anesthetized with a solution of M/8 MgCl(2), it is shown that peristalsis can be initiated by tension alone. 2. The receptors of the tension reflex are the intermyal sensory cells of the ventral region of the body wall. 3. It is concluded that Straub obtained the tension reflex because his preparations contained the intermyal receptors; Budington was unable to observe the tension reflex in any preparation from which the intermyal receptors had been removed. 4. Intermyal receptors are the receptors of the following reaction: Passive unilateral tension of the posterior part of an earthworm induces active homolateral tension of the musculature of the anterior segments, and results in the course of progress being brought into line with the enforced orientation of the tail. This reaction is termed the homostrophic reflex. 5. The receptors for the reaction are distributed throughout the entire length of the worm, the effectors are limited to the anterior 15 to 20 segments. The impulse is conducted by the ventral nerve cord. 6. The interaction of the homostrophic reflex and tropisms is considered. PMID- 19872000 TI - A STUDY OF THE EQUILIBRIUM BETWEEN THE SO CALLED "ANTITRYPSIN" OF THE BLOOD AND TRYPSIN. AB - 1. The retarding effect of plasma on the action of trypsin can be measured quantitatively. 2. The nature of the reaction involved in effecting the retardation has been subjected to an experimental study. 3. Evidence is presented which indicates that the equilibrium between the inhibitive agent and trypsin is reached practically instantaneously and is rapidly and completely reversible. 4. This equilibrium has been studied by experiments in which we have observed (1) the effect of adding increasing amounts of plasma to a constant amount of trypsin, (2) the effect of varying the amount of trypsin while the plasma was constant, (3) the effect of dilution on the trypsin-plasma mixture. 5. The results of these experiments are discussed and it is stated that they are in quantitative agreement with the law of mass action. 6. An equation was found which fits the curves for the experiments mentioned in (4). This equation was developed from the assumption that 1 molecule of trypsin combined with 1 molecule of inhibitor to form 1 molecule of trypsin-inhibitor compound. The agreement between the results calculated by this equation and the observed results is satisfactory. It is pointed out that the equation contains two arbitrary constants and the bearing this fact may have on the calculated results is discussed. 7. We conclude from the results of our study that we have adduced evidence which suggests the following statement regarding the so called "antitryptic" property of blood. The inhibitive agent and trypsin combine to form an inactive but dissociable compound. The reaction in equilibrium is expressed by the equation Trypsin + inhibitor right harpoon over left harpoon trypsin inhibitor The conditions of equilibrium are apparently governed by the law of mass action. The behavior of the equilibrium is therefore similar to the behavior of other equilibria between different inhibitive agents and enzymes discussed in the paper. PMID- 19872001 TI - A METHOD FOR THE QUANTITATIVE DETERMINATION OF TRYPSIN AND PEPSIN. AB - A quantitative method is described which permits a determination of the relative amount of trypsin or pepsin present in a gelatin-enzyme digestion mixture, provided the gelatin and trypsin solutions are purified. This method is dependent upon the change in viscosity of such solutions. It is found that the time required to cause a given percentage change in the viscosity is nearly inversely proportional to the amount of enzyme present. It is pointed out that the particular value of the method lies in the fact that enzyme reactions which take place in the presence of "buffer" salts may be studied. PMID- 19872002 TI - FURTHER OBSERVATIONS ON THE INFLUENCE OF SALTS WHEN INJECTED INTO THE ANIMAL BODY. AB - A satisfactory correlation of our observations dealing with the influence of salts and those dealing with the influence of x-rays is not possible at present. Any far reaching conclusion is not permitted because the information we have at this time regarding the physical chemical conditions concerned in the process of injury, as well as that pertaining to the nature of radio-chemical reactions, is too meager. As far as the experiments with salts are concerned, it may be said that we are dealing with ion effects, and their importance in physiological processes is made clear by the investigations of Loeb (3) and those of Osterhout (4). The results that we have obtained in our experiments present an interesting analogy between the effect of x-rays and certain salts on the lymphoid elements of the animal body. We regard this analogy as significant in that it presents suggestions regarding the chemical nature of x-ray effects in the animal body. PMID- 19872003 TI - CONDUCTIVITY AS A MEASURE OF VITALITY AND DEATH. AB - The conductance of Laminaria, Saccharomyces, Bacillus coli and Bacillus butyricus, Chlorella, and of red blood cells has been studied by the writer's method, and Laminaria by that of Osterhout. For the material studied it has been found that: 1. The conductance of living tissue is closely proportionate to, and determined by that of the surrounding fluid with which it is apparently in equilibrium. Changes in the conductance of the fluid are quickly followed by compensatory changes in that of the tissue. 2. A quantity is defined which is independent of the conductivity of the fluid bathing the tissues. This is called the "net conductance." 3. All the tissues studied, even when dead, offer a resistance to the passage of current greater than that of the surrounding solution. Exceptions which occur under certain conditions will be discussed in a later paper. 4. In view of the wide variety of material studied it seems admissible, in the absence of any evidence to the contrary, to suppose that these conclusions are generally applicable. PMID- 19872004 TI - THE IONIZATION OF PROTEIN CHLORIDES. AB - 1. By the use of the silver-silver chloride electrode, measurements have been made of the chloride ion concentrations of 1 per cent solutions of five proteins, containing from 0.001 N to 0.1 N hydrochloric acid. The hydrogen ion concentrations of the same solutions have been measured by the use of the hydrogen electrode. 2. The measurements indicate that the chlorides of gelatin, egg albumin, casein, edestin, and serum globulin are highly ionized electrolytes, ionizing to yield chloride ion and a positive protein-hydrogen ion. Their ionization is therefore similar to that of ammonium chloride. 3. The results do not support the idea that a protein chloride does not yield chloride ion on dissociation. They are not in agreement with the idea that the depressing effect of an excess of HCl on the viscosity and other colloidal properties of a protein chloride solution is due to a repression of the ionization of the protein chloride. The results are, however, in complete accord with the theory of colloidal behavior advocated by Loeb. PMID- 19872005 TI - THE INFLUENCE OF ELECTROLYTES ON THE CATAPHORETIC CHARGE OF COLLOIDAL PARTICLES AND THE STABILITY OF THEIR SUSPENSIONS : II. EXPERIMENTS WITH PARTICLES OF GELATIN, CASEIN, AND DENATURED EGG ALBUMIN. AB - 1. This paper gives measurements of the influence of various electrolytes on the cataphoretic P.D. of particles of collodion coated with gelatin, of particles of casein, and of particles of boiled egg albumin in water at different pH. The influence of the same electrolyte was about the same in all three proteins. 2. It was found that the salts can be divided into two groups according to their effect on the P.D. at the isoelectric point. The salts of the first group including salts of the type of NaCl, CaCl(2), and Na(2)SO(4) affect the P.D. of proteins at the isoelectric point but little; the second group includes salts with a trivalent or tetravalent ion such as LaCl(3) or Na(4)Fe(CN)(6). These latter salts produce a high P.D. on the isoelectric particles, LaCl(3) making them positively and Na(4)Fe(CN)(6) making them negatively charged. This difference in the action of the two groups of salts agrees with the observations on the effect of the same salts on the anomalous osmosis through collodion membranes coated with gelatin. 3. At pH 4.0 the three proteins have a positive cataphoretic charge which is increased by LaCl(3) but not by NaCl or CaCl(2), and which is reversed by Na(4)Fe(CN)(6), the latter salt making the cataphoretic charge of the particles strongly negative. 4. At pH 5.8 the protein particles have a negative cataphoretic charge which is strongly increased by Na(4)Fe(CN)(6) but practically not at all by Na(2)SO(4) or NaCl, and which is reversed by LaCl(3). the latter salt making the cataphoretic charge of the particles strongly positive. 5. The fact that electrolytes affect the cataphoretic P.D. of protein particles in the same way, no matter whether the protein is denatured egg albumin or a genuine protein like gelatin, furnishes proof that the solutions of genuine proteins such as crystalline egg albumin or gelatin are not diaphasic systems, since we shall show in a subsequent paper that proteins insoluble in water, e.g. denatured egg albumin, are precipitated when the cataphoretic P.D. falls below a certain critical value, while water-soluble proteins, e.g. genuine crystalline egg albumin or gelatin, stay in solution even if the P.D. of the particles falls below the critical P.D. PMID- 19872006 TI - THE MECHANISM OF THE EFFECT OF ACIDS AND ALKALIES ON THE DIGESTION OF PROTEINS BY PEPSIN OR TRYPSIN : A CORRECTION. PMID- 19872007 TI - CIRCUS MOVEMENTS OF LIMULUS AND THE TROPISM THEORY. AB - 1. Under laboratory conditions Limulus from 20 to 60 mm. in diameter are positively phototropic, and execute circus movements towards the normal side, when the median and the opposite lateral eyes are removed or covered. 2. The phototropism of Limulus may be modified or obliterated by (a) fright, (b) hunger, (c) stereotropism, (d) photokinesis, and (e) unknown stimuli. 3. Quantitative measurements of the paths of animals doing circus movements demonstrate that the amount of turning varies directly with the light intensity as follows: for 8,000 candle meters the degrees turned per centimeter were 6.73; for 2,000 candle meters, 5.23; and for 900 candle meters, 4.78. In other words, the diameter of the circle varies inversely with the light intensity. 4. The rate of locomotion per minute also varies directly with the light intensity, being 178 cm. for 8,000 candle meters, 167 for 2,000, and 157 for 900. 5. These reactions are satisfactorily explained by the tropism theory. PMID- 19872008 TI - THE BEHAVIOR OF CHLORIDES IN THE CELL SAP OF NITELLA. AB - 1. A method is given for determining the chloride content in a drop (less than 0.03 cc.) of the cell sap of Nitella. 2. Chlorides accumulate in the sap to the extent of 0.128 M; this accumulation can be followed during the growth of the cell. The chloride content does not increase when the cell is placed for 2 days in solutions (at pH 6.2) containing chlorides up to 0.128 M. 3. The exosmosis of chlorides from injured cells can be followed quantitatively. When one end of the cell is cut off a wave of injury progresses toward the other end; this is accompanied by a progressive exosmosis of chlorides. PMID- 19872009 TI - A NEW VISCOMETER. AB - A viscometer is described, particularly adapted to the measurement of colloidal solutions and physiological liquids (serum, blood), which, although doing away with the capillary tube (which is difficult to handle and to clean), requires less than 1 cc. of liquid. The readings are rapid, from 30 seconds to 1 minute. The temperature is easily controlled and varied. The range is considerable and may be changed easily. The sensitivity is such that the viscosity of air can be measured to the 7th decimal, without any difficulty. Its main advantage is that it makes possible the observation of the changes occurring in the viscosity of a liquid in function of time and temperature. It may be used as a recording viscometer by simply placing a recording photographic box before the mirror. PMID- 19872010 TI - THE RATE OF DECLINE OF MILK SECRETION WITH THE ADVANCE OF THE PERIOD OF LACTATION. AB - It is shown that the course of decline of milk secretion with the advance of the period of lactation may be expressed by the equation of a monomolecular chemical reaction; that is, the percentage decline of milk secretion with the advance of the stage of lactation is constant. This substantiates the idea that milk secretion is limited by a chemical reaction, and, in general, brings lactation into the class of processes the speed of which is determined by the concentration of a limiting substance. PMID- 19872011 TI - THE RATE OF GROWTH OF THE DAIRY COW : II. GROWTH IN WEIGHT AFTER THE AGE OF TWO YEARS. AB - An extensive amount of data is presented on the growth in weight of the dairy cow from 2 to 17 years of age, covering practically the entire duration of life. The data show that after the age of 2 years the rate of growth declines in a non cyclic manner. The course of decline in growth follows the course of decline of a monomolecular chemical reaction; that is, the percentage decline in growth with age is constant. PMID- 19872013 TI - GALVANOTROPISM IN THE EARTHWORM. PMID- 19872012 TI - THE REACTION OF NEREIS VIRENS TO UNILATERAL TENSION OF ITS MUSCULATURE. AB - 1. The anterior segments of Nereis are oriented reflexly by passive unilateral tension of the posterior musculature. 2. The afferent impulses of the homostrophic reflex rise from any part of the worm and are conducted forward by way of the ventral nerve cord. 3. The efferent impulses flow out from the brain and anterior two or three ventral ganglia. 4. The homostrophic reflex may be partially or wholly masked by stereotropism. PMID- 19872014 TI - THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS : III. THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE RETENTION OF POTASSIUM. AB - By perfusing frogs for varying periods with potassium-free Ringer solutions having a pH ranging from 6.0 to 8.0, it has been determined that such solutions have little or no effect upon the retention of potassium by muscle cells. PMID- 19872015 TI - COMPARATIVE STUDIES ON RESPIRATION : XXIV. THE EFFECTS OF CHLOROFORM ON THE RESPIRATION OF DEAD AND OF LIVING TISSUE. AB - 1. Chloroform in low concentration (0.25 per cent) causes an increase in the rate of production of CO(2) in Ulva; this is followed by a decrease. In higher concentration (0.5 per cent) only a decrease is observed. 2. Assuming that the normal oxidation depends on the action of peroxide and peroxidase, experiments were made by placing Ulva in 1.0 per cent H(2)O(2) and in Fe(2)(SO(4))(3) (which acts like a peroxidase). The former diminishes the rate, the latter increases and subsequently decreases it. 3. When Ulva is killed in such a manner as to destroy the oxidizing enzymes, no CO(2) is produced unless H(2)O(2) and Fe(2)(SO(4))(3) are present. If to this mixture chloroform is added, the effect depends on the concentration of the iron. If the concentration is low there is an increase in the production of CO(2) followed by a decrease. If the concentration is high the rate appears to decrease from the start. PMID- 19872017 TI - MEMBRANE POTENTIALS AND CATAPHORETIC POTENTIALS OF PROTEINS. AB - 1. It has been shown in preceding publications that the membrane potentials of protein solutions or gels are determined by differences in the concentration of a common ion (e.g. hydrogen ion) inside a protein solution or protein gel and an outside aqueous solution free from protein, and that the membrane potentials can be calculated with a good degree of accuracy from Donnan's equation for membrane equilibria. 2. On the basis of the theory of electrical double layers developed by Helmholtz, we are forced to assume that the cataphoretic potentials of protein particles are determined by a difference in the concentration of the two oppositely charged ions of the same electrolyte in the two strata of an electrical double layer surrounding the protein particle but situated entirely in the aqueous solution. 3. The membrane potentials of proteins agree with the cataphoretic potentials in that the sign of charge of the protein is negative on the alkaline side and positive on the acid side of the isoelectric point of the protein in both membrane potentials and cataphoretic potentials. The two types of potential of proteins disagree, especially in regard to the action of salts with trivalent and tetravalent ions on the sign of charge of the protein. While low concentrations of these salts bring about a reversal of the sign of the cataphoretic potentials of protein particles (at least in the neighborhood of the isoelectric point), the same salts can bring the membrane potentials of proteins only to zero, but call bring about no or practically no reversal of the sign of charge of the protein. Where salts seem to bring about a reversal in the membrane potential of protein solutions, the reversal is probably in reality always due to a change in the pH. 4. We may state, as a result of our experiments, that the cataphoretic migration and the cataphoretic P.D. of protein particles or of suspended particles coated with a protein are the result of two groups of forces; namely, first, forces inherent in the protein particles (these forces being linked with the membrane equilibrium between protein particles and the outside aqueous solution); and second, forces inherent entirely in the aqueous solution surrounding the protein particles. The forces inherent in the protein particles and linked with the membrane equilibrium prevail to such an extent over the forces inherent in the water, that the sense of the cataphoretic migration of protein particles is determined by the forces resulting from the membrane equilibrium. PMID- 19872016 TI - STABILITY OF SUSPENSIONS OF SOLID PARTICLES OF PROTEINS AND PROTECTIVE ACTION OF COLLOIDS. AB - 1. It is shown that the concentrations of different salts required to precipitate suspensions of gelatin-coated collodion particles in water are practically identical with the concentrations of the same salts required for the "salting out" of gelatin from aqueous solutions. Neither effect shows any relation to the electrical double layers surrounding the particles. 2. It is shown that at the isoelectric point of gelatin, suspensions of gelatin-coated collodion particles are not stable and it had been shown previously that gelatin is least soluble at the isoelectric point. The addition of salt increases both the solubility of gelatin in water as well as the stability of suspensions of gelatin-coated collodion particles in water, and both effects increase with the valency of one of the ions of the salt. 3. This latter effect is not due to any charges conferred on the gelatin particles by the salts, since the cataphoretic experiments show that salts like NaCl, Na(2)SO(4), or CaCl(2), which at the isoelectric point of gelatin increase the solubility of gelatin as well as the stability of suspensions of gelatin-coated collodion particles, leave the particles practically uncharged in the concentrations in which the salts are efficient. 4. It follows from all these facts that the stability of suspensions of gelatin-coated particles in water depends on the solubility of gelatin in water; e.g., on the chemical affinity of certain groups of the gelatin molecule for water. 5. Though crystalline egg albumin is highly soluble in water, the stability of collodion particles coated with crystalline egg albumin does not depend upon the affinity of the albumin molecule for water, but depends practically alone on the electrical double layer surrounding each particle. As soon as the P.D. of this double layer falls below 13 millivolts, the suspension is no longer stable. 6. The critical potential for the stability of suspensions of collodion particles coated with genuine egg albumin is the same as that for particles of boiled (denatured) white of egg. Since through the process of heating, egg albumin loses its solubility in water, it is inferred that egg albumin undergoes the same change when it forms a film around a solid particle like collodion. 7. The influence of electrolytes on the stability of suspensions of collodion particles coated with casein or edestin was similar to that of collodion particles coated with egg albumin. The experiments are, however, complicated by the fact that near the isoelectric point CaCl(2) and even NaCl cause a suspension again at concentrations of about M/2 or 1 M, while still higher concentrations may cause a precipitation again. These latter effects have no connection with double layers, but belong probably in the category of solubility phenomena. 8. These experiments permit us to define more definitely the conditions for a general protective action of colloids. Protective colloids must be capable of forming a durable film on the surface of the suspended particles and the molecules constituting the film must have a higher attraction for the molecules of the solvent than for each other; in other words, they must possess true solubility. Only in this case can they prevent the precipitating action of low concentrations of electrolytes on particles which are kept in suspension solely by the high potentials of an electrical double layer. Thus gelatin films, in which the attraction of the molecules for water is preserved, have a general protective action, while crystalline egg albumin, casein, and edestin, which seem to lose their attraction for water when forming a film, have a protective action only under limited conditions stated in the paper. PMID- 19872018 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS : II. THE RELATION BETWEEN THE SOLUBILITY OF CASEIN AND ITS CAPACITY TO COMBINE WITH BASE. THE SOLUBILITY OF CASEIN IN SYSTEMS CONTAINING THE PROTEIN AND SODIUM HYDROXIDE. AB - 1. The solubility in water of purified, uncombined casein has previously been reported to be 0.11 gm. in 1 liter at 25 degrees C. This solubility represents the sum of the concentrations of the casein molecule and of the soluble ions into which it dissociates. 2. The solubility of casein has now been studied in systems containing the protein and varying amounts of sodium hydroxide. It was found that casein forms a well defined soluble disodium compound, and that solubility was completely determined by (a) the solubility of the casein molecule, and (b) the concentration of the disodium casein compound. 3. In our experiments each mol of sodium hydroxide combined with approximately 2,100 gm. of casein. 4. The equivalent combining weight of casein for this base is just half the minimal molecular weight as calculated from the sulfur and phosphorus content, and one sixth the minimal molecular weight calculated from the tryptophane content of casein. 5. From the study of systems containing the protein and very small amounts of sodium hydroxide it was possible to determine the solubility of the casein molecule, and also the degree to which it dissociated as a divalent acid and combined with base. 6. Solubility in such systems increased in direct proportion to the amount of sodium hydroxide they contained. 7. The concentration of the soluble casein compound varied inversely as the square of the hydrogen ion concentration, directly as the solubility of the casein molecule, Su, and as the constants Ka(1) and Ka(2) defining its acid dissociation. 8. The product of the solubility of the casein molecule and its acid dissociation constants yields the solubility product constant, Su.Ka(1).Ka(2) = 2.2 x 10(-12) gm. casein per liter at 25 degrees C. 9. The solubility of the casein molecule has been estimated from this constant, and also from the relation between the solubility of the casein and the sodium hydroxide concentration, to be approximately 0.09 gm. per liter at 25 degrees C. 10. The product of the acid dissociation constants, Ka(1) and Ka(2), must therefore be 24 x 10(-12)N. 11. It is believed that these constants completely characterize the solubility of casein in systems containing the protein and small amounts of sodium hydroxide. PMID- 19872019 TI - SENSORY ADAPTATION AND THE STATIONARY STATE. AB - 1. Experiments are described which measure the sensitivity of animals exposed to continued illumination to which they have become adapted. It is shown that the amount of outside light energy necessary to stimulate an adapted animal increases with the intensity of the adapting illumination. 2. The data are analyzed quantitatively in terms of the reversible reaction S right harpoon over left harpoon P + A shown previously to account for the photic sensitivity of these animals. This analysis demonstrates that, though the amount of incident energy necessary for a minimal response varies with the adapting intensity, the actual amount of photochemical decomposition required to set off the sensory mechanism is a constant quantity. 3. The ability of these animals to come into sensory equilibrium with any sustained illumination is accounted for quantitatively by the presence of a stationary state in the reversible photochemical reaction S right harpoon over left harpoon P + A during which the concentrations of the three components are constant. 4. It is shown that the concentrations of these substances at the stationary state are automatically controlled by the outside intensity. Therefore, given the sensory mechanism as a basis, the adaptation of the animals to light and the consequent changes in sensitivity, are determined entirely by the light to which the animals are exposed. 5. Because of the properties of the stationary state, and of the constancy of photochemical decomposition for a minimal effect, it is suggested that the sensory system is not only the traditional receptor system, but is also a protecting layer which stabilizes and buffers the relation between the nervous system and the environment. PMID- 19872020 TI - THE PHOTOCHEMICAL BASIS OF ANIMAL HELIOTROPISM. AB - 1. Experiments on the heliotropic orientation of Limulus were made which confirmed Loeb's photochemical theory of animal heliotropism proposed first in 1888 and 1889 in experiments on insects, and later in experiments on other forms of animals. 2. It is shown that these animals are oriented by light in such a way that the product I x t x cos alpha is the same for the symmetrical photosensitive elements of the eyes or the skin, where I is the intensity of the light, t the duration of illumination, and alpha the angle of incidence of the light at the surface element of the photosensitive organ. 3. When this equation holds, the products of decomposition by light must be the same in symmetrical elements of the eyes or skin, and the influence of these products of decomposition on the tension of symmetrical muscles of the locomotor organs of the animal must be the same. As a consequence the animal must move in the path of light, either to or from the source of light. PMID- 19872021 TI - HOMOSTROPHIC REFLEX AND STEREOTROPISM IN DIPLOPODS. AB - 1. With suitable arthropods, such as the diplopods, it can be shown that body orientation following passive unilateral tension involves the homostrophic reflex. The phenomenon is exhibited when the animal is quiescent and during forward locomotion, but nothing of the sort appears in backward locomotion. 2. Receptors for the homostrophic reflex are in the body wall and are distributed throughout the length of the animal. 3. The effector nerves take their origin from the ganglia of the head alone. 4. The diplopods are stereotropic, the head turning toward the side in contact with a solid surface only as long as some part of the body maintains contact. Under suitable conditions stereotropism may mask the homostrophic reflex. 5. When a diplopod is in contact with two lateral surfaces of equal extent the path upon emergence is a straight one, conforming to the law of the parallelogram of forces. PMID- 19872022 TI - THE STABILITY OF BACTERIAL SUSPENSIONS : VI. THE INFLUENCE OF THE CONCENTRATION OF THE SUSPENSION ON THE CONCENTRATION OF SALT REQUIRED TO CAUSE COMPLETE AGGLUTINATION. AB - 1. The concentrations of various salts required to agglutinate different concentrations for a suspension of typhoid bacilli sensitized with immune serum have been determined. 2. The electrolytes may be divided into two classes; (1) those with which the concentration required to agglutinate is independent of the concentration of the suspension; and (2) those with which the agglutinating concentration increases in proportion to the concentration of the suspension. 3. The salts comprised under (1) do not reverse the sign of the charge of the suspension. 4. The salts of Class (2) (with the exception of ZnSO(4)) do reverse the sign of the charge. PMID- 19872023 TI - COMPARATIVE STUDIES ON RESPIRATION : XXV. THE ACTION OF CHLOROFORM ON THE OXIDATION OF SOME ORGANIC ACIDS. AB - 1. Organic acids when treated with H(2)O(2) and Fe(2)(SO(4))(3) produce CO(2) at a rate that can be measured by the indicator method. 2. In the case of acids containing a double bond, the rate of production of CO(2) can be varied by the addition of an anesthetic. The changes in the rate of production of CO(2) under the influence of a typical anesthetic, such as chloroform, show a striking resemblance to the reaction of the organism. PMID- 19872024 TI - COMPARATIVE STUDIES ON RESPIRATION : XXVI. THE PRODUCTION OF CO(2)FROM ORGANIC ACIDS IN RELATION TO THEIR IODINE ABSORPTION. PMID- 19872025 TI - THE COMPOSITION OF THE CELL SAP OF THE PLANT IN RELATION TO THE ABSORPTION OF IONS. AB - 1. Chemical examination of the cell sap of Nitella showed that the concentrations of all the principal inorganic elements, K, SO(4), Ca, Mg, PO(4), Cl, and Na, were very much higher than in the water in which the plants were growing. 2. Conductivity measurements and other considerations lead to the conclusion that all or nearly all of the inorganic elements present in the cell sap exist in ionic state. 3. The insoluble or combined elements found in the cell wall or protoplasm included Ca, Mg, S, Si, Fe, and Al. No potassium was present in insoluble form. Calcium was predominant. 4. The hydrogen ion concentration of healthy cells was found to be approximately constant, at pH 5.2. This value was not changed even when the outside solution varied from pH 5.0 to 9.0. 5. The penetration of NO(3) ion into the cell sap from dilute solutions was definitely influenced by the hydrogen ion concentration of the solution. Penetration was much more rapid from a slightly acid solution than from an alkaline one. It is possible that the NO(3) forms a combination with some constituent of the cell wall or of the protoplasm. 6. The exosmosis of chlorine from Nitella cells was found to be a delicate test for injury or altered permeability. 7. Dilute solutions of ammonium salts caused the reaction of the cell sap to increase its pH value. This change was accompanied by injury and exosmosis of chlorine. 8. Apparently the penetration of ions into the cell may take place from a solution of low concentration into a solution of higher concentration. 9. Various comparisons with higher plants are drawn, with reference to buffer systems, solubility of potassium, removal of nitrate from solution, etc. PMID- 19872026 TI - THE EFFECT OF RADIO-ACTIVE RADIATIONS AND X-RAYS ON ENZYMES : I. THE EFFECT OF RADIATIONS FROM RADIUM EMANATION ON SOLUTIONS OF TRYPSIN. AB - A quantitative study has been made of the radiochemical decomposition of trypsin by the radiations from radium emanation. The following equation accounts quantitatively for the experimental results presented. See PDF for Equation It follows from this that the amount of trypsin decomposed by the radiations from radium emanation depends on the concentration of trypsin present and is proportional to the quantity of emanation expressed in millicuries and to the time of irradiation expressed in hours. It would seem that it is the active or undissociated trypsin that is affected. Evidence has been found which suggests that the beta radiations produce the decomposition observed for which the above statement holds. Qualitative evidence has been found which suggests that x-rays, gamma rays, and beta rays produce identical effects in dilute trypsin solutions. PMID- 19872027 TI - MEMBRANE POTENTIALS IN THE DONNAN EQUILIBRIUM. PMID- 19872028 TI - VALENCY RULE AND ALLEGED HOFMEISTER SERIES IN THE COLLOIDAL BEHAVIOR OF PROTEINS : I. THE ACTION OF ACIDS. AB - 1. The action of a number of acids on four properties of gelatin (membrane potentials, osmotic pressure, swelling, and viscosity) was studied. The acids used can be divided into three groups; first, monobasic acids (HCl, HBr, HI, HNO(3), acetic, propionic, and lactic acids); second, strong dibasic acids (H(2)SO(4) and sulfosalicylic acid) which dissociate as dibasic acids in the range of pH between 4.7 and 2.5; and third, weak dibasic and tribasic acids (succinic, tartaric, citric) which dissociate as monobasic acids at pH 3.0 or below and dissociate increasingly as dibasic acids, according to their strength, with pH increasing above 3.0. 2. If the influence of these acids on the four above mentioned properties of gelatin is plotted as ordinates over the pH of the gelatin solution or gelatin gel as abscissae, it is found that all the acids have the same effect where the anion is monovalent; this is true for the seven monobasic acids at all pH and for the weak dibasic and tribasic acids at pH below 3.0. The two strong dibasic acids (the anion of which is divalent in the whole range of pH of these experiments) have a much smaller effect than the acids with monovalent anion. The weak dibasic and tribasic acids act, at pH above 3.0, like acids the anion of which is chiefly monovalent but which contain also divalent anions increasing with pH and with the strength of the acid. 3. These experiments prove that only the valency but not the other properties of the anion of an acid influences the four properties of gelatin mentioned, thus absolutely contradicting the Hofmeister anion series in this case which were due to the failure of the earlier experimenters to measure properly the pH of their protein solutions or gels and to compare the effects of acids at the same pH of the protein solution or protein gel after equilibrium was established. 4. It is shown that the validity of the valency rule and the non-validity of the Hofmeister anion series for the four properties of proteins mentioned are consequences of the fact that the influence of acids on the membrane potentials, osmotic pressure, swelling, and viscosity of gelatin is due to the Donnan equilibrium between protein solutions or gels and the surrounding aqueous solution. This equilibrium depends only on the valency but not on any other property of the anion of an acid. 5. That the valency rule is determined by the Donnan equilibrium is strikingly illustrated by the ratio of the membrane potentials for divalent and monovalent anions of acids. Loeb has shown that the Donnan equilibrium demands that this ratio should be 0.66 and the actual measurements agree with this postulate of the theory within the limits of accuracy of the measurements. 6. The valency rule can be expected to hold for only such properties of proteins as depend upon the Donnan equilibrium. Properties of proteins not depending on the Donnan equilibrium may be affected not only by the valency but also by the chemical nature of the anion of an acid. PMID- 19872029 TI - VALENCY RULE AND ALLEGED HOFMEISTER SERIES IN THE COLLOIDAL BEHAVIOR OF PROTEINS : II. THE INFLUENCE OF SALTS. AB - It is shown by the older experiments by Loeb and by the experiments reported in this paper that the effect of salts on the membrane potentials, osmotic pressure, swelling of gelatin chloride, and that type of viscosity which is due to the swelling of protein particles, depends only on the valency but not on the chemical nature of the anion of the salt, and that the cation of the salt has no effect on these properties, if the pH of the protein solution or protein gel is not altered by the salt. The so called Hofmeister series of salt effects on these four properties are purely fictitious and due to the failure of the former authors to measure the hydrogen ion concentration of their protein solutions or gels and to compare the effects of salts at the same pH of the protein solution or the protein gel. These results confirm the older experiments of Loeb and together they furnish a further proof for the correctness of the idea that the influence of electrolytes on the four properties of proteins is determined by membrane equilibria. Such properties of proteins which do not depend on membrane equilibria, such as solubility or cohesion, may be affected not only by the valency but also by the chemical nature of the ions of a salt. PMID- 19872030 TI - EXOSMOSIS IN RELATION TO INJURY AND PERMEABILITY. AB - The time curve expressing the increase in the permeability of Nitella during the progress of death is practically the same whether derived from measurements of exosmosis or of electrical resistance. PMID- 19872031 TI - THE PENETRATION OF DYES AS INFLUENCED BY HYDROGEN ION CONCENTRATION. AB - When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye. PMID- 19872033 TI - NOTE ON THE PURIFICATION AND PRECIPITATION OF CASEIN. PMID- 19872032 TI - COMPARATIVE STUDIES ON RESPIRATION : XXVII. THE MECHANISM OF OXIDATION IN RELATION TO CHLOROFORM ANESTHESIA. AB - A mathematical analysis of the effects of chloroform on the production of carbon dioxide by living Ulva, killed Ulva, and unsaturated organic acids indicates that the same process is taking place in all three cases. On the basis of this interpretation it is reasonable to conclude that the action of chloroform on the oxidative mechanism of the cell is chemical in nature and that it acts either by catalysis or by the formation of a loose compound with some portion of the system. PMID- 19872034 TI - THE INACTIVATION OF TRYPSIN : IV. THE ADSORPTION OF TRYPSIN BY CHARCOAL. AB - 1. Charcoal removes trypsin from solution. The amount removed depends on the order in which the solutions are mixed. The reaction is not reversible and is almost independent of the pH of the solution. 2. Charcoal which has been previously treated with gelatin does not remove trypsin from solution. 3. The reaction is not analogous either to the reaction between trypsin and the inhibiting substance of serum or to the reaction between solid protein and either pepsin or trypsin. PMID- 19872035 TI - STRUCTURAL UNITS OF STARCH DETERMINED BY X-RAY CRYSTAL STRUCTURE METHOD. AB - A few brief statements summarizing the foregoing conclusions may make a picture of the structure of the starch grain somewhat clearer. 1. The presence of lines on the negatives indicates a regular arrangement of the planes of atoms. 2. The lines are in close agreement with lines which would be produced by a lattice of the tetragonal system, the elementary cell of which is a square prism with the dimensions 5.94 x 5.94 x 5.05 A.u. 3. The unit of the lattice occupies a space equal to the volume of the starch group, C(6)H(10)O(5). 4. The large number of atoms in the unit makes it highly probable that principal planes and secondary planes of atoms occur for every reflecting position. 5. The effect of the secondary upon the principal planes may readily account for the differences in the density of the lines produced on the negatives. 6. From theoretical considerations, reflections, such as those obtained, would occur if starch grains were built up of concentric layers of units. 7. Two other factors which might affect the density of the lines are thermal agitation and the curvature of the concentric layers. 8. A model of the starch group was constructed to scale based on the accepted sizes of the atoms involved and upon rather meager chemical evidence. The model apparently fulfills the requirements necessary to produce reflections such as were obtained. 9. The model fits the elementary cell loosely enough to suggest a low density and to allow for considerable thermal movement. At the same time, parts of it approach the faces of the cell closely enough to make cohesion seem possible. 10. The model makes clearer the basis for the assumption that reflection from certain positions would be stronger than from others. If the interpretation of the data is correct and if the assumptions made are sound, then the starch grain is built up of units arranged in concentric layers, and the units are groups of atoms, each containing 6 carbon, 10 hydrogen, and 5 oxygen atoms. Such a structure is certainly not an amorphous structure, and on the other hand it is not crystalline in the common sense of the term. Parts of the grain, it is true, act as crystals in that for certain distances the layers of units are in planes, but taken as a whole the layers are curved. As to the validity of the conclusions, those pertaining to the type of lattice and to the size of the unit may be accepted as sound in our present knowledge of x-rays and crystal structure; those, however, pertaining to the nature and the spherical arrangement of the units, while they seem convincing, need the support of further investigation into the various structures deposited by living protoplasm. In conclusion, the assumption that the units form a sort of spherical space lattice, gives a picture of the starch grain which leads us to ponder over the nature of the activity in protoplasm when it is depositing solid substances. Starch, cellulose, and pectic bodies are about the only solid deposits made directly by the living substance of plants, and all three have the same proportional formula, C(6)H(10)O(5). Investigations, as yet incomplete, indicate that cellulose also consists of a regular arrangement of C(6)H(10)O(5) groups, each acting as a unit, but the spacing (6.14 x 6.14 x 5.55) is slightly different from that of starch. Pectin has not been studied. Protoplasm may be thought of as being composed of molecules of many different sizes, polypeptides, or even proteins forming the larger, and amino-acids the smaller, if water and electrolytes are ignored. The smaller molecules, such as those of the amino-acid, leucine, are approximately equal in size to the C(6)H(10)O(5) group of starch. That being the case, what can be the state of affairs at the interface when the starch particles are being deposited? Is it probable that protoplasm is homogeneous to the extent of being able to deposit these particles at 6 A.u. intervals? From quite another view point a clear picture of the units of structure and their arrangement in cellulose should give a new point of attack on the many problems connected with osmosis. And from still a different view-point, it might lead perhaps, to a solution of problems connected with swelling. Another line of thought is suggested by the uniformity of the groups in the starch grain. Since the C(6)H(10)O(5) group occurs as an individual unit, one is inclined to suspect that it is really the molecule. Generally the starch molecule is considered to be very large, to be composed of several dozens of such groups, and to have a molecular weight of 7,000 or much more. No one figure, however, seems satisfactory to the different authorities. There is already at hand considerable evidence which will be assembled in a later paper favoring the single group, C(6)H(10)O(5), as the molecule. Finally, problems in polarized light may receive more satisfactory explanations through a clearer notion of the molecular structure of the carbohydrates. PMID- 19872036 TI - THE EFFECT OF GESTATION ON THE RATE OF DECLINE OF MILK SECRETION WITH THE ADVANCE OF THE PERIOD OF LACTATION. AB - 1. Data are presented showing that the course of decline of milk secretion with the advance of the period of lactation in farrow cows follows the course of decline of a monomolecular chemical reaction, that is each month's milk production is a constant percentage of the production of the preceding month (94.77 per cent in the case of the cow under consideration), from which it is inferred that milk secretion is limited by a chemical reaction initiated at parturition, and declining with the decrease of the concentration of the limiting substance as it is transformed into milk. 2. Data are presented showing that the decline in milk secretion due to pregnancy is related to the increase in weight of gestating animals, from which it is inferred that growth of the fetus is in part, at least, responsible for the decline in the milk flow due to the demand of the fetus for nutrients to support its life processes. PMID- 19872037 TI - STUDIES IN PROTOPLASM POISONING : I. PHENOLS. AB - 1. After equilibrium of distribution of a phenol between water and an animal immersed in it has been once attained, the poisoning of the animal proceeds with constant velocity. The criterion of toxicity adopted in the first part of this study was the time required for initial recovery from paralysis after a given time in the phenol solution. In later work observations were made of the percentages of animals which died after stated periods in a phenol solution. 2. The numerical value of the velocity constant of poisoning for a given solution is independent of the criterion of toxicity adopted, provided that the criterion serves to measure the intensity of effect of the poison, and not merely the rate at which the poison is absorbed. 3. Recovery from paralysis produced by phenol and death from this poison has the same velocity constant. From this it may be inferred that recovery is due to a reversal of the mechanism which underlies poisoning. 4. The velocity of poisoning by phenols is nearly proportional to the square of the concentration. 5. A strictly chemical (mass law) interpretation is shown to be inadequate for the description of poisoning by phenols. 6. Certain physical factors, involved in poisoning by phenols, are discussed. 7. A precise method for obtaining the velocity constant of poisoning by a given agent is outlined. PMID- 19872038 TI - THE RELATION BETWEEN THE ELECTRICAL CONDUCTIVITY OF THE EXTERNAL MEDIUM AND THE RATE OF CELL DIVISION IN SEA URCHIN EGGS. AB - Dilution of sea water with isotonic sugar solution leaves the rate of cleavage of Arbacia eggs almost unchanged until the proportion of sea water is decreased to 20 or 25 volumes per cent. From this point cleavage becomes progressively slower with further dilution. Many eggs fail to cleave at dilutions of 5 to 6 volumes per cent. No cleavage occurs in 2 volumes per cent sea water or in pure sugar solution. Eggs returned from these media to sea water resume cleavage and development. There is thus no relation between the rate of cleavage and the electrical conductivity of the medium, except possibly within the range of dilutions from 20 to 5 volumes per cent sea water. In this range cleavage rate decreases as conductivity decreases, but the relation is not a linear one. PMID- 19872039 TI - A DISSECTION OF THE CHROMOSOMES IN THE POLLEN MOTHER CELLS OF TRADESCANTIA VIRGINICA L. PMID- 19872040 TI - THE MECHANISM OF THE ENTRANCE OF SPERM INTO THE STARFISH EGG. PMID- 19872041 TI - THEORY OF REGENERATION BASED ON MASS ACTION. AB - 1. The writer's older experiment, proving that equal masses of isolated sister leaves of Bryophyllum regenerate under equal conditions and in equal time equal masses (in dry weight) of shoots and roots, is confirmed. It is shown that in the dark this regeneration is reduced to a small fraction of that observed in light. 2. The writer's former observation is confirmed, that when a piece of stem inhibits or diminishes the regeneration in a leaf, the dry weight of the stem increases by as much or more than the weight by which the regeneration in the leaf is diminished. It is shown that this is also true when the axillary bud in the stem is removed or when the regeneration occurs in the dark. 3. These facts show that the regeneration of an isolated leaf of Bryophyllum is determined by the mass of material available or formed in the leaf during the experiment and that such a growth does not occur in a leaf connected with a normal plant for the reason that in the latter case the material available or formed in the leaf flows into the stem where it is consumed for normal growth. 4. It is shown that the sap sent out by a leaf in the descending current of a stem is capable of increasing also the rate of growth of shoots in the basal parts of the leaf when the sap has an opportunity to reach the anlagen for such shoots. 5. The fact that a defoliated piece of stem forms normally no shoots in its basal part therefore demands an explanation of the polar character of regeneration which lays no or less emphasis on the chemical difference between ascending and descending sap than does Sachs' theory of specific root- or shoot-forming substances (though such substances may in reality exist), but which uses as a basis the general mass relation as expressed in the first three statements of this summary. 6. It is suggested that the polar character of the regeneration in a stem of Bryophyllum is primarily due to the fact that the descending sap reaches normally only the root-forming tissues at the base of the stem, while the ascending sap reaches normally only the shoot-forming anlagen at the apex of the stem. 7. This suggestion is supported by the fact that when the anlagen for shoots and roots are close together as they are in the notch of a leaf, the sap of the leaf causes the growth of both roots and shoots from the same notch and the influence of the sap of the leaf on this growth increases for both roots and shoots in proportion with the mass of the leaf. PMID- 19872042 TI - THEORY OF GEOTROPISM BASED ON MASS ACTION. AB - 1. It is shown that the rate of geotropic curvature of a piece of stem of Bryophyllum calycinum when suspended horizontally increases with the mass of an apical leaf attached to the stem. 2. It is shown that the dry weight of the stem increases with the mass of the leaf attached and also that the degree of curvature increases with this increase in the dry weight of the stem. 3. The conclusion is drawn that geotropic curvature is in this case a function of mass action of the material sent by the leaf into the basal part of the stem. 4. The material sent by a leaf into the apical part of a stem does not lead to the same geotropic curvature. PMID- 19872043 TI - THE EFFECT OF RADIOACTIVE RADIATIONS AND X-RAYS ON ENZYMES : II. THE EFFECT OF RADIATIONS FROM RADIUM EMANATION ON PEPSIN IN SOLUTION. AB - Pepsin in solution is inactivated by the radiations (beta and gamma) from radium emanation. This chemical effect has been studied quantitatively. The principles involved in this radiochemical reaction are apparently the same as those found in the case of trypsin previously reported; namely, the change in the logarithm of the concentration of active enzyme varies directly with the variable, W. PMID- 19872044 TI - ON THE LOCATION OF THE FORCES WHICH DETERMINE THE ELECTRICAL DOUBLE LAYER BETWEEN COLLODION PARTICLES AND WATER. AB - 1. The cataphoretic P.D. of suspended particles is assumed to be due to an excess in the concentration of one kind of a pair of oppositely charged ions in the film of water enveloping the particles and this excess is generally ascribed to a preferential adsorption of this kind of ions by the particle. The term adsorption fails, however, to distinguish between the two kinds of forces which can bring about such an unequal distribution of ions between the enveloping film and the opposite film of the electrical double layer, namely, forces inherent in the water itself and forces inherent in the particle (e.g. chemical attraction between particle and adsorbed ions). 2. It had been shown in a preceding paper that collodion particles suspended in an aqueous solution of an ordinary electrolyte like NaCl, Na(2)SO(4), Na(4)Fe(CN)(6), CaCl(2), HCl, H(2)SO(4), or NaOH are always negatively charged, and that the addition of these electrolytes increases the negative charge as long as their concentration is below M/1,000 until a certain maximal P.D. is reached. Hence no matter whether acid, alkali, or a neutral salt is added, the concentration of anions must always be greater in the film enveloping the collodion particles than in the opposite film of the electrical double layer, and the reverse is true for the concentration of cations. This might suggest that the collodion particles, on account of their chemical constitution, attract anions with a greater force than cations, but such an assumption is rendered difficult in view of the following facts. 3. Experiments with dyes show that at pH 5.8 collodion particles are stained by basic dyes (i.e. dye cations) but not by acid dyes (i.e. dye anions), and that solutions of basic dyes are at pH 5.8 more readily decolorized by particles of collodion than acid dyes. It is also shown in this paper that crystalline egg albumin, gelatin, and Witte's peptone form durable films on collodion only when the protein exists in the form of a cation or when it is isoelectric, but not when it exists in the form of an anion (i.e. on the alkaline side of its isoelectric point). Hence if any ions of dyes or proteins are permanently bound at the surface of collodion particles through forces inherent in the collodion they are cations but not anions. The fact that isoelectric proteins form durable films on collodion particles suggests, that the forces responsible for this combination are not ionic. 4. It is shown that salts of dyes or proteins, the cations of which are capable of forming durable films on the surface of the collodion, influence the cataphoretic P.D. of the collodion particles in a way entirely different from that of any other salts inasmuch as surprisingly low concentrations of salts, the cation of which is a dye or a protein, render the negatively charged collodion particles positive. Crystalline egg albumin and gelatin have such an effect even in concentrations of 1/130,000 or 1/65,000 of 1 per cent, i.e. in a probable molar concentration of about 10(-9). 5. Salts in which the dye or protein is an anion have no such effect but act like salts of the type of NaCl or Na(2)SO(4) on the cataphoretic P.D. of collodion particles. 6. Amino-acids do not form durable films on the surface of collodion particles at any pH and the salts of amino-acids influence their cataphoretic P.D. in the same way as NaCl but not in the same way as proteins or dyes, regardless of whether the amino-acid ion is a cation or an anion. 7. Ordinary salts like LaCl(3) also fail to form a durable film on the surface of collodion particles. 8. Until evidence to the contrary is furnished, these facts seem to suggest that the increase of the negative charge of the collodion particles caused by the addition of low concentrations of ordinary electrolytes is chiefly if not entirely due to forces inherent in the aqueous solution but to a less extent, if at all, due to an attraction of the anions of the electrolyte by forces inherent in the collodion particles. PMID- 19872045 TI - THE MINIMUM CONCENTRATION OF OXYGEN FOR LUMINESCENCE BY LUMINOUS BACTERIA. AB - A method is described for measuring the concentration of oxygen to allow just perceptible luminescence of luminous bacteria. The value turns out to be extraordinarily low, about 0.005 mm. Hg pressure O(2) or 1 part by weight oxygen dissolved in 3,700,000,000 cc. sea water. PMID- 19872046 TI - THE RATE OF GROWTH OF THE DAIRY COW : III. THE RELATION BETWEEN GROWTH IN WEIGHT AND INCREASE OF MILK SECRETION WITH AGE. AB - It is shown that from 2 years, the age when milk secretion usually begins, to 9 years, the age of maximum body weight, the increase of milk secretion with age follows the course of growth in body weight- both can be accurately represented by the equation of a monomolecular chemical reaction having a velocity constant of approximately the same numerical value. While increase in milk secretion and increase in body weight with age follow the same course, it is shown that increasing body weight contributes only about 20 per cent to increasing milk secretion with age. The fact that milk secretion and body weight follow the same course, even though they are largely independent of each other indicates that increase in body weight is a good measure of growth of the dairy cow; this fact also shows that the increase of milk secretion with age may be used as a measure of growth. The fact that milk secretion, like body weight, follows the course of a chemical reaction, adds further support to the theory that growth is limited by a chemical reaction. PMID- 19872047 TI - THE RATE OF GROWTH OF THE DAIRY COW : IV. GROWTH AND SENESCENCE AS MEASURED BY THE RISE AND FALL OF MILK SECRETION WITH AGE. AB - Data are presented on the effect of age on milk secretion in the dairy cow. From the age when milk secretion usually begins (2 years) to the age when maximum body weight is reached (about 8 years) increase of milk secretion and increase of body weight with age follow the same exponential course, which is the course of a monomolecular reaction of chemistry. After this age, unlike body weight which remains practically constant, milk secretion declines exponentially, that is, the course of decline follows the course of decline of a monomolecular reaction. The whole course of milk secretion with age was therefore found to follow approximately the course of two simultaneous, consecutive, monomolecular reactions. This is taken to mean that growth and senescence go on simultaneously from the beginning to the end of life, and that each follows an exponential law with age; and therefore perhaps that the course of the two processes are limited by two consecutive chemical reactions. PMID- 19872048 TI - THE RATE OF SENESCENCE OF THE DOMESTIC FOWL AS MEASURED BY THE DECLINE IN EGG PRODUCTION WITH AGE. AB - Data are presented showing that the course of decline of egg production with age in the domestic fowl from the time laying begins up to and including 8 years follows an exponential law, that is, each year's egg production is a constant percentage of the preceding year's production (88 per cent in the group of fowl studied). Since the exponential law is the same as the law of monomolecular change in chemistry, and since the course of egg production with age may be taken as an index of the course of senescence of organs, or tissues limiting egg production, it is suggested that this exponential law of egg production substantiates the idea that senescence is a physicochemical process the course of which is limited by a chemical reaction. It is shown that the exhaustion of the oocytes is not likely to be the factor limiting the course of egg production. PMID- 19872049 TI - FURTHER EXPERIMENTS ON THE ABSORPTION OF IONS BY PLANTS, INCLUDING OBSERVATIONS ON THE EFFECT OF LIGHT. AB - 1. The conditions of illumination were found to exert a very significant influence on absorption of ions from dilute solution by Nitella. These conditions were also found to influence the penetration of Br and NO(3) into the cell sap. 2. It is concluded that absorption of ions by plants from dilute solutions involves energy exchanges, with light as the ultimate source of the energy. It is suggested that the absorption is intimately related to growth and metabolism. 3. One ion may affect the removal from solution or penetration into the cell sap of another ion present in the same solution, even in solutions of extremely low concentration. It is probable that all three types of relations may exist-anion to anion, cation to cation, and anion to cation. 4. The sulfate and phosphate ions exerted far less influence on the absorption of nitrate than did chlorine and bromine ions. It is suggested as a possibility that sulfate does not penetrate readily to those surfaces at which chlorine, bromine, nitrate, and other ions may become effective. PMID- 19872050 TI - CHANGES IN THE STABILITY AND POTENTIAL OF CELL SUSPENSIONS : I. THE STABILITY AND POTENTIAL OF BACTERIUM COLI. AB - 1. Stability and potential of Bacterium coli suspensions depend, not only on the strain of the organism and the medium in which it is suspended, but also on the previous treatment of the suspension, and the length of time it has been in the medium. 2. When treated at acid reactions, the negative charge on the bacteria is diminished; with some strains, a positive charge is acquired. Changes in stability accompany the changes in potential. 3. Washing acid-treated bacteria at neutral or slightly alkaline reactions does not restore the original potential; the zone of flocculation is moved toward the alkaline side. 4. These changes are due to two factors: the extraction of a soluble protein which combines with the surfaces of the cells, and a further irreversible change of the cell or its membrane. PMID- 19872051 TI - THE EFFECT OF RADIOACTIVE RADIATIONS AND X-RAYS ON ENZYMES : III. A UNIT OF MEASURE OF ACTIVITY FOR RADIUM EMANATION. AB - In this communication we have introduced a unit to express activity or power of a given preparation of radium emanation. We have named this unit the curie-power and defined it as the activity of 1 curie of radium emanation and its radioactive products in equilibrium with it. We suggest the introduction of this unit in order that we may make a more comprehensive statement of our experimental observation. In the radiochemical reaction effected by the radiations (beta and gamma) from radium emanation in which enzymes are inactivated the chemical change in a given system is a function of the product of two variables; namely, the average activity of the radium emanation, P(a), expressed in terms of the unit millicurie-power, and time, t, expressed in hours. This product has the dimensions of energy and is identical with W which is measured in terms of the energy unit, millicurie-power hours. PMID- 19872052 TI - THE FUNCTION OF THE BRAIN IN LOCOMOTION OF THE POLYCLAD WORM, YUNGIA AURANTIACA. AB - Coordinated swimming movements in Yungia are not dependent upon the presence of the brain. The neuromuscular mechanism necessary for spontaneous movement and swimming is complete in the body of the animal apart from the brain. Normally this mechanism is set in motion by sensory stimulation arriving by way of the brain. The latter is a region of low threshold and acts as an amplifier by sending the impulses into a great number of channels. When the head is cut off these connections with the sensorium are broken, consequently peripheral stimulation does not have its usual effect. If, however, the motor nerves are stimulated directly as by mechanical stimulation of the median anterior region, then swimming movements result. Also if the threshold of the entire nervous mechanism is lowered by phenol or by an increase in the ion ratios See PDF for Equation and See PDF for Equation then again peripheral stimulation throws the neuromuscular mechanism into activity and swimming movements result. PMID- 19872053 TI - STUDIES ON TOXICITY. AB - With yeast subjected to the action of phenol or of phenol and alcohol the curves of survivors as measured by resistance to staining with methylene blue when plotted against time do not in general prove to be logarithmic. It is believed that such resemblances as have been found between such curves and monomolecular reaction or logarithmic curves are superficial and fortuitous. Any method therefore of evaluating disinfecting power based upon such a concept must prove misleading. Variations in resistance of individual cells and the distribution of such variations must be regarded as of fundamental importance in accounting for rates of death of microorganisms. PMID- 19872054 TI - MEMBRANE POTENTIALS AND COLLOIDAL BEHAVIOR. PMID- 19872055 TI - MEMBRANE POTENTIALS AND COLLOIDAL BEHAVIOR : REPLY TO THE NOTE BY PROFESSOR A. V. HILL. PMID- 19872056 TI - THE COMBINATION OF DEAMINIZED GELATIN WITH HYDROCHLORIC ACID. AB - 1. The analysis of isoelectric gelatin by the Van Slyke method indicates 0.00040 equivalents of amino N per gm. gelatin. 2. If deaminized gelatin is prepared without heating, the product contains less nitrogen than the original gelatin by an amount equal to 0.00040 equivalents N per gm. protein. 3. Deaminized gelatin, prepared either with or without heating, contains no amino nitrogen detectable with certainty by either the Van Slyke or the formol titration method. 4. The isoelectric point of deaminized gelatin prepared without heating is at pH 4.0. 5. The maximum combining capacity of this protein for HCl is 0.00044 equivalents per gm. 6. The maximum combining capacity of gelatin for HCl should be corrected to 0.00089 equivalents per gm. 7. The difference between these maximum combining capacities, 0.00045, is nearly equivalent to the loss in amino or total nitrogen occurring in the deaminizing reaction. 8. This equivalence constitutes a new indication that the combination of protein with acid is chemical combination. PMID- 19872057 TI - DIFFERENTIATION OF OXYHEMOGLOBINS BY MEANS OF MUTUAL SOLUBILITY TESTS. AB - 1. The rule of addition of solubilities is applicable to the differentiation of the oxyhemoglobins of not too closely related species. 2. The oxyhemoglobins of the horse, dog, rat, and guinea pig show differences when tested by this method. The oxyhemoglobins of the donkey and horse show a similarity which is best explained by the assumption of isomorphism. PMID- 19872058 TI - INFLUENCE OF LIGHT OF VERY LOW INTENSITY ON PHOTOTROPIC REACTIONS OF ANIMALS. AB - 1. The negative phototropism of certain land isopods was investigated over a large range of intensities, especially low ones. The responses were determined quantitatively by measuring the angle through which an animal turned away from a line perpendicular to the rays of light. 2. In the absence of light the undirected movements set up by obscure stimuli were such as to compensate each other statistically, the average path being a movement in the direction in which the animal was headed. 3. Over a large range of intensities (0.0026 m.c. up) the average turning is maximal, about 55 degrees (Oniscus). This maximal response is due to an anatomical peculiarity, in that the carapace cuts off the light on the eye after the animal has turned 50-60 degrees . This peculiarity probably accounts for specific differences among land isopods. Any light, therefore, which is strong enough to turn an animal through this maximal angle in a radial distance of 10 cm. will give results whose mean will be maximal. 4. Below 0.0026 m.c. the amount of angular deflection becomes less and less, in proportion to the logarithm of the intensity, until at 0.00003 m.c. the movements are the same as in darkness. 5. This proportionality between amount of turning and the logarithm of the intensity indicates the photochemical nature of phototropism on the basis of Hecht's work with Mya. As a result, Loeb's theory of phototropism may then be stated in the mathematical form See PDF for Equation in which I(1) and I(2) are the two intensities, E(1) and E(2), their respective effects, and R, the muscular action set up by the difference in photochemical effect on the two sides. PMID- 19872059 TI - OBSERVATIONS ON THE TRANSPORT OF CARBON DIOXIDE IN THE BLOOD OF SOME MARINE INVERTEBRATES. AB - Although the results we have recorded merely serve to indicate the possibilities of this interesting field of investigation, we have sufficient data to enable us to draw certain general conclusions. In the first place it is evident that the bloods of the more highly developed marine invertebrates, such as the active Crustacia and the Cephalopods, are specially adapted for the carriage of carbon dioxide. The quantity of carbon dioxide taken up by the blood of Maia, Palinurus, or Octopus at any given tension of the gas is, in general, about twice or three times as great as that which is taken up by sea water under the same conditions. On the other hand, the blood of a slow, creeping form, such as Aplysia, or of a sessile animal such as the ascidian Phallusia shows no more adaptation for the carriage of carbon dioxide than does sea water. But our estimations of the CO(2) content of the blood as it circulates in the bodies of these more active invertebrates show that the conditions of transport of this gas differ considerably in some respects from those which obtain in mammals. For the invertebrate blood in the body contains only a relatively small quantity of carbon dioxide, averaging in the forms we examined from 3 to 10 cc. per 100 cc. of blood. This forms a marked contrast with the condition found in mammals where even the arterial blood contains about 50 cc. of CO(2) per 100 cc. of blood. The invertebrate, therefore, works at a very low CO(2) tension. There is a twofold significance in this circumstance. In the first place, it means that only the first portion of the carbon dioxide dissociation curve is in use in the respiratory mechanism. Now an inspection of our curves will show that at these low carbon dioxide tensions the dissociation curves tend to be steeper than at higher tensions. As we intend to show in a later paper it can be proved mathematically that, other things being equal, a blood with a carbon dissociation curve of moderate steepness, i.e. one in which the carbon dioxide content of the blood increases fairly rapidly with increase of carbon dioxide tension, is a more efficient carrier of the gas from the tissues to a respiratory surface than a blood in which the dissociation curve is either steeper or flatter. It would seem as if the active invertebrates avoid the use of too flat a part of their CO(2) dissociation curves by working over the initial steeper portion. Furthermore, it is seen that over the range of this initial steep portion of the curves the changes of reaction produced by the uptake of carbon dioxide are much smaller than at higher tensions of the gas; for these initial portions of the curves are more nearly parallel to the lines of constant reaction calculated for a temperature of 15 degrees C. according to Hasselbalch's method (10) on the assumption that the whole of the combined CO(2) is in the form of sodium bicarbonate. It is evident also that on this assumption the hydrogen ion concentration of the blood of invertebrates (with the exception of the tunicates) would appear to be practically the same as that of the warm-blooded vertebrates-a conclusion confirmed by the direct measurements of Quagliariello (9). On the other hand, our measurements do not lend support to the idea put forward by Collip (4) that in order to maintain an appropriate faintly alkaline reaction an invertebrate needs to retain carbon dioxide in its blood at a comparatively high tension. This idea was based on the observation that at comparatively high CO(2) tensions the blood of invertebrates contains considerably more sodium bicarbonate than does sea water. But our curves show that this is no longer true at the lower values of carbon dioxide tension, the amount of sodium bicarbonate falling off more rapidly in the blood than in the sea water with diminution of the carbon dioxide tension so that in order to maintain an appropriate reaction in the blood only a comparatively small tension of CO(2) is required. The largest amount of carbon dioxide that we found present in the circulating blood of any of the types examined was 9.7 cc. per 100 cc. of blood in the case of Maia, and in most cases the amount was considerably less. But even this lowest value corresponds to a tension of CO(2) of only about 3 mm., so that the tension gradient across the gill membrane must be even less than this. We would emphasize rather the circumstances that as the portion of the dissociation curve over which the reaction is approximately constant is of but small extent, it is necessary that in an active form like Octopus the carbon dioxide produced should be removed rapidly lest an accumulation of it should cause the limits of normal reaction to be exceeded; and this need is correlated with the extreme efficiency of the respiratory apparatus in this animal. It is interesting to notice that the mammal which, in order to obtain an appropriate reaction in the blood, has to work at relatively high carbon dioxide tensions where the dissociation curve is comparatively flat, secures a steeper physiological CO(2) dissociation curve in the body, and with it a more efficient carriage of carbon dioxide and a more constant reaction in the circulating fluid, in virtue of the effect of oxygenation on the carbon dioxide-combining power of its blood (3, 6). Returning now to the consideration of the actual form of the dissociation curves we have obtained-it is a significant fact that it is in those forms such as Maia, Palinurus, and Octopus whose bloods are rich in proteins-particularly hemocyanine that the initial steep portion of the curve is observed. This suggests that in these forms the blood proteins act as weak acids and expel carbon dioxide from the blood at the low tensions which include the physiological range, just as in vertebrates the hemoglobin similarly displaces carbonic acid from its combination with alkali metal. On the other hand the coelomic fluid of Aplysia contains no pigment and only 0.00672 per cent of protein nitrogen (Bottazzi (11)) and shows no initial rapidly ascending portion of the CO(2) dissociation curve. This is supported by the observation of Quagliariello (9) that the acid-neutralising power of the blood of an invertebrate is roughly proportional to its protein content. It seems as if the proteins of invertebrate blood like the blood proteins of vertebrates, exist in the form of sodium salts which are capable of giving up sodium for the transport of carbon dioxide as sodium bicarbonate. That this is so in the case of hemocyanine follows from the fact that the isoelectric point of this pigment occurs at a hydrogen ion concentration of 2.12 x 10(-5)N, i.e. at a pH of 4.67 (Quagliariello (12)) so that in the alkaline blood of the invertebrates possessing it, hemocyanine will act as a weak acid. It is probable that the initial steep portion of the carbon dioxide dissociation curves which we have found to be of such importance in the respiration physiology of Octopus, Palinurus, and Maia is produced by the competition of this acid with carbonic acid for the available sodium of the blood. PMID- 19872060 TI - EXPERIMENTS ON TOLERATION OF TEMPERATURE BY DROSOPHILA. AB - 1. Most wild stocks of Drosophila melanogaster can be bred indefinitely on banana agar at a temperature of 31 degrees C. There is no relation between the geographical origin of these stocks and their ability to tolerate this temperature. 2. A single wild stock has been found which will breed for only one generation at temperatures above 29 degrees C. The offspring hatched at 31 degrees C. will breed normally at 24 degrees C. This difference from other wild stocks is apparently genetic, but its genetic basis has not yet been worked out. 3. The mutant stocks of D. melanogaster tested by us will breed for only one generation at 31 degrees C. and their offspring at this temperature are also fertile at 24 degrees C. This condition is apparently a physiological effect of the presence of any of the mutant genes in a homozygous condition. 4. Similar tests indicate that wild stocks of D. virilis and Chymomyza procnemis will breed at 31 degrees C., while D. simulans, D. immigrans, and D. funebris will not. The last two species are northern forms not commonly found in the tropics. 5. Both male and female flies from mutant stocks hatched at 31 degrees C. produce offspring at this temperature if mated to flies hatched at 24 degrees C. Their germ cells are therefore capable of development, and the cause of their failure to develop at 31 degrees C. when inbred must lie either in the failure of the germ cells to reach each other or in the fertilization process itself. PMID- 19872061 TI - ELECTROPHORESIS OF BACTERIA AS INFLUENCED BY HYDROGEN ION CONCENTRATION AND THE PRESENCE OF SODIUM AND CALCIUM SALTS. AB - 1. We have confirmed the results of earlier workers particularly of Northrop and De Kruif in regard to the following points: (a) the general tendency of the bacterial cell when suspended in distilled water near the zone of neutrality to move toward the anode of an electrical field; (b) the fact that the migration of bacterial cells in the electrical field is a function of the reaction of the menstruum. The curve obtained by plotting velocity of migration against pH passes through an isoelectric point at about pH 3.0, at greater acidity the direction of migration becomes reversed (toward the cathode) and in still more acid solution (pH = 1.0) again disappears; while at reactions less acid than pH 3.0 the velocity is toward the anode and increases with increasing alkalinity; (c) the fact that neutral salts depress the velocity of migration, calcium salts being much more effective than sodium salts of the same concentration. 2. We further find: (a) that on the extreme alkaline side of the curve of velocity of migration plotted against pH a maximum value is reached at about pH 10 with a fall at about pH 12.0 which in many experiments reaches an isopotential point; (b) that the depressing effect of salts is accompanied by a general shifting of the curve of migration velocity so that a maximum velocity (of course absolutely less than that manifest in the absence of salts) appears at about pH 7.0 and an abolition of velocity at pH 9.0 to 10.0; (c) that an apparent "antagonistic" effect is indicated between CaCl(2) and NaCl, the presence of a certain concentration of the latter salt diminishing to a slight but definite degree the depressing effect produced by the former; (d) that heat-killed bacterial cells exhibit essentially the same curve of migration velocity as that of the living cells; (e) that bacterial spores exhibit the same general curve of migration velocity as vegetative cells, although the actual velocity is apparently slightly less. 3. All of the observed phenomena appear to be in accord with the assumption that marked differences in dielectric constants did not appear under the conditions studied and if this assumption be granted the results are in accord with the fundamental postulates of the Donnan equilibrium as applied to the explanation of the origin of potential difference between a bacterial cell and its enveloping menstruum. It is possible but not at all certain that the phenomenon of antagonism may require the introduction of additional assumptions for its explanation. Professor Donnan and other investigators have clearly understood the importance of applying the concept of membrane equilibria in the elucidation of physiological phenomena. Our findings add to the numerous vindications favoring this view and emphasize the importance of further study of membrane equilibria in bacterial suspensions. We have pointed out that certain potential differences between bacteria and their menstrua are apparently associated with some of the phenomena of viability. Viability and potential differences may, however, under certain conditions vary quite independently as evidenced by the fact that normal rates of migration are demonstrable after the cells have been killed by heat. Thus, considerable caution must be exercised in relating the existence of these charges to the metabolism of the cell. PMID- 19872062 TI - CONDUCTIVITY TITRATION OF GELATIN SOLUTIONS WITH ACIDS. AB - Titrations have been made, by the conductivity method, of gelatin solutions with hydrochloric and sulphuric acids. The results indicate an end-point at about 8.6 cc. of N/10 acid per gm. of gelatin, or a combining weight of about 1,160. These results are in fair agreement with those previously obtained by the hydrogen electrode method. Better agreement between the two methods was found in the case of deaminized gelatin. The data are in accord with a purely chemical conception of the combination between protein and acid. PMID- 19872063 TI - THEORY OF REGENERATION BASED ON MASS ACTION. II. AB - 1. Quantitative proof is furnished that all the material available for shoot and root formation in an isolated leaf of Bryophyllum calycinum flows to those notches where through the influence of gravity or by a more abundant supply of water growth is accelerated. As soon as the acceleration of growth in these notches commences, the growth of shoots and roots in the other notches which may already have started ceases. 2. It had been shown in a preceding paper that the regeneration of an isolated piece of stem may be and frequently is in the beginning not markedly polar, but that after some time the growth of all the roots except those at the base and of all the shoots except those at the apex is suppressed. This analogy with the behavior of regeneration in a leaf in which the growth in one set of notches is accelerated, suggests that in an isolated stem a more rapid growth is favored at the extreme ends (probably by a block of the sap flow at the extreme ends) and that when this happens the total flow of ascending sap goes to the most apical buds and the total flow of the descending sap goes to the most basal roots. As soon as this occurs, the growth of the other roots and shoots is suppressed. PMID- 19872064 TI - THE INFLUENCE OF THE CHEMICAL NATURE OF SOLID PARTICLES ON THEIR CATAPHORETIC P.D. IN AQUEOUS SOLUTIONS. AB - 1. The effect of eight salts, NaCl, Na(2)SO(4), Na(4)Fe(CN)(6), CaCl(2), LaCl(3), ThCl(4), and basic and acid fuchsin on the cataphoretic P.D. between solid particles and aqueous solutions was measured near the point of neutrality of water (pH 5.8). It was found that without the addition of electrolyte the cataphoretic P.D. between particles and water is very minute near the point of neutrality (pH 5.8), often less than 10 millivolts, if care is taken that the solutions are free from impurities. Particles which in the absence of salts have a positive charge in water near the point of neutrality (pH 5.8) are termed positive colloids and particles which have a negative charge under these conditions are termed negative colloids. 2. If care is taken that the addition of the salt does not change the hydrogen ion concentration of the solution (which in these experiments was generally pH 5.8) it can be said in general, that as long as the concentration of salts is not too high, the anions of the salt have the tendency to make the particles more negative (or less positive) and that cations have the opposite effect; and that both effects increase with the increasing valency of the ions. As soon as a maximal P.D. is reached, which varies for each salt and for each type of particles, a further addition of salt depresses the P.D. again. Aside from this general tendency the effects of salts on the P.D. are typically different for positive and negative colloids. 3. Negative colloids (collodion, mastic, Acheson's graphite, gold, and metal proteinates) are rendered more negative by low concentrations of salts with monovalent cation (e.g. Na) the higher the valency of the anion, though the difference in the maximal P.D. is slight for the monovalent Cl and the tetravalent Fe(CN)(6) ions. Low concentrations of CaCl(2) also make negative colloids more negative but the maximal P.D. is less than for NaCl; even LaCl(3) increases the P.D. of negative particles slightly in low concentrations. ThCl(4) and basic fuchsin, however, seem to make the negative particles positive even in very low concentrations. 4. Positive colloids (ferric hydroxide, calcium oxalate, casein chloride-the latter at pH 4.0) are practically not affected by NaCl, are rendered slightly negative by high concentrations of Na(2)SO(4), and are rendered more negative by Na(4)Fe(CN)(6) and acid dyes. Low concentrations of CaCl(2) and LaCl(3) increase the positive charge of the particles until a maximum is reached after which the addition of more salt depresses the P.D. again. 5. It is shown that alkalies (NaOH) act on the cataphoretic P.D. of both negative and positive particles as Na(4)Fe(CN)(6) does at the point of neutrality. 6. Low concentrations of HCl raise the cataphoretic P.D. of particles of collodion, mastic, graphite, and gold until a maximum is reached, after which the P.D. is depressed by a further increase in the concentration of the acid. No reversal in the sign of charge of the particle occurs in the case of collodion, while if a reversal occurs in the case of mastic, gold, and graphite, the P.D. is never more than a few millivolts. When HCl changes the chemical nature of the colloid, e.g. when HCl is added to particles of amphoteric electrolytes like sodium gelatinate, a marked reversal will occur, on account of the transformation of the metal proteinate into a protein-acid salt. 7. A real reversal in the sign of charge of positive particles occurs, however, at neutrality if Na(4)Fe(CN)(6) or an acid dye is added; and in the case of negative colloids when low concentrations of basic dyes or minute traces of ThCl(4) are added. 8. Flocculation of the suspensions by salts occurs when the cataphoretic P.D. reaches a critical value which is about 14 millivolts for particles of graphite, gold, or mastic or denatured egg albumin; while for collodion particles it was about 16 millivolts. A critical P.D. of about 15 millivolts was also observed by Northrop and De Kruif for the flocculation of certain bacteria. PMID- 19872065 TI - THE KINETICS OF TRYPSIN DIGESTION : I. EXPERIMENTAL EVIDENCE CONCERNING THE EXISTENCE OF AN INTERMEDIATE COMPOUND. AB - 1. The rate of hydrolysis of a casein solution by trypsin is not affected by the addition of gelatin. The trypsin, therefore, is not combined with the gelatin unless there is a separate enzyme for casein and for gelatin. 2. The presence of casein protects the gelatin-splitting power of trypsin from heat inactivation, and the presence of gelatin protects the casein-splitting power from heat inactivation. 3. It does not seem possible to account for both the above results by the assumption of an intermediate compound between enzyme and substrate, since, in order to account for the first result, a different enzyme must be assumed for each protein, while, to account for the second result, it must be assumed that the same enzyme attacks both. PMID- 19872066 TI - THE KINETICS OF SENESCENCE. AB - The course of decline of vitality with age due to the process of senescence, when not complicated by the process of growth, follows a simple exponential law; that is the degree of vitality or of senescence (defining vitality as the reciprocal of senescence) at any moment is, regardless of age, a constant percentage of the degree of vitality or senescence of the preceding moment. This exponential law is the same as the law of monomolecular change in chemistry. During the actively growing period of life the index of vitality rises, due to the process of growth and the course of vitality in the case when the growing period is included in the vitality curve, follows a rising and falling course. This rising and falling course may often be represented by an equation containing two exponential terms which is practically the equation used to represent the course of accumulation and disappearance of a substance as the result of two simultaneous consecutive monomolecular chemical reactions. PMID- 19872067 TI - ISOELECTRIC POINTS FOR THE MYCELIUM OF FUNGI. AB - 1. Mycelium of Rhizopus nigricans when stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.0. 2. When grown on potato dextrose agar the reaction of which was varied with phosphoric acid the extent of colony growth of Rhizopus nigricans plotted against the initial Sorensen value of the agar produced a double maximum curve with the minimum between the two maxima at initial pH 5.2. 3. When grown in potato dextrose broth the reaction of which was varied with phosphoric acid the dry matter produced by Rhizopus nigricans plotted against the Sorensen value of the broth produced a double maximum curve with the minimum between the two maxima at initial pH 5.2 or average pH 4.9. 4. Mycelium of Rhizopus nigricans placed in buffer mixtures of 0.01 M phosphoric acid and sodium hydroxide of pH 4.1 to 6.3, changed the reaction in most cases toward greater alkalinity. 5. Mycelium of Fusarium lycopersici stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.5. PMID- 19872068 TI - LUMIMESCENCE IN PELAGIA NOCTILUCA. AB - 1. Ca and K condition the irritability of Pelagia both in regard to rhythmical contractions and general luminescence. If either ion is omitted from the solution conduction of stimuli for pulsations and luminescence does not occur, although local responses still persist. 2. When Mg is omitted from the solution, Pelagia shows hyper-irritability with respect to rhythmical contraction and general luminescence. This is referable to the unantagonized action of K and Ca ions. 3. Exposure to the carbon arc suppresses general luminescence, the effect depending upon the quantity of light i.e. intensity x time of exposure. 4. The luminescent material secreted by Pelagia is inactive in sea water, but when put into salt solutions is activated by some of them. The efficiency of the salts, measured by brightness of light, is in the following order: MgSO(4), K(2)SO(4), Na(3) citrate, KCl, BaCl(2), SrCl(2), CaCl(2), and LiCl while NaCl and MgCl(2) act as inhibitors. 5. Acidity inhibits the reaction, alkalinity promotes it. NH(4)OH in concentrations 0.27 N to 0.9 N causes luminescence for 10 minutes at 20 degrees . 6. The average temperature coefficient for the reaction of the luminescent substance when activated by ammonia or MgSO(4) is 2.18 for a temperature interval of 10 degrees C. 7. The luminescence reaction cannot be the result of cytolysis, because (a) raising the temperature of sea water in which luminous material is immersed does not cause luminescence, although sufficient to produce cytolysis. (b) The salt solutions used in our experiments to cause luminescence, do not act cytolytically on cells in general. PMID- 19872069 TI - THE NERVOUS MECHANISM OF COORDINATION IN THE CRINOID, ANTEDON ROSACEUS. AB - 1. Stimulation causes Antedon to swim by means of alternate oral bending and dorsal stroke of the arms. Two arms of a given ray move alternately so that while one is executing the aboral stroke its mate is flexing ventrally. This implies reciprocal inhibition. 2. Recriprocal inhibition between the two arms of an isolated ray can be abolished by the use of either strychnine or nicotine. 3. Coordination between the rays is referable to the conducting properties of the nervous pentagon which connects the five rays. In this system an impulse loses in effectiveness as it passes from the point of origin. 4. When Antedon is made to rest oral face down on the floor of an aquarium, oral flexion of all the rays, swimming movements, and righting result. Antedon is therefore negatively stereotropic with reference to its ventral side. 5. Excitation of the dorsal cirri results in aboral bending of all the rays. Stimulation of the cirri inhibits ventral flexion to the extent of preventing righting movements while on the other hand stimulation of the ventral surface inhibits the grasp reflex of the cirri. Thus oral and aboral sides of Antedon exhibit dynamic symmetry although structurally dissimilar. PMID- 19872070 TI - HYDROGEN ION CONCENTRATIONS WITHIN THE ALIMENTARY TRACT OF INSECTS. AB - Larvae of Psychoda and of Chironomus (diptera) maintained in solutions of appropriate indicators show that the typical acidities (pH) prevailing within the several regions of the digestive tract are: esophagus 7.1; cardiac chamber 6.2; mesenteron 7.5; the latter being functionally an intestine. The acidity of the hindgut, pH 6.4, is due to the discharge of the malphigian tubules. PMID- 19872071 TI - THE EFFECT OF LABORATORY AGE UPON THE PHOTOTROPIC REACTIONS OF LIMULUS. PMID- 19872072 TI - THE EFFECT OF PHOSPHATES ON RESPIRATION. AB - Phosphate accelerates both aerobic and anaerobic respiration. The acceleration almost disappears when the plant dies (in phosphate solution) but subsequently becomes greater than in life. PMID- 19872073 TI - HYDROPHILIC AND HYDROPHOBIC COLLOIDS AND THE INFLUENCE OF ELECTROLYTES ON MEMBRANE POTENTIALS AND CATAPHORETIC POTENTIALS. AB - 1. In order to be able to compare the effects of electrolytes on membrane potentials and cataphoretic potentials it seems necessary to distinguish between the charging and depressing effect of electrolytes on these potentials. Only low concentrations of acids and alkalies have a charging effect on the membrane potentials of proteins, while low concentrations of neutral salts have only a depressing effect; in the case of the cataphoretic potentials, low concentrations of salts have a charging effect as have also low concentrations of alkalies and in some cases low concentrations of acids. This difference finds its explanation in the difference of the origin of the two potentials and there can therefore be no common theory for the charging effect of electrolytes in the two cases. 2. There exists, however, an analogy in the depressing action of electrolytes on the two types of potentials inasmuch when the maximal P.D. is reached, all three kinds of electrolytes, acids, alkalies, and neutral salts, have a depressing effect on both types of potentials (taking into due consideration the effect of changes in the hydrogen ion concentration). 3. This depressing effect is adequately explained for the membrane potentials of protein solutions and protein gels on the basis of the Donnan equilibrium, and the question arises whether the same explanation may also hold for the cataphoretic potentials. 4. The active ion in the depressing action of electrolytes on membrane potentials as well as on cataphoretic potentials has the opposite sign of charge from that of the colloidal particle. It had been shown before that only the valency but not the chemical nature of the active ion determines the depressing effect in the case of membrane potentials and it is shown in this paper that the same is true for the cataphoretic potentials of particles of collodion, mastic, Acheson's graphite, and denatured egg albumin. 5. It is shown that the same valency rule holds also for the effect of acids on the cataphoretic potentials of collodion particles coated with gelatin, and that the ratio of the effect of dibasic to that of mono basic acids is approximately 0.66, as Donnan's theory of membrane potentials would demand. 6. If we have a right to conclude from the validity of the valency rule for cataphoretic potentials that the depressing effect of electrolytes on the cataphoretic P.D. is determined by the Donnan equilibrium, we can understand the analogy between the depressing action of electrolytes on membrane potentials of hydrophilic colloids and on the cataphoretic potentials of hydrophobic colloids. We can also understand the analogy between the influence of electrolytes on the precipitation of hydrophobic colloids and on the depression of the values of all those properties of hydrophilic colloids which depend on the Donnan equilibrium, since the precipitation of hydrophobic colloids occurs when the cataphoretic P.D. is depressed below a critical value. PMID- 19872074 TI - THE RATE OF GROWTH OF THE DAIRY COW : V. EXTRAUTERINE GROWTH IN LINEAR DIMENSIONS. AB - Barring fluctuations due to the cyclic phenomena, the extrauterine course of growth in linear dimensions and in weight of the dairy cow follows an exponential law having the same form as the law representing the course of monomolecular change in chemistry. This suggests the interpretation that the general course of growth is limited by a monomolecular chemical process, and that the cyclic phenomena are due to subsidiary processes in the fundamentally exponential course of growth. The fact that growth follows or tends to follow an exponential course may be stated more simply as follows: if the unit of time is taken sufficiently large so that fluctuations due to the cyclic phenomena are balanced or eliminated, then the amount of growth made during the given unit of time at any age tends to be a constant percentage of the growth made during the preceding unit of time. Thus, the growth in height at withers made during any year is about 34 per cent of the growth made during the preceding year. Similarly the growth in weight made during any year is about 56 per cent of the growth in weight made during the preceding year. This is in accordance with expectations if it is assumed that each animal begins life with a definite endowment of limiting substance necessary for the process of growth, and that this endowment is used up at a constant rate (or percentage) of itself. PMID- 19872075 TI - A TEST FOR DIFFUSIBLE IONS : I. THE IONIC NATURE OF TRYPSIN. AB - 1. The Donnan equilibrium furnishes a test for the ionic nature of any diffusible substance, since the ratio of the concentration of any ion on the two sides of a membrane must be equal to the ratio of the concentrations of any other ion of the same sign and valence, whereas a non-ionic substance would be equally distributed on both sides. 2. The distribution of trypsin inside and outside of gelatin particles has been compared to the distribution of hydrogen and chloride ions under the same conditions. 3. The ratio of the trypsin concentration in the gelatin to the concentration in the outside liquid is equal to the ratio of the hydrogen ion under the same conditions and to the reciprocal of the chloride ion ratio. 4. This result was obtained between pH 2.0 and 10.2. At pH 10.2 the trypsin is equally distributed and on the akaline side of 10.2 the ratio is directly equal to the chloride ratio. 5. Trypsin is therefore a positive monovalent ion in solutions of pH 10 to 2. It is probably isoelectric at 10.2 and a monovalent negative ion on the alkaline side of 10.2 6. Trypsin must also be a strong base since there is no evidence of any undissociated form on the acid side of pH 10.2. PMID- 19872076 TI - IONIC THEORY OF ACTIVITY OF NERVE CENTERS AND OF PROPAGATION OF NERVE IMPULSE. PMID- 19872077 TI - INTENSITY DISCRIMINATION AND THE STATIONARY STATE. AB - 1. A method of experimentation is described which enables one to record objectively and quantitatively the discrimination by Mya between two intensities of illumination to which it is successively exposed. The indicator for this discrimination is a response at a given reaction time. 2. From the data so obtained it is found that the difference, DeltaI, between the two intensities bears no constant relation to the initial intensity, I. Instead, the ratio See PDF for Equation varies in a consistent manner with I. As the latter increases, the ratio decreases to a certain point, after which it increases. 3. The data are analyzed in terms of the photochemical mechanism previously proposed for the sensitivity of Mya to light. It is shown that for the animal to discriminate by means of a given reaction between one intensity and another, the transition from one to the other must be accompanied by the decomposition of a constant amount of photosensitive substance in the sense organ. 4. A mathematical treatment of the behavior of the photochemical mechanism shows not only that the ratio See PDF for Equation cannot be constant as required by the Weber-Fechner law, but that it must vary in the way in which it does. The behavior of Mya under these conditions, therefore, supports the validity of the hypothetical physicochemical mechanism suggested for its sensitivity. PMID- 19872078 TI - A MATHEMATICAL TREATMENT OF THE ELECTRICAL CONDUCTIVITY OF COLLOIDS AND CELL SUSPENSIONS. PMID- 19872079 TI - TROPISTIC REACTIONS OF CERIANTHUS MEMBRANACEUS. AB - 1. Cerianthus shows stereotropism and if fed regularly will remain indefinitely in glass tubes. The animal retains turgor only so long as the entire surface of the body is in contact with the glass. 2. Cerianthus is positively geotropic as regards the foot and body. It will work upward into a glass tube suspended at an angle of 35 degrees as a result of stereotropism, but if the tube is raised to an angle of 45 degrees the foot turns back and the animal reverses its position in the tube so that foot is down, head, up. Thus at an angle of 45 degrees stereotropism and geotropism very nearly balance each other. 3. Light increases the muscle tone of Cerianthus; this results in positive phototropism. I x t = K. where I is the intensity of the light, t is exposure time, and K, a constant, = 0.46. Where reaction time is considered, I (t + k) = K, in which I is intensity of light, t is reaction time, k = 0.25, and K = 28.29. The two equations prove the operation of the Bunsen-Roscoe law. PMID- 19872080 TI - THE REACTION OF CERIANTHUS TO TWO SOURCES OF LIGHT. AB - 1. In case Cerianthus is acted upon by two lights of unequal intensities the relation between the angle turned and the ratio between the intensities of the two lights is mathematically expressed by the equation log(10) See PDF for Equation tan a, in which See PDF for Equation is the ratio of the two lights, a is the angle turned from the neutral position, and K = 0.615. 2. According to published data from experiments on other animals, the relation between the angle turned and the ratio between the intensities of the two lights may be expressed by the same equation. PMID- 19872081 TI - LUMINESCENCE IN MNEMIOPSIS. AB - 1. In the dark adapted Mnemiopsis, mechanical stimulation causes luminescence along the eight rows of paddle plates. The tactile receptors for this reaction lie only in the paddle plate rows, and are connected only longitudinally along these rows. 2. The tactile receptors for ciliary and muscular movement are distributed generally over the surface and are connected by a nerve net. 3. Luminescence may occur at 3 degrees C. provided the animal has been kept sufficiently long at that temperature. Ciliary action goes on at - 0.6 degrees C. 4. Luminescent paper made by spreading the luminescent secretion of Mnemiopsis on filter paper, yields the following effects. The paper shows luminescence in solutions of K(2)SO(4), KCl, MgSO(4), SrCl(2), CaCl(2); no luminescence in NaCl, MgCl(2). Changes in pH value of salt solutions between pH 6 and 8 do not affect the phenomenon. Illumination of the paper with strong light for longer time than necessary to suppress luminescence in the living animal has no effect on the subsequent luminescence of the paper. Hence in the animal, light affects luminescence through the photoreceptor system; the nervous system carries the impulse to the luminescent organs. 5. The power of luminescence of the animal is suppressed by sufficiently intense light, the relation between the intensity and the time requisite being expressed by the equation for the Bunsen-Roscoe photochemical law, namely, I . t = K. 6. It is suggested that the reaction scheme involved in luminescence is of the following form See PDF for Equation in which A is the luminescent substance in the resting, dark adapted animal, L is the light giving decomposition product, and D is a product which does not yield light. 7. The luminescent substance receives double innervation and the character of the decomposition is determined by the type of nerve fiber stimulated. PMID- 19872082 TI - A CELL FOR THE MEASUREMENT OF CATAPHORESIS OF ULTRAMICROSCOPIC PARTICLES. PMID- 19872083 TI - THE KINETICS OF TRYPSIN DIGESTION : II. CONDITIONS UNDER WHICH THE REACTION IS MONOMOLECULAR. AB - 1. The kinetics of enzyme reactions diverge more or less from the simple mass action expression for a monomolecular reaction. There is good reason to believe that these discrepancies are due to other secondary reactions which also agree with the law of mass action. Attempts to incorporate all these reactions in one equation, however, are unsatisfactory owing to the complexity of the relations involved. 2. It is possible, however, to regulate conditions experimentally so that these secondary reactions are reduced to a minimum. This has been done in the case of trypsin digestion by working at a low temperature, which prevents inactivation of the trypsin, by using a large amount of trypsin, which prevents the inhibiting effect of the products from becoming noticeable, and by using the disappearance of the protein as the indicator which obviates the complicating effects of the consecutive reactions. 3. Under these conditions the hydrolysis, for any initial concentration of casein is accurately represented by the monomolecular formula, See PDF for Equation The effect of variations in the initial trypsin concentration are also correctly predicted. 4. If the initial casein concentration is varied, however, the value of the constant changes for each casein concentration, becoming less as the casein increases and eventually becoming nearly inversely proportional to the casein concentration. It is pointed out that this cannot be due to a compound between enzyme and casein, nor to the viscosity, but is probably owing to an equilibrium between the casein and water, in which the casein can be replaced by the first cleavage products. This is corroborated by the fact that if the casein is dissolved in a freshly prepared solution of digested casein, the anomalous effect of the substrate concentration disappears and the reaction is typically monomolecular in every respect. A solution of digested casein which has been in prolonged contact with trypsin does not have this effect. 5. It is pointed out that the various equations that have been proposed to account for the enzyme reactions on the basis of a compound between the enzyme and substrate could be applied equally well on the basis of a compound between water and the substrate which is attacked by the enzyme. PMID- 19872084 TI - THE KINETICS OF TRYPSIN DIGESTION : III. THE COURSE OF THE REACTION WITH CONSTANT SUBSTRATE UNDER CONDITIONS CAUSING INACTIVATION OF THE ENZYME. AB - 1. A study has been made of the rate of hydrolysis of concentrated gelatin solutions at a high temperature and with a large amount of trypsin. 2. Under these conditions the substrate concentration may be considered constant and the only variable is the decrease in the amount of trypsin owing to inactivation. 3. The theory based on the mass law predicts that under these conditions (a) the rate at any time will be proportional to the concentration of trypsin at that time; (b) the reaction should approximate a monomolecular one if the total hydrolysis observed is taken as the amount of substrate available; (c) that the velocity constant calculated in this way should agree with the constant for the decomposition of the enzyme and that it should be independent of the concentration of enzyme instead of proportional to it as is usually the case; and (d) that the total amount of substrate decomposed should be proportional to the amount of trypsin added at the beginning instead of independent of it. These results have been obtained experimentally. PMID- 19872085 TI - THE KINETICS OF TRYPSIN DIGESTION : IV. THE COURSE OF THE REACTION WHEN BOTH SUBSTRATE AND ENZYME CONCENTRATIONS ARE DECREASING. AB - The rate of hydrolysis of edestin by trypsin at 40 degrees and in the presence of 1 M NaCl has been studied. Under these conditions the enzyme is rapidly inactivated and the equation for the reaction may be written See PDF for Equation in which E(t) is the concentration of enzyme during the interval (T(1)-T(2)). This equation has been tested by determining the enzyme concentration at various times during the reaction and substituting these values in the above equation. The experimental results agree with this formula when the initial enzyme or edestin concentrations are varied. No anomalous results of varying substrate concentrations are apparent. It can further be assumed as a first approximation that the enzyme is decomposing monomolecularly and the equation can then be written See PDF for Equation This equation is also satisfactory provided high enzyme concentrations and low edestin concentrations are used. With high concentrations of edestin and low trypsin the effects of the products of the reaction on the enzyme become too large to be neglected and the formula no longer holds. PMID- 19872086 TI - ON THE DIFFUSIBILITY OF THE CALCIUM OF BLOOD SERUM THROUGH COLLODION MEMBRANES : THE EFFECT OF SODIUM CHLORIDE AND CHANGES IN HYDROGEN ION CONCENTRATION. AB - 1. Serum calcium is completely diffusible through collodion membranes in 0.8 per cent NaCl at a pH of 7.4. 2. About 55 to 75 per cent of serum Ca is diffusible through collodion membranes in distilled water at a pH of 7.4. 3. Serum Ca is completely diffusible when dialyzed against HCl at a pH of 2.5. PMID- 19872087 TI - THE ISOELECTRIC POINT OF GELATIN AT 40 degrees C. AB - Measurements have been made at 40 degrees C. of the osmotic pressure and viscosity of 1 per cent gelatin solutions containing varying amounts of hydrochloric acid or sodium hydroxide. Each property was found to exhibit a decided minimum near pH 4.7. In the osmotic pressure experiments the pH of the inside solutions was greater than that of the outside solutions at pH values below 4.7, while it was less than that of the outside solutions at values above pH 4.7. These results indicate that gelatin at 40 degrees C. retains its isoelectric point at about pH 4.7. PMID- 19872088 TI - THEORY OF REGENERATION BASED ON MASS RELATION : III. FURTHER EXPERIMENTS ON THE CAUSE OF THE POLAR CHARACTER OF REGENERATION. AB - 1. Small stems with one large leaf in the middle produce shoots and roots chiefly at the expense of material sent into the stem by the leaf. Since the sap of the leaf can cause the formation of roots and shoots in the same notch of the leaf, it is difficult to assume that the polar character of the regeneration in the stem is due to a chemical difference in the ascending and descending sap sent by the leaf into the stem. 2. When the ascending sap sent by a leaf into the stem is caused with the aid of gravity to reach those tissues of the stem from which roots are formed, an abundant root formation is produced by the ascending sap. 3. These two observations in connection with a fact already published in a preceding paper support the idea that the polar character of regeneration in a stem of Bryophyllum is not due to any of the chemical differences between the ascending and descending sap but to a difference in the nature of the tissues or anlagen which are primarily reached by the ascending and descending sap. PMID- 19872089 TI - THE ULTIMATE UNITS IN PROTEIN SOLUTIONS AND THE CHANGES WHICH ACCOMPANY THE PROCESS OF SOLUTION OF PROTEINS. AB - 1. The experiments show that suspensions of finely divided particles of insoluble proteins incapable of swelling in acid (denatured egg albumin, casein trichloroacetate, sulfate, etc.) raise the viscosity of the suspension but little and that the influence of acid on the viscosity is negligible. 2. The same is true for solutions of certain genuine proteins such as genuine crystalline egg albumin. 3. In contrast with these are proteins which swell in acid. It can be shown that where acid swelling of particles occurs, the viscosity is of a higher order of magnitude than where the swelling of particles is impossible and that the influence of acid on viscosity runs in these cases parallel to the influence of acid on swelling. This is shown to be the case for casein in HCl. 4. It is shown that the swelling of the powdered particles which determines the high order of viscosity varies according to the theory of membrane equilibria. 5. These results are used to ascertain with the aid of viscosity measurements whether the ultimate units of genuine protein in solutions are aggregates large enough to give rise to a Donnan equilibrium; or whether they consist of particles below this limit; and in what porportion the two kinds of units are contained in the solution. 6. It is found on the basis of viscosity measurements that when 1 gm. of isoelectric casein is dissolved in HCl so that the solution has a pH of 2.45, more than one-half of 1 gm. of casein must exist as units too small to give rise to a Donnan equilibrium, while the rest must exist in units still capable of undergoing swelling in acid. PMID- 19872090 TI - THE MECHANISM OF VITAL STAINING WITH BASIC DYES. AB - 1. Solutions containing NH(4)OH and NaOH, and CO(2) and HCl may be used to produce various combinations of extracellular and intracellular reactions in starfish eggs, Gonionemus, and Nitella cells. 2. Staining by basic dyes is, with a constant intracellular reaction, favored by increased extracellular alkalinity. With a constant extracellular reaction, staining is hindered by increased intracellular alkalinity. 3. These facts are in opposition to the view that staining of cells by basic dyes is chiefly governed by a combination of the dyes with cell proteins. It is more in harmony with the view that the combination is with a substance or substances of acid nature. PMID- 19872091 TI - THE OXIDATION OF SODIUM LACTATE BY HYDROGEN PEROXIDE. AB - By means of a modification of the technique of the Osterhout apparatus it is possible to follow the production of CO(2) from sodium lactate when acted upon by H(2)O(2). The results of this process indicate that the reaction is not a simple one but is of an autocatalytic type. This conclusion is borne out by the fact that the determinations of H(2)O(2) during the reaction show an increased amount of peroxide during the earlier stages of the reaction. This is considered to be due to the formation of a peroxide by the oxidation of the acetaldehyde (formed by the interaction of H(2)O(2) and sodium lactate) with the oxygen of the air. When the reaction is carried out in an atmosphere of nitrogen no increase is observed. Further experiments in nitrogen tend to show that acetaldehyde is the end-product of the action of H(2)O(2) alone. The effect of FeCl(3) upon the reaction depends upon the previous treatment of the iron salt. If the iron solution is added to the H(2)O(2) before mixing with the lactate there is an increased amount of CO(2). If, however, the iron is added to the lactate before the addition of the peroxide, the action tends to inhibit the production of CO(2). The reaction of H(2)O(2) with sodium lactate is comparable to the action of killed yeast and methylene blue as determined by Palladin and his coworkers. PMID- 19872092 TI - THE EFFECT OF CYSTINE AND GLYCOCOLL ON THE OXIDATION OF SODIUM LACTATE BY HYDROGEN PEROXIDE. AB - The rate of production of CO(2) from sodium lactate when treated with H(2)O(2) may be increased by the addition of a compound containing a sulfhydryl group, i.e. cystine. A small part of this increase in rate of CO(2) is due to the action of the amino group as shown by the action of glycocoll. The results tend to show that the mode of action of H(2)O(2) is one of dehydrogenation and that the action of the cystine is comparable to the Atmungskorper of Meyerhof. PMID- 19872094 TI - THE RELATION BETWEEN THE INITIAL RISE AND THE SUBSEQUENT DECLINE OF MILK SECRETION FOLLOWING PARTURITION. PMID- 19872093 TI - ON STEREOTROPISM IN TENEBRIO LARVAE. AB - Larvae of Tenebrio while creeping show homostrophic responses, and stereotropic orientation to lateral contacts. Homostrophic orientation is inhibited by stereotropism. Both depend upon the anterior portion of the central nervous system. Stereotropic orientation due to unilateral contact, particularly at the anterior end, persists briefly after the cessation of the contact. Equal posterior bilateral contact of the body obliterates stereotropic bending. Unequal posterior bilateral contacts lead to orientation through an angle roughly proportional to the differences in contact areas. Functional symmetry in such responses is not disturbed by asymmetrical distribution of the body "hairs." The stereotropic orientation undergoes reversal of direction, central in origin, when the stimulation is sufficiently intense. Stereotropic response, leading to maintained lateral contact with a surface or to bending when the end of such a surface has been passed, is inhibited by a definite intensity of light. These findings (1) round out the demonstration that stereotropism is truly of a tropistic character, and (2) make possible the understanding of conduct in a case involving the participation of contact stimulation, phototropism, temperature, and homostrophy. PMID- 19872095 TI - VALENCY RULE AND ALLEGED HOFMEISTER SERIES IN THE COLLOIDAL BEHAVIOR OF PROTEINS : III. THE INFLUENCE OF SALTS ON OSMOTIC PRESSURE, MEMBRANE POTENTIALS, AND SWELLING OF SODIUM GELATINATE. AB - A detailed study was made on the influence of salts on those physicochemical properties of sodium gelatinate which are regulated by Donnan's law of membrane equilibria; namely, osmotic pressure, membrane potentials, and swelling. It was found that the influence of salts on these properties in the case of sodium gelatinate obeys the same rules of valency as in the case of the influence of salts on gelatin chloride as discussed in a previous publication. The rules state that when a salt is added to an ionized protein, without causing a change in the hydrogen ion concentration of the protein, the general effect is a depression of the mentioned properties. The degree of depression depends not only on the concentration of the salt but on the electrical properties of the ions constituting the salt. Of the two or more oppositely charged ions of which a salt consists, only the valency of those ions which carry charges opposite to those carried by the protein ions affects the degree of depression which increases with the valency of the ions. It was also found that the phenomenon of swelling of gelatin becomes modified by solubility of the gelatin when salts are added in concentrations higher than N/4. Emphasis is laid on the point that the valency rule holds perfectly also in relation to swelling as long as the phenomenon is pure swelling which is the case when salt solutions of concentrations lower than N/4 are added to gelatin. PMID- 19872096 TI - NUTRITIONAL STUDIES ON THE CONFUSED FLOUR BEETLE, TRIBOLIUM CONFUSUM DUVAL. AB - The confused flour beetle (Tribolium confusum) was chosen for this study because it lives in a food which ordinarily contains no living organisms. The death rates are greater in cultures which are handled daily than in those which are not handled but when all are handled alike the results are comparable. The results from experiments with individual beetles in various kinds of flour were plotted with instars (larval stages) on the ordinate and time in days on the abscissa, using the results from control experiments in wheat flour to determine the length of the various instars from an "x = y" formula. The curves of development were found to be straight lines throughout all but the last instar. The curve for the last instar during which the larva transformed deviated from the straight line in certain foods, notably rice flour. When mass cultures were used the death and transformation curves were plotted for each synthetic food. A comparison of the curves from wheat flour and the synthetic foods shows that the first parts of the curves are very much alike in all cases and that a few resemble the control in every respect except that the transformation curve has been moved back for a considerable time. The death curves for the mass cultures are not smooth but show sudden increase in death at approximately the times of molting. These curves may therefore be compared with the records from individual beetles. PMID- 19872097 TI - CHANGES IN THE STABILITY AND POTENTIAL OF CELL SUSPENSIONS : II. THE POTENTIAL OF ERYTHROCYTES. AB - 1. Human and sheep erythrocytes, when placed in 0.01 N buffer solutions at reactions more acid than pH 5.2, undergo a progressive change in potential, becoming less electronegative or more electropositive. This change usually occurs within 2 hours at ordinary room temperatures. It did not occur when rabbit erythrocytes were used. 2. This change is due primarily to the liberation of hemoglobin from some of the cells. 3. Hemoglobin, even in very low concentrations, markedly alters the potential of erythrocytes in the more acid reactions. This is due to a combination between the electropositive hemoglobin and the erythrocytes. The effect of the hemoglobin is most marked in the more acid solutions; it occurs only on the acid side of the isoelectric point of the hemoglobin. 4. The isoelectric point of erythrocytes in the absence of salt, or in the presence of salts having both ions monovalent, occurs at pH 4.7. This confirms the observations of Coulter (1920-21). Divalent anions shift the isoelectric point to the acid side. 5. The effect of salts on the potential of erythrocytes is due to the ions of the salts, and is analogous in every way to the effect of salts on albumin-coated collodion particles, as discussed by Loeb (1922-23). PMID- 19872098 TI - THE GROWTH OF THE THYROID AND POSTBRANCHIAL BODY OF THE SALAMANDER, AMBYSTOMA OPACUM. PMID- 19872099 TI - THE AGGLUTINATION OF RED BLOOD CELLS. AB - 1. Unsensitized sheep cells suspended in sugar solutions are agglutinated by electrolytes whenever the potential is depressed to 6 millivolts or less, except in the case of MgCl(2) or CaCl(2). 2. With these salts no agglutination occurs although there is practically no potential. The presence of these salts prevents acid agglutination. This is presumably due to a decrease in the "cohesion" between the cells. 3. Cells which have been sensitized with specific antibody, ricin, colloidal stannic hydroxide, or paraffin oil, are agglutinated whenever the potential is decreased below about 12 millivolts. 4. The agglutination by electrolytes is therefore primarily due to a decrease in the potential whereas agglutination by immune serum, ricin, etc., is due primarily to an increase in the critical potential. PMID- 19872100 TI - THE LOCUS OF THE ACTION OF VERATRIN. AB - 1. In Mnemiopsis veratrin shows two stages of veratrin poisoning. First, inhibition of the beats of the plates which disappears on cutting them away either singly or in small groups. Second, after half an hour mechanical stimulation excites the beat of the plates in the intact veratrinized animal. It is concluded that veratrin acts on nervous tissue and not on the substance of the swimming plates. 2. In Lumbricus, veratrin acts on the ventral nerve cord alone, and not on the muscles and peripheral nerves. 3. In Musca, veratrin first causes opisthotonos, then spasms and extreme flexion of the legs. Decapitation causes these effects to disappear hence veratrin acts on the cerebral ganglia of the fly. 4. Veratrin applied to the sciatic nerve of the frog causes, after a latent period of 20 minutes, irregular contractions of the gastrocnemius which persist for an hour or more. Veratrin is thus a neurophil alkaloid of the first class as well as second and in this way resembles tetraethyl ammonium chloride. 5. If the end of a sciatic nerve is dipped into veratrin solution, then direct stimulation of the gastrocnemius muscle results in contraction with delayed relaxation, although the muscle itself is not subject to the action of veratrin. 6. By means of preparations of the sartorius muscle of the frog it is shown that veratrin acts not on the muscle cells directly but on the nerve fibers. Hence veratrin produces the characteristic muscle curve showing delayed relaxation by its action on the nervous elements. PMID- 19872101 TI - SURFACE TENSION OF SERUM : XI. AN IMPROVEMENT OF THE TECHNIQUE FOR MEASURING SURFACE TENSION. PMID- 19872102 TI - A NOTE ON THE SIMILARITIES BETWEEN THE CURVES OF GROWTH AND OF REGENERATION. AB - The curves of growth and of regeneration follow the same course, and can be represented by the same exponential equation. This is taken to substantiate the theory that growth and regeneration are essentially identical processes governed by the same laws. A common peculiarity of the curves of growth and of regeneration is that during a short period in the early stages of regeneration and of growth, the apparent observed speed of these processes seems to be relatively slow. As a result, the curve of the fitted equation cuts the time axis not at zero, the beginning of growth or regeneration, but somewhat later. Data on regeneration are cited indicating that the initial slow phase of regeneration is due to the time required for the formation of a cap of embryonic cells which serves as a basis for the more active later regeneration; in other words, to qualitative growth which cannot be expressed in terms of quantitative units. It is suggested that the apparent initial slow phase of growth of the individual from the fertilized egg is due to a similar qualitative growth. It is suggested that if the initial qualitative changes could be converted into some common unit with the subsequent quantitative changes, the apparent initial lag would disappear, and the exponential equation representing the course of these processes would then be the same as the equation used to represent the course of a monomolecular chemical reaction. Certain implications of this reasoning are discussed in the text. PMID- 19872103 TI - THE EFFECT ON THE EXTERNAL PARATHYROID GLANDS OF THE EXPOSURE OF RABBITS TO ULTRA VIOLET LIGHT. PMID- 19872104 TI - WAVE LENGTH OF LIGHT AND PHOTIC INHIBITION OF STEREOTROPISM IN TENEBRIO LARVAE. AB - A definite intensity of white light is required (about 136 m.c.) to produce negative phototropic orientation of creeping Tenebrio larvae away from contact with a vertical glass surface. This gives a measure of stereotropism in terms of phototropism, or reciprocally. The effectiveness of light for the suppression of stereotropism varies with wave length. It is therefore simple to obtain a measure of the relation between wave length and stimulating efficiency in this case of phototropic orientation. By determinations of the minimal energy required to inhibit stereotropism with different regions of the spectrum, it is found that the maximum effectiveness is sharply localized in the neighborhood of 535micromicro. The curve connecting stimulating efficiency with wave length, while giving a picture of the effective absorption by the photosensory receptors, probably does not permit accurate characterization of the essential photosensitive material. PMID- 19872105 TI - GROWTH OF MAIZE SEEDLINGS AS AFFECTED BY GLUCOKININ AND INSULIN. AB - 1. Solutions of glucokinin and insulin, particularly those from which the easily dialyzable substances had been removed, increased the growth of roots and tops of young maize seedlings, as shown by comparisons with untreated seedlings grown in distilled water. 2. Strong solutions of crude glucokinin or of crude insulin repressed growth. 3. Seedlings from which the tips of the primary roots had been removed just before placing the plants in the test solutions made greater gains in both top growth and root growth than seedlings with uncut roots treated with solutions of the same strength. Control experiments showed that this difference in growth was not the result of cutting the roots, and that crude glucokinin and crude insulin contained several substances some of which were more readily absorbed by the plant than others. 4. Purification of crude glucokinin and crude insulin by dialysis showed that the residue of relatively non-dialyzable substance was the growth-promoting fraction. 5. The dialysate of crude glucokinin contained at least three types of material, one of which repressed growth. 6. Ammonium sulfate, one of the possible impurities of glucokinin, repressed the growth of seedlings but did not produce the other changes in metabolism shown by seedlings treated with dialysate of onion glucokinin. 7. The endosperm of plants treated with growth-promoting solutions of purified insulin did not lose weight as rapidly as the endosperms of untreated plants, indicating that the treated plants made their greater gains in growth by more efficient utilization of the endosperm, or as a result of greater photosynthetic activity, or by a combination of these. 8. Experiments with albino seedlings suggested that the greater gain in weight made by plants treated with insulin was the result in part of increased photosynthetic activity. PMID- 19872106 TI - THE EFFECT OF ULTRA-VIOLET, X-RAY, AND RADIUM RADIATION ON THE TOXICITY OF NORMAL BLOOD. AB - While the number of experiments performed is perhaps somewhat limited the results obtained were quite definite and warrant the following conclusions. The toxicity of normal blood for living plant protoplasm as studied on the growth of Lupinus albus seedlings is definitely influenced by various radiations. Ultra-violet rays produce no effect on normal blood or may even render it slightly less toxic. Roentgen rays render normal blood more toxic. The toxicity is greater in the case of the blood plasma as compared with the blood cells and a more toxic effect is produced with the Coolidge tube as compared with the gas tube. Radium emanations in the few experiments performed produced changes very much the same as those given by the x-rays. PMID- 19872107 TI - THE INFLUENCE OF ELECTROLYTES ON POLLEN TUBE DEVELOPMENT. AB - These experiments serve to show that neutral salts in amounts considerably below those commonly employed in culture solutions may be very injurious to pollen. It has been found, for example, that NaCl, one of the least toxic salts tried, excepting CaCl(2), added to a sucrose solution in a concentration of 0.0002 M, or about 11 parts per million, reduces the growth of sweet pea pollen tubes 15 per cent. When it is considered that MgCl(2) and BaCl(2) are about fifteen times as toxic as NaCl it becomes evident that the susceptibility of pollen tubes to injury by these substances amounts virtually to hypersensitiveness. On the other hand calcium salts in concentrations ranging from 0.02 to 0.002 M markedly enhance the growth of sweet pea pollen tubes. MgCl(2) has a similar action in the case of Nicotiana. Calcium, moreover, exerts a strong protective action in the presence of the injurious monovalent cations Na and K. So far as can be determined by microchemical means these salts do not alter the wall of the pollen tube; presumably, their effect is on the protoplast itself. In the light of recent experimentation (Osterhout) with other forms better adapted to precise investigation of these phenomena it seems probable that the explanation of the facts presented here lies in changes brought about in the permeability of the cells. Since several gaps exist in our evidence, however, conclusions drawn at this time must necessarily be provisional. The highly injurious action manifested by the cations of several of the salts used indicates that they penetrate the protoplast very rapidly. Possibly in pure sucrose cultures, exosmosis is a limiting factor in pollen tube growth. The addition of salts of calcium or magnesium may favor development by retarding or preventing this outward diffusion. The protective effect of calcium in the presence of the toxic cations K and Na is best interpreted on the assumption that the entry of these latter into the protoplast is retarded by the calcium. The mode by which hydrogen ion concentration affects pollen tube growth is largely a matter of speculation. It has previously been been shown by Brink that the time relations of the growth process simulate those of an autocatalytic reaction. It has been demonstrated also that elongation of the tubes in artificial media is related to the digestion of the reserve food materials contributed by the pollen grain. In the case of the sweet pea these stored substances are largely fats and their hydrolysis may constitute the most important chemical reaction in growth. If, as seems not improbable, the other reactions involved wait upon this one, it is the "master reaction" according to Robertson's hypothesis. If this conception really applies to the case in hand as outlined, the effect of the concentration of hydrogen ions on growth may be a direct one. It is known that the action of the fat-splitting enzyme lipase is favored by a certain amount of free acid. The maximum rate of germination of the pollen and the greatest amount of growth of the pollen tubes occur at pH 6.0. This may be due in large part to the immediate effect of this concentration of hydrogen ions upon the digestion of the reserve food. PMID- 19872108 TI - THE EFFECT OF POTASSIUM ON THE ACID METABOLISM OF SURVIVING SKELETAL AND CARDIAC MUSCLES OF THE FROG. AB - The potassium contraction of skeletal muscle and relaxation of cardiac muscle have been correlated with the carbon dioxide and total acid production of these tissues. 1. The immersion of surviving sartorius muscles of the frog in isotonic potassium chloride solution causes a marked increase in the rate of acid production. 2. It is probable that carbon dioxide is the principal acid involved in the above effect. 3. The immersion of surviving cardiac muscle of the frog in isotonic potassium chloride solution causes a pronounced depression in the rate of survival acid production. 4. Reasons are given for believing that these changes in metabolism may be independent of the stimulation and inhibition of contraction which potassium simultaneously produces in these tissues. PMID- 19872109 TI - THE ALKALINE ISOPOTENTIAL POINT OF THE BACTERIAL CELL. AB - Irregularities in migration velocity of bacterial cells in the highly alkaline solutions are due to the buffering effect of the cells upon the immediately adjacent zone of menstruum. Consistent results can be obtained by shaking the suspension thoroughly before placing it in the electrophoretic cell. When observed in this way both Bacillus cereus and Bacterium coli show an isopotential point near pH 13.5, that for Bacillus cereus being slightly below, and that for Bacterium coli slightly above this point. At more alkaline reactions the cells acquire a positive charge which increases with further increase in pH to very high values. PMID- 19872110 TI - A NOTE ON THE RELATIVE PHOTOSENSORY EFFECT OF POLARIZED LIGHT. AB - Experiments were made to compare the stimulating effectiveness of vertically and horizontally polarized lights and non-polarized lights of equal intensity upon phototropic movements of the beetle Tetraopes tetraopthalmus; and to compare the effectiveness of two light beams polarized at right angles to one another upon phototropic orientation of the land isopod Cylisticus convexus. Tetraopes is positively, and Cylisticus, negatively phototropic. Tests were also made of the intensities of horizontally and of vertically polarized light required to inhibit stereotropism in larvae of Tenebrio. Under the conditions of the tests, no certain qualitative effect connected with polarization could be detected. PMID- 19872111 TI - THE LOCOMOTION OF LIMAX : I. TEMPERATURE COEFFICIENT OF PEDAL ACTIVITY. AB - Pedal progression of the slug Limax maximus was studied to obtain relations between wave velocity on the sole of the foot, wave frequency, the advance due to a single wave, and the velocity of vertically upward creeping. Each of the first three quantities is directly proportional to the simultaneous velocity of progression. Under comparable conditions, that is when work is done at a constant rate, the frequency of pedal waves is influenced by the temperature according to the equation of Arrhenius, with micro = 10,700 (Q(10) for 11 degrees to 21 degrees = 2.1). The velocity of a single wave must have very nearly the same "temperature characteristic," which is found also in another case of nerve net transmission (in Renilla). PMID- 19872112 TI - THE KINETICS OF TRYPSIN DIGESTION : V. SCHUTZ'S RULE. AB - The rate of digestion of concentrated casein solutions by low concentrations of trypsin at 0 degrees has been followed. Under these conditions the enzyme is inhibited by the product of the reaction and under certain conditions this effect should lead to Schutz's rule, i.e. the amount of hydrolysis should be proportional to the square root of the product of the time into the enzyme concentration. This is the result obtained. Both Schutz's rule and Arrhenius' equation fail to hold accurately owing to the incorrect relation assumed to hold between the rate of hydrolysis and the substrate concentration. PMID- 19872113 TI - PHOTOCHEMISTRY OF VISUAL PURPLE : III. THE RELATION BETWEEN THE INTENSITY OF LIGHT AND THE RATE OF BLEACHING OF VISUAL PURPLE. AB - It is shown that the velocity of bleaching of visual purple by light, under comparable conditions of concentration, volume, and surface exposed, is directly proportional to the intensity. PMID- 19872114 TI - THE ELECTRIC CONDUCTIVITY OF DISPERSE SYSTEMS. PMID- 19872115 TI - THE SOLUBILITY OF TYROSINE IN ACID AND IN ALKALI. AB - Measurements have been made of the solubility at 25 degrees C. of tyrosine in hydrochloric acid and in sodium hydroxide solutions varying from 0.001 to 0.05 M, and also in distilled water. The pH of the saturated solutions was measured with the hydrogen electrode. The following values for the ionization constants of tyrosine have been obtained from the measurements: k(b) = 1.57 x 10(-12), k(a1) = 7.8 x 10(-10), k(a2) = 8.5 x 10(-11). The changes in solubility with pH can be satisfactorily explained by the use of these ionization constants. PMID- 19872116 TI - APPLICATION OF THE DIFFUSION HYPOTHESIS TO MEMBRANE POTENTIALS. AB - A system consisting of two aqueous solutions, containing equal concentrations of lactic acid, but different concentrations of Na lactate, separated by a layer of amyl alcohol has been described. This system exhibits electrical properties ranging (as the concentration of NaL is increased) from those characteristic of a simple Donnan equilibrium to those characteristic of simple diffusion. The fact that the Donnan P.D. can be treated as a special case of a diffusion potential has been emphasized. The experiments call attention to the effect of the thermodynamic properties of the membrane, and it is suggested that such properties as conductivities, ionic mobilities, and distribution coefficients in membranes of any sort should be investigated. The experiments afford an interesting example of "phase reversal." PMID- 19872117 TI - MEMBRANE EQUILIBRIA AND THE ELECTRIC CHARGE OF RED BLOOD CELLS. AB - It has been shown, within the probable limit of error of the methods of measurement employed, that the Donnan equilibrium determines the distribution of H and Cl ions between the cell and the surrounding fluid. This equilibrium is a consequence of the impermeability of the cell membrane to the inorganic cations of the cell. The mechanism responsible for this equilibrium is suggested as that concerned in the secretion of HCl by the cells of the gastric mucosa. If the salt concentration of the medium is low there may result from the Donnan equilibrium a thermodynamic P.D. of considerable magnitude. In the presence of low concentrations of electrolytes, this P.D. is to be regarded as positive in sign at reactions of the medium at which the cataphoretic charge of the cell is negative in sign. The explanation of this discrepancy in sign of charge may lie in the existence at an outer phase-boundary of a second Donnan equilibrium the nature of which is determined by the ionization of the protein of the cell membrane. PMID- 19872118 TI - ON THE CRITICAL THERMAL INCREMENT FOR THE LOCOMOTION OF A DIPLOPOD. PMID- 19872119 TI - CRITICAL THERMAL INCREMENT FOR THE MOVEMENT OF OSCILLATORIA. AB - In a species of Oscillatoria exhibiting movement of type suitable for exact measurement the velocity of linear translatory motion is found to be controlled by the temperature (6 - 36 degrees C.) in accordance with Arrhenius' equation for irreversible reactions. The value of the critical increment (micro) is 9,240. The extreme variates in series of measurements at different temperatures yield the same value of micro. The velocity of movement is therefore regarded as determined by the velocity of an underlying chemical process, controlled by the temperature and by the amount of a substance (? catalyst) whose effective quantity at any moment varies within definite limits in different filaments of the alga. On the basis of its temperature characteristic the locomotion of Oscillatoria is compared with certain other processes for which this constant is calculated. PMID- 19872120 TI - PHOTOTROPIC CIRCUS MOVEMENTS OF LIMAX AS AFFECTED BY TEMPERATURE. AB - 1. The theory of animal phototropism requires for particular instances a knowledge of the action of light as exerted through each of two bilaterally located receptors functioning singly. The measurement of "circus movements" which this involves must be concerned with such aspects of the reaction as are demonstrably dependent upon the effect of light. 2. The negatively phototropic slug Limax maximus exhibits very definite and continuous circus movement under vertical illumination when one eye-tentacle has been removed. The amplitude of the circling movement, measured in degrees deflection per cm. of path as an index of maintained differential tonus, is intimately related to the concurrent velocity of creeping. Analysis of the orienting mechanism is facilitated by the fact that in gasteropods such as Limax the animal creeps by means of the pedal organ, but orients (turns) by a totally distinct set of muscles in the dorsal and lateral regions of the body wall. 3. The expression of the phototropic orienting tendency, with illumination constant, is greatly influenced by the temperature. Above a zone centering at 15 degrees , the amplitude of turning (degrees per cm. of path) is determined by the temperature in accurate agreement with Arrhenius' equation for chemical reaction velocity, with the critical increment micro = 16,820; and the rate of creeping is progressively less as the temperature rises, micro for its reciprocal being 10,900. Below 15 degrees , the velocity of creeping becomes less the the lower the temperature, micro being again 16,800; while the amplitude of orientation is limited merely by the velocity of creeping, its reciprocal being directly proportional thereto. 4. Measurements of Limax circus movements in terms of turning deflection as function of light intensity must therefore be carried out at a temperature well above 15 degrees . 5. The analysis provides a gross physical model of how an end-result may be influenced by temperature according to the effect of temperature upon each of several interconnected processes when the "temperature vs. effect" curves for these processes dynamically intersect. 6. It is pointed out that a certain type of unpredictability (quantative variability) in animal behavior under "normal" natural conditions probably results from dynamic equilibrium there obtaining between diverse mechanisms competing for effector control (in the present case, the creeping mechanism and that for turning, in the range 14-16 degrees C.). It follows that the unraveling of the elements of conduct necessitates experimentation under diverse abnormal conditions favoring individual mechanism of response. PMID- 19872121 TI - THE INFLUENCE OF OXYGEN TENSION UPON METABOLIC RATE IN INVERTEBRATES. AB - It is shown that in several of the higher invertebrate animals, oxygen consumption is directly proportional to the oxygen tension in the sea water, over a wide range. PMID- 19872122 TI - SOME PHYSIOLOGICAL ACTIONS OF CYANIDES. AB - 1. The physiological actions of HCN and its salts appear to be due (a) to the ease with which HCN molecules penetrate living cells and then ionizing, exert their influence by means of H ions and CN ions; (b) to the weakness of HCN as an acid, which permits at neutrality or at even slight alkalinity the presence of a considerable amount of free HCN molecules in the presence of their salts; (c) to specific effects occasioned by its chemical activity. 2. The order of resistance of various protozoans to HCN resembles that of the same protozoa to CO(2) and to H(2)S, but is the reverse of their resistance to mineral acids. 3. HCN in acid, neutral, or slightly alkaline media produces intracellular acidity because of the rapid penetration of HCN molecules into the cell. 4. HCN acts specifically on certain species of protozoa, the order of resistance of Paramecia being Paramecium caudatum > Paramecium mullimicronucleatum > Paramecium aurelia > Paramecium bursaria. PMID- 19872123 TI - THE COMBINATION OF SALTS AND PROTEINS. I. AB - 1. It has been found that the ratios of the total concentrations of Ca, Mg, K, Zn, inside and outside of gelatin particles do not agree with the ratios calculated according to Donnan's theory from the hydrogen ion activity ratios. 2. E.M.F. measurements of Zn and Cl electrode potentials in such a system show, however, that the ion activity ratios are correct, so that the discrepancy must be due to a decrease in the ion concentration by the formation of complex ions with the protein. 3. This has been confirmed in the case of Zn by Zn potential measurements in ZnCl(2) solutions containing gelatin. It has been found that in 10 per cent gelatin containing 0.01 M ZnCl(2) about 60 per cent of the Zn(++) is combined with the gelatin. 4. If the activity ratios are correctly expressed by Donnan's equation, then the amount of any ion combined with a protein can be determined without E.M.F. measurements by determining its distribution in a proper system. If the activity ratio of the hydrogen ion and the activity of the other ion in the aqueous solution are known, then the activity and hence the concentration of the ion in the protein solution can be calculated. The difference between this and the total molar concentration of the ion in the protein represents the amount combined with the protein. 5. It has been shown that in the case of Zn the values obtained in this way agree quite closely with those determined by direct E.M.F. measurements. 6. The combination with Zn is rapidly and completely reversible and hence is probably not a surface effect. 7. Since the protein combines more with Zn than with Cl, the addition of ZnCl(2) to isoelectric gelatin should give rise to an unequal ion distribution and hence to an increase in swelling, osmotic pressure, and viscosity. This has been found to be the case. PMID- 19872124 TI - OBSERVATIONS ON THE INJURIOUS EFFECTS OF HIGH TEMPERATURES ON FROG SKIN. AB - 1. The P.D. between the two surfaces of the skin of the frog, when measured under standardized conditions, may be used as a means of studying the phenomena of injury, recovery, and death. Injurious conditions decrease the P.D. 2. According to the severity of the injury produced by temporary exposure to high temperatures, frog skin may show, as judged by this criterion (a) complete recovery, (b) partial recovery, or (c) a progressive change leading to death. PMID- 19872125 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS : III. THE RELATION BETWEEN THE AMINO ACID COMPOSITION OF CASEIN AND ITS CAPACITY TO COMBINE WITH BASE. AB - 1. The methods of measuring the base-combining capacities of proteins have been considered, and the constants and corrections that are employed in their calculation have been critically examined. 2. The base-combining capacities of ten casein preparations have been determined. These differed from each other to a far greater extent than can be attributed to the experimental errors involved in their measurement and calculation. The variations were, moreover, systematic in manner, and can be explained as dependent upon the method employed in the preparation of the casein. 3. Casein that had never been exposed to greater alkalinities than those in which it exists in nature combined with approximately 0.0014 mols of sodium hydroxide per gm., while casein prepared nach Hammarsten, and casein that was saturated with base during its preparation, combined with approximately 0.0018 mols of sodium hydroxide per gm. 4. 1 mol of sodium hydroxide, therefore, combined with 735 gm. of casein that had not previously been exposed to alkaline reactions, or with 535 gm. of casein that had previously been saturated with base. 5. If the minimal molecular weight of casein, based upon its tryptophane content, is placed at 12,800, the native protein must, therefore, contain approximately eighteen acid groups, and in addition six acid groups that are released in alkaline solutions, and presumably represent internally bound groups. The total base-combining capacity therefore represents that of a substance with a molecular weight of 12,800 and containing twenty-four acid valences. 6. This base-combining capacity is no greater than can be accounted for on the basis of our knowledge of the structure and composition of casein. On the basis of a molecular weight of 12,800 casein contains at least 19 molecules of glutamic acid, 4 of aspartic, and 8 of hydroxyglutamic acid. If the amino acids in the protein molecule are bound to each other in polypeptide linkage, each of these thirty-one dicarboxylic acids should yield terminal groups. The ammonia in casein suggests that twelve of these groups are bound as amides. As many as nineteen carboxyl groups may, therefore, be free in the protein molecule. 7. Casein contains phosphorus. If this phosphorus represents phosphoric acid, and if we consider that all of the valences of this acid are either themselves free, or that they have liberated carboxyl groups by entering into the structure of the protein molecule, casein should contain nine additional acid groups. 8. Recent analytical results, therefore, indicate that casein contains at least nineteen, and possibly twenty-eight, free acid groups. The physicochemical measurements presented suggest that casein combines with base as though it contained twenty-four acid groups, of which six, or one-fourth, appear to be bound in the native protein. These experimental results are therefore in close agreement with the expectation on the basis of the classical theory of protein structure. PMID- 19872126 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS : IV. THE RELATION BETWEEN THE COMPOSITION OF ZEIN AND ITS ACID AND BASIC PROPERTIES. PMID- 19872127 TI - THE INFLUENCE OF ELECTROLYTES ON THE STABILITY OF RED BLOOD CORPUSCLE SUSPENSIONS. AB - Two types of stability are observed in suspensions of red blood cells. In weak concentrations of electrolytes the stability depends on the electric charge of the cells and suspension is unstable below a certain critical P.D. In strong concentrations of electrolyte, the stability bears no relation to the charge. PMID- 19872128 TI - TEMPERATURE AND FORWARD MOVEMENT OF PARAMECIUM. AB - 1. The rate of forward movement in Paramecium as affected by changes in temperature can be described accurately in terms of the Arrhenius equation. See PDF for Equation 2. For the range from 6-15 degrees , micro = 16,000; from 16-40 degrees , micro = 8,000. These values fall within the limits characteristic for chemical processes. 3. On the principle of velocity control by the slowest rate, it is assumed that in Paramecium at temperatures above normal, control passes from one underlying reaction to another. 4. The views expressed by Rice, the recent results of Crozier, and certain micro values given by Arrhenius all suggest that micro = 16,000 may represent an oxidation, and micro = 8,000 either a modified oxidation or an hydrolysis. 5. For the system of controls, the catenary series O --> A --> E with the lower micro value attached to the precursor reaction is adequate. We may also assume a cyclical system analogous to Meyerhof's conception of carbohydrate metabolism in muscle. In this case it is necessary to assign micro = 16,000 to the oxidation of A and E and micro = 8,000 to the synthesis E --> O. This model also accounts for the fact that the data might be interpreted as involving, apparently, a depletion of A at the higher temperature. PMID- 19872129 TI - ON BIOLOGICAL OXIDATIONS AS FUNCTION OF TEMPERATURE. AB - 1. The critical thermal increments are calculated for respiratory processes (O(2) consumption, CO(2) production) in various plants and animals. They are characteristically found to be of two, possibly three, types: micro = 11,500, and 16,100 or 16,700. The first is commonly encountered above 15 degrees , the second below that temperature, but these relations may be reversed. (The value of micro may be significantly changed in inanition.) 2. For reduction of methylene blue by bacteria, through removal of H from succinic acid, micro = 16,700. This process (Quastel and Whetham, 1924) at constant temperature is a function of the hydroxyl ion concentration. The suggestive identity is pointed out of the critical increment for this reduction phenomenon with that deduced for biological respirations in which a dehydrogenation mechanism is supposed to be of widespread occurrence, and in connection with which Fe very likely has a catalytic role. The action of OH' is believed to be revealed in the value micro = 11,500, frequently obtained in connection with respiration. 3. A somewhat lower micro (16,140) is associated with the oxidation of Fe'', and may be compared with (1) that of respiration in sea urchin eggs, for which (Warburg) iron is catalyst, and (2) that for some simple reactions in which Fe is known to serve as catalyst; it is not found for oxidative reactions in which Fe is not involved. 4. The bearing of these findings is discussed in relation to the theory of functional analysis of concurrent catalyzed reactions in protoplasm. It is shown that for a number of activities in which the effects of respiration may safely be assumed, the values of the critical increments are consistent with those determined for processes of respiration. 5. The further development of these views may lead to an extremely important method of identifying controlling reactions in undisturbed living matter. PMID- 19872130 TI - THE PHOTOTROPIC MECHANISM IN RANATRA. AB - Definite proof is obtained that in the phototropic orientation of Ranatra the relative postures of the appendages, resulting in a bilateral difference of effective stroke in swimming, is the mechanism of orientation; the frequency of locomotor movements is the same on the two sides of the body. PMID- 19872131 TI - SUPPRESSION OF PHOTOTROPIC CIRCUS MOVEMENTS OF LIMAX BY STRYCHNINE. AB - By injection with strychnine the phototropic circus movements of the slug Limax maximus may be suppressed, its phototropism abolished. The creeping activity of the foot is not in any essential way interferred with. Strychnine produces in Limax central nervous effects of the sort associated with its characteristic action. Hence, although an effect of the drug upon photoreceptors cannot be definitely excluded, the experimental result is held to demonstrate that in orientation during circus movements there occurs central "competition" between impulses resulting (1) in the release of pedal waves and (2) in the maintenance of a turning posture. PMID- 19872132 TI - THE EFFECT OF VALENCY OF CATIONS AND ANIONS ON NEGATIVELY AND POSITIVELY CHARGED RED BLOOD CELLS. AB - 1. Under comparable conditions, valency effect may be demonstrated with a suspension of red blood cells and the cations and anions of salts. 2. The valency of the cation determines the degree of the effect on negatively charged cells, the valency of the anion, the effect on positively charged cells. 3. Anomalies in valency effects with different salts and red cell suspensions are in part due to variations in H ion concentration, depending on the degree of hydrolysis of the salt. PMID- 19872133 TI - THE VISUAL DISCRIMINATION OF INTENSITY AND THE WEBER-FECHNER LAW. AB - 1. A study of the historical development of the Weber-Fechner law shows that it fails to describe intensity perception; first, because it is based on observations which do not record intensity discrimination accurately, and second, because it omits the essentially discontinuous nature of the recognition of intensity differences. 2. There is presented a series of data, assembled from various sources, which proves that in the visual discrimination of intensity the threshold difference DeltaI bears no constant relation to the intensity I. The evidence shows unequivocally that as the intensity rises, the ratio See PDF for Equation first decreases and then increases. 3. The data are then subjected to analysis in terms of a photochemical system already proposed for the visual activity of the rods and cones. It is found that for the retinal elements to discriminate between one intensity and the next perceptible one, the transition from one to the other must involve the decomposition of a constant amount of photosensitive material. 4. The magnitude of this unitary increment in the quantity of photochemical action is greater for the rods than for the cones. Therefore, below a certain critical illumination-the cone threshold-intensity discrimination is controlled by the rods alone, but above this point it is determined by the cones alone. 5. The unitary increments in retinal photochemical action may be interpreted as being recorded by each rod and cone; or as conditioning the variability of the retinal cells so that each increment involves a constant increase in the number of active elements; or as a combination of the two interpretations. 6. Comparison with critical data of such diverse nature as dark adaptation, absolute thresholds, and visual acuity shows that the analysis is consistent with well established facts of vision. PMID- 19872134 TI - THE KINETICS OF STARVATION. AB - 1. The relative weight loss of pigeons on starving rations may be represented by a simple modification of the law of autocatalysis. 2. An equation giving the actual weight of the animals during the 53 day period of the experiment is derived by means of the hypothesis that the process of inanition is governed by the simultaneous velocity relations between two independent, homogeneous systems, such that M(T) = (A(0) --> 0) + (B(0) --> B(C)) in which A is taken proportional to the amount of carbohydrate-fat reserves, and B proportional to the amount of reacting body protoplasm. 3. The course of starvation is governed by the rate of destruction of body protein, but it is modified by the amount and by the rate of destruction of reserve materials. 4. The processes of breaking down tissues are analogous to those by which tissues are synthesized. 5. The close agreement between observed and calculated values suggests that the original assumptions set forth in deriving the foregoing equations were valid. 6. Attention is called to the fact that the time of onset of beriberi in pigeons is coincident with the half period of starvation. PMID- 19872135 TI - STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI : I. THE TRANSPORT NUMBERS OF ALKALI CASEINATE SOLUTIONS. AB - 1. The deposition of casein on a platinum anode which takes place on the passage of a direct current through solutions of alkali caseinates was quantitatively studied, and it was found that: (a) the amount of casein which is deposited is directly proportional to the current, i.e. it obeys Faraday's law; (b) the amount of casein deposited is inversely proportional (within the limits studied) to the amount of alkali which is combined with the casein. 2. A method of determining the transport numbers of proteins insoluble at their isoelectric point has been developed. 3. A titration method for determining the amount of alkali in a casein solution is given. 4. Data from the results of transference experiments on sodium caseinate, potassium caseinate, cesium caseinate, and rubidium caseinate solutions are given. It is shown that the data are best explained on the assumption that in these solutions the carriers of the current are alkali metal cations and casein anions. 5. On the basis of our transference results an explanation is given of the results which were obtained by Robertson and by Haas in their migration experiments. PMID- 19872136 TI - STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI : II. THE CONDUCTIVITIES OF ALKALI CASEINATE SOLUTIONS. AB - 1. The results of conductivity experiments with alkali caseinate solutions are given and a graphical method of extrapolation, which gives a straight line, is described. The results of the conductivity experiments are shown to be in accord with the results of the previous transference experiments. 2. The change of conductivity of the alkali caseinate solutions with temperature is shown to follow a straight line relationship. 3. The high value of the mobility which was obtained for the casein ion and the high temperature gradient are discussed in relation to McBain's theory of colloidal electrolytes. PMID- 19872137 TI - STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI : III. THE ELECTROCHEMICAL BEHAVIOR OF RACEMIC CASEIN. AB - 1. The phenomenon of protein racemization is discussed and certain deductions are made in connection with the hypothesis of Dakin to account for this phenomenon and Robertson's theory of the ionization of proteins. 2. Experimental data are given to show that the electrochemical behavior of racemic casein is not in accord with the deductions which have been drawn from the theory advanced by Robertson. 3. An analysis of the nitrogen groups of racemic casein is given and compared with a similar analysis of normal casein. From these analyses and from the electrochemical equivalent of racemic casein, it is concluded that except for the hydrolysis of amide groups, racemic casein is probably not a degradation product of casein. 4. Considerable evidence is presented against the view that the -COHN- groups take part in the reactions of the protein molecule with acids and with bases. PMID- 19872138 TI - THE ELECTRICAL CONDUCTIVITY OF PURE PROTOPLASM. AB - The electrical conductivity of the plasmodium of the slime-mold Brefeldia maxima (Fr.) Rost., which constitutes practically pure protoplasm, was found to be approximately equivalent under normal conditions to that of a 0.00145 N NaCl solution, and about 2.8 times that of the liquid in contact with which it developed. When bathed in 1 per cent sea water, the conductivity was much increased, becoming greater than that of the surrounding fluid. These preliminary tests are in agreement with the supposition that the protoplasm is permeable to and in equilibrium with its environment in so far as electrolytes are concerned. PMID- 19872139 TI - STUDIES ON BIOLUMINESCENCE : XVII. FLUORESCENCE AND INHIBITION OF LUMINESCENCE IN CTENOPHORES BY ULTRA-VIOLET LIGHT. AB - 1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue. 2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark. 3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light). 4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material. 5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material. 6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent. 7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents. PMID- 19872140 TI - THE NUMBER OF BLOOD CORPUSCLES IN FISHES IN RELATION TO STARVATION AND SEASONAL CYCLES. PMID- 19872141 TI - NOTE ON THE EXCITATION AND INHIBITION OF LUMINESCENCE IN BEROE. AB - 1. The ions of Ca and K condition general luminescence, and are therefore necessary to the conduction of the impulse. 2. In van't Hoff's solution from which Mg is omitted, Beroe shows hyperirritability with respect to luminescence. This is the result of the action of Ca and K ions unantagonized by Mg. 3. The luminescent material spread on filter paper does not show luminescence in sea water, NaCl, MgCl(2), or saccharose solutions isotonic with sea water. In solutions of CaCl(2), SrCl(2), BaCl(2), KCl, and K(2)SO(4) the indicator paper glows with a bright luminescence. 4. In dark adapted Beroe, luminescence is inhibited by a certain quantity of light. This quantity has an average value of 57,285 meter-candle-minutes, which is twelve times the value given by Mnemiopsis. PMID- 19872142 TI - CONDUCTIVITY AS A MEASURE OF THE PERMEABILITY OF SUSPENDED CELLS. AB - The problem of determining by means of measurements of electrolytic conductance the permeability of living cells in suspension is considered in some detail and it is pointed out that several factors, usually neglected, have an important influence on the interpretation of such studies. These are: 1. The relative volume and the shape of cells, which are responsive to changes in osmotic pressure and constitution of the surrounding solution. The sources of error in various methods of determining the true volume of red blood cells in a suspension are explained. The hematocrit method appears to be the most reliable method in this case. 2. The proportion of living cells, which is especially to be regarded in the case of suspensions of bacteria. It is shown that this may be very high when appropriate cultural methods are used. The conductance of the dead cells must also be taken into account. 3. The progressive nature of the changes occurring during the course of an experiment. Approximate accuracy may be obtained by proper interpolation. 4. The conductivity of the protoplasm itself, which varies in response to variations is that of the surrounding fluid. It is emphasized that cells, and in particular red blood cells, are not to be regarded as stable non-conducting particles, but rather as labile and as permeable to electrolytes. It is shown that the available data support this interpretation. PMID- 19872143 TI - THE EFFECT OF LIGHT ON THE PERMEABILITY OF PARAMECIUM. AB - 1. The permeability of Paramecium to NH(4)OH is greater when the cells are exposed to light than it is when they are in darkness. 2. This change can be demonstrated in cells exposed to monochromatic red light, though it is small. It becomes greater as the wave lengths shorten, and is greatest in the near ultra violet. 3. The permeability increases as the duration of exposure to light is prolonged. 4. These experiments demonstrate the necessity of controlling the illumination when using Paramecium in physiological tests. PMID- 19872144 TI - THE KINETICS OF THE DECOMPOSITION OF PEROXIDE BY CATALASE. AB - It has been shown that the experimental results obtained by Morgulis in a study of the decomposition of hydrogen peroxide by liver catalase at 20 degrees C. and in the presence of an excess of a relatively high concentration of peroxide are quantitatively accounted for by the following mechanisms. 1. The rate of formation of oxygen is independent of the peroxide concentration provided this is greater than about 0.10 M. 2. The rate of decomposition of the peroxide is proportional at any time to the concentration of catalase present. 3. The catalase undergoes spontaneous monomolecular decomposition during the reaction. This inactivation is independent of the concentration of catalase and inversely proportional to the original concentration of peroxide up to 0.4 M. In very high concentrations of peroxide the inactivation rate increases. 4. The following equation can be derived from the above assumptions and has been found to fit the experiments accurately. See PDF for Equation in which x is the amount of oxygen liberated at the time t, A is the total amount of oxygen liberated (not the total amount available), and K is the inactivation constant of the enzyme. PMID- 19872145 TI - ELECTROENDOSMOSIS THROUGH MAMMALIAN SEROUS MEMBRANES : I. THE HYDROGEN ION REVERSAL POINT WITH BUFFERS CONTAINING POLYVALENT ANIONS. AB - It is shown that when a mammalian serous membrane bathed in dilute buffer is traversed by an electric current, liquid is caused to stream through the membrane toward the cathode when the pH value of the buffer is on the alkaline side of a certain critical hydrogen ion concentration. Streaming is toward the anode on the acid side of the reversal point. Simple means for studying this electroendosmosis quantitatively are described. The mean values of the reversal points in all cases studied with the present buffers lie between pH = 4.3 and 5.3. The membranes studied have been the mesentery of the living and dead animal, and the parietal pericardium and pleura, post mortem. The membranes of dogs, cats, rabbits, and two human pericardia have been studied. All these membranes are essentially sheets of connective tissue, bearing blood vessels, lymphatics, and nerves, and in some instances fat cells, and lined on each surface by a single layer of pavement mesothelial cells. Intercellular fibers form the major bulk of the lean membranes. These are predominantly collagenous except in the pleural region used, in which elastin fibers are present in large proportion. By using buffers alternately more acid or more alkaline than the reversal point, the direction of liquid flow across any given membrane site could be reversed an indefinite number of times. The time interval required is only that taken by the requisite manipulation in changing buffers and making the runs. The mean values of the reversal points for the several membranes when bathed in hypotonic, unbalanced buffer and in isotonic, physiologically balanced buffers showed only small and inconstant differences. The fat and lean pericardia similarly showed small difference in the positions of the mean reversal points. The apparent reversal points for the mesenteries of living animals proved to be lower than those for the mesenteries post mortem. This low value in the animals with functioning circulation is interpreted as essentially due to admixture with the buffers of buffer salts from the blood. Clear differences between the reversal points of the membranes in the first compared with later hours or days post mortem were not detected, with the possible exception of a small shift toward the acid range of the fat pericardium reversal points estimated several days post mortem. The reversal points with cat membranes were somewhat lower (more acid) than those of the dog. The approximate mean reversal points found with the citrate-phosphate buffers used were as follows: For mesenteries of living animals pH = 4.4; for mesenteries, post mortem, pH = 4.8; for cat pleurae, post mortem, pH = 4.3; for dog pleurae, post mortem, pH = 5.0; for lean and fat pericardia, post mortem, pH = 5.1. The mean reversal point of the two human pericardia was about pH = 5.0. Reversal points determined with buffers containing only monovalent anions are somewhat higher (less acid), as will be shown later. The bearing of these data on the question of the chemical composition of the surfaces of the fat cells of the serous membranes is discussed. Briefly, it is believed that proteins are probably present in important amount in these cell surfaces. PMID- 19872146 TI - THE LOCOMOTION OF LIMAX : II. VERTICAL ASCENSION WITH ADDED LOADS. AB - In Limax the lifting of additional loads during vertical ascension does not alter the law of linear proportionality between speed and frequency of pedal waves, or that between speed and dimensions of the single waves; for equal velocities of progression these quantities are the same, regardless of the mass lifted. The pedal organ of the slug, although under the control of central impulses, is thus essentially an independent effector. PMID- 19872147 TI - TEMPORARY ABOLITION OF PHOTOTROPISM IN LIMAX AFTER FEEDING. AB - When fed upon cooked potato the slug Limax maximus becomes for a day or more indifferent to light-its natural negative phototropism is suppressed. This effect is not produced by raw potato or other diets; it can be duplicated by injection of sugar solutions into the stomach or into the body fluids, and seems to be due to sugar absorbed during the digestion of the cooked starch. The fact is of interest particularly for the suggestion which it affords as to the explanation of fluctuations in conduct. PMID- 19872148 TI - CRITICAL THERMAL INCREMENTS FOR RHYTHMIC RESPIRATORY MOVEMENTS OF INSECTS. AB - The rhythm of abdominal respiratory movements in various insects, aquatic and terrestrial, is shown to possess critical increments 11,500+/- or 16,500+/- calories (Libellula, Dixippus, Anax). These are characteristic of processes involved in respiration, and definitely differ from the increment 12,200 calories which is found in a number of instances of (non-respiratory) rhythmic neuromuscular activities of insects and other arthropods. With grasshoppers (Melanoplus), normal or freshly decapitated, the critical increment is 7,900, again a value encountered in connection with some phenomena of gaseous exchange and agreeing well with the value obtained for CO(2) output in Melanoplus. It is shown that by decapitation the temperature characteristic for abdominal rhythm, in Melanoplus, is changed to 16,500, then to 11,300-depending upon the time since decapitation; intermediate values do not appear. The frequency of the respiratory movements seems to be controlled by a metabolically distinct group of neurones. The bearing of these results upon the theory of functional analysis by means of temperature characteristics is discussed, and it is pointed out that a definite standpoint becomes available from which to attempt the specific control of vital processes. PMID- 19872149 TI - THYROXIN AS A DEPRESSANT OF THE DIVISION RATE OF PARAMECIUM. AB - In concentrations of 1:10(4), 1:10(5), 1:10(6), in alkaline solution with a hydrogen ion concentration approximating that characteristic of normal human blood, thyroxin acts like total thyroid in accelerating certain metabolic processes in Paramecium, notably those connected with the phenomena of excretion. Unlike total thyroid, thyroxin depresses the division rate of Paramecium, the degree of depression varying directly with its concentration. This depression of the division rate is due to the action of the thyroxin directly on Paramecium, not to a modification of the food supply. PMID- 19872150 TI - THE RELATION OF THE STABILITY OF PROTOPLASMIC FILMS IN NOCTILUCA TO THE DURATION AND INTENSITY OF AN APPLIED ELECTRIC POTENTIAL. AB - 1. The experiments demonstrate that when a constant electric potential of sufficient intensity is applied to Noctiluca, the protoplasmic films which represent a part of the visible continuous phase of the cytoplasm and plasma membrane at the surface of the cell, become unstable and break down, thus releasing the acid contents of one of the internal discontinuous phases present in the cytoplasm of Noctiluca. This process which occurs first at anode then at the cathode side of the cell, appears to be a selective deemulsification or coalescence similar to that at the surface of an emulsion having a viscous continuous phase. 2. The experiments demonstrate that Nernst's equation See PDF for Equation which expresses approximately the relation of duration and intensity of a constant electric current to threshold stimulation of striated muscle, applies equally well to the process of anodal coalescence in Noctiluca. 3. Anodal and cathodal coalescence have different thresholds, due to the fact that the semipermeable plasma film at the surface of the cell is asymmetric with respect to the direction of the applied current. Attention is called to the possible relation between this phenomenon and the conditions occurring at the synapse between neurons. 4. The stability of the protoplasmic films in relation to the applied electric potential is greater in young cells than in old cells, or in other words the threshold intensity of the stimulus is higher for young than for old cells. 5. Attention is called to the occurrence in the same cell of different receptor-affector mechanisms having a corresponding difference in intensity threshold when an electric current is acting as a stimulus. PMID- 19872151 TI - FACTORS AFFECTING TRANSMISSION AND RECOVERY IN THE PASSIVE IRON NERVE MODEL. AB - 1. The speed of transmission of the activation wave along passive iron wires enclosed in glass tubes containing dilute (70 per cent) nitric acid increases with the conductivity (sectional area) of the column of electrolyte but at a slower rate. The speed is closely proportional to the square root of the conductivity See PDF for Equation. The reasons for this relationship are discussed and an explanation is proposed. 2. The recovery of transmissivity after the passage of an activation wave is gradual and follows a characteristic course. After an interval of partial or decremental transmission (having a high temperature coefficient and lasting several minutes at 20 degrees ), the wire recovers its power of transmitting an activation wave for an indefinite distance. In such a recovered wire the speed of transmission is at first slow and increases by degrees up to a maximum, the increase following a curve apparently of the type v(t) = v(0) (1 - e(_kt)). The approximate time required to attain this maximum (corresponding to complete recovery) at the different temperatures is 15 to 20 minutes at 20 degrees , 30 to 45 minutes at 15 degrees , ca. 60 minutes at 10 degrees , and 90 minutes or more at 5 degrees . 3. The character of the curve of recovery (the curve relating speed of transmission to interval since previous activation) agrees with the assumption that the increase in speed depends on a progressive chemical change in the molecules forming the passivating film, this change involving the transformation of (relatively) nonreactive into reactive molecules and following the course of a monomolecular reaction. 4. The temperature coefficient of the speed of transmission (between 5 degrees and 20 degrees ) is low, of the order Q(10) = 1.3 to 1.6. That of the rate of recovery, on the contrary, is high (Q(10) = ca. 3). The parallel to the conditions in nerve and other transmitting protoplasmic systems is pointed out and discussed. 5. Passive wires enclosed in acid-containing continuous and interrupted glass tubes immersed in a large volume of acid exhibit characteristic phenomena of distance action; under appropriate conditions the velocity of transmission of the activating influence between different areas may thus be greatly increased. Characteristic instances are cited and some possible physiological parallels are pointed out. PMID- 19872152 TI - SYMBIOSIS BETWEEN CHLORELLA SP. AND AZOTOBACTER CHROOCOCCUM AND NITROGEN FIXATION. PMID- 19872153 TI - THE ACID AGGLUTINATION OF MIXTURES OF OPPOSITELY CHARGED BACTERIAL CELLS. PMID- 19872154 TI - THE GROWTH OF DUCKWEEDS IN MINERAL NUTRIENT SOLUTIONS WITH AND WITHOUT ORGANIC EXTRACTS. AB - 1. Detmer's solution and a modified Knop's solution are unfavorable culture media for the growth of Spirodela polyrhiza. 2. When the modified Knop's solution was diluted to 10 times its volume, Spirodela polyrhiza and Lemna valdiviana grew and reproduced for periods of 26 months and 21 months, respectively. 3. Growth in the dilute Knop's solution, which alone can support the growth of Spirodela indefinitely, was considerably stimulated over a period of 23 days by adding to every liter the water-soluble material of 0.4 gm. autolyzed yeast, or the material of 2.5 gm. peat soluble in a 1 per cent solution of NaHCO(3). 4. The nature of the stimulus or of the protection afforded by the organic material is as yet unknown. 5. The necessity of organic accessory foods (auximones) in the nutrition of green plants cannot be accepted as an established fact. PMID- 19872155 TI - METABOLISM DURING EMBRYONIC AND METAMORPHIC DEVELOPMENT OF INSECTS. AB - 1. For species of insects that deposit their eggs on foliage, as Leptinotarsa decemlineata, Crioceris asparagi, and Anasa tristis, the rates of metabolism as measured by the CO(2) output or the oxygen intake indicate, during embryonic development, a short formative period, followed by a very active extended growth. Those species that deposit their eggs in the soil, as Cotinis nitida and Popillia japonica, show that the formative period is greatly extended and the growth period similarly lengthened. 2. It has been shown from metabolism experiments that intensive histolysis occurs during the prepupal period and becomes less intensive during pupal development. 3. Metabolism experiments show a greater amount of energy change during embryonic development as compared to the energy developed during metamorphosis. This is shown by the greater CO(2) output and by the oxygen intake. 4. Low respiratory quotients, varying from 0.42 to 0.71, have been obtained during the embryonic and pupal development of insects, resembling similar low quotients obtained with hibernating forms. 5. Changes from a neutral to an acid reaction (pH 6.8 to 5.9) have been observed to take place in some species during prepupal and early pupal development. As metamorphosis is completed a converse change occurs (pH 5.9 to 6.8). Changes in pH from an acid to neutral reaction were also observed to take place in some species, as Cotinis nitida and Hylemyia cilicrura, during embryonic development. PMID- 19872156 TI - NEUROID TRANSMISSION IN CILIATED EPITHELIUM. AB - Evidence from several sources indicates that there is present in certain types of ciliated tissue a primitive form of conduction regulating the rate of beat of the cilia. (Kraft, 1890; Engelmann, 1898). A similar type of conduction has been observed by Parker (1910) in the sponge Stylotella. In the foregoing experiments a study was made of such conduction in the ciliated tissue of the gills of the clam Unio. Observations were made on the effects of temperature changes on the rate of beat of cilia adjacent to areas not themselves directly influenced. The following results were obtained. 1. The transmission through the gill of the effects of warmth applied locally is apparent through increased rate of ciliary beat on adjacent gill tissue in all directions from the region of application. Effects are not observed laterally at a distance greater than 9 to 11 mm. from the nearest edge of the stimulated area. The narrowness of the gill makes it impossible to determine the vertical limits of the transmission. 2. Effects of low temperatures are not observable beyond the limits of the region of direct application. These results differ from those of Kraft in tissue from the frog's pharynx, where conduction was shown to take place only down a row of beating cilia. On the other hand they agree with his results in indicating that the effects of warmth only are transmitted. The phenomenon might be explained by the stimulating effect of the action current of the directly excited cilia on the neighboring relatively quiet cilia. A similar explanation has been offered by Lillie for waves of coordinated beating in the rows of swimming plates of ctenophores. Such an explanation, though in accord with the work on Unio, is inconsistent with certain of the observations of Kraft on the tissue from the frog's pharynx. PMID- 19872157 TI - ON THE IMPORTANCE OF MAINTAINING CERTAIN DIFFERENCES BETWEEN CELL SAP AND EXTERNAL MEDIUM. AB - A striking difference exists between the internal and external solution in the case of Valonia macrophysa. If this difference is abolished by placing cells in their own sap most of them quickly die. There is some ground for believing that the maintenance of differences between the sap and the external medium is of importance for vital processes. The sap of Valonia macrophysa is not a balanced solution in the ordinary sense and the question may be raised whether in general the interior of the cell requires a balanced solution in order to maintain life: or it may be that we must distinguish between internal and external balanced solutions. PMID- 19872158 TI - TEMPERATURE CHARACTERISTIC FOR HEART RHYTHM OF THE SILKWORM. AB - The critical thermal increment for the reaction controlling the frequency of the heart beat in mature silkworms is 12,200 calories. This determination agrees quantitatively with the increment deduced for other activities of arthropods in which the rate of central nervous discharge is believed to be the controlling element. PMID- 19872159 TI - THE TEMPERATURE CHARACTERISTIC FOR PHARYNGEAL BREATHING RHYTHM OF THE FROG. AB - The frequency of the pharyngeal respiratory rhythm of frogs exhibits a critical thermal increment micro = 8,800 calories. At about 15 degrees irregularities are apparent, which may be reduced by continued adaptation to room conditions. The frequency depends upon a process possibly synaptic in locus and apparently belonging among the group of respiratory reactions. Its temperature characteristic sharply separates this process from those reactions known to be catalyzed by H ion. PMID- 19872160 TI - PULSATION OF THE CONTRACTILE VACUOLE OF PARAMECIUM AS AFFECTED BY TEMPERATURE. AB - 1. The rate of pulsation of the anterior contractile vacuole of Paramecium caudatum under chloretone anesthesia has been determined over a range of temperatures from 9-31 degrees C. It has been found that the rate is a logarithmic function of the temperature according to the Arrhenius equation. From 9-16 degrees the temperature characteristic (micro) has the value 25,600; from 16 22 degrees it is 18,900; and from 22-31 degrees it becomes 8,600. 2. It is concluded that there are at least three underlying reactions responsible for pulsation, the rates of which vary. Which reaction becomes the limiting one depends upon the range of temperature considered. 3. It does not appear that oxidative processes alone determine the rate of pulsation, although they may be of fundamental importance. PMID- 19872161 TI - THE MECHANISM OF CHANGE IN RESISTANCE OF ERYTHROCYTES TO HYPOTONIC SALT SOLUTIONS. AB - Ashby's work on the effects of KCl and NaCl on the resistance to hypotonic hemolysis of K(*)-rich and K(*)-poor erythrocytes has been repeated with great attention to purity of materials and refinement of technique. The results fail to agree with those of Ashby. 1. KCl produces greater loss in resistance to hypotonic hemolysis than does NaCl, irrespective of the species of the animal from which the cells are taken. 2. While cases of an increase in resistance have been encountered in my experiments, they are either very slight, or else the particular determination is subject to very great uncertainty. The great increases in resistance found by Ashby are not even approached in any of the present series of experiments. 3. Ashby's generalization that KCl and NaCl have opposite effects on red blood cells, and that the sense of these effects depends on whether the cell is K(*)-rich or K(*)-poor is not substantiated. PMID- 19872162 TI - HYDROGEN ION CONCENTRATIONS IN THE BLOOD OF INSECTS. AB - The range of pH values for the blood of grasshoppers and of houseflies is 7.2 to 7.6. The range of values for roaches is 7.5 to 8.0. The range for Malacosoma americanum is 6.4 to 7.4; and the range for Bombyx mori is 6.4 to 7.2. From the work of other investigators and from the writer's results, it is apparent that the pH of insect blood, in general, may vary between 6.4 and 8.0. In the forms observed no correlation exists between blood pH and age, nor between pH and metamorphosis. PMID- 19872163 TI - A TEST FOR DIFFUSIBLE IONS : II. THE IONIC NATURE OF PEPSIN. AB - 1. The distribution of pepsin between particles of gelatin or coagulated egg albumin and the outside solution has been found to be equal to the distribution of chloride or bromide ion under the same conditions. This is the case from pH 1 to 7, and in the presence of a variety of salts. 2. Pepsin is therefore probably a monovalent anion. 3. Under certain conditions the enzyme may be adsorbed on the surface of the protein particles. This reaction is irreversible and is markedly influenced by the presence of low concentrations of electrolytes. PMID- 19872164 TI - FURTHER STUDIES ON NEW METHODS IN THE PHYSIOLOGY AND PATHOLOGY OF PLANTS. PMID- 19872165 TI - AN INTERFACIAL TENSIOMETER FOR UNIVERSAL USE. PMID- 19872166 TI - CONTRASTS IN THE CELL SAP OF VALONIAS AND THE PROBLEM OF FLOTATION. AB - The marine alga Valonia macrophysa contains in its cell sap K and Na in the proportion of 5.72 to 1. In a form regarded as closely related, Valonia ventricosa, growing in similar environment, the ratio of K to Na is as 0.0278 to 1. The former contains no Mg but in the latter it is present. There are other differences in the composition of the sap. These differences bring about a remarkable contrast in behavior in that Valonia ventricosa floats in sea water while Valonia macrophysa sinks. PMID- 19872167 TI - THE PRODUCTION OF CARBON DIOXIDE BY NERVE. AB - 1. A modified Osterhout respiratory apparatus for the detection of CO(2) from nerve is described. 2. The lateral-line nerve from the dogfish discharges CO(2) at first with a gush for half an hour or so and then steadily at a lower rate for several hours. 3. Simple handling of the nerve does not increase the output of CO(2); cutting it revives gush. 4. The CO(2) produced by nerve is not escaping simply from a reservoir but is a true nervous metabolite. 5. The rate of discharge of CO(2) from a quiescent nerve varied from 0.0071 to 0.0128 mg. per gram of nerve per minute and averaged 0.0095 mg. 6. Stimulated nerve showed an increased rate of CO(2) production of 15.8 percent over that of quiescent nerve. 7. The results of these studies indicate that chemical change is a factor in nerve transmission. PMID- 19872168 TI - CARBON DIOXIDE FROM THE NERVE CORD OF THE LOBSTER. AB - 1. The nerve cord of the lobster (Homarus americanus Milne-Edwards) is very delicate and can be used as a living preparation for only a few hours after its removal from the animal. 2. During the first hour or so after removal it discharges CO(2) at a steadily decreasing rate beginning at about 0.20 mg. CO(2) per gram of cord per minute and ending at about 0.07 mg. 3. This discharge exhibits a steady decrease in rate and is not divisible into a period of gush and a period of uniform outflow as with the lateral-line nerve of the dogfish. It terminates in a very few hours with the complete death of the cord. 4. Both handling and cutting the cord temporarily increase the rate of CO(2) output. 5. The stimulated cord discharges CO(2) at a rate about 26 per cent higher than that of the quiescent cord, an increase of about 1.6 times that of the increase observed in the lateral-line nerve of the dogfish under similar circumstances. PMID- 19872169 TI - THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT. AB - The luminescence of Cypridina luciferin-luciferase solution is inhibited by illumination from a carbon arc of 15,000 foot candles in between 1 and 2 seconds. The blue to violet rays are the effective ones, the limits lying somewhere around 4,600 A. u. to 3,800 A. u. The luciferin, not the luciferase, is the substance affected by the light. The effect is partially reversible in the dark. The chemiluminescences obtained by oxidizing phosphorus, lophin, and chlorphenylmagnesium bromide are not inhibited by light under the above conditions. PMID- 19872170 TI - THE EFFECTS OF LIGHT ON LUMINOUS BACTERIA. AB - A conservative statement would therefore be that luminous bacteria show no changes in luminescence as a result of illumination by 625 foot candles for 1.5 minutes when examined 1/200 of a second after exposure, and none as the result of illumination by 15,000 foot candles for 6 minutes when examined (1/6) of a second after exposure. PMID- 19872171 TI - THE RELATIVE IMPORTANCE OF pH AND CARBON DIOXIDE TENSION IN DETERMINING THE CESSATION OF CILIARY MOVEMENT IN ACIDIFIED SEA WATER. AB - The length of time that cilia from the gills of Mylilus continue to beat in acidified sea water depends to some extent on the pH of the solution but to a greater extent on its carbon dioxide tension. PMID- 19872172 TI - CRITICAL INCREMENT FOR OPERCULAR BREATHING RHYTHM OF THE GOLDFISH. AB - The temperature characteristic for opercular breathing rhythm in the quiescent goldfish is 16,500 calories. The reactions governing the frequency of breathing movements in vertebrates appear to be constituent links in the oxidative metabolism of the controlling cells. PMID- 19872173 TI - TEMPERATURE CHARACTERISTIC FOR HEART BEAT FREQUENCY IN LIMAX. AB - The temperature characteristic for the frequency of the heart beat in quiescent Limax maximus is micro = 16,300 calories. This value agrees well with that obtained for certain neurogenic activities of the parietal musculature of this gastropod. PMID- 19872174 TI - THE KINETICS OF STARVATION : II. THE LOSS OF WEIGHT IN PIGEONS SUBSISTING ON WATER ALONE. AB - 1. The loss of weight in pigeons subjected to prolonged starvation on water alone may be accurately represented by an appropriate form of the law of autocatakinesis. 2. This function, within proper limitations, gives a definite indication as to the nature and character of the fundamental reactions involved. In addition, it provides quantitative measures of the relative progress and importance of these reactions. 3. Analytically, the process of starvation consists of two nearly symmetrical cycles, corresponding chemically to the destruction of the carbohydrate-fat reserves and to the decomposition of body protein. 4. A suitable transformation overcoming certain difficulties inherent in the general form of the law is discussed and applied to the data reported. PMID- 19872175 TI - DIURNAL CHANGES IN THE ACIDITY OF BRYOPHYLLUM CALYCINUM. AB - 1. It has been shown that there is a diurnal change in the H ion concentration in Bryophyllum calycinum corresponding approximately to the total acidity changes. The H ion concentration increases at night and decreases during the day. 2. Light is the main factor in causing the decrease in acidity, though it also occurs in the dark. but much more slowly. 3. External oxygen tension does not seem to influence the acidity of the plant, nor does it influence the decomposition of the extracted juice. PMID- 19872177 TI - CRITICAL THERMAL INCREMENTS FOR OXYGEN CONSUMPTION OF AN INSECT, DROSOPHILA MELANOGASTER. AB - The critical thermal increments are calculated for oxygen consumption in the pupae of the "wild type" fruit fly, Drosophila melanogaster, and are found to be of two types: micro = 11,500 and 16,800; above 15 degrees C. the first value is obtained, the second, below this temperature. PMID- 19872176 TI - AN IMPROVED TYPE OF MICROSCOPIC ELECTROCATAPHORESIS CELL. PMID- 19872178 TI - A SIMPLE MICRO VESSEL WITH ELECTRODE FOR DETERMINING THE HYDROGEN ION CONCENTRATION OF SMALL AMOUNTS OF FLUID. AB - A convenient and accurate method is described for the electrometric determination of the hydrogen ion concentration of small amounts of fluid (0.015 to 0.020 cc.). The suitability of such a method for work on insect blood and body fluids is particularly pointed out. PMID- 19872180 TI - JACQUES LOEB. PMID- 19872179 TI - STUDIES ON LUMINOUS BACTERIA : II. THE INFLUENCE OF TEMPERATURE ON THE INTENSITY OF THE LIGHT OF LUMINOUS BACTERIA. AB - 1. A method has been described whereby the intensity of the light of luminous bacteria may be measured in a quantitative manner. 2. It is pointed out that the temperature coefficients for light intensity do not follow the van't Hoff rule, but are higher and vary with each 10 degrees temperature interval. 3. From a comparison with other data it is found that the process is not a simple one, but that the observed curve is the resultant of several reactions which proceed simultaneously. 4. The discrepancies in the temperature coefficients in the neighborhood of the "optimum temperature" may be due to a process of coagulation of the colloidal particles of the enzyme. This coagulation will tend to cause a deviation of the curve away from that normal for chemical reactions. PMID- 19872181 TI - JACQUES LOEB : BIBLIOGRAPHY. PMID- 19872182 TI - THE CHROMOSOMES OF PARTHENOGENETIC FROGS AND TADPOLES. AB - 1. This paper presents cytological observations upon Dr. Loeb's parthenogenetic frog material, with considerations upon the mechanism by which the diploid number and both sexes may be produced. 2. Both sexes of adults and tadpoles are present. 3. The chromosome number is diploid and probably 26 in both sexes. Sex chromosomes cannot be distinguished. 4. The chromosome numbers observed by other authors in parthenogenetic frog material are haploid, diploid, and variable. Their significance is considered. 5. The mechanism producing the diploid number, based on European observations, appears to be a doubling of the haploid number at some time after the second polar body is given off. 6. Overripeness may be a factor in producing both sexes of parthenogenetic frogs and tadpoles. 7. Genetic data indicate that the normal male is digametic and that there are differences of potency between male and female factors for sex which vary in frogs of the two races and in strains within the race. These differences have been interpreted by Witschi as forming a series of multiple allelomorphs. PMID- 19872183 TI - ANDROLETHAL FACTORS IN OENOTHERA. PMID- 19872184 TI - COMPARATIVE STUDIES ON THE METABOLISM OF NORMAL AND MALIGNANT CELLS. PMID- 19872185 TI - IS LIVING PROTOPLASM PERMEABLE TO IONS? AB - The experiments indicate that under normal conditions little or no H(2)S enters the cell sap of Valonia macrophysa except as undissociated molecules. PMID- 19872186 TI - ON THE ACCUMULATION OF DYE IN NITELLA. AB - Living cells of Nitella were placed in different concentrations of brilliant cresyl blue solutions at pH 6.9. It was found that the greater the concentration of the external dye solution, the greater was the speed of accumulation of the dye in the cell sap and higher was the concentration of dye found in the sap at equilibrium. Analysis of the time curves showed that the process may be regarded as a reversible pseudounimolecular reaction. When the concentration in the sap is plotted as ordinates and the concentration in the outside solution as abscissae the curve is convex toward the abscissae. There is reason to believe that secondary changes involving injury take place as the dye accumulates and that if these changes did not occur the curve would be concave toward the abscissae. The process may be explained as a chemical combination of the dye with a constituent of the cell. This harmonizes with the fact that the temperature coefficient is high (about 4.9). Various other possible explanations are discussed. PMID- 19872187 TI - THE ACTION OF ALKALIES ON PEPTIDES AND ON KETOPIPERAZINES. AB - 1. The tripeptide glycyl-levo-alanyl-glycine in solution of either one or ten equivalents of alkali does not undergo racemization on standing. 2. The dipeptide levo-alanyl-glycine under the conditions given in (1) does not undergo racemization. 3. In ketopiperazines, levo-alanyl-glycine anhydride and in levo prolyl-glycine anhydride under the influence of dilute alkalies, racemization takes place. 4. Racemization in the present experiments was never complete. The degree of racemization seems to depend, on the one hand, on the stability of the ketopiperazine ring; on the other, on the concentration of the alkali. 5. The significance of these observations will depend on the outcome of the work on a larger number of polypeptides and ketopiperazines. The work is now in progress in this laboratory. PMID- 19872188 TI - THE EXCRETION OF CARBON DIOXIDE BY FROG NERVE. AB - 1. Quiescent sciatic nerve of the frog discharges CO(2) at the average rate of 0.00876 mg. CO(2) per gram of nerve per minute. 2. Sciatic nerve steeped one minute in boiling water discharges CO(2) at first at a low rate and after an hour and a half not at all. 3. Degenerated sciatic nerve discharges CO(2) at a slightly higher rate than normal living nerve does. 4. Connective tissue from the frog discharges CO(2) at an average rate of 0.0097 mg. per gram of tissue per minute. 5. Assuming that a nerve is composed of from one-half to one-quarter connective tissue the CO(2) output from its strictly nervous components is estimated to be at a rate of 0.008 mg. CO(2) per gram of nerve per minute. 6. Stimulated sciatic nerve increases the rate of its CO(2) output over quiescent nerve by about 14 per cent. When this number is corrected for strictly nervous tissue the rate is about 16 per cent. 7. The increased rate of CO(2) production noted on stimulation in normal sciatic nerves was not observed when they were boiled, blocked, or degenerated. It was also not observed with stimulated strands of connective tissue. PMID- 19872189 TI - CONTRIBUTION TO THE THEORY OF PERMEABILITY OF MEMBRANES FOR ELECTROLYTES. AB - From experiments on such membranes as apple skin, parchment paper membrane, and a membrane of completely dry collodion, results have been obtained which could be interpreted by the assumption that these membranes are less permeable for anions than for cations. In parchment paper there is only a relative diminution of the mobility of the anions, in the apple skin and in the dry collodion membrane there is practically no permeability for anions at all. The theory is developed which explains how the decrease or complete lack of mobility of anions influences the electromotive effects of the membrane and the diffusibility of electrolytes across a membrane. The results of the theory are compared with the experimental results. In membranes impermeable for anions the permeability for cations gives the same order of cations as for the mobilities in a free aqueous solution. But the differences of the mobilities are enormously magnified, e.g. the mobilities of H(*) and Li(*), which are in the proportion of about 1:10 in aqueous solution, are in proportion of about 1:900 in the collodion membrane. The general cause for the retardation of ionic mobility within the membrane may be supposed to be the increased friction of the water envelope dragged along by the ion in the capillary canals of the membrane. The difference of the effect on the cations and on the anions may be attributed to the electric charge of the walls of the canals. PMID- 19872190 TI - PROTEIN FILMS ON COLLODION MEMBRANES. AB - 1. Collodion membranes of high permeability were found to adsorb weighable amounts of gelatin and egg albumin from solution at 37 degrees C. 2. The effect of protein concentration could be expressed fairly well by a hyperbolic equation proposed by Langmuir for the adsorption of gases by a plane surface, while the usual parabolic adsorption equation of Freundlich did not fit the results. 3. In comparing this effect with solutions of varying pH, it was found there was a decided maximum of adsorption in solutions of isoelectric protein. The effects of acids and salts on the amount of gelatin adsorbed were like those observed by Loeb on the viscosity of gelatin solutions, but opposite in direction. The effects of pH on the amount of adsorbed gelatin and on the fluidity of the gelatin solutions were nearly parallel. 4. Membranes made impermeable by long drying took up very little or no gelatin from solution. 5. In the case of membranes of varying permeability the maximum amount of adherent gelatin increased with the permeability and thickness of the membranes, and appeared to be, within limits, a linear function of the relative pore surface of the membranes as calculated from Poiseuille's law. 6. The film of gelatin greatly decreased the permeability of the membranes, as measured by the flow of water through them. The relative cross-section of the pore openings, as calculated from the permeability measurements, was a linear function of the amount of adherent gelatin. These results led to the conclusion that the gelatin formed a film inside the pores. PMID- 19872191 TI - STUDIES ON ENZYME ACTION : XXXIII. LIPASE ACTIONS OF EXTRACTS OF THE WHOLE RAT AT DIFFERENT AGES. AB - The ester-hydrolyzing or lipase actions of extracts of whole rats whose ages ranged from 3 days before birth to 3 years 15 days were tested on ten simple esters by the method described in previous papers. The results are presented in the form of curves, both as absolute actions and as relative actions on the different substrates. The "pictures" of the relative actions changed progressively with increasing age of the rat. For the embryo and the youngest rats, the curves approached those given by the Flexner-Jobling rat carcinoma and by a number of tumors of human origin, changing to a type characteristic of the adult rat, and appearing to revert again to some extent to the embryonic type for the oldest rats. The changes in the actions on individual esters and the relative changes in the actions on different esters are discussed in detail. The greatest increases in actions as the rats became older were found with methyl and ethyl butyrates; at the same time that the actions on some of the other esters were also found to change in characteristic ways. Similar experiments with the protease actions of the extracts of whole rats of different ages on three protein preparations did not give differences similar to those found for the lipase actions. The probable reasons for these observed differences in the two sets of enzyme actions are discussed. PMID- 19872193 TI - APPLICATION OF THE THEORY OF QUANTA TO PERIPHERAL VISION. PMID- 19872192 TI - THE TOTAL LUMINOUS EFFICIENCY OF LUMINOUS BACTERIA. AB - Methods are described for measuring the light emitted by an emulsion of luminous bacteria of given thickness, and calculating the light emitted by a single bacterium, measuring 1.1 x 2.2 micra, provided there is no absorption of light in the emulsion. At the same time, the oxygen consumed by a single bacterium was measured by recording the time for the bacteria to use up .9 of the oxygen dissolved in sea water from air (20 per cent oxygen). The luminescence intensity does not diminish until the oxygen concentration falls below 2 per cent, when the luminescence diminishes rapidly. Above 2 per cent oxygen (when the oxygen dissolving in sea water from pure oxygen at 760 mm. Hg pressure = 100 per cent) the bacteria use equal amounts of oxygen in equal times, while below 2 per cent oxygen it seems very likely that rate of oxygen absorption is proportional to oxygen concentration. By measuring the time for a tube of luminous bacteria of known concentration saturated with air (20 per cent oxygen) to begin to darken (2 per cent oxygen) we can calculate the oxygen absorbed by one bacterium per second. The bacteria per cc. are counted on a blood counting slide or by a centrifugal method, after measuring the volume of a single bacterium (1.695 x 10( 12) cc.). Both methods gave results in good agreement with each other. The maximum value for the light from a single bacterium was 24 x 10(-14) lumens or 1.9 x 10(-14) candles. The maximum value for lumen-seconds per mg. of oxygen absorbed was 14. The average value for lumen-seconds per mg. O(2) was 9.25. The maximum values were selected in calculating the efficiency of light production, since some of the bacteria counted may not be producing light, although they may still be using oxygen. The "diet" of the bacteria was 60 per cent glycerol and 40 per cent peptone. To oxidize this mixture each mg. of oxygen would yield 3.38 gm. calories or 14.1 watts per second. 1 lumen per watt is therefore produced by a normal bacterium which emits 14 lumen-seconds per mg. O(2) absorbed. Since the maximum lumens per watt are 640, representing 100 per cent efficiency, the total luminous efficiency if .00156. As some of the oxygen is used in respiratory oxidation which may have nothing to do with luminescence, the luminescence efficiency must be higher than 1 lumen per watt. Experiments with KCN show that this substance may reduce the oxygen consumption to 1/20 of its former value while reducing the luminescence intensity only (1/4). A partial separation of respiratory from luminescence oxidations is therefore effected by KCN, and our efficiency becomes 5 lumens per watt, or .0078. This is an over-all efficiency, based on the energy value of the "fuel" of the bacteria, regarded as a power plant for producing light. It compares very favorably with the 1.6 lumens per watt of a tungsten vacuum lamp or the 3.9 lumens per watt of a tungsten nitrogen lamp, if we correct the usual values for these illuminants, based on watts at the lamp terminals, for a 20 per cent efficiency of the power plant converting the energy of coal fuel into electric current. The specific luminous emission of the bacteria is 3.14 x 10(-6) lumens per cm(2). One bacterium absorbs 215,000 molecules of oxygen per second and emits 1,280 quanta of light at lambda(max) = 510micromicro. If we suppose that a molecule of oxygen uniting with luminous material gives rise to the emission of 1 quantum of light energy, only 1/168 of the oxygen absorbed is used in luminescence. On this basis the efficiency becomes 168 lumens per watt or 26.2 per cent. PMID- 19872194 TI - THE INFLUENCE OF ELECTROLYTES UPON THE ELECTROPHORETIC MIGRATION OF BACTERIA AND OF YEAST CELLS. AB - 1. It seems first of all clear from our results that the effect of electrolytes upon electrophoretic charge is essentially the same, whether one is dealing with silica dust, bacteria, or yeast cells, although certain quantitative differences appear which will later be discussed. 2. The normal negative charge on the suspended particles appears to be slightly increased by very low concentrations of electrolytes, markedly so in the case of yeast cells. Increase in charge due to minimal concentrations of electrolytes has been recorded by Loeb (1922) for collodion particles. 3. Higher concentrations of electrolytes cause a marked and progressive decrease in negative charge, sometimes leading to an isopotential condition and sometimes to a complete reversal of charge with active migration toward the cathode. This effect is apparently due to the cation alone and increases with the valency of the cation, except that the H ion shows specially marked activity, between that of bivalent and trivalent ions. Since NaOH behaves like an ordinary univalent salt, increased alkalinity of a solution does not further depress the charge already depressed by salts; but, since the H ion is much more active than other univalent or bivalent ions, increased acidity does cause a further progressive depression of charge, even in salt solutions. Certain electrolytes appear to show individual peculiarities due to something else than their valency. Thus KCl for example is distinctly more effective than NaCl. Sodium chloride in general appears to exert less influence upon electrophoretic charge, either in low or high dilution, than do other compounds of univalent ions studied. This depressing effect of moderately high concentrations of electrolytes is much less marked with yeast cells than with Bacterium coli. Silica dust is still less affected by monovalent and bivalent ions than are the yeast cells but appears to be more affected than either yeast or Bacterium coli by AlCl(3). 4. Very high concentrations of AlCl(3) (above 10(-2)M) show a third effect, a decrease of the positive charge produced by concentrations of moderate molar strength. This is analogous to phenomena observed for trivalent salts by Northrop and De Kruif (1921-22) and for acid by Winslow, Falk, and Caulfield (1923-24). 5. Organic substances, such as glucose, glycerol, and saponin produce no effect on electrophoretic velocity until they reach a concentration at which viscosity changes are involved. 6. The first two results observed,-(a) the increase in charge as a result of slight additions of electrolytes, and (b) the marked decrease in charge with further concentration of electrolytes, depending on the valency of the cation, so far as vegetable cells are concerned, are entirely in accord with the theory of the Donnan equilibrium as worked out by Loeb (1922). We might assume in explaining such phenomena that the plant cell contains a certain proportion of unbound protein material and that the first modicum of cation which enters the cell is bound by the protein, leading to an increase in the relative negative charge of the cell as compared with its menstruum, while subsequent increments of cation remain unbound in the cell and thus lower its charge. When we find, however, that the same phenomena are apparent with collodion particles, as shown by Loeb, and with silica dust, it seems difficult to apply such a theory, involving the conceptions of a permeable membrane and unbound organic compounds. Loeb (1923-24) suggests that the primary increase may be due to an aggregation of anions in the part of the electrical double layer adjacent to the suspended particles; but why there should be first an aggregation of anions and later (with increasing concentration) an aggregation of cations, is not easy to conceive. The third result,-the reversion to a more negative charge in the presence of a marked excess of trivalent ions,-is again difficult to explain. Loeb, in this connection, postulates the existence of complex ion-protein compounds, which can scarcely be assumed in the case of the silica particles. PMID- 19872195 TI - THE INFLUENCE OF ALCOHOL UPON THE GROWTH OF SEEDLINGS. AB - In this paper it is shown that if the dry seeds of the cantaloupe (Cucumis melo) are soaked for 3 hours in solutions of ethyl alcohol of concentration ranging from 2 to 16 per cent by volume, and then germinated and grown in distilled water in the dark, the total growth attained is greater by amounts ranging from 9 to 35 per cent than is that made by seeds treated in every way identically except that they are initially soaked in distilled water instead of alcohol. It is shown that this result is not due simply to differences in osmotic pressure in the different alcohol solutions. It is probably due to a simple selective action of the alcohol which eliminates the constitutionally weak and defective seeds. PMID- 19872196 TI - TIME RELATIONS OF GROWTH : I. GENETIC GROWTH CONSTANTS OF ANIMALS. AB - This paper is the first in a series proposing to evaluate growth constants from the viewpoint of and by the methods of the physical chemist. After discussing the physicochemical conception of growth, tentative numerical values of two growth constants are given for several species of animals including man, and the methods of computation are discussed in detail. PMID- 19872197 TI - GEOTROPISM AND MUSCLE TENSION IN HELIX. AB - 1. The snail Helix aspersa Muller, is negatively geotropic during the daytime, but positive or indifferent at night. 2. The precision of geotropic orientation is a function of the gravity component acting on the body. 3. The rate of geotropic locomotion is also determined by the gravity component (sine of the angle of inclination). 4. The rate of upward movement is increased 1.51 times at 45 degrees inclination by loading the snail with one-half its weight. No such increase is seen in loaded snails creeping on a horizontal surface. 5. Moderate centrifugation results in orientation and locomotion towards the center of rotation. 6. A response analogous to the homostrophic reflex occurs when a backward pull to right or to left is exerted on the shell. Bilaterally equal tension applied to the shell causes locomotion along a path parallel and opposite to the direction of the pull. 7. All the observations go to show that the stimulus for geotropic orientation and locomotion is tension of the body muscles produced by the downward pull of gravity, and that the stimulus is received by the proprioreceptors of these muscles. Otolith apparatus and analogous organs, when present, may assist in the response, but they do not seem to be requisite in all cases. Since the precision of orientation and the rate of locomotion are functions of the gravity component acting on the body, the muscle tension theory of the geotropic reactions accords fully with Loeb's tropism doctrine for animals. PMID- 19872198 TI - FERMENTWIRKUNG UND IONENANTAGONISMUS. AB - 1. Invertase ist salzempfindlich nur in Gegenwart von Kolloiden, wie Gelatine, Albumin, Globulin, Lecithin; ihre Aktivitat wird dabei durch die Salze herabgesetzt. 2. An den Komplexen Invertase-Globulin und Invertase-Lecithin lasst sich eine Ionenaequilibrierung von der Art des physiologischen Kationenantagonismus nachweisen; Na und K einerseits, Mg, Ca, Sr, Ba, Al, La andererseits hemmen in gewissen Konzentrationsverhaitnissen einander, so dass bei Einhaltung dieser Verhaltnisse die Invertase optimal wirkt. 3. Die Salzhemmung und der Kationenantagonismus fehlen auf der sauren Seite des isoelektrischen Punkts des Globulins und Lecithins. PMID- 19872199 TI - STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI : IV. THE TRANSPORT NUMBERS OF THE COMPOUNDS OF CASEIN WITH THE ALKALI EARTH ELEMENTS. AB - 1. Data from the results of transference experiments on solutions of the alkaline earth caseinates are given. 2. The data support the idea that part of the alkaline earth element is held by the casein in the form of complex ions. 3. Grounds are given for believing that the complex anions have a definite composition. PMID- 19872200 TI - A STUDY OF THE CIRCULATION, BLOOD PRESSURE, AND RESPIRATION OF SHARKS. AB - The average branchial blood pressure in sand sharks was 32 mm. of mercury. The highest recorded in a resting animal was 43 mm. The average dorsal or systemic pressure was 23.3 mm.; highest 30 mm. The ratio of branchial to systemic pressure is about 3 to 2. The pressure in both systems keeps up well under trauma; but under experimental conditions, with or without manipulation of viscera, slowly falls after several hours. It rises with muscular effort, and a long rise usually follows stoppage of struggling. It rises when sodium carbonate is injected. The adrenalin curve resembles that in a mammal. Spontaneous rises and falls not attributable to the heart occur. Light in some animals increases blood pressure. It is suspected that these fishes have a vasomotor apparatus. The heart rate except after trauma is practically always the same as the respiration rate, and there is some reason for believing that the heart rate is determined by the respiration rate. When not in step with respiration, the heart is slower and often in a simple ratio with respiration. The heart is inhibited by all sorts of stimuli applied practically anywhere (except to the liver?). This effect is abolished by atropin. Respiration is faster in small animals and averages 24 per minute. Respiration slowly decreases in strength with little change in rate. Usually respiration ceases long before the heart stops. PMID- 19872201 TI - THE EFFECT OF EXPOSURE PERIOD AND TEMPERATURE ON THE PHOTOSENSORY PROCESS IN CIONA. AB - 1. Experiments are presented which show that the latent period in the photosensory response of Ciona is inversely proportional to the duration of the exposure period to light. From this it is found that the velocity of the chemical reaction which determines the latent period is directly proportional to the concentration of photochemical products formed during the exposure period. This is interpreted as showing that the two processes form a coupled photochemical reaction, of which the secondary reaction proceeds only in the presence of products from the primary reaction. This coupling may be a catalysis or a direct chemical relation. 2. Further experiments show that the relation between temperature and the latent period is accurately described by the Arrhenius equation in which micro = 16,200. The precise numerical value of micro tentatively identifies the latent period process as an oxidation reaction which is catalyzed by iron. 3. The photocatalytic properties of certain iron compounds are used as a model for the coupled photochemical reaction suggested for the photosensory mechanism of Ciona and Mya. PMID- 19872202 TI - THE PHOTOLYSIS OF THE LUMINESCENT GRANULES OF EUCHARIS MULTICORNIS. AB - 1. By means of a photographic method a study was made of the photolytic effect of light on the luminescent granules of Eucharis multicornis. 2. The photolytic reaction conforms to the Bunsen-Roscoe law. 3. The velocity of the photolytic reaction is not increased by a rise in temperature. 4. The photolytic reaction proceeds as a first order reaction. PMID- 19872203 TI - ON THE NATURE OF DIPHTHERIA TOXIN. PMID- 19872204 TI - THE SWELLING AND OSMOTIC PRESSURE OF GELATIN IN SALT SOLUTIONS. AB - 1. The swelling and the osmotic pressure of gelatin at pH 4.7 have been measured in the presence of a number of salts. 2. The effect of the salts on the swelling is closely paralleled by the effect on the osmotic pressure, and the bulk modulus of the gelatin particles calculated from these figures is constant up to an increase in volume of about 800 per cent. As soon as any of the salts increase the swelling beyond this point, the bulk. modulus decreases. This is interpreted as showing that the elastic limit has been exceeded. 3. Gelatin swollen in acid returns to its original volume after removal of the acid, while gelatin swollen in salt solution does not do so. This is the expected result if, as stated above, the elastic limit had been exceeded in the salt solution. 4. The modulus of elasticity of gelatin swollen in salt solutions varies in the same way as the bulk modulus calculated from the osmotic pressure and the swelling. 5. The increase in osmotic pressure caused by the salt is reversible on removal of the salt. 6. The observed osmotic pressure is much greater than the osmotic pressure calculated from the Donnan equilibrium except in the case of AlCl(3), where the calculated and observed pressures agree quite closely. 7. The increase in swelling in salt solutions is due to an increase in osmotic pressure. This increase is probably due to a change in the osmotic pressure of the gelatin itself rather than to a difference in ion concentration. PMID- 19872205 TI - THE ACTIVATION OF STARFISH EGGS BY ACIDS. AB - 1. Exposure of unfertilized starfish eggs to dilute solutions of weak acids (fatty acids, benzoic and carbonic acids) in isotonic balanced salt solution causes complete activation with the proper durations of exposure. For each acid the rate of activation (reciprocal of optimum duration) varies with concentration and temperature; at a given temperature and within a considerable range of concentrations (e.g. 0.00075 to 0.004 M for butyric acid), this rate is approximately proportional to concentration. We may thus speak of a molecular rate of action characteristic of each acid. 2. In general the molecular rate of action increases with the dissociation constant and surface activity of the acids. In the fatty acid series (up to caproic), formic acid has the most rapid effect, acting about four times as rapidly as acetic; for the other acids the order is: acetic = propionic <== butyric < valeric < caproic. Carbonic acid acts qualitatively like the fatty acids, but its molecular rate of action is only about one-fourteenth that of acetic acid. 3. Hydrochloric and lactic acids are relatively ineffective as activating agents, apparently because of difficulty of penetration. Lactic acid is decidedly the more effective. The action of both acids is only slightly modified by dissolving in pure (isotonic NaCl and CaCl(2)) instead of in balanced salt solution. 4. The rate of action of acetic acid, in concentrations of 0.002 M to 0.004 M is increased (by 10 to 20 per cent) by adding Na-acetate (0.002 to 0.016) to the solution. The degree of acceleration is closely proportional to the estimated increase in undissociated acetic acid molecules. Activation thus appears to be an effect of the undissociated acid molecules in the external solution and not of the ions. Acetate anions and H ions acting by themselves, in concentrations much higher than those of the solutions used, have no activating effect. The indications are that the undissociated molecules penetrate rapidly, the ions slowly. Having penetrated, the molecules dissociate inside the egg, yielding the ions of the acid. 5. When the rate of activation is slow, as in 0.001 M acetic acid, the addition of Na-acetate (0,008 M to 0.016 M) has a retarding effect, referable apparently to the gradual penetration of acetate ions to the site of the activation reaction with consequent depression of dissociation. 6. An estimate of the C(H) of those solutions (of the different activating acids) which activate the egg at the same rate indicates that their H ion concentrations are approximately equal. On the assumptions that only the undissociated molecules penetrate readily, and that the conditions of dissociation are similar inside and outside the egg, this result indicates (especially when the differences in adsorption of the acids are considered) that the rate of activation is determined by the C(H) at the site of the activation reaction within the egg. PMID- 19872206 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : I. THE ACTION OF THE CHLORIDES OF NA, K, CA, AND MG ON THE PROTOPLASM OF AMOEBA PROTEUS. AB - By means of micro-dissection and injection Amoeba proteus was treated with the chlorides of Na, K, Ca, and Mg alone, in combination, and with variations of pH. I. The Plasmalemma. 1. NaCl weakens and disrupts the surface membrane of the ameba. Tearing the membrane accelerates the disruption which spreads rapidly from the site of the tear. KCl has no disruptive effect on the membrane but renders it adhesive. 2. MgCl(2) and CaCl(2) have no appreciable effect on the integrity of the surface membrane of the ameba when applied on the outside. No spread of disruption occurs when the membrane is torn in these salts. When these salts are introduced into the ameba they render the pellicle of the involved region rigid. II. The Internal Protoplasm. 3. Injected water either diffuses through the protoplasm or becomes localized in a hyaline blister. Large amounts when rapidly injected produce a "rushing effect". 4. HCl at pH 1.8 solidifies the internal protoplasm and at pH 2.2 causes solidification only after several successive injections. The effect of the subsequent injections may be due to the neutralization of the cell-buffers by the first injection. 5. NaCl and KCl increase the fluidity of the internal protoplasm and induce quiescence. 6. CaCl(2) and MgCl(2) to a lesser extent solidify the internal protoplasm. With CaCl(2) the solidification tends to be localized. With MgCl(2) it tends to spread. The injection of CaCl(2) accelerates movement in the regions not solidified whereas the injection of MgCl(2) induces quiescence. III. Pinching-Off Reaction. 7. A hyaline blister produced by the injection of water may be pinched off. The pinched-off blister is a liquid sphere surrounded by a pellicle. 8. Pinching off always takes place with injections of HCl when the injected region is solidified. 9. The injection of CaCl(2) usually results in the pinching off of the portion solidified. The rate of pinching off varies with the concentration of the salt. The injection of MgCl(2) does not cause pinching off. IV. Reparability of Torn Surfaces. 10. The repair of a torn surface takes place readily in distilled water. In the different salt solutions, reparability varies specifically with each salt, with the concentration of the salt, and with the extent of the tear. In NaCl and in KCl repair occurs less readily than in water. In MgCl(2) repair takes place with great difficulty. In CaCl(2) a proper estimate of the process of repair is complicated by the pinching-off phenomenon. However, CaCl(2) is the only salt found to increase the mobility of the plasmalemma, and this presumably enhances its reparability. 11. The repair of the surface is probably a function of the internal protoplasm and depends upon an interaction of the protoplasm with the surrounding medium. V. Permeability. 12. NaCl and KCl readily penetrate the ameba from the exterior. CaCl(2) and MgCl(2) do not. 13. All four salts when injected into an ameba readily diffuse through the internal protoplasm. In the case of CaCl(2) the diffusion may be arrested by the pinching off process. VI. Toxicity. 14. NaCl and KCl are more toxic to the exterior of the cell than to the interior, and the reverse is true for CaCl(2) and MgCl(2). 15. The relative non-toxicity of injected NaCl to the interior of the ameba is not necessarily due to its diffusion outward from the cell. 16. HCl is much more toxic to the exterior of a cell than to the interior; at pH 5.5 it is toxic to the surface whereas at pH 2.5 it is not toxic to the interior. NaOH to pH 9.8 is not toxic either to the surface or to the interior. VII. Antagonism. 17. The toxic effects of NaCl and of KCl on the exterior of the cell can be antagonized by CaCl(2) and this antagonism occurs at the surface. Although the lethal effect of NaCl is thus antagonized, NaCl still penetrates but at a slower rate than if the ameba were immersed in a solution of this salt alone. 18. NaCl and HCl are mutually antagonistic in the interior of the ameba. No antagonism between the salts and HCl was found on the exterior of the ameba. No antagonism between the salts and NaOH was found on the interior or exterior of the ameba. 19. The pinching-off phenomenon can be antagonized by NaCl or by KCl, and the rate of the retardation of the pinching-off process varies with the concentration of the antagonizing salt. 20. The prevention of repair of a torn membrane by toxic solutions of NaCl or KCl can be antagonized by CaCl(2). These experiments show directly the marked difference between the interior and the exterior of the cell in their behavior toward the chlorides of Na, K, Ca, and Mg. PMID- 19872207 TI - THE PHYSIOLOGY OF SELF-STERILITY IN PLANTS. PMID- 19872208 TI - TRANSPLANTATION AND POTENTIAL IMMORTALITY OF MAMMALIAN TISSUES. AB - 1. Serial transplantation of tumors made it possible in 1901 and following years to draw the conclusion that various mammalian tissues have potential immortality. Serial transplantations of normal tissues did not succeed at first, because the homoioreaction on the part of the lymphocytes and connective tissue of the host injures the transplant. 2. In continuation of these experiments we found that cartilage of the rat can be transplanted serially to other rats at least for a period of 3 years. At the end of that time great parts of the transplanted cartilage and perichondrium are alive. 3. Not only the cartilage of young rats can be homoiotransplanted, but also the cartilage of very old rats which are nearing the end of life. By using such animals we have been able to obtain cartilage and perichondrium approaching an age of 6 years which is almost double the average age of a rat. 4. We found that cartilage can be homoiotransplanted more readily than other tissues for the following reasons: (a) While in principle the homoioreaction towards cartilage is the same as against other tissues, cartilage elicits this reaction with less intensity; (b) cartilage is better able to resist the invasion of lymphocytes and connective tissue than the majority of other tissues; (c) a gradual adaptation between transplant and host seems to take place in the case of cartilage transplantation, as a result of which the lymphocytic reaction on the part of the host tissue decreases progressively the longer the cartilage is kept in the strange host. 5. At time of examination we not only found living transplanted cartilage tissue, but also perichondrial tissue, which in response to a stimulus apparently originating in the necrotic central cartilage, had been proliferating and replacing it. These results suggest that it may perhaps be possible under favorable conditions to keep cartilage alive indefinitely through serial transplantations. 6. At the same time these experiments permit the analysis of the factors which are favorable or unfavorable to the continued life of the transplants. Favorable factors are: (a) Well preserved perichondrium around transplant; (b) cellular newly formed perichondrial cartilage-though it is doubtful whether such young cartilage cells allow a state of stable equilibrium. Host connective tissue does not invade transplant under these conditions. Unfavorable factors are: (a) Cartilage differentiation and the production of paraplastic substances (hyaline capsules in parts of transplant far removed from vessels and sources of oxygen and food; (b) cartilage necrosis when a still greater distance from nourishment exists; (c) disturbance of equilibrium between host connective tissue and transplant due to above conditions, resulting in (d) attack by host connective tissue on transplanted cartilage, which is the chief danger in the preservation of the life of the whole transplant 7. It is pointed out that also in old age there exist similar problems of disturbances of tissue equilibria, due to degenerative changes in certain parenchymatous structures and to proliferative processes on the part of connective tissue and glia elements together with increase in paraplastic structures. PMID- 19872209 TI - THE RELATIONS OF THE INDIVIDUAL AMPULLAE OF THE SEMICIRCULAR CANALS TO THE INDIVIDUAL EYE MUSCLES : I. THE HORIZONTAL CANALS. AB - 1. The reflex effect of direct mechanical stimulation of the exposed ampulla of the horizontal canal has been graphically recorded for each of the six extrinsic muscles of the eyeball. 2. Stimulation of a horizontal ampulla evokes a strong contraction of the homolateral rectus internus and of the contralateral rectus externus; at the same time the homolateral rectus externus and the contralateral rectus internus relax. 3. A single mechanical stimulus applied to the horizontal ampulla is sometimes followed by a nystagmus resulting from a series of rhythmic contractions of the externus and internus muscles. 4. Excitation of a horizontal ampulla gives rise to weak contractions of the superior and inferior recti and of the two oblique muscles of both eyes, simultaneously with the stronger contractions of the externus and internus respectively. 5. It is pointed out that the small simultaneous contractions of the four muscles just mentioned provide a virtual axis upon which the eyeball rotates. In other words these four act as fixation muscles. 6. It is suggested that some of the abnormal responses to horizontal rotation, seen in clinical cases, are due to the inaction of one or more of the fixation muscles. PMID- 19872210 TI - THE EFFECT OF PURE PROTEIN SOLUTIONS AND OF BLOOD SERUM ON THE DIFFUSIBILITY OF CALCIUM. AB - 1. A comparative study has been made of the diffusibility of calcium in solutions of crystalline egg albumin, serum globulin, and human blood serum. 2. In all three of these solutions, at pH 7.4, molal Ca concentrations within the membrane are greater than the calcium concentrations in the outside solutions, quite in accordance with the Donnan theory. 3. At pH 7.4, the ratio of See PDF for Structure varies directly with the protein concentration whether the solution be one of egg albumin, serum globulin, or blood serum. This is also in accordance with the Donnan theory. 4. On the acid side of the isoelectric point of the proteins, the concentration of Ca outside becomes greater than the concentration in the solution of blood serum or pure protein, as is demanded by the Donnan theory. 5. The magnitude of the Ca ratios on the alkaline and acid sides of the isoelectric points is probably the resultant of the Donnan equilibrium and the formation of complex Ca-protein ions. Northrop and Kunitz have shown the probability of the existence of such ions in the case of Zn(++), K(+), and Li(+), where satisfactory electrodes have been developed for E.M.F. measurements. PMID- 19872211 TI - THE ANALYSIS OF THE GROWTH OF THE NORMAL WHITE MOUSE INTO ITS CONSTITUENT PROCESSES. AB - 1. The several growth-cycles which are distinguishable in the growth of an animal or plant are mutually independent in that they do not share a common catalyser. 2. The growth of the white mouse has been shown to consist of three autocatalytic processes and one "linear process" of weight-accretion. The parameters of these processes have been evaluated for one strain and generation of mice. 3. The first and most extensive autocatalytic process is asymmetrical, being defined by an equation of the type: See PDF for Equation The second and third cycles, which are more rapid and do not begin to affect the growth of the animal until a later stage of development, are symmetrical, being defined by equations of the type: See PDF for Equation 4. The amplitude of the first autocatalytic growth-cycle in the mouse is almost the same in males and females, but the moment of maximum growth-velocity in the female anticipates that in the male, the velocity constant is smaller in the female, and the asymmetry estimated by the magnitude of the constant B, is greater in the female than in the male. 5. The amplitude of the second cycle is almost the same in males and females, but data are as yet lacking which would enable us to ascertain whether the velocity-constant and moments of maximum growth-velocity in this cycle differ in the two sexes or not. 6. The amplitude of the third cycle is much less in the female than in the male, and this difference of amplitude almost wholly accounts for the difference of adult weight in the two sexes. The velocity-constant of the third cycle is, however, greater in the female than in the male. Maximum growth velocity due to this cycle is attained at very nearly the same age in both sexes. 7. The origin of asymmetry in autocatalytic growth-processes is discussed. It is pointed out that asymmetry might originate in a progressive diminution of the velocity-constant. If this is the origin of the asymmetry of the first growth-cycle in the mouse, then it is shown that the velocity constant of autocatalysis in this cycle must be very nearly proportional to the nucleo-cytoplasmic ratio, as estimated by the chemical method of Le Breton and Schaeffer. 8. It is pointed out that no reliable measure of senescent loss of weight is available at present. It is shown that removal or decay of those conditions which initially maintain the separability of the growth cycles which collectively constitute the growth of the white mouse would necessarily result in loss of weight. PMID- 19872212 TI - THE REACTIONS OF CERIANTHUS TO LIGHT. AB - 1. When Cerianthus membranaceus is illuminated upon one side, the animal turns its anterior portion toward the source of light. The number of degrees through which the animal turns is proportional to the logarithm of the intensity of the light. 2. A light intensity of between 250 m.c. and 15,000 m.c. is necessary to cause retraction of the animal. 3. The part of the spectrum which is most effective in causing heliotropic bending of Cerianthus lies between micromicro 510 and micromicro 570. PMID- 19872213 TI - THE METABOLISM OF TUMORS IN THE BODY. PMID- 19872214 TI - RECENT INVESTIGATIONS ON THE AEROBIC AND AN-AEROBIC METABOLISM OF CARBOHYDRATES. PMID- 19872215 TI - THE INFLUENCE OF SALTS UPON THE IONISATION OF EGG ALBUMIN. AB - Introduction. A description is given of the principle followed in the experimental determination of the ionisation of egg albumin, its capacity to combine with acids and bases. Egg albumin is regarded as an ampholyte, and in accordance with J. N. Bronsted's definition of acids and bases, ampholytes are considered as substances capable of both taking up and giving off hydrogen ions. The theoretical treatment of the capacity of ampholytes to combine with acids (and bases) has been carried out on this basis. Section A. Several experimental series are noted, comprising the determination of the activity coefficient of the hydrogen ion (fH) in ammonium chloride solutions of different concentration. Section B. The general method of experimental determination of the ionisation (capacity to combine with adds and bases) of egg albumin in ammonium chloride and potassium chloride solutions is briefly described, and the results of the experiments are compared. Section C. 1). In a brief theoretical survey we have suggested that distinction should be made between isoelectric and isoionic reaction of an ampholyte, the former defined as the hydrogen ion activity (value of paH) at which the mean valency of the ampholyte is 0, the latter as the hydrogen ion activity at which the quantity of acid or base combined with the ampholyte is 0; or, as we prefer to express it, the hydrogen ion activity at which the specific hydrogen ionisation of the ampholyte is 0. If the ampholyte does not combine with other ions than the hydrogen ion, then isoelectric and isoionic reaction coincide. Isoionic reaction is determined by acid-combining experiments. The principle of this determination is briefly described. A theoretical investigation of the alteration with salt concentration of both isoelectric (isoionic) reaction and the shape and direction of the ionisation curves is made, with regard to ampholytes capable only of combining with hydrogen ions, on the basis of the Debye-Huckel formulae and Linderstrom-Lang's theory for the ionisation of polyvalent ampholytes of simple type. It is shown that the salt effect, in accordance with the theory, and in qualitative agreement with the experiments, consists in a turning of the ionisation curves, indicating the relation between the quantity of combined acid (specific hydrogen ionisation) and paH, and the turning of the curves, which leaves the isoelectric reaction unaltered, tends in such a direction that the quantity of combined acid at constant ampholyte concentration and constant pan increases with increasing salt concentration. The possibility of chemical combining of other ions than the hydrogen ion is discussed. 2). Following on 1), a brief survey of the experimental results is given. 3). The isoionic reaction is found from the experimental material and proved to be independent of the ammonium chloride concentration. As the mean of all determinations we have pa(H) (0) = 4.898 (isoionic reaction). The difference between this value and that formerly found for ammonium sulphate solutions (4.844) is discussed. 4). Finally, on the basis of the theory in Section 1), some simple calculations of the ionisation curves for egg albumin are made, and it appears that the theory can reproduce the experimental results in a rough quantitative way when we assume that the egg albumin has a radius of 2.21.10(-7) cm. (answering to a molecular weight of 35,000 in aqueous solution), and contains 30 acid and base groups. PMID- 19872216 TI - THE INFLUENCE OF THE BACKWARD REACTION IN THE PEPTIC HYDROLYSIS OF ALBUMIN. AB - 1. No destruction of pepsin by heat is demonstrable at pH 1.6 until a temperature of 40 degrees C. is exceeded. 2. The influence of the backward reaction in peptic hydrolysis is shown in the diminishing rate at which increasing concentrations of protein are hydrolyzed. 3. The backward reaction causes the optimum for the hydrolysis of higher concentrations of protein to be attained at a lower temperature than with more dilute solutions. 4. The proteose and peptone associated with commercial pepsin retard hydrolysis in the same sense as the products due to the action of the enzyme. PMID- 19872217 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS : VI. THE ACTIVITY COEFFICIENTS OF THE IONS IN CERTAIN OXYHEMOGLOBIN SOLUTIONS. AB - 1. The solvent action of a neutral salt upon a protein, oxyhemoglobin, has been found identical to the solvent action of a neutral salt upon a bi-bivalent or uni quadrivalent compound. 2. The solubility of oxyhemoglobin in phosphate solutions of varying ionic strength has been defined by the equation: log See PDF for Equation in which micro is the ionic strength, and S(0) is the solubility in the absence of salt. 3. The values of S(0) have been calculated to be 12.2, 11.2, and 13.1 gm. per liter respectively at pH 6.4, 6.6, and 6.8. 4. The relatively great solubility of oxyhemoglobin in water has been ascribed to the strong affinity constants for acid and base of certain groups in oxyhemoglobin. 5. The small change in the solubility of oxyhemoglobin effected by neutral salts suggests that but few such groups are dissociated in oxyhemoglobin in the state in which it crystallizes near its isoelectric point. 6. Certain of the other properties of oxyhemoglobin, such as its low viscosity, are considered in the light of its molecular weight and its valence type. PMID- 19872218 TI - MOLECULAR ORIENTATION IN LIVING MATTER. PMID- 19872219 TI - ON THE RESPECTIVE PARTS PLAYED BY NEURAL AND HUMORAL INFLUENCES IN ANIMAL REACTIONS. AB - 1. In the higher animals control of the functions of the body is dual, being partly neural and partly humoral. 2. When the control of any function is single and not dual, it is entirely neural. Exceptions to this statement appear to occur in connexion with the secretion of urine and milk, since these functions have not hitherto been shown to be under direct neural control. The mamma, and perhaps the kidney also, is, however, influenced by certain internal secretions which are themselves subJect both to neural and to humoral control. 3. The functions which are controlled both neurally and humorally are initiated by direct nervous influence: the humoral influence succeeds this. 4. In the lowest organisms possessed of a nervous system there is no evidence of humoral control, and no probability that this could be exercised, since there is no circulatory fluid, and the fluid which bathes the tissue has a composition appreciably the same as that of the environment. 5. It is, therefore, inferred that in all cases in which a dual control exists the neural, which is more rapid in its action, is primary, and the humoral secondary; and that the object of the humoral influence is to continue and prolong the effect of the neural influence, and thus to effect an economy of nervous energy. PMID- 19872220 TI - A CHEMIST'S HOMAGE TO THE WORK OF A BIOLOGIST. PMID- 19872221 TI - THE ORIENTATION OF ANIMALS BY OPPOSED BEAMS OF LIGHT. AB - When orientation is attained under the influence of beams of parallel light opposed at 180 degrees the deflection theta from a path at right angles to the beams is given by tan See PDF for Equation, where I(1) and I(2) are the photic intensities and H is the average angle between the photoreceptive surfaces. This expression is independent of the units in which I is measured, and holds whether the primary photosensory effect is proportional to I or to log I. When photokinetic side-to-side motions of the head occur, H decreases with increasing total acting light intensity, but increases if higher total light intensity restricts the amplitude of random movements; in each case, H is very nearly proportional to log I(1)I(2). For beams of light at 90 degrees , See PDF for Equation. The application of these equations to some particular instances is discussed, and it is shown why certain simpler empirical formulae previously found by others yield fair concordance with the experimental data. The result is thus in complete accord with the tropism theory, since the equations are based simply on the assumption that when orientation is attained photic excitation is the same on the two sides. PMID- 19872222 TI - CONCERNING THE APPLICABILITY OF THERMODYNAMICS TO THE PHENOMENA OF LIFE. PMID- 19872223 TI - THE RELATION OF THE AGE OF THE FEMALE TO CROSSING OVER IN THE THIRD CHROMOSOME OF DROSOPHILA MELANOGASTER. AB - The four methods of examining the relation of amount of multiple crossing over to age of mothers agree in showing that the "internode length" or average distance required for double crossing over has changed in a characteristic fashion, giving an M-shaped curve. These changes have not been independent of changes in total recombination but concomitant with them. However, the changes in recombination percentages were far greater than could be accounted for by change in internode length, and the larger factor must be assumed to be changes in the coefficients of crossing over. The amounts of these changes are greatest for the mid-sections of the chromosome and least for the distal sections. The changes in the two limbs are of like amount for equal distances from the center of symmetry in the distribution of simple and multiple crossing over. PMID- 19872224 TI - STUDIES OF GAS AND ELECTROLYTE EQUILIBRIA IN THE BLOOD : IX. THE DISTRIBUTION OF ELECTROLYTES BETWEEN TRANSUDATES AND SERUM. AB - 1. Analyses have been made of the electrolytes and proteins of serum and transudates from human subjects. 2. The distribution ratios of HCO(3), Cl, Na, and H(+) deviated from unity as predicted by the Gibbs-Donnan law for similar heterogeneous systems. 3. Analyses of serum, and of artificial salt solutions approximating edema fluid in composition, after equilibration across collodion membranes showed distributions similar to those between serum and edema fluid in vivo. PMID- 19872225 TI - EPIDEMIC ENCEPHALITIS AND SIMPLE HERPES. AB - The purpose of this paper is to explain the state of our knowledge of the etiology of epidemic encephalitis, and especially to draw a line of demarcation between the established virus of simple herpes and the hypothetical virus of epidemic encephalitis. It had already been shown that the experimental observations on rabbits do no suffice to prove the identity of the herpes with the encephalitis virus. The discussion of the subject in this paper shows that identity cannot be postulated on the basis of the performed guinea pig experiments. Attention has been drawn to the significant fact that there is lack of harmony in the positive results of those investigators who believe that the incitants of epidemic encephalitis have been discovered. An attempt has been made to attribute some of the discrepancies reported by these investigators either to accidental and contaminating microbic agents, or to the uncovering of virulent agents preexisting in a latent state in the animals employed for inoculation, the existence of which was not previously known or suspected. Since past experience leads us to believe in a single incitant for widespread epidemic diseases, it is probable that, when certainly discovered, the microbe of epidemic encephalitis will prove to be simple and not multiple. The direct corollary to this point of view is that up to the present, the etiology of epidemic encephalitis has not been determined. PMID- 19872227 TI - NOTES ON MICROSPECTRA : I. THE ABSORPTION SPECTRUM OF EUGLENA. PMID- 19872226 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. II. CATABOLISM. CHEMICAL CHANGES IN FERTILE EGGS DURING INCUBATION. SELECTION OF STANDARD CONDITIONS. AB - As this paper goes to press a complete review of the chemistry of the fertile egg will be appearing (19). The author, Mr. J. Needham, was kind enough to allow me to inspect his manuscript and thus avail myself of the comprehensive bibliography and discussion. It is surprising that no biochemists have estimated the changing water content of the egg during incubation. Many of the analyses reported in Needham's review were expressed in per cent of total weight or per cent of dry solid, and consequently are of questionable value, since these latter functions are themselves changing; the former due to water evaporation and the latter through the addition of shell constituents and the burning of oxidizable organic compounds. Moreover, there has been no statistical treatment of the results, and the reliability of the average, figures obtained has consequently been difficult to estimate. Tangl's work, quoted throughout this paper, except for its lack of statistical treatment is more enlightening. However, his concept of the so called "Energy of Embryogenesis" which he propounds, seems to me misleading and unwarranted. What Tangl measured was the amount and the caloric value of the solid material burned and thus the quantity of energy lost during the embryonic period. The latter is equivalent to the usual measurements of catabolism. In the case of the embryo it is not basal metabolism which is being estimated, since the conditions are not basal. The embryo is absorbing and assimilating nutriment all the while at a relatively rapid rate. The calorific value of the oxidized solid, which is in truth the amount of energy lost during a certain chosen interval, in Tangl's judgment stands for the energy of embryogenesis; i.e., the energy of development (growth + differentiation). We believe that this conception is erroneous. The two processes, anabolism and catabolism, occur together and undoubtedly have some relationship, but surely one is not a measure of the other. In a starving animal, and so probably in a starving embryo, there is a considerable amount of so called basal metabolism. Thus if the "Embryogenetic Energy" were measured under these conditions a figure would be obtained for which there was no growth to correspond, or in other words there would be a value for something which did not exist. It will be seen in our later communications that the changes with age of metabolic rate and growth rate do not coincide. The amount of catabolism under certain circumstances does not accelerate growth or anabolism, but seems rather to be a limiting factor. It is as if when the absorbed energy were constant an increase of catabolism would make inroads upon the amount of energy which otherwise would remain for storage (growth). If, as Pembrey's (20) experiments would tend to show, there is an increase of metabolism in the oldest embryos when the outside temperature is lowered, one would find at the end of incubation in such cases that there was a greater amount of so called "Energy of Development" but smaller embryo. It seems that the potential energy amassed as growth comes from that remaining after the needs of the body have been satisfied. The results of the experiments described in this paper have formed the basis for judgment in the selection of suitable standard conditions for the incubation of hen's eggs. Standardization was necessary so that in future experiments the more important environmental factors might be kept uniform within a certain appropriate range and therefore not be held accountable for deviations observed in the embryos. Henceforth in this series of papers the term "standard incubation conditions" will signify that (1) the temperature was constantly at 38.8 +/- 0.4 degrees C., (2) the humidity at 67.5 +/- 2.5 per cent, (3) there was a continuous flow of warm air into the incubator to provide the necessary circulation, and (4) the eggs were rolled once a day within the constant temperature room. The incubator, a double-walled copper cabinet, stands in a constant temperature room, the fluctuations of which are +/- 1.0 degrees C. The space between the walls of the incubator is filled with water which serves as a buffer to outer variations. It might be repeated that all the eggs are from White Leghorn hens, are incubated 2 days after laying, and that they are kept cold during the interval necessary for transportation. With the figures from our chemical analyses and metabolic rate experiments, it was possible to calculate values for the concentration of total solids, fat, and nitrogen throughout the incubation period. These data were necessary as a general chemical background for further work. The results of the calculations are obviously rough. Because of the great variability of the eggs a satisfactory degree of accuracy could not have been attained without a very large number of analyses supplemented by complete statistical treatment. The necessity for such a comprehensive study was not evident, and it is our belief that the approximations reached in this paper are sufficiently close to serve our present purposes. The chief facts that have been ascertained in this investigation are (1) Loss of water by the egg during incubation is a function of the atmospheric humidity in its immediate environment. More rapid circulation of air lowers the humidity around the egg and thus increases evaporation. Other facts influencing evaporation are (a) atmospheric temperature, (b) thickness and surface area of the shell, and (c) conditions within the egg, the most important of which, it is suggested, is the amount of heat produced by the embryo. The latter factor, in turn, depends upon its size and age, and a significant change does not become apparent until the last 3 or 4 days of incubation, that is to say, when the embryo is of sufficient mass to exert a measurable force. (2) The surface area of the eggs in sq. cm. may be approximately represented by the formula S = K W(2/3), where K = 5.07 +/- 0.10, and W = the weight of the whole egg in gm. (3) There is a loss of weight by the shell during incubation. This is most noticeable near the end of the cycle, when the loss seems to parallel in general the weight of the embryo. (4) There is also a loss of solid matter during incubation. Chemical analyses indicate that about 98 per cent of the material oxidized is fat. This conclusion is corroborative of previous work by Hasselbalch, Hasselbalch and Bohr, and Tangl. (5) Carbon dioxide may be measured with relative accuracy. When it is assumed that it is derived from the oxidation of fat, satisfactory corroboration of the chemical analyses is obtained. These experiments have furnished the data from which the values have been calculated for total solids, fats, and protein in the whole egg throughout incubation. The figures may be used later for comparison with the concentration of these substances within the embryo. PMID- 19872228 TI - TEMPERATURE AND THE MECHANISM OF LOCOMOTION IN PARAMECIUM. AB - 1. Frequency polygons in which the number of observations at each temperature is reduced to a percentage basis while the time factor is represented on a logarithmic scale, indicate that the time required by Paramecium to swim a unit distance at different temperatures varies within definite limits which are constant above 15 degrees . Below 15 degrees the range of variability very possibly is not the same, though probably likewise constant. 2. Logarithmic velocities deduced from mean, maximal, minimal, and modal time classes, when plotted against reciprocals of the absolute temperature, fall respectively on straight lines. These lines are parallel and give micro values of 8,000 above 15 degrees and probably 16,000 below. 3. This implies that the mechanism of locomotion in Paramecium remains essentially unaltered by a rise in temperature from 15 degrees to 30 degrees , and probably remains in a similar sense constant from 6 degrees to 15 degrees . 4. The theoretical interpretation of this result is possible in terms of a catenary series 0 --> A --> E in which the passages 0 - > A and A --> E are controlled by two catalysts differing respectively in concentration in different individuals and perhaps at different times in the same individual, but depending for their effective concentration on reactions having temperature coefficients identical with those which at each temperature characterize the biological process under consideration. PMID- 19872229 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. III. WEIGHT AND GROWTH RATE AS FUNCTIONS OF AGE. AB - 1. The average weights of chicken embryos between 5 and 19 days of incubation as found by over 600 weighings may be expressed by a simple exponential equation, W = K t(3.6) where K = 0.668. 2. The velocity of growth (i.e. the percentage increase in mass) is inversely proportional to the incubation age. The product of the two (vt) is a constant (3.6). The negative acceleration of growth likewise decreases with age. PMID- 19872230 TI - TEMPERATURE CHARACTERISTIC FOR LOCOMOTOR ACTIVITY IN TENT CATERPILLARS. AB - The frequency of abdominal peristaltic locomotor waves in tent caterpillars during vertical ascension is controlled by the temperature according to the equation of Arrhenius. The constant micro (temperature characteristic) has the value 12,200 calories, agreeing quantitatively with the value obtained for a number of other (non-respiratory) rhythmic neuromuscular movements among arthropods. PMID- 19872231 TI - THE EFFECT OF X-RAYS ON THE IRRITABILITY OF MUSCLES IN THE FROG. AB - Exposure of the muscle preparation of the frog to the x-rays is accompanied by a better maintenance of muscular irritability than in the case of the non-exposed preparation. This is shown by its response to a smaller electrical stimulus than the control muscle. PMID- 19872232 TI - A COMPARISON OF BONE GROWTH IN LENGTH WITH BONE GROWTH IN WEIGHT. AB - 1. The growth capacity in length of the humerus and femur of male and female albino rats during the growth period from 23 to 150 days of age is less than the growth capacity in weight. This shows that the processes productive of bone strength are more active than those concerned in longitudinal expansion or stature. 2. Growth capacity in length is less affected than is growth capacity in weight by the systemic determinants and the factors incident to sex, weaning, and puberty. Since the findings as a whole are consistent with the assumption that bone growth in length is largely a matter of increase in cell number, while bone growth in weight is largely a matter of increase in cell size and density, the generalization is made that, in the bones at least, growth by increase in cell number is more stable than growth by increase in cell size and density. 3. A stabilization and approximation to a uniform level of growth capacity in both length and weight occurs at the culmination of puberty, which is quite like that taking place in the chemical differentiation at the same time. 4. Bone growth in length is more like body growth in length than bone growth in weight is like body growth in weight. PMID- 19872233 TI - ELECTROENDOSMOSIS THROUGH MAMMALIAN SEROUS MEMBRANES : II. COMPARISON OF HYDROGEN ION REVERSAL POINTS WITH ACETATE AND WITH CITRATE-PHOSPHATE BUFFERS. AB - The hydrogen ion reversal points of human, dog, and cat serous membranes have been determined with acetic acid-sodium acetate buffer mixtures, and are compared with the reversal points of the same membranes estimated with citrate-phosphate mixtures. The values with acetate buffer are about one-quarter of a pH unit higher (more alkaline) for fat membranes and almost one-half a pH unit higher for lean membranes. The acetate values are believed to correspond more closely to the true hydrogen ion reversal points. The reversal points are again found to be characteristic for membrane and species. No evidence of a postmortem shift in reversal point has been found. The charge of the membranes even in the living animal is capable of ready and repeated reversal. PMID- 19872234 TI - THE INFLUENCE OF THE INTENSITY OF LIGHT ON THE RATE OF GROWTH AND DURATION OF LIFE OF DROSOPHILA. AB - The duration of the larval and imago periods of Drosophila cultures which had been previously grown in the dark for 200 generations has been determined at various light intensities. 1. The duration of the larval period is shortened slightly at intensities around 2,500 meter candles, but becomes increasingly longer at higher intensities. The larvae are killed by continuous exposure to light of 7,000 to 10,000 meter candles. 2. The pupae are killed at intensities greater than 5,000 meter candles. 3. Above 1,000 meter candles the duration of the imago period is rapidly shortened. 4. The duration of life of the imago at different intensities of illumination can be quite accurately predicted by assuming that the light produces an independent "rate of aging" which is proportional to the intensity of the light. 5. The result of short exposure of the imago shows that light does not merely accelerate the normal "rate of aging," and also that the effect is only partially reversible. Diffuse daylight does not affect the upper temperature limit of growth. PMID- 19872235 TI - THE INACTIVATION OF TRYPSIN BY X-RAYS. AB - 1. The inactivating effect of soft x-rays on trypsin in solutions of various degrees of concentration has been studied. 2. It has been found to run parallel with spontaneous heat inactivation. It is almost, if not entirely, confined to the free or active trypsin. 3. Under radiation of constant intensity, the inactivation follows the simple exponential law which indicates a monomolecular reaction. 4. Estimates have been made of the amount of ionization required to inactivate trypsin to half value in these experiments and in those of Hussey and Thompson, who employed the beta rays from Radium B and C. The close agreement corroborates the idea that the effect is a function of ionization only. 5. The nature of the process of inactivation is discussed; inactivation seems to result from electrical neutralization of the trypsin ion. PMID- 19872236 TI - SOME CONSEQUENCES OF THE THEORY OF MEMBRANE EQUILIBRIA. AB - In applying Donnan's theory of membrane equilibria to systems where the non diffusible ion is furnished by a weak acid, base, or ampholyte, certain new relations have been derived. Equations have been deduced which give the ion ratio and the apparent osmotic pressure as functions of the concentration and ionization constant of the weak electrolyte, and of the hydrogen ion concentration in its solution. The conditions for maximum values of these two properties have been formulated. It is pointed out that the progressive addition of acid to a system containing a non-diffusible weak base should not cause the value of the membrane potential to rise, pass through a maximum, and fall, but should only cause it to diminish. It is shown that the theory predicts slight differences in the effect of salts on the ion ratio in such systems, the effect increasing with the valence of the cation. PMID- 19872237 TI - STUDIES ON SALT ACTION : X. THE INFLUENCE OF ELECTROLYTES UPON THE VIABILITY AND ELECTROPHORETIC MIGRATION OF BACTERIUM COLI. AB - 1. The strain of Bacterium coli used in these experiments multiplies in distilled water at pH 6.0 and pH 8.0 and in Ringer-Locke solution at pH 6.0. Under all the other conditions studied the numbers decrease with the passage of time. 2. The electrophoretic charge of the cells is highest in distilled water at pH 6.0 and pH 8.0. Under all other conditions studied the velocity of migration is decreased, but the decrease is immediate and is not affected by more prolonged exposure. 3. A strongly acid solution (pH 2.0) causes a rapid death of the cells and a sharp decrease in electrophoretic charge, sometimes leading to complete reversal. 4. A strongly alkaline solution (pH 11.0) is almost as toxic as a strongly acid one, although in distilled water the organisms survive fairly well at this reaction. Electrophoretic charge, on the other hand, is only slightly reduced in such an alkaline medium. 5. In distilled water, reactions near the neutral point are about equally favorable to both viability and electrophoretic charge, pH 8.0 showing slightly greater multiplication and a slightly higher charge than pH 11.0. In the presence of salts, however, pH 8.0 is much less favorable to viability and somewhat more favorable to electrophoretic charge than is pH 6.0. 6. Sodium chloride solutions, in the concentrations studied, all proved somewhat toxic and all tended to depress electrophoretic charge. Very marked toxicity was, however, exhibited only in a concentration of .725 M strength or over and at pH 8.0, while electrophoretic migration velocity was only slightly decreased at a concentration of .0145 M strength. 7. Calcium chloride was more toxic than NaCl, showing very marked effects in .145 M strength at pH 8.0 and in 1.45 M strength at pH 6.0. It greatly depressed electrophoretic charge even in .0145 M concentration. 8. Ringer-Locke solution proved markedly stimulating to the growth of the bacteria at pH 6.0 while at pH 8.0 it was somewhat toxic, though less so than the solutions of pure salts. It depressed migration velocity at all pH values, being more effective than NaCl in this respect, but less effective than CaCl(2). 9. It would appear from these experiments that a balanced salt solution (Ringer-Locke's) may be distinctly favorable to bacterial viability in water at an optimum reaction while distinctly unfavorable in a slightly more alkaline solution. 10. Finally, while there is a certain parallelism between the influence of electrolytes upon viability and upon electrophoretic charge, the parallelism is not a close one and the two effects seem on the whole to follow entirely different laws. PMID- 19872238 TI - THE ELECTRIC CAPACITY OF SUSPENSIONS WITH SPECIAL REFERENCE TO BLOOD. AB - 1. The specific capacity of a suspension is that capacity which) combined in parallel with a certain resistance, electrically balances 1 cm. cube of the suspension. 2. The following formula holds for the specific capacity of a suspension of spheroids, each of which is composed of a well conducting interior surrounded by a thin membrane of a comparatively high resistance: See PDF for Equation C, specific capacity of suspension; C(o), static capacity of one sq. cm. of membrane; r, r(1) specific resistances respectively of suspension and of suspending liquid; 2 q major axis of spheroid, alpha constant tabulated in Table I. 3. The following formula holds practically for any suspension whatever the form of the suspended particle. See PDF for Equation C = C(100) being the specific capacity of a suspension with a concentration of 100 per cent. Formulae (1a) and (1b) hold only for the case, when the frequency is so low, that the impedance of the static capacity of the membrane around a single particle is high as compared with the resistance of the interior of the particle. The formulae hold also for a suspension of homogeneous particles, when polarization takes place at the surface of each particle, provided the polarization resistance is low as compared with the impedance of the polarization capacity. 4. A description is given of a method for measuring the capacity of a suspension at frequencies between 800 and 4(1/2) million cycles. By means of a specially designed bridge, a substitution method is employed, by which in the last analysis the suspension is compared with the suspending liquid which is so diluted as to have the same specific resistance as the suspension, consecutive measurements being made in the same electrolytic cell. 5. Formula (1b) is verified by measurements of the capacity of suspensions of varying volume concentrations of the red corpuscles of a dog. 6. By means of the above measurements, the value of C(o) is calculated by equation (1a). 7. It is found that C(o) is independent of the frequency up to 4(1/2) million cycles and that it is also independent of the suspending liquid. These results furnish considerable evidence of the validity of the theory, that C(o) represents the static capacity of a corpuscle membrane. 8. On this assumption and using a probable value for the dielectric constant of the membrane, the thickness of the membrane is calculated to be 3.3.10(-7)cm. PMID- 19872239 TI - THE ELECTRIC RESISTANCE AND CAPACITY OF BLOOD FOR FREQUENCIES BETWEEN 800 AND 4(1/2) MILLION CYCLES. AB - 1. The variation of the experimental values (R (omega)), (C (omega)) of the resistance and capacity of blood for increasing frequencies is approximately represented by the equation: See PDF for Equation in which R(o) and C(o) are the resistance and capacity of the blood at low frequency and See PDF for Equation is the resistance of the blood at infinite frequency. Formulae (1) and (2) are derived by considering the blood as equivalent to the system shown in the diagram (a) of Fig. 1. 2. By the application of formula (1) to our experimental data the value of R(infinity) can be extrapolated with high accuracy. R(infinity) represents the resistance) which would have been obtained at low frequency, if the membranes around the corpuscles could have been removed. 3. The specific resistance of the corpuscle interior can be calculated by equation (5), using experimental values for R(infinity), for the volume concentration of the blood and for the specific resistance of the serum. 4. The specific resistance of the interior of the red corpuscle of the calf is found to be 3.5 +/- 10 per cent times the specific resistance of the serum. PMID- 19872240 TI - ON SOME GENERAL PROPERTIES OF PROTEINS. AB - 1. The processes of denaturation and coagulation of hemoglobin are like those of other proteins. 2. When hemoglobin is denatured it is probably depolymerized into hemochromogen. 3. When other proteins are denatured they, too, are probably depolymerized. Conversely, native proteins can be regarded as aggregates of denatured proteins. 4. The globins and histones are to be regarded as denatured proteins rather than as a distinct group of proteins. 5. The factors affecting the equilibrium between native and denatured proteins have been considered. 6. A non-polar group is uncovered when a protein is denatured. 7. It has been shown that judged by the two most sensitive tests for the specificity of proteins, it is only when proteins are in the native form that they are highly specific. PMID- 19872241 TI - A MICRO DISSECTION OF THE PACHYTENE THREADS OF TRADESCANTIA VIRGINICA L. WITH OBSERVATIONS ON SOME ASPECTS OF MITOSIS. AB - A micro dissection of the pachytene threads of Tradescantia virginica L. shows that the relation of the chromosomes is a matter of continuous linkage in a chain and that, undoubtedly, division and segregation are everywhere processes of abstriction with subsequent mechanical distribution of the elements. PMID- 19872242 TI - THE CARBON DIOXIDE EXCRETED IN ONE MINUTE BY ONE CENTIMETER OF NERVE-FIBER. AB - One centimeter of nerve-fiber from the lateral-line nerve of the dogfish is estimated to excrete on the average 4.2 x 10(-8) mg. CO(2) per minute. PMID- 19872243 TI - THE SHAPE OF THE MAMMALIAN ERYTHROCYTE AND ITS RESPIRATORY FUNCTION. PMID- 19872244 TI - THE EFFECT OF THE H ION CONCENTRATION ON THE AVAILABILITY OF IRON FOR CHLORELLA SP. AB - The data obtained in these experiments indicate clearly that unless the necessary precautions are taken to keep the iron of the culture medium in solution the results obtained by varying the H ion concentration will not represent the true effect of this factor on growth. The availability of iron in nutrient solutions has been the subject of numerous recent investigations and it is now known that iron is precipitated at the lower hydrogen ion concentrations, that the iron of certain iron salts is less likely to be precipitated than that of others, and that certain salts of organic acids tend to keep the iron in solution. In general, ferric citrate seems to be the most favorable source of iron. In addition to chemical precipitation, however, it is also possible for the iron to be removed by adsorption on an amorphous precipitate such as calcium phosphate. As this precipitate is frequently formed when nutrient solutions are made alkaline, this may account for the discordant results reported in the literature as to the availability of certain forms of iron. By omitting calcium from the culture solution iron can be maintained in a form available for growth in alkaline solutions by the addition of sodium citrate. In such solutions the maximum growth of Chlorella occurred at pH 7.5. The alkaline limit for growth has not been established as yet. In investigating the availability of iron at varying concentrations of the hydrogen ion, changes in the pH value of the solution during the course of an experiment should also be taken into account. This is especially important in unbuffered solutions. The differential absorption of the ions of ammonium salts may cause a marked increase in the hydrogen ion concentration, which in turn will cause an increase in the solubility of iron. In strongly buffered solutions as used in these experiments this effect is slight. PMID- 19872245 TI - THE EFFECT OF RADIOACTIVE RADIATIONS AND X-RAYS ON ENZYMES : IV. THE EFFECT OF RADIATIONS FROM RADIUM EMANATION ON SOLUTIONS OF INVERTASE. AB - The radiochemical inactivation of invertase by beta radiation from the radioactive products in equilibrium with radium emanation can be explained quantitatively on the same basis as that of trypsin and pepsin previously reported; namely, the rate of change in the logarithm of the concentration of the active enzyme with respect to the variable, W, is constant, under the conditions of irradiation described, when the volume of solution exposed is constant. When, within the limits stated in this paper, this volume (V) is varied, the rate of radiochemical change is inversely proportional to V; i.e., See PDF for Equation. PMID- 19872246 TI - THE EFFECT OF RADIATIONS FROM A MERCURY ARC IN QUARTZ ON ENZYMES : I. THE EFFECT OF ULTRA-VIOLET RADIATION ON PEPSIN IN SOLUTION. AB - Pepsin in solution is inactivated by the radiations from a mercury arc in quartz. It would seem that the effective radiations are those in the ultra-violet region of the spectrum. The form of the curve describing the course of the inactivation is the same as that found for monomolecular chemical change. PMID- 19872247 TI - X-RAY DIFFRACTION PATTERNS FROM PLANT FIBERS. AB - The rather long discussion just given seemed necessary in order to establish certain points before attempting to develop the lattice structure and before working out the identity of the structural unit of the ramie fiber. 1. Certain planes, 6.10, 5.40, 3.98, etc., as given in Table I, run lengthwise of the fiber; that is, they are parallel to the long axis. 2. These planes are in agreement with the assumption that one set, either the 6.10 or the 5.40 is tangential to the fiber and forms concentric cylinders, with the long axis of the fiber as the long axis of the cylinders; the other set, either the 5.40 or the 6.10. cuts the former at right angles and therefore its planes are radial with respect to the fiber, theoretically all of them meeting at the long axis, as indicated in the cross-section of a fiber in Fig. 3. 3. Other planes, 5.15, 3.40, 2.58, etc., as given in Table III, are transverse planes which form right angles with the long axis and therefore with the planes of Table I. 4. All of the planes are composed of reflecting units, probably groups of atoms, located at the intersections of the planes. This being the case, other reflecting planes must occur at other angles to the long axis. This prediction is verified by the lines given in Table IV. 5. The structural units in the wall of the fiber thus form a space lattice, the elementary cell of which is an orthorhombic structure. 6. Comparatively little can be said as yet concerning the structural unit. The unit is very probably composed of a group of atoms which are more or less closely packed together. If the groups were visible they would appear, in a cross-section of a fiber, as closely packed groups of atoms, 6.10 A.u. from center to center of groups in one direction, and 5.40 A.u. at right angles to that. In a longitudinal section, however, they would appear less compact and might even lose the appearance of groups in forming long strings of atoms which would extend lengthwise of the fiber. By establishing the positions of the planes in the wall of the fiber, as in Tables I, III, and IV, it would seem that all dimensions of the elementary cell, and the size and character of the structural unit, could be determined. Work along these lines is now in progress. PMID- 19872248 TI - ACCUMULATION OF BRILLIANT CRESYL BLUE IN THE SAP OF LIVING CELLS OF NITELLA IN THE PRESENCE OF NH(3). AB - When the living cells of Nitella are placed in a solution of brilliant cresyl blue containing NH(4)Cl, the rate of accumulation of the dye in the sap is found to be lower than when the cells are placed in a solution of dye containing no NH(4)Cl and this may occur without any increase in the pH value of the cell sap. This decrease is found to be primarily due to the presence of NH(3) in the sap and seems not to exist where NH(3) is present only in the external solution at the concentration used. PMID- 19872249 TI - THE PENETRATION OF CO(2) INTO LIVING PROTOPLASM. AB - The experiments indicate that little or no CO(2) enters normal cells of Valonia except in the form of undissociated molecules. Whenever the interior of a cell is more acid than the surrounding medium (excess base being the same in both) we may expect that at equilibrium the internal concentration of total CO(2) will be less than the external. PMID- 19872250 TI - TEMPERATURE AND HEART RATE IN PTEROTRACHEA AND TIEDEMANNIA. AB - 1. For the heart rate in Pterotrachea coronata, intermediate temperatures disclose a thermal increment of 11,200 +/-. This value is identical with the one reported by Crozier and Stier for the lamelli-branch, Anodonta. In the pteropod, Tiedemannia neapolitana the same temperatures typically reveal in the heart rate a micro value of 16,200 +/- This agrees quantitatively with 16,300 found by Crozier and Stier for the heart of the slug, Limax maximus. 2. At high temperatures the average value of micro for Pterotrachea is 7,300: for Tiedemannia, 7,400. The corresponding averages at the lower limits are 22,000 and 23,000. 3. The great variability found near the edges of the temperature field are explicable in two ways. During intermissions characteristic of high temperatures and occurring also at low, we can assume a restorative process; while at both the upper and lower limits we may, in addition, find that reactions assume control which under ordinary circumstances never do so. Special evidence indicates that the highest temperatures employed, 27 degrees C., and the lowest, 4 degrees C., caused no irreversible changes in mechanism. 4. The theoretical analysis of the experimental facts makes use of Meyerhof's conception of carbohydrate metabolism and projects the cyclical nature of rhythm into the substrate of control. Assuming as a source of energy an original supply of material O, the value of 22,000 +/- is assigned provisionally to a mobilization hydrolysis while 11,200 +/- and 16,000 +/- are attached to oxidative reactions influenced respectively by OH' and possibly Fe, or some other catalyst. The lowest value, 7,300 +/- is assumed to indicate a synthetic process (lactic acid - > glycogen?), possibly limited by CO(2) excretion. In the present state of our knowledge, this distribution and interpretation seems to account reasonably for the experimental facts, but until we know more about the neurogenic controls, is entitled to rank only as an hypothesis. PMID- 19872251 TI - TIME RELATIONS OF GROWTH : II. THE EQUIVALENCE OF AGE IN MAMMALS ESTIMATED ON THE BASIS OF THEIR GROWTH CONSTANTS. AB - The numerical values of the growth constants given in the preceding paper of this series are utilized for determining equivalence of growth age and growth weight in several animal forms. The results are presented in the form of two age equivalence tables and fifteen age-equivalence and weight-equivalence charts. PMID- 19872252 TI - THE EFFECT OF RADIOACTIVE RADIATIONS AND X-RAYS ON ENZYMES : V. THE INFLUENCE OF VARIATION OF THE THICKNESS OF THE ABSORBING LAYER OF SOLUTIONS OF PEPSIN UPON THE RATE OF RADIOCHEMICAL INACTIVATION OF THE ENZYME. AB - EVIDENCE IS PRESENTED WHICH INDICATES: (1) that the effect of gamma radiation is negligible with respect to that of beta radiation upon pepsin in dilute solution under the conditions employed in the experiments made; (2) approximately the thickness of fluid layer which may be regarded as necessary and sufficient to practically completely absorb the available beta radiation; (3) that the mean reaction speed coefficient in radiochemical inactivation of pepsin varies inversely with the volume of solution irradiated if the thickness of the fluid layer satisfies the sufficient condition stated in (2), and beyond this as far as has been studied. PMID- 19872253 TI - THE EFFECT OF RADIOACTIVE RADIATIONS AND X-RAYS ON ENZYMES : VI. THE INFLUENCE OF VARIATION OF TEMPERATURE UPON THE RATE OF RADIOCHEMICAL INACTIVATION OF SOLUTIONS OF PEPSIN BY BETA RADIATION. AB - Data are presented which indicate that variation in temperature is associated with only slight variation in the speed of the radiochemical inactivation of pepsin in dilute solution. PMID- 19872254 TI - CARBON DIOXIDE PRODUCTION AND DURATION OF LIFE OF DROSOPHILA CULTURES. AB - The total CO(2) produced by aseptic Drosophila cultures during the entire duration of life has been determined at 15 degrees , 26 degrees , and 30 degrees C. in the dark and at 22-26 degrees C. in the light. The total amount of CO(2) produced is not constant but is greater at 15 degrees than at 26 degrees or 30 degrees , and is much greater in the light than in the dark. The total duration of life, therefore, is not determined by the time required to produce a limiting amount of CO(2). PMID- 19872255 TI - THE EFFECT OF ADVANCE IN LACTATION AND GESTATION ON MAMMARY ACTIVITY. AB - The rate of milk secretion in farrow cows may be expressed as See PDF for Equation, in which y = yield and t = time from calving. Pregnancy causes a decrease in yield which may be expressed as See PDF for Equation, in which i = inhibition or decrease in yield and p = time from conception. The constant K appears to be the same for various groups but b is roughly proportional to a. The decrease in yield associated with pregnancy is interpreted as due to a hormone. The hormone hypothesis also affords an interpretation of the increasing rate of milk secretion which occurs for a short time following parturition. PMID- 19872256 TI - THE DISSOCIATION CONSTANTS OF RACEMIC PROLINE AND CERTAIN RELATED COMPOUNDS. AB - 1. It has been experimentally shown that breaking of the pyrrolidine ring of proline by nitrous acid is not a factor of sufficient magnitude to account for the amino nitrogen which is usually found in proline preparations. 2. A method for the preparation of racemic proline is described. The product was found to be free from amino nitrogen. 3. The dissociation constants of racemic proline and of certain structurally related compounds were determined. PMID- 19872258 TI - THE ISOELECTRIC ZONE OF TYPHOID AGGLUTININ. AB - The isoelectric point of typhoid agglutinin lies between pH 4.4 and pH 4.6. PMID- 19872257 TI - A CONCENTRATION GRADIENT IN CORN STALKS. PMID- 19872259 TI - THE COMBINATION OF SALTS AND PROTEINS : II. A METHOD FOR THE DETERMINATION OF THE CONCENTRATION OF COMBINED IONS FROM MEMBRANE POTENTIAL MEASUREMENTS. AB - A method is described for measuring membrane potentials of gelatin-salt solutions, and it is pointed out that such measurements, together with the analysis of the solutions, allow the calculation of the concentration of ions combined with the protein. The values for the combined ions obtained in this way for ZnCl(2), KCl, LiCl, and HCl agree quite well with those obtained by direct concentration cell measurements. PMID- 19872260 TI - ELECTROENDOSMOSIS THROUGH MAMMALIAN SEROUS MEMBRANES : III. THE RELATION OF CURRENT STRENGTH AND SPECIFIC RESISTANCE TO RATE OF LIQUID TRANSPORT. TRANSPORT RATE WITH SERUM. AB - The rate of electroendosmotic flow through dog and cat pericardia is found to be proportional to the current strength. The plots of current strengths against volumes of liquid transported in unit time are, in the better experiments, straight lines passing through the origin; the slopes of the lines are characteristic of the several systems. Data on transport rate with buffers of different specific resistances showed the following phenomena: 1. Decrease of the observed transport rate to a minimum between sigma values of 95 and 60 ohms. 2. Changes in the membrane markedly affecting transport rate, at conductivities and osmotic pressures close to those of the blood. 3. Polarization of the membrane during the passage of current. The mean rate found for electroendosmotic transport across dog and cat serous membranes bathed in serum has been 0.19 to 0.30 (average, 0.25) c.mm. per minute per milliampere. The best experiments with dog serum and the living mesenteries of dogs under ether gave a mean rate of 0.29 c.mm. per minute per milliampere. These data, together with data from other sources, are believed to indicate a probability approaching certainty that electroendosmotic effects are a factor in glandular secretion. PMID- 19872261 TI - GALVANIC STIMULATION OF LUMINESCENCE IN PELAGIA NOCTILUCA. AB - 1. Pelagia noctiluca responds to galvanic stimulation by a luminescent glow at the anode. If placed near the cathode a secondary glow occurs also on the cathodal side. 2. The luminescent slime of Pelagia when subjected to the galvanic current glows around the cathode. This is referred partly to the movement of hydrogen bubbles, but in the main to the alkali formed at the cathode. 3. The cause of galvanic stimulation in Pelagia is ionic. (1) Anodal stimulation is referred to the blocking of positive ions by the tissue on that side. (2) Cathodal stimulation, when the animal lies near the cathode, is due to the diffusion of alkali outward from a region of high concentration (the cathode). 4. Only the margin of the bell is excited to luminescence by the galvanic current. It is therefore concluded that nervous elements are the seat of excitation. 5. Luminescence is not a result of muscular contraction, since K ion causes relaxation of musculature but a continuous luminescent glow in Pelagia. The galvanic current causes pulsations of the bell (contraction and relaxation of the musculature) but a continuous glow. PMID- 19872262 TI - EVIDENCE OF A FACTOR ASSOCIATED WITH ACTIVELY FUNCTIONING TISSUES WHICH GIVES TO SUGARCANE PLANTS RESISTANCE TO THE INVASION OF FUNGI AND OTHER MICROORGANISMS. PMID- 19872263 TI - THE TRANSPORT OF GAS BY THE BLOOD OF THE TURTLE. AB - The chief characteristics of the blood of the turtle Pseudemys concinna, considered as a system for the transport of oxygen and carbon dioxide, are its low corpuscular content (10 to 22 per cent by volume) and its high concentration of base bound as bicarbonate. These characteristics account fully for the shape and position of the carbon dioxide dissociation curve, the effect of oxygenation and reduction of the hemoglobin upon the carbon dioxide-combining power of the blood, and the distribution of carbon dioxide between the corpuscles and plasma. The oxygen-combining capacity of the turtle corpuscles does not differ from that of an equal volume of human erythrocytes. The oxygen dissociation curve is similar to that of mammalian blood and is affected in like manner by the quantity of carbon dioxide present. Its exact shape and position depend in part upon the number of corpuscles in the blood; in part its characteristics cannot be attributed to known chemical factors. PMID- 19872264 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. VII. THE CONCENTRATION OF THE ORGANIC CONSTITUENTS AND THE CALORIFIC VALUE AS FUNCTIONS OF AGE. AB - 1. The water, ash, glycogen, nitrogen, and ether extract content of the tissues of chicken embryos were determined between the 5th and the 19th days of incubation. 2. It was found that the concentration of solid substance changed from approximately 5 to 17 per cent during this interval. The chief change in the organic substances involved a relative decrease in the nitrogen as compared with the fat. 3. Bomb calorimetric estimations confirmed these findings. It was shown that the calorific value of the dried substance increased with age. 4. The rate of growth of the total solids, and of the potential energy of the tissues was estimated. 5 Various theoretical considerations were brought forward dealing chiefly with the order in which the chief organic substances, carbohydrate, protein, and fat could be ranged when judged by various criteria. PMID- 19872265 TI - SPEED OF TOXIC ACTION OF ARSENIC IN THE SILKWORM. AB - A micro burette, micro pipette, and methods for their use in quantitative toxicological investigations on mandibulate insects are described. It is suggested that the form of curves relating speed of toxic action to dosage may be explained by postulating suitable changes in rate of distribution, excretion, and cell penetration of poison as dosage varies. The speed of toxic action of pentavalent arsenic in the silkworm is proportional to an integral power of the dosage at lower concentrations, and to a fractional power of the dosage at higher concentrations. PMID- 19872266 TI - LIGHT TITRATIONS : I. THE STARCH-IODINE REACTION. AB - 1. The usefulness of the radiomicrometer in titration work has been pointed out. The authors suggest that light titration may also be used where a reaction mixture changes its absorption in the (near) infra-red. 2. The applicability of this method to the starch-iodine reaction has been demonstrated. PMID- 19872267 TI - THE SALT ERROR OF INDICATORS CAUSED BY STANDARD ALKALINE BUFFERS THEMSELVES. AB - 1. It is found that with many indicators there is a big discrepancy between the true alkalinities or pH values of solutions of pure sodium hydroxide and of standard alkaline buffers which give the same actual colour. This discrepancy must be ascribed to salt error caused by the buffer itself and exceeds in the most extreme case two whole units of pH; that is, an error of 100 fold in determining alkalinity. In only three cases, namely alizarin yellow G, tropeolin O, and thymol violet, was this error inappreciable. Most of the thirty indicators tested were found for various reasons unsatisfactory in the alkaline range studied. 2. Several indicators show a maximum depth of colour after sufficient indicator has been added, but above a certain concentration further addition of indicator diminishes the colour again. PMID- 19872268 TI - TEMPERATURE CHARACTERISTICS FOR PREPUPAL DEVELOPMENT IN DROSOPHILA MELANOGASTER. AB - 1. Diurnal fluctuations in emergence of the adults and negative correlation between the length of successive stages in the puparium made it desirable to restrict study of relation of temperature to development to the prepupal stage. 2. On morphological grounds, the formation of the puparium, which starts the prepupal period, seemed to be determined by the stage of larval development; pupation, which terminates the prepupal stage, by imaginal disk development. 3. The rate of prepupal development may be represented by the Arrhenius equation relating velocity of an irreversible chemical reaction with temperature. The data gave three values for the critical increment over different temperature intervals, corresponding to three straight lines of different slope. When deviations of the points from these lines were compared with their probable errors, however, in nearly three-fourths of the cases the difference was significant. 4. Analysis of these deviations showed them to be due primarily to changes in the extent of imaginal disk development at the time of puparium formation. These, in turn, were correlated with age of the culture. 5. The two sexes differed in developmental velocity, such that the rate of female development was about 1.03 times as great as rate of male development. For the upper temperatures this ratio was greater than for the lowest of the three temperature ranges, the intermediate zone possibly varying between the two. 6. A final curve relating prepupal development to temperature has been calculated after (1) converting all female records to a male basis, (2) applying a correction for age of culture error, and (3) weighting each point by the square root of the number of cases upon which it was based. This yielded the following values for the temperature characteristic micro, namely, 33,210 from 12-16 degrees , 16,850 from 16-25 degrees , and 7,100 from 25-30 degrees . Above 30 degrees the data could not be fitted by the Arrhenius equation. 7. By treating prepupae in different developmental stages to brief exposures at a lower temperature, pupation was more delayed by treatment at the beginning than at the end of the prepupal stage. From these data, micro for parts of the stage were calculated on the assumption that the effect of temperature did not persist after return to the standard temperature. Since the micro thus secured were greatest for the beginning and least for the end, and none were less than that for the whole, the interrelations of the successive stages are probably more complex than they were assumed to be in making the calculations. 8. Lowering the temperature prior to puparium formation lengthened the prepupal stage. Puparium formation, therefore, was not conditioned by imaginal disk development, but by larval processes possessing a lower temperature coefficient than did the imaginal disks. 9. Possible physicochemical mechanisms for producing these results are discussed, and the observed temperature characteristics were finally attributed to three relatively independent anabolic processes which limit the rate of cell growth in the imaginal disks. 10. Both the thermal increments and the critical temperatures for the prepupal stage differed markedly from those reported by Loeb and Northrop for the entire development within the puparium. Since the prepupa forms part of the latter period, temperature characteristics for extended developmental phases known to be heterogeneous are of doubtful significance. PMID- 19872269 TI - THE RESISTANCE OF LIVING ORGANISMS TO DIGESTION BY PEPSIN OR TRYPSIN. AB - 1. Pepsin and trypsin are quickly removed from solution by dead organisms. They are not able to penetrate into living organisms. 2. Trypsin injected into a living Amoeba results in the death and disintegration of the cell. PMID- 19872270 TI - TEMPERATURE AND LOCOMOTION IN PLANARIA. AB - A consideration of the temperature characteristics or thermal increments for locomotion in Planaria shows that they agree essentially with those reported for certain activities of other animals (Crozier, and Glaser). A process with the lowest increment (micro = 7,000 to 8,000) assumes control of the locomotor rate at temperatures above 20-22 degrees ; that with the highest increment (micro = 18,000 to 22,000) controls below 13 degrees ; and one with an intermediate value (micro = 11,100) is in command at the intermediate temperatures (13-21 degrees ). Another reaction with increment micro = 14,600 may, under certain conditions (e.g. 2 weeks after feeding), control the series over the median range. Excepting the latter, these increments are typical of catalyzed oxidative reactions (Crozier 1924-25, b) so that when these are in control it may be assumed that respiration is the fundamental process determining the rate of locomotion. Feeding produces a modification of the increment throughout the median range of temperatures, up to 2 days afterward. PMID- 19872271 TI - A SYNTHETIC FOOD MEDIUM FOR THE CULTIVATION OF DROSOPHILA : PRELIMINARY NOTE. AB - In this paper is described the composition and method of making a standard synthetic medium for the laboratory cultivation of Drosophila melanogaster. It is shown that this medium is greatly superior to the banana medium commonly used for this purpose in respect of both the fertility and the mortality of flies kept on it. The range of superiority in respect of fertility is at different densities of population from about 48 per cent at the lowest, to 98 per cent at the highest densities experimentally reported here. The general experience of the laboratory with this medium, which frees experimental work on Drosophila from the incubus of the highly variable banana, shows it to have other points of superiority besides those discussed here. PMID- 19872272 TI - REVERSAL OF PHOTOTROPISM IN DIEMYCTYLUS VIRIDESCENS. AB - In its response to light of approximately 11.3 m.c. intensity Diemyctylus viridescens may be either positive or negative. Negative phototropism is characteristic of animals from which food has been withheld. Feeding suppresses this negative phototropism. PMID- 19872273 TI - NOTE ON THE DISTRIBUTION OF CRITICAL TEMPERATURES FOR BIOLOGICAL PROCESSES. AB - The critical temperatures at which irregularities appear in the relations between vital processes and temperature are not distributed at random. As based upon detailed knowledge of individual cases, and as derived from inspection of the frequencies of occurrence, these critical points are usually found to be in the neighborhood of 4.5 degrees , 9 degrees , 15 degrees , 20 degrees , 25 degrees , 27 degrees , 30 degrees . PMID- 19872274 TI - THE DISTRIBUTION OF TEMPERATURE CHARACTERISTICS FOR BIOLOGICAL PROCESSES; CRITICAL INCREMENTS FOR HEART RATES. AB - Disregarding sources of variation known to be present in the unselected data, it is shown that the frequency distribution of temperature characteristics (critical increments) calculated from all known series of observations, pertaining to a great variety of vital processes, exhibits a number of discrete modes. This leads to the view, already derived from evidence of a more specific sort, that such critical increments may be used to characterize definite processes in a controlling system of reactions which seems to be of widespread occurrence in living matter. PMID- 19872275 TI - ON THE MODIFICATION OF TEMPERATURE CHARACTERISTICS. AB - In December and January the frequency of heart beat in Limax exhibits micro = 11,500 +/- 250. The ingestion of a small volume of sugar solution results in temporary change of micro to 16,200 +/- 320, which accords quantitatively with the value obtained from these slugs in spring. This effect of the sugar is reversible, but lasts longer than the abolition of negative phototropism which the sugar also produces. Other instances are given in which the value of the temperature characteristics for vital processes have been changed experimentally. The new values which appear have already been obtained in connection with homologous activities. These results confirm the view that the critical thermal increments serve to characterize recognizably different governing reactions in living matter, and indicate a basis for specific experimental control. PMID- 19872276 TI - MECHANISM OF THE ACCUMULATION OF DYE IN NITELLA ON THE BASIS OF THE ENTRANCE OF THE DYE AS UNDISSOCIATED MOLECULES. AB - The rate of penetration of brilliant cresyl blue into the living cells of Nitella indicates that the dye enters only in the form of the undissociated molecule. At equilibrium the total concentration of the dye in the sap is proportional to the concentration of the free base in the outside solution. PMID- 19872277 TI - THE EFFECTS OF CERTAIN HEAVY METALS ON RESPIRATION. AB - 1. The effect of the heavy metals on the respiration of Aspergillus niger is to cause the rate of carbon dioxide production to decrease from the first or to increase and subsequently diminish. 2. The speed of the toxic action varies as a constant power of the concentration. 3. The temperature coefficient of the toxic action is between 1.5 and 2. 4. An hypothesis is advanced to account for the action of the heavy metals, by means of which the experimental results may be accounted for. It is assumed that the metal is activated by a chemical combination with a cell constituent. This active compound alters the velocity constants of the normal respiratory reactions, and thus causes the observed changes in the rate of carbon dioxide production. PMID- 19872278 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. VIII. ACCELERATIONS OF INTEGRATION AND DIFFERENTIATION DURING THE EMBRYONIC PERIOD. AB - The chief results of the studies here reported have been (1) the correlation between growth as a whole and the differentiation of gross form (primary redistributions or simple evolution), and (2) the correlation between internal integration or concentration and the differentiation of chemical form (secondary redistributions or compound evolution). With the latter are also associated the catabolic rate and the latent period or reaction time after implantation in plasma as demonstrated in tissue culture experiments. Moreover, it has been shown that these two chief developmental processes occur at different rates, and that they undergo their greatest changes in rate at different periods of embryonic life. Corresponding with Robertson's growth acceleration periods there may be three cycles or rhythms of which the embryonic phase is the first, each composed of a period of growth followed by a period of differentiation. This conception is somewhat analogous to Roux's notion of dividing the life span into two chief periods (1) embryonic for the growth of organ rudiments and (2) post-embryonic, characterized by functional development. The first period of total growth and form differentiation seems to cover the time when the main, but bare, outline or scaffolding of the organism is laid down. The second period, correlated as it is with catabolism (function), corresponds, not in time but as a phenomenon, with Roux's period of functional form development. PMID- 19872279 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. IX. THE IODINE REACTION FOR THE QUANTITATIVE DETERMINATION OF GLUTATHIONE IN THE TISSUES AS A FUNCTION OF AGE. AB - The iodine reaction to determine-SH groups in tissues according to the technique of Tunnicliffe showed that the percentage concentration of such compounds in the dried substance of chicken embryos declines with age chiefly during the third quarter of the incubation period. PMID- 19872280 TI - THE SHAPE OF THE MAMMALIAN ERYTHROCYTE AND ITS RESPIRATORY FUNCTION. II. PMID- 19872281 TI - A LATENT PERIOD IN THE ACTION OF COPPER ON RESPIRATION. AB - 1. When copper chloride is allowed to act on Aspergillus niger there is at first a period during which there is no change in the rate of the production of carbon dioxide, following which the rate of respiration falls. The interval of no change is called the latent period. 2. When the copper is removed from the external solution before the end of the latent period this interval is prolonged. The rate of respiration then falls to a new level below the normal level. 3. Experiments on Nitella and on Valonia indicate that the copper penetrates the cell almost immediately. 4. The length of the latent period varies inversely as a constant power of the concentration of the copper. 5. These results are explained by assuming that the copper is made active in the respiration system by means of a reversible reaction. By using appropriate velocity constants the experimental curves can be duplicated by calculated curves. PMID- 19872282 TI - STUDIES ON ENZYME ACTION : XXXV. LIPASE ACTIONS OF EXTRACTS OF TISSUES OF RABBITS AT DIFFERENT AGES. AB - The ester-hydrolyzing actions of extracts of a number of tissues of rabbits of different ages were studied under comparable conditions. The ages of the rabbits ranged from 8 days before birth to 2162 days. The esters used included phenyl acetate, glyceryl triacetate, methyl butyrate, benzyl acetate, methyl acetate, ethyl acetate, ethyl butyrate, methyl benzoate, ethyl benzoate, and isobutyl acetate. The following tissues were studied: kidney, liver, lung, skin, leg muscle, heart muscle, brain, spleen, stomach, and small intestine. The results, as in previous communications, are presented in the form of plots for the relative enzyme actions, and in tables for the absolute actions. The changes in the curves of the relative actions as the rabbits became older are considered in some detail. The relations between the embryonic state of certain tissues, as shown by their enzyme actions, and the adult state, are described, and compared with their physiological behavior. The probable reversion to a type approaching the embryonic for the oldest rabbits studied is indicated with some of the tissues. The changes in the absolute enzyme actions of the tissues as the rabbits became older are also discussed. The absolute actions do not form as regular a progression as do the relative actions but, at the same time, show marked regularities with increasing age of the rabbits. PMID- 19872283 TI - MOLECULAR STRUCTURE OF PLANT FIBERS DETERMINED BY X-RAYS. AB - It has been shown that the wall of the plant fiber is probably built up of unit groups of atoms which have assumed the form of a space lattice. The elementary cell of the lattice is an orthorhombic structure with the dimensions 6.10 x 5.40 x 10.30 A.u., and contains two unit groups equal in size to two C(6)H(10)O(5) groups. The crystallographic unit cell would contain 4 of these elementary cells and would be represented by Fig. 9 rather than by Fig. 3. The groups of atoms, C(6)H(10)O(5), are arranged in parallel chains running lengthwise of the fiber. In each chain the odd numbered groups have a different orientation from the even numbered. The chains, parallel to one another are spaced 6.10 A.u. in one direction and 5.40 A.u. at right angles to that. In these two directions the odd numbered chains also would have a different orientation from the even numbered. On account of the cylindrical shape of the fiber, the elementary cells are arranged in the form of concentric cylinders or layers. The dimensions of the fibers are such that the fiber wall is about 40,000 elementary cells in thickness, or in other words, the fiber is composed of that many concentric layers. If it could be magnified sufficiently, a cross-section of a fiber would show the end view of each cylinder as a dotted circle. The dots, representing the unit groups of atoms, would have considerable uniformity of spacing in both the tangential and the radial directions, 6.10 A.u. in one and 5.40 A.u. in the other. The structure could not be as rigidly exact as might be inferred, since the wall is deposited more or less rhythmically during a period of several days or weeks* in which adjustments in the arrangement of the unit groups undoubtedly occur. It is common knowledge that the fibers, under the microscope, rarely appear as true circles on cross-section; usually they appear as irregular, many sided polygons and the wall thickness is normally uneven. For our purpose it is simpler to think of the fiber as composed of concentric cylinders with diameters so large in proportion to the size of the unit groups that in relatively large segments they closely approach the parallelism of the planes of a rectangular lattice, sufficiently close to be capable of producing diffraction patterns. Although these conclusions seem to be in agreement with the diffraction patterns obtained from various positions of a bundle of approximately parallel fibers, the fact must not be overlooked that the structure cannot be proved with as great certainty as can the structure of a well formed crystal. The very nature of the fiber, its cylindrical shape, and the many internal adjustments which must take place, militate against a clean-cut demonstration. Models, made more or less to scale, were used in working out this structure. The unit group was constructed according to Irvine's suggestion that all the groups are glucose residues. An intensive study is now under way in which an attempt is being made to bring the models into agreement with the chemical and physical properties of the cellulose fibers and with the diffraction patterns. A report on that part of the work will soon be submitted for publication. PMID- 19872284 TI - THE KINETICS OF OSMOTIC SWELLING IN LIVING CELLS. AB - The rate of swelling of unfertilized sea urchin eggs in hypotonic sea water was investigated. Analysis of curves leads to the following conclusions. 1. The rate of swelling follows the equation, See PDF for Equation where V(eq)., V(0), and V(t) stand for volume at equilibrium, at first instant, and at time t, respectively, the other symbols having their usual significance. This equation is found to hold over a wide range of temperatures and osmotic pressures. This relation is the one expected in a diffusion process. 2. The rate of swelling is found to have a high temperature coefficient (Q(10) = 2 to 3, or micro = 13,000 to 19,000). This deviation from the usual effect of temperature on diffusion processes is thought to be associated with changes in cell permeability to water. The possible influence of changes in viscosity is discussed. 3. The lower the osmotic pressure of the solution, the longer it takes for swelling of the cell. Thus at 15 degrees in 80 per cent sea water, the velocity constant has a value of 0.072, in 20 per cent sea water, of 0.006. PMID- 19872285 TI - THE EFFECT OF HYDROGEN ION CONCENTRATION ON SWELLING OF CELLS. AB - 1. The effect of HCl, NaOH, CO(2), and NH(3) on the volume of unfertilized Arbacia eggs was tested over a wide range of pH values. 2. No swelling occurred, except in HCl solutions, and there not until after injury or death had occurred. 3. Whereas the volume of erythrocytes and of proteins such as gelatin is known to be dependent on the pH of the solution, such a relation does not exist in the case of living and uninjured cells, at least of the type tested. PMID- 19872286 TI - AN EMPIRICAL FORMULA FOR THE RELATION BETWEEN VISCOSITY OF SOLUTION AND VOLUME OF SOLUTE. AB - It has been found that the expression See PDF for Equation represents very closely the relation between the volume of the solute and the viscosity of the solution. The formula has been applied to a number of experimental results and found to hold very well for as high concentrations as 50 per cent solutions of such substances as sugars, glycogen, casein, and rubber. In the case of various sugar solutions, and also in the case of sulfur suspensions, the volume of the solute as calculated from the viscosity values agrees with the actual volume of the substance in dry state, as determined from specific gravity measurement, while in the case of caoutchouc solutions in benzene the values of varphi as calculated from the viscosity measurements fit remarkably well in the equation for osmotic pressure. PMID- 19872287 TI - RELATIVE SUSCEPTIBILITY TO ARSENIC IN SUCCESSIVE INSTARS OF THE SILKWORM. AB - The susceptibility of the silkworm to arsenic decreases during its larval development. Relative susceptibility may be expressed numerically as a ratio of areas under dosage-effect curves. PMID- 19872288 TI - THE TOXIC ACTION OF COPPER ON NITELLA. AB - 1. Using the loss of turgidity of the cells as a criterion it is found that the toxicity curve of copper chloride with Nitella is sigmoid. An empirical equation can be constructed which will approximately fit the curve. 2. When the concentration of the copper chloride is varied the toxic effect varies as a constant, fractional, power of the concentration. This relation holds when the concentration is plotted against either (1) the time necessary to reach a given point on the ordinate of the survivor curve, (2) the maximum speed of toxic action as shown by the tangent to the survivor curve or (3) the first derivative of the equation which fits the survivor curve. 3. When the temperature is varied and the logarithm of the reciprocal of the time necessary to reach a given point on the survivor curves is plotted against the reciprocal of the absolute temperature the resulting figure consists of several intersecting curves. A hypothetical system is described which will give straight lines under normal conditions and curves when acted upon by a toxic agent. PMID- 19872289 TI - THE SIZE OF PORES IN COLLODION MEMBRANES. AB - By the application of Poiseuille's law to the rate of flow of water through collodion membranes, it is calculated that the membranes used had pore radii of the order of 0.3 to 2 x 10(-6) cm. On the same basis the number of pores per sq. cm. appears to vary from 270 x 10(10) to 7 x 10(10), decreasing with increase in pore size. Reasons are given for preferring these figures for the radii to figures, 100 times as large, which were calculated by others. Microscopic examination of the membranes, with dark-field illumination, indicates that they are made up of solid granules or filaments of collodion much less than 1 x 10(-4) cm. in thickness. PMID- 19872290 TI - DURATION OF LIFE OF AN ASEPTIC DROSOPHILA CULTURE INBRED IN THE DARK FOR 230 GENERATIONS. AB - The number of pupae formed per female, the duration of the larval period, and the duration of the pupal-imago period of a normal Drosophila culture and of the 230th generation of an aseptic culture which had been kept in the dark have been determined. The larval period and the pupal-imago period were found to be nearly the same for both cultures under both favorable and unfavorable conditions. There is no evidence, therefore, to show that inbreeding, absence of light, or growth in the absence of bacteria for 230 generations has had any effect either on the duration of life or on the ability of the organism to resist unfavorable bacteria. PMID- 19872291 TI - A CONVENIENT METHOD FOR THE FORMOL TITRATION. PMID- 19872292 TI - A DISCUSSION OF RECENT STUDIES ON THE METABOLISM OF NORMAL AND MALIGNANT CELLS. PMID- 19872293 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. X. THE TEMPERATURE CHARACTERISTIC FOR THE CONTRACTION RATE OF ISOLATED FRAGMENTS OF EMBRYONIC HEART MUSCLE. AB - 1. The Arrhenius equation giving the relationship between the velocity of chemical reaction and temperature, was found suitable for the special case of the contraction rate of embryonic heart muscle fragments. 2. There was no constancy in the values of micro for the rate of contraction in culture, nor was the scattering evenly distributed around certain (more than one) points. 3. There seemed to be no correlation between micro and other functions such as the contraction rate, the site from which the piece was removed, the age of the embryo, etc. PMID- 19872294 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XI. THE PH, CHLORIDE, CARBONIC ACID, AND PROTEIN CONCENTRATIONS IN THE TISSUES AS FUNCTIONS OF AGE. AB - INVESTIGATIONS OF THE CHICKEN EMBRYO DURING ITS INCUBATION PERIOD SHOW THAT: 1. The pH and the chloride concentration of the tissues decrease with age; the fall is most rapid between the 10th and the 13th days of incubation. 2. The concentration of total CO(2) increases with age. This fact is not considered inconsistent with a possible decrease in the concentration of active bicarbonate ions, since the increased CO(2) might well be the result of absorption of calcium carbonate from the shell and its precipitation as bone in the embryo. 3. The concentration of protein increases with age, especially between the 12th and the 16th days of incubation. The fact that the electrolytes change with the greatest rapidity at about 11(1/2) days, the protein at 14 days, and the fat at 16(1/2) days might be taken as a demonstration of the phenomenon of unequal development in the realm of biochemical differentiation and consequently that some notion of order, depending upon molecular reactivity and mobility would describe the process better than any concept of dynamic equilibrium. PMID- 19872295 TI - EFFECT OF HIGH PRESSURE ON GERMINATION OF SEEDS (MEDICAGO SATIVA AND MELILOTUS ALBA). AB - An increase in percentage germination is obtained with seeds of Medicago sativa exposed for 1 to 10 minutes at 2000 atmospheres hydraulic pressure at 20 degrees C., dried, and germinated after 30 days; and from seeds of Melilotus alba under the same conditions of pressure, when exposed for 5 to 30 minutes, dried, and germinated 30 days later. Exposures to 500 atmospheres pressure was less advantageous for germination; the vitality of seeds normally germinating was more rapidly destroyed than the hard impermeable seeds rendered permeable by the pressure treatment. At 0 degrees C., it required approximately 2(1/2) times the exposure to 2000 atmospheres for seeds of Medicago sativa, and approximately 5 times the exposure for seeds of Melilotus alba, as it did at 20 degrees C. PMID- 19872296 TI - BACTERIAL FILTERS : A PRELIMINARY NOTE. PMID- 19872297 TI - ULTRAFILTRATION THROUGH COLLODION MEMBRANES. AB - It is obvious that the factors considered in this paper render data obtained by ultrafiltration open to criticism unless they are checked by other methods and precautions are taken for the elimination of the vitiating effects which have been described. As regards the mechanism of ultrafiltration, the view of a sieve like action as most experimental evidence indicates, is adequate, if all the factors are considered which might modify the effective pore size. The behaviors of collodion membranes which seem contrary to a mechanism of ultrafiltration based on the existence of a system of pores, can be explained on the basis of a variable layer of adsorbed fluid on the walls of the pores. It is, therefore, unsound to make any deductions about living tissues from the demonstration of changes produced in the behavior of collodion membranes. Thus, the increase in the rate of filtration of water through collodion by diuretics (29) or the change of permeability due to the presence of surface-active materials, gives us no information about their action in the living organism. The effect of these substances on a sieve-like membrane of the type of collodion would not necessarily bear any analogy to that exerted on the emulsion type of membrane of living cells. The mechanisms of the reactions necessary to produce the same effects in such widely differing systems may be entirely unrelated. PMID- 19872298 TI - A CONTRIBUTION TO THE THEORY OF PHAGOCYTOSIS. PMID- 19872299 TI - THE PHYSIOLOGICAL PRINCIPLE OF MINIMUM WORK APPLIED TO THE ANGLE OF BRANCHING OF ARTERIES. PMID- 19872300 TI - STUDIES ON ENZYME ACTION : XXXVIII. THE ESTER-HYDROLYZING ACTIONS OF THE WHOLE EEL. AB - The hydrolyzing actions of various preparations of the adult eel were studied on ten esters in the usual way. The results are presented in the form of curves for the relative actions and in a table for the absolute actions obtained in one complete experiment. The separation of the enzyme material in some cases into an active portion and a co-enzyme, the mixture showing greater actions on some esters than the sums of the individual actions, is described and discussed. PMID- 19872301 TI - FURTHER STUDIES ON THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT, WITH SOME OBSERVATIONS ON METHYLENE BLUE. AB - 1. Eosin, erythrosin, rose bengale, cyanosin, acridine, and methylene blue act photodynamically on the luminescence of a Cypridina luciferin-luciferase solution. In presence of these dyes inhibition of luminescence, which without the dye occurs only in blue-violet light, takes place in green, yellow, orange, or red light, depending on the position of the absorption bands of the dye. 2. Inhibition of Cypridina luminescence without photosensitive dye in blue-violet light, or with photosensitive dye in longer wave-lengths, does not occur in absence of oxygen. Light acts by accelerating the oxidation of luciferin without luminescence. Eosin or methylene blue act by making longer wave-lengths effective, but there is no evidence that these dyes become reduced in the process. 3. The luciferin-oxyluciferin system is similar to the methylene white methylene blue system in many ways but not exactly similar in respect to photochemical change. Oxidation of the dye is favored in acid solution, reduction in alkaline solution. However, oxidation of luciferin is favored in all pH ranges from 4 to 10 but is much more rapid in alkaline solution, either in light or darkness. There is no evidence that reduction of oxyluciferin is favored in alkaline solution. Clark's observation that oxidation (blueing) of methylene white occurs in complete absence of oxygen has been confirmed for acid solutions. I observed no blueing in light in alkaline solution. PMID- 19872302 TI - TEMPERATURE CHARACTERISTICS FOR DURATION OF AN INSTAR IN CLADOCERANS. AB - 1. The temperature characteristics for the rate of development during a well defined instar were determined for three species of Cladocera, and found to be of the same general magnitudes as those obtained for rates of development and of O(2) consumption in other arthropods. 2. Critical temperatures were found to occur at points most frequently critical in quite diverse vital phenomena as determined by abrupt changes in the relationship between rate and temperature. 3. A suggestion is made that, since the values of micro and the positions of critical temperatures obtained for the different species are not the same, some relation may exist between the occurrence of these forms in nature and their relative rates of development as controlled by temperatures. PMID- 19872303 TI - THE INFLUENCE OF LIGHT, TEMPERATURE, AND OTHER CONDITIONS ON THE ABILITY OF NITELLA CELLS TO CONCENTRATE HALOGENS IN THE CELL SAP. AB - 1. By the use of a special analytical technique it has been possible to study the accumulation of halogens in the cell sap of Nitella. 2. From a dilute solution, Br may be accumulated in the sap in a concentration much greater than that of the external solution. The conductivity of the sap may be markedly increased by such accumulation. The process is a slow one so that a month or more may be required to approach equilibrium. 3. Cl may be lost from the cell as a result of the accumulation of Br and vice versa. Other reciprocal relations between Cl and Br are indicated. 4. At equilibrium practically as much Br accumulated in the sap with an external solution containing 1 milli-equivalent of Br as with one containing 5 milli-equivalents. 5. Light energy was indispensable to the accumulation of Br. The temperature coefficient was characteristic of a chemical process. PMID- 19872304 TI - THE EFFECT OF THE pH ON THE GERMICIDAL ACTION OF SOAPS. AB - 1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used. 2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect the germicidal titer by modifying the surface tension, the penetration into the bacteria, and the partition coefficient of the germicide between bacteria and water. See PDF for Structure. PMID- 19872305 TI - THE SWELLING PRESSURE OF GELATIN AND THE MECHANISM OF SWELLING IN WATER AND NEUTRAL SALT SOLUTIONS. AB - 1. A method is described for measuring the swelling pressure of solid gelatin. 2. It was found that this pressure increases rapidly between 15 degrees and 37 degrees C., and that the percentage change is nearly independent of the concentration of gelatin. 3. It is suggested that this pressure is due to the osmotic pressure of a soluble constituent of the gelatin held in the network of insoluble fibers, and that gelatin probably consists of a mixture of at least two substances or groups of substances, one of which is soluble in cold water, does not form a gel, and has a low viscosity and a high osmotic pressure. The second is insoluble in cold water, forms a gel in very low concentration, and swells much less than ordinary gelatin. 4. Two fractions, having approximately the above properties, were isolated from gelatin by alcohol precipitation at different temperatures. 5. Increasing the temperature and adding neutral salts greatly increase the pressure of the insoluble fraction and have little effect on that of the soluble fraction. 6. Adding increasing amounts of the soluble fraction to the insoluble one results in greater and greater swelling. 7. These results are considered as evidence for the idea that the swelling of gelatin in water or salt solutions is an osmotic phenomenon, and that gelatin consists of a network of an insoluble substance enclosing a solution of a soluble constituent. PMID- 19872306 TI - THE EFFECT OF pH ON THE PERMEABILITY OF COLLODION MEMBRANES COATED WITH PROTEIN. AB - The permeability of gelatin-coated collodion membranes, as measured by the flow of water or of dilute solutions through the membranes, has been found to vary with the pH of the solutions. The permeability is greatest near the isoelectric point of the protein; with increasing concentration of either acid or alkali it decreases, passes through a minimum, and then increases. These variations with pH are qualitatively in accord with the assumption that they are due to swelling of the gelatin in the pores of the membrane, the effects of pH being similar to those observed by Loeb on the swelling of gelatin granules. Indications have been found of a similar variable permeability in the case of membranes coated with egg albumin, edestin, serum euglobulin, and serum albumin. PMID- 19872307 TI - TEMPERATURE CHARACTERISTICS FOR SPEED OF MOVEMENT OF THIOBACTERIA. AB - The speed of translatory movement of Beggiatoa alba is governed by temperature in such a way that between 5 degrees and 33 degrees the temperature characteristics micro = 16,100 and micro = 8,400 respectively obtain for the temperature ranges 5 degrees to 16.5 degrees and 16.5 degrees to 33 degrees . The "break" at 16 degrees -17 degrees is emphasized by the occurrence of a wider latitude of variation in speed above this temperature. Above 16 degrees the progression of Thiothrix yields micro = 8,300. The possible relation of these values to that previously obtained for similar movement in (photosynthetic) Oscillatoria is commented upon. PMID- 19872308 TI - STEREOTROPISM IN RATS AND MICE. AB - Typical stereotropic orientation toward a lateral surface of contact is obtained in young rats and mice, and with adult mice congenitally blind. Removal of vibrissae or tail or both does not essentially affect this response. Equal contact on both sides of the body prevents orientation toward either source of contact. Unequal contact areas on the two sides leads to orientation toward the more extensive contact. This behavior very exactly parallels the stereotropic conduct of arthropods, and thus provides a fairly complete instance of a tropism in mammals. PMID- 19872309 TI - A SIMPLE ELECTRO-ULTRAFILTER. PMID- 19872310 TI - INTERPRETATION OF THE LACTATION CURVE. AB - The validity of the assumption of a substance determining the rate of milk secretion and undergoing monomolecular destruction, based on group behavior, is questioned on the evidence from a large number of individual lactation curves. It seems probable that the rate of decrease in the rate of milk secretion with advance in lactation is dependent upon factors of a nutritional nature. PMID- 19872311 TI - RATE OF RESPIRATION AS RELATED TO AGE. AB - In the present paper it is shown that as the leaves of corn, sorghum, wheat, and oats increase in age there is a decrease in rate of respiration; but that as the leaves become still older (past about middle age) the rate gradually increases. PMID- 19872312 TI - CONCERNING THE INFLUENCE OF POLARIZED LIGHT ON THE GROWTH OF SEEDLINGS. AB - While these experiments are not exhaustive, a sufficient number have been made to warrant the statement that the effect of polarized light of the visible spectrum on the growth of various seedlings and See PDF for Structure more particularly on the growth of Lupinus albus is somewhat different from that of non-polarized light. This is especially convincing in view of the results obtained with double sets of plants which were alternately exposed to polarized and non-polarized lights of the same intensities and at the same temperature. In every experiment thus performed the set which was placed in a polarizing chamber grew better. It is, furthermore, interesting to note that the phenomenon above observed did not take place when the seed portion of the plants was protected from light by wrapping with tinfoil. This agrees well with previous findings concerning the action of diastase on starch in polarized light. The above researches will be continued on a more elaborate scale but the results so far obtained are deemed worthy of publication in the form of a preliminary communication at the present time. PMID- 19872313 TI - ON CURVES OF GROWTH, ESPECIALLY IN RELATION TO TEMPERATURE. AB - The velocity of growth, taken as the reciprocal of the time required to attain a given size or stage of development, obeys with some exactness the Arrhenius equation for relation to temperature. The values of micro, and the type of "breaks" found in the curves connecting velocity and temperature, are similar to those found in the case of various other vital activities. More precise data, particularly from experiments in which parts of the given developmental stadium are passed at different temperatures, may strengthen present indications that this relationship is not absolute. It is pointed out that the equation for an autocatalytic process, taken as descriptive for growth, predicts particular sorts of deviation under these conditions, which have in one instance been obtained experimentally; and may at the same time nevertheless permit the apparent temperature characteristic for (average) growth velocity to agree rather closely with that for one of the two velocity constants present in the correct autocatalytic equation. PMID- 19872314 TI - EXIT OF DYE FROM LIVING CELLS OF NITELLA AT DIFFERENT pH VALUES. AB - Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene. The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases. The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH(3). PMID- 19872315 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : II. THE ACTION OF THE CHLORIDES OF LEAD, MERCURY, COPPER, IRON, AND ALUMINUM ON THE PROTOPLASM OF AMOEBA PROTEUS. AB - I. Plasmalemma. 1. The order of toxicity of the salts used in these experiments on the surface membrane of a cell, taking as a criterion viability of amebae immersed in solutions for 1 day, is HgCl(2), FeCl(3)> AlCl(3)> CuCl(2)> PbCl(2)> FeCl(2). Using viability for 5 days as a criterion, the order of toxicity is PbCl(2)> CuCl(2)> HgCl(2)> AlCl(3)> FeCl(3)> FeCl(2). 2. The rate of toxicity is in the order FeCl(3)> HgCl(2)> AlCl(3)> FeCl(2)> CuCl(2)> PbCl(2). 3. The ability of amebae to recover from a marked tear of the plasmalemma in the solutions of the salts occurred in the following order: AlCl(3)> PbCl(2)> FeCl(2)> CuCl(2)> FeCl(3)> HgCl(2). II. Internal Protoplasm. 4. The relative toxicity of the salts on the internal protoplasm, judged by the recovery of the amebae from large injections and the range over which these salts can cause coagulation of the internal protoplasm, is in the following order: PbCl(2)> CuCl(2)> FeCl(3)> HgCl(2)> FeCl(2)> AlCl(3). 5. AlCl(3) in concentrations between M/32 and M/250 causes a marked temporary enlargement of the contractile vacuole. FeCl(2), FeCl(3), and CuCl(3) produce a slight enlargement of the vacuole. 6. PbCl(2), in concentrations used in these experiments, appears to form a different type of combination with the internal protoplasm than do the other salts. III. Permeability. 7. Using the similarity in appearance of the internal protoplasm after injection and after immersion to indicate that the surface is permeable to a substance in which the ameba is immersed, it is concluded that AlCl(3) can easily penetrate the intact plasmalemma. CuCl(2) also seems to have some penetrating power. None of the other salts studied give visible internal evidence of penetrability into the ameba. IV. Toxicity. 8. The toxic action of the chlorides of the heavy metals used in these experiments, and of aluminum, is exerted principally upon the surface of the cell and is due not only to the action of the metal cation but also to acid which is produced by hydrolysis. PMID- 19872316 TI - HUMAN GROWTH CURVE. AB - The human growth curve shows two (and only two) outstanding periods of accelerated growth-the circumnatal and the adolescent. The circumnatal growth cycle attains great velocity, which reaches a maximum at the time of birth. The curve of this cycle is best fitted by a theoretical skew curve of Pearson's Type I. It has a theoretical range of 44 months and a standard deviation of 5.17 months. The modal velocity is 10.2 kilos per year. The adolescent growth cycle has less maximum velocity and greater range in time than the circumnatal cycle. The best fitting theoretical curve is a normal frequency curve ranging over about 10 years with a standard deviation of about 21 months and a modal velocity of 4.5 kilos per year. The two great growth accelerations are superimposed on a residual curve of growth which measures a substratum of growth out of which the accelerations arise. This probably extends from conception to 55 years, on the average. It is characterized by low velocity, averaging about 2 kilos per year from 2 to 12 years. It is interpreted as due to many growth operations coincident or closely blending in time. Our curve shows no third marked period of acceleration at between the 3rd and 6th years. The total growth in weight of the body is the sum of the weight of its constituent organs. In some cases these keep pace with the growth of the body as a whole; great accelerations of body growth are due to great accelerations in growth of the constituent organs. In other cases one of the organs of the body (like the thymus gland) may undergo a change in weight that is not in harmony with that of the body as a whole. The development of the weight in man is the resultant of many more or less elementary growth processes. These result in two special episodes of growth and numerous smaller, blending, growth operations. Hypotheses are suggested as to the basis of the special growth accelerations. PMID- 19872317 TI - THE EFFECT OF ENZYME PURITY ON THE KINETICS OF TRYPTIC HYDROLYSIS. AB - The rates of digestion of keratose have been determined with three commercial enzymes, ranging widely in strength. It has been found that the weaker the enzyme preparation, the more nearly does the course of the hydrolysis conform to that of a reaction of the first order. This has been explained on the assumption that in solution an equilibrium exists between active enzyme, and enzyme combined with inert material. In very impure enzyme preparations, the large quantities of combined enzyme act as a reservoir for active enzyme, maintaining a constant concentration of active enzyme during the course of the digestion. PMID- 19872318 TI - TEMPERATURE AND FREQUENCY OF HEART BEAT IN THE COCKROACH. AB - The frequency of pulsation of the intact heart in nymphs (final (?) instar) of Blatta orientalis L. increases with the temperature according to the equation of Arrhenius. The constant micro has typically the same value, within reasonable limits of error, as that (12,200) deduced for other, homologous activities of arthropods where the rate of central nervous discharge is perhaps the controlling element, namely 12,500 +/- calories for temperatures 10-38 degrees C. Below a critical temperature of about 10 degrees a change to a higher value of the temperature characteristic occurs, such that micro = 18,100 +/-. Exceptionally (one individual) micro = 14,100 +/- over the whole range of observed temperature (4.5-28 degrees ). The quantitative correspondence of micro for frequency of heart beat in different arthropods adds weight to the conception that this constant may be employed for the recognition of controlling processes. PMID- 19872319 TI - SOME PHYSICOCHEMICAL PROPERTIES OF DISSOCIATED SPONGE CELLS. AB - 1. The activity of the hydrogen ion, in a system containing 0.00280 mols of NaAc, 0.520 mols of NaCl per liter, and varied amounts of HCl or NaOH has been investigated. The average value of pK' for acetic add in this system is about 4.37. 2. The effect of the addition of various amounts of HCl and NaOH to a system containing 0.00280 mols of NaAc, 0.520 mols of NaCl, and a known number of cells of either Microciona prolifera or Cliona celata was then studied. It was found that in weak acid solutions Microciona behaves as a stronger base than Cliona, the former being practically saturated with base at a pH of 7.5. Similar behavior is shown by suspensions of cells to which no acid or base was added: the cells of Cliona are more acidic than the cells of Microciona. 3. The microscopic examinations of the cells subjected to the treatment with acid or base indicate that the cells of Microciona remain alive down to pH 4.50; the cells of Cliona sustain greater acidity,- a,t pH 3.7 they exhibit no signs of cytolysis. Tests for aggregation of these cells showed that this phenomenon is greatly inhibited even by slightly acid solutions. 4. The conclusion is drawn that the concentration of cells being equal, the suspensions of cells of Microciona and Cliona differ from each other in their physicochemical properties, the comparison being made on suspensions of specified composition. PMID- 19872320 TI - THE GEOTROPIC CONDUCT OF YOUNG RATS. AB - Young rats, old enough to creep well but before the eyelids are open, orient and move upward upon an inclined surface. The angle of geotropic orientation on such a surface (theta) is proportional to the logarithm of the component of gravity parallel to the inclined plane. This result is compared with the scanty information available for other animals; there is indication that it may be generally valid. The precision of the orientation, measured by the percentage dispersion of the individual measurements, also increases in proportion to the logarithm of this component. The cosine of the angle of orientation decreases very nearly in proportion to the sine of the angle of inclination. A possible interpretation of this is given as involving the idea that upward orientation ceases when the differential pull of the body weight upon the opposed legs reaches a threshold value. Attaching weights (W) to the tail causes theta to increase, and in proportion to log W. PMID- 19872321 TI - THE PENETRATION OF BASIC DYE INTO NITELLA AND VALONIA IN THE PRESENCE OF CERTAIN ACIDS, BUFFER MIXTURES, AND SALTS. AB - When living cells of Nitella are exposed to an acetate buffer solution until the pH value of the sap is decreased and subsequently placed in a solution of brilliant cresyl blue, the rate of penetration of dye into the vacuole is found to decrease in the majority of cases, and increase in other cases, as compared with the control cells which are transferred to the dye solution directly from tap water. This decrease in the rate is not due to the lowering of the pH value of the solution just outside the cell wall, as a result of diffusion of acetic acid from the cell when cells are removed from the buffer solution and placed in the dye solution, because the relative amount of decrease (as compared with the control) is the same whether the external solution is stirred or not. Such a decrease in the rate may be brought about without a change in the pH value of the sap if the cells are placed in the dye solution after exposure to a phosphate buffer solution in which the pH value of the sap remains normal. The rate of penetration of dye is then found to decrease. The extent of this decrease is the greater the lower the pH value of the solution. It is found that hydrochloric acid and boric acid have no effect while phosphoric acid has an inhibiting effect at pH 4.8 on stirring. Experiments with neutral salt solutions indicate that a direct effect on the cell (decreasing penetration) is due to monovalent base cations, while there is no such effect directly on the dye. It is assumed that the effect of the phosphate and acetate buffer solutions on the cell, decreasing the rate of penetration, is due (1) to the penetration of these acids into the protoplasm as undissociated molecules, which dissociate upon entrance and lower the pH value of the protoplasm or to their action on the surface of the protoplasm, (2) to the effect of base cations on the protoplasm (either at the surface or in the interior), and (3) possibly to the effect of certain anions. In this case the action of the buffer solution is not due to its hydrogen ions. In the case of living cells of Valonia under the same experimental conditions as Nitella it is found that the rate of penetration of dye decreases when the pH value of the sap increases in presence of NH(3), and also when the pH value of the sap is decreased in the presence of acetic acid. Such a decrease may be brought about even when the cells are previously exposed to sea water containing HCl, in which the pH value of the sap remains normal. PMID- 19872322 TI - THE ROLE OF CERTAIN METALLIC IONS AS OXIDATION CATALYSTS. AB - 1. When iron and copper are allowed to act on hydrogen peroxide and pyrogallol, enough carbon dioxide is produced to be readily measured. 2. The curve of the production of carbon dioxide may be fitted by an empirical equation, by the use of which the initial rate and the total amount of the oxidation may be determined. 3. The effect of the concentration of the reagents is different in each case, the effect varying as a fractional power of the copper and pyrogallol concentrations and as a logarithmic function of the hydrogen peroxide concentration. 4. When gold or silver is used the rate changes suddenly during the course of the reaction due to the precipitation of colloidal metal. 5. Mercury, cadmium, zinc, tin, and some other metals have no effect. 6. A theoretical set of equations is assumed to account for the action of the metals. 7. The metals are assumed to act by means of the formation of intermediate peroxides. 8. Experiments on the action of gold indicate that the metals are active in the ionic and not in the colloidal state. PMID- 19872323 TI - AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : I. THEORETICAL. AB - The amphoteric behavior of a system of two amphoteric components is theoretically examined; and this is shown to correspond more nearly with certain of the physical and chemical behaviors of living tissues than does the concept of a simple ampholyte. PMID- 19872324 TI - AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : II. TITRATION OF SULFANILIC ACID-GLYCINE MIXTURES. AB - Electrometric titrations of glycine, sulfanilic acid, and various mixtures of the two have been made. These mixtures are shown to give a curve which, between their respective isoelectric points, is different from that of either substance. These mixtures have a maximum buffering power at a pH which can be theoretically calculated, and which has the characteristics of an "isoelectric point of the system." Other pairs of ampholytes are shown to act in an analogous manner. PMID- 19872325 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XII. THE METABOLISM AS A FUNCTION OF AGE. AB - 1. The previous findings that the rate of metabolism per gm. of body weight decreased with age, and that during the incubation period catabolism was mostly at the expense of fat, have been confirmed. 2. These determinations of the rate of oxygen uptake have afforded more precise values for the catabolic rate and thus permit estimations of the changes with age in the rate of absorption. PMID- 19872326 TI - REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH. AB - The normal reaction of the coelomic fluid in Patiria miniata and Asterias ochraceus is pH 7.6, and of the caeca, 6.7, compared with sea water at 8.3, all without salt error correction. A medium at pH 6.7-7.0 is optimum for the caeca for ciliary survival and digestion of protein, and is maintained by carbon dioxide production. The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It does not represent an elimination gradient for carbon dioxide. Because the normal excised caeca maintain a definite hydrogen ion concentration and change their internal environment toward that as an optimum during life, there exists a regulatory process which is an important vital function. PMID- 19872327 TI - STUDIES ON ENZYME ACTION : XXXIX. LIPASE ACTIONS OF EXTRACTS OF THE WHOLE MOUSE AT DIFFERENT AGES. AB - The ester-hydrolyzing or lipase actions of extracts of whole mice whose ages ranged from approximately 6 days before birth to 1 year 8 months 21 days were tested on ten simple esters by the method described in previous papers. The "pictures" of the relative enzyme actions changed from a type approaching the "embryonic" as found with embryo rats and a number of tissues of rabbit embryo, to a type characteristic of the adult mouse. The mouse embryos corresponded to the rat embryos in type and differed markedly from the mouse carcinomas which have been studied. The relative and absolute enzyme actions are discussed in some detail, and the results compared with the results obtained for the life cycle of the rat. PMID- 19872328 TI - AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : III. THE CONDUCTIVITY OF SULFANILIC ACID LYSIN MIXTURES. AB - Conductivities of sulfanilic acid, lysin, and mixtures of the two were made over a wide pH range, the pH being adjusted by means of phosphate buffers. The actual conductivities of the sulfanilic acid, the lysin, and the mixture were calculated. The difference between the conductivity of the mixture and the sum of the conductivities of the components alone passes through a maximum at a pH theoretically calculable as the isoelectric point of the system. Certain applications of the results are made to the explanation of the behavior of living tissues. PMID- 19872329 TI - AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : IV. NOTE ON THE ISOELECTRIC POINT AND IONIZATION CONSTANTS OF SULFANILIC ACID. AB - From the solubility minimum the value of the basic ionization constant of sulfanilic acid is shown to lie probably between the values 1.7 x 10(-15) and 3.2 x 10(-15). From solubility measurements the value of this same constant is shown to lie probably between 2.0 and 2.2 x 10(-15), and the isoelectric point of sulfanilic acid is thus at a cH of 0.056 or a pH of 1.25. From conductivity ratios the acid ionization constant of sulfanilic acid is shown to be 7.05 x 10( 4) at room temperature (21 degrees C.). Calculations are made, from data published in preceding papers, of the ionization constants of glycine, K(a) being 2.3 x 10(-10), and K(b) being 2.2 x 10(-12). PMID- 19872330 TI - THE OXIDATION-REDUCTION POTENTIAL OF THE LUCIFERIN-OXYLUCIFERIN SYSTEM. AB - The oxidation-reduction potential of the Cypridina luciferin-oxyluciferin system determined by a method of "bracketing" lies somewhere between that of anthraquinone 2-6-di Na sulfonate (E(o) (') at pH of 7.7 = -.22) which reduces luciferin, and quinhydrone (E(o) (') at pH of 7.7 = +.24), which oxidizes luciferin. Systems having an E(o) (') value between -.22 and +.24 volt neither reduce oxyluciferin nor oxidize luciferin. If the luciferin-oxyluciferin system were truly reversible considerable reduction and oxidation should occur between .22 and +.24. The system appears to be an irreversible one, with both "apparent oxidation" and "apparent reduction potentials" in Conant's sense. Hydrosulfites, sulfides, CrCl(2), TiCl(3), and nascent hydrogen reduce oxyluciferin readily in absence of oxygen but without luminescence. Luminescence only appears in water solution if luciferin is oxidized by dissolved oxygen in presence of luciferase. Rapid oxidation of luciferin by oxygen without luciferase or oxidation by K(3)Fe(CN)(6) in presence of luciferase but without oxygen never gives luminescence. PMID- 19872331 TI - GALVANOTROPISM AND "REVERSAL OF INHIBITION" BY STRYCHNINE. AB - The cathodically galvanotropic orientation of nemerteans, Lineus, and the anodic orientation of the gephyrean Echiurus, are reversed by the action of strychnine under conditions such that the typical "reversal of inhibition" induced by this substance is apparent. Nicotine does not give this result. Since it is necessary to assume that the strychnine effect is due to action upon the central ganglia, and since the galvanotropic effect depends upon action of the current on nerve cell bodies of the central ganglia, it must be assumed that the locus of reversal by strychnine is not perikaryal, but presumably synaptic. PMID- 19872332 TI - PHOTOTROPISM IN YOUNG RATS. AB - Before the eyelids have opened young rats are negatively heliotropic. They behave very much as does the larva of the blow-fly. The angle of orientation by lights opposed at 180 degrees may be calculated by an equation based upon the elementary requirement of phototropism, namely that orientation is attained when the illumination of bilaterally disposed photoreceptors is equal. The precision of orientation decreases very nearly in proportion to the sum of the logarithms of the acting light intensities, due to photokinetic head movements. When the eyelids are opened, the rats move toward a darkened place in the field of vision, usually toward the shaded region immediately to one side of the lamp house. Therefore, when heliotropic, the rat is not "seeking the dark". The phototropism of these animals may be brought into conflict with their pronounced stereotropism, and the resolution of such conflicts may perhaps be utilized for the investigation of central nervous states. PMID- 19872333 TI - ON THE EQUILIBRATION OF GEOTROPIC AND PHOTOTROPIC EXCITATIONS IN THE RAT. AB - The intensity of light required to just counterbalance geotropic orientation of young rats, with eyelids unopened, is so related to the angle of inclination (alpha) of the creeping plane that the ratio log I/log sin alpha is constant. This relationship, and the statistical variability of I as measured at each value of alpha, may be deduced from the known phototropic and the geotropic conduct as studied separately, and affords proof that in the compounding of the two kinds of excitation the rat is behaving as a machine. PMID- 19872334 TI - CERTAIN EFFECTS OF SALTS ON THE PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA. AB - The effect of various substances on living cells may be advantageously studied by exposing them to such substances and observing their subsequent behavior in solutions of a basic dye, brilliant cresyl blue. The rate of penetration of the basic dye, brilliant cresyl blue, is decreased when cells are exposed to salts with monovalent cations before they are placed in the dye solution (made up with borate buffer mixture). This inhibiting effect is assumed to be due to the effect of the salts on the protoplasm. This effect is not readily reversible when cells are transferred to distilled water, but it is removed by salts with bivalent or trivalent cations. In some cases it disappears in dye made up with phosphate buffer mixture, or with borate buffer mixture at the pH value in which the borax predominates, and in the case of NaCl it disappears in dye containing NaCl. No inhibiting effect is seen when cells are exposed to NaCl solution containing MgCl(2) before they are placed in the dye solution. The rate of penetration of dye is not decreased when cells are previously exposed to salts with bivalent and trivalent cations. The rate is slightly increased when cells are placed in the dye solution containing a salt with monovalent cation and probably with bivalent or trivalent cations. In the case of the bivalent and trivalent salts the increase is so slight that it may be negligible. PMID- 19872335 TI - THE STAGES OF THE PEPTIC HYDROLYSIS OF EGG ALBUMIN. AB - 1. Most of the products of the peptic hydrolysis of albumin, about 85 per cent of the total N, are primary in the sense that they arise directly from the protein molecule, and undergo no further hydrolysis. 2. A slow secondary hydrolysis, involving about 15 per cent of the total N, occurs in the proteose and simpler fractions primarily split off. 3. Acid metaprotein in peptic hydrolysis arises as a result of the action of acid. It is not an essential stage in the hydrolysis of undenatured albumin. 4. Acid metaprotein is hydrolyzed by pepsin more slowly under comparable conditions than undenatured albumin. PMID- 19872336 TI - THE AUTODESTRUCTION OF PEPSIN IN RELATION TO ITS IONIZATION. AB - 1. Evidence is presented that pepsin is a univalent acid with a value for pK of 6.85 (or a base, with pK 7.39). 2. The autodestruction of the pepsin is shown to be dependent in part upon an instantaneous irreversible change occurring in the ionized form of the enzyme (if it be an acid) or in the unionized form (if it be a base). 3. A further progressive autodestruction of pepsin at any given hydrogen ion concentration and temperature is defined by the mass law equation for a monomolecular reaction 4. The velocity of autodestruction of pepsin is directly proportional to the hydroxyl ion concentration. It is much less in the range of hydroxyl ion concentration from pOH 9.89-7.7, than in the range greater than pOH 7.7. In both of these ranges variations in pK with pOH may be represented by straight lines. PMID- 19872337 TI - THE EFFECT OF CERTAIN RESPIRATORY INHIBITORS ON THE RESPIRATION OF CHLORELLA. AB - Chlorella, when made heterotrophic by means of certain sugars, respires like other heterotrophic cells when subjected to the respiratory inhibitors, hydrocyanic acid, hydrogen sulfide, and carbon monoxide. Whether the case of Chlorella is typical for green cells in general remains to be seen. Experiments with various other green organisms are being carried out, in hope of settling this point. PMID- 19872338 TI - THERMAL INCREMENTS FOR PULSATION-FREQUENCY IN "ACCESSORY HEARTS" OF NOTONECTA. AB - The frequencies of pulsation of the "accessory hearts" in the isolated swimming legs of Notonecta were studied in relation to temperature, with the idea that in such organs central nervous control is impossible, and that in an isolated system irreversibly proceeding toward death it might be expected that further evidence would be found regarding the supposed specific significance of critical thermal increments. A number of values of micro are found, commonly 8,200; 16,200; or 32,200; less frequently 11,400; 19,800; and 24,500. These values are definitely contrasted with that (12,300) typical for heart beat frequencies in arthropods. They exhibit interrelationships of the sorts already found in other cases. There occur also sharp irreversible changes in frequency of pulsation, which may or may not be accompanied by change of increment. The net result is held to be confirmatory of the interpretation of thermal relations proposed in earlier papers. PMID- 19872339 TI - TEMPERATURE AND FREQUENCY OF CARDIAC CONTRACTIONS IN EMBRYOS OF LIMULUS. AB - Temperature characteristics for frequency of myogenic heart beat in Limulus embryos, before the onset of nervous control of the heart, were found to be 11,500; 16,400; 20,000; 25,500. The two first values are the best established. The different values pertain to the hearts of different individuals outwardly similar, and to the hearts of single embryos in different parts of the temperature range. These values differ from that known in connection with the control of the heart beat through the cardiac ganglion. The occurrence of critical temperatures, also, is not the same in all embryos. These facts are employed in a discussion of temperature relations in pulsating explants of chick myocardium. PMID- 19872340 TI - GEOTROPIC ORIENTATION OF YOUNG RATS. AB - The geotropic orientation of Rattus rattus (roof rat) obeys the equations previously found applicable for Rattus norvegicus. The former is more sensitive, geotiopically, and the numerical values of the constants in the equations for the two forms are found to differ significantly. Certain consequences of this difference are pointed out. PMID- 19872341 TI - GEOTROPIC CREEPING OF YOUNG RATS. AB - The rate of upward creeping in negatively geotropic rats aged 13 to 14 days is a function of the gravitational stimulus. The rate of upward movement on the creeping plane, like the angle of orientation, is directly proportional to the logarithm of the gravity component. The variability in the speed of creeping decreases in proportion to the logarithm of the gravitational effect. When weights are attached to the animals' tails the rate of upward creeping varies almost directly as the logarithm of the attached weight, and the speed of creeping is still proportional to the angle of upward orientation. PMID- 19872342 TI - THE PRECISE MEASUREMENT OF HEMOLYSIN. AB - A method is described for the measurement of hemolysin concentration, which makes possible exact comparison of results obtained at different times and with different specimens of erythrocytes and alexin; and gives precise values with an error not greater than 2 per cent. PMID- 19872343 TI - THE PROTEIN ASSOCIATED WITH HEMOLYSIN IN RABBIT SERUM AND PLASMA. AB - 1. The water-insoluble globulin with which hemolysin is associated, may be separated from immune serum or plasma by dilution and simple dialysis at optimal pH. 2. This optimum in plasma is influenced by the presence of the fibrinogen. 3. Fibrinogen carries no immune body, or only an insignificant amount; when present in immune body solutions in other form than fibrin gel, it depresses the hemolytic activity. The conditions for the formation of fibrin gel are similar to those for the formation of a gel by banana protein. 4. The hemolytic activity is a more labile property of the immune protein than the agglutinating activity; hemolysin is destroyed, hemagglutinin shows an apparent increase, as a result of alcohol extraction. PMID- 19872344 TI - "GALVANOTROPISM" OF ROOTS. AB - 1. New experiments, made in such a way to eliminate as completely as possible products of polarization and the migration of such products when formed, have shown that the exhibition of galvanotropic curvature in roots is mainly dependent upon such products, since no curvature appears when they are excluded. 2. The polarization products injure the external layer of cells of the root; this allows these cells to act as electrodes directly applied on the internal tissues. The inner electrolysis produces such changes in the interior cells that they may be considered as becoming ionically different. This differential state is responsible for curvature. 3. "Galvanotropism" of roots, therefore, cannot be regarded as exactly comparable to the galvanotropic orientations of certain animals, but is essentially dependent upon injury. PMID- 19872345 TI - THE FREE ENERGY OF NITROGEN FIXATION BY LIVING FORMS. AB - Fixation of nitrogen even with liberation of energy or free energy, will take place if either oxygen gas or hydrogen gas, or other substances, especially gases, whose standard free energies are close to zero, are involved to form either nitrates, ammonia, or cyanide, not to speak of still other compounds. It has been pointed out that there are two and only two general conditions where nitrogen fixation can require energy. These are, first, if nitrogen reacts with some compound like water with an already high negative free energy of formation and where negligible oxidation of nitrogen would occur; second, if the plant does not take advantage of working at concentrations where the process would yield free energy. If nitrogen fixation is exothermic and free energy-yielding, how is the carbohydrate requirement of nitrogen-fixing organisms to be interpreted? Are the experimental determinations of the carbon to nitrogen ratio purely circumstantial? Is further hope given to those who may experimentally try to narrow this ratio to where the carbon used is only for the carbon requirements of general metabolism, exclusive of fixation? Do not hypotheses concerning the fixation of nitrogen in the evolutionary process, which are based on the conception that energy is required, lose some of their significance? Does it not suggest that perhaps fixation is far more universal than is supposed among living forms, particularly among the higher green plants, and thereby give encouragement to those who may wish to demonstrate this experimentally? Does it not indicate that perhaps the function of fixation is often to obtain energy for use in general metabolism? Is the general carbohydrate metabolism of the fixation forms to be regarded as being merely extremely inefficient? Or most suggestive of all, is the carbohydrate serving some unobserved function? PMID- 19872346 TI - STUDIES ON PERMEABILITY OF MEMBRANES : I. INTRODUCTION AND THE DIFFUSION OF IONS ACROSS THE DRIED COLLODION MEMBRANE. AB - The theoretical aspects of the problem of sieve-like membranes are developed. The method of preparing the dried collodion membrane is described, and the method of defining the property of a particular membrane is given. It consists of the measurement of the Co P, that is the P.D. between an 0.1 and an 0.01 M KCl solution separated by the membrane. Co P is in the best dried membranes 50 to 53 millvolts, the theoretically possible maximum value being 55 millivolts. Diffusion experiments have been carried out with several arrangements, one of which is, for example, the diffusion of 0.1 M KNO(3) against 0.1 M NaCl across the membrane. The amount of K(+) diffusing after a certain period was in membranes with a sufficiently high Co P (about 50 millivolts or more) on the average ten times as much as the amount of diffused Cl(-). In membranes with a lower Co P the ratio was much smaller, down almost to the proportion of 1:1 which holds for the mobility of these two ions in a free aqueous solution. When higher concentrations were used, e.g. 0.5 M solution, the difference of the rate of diffusion for K(+) and Cl(-) was much smaller even in the best membranes, corresponding to the fact that the P.D. of two KCl solutions whose concentrations are 10:1 is much smaller in higher ranges of concentration than in lower ones. These observations are confirmed by experiments arranged in other ways. It has been shown that, in general, the diffusion of an anion is much slower than the one of a cation across the dried collodion membrane. The ratio of the two diffusion coefficients would be expected to be calculable in connection with the potential difference of such a membrane when interposed between these solutions. The next problem is to show in how far this can be confirmed quantitatively. PMID- 19872347 TI - PHOSPHATE ION AS A PROMOTER CATALYST OF RESPIRATION. AB - The active component of phosphate solutions, in relation to promoter action on oxidising enzymes, is the PO(4) (''') ion. This is shown by the demonstration of a hyperbolic relationship between per cent production of CO(2) (of Elodea) and pPO(4), the measure of the phosphate ion potential. This is consistent with the rate of respiration as affected by changing pPO(4) through change of total phosphate concentration while pH is kept constant. The equation for this relationship is (CO(2) - a) (pPO(4) - b)(n) = K where a, b, n, and K are constants and n = 1. The same relationship to phosphate ion concentration, expressed by the equation (Activity of enzyme) (pPO(4))(n) = K, where n and K are constants and n varies from 1 to 6 under different conditions, appears to hold for some other enzyme actions, including those of peroxidase and pancreatic lipase. PMID- 19872348 TI - ARSENATE AS A CATALYST OF OXIDATION. AB - Arsenate exerts a catalytic effect on the oxidation of pyrogallol by atmospheric oxygen, on the catalytic oxidation of pyrogallol by metallic iron, and on the presumably enzymatic production of CO(2) by Elodea canadensis. PMID- 19872349 TI - A THEORETICAL CONSIDERATION OF THE ACTION OF X-RAYS ON THE PROTOZOAN COLPIDIUM COLPODA. AB - 1. The theory which Crowther has advanced to account for the variation of the lethal dose of roentgen rays among the individuals of a group of Colpidium colpoda is reviewed. 2. It is shown that the use of his small-body theory to explain the small value of lambda(e) leads to certain further assumptions about the nature of the destructive effect. 3. An alternative hypothesis is discussed. PMID- 19872350 TI - TIME RELATIONS OF GROWTH : III. GROWTH CONSTANTS DURING THE SELF-ACCELERATING PHASE OF GROWTH. AB - Growth curves consist, in all cases, of two major segments. The first major segment is, in the case of higher animals and plants, made up in turn of several (probably five) shorter segments during each of which growth takes place at a constant percentage rate. The transitions between the successive stages are abrupt, the abruptness being of the order of metamorphosis in cold blooded animals. It has been made clear in the first paper of this series that the time rate of growth following the major inflection declines at a constant percentage rate. The junction between the two major segments occurs at puberty in animals and flowering in plants. The two major segments are not symmetrical about the major inflection. The slope of the segment following the inflection is always less than the slope of the segment preceding the inflection. The major inflection does not occur in the center of the growth curve. The instantaneous rate of growth at the beginning of growth is of the order of 100-200 per cent per day (i.e. the body weight is doubled in from 7 to 17 hours). It may be mentioned that 2 months after conception the rate of growth in man is only 8 per cent per day. This is contrary to all the published statements. Thus, Minot concluded that growth begins at 1000 per cent per day; Jackson concluded that in man, growth during the 1st month takes place at 57.5 million per cent per month; during the 2nd month 990 per cent per month; during the 3rd month 390 per cent per month (8 per cent per day is only 240 per cent per month). The reason for the discrepancy between the values derived, by the method adopted by the writer, and the values given in the literature is explained by Fig. 1. PMID- 19872351 TI - THE KINETICS OF EXOSMOSIS OF WATER FROM LIVING CELLS. AB - 1. The rate of exosmosis of water was studied in unfertilized Arbacia eggs, in order to bring out possible differences between the kinetics of exosmosis and endosmosis. 2. Exosmosis, like endosmosis, is found to follow the equation See PDF for Equation, in which a is the total volume of water that will leave the cell before osmotic equilibrium is attained, x is the volume that has already left the cell at time t, and k is the velocity constant. 3. The velocity constants of the two processes are equal, provided the salt concentration of the medium is the same. 4. The temperature characteristic of exosmosis, as of endomosis, is high. 5. It is concluded that the kinetics of exosmosis and endosmosis of water in these cells are identical, the only difference in the processes being in the direction of the driving force of osmotic pressure. PMID- 19872352 TI - THE EFFECT OF SALT CONCENTRATION OF THE MEDIUM ON THE RATE OF OSMOSIS OF WATER THROUGH THE MEMBRANE OF LIVING CELLS. AB - 1. Using the unfertilized egg of the sea urchin, Arbacia, as osmometer, it was found that the rate with which water enters or leaves the cell depends on the osmotic pressure of the medium: the velocity constant of the diffusion process is higher when the cell is in concentrated sea water, and lower when the sea water medium is diluted with distilled water. Differences of more than tenfold in the value of the velocity constant were obtained in this way. When velocity constants are plotted against concentration of medium, a sigmoid curve is obtained. 2. These results are believed to indicate that cells are more permeable to water when the osmotic pressure of the medium is high than when it is low. This relation would be accounted for if water should diffuse through pores in a partially hydrated gel, constituting the cell membrane. In a medium of high osmotic pressure, the gel is conceived to give up water, to shrink, and therefore to allow widening of its pores with more ready diffusion of water through them. Conversely, in solutions of lower osmotic pressure, the gel would take up water and its pores become narrow. PMID- 19872353 TI - STUDIES ON THE PERMEABILITY OF MEMBRANES : II. DETERMINATION OF IONIC TRANSFER NUMBERS IN MEMBRANES FROM CONCENTRATION CHAINS. AB - The ionic transfer number in an electrolyte solution in the pores of a narrow pored collodion membrane depends much more on the concentration than it does in a free aqueous solution. The potential difference of two solutions of the same electrolyte in different concentration depends largely on the concentration range. The ratio of the concentrations on the two sides was always 1:2 in the experiments; the concentration range was varied. It is shown that the transfer number of Cl, calculated from the P.D. measured, is very small in dilute solution (down to .02 and less in some cases), whereas it approaches the value .5 holding for free aqueous solutions when the concentration range is raised. The differences for the transfer number of Cl, according to the cation (H, K, Na, Li), can be recognized and show the same order as in free aqueous solution. But even in LiCl, where in an ordinary aqueous solution the transfer number of Cl is always > .5, this number is very low in the case of the membrane (e.g. < .05 in .01 M solution). PMID- 19872354 TI - STUDIES ON THE PERMEABILITY OF MEMBRANES : III. ELECTRIC TRANSFER EXPERIMENTS WITH THE DRIED COLLODION MEMBRANE. AB - The transfer numbers of the ions of electrolytes in the dried collodion membrane, as determined in a previous paper indirectly from the E.M.F. of concentration chains, can also be determined directly by electrical transfer experiments. It is shown that the difficulties involved in such experiments can be overcome. The transfer numbers obtained by the two methods are in satisfactory agreement. The experimental results obtained in the transfer experiments furnish an additional argument in favor of maintaining the theory that the electromotive effects observed in varying concentrations of different electrolytes with the dried collodion membrane may be referred to differences in the mobilities of the anions and cations within the membrane. As was shown by the method of the previous paper, the transfer number depends largely on concentration. There are some minor discrepancies between the values of the transfer numbers obtained by the two methods which, as yet, cannot be completely explained. PMID- 19872355 TI - THE ACTIVATION OF STARFISH EGGS BY ACIDS : II. THE ACTION OF SUBSTITUTED BENZOIC ACIDS AND OF BENZOIC AND SALICYLIC ACIDS AS INFLUENCED BY THEIR SALTS. AB - 1. Comparison of the rates of activation of unfertilized starfish eggs in pure solutions of a variety of parthenogenetically effective organic acids (fatty acids, carbonic acid, benzoic and salicylic acids, chloro- and nitrobenzoic acids) shows that solutions which activate the eggs at the same rate, although widely different in molecular concentration, tend to be closely similar in C(H). The dissociation constants of these acids range from 3.2 x 10(-7) to 1.32 x 10( 3). 2. In the case of each of the fourteen acids showing parthenogenetic action the rate of activation (within the favorable range of concentration) proved nearly proportional to the concentration of acid. The estimated C(H) of solutions exhibiting an optimum action with exposures of 10 minutes (at 20 degrees ) lay typically between 1.1 x 10(-4)M and 2.1 x 10(-4)M (pH = 3.7-3.96), and in most cases between 1.6 x 10(-4)M and 2.1 x 10(-4)M (pH = 3.7-3.8). Formic acid (C(H) = 4.2 x 10(-4)M) and o-chlorobenzoic acid (C(H) = 3.5 x 10(-4)M) are exceptions; o nitrobenzoic acid is ineffective, apparently because of slow penetration. 3. Activation is not dependent on the penetration of H ions into the egg from without, as is shown by the effects following the addition of its Na salt to the solution of the activating acid (acetic, benzoic, salicylic). The rate of activation is increased by such addition, to a degree indicating that the parthenogenetically effective component of the external solution is the undissociated free acid. Apparently the undissociated molecules alone penetrate the egg freely. It is assumed that, having penetrated, they dissociate in the interior of the egg, furnishing there the H ions which effect activation. 4. Attention is drawn to certain parallels between the physiological conditions controlling activation in the starfish egg and in the vertebrate respiratory center. PMID- 19872356 TI - A RELATIONSHIP BETWEEN CIRCUMFERENCE AND WEIGHT IN TREES AND ITS BEARING ON BRANCHING ANGLES. AB - Observation reveals a linear relationship between the logarithm of the circumference of a tree, branch, or leaf stem, and the logarithm of the weight of the tree, branch, or leaf. The bearing of this on the angles of branching in trees is discussed. PMID- 19872357 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : III. THE ACTION OF CO(2)AND SOME SALTS OF NA, CA, AND K ON THE PROTOPLASM OF AMOEBA DUBIA. AB - I. Plasmalemma. 1. Of the salts used in these experiments the anions have only a modifying effect on the cations. The dispersive action of Na and, to a lesser extent, of K, predominates. Borate increases the toxicity of Na and acetate decreases it. 2. CO(2) and carbonates dissolve the plasmalemma readily. 3. Na lactate tends to dissolve the surface especially when brought into contact with it from the interior by injection. Lactate antagonizes the stimulating effect of Ca on the plasmalemma. II. The Internal Protoplasm. 4. Acid phosphate of Na and K, when injected, causes a membrane to form around the granular endoplasm within the ameba. 5. Na borate increases the toxicity of Na inside the cell. 6. Bubbles of CO(2), injected into the cell, cause an increase of fluidity of the internal protoplasm. These bubbles shrink and disappear from the cell more readily than air bubbles. 7. The anions modify the typical cation effect. Carbonates accentuate the liquefying and solvent action of Na. Phosphates prevent a complete rounding of the ameba caused by Na. Lactate inhibits the solidification and pinching off effect caused by Ca. III. Physiological Significance of Salts. 8. The buffer salts can be injected in high concentrations without toxic effects but amebae can be immersed in them only in very dilute solutions without injury. 9. The inhibiting action of lactate and the dispersive effect of CO(2), carbonates, and lactate on the plasma membrane, must be of importance in a consideration of the functions of the organism and perhaps in the production of pathological changes. PMID- 19872358 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : IV. COLORIMETRIC DETERMINATION OF THE NUCLEAR AND CYTOPLASMIC pH IN THE STARFISH EGG. AB - I. Cytoplasm. 1. The normal cytoplasmic pH, colorimetrically determined, of the starfish eggs in the unfertilized, fertilized, and first and second cleavage stages is 6.7 +/- 0.1. 2. Cytolysis lowers the pH to a value 5.5 +/- 0.1. 3. The cytolyzed material in time assumes the pH of its environing sea water. 4. The acid due to mechanical injury can also be detected in the environment of the egg. 5. Injury to the cytoplasm unaccompanied by visible disintegration causes an increase in acidity which is quickly neutralized. II. Germinal Vesicle. 6. The intranuclear pH, colorimetrically determined, of the immature Asterias egg is 7.5 +/- 0.1. 7. Injury to the nucleus does not change its pH. 8. The spherical nuclear remnant which persists after injury gradually assumes the pH of its environment. III. Plasmalemma. 9. A dye to which the cell is normally impermeable can penetrate through a tear in the surface from an environment more acid than normal. This may be due to a difference in the formation of the plasmalemma in a normal and an acid medium. PMID- 19872359 TI - GEOTROPISM OF AGRIOLIMAX. AB - On an inclined glass plate the slug Agriolimax orients and creeps upward or downward. The angle of orientation on the plane (theta) is proportional to the logarithm of the component of gravity in the creeping plane. The coefficient of variability of the measured values of (theta) decreases linearly as the logarithm at the gravity component in the creeping plane increases. The cosine of the angle of orientation decreases almost directly in proportion to the sine of the angle of inclination of the creeping plane to the horizontal, as previously found for young rats (Crozier and Pincus). But a more satisfactory formulation for the present case shows that the sine of the angle of orientation (theta) decreases in direct proportion to the increase of the reciprocal of the sine of the angle of inclination of the creeping plane. This formulation is derived from the theory that the geotropic orientation is limited by the threshold difference between the pull of the body mass on the mutually inclined longitudinal muscles at the anterior end of the slug. PMID- 19872360 TI - THE OXYGEN CONSUMPTION OF FROG NERVE DURING STIMULATION. AB - 1. The resting rate of oxygen consumption of the excised sciatic nerve of the frog is 1.23 c.mm. of oxygen per gm. of nerve per minute. 2. During stimulation with an induction coil with 100 make and 100 break shocks per second there is an excess oxygen consumption amounting on the average to 0.32 c.mm. of oxygen per gm. of nerve per minute of stimulation, or a 26 per cent increase over the resting rate. 3. The magnitude of the excess oxygen consumption in stimulation, in agreement with the all-or-none law, is not markedly influenced by considerable variations in the intensity of stimulation. 4. Increasing the frequency of stimulation from 100 to 200 shocks per second increases the extra oxygen used only 1.12-1.18 times. The same change in frequency of stimulation increases the negative variation 1.15 times and the heat production about 1.25 times (Hill). 5. This parallelism between the excess oxygen and the negative variation argues definitely for some causal connection between the excess oxygen and the nerve impulse itself. 6. Calculation shows that the oxygen tension inside these nerves was not zero. PMID- 19872361 TI - THE KINETICS OF DARK ADAPTATION. AB - 1. Data are presented for the dark adaptation of four species of animals. They show that during dark adaptation the reaction time of an animal to light of constant intensity decreases at first rapidly, then slowly, until it reaches a constant minimum. 2. On the assumption that at all stages of adaptation a given response to light involves a constant photochemical effect, it is possible to describe the progress of dark adaptation by the equation of a bimolecular reaction. This supposes, therefore, that dark adaptation represents the accumulation within the sense cells of a photosensitive material formed by the chemical combination of two other substances. 3. The chemical nature of the process is further borne out by the fact that the speed of dark adaptation is affected by the temperature. The velocity constant of the bimolecular process describing dark adaptation bears in Mya a relation to the temperature such that the Arrhenius equation expresses it with considerable exactness when micro = 17,400. 4. A chemical mechanism is suggested which can account not only for the data of dark adaptation here presented, but for many other properties of the photosensory process which have already been investigated in these animals. This assumes the existence of a coupled photochemical reaction of which the secondary, "dark" reaction is catalyzed by the products of the primary photochemical reaction proper. This primary photochemical reaction itself is reversible in that its main products combine to form again the photosensitive material, whose concentration controls the behavior of the system during dark adaptation. PMID- 19872362 TI - HYDRATION OF GELATIN IN SOLUTION. AB - 1. It was shown that the high viscosity of gelatin solutions as well as the character of the osmotic pressure-concentration curves indicates that gelatin is hydrated even at temperatures as high as 50 degrees C. 2. The degree of hydration of gelatin was determined by means of viscosity measurements through the application of the formula See PDF for Equation. 3. When the concentration of gelatin was corrected for the volume of water of hydration as obtained from the viscosity measurements, the relation between the osmotic pressure of various concentrations of gelatin and the corrected concentrations became linear, thus making it possible to determine the apparent molecular weight of gelatin through the application of van't Hoff's law. The molecular weight of gelatin at 35 degrees C. proved to be 61,500. 4. A study was made of the mechanism of hydration of gelatin and it was shown that the experimental data agree with the theory that the hydration of gelatin is a pure osmotic pressure phenomenon brought about by the presence in gelatin of a number of insoluble micellae containing a definite amount of a soluble ingredient of gelatin. As long as there is a difference in the osmotic pressure between the inside of the micellae and the outside gelatin solution the micellae swell until an equilibrium is established at which the osmotic pressure inside of the micellae is balanced by the total osmotic pressure of the gelatin solution and by the elasticity pressure of the micellae. 5. On addition of HCl to isoelectric gelatin the total activity of ions inside of the micellae is greater than in the outside solution due to a greater concentration of protein in the micellae. This brings about a further swelling of the micellae until a Donnan equilibrium is established in the ion distribution accompanied by an equilibrium in the osmotic pressure. Through the application of the theory developed here it was possible actually to calculate the osmotic pressure difference between the inside of the micellae and the outside solution which was brought about by the difference in the ion distribution. 6. According to the same theory the effect of pH on viscosity of gelatin should diminish with increase in concentration of gelatin, since the difference in the concentration of the protein inside and outside of the micellae also decreases. This was confirmed experimentally. At concentrations above 8 gm. per 100 gm. of H(2)O there is very little difference in the viscosity of gelatin of various pH as compared with that of isoelectric gelatin. PMID- 19872363 TI - STUDIES ON ENZYME ACTION : XLV. LIPASE ACTIONS OF THE WHOLE TROUT AT DIFFERENT AGES. AB - The ester-hydrolyzing or lipase actions of extracts and whole solids of trout eggs and whole trout of different ages were tested on ten simple esters by the method described in previous papers. Differences in solubility of the enzyme materials of the eggs were found. The "pictures" of the relative enzyme actions changed from a type found with immature eggs to a type which became constant for the fish after they had eaten for 2 weeks. After this, the type did not change up to the age of 4 to 5 years (the oldest trout studied). The absolute ester hydrolyzing actions of the materials were also presented and discussed. PMID- 19872364 TI - STUDIES ON ENZYME ACTION : XLVI. THE ESTER-HYDROLYZING ACTIONS OF WHOLE TROUT PREPARATIONS UNDER VARIOUS CONDITIONS. AB - The ester-hydrolyzing actions of trout extracts at different hydrogen ion concentrations were studied. It was pointed out that the behavior was similar to that found with various tissue and tumor materials and that similar relations hold. Glycerol solutions extracted somewhat larger amounts of active enzyme material from trout than did water and sodium chloride solutions, although the differences were not large. Evidence was presented for the existence of a so called "coenzyme." PMID- 19872365 TI - THE ANALYSIS OF THE DIVISION RATES OF CILIATES. AB - 1. Analysis of the division rates of Paramecium aurelia (mutant), Blepharisma undulans, and Histrio complanatus grown separately in pedigree isolation culture with the same culture medium, and in the same room at any given time, for a period of 3 years, discloses a secular trend and a seasonal rhythm for each organism. The seasonal rhythm is a yearly cycle with a maximum during July. 2. After removal of the effects of trend and seasonal rhythm, no correlation is found between the division rates of the several organisms. The distribution of the division rates is then one of chance order, except for large deviations known to be associated with changes in the culture technique. Each organism has a division rate varying independently of the others. 3. Consequently, seasonal rhythm alone has forced similar variations in the division rates of these three protozoans. The seasonal effect is gradually lost when the animals are raised for several years under laboratory conditions. Examination of the literature discloses other similar cases. 4. It is clear that unless all of the conditions of experiment are kept constant, one must analyze all protozoan division rate data in some such manner as that here presented before any conclusions may be drawn as to the existence of "cycles" or "rhythms." PMID- 19872366 TI - STUDIES ON THE AMOUNT OF LIGHT EMITTED BY MIXTURES OF CYPRIDINA LUCIFERIN AND LUCIFERASE. AB - 1. A photometric method was devised for measuring the intensities of light emitted per cc. of hiciferin solution and calculating the amount of light emitted per gm. of dried Cypridina powder. A total of 128 runs was made and the data are incorporated in this report. 2. The maximum amount of light emitted from 1 gm. of powder under the experimental conditions was 0.655 lumens. Different samples of powder vary greatly in amount of light production. 3. When the concentration of substrate is doubled, nearly twice as much light is emitted, or an average ratio 2C/C of 1.86. Calculations of total light emissions per gm. of powder at different concentrations indicate that slightly more light is produced from the smaller concentrations. The maximum amount of light was produced by the solutions made with neutral sea water and averaged 0.445 lumens. The least light was obtained from solutions in distilled water saturated with hydrogen. The technique allows too rapid spontaneous oxidation prior to the saturation with hydrogen. The maximum amount of light from such experiments was only 0.077 lumens. Acid sea water solutions subsequently neutralized gave an average maximum of 0.386 lumens per gm. of powder per second. 4. When the concentration of enzyme is doubled, approximately the same amount of light is produced by both concentrations, although the stronger concentrations are slightly less effective than weaker ones. This undoubtedly is due to the colloidal nature of the enzyme and is a function of surface rather than of mass. In dilute solutions greater dispersion probably allows for greater adsorption to the surface of the enzyme. The average maximum amount of light produced in the series of enzyme experiments is of the magnitude 0.56 lumens per gm. of powder. PMID- 19872368 TI - THE KINETICS OF OSMOSIS. AB - It is shown that by combining the osmotic pressure and rate of diffusion laws an equation can be derived for the kinetics of osmosis. The equation has been found to agree with experiments on the rate of osmosis for egg albumin and gelatin solutions with collodion membranes. PMID- 19872367 TI - ON THE QUANTA OF LIGHT PRODUCED AND THE MOLECULES OF OXYGEN UTILIZED DURING CYPRIDINA LUMINESCENCE. AB - A study of the oxygen consumed per lumen of luminescence during oxidation of Cypridina luciferin in presence of luciferase, gives 11.4 x 10(-5) gm. oxygen per lumen or 88 molecules per quantum of lambda = 0.48micro, the maximum in the Cypridina luminescence spectrum. For reasons given in the text, the actual value is probably somewhat less than this, perhaps of the order of 6.48 x 10(-5) gm. per lumen or 50 molecules of oxygen and 100 molecules of luciferin per quantum. It is quite certain that more than 1 molecule per quantum must react. On the basis of a reaction of the type: luciferin + 1/2 O(2) = oxyluciferin + H(2)O + 54 Cal., it is calculated that the total efficiency of the luminescent process, energy in luminescence/heat of reaction, is about 1 per cent; and that a luciferin solution containing 4 per cent of dried Cypridina material should rise in temperature about 0.001 degrees C. during luminescence, and contain luciferin in approximately 0.00002 molecular concentration. PMID- 19872369 TI - THE SWELLING OF ISOELECTRIC GELATIN IN WATER : I. EQUILIBRIUM CONDITIONS. AB - The swelling of isoelectric gelatin in water has been found to be in agreement with the following assumptions. Gelatin consists of a network of insoluble material containing a solution of a more soluble substance. Water therefore enters owing to the osmotic pressure of the soluble material and thereby puts the network under elastic strain. The process continues until the elastic force is equal to the osmotic pressure. If the temperature is raised or the blocks of gelatin remain swollen over a period of time, the network loses its elasticity and more water enters. In large blocks this secondary swelling overlaps the initial process and so no maximum can be observed. The swelling of small blocks or films of isoelectric gelatin containing from .14 to .4 gm. of dry gelatin per gm. of water is defined by the equation See PDF for Equation in which K(e) = the bulk modulus See PDF for Equation. V(e) = gm. water per gm. gelatin at equilibrium; V(f) = gm. water per gm. gelatin when the gelatin solidified. PMID- 19872370 TI - THE SWELLING OF ISOELECTRIC GELATIN IN WATER : II. KINETICS. AB - It has been assumed that gelatin consists of a network of an insoluble material enclosing a solution of a more soluble material. The swelling of gelatin is therefore primarily an osmotic phenomena in that the water tends to diffuse in owing to the osmotic pressure of the soluble material. This osmotic pressure is opposed by the elasticity of the insoluble constituent, and equilibrium results when these two pressures are equal. The rate of the entrance of water should then obey Poiseuille's law, provided the variable terms are expressed as functions of the volume. Equations have been derived in this way which agree quite well with the experimental curves and which predict the proper relation between the size and shape of the block and the rate of swelling. They lead to a value for the rate of flow of water through gelatin which has been checked by direct measurement. The mechanism assumed predicts that at a higher temperature and under conditions such that the water has to pass through collodion before reaching the gelatin, the experiment should follow the same course as that of osmosis discussed previously. This was also found to be the case. The slow secondary increase in swelling is ascribed to fatigue of the elastic properties of the gelatin. The rate of this secondary swelling should therefore be independent of the size of the block, in contrast to the rate of primary swelling which is inversely proportional to the size. It can further be shown that this secondary swelling should be proportional to the square root of the time, and also that with large blocks at higher temperatures the entire swelling should be of this secondary type. These predictions have also been found to be true. PMID- 19872371 TI - ON THE NATURE OF THE DYE PENETRATING THE VACUOLE OF VALONIA FROM SOLUTIONS OF METHYLENE BLUE. AB - When uninjured cells of Valonia are placed in methylene blue dissolved in sea water it is found, after 1 to 3 hours, that at pH 5.5 practically no dye penetrates, while at pH 9.5 more enters the vacuole. As the cells become injured more dye enters at pH 5.5, as well as at pH 9.5. No dye in reduced form is found in the sap of uninjured cells exposed from 1 to 3 hours to methylene blue in sea water at both pH values. When uninjured cells are placed in azure B solution, the rate of penetration of dye into the vacuole is found to increase with the rise in the pH value of the external dye solution. The partition coefficient of the dye between chloroform and sea water is higher at pH 9.5 than at pH 5.5 with both methylene blue and azure B. The color of the dye in chloroform absorbed from methylene blue or from azure B in sea water at pH 5.5 is blue, while it is reddish purple when absorbed from methylene blue and azure B at pH 9.5. Dry salt of methylene blue and azure B dissolved in chloroform appears blue. It is shown that chiefly azure B in form of free base is absorbed by chloroform from methylene blue or azure B dissolved in sea water at pH 9.5, but possibly a mixture of methylene blue and azure B in form of salt is absorbed from methylene blue at pH 5.5, and azure B in form of salt is absorbed from azure B in sea water at pH 5.5. Spectrophotometric analysis of the dye shows the following facts. 1. The dye which is absorbed by the cell wall from methylene blue solution is found to be chiefly methylene blue. 2. The dye which has penetrated from methylene blue solution into the vacuole of uninjured cells is found to be azure B or trimethyl thionine, a small amount of which may be present in a solution of methylene blue especially at a high pH value. 3. The dye which has penetrated from methylene blue solution into the vacuole of injured cells is either methylene blue or a mixture of methylene blue and azure B. 4. The dye which is absorbed by chloroform from methylene blue dissolved in sea water is also found to be azure B, when the pH value of the sea water is at 9.5, but it consists of azure B and to a less extent of methylene blue when the pH value is at 5.5. 5. Methylene blue employed for these experiments, when dissolved in sea water, in sap of Valonia, or in artificial sap, gives absorption maxima characteristic of methylene blue. Azure B found in the sap collected from the vacuole cannot be due to the transformation of methylene blue into this dye after methylene blue has penetrated into the vacuole from the external solution because no such transformation detectable by this method is found to take place within 3 hours after dissolving methylene blue in the sap of Valonia. These experiments indicate that the penetration of dye into the vacuole from methylene blue solution represents a diffusion of azure B in the form of free base. This result agrees with the theory that a basic dye penetrates the vacuole of living cells chiefly in the form of free base and only very slightly in the form of salt. But as soon as the cells are injured the methylene blue (in form of salt) enters the vacuole. It is suggested that these experiments do not show that methylene blue does not enter the protoplasm, but they point out the danger of basing any theoretical conclusion as to permeability on oxidation-reduction potential of living cells from experiments made or the penetration of dye from methylene blue solution into the vacuole, without determining the nature of the dye inside and outside the cell. PMID- 19872372 TI - UDDER SIZE IN RELATION TO MILK SECRETION. AB - The results herein presented furnish exact critical evidence for the conclusion that the most of the milk is present as such in the udder of dairy cattle at the time of milking. The amount of milk which may be secreted during milking cannot, on the basis of these results, be over 20 per cent of the milk yield of the cow. The results show clearly that the size of the udder measures closely the amount of milk which the cow is able to secrete. The results indicate that about 1/5 of a pound of secreting tissue is necessary for the secretion of a pound of milk during a period of 15 hours. The weight of the udder during the period that the cow is dry appears to be between 6 and 8 pounds. PMID- 19872373 TI - THE EFFECT OF TEMPERATURE UPON SOME OF THE PROPERTIES OF CASEIN. AB - 1. The investigations dealing with the properties of casein as an acid were reviewed. 2. The solubility of uncombined casein in water was measured at 5 degrees C. and found to be 0.70+/-0.1 mg. of N per 100 gm. of water. 3. Robertson's solubility measurements of casein in bases at various temperatures were recalculated and found to agree well with more recent measurements. 4. By combining the observations of several investigators, as well as the author's measurements of the solubility of casein, in base, at various temperatures, the following conclusions were reached: (a) The solubility of casein in base is affected by the temperature in a discontinuous manner. (b) There exist two ranges of temperature, one, extending from about 21 degrees to 37 degrees C. and the other from about 60 degrees to 85 degrees C. where the solubility of casein in base is practically independent of temperature. (c) From 37 degrees to 60 degrees the equivalent combining weight of casein rises from the value 2100 to about 3700 gm. 5. By comparing the values of base bound by 1 gm. of casein at the two temperature ranges with a constant, the value of base necessary to saturate the same amount of casein, it was found that the latter value is a common multiple of the former values, indicating the stoichiometric nature of the effect of temperature. PMID- 19872374 TI - THE EFFECT OF RENNIN UPON CASEIN : I. THE SOLUBILITY OF PARACASEIN IN SODIUM HYDROXIDE. AB - 1. The preparation and purification of paracasein was described and certain criteria for the absence of free enzyme provided for. 2. The solubility of purified paracasein in water at low temperature was studied, and found practically identical with the solubility of casein. 3. The capacity of paracasein to bind base was investigated by means of its solubility in NaOH at 5 degrees and at 23 degrees +/- 2 degrees C., and found to be distinctly different from that of casein. 4. At these two temperature levels paracasein had a 1.5 greater capacity to bind base than casein. The equivalent combining weights of paracasein and casein were found to stand each to the other, apapproximately, as 2 to 3. 5. This relationship suggested that the temperature coefficients of the solubility of paracasein and casein in NaOH are identical. 6. This evidence indicates that paracasein is a modification of casein, distinguishable by physicochemical means. PMID- 19872375 TI - ULTRA-VIOLET ABSORPTION SPECTRA OF CERTAIN PHYSIOLOGICAL FLUIDS. PMID- 19872376 TI - THE RATE OF KILLING OF CLADOCERANS AT HIGHER TEMPERATURES. AB - In spite of obvious possible sources of disturbance, the "velocity of killing" of organisms at supranormal temperatures, properly determined, tends to adhere to the Arrhenius equation for relation to temperature. Over certain ranges of temperature the relationship between log velocity of killing and 1/T degrees abs. is linear. Interpreted as due to the thermal denaturing of protein, it is possible that differences between the temperature characteristics for the killing process in closely related forms may be suggestive in regard to the mechanism of the denaturing. The temperature limits within which the linear relationships appear may be classed among those temperature levels which are critical temperatures for protoplasmic organization. PMID- 19872377 TI - ON THE NATURE OF THE EQUATION FOR GROWTH PROCESSES. AB - An analysis of the growth curves of a cladoceran for one adult instar at each of two temperatures is made by comparing the apparent gains or losses in time when the animals are transferred from one of these temperatures to the other during the course of the developmental period. Since the curves for the two temperatures when brought together at their end-point do not coincide, the equation used to describe growth must have at least two velocity constants unequally affected by changes in temperature. PMID- 19872378 TI - KINETICS OF THE SWELLING OF CELLS AND TISSUES. AB - The rate of swelling of Arbacia eggs in dilute sea water, studied by Lillie and by Lucke and McCutcheon, may be expressed by the formulae derived for the rate of increase in volume of a solution enclosed in a collodion sac. The rate of swelling of slices of carrot in distilled water, measured by Stiles and Jorgensen, may be expressed by the equation derived previously for the swelling of similarly shaped blocks of gelatin. PMID- 19872379 TI - THE PRENATAL GROWTH OF THE MOUSE. AB - 1. The general course of prenatal growth in the mouse, the guinea pig, and the chick can be expressed by straight line relations between the logarithms of the weight and age only when age is counted from the beginning of the embryo proper. 2. This is interpreted as showing that the manner of growth before the beginning of the embryo proper is essentially different from that after this time. 3. The velocity constants for the animals mentioned are similar; the major differences in their curves depend on the amount of tissue involved in the first organization of the embryo proper and in the length of prenatal life. 4. Growth of different animals may be compared more accurately if, instead of either birth age or conception age, embryo age is used. PMID- 19872380 TI - ORIENTATION IN COMPOUND FIELDS OF EXCITATION; PHOTIC ADAPTATION IN PHOTOTROPISM. AB - During upward geotropic orientation upon a vertical plate the slug Agriolimax creeps vertically, in darkness. Horizontal light from one side produces orientation of dark-adapted slugs away from the vertical path, through an angle (beta). The magnitude of this angle is a function of the light intensity and of time. The moderately rapid course of light adaptation is followed by measurements of beta at fixed intervals. Simple assumptions as to the nature of the orienting forces lead to the conclusion that the logarithm of the tangent of beta should decrease linearly with time, and that the rate of the decrease should vary directly with the logarithm of the light intensity. Both expectations are adequately realized. Certain implications of these results for behavior analysis are pointed out. PMID- 19872381 TI - ON THE TITRATION OF BACTERIOPHAGE AND THE PARTICULATE HYPOTHESIS. AB - 1. The theory of the serial dilution method of titration of bacterio-phage has been worked out on the basis of the simple particulate hypothesis. 2. It has been shown that, if the dilution constant is .1, only about 60 per cent of parallel runs on the same solution should give the same end-point, the average being taken over a great number of titrations of each of a great variety of solutions. 3. The discrepancy between this figure, 60 per cent, and Dr. Bronfenbrenner's estimate, 85 per cent, is considerable. 4. Inasmuch as the particulate hypothesis is well founded, no explanation of the discrepancy is suggested. PMID- 19872382 TI - SOME ASPECTS OF BIOELECTRICAL PHENOMENA. AB - It is pointed out that there are great advantages in using single cells instead of tissues in the study of bioelectrical phenomena. Certain bioelectrical phenomena are discussed in relation to the structure of protoplasm. Under certain circumstances measurements of potential differences may enable us to determine what ions enter the protoplasm. Under suitable conditions we are able to ascertain the potential differences across the protoplasm at single points, instead of being obliged merely to measure the differences between two points. PMID- 19872383 TI - COMBINATION OF GELATIN WITH SOME ORGANIC BASES. PMID- 19872384 TI - THE EFFECT OF ACETATE BUFFER MIXTURES, ACETIC ACID, AND SODIUM ACETATE, ON THE PROTOPLASM, AS INFLUENCING THE RATE OF PENETRATION OF CRESYL BLUE INTO THE VACUOLE OF NITELLA. AB - When living cells of Nitella are exposed to a solution of sodium acetate and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, a decrease in the rate of penetration of dye is found, without any change in the pH value of the sap. It is assumed that this inhibiting effect is caused by the action of sodium on the protoplasm. This effect is not manifest if the dye solution is made up with phosphate buffer mixture at pH 7.85. It is assumed that this is due to the presence of a greater concentration of base cations in the phosphate buffer mixture. In the case of cells previously exposed to solutions of acetic acid the rate of penetration of dye decreases with the lowering of the pH value of the sap. This inhibiting effect is assumed to be due chiefly to the action of acetic acid on the protoplasm, provided the pH value of the external acetic acid is not so low as to involve an inhibiting effect on the protoplasm by hydrogen ions as well. It is assumed that the acetic acid either has a specific effect on the protoplasm or enters as undissociated molecules and by subsequent dissociation lowers the pH value of the protoplasm. With acetate buffer mixture the inhibiting effect is due to the action of sodium and acetic acid on the protoplasm. The inhibiting effect of acetic acid and acetate buffer mixture is manifested whether the dye solution is made up with borate or phosphate buffer mixture at pH 7.85. It is assumed that acetic acid in the vacuole serves as a reservoir so that during the experiment the inhibiting effect still persists. PMID- 19872385 TI - COUNTERACTION OF THE INHIBITING EFFECTS OF VARIOUS SUBSTANCES ON NITELLA. AB - When living cells of Nitella are first exposed to (1) phosphate buffer mixture, or (2) phosphoric acid, or (3) hydrochloric acid, or (4) sodium chloride, or (5) sodium borate, and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, the rate of penetration of the dye into the vacuole is decreased as compared with the rate in the case of cells transferred directly from tap water to the same dye solution. When cells exposed to any one of these solutions are placed in the dye solution made up with phosphate buffer solution at pH 7.85, the rate of penetration of dye into the vacuole is the same as the rate in the case of cells transferred from the tap water to the same dye solution. It is probable that this removal of the inhibiting effect is due primarily to the presence of certain concentration of sodium and potassium ions in the phosphate buffer solution. If a sufficient concentration of sodium ions is added to the dye made up with a borate buffer mixture the inhibiting effect is removed just as it is in the case of the dye made up with the phosphate buffer mixture. The inhibiting effect of some of these substances is found to be removed by the dye containing a sufficient concentration of bivalent cations, or by washing the cells with salts of bivalent cations. The inhibiting effect and its removal are discussed from a theoretical standpoint. PMID- 19872386 TI - GEOTROPIC ORIENTATION OF YOUNG MICE. AB - The geotropic orientation of young mice, on a plane at angles between 20 degrees and 50 degrees to the horizontal, obeys the equations previously found for young rats by Crozier and Pincus (1926-27). When the individuals tested in such experiments are not of the utmost uniformity, the variability of the measured orientations is increased. PMID- 19872387 TI - STUDIES ON THE PERMEABILITY OF MEMBRANES : IV. VARIATIONS OF TRANSFER NUMBERS WITH THE DRIED COLLODION MEMBRANE PRODUCED BY THE ELECTRIC CURRENT. AB - The transfer number of Cl in a KCl solution within the pores of a dried collodion membrane is always lower than 0.5. It depends on the concentration of the solution and decreases in general with decreasing concentration. However, the transfer number for any given KCl concentration has the significance of a definite and constant figure only when an infinitely small amount of coulombs is allowed to pass through the system. For finite durations of electric transfer experiments a polarization effect will always change the original transfer number. This polarization consists in an accumulation of the salt at the one boundary and a diminution at the other boundary of the membrane. Again, as the transfer number strongly depends on concentration, this change in concentration will bring about in its turn a gradual change in the transfer number too. It is shown under what conditions the transfer numbers for the anion as obtained by electic transfer experiments are higher or lower than the ones expected without polarization effect. Thus, by changing the character and magnitude of the force driving the ions across the membranes, and according to the history of previous treatment of the membrane, the whole character of what we may call the specific permeablity for ions of the membrane may be varied without any substantial change of the membrane itself concerning its structure, its chemical composition, or its pore size. Contemplation of the results obtained in this series of experiments in the light of the theoretical considerations just outlined has impressed us with the fallacy of speaking of the definite permeability of any type of membrane for electrolytes. The behavior of the membrane toward the passage of electrolytes depends on a variety of conditions. It may be recalled that different investigators have reported widely varying results concerning the permeability of certain physiological membranes for electrolytes. Such experiments as have been described in this paper may lead to an understanding of some of the factors responsible for such variations. We are aware that the collodion membrane in its simplicity is scarcely comparable to the extremely complicated biological membranes. Nevertheless any attempts to understand better the behavior of biological membranes may wisely begin with a study of the simplest prototypes. PMID- 19872388 TI - THE EFFECTS OF POLARIZATION UPON THE STEEL WIRE-NITRIC ACID MODEL OF NERVE ACTIVITY. AB - The active process in a short length of steel wire passivated by 65 per cent nitric acid has been observed under the influence of a polarizing current, and the form of the potential recorded by the cathode ray oscillograph. In the passive wire, 80 per cent of the total potential drop takes place at the anode, 20 per cent at the cathode. The change from active to passive states, as measured by the potential change, is very abrupt compared to the duration of activity and the potential curve at a point on the wire is probably almost rectangular. The duration of the refractory state is decreased at the anode and increased at the cathode, as in nerve. This fact is against the idea that reactivity after passivation results from a partial reduction of an oxide layer. Soft iron wire passivated by anodal polarization repassivates after activation in acid of a dilution that fails to passivate it initially. It soon becomes rhythmic with a very short refractory phase, and then reacts continuously. Such a wire exhibits a very sharp alternation between a dark brown oxide coat during activity, and a bright clean surface during passivation. A passive steel wire in nitric acid shows many of the characteristics of an inert electrode such as platinum, and it may be inferred that, superposed upon the primary passivation potential, there exists an electrode or oxidation-reduction potential equilibrium between the effects of the various constituents of the solution. It is suggested that the phenomena of nerve-like reactivity in this system may involve an alternation between two protective coatings of the steel wire. During activity, the surface becomes mechanically coated with a brown oxide. If this coating does not adhere, due to gas convection or to rapid solution of the oxide, passivation does not result. Under sufficiently intense oxidizing conditions, a second oxide coat may form in the interstices of the first, and cover the surface as the first coating dissolves off. This furnishes the electrochemical protection of passivation, which is followed by the gradual attainment of electrode equilibrium with the solution. PMID- 19872389 TI - THE RESPIRATORY QUOTIENT OF FROG NERVE DURING STIMULATION. AB - 1. By means of a differential volumeter the increased oxygen consumption and the increased carbon dioxide output of frog nerve during and after stimulation have been observed. 2. Measurements of the R.Q. of nerve by this method are complicated by the retention of carbon dioxide. Attempts were made to avoid this (a) by studying the nerves at high CO(2) tensions to make the retention small and (b) by calculating the amount of CO(2) retained from the carbon dioxide dissociation curve of nerve and applying this value as a correction. 3. The results of both those methods when averaged together give an R.Q. of the excess metabolism of 1.19 and an R.Q. of the resting nerve of 0.97. 4. Observations on the time course of the gas exchange during stimulation indicate a delay in the appearance of the extra carbon dioxide output relative to the oxygen intake. 5. Very similar time curves can be calculated from the diffusion coefficients and the solubilities of the oxygen and the carbon dioxide. PMID- 19872390 TI - DISSIMILARITY OF INNER AND OUTER PROTOPLASMIC SURFACES IN VALONIA. AB - The protoplasm of Valonia macrophysa forms a delicate layer, only a few microns in thickness, which contains numerous chloroplasts and nuclei. The outer surface is in contact with the cell wall, the inner with the vacuolar sap. As far as microscopic observation goes, these two surfaces seem alike; but measurements of potential difference indicate that they are decidedly different. We find that the chain sap | protoplasm | sap gives about 14.5 millivolts, the inner surface being positive to the outer. In order to explain this we may assume that the protoplasm consists of layers, the outer surface, X, differing from the inner surface, Y, and from the body of the protoplasm, W. We should then have the unsymmetrical chain sap | X | W | Y | sap which could produce an electromotive force. If the two surfaces of such a very thin layer of protoplasm can be different, it is of fundamental significance for the theory of the nature of living matter. PMID- 19872391 TI - ACID PENETRATION INTO LIVING TISSUES. AB - The threshold concentrations for sourness of nine acids have been determined with an accuracy of about 8 per cent, and the H(+) ion concentration of these acids measured. Calculations have been made of the relative concentration gradients of the undissociated acid across the cell membrane for a series of acids having equal sourness and also for a series of acids having equal penetration velocity as determined from experiments by Crozier on Chromodoris and on Allolobophora. For solutions of equal pH a high degree of sourness has been found to be associated with a high penetration velocity of the undissociated acid or of the anion. A comparison of these gradients with the results of adsorption experiments on charcoal indicates that the acids are taken into the tissues by an adsorption process. Polar groups such as OH and Cl and Br are found to have a very marked effect in reducing the ability of organic acids to penetrate living tissues. The important role of optical activity of the acids in determining their physiological action has been noted. PMID- 19872392 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : V. THE ANTAGONISM OF CATIONS IN THEIR ACTIONS ON THE PROTOPLASM OF AMOEBA DUBIA. AB - I. The Plasmalemma. 1. On the plasmalemma of amebae CaCl(2) antagonizes the toxic action of LiCl better than it does NaCl, and still better than it does KCl. MgCl(2) antagonizes the toxic action of NaCl better than it does LiCl and still better than it does KCl. 2. CaCl(2) antagonizes the toxic action of LiCl and of KCl better than does MgCl(2): MgCl(2) antagonizes NaCl better than does CaCl(2). II. The Internal Protoplasm. 3. The antagonizing efficiency of CaCl(2) and of MgCl(2) are highest against the toxic action of KCl on the internal protoplasm, less against that of NaCl, and least against that of LiCl. 4. CaCl(2) antagonizes the toxic action of LiCl better than does MgCl(2): MgCl(2) antagonizes the toxic action of NaCl and of KCl better than does CaCl(2). 5. LiCl antagonizes the toxic action of MgCl(2) on the internal protoplasm more effectively than do NaCl or KCl, which have an equal antagonizing effect on the MgCl(2) action. III. The Nature of Antagonism. 6. When the concentration of an antagonizing salt is increased to a toxic value, it acts synergistically with a toxic salt. 7. No case was found in which a potentially antagonistic salt abolishes the toxic action of a salt unless it is present at the site (surface or interior) of toxic action. 8. Antagonistic actions of the salts used in these experiments are of differing effectiveness on the internal protoplasm and on the surface membrane. PMID- 19872393 TI - THE PERMEABILITY OF THIN DRY COLLODION MEMBRANES. AB - Dry thin collodion membranes have been prepared which are permeable to water, ammonia, weak acids of low molecular weight, HCl gas, O(2), CO(2), and H(2)S, but are impermeable to strong electrolytes and substances of high molecular weight. The permeability to gases does not depend on the density, so that the gases do not pass through pores in the membrane. PMID- 19872394 TI - THE EFFECT OF RENNIN UPON CASEIN : II. FURTHER CONSIDERATION OF THE PROPERTIES OF PARACASEIN. AB - The properties of the paracasein and casein preparations studied are compared in Table VI. See PDF for Structure I. Casein retains its characteristic solubility in NaOH: (1) after being exposed to a high degree of alkalinity during its preparation, (2) when recovered from partially hydrolyzed solutions in NaOH, and (3) after being kept for a prolonged time at the isoelectric point at 5 degrees C. II. It follows from I, that: (1) paracasein is not identical to casein modified by an excess of alkali, and that (2) this protein was not produced from casein by a partial hydrolysis of the latter in presence of NaOH. PMID- 19872395 TI - THE RELATION BETWEEN VISUAL ACUITY AND ILLUMINATION. AB - 1. Visual acuity varies in a definite manner with the illumination. At low intensities visual acuity increases slowly in proportion to log I; at higher intensities it increases nearly ten times more rapidly in relation to log I; at the highest illuminations it remains constant regardless of the changes in log I. 2. These variations in visual acuity measure the variations in the resolving power of the retina. The retina is a surface composed of discrete rods and cones. Therefore its resolving power depends on the number of elements present in a unit area. The changes in visual acuity then presuppose that the number of elements in the retina is variable. This cannot be true anatomically; therefore it must be assumed functionally. 3. To explain on such a basis the variations of visual acuity, it is postulated that the thresholds of the cones and of the rods are distributed in relation to the illumination in a statistical manner similar to that of other populations. In addition the rods as a whole have thresholds lower than the cones. Then at low intensities the increase in visual acuity depends on the augmentation of the functional rod population which accompanies intensity increase; and at higher intensities the increase in visual acuity depends on the augmentation of the functional cone population. The number of cones per unit foveal area is much greater than the number of rods per unit peripheral area, which accounts for the relative rates of increase of rod and cone visual acuity with intensity. At the highest illuminations all the cones are functional and no increase in visual acuity is possible. 4. If this division into rod visual acuity and cone visual acuity is correct, a completely color-blind person should have only rod visual acuity. It is shown by a study of the data of two such individuals that this is true. 5. The rod and cone threshold distribution has been presented as a purely statistical assumption. It can be shown, however, that it is really a necessary consequence of a photochemical system which has already been used to describe other properties of vision. This system consists of a photosensitive material in reversible relation with its precursors which are its products of decomposition as well. 6. On the basis of these and other data it is shown that a minimal retinal area in the fovea, which can mediate all the steps in such functions as visual acuity, intensity discrimination, and color vision, contains about 540 cones. Certain suggestions with regard to a quantitative mechanism for color vision are then correlated with these findings, and are shown to be in harmony with accurately known phenomena in related fields of physiology. PMID- 19872396 TI - THE MEASUREMENT OF GALVANOTROPIC EXCITATION. AB - The expression of galvanotropic excitation in energy units is obtained by the measurement of the current densities required to balance phototropic excitation (or reciprocally). With the triclad Leptoplana preliminary measurements show that the current is proportional to the logarithm of the light intensity. PMID- 19872397 TI - ON THE PLACE OF PHOTIC ADAPTATION. AB - The progress of photic adaptation of Agriolimax, when studied by the method of compounding phototropic and geotropic vectors, is shown to be uninfluenced by the concurrent gravitational excitation. Direct proof is thus obtained that the adaptation to light, manifest in its steadily decreasing effectiveness as a stimulus during the course of exposure, is not due to any central nervous adjustment simulating "learning," but is due to photochemical changes in the receptors. PMID- 19872398 TI - PHOTOTROPISM OF DIXIPPUS MOROSUS. AB - 1. Local differences in the effects of stimulation of parts of the eye by light are expressed in Dixippus morosus by differential circus movements. 2. The angle of inclination of the body axis toward one source of light when the animal is on a vertical plane with light from one side is inversely proportional to the logarithm of the intensity of the light. PMID- 19872399 TI - THE SURFACE TENSION OF PHYSIOLOGICAL SOLUTIONS : DIFFICULTIES OF MEASUREMENT AND INTERPRETATION. AB - 1. Data are given to show that surface tension values obtained by the ring method cannot be considered reliable when absolute values are desired. 2. Data are given to show that, in the case of solutions of semicolloids, surface tension values obtained for a definite period of time following the formation of a new interface cannot always be consistently reproduced by the ring method. 3. It is shown that in the case of solutions of semicolloids, equilibrium values are not readily obtained and should generally not be assumed to have been reached after any definite period of time. 4. The general difficulty of interpreting surface tension values obtained in the case of solutions of semicolloids, by any method, is emphasized. PMID- 19872400 TI - THE DECOMPOSITION OF HYDROGEN PEROXIDE BY LIVER CATALASE. AB - 1. The velocity of decomposition of hydrogen peroxide by catalase as a function of (a) concentration of catalase, (b) concentration of hydrogen peroxide, (c) hydrogen ion concentration, (d) temperature has been studied in an attempt to correlate these variables as far as possible. It is concluded that the reaction involves primarily adsorption of hydrogen peroxide at the catalase surface. 2. The decomposition of hydrogen peroxide by catalase is regarded as involving two reactions, namely, the catalytic decomposition of hydrogen peroxide, which is a maximum at the optimum pH 6.8 to 7.0, and the "induced inactivation" of catalase by the "nascent" oxygen produced by the hydrogen peroxide and still adhering to the catalase surface. This differs from the more generally accepted view, namely that the induced inactivation is due to the H(2)O(2) itself. On the basis of the above view, a new interpretation is given to the equation of Yamasaki and the connection between the equations of Yamasaki and of Northrop is pointed out. It is shown that the velocity of induced inactivation is a minimum at the pH which is optimal for the decomposition of hydrogen peroxide. 3. The critical increment of the catalytic decomposition of hydrogen peroxide by catalase is of the order 3000 calories. The critical increment of induced inactivation is low in dilute hydrogen peroxide solutions but increases to a value of 30,000 calories in concentrated solutions of peroxide. PMID- 19872401 TI - THE ACTION OF POTASSIUM CYANIDE AND POTASSIUM FERRICYANIDE ON CERTAIN RESPIRATORY PIGMENTS. AB - The oxygen in hemoglobin is liberated by K(3)Fe(CN)(6) and not by KCN, that in hemocyanin by KCN and not by K(3)Fe(CN)(6), that in hemerythrin by both, and that in echinochrome by K(3)Fe(CN)(6) and not by KCN. The bearing of these results on the nature of the substances involved is discussed. PMID- 19872402 TI - TEMPERATURE CHARACTERISTICS FOR FREQUENCY OF RESPIRATORY MOVEMENTS IN YOUNG MAMMALS. AB - The internal temperature of 2 day old mice deviates by +0.01 degrees to +3.0 degrees C. from the environmental temperature over a range of 24 degrees . The undeveloped temperature control allows rhythmic activities in this mammalian material to be readily subjected to the analysis afforded by temperature characteristics, and thus makes possible some insight into the physicochemical events controlling vital processes in entire uninjured mammals. The thermal increments and critical temperatures obtained point to a similarity in the controlling system of reactions for both homothermic and poikilothermic organisms. For frequency of respiratory movements the increments 12,340 (19.6 degrees to 35.2 degrees C.); 28,340 or 36,500 (15.5 degrees to 19.6 degrees C.) are most frequently found (thirteen cases). Rarely micro = 8,450, 33,000, or 18,340 (two cases). The last increment is either associated with micro = 36,000 below 20 degrees , or extends unbroken throughout the whole range (one case). PMID- 19872403 TI - THE PHOSPHATE ION AND HYDROLYSIS BY PANCREATIC LIPASE. AB - The equation, (activity of enzyme) (pPO(4))(n) = K, has been investigated and has been shown to have only a limited application to the effect of the phosphate ion on the hydrolytic activity of pancreatic lipase. The deviations observed are ascribed to the effect of certain factors on the stability of the enzyme. PMID- 19872404 TI - THE GEOTROPIC REACTION OF RODLESS MICE IN LIGHT AND IN DARKNESS. AB - "Black-short ears-kinky tail-rodless" mice, controlled by "pink eyed-dilute brown" mice, were tested on an inclined plane in order to determine if they are photically sensitive, and, if so, to get a quantitative expression for their visual receptivity. Rodless and control animals were tested in the dark to obtain an expression for normal geotropic orientation. Light was then introduced to modify these reactions if possible. Under light, the controls failed to orient, whereas the rodless gave reactions almost identical with those in the dark. This test has failed in this experiment to suggest sight in the rodless mouse. PMID- 19872405 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XIII. THE TEMPERATURE CHARACTERISTIC FOR THE CONTRACTION RATE OF THE WHOLE HEART. AB - The relation of heart rate frequencies to temperature in intact chicken embryos has been studied and the temperature characteristics calculated for each of a number of ages. These have been found to vary from 14,000 or better 12,000 micro for embryos 3 days old, to about 6,000 micro for others of 15 days. There appears to be a systematic change with time. If this inference is correct, important correlation with other properties of the pace-making function in the intact heart should become possible. PMID- 19872406 TI - THE DETERMINATION OF THE EQUIVALENT WEIGHT OF PROTEINS. AB - The magnitude of the correction in the fifth column of Table III may be open to some doubt, as are all corrections of such a character, and the significance of the above experiment in the author's mind lies not so much in the actual magnitude of the values given in the last column of this table as in their comparative magnitudes. For this reason the entire experiment reported was performed in a single session using the same gelatin solution, so that, whatever the magnitude of the correction, it would be the same in all cases. Actually the results in the case of the acid titrations are in fair agreement with those of Hitchcock (8). In the present experiment it is seen that, within the limits of experimental error, one gets the same value for the number of cc. of tenth normal acid bound by 1 gm. of gelatin whether one titrates with the acid or with the gelatin. In the case of the base there is a small difference, due probably to carbon dioxide, but this effect is in a direction opposite to that which one would expect on the assumption that it is due to appreciable adsorption. From this it is concluded that the binding due to adsorption in the case of gelatin is not significant compared to that due to chemical neutralization. The author realizes that gelatin is a poor choice for a basis of generalizations, and similar work is at present in progress on various other proteins. He does feel, however, that the conclusions of Hoffman and Gortner from their work on the prolamines may also be too widely generalized, and that, on the whole, the acid or alkali bound by adsorption in the case of proteins will not constitute the large majority of the total amounts bound, though certainly one will expect a certain amount of such binding in all cases. It also seems that before placing undue emphasis on the conclusions of these workers the possibilities of equivocal results due to specific technique should be considered. This technique consisted in introducing weighed amounts of dry protein into a definite volume of standard acid or base at the equilibrium temperature, in general, and, "after about 15 minutes, during which time the flask was shaken several times," determining the pH of the equilibrium solution. Is it possible that the actual speed of solution of the protean is such that, even though reproducible results are obtained using identical technique, actual equilibrium conditions are approached only when comparatively high concentrations of acid or alkali are employed, in which cases the solution velocity of the protein may he expected to be greater, other factors remaining constant? PMID- 19872407 TI - PROTOPLASMIC ASYMMETRY IN NITELLA AS SHOWN BY BIOELECTRIC MEASUREMENTS. AB - Using multinucleate cells of Nitella 2 or 3 inches in length it is possible to kill one end with chloroform without producing at the other any immediate alteration which can be detected by our present methods. When a spot in external contact with sap is killed its potential difference falls approximately to zero and it is therefore possible to measure the potential difference across the protoplasm at any desired point merely by leading off from that point to the one where the protoplasm has been killed. The results indicate that the inner and outer protoplasmic surfaces differ, for when both surfaces are in contact with the same solution (cell sap) there is an electromotive force of about 15.9 millivolts, the inner surface being positive to the outer (i.e. the positive current tends to flow from the inner surface through the electrometer to the outer surface). The situation resembles that in Valonia where the corresponding value (with Valonia sap applied to the outside) has been reported as about 14.5 millivolt (the inner surface being positive to the outer). It would seem appropriate to designate this as radial polarity. PMID- 19872408 TI - TEMPERATURE CHARACTERISTICS FOR THE GROWTH OF THE SPORANGIOPHORES OF PHYCOMYCES. AB - 1. With constant temperature and light intensity, the rate of elongation of a sporangiophore of Phycomyces is constant for many hours. 2. With constant light intensity, values of micro, the "critical thermal increment," have been computed for the elongation of different sporangiophores. These values group themselves closely about the modes 11,000, 16,000, 20,000, 26,000, and 33,000 calories. Sporangiophores from the same culture need not have similar increments. 3. The significance of these results for studies of growth is discussed. PMID- 19872409 TI - THE EFFECT OF TEMPERATURE ON THE MECHANICAL ACTIVITY OF THE GILLS OF THE OYSTER (OSTREA VIRGINICA Gm.). AB - 1. The method is described whereby the rate of flow produced by the gills of the oyster can be measured accurately. 2. The rate of doing work in maintaining a constant current along the glass tube can be expressed by the formula W = 2pilmicro S(2), where W = ergs/sec., l = length of the tube, micro = viscosity in poises, and S = speed at the axis of the tube. 3. The relationship between the rate of doing work and the temperature cannot be described by the equation of Arrhenius. 4. The optimum temperature for the mechanical activity of the gills lies between 25 degrees and 30 degrees C. Below 5 degrees no current is produced, though the cilia are beating. Ciliary motion stops entirely at the freezing temperature of sea water. 5. The factors responsible for the production of current are discussed. The study of the relations between the variability of the rate of flow and the temperature shows that between 15 degrees and 25 degrees C. the absolute variability remains constant and increases considerably above 25 degrees and below 15 degrees . The role of the coordination in the production of current is discussed, and the conclusion is reached that coordination is affected by the changes in temperature. PMID- 19872410 TI - ON THE RATE OF REACTION BETWEEN ENZYME AND SUBSTRATE. AB - 1. An equation of the form: See PDF for Equation in which v(t) is the time of flow of the mixture, v(w) the time of flow for water, v(f) the time of flow of the mixture when proteolysis is complete, v(o) the time of flow at the beginning of the experiment, t the time of observation, and r a constant, has been found to describe accurately the course of change of viscosity in a mixture of gelatin and pancreatin. 2. An equation of the same general form has been found to apply similarly to the reaction between other enzymes and other substrates. 3. The equation may be derived theoretically from assuming a bimolecular reaction between enzyme and substrate obeying the mass action law. PMID- 19872411 TI - THE RATE OF REDUCTION OF METHYLENE BLUE BY BACILLUS COLI. AB - This paper deals with the relation between substrate concentration and velocity in the case of the reduction of methylene blue and of the other oxidation reduction indicators of Clark by B. coli in the presence of succinic acid and glucose. This system is compared with starch and barley amylase. Reasons are given for considering the mechanism as an adsorption phenomenon. PMID- 19872412 TI - THE OXYGEN CONSUMPTION OF LUMINOUS BACTERIA. AB - Oxygen consumption of luminous bacteria determined by the Thunberg micro respirometer and by the time which elapses before the luminescence of an emulsion of luminous bacteria in sea water begins to dim, when over 99 per cent of the dissolved oxygen has been consumed, agree exactly. Average values for oxygen consumption at an average temperature of 21.5 degrees C. are 4.26 x 10(-11) mg. O(2) per bacterium; 2.5 x 10(4) mg. per kilo and 5.6 mg. O(2) per sq. m. of bacterial surface. The only correct comparison of the oxygen consumption of different organisms or tissues is in terms of oxygen used per unit weight with a sufficient oxygen tension so that oxygen consumption is independent of oxygen tension. Measurement of the oxygen concentration which just allows full luminescence, compared with a calculation of the oxygen concentration at the surface of a bacterial cell just necessary to allow the observed respiration throughout all parts of the cell, indicates that oxygen must diffuse into the bacterium much more slowly than through gelatin or connective tissue but not as slowly as through chitin. PMID- 19872413 TI - PREPARATION OF ELECTROLYTE-FREE GELATIN. PMID- 19872414 TI - COMBINATION OF SALTS AND PROTEINS : III. THE COMBINATION OF CuCl(2), MgCl(2), CaCl(2), AlCl(3), LaCl(3), KCl, AgNO(3)AND Na(2)SO(4)WITH GELATIN. AB - 1. The combination of Cu(++), Ca(++), Mg(++), Al(+++), La(+++), K(+), Ag(+), and Cl(-) with gelatin has been determined. 2. The equivalent combining value for copper is about 0.9 millimols per gm. of gelatin and is therefore the same as that of hydrogen. The value for copper with deaminized gelatin is about 0.4 to 0.5, again the same as that of hydrogen. The sum of the hydrogen and copper ions combined in the presence of an excess of either is 0.9 millimols showing that there is an equilibrium between the copper hydrogen and gelatin and that the copper and hydrogen are attached to the same group. 3. The equivalent combining value of La(+++) and Al(+++) is about 0.5 millimols per gm. of gelatin. This value is not significantly different with deaminized gelatin so that it is possible these salts combine only with groups not affected by deaminization. 4. No calcium is combined on the acid side of pH 3. The value rises rapidly from pH 3 to 4.7 and then remains constant. 5. No combination of K, Li, Na, NO(3) or SO(4) could be detected. 6. Cl combines less than the di- and trivalent metals so that the protein is positive in CaCl(2) but negative in KCl. PMID- 19872415 TI - THE VAPOR PRESSURE OF DOG'S BLOOD AT BODY TEMPERATURE. AB - The vapor pressures of dog's blood and blood plasma were determined at 37.5 degrees by the dynamic method and the osmotic pressures calculated from the experimental data. The vapor pressures calculated from experimentally determined freezing point data agreed, within the experimental error, with the values obtained from direct measurement. The vapor pressure lowering produced by the colloid constituents of the blood was also determined and found to be minimal compared to that of the other constituents. PMID- 19872416 TI - DRUG ACTION IN GALVANOTROPIC RESPONSES. AB - Under strychninization involving reversal of reciprocal inhibition of the circular and longitudinal muscles, planarians and earthworms show reversed, i.e., anodal, galvanotropic responses, which neither nicotine nor atropine induce (in planarians). The results strengthen the conclusion (Crozier, 1926-27) that in causing reversal of inhibition strychnine acts primarily on central synapses or on homologous elements. Like other arthropods, on the other hand, Asellus is little affected by strychnine; no reversal occurs. Caffeine and atropine are even less effective. Nicotine evokes abnormal posture and movements, perhaps reversed, but no alteration of anodal galvanotropism. PMID- 19872417 TI - THE ANTAGONISM BETWEEN ACETIC ACID AND THE CHLORIDES OF SODIUM, POTASSIUM, AND CALCIUM AS MANIFESTED IN DEVELOPING FUNDULUS EMBRYOS. AB - 1. Developing Fundulus embryos react in much the same way to mixtures of acetic acid in salt solutions whether their membranes are removed or not. It is therefore not necessary to assume any specific role for the membrane. 2. The primary toxic effect of acetic acid is to kill the surface of the embryo; heart stoppage is due to penetration of the acid after the surface has been injured. 3. The salt (NaCl, KCl, CaCl(2)) antagonizes the acetic acid by slowing or preventing the killing of the surface of the embryo. 4. If embryos are immersed in certain KCl-acetic acid mixtures, the surface killing effect of the acid is antagonized but at the same time the KCl penetrates and stops the heart in the manner which is characteristic of a KCl solution alone. PMID- 19872418 TI - POTENTIALLY UNLIMITED MULTIPLICATION OF YEAST WITH CONSTANT ENVIRONMENT, AND THE LIMITING OF GROWTH BY CHANGING ENVIRONMENT. AB - 1. The decrease in the rate of growth of a population of yeast cells, which results in the maintenance of an equilibrium crop level, is shown to be due to substances excreted into the culture medium by the growing cells. These toxic substances tend to destroy the young buds, because the percentage of budding cells is about the same at the time of most rapid growth and at the time of the growth equilibrium. 2. Alcohol is the product which primarily causes the decline of the growth rate. For the strain of yeast used, under the particular conditions of these experiments, a concentration of alcohol of about 1 mg. per cc. is associated with the beginning of the decrease of the growth rate. 3. The increasing acidity of the medium, due to CO(2), pyruvic acid, and other organic acids, is also a retarding influence. It is a secondary factor, however, as the greatest increase of the acidity of the medium occurs after pyruvic acid, probably a by-product of alcoholic fermentation, appears. 4. When the medium is maintained effectively constant, by preventing the accumulation of these toxic products, the yeast grows at a constant rate and the yeast growth is potentially unlimited. The limit of growth found in actual experiments is due only to the size of the test-tubes and to the relative efficiency of the method used in keeping the medium effectively constant. The necessity of maintaining a constant rate of growth in studies on the relations of yeasts to vitamines and other products is stressed. PMID- 19872419 TI - MICRURGICAL STUDIES IN CELL PHYSIOLOGY : VI. CALCIUM IONS IN LIVING PROTOPLASM. AB - The quiescence, rounding, sinking of the granules, and paling of the nucleus are similar to the effects seen after the injection of potassium and sodium chloride (11). Since the sodium salts of the anions were used, it might be inferred that the sodium is the active agent in the injected solutions. This is not entirely the case, however, for the effective concentrations of NaCl required are many times greater than those required in the case of the sodium salts of the calcium precipitating anions. The fact that practically the same effects can be obtained in both cases leads one to suspect that there is a relation between the results of an increase in sodium ions and a decrease in calcium ions. It has been shown that a M/416 CaCl(2) solution will antagonize a M/1 NaCl solution and even a more concentrated solution of KCl inside the ameba (12). Therefore the reduction in amount of calcium may leave a comparatively high concentration of unantagonized sodium and potassium. The fine, purplish red granules resulting from the injection of the alizarin are, no doubt, the insoluble calcium alizarinate. Recovery of an ameba from such an injection may be explained by the postulate that the free calcium ions in the living ameba are in equilibrium with a reserve supply of unionized calcium. The equilibrium is upset when the free calcium is removed by precipitation or by other means, and the system may possibly react in such a way as to counteract the effect of the change imposed. By mobilization of the calcium from a reserve supply the ameba can therefore gradually resume its normal activity. The time required for the recovery depends on the amount of alizarin injected. The diffuse red color which is seen immediately following the injection of alizarin probably represents that extra amount of dye which was not used in precipitating the immediately available calcium. Then, as the calcium is being liberated from the reserve, it is taken up by this surplus alizarin, resulting in a gradual loss of the diffuse coloration and an increase in the number of purplish See PDF for Structure red calcium alizarinate granules. Only when all of the injected dye has been precipitated can the mobilized calcium be used to carry on the normal physiological processes of the organism. The need of calcium to effect ameboid movement has been shown by Pantin (13) in a series of immersion experiments. This fact is quite suggestive, because the first effect of the injection of any of the calcium precipitants is absolute quiescence. Furthermore, there is no return to normal movement until the calcium apparently becomes available to the protoplasm. In support of the conception of a reserve supply of calcium is the presence of the large crystals which give a positive reaction with alizarin for calcium on the death of the ameba. Schewiakoff (14), from crystallographic studies, claims that they are calcium phosphate. The effect of the injection of the calcium-precipitating anions on the calcium of the protoplasm may be shown in another way. In determining the relative toxicity of these salts an arbitrarily standardized injection, about one-fourth of the volume of an ameba, was used. This was introduced because of the necessity to avoid effects due to variable amounts of the solvent, viz., water.. Thus the water effect was kept constant, and the variations in actual amount of salt injected were obtained by using a graded series of concentrations. Arranging the sodium salts of these anions in order of increasing toxicity in one column, and the in vitro solubility products of the corresponding calcium salts in another column, it is seen that as the toxicity increases, the solubility product decreases (Table 1). This fact strongly suggests that the toxicity depends on the ability of the salt to remove calcium ions from the protoplasm. The apparent deviation of the carbonate from the rule can be explained by the specific effect of 002 (10) which is always present from the hydrolysis of the carbonate. PMID- 19872420 TI - TEMPERATURE CHARACTERISTICS FOR PULSATION FREQUENCY IN GONIONEMUS. AB - The frequency of contraction of the bell of Gonionemus was studied in relation to temperature, with intact animals and also where different operations were made on the nervous system. A number of values of micro are found for intact animals namely 8,100+/-, 10,500+/-, 32,000+/- and 22,500+/-, with critical temperatures at 9.6 degrees , 12.3 degrees , and 14.0 degrees . Four different classes of operations were used: (1) Animals where the nerve ring was cut on two opposite sides of the bell; the micro values found are 10,500+/- and 21,300+/-, with a critical temperature at 13.4 degrees . (2) Animals with four cuts through the nerve ring gave micro = 10,600 +/- and micro = 21,000, with a critical temperature at 13.1 degrees . (3) In animals where the bell was cut in half the temperature characteristic was found to be 16,900. And finally (4) in the animals where the nerve ring was totally removed micro values of 8,100, 16,000+/-, and 29,000 were found, with critical temperatures at 15.0 degrees and 9.4 degrees . These results are discussed from the standpoint of the theory which supposes that definite "temperature characteristics" may be associated with the functional activity of particular elements in a complex functional unit, and that these elements may be separately studied and identified by suitable experimental procedures involving the magnitudes of the respective temperature characteristics and the locations of associated critical temperatures. The swimming bell of medusae with its marginal sense organs permits a fairly direct approach to such questions. It is found that even slight injuries to the marginal nerve ring, for example, produce specific modifications in the temperature relations which are different from those appearing when the organism is cut in half. PMID- 19872421 TI - PHOTIC ORIENTATION BY TWO POINT-SOURCES OF LIGHT. AB - General formulae are derived for the orientation of phototropic organisms in a field illuminated by two point-sources of light in the same horizontal plane. It is shown that formulae previously found may all be derived as special cases of these general equations. PMID- 19872422 TI - INTRACELLULAR OXIDATION-REDUCTION STUDIES : I. REDUCTION POTENTIALS OF AMOEBA DUBIA BY MICRO INJECTION OF INDICATORS. AB - Twenty-five oxidation-reduction indicators were injected in oxidized or reduced form into Amoeba dubia and Amoeba proteus under controlled conditions of oxygen access. (1) Under anaerobiosis the ameba was able to reduce completely all the reversible oxidation-reduction indicators down to and including indigo disulfonate. (2) Under anaerobiosis the ameba was unable to reoxidize six of the most easily oxidizable indicators. (3) Under aerobiosis the ameba was able to reduce completely all the indicators down to and including 1-naphthol-2-sulfonate indo-2, 6-dichlorophenol. Toluylene blue, methylene blue and indigo tetrasulfonate were sometimes completely and sometimes only partly reduced, depending on the quantity of indicator injected and the duration of observation. (4) The time of reduction varied approximately with the size of the injection. Reduction was more rapid under anaerobiosis than under aerobiosis, more rapid in active than in sluggish cells and was retarded by toxic compounds. (5) Sulfonated compounds were somewhat toxic, as a rule. In interpreting reduction phenomena of micro injection, it is necessary to take into consideration the intensity, capacity and rate factors. It then becomes apparent that the ameba has a high reducing potential lying on the rH scale below the zone of indigo disulfonate. The reducing capacity of the ameba seems to be relatively great in the region of the simple indophenols and of a progressively diminishing magnitude as the zone of the indigos is approached. Material of high reduction potential appears to be generated within the ameba at a measurable rate. These phenomena, observed in the interior of the cell with the aid of indicators, parallel very closely those found in reduction electrode studies on bacterial cultures. PMID- 19872423 TI - THE IONIC ACTIVITY OF GELATIN. AB - 2.5 and 1.25 per cent gelatin have been titrated potentiometrically in the absence of salts and in the presence of two concentrations (0.0750 and 0.0375micro) of NaCl, MgCl(2), K(2)SO(4), and MgSO(4). The data have been used to calculate values of +/- S = v(z) - (v - 1)(z), where v(z) = v(2) - (v(2) - v) r(x)/18. The maximum and minimum values of S with NaCl were used to calculate the mean distance (r(x)) between like charges in gelatin. This is found to be 18 A.u. or over (between acid or basic groups) which agrees with the probable value and the titration index dispersion. Thus the data with NaCl are shown to be normal and to obey the equation found to hold for simple weak electrolytes; namely, pK' pK = Sa See PDF for Equation where S is related to the valence and distance by the above equations. Using the NaCl data as a standard the deviations (DeltaS) produced by the other salts are calculated and are found to agree quantitatively with the deviations calculated from equations derived for the simple weak electrolytes. This shows that in gelatin, as in the simple electrolytes, the deviations are related to the "apparent valences" (values which are a function of the true valence and the distance between the groups). The maximum "apparent valences" of gelatin are 2.4 for acid groups (in alkaline solution) and 1.8 for basic groups (in acid solution). These values correspond to the hypothetical condition of zero distance between the groups. They have no physical significance but have a practical utility first as mentioned above, and second in that they may be used in the unmodified Debye-Huckel equation to give the maximum effect of gelatin on the ionic strength. The true effect is probably even lower than these values would indicate. The data indicate that gelatin is a weak polyvalent ampholyte having distant groups and that the molecule has an arborescent structure with interstices permeated by molecules of the solvent and other solutes. The size and shape probably vary with the pH. PMID- 19872424 TI - THE NATURE OF THE IONIZABLE GROUPS IN PROTEINS. AB - Analysis of the experimental titration curves shows that gelatin contains acid groups with dissociation indices at pH 2.9 to 3.5 corresponding quantitatively with the content in dicarboxylic amino acids; and that the acidic group at pH 9.4 in egg albumin agrees with the amount of tyrosine. The amounts of histidine and lysine present in both these proteins agree quantitatively with basic groups at pH 6.1 and pH 10.4 to 10.6, respectively. However, the quantity of the arginine group (pH 8.1) in these proteins is considerably less than the amount of arginine found on hydrolysis. This deficiency is compensated (quantitatively with gelatin and approximately with egg albumin) by a basic group at pH 4.6. The structure of this "4.6 group" should be similar to aniline and cytosine in consisting of an amino group on a conjugated unsaturated (perhaps cyclic) system. It would appear that the 4.6 group is disrupted on hydrolysis, producing arginine, and may be referred to as "prearginine." The presence of prearginine in proteins, instead of the full amount of arginine, has an important effect on the properties. Otherwise the isoelectric point of gelatin would be 8.0 (instead of 4.7) and of egg albumin 6.6 (instead of 4.8), and the titration curves would be quite different in shape between pH 4 and 10. Deamination of gelatin produces no decrease in prearginine, arginine, or histidine groups, but removes nearly all of the lysine group. PMID- 19872425 TI - DIALYSIS WITH STIRRING. AB - Substances to be purified by dialysis are placed in collodion bags together with a toy "marble" or a bubble of air. The bags are stoppered and placed in glass tubes of a rocking machine. Distilled water of the desired temperature is circulated through the tubes (around the bags) at a rate of about 8 cc. per minute per bag while the machine is in motion. The rolling of the marbles or bubbles causes stirring which makes it possible to remove the salts from a protein solution in 24 to 48 hours. PMID- 19872426 TI - THE METABOLISM OF LIVER TISSUE FROM RATS OF DIFFERENT AGES. PMID- 19872427 TI - THE INFLUENCE OF TEMPERATURE ON THE PHOTOSENSORY LATENT PERIOD. AB - 1. The effect of temperature on the photosensory latent period in Pholas dactylus is accurately described by the Arrhenius equation when micro = 18,300. 2. The adequacy of this equation has already been found for two other photosensitive animals, Mya and Ciona, which are very similar in behavior to Pholas. The value of micro is different for each of the three species studied. 3. This is taken to mean that though the organization of the receptor process is the same for the three species, the chemical materials concerned are very likely different. PMID- 19872429 TI - POSITIVE AND NEGATIVE CURRENTS OF INJURY IN RELATION TO PROTOPLASMIC STRUCTURE. PMID- 19872428 TI - THE RELATION OF TIME, INTENSITY AND WAVE-LENGTH IN THE PHOTOSENSORY SYSTEM OF PHOLAS. AB - The most effective point in the visible spectrum for the stimulation of Pholas is 550 mmicro. On the red side, the effectiveness drops rapidly to almost zero. On the violet side, the effectiveness drops to about half, and rises again in such a way as to indicate a possible second maximum in the near ultra-violet. On the basis of certain ideas these data are assumed to represent the properties of the absorption spectrum of the photosensitive system in Pholas. A comparison with Mya shows that the absorption spectra of the photosensitive systems in the animals are distinctly different. Nevertheless the way in which intensity and reaction time are related in the two animals are found to be identical. The conclusion is then drawn from this and from previous work, that although the fundamental properties of the photoreceptor process show an identical organization in several different animals, the materials which compose these processes are specific. PMID- 19872430 TI - OSMOSIS OF LIQUIDS : GENERAL CONSIDERATIONS. PMID- 19872431 TI - ON THE MECHANISM OF TONIC IMMOBILITY IN VERTEBRATES. AB - 1. The durations of successive periods of induced tonic immobility in the lizard Anolis carolinensis was examined as a function of temperature. An automatic recording method was employed and observations were made of 12,000 to 15,000 immobilizations with six animals over a temperature range of 5 degrees to 35 degrees C. during 5 months. 2. The durations of the immobile periods were found to vary rhythmically in most cases. The reciprocal of the duration of the rhythm, i.e., the rate of change of the process underlying the rhythms, when plotted as a function of temperature according to the Arrhenius equation show distributions of points in two straight line groups. One of these groups or bands of points extends throughout the entire temperature range with a temperature characteristic of approximately micro = 31,000 calories, and the other covers the range of 20 degrees to 35 degrees C. with micro equal to approximately 9,000 calories. 3. The initial stimulus in a series of inductions of immobility appears to set off a mechanism which determines the duration of the state of quiescence. Succeeding forced recoveries seem to have no effect on the normal duration of the rhythm. 4. These results are interpreted by assuming the release, through reflex stimulation, of hormonal substances, one effective between 5 degrees and 35 degrees C. and the other effective between 20 degrees and 35 degrees C. These substances are assumed to act as selective inhibitors of impulses from so called "higher centers," allowing impulses from tonic centers to pass to the muscles. 5. In some experiments a progressive lengthening in successively induced periods of immobility was observed. The logarithm of the frequency of recovery when plotted against time in most of these cases (i.e., except for a few in which irregularities occurred) gave a linear function of negative slope which was substantially unaffected by temperature. In these cases it is assumed that a diffusion process is controlling the amount of available A substance. 6. The results are similar to those obtained by Crozier with Cylisticus convexus. The duration of tonic immobility seems to be maintained in both arthropod and vertebrate by the chemical activity of "hormonal" selective inhibitors. The details of the mechanisms differ, but there is basic similarity. 7. Injections of small amounts of adrenalin above a threshold value are found to prolong the durations of tonic immobility of Anolis, by an amount which is a logarithmic function of the "dose." It is possible that internally secreted adrenalin, above a threshold amount, may be involved in the maintenance of tonic immobility. 8. The production of tonic immobility reflexly is a problem distinct from that of the duration of immobility. It is suggested that the onset may be induced by "shock" to the centers of reflex tonus causing promiscuous discharge of these centers with accompanying inhibition of the higher centers. Such a condition may result when an animal is suddenly lifted from the substratum and overturned, or when, as in the case of Anolis, it struggles with dorsum down. This reaction of the "tonic centers" may at the same time lead to discharge of the adrenal glands by way of their spinal connections thus prolonging the state. PMID- 19872432 TI - THE MECHANISM OF THE INFLAMMATORY PROCESS : III. ELECTROPHORETIC MIGRATION OF INERT PARTICLES AND BLOOD CELLS IN GELATIN SOLS AND GELS WITH REFERENCE TO LEUCOCYTE EMIGRATION THROUGH THE CAPILLARY WALL. AB - 1. Quartz particles and certain other particles move cataphoretically in certain soft gelatin gels, with the same velocity as in the sol. The speed is a function of the true viscosity of the sol or gel, and it is See PDF for Structure apparently not altered in these soft gels by the presence of gel structure. It is proportional to the applied difference of potential. 2. This finding is compatible with the fact that certain sols undergo gelation with no increase of the true viscosity although a marked change in the apparent viscosity takes place. 3. Red cells in soft gelatin-serum gels show a distinct difference in behavior. They migrate through the sol or gel with a speed that is about twice as great as the leucocytes and quartz particles, which latter particles migrate with the same velocity. This ratio has been found to hold for serum and plasma. The absolute velocities are comparatively slightly decreased by the presence of the gel. 4. In more concentrated or stiffer gels, leucocytes, red cells and quartz particles all move at first with the same velocity. By producing mechanical softening of these gels (shearing from cataphoretic movement of the micells within the cell) the red cells presently resume their previous property of independent migration through the gel. 5. The movements of particles in gelatin gels produced by a magnetic force or the force of gravity are of a different nature than those movements produced by cataphoresis. 6. The mechanical nature of obstruction to the cataphoretic migration of leucocytes and red cells in fibrin gels is briefly described. 7. The correlation of cataphoresis of microscopic particles in gels with the order of magnitude and nature of the potential differences in the capillary wall, lends additional evidence to the theory that polymorphonuclear leucocyte emigration and migration are dependent upon these potential differences. PMID- 19872433 TI - THE INFLUENCE OF SURFACE CHARGE AND OF CYTOPLASMIC VISCOSITY ON THE PHAGOCYTOSIS OF A PARTICLE. PMID- 19872434 TI - HEMOLYSIS BY SAPONIN AND SODIUM TAUROCHOLATE, WITH SPECIAL REFERENCE TO THE SERIES OF RYVOSH. AB - 1. The series of Ryvosh is obtained when hemolysis of the red cells of the animals concerned occurs with saponin as the lytic agent. 2. The series of Ryvosh is not obtained when R(infinity) is taken as the resistance constant and sodium taurocholate is used to hemolyse the cells of the same animals. 3. The hemolysin sodium taurocholate has been found to differ from saponin in that the time dilution curves are found to approach their respective asymptotes with different values of kappa. PMID- 19872435 TI - ON THE GEOTROPIC ORIENTATION OF YOUNG MAMMALS. AB - Constants in equations of curves describing the geotropic orientation of young rats are repeatedly obtainable from litters of successive generations of the same inbred strains. Different inbred strains have been obtained for which the respective constants are quite unlike. Such findings show how necessary it is to employ biologically uniform material in experiments of this kind. And at the same time they are convenient as a starting point for genetic analysis. PMID- 19872436 TI - GEOTROPIC ORIENTATION IN ARTHROPODS : I. MALACOSOMA LARVAE. AB - The geotropic orientation of caterpillars of Malacosoma americana during progression upon a surface inclined at angle alpha to the horizontal is such that the path makes an average angle theta upward on the plane, of a magnitude proportional to log sin alpha. More precisely, the product (sin alpha) (sin theta) is constant. This is traced to the fluctuation of the pull of the head region upon the lateral musculature of the upper side during the side to side swinging implicated in progression. PMID- 19872437 TI - THE INFLUENCE OF pH UPON THE CONCENTRATION POTENTIALS ACROSS THE SKIN OF THE FROG. AB - The production of concentration P.D.'s across the skin of the frog is very intimately related to the pH of the applied solutions. On the alkaline side of an isoelectric point the dilute solution is electropositive; on the acid side this solution becomes electronegative. When the pH is suddenly lowered from a value more alkaline than this isoelectric point to one considerably more acid the change in polarity may occur within a few seconds. The effect is reversible. When a series of unbuffered solutions at different pH values are applied reversal curves may be obtained. When the concentration gradient is .1 N-.001 N KCl the reversal points lie between pH 4.1 and 4.8. When studied in acetate buffers this electromotive reversal is found to be closely correlated with the electrical charge upon the membrane, as determined by electroendosmosis through it. Reversal occurs between pH 4.9 and 5.2. It is concluded that the electromotive behavior of this material is controlled by some ampholyte, or group of ampholytes, within the membrane. This ampholyte is probably a protein. On both sides of their isoelectric point these membranes, in common with protein membranes, behave as if they retarded or prevented the movement through them of ions of the same electrical sign as they themselves bear, while permitting the movement of ions of the opposite sign. It is suggested that this correlation arises because of electrostatic effects between the charged surfaces and ions in the solution. PMID- 19872438 TI - THE SALTING OUT OF GELATIN INTO TWO LIQUID LAYERS WITH SODIUM CHLORIDE AND OTHER SALTS. AB - 1. Conditions under which gelatin may be salted out into two liquid layers at 35 degrees were studied. 2. The equilibria governing the amounts and composition of the layers salted out with sodium chloride are found to accord with the requirements of the phase rule for the quaternary system gelatin-sodium chloride hydrogen ion-water. 3. So far, soaps and gelatin are found to be surprisingly similar in their behaviour and definite indications are given as to where further similarities may be sought. 4. It is evident from this work that the term "coagulation" as ordinarily applied to the salting out of proteins is definitely a misnomer. PMID- 19872439 TI - GEOTROPIC ORIENTATION IN ARTHROPODS : III. THE FIDDLER CRAB UCA. AB - On an inclined surface the fiddler crab Uca pugnax, during sidewise progression, orients upward through an angle theta on the surface. The extent of negatively geotropic orientation (theta) is a rectilinear function of sin alpha, where alpha is the inclination of the surface to the horizontal. This equation differs from that describing the geotropic orientation of various other animals. The difference is traced to the fact that from an initial position with the transverse axis of the body horizontal the crab is required to turn upward to an extent such that the vertical line from its center of gravity pierces the inclined surface within the base of support provided by the legs. This leads to the equation sec theta/tan alpha = const., which is obeyed within the limits of precision of the measurements. This type of control of geotropic orientation represents an extension of the "muscle tension theory," and is in no sense in conflict with this view. The assumptions underlying the analytical expression connecting theta and alpha are verified by the asymmetry in the orientation of male fiddlers, which is shown to be due to the presence of the enlarged chela and which disappears when the claws are removed. PMID- 19872440 TI - SIGNIFICANCE OF THE CHEMICAL COMPOSITION OF THE SECRETING AND DRY MAMMARY GLAND TO MILK SECRETION. AB - The results herein presented furnish exact critical evidence for one more stage in milk secretion. Cows producing up to 30 pounds of milk at one milking are shown to have the lactose equivalent of all this milk in the udder when milking commences. The average excess of lactose found in the udder after subtracting the amount necessary for the contained milk is equal to 2.1 pounds. This represents the milk retained in the udder when the cow is believed to be dry. These conclusions are further supported by the fact that no sugar is found in the udder in the quiescent state. The study of the total composition of the udder as fat, ash, nitrogen, and lactose, and of the contained milk shows that there is a large excess of fat, ash, and nitrogen in proportion to that necessary for milk formation. The excess of udder lactose over the milk lactose is much less. The lactose would therefore appear to be formed from some element in the blood, probably dextrose, only as needed for the formation of milk. The composition of the dry udder is quite different in certain respects from that of the actively secreting gland. It builds up a fat reserve of a quite different Reichert-Meissl number from that of butter-fat. It has no sugar, its ash content is reduced, and the nitrogen content is like that of the secreting gland. PMID- 19872442 TI - OXIDATION-REDUCTION EQUILIBRIA IN BIOLOGICAL SYSTEMS : I. REDUCTION POTENTIALS OF STERILE CULTURE BOUILLON. PMID- 19872441 TI - THE EFFECT OF CERTAIN ELECTROLYTES AND NON-ELECTROLYTES ON PERMEABILITY OF LIVING CELLS TO WATER. AB - 1. Permeability to water in unfertilized eggs of the sea urchin, Arbacia punctulata, is found to be greater in hypotonic solutions of dextrose, saccharose and glycocoll than in sea water of the same osmotic pressure. 2. The addition to dextrose solution of small amounts of CaCl(2) or MgCl(2) restores the permeability approximately to the value obtained in sea water. 3. This effect of CaCl(2) and MgCl(2) is antagonized by the further addition of NaCl or KCl. 4. It is concluded that the NaCl and KCl tend to increase the permeability of the cell to water, CaCl(2) and MgCl(2) to decrease it. 5. The method here employed can be used for quantitative study of salt antagonism. PMID- 19872443 TI - SPECTROPHOTOMETRIC STUDIES OF PENETRATION : IV. PENETRATION OF TRIMETHYL THIONIN INTO NITELLA AND VALONIA FROM METHYLENE BLUE. AB - Spectrophotometric measurements show that it is chiefly the trimethyl thionin that is present in the sap extracted from the vacuoles of uninjured cells of Nitella or Valonia which have been placed in methylene blue solution at a little above pH 9. Whether these measurements were made immediately or several hours later the same results were obtained. Methylene blue is detected in the sap (1) when the cells are injured or (2) when the contamination of the sap from the stained cell wall occurs at the time of extraction. The sap is found to be incapable of demethylating methylene blue dissolved in it even on standing for several hours. It is somewhat uncertain as to whether the trimethyl thionin penetrated as such from the external methylene blue solution which generally contains this dye as impurity (in too small concentration for detection by spectrophotometer but detectable by extraction with chloroform), or whether it has formed from methylene blue in the protoplasm. The evidences described in the text tend to favor the former explanation. Theory is discussed on basis of more rapid penetration of trimethyl thionin (in form of free base) than of methylene blue, or of trimethyl thionin in form of salt. PMID- 19872444 TI - THE DEATH WAVE IN NITELLA : I. APPLICATIONS OF LIKE SOLUTIONS. AB - Experiments on cutting confirm the prediction that the current of injury will be positive when the cell is in contact with concentrated solutions and negative with dilute solutions. They support the idea that the protoplasm is made up of layers differing considerably in their properties, each having a death curve of simple and regular form, the more rapid alteration of the outer layer making the protoplasm more positive and the more rapid alteration of the inner making it more negative. From the point where the cell is cut a wave of some sort, which we may for convenience call a death wave, passes along the cell, setting up at each point it touches a death process which has the greater speed and intensity the nearer it is to the cut. PMID- 19872445 TI - HEMOLYSIS OF CHICKEN BLOOD. AB - 1. The time-dilution curves are given for the hemolytic action of saponin, sodium taurocholate, and sodium oleate on nucleated chicken erythrocytes. 2. Saponin and sodium taurocholate cause hemolysis but leave the nuclei and ghosts in suspension, thereby making the end-point of hemolysis more arbitrary than the clear end-point for non-nucleated cell hemolysis. 3. The curves of hemolysis by saponin and taurocholate are shown to be of the same nature as are found in the hemolysis of non-nucleated cells. 4. Sodium oleate causes first hemolysis and then, in the stronger solutions, causes karyolysis. Two pairs of values for kappa and c = infinity are thus obtainable for the same reaction, one pair for the destruction of corpuscular membrane, the other pair for the destruction of the nucleus. 5. Viscosity changes are found in the lysin-cell system with strong concentrations of sodium taurocholate and sodium oleate. Time-viscosity curves are given for these changes. 6. Microscopically, the action of these lysins on the nucleated chicken red cell appears to be similar to their action on the non nucleated erythrocytes. PMID- 19872446 TI - ELECTRIC IMPEDANCE OF SUSPENSIONS OF SPHERES. AB - A general expression has been derived for the electric impedance of a suspension of spheres each having a homogeneous non-reactive interior and a thin surface layer with both resistance and reactance. The applications and limitations of impedance measurements on such suspensions are discussed. PMID- 19872447 TI - ELECTRIC IMPEDANCE OF SUSPENSIONS OF ARBACIA EGGS. AB - Apparatus has been designed and constructed for the measurement of the electric impedance of suspensions of Arbacia eggs in sea water to alternating currents of frequencies from one thousand to fifteen million cycles per second. This apparatus is simple, rugged, compact, accurate, and rapid. The data lead to the conclusions that the specific resistance of the interior of the egg is about 90 ohm cm. or 3.6 times that of sea water, and that the impedance of the surface of the egg is probably similar to that of a "polarization capacity". The characteristics of this surface impedance can best be determined by measurements of the capacity and resistance of suspensions of eggs. No specific change has been found in the interior resistance or the surface impedance which can be related either to membrane formation or to cell division. PMID- 19872448 TI - STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE. AB - A study has been made of the relative rates at which various organic non electrolytes diffuse through the dried collodion membrane. It was found that acetone and urea pass through the membrane many times more rapidly than glycerine and that glycerine in its turn diffuses much faster than glucose. It was also demonstrated that the rate of diffusion varies directly with the difference in concentration between the solutions on the two sides of the membrane. It was shown that the presence of glycerine on the two sides of the membrane did not appreciably affect the rate of diffusion of acetone. In a study of the changes going on during the establishment of the stationary diffusion gradient with glucose experiments were described which strongly suggested that many of the membrane channels may gradually become clogged up with glucose molecules so that the diffusion rate decreases from day to day until the stationary gradient is finally reached. In explaining the various experimental data the conception of the collodion membrane as a sieve with pores approximating in smallness the size of individual molecules was utilized. The large differences in the diffusion rates between different substances were then referred to differences in molecular size, the relatively large molecules of glycerine and glucose being unable to pass through many of the smaller pores available for urea and acetone. From the data available it was possible to estimate that 98 per cent of the pore area distributed among holes large enough for the diffusion of acetone was unavailable for the passage of glycerine and that only 0.3 per cent of the pore area available for acetone could be utilized by glucose. In trying to correlate the ratio between the diffusion rates of two different substances with the characteristic concentration potential (Co P) given by the same membrane it was found (1) that with the acetone-glycerine ratio there is no correspondence (2) that with the acetone-glucose ratio a suggestive relation exists and (3) that with the glycerine-glucose ratio a definite correspondence can be shown, the higher ratios being obtained only with membranes giving high CO P values. A rational explanation for these facts was proposed. PMID- 19872449 TI - DARK ADAPTATION IN AGRIOLIMAX. AB - A method is described which measures the excitation of Agriolimax by light, during the progress of light adaptation, by assuming that the orientating effect of continuous excitation is expressed as a directly proportionate tension difference in the orienting muscles of the two sides of the body. The tendency toward establishment of such a tension difference is caused to work against a similar geotropic effect at right angles to the phototropic one. This enables one to study the kinetics of light adaptation, and of dark adaptation as well. The situation in the receptors is adequately described by the paradigm See PDF for Equation similar to that derived by Hecht for the differential sensitivity of various forms, but with the difference that the "dark" reaction is not only "bimolecular" but also autocatalysed by the reaction product S. The progress of dark adaptation is reflected (1) in the recovery of the amplitude of the orientation and (2) in the rates of light adaptation at different levels of the recovery; each independently supports these assumptions, for which the necessary equations have been provided. These equations also account for the relative variabilities of the angles of orientation, and, more significantly, for the two quite different kinds of curves of dark adaptation which are obtained in slightly different types of tests. PMID- 19872450 TI - MEMBRANES FOR ULTRAFILTRATION, OF GRADUATED FINENESS DOWN TO MOLECULAR SIEVES. AB - The use of cellophane in ultrafiltration is recommended. It is shown that after it has been swollen in water it does not hold back molecules such as sucrose but that it holds back all but the finest colloidal particles. Two methods are given for progressively decreasing the size of the pores until the cellophane becomes a very fine molecular sieve. A sieve structure as the chief factor seems most in accordance with our experience of this and other ultrafilters. Collodion membranes may also be used as molecular sieves but their properties are inconstant. Bedicher is a very fine and rapid filtering ultrafilter and pig's bladder holds back a fair proportion of such molecules as sucrose and potassium chloride. Notes are made on the behavior of cellophane in aqueous and non-aqueous solutions. It is emphasized that ultrafiltration is distinctive and has but little relation to diffusion, dialysis, osmosis, electroosmosis or thermodynamics. PMID- 19872451 TI - EFFECTS OF CYANIDE ON THE PROTOPLASM OF AMEBA. AB - The experiments seem to indicate that the toxicity of HCN and KCN for amebae is due to their effect on the cell membrane and not on the internal protoplasm. Concentrated solutions (N/10-N/300) of HCN or KCN produce an initial increase in viscosity of the protoplasm of amebae (immersed) which is followed by liquefaction and disintegration of the cell. Dilute solutions of HCN or KCN decrease the viscosity of the protoplasm of amebae. Injections of HCN or KCN into amebae produce a reversible decrease in viscosity of the protoplasm. PMID- 19872452 TI - THE INJECTION OF SULFATES INTO VALONIA. AB - Potassium chloride and sulfate were injected into the vacuole of Valonia. The surviving cells tolerated the presence of these solutions. Sulfate, although ordinarily absent from the sap, is not rapidly eliminated when introduced. Hence the sulfate occasionally found in cells of normal appearance may have entered due to temporary injury followed by recovery. PMID- 19872453 TI - INTERNAL VERSUS EXTERNAL TOXICITY IN VALONIA. AB - When MnCl(2) is injected into the cells of Valonia macrophysa they live only about half as long as when the same concentration is applied to the exterior of the cell. This is due to toxic action and not to the mechanical disturbance accompanying the injection (since all cells were stabbed in the same manner by the capillary). A variety of explanations are suggested, all of which involve a difference between the inner and outer layers of the protoplasm. PMID- 19872454 TI - STUDIES ON PERMEABILITY OF MEMBRANES : VI. MENSURATION OF THE DRIED COLLODION MEMBRANE (CALCULATION OF DIMENSIONS AND OF RELATIONS TO CERTAIN BIOLOGICAL MEMBRANES). AB - The flat type of dried collodion membrane used by Michaelis and his associates in numerous investigations has been subjected to mensuration in order that the dimensions of these membranes may be placed on record. The membranes had a functioning area of about 30 cm., were approximately 0.1 mm. in thickness and were composed on the average of 87 per cent by volume of collodion and 13 per cent by volume of pores. In reviewing some of the previously reported results of diffusion experiments with non-electrolytes in the light of the calculated values for the total pore area for the same membranes additional evidence was presented to show that a smaller molecule (acetone) probably utilizes a much larger percentage of the total pore area for its diffusion than is available for a larger molecule (glycerol). By using the figures of Fricke and McClendon for the thickness of the membrane of the red blood cell some comparisons were drawn between the dried collodion membrane as a model for certain biological membranes and the red blood cell membrane. In these comparisons emphasis was placed on the exaggerated importance of small electromotive forces and very slight permeabilities when these were associated with membranes of such extreme thinness as the red blood cell membrane. PMID- 19872455 TI - THE PREARGININE IN EDESTIN AND ITS RESISTANCE TO HYDROLYSIS. AB - The titration data of edestin show that all the arginine found on hydrolysis exists in this protein as "prearginine." The extra ionizable groups of histidine, lysine and tyrosine are free in the quantities found on hydrolysis. Part of the extra carboxyl groups of aspartic and glutamic acids are bound as amides, and 50 per cent are bound in some other manner (perhaps anhydride) leaving only about 6 per cent of these groups free to ionize in edestin. The prearginine in edestin is not converted into arginine on hydrolysis with pepsin up to 18 per cent (of the total hydrolysis). In more highly hydrolyzed solutions it is not possible to detect such a conversion, due to high buffering. Complete hydrolysis however converts prearginine into arginine which can be isolated. Hydrolyzed edestin promotes the growth of sarcomatous fibroblasts about equally well whether 5, 14 or 18 per cent hydrolyzed. PMID- 19872456 TI - CHEMICAL ANTAGONISM OF IONS : I. EFFECT OF Na-Mg AND K-Mg MIXTURES ON THE ACTIVITY OF OXALIC DIION. AB - Magnesium ions decrease the activity of divalent organic anions much more than the normal decrease produced by sodium ions. The effect is very large with short chain acids, particularly oxalic acid. The addition of sodium or potassium ions produces a marked decrease in the effect of magnesium diions on the activity of oxalate diions. Quantitative data on 0.005 molar solutions of oxalic diion over a wide range of concentrations of MgCl(2) and of NaCl (or KCl) show that the following equation is obeyed: See PDF for Equation where A is an empirical value dependent on the concentration of oxalate diion (0x(=)). This equation has been shown to hold down to zero ionic strength of Na(+) and K(+), and hence to be valid in the physiological range. These observations are of biological interest since the activity of proteins should (like oxalic acid) show a similar antagonism. PMID- 19872457 TI - CHEMICAL ANTAGONISM OF IONS : II. ANTAGONISM BETWEEN ANIONS AND ALSO BETWEEN CATIONS AND ANIONS IN THEIR EFFECT ON OXALATE ACTIVITY. AB - Sulfate ions (SO(4) (=)) produce an anomalous effect on the ionization of oxalate diion, opposite in direction to the effect of Mg(++) ions. This effect of sulfate is antagonized by the presence of Cl(-) ions according to the equation: See PDF for Equation where f' is the antilog of the increase in pK(2)' due to the sulfate. In solutions containing up to 0.03 molar MgSO(4) the effect of Mg(++) predominates over that of SO(4) (=). Above 0.1 molar the effect of SO(4) (=) predominates and tends to neutralize the initial deviation. In solutions containing fixed amounts of MgCl(2) and varying amounts of NaSO(4) (or vice versa) the effects of these two salts sharply antagonize each other in all proportions. PMID- 19872458 TI - THE BRIGHTNESS OF THE LIGHT OF THE WEST INDIAN ELATERID BEETLE, PYROPHORUS. AB - The maximum brightness of one of the prothoracic light organs of the West Indian elaterid beetles, Pyrophorus (measured at Princeton, New Jersey) was found to be .045 lambert, or .045 lumen per sq. cm. at 20 degrees C. This corresponds to .0002 candle for one organ, or .0004 candle for the pair of prothoracic organs. PMID- 19872459 TI - ON HEMOCHROMOGEN. AB - 1. Every hemochromogen consists of the iron pyrrol complex, reduced heme, combined with some nitrogenous substance. 2. In every hemochromogen there is the equilibrium: Hemochromogen right arrow over left arrow Reduced heme + Nitrogenous substance. 3. Cyanide can form two distinct compounds with reduced heme, one of which is the typical hemochromogen, cyan-hemochromogen. 4. Reduced heme in alkaline solution has a great affinity for cyanide. 5. Cyan-hemochromogen probably contains one cyanide group per heme. 6. The hemochromogen prepared from hemoglobin is a compound of denatured globin and reduced heme. 7. The individual molecule of denatured globin, of hypothetical molecular weight 16,700, can convert at least 10 molecules of reduced heme into hemochromogen. 8. The hemochromogen-forming capacity of globin is, under given conditions, greater than that of edestin, which in turn, is greater than that of zein. PMID- 19872460 TI - SYNERESIS AND SWELLING OF GELATIN. AB - 1. When solid blocks of isoelectric gelatin are placed in cold distilled water or dilute buffer of pH 4.7, only those of a gelatin content of more than 10 per cent swell, while those of a lower gelatin content not only do not swell but actually lose water. 2. The final quantity of water lost by blocks of dilute gelatin is the same whether the block is immersed in a large volume of water or whether syneresis has been initiated in the gel through mechanical forces such as shaking, pressure, etc., even in the absence of any outside liquid, thus showing that syneresis is identical with the process of negative swelling of dilute gels when placed in cold water, and may be used as a convenient term for it. 3. Acid- or alkali-containing gels give rise to greater syneresis than isoelectric gels, after the acid or alkali has been removed by dialysis. 4. Salt-containing gels show greater syneresis than salt-free gels of the same pH, after the salt has been washed away. 5. The acid and alkali and also the salt effect on syneresis of gels disappears at a gelatin concentration above 8 per cent. 6. The striking similarity in the behavior of gels with respect to syneresis and of gelatin solutions with respect to viscosity suggests the probability that both are due to the same mechanism, namely the mechanism of hydration of the micellae in gelatin by means of osmosis as brought about either by diffusible ions, as in the presence of acid or alkali, or by the soluble gelatin present in the micellae. The greater the pressures that caused swelling of the micellae while the gelatin was in the sol state, the greater is the loss of water from the gels when the pressures are removed. 7. A quantitative study of the loss of water by dilute gels of various gelatin content shows that the same laws which have been found by Northrop to hold for the swelling of gels of high concentrations apply also to the process of losing water by dilute gels, i.e. to the process of syneresis. The general behavior is well represented by the equations: See PDF for Equation and See PDF for Equation where P(1) = osmotic pressure of the soluble gelatin in the gel, P(2) = stress on the micellae in the gelatin solution before setting, K(e) = bulk modulus of elasticity, V(o) = volume of water per gram of dry gelatin at setting and V(e) = volume of water per gram of gelatin at equilibrium. PMID- 19872461 TI - THE EFFECT OF THE HYDROGEN ION CONCENTRATION ON THE RATE OF HYDROLYSIS OF GLYCYL GLYCINE, GLYCYL LEUCINE, GLYCYL ALANINE, GLYCYL ASPARAGINE, GLYCYL ASPARTIC ACID, AND BIURET BASE BY EREPSIN. AB - 1. The rate of hydrolysis at different pH values of glycyl glycine, glycyl leucine, glycyl alanine, glycyl asparagine, glycyl aspartic acid and biuret base has been determined. 2. The pH-activity curves obtained in this way differ for the different substrates. 3. The curves can be satisfactorily predicted by the assumption that erepsin is a weak acid or base with a dissociation constant of 10(-7.6) and that the reaction takes place between a particular ionic species of the enzyme and of the substrate. There are several possible arrangements which will predict the experimental results. 4. The rate of inactivation of erepsin at various pH values has been determined and found to agree with the assumption used above, that the enzyme is a weak acid or base with a dissociation constant of about 10(-7.6). 5. It is pointed out that if the mechanism assumed is correct, the determination of a significant value for the relative rate of hydrolysis of various peptides is a very uncertain procedure. PMID- 19872462 TI - THE NATURE OF THE FACTORS WHICH DETERMINE THE SEQUENCE OF GROWTH-CYCLES AND ITS RELATIONSHIP TO THE DIFFERENTIATION OF TISSUES. AB - 1. It has previously been shown by the author and many others that growth, in animals and plants, is an autocatalysed process. In animals it is usual to find that growth occurs in several superimposed autocatalytic cycles. In many cases, in plants and animals, especially if the cycle is one which occupies a large proportion of the growing period, it is found that the velocity-constant of the autocatalysed monomolecular formula falls off as growth proceeds, at first rapidly and later more slowly. 2. It has previously been shown by the author that the fall of the velocity-constant of growth, in the white mouse, is directly proportional to the fall of the nucleo-cytoplasmic ratio, determined by the chemical method of Le Breton and Schaeffer. If we assume this relationship to be generally applicable to the growth of animals and plants, then the following additional conclusions may be deduced, without calling in the aid of any other assumption:- 3. The increase of cytoplasm in any given cycle of growth is proportional to the concurrent increase of nuclear material. 4. The growth of cytoplasm takes place in accordance with a monomolecular formula in which the velocity-constant varies directly as the mass of the nucleus. If we superadd to these facts and deductions the hypothesis that each growth-cycle represents the growth of a separate group of cells within the animal, then the additional conclusions follow:- 5. That the cells which participate in the growth composing any cycle have initially lower nucleo-cytoplasmic ratios than the cells which participated in the preceding cycles. 6. That cells of large nucleo-cytoplasmic ratios in a multicellular animal inhibit the growth of cells which possess smaller ratios. 7. These conclusions collectively imply that the nucleus plays a predominant role in determining the development of the cell in which it resides. PMID- 19872463 TI - THE THERMIC EFFECT OF DEATH. AB - The thermic effect of death as observed on yeast is about 2 gm. calories per gram of dry substance and is therefore very small as compared with the heat produced in most of the exotherm chemical reactions. As the chemical compounds composing living matter have a very great molecular weight, the decomposition of their molecule which brings about death produces more heat than the decomposition of the molecule of some explosive substances. This explains the great instability of the principal compounds of living matter. PMID- 19872464 TI - THE DEATH WAVE IN NITELLA : II. APPLICATIONS OF UNLIKE SOLUTIONS. AB - The hypothesis of protoplasmic layers enables us to predict the bioelectrical behavior of the cell under a great variety of conditions. It is shown in the present paper that this is clearly the case when a death wave passes through different points in contact with unlike solutions. PMID- 19872465 TI - THE VISCOSITY OF BLOOD SERUM, AS A FUNCTION OF TEMPERATURE. PMID- 19872466 TI - FRACTIONATION OF GELATIN. AB - 1. It is possible to fractionate gelatin by means of reprecipitation at 23 degrees C. of a salt-free solution of pH 4.7 into two fractions, one of which is soluble in water at any temperature, and a second one which does not dissolve in water even when heated to 80 degrees C. 2. The proportion of the soluble fraction in gelatin is much greater than of the insoluble one. 3. The insoluble fraction of gelatin does not swell when mixed with water, but it does swell in the presence of acid and alkali which finally dissolve it. 4. Blocks of concentrated gel made by dissolving various mixtures of the soluble and insoluble fractions of gelatin in dilute NaOH swell differently when placed in large volumes of dilute buffer solution pH 4.7 at 5 degrees C. The gel consisting of the insoluble material shows only a trace of swelling, while those containing a mixture of soluble and insoluble swell considerably. The swelling increases rapidly as the proportion of the soluble fraction increases. 5. A 5 per cent gel made up by dissolving the insoluble fraction of gelatin in dilute NaOH loses about 70 per cent of its weight when placed in dilute buffer pH 4.7 at 5 degrees C. A similar gel made up of ordinary gelatin loses only about 20 per cent of its weight under the same conditions. 6. It was not found possible to resynthesize isoelectric gelatin from its components. 7. An insoluble substance similar in many respects to the one obtained by reprecipitation of gelatin is produce on partial hydrolysis of gelatin in dilute hydrochloric acid at 90 degrees C. PMID- 19872467 TI - DARK ADAPTATION AND THE LIGHT-GROWTH RESPONSE OF PHYCOMYCES. AB - 1. A single-celled, elongating sporangiophore of Phycomyces responds to a sufficient increase in intensity of illumination by a brief increase in growth rate. This is the "light-growth response" of Blaauw. 2. The reaction time is compound, consisting of an exposure period and a latent period (this comprising both the true latent period resulting from photochemical action and any "action time" necessary for the response). During the latter period the plant may be in darkness, responding nevertheless at the end of the latent period. 3. Both light adaptation and dark adaptation occur in the sporangiophore. The kinetics of dark adaptation can be accounted for on the basis of a bimolecular reaction, perhaps modified by autocatalysis. Attention is called to the bimolecular nature of the "dark" reaction in all other photosensory systems that have been studied, in spite of the diversity of the photosensitive substances themselves and of the different forms of the responses to light. PMID- 19872468 TI - HEME AND TISSUE IRON. AB - 1. A method is described for estimating the heme in yeast and bees' muscles as pyridine hemochromogen. 2. The difficulties of the method are discussed. 3. The heme as given by the pyridine method is responsible for about 40 per cent of the total iron. PMID- 19872469 TI - SPECTROPHOTOMETRIC STUDIES OF PENETRATION : V. RESEMBLANCES BETWEEN THE LIVING CELL AND AN ARTIFICIAL SYSTEM IN ABSORBING METHYLENE BLUE AND TRIMETHYL THIONINE. AB - The rate of diffusion through the non-aqueous layer of the protoplasm depends largely on the partition coefficients mentioned above. Since these cannot be determined we have employed an artificial system in which chloroform is used in place of the non-aqueous layer of the protoplasm. The partition coefficients may be roughly determined by shaking up the aqueous solutions with chloroform and analyzing with the spectrophotometer (which is necessary with methylene blue because we are dealing with mixtures). This will show what dyes may be expected to pass through the protoplasm into the vacuole in case it behaves like the artificial system. From these results we may conclude that the artificial system and the living cell act almost alike toward methylene blue and azure B, which supports the notion of non-aqueous layers in the protoplasm. There is a close resemblance between Valonia and the artificial system in their behavior toward these dyes at pH 9.5. In the case of Nitella, on the other hand, with methylene blue solution at pH 9.2 the sap in the artificial system takes up relatively more azure B (absorption maximum at 650 mmicro) than the vacuole of the living cell (655 mmicro). But both take up azure B much more rapidly than methylene blue. A comparison cannot be made between the behavior of the artificial system and that of the living cell at pH 5.5 since in the latter case there arises a question of injury to cells before enough dye is collected in the sap for analysis. PMID- 19872470 TI - CARBON DIOXIDE FROM THE UNSEVERED VAGUS NERVE OF THE SNAKE. AB - 1. The vagus nerve of the gopher-snake, Drymarchon corais couperi (Holbrook), discharges carbon dioxide at an average rate of 0.00234 mgm. of gas per gram of nerve per minute. The extremes were 0.0032 mgm. and 0.0017 mgm. 2. These rates were maintained as well when the nerve was separated from its central and its peripheral connections as when these connections were intact showing that the resting metabolism of nerve is a local operation and is not immediately dependent upon distant connections. 3. These observations also point to the conclusion that the passage of normal impulses over a nerve call for an increase of activity that is unobservable by the method employed and that must be small in amount compared with that produced by artificial stimulation. PMID- 19872471 TI - THE PENETRATION OF STRONG ELECTROLYTES. AB - The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10(-8) mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO(3), I, IO(3), and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO(2), SO(3), Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH(4)Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH(3) or NH(4)OH penetrates and is subsequently changed to NH(4)Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID- 19872472 TI - THE PERMEABILITY OF DRY COLLODION MEMBRANES. II. AB - The rate of penetration and the solubility of H, O, N, NH(3), H(2)O, HCl gas, CO(2), formic, acetic, chloracetic, dichloracetic acid, glycerol, phenol and mercury bichloride in dry collodion membranes have been measured. The rate of penetration of H and CO(2) is the same whether the membrane and gas are dry or whether the membrane is immersed in water. The solubility of CO(2), acetic acid, phenol and water in collodion is completely reversible and is proportional to the concentration (or vapor pressure) in low concentrations and independent of the surface of the collodion. The size of the pores has been calculated from the vapor pressure of water in the collodion and from the rate of flow of water through the membrane. The results do not agree and are not consistent with the observed rates of penetration. The relative rates of penetration of the gases bear no relation to the density of the gas. When the results are corrected for the solubility of the substances in the collodion and expressed as the diffusion coefficient in collodion they show that the diffusion coefficient increases rapidly as the molecular weight decreases. PMID- 19872473 TI - PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XIV. THE HYDROGEN ION CONCENTRATION OF THE BLOOD OF CHICKEN EMBRYOS AS A FUNCTION OF TIME. AB - We have studied by means of glass electrodes the hydrogen ion concentration of the blood of chicken embryos from 8 to 20 days. When plotted as a curve, the average data show that a constant change takes place in the measurement, being acid at the beginning of this period and becoming alkaline toward its end. The acid reaction we think was characteristic not only of the embryos of fowl, but of the fetuses of cats and indeed as Warburg has shown of rapidly growing tissue in general. We have suggested the possibility, though we have no data to substantiate the suggestion, that the hydrogen ion concentration may under conditions like these, seeing that the curve of change resembles that of oxygen consumption, be expressive of changes in the rate of metabolism. PMID- 19872474 TI - MODIFICATION OF THE NORTHROP-KUNITZ MICROCATAPHORESIS CELL. AB - A modification of the Northrop-Kunitz microcataphoresis cell is described. Although the theory of von Smoluchowski relating to such systems is in general followed, certain deviations may be encountered which are easily avoided. PMID- 19872475 TI - STUDIES ON PERMEABILITY OF MEMBRANES : VII. CONDUCTIVITY OF ELECTROLYTES WITHIN THE MEMBRANE. AB - Two methods of measuring the electrical conductivity of the dried collodion membrane in contact with an electrolyte solution are described and the results of such measurements with different electrolytes in different ranges of concentration recorded. Some of the difficulties encountered in making these measurements are outlined. Of special interest was the fact that each membrane with each electrolyte showed a maximum level of resistance at a certain point in the dilution scale, a level which was not surpassed by further dilution. It is believed that this level was fixed by the collodion itself rather than by the contiguous electrolyte solution. Its existence limited the results available for reasonable interpretation. In relatively concentrated solutions the conductivity was shown to be approximately proportional to the concentration. With different electrolytes in the same concentration it was shown that the conductivities varied much more than in simple solutions without a membrane and that they fell in the order HCl > KCl > NaCl > LiCl. A method was described whereby the electrolyte content of a membrane in contact with different chloride solutions could be determined. It was shown that a membrane saturated with either 0.5 N HCl or 0.5 N KCl had practically the same total electrolyte content whereas the same membrane in contact with 0.5 N LiCl contained only half the quantity. These results were used in interpreting the conductivity data, the evidence presented strongly suggesting that two factors are operative in causing the widely divergent conductivities recorded with different electrolytes. The first factor depended on the quantity of electrolyte which can enter the membrane pores, a quantity dependent on the size of the pores and the volume of the larger of the two hydrated ions of the electrolyte. This factor was the chief one in determining the difference in conductivity between KCl and LiCl. The second factor was concerned with differences in the mobility of the various cations within the membrane brought about by friction between the moving ions and the pore walls. With KCl and HCl the quantity of electrolytes entering the membrane was in each case the same, being determined by the size of the larger Cl(-) ion. The widely different conductivity values were explained as due to the changes in the mobility of the two cations within the membrane pores. PMID- 19872476 TI - STUDIES ON PERMEABILITY OF MEMBRANES : VIII. THE BEHAVIOR OF THE DRIED COLLODION MEMBRANE TOWARD BIVALENT CATIONS. AB - A STUDY OF THE BEHAVIOR OF THE DRIED COLLODION MEMBRANE TOWARD THE BIVALENT CALCIUM ION SHOWED THAT: 1. There is almost no potential difference established across a membrane separating two calcium chloride solutions of 0.1 and 0.01 N concentrations. 2. The transfer numbers of chlorine and calcium, as measured in electrical transfer experiments, are both close to 0.5. 3. A sample of membrane in equilibrium with a solution of calcium chloride has an extremely high electrical resistance, greater than is observed with solutions of the chlorides of any of the monovalent cations. 4. The total electrolyte content of a membrane in equilibrium with a solution of calcium chloride was only 20 per cent of that observed when the solution was lithium chloride and 10 per cent of that found when the solution was potassium chloride. In explaining these various results it is supposed that (1), (2) and (3) are all the result of (4), that is, of the inability of the calcium ion to penetrate any but the largest of the membrane pores. As the total quantity of electrolyte able to penetrate the membrane is very small the electrical conductivity must also be very small. Moreover, the few larger pores that are large enough to transport the hydrated calcium ion are too large to exert any appreciable effect in decreasing the mobility of the anion. Thus the membrane has no effect in modifying the potentials established across concentration chains with CaCl(2) and the transfer numbers determined experimentally are what one would expect if no membrane were present. PMID- 19872477 TI - THE COMBINATION OF GELATIN WITH HYDROCHLORIC ACID : II. NEW DETERMINATIONS OF THE ISOELECTRIC POINT AND COMBINING CAPACITY OF A PURIFIED GELATIN. AB - 1. Cooper's gelatin purified according to Northrop and Kunitz exhibited a minimum of osmotic pressure and a maximum of opacity at pH 5.05 +/-0.05. The pH of solutions of this gelatin in water was also close to this value. It is inferred that such gelatin is isoelectric at this pH and not at pH 4.70. 2. Hydrogen electrode measurements with KCl-agar junctions were made with concentrated solutions of this gelatin in HCl up to 0.1 M. The combination curve calculated from these data is quite exactly horizontal between pH 2 and 1, indicating that 1 gm. of this gelatin can combine with a maximum of 9.35 x 10(-4) equivalents of H(+). 3. Conductivity titrations of this gelatin with HCl gave an endpoint at 9.41 (+/-0.05) x 10(-4) equivalents of HCl per gram gelatin. 4. E.M.F. measurements of the cell without liquid junction, Ag, AgCl, HCl + gelatin, H(2), lead to the conclusion that this gelatin in 0.1 M HCl combines with a maximum of 9.4 x 10(-4) equivalents of H(+) and 1.7 x 10(-4) equivalents of Cl(-) per gram gelatin. PMID- 19872478 TI - CHEMICAL ANTAGONISM OF IONS : III. EFFECT OF SALT MIXTURES ON GELATIN ACTIVITY. AB - 1.25 per cent gelatin solutions containing enough NaOH to bring them to pH 7.367 (or KOH to pH 7.203) were made up with various concentrations of NaCl, KCl and MgCl(2), alone and in mixtures, up to molar ionic strength. The effects of these salts on the pH were observed. MgCl(2) and NaCl alone lower the pH of the Na gelatinate or the K gelatinate, in all amounts of these salts. KCl first lowers the pH (up to 0.01 M K(+)), then raises the pH. Mixtures of NaCl and KCl (up to 0.09 M of the salt whose concentration is varied) raise the pH; then (up to 0.125 M Na(+) or K(+)) lower the pH; and finally (above 0.125 M) behave like KCl alone. Mixtures of MgCl(2) and NaCl raise the pH up to 0.10 M Na(+), and lower it up to 0.15 M Na(+)regardless of the amount of MgCl(2). Higher concentrations of NaCl have little effect, but the pH in this range of NaCl concentration is lowered with increase of MgCl(2). Mixtures of MgCl(2) and KCl behave as above described (for MgCl(2) and NaCl) and the addition of NaCl plus KCl to gelatin containing MgCl(2) produces essentially the same effect as the addition of either alone, except that the first two breaks in this curve come at 0.07 M and 0.08 M [Na(+) + K(+)] and there is a third break at 0.12 M. In this pH range the free groups of the dicarboxylic acids and of lysine are essentially all ionized and the prearginine and histidine groups are essentially all non-ionized. The arginine group is about 84 per cent ionized. Hence we are studying a solution with two ionic species in equilibrium, one with the arginine group ionized, and one with it non-ionized. It is shown that the effect of each salt alone depends upon the effect of the cation on the activity of these two species due to combination. The anomalous effects of cation mixtures may be qualitatively accounted for if one or both of these species fail to combine with the cations in a mixture in proportion to the relative combination in solutions of each cation alone. Special precautions were taken to ensure accuracy in the pH measurements. The mother solutions gave identical readings to 0.001 pH and the readings with salts were discarded when not reproducible to 0.003 pH. All doubtful data were discarded. PMID- 19872479 TI - CHEMICAL AND PHYSICAL CHANGES IN GELATIN SOLUTIONS DURING HYDROLYSIS. AB - 1. The change in viscosity and the corresponding increase in the carboxyl groups, as determined by the formol titration, has been determined in gelatin solutions during the progress of hydrolysis by pepsin. 2. Very marked changes in viscosity are found to result from very slight chemical changes. If the viscosity is increased by the addition of acid a greater change in viscosity (volume of solute) is caused by the same percentage change in the number of carboxyl groups. The percentage change in the volume of solute, caused by the same percentage increase in the number of carboxyl groups, is independent of the concentration of gelatin. 3. These results are in agreement with the idea that the high viscosity of gelatin solutions is due to the presence of swollen micells, since a slight chemical hydrolysis may be sufficient to rupture a micella and so cause a very large change in viscosity. PMID- 19872480 TI - THE SWELLING OF GELATIN AND THE VOLUME OF SURROUNDING SOLUTION. AB - The swelling of isoelectric gelatin added to various volumes of acid of different concentration at 5 degrees C. has been determined. The swelling is determined only by the concentration of the supernatant solution at equilibrium and is independent of the volume of acid. Similar experiments with unpurified gelatin show that in this case, owing to the presence of neutral salts the swelling is a function of the volume as well as the concentration of acid. Both results are predicted by the Procter-Wilson-Loeb theory of the swelling of gelatin. PMID- 19872481 TI - A METHOD FOR THE DETERMINATION OF DIFFUSION CONSTANTS AND THE CALCULATION OF THE RADIUS AND WEIGHT OF THE HEMOGLOBIN MOLECULE. AB - A method is described for determining the diffusion coefficient of solutes by determining the rate of passage of the solute through a thin porous membrane between two solutions of different concentration. The method has been used to determine the diffusion coefficient of carbon monoxide hemoglobin. This was found to be 0.0420 +/- 0.0005 cm.(2) per day at 5 degrees C. The molecular weight of carbon monoxide hemoglobin calculated by means of Einstein's equation from this quantity is 68,600 +/- 1,000. PMID- 19872482 TI - OSMOSIS OF LIQUIDS. II. PMID- 19872483 TI - THE EFFECT OF VALENCE OF IONS ON CELLULAR PERMEABILITY TO WATER. AB - 1. Permeability to water in unfertilized eggs of the sea urchin, Arbacia punctulata, was studied by measuring the rate of swelling in hypotonic dextrose solution. 2. Permeability is greatly affected by addition of electrolytes in low concentration. 3. A decrease in permeability to water was found with increasing valence of the cation, using a series of cobaltammine chlorides in which the valence of the cation ranged from 1 to 6. 4. Conversely, an increase in permeability to water was found with increasing valence of the anion, using two series of potassium salts in which the valence of the anion ranged from 1 to 4, and 1 to 3, respectively. 5. It is concluded that the effect of electrolytes on permeability to water depends chiefly on the sign and the number of charges on the ion, in the sense that positive ions decrease permeability to water, while negative ions increase permeability to water; and the effectiveness of the ion is greater the higher its valence. 6. Antagonism has been demonstrated between cations and anions in their effect on permeability, and the method employed permits quantitative study of such antagonism. PMID- 19872484 TI - ON PYRIDINE HEMOCHROMOGEN. AB - 1. Cyanide hemochromogen probably contains one cyanide group per heme group. 2. The equilibrium between pyridine hemochromogen and its components, pyridine and reduced heme, is complicated to an unknown extent by the precipitation of reduced heme and the aggregation of pyridine hemochromogen. 3. These complications were not taken into account in R. Hill's experiments on pyridine hemochromogen. 4. Even if Hill's experiments are sound they do not prove his conclusion that pyridine hemochromogen contains two pyridine groups per heme group. PMID- 19872485 TI - THE INFLUENCE OF SIZE, SHAPE AND CONDUCTIVITY OF MICROSCOPICALLY VISIBLE PARTICLES ON CATAPHORETIC MOBILITY. AB - The electrophoretic mobility of microscopically visible particles is independent of size, shape and conductivity of the particle within the limits of the experimental error. This is valid for extreme variations in size, shape and conductivity. PMID- 19872486 TI - THE RELATION BETWEEN TEMPERATURE AND THE PEDAL RHYTHM OF BALANUS. AB - 1. The relation of temperature to the pedal rhythm of Balanus balanoides L. has been studied under otherwise constant conditions. 2. The frequency of movement increases with temperature, showing three groups of thermal increments and three critical temperatures. Five animals yielded micro = 5,700 above 14.5 degrees C. and 12,100 below; 3 gave micro = 7,800 above 9.3 degrees and 22,500 below; while 9 showed micro = 9,500 above 8.1 degrees and 22,100 below. 3. The upper critical temperatures, above which different effects appeared in different animals were 23.4 degrees , 26.0 degrees , and 27.0 degrees . Above 27.0 degrees none of the valves remained open. 4. Excepting the values 5,700 and 9,500, the increments are similar to those previously found to be associated with respiratory and with neuromuscular activities. 5. Dilution of the sea water with from 3 to 4 per cent fresh water decreases the rate without altering the increments. More than 4 per cent dilution causes irregularity. PMID- 19872487 TI - THE RELATION BETWEEN MAXIMUM RATE OF PHOTOSYNTHESIS AND CONCENTRATION OF CHLOROPHYLL. AB - Willstatter and Stoll have studied the rate of photosynthesis as a function of chlorophyll content. However, their experiments fail to reveal any regular relationship between these two quantities, probably because, in order to obtain material differing widely in chlorophyll content, they were obliged to use leaves which were not comparable in other respects. The writer describes a method for varying the chlorophyll content per unit volume of cells of Chlorella vulgaris, maintaining other factors constant. Experiments are described which show that the maximum rate of photosynthesis is a smooth function of the chlorophyll content. PMID- 19872488 TI - PHOTOSYNTHESIS AS A FUNCTION OF LIGHT INTENSITY AND OF TEMPERATURE WITH DIFFERENT CONCENTRATIONS OF CHLOROPHYLL. AB - 1. Photosynthesis reaches its maximum rate at about the same light intensity over the whole range of chlorophyll concentrations studied. 2. Over this range the process shows the same relationship to temperature. The value of the temperature characteristic decreases gradually as the temperature rises. 3. The rate of photosynthesis is more depressed by prussic acid the lower the chlorophyll concentration. 4. These results are interpreted as indicating that photosynthesis possibly involves an autocatalytic reaction, and that chlorophyll must play some part in the process in addition to its role in the absorption of light. PMID- 19872489 TI - RESPIRATION AND GEOTROPISM IN VICIA FABA. I. AB - In this paper there are given the results of a study of the relation of respiration to temperature, in seedlings of Vicia faba, and of the onset of geotropic response. It is shown that with due care and very accurate control of temperature constancy, one can get constant excretion of CO(2) even over fairly long periods. The treatment of the experimental data shows that the Q(10) ratio is of course a valueless "constant," as it is variable; but that the figure obtained for micro, the temperature characteristic (critical thermal increment), 16,250, is perfectly consistent with the values previously obtained for micro in respiratory oxidative processes in similar material. New data on the reaction time for the root of Vicia faba seedlings excited geotropically are given also. The study of the dependence of this time relation on temperature shows micro = 16,110, agreeing quantitatively with the value deduced previously from the relevant data of earlier investigators (Crozier, 1924). This points to the importance of some respiratory oxidative process as the agency controlling the onset of geotropic curvature. PMID- 19872490 TI - THE PHOTOTROPIC EXCITATION OF LIMAX. AB - The photic orientation of Limax creeping geotropically upon a vertical plate is such that the phototropic vector determining the angular deflection beta from the vertical path is proportional to log I. This is proved by the fact that with horizontal illumination tan beta is directly proportional to log I; with non horizontal light rays from a small source the ratio See PDF for Equation is directly proportional to log I (where A = the angle between light rays and the path of orientation), the vector diagram of the field of excitation being in this case not a right-angled triangle. PMID- 19872491 TI - GEOTROPIC ORIENTATION IN ARTHROPODS : II. TETRAOPES. AB - The creeping of the beetle Tetraopes tetraopthalmus during negatively geotropic orientation shows the angles of orientation (theta) on a surface inclined at alpha degrees to the horizontal to be proportional to sin alpha. The direction of orientation easily suffers temporary reversal to positive as result of handling. Mechanical stability during upward progression should be just possible when K(1)cot alpha = K(2)sin theta + K(3)cos theta, the weight of the body being supported on the tripod formed by the legs on either side and by the posterior tip of the abdomen. Lack of this stability produces tensions on the legs through (1) the bilaterally distributed pull of the body mass on the legs, and (2) the torque on the legs due to the weight of the abdomen. The downward gravitational displacement of the tip of the abdomen causes K(2) and K(3) in the preceding formula to be functions of alpha. These relations have been tested in detail by shifting the location of the center of gravity, by attaching additional masses anteriorly and posteriorly, and by decreasing the total load through amputation of the abdomen; the latter operation changes the conditions for stability. Different formulae are thus obtained (cf. earlier papers) for the orientation of animals in which the mechanics of progression and the method of support of the body weight on an inclined surface are not the same. This demonstrates in a direct way that the respective empirical equations cannot be regarded as accidents. The results are in essence the same as that already obtained with young mammals. The diversity of equations required for the physically unlike cases merely strengthens the conception of geotropic orientation as limited by the tensions applied to the musculature of the body (caterpillars, slugs) or of appendages (beetles, and certain other forms) when the body is supported upon an inclined surface, since equations respectively pertaining to the several instances, and satisfactorily describing the observations, are deduced on this basis. PMID- 19872492 TI - SALT ERROR OF INDICATORS DUE TO STANDARD ALKALINE BUFFERS THEMSELVES. II. AB - Previous results of the comparison of colors given by indicators in alkaline buffers and pure aqueous sodium hydroxide have been repeated and confirmed. The electrometric determinations show that the sodium hydroxide was pure and gave theoretical values for the concentration of hydroxyl ion. The slight but distinct neutralising effect of dilute solutions of alkali has been measured electrometrically and the allowances to be made are recorded graphically. It is found that whereas alizarin yellow G, tropaeolin O and thymol violet may be used without appreciable error (in accordance with our previous communication) the grave discrepancies remain for phenolphthalein, o-cresol phthalein and thymol blue and phenol red which must be ascribed to salt error in the alkaline buffer itself. PMID- 19872493 TI - THE CATAPHORETIC VELOCITY OF MAMMALIAN RED BLOOD CELLS. AB - 1. No significant change with time (to 24 hours) in the cataphoretic velocity of certain mammalian red cells occurs when the cells are suspended in M/15 phosphate buffer at pH = 7.35. Neither successive washings nor standing effect a change. 2. In M/15 phosphate buffer at pH 7.35 +/- 0.03 the following order of red cell velocity has been obtained. The numbers in parenthesis are micro per second per volt per centimeter. See PDF for Structure The order, though not the absolute values, was the same in buffered isotonic dextrose. Human and rabbit cells showed similar differences when both were studied simultaneously in the serum of either. Under these conditions, there is no apparent relationship between zoological Order and cataphoretic velocity. 3. Cholesterol and quartz adsorb gelatin from dilute solution in the phosphate buffer. Red cells, on the other hand, even after 24 hours contact with gelatin solution, retain their previous velocity. 4. Pregnant and non-pregnant white female humans have the same red cell cataphoretic velocity. (The cells were not agglutinated.) 5. In a series of severe anemias no significant change in cataphoretic velocity was in general apparent, although marked changes in the morphology of the red cells were present. PMID- 19872494 TI - THE VISUAL ACUITY OF THE HONEY BEE. AB - 1. Bees respond by a characteristic reflex to a movement in their visual field. By confining the field to a series of parallel dark and luminous bars it is possible to determine the size of bar to which the bees respond under different conditions and in this way to measure the resolving power or visual acuity of the eye. The maximum visual acuity of the bee is lower than the lowest human visual acuity. Under similar, maximal conditions the fineness of resolution of the human eye is about 100 times that of the bee. 2. The eye of the bee is a mosaic composed of hexagonal pyramids of variable apical angle. The size of this angle determines the angular separation between adjacent ommatidia and therefore sets the structural limits to the resolving power of the eye. It is found that the visual angle corresponding to the maximum visual acuity as found experimentally is identical with the structural angular separation of adjacent ommatidia in the region of maximum density of ommatidia population. When this region of maximum ommatidia population is rendered non-functional by being covered with an opaque paint, the maximum visual acuity then corresponds to the angular separation of those remaining ommatidia which now constitute the maximum density of population. 3. The angular separation of adjacent ommatidia is much smaller in the vertical (dorso-ventral) axis than in the horizontal (anterio-posterior) axis. The experimentally found visual acuity varies correspondingly. From this and other experiments as well as from the shape of the eye itself, it is shown that the bee's eye is essentially an instrument for uni-directional visual resolution, functional along the dorso-ventral axis. The resolution of the visual pattern is therefore determined by the vertical angular separation of those ocular elements situated in the region of maximum density of ommatidia population. 4. The visual acuity of the bee varies with the illumination in much the same way that it does for the human eye. It is low at low illuminations; as the intensity of illumination increases it increases at first slowly and then rapidly; and finally at high intensities it becomes constant. The resolving power of a structure like the bee's eye depends on the distance which separates the discrete receiving elements. The data then mean that at low illuminations the distance between receiving elements is large and that this distance decreases as the illumination increases. Since such a moving system cannot be true anatomically it must be interpreted functionally. It is therefore proposed that the threshold of the various ommatidia are not the same but that they vary as any other characteristic of a population. The visual acuity will then depend on the distance apart of those elements whose thresholds are such that they are functional at the particular illumination under investigation. Taking due consideration of the angular separation of ommatidia it is possible to derive a distribution curve for the thresholds of the ommatidia which resembles the usual probability curves, and which describes the data with complete fidelity. PMID- 19872495 TI - THE CONCENTRATION EFFECT IN NITELLA. AB - A METHOD DISTINGUISHING BETWEEN THE CONCENTRATION EFFECT DUE TO THE CELL WALL AND THAT DUE TO THE PROTOPLASM IS DESCRIBED: the importance of this lies in the fact that if the protoplasm shows a concentration effect one or both ions of the salt must tend to enter its outer surface. Studies on the concentration effect of KCl with living protoplasm of Nitella show that when P.D. is plotted as ordinates and the logarithm of concentration as abscissae the graph is not the straight line demanded in the ideal case by theory but has less slope and is somewhat concave to the axis of the abscissae. With a variety of salts the dilute solution is positive, which indicates that the cation has a greater mobility in the protoplasm than the anion or that the partition coefficient of the cation (A(c)) increases faster than that of the anion (A(a)) as the concentration increases. If the result depended on the partition coefficients we should say that when A(c) / A(a) increases with concentration the dilute solution is positive. When A(c) / A(a) decreases as the concentration increases the dilute solution is negative. In either case the increase in concentration may be accompanied by an increase or by a decrease in the relative amount of salt taken up. Theoretically therefore there need be no relation between the sign of the dilute solution and the relative amount of salt taken up with increasing concentration. Hypothetical diagrams of the electrical conditions in the cell are given. If we define the chemical effect as the P.D. observed in leading off at two points with equivalent concentrations of different salts we may say that the chemical effect of the protoplasm is very much greater than that of the cell wall. PMID- 19872496 TI - CHEMICAL ANTAGONISM OF IONS : IV. EFFECT OF SALT MIXTURES ON GLYCINE ACTIVITY. AB - The pH of a 0.01 molar solution of glycine, half neutralized with NaOH, is 9.685. Addition of only one of the salts NaCl, KCl, MgCl(2), or CaCl(2) will lower the pH of the solution (at least up to 1 micro). If a given amount of KCl is added to a glycine solution, the subsequent addition of increasing amounts of NaCl will first raise the pH (up to 0.007 M NaCl). Further addition of NaCl (up to 0.035 M NaCl) will lower the pH, and further additions slightly raise the pH. The same type of curve is obtained by adding NaCl to glycine solution containing MgCl(2) or CaCl(2) except that the first and second breaks occur at 0.015 M and 0.085 M NaCl, respectively. Addition of CaCl(2) to a glycine solution containing MgCl(2) gives the same phenomena with breaks at 0.005 M and 0.025 M CaCl; or at ionic strengths of 0.015 microCaCl(2) and 0.075 microCaCl(2). This indicates that the effect is a function of the ionic strength of the added salt. These effects are sharp and unmistakable. They are almost identical with the effects produced by the same salt mixtures on the pH of gelatin solutions. They are very suggestive of physiological antagonisms, and at the same time cannot be attributed to colloidal phenomena. PMID- 19872497 TI - THE EFFECT OF SUDDEN CHANGES OF TEMPERATURE ON PROTOPLASMIC STREAMING. AB - A sudden fall of temperature of 15 degrees to 20 degrees causes a complete cessation of the protoplasmic streaming in Nitella. The recovery of the normal rate follows a definite course and the time of recovery is dependent on the temperature. Evidence is adduced to show that the inhibition of streaming is due to a physical phenomenon. PMID- 19872498 TI - A GLASS ELECTRODE APPARATUS FOR MEASURING THE pH VALUES OF VERY SMALL VOLUMES OF SOLUTION. AB - A glass electrode apparatus is described with which pH measurements can be made with as small volumes as 2 drops (about 0.14 cc.) of solution. Using this apparatus the change of pH of the vacuolar sap of Nitella, due to the penetration of brilliant cresyl blue, has been readily followed. The sap and the dye have been found to poison the usual type of hydrogen electrode. PMID- 19872500 TI - A METHOD FOR THE TITRATION OF COMPLEMENT. PMID- 19872499 TI - THE VALIDITY OF THE GLASS ELECTRODE IN AMMONIUM CHLORIDE BUFFERS. AB - It is shown that the glass electrode may be used without appreciable error to measure pH of ammonia or ammonium chloride buffers, but that corrections must be applied above pH 8.6 if sodium ions are present in the unknown solution. Corrections are given for values from pH 8.6 to 9.4. A slight further modification of form of glass electrode used by previous workers is described. PMID- 19872501 TI - THE MECHANISM OF COMPLEMENT FIXATION. AB - 1. Complement fixation is obtained in every antigen-antibody reaction involving the presence or formation of a heterogeneous phase (red cells, bacteria, precipitate). 2. The physical constants of fixation (temperature coefficient, velocity, quantitative relationships between the reactants) are those commonly associated with adsorption processes, and are the same in the three types of fixation studied. 3. All the in vitro immune reactions involve an aggregation of immune-serum globulins upon the surface of the antigen. It has been shown that the "fixation" of complement is an adsorption by the aggregates so formed; whether these aggregates are visible as a flocculent precipitate (e.g., sheep serum vs. anti-serum) or concentrated as a surface film on a cellular antigen (sensitized cells; agglutinated bacteria), the reaction is fundamentally the same. 4. As yet, it is unknown whether this adsorption is determined by the physical state of the precipitate, and thus, differs only quantitatively from that by Kaolin, charcoal, normal bacteria, heat-denatured proteins, etc.; or whether the comparatively enormous avidity of these aggregates for complement is due to a specific chemical affinity. PMID- 19872502 TI - MECHANISM OF HEMOLYSIS BY COMPLEMENT : I. COMPLEMENT FIXATION AS AN ESSENTIAL PRELIMINARY TO HEMOLYSIS. AB - 1. Sensitization confers upon the red cell the property of adsorbing complement from solution. The submicroscopic film of immune serum protein deposited upon the cell surface during sensitization, and completely analogous to the precipitate formed in a soluble antigen-antibody reaction (e.g., sheep serum vs. rabbit anti sheep serum) acts as absorbent, the degree of sensitization (size of the film) determining the amount of complement "fixed" (adsorbed). 2. This adsorption of complement by the sensitized cell is an essential preliminary to hemolysis, and when inhibited, even large quantities of demonstrably active complement have no hemolytic action. The marked influence of electrolytes and of the hydrogen ion concentration upon hemolysis is due primarily to corresponding effects upon the fixation of complement by the sensitized cell. In the case of salts with monovalent cations, complement fixation (and hemolysis) is completely inhibited at any concentration < 0.02 M or > 0.35 M. Electrolytes with bivalent cations are much more inhibitory, and in low as concentration 0.07 M completely prevent fixation (and hemolysis). The optimal reaction for complement fixation (and hemolysis) is pH 6.5 to 8.0. In slightly more acid range both are inhibited. But at a reaction pH 5.3, and in the alkaline range, there is an irreversible inactivation of complement, complete at pH 4.8 and 8.8 respectively. It is perhaps more than a coincidence that complement fixation, and therefore, hemolysis, are prevented by just those factors which suppress the ionization of serum proteins, and lead to an increased aggregation state. Between a suspension of macroscopically visible particles of euglobulin in distilled water, and a solution is physiological saline, there is certainly a gradual transition, manifested at low electrolyte concentrations by the opacity of the solution. At pH 7.4, globulin would ionize as a Na-salt, an ionization inhibited as the isoelectric point (5.3) is approached, with a coincident greater tendency of the globulin to separate from solution. And the cataphoretic velocity of particles of globulin, as well as all the other properties which are a function of its ionization (viscosity, osmotic pressure, etc.), are suppressed by electrolytes, the degree of suppression being determined by the concentration and valence of the cation (on the alkaline side of the isoelectric point). The analogy with complement fixation is too complete to be dismissed as fortuitous. 3. The fact that the degree of complement "fixation" increases with the degree of sensitization explains one of the most puzzling phenomena in hemolysis,-that immune serum and complement are, to a certain extent, interchangeable, a decrease in either factor being compensated by an increase in the other (8), (20), (22). The explanation is evident from Figs. 1,2, and 3. The exact quantitative relationships involved will be developed in a later paper. With increasing sensitization there is an enormously more complete and more rapid fixation of complement, and correspondingly more rapid hemolysis, exactly the effect produced by increasing the quantity of complement instead of amboceptor (Fig. 3). All other variables being constant, the velocity of hemolysis is determined by the amount of complement adsorbed. With more amboceptor, a greater proportion is "fixed" by the cell; with more complement, a smaller proportion, but a larger absolute amount. The result is the same: more complement adsorbed, and a corresponding acceleration of hemolysis. If this mobilization of complement is the sole function of immuneserum (and there is as yet no reason to assume any other), then the accepted terminology, in which amboceptor, immune body, and hemolysin are used synonymously, is erroneous. The immune body would function only as an "amboceptor," mobilizing the effective hemolysin, complement, upon the surface of the cell. Nothing has been said of the multiple components into which complement may be split. A priori, it would be expected that the adsorption demonstrated is of the so called midpiece fraction. PMID- 19872503 TI - THE PENETRATION OF LUMINOUS BACTERIA BY THE AMMONIUM SALTS OF THE LOWER FATTY ACIDS : PART I. GENERAL OUTLINE OF THE PROBLEM, AND THE EFFECTS OF STRONG ACIDS AND ALKALIES. AB - It is shown that disappearance of the light of luminous bacteria may be used as a criterion of cell penetration; that luminous bacteria are cytolyzed by water, hypotonic solutions, and by freely penetrating solutions; that luminous bacteria are not injured by hydrogen or hydroxyl ions in the external solutions within the range of pH values employed with the ammonium salts and that therefore disappearance of the light in isotonic solutions of these salts must be due to penetration of the solute; and that there is a characteristic difference between the effects of strong and of weak acids and alkalies on luminous bacteria. PMID- 19872504 TI - RESEMBLANCES BETWEEN THE ELECTROMOTOR VARIATIONS OF RHYTHMICALLY REACTING LIVING AND NON-LIVING SYSTEMS. AB - 1. The electromotor variations of pure iron wires, arranged to react rhythmically with nitric acid, are recorded and described. 2. Resemblances between these variations and those of rhythmically reacting living tissues (especially the heart) are pointed out and discussed. PMID- 19872505 TI - A PRELIMINARY STUDY OF THE REDUCING INTENSITY OF LUMINOUS BACTERIA. AB - The effect of a series of redox indicators and systems has been tested with a suspension of luminous bacteria (B. fischeri) in M/4 phosphate buffer of P(H) = 7.6. The indicators behave as expected from their position in the redox series, the most positive being reduced rapidly even in presence of air and before luminescence of the bacteria disappears, those of intermediate position at the time luminescence disappears, and the more negative only long after the luminescence had ceased, due to utilization of oxygen by the bacterial respiration. Indigo monosulphonate was the only indicator not reduced on long standing of a bacterial suspension. The aerobic redox potential may be placed at an R(H) = 18-20 and the anaerobic potential at an R(H) = 8-10. Ferricyanides do not affect luminescence and behave as if they could not penetrate the bacterial cell. Quinone and the napthoquinones cause progressive dimming of luminescence in any concentration which affects the light but it cannot be definitely stated that this is due to rapid oxidation of luciferin although it seems likely in the case of quinone. Some indophenols dim the luminescence at first, followed by return of brightness, which is interpreted to mean rapid oxidation of luciferin while the indophenol is unreduced, more luciferin production after reduction of indophenol. The more negative redox systems do not affect the luminescence. Investigation of indicator reduction and luminescence is being continued. PMID- 19872506 TI - UNEQUAL DISTRIBUTION OF IONS IN A COLLODION CELL. AB - The properties of dry collodion membranes previously described allow the prediction that cells of these membranes will concentrate solutes under certain conditions. Three such cases have been studied experimentally. 1. A membrane containing thiosulphate and immersed in a solution of iodine concentrates iodide ion. 2. A membrane containing sodium chromate and immersed in mercury chloride concentrates chloride ion. 3. A membrane containing calcium carbonate and immersed in acetic acid concentrates acetate ions. PMID- 19872507 TI - THE RESPIRATION OF LUMINOUS BACTERIA AND THE EFFECT OF OXYGEN TENSION UPON OXYGEN CONSUMPTION. AB - 1. The respiration of luminous bacteria has been studied by colorimetric and manometric methods. 2. Limulus oxyhaemocyanin has been used as a colorimetric indicator of oxygen consumption and indicator dyes were used for colorimetric determination of carbon dioxide production. 3. The Thunberg-Winterstein microrespirometer has been used for the measurement of the rate of oxygen consumption by luminous bacteria at different partial pressures of oxygen. 4. The effect of oxygen concentration upon oxygen consumption has been followed from equilibrium with air to low pressures of oxygen. 5. Luminous bacteria consume oxygen and produce carbon dioxide independent of oxygen pressures from equilibrium with air (152 mm.) to approximately 22.80 mm. oxygen or 0.03 atmosphere. 6. Dimming of a suspension of luminous bacteria occurs when oxygen tension is lowered to approximately 2 mm. Hg (0.0026 atmosphere) and when the rate of respiration becomes diminished one-half. 7. Pure nitrogen stops respiratory activity and pure oxygen irreversibly inhibits oxygen consumption. 8. The curve for rate of oxygen consumption with oxygen concentration is similar to curves for adsorption of gasses at catalytic surfaces, and agrees with the Langmuir equation for the expression of the amount of gas adsorbed in unimolecular layer at catalytic surfaces with gas pressure. 9. A constant and maximum rate of oxygen consumption occurs in small cells when oxygen concentration becomes sufficient to entirely saturate the surface of the oxidative catalyst of the cell. PMID- 19872508 TI - NOTE ON THE NATURE OF THE CURRENT OF INJURY IN TISSUES. AB - Leading off from two places on the same cell (of Nitella) with 0.001 M KCl we observe that a cut produces only a temporary negative current of injury. If we lead off with 0.001 M KCl from any cell to a neighboring cell we find that when sap comes out from the cut cell and reaches the neighboring intact cell a lasting negative "current of injury" is produced. This depends on the fact that the intact cell is in contact with sap at one point and with 0.001 M KCl at the other (this applies also to tissues composed of small cells). If we employ 0.1 M KCl in place of 0.001 M the current of injury with a single cell is positive (and is more lasting when a neighboring cell is present). Divergent results obtained with tissues and single cells may be due in part to these factors. PMID- 19872509 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. I. PMID- 19872510 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. II. AB - 1. Equations describing the geotropic orientation of young rats as a function of the inclination of the surface on which creeping take place, under standardized conditions, are found to be of similar form but with different values of the contained constants, when several different, genetically stabilized lines or races are compared. The values of these constants are characteristic for the several races. 2. The biological "reality" of the differences between young rats of two races, as given mathematical form in terms of these parameters and coefficients, can be submitted to radical test by investigating their behavior in inheritance. A simple result favorable to the inquiry would be decisive; a complex, non-clear result would not however be definitely unfavorable to the view that "real" differences in behavior are in question. The actual result is of a kind demonstrating (a) the efficiency of the original formulations, and (b), at the same time, the definite inheritance of certain quantitative aspects of geotropic behavior. 3. On the assumption that orientation on a sloping surface is achieved when, within a threshold difference, the tension-excitations on the two sides of the body (legs) are the same, the angle of oriented progression (theta) can be taken as a direct measure of the total excitation. This is consistent with the equation, accurately obeyed by our initial races, Delta cos theta/Delta sin alpha = - const., where alpha is the slope of the surface. 4. The total excitation of tension-receptors must be regarded as involving, over a gross interval of time, (1) the total array of receptors with thresholds below a certain value, a function of the stretching force, and (2) the frequency of change of tension. The latter, largely determined (it is assumed) by the frequency of stepping, should be proportional to the speed of progression. This speed is directly proportional to log sin alpha. Hence Deltatheta/Delta log sin alpha. plotted against sin alpha, should give a picture of the distribution of effective thresholds among the available tension-receptors in terms of the exciting component of gravity. For the races investigated this distribution can be resolved in each case into three groups. 5. A "variability number" is employed which permits the demonstration that the variability of theta as measured is (1) definitely controlled by alpha, and is (2) a characteristic number for each of the pure races used. 6. By attaching a weight to rats of one race it is found that Deltatheta/Deltaalpha is modified in a manner concordant with the assumption that the three "groups of sense organs" are in fact discrete. 7. In race K these three groups (I, II, III) are large, in race A, small (i, ii, iii). F(1) rats of the cross between these two races show i, ii, III. 8. F(1) individuals back crossed to A give in the progeny two sorts of individuals, in equal numbers: i, ii, III and i, ii, iii. 9. F(1) individuals back-crossed to K are expected to give in the progeny four types of individuals, I, II; i, II; I, ii; i, ii. In the numbers available these classes are reasonably clear, and occur with equal frequency. 10. It is pointed out that these considerations imply a mode of definition of a gene somewhat different from that commonly employed by tacit assumption; namely, a definition of the effect in inheritance as a function of some controlling, independent variable. PMID- 19872511 TI - THE PREPARATION OF COMPLETELY COAGULATED HEMOGLOBIN. AB - As a preliminary to the study of the reversal of the coagulation of hemoglobin several methods are described for the preparation of completely denatured and coagulated hemoglobin and the evidence is given that hemoglobin is a typical coagulable protein. PMID- 19872512 TI - PROTEIN COAGULATION AND ITS REVERSAL : THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN. AB - 1. The preparation from completely coagulated hemoglobin of crystalline soluble hemoglobin is described. 2. This soluble hemoglobin by all the tests tried has been indistinguishable from normal native hemoglobin which has never been coagulated. 3. The coagulation of hemoglobin is probably reversible. 4. Since hemoglobin is a typical coagulable protein, protein coagulation in general is probably reversible. PMID- 19872513 TI - THE PREPARATION OF RELATIVELY PURE BACTERIOPHAGE. AB - The method described above, based on the electrophoretic migration of bacteriophage particles into an agar gel and their subsequent re-suspension in a suitable medium, has the following advantages: It is simple and can be readily carried out on a comparatively large scale by merely inserting additional units between the same electrode cups. It requires but one extraction and the resulting phage suspension is strongly lytic, an average sample being capable of completely lysing susceptible bacteria at a dilution of 10(-16). The suspension contains no proteins demonstrable by the biuret, alcohol, xanthoproteic, Millon or Hopkins Cole reactions and yields but 0.044 mg. N/cc. directly attributable to the phage. Each corpuscle contains no more nitrogen than a single molecule of protein. In addition the method is applicable to determinations of the electric charge carried by biologically active substances of small dimensions, e.g., phage, toxins, and perhaps some viruses. It offers as well a possible means of purification of these substances. The purified bacteriophage obtained by such a procedure or similar ones is relatively unstable. Work now in progress indicates that it does not possess nearly the resistance to chemical agents, drying, etc., that non-purified phage displays. It is suggested that experiments designed to test the therapeutic value of bacteriophage be conducted, when possible, with purified suspensions thereby avoiding any possibility of obscure non-specific reactions due to other constituents of the lysates. PMID- 19872515 TI - SOME PROPERTIES OF THE PIGMENT OF BLEPHARISMA. PMID- 19872514 TI - MEASUREMENTS OF THE METABOLISM OF TWO PROTOZOANS. AB - 1. The respiration of Amoeba proteus was measured. 10 c. mm. of cells were found to use about 1.6 mm.(3) of oxygen per hour at 20 degrees C. The respiratory quotient was found to be nearly unity. 2. No anaerobic metabolism was found for Amoeba. 3. The respiration of Blepharisma was found to be from 3 to 7 mm.(3) oxygen per hour for 10 mm.(3) cells. The respiratory quotient was about 1. 4. Blepharisma was shown to have a definite anaerobic metabolism. 80 mm.(3) cells caused the evolution of 12.5 mm.(3) carbon dioxide per hour at 20 degrees C. in the presence of bicarbonate. PMID- 19872516 TI - ON THE BEHAVIOR OF NICKEL CARBONATE IN RELATION TO PHOTOSYNTHESIS. AB - The writer was unable to prepare a sample of nickel carbonate which would give any indication of photosynthetic activity. If Professor Baly's preparations are really active, I believe there is some detail in his procedure which he has failed to mention. PMID- 19872517 TI - ELECTROKINETIC PHENOMENA : I. THE ADSORPTION OF SERUM PROTEINS BY QUARTZ AND PARAFFIN OIL. AB - 1. The effect of human and rabbit sera on the cataphoretic mobility of glass and quartz particles, and of paraffin oil droplets, was studied in serum dilutions (with 0.85 per cent NaCl) from 1:50 to 1:1,000,000, over a pH range of 3.6 to 9.3. 2. Under the conditions described, these various types of particles adsorbed protein partially or completely from the most dilute solution giving these particles electrokinetic properties characteristic of certain proteins, probably here those of serum albumin. 3. Quartz particles and paraffin oil droplets both have an isoelectric point between 4.7 and 4.8 in a 1:50 serum dilution. 4. The biological importance of these findings is discussed. 5. A non-polarizable electrode composed of See PDF for Structure is described for use with cataphoresis cells. PMID- 19872518 TI - THE SIZE OF BACTERIA AS THE CAUSE OF THE LOGARITHMIC ORDER OF DEATH. AB - Death of unicellular organisms is brought about by the inactivation of a certain number of essential molecules in the cell. If the number of these essential molecules is only one per cell, the order of death is the same as if the cell were identical with this molecule; the order of death is logarithmic following the mass law. If more than one molecule must be inactivated before the cell dies, the order of death is not logarithmic. With 2 or 3 molecules, it still resembles the logarithmic order, but with an increasing number of reacting molecules, it approaches more and more the order of death known with higher organisms, namely a period of no death, followed by a comparatively short period of rapid death. The decision whether or not the logarithmic order exists, should be based upon the constancy of the death rate See PDF for Equation. The existence of a straight line when logarithms of survivors are plotted against time, is not sufficient proof unless the initial number of cells is included. These deductions are made with the assumption that all organisms are exactly alike, and show no individual variations or graded resistance. With most bacteria, the order of death is so nearly logarithmic that death must be brought about by the inactivation of only one molecule, though there may be several molecules of this same type in each cell. PMID- 19872519 TI - DISSIMILARITY OF INNER AND OUTER PROTOPLASMIC SURFACES IN VALONIA. II. AB - In measurements of P.D. across the protoplasm in single cells, the presence of parallel circuits along the cell wall may cause serious difficulty. This is particularly the case with marine algae, such as Valonia, where the cell wall is imbibed with a highly conducting solution (sea water), and hence has low electrical resistance. In potential measurements on such material, it is undesirable to use methods in which the surface of the cell is brought in contact with more than one solution at a time. The effect of a second solution wetting a part of the cell surface is discussed, and demonstrated by experiment. From further measurements with improved technique, we find that the value previously reported for the P.D. of the chain Valonia sap | Valonia protoplasm | Valonia sap is too low, and also that the P.D. undergoes characteristic changes during experiments lasting several hours. The maximum P.D. observed is usually between 25 and 35 mv., but occasionally higher values (up to 82 mv.) are found. The appearance of the cells several days after the experiment, and the P.D.'s which they give with sea water, indicate that no permanent injury has been received as a result of exposure to artificial sap. If such cells are used in a second measurement with artificial sap, however, the form of the P.D.-time curve indicates that the cells have undergone an alteration which persists for a long time. On the basis of the theory of protoplasmic layers, an attempt has been made to explain the observed changes in P.D. with time, assuming that these changes are due to penetration of KCl into the main body of the protoplasm. PMID- 19872520 TI - PROTOPLASMIC POTENTIALS IN HALICYSTIS. AB - The cells of Halicystis impaled on capillaries reach a steady P.D. of 60 to 80 millivolts across the protoplasm from sap to sea water. The outer surface of the protoplasm is positive in the electrometer to the inner surface. The P.D. is reduced by contact with sap and balanced NaCl-CaCl(2) mixtures; it is abolished completely in solutions of NaCl, CaCl(2), KCl, MgSO(4), and MgCl(2). There is prompt recovery of P.D. in sea water after these exposures. PMID- 19872521 TI - A STUDY OF THE BACTERICIDAL ACTION OF ULTRA VIOLET LIGHT : I. THE REACTION TO MONOCHROMATIC RADIATIONS. AB - In this first paper of a series on the bactericidal action of ultra violet light the methods of isolating and measuring monochromatic radiations, of preparing and exposing the bacteria, and of estimating the effects of exposure, are given in detail. At all the different wave lengths studied the reactions of S. aureus followed similar curves, but occurred, at each wave length, at a different energy level. The general similarity of these curves to those for monomolecular reactions provokes a discussion of their signifiance, and emphasis is laid upon variations in susceptibility of individual organisms, due especially to age and metabolic activity, so that the typical curve seems to be best interpreted as one of probability. PMID- 19872522 TI - A STUDY OF THE BACTERICIDAL ACTION OF ULTRA VIOLET LIGHT : II. THE EFFECT OF VARIOUS ENVIRONMENTAL FACTORS AND CONDITIONS. AB - 1. Wide differences in the intensity of incident ultra violet energy are not accurately compensated by corresponding changes in the exposure time, so that the Bunsen-Roscoe reciprocity law does not hold, strictly, especially for bactericidal action on young, metabolically and genetically active bacteria. In the present series of experiments, however, the energies used at various wave lengths did not differ by so much as to cause a significant error in the reported reactions. 2. The longer wave length limit of a direct bactericidal action on S. aureus was found to be between 302 and 313 mmicro. The shorter limit was not determined because the long exposures required vitiate quantitative results. Bactericidal action was observed at lambda225 mmicro. 3. The temperature coefficient of the bactericidal reaction approaches 1 and thus furnishes empirical evidence that the direct action of ultra violet light on bacteria is essentially physical or photochemical in character. 4. The hydrogen ion concentration of the environment has no appreciable effect upon the bactericidal reaction between the limits of pH 4.5 and 7.5. At pH 9 and 10 evidence of a slight but definite increase in bacterial susceptibility was noted, but this difference may have been due to a less favorable environment for subsequent recovery and multiplication of injured organisms. 5. Plane polarization of incident ultra violet radiation has no demonstrable effect upon its bactericidal action. In a third paper of this group the ratios of incident to absorbed ultra violet energy at various wave lengths and the significance of these relations in an analysis of the bactericidal reaction will be discussed. PMID- 19872523 TI - THE KINETICS OF PENETRATION : I. EQUATIONS FOR THE ENTRANCE OF ELECTROLYTES. AB - When the only solute present is a weak acid, HA, which penetrates as molecules only into a living cell according to a curve of the first order and eventually reaches a true equilibrium we may regard the rate of increase of molecules inside as See PDF for Equation where P(M) is the permeability of the protoplasm to molecules, M(o), denotes the external and M(i) the internal concentration of molecules, A(i) denotes the internal concentration of the anion A(-) and See PDF for Equation (It is assumed that the activity coefficients equal 1.) Putting P(M)F(M) = V(M), the apparent velocity constant of the process, we have See PDF for Equation where e denotes the concentration at equilibrium. Then See PDF for Equation where t is time. The corresponding equation when ions alone enter is See PDF for Equation. where K is the dissociation constant of HA, P(A) is the permeability of the protoplasm to the ion pair H(+) + A(-), and A(ie) denotes the internal concentration of A(i) at equilibrium. Putting P(A)KF(M) = V(A), the apparent velocity constant of the process, we have See PDF for Equation and See PDF for Equation When both ions and molecules of HA enter together we have See PDF for Equation where S(i) = M(i) + A(i) and S(ie) is the value of S(i) at equilibrium. Then See PDF for Equation V(M), V(A), and V(MA) depend on F(M) and hence on the internal pH value but are independent of the external pH value except as it affects the internal pH value. When the ion pair Na(+) + A(-) penetrates and Na(i) = BA(i), we have See PDF for Equation and See PDF for Equation where P(NaA) is the permeability of the protoplasm to the ion pair Na(+) + A(-), Na(o) and Na(i) are the external and internal concentrations of Na(+), See PDF for Equation, and V(Na) is the apparent velocity constant of the process. Equations are also given for the penetration of: (1) molecules of HA and the ion pair Na(+) + A(-), (2) the ion pairs H(+) + A(-) and Na(+) + A(-), (3) molecules of HA and the ion pairs Na(+) + A(-) and H(+) + A(-). (4) The penetration of molecules of HA together with those of a weak base ZOH. (5) Exchange of ions of the same sign. When a weak electrolyte HA is the only solute present we cannot decide whether molecules alone or molecules and ions enter by comparing the velocity constants at different pH values, since in both cases they will behave alike, remaining constant if F(M) is constant and falling off with increase of external pH value if F(M) falls off. But if a salt (e.g., NaA) is the only substance penetrating the velocity constant will increase with increase of external pH value: if molecules of HA and the ions of a salt NaA. penetrate together the velocity constant may increase or decrease while the internal pH value rises. The initial rate See PDF for Equation (i.e., the rate when M(i) = 0 and A(i) = 0) falls off with increase of external pH value if HA alone is present and penetrates as molecules or as ions (or in both forms). But if a salt (e.g., NaA) penetrates the initial rate may in some cases decrease and then increase as the external pH value increases. At equilibrium the value of M(i) equals that of M(o) (no matter whether molecules alone penetrate, or ions alone, or both together). If the total external concentration (S(o) = M(o) + A(o)) be kept constant a decrease in the external pH value will increase the value of M(o) and make a corresponding increase in the rate of entrance and in the value at equilibrium no matter whether molecules alone penetrate, or ions alone, or both together. What is here said of weak acids holds with suitable modifications for weak bases and for amphoteric electrolytes and may also be applied to strong electrolytes. PMID- 19872524 TI - THE SUBSTRATE IN PEPTIC SYNTHESIS OF PROTEIN. AB - 1. Experiments are described in which it was observed that the yield of protein that can be synthesized by pepsin from a given peptic digest is highest when the hydrolyzing action of the pepsin is stopped as soon as all the protein has disappeared from the solution; and that the longer the digest is permitted to contain active enzyme the more the yield diminishes. 2. Exposure of the digest to a hydrogen ion concentration of pH 1.6 in the absence of active enzyme, does not cause a diminution in the amount of protein which can be synthesized from that digest. 3. Synthesis can be effected also in concentrated solutions of isolated fractions of a peptic digest, i.e. of proteose and of peptone. The yields are approximately the same as in similar concentrations of the whole digest, though the proteins so synthesized differ in some respects from those obtained from the whole digest. 4. The cessation of synthesis in any one digest is due to the attainment of equilibrium and not to the complete utilization of available synthesizeable material. The amount of the equilibrium yield, on the other hand, is dependent on the amount of synthesizeable material in the digest. 5. These observations are taken to show that the synthesizeability of a given mixture of protein cleavage products by pepsin depends upon its possession of a special complex in these products. This complex appears as a result of the primary hydrolysis of the protein molecule by pepsin and is decomposed in the slow secondary hydrolysis which ensues as digestion is prolonged. PMID- 19872525 TI - A CRYSTALLOGRAPHIC STUDY OF PURE CARBONMON-OXIDE HEMOGLOBIN. AB - 1. Photomicrographs of crystals of pure carbonmonoxide hemoglobin of the following species are presented; ox, sheep, hog, dog, turkey, rat, horse, chicken and guinea pig. Photomicrographs of the oxyhemoglobin crystals of the following species are also shown: ox, sheep, hog, dog, rat, horse and guinea pig. The crystals were formed from the pure protein by adding a suitable amount of ethyl alcohol and maintaining a temperature of 0 degrees C., or lower. 2. In some species a sufficient difference is shown between the carbonmonoxide hemoglobin and oxyhemoglobin crystals to distinguish these compounds, but the photographs of crystals of carbonmonoxide hemoglobin and oxyhemoglobin of some species, such as guinea pig, show no appreciable difference. 3. Differences between the carbonmonoxide hemoglobins, as well as between the oxyhemoglobins, of the different species studied are indicated. 4. The carbonmonoxide hemoglobin crystals from the bloods studied are species specific in their nature, and, in many cases, can be distinguished from the analogous oxyhemoglobin by crystallographic study. PMID- 19872526 TI - NOTE ON THE VARIATION WITH TEMPERATURE OF THE RELATIVE RATES OF HYDROLYSIS OF GLUCOSIDES. AB - Attention is drawn to the necessity of taking the values of the critical increments into account when the velocity constants for reactions of any pair of glucosides are compared. The ratio of the velocity coefficients for the hydrolysis of any two glucosides, determined at the same temperature, varies with temperature except in the special case when both hydrolyses have the same critical increment. Different values given by various investigators for the same ratio are shown to be due to the fact that comparative experiments have been carried out at different temperatures with two glucosides possessing different critical increments of hydrolysis. In the light of these considerations it becomes necessary to revise certain deductions which have been drawn from the comparison of rates of hydrolysis of glucosides by acids (at fairly high temperatures) with the rates of hydrolysis of glucosides by enzymes (at relatively low temperatures). PMID- 19872527 TI - THE KINETICS OF ENZYME REACTIONS: SCHUTZ'S LAW. AB - 1. A review of the applicability of Schutz's Law to enzymic reactions is given. 2. The theoretical deductions of the Law, (a) on the basis of the law of mass action, (b) on the basis of the adsorption theory, are given and the significance of the assumptions made in these deductions pointed out. 3. It is shown that the true critical increment for an enzymic reaction is equal to twice the critical increment calculated from the Schutz constant k(s), if the heat of decomposition of the enzyme-products complex be neglected. 4. Experiments are described on the tryptic hydrolysis of casein at 30 degrees C. and 404C. The foregoing considerations are applied to the experimental results obtained. PMID- 19872528 TI - OSMOSIS OF LIQUIDS. III. AB - If only one substance S passes through a membrane, the nature of this membrane is not of importance with respect to the direction of the diffusion; this is namely determined only by the O.S.A. of the two liquids. If, however, more substances pass through a membrane, the nature of this membrane is of great importance. If n substances diffuse through a membrane, we can distinguish 2(n) cases, when we take into consideration only the direction in which each of these substances passes through the membrane; if we call each of these cases a D.T. (diffusion type), 2(n)D.T.'s may be conceived. Now we can deduce: one of these D.T.'s is not possible, the other 2(n) x 1 D.T.'s are thermodynamically admissible. The composition of the two liquids determines which of the D.T.'s is not possible; the nature of the membrane determines which of the 2(n) x 1 other D.T.'s will occur. PMID- 19872529 TI - OXIDATION-REDUCTION POTENTIALS AND THE POSSIBLE RESPIRATORY SIGNIFICANCE OF THE PIGMENT OF THE NUDIBRANCH CHROMODORIS ZEBRA. AB - 1. Oxidation-reduction potential methods have been applied to a study of the blue purple pigment present in solution in the blood and in the tissue cells of the nudibranch Chromodoris zebra. 2. The blue-purple pigment and its yellow reduction product form a reversible system whose E(o)' = x0.102 volts at pH 7.0 and whose valence change from oxidant to reductant appears to be one. 3. The system is unlike oxyhemoglobin-hemoglobin in the mode of oxygen transfer. Its role as a possible respiratory material is discussed. PMID- 19872530 TI - THE DIRECT CURRENT RESISTANCE OF VALONIA. AB - A direct current bridge with vacuum tube detector is described for measuring the resistance of living cells. Methods for evaluating the surface of contact with the protoplasm, and the leakage around the cell wall, allow us to calculate the effective resistance of the protoplasm. In Valonia ventricosa this is usually at least 10,000 ohms per square centimeter and is often much higher. This is in agreement with the very slight ionic interchange observed in normal Valonia. PMID- 19872531 TI - THE DARK ADAPTATION OF THE EYE OF LIMULUS, AS MANIFESTED BY ITS ELECTRIC RESPONSE TO ILLUMINATION. AB - 1. The phenomenon of dark adaptation of the eye of Limulus is reflected in the behavior of the action potentials obtained upon stimulation by light. The method of obtaining and recording these action potentials has been described in an earlier paper. 2. By determining the intensity of stimulus necessary to produce an electric response of a given magnitude (as to maximum action potential), at various times during dark adaptation, a quantitative analysis of the process may be made. This analysis is identical with that of Hecht for the dark adaptation of the human eye. 3. The results of this analysis indicate that the process of dark adaptation in the Limulus eye may be represented by a chemical reaction of the second order-the recombination of products of photolysis to renew the depleted supply of photosensitive material. This is in complete accord with Hecht's conception of the photosensory process, and is in quantitative agreement with the results obtained by other methods, in several different animal forms. 4. The experimental relation between strength of stimulus and magnitude of electric response reduces the assumption originally made by Hecht to account for the data on the human eye to an equivalent form; that the magnitude of electric response, provided it be sufficiently large, is directly proportional to the concentration of the photosensitive material in the sense organ. PMID- 19872532 TI - SPECTROPHOTOMETRIC STUDIES OF PENETRATION OF DYES : VII. DYES ABSORBED BY A NON MEDULLATED NERVE. AB - Spectrophotometric measurements show that the non-medullated nerve of a lobster claw is capable of absorbing methylene blue, azure B, or acid fuchsin dissolved in sea water but this does not necessarily imply that the dyes penetrate into the interior of the nerve. PMID- 19872533 TI - THE NON-LOGARITHMIC ORDER OF DEATH OF SOME BACTERIA. AB - In a previous paper, it has been shown that the logarithmic order of death of bacteria can be accounted for by the assumption that each cell contains one or several extremely sensitive molecules and that the destruction or inactivation of any one of these prevents multiplication of the cell. In this paper, the apparent exceptions to the logarithmic order are dealt with. It has been shown that the decreasing death rate can well be accounted for by the assumption of a variation in resistance of the cells under test. The few cases of increasing death rates might be indicative of a different cell structure, requiring the destruction of 2 or 3 molecules before multiplication is made impossible. More probable, however, is the assumption that these bacteria behave exactly like the others, and that the apparently larger number of molecules per cell is caused by our imperfect method of counting living bacteria by the plating method where a cluster of several cells can be counted only as one cell. Bacteria with a tendency for clustering are likely to give results resembling the expectation for several reacting molecules per cell. PMID- 19872534 TI - THE PREPARATION OF A GRADED SERIES OF ULTRAFILTERS AND MEASUREMENT OF THEIR PORE SIZES. AB - A simple procedure for making a series of membranes of graded pore sizes is presented with data for permeability of the membrane series to water and to colloidal sols of known particle sizes. A convenient ultrafiltration apparatus for operation under aseptic conditions is described. PMID- 19872535 TI - PHOTOTROPISM AND THE LIGHT-SENSITIVE SYSTEM OF PHYCOMYCES. AB - 1. The reaction time of the direct growth response of the sporangiophore of Phycomyces to light consists of a series of at least three major identifiable components: (a) an exposure period during which photochemical change occurs; (b) a latent period involving products directly consequent upon the photochemical action; and (c) an action-time occupying a further interval before the growth acceleration appears. 2. The reaction time of the phototropic response of the sporangiophore following stimulation by unilateral illumination is also compound, and is made up of at least three components comparable to those of the direct growth response. 3. The reaction time of each mode of response is constant for a particular intensity of illumination, provided that the duration of the exposure period exceeds a certain value. Below that value the reaction time increases progressively as the exposure time decreases. 4. The reaction time of each mode of response is found to vary similarly as a function of the duration of exposure to light. It is therefore concluded that the two responses are based on the same light-sensitive system. This conclusion accords with the conception of plant phototropism developed by Blaauw. 5. If a constant representing the action-time is subtracted from the reaction times for either mode of response, the reciprocals of the resulting numbers follow a linear sequence when plotted against the durations of the exposure to light. The rate of the process occurring during the latent period is therefore considered to be directly proportional to the amount of preceding photochemical change. PMID- 19872536 TI - THE PERMEABILITY OF THE SURFACE OF MARINE ANIMALS. AB - The surfaces of all marine invertebrates which have been experimented upon are permeable for water and also for both the salts or their ions which are in solution in their blood and in sea water. The forces which tend to bring the salt content of the blood into equilibrium with the salt content of the surrounding sea water are just as great as the forces which strive to prevent osmotic differences. The skin of these animals, save in the cases where special modifications have arisen, serves only as a protecting barrier preventing the loss of the body colloids. PMID- 19872537 TI - THE CONCENTRATION EFFECT WITH VALONIA: POTENTIAL DIFFERENCES WITH CONCENTRATED AND DILUTED SEA WATER. AB - The P.D. between the interior of a cell of Valonia macrophysa and concentrated or diluted sea water applied externally is given by the empirical equation: See PDF for Equation where P.D.(s.w.) is the value observed when the external solution is sea water. The sign is that of the interior of the cell. In the chain: sea water, concn.(1) | Valonia | sea water, concn.(2) therefore, the more concentrated solution is positive in the external circuit to the more dilute solution. This holds for the concentration range 1.5 sea water to 0.2 sea water, when the dilute solutions are made isotonic with sea water by the addition of a suitable non electrolyte (such as glycerol). Prolonged exposure to these solutions, or brief exposure to very concentrated or very dilute sea water, or to hypotonic solutions, produces in the cell secondary changes which are made evident by the reversal of the sign of the P.D. These changes are to a certain extent reversible, but if allowed to proceed too far they become irreversible, involving permanent injury to the cell. The concentration effect with sea water is shown to be practically the concentration effect for NaCl, the part played by the other salts in sea water being relatively small. PMID- 19872538 TI - NEGATIVE VARIATIONS IN NITELLA PRODUCED BY CHLOROFORM AND BY POTASSIUM CHLORIDE. AB - The results of applying chloroform and KCl to Nitella indicate that a negative variation may be started whenever it is possible to set up along the protoplasm a gradient of potential difference sufficiently steep to produce the necessary outward flow of current. Successive variations may thus be set up. PMID- 19872539 TI - PROTEIN COAGULATION AND ITS REVERSAL : THE PREPARATION OF INSOLUBLE GLOBIN, SOLUBLE GLOBIN AND HEME. AB - 1. By a procedure involving the use of acid acetone hemoglobin may be rapidly separated into a precipitate of denatured globin and an acetone solution of heme. 2. By neutralization procedures the denatured globin may be largely converted into a soluble, apparently native form which can combine with heme to form hemoglobin. 3. The heme may be obtained in acetone-free, slightly alkaline solution without the use of strong alkali which may modify the heme. PMID- 19872540 TI - PROTEIN COAGULATION AND ITS REVERSAL : IMPROVED METHODS FOR THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN. AB - The coagulation of hemoglobin is probably reversible. Several methods are described for preparing soluble crystalline hemoglobin from hemoglobin denatured by HCl or trichloracetic acid. The yield is about 75 per cent. PMID- 19872541 TI - THE CATALYTIC EFFECT OF DYES ON THE OXYGEN CONSUMPTION OF LIVING CELLS. AB - From the experiments described in this paper and in those previously published it can be concluded that dyes which can be reversibly oxidized and reduced, act as catalysts for some oxidative processes taking place in the living cells, as is manifested by an increase in their oxygen consumption. It has been found that the catalytic power of the dyes on the oxygen consumption of starfish eggs (mature, unfertilized) is conditioned by two factors: the reduction potential of the dye and the permeability of the cell surface. Dyes whose E'(o) is towards the positive side of the aerobic reduction potential of the starfish eggs have a maximum catalytic effect. This catalytic power decreases as the E'(o) becomes more negative than the reduction potential of the cell and becomes nil beyond certain limits. When a dye cannot penetrate into the cell, its effect is greatly diminished as in this case only those oxidative processes taking place at the outer surface of the cell can be activated. Whether a dye can act as a catalyst or not is dependent on whether the normal consumption of oxygen by the cell is slower or quicker than the oxidation activated by the dye. The speed of this activation is correlated to (1) the speed at which the dye is reduced by the cell, and (2) the speed at which the leuco-dye is oxidized by the atmospheric oxygen. If one of these two processes is slower than the normal respiration, the dye cannot increase the rate of oxygen consumption (phenol indophenol at low concentrations which is kept reduced by the cell is very slowly reoxidized by atmospheric oxygen, on the other hand safranin and neutral red which are not reduced by the cell or at least too slowly reduced, though rapidly reoxidized by air). It will depend on these two reactions velocities whether a dye will act as catalyst (methylene blue and dyes with similar E'(o) which are quickly reduced by the cell and the leuco-dyes of which are relatively quickly reoxidized). Though this relationship between the reduction potential of the dyes and its catalytic power would seem in contradiction with the well known thermodynamic assumption that there is in general no distinct relationship between the potential and velocity of the reaction, we have pointed out from the literature some of the various experiments where one does recognize this connection. PMID- 19872542 TI - THE DIRECT CURRENT RESISTANCE OF NITELLA. AB - The electrical resistance of Nitella cells to direct current is determined in a Wheatstone bridge, using a vacuum-tube detector, and string galvanometer. Very small currents are passed through the cells, to avoid stimulation. The galvanometer record shows typical transient effects in the living cells at opening and closing of the circuit, due to the development of back E.M.F. With 1 cm. contacts of tap water, and 1 cm. between contacts the resistances of living cells are usually between 1,000,000 and 2,000,000 ohms. They go as high as 3,500,000 ohms when the cells are in the best condition. The resistance falls to about 50,000 ohms immediately after killing. Leakage around the cell is small because the wall is imbibed with tap water. By measuring the resistance of the isolated wall (air-filled), and by varying the areas of contact with intact cells, the effective protoplasmic resistance is calculated. This varies from 100,000 to 700,000 ohms per square centimeter of surface, with a typical value of about 250,000 ohms per square centimeter. This high resistance represents a low permeability for most ions, since the values are nearly as high with contacts of 0.01 M NaCl, CaCl(2), LiCl, NH(4)Cl, and MgSO(4). The resistances are greatly reduced however by solutions of KCl, which is correlated with a high mobility of the K(+) ion in the protoplasm. Electrical stimulation causes a marked reduction of resistance, which may be due to exomosis of KCl. PMID- 19872543 TI - THE EFFECT OF ISOELECTRIC AMINO ACIDS ON THE pH OF A PHOSPHATE BUFFER SOLUTION : A CONTRIBITTION IN SUPPORT OF THE "ZWITTER ION" HYPOTHESIS. AB - The relative merits of the classical conception and of the Zwitter Ion conception of the dissociation of amphoteric electrolytes are discussed, and the following data are presented which confirm the Zwitter Ion hypothesis of Bjerrum, and which are not in accord with the classical view. 1. Amino acids in the isoelectric form resemble strong electrolytes in that they contribute to the ionic strength of the solution. 2. The dielectric constants of aqueous solutions of amino acids, like those of solutions of strong electrolytes greater than 0.02 normal, are considerably greater than that of pure water. 3. The magnitude of the dissociation constants of substituted acetic acids and of glycine, are more easily accounted for with the Zwitter Ion than with the classical conception. PMID- 19872544 TI - THE INFLUENCE OF THE QUANTITY OF NUTRITION UPON THE GROWTH OF THE SUCKLING MOUSE. AB - Under usual conditions, the growth of the suckling mouse is limited by the quantity of mother's milk available. As this limitation is removed the growth curve approaches a parabola, which is abruptly interrupted at the end of the second week, when the natural process of weaning begins. PMID- 19872545 TI - SALT BRIDGES AND NEGATIVE VARIATIONS. AB - A negative variation in Nitella is unable to pass a spot killed by chloroform but can set up a negative variation beyond this spot when a salt bridge is put around it. It can likewise set up a negative variation in a cell of another plant if connected to it by two salt bridges. PMID- 19872546 TI - A METHOD FOR THE QUANTITATIVE ESTIMATION OF BACTERIA IN SUSPENSIONS. AB - A method is described for estimating the cell concentration of bacterial suspensions by measurement of the column lengths of packed cells centrifuged into a capillary tube of fine bore. The total error, under the experimental conditions employed, checked by direct count, was >2 per cent for dense suspensions and about 5 per cent for light suspensions. The method is suitable for work requiring rapid and accurate routine preparation of bacterial suspensions of known cell concentrations. PMID- 19872547 TI - A METHOD FOR THE QUANTITATIVE DETERMINATION OF BACTERIOPHAGE. AB - 1. In the case of the staphylococcus and antistaphylococcus phage studied, with the total volume of the mixture being kept constant, there exists a definite quantitative relationship between C(Phage) and the time required to reduce a particular concentration of growing phage-susceptible bacteria to an arbitrary turbidity end-point. 2. This relationship furnishes a basis for the quantitative estimation of bacteriophage. A method is described having an accuracy within +/-5 per cent. PMID- 19872548 TI - ELASTICITY, DOUBLE REFRACTION AND SWELLING OF ISOELECTRIC GELATIN. AB - Quincke's researches (1904) have demonstrated that when a 20 per cent gelatin gel is allowed to swell in water it gives rise to positive double refraction, as if the gel were under tensile stresses. If, on the other hand, the gel shrinks on being placed in alcohol it becomes negatively double refractive, as if it were compressed. But the double refraction as found by Quincke lasts only during the process of swelling or shrinking, and disappears as soon as the gel reaches a state of equilibrium. This phenomenon was investigated here and it was found that the reason for the disappearance of the double refraction is due to the fact that at equilibrium the percentage change in the size of a gel is equal in all three dimensions and the strain is therefore uniform. Double refraction persists as long as there is a difference in the elastic strain in the three dimensions of the strained material. It was found that when gels are cast on glass slides or in glass frames, so as to prevent swelling in certain directions, the double refraction produced by swelling at 6 degrees C. persists permanently in the gel as long as it is swollen, and is proportional to the percentage change in the linear dimensions of the gel. Gels made up of various concentrations of isoelectric gelatin of less than 10 per cent when placed in dilute buffer of the same pH as that of the isoelectric point of the gelatin shrink and give rise to negative double refraction, while gels of concentrations of more than 10 per cent swell and give rise to positive double refraction. The double refraction produced in either case when divided by the percentage change in the dimensions of the gel and by its changed concentration gives a constant value both for swelling and shrinking. This constant which stands for the double refraction produced in a gel of unit concentration per unit strain is termed here the optical modulus of elasticity since it is proportional to the internal elastic stress in the swollen gelatin. It was found that the optical modulus of elasticity is the same both for gels cast on slides and in frames, although the mode of swelling is different in the two forms of gels. Gels removed from their glass supports after apparent swelling equilibrium, when placed in dilute buffer, begin to swell gradually in all three dimensions and the double refraction decreases slowly, though it persists for a long time. But the double refraction per unit change in dimension and per unit concentration still remains the same as before, thus proving that the internal elastic stress as indicated by the double refraction is brought about by the resistance of the gel itself to deformation. A study was also made on the effect of salts, acid and base on the double refraction of a 10 per cent gel during swelling. The experiments show that below M/8 salts affect very slightly the optical modulus of elasticity of the gel. At higher concentrations of salts the elasticity of the gel is reduced by some salts and increased by others, while such salts as sodium acetate and sodium and ammonium sulfates do not change the elasticity of the gels at all during swelling. The investigated salts may thus be arranged in this respect in the following approximate series: CaCl(2), NaI, NaSCN, NaBr, AlCl(3), NaCl, Na acetate, Na(2)SO(4), (NH(4))(2)SO(4), Al(2)SO(4) and MgSO(4). The first five in the series decrease the elasticity while the last two in the series increase the elasticity of the gels during swelling. Acids and bases in higher concentrations exert a powerful influence on the reduction of the elasticity of the gel but in the range of pH between 2.0 and 10.0 the elasticity remains unaffected. The general conclusions to be drawn from these studies are as follows: 1. Swelling or shrinking produces elastic stresses in gels of gelatin, tensile in the first case and compressive in the second case, both being proportional to the percentage change in the dimensions of the gel. 2. Unsupported gels when immersed in aqueous solutions swell or shrink in such a manner that at equilibrium the percentage change in size is equal in all three dimensions, and the stresses become equalized throughout the gel. 3. Gels cast on glass slides or in frames when immersed in aqueous solutions swell or shrink mostly in one direction, and give rise to unidirectional stresses that can be determined accurately by measuring the double refraction produced. 4. The modulus of elasticity of swelling gelatin gels, as calculated from the double refraction measurements, is the same both for compression and for tension and is proportional to the concentration of gelatin in the gel. 5. The modulus of elasticity of gels during swelling is affected only slightly or not at all by salts at concentrations of less than M/8 and is independent of the pH in the range approximately between 2.0 and 10.0. 6. Higher concentrations of salts affect the modulus of elasticity of gelatin gels and the salts in their effectiveness may be arranged in a series similar to the known Hoffmeister series. 7. Acid and alkali have a strong reducing influence on the elastic modulus of swelling gels. 8. The swelling produced in isoelectric gelatin by salts is due primarily to a change brought about by the salts in the osmotic forces in the gel, but in high concentrations of some salts the swelling is increased by the influence of the salt on the elasticity of the gel. This agrees completely with the theory of swelling of isoelectric gelatin as developed by Northrop and the writer in former publications. 9. The studies of Loeb and the writer on the effect of salts on swelling of gelatin in acid and alkali have been in the range of concentrations of salts where the modulus of elasticity of the gelatin is practically constant, and the specific effect of the various salts has been negligible as compared with the effect of the valency of the ions. In concentrations of salts below M/4 or M/8 the Hoffmeister series plays no role. PMID- 19872549 TI - VARIATION OF BASAL METABOLIC RATE PER UNIT SURFACE AREA WITH AGE. PMID- 19872550 TI - THE VALIDITY OF MINIMAL PRINCIPLES IN PHYSIOLOGY. PMID- 19872551 TI - VARIATIONS IN THE POLARIZATION CAPACITY AND RESISTANCE OF THE SKIN. PMID- 19872552 TI - FORWARD MOVEMENT OF PARAMECIUM AS A FUNCTION OF THE HYDROGEN ION CONCENTRATION. AB - 1. At constant temperatures, and within physiological limits, changes of pH in either direction from the neutral point result in immediate increases in speed of movement of Paramecium. 2. These increases are temporary. In 30 to 45 minutes a minimum of speed is reached. This is followed by a period of recovery lasting about an hour. Finally an equilibrium is found. With inorganic acids (HCl or H(2)SO(4)) the final speed after 3 or 4 hours is that characteristic of prolonged exposure to pH 7.0; on the other hand, 3 or 4 hours after the application of either valeric or carbonic acid, speed is proportional to the [H;prime;] of the external and, probably, of the internal medium. 3. These facts become explicable if we assume that the ionization of an ampholyte superficially localized is essential for the execution of the ciliary stroke. Valeric and carbonic acid, in time, demonstrably penetrate the cell. As a working hypothesis we postulate that internal increase of the [H'] accelerates the rate at which this ampholyte is synthetized; but without actually penetrating the cell, hydrogen or hydroxyl ions in the external medium could also increase the degree to which this ampholyte dissociates. 4. Increased ionization of a fixed quantity of ampholyte and an increase in the rate of its production are in these experiments practically indistinguishable. Hence we assume that immediate and temporary increases of speed resulting from any change of pH, as well as final and permanently higher speed levels manifest only after prolonged exposures to organic acids, involve essentially the same mechanism. PMID- 19872553 TI - HEATING OF SIMPLE SOLUTIONS AND EMULSIONS EXPOSED TO HIGH FREQUENCY HIGH POTENTIAL ELECTROSTATIC FIELDS. AB - 1. It is shown that the absorption in liquid dielectrics is a function of potential gradient (field intensity) as well as frequency and that for values of potential gradient above, at least 70 volts per millimeter, the rate of rise of temperature-frequency curve increases rapidly with frequency. 2. The presence of ions in measurable quantity considerably changes the absorption characteristics and apparently causes the values to remain constant, whereas the values for water drop about 40 per cent, during exposure. The absorption also changes rapidly with the concentration of the electrolyte. 3. Very high absorption values are found for an emulsion of cotton-seed oil in 1 per cent sodium oleate. It is shown that the absorption is due to the colloidal structure (with the possibility that the energy is dissipated at the phase boundaries). PMID- 19872554 TI - THE GEOTROPIC CONDUCT OF YOUNG GUINEA PIGS. AB - Young guinea pigs while progressing on an inclined surface orient upward in a way such that the path of progression is at a mean angle theta to the intersection of the plane with the horizontal. The angle theta increases as the angle alpha of the inclination of the plane increases. The results of this experiment indicate that in principle the formulation of similar behavior in the cases of young rats and mice holds essentially for young guinea pigs, and further supports a general muscle tension theory of the limitation of geotropic orientation. The relation of theta to log sin alpha is sigmoid in character and cos theta is a nearly rectilinear function sin alpha. It is notable however that in this case the functions are in reality compound, being made up of two curves with a break occurring at a slope of alpha = 45 degrees . Observation of a blinded guinea pig in light upon an inclined plane reveals the fact that in the neighborhood of 45 degrees the mode of progression changes. Below this angle the animal walks with the feet on the two sides of the body moving forward alternately, while above alpha = 45 degrees the animal hops in such a way that both front feet and both hind feet move forward together. This change in the mode of progression clearly involves a change in the organization of muscular tensions, and in all probability accounts for the change in the relation of the values of theta to the magnitudes of the slope. The behavior of the mean theta's is closely paralleled by that of their P.E.'s, an automatic check being in this way given upon the significance of the measurements. PMID- 19872555 TI - ELECTROKINETIC PHENOMENA. II : THE FACTOR OF PROPORTIONALITY FOR CATAPHORETIC AND ELECTROENDOSMOTIC MOBILITIES. AB - Two theories which predict different values for the ratio of V(E), the electroendosmotic velocity of a liquid past a surface, to V(p), the electric mobility of a particle of the same surface through the same liquid are discussed. The theory demanding that See PDF for Equation was supported by certain data of van der Grinten for a glass surface. Re-calculation of van der Grinten's data reveals that the ratio varies between 2.1 and 2.8. These results are in accord with previous data of Abramson. It is pointed out that glass is unsuitable for the investigation. The ratio See PDF for Equation is here determined for a flat surface and particles when both are covered by the same proteins. Under these conditions See PDF for Equation The theory is similarly tested for a round surface using a micro-cataphoresis cell. It is shown that See PDF for Equation for a round surface is approximately 1.00. These findings are confirmatory of previous data supporting the view that cataphoretic mobility is independent of the size and shape of the particles when all particles compared have similar surface constitutions. PMID- 19872556 TI - ON THE MECHANISM OF OPSONIN AND BACTERIOTROPIN ACTION : IV. THE ISOELECTRIC POINTS OF CERTAIN SENSITIZED ANTIGENS. AB - Sensitization with increasing concentrations of homologous immune serum shifts the isoelectric point of the antigens studied progressively to the alkaline side. Antigens maximally sensitized with rabbit sera have shown isoelectric points of pH 5.6 to 5.8. The globulins precipitated or salted out of the same immune sera have been isoelectric at pH 5.1 to 5.2. The combination of antigen with antibody depends of course upon specific affinities; the surface properties of the sensitized antigen, agglutination and phagocytosis depend primarily upon the properties of the sensitizing serum substances combined with and deposited on the antigen surface. PMID- 19872557 TI - RESPIRATION OF MAMMALIAN ERYTHROCYTES. AB - Non-nucleated mammalian erythrocytes do not respire even in the presence of sugar, but they do respire after addition of a small amount of methylene blue. It is shown in this paper that aqueous extracts of various organs, especially liver, act in the same way as methylene blue. The respiration of erythrocytes induced by an organ extract is not altered in the presence of carbon monoxide. The content of this respiratory supplement in extracts of organs varies according to the organ: liver and kidney show the best effect; muscle, brain, and blood serum the least. With hemolyzed erythrocytes no respiration can be induced either by methylene blue or by organ extracts. PMID- 19872558 TI - THE KINETICS OF PENETRATION : II. THE PENETRATION OF CO(2)INTO VALONIA. AB - The rate of penetration of CO(2) into living cells of Valonia has been studied at high and low pH values. The time curve of penetration appears to be of the first order but with a "velocity constant" which falls off from the start. The evidence indicates little penetration of ions. This is shown by (a) the similarity of velocity "constants" at high and low pH values, (b) the rate of penetration, which remains constant as long as the external concentration of undissociated CO(2) remains constant no matter how much the concentration of ions varies. PMID- 19872559 TI - CALCULATIONS OF BIOELECTRIC POTENTIALS : I. EFFECTS OF KCl AND NaCl ON NITELLA. AB - The P.D. of 0.01 Mvs. 0.001 M KCl (concentration effect) in Nitella is 54.7 mv. and that of NaCl is 20.9 mv. The P.D. of 0.01 M NaCl vs. 0.01 M KCl is 82.9 mv. If we assume that diffusion potentials predominate we may calculate the relative mobilities of the ions in the outer layer of the protoplasm. If we put v(Cl) = 1 we obtain u(K) = 85.45 and u(Na) = 2.18. (These values depend upon the fact that the mean ionic activities in this layer must be equal at equilibrium to the mean ionic activities in the external solution.) Using these values the calculated P.D. of 0.01 M NaCl vs. 0.005 M NaCl + 0.005 M KCl is 66 mv. (the observed value is 68.8 mv.) and the conductance of KCl in the outer layer of the protoplasm is 27 times as great as that of NaCl (the observed conductance for the whole protoplasm is 25 to 50 times greater for KCl than for NaCl). Calculations on the basis of phase boundary potentials are less satisfactory. PMID- 19872560 TI - THE CELL SAP OF HALICYSTIS. AB - Analysis was made of 25 cc. of vacuolar sap, obtained from over 300 cells of Halicystis collected in their position of growth in Bermuda. The determinations agree very well with those of the stranded cells, except that there is even less potassium present. The K:Na ratio is 0.0114. PMID- 19872561 TI - CRYSTALLINE PEPSIN : I. ISOLATION AND TESTS OF PURITY. AB - A method is described for the preparation of a crystalline protein from commercial pepsin preparations which has powerful peptic activity. The composition, optical activity, and proteolytic activity of this protein remain constant through seven successive crystallizations. No evidence for the presence of a mixture or of a solid solution is found in a study of the solubility of the protein in a series of different salt solutions, nor from the diffusion coefficient or from the rate of inactivation. These results indicate that the material is a pure substance or possibly a solid solution of two or more substances having nearly the same solubility in all the various solvents studied. It seems reasonable to conclude from these experiments that the possibility of a mixture must be limited to a mixture of proteins, so that the conclusion seems justified that pepsin itself is a protein. PMID- 19872562 TI - CRYSTALLINE PEPSIN : II. GENERAL PROPERTIES AND EXPERIMENTAL METHODS. AB - A number of properties of crystalline pepsin have been determined and are summarized in Table II. The experimental procedure used is described. PMID- 19872563 TI - SOLUBILITY CURVES OF MIXTURES AND SOLID SOLUTIONS. AB - It is shown that the relative amounts and the solubilities of the two components of a mixture or solid solution may be calculated from the solubility curve of the mixture or the solid solution. PMID- 19872564 TI - THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL : I. INTACT VALONIA VENTRICOSA. AB - Many of the freshly gathered cells of Valonia ventricosa have a resistance to direct current which is variable and depends on the potential applied. It is low when low potentials are applied and rises sharply at higher values. The rise may be more than 100 per cent in the cell as a whole, which is equivalent to several hundred per cent in the protoplasm alone. The rise becomes less as the cells stand in the laboratory, until a maximum is reached at all applied potentials, low and high, below the breakdown value (about 100 mv.): the cells are then said to be in a constant state. During the variable state, the resistance rises when the positive current enters the protoplasm from outside, and falls when it passes out from the vacuole (this is determined by killing one end with chloroform). The rise of resistance becomes faster with closely succeeding applications of potential. This is ascribed to the removal from the protoplasm of ions to which it is reversible. There is some evidence that these may be potassium ions. Much of the apparent resistance rise may be accounted for by a back E.M.F. caused by the flow of current. PMID- 19872565 TI - THE ENZYMIC HYDROLYSIS OF PHLORIDZIN. AB - 1. Considering previously published data on the velocity of hydrolysis of glucosides by acids, it is shown that phloridzin, judged from the standpoint of the velocity coefficient and the critical increment for hydrolysis, resembles the gamma-fructosides (sucrose, raffinose and melezitose) more closely than it does the normal glucosides (salicin, arbutin, maltose, etc.). 2. Previous work on the enzymic hydrolysis of phloridzin shows that it is not hydrolysed by emulsin, but that it is hydrolysed by some other enzyme which occurs fairly freely in nature. 3. The difficulty in examining the enzymic hydrolysis of phloridzin lies in its very low solubility. It has been shown, in confirmation of earlier work, that emulsin is definitely without action on phloridzin at various values of pH and of temperature. This result is difficult to reconcile with the beta-glucosidic character commonly ascribed to phloridzin, and with the fact that emulsin hydrolyses (synthetic) phloroglucinol-beta-glucoside, of which phlorizin is regarded as a derivative. 4. Phloridzin is hydrolysed by a yeast maltase preparation, known to contain saccharase. Phloridzin is readily attacked by maltase-free saccharase at 30 degrees C. and pH of 4.45. If the alpha-glucase of the sucrose-splitting enzyme is (as stated) inactive under these conditions, then the enzyme responsible for the hydrolysis of phloridzin is beta-(gamma) fructosidase. 5. The sugar prepared from phloridzin differs from glucose in its specific rotation and in its action towards Bacillus pestis. PMID- 19872566 TI - THE OSMOTIC PRESSURE OF CONCENTRATED SOLUTIONS OF GELATIN IN EQUILIBRIUM WITH SOLUTIONS OF MAGNESIUM CHLORIDE. AB - The osmotic pressures and the membrane equilibrium of chloride ions have been determined for solutions of gelatin in equilibrium with solutions of magnesium chloride containing from 4.0 to 9.0 equivalents per litre. The pressures increase more rapidly than the concentration, an effect represented by a high value of the term "b" in van der Waals' equation p (V - b) = RT. Calculations made by a thermodynamical formula which makes allowances for deviations from the ideal solution laws show that the high value of "b" is not due to an unequal distribution of diffusible ions. The theory that the high values of the hydration estimated from viscosity formulae account for the magnitude of "b" has been examined and the conclusion has been reached that the term "b" for gelatin as well as for haemoglobin is considerably larger than the volume of the protein hydrate. PMID- 19872567 TI - STUDIES ON PENETRATION OF DYES WITH GLASS ELECTRODE : IV. PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA FLEXILIS. AB - Glass electrode measurements of the pH value of the sap of Nitella show that cresyl blue in form of free base penetrates the vacuoles and raises pH value of the sap to about the same degree as the free base of the dye added to the sap in vitro, while the dye salt dissolved in the sap does not alter its pH value. It is proved conclusively that the increase in the pH value of the sap is due only to the presence of the dye and not to some other alkaline substance. Spectrophotometric measurements show that the dye which penetrates the vacuole is chiefly cresyl blue. When the protoplasm is squeezed into the sap, the pH value of the sap is higher than that of the pure sap. Such a mixture behaves very much like the sap in respect to the dye. PMID- 19872568 TI - THE INTRINSIC RHYTHM OF THE TURTLE'S HEART STUDIED WITH A NEW TYPE OF CHRONOGRAPH, TOGETHER WITH THE EFFECTS OF SOME DRUGS AND HORMONES. AB - A chronograph is described for recording continuously the rates of many different kinds of rhythmic processes over long time periods. The rate is read directly from the length of a line of ink, drawn by a moving pen. Rates of beat of excised turtle's hearts in Ringer's solution have been recorded at 25 degrees C. under constant conditions of temperature, pH, and oxygen supply for periods of 36 hours. Regular periodic variations in the fundamental rhythm are figured, as well as rates of extraordinary constancy. The effects of adrenalin, ephedrin, thyroxin, alpha and beta pituitary hormone insulin, nicotin, and atropin are described in the text. PMID- 19872569 TI - THE ACCUMULATION OF ELECTROLYTES : I. THE ENTRANCE OF AMMONIA INTO VALONIA MACROPHYSA. AB - When 0.005 M NH(4)Cl is added to sea water containing cells of Valonia macrophysa ammonia soon appears in the sap and may reach a concentration inside over 40 times as great as outside. It appears to enter as undissociated NH(3) (or NH(4)OH) and tends to reach a pseudoequilibrium in which the activity of undissociated NH(3) (or NH(4)OH) is the same inside and outside. When ammonia first enters, the pH value of the sap rapidly rises but it soon reaches a maximum and subsequently falls off. At the same time there is an increase of halide in the sap which, however, does not run a parallel course to the ammonia accumulation, but it comes to a new equilibrium value and remains constant. The increase in NH(3) in the sap is accompanied by a decrease in the concentration of K. As NH(3) enters the specific gravity of the sap decreases and the cells rise to the surface and continue to grow as floating organisms. The growth of the cells is increased. PMID- 19872570 TI - THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL : II. THIN COLLODION FILMS. AB - The resistance of very thin collodion membranes to direct current bears some resemblance to that of living cells since it varies with the applied potential. With membranes separating two different solutions the resistance varies with the direction (and the voltage) of the applied potential, rising when less mobile ions are carried across the membrane and falling when more mobile ones are so carried. (With some membranes the resistance varies with potential when the same solution is on both sides.) These changes are very prompt and regular. There is a hysteretic effect of previous current flow. But the membranes differ from Valonia cells in that the rise of resistance is largely ohmic, there being little or no polarization potential. PMID- 19872571 TI - THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL : III. IMPALED VALONIA VENTRICOSA. AB - Electrical resistance and polarization were measured during the passage of direct current across a single layer of protoplasm in the cells of Valonia ventricosa impaled upon capillaries. These were correlated with five stages of the P.D. existing naturally across the protoplasm, as follows: 1. A stage of shock after impalement, when the P.D. drops from 5 mv. to zero and then slowly recovers. There is very little effective resistance in the protoplasm, and polarization is slight. 2. The stage of recovery and normal P.D., with values from 8 to 25 mv. (inside positive). The average is 15 mv. At first there is little or no polarization when small potentials are applied in either direction across the protoplasm, nor when very large currents pass outward (from sap to sea water). But when the positive current passes inward there is a sudden response at a critical applied potential ranging from 0.5 to 2.0 volts. The resistance then apparently rises as much as 10,000 ohms in some cases, and the rise occurs more quickly in succeeding applications after the first. When the potential is removed there is a back E.M.F. displayed. Later there is also an effect of such inward currents which persists into the first succeeding outward flow, causing a brief polarization at the first application of the reverse potential. Still later this polarization occurs at every exposure, and at increasingly lower values of applied potentials. Finally there is a "constant" state reached in which the polarization occurs with currents of either direction, and the apparent resistance is nearly uniform over a considerable range of applied potential. 3. A state of increased P.D.; to 100 mv. (inside positive) in artificial sap; and to 35 or 40 mv. in dilute sea water or 0.6 M MgSO(4). The polarization response and apparent resistance are at first about as in sea water, but later decrease. 4. A reversed P.D., to 50 mv. (outside positive) produced by a variety of causes, especially by dilute sea water, and also by large flows of current in either direction. This stage is temporary and the cells promptly recover from it. While it persists the polarization appears to be much greater to outward currents than to inward. This can largely be ascribed to the reduction of the reversed P.D. 5. Disappearance of P.D. caused by death, and various toxic agents. The resistance and polarization of the protoplasm are negligible. The back E.M.F. of polarization is shown to account largely for the apparent resistance of the protoplasm. Its calculation from the observed resistance rises gives values up to 150 mv. in the early stages of recovery, and later values of 50 to 75 mv. in the "constant" state. These are compared with the back E.M.F. similarly calculated from the apparent resistance of intact cells. The electrical capacitance of the protoplasm is shown by the time curves to be of the order of 1 microfarad per cm.(2) of surface. PMID- 19872572 TI - STUDIES ON PENETRATION OF DYES WITH GLASS ELECTRODE : V. WHY DOES AZURE B PENETRATE MORE READILY THAN METHYLENE BLUE OR CRYSTAL VIOLET? AB - Glass electrode measurements of the pH value of the sap of cells of Nitella show that azure B in the form of free base penetrates the vacuoles and raises the pH value of the sap to about the same degree as the free base of the dye added to the sap in vitro, but the dye salt dissolved in the sap does not alter the pH value of the sap. It is concluded that the dye penetrates the vacuoles chiefly in the form of free base and not as salt. The dye from methylene blue solution containing azure B free base as impurity penetrates and accumulates in the vacuole. This dye must be azure B in the form of free base, since it raises the pH value of the sap to about the same extent as the free base of azure B dissolved in the sap in vitro. The dye absorbed by the chloroform from methylene blue solution behaves like the dye penetrating the vacuole. These results confirm those of spectrophotometric analysis previously published. Crystal violet exists only in one form between pH 5 and pH 9.2, and does not alter the pH value of the sap at the concentrations used. It does not penetrate readily unless cells are injured. A theory of "multiple partition coefficients" is described which explains the mechanism of the behavior of living cells to these dyes. When the protoplasm is squeezed into the sap, the pH value of the mixture is higher than that of the pure sap. The behavior of such a mixture to the dye is very much like that of the sap except that with azure B and methylene blue the rise in the pH value of such a mixture is not so pronounced as with sap when the dye penetrates into the vacuoles. Spectrophotometric measurements show that the dye which penetrates from methylene blue solution has a primary absorption maximum at 653 to 655 mmicro (i.e., is a mixture of azure B and methylene blue, with preponderance of azure B) whether we take the sap alone or the sap plus protoplasm. These results confirm those previously obtained with spectrophotometric measurements. PMID- 19872573 TI - A STUDY OF THE BACTERICIDAL ACTION OF ULTRA VIOLET LIGHT : III. THE ABSORPTION OF ULTRA VIOLET LIGHT BY BACTERIA. AB - The simple conclusion of former investigators that the shorter the wave length of ultra violet light the greater the bactericidal action is in error. A study with measured monochromatic energy reveals a characteristic curve of bactericidal effectiveness with a striking maximum between 260 and 270 m.micro. The reciprocal of this abiotic energy curve suggests its close relation to specific light absorption by some single essential substance in the cell. Methods are described for determining the absorption curve, or absorption coefficients, of intact bacteria. These curves for S. aureus and B. coli have important points of similarity and of difference with the reciprocals of the curves of bactericidal incident energy, and point the way in a further search for the specific substance, or substances, involved in the lethal reaction. PMID- 19872574 TI - THE REACTIONS OF CYANIDE WITH GLOBIN HEMOCHROMOGEN. AB - Cyanide can react with globin hemochromogen in two different ways. In the first reaction cyanide combines with globin hemochromogen without displacing or competing with globin. In the second reaction cyanide displaces globin. PMID- 19872575 TI - THE EFFECT OF LOW PRESSURES ON CELL OXIDATION. AB - 1. A method is described for measuring tissue oxidation under reduced barometric pressure. 2. The oxygen uptake of yeast is diminished by low barometric pressures to a greater extent than by a reduction of the partial pressure of oxygen, to a corresponding degree, at atmospheric pressure. 3. This effect of low pressure is not observed with certain in vitro oxidation systems. 4. The anaerobic respiration (carbon dioxide production) of yeast is not at all affected by low pressures. 5. The inhibition of tissue oxidation caused by carbon monoxide is removed by lowering the pressure. PMID- 19872576 TI - CHEMICAL STIMULATION BY ALCOHOLS IN THE BARNACLE, THE FROG AND PLANARIA. AB - 1. The stimulating efficiencies of some normal primary aliphatic alcohols have been determined for the barnacle, the frog, and Planaria, under conditions which do not involve narcosis or simultaneous stimulation by other agents. 2. Concentrations of the successive alcohols necessary to produce a given stimulatory effect vary according to the following geometrical series: 1: a(-1): a(-2): a(-3): a(-4): . . . ., where a represents some real number. 3. Within certain limits the relationship between the logarithm of the concentration necessary to produce a given effect and the reciprocal of the reaction time is linear in the frog and in Planaria. 4. The concentration effect may be expressed by an equation which contains one constant characteristic of the alcohol series, and another one characteristic of each member. The ratio of the latter constants for successive alcohols represents a in the above series. 5. The stimulation by alcohols in these animals is considered to be due to energy changes at the receptive surfaces, brought about by a definite orientation of the respective alcohol molecules. Increase in stimulating efficiency as the number of CH(2) groups increase must be due to the role of the non-polar portion of the alcohol molecule, since the polar group remains practically constant throughout the series. 6. In homologous series of organic compounds it is conceived that stimulating effects will be produced either by the polar group or the non-polar group, according to which one becomes dominant in effect, or to a combination of the two. PMID- 19872577 TI - THE ARGININE AND PREARGININE GROUPS IN EDESTIN. AB - The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the theory that the combination of strong base or strong acid with proteins is produced by the formation of salts with the "extra groups" of those trivalent amino acids which can be isolated from the protein, with the exception of arginine. Arginine contributes to the titration curve in much smaller amount than is found on hydrolysis. This deficiency in the arginine group may be accounted for by the basic group in proteins having a titration index of pG' = 3.8 to 4.6 (depending on the protein), which apparently yields arginine on hydrolysis, and may properly be called prearginine. PMID- 19872578 TI - THE COMBINATION OF EDESTIN WITH HYDROCHLORIC ACID. AB - Electromotive force measurements of cells without liquid junction, of the type Ag, AgCl, HCl + protein, H(2), lead to the conclusion that 1 gm. of edestin (or, more probably, edestan) combines with a maximum of 13.4 x 10(-4) equivalents of H(+) and 3.9 x 10(-4) equivalents of Cl(-), when the protein is dissolved in 0.1 M HCl. PMID- 19872579 TI - ELECTROKINETIC PHENOMENA. III : THE "ISOELECTRIC POINT" OF NORMAL AND SENSITIZED MAMMALIAN ERYTHROCYTES. AB - A survey of the published electrophoretic mobilities of certain mammalian red cells reveals that the isoelectric points accorded to these cells are the result of equilibria incidental to red cell destruction. The electrophoretic mobilities of normal washed sheep and human cells have now been studied in 0.85 per cent NaCl solutions from about pH 3.6 to 7.4. All measurements were made within 2 minutes of the preparation of the suspension of red cells. In no case was reversal of sign of charge observed under these conditions. Reversal of sign of charge occurred only after sufficient time had elapsed to permit sufficient adsorption of the products of red cell destruction. There is little change in mobility as the pH of the medium is decreased. Reversal of sign of charge does occur in the presence of normal and immune (anti-sheep) rabbit sera. The isoelectric point determined under these conditions does not appear to be connected specifically with the immune body but is perhaps associated with phenomena incidental to red cell destruction and the presence of serum. The characteristic lowering of mobility by amboceptor occurs, however, from pH 4.0 to pH 7.4. The curves of mobility plotted against pH for normal and for immune sera support the viewpoint that the identity of the isoelectric points for normal and sensitized sheep cells is not primarily concerned with the immune reaction. It is most unlikely that an "albumin" or a "globulin" surface covers red cells with a complete protein film. Although serum protein reacts with red cells in acid solutions, this is not demonstrable for gelatin. The lowering of mobility usually ascribed to anti-sheep rabbit serum may also occur, but to a lesser degree, in normal rabbit serum. This diminution of mobility is not, in the first place, associated with sensitization to hemolysis induced by complement. This supports the view that only a very small part of the red cell surface need be changed in order to obtain complete hemolysis in the presence of complement. PMID- 19872580 TI - FACTORS INFLUENCING THE RESPIRATION OF ERYTHROCYTES : I. PRIMITIVE AVIAN ERYTHROCYTES. AB - 1. The oxygen consumption of normal and "primitive red cells" of fowls' blood has been determined at intervals in the course of an anemia produced by the injection of phenylhydrazine. The "primitive red cells" have an oxygen consumption at least twenty to twenty-five times greater than the normal red cells. 2. Suspension of the cells derived from the blood in anemia in sodium chloride solutions of various concentrations has comparatively little effect upon the oxygen consumption of the cells. 3. The red cells from anemic blood are sensitive to variations in the reaction of the medium in which they are suspended. The maximum oxygen consumption, after addition of a saline solution containing variable amounts of acid to the blood, took place at pH 7.75. They appeared somewhat more sensitive to variations on the acid side of this reaction than on the alkaline. 4. Addition of glucose to the medium increased the oxygen consumption of the cells. Their metabolism in a physiological saline solution containing 0.6 per cent of glucose was 15 per cent higher than in one in which no glucose was present. 5. Certain amino acids in low concentrations had little effect on oxygen consumption, though at higher concentrations some of them definitely diminished it. PMID- 19872581 TI - FACTORS INFLUENCING THE RESPIRATION OF ERYTHROCYTES : II. MAMMALIAN RETICULOCYTES. AB - 1. The respiration of the reticulocytes of the rabbit has been measured during the period of an anemia produced by phenylhydrazine. Though the respiration increased greatly during the phase of regeneration, the oxygen consumption per billion reticulocytes throughout the period remained approximately the same. 2. The respiration of the reticulocytes was affected by changes in the reaction of the medium in which they were suspended, and was at its maximum about a pH of 8, with a probable intracorpuscular pH of about 7.75. 3. Variations in the tonicity of the suspending medium did not produce any great change in the respiration of the reticulocytes. 4. The presence of glycine, alanine, and glucose in the suspending medium resulted in no acceleration in the respiration of the cells. At higher concentrations glucose tended to depress the respiration. The material oxidized appears to be mainly or entirely contained in the corpuscles at the time they are liberated from the marrow. 5. A comparison is made of the respiration of the reticulated nucleated red cells present in the blood of anemic fowls and the non-nucleated reticulated red cells of rabbits. On the basis of equal volumes of cells, the respiration of the former is about twice that of the latter, while this in turn is about six times as great as the nucleated but non-reticulated normal red cells of the fowl. PMID- 19872582 TI - THE EFFECT OF SALTS ON THE IONISATION OF GELATIN. AB - The effect of the addition of sodium chloride to gelatin solutions is shown from the Donnan relationship to increase the ionisation of the gelatin, the increase produced in acid solutions reaching a maximum at about 1/1000 molar salt concentration. This effect is attributed to the formation of complex ions. From the similar action of calcium and copper chlorides the effective combining power of gelatin for complex positive ion formation is deduced. The bearing of complex ion formation on the zwitter-ionic structure and solubility phenomena of proteins is pointed out. PMID- 19872583 TI - THE KINETICS OF THE BACTERIUM-BACTERIOPHAGE REACTION. AB - The above data relating to the reaction between 16 hour cultures of S. aureus and antistaphylococcus bacteriophage in nutrient broth of pH 7.6 at 36 degrees C. and with mechanical shaking to maintain a uniform B suspension, bring out the following points: (a) B growth in P-B mixtures does not differ from growth in controls without P except in the case of a very high initial P/B ratio as noted below. There is no evidence that lytic destruction of B begins shortly after mixing P and B nor that B growth is stimulated by P, for the B growth curves in the presence of ordinary [P]'s and in controls are identical. Only at the sudden onset of the rapid lytic process does the B curve of a P-B mixture deviate from the control curve. (b) B growth is an essential conditioning factor for P formation. (c) Both B growth and P production exhibit short lags. During this time P diffuses into or becomes adsorbed to B so rapidly that by the end of the lag period only 10 to 30 per cent of the total P present is extracellular, the remainder being associated with the B. (d) During the logarithmic B growth phase, P formation is also logarithmic but proceeds at a much faster rate. That is, d P/d t is proportional to a power of d B/d t. Consequently the statement that each time a B divides a certain amount of P is formed is not correct. (e) As B growth enters the phase of positive acceleration equilibrium between the extracellular and intracellular P fractions becomes established and is maintained up to the onset of lysis, extracellular [P] representing a small constant percentage of total [P]. The distribution of P on a constant percentage basis suggests the manner in which a relatively simple chemical compound would be distributed and is not at all typical of the distribution one would expect if P were a complex organized parasite. (f) When the value of log P/B = 2.1 lysis begins. Obviously, this limiting value for any initial [B] is reached sooner the higher the initial [P]. When log P/B at the time of mixing P and B is already 2.1 or greater, there is no growth of B and lysis soon occurs. (g) While there is good evidence that lysis is brought about by the attainment of a particular [P] per B and not by a certain [P] per ml., it is not clear at this time which of the ratios intracellular P/B, extracellular P/B or total P/B is the major conditioning factor for B lysis. (h) Experimentally the maximal [P]'s of lysates made by mixing a constant initial [B] with widely varying Po's fall within a relatively narrow range. This fact is explained by the large value of d log P/d t as compared to d log B/d t. That is, the loci of points at which log P = 2.1 + log B (maxima-lysis begins) on the curves of log P against t originating in various [Po]'s will lie at a nearly constant level above the abscissa. Because of this same relationship the maximal [P]'s of such a series will be in the reverse order of magnitude of the Po's, i.e., the larger the Po the smaller will be the maximal [P] attained during the reaction (cf. Fig, 16). (i) The lytic destruction of B is logarithmic with time, in this respect being similar to most death rate processes. The value -d log B/d t for a particular initial [B] is constant for various initial values of [P]. There is good evidence that cells need not be growing in order to undergo lysis. (j) During B lysis a considerable percentage of the total maximal P formed is destroyed, the chief loss probably occurring in the intracellular fraction. The major portion (70 to 90 per cent) of the final P present after the completion of bacteriophagy is set free during the brief phase of bacterial dissolution. (k) When the entire process of bacteriophagy is completed the lysates are left with certain [P]'s determined by the foregone P-B reaction. The destruction of P during lysis is sufficiently regular to maintain the relationship established at the maximal [P]'s. Therefore the final [P]'s have the same points in common that were noted in "h" as applying to the maximal [P]'s. That is, they all are grouped within a narrow range of [P] values, those having been made with high Po's being of lower titre than those made with low initial [P]'s. (1) There is a significant difference in the temperature coefficients of P and B formation. Further, the temperature coefficients of P and B destruction during lysis differ in almost the same ratio. Consequently, while all experimental evidence postulates B growth as an essential conditioning factor for P formation, the temperature coefficient data suggest that the two processes are basically separate reactions. A similar interpretation holds in the case of B dissolution and P inactivation. (m) The major events in the complete process of "bacteriophagy" are mathematically predictable. The [B] at which lysis occurs under certain standard conditions for given values of Bo and Po may be calculated from the equation: See PDF for Equation Substitution of this value for log B in the equation: See PDF for Equation gives satisfactory agreement with observed values for t((lysis)). (n) The kinetic analysis of the P-B reaction predicts that the values of log Po plotted against t((lysis)) for a constant Bo will give a straight line. This plot is employed in a method for the quantitative estimation of P described in an earlier paper on the basis of experimental observation alone. Its use is made more rational by the facts given above. PMID- 19872585 TI - THE KINETICS OF PENETRATION : III. EQUATIONS FOR THE EXCHANGE OF IONS. AB - Equations are given for a variety of cases when ions of the same sign are exchanged between the interior of a living cell and the external solution. PMID- 19872584 TI - ELECTROMETRIC DETERMINATIONS OF THE DISSOCIATION OF GLYCOCOLL AND SIMPLE PEPTIDES. AB - 1. The apparent acid and basic dissociation constants were determined potentiometrically by the methods of hydrolysis and of titration for the following ampholytes: Glycocoll, glycylglycocoll, alanylglycocoll, valylglycocoll, leucylglycocoll, methylleucylglycocoll, phenylalanylglycocoll and glycylglycylglycocoll. The constants were also determined in the presence of KCl and of K(2)SO(4) at equal ionic strength. 2. In general, the relative order of magnitude of the constants decreased as the number of carbon atoms between amino and carboxyl groups increased. An explanation of this is offered on the basis of theories of electronic structure. 3. The application of the modern concepts of solutions to the case of the ampholytic ions is discussed. The inadequacy of the present theories is pointed out. 4. The constants were found, in general, to be functions of the hydrogen ion activity and the ionic strength of the solutions. Apparent contradictions to the Debye-Huckel theory are pointed out and partially explained on the basis of specific ion effects. PMID- 19872586 TI - THE ACCUMULATION OF ELECTROLYTES : II. SUGGESTIONS AS TO THE NATURE OF ACCUMULATION IN VALONIA. AB - It is suggested that K enters chiefly as KOH, whose thermodynamic potential (proportional to the ionic activity product (a(K)) (a(OH))) is greater outside than within. As this difference is maintained by the production of acid in the cell K continues to enter, and reaches a greater concentration inside than outside. KOH combines with a weak organic acid which is exchanged for HCl entering from the sea water (or its anion is exchanged for Cl(-)), so that KCl accumulates in the sap. Na enters more slowly and its internal concentration remains below that of K. The facts indicate that penetration is chiefly in molecular form. As the system is not in equilibrium the suggestion is not susceptible of thermodynamic proof but it is useful in predicting the behavior of K, Na, and NH(4). PMID- 19872587 TI - THE ACCUMULATION OF ELECTROLYTES : III. BEHAVIOR OF SODIUM, POTASSIUM, AND AMMONIUM IN VALONIA. AB - When 0.001 M NH(4)Cl is added to sea water containing Valonia macrophysa there seems to be a rapid penetration of undissociated NH(3) (or NH(4)OH) which raises the pH value of the sap so that the thermodynamic potential of KOH becomes greater inside than outside and in consequence K leaves the cell: NaOH continues to go in because its thermodynamic potential is greater outside than inside. NH(4)Cl accumulates, reaching a much higher concentration inside than outside. This might be explained on the ground that NH(3), after entering, combines with a weak organic acid produced in the cell whose anion is exchanged for the Cl(-) of the sea water, or (more probably) the organic acid is exchanged for HCl. PMID- 19872588 TI - THE ORDER OF DEATH OF ORGANISMS LARGER THAN BACTERIA. AB - In a previous paper it has been shown that the logarithmic order of death of bacteria can be accounted for by the assumption of some very unstable molecules so essential for reproduction that the inactivation of only one such molecule per cell prevents reproduction and makes the cell appear "dead" according to the standard method of counting living bacteria. In the present paper dealing with the order of death of larger organisms, only a motile alga, Chlamydomonas, is shown to have the same order of death. The very scant material on the order of death of yeasts is contradictory. It seems possible that more than one molecule must be destroyed to kill a yeast cell. With the spores of a mold, Botrytis cinerea, the number of "reacting molecules" is decidedly larger than 1. A flagellate, Colpidium, gave a survivor curve suggesting the destruction of two molecules before motility ceases. Erythrocytes exposed to ultra-violet light also follow the formula for two reacting molecules. The analysis of the survivor curves of multicellular organisms is not possible because no distinction between the number of essential molecules and the number of essential cells seems possible. Besides, variability of resistance changes the shape of the survivor curves in such a way that it becomes impossible to differentiate between variability and actual survivor curve. The general results seem to justify the assumption that in each cell, the number of molecules which are really essential for life and reproduction, is quite limited, and that, therefore, equal cells will not react simultaneously, though ultimately the reaction will be the same. This theory of lack of continuity in cell reactions owing to the limited number of reacting molecules is an analogon to the quantum theory where continuity ceases because division of matter reaches a limit. It seems probable that this lack of continuity in cell reactions has a general biological significance reaching beyond the order of death. PMID- 19872589 TI - A METHOD FOR DETERMINING THE OXYGEN CONSUMPTION OF A SINGLE CELL. AB - 1. A method for measuring the O(2) consumption of a single cell is described. The cell is placed in a capillary tube adjacent to a bubble of air. KOH (5 per cent) is drawn in on the opposite side of the air and both ends of the tube are sealed with mineral oil. The decrease in the volume of the gas, representing the O(2) consumed, is followed. 2. The possible errors of the technique are appraised. 3. A single Actinosphaerium eichhornii consumes 0.00113 mm.(3) of O(2) per hour. A single Paramecium caudatum consumes 0.00049 mm.(3) of O(2) per hour. 4. The significance of the results and the limitations of the method are discussed. PMID- 19872590 TI - THE CONDITIONS OF RECOVERY OF TRANSMISSIVITY OF NEWLY REPASSIVATED IRON WIRES IN NITRIC ACID. AB - 1. Passive steel wires were activated in a bath (Bath A) containing 70 v. per cent HNO(3) (in which they undergo prompt repassivation), and immediately transferred to a second bath (Bath B) containing HNO(3) of a concentration varying in different experiments. After varying intervals in this bath they were transferred while still passive to a third bath (Bath C) containing strong HNO(3) (70 or 100 v. per cent) and there immediately activated. 2. During the immersion in Bath B the wires progressively recover their ability to transmit activation waves in strong HNO(3). The measure of this recovery is the distance travelled by the activation waves in Bath C after the varying times of exposure in Bath B. Transmissivity as thus measured is at first incomplete (decremental) and later becomes complete. The minimal exposures in Bath B required to render wires completely transmissive in the strong acid of Bath C were determined for concentrations of HNO(3) between 10 and 100 v. per cent. With 100 v. per cent HNO(3) in Bath C, these exposures range from 40 minutes or more in 15 v. per cent to 10 minutes in 100 v. per cent HNO(3) (temperature 19-20 degrees in all baths). 3. The time required for complete recovery varies inversely with the concentration of the acid in the recovery bath (Bath B), but increases rapidly with the concentration of the acid in the testing bath (Bath C). Hence at a time when a wire has recovered just sufficiently to transmit non-decrementally in a given strong acid (e.g., 70 v. per cent) it still transmits decrementally in a stronger acid. Complete recovery for transmission in 100 v. per cent HNO(3) requires about twice as long as for 70 v. per cent HNO(3). In HNO(3) of 50 v. per cent and less decremental transmission does not occur. 4. The indications are that recovery is an effect of the progressive solvent action of the external acid on the passivating oxide film, which at its first deposition appears to be relatively thick and hence resistant to electrochemical reduction. The final stage of recovery, when electrical sensitivity and speed of transmission are maximal, would on this hypothesis correspond to minimal thickness, possibly monomolecular. 5. The rate of recovery in Bath B is not far from proportional to the concentration of HNO(3) in the more dilute solutions, but in the higher, especially the strongly passivating, concentrations (70 to 100 v. per cent) the rate becomes appreciably slower than proportional, apparently because of the intense oxidizing action of these solutions, which reinforces the oxide sheet and retards the thinning process. 6. The bearing of these observations on the problem of the conditions of recovery in irritable living tissues (such as nerve) during the absolute and relative refractory periods is briefly discussed. PMID- 19872591 TI - THE CAMBIUM AND ITS DERIVATIVE TISSUES : VI. THE EFFECTS OF HYDROGEN ION CONCENTRATION IN VITAL STAINING. AB - It should be emphasized, in conclusion, that the writers' investigation is a reconnaissance, and was initiated primarily in searching for more adequate techniques for the study of cytological problems. Crude as many of the data undoubtedly are, they are of some significance in outlining future trends of more intensive investigation. The occurrence of two distinct types of vacuoles within the same cell provides a valuable check upon generalizations concerning the penetration of certain dyes. The A-type vacuole affords a means of determining that a number of dyes do penetrate living plant cells readily and rapidly from acid buffers. The recognition of two distinct categories of vacuoles-which are widely distributed throughout the higher plants-and a study of their staining reactions in Group I, Group II, and Group III dyes, indicate that certain discrepancies in the literature are due to the fact that different investigators are concerned with different vacuoles and with different dyes. For an accurate visualization of the physico-chemical mechanisms of the penetration and accumulation of dyes in living cells a much wider range of reliable data is essential, both as regards the purely biological variables and the physico chemical variables in techniques employed in their investigation. Until such data are available, generalizations from limited induction should be reduced to a minimum. PMID- 19872592 TI - THE DEATH WAVE IN NITELLA : III. TRANSMISSION. AB - Cutting a cell of Nitella sets up a series of rapid electrical responses, transmitted at a rate too rapid to be measured by means of our records. These are followed by slower responses whose speed falls off as the distance from the cut increases, as though they were caused by a mechanical disturbance whose intensity falls off as it travels. The faster responses seem to be due to the motion of sap past protoplasmic surfaces which have suffered little or no alteration (they seem to be similar to the electrical changes following a blow on the end of a soft rubber tube containing Ag-AgCl electrodes). The slower responses appear to be due to alterations in the protoplasm and are usually irreversible. PMID- 19872593 TI - THE OSMOTIC PROPERTIES OF LIVING CELLS (EGGS OF ARBACIA PUNCTULATA). AB - WE HAVE ATTEMPTED TO ANSWER THE QUESTION: How nearly ideal, as an osmometer, is the unfertilized Arbacia egg? The following conclusion have been reached: 1. Volumes can be measured accurately over a wide range of pressures since the cell is in general spherical and does not suffer deformation from its own weight or other factors. 2. The product of volume and pressure is approximately constant, if allowance be made for osmotically inactive cell contents. It is computed that from 7 to 14 per cent of cell volume is occupied by osmotically inactive material. 3. Evidence is presented that no appreciable escape of cell contents occurs while the cell is in hypotonic sea water; that, therefore, the semipermeability of the membrane is approximately perfect, so long as injury to the cell is avoided. 4. In comparison with osmotic pressure the influence of other forces, such as elasticity or surface tension, on cell volume must in these experiments be slight. PMID- 19872594 TI - FURTHER STUDIES ON THE KINETICS OF OSMOSIS IN LIVING CELLS. AB - Using unfertilized eggs of Arbacia punctulata as natural osmometers an attempt has been made to account for the course of swelling and shrinking of these cells in anisotonic solutions by means of the laws governing osmosis and diffusion. The method employed has been to compute permeability of the cell to water, as measured by the rate of volume change per unit of cell surface per unit of osmotic pressure outstanding between the cell and its medium. Permeability to water as here defined and as somewhat differently defined by Northrop is approximately constant during swelling and shrinking, at least for the first several minutes of these processes. Permeability is found to be independent of the osmotic pressure of the solution in which cells are swelling. Water is found to leave cells more readily than it enters, that is, permeability is greater during exosmosis than during endosmosis. PMID- 19872595 TI - ON THE TEMPERATURE CHARACTERISTICS FOR FREQUENCY OF BREATHING MOVEMENTS IN INBRED STRAINS OF MICE AND IN THEIR HYBRID OFFSPRING. I. AB - Young mice of a selected line of the dilute brown strain of mice exhibit over the range 15-25 degrees C. (body temperature) a relation of frequency of breathing movements to temperature such that when fitted by the Arrhenius equation the data give a value for the constant micro of 24,000+/- calories or, less frequently, 28,000+/-. Young mice of an inbred albino strain show over the range 15-20 degrees C. a value of micro = 34,000+/-, or, less frequently, 14,000+/-, with a critical temperature at about 20 degrees C. and a value of micro = 14,000+/- above 20 degrees C. The F(1) hybrids of these two strains, and the backcross generations to either parent strain, exhibit only those four values of the temperature characteristic observed in the parent strains and none other. One may therefore speak of the inheritance of the value of the constant micro, but the inheritance shows in this instance no Mendelian behavior. Furthermore there appears to be inherited the occurrence (or absence) of a critical temperature at 20 degrees C. These experiments indicate the "biological reality" of the temperature characteristics. PMID- 19872596 TI - THE PHYSIOLOGICAL PRINCIPLE OF MINIMUM WORK : A REPLY. PMID- 19872597 TI - ON CHROMOSOME BALANCE AS A FACTOR IN DURATION OF LIFE. AB - This paper presents a study of the influence of chromosome balance on duration of life in Drosophila. The balanced type of cells are shown to favor a longer life than are the unbalanced type. Under the identical conditions of the experiment, the type females live an average of 33.1+/-.6 days; the type males 28.9+/-.8 days; the triploid females 33.1+/-.8 days and the sex-intergrade females 15.0+/ .3 days. The unbalance of the chromosomes and therefore of the genes contained within them is evidently a fundamental factor in the probable life span of the individual. The magnitude of the effect is fully on a par with that found for other factors, i.e., different Mendelian genes for constitutional vigor, etc. It has been possible to show by a study of the various sex classifications within the sex-intergrade class that the presence or absence of ovarian or testicular tissue as such is not the primary cause of the difference in the life duration in the type males and females but that the cause is to be found deeper, sex determination and duration of life accompanying each other and resulting from the common cause, chromosome constitution. The survival curve of the sex-intergrade groups present a limiting curve of duration of life, a constant death rate for each day of age. The curves have different rates of degeneration. To account for this fact it is necessary to assume that for these particular organisms a different organ in the two groups has assumed major significance to life due to the gene complex which causes their differentiation. Recurrent chance environmental and hereditary agents acting on organs generate the type of probability curve observed. Triploid flies are made up of cells which are one third larger than the cells of the type flies. It is not without significance to note that such individuals show no greater or less duration of life than do the ordinary flies when both groups have their chromosomes in balance. PMID- 19872598 TI - METABOLISM AS RELATED TO CHROMOSOME STRUCTURE AND THE DURATION OF LIFE. AB - This paper presents the rates of CO(2) production for four groups of Drosophila which differ in their chromosome constitutions. The four groups have metabolic rates which correlate with the balance of their chromosomes, the balanced chromosome groups of flies producing less CO(2) than the unbalanced chromosome groups. It is concluded therefore that genic balance plays a prominent part in metabolic control. The carbon dioxide rates are related to the duration of life within these groups. The results show that qualitatively the larger the production of CO(2) per day the shorter the time which the flies are capable of living. The agreement is not exact quantitatively. Rubner's theory postulating a limit for the energy an organism is capable of metabolizing does not hold for the six classes of flies. The data show that the theory can be at most not more than a partial truth. Cell size is found to show no direct correlation with the metabolic rates of the different fly cohorts. PMID- 19872599 TI - ELECTRICAL VARIATIONS DUE TO MECHANICAL TRANSMISSION OF STIMULI. AB - Mechanical stimulation of Nitella often produces responses resembling propagated negative variations but traveling faster and going past a killed spot. They appear to result from a mechanical disturbance traveling along the cell and stimulating each spot it touches (i.e. the stimulus itself travels). They are called mechanical variations to distinguish them from propagated negative variations. A mechanical disturbance may cause an irreversible change (death wave), but in traveling along the cell it may lose intensity and then produce only a reversible response (mechanical variation) which may eventually change to a propagated negative variation. The all or none law does not apply to incomplete mechanical variations, for the response varies with the strength of the stimulus. PMID- 19872600 TI - A METHOD FOR THE RAPID DIALYSIS OF LARGE VOLUMES OF PROTEIN SOLUTIONS. AB - A method is described by which moderately large quantities of protein solutions can be dialyzed relatively free of salts within 12 to 24 hours. The use of "Visking" tubes instead of collodion bags is recommended, for speed of dialysis as well as ease of manipulation. PMID- 19872601 TI - THE SORPTION OF BACTERIOPHAGE BY LIVING AND DEAD SUSCEPTIBLE BACTERIA : I. EQUILIBRIUM CONDITIONS. AB - The above data relating to the antistaphylococcus phage and single strain of S. aureus with which previous papers have been concerned (9, 10, 11, 12), bring out the following points. (a) For live, resting, susceptible B suspended in broth as well as for B in a P-B mixture during the logarithmic phases of B growth and P formation, P is distributed in a manner typical of numerous materials soluble in both phases of a two phase system, i.e., distribution proceeds in accordance with the equation C(b)/C(a) = K where C(b) = extracellular P/ml. of broth and C(a) = intracellular P/ml. of B. The combination is quantitatively reversible. (b) With heat-killed, susceptible B, P distribution is of the adsorptive type, expressible in the form of the adsorption isotherm equation a = kC(1/n). The average value of 1/n is 0.80 in agreement with the results of von Angerer (2). Under ordinary conditions dead B take up much more P than do live B, the reaction proceeding to > 99 per cent completion. The combination of P with dead B is not demonstrably reversible and with high initial P/B ratios saturation of B with P is effected. Bacteria killed at 65 degrees C., 80 degrees C. and 100 degrees C. show no differences in adsorptive ability. (c) The rates at which live, resting, susceptible B and heat-killed, susceptible B remove P from solution do not differ significantly. Velocity constants of the process calculated from See PDF for Equation agree satisfactorily. It is shown that the time interval consumed is concerned with an actual reaction between P and B and not with diffusion of P through the broth to B. (d) P determinations have been found to serve as satisfactory indicators for B growth in P-B mixtures where [B] is to be maintained at a constant level. Very small increments in [B] give rise to measurable increases in P by virtue of the fact that dP/dt is proportional to a power of the rate dB/dt (9). (e) Similarly [P] estimations will detect death of B cells in P-live B suspensions. Dead B take up large amounts of P irreversibly; such P cannot function in the titration and the result is a sharp drop in [P] of controls. PMID- 19872602 TI - ON THE THEORY OF NERVOUS CONDUCTION. AB - Assuming that the propagation of the nervous impulse consists in the excitation of adjacent regions of the nerve by the action current of the already excited region, exact equations for the velocity of such a propagation are established and integrated. The result depends on the assumptions which we make about the laws of excitation. If Hoorweg's law is accepted, it is found that the velocity of propagation decreases exponentially with time, and that there is a limiting distance which the impulse will travel and which cannot be exceeded. If however a set of equations proposed by L. Lapique is assumed to govern the process of excitation, we find that the velocity of propagation asymptotically reaches a constant value. PMID- 19872603 TI - THE ANALYSIS OF BIOLUMINESCENCES OF SHORT DURATION, RECORDED WITH PHOTOELECTRIC CELL AND STRING GALVANOMETER. AB - 1. The rapid decay of luminescence in extracts of the ostracod crustacean Cypridina hilgendorfii, has been studied by means of a photoelectric-amplifier string galvanometer recording system. 2. For rapid flashes of luminescence, the decay is logarithmic if ratio of luciferin to luciferase is small; logarithmic plus an initial flash, if ratio of luciferin to luciferase is greater than five. The logarithmic plot of luminescence intensity against time is concave to time axis if ratio of luciferin to luciferase is very large. 3. The velocity constant of rapid flashes of luminescence is approximately proportional to enzyme concentration, is independent of luciferin concentration, and varies approximately inversely as the square root of the total luciferin (luciferin + oxyluciferin) concentration. For large total luciferin concentrations, the velocity constant is almost independent of the total luciferin. 4. The variation of velocity constant with total luciferin concentration (luciferin + oxyluciferin) and its independence of luciferin concentration is explained by assuming that light intensity is a measure of the luciferin molecules which become activated to oxidize (accompanied with luminescence) by adsorption on luciferase. The adsorption equilibrium is the same for luciferin and oxyluciferin and determines the velocity constant. PMID- 19872604 TI - DETACHMENT OF BACTERIOPHAGE FROM ITS CARRIER PARTICLES. AB - The active substance (phage) present in the lytic broth filtrate is distributed through the medium in the form of particles. These particles vary in size within broad limits. The average size of these particles as calculated on the basis of the rate of diffusion approximates 4.4 mmicro in radius. Fractionation by means of ultrafiltration permits partial separation of particles of different sizes. Under conditions of experiments here reported the particles varied in the radius size from 0.6 mmicro to 11.4 mmicro. The active agent apparently is not intimately identified with these particles. It is merely carried by them by adsorption, and under suitable experimental conditions it can be detached from the larger particles and redistributed on smaller particles of the medium. PMID- 19872605 TI - ELECTROKINETIC PHENOMENA : IV. A COMPARISON OF ELECTROPHORETIC AND STREAMING POTENTIALS. AB - 1. The conditions are described which are necessary for the comparison of certain types of electrokinetic potentials. An experimental comparison is made of (a) electrophoresis of quartz particles covered with egg albumin; and (b) similar experiments by Briggs on streaming potentials. A slight, consistent, difference is found between the electrophoretic potential and the streaming potential. This difference is probably due to the difference in the protein preparations used rather than to real difference in the electrophoretic and streaming potentials. 2. Data are given which facilitate the measurements and enhance the precision of the estimation of electrical mobilities of microscopic particles. PMID- 19872606 TI - DISTRIBUTION OF HYDROCHLORIC ACID IN GELATINE GELS. PMID- 19872607 TI - THE OCCURRENCE OF PORPHYRINS IN CULTURES OF C. DIPHTHERIAE. AB - A complex porphyrin which has not been hitherto described is found in liquid cultures of C. diphtheriae. The porphyrin is a combination of coproporphyrin with both iron and copper, and shows an oxidation-reduction change. This is the first report, as far as we are able to determine, of a porphyrin compound which contains both iron and copper in its molecule. Its source is in all probability the cytochome of the bacilli. The content of porphyrin is proportional to the biological titer of the culture filtrate; the suggestion is offered that the toxin itself is derived from cytochrome. PMID- 19872608 TI - PROTEIN COAGULATION AND ITS REVERSAL : THE IDENTITY OF NORMAL HEMOGLOBIN WITH THE HEMOGLOBIN PREPARED BY THE REVERSAL OF COAGULATION, AS DETERMINED BY SOLUBILITY TESTS. AB - 1. Methemoglobin prepared from coagulated hemoglobin by the reversal of coagulation has the same solubility within 2 per cent as normal methemoglobin. 2. Methemoglobin synthesized from hemin and the native globin prepared by the reversal of coagulation of globin likewise has the same solubility as normal methemoglobin. PMID- 19872609 TI - PROTEIN COAGULATION AND ITS REVERSAL : GLOBIN. AB - 1. The globin prepared from hemoglobin by the acid acetone method is denatured globin. 2. The denaturation and coagulation of globin by acid acetone are reversible. 3. Soluble globin can be obtained from the acid acetone globin even if the globin is first precipitated by trichloracetic acid or heated to 100 degrees C. 4. Hill and Holden's theory that they separated native globin from hemoglobin without any intermediate denaturation is not proven by their experiments. PMID- 19872610 TI - THE PRODUCTION AND INHIBITION OF ACTION CURRENTS BY ALCOHOL. AB - Suitable concentrations of ethyl alcohol (1 to 1.5 M) applied to a spot on a cell of Nitella lower the P.D. enough to cause action currents. The alcohol then suppresses action currents arriving from other parts of the cell and acts as a block. After the alcohol is removed the normal P.D. and irritability return. Similar experiments on the sciatic nerve and skin of the frog produced only a negative result. PMID- 19872611 TI - TEMPERATURE CHARACTERISTIC FOR PRODUCTION OF CO(2) BY PHASEOLUS SEEDLINGS. AB - The temperature characteristic for respiratory production of CO(2) by young seedlings of Phaseolus aureus (Roxb.) is micro = 16,500 calories, 12-21 degrees C., even when the analyses depend upon the use of many seedlings crowded in a small respiration chamber, provided reasonable precautions are taken to avoid injury and to permit proper thermal adaptation. There is evidence of a definite critical temperature at 20-21 degrees . These findings agree quantitatively with those obtained with other similar seedlings, and contradict the results reported by Kurbatov and Leonov (1930); the reasons for this are analysed. PMID- 19872612 TI - TEMPERATURE CHARACTERISTICS FOR THE OXYGEN CONSUMPTION OF GERMINATING SEEDS OF LUPINUS ALBUS AND ZEA MAYS. AB - The rate of oxygen consumption by germinating seeds of Lupinus albus and of Zea mays was studied as a function of temperature (7-26 degrees C.). The Warburg manometer technique was used, with slight modifications. Above and below a critical temperature at 19.5 degrees C. the temperature characteristic for oxygen consumption by Lupinus albus was found to be micro = 11,700+/- and 16,600 respectively. The same critical temperature was encountered in the case of Zea mays, with temperature characteristics micro = 13,100+/- above and micro = 21,050 below that temperature. PMID- 19872613 TI - THE FLOCCULATION OF GELATIN AT THE ISOELECTRIC POINT. AB - The results of this investigation show that a gelatin solution consists of a considerable number of constituents. At a particular temperature, certain gelatin constituents tend to aggregate and to flocculate from solution. When these particular gelatin constituents have completely flocculated, no further change occurs in the system and an apparent equilibrium exists. This is not a dynamic equilibrium between the gelatin flocculate as a whole and the gelatin remaining in the solution but a steady state determined for that system by the temperature. It is also shown that gelatin can be separated into fractions in which the gelatin constituents are more nearly uniform and tend to flocculate over a much narrower temperature range. It should be possible to obtain a number of fractions in which all of the gelatin would flocculate at a definite temperature. The aggregation of the various gelatin constituents is presumably due to loss of thermal energy, and the temperature at which this occurs must be some function of the mass of the constituent. It is natural to assume, then, that the constituents which flocculate at a given temperature are larger than those which remain in solution at that temperature. Recently, Krishnamurti and Svedberg (1930) have obtained evidence with the ultra-centrifuge that the constituents of a gelatin solution are heterogeneous as to mass, even at a pH value at which there is no tendency toward aggregation. There is much reason to suppose that the gelatin constituents do not differ very greatly chemically since different fractions have the same refractive index and the same isoelectric point. The data as a whole are best explained by considering the gelatin constituents to be different degrees of association of the same or very similar molecular structural units. This is in agreement with Sheppard and Houck (1930), who consider that "the molecules of gelatin are fundamentally identical with those of collagen, the difference being only in the degree of association and orientation". Meyer and Mark (1928) have interpreted the x-ray data obtained from collagen as indicating that the micelles of the collagen fiber are built up of main valency chains of anhydro-amino acids. It may be supposed that during peptization of these fibers, the amino acid chains become separated, disorientated, and partially broken up, so producing the heterogeneous system which we know as gelatin. It is evident that the manner in which this breaking-up proceeds depends upon the chemical treatment previous to the peptization process and the gelatin produced from lime-treated collagen would be expected to differ from that from acid-treated collagen. From the results herein reported it seems evident that the technique of isoelectric flocculation of electrolyte-free gelatin offers a profitable method for the study of gelatin and an extended investigation along these lines should yield much valuable information concerning the nature of gelatin. It is possible that this method may also be extended to other hydrophilic colloids. PMID- 19872614 TI - THE VAPOUR PRESSURES OF AQUEOUS SOLUTIONS WITH SPECIAL REFERENCE TO THE PROBLEM OF THE STATE OF WATER IN BIOLOGICAL FLUIDS. AB - DATA FOR THE DEPRESSION OF VAPOUR PRESSURE ARE PRESENTED FOR THE FOLLOWING AQUEOUS SOLUTIONS: NaCl (0.03 to 0.1 molar), KCl (0.03 to 0.1 molar), urea (0.05 to 0.5 molar), sucrose (0.05 to 0.10 molar), lactic and succinic acids, creatine, CaCl(2) (0.05 molar), and mixtures of these substances with one another and with certain other solutions (gelatin, gum acacia, sea water, LiCl, etc.). The relation of the depression of vapour pressure of a mixed solution to that of solutions of the individual constituents was investigated in order to ascertain to what extent such studies may be used for the determination of the degree of hydration, or of the state of water, in solutions. Organic substances (urea, sucrose, etc.) showed anomalous results which were markedly affected and unpredictable in mixed solutions. They are, therefore, unsuited for the study of water binding. In the case of solutions of inorganic substances-LiCl and CaCl(2) the principle of the additive nature of colligative properties is also only approximately true-except perhaps in very dilute solutions. The limitations of the colligative method for determining the degree of hydration have been defined in accord with the above findings. Studies of the vapour pressures of mixtures of gelatin or gum acacia with NaCl or KCl demonstrated that hydration in gelatin is relatively small at pH = 7 and undetectable in gum acacia solutions. The view, therefore, that hydrophilic colloids are strongly hydrated has not been substantiated. The passage from the sol to the gel state also was not accompanied in gelatin or in blood by any appreciable change in the degree of hydration of the hydrophilic colloids present in these substances. PMID- 19872615 TI - THE ISOELECTRIC POINT OF A STANDARD GELATIN PREPARATION. AB - Two samples of a standard gelatin were studied, both prepared according to published specifications and washed free from diffusible electrolytes. The isoelectric point of this material was determined in four ways. 1. The pH values of solutions of gelatin in water approached the limit 4.86 +/- 0.01 as the concentration of gelatin was increased. 2. The pH values of acetate buffers were unchanged by the addition of gelatin only at pH 4.85 +/- 0.01. This gives the isoionic point of Sorensen, which is the isoelectric point with respect only to hydrogen and hydroxyl ions. 3. Gels of this gelatin made up in dilute HCl or NaOH, or in dilute acetate buffers, exhibited maximum turbidity at pH 4.85 +/- 0.03. 4. Very dilute suspensions of collodion particles in 0.1 per cent gelatin solutions made up in acetate buffers showed zero velocity in cataphoresis experiments only at pH 4.80 +/- 0.01. No evidence was found for the assumption that gelatin has two isoelectric points at widely separated pH values. It is concluded that the isoelectric point of this standard gelatin is not far from pH 4.85. PMID- 19872616 TI - THE PHOTOTROPIC SENSITIVITY OF PHYCOMYCES AS RELATED TO WAVE-LENGTH. AB - Under the circumstances of experimentation described, the sporangiophores of Phycomyces are found to be most sensitive to stimulation by light in the violet between 400 and 430 mmicro. Toward the red, sensitivity falls to nearly zero near 580 mmicro, while in the near ultra-violet around 370 mmicro, sensitivity is still high. The previous experiments of Blaauw had placed the point of greatest sensitivity some 80 mmicro nearer the red end of the spectrum. Because of the known presence in the sporangiophores of Phycomyces of "accessory" pigments, care must be taken in identifying such results with the absorption spectrum of the photosensitive substance. PMID- 19872617 TI - CRYSTALLINE PEPSIN : III. PREPARATION OF ACTIVE CRYSTALLINE PEPSIN FROM INACTIVE DENATURED PEPSIN. AB - 1. Pepsin solutions which have been completely denatured and inactivated by adjusting to pH 10.5 recover some of their activity when titrated to about pH 5.4 and allowed to stand at 22 degrees C. for 24 to 48 hours. 2. Control experiments show that this inactivation and reactivation are probably not due to the effect of any inhibiting substance. 3. A method of isolation of the reactivated material has been worked out. 4. The reactivated material recovered in this way is a protein with the same general solubility, the same crystalline form, and the same specific proteolytic activity as the original crystalline pepsin. 5. This furnishes additional proof that the proteolytic activity is a property of the protein molecule. PMID- 19872618 TI - PROTEIN COAGULATION AND ITS REVERSAL : SERUM ALBUMIN. AB - 1. It is possible to prepare crystalline, soluble, heat-coagulable serum albumin from coagulated serum albumin. 2. In the cases so far studied, the more soluble a denatured protein, the more easily its denaturation can be reversed. PMID- 19872619 TI - THE DEFORMABILITY AND THE WETTING PROPERTIES OF LEUCOCYTES AND ERYTHROCYTES. AB - The resistance to deformation of polymorphonuclear neutrophile leucocytes under the conditions of our observations has been shown to be on the average considerably less than the resistance to deformation of large mononuclear leucocytes. It is recognized of course that the viscosity of leucocytes, as of other cells, may be markedly influenced by osmotic conditions (17), by the reaction of the suspending medium (18, 19), by temperature, or by injury (20, 21). Although the conditions of our observations were quite different from those of the body, they were nevertheless closely similar to those of simultaneous phagocytosis experiments in which the cells functioned exceedingly well (3). Moreover E. R. and E. L. Clark (22) have noted that polymorphonuclear leucocytes in the tails of living tadpoles were more fluid than the macrophages. And Goss (23) in microdissecting human polymorphonuclear neutrophiles reports that they are more fluid than the clasmatocytes and monocytes studied by Chambers and Borquist (24). Other types of leucocytes have in our experience seemed to fall between the large mononuclear and the polymorphonuclear leucocytes in their average resistance to the interfacial tensions. The leucocyte of each type studied is surrounded by an exceedingly delicate membrane. This membrane appears under the dark-field microscope as a pale, silvery line not distinguishable by inspection alone from a simple phase boundary between two immiscible liquids. That this is a membrane, however, and not a mere interface between immiscible phases, seems certain. In the first place the cell cytoplasm and the suspending medium are not immiscible. When the cell organization is broken down by the interfacial tension the greater part of the cell contents is immediately dissolved or dispersed. Goss (23) has noted that when the membrane is torn with a microdissection needle disintegration at once spreads over the membrane and the cytoplasm undergoes profound change. Moreover it is improbable that a simple phase boundary could exist in the presence of so much protein, lipoid, and other surface active materials as are present in protoplasm; the tendency of these substances to lower the free interfacial energy must necessarily tend to their adsorption in the interface until, if sufficient material is available at the interface, an adsorption film or membrane may be formed. Kite (25), in a pioneer microdissection study, described the polymorphonuclear leucocyte as "naked" protoplasm. The contradiction between this statement and those just made is more apparent than real. For the capacity swiftly to form a limiting membrane between itself and other liquids is an attribute of "naked" protoplasm, as has been shown by the beautiful experiments of Chambers (20). The present study of the wetting properties of leucocytes shows that their external membranes are hydrophilic, a character suggesting a surface in which proteins, probably bound water and salts (27), possibly the polar radicles of soaps or fatty acids, rather than non-polar lipoid groupings, are predominantly exposed. This makes it the more remarkable that a cell of such fluidity as for instance the polymorphonuclear leucocyte, composed largely of water and of water-soluble materials, should maintain its integrity in an aqueous medium with the aid of a membrane so delicate and so mobile. The mobility of the membrane, frequently extended in forming new pseudopodia or spreading over the surface of particles being ingested, must require constant entrance into and exit from the membrane of component materials, and their constant reorganization there. The limiting factors in the reformation of such a membrane would be the amounts of adsorbable materials available and their rates of movement up to the surface rather than the time required for orientation there, since the latter phenomenon is exceedingly rapid. Harkins (29), for instance has calculated that at a water-water vapor interface at 20 degrees C., from the area occupied by one molecule of water, a molecule would jump out into the vapor and a vapor molecule would fall into this area of the surface 7,000,000 times in one second; the time of orientation of the water molecule he estimates to be of the order of 1/100,000,000 second or less. The mammalian erythrocyte possesses a surface membrane capable of being folded and of withstanding tension in the interface. This has also been stretched by microdissection needles (21). The surface of the erythrocyte, as evidenced by its wetting properties, is relatively hydrophobic, relatively non-polar in character, as compared with the leucocyte. Evidence indicating that the erythrocyte surface contains both lipoid and protein components has been summarized in earlier papers (8, 30). We have little to add here other than to point out that the wetting properties of the chicken erythrocyte surface are similar to those fully described for the mammal. A serious source of error in certain isoelectric point determinations is discussed. PMID- 19872620 TI - SALT EFFECTS ON EGGS AND NAUPLII OF ARTEMIA SALINA L. AB - Eggs of Artemia salina L., the brine shrimp, are easily obtainable in large quantities. Ecdysis takes place in two stages: (a) extrusion of the inner membrane, and (b) ecdysis of the nauplius from that membrane. The conditions which allow for the former are much more varied than those for the latter. Nauplii form in only solutions of a few sodium salts; and, in Mg, Ca, and Sr salts, potassium is very toxic. The possible environment for the nauplii (1 M total molarity) has been ascertained for chlorides of Na, K, Mg, and Ca. The facts observed account for the peculiar distribution of the organism. PMID- 19872621 TI - SALT EFFECTS ON SWARMERS OF DUNALIELLA VIRIDIS TEOD. AB - 1. Dunaliella viridis Teodoresco thrives equally well in solutions of NaCl 1 to 4 mol and pH 6 to 9. 2. The organism is sensitive to calcium and magnesium, especially in acid medium. 3. Calcium and magnesium are antagonistic. In a molar solution of NaCl the antagonistic relation Mg:Ca is 4 to 5. In a 4 molar solution of NaCl the proportion becomes many times as great (20:1). 4. Although the strains used in this investigation did not occur in sea water concentrates, the increase in the antagonistic ratio Mg:Ca in which they can live closely paralleled the changes in this ratio which take place when sea water evaporates. 5. The other organisms which occurred in the cultures each show a specific relation to Ca and Mg. 6. The size of the cells of Dunaliella does not decrease with increasing NaCl content. PMID- 19872622 TI - A VISCOSIMETRIC METHOD OF ESTIMATING ENZYME CONCENTRATION WITH SPECIAL REFERENCE TO AMYLASE. AB - Certain technical modifications of the viscosimetric methods as first employed by Northrop and Hussey have been presented. Most of these have been employed with satisfactory results in the irradiation studies of Hussey and Thompson over a period of several years. These are in turn applied to a method of estimation of amylase concentration. PMID- 19872623 TI - THE INSENSITIVITY OF PARAMECIUM TO CYANIDE AND EFFECTS OF IRON ON RESPIRATION. AB - 1. The effects of KCN and iron salts on oxygen consumption has been studied in the cell of Paramecium caudatum by manometric methods. 2. KCN solutions of strengths from M/200 to M/10,000 have been shown to produce no decrease in oxygen consumption, but have in most cases produced a very slight increase in the respiration rate. 3. The pH values were found to have little or no effect on these results. 4. Iron salts produce either no effect or a great diminution of oxygen consumption, in no case causing stimulation of rates of respiration. 5. Iron salts in neutral solutions do not penetrate the Paramecium cell nor do they cause so marked an effect as in an acid state. 6. The iron-content of Paramecium was found to be extremely small and not demonstrable by delicate tests. It is believed that iron is not combined in the cell in the form of a respiration catalyst sensitive to cyanide. PMID- 19872624 TI - GEOTROPIC EXCITATION IN HELIX. AB - Rotation of an inclined surface on which Helix is creeping straight upward, such that the axis of the animal is turned at a right angle to its previous position, but in the same plane, leads to negatively geotropic orientation after a measurable latent period or reaction time. The duration of the latent period is a function of the slope of the surface. The magnitude of the standard deviation of the mean latent period is directly proportional to the mean latent period itself, so that the relative variability of response is constant. The dependence of reaction time upon extent of displacement from symmetrical orientation in the gravitational field is found also by tilting the supporting surface, without rotation in the animal's own plane. On slopes up to 55 degrees , the relation between latent period and the sine of the slope is hyperbolic; above this inclination, the latent period sharply declines. This change in the curve is not affected by the attachment of moderate loads to the snail's shell (up to 1/3 of its own mass), and is probably a consequence of loss of passive stable equilibrium when rotated. When added loads do not too greatly extend the snail's anterior musculature, the latent period for the geotropic reaction is decreased, and, proportionately, its sigma. These facts are discussed from the standpoint that geotropic excitation in these gasteropods is due to impressed muscle tensions. PMID- 19872625 TI - THE PRESENCE OF A GELATIN-LIQUEFYING ENZYME IN CRUDE PEPSIN PREPARATIONS. AB - A protein fraction has been isolated from crude pepsin preparations which is about 400 times as active as crystalline pepsin in the lique-faction of gelatin. The activity as measured by the digestion of casein, edestin or egg albumin is less than that of crystalline pepsin. It is more resistant to alkali than the crystalline pepsin. PMID- 19872626 TI - STUDIES ON MILK SECRETION : THE INFLUENCE OF INANITION. AB - In this paper data are presented on cows receiving no food but having access to all of the water which they wished. The yield and composition of the milk were determined at various times during the periods of starvation. The composition of the milk showed changes which were progressive in the sense that they followed a definite course. They were characterized by a marked lowering in the amount of milk produced, by an increase in the total solids (chiefly an increase in the percentage of fat and ash, with a slight increase in proteins), and by a pronounced decrease in the lactose. The decrease in lactose corresponded with a decrease in the dextrose content of the blood, thereby supporting the conclusion that the lactose of milk has as its precursor dextrose of the blood. All the changes in milk composition during starvation can be directly related to the simultaneous changes in the blood. The following companion paper on insulin and phloridzin as they affect milk secretion further develops these hypotheses. PMID- 19872627 TI - ON THE MECHANISM OF MILK SECRETION : THE INFLUENCE OF INSULIN AND PHLORIDZIN. AB - The four types of experiments on milk secretion herein described really fall into one general class so far as the physiological effects produced are concerned. Starvation lowers the blood sugar and raises the osmotic pressure of the blood. The experiment using parathyroid hormone with or without starvation may have its effects interpreted as simply due to starvation since 1000 units of this hormone produced no visible effects on the blood calcium or milk constituents different from those of starvation. Since insulin produces a marked and rapid drop in blood sugar it too may be looked upon as a rapid starvation effect. It has some other important effects, however. Briggs et al. (21) have shown that potassium and phosphorus of the blood are decreased and Luck, Morrison, and Wilbur (22) indicate a reduction in the amino acids of the blood in insulin treatment. Phloridzin lowers the threshold for sugar retention with the consequence that in time it tends to lower the sugar of the blood to an even greater extent than that noted in starvation. It tends to depress the potassium, to increase the phosphorus content of the blood, and to cause the body to burn protein rather than carbohydrate, thus increasing nitrogen excretion. All of the experiments are characterized by a sharp reduction in the milk yield. Cary and Meigs (23) have studied like reductions in milk yield produced by varying the energy or protein of the diet. They conclude that such decrease in milk production may be interpreted as due to the direct effect of the starvation and the consequent reduction of the energy and protein available to milk secretion. The reduction in milk yield for the experiments herein described can undoubtedly be attributed to the same causes as those cited by Cary and Meigs. The experiment where Cow 47 was given a full ration and at the same time injected with large quantities of insulin is of particular interest in this connection. The ration was adequate and the cow ate well, yet her production declined to a fifth of her normal milk yield. Her chart shows that there was a slight reduction in her blood sugar when insulin was introduced into the blood stream. It seems furthermore likely that this sugar was not as available to milk secretion, since there appears to be more than a corresponding drop in the lactose content of the milk. The work of Luck et al. would seem to indicate that there should be a like drop in the amino acids of the blood. These two conditions would lead, according to the work of Cary and Meigs, to a reduction in the concentration of the nitrogen of the milk. Actually, in the experiment as it was performed, the nitrogen increased to a value about 40 per cent above normal. A somewhat similar conflict is noted in two of the other three insulin experiments where starvation accompanied insulin injection. To this extent it would seem that the factor deserving most emphasis in its immediate effect on milk yield is the energy available, and that the later and more secondary factor is the amino acid concentration of the blood. In the starvation experiments, the butter fat percentage of the milk rises rather uniformly with the duration of starvation. In the insulin experiments, however, the charts appear to show a marked reduction in this butter fat percentage immediately after the introduction of insulin. This is particularly noticed after the second and third injections. Since the dextrose of the blood tends to be reduced and made unavailable to the general physiological processes by the presence of the large excess of insulin, and since this reduction of the butter fat percentage is noted as an accompanying phenomenon, it would appear that the blood dextrose plays a part in the synthesis of milk fat as well as being the source of the milk lactose, possibly as a source of energy in converting body fat to butter fat. In this regard the results for the treatment of Cow 47 with phloridzin are of importance. As noted by others, the introduction of phloridzin causes a marked rise in the fat percentage of the milk. The lactose per cent is also higher than that noted in starvation. Since phloridzin, by lowering the threshold for the blood sugar, causes large quantities of it to be drained from the body through the urine, and therefore reduces the reserve supply, it follows that if the insulin hypotheses are correct we should expect an eventual lowering of the lactose and of the fat below the starvation level. During the last of the experiment this is what was actually observed. The effects of starvation and of insulin furnish concordant proof for the theory that the lactose of milk is derived from the sugar of the blood. The fact that the different constituents of the milk, the fat, the lactose, the nitrogen, and the ash, do not exactly parallel each other in their behavior throughout these experiments indicates that they have in all probability separate origin. This is particularly true of the butter fat percentage, which appears to have a rate of secretion which is more or less independent of the other constituents, and higher in amount. This result would fall in line with the conclusion of the writers in a previous paper in which it was indicated that the fat of the blood was very likely deposited in the udder as fat corresponding to body fat from which source it was metabolized into the fat of milk shortly before it was needed for milk secretion. The wide variation brought about in the constituents of the milk by the treatment all point to the conclusion that in milk secretion a balance is maintained between the osmotic pressure of the milk and of the blood. Thus when the sugar of the milk is reduced either through starvation or by insulin the ash constituents rise to compensate for this reduction and make the osmotic pressure of the milk similar to that of the blood. These results further appear to indicate that the salts and the sugars are more or less independent in their passage and metabolism into milk from the other constituents. These observations are therefore in line with those obtained by Jackson and Rothera (14) and by Davidson (15) in their brilliant experiments where they modified milk secretion by returning milk or milk sugars and salts to the udder. These experiments give direct proof for the conclusion that modifications of the blood of dairy cattle produce direct and predictable modification of the milk secreted. PMID- 19872628 TI - TEMPERATURE CHARACTERISTICS FOR THE PRODUCTION OF CO(2) BY GERMINATING SEEDS OF LUPINUS ALBUS AND ZEA MAYS. AB - The rates of production of CO(2) by germinating seeds of Lupinus albus and Zea mays were studied between temperatures 12.5 degrees and 25 degrees C. with the HCl-Ba(OH)(2) titration method. The temperature characteristics found are different from those previously obtained for the oxygen consumption of the same seeds germinated in the same manner. For Lupinus, the temperature characteristics above and below the critical temperature of 20 degrees are 16,100 +/- and 24,000 +/- calories respectively. For Zea, no evidence of a critical temperature was found in this region, and the temperature characteristic is 20,750 +/- calories throughout the range of temperature tested. The possible interpretations of the difference in the values of temperature characteristics for oxygen consumption and for production of CO(2) are noted. PMID- 19872629 TI - THE EFFECT OF RADIATIONS FROM A MERCURY ARC IN QUARTZ ON ENZYMES : II. THE EFFECT OF ULTRA-VIOLET RADIATION ON AMYLASE IN SOLUTION. AB - Amylase in solution is inactivated by the radiations from a mercury arc in quartz, in a manner similar to that previously reported for pepsin. The reaction was followed to a point where more than 88 per cent change had taken place, the course being that of mono-molecular radiochemical change. Apparently, this reaction is due to the influence of ultra-violet radiation alone. PMID- 19872630 TI - THE ROLE OF PHOSPHATE IN BIOLOGICAL OXIDATIONS. AB - 1. The effect of phosphate on the oxidation of glyceric aldehyde by methylene blue, 1-naphthol 2-sulfonate indophenol, and phenol-indophenol has been studied. 2. At pH 4.77 in a phthalate-buffered medium phosphate does not catalyze the reaction. 3. At pH 7.9 in solutions buffered with borate, carbonate, or phenylalanine marked catalysis by phosphate is observed. The effect is most pronounced in borate. 4. Phosphate catalysis, within the limits studied, is strictly a linear function of the phosphate concentration. 5. The high concentration of HPO(4) (=) and the low concentration of PO(4) ( identical with) relative to that of the substrate virtually demand the conclusion that the PO(4) ( identical with) ion is the active catalytic species. PMID- 19872631 TI - STIMULATION BY HYDROCHLORIC ACID IN THE CATFISH, SCHILBEODES. AB - 1. The reaction of the catfish, Schilbeodes gyrinus Mitchill, to hydrochloric acid over a wide range of concentrations (from pH 1.82 to pH 6.83) has been studied under experimental conditions which reduced to a minimum all other stimuli. 2. As the [H(+)J increases within the limits mentioned, the reaction time of the fish decreases. In other words, the rate of the stimulation processes is an increasing function of the hydrogen ion concentration. 3. The effective stimulus is the hydrogen ion, since NaCl solutions of equivalent concentration were not stimulating. 4. Stimulation by hydrochloric acid is therefore correlated with the potential of the cation resulting from dissociation of the acid molecule. PMID- 19872632 TI - THE COMBINATION OF A STANDARD GELATIN PREPARATION WITH HYDROCHLORIC ACID AND WITH SODIUM HYDROXIDE. AB - It has been found possible to obtain constant dry weights of sheet gelatin only by drying in vacuo at temperatures below 100 degrees C. for a period of several weeks. Values are given for the ash and nitrogen content, the specific conductivity, and the isoelectric point of a standard gelatin preparation. By the method of E.M.F. measurements of cells without liquid junction, of the type Ag, AgCl, HCl + gelatin, H(2), it has been found that this gelatin in 0.1 M HCl combines with a maximum of 9.58 x 10(-4) equivalents of H(+) and 2.0 x 10(-4) equivalents of Cl(-). By means of pH measurements with the hydrogen electrode and a KCl junction, the combination curve of this gelatin with H(+) from HCl and OH( ) from NaOH has been determined between pH 1.1 and 12.5. PMID- 19872633 TI - PHOTOCELL ANALYSIS OF THE LIGHT OF THE CUBAN ELATERID BEETLE, PYROPHORUS. AB - Records are reproduced showing various types of luminescence intensity-time curves for the prothoracic light organs of Pyrophorus. A small (5 per cent) rhythmic fluctuation of light intensity during the reflex emission of light is to be observed in many records, which because of its rapid rate is attributed to rhythmic nerve discharge from a photogenic centre. Longer "pulsations" of luminescence intensity (25 per cent change) can be detected by the eye. PMID- 19872634 TI - HIGH SPEED PHOTOMICROGRAPHY OF LIVING CELLS SUBJECTED TO SUPERSONIC VIBRATIONS. AB - A new type of camera system is described capable of taking 1200 pictures a second through a microscope objective. Photographs showing the destruction of Arbacia eggs by high frequency sound waves indicate that the disintegration occurs in less than 1/1200 second. Eggs drawn out into spindle or tadpole shapes suggest that rapid movements of the fluid tearing the eggs may be responsible for the disintegration. Although no cavitated air bubbles show in the photographs, other experiments make it likely that the rapid fluid movement is the result of submicroscopic cavitation. PMID- 19872635 TI - STUDIES ON CRYSTALLINE UREASE : IV. THE "ANTITRYPTIC" PROPERTY OF CRYSTALLINE UREASE. AB - 1. Crystalline urease is not inactivated by trypsin in the absence of a gum. In fact, the presence of trypsin alone in aqueous solutions of urease has an action similar to that of gum, that is, it acts as a "protective colloid" for urease. 2. Crystalline urease is inactivated by trypsin in the presence of a gum. This occurs with great rapidity if purified (crystalline) trypsin is used. 3. If trypsin is added to urease a considerable time before the addition of gum no inactivation of the urease takes place. 4. The suggested explanation is that an inhibitive group of the urease molecule ("antitrypsin") may combine with trypsin to form an irreversible inactive trypsin compound, which cannot attack the urease but has unchanged ureolytic power. This compound cannot be formed if gum is present because the gum has united with a portion of the urease molecule; the tryptic power is thus unimpaired and urease is then digested. This speaks for the protein nature of urease. PMID- 19872636 TI - THE SOL-GEL TRANSFORMATION IN GELATIN. PMID- 19872637 TI - ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : I. FUCUS VESICULOSUS. AB - 1. The unfertilized eggs of Fucus vesiculosus, in the dark, consume about 5.2 mm.(3) O(2) per hour per 10 mm.(3) eggs. 2. With an illumination of 100,000 foot candles in photosynthesis they liberate more than twice as much oxygen as they consume. 3. The actively swimming antherozoids or sperm of Fucus consume oxygen at a very high rate: 25.5 mm.(3) O(2) per hour per 10 mm.(3) antherozoids. 4. Immediately following fertilization, in the dark, the Fucus eggs increase the rate of oxygen consumption to about 190 per cent of the prefertilization rate. 5. This rate for fertilized eggs, about 190 per cent, is maintained uniformly for 13 or 14 hours, after which there is a barely perceptible rise until 24 hours (when measurements ceased). At 18 degrees C. 50 per cent of the spores in a population have completed the first cell division about 15 hours after fertilization. PMID- 19872639 TI - ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : III. NEREIS LIMBATA. AB - 1. The rate of consumption of oxygen by unfertilized Nereis eggs is about 1.1 mm.(3) O(2) per hour per 10 mm.(3) eggs. 2. Following fertilization the rate increases to 135 per cent or 145 per cent of the prefertilization rate, and continues to increase for 2 hours (the duration of the measurements). PMID- 19872638 TI - ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : II. CUMINGIA TELLINOIDES. AB - The rate of oxygen consumption by the eggs of the clam Cumingia decreases following fertilization, resembling in this respect a similar phenomenon of the eggs of the annelid Chaetopterus. The unfertilized Cumingia eggs consume approximately 3.1 mm.(3) O(2) per hour per 10 mm.(3) eggs. The average consumption of fertilized eggs over the period 10-60 minutes after fertilization is 1.4 mm.(3) O(2) per hour per 10 mm.(3) eggs or about 45 per cent of the prefertilization rate. PMID- 19872640 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. III : PART 1. PMID- 19872641 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. III : PART 2. AB - Extension of analysis of the functional basis of geotropic excitation and response in young rats has made it desirable to obtain, for additional genetically stabilized lines, further tests of the quantitative reproducibility of orientation data as secured from successive generations in these lines over a period of several years; and of the measures of variation of performance as these are related to the exciting vector and to the extent of orientation. Procedures are illustrated whereby the significance of measurements can be checked automatically. It is shown that differences apparent in the geotropic behavior of three inbred lines of R. norvegicus are quantitatively recoverable over a period of nine generations. The constant, characteristic features for each inbred line concern: the extent of upward orientation, absolutely and as a function of the inclination of the substratum; the threshold slope for orientation; the dispersion of mean orientation-angles as governed by the slope of substratum; the dependence of the dispersion of the relative variation of observed orientation angles upon the intensity of excitation; and the proportion of the total variation of response which is modifiable as a function of the slope of surface. It is also shown that when for two lines of rats the curves connecting orientation-angle with inclination of substratum differ in position and in details of form, the curves none-the-less undergo distortions of homologous type when rats of these lines creep geotropically with the same additional load in the form of a mass attached at a corresponding position on the back; and that shifting this mass to another position induces a quite different modification of the curve. These effects are discussed in terms of the view that orientation during geotropic creeping is controlled by the adjustment of sensorially equivalent tension-excitation in the legs of the two sides of the body, and that the frequency distributions of thresholds for excitation within the several groups of receptor units concerned differ quantitatively among the inbred stocks, but are statistically constant within each line. PMID- 19872642 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. IV. AB - The geotropic orientation of young rats of a closely inbred line P, separated 6 years ago from a stock which gave rise also to the closely inbred lines A and B previously studied, has been measured. The curve connecting orientation-angle with inclination of substratum is in a general way similar to those for A, B, and with them differs markedly from that for race K of totally different ancestry. The variability of the response exhibits similar affinities. Although the orientation-angles are rather close to those obtained with A, the threshold slope for P is that for B; analysis of the curve discloses how this fact is related to the character of the presumptive distributions of thresholds for the respective arrays of tension-receptor units. It is pointed out that these considerations prevent loose comparisons of "geotropic sensitivity" in different lines of rats, but make it plain why comparisons in terms of thresholds for response or of magnitude of response at the same threshold are ineffective. The estimated "number of excitation units," however, is found to correspond to the variability of orientation, and to the manner and extent whereby the dispersions of the measured orientation-angles are governed by the magnitude of the gravitational vector. PMID- 19872643 TI - A CHEMICAL EXPLANATION OF THE VARIABILITY OF THE GROWTH RATE. AB - The general belief that uniform cells under uniform conditions will all multiply at the same moment implies that the smallest units of the chromosomes, i.e., either the genes or the molecules of which the genes are composed, all double at exactly the same moment in all cells. Since the doubling of chromosomes is a synthetic chemical process, it seems more probable that it would follow chemical laws. With the assumption that the corresponding molecules in a number of uniform cells obey the mass law in their process of doubling, a definite order in the multiplication of identical cells is established which can be formulated mathematically for the simplest case. This is the same assumption which the author has used to account for the differences in the order of death between bacteria and higher organisms. This theory demands a great variability of the growth rate of uniform cells, so great that it must be experimentally measurable even for cells with a million molecules to the chromosome. The theory demands further that the frequency curve of cell divisions plotted for successive time intervals, be skewed to the left, and that the relative range of variation become smaller as the number of genes or gene-type molecules increases. Experiments on the growth rate of Bacterium aerogenes and Saccharomyces ellipsoideus showed regularly a frequency curve skewed to the left. The yeast had a relatively narrower range of variability than the bacterium. Even with multicellular organisms, theoretical calculations show a range of variation of the growth rate from the egg cell which should still be measurable though it decreases relatively with the number of cells produced. An experiment on the size of bacteria colonies at different ages of development agreed with the theory. PMID- 19872644 TI - ELECTROKINETIC PHENOMENA : V. A SMALL BUT CONSTANT SOURCE OF ERROR IN MEASUREMENTS OF VISCOSITY. PMID- 19872645 TI - VARIATION OF THE ELECTRIC RESISTANCE OF PLANT TISSUES FOR ALTERNATING CURRENTS OF DIFFERENT FREQUENCIES DURING DEATH. PMID- 19872646 TI - ON THE PHYSICAL NATURE OF "CYTOTROPISM" AND ALLIED PHENOMENA AND THEIR BEARING ON THE PHYSICS OF ORGANIC FORM. AB - From thermodynamical considerations expressions are derived for the forces which will act on a liquid drop suspended in another liquid, if the latter contains in solution a substance whose concentration is non-uniform. It is shown that forces of attraction and repulsion between two such drops may result, if the drops are seats of chemical reactions, which produce substances diffusing into the surrounding medium. An estimate of the order of magnitude of such forces is made, and it is found that they may exceed the electrical forces which would result from the charges which the drops may possess. A possible experimental method of studying such forces is suggested. The possible connection of the above forces with those observed in the phenomena of "cytotropism," and their bearing on the physical explanation of organic form, especially of the phenomena of "induction," is briefly discussed. PMID- 19872647 TI - THE SENSIBILITY OF THE SUN-FISH, LEPOMIS, TO MONOCHROMATIC RADIATION OF LOW INTENSITIES. AB - 1. A test is proposed of the hypothesis that visual purple is the photosensitive substance concerned in dim vision. It is based on the fact that fish visual purple is different from that of other vertebrates. If the hypothesis is correct, the fish dim-visibility function should be different from that of other vertebrates and should be determined by the absorption spectrum of its visual purple. 2. A new method is described for obtaining the visibility function of fish, in quantitative terms. It depends on the measurement of the least amounts of various spectral energies which will produce a visual orienting response to the displacement of a constant background. 3. Data are presented on thirteen animals. It is shown that the maximum of the visibility function is identical with the maximum of the absorption spectrum of fish visual purple. The shapes of the visibility curves obtained are, however, variable and different from that of the absorption spectrum. 4. The possibility that Lepomis visual purple is different from that of other fish is ruled out by a series of measurements which confirm the results of Koettgen and Abelsdorff on other fish. 5. Reasons are given for the conclusion that there are present in Lepomis special conditions which distort the visibility curve out of true agreement with that predictable from the absorption spectrum of its visual purple. The suggestion is made that the presence of light absorbing, but not light sensitive, pigments is responsible for this distortion. One of these pigments may perhaps be carotin while the second is unspecified. PMID- 19872648 TI - THE ROLE OF INTRACELLULAR BACTERIOPHAGE IN LYSIS OF SUSCEPTIBLE STAPHYLOCOCCI. PMID- 19872649 TI - THE EFFECT OF ADDED LOADS UPON THE GEOTROPIC ORIENTATION OF YOUNG GUINEA PIGS. AB - It has been found that young guinea pigs when progressing over a surface inclined at an angle alpha with the horizontal, orient upward in a way such that the path described by an oriented animal is at a mean angle theta with the base of the inclined surface. The magnitude of mean theta increases as the angle of inclination alpha increases. The function relating theta and alpha is compound, being made up of two sections with a break which corresponds to a change in the mode of progression of an animal over the surface of the plane. If a load of constant relative mass is attached to the back of an animal, midway between the fore and hind legs, testing on an inclined surface reveals the fact that the magnitude of mean theta is increased over the entire range of stimulation, with the two values of mean theta (i.e. with and without added load) becoming more nearly equal as they approach 90 degrees as a limiting value. The variation (P.E. of mean theta) is not sensibly changed by attaching a load to an orienting animal; for equal magnitudes of theta, under the two sets of test conditions, the P.E.'s are very nearly equal. PMID- 19872650 TI - THE EFFECT OF DENATURATION ON THE VISCOSITY OF PROTEIN SYSTEMS. AB - The viscosity of a protein solution is increased by the denaturation of the protein. This is true both when there is the formation of protein aggregates which occlude water and when there is no aggregation. Under certain conditions, as a result of the aggregation following denaturation, a solution containing only one per cent of protein may be converted into a clear gel. The conditions for obtaining very viscous solutions containing little denatured protein are always close to the conditions for actual precipitation and under these conditions the viscosity is very sensitive to slight changes in the concentration of salts and hydrogen ions. PMID- 19872651 TI - THE KILLING OF COLON BACILLI BY ULTRAVIOLET LIGHT. AB - The survival ratios of colon bacilli subjected to several monochromatic ultraviolet radiations follow semilogarithmic straight lines. For each wave length approximate observations have been made of the energy involved in cell destruction. This energy varies somewhat with frequency in the ultraviolet region; it is furthermore nearly one hundred times as great as the amount of X ray energy required to bring about the same killing. Preliminary experiments show no measurable difference either in rate of killing or in lethal energy between B. coli and B. aertrycke. Parallel results have already been obtained with X-rays and electrons. The data from colon bacilli are interpreted in terms of the assumptions employed for X-rays. They indicate that though bacterial death should result from a single quantum absorption, millions more such absorptions seemingly are without injurious effect on cell growth and multiplication. The "sensitive volume" within which, according to this picture, the lethal quantum must be stopped proves to be about the same as that of a single protein molecule. If this is the correct description of the phenomena of ultraviolet killing, it seems strange that the millions of non-deadly quanta absorbed per bacillus should not show themselves by altered growth rates or in other ways. That they apparently do not suggests the inapplicability of the statistical picture. The death rate under this kind of radiation then would be primarily an expression of the relative sensitivities of the bacterial population. Additional experiments are required to determine this question. PMID- 19872652 TI - THE HEAT INACTIVATION OF ANTISTAPHYLOCOCCUS BACTERIOPHAGE. PMID- 19872654 TI - A SEPARATION OF THE REACTIONS IN PHOTOSYNTHESIS BY MEANS OF INTERMITTENT LIGHT. PMID- 19872653 TI - INTERMITTENT STIMULATION BY LIGHT : I. THE VALIDITY OF TALBOT'S LAW FOR MYA. AB - On the basis of previous knowledge of the photosensory behavior of Mya it is shown that Talbot's law for the effectiveness of stimulation by intermittent illumination should be valid. Two series of measurements are reported in which the photosensory effects of intermittent and continuous illuminations are compared. The results demonstrate the validity of Talbot's law for Mya. PMID- 19872655 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. V. AB - Young rats bearing a mass of 1.06 gm. both at shoulder level on the back and posteriorly at the sacrum exhibit in their geotropic progression a relationship between angle theta of oriented path and inclination alpha of substratum which differs from those obtained with rats of the same race carrying the same total added load concentrated anteriorly or posteriorly. The distributed load affects more or less equally all the groups of receptor units concerned in tension excitation. It is shown that the variation of orientation is organically determined, quantitatively, by the intensity of tension excitation, regardless of the imposition of the added loads. The bearing of these facts upon the theory of the geotropic orientation is discussed. PMID- 19872656 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. VI. AB - Races of Rattus norvegicus labelled A and B give characteristic curves relating angle of orientation theta during geotropic progression to the inclination (alpha) of the surface. The orientation-angles for B are higher at every slope, and the threshold slope for orientation is lower in B. When these races are cross bred, the F(1) progeny show a theta-alpha curve in general corresponding to that for the B parent, as regards both threshold slope and magnitudes of theta. Differences between the curve for F(1) and B have to do (1) with a slight but significant distortion of the curve, such that from alpha = 15 degrees to about (alpha = 35 degrees the mean curve is slightly above that for B, whereas above this slope of surface, theta is consistently below that for B, and (2) below alpha = 35 degrees the horizontal latitude of variation in the curve theta vs. log sin alpha is much greater than above alpha = 35 degrees . The first distortion is interpreted as due to the fact that, as a manifestation of heterosis, developmental processes which upon the one hand lead to growth in bulk in the posterior region of the body, and on the other which would lead to a proportionate development of tension receptors in the legs, fail to keep pace harmoniously. In ordinary development of individuals in a pure line, harmonious relationships between these two aspects of growth are maintained. The variation of response (theta) is not altered in F(1), if attention is paid to the total observed variation; but the unmodifiable or uncontrollable portion of the total variation of theta, not affected as a function of sin alpha, is increased. This fact is more pronounced in female offspring from the matings A male symbol x B female symbol. This effect in F(1) is interpreted as due to the introduction of modifying genetic influences, which affect variation of orientation. The percentage of modifiable variation is reduced from 74 per cent (mean) in B to about 59 per cent in F(1). These interpretations are checked by the behavior of offspring produced in the backcross F(1) x B. The disharmony of developmental processes thought to be signalized by the distortion of the form of the theta alpha curve disappears completely in these backcross individuals. It can be computed that an equivalent distortion of the theta-alpha curve for B would be produced by the posterior attachment of a mass of about 0.5 gm., unaccompanied by its proportion of receptors in the legs; in backcrossing to the B line, this should be reduced in the average to about "0.25 gm.," which is at about the threshold for any detectable effect of a mass added posteriorly. The variability of theta in (F(1) x B) is not different from that for B, or for F(1) (total variation); but, as must be expected if the unmodified variation has been increased in F(1) by the action of modifying genetic influences not directly connected with the genes determining the numbers of tension-receptors, we find that in (F(1) x B) the percentage of modifiable variation is returned half-way (65 per cent) toward that for the B line. The bearing of certain considerations derived from the treatment of this case is discussed with reference to the desirability that other phenomena of "hybrid vigor" and heterosis be similarly analyzed. PMID- 19872657 TI - THE COMBINING WEIGHT OF GELATIN AS AN ACID. AB - 1. The nature of the reaction between gelatin and sodium hydroxide has been studied at three concentrations of gelatin. 2. Gelatin appears to react stoichiometrically with sodium hydroxide. 3. The addition of gelatin to sodium hydroxide does not change the concentration of sodium ions in the solution. 4. A given amount of gelatin reacts with the same amount of sodium hydroxide no matter what the concentration of sodium hydroxide or ratio of sodium hydroxide to gelatin, provided there is sufficient excess of sodium hydroxide to prevent hydrolysis. 5. The combining weight of dry gelatin as an acid is found to be 1370 gm. PMID- 19872658 TI - THE MOBILITY OF THE GELATINATE ION. AB - 1. Many measurements were made with the two systems H(2)/NaOH C/NaOH C + x gm. gelatin/H(2) H(2)/NaOH C/KCl (sat.)/NaOH C + x gm. gelatin/H(2) in which x was varied from zero to more than enough for complete combination. 2. From these measurements the change in boundary potential with quantity of gelatin present was determined. 3. The boundary potentials were calculated by means of a modified form of the Henderson equation. 4. The results indicate that the mobility of the gelatinate ion is about 20. PMID- 19872659 TI - ON "REVERSAL" OF PHOTOTROPISM IN PHYCOMYCES. AB - Alleged reversal of the phototropism of the sporangiophores of Phycomyces by high intensities of light does not occur if infra-red radiation is properly excluded. Phototropic "indifference" alone occurs at high intensities due to equal photic action on both sides of the sporangiophore. If heat radiation is not screened out, a gradual, negative thermotropic bending takes place. PMID- 19872660 TI - SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. AB - 1. A method is given whereby the course of hydrolysis of sucrose by live yeast cells may be followed with precision equal to that found when invertase solutions prepared from autolyzed yeast are used to cause inversion. 2. The practical value of the equation of Nelson and Hitchcock as a means of following the course of enzymic hydrolysis of sucrose is hereby extended. 3. The inversion of sucrose by live yeast cells and by extracted invertase has been quantitatively compared. 4. The course of hydrolysis of sucrose by the invertase of Fleischmann's yeast has been found to be identical in vivo and in vitro. PMID- 19872661 TI - THE TEMPERATURE CHARACTERISTIC OF RESPIRATION OF AZOTOBACTER. AB - The temperature characteristic of respiration of Azotobacter vinelandii possesses a constant value of 19,330 +/- 165 over the temperature range 20-30 degrees C. This value is independent of pH, oxygen tension, age of culture, and other factors within the limits studied. The optimum temperature of respiration is 34 35 degrees C., with limits at about 10 degrees and 50 degrees C. PMID- 19872662 TI - THE SPECTRAL SENSIBILITY OF THE SUN-FISH AS EVIDENCE FOR A DOUBLE VISUAL SYSTEM. AB - 1. An extension of a previously described method makes possible the measurement of the visibility function of Lepomis at high intensities of spectral illumination. This is accomplished by determining the relative energies of various spectral beams which will just produce a visual orienting response by the animal to the movement of a pattern composed of fine lines. 2. The function so determined is different from that obtained with a pattern composed of wide bars and spaces at a lower intensity level. 3. This difference furnishes direct and quantitative proof that the eye of Lepomis is a physiologically duplex visual system and parallels the known anatomical distinctions between the rods and cones. 4. A comparison of the visibility curves of the two systems indicates that both functions are similar in shape but that the cone curve is shifted to the red. 5. It is suggested that this relation between the two systems, which is also found in the human and the fowl, indicates that the photosensory substance is the same in each case for the rods and cones. According to this hypothesis, the shift of the cone curve is due to a common physical cause which depends on differences in the properties of the solvent media in the cones and in the rods. PMID- 19872663 TI - DISSIMILARITY OF INNER AND OUTER PROTOPLASMIC SURFACES IN VALONIA. III. AB - Evidence that the inner and outer protoplasmic surfaces in Valonia are unlike is found in the high P.D. across the protoplasm when the external solution has the same composition as the vacuolar sap. Earlier experiments with artificial sap have been repeated, using natural as well as artificial sap. Good agreement between the data with the natural and the artificial solution was found both in the magnitude of the P.D.'s observed and in the shape of the P.D.-time curves. The P.D.'s, however, were considerably higher than the values formerly reported as usual, while the cells proved much less liable to alteration produced by exposure to sap. It is suggested that the cells used in the recent experiments were in a more vigorous condition, perhaps as a result of exposure to stronger illumination. The interpretation of the shape of the P.D.-time curves, proposed in an earlier report, and based on the theory of protoplasmic layers, is further discussed. It is assumed that the fluctuations in P.D. are due to an increase in the concentration of K in the main body of the protoplasm. PMID- 19872664 TI - THE ACCUMULATION OF ELECTROLYTES : IV. INTERNAL VERSUS EXTERNAL CONCENTRATIONS OF POTASSIUM. AB - Lowering the potassium in the sea water from 0.011 M to 0.006 M caused an exit of potassium from cells of Valonia macrophysa. Sodium continued to penetrate and the ratio K / Na fell off. The cells ceased to grow but there was no evidence of injury. Increasing the external potassium brought about an increase of the internal concentration of potassium, of halide, of total cations, and of the ratio K / Na inside. These phenomena are to be expected on theoretical grounds. PMID- 19872665 TI - THE ADSORPTION OF GELATIN BY COLLODION MEMBRANES. AB - An experimental study has been made of the adsorption of gelatin from solution at 37 degrees C. by collodion membranes. In the case of membranes of high permeability, very high concentrations of gelatin were required to produce maximum adsorption, and the maximum amounts adsorbed were independent of the pH values of the solutions over the range 3.8 to 4.8. With membranes of low permeability, maximum adsorption was reached at lower gelatin concentrations, and the maximum amounts adsorbed varied with the pH, being lower on either side of the isoelectric point, over the range 3.8 to 6.6. The addition of salt in such experiments raised the maximum amount adsorbed to a value equal to that obtained with solutions at the isoelectric point in the absence of salt. These experiments can be explained by, and seem to lend support to, the theory proposed by Loeb and further developed by Kunitz concerning the effects of pH and salt on the size of gelatin particles in solution. PMID- 19872666 TI - ON THE RESPIRATORY QUOTIENT OF LUPINUS ALBUS AS A FUNCTION OF TEMPERATURE. AB - The temperature characteristics for the oxygen consumption and CO(2)-production of the germinating seeds of Lupinus albus were previously found to be different. It was predicted qualitatively that the respiratory quotient of the seed should be a function of temperature. A quantitative treatment is presented here, relating the change of the respiratory quotient with temperature and the temperature characteristics. Experimental results agree satisfactorily with the calculated value. PMID- 19872667 TI - A RESPIROMETER VESSEL FOR STUDY OF METABOLISM OF SEEDS. PMID- 19872668 TI - ELECTROKINETIC PHENOMENA : VI. RELATIONSHIP BETWEEN ELECTRIC MOBILITY, CHARGE, AND TITRATION OF PROTEINS. AB - 1. By combining the theories of Smoluchowski, Debye and Huckel, and Henry it is possible to state explicitly (making necessary assumptions) under what conditions the following simple rule should be valid for proteins: In solutions of the same ionic strength, the electric mobilities of the same protein at different hydrogen ion activities should be proportional to the number of hydrogen (hydroxyl) ions bound. 2. Data of Tiselius and of the writer confirm this rule for (a) egg albumin, (b) serum albumin, (c) deaminized gelatin and gelatin, and (d) casein. 3. On the basis of the confirmed theory the titration curves of certain proteins are predicted from their mobilities. 4. It is shown that when certain proteins are adsorbed by quartz the apparent dissociation constant of the adsorbed protein is practically unchanged. The mass law must also be valid at the phase boundary. 5. The facts of paragraphs (1) to (4) are discussed in connection with the mechanism of (a) protein adsorption, (b) enzyme activity, (c) immune reactions, (d) the calculation of the electric charge of cells, and (e) criteria of surface similarity. PMID- 19872669 TI - ELECTROKINETIC PHENOMENA : VII. RELATIONSHIP BETWEEN ELECTRIC MOBILITY, CHARGE, TITRATION CURVE, AND OPTICAL ROTATION OF PROTEIN. AB - The specific rotation of egg albumin, gliadin, and gelatin (40 degrees C.) is discussed in connection with available data on (a) mobility, (b) titration curve, and (c) osmotic pressure. It seems likely that the change in specific rotation with pH of protein solutions is proportional to the change in net charge. PMID- 19872670 TI - STIMULATION BY THE SALTS OF THE NORMAL ALIPHATIC ACIDS IN THE ROCK BARNACLE BALANUS BALANOIDES. AB - 1. Stimulation in the rock barnacle Balanus balanoides by the sodium salts of the first seven normal aliphatic acids has been studied at several different concentrations for each salt. The pH was adjusted to that of sea water (8.1 +/ 0.15) and all experimental conditions were held as constant as possible. Criterion of response was the per cent closure of valves at successive 2 minute intervals. 2. In general, the stimulating efficiency increases with concentration, but the ratios of effectiveness at increasing concentrations differ for each salt. 3. The order of effectiveness for 40 to 50 per cent closure is: heptylate = caproate > valerate > butyrate > formate > propionate > acetate. For 60 per cent closure or more, formate is the least effective of all. 4. Stimulating efficiency is correlated with the potential of the anion of the acid and with the concentration of that ion near or at the receptor surface as determined by the length of the carbon chain. PMID- 19872671 TI - STIMULATION BY HYDROCHLORIC ACID AND BY THE NORMAL ALIPHATIC ACIDS IN THE SUNFISH EUPOMOTIS. AB - 1. The reaction of the sunfish, Eupomotis gibbosus, to different concentrations of hydrochloric acid and of the first six members of the N aliphatic acids has been studied. 2. The stimulating efficiency of hydrochloric acid may best be related to the concentration of hydrogen ions produced by that acid. 3. The stimulating efficiency of the N aliphatic acids may best be correlated with the non-polar nature of a portion of the molecule, but it is necessary to consider the higher potential of the polar group of formic acid to account satisfactorily for its position in the series. 4. When equally effective concentrations of the N aliphatic acids are compared, formic acid is more effective at lower concentrations than at higher. 5. Per cent variation in response appears to be independent of the chemical environment to which the animal responded. PMID- 19872672 TI - PORPHYRIN COMPOUNDS DERIVED FROM BACTERIA. AB - The pigment contained in the extracts obtained from B. phosphorescens by freezing and thawing, and in the alkaline extracts of B. phosphorescens and yeast, resembles the "cytochrome c" of Hill and Keilin (6) and the "porphyratin B" of Schumm (7) in giving absorption bands at mmicro 552-550 and 522-520) but shows in addition a band about 575, as in the "hemochromogen A" obtained by Keilin (3) by prolonged treatment of yeast with strong alkali. Like cytochrome c the pigment of yeast extracts appears to be distinct from the ordinary hemochromogen of blood, because of the difference in position of the bands of the native materials and of the corresponding pyridine hemochromogens. On treatment with acetic acid, however, the yeast extract yields alpha-hematin, as identified spectroscopically. It is evident then that one portion of its iron-porphyrin nucleus is identical with alpha-hematin (iron-protoporphyrin), which must be present not as such, but in chemical combination. The alkaline extracts of C. diphtheriae, compared with those of The alkaline extracts of C. diphtheriae, compared with those of B. phosphorescens and yeast, show a constant difference in the position of the two bands in the green, which lie nearer the red end of the spectrum, at mmicro 556 and 528. This extract likewise on treatment with acetic acid yields alpha hematin, which in the form of its alkaline hemochromogen may be responsible for the bands in the alkaline extract at mmicro 556 and 528. Great interest has attached in our investigation to the substance responsible for the absorption band in the alkaline extracts about 575. Extraction with acetic acid-ether of these alkaline solutions, as well as of the whole bacteria, yields a material which shows absorption bands at mmicro 575-574 and 539-535, and appears to be identical with a complex porphyrin which has been found in culture filtrates of C. diphtheriae. This complex porphyrin has been described in a previous paper (1). It is labile and breaks down readily to yield coproporphyrin and the copper compound of coproporphyrin, and is apparently the source of the coproporphyrin which is often found free in the culture filtrates. In the work repeated earlier we had been unable to obtain this complex porphyrin, or porphyrin compound, directly from the bacteria. In the present work we have been successful in obtaining it from the three species investigated. The behavior of the complex porphyrin extracted from the whole bacteria is the same as of that found in filtrates. It is insoluble in 25 per cent HCl, and on disintegration gives coproporphyrin and the copper compound of coproporphyrin. Information is quite lacking as to the particular form of combination in which this complex porphyrin occurs within the cell. The complex porphyrin is certainly not present there in the form in which it appears in the extracts. If diphtheria bacilli showing strong absorption bands of reduced cytochrome, while under examination with the microspectroscope are treated with glacial acetic acid, the bands of cytochrome are seen to fade and are replaced by those of the complex porphyrin at mmicro 575 and 539. The origin of the copper which is found, combined with coproporphyrin, as a product of the disintegration of the porphyrin compound, has been a matter of uncertainty. In the case of filtrates of C. diphtheriae it has seemed possible that the copper was never a constituent of the bacteria, and that combination with copper occurs only after the porphyrin has been liberated from the bacterial cell. With washed bacteria, however, the presence of copper in extracts indicates that this element has been taken up from the culture medium and incorporated within the cell. Whether or not the copper is there combined with porphyrin cannot be decided by the present evidence. Copper occurs naturally, however, in combination with porphyrin in turacin (14), a pigment of the wing feathers of certain birds. In the present case such combination seems the more probable, so that the complex porphyrin may represent a form in which copper is contained within the cell. Objection may be raised to the use of the term complex porphyrin or porphyrin compound for the substance referred to here and in the previous paper (1). The name hemochromogen might be applied with equal justification. Until the chemical nature of the substance is better known, however, it seems best not to use any but a simple descriptive name. Reference should not be omitted here to the bacteriological significance of this compound, which arises from the correlation which we have previously observed between its amount and the content of toxin, in filtrates of C. diphtheriae. In respect to this porphyrin compound the pathogen C. diphtheriae seems to differ from the nonpathogenic forms in the readiness with which the material is liberated from the bacteria in cultures, rather than in the nature of the material. PMID- 19872673 TI - ELECTRIC PHASE ANGLE OF CELL MEMBRANES. AB - From the theory of an electric network containing any combination of resistances and a single variable impedance element having a constant phase angle independent of frequency, it is shown that the graph of the terminal series reactance against the resistance is an arc of a circle with the position of the center depending upon the phase angle of the variable element. If it be assumed that biological systems are equivalent to such a network, the hypotheses are supported at low and intermediate frequencies by data on red blood cells, muscle, nerve, and potato. For some tissues there is a marked divergence from the circle at high frequencies, which is not interpreted. PMID- 19872674 TI - SOME PHYSICAL AND CHEMICAL PROPERTIES OF THE CELL SAP OF HALICYSTIS OVALIS (LYNGB.) ARESCH. PMID- 19872675 TI - THE EFFECTS OF CO AND LIGHT ON THE OXYGEN CONSUMPTION AND ON THE PRODUCTION OF CO(2) BY GERMINATING SEEDS OF LUPINUS ALBUS. AB - The consumption of oxygen by germinating seeds of Lupinus albus can be reversibly inhibited by CO to a maximum extent of 36 per cent with a mixture of 24 per cent O(2) and 76 per cent CO at 18 degrees , in darkness. This inhibition is completely abolished when the seed is illuminated. On returning to air, after a period in the CO-O(2) mixture, the rate of oxygen consumption is accelerated to as much as 68 per cent over what it had been previously, in air. The production of CO(2) is apparently not inhibited by CO. The bearing of these findings on the study of the rates of gas exchange of the seeds as a function of temperature is discussed. PMID- 19872676 TI - THE ACCUMULATION OF ELECTROLYTES : V. MODELS SHOWING ACCUMULATION AND A STEADY STATE. AB - Inasmuch as attempts to explain accumulation by the Donnan principle have failed in the case of Valonia, a hypothesis of the steady state has been formulated to explain what occurs. In order to see whether this hypothesis is in harmony with physico-chemical laws attempts have been made to imitate its chief features by means of a model. The model consists of a non-aqueous layer (representing the protoplasmic surface) placed between an alkaline aqueous phase (representing the external solution) and a more acid aqueous phase (representing the cell sap). The model reproduces most of the features of the hypothesis. Attention may be called to the following points. 1. The semipermeable surface is a continuous non-aqueous phase. 2. Potassium penetrates by combining with an acid HX in the non-aqueous layer to form KX which in turn reacts with an acid HA in the sap to form KA. Since KX is little dissociated in the non-aqueous layer potassium appears to pass through it chiefly in molecular form. 3. The internal composition depends on permeability, e.g., sodium penetrates less rapidly than potassium and in consequence potassium predominates over sodium in the "artificial sap." The order of penetration in the model is the same as in Valonia, i.e., K > Na > Ca > Mg, and Cl > SO(4), but the quantitative resemblance is not close, e.g., the difference between potassium and sodium, and chloride and sulfate is much less in the model. 4. The formation of KA and NaA in the sap raises its osmotic pressure and water enters. 5. The concentration of potassium and sodium and the osmotic pressure become much greater inside than outside. For example, potassium may become 200 times as concentrated inside as outside. 6. No equilibrium occurs but a steady state is reached in which water and salt enter at the same rate so that the composition of the sap remains constant as its volume increases. 7. Since no equilibrium occurs there is a difference of thermodynamic potential between inside and outside. At the start the thermodynamic potential of KOH is much greater outside than inside. This difference gradually diminishes and in the steady state has about the same value as in Valonia. The difference in pH value between the internal and external solutions is also similar in both cases (about 2 pH units). 8. Accumulation does not depend on the presence of molecules or ions inside which are unable to pass out. One important feature of the hypothesis is not seen in the model: this is the exchange of HCO(3) for Cl(-). Experiments on this point are in progress. PMID- 19872677 TI - THE OXYGEN CONSUMPTION OF ESCHERICHIA COLI DURING THE LAG AND LOGARITHMIC PHASES OF GROWTH. AB - The oxygen consumption of rapidly growing cultures of Esch. coli (S) have been measured by means of Fenn's respirometer. The rate of oxygen consumption of a growing culture uniformly attains a phase of logarithmic increase before the growth curve of the organisms becomes logarithmic. The rate of oxygen consumption per cell increases rapidly from the time of inoculation to a point of maximum respiration near the end of the lag phase of the growth curve, followed by a gradual decrease in the respiratory rate. The surface area of the average cell when plotted against time passes through a point of maximum surface area which coincides with the point of maximum oxygen consumption per cell. Figures obtained by different methods, CO(2) output and heat production when reduced to the same units, agree remarkably well. PMID- 19872678 TI - ON THE INTENSITY-TIME RELATIONS FOR STIMULATION BY ELECTRIC CURRENTS. I. AB - Formulae are derived for the time-intensity relations for stimulation by direct currents using the following hypotheses: first, the current produces an excitatory effect whose rate of growth is proportional to the voltage; and second, the tissue reacts toward the normal state at a rate proportional to the amount of excitation. If p represents the local excitatory process numerically, the hypotheses are represented by the differential equation See PDF for Structure. where K and k are constants and V the applied voltage. For the stimulus to be adequate it is assumed that p must be built up to a certain liminal value. It appears as a deduction from the data that this liminal value is a function of the voltage of the form h +/- alphaV where h and alpha are constants. alpha is zero or negligible for certain electrodes. alphaV is a measure of electrotonus or a similar phenomenon. Experimental data are discussed and are shown to agree satisfactorily with the derived formulae for stimulation both at the anode and cathode. PMID- 19872679 TI - ON THE INTENSITY-TIME RELATIONS FOR STIMULATION BY ELECTRIC CURRENTS. II. AB - Hypotheses previously used (Blair, 1932) in deriving formulae for stimulation by direct currents are applied to other forms of electrical stimuli. This consists in considering solutions of the equation See PDF for Structure. where p is assumed to represent the local excitatory process, V is the voltage of the stimulus and K and k are constants. The solutions are discussed in regard to condenser discharges, linearly rising currents, exponentially rising currents, and alternating currents. New experimental work with alternating currents of frequencies above 400 per second on the sciatic gastrocnemius of the frog is related to the formulae. PMID- 19872680 TI - ELECTROKINETIC PHENOMENA : IX. ELECTROPHORESIS AND ELECTROOSMOSIS. AB - As previously found experimentally for crude protein surfaces, and in harmony with recent theory and experiment, the ratio of the electroosmotic and electrophoretic mobility for surfaces of purified protein is approximately -1.00. PMID- 19872681 TI - OSMOTIC RELATIONSHIPS IN THE HEN'S EGG, AS DETERMINED BY COLLIGATIVE PROPERTIES OF YOLK AND WHITE. AB - The osmotic pressure of the yolk and white of the hen's egg have been shown to be identical, by means of direct freezing point determinations, dialyses, and vapor pressure measurements. Dialysates of egg yolk slow the rate of ice formation compared with NaCl solutions. They also show a marked change of freezing rate as the freezing point is approached. The anomalous freezing behavior of this material may lead to errors in the determination of the true freezing point which would tend to make the value for the yolk erroneously low. The postulate of a vital activity at the yolk membrane maintaining an osmotic pressure difference is thus shown to be unnecessary, since a simple osmotic equilibrium exists between the yolk and the white. PMID- 19872682 TI - AUTOMATIC RECORDING OF MOVEMENTS OF PLANT ORGANS. AB - An automatic photographic recording apparatus is described. It uses plates sensitized to the red end of the spectrum for recording movements of organs of plants which cannot be photographed in white light. It enables one to obtain two types of pictures: 1. A "standing plate" picture where the successive positions of the organ to be registered are superimposed on the same plate, no motion being imparted to the plate. 2. A "moving plate" picture where, by means of a clock controlled plate shifter, each successive picture is entirely separate from the preceding one. PMID- 19872683 TI - GEOTROPIC CURVATURE OF AVENA COLEOPTILES. AB - Applying a photographic recording method, and working on enlargements of the plates so obtained, the shape of the geotropically curving coleoptile of Avena was studied. This shape is expressed in terms of curvature of the neutral axis of the coleoptile; for the true geotropic response of the strain of Avena used, the curvature of the neutral axis is an arc of a circle. The "rate of curvature" is taken as the derivative of the curve relating time with the angle with the horizontal made by the tangent to the neutral axis at the tip. This rate increases up to a maximum and then decreases gradually. No "geogrowth" of the whole coleoptile is found. It is shown that the curvature is due to an increase in the elongation of the lower side of the horizontally placed coleoptile with a concomitant decrease of the rate of elongation of the upper side. This is correlated with a shift in distribution of "growth substance" in the tip as affected by change of position of the coleoptile. PMID- 19872684 TI - PROTOPLASMIC POTENTIALS IN HALICYSTIS : II. THE EFFECTS OF POTASSIUM ON TWO SPECIES WITH DIFFERENT SAPS. AB - The potential difference across the protoplasm of impaled cells of two American species of Halicystis is compared. The mean value for H. Osterhoutii is 68.4 mv.; that for H. ovalis is 79.7 mv., the sea water being positive to the sap in both. The higher potential of H. ovalis is apparently due to the higher concentration of KCl (0.3 M) in its vacuolar sap. When the KCl content of H. Osterhoutii sap (normally 0.01 M or less) is experimentally raised to 0.3 M, the potential rises to values about equal to those in H. ovalis. The external application of solutions high in potassium temporarily lowers the potential of both, probably by the high mobility of K(+) ions. But a large potential is soon regained, representing the characteristic potential of the protoplasm. This is about 20 mv. lower than in sea water. The accumulation of KCl in the sap of H. ovalis is apparently not due to the higher mobility of K(+) ion in its protoplasm, since the electrical effects of potassium are practically identical in H. Osterhoutii, where KCl is not accumulated. PMID- 19872685 TI - THE KINETICS OF PENETRATION : IV. DIFFUSION AGAINST A GROWING POTENTIAL GRADIENT IN MODELS. AB - In a model consisting of a non-aqueous layer (representing the protoplasm) placed between an inner, more acid, aqueous layer (representing the sap) and an outer, more alkaline, aqueous solution (representing the external solution bathing a living cell) the penetration of potassium creates an outwardly directed potential against which potassium continues to diffuse inward, thereby increasing the outward potential. This continues until the steady state is reached. The potassium sets up less potential in entering than in escaping and the net result is an outwardly directed potential. A similar process appears to take place in certain living cells. PMID- 19872686 TI - STUDIES IN RESPIROMETRY : II. INFLUENCE OF INFRA-RED RADIATION UPON CARBON DIOXIDE RESPIRATION OF DROSOPHILA IMAGOS IN DRY AIR. PMID- 19872687 TI - STUDIES IN RESPIROMETRY : III. AN APPLICATION OF REFRACTOVOLUMETRIC RESPIROMETRY TO THE OBSERVATION OF CONTINUOUS RESPIRATORY CHANGES IN WET OR DRY SYSTEMS. PMID- 19872688 TI - CRYSTALLINE PEPSIN : IV. HYDROLYSIS AND INACTIVATION BY ACID. AB - The decrease in protein nitrogen and in the activity of solutions of crystalline pepsin at pH 1.8 and 45 degrees C. has been determined. The decrease in activity, as measured with eleven different methods, is in exact proportion to the decrease of protein nitrogen of the solution. The measurements were continued until less than 5 per cent of the original protein remained. These results indicate that none of the split products of the protein molecule possess any appreciable activity compared to that of the original protein. PMID- 19872689 TI - PEPSIN ACTIVITY UNITS AND METHODS FOR DETERMINING PEPTIC ACTIVITY. AB - Experimental methods are described for determining the activity of pepsin preparations by means of changes in the viscosity of gelatin, casein, edestin, and powdered milk solutions, and by the rate of formation of non-protein nitrogen from casein and edestin solutions, or by the increase in formol titration of casein, edestin or gelatin. Activity units for pepsin are defined in terms of these measurements. PMID- 19872690 TI - STUDIES IN RESPIROMETRY : I. A COMBINED GAS BURETTE-INTERFEROMETER RESPIROMETER. AB - A machine has been described which combines volumetric and refractometric means of observing changes in carbon dioxide and oxygen concentrations and amounts in a closed system suitable for containing a respiring system. A means of thermoregulation has been described briefly. The theory upon which estimation is based has been outlined in considerable detail and generality; indicating how dependence upon absorption of gases by reagents can be eliminated completely, although they may be used in certain instances as a means of independent check. An experiment of this nature has been reported as an illustration of one use of the machine. Data of other experiments in which a moist environment was employed for the respiring system will be given in another communication. PMID- 19872691 TI - THE ESTIMATION OF PEPSIN WITH HEMOGLOBIN. PMID- 19872692 TI - TEMPERATURE CHARACTERISTIC FOR THE ANAEROBIC PRODUCTION OF CO(2) BY GERMINATING SEEDS OF LUPINUS ALBUS. AB - The rate of anaerobic production of CO(2) by germinating seeds of Lupinus albus was studied as a function of temperature between 7.5 degrees and 18 degrees C. The mean value for the temperature characteristic was found to be 21,500+/- calories, which is slightly lower than that for the same process under aerobic conditions (23,500+/- calories). The values for the individual micro's in the two cases overlap considerably. The possible identity of the processes underlying the production of CO(2) aerobically and anaerobically is discussed. PMID- 19872693 TI - DARK ADAPTATION AND THE DARK GROWTH RESPONSE OF PHYCOMYCES. AB - Light-adapted sporangiophores of the fungus Phycomyces respond to sudden darkening by a temporary decrease in the rate of elongation, after a latent period of several minutes. The reaction time of this "dark growth" response is compound like that of the "light growth" response. It is, moreover, shorter the more intense the previous illumination. The rate of dark adaptation following adaptation to a very large range of light intensities is found to be proportional to the logarithm of the preceding light intensity. It is shown that a constant amount of dark adaptation takes place before the response occurs. On the assumption that changes in the rate of growth reflect changes in the concentration of a substance which at constant light intensity is in equilibrium with a light-sensitive material, possible equations for such a photostationary state are examined. The most reasonable formulation requires that the partial velocity of the "light" reaction be taken proportional to log I instead of to I directly. PMID- 19872694 TI - PULSATION FREQUENCY OF THE ADVISCERAL AND ABVISCERAL HEART BEATS OF CIONA INTESTINALIS IN RELATION TO TEMPERATURE. AB - The frequency of pulsation of the heart of Ciona intestinalis increases with temperature in both advisceral and abvisceral direction, according to the Arrhenius equation. The increase in pulsation is the same in both directions. The following micro values were obtained: 8,000-, 12,000+, 16,000, in several combinations, with critical temperatures at 10 degrees , 15 degrees , and 20 degrees C. The values found are comparable with earlier findings for activity of the heart in different animals. This quantitative correspondence suggests anew the conception that temperature characteristics may be employed for recognition of controlling processes. The fact that the micro's and the critical temperature are the same for advisceral and abvisceral beats, indicates that the general metabolic condition of the two ends of the heart is the same in any one individual. PMID- 19872695 TI - THE MECHANISMS OF TROPISTIC REACTIONS AND THE STRYCHNINE EFFECT IN DAPHNIA. AB - 1. Experiments with strychnine were performed to test two assumptions important in the development of a theory for the mechanisms involved in the tropisms exhibited by Daphnia. 2. After a brief interval in strychnine solution Daphnia exhibits a reversal of the primary sign (a) of phototropism, from negative to positive; and (b) of galvanotropism, from anodic to cathodic. In both cases the orientation of the body remains the same. 3. The mechanism responsible for the sign of phototropism and galvanotropism in Daphnia is therefore distinct from that underlying orientation. 4. Evidence is obtained indicating that changes in sign of tropism, produced by changes in illumination or by subjection to strychnine, involve the control of antagonistic muscles in the swimming appendages which are reciprocally innervated. PMID- 19872696 TI - ON THE MEASURE OF EXCITABILITY. AB - Recent time-intensity data by Rushton (1932) on the sciatic nerve of the frog are shown to provide additional support to the writer's suggestion (1932, a) that integrals of the equation See PDF for Equation where V is the applied voltage, p is the local excitatory process and K and k are constants adequately represent the just effective direct current stimuli when the threshold value of p is made a linear function of the voltage of the form h +/- alpha V where h and alpha are constants. The measurement of excitability is discussed and it is shown that the criteria for "true" measurements are not likely to be found by the agreement of the data with canonical time-intensity functions as suggested by Lapicque (1931) but rather in the establishing of standard experimental conditions. These conditions may permit the use of chronaxie as a measure of excitability, but it seems more likely that the constant k of the above equation will have to be adopted. There is sufficient evidence to cast considerable doubt on the validity of any conclusions drawn from the existing measurements of chronaxie although those derived through a particular technique may be valid. The problem requires a thorough experimental investigation in terms of integrals of the above equation. PMID- 19872697 TI - ON THE EXCITATION OF TISSUE BY MEANS OF CONDENSER DISCHARGES. AB - Equations are derived for the capacity-voltage relations for stimulation of tissue by condenser discharges, using the hypothesis that the local excitatory process p grows under the influence of an applied potential V according to the equation, See PDF for Equation where K and k are constants. It is further assumed that the local excitatory process becomes adequate when it attains a value h +/- alpha V where h and alpha are constants and V is the applied potential at the particular instant that the adequate value is attained. The equations so obtained are applied to the data of several authors on several types of tissue and the agreements obtained are sufficiently good. It is shown in one case that the direct current equation and the condenser discharge equation each derived from the above bases are consistent when applied to data from the same preparation. PMID- 19872698 TI - THE PHOTOCHEMICAL REACTION IN PHOTOSYNTHESIS. AB - Measurements of photosynthesis were made in continuous and flashing light of high intensity, using cells varying in chlorophyll content. The amount of chlorophyll present per molecule of carbon dioxide reduced per single flash of light was found to be about 2480 molecules. The length of time required for one unit in the photosynthetic mechanism to complete the cycle of photochemical and Blackman reactions was found to be about 0.02 sec. at 25 degrees C. The equation R = AIN was shown to give a good description of the rate of the photochemical reaction, when A is a velocity constant, I the intensity of light, and N the number of units in the photosynthetic mechanism. PMID- 19872699 TI - THE EFFECTS OF RADIATIONS ON BIOLOGICAL SYSTEMS : I. INFLUENCE OF HIGH-FREQUENCY X-RAY RADIATION UPON THE DURATION OF THE PREPUPAL PERIOD OF DROSOPHILAE. AB - The effect of high-frequency x-ray irradiation in prolongation of the larval stage of Drosophila melanogaster has been studied further, and evidence presented of the attainment of a maximum effect followed by a decrease to an almost level plateau in the course curve of average (median) prepupal period (phi) as a function of the period of irradiation (t) under otherwise fixed conditions. The variation of effects of the experimental treatment with age of the larvae at the time of irradiation has been demonstrated in both control and irradiated lots, and a strikingly decreased effect observed when ventilation was not supplied as usual. Means of employment of a living system of this type as an indicator of effectiveness of radiation as in phantom depth or other distributional experiments have been presented and their use illustrated. PMID- 19872700 TI - A STUDY OF THE EFFECTS OF CERTAIN VARIATIONS IN PREPARATION OF A STARCH SUBSTRATE IN AMYLASE VISCOSIMETRY. AB - The results of employing different concentrations of starch and starch from different lots as substrates in the viscosimetric estimation of amylase concentration have been compared with the object of ultimate attainment of reproducible standards, independent of successive comparison. PMID- 19872701 TI - A REPRODUCIBLE STANDARD SUBSTRATE IN STARCH-AMYLASE VISCOSIMETRY. PMID- 19872702 TI - SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II. AB - 1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H(+)) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen's alpha glucosidase (maltase), was found. PMID- 19872703 TI - FACTORS INVOLVED IN THE USE OF ORGANIC SOLVENTS AS PRECIPITATING AND DRYING AGENTS OF IMMUNE SERA. AB - 1. In concentrations of 70 to 75 per cent the organic solvents methyl, ethyl, and propyl alcohols, and acetone cause complete precipitation of serum proteins and produce maximum loss in solubility. We have referred to this concentration range as the critical concentration. 2. As the concentration of the solvents is increased from about 75 per cent precipitation continues complete but loss in solubility progressively decreases until at all concentrations above about 87 per cent the precipitates formed at room temperature are completely soluble. 3. The degree of resolubility of the precipitates formed even in these high concentrations of the organic solvent decreases as the temperature is raised and as the duration of exposure is increased. 4. At 5 degrees C. the precipitates formed in all concentrations of these organic solvents are completely resoluble. Also these solvents exert maximum precipitating effect at lower temperature. 5. Maximum precipitating effect by these organic solvents occurs at about pH 6.0 precipitation becoming progressively less as the pH value is altered either way from this point. 6. The more concentrated the serum, the greater the proportion of protein present that will be precipitated by any given concentrations of organic solvent. 7. A method for preparing dry immune sera has been given. Such dried sera have been extracted with a number of organic compounds without loss in solubility or antibody activity. PMID- 19872704 TI - THE EFFECT OF TEMPERATURE ON THE TITRATION CURVE OF CASEIN. AB - The influence of temperature on the titration curve of casein may be accounted for by the Bjerrum theory of ionization of ampholytes. PMID- 19872705 TI - CRYSTALLINE TRYPSIN : I. ISOLATION AND TESTS OF PURITY. PMID- 19872706 TI - CRYSTALLINE TRYPSIN : II. GENERAL PROPERTIES. AB - A method is described for isolating a crystalline protein of high tryptic activity from beef pancreas. The protein has constant proteolytic activity and optical activity under various conditions and no indication of further fractionation could be obtained. The loss in activity corresponds to the decrease in native protein when the protein is denatured by heat, digested by pepsin, or hydrolyzed in dilute alkali. The enzyme digests casein, gelatin, edestin, and denatured hemoglobin, but not native hemoglobin. It accelerates the coagulation of blood but has little effect on the clotting of milk. It digests peptone prepared by the action of pepsin on casein, edestin or gelatin. The extent of the digestion of gelatin caused by this enzyme is the same as that caused by crystalline pepsin and is approximately equivalent to tripling the number of carboxyl groups present in the solution. The activity of the preparation is not increased by enterokinase. The molecular weight by osmotic pressure measure is about 34,000. The diffusion coefficient in (1/2) saturated magnesium sulfate at 6 degrees C. is 0.020 +/-0.001 cm.(2) per day, corresponding to a molecular radius of 2.6 x 10(-7) cm. The isoelectric point is probably between pH 7.0 and pH 8.0. The optimum pH for the digestion of casein is from 8.0-9.0. The optimum stability is at pH 1.8. PMID- 19872707 TI - CRYSTALLINE TRYPSIN : III. EXPERIMENTAL PROCEDURE AND METHODS OF MEASURING ACTIVITY. PMID- 19872708 TI - CRYSTALLINE TRYPSIN : IV. REVERSIBILITY OF THE INACTIVATION AND DENATURATION OF TRYPSIN BY HEAT. AB - 1. If dilute solutions of purified trypsin of low salt concentration at pH from 1 to 7 are heated to 100 degrees C. for 1 to 5 minutes and then cooled to 20 degrees C. there is no loss of activity or formation of denatured protein. If the hot trypsin solution is added directly to cold salt solution, on the other hand, all the protein precipitates and the supernatant solution is inactive. 2. The per cent of the total protein and activity present in the soluble form decreases from 100 per cent to zero as the temperature is raised from 20 degrees C. to 60 degrees C. and increases again from zero to 100 per cent as the solution is cooled from 60 degrees C. to 20 degrees C. The per cent of the total protein present in the soluble (native) form at any one temperature is nearly the same whether the temperature is reached from above or below. 3. If trypsin solutions at pH 7 are heated for increasing lengths of time at various temperatures and analyzed for total activity and total protein nitrogen after cooling, and for soluble activity and soluble (native) protein nitrogen, it is found that the soluble activity and soluble protein nitrogen decrease more and more rapidly as the temperature is raised, in agreement with the usual effects of temperature on the denaturation of protein. The total protein and total activity, on the other hand, decrease more and more rapidly up to about 70 degrees C. but as the temperature is raised above this there is less rapid change in the total protein or total activity and at 92 degrees C. the solutions are much more stable than at 42 degrees C. 4. Casein and peptone are not digested by trypsin at 100 degrees C. but when this digestion mixture is cooled to 35 degrees C. rapid digestion occurs. A solution of trypsin at 100 degrees C. added to peptone solution at zero degree digests the peptone much less rapidly than it does if the trypsin solution is allowed to cool slowly before adding it to the peptone solution. 5. The precipitate of insoluble protein obtained from adding hot trypsin solutions to cold salt solutions contains the S-S groups in free form as is usual for denatured protein. 6. The results show that there is an equilibrium between native and denatured trypsin protein the extent of which is determined by the temperature. Above 60 degrees C. the protein is in the denatured and inactive form and below 20 degrees C. it is in the native and active form. The equilibrium is attained rapidly. The results also show that the formation of denatured protein is proportional to the loss in activity and that the re-formation of native protein is proportional to the recovery of activity of the enzyme. This is strong evidence for the conclusion that the proteolytic activity of the preparation is a property of the native protein molecule. PMID- 19872709 TI - CRYSTALLINE TRYPSIN : V. KINETICS OF THE DIGESTION OF PROTEINS WITH CRUDE AND CRYSTALLINE TRYPSIN. AB - The rate of digestion, as determined by the increase in non-protein nitrogen or formol titration, of casein, gelatin, and hemoglobin with crystalline trypsin preparations increases nearly in proportion to the concentration of protein, but with crude pancreatic extract the rate of digestion becomes independent of the protein concentration in concentrations of more than 2.5 per cent. With both enzymes the rate of digestion of mixtures of 5 per cent casein and gelatin is greater than would be expected from the point of view of a compound between enzyme and substrate. The rate of digestion of 5 per cent casein in the presence of 5 per cent gelatin is exactly the same as that of 5 per cent casein alone. This result is obtained with both enzymes. The digestion of casein with crude trypsin follows the course of a monomolecular reaction quite closely while with purified trypsin the velocity constant decreases as the reaction proceeds. In the case of hemoglobin the monomolecular velocity constant decreases with both purified and crude enzyme. When the reaction is followed by changes in the viscosity of the solution the abnormal effect of changing substrate concentration disappears and the reaction is in fair agreement with the monomolecular equation. The results as a whole indicate that the abnormalities of the reaction are due to the occurrence of several consecutive reactions rather than to the formation of a substrate enzyme compound. PMID- 19872710 TI - PHOTOKINESIS AND TONIC EFFECT OF LIGHT IN UNIONICOLA. AB - 1. The speed of progression of Unionicola, a water mite, is influenced by light; and over a certain range increases as a function of the light intensity. 2. The relation between speed and light intensity is not a simple one, as the speed of progression is due to the combined effect of amplitude of steps and frequency of leg movement. 3. The amplitude of stride increases in direct proportion to the logarithm of the light intensity, while the frequency of stepping has no such simple relation to intensity. 4. The change in length of stride with changing light intensity indicates a tonic effect of light on the locomotor muscles. Such an effect has been observed previously in studies of orientation, due to unequal illumination, which produces changes in posture. PMID- 19872711 TI - THE COMBINATION OF CERTAIN PROTEINS WITH HYDROCHLORIC ACID. AB - Electromotive force measurements of cells without liquid junction, of the type Ag, AgCl, HCl + protein, H(2), have been made at 30 degrees C. with the proteins gelatin, edestin, and casein in 0.1 M hydrochloric acid. The data are consistent with the assumptions of a constant combining capacity of each protein for hydrogen ion, no combination with chloride ion, and Failey's principle of a linear variation of the logarithm of the mean activity coefficient of the acid with increasing protein concentration. The combining capacities for hydrogen ion so obtained are 13.4 x 10(-4) for edestin, 9.6 x 10(-4) for gelatin, and 8.0 x 10(-4) for casein, in equivalents of combined H(+) per gm. of protein. PMID- 19872712 TI - ON TEMPERATURE CHARACTERISTICS FOR DIFFERENT PROCESSES IN THE SAME ORGANISM. AB - The temperature characteristics (micro) for two activities (heart beat and respiratory movements) studied simultaneously in the same individual organism (Daphnia magna) were always found to differ in magnitude. The type of graph obtained when the frequency of these movements was plotted according to the Arrhenius equation was also distinctly different for each activity. The organism therefore does not determine a uniform magnitude of the temperature characteristic for each of its activities; the values of micro must therefore have, to this extent, a local, specific meaning. PMID- 19872713 TI - BIOELECTRIC POTENTIALS IN VALONIA : THE EFFECT OF SUBSTITUTING KCl FOR NaCl IN ARTIFICIAL SEA WATER. AB - The P.D. across the protoplasm of Valonia macrophysa has been studied while the cells were exposed to artificial solutions resembling sea water in which the concentration of KCl was varied from 0 to 0.500 mol per liter. The P.D. across the protoplasm is decreased by lowering and increased by raising the concentration of KCl in the external solution. Changes in P.D. with time when the cell is treated with KCl-rich sea water resemble those observed with cells exposed to Valonia sap. Varying the reaction of natural sea water from pH 5 to pH 10 has no appreciable effect on the P.D. across Valonia protoplasm. Similarly, varying the pH of KCl-rich sea water within these limits does not alter the height of the first maximum in the P.D.-time curve. The subsequent behavior of the P.D., however, is considerably affected by the pH of the KCl-rich sea water. These changes in the shape of the P.D.-time curve have been interpreted as indicating that potassium enters Valonia protoplasm more rapidly from alkaline than from acidified KCl-rich sea water. This conclusion is discussed in relation to certain theories which have been proposed to explain the accumulation of KCl in Valonia sap. The initial rise in P.D. when a Valonia cell is transferred from natural sea water to KCl-rich sea water has been correlated with the concentrations of KCl in the sea waters. It is assumed that the observed P.D. change represents a diffusion potential in the external surface layer of the protoplasm, where the relative mobilities of ions may be supposed to differ greatly from their values in water. Starting with either Planck's or Henderson's formula, an equation has been derived which expresses satisfactorily the observed relationship between P.D. change and concentration of KCl. The constants of this equation are interpreted as the relative mobilities of K(+), Na(+), and Cl(-) in the outer surface layer of the protoplasm. The apparent relative mobility of K(+) has been calculated by inserting in this equation the values for the relative mobilities of Na(+) (0.20) and Cl(-) (1.00) determined from earlier measurements of concentration effect with natural sea water. The average value for the relative mobility of K(+) is found to be about 20. The relative mobility may vary considerably among different individual cells, and sometimes also in the same individual under different conditions. Calculation of the observed P.D. changes as phase-boundary potentials proved unsatisfactory. PMID- 19872714 TI - THE ACTION OF X-RAYS ON EUPLOTES TAYLORI AND ASSOCIATED BACTERIA. AB - 1. The minimum lethal dose of x-rays for Euplotes taylori was determined. Under the conditions of this investigation a 220 second exposure (2110 Roentgen units per second) was required to kill the protozoon. Much less exposure was sufficient to kill the associated bacteria. This difference in resistance permits the sterilization of protozoa with comparative ease. 2. Irradiation of Euplotes for 100 to 220 seconds caused a complete but temporary cessation of ciliary activity in many of the organisms, the percentage so affected increasing with the length of irradiation. 3. Pure cultures of Pseudomonas fluorescens and Bacillus coli, K(13), separately irradiated, were found to be killed much more readily than protozoa,-the former in 15 seconds exposure (2530 Roentgen units per second) and the latter in 45 seconds. 4. The death of these organisms by irradiation was not due to the action of toxic products in the medium since separately irradiated media were not found to be toxic. 5. Irradiated bacteria were found unsatisfactory for the nutrition of Euplotes, previously sterilized either by irradiation or washing. PMID- 19872715 TI - THE VISUAL INTENSITY DISCRIMINATION OF THE HONEY BEE. AB - 1. Bees respond by a characteristic reflex to a movement in their visual field. By confining the field to a series of parallel stripes of different brightness it is possible to determine at any brightness of one of the two stripe systems the brightness of the second at which the bee will first respond to a displacement of the field. Thus intensity discrimination can be determined. 2. The discriminating power of the bee's eye varies with illumination in much the same way that it does for the human eye. The discrimination is poor at low illumination; as the intensity of illumination increases the discrimination increases and seems to reach a constant level at high illuminations. 3. The probable error of See PDF for Equation decreases with increasing I exactly in the same way as does See PDF for Equation itself. The logarithm of the probable error of DeltaI is a rectilinear function of log I for all but the very lowest intensities. Such relationships show that the measurements exhibit an internal self-consistency which is beyond accident. 4. A comparison of the efficiency of the bee's eye with that of the human eye shows that the range over which the human eye can perceive and discriminate different brightnesses is very much greater than for the bee's eye. When the discrimination power of the human eye has reached almost a constant maximal level the bee's discrimination is still very poor, and at an illumination where as well the discrimination power of the human eye and the bee's eye are at their best, the intensity discrimination of the bee is twenty times worse than in the human eye. PMID- 19872716 TI - THE DISTRIBUTION OF THE ACTION CURRENTS PRODUCED BY HEART MUSCLE AND OTHER EXCITABLE TISSUES IMMERSED IN EXTENSIVE CONDUCTING MEDIA. AB - The action currents produced by heart muscle and other tissues immersed in or in contact with a large body of conducting material are distributed in accordance with the laws that govern the flow of electric currents in volume conductors. The curve obtained when one electrode (the exploring electrode) is placed very close to and the other (the indifferent electrode) very far from the active tissue may be regarded as representing the potential variations of the exploring electrode alone; the. potential of the indifferent electrode is by comparison nearly constant. Curves obtained by this method of leading from the surface of the mammalian auricle indicate that the electrical effects produced by the passage of the excitation wave along a single muscle fiber are nearly the same as those that would occur if the crest of this wave were immediately preceded by a source and followed by a sink. A study of the electric field of a polarized membrane immersed in a volume conductor shows that this conclusion may be derived on theoretical grounds from the membrane theory of Bernstein. PMID- 19872717 TI - ELECTROKINETIC PHENOMENA : X. ELECTRIC MOBILITY AND CHARGE OF PROTEINS IN ALCOHOL WATER MIXTURES. AB - 1. The electrophoretic velocities of gelatin-, egg-albumin-, and gliadin-covered quartz particles in various alcohol-water solutions are, within the limits employed in usual experimental procedures, proportional to the field strength. 2. The electrophoretic mobilities of small, irregularly shaped quartz particles covered with an adsorbed film of protein in alcohol-water solutions are equal to the electroosmotic mobilities of the liquid past similarly coated flat surfaces. Hence the size and shape of such particles does not influence their mobilities, which depend entirely on the protein film. 3. The corrected mobility and hence presumably the charge of gelatin-covered quartz particles in solutions containing 35 per cent ethyl alcohol is proportional to the combining power of the gelatin; therefore the gelatin is adsorbed with the active groups oriented toward the liquid. The same is true in 60 per cent alcohol. 4. The charge calculated by means of the Debye-Henry approximation from the mobility of gelatin in solutions containing up to 35 per cent ethyl alcohol is, in the neighborhood of the isoelectric point, proportional to the combining power of the gelatin. Therefore the dielectric constant and the viscosity of the bulk of the medium may be used in the Debye-Henry approximation Q = 6 pi eta r v(m) (1 + kappa r) to predict changes in charge from mobility. 5. In the neighborhood of the isoelectric point gelatin is probably completely ionized in buffered ethyl alcohol-water mixtures up to 60 per cent alcohol. 6. In the presence of ethyl alcohol the isoelectric point of gelatin is shifted toward smaller hydrogen ion activities. This shift, like that caused by alcohol in the isoelectric points of certain amino acids, is approximately linearly related to the dielectric constant of the medium. PMID- 19872718 TI - ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : IV. CHAETOPTERHS AND ARBACIA PUNCTULATA. AB - 1. Unfertilized eggs of Chaetopterus consume about 2.4 mm.(3) O(2) per hour per 10 mm.(3) eggs at 21 degrees C. 2. In the 1st hour after fertilization, the fertilized eggs consume oxygen at about 53 or 54 per cent of this rate, which is about 1.3 mm.(3) O(2) per hour per 10 mm.(3) eggs at 21 degrees C. 3. For the first 6 hours after fertilization, at 21 degrees C., the curve of the rate of oxygen consumption is slightly asymmetrically sigmoid. The prefertilization rate is regained between 4(1/2) and 5 hours after fertilization. Soon after 6 hours, ciliary activity begins, and the rate of oxygen consumption rises rapidly. 4. The unfertilized eggs of Arbacia punctulata consume about 0.36-0.5 mm.(3) O(2) per hour per 10 mm.(3) eggs at 21 degrees C. The absolute determination is difficult as these eggs are highly sensitive to shaking in the manometer vessels, and these difficulties are discussed. 5. The fertilized eggs of Arbacia punctulata consume oxygen at the rate of about 2.0 mm.(3) O(2) per hour per 10 mm.(3) 21 degrees C. At 1 hour after fertilization the rate is already rising. 6. A comparison of the absolute rates of oxygen consumption, and the changes in rate at fertilization of these and a number of other eggs, together with a theoretical discussion, and a discussion of discrepancies in measurements on the eggs of Arbacia punctulata, is contained in the fifth paper of this series (21). PMID- 19872719 TI - ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : V. COMPARISONS AND INTERPRETATION. AB - 1. The rate of oxygen consumption by eggs may not merely undergo no change at fertilization, as in the case of the starfish, but it decreases to about half in Chaetopterus and in Cumingia. 2. The absolute rate of oxygen consumption in mm.(3) O(2) per hour per 10 mm.(3) eggs differs widely in several species of unfertilized eggs. It is very low in the sea urchin, intermediary in Nereis, and high in Chaetopterus and Cumingia. The range for these eggs is approximately 0.4 to 3.1 mm.(3) O(2) per hour per 10 mm.(3) eggs at 21 degrees C., in the ratio of about 1:8. 3. The absolute rates of oxygen consumption by the same fertilized eggs are much more nearly the same. They lie within the range 1.3 to 2.0 mm.(3) O(2) per hour per 10 mm.(3) eggs at 21 degrees C., in the ratio of approximately 1:1.5. Within this same range lie the values obtained by a number of investigators using a variety of eggs of invertebrates from several phyla. Amoeba proteus and frog skin also are within this range (see Fig. 2). 4. The changes in rate of oxygen consumption at fertilization by the different species of eggs, differing both in direction and magnitude, appear to be such as to bring the rate, when development is initiated, to about the same rate, which is also the rate of other comparable normally growing cells. 5. The direction and magnitude of the change in rate at fertilization therefore appears in the cases cited to be primarily a function of the absolute rate of oxygen consumption by the unfertilized eggs, which are characterized in their peculiar inhibited condition, among other things, by a wide range of respiratory rates. 6. It is not to be supposed that this range of rates will apply at all universally to eggs, especially to eggs of extremes in proportional content of inert materials, such as large yolky eggs. Fish and amphibian eggs for example respire at a much lower rate per unit volume. The effect on surface: volume ratios attending extremes of cell size might also be expected to shift the absolute rate. 7. The absolute rate of oxygen consumption by the eggs of the alga Fucus vesiculosus is considerably higher than the rates of the animal eggs measured. It is of the same order of magnitude as the rates of several other small-celled algae, which respire at a greater rate per unit volume than most non-motile animal cells. 8. The comparatively high rates of oxygen consumption by the inhibited (unfertilized) eggs of Chaetopterus and Cumingia are not directly associated with nuclear or morphological activity of the cell since they continue at the high rate for hours after cessation of the brief initial nuclear activity, which takes place when the eggs are placed in sea water. 9. It is concluded that the rate of oxygen consumption is not necessarily and probably not generally the limiting factor which causes inhibition of the unfertilized egg. Increase in rate of oxygen consumption is not directly related to the initiation of development, in general, nor even necessarily concomitant. It is not improbable that the low rate of oxygen consumption is an immediate part of the cause of inhibition of the unfertilized sea urchin egg, but this is a special case. 10. This thesis, that the rate of oxygen consumption is not necessarily nor ordinarily the limiting factor in the inhibition of the unfertilized egg, and conversely that increase in the rate of oxygen consumption is not usually the essential feature of fertilization, is quite in agreement with the general relations between the rate of oxygen consumption on the one hand and anesthesia, growth, and development on the other in fertilized eggs and other organisms. 11. This conclusion is opposed to Loeb's explanation of the essential feature of fertilization, as an increase in oxidation rate or more strictly to generalization of his hypothesis to include eggs other than those of the sea urchins (or of other similar special cases which may be discovered). It extends to fertilization (the initiation of development) his and Wasteney's well established conclusion that "oxidation is not the independent variable in development." 12. It is suggested that the crux of the problem of fertilization lies in the nature of the inhibition of the unfertilized egg. Certain similarities between this condition, arrived at spontaneously in the case of the egg cell, and the condition of cells in narcosis or anesthesia are pointed out. 13. Although the rate of oxygen consumption by the unfertilized eggs of Chaetopterus and Cumingia cannot be regarded as the limiting factor which causes the inhibition of the eggs, in these and other cases with different absolute rates, it appears highly probable that the rate of oxygen consumption is in some way, at present obscure, tied up with or related to the condition of inhibition. This seems probable especially in view of the sharp change in rate which in most cases immediately attends cessation of the inhibition, but the relationship may be a non-causal one, as in narcosis. 14. It must be borne in mind that oxygen consumption is not necessarily a complete measure of oxidation, and that other measures such as of heat and metabolite production are necessary before the complete amount of oxidation is known. When these are completely worked out, if free energy relations are known, it is probable that more direct and inclusive relations may be found between oxidation, growth, development, and anesthesia. Generalization of Loeb's hypothesis, using "oxidation" in the broad sense might then turn out to hold, with fertilization fitting into the general scheme, but there is no basis for it at the present time. PMID- 19872720 TI - THE KINETICS OF PENETRATION : V. THE KINETICS OF A MODEL AS RELATED TO THE STEADY STATE. AB - An organic potassium salt, KG, passes from an aqueous phase, A, through a non aqueous layer, B, into a watery solution, C. In C it reacts with CO(2) to form KHCO(3). The ionic activity product (K) (G) in C is thus kept at such a low level that KG continues to diffuse into C after the concentration of potassium becomes greater in C than in A. Hence potassium accumulates in C, the osmotic pressure rises, and water goes in. A steady state is eventually reached in which potassium and water enter C in a constant ratio. The rate of entrance of potassium (with no water penetrating into C) may fall off in a manner approximately exponential. But water enters and may produce an exponential decrease in concentration. This suggests that the kinetics may be treated like that of two consecutive monomolecular reactions. Calculations made on this basis agree very well with the observed values. The rate of penetration appears to be proportional to the concentration gradient of KG in the non-aqueous layer and in consequence depends upon the partition coefficients which determine this gradient. Exchange of ions (passing as such through the non-aqueous layer) does not seem to play an important role in the entrance of potassium. The kinetics of the model may be similar to that of living cells. PMID- 19872721 TI - ULTRAFILTRATION : II. "BOUND" WATER (HYDRATION) OF BIOLOGICAL COLLOIDS. AB - Assuming that "bound" water loses its solvent properties, it is shown by an ultrafiltration method that in solutions of gelatin, casein, starch, and glycogen, and in blood serum, only a very small fraction of the water can be associated with the colloids in this form. PMID- 19872722 TI - SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. III. AB - 1. The relationship of sucrose and water concentration to invertase activity in vivo and in vitro has been studied under the same environmental conditions. 2. The sucroclastic activity of S. cerevisiae cells and of invertase solutions prepared from them reacts to changes in sucrose and water concentration in an identical manner. 3. The invertase contained in living yeast cells is just as freely exposed to the conditions of sucrose and water concentrations of the suspending medium as it would be if it were contained in a cell-free solution. Weight is added to the previous suggestion (2) that yeast invertase exerts its physiological activity in a region quite close to the surface of the cell. PMID- 19872723 TI - AN EXPERIMENTAL COMPARISON OF DIFFERENT CRITERIA OF DEATH IN YEAST. AB - Different criteria of death have been compared experimentally and quantitatively. Pure cultures of a yeast have been subjected to adverse conditions, and the number of dead cells, judged by different tests, has been determined in successive time intervals. The yeast cultures were exposed to heat, to HgCl(2), to ultraviolet light, and to x-rays. In each case, the cells lost the power of reproduction (measured by the plate count) most rapidly. The loss of fermentation (measured by the CO(2) pressure) was less rapid. Still slower was the change in staining reaction with methylene blue, and the loss of selective permeability of the plasma membrane (measured by the percentage of cells staining with Congo red). Slowest of all was the coagulation of protoplasm as observed in the dark field. In the case of death by heat or by HgCl(2), the rate of loss of reproduction was about twice as rapid as that of the loss of fermentation, about three times that of the loss of semipermeability, and about forty times as large as the rate of coagulation. With ultraviolet light and with x-rays, these ratios were decidedly different. The technique employed does not permit the conclusion that any one criterion of death is the prerequisite for other criteria. It does not appear probable that loss of reproduction is the prerequisite for loss of fermentation or of semipermeability because the ratios of the velocities of these processes are not the same with all causes of death. There is no evidence that cells may show certain criteria of death immediately after exposure, and recover later. PMID- 19872724 TI - ELECTROKINETIC PHENOMENA : XI. ACTION OF UNI-UNIVALENT ELECTROLYTES ON ELECTRIC MOBILITY OF PROTEINS. AB - By assuming that the electric charge of proteins is primarily determined by the hydrogen ion activity of the medium, and by making corrections when necessary for the effect of salt, it is possible to derive a simple relationship between the electric mobility of proteins and the effective reciprocal thickness of the electric double layer. The decrease in electric mobility of proteins in solutions is readily predicted for gelatin in acetate buffers and for egg albumin in the presence of the alkali halides, of acetate buffers, and of hydrochloric acid on the basis of the assumptions made. PMID- 19872725 TI - OSMOTIC RELATIONSHIPS IN THE HEN'S EGG. AB - Data have been given to illustrate the difficulty of obtaining consistent freezing point data with a viscous fluid such as the yolk of the hen's egg and a technique has been described for obtaining reproducible and accurate results consistently. Further freezing point data have been given which were obtained with both fertile and unfertile hen's eggs by the use of a freezing point method previously described by the writer. These data show that there is a pronounced difference between the freezing points of the yolk and the white in contrast to data obtained by the use of the same method by Howard who found the freezing points of the yolk and the white to be the same. It was shown by freezing point determinations that even in a mixture of yolk and white osmotic equilibrium is slowly arrived at. This again emphasizes the fact established by Smith and Shepherd that since osmotic equilibrium between yolk and white is slowly arrived at, the postulation of a vital activity at the yolk membrane is unnecessary, since the steady state previously postulated need not be assumed to exist. PMID- 19872726 TI - CRYSTALLINE PEPSIN : V. ISOLATION OF CRYSTALLINE PEPSIN FROM BOVINE GASTRIC JUICE. AB - 1. A method has been described for isolating a crystalline protein with high proteolytic activity from bovine gastric juice by means of precipitation with magnesium sulfate and fractionation of the precipitate with acetone and magnesium sulfate. 2. The crystalline protein obtained in this way has the same crystalline form, optical activity, and specific activity, as determined by a number of methods, as does the crystalline protein previously isolated from swine gastric mucosa. 3. The solubility of the two preparations, however, is additive so that they are different although very closely related proteins. PMID- 19872727 TI - THE PROCESS OF PHAGOCYTOSIS : THE AGREEMENT BETWEEN DIRECT OBSERVATION AND DEDUCTIONS FROM THEORY. AB - The phagocyte, then, is a complex system delicately responsive to internal and external influences. Interfacial tensions, and under certain conditions viscosity, are critical factors in determining the ingestion of particles with which the phagocyte has come into contact. Deductions from the formulation of these factors by Fenn and Ponder are in agreement with observation and with experimental analysis. However, other and still unformulated forces also enter into the behavior of these remarkable cells. PMID- 19872728 TI - THE CHARACTERISTICS OF ULTRAFILTRATES OF PLASMA. AB - 1. Calculations from the Fick diffusion law are shown to predict that membrane equilibria should be established during the course of ultrafiltration. 2. It is shown that the chloride ion is more concentrated and the sodium ion less concentrated in the ultrafiltrate than in the plasma from which the ultrafiltrate was derived. 3. It has been found that by increasing the base bound by protein through a reduction in the bicarbonate content the difference between the plasma concentration and the ultrafiltrate concentration for the several ions studied increases. 4. Calculations from the Donnan equation as to the magnitude of the change in base bound by protein at differing hydrogen ion concentrations are in substantial agreement with the observed values, thus rendering it probable that the membrane equilibrium effect is responsible for the change in distribution ratios observed. 5. It is pointed out that the observed difference in the distribution ratio of cations from that of the chloride anion is probably to be explained by the influence of protein in lowering the activity coefficient of cations when on the alkaline side of the isoelectric point. 6. It is pointed out that account must be taken of these observations in any consideration of the role of ultrafiltration in the production of any secretion or body fluid. PMID- 19872729 TI - THE EFFECT OF CYANIDE AND OF VARIATION IN ALKALINITY ON THE OXIDATION-REDUCTION POTENTIAL OF THE HEMOGLOBIN-METHEMOGLOBIN SYSTEM. AB - The potentiometric method was applied to the study of the influence of cyanide and of hydroxyl ion on methemoglobin. Both of these ions appear to combine with the iron of the methemoglobin molecule and reduce its oxidant activity. From the magnitude of the effect produced by cyanide and by variation in pH on the oxidation-reduction potential of the methemoglobin-hemoglobin system, it is concluded that cyanmethemoglobin and alkaline methemoglobin are undissociated ferric compounds, the first with cyanide and the second with hydroxyl. Electronic formulas, based on the electrical properties of the hemoglobin derivatives, are suggested. PMID- 19872730 TI - STIMULATION BY THE MINERAL ACIDS, HYDROCHLORIC, SULFURIC, AND NITRIC, IN THE SUNFISH EUPOMOTIS. AB - 1. The stimulating efficiency of hydrochloric, sulfuric, and nitric acids has been measured in the sunfish Eupomotis gibbosus, by a method which reduces experimental errors to a minimum. 2. The results show that stimulation by these acids is primarily dependent upon the (H(+)) produced in the animal's aquatic environment, and that the reaction time is a logarithmic function of the (H(+)) within the range tested expressed by the equation: (RT-5) = -4.3 log (H(+) x 10(4)) + 9.118. 3. Any effect of the chloride, sulfate, and nitrate ions must itself be measured by the (H(+)). 4. Variation in the reaction time is also a logarithmic function of the (H(+)), and the percentage variation is independent of the (H(+)) over the range tested. 5. Freshly collected fish show a lower threshold for stimulation as determined by the (H(+)) than do fish adapted to laboratory conditions, but relatively the reaction times of the two groups are the same. PMID- 19872731 TI - SPECIFIC NERVE IMPULSES FROM GUSTATORY AND TACTILE RECEPTORS IN CATFISH. AB - 1. Receptors in the lips and barbels of the catfish Ameiurus nebulosus Les. are very sensitive to mechanical stimuli, giving large rapid (A-type) impulses in fibers of the facial nerve in response to touching the receptive surfaces and to movements of the water in which the preparation is immersed. 2. The great sensitivity of the barbels and lips to currents of water and the bilateral symmetry of the distribution of sensitivity of the facial nerve may serve as a basis for observed rheotropic orientation in the catfish. 3. Acetic acid, NaCl, and meat juice, dissolved in the water bathing the barbels and lips, set up impulses of very small and barely detectable potential in the fibers of the facial nerve. 4. It is suggested that the specificity of impulses for the two sense modalities may be correlated with the large size of the cells of origin of the axons in the Gasserian ganglion supplying tactile receptors and the small size of the cells of origin in the geniculate ganglion sending axons to taste buds. PMID- 19872732 TI - ELECTRICAL RESPONSES FROM THE LATERAL-LINE NERVES OF CATFISH. I. AB - 1. Records of impulses from the lateral-line nerves of catfish show that the lateral-line organs are in a state of continuous activity, producing a massive discharge of impulses. 2. The discharge may be increased during the direct application of pressure on the skin over the lateral-line canal, by ripples in the water, by irregular currents of water, and by movements of the fish's trunk. 3. The asynchronously discharging lateral-line organs respond to vibratory stimuli from tuning-forks by getting into phase with each other and by beating synchronously at frequencies ranging from 20 to 70 per second. The frequency of beating for a given preparation is independent of the frequency of the tuning fork for the fork frequencies of 100, 200, and 250 double vibrations which were used. 4. The continuous discharge of the lateral-line system is markedly changed by alteration of temperature. The frequency declines on lowering the temperature and rises on increasing it. Spinal and facial nerves in the catfish fail to yield nerve impulses in response to changes of the skin temperature between 0 degrees and 28 degrees C., although the intact animal is known to be sensitive to temperature differences. 5. The action of the lateral-line system of Ameiurus in inhibiting responses initiated through the skin and ears (Parker and Van Heusen, 1917) is discussed in the light of the present experiments. PMID- 19872733 TI - QUANTITATIVE ANALYSIS OF RESPONSES FROM LATERAL-LINE NERVES OF FISHES. II. AB - 1. The lateral-line nerves of trout as well as those of catfish are found to discharge impulses spontaneously at a high frequency. 2. The frequency of nerve impulse discharge is measured as a function of the number of participating receptor groups (lateral-line sense organs). A quantitative analysis is made of the contribution to the total response made by each group of sense organs. 3. An analysis of the variability of the response is presented which makes it possible to estimate quantitatively the longitudinal extent of damage to the neuromasts due to surgical manipulation. 4. A method is described for recording the response of a single nerve fiber in the lateral-line trunk. 5. The frequency of the spontaneous discharge from the lateral-line nerve trunk when plotted as a function of temperature according to the Arrhenius equation yields a temperature characteristic of approximately 5000 calories. 6. The variability of the frequency of response as a function of temperature indicates the existence of temperature thresholds for the spontaneous activity of the neuromasts. 7. A possible basis for the spontaneous activity is considered. It is pointed out that the lateral-line system may serve as a model of the Purkinje cells of the cerebellum. PMID- 19872734 TI - "GROWTH-PROMOTING SUBSTANCE" AND ELONGATION OF ROOTS. AB - The vertical elongation of normal roots of Lupinus seedlings proceeds at constant rate over periods of 4 to 5 hours. The decapitation of a root stops its elongation for a variable length of time, followed by a period of renewed elongation at a rate lower than that of the normal root. The tipping of the decapitated root with a tip of a coleoptile of Zea induces a decrease in the rate of elongation of the root. The same effect can be obtained with the diffusate from tips of coleoptile of Avena and to a lesser extent with diffusate of root tips. The reduction in the rate of elongation of the root determined by diffusate from the lower half of the tip of a coleoptile placed horizontally is more pronounced than the inhibition elicited by the diffusate of the upper half of the same tip. Various experiments with the diffusate of tips support the idea that under the conditions used the growth-promoting substance of the coleoptile tip or root tip inhibits the elongation of the decapitated root. PMID- 19872735 TI - AN ATTEMPT AT PEPTIC SYNTHESIS OF INSULIN. AB - 1. Synthesis of plastein from the products of peptic hydrolysis of small quantities of egg albumin can be demonstrated with amorphous or crystalline pepsin. 2. Synthesis of plastein from the products of peptic hydrolysis of amorphous or crystalline insulin can be demonstrated with amorphous or crystalline pepsin. 3. The plastein synthesised by pepsin from the products of peptic hydrolysis of insulin is physiologically inactive. 4. The plastein formed in the insulin experiments could not be crystallised by the methods used for the crystallisation of insulin. 5. The physiological activity of insulin is not destroyed by repeated freezing (at about -50 degrees C.) and melting of an aqueous or an alcoholic solution of this hormone. 6. No marked decrease in the physiological activity of insulin after incubation at 37 degrees C. with pepsin at pH 4.0, in dilute or concentrated solutions, was detected. PMID- 19872736 TI - THERMOSTAT FOR LOWER TEMPERATURES. AB - Details are given concerning the construction and operation of relatively simple thermostats which permit maintaining precise temperatures down to 0 degrees C. (with water), or temperatures above that of the ordinary room, and in which the temperature may be quickly altered at short intervals to new levels. PMID- 19872737 TI - THE DIGESTION AND INACTIVATION OF MALTASE BY TRYPSIN AND THE SPECIFICITY OF MALTASES. AB - 1. The maltase of saliva and that of E. coli (B. coli communis) hydrolyze maltose but not alpha-methylglucoside or sucrose and are therefore to be considered glucomaltases. 2. Maltase is rapidly and completely inactivated and digested by trypsin. PMID- 19872738 TI - ON THE RELATION BETWEEN MEASUREMENTS OF INTENSITY DISCRIMINATION AND OF VISUAL ACUITY IN THE HONEY BEE. AB - 1. Bees respond by a characteristic reflex to a movement of their visual field. By confining the field to a series of parallel stripes of two alternating different brightnesses it is possible to determine for any width of stripe, at any brightness of one of the two sets of stripes, the brightness of the second at which the bee will first respond to a displacement of the field. Thus the relations between visual acuity and intensity discrimination can be studied. 2. For each width of stripe and visual angle subtended by the stripe the discrimination power of the bee's eye for different brightnesses was studied. For each visual acuity the intensity discrimination varies with illumination in a characteristic, consistent manner. The discrimination is poor at low illuminations; as the intensity of illumination increases the discrimination increases, and reaches a constant level at high illuminations. 3. From the intensity discrimination curves obtained at different visual acuities, visual acuity curves can be reconstructed for different values of DeltaI/I. The curves thus obtained are identical in form with the curve found previously by direct test for the relation between visual acuity and illumination. PMID- 19872739 TI - THE VARIABILITY OF INTENSITY DISCRIMINATION BY THE HONEY BEE IN RELATION TO VISUAL ACUITY. AB - Variation in the determined magnitudes of the difference in brightness between alternating members of a system of stripes requisite for the elicitation of a threshold response in bees shows that the intensity of excitation, as a function of width of stripe and of intensity of illumination, is determined by the intensity of illumination and by the frequency of occurrence of divisions between bright and less bright bars. The variation of DeltaI is limited by the intensity of excitation, so that the curves relating P.E. (DeltaI/I) have the same form in relation to I as do the curves for DeltaI/I. The limiting rule according to which P.E. DeltaI is a power function of I for stripes of maximum usable width is departed from more and more markedly, for lower intensities, as narrower stripes are employed. PMID- 19872740 TI - THE DIFFUSION COEFFICIENT OF CRYSTALLINE TRYPSIN. AB - The diffusion coefficient of crystalline trypsin in 0.5 saturated magnesium sulfate at 5 degrees C. is 0.020 +/-0.001 cm.(2) per day, corresponding to a molecular radius of 2.6 x 10(-7) cm. The rate of diffusion of the proteolytic activity is the same as that of the protein nitrogen, indicating that these two properties are held together in chemical combination and not in the form of an adsorption complex. PMID- 19872741 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. VII. AB - The intraperitoneal injection of standard young rats of race A with 2/5 cc. of adrenalin chloride 1:50,000 results in increased speed of geotropically oriented creeping upon an inclined surface. It was expected that the effect of such increased frequency of stepping must be analogous to that due to imposition of added loads carried by the rats during geotropic progression. This is verified. The curve connecting theta with log sin alpha is distorted, under adrenalin, so as to be comparable to that obtained with an added mass of approximately 2.5 gm. upon the young rat's saddle; the threshold slope of surface for orientation is accordingly lowered, from alpha = 20 degrees to alpha = 12.5 degrees ; at the new threshold slope of surface the mean orientation angle theta is the same as in the absence of adrenalin at the corresponding threshold slope of surface. The total variation of performance is significantly increased in the injected rats, and at given slope of surface the variation is slightly increased. The proportionate modifiable variation of response is quite unaffected by the distortion of the theta - alpha curve, and is the same as in standard young A rats untreated or carrying additional loads. It is pointed out that for the consideration of the problem as to whether a given experimental treatment, or a given natural situation, affects in any way the variation of performance of a living system, it is necessary to obtain indices of variability which involve the expression of variation of performance as a function of measured conditions governing the performance. PMID- 19872742 TI - THE RATE OF OXYGEN UTILIZATION BY YEAST AS RELATED TO TEMPERATURE. AB - Suspensions of the yeast Saccharomyces cerevisiae gave reproducible rates of O(2) uptake over a period of 6 months. The relation of rate of consumption of O(2) to temperature was tested over a wide range of temperatures, and the constant in the formulation of the relationship is found to be reproducible. The values of this constant (micro) have been obtained for five separate series of experiments by three methods of estimation. The variability of micro has the following magnitudes: the average deviation of a single determination expressed as per cent of the mean is +/-2 per cent in the range 30-15 degrees , and +/-0.8 per cent in the range 15-3 degrees C. This constancy of metabolic activity measured as a function of temperature can then be utilized for more precise investigations of processes controlling the velocity of oxidations of substrates, and of respiratory systems controlled by intracellular respiratory pigments. The data plotted according to the Arrhemus equation give average values of the constant micro as follows: for the range 35-30 degrees , micro = 8,290; 30-15 degrees , micro = 12,440 +/-290; 15-3 degrees , micro = 19,530 +/-154. The critical temperatures are at 29.0 degrees and 15.7 degrees C. A close similarity exists between these temperature characteristics (micro) and values in the series usually obtained for respiratory activities in other organisms. This fact supports the view that a common system of processes controls the velocities of physiological activities in yeast and in other organisms. PMID- 19872743 TI - DEVELOPMENT OF THE EGG OF THE MACKEREL AT DIFFERENT CONSTANT TEMPERATURES. AB - 1. Mackerel egg development was followed to hatching at constant temperatures of 10 degrees , 11 degrees , 12 degrees , 13 degrees , 14 degrees , 15 degrees , 16 degrees , 17 degrees , 18 degrees , 19 degrees , 20 degrees , 21 degrees , 22 degrees , and 24 degrees C. Experiment showed that typical development could be realized only between 11 degrees and 21 degrees . 2. The length of the developmental period increases from 49.5 hours to 207 hours when the temperature is lowered from 21 degrees to 10 degrees C. 3. The calculated micro for the development of the mackerel egg is about 19,000 at temperatures above 15 degrees and approximately 24,900 for temperatures below 15 degrees C. 15 degrees is, apparently, a critical temperature for this process. 4. The calculated values of micro for eight stages of development preceding hatching, i.e. 6 somites, 12 somites, 18 somites, 24 somites, three-quarters circles, four-fifths circles, five-sixths circles, and full circles, are essentially the same as the micro's for hatching, indicating that the rate of differentiation up to hatching is governed by one process throughout. Critical temperatures for these stages approximate 15 degrees . 5. The total mortality during the incubation period was least at 16 degrees C. where it amounted to 43 per cent. At temperatures above and below this there was a steady increase in the percentage of mortality which reached 100 per cent at 10 degrees and 21 degrees . PMID- 19872744 TI - THE VIOLOGEN INDICATORS. AB - The tabulation gives the normal potentials of the various indicators at 30 degrees C.; referred to the normal hydrogen electrode, the accuracy is estimated to be +/-0.002 volt. Normal potentials of the viologens at 30 degrees C.: Methyl viologen -0.446 volts Ethyl viologen -0.449 volts Betaine viologen -0.444 volts Benzyl viologen -0.359 volts Supposing some solution brings about a coloration of one of these indicators to the extent of A per cent of the maximum color, the oxidation-reduction potential of this solution is E = E(o) - 0.06 log See PDF for Equation where E(o) is the normal potential according to the above tabulation. This normal potential is independent of pH. PMID- 19872745 TI - MOVEMENT IN THE CYANOPHYCEAE : THE EFFECT OF pH UPON MOVEMENT IN OSCILLATORIA. AB - The effect of pH upon the velocity of translatory movement of Oscillatoria formosa Bory in inorganic culture solutions was determined. Unhindered movement occurred in the range of about pH 6.4 to 9.5. Above and below these limits inhibition was marked. In the unfavorable acid and alkaline ranges inhibition was progressive with exposure time; in the favorable range continuous movement was maintained for 24 hours. PMID- 19872746 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. VIII. AB - The upward geotropic orientation (angle theta) of adult rats (race A) has been measured as a function of slope of substratum. The relative variation of orientation angle is a declining rectilinear function of theta. The fraction of the total observable variation of performance (theta) which is controlled by the intensity of excitation (56 per cent) is identical with that found for young rats of the same strain, although the total variation is a little greater. Injection of adrenin distorts the theta vs. alpha graph in a manner quite concordant with the effect obtained in young rats. With the adults the absolute magnitudes of the variations of theta, at corresponding intensities of excitation, are not affected by the action of adrenin, and, as with the young, the proportion of modifiable variation of theta is not altered. The variability of performance, considered as a function of the performance, must therefore be regarded as an organic invariant. Certain consequences of this finding are referred to. PMID- 19872747 TI - STIMULATION BY MINERAL AND FATTY ACIDS IN THE BARNACLE BALANUS BALANOIDES. AB - 1. Stimulation in the rock barnacle Balanus balanoides by hydrochloric, sulfuric, and nitric acids, and by the first seven members of the normal aliphatic acid series has been studied. The hydrogen ion concentrations of the solutions tested varied from 3.2 x 10(-8) to 5.889 x 10(-6). The criterion of response was percentage closure in groups of individuals, recorded at 1 minute intervals until maximum closure occurred. 2. The intensity of stimulation by these acids is proportional to the effects of two forces, one related to the change in the (H(+)), and the other to the field of force around the anion of the acid added to the environment. 3. A preliminary interpretation of the results led to the development of the following expression which fits approximately the data obtained at the end of 4 minutes: Per cent closure = 100 - 100e( 0.1z+(0.003125)2(-0.1z+(0.003125)2n)(z-0.4)) where z is the (H(+)) x 10(7) and n is the number of carbon atoms (if present) in the anion of the acid. This equation assumes that the anions of the mineral acids enter into the reaction stoichiometrically, and emphasizes the difference in the fields of force around the anion of the fatty acids, a difference which is correlated with the length of the carbon chain. 4. A further analysis of the data revealed the presence of three or more receptor groups which appeared to be differentially affected by forces originating from the anions of the acids. 5. The order of stimulating efficiency for the mineral acids was found to be: HCl>H(2)SO(4)>HNO(3). 6. The order of stimulating efficiency for the fatty acids was found to be: heptylic>caproic>valeric>butyric = acetic>propionic = formic. PMID- 19872748 TI - PHOTIC STIMULATION AND LEG MOVEMENTS IN THE CRAYFISH. AB - When Cambarus clarkii is exposed to a source of light so that both eyes are equally illuminated, leg movements of the two sides are equal in frequency and amplitude. On covering one eye and exposing the uncovered eye to light, leg movements on the side of the uncovered eye are more frequent and are of greater amplitude than on the side of the covered eye. On covering the exposed eye also the leg movements on the two sides again tend to become equal in frequency and amplitude. When one eye is lost and the other remains functional, the leg movements on the side of the lost eye will be similar to those on the side of a normal, covered eye. PMID- 19872749 TI - QUANTITATIVE ASPECTS OF CUTANEOUS SENSORY ADAPTATION. I. AB - 1. Adaptation of tactile receptors in the skin of the frog to excitation by an intermittent jet of air is measured and correlated with certain properties of a series of notched discs used to interrupt the air stream. 2. Adaptation in fifteen cases is found to be described by either one of two empirical formulas, or t = -k log f + C, for nine preparations t = a f(-b), for six preparations where f is the per cent frequency at time t and -k and -b are constants defining the rate of adaptation. PMID- 19872750 TI - REACTIONS OF VALONIA AND OF HALICYSTIS TO COLLOIDS. AB - From the results of these tests it is clear that both Halicystis and Valonia have a high degree of tolerance for animal peptone, and a very high degree of tolerance for animal proteose and for egg albumen. The products of bacterial growths fostered by these proteins have a deleterious effect upon both species of algae; but, if it were possible to prevent bacterial growth entirely and at the same time supply proper food, it is probable that Halicystis and Valonia would show normal growth indefinitely in the presence of these three colloids. This is not true where exposure is made to yeast nucleic acid dissolved in sea water containing 0.00093 gm. per cc. of NaOH. Valonia is markedly less tolerant of this medium (perhaps of NaOH rather than the colloid used) than Halicystis. Such differential effects, however, reach a high point in the case of the solutions of diphtheria toxin and of edestin. Halicystis has a very high tolerance for diphtheria toxin, and Valonia a very low tolerance. In the case of edestin, the relationship is reversed. Here Halicystis has a very low tolerance, and Valonia a very high tolerance. In fact, it may be said that diphtheria toxin has no appreciable effect upon Halicystis, and edestin a very slight effect upon Valonia; while diphtheria toxin is extremely toxic to Valonia, and edestin is extremely toxic to Halicystis. We can offer no suggestions, at present, as to the way in which these effects are produced. It is probable that the very thin protoplasmic layer of these species, which is certainly no thicker than 8micro, is sufficient to obstruct the passage of proteins having large molecules, like egg albumen, with a degree of efficiency that is extraordinary. In the tests we have reported, areas of from 20 sq. cm. to 40 sq. cm. have been submitted to the action of a relatively high concentration of egg albumen for several days without permitting the passage of sufficient amounts to give definable tests either with Spiegler's or with Tanret's method,- presumably less than 1 part in 250,000. In the tests of the proteins having much smaller molecules (though the size may not be the explanation), there is some probability that the membranes exhibit a little permeability. The peptone and the proteose of animal origin, or biuret positive substances derived from them, apparently pass the protoplasmic membranes occasionally in quantities sufficient to give biuret tests. The most probable case of protein passage, however, was that of the proteose of the scarlet runner bean, where specific detection of less than 1 part per 80,000 was possible. In this instance the proteose appeared to pass membranes that were healthy and were functioning normally. But since the cells of the algae had to be destroyed in making the tests, one cannot maintain this point. All one can say is that protein passage was indicated in carefully examined cells of both species, where no breaks in the protoplasmic membrane were discernible, and where samples of the treated cells behaved normally after treatment. PMID- 19872751 TI - THE REACTIONS OF HALICYSTIS AND OF VALONIA TO INJECTIONS OF CERTAIN PROTEINS. AB - It is shown (1) that Valonia and Halicystis cells exhibit varying degrees of tolerance to injections of animal peptone, animal proteose, crystallized egg albumen, and diphtheria toxin; (2) that Valonia cells display decreased tolerance to egg albumen in increasing dosages, although Halicystis is completely tolerant of the highest dosage used; (3) that the mortality curves of Valonia injected with egg albumen and of both Valonia and Halicystis injected with diphtheria toxin show the delayed effect characteristic of laboratory mammals when treated similarly; (4) that Valonia cells injected twice with egg albumen exhibit no change in susceptibility to its effects; and (5) that neither species of algae gives evidence of having formed antibodies against the antigens used. PMID- 19872752 TI - THE MODIFICATION OF ANTIBODIES BY FORMALDEHYDE. AB - Certain strains of bacteria which have only minimal zeta potentials over a wide range of pH, and upon which surface deposits can be formed, afford a favorable means of studying certain chemical and physical properties of the surface deposits. Films of specific antibody-globulin upon these bacteria possess basic groups which can combine with formaldehyde. Combination of these groups with HCHO under the conditions of the present experiments shifts the isoelectric point of the sensitizing film toward the acid side by about 0.6 to 0.8 pH unit, and reduces the agglutinating tendency of the sensitizing film. Antibodies may be formalinized before combination with antigen without marked change in their specific combining affinities. The properties of the sensitizing films are similar whether formol treatment occurs before or after the antigen-antibody combination. The nature of the basic groups has been discussed. PMID- 19872754 TI - SWELLING OF ERYTHROCYTES IN SOLUTIONS OF AMMONIUM SALTS. AB - Two rather simple equations have been derived, which make it possible to express in a single number the result of a series of determinations of the volume of erythrocytes swelling in solutions of ammonium salts. In all experiments made with several combinations of different concentrations of permeating and non permeating salts, the curves calculated from the equations have covered the points found by experiment. PMID- 19872753 TI - THE COUPLED REDOX POTENTIAL OF THE LACTATE-ENZYME-PYRUVATE SYSTEM. AB - 1. The term "coupled redox potential" is defined. 2. The system lactic ion See PDF for Equation pyruvic ion + 2H(+) + 2e is shown to be reversible (when the enzyme is lactic acid dehydrogenase) and its coupled redox potential between pH 5.2 and 7.2 at 32 degrees C. is: See PDF for Equation 3. The free energy of the reaction: lactic ion (1m) --> pyruvic ion (1m) = -DeltaF = -14,572. 4. The standard free energy of formation (DeltaF(298)) of pyruvic acid (l) is estimated at -108,127. This is merely an approximation as some necessary data are lacking. 5. The importance of coupled redox potentials as a factor in the regulation of the equilibrium of metabolites is indicated. PMID- 19872755 TI - APPARATUS FOR THE STUDY OF REDOX POTENTIAL IN BIOLOGICAL SYSTEMS. PMID- 19872756 TI - REVERSIBLE LOSS OF THE POTASSIUM EFFECT IN DISTILLED WATER. AB - Not only does distilled water take away the irritability of Nitella but it also changes its behavior toward potassium. In normal cells potassium is strongly negative to sodium but after sufficient exposure to distilled water this effect disappears. It can be restored by returning the cells to their normal environment or to a suitable nutrient solution. This change in the protoplasm seems to be chiefly in its outer surface. PMID- 19872757 TI - PROTOPLASMIC POTENTIALS IN HALICYSTIS : III. THE EFFECTS OF AMMONIA. AB - The nature and origin of the large "protoplasmic" potential in Halicystis must be studied by altering conditions, not only in external solutions, but in the sap and the protoplasm itself. Such interior alteration caused by the penetration of ammonia is described. Concentrations of NH(4)Cl in the sea water were varied from 0.00001 M to above 0.01 M. At pH 8.1 there is little effect below 0.0005 M NH(4)Cl. At about 0.001 M a sudden reversal of the potential difference across the protoplasm occurs, from about 68 mv. outside positive to 30 to 40 mv. outside negative. At this threshold value the time curve is characteristically S-shaped, with a slow beginning, a rapid reversal, and then an irregularly wavering negative value. There are characteristic cusps at the first application of the NH(4)Cl, also immediately after the reversal. The application of higher NH(4)Cl concentrations causes a more rapid reversal, and also a somewhat higher negative value. Conversely the reduction of NH(4)Cl concentrations causes recovery of the normal positive potential, but the threshold for recovery is at a lower concentration than for the original reversal. A temporary overshooting or increase of the positive potential usually occurs on recovery. The reversals may be repeated many times on the same cell without injury. The plot of P.D. against the log of ammonium ion concentration is not the straight line characteristic of ionic concentration effects, but has a break of 100 mv. or more at the threshold value. Further evidence that the potential is not greatly influenced by ammonium ions is obtained by altering the pH of the sea water. At pH 5, no reversal occurs with 0.1 M NH(4)Cl, while at pH 10.3, the NH(4)Cl threshold is 0.0001 M or less. This indicates that the reversal is due to undissociated ammonia. The penetration of NH(3) into the cells increases both the internal ammonia and the pH. The actual concentration of ammonium salt in the sap is again shown to have little effect on the (P.D.) The pH is therefore the governing factor. But assuming that NH(3) enters the cells until it is in equilibrium between sap and sea water, no sudden break of pH should occur, pH being instead directly proportional to log NH(3) for any constant (NH(4)) concentration. Experimentally, a linear relation is found between the pH of the sap and the log NH(3) in sea water. The sudden change of P.D. must therefore be ascribed to some system in the cell upon which the pH change operates. The pH value of the sap at the NH(3) threshold is between 6.0 and 6.5 which corresponds well with the pH value found to cause reversal of P.D. by direct perfusion of solutions in the vacuole. PMID- 19872758 TI - THE INACTIVATION OF BACTERIOPHAGE BY MERCURY BICHLORIDE; THE REACTIVATION OF BICHLORIDE-INACTIVATED PHAGE. AB - 1. The inactivation of antistaphylococcus bacteriophage suspended in infusion broth at pH 7.6 and 22 degrees C. by HgCl(2) proceeds according to the equation dP/dt = k [HgCl(2)] [P(o) - P(i)] over the range studied. 2. This inactivation can be reversed by precipitation of Hg(++) with H(2)S. In the present experiments the inactivation was carried out until only some 5 per cent of the initial phage remained active. After reactivation the [P] had increased to 100 per cent of the initial [P]. PMID- 19872759 TI - THE EFFECT OF WATER CONTENT UPON THE RATE OF HEAT DENATURATION OF CRYSTALLIZABLE EGG ALBUMIN. AB - 1. The denaturation rate of partially dried crystallizable egg albumin is greatly decreased by decreasing its water content. 2. The temperature of denaturation, defined as the temperature at which half of the protein becomes insoluble in distilled water after a definite time of heating, is a linear function of the relative humidity with which the protein is in equilibrium. 3. By applying the Arrhenius equation it is shown that the rate of heat denaturation at a given temperature is an exponential function of the relative humidity. 4. The application of the observed relations to the analysis of the mechanism of thermal death of microorganisms is suggested. 5. The water content of native and heat denatured egg albumin is determined as a function of the relative humidity of water vapor. It is shown that the heat-denatured modification takes up approximately 80 per cent as much water at all relative humidities as does native egg albumin. PMID- 19872760 TI - GELATINASE AND THE GATES-GILMAN-COWGILL METHOD OF PEPSIN ESTIMATION. AB - The Gates photographic film method for pepsin estimation as developed by Gilman and Cowgill measures an activity corresponding to that determined by the hemoglobin method of Anson and Mirsky rather than that resulting from the use of the gelatin viscosity technique. Therefore, the presence of gelatinase is not a source of great error in the gelatin film procedure. PMID- 19872761 TI - THE REFRACTIVE INDICES OF WHOLE CELLS. AB - Refractive indices of intact sporangiophores of Phycomyces were computed from measurements of focal length and radius of curvature of the cells. For the six cells studied, effective values of n were obtained ranging from 1.35 to 1.40. The average effective n was 1.38. Senn's determination of refractive indices of other plants cells gave much higher values: n = 1.37 to 1.52. The precision of the method and possible sources of this discrepancy are discussed. PMID- 19872762 TI - THE PHYSICAL BASIS OF THE POSITIVE PHOTOTROPISM OF PHYCOMYCES. AB - A physical basis is demonstrated, in the case of a cylindrical cell illuminated with parallel light from one side, for greater photochemical action in the half of the cell farthest from the source of light, when the cell is surrounded by a medium of refractive index less than that of the cell. Factors governing the balance and magnitude of unequal action of light in the two halves of the cell are: the refractive index of the cell, the cell radius, and the absorption coefficient of the intracellular pigment. A limiting value of absorption coefficient is deduced which cannot be exceeded in cells of a particular size showing positive phototropism. In terms of this mechanism the positive phototropism of Phycomyces in air is explained. PMID- 19872763 TI - THE ACTION OF THE PLANT GROWTH HORMONE. AB - 1. Sections of Avena coleoptiles are found to show a considerable elongation when suspended in solutions of growth substance. 2. This elongation does not take place in the absence of O(2) and is inhibited by KCN and phenylurethane. 3. The rate of respiration of sections of coleoptiles is increased by the addition of growth substance in concentrations which cause growth. High concentrations of growth substance inhibit growth and also respiration. 4. The increase in respiration is inhibited by KCN and phenylurethane in the concentrations which inhibit normal respiration. These concentrations are the same as those which inhibit growth. 5. From 2, 3, and 4, it seems possible that the increase in respiration caused by growth substance may be an essential part of its action in growth. PMID- 19872764 TI - CRITICAL FREQUENCY OF FLICKER AS A FUNCTION OF INTENSITY OF ILLUMINATION FOR THE EYE OF THE BEE. AB - The bee's characteristic response to a movement of its visual field is used for the study of the relation between critical frequency of flicker and illumination. The critical flicker frequency varies with illumination in such a way that with increasing flicker frequency the intensity of illumination must be increased to produce a threshold response in the bee. The illuminations required to give a response in a bee at different flicker frequencies closely correspond to the intensities for threshold response in visual acuity tests. This is due to the different thresholds of excitability of the elements of the ommatidial mosaic. An analysis of the variation of the values for threshold intensities at the several flicker frequencies shows that the variation depends upon flicker frequency and upon the number of elements functioning at different intensities. PMID- 19872765 TI - ELECTRICAL RESPONSES FROM LATERAL-LINE NERVES OF FISHES. III. AB - Evidence indicates that lateral-line fibers, other than those mediating the "spontaneous" activity of the lateral-line receptors, are brought into play in response to pressure stimuli in catfish and in trout. The distribution and mode of stimulation of mechanoreceptors along the lateral-lines of trout and catfish are discussed in relation to the natural activities of these forms. PMID- 19872766 TI - SOME METHODICAL ERRORS WHICH MAY ARISE IN THE DETERMINATION OF BOUND WATER. AB - The "bound water" hypothesis has an adequate theoretical basis. A relatively slight adsorption of the solute along with water molecules (bound water) will explain the failure of certain technics to demonstrate the existence of bound water in biochemical systems. PMID- 19872767 TI - ANESTHESIA PRODUCED BY DISTILLED WATER. AB - Cells of Nitella flexilis Ag. lose their power to respond to ordinary electrical stimulation after 2 or 3 days in distilled water. It returns after a day or so when they are replaced in their normal environment, in a suitable nutrient solution, or in a dilute solution of CaCl(2). Here anesthesia seems to be produced by removing something from the cell and this raises the question whether other cases of anesthesia may be explained in the same way. The antagonistic action of calcium, in some cases at least, appears to depend on its power to prevent substances from leaching out of the cell. PMID- 19872768 TI - ANESTHESIA IN ACID AND ALKALINE SOLUTIONS. AB - The action of distilled water in producing anesthesia (loss of response to electrical stimulation) in Nitella is hastened by the addition of acid and alkali and retarded by the addition of calcium. The loss of irritability is fully reversible. PMID- 19872769 TI - THE EFFECT OF ULTRAVIOLET LIGHT ON PHOTOSYNTHESIS. AB - 1. An unidentified unit in the mechanism of the photosynthesis of Chlorella pyrenoidosa is rendered inactive by the absorption of one quantum of ultraviolet light (2537 A wave length). 2. The same irradiation has no effect on the normal respiration of Chlorella pyrenoidosa. Experiments have not yet been made on the respiration inhibitable by HCN. 3. No chemical change was detected in the chlorophyll extracted from irradiated cells. PMID- 19872770 TI - THE ORDER OF THE BLACKMAN REACTION IN PHOTOSYNTHESIS. AB - On the assumption that photosynthesis is a cyclic process and that irradiation by ultraviolet light does not change the reaction constants, the Blackman reaction is shown to be of first order. PMID- 19872771 TI - THE ESTIMATION OF TRYPSIN WITH HEMOGLOBIN. AB - The formation from hemoglobin of split products not precipitable by trichloracetic acid is taken as a measure of tryptic activity. The split products are estimated colorimetrically. Many measurements of tryptic activity can be made in a short time and different samples of hemoglobin yield the same results. PMID- 19872772 TI - THE ESTIMATION OF ACTIVE NATIVE TRYPSIN IN THE PRESENCE OF INACTIVE DENATURED TRYPSIN. AB - Inactive denatured trypsin changes into active native trypsin in the protein solutions which have been used to estimate tryptic activity. If the digestion mixture, however, is alkaline enough and contains enough urea this change does not take place. Such a digestion mixture can be used to estimate active native trypsin in the presence of inactive denatured trypsin. PMID- 19872773 TI - ABSORPTION OF PEPSIN BY CRYSTALLINE PROTEINS. AB - Crystalline proteins, such as edestin or melon globulin, remove pepsin from solution. The pepsin protein is taken up as such and the quantity of protein taken up by the foreign protein is just equivalent to the peptic activity found in the complex. The formation of the complex depends on the pH and is at a maximum at pH 4.0. An insoluble complex is formed and precipitates when pepsin and edestin solutions are mixed and the maximum precipitation is also at pH 4.0. The composition of the precipitate varies with the relative quantity of pepsin and edestin. It contains a maximum quantity of pepsin when the ratio of pepsin to edestin is about 2 to 1. This complex may consist of 75 per cent pepsin and have three-quarters of the activity of crystalline pepsin itself. The pepsin may be extracted from the complex by washing with cold N/4 sulfuric acid. If the complex is dissolved in acid solution at about pH 2.0 the foreign protein is rapidly digested and the pepsin protein is left and may be isolated. The pepsin protein may be identified by its tyrosine plus tryptophane content, basic nitrogen content, crystalline form and specific activity. PMID- 19872774 TI - ELECTRICAL RESPONSES FROM THE LATERAL-LINE NERVES OF FISHES : IV. THE REPETITIVE DISCHARGE. AB - The spontaneous discharge of impulses from the lateral-line nerves of trout and catfish has been examined. 1. Broken endings of nerve fibers supplying receptors of the lateral-lines of trout and catfish may be the source of a repetitive discharge of nerve impulses. 2. This injury discharge occurs more frequently in trout and may mask the spontaneous discharge from the receptor cells. Experiments indicate that the latter discharge is not the result of injury. 3. The injury discharge ceases in from 10 to 15 minutes. The spontaneous receptor discharge in trout may continue for an hour if the circulation remains intact. The receptor response also fails in from 10 to 15 minutes after failure of the circulation. 4. The receptor discharge, the injury discharge, or the summed discharges frequently become synchronized. The excitability of the fibers of the nerve trunk appears to vary synchronously, so that nerve impulses initiated in fibers from tactile receptors not contributing to the spontaneous discharge can be conducted only during the part of the cycle occupied by the spontaneous discharge. PMID- 19872775 TI - THE THEORY OF DIFFUSION IN CELL MODELS. AB - The differential equations which describe the simultaneous diffusion of water and a salt in a cell model have been formulated and solved. The equations have been derived from the general laws which describe diffusion processes, thereby furnishing a physical interpretation for the constants which enter into the theory. The theoretical time curves for the two diffusing substances are in good agreement with the experimentally determined curves and accurately reproduce all of the essential characteristics of the experiment. PMID- 19872776 TI - INTERMITTENT STIMULATION BY LIGHT : II. THE MEASUREMENT OF CRITICAL FUSION FREQUENCY FOR THE HUMAN EYE. AB - An apparatus and a procedure are described to measure the critical frequency of flicker using different portions of the eye. The observer, looking through a pupil of fixed dimensions, views a field of 2 degrees whose illumination is periodically interrupted and which is surrounded by a field of 10 degrees whose illumination is continuous but otherwise identical with the interrupted field. Various parts of the apparatus are concerned with controlling and recording the retinal position of the field, its intensity, its spectral composition, and the frequency of interruption of its illumination. The procedure is so simplified and regulated that a complete set of readings over the whole intensity range of vision can be made at one sitting without fatigue or strain. PMID- 19872777 TI - INTERMITTENT STIMULATION BY LIGHT : III. THE RELATION BETWEEN INTENSITY AND CRITICAL FUSION FREQUENCY FOR DIFFERENT RETINAL LOCATIONS. AB - When measurements of the critical fusion frequency for white light over a large range of intensities are made with the rod-free area of the fovea, the relation between critical frequency and log I is given by a single sigmoid curve, the middle portion of which approximates a straight line whose slope is 11.0. This single relation must be a function of the foveal cones. When the measurements are made with a retinal area placed 5 degrees from the fovea, and therefore containing both rods and cones, the relation between critical frequency and log I shows two clearly separated sections. At the lower intensities the relation is sigmoid and reaches an upper level at about 10 cycles per second, which is maintained for 1.25 log units, and is followed by another sigmoid relationship at the higher intensities similar to the one given by the rod-free area alone. These two parts of the data are obviously separate functions of the rods at low intensities and of the cones at high intensities. This is further borne out by similar measurements made with retinal areas 15 degrees and 20 degrees from the fovea where the ratio of rods to cones is anatomically greater than at 5 degrees . The two sections of the data come out farther apart on the intensity scale, the rod portion being at lower intensities and the cone portion at higher intensities than at 5 degrees . The general form of the relation between critical frequency and intensity is therefore determined by the relative predominance of the cones and the rods in the retinal area used for the measurements. PMID- 19872778 TI - INTERMITTENT STIMULATION BY LIGHT : IV. A THEORETICAL INTERPRETATION OF THE QUANTITATIVE DATA OF FLICKER. AB - A theoretical treatment of the data of intermittent stimulation by light is presented in terms of the familiar reversible photochemical system previously used for other properties of vision. It appears that such a system considered merely as the initial event in photoreception is capable of giving a first order quantitative description of the relation between critical frequency and illumination for different retinal regions, and of Talbot's law. Moreover the development of this concept shows that the general form of most of the existing relationships in flicker are already apparent in the characteristics of the behavior of this initial photochemical event. PMID- 19872779 TI - THE CONVERSION OF FAT TO CARBOHYDRATE IN THE GERMINATING CASTOR BEAN : I. THE RESPIRATORY METABOLISM. AB - 1. Respiration studies on single castor beans, made by means of the Brodie Warburg method, at various times after the start of germination, as well as studies on groups of germinating beans over periods of 3 to 8 days, made by a simple procedure involving analysis of the respired air by the Haldane method, consistently give respiratory quotients from 0.30 to 0.58, indicating the conversion of the oil to carbohydrate. 2. The R.Q. varies with the stage of germination, the lowest point occurring when the new growth (hypocotyl) measures from 20 to 35 mm. in length. 3. The R.Q. of the young plant (cotyledons and hypocotyl), separated from the endosperm and studied in the same apparatus, varies from 0.78 to 1.00. It is invariably high enough to indicate considerable combustion of sugar. The R.Q. of the endosperm alone is low, but usually somewhat higher than that of the entire germinating structure. 4. On the same unit of moist weight the young plant (cotyledons and hypocotyl) produces about 2.6 times as much CO(2) as the endosperm, whereas it absorbs only 1.3 times as much O(2). PMID- 19872780 TI - THE CONVERSION OF FAT TO CARBOHYDRATE IN THE GERMINATING CASTOR BEAN : II. THE COMBUSTION RESPIRATORY QUOTIENT AS DETERMINED BY A MODIFIED OXYCALORIMETER. AB - The combustion respiratory quotients of castor beans germinated to various stages, depending upon the length of the hypocotyl, were determined by means of a modified oxycalorimeter. After germination was well started, the respiratory quotient of the combusted germinated seed increased as the stage of germination increased, indicating a change from an oxygen-poor to an oxygen-rich substance, probably fat to sugar. The accuracy of the method was checked by organic combustions. The seat of formation of the oxygen-rich substance is in the endosperm. PMID- 19872781 TI - THE CONVERSION OF FAT TO CARBOHYDRATE IN THE GERMINATING CASTOR BEAN : III. THE CHEMICAL ANALYSIS, AND CORRELATION WITH RESPIRATORY EXCHANGE. AB - 1. Analyses for fat (ether extract), protein (N x 6.25), sugar including glucose, crude fiber, and ash have been made on all stages of the germinating castor bean up to 250 mm. length of hypocotyl and root system. 2. There is a continual decrease in the amount of fat present in the whole germinating seedling, and a continual increase in the amount of sugar up to about 40 per cent (dry weight) at a hypocotyl length of 80 to 140 mm., after which it decreases as crude fiber (cellulose) increases. The most rapid decrease in fat content coincides roughly with the most rapid increase of sugar. 3. The carbon balance between fat loss and carbohydrate (including fiber) gain is not at all close, except at the very beginning of growth. An undetermined residue occurs, which increases steadily along with the total carbohydrate and accounts for more and more of the carbon. 4. The protein content which in the ungerminated bean is about 26 per cent, at first falls a little and then rather steadily increases to reach nearly 35 per cent (dry) at the last stages studied. The most plausible explanation of this is the occurrence of more and more volatile substance which is lost in drying. 5. The ash increases irregularly but in the end shows about the same ratio of increase as the protein. 6. Respiration studies on several lots of these beans at different stages of germination exhibited the same low respiratory quotients as reported in Paper I. Comparing their composition at the end of the respiration period with that of corresponding stages when the period began, the chemical change can be compared with the respiratory exchange. 7. A trial balance of all the carbon changes including the respiratory carbon and protein carbon is not very satisfactory, because of our ignorance of the undetermined residue. 8. The respiratory quotient found can be accounted for quite satisfactorily on the assumption that two out of six molecules of ricinoleic acid are converted to cane sugar, one to cellulose, and three are oxidized. 9. The oxygen needed to produce the quantities of known carbohydrate found, added to that used for combustion, and the total subtracted from the observed loss from the respired air yields in two experiments a quantity which, combined with the excess carbon, suggests that the undetermined substance may be an oxidation product of pentose. PMID- 19872782 TI - THE CRYOSCOPIC METHOD FOR THE DETERMINATION OF "BOUND WATER". AB - 1. The criticisms by Grollman (7) of the cryoscopic method for the determination of bound water as proposed by Newton and Gortner (1) have been considered, and it is pointed out that even admitting the correctness of his contentions does not negative the conclusion that bound water values as determined by the cryoscopic method parallel in a remarkable manner the physiological responses of plants to environmental conditions. 2. A new method of calculating the true freezing point of a solution is proposed. 3. Gum acacia in aqueous sucrose solutions shows positive amounts of bound water to the extent of 0.6 to 0.7 gm. of bound water per gram of gum. 4. Gum acacia in aqueous solutions of KCl and KBr shows slightly negative amounts of bound water, indicating a preferential adsorption of the solute rather than the solvent. PMID- 19872783 TI - THE INFLUENCE OF THE MOLECULAR WEIGHT ANTIGEN ON THE PROPORTION OF ANTIBODY TO ANTIGEN IN PRECIPITATES. AB - The assumption that, at the equivalence point in specific precipitin reactions, the antigen molecule is completely covered with a single layer of antibody globulin molecules has been shown to account fairly well for the antibody-antigen ratios of some representative native single proteins, and the pneumococcus S III hapten. PMID- 19872784 TI - BACTERIAL CELL METABOLISM UNDER ANAEROBIC CONDITIONS. AB - Escherichia coli has been cultivated in a peptone water medium saturated continuously with nitrogen by use of a gas train so as to produce anaerobic conditions. Under these circumstances growth was greatly inhibited. Cultures which originally contained 11 million bacteria per cc. showed on the average only 32 million after 5 hours (as compared with 655 million in similar cultures saturated with air). The metabolic activity of the cells in such a culture was greatly reduced by the anaerobic conditions. It actually fell off from 42 mg. x 10(-11) per cell per hour during the 1st hour to 27 mg. during the 2nd hour and rose only to a maximum of 68 during the 3rd hour. Similar cultures saturated with air showed a rise from 37 mg. x 10(-11) during the 1st hour to 123 during the 2nd hour. The addition of glucose to the medium, under aerobic conditions, has been shown in previous studies to cause only a slight increase in bacterial numbers (861 instead of 655 million after the 5th hour). In the cultures aerated with nitrogen, the addition of glucose has no effect during the first hours. There is again a long lag period and a reduced metabolic rate. After the 2nd hour, however, a wholly different phenomenon manifests itself. The bacterial population increases more rapidly than in the anaerobic peptone medium (reaching a maximum of 142 million after 5 hours). This growth is accompanied by an enormous increase in the rate of CO(2) yield, which reaches 211 mg. x 10(-11) per cell per hour during the 4th hour (nearly double the maximum values recorded under aerobic conditions). The same phenomenon is, of course, illustrated by the enormous yield of CO(2) produced by the action of fermenting organisms in carbohydrate media recorded by Anderson (1924) and other students of the obligate anaerobes. We have here, however, a somewhat striking illustration of the distinct type of metabolic activity manifested by a facultative organism under anaerobic conditions in the presence of sugar measured on a cell-per-hour basis. This is a quantitative illustration of the "life without air" described by Pasteur. PMID- 19872785 TI - CRYSTALLINE PEPSIN : VI. INACTIVATION BY BETA AND GAMMA RAYS FROM RADIUM AND BY ULTRA-VIOLET LIGHT. AB - 1. The loss in activity of crystalline pepsin solutions when exposed to beta and gamma rays from radium or to ultra-violet light is accompanied by a corresponding decrease in pepsin protein. 2. The rate of inactivation by ultra-violet light depends upon the pH and is a maximum at about pH 2.0. PMID- 19872786 TI - MOLECULAR WEIGHT, MOLECULAR VOLUME, AND HYDRATION OF PROTEINS IN SOLUTION. AB - 1. The gram molecular weight of a substance may be calculated from the osmotic pressure of its solution. 2. The radius of the hydrated molecule and, hence, the gram molecular volume of the hydrated solute may be determined from diffusion measurements. The hydration of the molecules may, therefore, be calculated from osmotic pressure and diffusion measurements. 3. Hydration may also be determined by viscosity measurements. Hydration of crystalline hemoglobin, crystalline trypsin, and gelatin have been determined by these methods and found to be as follows: See PDF for Structure. PMID- 19872787 TI - A NOTE ON THE RESPIRATION OF ARBACIA EGGS. AB - Methods used in preparing Arbacia eggs for respiration studies, in carrying through the manometric determinations, and in estimating egg quantities have been reexamined. Discrepancies in previous results are almost entirely due to a steady error in measuring egg volume by centrifuging. Volumes so obtained averaged 80 per cent too high. The respiration of unfertilized eggs of Arbacia punctulata at 21 degrees C. is 0.9 c.mm. O(2) per hour per 10 c.mm. of eggs. PMID- 19872788 TI - A PHOTOELECTRIC DENSITOMETER FOR USE WITH SUSPENSIONS. AB - A device for quickly and accurately measuring the population density of a suspension of microorganisms, permitting the preparation of yeast suspensions of known density to within 1 per cent error, was constructed with two Visitron photoelectric cells, a single light of high intensity and a good Wheatstone bridge for balancing the currents from the two photoelectric cells. A large Pyrex milk culture tube holding the suspension is placed in the path of one beam of light coming through a small longitudinal slit and thence to one photocell; a second similar slit directs another beam of light upon the second photocell, thus causing dissimilar currents to flow, the ratio of whose magnitudes may be measured by the bridge resistances. A relation between these currents and the relative light intensities is shown, and the one significant unmeasurable variable (the characteristic constant of a photocell) is practically eliminated by the use of a method of ratios. After careful standardization of technique the apparatus proved more accurate than other methods available for the purpose indicated. In rapid use its accuracy may be put safely at 1 per cent for measuring the densities of cultures of approximately the same age and composed of cells having comparable optical characteristics. PMID- 19872789 TI - THE EQUILIBRIUM BETWEEN ACTIVE NATIVE TRYPSIN AND INACTIVE DENATURED TRYPSIN. AB - There is a mobile equilibrium between the native and denatured forms of trypsin which depends on the concentrations of acid, alkali, and alcohol and on the temperature. The heat of denaturation in 0.01 N hydrochloric acid calculated from the effect of temperature on the equilibrium constant is -67,600 calories per mole. PMID- 19872790 TI - THE EQUILIBRIA BETWEEN NATIVE AND DENATURED HEMOGLOBIN IN SALICYLATE SOLUTIONS AND THE THEORETICAL CONSEQUENCES OF THE EQUILIBRIUM BETWEEN NATIVE AND DENATURED PROTEIN. AB - The denaturation of hemoglobin by salicylate in neutral solution is completely reversible. There is a mobile equilibrium between native and denatured hemoglobin in neutral salicylate solution. The higher the salicylate concentration the greater is the percentage denaturation. When there is a mobile equilibrium between the native and denatured forms of a protein, denaturation is caused by the addition of any substance which has a greater affinity for the denatured than for the native form. Theoretically the heat of denaturation must vary with the denaturing agent and must depend on the heat of combination of the denaturing agent with the protein. PMID- 19872791 TI - ON THE RELATION BETWEEN TOXICITY, RESISTANCE, AND TIME OF SURVIVAL, AND ON RELATED PHENOMENA. AB - 1. A relation between toxicity, resistance, and time of survival has been derived on the basis of the assumption that the time is a function of a parameter which is the difference between the toxicity and the resistance. Toxicity and resistance act like forces which can maintain an equilibrium-like (or stationary) state. If the equilibrium is upset, the time at which the event (death) occurs is proportional to the logarithm of the difference between toxicity and resistance. 2. It was found that if values proportional to the resistance are calculated with the proposed equation and the percentage mortality plotted against them (instead of against the time as is usual) symmetrical curves are obtained even though the corresponding mortality-time curves are asymmetrical. Assuming that the resistance varies like an error, that is, according to probability rules, theoretical mortality-time curves, similar to the experimental curves, can be constructed from the proposed equations. 3. In the case of a toxic agent acting on a unicellular organism suspended in solution, the toxicity is proportional to the adsorbed amount of the agent, as calculated with the aid of the Langmuir equation. In small concentration ranges the toxicity can be taken as approximately proportional to the concentration. 4. The variation of the temperature affects mainly the constant a which is a function of the temperature similar to that of the velocity constant of a chemical reaction (Arrhenius' law). 5. The proposed equation has been tested in four different combinations of the variables, concentration, resistance, time, and temperature. The agreement with the experiments is satisfactory. 6. Any noxious agent acting on a unicellular organism may be characterized by three constants: r, the resistance, which is the threshold value at which the agent is still fatally toxic for the organism; a, the reciprocal of the rate constant determining the specific rate (that is, the time corresponding to a difference of 1 between the toxicity and the resistance); and finally the constant gamma of the function representing the relation between toxicity and concentration. PMID- 19872792 TI - THE KINETICS OF PENETRATION : VI. SOME FACTORS AFFECTING PENETRATION. AB - Some of the factors affecting penetration in living cells may be advantageously studied in models in which the organic salts KG and NaG diffuse from an aqueous solution A, through a non-aqueous layer B (representing the protoplasmic surface) into an aqueous solution C (representing the sap and hence called artificial sap) where they react with CO(2) to form KHCO(3) and NaHCO(3). Their relative proportions in C depend chiefly on the partition coefficients and on the diffusion constants in the non-aqueous layer. But the ratio is also affected by other variables, among which are the following: 1. Temperature, affecting diffusion constants and partition coefficients and altering the thickness of the unstirred layers by changing viscosity. 2. Viscosity (especially in the non aqueous layers) which depends on temperature and the presence of solutes. 3. Rate of stirring, which affects the thickness of the unstirred layers and the transport of electrolyte in those that are stirred. 4. Shape and surface area of the non-aqueous layer. 5. Surface forces. 6. Reactions occurring at the outer surface such as loss of water by the electrolyte or its molecular association in the non-aqueous phase. The reverse processes will occur at the inner surface and here also combinations with acids or other substances in the "artificial sap" may occur. 7. Outward diffusion from the artificial sap. The outward movement of KHCO(3) and NaHCO(3) is small compared with the inward movement of KG and NaG when the concentrations are equal. This is because the partition coefficients(3) of the bicarbonates are very low as compared with those of NaG and KG. Since CO(2) and HCO(3) (-) diffuse into A and combine with KG and NaG the inward movement of potassium and sodium falls off in proportion as the concentration of KG and NaG is lessened. 8. Movement of water into the non-aqueous phase and into the artificial sap. This may have a higher temperature coefficient than the penetration of electrolytes. 9. Variation of the partition coefficients with concentration and pH. Many of these variables may occur in living cells. (It happens that the range of variation in the ratio of potassium to sodium in the models resembles that found in Valonia.). PMID- 19872793 TI - KINETICS OF PENETRATION : VII. MOLECULAR VERSUS IONIC TRANSPORT. AB - In some living cells the order of penetration of certain cations corresponds to that of their mobilities in water. This has led to the idea that electrolytes pass chiefly as ions through the protoplasmic surface in which the order of ionic mobilities is supposed to correspond to that found in water. If this correspondence could be demonstrated it would not prove that electrolytes pass chiefly as ions through the protoplasmic surface for such a correspondence could exist if the movement were mostly in molecular form. This is clearly shown in the models here described. In these the protoplasmic surface is represented by a non aqueous layer interposed between two aqueous phases, one representing the external solution, the other the cell sap. The order of penetration through the non-aqueous layer is Cs > Rb > K > Na > Li. This will be recognized as the order of ionic mobilities in water. Nevertheless the movement is mostly in molecular form in the nonaqueous layer (which is used in the model to represent the protoplasmic surface) since the salts are very weak electrolytes in this layer. The chief reason for this order of penetration lies in the fact that the partition coefficients exhibit the same order, that of cesium being greatest and that of lithium smallest. The partition coefficients largely control the rate of entrance since they determine the concentration gradient in the non-aqueous layer which in turn controls the process of penetration. The relative molecular mobilities (diffusion constants) in the non-aqueous layer do not differ greatly. The ionic mobilities are not known (except for K(+) and Na(+)) but they are of negligible importance, since the movement in the non-aqueous layer is largely in molecular form. They may follow the same order as in water, in accordance with Walden's rule. Ammonium appears to enter faster than its partition coefficient would lead us to expect, which may be due to rapid penetration of NH(3). This recalls the apparent rapid penetration of ammonium in living cells which has also been explained as due to the rapid penetration of NH(3). Both observation and calculation indicate that the rate of penetration is not directly proportional to the partition coefficient but increases somewhat less rapidly. Many of these considerations doubtless apply to living cells. PMID- 19872794 TI - BLAIR'S "CONDENSER THEORY" OF NERVE EXCITATION. AB - Blair's recent theory of excitation is analysed with the following conclusions: 1. The theory is inapplicable to currents of long duration; i.e., slowly increasing currents and the opening excitation. 2. The theory is a modification of the condenser theory of excitation but the modification is to be rejected on three grounds: (a) The modification has no obvious physical significance. (b) It does not in fact remedy the divergence between calculation and observation. (c) It leads to certain conclusions of a surprising kind which are contrary to observed fact. 3. The qualitative value of the condenser theory is demonstrated by the fairly close agreement between calculation and observation over a considerable field of enquiry. PMID- 19872795 TI - THE TIME CURVE OF FACET DETERMINATION IN AN ULTRABAR STOCK OF DROSOPHILA MELANOGASTER. AB - By a dissection of the data obtained by Driver on the effective periods at different temperatures in males and females of an ultrabar stock of Drosophila melanogaster it has been found that a symmetrical sigmoid curve satisfactorily describes the time course of the facet-determining reaction. Consequently the differences between members of the bar series in regard to this reaction do not represent merely developmental arrests of the process at some greater or lesser distance from a common upper asymptote, but the termination of the process is approached asymptotically. The velocity constant/temperature relation shows a discontinuity in the neighborhood of 21 degrees which may be causally related to the change in the position of the effective period from the second to the third instar. The velocity constant apparently does not conform to the well known Arrhenius equation in its relation to temperature. PMID- 19872796 TI - THE REVERSIBLE INACTIVATION OF BACTERIOPHAGE BY BICHLORIDE OF MERCURY. AB - 1. The complete inactivation of antistaphylococcal phage by HgCl(2) (2.8 per cent for 216 hours) can be reversed by precipitation of Hg(++) with restoration of the phage to its original titre. 2. This behavior seems more compatible with the known properties of certain enzymes than with those of living protoplasm. PMID- 19872797 TI - THE KINETICS OF PENETRATION : VIII. TEMPORARY ACCUMULATION. AB - A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external solution it will tend to enter and displace the weaker acid HA (if this be carbonic it can readily escape): hence potassium may accumulate to a greater or less extent as KCl. Injury of the cell may produce a twofold effect, (1) increase of permeability, (2) lessened accumulation. The total amount of electrolyte taken up in a given time will be influenced by these factors and may be greater than normal in the injured cell or less, depending somewhat on the length of the interval of time chosen. PMID- 19872798 TI - THE VISUAL ACUITY AND INTENSITY DISCRIMINATION OF DROSOPHILA. AB - Drosophila possesses an inherited reflex response to a moving visual pattern which can be used to measure its capacity for intensity discrimination and its visual acuity at different illuminations. It is found that these two properties of vision run approximately parallel courses as functions of the prevailing intensity. Visual acuity varies with the logarithm of the intensity in much the same sigmoid way as in man, the bee, and the fiddler crab. The resolving power is very poor at low illuminations and increases at high illuminations. The maximum visual acuity is 0.0018, which is 1/1000 of the maximum of the human eye and 1/10 that of the bee. The intensity discrimination of Drosophila is also extremely poor, even at its best. At low illuminations for two intensities to be recognized as different, the higher must be nearly 100 times the lower. This ratio decreases as the intensity increases, and reaches a minimum of 2.5 which is maintained at the highest intensities. The minimum value of DeltaI/I for Drosophila is 1.5, which is to be compared with 0.25 for the bee and 0.006 for man. An explanation of the variation of visual acuity with illumination is given in terms of the variation in number of elements functional in the retinal mosaic at different intensities, this being dependent on the general statistical distribution of thresholds in the ommatidial population. Visual acuity is thus determined by the integral form of this distribution and corresponds to the total number of elements functional. The idea that intensity discrimination is determined by the differential form of this distribution-that is, that it depends on the rate of entrance of functional elements with intensity-is shown to be untenable in the light of the correspondence of the two visual functions. It is suggested that, like visual acuity, intensity discrimination may also have to be considered as a function of the total number of elements active at a given intensity. PMID- 19872799 TI - ON GUAIACOL SOLUTIONS : I. THE ELECTRICAL CONDUCTIVITY OF SODIUM AND POTASSIUM GUAIACOLATES IN GUAIACOL. AB - 1. Measurements on the densities, viscosities, dielectric constants, and specific conductances of pure anhydrous and water-saturated guaiacol at 25 degrees C. are reported. 2. The solubility of water in guaiacol at 25 degrees C., and its effect on the electrical conductivity of a sodium guaiacolate solution is given. 3. Electrical conductivity measurements are reported on solutions of sodium and potassium guaiacolates in water-saturated guaiacol at 25 degrees C. 4. The decrease of electrical conductivity with increasing concentration for these salts is explained on the basis of an ionic equilibrium combined with the interionic attraction theory of Debye and Huckel. 5. The limiting equivalent conductances of sodium and potassium guaiacolates in water-saturated guaiacol at 25 degrees C., the corresponding limiting ionic mobilities, and the dissociation constants are computed from the conductivity measurements. The salts are found to be weak electrolytes with dissociation constants of the order of 5 x 10(-6). PMID- 19872800 TI - ON GUAIACOL SOLUTIONS : II. THE DISTRIBUTION OF SODIUM AND POTASSIUM GUAIACOLATES BETWEEN GUAIACOL AND WATER. AB - 1. Measurements are reported on the distribution of sodium and potassium guaiacolates between guaiacol and water at 25 degrees C. 2. The variation of the partition coefficients with the concentration is explained with the aid of the Debye-Huckel interionic attraction theory and the assumption that the salts are strong electrolytes in water and weak electrolytes in guaiacol. 3. The dissociation constants of sodium and potassium guaiacolates in guaiacol previously computed from electrical conductivity determinations are shown to be in agreement with the corresponding values obtained from the distribution measurements. 4. From theoretical considerations an equation is derived with which it is possible to predict the magnitude of the limiting partition coefficients from the dielectric constants of the solvents, the size of the solute ions, and the temperature. PMID- 19872801 TI - INFLUENCE OF DEATH CRITERIA ON THE X-RAY SURVIVAL CURVES OF THE FUNGUS, NEUROSPORA. AB - 1. When ascospores of Neurospora tetrasperma were irradiated with 11 kv. X-rays, the single spore cultures obtained displayed a wide variety of mutated forms. 2. Control germinations of ascospores showed uniform behavior, ranging from 92-95 per cent germination. 3. The shape of the survival curves was found to be a function of the criterion of death. The following criteria were used: germination, growth, production of mature ascospores, and the production of normal perithecia. 4. The germination survival curve exhibited a rhythmic variation with dosage. Germination is not a significant criterion of death. 5. Half-survival dosages for growth and ascospore production were approximately 30,000 and 20,000 roentgens, respectively. 6. Multiple hit-to-kill relations were found on the basis of the quantum hit theory; no accurate analysis was possible. 7. The studies indicate that ascospore death does not result from a single well defined reaction, but rather from the integrated effects of several deleterious processes initiated by the radiation. PMID- 19872802 TI - INACTIVATION OF CRYSTALLINE TRYPSIN. AB - 1. The rate of inactivation of crystalline trypsin solutions and the nature of the products formed during the inactivation at various pH at temperatures below 37 degrees C. have been studied. 2. The inactivation may be reversible or irreversible. Reversible inactivation is accompanied by the formation of reversibly denatured protein. This denatured protein exists in equilibrium with the native active protein and the equilibrium is shifted towards the denatured form by raising the temperature or by increasing the alkalinity. The decrease in the fraction of active enzyme present (due to the formation of this reversibly denatured protein) as the pH is increased from 8.0 to 12.0 accounts for the decrease in the rate of digestion of proteins by trypsin in this range of pH. 3. The loss of activity at high temperatures or in alkaline solutions, just described, is very rapid and is completely reversible for a short time only. If the solutions are allowed to stand the loss in activity becomes gradually irreversible and is accompanied by the appearance of various reaction products the nature of which depends upon the temperature and pH of the solution. 4. On the acid side of pH 2.0 the trypsin protein is changed to an inactive form which is irreversibly denatured by heat. The course of the reaction in this range is monomolecular and its velocity increases as the acidity increases. 5. From pH 2.0 to 9.0 trypsin protein is slowly hydrolyzed. The course of the inactivation in this range of pH is bimolecular and its velocity increases as the alkalinity increases to pH 10.0 and then decreases. As a result of these two reactions there is a point of maximum stability at about pH 2.3. 6. On the alkaline side of pH 13.0 the reaction is similar to that in strong acid solution and consists in the formation of inactive protein. The course of the reaction is monomolecular and the velocity increases with increasing alkalinity. From pH 9.0 to 12.0 some hydrolysis takes place and some inactive protein is formed and the course of the reaction is represented by the sum of a bi- and monomolecular reaction. The rate of hydrolysis decreases as the solution becomes more alkaline than pH 10.0 while the rate of formation of inactive protein increases so that there is a second point at about pH 13.0 at which the rate of inactivation is a minimum. In general the decrease in activity under all these conditions is proportional to the decrease in the concentration of the trypsin protein. Equations have been derived which agree quantitatively with the various inactivation experiments. PMID- 19872803 TI - ON NORRIS' THEORY FOR THE SHAPE OF THE MAMMALIAN ERYTHROCYTE. AB - This paper is concerned with an attempt to put Norris' theory for the shape of the mammalian erythrocyte into a quantitative form. The theory supposes that the biconcave form of the cell is brought about by an expansive force enlarging the surface, and is also supposed to apply to the formation of the myelin forms of lecithn. The attempt is not successful, and is published merely because it is suggestive. Various points regarding the shape of the cell, the curvature of its surface, and the kind of system to which Norris' theory might be supposed to apply, are discussed, and an empirical formula is given for the curve which bounds the cross-section of the cell. This empirical formula describes the shape almost to perfection. PMID- 19872804 TI - THE POTASSIUM EQUILIBRIUM IN MUSCLE. AB - 1. Analyses were made of the K and HCO(3) content, the irritability, and weight change of isolated frog sartorius muscles after immersion for 5 hours in Ringer's solutions modified as to pH and potassium content. 2. At each pH a concentration of potassium in the solution was found which was in diffusion equilibrium with the potassium in the muscle. In greater concentrations potassium moved into the muscle against the concentration gradient and vice versa. 3. The greater the alkalinity of the solution the smaller the concentration of the potassium at equilibrium so that the product of the concentrations of OH and K in the solution at equilibrium tends to remain approximately constant. 4. The pH inside the muscle is approximately equal to that outside when first dissected but it tends to change during immersion so as to follow the changes in the pH of the solution. This finding is in direct conflict with the theory according to which the high potassium concentration inside should be accompanied by an equally high hydrogen ion concentration in relation to that outside. 5. The diffusion of potassium into the muscle makes its contents more alkaline but the increase in alkalinity is not always, nor usually, equivalent to the amount of potassium which has diffused and conversely, the pH inside can change in either direction according to the pH outside without there being any diffusion of potassium. Hence potassium is not the only penetrating ion. 6. The irritability of the muscles is at a maximum in concentrations of potassium which are greater than that in normal Ringer's solution, or about 20 mg. per cent potassium. This optimum does not seem to be a function of pH and is therefore not dependent upon the direction of movement of the potassium but probably on the ratio of potassium outside to that inside. 7. Swelling of the muscles occurs in solutions which injure the muscle so as to permit both cations and anions to enter without permitting the organic protein anions to escape. Anion impermeability is necessary to prevent this same osmotic swelling under normal conditions. 8. An increase in the CO(2) tension in muscle and solution causes a greater increase in acidity in the solution than in the muscle and leads to a loss of potassium. One expects therefore a potassium shift from tissues to blood comparable to the chlorine shift from plasma to corpuscles. PMID- 19872805 TI - THE DIFFUSION OF CARBON DIOXIDE IN TISSUES. AB - 1. Two methods are given for measuring the rate of diffusion of CO(2) in tissue membranes. Methods are also given for the determination of tissue thickness and the absorption coefficient for CO(2) in tissues. 2. The values obtained for the permeability constant (P x 10(4)) at 22 degrees C. for CO(2) in the following tissues are:-frog skin, 3.05; connective tissue (dog), 2.65; smooth muscle (cat), 5.00; frog muscle, 5.29; striated muscle (dog), 4.70. P is expressed as cc. per cm.(2) per minute under a pressure gradient of one atmosphere per cm. 3. Evidence is presented to show that in a "steady state" bicarbonate contributes a negligible amount to the diffusion of CO(2). 4. The absorption coefficient for CO(2) in frog skin is 0.73 cc. per cc. and for frog muscle 0.78 cc. per cc. 5. In all of the tissues studied the diffusion of CO(2) is slower than in water. The diffusion coefficients (K x 10(4) in cm.(2)/minute) at 22 degrees C. for tissues as compared with water are:-water (16 degrees C.), 9.5 (Hufner, 1897); frog skin, 4.1; connective tissue, 3.7; frog muscle, 6.8; striated muscle (dog), 6.0; smooth muscle (cat), 6.4. 6. The time course of saturation of a tissue with CO(2) is altered in the presence of available base. Non-acidified tissues saturate more slowly than acidified tissues and the rate of saturation is dependent on the CO(2) tension. PMID- 19872806 TI - FERTILIZATION AND THE TEMPERATURE COEFFICIENTS OF OXYGEN CONSUMPTION IN EGGS OF ARBACIA PUNCTULATA. AB - The eggs of A. punctulata have a high temperature coefficient in the resting state: Q(10) = 4.1. On fertilization and on cytolysis the temperature coefficient falls to less than half the resting value: Q(10) = 1.8 and 1.9 respectively. The factor by which oxygen consumption increases on fertilization is a variable, its magnitude depending on temperature as well as on egg species. It is nearly ten times greater at 11 degrees C. and only double at 29.9 degrees C. By extrapolating to 32 degrees C. there would be no increase on fertilization. Critical thermal increments common to many oxidations, 6,500, 10,800, and 12,500, have been found. The possible significance of these results is discussed in relation to the catalytic mechanisms and structural organization of the egg cell. PMID- 19872807 TI - THE GROWTH OF CUCUMIS MELO SEEDLINGS AT DIFFERENT TEMPERATURES. PMID- 19872808 TI - THE INFLUENCE OF ENVIRONMENTAL TEMPERATURE ON THE UTILIZATION OF FOOD ENERGY IN BABY CHICKS. AB - 1. An optimum of environmental temperature is to be expected for the utilization of food energy in warm blooded animals if their food intake is determined by their appetite. 2. Baby chicks were kept in groups of five chicks in a climatic cabinet at environmental temperatures of 21 degrees , 27 degrees , 32 degrees , 38 degrees , and 40 degrees C. during the period of 6 to 15 days of age. The intake of qualitatively complete food was determined by their appetite. Food intake, excretion, and respiratory exchange were measured. Control chicks from the same hatch as the experimental groups were raised in a brooder and were given the same food as the experimental chicks. The basal metabolism of each experimental group was determined from 24 to 36 hours without food at the age of 16 days. 3. The daily rate of growth increased with decreasing environmental temperature from 2.74 gm. at 40 degrees C. to 4.88 gm. at 21 degrees C. This was 4.2 to 6.5 per cent of their body weight. 4. The amount of food consumed increased in proportion to the decrease in temperature. 5. The availability of the food, used for birds instead of the digestibility and defined as See PDF for Structure showed an optimum at 38 degrees C. 6. The CO(2) production increased from 2.95 liters CO(2) per day per chick at 40 degrees C. to 6.25 liters at 21 degrees C. Per unit of the 3/4 power of the body weight, 23.0 liters CO(2) per kilo(3/4) was produced at 40 degrees C. and 43.4 liters per kilo(3/4) at 21 degrees C. The CO(2) production per unit of 3/4 power of the weight increased at an average rate of approximately 1 per cent per day increase in age. The R.Q. was, on the average, 1.04 during the day and 0.92 during the night. 7. The net energy is calculated on the basis of C and N balances. A maximum of 11.8 Cal. net energy per chick per day was found at 32 degrees C. At 21 degrees C. only 6.9 Cal. net per day per chick was produced and at 40 degrees C. an average of 6.7 Cal. 8. The composition of the gained body substance changed according to the environmental temperature. The protein stored per gram increase in body weight varied from 0.217 to 0.266 gm. protein and seemed unrelated to the temperature. The amount of fat per gram gain in weight dropped from a maximum of 0.153 gm. at 32 degrees C. to 0.012 gm. at 21 degrees C. and an average of 0.107 gm. at 40 degrees C. The energy content per gram of gain in weight had its maximum of 2.95 Cal. per gm. at 38 degrees C. and its minimum of 1.41 Cal. per gm. at 21 degrees C. at which temperature the largest amount of water (0.763 gm. per gm. increase in body weight) was stored. 9. The basal metabolism increased from an average of 60 Cal. per kilo(3/4) at an environmental temperature of 40 degrees C. to 128 Cal. per kilo(3/4) at 21 degrees C. No indication of a critical temperature was found. 10. The partial efficiency, i.e. the increase in net energy per unit of the corresponding increase in food energy, seemed dependent on the environmental temperature, reaching a maximum of 72 per cent of the available energy at 38 degrees C. and decreasing to 57 per cent at 21 degrees C. and to an average of 60 per cent at 40 degrees C. 11. The total efficiency, i.e. the total net energy produced per unit of food energy taken in, was maximum (34 per cent of the available energy) at 32 degrees C., dropped to 16 per cent at 21 degrees C., and to an average of 29 per cent at 40 degrees C. PMID- 19872809 TI - THE ACCUMULATION OF ELECTROLYTES : VI. THE EFFECT OF EXTERNAL pH. AB - It would be natural to suppose that potassium enters Valonia as KCl since it appears in this form in the sap. We find, however, that on this basis we cannot predict the behavior of potassium in any respect. But we can readily do so if we assume that it penetrates chiefly as KOH. We may then say that under normal conditions potassium enters the cell because the ionic activity product (K) (OH) is greater outside than inside. This hypothesis.leads to the following predictions: 1. When the product (K) (OH) becomes greater inside (because the inside concentration of OH(-) rises, or the outside concentration of K(+) or of OH(-) falls) potassium should leave the cell, though sodium continues to enter. Previous experiments, and those in this paper, indicate that this is the case. 2. Increasing the pH value of the sea water should increase the rate of entrance of potassium, and vice versa. This appears to be shown by the results described in the present paper. It appears that photosynthesis increases the rate of entrance of potassium by increasing the pH value just outside the protoplasm. In darkness there is little or no growth or absorption of electrolytes. The entrance of potassium by ionic exchange (K(+) exchanged for H(+) produced in the cell), the ions passing as such through the protoplasmic surface, does not seem to be important. PMID- 19872810 TI - THE PHOTOTROPIC EFFECT OF POLARIZED LIGHT. AB - For the growing cell of Phycomyces, a difference in the phototropic effect of light is described depending on its plane of polarization with reference to the axis of the cell. The difference which is found is primarily due to differences in the reflection losses at the cell surface. The magnitude of the effect approximates that deduced from the theory of phototropism suggested for this system. No specific effect of plane polarized light on the growth processes of the cell need be postulated. PMID- 19872811 TI - THE GROWTH AND DURATION OF LIFE OF CELOSIA CRISTATA SEEDLINGS AT DIFFERENT TEMPERATURES. AB - Daily measurements of hypocotyl length were made on Celosia cristata seedlings cultured in darkness under aseptic conditions at six constant temperatures between 14.5 degrees and 40.5 degrees C. At 40.5 degrees roots did not penetrate the agar and only the hypocotyls that were supported by the wall of the test tube could be measured. The growth curves were of the generalized logistic type, but of different degrees of skewness. The degree of symmetry of the growth curves was influenced by temperature. At the lower temperatures the maximal growth rate came relatively late in the grand period of growth; at successively higher temperatures it came progressively earlier. The mean total time rate of growth (millimeter per diem) was found to be a parabolic function of the temperature. The maximum rate of growth was found from the curve to be at 30.48 degrees C. The maximum observed rate of growth, and the maximum yield, were found to be at 30 degrees C. At all temperatures above 14.5 degrees the maximum growth activity fell in the second quarter of the whole growth period. At all temperatures tested other than 30 degrees , and at all parts of the growth cycle, the growth yield as measured by height of hypocotyl at any given equivalent point was less than at 30 degrees . The total duration of life of the seedlings, and the duration of life after the end of the growth period (intermediate period) were inversely proportional to the mean total growth rate. The observations on Celosia cristata seedlings are thus in accord with the "rate of living" theory of life duration. The optimal temperature for life duration is the minimum temperature, within the range of these observations. PMID- 19872812 TI - BOUND WATER IN MUSCLE. AB - 1. The amount of free unfrozen water, i.e. water acting as normal solvent, in frog's muscle at temperatures below the initial freezing-point has been calculated from the vapour pressure isotherm of the muscle. 2. Significant amounts of free water are present at -20 degrees C. The total amount of unfrozen water at -20 degrees C. cannot, therefore, be taken as a measure of the bound water in muscle. 3. The calculated values of free water, when compared with experimentally determined values of total unfrozen water, indicate that the amount of bound water in muscle at various temperatures is small. 4. A temperature considerably below -20 degrees C., roughly between -40 degrees and 60 degrees C., is required to freeze completely the free water in muscle. PMID- 19872813 TI - THE INFLUENCE OF MINIMAL NARCOTIC DOSES ON THE RESPIRATION OF ERYTHROCYTES. AB - Low concentrations of ethyl alcohol stimulate the respiration of mammalian erythrocytes in vitro. Low concentrations of ethyl urethan remain without effect on, or tend slightly towards depressing the respiration of mammalian erythrocytes in vitro. It is suggested that this may be due to the oxidizable nature of alcohol, and the non-oxidizable nature of urethan, properties which come into evidence only when these narcotics are present in such low concentrations that the threshold of inhibition (narcosis) has not been reached. PMID- 19872814 TI - THE ULTRAVIOLET ABSORPTION SPECTRUM OF PEPSIN. AB - The ultraviolet absorption spectrum of Northrop's pure crystalline pepsin has been determined. The curve of calculated molecular extinction coefficients is given. There is noted a general resemblance of the absorption curve for pepsin to that for urease and tyrosine; the absorption band is maximum at 2750-2800 A.micro., minimum near 2500. A slight hump on either side of the peak of the extinction curve may be significant. PMID- 19872815 TI - STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER, AND BY FATTY ACIDS, MINERAL ACIDS, AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER. AB - 1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water. 2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water. 3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH(2) groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value. 4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water. 5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response. 6. Stimulation by sodium chloride, nitrate, and sulfate is correlated with equivalent concentrations of the salts added to sea water, or with the forces of primary valence. Although the threshold for stimulation by the salts is considerably higher than for the acids, the efficiency of stimulation by the salts is greater. PMID- 19872816 TI - MANOMETRIC MEASUREMENTS OF PHOTOSYNTHESIS IN THE MARINE ALGA GIGARTINA. AB - A manometric method for measuring photosynthesis in marine algae is described. Photosynthesis in the red alga Gigartina harveyana is shown to be similar in all important respects to photosynthesis in Chlorella and other Chlorophyceae. PMID- 19872817 TI - SEARCH FOR MITOGENETIC RADIATION BY MEANS OF THE PHOTOELECTRIC METHOD. AB - The intensity of mitogenetic radiation was estimated from data given by Gurwitsch. The sensitivity of the biological method and of the physical methods were compared. With onion-base pulp and onion roots as mitogenetic inductors, the photographic method gave no perceptible blackening for exposures up to 184 hours. A photoelectric counter tube was described with cadmium as photoelectric metal. Its sensitivity was such that a radiation intensity of 10 to 15 quanta per cm.(2) per second of the Hg line 2536 A was detectable. Spurious effects produced by the counter tube were described and means for their avoidance given. A number of different biological materials, all supposed to be excellent mitogenetic radiators, were investigated by means of the counter tube. No mitogenetic radiation could be detected. PMID- 19872818 TI - ELECTRICAL CONTROL OF RHIZOID FORMATION IN THE RED ALGA, GRIFFITHSIA BORNETIANA. AB - 1. Direct galvanic current of 10 to 40 microamperes per square millimeter of cross-section of medium results in anodal determination of rhizoid origin in the differentiated cells of the red alga Griffithsia bornetiana. The current is most effective near the upper end of the range. 2. Within the range used there is an increase in the number of rhizoids produced with increase in current intensity and a decrease in size of rhizoids. 3. Currents of lower intensity require a longer time to produce these effects than comparatively high currents. 4. The orientation of the plants in the electrical field seems to affect the number of rhizoids produced, in that plants with apexes toward the anode produce more rhizoids. 5. Together with anodal rhizoid determination there is migration of chromatophores toward the anodal side of each cell. 6. Displacement of chromatophores (and other cytoplasmic bodies) by the centrifuge does not affect the point of rhizoid origin, but does affect the shoots. 7. Together with anodal determination of rhizoids the algal filaments become graded in color, from bright pink toward the cathode to pale tan toward the anode. 8. Evidence is presented to show that this is not due to a pH change, but to a loss of pigment by chromatophores toward the anode and electrophoresis of the pigment toward the cathode. 9. In conclusion the probability is pointed out that the current acts in morphogenesis by moving particles of different charge. PMID- 19872819 TI - THE RATE OF ESCAPE OF HEMOGLOBIN FROM THE HEMOLYZED RED CORPUSCLE. AB - A theoretical treatment is given of the rate of escape of hemoglobin from the hemolyzed red corpuscle. For complete permeability of the surface, as may perhaps be produced by strong lysins, the time taken for the hemoglobin to decrease to 10 per cent of its original concentration is calculated to be 0.16 seconds (for the human cell). For dilute saponin, giving complete lysis of human cells in 3 minutes, Ponder found a time of escape of 4 seconds, from which the permeability of the membrane to the pigment is calculated to be micro(H) = 5 x 10(-5) cm./sec. PMID- 19872820 TI - THE CHLOROPHYLL UNIT IN PHOTOSYNTHESIS. AB - In six species of plants, representing four phyla, the minimum number of chlorophyll molecules present for each molecule of carbon dioxide reduced appears to lie between 2,000 and 3,000. This finding suggests the existence of a chlorophyll unit. PMID- 19872821 TI - TEMPERATURE CHARACTERISTICS FOR METABOLISM OF CHLORELLA : I. THE RATE OF O(2) UTILIZATION OF CHLORELLA PYRENOIDOSA WITH ADDED DEXTROSE. AB - The temperature characteristic for the rate of O(2) consumption by Chlorella pyrenoidosa suspended in Knop solution containing 1 per cent glucose was studied between 1 degrees and 27 degrees C. with the Warburg technic. The value of micro was found to be about 19,000 +/-1,000 cal. There is some indication of a critical temperature at 20 degrees C., with shift to a lower micro above this temperature. The effect of sudden changes in temperature on the rate of respiration and the variation of the latter with time at constant temperatures are discussed. It is concluded that the "normal" respiration (in absence of external glucose) does not appear in the determination of this temperature characteristic. PMID- 19872822 TI - CONDUCTION IN NERVE FIBRES. AB - Data by E. A. Blair and Erlanger on the voltage-capacity curves and the nerve impulse velocities of each of several fibres in the same nerve trunk are related to Rashevsky's equation for the velocity of transmission in nerve. The results lend support to Rashevsky's analysis. Other empirical relations between the velocity and the parameters of the excitation equations indicate the correctness of the hypothesis that the action current is the primary factor in transmission, which process is carried on by the electrical excitation of successive regions of the nerve fibre by means of its action current according to the ordinary laws of electrical excitation. PMID- 19872823 TI - STUDIES ON THE GROWTH HORMONE OF PLANTS : VI. THE DISTRIBUTION OF THE GROWTH SUBSTANCE IN PLANT TISSUES. AB - 1. It is shown that when plant tissues are ground with water the growth substance contained therein is inactivated by the oxidizing enzymes. 2. A simple method of extraction is described which enables the quantitative determination of growth substance in such tissues. 3. The amount and distribution of growth substance in the Avena coleoptile is determined by this method, and it is shown that while the substance does not diffuse out from the lower parts of the coleoptile, it is nevertheless present in considerable amounts, the concentration decreasing steadily with the distance from the tip. 4. Growth substance is also present in considerable amounts in Avena roots, and here also its concentration decreases steadily with distance from the tip. 5. The amount of growth substance diffusing out of root tips into dextrose agar, even during long periods of time, is not greater than the amount obtainable by direct extraction. Actual production in the root tip therefore either does not take place at all, or else takes place under quite different conditions from the production in the tip of the coleoptile. PMID- 19872824 TI - CRYSTALLINE ACETYL DERIVATIVES OF PEPSIN. AB - Crystalline pepsin has been acetylated by the action of ketene in aqueous solution at pH 4.07-5.5. As acetylation proceeds the activity decreases, the decrease being more rapid at pH 5.0-5.5 than at 4.0-4.5. Three acetyl derivatives have been isolated from the reaction mixture and obtained in crystalline form. The crystal form of these derivatives is similar to that of pepsin. Fractionation and solubility determinations show that these preparations are not mixtures or solid solutions of the original pepsin with an inactive derivative. A compound which contains three or four acetyl groups and which has lost all of its original primary amino groups can be isolated after short acetylation. It has the same activity as the original pepsin. A second derivative containing six to eleven acetyl groups has also been isolated. It has about 60 per cent of the activity of the original pepsin. A third derivative having twenty to thirty acetyl groups and about 10 per cent of the activity of original pepsin can be isolated after prolonged acetylation. The 60 per cent active derivative on standing in strong acid solution loses some of its acetyl groups and at the same time regains the activity of the original pepsin. The compound obtained in this way is probably the same as the completely active three acetyl derivative obtained by mild acetylation. These results show that acetylation of three or four of the primary amino groups of pepsin causes no change in the specific activity of the enzyme but that the introduction of acetyl groups in other parts of the molecule results in a marked loss in activity. The solubilities, amino nitrogen content, acetyl content, isoelectric point, and the specific activity have been determined by a variety of methods and found to be different from the corresponding properties of crystalline pepsin. The pH-activity curves, acid and alkali inactivation, and titration curves were not significantly different from the same respective properties of pepsin. PMID- 19872825 TI - A CONVENIENT KETENE GENERATOR. PMID- 19872826 TI - RESULTS OF IRRADIATING SACCHAROMYCES WITH MONOCHROMATIC ULTRA-VIOLET LIGHT : I. MORPHOLOGICAL AND RESPIRATORY CHANGES. AB - Effects of measured ultra-violet light on the yeast S. cerevisiae have been studied. Methods of culturing and irradiating the yeast, of estimating the nature and extent of the changes produced, and the means used in producing and measuring the radiation are given. No evidence of a stimulative action was observed. The absorbed energy did not produce an all or none effect; arbitrary criteria must be used for judging the various inhibitory and lethal effects. With increase in the incident energy diverse effects were produced until abnormal cell growth and "death" of the cells resulted. Changes in the rate of oxygen consumption did not occur until after a high proportion of the irradiated cells were so damaged that they produced abnormal cells. The shape of the curves relating effect to energy are similar for various wave-lengths but different energies are required to produce the same effect at each of the wave-lengths studied. The similarity of the curves to that for a first order reaction is noted, but attention is called to the modifying influence of accessory factors such as the age of the cells. A comparison is made of the morphological and metabolic changes on the basis of energy requirements, and their relative value as criteria in judging the effects of ultra-violet light on yeast and physiologically similar microorganisms. PMID- 19872827 TI - ELECTRICAL RESPONSES FROM THE LATERAL-LINE NERVES OF FISHES : V. RESPONSES IN THE CENTRAL NERVOUS SYSTEM. AB - Records of spontaneous discharge of nerve impulses, similar to that previously described in catfish and in trout, have been obtained from lateral-line nerves of goldfish and perch, by the use of concentric micro electrodes slipped under the nerve in situ. These impulses have been followed into the central nervous system. They enter the tuberculum acusticum and thence apparently spread diffusely through the cerebellum. Cutting the lateral-line nerve on one side silences the ipsilateral tuberculum acusticum, but only reduces the intensity of ipsilateral cerebellar activity. Cutting the remaining lateral-line nerve silences activity throughout the tuberculum acusticum and the cerebellum. The maintenance of tonic activity in the tuberculum acusticum by way of lateral-line discharge may account for the inhibitory effects of the lateral-line system on auditory responses. PMID- 19872828 TI - THE "BOUND" WATER OF BIOLOGICAL COLLOIDS: A REPLY. AB - The objection by Bull to the estimation of bound water by ultrafiltration, because of an assumed adsorption of the reference substance, has been found invalid for glucose. No adsorption of glucose by the proteins, casein and gelatin, could be detected. The estimation of the bound water of proteins from the probable surface adsorption of water by proteins leads to only a small value. PMID- 19872829 TI - ON THE THEORETICAL SIGNIFICANCE OF TALBOT'S LAW. AB - On the assumptions (1) that the state of the photoreceptor is completely determined by its previous history in respect of exposure to light, (2) that photoreception involves two opposed processes, one of which is light-sensitive, and (3) that sensation is determined by the rate of the light-sensitive process integrated over a short period, it is shown that Talbot's law has as a necessary consequence that the velocity of the light-sensitive process must be directly proportional to the intensity of the stimulating light. PMID- 19872830 TI - THE PREPARATION OF THE GRADED COLLODION MEMBRANES OF ELFORD AND THEIR USE IN THE STUDY OF FILTERABLE VIRUSES. AB - 1. The method described by Elford for the preparation of graded collodion membranes suitable for ultrafiltration was found to give excellent results, and his findings are fully confirmed. 2. A formula is given for the preparation of collodion from which satisfactory membranes of graded porosity can be prepared. 3. The technique and apparatus used in the preparation, and standardization of membranes are described in detail. 4. The technique and apparatus required for ultrafiltration experiments are described, and some drawbacks encountered in the experiments are discussed. 5. The results of ultrafiltration experiments show that the pores of the membranes are remarkably uniform in size. PMID- 19872831 TI - THE EXTINCTION OF REFLEXES IN SPINAL MICE OF DIFFERENT AGES AS AN INDICATOR OF THE DECLINE OF ANAEROBIOSIS. AB - In spinal mice the latent period between decapitation and the disappearance of all spinal reflexes decreases regularly with increasing age (Fig. 1). Available evidence indicates that this latent period may be proportional to the capacity for anaerobic metabolism at various ages. PMID- 19872832 TI - THE APPLICATION OF QUANTUM MECHANICS TO CERTAIN CASES OF HOMOGENEOUS CATALYSIS. I. AB - 1. The activation energy for the hydrolytic breaking of a peptid linkage has been calculated from quantum mechanical considerations. 2. The relative catalytic effects of H(+) and OH(-) and the mechanism of these effects have been calculated and discussed. 3. These effects are both qualitatively and semiquantitatively in agreement with experiment. PMID- 19872833 TI - TEMPERATURE CHARACTERISTICS FOR THE METABOLISM OF CHLORELLA : II. THE RATE OF RESPIRATION OF CULTURES OF CHLORELLA PYRENOIDOSA AS A FUNCTION OF TIME AND OF TEMPERATURE. AB - The respiration of the green alga Chlorella pyrenoidosa, suspended in Knop's solution, has been studied in the dark as a function of time and of temperature. The rates of oxygen consumption and of carbon dioxide production (at constant temperature) decline for about 25 hours to a low, constant level. From an analysis of the curves it is suggested that two substances, A and B, are utilized, whose respiratory quotients are 1 and 0.65 respectively. The values of the temperature characteristics were found to be: for oxidation of A, 19,500 (0.6 to 11.5 degrees C.) and 3,500 (11.5 to 28 degrees C.); for oxidation of B, 5,600 (23.4 to 0.6 degrees C.). PMID- 19872834 TI - TEMPERATURE CHARACTERISTICS FOR THE METABOLISM OF CHLORELLA : III. THE CATALYTIC DECOMPOSITION OF HYDROGEN PEROXIDE BY CHLORELLA PYRENOIDOSA. AB - The decomposition of hydrogen peroxide by intact Chlorella cells follows a first order course at very low temperatures, but at higher temperatures gives falling first order constants. Between 0.6 degrees and 20 degrees C. the value of micro is 10,500 calories. PMID- 19872835 TI - NATURE OF THE ACTION CURRENT IN NITELLA : I. GENERAL CONSIDERATIONS. AB - The outstanding features of the action curve in Nitella are explained as due to the movement of potassium ions accompanied by increase of permeability. This may be useful as a working hypothesis since it accounts not only for the normal behavior but also for many striking deviations which will be treated in subsequent papers. The views here set forth are in harmony with the local circuit theory of stimulation. PMID- 19872836 TI - THE KINETICS OF PENETRATION : IX. MODELS OF MATURE CELLS. AB - To imitate cells which have ceased to grow we have made models in which artificial sap is separated from the external solution by a non-aqueous layer (representing the protoplasm). A stream of CO(2) is bubbled through the artificial sap to imitate its production by the living cell. Potassium passes from the external solution through the non-aqueous layer into the artificial sap and there reacts with CO(2) to form KHCO(3): its rate of entrance depends on the supply of CO(2). Hence the increase of volume depends on the supply of CO(2) (as is probably true of the living cell). By regulating the supply of CO(2) and the osmotic pressure we are able to keep the volume and composition of the artificial sap approximately constant while maintaining a higher concentration of potassium than in the external solution. In these respects the model resembles certain mature cells which have ceased to grow. PMID- 19872837 TI - THE ACCUMULATION OF ELECTROLYTES : VII. ORGANIC ELECTROLYTES PART 1. AB - The inorganic constituents of the sap of Rheum (rhubarb), Rumex (field sorrel), and Oxalis (wood sorrel) show a great preponderance of cations over anions, as would be expected if the cations entered chiefly as hydrates (other possibilities will be discussed in Part 2). PMID- 19872838 TI - RESULTS OF IRRADIATING SACCHAROMYCES WITH MONOCHROMATIC ULTRA-VIOLET LIGHT : II. THE INFLUENCE OF MODIFYING FACTORS. AB - Possible variation in the probability that absorbed quanta of ultra-violet energy will produce observable inhibitory and lethal effects in the yeast cell, due to non-uniformity in sensitivity of the different regions of the cell, may be further modified by the reproductive stage of the cell at the time of irradiation. Tests of the survival of yeast cells of 15 day and 24 hour cultures indicate that the older resting cells are more resistant to ultra-violet irradiation effects than cells undergoing rapid cell division. The effects of temperature changes within the range of normal growth are evidently small, as judged from the temperature coefficient (1.10). Possible inhibitory effects due to the action of ultra-violet radiation on the malt agar medium and to toxic substances diffused from cells killed by irradiation were not found under the conditions of the experiments. Tests of the validity of the Bunsen-Roscoe reciprocity law for variation in the intensity of the incident ultra-violet radiation up to 30 per cent indicate that for this range the rate of absorption of quanta by the cell does not produce any marked change in the lethal effects observed. PMID- 19872839 TI - RESULTS OF IRRADIATING SACCHAROMYCES WITH MONOCHROMATIC ULTRA-VIOLET LIGHT : III. THE ABSORPTION OF ULTRA-VIOLET ENERGY BY YEAST. PMID- 19872840 TI - ADAPTATION OF CUTANEOUS TACTILE RECEPTORS. II. AB - Studies of axon potentials set up by pressure stimuli applied to single cutaneous receptors in frog's skin indicate that the mechanical stimulus excites the free nerve endings directly. Adaptation to constant pressures or to intermittently applied pressures (failure of the response) may be due to the reduction of excitability of the nerve endings by potassium released under the pressure from surrounding epithelial cells. PMID- 19872841 TI - THE ABSORPTION OF ULTRA-VIOLET RADIATION BY CRYSTALLINE PEPSIN. AB - Determination of the absorption spectra of pure preparations of Northrop's crystalline pepsin inactivated by irradiation with ultra-violet light shows that the total absorption in the ultra-violet region of the spectrum increases with the degree of inactivation. This increase is especially marked between 2400 and 2750 A.u. The rate of photoinactivation is shown to be sensitive to changes in pH, increasing with lower values, and evidently bears a one-quantum relationship to the energy flux. Tests of the rate of inactivation of pepsin exposed to several different bands of the ultra-violet spectrum, in relation to the absorbed energy, indicate that the destruction spectrum of the enzyme agrees essentially with its absorption spectrum and is similar to that of urease. PMID- 19872842 TI - THE TEMPERATURE COEFFICIENT OF INACTIVATION OF CRYSTALLINE PEPSIN BY ULTRA-VIOLET RADIATION. AB - Determinations of the temperature coefficient of inactivation of pure crystalline pepsin solutions by ultra-violet irradiation give values very close to unity (1.02). PMID- 19872843 TI - THE ACCUMULATION OF ELECTROLYTES : VII. ORGANIC ELECTROLYTES PART 2. AB - Analyses have been made of the inorganic constituents of the juices expressed from the leaves of Rheum, Rumex, and Oxalis. It has been shown that in all cases there is a large excess of inorganic cations over anions in the sap, the average ratio of cations to anions being 3.8 (Part 1, p. 239). The ash analyses of plant tissues (chiefly leaves) reported in the literature have been examined critically, and it has been shown that the preponderance of inorganic cations over inorganic anions in the ash and in the sap is general. It has been concluded that the excess of inorganic cations is consistent with the view that cations pass into the protoplasm chiefly in the form of hydroxides, and are accumulated either in the form of organic salts (such as the oxalates) or in non-polar linkage. It has been concluded that practically all the potassium and sodium found in plant ash must have been present originally in the form of soluble ionogenic compounds, but that a considerable part of the calcium and magnesium may have been present originally in the form of insoluble salts or as components of non-polar compounds. The methods whereby the cations, particularly potassium, may have been accumulated have been discussed, and it has been concluded that as it does not seem very probable that they enter chiefly as nitrates or bicarbonates we may suppose that they go in to a large extent as hydrates: this is highly probable in the case which has been most carefully investigated (Valonia). PMID- 19872844 TI - THE APPLICATION OF QUANTUM MECHANICS TO CERTAIN CASES OF HOMOGENEOUS CATALYSIS : II. CERTAIN ASPECTS OF ENZYME ACTION. PMID- 19872845 TI - SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : I. METHODS OF ESTIMATION. AB - 1. Methods have been described for reducing protein S-S groups, for oxidizing protein SH groups, and for estimating protein S-S and SH groups. 2. It has been found necessary in estimating the cystine content of proteins by the Folin Marenzi method to take into account any cysteine that may be present. 3. A method for estimating the cysteine content of proteins has been described. 4. With these methods, estimations have been made of the S-S and SH groups and of the cystine and cysteine contents of a number of proteins. 5. In a denatured, but unhydrolyzed protein, the number of S-S and SH groups is equivalent to the quantity of cystine and cysteine found in the protein after hydrolysis. PMID- 19872846 TI - PRODUCTS OF THE OXIDATION OF THIOSULFATE BY BACTERIA IN MINERAL MEDIA. AB - Various cultures (previously described), which oxidize thiosulfate in mineral media have been studied in an attempt to determine the products of oxidation. The transformation of sodium thiosulfate by Cultures B, T, and K yields sodium tetrathionate and sodium hydroxide; secondary chemical reactions result in the accumulation of some tri- and pentathionates, sulfate, and elemental sulfur. As a result of the initial reaction, the pH increases; the secondary reactions cause a drop in pH after this initial rise. The primary reaction yields much less energy than the reactions effected by autotrophic bacteria. No significant amounts of assimilated organic carbon were detected in media supporting representatives of these cultures. It is concluded that they are heterotrophic bacteria. Th. novellus oxidizes sodium thiosulfate to sodium sulfate and sulfuric acid; the pH drops progressively with growth and oxidation. Carbon assimilation typical of autotrophic bacteria was detected; the ratio of sulfate-sulfur formed to carbon assimilated was 56:1. It is calculated that 5.1 per cent of the energy yielded by the oxidation of thiosulfate is accounted for in the organic cell substance synthesized from inorganic materials. This organism is a facultative autotroph. The products of oxidation of sodium thiosulfate by Th. thioparus are sodium sulfate, sulfuric acid, and elemental sulfur; the ratio of sulfate sulfur to elemental sulfur is 3 to 2. The pH decreases during growth and oxidation. The elemental sulfur is produced by the primary reaction and is not a product of secondary chemical changes. The bacterium synthesizes organic compounds from mineral substances during growth. The ratio of thiosulfate-sulfur oxidized to carbon assimilated was 125:1, with 4.7 per cent of the energy of oxidation recovered as organic cell substance. This bacterium is a strict autotroph. PMID- 19872847 TI - RESULTS OF IRRADIATING SACCHAROMYCES WITH MONOCHROMATIC ULTRA-VIOLET LIGHT : IV. RELATION OF ENERGY TO OBSERVED INHIBITORY EFFECTS. AB - Data obtained on yeast irradiated with monochromatic ultra-violet radiation has been analyzed for the number of quantum hits involved in the production of different degrees of inhibition of cell division, according to the method proposed by Mme. Curie (1929). Sufficient data are not available for a rigorous determination, but the calculated results tend to indicate that a multiple hit to kill relation is followed, that different numbers of hits are involved in the production of different degrees of inhibition, and that this number increases with increase in the degree of damage sustained. PMID- 19872848 TI - STIMULATION BY COLD IN NITELLA. AB - Sudden local chilling causes action currents to be set up in Nitella and in Chara, an effect which does not follow gradual local chilling. This may be due to a partial solidification of the non-aqueous protoplasmic surfaces which makes them susceptible to rupture by the protoplasmic streaming. This movement continues usually for several minutes after the chilling, whereas if stimulation occurs at all it occurs immediately on chilling. It is found that a chilled spot is much more sensitive to mechanical stimulation than is a spot at room temperature. Chilling is accompanied by a rise of resistance, a lowered rate of recovery following stimulation, and usually by a falling off in the magnitude of the action curve. PMID- 19872849 TI - POSITIVE VARIATIONS IN NITELLA. AB - The reversible electrical variations hitherto described for plants and animals consist in a reversible loss of positive potential at a stimulated spot by which it becomes more negative. In this paper we describe changes which consist in a reversible loss of negative potential at a stimulated spot whereby it becomes more positive. We suggest that this be called a positive variation. The stimulation was produced in all cases by pinching or bending the cell. This produced a compression wave which traveled along the cell, producing a negative variation at a spot which was positive and a positive variation at a spot which was negative (due to application of 0.1 M KCl). The response produced by the compression wave differs in several respects from an ordinary propagated negative variation and may be termed a positive mechanical variation. PMID- 19872850 TI - NATURE OF THE ACTION CURRENT IN NITELLA : II. SPECIAL CASES. AB - The action curve involves four movements each of which shows considerable variation. These variations can be accounted for on the assumption that the action curve is due to the movement of potassium ions accompanied by an increase in permeability. PMID- 19872851 TI - THE LIGHT GROWTH RESPONSE AND THE GROWTH SYSTEM OF PHYCOMYCES. AB - 1. The Roscoe-Bunsen law holds for the light growth response of Phycomyces if the time component of stimulation is short. With exposures longer than a few seconds, the reaction time to light is determined by the intensity and not by the energy of the flash. 2. The possible nature of the very long latency in the response to light is considered in terms of the structure of the cell and its mechanism of growth. It is suggested that during the latency some substance produced by light in the protoplasm is transported centrifugally to the cell wall or outermost layer of protoplasm. 3. The total elongation occurring over a period of 1 to 2 hours is independent of flashes of light or temporary darkening. Light acts by facilitating some change already under way in the growth system, and during the principal phase of elongation is not a necessary or limiting factor for growth. 4. Judged by the reaction time, the original sensitivity is restored in the light system following exposure to light in about one-third the time required for equilibrium to be reattained in the growth system. PMID- 19872852 TI - SOME TEMPERATURE CHARACTERISTICS IN MAN. AB - The value of micro = 29,400 has been found for the human heart beat over the temperature range of approximately 4.7 degrees C. This value is different from that of 24,000 calories which has been obtained for the effect of temperature on judgments of short durations. The evidence indicates that the estimation of short time intervals is controlled by a chemical master reaction which is independent of the pulse rhythm. PMID- 19872853 TI - PROTOPLASMIC POTENTIALS IN HALICYSTIS : IV. VACUOLAR PERFUSION WITH ARTIFICIAL SAP AND SEA WATER. AB - Perfusion of the vacuole of living cells of Halicystis is described, the method employing two longitudinally fused capillaries as entrance and exit tubes. Natural sap, artificial sap, and sea water have been successfully perfused, with various additions and deficiencies, within the limits of physiological balance. In H. ovalis the P.D. remains positive and scarcely reduced in value when normal sea water, at pH 8.1, is perfused in the vacuole. In H. Osterhoutii the P.D. reverses in sign when the perfused solution has a higher pH than 6.5. In both cases a large P.D. persists when the solutions are the same on both sides of the protoplasm. In the absence of external gradients, there must be some internal gradient or asymmetry of the protoplasm itself to account for the P.D. Since appreciable currents are produced, there must be some metabolic activity as a source of energy. The higher normal P.D. in H. ovalis is not due to the higher KCl content of its sap (as earlier suggested by the author) since it persists nearly unchanged when sea water is substituted for sap. PMID- 19872854 TI - THE SPREADING OF PEPSIN AND OF TRYPSIN. PMID- 19872855 TI - AN APPARATUS FOR PRESSURE MEASUREMENTS OF SPREADING SUBSTANCES. PMID- 19872856 TI - CRYSTALLINE CHYMO-TRYPSIN AND CHYMO-TRYPSINOGEN : I. ISOLATION, CRYSTALLIZATION, AND GENERAL PROPERTIES OF A NEW PROTEOLYTIC ENZYME AND ITS PRECURSOR. AB - A new crystalline protein, chymo-trypsinogen, has been isolated from acid extracts of fresh cattle pancreas. This protein is not an enzyme but is transformed by minute amounts of trypsin into an active proteolytic enzyme called chymo-trypsin. The chymo-trypsin has also been obtained in crystalline form. The chymo-trypsinogen cannot be activated by enterokinase, pepsin, inactive trypsin, or calcium chloride. There is an extremely slow spontaneous activation upon standing in solution. The activation of chymo-trypsinogen by trypsin follows the course of a monomolecular reaction the velocity constant of which is proportional to the trypsin concentration and independent of the chymotrypsinogen concentration. The rate of activation is a maximum at pH 7.0-8.0. Activation is accompanied by an increase of six primary amino groups per mole but no split products could be found, indicating that the activation consists in an intramolecular rearrangement. There is a slight change in optical activity but no change in molecular weight. The physical and chemical properties of both proteins are constant through a series of fractional crystallizations. The activity of chymo-trypsin decreases in proportion to the destruction of the native protein by pepsin digestion or denaturation by heat or acid. Chymo-trypsin has powerful milk clotting power but does not clot blood plasma and differs qualitatively in this respect from the crystalline trypsin previously reported. It hydrolyzes sturin, casein, gelatin, and hemoglobin more slowly than does crystalline trypsin but the hydrolysis of casein is carried much further. The hydrolysis takes place at different linkages from those attacked by trypsin. The optimum pH for the digestion of casein is about 8.0-9.0. It does not hydrolyze any of a series of dipeptides or polypeptides tested. Several chemical and physical properties of both proteins have been determined. PMID- 19872857 TI - A METHOD FOR DETERMINING THE RENNET ACTIVITY OF CHYMO-TRYPSIN. AB - The rennet activity of chymo-trypsin (or pepsin) is conveniently measured by allowing a standard solution of milk to which chymotrypsin has been added to flow slowly through a graduated pipette and observing the rate and distance of flow of the milk before it clots. The time required for chymo-trypsin to clot milk may be calculated from these observations. The rennet activity is expressed as the reciprocal of the time in minutes required for 1 ml. of enzyme solution to clot 10 ml. of standard milk powder solution. PMID- 19872858 TI - THE CONDUCTIVITIES OF AQUEOUS SOLUTIONS OF GLYCINE, d,l-VALINE, AND l-ASPARAGINE. AB - 1. The conductivities of aqueous solutions of glycine, d,l-valine, and l asparagine have been determined, and comparisons have been made with similar data reported in the literature. 2. On the basis of certain theoretical considerations, calculations of the expected conductivities of aqueous solutions of glycine, asparagine, aspartic acid, and glutamic acid have been made and these data have been compared with similar data obtained experimentally. 3. The dissociation constants of the carboxyl groups of aspartic acid and glutamic acid have been calculated from conductivity data. 4. It is shown that alanine has no effect on the ionic atmosphere of solutions of potassium chloride. PMID- 19872859 TI - OSMOTIC RELATIONSHIPS IN THE HEN'S EGG AS DETERMINED BY RELATIVE VAPOR PRESSURES. AB - It has been shown by a comparison of the relative vapor pressures of egg yolk and egg white before and after the addition of sodium chloride to the white that the osmotic pressure of the yolk is greater than that of the white. PMID- 19872860 TI - FREEZING POINTS OF ANTI-COAGULANT SALT SOLUTIONS. AB - By a method involving equilibration of ice and solution, and analysis of the solution, freezing point depressions of solutions of sodium citrate, oxalate, and fluoride have been determined over the range Delta = 0.45 to 0.65 degrees C. Determinations with sodium chloride solutions have confirmed the accuracy of the method. In each case the freezing point depression is given, within 0.002 degrees C., as a linear function of the concentration. By the use of these linear equations it is possible to prepare a solution of any of these four salts isotonic with a given biological fluid of known freezing point, provided the latter falls within the range studied. PMID- 19872861 TI - TEMPERATURE CHARACTERISTICS FOR HEART BEAT FREQUENCY IN MICE. AB - An apparatus is described which permits the simultaneous recording of body temperature and heart beat frequency in young mice. When heart beat frequency is related to body temperature the values of the temperature characteristic for the inbred albino strain used are 22,400- calories over the range 15 to 20 degrees +, 16,000+/- calories from 20+ to 27 degrees , and 11,000+/- calories from 27 to 35 degrees +. PMID- 19872862 TI - NATURE OF THE ACTION CURRENT IN NITELLA : III. SOME ADDITIONAL FEATURES. AB - Several forms of the action curve are described which might be accounted for on the ground that the outer protoplasmic surface shows no rapid electrical change. This may be due to the fact that the longitudinal flow of the outgoing current of action is in the protoplasm instead of in the cellulose wall. Hence the action curve has a short period with a single peak which does not reach zero. On this basis we can estimate the P.D. across the inner and outer protoplasmic surfaces separately. These P.D.'s can vary independently. In many cases there are successive action currents with incomplete recovery (with an increase or decrease or no change of magnitude). Some of the records resemble those obtained with nerve (including bursts of action currents and after-positivity). PMID- 19872863 TI - ELECTRICAL FACTORS INFLUENCING THE RATE OF FILTRATION OF AQUEOUS ELECTROLYTE SOLUTIONS THROUGH CELLOPHANE MEMBRANES. AB - The mechanisms by which electrokinetic factors might influence the filtration rate of aqueous electrolyte solutions through membranes are discussed. The filtration rate of a thorium chloride solution in which the membrane is isoelectric is compared with those of other solutions. The maximum filtration rate is found at the isoelectric concentration, the rate falling as the electrokinetic potential increases. The results demonstrate an inverse relation between the electrokinetic potential and the filtration rate but do not permit the evaluation with any great exactitude of the respective roles played by the two proposed mechanisms, namely, a stream potential-electroosmotic back-transport and a variation in effective pore diameter due to an orientation of water dipoles determined by electrical factors. Evidence is presented that Lepeschkin's membrane resistance is an artifact. PMID- 19872864 TI - A COMPARISON OF THE ELECTROPHORETIC VELOCITIES OF CELLOPHANE AND COLLODION SUSPENSIONS WITH ELECTROOSMOTIC VELOCITIES THROUGH MEMBRANES OF THE SAME MATERIALS. AB - It is demonstrated that the isoelectric concentration of ThCl(4) is much greater for electroosmosis in small-pored membranes (cellophane, collodion) than for electrophoresis of particles of the same material. An explanation for the difference is advanced, based on the influence of the small pores in preventing complete development of the electrical double layer. PMID- 19872865 TI - STUDIES ON BLOOD COAGULATION : I. THE ROLE OF PROTHROMBIN AND OF PLATELETS IN THE FORMATION OF THROMBIN. AB - 1. A method is described for the preparation and titration of prothrombin and thrombin. 2. Confirming the views of Morawitz, Howell (1916-17, 1925), and Bordet, thrombin cannot be regarded as an artificial by-product of coagulation (Wooldridge, Nolf (both quoted from Morawitz)). Calcium, a platelet factor, and a plasma factor (prothrombin) interact to form thrombin, and this then acts upon fibrinogen to form fibrin. The amount and rate of thrombin formation in the first reaction are independent of the presence or absence of fibrinogen. After a variable latent period, thrombin suddenly appears in large quantities, coincident with or immediately preceding the deposition of fibrin if fibrinogen is present. 3. The amount of thrombin formed in a mixture of prothrombin, Ca and platelets is independent of the platelet or Ca concentration, and depends primarily upon the amount of prothrombin used. The platelets (or cephalin) enormously accelerate the transformation of prothrombin to thrombin, and this acceleration seems to be their physiological role in the coagulation process. 4. Contrary to previous reports, platelets have not been demonstrated to contain significant quantities of prothrombin. 5. The available data do not allow any definite decision as to whether the platelet factor actually combines with prothrombin to form thrombin, or merely catalyzes the transformation. The very slow formation of thrombin in the complete absence of platelets may be due to dissolved traces of platelet material released during the physical manipulation of the plasma (centrifuging, Berkefeld filtration). 6. There was no evidence for a species-specific activity of platelets in the transformation of prothrombin to thrombin. PMID- 19872866 TI - STUDIES ON BLOOD COAGULATION : II. THE FORMATION OF FIBRIN FROM THROMBIN AND FIBRINOGEN. AB - Although calcium is essential for the formation of thrombin, it can be recovered quantitatively from formed horse thrombin without affecting its coagulating activity. Citrate also has no significant effect. As stated in the text, this does not exclude the possibility that thrombin is actually a calcium compound present in minute concentration; but confirming the results of Hammarsten, it does show that fibrin cannot be a calcium-protein compound unless one assumes molecular weights for fibrinogen greater than 1,000,000. Although the available experimental data concerning the properties of thrombin, the kinetics of its reaction with fibrinogen, and the quantitative relationships between the two do not allow a definite decision as to whether thrombin is an enzyme analogous to rennin, or whether it combines with fibrinogen to form an insoluble compound, fibrin, the weight of evidence does favor the enzyme theory. A given quantity of thrombin can form at least 200 times its weight of fibrin, and in view of the crudeness of the preparation this ratio is probably many times greater. There is no apparent stoichiometric relationship between thrombin and fibrinogen, and thrombin does not disappear from a mixture of the two until the moment of coagulation; the quantity which then disappears is many times the minimal quantity necessary to form the amount of fibrin produced. PMID- 19872867 TI - QUANTITATIVE STUDIES ON THE PHOTOLETHAL EFFECTS OF QUARTZ ULTRA-VIOLET RADIATION UPON PARAMECIUM. AB - Paramecia grown under controlled conditions were irradiated at known intensities of light of wave-lengths 2537, 2654, 2804, 3025, and 3130 A. The approximate absorption of the light by the Parmecia was found to be greatest and of the same order of magnitude at the three shortest wave-lengths, considerably less at 3025, and least at 3130 A. Paramecia did not die when irradiated with high dosages of intense light of wave-length 3130 A. At the other wave-lengths 50 per cent vesiculation occurred when between 10(12) and 10(13) quanta had been absorbed by a Paramecium. This would indicate that a very large number of molecules in a Paramecium are affected before vesiculation occurs. PMID- 19872868 TI - THE RELATION BETWEEN CHLOROPHYLL CONTENT AND RATE OF PHOTOSYNTHESIS. AB - 1. Data are presented which support the conclusion of Emerson (1929) that the rate of photosynthesis is proportional to the chlorophyll content when the latter is varied by varying the iron supply. These data give a straight line passing through the origin, which is not true of Emerson's results. 2. Similar data are presented which show that a similar relation exists when nitrogen controls the chlorophyll content. 3. Evidence is given which indicates that magnesium plays a part in the process of photosynthesis in addition to its effect upon the chlorophyll content. PMID- 19872869 TI - A PARADOXICAL RELATION BETWEEN ZETA POTENTIAL AND SUSPENSION STABILITY IN S AND R VARIANTS OF INTESTINAL BACTERIA. AB - The relation between electrokinetic potential and suspension stability of four strains of non-flagellate intestinal bacteria has been studied. The smooth forms have zeta-potentials which approximate zero over a wide range of pH and salt concentration, yet nevertheless form stable suspensions. The rough variants have zeta-potentials which vary with pH and electrolyte concentration in the familiar way. The rough forms have values of zeta-potential critical for their suspension stability. PMID- 19872870 TI - A PHYSICAL-CHEMICAL DIFFERENCE IN ANTIBODIES AGAINST THE S AND R VARIANTS OF A SINGLE BACTERIAL STRAIN. AB - 1. Rabbits were immunized with Bact. typhosum 0 901 S and 0 901 R, over a long period. Homologous and heterologous strains were sensitized with sera obtained from weekly bleedings. Agglutination titer was recorded, and the isoelectric points of the bacteria maximally sensitized were determined. 2. 0 901 S maximally sensitized with homologous immune serum had isoelectric points which became more alkaline as immunization progressed, covering a range of pH 4.8 to 5.5. 3. Strain 0 901 R maximally sensitized with homologous immune serum had isoelectric points which became more alkaline as immunization progressed, covering the range of pH 5.0 to 5.9. 4. Both 0 901 S and 0 901 R maximally sensitized with heterologous serum had isoelectric points lower than when sensitized with homologous serum. 5. The isoelectric points of both forms sensitized with increasing concentrations of homologous immune serum were determined. Increasing concentrations of homologous immune serum shifted the isoelectric point of 0 901 R from less than 2.2 for the unsensitized bacteria progressively to the alkaline side until the maximum values previously mentioned were reached. Increasing concentrations of homologous immune serum conferred upon 0 901 S isoelectric points which became only slightly more alkaline in maximal sensitization. 6. The electrophoretic mobilities of 0 901 S and 0 901 R, in each case maximally sensitized with homologous hyperimmune serum, were found to differ significantly over the whole range of pH studied. PMID- 19872871 TI - THE THEORY OF DIFFUSION IN CELL MODELS : II. SOLUTION OF THE STEADY STATE FOR THREE DIFFUSING SUBSTANCES. AB - The differential equations describing diffusion in cell models have been extended to include the simultaneous penetration of water and two salts. These equations have been solved for the steady state. Values for the concentrations in the steady state which may be computed from the equations compare favorably with the experimental values obtained by Osterhout, Kamerling, and Stanley. Moreover, it has been shown elsewhere that the solution for the steady state is essential to a discussion of the volume change or "growth" of phase C in the models and, by analogy, in living cells. PMID- 19872872 TI - THERMAL RECEPTION IN FISHES. AB - The reactions of catfish, sunfish, perch, and mummichog to temperature changes, as described in this paper, indicate that certain receptors supplied by the lateral-line nerve are concerned with thermal reception. PMID- 19872873 TI - STUDIES ON THE GROWTH HORMONE OF PLANTS : VII. THE FATE OF GROWTH SUBSTANCE IN THE PLANT AND THE NATURE OF THE GROWTH PROCESS. PMID- 19872874 TI - ON THE GEOTROPIC ORIENTATION OF HELIX. AB - The snail Helix nemoralis in negatively geotropic creeping orients upward upon an inclined surface until the angle of the path of progression (theta) is related to the tilt of the surface (alpha) as (Delta sin theta) (Delta sin alpha) = - const.; theta is very nearly a rectilinear function of log sin alpha. The precision of orientation (P.E.(theta)) declines in proportion to increasing sin alpha, P.E.(theta)/(theta) in proportion to theta. These facts are comprehensible only in terms of the view that the limitation of orientation is controlled by the sensorial equivalence of impressed tensions in the anterior musculature. PMID- 19872875 TI - THE EFFECTS OF RADIATIONS ON BIOLOGICAL SYSTEMS : II. IMMEDIATE AND SUBSEQUENT EFFECTS OF X-RAY IRRADIATION UPON RESPIRATION OF DROSOPHILA LARVAE. AB - By means of measurement of CO(2) respiratory rates it has been possible to observe immediate and latent effects of x-ray irradiations upon Drosophila larvae. The observations were extended over a period of several days, the duration of the prepupal period being observed also. In every instance a significant decrease in the rate of CO(2) respiration was observed immediately after irradiation. This decrease was univariant with the period of irradiation within the experimental limits. PMID- 19872876 TI - PROTECTIVE ACTION IN IRRADIATION OF AMYLASE SOLUTIONS WITH ULTRAVIOLET LIGHT. AB - Evidence has been presented which indicates that the protective action of dogs' sera in irradiation of pancreatin solutions with ultraviolet light is the result of a competitive absorption (screening action). A similar effect is found in simple pancreatin solutions for which we may account (at least to a first approximation) on the basis of assumed homogeneous absorption by a strong competitor in the solution for the radiations having inactivating power. These observations are of interest in connection with the theory of what has been called negative catalysis, especially in view of the marked effects of small quantities of the protecting substances. PMID- 19872877 TI - RESTORATION OF THE POTASSIUM EFFECT BY MEANS OF ACTION CURRENTS. AB - Treatment with distilled water removes from Nitella the ability to give the large potential difference between 0.01 M KCl and 0.01 M NaCl which is known as the potassium effect. The potassium effect may be restored by action currents. This might be explained by saying that distilled water removes from the surface a substance, R, which is responsible for the potassium effect and which moves into the surface during the action current and thereby restores the potassium effect. PMID- 19872878 TI - MECHANICAL RESTORATION OF IRRITABILITY AND OF THE POTASSIUM EFFECT. AB - Treatment of Nitella with distilled water apparently removes from the cell something which is responsible for the normal irritability and the potassium effect, (i.e. the large P.D. between a spot in contact with 0.01 M KCl and one in contact with 0.01 M NaCl). Presumably this substance (called R) is partially removed from the protoplasm by the distilled water. When this has happened a pinch which forces sap out into the protoplasm can restore its normal behavior. The treatment with distilled water which removes the potassium effect from the outer protoplasmic surface does not seem to affect the inner protoplasmic surface in the same way since the latter retains the outwardly directed potential which is apparently due to the potassium in the sap. But the inner surface appears to be affected in such fashion as to prevent the increase in its permeability which is necessary for the production of an action current. The pinch restores its normal behavior, presumably by forcing R from the sap into the protoplasm. PMID- 19872879 TI - STUDIES ON THE ELIMINATION OF DYES IN THE GASTRIC AND PANCREATIC SECRETIONS, AND INFERENCES THEREFROM CONCERNING THE MECHANISMS OF SECRETION OF ACID AND BASE. AB - 1. All dyes appearing in gastric juice after intravenous injection in the dog are characterized by having their chromogen in the electropositive ion under suitable conditions. 2. All dyes eliminated in pancreatic juice ionize with the chromogen electronegative under proper circumstances. 3. The amphoteric characteristics of certain dyestuffs, as well as the changes in charge associated with reversible reduction in others, have been taken into consideration, and the lack of success of previous investigators in finding a common characteristic of dyes secreted by the gastric glands differentiating them from those secreted by the pancreas, has been shown to have been due to failure to take these potentialities of the dyestuffs into account. 4. Several possible hypotheses concerning the mechanism of selectivity to dyestuffs have been considered. Differences in distribution in acid, neutral, and alkaline phases will not account for selective secretion without postulating also specific membrane permeability. It is pointed out that the theory most thoroughly in accord with all the facts observed is based upon the pore concept. To restrain electronegative dyes by polar adsorption, the pores of the membranes of the gastric glands would have to be positively charged. Such pores would constitute an electrostatic filter, restraining from passage all mobile ions of the same charge. The anions, which in plasma are mostly chloride, could pass this barrier into the secretion. In order to have hydrochloric acid formation, anion exchange would have to occur, bicarbonate, lactate, or some other anion from the gland lumen returning to balance chloride entering, leaving the hydrogen ion from the weaker acid in the secretion. This tentative theory can also be seen to fit many of the facts of pancreatic secretion, where electropositive dyes are restrained, and alkali is secreted. PMID- 19872880 TI - CORRELATION OF OXIDATION AND PHOSPHORYLATION IN HEMOLYZED BLOOD IN PRESENCE OF METHYLENE BLUE AND PYOCYANINE. AB - 1. The system:hemolyzed blood + glucose never exhibits glycolysis or, in the air, oxidation of glucose. When glucose is replaced by hexosephosphate ester, addition of methylene blue causes oxidation in air. 2. When cozymase is added also, the oxidation is increased, and a synthesis of hexosephosphate esters takes place. 3. When pyocyanine is used instead of methylene blue, the rate of oxidation is the same as with methylene blue, but a synthesis of phosphate esters takes place without addition of cozymase. 4. There is never a phosphate ester synthesis without oxidation going on, but oxidation does not necessarily go hand in hand with phosphate synthesis. 5. In order to couple the oxidation process with phosphate synthesis, two methods are available: either to start oxidation by methylene blue and to add coenzyme from yeast cells; or to start oxidation by pyocyanine, in which case coenzyme is unnecessary, though it improves the effect. 6. Iodoacetate always suppresses synthesis, but only under certain conditions decreases oxidation. Cyanide has no effect upon either process. PMID- 19872881 TI - THE GEOTROPIC RESPONSE IN ASTERINA. AB - Upon a surface inclined at angle alpha Asterina gibbosa orients upward during negatively geotropic creeping until the average angle (theta) of the path is such that Delta sin theta/Delta sin alpha = const. This is true also in positively geotropic movement. The direction of orientation may be temporarily reversed by mechanical disturbance. The variation of theta is greater at low slopes. Tests with directed impressed pulls, due to an attached cork float, show that the pull upon the tube feet is of primary consequence for the determination of theta. When the component of gravitational pull in the direction of movement reaches a fraction of the total pull which is proportional to the gravitational vector parallel to the surface, the laterally acting component is ineffective. On this basis, it follows that Delta sin theta/Delta sin alpha = const. PMID- 19872882 TI - ON REVERSAL OF GEOTROPISM IN ASTERINA. AB - A certain level of strychninization induces in Asterina reversal of geotropism from the normally geonegative movement to a persistent downward creeping. The effect of an attached float producing upward pull is to induce upward creeping, under these conditions, whereas normally it leads to downward movement. This reversal cannot be regarded as due to a mere intensification of the sensory effect of tension. It must be understood as representing a true reversal of inhibition. The temporary reversal of geotropism following mechanical disturbances (in the absence of strychnine) is interpreted in the same way. PMID- 19872883 TI - ORIENTATION BY OPPOSED BEAMS OF LIGHT. AB - Computations of the effective angular inclination (H) of the photoreceptive surfaces of the two sides, based upon measurements of orientation angles under the action of beams of light directly opposed or crossing at right angles, show that with larvae of Calliphora and of Lucillia H declines as the total illumination decreases (i.e., as the angle of orientation away from the more intense light increases). H is greater with the two lights opposed at 180 degrees ; this may be due to the difference in refraction. For the more sharply pointed larvae of Lucillia, H is less than half as great as in Calliphora. PMID- 19872884 TI - ELECTROPHORESIS OF STEROLS : II. ERGOSTEROL. AB - The electrophoretic behavior of powdered ergosterol crystals is identical with that previously found for cholesterol within the limits of experimental error. Evidence for an adsorption hypothesis is presented to explain this phenomenon. PMID- 19872885 TI - ON THE RELATION OF DIRECT CURRENTS TO CONDENSER DISCHARGES AS STIMULI. AB - Data on the electrical stimulation of sciatic-gastrocnemius preparations of the frog by both direct currents and condenser discharges at the same time are discussed in relation to the validity of the differential equation See PDF for Equation where p is the local excitatory process, V the stimulating current or voltage, and K and k are constants. It is concluded that the constant k is the same whether it is derived from the data of the one stimulus or the other when the same fibres are being stimulated. PMID- 19872886 TI - A THEORY OF VISUAL INTENSITY DISCRIMINATION. AB - 1. A theory of visual intensity discrimination is proposed in terms of the photochemical events which take place at the moment when a photosensory system already adapted to the intensity I is exposed to the just perceptibly higher intensity I+DeltaI. Unlike previous formulations this theory predicts that the fraction DeltaI/I, after rapidly decreasing as I increases, does not increase again at high intensities, but reaches a constant value which is maintained even at the highest intensities. 2. The theory describes quantitatively the intensity discrimination data of Drosophila, of the bee, and of Mya. 3. With some carefully considered exceptions the intensity discrimination data of the human eye fall into two classes: those with small test areas or with red light, which form a single continuous curve describing the function of the retinal cones alone, and those with larger areas, and with white, orange, and yellow light, which form a double curve showing a clear inflection point, and represent the separate function of the rods at intensities below the inflection point and of the cones at intensities above it. 4. The theory describes all these data quantitatively by treating the rods and cones as two independently functioning photosensory systems in accordance with the well established duplicity idea. 5. In terms of the theory the data of intensity discrimination give critical information about the order of both the photochemical and dark reactions in each photosensory system. The reactions turn out to be variously monomolecular and bimolecular for the different animals. PMID- 19872887 TI - RELATION BETWEEN BIRTH WEIGHT AND LITTER SIZE IN MULTIPAROUS MAMMALS. AB - In multiparous mammals there is a definite relation between the litter size N and the total weight of the litter W. Reasons are given showing that this relationship is independent of the mechanism of parturition. For various forms W = N(K) + const. Hence the average increment of W due to unit increase of N is directly proportional to W, inversely to N. This signifies proportionality between N and nutritive drain upon the mother, as well as equipartition among the members of the litter. K is non-specific, and is therefore regarded as a partition index. PMID- 19872888 TI - ON THE MODIFICATION OF TEMPERATURE CHARACTERISTICS. I. AB - The temperature characteristics for frequency of pulsation in isolated cloacal ends of Holothuria tubulosa are micro = 20,400 from 10 to 20 degrees , 8,000 from 20 to 30 degrees . The critical temperatures 10 degrees , 20 degrees , 30 degrees are related to thermal conditions in the environment. In sea water with doubled NaCl content micro = 8,000 from 10 to 30 degrees . This is consistent with the specific nature of the temperature characteristics. The primary effect of increased NaCl is to alter the temperature characteristic curve. At low temperatures the frequency is increased, at higher temperatures diminished. The effect upon frequency is thus of less significance. It is pointed out that such relationships must be taken into account in analyzing the action of reagents upon organisms. PMID- 19872889 TI - STUDIES ON BLOOD COAGULATION : III. ON THE CONSTANCY OF THE HYDROGEN ION CONCENTRATION DURING THE COAGULATION OF FIBRINOGEN BY THROMBIN. AB - The coagulation of fibrinogen by thrombin does not involve a significant shift in the hydrogen ion concentration of the free fluid. PMID- 19872890 TI - STUDIES ON BLOOD COAGULATION : IV. THE NATURE OF THE CLOTTING DEFICIENCY IN HEMOPHILIA. AB - Despite their reported stability, the platelets of hemophilic blood function normally. The prothrombin content of such plasma is also normal. Confirming the findings of Addis, the delayed coagulation observed in hemophilic blood is due to an unexplained retarded activation of prothrombin to thrombin. The addition of an excess of platelets, whether normal, hemophilic, or animal in origin, accelerates thrombin production and makes hemophilic blood clot normally; but cephalin, despite the fact that it accelerates thrombin production in normal plasma, is unexplainedly ineffective when added to hemophilic plasma. PMID- 19872891 TI - THE ELECTRIC IMPEDANCE OF HEMOLYZED SUSPENSIONS OF MAMMALIAN ERYTHROCYTES. AB - This paper is concerned with the changes in the electric surface capacity and surface resistivity of the membrane surrounding the mammalian red corpuscle, as a result of various types of hemolysis. In the case of hemolysis with water, the cells swell with no apparent change in the electric properties of the membrane. They then hemolyze, but the membrane persists, although showing evidence of injury, as indicated by a change in the frequency dependence of its capacity and resistivity at low frequencies. The fact that a change of the frequency dependence takes place shows that the injury cannot be due merely to a rupture in the membrane, but must be due to changes in the properties (increased permeability) of the membrane as a whole. With chemical lysins (saponin, complement and amboceptor, digitonin, sodium taurocholate) a similar type of injury to the membranes of a certain number of the corpuscles takes place, to an increasing extent as the concentration of lysin is increased. The rest of the corpuscles become completely permeable to the electric current, and as the amount of lysin is increased, this number of completely permeable corpuscles increases until all are affected. This change, presumably associated with a disintegration of the corpuscle membrane, is referred to as stromatolysis, and the method gives a quantitative means of determining percentage stromatolysis. For lysis by freezing and thawing, the results obtained indicate this type of lysis to be different from that of the others studied. PMID- 19872892 TI - THE CHROMATOPHORAL NEUROHUMORS OF THE DOGFISH. AB - 1. The common dogfish, Mustelus canis, as is well known, exhibits two temporary extremes of tint, one dark, the other light. The dark phase is induced by a secretion from the pituitary gland which is carried in the blood, hence a substance soluble in water (a hydroneurohumor). The light phase is under the control of nerves and cannot be excited by blood from a light fish. 2. When an olive oil or ether extract is made from the fins of a light dogfish and this extract is injected into a dark fish, large light spots may appear in from 1 to 2 days and persist for several days. These light spots, which may be called secondary spots, are not to be confused with certain small and very temporary light spots, the primary spots, which occur soon after the injection and which are believed to be purely operative in origin. 3. The secondary light spots are not due to the death of the integumentary tissue, for, after their formation, they can be made to disappear by the action of obstetrical pituitrin and will subsequently reappear. 4. They are produced by some substance extracted from the light fins by ether or by olive oil. They are not produced by sea water, ether, or olive oil alone. 5. The extracted substance, which can resist dry heat up to at least 110 degrees C., owes its limited range of action in the dogfish to its inability to dissolve in water. It is soluble in oil (a liponeurohumor). 6. This liponeurohumor is believed to emanate from the nerve terminals concerned with the concentration of melanophore pigment and to spread through the fatty components of the integumentary cells. PMID- 19872893 TI - CORRELATION OF THE VISCOSITIES OF PROTEIN SOLUTIONS WITH THEIR ABILITY TO CRYSTALLIZE. AB - All the proteins whose viscosities in solution have been measured fall distinctly into two classes. Proteins of viscosity equal to and lower than serum albumin are readily crystallized. Proteins with viscosity equal to or greater than denatured ovalbumin have not yet been crystallized. PMID- 19872894 TI - THE EFFECT OF LIGHT INTENSITY, AREA, AND FLICKER FREQUENCY ON THE VISUAL REACTIONS OF THE HONEY BEE. AB - 1. For the phototropic reaction of bees, the stimulating effects of two illuminated fields differing in intensity and area become equal when the product of area and intensity is the same for both fields. 2. The effect of two areas differing in size and flicker frequency is the same for the bee, when the product of area and flicker frequency is equal for both fields. 3. If two patterns of the same character but varying in size and coarseness are presented to bees for free choice, a 1:1 ratio of choices is obtained when both patterns stimulate equal numbers of retinal elements alternately by transition from one state of excitation to another. PMID- 19872895 TI - THE VALIDITY OF TALBOT'S LAW FOR THE EYE OF THE HONEY BEE. AB - By presenting to bees two illuminated fields, equal in brightness, of which one is flickering and the other stationary we find that on account of the bee's positive phototropic response equal numbers of bees travel to both fields. We thus can assume that Talbot's law is valid for the eye of the bee. PMID- 19872896 TI - THE EFFECTS OF RADIATIONS ON BIOLOGICAL SYSTEMS : III. THE EFFECT OF ULTRAVIOLET LIGHT ON THE RESPIRATION OF DROSOPHILA LARVAE AND THE DURATION OF THEIR PREPUPAL PERIOD. AB - 1. Although ultraviolet irradiation of larvae did not prolong the larval stage as is the case with x-rays, the immediate effects on respiratory rates are strikingly similar. 2. Effects of irradiation at different ages were observed and also effects of successive irradiations with remarkable agreement in comparable lots. PMID- 19872897 TI - ELECTRIC IMPEDANCE OF HIPPONOE EGGS. AB - Alternating current resistance and capacity measurements have been made from 1.08 10(3) to 2.32 10(6) cycles per second on suspensions of unfertilized, fertilized, and swollen unfertilized eggs of the echinoderm Hipponoe esculenta. A simple method has been developed for measuring the volume concentration of eggs in a suspension. The membrane of the unfertilized egg is practically non-conducting at low frequencies and shows a static capacity of 0.87 microf/cm.(2) except perhaps at the highest frequencies. The equivalent specific resistance of the egg interior is 11 times that of sea water. The membrane of the fertilized egg is practically non-conducting at low frequencies and shows a static capacity 2.5 times that of the unfertilized egg except at the higher frequencies where another reactive element produces a marked effect. The internal resistance is apparently higher than that of the unfertilized egg. The static capacity per unit area of the membrane decreases as a linear function of the surface area when the eggs are swollen in dilute sea water. In 40 per cent sea water, the capacity falls to about 75 per cent of normal. PMID- 19872898 TI - THE SOLUBILITIES, APPARENT DISSOCIATION CONSTANTS, AND THERMODYNAMIC DATA OF THE DIHALOGENATED TYROSINE COMPOUNDS. AB - 1. The solubilities and differential heats of solution of d-tyrosine, dl tyrosine, diiodo-dl-tyrosine, dibromo-l-tyrosine (hydrated), dibromo-l-tyrosine (anhydrous), and dichloro-l-tyrosine (hydrated) have been determined. 2. Evidence has been advanced that dl-tyrosine is a compound. 3. From the solubility determinations at various acidities, the apparent acid and basic dissociation constants of dibromo-l-tyrosine and dichloro-l-tyrosine have been determined at 25 degrees and 40 degrees C. From these data the apparent heats of ionization have been calculated. 4. The question concerning which of the groups in l tyrosine and its dihalogenated substitution products is responsible for each dissociation constant has been discussed. PMID- 19872899 TI - VITAMIN A IN EYE TISSUES. AB - 1. Vitamin A has been found in the retinas and the combined pigment epithelia and choroid layers of frogs, pigs, sheep, and cattle. The vitamin was identified by (a) its specific absorption at 328 mmicro; (b) the blue color yielded with antimony trichloride, associated with an absorption band at about 620 mmicro; (c) anti-xerophthalmic and growth-promoting activity; and (d) quantitative relationships among the results of these three types of observation. 2. The mammalian retinas contain about 22gamma, the frog retinas about 400gamma, and the frog pigmented layers almost 2 mg. of vitamin A per gram of dry tissue. 3. With the possible exception of hepaxanthin, no other carotenoids were found in the mammalian tissues. PMID- 19872900 TI - THE RESPONSE OF SINGLE VISUAL SENSE CELLS TO LIGHTS OF DIFFERENT WAVE LENGTHS. AB - The effect of various wave lengths of visible light in the stimulation of single visual sense cells has been studied by means of the single fiber preparation from the eye of Limulus. Oscillographic records were made of the impulse discharge in a single optic nerve fiber in response to stimulation of the attached sense cell by lights of different wave lengths. Wratten monochromatic filters supplied the means for obtaining the different spectral lights; the total intensity supplied to the eye being determined by a thermopile and galvanometer. With lights of approximately equal energy content the strongest response occurs to the green region of the spectrum. The response, however, does not vary qualitatively with wave length. By the proper adjustment of intensity, responses can be obtained which are identical, impulse for impulse, for all the spectral lights used. Moreover the ratios of the intensities for the various wave lengths necessary to produce a constant response do not vary with the intensity level of the stimulating lights; there is no Purkinje effect. The single visual sense cell can gauge brightness but cannot distinguish wave length. The reciprocals of the intensities necessary to produce a constant response when plotted against wave length give the visibility curve for the single sense cell. This curve is symmetrical about a maximum at lambda520mmicro, falling off to low values in the red and violet. It closely resembles the visibility curve for human rod vision. Bundles from the optic nerve containing several active fibers whose impulses can be distinguished by differences in form and magnitude or whose attached sense cells can be located and illuminated independently were used to determine whether there is any differential sensitivity among sense cells in the same eye for different regions of the spectrum. Such a differential sensitivity has been found to exist in the eye of Limulus and may be considered a peripheral mechanism of color vision. PMID- 19872901 TI - THE SIGNIFICANCE OF THE STRUCTURE OF A MEMBRANE FOR ITS SELECTIVE PERMEABILITY. AB - The attempt is made to reconcile the two existing theories on the mechanism of selective ion permeability of the cell membrane by taking into account the molecular arrangement in the substance of the membrane. It is shown that the pore theory and the solubility theory are not contradictory, but two aspects of the same problem, one from the thermodynamic point of view, the other from the point of view of molecular theory. The dried collodion membrane is used as a model in these studies. Its different behavior towards anions and cations is explained on the ground of a quasi-crystalline structure of collodion, the NO(3)-groups acting as dipoles with the negative charge directed towards the intermolecular spaces, no matter whether these pores are of molecular dimensions or larger. In this way a continuity in the behavior of the ordinary large pored collodion membrane and the dried membrane is established, both theoretically and experimentally. Experiments, with membranes of other cellulose derivatives agree with the mechanism suggested. Membranes of cellophane and ethyl cellulose are negatively charged, membranes of cellulose acetate positively. From solutions of collodion mixed with basic dyestuffs or alkaloids membranes can be obtained more permeable to anions than to cations in contrast to the ordinary collodion membrane. Membranes can be built which give high potential differences even between two identical electrolyte solutions. The asymmetry lies here within the membrane and is artificially produced by gluing together an ordinary collodion membrane with one previously impregnated with a basic dyestuff or an alkaloid. PMID- 19872902 TI - THE KINETICS OF PENETRATION : XI. ENTRANCE OF POTASSIUM INTO NITELLA. AB - The rate of entrance of potassium into Nitella flexilis has been investigated, and it has been shown that (a) at the concentrations studied the rate is independent of the external pH between 6 and 8 but it is possible that at lower concentrations a dependence may be found; (b) that it does not vary much with the external potassium concentration between 0.01 and 0.001 M, but appears to vary more with the potassium concentration below this limit. It has also been shown that the rate is independent of the illumination, in contrast with the penetration of halides into Nitella clavata studied by Hoagland. It has been found that potassium leaves the cells in distilled water, and since this does not seem to be the result of injury, there is apparently a concentration between 0 and 0.0001 M at which potassium neither enters nor leaves the cell. In Valonia increase of external potassium increases the rate of entrance as shown in the increase in moles of potassium in the sap. In Nitella this is true below an external concentration of 0.001 M. In Valonia this increase is paralleled by the increase in entrance of water so that little or no change in concentration occurs, but in Nitella no growth occurred during the experiment and in consequence the concentration of potassium in the sap increased. It has been shown that the potassium content of the raw gelatinous sap is no greater than that of its ultrafiltrate, so that it is not possible to assume that any of the potassium is bound up in the cell in colloidal compounds. It has been pointed out that all the gradients between the sap and the external solution are unfavorable to the entrance of potassium except the potassium bicarbonate gradient. However, on other grounds entrance as potassium bicarbonate is not considered to be very probable. Various modes of entrance are discussed and it has been concluded that the subject must be investigated further before a definite answer can be given. PMID- 19872903 TI - CHEMICAL RESTORATION IN NITELLA : I. AMMONIA AND SOME OF ITS COMPOUNDS. AB - The potassium effect in Nitella (the high P.D. observed in leading off from a spot in contact with 0.01 M KCl to one in contact with 0.01 M NaCl) and the irritability can be removed by placing cells in distilled water for 2 or 3 days. They can be restored by NH(3) or by NH(4)Cl. The potassium effect can also be restored by tetraethyl ammonium chloride (no tests were made of its ability to restore irritability). PMID- 19872904 TI - STUDIES ON OSMOTIC EQUILIBRIUM AND ON THE KINETICS OF OSMOSIS IN LIVING CELLS BY A DIFFRACTION METHOD. AB - 1. Osmotic equilibrium and kinetics of osmosis of living cells (unfertilized eggs of Arbacia punctulata) have been studied by a diffraction method. This method consists of illuminating a suspension of cells by parallel monochromatic light and measuring, by means of telescope and scale, the angular dimensions of the resulting diffraction pattern from which the average volume of the cells may be computed. The method is far less laborious and possesses several advantages over direct measurement of individual cells. The average size of a large number of cells is obtained from a single measurement of the diffraction pattern and thus individual variability is averaged out. The observations can be made at intervals of a few seconds, permitting changes in volume to be followed satisfactorily. During the measurements the cells are in suspension and are constantly stirred. 2. Volumes of cells in equilibrium with solutions of different osmotic pressure have been determined. In agreement with our previous experiments, based upon direct microscope measurements, we have confirmed the applicability of the law of Boyle-van't Hoff to these cells; that is to say, the product of volume and pressure has been found to be approximately constant if allowance be made for the volume of osmotically inactive material of the cell contents. The volume of osmotically inactive material was found to be, on the average, 12 per cent of the initial cell volume; in eggs from different animals this value ranged from 6 to 20 per cent. 3. Permeability to water of the Arbacia egg has been found to average, at 22 degrees C., 0.106 cubic micra of water per square micron of cell surface, per minute, per atmosphere of difference in osmotic pressure. 4. Permeability to ethylene glycol has been found to average, at 24 degrees C., 4.0 x 10(-15) mols, per square micron of cell surface, per minute, for a concentration difference of 1 mol per liter. This is in agreement with the values reported by Stewart and Jacobs. PMID- 19872905 TI - THE ELECTRICAL ACTIVATION OF PASSIVE IRON WIRES IN NITRIC ACID. AB - 1. The relation between the E. M. F. and the minimal duration of an activating current has been determined for passive iron wires in nitric acid under varying conditions of concentration of acid, duration of recovery period, and presence of surface-action compounds. 2. The characteristic intensity-duration curves resemble those of irritable living tissues with moderate speeds of response to stimulation (with chronaxies of the order of 10 to 30sigma). 3. The intensity of the current required for activation, as well as its minimal effective duration for a given intensity, increases rapidly with increase in the concentration of HNO(3). 4. The responsiveness of the iron wire to brief currents is low immediately after activation and returns progressively to the original level during the immediately following period, at first rapidly and then slowly, following a time curve resembling the corresponding curve of living tissues during the relative refractory period. 5. Surface-active compounds decrease reversibly, to a degree dependent on concentration, the responsiveness of iron wires to brief currents. 6. Conditions are described under which the iron wire is activated by the break of an already flowing constant current. PMID- 19872906 TI - THE COMBINATION OF DIVALENT MANGANESE WITH CERTAIN PROTEINS, AMINO ACIDS, AND RELATED COMPOUNDS. AB - 1. A study of the mode of combination which takes place between certain amino acids, proteins, various carboxylic acids, and certain sulfonic acids and manganous ions to form complexes is reported. 2. Three criteria for complex formation were used: (a) the equilibrium between the substance under test and manganous ions dissolved in aqueous buffered solution and isonitrosoacetophenone dissolved in chloroform; (b) the electrophoretic migration of manganese in the presence of the test substance with varying pH; and (c) anomalous titration. 3. The following classes of substances were found to possess the necessary groupings to form manganese complexes: hydroxy-monocarboxylic acids (lactic, gluconic), dicarboxylic acids (oxalic, malonic), hydroxy-, di- and tricarboxylic acids (citric, tartaric), dicarboxylic amino acids (aspartic, glutamic), certain inorganic acids (phosphoric, sulfuric), certain phosphoric acid-containing compounds (nucleic, glycerophosphoric), certain aromatic enol sulfonic acids (phenolsulfonic, catecholsulfonic), and certain proteins (casein, edestin, gelatin). 4. A correlation between the amount of manganese bound by the several proteins and the free carboxyl and phosphoric acid groups has been made. 5. An explanation based on the residual charge of certain atoms is advanced for the manner in which divalent manganese may be united by the compounds studied. PMID- 19872907 TI - INCREASED PERMEABILITY TO WATER OF AGING UNFERTILIZED EGGS (ARBACIA PUNCTULATA). AB - 1. Unfertilized Arbacia eggs, subjected to 50, 60, or 80 per cent sea water, at the same temperature, pH, and duration, swelled progressively faster with age. Swelling increased 12.2 to 39.6 per cent. 2. Permeability to water was calculated by the method of Lucke and McCutcheon. For freshly shed eggs from nine different females, permeability varied from 0.078 to 0.124, or 59 per cent. This variation was not due to differences in age nor to physiologic condition but was correlated with size of eggs. 3. About twenty eggs were tested each age to 60 hours after shedding. The permeability rate increased with age in all nine experiments. 4. The total increase ranged from 30 to 69 per cent. 5. The increase was slow but constant or almost constant during early and intermediate ages. 6. The increase began at earliest ages. 7. An increase may not be demonstrable for any short interval but is readily demonstrable for longer intervals (6 or more hours), or, from the entire curve. 8. Permeability increased faster at late ages. For special factors during late ages see text. 9. Injury by experimental procedure was not induced until ca. the 24th hour. Injury by aging was not detectable during the first 6 to 9 hours. It increased progressively between 10 and 24 hours, and very rapidly thereafter. Permeability increased at approximately the same rate during early and intermediate ages. Permeability therefore was not correlated with degree of injury. 10. The troublesome factor in the permeability equation was initial size, or V(o). Several methods were used to obtain this V(o), viz. (a) extrapolations approximating known cyclical change in size, (b) extrapolations approximating control sizes, (c) constant or average of all V(o)'s, (d) maximum V(o) approximating control V(o)'s. Recalculation with these different V(o)'s gave approximately the same permeabilities. 11. The increase in permeability with age was substantially the same whether "approved," or other possible rates or average rates or range of rates be used as criteria of change. 12. When the data were recalculated by integrating the equation of Northrop, the increases in permeability with age were essentially the same as the increases calculated by the graphic method of Lucke. PMID- 19872908 TI - THE ACCUMULATION OF ELECTROLYTES : VIII. THE ACCUMULATION OF KCl IN MODELS. AB - Models are described in which KCl enters until its chemical potential becomes much greater inside than outside. The energy needed to accomplish this comes from the chemical reactions occurring in the system and the continual supply of certain materials. An important factor is the maintenance of a lower pH value inside by means of CO(2). This may be analogous to what happens in some living cells. The concentration of K(+) becomes higher inside, as happens in many living cells, but the concentration of Cl(-) does not and in this respect the model differs from many living cells. As in Valonia, potassium tends to go out as KCl when the ionic activity product (K)(Cl) is greater inside but at the same time it tends to enter as KOH since the activity product (K)(OH) is greater outside. The net result is entrance of potassium presumably because the latter process is the more rapid. PMID- 19872909 TI - THE EFFECT OF X-RAYS ON CHROMOSOMES IN DIFFERENT STAGES OF MEIOSIS. AB - 1. Pollen mother cells exposed to low dosages of x-rays at various stages show different frequencies of chromosome abnormalities in the first meiotic anaphase. 2. Maximum frequencies of abnormalities were obtained in buds irradiated in the pachytene stage of the meiotic prophase and in the preceding mitosis. 3. These results are taken to indicate that the x-ray-sensitive portions of the chromonemata are closely approximated in pairs in pachytene and in the early mitotic prophase. The significance of this in relation to non-homologous pairing is indicated. 4. From the nature of the chromosome configurations observed it is concluded that chromonemata are two-parted when they synapse and that a chromonematic division occurs between pachytene and anaphase and during the mitotic prophase. 5. The frequencies of abnormalities show a linear relationship to dosage. 6. The diameter of the sensitive volume of the chromonema is calculated and found to approximate the diameter of some known protein molecules. 7. The linkage mechanism is found to make up about 90 per cent of the total sensitive volume which corresponds with the approximate reduction in length of the chromonema from pachytene to anaphase. 8. The relation of these sensitive volumes to the gene is discussed. PMID- 19872910 TI - THE THICKNESS OF THE WALL OF THE RED BLOOD CORPUSCLE. AB - Fricke's assumption, that the dielectric constant of the erythrocyte wall is 3, is discussed. The assumption is approximately correct in the case of a solid layer of any thickness, and in the case of a liquid layer of not more than bimolecular thickness. For liquid layers of greater thickness the dielectric constant may be several times greater than 3. Calculated values based on experimental determinations are given of the dielectric constants of the polar groups of unimolecular films. PMID- 19872911 TI - INHIBITION OF PHOTOSYNTHESIS IN CHLORELLA PYRENOIDOSA BY THE IODO-ACETYL RADICAL. AB - Photosynthesis in Chlorella pyrenoidosa is inhibited by iodo-acetic acid and iodo acetamide, both of which attack the Blackman reaction. Since acetamide is without effect, the iodo-acetyl radical must be responsible. The study of the action of the acid is complicated by the fact that its ions penetrate slowly, if at all, so that negative results with this agent are without significance unless penetration can be established. The absorption spectrum of the cells is not affected by concentrations of iodo-acetamide which completely inhibit photosynthesis. This establishes that the chromophore groups of chlorophyll are not involved, and renders it unlikely that any other part of the molecule is. Inasmuch as cyanide likewise inhibits by way of the Blackman reaction, it would seem necessary to postulate that this complex can be attacked at two different loci, which may or may not be on the same molecule. The presence of the iodo-acetyl radical also gives rise to three other effects. (1) Concentrations (10(-5)M or less) too small to inhibit photosynthesis may increase the rate by interacting with the photochemical complex. (2) Concentrations (ca. 10(-4)M) which inhibit photosynthesis increase the rate of respiration. (3) Concentrations (10(-3)M or more) higher than those required to inhibit photosynthesis inhibit respiration. PMID- 19872912 TI - THE ESCAPE OF HEMOGLOBIN FROM THE RED CELL DURING HEMOLYSIS. AB - By means of measurements from cinematograph films of the time taken for human red cells to lose hemoglobin while hemolyzing, it is shown that small concentrations of saponin bring about a relatively small permeability of the cell membrane to the pigment, whereas large concentrations so destroy the membrane that the theoretical time for loss of pigment through a completely permeable membrane (0.16 second) is very nearly attained. These results are in agreement with those obtained from electrical measurements, and the dependence of permeability on lysin concentration can be explained on the basis of what is known about the rate of transformation of lysin as it reacts with the cell envelope. When cells are hemolyzed by hypotonic solutions, on the other hand, the permeability of the membrane to pigment is nearly constant, irrespective of the tonicity used to bring about lysis. PMID- 19872913 TI - THE REVERSIBLE HEAT ACTIVATION INDUCING GERMINATION AND INCREASED RESPIRATION IN THE ASCOSPORES OF NEUROSPORA TETRASPERMA. AB - The heat activation of Neurospora tetrasperma ascospores is a reversible process, since activated spores may be returned to secondary dormancy by preventing respiration, and these secondarily dormant spores may be induced to germinate by reheating. Activation of the spores brings about a large increase in respiration prior to the germination of the spores. As the spores are reversibly activated or deactivated the rate of respiration is increased or is decreased. By poisoning the cells with iodoacetamide it is possible to prevent all germination without greatly inhibiting this increase in respiration. Precisely with the beginning of germination a secondary rise in respiration occurs. The respiration of the spores is cyanide sensitive. The heat activation has a critical temperature at about 49 to 52 degrees C.; and at a constant temperature within this range, the percentage of the spores activated as plotted against the time, follows an S-shaped population curve. PMID- 19872914 TI - STUDIES IN RESPIROMETRY : IV. THE USE OF A COMPARATOR SYSTEM IN REFRACTOVOLUMETRIC RESPIROMETRY. PMID- 19872915 TI - ACTION POTENTIALS IN THE NERVOUS SYSTEM OF THE CRAYFISH : IV. INFLUENCE OF TEMPERATURE ON NERVE IMPULSES ARISING "SPONTANEOUSLY" IN ABDOMINAL GANGLIA. AB - Increase in temperature elicits an increase in the number of nerve impulses arising spontaneously from deafferented crayfish ganglia. This alteration in gross frequency gives an apparent temperature characteristic of 27,000 calories. Changes in the number of active fibers and in the frequency of discharge of individual units account for the alterations in the gross frequency. The change in number of active units gives a n value of 17,500 calories. Individual fibers fall into two groups with respect to the effect of temperature on their frequency of discharge. One of these groups exhibits a micro value of 14,500 calories and the other yields a micro value of 7,000 calories. PMID- 19872916 TI - THE ACCELERATING EFFECT OF MANGANOUS IONS ON PHAGE ACTION. AB - Dilute solutions of MnCl(2) or MnSO(4) accelerate the lytic effect of phage upon susceptible staphylococci. Under the conditions of our experiments the manganese containing mixtures lysed regularly 0.5 hour sooner than the controls. The effect is shown to be due to a lowering of the lytic threshold, i.e. the quantity of phage/bacterium requisite for lysis; Mn(++) reduces the ratio from 54 to about 12. In the presence of Mn(++) phage distribution is altered and in growing phage bacteria mixtures the extracellular phage concentration is increased by manganese to approximately 4 times that occurring in the absence of manganese. There appears to be no enhancement of phage formation nor any affect on the rate of bacterial growth. As would be anticipated, for any given initial phage concentration the end titre after completion of lysis is less in the presence of manganese than in its absence. This is due to the reduced lytic threshold produced by Mn(++), there consequently being less phage needed to bring about lytic destruction of the bacteria. PMID- 19872917 TI - ELECTROPHORESIS OF STEROLS : III. FURTHER INVESTIGATIONS OF CHOLESTEROL SURFACES. AB - 1. No significant differences were noted between the electrophoretic mobilities of unground cholesterol crystallized from alcohol, acetone, or the melted state. 2. On grinding with ice at -10 degrees C. the mobility drops to less than half (at pH 5.8) that observed in the unground state. This equilibrium condition is reached after 50 minutes grinding. Cholesterol crystals from alcohol or acetone behave identically throughout the course of this change. 3. When cholesterol crystals which have been ground with ice are dried in vacuo at room temperature they revert to the mobility of unground cholesterol. The cause of this phenomenon is discussed. 4. Both ground and unground cholesterol have an isoelectric point near pH 3.0, even after crystallization from the melted state. PMID- 19872918 TI - THE MOLECULAR WEIGHT AND ISOELECTRIC POINT OF THYROGLOBULIN. AB - 1. The sedimentation constant of hog thyroglobulin is 19.2c10(-13). That of human thyroglobulin is essentially the same. 2. The specific volume of hog thyroglobulin is 0.72. 3. The isoelectric point of native hog thyroglobulin is at pH 4.58, that of denatured thyroglobulin at pH 5.0. 4. The molecular weight of hog thyroglobulin is, in round numbers, 700,000, as calculated from the sedimentation and diffusion constants, or 650,000, as calculated from the sedimentation equilibrium data. 5. The thyroglobulin molecule deviates markedly from the spherical. PMID- 19872919 TI - THE DENATURATION OF EGG ALBUMIN BY ULTRA-VIOLET RADIATION. AB - The coagulation of isoelectric egg albumin solutions, on exposure to ultraviolet radiation, involves three distinct processes, (1) the light denaturation of the albumin molecule, (2) a reaction between the light denatured molecule and water which may be similar to heat denaturation but occurs at a lower temperature, and (3), the flocculation of the denatured molecules to form a coagulum. The light denaturation is unimolecular, independent of temperature, and occurs over a wide pH range. The reaction between the light denatured molecule and water has a temperature coefficient of 10(+) and occurs rapidly at 40 degrees C., a temperature at which heat denaturation is inappreciable. PMID- 19872920 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. IX. AB - Adult hybrid rats from the cross of races A x B show a total capacity to vary their geotropic performance which is identical with that of their B parents. The proportionate modifiable variability of geotropic orientation also agrees quantitatively with that for the B parents. These relationships are not disturbed by the action of adrenin, which leads to a distortion of the theta vs. alpha curve. Young rats of the F(1) generation show a greater proportion of unmodifiable variation of geotropic orientation. It is pointed out that the present findings support the conclusion that the capacity of rats to exhibit variation of geotropic orientation is limited by their genetically determined composition and that the special condition in the young hybrids may be understood as due to a kind of temporary disharmony of developmental events. PMID- 19872921 TI - ADAPTATION OF CUTANEOUS TACTILE RECEPTORS. III. AB - Further experimental evidence is presented indicating that the peripheral inhibitory phenomenon known as sensory adaptation, as it is manifested in tactile receptors in frogs' skin, is produced by a neurohumor released by non-nervous cells of the skin when they are pressed upon. 1. Adaptation is not produced by electrically initiated antidromic impulses backfired into the axon branches. 2. Intermittent air jet stimulation of a region of skin several millimeters distant from a responsive single ending produces failure of response of the ending to a similar direct intermittent stimulus applied to the skin containing the ending immediately afterward. 3. Constant pressure causes an ending to adapt but no spread of the effect, as described in the above paragraph, is found. This implies that the spread is the result of the vibratory movement of the skin. 4. The time curves of recovery from adaptation are inconsistent with any known properties of isolated nerve. PMID- 19872922 TI - THE DARK ADAPTATION OF THE EYE OF THE HONEY BEE. AB - Bees which are held in a fixed position so that only head movements can be made, respond to a moving stripe system in their visual field by a characteristic motion of the antennae. This reflex can be used to measure the bee's state of photic adaptation. A curve describing the course of dark adaptation is obtained, which shows that the sensitivity of the light adapted bee's eye increases rapidly during the first few minutes in darkness, then more slowly until it reaches a maximum level after 25 to 30 minutes. The total increase in sensitivity is about 1000 fold. The adaptive range of the human eye is about 10 times greater than for the bee's eye. The range covered by the bee's eye corresponds closely to the adapting range which is covered by the rods of the human eye. PMID- 19872923 TI - ELECTROKINETICS : XVII. SURFACE CHARGE AND ION ANTAGONISM. AB - 1. The question of the critical pore diameter for streaming potential is discussed. 2. The surface charge is calculated for cellulose in contact with solutions of K(3)PO(4), K(2)CO(3), K(2)SO(4), KCl, and ThCl(4). 3. The surface charge of cellulose in contact with a solution of 2 x 10(-4)N NaCl is calculated as a function of temperature and is found to show a sharp break at 39 degrees . This is interpreted in terms of the change of the specific heat of water. 4. A marked ion antagonism is found in NaCl:KCl, KCl:MgCl(2), NaCl:MgCl(2), NaCl:CaCl(2), KCl:CaCl(2), CaCl(2):MgCl(2) mixtures when the surface charge is calculated as a function of concentration. PMID- 19872924 TI - ON THE RELATION BETWEEN LITTER SIZE, BIRTH WEIGHT, AND RATE OF GROWTH, IN MICE. AB - We have been concerned with the connection between size of litter and weight of litter at birth, especially in mice. The weight at birth represents, it is to be presumed (at least in mice, and for certain other cases), the weight at a particular developmental stage. The connection between number in litter (N) and weight of litter (W) has been interpreted as due to the partition of nourishment between mother and young, and on an equal basis among the several embryos of a litter. The "heterogonic" relationship which the data exhibit between N and W shows that the constant K, defined by log W = K log N + const., is independent of the species, and has an essentially constant value (0.85+/-) in all multiparous mammals; it is therefore regarded as a partition coefficient. In the case of power function relationships between masses of components of a single individual, the respective "drawing powers" of the several organs are diverse, and diverse magnitudes of K are encountered. With developing embryos, the intrinsic drawing powers of the tissues concerned in embryos and mothers are in each case of the same general character, at least among mammals; the constancy of K reflects this. A parallel for the case as it appears in the consideration of relative growth rates of organs in a single individual, and in which the varying magnitudes of the heterogonic growth constant K are presumed to reflect diverse drawing powers of the respective tissues, would be given by intrauterine growth of a litter containing individuals with diverse capacities for growth, -that is, individuals differing genetically with respect to the factors determining the magnitudes of w(1). We have been dealing with the growth of litters in inbred strains. It is to be presumed that in the case of the growth of a litter containing two categories of individuals so far as concerns intrinsic drawing powers with respect to the nourishment provided by the mother, it would be possible to investigate the way in which K is open to modification. Although difficult, from the standpoint of classifying the individual young, it would appear to be distinctly worth while to make such an experiment, and we have planned it for the future. It is pointed out that for genetic purposes the ideal weight of a litter of 1 is obtainable from a series of measurements of N and W, free from disturbances affecting the apparent value of this quantity as observed in single births. This weight of an ideal litter of 1 should be employed to disentangle the effects of heterosis and fertility factors from those having to do with individual weight at birth. During the suckling period the relation DeltaW/W = K (DeltaN/N) is maintained for young mice, but with modifications in the case of small and large suckling litters due to (1) the time course of milk yield, and (2) the effect of litter size upon this. It is shown that a growth curve can be obtained for an ideal litter of I, under the condition of milk supply that on each day the mother is able to provide a constant fractional increase of milk for each additional young mouse in the litter. The rate of growth then adheres to the time curve of capacity for production of milk. PMID- 19872925 TI - THE ALLEGED EFFECT OF ELECTRICAL STIMULATION ON THE METABOLISM OF RED CELL SUSPENSIONS. AB - The apparent increase in the rate of O(2) consumption described when an alternating current, or induction coil current, is passed through a red cell suspension (in a buffered NaCl solution) is not a metabolic effect in any sense of the word. The passage of the current results in a permanent volume decrease in the system, and it is this which has been erroneously interpreted as an "increase in the rate of O(2) consumption." Its magnitude is about 1 part in 1000. The utilization of O(2) is not involved at all, and the same effect is obtained, on a somewhat smaller scale, when the current is passed through a solution of NaCl or of the other halogen salts. The effects occur only with shiny platinum electrodes, and disappear entirely when the electrodes are platinized. Passage of the current through serum, on the other hand, results in a permanent increase in the volume of the system, this effect also disappearing on platinization of the electrodes. The effects are apparently related to obscure electrode phenomena. PMID- 19872926 TI - ACETYLATION OF TYROSINE IN PEPSIN. AB - Crystalline 60 per cent active acetyl pepsin has 7 acetyl groups per mol of pepsin, 3 of which are readily hydrolyzed in acid at pH 0.0 or in weak alkali at pH 10.0. The tyrosine-tryptophane content of this acetylated pepsin, measured colorimetrically, is less than pepsin by three tyrosine equivalents. Hydrolysis at pH 0.0 or pH 10.0 of the 3 acetyl groups results in a concomitant increase in the number of tyrosine equivalents. In the pH 0.0 hydrolysis experiment there is also a simultaneous increase in specific activity. The phenol group of glycyl tyrosine is acetylated by ketene under the conditions used in the acetylation of pepsin and the effect of pH on the rate of acetylation is similar in the two cases. It is concluded that the acetyl groups in the 60 per cent active acetyl pepsin, which are responsible for the decrease in specific enzymatic activity, are 3 in number and are attached to 3 tyrosine phenol groups of the pepsin molecule. PMID- 19872927 TI - STUDIES ON BIOLUMINESCENCE : II. THE PARTIAL PURIFICATION OF CYPRIDINA LUCIFERIN. AB - Some solubility, oxidation, reduction, and compound-forming characteristics of extracts of Cypridina luciferin have been presented. A method of purification has been described which increased the amount of luciferin per unit of dry weight, as measured by the total light emitted, to about two thousand times that in the dry starting material. The best yields were from 50 to 65 per cent. PMID- 19872928 TI - PACEMAKERS IN NITELLA : I. TEMPORARY LOCAL DIFFERENCES IN RHYTHM. AB - A series of negative variations passing along the cell may reach a region where only every other variation registers. This condition may be temporary. It would seem to depend on a local change in the refractory period. PMID- 19872929 TI - THE VISUAL ACUITY OF THE FIDDLER-CRAB, UCA PUGNAX. AB - The visual acuity of the fiddler-crab can be measured at various illuminations by means of its response to a moving visual pattern. The method, although similar to that used by Hecht and Wolf for the bee and Hecht and Wald for Drosophila, must be modified to give consistent results. An explanation of the response to a visual pattern is given in terms of the structure of the eye. Visual acuity of the crab varies with log I as in man, the bee, and Drosophila. Hecht and Wolf's explanation of the varying visual acuity with illumination in terms of the distribution of functional ommatidia in the eye is supported to that extent. In the fiddler-crab as in man, monocular and binocular visual acuity is similar with a maximum of 0.0042 for the fiddler-crab. This agrees fairly well with visual acuities of 0.0041, 0.0038, and 0.0032 as found in the field. In man and the bee, the minimum visual angle corresponds to the minimum angle of two adjacent receptors; in Drosophila and the fiddler-crab the minimum visual angle corresponds to approximately twice the minimum angle between two adjacent receptors. PMID- 19872930 TI - THE DARK ADAPTATION OF RETINAL FIELDS OF DIFFERENT SIZE AND LOCATION. AB - The decrease in threshold shown by the eye during dark adaptation proceeds in two steps. The first is rapid, short in duration, and small in extent. The second is slow, prolonged, and large. The first is probably due to cone function; the second to rod function. In centrally located fields the two parts of adaptation change differently with area. With small, foveal fields the first part dominates and only traces of the second part appear. As the area increases the first part changes a little, while the second part covers an increasing range of intensities and appears sooner in time. Measurements with an annulus field covering only the circumference of a 20 degrees circle show most of the characteristics of a 20 degrees whole field centrally located. Similarly a 2 degrees field located at different distances from the center shows dark adaptation characteristics essentially like those of large centrally located fields whose edges correspond to the position of the central field. Evidently the behavior in dark adaptation of centrally located fields of different size is determined in the main not by area as area, but by the fact that the retina gradually changes in sensitivity from center to periphery, and therefore the larger the field the farther it reaches into peripheral regions of permanently greater sensibility. PMID- 19872931 TI - RELATION OF OXYGEN TENSION AND TEMPERATURE TO THE TIME OF REDUCTION OF CYTOCHROME. AB - The time for the appearance of the cytochrome C absorption band after shaking a suspension of bakers' yeast with various O(2)-N(2) mixtures was determined at each of six temperatures. At each temperature a linear relation between this interval-called the reduction time-and O(2) tension was found. It was shown: 1. That under our experimental conditions, absorption bands of cytochrome were seen when the O(2) tension of the suspension was reduced to, or below, a certain pressure which was found to be specific for each temperature (this pressure is provisionally considered to be identical with or very near to the "critical O(2) tension" usually found in Q(O(O2) )-O(2)-tension relationships); 2. That the x axis intercept obtained from the reduction time - O(2)-tension plot gives the value of the "critical" O(2) pressure at each temperature; 3. That the O(2) tension within the suspension is reduced by the respiratory activity of the yeast cells. An equation describing these observations is given and is used in calculating rates of O(2) consumption from measurements of reduction time of cytochrome. The average difference between the calculated values and the manometric measurements of Q(O(O2) ) was found to be 6.6 per cent. A rapid optical method of measuring rates of O(2) consumption based on the findings of these experiments is proposed for use with cytochrome-containing microorganisms. PMID- 19872932 TI - CAROTENOIDS AND THE VISUAL CYCLE. AB - 1. Carotenoids have been identified and their quantities measured in the eyes of several frog species. The combined pigment epithelium and choroid layer of an R. pipiens or esculenta eye contain about 1gamma of xanthophyll and about 4gamma of vitamin A. During light adaptation the xanthophyll content falls 10 to 20 per cent. 2. Light adapted retinas contain about 0.2-0.3 gamma of vitamin A alone. 3. Dark adapted retinas contain only a trace of vitamin A. The destruction of their visual purple with chloroform liberates a hitherto undescribed carotenoid, retinene. The bleaching of visual purple to visual yellow by light also liberates retinene. Free retinene is removed from the isolated retina by two thermal processes: reversion to visual purple and decomposition to colorless products, including vitamin A. This is the source of the vitamin A of the light adapted retina. 4. Isolated retinas which have been bleached and allowed to fade completely contain several times as much vitamin A as retinas from light adapted animals. The visual purple system therefore expends vitamin A and is dependent upon the diet for its replacement. 5. Visual purple behaves as a conjugated protein in which retinene is the prosthetic group. 6. Vitamin A is the precursor of visual purple as well as the product of its decomposition. The visual processes therefore constitute a cycle. PMID- 19872933 TI - A FORMULATION OF THE SEROLOGICAL FLOCCULATION RATE IN THE REGION OF CONSIDERABLE ANTIBODY EXCESS. AB - Attention is called to a phase of antigen-antibody reactions in which the times of flocculation are linearly proportional to the dilutions of antigen (region of considerable antibody excess), and a theoretical interpretation is offered. PMID- 19872934 TI - THE SOLUBILITIES OF l-PROLINE AND l-HYDROXYPROLINE IN WATER, THE CALCULATED HEATS OF SOLUTION, AND THE PARTIAL MOLAL VOLUME OF l-HYDROXYPROLINE. PMID- 19872935 TI - THE IMMUNOLOGICAL SPECIFICITY OF THE EUGLOBULIN AND PSEUDOGLOBULIN FRACTIONS OF HORSE AND H;MAN SERUM. AB - That portion of horse and human serum globulin precipitated by 33 per cent saturation with ammonium sulfate and precipitated on subsequent dialysis was taken as euglobulin; and the fraction precipitated between 33 and 50 per cent saturation and remaining in solution on subsequent dialysis was taken as pseudoglobulin. The sera of rabbits injected with either of these antigens gave precipitation with both. However, two distinct and fraction-specific antibodies could be demonstrated by absorbing the sera with the one antigen, and testing the supernatant fluid with the other. The experimental results are adequately explained on the basis that there are at least two antigenically distinct globulins in serum which we may term globulin I and globulin II and which are largely associated with so called euglobulin and pseudoglobulin respectively. The ordinary methods of salting out and dialysis do not effect complete separation and each globulin preparation contains a trace of the other antigen. The antisera to these euglobulin and pseudoglobulin preparations therefore contain antibodies to both antigens. Each protein solution precipitates all the antibody specific for the one antigen and in addition, by virtue of the trace of contaminating protein, precipitates a portion, and only a portion of the antibody specific for the other antigen. The fact that antisera to whole serum contain these same fraction-specific antibodies suggests that this immunological specificity is an inherent property of two globulins present as such in serum and is not an artifact induced by their precipitation and purification. Lipoids extracted from the globulins by ether, petroleum ether, and alcohol give no demonstrable reaction with antisera to these globulins; antisera absorbed with a large excess of lipoid are not affected as regards their reactivity with the original protein; and globulins extracted with ether and petroleum ether at room temperature are not affected as regards their reactivity with antisera. It is concluded that the immunological specificity of the globulin fractions as evidenced by the precipitation reaction is not determined by lipoids associated with the protein. PMID- 19872937 TI - A NOTE ON THE RELATION BETWEEN TOXICITY, RESISTANCE, AND TIME OF SURVIVAL. PMID- 19872936 TI - THE KINETICS OF PENETRATION : XII. HYDROGEN SULFIDE. AB - The rate of entrance of H(2)S into cells of Valonia macrophysa has been studied and it has been shown that at any given time up to 5 minutes the rate of entrance of total sulfide (H(2)S + S(-)) into the sap is proportional to the concentration of molecular H(2)S in the external solution. This is in marked contrast with the entrance of ammonia, where Osterhout has shown that the rate of entrance of total ammonia (NH(3) + NR(4) (+)) does not increase in a linear way with the increase in the external concentration of NH(3), but falls off. The strong base guanidine also acts thus. It has been shown that the rate of entrance of H(2)S is best explained by assuming that it enters by diffusion of molecular H(2)S through the non-aqueous protoplasmic surface. It has been pointed out that the simple diffusion requires that the rate of entrance might be expected to be monomolecular. Possible causes of the failure of H(2)S to follow this relationship have been discussed. PMID- 19872938 TI - CHEMICAL RESTORATION IN NITELLA : II. RESTORATIVE ACTION OF BLOOD. AB - Cells of Nitella exposed to distilled water lose their ability to produce action currents and to distinguish electrically between sodium and potassium. This ability was quickly restored by exposure to blood plasma deprived of calcium. Human blood and that of the cat, calf, and sheep gave essentially the same results. The active agents appear to be organic substances. PMID- 19872939 TI - SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : II. THE RELATION BETWEEN NUMBER OFSH AND S-S GROUPS AND QUANTITY OF INSOLUBLE PROTEIN IN DENATURATION AND IN REVERSAL OF DENATURATION. AB - 1. In native egg albumin no SH groups are detectable, whereas in completely coagulated albumin as many groups are detectable as are found in the hydrolyzed protein. In egg albumin partially coagulated by heat the soluble fraction contains no detectable groups, and the insoluble fraction contains the number found after hydrolysis. 2. In the reversal of denaturation of serum albumin, when insoluble protein regains its solubility, S-S groups which have been detectable in the denatured protein, disappear. 3. When egg albumin coagulates at an air water interface, all the SH groups in the molecule become detectable. 4. In egg albumin coagulated by irradiation with ultraviolet light, the same number of SH groups are detectable as in albumin coagulated by a typical denaturing agent. 5. When serum albumin is denatured by urea, there is no evidence that S-S groups appear before the protein loses its solubility. 6. Protein denaturation is a definite chemical reaction: different quantitative methods agree in estimates of the extent of denaturation, and the same changes are observed in the protein when it is denatured by different agents. A protein molecule is either native or denatured. The denaturation of some proteins can be reversed. PMID- 19872940 TI - SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : III. SULFHYDRYL GROUPS OF NATIVE PROTEINS-HEMOGLOBIN AND THE PROTEINS OF THE CRYSTALLINE LENS. AB - Hemoglobin and the proteins of the crystalline lens contain active SH groups while in the native state, the number of active groups increasing as the pH rises. All the SH groups of denatured globin and of the denatured lens proteins are active at a pH so low that practically none of the SH groups of native hemoglobin and of native lens protein are active. The effect of denaturation on the SH groups of a protein is to extend towards the acid side the pH range of their activity. It is possible to oxidize the iron-porphyrin and the SH groups of hemoglobin independently of each other. PMID- 19872941 TI - THE REDUCING GROUPS OF PROTEINS. AB - 1. Intact, unhydrolyzed proteins possess in addition to SH groups other reducing groups which can be oxidized by ferricyanide. 2. The activity of these reducing groups, like that of SH groups, is enhanced by denaturation of the protein and by increase of pH and temperature. 3. These groups differ from SH groups in the manner in which their activity is dependent on concentration of ferricyanide and time of contact with ferricyanide. 4. The activity of these groups is increased if protein SH groups are present. 5. The number and activity of these groups varies from protein to protein. 6. These groups are probably contained in the tyrosine and tryptophane components of proteins. 7. The significance of these reducing groups for an understanding of protein denaturation and the reducing properties of tissues is indicated. PMID- 19872942 TI - A KINETIC ANALYSIS OF THE ENDOGENOUS RESPIRATION OF BAKERS' YEAST. AB - The process of endogenous respiration of two strains of bakers' yeast, Saccharomyces cerevisiae, was examined kinetically. The rate of respiration with respect to time in a non-nutrient medium was found to exhibit two phases: (a) a period of constant rate of O(2) consumption and CO(2) production (R.Q. = 1) characteristic of cells with ample concentrations of stored material; (b) a first order decline in rate of respiration with respect to time, where the rate was proportional to the concentration of some substrate, S. (R.Q. = 1 throughout second phase.) The nature of this substrate was reexamined and the evidence summarized confirms the notion that it is a carbohydrate, probably glycogen. These phases of endogenous respiration were shown to depend upon the age of the culture and the amount of substrate available. PMID- 19872943 TI - THE METABOLIC SYSTEMS INVOLVED IN DISSIMILATION OF CARBOHYDRATE RESERVES IN BAKERS' YEAST. AB - Evidence is presented showing that the dissimilation of carbohydrate reserves in two strains of bakers' yeast, Saccharomyces cerevisiae, is a purely respiratory process. Endogenous respiration is KCN-labile. Our own experiments together with various accounts and data given in the literature show that the same "oxygen transporting mechanism" functions in both endogenous and exogenous metabolism. However, the lack of sensitivity of the endogenous system of reactions to low concentrations of monoiodoacetic acid, the absence of anaerobic CO(2) production, and the absence of alcohol production, demonstrate that fermentation is not involved in the dissimilation of the carbohydrate reserves. Throughout the experiments the endogenous respiration behaved functionally as a unitary system of reactions. The O(2) consumption and CO(2) production were parallel at all times; i.e., the R. Q. was consistently 1. Monoiodoacetic acid and KCN in concentrations from 10(-5) to 10(-1) molar affected both O(2) uptake and CO(2) production to the same extent. The only agents known to alter the value of the R. Q. were those which disrupted the normal protoplasmic structure, viz. grinding the cells with sand, plasmolyzing them with toluol and hypertonic salt solutions, or pressing them in a hydraulic press. These agents brought about a vigorous anaerobic CO(2) production accompanied by an accumulation of alcohol in the medium. The unitary character of endogenous respiration is exhibited only when the normal structure of the cell is kept intact; apparently it depends upon the maintenance of a chambered (or compartmental) architecture of the cell. PMID- 19872944 TI - THRESHOLD INTENSITY OF ILLUMINATION AND FLICKER FREQUENCY FOR THE EYE OF THE SUN FISH. AB - The sun-fish Lepomis responds to a moving system of stripes by a motion of its body. By changing the velocity of motion of the stripe system different flicker frequencies can be produced and thus the relation of flicker frequency to critical intensity of illumination can be studied. Threshold illumination varies with flicker frequency in such a way that with increasing flicker frequency the intensity of illumination must be increased to produce a threshold response in the fish. The curve of critical illumination as a function of frequency is made up of two distinct parts. For an intensity range below 0.04 millilambert and flicker frequencies below 10 per second, the rods are in function. For higher intensities and flicker frequencies above 10, the cones come into play. The maximum frequency of flicker which can be perceived by the fish's eye is slightly above 50 per second. The flicker curve for the eye of Lepomis can easily be compared with that for the human eye. The extent of the curve for the fish is greater at low illuminations, the fish being capable of distinguishing flicker at illuminations lower than can the human eye. The transition of rod vision to cone vision occurs for the fish and for the human eye at the same intensity and flicker frequency. The maximum frequency of flicker which can be perceived is for both about the same. PMID- 19872945 TI - ON THE VARIABILITY OF CRITICAL ILLUMINATION FOR FLICKER FUSION AND INTENSITY DISCRIMINATION. AB - From the data of experiments with bees in which threshold response is employed as a means of recognizing visual discrimination between stripes of equal width alternately illuminated by intensities I(1) and I(2), it is shown that the detectable increment of intensity DeltaI, where DeltaI = I(2) - I(1), is directly proportional to sigma(I2) (I(1) being fixed). From tests of visual acuity, where I(1) = 0 and the width of the stripes is varied, sigma(I2) = kI(2) + const.; here I(2) = DeltaI, and DeltaI/I(2) = 1. When the visual excitability of the bee is changed by dark adaptation, lambdaI identical with kDeltaI (= k' sigma(DeltaI)) = k'' I + const. For the measurements of critical illumination at threshold response to flicker, sigma(I2) (= sigma(DeltaI)) = k I(2) = k' DeltaI + const. The data for critical illumination producing threshold response to flicker in the sun-fish Lepomis show for the rods sigma(I2) = K I(2) for the cones sigma(I2) = K'(I(2) + const.). The data thus indicate that in all these experiments essentially the same visual function is being examined, and that the recognition of the production of a difference in effect by alternately illuminated stripes takes place in such a way that d (DeltaI)/d (sigma(I2)) = const., and that DeltaI is directly proportional to I (or "I(2)," depending on the nature of the experiment). It is pointed out that the curve for each of the cases considered can be gotten equally well if mean I or sigma(I) is plotted as a function of the independent variable involved in the experiment. Certain consequences of these and related facts are important for the treatment of the general problem of intensity discrimination. PMID- 19872946 TI - THE RESISTANCE OF DROSOPHILA TO ALCOHOL. AB - The mean time-to-death (t) of imaginal Drosophila of an inbred line in alcohol vapor of constant partial pressure (P) is a declining rectilinear function of P for each age. The time-to-death depends upon the diffusion into the fly of an amount of alcohol sufficient to kill. It does not depend upon any measurable property of a reaction between the substance of the fly and the alcohol which produces death. The relation between t and P is independent of temperature, but the invasion coefficient S = Deltat/DeltaP declines with age and differs for the two sexes. The first derivative of S with respect to age exhibits sharp discontinuities. The internal alcohol required to kill declines with age, varying with S. The relative variation of t, sigma(t)/t, is directly proportional to the resistance to diffusive penetration of alcohol R, where R = 1/S. The vapor pressure of alcohol estimated to kill instantaneously shows periodic fluctuations with age; these are precisely correlated with changes in the slope of S as a function of age. Periodic fluctuations of invasibility by alcohol, and of the lethal dose, are interpreted as due to the incidence of suppressed moults. It is shown that in the accumulation of deaths as a function of time (age) in a genetically uniform population of Drosophila of one sex, similar fluctuations are apparent in the rate. The statistical smoothing of such data is not legitimate. PMID- 19872947 TI - SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : IV. SULFHYDRYL GROUPS OF THE PROTEINS OF MUSCLE. AB - 1. In the denatured proteins of skeletal muscle, the ratio of SH to S-S groups is higher than in the mixed denatured proteins of other tissues, with a single exception-the proteins of the crystalline lens. 2. The number of active SH groups in the proteins of minced muscle or in any of the protein fractions of muscle is only a fraction of the number found after the proteins have been treated with a denaturing agent. 3. The SH groups of the native proteins of muscle are activated by a rise in pH. 4. The relation between pH and number of active SH groups in the proteins of minced muscle and in the various protein fractions of muscle shows that little, if any, denatured protein is present in minced muscle. PMID- 19872948 TI - THE CHANGE IN STATE OF THE PROTEINS OF MUSCLE IN RIGOR. AB - 1. When myosin is exposed to a typical denaturing agent (acid) it becomes insoluble and its SH groups are activated. 2. The same number of active SH groups is found in the soluble myosin of resting muscle as in the insoluble myosin of muscle in rigor. No activation of SH groups accompanies the formation of insoluble protein in rigor. 3. When the insoluble myosin of muscle in rigor is treated with a denaturing agent its SH groups are activated. 4. Protein coagulation as brought about by denaturing agents (heat, acid, alkali, alcohol, urea, salicylate, surface forces, ultraviolet light) is a distinctly different change from the coagulation of myosin brought about by the unknown agent in muscle. PMID- 19872949 TI - ANOMALIES IN THE ABSORPTION SPECTRUM AND BLEACHING KINETICS OF VISUAL PURPLE. AB - Visual purple from winter frogs shows an intermediate yellow color during bleaching by light; summer extractions do not. This seasonal effect can be duplicated by variations in the hydrogen ion concentration and in the temperature of the solutions. Increasing the pH approximates the summer condition, while decreasing the pH approximates the winter condition. Temperature has no effect on the bleaching of alkaline solutions but greatly influences acid solutions. At low temperatures the bleaching of add solutions resembles the winter condition, while at higher temperatures it resembles the summer condition. A photic decomposition product of frog retinal extractions is an acid-base indicator: it is yellow in acid and colorless in alkaline solution. Its color is not dependent upon light. The hydrogen ion concentration of visual purple solutions does not change under illumination, nor is there a difference in the pH of summer and winter extractions. Bile salt extractions of visual purple are usually slightly acid. The conflicting results of past workers regarding the appearance of "visual yellow" may be due to seasonal variation with its differences in temperature, or to the presence of base in the extractions. It is also possible that vitamin A may be a factor in the seasonal variation. The photic decomposition of visual purple in bile salts solution, extracted from summer frogs, follows the kinetics of a first order reaction. Visual purple from winter frogs does not conform to first order kinetics. Photic decomposition of alkaline, winter visual purple extractions also follows a first order equation. Acid, winter extractions appear to conform to a second order equation, but this is probably an artefact due to interference by the intermediate yellow. PMID- 19872950 TI - THE ELECTRICAL CHARGE OF MAMMALIAN RED BLOOD CELLS. AB - From data on the surface area and electrical mobilities of mammalian red blood cells in M/15 phosphate buffer at pH 7.4, it has been possible, with the help of the Gouy and von Smoluchowski theories, to calculate the net surface charge per cell as well as the charge per unit area. It was found that a single mammalian red cell has a net surface charge ranging from four to fifteen million electrons, depending on the species. No clear relationship between zoological classification and surface charge is apparent. It is suggested that a mechanism exists which is capable of keeping the surface density of net charge constant when comparatively large changes in surface area occur in the anemias. PMID- 19872951 TI - ELECTRIC IMPEDANCE OF ASTERIAS EGGS. AB - The alternating current resistance and capacity of suspensions of unfertilized eggs of Asterias forbesi have been measured at frequencies from one thousand to sixteen million cycles per second. The plasma membrane of the egg has a static capacity of 1.10microf/cm.(2) which is practically independent of frequency. The suspensions show a capacity dependent on frequency at low frequencies which may be attributable to surface conductance. The specific resistance of the cytoplasm is between 136 and 225 ohm cm. (4 to 7 times sea water), indicating a relatively high concentration of non-electrolytes. At frequencies above one million cycles there is definite evidence of another element of which the nucleus is presumably a part. PMID- 19872952 TI - ELECTRIC IMPEDANCE OF ARBACIA EGGS. AB - The alternating current resistance and capacity of suspensions of unfertilized and fertilized eggs of Arbacia punctulata have been measured at frequencies from 10(3) to 1.64 x 10(7) cycles per second. The unfertilized egg has a static plasma membrane capacity of 0.73 microf./cm.(2) which is practically independent of frequency. The fertilized egg has a static membrane capacity of 3.1 microf./cm.(2) at low frequencies which decreases to a value of 0.55 microf./cm.(2) at high frequencies. The decrease follows closely the relaxation dispersion of the dielectric constant if the dissipation of such a system is ignored. It is considered more probable that the effect is due to a fertilization membrane of 3.1 microf./cm.(2) capacity lifted 1.5 micro. from the plasma membrane, the interspace having the conductivity of sea water. The suspensions show a frequency-dependent capacity at low frequencies which may be attributable to surface conductance. The equivalent low frequency internal specific resistance of both the unfertilized and fertilized egg is about 186 ohm cm. or about 6 times that of sea water, while the high frequency data extrapolate to a value of about 4 times sea water. There is evidence at the highest frequencies that the current is penetrating the nucleus and other materials in the cytoplasm. If this effect were entirely due to the nucleus it would lead to a very approximate value of 0.1 microf./cm.(2) for the capacity of the nuclear membrane. The measurements do not indicate any change in this effect on fertilization. PMID- 19872953 TI - THE EFFECTS OF CURRENT FLOW ON BIOELECTRIC POTENTIAL : I. VALONIA. AB - The effect of direct current flow upon the potential difference across the protoplasm of impaled Valonia cells was studied. Current density and direction were controlled in a bridge which balanced the ohmic resistances, leaving the changes (increase, decrease, or reversal) of the small, normally negative, bioelectric potential to be recorded continuously, before, during, and after current flow, with a string galvanometer connected into a vacuum tube detector circuit. Two chief states of response were distinguished: State A.-Regular polarization, which begins to build up the instant current starts to flow, the counter E.M.F. increasing most rapidly at that moment, then more and more slowly, and finally reaching a constant value within 1 second or less. The magnitude of counter E.M.F. is proportional to the current density with small currents flowing in either direction across the protoplasm, but falls off at higher density, giving a cusp with recession to lower values; this recession occurs with slightly lower currents outward than inward. Otherwise the curves are much the same for inward and outward currents, for different densities, for charge and discharge, and for successive current flows. There is a slight tendency for the bioelectric potential to become temporarily positive following these current flows. Records in the regular state (State A) show very little effect of increased series resistance on the time constant of counter E.M.F. This seems to indicate that a polarization rather than a static capacity is involved. State B.-Delayed and non proportional polarization, in which there is no counter E.M.F. developed with small currents in either direction across the protoplasm, nor with very large outward currents. But with inward currents a threshold density is reached at which a counter E.M.F. rather suddenly develops, with a sigmoid curve rising to high positive values (200 mv. or more). There is sometimes a cusp, after which the P.D. remains strongly positive as long as the current flows. It falls off again to negative values on cessation of current flow, more rapidly after short flows, more slowly after longer ones. The curves of charge are usually quite different in shape from those of discharge. Successive current flows of threshold density in rapid succession produce quicker and quicker polarizations, the inflection of the curve often becoming smoothed away. After long interruptions, however, the sigmoid curve reappears. Larger inward currents produce relatively little additional positive P.D.; smaller ones on the other hand, if following soon after, have a greatly increased effectiveness, the threshold for polarization falling considerably. The effect dies away, however, with very small inward currents, even as they continue to flow. Over a medium range of densities, small increments or decrements of continuing inward current produce almost as regular polarizations as in State A. Temporary polarization occurs with outward currents following soon after the threshold inward currents, but the very flow of outward current tends to destroy this, and to decondition the protoplasm, again raising the threshold, for succeeding inward flows. State A is characteristic of a few freshly gathered cells and of most of those which have recovered from injuries of collecting, cleaning, and separating. It persists a short time after such cells are impaled, but usually changes over to State B for a considerable period thereafter. Eventually there is a reappearance of regular polarization; in the transition there is a marked tendency for positive P.D. to be produced after current flow, and during this the polarizations to outward currents may become much larger than those to inward currents. In this it resembles the effects of acidified sea water, and of certain phenolic compounds, e.g. p-cresol, which produce State A in cells previously in State B. Ammonia on the other hand counteracts these effects, producing delayed polarization to an exaggerated extent. Large polarizations persist when the cells are exposed to potassium-rich solutions, showing it is not the motion of potassium ions (e.g. from the sap) which accounts for the loss or restoration of polarization. It is suggested that inward currents restore a protoplasmic surface responsible for polarization by increasing acidity, while outward currents alter it by increasing alkalinity. Possibly this is by esterification or saponification respectively of a fatty film. For comparison, records of delayed polarization in silver-silver chloride electrodes are included. PMID- 19872954 TI - THE POLARIZATION CAPACITY AND RESISTANCE OF VALONIA : I. ALTERNATING CURRENT MEASUREMENTS. AB - Alternating current measurements of the effective capacity and resistance of Valonia cells were undertaken to determine whether a static or polarization capacity was responsible for the large slow time curves of counter E.M.F. produced by the flow of direct current. (For this purpose it was necessary that the cells be in the regular state.) With external contacts at the ends of ceils, a large fall of impedance occurs over the frequency range from zero to 20,000 cycles, above which the impedance is low and essentially that of the cell interior. As a first approximation to the cell circuit, a simple series-parallel circuit was employed in the bridge balance, with a resistance setting to represent the cell wall (and protoplasmic leakage), shunting the protoplasmic capacity in series with a resistance (sap plus polarization resistance). Both the capacity and its associated series resistance fall off regularly with frequency, giving curved lines on logarithmic plots against frequency, the slope of the resistance plot being steeper, and approaching that of f(-1), although curved to it. These parallel roughly the behavior of a polarizing electrode, which is also shown. Before concluding that the cell's capacity is therefore due to polarization, a further complication of the circuit was considered. This was the effect of the protoplasmic capacity distributed along the wall between the contacts. Both logically and experimentally it was shown that a distributed capacity, as represented by its approximate T-network of resistances and capacities invariant with frequency, could give rise to changes of capacity and series resistance with frequency which simulate to some extent the cellular phenomena. Distributed capacity was therefore reduced in the cells by using shorter air-gaps between the contacts, or abolished by measuring impaled cells, in which the current flow across the protoplasm was entirely radial. These measurements showed a smaller, but still significant change of capacity and of equivalent resistance (in series with it) with frequency, somewhat less than with electrodes, and probably representing the true protoplasmic behavior. It is concluded that the cells display a certain degree of polarization capacity, possibly in parallel with a static capacity invariant with frequency. This might result from an insulating (e.g. lipoid) cell surface, having a residual differential permeability to ions. This structure is consistent with other evidence showing the cells to be chiefly permeable to non-ionized, lipoid-soluble materials, but still displaying electrical effects (conductance, potential difference, polarization) ascribable to ionic mobility. PMID- 19872955 TI - STIMULATION OF FUNDULUS BY OXALIC AND MALONIC ACIDS AND BREATHING RHYTHM AS FUNCTIONS OF TEMPERATURE. AB - 1. Chemical stimulation as a function of temperature was studied by using oxalic acid in fresh and salt water and malonic acid in salt water as stimulating agents on Fundulus. According to the Arrhenius equation the following micro values were obtained for the various acid solutions between 0 and 29 degrees C.: for 0.002N oxalic in fresh water-15,800; 33,000; for 0.0008N oxalic in fresh water-15,800; 33,000; 48,000; for 0.002N oxalic in salt water-19,400; 24,100; 56,500; for 0.004N and 0.002N malonic in salt water-20,600; 65,000. At a critical temperature there is a sharp transition from one thermal increment to another. 2. The chemical processes controlling stimulation do not change with concentration, for different normalities of a single acid yield the same micro values. Distinctly different temperature characteristics were obtained for stimulation by oxalic in salt and fresh water. Likewise stimulation by oxalic and malonic in salt water yielded very different increments. This temperature study indicates that the controlling chemical reactions determining rate of response are different for the same acid in two different environments, or for two dibasic acids in the same environment. Other work indicates, however, that the fundamental stimulation system is the same for all the adds in both environments. Chemical rather than physical processes limit the rate of response since all the values are above 15,000. Stimulation depends upon a series of interrelated chemical reactions, each with its own temperature characteristic. Under varying conditions (e.g. change of temperature, environment, or acid) different chemical reactions may become the slowest or controlling process which determines the rate of response. 3. The variation of response, as measured by the probable error of the mean response time of the fish, is the same function of temperature as reaction time itself. Hence variability is not independent of reaction time and is controlled by the same catenary series of events which determine rate of response to stimulation. 4. Breathing rhythm of Fundulus as related to temperature was studied in both salt and fresh water. In salt water the temperature characteristic is 8,400 while in fresh water it is 16,400 below 9.5 degrees C., and 11,300 above this critical temperature. These micro values are typical of those which have been reported by other workers for respiratory and oxidative biological phenomena. A change in thermal increment with an alteration in environment indicates that different chemical reactions with characteristic velocity constants are controlling the breathing rhythm in salt and fresh water. PMID- 19872956 TI - EFFECT OF PROTEINS ON ELECTROPHORETIC MOBILITY AND SEDIMENTATION VELOCITY OF RED CELLS. AB - The isoelectric point of normal red cells cannot be measured but is certainly lower than that of any plasma protein. Red cells are easily damaged so that they will adsorb proteins from low concentrations. Normal red cells do not adsorb protein even from concentrated solutions, as is evidenced by the finding that the ratio of the mobility of the cells to that of the proteins themselves is at least as high in concentrated casein, albumin, gelatin, or fibrinogen solutions as in dilute. The finding that the observed mobility of red cells is unchanged or only slightly decreased when bulk viscosity is increased by added protein is interpreted as indicating that the red cell surfaces are hydrated. The aggregating effect of certain proteins has been determined and is assumed to be due to their dehydrating effect on the cells. Some types of cells, as beef, are not aggregated, presumably because they are resistant to this dehydrating effect. The difference in the behavior of different types of red cells demonstrates the importance of the nature of the cell as well as of the medium in determining the rate of aggregation and therefore of sedimentation. PMID- 19872957 TI - ELECTROKINETIC PHENOMENA : XII. ELECTROOSMOTIC AND ELECTROPHORETIC MOBILITIES OF PROTEIN SURFACES IN DILUTE SALT SOLUTIONS. AB - The ratio of electroosmotic to electrophoretic mobility of certain protein-coated surfaces is very close to 1.0, even in very dilute solutions of electrolytes. PMID- 19872958 TI - THE STRUCTURE OF THE ULTRAVIOLET ABSORPTION SPECTRA OF CERTAIN PROTEINS AND AMINO ACIDS. AB - 1. The absorption spectra of a number of proteins in the region 2500 to 3000 A. have been found to comprise from six to nine narrow bands. In consequence of variation in the relative intensity of these bands from protein to protein, the absorption curve has a characteristic configuration for each protein. 2. These bands correspond closely in position with the narrow bands which appear in the absorption spectra of tryptophan, tyrosin, and phenylalanine. Tryptophan and tyrosin each present three bands, phenylalanine shows nine. 3. The bands in the proteins are accordingly attributed to these amino acids. In the proteins the bands are displaced from the positions which they occupy in the uncombined amino acids, in most instances, by 10 to 35 A. toward longer wavelengths. 4. The absorption spectrum of Pneumococcus Type I antibody resembles that of normal pseudoglobulin but shows characteristic differences. PMID- 19872959 TI - THE BACTERICIDAL EFFECT OF ULTRAVIOLET RADIATION ON ESCHERICHIA COLI IN LIQUID SUSPENSIONS. AB - 1. The irradiation of bacteria in liquid suspension has been made possible through: (a) the use of a specially balanced physiological salt solution which is practically non-absorbing for the wave lengths used, and which is of such composition that subsequent dilution of the bacterial suspension gives the proper number of organisms; (b) special design of the exposure cell and a very thorough method of stirring which subjects each organism equally to the radiation; (c) practically complete absorption of the incident radiation, through the use of very dense suspensions, thus eliminating the necessity for a separate determination of the absorption coefficients of the bacteria for the wave lengths used. 2. The method also provides a means for determining the effects of sub lethal doses. 3. A formula is given for calculating from observed survival ratios the energy required to inactivate bacteria with ultraviolet radiation. The formula corrects for the protective action of non-viable organisms. 4. Data are given for the inactivation of 15 hour and 240 hour cultures of E. coli, washed and unwashed) and for 6-7 hour cultures, unwashed. These data are compared with those of other investigators. 5. A possible explanation for the differences in energy required to inactivate old, young, and standard cultures of bacteria is suggested. 6. The possible mechanism of the action of ultraviolet radiation on microorganisms is discussed. PMID- 19872960 TI - THE SOLUBILITY OF d-VALINE IN WATER. AB - 1. The solubility of d-valine in water has been determined over a range of 0-60 degrees . 2. The solubility of this amino acid varies with the mode of crystallization, indicating a dependence of solubility on the crystal form. PMID- 19872961 TI - THE SOLUBILITIES OF THE l-DIHALOGENATED TYROSINES IN ETHANOL-WATER MIXTURES AND CERTAIN RELATED DATA. AB - 1. The solubilities of l-tyrosine, dichloro-l-tyrosine (hydrated), dibromo-l tyrosine (anhydrous), and diiodo-l-tyrosine in ethanol-water mixtures at 25 degrees have been determined. 2. It was found that the solubilities of the dihalogenated substitution products of l-tyrosine are increased by addition of ethanol up to a certain concentration. Further addition of ethanol leads to a decrease in solubility. The solubility of l-tyrosine is decreased by addition of ethanol. 3. Dichloro-l-tyrosine (hydrated) was found to change to the anhydrous form when allowed to stand in the presence of ethanol. 4. The apparent heat of solution of diiodo-l-tyrosine in an ethanol-water mixture has been determined. 5. The solubility of dl-thyroxine at 30 degrees has been determined in urea solution, ethanol, dioxan, ethylene glycol, and propylene glycol. PMID- 19872962 TI - PIGMENTS OF THE RETINA : I. THE BULL FROG. AB - 1. The interrelations of visual purple, retinene, and vitamin A in the bull frog retina are analyzed in simple experiments, the results of which are presented in a series of automatically recorded spectra. 2. Observations are reported upon the distributions, properties, and concentrations of xanthophyll, vitamin A, and flavine in the pigmented tissues of the eye. PMID- 19872963 TI - THE DOUBLE REFRACTION OF CHITIN. AB - The double refraction of the chitinous hair of the crayfish is positive with respect to the axis of the hair, and is largely caused by the arrangement of submicroscopic, elongated chitin particles parallel to this axis (form birefringence). Using a series of relatively unreactive liquids and fluid mixtures which permeate the chitin framework, the type of curve relating double refraction and refractive index of the imbibed fluid is found to depend greatly on the chemical nature of the fluid. Either a positive or a negative residual birefringence may be found, depending on the choice of imbibing liquid. Separation of form and crystalline elements in double refraction by means of Ambronn's imbibition technique is therefore unsafe in a system like chitin, where some type of oriented association of the imbibed molecules with the chitin framework is prevalent. PMID- 19872964 TI - ON THE INDIVIDUAL CHARACTERISTICS OF ANIMAL AMYLASES IN RELATION TO ENZYME SOURCE. AB - Enzymes from various animal sources responsible for amylolytic activity as measured by a precise viscosimetric method have been investigated with regard to individual characteristics in relation to enzyme source. The principal criteria have been the course of spontaneous inactivation of preparations from different sources alone and in mixtures, and comparison of variations of relative activity with change in pH. It is strongly indicated that the observed amylolytic activity of hog pancreatin, and that of the serum of a depancreatized dog are attributable to single chemical individuals, while that of human saliva is caused principally if not entirely by a single individual, which appears to be subject to reversible dissociation. These three individuals are clearly distinguishable from each other. The amylolytic activity of dog pancreatic extract is due to the same individual found in the serum of a depancreatized dog, while that of human pancreatic extract and of human serum are due to the same chemical individual found in human saliva. Thus it may be said of the amylases studied, that specificity depended upon species source rather than organ source. Evidence of similar variations in activity with change in pH and equal sensitivity to ultraviolet light furnish strong indication that hog and human amylases have a common amylolytic radical. PMID- 19872965 TI - THE FORMATION OF MILK SUGAR : THE IN VITRO SYNTHESIS OF LACTOSE BY ACTIVE MAMMARY GLAND PREPARATIONS. AB - 1. The mammary glands of rats in the height of lactation were frozen in situ, removed, and dried in the vacuum in the frozen state. 2. The dried gland, added to pig serum, pig serum plus glucose, pig serum plus galactose, and pig serum plus lactose, then incubated at 37.5 degrees C., yielded a synthesis of non fermentable, reducing material. 3. The dried gland added to glucose solution alone and incubated at 37.5 degrees C. yielded a synthesis of a non-fermentable reducing disaccharide, having a reaction velocity of reduction resembling that of pure lactose. 4. There is a "short time" storage of some forms of lactose precursor in the active mammary gland. This precursor is non-reducing but becomes available and reducing when the gland is placed in a solution containing glucose. PMID- 19872966 TI - THE KINETICS OF THE REACTION WHICH TAKES PLACE BETWEEN IODOACETIC ACID AND GLYCINE. AB - 1. The kinetics of the reaction which takes place between glycine and iodoacetic acid was studied by means of the polarographic method. 2. On the basis of kinetic equations, evidence was obtained that (a) The reaction proceeds in two steps in which the hydrogens of the amino group are consecutively replaced by the acetyl radicals, the velocity constants being in the ratio 2:1. (b) Only the anionic form of glycine is able to react since the velocity constants at any pH are proportional to the concentration of glycine anion. (c) The reaction is of the ionic type, showing a positive salt catalysis, which, according to Bronsted's hypothesis, involves the primary and the secondary salt effects. 3. The fact that only the glycine anion is able to react was explained as being due to the existence of an unbonded pair of electrons on the nitrogen in the NH(2) group. The NH(3) (+) group, however, in which these electrons are shared by H(+), must, therefore, be inactive. PMID- 19872967 TI - THE EFFECTS OF CURRENT FLOW ON BIOELECTRIC POTENTIAL : II. HALICYSTIS. AB - The effect of direct current, of controlled direction and density, across the protoplasm of impaled cells of Halicystis, is described. Inward currents slightly increase the already positive P.D. (70 to 80 mv.) in a regular polarization curve, which depolarizes equally smoothly when the current is stopped. Outward currents of low density produce similar curves in the opposite direction, decreasing the positive P.D. by some 10 or 20 mv. with recovery on cessation of flow. Above a critical density of outward current, however, a new effect becomes superimposed; an abrupt reversal of the P.D. which now becomes 30 to 60 mv. negative. The reversal curve has a characteristic shape: the original polarization passes into a sigmoid reversal curve, with an abrupt cusp usually following reversal, and an irregular negative value remaining as long as the current flows. Further increases of outward current each produce a small initial cusp, but do not greatly increase the negative P.D. If the current is decreased, there occurs a threshold current density at which the positive P.D. is again recovered, although the outward current continues to flow. This current density (giving positivity) is characteristically less than that required to produce reversal originally, giving the process a hysteretic character. The recovery is more rapid the smaller the current, and takes only a few seconds in the absence of current flow, its course being in a smooth curve, usually without an inflection, thus differing from the S-shaped reversal curve. The reversal produced by outward current flow is compared with that produced by treatment with ammonia. Many formal resemblances suggest that the same mechanism may be involved. Current flow was therefore studied in conjunction with ammonia treatment. Ammonia concentrations below the threshold for reversal were found to lower the threshold for outward currents. Subthreshold ammonia concentrations, just too low to produce reversal alone, produced permanent reversal when assisted by a short flow of very small outward currents, the P.D. remaining reversed when the current was stopped. Further increases of outward current, when the P.D. had been already reversed by ammonia, produced only small further increases of negativity. This shows that the two treatments are of equivalent effect, and mutually assist in producing a given effect, but are not additive in the sense of being superimposable to produce a greater effect than either could produce by itself. Since ammonia increases the alkalinity of the sap, and presumably of the protoplasm, when it penetrates, it is possible that the reversal of P.D. by current flow is also due to change of pH. The evidence for increased alkalinity or acidity due to current flow across phase boundaries or membranes is discussed. While an attractive hypothesis, it meets difficulties in H. ovalis where such pH changes are both theoretically questionable and practically ineffective in reversing the P.D. It seems best at the present time to assign the reversal of P.D. to the alteration or destruction of one surface layer of the protoplasm, with reduction or loss of its potential, leaving that at the other surface still intact and manifesting its oppositely directed potential more or less completely. The location of these surfaces is only conjectural, but some evidence indicates that it is the outer surface which is so altered, and reconstructed on recovery of positive P.D. This agrees with the essentially all-or-none character of the reversal. The various treatments which cause reversal may act in quite different ways upon the surface. PMID- 19872968 TI - THE KINETICS OF SAPONIFICATION OF IODOACETIC ACID BY SODIUM HYDROXIDE AND BY CERTAIN ALKALINE BUFFER SOLUTIONS. AB - 1. The rate of the saponification of iodoacetic acid in sodium hydroxide and alkaline buffer solutions yielding glycollic acid was measured by means of Heyrovsky's polarographic method. 2. From the bimolecular velocity constants, increasing with the ionic strength of the solution, the Bronsted factor, F, which characterizes the primary salt effect, was calculated. 3. In the borate buffer solutions the monomolecular constants of the saponification were determined which, at values above the pH of neutralization of boric acid, show a proportionality to the concentration of hydroxyl anions. Below the pH of neutralization of boric acid, they are proportional to the concentration of borate anions. PMID- 19872969 TI - THE ADSORPTION OF EGG ALBUMIN ON COLLODION MEMBRANES. AB - An experimental study has been made of the adsorption of purified egg albumin, from aqueous solution, on collodion membranes. At protein concentrations of 4 to 7 per cent apparent saturation values were obtained which resembled closely the results obtained with gelatin, showing a maximum at pH 5.0 and lower values on either side of this region. Over large ranges of protein concentration, however, the curves for the adsorption from solutions removed in either direction from the isoelectric point exhibited a different shape from the hyperbola obtained in the neighborhood of pH 5.0. The addition of NaCl to solutions on the acid side tended to obliterate the effect of the pH difference; on the alkaline side it greatly increased the adsorption. The adsorption at 25 degrees was about twice as great as that at 1 degrees . The theory of the swelling of submicroscopic particles, advanced to account for the adsorption behavior of gelatin, is not sufficient to explain the results obtained with egg albumin. It is suggested that the effect is related to alterations in the forces causing the retention of the protein on the membranes. PMID- 19872970 TI - IONIC TRANSFERENCE NUMBERS IN CELLOPHANE MEMBRANES. AB - The "apparent" cation transference number within cellophane is determined for HCl, KCl, NH(4)Cl, NaCl, and LiCl. The method consists in measuring the E.M.F. in a concentration chain employing Ag:AgCl electrodes or calomel electrodes and calculating from formulas derived for cases of simple, unconstrained diffusion. The transference numbers and the cation mobilities relative to the chloride ion were found to be higher in the cellophane (relative cation mobilities increased about 40 per cent). The effect of the membrane is discussed. It is emphasized that with the introduction of a membrane as a liquid junction new factors are introduced, which are not considered in the formulas ordinarily used. Such factors may be activity changes due to dimensional or other reasons and particularly electrical effects exhibited by the membrane upon the ionic diffusion. Accordingly the transference number, as determined, may lack well defined physical significance. PMID- 19872971 TI - CHANGES IN THICKNESS OF THE RED BLOOD CORPUSCLE MEMBRANE. AB - Measurements of the static capacity per cm.(2) of membrane for the red corpuscle as changed when the cells are made spherical by the addition of lecithin or rose bengal, show a slight increase of capacity, indicating a thinning of the membrane, although the change is not large enough to make it certain that it is real. Furthermore, the membrane capacity shows a slight decrease when spherical cells are swollen in hypotonic saline, indicating a thickening of the membrane, although the change is hardly outside the experimental error. The fact that there is no increase in capacity lends support to the theory that as the cell swells the membrane does not stretch but new material comes from the interior of the cell to make a new portion of the membrane. PMID- 19872972 TI - ADAPTATION OF CUTANEOUS TACTILE RECEPTORS : IV. ELECTROLYTE CONTENT OF FROG SKIN. AB - The potassium content of the skin of Rana pipiens is found to be 132 m.g. per cent. This is roughly of the order of magnitude of the content of potassium in nerve. Analyses were also made of the skin for Na, Ca, Mg, Cl, S, and P. PMID- 19872973 TI - ADAPTATION OF CUTANEOUS TACTILE RECEPTORS : V. THE RELEASE OF POTASSIUM FROM FROG SKIN BY MECHANICAL STIMULATION. AB - Potassium is released from the epithelial cells of frog's skin on stimulation by an interrupted air jet. This evidence is consistent with the hypothesis that potassium is involved in the adaptation of the tactile nerve endings in frog's skin. PMID- 19872974 TI - ADAPTATION OF CUTANEOUS TACTILE RECEPTORS : VI. INHIBITORY EFFECTS OF POTASSIUM AND CALCIUM. AB - 1. Both solutions of Ringer plus fifteen times the normal K content, and solutions of Ringer plus fifteen times the normal Ca content markedly hasten the adaptation of single freely branching axon endings in frog's skin to repetitive air puff stimuli. 2. The K effect is produced more rapidly than is that of Ca. The K effect is reversible by washing with Ringer's solution, while the Ca effect is not. The Ca inhibition can, however, be reversed and recovery effected by washing with K rich solutions. 3. Evidence is discussed which indicates that Ca probably plays no role in normal adaptation, and the experiments are interpreted as substantiating the hypothesis of adaptation due to K. PMID- 19872975 TI - ON THE QUANTITY OF ELECTRICITY AND THE ENERGY IN ELECTRICAL STIMULATION. AB - Weiss's and Hoorweg's laws are discussed with respect to the dynamics of the excitatory process. The former is shown to have a simple basis which is inadequate, however, because it implies a constant rate of subsidence of the state of excitation. Hoorweg's law does not follow logically from the same basis so the two laws do not represent the same excitatory mechanism. Experimental data do not give minimal energies at 2 rheobases as predicted by each law. The experimental minima with direct currents are at 1.5 or more rheobases, while with condenser stimuli they are from 2.5 to 3.0 rheobases. These minima conform to the predictions of the writer's equations which give the direct current minima as variable with a lower limit at 1.5 rheobases and the condenser minima as constant at e = 2.718 rheobases. The reasons for these differences are discussed and it is concluded that considerations of the quantity of electricity and the energy, per se, do not lead to any simple concepts with regard to the excitatory mechanism. The existing quantity and energy relations are, however, easily correlated in terms of the dynamics of the excitatory mechanism. PMID- 19872976 TI - INTERMITTENT STIMULATION BY LIGHT : V. THE RELATION BETWEEN INTENSITY AND CRITICAL FREQUENCY FOR DIFFERENT PARTS OF THE SPECTRUM. AB - 1. An optical system is described which furnishes large flickering fields whose brightness, even when reduced with monochromatic filters, is capable of covering the complete range of the relation between critical frequency and intensity. 2. For a centrally located test field of 19 degrees diameter, with light from different parts of the spectrum, the data divide into a low intensity section identified with rod function, and a high intensity section identified with cone function. The transition between the two sections is marked by an inflection point which is sharp, except for 450 and 490 mmicro where, though clearly present, it is somewhat rounded. 3. The intensity range covered by the flicker function is smallest in the red, and increases steadily as the wave-length decreases. The increase is due entirely to the extent of the low intensity, rod section which is smallest (non-existent for S. S.) in the red and largest in the violet. The high intensity cone portion for all colors is in the same position on the intensity axis, and the only effect of decreasing wave-length is to shift the rod section to lower intensities without changing its shape. 4. The measurements are faithfully described by two similar equations, one for the rods and one for the cones, both equations being derived from the general stationary state equation already used for various visual functions. PMID- 19872977 TI - INTERMITTENT STIMULATION BY LIGHT : VI. AREA AND THE RELATION BETWEEN CRITICAL FREQUENCY AND INTENSITY. AB - 1. In the retina, central areas whose diameter is less than 2 degrees possess only cones, while larger areas have rods and cones. In conformity with this, the relation of critical fusion frequency to intensity is a single function for centrally fixated areas below 2 degrees , and a double function for similarly fixated, larger areas. The two sections of such data are easily identified with rod activity at low intensities and with cone activity at high intensities. 2. The curves describing the rod data are the same for all areas, differing only in the values of the associated dimensional constants which control the location of the curves on the coordinate axes. Similarly, the curves for the cone data are the same for all areas; the tendency for an increase in maximal frequency with area is the expression merely of the value of a constant which determines the position of the data on the frequency axis. Area, therefore, does not influence the fundamental nature of the flicker relation through each receptor system, but merely alters the extraneous constants of the relation. 3. The curves which describe the measurements are represented by two equations, one for rods and one for cones; both equations are derived from the stationary state descriptive of the initial event in the photoreceptor process. PMID- 19872978 TI - ISOLATION FROM BEEF PANCREAS OF CRYSTALLINE TRYPSINOGEN, TRYPSIN, A TRYPSIN INHIBITOR, AND AN INHIBITOR-TRYPSIN COMPOUND. AB - Methods are described for the isolation and crystallization of trypsinogen, trypsin, a substance which inhibits trypsin, and an inhibitor-trypsin compound. Analyses and some of the properties of these compounds are given. PMID- 19872979 TI - THE GROWTH AND RESPIRATION OF THE AVENA COLEOPTILE. AB - 1. Transport of the plant growth hormone into the Avena coleoptile as well as the action of the hormone on cell elongation in the coleoptile are shown to depend upon aerobic metabolism. 2. Crystalline auxine, in contrast with impure preparations, affects neither the magnitude nor the respiratory quotient of coleoptile respiration. 3. Increasing age of the coleoptile cell decreases its rate of elongation much more than its rate of respiration. HCN or phenylurethane on the other hand decrease the two processes to the same extent, in spite of the fact that only a small portion of the energy liberated by respiration can be used in the mechanical process of growth. 4. From 2 and 3 it is concluded that processes of a respiratory nature but of relatively small magnitude form one or more integral steps in the chain of reactions by which the plant growth hormone brings about cell elongation. PMID- 19872980 TI - ELECTRIC IMPEDANCE OF INJURED AND SENSITIZED RED BLOOD CORPUSCLES. AB - On the basis of previous work on the electrical properties of hemolyzed red cells, it might be supposed that the variation of the capacity with frequency at low frequencies is an indication of membrane permeability. To test this, rabbit red cells were subjected to treatment with lecithin, tannic acid, glucose, saponin, amboceptor, and colloidal silicic acid, each in sub-lytic doses. No change in any of the electrical properties of any of the suspensions could be detected. The result may mean that the form of the frequency variation is an extremely insensitive measure of permeability and other membrane changes, and capable only of disclosing the very great changes associated with hemolysis, or it may mean that the change in the frequency variation at low frequencies has nothing to do with permeability. PMID- 19872981 TI - ANALYSIS OF THE GEOTROPIC ORIENTATION OF YOUNG RATS. X. AB - The inheritance of elements of geotropic performance in lines of rats (A and B) has been investigated by examining the orientation of young offspring produced in matings of F(1(AxB)) with A: Previous studies had shown that the three recognizable groups of receptor elements concerned in geotropic orientation in each of these lines appeared to be inherited in such a way that B groups were dominant with respect to A groups, although this was to a minor extent complicated by influences affecting the variation of orientation as well as the exact form of the curve relating orientation angle (theta) to slope of surface. In the backcross F(1) x A, therefore, at least eight different types of curves were to be expected. These are in fact identifiable among the forty-one individuals carefully studied. Their classification is concordant with the behavior of the respective indices of variation of theta, for which an interpretation has been provided. The basic result is, therefore, that the three receptor groups of excitation units are inherited independently, and alternatively as regards the members of a homologous pair, and that rather simple dominance relations obtain between homologous groups from the two races, namely that a B effect is dominant over the homologous A effect. This interpretation has been tested in various ways, and is in principle completely consistent with the results of a similar experiment involving races A and K. PMID- 19872982 TI - CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : I. EFFECTS OF GUAIACOL ON VALONIA. AB - In normal cells of Valonia the order of the apparent mobilities of the ions in the non-aqueous protoplasmic surface is K > Cl > Na. After treatment with 0.01 M guaiacol (which does not injure the cell) the order becomes Na > Cl > K. As it does not seem probable that such a reversal could occur with simple ions we may assume provisionally that in the protoplasmic surface we have to do with charged complexes of the type (KX(I))(+), (KX(II))(+), where X(I) and X(II) are elements or radicals, or with chemical compounds formed in the protoplasm. When 0.01 M guaiacol is added to sea water or to 0.6 M NaCl (both at pH 6.4, where the concentration of the guaiacol ion is negligible) the P.D. of the cell changes (after a short latent period) from about 10 mv. negative to about 28 mv. positive and then slowly returns approximately to its original value (Fig. 1, p. 14). This appears to depend chiefly on changes in the apparent mobilities of organic ions in the protoplasm. The protoplasmic surface is capable of so much change that it does not seem probable that it is a monomolecular layer. It does not behave like a collodion nor a protein film since the apparent mobility of Na(+) can increase while that of K(+) is decreasing under the influence of guaiacol. PMID- 19872983 TI - PIGMENTS OF THE RETINA : II. SEA ROBIN, SEA BASS, AND SCUP. AB - 1. Visual purple from the sea robin, sea bass, and scup is almost identical spectroscopically with that from frogs. The interrelations of this pigment with vitamin A and retinene are also the same as in the frog. 2. In strong acids or at pH > 11, the visual yellow of sea robin retinas is converted irreversibly into a pH indicator, yellow in acid and almost colorless in alkaline solution. Unlike neutral visual yellow, the indicator is not removed to form either vitamin A or visual purple. In the ammoniacal retina the reversion of visual yellow itself to purple is accelerated. 3. The combined pigment epithelium and choroid layer in these fishes contain vitamin A, flavine, and an unidentified xanthophyll. PMID- 19872984 TI - THE COLOR VISION OF DICHROMATS : I. WAVELENGTH DISCRIMINATION, BRIGHTNESS DISTRIBUTION, AND COLOR MIXTURE. AB - 1. Protanopes and deuteranopes show one maximum of wavelength discrimination which occurs near their neutral point in the region of 500 mmicro (blue-green for color-normal). The value of the just discriminable wavelength interval Deltalambda is about 1 mmicro at this point and is much like the normal. To either side of this, Deltalambda rises. It increases rapidly on the short-wave side, and slowly on the long-wave side, rising to about 50 mmicro at the two ends of the spectrum. 2. The brightness distribution in the spectrum for dichromats falls only partly outside the range established for color-normals. The protanope curve is narrower than normal, and its maximum lies nearly 15 mmicro to the left of it. The deuteranope curves are about the same width as the normal, and their maxima lie slightly but definitely to the right of it. The main difference between protanope and deuteranope spectrum sensitivity lies on the red side of brightness curves, where the deuteranope is strikingly higher. This difference furnishes the only reliable diagnostic sign which may be applied to an individual dichromat for separating the two types. 3. The average position for the neutral point of twenty-one protanopes is 496.5 mmicro; of twenty-five deuteranopes 504.3 mmicro. The range of variation in the position of neutral point is twice as great for the deuteranope as for the protanope. 4. Dichromatic gauging of the spectrum cannot yield unique mixture values for any wavelength because of the large stretches of poor wavelength discrimination. Data have therefore been secured which locate the spectral ranges that can match specific mixtures of two primaries when brightness differences are eliminated. The form of the data is much the same for a protanope and for a deuteranope; the only difference is in the relative brightness of the primaries. 5. Previously accepted anomalies in the spectral matching of dichromats which have led to the rejection of the third law of color mixture for them, have been eliminated. They are shown to have been due to the non-uniqueness of color matches and the usually disparate brightnesses of the primaries. Color mixture matches for dichromats are valid at all brightnesses. PMID- 19872985 TI - THE COLOR VISION OF DICHROMATS : II. SATURATION AS THE BASIS FOR WAVELENGTH DISCRIMINATION AND COLOR MIXTURE. AB - 1. Wavelength discrimination for the colorblind is entirely determined by saturation differences in the spectrum. From the neutral point to the short-wave end, his spectrum may be completely matched by 440 mmicro plus white; to the long wave end by 650 plus white. The proportion of color to white, hence the relative saturation, changes rapidly in the region of small Deltalambda at the center, and slowly in regions of large Deltalambda at the ends. 2. The data of spectrum gauging with two primaries (color mixture) by the dichromat are shown to contain the saturation distribution in the spectrum for the dichromat. This is because each mixture of primaries may be considered as composed of a mixture which matches white and of an excess of one primary. The data when so computed yield saturation distributions almost identical with those found by direct measurement, and show that on each side of the neutral point the basis of color mixture for the colorblind lies in saturation and not in hue differences. 3. To judge by these measurements, the spectrum for the protanope and deuteranope is composed of only two hues, themselves probably of low saturation, situated one at each end. Toward the center these hues decrease still more in saturation until they completely disappear in the white of the neutral point. PMID- 19872986 TI - STATISTICAL EVALUATION OF SIEVE CONSTANTS IN ULTRAFILTRATION. AB - The partial retention of the disperse phase in the ultrafiltration of a monodisperse system through an isoporous filter is interpreted on a statistical basis, and a simple expression for the sieve constant is evaluated in terms of the calibrated membrane porosity and the particle size. Curves calculated from this expression are in reasonable agreement with experimental data for the ultrafiltration of serum albumin, hemocyanin (Helix), and foot-and-mouth disease virus. PMID- 19872987 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : I. ON THE RELATION BETWEEN MOLECULAR STRUCTURES, CHEMICAL PROPERTIES, AND BIOLOGICAL ACTIVITIES OF THE NITROPHENOLS. PMID- 19872988 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : II. STIMULATION OF CELLULAR OXIDATION AND REVERSIBLE INHIBITION OF CELL DIVISION BY DIHALO AND TRIHALOPHENOLS. AB - The dihalo and trihalophenols, and phenols containing both halo and nitro substituents in the same molecule, produce, in fertilized eggs of Arbacia punctulata, a rise in rate of oxygen consumption and a reversible block to cell division. To define the conditions which affect the degree of this activity, the following factors have been varied: the arrangement of substituents in the molecule, the concentration of reagent, and the time after fertilization at which the reagent is added. The stimulation of oxygen consumption and reversible block to cell division produced by the dihalophenols are qualitatively the same as those previously produced in fertilized Arbacia eggs by certain dinitrophenols. To yield optimum respiratory effect and maximum division block, it usually requires a higher concentration of dihalo than of the corresponding dinitrophenol. For example, with fertilized Arbacia eggs at 20 degrees C. 2,4 dinitrophenol, in optimum concentration of 3 x 10(-5) molar, raises oxygen consumption to 292 per cent of normal (4). The corresponding values for two dihalo analogues are: 2,4-dichlorophenol, 10(-4) molar and 236 per cent; 2,4 dibromophenol, 6 x 10(-5) molar and 282 per cent. The halophenols differ from the nitrophenols in two interesting respects: (a) The monohalophenols produce little or no oxidative stimulation or division block in fertilized Arbacia eggs; p nitrophenol is very active in both respects. (b) The symmetrical trihalophenols have an appreciable ability to stimulate oxygen consumption and block division; symmetrical trinitrophenol is inactive in both respects (4). The increases in oxygen consumption produced in fertilized Arbacia eggs by 2,4-dichloro and 2,4 dinitrophenol are larger than the percentage increases given by methylene blue and o-cresol indophenol under the same experimental conditions. The dihalo and dinitrophenols produce a reversible block to the cell division of fertilized marine eggs. The oxidation-reduction indicators, in contrast to the dihalo and dinitrophenols, block cell division irreversibly and fertilized eggs of Arbacia do not recover from optimum respiratory stimulating concentrations of these oxidation-reduction dyes. The present experiments with halophenols are in harmony with and lend considerable support to the hypothesis (4) that nitro and similarly substituted phenols derive their biological activity from the presence and properties of the phenolic OH group, as modified by proper substitution in the phenolic benzene ring. PMID- 19872989 TI - INTENSITY DISCRIMINATION IN THE HUMAN EYE : I. THE RELATION OFDeltaI/ITO INTENSITY. AB - New measurements of the brightness difference sensibility of the eye corroborate the data of previous workers which show that DeltaI/I decreases as I increases. Contrary to previous report, DeltaI/I does not normally increase again at high intensities, but instead decreases steadily, approaching a finite limiting value, which depends on the area of the test-field and on the brightness of the surrounding field. On a logarithmic plot, the data of DeltaI/I against I for test fields below 2 degrees are continuous, whereas those for test-fields above 2 degrees show a sharp discontinuity in the region of intensity in which DeltaI/I decreases rapidly. This discontinuity is shown to divide the data into predominantly rod function at low intensities, and predominantly cone function at high intensities. Fields below 2 degrees give higher values of DeltaI/I at all intensities, when compared with larger fields. Fields greater than one or two degrees differ from one another principally on the low intensity side of the break. Changes in area above this limit are therefore mainly effective by changing the number of rods concerned. This is confirmed by experiments controlling the relative numbers of rods and cones with lights of different wavelength and with different retinal locations. At high intensities DeltaI/I is extremely sensitive to changes in brightness of surrounding visual fields, except for large test-fields which effectually furnish their own surrounds. This sensitivity is especially marked for fields of less than half a degree in diameter. Although the effect is most conspicuous for high intensities, the surround brightness seems to affect the relation between variables as a whole, except in very small fields where absence of a surround of adequate brightness results in the distortion of the theoretical relation otherwise found. The theoretical relationship for intensity discrimination derived by Hecht is shown to fit practically all of the data. Changes in experimental variables such as retinal image area, wavelength, fixation, and criterion may be described as affecting the numerical quantities of this relationship. PMID- 19872990 TI - ON CRITICAL FREQUENCY AND CRITICAL ILLUMINATION FOR RESPONSE TO FLICKERED LIGHT. AB - The curve of mean critical flicker frequency as a function of illumination has been determined for the reaction of the sunfish Lepomis to flicker. It exhibits expected quantitative disagreements with the curve of mean critical illumination as a function of flicker frequency in the same organism. The form of the dependence of the variation of critical frequency of flicker upon illumination can be predicted from a knowledge of the way in which variation of critical illumination depends upon flicker frequency. It is pointed out that these findings have an important bearing upon the interpretation of the data of intensity discrimination. PMID- 19872991 TI - THE EFFECTS OF CURRENT FLOW ON BIOELECTRIC POTENTIAL : III. NITELLA. AB - String galvanometer records show the effect of current flow upon the bioelectric potential of Nitella cells. Three classes of effects are distinguished. 1. Counter E.M.F'S, due either to static or polarization capacity, probably the latter. These account for the high effective resistance of the cells. They record as symmetrical charge and discharge curves, which are similar for currents passing inward or outward across the protoplasm, and increase in magnitude with increasing current density. The normal positive bioelectric potential may be increased by inward currents some 100 or 200 mv., or to a total of 300 to 400 mv. The regular decrease with outward current flow is much less (40 to 50 mv.) since larger outward currents produce the next characteristic effect. 2. Stimulation. This occurs with outward currents of a density which varies somewhat from cell to cell, but is often between 1 and 2 microa/cm.(2) of cell surface. At this threshold a regular counter E.M.F. starts to develop but passes over with an inflection into a rapid decrease or even disappearance of positive P.D., in a sigmoid curve with a cusp near its apex. If the current is stopped early in the curve regular depolarization occurs, but if continued a little longer beyond the first inflection, stimulation goes on to completion even though the current is then stopped. This is the "action current" or negative variation which is self propagated down the cell. During the most profound depression of P.D. in stimulation, current flow produces little or no counter E.M.F., the resistance of the cell being purely ohmic and very low. Then as the P.D. begins to recover, after a second or two, counter E.M.F. also reappears, both becoming nearly normal in 10 or 15 seconds. The threshold for further stimulation remains enhanced for some time, successively larger current densities being needed to stimulate after each action current. The recovery process is also powerful enough to occur even though the original stimulating outward current continues to flow during the entire negative variation; recovery is slightly slower in this case however. Stimulation may be produced at the break of large inward currents, doubtless by discharge of the enhanced positive P.D. (polarization). 3. Restorative Effects. The flow of inward current during a negative variation somewhat speeds up recovery. This effect is still more strikingly shown in cells exposed to KCl solutions, which may be regarded as causing "permanent stimulation" by inhibiting recovery from a negative variation. Small currents in either direction now produce no counter E.M.F., so that the effective resistance of the cells is very low. With inward currents at a threshold density of some 10 to 20 microa/cm.(2), however, there is a counter E.M.F. produced, which builds up in a sigmoid curve to some 100 to 200 mv. positive P.D. This usually shows a marked cusp and then fluctuates irregularly during current flow, falling off abruptly when the current is stopped. Further increases of current density produce this P.D. more rapidly, while decreased densities again cease to be effective below a certain threshold. The effects in Nitella are compared with those in Valonia and Halicystis, which display many of the same phenomena under proper conditions. It is suggested that the regular counter E.M.F.'S (polarizations) are due to the presence of an intact surface film or other structure offering differential hindrance to ionic passage. Small currents do not affect this structure, but it is possibly altered or destroyed by large outward currents, restored by large inward currents. Mechanisms which might accomplish the destruction and restoration are discussed. These include changes of acidity by differential migration of H ion (membrane "electrolysis"); movement of inorganic ions such as potassium; movement of organic ions, (such as Osterhout's substance R), or the radicals (such as fatty acid) of the surface film itself. Although no decision can be yet made between these, much evidence indicates that inward currents increase acidity in some critical part of the protoplasm, while outward ones decrease acidity. PMID- 19872992 TI - THE EFFECT OF HEMOLYTIC SUBSTANCES ON WHITE CELL RESPIRATION. AB - Substances such as saponin, the bile salts, etc., which produce lysis of red cells also produce cytolysis of white cells from rabbit peritoneal exudates, the arbitrary criterion of their cytolytic effect being their ability to depress the O(2) consumption of the leucocytes. The amount of cytolysis increases regularly as the amount of the added lysin is increased, and sufficiently large quantities of saponin, sodium taurocholate, sodium glycocholate, or sodium oleate are capable of virtually abolishing the O(2) consumption altogether. At the same time, it can be shown that a lysin such as saponin is used up in combining with the white cells in much the same way as it is used up in combining with red cells, and the reduction in oxygen consumption appears to be roughly proportional to the amount so combined. The action of these lytic substances on white cells, in fact, is very similar to their action on red cells, due allowance being made for the fact that the cytolysis of the white cell is probably not an all-or-none process like hemolysis. White cell respiration is also depressed in hypotonic solutions, the respiration being virtually linear with the tonicity. PMID- 19872993 TI - GROWTH SUBSTANCE CURVATURES OF AVENA IN LIGHT AND DARK. AB - An attempt has been made to analyze the base response, one of the light growth responses of Avena coleoptiles, by means of growth substance curvatures. The decrease in growth rate (first part of the base response) after exposure to light does not show if hetero-auxin is substituted for auxin-a (Sections 5, 6, and 10). This decreased growth after exposure very likely is due to an oxidative inactivation of auxin-a (Sections 8 and 9). Hetero-auxin can be inactivated too but in a much lesser degree than auxin-a (Section 9). The increase in growth rate following on the decreased growth (second part of the base response) is due to an increase in response of the plant to growth hormone which is independent of the type of hormone (Sections 1, 2, 7, 8, and 10). Under conditions of continuous exposure to light, however, the inactivation of the auxin-a under influence of the light is superimposed on this increased response to growth hormone. This inactivation can be eliminated from the light growth response by replacing the auxin-a by hetero-auxin. More detailed information on this subject can be found in Section 10. A review of the experiments and their results can be obtained from the scheme in Section 8. In Section 11 it is shown that light inhibits the formation of growth hormone in the decapitated coleoptile (regeneration). Very small amounts of light (25 m.c.s.) inhibit the regeneration markedly. PMID- 19872994 TI - A DESEEDED AVENA TEST METHOD FOR SMALL AMOUNTS OF AUXIN AND AUXIN PRECURSORS. AB - THE MAIN RESULTS PRESENTED IN THIS ARTICLE MAY BE SUMMARIZED AS FOLLOWS: 1. A test method with deseeded Avena seedlings for small concentrations of auxin and precursors of auxin has been described. 2. This method makes possible quantitative determinations of about ten times as low concentrations of hormone as can be obtained with the standard method, (a) Through an increase in the time of the test, so that nearly all the hormone applied can be utilized. (b) Through an increase in sensitivity of deseeded plants to unilaterally applied small concentrations of hormone. 3. The effect of deseeding in relation to curvature growth is primarily the prevention of auxin regeneration through the removal of the material for auxin synthesis, and in addition the prevention of physiological aging. 4. The mechanism of auxin synthesis in the tip of the coleoptile and the mechanism of auxin regeneration in the new physiological tip have been shown to be identical. 5. The application of the deseeded method is illustrated by determinations of auxin in primary leaves and coleoptile sections of Avena seedlings. 6. The deseeded method has been used as a test method for precursors of auxin obtainable from the coleoptile and from other sources. The method further makes possible a distinction between auxins and these substances which may become activated by the plant. 7. Evidence for the existence of a precursor of auxin in the plant is given (a) indirectly by determinations of the decrease in auxin synthesis in deseeded plants. (b) Directly by its isolation from the plant. 8. Precursors of hetero-auxin are demonstrated; their chemical nature and activation are briefly considered. PMID- 19872995 TI - INACTIVATION OF PEPSIN BY IODINE AND THE ISOLATION OF DIIODO-TYROSINE FROM IODINATED PEPSIN. AB - In the presence of iodine at pH 5.0-6.0 a solution of pepsin absorbs iodine and the specific proteolytic activity of the solution decreases. The activity is less than 1 per cent of the original activity when the number of iodine atoms per mol of pepsin is 35-40. If the pH is 4.5 or less, iodine reacts very slowly and there is a correspondingly slower loss in activity. Glycyl tyrosine reacts with iodine in a manner similar to pepsin. Experiments were performed to determine the extent to which oxidation of pepsin by iodine occurs during iodination, and if such oxidation were responsible for the loss in enzymatic activity. Although the results were not absolutely decisive, there seems to be no appreciable oxidation taking place during iodination and no relationship between the slight oxidation and loss in peptic activity. From a dialyzed preparation of completely iodinated pepsin which was inactive and contained 13.4 per cent bound iodine, 82 per cent of the iodine was obtained in a solution which analyzed as a solution of diiodo tyrosine. Because of the presence of a material which contained no iodine and prevented quantitative crystallization, only 53 per cent of the iodine containing substance could be crystallized. This 53 per cent was, however, identified as diiodo-tyrosine. The part of the titration curve which in pepsin and most proteins represents the phenolic group of tyrosine was, in the curve for iodinated pepsin, shifted toward the acid region as expected. From these results, it appears that the loss in proteolytic activity of pepsin, when treated with iodine under the specified conditions, is due to the reaction of the iodine with the tyrosine in pepsin. PMID- 19872996 TI - SEROLOGICAL REACTIONS OF AZOPROTEINS DERIVED FROM AROMATIC HYDROCARBONS AND DIARYL COMPOUNDS. AB - Serological reactions of azoproteins from p-aminodiphenyl, beta-naphthylamine, beta-anthramine and some compounds containing two benzene rings (aminodiphenyl methane etc.) have been described, the last mentioned substances having been the subject of theoretical discussion on serological specificity. PMID- 19872997 TI - CRITICAL ILLUMINATION AND CRITICAL FREQUENCY FOR RESPONSE TO FLICKERED LIGHT, IN DRAGONFLY LARVAE. AB - Curves relating flicker frequency (F) to mean critical illumination (I(m)) for threshold response to flickered light, with equal durations of light and no light intervals, and relating illumination (I) to mean critical flicker frequency (F(m)) for the same response, have been obtained from homogeneous data based upon the reactions of dragonfly larvae (Anax junius). These curves exhibit the properties already described in the case of the fish Lepomis. The curve for F(m) lies above the curve of I(m) by an amount which, as a function of I, can be predicted from a knowledge either of the variation of I(m) or of F(m). The law of the observable connection between F and I is properly expressed as a band, not as a simple curve. The variation of I(m) (and of F(m)) is not due to "experimental error," but is an expression of the variable character of the organism's capacity to exhibit the reaction which is the basis of the measurements. As in other series of measurements, P.E.(I) is a rectilinear function of I(m); P.E.(F) passes through a maximum as F (or I) increases. The form of P.E.(F) as a function of I can be predicted from the measurements of P.E.(I). It is pointed out that the equations which have been proposed for the interpretation of curves of critical flicker frequency as a function of intensity, based upon the balance of light adaptation and dark adaptation, have in fact the character of "population curves;" and that their contained constants do not have the properties requisite for the consistent application of the view that the shape of the F - I curve is governed by the steady state condition of adaptation. These curves can, however, be understood as resulting from the achievement of a certain level of difference between the average effect of a light flash and its average after effect during the dark interval. PMID- 19872998 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : I. ANAX LARVAE. AB - The curve of mean critical illumination (I(m)) for response to flicker as a function of flicker frequency (F) for the larvae of the dragonfly Anax junius is progressively shifted toward higher intensities the lower the temperature. The maximum flicker frequency (one half the cycle time of light and no light) and the maximum intensity with which it is associated are very little if at all affected by change of temperature. These facts are in agreement with the requirements of the conception that recognition of critical illumination for reaction to flicker involves and depends upon a kind of intensity discrimination, namely between the effects of flashes and the after effects of these flashes during the intervals of no light. The shift of the F-I(m) curve with change of temperature is quite inconsistent with the stationary state conception of the determination of the shape of the curve. The dispersion (P.E.(I(I1) )) of the measurements of I(1) is directly proportional to I(m), but the factor of proportionality is less at high and at low temperature than at an intermediate temperature; the scatter of the values of P.E.(I(I1) ) is also a function of the temperature. These facts can also be shown to be concordant with the intensity discrimination basis for marginal recognition of flicker. PMID- 19872999 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : II. SUNFISH. AB - The curve connecting mean critical illumination (I(m)) and flicker frequency (F) for response of the sunfish Lepomis (Enneacanthus gloriosus) to flicker is systematically displaced toward lower intensities by raising the temperature. The rod and cone portions of the curve are affected in a similar way, so that (until maximum F is approached) the shift is a nearly constant fraction of I(m) for a given change of temperature. These relationships are precisely similar to those found in the larvae of the dragonfly Anax. The modifications of the variability functions are also completely analogous. The effects found are consistent with the view that response to flicker is basically a matter of discrimination between effect of flashes of light and their after effects,-a form of intensity discrimination. They are not consistent with the stationary state formulation of the shape of the flicker curve. An examination of the relationships between the cone portion and the rod portion of the curves for the sunfish suggests a basis for their separation, and provides an explanation for certain "anomalous" features of human flicker curves. It is pointed out how tests of this matter will be made. PMID- 19873000 TI - THE POTENTIAL AND RESPIRATION OF FROG SKIN : I. THE EFFECT OF THE HOMOLOGOUS CARBAMATES. II. THE EFFECT OF CERTAIN LYSINS. AB - Measurements of the O(2) consumption and of the potential of frog skin, made under comparable conditions, show that the homologous carbamates (ethyl, propyl, butyl, and amyl) reduce both the O(2) consumption and the potential, but not in a similar manner. In this respect, the effect of the carbamates is like the effect of reduction in O(2) tension. The simple lysins (saponin and the bile salts), on the other hand, abolish the potential without reducing the O(2) consumption at all. Irrespective of whether one considers the concentration of carbamate in the entire system or the amount of carbamate adsorbed by the frog skin, Traube's rule relating the effect of a carbamate to its position in the homologous series does not seem to apply. PMID- 19873001 TI - THE RESPIRATORY QUOTIENT OF SEEDLINGS OF LUPINUS ALBUS DURING THE EARLY STAGES OF GERMINATION. AB - In germinating seedlings of Lupinus albus, the initial respiratory quotient was found to be unity. After a drop to 0.76 at 9 hours, the value rose to 0.90 at 12 hours, and then fell to 0.64 at 60 hours. It is improbable that the fat oxidation system is the first to become activated. PMID- 19873002 TI - COAGULATION OF MYOSIN BY DEHYDRATION. AB - When myosin is dehydrated it becomes insoluble. The number of detectable SH groups in myosin coagulated by dehydration is the same as in native soluble myosin. In this respect coagulation by dehydration differs from coagulation brought about in any of the other ways now known, but resembles the coagulation that occurs in muscle during rigor and in the egg after fertilization. PMID- 19873003 TI - THE COAGULATION OF MYOSIN IN MUSCLE. AB - 1. Muscle can be prepared in the form of a dry powder in which myosin exists in a state similar to that in intact muscle. As in intact muscle, myosin in powdered muscle is soluble and can be caused to rapidly coagulate. 2. Restoring to powdered muscle the quantity of water previously removed causes coagulation of myosin. The rate of coagulation is considerably slower at 0 degrees than at 20 degrees . 3. Adding the powder to a large volume of dilute salt solution also results in coagulation. 4. The water soluble constituents of muscle can be removed from the powder without thereby causing coagulation. Coagulation occurs in water extracted muscle when it is suspended in a dilute salt solution. 5. Coagulation of myosin in muscle resembles the coagulation of myosin caused by dehydration. 6. Myosin coagulates readily only when it is imbedded in the structure of muscle. The significance for coagulation of the arrangement of myosin particles in muscle has been indicated. PMID- 19873004 TI - A PHASE RULE STUDY OF THE PROTEINS OF THE BLOOD SERUM: A COMPARISON OF THE PROTEINS OF HUMAN, RAT, AND HORSE SERUM. AB - There are four different kinds of protein in blood serum as shown by the solubility curves. They must be either single proteins, several continuous series of compounds, or solid solutions. The solid protein phases are hydrated. There are definite sex and species differences. PMID- 19873005 TI - THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS : I. INCREASED HYDROGEN ION CONCENTRATION AND THE INTENSITY OF MUTUAL INDUCTIONS BY NEIGHBORING EGGS OF FUCUS FURCATUS. AB - 1. The eggs of Fucus furcatus develop perfectly in sea water acidified to pH 6.0. They are retarded at pH 5.5. At pH 5.0 they do not develop, nor do they cytolize. 2. In normal sea water in the dark at 15 degrees C., eggs develop rhizoids on the sides in the resultant direction of a mass of neighboring eggs. The polarity and the whole developmental pattern of the embryo is thereby induced. This inductive effect does not operate, however, unless the directing mass is an appreciable aggregation of cells (10 or more), or unless there are numerous other eggs in the dish. A group of five eggs alone in a dish do not carry out mutual inductions. Two eggs alone in a dish do not develop rhizoids toward each other. 3. When the sea water is acidified to pH 6.0 all sizes of aggregations carry out mutual inductions. Two eggs alone in a dish now develop rhizoids on the sides toward each other, provided they are not more than about 4 egg diameters apart. 4. Increased hydrogen ion concentration thus augments or intensifies the mutual inductive effect. 5. This may explain why only larger masses of eggs show inductions in normal sea water, since presumably the larger masses considerably increase the hydrogen ion concentration locally. 6. The nature of the inductive action is discussed. 7. In acidified sea water at pH 6.0, compared with normal sea water at pH 7.8-8.0, the rhizoids originate and extend with a strongly increased downward component. The substrate then forces further extension or growth of the rhizoid to be in the plane of the substrate. PMID- 19873006 TI - SOME REMARKS ON THE PHOTOSYNTHESIS OF GREEN PLANTS. AB - 1. It is suggested that in the assimilation process of green plants the reduction of the CO(2) takes place with the help of Fe(++) ions (present in the chloroplast) under the influence of light, which is absorbed by a sensitizing chlorophyll-CO(2)-complex. 2. It seems that the chlorophyll has to fulfill two different functions depending on its situation in the chloroplast. The chlorophyll molecules on the surface of the lipoid phase (in contact with an aqueous phase containing Fe(++)) combine with CO(2) to form a light absorbing chlorophyll-CO(2)-complex and in this way take part in the reduction of the CO(2). The light energy is also absorbed by the greater portion of the chlorophyll, which is dissolved in the interior of the lipoid phase, and eventually handed over to the chlorophyll molecules on the surface. 3. The photosynthetic unit of Emerson and Arnold may be determined by the ratio: See PDF for Equation so that for every chlorophyll molecule on the surface there are about 500 molecules in the interior, which provide it with the necessary quanta. PMID- 19873007 TI - FLICKER AND THE REACTIONS OF BEES TO FLOWERS. AB - Bees were conditioned to collect food on natural and artificial flower beds, parts of which could be set into rotation or side to side movement. Through the relative motion of the flowers the number of alternating stimuli upon the bee's eye is increased. Due to the fact that bees show a strong reaction to intermittent optical stimulation, the proportion of bees settling on the moving section of the flower bed is increased. It seems probable therefore that the visual reaction of bees to flowers in nature is largely due to the flicker effect produced through the motion of the bees relative to the flowers. PMID- 19873008 TI - THE EFFECT OF ORGANIC IONS ON THE MEMBRANE POTENTIAL OF NERVES. AB - 1. The effect of osmotic pressure on the nerve resting potential of frog sciatic nerve is in accordance with the assumption of a membrane potential; increased osmotic pressure raises, decreased osmotic pressure lowers the potential. 2. The potential of crab nerves is affected by organic and inorganic cations in the approximate series: Rb > K = diamylamine > dibutylamine > guanidine > tetraethylamine > diethylamine = dimethylamine > dipropylamine > tetramethylamine = choline = Na = Li. 3. The response of the potential to the series of dialkylamines (first decrease, then increase of response ascending in the series) is best understood by the assumption that the nerve membrane is a porous structure. 4. With respect to these salts as well as to other organic cations the dried collodion membrane as a model of a porous membrane shows a striking parallelism to the nerve membrane. 5. Both inorganic and organic anions (NO(3), SCN, acetate, propionate, butyrate, lactate, pyruvate) have a definite, if slight, effect in raising the potential of crab nerves. This effect of anions indicates that the nerve membrane is not completely anion impermeable. 6. The effect of organic ions is, with certain restrictions, reversible. Its possible relation to the resting potential and to the after potentials of the electrical disturbance is discussed. 7. The response of the myelinated sciatic nerve of the frog and of the non-myelinated nerve of the spider crab show considerable agreement. There are some definite differences which are, however, not necessarily due to differences of the cell membranes involved, but may be ascribed to the difference of ionic conditions in Ringer and sea water. PMID- 19873009 TI - STUDIES IN BLOOD COAGULATION : V. THE COAGULATION OF BLOOD BY PROTEOLYTIC ENZYMES (TRYPSIN, PAPAIN). AB - Crude or crystalline trypsin in proper concentration causes the blood or plasma of human beings, dogs, rabbits, guinea pigs, and horses to coagulate. It does not clot the fibrinogen directly, but reacts with prothrombin to form thrombin. Since trypsin thus has the same effect as the physiological system Ca plus platelets (or Ca plus tissue extracts), it is suggested as a tentative working hypothesis that the latter system contains a proteolytic enzyme with a specific affinity for prothrombin. Other implications of this trypsin effect with respect to the mechanism of physiological coagulation are discussed in the text (pages 557-558). The proteolytic enzyme papain also coagulates blood. In this case the enzyme does not activate prothrombin, but acts directly on fibrinogen to form a fibrillar gel resembling fibrin. If one admits this clot to be fibrin, this constitutes strong evidence that thrombin, the physiological coagulant, is also a proteolytic enzyme with a specific action on fibrinogen. PMID- 19873010 TI - THE ESTIMATION OF PAPAIN WITH HEMOGLOBIN. PMID- 19873011 TI - THE ESTIMATION OF CATHEPSIN WITH HEMOGLOBIN AND THE PARTIAL PURIFICATION OF CATHEPSIN. PMID- 19873012 TI - THE CALIBRATION OF DIFFUSION MEMBRANES AND THE CALCULATION OF MOLECULAR VOLUMES FROM DIFFUSION COEFFICIENTS. PMID- 19873013 TI - ACTION OF ULTRAVIOLET LIGHT ON SPORES AND VEGETATIVE FORMS OF B. MEGATHERIUM SP. AB - Spores and vegetative forms of a strain of B. megatherium were irradiated by ultraviolet light of the wave lengths 2536 A, 2803 A, and 3132 A. The killing rate of both bacteria and spores is exponential, in agreement with irradiation results on other bacteria. Twice as much incident energy is needed to kill the spores as the vegetative forms (50 per cent death). The absorbed energy per bacterium for 50 per cent killing has been calculated on the assumption that the absorption of the vegetative cells is the same as that of colon bacilli. These results are compared with previous measurements on other bacteria. PMID- 19873014 TI - CONCERNING CRITICAL PERIODS IN THE LIFE OF ADULT DROSOPHILA. AB - Periodic accelerations in the decreasing resistance of adult Drosophila (pure line) to the penetration of alcohol vapor are specifically paralleled by changes in the rate of accumulation of deaths in a life duration experiment with the same line. The necessary interpretation is that there occur under constant conditions periodic fluctuations in the speed of general metabolic events, marking the limits of what may be termed metabolic instars. PMID- 19873015 TI - SUBSTANCES AFFECTING ADULT TISSUE IN VITRO : I. THE STIMULATING ACTION OF TRYPSIN ON FRESH ADULT TISSUE. AB - Adult tissue is characterized by a lag period of several days preceding the onset of growth in vitro. Treatment of fresh adult tissues with trypsin before planting them in culture flasks stimulated the tissues to grow sooner and more rapidly. Best stimulation was obtained by slow digestion at low temperature. The tissues lost nitrogen during the digestion. Lowering the temperature from 22 degrees C. to 5 degrees C. reduced the digestion of aorta tissue much less than it reduced the digestion of casein. Washing the tissue after trypsin treatment resulted in better stimulation. Trypsin solutions of different degrees of purity, when diluted to equal activity toward casein, gave equal stimulation to the tissue growth. These included solutions of Northrop's crystalline trypsin and chymo trypsin. Papain also stimulated growth in a similar manner. The results indicate that this stimulation of tissue growth is due entirely to proteolytic action. Cultures of adult fibroblasts (and some tumor cultures) having reached a state of retarded growth have been treated with trypsin to digest away most of the plasma clot (used as a medium). Fresh plasma has been added to renew the clot. This treatment has resulted in an immediate renewal of growth. Reasons are given for supposing that the cells produce an inhibitor in vitro which they deposit in the surrounding clot, and which is removed by the action of trypsin. PMID- 19873016 TI - SUBSTANCES AFFECTING ADULT TISSUE IN VITRO : II. A GROWTH INHIBITOR IN ADULT TISSUE. AB - Digestion of adult tissue with trypsin has been shown to stimulate its initial growth in vitro. This stimulation appeared to result from the removal of an inhibitory material from the tissue due to the proteolytic action of the trypsin. This paper shows that the fluid after the digestion contains material which inhibits the initial growth of adult chicken aorta tissue. This tissue inhibitor has been obtained from chicken, dog, and sheep aortas. It is partly precipitated by an equal volume of alcohol, and is more completely precipitated by the further addition of CaCl(2) (plus a little NaOH). The inhibitor is destroyed at 100 degrees C. but usually withstands 58 degrees C. for 20 minutes. Moderate tryptic digestion renders it soluble without destroying it. It sometimes withstands dialysis, but at other times is lost. Its physical and chemical properties, as far as we know them, coincide with those of lactenin (a bacteriostatic substance in milk). Lactenin was found to inhibit adult tissue growth; but the tissue inhibitor failed to restrain bacterial growth. This tissue inhibitor is believed to play a role in limiting the growth of tissue in the adult animal. PMID- 19873017 TI - SPECTROSCOPY OF CATALASE. AB - Catalase is resistant to oxidizing agents; e.g., ferricyanide. It is also resistant to reducing agents; e.g., catalytically activated hydrogen, hydrosulfite, ferrotartrate, cysteine. The hemin group of the enzyme will combine with cyanide, sulfides, nitric oxide, fluoride. It will not combine with carbon monoxide. Catalase is therefore a ferric complex. The stability of the ferric iron in the enzyme toward reducing agents is not due to the structure of the porphyrin with which it is combined. This porphyrin is the protoporphyrin of the blood pigment. In combination with globin (methemoglobin) the ferric iron is readily reduced by the same reagents which have no effect on catalase. The stability of the ferric iron in the enzyme is therefore due to the protein component. It may be that the type of hematin-protein linkage in catalase is the reason for this phenomenon. The suggestion of Bersin (31), that sulfur may participate in this linkage, is interesting but, as yet, has no experimental basis. Hydrazine or pyridine and hydrosulfite convert catalase into hemochromogens containing ferrous iron. But in these hemochromogens the hematin is no longer attached to the protein. This has been replaced by the nitrogenous bases hydrazine and pyridine. Both hemochromogens combine reversibly with carbon monoxide. Photo-dissociation has only been demonstrated in the case of the pyridine hemochromogen. The positions of the absorption bands of catalase and its derivatives are listed in Table II. The main absorption band (Soret's band) of hemin complexes with nitrogenous substances (nitrogen bases, proteins) is situated at the border between the visible and the ultraviolet region of the spectrum. It has now been found that the spectrum of purified liver catalase has a well defined maximum of high extinction in this range, at 409 mmicro. This is further evidence for the hemin nature of the enzyme. PMID- 19873018 TI - SUBSTANCES AFFECTING ADULT TISSUE IN VITRO : III. A STIMULANT (THE "A FACTOR") IN SERUM ULTRAFILTRATE INVOLVED IN OVERCOMING ADULT TISSUE DORMANCY. AB - 1. The growth of fresh adult tissue in plasma medium suggested that plasma contained a substance active in overcoming the dormancy of adult tissues. 2. Incubation of adult chicken aorta in serum (from chickens or other species) before it was planted in a plasma medium, resulted in a much shorter lag period and a faster initial growth than that of control tissue incubated in Tyrode solution (or of fresh untreated tissue). In other words, serum helped overcome the dormancy of adult tissue while Tyrode solution preserved the tissue in a dormant state. This activity of serum was shown to be due neither to its albumin or globulin nor to its lipase or other enzymes. 3. The ultrafiltrate from serum was highly active in overcoming adult tissue dormancy, while the dialyzed residue was inactive. The ultrafiltrate was not species specific. It withstood 100 degrees C. in neutral solution for 10 minutes, but not for 3 hours, and was destroyed at pH 2 and pH 12. It was active after 10 months in the ice box. It does not affect tissues in the cold. 4. Copper acetate precipitated a fraction from serum ultrafiltrate which, when freed from copper, was stimulating to the initial growth of adult aorta tissue. 5. Calcium chloride precipitated fractions from serum ultrafiltrate (and also from urine) which were stimulating. 6. Attempts to concentrate the A factor, the active agent, by vacuum evaporation and subsequent fractionation with different solvents were not satisfactory. 7. Lymph was highly stimulating and ventricular fluid slightly stimulating. 8. No growth was obtained in the absence of the A factor, but we doubt that it is alone responsible for overcoming the dormancy of adult tissue. PMID- 19873019 TI - CARBOXYPEPTIDASE : I. THE PREPARATION OF CRYSTALLINE CARBOXYPEPTIDASE. PMID- 19873020 TI - A METHOD FOR THE INVESTIGATION OF ELECTROSTENOLYSIS. AB - A quantitative method for the investigation of electrostenolysis has been developed. Electrostenolysis is redefined in the light of the discovery that organic molecules are subject to it. The experimental requirements for a quantitative study are enumerated, and the apparatus and procedure described. It is found that with ferrous and ferric ions and a cellulose acetate membrane, the potential drop across the membrane must be above about 2150 v./cm. in order to effect any oxidation and reduction. With the present apparatus and conditions the ratio of equivalents oxidized or reduced to faradays passing the membrane is low, of the order of one to several thousand. PMID- 19873021 TI - CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : II. THE ACTION OF GUAIACOL AS AFFECTED BY pH. AB - The normal P.D. across the protoplasm of Valonia macrophysa is about 10 mv. negative (inwardly directed). On adding 0.01 M guaiacol to the sea water the P.D. becomes positive and then slowly returns approximately to the normal value. In many cases this behavior is not much affected by raising the pH and so increasing the concentration of the guaiacol ion but in other cases such an increase makes the P.D. somewhat more negative. But if we wait until the exposure to guaiacol has lasted 5 minutes (and the P.D. has returned to its normal value) before we raise the pH, the result is very different. The cell then behaves as though it had been sensitized to the action of the guaiacol ion which appears to be far more effective than undissociated guaiacol in making the P.D. more positive. This may be due in part to the high apparent mobility of the guaiacol ion and in part to alterations which it produces in the protoplasm (such alterations increase the P.D. across the protoplasm whereas ordinary injury would be expected to lower it and the cells live on after this treatment and show no signs of injury). This action of the guaiacol ion is in marked contrast to the behavior of other anions whose effect resembles that of Cl(-). PMID- 19873022 TI - POLARIZATION STUDIES IN COLLODION MEMBRANES AND IN SYNTHETIC PROTEIN-LIPOID MEMBRANES. AB - 1. Collodion membranes of high polarizability and low resistance can be obtained either by addition of certain ether-soluble substances such as phosphatides, olive oil, mastix, and gum benzoin, to the collodion or by drying collodion membranes for a limited time under pressure. 2. The permeability of membranes of different polarization has been measured by means of conductivity methods. 3. Sintered glass filter plates of Jena glass crucibles on which proteins and lipoids have been adsorbed show polarization. It could be shown that some narcotics which react with lecithin cause an increase in polarization of the protein-lipoid-glass system. Substitutions of the protein but not of the lipoid were possible, without causing a decrease in the polarizability of the membranes. PMID- 19873023 TI - THE QUANTUM YIELD OF HYDROGEN AND CARBON DIOXIDE ASSIMILATION IN PURPLE BACTERIA. AB - 1. The effect of H(2) tension, CO(2) tension, pH, time, light intensity, density of suspension, salt content of the medium, and certain spectral regions on the rate of photoassimilation of H(2) and CO(2) by Streptococcus varians has been studied. 2. The method of making light absorption measurements with thin suspensions of bacteria is described. 3. A light source, optical system, and filter for isolating 852 mmicro with 894 mmicro in sufficient intensity for photochemical work and an improved design of thermostat are given. 4. The photoassimilation of 2H(2) with 1CO(2) apparently involves little over all energy change but nevertheless requires 4 quanta. PMID- 19873024 TI - THE KINETICS OF PENETRATION : XIV. THE PENETRATION OF IODIDE INTO VALONIA. AB - When 0.1 M NaI is added to the sea water surrounding Valonia iodide appears in the sap, presumably entering as NaI, KI, and HI. As the rate of entrance is not affected by changes in the external pH we conclude that the rate of entrance of HI is negligible in comparison with that of NaI, whose concentration is about 10(7) times that of HI (the entrance of KI may be neglected for reasons stated). This is in marked contrast with the behavior of sulfide which enters chiefly as H(2)S. It would seem that permeability to H(2)S is enormously greater than to Na(2)S. Similar considerations apply to CO(2). In this respect the situation differs greatly from that found with iodide. NaI enters because its activity is greater outside than inside so that no energy need be supplied by the cell. The rate of entrance (i.e. the amount of iodide entering the sap in a given time) is proportional to the external concentration of iodide, or to the external product [N(+)](o) [I(-)l(o), after a certain external concentration of iodide has been reached. At lower concentrations the rate is relatively rapid. The reasons for this are discussed. The rate of passage of NaI through protoplasm is about a million times slower than through water. As the protoplasm is mostly water we may suppose that the delay is due chiefly to the non-aqueous protoplasmic surface layers. It would seem that these must be more than one molecule thick to bring this about. There is no great difference between the rate of entrance in the dark and in the light. PMID- 19873025 TI - REACTIONS OF LIMULUS TO ILLUMINATED FIELDS OF DIFFERENT AREA AND FLICKER FREQUENCY. AB - In phototropic tests with young Limulus, the phototropic reactions to flickering fields were studied. If the two fields are equal in area and brightness but different in flicker frequency, the number of animals going to the two fields is proportional to their flicker frequencies. Equal stimulating effects of two fields differing in flicker frequency are obtained by reduction of the area of the faster flickering field. The areas for equal effect must be inversely proportional to their flicker frequencies. It seems that equal effects are dependent upon equality of the number of active excitation elements per unit of time. PMID- 19873026 TI - CARBOXYPEPTIDASE : II. THE PARTIAL PURIFICATION OF PRO-CARBOXYPEPTIDASE. PMID- 19873027 TI - CARBOXYPEPTIDASE : III. THE ESTIMATION OF CARBOXYPEPTIDASE AND PRO CARBOXYPEPTIDASE. PMID- 19873028 TI - THE APPARENT DISTORTION OF BRIEF RECTANGULAR ELECTRICAL STIMULI IN NERVE. AB - If it is assumed that the kinetics of the process of excitation in nerve is given by dp/dt = KI - kp, I being the actual exciting component of the current, p the state of excitation, and K and k constants, it is necessary to postulate that on application of a rectangular stimulus of voltage, V, the current, I, undergoes a transient exponential variation, usually a decrease, in order that the integral of the differential equation (above) may fit the strength-duration data in V and t. This hypothesis is substantiated by data by Sakamoto on single fibers of the sciatic nerve of the frog. The time constant of the postulated current transient is of the order of 10(-4) sec. for single fibers and of the order of 10(-5) sec. or less in the sciatic nerve trunk. The latter value is about the same as that found by Cole in the same tissue by purely physical measurements. Some criticisms by Rushton (1934) are discussed. PMID- 19873029 TI - IMMUNOLOGICAL STUDIES ON PEPSIN AND PEPSINOGEN. AB - 1. Alkali (pH 7.6)-denatured pepsins from swine, cattle, and guinea pigs precipitate in swine pepsin antiserum. Similarly treated pepsins from the rabbit, chicken, and shark do not. 2. Pepsin antisera react with both pepsin and pepsinogen, but do not react with the serum proteins from the homologous species. 3. Pepsinogen antisera react with pepsinogen, but not with twice crystallized pepsin, nor with the serum proteins from the homologous species. Positive reactions between activated pepsinogen and pepsinogen antiserum have been observed. It was possible to remove the reacting material from either the pepsinogen or the activated pepsinogen mixture. 4. Antisera made with serum proteins do not react with the homologous pepsin or pepsinogen. PMID- 19873030 TI - THE INFLUENCE OF LIGHT AND CARBON DIOXIDE ON PHOTOSYNTHESIS. AB - 1. An optical system is described which furnishes an intensity of 282,000 meter candles at the bottom of a Warburg manometric vessel. With such a high intensity available it was possible to measure the rate of photosynthesis of single fronds of Cabomba caroliniana over a large range of intensities and CO(2) concentrations. 2. The data obtained are described with high precision by the equation KI = p/(p(2) (max.) - p(2))((1/2)) where p is the rate of photosynthesis at light intensity I, K is a constant which locates the curve on the I axis, and p(max.) is the asymptotic maximum rate of photosynthesis. With CO(2) concentration substituted for I, this equation describes the data of photosynthesis for Cabomba, as a function of CO(2) concentration. 3. The above equation also describes the data obtained by other investigators for photosynthesis as a function of intensity, and of CO(2) concentration where external diffusion rate is not the limiting factor. This shows that for different species of green plants there is a fundamental similarity in kinetic properties and therefore probably in chemical mechanism. 4. A derivation of the above equation can be made in terms of half-order photochemical and Blackman reactions, with intensity and CO(2) concentration entering as the first power, or if both sides of the equation are squared, the photochemical and Blackman reactions are first order and intensity and CO(2) enter as the square. The presence of fractional exponents or intensity as the square suggests a complex reaction mechanism involving more than one photochemical reaction. This is consistent with the requirement of 4 quanta for the reduction of a CO(2) molecule. PMID- 19873031 TI - THE INFLUENCE OF LIGHT ADAPTATION ON SUBSEQUENT DARK ADAPTATION OF THE EYE. AB - The course of dark adaptation of the human eye varies with the intensity used for the light adaptation which precedes it. Preadaptation to intensities below 200 photons is followed only by rod adaptation, while preadaptation to intensities above 4000 photons is followed first by cone adaptation and then by rod adaptation. With increasing intensities of preadaptation, cone dark adaptation remains essentially the same in form, but covers an increasing range of threshold intensities. At the highest preadaptation the range of the subsequent cone dark adaptation covers more than 3 log units. Rod dark adaptation appears in two types a rapid and a delayed. The rapid rod dark adaptation is evident after preadaptations to low intensities corresponding to those usually associated with rod function. The delayed rod dark adaptation shows up only after preadaptation to intensities which are hundreds of times higher than those which produce the maximal function of the rods in flicker, intensity discrimination, and visual acuity. The delayed form remains essentially constant in shape following different intensities of preadaptation. However, its time of appearance increases with the preadaptation intensity; after the highest preadaptation, it appears only after 12 or 13 minutes in the dark. These two modes of rod dark adaptation are probably the expression of two methods of formation of visual purple in the rods after its bleaching by the preadaptation lights. PMID- 19873032 TI - DO MELANOPHORE NERVES SHOW ANTIDROMIC RESPONSES? AB - 1. In Fundulus heteroclitus the dispersing melanophore nerve fibers have a relatively high threshold for faradic stimulation and a low one for stimulation by cutting. When they are protected from the competing action of the concentrating fibers, they show through the responses of their melanophores well marked antidromic activities which can also be seen to a slight degree even where the concentrating fibers are active. 2. The concentrating melanophore nerve fibers in this fish have a relatively low threshold for faradic stimulation and a high one for stimulation by cutting. They also exhibit clear antidromic responses as shown by their associated melanophores. PMID- 19873033 TI - A PHASE RULE STUDY OF THE PROTEINS OF BLOOD SERUM: THE EFFECT OF CHANGES IN CERTAIN VARIABLES. AB - Changes were studied in the standard solubility curve of fresh serum proteins by alterations in pH, temperature, concentration of protein, and nature of the salt used for precipitation. The principal factor affecting the precipitation of protein fractions was a change in temperature. In order to investigate the proteins in their original states low temperatures are necessary. Protein fraction A is altered by a change in pH and with the use of (NH(4))(2)SO(4) as a precipitant, fraction B by a change in pH and temperature, and use of (NH(4))(2)SO(4), C by a change in temperature and concentration of the protein, and D by a change in temperature and pH. The solubility of D is independent of the amount of protein in solution in high concentrations of salt. PMID- 19873034 TI - THE BIOGENESIS OF PRIMARY SEX HORMONES : I. THE FATE OF ESTRINS INJECTED INTO THE RABBIT. AB - 1. A method is given for the extraction and fractionation of rabbit urines which frees these urines of inactive chromogens but permits a quantitative recovery of estrone and estriol for the colorimetric determination of these compounds. 2. Estrone and estriol content of rabbit urine extracts can be determined by the concentration of the colored compound they form upon diazotization with sulfanilic acid and by the modified phenolsulfonic acid test of Cohen and Marrian. Estriol can be determined by the specific reaction first described by David. The technique for these tests is presented. 3. Estriol (300 micrograms) injected into rabbits (a) in heat, (b) pregnant, (c) pseudopregnant, (d) hysterectomized in heat, (e) hysterectomized pseudopregnant, (f) ovariectomized, is excreted in the urine as estriol. Rabbit does in the luteal phase (b, c, and e) excrete 3 to 4 times the amount of estriol excreted by females without corpora lutea (a, d, and f). 4. When estrone (300 micrograms) is injected into the same types of rabbit does types a, b, and c excrete both estrone and estriol, type f excretes both estrone and estriol shortly after ovariectomy, but only estrone at 2 months after castration. Hysterectomized animals (types d and e) never excrete estriol after estrone injection. The total urinary estrin (estrone plus estriol) in estrone-injected animals is increased 2 to 3 times in animals in the luteal phase (b, c, and e). 5. It is concluded that the uterus is the site of conversion of estrone to estriol, and that the conversion cannot take place in a uterus completely free of ovarian control (e.g., in long time ovariectomized animals). 6. In neither estrone-injected nor estriol-injected females is all the injected hormone recovered in the urine. The maximum recovery is 66 per cent. When estrone benzoate (600 micrograms) is injected 94-98 per cent of the hormone is recovered from animals in the luteal phase (types c and e) and about 79 per cent in an ovariectomized female (type f). These data are taken to indicate that luteal secretions give partial protection against destruction to the hormones. 7. The observation that in certain of the urine extracts the hormone titer by bioassay is somewhat higher than the colorimetric titer may indicate that there is a slight conversion of estrone to estradiol, particularly since no equilenin was found in any of the extracts by colorimetric test. 8. The simultaneous injection of 300 micrograms of estrone and 500 micrograms of progesterone 4 days after an initial injection of 300 micrograms of estrone results in: (1) an increased estrin excretion in females in heat, hysterectomized unmated, and ovariectomized, and a slight decrease in the pseudopregnant female; (2) the appearance of estriol in the urine of the long time ovariectomized animal with no urinary estriol in a control ovariectomized animal receiving no progesterone. These findings are taken to prove that the conversion of estrone to estriol occurs in the uterus under the influence of progesterone. Since animals in heat produce small amounts of estriol after estrone injection it is inferred that the ovaries of estrus rabbits produce small amounts of corpus luteum hormone in the absence of formed corpora lutea. PMID- 19873035 TI - THE EFFECT OF NaCl ON THE PHAGE-BACTERIUM REACTION. AB - 1. The presence of 0.25 M NaCl during the reaction between a staphylococcus phage and susceptible organisms results in a five to tenfold increase in the amount of phage produced. 2. Analysis of the reaction indicates that normal kinetic relationships exist until just before lysis occurs. At this time the organisms enter the stationary phase, lysis is delayed approximately 0.7 hour as compared with control mixtures and phage continues to be produced at the usual rapid rate. 3. Apparently there are conditions under which phage can be produced in the absence of bacterial growth although previous work has uniformly emphasized growth of the bacterial substrate as the prime conditioning factor for formation of phage. PMID- 19873036 TI - STUDIES ON THE DIFFUSION EFFECT UPON IONIC DISTRIBUTION : II. EXPERIMENTS ON IONIC ACCUMULATION. AB - The aim of this paper is to present confirmation of the theory of the diffusion effect. By diffusion effect is understood a redistribution of the ions in a system where a continuous diffusion of one electrolyte is going on, which results in a steady state showing accumulation and impoverishment of certain ions. Some typical experiments are recorded and discussed. The results are found in satisfactory agreement with the theory: this can be demonstrated in several ways. The importance of considering activity changes is pointed out. Water migration and the diffusion membrane probably have no appreciable influence upon the diffusion effect under the conditions of these experiments. The diffusion effect may have biological analogies. PMID- 19873037 TI - CRITICAL ILLUMINATION AND FLICKER FREQUENCY IN RELATED FISHES. AB - Flicker response curves have been obtained at 21.5 degrees C. for three genera of fresh water teleosts: Enneacanthus (sunfish), Xiphophorus (swordtail), Platypoecilius (Platy), by the determination of mean critical intensities for response at fixed flicker frequencies, and for a certain homogeneous group of backcross hybrids of swordtail x Platy (Black Helleri). The curves exhibit marked differences in form and proportions. The same type of analysis is applicable to each, however. A low intensity rod-governed section has added to it a more extensive cone portion. Each part is accurately described by the equation F = F(max.)/(1 + e(-p log(-p logI/I(i) ) )), where F = flicker frequency, I = associated mean critical intensity, and I(i) is the intensity at the inflection point of the sigmoid curve relating F to log I. There is no correlation between quantitative features of the rod and cone portions. Threshold intensities, p, I(i), and F(max.) are separately and independently determined. The hybrid Black Helleri show quantitative agreement with the Xiphophorus parental stock in the values of p for rods and cones, and in the cone F(max.); the rod F(max.) is very similar to that for the Platy stock; the general level of effective intensities is rather like that of the Platy form. This provides, among other things, a new kind of support for the duplicity doctrine. Various races of Platypoecilius maculatus, and P. variatus, give closely agreeing values of I(m) at different flicker frequencies; and two species of sunfish also agree. The effect of cross breeding is thus not a superficial thing. It indicates the possibility of further genetic investigation. The variability of the critical intensity for response to flicker follows the rules previously found to hold for other forms. The variation is the expression of a property of the tested organism. It is shown that, on the assumption of a frequency distribution of receptor element thresholds as a function of log I, with fluctuation in the excitabilities of the marginally excited elements, it is to be expected that the dispersion of critical flicker frequencies in repeated measurements will pass through a maximum as log I is increased, whereas the dispersion of critical intensities will be proportional to I(m); and that the proportionality factor in the case of different organisms bears no relation to the form or position of the respective curves relating mean critical intensity to flicker frequency. These deductions agree with the experimental findings. PMID- 19873038 TI - THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS : II. THE EFFECT OF DIFFUSION GRADIENTS BROUGHT ABOUT BY EGGS IN CAPILLARY TUBES. AB - 1. When a Fucus egg develops near one end in a close fitting capillary tube of pyrex glass or silica (quartz), diffusion of substances passing to and from the egg is more impeded on the side of the egg toward the far end of the tube. 2. The egg therefore develops in a gradient of its own diffusion products, and of oxygen tension. 3. More than 600 eggs have been reared, each near one end in a capillary, in sea water at various regulated and measured pH values. 4. When the medium, which is initially homogeneous inside and outside the capillary, is initially at pH 6.5 to 7.6, nearly all of the eggs develop rhizoid protuberances on the sides of the eggs toward the far ends of the capillaries. This is on the sides of the eggs where the concentration of substances diffusing from the eggs is greatest. 5. The polarity and developmental pattern of the egg is thus determined either by a concentration gradient of products diffusing from it, or by a gradient of oxygen tension. The former interpretation is favored. 6. This is regarded as an extension of earlier observations that rhizoid protuberances form on the sides of two neighboring eggs in the direction of the neighbor if the sea water is acidified. 7. It appears hardly possible that a mitogenetic effect could be responsible for the response of an egg to its own diffusion gradients. 8. When the medium is made more basic, the percentage of the eggs which form rhizoid protuberances toward the far end of the tube decreases to about 20 or 25 per cent between pH 8.1 and 8.6. The response of the egg to the gradients which it produces is thus statistically reversed. The determination of the polarity of the eggs by the diffusion gradients does not become as complete in alkalinized as in acidified sea water. 9. When the pH of the sea water is elevated to 9.1 or 9.2, salts precipitate out. The type of development is altered and the control of the diffusion gradients over the polarity of the eggs decreases. PMID- 19873039 TI - THE RATE OF CO(2) ASSIMILATION BY PURPLE BACTERIA AT VARIOUS WAVE LENGTHS OF LIGHT. AB - 1. The relative absorption spectrum of the pigments in their natural state in the photosynthetic bacterium Spirillum rubrum is given from 400 to 900 mmicro. The position of the absorption maxima in the live bacteria due to each of the pigments is: green pigment, 420, 590, 880; red pigment, 490, 510, 550. 2. The relative absorption spectrum of the green pigment in methyl alcohol has been determined from 400 to 900 mmicro. Bands at 410, 605, and 770 mmicro were found. 3. The wave length sensitivity curve of the photosynthetic mechanism has been determined and shows maxima at 590 and about 900 mmicro. 4. It is concluded that the green bacteriochlorophyll alone and not the red pigment can act as a light absorber for photochemical CO(2) reduction. PMID- 19873040 TI - EXCITATION THEORIES OF RASHEVSKY AND HILL. PMID- 19873041 TI - VISUAL ADAPTATION AND CHEMISTRY OF THE RODS. AB - 1. The reality of a chemical cycle proposed to describe the rhodopsin system is tested with dark adaptation measurements. 2. The first few minutes of rod dark adaptation are rapid following short, slower following long irradiation. As dark adaptation proceeds, the slow process grows more prominent, and occupies completely the final stages of adaptation. 3. Light adaptation displays similar duality. As the exposure to light of constant intensity lengthens, the visual threshold rises, and independently the speed of dark adaptation decreases. 4. These results conform with predictions from the chemical equations. PMID- 19873042 TI - THE EFFECT OF AUXINS UPON PROTOPLASMIC STREAMING. AB - 1. Evidence has accumulated that the action of auxins in promoting growth is exerted not upon the cell wall but upon the cell contents; i.e., the protoplasm. Following indications previously obtained, therefore, the effect of auxins on the rate of protoplasm streaming in the Avena coleoptile was studied. 2. Indole-3 acetic acid, the most active auxin available in pure form, was found to increase the rate of streaming in the epidermal cells of the Avena coleoptile at concentrations between 0.5 and 0.002 mg. per liter, the maximum increase being brought about at 0.01 mg. per liter. This concentration is approximately that which, applied in agar to one side of the decapitated coleoptile, would give a curvature of 1 degrees ; i.e., it is well within the range of concentrations active in growth promotion. It is, however, much less than that which produces maximum elongation in immersed sections of Avena coleoptiles. 3. This accelerating effect is readily determined quantitatively by comparison with the streaming in control coleoptiles in pure water, which, if thoroughly aerated, maintain a constant rate for over an hour. The accelerating effect takes place immediately and is over within about 30 minutes. 4. Concentrations of indole-3 acetic acid greater than 0.5 mg.per liter inhibit the streaming, the effect being also over in about 30 minutes, and its extent increasing with increasing auxin concentration. This parallels the effect of high auxin concentrations in inhibiting elongation, although the inhibition of streaming is obtained at much lower concentrations than inhibit elongation. 5. The effects of indole-3-acetic acid on streaming are not specific for that substance, but appear to be common to auxins in general. Thus coumaryl-3-acetic acid and allocinnamic acid, both of which bring about cell enlargement, root formation, and bud inhibition, i.e. are typical auxins, also cause an immediate acceleration of the rate of streaming, and as with indole-acetic add the effect is over in about 30 minutes. The concentrations of these two substances which produce the maximum effect are about ten times that of indole-acetic acid, which approximately corresponds with their relative auxin activities. The curves relating concentrations of these substances to their effects on streaming are very similar to that for indole-acetic acid. 6. On the other hand, certain substances which are known to affect streaming in other materials do not produce any effect comparable to that of auxin. Ethylene chlorhydrin, histidine, and urea in all concentrations were without effect on streaming in the Avena coleoptile within the first 30 minutes of treatment. 7. The effects produced by the auxins were not due to pH. 8. The action on streaming here studied is evidently quite different from the re-starting of streaming after its cessation, studied by Fitting in Vallisneria. Correspondingly histidine, which in Fitting's experiments showed activity down to 10(-7)M, is inactive here. 9. Per contra, the effect of auxin here studied is on normal streaming. It takes place immediately and at concentrations in the same range as those which produce growth. The curve of effect against concentration parallels that for growth although the actual concentration values differ. It is therefore reasonable to suppose that the effect of auxin on streaming is closely connected with one of the first stages of its effect on the growth process. PMID- 19873043 TI - THE RELATIONSHIP BETWEEN BACTERIAL GROWTH AND PHAGE PRODUCTION. AB - 1. The effects of temperature and H-ion concentration on the reaction between antistaphylococcus phage and a susceptible staphylococcus have been studied. 2. The temperature optimum for phage production is in the neighborhood of 35 degrees C. and that for bacterial growth is approximately 40 degrees C. 3. With increasing H-ion concentrations there occur: (a) an increase in the lag phase of bacterial growth without any corresponding increase in the lag phase of phage production; (b) a diminution in the total bacterial population accumulating in the medium without any corresponding drop in the total amount of phage formed. 4. With increasing alkalinity there is no pronounced change in the curves of bacterial growth and phage formation. At pH 8.5 the lytic threshold is increased to about 1000 phage units per bacterium instead of 100-140 as is usually the case and the time of lysis is delayed. 5. By adjusting the medium to pH 6 and 28 degrees C. bacterial growth can be completely inhibited while phage production continues at a rapid rate. 6. Apparently, the previously stressed importance of bacterial growth as the prime conditioning factor for phage formation does not hold, for under certain experimental conditions the two mechanisms can be dissociated. PMID- 19873044 TI - THE INDUCTION PERIOD IN PHOTOSYNTHESIS. AB - 1. Measurements on the photosynthesis of Cabomba caroliniana show an induction period at low and high light intensities and CO(2) concentrations. 2. The equation which describes the data for Cabomba also describes the data obtained by other investigators on different species. The phenomenon is thus shown to be similar in plants representative of three phyla. 3. A derivation of the induction period equation is made from a consideration of the cycle of light and dark processes known to occur in photosynthesis. The equation indicates that light intensity enters as the square, and that the same light reactions are involved as those which affect the stationary state rates. However, a different dark reaction appears to limit photosynthesis during the induction period. PMID- 19873045 TI - THE RELATION BETWEEN VISUAL ACUITY AND ILLUMINATION. AB - 1. An apparatus for measuring the visual acuity of the eye at different illuminations is described. The test object is continuously variable in size and is presented at a fixed distance from the eye in the center of a 30 degrees field. Observation of the field is through an artificial pupil. The maximum intensity obtainable is more than enough to cover the complete physiological range for the eye with white light though only 110 watts are consumed by the source. Means for varying the intensity over a range of 1:10(10) in small steps are provided. 2. The relation of visual acuity and illumination for two trained observers was measured, using two different types of test object, a broken circle and a grating. The measurements with both test objects show a break at a visual acuity of 0.16, all values below that being mediated by the rods and those above by the cones. The grating gives higher visual acuities at intensities less than about 30 photons and lower visual acuities above that. The maximum visual acuity attainable with the grating under the same conditions is about 30 per cent lower than that with the C. It is shown that the limiting factor in the resolution of the eye for the grating is the diameter of the pupil when it is less than 2.3 mm. and the size of the central cones when the pupil is larger than that. The value of the diameter of the cone derived on that basis from the visual acuity data agrees with that derived from direct cone count in a unit of area. 3. The data for the cones made with both test objects are adequately described by one and the same form of the stationary state equation derived by Hecht for the photoreceptor system. This fact, together with certain considerations about the difference in the nature of the two test objects with regard to the resolvable area, leads to the conclusion that detail perception is a function of a distance rather than an area. All the data for the rods can likewise be described by another variety of the same equation, although the data are too fragmentary to make the choice of the form as certain as might be desired. PMID- 19873046 TI - TRANSVERSE ELECTRIC IMPEDANCE OF NITELLA. AB - Alternating current measurements have been taken on single Nitella cells over a frequency range from 30 to 2,500,000 cycles per second with the current flow perpendicular to the axis of the cell. The measuring cells were so constructed that electrolytes of any desired concentration could be circulated during the course of the measurements. The cellulose wall which surrounds the cell is found to play an important part in the interpretation of the results obtained. In a mature cell, this cellulose has a specific resistance of about 1000 ohm cm. which is independent of the medium in which the cell is suspended. The thickness of the wall is computed to be about 10 micro. The cell membrane is found to be virtually non-conducting, and to have a capacity of 0.94 microf./cm.(2) +/- 10 per cent and a phase angle of 80 degrees +/- 4 degrees . The specific resistances of the sap were difficult to compute from data on living cells and were unsatisfactory because they were very much dependent upon the medium, while measurements on extracted sap gave 58 ohm cm. +/- 8 per cent which was independent of the medium. There are indications that the chloroplasts have impedance properties similar to those of living cells. PMID- 19873047 TI - INTENSITY AND CRITICAL FREQUENCY FOR VISUAL FLICKER. AB - Using the rotating striped cylinder device previously employed for determination of the flicker response function with lower animals, corresponding measurements have been made with human observers. The curves based upon the relation between critical flash frequency and critical intensity for the signalling of the recognition of flicker have the properties of human flicker fusion data as obtained by other methods. They also have the quantitative properties of the flicker curves provided by the motor responses of insects and fishes to the seen movement of flashes. This applies to the variation found in repeated measurements as well as to the nature of the analytical function describing the connection between flash frequency and intensity. The data for human visual flicker and those for the responses of lower animals are therefore essentially homologous. PMID- 19873048 TI - CRITICAL ILLUMINATION FOR RESPONSE TO FLICKERED LIGHT, WITH DRAGONFLY LARVAE (ANAX), IN RELATION TO AREA OF EYE. AB - Arthropods with large convex eyes provide curves of critical illumination for response as a function of flicker frequency (or of visual acuity) which depart from the probability integral type characteristically found for F - log I with vertebrates. By means of experiments with Anax nymphs in which various parts of the eye have been opaqued it is shown that the special shape of the flicker curve is due to the mechanical disadvantage of the periphery of the eye in the reception of light, which is overcome by higher intensities. It is not due to a fixed spatial pattern of intrinsic individual excitabilities of the ommatidia. Reduction of retinal area decreases F(max.), and increases log I for F/F(max.) = 50 per cent. The direct proportionality of I(m) to P.E.(1I) is independent of area. Certain relations of these facts to the theory of response to flicker have been discussed. PMID- 19873049 TI - A PHASE RULE STUDY OF THE PROTEINS OF BLOOD SERUM : III. GLOBULIN. AB - A method has been developed for applying the phase rule to systems of several protein components in serum. The globulin fractions which have been investigated appear to be homogeneous substances. PMID- 19873050 TI - AREA AND VISUAL THRESHOLD. AB - 1. The variation of threshold with field area was measured in fields homogeneous in rod-cone composition. At 15 degrees above the fovea, an increase in field diameter from 1 degrees to 5 degrees reduces the threshold sevenfold, at 25 degrees above the fovea tenfold. 2. These changes are shown to follow qualitatively from simple statistical properties of the retinal mosaic. Analytic treatment leads to the expression, (A - n(t))(k) I = C, in which A = area, n(t) = constant threshold number of elements, I = threshold intensity, and k and C are constants. This equation describes the available data accurately, and is the general form of previous empirical area-threshold formulae. PMID- 19873051 TI - STUDIES ON ENZYMATIC HISTOCHEMISTRY : XXV. A MICRO METHOD FOR THE DETERMINATION OF CHOLINE ESTERASE AND THE ACTIVITY-PH RELATIONSHIP OF THIS ENZYME. AB - The activity-pH relationship for choline esterase from horse serum, gastric mucosa of the pig, and cat brain was investigated, and an optimum was observed at pH 8.5 in each case. A micro method for the determination of choline esterase was developed capable of measuring the hydrolysis down to the order of that given by 1 x 10(-8) mol of ester. PMID- 19873052 TI - STUDIES ON ENZYMATIC HISTOCHEMISTRY : XXVI. THE HISTOLOGICAL DISTRIBUTION OF CHOLINE ESTERASE IN THE GASTRIC MUCOSA NORMALLY AND AFTER ADMINISTRATION OF CERTAIN DRUGS. AB - Extraction experiments demonstrated that choline esterase could be removed from microtome sections of tissue with as great facility by 0.9 per cent NaCl as by 30 per cent glycerol. The quantitative distribution of choline esterase through the wall of the pig stomach was studied, and it was found that the epithelial cell region possessed the greatest activity and muscle tissue the least. Pylorus was more active than fundus or cardia. The enzyme activities found were independent of the physiological state of the normal stomach at the time the animal was killed. Neither intramuscular injection of acetyl choline, eserine, nor atropine shortly before killing had significant influence upon the activity in any region of the stomach. The implications of these results were discussed. PMID- 19873053 TI - CRITICAL ILLUMINATION AND FLICKER FREQUENCY, AS A FUNCTION OF FLASH DURATION: FOR THE SUNFISH. AB - From the relations between critical illumination in a flash (I(m)) and the flash frequency (F) for response of the sunfish to visual flicker when the proportion of light time to dark time (t(L)/t(D)) in a flicker cycle is varied at one temperature (21.5 degrees ) the following results are obtained: At values of t(L)/t(D) between 1/9 and 9/1 the F - log I(m) curves are progressively shifted toward higher intensities and lower F(max.). F(max.) is a declining rectilinear function of the percentage of the flash cycle time occupied by light. The rod and the cone portions of the flicker curve are not shifted to the same extent. The cone portion and the rod region of the curve are each well described by a probability integral. In terms of F as 100 F/F(max.) the standard deviation of the underlying frequency distribution of elemental contributions, summed to produce the effect proportional to F, is independent of t(L)/t(D). The magnitude of log I(m) at the inflection point (r'), however, increases rectilinearly with the percentage light time in the cycle. The proportionality between I(m) and sigma(I(I1) ) is independent of t(L)/t(D). These effects are interpreted as consequences of the fact that the number of elements of excitation available for discrimination of flicker is increased by increasing the dark interval in a flash cycle. Decreasing the dark interval has therefore the same kind of effect as reducing the visual area, and not that produced by decreasing the temperature. PMID- 19873054 TI - CONCENTRATION AND PURIFICATION OF BACTERIOPHAGE. AB - 1. A method for isolating a nucleoprotein from lysed staphylococci culture is described. 2. It is homogeneous in the ultracentrifuge and has a sedimentation constant of 650 x 10(-13) cm. dyne(-1) sec.(-1), corresponding to a molecular weight of about 300,000,000. 3. The diffusion coefficient varies from about 0.001 cm.(2)/day in solutions containing more than 0.1 mg. protein/ml. to 0.02 in solutions containing less than 0.001 mg. protein/ml. The rate of sedimentation also decreases as the concentration decreases. It is suggested, therefore, that this protein exists in various sized molecules of from 500,000-300,000,000 molecular weight, the proportion of small molecules increasing as the concentration decreases. 4. This protein is very unstable and is denatured by acidity greater than pH 5.0, by temperature over 50 degrees C. for 5 minutes. It is digested by chymo-trypsin but not by trypsin. 5. The loss in activity by heat, acid, and chymo-trypsin digestion is roughly proportional to the amount of denatured protein formed under these conditions. 6. The rate of diffusion of the protein is the same as that of the active agent. 7. The rate of sedimentation of the protein is the same as that of the active agent. 8. The loss in activity when susceptible living or dead bacteria are added to a solution of the protein is proportional to the loss in protein from the solution. Non-susceptible bacteria remove neither protein nor activity. 9. The relative ultraviolet light absorption, as determined directly, agrees with that calculated from Gates' inactivation experiments in the range of 2500-3000 A. u. but is somewhat greater in the range of 2000-2500 A. u. 10. Solubility determinations showed that most of the preparations contained at least two proteins, one being probably the denatured form of the other. Two preparations were obtained, however, which had about twice the specific activity of the earlier ones and which gave a solubility curve approximating that of a pure substance. 11. It is suggested that the formation of phage may be more simply explained by analogy with the autocatalytic formation of pepsin and trypsin than by analogy with the far more complicated system of living organisms. PMID- 19873055 TI - AN ULTRACENTRIFUGAL ANALYSIS OF CONCENTRATED STAPHYLOCOCCUS BACTERIOPHAGE PREPARATIONS. AB - Analytical observations have been made with the air ultracentrifuge on concentrated staphylococcus bacteriophage solutions and on these solutions inactivated by alkali, chymo-trypsin, and heat. All active solutions contain a homogeneous heavy component that sediments with a constant of s(20 degrees ) = ca. 650 x 10(-13) cm. sec.(-1) dynes(-1), has an apparent density of ca. 1.20, and a molecular weight probably not less than 200 millions. There is also present some very light ultraviolet-absorbing material which is not a carrier of bacteriophage activity. The amount of the heavy component is not strictly proportional to the bacteriophage activity so that if the activity resides in it, as appears to be the case, inactivation may occur without measurable change in molecular size and shape. When the bacteriophage solutions are inactivated by chymo-trypsin, the heavy component is not disrupted but the sedimenting boundaries have always been fairly diffuse. As the activity gradually disappears from alkaline solutions, the heavy component is replaced by unsedimentable material. When a solution is inactivated by heating, a dilute gel is produced which sediments with an exceptionally sharp boundary in a relatively intense centrifugal field. PMID- 19873056 TI - DARK ADAPTATION IN DINEUTES. AB - The level of dark adaptation of the whirligig beetle can be measured in terms of the threshold intensity calling forth a response. The course of dark adaptation was determined at levels of light adaptation of 6.5, 91.6, and 6100 foot-candles. All data can be fitted by the same curve. This indicates that dark adaptation follows parts of the same course irrespective of the level of light adaptation. The intensity of the adapting light determines the level at which dark adaptation will begin. The relation between log aI(0) (instantaneous threshold) and log of adapting light intensity is linear over the range studied. PMID- 19873057 TI - THE CONCENTRATION EFFECT WITH VALONIA: POTENTIAL DIFFERENCES WITH DILUTED POTASSIUM-RICH SEA WATERS. AB - The concentration effect with sea waters containing more than the normal amount of potassium has been studied in Valonia macrophysa. This was done by comparing the initial changes in P.D. across the protoplasm when natural sea water bathing the cell was replaced by various isotonic dilutions of KCl-rich sea waters. With small dilutions of KCl-rich sea waters, the P.D.-time curves are of the same form as with the undiluted solution, exhibiting the fluctuations characteristic of KCl rich solutions. This indicates that with these solutions K(+) enters Valonia protoplasm and plays an important part in the P.D. The value of the initial rise in P.D. decreases with increasing dilution. With high dilutions of KCl-rich sea waters, the P.D.-time curves are of quite different shape, resembling the curves with diluted natural sea water; the P.D. is practically independent of small changes in the concentration of potassium, and increases with increasing dilution. That is, with these higher dilutions, the sign of the concentration effect is reversed, becoming the same as with diluted natural sea water. The greater the concentration of KCl in the undiluted sea water, the higher is the critical dilution at which K(+) ceases to influence the P.D. For a wide range of sea waters containing both KCl and NaCl, it is shown that the concentration effect above the critical dilution is determined solely by the activity of NaCl in the external solution. It is concluded that with dilute natural sea water and with high dilutions of KCl-rich sea waters we have to do with a diffusion potential, involving only the Na(+) and Cl(-) ions, which are diffusing out from the vacuole. A quantitative relation between the composition of the sea water and the critical dilution has been deduced from the classical theory of the diffusion of electrolytes. It is shown that with dilutions less than this critical value the diffusion of K(+) in the outer non-aqueous layer of the protoplasm is directed inward; hence K(+) enters the protoplasm from these solutions. With dilutions greater than the critical value, the diffusion of K(+) in this layer is directed outward; hence K(+) does not enter the protoplasm. Since the P.D. shows no evidence of this outward diffusion of K(+), it is concluded that the amount of K(+) ordinarily present in the protoplasm is too small to produce any lasting electrical effect, and that the outward diffusion of K(+) from the vacuole is prevented by the mechanism responsible for the accumulation of KCl in the cell sap. PMID- 19873058 TI - THE ABSORPTION SPECTRUM OF VISUAL PURPLE. AB - The absorption spectra of visual purple solutions extracted by various means were measured with a sensitive photoelectric spectrophotometer and compared with the classical visual purple absorption spectrum. Hardening the retinas in alum before extraction yielded visual purple solutions of much higher light transmission in the blue and violet, probably because of the removal of light-dispersing substances. Re-extraction indicated that visual purple is more soluble in the extractive than are the other colored retinal components. However, the concentration of the extractive did not affect the color purity of the extraction but did influence the keeping power. This suggests a chemical combination between the extractive and visual purple. The pH of the extractive affected the color purity of the resulting solution. Over the pH range from 5.5 to 10.0, the visual purple color purity was greatest at the low pH. Temperature during extraction was also effective, the color purity being greater the higher the temperature, up to 40 degrees C. Drying and subsequent re-dissolving of visual purple solutions extracted with digitalin freed the solution of some protein impurities and increased its keeping power. Dialysis against distilled water seemed to precipitate visual purple from solution irreversibly. None of the treatments described improved the symmetry of the unbleached visual purple absorption spectrum sufficiently for it to resemble the classical absorption spectrum. Therefore it is very likely that the classical absorption spectrum is that of the light-sensitive group only and that the absorption spectra of our purest unbleached visual purple solutions represent the molecule as a whole. PMID- 19873059 TI - CHOLINE ESTERASE AND THE THEORY OF CHEMICAL MEDIATION OF NERVE IMPULSES. AB - The maximum choline esterase activity of the superior cervical ganglion of the cat was measured and found to be, on the average, equivalent to the splitting of 0.10gamma of acetyl choline chloride per second per milligram of fresh tissue at a pH of 7.4 and 38 degrees . The least possible time required for destruction of the ester liberated by one nerve impulse was calculated to be 0.015sigma. The dissociation constant of the reaction between the enzyme and acetyl choline chloride was determined, and a value of 0.001 was obtained. From the value of the dissociation constant, the time for hydrolysis at the minimum rate was calculated to be about 8 seconds. It was shown that a localization of enzyme and substrate within the ganglion cell would have to exist in order that enzymatic destruction of acetyl choline liberated by nerve impulses occur within the span of the refractory period. PMID- 19873060 TI - THE EFFECT OF AUXINS ON PROTOPLASMIC STREAMING. II. AB - 1. A further study has been made of the effect of indole-3-acetic acid (auxin) on protoplasmic streaming in the epidermal cells of the Avena coleoptile. 2. The transient nature of the effect of auxin, both in accelerating and retarding streaming, is due to the temporary exhaustion of carbohydrate from the tissues. In presence of 1 per cent fructose or some other sugars the acceleration or retardation of streaming by auxin is not transient, but is maintained for at least 2 hours. 3. The retardation of streaming brought about by concentrations of auxin above 0.5 mg. per liter is due to oxygen deficiency This has been confirmed in several ways. 4. It follows that the effect of auxin is to increase the respiration of the coleoptile tissue. 5. Younger coleoptiles, 3 cm. long, are sensitive to lower concentrations of auxin than those 5 cm. long, and more readily exhibit oxygen deficiency as a result of the action of auxin. However, after decapitation their response to auxin more closely resembles that of 5 cm. coleoptiles. 6. The retardation of streaming in such coleoptiles, resulting from oxygen deficiency, is delayed by very dilute solutions of histidine. On this basis an explanation is suggested for the results of Fitting on streaming in Vallisneria leaves. 7. The mean rate of streaming in control untreated coleoptiles in pure water varies with the time of year, but not with the time of day. 8. The results support the view that auxin accelerates an oxygen-consuming process which controls the rate of protoplasmic streaming, and that the latter controls growth. The substrate for this process is probably sugar. 9. It is suggested that auxin also accelerates another oxygen-consuming process, which may withdraw oxygen from the process which controls streaming rate and hence cause retardation of the latter. PMID- 19873061 TI - CRITICAL INTENSITY AND FLASH DURATION FOR RESPONSE TO FLICKER: WITH ANAX LARVAE. AB - Determinations of the flicker response curve (F - log I(m)) with larvae of Anax junius (dragonfly) for various ratios t(L)/t(D) of light time to dark time in a flash cycle provide relations between t(L)/t(D) and the parameters of the probability integral fundamentally describing the F - log I function, including the variability of I. These relations are quantitatively of the same form as those found for this function in the sunfish, and are therefore non-specific. Their meaning for the theory of reaction to visual flicker is discussed. The asymmetry of the Anax curve, resulting from mechanical conditions affecting the reception of light by the arthropod eye, is (as predicted) reduced by relative lengthening of the fractional light time in a cycle. PMID- 19873062 TI - THE KINETICS OF EXCYSTMENT IN COLPODA DUODENARIA. AB - 1. Extensive experimental data have been collected on the time required for the excystment process of the small ciliate Colpoda duodenaria throughout a range of temperatures of 8 degrees through 32 degrees C. and a range of concentrations of yeast extract excystment media of 0.08 through 22.4 gm./liter. 2. The excystment process has been separated into two periods, the first inversely proportional to the concentration of the yeast extract and the second independent of its concentration. 3. The first excystment period has been found to depend on the time for diffusion through the protoplasm of a compound from the yeast extract and on the time for a chemical reaction with the extremely high energy of activation of 220,000 calories/mole. 4. The changes in viscosity with temperature for this Colpoda, inferred from diffusion rate changes, have been found to be almost the same as those found by Heilbrunn for Amoeba dubia by the direct method of centrifuging granules. 5. The second excystment period is shown to be controlled by reactions whose apparent activation energies are 44,000 calories/mole below 15 degrees C. and 18,000 calories/mole above 15 degrees C.; above 25 degrees C. this period is independent of temperature. 6. The distribution of the log excystment times of individual organisms about the mean log excystment time is found to be independent of temperature except in the range where the reaction with highest activation energy takes a significant length of time, and to increase rapidly with decreasing temperatures in this range. PMID- 19873063 TI - ISOLATION, CRYSTALLIZATION, AND PROPERTIES OF SWINE PEPSINOGEN. AB - 1. A method is described for the preparation of pepsinogen from swine gastric mucosae which consists of extraction and fractional precipitation with ammonium sulfate solutions followed by two precipitations with a copper hydroxide reagent under particular conditions. Crystallization as very thin needles takes place at 10 degrees C., pH 5.0 and from 0.4 saturated ammonium sulfate solution containing 3-5 mg. protein nitrogen per milliliter. 2. Solubility measurements, fractional recrystallization, and fractionation experiments based on separation after partial heat or alkali denaturation and after partial reversal of heat or alkali denaturation failed to reveal the presence of any protein impurity. 3. The properties of the enzymatically inactive pepsinogen were studied and compared with the properties of crystalline pepsin. The properties of pepsinogen which are similar to those of pepsin are: molecular weight, absorption spectrum, tyrosine tryptophane content, and elementary analysis. The properties in which they differ are: enzymatic activity, crystalline form, amino nitrogen, titration curve, pH stability range, specific optical rotation, isoelectric point, and the reversibility of heat or alkali denaturation. 4. Conversion of pepsinogen into pepsin at pH 4.6 was found to be autocatalytic; i.e., the pepsin formed catalyzes the reaction. Conversion of pepsinogen into pepsin is accompanied by the splitting off of a portion of the molecule containing 15-20 per cent of the pepsinogen nitrogen. PMID- 19873064 TI - CALCULATIONS OF BIOELECTRIC POTENTIALS : II. THE CONCENTRATION POTENTIAL OF KCl IN NITELLA. AB - Cells of Nitella have been studied which behave differently from those described in earlier papers. They show unexpectedly large changes in P.D. with certain concentrations of KCl. This is due to the production of action currents (these are recorded at the spot where KCl is applied). A method is given for the separate evaluation of changes of P.D. due to partition coefficients and those due to mobilities. A new amplifier and an improved flowing contact are described. PMID- 19873065 TI - THE EXCITABILITY OF FROG MUSCLE WITH PARTICULAR REFERENCE TO ITS LATENT ADDITION. AB - With a view to indicating that the alpha excitatory state in muscle is not of a special nature it is shown that the alpha strength-duration curves are of the same form as those determined for nerve and other tissues except that in about two-thirds of all cases the rheobase appears to be slightly too low. Also from experiments in latent addition it is found that the alpha excitatory state following an inadequate stimulus subsides exponentially at a rate which is related to the alpha excitability in the same way, approximately, as the subsidence rate in nerve is related to the nerve's excitability. In both tissues the subsidence as measured directly is 2-3 times as fast as it appears to be from the strength-duration curve. The alpha refractory period is at least as short as that of nerve so the alpha chronaxie is unusually long compared to the refractory period. There is no reason at present, however, to consider this as having any bearing on the problem at issue. It is concluded therefore, that the alpha excitability differs from others in the rates of its reactions rather than in its fundamental nature and that any conclusions about excitability drawn from its study will probably be valid quite generally. PMID- 19873066 TI - TRANSFORMATION OF SWINE PEPSINOGEN INTO SWINE PEPSIN BY CHICKEN PEPSIN. AB - Activation of swine pepsinogen with chicken pepsin results in the formation of swine pepsin. Activation of chicken pepsinogen with swine pepsin results in the formation of chicken pepsin. The structure responsible for the species specificity of the enzyme is therefore present in the inactive precursor. PMID- 19873067 TI - ELECTRIC IMPEDANCE OF FERTILIZED ARBACIA EGG SUSPENSIONS. AB - From the low frequency alternating current impedance and the volume concentrations of suspensions of Arbacia eggs, it is shown that the high resistance membrane is either at or very near the plasma membrane for both unfertilized and fertilized eggs, and that the specific resistances of the perivitelline space and fertilization membrane are not greatly different from that of sea water. The effect of the capacity element which appears after fertilization at intermediate frequencies is considerably less than in the earlier experiments on Arbacia and Hipponoe eggs. These findings indicate that the fertilization membrane does not have the high capacity previously attributed to it and that the increase in membrane capacity takes place at or near the plasma membrane. PMID- 19873068 TI - ELECTRIC IMPEDANCE OF SINGLE MARINE EGGS. AB - Alternating current impedance measurements have been made on several single marine eggs over the frequency range from 1 to 2500 kilocycles per second. The eggs were placed in the center of a short capillary made by heating the end of a 2 mm. thin walled glass tube until it nearly closed, and electrodes were placed in the sea water on each side of the egg. When it is assumed that the membrane conductance is negligible, the membrane capacity and internal resistances of unfertilized and fertilized Arbacia eggs agree with the values obtained from suspensions. Preliminary data on centrifugally separated half Arbacia eggs, and whole Cumingia and Chaetopterus eggs are given. PMID- 19873069 TI - FORMATION OF TRYPSIN FROM TRYPSINOGEN BY AN ENZYME PRODUCED BY A MOLD OF THE GENUS PENICILLIUM. AB - 1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2. The concentration of kinase in the medium is increased gradually during the growth of the mold organism and continues to increase for some time even after the mold has ceased growing. 3. Mold kinase transforms trypsinogen to trypsin only in an acid medium. It differs thus from enterokinase and trypsin which activate trypsinogen best in a slightly alkaline medium. 4. The action of the mold kinase in the process of transformation of trypsinogen is that of a typical enzyme. The process follows the course of a catalytic unimolecular reaction, the rate of formation of a definite amount of trypsin being proportional to the concentration of kinase added. The ultimate amount of trypsin formed, however, is independent of the concentration of kinase used. 5. The formation of trypsin from trypsinogen by mold kinase is not accompanied by any measurable loss of protein. 6. The temperature coefficient of formation of trypsin from trypsinogen by mold kinase varies from Q(5-15) = 1.70 to Q(25-30) = 1.25 with a corresponding variation in the value of micro from 8100 to 4250. 7. Trypsin formed from trypsinogen by means of mold kinase is identical in crystalline form with the crystalline trypsin obtained by spontaneous autocatalytic activation of trypsinogen at pH 8.0. The two products have within the experimental error the same solubility and specific activity. A solution saturated with the crystals of either one of the trypsin preparations does not show any increase in protein concentration or activity when crystals of the other trypsin preparation are added. 8. The Penicillium mold kinase has a slight activating effect on chymo-trypsinogen the rate being only 1 2 per cent of that of trypsinogen. The activation, as in the case of trypsinogen, takes place only in an acid medium. 9. Mold kinase is rapidly destroyed when brought to pH 6.5 or higher, and also when heated to 70 degrees C. In the temperature range of 50-60 degrees C. the inactivation of kinase follows a unimolecular course with a temperature coefficient of Q(10) = 12.1 and micro = 53,500. The molecular weight of mold kinase, as determined by diffusion, is 40,000. PMID- 19873070 TI - THE MEASUREMENT OF SURFACE FILMS FORMED BY HEMOCYANIN, TOBACCO MOSAIC VIRUS, VACCINIA, AND BACTERIUM GALLINARUM. PMID- 19873071 TI - EFFECTS OF POTASSIUM ON THE POTENTIAL OF HALICYSTIS. AB - Sea water in which sodium has been replaced by potassium produces about the same degree of negativity in Halicystis and in Valonia. With increasing dilution of this sea water up to 1 / 16 the degree of negativity steadily falls off in Halicystis. This differs from the situation in Valonia where Damon finds that with increasing dilution the negativity passes through a minimum after which increasing dilution produces increasing negativity. But conditions in the two organisms differ so greatly that a comparison is of rather doubtful significance. PMID- 19873072 TI - BRIGHTNESS DISCRIMINATION AS A FUNCTION OF THE DURATION OF THE INCREMENT IN INTENSITY. AB - 1. This investigation has been concerned with an analysis of brightness discrimination as it is influenced by the duration of DeltaI. The durations used extend from 0.002 second to 0.5 second. 2. DeltaI/I values at constant intensity are highest for the shortest duration and decrease with an increase in duration up to the limits of a critical exposure time. At durations longer than the critical duration the ratio DeltaI/I remains constant. 3. The Bunsen-Roscoe law holds for the photolysis due to DeltaI. This is shown by the fact that, within the limits of a critical duration, the product of DeltaI and exposure time is constant for any value of prevailing intensity, I. 4. At durations greater than the critical duration the Bunsen-Roscoe law is superseded by the relation DeltaI = Constant. This change of relation is considered in the light of Hartline's discussion (1934). 5. The critical duration is a function of intensity. As intensity increases the critical duration decreases. 6. Hecht's theory (1935) accounts for the data of this experiment if it be assumed that brightness discrimination is determined by a constant amount of photolysis. PMID- 19873073 TI - STUDIES IN THE PHYSICAL CHEMISTRY OF AMINO ACIDS, PEPTIDES, AND RELATED SUBSTANCES : XI. THE SOLUBILITY OF CYSTINE IN THE PRESENCE OF IONS AND ANOTHER DIPOLAR ION. AB - 1. As an introduction to the relations that obtain in biochemical systems containing several components, some ionic, some dipolar ionic, the solubility of cystine has been investigated in the presence of glycine and neutral salts. 2. Both glycine and sodium chloride increase cystine solubility at all concentrations. The interaction between cystine and ions is, however, diminished with increase in glycine concentration, and the interaction between cystine and glycine with increase in ionic strength. 3. Sodium sulfate also increases the solubility of cystine, but at concentrations greater than one molal its solvent action is smaller than its salting-out effect, which is greater at all concentrations than that of sodium chloride, and greater the higher the glycine concentration. 4. These interactions are defined by an equation giving the solubility ratio of cystine in terms of salting-out constants, constants related to the electric moments of cystine, and to the ionic strength and dielectric constant of the solution. 5. The higher the concentration of glycine and therefore the dielectric constant of the solution, the smaller that part of the interaction between ions and dipolar ions which depends upon Coulomb forces and the greater appears the salting-out effect. 6. Conversely, the greater the ionic strength and the salting-out effect the smaller the interaction between dipolar ions in solution. PMID- 19873074 TI - THE ACCUMULATION OF ELECTROLYTES : IX. REPLACEMENT OF AMMONIA BY SODIUM AND POTASSIUM. AB - Experiments on Valonia were carried out as follows: Stage I.-Cells in dim light accumulated 0.08 M ammonia (NH(3) + NH(4)OH + NH(4) (+)) from sea water containing 0.0025 M ammonia (but the concentration of undissociated ammonia appeared to remain less inside than outside). Potassium came out. Stage II.-Cells in dim light in nearly ammonia-free normal sea water lost ammonia which was replaced by sodium entering from the sea water. Potassium in the sap remained practically constant. Stage III.-The cells were placed in stronger light where the loss of ammonia continued and potassium entered. Sodium entered more rapidly than in Stage II. Stage IV.-Cells transferred to sea water containing 0.0025 M ammonia again accumulated ammonia up to 0.1345 M. The results in general harmonize with the view that the direction of movement of a base M through the protoplasm depends on the difference of the activity products (M)(o)(OH)(o) and (M)(i)(OH)(i) where the subscripts o and i refer to sea water and sap respectively. On this basis, if the entrance of ammonia raised the internal concentration of OH sufficiently in Stage I potassium should come out in Stage I, as actually happened. The behavior of sodium is in doubt. If the internal pH in Stage II were sufficiently high sodium should enter but not potassium. This was actually found. In Stage III, if we suppose that the effect of stronger light is to increase the external pH (by photosynthesis) more than the internal pH (as found by Crozier) we can understand why potassium entered, because such an increase in pH could readily make the external value of (K) (OH) greater than the internal. This would also explain why sodium entered more rapidly than in Stage II. When ammonia is coming out of the cell, sodium and potassium may enter more rapidly than usual without raising the internal concentration of halide above a certain critical value at which entrance appears to be checked. PMID- 19873075 TI - THE ACCUMULATION OF ELECTROLYTES : X. ACCUMULATION OF IODINE BY HALICYSTIS AND VALONIA. AB - Analyses of the sap of Halicystis Osterhoutii and of Valonia macrophysa for iodide indicate accumulations of the order of 1000 to 10,000-fold in the first case, and 40 to 250-fold in the second case. The chemical potential of KI, NaI, HI, and CaI(2) is greater inside than outside. PMID- 19873076 TI - SUCROSE INVERSION BY BAKERS' YEAST AS A FUNCTION OF TEMPERATURE. AB - Inversion of sucrose by bakers' yeast follows the same course as inversion catalyzed by yeast invertase. Rate of inversion increases exponentially with temperature; the temperature characteristic in the Arrhenius equation is 10,700 below 13-17 degrees C., and 8,300 above that temperature. Temperature inactivation occurs above 40 degrees C. The effects of temperature upon rate of inversion were the same using Fleischmann's yeast cake, the same yeast killed with toluene, and a pure strain (G. M. No. 21062) of bakers' yeast. The last differed from the other two only in the fact that its critical temperature was 13 degrees C. as compared with 17 degrees C. for the others. The catalytic inversion is associated with enzyme activity inside the cell, not in the medium, and is independent of any vital processes inside the cell such as respiration and fermentation. Since invertase activity is the same inside the cell as it is after extraction, it appears possible to relate the temperature characteristics for physiological processes to the catalytic chemical systems which determine their rate. At least two enzymes are capable of inverting sucrose in the yeast cell. The familiar yeast invertase (micro = 10,700) is active below 13-17 degrees C. while a second enzyme (M = 8,300) plays the dominant role above that temperature. PMID- 19873077 TI - CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : III. SOME EFFECTS OF GUAIACOL ON HALICYSTIS. AB - Lowering the pH of sea water from 8.2 to 6.4 lowers the positive P.D. of Halicystis reversibly (this does not happen with Valonia). Exposure to sea water at pH 6.4 does not affect the apparent mobility of Na(+) or of K(+) (this agrees with Valonia). Guaiacol makes the P.D. of Halicystis less positive (in Valonia it has the opposite effect). Exposure to guaiacol does not reverse the effect of KCl in Halicystis which in this respect differs from Valonia. The P.D. can be changed from 66 mv. positive to 23 mv. negative by the combined action of KCl and guaiacol. Exposure to guaiacol affects Halicystis and Valonia similarly in respect to their behavior with dilute sea water. Normally the dilute sea water makes the P.D. more negative but after sufficient exposure to guaiacol dilute sea water either produces no change in P.D. or makes it more positive. In the latter case we may assume that the apparent mobility of Na(+) has become greater than that of Cl(-) as the result of the action of guaiacol. (Normally the apparent mobility of Cl(-) is greater than that of Na(+).) In Halicystis, as in Valonia and in Nitella, an organic substance can greatly change the apparent mobilities of certain inorganic ions (K(+) or Na(+)). PMID- 19873078 TI - FACTORS LIMITING BACTERIAL GROWTH : III. CELL SIZE AND "PHYSIOLOGIC YOUTH" IN BACTERIUM COLI CULTURES. AB - 1. Measurements of the rate of oxygen uptake per cell in transplants of Bacterium coli from cultures of this organism in different phases of growth have given results in essential agreement with the observations of others. 2. Correlations of viable count, centrifugable nitrogen, and turbidity, with oxygen consumption, indicate that the increased metabolism during the early portion of the growth period is quantitatively referable to increased average size of cells. 3. Indirect evidence has suggested that the initial rate of growth of transplants is not related to the phase of growth of the parent culture. PMID- 19873079 TI - ELECTROKINETIC PHENOMENA : XIII. A COMPARISON OF THE ISOELECTRIC POINTS OF DISSOLVED AND CRYSTALLINE AMINO ACIDS. AB - 1. Although the isoelectric points of dissolved cystine, tyrosine, and aspartic acid molecules lie at widely differing pH values, the isoelectric points of the surfaces of these substances in the crystalline state are all near pH 2.3. This was found to be true in solutions of hydrochloric acid and in acetate buffers of approximately constant ionic strength. 2. When suspended in gelatin, tyrosine and cystine crystals adsorb the protein and attain a surface identical in behavior with gelatin-coated quartz or collodion particles. 3. Aluminum ions at low concentrations reduce the electric mobilities of tyrosine crystals to zero in a manner analogous to their effect on other surfaces. 4. Alkyl benzene droplets also have their electric mobility reduced to zero at low pH values but, unlike the amino acids, a change in sign was never noticed. 5. The mobility of tyrosine crystals is independent of crystal length between 2-100micro. Below this size the mobilities are decreased. 6. These results are discussed in connection with the concept of the general definition of the isoelectric point and the behavior of certain insoluble proteins such as wool and silk fibroin. PMID- 19873080 TI - THE ADSORPTION OF PROTEINS AT OIL-WATER INTERFACES AND ARTIFICIAL PROTEIN-LIPOID MEMBRANES. PMID- 19873081 TI - TRANSVERSE ELECTRIC IMPEDANCE OF THE SQUID GIANT AXON. AB - The impedance of the excised giant axon from hindmost stellar nerve of Loligo pealii has been measured over the frequency range from 1 to 2500 kilocycles per second. The measurements have been made with the current flow perpendicular to the axis of the axon to permit a relatively simple analysis of the data. It has been found that the axon membrane has a polarization impedance with an average phase angle of 76 degrees and an average capacity of 1.1microf./cm(2) at 1 kilocycle. The direct current resistance of the membrane could not be measured, but was greater than 3 ohm cm.(2) and the average internal specific resistance was four times that of sea water. There was no detectable change in the membrane impedance when the axon lost excitability, but some time later it decreased to zero. PMID- 19873082 TI - THE ACCUMULATION OF ELECTROLYTES : XI. ACCUMULATION OF NITRATE BY VALONIA AND HALICYSTIS. AB - The nitrate concentration in the sap of Valonia macrophysa, Kutz., is at least 2000 times that of the sea water, and in Halicystis Osterhoutii, Blinks and Blinks, at least 500 times that of the sea water. PMID- 19873083 TI - THE ACCUMULATION OF ELECTROLYTES : XII. ACCUMULATION OF HALIDE AND NITRATE BY VALONIA IN HYPERTONIC SOLUTIONS. AB - When cells of Valonia macrophysa were placed in hypertonic sea water, the concentration of halide and of nitrate increased, and the sum of halide + nitrate became 0.05 M greater inside than outside, which is about the same difference as is found in cells in normal sea water. In ordinary sea water the ratio of halide to nitrate is 80,000 to 1. When this was changed by substituting nitrate for halide so that the concentration of halide was 1.75 times that of nitrate the rate of entrance of halide was 1.68 times that of nitrate in 276 hours and the ratio of halide to nitrate in the sap decreased from 38 to 18.5. No halide came out in exchange for entering nitrate. The retention of chloride may well be due to the fact that even when the halide concentration of the sea water is reduced as low as 0.4 M, there is still an inwardly directed activity gradient of sodium chloride. PMID- 19873084 TI - EXCITATION OF NERVE FIBERS IN THE SQUID (LOLIGO PEALII). AB - 1. Strength-duration data for the giant fiber of the great stellar nerve of the squid (Loligo pealii) can be approximately described by several mathematical formulations. 2. Excitation time constants for isolated giant fibers are essentially the same as constants of the giant fibers in the intact nerve. 3. The strength-duration curves of the fibers in the intact nerve lie higher on the voltage axis than those of the isolated fibers. It is concluded that the principal effect of other fibers upon the excitation of one fiber in a nerve trunk is that of shunting the stimulating current. 4. Deterioration of the nerve shifts the curve upward and to the left, resulting in shorter time constants. 5. Decreasing interelectrode distance also shifts the curve upward and to the left. 6. Excitation time constants of the giant fibers are larger with plate electrodes than with wire or pore electrodes. 7. The strength-duration curves of the smaller fin nerve fibers lie consistently to the right of, and the time constants are longer than those of the giant fibers. PMID- 19873085 TI - ON RHODOPSIN IN SOLUTION. AB - 1. The properties of rhodopsin in solution have been examined in preparations from marine fishes, frogs, and mammals. 2. The bleaching of neutral rhodopsin in solution includes a photic and at least three thermal ("dark") processes. Thermal reactions account for approximately half the total fall in extinction at 500 mmicro. 3. Bleaching has been investigated at various pH's from 3.9 to about 11. With increase in pH the velocity of the thermal components increases rapidly. Though the spectrum of rhodopsin itself is scarcely affected by change in pH, the spectra of all product-mixtures following irradiation are highly pH-labile. 4. The spectrum of pure rhodopsin-or of the rhodopsin chromophore-is fixed within narrow limits. The extinction at 400 mmicro lies between 0.20 to 0.32 of that at the maximum. 5. Within the limitations of available data, the spectrum of pure rhodopsin corresponds in form and position with the spectral sensitivity of human rod vision, computed at the retinal surface. 6. The nature of bleaching of rhodopsin in solution, its kinetics, and its significance in the retinal cycle are discussed. PMID- 19873086 TI - THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS : III. GRADIENTS OF HYDROGEN ION CONCENTRATION. AB - 1. Gradients of hydrogen ion concentration across Fucus eggs growing in sea water determine the developmental polarity of the embryo. 2. Gradients may determine polarity even if removed before the morphological response begins. 3. The rhizoid forms on the acid side of the egg unless this is too acid, in which case it develops on the basic side of the egg. 4. Since gradients of hydrogen ion concentration in sea water produce gradients of CO(2) tension, as a result of chemical action on the carbonate buffer system, it is not proven whether the physiological effects are due to the hydrogen ions, or to the CO(2) which they produce in the medium. 5. The developmental response of the eggs to gradients of hydrogen ion (or CO(2)) concentration provides an adequate but not an exclusive explanation of the group effect in Fucus. 6. Hydrogen ions may exert their effect by activating growth substance. Hydrogen ions or CO(2) probably also affect the underlying rhizoid forming processes in other ways as well. PMID- 19873087 TI - THE ELECTROPHORETIC MOBILITY OF HUMAN ERYTHROCYTES-WHOLE CELLS, GHOSTS, AND FRAGMENTS. AB - The electrophoretic mobility of human red cell ghosts decreases in the presence of chicken serum. The decrease is not directly due to the presence of adsorbed material but to a change which is catalyzed by the foreign substance. It is suggested that abnormal serum materials resulting from disease may serve as catalysts. Fragments of broken cells have the same mobility as whole cells at first, then decrease even in pure salt suspension, while the whole cells remain essentially unchanged for hours. The results suggest that the slow change of whole cells, the change of ghosts in the presence of foreign serum, and the change of fragments are all manifestations of the same modification of structure or composition of the cell surface. PMID- 19873088 TI - DELAYED POTASSIUM EFFECT IN NITELLA. AB - In normal cells of Nitella replacement of NaCl by KCl makes the P.D. much less positive: this is called the potassium effect. Cells which have lost the potassium effect usually show little or no change of P.D. when NaCl is replaced by KCl but an occasional cell responds after a delay. It seems possible that the delay may be largely due to the time required for potassium to combine with an organic substance, thus forming a compound which sensitizes the protoplasmic surface to the action of potassium. PMID- 19873089 TI - PACEMAKERS IN NITELLA : II. ARRHYTHMIA AND BLOCK. AB - Many forms of irregular rhythm and of partial block occurring in the vertebrate heart can be duplicated in Nitella. In order to observe these phenomena the cells of Nitella are kept for 6 weeks or more in a nutrient solution. They are then exposed for 3 hours or less to 0.01 M NaCl, NaSCN, or guanidine chloride, which reduce the time required for the action current to about 1 second (the normal time is 15 to 30 seconds). A pacemaker is established at one end of the cell by placing it in contact with 0.01 M KCl. This produces action currents at the rate of about 1 a second. Apparently some parts of the cell are unable to follow this rapid pace and hence fall into irregular rhythms (arrhythmia) and fail to register all the impulses (partial block). PMID- 19873090 TI - LIMITING FACTORS IN PHOTOSYNTHESIS: LIGHT AND CARBON DIOXIDE. AB - 1. Extensive measurements have been obtained (a) relating photosynthesis and light intensity for a large range of CO(2) concentrations and (b) relating photosynthesis and CO(2) at different light intensities. From these families of curves, the limiting factor relationship can be secured for any value of the photosynthesis rate. 2. In terms of previous work an equation has been derived for describing these relations between the intensity and CO(2) concentration necessary to produce a definite amount of photosynthesis. This equation furnishes an exact description for all the data, except those for low rates of photosynthesis where a slightly different equation is required. The nature of the two equations suggests that a simple first order reaction determines the velocity of the light process at low photosynthesis rates, but that at high rates the mechanism is complicated by another factor. PMID- 19873091 TI - ELECTRIC IMPEDANCE OF NITELLA DURING ACTIVITY. AB - The changes in the alternating current impedance which occur during activity of cells of the fresh water plant Nitella have been measured with the current flow normal to the cell axis, at eight frequencies from 0.05 to 20 kilocycles per second, and with simultaneous records of the action potential under the impedance electrodes. At each frequency the resting cell was balanced in a Wheatstone bridge with a cathode ray oscillograph, and after electrical stimulation at one end of the cell, the changes in the complex impedance were determined from the bridge unbalance recorded by motion pictures of the oscillograph figure. An extension of the previous technique of interpretation of the transverse impedance shows that the normal membrane capacity of 0.9 microf./cm.(2) decreases about 15 per cent without change of phase angle, while the membrane resistance decreases from 10(5) ohm cm.(2) to about 500 ohm cm.(2) during the passage of the excitation wave. This membrane change occurs during the latter part of the rising phase of the action potential, and it is shown that the membrane electromotive force remains unchanged until nearly the same time. The part of the action potential preceding these membrane changes is probably a passive fall of potential ahead of a partial short circuit. PMID- 19873092 TI - KINETICS OF THE FORMATION OF PEPSIN FROM SWINE PEPSINOGEN AND IDENTIFICATION OF AN INTERMEDIATE COMPOUND. AB - A study of the kinetics of the transformation of swine pepsinogen into pepsin under a variety of conditions has been made. The results show that the transformation as a whole is essentially autocatalytic in nature under all conditions. Evidence is presented to show the existence of a compound intermediate between pepsinogen and pepsin. This compound was found to be a reversibly dissociable complex of pepsin and a low molecular weight inhibitor. Some of the general properties of the intermediate compound and of the inhibitor have been examined. PMID- 19873093 TI - INTENSITY DISCRIMINATION IN THE HUMAN EYE : II. THE RELATION BETWEENDeltaI/IAND INTENSITY FOR DIFFERENT PARTS OF THE SPECTRUM. AB - 1. A new apparatus is described for measuring visual intensity discrimination over a large range of intensities, with white light and with selected portions of the spectrum. With it measurements were made of the intensity DeltaI which is just perceptible when it is added for a short time to a portion of a field of intensity I to which the eye has been adapted. 2. For white and for all colors the fraction DeltaI/I decreases as I increases and reaches an asymptotic minimum value at high values of I. In addition, with white light the relation between DeltaI/I and I shows two sections, one at low intensities and the other at high intensities, the two being separated by an abrupt transition. These findings are contrary to the generally accepted measurements of Koenig and Brodhun; however, they confirm the recent work of Steinhardt, as well as the older work of Blanchard and of Aubert. The abrupt transition is in keeping with the Duplicity theory which attributes the two sections to the functions of the rods and cones respectively. 3. Measurements with five parts of the spectrum amplify these relationships in terms of the different spectral sensibilities of the rods and cones. With extreme red light the relation of DeltaI/I to I shows only a high intensity section corresponding to cone function, while with other colors the low intensity rod section appears and increases in extent as the light used moves toward the violet end of the spectrum. 4. Like most of the previously published data from various sources, the present numerical data are all described with precision by the theory which supposes that intensity discrimination is determined by the initial photochemical and chemical events in the rods and cones. PMID- 19873094 TI - THE ESTIMATION OF PEPSIN, TRYPSIN, PAPAIN, AND CATHEPSIN WITH HEMOGLOBIN. PMID- 19873095 TI - NATURE OF THE ACTION CURRENT IN NITELLA : IV. PRODUCTION OF QUICK ACTION CURRENTS BY EXPOSURE TO NACl. AB - Treatment of Nitella with NaCl greatly reduces the time required for the action current and produces an action curve with one peak instead of the customary two. The time may be reduced to 0.6 second in place of the usual 15 to 30 seconds. This might be expected if the treatment increased the conductivity of the aqueous part of the protoplasm. The experiments favor this idea although they do not prove its correctness. This effect is prevented by calcium, possibly because calcium inhibits penetration of salts. That penetration is an important factor is indicated by the fact that salts which might be expected to penetrate rapidly have the most effect. Thus NaSCN is more effective than NaCl but Na(2)SO(4) has little or no effect. The action of NH(4)Cl and LiCl is similar to that of NaCl. PMID- 19873096 TI - EFFECT OF SODIUM SULFATE ON THE PHAGE-BACTERIUM REACTION. AB - Bacteriophagy taking place in the presence of M/8 Na(2)SO(4) has the following pronounced characteristics: A. Time of lysis is considerably prolonged. B. The bacteria take up less than the normal amount of phage. C. Phage production occurs at one-third the customary rate. D. It takes four times as much phage to lyse a Na(2)SO(4)-treated bacterium than a normal one. E. Bacterial growth is not affected by Na(2)SO(4). The lag phase and the lowered rate of phage production can be attributed to the Na(2)SO(4) effect on the cell surface. Less phage is taken up by the cells and contact of phage with the bacterium's precursor producing mechanism is impeded. PMID- 19873097 TI - CALCULATIONS OF BIOELECTRIC POTENTIALS : IV. SOME EFFECTS OF CALCIUM ON POTENTIALS IN NITELLA. AB - In Nitella the substitution of KCl for NaCl changes the P.D. in a negative direction. In some cases this change is lessened by adding solid CaCl(2) to the solution of KCl. This may be due to lessening the partition coefficient of KCl or to decreasing the solubility of an organic substance which sensitizes the cell to the action of KCl. Little or no correlation exists between this effect of calcium and its ordinary antagonistic action in producing a balanced solution which preserves the life of the cell indefinitely. CaCl(2) is negative to NaCl but positive to KCl. The effects of mixtures of KCl, NaCl, and CaCl(2) are discussed. The concentration effect of a mixture of KCl + CaCl(2) shows certain peculiarities due to action currents: these resemble those found with pure KCl. These studies and others on Nitella, Valonia, and Halicystis indicate that mobilities and partition coefficients are variable and can be brought under experimental control. PMID- 19873098 TI - THE KINETICS OF PENETRATION : XV. THE RESTRICTION OF THE CELLULOSE WALL. AB - When Valonia cells are impaled on capillaries, it is in some ways equivalent to removing the comparatively inelastic cellulose wall. Under these conditions sap can migrate into a free space and it is found that on the average the rate of increase of volume of the sap is 15 times what it is in intact cells kept under comparable conditions. The rate of increase of volume is a little faster during the first few hours of the experiment, but it soon becomes approximately linear and remains so as long as the experiment is continued. The slightly faster rate at first may mean that the osmotic pressure of the sap is approaching that of the sea water (in the intact cell the sap osmotic pressure is always slightly above that of the sea water). This might result from a more rapid entrance of water than of electrolyte, as would be expected when the restriction of the cellulose wall was removed. During the linear part of the curve the osmotic concentration and the composition of the sap suffer no change, so that entrance of electrolyte must be 15 times as fast in the impaled cells as it is in the intact cells. The explanation which best accords with the facts is that in the intact cell the entrance of electrolyte tends to increase the osmotic pressure. As a consequence the protoplasm is partially dehydrated temporarily and it cannot take up more water until the cellulose wall grows so that it can enclose more volume. The dehydration of the protoplasm may have the effect of making the non-aqueous protoplasm less permeable to electrolytes by reducing the diffusion and partition coefficients on which the rate of entrance depends. In this way the cell is protected against great fluctuations in the osmotic concentration of the sap. PMID- 19873099 TI - THE PARTIAL REACTIVATION OF FORMOLIZED TOBACCO MOSAIC VIRUS PROTEIN. AB - A marked reactivation of tobacco mosaic virus protein that has been partially or completely inactivated by formaldehyde was obtained by dialysis at pH 3. The activity of partially inactivated virus proteins was generally increased about 10 fold by the reactivation process. It was also found possible to reactivate completely inactive preparations to an appreciable extent. It was shown that the inactivation and the subsequent reactivation cannot be explained by the toxicity of the formaldehyde or of the formolized protein or by aggregation. Inactivation was accompanied by a decrease in amino groups as indicated by Van Slyke gasometric determinations and by colorimetric estimations using ninhydrin. Inactivation also causes a decrease in the number of groups that react with Folin's reagent at pH 7.7. The latter are probably the indole nuclei of tryptophane, for it was demonstrated that tryptophane, glycyltryptophane, and indole propionic acid react with formaldehyde in a similar manner, while tyrosine and glycyltyrosine do not. Evidence that reactivation is accompanied by an increase in amino nitrogen and in groups that react with Folin's reagent was obtained by colorimetric estimation. The demonstration that the addition of formaldehyde to the virus protein results in a simultaneous decrease of activity, of amino groups, and of groups that react with Folin's phenol reagent, and that under conditions favorable for the removal of formaldehyde the virus activity is regained and the number of such groups increases, indicates that certain of these groups play at least a partial role in the structure necessary for virus activity. These changes can best be interpreted on the basis of known chemical reactions and are considered as evidence that virus activity is a specific property of the protein. PMID- 19873100 TI - CHEMICAL CHANGES IN THE ADDUCTOR MUSCLE OF THE CHELIPED OF THE CRAYFISH IN RELATION TO THE DOUBLE MOTOR INNERVATION. AB - An investigation has been made of the phosphate and lactic acid changes in the adductor muscle of the cheliped of the crayfish Cambarus clarkii upon stimulation of the isolated axons for the fast and slow contractions at determined frequencies. The data obtained point to the following conclusions: 1. When the mechanical effects of the two types of contraction are the same, the chemical changes are of the same order. If the mechanical effects are different, the chemical changes likewise are not equivalent. This is especially to be seen in the case of stimulation at 50 shocks per second: a slowly rising, long continued, strong slow contraction takes place with no apparent change in the phosphate content; a quickly rising fast contraction occurs with a large increase in the phosphate. 2. Since equivalent chemical changes accompany equivalent mechanical action, the two types of contraction do not differ in the essential mechanism of the chemical changes involved, and only one type of contractile substance is present. 3. Even when a contraction has taken place to the maximum extent obtainable, only enough phosphate is found to correspond to one-fifth to one third of the available phosphagen. PMID- 19873101 TI - FORMATION OF NEW CRYSTALLINE ENZYMES FROM CHYMOTRYPSIN : ISOLATION OF BETA AND GAMMA CHYMOTRYPSIN. AB - A solution of chymotrypsin on slight hydrolysis undergoes an irreversible change into new proteins, two of which are enzymes and have been isolated in crystalline form. The new crystalline enzymes, called beta and gamma chymotrypsins, differ from the original chymotrypsin as well as from each other in many physical and chemical respects, such as molecular weight, crystalline form, solubility, and combining capacity with acid. The new enzymes still possess the same enzymatic properties as chymotrypsin. It thus appears that the irreversible change from chymotrypsin to the new enzymes does not affect the structure responsible for the enzymatic activity of the molecule. The solubility curves of the new enzymes agree approximately with the curves for a solid phase of one component and furnish very good evidence that the preparations represent distinct substances. The various enzymes when mixed at the proper pH have a tendency to form mixed crystals of the solid solution type. Thus at pH 4.0 gamma chymotrypsin combines to form solid solution crystals with either alpha or beta chymotrypsin. Hence at this pH separation of gamma from either alpha or beta by means of fractional crystallization is impossible. At pH 5.0-6.0, however, each material crystallizes in its own characteristic form and at its own rate; thus a fractional separation of the various enzymes from each other becomes feasible. PMID- 19873102 TI - DEVELOPMENT OF EYE COLORS IN DROSOPHILA: SOME PROPERTIES OF THE HORMONES CONCERNED. AB - The substance inducing the production of pigment in the eyes of vermilion brown mutants of Drosophila melanogaster has been shown to be a relatively stable chemical entity possessing true hormone-like activity. A simple method for obtaining hormone solutions has been developed involving extraction of dried wild type Drosophila pupae with ethyl alcohol and water. A logarithmic proportionality has been found to exist between the amount of hormone and the induced eye color. This relationship provides a simple method for the quantitative determination of hormone concentration in given extracts. Larvae and pupae of D. melanogaster contain an intracellular enzyme which inactivates the hormone in the presence of molecular oxygen. The hormone is not oxidized under ordinary conditions with either molecular oxygen or hydrogen peroxide. The hormone has been found to be an amphoteric compound with both acidic and basic groups and with a molecular weight between 400 and 600. The solubility and precipitation reactions of the hormone suggest its amino acid-like nature. However, the instability to heat, acid, and alkali, and its rather restricted occurrence indicate a rather complex specific structure. PMID- 19873103 TI - BIOELECTRIC POTENTIALS IN HALICYSTIS : VII. THE EFFECTS OF LOW OXYGEN TENSION. AB - The potential difference across the protoplasm of impaled cells of Halicystis is not affected by increase of oxygen tension in equilibrium with the sea water, nor with decrease down to about 1/10 its tension in the air (2 per cent O(2) in N(2)). When bubbling of 2 per cent O(2) is stopped, the P.D. drifts downward, to be restored on stirring the sea water, or rebubbling the gas. Bubbling 0.2 per cent O(2) causes the P.D. to drop to 20 mv. or less; 1.1 per cent O(2) to about 50 mv. Restoration of 2 per cent or higher O(2) causes recovery to 70 or 80 mv. often with a preliminary cusp which decreases the P.D. before it rises. Perfusion of aerated sea water through the vacuole is just as effective in restoring the P.D. as external aeration, indicating that the direction of the oxygen gradient is not significant. Low O(2) tension also inhibits the reversed, negative P.D. produced by adding NH(4)Cl to sea water, 0.2 per cent O(2) bringing this P.D. back to the same low positive values found without ammonia. Restoration of 2 per cent O(2) or air, restores this latent negativity. At slightly below the threshold for ammonia reversal, low O(2) may induce a temporary negativity when first bubbled, and a negative cusp may occur on aeration before positive P.D. is regained. This may be due to a decreased consumption of ammonia, or to intermediate pH changes. The locus of the P.D. alteration was tested by applying increased KCl concentrations to the cell exterior; the large cusps produced in aerated solutions become greatly decreased when the P.D. has fallen in 0.2 per cent O(2). This indicates that the originally high relative mobility or concentration of K(+) ion has approached that of Na(+) in the external protoplasmic surface under reduced O(2) tension. Results obtained with sulfate sea water indicate that Na(+) mobility approaches that of SO(4) (-) in 0.2 per cent O(2). P.D. measurements alone cannot tell whether this is due to an increase of the slower ion or a decrease of the faster ion. A decrease of all ionic permeability is indicated, however, by a greatly increased effective resistance to direct current during low O(2). Low resistance is regained on aeration. The resistance increase resembles that produced by weak acids, cresol, etc. Acids or other substances produced in anaerobiosis may be responsible for the alteration. Or a deficiency of some surface constituent may develop. In addition to the surface changes there may be alterations in gradients of inorganic or organic ions within the protoplasm, but there is at present no evidence on this point. The surface changes are probably sufficient to account for the phenomena. PMID- 19873104 TI - THE INFLUENCE OF THE MOLECULAR WEIGHT OF ANTIGEN ON THE PROPORTION OF ANTIBODY TO ANTIGEN IN PRECIPITATES : II. A STATISTICAL EXAMINATION OF AVAILABLE DATA, INCLUDING SOME PREVIOUSLY UNPUBLISHED. AB - A statistical examination of the available data on the ratio of antibody to antigen in specific precipitates made at or near the optimum shows a definite correlation between the ratio and the molecular weight of antigen (regression coefficient = -0.529 (+/-0.014)). The authors' assumption that at this point the antigen molecules are just about covered by a layer of antibody behaving as contiguous spherical ("Svedberg") units of weight 35,200 leads to predicted ratios that in general agree well with those found, though individual experimental determinations may deviate considerably. PMID- 19873105 TI - EFFECT OF THE FORMATION OF INERT PROTEIN ON THE KINETICS OF THE AUTOCATALYTIC FORMATION OF TRYPSIN FROM TRYPSINOGEN. AB - A solution of crystalline trypsinogen in dilute buffer containing a trace of active trypsin when allowed to stand at pH 5.0-9.0 and 5 degrees C. is gradually transformed partly into trypsin protein and partly into an inert protein which can no longer be changed into trypsin either by enterokinase or mold kinase. During the process of formation of trypsin and inert protein the ratio of the concentrations of the two products in any reaction mixture remains constant and is independent of the original concentration of trypsinogen protein. This ratio varies, however, with the pH of the solution, the proportion of trypsin formed being greater in the acid range of pH. The experimental curves for the rate of formation of trypsin, as well as for the rate of formation of inert protein are symmetrical S shaped curves closely resembling those of simple autocatalytic reactions. The kinetics of formation of trypsin and inert protein can be explained quantitatively on the theoretical assumptions that both reactions are of the simple unimolecular type, that in each case the reaction is catalyzed by trypsin, and that the rate of formation of each of the products is proportional to the concentration of trypsin as well as to the concentration of trypsinogen in solution. PMID- 19873106 TI - THE FLICKER RESPONSE FUNCTION FOR THE TURTLE PSEUDEMYS. AB - 1. At constant temperature, with a fixed proportion of light time in a flash cycle (namely, t(L)/t(D) = 1), the mean critical intensity for motor response to visual flicker by the turtle Pseudemys scripta follows a probability integral (log I) as a function of flash frequency F. The fit is close and satisfactory; certain quite minor but consistent deviations are adequately explained by features of the experiments. 2. The variation (sigma(I)) of critical I is directly proportional to the mean critical intensity (I(m)), over the entire explorable range. 3. These facts are consistent with the fact that the retina of this turtle is devoid of rods. It contains only cones, histologically, which, with their central representations, provide a single population of sensory effects. The properties of this population are compared with those of homologous populations deduced from corresponding measurements with other forms (various fishes; amphibian; man) which exhibit two such groups of sensory effects associated with the possession of retinal rods and cones. 4. Certain other formulations which have previously been applied to homologous data obtained with other organisms do not properly describe the Pseudemys measurements. 5. The use of a probability integral to describe the data of response to visual flicker for the dissection of the compound curves provided by animals possessing both rods and cones, is accordingly Justified. 6. Persisting differences among individuals of Pseudemys as regards the values of the critical flash intensity under various conditions of experimentation are of the same order of magnitude as are the transitory differences found in lots of other kinds of animals. 7. Determinations of mean critical flash frequency (F(m)) at fixed levels of I lie slightly above determinations of I(m) at fixed values of I, as with other forms. The variation of critical flash frequency goes through a maximum as log I is increased; its height is lower than with certain other forms, in correlation with the low general slope of the F - log I curve (more properly, band). 8. These facts are consistent with the view that the dispersions of the individual critical intensities (and flash frequencies) are determined by organic variation rather than by "experimental error." 9. When the temperature is altered the F - log I(m) curve is shifted, with no change of F(max.) or of shape; the curve moves to lower intensities as the temperature is raised. 10. The reciprocal of the mean critical intensity, at fixed flash frequency, is a measure of excitability. With increase of temperature (12.5 degrees to 36 degrees ) 1/I(m) for given F follows the Arrhenius equation, exhibiting a "break" at 29.5 degrees (micro = 26,700, 12.5 degrees to 29.5 degrees ; 12,400, 29.5 degrees to 36 degrees ). This is explained by the necessary theory that, the number of elements of sensory effect required for the index response at fixed F being constant, the ease of their excitation is governed by temperature through its control of the velocity of an interrelated system of catalyzed processes common to all of the sensory elements concerned. PMID- 19873107 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : I. A VISUAL DISCRIMINOMETER. II. THRESHOLD STIMULUS INTENSITY AND RETINAL POSITION. AB - Monocular threshold stimulus intensities (DeltaI(o), photons) were measured along the 0-180 degrees meridian of human retinae for three observers. The test image was small (= 0.08 degrees ) and of short duration (= 0.20 second). DeltaI(o) was found to decrease as the angular distance from the fovea was increased. Actual counts of the number of retinal elements per mm.(2) along the 0-180 degrees meridian (Osterberg) were compared with the obtained results. No direct correlation was found to exist between visual sensitivity and the number of retinal elements. Binocular threshold stimuli were also measured along the same meridian. The form of the function relating binocular visual sensitivity and retinal position was discovered to be essentially similar to that for monocular sensitivity, but is more symmetrical about the center of the fovea. The magnitude of the binocular measurement is in each case smaller than that of the monocular threshold stimulus intensity for the more sensitive eye. The ratio is statistically equal to 1.4 (a fact which suggests Piper's rule). These results are shown to be consistent with the hypothesis that the process critical for the eventuation of the threshold response is localized in the central nervous system. They are not consistent with the view that the quantitative properties of visual data are directly determined by properties of the peripheral retina. PMID- 19873108 TI - THE GROWTH OF BACTERIOPHAGE. AB - 1. An anti-Escherichia coli phage has been isolated and its behavior studied. 2. A plaque counting method for this phage is described, and shown to give a number of plaques which is proportional to the phage concentration. The number of plaques is shown to be independent of agar concentration, temperature of plate incubation, and concentration of the suspension of plating bacteria. 3. The efficiency of plating, i.e. the probability of plaque formation by a phage particle, depends somewhat on the culture of bacteria used for plating, and averages around 0.4. 4. Methods are described to avoid the inactivation of phage by substances in the fresh lysates. 5. The growth of phage can be divided into three periods: adsorption of the phage on the bacterium, growth upon or within the bacterium (latent period), and the release of the phage (burst). 6. The rate of adsorption of phage was found to be proportional to the concentration of phage and to the concentration of bacteria. The rate constant k(a) is 1.2 x 10(-9) cm.(8)/min. at 15 degrees C. and 1.9 x 10(-9) cm.(8)/min. at 25 degrees . 7. The average latent period varies with the temperature in the same way as the division period of the bacteria. 8. The latent period before a burst of individual infected bacteria varies under constant conditions between a minimal value and about twice this value. 9. The average latent period and the average burst size are neither increased nor decreased by a fourfold infection of the bacteria with phage. 10. The average burst size is independent of the temperature, and is about 60 phage particles per bacterium. 11. The individual bursts vary in size from a few particles to about 200. The same variability is found when the early bursts are measured separately, and when all the bursts are measured at a late time. PMID- 19873109 TI - THE ANTAGONISM BETWEEN SODIUM AND MAGNESIUM IONS IN THEIR ACTION UPON OXALATE ION. AB - The action of NaCl upon the effect of MgCl(2) upon oxalate buffer systems, interpreted by Simms as an instance of antagonism of Na(+) and Mg(++), has been shown to be capable of formulation as the effect of increasing ionic strength upon the dissociation of MgC(2)O(4) into magnesium and oxalate ions. PMID- 19873110 TI - ON THE DISTRIBUTION OF VITAMINS A(1) AND A(2). AB - The distribution of vitamins A(1) and A(2) has been determined in the eye tissues and livers of a number of fishes. The vitamins were differentiated by means of the antimony chloride reaction, which yields with A(1) a band at 615-620 mmicro and with A(2) a band at about 696 mmicro. In the retina the presence of vitamin A(1) is diagnostic of the operation of a rhodopsin, and vitamin A(2) of a porphyropsin cycle. The eye tissues of all permanently marine fishes examined, except the tautog, contain vitamin A(1) alone. Those of all permanently freshwater fishes possess only vitamin A(2). Those of all euryhaline (potentially migratory) fishes, except possibly the alewife, contain mixtures of both vitamins A, and always predominantly that one which ordinarily is associated with the environment in which the fish is spawned. These correlations extend in part to the liver oils, but most livers contain mixtures of both vitamins A, and occasionally in proportions the reverse of those in the eye tissues. The vitamin A configuration does not depend upon environmental circumstances, but is determined genetically. The transfer from vitamin A(1) to A(2) metabolism appears associated phylogenetically with migration of marine teleosts into fresh water. PMID- 19873111 TI - CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM : IV. INFLUENCE OF GUAIACOL ON THE EFFECTS OF SODIUM AND POTASSIUM IN NITELLA. AB - In Nitella, as in Halicystis, guaiacol increases the mobility of Na(+) in the outer protoplasmic surface but leaves the mobility of K(+) unaffected. This differs from the situation in Valonia where the mobility of Na(+) is increased and that of K(+) is decreased. The partition coefficient of Na(+) in the outer protoplasmic surface is increased and that of K(+) left unchanged. Recovery after the action current is delayed in the presence of guaiacol and the action curves are "square topped." PMID- 19873112 TI - FORMATION OF TRYPSIN FROM CRYSTALLINE TRYPSINOGEN BY MEANS OF ENTEROKINASE. AB - Crystalline trypsinogen is most readily and completely transformed into trypsin by means of enterokinase in the range of pH 5.2-6.0 at 5 degrees C. and at a concentration of trypsinogen of not more than 0.1 mg. per ml. The action of enterokinase under these conditions is that of a typical enzyme. The process follows closely the course of a catalytic unimolecular reaction, the rate of formation of trypsin being proportional to the concentration of enterokinase added and the ultimate amount of trypsin formed being independent of the concentration of enterokinase. The catalytic action of enterokinase on crystalline trypsinogen in dilute solution at pH more alkaline than 6.0 and in concentrated solution at pH even slightly below 6.0 is complicated by the partial transformation of the trypsinogen into inert protein which can no longer be changed into trypsin even by a large excess of enterokinase. This secondary reaction is catalyzed by the trypsin formed and the rate of the reaction is proportional to the concentration of trypsin as well as to the concentration of trypsinogen in solution. Hence under these conditions only a small part of the trypsinogen is changed by enterokinase into trypsin while a considerable part of the trypsinogen is transformed into inert protein, the more so the lower the concentration of enterokinase used. The kinetics of the formation of trypsin by means of enterokinase when accompanied by the formation of inert protein can be explained quantitatively on the theoretical assumption that both reactions are of the simple catalytic unimolecular type, the catalyst being enterokinase in the first reaction and trypsin in the second reaction. PMID- 19873113 TI - PURIFICATION AND CONCENTRATION OF ENTEROKINASE. AB - A concentrated solution of purified enterokinase is conveniently prepared from the fluid contents of pigs' duodena by means of fractional precipitation with ammonium sulfate under the proper pH conditions. PMID- 19873114 TI - THE FLICKER RESPONSE CONTOUR FOR THE ISOPOD ASELLUS. AB - The flicker response contour for the isopod Asellus is a simple probability integral (F - log I) over the whole determinable range (F = 1 to 51). This contrasts with the "distorted" asymmetrical curves obtained with Apis, Anax, and other arthropods with large convex eyes. The explanation of the distortion as due to mechanical conditions affecting photoreception is therefore confirmed, as the structure of the Asellus eye does not make such a factor likely to be expected for this case. The Asellus curve agrees with the only other available complete and uncomplicated flicker response contour (from Pseudemys, turtle with rod-free retina), in showing the superiority of the probability integral formulation as compared with certain others which have been suggested. It is noted as a curious and probably important fact that the relative dispersion of the intensity thresholds (sigma'(log I)) for the elements implicated in determining the flicker contour appears to be identical in bee, dragon fly nymph, and isopod. Other relevant information derived from similar experiments with vertebrates shows that this quantity is specifically determined by the organization of the animal. The nature of the common feature of neural organization in three such diverse arthropods, as contrasted with the diversity seen within one class of vertebrates (e.g., teleosts), remains to be discovered. PMID- 19873115 TI - THE FLICKER RESPONSE CONTOURS FOR GENETICALLY RELATED FISHES. II. AB - The flicker response contour has been determined for several species and types of the teleosts Xiphophorus (X.) and Platypoecilius (P.) under the same conditions. The curve (F vs. log I(m)) is the same for representatives of each generic type, but is different for the two genera. Its duplex nature is analyzable in each instance by application of the probability integral equation to the rod and cone constituent parts. The parameters of this function provide rational measures of invariant properties of the curves, which have specific values according to the genetic constitution of the animal. The F(1) hybrids (H'') of X. montezuma x P. variatus show dominance of the X. properties with respect to cone F(max.) and sigma' (log I), but an intermediate value of the abscissa of inflection (tau'). The rod segment shows dominance of sigma' (log I) from P., but an intermediate value of F(max.) and of tau'. The composite flicker curve involves the operation of two distinct assemblages of excitable elements, differing quantitatively but not qualitatively in physicochemical organization, probably only secondarily related to the histological differentiation of rods and cones because almost certainly of central nervous locus, but following different rules in hereditary determination, and therefore necessarily different in physical organization. The interpretation of the diverse behavior of the three parameters of the probability summation is discussed, particularly in relation to the physical significance of these parameters as revealed by their quantitative relations to temperature, retinal area, and light time fraction in the flash cycle, and to their interrelations in producing the decline of rod effects at higher intensities. It is stressed that in general the properties of the parameters of a chosen interpretive analytical function must be shown experimentally to possess the physical properties implied by the equation selected before the equation can be regarded as describing those invariant properties of the organic system concerned upon which alone can deduction of the nature of the system proceed. The importance of genetic procedures in furthering demonstration that the biological performance considered in any particular case exhibits constitutionally invariant features provides a potentially powerful instrument in such rational analysis. PMID- 19873116 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : III. SUNFISH. AB - For the sunfish Enneacanthus the mean value of the critical illumination for response to visual flicker at constant flash frequency (with light time = dark time) is related to temperature by the Arrhenius equation. The temperature characteristic for 1/I(m) is different above and below 20 degrees C. In each range (12 degrees to 20 degrees ; 20 degrees to 30 degrees ) the temperature characteristic is the same for rod and cone segments of the duplex flicker response contour: 8,200 and 14,400. This makes it difficult, if not impossible, to consider that the two groups of elements are organized in a significantly different way chemically. For the presumptively rod-connected elements implicated in response to flicker, the curve is markedly discontinuous, so that the high and low temperature parts are dislocated; whereas for the cones they are not. This is entirely consistent with other (e.g., genetic) evidence pointing to their separate physical substrata. The uncommon exhibition of a higher micro over a higher range of temperature, previously found, however, in a few cases, together with the different relations of rod and cone effects to the critical temperature, explain aspects of these data which in earlier incomplete measurements were found to be puzzling. PMID- 19873117 TI - THE KINETICS OF PENETRATION : XVI. THE ACCUMULATION OF AMMONIA IN LIGHT AND DARKNESS. AB - The accumulation of ammonia takes place more rapidly in light than in darkness. The accumulation appears to go on until a steady state is attained. The steady state concentration of ammonia in the sap is about twice as great in light as in darkness. Both effects are possibly due to the fact that the external pH (and hence the concentration of undissociated ammonia) outside is raised by photosynthesis. Certain "permeability constants" have been calculated. These indicate that the rate is proportional to the concentration gradient across the protoplasm of NH(4)X which is formed by the interaction of NH(3) or NH(4)OH and HX, an acid elaborated in the protoplasm. The results are interpreted to mean that HX is produced only at the sap-protoplasm interface and that on the average its concentration there is about 7 times as great as at the sea water-protoplasm interface. This ratio of HX at the two surfaces also explains why the concentration of undissociated ammonia in the steady state is about 7 times as great in the sea water as in the sap. The permeability constant P''' appears to be greater in the dark. This is possibly associated with an increase in the concentration of HX at both interfaces, the ratio at the two surfaces, however, remaining about the same. The pH of sap has been determined by a new method which avoids the loss of gas (CO(2)), an important source of error. The results indicate that the pH rises during accumulation but the extent of this rise is smaller than has hitherto been supposed. As in previous experiments, the entering ammonia displaced a practically equivalent amount of potassium from the sap and the sodium concentration remained fairly constant. It seems probable that the pH increase is due to the entrance of small amounts of NH(3) or NH(4)OH in excess of the potassium lost as a base. PMID- 19873118 TI - THE KINETICS OF PENETRATION : XVII. THE EXIT OF AMMONIA IN LIGHT AND DARKNESS. AB - The exit of accumulated ammonia from the sap of Valonia macrophysa, Kutz., into normal (nearly ammonia-free) sea water, has been studied in light (alternation of daylight and darkness) and in darkness. Exit is always preceded by an induction period lasting 1 or more days. This is longer in darkness. After exit starts the rate is greater in light than in darkness. The pH of the sap drops off soon after the cells are exposed to normal sea water even before any definite decrease in the ammonia concentration of the sap has occurred. This suggests that the decrease in the pH is due to the loss of a very small amount of NH(3) or NH4OH without a corresponding gain of sodium as a base. In most cases sodium replaced the ammonia lost during exit, but there is some evidence that potassium may also replace ammonia. To account for the induction period it is suggested that other species than NH(4)X are concerned in the transport of ammonia, for example urea or amino acids. PMID- 19873119 TI - THE ELECTROPHORETIC MOBILITY OF RABBIT ERYTHROCYTES AND GHOSTS. AB - Measurements of the electrical mobility of washed rabbit red cells and of ghosts produced by hypotonic solutions, freezing-and-thawing, chloroform, and saponin were made in the Abramson horizontal microelectrophoresis cell. These different forms of lysis, which corresponds to a variety of degrees of injury to the red cell, are unaccompanied by any change in electrical mobility. These observations are discussed from the standpoint of the possible structure of the cell membrane and the action of lysins upon it. PMID- 19873120 TI - THE FLICKER RESPONSE CONTOUR FOR THE GECKO (ROD RETINA). AB - The flicker response contour for the gecko Sphaerodactylus (retina with only rods) agrees in all essential respects (intensity range, shape) with that for the turtle Pseudemys (cone retina), as determined under equivalent conditions with the same apparatus. With experimentally determined correction for the expansion of the iris at the very lowest intensities, the F - log I contour for the gecko is a simple probability integral. Its maximum F is lower than that for other animals; this means simply a smaller number of available sensory elements. The quantitative parallelism in the magnitudes of the intensities at the inflection of F - log I and the shape constants for rod and cone animals show that assumptions from comparative histological evidence concerning the properties of rods and cones in relation to visual performance may be quite misleading. PMID- 19873121 TI - THE ELECTRICAL IMPEDANCE OF MUSCLE DURING THE ACTION OF NARCOTICS AND OTHER AGENTS. AB - 1. The effect of certain inorganic cations upon the electrical impedance of the sartorius muscle of the frog was investigated. While Na, K, and Mg have little effect upon the resistance of muscle, Ba and Ca cause it to fall. The use of physiologically "unbalanced" salt solution does not in itself seem to affect muscle impedance. 2. The time course of the effect upon muscle impedance of the penetration of substances into the intercellular spaces was studied by treating the muscle with sugar solutions. Half of the effect is over in three-quarters of a minute when the sugar solution is permitted to circulate past both sides of the muscle. This sets an upper limit for the time necessary for inorganic cations and organic narcotics to reach the cell surfaces. The action of inorganic cations and organic narcotics upon muscle is slow compared to the time necessary for them to reach the scene of action. The penetration of the sugar solutions into the intercellular spaces of muscle was found to follow the well known diffusion law, the amount diffusing in being proportional to the square root of the time. Average values of 77.7 per cent for rho, the volume concentration of fibers; 231 ohms specific resistance for r(2), the resistance of the interior of the fibers; and 71.0 degrees for theta, the phase angle of the impedance locus, were obtained for the muscle in Ringer's solution. How these values change when the muscle is placed in various concentrations of sugar was also studied. 3. The action of a number of organic narcotics upon muscle was studied. All decrease 1000 cycle resistance if the concentration is sufficiently high. A detailed analysis of the action of the narcotic, iso-amyl carbamate, was made, and it was noted that low concentrations increase resistance while higher concentrations decrease it. By investigating the effect of narcotics upon muscle impedance over a wide frequency range, it was found that during narcosis the resistance of the fiber membranes first increases and then decreases, and, if the drug is present in sufficiently great concentration, membrane resistance may completely disappear. Membrane capacity is only very slightly affected. PMID- 19873122 TI - THE VISIBILITY OF SINGLE LINES AT VARIOUS ILLUMINATIONS AND THE RETINAL BASIS OF VISUAL RESOLUTION. AB - The visual resolution of a single opaque line against an evenly illuminated background has been studied over a large range of background brightness. It was found that the visual angle occupied by the thickness of the line when it is just resolved varies from about 10 minutes at the lowest illuminations to 0.5 second at the highest illuminations, a range of 1200 to 1. The relation between background brightness and just resolvable visual angle shows two sections similar to those found in other visual functions; the data at low light intensities represent rod vision while those at the higher intensities represent cone vision. With violet light instead of white the two sections become even more clearly defined and separated. The retinal image produced by the finest perceptible line at the highest brightness is not a sharp narrow shadow, but a thin broad shadow whose density distribution is described in terms of diffraction optics. The line of foveal cones occupying the center of this shadow suffers a decrease in the light intensity by very nearly 1 per cent in comparison either with the general retinal illumination or with that on the row of cones to either side of the central row. Since this percentage difference is near the limit of intensity discrimination by the retina, its retinal recognition is probably the limiting factor in the visual resolution of the line. The resolution of a line at any light intensity may also be limited by the just recognizable intensity difference, because this percentage difference varies with the prevailing light intensity. As evidence for this it is found that the just resolvable visual angle varies with the light intensity in the same way that the power of intensity discrimination of the eye varies with light intensity. It is possible that visual resolution of test objects like hooks and broken circles is determined by the recognition of intensity differences in their diffracted images, since the way in which their resolution varies with the light intensity is similar to the relation between intensity discrimination and light intensity. PMID- 19873123 TI - THE CHLOROPHYLL-CARBON DIOXIDE RATIO DURING PHOTOSYNTHESIS. AB - Using a rapid spectrographic method of carbon dioxide measurement previously described by McAlister (1937) further studies on the time course of photosynthesis in the higher plant, wheat, variety Marquis, are herein reported. Of major importance in this work is the discovery of a pick-up of carbon dioxide in darkness immediately following a high rate of photosynthesis (see Figs. 3 and 4). This pick-up is believed to be due to the action of a carbon dioxide combining intermediate; i.e., the "acceptor molecule" for carbon dioxide in photosynthesis. The conditions under which this phenomenon has so far been observed indicate that the intermediate is formed in relatively large quantities during the actual process of photosynthesis and not before. That the intermediate is chlorophyllous in nature is suggested by a simple stoichiometry of the order of unity that is found to exist between the number of carbon dioxide molecules taken up and the total number of chlorophyll molecules present in the plant. This is in opposition to the idea of a large photosynthetic unit of some 2000 chlorophyll molecules operating together in the reduction of 1 carbon dioxide molecule. Further studies of the induction phase under various conditions of previous dark rest and of carbon dioxide and light limitation are herein described. Employing the simple hypothesis that the number of carbon dioxide molecules not reduced during the induction period (induction loss) gives a measure of the number of elementary photosynthetic cycles unoperative or compensated for during induction together with the experimental fact that this induction loss is of the order of the total number of chlorophyll molecules present, these latter studies also indicate, in a less direct manner, that chlorophyll participates in photosynthesis as an individual molecule and not as part of a very large multimolecular chlorophyll unit. The fast dark reaction lasting about 1 minute (Fig. 7) required to reproduce both (a) the phenomena of induction in carbon dioxide assimilation and (b) the recovery of fluorescence of chlorophyll in leaves in darkness as observed by Franck and Wood (1936), demonstrates a close relationship between the fluorescence of chlorophyll and induction in photosynthesis. The rate of respiration (carbon dioxide production) of the higher plant, wheat, was measured under intense illumination and in the absence of carbon dioxide (to suppress assimilation). This value was found to be identical with the dark respirational rate measured before and after the light period, indicating very positively the absence of any direct effect of light on respiration. PMID- 19873124 TI - THE EFFECTS OF PANTOTHENIC ACID ON RESPIRATORY ACTIVITY. AB - Experiments using the Warburg-Barcroft apparatus led to the following results and conclusions: (1) Two yeasts in three different media were strikingly stimulated in their respiration by minute amounts of pantothenic acid. (2) Nine other compounds (vitamins and other biologically important substances) were tested and found in all cases to have on the deficient G.M. yeast, lesser and in some cases no appreciable stimulative effect. Thiamin was the most effective of these compounds. Its action was shown to be different and in some ways antagonistic to that of pantothenic acid. (3) Liver extract (Lilly's Number 343) contains substances capable of speeding up respiration (and growth) to a much higher level than seems possible with known compounds. (4) Pantothenic acid was found to have a definite stimulative effect on fermentation by dialyzed maceration juice from yeast. (5) It likewise stimulated respiration of apple and potato tissue and indications of a similar effect on certain animal tissues were obtained. PMID- 19873125 TI - ELECTRIC IMPEDANCE OF THE SQUID GIANT AXON DURING ACTIVITY. AB - Alternating current impedance measurements have been made over a wide frequency range on the giant axon from the stellar nerve of the squid, Loligo pealii, during the passage of a nerve impulse. The transverse impedance was measured between narrow electrodes on either side of the axon with a Wheatstone bridge having an amplifier and cathode ray oscillograph for detector. When the bridge was balanced, the resting axon gave a narrow line on the oscillograph screen as a sweep circuit moved the spot across. As an impulse passed between impedance electrodes after the axon had been stimulated at one end, the oscillograph line first broadened into a band, indicating a bridge unbalance, and then narrowed down to balance during recovery. From measurements made during the passage of the impulse and appropriate analysis, it was found that the membrane phase angle was unchanged, the membrane capacity decreased about 2 per cent, while the membrane conductance fell from a resting value of 1000 ohm cm.(2) to an average of 25 ohm cm.(2) The onset of the resistance change occurs somewhat after the start of the monophasic action potential, but coincides quite closely with the point of inflection on the rising phase, where the membrane current reverses in direction, corresponding to a decrease in the membrane electromotive force. This E.M.F. and the conductance are closely associated properties of the membrane, and their sudden changes constitute, or are due to, the activity which is responsible for the all-or-none law and the initiation and propagation of the nerve impulse. These results correspond to those previously found for Nitella and lead us to expect similar phenomena in other nerve fibers. PMID- 19873126 TI - MEMBRANE AND PROTOPLASM RESISTANCE IN THE SQUID GIANT AXON. AB - The direct current longitudinal resistance of the squid giant axon was measured as a function of the electrode separation. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The slope of the resistance vs. separation curve is large for a small electrode separation, but becomes smaller and finally constant as the separation is increased. An analysis of the resistance vs. length curves gives the following results. The nerve membrane has a resistance of about 1000 ohm cm.(2) The protoplasm has a specific resistance of about 1.4 times that of sea water. The resistance of the connective tissue sheath outside the fiber corresponds to a layer of sea water about 20micro in thickness. The characteristic length for the axon is about 2.3 mm. in oil and 6.0 mm. in sea water. PMID- 19873127 TI - THE EFFECTS OF ULTRAVIOLET RADIATION ON SPORES OF THE FUNGUS ASPERGILLUS NIGER. AB - The survival ratio of Aspergillus spores exposed to ultraviolet radiation has been measured as a function of total incident energy for wave lengths of 2537 A, 3022 A, 3129 A, and 3650 A. The effect of humidity on killing of Aspergillus spores by ultraviolet radiation has been found to be negligible. A delay in germination as a result of irradiation has been found. The Bunsen-Roscoe reciprocity law has been found to hold within the limits of the radiation intensities studied. Certain morphological changes have been observed. PMID- 19873128 TI - INTRACELLULAR PHAGE PRECURSOR. AB - 1. Staphylococci activated by rapid growth in the presence of excess O(2) and subsequently brought to a resting state by storage in Locke's solution at 5 degrees C. produce a significant rise in [phage] when added to phage-containing solutions. 2. For satisfactory activation the staphylococci require a period of active growth in the presence of oxygen. Activation proceeds best on the acid side of neutrality although variation in pH from 5 to 9 has relatively little effect. Activated cells retain their phage-augmenting property for from 4 to 24 hours, and this property may be destroyed by heating the cells at temperatures which do not kill them. The critical thermal increment for heat inactivation is 90,000 suggesting that the reaction involves protein denaturation. 3. The reaction between activated cells and phage has the following characteristics: A. It is complete in 1 to 2 minutes after mixing the reactants. B. The increase in phage does not depend upon bacterial growth nor does it involve any untoward effect on the titration system. C. Serum prepared by injecting rabbits with normal live staphylococci or with activated staphylococci when mixed with activated cells before the addition of phage will prevent the customary increase in [phage]. 4. The phage-producing reaction which follows the addition of activated cells to phage can be interpreted in terms of the precursor theory. It is likely that the precursor either is a protein or contains a protein as an essential component. 5. There is no way of deciding at present whether the reaction between phage and precursor represents the hydrolytic cleavage of a protein or whether it is the final step in a synthesis catalyzed by phage. PMID- 19873129 TI - TEMPERATURE ACTIVATION OF THE UREASE-UREA SYSTEM USING CRUDE AND CRYSTALLINE UREASE. AB - 1. The hydrolysis of urea catalyzed by jack bean meal has been followed by determining colorimetrically after Nesslerization the ammonia nitrogen, and volumetrically the carbon dioxide liberated at successive intervals during the reaction. During the early part of hydrolysis the rate of ammonia or carbon dioxide liberation is constant for all the urease solutions which were used. 2. When log rate of NH(3) or CO(2) formation was plotted against 1/T, the points fell along a straight line, the slope of which corresponded to an activation energy of either 8,700 or 11,700 calories per gram mol. Frequently urease, when dissolved in sulfite solution, was characterized by an activation energy of 11,700 below and 8,700 above the critical temperature of about 23 degrees C. At high temperatures the plotted points fell off from the curve due to temperature inactivation. 3. Essentially the same results on temperature activation were obtained with crude jack bean meal, Arlco urease, crystalline urease not recrystallized, and crystalline urease once recrystallized. The temperature characteristic which was obtained depended in part upon the composition of the medium. When dissolved in water, or aqueous solutions of glycerine, KCN, Na(2)S(2)O(2), cystine, Na(2)SO(4), and K(4)Fe(CN)(6), the temperature characteristic or micro of urease is 8,700. On the other hand, when urease is dissolved in solutions of K(3)Fe(CN)(6) or H(2)O(2) the micro value is 11,700. When dissolved in a solution containing Na(2)SO(3) and NaHSO(3) the micro value may be either 8,700 or 11,700 over the whole temperature range, or 11,700 below and 8,700 above 23 degrees C. 4. When crystalline urease is dissolved in varying mixtures of K(4)Fe(CN)(6) and K(3)Fe(CN)(6), the temperature characteristic depends upon the oxidation-reduction potential of the digest. When E(h) is greater than +0.46 volt micro = 11,700, when less than +0.42 volt micro = 8,700, when between +0.42 - +0.46 micro = 11,700 below and 8,700 above the critical temperature. 5. It is suggested that in reducing or in indifferent solutions the configuration of the urease molecule (as determined especially by SH groups present) is such that the activation energy is 8,700 calories. In oxidizing solutions the urease molecule has been so altered (perhaps by the oxidation of the SH groups) as to be partly inactivated and now has an activation energy of 11,700. Such changes in the urease molecule are reversible (unless oxidation has proceeded too far) and are accompanied by a corresponding change in the activation energy. PMID- 19873130 TI - THE KINETICS OF PENETRATION : XVIII. ENTRANCE OF WATER INTO IMPALED HALICYSTIS. AB - The rate of entrance of water into impaled cells of Halicystis Osterhoutii, Blinks and Blinks, has been determined directly by measurements of the rise of sap in a capillary for dilute sea waters (containing between 90 and 30 per cent sea water). The velocity constant remains reasonably constant down to 50 per cent sea water but it decreases markedly in lower concentrations. PMID- 19873131 TI - THE KINETICS OF PENETRATION : XIX. ENTRANCE OF ELECTROLYTES AND OF WATER INTO IMPALED HALICYSTIS. AB - When cells of Halicystis are impaled on a capillary so that space is provided into which the sap can migrate, the rate of entrance of water and of electrolyte is increased about 10-fold. In impaled Valonia cells the rate is increased about 15-fold. After a relatively rapid non-linear rate of increase of sap volume immediately after impalement (which may possibly represent the partial dissipation of the difference of the osmotic energy between intact and impaled cells) the volume increases at a linear rate, apparently indefinitely. Since the halide concentration of the sap at the end of the experiment is (within the limits of natural variation) the same as in the intact cell, we conclude that electrolyte also enters the sap about 10 times as fast as in the intact cell. As in the case of Valonia we conclude that there is a mechanism whereby in the intact cell the osmotic concentration of the sap is prevented from greatly exceeding that of the sea water. This may be associated with the state of hydration of the non-aqueous protoplasmic surfaces. PMID- 19873132 TI - THE PORPHYROPSIN VISUAL SYSTEM. AB - 1. In the rods of fresh-water and some anadromous fishes, rhodopsin is replaced by the purple photolabile pigment porphyropsin. This participates in a retinal cycle identical in form with that of rhodopsin, but in which new carotenoids replace retinene and vitamin A. 2. Porphyropsin possesses a broad absorption maximum at 522 +/- 2 mmicro, and perhaps a minimum at about 430 mmicro. The vitamin A-analogue, vitamin A(2), possesses a maximum in chloroform at 355 mmicro and yields with antimony trichloride a deep blue color due to a band at 696 mmicro. The retinene-analogue, retinene(2), absorbs maximally in chloroform at 405 mmicro and possesses an antimony chloride maximum at 706 mmicro. 3. Its non diffusibility through a semi-permeable membrane, salting-out properties, and sensitivity to chemical denaturants and to heat, characterize porphyropsin as a conjugated carotenoid-protein. 4. The porphyropsin cycle may be formulated: porphyropsin See PDF for Structure. retinene(2)-protein ((2)) (-->) vitamin A(2) protein ((3)) (-->) porphyropsin. Isolation of the retina cuts this cycle at (3); denaturation procedures or extraction of porphyropsin into aqueous solution eliminate in addition (1) and (2). 5. The primary difference between the rhodopsin and porphyropsin systems appears to be the possession by the latter of an added ethylenic group in the polyene chain. PMID- 19873133 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : IV. ANAX NYMPHS. AB - At fixed flash frequency ((F) = 20, (F) = 55) and with constant light time fraction (50 per cent) in the flash cycle, the critical illumination I for response of Anax nymphs to visual flicker falls continuously as the temperature rises. The temperature characteristic micro for the measure of excitability (1/I) increases continuously with elevation of temperature. The form of the F - log I curve does not change except at quite high temperature (35.8 degrees ), and then only slightly (near F = 55); F(max.) is not altered. The very unusual form of the 1/I curve as a function of temperature is quantitatively accounted for if two processes, with respectively micro = 19,200 and micro = 3,400, contribute independently and simultaneously to the control of the speed of the reaction governing the excitability; the velocities of these two processes are equal at 15.9 degrees . PMID- 19873134 TI - BIOELECTRIC POTENTIALS IN VALONIA : II. EFFECTS OF ARTIFICIAL SEA WATERS CONTAINING LiCl, CsCl, RbCl, OR NH(4)Cl. AB - In their influence on the P.D. across the protoplasm of Valonia macrophysa, Kutz., Li(+) and Cs(+) resemble Na(+), while Rb(+) and NH(4) (+) resemble K(+). The apparent mobilities of the ions in the external surface layer of Valonia protoplasm increase in the order: Cs(+), Na(+), Li(+) < Cl(-) < Rb(+) < K(+) < NH(4) (+). PMID- 19873135 TI - THE FLICKER RESPONSE CONTOUR FOR THE CRAYFISH. I. AB - The F - log I curve for threshold response to visual flicker has been determined for the crayfish Cambarus bartoni. As predicted on the basis of the higher curvature of the optic surface, the flicker response contour is more asymmetrical than for bee and dragonfly nymph under comparable conditions of temperature and light time fraction of flash cycle. The mechanical origin of this asymmetry is thus confirmed, and is further supported by the similar forms of the F - log I curves in bee, dragonfly larva, and crayfish in the lower portion of the curves (up to F = 70 per cent F(max.)). The slope of the fundamental curve for crayfish, deduced by analysis of the data, is lower than for bee, dragonfly nymph, or Asellus. This signifies a wider spread of the effective distribution of elemental log I thresholds involvable in the response to flicker, and may be traced either to the greater curvature of the eye-surfaces or to their position upon movable pedicles. The results are therefore consistent with the statistical conception of the nature of effects recognizable as due to the activity of excitable elements. PMID- 19873136 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : III. DeltaI AS A FUNCTION OF AREA, INTENSITY, AND WAVE-LENGTH, FOR MONOCULAR AND BINOCULAR STIMULATION. AB - Measurements of DeltaI as a function of retinal area illuminated have been obtained at various levels of standard intensity I(1), using "white" light and light of three modal wave-lengths (lambda465, 525, 680), for monocular stimulation and for simultaneous excitation of the two eyes ("binocular"), using several methods of varying (rectangular) area and retinal location, with control of exposure time. For data homogeneous with respect to method of presentation, log DeltaI(m) = -Z log A + C, where DeltaI = I(2) - I(1), A is area illuminated, and C is a terminal constant (= log DeltaI(m) for A = 1 unit) depending on the units in which DeltaI and A are expressed, and upon I(1). The equation is readily deduced on dimensional grounds, without reference to specific theories of the nature of DeltaI or of retinal area in terms of its excitable units. Z is independent of the units of I and A. Experimentally it is found to be the same for monocular and binocular excitations, as is to be expected. Also as is expected it is not independent of lambda, and it is markedly influenced by the scheme according to which A is varied; it depends directly upon the rate at which potentially excitable elements are added when A is made to increase. For simultaneous excitation of the two eyes (when of very nearly equivalent excitability), DeltaI(B) is less than for stimulation of either eye alone, at all levels of I(1), A, lambda. The mean ratio (DeltaI(L) + DeltaI(R))/2 to DeltaI(B) was 1.38. For white light, doubling A on one retina reduces DeltaI(m) in the ratio 1.21, or a little less than for binocular presentation under the same conditions. These facts are consistent with the view that the properties of DeltaI are quantitatively determined by events central to the retina. The measure sigma(1DeltaI) of organic variation in discrimination of intensities and DeltaI(m) are found to be in simple proportion, independent of I(1), A, lambda (and exposure time). Variability (sigma(1DeltaI)) is not a function of the mode of presentation, save that it may be slightly higher when both retinas are excited, and its magnitude (for a given level of DeltaI(m)) is independent of the law according to which the adjustable intensity I(2) is instrumentally controlled. PMID- 19873137 TI - FACTORS LIMITING BACTERIAL GROWTH : VI. EQUATIONS DESCRIBING THE EARLY PERIODS OF INCREASE. AB - Simple assumptions have led to equations by which the latent period in multiplication and the bacterial numbers expected at any time during the phase of rapid growth may be predicted. Experimental data obtained under rather diverse conditions have given satisfactory agreement with calculated values. Since the mathematical expressions contain no arbitrary constants, more than accidental significance must be attached to this agreement. The hypotheses set forth appear completely to describe the early development of Bacterium coli and Bacterium dysenteriae in broth, without postulating differences other than size among individual cells, or cells obtained under different conditions. PMID- 19873138 TI - REGENERATION OF VISUAL PURPLE IN SOLUTION. AB - 1. Measurements of visual purple regeneration in solution have been made by a procedure which minimized distortion of the results by other color changes so that density changes caused by the regenerating substance alone are obtained. 2. Bleaching a visual purple solution with blue and violet light causes a greater subsequent regeneration than does an equivalent bleaching with light which lacks blue and violet. This is due to a photosensitive substance which has a gradually increasing effective absorption toward the shorter wavelengths. It is uncertain whether this substance is a product of visual purple bleaching or is present in the solution before illumination. 3. The regeneration of visual purple measured at 560 mmicro is maximal at about pH 6.7 and decreases markedly at more acid and more alkaline pH's. 4. The absorption spectrum of the regenerating material shows only a concentration change during the course of regeneration, but has a higher absorption at the shorter wavelengths than has visual purple before illumination. 5. Visual purple extractions made at various temperatures show no significant difference in per cent of regeneration. 6. The kinetics of regeneration is usually that of a first order process. Successive regenerations in the same solution have the same velocity constant but form smaller total amounts of regenerated substance. 7. In vivo, the frog retina shows no additional oxygen consumption while visual purple is regenerating. PMID- 19873139 TI - THE KINETICS OF PENETRATION : XX. EFFECT OF pH AND OF LIGHT ON ABSORPTION IN IMPALED HALICYSTIS. AB - The rate of entrance of electrolyte and of water into impaled cells of Halicystis Osterhoutii is unaffected by raising the pH of the sea water to 9.2 or lowering it to 7.0. It is quite possible that sodium enters by combining with an organic acid HX produced by the protoplasm. If the pK' of this acid is sufficiently low the change in external pH would not produce much effect on the rate of entrance of sodium. The rate of entrance of electrolytes is affected by light. In normal light (i.e. natural succession of daylight and darkness) the rate is about twice as great as in darkness. PMID- 19873140 TI - CALCULATIONS OF BIOELECTRIC POTENTIALS : V. POTENTIALS IN HALICYSTIS. AB - Interest in the study of Halicystis and of Valonia has been stimulated by discoveries of marked contrasts and striking similarities existing side by side. This is illustrated by new experiments with the alkali metals and alkaline earths. In Halicystis the apparent mobilities of K(+), Rb(+), Cs(+), and Li(+) (calculated by means of Henderson's equation from changes in P.D. produced by replacing sea water by a mixture of equal parts of sea water and 0.6 M of various chlorides) are as follows, u(K), = 16, u(Rb) = 16, u(Cs) = 4.4, and u(Li) = 0.2; u(Na) is taken as 0.2. These values resemble those in Valonia except that in the latter u(Cs) is about 0.2. No calculation is made for u(NH(NH4) ), because in these experiments even at low pH so much NH(3) is present that the sign of the P.D. may reverse. This does not happen with Valonia. According to Blinks, NH(4) (+) at pH 5 in low concentrations acts like K(+). The calculation gives u(Mg) = 1.9 which is similar to the value found for Valonia. No calculation can be made for CaCl(2) since it produces protoplasmic alterations and in consequence Henderson's equation does not apply. This differs from Valonia. Evidently these plants agree closely in some aspects of electrical behavior but differ widely in others. PMID- 19873141 TI - INCREASE IN BACTERIOPHAGE AND GELATINASE CONCENTRATION IN CULTURES OF BACILLUS MEGATHERIUM. AB - 1. The increase in bacteria, phage concentration, and gelatinase concentration in cultures of B. megatherium has been determined. 2. With lysogenic cultures the phage concentration, gelatinase concentration, and bacteria concentration increase logarithmically at first. The phage and gelatinase concentration then decrease while the bacteria concentration increases to a maximum. 3. The results are the same with sensitive cultures if the ratio of phage to bacteria is small. If the ratio of phage to bacteria is large phage, gelatinase, and bacteria concentration all increase at first and then decrease. The maximum rate of increase coincides approximately with the maximum rate of oxygen consumption of the culture. 4. 60-90 per cent of the phage is free from the cells. 5. The amount of phage produced is determined by the combined phage and not by the total phage. 6. Phage is produced during growth of the cells and not during lysis. 7. In a very narrow range of pH near 5.55 no increase in bacteria occurs but large increases in phage may be obtained. PMID- 19873142 TI - CHEMICAL PACEMAKERS : PART I. CATALYTIC BRAIN IRON. PART II. ACTIVATION ENERGIES OF CHEMICAL PACEMAKERS. AB - 1. Iron spicules found in the brains of general paretic patients are formed from endogenous brain iron normally present in another form. This supports our earlier view that the micro value of 16,000 obtained in advanced paretics for alpha brain wave frequencies as a measure of cortical respiration comes about from the slowing of an iron catalyzed link in cortical respiration such as would result from the reduction of available cytochrome and its oxidase, thus making this step a chemical pacemaker. 2. To test the basic theory of chemical pacemakers, a study was made of the succinate-fumarate enzyme system containing succino-dehydrogenase and cytochrome-cytochrome oxidase acting sequentially. 3. The micro value for the unpoisoned system is 11,200 +/- 200 calories. 4. According to theory, the addition of a critical amount of cyanide known to be a specific poison of the cytochrome-cytochrome oxidase system (and not of the dehydrogenase) should shift the micro cleanly to 16,000 calories, and it does. 5. According to theory, selenite, a specific poison for the dehydrogenase, should stop all respiration without shifting the micro. This also is found to be the case. 6. The theory also predicts that if the micro is shifted from 11,000 +/- to 16,000 +/- by cyanide, the subsequent addition of a critical amount of selenite should shift the micro back again to 11,000 +/- calories, and this is found to occur. 7. It is concluded that approximately 11,000 calories is the energy of activation of the succino dehydrogenase-catalyzed step and 16,000 calories is that for the cytochrome cytochrome oxidase-catalyzed step. These two values are encountered more frequently than any others in physiological systems. It is to be recalled that a shift of micro for alpha brain wave frequencies from 11,000 to 16,000 calories occurs in the course of advancing syphilitic brain infection and is accompanied by a change in form of brain iron. PMID- 19873143 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : V. XIPHOPHORUS, PLATYPOECILIUS, AND THEIR HYBRIDS. AB - For the teleosts Xiphophorus montezuma, Platypoecilius maculatus, and their F(1) hybrids the temperature characteristics (micro in Arrhenius' equation) are the same for the shift of the low intensity and the high intensity segments of the respective and different flicker response contours (critical intensity I as a function of flash frequency F, with light time fraction constant, at 50 per cent). The value of micro is 12,500 calories or a very little less, over the range 12.5 to 36 degrees . This shows that 1/I can be understood as a measure of excitability, with F fixed, and that the excitability is governed by the velocity of a chemical process common to both the classes of elements represented in the duplex performance curve (rods and cones). It is accordingly illegitimate to assume that the different shapes of the rod and cone branches of the curves are determined by differences in the chemical mechanisms of excitability. It is also forbidden to assume that the differing form constants for the homologous segments in the curves for two forms (X. and P.) are the reflections of a difference in the chemical factors of primary excitability. These differences are determined by statistical factors of the distribution of excitabilities among the elements implicated in the sensory effect vs. intensity function, and are independent of temperature and of the temperature characteristic. It must be concluded that the physicochemical nature of the excitatory process cannot be deduced from the shape of the performance contour. The form constants (sigma'(log I) and F(max.)) for F vs. log I are specifically heritable in F(1), although micro is here the same as for X. and P. In an intergeneric cross one cannot in general expect Mendelian simplicity of segregation in subsequent generations, and in the present case we find that F(2) individuals are indistinguishable from F(1), both as regards F vs. log I and as regards the variation of I within a group of 17 individuals. The result in F(2) definitely shows, however, that certain specific statistical form constants for the F-log I contour are transmissible in inheritance. It is pointed out that there thus is provided an instance in which statistical (distribution) factors in performance characteristics involving the summating properties of assemblages of cellular units are heritable in a simple manner without the implication of detectable differences in chemical organization of the units involved. This has an important bearing upon the logic of the theory of the gene. PMID- 19873144 TI - THE CHEMISTRY OF HUMAN SKIN : IV. THE ELECTROKINETIC EFFECT OF VARIOUS IONS UPON SUSPENDED PARTICLES OF STRATUM CORNEUM. AB - 1. The electrophoretic activity of particles of human skin in distilled water and different concentrations of salt solutions has been studied. The electrokinetic potential and the charge density were determined and comparisons made with results obtained by electroendosmosis. 2. The electrokinetic potential is ultimately decreased if sufficient salt is added. The order of inhibition is Al > Ca > Ba > K > Na. 3. The lyotrophic series Li > Na > K > Rb and Cl > I > Br express respectively the comparative effect of the monovalent cations and anions upon the electrokinetic potential of the skin. 4. Since both electrophoresis and electroendosmosis are dependent upon the electrokinetic potential, it follows from the results obtained, that the greatest rate of flow through the human skin under the force of an applied electrical current would be given by concentrations of neutral salts between 0.0001 M and 0.0002 M. PMID- 19873145 TI - CALCULATIONS OF BIOELECTRIC POTENTIALS : VI. SOME EFFECTS OF GUAIACOL ON NITELLA. AB - Values have been calculated for apparent mobilities and partition coefficients in the outer non-aqueous layer of the protoplasm of Nitella. Among the alkali metals (with the exception of cesium) the order of mobilities resembles that in water and the partition coefficients (except for cesium) follow the rule of Shedlovsky and Uhlig, according to which the partition coefficient increases with the ionic radius. Taking the mobility of the chloride ion as unity, we obtain the following: lithium 2.04, sodium 2.33, potassium 8.76, rubidium 8.76, cesium 1.72, ammonium 4.05, (1/2) magnesium 20.7, and (1/2) calcium 7.52. After exposure to guaiacol these values become: lithium 5.83, sodium 7.30, potassium 8.76, rubidium 8,76, cesium 3.38, ammonium 4.91, (1/2) magnesium 20.7, and (1/2) calcium 14.46. The partition coefficients of the chlorides are as follows, when that of potassium chloride is taken as unity: lithium 0.0133, sodium 0.0263, rubidium 1.0, cesium 0.0152, ammonium 0.0182, magnesium 0.0017, and calcium 0.02. These are raised by guaiacol to the following: lithium 0.149, sodium 0.426, rubidium 1.0, cesium 0.82, ammonium 0.935, magnesium 0.0263, and calcium 0.323 (that of potassium is not changed). The effect of guaiacol on the mobilities of the sodium and potassium ions resembles that seen in Halicystis but differs from that found in Valonia where guaiacol increases the mobility of the sodium ion but decreases that of the potassium ion. PMID- 19873146 TI - PERFORMANCE OF THE HEPP MICRO-OSMOMETER. AB - Estimation of the molecular weight of horse serum albumin from the osmotic pressure of solutions containing 0.713 to 5.12 gm. per 100 cc. shows that the Hepp osmometer yields the same values as the standard simple osmometer of Adair. Accuracy and precision of the instrument decrease noticeably at concentrations of albumin less than 0.7 gm. per 100 cc. A determination in duplicate can be carried out with this instrument in less than 2 hours. The instrument is easily operated. PMID- 19873147 TI - STUDIES CONCERNING THE NATURE OF THE SECRETORY ACTIVITY OF THE ISOLATED RINGER PERFUSED FROG LIVER : I. THE DIFFERENTIAL SECRETION OF PAIRS OF DYESTUFFS. AB - The isolated Ringer-perfused frog liver is able to concentrate in its secretion several hundred or even thousand times a great number of dyestuffs. When two dyestuffs are perfused simultaneously, the liver separates them to a lower or higher degree, some times to such an extent that the secretion of one of them is entirely suppressed by the other. Which one of the two dyestuffs appears prevailingly in the secretion, does not depend upon its diffusibility or lipoid solubility, but perhaps upon its adsorbability. This is concluded from the fact that dyestuffs provided with several (4 to 5) strongly hydrophilic sulfonate groups in their molecule, are not permitted to pass the gland. PMID- 19873148 TI - STUDIES CONCERNING THE NATURE OF THE SECRETORY ACTIVITY OF THE ISOLATED RINGER PERFUSED FROG LIVER : II. THE INHIBITORY AND THE PROMOTING INFLUENCE OF ORGANIC ELECTROLYTES AND NON-ELECTROLYTES UPON THE SECRETION OF DYESTUFFS. AB - The ability of the isolated Ringer-perfused frog liver, to concentrate dyestuffs in its secretion several hundred times, can be abolished entirely and reversibly by replacing in the Ringer solution about 1/8 of the NaCl by the isosmotic amount of a surface-inactive non-electrolyte (disaccharide, hexose, pentose, polyhydric alcohol, amino acid, acid amide) or electrolyte (salts of lower fatty acids, hydroxyl carboxylic, and dicarboxylic acids). This effect is not dependent upon changes in the perfusion rate. The opposite effect, promotion of secretory activity, can be brought about by polar-non-polar electrolytes (salts of higher fatty acids, bile acids, and other aromatic carboxylic acids, aromatic sulfonic acids) and surface-active non-electrolytes (anesthetics, alkaloids, digitonin). However, reversibility of this effect cannot be regularly observed, since cytolysis is frequently the end result. Suitable concentrations of inhibitory and promoting substances, simultaneously applied, counteract each other. Inhibitory and promoting substances, in general, exhibit opposite effects upon the dispersion of colloids (starch, lecithin, gelatin). The correlation between the physicochemical and the physiological action of the organic compounds is discussed. PMID- 19873149 TI - STUDIES ON THE PURIFICATION OF BACTERIOPHAGE. AB - A simple method of concentrating and purifying bacteriophage has been described. The procedure consisted essentially in collecting the active agent on a reinforced collodion membrane of a porosity that would just retain all the active agent and permit extraneous material to pass through. Advantage was taken of the fact that B. coli will proliferate and regenerate bacteriophage in a completely diffusible synthetic medium with ammonia as the only source of nitrogen, which permitted the purification of the bacteriophage by copious washing. The material thus obtained was concentrated by suction and after thorough washing possessed all the activity of the original filtrate. It was labile, losing its activity in a few days on standing, and was quickly and completely inactivated upon drying. This material contained approximately 15 per cent of nitrogen and with 2 or 3 mg. samples of inactive dry residue it was possible to obtain positive protein color tests. The concentrated and purified bacteriophage has about 10(-14) mg. of nitrogen, or 6 x 10(-17) gm. of protein per unit of lytic activity. Assuming that each unit of activity represents a molecule, the calculated maximum average molecular weight would be approximately 36,000,000, and on the assumption of a spherical shape of particles and a density of 1.3, the calculated radius would be about 22 millimicra. By measurement of the diffusion rate, the average radius of particle of the fraction of the purified bacteriophage which diffuses most readily through a porous plate was found to be of the order of magnitude of 9 millimicra, or of a calculated molecular weight of 2,250,000. Furthermore, when this purified bacteriophage was fractionated by forcing it through a thin collodion membrane, which permits the passage of only the smaller particles, it was possible to demonstrate in the ultrafiltrate active particles of about 2 millimicra in radius, and of a calculated molecular weight of 25,000. It was of interest to apply this method of purification to a staphylococcus bacteriophage. Since this organism does not readily grow in synthetic medium, a diffusate of yeast extract medium was employed. The better of two preparations contained about 10(-12) mg. of nitrogen per unit of lytic activity. Although this is about one hundred times the amount of nitrogen found in an active unit of B. coli bacteriophage, nevertheless, the diffusion rate experiments gave results which paralleled those obtained with the coliphage. The diffusible particles of the crude staphylococcus bacteriophage had a radius of about 7 millimicra, and a calculated molecular weight of about 1,000,000, while the particles of the same phage which appeared in the ultrafiltrate through a thin collodion membrane had a radius of about 2.4 millimicra and a calculated molecular weight of about 45,000. It appears, therefore, that the active principle is distributed as particles of widely different sizes. However, since the smaller particles have all the properties of bacteriophage, the larger particles probably do not represent free molecules, but either are aggregates, or more likely, inactive colloids to which the active agent is adsorbed. The protein isolated, which bears the phage activity, is capable of stimulating the production of antilytic antibodies on parenteral injection into rabbits or guinea pigs. It retains its specific antigenicity when inactivated by formalin, but not when inactivated by drying. PMID- 19873150 TI - THE FLICKER RESPONSE CONTOUR FOR THE FROG. AB - The flicker response contour for the frog Rana pipiens exhibits the duplex character typical for most vertebrates. By comparison (under the same conditions of temperature, 21.5 degrees , and light-time fraction, = 0.5), the low intensity section of the F - log I curve is the smallest thus far found. The cone portion of the curve is satisfactorily described by a probability integral. The rod part represents the addition of a small group of sensory effects upon the lower end of the cone curve, from which it can be analytically separated. The relation between the two groups of sensory effects permits certain tests of the rule according to which (in homogeneous data) I(m) and sigma(1I1) are in direct proportion. PMID- 19873151 TI - THE DENATURATION OF PROTEINS BY SYNTHETIC DETERGENTS AND BILE SALTS. PMID- 19873152 TI - THE REACTIONS OF DENATURED EGG ALBUMIN WITH FERRICYANIDE. AB - The following facts have been established experimentally. 1. In the presence of the synthetic detergent, Duponol PC, there is a definite reaction between dilute ferricyanide and denatured egg albumin. 0.001 mM of ferrocyanide is formed by the oxidation of 10 mg. of denatured egg albumin despite considerable variation in the time, temperature, and pH of the reaction and in the concentration of ferricyanide. 2. If the concentration of ferricyanide is sufficiently high, then the reaction between ferricyanide and denatured egg albumin in Duponol solution is indefinite. More ferrocyanide is formed the longer the time of reaction, the higher the temperature, the more alkaline the solution, and the higher the concentration of ferricyanide. 3. Denatured egg albumin which has been treated with formaldehyde or iodoacetamide, both of which abolish the SH groups of cysteine, does not reduce dilute ferricyanide in Duponol PC solution. 4. Cysteine is the only amino acid which is known to have a definite reaction with ferricyanide or which is known to react with dilute ferricyanide at all. The cysteine-free proteins which have been tried do not reduce dilute ferricyanide in Duponol PC solution. 5. Concentrated ferricyanide oxidizes cystine, tyrosine, and tryptophane and proteins which contain these amino acids but not cysteine. The reactions are indefinite, more ferrocyanide being formed, the higher the temperature and the concentration of ferricyanide. 6. The amount of ferrocyanide formed from denatured egg albumin and a given amount of ferricyanide is less in the absence than in the presence of Duponol PC. 7. The amount of ferrocyanide formed when denatured egg albumin reacts with ferricyanide in the absence of Duponol PC depends on the temperature and ferricyanide concentration throughout the whole range of ferricyanide concentrations, even in the low range of ferricyanide concentrations in which ferricyanide does not react with amino adds other than cysteine. The foregoing results have led to the following conclusions which, however, have not been definitely proven. 1. The definite reaction between denatured egg albumin in Duponol PC solution and dilute ferricyanide is a reaction with SH groups whereas the indefinite reactions with concentrated ferricyanide involve other groups. 2. The SH groups of denatured egg albumin in the absence of Duponol PC react with iodoacetamide and concentrated ferricyanide but they do not all react rapidly with dilute ferricyanide. 3. Duponol PC lowers the ferricyanide concentration at which the SH groups of denatured egg albumin react with ferricyanide. The SH groups of denatured egg albumin, however, are free and accessible even in the absence of Duponol PC. PMID- 19873153 TI - ON THE PERMEABILITY OF THE STOMACH MUCOSA FOR ACIDS AND SOME OTHER SUBSTANCES. AB - 1. Solutions approximately isotonic with blood of strong and weak acids, several salts, glucose, and glycine were introduced in the resting stomachs of cats. The concentration and volume changes were recorded. 2. It was found that the stomach mucosa was permeable to the majority of the ions tested. There was also a permeability in the opposite direction from the blood (mucosa) to the stomach content, particularly of alkali chlorides. Poorly permeable substances were glucose, glycine, and sodium iodate. Pure weak acids such as acetic acid penetrated very rapidly. 3. The electrolyte concentration changes in the stomach content (or gastric juice) are pictured as an exchange diffusion; for instance, the hydrogen ions of an acid are exchanged against alkali ions of the mucosa or blood. 4. It is pointed out that the concept of the mucosa as an ion permeable membrane could be used as the foundation of a "diffusion theory," which can explain the acidity and chloride variations of the gastric juice without postulating neutralizing or diluting secretions. PMID- 19873154 TI - PHYSICOCHEMICAL PROPERTIES OF THE PROTEOLYTIC ENZYME FROM THE LATEX OF THE MILKWEED, ASCLEPIAS SPECIOSA TORR. SOME COMPARISONS WITH OTHER PROTEASES : I. CHEMICAL PROPERTIES, ACTIVATION-INHIBITION, pH-ACTIVITY, AND TEMPERATURE-ACTIVITY CURVES. AB - 1. A study has been made of the properties of a hitherto unreported proteolytic enzyme from the latex of the milkweed, Asclepias speciosa. The new protease has been named asclepain by the authors. 2. The results of chemical, diffusion, and denaturation tests indicate that asclepain is a protein. 3. Like papain, asclepain dots milk and digests most proteins, particularly if they are dissolved in concentrated urea solution. Unlike papain, asclepain did not clot blood. 4. The activation and inhibition phenomena of asclepain resemble those of papain, and seem best explained on the assumption that free sulfhydryl in the enzyme is necessary for proteolytic activity. The sulfhydryl of asclepain appears more labile than that of papain. 5. The measurement of pH-activity curves of asclepain on casein, ovalbumin, hemoglobin, edestin, and ovovitellin showed no definite digestion maxima for most of the undenatured proteins, while in urea solution there were well defined maxima near pH 7.0. Native hemoglobin and ovovitellin were especially undigestible, while native casein was rapidly attacked. 6. Temperature-activity curves were determined for asclepain on hemoglobin, casein, and milk solutions. The optimum temperature was shown to increase with decreasing time of digestion. PMID- 19873155 TI - PHYSICOCHEMICAL PROPERTIES OF THE PROTEOLYTIC ENZYME FROM THE LATEX OF THE MILKWEED, ASCLEPIAS SPECIOSA TORR. SOME COMPARISONS WITH OTHER PROTEASES : II. KINETICS OF PROTEIN DIGESTION BY ASCLEPAIN. AB - 1. The kinetics of milk clotting by asclepain, the protease of Asclepias speciosa, were investigated. At higher concentrations of enzyme, the clotting time was inversely proportional to the enzyme concentration. 2. The digestion of casein and hemoglobin in 6.6 M urea by asclepain follows the second order reaction rate. The rate was roughly second order for casein in water. 3. Evaluation of the nature of the enzyme-substrate intermediate indicates that one molecule of asclepain combines with one molecule of casein or hemoglobin in urea solution. 4. Inhibition by the reaction products was deduced from the fact that the digestion velocity of hemoglobin in urea solution varied with the asclepain concentration in agreement with the Schutz-Borissov rule. PMID- 19873156 TI - PHYSICOCHEMICAL PROPERTIES OF THE PROTEOLYTIC ENZYME FROM THE LATEX OF THE MILKWEED, ASCLEPIAS SPECIOSA TORR. SOME COMPARISONS WITH OTHER PROTEASES : III. KINETICS OF THE HEAT INACTIVATION OF PAPAIN, BROMELIN, AND ASCLEPAIN. AB - 1. The rates of heat inactivation of papain, bromelin, and asclepain were determined at several different temperatures. Papain was by far the most resistant to heat. 2. The destruction of papain at 75-83 degrees and bromelin at 55-70 degrees followed the course of a first order reaction, except that for longer times of heating, bromelin (at 60-70 degrees ) was inactivated more rapidly than the first order equation required. 3. The rate of inactivation of asclepain at 55-70 degrees followed the second order equation. 4. The critical thermal increments of inactivation of papain and bromelin, calculated with the van't Hoff-Arrhenius equation, were of the same high order that has been found for protein denaturation. The increment for asclepain was somewhat lower. PMID- 19873157 TI - ON THE RELATION BETWEEN BIRTH WEIGHT AND LITTER SIZE, IN MICE. AB - For mice, as for various other mammals, the relation between number N of young in a litter and the weight W of the litter can be expressed as W = aN(K). For adequately homogeneous data K has the nonspecific value 0.83. With data not homogeneous with respect to certain conditions the equation may still be descriptive, but with K higher than 0.83. Two kinds of mice obeying this formulation, with the same K, are an albino strain (AA) and a flex-tail foetal anemic (aa). Their ideal weights of a litter of 1 (W(1), free from effects of intrauterine competition) are quite different. Their F(1) offspring (from AA mothers) give W(1) precisely intermediate. To test the partition theory for the basis of the parabolic equation, backcross and F(2) litters were obtained in which for a span of litter sizes there occurred various proportions of anemic to non-anemic young. For equal numbers of each in the same litters the relation of weight of aa to weight of Aa young is again described by W(a) = aW(A) (K), and as before K = 0.83. Examination of the weights of anemic and of non-anemic young, for various proportions of the two in litters of different total numbers, shows that the partition theory can account for a number of the curious relations, including the fact that aa young and Aa young if in mixed litters increase in weight more for an increment of 1 in the litter than if in unmixed litters of the same N. This mechanical result of partitioning can be regarded as a kind of model for heterosis resulting from developmental disharmony. PMID- 19873158 TI - THE REACTIONS OF IODINE AND IODOACETAMIDE WITH NATIVE EGG ALBUMIN. AB - The following experimental results have been obtained. 1. Native egg albumin treated with iodine and then denatured no longer gives a nitroprusside test or reduces dilute ferricyanide in neutral Duponol PC solution. 2. More iodine is needed to abolish the ferricyanide reduction if the reaction between native egg albumin and iodine is carried out at pH 6.8 than if the reaction is carried out at pH 3.2. At pH 6.8 iodine reacts with tyrosine as well as with cysteine. 3. Cysteine and tryptophane are the only amino acids with reducing groups which are known to react with dilute iodine at pH 3.2 The reducing power of cysteine is abolished by the reaction with iodine, whereas the reducing power of tryptophane remains intact. Pepsin and chymotrypsinogen which contain tryptophane but not cysteine, do not react at all with dilute iodine at pH 3.2. 4. Native egg albumin treated with iodoacetamide at pH 9.0 and then denatured by Duponol PC reduces only 60 per cent as much dilute ferricyanide as egg albumin which has not been treated with iodoacetamide. 5. The SH group is the only protein reducing group which is known to react with iodoacetamide. The simplest explanation of the new observation that the SH groups of egg albumin can be modified by reactions with the native form of the protein is that the native egg albumin has free and accessible but relatively unreactive SH groups which can react with iodine and iodoacetamide despite the fact that they do not react with ferricyanide, porphyrindin, or nitroprusside. Preliminary experiments suggested by the results with egg albumin indicate that the tobacco mosaic virus is modified by iodine at pH 2.8 without being inactivated and that the tobacco mosaic and rabbit papilloma viruses are not inactivated by iodoacetamide at pH 8.0. PMID- 19873159 TI - A DIFFERENTIAL VOLUMETER FOR MICRO-RESPIRATION MEASUREMENTS. AB - A modified micro-respirometer employing the differential volumeter principle, and mechanical accessories for the same, are described. The apparatus enables addition of solutions to be made to the biological material during the experiment. It is of a high sensitivity, a drop movement of 1.0 mm. indicating a volume change of about 0.06 c.mm. It may be used with very small amounts of biological material, provides for convenience in manipulation) and allows readings to be made at 1 minute intervals. Typical results on plant tissue and protozoa are given. PMID- 19873160 TI - STABILIZATION OF SPIDER CRAB NERVE MEMBRANES BY ALKALINE EARTHS, AS MANIFESTED IN RESTING POTENTIAL MEASUREMENTS. AB - 1. The alkaline earths, Ba, Sr, Ca, and Mg, in isotonic solutions of their chlorides, have, in general, no effect upon the resting potential of non medullated spider crab nerve. 2. Ba, Sr, and Ca can, however, prevent the depressing action of K upon the resting potential. The order of effectiveness of these ions in this regard is the following: Ba > Sr > Ca. 3. Ba, Sr, Ca, and Mg oppose the depressing action of veratrine sulfate upon the resting potential. The order of effectiveness is Ba > Sr > Ca > Mg. The relation between drop in potential caused by veratrine sulfate and the logarithm of the veratrine sulfate concentration is a linear one. 4. The action of various other organic ions and molecules which depress the resting potential: saponin, amyl urethane, chloral hydrate, and Na salicylate is neutralized by Ba. 5. Hypertonic sea water solutions do not affect the resting potential. Also, preliminary experiments indicate that the nerves do not shrink in hypertonic solutions although they swell in hypotonic sea water. 6. The alkaline earths depress excitability reversibly. The various organic agents which depress the resting potential also depress excitability, in most cases, reversibly, but the concentrations necessary to depress excitability are much smaller than those necessary to depress the resting potential. 7. The relation of these findings to theories put forward as possible explanations of resting potential phenomena is considered. PMID- 19873161 TI - BEHAVIOR OF WATER IN CERTAIN HETEROGENEOUS SYSTEMS. AB - In various models designed to imitate living cells the surface of the protoplasm is represented by guaiacol which acts in some respects like certain protoplasmic surfaces. The behavior of water in these models presents interesting features and if these occur in vivo, as appears possible, they may help to explain some of the puzzling aspects of water relations in the living organism. When sufficient trichloroacetic acid is added to a two-phase system of water and guaiacol the two phases fuse into one. The effect of the acid is due to its attraction for water and for guaiacol. This is shown by the following facts. During the addition of the acid the mole fraction of water in the guaiacol phase increases but the activity of water in the guaiacol phase falls off. The activity coefficient of water may fall to less than one twelfth the value it had before acid was added. The behavior of guaiacol presents a similar picture. During the addition of acid the mole fraction of guaiacol in the aqueous phase increases but the activity of the guaiacol in the aqueous phase presumably decreases. Its activity coefficient calculated on this basis may fall to about one ninth of the value it had before the acid was added. Somewhat similar results are obtained when acetone is substituted for trichloroacetic acid or when ethanol is substituted for trichloroacetic acid and ethylene chloride for guaiacol. As trichloroacetic acid increases the mutual solubility of guaiacol and water we find that guaiacol saturated with water and having a high vapor pressure of water can take up water from an aqueous solution of trichloroacetic acid with a low vapor pressure of water: acid passes from the aqueous to the guaiacol phase, thus raising the vapor pressure of water in the aqueous phase and lowering it in the guaiacol phase. Diffusion experiments present some interesting features. When an aqueous solution, A, of trichloroacetic acid is separated by a layer of guaiacol, B, from distilled water, C, under certain conditions water moves from A to C. This depends on the fact that acid moves in the same direction and appears to carry water with it. Similar but less striking results were obtained with acetone diffusing through guaiacol and with ethanol diffusing through ethylene chloride. These phenomena differ from "anomalous osmosis" through solid membranes if it depends, as many suppose, on the diffusion of electrolytes through pores. We therefore suggest the term "anaphoresis" for the phenomena described here. Measurements of the mutual solubilities of water, guaiacol, and trichloroacetic acid and of water, guaiacol, and acetone are given and are discussed in relation to the diffusion experiments. To give a complete picture of the process of diffusion we need to know the activities and concentrations in all parts of the system. The difficulties of achieving this are obvious. The solubility relations are such that a concentration gradient of trichloroacetic acid in guaiacol produces a concentration gradient of water in the same direction, but the activity gradient of water is in the opposite direction. Since in certain respects guaiacol acts like some protoplasmic surfaces it seems possible that similar phenomena may occur in living cells. If so these results have an obvious bearing on the movement of water in the organism and on methods of studying permeability. It becomes necessary to know to what extent a substance entering or leaving the cell appears to carry water with it in the manner here indicated. In certain of the diffusion experiments the water takes a circular path, passing out of the dilute solution at one point and back into it (as vapor) at another. This circular path recalls the situation in the kidney where the water continually passes out of the blood into the glomerulus and tubule and then back into the blood from the tubule (where the solution is more concentrated). In both cases the circular path of the water is an essential feature. PMID- 19873162 TI - ELECTRON BOMBARDMENT OF BIOLOGICAL MATERIALS : II. THE RATE OF DEATH OF FUNGUS SPORES BOMBARDED IN VACUUM WITH CATHODE RAY BEAMS FROM 4 KV.-15 KV. AB - A study has been undertaken of the rate of inactivation of spores of the ascomycete fungus Aspergillus niger when bombarded in vacuum, with homogeneous beams of cathode rays of energies from 4 to 15 electron kv. and current densities of 1 x 10(-7) to 3 x 10(-6) amperes per square cm. These velocities and densities are in the range of those of showers of secondary electrons produced in biological materials irradiated with moderately soft x-rays, and so may be made to serve as quantitative indicators of the mechanics of x-ray action. Four qualitative effects are described. PMID- 19873163 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : III. OXYGEN CONSUMPTION AND CELL DIVISION OF FERTILIZED SEA URCHIN EGGS IN THE PRESENCE OF RESPIRATORY INHIBITORS. AB - 1. The effects of a number of respiratory inhibiting agents on the cell division of fertilized eggs of Arbacia punctulata have been determined. For eggs initially exposed to the reagents at 30 minutes after fertilization at 20 degrees C., the levels of oxygen consumption prevailing in the minimum concentrations of reagents which produced complete cleavage block were (as percentages of the control): In 0.4 per cent O(2)-99.6 per cent N(2), 32; in 0.7 per cent O(2)-99.3 per cent CO, 32; in 1.6 x 10(-4)M potassium cyanide, 34; in 1 x 10(-3)M phenylurethane, 70; in 4 x 10(-3)M 5-isoamyl-5-ethyl barbituric acid, 20; in 3 x 10(-4)M iodoacetic acid, 53. 2. The carbon monoxide inhibition of oxygen consumption and cell division was reversed by light. The percentage inhibition of oxygen consumption by carbon monoxide in the dark is described by the usual mass action equation with K, the inhibition constant, equal to approximately 60, as compared to values of 5 to 10 for yeast and muscle. In 20 per cent O(2)-80 per cent CO in the dark there was a slight stimulation of oxygen consumption, averaging 20 per cent. 3. Spectroscopic examination of fertilized and unfertilized Arbacia eggs reduced by hydrosulfite revealed no cytochrome bands. The thickness and density of the egg suspension was such as to indicate that, if cytochrome is present at all, the amount in Arbacia eggs is extremely small as compared to that in other tissues having a comparable rate of oxygen consumption. 4. Three reagents poisoning copper catalyses, potassium dithio-oxalate (10(-2)M), diphenylthiocarbazone (10( 4)M), and isonitrosoacetophenone (2 x 10(-3)M) produced no inhibition of division of fertilized Arbacia eggs. 5. These results indicate that the respiratory processes required to support division in the Arbacia egg may perhaps differ in certain essential steps from the principal respiratory processes in yeast and muscle. PMID- 19873164 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : IV. COMBINED ACTION OF SUBSTITUTED PHENOLS, CYANIDE, CARBON MONOXIDE, AND OTHER RESPIRATORY INHIBITORS ON RESPIRATION AND CELL DIVISION. AB - The effects of 4,6-dinitro-o-cresol and 2,4,5-trichlorophenol on the respiration and cell division of fertilized eggs of Arbacia punctulata have been determined in the presence of each of a number of respiratory inhibitors. The experimental results obtained appear to afford some understanding of the mechanism of action of the substituted phenols on respiration and on cell division. 1. From the fact that the stimulated respiration is completely cyanide and carbon monoxide sensitive, it may be concluded that all of the extra oxygen uptake induced in Arbacia eggs by 4,6-dinitro-o-cresol passes through the metal containing oxidase system. All of the extra oxygen uptake also passes through oxidative steps which can be poisoned by non-stimulating phenols like 2,4-dinitrothymol and 4 nitrocarvacrol, by phenylurethane, by 5-isoamyl-5-ethyl barbituric acid, by malonic acid, or by iodoacetic acid. To abolish all respiratory stimulation by suboptimum concentrations of 4,6-dinitro-o-cresol, each of these inhibitors must be present in a concentration which reduces the normal respiration in the absence of substituted phenols by at least 20-40 per cent. 2. The degree of reduction of the stimulated respiration by a given concentration of carbon monoxide or potassium cyanide depends on the concentration of 4,6-dinitro-o-cresol or 2,4,5 trichlorophenol, being most marked in suboptimum concentrations and least marked in greater than optimum concentrations of the substituted phenol. In contrast to this result, the reduction of the stimulated respiration by a given concentration of 5-isoamyl-5-ethyl barbituric acid or malonic acid is least marked in suboptimum concentrations and most marked in greater than optimum concentrations of the substituted phenol. 3. The present experiments appear to indicate that the inhibition of cell division by substituted phenols is not attributable to a direct action of these agents on mitotic processes nor to an overstimulation of any respiratory process. The inhibition of cell division appears to be associated with the inhibition, by the substituted phenols, of some component of the cyanide sensitive respiratory system. This inhibition is of such a type as to allow the overall respiration to proceed at a rate in excess of the control value, even when division is completely suppressed. The dependence of the division mechanism on a respiratory step which is relatively hypersensitive to poisoning by the substituted phenols is comparable to the dependence of the Pasteur reaction in certain normal and tumor tissues on an oxidative step which is specifically poisoned by the substituted phenols (16). The substituted phenols have no inhibiting effect in vitro on the principal metal containing respiratory catalysts or the principal dehydrogenases; they also do not inhibit the fermentative reactions involved in the anaerobic glycolysis of fertilized Arbacia eggs. It is therefore suggested that the respiratory inhibiting and division inhibiting effects of the substituted phenols may be attributable to the action of these substances on one or more of the oxidation-reduction or phosphorylating steps which are involved in the transfer of hydrogen from the dehydrogenase systems to the specifically cyanide sensitive oxidase mechanism of the eggs. The identification of the respiratory step poisoned by the substituted phenol would constitute an interesting contribution to the chemistry of cell division and experiments to this end are now in progress. PMID- 19873165 TI - SOME CHEMICAL ASPECTS OF THE POTASSIUM EFFECT. AB - The ability of Nitella to distinguish electrically between Na(+) and K(+) (potassium effect) appears to depend on several organic substances (or groups of substances). Of these R(MK) and R(SK) determine the mobility and partition coefficient (S) respectively of K(+) while R(MNa) and R(SNa) do the same for Na(+). These substances can vary independently and this variation is susceptible to experimental control. PMID- 19873166 TI - STUDIES ON PITUITARY LACTOGENIC HORMONE : I. ELECTROPHORETIC BEHAVIOR. AB - The Tiselius technique of electrophoresis has been used to study the homogeneity and mobility of pituitary lactogenic hormone. The lactogenic preparation employed by us shows only one sharp band in schlieren photographs, indicating a high degree of homogeneity. From the determination of the mobility of the hormone at different hydrogen ion concentrations in acetate and phosphate buffer of ionic strength 0.055, the isoelectric point was found to be 5.70 and the See PDF for Equation value 4.5 x 10(-5). The difference in the mobility reported for White's crystalline preparation and that found with our high potency lactogenic preparation is discussed. PMID- 19873167 TI - ELECTROPHORESIS OF PEPSIN. AB - 1. A number of pepsin solutions containing several protein components have been studied by the electrophoresis method. All samples show a homogeneous boundary moving to the anode at pH 4.4. 2. The activity of this material may be higher than that of the original solution on the basis of total nitrogen but is the same as that of the original solution on the basis of protein nitrogen. 3. There is no separation of the various protein components under these conditions. 4. The apparent isoelectric point at pH 2.7, previously obtained by the collodion particle method is due to the presence of decomposition products. Pure crystalline pepsin, free from decomposition products, is always negatively charged. PMID- 19873168 TI - TIME-TEMPERATURE RELATIONS IN THE INCUBATION OF THE WHITEFISH, COREGONUS CLUPEAFORMIS (MITCHILL). AB - 1. Whitefish eggs incubated in aerated lake water at controlled tempera tures of 0 degrees , 0.5 degrees , 2 degrees , 4 degrees , 6 degrees , 8 degrees , 10 degrees , and 12 degrees C., failed to hatch at either 0 degrees or 12 degrees C. 0.6 per cent hatched alive at 10 degrees C., 72.67 per cent hatched alive at 0.5 degrees C., and an intermediate proportion hatched at intermediate temperatures. 2. The percentage of abnormal embryos which developed to the hatching stage varied directly with temperature between 4 degrees and 12 degrees , all embryos being abnormal at 12 degrees C.; but none were abnormal at either 0.5 degrees , or 2 degrees C. Normal development predominated from 0.5 to 6 degrees C. The highest proportion of embryos to hatch alive was 72.67 per cent at 0.5 degrees C., which is, hence, the optimum temperature. 3. Total incubation time ranged from 29.6 days at 10 degrees C. to 141 days at 0.5 degrees C. 4. The time (T) required to attain any given stage of development is expressed in equations See PDF for Equation where temperature, t, is a negative exponent of the constant, A, whose value differs above or below 6 degrees C., a critical temperature. Values of A above 6 degrees fluctuate about 1.13; those of A below 6 degrees fluctuate about 1.19 as a mean. 5. Applying Arrhenius' equation micro values for the total incubation period are 27,500 below 6 degrees and 27,100 above it. 6. The relative magnitude of A values of the exponential equation and micro values of Arrhenius' equation show corresponding changes from one developmental period to another. 7. When plotted, thermal increments show cyclic variations, with maxima during periods of cleavage and of organogenesis. These may indicate the interaction of two separate sets of embryonic processes, which give a maximal response to temperature differences during these two separate periods. 8. Above 6 degrees , micro values during the hatching process are distinct from those of developmental stages and are regarded as being due to the action of hatching enzymes. PMID- 19873169 TI - THE PIGMENT-PROTEIN COMPOUND IN PHOTOSYNTHETIC BACTERIA : I. THE EXTRACTION AND PROPERTIES OF PHOTOSYNTHIN. AB - 1. Photosynthetic bacteria in water suspension break open when treated with supersonic vibration thus liberating the cell contents, including a water soluble protein to which is attached the otherwise water insoluble pigments, bacteriochlorophyll and carotinoids. Both types of pigments appear to be combined with the same protein. 2. The protein pigment compound is insoluble in the region of pH 3.0 to 4.5 and in neutral solution can be completely precipitated by 0.5 saturated (NH(4))(2)SO(4). It is soluble in distilled water and adsorbable on fullers' earth. 3. Supersonic extracts of photosynthetic bacteria do not have the ability to carry on photosynthesis, but will act as a photocatalyst for the oxidation of ascorbic acid with visible or infrared radiation. The rate of the photochemical oxidation is proportional to the light intensity. PMID- 19873170 TI - THE PIGMENT-PROTEIN COMPOUND IN PHOTOSYNTHETIC BACTERIA : II. THE ABSORPTION CURVES OF PHOTOSYNTHIN FROM SEVERAL SPECIES OF BACTERIA. AB - Absorption curves have been obtained in the spectral region of 450 to 900 mmicro for the water soluble cell juice of four species of photosynthetic bacteria, Spirillum rubrum (strain S1), Rhodovibrio sp. (strain Gaffron), Phaeomonas sp. (strain Delft), and Streptococcus varians (strains C11 and orig.). These curves all show maxima at 790 and 590 mmicro due to bacteriochlorophyll, whose highest band, however, occurs at 875, 855, or 840 mmicro depending on the species. The bacteria that appear red rather than brown have a band at 550 mmicro due to a carotinoid pigment. An absolute absorption curve of bacteriophaeophytin has maxima at 530 and 750 mmicro. The extraction of cell juice by supersonic vibration does not change the position of the absorption bands or of the light absorbing capacity of the pigment. PMID- 19873171 TI - BIOELECTRIC POTENTIALS IN HALICYSTIS : VIII. THE EFFECTS OF LIGHT. AB - The effects of light upon the potential difference across the protoplasm of impaled Halicystis cells are described. These effects are very slight upon the normal P.D., increasing it 3 or 4 per cent, or at most 10 per cent, with a characteristic cusped time course, and a corresponding decrease on darkening. Light effects become much greater when the P.D. has been decreased by low O(2) content of the sea water; light restores the P.D. in much the same time course as aeration, and doubtless acts by the photosynthetic production of O(2). There are in both cases anomalous cusps which decrease the P.D. before it rises. Short light exposures may give only this anomaly. Over part of the potential range the light effects are dependent upon intensity. Increased CO(2) content of the sea water likewise depresses the P.D. in the dark, and light overcomes this depression if it is not carried too far. Recovery is probably due to photosynthetic consumption of CO(2), unless there is too much present. Again there are anomalous cusps during the first moments of illumination, and these may be the only effect if the P.D. is too low. The presence of ammonium salts in the sea water markedly sensitizes the cells to light. Subthreshold NH(4) concentrations in the dark become effective in the light, and the P.D. reverses to a negative sign on illumination, recovering again in the dark. This is due to increase of pH outside the cell as CO(2) is photosynthetically reduced, with increase of undissociated NH(3) which penetrates the cell. Anomalous cusps which first carry the P.D. in the opposite direction to the later drift are very marked in the presence of ammonia, and may represent an increased acidity which precedes the alkaline drift of photosynthesis. This acid gush seems to be primarily within the protoplasm, persisting when the sea water is buffered. Glass electrode measurements also indicate anomalies in the pH drift. There are contrary cusps on darkening which suggest temporarily increased alkalinity. Even more complex time courses are given by combining low O(2) and NH(4) exposures with light; these may have three or more cusps, with reversal, recovery, and new reversal. The ultimate cause of the light effects is to be found in an alteration of the surface properties by the treatments, which is overcome (low O(2), high CO(2)), or aided (NH(4)) by light. This alteration causes the surface to lose much of its ionic discrimination, and increases its electrical resistance. Tests with various anion substitutions indicate this, with recovery of normal response in the light. A theory of the P.D. in Halicystis is proposed, based on low mobility of the organic anions of the protoplasm, with differences in the two surfaces with respect to these, and the more mobile Na and K. ions. PMID- 19873172 TI - THE THEORETICAL RESPONSE OF LIVING CELLS TO CONTACT WITH SOLID BODIES. PMID- 19873173 TI - TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT : VI. FLASH DURATION VARIED. AB - For the turtle Pseudemys scripta the temperature characteristics for excitability of the response to visual flicker are found to be independent of flash frequency F, flash intensity I, and proportion of light time in the flash cycle. The maximum F to which the flicker response contour (F vs. log I) rises, and the abscissa of its inflection, are rectilinear functions of the percentage light time in the flash cycle, but micro for 1/Iat any flash frequency is the same with different values of the percentage light-time (10 to 90 per cent). These facts, together with the properties of the variation of the critical intensity, objectively demonstrate the essentially simple or unitary character of the controlling events in the mechanism governing the excitability. They also provide a means of further illustrating a procedure whereby certain statistical factors in the performance of a population of units may be analytically separated from excitability properties common to all of the individual units. In particular, it is of general significance that it can be seen how it is possible for biologically exhibited frequencies or rates of performance to provide simple and physically significant relations to temperature, despite the fact that this performance may involve, almost inevitably does involve, the integrated actions of many individual units. PMID- 19873174 TI - THE CELL SAP OF HYDRODICTYON. AB - Analysis of the cell sap of Hydrodictyon patenaeforme Pocock, from California indicates the usual marked accumulation of potassium, which is 4000 times as concentrated as in the surrounding pond water. Small amounts of sodium and calcium were found. Chloride makes up about three-fourths of the anions, with a very high sulfate, and much lower bicarbonate concentration accounting for most of the remainder. Electrical conductivity and osmotic studies indicate that the analyzed elements are ionized, and account for most of the sap's osmotic pressure. pH is 5.5 to 6.0. The analytical procedure was designed to determine as many of the cations as possible on one small sample. Hydrodictyon is a large multinucleate cell belonging to an order (Chlorococcales) new to permeability and accumulation studies. PMID- 19873175 TI - EFFECTS OF HEXYLRESORCINOL ON NITELLA. AB - In some ways the effects of hexylresorcinol on Nitella resemble those of guaiacol but in others they differ. Both substances depress the P.D. reversibly and both decrease the potassium effect. Hexylresorcinol decreases the apparent mobility of Na(+) and of K(+). Guaiacol increases that of Na(+) but not of K(+). The action of hexylresorcinol is more striking than that of guaiacol since 0.0003 M of the former is as effective as 0.03 M of the latter in depressing the P.D. It is evident that organic substances can change the behavior of inorganic ions in a variety of ways. PMID- 19873177 TI - EXPERIMENTS ON THE ADAPTATION OF ESCHERICHIA COLI TO SODIUM CHLORIDE. AB - 1. It has been shown that a fairly constant fraction of the total number of bacteria in a fresh-water culture of E. coli can reproduce on direct transfer to a saline medium with a definite NaCl concentration, as judged from the viable count determinations in such a medium. 2. The absolute value of this fraction depends on a number of factors other than the salt content of the test medium, such as the hydrogen ion and yeast autolysate concentrations, aeration, and the physiological condition of the bacteria. 3. A method for testing the degree and rate of adaptation of the bacteria to saline environment, depending on the analysis of changes in the value of the salt-viable fraction, was developed. 4. Maximum adaptability to saline environments was found during the early stationary phase of NaCl-free cultures. Low adaptability accompanied the logarithmic phase and the senescence of the cultures. 5. The limits of variation could be extended by treatment of non-dividing cells with gradually increasing concentrations of salt or by subjecting them to a single intermediate NaCl concentration. This acclimatization was independent of reproduction. The number of bacteria becoming capable of reproducing in a hitherto unfavorable environment increased with the period of exposure to intermediate salt concentrations until a maximum value was reached. 6. This maximum value was shown to depend on the salinity of the test medium, the age of the bacterial culture, and the method of preliminary treatment. "Optimal acclimatization" could be effected by subjecting the organisms to a single fairly low intermediate NaCl concentration. 7. The rate of the individual acclimatization process was shown to be greater at higher than at lower temperatures. 8. Acclimatized bacteria rapidly lost their increased ability to reproduce in saline media upon return to a salt-free environment, although no reproduction of the cells could be detected. This was interpreted as an indication that the processes involved are readily reversible. 9. Studies on the reproduction of E. coli in strongly saline broth indicated that only those cells originally acclimatized to the salt concentration of the medium could divide. All cells produced in such a medium could continue to reproduce. The propagation in the altered medium was not accompanied by any further acclimatization throughout five subcultures. 10. Both the division rate and the maximum crop of cultures in saline broth were considerably lower than of those in a fresh-water medium. No change in either occurred throughout five successive subcultures. The morphology of the organisms was also altered by the presence of salt. 11. The division rate, maximum crop, morphology, and adaptive power returned immediately to normal on re transfer of bacteria grown in an NaCl-containing medium to "salt-free" broth. 12. The entire adaptive response of the bacteria to a considerable increase in the salinity of the environment could thus be separated into two components: an acclimatization, independent of reproduction, and a selection of those cells with the widest range of potentialities. PMID- 19873176 TI - THE COMPOSITION OF FLUIDS AND SERA OF SOME MARINE ANIMALS AND OF THE SEA WATER IN WHICH THEY LIVE. AB - 1. The electrolyte composition, the pH, and freezing points of the fluids of several invertebrates and one primitive chordate are reported. 2. Fluids of the worms, echinoderms, and the clam Venus were isotonic with sea water; fluids of the Arthropoda were hypertonic to sea water. 3. The pH of all fluids was below that of sea water. In the Arthropoda and Myxine less individual variation in pH appeared than in the echinoderms and worms. 4. Ratios of ionic concentrations in the fluid to those in the sea water indicated (1) uniform distribution of ions between the internal and external media for the echinoderms and Venus, (2) differential distribution of potassium and magnesium in the worms; (3) differential distribution of sulfate, magnesium, potassium, and calcium in the Arthropoda; and (4) differential distribution of calcium, magnesium, and sulfate in Myxine. 5. The unequal distribution of ions implies the expenditure of energy against a concentration gradient across the absorbing or excreting membranes, a capacity frequently overlooked in the invertebrates. 6. The sera of the Arthropoda from diluted sea water showed higher concentrations of sodium, potassium, calcium, and chloride ions relative to the respective concentrations in the external medium than in normal sea water, and also showed different orders for those ions. 7. The increase in osmotic pressure of the sera of the animals moving into brackish water is caused by unequal accumulation of sodium, potassium, calcium, and chloride ions. Sulfate and magnesium ionic ratios do not change. PMID- 19873178 TI - THE RELATION BETWEEN FOVEAL VISUAL ACUITY AND ILLUMINATION UNDER REDUCED OXYGEN TENSION. AB - 1. The foveal visual acuity of eleven subjects was studied in relation to illumination under normal atmospheric conditions and at simulated altitudes of 10,000 feet (14.3 per cent O(2)) and 18,000 feet (10.3 per cent O(2)). A mask was used to administer the desired mixtures of oxygen and nitrogen. At the end of each experiment, measurements were made while inhaling 100 per cent oxygen from a cylinder. A red filter (No. 70 Wratten) was used so as to study only the behavior of the cones of the retina. 2. The logarithm of illumination was plotted horizontally (abscissa) and the logarithm of visual acuity vertically (ordinate). The reduced oxygen tensions resulted in a shift of the curve to the right, along the intensity axis, the extent of the change being 0.24 of a log unit at 14.3 per cent O(2) and 0.47 of a log unit at 10.3 per cent O(2). These effects were completely counteracted within a few minutes by inhaling oxygen. 3. As a consequence of the shape of the curve, such a shift to the right resulted in a relatively large decrease of visual acuity at low illuminations. At increasing light intensities anoxia produced less and less change, until at very high illuminations the decrease was negligible. Thus with 10.34 per cent O(2) the visual acuity at 0.144 photons decreased an average of 0.344 of a log unit, to 45 per cent of its normal value. At 1320 photons, however, it decreased only 0.026 of a log unit, to 94 per cent of its normal value for that intensity. PMID- 19873179 TI - ADSORPTION OF BACTERIOPHAGE UNDER VARIOUS PHYSIOLOGICAL CONDITIONS OF THE HOST. AB - 1. The adsorption rate constant of phage to bacterium is found to change between wide limits, depending on the physiological state of the bacterium. 2. The experiments of Krueger and of Schlesinger on the residual free phage in contact with an excess of bacteria are discussed and the view of Schlesinger, that they represent phage particles with reduced affinity to the bacterial host is supported by experiments. 3. The theory of von Smoluchowski and Schlesinger is compared with the experiments. 4. The implications of these findings for the assay methods currently used are discussed. PMID- 19873180 TI - THE GROWTH OF BACTERIOPHAGE AND LYSIS OF THE HOST. AB - 1. A new strain of B. coli and of phage active against it is described, and the relation between phage growth and lysis has been studied. It has been found that the phage can lyse these bacteria in two distinct ways, which have been designated lysis from within and lysis from without. 2. Lysis from within is caused by infection of a bacterium by a single phage particle and multiplication of this particle up to a threshold value. The cell contents are then liberated into solution without deformation of the cell wall. 3. Lysis from without is caused by adsorption of phage above a threshold value. The cell contents are liberated by a distension and destruction of the cell wall. The adsorbed phage is not retrieved upon lysis. No new phage is formed. 4. The maximum yield of phage in a lysis from within is equal to the adsorption capacity. 5. Liberation of phage from a culture in which the bacteria have been singly infected proceeds at a constant rate, after the lapse of a minimum latent period, until all the infected bacteria are lysed. 6. If the bacteria are originally not highly in excess, this liberation is soon counterbalanced by multiple adsorption of the liberated phage to bacteria that are already infected. This leads to a reduction of the final yield. PMID- 19873181 TI - STUDIES ON THE CHLOROPHYLLS AND PHOTOSYNTHESIS OF THERMAL ALGAE FROM YELLOWSTONE NATIONAL PARK, CALIFORNIA, AND NEVADA. AB - 1. Myxophyceae normally growing at 65 degrees C. evolved oxygen upon irradiation and showed evidence of retaining the power to carry on the process of photosynthesis at 20 degrees C. This indicates that extra thermal energy is not essential for photosynthesis at least over a short period of time. 2. Chlorophyll a and b found in several species of Myxophyceae growing in waters ranging in temperature from 37-72 degrees C. are essentially the same as found in plants growing all over the world. Certain standard chemical tests and spectroscopic examination of the chlorophylls were used as the criteria for these comparisons. The ratio of chlorophyll a to b often varied considerably but in general chlorophyll a showed an increase over the percentage found in most plants. 3. Green algae (Chlorella sp.?) were the only forms found at The Geysers, California. The temperature of the waters from which collections were made varied from 49-66 degrees C. 4. Collections from Beowawe, Nevada were from waters ranging from 60-71 degrees C. The algae belonged to the Myxophyceae and the species were like some of those found in Yellowstone National Park. 5. In some of the calcareous regions of Yellowstone National Park spectroscopic study of the chlorophylls revealed an unidentified absorption band at 548 mmicro. PMID- 19873182 TI - REACTION TO VISUAL FLICKER IN THE NEWT TRITURUS. AB - The flicker response curve for the newt Triturus viridescens (water phase) has much the same quantitative structure as that found with various fresh-water teleosts at the same temperature (21.5 degrees ). The variability of critical intensity and of critical flash frequency likewise follows the same rules. The cone portion of the F - log I curve is much more widely spread, however. This, and the rather low maximum to which the rod curve rises, produce a considerable overlapping of the two parts additively fused. In addition, and to an extent which differs in various individuals, there is apparent a slight departure from the probability integral form of the cone curve. Reasons are given for considering that this is possibly connected with the role of an additional (small) number of (perhaps temporary, or developmental) retinal elements in addition to the typical rods and cones. PMID- 19873183 TI - THE FLICKER RESPONSE CURVE FOR FUNDULUS. AB - After Fundulus heteroclitus have been for some time in the laboratory, under conditions favorable for growth, and after habituation of the fishes to the simple routine manipulations of the observational procedure required, they are found to give reproducible values of the mean critical flash illumination (I(m)) resulting in response to visual flicker. The measurements were made with equality of light time and dark time in the flash cycle, at 21.5 degrees C. Log I(m) as a function of flash frequency F has the same general form as that obtained with other fishes tested, and for vertebrates typically: the curve is a drawn-out S, with a second inflection at the low I end. In details, however, the curve is somewhat extreme. Its composite form is readily resolved into the two usual parts. Each of these expresses a contribution in which log I, as a function of F, is accurately expressed by taking F as the summation (integral) of a probability distribution of d log I, as for the flicker response contour of other animals. As critical intensity I increases, the contribution of rod elements gradually fades out; this decay also adheres to a probability integral. The rod contribution seen in the curve for Fundulus is larger, absolutely and relatively to that from the cones, than that found with a number of other vertebrates. The additive overlapping of the rod and cone effects therefore produces a comparatively extreme distortion of the resulting F-log I curve. The F-log I(m) curve is shifted to lower intensities as result of previous exposure to supranormal temperatures. This effect is only very slowly reversible. The value of F(max.) for each of the components of the duplex curve remains unaffected. The rod and cone segments are shifted to the same extent. The persisting increase of excitability thus fails to reveal any chemical or other differentiation of the excitability mechanism in the two groups of elements. Certain bearings of the data upon the theory of the flicker response contour are discussed, with reference to the measurements of variation of critical intensity and to the form of the F-log I curve. The quantitative properties of the data accord with the theory derived from earlier observations on other forms. PMID- 19873184 TI - THE PURIFICATION OF CATHEPSIN. AB - 1. One mg. of the purified cathepsin whose preparation is described is as active as the extract of 1.3 gm. of spleen. An eightfold further purification is possible by procedures which are still being modified and so are not described in the present paper. 2. The first step of the purification consists in suspending frozen and thawed spleen in water and letting it autolyze. 3. In the second step, ammonium sulfate is added and the suspension is acidified and warmed. Much additional autolysis takes place. The cathepsin is protected from destruction by being adsorbed to the insoluble spleen material. When this insoluble material is filtered off most of the products of autolysis remain in the filtrate. 4. The cathepsin is then released from the insoluble spleen material by making the suspension slightly alkaline. Some inert protein still remains adsorbed to the insoluble spleen material. 5. More inert protein is removed by adsorption with aluminum hydroxide formed in the cathepsin solution by the addition first of aluminum chloride and then of sodium hydroxide. Preformed aluminum hydroxide is a much less effective adsorbent. 6. The purified cathepsin is precipitated from very dilute solution with tungstic acid. Tungstic acid precipitates most proteins in the native form provided the solution is not too acid. 7. Further evidence is given that cathepsin is not a proteinase of the papain type. PMID- 19873185 TI - THE PHOTODYNAMIC INACTIVATION OF PHAGE PRECURSOR BY METHYLENE BLUE. AB - Methylene blue added to suspensions of activated staphylococci in amounts sufficient to furnish 1 x 10(5) molecules of dye/bacterium inactivates the phage precursor content of the cells without causing cell death when the mixtures are exposed to strong light of 4000-8000 A. There is a lag phase of approximately 15 minutes in the photodynamic inactivation of phage precursor by methylene blue. This delay seems to be due to a primary reaction between the cell and methylene blue after the completion of which exposure to light brings about the inactivation of precursor quite promptly. PMID- 19873186 TI - THE SENSIBILITY OF THE NOCTURNAL LONG-EARED OWL IN THE SPECTRUM. AB - Infrared radiation (750-1500 mmicro) produces no iris contraction in the typically nocturnal long-eared owl even when the energy content is millions of times greater than that of green light which easily elicits a pupil change. The energies in different parts of the visible spectrum required for a minimal iris response yield a spectral visibility curve for the owl which is the same as the human visibility curve at low light intensities. Functionally, the owl's vision thus corresponds to the predominantly rod structure of its retina, and the idea that nocturnal owls have a special type of vision sensitive to infrared radiation for seeing in the woods at night is erroneous. PMID- 19873187 TI - SOLUBILITY STUDIES ON PURIFIED TOBACCO MOSAIC VIRUS. AB - Different samples of purified tobacco mosaic virus show a relatively wide variation in solubility in ammonium sulfate solution. This variation and the type of solubility curve obtained in the presence of varying amounts of solid phase show that the purified virus whether isolated by mild treatment with ammonium sulfate or by ultracentrifugation is not a homogeneous chemical substance but contains more soluble and less soluble virus fractions of comparable specific activities. Long contact with strong ammonium sulfate solutions or 0.1 M phosphate buffer results in a decrease in solubility. The variation in the solubility of samples isolated from different plants by the same method seems to depend in part on the length of time the plants are inoculated before they are cut, and probably also on the conditions under which they are grown. Virus preparations isolated from plants of different genera grown under the same conditions and inoculated at the same time, however, behaved like identical substances in solubility experiments. PMID- 19873188 TI - SUMMATION OF ELECTRICAL POTENTIAL OF LIVING MEMBRANES (FROG SKIN): A MODEL OF THE ELECTRICAL ORGAN OF FISHES. AB - Frog skins arranged "in series" in tubes of Ringer's solution exhibit summation of electrical potential which helps to explain the nature of electrical fields in the organism as a whole and in the electrical organ of fishes. See PDF for Structure. PMID- 19873189 TI - ELECTROPHORETIC HOMOGENEITY OF PREGNANT MARE SERUM GONADOTROPHIN. AB - A highly purified and potent gonadotrophin in pregnant mare serum has been prepared. The preparation has been shown to be electrophoretically homogeneous in the Tiselius apparatus. The mobilities of the substance have been determined over a wide range of hydrogen ion concentrations. The isoelectric point lies at pH 2.60-2.65 and the value of See PDF for Equation is 4.0 x 10(-5). Some chemical constituents have been studied. From the tryptophane and tyrosine content the molecular weight of the hormone is estimated to be 30,000. The hormone has been subjected to acetylation by ketene in aqueous solution at room temperature and the result suggests again the essentiality of free amino groups for the biological activity of the hormone. In this respect it is to be contrasted with human chorionic gonadotrophin. PMID- 19873190 TI - SEPARATION OF POTASSIUM ISOTOPES IN VALONIA AND NITELLA. AB - The ratio of K(39) / K(41) appears to be lower in the sap of Valonia and Nitella than in the environment, indicating that the living cell can separate these isotopes to some extent. Experiments with a mixture of guaiacol and p-cresol suggest that a similar separation may occur here but further experiments are needed. PMID- 19873191 TI - ACTION CURVES WITH SINGLE PEAKS IN NITELLA IN RELATION TO THE MOVEMENT OF POTASSIUM. AB - In Nitella the action curve has two peaks, apparently because both protoplasmic surfaces (inner and outer) are sensitive to K(+). Leaching in distilled water makes the outer surface insensitive to K(+). We may therefore expect the action curve to have only one peak. This expectation is realized. The action curve thus obtained resembles that of Chara which has an outer protoplasmic surface that is normally insensitive to K(+). The facts indicate that the movement of K(+) plays an important part in determining the shape of the action curve. PMID- 19873192 TI - EFFECTS OF GUAIACOL AND HEXYLRESORCINOL IN THE PRESENCE OF BARIUM AND CALCIUM. AB - Guaiacol was applied at two spots on the same cell of Nitella. At one spot it was dissolved in 0.01 M NaCl, at the other in 0.01 M CaCl(2) or BaCl(2). The effect was practically the same in all cases, i.e. a similar change of P.D. in a negative direction, involving a more or less complete loss of P.D. (depolarization). When hexylresorcinol was used in place of guaiacol the result was similar. That Ca(++) and Ba(++) do not inhibit the effect of these organic depolarizing substances may be due to a lack of penetration of Ca(++) and Ba(++). The organic substances penetrate more rapidly and their effect is chiefly on the inner protoplasmic surface which is the principal seat of the P.D. PMID- 19873193 TI - THE ELECTRICAL CONDUCTANCE OF SUSPENSIONS OF ELLIPSOIDS AND ITS RELATION TO THE STUDY OF AVIAN ERYTHROCYTES. AB - 1. The theory of electrical conductance of colloidal suspensions has been extended to cover the case of ellipsoids with three axes different. 2. The results have been applied to suspensions of ellipsoidal erythrocytes of birds. 3. It has been shown that fluctuations in electrical resistance of suspensions of erythrocytes after stirring are due to streaming orientation of the cells. 4. The theory has been extended to cover four cases of orientation and tested experimentally in specially designed flow cells by electrical and optical methods. 5. Application of the flow method to the study of the shape of colloidal particles is discussed. PMID- 19873194 TI - THE INFLUENCE OF SODIUM CHLORIDE AND TEMPERATURE ON THE ENDOGENOUS RESPIRATION OF B. CEREUS. AB - Measurements were made of the rate of consumption of oxygen by suspensions of B. cereus, in sodium chloride solutions of concentration up to 1.8 M and over a range of pH from 6.0 to 7.5. It was found: 1. That the temperature coefficient was independent of the presence of sodium chloride in concentrations between 0.2 and 1.8 M, although the rate of respiration was lowered considerably under these conditions. 2. That in the presence of concentrations of sodium chloride less than 0.2 M, the rate of respiration was increased, and so was the temperature coefficient. 3. That small changes in the temperature coefficient occurred when the pH was changed. The temperature coefficient was higher the higher the rate of respiration. These data may be more readily interpreted by the hypothesis that the temperature coefficient is controlled by some master reaction, than by that which supposes that the temperature coefficient is determined by protoplasmic viscosity. PMID- 19873195 TI - NEW EXPERIMENTS ON ANOMALOUS OSMOSIS. AB - 1. It is impossible to reproduce Loeb's observations on anomalous osmosis with membranes prepared from relatively pure brands of collodion, whereas positive effects can be obtained using collodion containing acidic impurities. 2. The inactive (purer) collodion membranes may be activated by oxidation with NaOBr solution. 3. Properly oxidized membranes give much greater anomalous osmotic effects than those described by Loeb. PMID- 19873196 TI - THE EFFECT OF STIMULATION OF THE SENSES OF VISION, HEARING, TASTE, AND SMELL UPON THE SENSIBILITY OF THE ORGANS OF VISION. PMID- 19873197 TI - CRYSTALLINE RIBONUCLEASE. AB - 1. A crystalline enzyme capable of digesting yeast nucleic acid has been isolated from fresh beef pancreas. 2. The enzyme called "ribonuclease" is a soluble protein of albumin type. Its molecular weight is about 15,000. Its isoelectric point is in the region of pH 8.0. 3. Ribonuclease splits yeast nucleic acid into fragments small enough to diffuse readily through collodion or cellophane membranes. 4. The split products of digestion, unlike the undigested yeast nucleic acid, are not precipitable with glacial acetic acid or dilute hydrochloric acid. 5. The digestion of yeast nucleic acid is accompanied by a gradual formation of free acid groups without any significant liberation of free phosphoric acid. 6. Ribonuclease is stable over a wide range of pH even when heated for a short time at 100 degrees C. Its maximum stability is in the range of pH 2.0 to 4.5. 7. Denaturation of the protein of ribonuclease by heat or alkali, or digestion of the protein by pepsin, causes a corresponding percentage loss in the enzymatic activity of the material. PMID- 19873198 TI - THE EFFECT OF OXIDANTS AND REDUCTANTS UPON THE BIOELECTRIC POTENTIAL OF NITELLA. AB - Nitella cells were exposed to various oxidants and reductants, to determine their effect upon the bioelectric potential. These included five systems, with an E(h) range from +0.454 v. to -0.288 v., a total range of 0.742 v. When proper regard was given to buffering against acidity changes, and concentration changes of Na or K ions in the oxidized and reduced forms, no significant effect upon the bioelectric potential was found: 1. When an oxidant or reductant (K ferri- or ferrocyanide) was applied instead of an equivalent normality of an "indifferent" salt (KCl). 2. In changing from a given oxidant to its corresponding reductant (ferri- to ferrocyanide; oxidized to leuco-dye, etc.). 3. When a mixture of 2 dyes, (indophenol with positive E'(0), and safranin with negative E'(0)) was oxidized and reduced, to give better poising at the extremes. It is conduded that the outer surface of this cell is not influenced by the state of oxidation or reduction of the systems employed; at least it does not respond with a manifest change of bioelectric potential to changes in oxidation-reduction intensity of the medium. The cells continued to show, however, at all times their usual response to concentration changes of KCl, NaCl, etc., and to electrical stimulation. PMID- 19873199 TI - STUDIES ON PHOTOSYNTHESIS : SOME EFFECTS OF LIGHT OF HIGH INTENSITY ON CHLORELLA. AB - 1. The effect on oxygen evolution of Chlorella vulgaris produced by light intensities up to about 40,000 f.-c. has been studied by the use of the Warburg technique. 2. Above a certain critical intensity, which is determined by the previous history of the cells, the rate of oxygen evolution decreases from the maximum to another constant rate. This depression is at first a completely reversible effect. 3. With a sufficiently high intensity this constant rate represents an oxygen uptake greater than the rate of dark respiration. During such a constant rate of oxygen uptake a progressive injury to the photosynthetic mechanism takes place. After a given oxygen consumption the rate falls off, approaching zero, and the cells are irreversibly injured. 4. The constant rate of oxygen evolution (2 and 3) decreases in a continuous manner with increasing light intensities, approaching a value which is approximately constant for all lots of cells regardless of previous history. 5. Two alternative hypotheses have been presented to explain the observed phenomena. The more acceptable of these proposes quick inactivation of the photosynthetic mechanism, the extent of inhibition depending on the light intensity. 6. In Chlorella vulgaris solarization is influenced by the previous history of the cells. PMID- 19873200 TI - THE EFFECTS OF VARIATIONS IN THE CONCENTRATION OF OXYGEN AND OF GLUCOSE ON DARK ADAPTATION. AB - In this study we have analyzed the effects of variations in the concentrations of oxygen and of blood sugar on light sensitivity; i.e. dark adaptation. The experiments were carried out in an air-conditioned light-proof chamber where the concentrations of oxygen could be changed by dilution with nitrogen or by inhaling oxygen from a cylinder. The blood sugar was lowered by the injection of insulin and raised by the ingestion of glucose. The dark adaptation curves were plotted from data secured with an apparatus built according to specifications outlined by Hecht and Shlaer. During each experiment, observations were first made in normal air with the subject under basal conditions followed by one, and in most instances two, periods under the desired experimental conditions involving either anoxia or hyper- or hypoglycemia or variations in both the oxygen tension and blood sugar at the same time. 1. Dark adaptation curves were plotted (threshold against time) in normal air and compared with those obtained while inhaling lowered concentrations of oxygen. A decrease in sensitivity was observed with lowered oxygen tensions. Both the rod and cone portions of the curves were influenced in a similar way. These effects were counteracted by inhaling oxygen, the final rod thresholds returning to about the level of the normal base line in air or even below it within 2 to 3 minutes. The impairment was greatest for those with a poorer tolerance for low O(2). Both the inter- and intra-individual variability in thresholds increased significantly at the highest altitude. 2. In a second series of tests control curves were obtained in normal air. Then while each subject remained dark adapted, the concentrations of oxygen were gradually decreased. The regeneration of visual purple was apparently complete during the 40 minutes of dark adaptation, yet in each case the thresholds continued to rise in direct proportion to the degree of anoxia. The inhalation of oxygen from a cylinder quickly counteracted the effects for the thresholds returned to the original control level within 2 to 3 minutes. 3. In experiments where the blood sugar was raised by the ingestion of glucose in normal air, no significant changes in the thresholds were observed except when the blood sugar was rapidly falling toward the end of the glucose tolerance tests. However, when glucose was ingested at the end of an experiment in low oxygen, while the subject remained dark adapted, the effects of the anoxia were largely counteracted within 6 to 8 minutes. 4. The influence of low blood sugar on light sensitivity was then studied by injecting insulin. The thresholds were raised as soon as the effects of the insulin produced a fall in the blood sugar. When the subjects inhaled oxygen the thresholds were lowered. Then when the oxygen was withdrawn so that the subject was breathing normal air, the thresholds rose again within 1 to 2 minutes. Finally, if the blood sugar was raised by ingesting glucose, the average threshold fell to the original control level or even below it. 5. The combined effects of low oxygen and low blood sugar on light sensitivity were studied in one subject (W. F.). These effects appeared to be greater than when a similar degree of anoxia or hypoglycemia was brought about separately. 6. In a series of experiments on ten subjects the dark adaptation curves were obtained both in the basal state and after a normal breakfast. In nine of the ten subjects, the food increased the sensitivity of the subjects to light. 7. The experiments reported above lend support to the hypothesis that both anoxia and hypoglycemia produce their effects on light sensitivity in essentially the same way; namely, by slowing the oxidative processes. Consequently the effects of anoxia may be ameliorated by giving glucose and the effects of hypoglycemia by inhaling oxygen. In our opinion, the changes may be attributed directly to the effects on the nervous tissue of the visual mechanism and the brain rather than on the photochemical processes of the retina. PMID- 19873201 TI - CHEMICAL RESTORATION IN NITELLA : IV. EFFECTS OF GUANIDINE. AB - Leaching in distilled water may remove irritability and the potassium effect in Nitella but both of these may be restored by appropriate treatment with guanidine. PMID- 19873202 TI - THE EXPERIMENTAL PRODUCTION OF DOUBLE PEAKS IN CHARA ACTION CURVES AND THEIR RELATION TO THE MOVEMENT OF POTASSIUM. AB - The action curve in Chara seems to depend (as in Nitella) on the outward movement of K(+) from the sap. Presumably the increase in permeability in the inner protoplasmic surface and the outward movement of K(+) destroy the concentration gradient of K(+) across the inner protoplasmic surface. Hence the outwardly directed P.D. disappears, causing the rise (spike) of the action curve. The outer protoplasmic surface is normally insensitive to K(+). But when it is made sensitive to K(+) by treatment with guanidine the outwardly moving K(+) sets up a positive P.D. on reaching the outer surface and this causes the action curve to fall, producing a peak. Then the curve has 2 peaks, the second being due to the process of recovery. The action curve thus comes to resemble that of Nitella in which the outer protoplasmic surface is normally sensitive to K(+). PMID- 19873203 TI - ENZYMES IN ONTOGENESIS (ORTHOPTERA) : XIII. ACTIVATION OF PROTYROSINASE AND THE OXIDATION OF ASCORBIC ACID. AB - 1. Protyrosinase from the egg of the grasshopper, Melanoplus differentialis, can be activated by excess sodium oleate or Aerosol. 2. The 3:4 quinone products of the reaction of activated protyrosinase with tyramine or tyrosine will oxidize ascorbic acid to dehydroascorbic acid. 3. The velocity of this latter oxidation of ascorbic acid increases with the amount of tyramine or tyrosine. 4. The oxidation of ascorbic acid by the tyramine-tyrosinase reaction delays the time of appearance of a red color associated with an indole quinone intermediary product in the formation of melanin. 5. Protyrosinase, in itself, and in the presence of tyrosinase substrates does not bring about the oxidation of ascorbic acid. 6. A naturally occurring substrate in a preparation of protyrosinase, sufficient to cause the oxidation of ascorbic acid, can be removed by dialysis against a 0.9 per cent sodium chloride solution. 7. Dialysis against such a solution does not change the properties of protyrosinase; the inactive enzyme must still be activated before it will catalyze the oxidation of tyramine or tyrosine. 8. When the natural substrate, tyrosine, or tyramine is absent, activation of protyrosinase does not result in the oxidation of ascorbic acid. PMID- 19873204 TI - THE ROLE OF ORGANIC SUBSTRATES IN PHOTOSYNTHESIS OF PURPLE BACTERIA. AB - A representative of the photosynthetic non-sulfur purple bacteria (Athiorhodaceae) capable of using simple alcohols has been isolated in pure culture. By means of quantitative analysis of cultures at different stages of development it has been shown that this organism converts isopropanol quantitatively into acetone, simultaneously reducing CO(2) in the light. The data can be represented by the equation 2 CH(3)CHOHCH(3) + CO(2) --> 2 CH(3)COCH(3) + (CH(2)O) + H(2)O. Manometric experiments with suspensions of resting cells have fully corroborated the results obtained with growing cultures. The experiments have conclusively proved that an organic substrate may fulfill exclusively the function of hydrogen donor for the photochemical CO(2)-reduction in purple bacteria photosynthesis. PMID- 19873205 TI - A NEW FORM OF DIFFERENTIAL MICRORESPIROMETER. AB - 1. A microrespirometer suitable for measuring oxygen uptakes from 0.1 to 10lambda per hour is described. 2. The sensitivity of the instrument may be readily altered by substituting different sizes of capillary tubing. 3. By means of replaceable brass plugs the chamber volume of this instrument may be varied from 700 to less than 40lambda. 4. No thermostat is required for the operation of the instrument at room temperature. 5. It may be charged at one temperature and used at a widely different one. 6. The chambers may be filled with any desired gas mixture. 7. Two solutions may be mixed during the course of an experiment. 8. The entire apparatus may be sterilized. PMID- 19873206 TI - THE UPTAKE OF INORGANIC ELECTROLYTES BY THE CRAYFISH. AB - 1. Reasons are given for believing that the uptake of Na(+), Cl(-), and NaCl by the crayfish occurs through the gills. 2. A crayfish in fresh water, with a Cl concentration of about 0.2 mEq./l., can) by active Cl absorption, compensate entirely for Cl lost in the urine. 3. The carbonic anhydrase activity of the gills is markedly higher than that of other tissues of the crayfish, but the equivalent CO(2) output of the crayfish is far in excess of the equivalent Cl absorption per unit time and weight and thus fails to warrant the supposition that Cl absorption is of respiratory importance. 4. The carbonic anhydrase activity of the soft integument of the lobster, before and after molting, and of the hypodermis of the hard-cuticled animal is almost identical and of the same order as that of other tissues of the lobster. 5. The concentration of the electrolytes was about 7.5 mEq./l.; i.e., considerably lower than in the blood of the crayfish. Cl(-) can be taken up independently of the complementary cation. Na(+) can be taken up independently of the complementary anion. K(+) and SO(4) (=) are not taken up at all. In pure NaCl, the Na(+) and Cl(-) are absorbed evidently largely together. Ca(++) is absorbed only in newly molted animals and in animals preparing to molt but is not absorbed by hard-cuticled animals not preparing to molt. Ca(++) is taken up independently of Cl(-) in pure CaCl(2). 6. Newly molted animals absorb Ca(++) at a rate exceeding that of the absorption of other absorbable ions (Na(+) and Cl(-)) in the same equivalent concentration. 7. A crayfish utilizes the Ca(++) in fresh water in the calcification of its cuticle. Since the animal does not swallow water, the Ca(++) must enter through the exterior. Reasons are given for believing that, unlike Na(+) and Cl(-), Ca(++) is absorbed directly from the exterior by the integument and does not enter the body through the gills. 8. During molting, only about 4 per cent of the raw ash and 2.3 per cent of the organic material of the old cuticle is resorbed. PMID- 19873207 TI - KINETICS OF THROMBIN INACTIVATION AS INFLUENCED BY PHYSICAL CONDITIONS, TRYPSIN, AND SERUM. AB - 1. A new technique for studying the progressive inactivation of thrombin is described. 2. Thrombin inactivation follows the kinetics of a first order reaction. 3. The rate constant of the inactivation reaction increases with temperature and pH (5.0 --> 10.0), and also with the presence of crystalline trypsin, or serum. The rate varies for different thrombin preparations, even under the same experimental conditions. 4. The temperature characteristics of the reaction indicate that thrombin is associated with protein. 5. Thrombin preparations are most stable at pH 4 to 5, even when trypsin or serum is added. 6. The progressive inactivation is believed to be due to two mechanisms: (1) a major effect, thought to be the action of a "serum-tryptase," which is usually present in the thrombin preparations, and (2) a minor effect, probably attributable to denaturation of thrombin-protein. 7. Sources of the thrombinolytic factor (serum-tryptase) and its implications in the general theory and practical problems of blood coagulation and antithrombic action are briefly discussed. PMID- 19873208 TI - THE USE OF SOLUBILITY AS A CRITERION OF PURITY OF PROTEINS : I. APPLICATION OF THE PHASE RULE TO THE SOLUBILITY OF PROTEINS. II. THE SOLUBILITY CURVES AND PURITY OF CHYMOTRYPSINOGEN. AB - 1. The conditions under which the phase rule may be applied to systems containing proteins are formulated. 2. An attempt was made to fractionate chymotrypsinogen, by crystallization in stages with increasing concentration of magnesium sulfate. No significant fractionation of the protein was achieved, but a small amount of impurity which affects the solubility, while having little influence on other properties of the material, was concentrated in the fractions first precipitated. 3. The solubility of the final fraction was independent of the amount of the saturating solid, from the first appearance of a solid phase, in solvents of three different pH's. The solubility was independent of the environment in which the crystals were formed (within the limits in which crystallization can be carried out) and the same value was reached from the supersaturated as from the undersaturated side. This material, therefore, conforms closely with the phase rule criteria of a pure protein. PMID- 19873209 TI - MOLECULAR WEIGHT AND ELECTROPHORESIS OF CRYSTALLINE RIBONUCLEASE. AB - Electrophoretic studies on purified crystalline ribonuclease showed the absence of any impurities differing in mobility from the bulk of material. The isoelectric point of ribonuclease was found by electrophoresis to be at about pH 7.8. Ultracentrifuge studies indicated fair homogeneity of ribonuclease in solution. Only one moving component has been observed. The molecular weight of ribonuclease was found to be 12,700 from rate of sedimentation (S(25) = 1.85 x 10(-13) in 0.5 M (NH(4))(2)SO(4)) and diffusion measurement (D = 1.36 x 10(-6) in 0.5 M (NH(4))(2)SO(4)), in good agreement with the average value of 13,000 found from equilibrium measurements. This low value for the molecular weight of a protein would seem to discredit the value 17,600 as representing a universal unit weight for proteins in general. PMID- 19873210 TI - FRACTIONATION OF PEPSIN : I. ISOLATION OF CRYSTALLINE PEPSIN OF CONSTANT ACTIVITY AND SOLUBILITY FROM PEPSINOGEN OR COMMERCIAL PEPSIN PREPARATIONS. II. PREPARATION OF A LESS SOLUBLE FRACTION. III. SOLUBILITY CURVES OF MIXTURES OF THE SOLUBLE AND INSOLUBLE FRACTIONS. IV. PREPARATION OF HIGHLY ACTIVE PEPSIN FROM PEPSINOGEN. AB - 1. Solubility curves of crude pepsin preparations indicate the presence of more than one protein. 2. One of these proteins has been isolated and crystallized and found to have constant activity and constant solubility in several solvents. 3. The solubility measurements are complicated by the unstable nature of the protein and the fact that in certain solvents the solubility of the protein is markedly affected by the presence of non-protein nitrogen decomposition products while in others this is not the case. 4. A more insoluble protein has been prepared of lower solubility and lower activity, as measured by hemoglobin digestion. The activity, as measured by the digestion of other proteins, is about the same as the more soluble fraction. This insoluble fraction does not have constant solubility. 5. Mixtures of the insoluble and the soluble fractions give preparations having rounded solubility curves typical of solid solutions and resembling very closely those of the original preparation. 6. A small amount of pepsinogen and pepsin from pepsinogen has been separated which has nearly twice the enzymatic activity on hemoglobin as does the most active pepsin previously isolated. PMID- 19873211 TI - THE ELECTRICAL CAPACITY OF VALONIA : DIRECT CURRENT MEASUREMENTS. AB - Impaled cells of Valonia were balanced in a Wheatstone bridge against a simple series-parallel circuit of two resistances and a capacity, the transient charge and discharge curves at make and break of direct current being recorded with a string galvanometer. With the resistances properly balanced, a series of characteristic deflections resulted when the balancing capacity was varied. With many cells, no complete capacity balance was ever attained over the entire transient time course; but instead either a monophasic or diphasic residual deflection always remained. This behavior is comparable to that of a polarizing electrode in D.C., although not so clearly marked; and it is concluded that Valonia usually has an appreciable polarization component, probably in parallel with a static capacity. However, some cells can be balanced almost completely against a mica condenser of proper value, which indicates that they display a nearly pure static capacity under some conditions. This static state could be produced experimentally by exposure to weak acids (acetic, carbonic, etc.) and by metabolic agents probably inducing internal acidity (low oxygen tension, long exposure to cold, narcotics, etc.). Conversely, penetrating weak bases, such as ammonia, abolished the static capacity, or even any regular polarization. Light acts something like ammonia, after an initial "acid gush" anomaly. Most of these agents likewise affect the P.D. and its response to external ionic alterations, and it seems likely that the change in capacity type reflects altered ionic permeabilities and relative mobilities. PMID- 19873212 TI - THE EFFECT OF UNILATERAL ULTRAVIOLET LIGHT ON THE DEVELOPMENT OF THE FUCUS EGG. AB - 1. When Fucus eggs which have been fertilized for a sufficient length of time are irradiated unilaterally with monochromatic ultraviolet light (lambda2804 A) of adequate dosage, 97-100 per cent form rhizoids on the halves of the eggs away from the source of radiation (see Figs. 1 and 2). 2. The responsiveness of the eggs increases gradually after fertilization and does not reach a maximum until about 7 hours at 15 degrees C. (see Fig. 3). The first rhizoids begin to form in a population at about 12 hours after fertilization. The responsiveness remains maximal until at least 11 hours after fertilization. 3. It is suggested that the low responsiveness of a population of eggs at an earlier period is due to recovery from the effects of irradiation before the rhizoids begin to form. 4. The response of eggs to lambda2804 A is proportional, over a wide range, to the logarithm of the dosage (see Fig. 1). Dosage was regulated by the duration of exposure during the period of maximum response. 5. High dosages of lambda2804 A, of the order of 10,000 ergs per mm.(2), cause the rhizoids to form fairly precisely away from the source of radiation (see Fig. 2). Twice this dosage inhibits rhizoid formation altogether without causing cytolysis. 6. Other wave lengths which have also been shown to be effective are: 3660, 3130, 2654, 2537, 2482, and 2345 A. Only exploratory measurements have been made to test the effectiveness of these wave-lengths, but they show that much greater energy is necessary to obtain a strong response with lambda3130 and 3660 A, especially the latter. The wave-lengths shorter than 2804 A, on the other hand, show the same order of effectiveness as lambda2804 A. Some may be more effective. 7. A beam of lambda2804 A which is incident on a single layer of Fucus eggs is completely extinguished at 2, 3, 6, or 6(1/2) hours after fertilization. About 85 per cent of a beam of lambda3660 A is extinguished. The wave-length 3660 A is thus not so completely absorbed as lambda2804 A, but the difference in proportion absorbed by the egg is not nearly so great as the difference in effectiveness. PMID- 19873213 TI - ON THE RELATION BETWEEN GROWTH AND RESPIRATION IN THE AVENA COLEOPTILE. AB - 1. The growth of Avena coleoptile sections in sucrose and auxin solutions is inhibited by various substances which are known to act as dehydrogenase inhibitors. 2. Iodoacetate, which is particularly active in this connection, inhibits all growth at a concentration of 5 x 10(-5) M, but produces only a slight inhibition of oxygen uptake. 3. The growth inhibition by iodoacetate is completely removed by malate and fumarate, and to a lesser extent by succinate and pyruvate. 4. These acids themselves increase the effect of auxin on growth and also increase the respiration of the coleoptile sections, but only if auxin is present. 5. When sections have been soaked in malate or fumarate, the addition of auxin considerably increases the total respiration. Further, the concentration range over which this increase takes place parallels that active in promoting growth. 6. The four-carbon acids provide a respiratory system which is part of the chain of growth processes, and which is in some way catalyzed by auxin. It represents a small but variable fraction of the total respiration. PMID- 19873214 TI - THE EFFECT OF SWELLING ON THE RESPIRATION OF ERYTHROCYTES. AB - 1. Oxygen consumption measurements made while a chicken erythrocyte swells show no increase over the control value. 2. There is no change in the rate of anaerobic glycolysis in beef erythrocytes when they swell. 3. The above statements are true whether the cells swell from a shrunken condition back to the normal volume, or swell from the normal to the hemolytic volume. 4. These data add a further test of the hypothesis that a relationship exists between the cell membrane and its respiratory activity. PMID- 19873215 TI - STUDIES ON PITUITARY LACTOGENIC HORMONE : III. SOLUBILITIES OF SHEEP AND BEEF HORMONES. AB - The solubility of sheep pituitary lactogenic hormone in 0.302 M NaCl at pH 2.02 (solution in HCl) has been determined at room temperature. It showed a constant solubility in the presence of a considerable excess of the solid phase, an indication that the preparation contained but one component. Beef lactogenic hormone showed a constant solubility in distilled H(2)O at 7-8 degrees C in the presence of excess of the solid phase. The salting-out effect of NaCl in acid solution of both beef and sheep hormones has been studied at room temperature. In these studies both preparations behaved as pure substances, but they exhibited differences in solubility, thus indicating a species specificity. PMID- 19873216 TI - EFFECTS OF HEXYLRESORCINOL ON VALONIA. AB - The effects on Valonia of guaiacol and hexylresorcinol are similar but the latter is more effective. Both substances lower or abolish the potassium effect; i.e., the ability of the cell to distinguish electrically between Na(+) and K(+). Both substances change the order of mobilities so that v(Cl) > u(Na) becomes u(Na) > v(Cl) or u(Na) = v(Cl). PMID- 19873217 TI - AN X-RAY AND CRYSTALLOGRAPHIC STUDY OF RIBONUCLEASE. PMID- 19873218 TI - THE FLICKER RESPONSE CONTOUR FOR PHRYNOSOMA (HORNED LIZARD; CONE RETINA). AB - The lizard Phrynosoma, with purely cone retina, provides a simplex flicker response contour (log critical flash intensity as a function of flash frequency). It is well described as a normal probability integral (F - log I). The Phrynosoma curve differs markedly, in higher slope and in higher median intensity level, from that obtained under the same conditions for the turtle Pseudemys, also with entirely cone retina. Other comparisons having a bearing on the duplexity doctrine are discussed. PMID- 19873219 TI - ISOLATION, CRYSTALLIZATION, AND PROPERTIES OF PEPSIN INHIBITOR. AB - A method has been described for the isolation and crystallization of swine pepsin inhibitor from swine pepsinogen. Solubility experiments and fractional recrystallization show no drift in specific activity. The reversible combination of pepsin with the inhibitor was found to obey the mass law. The inhibitor is quite specific, failing to act on other proteolytic and milk clotting enzymes. The inhibitor is destroyed by pepsin at pH 3.5. Chemical and physical studies indicate that the inhibitor is a polypeptide of approximately 5,000 molecular weight with an isoelectric point at pH 3.7. It contains arginine, tyrosine, but no tryptophane and has basic groups in its structure. PMID- 19873220 TI - CHEMICAL PACEMAKERS : III. ACTIVATION ENERGIES OF SOME RATE-LIMITING COMPONENTS OF RESPIRATORY SYSTEMS. AB - 1. In a previous paper it was found that 11,200 calories is obtained for the energy of activation in the oxidation of succinate to fumarate in the presence of crude beef heart extract when succino-dehydrogenase was made the limiting factor. 16,000 calories was obtained with this preparation when cytochrome-cytochrome oxidase was made the limiting factor. In the present paper activation energies of the components of this enzyme system are further studied. 2. Oxidation of p phenylenediamine catalyzed by the extract and known not to involve the dehydrogenase component yields Arrhenius equation plots indicating a pacemaker reaction with a micro of 9,500 calories. 3. An activation energy of 17,500 calories is obtained for the oxidation of succinate to fumarate in the presence of the beef heart extract partially poisoned by pyrophosphate. Evidence is presented that this value corresponds to a link in the respiratory chain other than that of succino-dehydrogenase or cytochrome c-cytochrome oxidase. 4. Addition of a suitable amount of cresyl blue to a beef heart extract reaction mixture, completely inhibited by cyanide, restores the oxidation of succinate to normal in the presence of pure oxygen. In this system, in which the dye is substituted for the oxidase, when the enzyme extract (dehydrogenase) is made the limiting factor, a micro of 18,500 calories is obtained; when cresyl blue is made the limiting factor, the micro value is 22,000 calories. 5. Results of these experiments indicate that energies of activation are associated not with the enzyme as such, but with the particular reaction steps involving them as catalysts. PMID- 19873221 TI - PERMEABILITY OF ERYTHROCYTES TO RADIOACTIVE POTASSIUM. AB - The diffusion coefficients for the exchange of potassium across the membrane of erythrocytes of humans, rats, and rabbits have been determined by the use of artificially radioactive potassium, both into and out of the erythrocytes both in vitro and in vivo. The diffusion coefficients found in minutes(-1) were 0.2 to 0.25 x 10(-3) for human, 0.32 to 0.665 x 10(-3) for rabbits, and 1.0 x 10(-3) for rat erythrocytes. Rabbit erythrocytes appear to be more permeable in vivo. Reasons are advanced to explain the failure of earlier workers to demonstrate appreciable exchange of potassium in erythrocytes. PMID- 19873222 TI - STUDIES ON INVERTEBRATE HEMOGLOBINS (ERYTHROCRUORINS). AB - 1. Two high molecular invertebrate hemoglobins (the erythrocruorins of Lumbricus terrestris and of Nereis virens) as well as the low molecular erythrocruorin of Glycera dibranchiata Ehlers were studied. Their physical chemical properties were compared with those of vertebrate hemoglobin. 2. The hemin of the blood pigment of Glycera dibranchiata Ehlers was shown to be identical with that of vertebrate hemoglobin. 3. The dissociation rates of Glycera and human oxyhemoglobin were measured in the reaction meter of DuBois and t(50) (half time of the reaction) was found to be identical (0.027 second) for the two pigments. The t(50) value for the high molecular Lumbricus erythrocruorin was 0.070 second. 4. The chemical constitution and physical chemical properties of erythrocruorins were compared with those of vertebrate hemoglobin and of hemocyanin. PMID- 19873223 TI - STUDIES ON THE LACTASE OF ESCHERICHIA COLI. AB - A "lactase solution" was prepared from Escherichia coli. The mechanism of its action has been studied and changes in the rate of hydrolysis under various conditions investigated. The hydrolysis of lactose by the enzyme approximates the course of reaction of the integrated Michaelis-Menten equation. One molecule of enzyme combines with one molecule of substrate. E. coli lactase is readily inactivated at pH 5.0, and its optimal activity at 36 degrees C. is reached between pH 7.0 and pH 7.5. The optimal temperature for its action was found to be 46 degrees C. when determinations were carried out after an incubation period of 30 minutes. Its inactivation by heat follows the course of a first order reaction, and the critical thermal increment between the temperatures of 45 degrees C. and 53 degrees C. was calculated to be 56,400 calories per mol. The enzyme is activated by potassium cyanide, sodium sulfide, and cysteine, and irreversibly inactivated by mercuric chloride, silver nitrate, and iodine. After inactivation with copper sulfate partial reactivation is possible, while the slight inhibition brought about by hydrogen peroxide is completely reversible. The possible structure of the active groups of E. coli lactase as compared with other enzymes has been discussed. PMID- 19873224 TI - THE SULFHYDRYL GROUPS OF EGG ALBUMIN. AB - 1. 1 cc. of 0.001 M ferricyanide, tetrathionate, or p-chloromercuribenzoate is required to abolish the SH groups of 10 mg. of denatured egg albumin in guanidine hydrochloride or Duponol PC solution. Both the nitroprusside test and the ferricyanide reduction test are used to show that the SH groups have been abolished. 2. 1 cc. of 0.001 M ferrocyanide is formed when ferricyanide is added to 10 mg. of denatured egg albumin in neutral guanidine hydrochloride or urea solution. The amount of ferricyanide reduced to ferrocyanide by the SH groups of the denatured egg albumin is, within wide limits, independent of the ferricyanide concentration. 3. Ferricyanide and p-chloromercuribenzoate react more rapidly than tetrathionate with the SH groups of denatured egg albumin in both guanidine hydrochloride solution and in Duponol PC solution. 4. Cyanide inhibits the oxidation of the SH groups of denatured egg albumin by ferricyanide. 5. Some samples of guanidine hydrochloride contain impurities which bring about the abolition of SH groups of denatured egg albumin and so interfere with the SH titration and the nitroprusside test. This interference can be diminished by using especially purified guanidine hydrochloride, adding the titrating agent before the protein has been allowed to stand in guanidine hydrochloride solution, and carrying out the nitroprusside test in the presence of a small amount of cyanide. 6. The SH groups of egg albumin can be abolished by reaction of the native form of the protein with iodine. It is possible to oxidize all the SH groups with iodine without oxidizing many of the SH groups beyond the S-S stage and without converting many tyrosine groups into di-iodotyrosine groups. 7. p chloromercuribenzoate combines with native egg albumin either not at all or much more loosely than it combines with the SH groups of denatured egg albumin or of cysteine. 8. The compound of mercuribenzoate and SH, like the compound of aldehyde and SH and like the SH in native egg albumin, does not give a nitroprusside test or reduce ferricyanide but does reduce iodine. PMID- 19873225 TI - ENZYMES IN ONTOGENESIS (ORTHOPTERA) : XIV. THE ACTION OF PROTEINS ON CERTAIN ACTIVATORS OF PROTYROSINASE. AB - 1. Proteins, when added to activators (sodium oleate. Aerosol) of protyrosinase, greatly decrease the degree of activation. 2. Certain proteins adsorbed on activator micelles are markedly affected by temperature and are rendered more sensitive by ultraviolet light. 3. Ideas are expressed as to the possible nature of activating and inhibiting phenomena especially as they relate to the enzyme tyrosinase. PMID- 19873226 TI - THE INFLUENCE OF AGE, HYPOPHYSECTOMY, THYROIDECTOMY, AND THYROXIN INJECTION ON SIMPLE REACTION TIME IN THE RAT. AB - Thyroxin injection with associated increases in metabolic rate does not significantly affect simple reaction time to an electric shock. Hypophysectomy and thyroidectomy with associated decreases in metabolic rate produce a slight decline in reaction speed. Reaction time is long in young animals, probably due to incomplete development of certain integrative and conductive systems; it remains virtually constant between puberty and relatively advanced age when it increases rapidly, probably due to physicochemical changes in the composition of the conducting nervous system. PMID- 19873227 TI - THE RATE OF BACTERIOPHAGE INACTIVATION BY FILTRATES OF ESCHERICHIA COLI CULTURES. AB - 1. The rate of inactivation of an anti-coli phage by filtrates of cultures of the homologous bacteria has been studied. 2. The inactivation rate at 37 degrees C. is proportional to phage concentration and filtrate concentration. 3. At 0 degrees C. the rate of phage inactivation becomes proportional to the square root of the filtrate concentration. 4. A reaction scheme to account for these observations is suggested and discussed. 5. This coli-phage is also inactivated by relatively large concentrations of soluble starch, inulin, gum arabic, and acetylated gum arabic. 6. The inactivation is markedly influenced by salt concentration, being rapid at moderate salt concentrations and slow at high or extremely low salt concentrations. 7. The inactivated phage cannot be regenerated by high salt concentrations, or by soaps. PMID- 19873228 TI - ELECTROPHORETIC STUDIES ON HUMAN RED BLOOD CELLS. AB - 1. The electrophoretic mobility of unhemolyzed human red cells has been determined as a function of ionic strength at approximately constant pH in isotonic mixtures of glucose solution and saline-phosphate buffer solution. 2. Above an ionic strength of about 0.02 the cells behave as particles with a smooth surface of large radius of curvature. Below an ionic strength of about 0.02, changes of the surface occur, probably involving a decrease of charge density and perhaps connected with injury of the surface. 3. The mobility as a function of pH at an ionic strength of 0.172 has been determined for human red cells, for the lipid extract of the cells, and for the stroma protein of the cells. The isoelectric points of cells, lipid, and protein have been found to be about 1.7, 2.6, and 4.7 respectively. 4. The pH-mobility data lead to the conclusion that a red cell surface is composed largely of lipid and dominated by strong acid groups, possibly the phosphoric acid groups of cephalin molecules. PMID- 19873229 TI - A NEW METHOD FOR THE STUDY OF DIFFUSION OF BIOLOGICALLY ACTIVE MATERIAL. AB - A simple diffusion apparatus has been described in which a layer of solution is allowed to diffuse upward into a layer of solvent. Accurate sampling is performed at various heights and the concentration of the samples is determined. The method has been illustrated with a determination of the diffusion constant of crystalline catalase, which was found to be 3.1 x 10(-7) cm.(2)/sec. at 4 degrees C. The method should be especially suited to the study of biological substances endowed with specific activity and which cannot be obtained in pure solution. PMID- 19873230 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : I. THE BEHAVIOR AND PROPERTIES OF COMMERCIAL COLLODION. AB - 1. The electrochemical behavior of membranes prepared from commercial collodion preparations varies widely, some preparations showing very high, other ones very low electrochemical efficiency ("activity"). 2. The electrochemical activity of a collodion membrane depends entirely upon impurities of an acidic nature contained in the collodion used for casting the membrane. 3. The active acidic impurities are substantially due to partial oxidation which occurs in the manufacturing process. Sulfuric acid compounds; e.g., acid sulfuric acid esters play only a minor role, if any. 4. The electrochemical behavior of collodion membranes in solutions of strong electrolytes is decisively dependent upon the acidic groups built permanently into the collodion surfaces. Preferential ion adsorption plays only a minor, if any, role. PMID- 19873231 TI - MELANOPHORE BANDS AND AREAS DUE TO NERVE CUTTING, IN RELATION TO THE PROTRACTED ACTIVITY OF NERVES. AB - 1. When appropriate chromatic nerves are cut caudal bands, cephalic areas, and the pelvic fins of the catfish Ameiurus darken. In pale fishes all these areas will sooner or later blanch. By recutting their nerves all such blanched areas will darken again. 2. These observations show that the darkening of caudal bands, areas, and fins on cutting their nerves is not due to paralysis (Brucke), to the obstruction of central influences such as inhibition (Zoond and Eyre), nor to vasomotor disturbances (Hogben), but to activities emanating from the cut itself. 3. The chief agents concerned with the color changes in Ameiurus are three: intermedin from the pituitary gland, acetylcholine from the dispersing nerves (cholinergic fibers), and adrenalin from the concentrating nerves (adrenergic fibers). The first two darken the fish; the third blanches it. In darkening the dispersing nerves appear to initiate the process and to be followed and substantially supplemented by intermedin. 4. Caudal bands blanch by lateral invasion, cephalic areas by lateral invasion and internal disintegration, and pelvic fins by a uniform process of general loss of tint equivalent to internal disintegration. 5. Adrenalin may be carried in such an oil as olive oil and may therefore act as a lipohumor; it is soluble in water and hence may act as a hydrohumor. In lateral invasion (caudal bands, cephalic areas) it probably acts as a lipohumor and in internal disintegration (cephalic areas, pelvic fins) it probably plays the part of a hydrohumor. 6. The duration of the activity of dispersing nerves after they had been cut was tested by means of the oscillograph, by anesthetizing blocks, and by cold-blocks. The nerves of Ameiurus proved to be unsatisfactory for oscillograph tests. An anesthetizing block, magnesium sulfate, is only partly satisfactory. A cold-block, 0 degrees C., is successful to a limited degree. 7. By means of a cold-block it can be shown that dispersing autonomic nerve fibers in Ameiurus can continue in activity for at least 6(1/2) hours. It is not known how much longer they may remain active. So far as the duration of their activity is concerned dispersing nerve fibers in this fish are unlike other types of nerve fibers usually studied. PMID- 19873232 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : IV. CRITICAL INTENSITIES FOR VISUAL FLICKER, MONOCULAR AND BINOCULAR. AB - Comparison of monocular and binocular critical flash intensities for recognition of flicker, using a centrally fixated square image subtending ca. 6.13 degrees on a side (white light), shows that for the cone segment of the response contour the inflection point of the probability integral correlating flash frequency F (for symmetrical flicker) and log mean critical flash intensity I(m) is with the binocular measurements exactly intermediate between those for each eye separately. This does not mean that in general the data are intermediate; they are not; the binocular asymptotic F(max.) agrees with or lies above the greater one of the two uniocular curves. The entire contour must be considered for valid intercomparisons, as is also true if homologous curves for different observers are to be compared. For the measurements in the predominantly rod region the binocular data are more or less intermediate. The rod curves result, however, from the integrative interplay of rod and cone effects for which the intrinsic curves overlap. The resultant rod curve as measured is determined by the partial inhibition of rod effects by cone effects, and by the summation of the remaining rod contributions with those labelled cone in origin. It is pointed out that in this respect, as in others, it is desirable to consider the roles of retinal area, and location, from the standpoint of integration of neural effects. These phenomena are essentially independent of the light-time fraction and of the spectral (lambda) quality of the light used. For binocular, as for uniocular excitation, the normal probability summation provides an efficient general description, under diverse conditions of size and location of retinal image, wave length composition of light, light-time cycle-fraction, and kind of animal. It is pointed out that this is the only function abstractly likely to exhibit this kind of efficiency. That a summation of veritable effects independently generated by simultaneous, symmetrical uniocular excitation does occur in the recognition of flicker is specifically demonstrated by the fact that for a given mean critical flash intensity the associated variation is lower for binocular than for either or the average of the single-eyed presentations,-and in the ratio not statistically different from 1:1.41; the relative scatter of the binocular indices of dispersion is also reduced below the uniocular. Since the mean variation of the critical intensity is statistically in a constant ratio to I(m), in appropriately homogeneous series, independent for example of the brightness level and of the light-time fraction, this signifies an essential doubling of the effectiveness (potential) of each of the elements concerned in the discrimination of flicker when binocular excitation is concerned, although the total number of these elements is only slightly or not at all affected. The potential in question is not exclusively correlated with subjective brightness-at-fusion, which is, however, increased with binocular regard. PMID- 19873233 TI - TRANSVERSE IMPEDANCE OF THE SQUID GIANT AXON DURING CURRENT FLOW. AB - The change in the transverse impedance of the squid giant axon caused by direct current flow has been measured at frequencies from 1 kc. per second to 500 kc. per second. The impedance change is equivalent to an increase of membrane conductance at the cathode to a maximum value approximately the same as that obtained during activity and a decrease at the anode to a minimum not far from zero. There is no evidence of appreciable membrane capacity change in either case. It then follows that the membrane has the electrical characteristics of a rectifier. Interpreting the membrane conductance as a measure of ion permeability, this permeability is increased at the cathode and decreased at the anode. PMID- 19873234 TI - MEMBRANE POTENTIAL OF THE SQUID GIANT AXON DURING CURRENT FLOW. AB - The squid giant axon was placed in a shallow narrow trough and current was sent in at two electrodes in opposite sides of the trough and out at a third electrode several centimeters away. The potential difference across the membrane was measured between an inside fine capillary electrode with its tip in the axoplasm between the pair of polarizing electrodes, and an outside capillary electrode with its tip flush with the surface of one polarizing electrode. The initial transient was roughly exponential at the anode make and damped oscillatory at the sub-threshold cathode make with the action potential arising from the first maximum when threshold was reached. The constant change of membrane potential, after the initial transient, was measured as a function of the total polarizing current and from these data the membrane potential is obtained as a function of the membrane current density. The absolute value of the resting membrane resistance approached at low polarizing currents is about 23 ohm cm.(2). This low value is considered to be a result of the puncture of the axon. The membrane was found to be an excellent rectifier with a ratio of about one hundred between the high resistance at the anode and the low resistance at the cathode for the current range investigated. On the assumption that the membrane conductance is a measure of its ion permeability, these experiments show an increase of ion permeability under a cathode and a decrease under an anode. PMID- 19873235 TI - THE CHLOROPHYLL-PROTEIN COMPOUND OF THE GREEN LEAF. AB - 1. Aqueous extracts of spinach and Aspidistra leaves yield highly opalescent preparations which are not in true solution. Such extracts differ markedly from colloidal chlorophyll in their spectrum and fluorescence. The differences between the green leaf pigment and chlorophyll in organic solvents are shown to be due to combination of chlorophyll with protein in the leaf. 2. The effect of some agents on extracts of the chlorophyll-protein compound has been investigated. Both strong acid and alkali modify the absorption spectrum, acid converting the compound to the phaeophytin derivative and alkali saponifying the esterified groups of chlorophyll. Even weakly acid solutions (pH 4.5) denature the protein. Heating denatures the protein and modifies the absorption spectrum and fluorescence as earlier described for the intact leaf. The protein is denatured by drying. Low concentrations of alcohol or acetone precipitate and denature the protein; higher concentrations cause dissociation liberating the pigments. 3. Detergents such as digitonin, bile salts, and sodium desoxycholate clarify the leaf extracts but denature the protein changing the spectrum and other properties. 4. Inhibiting agents of photosynthesis are without effect on the absorption spectrum of the chlorophyll-protein compound. 5. The red absorption band of chlorophyll possesses the same extinction value in organic solvents such as ether or petroleum ether, and in aqueous leaf extracts clarified by digitonin although the band positions are different. Using previously determined values of the extinction coefficients of purified chlorophylls a and b, the chlorophyll content of the leaf extracts may be estimated spectrophotometrically. 6. It was found that the average chlorophyll content of the purified chloroplasts was 7.86 per cent. The protein content was 46.5 per cent yielding an average value of 16.1 parts per 100 parts of protein. This corresponds to a chlorophyll content of three molecules of chlorophyll a and one of chlorophyll bfor the Svedberg unit of 17,500. It is suggested that this may represent a definite combining ratio of a and b in the protein molecule. PMID- 19873236 TI - THE ACTION OF SODIUM DODECYL SULFATE ON THE CHLOROPHYLL-PROTEIN COMPOUND OF THE SPINACH LEAF. AB - 1. Sodium dodecyl sulfate (SDS) attacks the chlorophyll-protein compound modifying its protein properties and absorption spectrum. 2. In the presence of SDS, chlorophyll is quantitatively converted to phaeophytin; i.e., magnesium is removed from the molecule. This reaction, measured spectrophotometrically, proceeds at a rate directly proportional to the hydrogen ion concentration. At constant pH, the rate is proportional to the SDS concentration until a maximum rate is achieved. 3. The chlorophyll or phaeophytin (depending on the pH) remains attached to the protein, since the prosthetic group cannot be separated by ultrafiltration, dialysis, or fractional precipitation. 4. This suggests that the magnesium plays no part in binding chlorophyll to the split protein fragments, but may be concerned in binding the larger units, since the metal becomes extremely labile when the protein is split. PMID- 19873237 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : V. CYTOCHROME OXIDASE ACTIVITY IN THE EGGS OF ARBACIA PUNCTULATA. AB - 1. An enzyme capable of oxidizing reduced cytochrome c (i.e. a cytochrome oxidase) has been obtained from Arbacia eggs. In 0.02 M hydroquinone, the cytochrome oxidase was half activated at a cytochrome c concentration of approximately 4 x 10(-6)M. The concentration of the cytochrome oxidase was found to be nearly the same in unfertilized and fertilized eggs, the amount of the enzyme-as measured by means of its activity toward cytochrome c as a representative substrate-being more than sufficient to account for the highest rate of oxygen utilization yet observed in the intact, living, fertilized eggs, and of the same order as that in certain rat tissues. 2. The Arbacia cytochrome oxidase was strongly inhibited by carbon monoxide in the dark, the inhibition being almost completely reversed by light. The inhibition constant was not greatly altered by variation in the concentration of cytochrome c or the concentration of hydroquinone used as reductant for the cytochrome c, having a value of 3 to 5 under the conditions used. The inhibition constant was about 2 with p-phenylenediamine as reductant for the cytochrome c, but apparently had the surprisingly low value of about 0.5 with 0.02 M cysteine as reductant. 3. The cytochrome oxidase was completely inhibited by sufficiently high concentrations of sodium cyanide, sodium azide, and sodium sulfide. It was also completely inhibited in 0.6 M sodium chloride. It was not inhibited by two inhibitors of copper containing enzymes, 8-hydroxyquinoline and sodium diethyldithiocarbamate. It was also not significantly inhibited by 2,4-dinitrothymol, 2,4-dinitro-o cyclohexylphenol, phenylurethane, 5-isoamyl-5-ethylbarbituric acid, or iodoacetic acid. 4. Quantitative examination of the fertilized eggs showed that cytochrome c, if present at all, occurred in a concentration of less than 2 micrograms per gram of wet fertilized Arbacia eggs. On the basis of these data and those of Fig. 2, above, it seems safe to conclude that cytochrome c cannot carry a significant fraction of the oxygen consumption of fertilized Arbacia eggs. It was also found that, in contrast to similar preparations from certain other animal tissues, the Arbacia cytochrome oxidase preparation displayed no succinic dehydrogenase activity when tested manometrically in the presence of excess cytochrome c. 5. Extending previously reported (3) experiments with other inhibitors, the effects of sodium azide and sodium sulfide on the respiration and cell division of fertilized Arbacia eggs were determined, the eggs being initially exposed to the reagents 30 minutes after fertilization at 20 degrees C. With either reagent cleavage was completely blocked by a concentration of reagent which reduced the respiration to approximately 50 per cent of the normal level. 6. On the basis of certain theoretical considerations regarding the possible mechanism of action of cyanide and other respiratory inhibitors it is suggested that a fraction of the respiration apparently concerned with supplying energy for division processes in the fertilized Arbacia egg may be keyed into the respiratory cycle through a carrier having a somewhat higher potential than those which carry the larger portion of the egg respiration. The theory is also employed in an effort to resolve a number of hitherto apparently paradoxical observations regarding the effects of cyanide, azide, and carbon monoxide on cell respiration. PMID- 19873238 TI - A NEW FORM OF DIFFRACTOMETER. AB - A simple diffractometer is described, in which monochromatic light is focused on a pinhole, rendered parallel, and passed through a film of red cells or other objects the size of which is sought. The diffraction patterns are photographed on special plates, and the positions of the first minimum and of the first maximum are subsequently found by the use of a simplified microphotometer. The method gives substantially the same results for red cell radius and (calculated) volume as do other standard methods. PMID- 19873239 TI - THE SIMPLEX FLICKER THRESHOLD CONTOUR FOR THE ZEBRA FINCH. AB - The flicker response contour has been determined, with equality of light-dark time ratio, for the diurnal bird the Australian zebra finch. This bird has only cones in the retina. The curve of log critical intensity as a function of flash frequency is simplex, a normal probability integral. In this respect it is like that for other vertebrates not exhibiting visual duplexity. The parameters of the curve most closely approach those for the turtle Pseudemys (extrapolated to about the same temperature); it is not improbable that the approximation of these two curves would be less close for other values of the light-time fraction. Some points of interpretive visual theory are discussed in relation to the present measurements. PMID- 19873240 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : V. FLASH DURATION AND CRITICAL INTENSITY FOR RESPONSE TO FLICKER. AB - The relation between flash duration and mean critical intensity (white light) for threshold recognition of visual flicker, as a function of flash frequency, was investigated by means of measurements at five values of the light-time fraction: 0.10, 0.25, 0.50, 0.75, 0.90, with flash frequencies of the interrupted beam ranging from 2 to 60 per second. A square area, 6.1 x 6.1 degrees , centrally fixated) was viewed monocularly; the discriminometer used provides automatically an artificial pupil 1.8 mm. in diameter. Except for the slight day-to-day fluctuation in the magnitudes of the parameters, the data for the observer used are shown to form an essentially homogeneous group. As for other animals tested, the F - log I(m) curve is enlarged and moved toward lower flash intensities as the light-time fraction is decreased. The high intensity segments of the duplex curves are fitted by normal probability integrals for which F(max). and the abscissa of inflection are rectilinear functions of t(L)(t(L) + t(D)), with opposite slopes. The third parameter, (sigma'(log I), is invariant. The low intensity segments are composites, their shapes determined by the summation of the lower part of the high intensity curve with an overlapping low intensity population of effects. Both the rising and the declining branches of this latter assemblage suffer competitive partial suppression by the effects in the high intensity population. The detailed analysis shows that these results are consistent with the theory of the central, rather than peripheral, location of the dynamically recognizable elements in the determination of flicker. PMID- 19873241 TI - STUDIES IN THE PHYSIOLOGY OF FUSARIA. THE RESPIRATORY AND FERMENTATIVE MECHANISMS. AB - 1.Fusarium tricothecoides was selected for a study of the respiratory and fermentative activities of Fusaria. "Resting cell" suspensions were investigated by the Barcroft manometric technique. 2. The results of the investigation indicate clearly that the mechanism of endogenous metabolism (respiration) is distinct from the exogenous mechanism (fermentation). Anaerobically no significant CO(2) production is apparent without added substrate. In the presence of glucose the anaerobic CO(2) evolution is practically equal to the added CO(2) evolved aerobically in the presence of added glucose. Low concentrations of iodoacetate or fluoride selectively poison the exogenous mechanism but do not affect the endogenous mechanism. Alcohol is not produced in the course of endogenous metabolism, but is produced in the presence of added glucose. 3. A study of the metabolism of the organism throughout its entire growth phase from 1 to 7 days has been made. 4. The ability of suspensions of Fusarium sp. H., obtained by growth on a variety of common substrates, to attack a large number of carbon sources with the production of exogenous CO(2) was determined. It is found that organisms grown on glucose will attack only glucose, mannose, and fructose, but none of the common intermediary metabolites except pyruvic acid. Organisms grown on galactose attack galactose, as well as the other hexoses, indicating an adaptive mechanism. 5. An identical mechanism for the dissimilation of glucose, mannose, and galactose is indicated since no additive effects with these substrates were observed. Growths on non-hexose carbon sources attack glucose slightly under the experimental conditions with the evolution of CO(2), but do not attack any other substrate. This would indicate a residual glucose dissimilating mechanism in all growths investigated. 6. Striking similarities between the general metabolism of resting suspensions of Fusarium sp. H. and resting suspensions of yeast cells are apparent. PMID- 19873242 TI - ANAEROBIC GLYCOGENOLYSIS IN THE MUSCLES OF RANA PIPIENS LIVING AT LOW TEMPERATURES. AB - 1. A considerable proportion of R. pipiens caught in the spring and stored without food for several weeks at about 4 degrees C. had gastrocnemii that did not break down glycogen when they contracted anaerobically to complete exhaustion. A smaller number of the same muscles did not produce lactate. 2. There was no evident relation between failure to break down glycogen and the glycogen content of such muscles, some of which had more than 500 mg. of glycogen per 100 gm. of tissue. 3. The hypothesis of Meyerhof and his followers that aerobic contraction of frog muscles may at times take place with sources of energy other than carbohydrate is therefore extended to include anaerobic contraction. PMID- 19873243 TI - SOME EFFECTS OF IODINE AND OTHER REAGENTS ON THE STRUCTURE AND ACTIVITY OF TOBACCO MOSAIC VIRUS. AB - 1. Denatured tobacco mosaic virus has a number of SH groups corresponding to its total sulfur content of 0.2 per cent. The SH groups were estimated by titration with ferricyanide, tetrathionate, and p-chloromercuribenzoate in guanidine hydrochloride solution and by reduction of the uric acid reagent in urea solution. 2. The SH groups of tobacco mosaic virus or their precursors can be abolished by reaction of the native form of the virus with iodine. 3. Tobacco mosaic virus whose SH groups have been oxidized beyond the S-S stage by iodine but whose tyrosine groups have not been converted into di-iodotyrosine groups still retains its normal biological activity as shown by the number of lesions it causes on Nicotiana glutinosa plants and by the characteristic disease produced in Turkish tobacco plants. 4. The inoculation of Turkish tobacco plants with active virus whose SH groups have been abolished by iodine results in the production of virus with the normal number of SH groups. 5. If enough iodine is added to tobacco mosaic virus or if the iodine reaction is carried out at a sufficiently high temperature, then the tyrosine groups are converted into di iodotyrosine groups and the virus is inactivated. 6. Tobacco mosaic virus can be almost completely inactivated by iodoacetamide under conditions under which iodoacetamide reacts with few if any of the protein's SH groups. 7. Tobacco mosaic virus is not inactivated by dilute p-chloromercuribenzoate. PMID- 19873244 TI - THE EFFECT OF SONIC VIBRATIONS ON PHAGE, PHAGE PRECURSOR, AND THE BACTERIAL SUBSTRATE. AB - 1. A nickel tube magneto-striction oscillator of 320 watts output producing sonic vibrations of 9,300 cycles per second frequency is described. Certain structural innovations contribute to operating efficiency and permit more convenient exposure of test materials than in earlier types. 2. The rate of phage inactivation by sonic waves proceeds logarithmically with time and serves as a satisfactory measure of energy output during operation of the generator. The curve for phage inactivation taking place in the presence of homologous staphylococci follows that for phage alone but soon reaches a plateau after which no further loss of activity is noted. In general higher concentrations of bacteria more effectively inhibit phage destruction than do lower concentrations. 3. Cells that have attained a resting state after a preliminary phase of rapid growth normally have the capacity of inducing a very rapid and marked increase in [phage] when added to phage. This effect has been attributed to the presence of intracellular phage precursor. The store of phage precursor in activated cells is destroyed by sonic waves in about 30 minutes. The number of cells (plate count) shows no reduction until after the precursor is entirely inactivated. 4. Attempts to extract phage precursor from activated staphylococci by exposing the cells to sonic vibrations were unsuccessful. PMID- 19873245 TI - EFFECTS OF NITROBENZENE AND BENZENE ON VALONIA. AB - The effects of nitrobenzene and of benzene resemble those of guaiacol and of hexylresorcinol. The P.D. changes in a positive direction and then in a negative direction. The latter change may bring the P.D. back to the starting point with guaiacol and hexylresorcinol but with nitrobenzene and benzene this is not always the case. The positive potential change produced by nitrobenzene and benzene may be antagonized to some extent by ammonia. Nitrobenzene and benzene raise the electrical resistance and this is antagonized to some extent by ammonia. The results afford a further illustration of the important fact that the behavior of inorganic ions can be changed by organic substances. The apparent mobility of Na(+) is increased and that of K(+) decreased by nitrobenzene and benzene (as is also the case with guaiacol and hexylresorcinol). PMID- 19873246 TI - THE INFLUENCE OF HOST RESISTANCE ON VIRUS INFECTIVITY AS EXEMPLIFIED WITH BACTERIOPHAGE. PMID- 19873247 TI - SULFHYDRYL GROUPS OF EGG ALBUMIN IN DIFFERENT DENATURING AGENTS. AB - 1. The reaction between ferricyanide and egg albumin in solutions of urea, guanidine hydrochloride, and Duponol has been investigated. 2. In neutral medium ferricyanide oxidizes all the SH groups of egg albumin that give a color reaction with nitroprusside. In neutral medium ferricyanide appears to react only with the SH groups of egg albumin. The quantity of ferrocyanide formed can accordingly be considered the equivalent of the number of SH groups in egg albumin detectable with nitroprusside. 3. In solutions of urea, guanidine hydrochloride, and Duponol sufficiently concentrated so that all the egg albumin present is denatured, the same number of SH groups are found-equivalent to a cysteine content of 0.96 per cent. 4. In denaturation of egg albumin loss of solubility (solubility not in presence of the denaturing agent, but solubility examined in water at the isoelectric point) and appearance of reactive SH groups are integral parts of the same process. As denaturation proceeds in urea, SH groups are liberated only in the egg albumin with altered solubility and in this albumin the maximum number of SH groups is liberated. In a molecule of egg albumin either all of its SH groups that give a test with nitroprusside are liberated or none of them are. PMID- 19873248 TI - SULFHYDRYL GROUPS IN FILMS OF EGG ALBUMIN. AB - 1. The same number of SH groups reduces ferricyanide in surface films of egg albumin as in albumin denatured by urea, guanidine hydrochloride, Duponol, or heat, provided the ferricyanide reacts with films while they still are at the surface and with the denatured proteins while the denaturing agent (urea, heat, etc.) is present. 2. The SH groups of a suspension of egg albumin made by clumping together many surface films react with ferricyanide in the same sluggish and incomplete manner as do the groups in egg albumin denatured by concentrated urea when the urea is diluted or in albumin denatured by heat when the solution is allowed to cool off. 3. The known change in configuration of the egg albumin molecule when it forms part of a surface film explains why SH groups in the film react with ferricyanide whereas those in native egg albumin do not. In the native egg albumin molecule groups in the interior are inaccessible to certain reagents. A film is so thin that there are no inaccessible groups. 4. Because of the marked resemblance in the properties of egg albumin in surface films and of egg albumin after denaturation by the recognized denaturing agents, it may be supposed that the same fundamental change takes place in denaturation as in film formation indeed, that film formation is one of the numerous examples of denaturation. This would mean that in general the SH groups of denatured egg albumin reduce ferricyanide and react with certain other reagents because they are no longer inaccessible to these reagents. PMID- 19873249 TI - THE COURSE OF ROD DARK ADAPTATION AS INFLUENCED BY THE INTENSITY AND DURATION OF PRE-ADAPTATION TO LIGHT. AB - An increase in the degree of light adaptation causes a decrease in the slope of the subsequent rod dark adaptation function and a displacement of the function to the right on the time axis. Over a wide range, these changes occur to the same extent whether the increase in the degree of light adaptation is produced by raising the intensity or by prolonging the exposure. Within these limits, the Bunsen-Roscoe reciprocity law applies to the intensity and duration of pre exposure. Over a still wider range, dark adaptation has the same course following brief exposure to a bright light as it has following prolonged exposure to a dim light, provided the degree of light adaptation is the same in both instances (as indicated by identical initial dark adaptation thresholds). PMID- 19873250 TI - THE EFFECT OF DETERGENTS ON THE CHLOROPHYLL-PROTEIN COMPOUND OF SPINACH AS STUDIED IN THE ULTRACENTRIFUGE. AB - 1. The chlorophyll-protein compound of the spinach leaf has been studied in the air-driven ultracentrifuge using the Svedberg light-absorption method, and a direct-reading refractive index method. 2. When the untreated extracts are centrifuged at low speeds, the green protein sediments with a purely random spread of particle sizes confirming the fact that the protein is not in true solution. 3. In the presence of digitonin, bile salts, and sodium desoxycholate, the extracts are clarified. These detergents split the chlorophyll from the protein and the protein itself shows a sedimentation constant of 13.5 x 10(-13) equivalent to a molecular weight of at least 265,000 as calculated from Stokes' law. This probably represents the minimum size of the protein in native form. 4. Sodium dodecyl sulfate, a detergent which also clarifies the leaf extracts, shows a different behavior. The prosthetic group remains attached to the protein but the protein is split into smaller units. In 0.25 per cent SDS, S(20) is 2.6 x 10( 13) over a pH range of 5 to 9, although at the acid pH chlorophyll is converted to phaeophytin. In 2.5 per cent SDS, S(20) is 1.7 x 10(-13) suggesting a further splitting of the protein. 5. No differences in behavior were found for the various chloroplast pigments. PMID- 19873251 TI - FORMATION OF AUXIN IN YEAST CULTURES. AB - We have found far more auxin in the culture media of bakers' yeast than was obtained by Kogl and Kostermans from the cells themselves. The production of auxin by yeast cells resembles the formation observed in other organisms such as Rhizopus and Rhizobium which also form auxins in their culture media. The auxin yield was found to increase with the concentration of sucrose and to decrease with the concentration of peptone. An inverse relation with the rate of cell multiplication was observed. Enlarged and elongated cells appeared only in those media which contained considerable amounts of auxin. The total auxin yield in the various cultures was found to be directly proportional, below pH 5, to the hydrogen ion concentration. Thus, it was proposed that certain growth conditions favor the breakage of the link between auxin and its protein carrier (Skoog and Thimann) 1940) and consequently accelerate the rate of excretion of auxin into the growth medium. PMID- 19873252 TI - LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON. AB - Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 microf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one fifth henry. PMID- 19873253 TI - THE INFLUENCE OF ROENTGEN RAYS UPON THE NITROGEN FIXATION BY AZOTOBACTER. AB - The influence of graded x-ray doses upon nitrogen fixation and respiration by Azotobacter was studied by means of the Warburg method. It was found that nitrogen fixation decreases approximately linearly with increasing x-ray doses. Respiration in contrast is affected only indirectly through some inhibition of cell multiplication. Small doses of x-ray often produce a slight and transient increase in the rate of oxygen uptake. PMID- 19873254 TI - A PERFUSING SOLUTION FOR THE LOBSTER (HOMARUS) HEART AND THE EFFECTS OF ITS CONSTITUENT IONS ON THE HEART. AB - 1. All inorganic perfusing solution for the heart of the lobster Homarus americanus, to allow prolonged normal beating (20 hours or more) must agree closely with the inorganic composition of the serum, which varies differentially with that of the environmental sea water. 2. All of the chief inorganic ions of the serum are necessary-Na, K, Ca, Mg, Cl, and SO(4); the critical numbers of the ions being 100, 3, 5, 2-3, 116, and 1-2 respectively. Absence of Mg and SO(4) will be tolerated for several hours. 3. The pH of the solution must agree with that of the serum within 0.2. 4. The osmotic pressure of the solution must agree with that of the serum within 15 per cent. 5. Beating of the heart will continue for several hours on improperly balanced solutions but changes in frequency, tone, or amplitude will occur. Hearts adapted to such solutions will show different responses to physical and chemical stimuli of the solution than those perfused on properly balanced solutions. 6. Arrest in systole is caused by isotonic NaCl, KCl, LiCl, and urea, and arrest in diastole by isotonic CaCl(2), MgCl(2), NaBr, NaI, MgSO(4), and glucose. 7. Lithium cannot replace sodium; neither can bromide or iodide replace chloride ions. PMID- 19873255 TI - X-RAY AND CRYSTALLOGRAPHIC STUDIES OF PLANT VIRUS PREPARATIONS : I. INTRODUCTION AND PREPARATION OF SPECIMENS II. MODES OF AGGREGATION OF THE VIRUS PARTICLES. PMID- 19873256 TI - X-RAY AND CRYSTALLOGRAPHIC STUDIES OF PLANT VIRUS PREPARATIONS. III. AB - These papers give an account of an optical and x-ray examination of preparations of plant virus substances isolated by Bawden and Pirie, in particular of those of tobacco mosaic disease. They open with a historical survey of the work, indicating the order in which new phenomena were discovered. The subsequent treatment is divided into three parts: I. Introduction and preparation of specimens. II. Modes of aggregation of virus particles. III. (1) The structure of the particles. (2) Biological implications. Part I, after an historical introduction, describes the method of preparation, from solutions of the virus, of optically oriented specimens of different concentrations. For their examination special x-ray apparatus was developed, in particular cameras working with very low angles and capable of indicating spacings up to 1000 A. In Part III, Section 1 deals with the x-ray evidence on the internal structure of the particles. Even in solution, they have an inner regularity like that of a crystal. Virus preparations are thus in a sense doubly crystalline. Closer analysis reveals that the x-ray patterns are not directly comparable to those of a crystal as many of the reflections do not obey Bragg's law, but can be understood on the theory of gratings of limited size. The structure seems to consist of sub-units of the dimensions of approximately 11 A cube, fitted together in a hexagonal or pseudohexagonal lattice of dimensions-a = 87 A, c = 68 A. Contrary to what earlier observations seemed to indicate, the particle seems to be virtually unchanged by drying and must therefore contain little water. There are marked resemblances with the structure of both crystalline and fibrous protein, but the virus structure does not belong to any of the classes hitherto studied. There are indications that the inner structure is of a simpler character than that of the molecules of crystalline proteins. Part III, Section 2 contains a comparative study of the optical and x-ray examinations of three strains of tobacco mosaic virus, two of cucumber disease virus, two of potato virus X, and the virus of bushy stunt disease of tomato. In the last case x-ray measurement confirmed the deduction from its cubic crystal habit that it was composed of spherical rather than long particles, and showed that these had a diameter when dry of 276 A and were arranged in a body-centred cubic close packing. This single example is sufficient to show that the elongated particle form which gives rise to all the anomalous physical properties of the other viruses studied is of no essential biological importance. The similarity and differences observed between the physical properties of these preparations run closely parallel to their clinical and serological classification. Finally, the biological implications of these results are discussed together with possible applications of the new methods of examination to the study of colloid and biological problems. PMID- 19873257 TI - RECTIFICATION AND INDUCTANCE IN THE SQUID GIANT AXON. AB - Previous measurements have shown that the electrical properties of the squid axon membrane are approximately equivalent to those of a circuit containing a capacity shunted by an inductance and a rectifier in series. Selective ion permeability of a membrane separating two electrolytes may be expected to give rise to the rectification. A quasi-crystalline piezoelectric structure of the membrane is a plausible explanation of the inductance. Some approximate calculations of behavior of an axon with these membrane characteristics have been made. Fair agreement is obtained with the observed constant current subthreshold potential and impedance during the foot of the action potential. In a simple case a formal analogy is found between the calculated membrane potential and the excitability defined by the two factor formulations of excitation. Several excitation phenomena may then be explained semi-quantitatively by further assuming the excitability proportional to the membrane potential. Some previous measurements and subthreshold potential and excitability observations are not consistent with the circuit considered and indicate that this circuit is only approximately equivalent to the membrane. PMID- 19873258 TI - THE EFFECT OF CALCIUM AND OTHER IONS ON THE AUTOCATALYTIC FORMATION OF TRYPSIN FROM TRYPSINOGEN. AB - Crystalline trypsinogen is completely transformed into trypsin by means of trypsin in the presence of calcium salts. The process follows the course of a pure autocatalytic unimolecular reaction. In the absence of calcium salts, the autocatalytic formation of trypsin from trypsinogen is complicated by the transformation of part of the trypsinogen into an inert protein which cannot be changed into trypsin by any known means. Salts increase or decrease the rate of both reactions so that the ultimate amount of trypsin formed varies with the nature and concentration of the salt used. With equivalent concentrations of salt the percentage of trypsinogen changed into trypsin is greatest in the presence of calcium ion followed in order by strontium; magnesium and sodium; rubidium, ammonium, lithium, and potassium; caesium and barium. With the anions the largest percentage of trypsinogen transformed into trypsin was found with the acetate, sulfate, oxalate, citrate, tartrate, fluoride, and chloride ions followed in order by bromide, nitrate, and iodide. The formation of inert protein is completely suppressed by concentrations of calcium ion greater than 0.02 M. PMID- 19873259 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : II. THE ACTIVATED COLLODION MEMBRANE. AB - 1. The electrochemical behavior (concentration potential, anomalous osmosis, etc.) of collodion membranes is due to its acidic impurities. These impurities determine the possible charge density of the collodion-aqueous solution interfaces. This (possible) charge density is believed to be identical with the base exchange capacity of the interfaces under consideration. 2. The collodion preparations commercially available at present are too pure to yield membranes of sufficient activity for electrochemical membrane investigations. Crude collodion, a product which is only partially purified, shows considerable electrochemical activity because of its content of acidic impurities. 3. The inactive commercial collodion preparations can readily be activated by oxidation by virtue of the fact that oxidation increases the number of dissociable groups (carboxyl groups) on the collodion. The oxidation method of activating collodion may be applied to membranes as such as well as to collodion in bulk. 4. The recommended oxidizing agents are sodium and calcium hypochlorite and sodium hypobromite. A further group of effective and recommended activating agents are solutions of strong alkalies. Alkalies cause a complicated decomposition of nitrocellulose with the formation of nitrites (and probably other nitrous compounds). These nitrites act upon the collodion as oxidizing agents, thus causing activation. 5. Detailed descriptions of tested oxidation procedures for highly dried membranes, porous membranes, and bulk collodion are given in the text, the optimum conditions being different in the three cases. 6. Collodion membranes oxidized as such show a much higher electrochemical activity than any previously described. Highly dried membranes after oxidation give concentration potentials which approach the thermodynamically possible maximum more closely than any given in the literature. Porous membranes after oxidation show greatly increased concentration potentials and yield much greater electroosmosis when a current is passed through. These effects are reflected in the enormous magnification of the extent of anomalous osmosis. 7. The behavior of the porous membranes toward nonelectrolytes changes but little on oxidation. The volume of such membranes, as well as their per cent water content (pore space), remains constant within the limits of experimental error. From this observation and studies on the rate of filtration, it is concluded that the geometrical structure of membranes is but little changed on oxidation. 8. Collodion oxidized in bulk likewise yields very active membranes. Dried membranes prepared from activated bulk collodion consistently yield concentration potentials which approach the thermodynamically possible maximum very closely and are appreciably higher than any previously reported. Porous membranes prepared from bulk oxidized collodion show a degree of electrochemical activity surpassing anything described for the most active commercial collodion preparations. However, these membranes are less active than those oxidized as such. 9. Membranes prepared from different collodion preparations which behave fairly uniformly towards nonelectrolytes but very differently towards electrolyte solutions become similar in their behavior towards electrolytes after oxidation. 10. The geometrical structures of membranes prepared from different collodion preparations are essentially identical. The differences in their behavior towards electrolytes are due entirely to the electrochemical factor; i.e., the charge density at the water/collodion interface. 11. Certain general aspects of the foregoing experimental results are discussed briefly. PMID- 19873260 TI - ELECTRIC POTENTIAL AND ACTIVITY OF CHOLINE ESTERASE IN THE ELECTRIC ORGAN OF ELECTROPHORUS ELECTRICUS (LINNAEUS). AB - 1. If the concentration of choline esterase is determined at different sections from the head to the caudal end of the electric organ of Electrophorus electricus (Linneaus) S-like curves are obtained. These curves are essentially the same as those which show the number of electric discs per centimeter and the E.M.F. per centimeter. 2. In the organ of Hunter the concentration of the enzyme does not differ from that in the adjacent parts in the main organ. This again coincides with the observations on the number of plates per centimeter in this organ. 3. The concentration of the enzyme was determined in different parts of the brain and the spinal cord and compared with that in a gold fish. The concentrations here are of the same order, but in the spinal cord of the eel the concentration is even lower than in the gold fish. As the cell bodies of the nerves innervating the electric organ in the spinal cord, these results do not lend support to the assumption of a special concentration of the enzyme in these nerves. 4. In the muscles adjacent to the electric organ an enzyme concentration has been found which is of the order of that in the electric tissue itself and much higher than in ordinary striated muscles. 5. The suitability of the organ for the preparation of enzyme solutions has been investigated and compared with that of the organ of Torpedo. PMID- 19873261 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : VI. WAVE-LENGTH AND FLASH DURATION IN FLICKER. AB - For spectral regions associated with violet, blue, green, and red the relation between mean critical flash intensity I(m) for visual flicker and the flash frequency F is modified as already found with white light when the light time fraction t(L) in the flash cycle is changed. For a square image 6.13 degrees on a side, foveally fixated, the "rod" and "cone" contributions to the duplex contour are analyzed in the way already used for white. It is pointed out that several customary qualitative criteria for cone functioning do not necessarily give concordant results. The analysis shows that the three parameters of the probability summations giving the "rod" and "cone" curves are changed independently as a function of wave-length composition of the light, and of the light time fraction. The correlation of these changes, and of those found in the associated variability functions, can be understood in terms of differences in (1) the numbers of neural units potentially excitable and (2) in the numbers of elements of neural effect obtained from them. In a multivariate situation of this kind it is necessary to compare intensities of luminous flux required to activate half the total population of potentially available elements when this total size is held constant for the different conditions. The results of this comparison, for the filtered lights used, are discussed in relation to certain aspects of excitation vs. wave-length. The problem is a general one, arising where the effects produced as a function of a particular variable are concerned. In the distinction between (1) units excited and (2) the actions they produce may be found the clue for the curious fact that with certain wave-lengths the critical intensities are lower than for white. The extension of the observations to other parts of the retina may be expected to further this analysis. PMID- 19873262 TI - DETERMINATION OF CERTAIN AMINO ACIDS IN CHYMOTRYPSINOGEN, AND ITS MOLECULAR WEIGHT. AB - 1. A preparation of chymotrypsinogen, obtained from Dr. M. Kunitz, was analyzed for sulfur, the sulfur amino acids, tyrosine, and tryptophane. 2. The protein sulfur of chymotrypsinogen was accounted for as methionine, cysteine, and cystine. 3. A method is presented for calculating the minimum molecular weight of a protein from the distribution of the sulfur amino acids. In the case of chymotrypsinogen, the calculated minimum molecular weight was found to be the actual molecular weight. 4. The molecular weight of chymotrypsinogen is 36,700 by amino acid analysis as compared to 36,000 by osmotic pressure measurements of Kunitz and Northrop. Chymotrypsinogen contains per mol 17 atoms of sulfur, 3 residues of methionine, 4 of cysteine, 10 of half-cystine (i.e. 5 S-S linkages), 6 of tyrosine, and 10 of tryptophane. 5. The tryptophane content of chymotrypsinogen (5.51 per cent) is the highest of any protein so far on record. 6. Chymotrypsinogen contains no reactive SH groups, although it yields cysteine on hydrolysis. This may be due either to preformed but unreactive SH groups or to S-X groups. The term S-X group is used to denote the substitution of the sulfhydryl hydrogen by a constituent X; hydrolysis yields SH groups: S-X + HOH = SH + X-OH. PMID- 19873263 TI - THE ACTIVITY OF PERIPHERALLY STORED NEUROHUMORS IN CATFISHES. AB - 1. Adrenalin when mixed with olive oil 1:100 and injected subcutaneously into a catfish will produce a marked pale spot and a general blanching of the whole fish. The general blanching will disappear in about a day. The pale spot may last 3 to 4 weeks. 2. Injections of adrenalin in oil 1:1000 to 1:10,000,000 cause the formation of only pale spots in catfishes. Adrenalin in oil 1:100,000,000 has no effect on the fish's color. 3. Acetylcholine, though ordinarily more powerful than adrenalin, when mixed with oil is effective only in high concentrations 1:20 to 1:100. It then produces clusters of moderately dark spots. 4. The pale spot on a catfish due to adrenalin in oil may be temporarily obliterated by intermedin. It will return of itself, and this process may be repeated a number of times. The same is true of the dark spots produced by acetylcholine in oil when subjected to adrenalin. These observations indicate the subcutaneous storage of both adrenalin and acetylcholine in oil. 5. In the natural color changes in catfishes the nervous neurohumors, probably also adrenalin and acetylcholine, appear both to be stored in the fish's lipoids and to serve thus as a means of lenghthening the times of initial color responses till these stores of neurohumors are exhausted. PMID- 19873264 TI - INACTIVATION OF PEPSIN BY IODINE : II. ISOLATION OF CRYSTALLINEl-MONO IODOTYROSINE FROM PARTIALLY IODINATED PEPSIN. AB - 1. Pepsin solutions were iodinated at pH 5.0-6.0 until 10-20 per cent of the activity was lost and 1/20 (0.7 per cent) of the saturating amount of iodine had been introduced into the protein molecule. After alkaline hydrolysis 65 per cent of the original iodine was accounted for as mono-iodotyrosine although only 42 per cent was isolated as a crystalline product. No evidence was obtained to support the possibility that any group other than tyrosine in pepsin was iodinated. 2. Some of the properties of the crystalline l-mono-iodotyrosine were determined and compared to those of di-iodotyrosine. 3. One iodinated pepsin preparation was crystallized. The crystal form was the same as that of the original pepsin. A solubility curve of the crystals demonstrated that it was very different from pepsin and had nearly constant solubility. PMID- 19873265 TI - THE OCCURRENCE AND DISTRIBUTION OF ATROPINESTERASE, AND THE SPECIFICITY OF TROPINESTERASES. AB - Atropinesterase was found to exist in approximately one out of every four rabbits, and no relation could be observed between the incidence of the enzyme and season, sex, color, age, or weight. The occurrence of the enzyme was also shown to be unrelated to that of cholinesterase. The distribution of atropinesterase in the blood and organs of rabbits was studied; the animals devoid of the enzyme in their blood contained no demonstrable activity in any of the organ extracts tested. The presence of atropinesterase in frog liver, and its absence from the serum, has been confirmed. Hydrolysis of homatropine, but not atropine, by guinea pig liver was observed, while the serum was without action on either of the compounds. On this basis the possibility arises that guinea pig liver contains a homatropinesterase enzyme separate from atropinesterase. It was shown that lack of atropinesterase activity in certain rabbits is not likely to be due to the presence of a naturally occurring inhibitor. It has been demonstrated that contrary to previous indications neither fresh egg white nor yolk possess atropinesterase activity. The specificity of tropinesterases was investigated and evidence was presented for the possible existence of two distinct enzymes, cocainesterase and tropacocainesterase. PMID- 19873266 TI - THE INFLUENCE OF PROTEINS ON THE REACTIVATION OF YEAST INVERTASE. AB - 1. Acid-inactivated yeast invertase could not be regenerated in the presence of the proteolytic enzymes trypsin, pepsin, and chymotrypsin. 2. Certain foreign proteins of non-enzymatic nature partially inhibited the reactivation of acid inactivated invertase. 3. Certain proteins as gelatin, lacto-globulin, and carbohydrate-free horse crystalbumin did not prevent the reactivation of invertase at all. 4. Highly purified reactivated invertase was shown to exhibit an effect typical of original native invertase; that is, acceleration of its activity in presence of foreign protein at pH 3.0. 5. Native invertase was not digested by trypsin and chymotrypsin. 6. The addition of trypsin and chymotrypsin to reactivating invertase did not affect the invertase which had already reverted to the active form, but prevented further reactivation of inactive invertase. PMID- 19873267 TI - OSMOTIC PROPERTIES OF THE EGG CELLS OF THE OYSTER (OSTREA VIRGINICA). AB - INVESTIGATIONS OF THE OSMOTIC PROPERTIES OF OYSTER EGGS BY A DIFFRACTION METHOD FOR MEASURING VOLUMES HAVE LED TO THE FOLLOWING CONCLUSIONS: 1. The product of cell volume and osmotic pressure is approximately constant, if allowance is made for osmotically inactive cell contents (law of Boyle-van't Hoff). The space occupied by osmotically inactive averages 44 per cent of cell volume. 2. Volume changes over a wide range of pressures are reversible, indicating that the semipermeability of the cell during such changes remains intact. 3. The kinetics of endosmosis and of exosmosis are described by the equation, See PDF for Equation, where dV is rate of volume change; S, surface area of cell, (P-P(e)), the difference in osmotic pressure between cell interior and medium, and K, the permeability of the cell to water. 4. Permeability to water during endosmosis is 0.6micro(3) of water per minute, per square micron of cell surface, per atmosphere of pressure. The value of permeability for exosmosis is closely the same; in this respect the egg cell of the oyster appears to be a more perfect osmometer than the other marine cells which have been studied. Permeability to water computed by the equation given above is in good agreement with computations by the entirely different method devised by Jacobs. 5. Permeability to diethylene glycol averages 27.2, and to glycerol 20.7. These values express the number of mols x 10(-15) which enter per minute through each square micron of cell surface at a concentration difference of 1 mol per liter and a temperature of 22.5 degrees C. 6. Values for permeability to water and to the solutes tested are considerably higher for the oyster egg than for other forms of marine eggs previously examined. 7. The oyster egg because of its high degree of permeability is a natural osmometer particularly suitable for the study of the less readily penetrating solutes. PMID- 19873268 TI - ON THE PRODUCTION AND USE OF PERMANENTLY ALTERED STRAINS OF YEAST FOR STUDIES OF IN VIVO METABOLIC ORGANIZATION. PMID- 19873269 TI - THE VISUAL SYSTEMS OF EURYHALINE FISHES. AB - 1. The retinas of all marine fishes so far examined except the Labridae, and of all terrestrial vertebrates contain the rhodopsin system alone; those of fresh water fishes the porphyropsin system alone. In the present paper the visual systems of a number of euryhaline fishes are examined-fishes capable of existence in a wide range of salinities, though usually restricted in spawning either to the sea (catadromous) or to fresh water (anadromous). 2. The retinas of the anadromous salmonids (brook trout, rainbow trout, and chinook salmon) contain mixtures of the rhodopsin and porphyropsin systems, predominantly the latter. The retinas of the catadromous eel and the killifish also contain mixtures of both systems, but in reverse proportions. The retinas of the anadromous white perch and alewife contain the porphyropsin system alone. 3. There is therefore an extensive parallelism between the salinity relations of these animals and the composition of their visual systems. All of them possess predominantly or exclusively the visual system commonly associated with the environment in which the fish spawns. 4. These patterns are fixed genetically, and are to a first approximation independent of the history of the individual. They may represent transitional stages in the evolutionary migration of fishes to and from the sea. The presence of both types of visual system in the retinas of some euryhaline fishes incidentally satisfies one formal requirement of two-component color vision. PMID- 19873270 TI - THE EFFECT OF TEMPERATURE AND OF LYSIN CONCENTRATION ON THE ACCELERATION OF HEMOLYSIS. AB - The acceleration of saponin hemolysis by benzene, indol, and nonyl alcohol has been investigated as a function of temperature, and it has been found that these accelerators have negative temperature coefficients. This points to their being concentrated at the cell surface, and to the surface being the seat of their accelerating action. It is shown that the accelerating power of indol (used as a typical accelerator) is constant so long as the lysin in the system is capable of producing lysis per se, but that the acceleration falls off when only sublytic concentrations are present. The relations are expressed in a series of equations, and explained in terms of the reactions among the accelerator, the lysin, and the membrane component, which breaks down in spots, rather than uniformly, when lysis occurs. The argument involves a consideration of the idea that a monolayer of lysin at the cell surface is necessary for hemolysis, of Abramson's hypothesis of "key spots" on the surface, of the rate of escape of hemoglobin from the hemolyzing cell, and of the results of electrophoretic and impedance measurements. The existing theory of the kinetics is extended by introducing the idea of a variation in resistance from point to point in the cell membrane; in this form it describes the situation so far as is at present known, and shows that the results of the various methods of investigation are consistent with each other. The only idea discussed which seems to have little foundation is that lysis is determined by the formation of a monolayer of lysin at the cell surface; when this occurs, it must do so only as a special case. Finally, a semi quantitative description of the frequency distribution of the resistances in the membrane is derived from existing data. The variation in resistance which it is necessary to assume is quite small, as might be expected in the case of a membrane with a regular ultra-structure. PMID- 19873271 TI - ANALYTICAL DIFFUSION OF INFLUENZA VIRUS AND MOUSE ENCEPHALOMYELITIS VIRUS. AB - Analytical diffusion has been applied to a study of influenza A virus in mouse lung, influenza A virus in the extra-embryonic fluids of the chick, and mouse encephalomyelitis virus in mouse brain. The results from influenza in mouse lung suggested that about 99 per cent of the infectivity was present in particles 200 mmicro in diameter, and 1 per cent in particles 6 mmicro in diameter. The results from influenza in extra-embryonic fluids indicated that the preparation was inhomogeneous and that the smallest virus units were about 6 mmicro in diameter. The results from mouse encephalomyelitis virus indicated that the preparation was also inhomogeneous, with 10 per cent of the infectivity in particles about 15 mmicro in diameter. It has been suggested that in virus preparations normal colloidal particles can act as carriers of much smaller virus units. PMID- 19873272 TI - P(32) UPTAKE BY NUCLEI. AB - 1. A method for isolating nuclei in quantity from mammalian tissues is described. 2. The rate of uptake of radioactive phosphorus by nuclei is found to be quite rapid. The phosphorus was shown not to be taken up by exchange. 3. Nuclei of tumors accumulate more radioactive phosphorus than normal liver nuclei. This was shown to be due to mitotic activity and not a form of metabolism peculiar to tumor cells. 4. The specific activities of nuclei and cytoplasm are compared. 5. 60 to 70 per cent of the nuclear radioactive phosphorus is present as nucleoprotein from 1 hour to 5 days after it is administered. In the lymphoma nuclei 90-95 per cent of the phosphorus is in the nucleoprotein fraction from 1-5 days after it is administered. 6. The specific activities of the nucleoprotein, lipid, and acid-soluble fractions of liver and tumor nuclei are compared. 7. From the rate of P(32) uptake by nuclei it is calculated that a new lymphoma nucleus is synthesized on the average once every 27 hours. This is in agreement with the observed rate of growth of the tumor. 8. In the lymphoma nucleus it is calculated that 7 x 10(4) molecules of tetranucleotide are synthesized per second. 9. Irradiation with 200 r. x-rays alters the distribution of P(32) in the lymphoma cell, markedly increasing the concentration in the nucleus shortly after irradiation. The P(32) concentration in the cytoplasm decreases with time after irradiation. It is suggested that the altered distribution is correlated with the inhibition of mitosis produced by the x-rays. 10. Continual synthesis of nucleoprotein takes place even in nuclei of cells which do not undergo mitosis. PMID- 19873273 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : VII. THE FLICKER RESPONSE FUNCTION OUTSIDE THE FOVEA. AB - The several parameters of the flicker response contour (F - log I) are considered as a function of wave-length composition (white, blue, and red) and light-time fraction, for an extra-foveal region (monocular, temporal retina). These data are compared with those secured for the same image area centrally fixated at the fovea. The systematic changes in the parameters are shown to be in rational relation to other relevant excitability data. Since for two retinal regions the primary contours are quite different, the systematic nature of the behavior of the parameters in the two cases is a real test of the power of the analysis proposed. Theoretical interpretation is required to deal with the properties of sets of performance contours under systematically varied conditions, and cannot rely simply on the comparison of (for example) two contours under the same arbitrary conditions at two retinal locations. In particular it is emphasized that a qualitative separation must be made of the two factors of (a) number of units and (b) the frequencies of their actions, before the wave-length problem can be dealt with effectively. PMID- 19873274 TI - PHOTOXIDATION PROCESSES IN PLANTS. AB - 1. Photoxidation in leaves is measured by exposing them to light in an atmosphere free from carbon dioxide but containing varied percentages of oxygen. 2. Photoxidation is observed in living leaves as well as in dead ones and in plant juices. Its rate is only slightly enhanced by feeding the leaves with sugar, but the respiration (autoxidation) becomes considerably enlarged during the exposure and the following dark period. 3. The rate of photoxidation rises slower than linearly with light intensity; its dependence upon oxygen pressure has the character of a saturation curve. Oxygen saturation occurs at about 6/10 of an atmosphere of oxygen. A similar dependence on oxygen pressure has been observed by Gaffron for photoxidation in vitro sensitized by chlorophyll adsorbed on proteins and by Warburg for the depression of the saturation rate of photosynthesis. 4. The influence of photoxidation on photosynthesis and the chemical kinetics of photoxidation are discussed. PMID- 19873275 TI - THE MAGNETIC BEHAVIOR OF CATALASE. AB - The magnetic moment of catalase is 4.6 +/- 0.3, nearly the same as that of ferric hemoglobin hydroxide. If the moment be due to electron spin alone without orbital contribution, 3 free electrons would give rise to 3.9 magnetons. PMID- 19873276 TI - THE VISUAL SYSTEM AND VITAMINS A OF THE SEA LAMPREY. AB - The porphyropsin-vitamin A(2) cycle has been found heretofore only in the retinas of bony fishes capable of existence in fresh water. Cyclostomes, due to their primitive and isolated phylogenetic position, might be expected to possess the rhodopsin-vitamin A(1) cycle common to marine elasmobranchs, almost all marine teleosts, and all terrestrial vertebrates so far examined. Yet the anadromous sea lamprey, Petromyzon marinus, possesses primarily the porphyropsin system, like an anadromous teleost. This observation greatly extends the phylogenetic association of vitamin A(2) with the capacity for freshwater existence. Compared with freshwater and anadromous teleosts, the lamprey retina contains the porphyropsin system in extremely low concentration. The remaining eye tissues, like the retina, contain both vitamins A(1) and A(2), the latter greatly predominant. The livers of larval and adult lampreys, however, appear to contain vitamin A(1) alone. This situation also is not without teleost precedent, since the carp and certain anadromous salmonids display similar reversals of vitamin A pattern in the liver and eye tissues. PMID- 19873277 TI - REVIVAL OF MAMMALIAN SPERM AFTER IMMERSION IN LIQUID NITROGEN. AB - 1. A wide variety of procedures was used to test the motility of mammalian sperm after plunging them into liquid nitrogen at -195 degrees C. and later rapidly warming them to 35 degrees C. by plunging them into a suitable balanced and isotonic medium. 2. Using seminal fluid sperm from the same human donor, maximal numbers of motile sperm survived vitrification when the samples were (a) very fresh, (b) untreated with plasmolysing solutions, (c) plunged into the refrigerant in the form of a foam. The maximum yield of motile human sperm recoverable from the liquid nitrogen was 50 per cent. Since in this sample only 75 per cent of the sperm were alive before immersion, 67 per cent of the living sperm survived vitrification. 3. Experiments with sperm from 31 rabbits were made with a variety of conditions of pretreatment to obtain maximal yields of recoverable, motile sperm after vitrification by liquid nitrogen. (a) A consistent recoverable yield of about 0.5 per cent was obtained when the untreated suspension of sperm was smeared on cellophane and partially dried in air before immersing in liquid nitrogen. (b) On a few out of many occasions plasmolysis for several minutes with hypertonic Ringer solution gave a recoverable yield of 0.1 per cent as did (c) pretreatment with hypertonic Ringer and butyric acid. PMID- 19873278 TI - THE RADIOACTIVITY OF POTASSIUM FROM HUMAN SOURCES. AB - A comparison of the radioactivity of potassium from human and commercial sources indicates that the radioactive isotope K(40) is probably 1 or 2 per cent less abundant in human potassium. PMID- 19873279 TI - SOME FACTORS WHICH INFLUENCE THE OXIDATION OF SULFHYDRYL GROUPS. AB - 1. Cyanide inhibits the oxidation of the SH groups of cysteine and denatured egg albumin by the uric acid reagent. 2. At pH 4.8 cysteine is oxidized by the uric acid reagent and by ferricyanide in the presence but not in the absence of added copper sulfate. 3. In neutral solution, the uric acid reagent oxidizes the SH groups of denatured egg albumin in the presence of urea but not in the presence of alkyl sulfate or in the absence of denaturing agents. 4. Ferricyanide oxidizes the SH groups of neutral denatured egg albumin even in the presence of alkyl sulfate or, if precautions are taken to avoid aggregation, in the absence of denaturing agents. 5. In acid solution, ferricyanide does not oxidize the SH groups of denatured egg albumin completely. The oxidation is more complete, however, in the presence of urea than in the presence of alkyl sulfate, and more complete in the presence of guanidine hydrochloride than in the presence of urea. 6. The uric acid reagent which does not oxidize the SH groups of neutral denatured but unhydrolyzed egg albumin in the absence of denaturing agents does, under the same conditions, oxidize the SH groups of egg albumin partially hydrolyzed by pepsin. 7. At pH 4.8 in alkyl sulfate solution ferricyanide oxidizes the SH groups of digested egg albumin more completely than the SH groups of denatured but undigested egg albumin. PMID- 19873280 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : VIII. THE FORM OF THE FLICKER CONTOUR. AB - Flicker response curves (man) obtained with images formed entirely within the fovea are like those secured with lower animals having only one general class of retinal receptors. They are normal probability integrals (F vs. log I(m)), and the properties of their parameters agree with those for visually simplex animals and for the "cone" portions of contours exhibiting visual duplexity. By several different procedures, involving experimental modifications of the "cone" curve, the "rod" part of the typical human duplex curve can be obtained free from overlapping by the extrapolated "cone" curve. It then has the probability integral form which the lower segment does not directly exhibit when combined with "cone" effects. These results are discussed with reference to the statistical nature of the fundamental form of the flicker contour and to the interpretation of duplex curves produced by the neural integration of two independently modifiable groups of sensory effects. PMID- 19873281 TI - THE WAVELENGTH SENSITIVITY FUNCTION FOR THE ZEBRA FINCH. AB - With lights of different spectral compositions filtered from a white, the flicker response contours for the zebra finch are found to exhibit the same general kind of relationship between flicker excitation and wavelength as is found in the case of man ("cone" contours), with the same filters. The flicker contours for the zebra finch are simplex; the retina contains no rods. On a relative energy scale, with a flash cycle of fixed light-time percentage (10 per cent) the curve for yellow almost coincides with that for the white, the curve for red lies at much higher intensities, and the curves for blue-green and violet fall below that for the white by amounts increasing in that order. The maxima to which the curves rise and the slope constants are very nearly the same for all the spectral regions. For the bird the blue was a little less efficient, the green a little more efficient, and the red very much less efficient than in the case of man. It was deduced that in the retina of this diurnal bird the number of red oil globules should be comparatively small and that most of the globules should be greenish yellow. This was confirmed by direct examination. PMID- 19873282 TI - COUNTERACTING THE RETARDING AND INHIBITORY EFFECTS OF STRONG ULTRAVIOLET ON FUCUS EGGS BY WHITE LIGHT. AB - 1. Strong dosages (20,000-50,000 ergs per mm.(2)) of ultraviolet light, predominantly of the wave-length 2537 A, greatly retard and inhibit the development of rhizoids in Fucus eggs irradiated at about 8 hours after fertilization. 2. If white light shines on the eggs after the irradiation by ultraviolet is terminated, the white light causes a considerable degree of recovery from the retarding and inhibiting effects. 3. If strong white light shines on the eggs during the ultraviolet irradiation, its effect is even more marked in protecting the cells from the damaging effects of the ultraviolet. PMID- 19873283 TI - THE ACTIVITY OF YEAST INVERTASE AS A FUNCTION OF OXIDATION-REDUCTION POTENTIAL. AB - The activity of yeast invertase as a function of oxidation-reduction potential has been investigated using a large number of oxidants and reductants. The activity is constant over the range of E(h) from -270 to +600 mv., but above E(h) = +600 mv. there is a sharp decrease in activity reaching 0 at E(h) = +1,000 mv. The inhibiting action of strong oxidants is upon the enzyme rather than on the substrate and appears to be essentially irreversible Experiments indicate that the inhibiting action of strong oxidants on invertase is primarily related to their high oxidation-reduction potential rather than to a specific toxic action unrelated to E(h). The effects of oxidation-reduction potential upon invertase activity are independent of the purity of the enzyme, since they are the same for commercial invertases, fresh bakers' yeast, powdered bakers' yeast, brewers' yeast, and highly purified invertase. Possible mechanisms involved in the inactivation of invertase by oxidants are discussed. PMID- 19873284 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : III. THE BASE EXCHANGE PROPERTIES OF COLLODION. AB - 1. Theoretical considerations lead to the conclusion that dissociable acidic groups present to a varying extent in different collodion preparations determine the electrochemical behavior of membranes cast from these preparations. It is further reasoned that the base exchange capacity of the collodion surfaces is the true quantitative measure of the abundance of the dissociable groups. 2. The concept of base exchange capacity and the base exchange method are discussed. The conditions which allow a purposeful application of the latter are stated. 3. The base exchange properties of a number of fibrous collodion preparations of different origins and after various types of treatment, having widely varying electrochemical activities, are determined. 4. With the chemical (titration) and physical (electrometric) methods employed, no regular correlation can be found between electrochemical activity and base exchange. The base exchange capacity which is necessary to cause even great electrochemical activity of collodion is extremely small. 5. Measurable to high base exchange capacity always seems to be associated with good or high electrochemical activity; but base exchange capacity too low to be definitely measurable with the available methods may be found with collodion preparations of high as well as with preparations of low electrochemical activity. 6. The bearing of these results upon the problem of the spatial and electrical structure of the collodion membrane is indicated briefly. PMID- 19873285 TI - STIMULATION OF CELLS BY INTENSE FLASHES OF ULTRAVIOLET LIGHT. AB - A study has been made of the effect of sudden intense flashes of ultraviolet light, acting on a wide variety of cells and tissues, with special reference to stimulation. The flashes are obtained by a high voltage condenser discharge through a quartz mercury vapor sterilamp, using the method of Rentschler. The lethal effect of a single such discharge is widespread among unicellular organisms. Medullated nerves and whole muscles are not visibly stimulated, because of absorption by connective tissue. Single muscle fibers undergo immediate contracture in 50 per cent of the experiments. Nitella cells are stimulated, the effect depending on the dosage. Weak ultraviolet flashes slow or stop cyclosis reversibly. Strong flashes stop cyclosis reversibly with the appearance of a local or a propagated action potential. Very strong flashes kill the Nitella cells. The effect of single flashes on myonemes, oscillatory movement, ameboid movement, cilia, flagella, and bioluminescence is described in the text. PMID- 19873286 TI - A SIMPLE TIME WEIGHT RELATION OBSERVED IN WELL NOURISHED RATS. AB - The equation See PDF for Equation fits the growth of well nourished rats from weaning on. The general properties of the equation, and particularly its relation with the law of relative growth, are discussed. PMID- 19873287 TI - PURIFICATION AND CRYSTALLIZATION OF DIPHTHERIA ANTITOXIN. AB - Purified preparations of diphtheria antitoxin have been obtained by digestion of the toxin-antitoxin complex with trypsin, followed by fractional precipitation with ammonium sulfate. The various fractions obtained in this way are all 90 per cent or more precipitated by diphtheria toxin but combine with different quantities of the toxin. The fraction precipitated between 0.33 and 0.5 saturated ammonium sulfate is homogeneous by electrophoresis and ultracentrifuge but does not have constant solubility. A small amount of a more soluble fraction has been obtained which does have constant solubility and satisfies the criteria of a pure protein. This protein crystallizes readily in poorly formed thin plates. It is very unstable and reverts to a less soluble non-crystallizable form. It has a sedimentation constant of 5.7 x 10(-13) and a molecular weight of 90,500. It has an antitoxic value of 700-900 flocculation units per mg. protein nitrogen and has an antitoxic value by the protection test of about 700 units per mg. protein nitrogen. The precipitation range of the purified antitoxin with purified toxin is much wider than that with crude preparations. PMID- 19873288 TI - PURIFIED DIPHTHERIA ANTITOXIN IN THE ULTRACENTRIFUGE AND IN THE ELECTROPHORESIS APPARATUS. AB - ULTRACENTRIFUGATION STUDIES OF DIPHTHERIA ANTITOXIN SHOWED THAT: 1. Purified antitoxin of high activity obtained from horse plasma without enzymatic treatment has exactly the same sedimentation constant as the globulin fraction obtained in a similar way from normal horse plasma s(20) (water) = 6.9 x 10(-13). 2. Purified antitoxin obtained with trypsin digestion of the toxin-antitoxin complex has a sedimentation constant of s(20) (water) = 5.5 +/- 0.1 x 10(-13), a diffusion constant of D(20) (water) = 5.7(6) x 10(-7), and a molecular weight of about 90,000. Electrophoresis experiments demonstrated that: 1. The trypsin-purified antitoxin has an isoelectric point not far from pH 7.0. 2. The reversible spreading noticed at about pH 7.3 cannot be attributed to heterogeneous preparation. 3. The large increase in the gamma-globulin fraction occurring during immunization consists either of antitoxin of various degrees of activity or of some inert protein in addition to the antitoxin. PMID- 19873289 TI - THE REVERSIBLE INACTIVATION OF TOBACCO MOSAIC VIRUS BY CRYSTALLINE RIBONUCLEASE. AB - The reversible inactivation of tobacco mosaic virus by crystalline ribonuclease is reported. Studies on the effect of time of standing on the amount of inactivation, and on the effect of dilution and repeated high speed centrifugation on the recovery of virus activity, and the preparation of an insoluble virus-enzyme complex show that the inactivation is brought about at least in part by a combination between virus and enzyme. The significance of the fact that ribonuclease has no detectable effect on the virus nucleic acid when the latter is in combination with protein in the form of virus is discussed with respect to the structure of the virus. PMID- 19873290 TI - AN ELECTROPHORETIC STUDY OF MIXTURES OF OVALBUMIN AND YEAST NUCLEIC ACID. AB - Electrophoretic patterns of mixtures of ovalbumin and yeast nucleic acid indicate that the constituents migrate independently of each other in buffer solutions of 0.1 ionic strength and at pH values somewhat higher than the isoelectric point of the protein. In the isoelectric region, however, the patterns from the two sides of the channel exhibit asymmetries that can be explained by assuming the existence in the mixture of appreciable concentrations of a reversibly dissociable complex between the components. Formation of this complex is favored by increasing concentrations of the components and decreasing ionic strength. At pH values below the isoelectric point partial precipitation of the complex occurs. The patterns obtained from each side of the channel in the electrophoresis of a mixture of two components, which form a dissociable complex, indicate only two boundaries, aside from the delta and epsilon effects. One of these is a normal boundary whose displacement is proportional to the mobility of a component that has separated from the mixture. In the other boundary, however, dissociation of the complex occurs and consequently the displacement of this boundary corresponds to the mobility of neither component nor to that of the complex. Moreover, the areas under the refractive index gradient curves are not proportional to the stoichiometric concentrations of the components. However, equations are developed with the aid of which an electrophoretic analysis of the mixture is possible. This analysis requires the use of data from the patterns of both channels. PMID- 19873291 TI - A CYCLOSCOPIC STUDY OF THE HUMAN ELECTROENCEPHALOGRAM. AB - Cycloscopic analyses of a series of electroencephalograms obtained from a mixed group of individuals, clinically classified as normal, schizophrenic, and "frank" epileptic, show the following characteristics: 1. A rather closely regulated potential oscillation which remains predominant throughout the sample of record under study. 2. Associated with this dominant cycle other definite anharmonic cycles are clearly evident. These associated cycles may operate in intermittent sequences or simultaneously with the dominant cycle. Subjects with "atypical" epilepsy show an apparently characteristic spread of low intensity cycles. PMID- 19873292 TI - QUANTITATIVE CHEMICAL STUDIES ON HEMOLYSINS : I. THE ESTIMATION OF TOTAL ANTIBODY IN ANTISERA TO SHEEP ERYTHROCYTES AND STROMATA. AB - 1. Total antibody in hemolysins may be estimated from the nitrogen added to sheep stromata suspensions. 2. The method is applied to a number of hemolysins and a correlation, valid to within 20 per cent, established between hemolytic titer and total antibody. 3. When stromata combine with antibody in the presence of guinea pig complement they may take up at least 80 per cent of their weight of complement combining component(s). PMID- 19873293 TI - THE MECHANISMS OF X-RAY EFFECTS ON CELLS. AB - Irradiation of Tradescantia microspores does not increase subsequent sensitivity to x-rays as measured by the frequency of induced chromosomal aberrations curing the nuclear cycle. The slight decrease in sensitivity is to be expected because acentric fragments are less sensitive than the centric chromosomes. The physiological effects of x-rays appear to be of minor importance in causing injury or death of individual cells, and most of the deleterious effects can be attributed to "direct hits" which produce chromosomal alterations. In the reaction of tissues to x-rays the physiological effects may play a more important part. PMID- 19873294 TI - THE ROLE OF CARBONIC ANHYDRASE IN CERTAIN IONIC EXCHANGES INVOLVING THE ERYTHROCYTE. AB - 1. The acceleration by bicarbonates of the swelling and hemolysis of erythrocytes in solutions of ammonium salts, first reported by Orskov, is strikingly dependent upon carbonic anhydrase, being almost abolished by inhibitors of this enzyme such as KCN and sulfanilamide, and under suitable conditions being enhanced by its addition to the external solution. This behavior gives support to the theory of "catalyzed diffusion" as an explanation of the Orskov effect. 2. The inhibitory effects of both sulfanilamide and KCN seem to be capable of complete reversal on washing the erythrocytes in isotonic salt solutions. The full effect of KCN appears almost instantly; that of sulfanilamide requires a period measured in seconds, or possibly even in minutes, to reach its maximum, the delay presumably being due to the slower penetration of the erythrocyte by this substance. Under favorable conditions the effect of concentrations of sulfanilamide of a few hundredths of a milligram per cent can be demonstrated. No similar effects have been obtained with sulfapyridine. 3. Bicarbonates also have a "catalytic" effect on the response of the internal pH of erythrocytes to changes in that of their surroundings. The resulting volume changes of the cell, which otherwise frequently require many minutes for their completion, may take place within a few seconds in the presence of low concentrations of bicarbonates. At a given pH value the effect of the latter substances is chiefly on the rate of the change and only to a minor extent on its magnitude. It may be further accelerated under appropriate conditions by the addition to the cell suspension of carbonic anhydrase, and can be almost abolished by KCN and by sulfanilamide. 4. Volume changes of erythrocytes associated with exchanges of Cl' for SO(4)'' ions are greatly accelerated by low concentrations of bicarbonates, this effect being likewise dependent upon carbonic anhydrase. There is some evidence that in this case the exchange takes place, at least in part, in two steps: Cl' for HCO(3)' and HCO(3)' for SO(4)''. PMID- 19873295 TI - VISUAL ACUITY AND ILLUMINATION IN DIFFERENT SPECTRAL REGIONS. AB - The relation between visual acuity and illumination was measured in red and blue light, using a broken circle or C and a grating as test objects. The red light data fall on single continuous curves representing pure cone vision. The blue light data fall on two distinct curves with a transition at about 0.03 photons. Values below this intensity represent pure rod vision. Those immediately above represent the cooperative activity of rods and cones, and yield higher visual acuities than either. Pure cone vision in this intensity region is given by central fixation (C test object). All the rest of the values above this transition region represent pure cone vision. In blue light the rod data with the C lie about 1.5 log units lower on the intensity axis (cone scale) than they do in white light, while with the grating they lie about 1.0 log unit lower than in white light. Both the pure rod and cone data with the C test object are precisely described by one form of the stationary state equation. With the grating test object and a non-limiting pupil, the pure rod and cone data are described by another form of the same equation in which the curve is half as steep. The introduction of a small pupil, which limits maximum visual acuity, makes the relation between visual acuity and illumination appear steeper. Determinations of maximum visual acuities under a variety of conditions show that for the grating the pupil has to be larger, the longer the wavelength of the light, in order for the pupil not to be the limiting factor. Similar measurements with the C show that when intensity discrimination at the retina is experimentally made the limiting factor in resolution, visual acuity is improved by conditions designed to increase image contrast. However, intensity discrimination cannot be the limiting factor for the ordinary test object resolution because the conditions designed to improve image contrast do not improve maximum visual acuity, while those which reduce image contrast do not produce proportional reductions of visual acuity. PMID- 19873296 TI - SOME PROPERTIES OF CRYSTALLINE GUINEA PIG HEMOGLOBIN. AB - 1. Guinea pig hemoglobin crystals are shown to be readily permeable to ferricyanide and hydrosulfite, indicating the presence of interstices between the protein molecules of the crystal. 2. The assumptions of closest hexagonal packing and of spherical molecules of HbO(2) lead to a crystal lattice having interstices between the molecules which represent 25 per cent by volume of the crystal. These spaces would be just large enough at their narrowest junctures to permit ferricyanide ions to diffuse through them. If these spaces were filled with water, then 20 per cent by weight of the crystals would be water. 3. The hemes are on the surface of the globin and are arranged facing the interstices between the molecules of the lattice. 4. The binding of O(2) in HbO(2) is stronger in the crystal lattice than in solution. 5. Hydrogen, activated with colloidal palladium, will not reduce ferrihemoglobin except in the presence of a redox dye. 6. In the reduction of O(2) by activated hydrogen, H(2)O(2) can be demonstrated by the formation of the H(2)O(2)-ferrihemoglobin spectrum. PMID- 19873297 TI - THE PHOTOSYNTHETIC EFFICIENCY OF PHYCOCYANIN IN CHROOCOCCUS, AND THE PROBLEM OF CAROTENOID PARTICIPATION IN PHOTOSYNTHESIS. AB - The absorption spectra of the principal pigment components extracted from Chroococcus cells have been measured, and their sum compared with the absorption of a suspension of living cells. The agreement was sufficiently close so that it was concluded the absorption spectra of the extracted and separated pigment components could be used to obtain estimates of the relative absorption of the various components in the living cells. The quantum yield of Chroococcus photosynthesis was measured at a succession of wave lengths throughout the visible spectrum, and the dependence of yield on wave length was compared with the proportions of light absorbed by the pigment components. This comparison showed beyond reasonable doubt that the light absorbed by phycocyanin is utilized in photosynthesis with an efficiency approximately equal to that of the light absorbed by chlorophyll. The light absorbed by the carotenoid pigments of Chroococcus seems for the most part to be unavailable for photosynthesis. The results leave open the possibility that light absorbed by the carotenoids is active in photosynthesis, but with an efficiency considerably lower than that of chlorophyll and phycocyanin. It is also possible that the light absorbed by one or a few of the several carotenoid components is utilized with a high efficiency, while the light absorbed by most of the components is lost for photosynthesis. PMID- 19873298 TI - THE PHYSIOLOGICAL EFFECTS OF l-TYROSINE AND l-PHENYL-ALANINE ON THE RATE AND QUALITY OF PULSATION IN THE SEVENTY-TWO HOUR EXTIRPATED EMBRYONIC CHICK HEART. AB - 1. 72 hour isolated chick hearts show an increase in pulsation rate when placed in M/1000, M/10,000, and M/50,000 l-tyrosine solutions. The optimal effect is seen in M/10,000 and M/50,000 l-tyrosine. 2. All hearts show disturbance of rhythm either in the form of irregular rhythm or heart block. 3. 62 hour isolated chick hearts are not susceptible to l-tyrosine while 96 hour hearts are markedly sensitive. 4. 72 hour isolated chick hearts placed in 1 part in 10,000 and 1 part in 50,000 l-epinephrine show approximately the same effects as were seen with l tyrosine. 5. 72 hour isolated chick hearts placed in M/1000 and M/10,000 l phenylalanine show an initial depression followed by an l-tyrosine effect. PMID- 19873299 TI - THE FLOCCULATION MAXIMUM (pH) OF FIBRINOGEN AND SOME OTHER BLOOD-CLOTTING REAGENTS. (RELATIVE TURBIDIMETRY WITH THE EVELYN PHOTOELECTRIC COLORIMETER). AB - By means of a novel adaptation of the Evelyn photoelectric colorimeter to the measurement of relative turbidities, the question of the flocculation maximum (F.M.) in acetate buffer solutions of varying pH and salt content has been studied on (a) an exceptionally stable prothrombin-free fibrinogen and its solutions after incipient thermal denaturation and incomplete tryptic proteolysis, (b) plasma, similarly treated, (c) prothrombin, thrombin, and (brain) thromboplastin solutions. All the fibrinogens show a remarkable uniformity of the precipitation pattern, viz. F.M. =4.7 (+/-0.2) pH in salt containing buffer solutions and pH = 5.3 (+/-0.2) in salt-poor buffer (N/100 acetate). The latter approximates the isoelectric point (5.4) obtained by cataphoresis (14). There is no evidence that denaturation or digestion can produce any "second maximum." The data support the view that fibrin formation (under the specific influence of thrombin) is intrinsically unrelated to denaturation and digestion phenomena, although all three can proceed simultaneously in crude materials. A criticism is offered, therefore, of Wohlisch's blood clotting theory. Further applications of the photoelectric colorimeter to coagulation problems are suggested, including kinetic study of fibrin formation and the assay of fibrinogen, with a possible sensitivity of 7.5 mg. protein in 100 cc. solution. PMID- 19873300 TI - THE PRESENCE OF AN ENDOGENOUS RESPIRATION IN THE AUTOTROPHIC BACTERIA. AB - It is shown that there exists in the autotrophic bacterium Thiobacillus thiooxidans a measurable oxygen uptake in the absence of the specific nutrient (sulfur). This respiration is shown to be due to the utilization of organic materials which must have been previously synthesized by the chemosynthetic process, providing evidence that autotrophic bacteria contain a dissimilatory process which involves the breakdown of organic materials and furnishes energy for the maintenance of the cell during periods in which the specific nutrient is absent. This is entirely in accord with the work of Bomeke (1939), who provided similar types of proof for Nitrosomonas and Nitrobacter. One may conclude, therefore, that autotrophic bacteria possess an endogenous respiration which involves the utilization of previously synthesized organic materials. PMID- 19873301 TI - THE EFFECTS OF HYDROGEN ION CONCENTRATION UPON THE METAMORPHIC PATTERN OF THYROXIN- AND IODINE-TREATED TADPOLES. AB - 1. It has been shown quantitatively that the degree of response of the hind limbs of tadpoles to the action of thyroxin is dependent upon the lengths of the limbs at the beginning of treatment. 2. Both the potency of the inducing substance and the rate of penetration of the substance into the animal might be involved in the effects of hydrogen ion concentration on induced development. 3. Changes in hydrogen ion concentration affect the inducing power of thyroxin and iodine differently. With thyroxin, it is the rate of penetration of the molecule which determines the amount of growth, but with iodine it is the chemical form in which the substance has entered the animal which is of prime importance. 4. The hydrogen ion concentration of thyroxin solutions does not affect their potency when they are injected into tadpoles. 5. Change in hydrogen ion concentration of the environment does not affect the potency of thyroxin injected into tadpoles. 6. When thyroxin is administered in the environmental solution its effects, as measured by increase in hind limb length are greater at higher than at lower hydrogen ion concentrations in the range tested. 7. Since the potency of thyroxin is unaffected by change in hydrogen ion concentration when the thyroxin solution is injected, the above fact (point 6) seems explicable only on the basis of differences in the rate of penetration of thyroxin into the animals at the different hydrogen ion concentrations. 8. These differences in penetration of the thyroxin at different hydrogen ion concentrations may be the result of a differential effect of hydrogen ion concentration upon the rate of metabolism of the animal. The metabolic rate is significantly greater when the tadpoles are kept in solutions of higher hydrogen ion concentration than when they are kept in solutions of low hydrogen ion concentration. It is postulated that the rate of metabolism, since it controls the rate of intake of the environmental fluid and therefore of dissolved thyroxin, also controls the amount of thyroxin-induced development. 9. Change in hydrogen ion concentration of iodine solutions affects their potency when injected into tadpoles. A peak of effectiveness is reached at about the neutral point, with a lowered efficiency as the hydrogen ion concentration is either increased or decreased from this point. 10. Change in hydrogen ion concentration of the environment affects the potency of iodine injected into tadpoles. The effect is similar to that noted in point 9. 11. The hydrogen ion concentration of the environment seems to affect the chemical nature of the iodine in solution in the environment. If this is so, it is possible that the differences in the metamorphic effects of iodine at different hydrogen ion concentrations are dependent upon the chemical form of iodine present. 12. The effect of hydrogen ion concentration on normal development is similar to that on thyroxin-induced development; an effect on the rate of metabolism of the animal causes increased growth in more acid solutions. PMID- 19873302 TI - CERTAIN ENZYMATIC ACTIVITIES OF NORMAL AND MOSAIC INFECTED TOBACCO PLANTS. AB - The lower leaves of tobacco plants were inoculated with leaf mosaic virus and the activities of oxygenase, peroxidase, catalase, and invertase were followed in leaves of comparable age at intervals of 2 or 3 days over a period of 21 days. The inoculated leaves exhibited a great decrease relative to normal tissue in the activity of oxygenase and peroxidase on the 6th day. Younger leaves showed this minimum at a progressively later date. A great decrease in the activities of these enzymes was attained by the 14th to the 18th day. This maximum was followed by a decrease. Catalase exhibited an increased activity which reached a maximum at about the 8th day. A second maximum was observed on the 16th to the 18th day. Invertase reached a minimum, relative to normal plants, on about the 8th day. A second minimum was approached on the 16th to the 18th day. These data show that profound disturbances in the physiology of infected plants occur many days before the leaf juice attains an infectious concentration of virus. The observed activities could not be due therefore to metabolic activities of the virus particles themselves. Since infectivity is attained only after a period of profound physiological disturbance, it seems possible that the virus protein develops as a product of abnormal metabolism. PMID- 19873303 TI - A SIMPLIFIED DIFFERENTIAL MICRORESPIROMETER. PMID- 19873304 TI - THE ACTIVATION OF PAPAIN TRYPSINASE AS A FUNCTION OF THE NATURE OF THE ACTIVATOR. PMID- 19873305 TI - PURIFICATION OF THROMBIN. AB - 1. Under certain conditions crude prothrombin changes to thrombin without the addition of extraneous activators and in the absence of ionic calcium. 2. Thrombin is soluble in 0.45 saturated ammonium sulfate, whereas crude prothrombin is not. 3. Partially purified thrombin is comparatively stable in concentrated ammonium sulfate solutions at pH 5.2. 4. A method based on the above facts yields a thrombin preparation the specific activity of which is 100 to 175 times the potential specific activity of whole plasma. PMID- 19873306 TI - THE METABOLISM OF TISSUE CULTURES : I. PRELIMINARY STUDIES ON CHICK EMBRYO. AB - 1. The metabolism of chick embryo tissues has been followed by analysis of the culture media after various periods of incubation in roller bottles. 2. The initial rate of glucose utilization is increased by increasing glucose in the medium from 100 to 500 mg. per cent. Total glucose used can be increased in the same way or by daily addition of small amounts. Glucose is used in greatest amount when the medium containing 100 mg. per cent is replaced daily. 3. Although glucose consumption appears necessary for survival of cultures it may be used at a rate far in excess of that required for life and maximal growth. Complete blocking of mitosis by colchicine does not alter the rate of glucose utilization. 4. Proteolytic activity of the cultures is shown by an increase in the amino nitrogen of the peptone medium after incubation with tissue. 5. Utilization of nitrogen from an amino acid medium is shown by a decrease in the amino nitrogen of this medium. Cells obtaining their nitrogen from amino acids proliferate as rapidly as those grown in a medium identical except for the substitution of peptone, but the cell type is markedly different, in that embryo muscle forms cells resembling regenerating adult muscle. 6. Lactic acid was formed in both the presence and absence of glucose. Its formation increased with increased glucose utilization. There is some evidence that lactate may be utilized, and that it favors growth in the absence of glucose. 7. Added pyruvate was rapidly metabolized by the tissues. It, too, favors growth slightly in the absence of glucose. PMID- 19873307 TI - THE INFLUENCE OF DETERGENTS ON SOME PHYSIOLOGICAL PHENOMENA, ESPECIALLY ON THE PROPERTIES OF THE STELLATE CELLS OF THE FROG LIVER. AB - 1. After a consideration of the physicochemical properties of detergents, it was deemed worth while to study some of their physiological effects. As nonpolar polar electrolytes, the detergents are surface-active and as such cytolytics; but probably due to their dispersing and wetting properties, they are cytolytic in a fashion different from that of other cytolytics. The detergents tested were alkyl sulfonates, alkyl sulfosuccinates, and bile salts. 2. The cytolytic power has been tested in two ways, (1) with red cells by following the escape of hemoglobin, (2) with muscles by measuring the development of an injury potential. In both series of experiments the threshold concentrations of action have been determined. The effect on the potentials has proved to be, in general, reversible. 3. The hemolytic and the myolytic power run fairly parallel to the surface activity. 4. Dehydrocholate has been found to be lacking in nonpolar polar properties. 5. The stellate cells (Kupffer cells) of the Ringer-perfused frog liver are unable to take up colloidal dyestuffs (trypan blue and soluble blue R), except after addition of a small amount of serum to the perfusing Ringer solution. Only under the latter conditions, the uptake of dye is increased by adding a detergent. This seems to be due to the combined action of the proteins and the detergents. 6. The effect of relatively high concentrations of detergent is disintegration of the stellate cells; viz., cytolysis. There are reasons to assume that small concentrations, which produce a threshold increase of the dyestuff uptake, raise the functional activity. PMID- 19873308 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : VI. OBSERVATIONS ON THE GLYCOGEN CONTENT, CARBOHYDRATE CONSUMPTION, LACTIC ACID PRODUCTION, AND AMMONIA PRODUCTION OF EGGS OF ARBACIA PUNCTULATA. AB - 1. Under the present conditions of experiment, Arbacia eggs were found to contain an average of 110 mg. of acid-hydrolyzable carbohydrate (calculated as glucose) per gm. of egg protein. This carbohydrate was almost all in the egg proper, little or none being found in the jelly. To permit conversion of the data to other bases of reference the relation of nitrogen content to wet and dry weight and to egg number were determined. The eggs were found to contain 23.9 per cent solids, 0.10 mg. nitrogen per mg. dry weight, and 5.93 mg. nitrogen per 10(6) cells. From these results, about 7 per cent of the egg dry weight is acid hydrolyzable carbohydrate and about 65 per cent is protein. 2. Approximately one half of the total acid-hydrolyzable carbohydrate was isolated in the form of an alkali-stable, alcohol-precipitable carbohydrate. This substance gave a typical glycogen color test with iodine, yielded glucose on acid hydrolysis, and had, within the limits of experimental error, the same optical rotation as glycogen from other animal sources. Since known amounts of glycogen were completely recovered when carried through the isolation process, the nature of one-half of the acid-hydrolyzable carbohydrate of Arbacia eggs remains undetermined. 3. In order to gain some estimate of the extent to which Arbacia eggs utilize their total carbohydrate for development, determinations of the oxygen consumption, respiratory quotient, carbohydrate consumption, lactic acid production, and ammonia production were made. While all samples of eggs were found to utilize carbohydrate from the 15th to the 24th hours of development at 20 degrees C., certain samples of eggs consumed little or no carbohydrate from the 1st to the 6th hours, the period during which cell division proceeds most rapidly. In a number of instances where carbohydrate breakdown was lacking, a substantial proportion of the oxygen consumption could be accounted for on the basis of processes involving oxidation of protein or protein breakdown products. PMID- 19873309 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : VII. OBSERVATIONS ON THE AMOUNT AND POSSIBLE FUNCTION OF DIPHOSPHOTHIAMINE (COCARBOXYLASE) IN EGGS OF ARBACIA PUNCTULATA. AB - 1. Methods suitable for the determination of diphosphothiamine (cocarboxylase) in eggs of Arbacia punctulata have been developed. Quantitative extraction of the cocarboxylase was effected by combining the use of thiamine hydrochloride in the extraction fluid with critical adjustment of the pH of extraction to pH 6.3-6.7. 2. The unfertilized eggs were found to contain the equivalent of 2 to 3 micrograms of natural yeast cocarboxylase per gm. of wet eggs; the cocarboxylase content of the 30 minute and 10 hour fertilized eggs was somewhat less (Table III). 3. In preliminary experiments, Arbacia egg cytolysates were found to cause pyruvic acid to disappear. The rate of such disappearance was apparently greater under aerobic than under anaerobic conditions; it was also greater for cytolysates from fertilized eggs than for cytolysates from unfertilized eggs (Table IV). PMID- 19873310 TI - STUDIES ON CELL METABOLISM AND CELL DIVISION : VIII. THE DIPHOSPHOPYRIDINE NUCLEOTIDE (COZYMASE) CONTENT OF EGGS OF ARBACIA PUNCTULATA. AB - 1. The diphosphopyridine nucleotide content of Arbacia eggs has been measured manometrically and found to be approximately 250-500 micrograms per gm. wet weight of eggs, the value varying with individual egg samples and with the state of development of the eggs. Of the total diphosphopyridine nucleotide present, approximately 25-40 per cent is in an alkali-stable, presumably the dihydro, form. 2. Tests for triosephosphate and glutamic acid dehydrogenases carried out on Arbacia egg cytolysates were negative. PMID- 19873311 TI - THE CHLOROPHYLL-PROTEIN COMPLEX : I. ELECTROPHORETIC PROPERTIES AND ISOELECTRIC POINT. AB - 1. Reported effects of different conditions on the stability of the purified chlorophyll-protein complex have been confirmed. 2. The electrophoretic behavior of the chlorophyll-protein complex prepared from two unrelated species of plants (Aspidistra elatior and Phaseolus vulgaris) has been investigated and shown to be dissimilar. In M/50 acetate buffer at 25 degrees C, the isoelectric point of the complex from Phaseolus is at pH 4.70, whereas that from Aspidistra is at pH 3.9 (extrapolated). These values fall within the usual range of protein isoelectric points. 3. Treatment with weak acids causes an irreversible denaturation of the protein complex from both species, with a resultant shift in the mobility-pH curves to more basic values. 4. Differences in electrophoretic behavior between the chlorophyll-protein complex and the cytoplasmic proteins of Phaseolus have been demonstrated. The isoelectric point of the latter is at pH 4.22. PMID- 19873312 TI - ELECTRIC IMPEDANCE OF THE FROG EGG. AB - Electrical impedance measurements were made upon unfertilized and fertilized eggs of the leopard frog, Rana pipiens, over a frequency range of 0.05 to 10 kc. Average values of 170 ohm cm.(2) were obtained for the plasma membrane resistance of the egg, 2.0 microf/cm.(2) for the plasma membrane capacity, 86 degrees for the phase angle of the membrane, and 570 ohm cm. for the specific resistance of the interior. These values did not change upon fertilization. No spontaneous rhythmical impedance changes such as have been found by Hubbard and Rothschild in the trout egg were found in frog eggs. PMID- 19873313 TI - PANTOTHENIC ACID AND THE UTILIZATION OF GLUCOSE BY LIVING AND CELL-FREE SYSTEMS. AB - 1. Added pantothenic acid was found to have no appreciable effect on the fermentation of glucose when used in conjunction with preparations of dialyzed yeast maceration juice or acetone-precipitated yeast maceration juice. 2. Addition of pantothenic acid failed to affect the rate of phosphorylation of glucose or the rate of decarboxylation of pyruvic acid by yeast maceration juice. 3. Pantothenic acid showed no effect on the rate of glycolysis by homogenized deficient chick tissues. 4. The accelerating effect of pantothenic acid on fermentation by deficient yeast cells was found to be accompanied by a "binding" of pantothenic acid by the yeast cells. PMID- 19873314 TI - THE VALENCE OF CORPUSCULAR PROTEINS. AB - BY THE USE OF TWO EXTREME MODELS: a hydrated sphere and an unhydrated rod the valence (net charge) of corpuscular proteins can be successfully calculated from electric mobility data by the Debye-Huckel theory (modified to include the effect of the ions in the ion atmosphere) in conjunction with the electrophoretic theory of Henry. As pointed out by Abramson, this permits a comparison with values for the valence from titration data. Electrometric titration measurements of serum albumin B (Kekwick) have been determined at several ionic strengths. These results, together with the available data in the literature for serum albumin B, egg albumin, and beta-lactoglobulin have been used to compare values for the valence calculated from measurements of titration, electrophoresis, and membrane potentials. The results indicate that the usual interpretation of titration curves is open to serious question. By extrapolation of the titration data to zero ionic strength and protein concentration, there results an "intrinsic" net charge curve describing the binding of H(+) (OH(-)) ion alone. This curve agrees closely, in each case, with values of the valence calculated from mobility data (which in turn are in close accord with those estimated from membrane potential measurements). The experimental titration curves in the presence of appreciable quantities of ions and protein deviate widely from the ideal curve. It is suggested that, under these conditions, binding of undissociated acid (base) leads to erroneous values for the net charge. This binding would not affect the electrophoretic mobility. Values of the net charge obtained by the two extreme models from electrophoretic data are in agreement within 15 to 20 per cent. The agreement between the cylindrical model and the titration data is somewhat better in each case than with the sphere; i.e., this comparison enables a choice to be made between asymmetry and hydration in the interpretation of results from sedimentation and diffusion measurements on proteins. It is concluded that the proteins discussed here are somewhat asymmetric and also hydrated. PMID- 19873315 TI - THE ACTION OF SULFONAMIDES ON THE RESPIRATION OF BACTERIA AND YEAST : INHIBITION OF BACTERIAL AND YEAST CARBOXYLASES BY SULFONAMIDE DRUGS STRUCTURALLY RELATED TO COCARBOXYLASE. AB - The inhibiting effects of sulfonamide drugs and their derivatives on the anaerobic decarboxylation of pyruvic acid by Staphylococcus aureus, Escherichia coli, baker's and brewer's yeast, and a carboxylase preparation from brewer's yeast have been investigated. These drugs are: sulfanilamide, sulfapyridine, sulfadiazine, sulfamethyldiazine, sulfathiazole, sulfamethylthiazole, sulfanilamido-5-ethyl-4-thiazolone, 2-aminopyrimidine, 2-aminothiazole, and 2 aminopyridine. The sulfathiazole ring appears to exercise decidedly greater specific inhibiting effect on the carboxylases of Staph. aureus and E. coli. The inhibiting effect on yeast carboxylase is non-differentiable among all the substances tried, except sulfamethyldiazine which is completely ineffective on the carboxylases of the organisms studied. The specific inhibitory effect of sulfathiazole on the carboxylases of Staph. aureus and E. coli in comparison to sulfanilamide, sulfapyridine, and sulfadiazine is in harmony with in vivo and in vitro experimental results of other investigators. The results of the present investigation appear to support the hypothesis (1) that sulfonamides exert their bacteriostatic action through chemical affinity for the carrier proteins of certain respiratory enzymes of the bacterial cell, and that this affinity may in part be related to structural similarity between components of the drugs and the corresponding respiratory coenzymes. PMID- 19873316 TI - ENERGY, QUANTA, AND VISION. AB - 1. Direct measurements of the minimum energy required for threshold vision under optimal physiological conditions yield values between 2.1 and 5.7 x 10(-10) ergs at the cornea, which correspond to between 54 and 148 quanta of blue-green light. 2. These values are at the cornea. To yield physiologically significant data they must be corrected for corneal reflection, which is 4 per cent; for ocular media absorption, which is almost precisely 50 per cent; and for retinal transmission, which is at least 80 per cent. Retinal transmission is derived from previous direct measurements and from new comparisons between the percentage absorption spectrum of visual purple with the dim-vision luminosity function. With these three corrections, the range of 54 to 148 quanta at the cornea becomes as an upper limit 5 to 14 quanta actually absorbed by the retinal rods. 3. This small number of quanta, in comparison with the large number of rods (500) involved, precludes any significant two quantum absorptions per rod, and means that in order to produce a visual effect, one quantum must be absorbed by each of 5 to 14 rods in the retina. 4. Because this number of individual events is so small, it may be derived from an independent statistical study of the relation between the intensity of a light flash and the frequency with which it is seen. Such experiments give values of 5 to 8 for the number of critical events involved at the threshold of vision. Biological variation does not alter these numbers essentially, and the agreement between the values measured directly and those derived from statistical considerations is therefore significant. 5. The results clarify the nature of the fluctuations shown by an organism in response to a stimulus. The general assumption has been that the stimulus is constant and the organism variable. The present considerations show, however, that at the threshold it is the stimulus which is variable, and that the properties of its variation determine the fluctuations found between response and stimulus. PMID- 19873317 TI - THE EFFECT OF AUXINS ON PROTOPLASMIC STREAMING. III. AB - 1. A new method is described which gives a continuous record of the absolute rate of protoplasmic streaming in epidermal cells of the Avena coleoptile. 2. With this method a study was made of the influence of malate and iodoacetate on streaming velocity, in order to make correlations with the previously established effects of these substances on growth and respiration. 3. In the presence of optimum concentrations of indole-3-acetic acid in freshly cut sections, malate had no effect on streaming. In the presence of very low concentrations of the auxin, however, malate increased the range of response, so that the threshold of auxin sensitivity was lowered some ten times by the malate. Malate alone had no effect on streaming. 4. In coleoptile sections, soaked overnight in sugar solution or in water, the acceleration of streaming normally caused by auxin almost disappears, but the presence of malate causes large accelerations of streaming by the auxin. 5. Similarly, in sections from old coleoptiles, which no longer show acceleration of streaming by auxin, the acceleration is restored when malate is added together with the auxin. 6. Malate does not enter the cell as rapidly as does auxin, but easily detectable amounts penetrate within 30 minutes. 7. Iodoacetate in the concentration which inhibits growth (5 x 10(-5)M) completely inhibits the acceleration of streaming by auxin. In still lower concentrations iodoacetate slightly accelerates streaming. Higher concentrations, up to 2 x 10(-4)M, did not reduce the rate of streaming below that of controls without auxin. The effect of iodoacetate is therefore to inhibit the acceleration caused by auxin and not to affect the basal streaming rate. 8. It is concluded that, just as for growth and respiration, malate is necessary for the response to auxin shown by acceleration of streaming. This further strengthens the triple parallel between the effects of auxin on streaming, growth, and respiration, all of which are apparently mediated by the 4-carbon acid system. PMID- 19873318 TI - HYDROSTATIC PRESSURE AND TEMPERATURE IN RELATION TO STIMULATION AND CYCLOSIS IN NITELLA FLEXILIS. AB - Nitella flexilis cells are not stimulated to "shock stoppage" of cyclosis by suddenly evacuating the air over the water or on sudden readmission of air, or on suddenly striking a piston in the water-filled chamber in which they are kept with a ball whose energy is 7.6 joules, provided the Nitella cell is not moved by currents against the side of the chamber. Sudden increases in hydrostatic pressure from zero to 1000 lbs. or 0 to 5000 lbs. per square inch or 5000 to 9000 lbs. per square inch usually do not stimulate to "shock stoppage" of cyclosis, but some cells are stimulated. Sudden decreases of pressure are more likely to stimulate, again with variation depending on the cell. In the absence of stimulation, the cyclosis velocity at 23 degrees C. slows as the pressure is increased in steps of 1000 lbs. per square inch. In some cells a regular slowing is observed, in others there is little slowing until 4000 to 6000 lbs. per square inch, when a rapid slowing appears, with only 50 per cent to 30 per cent of the original velocity at 9000 lbs. per square inch. The cyclosis does not completely stop at 10000 lbs. per square inch. The pressure effect is reversible unless the cells have been kept too long at the high pressure. At low temperatures (10 degrees C.) and at temperatures near and above (32 degrees -38 degrees C.) the optimum temperature for maximum cyclosis (35-36 degrees C.) pressures of 3000 to 6000 lbs. per square inch cause only further slowing of cyclosis, with no reversal of the temperature effect, such as has been observed in pressure temperature studies on the luminescence of luminous bacteria. Sudden increase in temperature may cause shock stoppage of cyclosis as well as sudden decrease in temperature. PMID- 19873319 TI - ACCUMULATION OF SALT AND PERMEABILITY IN PLANT CELLS. AB - 1. Comparisons are made of concentrations of K and Br in exudates of barley roots and in expressed sap from roots, under conditions favorable for aerobic metabolism. Both methods lead to the same general viewpoint concerning metabolically governed transport of solutes by living plant cells. 2. Cyanide in low concentration prevented salt accumulation by barley roots. Methylene blue, without decrease of CO(2) production by roots, destroyed power of salt accumulation. 3. K and Br ions entered roots to only a slight extent under an anaerobic condition, even with an inward gradient of ionic concentration. 4. Lactate or alcohol, under aerobic conditions, did not prevent rapid accumulation of salt by root cells. 5. Experiments on fluids obtained by suction from tomato roots gave evidence of loss of salt-accumulating power under the influence of N(2) gas or CO(2) gas, together with probable effects on cell permeability. 6. Several experiments on Nitella cells in which radioactive isotopes were used are reported. Bromide gradually moved into vacuolar sap until the concentration appeared to exceed that of the protoplasm, on the basis of the results of the several types of experiments. Accumulation of salt in the vacuole did not occur anaerobically. 7. Some views of interrelations of permeability, salt accumulation, and metabolism are suggested for further discussion. PMID- 19873320 TI - THE PREPARATION AND USE OF TOBACCO MOSAIC VIRUS CONTAINING RADIOACTIVE PHOSPHORUS. AB - Normal and tobacco mosaic-diseased Turkish tobacco plants were grown in sand for a period of several weeks, during which they were fed daily a complete nutrient solution to which had been added disodium phosphate containing radioactive phosphorus. Determinations were made of the distribution of radioactive phosphorus in different fractions such as the wash from the sand and roots, the press cake obtained on pressing the juice from the plants, the protein and protein-free portions of the supernatant liquids obtained on ultracentrifugation of the juices, and the purified tobacco mosaic virus isolated from the diseased plants. Chemical analyses as well as radiographs of the normal and diseased leaves indicated that they contained the same amount of phosphorus. Approximately 30 per cent of the radioactive phosphorus absorbed by the diseased plants was found to be combined with the purified tobacco mosaic virus that was isolated from these plants. Following the inoculation of purified tobacco mosaic virus possessing high radioactivity to normal Turkish tobacco plants, most of the radioactivity was found to be associated with non-virus components of which about 40 per cent was in the inoculated and 60 per cent in the uninoculated portions of the plants. Although a small amount of radioactive virus was isolated from the uninoculated portions of the plants, it was impossible, because of a number of complicating factors which have been discussed, to draw from the results any reliable conclusions regarding the mode of reproduction of tobacco mosaic virus. PMID- 19873321 TI - RESPIRATORY EFFECTS UPON THE VISUAL THRESHOLD. AB - Measurements are reported of the effects of respiratory stresses upon the absolute threshold of peripheral (rod) vision. Since subjects were kept wholly dark adapted and the photochemical system of the rods therefore stationary, the changes recorded may be assumed to have originated more centrally. To this degree the measurements provide a quantitative index of central nervous imbalance. Breathing room air or 32 to 36 per cent oxygen at about double the normal rate causes the visual threshold to fall to approximately half the normal value within 5 to 10 minutes. This change is due primarily to alkalosis induced by the hyperventilation, and can be abolished or reversed by adding carbon dioxide to the inspired mixtures. Normal or rapid breathing of 2 per cent carbon dioxide causes no change in threshold; with 5 per cent carbon dioxide the threshold is approximately doubled. Breathing 10 per cent oxygen at the normal rate also approximately doubles the threshold. This effect is compensated in part by rapid breathing. When 10 per cent oxygen is breathed at twice the normal rate the threshold usually falls at first, then slowly rises to supernormal levels. Due primarily to variations in their breathing patterns subjects yield characteristically different responses on sudden exposure to low oxygen tensions with breathing uncontrolled. The threshold may either rise or fall; and on release from anoxia it may rise, or fall to normal or subnormal levels. The threshold adjusts to anoxia rapidly; exposures lasting 5 to 6 hours do not produce greater or more persistent changes than those of much shorter duration. PMID- 19873322 TI - THE RELATIONS OF TEMPERATURE TO THE POTASSIUM EFFECT AND THE BIOELECTRIC POTENTIAL OF VALONIA. AB - The effect of temperature upon the bioelectric potential across the protoplasm of impaled Valonia cells is described. Over the ordinary tolerated range, the P.D. is lowest around 25 degrees C., rising both toward 15 degrees and 35 degrees . The time curves are characteristic also. The magnitude of the temperature effect can be controlled by changing the KCl content of the sea water (normally 0.012 M): the magnitude is greatly reduced at 0.006 M KCl, enhanced at 0.024 M, and greatly exaggerated at 0.1 M KCl. Conversely, temperature controls the magnitude of the potassium effect, which is smallest at 25 degrees , with a cusped time course. It is increased, with a smoothly rising course, at 15 degrees , and considerably enhanced, with only a small cusp, at 35 degrees . A temporary "alteration" of the protoplasmic surface by the potassium is suggested to account for the time courses. This alteration does not occur at 15 degrees ; the protoplasm recovers only slowly and incompletely at 25 degrees , but rapidly at 35 degrees , in such fashion as to make the P.D. more negative than at 15 degrees . This would account for the temperature effects observed in ordinary sea water. PMID- 19873323 TI - CYANIDE-SENSITIVE BACTERIAL RESPIRATORY SYSTEMS DIFFERENT FROM THE USUAL CYTOCHROME-CYTOCHROME OXIDASE SYSTEM. AB - Aerobic respiration of Streptococcus pyogenes and pneumococcus Type 1 are strongly inhibited by KCN, NaN(3), and Na(2)S. The anaerobic glycolysis of glucose by pneumococcus is also inhibited by KCN and NaN(3). Streptococcus pyogenes, E. coli, pneumococcus Type 1, B. subtilis, B. proteus, and Staphylococcus aureus did not catalyze the oxygen uptake by p-phenylenediamine in the presence of added cytochrome c or in its absence. Yeast cells, B. subtilis, and B. pyocyaneus oxidized p-phenylenediamine to a dark purple meriquinoid substance in contrast to the other bacteria mentioned above. Streptococcus pyogenes in contrast to pneumococcus Type 1 catalyzed the oxygen uptake by cysteine. Neither of these bacteria catalyzed the oxygen uptake by tyrosine, adrenaline, pyrocatechin, xanthine, and hypoxanthine. Streptococcus pyogenes, pneumococcus Type 1, and E. coli, boiled and not boiled, gave positive peroxidative tests with benzidine showing the presence of hematin compounds. The results discussed in the light of the interpretations offered by Keilin and Harpley show that Streptococcus pyogenes and pneumococcus Type 1 contain cyanide sensitive respiratory systems which are different from the cytochrome c cytochrome oxidase system. PMID- 19873324 TI - STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA : II. THE NATURE OF THE CHEMOSYNTHETIC REACTION. AB - In a study of chemosynthesis (the fixation of CO(2) by autotrophic bacteria in the dark) in Thiobacillus thiooxidans, the data obtained support the following conclusions: 1. CO(2) can be fixed by "resting cells" of Thiobacillus thiooxidans; the fixation is not "growth bound." 2. The physiological condition of the cell is of considerable importance in determining CO(2) fixation. 3. CO(2) fixation can occur in the absence of oxidizable sulfur in "young" cells. The extent of this fixation appears to be dependent upon the pCO(2). 4. CO(2) fixation can also occur under anaerobic conditions and the presence of sulfur does not influence such fixation. 5. However, in the CO(2) fixation by cells in the absence of sulfur, only a limited amount of CO(2) can be fixed. This amount is approximately 40 microl. CO(2) per 100 micrograms bacterial nitrogen. After a culture has utilized this amount of CO(2) it no longer has the ability to fix CO(2) but releases it during its respiration. 6. Relatively short periods of sulfur oxidation can restore the ability of cells to fix CO(2) under conditions where sulfur oxidation is prevented. 7. It is possible to oxidize sulfur in the absence of CO(2) and to store the energy thus formed within the cell. It is then possible to use this energy at a later time for the fixation of CO(2) in the entire absence of sulfur oxidation. 8. Cultures of Thiobacillus thiooxidans respiring on sulfur utilize CO(2) in a reaction which proceeds to a zero concentration of CO(2) in the atmosphere. 9. CO(2) may act as an oxidizing agent for sulfur. 10. Hydrogen is not utilized by the organism. 11. It is possible to selectively inhibit sulfur oxidation and CO(2) fixation. PMID- 19873325 TI - THE ANTIGENICITY OF d-RIBONUCLEASE; THE INHIBITION OF THE ENZYME BY ITS HOMOLOGOUS IMMUNE SERUM. AB - The enzyme d-ribonuclease is antigenic. Antisera, prepared by three different methods, reacted against antigen dilutions up to one million. Apparently the homologous antiserum, when combined with the d-ribonuclease inhibited the activity of the enzyme from 10 to 30 per cent. PMID- 19873326 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : IV. THE RELATIVE MERITS OF THE HOMOGENEOUS PHASE THEORY AND THE MICELLAR-STRUCTURAL THEORY AS APPLIED TO THE DRIED COLLODION MEMBRANE. AB - 1. Experiments were carried out to decide whether a homogeneous phase (solubility) theory or a micellar-structural theory more adequately describes the behavior of dried collodion membranes with solutions of strong electrolytes. 2. A number of dried collodion membranes were prepared from an electrochemically inactive collodion preparation (state I); the characteristic concentration potentials across them were low, about 30 mv. The membranes were activated by oxidation (state II) to give maximum or nearly maximum concentration potentials (about 50 mv.). The oxidized membranes are dried, dissolved in alcohol-ether, and a new set of dry collodion membranes prepared from this solution (state III). The concentration potentials across these membranes are low. 3. Since the properties of a homogeneous phase should not be influenced by a rearrangement of its constituent particles, the experimental results do not support a homogeneous phase (solubility) theory, but they agree with the predictions of the micellar structural theory. The characteristic behavior of dried collodion membranes in solutions of strong inorganic electrolytes is therefore due to the micellar character of its interstices. PMID- 19873327 TI - THE REGENERATION OF VISUAL PURPLE IN THE LIVING ANIMAL. AB - 1. The accumulation of visual purple in the retina after bleaching by light has been studied in the intact eye of the frog. The data show that duration and intensity of light adaptation, which influence the course of human dark adaptation as measured in terms of visual threshold, have a similar influence on the course of visual purple regeneration. 2. At 25 degrees C. frogs which have been light adapted to 1700 millilamberts and then placed in the dark, show an increase in visual purple concentration which begins immediately and continues for 70 minutes until a maximum concentration is attained. The increase, although beginning at once, is slow at first, then proceeds rapidly, and finally slows up towards the end. Frogs which have been adapted to 9500 millilamberts show essentially the same phenomenon except that the initial slow period is strongly delayed so that almost no visual purple is formed in the first 10 minutes. 3. At 15 degrees C. the initial delay in visual purple regeneration occurs following light adaptation to both 1700 and 9500 millilamberts. The delay is about 10 minutes and is slightly longer following the higher light adaptation. 4. The entire course of visual purple accumulation in the dark takes longer at the lower temperature than at the higher. The temperature coefficient for 10 degrees C. is about 1.8. 5. In contrast to the behavior of the isolated retina which has small amounts of vitamin A and large amounts of retinene immediately after exposure to light, the intact eye has large amounts of vitamin A and little retinene after exposure to light for 10 minutes. In the intact eye during dark adaptation, the amount of vitamin A decreases markedly while retinene decreases only slightly in amount. If retinene is formed in the intact eye, the change from retinene to vitamin A must therefore occur rapidly in contrast to the slow change in the isolated retina. 6. The course of visual purple regeneration may be described by the equation for a first order autocatalyzed reaction. This supposes that the regeneration of visual purple is catalyzed by visual purple itself and accounts for the sigmoid shape of the data. PMID- 19873328 TI - HUMORAL RHEOLOGY : I. VISCOSITY STUDIES AND ANOMALOUS FLOW PROPERTIES OF HUMAN BLOOD SYSTEMS WITH HEPARIN AND OTHER ANTICOAGULANTS. AB - 1. A modified falling ball viscometer (rolling ball viscometer) for blood and other humors is presented. It is capable of easily measuring flow properties at several stresses, as is required to define satisfactorily the properties of anomalous flow systems. At high shearing stresses, apparent specific viscosity values of 2.5 + are observed, corresponding to 2.2 +/-0.2 reported as possible with the biological viscometer of Whittaker and Winton. 2. Previous references to the anomalous flow properties of blood were verified. It was demonstrated that these systems conform to the Bingham concept of anomalous flow. To define completely the flow properties of such systems it is necessary to make determinations at at least two shearing stresses, preferably more. Data are reported for the pseudoviscosity and yield value, the latter being possibly the most specific property of the three bloods studied. 3. Heparin in increasing amounts tended to decrease the apparent viscosity, pseudoviscosity, and yield value of blood. Similar increases of heparin also reduced the viscosites of the serum and plasma. 4. The ratio of the apparent viscosity of blood and its plasma was found to be reasonably constant as reported by Trevan. However, as the apparent viscosity is a function of the shearing stress, it is believed that the relationship for the calculations of corpuscular concentrations, such as the Whittaker and Winton modification of the Hatschek formula, is specific for the instrument and conditions of tests by which it was determined. 5. Heparinized blood was found to exhibit thixotropy, dilatancy, and age-hardening phenomena. PMID- 19873329 TI - INCREASED IRRITABILITY IN NITELLA DUE TO GUANIDINE. AB - Guanidine applied to Nitella may lower the threshold of E.M.F. required to produce electrical stimulation and may give rise to trains of action currents. Its effect thus appears to be somewhat similar to that observed in animals. Rapid action currents are produced as well as "square topped" action curves and transitional forms. These effects may be due in part to increased protoplasmic conductivity produced by the penetration of guanidine. PMID- 19873330 TI - ALLOCATION OF ELECTRICAL RESPONSES FROM THE COMPOUND EYE OF GRASSHOPPERS. AB - 1. The effect of extirpation of the optic ganglion on the ERG and on electrical oscillations recorded from the compound eye was determined. 2. Extirpation of the optic ganglion prevents the occurrence of oscillations, and it is concluded that they originate in the ganglion. 3. Extirpation of the optic ganglion changes the wave form of the ERG. The sharpness of the b-wave is decreased, the relative magnitude of the c-wave is increased, and the d-wave is obliterated. These changes can be explained by assuming that the ERG is the algebraic sum of two potential changes, one in the compound eye, and another, of opposite sign in the ganglion. This assumption is supported by data from a number of experiments in which the electrode positions were varied. 4. The explanation of the present data (which indicates two sites of origin of the ERG) is similar to the three component theory which accounts for the complex wave form of the vertebrate ERG. PMID- 19873331 TI - STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA : I. THE RESPIRATION OF THIOBACILLUS THIOOXIDANS ON SULFUR. AB - THE DATA OF THIS PAPER INDICATE THAT: 1. The "energy of activation" (micro) of sulfur oxidation by the autotrophic bacterium, Thiobacillus thiooxidans, is similar to that of other respirations. 2. The pH of the menstruum does not influence the respiration on sulfur between the limits of pH 2 to 4.8 once contact between the bacterial cell and the sulfur particle has been established but it does influence the rate at which such contact occurs. 3. The pO(2) has little effect upon the respiration of this organism. 4. Most organic materials have no detectable effect upon the respiration of Thiobacillus thiooxidans, but the organic acids of terminal respiration seem to stimulate the respiration in the absence of oxidizable sulfur and certain of them inhibit sulfur oxidation. 5. In so far as inhibitor studies on intact cells are trustworthy, sulfur oxidation goes through iron-containing systems similar to cytochrome. It is possible that the oxygen contained in the sulfuric acid formed during sulfur oxidation is derived from the oxygen of the water. PMID- 19873332 TI - FURTHER CHEMICAL STUDIES ON BLOOD-AQUEOUS HUMOR DYNAMICS. AB - The proportion of SCN, Br, PO(4), urea, levulose, and Fe which remains freely diffusible when added to plasma has been determined by ultrafiltration and "differential" dialysis through a cellophane membrane. After injecting each of these substances as well as Mg and Li into rabbits a continuous record of their concentration in the plasma was obtained for each animal and the concentration in the aqueous humor was also determined and related to the maximum diffusible concentration in the plasma. PMID- 19873333 TI - THE MECHANISM OF AQUEOUS HUMOR FORMATION INFERRED FROM CHEMICAL STUDIES ON BLOOD AQUEOUS HUMOR DYNAMICS. AB - The importance of considering the effect of a possible flow out of the anterior chamber before inferring any mechanism of aqueous humor formation from the relative concentration of a substance in the aqueous humor and plasma under equilibrium conditions has been stressed. Several processes to account for the chemical equilibria between aqueous humor and blood based on the ultrafiltration and secretion hypotheses with a possible simultaneous loss of aqueous humor by flow have been outlined. On the basis of these processes, equations were formulated which would relate the rates of transfer into and out of the anterior chamber to the ratio of concentration of a substance in the aqueous to that in the blood at various intervals after its introduction into the blood. The explanation of equilibrium ratios above and below one for aqueous constituents is made apparent from the mathematical formulations. For each substance tested a determination was made of the best fit when the concentration in the aqueous humor is plotted against time. This fit was obtained by plotting the rate of transfer in against the rate of transfer out of the anterior chamber for all of the experimentally found concentration ratios on the basis of both the ultrafiltration and secretory hypotheses. Two sets of values were obtained from these calculations, one set for each hypothesis. The substantial agreement of all the experimental data with an assumed rate of leakage out of the anterior chamber of approximately 4 c. mm. per minute was shown to be compatible only with the idea that all the monovalent electrolytes tested entered the anterior chamber as a result of secretory process. It could not be decided from these chemical studies whether the non-electrolytes and the one multivalent electrolyte tested enter the anterior chamber by ultrafiltration or secretion. Experimental findings from other sources were cited which would suggest that non-electrolytes enter the anterior chamber as a result of ultrafiltration. The implications of the mechanism outlined in the paper with respect to intraocular pressure have been discussed. Supplementary evidence from the literature has been given in support of the conclusions presented here. PMID- 19873334 TI - THE pH STABILITY OF PROTYROSINASE AND TYROSINASE. AB - 1. pH stability diagrams for protyrosinase and for tyrosinase were constructed. 2. Above pH 7.30 protyrosinase is unstable. Between pH 7.30 and pH 9.30 there is a partial destruction. Beyond pH 9.30 it changes irreversibly into tyrosinase which in turn is destroyed beyond pH 10.12. 3. Through the lower ranges of pH protyrosinase is less stable than tyrosinase The former is destroyed below pH 4.80, while the latter is unaffected until the pH drops below 4.10. 4. The tyrosinase produced at high pH values resembles that produced by other methods. PMID- 19873335 TI - STUDIES ON THE METABOLISM OF THE AUTOTROPHIC BACTERIA : III. THE NATURE OF THE ENERGY STORAGE MATERIAL ACTIVE IN THE CHEMOSYNTHETIC PROCESS. AB - In the autotrophic bacterium, Thiobacillus thiooxidans, the oxidation of sulfur is coupled to transfers of phosphate from the medium to the cells. CO(2) fixation is coupled to transfers of inorganic phosphate from the cells to the medium and is dependent, in the absence of concomitant sulfur oxidation, upon the amount of phosphate previously taken up during sulfur oxidation. The energy reservoir, which is formed by sulfur oxidation in the absence of CO(2) and which can be released for the fixation of CO(2) under conditions which do not permit sulfur oxidation, is a phosphorylated compound and the data suggest that the energy is stored in the cell as phosphate bond energy. It is possible to oxidize sulfur at a constant rate for hours in the absence of CO(2). The phosphate energy formed during this process is probably released by cell phosphotases. It is possible to inhibit these phosphotases by means of inorganic phosphate and thus to inhibit sulfur oxidation in the absence of CO(2). In the presence of CO(2), where alternative uses for the phosphate energy are available, the inhibition is relieved. Sulfur oxidation (energy input) is coupled, not to CO(2) fixation, but to phosphate esterification. CO(2) fixation (energy utilization) is coupled with phosphate release. PMID- 19873336 TI - THE USE OF A MEASURABLE CAUSE OF DEATH (HEMORRHAGE) FOR THE EVALUATION OF AGING. AB - 1. There has been need for a reliable experimental standard for the process of aging. Chronological age is a poor standard owing to irrelevant changes and individual variability. Longevity does not indicate the rate of aging because it depends not only upon aging but also upon intrinsic death rate, individual variability, and the selective effect of experimental treatment upon resistance to specific diseases. 2. The use of a known measurable cause of death (hemorrhage) on healthy animals of various ages reproduces the known mortality curve for rats, and differentiates this measure of the aging process from individual variation. 3. The possibilities for the use of this method in determining the nature of the aging process are pointed out. PMID- 19873337 TI - A NEW METHOD FOR THE GENERATION AND USE OF FOCUSED ULTRASOUND IN EXPERIMENTAL BIOLOGY. AB - 1. An efficient generator of focused ultrasound has been designed, built, and successfully operated. 2. The generator has been used to produce focal heating in the centers of paraffin blocks, and in a similar manner, focal areas of destruction were obtained deep in fresh liver tissue with minimal effects at the surface and no effects on the intervening tissue. 3. In animals, focused ultrasound of high intensity produced local cerebral changes as inferred from behavior disabilities and as demonstrated at autopsy. This local brain effect was achieved through intervening scalp, skull, and meninges. The resulting behavior disabilities disappeared in from 2 to 16 hours. 4. To date, it has not been possible to produce such brain changes without incidental injury to the skin and subcutaneous tissue lying at the base of the cone of radiation. 5. Improvements in generation and application of the focused supersonic beam are suggested whereby it should be possible to increase still further the focal effects in the brain, with a corresponding decrease or elimination of complicating surface injury. PMID- 19873338 TI - THE EFFECT OF SPECIFIC POISONS UPON THE PHOTO-REDUCTION WITH HYDROGEN IN GREEN ALGAE. AB - 1. The effect of poisons upon the photoreduction with hydrogen in Scenedesmus and similar algae has been studied. The poisons used were cyanide, hydroxylamine, dinitrophenol, and carbon monoxide, substances known to inhibit more or less specifically certain enzymatic reactions. 2. It was found that quite generally one has to distinguish between the action of poisons upon the photoreduction in the stationary state, once this type of metabolism has been well established in the cells, and their effects on transition phenomena, on the "adaptation" and its reversal, the "turnback" from photoreduction to photosynthesis. 3. Cyanide inhibits photoreduction more strongly than it inhibits photosynthesis in the same algae. It is concluded that the mechanism of oxygen liberation, which is idle in photoreduction, is not very sensitive to cyanide. 4. Hydroxylamine in low concentrations is a powerful inhibitor of photosynthesis but has practically no influence on the rate of photoreduction. Consequently, it is assumed that it acts in photosynthesis mainly by inhibiting the evolution of oxygen. Greater concentrations of hydroxylamine clearly inhibit photoreduction, but diminish the rate to about one-half only. A greater degree of inhibition is obtained only by prolonged incubation. 5. Dinitrophenol was found to inhibit strongly the reduction of carbon dioxide, under aerobic as well as under anaerobic conditions. A stimulating effect of dinitrophenol can be demonstrated only with respiration or fermentation, not with photosynthesis. 6. Carbon monoxide interferes with all phases of the hydrogen metabolism in algae. It is supposed therefore to be a specific inhibitor for the hydrogenase system. 7. The "adaptation" to the hydrogen metabolism, which takes place if the algae are incubated anaerobically in hydrogen for several hours, is inhibited completely by very small amounts of cyanide. The adaptation reaction is more sensitive to cyanide than most of the other metabolic processes in the same cell. Correspondingly cyanide enhances the return to aerobic conditions, the "turnback," which occurs under the influence of light of high intensities. 8. Hydroxylamine, applied aerobically, inhibits the adaptation reaction to about the same degree as it inhibits photosynthesis. Photoreduction proceeds after the adaptation in presence of hydroxylamine only at a fraction of the rate that it would have if the poison were added later. 9. Hydroxylamine in concentrations of 10(-3)M protects the anaerobic metabolism against the return to aerobic photosynthesis which normally occurs under the influence of light of too high intensity. The protection is only relative and the higher the light intensity the more hydroxylamine is needed to keep photoreduction going. Once a "turnback" occurs in presence of much hydroxylamine all photochemical gas exchange comes to an end. PMID- 19873339 TI - FERMENTATIVE AND PHOTOCHEMICAL PRODUCTION OF HYDROGEN IN ALGAE. AB - 1.. After 2 hours of fermentation in nitrogen the metabolism of those algae which were found capable of photoreduction with hydrogen changes in such a way that molecular hydrogen is released from the cell in addition to carbon dioxide. 2. The amount of hydrogen formed anaerobically in the dark depends on the amount of some unknown reserve substance in the cell. More hydrogen is formed in presence of added glucose, but no proportionality has been found between the amount of substrate added and that of hydrogen formed. This is probably due to the fact that two types of fermentation reactions exist, with little or no connection between them. Whereas mainly unknown organic acids are formed during the autofermentation, the addition of glucose causes a considerable increase in the production of lactic acid. 3. Algae which have been fermenting for several hours in the dark produce upon illumination free hydrogen at several times the rate observed in the dark, provided carbon dioxide is absent. 4. Certain concentrations of dinitrophenol strongly inhibit the evolution of hydrogen in the dark. Fermentation then continues mainly as a reaction leading to lactic acid. In such poisoned algae the photochemical liberation of hydrogen still continues. 5. If the algae are poisoned with dinitrophenol the presence of carbon dioxide will not interfere with the photochemical evolution of hydrogen. 6. The amount of hydrogen released in this new photochemical reaction depends on the presence of an unknown hydrogen donor in the cell; it can be increased by the addition of glucose but not in proportion to the amount added. 7. The results obtained allow for a more correct explanation of the anaerobic induction period previously described for Scenedesmus and similar algae. The possibility of a photochemical evolution of hydrogen had not been taken into account in the earlier experiments. 8. The origin of the hydrogen released under the influence of light is discussed. PMID- 19873340 TI - REDUCTION OF CARBON DIOXIDE COUPLED WITH THE OXYHYDROGEN REACTION IN ALGAE. AB - 1. Unicellular algae possessing a hydrogenase system (Scenedesmus and other species), and having been adapted by anaerobic incubation to the hydrogen metabolism, reduce oxygen to water according to the equation O(2) + 2H(2) --> 2H(2)O. 2. The oxyhydrogen reaction proceeds undisturbed only in the presence of carbon dioxide, which simultaneously is reduced according to the equation CO(2) + 2H(2) --> H(2)O + (CH(2)O) = (carbohydrate). 3. The maximum yield of the induced reduction is one-half molecule of carbon dioxide reduced for each molecule of oxygen absorbed. 4. Partial reactions are recognizable in the course of the formation of water and it is with the absorption of the second equivalent of hydrogen that the carbon dioxide reduction appears to be coupled. 5. The velocity of the reaction increases in proportion to the partial pressure of oxygen, but only up to a certain point where any excess of oxygen causes the inactivation of the hydrogenase system. The reaction then ends prematurely. 6. During the oxyhydrogen reaction little or no oxygen is consumed for normal respiratory processes. 7. Small concentrations of cyanide, affecting neither photosynthesis nor photoreduction in the same cells, first inhibit the induced reduction of carbon dioxide and then lead to a complete inactivation of the hydrogenase system. 8. Hydroxylamine, added after adaptation, has either no inhibitory effect at all, or prevents solely the induced reduction of carbon dioxide without inactivating the hydrogenase system. 9. Dinitrophenol prevents the dark reduction of carbon dioxide while the reduction of oxygen continues to the formation of water. 10. Glucose diminishes the absorption of hydrogen, probably in its capacity as a competing hydrogen donor. 11. The induced reduction of carbon dioxide can be described as an oxido-reduction similar to that produced photochemically in the same cells. PMID- 19873341 TI - TYROSINASE AND PLANT RESPIRATION. AB - The evidence presented in this paper supports the conclusion that at least 85 per cent of the oxygen uptake of the respiring tissue of potato tuber enters the chemistry of the cell by way of a tyrosinase-catalyzed oxidation. The qualitative aspects of this conclusion are in agreement with the claim made by Boswell and Whiting. However, the evidence offered by them in support of this conclusion is shown to be inadequate. PMID- 19873342 TI - ACTION OF INHIBITORS ON HYDROGENASE IN AZOTOBACTER. AB - The inhibitors usually associated with the activity of the cytochrome oxidase system-cyanide and carbon monoxide-are also effective in reducing the oxidation of H(2) by intact cells of Azotobacter vinelandii. The hydrogenase system is more sensitive to CO than is the respiratory system. Oxidation of a carbon source and of hydrogen by Azotobacter cells is inhibited in a quantitatively different manner by the following compounds: sodium azide, hydroxylamine, sodium iodoacetate, and sodium fluoride. In every case, a concentration range which is definitely inhibitory for respiration has little or no effect on the hydrogenase activity. The differential inhibition by hydroxylamine explains certain observations in the literature which have been erroneously interpreted as demonstrating a specific inhibition by NH(2)OH of biological nitrogen fixation. This supposed demonstration has been offered as support for the hypothesis that NH(2)OH is an intermediate in the fixation reaction. The differential inhibitors can be used for detection of hydrogenase in cultures possessing a high endogenous respiration. The method is illustrated by an experiment with root nodule bacteria from pea and cowpea nodules. No hydrogenase was found in either. PMID- 19873343 TI - THE ELECTRICAL CONDUCTIVITY OF SODIUM AND POTASSIUM GUAIACOLATES IN GUAIACOL. AB - The data of the author and Uhlig, and new data, on the conductivity of sodium and of potassium guaiacolates in guaiacol at 25 degrees have been computed with an improved conductance equation which is valid to somewhat higher concentrations than the equations formerly used. The new constants are, Lambda(0) = 9.0, K = 2.8 x 10(-5) for sodium guaiacolate and Lambda(0) = 9.5, K = 3.4 x 10(-5) for potassium guaiacolate. PMID- 19873344 TI - DIFFUSION POTENTIALS IN MODELS AND IN LIVING CELLS. AB - The behavior of guaiacol resembles that of certain protoplasmic surfaces to such an extent that it can be advantageously used in models designed to imitate certain aspects of protoplasmic behavior. In these models the electrical potentials appear to consist of diffusion potentials and this may be true of certain living cells. In dealing with models we determine ionic mobilities and use these to predict potentials. In studying living cells we measure potentials and from these calculate ionic mobilities. The question arises, how far is this method justified. To test this we have treated guaiacol like a living cell, measuring potentials and from these estimating ionic mobilities. The results Justify the use of this method. This is of interest because the method is most useful in studying protoplasmic activity. In its extended form it enables us to follow changes in mobilities and in partition coefficients due to applied reagents and to metabolism. PMID- 19873345 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : V. THE INFLUENCE OF THE THICKNESS OF DRIED COLLODION MEMBRANES UPON THEIR ELECTROMOTIVE BEHAVIOR. AB - 1. Experiments were carried out to decide whether or not the electromotive properties of dried collodion membranes depend upon their thickness. 2. A number of dried collodion membranes of varying thickness, 3-160 micro, were prepared from collodion preparations of different electrochemical activity. The characteristic concentration potentials across them were measured and the means of these values determined for each thickness. 3. The characteristic concentration potentials across dried collodion membranes are a function of their thickness. The thinnest membranes yield in all cases the lowest concentration potentials; increasingly thicker membranes give increasingly higher potential values, until a constant value is reached which is characteristic of the particular collodion preparation used. With electrochemically active collodion, characteristic concentration potentials approaching the thermodynamically possible maximum are obtained with membranes of only 10 micro thickness, thinner membranes giving appreciably lower values. With two rather inactive commercial collodion preparations the characteristic concentration potential increases from about 30 mv. for membranes 3 micro thick to about 42 mv. for 20 micro membranes; still thicker membranes do not show a significant increase in the potential values. With a highly purified collodion preparation the constant maximum value was found to be about 32 mv., 4 micro thick membranes giving only about 22 mv. 4. These results do not support the homogeneous phase theory as applied to the dried collodion membrane. They are readily compatible with the micellar-structural theory. Several special possible cases of the latter as applied to the dried collodion membrane are discussed. PMID- 19873346 TI - ON THE CALCULATION OF "TURNOVER TIME" AND "TURNOVER RATE" FROM EXPERIMENTS INVOLVING THE USE OF LABELING AGENTS. AB - 1. A new method for the determination of an immediate precursor of a substance occurring in the animal body is presented. 2. Calculations on the quantitative determination of the rate of turnover of a substance and their application to experiments involving the use of labeling agents are given. These calculations take into account loss of the isotopic substance by way of breakdown or transport. PMID- 19873347 TI - THE TURNOVER RATE OF PHOSPHOLIPIDS IN THE PLASMA OF THE DOG AS MEASURED WITH RADIOACTIVE PHOSPHORUS. AB - 1. A method for the determination of turnover time and turnover rate of plasma phospholipid is presented. 2. During the postabsorptive state 5.2 to 8.0 mg. of phospholipid phosphorus are turned over per hour in the plasma of dogs weighing 6 9 kilos. 3. The amount of phospholipid in an organ that is supplied by plasma phospholipid per hour is calculated. PMID- 19873348 TI - SEDIMENTATION IN THE ANGLE CENTRIFUGE. AB - 1. Using hemocyanin from Limulus polyphemus as a test material, the process of sedimentation in the angle centrifuge, operating both in vacuum and in the open air, has been investigated. 2. Sedimentation in a given field of force was found less efficient when centrifugation was conducted in the open air, because of thermal convection. 3. Correlations have been made with results obtained in the analytical ultracentrifuge, and a theory of sedimentation in inclined tubes has been presented to explain the experimental results. 4. It has been shown that under proper conditions the angle centrifuge may be used for approximate determinations of particle size. 5. Recommendations, based mostly on experimental evidence, have been made for improving sedimentation and interpreting results. 6. To counteract convective disturbances of either thermal or inertial origin, a satisfactory method has been developed which consists of furnishing the fluid under study with a synthetic density gradient, formed with sucrose or some other non-sedimentable material. PMID- 19873349 TI - DERIVED PHOTOSENSITIVE PIGMENTS FROM INVERTEBRATE EYES. AB - The red pigment in the eyes of the squid, blue crab, and horseshoe crab becomes photosensitive when treated with formalin, and bleaches in the light. The resulting change in density is approximately symmetrical around a maximum at 480 mmicro in the blue green. This difference absorption spectrum is in rough agreement with the spectral sensitivity of the cephalopod eye and differs only slightly from the difference absorption spectrum of vertebrate visual purple. The formalin-sensitized pigment is not melanoid. Its bleaching in squid retinas releases large quantities of retinene. It is suggested that the light sensitivity of the normal squid photopigment may be independent of its light stability. PMID- 19873350 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : VI. THE PROTAMINE-COLLODION MEMBRANE, A NEW ELECTROPOSITIVE MEMBRANE. AB - 1. Strongly electropositive porous membranes were prepared by the adsorption of protamine (salmine) on porous collodion membranes. These membranes retain their electrochemical chracteristics for at least 12 months without change. 2. They are distinctly electropositive between pH 1 and 10, the range of most pronounced electropositive behavior occurring in solutions between pH 3 and pH 8. The filtration rates and ohmic resistance of these membranes do not differ significantly from similar uncoated membranes. 3. The porous protamine-collodion membranes show very pronounced positive anomalous osmosis, the observed effects with proper electrolytes being similar to those obtained with oxidized collodion membranes. They also show very conspicuous negative osmosis with strong acids. 4. Protamine-collodion membranes which correspond in their properties to the activated dried collodion membranes were prepared by the adsorption of protamine on porous collodion membranes followed by drying in air. The concentration potentials across such dried protamine-collodion membranes closely approach the thermodynamically possible maximum. PMID- 19873351 TI - SOME THERMOANALYTIC STUDIES OF ORGAN AND WHOLE ANIMAL RESPIRATION. AB - Data on the respiratory rates of frog liver, kidney, and striated muscle were obtained at various temperatures by the Warburg method. Fundamental differences in the curves of Q(O(O2) )vs. T exist among the tissues and between the tissues and the whole animal. The Arrhenius plots of these curves show that at least for some tissues the availability of oxygen at the tissue, as limited by the diffusion of gas through the skin and lungs, governs the Q(O(O2) ) of the tissue. Inferences are drawn regarding the comparative metabolism of the tissues and the fallacy of using whole animal Q(O(O2) ) alone as a metabolic index. PMID- 19873352 TI - STUDIES ON THE MECHANISM OF HYDROGEN TRANSPORT IN ANIMAL TISSUES : VI. INHIBITOR STUDIES WITH SUCCINIC DEHYDROGENASE. AB - 1. The mechanism of succinic dehydrogenase action was studied by means of inhibitors. 2. The enzyme is inhibited by a large number of diverse compounds whose only common denominator appears to be their ability to react with SH groups. These compounds include quinonoid structures, sulfhydryl reagents, sulfhydryl compounds, copper, zinc, selenite, and arsenite. 3. In contrast to the above inhibitors, the action of malonate does not appear to involve sulfhydryl groups and is explained on the basis of its affinity for the enzyme groups which react with the carboxyl groups of succinate. 4. The action of malonate and the sulfhydryl reactants is mutually exclusive, and this fact suggests the conclusion that the sulfhydryl group of the enzyme is located between the carboxyl affinity points. 5. On the basis of the deduced structure of the succinate-activating center of the enzyme, it is suggested that the enzyme may function by oscillating between the EnSH and EnS. forms, rather than by a thiol-disulfide equilibrium. PMID- 19873353 TI - THE ANTIPROTEOLYTIC ACTIVITY OF SERUM : I. THE NATURE AND EXPERIMENTAL VARIATION OF THE ANTIPROTEOLYTIC ACTIVITY OF SERUM. AB - 1. An equation is derived for the calculation of a constant which, experimental results indicate, may be a more reliable index of the antiproteolytic activity of serum than those equations hitherto used. 2. (a) Intramuscular administration of trypsin resulted in a slow rise in the antiproteolytic activity of the serum, followed by a lesser decline. (b) Intravenous administration resulted in no appreciable variation. (c) Oral administration resulted in a rapid rise, which was sustained during the period of administration. (d) Intramuscular, intravenous, or oral administration of denatured trypsin resulted in no appreciable variation. (e) The extent of the local necrosis following subcutaneous injection of trypsin varied inversely with the antiproteolytic activity of the serum. 3. The experimental results indicate that the products of protein hydrolysis in the intestine and parenterally are an important factor in the antiproteolytic activity of the serum. They also indicate that antibodies to trypsin are not an important factor in the antiproteolytic activity of the serum. PMID- 19873354 TI - THE ANTIPROTEOLYTIC ACTIVITY OF SERUM : II. PHYSIOLOGICAL SIGNIFICANCE. THE INFLUENCE OF PURIFIED TRYPSIN INHIBITOR ON THE COAGULATION OF THE BLOOD. AB - 1. Serum antitrypsin and pancreatic trypsin inhibitor inhibited the coagulation of plasma in vitro. 2. This could be largely prevented by trypsin. 3. The anticoagulant action of the trypsin inhibitor was apparently due to its antiprothrombic action. It had no appreciable antithrombic action. 4. Examination of the blood of two hemophiliacs indicated that the prolonged coagulation time of their blood is not due to an excess of trypsin inhibitor. 5. Examination of the blood of heparinized dogs indicated that heparin does not appreciably contribute to the antiproteolytic activity of the serum. PMID- 19873355 TI - THE ANTIPROTEOLYTIC ACTIVITY OF SERUM : III. PHYSIOLOGICAL SIGNIFICANCE. THE INFLUENCE OF TRYPSIN AND OF ANTIPROTEASE ON BACTERIAL GROWTH AND SULFONAMIDE ACTION. AB - 1. Heating diluted serum at 80 degrees C. for 10 minutes made it a better medium for bacterial growth. This is believed to have been at least partly due to destruction of the serum antiprotease. 2. Growth was accelerated, and proceeded further, in the presence of trypsin. 3. Growth was somewhat retarded in the presence of pancreatic trypsin inhibitor. 4. The bacteriostatic action of sulfathiazole in serum was reduced by heating the serum at 80 degrees C., and much more markedly (in any of the media studied) by adding trypsin. It was greater in serum and albumen than in peptone and meat infusion. 5. The significance of the experimental results was considered in relation to the possible influence of leucoprotease and of serum antiprotease on bacterial growth and sulfonamide action. PMID- 19873356 TI - STUDIES ON THE MECHANISM OF HYDROGEN TRANSPORT IN ANIMAL TISSUES : VII. INHIBITION BY RIBONUCLEASE. AB - 1. The effect of ribonuclease on various enzyme systems was studied as one approach to the problem of whether or not these enzymes are contained in macromolecules of ribonucleoprotein nature in protoplasm. 2. Ribonuclease inhibited CoI-cytochrome c reductase, succinic dehydrogenase, and cytochrome oxidase, all of which require cytochrome c in order to function. Ribonuclease did not act on cytochrome c. 3. Ribonuclease did not inhibit urease, xanthine oxidase, catalase, alkaline phosphatase, or adenosine triphosphatase under the conditions employed. 4. It was suggested that ribonuclease acted sterically by preventing contact between cytochrome c and its activating centers. 5. It was suggested that the enzymes inhibited may be contained in a ribonucleoprotein of macromolecular dimensions but that the enzymes not inhibited are not necessarily excluded from such a complex by the data presented. 6. Further evidence against the Szent-Gyorgyi theory of hydrogen transport was presented and discussed. PMID- 19873357 TI - PACEMAKERS IN NITELLA : III. ELECTRICAL ALTERNANS. AB - An electrical impulse traveling along a Nitella cell may produce a complete or a partial response. The two kinds of response may occur in regular alternation. The partial response varies greatly and may be so far reduced as to appear as a local thickening in the upstroke of the action curve, usually accompanied by a more or less pronounced hump. In consequence a considerable variety of action curves is produced. The observations show that different regions of the cell may react differently. PMID- 19873358 TI - THE EFFECT OF LOW OXYGEN TENSION ON TISSUE METABOLISM (RETINA). AB - Lactic acid production by rat retina in a medium containing phosphate was studied chemically. One half as much lactic acid was found as in a medium containing bicarbonate. In our experience the rate of respiration in a phosphate medium was sensitive to oxygen tension, for it was 38 per cent lower at 10 per cent and 51 per cent lower at 5 per cent oxygen than at 100 per cent oxygen. Previously Laser had reported no decrease in respiration at 5 per cent oxygen in phosphate medium. In phosphate medium, when the oxygen tension was varied, respiration and glycolysis bore a reciprocal relationship to each other. In bicarbonate medium, when the oxygen tension was lowered from 95 per cent to 5 per cent there was no significant change in the respiration, but glycolysis was increased nearly to the anaerobic level. This agrees with the earlier experiment of Laser in bicarbonate medium and adds support to his conclusion that the rate of glycolysis is controlled by oxygen tension rather than by the rate of respiration, under the conditions of the experiment. PMID- 19873359 TI - THE EFFECT OF CARBON DIOXIDE TENSION ON TISSUE METABOLISM (RETINA). AB - The metabolism of rat retina was found to be sensitive to the concentration of the carbon dioxide-bicarbonate buffer system. Increasing the carbon dioxide from 1 per cent to 5 per cent at constant pH nearly doubled both respiration and glycolysis. Increasing the carbon dioxide at constant pH from 5 per cent to 20 per cent had no effect on glycolysis, but depressed the Q(O(O2) ) from 31 to 19. In a medium containing glucose and the 1 per cent carbon dioxide-bicarbonate buffer, the addition of succinate increased the Q(O(O2) ) from 12 to 26, without affecting glycolysis. In a medium containing glucose and phosphate, succinate had no significant effect. PMID- 19873360 TI - THE INFLUENCE OF AMINO ACIDS ON THE REACTIVATION OF YEAST INVERTASE. AB - 1. Some 16 amino acids (not containing SH or S-S groups) did not affect the reactivation of yeast invertase inactivated by acid. 2. Cysteine, reduced glutathione, homocysteine, thiophenol, and thioglycollic acid accelerated the reactivation of yeast invertase. 3. Cystine, oxidized glutathione, and homocystine inhibited the reactivation of yeast invertase. 4. The compounds mentioned in 2 and 3 did not affect native invertase. 5. The use of compounds in which the H of the SH group of homocysteine was substituted by a methyl or benzyl nullified the accelerative effect. 6. The longer the cysteine remained in contact with the inactivating enzyme, the greater was the velocity of the reactivated invertase. 7. The per cent acceleration by cysteine is inversely proportional to the control rate. PMID- 19873361 TI - DIFFERENTIAL SENSITIVITY OF PROPHASE POLLEN TUBE CHROMOSOMES TO X-RAYS AND ULTRAVIOLET RADIATION. AB - 1. Through use of the pollen tube technique it has been possible to study the sensitivity of prophase stages to x-rays and ultraviolet, and to correlate the varying sensitivity with changes in the generative nucleus of Tradescantia. 2. Sensitivity to ultraviolet decreases from the 2 hour stage until at 11 hours after germination there is no further production of breaks. The 0 and 1 hour stages show a decreased sensitivity over the 2 hour stage but it has been suggested that this is not due to a decreased sensitivity but to shielding by the pollen wall. 3. Sensitivity to x-rays rises to a peak at the 4 hour stage, but then subsides until no breaks are realized (at a dose of 370.8 r) after the 10 hour stage. In this respect the effects of x-rays and ultraviolet are similar. Each type of x-ray break shows its own individual trend. 4. Correlation of x-ray breaks with changes in the generative nucleus indicates that the important events determining the sensitivity of the chromosomes to breakage are the uptake of water at the time of germination and the movement involved in spiralization. The total absence of breaks after the 11 hour stage is not understood. 5. The changing sensitivity to ultraviolet may depend on any one or all of three factors: (a) the nucleic acid cycle, (b) changes in the matrix, and (c) the number of subdivisions in the chromosome. These are discussed although their relative importance is not known. PMID- 19873362 TI - PHYSICAL PROPERTIES OF THE ALLANTOIC AND AMNIOTIC FLUIDS OF THE CHICK : I. SPECIFIC CONDUCTANCE. AB - 1. The specific conductance of the allantoic and amniotic fluids of the developing chick has been determined over the period of incubation between the 7th and 19th days. 2. Changes in this property have been related to changes in the chemical composition of these two fluids. 3. These conductance values are of importance in that they show the relation between ionized and un-ionized materials present in the two fluids. PMID- 19873363 TI - PHYSICAL PROPERTIES OF THE ALLANTOIC AND AMNIOTIC FLUIDS OF THE CHICK : II. HYDROGEN ION CONCENTRATION. AB - 1. The hydrogen ion concentration of the allantoic and amniotic fluids of the developing chick has been determined over the period of incubation between the 7th and 19th days using the glass electrode technique. 2. Changes in this property have been related to changes in the chemical composition of these two fluids. 3. The results of this investigation have been compared with those obtained by other workers. Excellent confirmation has been afforded the work of Yamada, whereas the work of Aggazzotti, which has long been accepted, is shown to be in error. PMID- 19873364 TI - NATIVE AND REGENERATED BOVINE ALBUMIN : I. PREPARATION AND PHYSICOCHEMICAL PROPERTIES. AB - 1. Whole bovine albumin, homogeneous in diffusion and sedimentation, and essentially homogeneous in electrophoresis, has been prepared by a method involving ammonium sulfate precipitation of the globulins in the cold and of the albumin at room temperature, isoelectric precipitation of the euglobulins, and reprecipitation of the albumin. 2. The product has been characterized by chemical analysis and by viscosity, diffusion, sedimentation, and electrophoresis measurements. The carbohydrate content is 0.38 per cent, the nitrogen content, 15.2 per cent. The molecular shape approximates that of a prolate ellipsoid with an axial ratio of 3.1, assuming 33 per cent hydration; the average molecular weight is 65,000. 3. Bovine albumin is readily denatured by concentrated solutions of urea or guanidine hydrochloride, gross changes in molecular shape resulting. 4. Regeneration of bovine albumin denatured in solutions of 8 M urea or guanidine hydrochloride yields a material closely resembling the native in carbohydrate content, in molecular size and shape, and in electrophoretic properties. However, the regenerated protein differs from the native in susceptibility to tryptic digestion, and, in this respect, appears to be in a denatured state. 5. In 8 M solutions of guanidine hydrochloride a limiting yield of regenerated albumin equivalent to 95 per cent of the original protein is approached. 6. Bovine crystalbumin, a crystalline carbohydrate-free fraction of the whole albumin, appears to be more susceptible to denaturation than whole bovine albumin. PMID- 19873365 TI - NATIVE AND REGENERATED BOVINE ALBUMIN : II. IMMUNOLOGICAL PROPERTIES. AB - 1. The effects of regeneration of whole bovine albumin on antigenic activity and serological specificity were determined by precipitin measurements on rabbit antisera to (1) native whole albumin, (2) albumin regenerated from 8 M urea, and (3) albumin regenerated from 8 M guanidine hydrochloride. 2. While numerically the mean antibody response to these three antigens was found to decrease in the order named, only the difference in antigenic activity between native and guanidine hydrochloride-regenerated albumin was statistically significant. Native, crystalline, carbohydrate-free albumin (crystalbumin) was considerably less antigenic than native whole bovine albumin, its activity being comparable to, if not less than, that observed for guanidine hydrochloride-regenerated whole albumin. 3. All four antigens were immunologically equivalent. 4. The antigenic activity of these proteins is discussed in terms of protein structure and carbohydrate content. PMID- 19873366 TI - EFFECTS OF pH AND OF VARIOUS CONCENTRATIONS OF SODIUM, POTASSIUM, AND CALCIUM CHLORIDE ON MUSCULAR ACTIVITY OF THE ISOLATED CROP OF PERIPLANETA AMERICANA (ORTHOPTERA). AB - 1. Twenty-five solutions which contained KCl (0.0, 0.2, 0.4, 0.6, and 0.8 gm. per liter), in combination with CaCl(2) (0.0, 0.2, 0.4, 0.6, and 0.8 gm. per liter), 10.0 gm. of NaCl, and 0.2 gm. of NaHCO(3) per liter of solution were tested in order to determine satisfactory KCl/CaCl(2) ratios in an insect physiological salt mixture for the maintenance of muscular activity by the isolated crop of the American roach. Satisfactory activity products (0.390 to 0.549) were obtained in seven mixtures with KCl/CaCl(2) ratios of 0.2/0.2, 0.4/0.4, 0.6/0.6, 0.8/0.8, 0.2/0.4, 0.4/0.6, and 0.6/0.8, expressed as gram per liter. These ratios lie between 0.50 and 1.00. In solutions which contained calcium, but no potassium, approximately 50 per cent of the crops exhibited an initial tone increase and were arrested in rigor. See Fig. 2. In solutions which contained potassium, but no calcium, all crops showed an initial loss of tone and arrest in relaxation. See Fig. 2. 2. Seven KCl/CaCl(2) ratios (see paragraph 1 above) were tested with eight NaCl concentrations (1.0, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, and 1.8 per cent) at a pH of 8.0. In these mixtures, the ones with KCl/CaCl(2) ratios of less than 1.0 produced higher activity products than those with ratios equal to 1.00. The highest average activity product (0.849) was obtained in the solutions with 0.2 gm. of KCl and 0.4 gm. of CaCl(2) per liter. 3. Four KCl/CaCl(2) ratios (0.2/0.2, 0.4/0.4, 0.2/0.4, and 0.4/0.6 gm. per liter) were tested with 1.4, 1.5, and 1.6 per cent NaCl at a pH of 7.5. When analyzed with data from comparable solutions at a pH of 8.0, it was found that 1.4 per cent NaCl afforded an optimum environment for isolated crop activity. 4. Effects of hydrogen and hydroxyl ion concentrations were studied at pH values of 6.8, 7.5, 8.0, and 8.9. The highest average activity product, 1.011, was produced at a pH of about 8.0. 5. A satisfactory physiological salt solution for the isolated foregut of the American roach, Periplaneta americana, would contain 14.0 gm. of NaCl, 0.4 gm. of CaCl(2), 0.2 gm. of KCl, and 0.2 gm. of NaHCO(3) per liter of solution. This mixture should have a pH value between 7.8 and 8.2. 6. Durations of crop activity extending over periods as long as 25 hours were quite common, and several crops maintained contractions for more than 30 hours. The greatest longevity was for crop 814, from a female, which continued activity for slightly more than 47 hours. 7. A significant difference between the activity products of the crops from males and the crops from females was recorded. Although there was not a significant difference in the amount of food ingested by males and females, 12 hours after feeding there was more food in the females' crops, and the food progressed more rapidly through the males' crops than through the females'. In addition, crops from the two sexes reacted differently to the effects of day old solutions. This sex difference is apparently related to an inherently increased activity of the crop from the male roach. PMID- 19873367 TI - ZONE BEHAVIOR OF ENZYMES : ILLUSTRATED BY THE EFFECT OF DISSOCIATION CONSTANT AND DILUTION ON THE SYSTEM CHOLINESTERASE-PHYSOSTIGMINE. AB - 1. The kinetics of the reversible combination of one enzyme center with one molecule of a substrate or inhibitor is treated as a true bimolecular instead of a pseudomonomolecular reaction. The general equations describing such a reaction are presented and analyzed algebraically and graphically. 2. A new term, "specific concentration," is introduced to denote the concentration of reactants in units equal to the dissociation constant. Its use makes the kinetic equations universally applicable to all reversible systems of the given type. 3. It is shown that such a system exhibits three "zones" of behavior. Each zone is characterized and shown to exhibit significant differences in the function relating the concentrations of the components of the system at equilibrium. The zone boundaries are rigorously defined in terms of the specific enzyme concentration, for the mathematical error tolerable with a given experimental accuracy; and approximate boundaries for practical use are proposed. 4. The classical treatment of enzyme kinetics is shown to be a limiting case valid only for low specific enzyme concentrations (zone A) and to be inapplicable in a number of systems whose dissociation constants are very small or whose molar enzyme concentrations are very great, and in which, therefore, the specific enzyme concentrations are large. See Table I for a summary of zone differences. 5. In an enzyme system containing substrate or inhibitor, dilution before determination of reaction velocities is shown to be a crucial operation, entailing large changes in the fraction of enzyme in the form of a complex. The changes in fractional activity or inhibition with dilution are shown to be a function of specific enzyme concentration, the dilution factor, and the fraction of enzyme initially in the form of complex. Equations are given permitting the calculation of the state of the system at any concentration. The errors introduced into physiological work by failure to take the dilution effect into account are pointed out. 6. Experimental data are presented showing that the system composed of serum cholinesterase and physostigmine behaves as predicted by the dilution effect equations. 7. Two other conclusions of practical pharmacological importance are drawn from the theory of zone behavior: (a) The finding that a biological response is a linear function of the dose of a drug does not necessarily mean that the reaction is irreversible, but only that if reversible, the reactant with which the drug combines has a high specific concentration. (b) If a tissue enzyme has a high specific concentration, all reversible inhibitors will be equally potent in combining with it, regardless of their relative potency in dilute systems; provided only that their dissociation constants are within certain broad limits. 8. It is shown how the type of analysis here applied to bimolecular reactions can be applied in toto to systems of the type E + nX left harpoon over right harpoon EX(n), where n molecules of substrate or inhibitor unite with one enzyme center. The zone boundaries and the magnitude of the dilution effect change with n, but the general characteristics of the zones are the same for all values of n. 9. Since the analysis is based only on mass law assumptions, it is applicable to any system that is formally analogous to the one here treated. PMID- 19873368 TI - THE MECHANISM OF THE INHIBITION OF HEMOLYSIS. AB - The principal conclusion of this investigation is that the inhibitory effect of plasma or serum on hemolysis by saponin and lysins of the same type is similar in nature to the inhibitory effects of certain sugars and electrolytes, which again are similar to the acceleratory effects produced by indol, benzene, and other substances already studied. All these effects, both inhibitory and acceleratory, are the result of reactions between the inhibitors or accelerators and those components of the red cell membrane which are broken down by lysins. The inhibitory effect of plasma on saponin hemolysis has a number of properties in common with the inhibition produced by sugars and electrolytes and with accelerations in general. (a) The temperature coefficient is small and negative. (b) The extent of the inhibition depends on the type of red cell used in the hemolytic system. (c) The most satisfactory measure of the extent of the inhibition, the constant R, is a function of the concentration of lysin in the system, and (d) R is a linear function of the quantity of inhibitor present. It is also shown that the inhibitory effect of plasma, and serum is not entirely dependent on its protein content. The process underlying the phenomenon of lysis and its acceleration or inhibition seems to be one in which the lysin reacts with a component or components of the cell membrane in such a way as to break down its semipermeability to hemoglobin, and in which the accelerator or inhibitor also reacts with the same component in such a way as to increase or decrease the effectiveness of the lysin in producing breakdown. The membrane is considered as being an ultrastructure made up of small areas or spots of varying degrees of resistance to breakdown, the resistances being distributed according to a negatively skew type of frequency curve, and the process of lysis seems to begin with the least resistant spots breaking down first. These spots may be arranged in some regular spatial pattern, and the membrane has also to be regarded as possessing spots of varying rigidity of form. The accelerator or inhibitor changes the resistance of every reactive spot in the ultrastructure by a factor R, which suggests that acceleration and inhibition are results of some over-all effect, such as that of changing the extent to which lysin is concentrated at the surface or partitioned between the material of the membrane and the surrounding fluid. Some kind of combination between the accelerator or inhibitor and the material of the ultrastructure is presumably involved; at first the combination seems to be a loose one and partly reversible, but later some of the loose links are replaced by more permanent combinations involving the same types of bond as are broken down by the lysins themselves. PMID- 19873369 TI - AN EXPERIMENTAL SEPARATION OF OXYGEN LIBERATION FROM CARBON DIOXIDE FIXATION IN PHOTOSYNTHESIS BY CHLORELLA. AB - Using intact cells of Chlorella pyrenoidosa it is possible to obtain oxygen by the reduction of certain reducible materials other than carbon dioxide. Of these, benzaldehyde was studied in some detail. This reduction does not involve the production of carbon dioxide from the benzaldehyde. Stoichiometrical relationships as expressed by the following equation: 2C(6)H(5)CHO + 2H(2)O --> 2C(6)H(5)CH(2)OH + O(2) are somewhat difficult to obtain because the benzaldehyde can disappear from the reaction mixtures by dark reactions. The technique is now available which permits detailed studies of the oxygen-liberating mechanisms in photosynthesis. PMID- 19873370 TI - PHYSICAL PROPERTIES OF THE ALLANTOIC AND AMNIOTIC FLUIDS OF THE CHICK : III. SURFACE TENSION. AB - The study of the changes occurring during incubation in the surface tension of the two extra-embryonic fluids of the hen's egg has yielded results which in part harmonize with previous studies of the chemical and physical nature of these liquids, and which in part are quite inexplicable in the light of these investigations. The necessity for a more thorough chemical analysis of these fluids is clearly indicated before any exact evaluation of their significance to the developing embryo can be made. PMID- 19873371 TI - POTENTIAL, IMPEDANCE, AND RECTIFICATION IN MEMBRANES. AB - Impedance and potential measurements have been made on a number of artificial membranes. Impedance changes were determined as functions of current and of the composition of the environmental solutions. It was shown that rectification is present in asymmetrical systems and that it increases with the membrane potential. The behavior in pairs of solutions of the same salt at different concentrations has formed the basis for the studies although a few experiments with different salts at the same concentrations gave results consistent with the conclusions drawn. A theoretical picture has been presented based on the use of the general kinetic equations for ion motion under the influence of diffusion and electrical forces and on a consideration of possible membrane structures. The equations have been solved for two very simple cases; one based on the assumption of microscopic electroneutrality, and the other on the assumption of a constant electric field. The latter was found to give better results than the former in interpreting the data on potentials and rectification, showing agreement, however, of the right order of magnitude only. Although the indications are that a careful treatment of boundary conditions may result in better agreement with experiment, no attempt has been made to carry this through since the data now available are not sufficiently complete or reproducible. Applications of the second theoretical case to the squid giant axon have been made showing qualitative agreement with the rectification properties and very good agreement with the membrane potential data. PMID- 19873372 TI - NATURE OF THE ACTION CURRENT IN NITELLA : V. PARTIAL RESPONSE AND THE ALL-OR-NONE LAW. AB - When a stimulus arrives before recovery is complete there may be no response or only a partial response. A typical response appears to involve an immediate loss of potential at the inner protoplasmic surface but not at the outer surface. As long as recovery is incomplete only a part of the total potential is located at the inner protoplasmic surface and the loss of this part of the total potential can cause only a partial response; i.e., one of smaller magnitude than the normal. Even after the action curve has returned to the base line recovery may be incomplete and the response only a partial one. The return of the action curve to the base line means a recovery of total potential but if part of this is located at the outer protoplasmic surface and if this part is not lost when stimulation occurs the response can be only a partial one. During recovery there is a shift of potential from the outer to the inner protoplasmic surface. Not until this shift is completed can recovery be called complete. The response to stimulation then becomes normal because the loss of potential reaches the normal amount. In many cases the partial responses appear to conform to the all-or-none law. In other cases this is doubtful. PMID- 19873373 TI - DENATURATION CHANGES IN EGG ALBUMIN WITH UREA, RADIATION, AND HEAT. AB - The extent of urea denaturation depends on the concentration of protein and urea and also on the temperature of the solution. Egg albumin solutions (0.9 per cent) are not denatured by 20 per cent urea, denature slowly with 25 per cent urea, and denature rapidly with 35 per cent urea at room temperature. At a higher temperature 30 per cent urea is rapidly effective. Denaturation of the egg albumin molecule by radiation or by heat is accompanied by structural changes as evidenced by optical rotation values, but is not accompanied by association or dissociation of the molecule in the pH range outside the zone in which aggregation follows denaturation. Denaturation of the egg albumin molecule by urea produces no change in optical rotation until the concentration of urea is high enough to dissociate the molecule. In the presence of urea a urea-protein complex is formed in which the protein is denatured but cannot flocculate because of the dispersive action of the urea. This prevents flocculation of proteins exposed to radiation and subsequent heating to 40 degrees C. as the urea-protein complex is not broken down at a temperature of 40 degrees C. The presence of urea therefore prevents the flocculation of proteins denatured by radiation. The urea protein complex is broken down by heating to 55-58 degrees C. so that the molecules aggregate at a temperature below the temperature of rapid heat denaturation. This appears to be an acceleration of heat denaturation or a lowering of the heat denaturation temperature, but in reality is an effect of heat on the urea-protein complex which frees the urea-denatured protein and permits its aggregation. PMID- 19873374 TI - THE EFFECT OF TEMPERATURE ON THE RATE OF HYDROLYSIS OF TRIGLYCERIDES BY PANCREATIC LIPASE. AB - 1. The temperature characteristics for the hydrolysis of various concentrations of tributyrin, trivalerin, tricaproin, triheptylin, and tricaprylin have been determined. 2. The micro values for the hydrolysis of all concentrations of tributyrin by pancreatic lipase, except the most dilute, were found to be constant within the experimental error, 8,500 +/- 1,000. 3. The temperature characteristics for the hydrolysis of trivalerin, tricaproin, triheptylin, and tricaprylin varied from approximately 8,500 +/- 1,000 for the high concentrations to 12,400, 20,000, 22,400, and 23,700 respectively for the most dilute concentration of each. 4. An interpretation of these results was presented. PMID- 19873375 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : IX. FLICKER RELATIONS WITHIN THE FOVEA. AB - Flicker response contours (F vs. log I(m)) for a square image subtending 0.602 degrees on a side, located in the fovea, are simplex probability integrals for a "white" and for four (five) spectral regions filtered from this white, and with different light-time fractions in the flash cycle. The subjective phenomena (the appearance of the field, the intensity threshold for color, and others) at the fusion points along these contours parallel in a variety of ways those obtained on duplex flicker contours resulting from the use of larger or eccentrically placed flickered images. These phenomena therefore cannot be held to indicate involvements of "rod" excitation. The scatter of the index of variation of I(1) is such as to demonstrate the full participation of all the potentially excitable neural units at all levels of flash frequency, for each kind of light. The magnitude of this scatter, a measure of neural integration in visual performance, is a function of the number of these units (with F(max.) nearly constant); the two quantities vary together when wave-length composition of light is altered. The properties of the contours for a white light and for the spectral regions filtered from it show that, for the image within the fovea, different numbers of units are excitable in flicker recognition according to the wave-length band used, and different mean frequencies of elements of effect under fixed conditions. The changes in the mean intensity for activation of these units as a function of the light-time fraction in the flash cycle are correlated with the numbers of these units; when this is corrected for, it is pointed out that despite the differences in shape of F vs. log I it cannot be concluded that the mechanism of excitation differs for different wave-lengths. It is indicated that "white" must be regarded as a synthesis, not a mere summation, of effects due to different spectral regions. Certain differences are pointed to as between foveal and more peripheral regions tested, and as between observers differing in the degree of the "yellow spot effect," with regard to the relative effects of wave length and of image area. A general consequence is the outlining of conditions required for the precise comparison of excitabilities as a function of wave length in the multivariate visual system. PMID- 19873376 TI - STUDIES OF THE INNER AND OUTER PROTOPLASMIC SURFACES OF LARGE PLANT CELLS : I. PLASMOLYSIS DUE TO SALTS. AB - In Nitella, Chara, Hydrodictyon, and Valonia the inner and outer non-aqueous protoplasmic surface layers can be separated by certain plasmolytic agents which penetrate the outer surface more rapidly than the inner and hence raise the osmotic pressure of the protoplasm lying between them and cause it to increase in thickness by taking up water from the central vacuole. We may therefore conclude that the two surfaces differ. This idea is confirmed by earlier electrical measurements which show that when sap is placed outside the cell the chain See PDF for Structure produces an E.M.F. of several millivolts. PMID- 19873377 TI - THE QUANTITATIVE EFFECT OF X-RAYS ON ASCORBIC ACID IN SIMPLE SOLUTION AND IN MIXTURES OF NATURALLY OCCURRING COMPOUNDS. AB - Data on the x-ray induced reaction of ascorbic acid in simple inorganic solution, in solutions containing serum albumin, in plasma, and in muscle have been presented. The reaction occurred in the presence of serum albumin and in human plasma but was relatively small in excised rat muscle. PMID- 19873378 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : VII. WATER UPTAKE AND SWELLING OF COLLODION MEMBRANES IN WATER AND SOLUTIONS OF STRONG INORGANIC ELECTROLYTES. AB - 1. The assumption, has generally been made that collodion membranes are rigid and non-swelling in water and aqueous solutions of strong electrolytes, and considerable uncertainty exists as to the manner in which water is taken up by "dried" collodion membranes. In approaching these problems experimentally, the weight and volume changes of collodion membranes when placed in water and when transferred from water to solutions of strong electrolytes were determined. 2. Dried collodion membranes swell reversibly to an appreciable extent when placed in water, the swelling varying from 5 to 11 per cent depending on the brand of collodion. The water uptake and swelling of oxidized collodion is the same as the original unoxidized preparation. 3. The water uptake as determined by the weight increase is larger than could be accounted for by the volume increase, swelling accounting for only 60 to 70 per cent of the water taken up by the membranes. 4. When the "water-wetted dried" collodion membranes were transferred from water to solutions of various strong electrolytes, there was no detectable change in volume. Similarly, when the "porous" membranes were transferred from water to solutions of strong electrolytes, there was no significant volume change. 5. When dried collodion membranes swell in water, some of the water becomes "bound" water, and both intramicellar and intermicellar swelling seem to occur. Therefore, neither the weight increase nor the volume increase nor their difference can be taken as a measure of the true pore space of the membrane. It is concluded that the important problem is not the absolute water content, but how much water in the water-wet membranes is available in useful pathways for the different solutes. PMID- 19873379 TI - A MODEL OF THE POTASSIUM EFFECT. AB - The protoplasm of certain cells is able to distinguish electrically between K(+) and Na(+). This has been called the potassium effect. This is illustrated by experiments with Nitella. When 0.01 M KCl which has stood in contact with Nitella is replaced by 0.01 M NaCl the P.D. changes in a positive direction by an amount which varies between 30 and 95 mv. This ability to distinguish between K(+) and Na(+) disappears with the removal of an organic substance from the cell. The amount of this substance is doubtless too small to make it possible to obtain enough for analysis. An attempt has therefore been made to find an organic compound which can produce similar effects. It is found that when M/1 KCl in contact with nitrobenzene (previously shaken with M/1 KCl) is replaced by M/1 NaCl the potential changes in a positive direction to the extent of 67 mv. which compares favorably with the values found in Nitella. This is not due to a greater mobility in nitrobenzene of K(+) as compared with Na(+): this is evident from measurements of concentration effects with nitrobenzene (M/1 KCl vs. M/10 KCl and M/1 NaCl vs. M/10 NaCl). It might be brought about if KCl produced in nitrobenzene a sufficient preponderance of ions (simple or complex) as compared with NaCl. Whether this occurs could not be determined but it was found that nitrobenzene shaken with M/1 KCl has a higher conductivity than when shaken with M/1 NaCl. Measurements with salicylates showed that K-salicylate has a partition coefficient about 11.7 times as great as that of Na-salicylate. It was also found that when M/1 K-salicylate in contact with nitrobenzene (previously shaken with M/1 K-salicylate) is replaced by M/1 Na-salicylate there is a change of potential in a positive direction amounting to 56 mv. To what extent phase boundary potentials may enter into the observed values cannot be determined at present. The model resembles the Nitella cell in that RbCl and KCl are negative to NH(4)Cl which in turn is negative to NaCl and still more so to LiCl (in the model CsCl is negative to KCl but in Nitella it is positive). It likewise resembles Nitella in that the potassium effect is lessened by the addition of guaiacol. PMID- 19873380 TI - HOMEOSTATIC ADJUSTMENTS AFTER EXERCISE : I. ACID-BASE EQUILIBRIUM OF THE BLOOD. AB - The rate at which displacement and recovery of the acid-base equilibrium of the blood occur in young adult males subjected to short periods of maximal exertion has been determined. Displacement of acid-base equilibrium produced by severe exercise is along the fixed acid path, similar to the path of displacement produced by ingestion of acidifying agents such as ammonium chloride. Maximum displacement of the acid-base equilibrium is not reached until 7 to 10 minutes after the cessation of exercise. By this time over 50 per cent of the displacement in oxygen consumption, respiratory volume, and blood pressure have disappeared. A much greater metabolic acidosis was produced by exercise than could be induced by the oral administration of ammonium chloride. Recovery from the metabolic acidosis produced by exercise was much more rapid (10 times) than was recovery from the acidosis produced by ammonium chloride. After exercise the pH, returned to normal values more rapidly than did the bicarbonate content of the serum. PMID- 19873381 TI - A PHYSICAL THEORY OF ACID ANION DISPLACEMENT AND RECOVERY FOLLOWING EXERCISE. AB - A simple theoretical model has been presented whose behavior duplicates the variation in bicarbonate ion concentration in the blood following exercise. Methods for the evaluation of the constants of rational equations to describe the concentration in muscle cells, in blood plasma, and in removal cells, of the anions produced in exercise have been devised. These methods have been applied to experimental data from 23 experiments, and a close agreement between the observed and theoretically predicted values for blood plasma has been found. From the mathematical analysis of the data values for permeability of acid anions produced in exercise have been estimated as 75 x 10(-5) and 5.9 x 10(-5) cm. per sec. between muscle cell and blood (extracellular fluid) and between blood plasma and removal cells respectively. PMID- 19873382 TI - THE PREPARATION AND PROPERTIES OF HIGHLY PURIFIED ASCORBIC ACID OXIDASE. AB - 1. A method is described for the preparation of a highly purified ascorbic acid oxidase containing 0.24 per cent copper. 2. Using comparable activity measurements, this oxidase is about one and a half times as active on a dry weight basis as the hitherto most highly purified preparation described by Lovett Janison and Nelson. The latter contained 0.15 per cent copper. 3. The oxidase activity is proportional to the copper content and the proportionality factor is the same as that reported by Lovett-Janison and Nelson. 4. When dialyzed free of salt, the blue concentrated oxidase solutions precipitate a dark green-blue protein which carries the activity. This may be prevented by keeping the concentrated solutions about 0.1 M in Na(2)HPO(4). 5. When highly diluted for activity measurements the oxidase rapidly loses activity (irreversibly) previous to the measurement, unless the dilution is made with a dilute inert protein (gelatin) solution. Therefore activity values obtained using such gelatin stabilized dilute solutions of the oxidase run considerably higher than values obtained by the Lovett-Janison and Nelson technique. 6. The effect of pH and substrate concentration on the activity of the purified oxidase in the presence and absence of inert protein was studied. PMID- 19873383 TI - ON THE INACTIVATION OF ASCORBIC ACID OXIDASE. AB - 1. In the absence of protective agents, highly purified ascorbic acid oxidase is rapidly inactivated during the enzymatic oxidation of ascorbic acid under optimum experimental conditions. This inactivation, called reaction inactivation to distinguish it from the loss in enzyme activity that frequently occurs in diluted solutions of the oxidase prior to the reaction, is indicated by incomplete oxidation of the ascorbic acid as measured by oxygen uptake; i.e., "inactivation totals." 2. A minor portion of the reaction inactivation appears to be due to environmental factors such as rate of shaking of the manometers, pH of the system, substrate concentration, and oxidase concentration. The presence of inert protein (gelatin) in the system ameliorates the environmental inactivation to a considerable extent, and variation of the above factors in the presence of gelatin has much less effect on the inactivation totals than in the absence of gelatin. 3. A major portion of the reaction inactivation of the oxidase appears to be due to some factor inherent in the ascorbic acid-ascorbic acid oxidase oxygen system, possibly a highly reactive "redox" form of oxygen other than H(2)O(2) or H(2)O. The inactivation cannot be attributed to dehydroascorbic acid, the oxidation product of ascorbic acid. 4. Small amounts of native catalase, native peroxidase, native or denatured methemoglobin, and hemin when added to the system, markedly protect the oxidase against inactivation. Cytochrome c has no such protective action. Likewise proteins such as egg albumin, gelatin, denatured catalase, or denatured peroxidase show no such protective action. 5. None of the protective agents mentioned above affect the initial rate of oxygen uptake or change the total oxygen absorbed for complete oxidation of the ascorbic acid, and hence do not act by removal of hydrogen peroxide, per se. 6. Sodium azide and hydroxylamine hydrochloride which inhibit catalase and peroxidase activity also inhibit the protective action of these iron-porphyrin enzymes. PMID- 19873384 TI - STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS : I. GENERAL BEHAVIOUR OF PROTEINS SUBJECTED TO SHEAR. AB - 1. A coaxial viscosimeter which permits the simultaneous determination of relative and anomalous viscosity and of flow-birefringence is described. Flow anomaly and flow-birefringence are regarded as characteristic of elongated micelles and molecules. 2. Such methods have been applied to dilute solutions of proteins. The conditions under which the coaxial (Couette) viscosimeter measures the viscosity of the bulk phase and the surface film phase respectively have been investigated and are described. 3. The general behaviour of protein solutions subjected to shear is summarised. PMID- 19873385 TI - STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS : II. ON DILUTE SOLUTIONS OF PROTEINS FROM EMBRYONIC AND OTHER TISSUES. AB - 1. An extensive investigation has been made of protein particle shape using the methods of flow-birefringence and anomalous viscosity measurement in the coaxial cell. 2. As a result of investigations on a number of proteins, it is concluded that they may be divided into four groups. Group A consists of those which show flow-anomaly both in the bulk phase and in the surface film. These also show flow birefringence in the bulk phase. EXAMPLES: tobacco mosaic disease virus nucleoprotein; myosin. Though corpuscular proteins, they have elongated particles before denaturation. Group B consists of those which show flow-anomaly only (in the first instance) in the surface film, and no flow-birefringence in the bulk phase. They are probably close to spherical in shape in solution, but form elongated particles as they denature in the surface film. After this process has been completed, they may show flow-anomaly also in the bulk phase. Some proteins show flow-anomaly in the surface film immediately it forms, others only show it after a certain time has elapsed for the building up of the film. We designate the former as group B(1) and the latter as group B(2). Group B(1), immediate surface film flow-anomaly. EXAMPLES: serum euglobulin, amphibian embryo euglobulin b. Group B(2), slowly appearing surface film flow-anomaly. After the film has once been fully formed and then dispersed by shaking, the solution may have the properties of that of a protein in group B(1); i.e., anomalous flow in the film may occur immediately on testing in the viscosimeter. EXAMPLES: avian ovalbumin, amphibian embryo pseudoglobulin. Group C consists of those proteins which show flow-anomaly neither in the bulk phase nor in the surface film, under the conditions used by us. They are probably close to spherical in shape. EXAMPLES: insulin, methaemoglobin, amphibian embryo euglobulin c, mucoproteins. 3. The theoretical significance of protein fibre molecules, whether native or formed by denaturation in the living cell, is discussed, especially in relation to experimental morphology and cytology. PMID- 19873386 TI - THE OSMOTIC BEHAVIOR OF CRENATED RED CELLS. AB - The anomalously small swelling which the red cells of human oxalated blood undergo in hypotonic plasma is related to the extent to which the cells are crenated. Reasons are given for regarding crenation as corresponding to gelation, and the bulk modulus for crenated cells, calculated from the measurements of swelling in hypotonic plasma, is shown to be of the same order as that for gelatin gels. PMID- 19873387 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : X. MODIFICATIONS OF THE FLICKER RESPONSE CONTOUR, AND THE SIGNIFICANCE OF THE AVIAN PECTEN. AB - 1. When there is projected on the retina (man, monocularly) the shadow of a grid which forms a visual field in several distinct pieces (not including the fovea in the present tests), the ordinary properties of the flicker recognition contour (F vs. log I) as a function of the light-time cycle fraction (t(L)) can be markedly disturbed. In the present experiments flicker was produced by the rotation of a cylinder with opaque vertical stripes. In the absence of such a grid shadow the "cone" segments of the contours form a set in which F(max.) and the abscissa of inflection are opposite but rectilinear functions of t(L), while the third parameter of the probability integral (sigma'(log I)) remains constant. This is the case also with diverse other animals tested. In the data with the grid, however, analysis shows that even for low values of t(L) (up to 0.50) there occurs an enhancement of the production of elements of neural effect, so that F(max.) rises rather than falls as ordinarily with increase of t(L), although sigma'(log I) stays constant and hence the total number of acting units is presumed not to change. This constitutes valid evidence for neural integration of effects due to the illumination of separated retinal patches. Beginning at t(L) = 0.75, and at 0.90, the slope of the "cone" curve is sharply increased, and the maximum F is far above its position in the absence of the grid. The decrease of sigma'(log I) (the slope constant) signifies, in terms of other information, an increase in the number of acting cone units. The abscissa of inflection is also much lowered, relatively, whereas without the grid it increases as t(L) is made larger. These effects correspond subjectively to the fact that at the end-point flicker is most pronounced, on the "cone" curve, along the edges of the grid shadow where contrast is particularly evident with the longer light-times. The "rod" portion of the F - log I contour is not specifically affected by the presence of the grid shadow. Its form is obtainable at t(L) = 0.90 free from the influence of summating "cone" contributions, because then almost no overlapping occurs. Analysis shows that when overlapping does occur a certain number of rod units are inhibited by concurrent cone excitation, and that the mean contribution of elements of neural action from each of the non-inhibited units is also reduced to an extent depending on the degree of overlap. The isolated "rod" curve at t(L) = 0.90 is quite accurately in the form of a probability integral. The data thus give a new experimental proof of the occurrence of two distinct but interlocking populations of visual effects, and experimentally justify the analytical procedures which have been used to separate them. 2. The changing form of the F - log I contour as a function of t(L), produced in man when the illuminated field is divided into parts by a shadow pattern, is normally found with the bird Taeniopygia castenotis (Gould), the zebra finch. The retina has elements of one general structural type (cones), and the F - log I contour is a simplex symmetrical probability integral. The eye of this bird has a large, complex, and darkly pigmented pecten, which casts a foliated shadow on the retina. The change in form of the F - log I curve occurs with t(L) above 0,50, and at t(L) = 0.90 is quite extreme. It is more pronounced than the one that is secured in the human data with the particular grid we have used, but there is no doubt that it could be mimicked completely by the use of other grids. The increase of flicker acuity due to the pecten shadow is considerable, when the dark spaces are brief relative to the light. The evidence thus confirms the suggestion (Menner) drawn from comparative natural history that the visual significance of the avian pecten might be to increase the sensory effect of small moving images. It is theoretically important that (as in the human experiment) this may be brought about by an actual decrease of effective retinal area illuminated. It is also significant theoretically that despite the presence of shadows of pecten or of grid, and of the sensory influences thus introduced, the probability integral formulation remains effective. PMID- 19873388 TI - FLICKER RESPONSE CONTOURS FOR THE SPARROW, AND THE THEORY OF THE AVIAN PECTEN. AB - The flicker contour for the house sparrow Passer domesticus is duplex, corresponding to the presence of both rods and cones in the retina. The presence of the pecten brings about changes in the "cone" part of the contour when the light-time in the flash cycle is varied. These changes are of the same sort as those we have already described for the visually simplex zebra finch, and for man provided with an artificial "pecten shadow." The changes are such as to greatly enhance flicker acuity for small dark-times (moving stripe technique). The form of the scotopic part of the duplex contour (also as in the case with man) gives no evidence that rod excitation is specifically influenced by the presence of the pecten. The changing integration of "rod" and "cone" effects as the light-time fraction is altered provides another means of testing the theory used for the analytical separation of the two components of the duplex flicker contour. PMID- 19873389 TI - THE EFFECT OF CARBON DIOXIDE TENSION ON THE METABOLISM OF CEREBRAL CORTEX AND MEDULLA OBLONGATA. AB - Manometric measurements were made of oxygen uptake (Q(O(O2) )) and aerobic lactic acid output (Q(G)) by slices of cerebral cortex and medulla oblongata of the cat in the presence of mixtures of 1, 5, and 20 volumes per cent of carbon dioxide in oxygen. The concentrations of NaHCO(3) and NaCl in the medium were varied to maintain constant pH and sodium ion concentrations. The calcium ion concentration was 0.0002 M. At pH 7.5 under these conditions, an increase in carbon dioxide from 1 per cent to 5 per cent doubled the Q(G) of both tissues but did not alter Q(O(O2) ); an increase from 5 per cent to 20 per cent carbon dioxide had no further effect on Q(G) in either tissue or Q(O(O2) ) of cortex, but did depress the Q(O(O2) ) of medulla. At pH 8.1, an increase in carbon dioxide from 1 per cent to 5 per cent raised the Q(O(O2) ) and Q(G) of cortex by about 60 per cent. Measurements at low oxygen tension carried out previously in phosphate medium were repeated in bicarbonate medium to obtain data for the combined output of lactic acid and carbon dioxide (Q(A)). When the oxygen in the gas phase was decreased from 95 to 3 volumes per cent, the lactic acid output as measured colorimetrically increased by 114 mg./gm. in cortex and by 8 mg./gm. in medulla; Q(A) increased from 12.3 to 13.5 in cortex and decreased from 5.1 to 3.8 in medulla. PMID- 19873390 TI - I. THE RELATION BETWEEN ATTACHMENT TO THE SUBSTRATUM AND INGESTION BY AMEBA IN STRYCHNINE SULFATE SOLUTION AND CONDITIONED MEDIA : II. BIOLOGICAL ASSAY OF CONDITIONED MEDIA. AB - 1. Strychnine sulfate 0.000069 M decreased percentage attachment to the substratum by Amoeba proteus in 0.0029 M NaCl from 77.3 to 1.3, in 0.0029 M KCl from 40.8 to 2.5, in 0.002 M CaCl(2) from 73.3 to 68.0, in 0.002 M MgCl(2) from 85.5 to 83.3. 2. Frequency of ingestion of chilomonads by Amoeba proteus is increased by adding strychnine sulfate to solutions of NaCl, KCl, or CaCl(2). Frequency of ingestion is increased in NaCl solution from 1.3 to 2.3, in KCl from 0.75 to 2.25, and in CaCl(2) from 1.1 to 1.9 chilomonads per minute. Ingestion is not significantly increased by the addition of strychnine to MgCl(2) solution. 3. Frequency of ingestion of food by Amoeba proteus is not closely correlated with attachment to the substratum in NaCl and KCl solutions to which strychnine sulfate is added. 4. Chilomonads adhere to the plasmalemma of Amoeba proteus in solutions of NaCl, KCl, or CaCl(2) containing strychnine, but in MgCl(2) plus strychnine only a few adhere to it. Strychnine appears to make the surface of the amebae and chilomonads sticky in the former but not in the latter. Frequency of ingestion is apparently correlated with adherence of chilomonads to the plasmalemma. 5. Attachment to the substratum and ingestion by Pelomyxa carolinensis is increased by dead Chilomonas, Colpidium, and Paramecium in aqueous solutions, by materials obtained from paramecia by alcoholic-ether extraction, and by solutions in which these organisms have lived. 6. Attachment to the substratum by Pelomyxa carolinensis is not closely correlated with kind or concentration of inorganic salts used in this study. 7. Materials were found in extracts of paramecia which had certain characteristics in common with choline esters. There is no reason to doubt that under certain conditions materials are present in aqueous and alcoholic extracts which are pharmacologically similar to choline and acetylcholine. 8. Aqueous suspensions of paramecia when subcutaneously injected into young mice for 21 days inhibit the gonadotropic luteinizing hormone of the pituitary. Ovaries from injected mice showed no corpora lutea, and the seminal vesicles from injected males were smaller and contained less fluid than those of the controls. PMID- 19873391 TI - STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS : III. CHANGES IN THESE PROPERTIES OF MYOSIN SOLUTIONS IN RELATION TO ADENOSINETRIPHOSPHATE AND MUSCULAR CONTRACTION. AB - 1. An investigation of the physicochemical properties of myosin has been carried out. Prepared under standard conditions, the ratio of flow-birefringence to protein concentration is uniform. The effect of electrolytes, pH, and urea on the flow-birefringence and viscosity (relative and anomalous) of myosin has been examined. 2. Decrease or abolition of flow-birefringence does not necessarily imply far reaching denaturation, since such effects can be reversed by a variety of means. 3. When a myosin solution is treated with adenosinetriphosphate, its flow-birefringence is decreased (average 48 per cent), its anomalous viscosity is retained, and its relative viscosity is decreased (average 14 per cent). The full effect of adenosinetriphosphate is obtained at 0.004 M; a molarity very much less than that of other substances which decrease the flow-birefringence of myosin. 4. The changes in the physicochemical properties of myosin brought about by adenosinetriphosphate are spontaneously reversible, and are connected with the enzymatic action of the protein as adenosinetriphosphatase. 5. Effects similar to those of adenosinetriphosphate on the physicochemical properties of purified myosin have been obtained so far only with inosinetriphosphate. 6. Inorganic phosphate is split off by myosin from inosinetriphosphate as well as from adenosinetriphosphate. Inorganic triphosphate is split by 1 to 2 per cent solution of three times precipitated myosin. 7. Adenosinediphosphate and inorganic triphosphate act as competitive inhibitors with adenosinetriphosphate, blocking the fall of flow-birefringence. 8. The implications of the results, and the conception of active enzymic groups attached to proteins participating in cell structure, whether contractile or non-contractile, are discussed in relation to present views on muscle physiology and other biological problems. PMID- 19873392 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : XI. ON FLICKER WITH SUBDIVIDED FIELDS. AB - Flicker contours for a square image of 3 degrees visual angle, centered 6 degrees on the temporal side of the fovea, the light sectored at a focus, are strikingly modified if the same illuminated area is arranged in four squares separated by a narrow opaque cross. The "cone" curves are made much steeper, and their abscissae of inflection (tau' are at higher intensities; F(max.) is not greatly changed, but alters less with change of light-time fraction in the flash cycle (t(L)). This modification is accompanied by a great enlargement of the scotopic segment of the duplex curves, consistent with the theory of the integrative relations of neural effects in the two groups of units involved. The changes are not consistent with the view that flicker end-points are determined by the activation of retinal cells with a fixed spatial distribution of invariable thresholds. At t(L) = 0.50 the 3 degrees subdivided area gives very nearly the same contour as does a square 6 degrees x 6 degrees , with the same total perimeter of light-dark separation; the "edge effect" thus suggested is complicated by differences in the dependence of F(max.) and tau' upon t(L). When an image pattern is produced by a grid of light bars separated by equally broad opaque spaces (10 degrees x 10 degrees over-all, centered at the fovea), the photopic flicker contours are made very steep and their midpoints are situated at quite low intensities, while the "rod" contribution tends to be more completely fused with the "cone" than is found for fields not subdivided. However, instead of a progressive increase of tau' with t(L) the curves for t(L) = 0.75 and 0.90 lie respectively below that for t(L) = 0.25 and 0.50 for a field of four broader stripes (1.43 degrees ) and both are below t(L) = 0.25 for a field of seven narrower stripes (0.77 degrees ). These latter changes are discussed in terms of the participation of subsidiary phenomena involving so called "gamma movement." It is pointed out that since in these data sigma(1)/I(m) is for each set of conditions a statistically constant quantity with a characteristic breadth of scatter sigma(sigma), it is possible to calculate a "coefficient of internal correlation" r which is a function of the conditions (as: image area, location, wave length of light, structure of image, light-time fraction) and which describes a property of any entire contour. The changes in r, as a function of the conditions of flicker excitation, reflect changes in the neural organization responsible for the liminal discrimination of flicker. It is shown that as consequence of simple changes in the image field, three parameters, as of the probability summation, are required for the description of a simplex flicker contour-since each of these is independently modifiable as to its magnitude and in its dependence on the light-time fraction. Subdivision of the image, with light sectored at a focus, produces in part only the changes in the flicker contour which we have earlier labelled the "pecten effect." In the latter, with light not sectored at a focus but with bar images moving across a field with inclined fixed opaque bars, the "cone" slope (dF/d log I) is sharply increased for t(L) > 0.50, but not below t(L) = 0.50, and the value of tau' is much less than it "should be." Consequently, the change in contrast brought about by the moving contact of light/dark borders is the significant factor in the "pecten effect," not simply pulsatile interruption of the light. PMID- 19873393 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : VIII. QUANTITATIVE STUDIES CONCERNING THE ACIDIC PROPERTIES OF COLLODION AND THEIR CORRELATION WITH MEMBRANE STRUCTURE AND ACTIVITY. AB - 1. The electrochemical behavior ("activity") of collodion membranes depends upon acidic, dissociable groups located in the interstices of the membranes. The active groups can be determined by base exchange measurements. High base exchange capacity is always found with preparations of great "electrochemical activity;" medium and low base exchange capacities occur with electrochemically active as well as with inactive preparations. The observed base exchange capacity is determined by two factors: the inherent acidity of the collodion (its mean equivalent weight) and the submicroscopic micellar structure of the collodion. A comparison of the base exchange capacity of various collodion preparations and their inherent acidities therefore allows certain conclusions to be drawn concerning the relative availability of the micellar surfaces in the different preparations. 2. The inherent acidity of various collodion preparations, their "acid number," was determined by electrometric titration. Collodion in the acidic state, i.e. after exchange of all other cations for H(+) ions, was titrated in an organic solvent mixture with alcoholic KOH using a quinhydrone electrode. Details of the experimental procedure are given in the paper. The acid numbers, expressed in milliliters of 0.01 N KOH per gram dry collodion, vary from 1.0 for a highly purified collodion preparation of very low electrochemical activity to 3.3 for a highly oxidized sample of very high activity. Acid numbers of about 1.5 (corresponding to an equivalent weight of about 67,000) are found both with inactive commercial and with fairly active oxidized preparations. The base exchange capacity of the same preparations in the fibrous state as measured after 48 hours of exchange time varies from 0.0013 ml. 0.01 N NaOH per gm. dry collodion for the most inactive preparation up to 0.26 ml. 0.01 N NaOH per gm. for the most active preparation. Thus the acid numbers over the whole range investigated differ only in the ratio of 1:3.3, whereas the base exchange values differ in the range of 1:200. 3. In the inactive preparation only one in 770 acid groups is available for base exchange, in the most active collodion one group in 13; values between these extremes are found with commercial and alcohol purified oxidized preparations. 4. The high base exchange capacity of the electrochemically active preparations is not so much due to their higher acid number as to their more open structure. This difference in structure is ascribed to the presence of a small fraction of low molecular weight material which inhibits normal formation and arrangement of the micelles. 5. Short time base exchange experiments with fibrous collodion indicate that the number of acid groups available for the typical electrochemical membrane functions may be estimated to be about 50 to 1000 times less numerous than those found in the 48 hour base exchange experiments. It is estimated that in membranes prepared even from the most active collodion not more than one in 500 acid groups may be available for the typical membrane functions; with the less active preparations this ratio is estimated to be as high as one in 1,000,000 or more. PMID- 19873394 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : IX. WATER UPTAKE AND SWELLING OF COLLODION MEMBRANES IN AQUEOUS SOLUTIONS OF ORGANIC ELECTROLYTES AND NON-ELECTROLYTES. AB - 1. Dried collodion membranes are known to swell in water and to the same limited extent also in solutions of strong inorganic electrolytes (Carr and Sollner). The present investigation shows that in solutions of organic electrolytes and non electrolytes, the swelling of dried collodion membranes is not as uniform, but depends on the nature of the solute. 2. The solutions of typically "hydrophilic" substances, e.g., glycerine, glucose, and citric acid, swell collodion membranes only to the same extent as water and solutions of strong electrolytes. In solutions of typically carbophilic substances (e.g., butyric acid, valeric acid, isobutyl alcohol, valeramide, phenol, and m-nitrophenol) the swelling of the membranes is much stronger than in water, according to the concentration used. For the brand of collodion used the swelling in 0.5 M solution was in some cases as high as 26 per cent of the original volume, as compared to 6 to 7 per cent in water. Therefore, in these solutions the "water-wetted dried" collodion membrane is not rigid, inert, and non-swelling, but behaves as a swelling membrane. 3. The solutes which cause an increased swelling of the membranes are accumulated in the latter, the degree of accumulation being markedly parallel with the degree of their specific swelling action. 4. The anomalously high permeabilities of certain carbophilic organic solutes reported by Michaelis, Collander, and Hober find an explanation in the specific interaction of these substances with collodion. 5. The use of the collodion membrane as a model of the ideal porous membrane is restricted to those instances in which no specific interaction occurs between the solute and the collodion. PMID- 19873395 TI - THE EFFECT OF URETHANE ON THE CONSUMPTION OF OXYGEN AND THE RATE OF CELL DIVISION IN THE CILIATE TETRAHYMENA GELEII. AB - 1. The inhibition of oxygen consumption produced by a series of concentrations of ethyl carbamate has been measured in the protozoan Tetrahymena geleii. 2. The relation found between the narcotic concentration and its effect on respiration leads to the conclusion that urethane has two distinct modes of action in this cell. The respiratory data can be accurately predicted by assuming that the inhibitor acts on two independent parallel respiratory systems. 3. Complete suppression of cell division in this organism is brought about by approximately 0.1 M urethane. 4. Urethane concentrations up to 0.1 M affect primarily only one of the two postulated respiratory systems. The mechanism of the narcosis of cell division in this organism by urethane thus appears to be inhibition of this "activity" system. PMID- 19873396 TI - THE EFFECTS OF URETHANE AND CHLORAL HYDRATE ON OXYGEN CONSUMPTION AND CELL DIVISION IN THE EGG OF THE SEA URCHIN, ARBACIA PUNCTULATA. AB - The effects of a series of concentrations of the narcotics, ethyl carbamate and chloral hydrate, have been determined on the consumption of oxygen by fertilized and unfertilized eggs of the sea urchin Arbacia punctulata. In the fertilized eggs the effects of the two inhibitors on cell division were also examined. The following observations were made: 1. Assuming that the narcotic acts upon a single catalyst in the unfertilized egg the degree to which the consumption of oxygen is inhibited in this resting cell can be related to the narcotic concentration by an expression derived from the law of mass action. 2. To account for the relation between the concentration of the narcotic and its effect on respiration in the fertilized eggs, it is necessary to conclude that in them the narcotic acts on two parallel respiratory systems. The experimental data can be quantitatively predicted (1) if the reaction of the narcotic on the two systems is governed by the law of mass action and (2) if 40 per cent of the oxygen consumption is mediated by one system, the "activity" system, and the remainder by the other, the "resting" or "basal" system. 3. The mass law constants applying to the resting system in the fertilized egg are similar to those for the single system functioning in the unfertilized egg so that these two respiratory systems are probably identical. 4. The concentrations of the narcotics just sufficient to abolish cell division affect primarily the activity system, the existence of which was inferred from the respiratory experiments. It is concluded that normal cell division requires specifically the normal function of the activity system, that in fact the energy for cell division is made available through that system. PMID- 19873397 TI - THE KINETICS OF IN VIVO HEMOLYTIC SYSTEMS. AB - This paper is concerned with a variety of questions which bear on the occurrence of hemolysis in vivo, and with the possibility of regarding the contents of the blood stream as a hemolytic system in which a steady state is maintained by the production of new red cells to replace those which are destroyed. The material which is dealt with includes the following. 1. Mixtures of Lysins, Accelerators, and Inhibitors.-The effects of individual accelerators and inhibitors in mixtures, like the effects of individual lysins, are roughly additive in simple systems, the acceleration or inhibition produced by the individual substances being most conveniently measured in terms of R-values. 2. Normal Intravascular Lysins.-These probably play only a small part in red cell destruction unless their concentration rises to unusual levels, or unless their effects are enhanced by accelerators, or by the reduction of the concentration of normal inhibitors. The three normal in vivo hemolytic processes for which there is substantial evidence involve (a) the action of the bile salts and of the soaps derived from chyle, (b) the action of the spleen, and (c) the action of hemolytic substances derived from tissues. The recent observations of Maegraith, Findlay, and Martin on the presence of widely distributed tissue lysins are confirmed except for their conclusion that these lysins are species-specific. Species-specific tissue lysins, if present, are not the only lysins derivable from tissues by simple immersion in saline, for non-species-specific lytic substances can also be obtained, and seem to be similar to the "lysolecithin" which some regard as responsible for the action of the spleen on red cell fragility and shape. 3. Plasma Inhibitors.-About 30 per cent of the total inhibitory effect of plasma for saponin hemolysis is due to the contained cholesterol, while 25 per cent at most is due to the plasma proteins, particularly globulins. The remaining 45 per cent is probably accounted for by enhancing effects among the inhibitors; e.g., the enhancing effect of lecithin on the cholesterol inhibition. The mechanism of the inhibition is still incompletely understood; probably reactions between inhibitor and lysin and reactions between inhibitor and components of the red cell surface are both involved, and it is important to observe that the inhibitory effect of plasma or of a plasma constituent may be greater in systems containing one lysin than in systems containing another. No evidence for diffusible inhibitory substances in plasma has been found, and the variations observed in the inhibitory power of human plasma seem to be related to the combined concentrations of cholesterol, protein, and probably lecithin, rather than to the cholesterol content alone. For this reason the inhibitory power tends to be low under conditions of poor nutrition. 4. The Steady State and the Kinetics of Hemolysis In Vivo.-On the assumption that the steady state is the result of a balance between a process which produces red cells and a process which destroys them, equations have been developed for the way in which cells of different resistances are affected when the rate of destruction changes. A method for analyzing experimental curves is described and illustrated. In general, this part of the paper relates the level of the red cell count in the animal to the intensity of the hemolytic processes taking place in vivo, and does not lend itself to detailed abstraction. PMID- 19873398 TI - THEORY AND MEASUREMENT OF VISUAL MECHANISMS : XII. ON VISUAL DUPLEXITY. AB - Flicker contours from vertebrates (fishes to man) show that the slope parameter sigma'(log I) in the efficiently descriptive probability summation 100 F/F(max.) = integral(-inf;) (log I)e(-(log I/I(i))(-(log I/I(i))2)/2(sigma')(/2(sigma')2) ) .d log I is distributed bimodally (simple fields, "white" light), from 0.60 to 2.3, with well defined peaks at 0.80 and 1.75. This parameter is independent of F(max.), log I(i), temperature, light-time fraction, and in general not greatly influenced by lambda. "Rod" components of known visually duplex contours, without exception, and some "cone" contours, are in the first group; an equal number of "cone" curves are in the second group, together with one simplex "rod" contour; purely cone contours are in each group, as well as cone segments of duplex curves. No firm zoological grouping of the "cone" curves can be made, on present evidence,-although the 5 fishes used give high-slope curves, 2 amphibians low slopes, reptiles (5) either high or low, birds (2) and anthropoids (2) low-slope "cone" curves. By subdivision of the visual image and by change of wave-length, under certain conditions, in man, and by use of the "pecten effect" in birds (and man), cone contours of the low-slope class can be transformed into curves of the high-slope group. These procedures do not fundamentally change the "rod" slopes. Consequently, although under simple conditions they are specifically determined, the forms of the F - log I contour cannot be used as diagnostic for rod or cone functioning. It is reinforced, by new data on Anolis (lizard) and Trionyx (turtle), that an obviously duplex retina is specifically correlated with a duplex performance contour, a simplex retina with a simplex one. But no support is given to the view that the shapes of these curves are diagnostic of differences in rod or cone fundamental excitabilities, or that they describe properties of these units. In visual duplexity we have to do simply with the fact that two groups of neural effects are available; it is with their properties that we deal in measurements of duplex visual excitability. PMID- 19873399 TI - THE MECHANISM OF ENZYME-INHIBITOR-SUBSTRATE REACTIONS : ILLUSTRATED BY THE CHOLINESTERASE-PHYSOSTIGMINE-ACETYLCHOLINE SYSTEM. AB - The mechanism of enzyme-inhibitor-substrate reactions has been analyzed from a theoretical standpoint and illustrated by data from the system cholinesterase physostigmine-acetylcholine. This treatment is by no means limited to a single system but should be generally applicable to others of similar type. Competitive enzyme-inhibitor-substrate systems show the same characteristic "zones of behavior" already demonstrated for non-competitive systems by Straus and Goldstein. These zones, three in number, determine the mathematical function which relates activity of an enzyme to concentration of an added substrate or inhibitor or both. The effects of suboptimal substrate concentration in such systems have been considered, and the errors arising from various common simplifications of the descriptive equations have been pointed out. The zone behavior phenomenon has been shown to be useful in determining the number of molecules of substrate or inhibitor combining reversibly with a single enzyme center. The kinetics of competitive inhibition, dilution effect, combination of inhibitor or substrate with enzyme, and destruction of inhibitor or substrate by enzyme have been analyzed and experimentally verified, and absolute velocity constants have been determined. Theoretical conclusions have been discussed from the standpoint of their physiological significance. Specifically, it has been shown that: 1. The inhibition of cholinesterase by physostigmine is competitive. A single molecule of physostigmine or acetylcholine combines with one center of cholinesterase-n = 1; and the mechanism n = 2 has been. excluded. Numerical values of the constants for this system are as follows: K(I) = 3.11 x 10(-8)k(1) (combination) = 8.3 x 10(5)k(2) (dissociation) = 0.026 K(S) = 1.25 x 10(-3)k(3) (combination) = 260 k(4) (dissociation) = 0.32 2. No definitive value can be assigned to E, the molar concentration of enzyme centers, but in 4.54 per cent dog serum, E < 1.8 x 10(-8) (E(I)' < 0.58). The system therefore operates in (or nearly in) zone A at this concentration. 3. Competitive displacement of inhibitor by substrate and vice versa introduces considerable error in the usual 20 minute determination of the activity of an inhibited enzyme, unless properly corrected for. 4. Dissociation of the enzyme-inhibitor complex on dilution proceeds moderately slowly so that the full corrections for dilution cannot be applied unless time has been allowed for full dissociation. 5. Combination of physostigmine with cholinesterase is slow at all but large concentrations of inhibitor. 6. The destruction of physostigmine or acetylcholine by cholinesterase follows the predicted curve; k(D) for the destruction of physostigmine is found to be > 0.00182; k(D) for acetylcholine destruction is > 3500. There is no reason to assume inhibition of destruction by excess substrate or inhibitor. 7. The common assumption that enzymatic activity follows (or nearly follows) a monomolecular course is true only under limited conditions, which have been here defined. It is not valid, as a rule, for the enzymatic destruction of an inhibitor (e.g., physostigmine) and its application to such a case may lead to erroneous conclusions about the reaction mechanism. PMID- 19873400 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : X. AN EXPERIMENTAL TEST OF SOME ASPECTS OF THE TEORELL AND MEYER-SIEVERS THEORIES OF ELECTRICAL MEMBRANE BEHAVIOR. AB - 1. The Teorell, Meyer-Sievers theory characterizes the electrochemical behavior of membranes by their selectivity constant "A(p)" which is derived conventionally from concentration potential measurements at various concentration levels. The selectivity constant may, however, be derived also from entirely independent, different experimental data, namely base exchange studies. The constants arrived at in this second way are designated as "A(b)." The selectivity constants derived by these two methods must be in reasonable, at least semiquantitative agreement if the basic assumptions of the theory are correct. 2. The selectivity constants A(p) and A(b) were determined for eleven different sets of membranes of different electrochemical activity and of different (8.2 to 80 volume per cent) water content. 3. The potentiometric selectivity constants A(p) are in most cases several orders of magnitude greater than the corresponding A(b) values. With membranes of great porosity and high electrochemical activity the A(b) values approach at least in order of magnitude the A(p) values. 4. It is concluded that the unexpectedly large discrepancy between the A(p) and A(b) values is due to some inherent weakness of the Teorell, Meyer-Sievers theory, most likely to its neglect of any structural factors. PMID- 19873401 TI - STUDIES OF THE INNER AND OUTER PROTOPLASMIC SURFACES OF LARGE PLANT CELLS : II. MECHANICAL PROPERTIES OF THE VACUOLAR SURFACE. AB - The vacuolar surface of Nitella is covered with a non-aqueous film too thin to be visible as a separate membrane. The motion of the protoplasm may subject this film to a good deal of mechanical disturbance. Apparently this does not rupture the film for no dye escapes into the protoplasm as the result of such disturbance when the vacuolar sap is deeply stained with neutral red or brilliant cresyl blue. When the deeply stained central vacuole breaks up into several smaller vacuoles, leaving the outer protoplasmic surface in its normal position, there is no evidence of the escape of dye into the protoplasm through the film surrounding the vacuole. PMID- 19873402 TI - DIFFERING RATES OF DEATH AT INNER AND OUTER SURFACES OF THE PROTOPLASM : I. EFFECTS OF FORMALDEHYDE ON NITELLA. AB - When protoplasm dies it becomes completely and irreversibly permeable and this may be used as a criterion of death. On this basis we may say that when 0.2 M formaldehyde plus 0.001 M NaCl is applied to Nitella death arrives sooner at the inner protoplasmic surface than at the outer. If, however, we apply 0.17 M formaldehyde plus 0.01 M KCl death arrives sooner at the outer protoplasmic surface. The difference appears to be due largely to the conditions at the two surfaces. With 0.2 M formaldehyde plus 0.001 M NaCl the inner surface is subject to a greater electrical pressure than the outer and is in contact with a higher concentration of KCl. In the other case these conditions are more nearly equal so that the layer first reached by the reagent is the first to become permeable. The outer protoplasmic surface has the ability to distinguish electrically between K(+) and Na(+) (potassium effect). Under the influence of formaldehyde this ability is lost. This is chiefly due to a falling off in the partition coefficient of KCl in the outer protoplasmic surface. At about the same time the inner protoplasmic surface becomes completely permeable. But the outer protoplasmic surface retains its ability to distinguish electrically between different concentrations of the same salt, showing that it has not become completely permeable. After the potential has disappeared the turgidity (hydrostatic pressure inside the cell) persists for some time, probably because the outer protoplasmic surface has not become completely permeable. PMID- 19873403 TI - DIFFERING RATES OF DEATH AT INNER AND OUTER SURFACES OF THE PROTOPLASM : II. NEGATIVE POTENTIAL IN NITELLA CAUSED BY FORMALDEHYDE. AB - A previous paper showed that when the inner protoplasmic surface has lost its potential under the influence of formaldehyde the outer surface can still respond to changes in the concentration of electrolytes. The present paper indicates that after the inner surface has lost its potential there may be a sudden development of negative potential at the outer surface due to substances coming out of the sap and combining with formaldehyde. PMID- 19873404 TI - ACTION OF POTASSIUM AND NARCOTICS ON RECTIFICATION IN NERVE AND MUSCLE. AB - Electrical rectification was demonstrated in whole sartorius muscle and sciatic nerve of Rana pipiens and also in the single giant nerve fiber of the northern squid, Ommastrephes illecibrossus. It is probably a property of the plasma membrane. Rectification decreases reversibly under the influence of increased concentrations of the potassium ion and with chloroform, veratrine sulfate and isoamyl carbamate. No effect was found with lack of calcium, excess calcium, or barium chloride. Decrease in rectification is invariably accompanied by simultaneous decrease in resting potential. A proposed explanation of the mechanism of rectification is discussed. Rectification in a living membrane, viz. a change in resistance with change in direction of current flow, may possibly be explained in terms of a change in the concentration of potassium ions in the membrane. PMID- 19873405 TI - THE PENETRATION OF AMMONIA INTO FROG MUSCLE. AB - 1. A study was made of the electrolyte changes which occur when frog muscles are immersed in a Ringer solution with 1/5 of the Na replaced by NH(4)Cl. Analyses were made in the solution and in the muscles for K and NH(3), and the muscles were also analyzed for Cl, HCO(3), and Na. Control muscles were immersed in normal Ringer's solution and similarly analyzed. 2. The amount of ammonia taken up was about equal to the K and Na lost. There was also a small increase in chloride content. The bicarbonate content was the same in both experimental and control muscles, indicating no change in the muscle pH due to the NH(3) which penetrated. An increased loss of K due to the penetration of NH(3) was also demonstrated by the use of radioactive K. 3. After 5 hours, the concentration of ammonia per gram of muscle is about the same as the concentration in the solution. After 4 or 5 days, the concentration in the muscle is about 1.5 times that in the solution. The inside to outside NH(3) ratio is about equal to the corresponding H ion ratio, but is much less than the K ratio. 4. The rate of penetration of the NH(3) is increased by a rise of temperature, by stirring the solution, and by decrease in the concentration of Na, K, Ca, or Mg in the solution; it is decreased by increasing the size of the muscles or by killing them with chloroform or boiling. 5. Liver, smooth muscle, skin, and kidney, in a few experiments, behaved much like muscle except that there was a formation of urea in the case of liver. 6. The injection of NH(4)Cl into anesthetized cats causes an increase in the level of K in the blood plasma. PMID- 19873406 TI - THE RHEOLOGY OF THE BLOOD. III. AB - The authors have confirmed the fact that blood serum and plasma behave rheologically like a true viscous liquid. It is true for whole blood only to a first approximation, but with this reservation they have studied the available data and extended the equation of Bingham and Durham to cover protein solutions of various concentrations and at various temperatures as well as mixtures of proteins and corpuscles present in whole blood. If Phi is the fluidity of whole blood, Phi(1) is the fluidity of water and DeltaPhi = Phi - Phi(1), then DeltaPhi = beta(1)b(1) + beta(2)b(2) + beta(3)b(3) + ... where beta(1), beta(2), beta(3), etc., are constants for the fluidity lowering of the salts, albumin, globulin, fibrinogen, and the corpuscles, etc., present in the whole blood. The conclusions from the data referred to are intended to buttress this simple equation (6). PMID- 19873407 TI - CULTURE CONDITIONS AND THE DEVELOPMENT OF THE PHOTOSYNTHETIC MECHANISM : II. AN APPARATUS FOR THE CONTINUOUS CULTURE OF CHLORELLA. AB - 1. An apparatus has been developed which maintains a constant density of population of Chlorella by automatic dilution of the growing culture with fresh medium. 2. Cells harvested from the apparatus in daily samples are highly uniform in rate of growth and rate of photosynthesis measured under arbitrarily chosen conditions. PMID- 19873408 TI - A SELECTIVE LETHAL EFFECT OF PENICILLIN ON SARCOMA CELLS GROWING WITH NORMAL TISSUE IN ROLLER TUBE CULTURES. AB - An agent present in pharmaceutical Squibb and in Reichel penicillin preparations was found to exert a selective lethal effect upon rat and mouse sarcoma cells growing with normal cells in tissue cultures. PMID- 19873409 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : XI. THE PREPARATION AND PROPERTIES OF "MEGAPERMSELECTIVE" COLLODION MEMBRANES COMBINING EXTREME IONIC SELECTIVITY WITH HIGH PERMEABILITY. AB - 1. The electronegative membranes described in the literature which show a high degree of ionic selectivity (permitting cations to pass and restricting the anions) have serious shortcomings: their absolute permeability is extremely low, much too small for convenient experimentation; their ionic selectivity in most cases is not as perfect as would be desirable, and is moreover adversely affected by prolonged contact with electrolyte solutions. 2. A method has been worked out to prepare membranes substantially free from these defects. Porous collodion membranes were cast on the outside of rotating tubes and then oxidized with 1 M NaOH. By allowing the oxidized porous membranes to dry in air on the tubes membranes of desirable properties are obtained. These membranes are smooth, have a well defined shape, and allow considerable handling without breaking. 3. This new type membrane when tested for ionic selectivity by the measurement of the "characteristic concentration potential," consistently gives potentials of 54 to 55 mv., the maximum thermodynamically possible value (at 25 degrees C.) being 55.1 mv. This high degree of ionic selectivity is not lost on prolonged contact with water, and is only very slowly affected by electrolyte solutions. 4. The absolute permeability of the new type membranes can be varied over a very wide range by changing the time of oxidation. Under optimum conditions membranes can be obtained with a resistance in 0.1 N KCl solution of only 0.5 ohms per 50 cm.(2) membrane area. The absolute rate of cation exchange through these membranes between solutions of different uni-univalent electrolytes is very high, in one case, e.g. 0.9 m.eq. cations per 4 hours, the anion leak being 0.02 m.eq. Thus, the absolute permeability of the new type membranes is two to four orders of magnitude greater than the permeability of the dried collodion membranes and the oxidized ("activated") dried collodion membranes used heretofore. Because of the characteristic properties of the new type membranes the term "megapermselective" (or "permselective") collodion membranes is proposed for them. PMID- 19873410 TI - THE RHEOLOGY OF THE BLOOD : IV. THE FLUIDITY OF WHOLE BLOOD AT 37 degrees C. AB - In the preceding paper (1b) a formula was developed for the lowering of the fluidity of a medium by a mixture of proteins, given the volume concentration of each and its fluidity-lowering constant. Whole blood is now shown to follow an essentially similar formula, except that the hemoglobin content is taken from the literature as the best available measure of the volume of the blood cells Delta Phi = 0.24H, assuming the fluidity of the medium to be 53 rhes. Age, sex, diet, barometric pressure affect the hemoglobin content of the blood, but the formula may apply to any healthy human blood to about 3 per cent. The shape, number, and size of the blood cells, if known, might help to explain discrepancies as well as the state of oxidation of the blood. In disease the discrepancy becomes much greater, suggesting the possible use of rheology in diagnosis. PMID- 19873411 TI - X-RAY DIFFRACTION STUDIES ON FROG MUSCLES. AB - 1. X-ray diffraction studies of sartorius muscles of Rana pipiens were made in a new x-ray diffraction camera which permits exposures of 3 to 6 minutes. The object-film distance can be varied from 20 to 80 mm; the muscle inside the camera can be electrically stimulated while contracting isotonically or isometrically, and can be observed by a special device. After exposures up to 30 minutes (approximately 40,830 r) muscles are still alive and responsive. 2. Contrary to the x-ray diffraction pattern of powdered dry muscle, which pattern consists of two rings corresponding to spacings of 4.46 A.u. and 9.66 A.u., both moist and dried whole sartorius muscle show signs of orientation in both rings, consisting of two equatorial streaks (wet) or points (dry) and meridional sickles. The moist muscle shows in addition a diffuse water ring. The spacings corresponding to the orientation points and elliptical structure show only slight differences in moist and dried samples. Through statistical computations based on two different series consisting of thirteen moist and twenty-eight dried samples, and nine muscles before and after drying, it was shown that only the divergence in the smaller spacing has some real significance, which indicates that most water of the moist muscle is bound intermolecularly. Upon resoaking of dried muscle the x-ray diffraction pattern of the moist muscle is restored. 3. Stretching of muscle by weights below the breaking point produces an additional well defined diffraction line, corresponding to a spacing of 4.32 A.u. A similar diffraction line can be produced in frog tendon upon stretching. 4. The influence of heat on the x-ray diffraction pattern of muscle depends upon the maximum temperature and the length of action; 5 minutes at 50 degrees C. markedly reduces the orientation of the sample; 5 minutes' immersion in boiling Ringer's solution destroys the orientation and produces a ring corresponding to a spacing of 5.3 to 5.5 A.u. in the moist and sharpening of the backbone reflection in the dried specimen. 5. Ultraviolet light brings forth changes in the x-ray diffraction pattern varying with the intensity of the irradiation. Ultimately a disappearance of the equatorial points and of the outside sickles is achieved while the elliptical shape of the outside ring and its diffuseness persist. In addition two salt rings characteristic of NaCl indicate that the irradiated muscles have become permeable to the surrounding medium (Ringer's solution). 6. Both faradic and single shock electrical stimulation were tried on muscles. If shortening of the muscle is prevented either by sufficient weight or by tying the muscle in a frame, no changes in the x-ray diffraction pattern occur; if the muscle is allowed to shorten without weights or by using insufficient weights, then the orientation either disappears completely or partially. When the muscle is stretched while contracted by electrical stimulation the orientation of the x-ray diffraction pattern reappears. 7. A number of salts with uni- and bivalent ions in concentrations corresponding osmotically to 0.73 per cent NaCl and 10 per cent NH(4)Cl were studied in their effects upon the x-ray diffraction of muscles. Of the salts with univalent ions in the lower concentration only KCl causes a marked decrease of orientation and an increase in the permeability of the fiber membranes. Similar effects on the orientation seem to be produced by CaCl(2) while MgCl(2) causes rather a more pronounced orientation. At hypertonic salt concentrations the orientation disappears completely and the corresponding salt rings become visible. Besides, NaCNS seems to have a specific effect on the outside ring and LiCl produces a ring at 21.3 A.u. and a splitting of the outside ring. 8. Strong mineral and lactic acids in concentrations up to 0.005 N have little if any influence upon the x-ray diffraction of muscles. A further increase in acidity to 0.01 N and above destroys the orientation completely, causes sharpening of the backbone reflection, and increased membrane permeability. These changes are irreversible upon neutralization. Also the effects of swelling upon the water ring of fresh muscle become manifest. Weak acids at higher concentrations show an effect similar to that of strong acids. 9. Rigor mortis produces a more or less complete loss of orientation. The muscles show signs of increased permeability. 10. Alkalies destroy the orientation of the x-ray diffraction pattern. The effective concentration is higher than the corresponding amount of acid. 11. Formaldehyde produces only minor changes in the x-ray diffraction patterns of muscles. 12. The effects of alcohol depend primarily upon the concentration applied. Low concentrations (5 per cent) seem to have a passing stimulating effect, at concentrations of 15 per cent, the anesthetizing effect becomes manifest in well defined orientation. The diameter of the water ring is reduced. If 95 per cent alcohol is allowed to act upon muscle for more than 12 minutes, then the orientation disappears completely and the backbone spacing becomes as sharp as in boiled muscle. 13. The effects of chloroform depend upon whether the muscle is allowed to contract or not. Only if the muscle is allowed to contract in chloroform-saturated Ringer's solution is the orientation lost and salt rings appear as well as a ring corresponding to a spacing of 22 A.u,, which has been observed in other changes in muscles. 14. In muscles allowed to shorten in a caffeine-Ringer's solution the orientation disappears, salt rings become visible as well as a decrease in size of the water ring; a new arc corresponding to a spacing of 4.18 A.u. was observed in one case. PMID- 19873412 TI - CHANGES IN THE APPARENT CYTOPLASMIC HYDROGEN ION CONCENTRATION OF AMEBA DUBIA ON INJECTION OF EGG ALBUMIN. AB - 1. Egg albumin when injected into an ameba or discharged into the solution about it raises the apparent pH of the cytoplasm of the ameba. 2. With time the cytoplasm returns to the original pH 6.9 if the nucleus is present. Amebae that have received repeated injections of albumin in some cases extrude their nuclei. In these cells the cytoplasm remains at the more alkaline pH induced by the albumin for at least 12 hours. 3. When a 2 per cent solution of albumin is introduced into a suspension of amebae there is a temporary marked rise in the rate at which CO(2) is given off with no corresponding rise in O(2) uptake. 4. The results observed can be explained if the albumin discharged onto the surface of the ameba rapidly enters the cell and there becomes distributed in a phase of the cytoplasm other than the one which contains the phenol red. PMID- 19873413 TI - THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR : XII. THE PREPARATION AND PROPERTIES OF "MEGAPERMSELECTIVE" PROTAMINE COLLODION MEMBRANES COMBINING HIGH IONIC SELECTIVITY WITH HIGH PERMEABILITY. AB - The technique of Abrams and Sollner for the preparation of electropositive dried protamine collodion membranes has been improved. Porous collodion membranes cast on the outside of rotating tubes are treated for 48 hours with a solution of 2 per cent protamine sulfate buffered at pH 11. After being washed thoroughly the membranes are dried in air for several hours, soaked in water for several hours, and removed from the tubes. Further drying in air but without support shrinks the membranes slightly. The resulting membranes are designated "permselective" or "megapermselective" protamine collodion membranes. These membranes regularly give characteristic concentration potentials of -52 to -53 mv. and (in 0.1 M KCl) resistance of 0.5 to 15 ohms per membrane of 50 cm.(2) area. This resistance is several orders of magnitude smaller than that of the conventional dyestuff- and alkaloid-impregnated positive membranes. The megapermselective protamine collodion membranes can be kept either dry or in water for prolonged periods without detectable deterioration. They are quite smooth, have a regular shape, and stand considerable handling without breakage. The megapermselective protamine collodion membranes are the electropositive analogues of the electronegative megapermselective collodion membranes described by Carr and Sollner. PMID- 19873414 TI - ELECTRIC TISSUE : RELATIONS BETWEEN THE STRUCTURE, ELECTRICAL CHARACTERISTICS, AND CHEMICAL PROCESSES OF ELECTRIC TISSUE. AB - In the main electric organs of the electric eel, the cross-sectional area, the thickness of the electroplaxes, and certain electrical characteristics of the tissue vary widely between the anterior and posterior ends. However, a transverse layer of the organs one electroplax thick has certain characteristics which are roughly uniform along the organs. These are its volume, its maximum voltage, its maximum current per unit area, and the resistance of unit area at the peak of the discharge. Measurements of the voltage developed by a segment of the organs across different external resistances at different instants during the discharge are all rather well described by representing the segment, with the adjacent non electric tissue, as a simple combination of E.M.F. and ohmic resistance. The internal resistance of the tissue varies during the discharge. Its E.M.F. appears to be practically constant, at least during the greater part of the discharge. Estimates made of the total electric energy show it about equal to the energy supplied by the decrease of phosphocreatine and the formation of lactic acid. PMID- 19873415 TI - MUSCULAR ACTIVITY AND BUBBLE FORMATION IN ANIMALS DECOMPRESSED TO SIMULATED ALTITUDES. AB - 1. Muscular activity during decompression causes bubble formation in the blood of intact bullfrogs. The amount of gas liberated depends on the degrees of muscular activity and supersaturation (as influenced by altitude). In decompressed dissected bullfrogs, bubbles appear in veins leading from active but not from inactive muscles. 2. Muscular activity during decompression similarly causes bubble formation in rats. Bubbles appear in veins coming from muscles, and often in the lymphatic system. Quiescent rats do not form bubbles. 3. Violent muscular activity before decompression favors bubble formation in bullfrogs during ensuing decompression, but it is less effective than exercise during decompression. The effect persists in large frogs for about an hour. 4. Pre-oxygenation for 2 to 4 hours before decompression reduces the incidence of bubble formation in decompressed bullfrogs. It thus has the same effect on bubble formation in bullfrogs as it does on the "bends" in man. The effect is presumably due to removal of nitrogen. 5. Possible mechanisms by which muscular activity causes bubble formation are discussed. The effects of mechanical agitation and of metabolic CO(2) are considered to be the dominant factors. PMID- 19873416 TI - CARBON DIOXIDE AS A FACILITATING AGENT IN THE INITIATION AND GROWTH OF BUBBLES IN ANIMALS DECOMPRESSED TO SIMULATED ALTITUDES. AB - 1. Rats killed in a variety of ways (broken neck, nembutal, anoxia, electrocution) may undergo extensive bubble formation when subsequently decompressed from atmospheric pressure to simulated altitudes of 50,000 feet. On autopsy at sea level, large numbers of bubbles are found throughout the vascular system in the majority of animals. These bubbles appear to originate in small vessels deep within muscular regions, later spreading widely in arterial and venous systems. Dead rabbits and frogs also bubble profusely on decompression. 2. Bubble formation in dead animals is attributed primarily to the accumulation of CO(2), derived from residual cellular respiration after death, and from anaerobic glycolysis with attendant decomposition of bicarbonates in blood and tissue fluids. If anaerobic glycolysis is inhibited by using sodium iodoacetate as a lethal agent, bubble formation is greatly reduced or lacking on subsequent decompression. 3. Experiments in vitro suggest that high concentrations of CO(2) favor bubble formation by reducing the degree of mechanical disturbance necessary. 4. Administration of CO(2) in high concentrations to living frogs lowers the minimum altitude (pressure equivalent) at which bubble formation occurs, with exercise, in untreated animals. Pre-treatment with CO(2) also reduces the degree of muscular activity necessary for bubbles to form in frogs at higher altitudes. 5. Analyses have been made of the gas content of bubbles taken directly from the large veins of decompressed frogs and rats. In living animals the figures obtained indicate rapid equilibration with gas tensions in the blood. Bubbles taken from decompressed dead rats may contain 60-80 per cent CO(2). 6. The bearing of these experiments on the mechanisms of bubble initiation and growth in normal living animals is discussed. Reasons are given for suggesting that CO(2), due largely to its high dissolved concentration in localized active regions, may be an outstanding factor in the initiation and early growth of bubbles which in later stages are expanded and maintained principally by nitrogen. PMID- 19873417 TI - THE RELATION OF EXERCISE TO BUBBLE FORMATION IN ANIMALS DECOMPRESSED TO SEA LEVEL FROM HIGH BAROMETRIC PRESSURES. AB - 1. Bullfrogs (Rana catesbiana) and rats have been subjected to high barometric pressures and studied for bubble formation on subsequent decompression to sea level. Pressures varying from 3 to 60 pounds per square inch, in excess of atmospheric pressure, were used. 2. Muscular activity after decompression is necessary for bubble formation in bullfrogs after pressure treatment throughout the above range. Anesthetized frogs remained bubble-free following decompression. Rats compressed at 15 to 45 pounds per square inch likewise did not contain bubbles unless exercised on return to sea level. 3. Bubbles form without voluntary muscular activity in anesthetized rats previously subjected to pressure of 60 pounds per square inch. Small movements involved in breathing and other vital activities are believed sufficient to initiate bubbles in the presence of very high supersaturations of N(2). 4. Bubbles appear (with exercise) in rats previously compressed at 15 pounds per square inch, and in bullfrogs subjected to pressure at levels as low as 3 pounds per square inch above atmospheric pressure. The percentage drop in pressure necessary for bubble formation is less in compressed animals than in those decompressed from sea level to simulated altitudes. 5. The action of exercise on bubble formation in compressed frogs and rats is attributed to mechanical factors associated with muscular activity, combined with the high supersaturation of N(2). CO(2) probably is not greatly involved, since its concentration does not reach supersatuation, as it does at high altitude. 6. Anoxia following decompression from high barometric pressures has no observable facilitating effect on bubble formation. PMID- 19873418 TI - ADDITIONAL MECHANISMS FOR THE ORIGIN OF BUBBLES IN ANIMALS DECOMPRESSED TO SIMULATED ALTITUDES. AB - 1. A heavy ingestion of frothy emulsified fat by rats and bullfrogs does not increase susceptibility to bubble formation when the animals are decompressed 2 to 72 hours later. This indicates that gaseous films (bubble nuclei) initially present do not pass across the intestinal wall with the digested fat, and also that high fat content per se in the lymph and blood does not increase susceptibility to bubble formation. 2. Liquid caprylic acid injected into veins of bullfrogs crystallizes when the frogs are cooled. The crystallization causes bubbles to form without muscular activity on subsequent decompression. Cooling normal bullfrogs to 1-2 degrees C. fails, however, to crystallize any substances occurring naturally in the animals that might act in a similar manner. 3. When bullfrogs are cooled (e.g. to -5 degrees to -10 degrees C.) until ice forms in the blood vessels, and are then warmed and decompressed, bubbles form in the absence of exercise. Crystallization of water in the body thus forms nuclei or even small bubbles that persist. If only one foot is frozen, bubbles originate in the frozen foot. In some cases visible bubbles were observed in thawed feet at sea level (i.e. without decompression). When frog's blood is partly frozen in test tubes or in tied off sections of veins, bubbles will appear on decompression in the absence of mechanical agitation. The practical relation of this phenomenon to flight at high altitude should not be overlooked. 4. Fracturing a leg bone (tibia or femur) in a frog induces bubble formation on subsequent decompression. Bubble nuclei, which persist for (1/2) to 1 hour, are probably formed as a result of the intense mechanical disturbance when the bone snaps. Fracturing of bone is considerably more effective than crushing muscles for producing bubbles in frogs. PMID- 19873419 TI - SOME EFFECTS OF DERIVATIVES OF VITAMIN K ON THE METABOLISM OF UNICELLULAR ALGAE. AB - Vitamin K(1), 2-methyl-3-phytyl-1,4-naphthoquinone, is a substance found in all plant chloroplasts. It is, therefore, interesting to know whether it has any influence upon the metabolism of plants. Experiments made with the phytol-free derivatives like 2-methyl-1,4-naphthoquinone or the corresponding 3-oxy compound, phthiocol, gave the following results. These substances accelerate the respiration of Chlorella or Scenedesmus in a way similar to the action of the dinitrophenols. They inhibit photosynthesis and the compensation of respiration in the light strongly like hydroxylamine. In Scenedesmus they hinder the adaptation to the anaerobic utilization of hydrogen. If given after adaptation in amounts sufficient to stop photosynthesis they do not prevent photoreduction but rather stabilize this reaction against reversion. Their presence destroys the coupling between the reduction of carbon dioxide in the dark and the oxyhydrogen reaction in adapted algae. One can expect, therefore, that the natural vitamin K present in plants in concentrations of about 10(-3)M takes part in some metabolic reaction as a catalyst or regulator. PMID- 19873420 TI - o-PHENANTHROLINE AND DERIVATIVES OF VITAMIN K AS STABILIZERS OF PHOTOREDUCTION IN SCENEDESMUS. AB - It is known that with increasing concentrations of hydroxylamine the rate of photoreduction in the alga Scenedesmus drops to about one-half of the normal rate. From then on photoreduction remains insensitive to hydroxylamine. The present experiments prove that this strange effect is not specific for hydroxylamine. It can be produced with substances having quite different chemical properties, such as o-phenanthroline, 2-methyl-1,4-naphthoquinone (vitamin K), or 2-oxy-3-methyl-naphthoquinone (phthiocol). Once the rate of photoreduction has been brought down to the limit of exactly one-half by a sufficient dose of any one of these substances, the reaction is also stabilized against reversion under the influence of strong light. At saturation intensities the rate of the stabilized photoreduction may be several times that at which the unpoisoned cells revert to photosynthesis. The ratio of one-half between the rates of the stabilized and the normal photoreduction is found at very low light intensities. This indicates a change in the photochemical process. Since the assimilatory quotient remains unaltered, it is the quantum yield which is cut in half under the influence of the poisons. To explain these observations it is assumed that either just one-half of the primary photoproducts are lost, or that they react back entirely while causing a reduction of carbon dioxide in a way similar to that brought about by the oxyhydrogen reaction in the dark. PMID- 19873421 TI - NATURE OF THE GROWTH FACTOR FOR THE COLORLESS ALGA PROTOTHECA ZOPFII. AB - Barker's study on the nutritive requirements of Prototheca zopfii indicated that this colorless alga fails to grow in the absence of small amounts of yeast extract. A study of the growth factor requirements of Prototheca has shown that the active constituent of yeast extract necessary for the growth of this organism is thiamin (vitamin B(1)). Thiamin can fully replace the complex yeast material and allows, in the basal medium used, a maximum cell yield in concentrations of 1 3 x 10(-7)M. Thiamin as such, however, is not essential for the growth of Prototheca zopfii. The alga can develop equally well if supplied with both the thiazole and pyrimidine constituents of this vitamin. These appear to be needed in equimolar proportions. Maximum cell yield is obtained with 3 x 10(-8)M concentrations of the two components. PMID- 19873422 TI - STUDIES ON THE METABOLISM OF THE COLORLESS ALGA PROTOTHECA ZOPFII. AB - The metabolism of Prototheca zopfii was investigated in an attempt to establish the specific function of its growth factor, thiamin. A study of the oxidative decomposition of various substrates by this organism demonstrated that the addition of catalytic amounts of thiamin to vitamin-deficient cells causes a pronounced stimulation in the rate of oxygen utilization during the degradation of certain compounds. The phosphoric ester of thiamin is known to be the prosthetic group of carboxylase. The fact that this enzyme is involved in the decomposition of pyruvic acid suggested that this alpha-keto acid might be an important intermediate product in the metabolism of Prototheca. Pyruvic acid, however, was not included in the list of organic substances which Barker had reported as utilized by this alga. Barker's observations were confirmed, but subsequent experiments led to serious doubts as to the validity of his interpretation. Further investigations resulted in the establishment of environmental conditions which permit this alga to readily decompose pyruvic acid, as well as nearly all other organic acids tested. This can be accomplished by providing a millieu of sufficiently low pH to insure the presence of undissociated acid molecules. The stimulatory effect on the rate of oxygen consumption, caused by the addition of minute amounts of thiamin to suspensions of vitamin-deficient cells of Prototheca respiring pyruvic acid, indicates that the presence of thiamin results in the synthesis of enzyme systems which are involved in the decomposition of pyruvic acid. Experimental data on the oxidation of pyruvic acid and other organic compounds are discussed in the light of various hypotheses which have been advanced concerning the role of carboxylase in the decomposition of pyruvic acid. The conservative conclusion which can be drawn from the available information is that there appears to be no justification for a belief that thiamin and carboxylase are functional in biochemical reactions other than in decarboxylation and carboxylation processes. The discovery of the ability of Prototheca to utilize substituted and dicarboxylic acids led to further studies on the mechanism of oxidative assimilation. The results of these investigations are in agreement with those of Clifton and Logan, and of Doudoroff, and indicate the existence of a relatively simple chemical mechanism of assimilation rather than of a strictly energetic coupling of catabolic and anabolic reactions. A consideration of possible mechanisms for the oxidative assimilation of pyruvic and lactic acids indicates acetic acid as the most likely starting point for the assimilatory process proper. Experimental investigations of the mode of acetate breakdown began with studies on the oxidation of glycolic acid. This substance is shown to be an oxidation catalyst in the metabolism of Prototheca zopfii. The exact nature of the catalytic function has not yet been determined. PMID- 19873423 TI - THE QUANTUM YIELD OF OXYGEN PRODUCTION BY CHLOROPLASTS SUSPENDED IN SOLUTIONS CONTAINING FERRIC OXALATE. AB - 1. The quantum yield of oxygen liberation by spinach and Tradescantia chloroplasts suspended in solutions containing ferric oxalate and potassium ferricyanide varied from 0.013 to 0.080. 2. It was concluded that the nature of this oxygen liberation reaction is not fundamentally different from the formation of oxygen in normal photosynthesis, with respect to its light efficiency. PMID- 19873424 TI - DIFFERING RATES OF DEATH AT INNER AND OUTER SURFACES OF THE PROTOPLASM : III. EFFECTS OF MERCURIC CHLORIDE ON NITELLA. AB - The inner and outer protoplasmic surfaces in Nitella may differ greatly in behavior. When 0.01 M HgCl(2) is applied externally death arrives first at the inner surface. But when 0.01 M HgCl(2) + 0.01 M KCl is applied death takes place sooner at the outer surface. Since 0.01 M KCl by itself is not toxic its effect may be to condition the surface layer chemically or by means of the diffusion potential it sets up (this may amount to 100 mv.). These surfaces consist of non aqueous films forming the boundaries of a layer of aqueous protoplasm not over 10 microns in thickness. These and earlier experiments with formaldehyde and with chloroform show clearly that it is possible to control the behavior of the protoplasmic surfaces so that when a toxic agent is applied it may produce death more rapidly at the inner or at the outer surface according to experimental conditions. PMID- 19873425 TI - THE MECHANISM OF THE INHIBITION OF HEMOLYSIS : II. EFFECTS OF pH ON INHIBITION BY PLASMA AND BY CHOLESTEROL SOLS. AB - The effects of variations of pH, from 5.6 to 8.6, on the lytic activity of saponin, digitonin, and sodium taurocholate, and the effects on the inhibition produced by plasma and by cholesterol sols, are described. The results, so far as they can be analyzed, show that the pH dependence of the inhibition produced by plasma is different from that of the inhibition produced by cholesterol sols, and this leads to the conclusion that a considerable part of the inhibition produced by plasma is due to inhibitory substances other than cholesterol. The results also provide a certain amount of indirect evidence that hemolysis is not due primarily to a reaction of the lysins with the cholesterol of the red cell membrane. PMID- 19873426 TI - THE MECHANISM OF THE INHIBITION OF HEMOLYSIS : III. INHIBITION BY SOLS OF SUBSTANCES RELATED TO CHOLESTEROL. AB - 1. When digitonin is the lysin, the inhibitory power of sols of cholesterol and related substances depends primarily on a normal, as opposed to an epi, configuration of H and OH at C3. Subsidiary inhibitory effects depend on whether the double bond of cholesterol at C5 is saturated or not, and a trans hydrogen at C5 is associated with a greater inhibition than a cis hydrogen. 2. When saponin is the lysin, normal cholesterol is more inhibitory than its epimer. When the double bond at C5 is saturated (cholestanol, coprosterol, and their epimers), the epi configuration is more inhibitory than the normal configuration. This may be associated with the tendency of the epimers to form liquid interpenetrating films with films of digitonin and digitonin-like lysins. 3. At least one of the esters of cholesterol (cholesteryl acetate) has a small but definite inhibitory effect on both digitonin and saponin hemolysis. PMID- 19873427 TI - STREPTOCOCCAL FIBRINOLYSIS: A PROTEOLYTIC REACTION DUE TO A SERUM ENZYME ACTIVATED BY STREPTOCOCCAL FIBRINOLYSIN. AB - 1. Methods for the preparation and partial purification of streptococcal fibrinolysin are described. 2. The lysis of fibrin clots in the presence of streptococcal fibrinolysin is associated with proteolysis of the fibrin. Digestion is due to an enzyme normally present in serum or plasma in an inactive state, which is activated by fibrinolysin. Fibrinolysin alone has no demonstrable proteolytic activity. 3. The lysin factor-fibrinolysin system brings about proteolysis of other proteins such as gelatin or casein, in addition to fibrin and fibrinogen. 4. It is suggested that lysin factor exists in serum or plasma as a zymogen, and that it is activated by fibrinolysin, a kinase, in a manner similar to the activation of trypsinogen by enterokinase or the mold kinase of Kunitz (1938). PMID- 19873428 TI - MAXIMA IN RATE-CONCENTRATION CURVES AND THEIR RELATION TO THE STRUCTURAL ASPECTS OF CELLULAR METABOLISM. AB - 1. Reproducible maxima are exhibited in the rate-concentration curves obtained by studying the effects of ethyl- and phenylurethanes on regeneration rates of hydranths in Tubularia. 2. The general problem of maxima in rate-concentration curves is analyzed in terms of reaction kinetics of relatively simple systems. 3. Certain systems were shown to exhibit this phenomenon. A comparison is made of these with similar ones which fail to do so. 4. The possible role in this phenomenon of cellular structure and its attendant geometrical constraints is discussed in terms of the above comparison. PMID- 19873429 TI - THE EFFECT OF PENICILLIN ON EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA. AB - 1. Penicillin in the range of concentration from 250 U/ml. to approximately 2650 U/ml. inhibits the rate of cell division of the fertilized sea urchin egg from 0 to 100 per cent. 2. Penicillin in the same range of concentrations has no effect on the oxygen consumption of the unfertilized or the fertilized eggs. 3. Penicillin is bound by some component of the sea urchin egg in amounts sufficiently large to lower the initial concentration, this binding apparently not being related to the inhibitory action. PMID- 19873430 TI - THE EFFECT OF PENICILLIN ON METHYLENE BLUE ADSORPTION ONTO ACTIVATED CHARCOAL. AB - Penicillin inhibits the adsorption of methylene blue onto activated charcoal in concentrations as low as 100 units/ml. Penicillin in the low inhibitory concentration of 100 units/ml, antagonizes to a small extent the strong inhibition of MB adsorption by 0.1, 0.2, and 1 per cent peptone. PMID- 19873432 TI - METABOLISM OF TISSUE CULTURES : III. A METHOD FOR MEASURING THE PERMEABILITY OF TISSUE CELLS TO SOLUTES. AB - By using radioactive isotopes in tissue cultures, the rate of permeation of substances into cells can be measured independently of concurrent metabolic reactions of these substances. Techniques of obtaining and analyzing data are described. Examples are given using radioactive potassium and phosphorus. Using cultures of chick embryo muscle, turnover time for cell potassium is 6 hours, and for cell inorganic phosphate is 7 hours in the examples cited. Permeability rates, based on estimates of the cell surface involved and expressed as millimoles per cm.(2) per hour, are of the order of magnitude of 10(-6) for potassium and of 10(-7) for phosphate. PMID- 19873431 TI - IMMUNOCHEMICAL PROPERTIES OF NATIVE AND DENATURED HORSE SERUM GLOBULINS. AB - 1. The influence of guanidine hydrochloride on the denaturation and regeneration of Type I antipneumococcal horse serum globulin was determined by measurements of viscosity, diffusion, and sedimentation in the ultracentrifuge. In addition, the effect of NaCNS on the antibody globulin was studied. 2. Both the irreversibly denatured and the regenerated fractions were found to be precipitable by SI. The observed changes in combining ratio have been tentatively explained in terms of (a) changes in the mean molecular weight, or alternatively (b) an increase in the number of serologically active groups upon denaturation, followed by masking of the latter upon regeneration. Discounting a specific effect of NaCNS on either fraction, the extent of specific precipitation is of the same order of magnitude for native and irreversibly denatured antibody. 3. Quantitative precipitin titrations have been performed on rabbit antisera to native and irreversibly denatured horse antibody, and normal globulin GI, respectively. No significant differences in the antigenic activity of these proteins were found. Measurements of their cross-reactivity led to the conclusion that the native and irreversibly denatured fractions of antibody globulin are antigenically more closely related to each other than to the corresponding fractions of normal globulin, and vice versa. PMID- 19873433 TI - THE NATURE AND CONTROL OF REACTIONS IN BIOLUMINESCENCE : WITH SPECIAL REFERENCE TO THE MECHANISM OF REVERSIBLE AND IRREVERSIBLE INHIBITIONS BY HYDROGEN AND HYDROXYL IONS, TEMPERATURE, PRESSURE, ALCOHOL, URETHANE, AND SULFANILAMIDE IN BACTERIA. AB - On the basis of available data with regard to the chemical and physical properties of the "substrate" luciferin (LH(2)) and enzyme, luciferase (A), and of kinetic data derived both from the reaction in extracts of Cypridina, and from the luminescence of intact bacteria, the fundamental reactions involved in the phenomenon of bioluminescence have been schematized. These reactions provide a satisfactory basis for interpreting the known characteristics of the system, as well as the theoretical chemistry with regard to the control of its over-all velocity in relation to various factors. These factors, here studied experimentally wholly with bacteria, Photobacterium phosphoreum in particular, include pH, temperature, pressure, and the drugs sulfanilamide, urethane, and alcohol, separately and in relation to each other. Under steady state conditions of bacterial luminescence, with excess of oxidizable substrate and with oxygen not limiting, the data indicate that the chief effects of these agents center around the pace setting reactions, which may be designated by the equation: A + LH(2) --> ALH(2) following which light emission is assumed proportional to the amount of the excited molecule, AL*. The relation between pH and luminescence intensity varies with (a), the buffer mixture and concentration, (b), the temperature, and (c), the hydrostatic pressure. At an optimum temperature for luminescence of about 22 degrees C. in P. phosphoreum, the effects of increasing or decreasing the hydrogen ion concentration are largely reversible over the range between pH 3.6 and pH 8.8. The relation between luminescence intensity and pH, under the experimental conditions employed, is given by the following equation, in which I(1) represents the maximum intensity, occurring about pH 6.5; I(2) the intensity at any other given pH; K(5) the equilibrium constant between hydrogen ions and the AL(-); and K(6) the corresponding constant with respect to hydroxyl ions: See PDF for Equation The value of K(5), as indicated by the data, amounts to 4.84 x 10(4), while that of K(6) amounts to 4.8 x 10(5). Beyond the range between approximately pH 3.8 and 8.8, destructive effects of the hydrogen and hydroxyl ions, respectively, were increasingly apparent. By raising the temperature above the optimum, the destructive effects were apparent at all pH, and the intensity of the luminescence diminished logarithmically with time. With respect to pH, the rate of destruction of the light-emitting system at temperatures above the optimum was slowest between pH 6.5 and 7.0, and increased rapidly with more acid or more alkaline reactions of the medium. The reversible effects of slightly acid pH vary with the temperature in the manner of an inhibitor (Type I) that acts independently of the normal, reversible denaturation equilibrium (K(1)) of the enzyme. The per cent inhibition caused by a given acid pH in relation to the luminescence intensity at optimum pH, is much greater at low temperatures, and decreases as the temperature is raised towards the optimum temperature. The observed maximum intensity of luminescence is thus shifted to slightly higher temperatures by increase in (H(+)). The apparent activation energy of luminescence is increased by a decrease in pH. The value of DeltaHdouble dagger at pH 5.05 was calculated to be 40,900 calories, in comparison with 20,700 at a pH of 6.92. The difference of 20,200 is taken to represent an estimate of the heat of ionization of ALH in the activation process, and compares roughtly with the 14,000 calories estimated for the same process, by analyzing the data from the point of view of hydrogen ions as an inhibitor. The decreasing temperature coefficient for luminescence in proceeding from low temperatures towards the optimum is accounted for in part by the greater degree of ionization of ALH. At the optimum temperature and acid reactions, pressures up to about 500 atmospheres retard the velocity of the luminescent oxidation. At the same temperature, with decrease in hydrogen ion concentration, the pressure effect is much less, indicating a considerable volume increase in the process of ionization and activation. In the extremely alkaline range, beyond pH 9, luminescence is greatly reduced, as compared with the intensity at neutrality, and under these conditions pressure causes a pronounced increase in intensity, presumably by acting upon the reversible denaturation equilibrium of the protein enzyme, A. Sulfanilamide, in neutral solutions, acts on luminescence in a manner very much resembling that of hydrogen ions at acidities between pH 4.0 and pH 6.5. Like the hydrogen ion equilibrium, the sulfanilamide equilibrium involves a ratio of approximately one inhibitor molecule to one enzyme molecule. The heat of reaction amounts to about 11,600 calories or more in a reversible combination that evidently evolves heat. Like the action of H ions, sulfanilamide causes a slight shifting of maximum luminescence intensity in the direction of higher temperatures, and an increase in the energy of activation. The effect of sulfanilamide on the growth of broth cultures of eight species of luminous bacteria indicates that there is no regular relationship among the different organisms between the concentration of the drug that prevents growth, and that which prevents luminescence in the cells which develop in the presence of sulfanilamide. p-Aminobenzoic acid (PAB) antagonizes the sulfanilamide inhibition of growth in luminous bacteria, and the cultures that develop are luminous. When (PAB) is added to cells from fully developed cultures, it has no effect on luminescence, or causes a slight inhibition, depending on the concentration. With luminescence partly inhibited by sulfanilamide, the addition of PAB has no effect, or has an inhibitory effect which adds to that caused by sulfanilamide. Two different, though possibly related, enzyme systems thus appear to limit growth and luminescence, respectively. The possible mechanism through which both the inhibitions and the antagonism take place is discussed. The irreversible destruction of the luminescent system at temperatures above that of the maximum luminescence, in a medium of favorable pH to which no inhibitors have been added, proceeds logarithmically with time at both normal and increased hydrostatic pressures. Pressure retards the rate of the destruction, and the analysis of the data indicates that a volume increase of roughly 71 cc. per gm. molecule at 32 degrees C. takes place in going from the normal to the activated state in this reaction. At normal pressure, the rate of destruction has a temperature coefficient of approximately 90,000 calories, or about 20,000 calories more than the heat of reaction in the reversible denaturation equilibrium. The data indicate that the equilibrium and the rate process are two distinct reactions. The equation for luminescence intensity, taking into account both the reversible and irreversible phases of the reaction is given below. In the equation b is a proportionality constant; k' the rate constant of the luminescent reaction; A(0) the total luciferase; A(0i) the total initial luciferase at time t equals 0; k(n) the rate constant for the destruction of the native, active form of the enzyme; k(d) the rate constant for the destruction of the reversibly denatured, inactive form; t the time; and the other symbols are as indicated above: See PDF for Equation For reasons cited in the text, k(n) evidently equals k(d). Urethane and alcohol, respectively, act in a manner (Type II) that promotes the breaking of the type of bonds broken in both the reversible and irreversible reactions and so promotes the irreversible denaturation. This result is in contrast to the effects of sulfanilamide, which at appropriate concentrations may give rise to the same initial inhibition as that caused by urethane, but remains constant with time. The inhibition caused by urethane and alcohol, respectively, increases as the temperature is raised. As a result, the apparent optimum is shifted to lower temperatures, and the activation energy for the over-all process of luminescence diminishes. An analysis for the approximate heat of reaction in the equilibrium between these drugs and the enzyme, indicates 65,000 calories for urethane, and 37,000 for alcohol. A similar analysis with respect to the effect of hydroxyl ions as the inhibitor gives 60,300 calories. The effects of alcohol and urethane are sensitive to hydrostatic pressure. Moderate inhibitions at optimum temperature and pH, caused by relatively small concentrations of either drug, are completely abolished by pressures of 3,000 to 4,000 pounds per square inch. At optimum temperature and pH, increasing concentrations of alcohol caused the apparent optimum pressure for luminescence to shift markedly in the direction of higher pressures. Analysis of the data with respect to concentration of alcohol at different pressures indicated that the ratio of alcohol to enzyme molecules amounted to approximately 4, at 7,000 pounds, but only about 2.8 at normal pressures. This phenomenon was taken to indicate that more than one equilibrium is established between the alcohol and the protein. A similar interpretation was suggested in connection with the fact that analysis of the relation between concentration of urethane and amount of inhibition at different temperatures also indicated a ratio of urethane to enzyme molecules that increased with temperature in the equilibria involved. Analysis of the data with respect to pressure and the inhibition caused by a given concentration of alcohol at different temperatures indicated that the volume change involved in the combination of alcohol with the enzyme must be very small, while the actual effect of pressure is apparently mediated through the reversible denaturation of the protein enzyme, which is promoted by alcohol, urethane, and drugs of similar type. PMID- 19873434 TI - THE TEMPERATURE COEFFICIENT OF THE UREA DENATURATION OF EGG ALBUMIN. AB - Evidence is brought forward to show that at concentrations of urea high enough to split the egg albumin molecule the solubility changes produced by urea are profoundly modified. The degree of precipitation after dialysis is the net result of two changes produced by the urea: the first, normally spoken of as denaturation, which makes the protein insoluble in dilute solution and the second, a splitting of the molecule which makes it soluble. These two reactions may proceed independently and simultaneously or the second reaction may follow the first, taking place in the denatured molecule only. In view of the decrease in the opalescence with time, the latter process is more probable. Both of these reactions have positive temperature coefficients, but as the concentration of urea increases the second reaction is more affected by increase in temperature than the first, and consequently the resulting opalescence decreases rather than increases with temperature. This accounts for and explains reports of negative temperature coefficients of denaturation, when denaturation is measured by the amount of insoluble material found on dilution. The occurrence of these two reactions, one leading to an increase and the other to a decrease in the amount of insoluble protein, should be taken into account when denaturation changes in egg albumin with urea are studied. PMID- 19873435 TI - THE EFFECTS OF OXYGEN, CARBON DIOXIDE, AND PRESSURE ON GROWTH IN CHILOMONAS PARAMECIUM AND TETRAHYMENA GELEII FURGASON. AB - 1. The effects of O(2), CO(2), and pressure were studied in two very different species of protozoa, a flagellate, Chilomonas paramecium, grown in acetate ammonium solution and a ciliate, Tetrahymena geleii, grown in 2 per cent proteose peptone solution. 2. Chilomonas and Tetrahymena live and reproduce in solutions exposed to a wide range of O(2) concentrations, but Chilomonas is killed at high O(2) tensions in which Tetrahymena grows best. The optimum O(2) concentration for Chilomonas is about 75 mm. pressure but it lives and reproduces in O(2) tensions as low as 0.5 mm. while Tetrahymena fails to grow in concentrations below 10 mm. O(2) pressure. 3. With a constant O(2) tension of 50 mm. pressure, it was found that there is no significant variation in growth in Chilomonas between 50 mm. and 740 mm. total pressure. In Tetrahymena, however, under the same conditions, an optimum total pressure was found at about 500 mm. and growth is comparatively poor at 50 mm. total pressure. 4. Tetrahymena does not live very long in CO(2) tensions over 122 mm., although Chilomonas grows as well at 400 mm. CO(2) as in air at atmospheric pressure (0.2 mm. CO(2)). Tetrahymena grows best in an environment minus CO(2), but the optimum for Chilomonas is 100 mm. CO(2) at which pressure an average of 668,600 +/- 30,000 organisms per ml. was produced (temperature, 25 +/- 1 degrees C.). 5. Chilomonads grown in high CO(2) concentrations (e.g., 122 mm.) produce larger starch granules and more starch than those grown in ordinary air at atmospheric pressure. 6. In solutions exposed to 75 mm. O(2) tension (optimum) and 122 mm. CO(2) plus 540 mm. N(2) pressure, chilomonads contain very little, if any, fat. This phenomenon seems to be due to the action of CO(2) on the mechanisms concerned with fat production. 7. In Tetrahymena exposed to pure O(2), there is very little fat compared to those grown in atmospheric air. This may be due to the greater oxidation of fat in the higher O(2) concentrations. 8. Further evidence is presented in support of the contention that Chilomonas utilizes CO(2) in the production of starch. PMID- 19873436 TI - A PROTEOLYTIC ENZYME OF SERUM: CHARACTERIZATION, ACTIVATION, AND REACTION WITH INHIBITORS. AB - 1. Fibrinolysin-activated lysin factor and chloroform-activated serum protease of serum and plasma are one and the same enzyme, differing only in their mode of activation. 2. The enzyme as it normally occurs in serum or plasma is not inactive because of combination with serum inhibitor. It is present as an inactive precursor or zymogen and may be activated from this state by streptococcal fibrinolysin. 3. The activation of serum protease by streptococcal fibrinolysin is a catalytic reaction, analogous to the kinase activation of trypsinogen by enterokinase. Treatment of serum or plasma with chloroform apparently results in removal of serum inhibitor which may allow autocatalytic activation of the serum protease. 4. The serum enzyme differs from trypsin in its pH of optimum activity, in its reactions with specific protease inhibitors, and in its action on casein. 5. A revised nomenclature for the serum enzyme system is suggested which more accurately describes its properties than the terms in current use. PMID- 19873437 TI - STUDIES ON THE pH AND Eh OF NORMAL AND INFLUENZA-INFECTED EGGS. AB - 1. pH values of allantoic fluids from non-infected eggs showed a rapid drop from the 12th to the 17th day of embryonic development. A definite age-pH relationship was shown to exist. 2. The allantoic fluid of eggs infected with influenza virus, contrasting with the non-infected eggs, revealed pH values which remained relatively stable about the neutral point at any age between 11 and 17 days. No relationship between pH and age could be established, in the infected series. 3. The Eh value of the fluid from non-infected eggs also exhibited a significant relationship to embryonic age. The majority of the determinations revealed a positive potential. 4. Similar determination on influenza-infected eggs gave results of a predominantly negative potential, indicating a marked state of reduction accompanying virus multiplication. As with the pH determinations, the Eh values of infected eggs were not a function of their age. PMID- 19873438 TI - THE RHEOLOGY OF THE BLOOD. V. AB - A study has been made of those proteins which might offer exceptions to the law that the fluidity of a protein solution is a linear function of the volume concentration; viz., egg albumin, serum albumin, pseudoglobulin, euglobulin, gelatin, and sodium caseinogenate. Solutions of egg albumin below 20 per cent by weight obey the above law but somewhat below 30 per cent the fluidities begin to be too high, presumably due to the contribution to the fluidity made by the deformation of the particles as they come into contact, as the fluidity approaches zero. The fluidity of serum albumin solutions shows a similar behavior, being exceptional above 15 per cent in weight. Pseudoglobulin and euglobulin give fluidity-concentration curves (Fig. 4) which are linear up to about 2.5 per cent each in a total range of 20 and 14 per cent respectively. From this singular point both compounds show a second range which is linear. Pseudoglobulin is the only substance whose solutions seem to show a third linear range. We have also used the data of Chick and Martin for sodium caseinogenate and found evidence for two linear regimes. It is desirable at this time to call attention to the measurements of the flow of glycogen solutions by Botazzi and d'Errico (14) which in Fluidity and See PDF for Structure plasticity, page 207, are expressed in rhes. The data show two linear fluidity curves of different slopes. In this case it was definitely known that the data for each curve were measured with different viscometers which suggested the possibility of an error in viscometry entering in to confuse the issue. We have no suspicions as to the reliability of the data studied in this paper; we only wish to caution the readers that our hypotheses based on these data must be regarded with due reserve until confirmed. We have found a formula (11) based on the supposed linear relation between logarithmic fluidities and concentration which is convenient to use within the range, but close examination reveals that it does not reproduce the data for the higher concentrations at 25 degrees nor does it permit extrapolation to pure water It is not realistic enough because it does not contemplate any change of regime in going from viscous to non-Newtonian or plastic flow. The formula does not apply to any other of the proteins studied in this paper nor to the great majority of proteins already reported as following the linear law. These are serious objections. We have therefore offered as an alternative a simple formula (24) according to which the fluidities are additive in the viscous regime. When the emulsoid particles approach close packing, they are deformed and this deformation contributes to the flow and the fluidity volume concentration curve is again linear. In fact, there may be one or more additional changes of regime. PMID- 19873439 TI - THE MECHANISM OF THE INHIBITION OF HEMOLYSIS : IV. THE TYPES OF REACTION INVOLVED. AB - This paper contains a description of some of the inhibitory, and occasionally acceleratory, effects of sols of lecithins, cholesterol, and proteins in hemolytic systems containing simple lysins, together with investigations on the nature of the reactions by means of which the effects are brought about. The principal conclusions are: A. As regards sols of lecithins. 1. In lysin-inhibitor cell systems, distearyl lecithin is an inhibitor of saponin and digitonin hemolysis, part of the effect being the result of a reaction with the components of the red cell surface and part being the result of a reaction with lysin in the bulk phase of the system. Lecithin ab ovo (Merck) is an accelerator of saponin hemolysis and either an accelerator or an inhibitor of digitonin hemolysis according to the initial concentration of lysin present in the system. Soybean lecithin is an inhibitor of both saponin and digitonin hemolysis, but both soybean lecithin and lecithin ab ovo contain also a hemolytic, or acceleratory, component. 2. The inhibitory effects depend on the order in which the components of the hemolytic system are mixed together. Distearyl lecithin is about 5 times more inhibitory in cell-inhibitor-lysin systems than in lysin-inhibitor-cell systems containing saponin, digitonin, or taurocholate. Lecithin ab ovo is more inhibitory in cell-inhibitor-lysin systems when the time of contact between cells and inhibitor is short, but when it is long, the hemolytic properties of the lecithin offset its inhibitory properties. A similar state of affairs is observed with soybean lecithin. 3. An increase in temperature decreases the inhibitory effect of distearyl lecithin in systems containing saponin or digitonin. B. As regards sols of cholesterol. 4. The quantity of lysin Delta apparently inhibited by a quantity Q of cholesterol sol is dependent on both the type of red cell and the number of red cells added to the system. 5. Delta is a non-linear function of Q and of c(1), the initial quantity of lysin present in the hemolytic system, Delta generally increasing as c(1) increases. 6. The inhibitory effect of cholesterol sols is essentially due to a reaction between the cholesterol and the lysin in the bulk phase of the system, modified by what appear to be redistribution effects which depend on the kind and number of red cells added to complete the hemolytic system. 7. The value of Delta depends on the temperature and on the length of time during which the cholesterol and the lysin remain in contact before the addition of the cells. 8. Distearyl lecithin considerably enhances the inhibitory effects of cholesterol sols. C. As regards the proteins. 9. Freshly prepared serum globulin is inhibitory in systems containing saponin, digitonin, taurocholate, and oleate, and the effect is due to reactions in the bulk phase of the system, modified by redistribution effects. 10. Serum albumin either accelerates or inhibits lysis by saponin, depending on the initial concentration of lysin, and the inhibition depends on such factors as the type of red cell used and the time of contact. In the case of sodium taurocholate, the inhibition has a very marked pH dependence. D. As regards plasma. 11. The way in which the inhibitory effect depends on the length of time during which inhibitor and lysin are in contact before the addition of the cells is not the same when plasma is used as an inhibitor as when a cholesterol sol is used as the inhibitor. The amount of cholesterol sol which is equal in inhibitory power to a given amount of plasma accordingly varies according to the length of the time of contact which is selected. 12. The inhibitory effect in systems containing saponin, plasma, and red cells can be shown to depend on the order in which the components are mixed, when the concentration of the plasma is small. 13. The question as to how much of the inhibitory power of plasma can be accounted for by the contained cholesterol (total or free) is one which can be answered only if the experimental conditions are defined with respect to initial concentration of lysin, time of contact, and several other variables. Very roughly, about 50 per cent of the total inhibition of plasma, or a little more, can be attributed to the cholesterol fraction. 14. Since the inhibitory effects of plasma are the result of reactions in the bulk phase of the system, complicated by redistributions among the phases, of reactions between some of its components and components of the red cell surface, and of enhancing effects of its components upon each other, it is not surprising that nothing better than an empirical expression should have been found to describe the inhibition quantitatively. PMID- 19873440 TI - THE TOXICITY OF COPPER NITRATE SOLUTIONS TO POLYCELIS NIGRA : II. THE DUPLEX TOXIC MECHANISM AND THE SYNERGIC EFFECT OF ADDED SOLUTES. AB - The estimation of the number of variables operating in cases of toxic action toward living organisms is discussed. The toxicity of glucose, sodium chloride, and copper nitrate solutions to Polycelis nigra has been investigated and also that of copper nitrate solutions whose osmotic pressure was adjusted to a constant level by the addition of glucose or of sodium chloride. It is shown that hypertonic solutions of copper nitrate are abnormally toxic but that the osmotic variable is not the factor responsible for this abnormally high toxicity. The lack of data which might elucidate such problems is indicated. During the course of this work it was observed that mixed solutions of copper nitrate + sodium chloride and copper nitrate + glucose exhibit toxicities greater than those expected from consideration of the separate toxicities of the components of the mixtures. PMID- 19873441 TI - EFFECTS OF HYDROXYL ON NEGATIVE AND POSITIVE CELLS OF NITELLA. AB - Remarkable changes are brought about by KOH in transforming negative cells of Nitella (showing dilute solution negative with KOH) to positive cells (showing dilute solution positive with KOH). NaOH is less effective as a transforming agent. This might be explained on the ground that the protoplasm contains an acid (possibly a fatty acid) which makes the cell negative and which is dissolved out more rapidly by KOH than by NaOH, as happens with the fatty acids in ordinary soaps. Part of a negative cell can be changed to positive by exposure to KOH while the untreated portion remains negative. After exposure to KOH the potential the protoplasm has when in contact with NaCl may increase. At the same time there may be an increase in the potassium effect; i.e., in the change of P.D. in a positive direction observed when 0.01 M KCl is replaced by 0.01 M NaCl. In some cases the order of ionic mobilities is u(K) > v(OH) > u(Na). This shows that the protoplasmic surface cannot be a pore system: for in such a system all cations must have greater mobilities than all anions or vice versa. PMID- 19873442 TI - THE ACCELERATION OF SAPONIN HEMOLYSIS BY PROFLAVINE. AB - Proflavine is a very powerful accelerator of saponin hemolysis of rabbit, human, and dog erythrocytes. Lysolecithin hemolysis, on the other hand, is inhibited. Dog erythrocytes in the presence of proflavine undergo marked changes in shape, finally becoming rods of about 13 micro in length. Rabbit and human erythrocytes are not altered in form under these conditions. PMID- 19873443 TI - ON THE NATURE OF FORCES OPERATING IN BLOOD CLOTTING : I. THE PARTICIPATION OF ELECTROSTATIC ATTRACTION. AB - THE RESULTS OF THE STUDY OF THE INHIBITING EFFECT OF NEUTRAL SALTS UPON THE CLOTTING TENDENCY OF FIBRINOGEN BY THROMBIN MAY BE SUMMARISED AS FOLLOWS: Salts like NaCl and KCl inhibit only weakly. Salts of the same cation (K(*)) with monovalent anions of different ionic radius are the more active the larger the anion (Cl',Br',I'). Salts of the same cation with anions of different valency are the more active the higher the charge of the anion (1-1 <1-2 <1-3 <1-4). Salts with the same anion with cations of different valency show stronger inhibition in the case of cations of higher charge (K(*),Na(*) < Mg(**), Ca(**), Sr(**), Ba(**)). Salts with the same anion and cations of the same charge, but of different radius, are the more active the larger the cation (but with an inversion between Mg(**) and Ca(**) in the series of the alkali earths, which is not infrequent in biocolloids). These results show that the clotting of fibrinogen with thrombin is, at least partly, caused by a coacervation process, due to electrostatic attraction between positive and negative groups. Its nature and localisation will be dealt with in the next paper of this series. PMID- 19873444 TI - ON THE NATURE OF FORCES OPERATING IN BLOOD CLOTTING : II. THE CLOTTING OF FIBRINOGEN AS A TWO-STEP REACTION. AB - It is found that clotting of fibrinogen by thrombin does not occur on the acid side of the isoelectric point of the fibrinogen. At such pH values, however, a primary reaction between thrombin and fibrinogen takes place, leading to the formation of profibrin, a compound of thrombin and fibrinogen. At pH values at which clotting is possible, fibrinogen is negatively, thrombin positively charged, whereas profibrin has a pattern of positive and negative charges. The primary reaction, the formation of profibrin by combination of thrombin and fibrinogen, is inhibited by urea but not by neutral salts. The combination of thrombin with fibrinogen most probably takes place by hydrogen bonds. The second reaction, the polymerisation of profibrin to fibrin, is inhibited by neutral salts in the same way as complex or autocomplex coacervates. It is caused therefore by electrostatic attraction between the positive and the negative charges of the profibrin. PMID- 19873445 TI - THE EFFECTS OF CAFFEINE ON OXYGEN CONSUMPTION AND CELL DIVISION IN THE FERTILIZED EGG OF THE SEA URCHIN, ARBACIA PUNCTULATA. AB - 1. By means of the Warburg-Barcroft microrespirometer apparatus and the Warburg direct method, the relative effect of caffeine upon the O(2) consumption of the fertilized egg of Arbacia punctulata was shown for the following concentrations in sea water: 0.002 per cent (M/10,000), 0.004 per cent (M/5,000), 0.02 per cent (M/1,000), 0.1 per cent (M/200), 0.2 per cent (M/100), 0.5 per cent (M/40), and 2 per cent (M/10). 2. In comparison with the normal eggs (uninhibited, non-caffeine treated controls), caffeine in concentrations including and greater than 0.1 per cent (M/200) depressed the average uptake from approximately 25 to 61 per cent over the 3 hour period. In a number of instances, as typified by Experiment 10, the effective inhibitory concentration ranged from 0.02 per cent (M/1,000) upward and the degree of depression of the O(2) consumption ranged from 10.6 per cent to 60.6 per cent. 3. All caffeine concentrations including and above 0.02 per cent (M/1,000) in the series used, resulted in decreasing the normal rate of cleavage division in the fertilized Arbacia eggs. 4. The higher concentrations (0.5 and 2 per cent) produced a complete blockage of the cleavage process. 5. Complete cleavage inhibition was noted only when the O(2) uptake had been depressed to 50 per cent or more of the normal controls. 6. O(2) consumption-time relationship data indicate an average depression, in O(2) consumption over a 3 hour period, ranging from 25 per cent with a caffeine concentration of 0.1 per cent to a 61 per cent inhibition with a concentration of 2 per cent. 7. Concentrations of less than 0.1 per cent (certainly of less than 0.02 per cent) give variable results and indicate no significant effect. 8. It is inferred from the respiration data presented that it is probable that the inhibition of the O(2) consumption in fertilized Arbacia eggs is due to the influence of caffeine upon the main (activity or primary) pathway. It will be observed that there are certain similarities of the caffeine data to the degree of inhibition accomplished by sodium cyanide. Moreover, it has been demonstrated that the cyanide probably acts on the cytochrome oxidase step in the cytochrome oxidase-cytochrome chain of reactions constituting the O(2) uptake phase of respiratory metabolism. It is not improbable, therefore, that caffeine also may act upon the cytochrome oxidase enzyme. 9. From the viewpoint of environmental conditions influencing reproductive phenomena, it is of interest that caffeine can affect the normal metabolism of the zygote. PMID- 19873446 TI - WATER RELATIONS IN THE CELL : I. THE CHLOROPLASTS OF NITELLA AND OF SPIROGYRA. AB - Chloroplasts may contract under natural conditions and give up water to the rest of the cell, thus indicating changes in metabolism or constitution. Such contractions may be produced experimentally. In Nitella the chloroplasts are ellipsoid bodies which, under natural conditions, may contract to spheres with a loss of volume. This may be brought about by lead acetate, ferric chloride, and digitonin: the contraction may occur while the cell is alive. The contraction in lead acetate is reversible (in lead nitrate little or no contraction occurs). In Spirogyra the chloroplast is a long, spirally coiled ribbon which may contract under natural conditions to a short nearly straight rod with a loss of volume. This can be brought about by inorganic salts and in other ways while the cell is still alive. PMID- 19873447 TI - THE ACTION SPECTRUM OF SENSITIZATION TO HEAT WITH ULTRAVIOLET LIGHT. AB - 1. Heat does not sensitize paramecia to ultraviolet light but ultraviolet light sensitizes them to heat. Paramecia of two species (Paramecium caudatum and P. multimicronucleate) are much more readily killed by heat at 42.3 degrees C. if they are first exposed to ultraviolet light. 2. From studies on paramecia irradiated with a given dosage at various wave lengths before being killed by heat, an action spectrum of the compound in the protoplasm being sensitized to heat can be determined. Proteins with absorption similar to that of pseudoglobulin are suggested by these experiments. 3. The effect upon living things differs from that on pure protein systems in that paramecia are not rendered more sensitive to temperatures below the lethal temperature whereas proteins are. 4. Almost complete recovery from ultraviolet light as judged by heat sensitivity occurs within 4 to 5 days. 5. By a study of the rate of recovery from doses at different wave lengths evidence suggesting effects on nucleic acid is obtained. 6. The possible significance of the data and the action spectrum is discussed. PMID- 19873448 TI - THE PARACRYSTALLINE STATE OF THE RAT RED CELL. AB - When washed rat red cells are kept in 3 per cent sodium citrate at low temperatures (4-9 degrees C.), their resistance to osmotic hemolysis increases so that after several days they swell very little in hypotonic solutions (R = 0.15 to zero) and do not hemolyze even in distilled water. In this and in other respects they behave as if they were gelated or paracrystalline. The paracrystalline state is reversible, disappearing when the cells are warmed and rapidly reappearing when they are cooled, and the resistance to hypotonic hemolysis is not due to the cells reaching equilibrium with their environment by losing so much K that the concentrations become equal inside and out. The concentration of K remains about 25 times as great inside the cell as outside it in a hypotonic medium of T = 0.1, and the failure to swell and to hemolyze seems to be due to the activity of K in the interior of the paracrystalline cell approaching zero. The paracrystalline red cells are more resistant to saponin and digitonin hemolysis, and do not undergo the usual shape transformations, probably because they are too rigid. Hemolysis by saponin and similar lysins occurs without sphere formation, and after lysis is complete a granular debris is left behind. The paracrystalline cells show a diffuse birefringence with polarized light; on their being warmed, the birefringence disappears except at foci which are usually situated along the rim of the cell. The occurrence of the paracrystalline state accounts for the different amounts of swelling of red cells which have been observed in systems of the same degree of hypotonicity, and its relation to other metastable states of the red cell is discussed in connection with a tabulation of the metastable states of the mammalian red cell and their relation to one another. Changes in a membrane alone seem inadequate to account for the varied phenomena observed in connection with red cell behavior, the explanation of which appears to require a more detailed knowledge of the molecular architecture of the cell interior. PMID- 19873449 TI - PURIFICATION AND PROPERTIES OF DESOXYRIBONUCLEASE ISOLATED FROM BEEF PANCREAS. AB - 1. A method is described for the isolation and purification of desoxyribonuclease from a 0.25 N sulfuric acid extract of beef pancreas. The activity of the enzyme is measured by a viscosimetric method using sodium desoxyribonucleate from calf thymus as substrate. 2. The enzyme is highly active, a measurable effect being obtained at concentrations of less than 0.01 microgram per cc. In highly dilute solution the enzyme is rapidly inactivated, and the use of a protective agent such as gelatin or peptone is necessary. 3. The purified material contains traces of a proteolytic enzyme, but displays no ribonuclease, lipase, or phosphatase activity. 4. The enzyme requires activation by magnesium or manganese ion, and citrate serves as a potent inhibitor of the magnesium-activated enzyme. 5. Its enzymatic activity is inhibited by the specific antibody present in the serum of rabbits immunized with enzyme protein. PMID- 19873450 TI - ISOLATION OF PURE HEXOKINASE FROM YEAST. PMID- 19873452 TI - CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR. PMID- 19873451 TI - ISOLATION OF CRYSTALLINE HEXOKINASE AND OTHER PROTEINS FROM YEAST. PMID- 19873453 TI - AN IMPROVED METHOD FOR THE CRYSTALLIZATION OF TRYPSIN. PMID- 19873454 TI - THE EFFECTIVENESS OF THE SPECTRUM IN CHLOROPHYLL FORMATION. AB - 1. Although the carotenoid pigments are present in large concentration in the plastids of etiolated Avena seedlings as compared with protochlorophyll, the pigment precursor of chlorophyll, it is possible to show that the carotenoids do not act as filters of the light incident on the plant in the blue region of the spectrum where they absorb heavily. This suggests that the carotenoids are located behind the protochlorophyll molecules in the plastids. 2. Since the carotenoids do not screen and light is necessary for chlorophyll formation, an effectiveness spectrum of protochlorophyll can be obtained which is the reciprocal of the light energy necessary to produce a constant amount of chlorophyll with different wavelengths. The relative effectiveness of sixteen spectral regions in forming chlorophyll was determined. 3. From the effectiveness spectrum, one can conclude that protochlorophyll is a blue-green pigment with major peaks of absorption at 445 mmicro, and 645 mmicro, and with smaller peaks at 575 and 545 mmicro. The blue peak is sharp, narrow, and high, the red peak being broader and shorter. This differs from previous findings where the use of rougher methods indicated that red light was more effective than blue and did not give the position of the peaks of absorption or their relative heights. 4. The protochlorophyll curve is similar to but not identical with chlorophyll. The ratio of the peaks of absorption in the blue as compared to the red is very similar to chlorophyll a, but the position of the peaks resembles chlorophyll b. 5. There is an excellent correspondence between the absorption properties of this "active" protochlorophyll and what is known of the absorption of a chemically known pigment studied in impure extracts of seed coats of the Cucurbitaceae. Conclusive proof of the identity of the two substances awaits chemical purification, but the evidence here favors the view that the pumpkin seed substance, which is chemically chlorophyll a minus two hydrogens, is identical with the precursor of chlorophyll formation found in etiolated plants. PMID- 19873455 TI - SOME PROPERTIES OF PROTOPLASMIC GELS : I. TENSION IN THE CHLOROPLAST OF SPIROGYRA. AB - The chloroplast of Spirogyra is a long, spirally coiled ribbon which may contract to form a short, nearly straight rod. This happens under natural conditions and it can also be produced by a variety of inorganic salts and by some organic substances. It also occurs when the chloroplast is freed by centrifugal force from the clear peripheral protoplasm which is in contact with the cellulose wall. It would therefore seem that the chloroplast may be passively stretched by the action of the clear protoplasm and hence it contracts as soon as it is set free. This contraction happens in dead as well as in living cells. It would be of much interest to know how the protoplasm brings about the coiling of the chloroplast and how the chloroplast is set free by various reagents. Presumably they must penetrate the living protoplasm to produce the effects described. In one species partial contraction without detachment from the peripheral protoplasm can be brought about by lead acetate. This is reversible. Lead nitrate does not produce this result. The attack upon the problem is greatly facilitated by the study of dead cells. Thereby we reduce the number of variables but the chloroplast continues to react to certain chemical and physical agents in much the same manner as in the living cell and the solution surrounding it can be controlled as is not possible in the living cell. We must await further investigation to learn what plant and animal cells contain gels under tension and what functions they perform. PMID- 19873456 TI - SENSITIZATION OF CELLS TO HEAT BY VISIBLE LIGHT IN PRESENCE OF PHOTODYNAMIC DYES. AB - 1. Visible light of high intensity does not injure paramecia or sensitize them to heat. 2. If photodynamic dyes are added, paramecia are readily killed by visible light of high intensity and are sensitized to heat by sublethal dosages of light. 3. Cells so sensitized are killed when subjected to a sublethal exposure to heat. 4. If the light and heat are applied in the reverse order, namely, heat and then light, no ill effects are observed. 5. When the concentration of dye is reduced a larger light dosage is required. 6. Recovery from sensitization is slow, requiring about 4 days for a (3/4) lethal dosage. 7. Sublethal dosages of light in the presence of dyes do not affect the division rate even when (3/4) the lethal dosage has been used. 8. A possible explanation for the photodynamic sensitization to heat is discussed. PMID- 19873457 TI - THE MECHANISM OF THE INHIBITION OF HEMOLYSIS : V. INHIBITORY PROCESSES OCCURRING IN THE COURSE OF SIMPLE HEMOLYTIC REACTIONS. AB - This paper is concerned with hemolytic systems containing sodium taurocholate, sodium glycocholate, or saponin, and either human red cells or the ghosts (stromata) of human red cells. The lysins are allowed to react with the cells for a short time (1 minute or less), and with the ghosts for a long time (4 hours), and the quantity of lysin remaining in the bulk phase, after the removal of the cells or of the ghosts, is found by (a) colorimetric methods, and (b) methods which measure its hemolytic activity. In the experiments in which the lysins react with the cells for a time so short that none of them is hemolyzed, it is found: (1) that the suspension medium of a cell suspension contains inhibitory substances which render a small amount of the lysin non-lytic, (2) that on the addition of the lysin to the cell suspension, a further and much larger amount of lysin is rendered non-lytic, and (3) that the quantity of chromogenic material in the bulk phase, after the lysin has been in contact with the cells and the latter have been removed, is substantially the same as that initially present. No appreciable quantity of lysin, accordingly, accumulates in increased concentration at the cell surfaces. The results of the colorimetric determinations show that the apparent disappearance of lysin from the bulk phase, once thought to be due to an accumulation of lysin at the cell surfaces, is the result either of an inhibitory process or of a sudden utilization of lysin unrecognized by existing theory. In the experiments in which the lysins react with stromata for 4 hours, it is found: (1) that the suspension medium of a stroma suspension contains inhibitory substances which render some of the lysin non-lytic, (2) that when the lysin reacts with the stromata over a period of time, a much greater quantity of lysin is rendered non-lytic, and (3) that the concentration of chromogenic material in the bulk phase of the lysin-stroma system, after 4 hours of reaction, is substantially the same as it was initially. The observations can be accounted for by supposing that the lysin molecules are as chromogenic after reacting with the cell components as before, and by their not being bound to the cell or to the ghost, but diffusing back, combined with the components with which they have reacted, into the bulk phase. Such a process would have similarities to the process of penetration and breakdown of mixed protein-lipoid films. Because it is not possible at present to decide how much of the lysin is rendered inert because of utilization in a reaction with cell components, and how much because of the effect of inhibitory substances, difficulties and uncertainties arise in connection with the expressions which have been used to describe the kinetics of hemolysis. PMID- 19873458 TI - PROTEOLYTIC ENZYMES : I. THE CONTROL OF THEIR ACTIVITY. AB - 1. The literature on conditions affecting the activity of proteolytic enzymes has been reviewed. 2. Experimental data on the control of the activity of trypsin, leucoprotease, papain, serum antiprotease, leucopeptidase, and pancreatic peptidase have been presented. These data indicate that: (a) The polymorphonuclearleucocytes of the cat contain abundant proteinase and peptidase active at neutral pH; those of the rabbit lack proteinase active at neutral pH. (b) Reducing agents, including several biologically important thiol-sulfhydryl compounds and ascorbic acid, inhibit the activity of leucoprotease and trypsin. For each reductant the degree of inhibition is proportional to the reducing capacity of the medium. (c) p-Aminobenzoic acid, sulfonamides (especially sulfathiazole), and many diphenyl sulfones inhibit the activity of leucoprotease. (d) Serum, plasma, several heavy metals, ammonium salts, asparagine, thiourea, heparin, glutamic acid, tyrothricin, calcium chloride, and bile salts and bile acids also inhibit the activity of leucoprotease, and in most cases of trypsin too. (e) Preparations of tryptic digests of proteins, and egg white trypsin inhibitor, inhibit trypsin to a much greater degree than leucoprotease. (f) Mild oxidizing agents increase the activity of leucoprotease and trypsin. (g) Oxidizing agents and some inhibitors of sulfhydryl groups inhibit the antiproteolytic activity of the serum. It is suggested that serum antiprotease may consist (chiefly) of reducing agents, including thiol-sulfhydryl peptides which exert their antiproteolytic activity by virtue of the presence of sulfhydryl groups. (h) The antiproteolytic activity of the serum is progressively weakened by exposure to a hydrogen ion concentration below pH 6.5 or above pH 9.7. Because of this the pH optima of leucoprotease and trypsin are shifted in the presence of serum from pH of 7 and 8 to pH of 6 to 6.5, and the range of activity of these enzymes is slightly widened, in both acid and alkaline reactions. (i) Reducing agents increase the activity of leucopeptidase and pancreatic peptidase. Serum, sulfathiazole, and thiourea have little or no effect. 3. The significance of the oxidation-reduction system in the control of the activity of leucoprotease, trypsin, serum antiprotease, leucopeptidase, and pancreatic peptidase has been emphasized. PMID- 19873459 TI - PROTEOLYTIC ENZYMES : II. THE PHYSIOLOGICAL SIGNIFICANCE OF THE CONTROL OF THEIR ACTIVITY, ESPECIALLY WITH RESPECT TO BACTERIAL GROWTH. AB - IT HAS BEEN SUGGESTED THAT THE ABILITY TO CONTROL THE ACTIVITY OF LEUCOPROTEASE AND SERUM ANTIPROTEASE MAY PROVE USEFUL IN THE FURTHER STUDY AND UNDERSTANDING OF SUCH PHENOMENA AS: (1) inflammation; (2) the resolution of inflammatory exudates and the absorption of absorbable foreign bodies; (3) the protection of joint and other structures from the proteolytic action of leucoprotease; (4) the neutralization of the destructive protease liberated in acute pancreatitis and from duodenal fistulae; (5) experimental arteriosclerosis and arteriolonecrosis; (6) the coagulation of the blood; (7) the possibility of prolonging the action of insulin; (8) the release of thyroglobulin by the thyroid gland; (9) bacterial growth and sulfonamide action. In this last respect evidence has been presented that the products of the hydrolysis of protein by leucoprotease stimulate bacterial growth and directly and indirectly inhibit sulfonamide action, and the hope has been expressed that the ability to control leucoprotease action may contribute to the more successful use of chemotherapeutic agents in purulent lesions. PMID- 19873460 TI - NERVE AS MODEL TEMPERATURE END ORGAN. AB - Rapid local cooling of mammalian nerve sets up a discharge which is preceded by a local temperature potential, the cooled region being electronegative relative to a normal portion of the nerve. Heating the nerve locally above its normal temperature similarly makes the heated region electronegative relative to a region at normal temperature, and again a discharge is set up from the heated region. These local temperature potentials, set up by the nerve itself, are held to serve as "generator potentials" and the mechanism found is regarded as the prototype for temperature end organs. PMID- 19873461 TI - THE EXTRACELLULAR RELEASE OF ECHINOCHROME. AB - A study was made of the diffusion of the red pigment echinochrome from the eggs of the sea urchin, Arbacia punctulata, into sea water. Unfertilized eggs retained their pigment, over periods of hours. Outward diffusion of pigment from unfertilized eggs normally is entirely negligible, or does not occur at all. Enchancing the calcium or potassium content of the artificial sea water (while retaining isosmotic conditions) did not induce pigment release. Under anaerobic conditions, unfertilized eggs release pigment in small quantities. Fertilization alone brings about echinochrome release. Fertilized eggs invariably released pigment, whether in normal sea water, or sea water with increased calcium or potassium. This diffusion of the pigment began during the first cleavage, possibly soon after fertilization. The pigment release is not a consequence solely of the cell's permeability to echinochrome (or chromoprotein, or other pigment combination) but is preceded by events leading to a release of echinochrome from the granules in which it is concentrated within the cell. These events may be initiated by activation or by anaerobiosis. The phenomenon was not due to cytolysis. PMID- 19873462 TI - THE CHEMISTRY OF DAYLIGHT VISION. AB - 1. While several reports of photosensitive pigments from the retinas of animals possessing large numbers of cone cells have been published, the only study which could be confirmed was Wald's discovery of iodopsin, a red-sensitive pigment from chicken eyes. 2. In its chemical properties, such as the range of pH stability and the effect of polar organic solvents, iodopsin resembles rhodopsin but is considerably more labile. 3. A partial purification from inert yellow impurities has been effected by prehardening the retinas in pH 4.9 acetate buffer before extraction by 2 per cent digitonin. Rhodopsin was an inevitable contaminant in most methods of extraction, but could be reduced to about 10 per cent of the absorption due to iodopsin by extraction of unhardened retinas with 4 per cent Merck's saponin in (3/4) saturated magnesium sulfate for about 1 hour. 4. The rate of bleaching of iodopsin was found to be first order and linear with respect to energy. 5. The bleaching effectiveness spectrum of iodopsin was determined with the aid of color filters of known energy transmission, and shows a maximum at 560 mmicro in the yellow green with a lower plateau in the blue. The spectrum is in good agreement with the sensitivity of the human cones except for the wavelength of maximum bleaching effectiveness. The maximum sensitivity of the human cones is found at 540 mmicro. 6. Previous reports of changes in pH and inorganic phosphate level of retinas due to bleaching could not be confirmed. PMID- 19873463 TI - PHOTOLYTIC LIPIDS FROM VISUAL PIGMENTS. AB - A method is described for the preservation of iodopsin, the labile photopigment of daylight vision, by freeze drying in vacuo. The lipids released by the action of light on rhodopsin and iodopsin are found to be similar and to possess a labile absorption spectrum in chloroform, with a rising peak at about 390 mmicro and a declining peak in the region of 470 mmicro. After the change is complete the absorption spectrum resembles closely that of retinene. PMID- 19873464 TI - POTASSIUM ACCUMULATION IN THE PROXIMAL CONVOLUTED TUBULES OF THE FROG'S KIDNEY. AB - 1. In a manner similar to that of the sartorius muscle, the isolated kidney of the frog can accumulate K against a gradient to upwards of three times its normal concentration. 2. The K-accumulating region is identified as the proximal tubule, which in the isolated tissue immersed over 24 hours in the cold (2-3 degrees C.) amounts to about 90 per cent of the nephron minus the glomerulus. In the fresh tissue it constitutes about 70 per cent. The cells of the proximal tubule are impermeable to Na, but freely permeable to K and Cl. 3. The distal tubule in the isolated kidney does not accumulate K over the external concentration. The cells are permeable to Na which they actively extrude. This extrusion of Na goes parallel with a loss of osmotically associated water amounting to about 15 per cent of the weight of the fresh kidney, but varying somewhat with the conditions. 4. The accumulation of K in the proximal tubules is in accordance with the equations established for the sartorius muscle, and, as theoretically expected, there is no volume increase (but rather a small decrease) with the large accumulations, when the external Na concentration is maintained throughout. 5. With K accumulation in isotonic mixtures large volume changes occur as K is progressively substituted for Na. Over the range of external K concentration of 10 to 100 mM per litre the weight of the whole kidney changes to 2.5 times and the water of the cells of the proximal tubules increases to over four times. Up to an external K value of 90 mM per litre the mean weight of the kidney shows a linear relation when plotted against the reciprocal of the Na concentration plus the small glucose and Ca concentration. This relation is interpreted theoretically. 6. The effect of cyanide in the isotonic mixtures is to prevent the contraction of the distal tubules and to cause swelling of the same. It does not affect the volume, volume changes, or differential permeability of the proximal tubule. At the same time the membranes of the proximal tubule cells lose their characteristic permeability at a lower level of distension in the presence of cyanide. 7. The mean Na ratio for the kidney after 24 hours' immersion in the cold is 0.26 +/- 0.014 (giving standard deviation of mean). The ratio is defined as See PDF for Equation. For the fresh kidney the mean ratio is 0.39 +/- 0.006. 8. The mean inulin ratio (28 observed in the cold) is 0.23 +/- 0.012 and the same value for 10 observed at room temperature. At room temperature-2 hour immersion the ratio is increased by cyanide to a mean of 0.32 +/- 0.028, but only a slight increase is caused by cyanide in the cold. 9. The mean hemoglobin ratio after 24 hours' immersion in the cold is 0.17 +/- 0.004 and is unaffected by cyanide. PMID- 19873465 TI - ANOXIA AND BRIGHTNESS DISCRIMINATION. AB - 1. Brightness discrimination has been studied with individuals breathing oxygen concentrations corresponding to 7 altitudes between sea level and 17,000 feet. The brightnesses were 0.1, 0.01, and 0.001 millilambert involving only daylight (cone) vision. 2. At these light intensities, brightness discrimination begins to deteriorate at fairly low altitudes. The deterioration is obvious at 8,000 feet, and becomes marked at 15,000 feet, where at low brightness, the contrast must be increased 100 per cent over the sea level value before it can be recognized. 3. The impairment of brightness discrimination with increase in altitude is greater at higher altitudes than at lower. The impairment starts slowly and becomes increasingly rapid the higher the altitude. 4. Impairment of brightness discrimination varies inversely with the light intensity. It is most evident under the lowest light intensities studied, but shows in all of them. However, it decreases in such a way that the deterioration is negligible in full daylight and sunlight. 5. The thresholds of night (rod) vision and day (cone) vision are equally affected by anoxia. 6. The quantitative form of the relation between brightness discrimination DeltaI/I and the prevailing brightness I remains the same at all oxygen concentrations. The curve merely shifts along the log I axis, and the extent of the shift indicates the visual deterioration. 7. The data are described in terms of retinal chemistry. Since anoxia causes only a shift in log I it is shown that the photochemical receptor system cannot be affected. Instead the conversion of photochemical change into visual function is impaired in such a way that the conversion factor varies as the fourth power of the arterial oxygen saturation. PMID- 19873466 TI - THE POTENTIOMETRIC ANALYSIS OF MEMBRANE STRUCTURE AND ITS APPLICATION TO LIVING ANIMAL MEMBRANES. AB - 1. The electromotive forces which arise, if two electrolyte solutions are separated from each other by a layer of any kind, are discussed. A general equation is derived comprising the known equations for diffusion, partition, and membrane (Donnan) potentials as special cases. 2. A method is proposed to analyse membranes potentiometrically with respect to their cation or anion selectivity, their dissolving power for ions, and their influence on ion mobility (migration velocity). 3. The possibility of analysing a membrane composed of several layers of different permeability is discussed. 4. The investigation of the skin of the belly of Rana temporaria leads to the following results. It is composed of at least four layers of different permeability, one of which is specifically permeable to H ions and is very likely identical with the "basal membrane" situated between the stratum germinativum and the corium. The major part of the resting potential of the skin is located across this membrane and is due to the difference of H(+) concentrations on both sides of the membrane. 5. Experiments on muscle show that the sarcolemma is specifically permeable to H ions. The injury potential of the muscle is attributed to the difference of H(+) concentration inside and outside the fibre. PMID- 19873467 TI - ISOLATION OF HEXOKINASE FROM BAKER'S YEAST. AB - 1. A method is described for the isolation of hexokinase from baker's yeast. The method is based mainly on fractionation with alcohol and results See PDF for Structure in a 30-fold increase in specific activity. The final product could be crystallized from ammonium sulfate without change in specific activity. 2. The enzyme catalyzes a transfer of phosphate from adenosinetriphosphate to glucose, fructose, or mannose, the relative rates with these three sugars being 1:1.4:0.3. 3. With glucose as substrate, the turnover number for the crystalline enzyme is 13,000 moles of substrate per 10(5) gm. of protein per minute at 30 degrees and pH 7.5. The temperature coefficient (Q(10 degrees )) between 0 and 30 degrees is 1.9. 4. Magnesium ions are necessary for the activity, the dissociation constant for the Mg(++) -protein complex being 2.6 x 10(-3). Fluoride in concentrations as high as 0.125 M has no inhibitory effect on the enzyme when the Mg(++) and orthophosphate concentrations are 6.5 x 10(-3)M and 1 x 10(-3)M, respectively. 5. The crystalline enzyme shows a loss in activity when highly diluted. This loss in activity can be prevented by diluting in the presence of small amounts of other proteins. Of the various protective proteins tested, insulin was the most effective, providing complete protection in a concentration of 6 micrograms per cc.; with serum albumin, a concentration of 60 micrograms per cc. was necessary. Thiol compounds (cysteine, glutathione) exerted no protective action. 6. The inactivation of the crystalline enzyme on incubation with trypsin can be prevented to a marked degree by the presence of glucose. The instability of crude preparations of yeast hexokinase may be attributed to the presence of proteolytic enzymes, since glucose or fructose has a remarkable protective effect on such preparations. PMID- 19873468 TI - CRYSTALLINE HEXOKINASE (HETEROPHOSPHATESE) : METHOD OF ISOLATION AND PROPERTIES. AB - 1. Crystalline hexokinase has been isolated from baker's yeast. 2. Crystalline hexokinase is a protein of albumin type of a molecular weight of 96,000. Its isoelectric point is at about pH 4.8. 3. The method of isolation consists in separating the proteins of an aqueous extract of toluene-treated yeast by means of fractional precipitation with ammonium sulfate and with alcohol. 4. The procedure involves also the separation of several crystalline proteins, including one yellow crystalline protein, which do not possess hexokinase activity. The biological and the physicochemical properties of these proteins are still under investigation. 5. The crystallization of hexokinase proceeds at about 5 degrees C. in the presence of ammonium sulfate and dilute phosphate buffer pH 7.0. 6. Crystalline hexokinase becomes relatively pure after 2 or 3 recrystallizations as tested by solubility, sedimentation in the ultracentrifuge, and electrophoresis. The enzymatic activity remains constant on repeated crystallization. 7. The enzymatic activity is associated with the protein nature of the material. Inactivation is accompanied by denaturation of the protein. 8. Crystalline hexokinase is relatively stable when stored in the form of crystalline filter cake. Solutions of hexokinase in dilute buffers are most stable at pH 5.0. 9. Crystalline hexokinase requires the presence of magnesium ions for its catalytic activity. PMID- 19873469 TI - SOME PROPERTIES OF THE YEAST YELLOW PROTEIN. AB - The yeast yellow protein contains two prosthetic groups, one of which is undoubtedly a flavin. The nature of the other is unknown, though some of its properties are described. No catalytic function for this protein has as yet been found. PMID- 19873470 TI - CULTURE CONDITIONS AND THE DEVELOPMENT OF THE PHOTOSYNTHETIC MECHANISM : III. INFLUENCE OF LIGHT INTENSITY ON CELLULAR CHARACTERISTICS OF CHLORELLA. AB - 1. Chlorella pyrenoidosa has been grown in a continuous-culture apparatus under various light intensities provided by incandescent lamps, other conditions of culture being maintained constant. The harvested cells were analyzed for cell number, dry weight, nitrogen, and chlorophyll per unit cell volume. 2. Cell nitrogen and cell volume are parallel measures of cellular material over the range of light intensity studied. 3. The dry weight per cell volume increases slowly with light intensity, showing about a 20 per cent variation. 4. Chlorophyll concentration and cell number show a concomitant decrease with increasing light intensity, varying in such a way that there are always about the same number of chlorophyll molecules per cell. It is considered that this phenomenon has bearing on the interpretation of data which has led to the theory of the photosynthetic unit. PMID- 19873471 TI - CULTURE CONDITIONS AND THE DEVELOPMENT OF THE PHOTOSYNTHETIC MECHANISM : IV. INFLUENCE OF LIGHT INTENSITY ON PHOTOSYNTHETIC CHARACTERISTICS OF CHLORELLA. AB - 1. Chlorella pyrenoidosa has been grown in a continuous-culture apparatus under various light intensities provided by incandescent lamps, other conditions of culture being maintained constant. Light intensity curves for cells immersed in the No. 11 Warburg buffer and in Knop's solution + 4.4 per cent CO(2) at a saturating light intensity were determined as characteristics of the photosynthetic mechanism. These characteristics were referred to the centrifuged cell volume as an index of quantity of cellular material. 2. Cells grown at intensities in the range of about 35 f.-c. develop a capacity for a high rate of photosynthesis (c.mm. O(2)/hour/c.mm. cells). At culture intensities above or below this range the cells produced have a lower capacity for photosynthesis. A similar effect is observed for rate of photosynthesis per unit dry weight or rate per unit cell nitrogen. 3. The rate of photosynthesis per cell or rate per unit chlorophyll shows no maximum at any light intensity of culture but increases continuously throughout the range of light intensities studied. 4. Maximum rate of growth is attained at a light intensity of about 100 f.-c. The hypothesis is advanced that at culture intensities above that needed to give maximum rate of growth (100 f.-c.) a mechanism is developed which opposes the photosynthetic process and removes the photosynthetic products. 5. The low capacity for photosynthesis shown by cells grown at culture intensities below 35 f.-c. finds no immediate explanation. 6. The shape of the light intensity curve is markedly affected by the light intensity at which the cells have been cultured. Cells grown at lower intensities give light intensity curves approaching the Blackman type with a short transitional region between light limitation and light saturation. PMID- 19873472 TI - THE PENETRATION OF VESICANT VAPORS INTO HUMAN SKIN. AB - Analytical methods which are accurate to about 1 per cent have been developed for the determination of small amounts (ca. 500 gamma) of bis(beta-chloroethyl) sulfide (H), ethyl-bis(beta-chloroethyl)amine (EBA), tris(beta-chloroethyl)amine (TBA), beta-chloroethyl-benzylsulfide (benzyl-H), and beta-chloroethyl ethylsulfide (ethyl-H). The determinations are made by micro titration of the HCl liberated upon complete hydrolysis of the vesicants. A description is given of an apparatus suitable for applying vapors of vesicants to unit areas of skin. A very precise and reproducible micropipetting technique is described for the introduction of the vesicants into the penetration apparatus. By means of this penetration apparatus studies have been made of several factors which may influence the rate at which vesicant vapors penetrate into skin. Model experiments have been performed in which H was allowed to vaporize and the vapor was absorbed on a surface such as that of diethylene glycol or vaseline. It has been found that if the surface of liquid H is increased by spreading the agent on filter paper, the rate of evaporation is markedly increased. Furthermore, if the vapor is agitated by means of a magnetically driven fan, the rate of absorption by diethylene glycol is greatly accelerated. With vaseline as the absorbing surface it has been found that the area of the absorbing surface has an effect on the rate of absorption of H vapor. More H is absorbed by vaseline spread on filter paper to give a rough surface than is absorbed by a smooth film of vaseline. Measurements of the rate of penetration into human skin of H, EBA, TBA, benzyl-H, and ethyl-H vapors have been performed at 21-23 degrees C. and 30-31 degrees C. by means of the penetration apparatus described in this paper. The measurements were carred out on human volunteers under conditions of controlled temperature and humidity. When human skin is exposed to air saturated with H vapor, the H penetrates the skin of the forearm at a rate of about 1.4 gamma per cm.(2) per minute (temperature 21-23 degrees C.; relative humidity 46 per cent). This value was found to hold in experiments in which H vapor was applied for 3 to 30 minute intervals, thus indicating that the permeability of the skin to H vapor is not altered during a 30 minute exposure. Agitation of the H vapor by fanning did not result in any measurable increase in the rate of penetration. Two of the volunteers were Negroes; the permeability of their skin to H vapor did not differ appreciably from that found for the other subjects. When human skin is exposed to air saturated with EBA vapor, the vesicant penetrates at the rate of 2.8 gamma per cm.(2) per minute (temperature 22 degrees C., relative humidity 50 to 52 per cent). The amount of EBA penetrated is linear with exposure time for exposure periods of 5 to 20 minutes. Under similar conditions, it was found that TBA penetrates at a rate of about 0.18 gamma per cm.(2) per minute (temperature 22-23 degrees C.; relative humidity 45 to 48 per cent). This value was found to hold in experiments in which TBA vapor was applied for 30 to 60 minute intervals. The amount of TBA penetrated is linear with exposure time. In the case of benzyl-H, a linear relationship between the amount lost from the penetration cup and exposure time was also observed but the plot did not pass through the origin. It is suggested that this anomaly is due to retention on the skin surface of an appreciable quantity of benzyl-H as a result of rapid physical adsorption or chemical combination with a constituent of the skin. The rate of penetration of benzyl-H may be calculated from the slope of the plot and is found to be 0.35 gamma per cm.(2) per minute (temperature 22 degrees C., relative humidity 55 to 60 per cent). The results with ethyl-H showed great variation among individual subjects and no satisfactory value for the rate of penetration can be given as yet. Measurements were also made of the rate of penetration of H, EBA, and TBA vapors at 30-31 degrees C. (relative humidity 47 to 49 per cent). At this temperature, a linear relationship was observed between the amount penetrated and the time of exposure. H vapor penetrated at a rate of 2.7 gamma per cm.(2) per minute, EBA vapor at 5.1 gamma per cm.(2) per minute, and TBA vapor at 0.29 gamma per cm.(2) per minute. Three of the subjects in the EBA measurements were Negroes. The permeability of their skin to EBA vapor did not differ from that found for the white subjects. Despite this fact, their skin failed to vesicate after an exposure period twice that which caused 50 per cent vesication in the white subjects. Calculation of the precision of the data showed that the average deviation, standard deviation, and standard error were not appreciably different for the data obtained with human subjects as compared with data for control experiments in which human skin was not involved. Consequently, no significant differences in the rate of penetration into the skin of individual subjects can be discerned from the data presented in this communication. The increase in the rate of penetration of H, EBA, and TBA vapors from 21-23 degrees C. to 30-31 degrees C. is approximately proportional to the increase in volatility of each agent. These results indicate that at the same gas concentration in milligrams per liter, H, EBA, and TBA vapors would all penetrate at about the same rate. The data presented above permit a determination of the approximate amount of each vesicant which must penetrate to cause vesication in about 50 per cent of the exposed sites. This amount has been designated by the symbol V(50). The V(50) for H and TBA at 21-23 degrees C. is the same, being about 6gamma; at 30-31 degrees C., the V(50) is 4 to 5 gamma. On the other hand, the V(50) for EBA at 22 degrees C. and 30-31 degrees C. is about 26 to 28 gamma. Thus, per gamma penetrated, H and TBA vapors are about equally effective in producing vesication while EBA vapor is only (1/5) to (1/8) as effective. PMID- 19873473 TI - THE PORPHYRIN REQUIREMENTS OF HAEMOPHILUS INFLUENZAE AND SOME FUNCTIONS OF THE VINYL AND PROPIONIC ACID SIDE CHAINS OF HEME. AB - 1. Iron protoporphyrin IX was required for the growth of H. influenzae. It could be replaced by protoporphyrin IX. When grown on protoporphyrin evidence was obtained for the presence of Fe porphyrin in the organism. It was concluded that the organism could insert iron into the protoporphyrin ring. 2. In the smooth strains, other porphyrins containing no iron such as deutero-, hemato-, meso-, and coproporphyrins could not replace protoporphyrin for growth. Since protoporphyrin has two vinyl groups which other porphyrins lack, it was concluded that the two vinyl groups were essential for growth. 3. When porphyrins lacking vinyl groups were converted chemically into iron porphyrins and then supplied to the organisms it was found that these iron porphyrins supported growth. It was concluded that the "smooth" organisms were able to insert iron only into the porphyrin containing the vinyl groups; i.e., protoporphyrin. One function of the vinyl groups then was to permit iron to be inserted biologically into the porphyrin ring. 4. An anomalous behavior in the rough Turner strain was observed and discussed. This organism was able to insert iron into mesoporphyrin at low concentrations but was inhibited by this compound at higher concentrations. In all other reactions with the porphyrins this rough strain behaved in the same was as did the smooth strains. 5. All strains which were grown on iron porphyrins lacking vinyl groups could not reduce nitrate to nitrite. When grown on protoporphyrin or Fe protoporphyrin reduction of nitrate occurred. It was concluded that the nitrate-reducing mechanism required the presence of the vinyl groups either for its formation or function. 6. The porphyrins lacking iron and lacking vinyl groups inhibited the growth of H. influenzae on Fe protoporphyrin. The inhibition between a porphyrin and Fe protoporphyrin was a competitive one. It was suggested that the porphyrin inhibited the growth-promoting properties of Fe protoporphyrin by attaching on to a particular apoprotein, thus preventing the formation of a heme catalyst. Likewise, competition between two growth-promoting Fe porphyrins for apoenzymes could be shown to occur. 7. Protoporphyrin and Fe protoporphyrin supported growth. When their propionic acid side chains were esterified they no longer supported growth. It was suggested that the esterified carboxyl groups could not attach to the specific apoproteins to form the heme enzymes and so could not act to support growth. For the same reason the inhibitory action of porphyrins lacking vinyl groups could be prevented by esterifying their propionic acid groups. PMID- 19873474 TI - HEMOLYTIC SYSTEMS CONTAINING ANIONIC DETERGENTS. AB - 1. The members of the homologous series of anionic detergents, the sodium salts of the sulfated straight chain alcohols with the general formula C(n)H(2n+1).SO(3).Na, are hemolytic, the lytic activity being at a maximum when the compound contains 14 carbon atoms in the chain. In systems in which lysis is comparatively rapid, the hemolytic effect increases with increasing pH, but in systems containing quantities of lysin near the asymptotic concentrations the pH dependence of the activity is reversed. The effect of temperature is principally one on the velocity constant of the lytic reaction, with smaller effects on the position of the asymptotes of the time-dilution curves and on their shape. 2. The quantities of the detergents which produce disk-sphere transformations are approximately one-tenth of those required to produce complete hemolysis. In most cases, the shape change occurs when there are too few detergent molecules present to cover the red cell surfaces with a monolayer. 3. Plasma inhibits the hemolytic action of these detergents, and, in the quantities in which they occur in plasma, lecithin, serum globulin, cholesterol, and serum albumin, produce inhibitory effects which increase in that order in systems containing the C-14 sulfate. It can be inferred from these inhibitory effects that the anionic detergents can form compounds or complexes with lipid, lipoprotein, and protein components of the red cell ultrastructure. PMID- 19873475 TI - FURTHER OBSERVATIONS ON THE MECHANISM OF PHAGE ACTION. AB - 1. The reaction between an antistaphlycoccal phage and the homologous bacterium has been studied, applying the following experimental technics not used in earlier work reported from this laboratory: (a) Both the activity assay and the plaque count were utilized for determining [phage]. (b) Sampling was done at short intervals; i.e., every 0.1 hour. (c) Extracellular phage was separated from the cell-bound fraction by a filtration procedure permitting passage of < 95 per cent of free phage. 2. Using these technics, the reaction was followed: (a) with pH maintained at 6.10 and temperature at 28 degrees C. to slow the process; (b) with pH maintained at 7.2 and temperature at 36 degrees C. 3. In addition separate experiments were performed on the sorption of phage by bacteria at 30 degrees , 23 degrees , and 0 degrees C. 4. At pH 6.10 and 28 degrees C. the phage bacterium reaction proceeds in the following sequence: (a) There is an initial phase of rapid logarithmic sorption of phage to susceptible cells, during which the total phage activity and the plaque numbers in the mixtures remain constant. (b) When 90 per cent of the phage has been bound, there is a sudden very rapid increase in phage activity not paralleled by an increase in plaques; i.e., phage is formed intracellularly, but is retained within cellular confines. (c) After a further drop in the extracellular phage fraction there occurs a pronounced increase in the total phage plaque count not accompanied by any increase in total activity. This indicates a redistribution of phage formed intracellularly. At the same time there is a rise in the extracellular phage curves (both activity and plaque). (d) With the concentrations of phage and bacteria used in the experiment carried out at pH 6.1 and 28 degrees C. there are two further increments in [phage](act.) before massive lysis begins. (e) During terminal lysis there are sharp rises in the curves for [total phage](plaq.), [extracellular phage](act.), and [extracellular phage](plaq.). (f) Immediately after the completion of lysis there is a considerable disparity between measurements of total phage and extracellular phage, probably occasioned by the association of phage molecules with cellular debris, the latter being of sufficient size to be removed by the super-cel filters. 5. At pH 7.2 and 36 degrees C. the steps in the phage production curve as determined by activity assay and plaque count are much less prominent than those observed at pH 6.1 and 28 degrees C. However, the plateaus described by Ellis and Delbruck (10) for B. coli and coli phage can be detected also in the present case if frequent samples are taken. 6. The sorption experiments show a significant rise in the rate of phage uptake with increase in temperature, again supporting the view that the reaction involves more than a purely physical adsorption. 7. Delbruck's objections to: (a) the use of the activity assay for determining [total phage] in mixtures of phage and susceptible cells, and (b), to the demonstration of phage precursor in "activated" bacteria have been analyzed. 8. The activity assay has been demonstrated to be an accurate procedure for determining either phage free in solution or phage bound to living susceptible cells, under the conditions of the experiments reported here and in earlier work. 9. The titration values obtained in the experiments designed to exhibit intracellular phage precursor are not the result of artifacts as Delbruck has inferred. The data can be interpreted in terms of the precursor theory, although other explanations are not ruled out. PMID- 19873476 TI - FRACTIONATION OF THE EYE PIGMENTS OF DROSOPHILA MELANOGASTER. AB - Eye pigments of normal and mutant types of D. melanogaster have been extracted with water and fractionated by chromatographic adsorption on powdered talc. Spectra of all the fractions obtainable in solution have been measured and the general chemical behavior of the pigments is described. Two chemically distinct groups of pigments are found, to be identified with the earlier designated red and brown components. The red component in the wild-type eye contains three well defined pigments, two of them capable of further subdivision so that the total number of fractions obtained is five. There is also present a brown component pigment which could not be treated quantitatively by the methods employed. All members of the wild-type red component are found in cinnabar eyes, unaccompanied by the brown component. Conversely, brown eyes contain a pigment indistinguishable from the wild-type brown component, virtually alone. In sepia eyes, one red component and two brown component pigments can be distinguished, all three pigments differing from those of wild-type eyes. Pigments apparently identical with those found in wild-type melanogaster eyes have also been found in D. virilis. PMID- 19873477 TI - NATURE OF THE ACTION CURRENT IN NITELLA : VI. SIMPLE AND COMPLEX ACTION PATTERNS. AB - The experiments indicate that the protoplasm of Nitella consists of an aqueous layer W with an outer non-aqueous surface layer X and an inner non-aqueous surface layer Y. The potential at Y is measured by the magnitude of the action curve and the potential at X by the distance from the top of the action curve to the zero line. These potentials appear to be due chiefly to diffusion potentials caused by the activity gradients of KCl across the non-aqueous layers X and Y. The relative mobilities of K(+) and Cl(-) in X and in Y can be computed and an estimate of the activity of KCl in W can be made. In the complete resting state the mobilities of K(+) and Cl(-) in X are not very different from those in Y. The action curve is due to changes in Y which suddenly becomes very permeable, allowing potassium to move from the sap across Y into W, and thus losing its potential. A gradual loss may be due to changes in ionic mobility in Y. When recovery is incomplete and Y has not yet regained its normal potential a stimulus may cause a loss of the potential at Y giving an action curve of small magnitude. The magnitude may vary in successive action curves giving what is called a complex pattern in contrast to the simple pattern observed when recovery is complete and all the action curves are alike. Complex patterns occur chiefly in cells treated with reagents. Untreated cells usually give simple patterns. A variety of complex action patterns is discussed. It is evident that the cells of Nitella show much more variation than such highly specialized cells as muscle and nerve which give stereotyped responses. In some cases it may be doubtful whether the all-or-none law holds. PMID- 19873478 TI - EFFECTS OF CERTAIN LIMITING CONDITIONS ON THE SYNTHESIS OF B VITAMINS BY YEAST. AB - In yeast crops which were grown in the presence of various inhibitors, there was considerable variation in content of the various B vitamins. A higher degree of parallelism in variation in content was found to exist between thiamine and niacin than between any other pair of vitamins; this has been interpreted as indicating that the predominant functions of these two vitamins are their established roles in fermentation. Values for inositol indicate that it may be involved in fermentation processes, but this is not the case for other members of the B complex. Biotin appears to be unique since in no case did the biotin content of yeast grown in the presence of an inhibitor fall below that of the control yeast. There was some evidence of synthesis of biotin, or a material with biotin activity, in the presence of certain inhibitors, the most striking instance being with sulfaguanidine. An exogenous supply of biotin was essential for extensive proliferation of F. B. yeast, and yeast grown in a medium to which biotin was the only added vitamin contained the B vitamins in amounts very similar to those found in the control yeast, the most marked differences being in increased vitamin B(6) and p-aminobenzoic acid contents. In the absence of biotin, significant amounts of all of the B vitamins except biotin were synthesized, both in the presence and absence of certain other members of the B complex. The addition of thiamine, pyridoxine, inositol, and beta-alanine to the culture medium caused a reduction in the amounts of vitamin B(6) and p aminobenzoic acid synthesized. F. B. yeast was able to grow in a xylose medium only when certain of the B vitamins were present, and even then growth was limited. Evidence was obtained for some synthesis of all of the vitamins investigated except biotin and vitamin B(6). The most significant differences in vitamin content between galac yeast and the parent F. B. strain were in folic acid and vitamin B(6), the former being considerably reduced in amount, the latter being increased. PMID- 19873479 TI - THE PYRUVATE METABOLISM OF SEA URCHIN EGGS DURING THE PROCESS OF CELL DIVISION. AB - The eggs of Arbacia and starfish contained about 70 and 25 micrograms of pyruvate per gm. of dry cells respectively. Arbacia eggs utilized added pyruvate, although the O(2) uptake did not increase. On fertilization the utilization of pyruvate increased sevenfold. This pyruvate seems to be metabolized, as in other cells, with diphosphothiamine as coenzyme. The diphosphothiamine content of fertilized and non-fertilized eggs was about 16 micrograms; that of sperm, 30 micrograms. Penetration of sperm into the egg and fertilization with cell division to the pluteus stage did not bring forth appearance of succino-dehydrogenase. The possible mechanism of fertilization and cell division is discussed. PMID- 19873480 TI - THE NUCLEOPROTAMINE OF TROUT SPERM. AB - The nucleoprotamine of trout sperm can be extracted completely with 1 M sodium chloride. On reducing the salt concentration to 0.14 M, physiological saline, the nucleoprotamine precipitates in long, fibrous strands. When the nucleoprotamine, dissolved in M NaCl, is dialyzed all the protamine diffuses through the membrane leaving behind highly polymerized, protein-free desoxyribose nucleic acid. The nucleoprotamine constitutes 91 per cent of the lipid-free mass of the sperm nucleus. While nucleoprotamine is being extracted by M NaCl a stage is reached at which the sperm chromosomes are clearly visible. PMID- 19873481 TI - CHROMOSIN, A DESOXYRIBOSE NUCLEOPROTEIN COMPLEX OF THE CELL NUCLEUS. AB - A desoxyribose nucleoprotein complex, which we have referred to as a chromosin, has been prepared from a great variety of cells, mainly animal but also plant and bacterial. A chromosin is derived from the cell nucleus. In the course of preparation precautions have been taken to prevent contamination by cytoplasmic constituents. To assure the nuclear origin of all components of chromosin, nuclei have in several instances been isolated before extraction was begun. Because of the precautions taken, chromosins do not contain detectable quantities of ribose nucleoproteins; but, incidentally, extraction of ribose nucleoproteins, free of desoxyribose compounds, has also been described in this paper. A typical chromosin contains 3 components: desoxyribose nucleic acid, histone, and non histone protein. The nucleic acid, being highly polymerized, is exceedingly viscous when dissolved and fibrous when precipitated. Histone and non-histone protein differ from each other in a number of ways, of which one of the most definite is that whereas a histone contains no more than traces of tryptophane, the non-histone protein of chromosin contains nearly 1 per cent of tryptophane. In neutral physiological saline both proteins can combine with nucleic acid. With the isolation of chromosins from so many different kinds of cells, it can now be seen that (contrary to the view expressed by Kossel) histones are present in most animal cells and at least in some plant and bacterial cells. Chromosin prepared from the Type III pneumococcus is active in transforming the type of a pneumococcus culture. It has been pointed out that it is not yet known whether or not protein is a necessary constituent of the transforming agent. To extract chromosin from a cell M NaCl is used. When dissolved in M NaCl the nucleic acid and histone components of a chromosin are to a considerable extent dissociated. They are not dissociated when the chromosin is dissolved in 0.02 M NaCl, but in this medium a partial depolymerization of the nucleic acid occurs. A chromosin should certainly not be considered to be a definite chemical compound. It is a complex extracted from chromatin, which is itself a complicated nuclear structure. And in the course of extraction, it need hardly be said, the structure of chromatin has been considerably changed. To avoid complications it has been considered an advantage in this work to begin with isolated nuclei, and it would clearly be a further simplification to begin chemical procedures only after the chromosomes themselves have been isolated. This is now being accomplished, and it is found that the methods described in this paper are of value in learning how the substances present in a chromosin are put together in a chromosome. PMID- 19873482 TI - THE ACTIVATION OF PLASMINOGEN BY CHLOROFORM. AB - 1. Treatment of serum with chloroform results in immediate inactivation of the protease inhibitor present. 2. Following a lag period of less than one to several days, proteolytic activity begins to appear in the chloroform-treated serum. Activity increases over a period of several days and then begins to diminish gradually. At about the time when the spontaneous activity begins to diminish, the total proteolytic activity of the preparation also begins to fall until finally the two curves coincide. 3. Chloroform treatment of serum appears to result in some destruction of plasminogen because not only is the total proteolytic activity of the chloroform-treated serum less than that of the serum before chloroform treatment, but the maximum spontaneous activity that develops is only about one-half the total proteolytic activity of serum before treatment with chloroform. 4. The spontaneous activation of plasminogen which occurs following removal of inhibitor appears to be autocatalytic in nature. 5. In the presence of active plasmin, both plasmin and plasminogen are destroyed. PMID- 19873483 TI - STUDIES OF ALUMINUM SOAPS : IX. ELECTRON MICROSCOPE VIEW OF LYOPHILIZED ALUMINUM LAURATE. PMID- 19873484 TI - OBSERVATIONS ON THE RESPIRATION OF TRYPANOSOMA CRUZI IN CULTURE. AB - 1. The oxygen consumption of cultural forms of Trypanosoma cruzi decreases in intensity with increasing age of the cultures; no correlation with any other factor studied could be established. 2. The respiratory quotient was high for the first 10 days, i.e. as long as the population increased; with the onset of a decline in numbers, the R.Q. began to drop. It is believed that the flagellates consume in the beginning predominantly sugar and later predominantly protein. Observations on the pH of the cultures bear out this view. 3. The oxygen consumption was independent of the oxygen tension over a wide range of tensions. 4. The oxygen consumption increased in the temperature range 13 degrees to 40 degrees C., while a temperature of 44 degrees C. proved to be lethal. Upon application of Arrhenius' equation, two straight lines, intersecting at about 28 degrees C., resulted. The micro values were 23,980 and 5275 for the lower and higher temperature range respectively. 5. Of the oxidase inhibitors tested, strong inhibition of the oxygen consumption was achieved with azide, cyanide, and hydrogen sulfide. Pyrophosphate had no influence at all. There is some probability that cytochrome oxidase is the chief oxidase present. 6. The strongest inhibitory influence due to dehydrogenase inhibitors was observed with propyl carbamate and high concentrations of ethyl carbamate. 7. A small fraction of the oxygen consumption, about 10 per cent, may be due to substances with sulfhydryl groups, as indicated by a slight but distinct inhibition due to dilute iodoacetate and to arsenite. PMID- 19873485 TI - CRYSTALLIZATION OF PEPSIN FROM ALCOHOL. AB - 1. Pepsin is soluble in 65 per cent alcohol and may be readily crystallized from 20 per cent alcohol. The crystals appear as needles or plates which may be transformed into the usual hexagonal bipyramids by recrystallization from water. The different crystals are probably two crystalline forms of the same chemical substance. 2. The enzyme is quite stable in 20 per cent alcohol at pH 2.0 but is inactivated by high concentrations of alcohol. 3. The enzyme is stable for several hours in 65 per cent alcohol at pH 4.0 to 5.0 but is rapidly inactivated in more acid solution. 4. No increase in activity could be noted after treatment with hydrogen peroxide. 5. No proteolytic activity either before or after treatment with hydrogen peroxide could be found in trichloracetic acid filtrates, butyl alcohol extracts of pepsin preparations, or oxidized phenylhydrazine solutions. PMID- 19873486 TI - REACTION OF ENZYMES AND PROTEINS WITH MUSTARD GAS (BIS(beta-CHLOROETHYL)SULFIDE). AB - 1. The rate of reaction of mustard gas (H) with thirteen proteins has been determined. The extreme variation in reaction rates is about 100:1. 2. No qualitative difference in the results was observed when the treatment with H was carried out by the Dixon or stirring methods. 3. The kinetics have been analyzed and a bimolecular equation derived which fits the facts. 4. The carboxyl groups of all proteins reacted when the reaction with H was carried out at pH 6.0 in M/25 acetate buffer. In most cases the number of carboxyl groups covered was approximately equal to the number of H residues bound. 5. The amino groups of proteins failed to react with the possible exception of yeast hexokinase. 6. The color obtained when proteins were mixed with Folin's phenol reagent at pH 8.0 decreased as the protein was treated with H. The color returned on treatment of the H-protein with alkali and many of the combined H groups were hydrolyzed. Similar results were observed when a concentrated glycyltyrosine solution was treated with H. PMID- 19873487 TI - MOLECULAR ASSOCIATION OF HEMOCYANIN PRODUCED BY X-RAYS AS OBSERVED IN THE ULTRACENTRIFUGE. AB - 1. When normal, monodisperse hemocyanin (60.5S) from Limulus Rolyphemus was irradiated in neutral buffer with x-rays, several new, more rapidly sedimenting ultracentrifugal components (86S, 107S, 122S) were produced, with a corresponding loss in the amount of the unaffected protein. The amount of the effect was roughly proportional to the amount of irradiation. 2. The new resolvable components apparently represented an association of the primary particles into aggregates of 2, 3, and 4 primary particles respectively. 3. The proportional amount of hemocyanin affected decreased almost to the vanishing point as the concentration of the protein was raised to high levels. 4. The absolute effect, i.e. the total number of particles affected in a given volume, increased with the concentration of hemocyanin, at least for concentrations below 15 per cent. 5. The presence of 33 per cent horse serum during irradiation inhibited the effect on the hemocyanin almost completely, with hemocyanin concentrations of both 0.8 and 14 per cent. 6. The presence of 2.8 per cent egg albumin during irradiation lowered the effect by about 70 per cent in the case of dilute preparations (0.8 per cent hemocyanin), but by only about 25 per cent in the case of 14 per cent solutions. 7. A lowering of the solution's oxygen tension during irradiation enhanced the effect, almost doubling it in some cases. 8. The probable theoretical significance of these and other observations are discussed in the text. PMID- 19873488 TI - SALTANT PRODUCTION BY WAVE LENGTHS OF VISIBLE AND LONG ULTRAVIOLET MONOCHROMATIC IRRADIATION, AND A COMPARISON WITH SALTANTS PRODUCED BY SHORT WAVE LENGTHS OF MONOCHROMATIC ULTRAVIOLET IRRADIATION IN THE FUNGUS CHAETOMIUM GLOBOSUM. AB - 1. Saltants have been produced in the fungus Chaetomium globosum by longer wave lengths than previously reported-by 365 mmicro and by a visible line 404 mmicro. 2. Absence at these wave lengths of the K saltant, which is so abundant at short wave lengths, is marked. 3. Ratio of percentage irradiated spores germinating to control spores germinating decreases from 83 per cent at 265 mmicro, a short ultraviolet wave length, to 57 per cent at 404 mmicro, a visible violet wave length. PMID- 19873489 TI - OXIDATIVE ASSIMILATION IN RELATION TO PHOTOSYNTHESIS IN CHLORELLA. AB - 1. An oxidative assimilation of acetic add and glucose in darkness has been demonstrated in the green alga, Chlorella pyrenoidosa. From manometric experiments it has been shown that 1 mol (CH(2)O) per mol acetic add and 5 mols (CH(2)O) per mol glucose are produced. 2. The time required for complete utilization of a limited amount of acetic acid or glucose is not affected by illumination in the absence of carbon dioxide. 3. The time required for complete utilization of a limited amount of glucose is not affected by the simultaneous occurrence of photosynthesis. It must therefore be concluded that the accumulating product of photosynthesis cannot be glucose but must be some slowly respirable (storage) material. 4. Possible interrelationships between oxidative assimilation and photosynthesis may be further studied by following, in darkness and in light, the time course of oxidative assimilation of substrates which are possible intermediates in the two processes. PMID- 19873490 TI - SOME PROPERTIES OF PROTOPLASMIC GELS : II. CONTRACTION OF CHLOROPLASTS IN CURRENTS OF WATER ENTERING THE CELL AND EXPANSION IN OUTGOING CURRENTS. AB - The chloroplasts of Nitella may contract under natural conditions as well as under the influence of certain reagents. When a sufficient amount of water enters any part of the cell they contract in that region and they expand when the direction of the current is reversed. The current may be produced by placing water at one end of the cell and applying at the other end a solution which withdraws water from the cell. The contraction may be due to the washing out of substances from the chloroplast by the ingoing current. The outgoing current bearing dissolved materials from the sap may restore these substances and cause the chloroplasts to resume their normal shape. When blood or sodium dodecylsulfate is present in the ingoing current the contraction of the chloroplast usually fails to occur. PMID- 19873491 TI - THE PROLYTIC LOSS OF K FROM HUMAN RED CELLS. AB - The prolytic loss of K., i.e. the loss of K which takes place from red cells exposed to hypolytic concentrations of lysins, has been measured in systems containing distearyl lecithin, sodium taurocholate, sodium tetradecyl sulfate, saponin, and digitonin, by means of the flame photometer. The lysins are added in various concentrations to washed red cells from heparinized human blood, and the K in the supernatant fluids is determined after various intervals of time and at various temperatures. The prolytic loss K(p) is compared in every experiment with the loss K(s) into standard systems containing isotonic NaCl alone, with no lysin. The losses K(s) and K(p) increase with time, so that new steady states are approached logarithmically. The values of K(p) which correspond to the new steady states depend on the lysin used, being greatest with taurocholate and smallest with digitonin. The temperature coefficient of the loss is positive, and the extent and course of the losses have no apparent relation to the prolytic shape changes. In systems in which the loss of K is appreciable, it can be inhibited by the addition of plasma or of either cholesterol or serum albumin. Of these two substances, even when used in quantities which have an approximately equal effect in inhibiting hemolysis, serum albumin is much the more effective. Just as the prolytic loss of K occurs without the loss of any Hb, so in concentrations of lysin sufficient to produce hemolysis the loss of K, expressed as a percentage of the total red cell K, increases much more rapidly with lysin concentration than does the loss of Hb expressed as a percentage of the total Hb. The explanation of these relations depends on whether the loss of K is treated as being all-or-none in the case of the individual cell or as being the result of the loss of part of the K from all of the cells. This point has still to be decided. PMID- 19873492 TI - REJECTION THRESHOLDS OF THE BLOWFLY FOR A SERIES OF ALIPHATIC ALCOHOLS. AB - Series of concentrations of 15 aliphatic alcohols were presented in 0.1 M sucrose to the tarsi of antennectomized-labellectomized blowflies (Phormia regina Meigen). With the pri-n-alcohols the mean concentrations at rejection formed a Traube series. When the rejection thresholds for all the alcohols tested were compared with their boiling points, vapor pressures, molecular surface areas) molecular moments, water-cottonseed oil distribution coefficients, standard free energies, and activity coefficients, a very high degree of correlation was found in each case. It is concluded that the limiting process which was measured is concerned with the receptor cells rather than with some other element in the complex response. Stimulative power was evidently not dependent on osmotic pressure nor on rate of molecular diffusion in solution, and the correlation with vapor pressure was inverse. It is judged that surface energy relationships are concerned in stimulation, but the exact mechanism cannot be defined until more is known about the structure of the sensory surface and about the process of excitation. The physiological activity of the alcohols is related more closely to the ease with which they gain access to the cell than to their chemical interaction with cellular constituents. PMID- 19873493 TI - THE RELATIONSHIP BETWEEN CHEMICAL STRUCTURE AND THE RESPONSE OF BLOWFLIES TO TARSAL STIMULATION BY ALIPHATIC ACIDS. AB - Using the technique of proboscis extension in antennectomized-labellectomized flies, the rejection thresholds of Phormia regina for 18 fatty acids and one mineral acid have been determined. The conclusions reached on the basis of these data may be summarized in the following terms: Tarsal stimulation by acids involves the summation of components from at least two sources. Of these the hydrogen ion is the most important. The other major factor is probably the anion rather than the undissociated acid. The stimulating power of the anions (or free acid molecules) increases with increasing chain length in both the mono- and dicarboxylic series, but the rate of increase decreases as the series is ascended. Acids containing 6 or more carbon atoms are not sufficiently soluble in 0.1 M sucrose to reach the threshold of rejection. Substitution of -H in the acyl grouping by -Cl, -OH, =O or -COOH, the presence of a C=C bond, or a shift from the trans- to the cis- configuration all diminish the effectiveness of the anion (or free acid). But since such alterations also augment the degree of dissociation and consequently the concentration of hydrogen ions, the net result is ordinarily a lowering of threshold in terms of the molar concentration required for rejection. PMID- 19873494 TI - THE EFFECTS OF SULFATHIAZOLE AND OF PROPYL CARBAMATE ON THE RATE OF OXYGEN CONSUMPTION AND GROWTH IN ESCHERICHIA COLI. AB - 1. The rates of growth and of oxygen consumption by cells of E. coli have been measured under identical conditions, and the effects of sulfathiazole (ST) and of n-propyl carbamate (PC) on these two processes have been compared. 2. The rate of growth was measured by (a) the increase in the viable cell count, (b) the increase in the optical density of the culture, (c) the increase in the rate of oxygen consumption, and (d) the decrease in the ammonia of the medium. The results as indicated by these several measures were identical under the conditions of these experiments. 3. Concentrations of ST or of PC which are just sufficient to stop growth completely, lower the rate of oxygen consumption per unit of bacterial protoplasm to a value approximately 50 per cent of that seen in the absence of the inhibitor. 4. It is shown that the rate of oxygen consumption in cells from old cultures is less affected by ST than is the rate of oxygen consumption by cells from young cultures. It is probable that the rate of oxygen consumption by "old" cells is lower than that of "young" cells. 5. The effects of ST and PC on both the rate of oxygen consumption and the rate of growth are very similar, indicating in a general way, that the mechanism of the actions of these two inhibitors is similar. Furthermore, since both of them produce appreciable inhibition of the rate of oxygen consumption while they are inhibiting growth, the possibility that the effect on oxygen consumption is the immediate cause of the effect on growth must be entertained. PMID- 19873495 TI - THE OXYGEN CONSUMPTION ASSOCIATED WITH GROWTH IN ESCHERICHIA COLI AND THE EFFECT OF SULFATHIAZOLE AND OF n-PROPYL CARBAMATE ON IT. AB - 1. The rate of oxygen consumption by E. coli has been observed both in the presence and absence of ammonia which substance is used by this organism in these experiments as the sole source of nitrogen for growth. 2. After the ammonia has been completely taken up in a culture of E. coli, the rate of oxygen consumption by the culture is observed to fall rapidly. It becomes relatively constant again at a rate approximately 45 per cent of that existing immediately prior to the exhaustion of the nitrogen source. It appears that the fixation of ammonia, that is, growth, requires approximately 55 per cent of the oxygen consumed by the growing cell. 3. Inhibition of the oxygen consumption which is associated with ammonia fixation, by both sulfathiazole (ST) and n-propyl carbamate (PC) closely parallels the inhibition of growth by these compounds (as measured by viable cell counts, etc.). 4. The concentrations of ST and PC which inhibit growth exert little or no inhibitory effect on the rate of oxygen consumption by cells after the rate has fallen to the resting value. 5. It is pointed out that the above observations would be adequately accounted for if growth depended on a discrete fraction of the total oxygen consumption of the growing cell. 6. It is noted that PC, but not ST, has a significant accelerating effect on the oxygen consumption of the resting cell; and that for a given inhibition of growth, PC produces less inhibition of the total oxygen consumption of the cells, than does ST. The latter of these two observations would follow from the former if the resting oxygen consumption were a discrete entity. PMID- 19873496 TI - CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR : II. GENERAL PROPERTIES. AB - A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.5. It inhibits the proteolytic action approximately of an equal weight of crystalline trypsin by combining with trypsin to form a stable compound. Chymotrypsin is only slightly inhibited by soy inhibitor. The reaction between chymotrypsin and the soy inhibitor consists in the formation of a reversibly dissociable compound. The inhibitor has no effect on pepsin. The inhibiting action of the soybean inhibitor is associated with the native state of the protein molecule. Denaturation of the soy protein by heat or acid or alkali brings about a proportional decrease in its inhibiting action on trypsin. Reversal of denaturation results in a proportional gain in the inhibiting activity. Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin. Methods are given for measuring trypsin and inhibitor activity and also protein concentration with the aid of spectrophotometric density measurements at 280 mmicro. PMID- 19873497 TI - ISOLATION OF A CRYSTALLINE PROTEIN COMPOUND OF TRYPSIN AND OF SOYBEAN TRYPSIN INHIBITOR. AB - A crystalline protein compound has been isolated from a solution containing crystalline trypsin and crystalline soybean inhibitor. The protein consists of about equal weights of trypsin and of the inhibitor. Denaturation by heat or by alkali resolves the compound into its components. PMID- 19873498 TI - THE EFFECTS OF SERUM ON SPERMATOZOA. AB - A spermicidal factor was found in fresh human, bovine, rabbit, guinea pig, and rat sera. It kills the spermatozoa of its own species (except in the case of human serum) and the sperms of other species. It was unstable, thermolabile, and of large molecular size. It was present in limited quantity in the fresh serum and could be used up by a definite number of spermatozoa. It could be destroyed by sodium citrate, by Seitz filtration, by trypsin, and by snake venom. This factor was not present in tissue extracts and various plasma protein fractions. The strength or concentration of this factor varies in different individuals and in different species. This factor has several characteristics similar to those of complement. PMID- 19873499 TI - COMPARATIVE KINETICS OF HEMOLYSIS INDUCED BY BACTERIAL AND OTHER HEMOLYSINS. AB - A study has been made of the kinetics of lysis induced by various hemolytic agents. The course of bemolysis was followed by mixing lysin with washed human erythrocytes, removing samples from the mixture, and estimating colorimetrically the hemoglobin in the supernatant fluid of the centrifuged samples. Most of the curves (but not all of them, e.g. tyrocidine) obtained by plotting degree of hemolysis against time, were S-shaped. The initiation of lysis by streptolysin S' was delayed, and in this property, streptolysin S' was similar to Cl. septicum hemolysin. None of the other lysins studied exhibited a long latent period preceding lysis. The maximum rate of hemoglobin liberation was found, in the range of lysin concentrations studied, to be a linear function of concentration when theta toxin of Cl. welchii, pneumolysin, tetanolysin, or streptolysin S' was the lytic agent. With comparable concentrations of saponin, sodium taurocholate, cetyl pyridinium chloride, tyrocidine, duponol C, lecithin-atrox venom mixture, or streptolysin O, the relation between rate and concentration was non-linear. The critical thermal increment associated with hemolysis was determined for systems containing pneumolysin, theta toxin, streptolysin S', streptolysin O, tetanolysin, and saponin. The findings concerning the effect of concentration and temperature on the rate of hemolysis provide a basis for classifying hemolytic agents (Tables I and II). Hemolysis induced by Cl. septicum hemolysin was found to be preceded by two phases: a phase of alteration of the erythrocytes and a phase involving swelling. Antihemolytic serum inhibited the first but not the second phase while sucrose inhibited the second but not the first phase. PMID- 19873500 TI - METABOLIC INTERMEDIATES IN ADAPTIVE FERMENTATION OF GALACTOSE BY YEAST. AB - Pyruvic acid, which is known to be an intermediate of glucose fermentation, was added to yeast during adaptation to galactose fermentation. It was found to neutralize the inhibition by sodium fluoride, and to decrease the apparent time of adaptation from 90 to about 45 or 60 minutes. In control experiments, it was shown that intact yeast is unable appreciably to ferment or decarboxylate alone, although it oxidizes the compound readily. Experiments in which galactose and pyruvate were added at various times and in different orders were used to eliminate the possible complications of the rates at which these compounds penetrate the cells. Under these conditions, it was not possible to reduce the time of adaptation below 45 minutes. It was concluded that the role of added pyruvate was to serve as a source of acetaldehyde, which in turn could accept hydrogen and be reduced to alcohol. Substances, such as triose phosphate, which could serve as hydrogen donors were not produced from galactose in appreciable quantities until 45 minutes had elapsed. This time was therefore inferred to be the true adaptation time, during which the first synthesis of adaptive enzymes occurred. Some determinations of the distribution of phosphorylated intermediates at various stages during the adaptive process were carried out. It was found that ATP, which usually serves to phosphorylate hexoses, accumulates during the preadaptive phase, diminishes rapidly after 60 minutes, and subsequently increases once more. The source of the ATP phosphate appeared to be PPA or triose phosphate initially present in the cells. It was inferred that the adaptive enzyme was concerned with the phosphorylation of galactose and the conversion of the phosphate ester to a glucose ester, which could then be fermented by the normal enzymes of the cell. Added ATP was found to stimulate adaptation to a considerable extent, but did not shorten the time of adaptation below 75 minutes. This seemed consistent with the role of ATP as a phosphate donor for galactose. Creatine was found to inhibit adaptation to some degree, in agreement with its known ability to act as a competitive phosphate acceptor. It was demonstrated that yeast produces, during and after adaptation, substances which shorten the apparent adaptation time of fresh samples of yeast. In agreement with our other findings, it appeared that such substances were not formed before about 45 minutes. They are probably not metabolic intermediates, and may be identical with the adaptive principle which can be extracted from adapted cells. PMID- 19873501 TI - THE KINETICS OF MULTIPLE ENZYME INHIBITION. AB - The adaptive fermentation of galactose by yeast is inhibited by fluoride and azide. At sufficiently low concentrations, however, it is stimulated. From a mathematical analysis, using the known fact that fluoride inhibits the enzymes enolase and adenosinetriphosphatase, it is possible to infer the existence of such stimulation. Conditions for this effect are derived which relate the sensitivities of the enzymes to the poison with the rate constants of the various reactions in the fermentation chain. PMID- 19873502 TI - ACTION OF PAPAIN AND FICIN ON TADPOLES AND ARBACIA EGGS. AB - Living tadpoles and Arbacia eggs are not digested by ficin or papain although the dead organisms are. Arbacia eggs develop in papain solutions but the cells become separated. Development is normal in ficin and trypsin solutions. PMID- 19873503 TI - PLASTEIN FROM PEPSIN AND TRYPSIN. PMID- 19873504 TI - K-Na EXCHANGE ACCOMPANYING THE PROLYTIC LOSS OF K FROM HUMAN RED CELLS. AB - In systems containing human red cells and sodium taurocholate as a lysin, or distearyl lecithin as a sphering agent, the prolytic loss of K at 25 degrees C. is accompanied by a gain of Na by the cell, the gain being somewhat greater than the K loss. A small volume increase accompanies the exchange. The kinetics of the K loss and the Na gain are similar to those already described; i.e., the changes are rapid at first, and slow down so that after 12 to 20 hours it appears that a new steady state is being approached. Similar, but smaller, losses of K and gains of Na occur when the cells stand in isotonic NaCl at 25 degrees C. without the addition of a lysin or sphering agent. On these and other experimental grounds, it is impossible to retain the idea that the mammalian red cell in general is impermeable to cations. The cells nevertheless seem to be in a steady state with respect to their environment, their ionic composition changing as the composition of the environment is changed. The possible processes by means of which one steady state can be exchanged for another-changes in the permeability of a surface membrane, changes in the velocity of an active ion transfer process dependent on red cell metabolism, and changes in the activity of the ions in the red cell interior as a result of changes in an orderly internal structure-are discussed. PMID- 19873506 TI - THE ULTRACENTRIFUGE STUDY OF PLASTEIN. PMID- 19873505 TI - STUDIES ON THE PHYSIOLOGICAL EFFECTS OF NON-POLAR-POLAR ORGANIC ELECTROLYTES : I. THE INFLUENCE UPON THE RESTING POTENTIAL OF FROG MUSCLE. AB - 1. The commonly used detergents have a poisonous effect, which is due to the non polar-polar configuration of their organic anion. The non-polar organophilic half of the ion is built up by a long chain of alkyl radicals (8 to 18 carbon atoms), the polar hydrophilic half by a sulfonate or sulfate. If brought into contact with the organic surface membrane of a cell, this structure, due to the strong attachment of the alkyl chains to its surface, and due to the pull of the hydrophilic part towards the surrounding water, is subjected to a heavy stress terminating in tearing to pieces the membrane (by denaturing and loosening the membrane components; bacteriolysis, cytolysis). Correspondingly, with frog muscle, one end of which has been treated with the detergent solution, an irreversible negative injury potential is produced. 2. Applying, instead, the compounds bearing short chains of alkyl radicals (1 to 6 carbon atoms), producing less stress on the membrane and correspondingly a slighter derangement of its architecture, a reversible positive resting potential appears. This is interpreted to be the effect of the non-polar part of the anion, which, due to its surface activity, intrudes into the pores of the membranes, notwithstanding the negative charge of their walls. 3. The short chained detergents seem to be replaceable by various organic "semidetergents," the organophilic behavior of their anion being represented by a slight chemical affinity (NH(2)), the hydrophilic by the effect of a carboxyl group (COO) instead of sulfate or sulfonate. The effect of the semidetergents on muscle is a positive reversible potential. Their physiological significance may be visualized as a functional activation. PMID- 19873507 TI - A STUDY OF THE ADENOSINE TRIPHOSPHATASE ACTIVITY OF MYOSIN AND ACTOMYOSIN. AB - 1. An experimental study was made on the adenosine triphosphatase action of crystalline myosin and actomyosin preparations under different conditions. 2. No enzymatic activity was found in the absence of salts. Activation was given by KCl and CaCl(2), whereas MgCl(2) in the presence of other ions inhibited. 3. The effect of pH is complex. In stabilizing buffers or at low temperature, there are two optima (pH 6.2 to 6.5 and pH 9.2) provided Ca is present. Without Ca only the acid optimum is found. The highest activities are reached in glycine buffer at pH 9.2 in the presence of Ca. 4. The study of the Mg-Ca antagonism revealed that the inhibition due to Mg is fully developed with Mg:Ca ratios less than 1, the inhibition usually exceeding 90 per cent. 5. It is shown that in the muscle the myosin-ATPase is most probably also subjected to the inhibitory action of the Mg ions. 6. From data in the literature it is calculated that the liberation of inorganic phosphate during muscular activity takes place at a rate of at least 0.200 mg. P per mg. myosin per minute. 7. From the results of the present study it is found that the myosin in the muscle can liberate inorganic phosphate from ATP at a rate of at most 0.003 mg. P per mg. myosin per minute. 8. It is concluded therefore that myosin-ATPase cannot be responsible for the liberation of the main part of the phosphate in contracting muscle, and therefore cannot have the role in muscular metabolism ascribed to it in recent hypotheses and discussions. PMID- 19873508 TI - THE DARK ADAPTATION OF THE COLOR ANOMALOUS MEASURED WITH LIGHTS OF DIFFERENT HUES. AB - Determinations of minimum light thresholds as a function of time in the dark have been made for four color normal, three deuteranopic (or deuteranomalous), and four protanopic (or protanomalous) subjects. Measurements were made with red, reddish orange, yellow, green, violet, and white test lights. Dark adaptation curves for the deuteranopes and deuteranomalous are essentially identical with those of the color normal for all colors. The cone portions of the protanopic dark adaptation curves measured with the red, reddish orange, yellow, and white lights are higher than the corresponding data for the color normal, the discrepancy between the two sets of data decreasing from the long to short wave lengths. Dark adaptation curves for the protanopes and protanomalous measured with green and violet light are essentially normal in appearance. A theoretical explanation is advanced to account for these findings in terms of the known sensitivity characteristics of the normal and color-anomalous eye. PMID- 19873509 TI - SOME ASPECTS OF SECRETION : I. SECRETION OF WATER. AB - If we increase the osmotic pressure at one end of a Nitella cell by applying a solution of sucrose and if we subsequently submerge the entire cell in water we find that water enters at the end where the osmotic pressure is higher and comes out of the cell at the other end. If similar inequalities of osmotic pressure should arise as the result of metabolism we can understand how a secreting cell might take up water at one spot on its surface and expel it in another spot and thus bring about the secretion of water. The Nitella cell can expel water from a region of the cell which is in contact with water, air, or mineral oil. PMID- 19873510 TI - SOLUBILITY OF MUSTARD GAS [BIS (beta-CHLOROETHYL) SULFIDE] IN WATER, MOLAR SODIUM CHLORIDE, AND IN SOLUTIONS OF DETERGENTS. AB - 1. The solubility of mustard (H) in water and in molar sodium chloride was found to be 5.8 x 10(-3) molar and 3.2 x 10(-3) molar respectively or 0.92 mg. per ml. and 0.5 mg. per ml. Solubility curves have been drawn and the usefulness of this method in examining the homogeneity of H preparations as well as in establishing their solubility, is discussed. 2. Certain detergents increase the solubility of H in water. The solubility was found to increase with the concentration of detergent. 3. Many detergents were found to affect the interfacial tension between H and water so that with slight agitation liquid H breaks up into minute droplets. This in turn greatly accelerates the rate of solution. PMID- 19873511 TI - THE SULFONIUM SALT OF MUSTARD GAS: BIS-beta-[BIS(beta-HYDROXYETHYL) SULFONIUM] ETHYLSULFIDE DICHLORIDE (H.2TDG). AB - 1. The sulfonium salt H.2TDG is formed when H is mixed with even dilute solutions of TDG. Crystalline H.2TDG was isolated from such a reaction mixture. A simple method of preparation of this salt is outlined. 2. A material which differs from H.2TDG in that it hydrolyzes faster, is formed when H hydrolyzes in water. This material is probably H.1TDG but it was not isolated. Approximately 5 to 8 per cent of the original H is converted to this sulfonium salt. 3. The hydrolysis constant of M/100 H.2TDG has been determined at 20 degrees , 25.5 degrees , 37 degrees , 75 degrees , and 100 degrees C., a temperature coefficient, Q(10), of 3 4 was obtained. The effect of temperature is in agreement with that predicted by the Arrhenius equation. An activation energy of 26,000 calories was calculated. PMID- 19873512 TI - PROTAMINE PURIFICATION OF STREPTOKINASE AND EFFECT OF pH AND TEMPERATURE ON REVERSIBLE INACTIVATION. AB - 1. Treatment of crude concentrates of streptokinase with protamine results in removal of about 90 per cent of the nitrogenous material, including nucleic acid and protease inhibitor, with little or no loss of activity. 2. Streptokinase solutions undergo reversible inactivation with changes in pH. The rate and extent of inactivation are dependent on pH, being greatest over a very narrow range about pH 5. The rate and extent of inactivation are also a function of temperature, both increasing with the temperature of incubation. The rate of reactivation is a function of pH and temperature, increasing as either is raised. However, as the temperature is raised above about 23 degrees C., or the pH above about 9, a secondary, irreversible inactivation of streptokinase occurs. PMID- 19873513 TI - DETECTION OF MUSTARD GAS (H), LEWISITE (L), ETHYLDICHLORARSINE (ED), AND PHENYLDICHLORARSINE (PD) WITH TRAINED DOGS OR RATS. AB - Dogs and rats may be trained to detect very low concentrations of mustard gas (0.1 gamma per liter of air) by shocking the animals with an induction coil when they touch meat which has been exposed to the gas. Animals trained in this way will refuse meat which is contaminated with the gas. PMID- 19873514 TI - PROLYTIC ION EXCHANGES PRODUCED IN HUMAN RED CELLS BY METHANOL, ETHANOL, GUAIACOL, AND RESORCINOL. AB - When the washed red cells of heparinized human blood are exposed at 4 degrees C. to methanol, ethanol, guaiacol, or resorcinol in hypolytic concentrations in isotonic NaCl, the prolytic loss of K at the end of 20 hours varies from about 25 per cent of the initial K content of the cells in the case of 3.1 M methanol to about 55 per cent of the initial K in the case of 0.04 M resorcinol. As in the case of the prolytic losses observed with other lysins, the K loss is rapid at first and then slows down so that what appears to be a new steady state is reached logarithmically. The K lost from the cells during the period of the prolytic loss is replaced by an approximately equivalent amount of Na, derived from the isotonic NaCl in which the cells are suspended. The Na which enters can be replaced by K by washing the cells in isotonic KCl, and this K can again be replaced by Na by washing the cells in isotonic NaCl. The remainder of the cell K., i.e. the K which was not lost during the period of the prolytic loss, is retained in the cell unaffected by these washing procedures. The capacity of red cells for undergoing disk-sphere transformations is scarcely affected by their having been exposed to hypolytic concentrations of methanol, ethanol, guaiacol, or resorcinol in isotonic NaCl, and their resistance to osmotic hemolysis and to lysis by saponin and digitonin is altered only in minor respects even when as much as 50 per cent of the cell K has been exchanged for Na. Some restriction to the movement of K between the cell and its environment is apparently modified irreversibly when the cell is exposed to hypolytic concentrations of lysins, and the modification is such that only a fraction of the cell K is affected, the fraction being a function of the lysin concentration, the duration of its action, and other factors. A modification of some part of the cell structure and of the properties dependent on its integrity is probably involved: K may be lost more readily from some cells than from others, from some parts of the cell more readily than from other parts, or the explanation may lie in changes in the extent to which Hb binds ions or in modifications of metabolic processes. PMID- 19873515 TI - THE EFFECT OF ENVIRONMENTAL POTASSIUM AND CALCIUM CONCENTRATIONS ON THE RECOVERY OF THE ACTION POTENTIAL AND RELATED FUNCTIONS OF NERVE. AB - 1. When the Ringer's solution applied to isolated frog sciatic nerve contains K(+) in concentrations greater than 2 x standard, the height of the spike and of the after-potential is decreased, as is the duration of the after-potential; recovery of height and of excitability following response is delayed; degree and duration of supernormal excitability are decreased; postcathodal depression and postanodal enhancement are increased and prolonged. 2. The nerve functions just listed in general all change in the opposite direction when exposed' to increased environmental [Ca(++)]. (4.5-20 x standard) or decreased [K(+)] (0.05-0.2 x standard). The effects of decreased [Ca(++)] (0.20-0.25 x standard) are indeterminate. 3. When [K(+)] and [Ca(++)] are both greater than 2 x standard, whatever the ratio between the concentrations the effects characteristic of high [K(+)] eventually predominate. However, these effects, except for those involving spike height, are preceded by effects characteristic of high [Ca(++)] when this cation is present in sufficient excess. 4. When [K(+)] and [Ca(++)] are reduced to equal low levels (0.1-0.2 x standard), effects characteristic of low [K(+)] and high [Ca(++)] are obtained. 5. The experimentally determined order of ability of the environments to produce changes characteristic of high K(+) (which is the reverse of the order of their ability to produce changes characteristic of high [Ca(++)]), is not the order of their K(+) or Ca(++) concentrations, nor of the ratio between these concentrations (Table II). 6. The results may be explained by the assumption that the functions investigated are all to greater or less degree controlled by (1) the [K(+)]/[Ca(++)] ratio and (2) the K(+) concentration, at least when this exceeds a critical level. Control by [K(+)] is more effective for spike height and its recovery after stimulation than for the other functions. The special role of K(+) is attributed to an unknown specific effect of this ion which Ca(++) is unable to oppose. It is suggested that this K(+) effect in general becomes marked on the frog nerve functions investigated when the K(+) concentration is somewhat above 2 x standard, while the [K(+)]/[Ca(++)] ratio must be changed by a factor of 4 or more before it exerts a definite effect on these functions. 7. In standard and in modified cationic environments, nerve functions vary in the ease with which they manifest changes characteristic of high [K(+)] or of high [Ca(++)]. 8. The after-potential functions are less completely controlled by the cationic environment than are the other functions investigated. PMID- 19873516 TI - ISOLATED CHROMOSOMES. PMID- 19873517 TI - IDENTIFICATION OF MONO-IODOTYROSINE FROM IODINATED PEPSIN. AB - Isolation of mono-iodotyrosine from slightly iodinated pepsin has been repeated and the properties of the product compared with those of synthetic dl-3 iodotyrosine. Ultraviolet absorption spectra, pK values of the phenol group, solubility measurements, and partition coefficients were so nearly identical for the two materials that there is now no reason to doubt that the product from pepsin is 3-iodotyrosine. PMID- 19873518 TI - THE RELATION OF ENZYMATIC ADAPTATION TO THE METABOLISM OF ENDOGENOUS AND EXOGENOUS SUBSTRATES. AB - The source of energy for enzymatic adaptation has been investigated. Aerobically, it is found that the endogenous carbohydrate reserves may be used as such a source. In cells depleted of their reserves, the adaptive substrate itself can be oxidized even while it cannot be fermented, and so can serve as a source of energy for the adaptation to a fermentative mode of utilization. Anaerobically, adaptation may occur at the expense of stored energy-rich compounds, while the reserves and the adaptive substrate are now useless as fuel. Such compounds appear to be more plentiful in young than in old cells. The addition of any fermentable substrate, such as glucose, leads to rapid anaerobic adaptation. Experiments in which maltose-adapted cells are adapted anaerobically to galactose with the aid of a little added maltose, and conversely, show that fermentability is the criterion of usefulness for an exogenous substrate in aiding the adaptive process. None of the endogenous and exogenous energy sources which have been investigated will facilitate adaptation unless the adaptive substrate is present while they are being consumed. The significance of these findings and the adequacy of "activation" hypotheses to explain enzymatic adaptation has been discussed. PMID- 19873519 TI - THE PREADAPTIVE OXIDATION OF GALACTOSE BY YEAST. AB - A preadaptive purely aerobic utilization of galactose by yeast cells has been demonstrated. Hence, the adaptation by yeast to galactose is not to its utilization per se, but specifically to its metabolism by a glycolytic mechanism. An examination of this preadaptive oxidation of galactose reveals that it has many characteristics in common with the endogenous metabolism of yeast. Included among these are the similarities of the R.Q. values and the response of the Q(O(O2) ) and Q(CO(CO2) ) (O(2) ) to KCN and iodoacetic acid. Further, a competitive interaction appears to exist between the endogenous respiration and the preadaptive oxidation of the galactose. The latter can replace the endogenous respiration as a source of energy for the adaptation to the fermentation of the galactose. Carbon balance studies of the galactose oxidation revealed that polysaccharide could be formed as a result of this metabolism during the preadaptive period. Non-adaptable cells were also found to possess the capacity to oxidize galactose in the complete absence of any ability to metabolize it anaerobically. The significance of these findings for the biochemistry and physiology of the adaptation is discussed. PMID- 19873520 TI - THE CHEMICAL COMPOSITION OF ISOLATED CHROMOSOMES. AB - By means of 1 M NaCl isolated lymphocyte chromosomes can be separated into two fractions, each of which contains nucleoprotein. The fraction soluble in M NaCl consists largely of desoxyribose nucleohistone, and constitutes 90 to 92 per cent of the mass of the chromosome. The insoluble residue (the residual chromosome is a coiled thread containing some 12 to 14 per cent of ribose nucleic and about one fifth as much desoxyribose nucleic acid; the residual chromosome accounts for 8 to 10 per cent of the mass of the chromosome. The staining of chromosomes-whether by the Feulgen procedure, by hematoxylin, orcein, or by basic dyes such as crystal violet-is due to the nucleohistone fraction which contains about 96 per cent of the nucleic acid of the chromosome. The form of the chromosome is due primarily to the protein thread of the residual chromosome. This thread is the only linear structure of microscopic dimensions in the chromosome that is not readily dispersed. When chromosomes are broken, it must be supposed that a break is made in the protein thread of the residual chromosome. The foregoing provides evidence for considering the residual chromosome to be the basis of the linear order of the genes. This would mean either that the residual chromosome is a structure around which the genes are organized or that the genes form part of its substance. PMID- 19873521 TI - THE BIOSYNTHESIS OF C COMPOUNDS : I. THE BIOSYNTHESIS OF C-LABELED STARCH. AB - 1. Starch, containing 7.05 atom per cent C(13) excess has been produced in the mesophyll cells of bean leaves, starting with C(13)O(2) containing 7.26 atom per cent C(13) excess. Approximately 67 per cent of the C(13) taken up by the leaves was determined in the starch fraction. 2. The soluble carbohydrate, containing 6.72 atom per cent C(13) excess, accounts for approximately 23 per cent of the C(13) taken up by the leaves. The remainder was principally in the coarse tissue fragments fraction (9.73 per cent of the C(13) utilized). 3. The apparatus and procedures used in this experiment are described. PMID- 19873522 TI - STUDIES ON THE SONIC TREATMENT OF TOBACCO MOSAIC VIRUS. AB - Centrifugally purified samples of tobacco mosaic virus were subjected to intense sound vibrations of 9,000 cycles per second for 0, 2, 8, 16, 32, and 64 minutes. The viscosity and stream birefringence of the samples decreased with time of sonic treatment, but no chemical changes were found. Electron micrographs of the samples show that the particles are broken perpendicular to their long axis. In the untreated sample 62 per cent of the particles are about 280 mmicro in length. As sonic treatment continued, the number of particles of this length decreased exponentially with time, the number half this length increased and then decreased, and the number of quarter length particles subsequently increased and then decreased. The biological activity of the samples, as determined by the half leaf lesion method, decreased exponentially with time of sonic treatment with a rate constant given by k = 0.13 min.(-1). A correlation exists between the size distributions and biological activity and shows that only the particles of length 280 mmicro are the biologically active units. Tobacco mosaic virus particles can be made to aggregate end-to-end when the material is heated at its isoelectric point and reheated after being brought back to pH 7. Material which was not sonic treated and was made to aggregate showed reduced biological activity, but the activity was increased when the aggregated material was subjected to strong mechanical stirring. Material which was sonic treated for 32 minutes and which was made to aggregate showed the same biological activity as the material which was sonic treated but not aggregated. PMID- 19873523 TI - ON THE EFFECT OF COCAINE UPON SODIUM-DEFICIENT FROG NERVE. AB - Cocaine diffuses through the epineurium with remarkable rapidity. The coefficient of diffusion of cocaine in the epineurium cannot be less than 0.44 x 10(-4) cm.(2)/min.; it probably is not less than 1.22 x 10(-4) cm.(2)/min. Lack of sodium markedly sensitizes the nerve fibers to the anesthetic action of cocaine. With sodium-deficient A fibers the action of cocaine develops in two phases. During the first phase cocaine substitutes for sodium and restores to A fibers the ability to conduct impulses; during the second phase cocaine produces anesthesia. It is suggested that cocaine anesthetizes the nerve fibers through the sodium mechanism; i.e., by interfering with some of those chemical reactions in which, directly or indirectly, the internal sodium takes part. PMID- 19873524 TI - THE EFFECT OF TRYPSIN, CHYMOTRYPSIN, RIBONUCLEASE, AND DESOXYRIBONUCLEASE ON ACTIVE, INACTIVE, AND REVERSIBLY INACTIVATED MEGATHERIUM PHAGE. AB - The effect of trypsin, chymotrypsin, and desoxyribonuclease on active, reversibly inactivated, and heat-inactivated B. megatherium phage, and on living and dead B. megatherium and B. coli has been determined. The results are summarized in Table I. PMID- 19873525 TI - The Mechanical Properties of Rat Tail Tendon. AB - The load-strain and stress-relaxation behavior of wet rat tail tendon has been examined with respect to the parameters strain, rate of straining, and temperature. It is found that this mechanical behavior is reproducible after resting the tendon for a few minutes after each extension so long as the strain does not exceed about 4 per cent. If this strain is exceeded, the tendon becomes progressively easier to extend but its length still returns to the original value after each extension. Extensions of over 35 per cent can be reached in this way. Temperature has no effect upon the mechanical behavior over the range 0-37 degrees C. Just above this temperature, important changes take place in the mechanical properties of the tendon which may have biological significance. The application of the techniques used here to studies of connective tissue disorders is suggested. Some of the mechanical properties of tendon have been interpreted with a simple model. PMID- 19873526 TI - Apparatus for the Maintenance of Bacterial Cultures in the Steady State : II. Improved turbidity control and culture cell. AB - (1) A more convenient method for maintaining constant turbidity in the culture cell is described. (2) An improved culture cell and cell wipers which do not cause foaming are described. PMID- 19873527 TI - The Nature and Significance of the Bohr Effect in Mammalian Hemoglobins. AB - The oxygenation of hemoglobins is accompanied by the dissociation of protons. The number of protons discharged is inversely related to the size of the mammal from which the hemoglobin comes. The number of mercuric ions which are immediately bound by hemoglobins is approximately equal to the number of protons dissociated during oxygenation. Pretreatment of human hemoglobin by N-ethylmaleimide, which appears to bind only sulfhydryl groups prevents the binding of any mercuric ions under conditions when mercuric ions would otherwise be bound. These facts suggest that those mammals with higher metabolic rates will generally possess hemoglobins with a larger number of appropriately placed cysteine residues. PMID- 19873528 TI - The Response Properties of Single Ganglion Cells in the Goldfish Retina. PMID- 19873529 TI - On Dielectric Constant and Enzymatic Kinetics : III. Interrelationships of dielectric constant and pH. AB - The dielectric effects on trypsin and alpha-chymotrypsin activities have revealed that at pH 7.8 the active species of the former is the cation while that of the latter is the anion. The present study on the dielectric effects along the pH activity curves shows that trypsin remains positive within the pH range of 5.5 to 8.5. Conversely, alpha-chymotrypsin is positive from pH 5.5 to 6.6, negative from 6.6 to about 8.1, and at pH 8.25 becomes positive again. The first point of inversion in charge sign shifts from 6.6 to 7.15 with the addition of 0.05 M phosphate buffer. The point of inversion does not seem to be modified significantly by changes in the substrate structure. At pH values near the point of inversion the plots of rate log vs. 100/D are broken lines formed by various straight portions, the slope of each varying progressively from a maximum positive to a maximum negative value. This suggests an effect of resonance possibly attributable to an imidazole group. As an attempt to explain the two observed points of sign inversion in alpha-chymotrypsin, the possibility is suggested that different enzyme configurations are disclosed by the combined action of pH and dielectric constant. On this theoretical basis, it i6s feasible that more than one isoionic point exists. PMID- 19873530 TI - Comparative Studies on Dark Adaptation in the Compound Eyes of Nocturnal and Diurnal Lepidoptera. AB - A comparative analysis has been carried out of the time course and range of dark adaptation in the compound eyes of some common butterflies and noctuid moths (Lepidoptera). The change in sensitivity of the eye during dark adaptation was determined by measurements of the intensity of illumination necessary to elicit an electrical response of a given magnitude of the eye. It was found that the curve for dark adaptation in the diurnal species was smooth. The range of adaptive change varied in different species but usually did not cover more than 1 to 1.5 log units. In the nocturnal species the dark adaptation was found to proceed in two phases. The first phase was usually completed in less than 10 minutes and covered a range of 1 to 1.5 log units. The second phase was more prolonged and covered a range of 2 to 3 log units. In some of the experiments on nocturnal species the second phase failed to appear. Measurements of the size of the response at different intensities showed that the intensity/amplitude relationship was the same in the light-adapted eye as in the dark-adapted eye. In the nocturnal insects the response of the eye in the light-adapted condition was about 20 per cent of that in the dark-adapted eye, while in diurnal insects it was about 60 per cent. PMID- 19873531 TI - Studies on the Relation between the Pigment Migration and the Sensitivity Changes during Dark Adaptation in Diurnal and Nocturnal Lepidoptera. AB - The functional significance of the pigment migration in the compound insect eye during dark adaptation has been studied in diurnal and nocturnal Lepidoptera. Measurements of the photomechanical changes were made on sections of eyes which had been dark-adapted for varying periods of time. In some experiments the sensitivity changes during dark adaptation were first determined before the eye was placed in the fixation solution. No change in the position of the retinal pigment occurred in Cerapteryx graminis until the eye had been dark-adapted for about 5 minutes. The start of the migration was accompanied by the appearance of a break in the dark adaptation curve. During longer periods of dark adaptation the outward movement of the pigment proceeded in parallel with the change in sensitivity, the migration as well as the adaptive process being completed within about 30 minutes. In the diurnal insects chosen for the present study (Erebia, Argynnis) the positional changes of the retinal pigment were insignificant in comparison with the movement of the distal pigment in Cerapteryx graminis. On the basis of these observations the tentative hypothesis is put forward that the second phase of adaptive change in nocturnal Lepidoptera is mediated by the migration of the retinal pigment while the first phase is assumed to be produced by the resynthesis of some photochemical substance. In diurnal insects which have no appreciable pigment migration the biochemical events alone appear to be responsible for the increase in sensitivity during dark adaptation. PMID- 19873532 TI - Inotropic Effects of Trains of Impulses Applied during the Contraction of Cardiac Muscle. AB - THE APPLICATION OF A TRAIN OF SUPRAMAXIMAL STIMULI DURING THE ABSOLUTE REFRACTORY PERIOD OF A CARDIAC MUSCLE PREPARATION HAS TWO EFFECTS: a depression of the contraction during which it is applied, and a large potentiation of subsequent contractions. The former is ascribed to a direct effect upon the cell membrane, and is an indication of the continued control of the contractile event by this membrane. The latter is explained as a sudden liberation of norepinephrine by a stimulation of embedded nerve elements, which norepinephrine then distributes itself through the tissue and finally diffuses away. PMID- 19873533 TI - Quantitative Studies of White Matter : I. Enzymes involved in glucose-6-phosphate metabolism. AB - Total lipid and six enzymes closely related to the metabolism of glucose-6 phosphate have been measured in ten tracts of the rabbit. Lipid content appears to be a valid indicator of the degree of myelination. Heavily myelinated tracts have much larger amounts of glucose-6-phosphate dehydrogenase than lightly myelinated ones but there is no corresponding difference in 6-phosphogluconate dehydrogenase. In fact the ratios between the two enzymes were found to vary over a ninefold range. Hexokinase is found in largest amounts in tracts with relatively little lipid, and this tends to be true for phosphofructokinase as well. The fibrillar layer of olfactory bulb is exceptional with regard to both enzymes, and to glucose-6-phosphate dehydrogenase. The enzymes are present in amounts which are more than adequate to support glucose metabolism at a rate commensurate with the known rates of O(2) uptake by various tracts. The distribution of some of the enzymes is compatible with the notion that the nodes of Ranvier are regions of high metabolic activity. A simple algebraic relationship is found to hold fairly well for the distribution of four of the enzymes among the tracts. PMID- 19873534 TI - The Electrophysiology of Electric Organs of Marine Electric Fishes : I. Properties of electroplaques of Torpedo nobiliana. AB - Single electroplaques of Torpedo nobiliana have been studied with microelectrode recording. Direct evidence is presented that the only electrogenically reactive membrane of the cells is on the innervated surface and that this membrane is electrically inexcitable. Responses are not evoked by depolarizing currents applied to this membrane, but only by stimulating the innervating nerve fibers. The responses arise after a latency of 1 to 3 msec. This latency is not affected by large depolarizing or hyperpolarizing changes in membrane potential. Various properties that have been theoretically associated with electrically inexcitable responses have been also demonstrated to occur in the electroplaques. The neurally evoked response is not propagated actively in the membrane and may have different amplitudes and forms in closely adjacent regions. The maximal responses frequently are slightly larger than the recorded resting potential but the apparent small overshoot may be due to difficulty in recording the full resting potential. The responses are subject to electrochemical gradation and appear inverted in sign on applying strong outward currents across the innervated membrane. This membrane is cholinoceptive and shows marked desensitization. The membrane of the uninnervated surface has a very low resistance, a factor that aids maximum output of current during the discharge of the electric organ. PMID- 19873535 TI - The Electrophysiology of Electric Organs of Marine Electric Fishes : II. The electroplaques of main and acccessory organs of Narcine brasiliensis. AB - Studies on the electric organs of Narcine brasiliensis and particularly of the responses of the electroplaques of the accessory organ confirm and amplify data obtained on the electroplaques of Torpedo nobiliana. Only the innervated surface is electrogenically reactive and the uninnervated surface has a low resistance, as in Torpedo electroplaques. However, in the accessory organ of Narcine the innervated surface is the dorsal, rather than the ventral, and it has a different pattern of innervation. The responses of single cells of the accessory organ exhibit marked facilitation on repetitive stimulation. The facilitated responses, like the individual responses of Torpedo and of the main organ of Narcine, are electrochemically graded on changing the membrane potential with applied currents, and are inverted in sign when outward currents through the innervated face are very strong. PMID- 19873536 TI - The Electrophysiology of Electric Organs of Marine Electric Fishes : III. The electroplaques of the stargazer, Astroscopus y-graecum. AB - The electroplaques of Astroscopus y-graecum were studied in situ with microelectrode recordings. Despite the distant taxonomic relations and the different origins of the organs, their properties in the teleost and torpedine marine electric fishes are remarkably similar. Only the innervated membrane (the dorsal) is electrogenically reactive in Astroscopus, and it, too, does not respond to electrical stimuli. As in the torpedine fishes, the uninnervated membrane of the electroplaques offers a very low resistance to the discharge of the innervated membrane. Additional direct evidence for electrical inexcitability of the reactive surface was obtained by denervating one of the bilateral organs. The denervated one did not respond to strong electrical stimuli which evoked responses in the opposite, innervated organ. The denervated electroplaques had a normal resting potential and were depolarized by acetylcholine and carbamylcholine similarly to normal cells. Other properties related to electrical inexcitability were also demonstrated. A pharmacological finding of considerable theoretical significance is that desensitization occurred on depolarizing cells with acetylcholine but was absent on depolarizing them with carbamylcholine. PMID- 19873537 TI - The Effect of Caffeine on Radiocalcium Movement in Frog Sartorius. AB - Caffeine increases resting calcium influx approximately threefold in normally polarized and in potassium-depolarized fibers of frog sartorius muscles. It does not affect the transient rapid increase in calcium influx that occurs at the beginning of a potassium depolarization. Calcium outflux in Ringer's solution, in zero calcium Ringer's solution, and in zero calcium Ringer's solution plus 0.004 M EDTA is also markedly increased by caffeine. The increased outflux reaches a rate which is approximately the same as the increased calcium influx. One interpretation of the findings is that caffeine reduces the binding of calcium both in the membrane and in the myoplasm; this increases the "permeability" to calcium and the ionic activity of calcium in muscle. This interpretation is consistent with the view that the contractile state of muscle is dependent at least in part on the thermodynamic activity of calcium in the muscle fibers. PMID- 19873538 TI - Studies on the Bohr Effect of Sheep Hemoglobin. AB - A simple method is described for the measurement of pH changes in hemoglobin solutions on oxygenation and reduction. Data are presented establishing the absence of a Bohr effect in p-chloromercuribenzoate [PCMB] treated hemoglobin. The influence of a number of sulfhydryl inhibitors on the Bohr effect of a hemoglobin solution is reported and an interpretation based on steric factors in the protein is proposed. PMID- 19873539 TI - Some Cation Interactions in Muscle. AB - It has been possible to treat potassium, rubidium, and cesium ion entry into frog sartorius muscle by the use of a model which assumes a limited number of sites at the cell surface. The ion concentration in an outer surface layer is regarded as the main factor determining the rate of inward movement. It is supposed that the concentration of ions in the external solution is effective in promoting inward movement only to an extent determined by the fraction of sites occupied. Equations are derived from the model which fit the inward flux versus applied concentration curves experimentally determined for the three ions. The ions were found to compete for the postulated sites in various bi-ionic mixtures, the competition being satisfactorily described by equations derived from the model. The constants assigned to each ion remain invariant and independent of gradients in electrochemical potential. The order of decreasing exchange rate found is K > Rb > Cs. The order of decreasing site affinity found is Rb > K > Cs which is the same order as that observed for the ion selectivity deduced from analytical measurements of cation preference after equilibration in various equimolal mixtures (Lubin and Schneider (21)). The manner in which such a model might affect the application of a theory which assumes electrical driving forces as well is discussed. PMID- 19873540 TI - Impedance of a Small Electrically Isolated Area of the Muscle Cell Surface. AB - A method has been developed permitting measurement of membrane impedance and current, as a function of transmembrane potential, at small, electrically isolated regions of the muscle cell surface without microelectrode impalement. The frequency dependence of the muscle cell membrane capacity found earlier by other methods has been confirmed. The average capacity is 3.5 microf/cm(2) with a phase angle of 71 degrees at 5 kilocycles. The internal phase angle of the complex impedance plot of whole muscle probably does not result from a distribution of fiber diameters and membrane capacities, since it also appears in the present experiments where measurements are confined to a small region of a single fiber. PMID- 19873541 TI - Na Extrusion by the Sartorius of Rana pipiens. AB - Sartorius muscles of R. pipiens may be enriched in sodium and depleted of potassium by prolonged soaking in the cold in K-free or low K Ringer's solution. Such K-depleted muscles take up potassium and extrude sodium when exposed to Ringer's solution containing 10 mM K at ordinary room temperature (ca. 20 degrees C), with no dependence on external Na ion concentration in either phase within fairly wide limits. Extrusion of excess fiber Na is demonstrated on single muscles using Na(24)-loaded tissues. Rate of exchange of excess fiber Na does not differ significantly from the rate of exchange of Na normally present in muscle fibers. PMID- 19873542 TI - Purification of B. megatherium Phage G and Evidence for a Muralytic Enzyme as an Integral Part of the Phage. AB - The Purification Of B. megatherium G phage is described and it is shown that DEAE cellulose chromatography combined with conventional methods gave a phage preparation which was at least 95 per cent pure, and contained 2.16 microg nitrogen/10(11) infective particles. The phage particle weight in molecular weight units was 91 x 10(6). The small amount of contaminating material appeared to represent phage "ghosts." An essentially 1:1 ratio of particles to infective units was found when data from electron microscopic counts or data from chemical analysis were related to phage infectivity. Comparison, by several methods, of the G phage and coliphage T2 shows that T2 is 2.6 times larger than G phage. The specific activity of the muralytic component obtained by disintegration of phage preparations with urea was unchanged by the purification indicating that the phage-"bound" muralytic activity is an integral part of the phage structure. PMID- 19873543 TI - Hydrolysis of Irradiated Ovalbumin by Pepsin. AB - Solid ovalbumin has been irradiated at three doses, 6.5, 25, and 40 megarads, under high vacuum. The native and irradiated samples have been hydrolyzed at pH 1.4 by pepsin, after centrifugation of the aggregates, if necessary. The number of bonds broken per ovalbumin molecule has been estimated by comparing the rate of protein destruction with the rate of formation of NH(2) groups. Both rates increase very much with the dose, but the number of bonds broken decreases. Sedimentation measurements show a strong shape modification of the soluble fraction in the case of the 25 and 40 megarad samples. The increase in asymmetry is bound to the increase in the rate of attack on gamma-irradiated ovalbumin by pepsin. Infrared spectra of the aggregates show small difference from those of the native samples. PMID- 19873544 TI - Some Seismic Profiles near the Western End of the Puerto Rico Trench. AB - A cooperative program of seismic refraction profiling was completed in the vicinity of the Puerto Rico Trench by Hudson Laboratories, Woods Hole, Lamont, and Texas A. & M. Profiles completed near the western end of the Trench were analyzed at Hudson Laboratories. Five seismic layers are indicated below the water layer. The thickness/velocity relationships are as follows: 5.1 km of 1.5 km/sec. (water); 1 km of 1.7 km/sec. (sediment); 1.5 km of 3 km/sec. (metamorphics?); 2 km of 5.5 km/sec. (basement); and 2 km of 7.1 km/sec. (high speed basement). Below these, typical Moho velocities of 8.1 km/sec. were measured. Total depth to Moho ranges from 9 to 12 km below sea level, the greatest variation occurring in the basement layers. The least depth was measured 65 miles north of the Puerto Rico Trench. PMID- 19873545 TI - Deoxyribonuclease from Salmon Testes : I. Purification and properties. AB - A procedure is described for the purification of salmon testis deoxyribonuclease II by means of acid extraction, fractional precipitation with ammonium sulfate, heat denaturation of extraneous proteins, and ethanol fractionation. This process separates the deoxyribonuclease activity from that of ribonuclease, phosphatase, phosphodiesterase, and protease. Over 50 per cent of the activity is retained with an over-all enrichment of 20,000-fold. The enzyme degrades both native and heat-denatured DNA, but the rate of degradation of the latter is only one-tenth that of the former. It does not hydrolyze apurinic acid. The enzyme is most stable in the pH range 4 to 5. Electrolytes are essential for the expression of its activity: monovalent ions satisfy the requirement, but divalent ones are much more effective. Above a certain optimum concentration, each electrolyte is inhibitory. The pH of maximal activity, under conditions of optimal ionic strength, is 4.8; the temperature optimum is near to 55 degrees C. PMID- 19873546 TI - Bioluminescence of Marine Dinoflagellates : I. An underwater photometer for day and night measurements. AB - Portable light-baffled underwater photometers have been designed for the measurement of dinoflagellate bioluminescence by day and night. Maximal light emission is obtained by mechanical stimulation in a defined volume. The pump which stimulates the dinoflagellates also constantly replenishes the sample volume so that continuous measurements are possible. Evidence for both diurnal variation and vertical migration is presented. Using luminous bacteria for calibration a single dinoflagellate has been found to emit of the order of 10(10) light quanta per flash. The technique suggests that large scale mapping of bioluminescence is feasible. PMID- 19873547 TI - Ionic Relations of Nitella translucens. AB - The ionic state of single internodal cells of a fresh water characean, Nitella translucens, has been studied. In mature cells the vacuolar concentrations were 78 mM K, 60 mM Na, and 151 mM Cl, compared with concentrations of 0.1 mM K, 1.0 mM Na, and 1.3 mM Cl in the bathing medium. The results suggest an active influx of potassium and an active efflux of sodium at the plasmalemma, and an active influx of chloride, probably at the tonoplast. The cation transport is inhibited by ouabain, and is more efficient in young cells; the chloride transport is insensitive to ouabain, and unaffected by age. Thus the two systems appear to be independent. It is suggested that the active fluxes are 0.5 to 0.6 micromicromoles K/cm(2) sec. inwards, and 0.45 micromicromoles Na/cm(2) sec. outwards. The passive influxes, 0.3 micromicromoles K/cm(2) sec. and 0.55 micromicromoles Na/cm(2)sec., give a value for the relative permeabilities of the plasmalemma, P(Na)/P(K), of 0.18. The absolute magnitudes of the permeabilities, compared with those derived from resistance measurements, suggest that potassium ions interact strongly in the membrane. The cation fluxes at the tonoplast are much higher than those at the plasmalemma. The active influx of chloride is 0.85 micromicromoles/cm(2) sec. in light, but only 0.052 micromicromoles/cm(2) sec. in the dark. The potassium influx is also reduced in the dark. Thus the energy for both active transport processes is closely geared to light-dependent metabolism, rather than to respiration. PMID- 19873548 TI - The Lens Effect and Phototropism of Phycomyces. AB - Normally, the dioptrics in air of the cylindrical sporangiophore of Phycomyces blakesleeanus confer on the distal side a focusing advantage of about 30 per cent for unilateral stimuli of parallel light. This advantage can be nullified or reversed to produce negative curvatures by means of diverging light stimuli. A thin cylindrical glass lens was positioned 0.15 mm from the light-adapted growing zone with its long axis parallel to the long axis of the sporangiophore. A 3 minute blue stimulus was given and the lens removed. Reproducible negative curvatures were observed with a maximum of 13 degrees occurring within 8 minutes after the beginning of the stimulus. Experiments in air were done in a water saturated atmosphere to minimize avoidance responses due to the proximity of the lens. The data support Buder's conclusion that the focusing advantage is the principal mechanism which produces the response differential necessary for phototropism. When the lens advantage is small, the attenuation becomes important in determining the direction of the response. Data obtained from sporangiophores immersed in inert liquids indicate that the attenuation is about 14 per cent. Therefore, whenever the focusing advantage is less than 14 per cent, negative curvatures are produced by unilateral stimuli. PMID- 19873549 TI - Specific Binding of Rubidium in Chlorella. AB - Specific binding sites for potassium, which may be components of the carriers for active transport for K in Chlorella, were characterized by their capacity to bind rubidium. A dense suspension was allowed to take up Rb(86) from a low concentration of Rb(86) and a high concentration of ions which saturate non specific sites. The amount bound was derived from the increase in the external concentration of Rb(86) following addition of excess potassium. The sites were heterogeneous. The average affinity of Rb and various other ions for the sites was determined by plotting the degree of displacement of Rb(86) against log molar concentration of the individual ions. Interpolation gave the concentration for 50 per cent displacement of Rb, which is inversely related to affinity. The order of affinity was not changed when the cells were frozen, or boiled either in water or in 70 per cent ethanol. The affinity is maximal for ions with a crystalline radius of 1.3 to 1.5 A and a high polarizability, and is not related to the hydrated radius or valency. It is suggested that binding groups in a site are rigidly arranged, the irregular space between them being 2.6 to 3.0 A across, so that affinity is high for ions of this diameter and high polarizability. PMID- 19873550 TI - The Chemistry of Sites Binding Rubidium in Chlorella. AB - The chemistry of sites that specifically bind Rb in Chlorella pyrenoidosa has been investigated by changing or modifying specific chemical groups or bonds in the cell and observing changes in binding capacity. Boiling the cells in water or in 70 per cent ethanol did not affect binding capacities of the sites. These results suggest that the integrity of the sites is independent of both hydrogen bonds and hydrophobic bonds, and that the sites, therefore, do not consist of a protein or protein-lipid complex. At 30 degrees C, both 1 M HCL and 0.5 to 1 M NaOH rapidly inactivated 70 per cent of the sites, but over a range of Ph 4.4 to 11.3, there was no effect. The sites are inactivated by strong chelating agents at 0.05 to 0.2 M and by reagents which reduce trivalent iron, and 4 to 10 atoms of iron per site are removed from the cells. Prolonged incubation in iron solutions, but not in solutions of Cu, Mn, or Mg, reversed to a considerable extent inactivation by EDTA. It is suggested that the sites probably bind trivalent iron tightly as chelation bridges which are essential to their structure. These structural bridges are broken when iron is removed by chelating agents or reduction, and are reformed in the presence of iron. Other experimental evidence indicates that amine, sulfhydryl, and carbonyl groups are not structural components of the sites. PMID- 19873551 TI - Changes in the Permeability of the Salivary Gland Caused by Sympathetic Stimulation and by Catecholamines. AB - The permeability of the submaxillary gland of cats and dogs has been tested by determining the rates at which non-electrolytes penetrate from the plasma into the saliva. Electrical stimulation of the cervical sympathetic trunk or administration of epinephrine or norepinephrine increases the permeability of the gland enabling glucose (molecular radius, MR = 3.5 A), sucrose (MR = 4.4 A), raffinose (MR = 5.6 A), polyglycol 1000 (MR = 7.2 A), and polyglycol 1540 (MR = 8.1 A) to penetrate into the saliva from which they are otherwise excluded. Inulin (MR = 14.7 A) does not enter the saliva under these circumstances. Analysis of the transfer rates suggests that the molecules diffuse through a pore structure permitting free diffusion for molecules with a radius less than 5.7 A. Close intraarterial injection of C(14)-glucose demonstrates that at least part of this permeability is located in the duct system of the gland. Since epinephrine does not enable sucrose to enter the cells of the gland, it appears that penetration from the extracellular space into the saliva occurs by diffusion through intercellular gaps. The characteristics of the permeability allow conclusions as to the localisation and geometry of the ultrastructural change produced. PMID- 19873552 TI - The Role of Potassium in Active Transport of Sodium by the Toad Bladder. AB - Studies were carried out on the isolated urinary bladder of the toad, Bufo marinus, in order to explain the dependence of active sodium transport on the presence of potassium, in the serosal medium. Attempts to obtain evidence for coupled sodium-potassium transport by the serosal pump were unsuccessful; no relation between sodium transport and uptake of K(42) from the serosal medium was demonstrable. Rather, the predominant effect of serosal potassium appeared to be operative at the mucosal permeability barrier, influencing the permeability of this surface to sodium. The mucosal effects of serosal potassium were correlated with effects on cellular cation content. When sodium Ringer's solution was used as serosal medium, removal of potassium resulted in significant decrease in tissue potassium content, commensurate increase in tissue sodium content, and marked depression of mucosal permeability and sodium transport. When choline replaced sodium in the serosal medium, removal of potassium resulted in only slight alterations of tissue electrolyte content, and effects on mucosal permeability and sodium transport were minimal. PMID- 19873553 TI - Electrical Interaction of Paired Ganglion Cells in the Leech. AB - The two paired giant ganglion cells (PGC's) found in each ganglion of the leech central nervous system fire synchronously in response to certain sensory input. Polarizing current passed into either of these cells is seen to displace the membrane potentials of both cells, the voltage attenuation between the two somata ranging from 2 to 5 times. This attenuation factor remains unchanged when the direction of the polarizing current is reversed, and remains about the same when the other cell of the pair is directly polarized. When one of the PGC's is partially depolarized with outward current, a repetitive train of impulses is generated. Each spike is followed by a spike in the other cell. Occasionally, a small subspike potential is seen in place of a follower spike. This potential appears to differ in shape and time course from synaptic potentials elicited by afferent input to these cells, and appears rather to be an electrotonic potential derived from the prejunctional impulse in the stimulated PGC. It is proposed that transmission between these cells is electrical, being accomplished by a flow of local circuit current across a non-rectifying junction or connection to the spike initiating region of the other PGC. PMID- 19873554 TI - The Coupling of the Short-Circuit Current to Metabolism in the Urinary Bladder of the Toad. AB - The relationship of the short-circuit current to metabolism was studied in the toad bladder in vitro. Substrates and inhibitors were added to the bathing medium and the effect on the short-circuit current was determined. The spontaneous decline in the short-circuit current that occurred in substrate-free media was prevented or reversed by the addition of glucose, pyruvate, lactate, or beta hydroxybutyrate, whereas acetate and tricarboxylic acid cycle intermediates had no effect. A variety of metabolic inhibitors depressed the short-circuit current; depression by iodoacetate and by malonate was delayed by prior addition of pyruvate or lactate but not by glucose. The ability of a substrate to stimulate the current did not correlate with its rate of oxidation to CO(2). On the basis of earlier studies, the metabolic effects on the short-circuit current were assumed to reflect equivalent effects on the rate of active Na transport. It is suggested that the energy for Na transport is provided not by a general cellular metabolic pool but by a specific metabolic pathway or pathways spatially linked to the transport mechanism. PMID- 19873555 TI - Studies of the Origin of Bacterial Viruses : VII. The effect of various mutagens (urethane, ethyl urethane, hydrogen peroxide, desoxycholate, maleic hydrazide, butadiene dioxide, triethylene melamine, versene, and acriflavine) on the proportion of virus-producing and streptomycin-resistant cells in cultures of B. megatherium 20delta. AB - The mutagens, urethane, ethyl urethane, hydrogen peroxide, desoxycholate, versene, maleic hydrazide, butadiene dioxide, and triethylene melamine, all increase the proportion of virus-producing cells and streptomycin-resistant cells in B. megatherium 20delta cultures to about the same extent. Acriflavine has no effect on the proportion of either type of cell. Triethylene melamine appears to cause mutations to occur without cell division. PMID- 19873556 TI - Osmotic Behavior of Oat Coleoptile Tissue in Relation to Growth. AB - Efforts were made to estimate the water potential difference that is required, between rapidly growing oat coleoptile cylinders and dilute medium, to support the rate of water uptake involved in elongation, (a) by the traditional method of determining the concentration of mannitol in which the tissue neither gains nor loses water, and (b) by measuring the rates of osmotic exchanges induced by treating the tissue with different hypotonic mannitol concentrations. Both methods indicated large water potential differences (3 to 10 atm), in some cases approaching the osmotic pressure of the cells. However, indication was obtained that the rates of osmotic exchanges induced by mannitol solutions, and presumably also the equilibrium response sought in (a), are governed by the rate of diffusional exchange of mannitol with the free space rather than by the permeability of the tissue to water. Osmotic swelling of the tissue measured by immersing it in water after its turgor pressure had been reduced by evaporation, was at least two to four times more rapid than when mannitol was involved. The permeability to water estimated by the evaporation-immersion method indicated that rapidly elongating cylinders have water potentials between -0.8 and -2.5 atm, or between 10 and 25 per cent of their osmotic pressure. PMID- 19873557 TI - Factors Affecting the Fluxes of Potassium and Chloride Ions in Nitella translucens. AB - A more complete study of ionic concentrations and fluxes in the giant internodal cells of Nitella translucens has been made. The vacuolar concentrations were 76 mM K and 170 mM Cl. The content of the chloroplast layer was 135 mmicromoles K/cm(2) and 215 mmicromoles Cl/cm(2); in a layer 9 micro thick these correspond to concentrations of 150 mM K and 240 mM Cl. Such a high level of chloride requires active transport of chloride into the cytoplasm, either at the plasmalemma or at the membranes bounding the cytoplasmic particles; it cannot be achieved by active transport of chloride only at the tonoplast. With concentrations of 0.1 mM K and 1.3 mM Cl outside, the fluxes into the cytoplasm had mean values of 1.0 to 1.4 micromicromoles K/cm(2)sec. and 2.1 to 2.8 micromicromoles Cl/cm(2)sec.; the corresponding fluxes from the cytoplasm to the vacuole were about 110 micromicromoles K/cm(2)sec. and 175 micromicromoles Clcm(2)sec. The transfer of both potassium and chloride to the vacuole under different conditions appeared to be correlated with the uptake of chloride into the cytoplasm. It is suggested that two separate processes are involved in the active accumulation of salts in the vacuole-an active uptake of chloride in the cytoplasm and a subsequent transfer of salt to the vacuole. It may be that the second process involves the formation of small vesicles in the cytoplasm and their subsequent discharge into the central vacuole. PMID- 19873558 TI - Equilibrium and Ion Exchange Characteristics of Potassium and Sodium Accumulation by Barley Roots. AB - Potassium ion and Na(+) influx and efflux rates into and from excised barley roots are compared with the maximum capacity of accumulation. Potassium ion and Na(+) influx and efflux involve a cation exchange that is independent of simultaneous exchange of the accompanying anion. These exchange fluxes depend on the concentration and cation composition of the solutions from which they originate. Selective differences between K(+) and Na(+) fluxes are sufficient to account for a cationic distribution within the roots that differs markedly from that of the external solution and that persists for extended time periods. The accumulation maximum is a cation exchange equilibrium with the cation influx and efflux rates approaching equality. The equilibrium level is independent of the individual cation fluxes and the external solution concentration. It is a finite quantity which appears to be determined by the internal anion concentration including accumulated as well as endogenous anions. PMID- 19873559 TI - Na and K Fluxes in Nitella clavata. AB - Na and K influxes and effluxes, membrane potentials, and cell ion concentrations of Nitella clavata were measured as functions of external NaCl concentrations and time. It appears necessary to conclude that active K transport into the cells as well as active Na extrusion is present, although the latter is of small magnitude and possibly is explicable as exchange-diffusion. An attempt has been made to account for the capacity of the cells to discriminate between K and Na ions and yet have fairly independent passive ion movements. This is done by proposing a model in which the permeation areas are "slit-pores" rather than cylindrical pores. The slit-pores would permit rather independent movements of ions within them so long as the pores do not tend to become saturated from both or either side. In the latter case one way movement results. The experimental results are in fair agreement with this suggested model. PMID- 19873560 TI - Cell and Solution Velocity Constants for the Reaction CO + Hb --> COHb at Different Temperatures in Mammals with Different Red Cell Sizes. AB - Using a double beam stopped-flow apparatus, measurements were made of the velocity constant of the reaction CO + Hb --> COHb in solution and in the red cells of human beings, rabbits, horses, and goats. The solution constant (l') at 37 degrees C for human beings was 362 mM(-1) sec.(-1); in other species l' was somewhat lower. Two rabbits, despite having apparently identical hemoglobins had significantly different values for l'. The energy of activation (E) of l' was between 8 and 11 kcal/mole in all cases. The cell reaction constant (l'(c)) at 37 degrees was between 61 and 73 mM(-1) sec.(-1) in all cases; at 37 degrees the trend was for the smaller cells to have the higher l'(c). This cell size effect was much less than previously found for the faster oxygen reaction. This showed that by merely increasing the rate of chemical reaction, it was not possible to increase cell uptake rate beyond a certain level, this level being dependent on the size and membrane properties of the cell. At lower temperatures l' was a more important factor in determining l'(c) than was cell size. The cell membrane was a barrier to gas diffusion in all species. The effect of temperature on l'(c) was also measured and was less than its effect on l' at most temperatures. Temperature effect increased in small cells at low temperatures. Both these findings are in accordance with predictions based on differentiation of Roughton's equations. PMID- 19873561 TI - Cation Transport in Escherichia coli: V. Regulation of cation content. AB - Measurement of cellular K and Na concentrations in growing Escherichia coli indicates that the osmololity of the medium is a major determinant of the cell K concentration. In contrast, the cell Na concentration is independent of the medium osmolality and is largely dependent on the Na concentration of the medium. Sudden changes in the osmolality of the medium lead to rapid changes in K content. Washing the cells with solutions of lower osmolality results in a very rapid loss of K, which is greater in more dilute and in cold solutions. A sudden increase in the osmolality of the growth medium produces a rapid uptake of K by a mechanism whose rate is a saturable function of the K concentration of the medium and which appears to involve an exchange of K for cellular H. PMID- 19873562 TI - Sugar Transport and Metal Binding in Yeast. AB - The uptake of sugars by yeast can be separated into two classes. The first involves the uptake of sorbose or galactose by starved cells, and the uptake of glucose by iodoacetate-poisoned cells. These uptakes do not involve any changes in Ni(++)- or Co(++)-binding by the cell surface, are not inhibited by Ni(++), are inhibited by UO(2) (++) in relatively high concentrations, are characterized by high Michaelis constants and low maximal rates and by a final equilibrium distribution of the sugars. The second involves the uptake of glucose in unpoisoned cells and galactose in induced cells. These uptakes are characterized by a reduction of Ni(++)- and Co(++)-binding, by a partial inhibition by Ni(++), by an inhibition with UO(2) (++) in relatively low concentrations, and by a low Km and a high Vm. In the case of galactose in induced cells, previous studies demonstrate that the sugar is accumulated against a concentration gradient. It is suggested that the first class of uptakes involves a "facilitated diffusion" via a relatively non-specific carrier system, but the second represents an "uphill" transport involving the highly specific carriers, and phosphoryl groups (cation binding sites) of the outer surface of the cell membrane. PMID- 19873563 TI - The Gustatory Neural Response Function. AB - With few exceptions, afferent neurons in the various sensory systems respond to wide ranges of stimuli. In those sensory systems for which the stimulus dimensions are understood, the response functions of these neurons may be described; they are usually simple functions with one maximum, although many variations exist. In the chemical senses, the stimulus dimensions are not known, and thus the neural response functions of these neurons have never been described. The present paper presents methods to determine these response functions and the stimulus dimensions for the chemical senses. A tentative response function for taste is developed, and preliminary steps are taken toward disclosing the stimulus dimensions. PMID- 19873564 TI - Do Flies Have A Red Receptor? AB - (1) The compound eye of Musca exhibits characteristics which have heretofore frequently been considered evidence for color receptors: (a) The spectral sensitivity curve has several peaks whose relative heights can be altered by selective adaptation to colored lights, and (b) the shape of the retinal action potential varies with wave length. (2) The action spectrum for the red enhancement of on and off responses is compared with the "red receptor" calculated by Mazokhin-Porshnyakov from colorimetric data obtained in rapid color substitutions. Both have maxima at 615 to 620 mmicro and appear to be different expressions of the same phenomenon. (3) A red receptor is absent. The evidence which suggests different types of receptors in the region 500 to 700 mmicro can be accounted for by variations in the numbers of receptors stimulated. In red light there is a recruitment of additional ommatidia caused by leakage of long wave lengths through the pigment screen, and this spatial summation potentiates the on and off responses. The principal evidence is: (a) a white eye mutant which has no accessory screening pigments also lacks the peak of sensitivity in the red, even when adapted to violet light; (b) white-eyed flies give identical responses with large on and off effects at all wave lengths from 500 to 700 mmicro; and (c) reducing the number of excited ommatidia by decreasing the size of the test spot makes the on and off transients smaller relative to the receptor component. PMID- 19873565 TI - The Components of the Visual System of a Dragonfly. AB - In this study of the electroretinograms of dragonflies (adults and nymphs) the objectives were to determine the number of classes of photoreceptors present in the visual system and to allocate these to particular morphological regions. There are probably five classes of photoreceptors present with peak sensitivities near 550, 530, 518, 420, and < 380 mmicro. The dorsal ocelli contain two classes (518 mmicro and < 380 mmicro). The ventral (anterior) ommatidia of the adult compound eye contain at least two classes (near 518 mmicro and < 380 mmicro) and probably a third class (near 550 mmicro). The dorsal ommatidia of the adult compound eye contain one class (420 mmicro) and possibly another class (< 380 mmicro). The compound eye of the nymph contains one class (530 mmicro) and possibly another class (420 mmicro). PMID- 19873566 TI - Analysis of Spike Electrogenesis and Depolarizing K Inactivation in Electroplaques of Electrophorus electricus, L. AB - Voltage clamp analyses, combined with pharmacological tools demonstrate the independence of reactive Na and K channels in electrically excitable membrane of eel electroplaques. Spike electrogenesis is due to Na activation and is eliminated by tetrodotoxin or mussel poison, or by substituting choline, K, Cs, or Rb for Na in the medium. The K channels remain reactive, but K activation is always absent, the electroplaques responding only with K inactivation. This is indicated by an increased resistance when the membrane is depolarized by more than about 30 mv. The resting resistance (1 to 5 ohm cm(2)) is dependent upon the ionic conditions, but when K inactivation occurs the resistance becomes about 10 ohm cm(2) in all conditions. K inactivation does not change the EMF significantly. The transition from low to high resistance may give rise to a negative-slope voltage current characteristic, and to regenerative inactivation responses under current clamp. The further demonstration that pharmacological K inactivation (by Cs or Rb) leaves Na activation and spike electrogenesis unaffected emphasizes the independence of the reactive processes and suggests different chemical compositions for the membrane structures through which they operate. PMID- 19873567 TI - The Electrophysiological Organization of the Embryonic Chick Heart. AB - Both intracellular and surface electrodes were employed to record electrical activity from embryonic chick hearts between the ages of 3 and 20 days. Cells from the sinus venosus, sinoatrial (SA) valves, atrium, atrioventricular (AV) ring, and ventricle were localized and characterized on the basis of shape, amplitude, rise time, and duration of transmembrane potentials. The differences in transmembrane potentials from these various regions provided the basis for a hypothesis concerned with the distribution of pacemaker potentiality and one related to the origin of the His-Purkinje system. Action potentials recorded along the entire embryonic AV ring were comparable to those of the adult rabbit AV nodal cells in both configuration and sequence of activation and were thus categorized into three functional regions (AN, N, NH). Histological sections of 7 and 14 day hearts demonstrated muscular continuity between the right atrium and ventricle across the muscular AV valve. PMID- 19873569 TI - On the Colors of Visual Pigment Chromophores. PMID- 19873568 TI - The Spread of Excitation in the Embryonic Chick Heart. AB - The spread of excitation in embryonic chick hearts, ranging in age from 7 to 20 days, was studied with both intracellular and extracellular electrodes. Evidence that the delay in ventricular excitation could be attributed to the cells of the entire atrioventricular (AV) ring was obtained, in part, from sagittal sections of the heart. In the intact preparation, uniform propagation occurred throughout the atrial roof at an apparent conduction velocity of 0.4 to 0.5 meter/sec. Delay of impulse propagation was localized in a very narrow band of tissue which extended across the AV ring. The apparent conduction velocity of this tissue was between 0.003 and 0.005 meter/sec. Both normal and retrograde propagation revealed the spread of conduction across the AV ring to be decremental in nature. This finding was supported by high frequency stimulation experiments which gave rise to AV block localized in the cells of the AV ring. Cardiac rhythmicity and AV transmission were responsive to acetylcholine and norepinephrine in much the same manner as in the adult mammalian heart. The present findings are in support of the hypothesis that the embryonic AV ring is the functional counterpart of the adult AV node. PMID- 19873570 TI - Absorption of Musca domestica Screening Pigment. PMID- 19873571 TI - Problems of an RNA Genome Operating in a DNA-Dominated Biological Universe. PMID- 19873572 TI - Polysaccharide biosynthesis. AB - Polysaccharide synthesis is discussed from the point of view of the sources of biological information that determine the structures and control the rates of synthesis of complex polysaccharides. It is concluded that three types of information contribute in important and different ways, namely enzyme specificity, primer substances, and the structure of the cytoplasmic membrane. Each of these factors is discussed in a general way with examples of its contribution to the structure and organization of specific polysaccharides. PMID- 19873573 TI - Quantum requirement for photosynthesis in chlorophyll-deficient plants with unusual lamellar structures. AB - Neither an over-all deficiency of chlorophyll, nor an increased enzymatic capacity for maximal rates, nor an unusual lamellar structure was found to change the number of quanta required for the evolution of one molecule of oxygen in healthy aurea mutants of tobacco. The average minimal quantum number remains 10 (efficiency 0.1) as in many algae and typical higher plants. Most of the time the optimal efficiency depends on the availability of some far-red radiation, particularly in the blue region of the spectrum where blue light alone is rather inefficient. These results fit an explanation offered earlier in connection with the hydrogen or acetate photometabolism of algae in far-red light. PMID- 19873574 TI - The mode of transverse spread of contraction initiated by local activation in single crayfish muscle fibers. AB - Isolated single crayfish muscle fibers were locally activated by applying negative current pulses to a pipette whose tip was in contact with the fiber surface. The contraction initiated by a moderate depolarization spread inwards in a graded manner according to the magnitude and duration of depolarization. Increase of the depolarized area increased the distance of the inward spread for a given amount of depolarization. If a large area of the surface membrane was depolarized with a large pipette for a sufficiently long time, the contraction spread not only inwards, but further transversely passing through the center of the fiber. Successive brief depolarizations given at an appropriate interval could produce contraction more effectively for a given amount of total current than did a prolonged depolarization. On the other hand, the contraction initiated by a strong negative current was observed to spread around the whole perimeter but not through the center of the fiber. Each type of local contraction always spread along the striation pattern and not longitudinally. Possible mechanisms of these responses are discussed in connection with the transverse tubular system of the muscle fibers. PMID- 19873575 TI - The wave form of luminescence emitted by noctiluca. AB - The wave shape, intensity, and time course of the flash were examined with the aid of electronic operations in order to characterize the luminescence response and examine the in vivo dynamics of the light reaction. The most prominent single component of the flash shape is its exponential decay, beginning several milliseconds after the intensity maximum, with a mean rate constant at 23 degrees C of -0.088 msec(-1). Earlier components of the flash curve are more complex, exhibiting no pure exponentials with time. As predicted from previous observations, the time course of the flash triggered by a propagated action potential, and therefore influenced by the conduction time of the triggering potential, is measurably slower than that of the synchronously triggered flash. The time course of emission from individual specimens is otherwise quite stable, undergoing only limited slowing with short-interval fatigue or specimen deterioration in spite of marked changes in the amplitude of the wave form. Relative stability of amplitude is obtained when flashes are elicited at regular intervals greater than 10 sec. On the basis of an analogue computer simulation (Appendix) the dynamics of the luminescence wave shape were found to be compatible with a short sequence of first order processes acting on an initial brief transient. PMID- 19873576 TI - Membrane watching. PMID- 19873577 TI - Dynamic asymmetries in the squid axon membrane. PMID- 19873578 TI - Permeability of the Giant Axon of Dosidicus gigas to Calcium Ions. PMID- 19873580 TI - An experimental approach to determine membrane charges in squid giant axons. PMID- 19873579 TI - Water flux and electrokinetic phenomena in the squid axon. PMID- 19873581 TI - Ion fluxes in dialyzed squid axons. PMID- 19873582 TI - Some factors affecting sodium outflux in internally dialyzed squid axons. PMID- 19873583 TI - Coupling and selectivity of sodium and potassium transport in squid giant axons. PMID- 19873585 TI - Recent experiments on the properties of the na efflux from squid axons. PMID- 19873584 TI - The loss and recovery of the sodium pump in perfused giant axons. PMID- 19873586 TI - The role of calcium in the processes of excitation and contraction in skeletal muscle. PMID- 19873587 TI - Voltage clamp experiments in striated muscle fibers. PMID- 19873588 TI - Structural studies of cell membrane preparations. PMID- 19873589 TI - The role of the electrochemical gradient in determining potassium fluxes in frog striated muscle. PMID- 19873590 TI - Membrane potential and chemical transmitter in active transport of ions by rat skeletal muscle. PMID- 19873591 TI - Correlations between Electron Microscopic and Physiological Observations in Heart Muscle. PMID- 19873592 TI - The thermodynamics of nerve and electric organ. PMID- 19873593 TI - Ionic permeability and water movement in frog gastric mucosa. PMID- 19873595 TI - Observations on ionic movement through the gastric mucosa. PMID- 19873594 TI - Utilization of high-energy phosphate compounds by stomach. PMID- 19873596 TI - The metabolic state and the response of the potential of frog gastric mucosa to changes in external ion concentrations. PMID- 19873597 TI - Experimental and theoretical data on excitable artificial lipidic membranes. PMID- 19873598 TI - Bioelectric properties and ionic content in toad bladder. PMID- 19873599 TI - On the stimulation of sodium transport by aldosterone. PMID- 19873600 TI - Fluxes and Distribution of Sodium in Frog Skin : A new model. PMID- 19873601 TI - Intracellular redistribution of sodium and calcium during stimulation of sodium transport in epithelial cells. PMID- 19873602 TI - Sodium and water transport in kidney proximal tubular cells. PMID- 19873603 TI - Some electrical properties of single renal tubule cells. PMID- 19873605 TI - Characterization of biological membranes by equivalent pores. PMID- 19873604 TI - The effect of calcium ions on the steady-state ionic distribution in kidney cortex cells. PMID- 19873606 TI - Effects of fluoride on potassium and sodium permeability of the erythrocyte membrane. PMID- 19873607 TI - X-ray study of model systems: structure of the lipid-water phases in correlation with the chemical composition of the lipids. PMID- 19873608 TI - The effects of macrocyclic compounds on cation transport in sheep red cells and thin and thick lipid membranes. PMID- 19873609 TI - The Relation between Ouabain-Sensitive Potassium Efflux and the Hypothetical Dephosphorylation Step in the "Transport ATPase" System. PMID- 19873610 TI - Ultrastructural studies of the squid nerve fibers. PMID- 19873611 TI - Transport of electrolytes in the schwann cell and location of sodium by electron microscopy. PMID- 19873612 TI - Mechanism of the schultz-dale reaction in the denervated diaphragmatic muscle of the Guinea pig. AB - The mechanism of the contractions elicited by specific antigens in immunologically sensitized muscle tissue (Schultz-Dale responses) has been investigated on single fibers of denervated guinea pig hemidiaphragms. This preparation can be either actively or passively allergized, showing Schultz-Dale responses similar to those of visceral muscle. Specific antigens were applied with an electrically operated microtap to discrete areas of the cell surface while recording the electrical activity with intracellular microelectrodes. In this manner, a depolarizing action of the antigens on the muscle membrane was demonstrated. Brief applications of antigen gave rise to phasic potential changes (antigen potentials) similar to those elicited in the same fibers with acetylcholine-filled microtaps. However, antigen potentials occur only in denervated fibers sensitized to the specific antigen or closely related proteins; they are not seen in either innervated fibers of allergized animals or in denervated, nonallergized fibers. Repeated antigen application to the same area of the fiber causes a local irreversible desensitization. The antigen potentials are associated with a reduction in the resistance of the muscle membrane, similar to that caused by acetylcholine. It is concluded that besides causing the liberation of biogenic amines from the mast cells, antigens exert a direct action on the permeability of the muscle membrane; the molecules of antibody adsorbed to the cells appear to act as specific chemoreceptors for the antigen. PMID- 19873613 TI - Protein and RNA Metabolism of Squid Axons (Dosidicus gigas). PMID- 19873614 TI - Myelin: dynamic or stable? PMID- 19873615 TI - Equivalent pore radius of the axolemma of resting and stimulated squid axons. PMID- 19873616 TI - Neuroactive agents and nerve membrane conductances. PMID- 19873617 TI - Dynamic processes in soap films. AB - Some relations between the two main types of thin liquid films, the water-in-air "soap" films and the invert oil-in-water "lipid" films, are outlined, and several dynamic aspects of film behavior are illustrated and briefly reviewed with reference to more complete treatments. These dynamic processes are important in both types of films, but are easier to study in soap films. The topics include the difference between rigid and mobile films and their interconversion; the origin and measurement of film elasticity; the effect of rate of formation upon film thickness, and the evidence against the existence of thick rigid water layers at the surface; and the kinetics of drainage and the role played in it by viscous flow, marginal regeneration, and intermolecular forces. PMID- 19873618 TI - Black Lipid Membranes at Bifaces : Formation characteristics, optical and some thermodynamic properties. AB - Black lipid membranes (BLM) less than 90 A thick have been shown to be the most realistic approach to biological membrane models. This paper describes the formation characteristics, optical properties, and thermodynamics of BLM at water/oil/water bifaces. In particular, the nature of the Plateau-Gibbs border which supports the black membrane is analyzed in some detail. The formation of BLM at the biface involves a spontaneous reduction of the free energy of the system. As long as the integrity of the membrane is maintained, the limiting structure of the BLM represents the lowest free energy configuration. PMID- 19873619 TI - Permeability and electrical properties of thin lipid membranes. AB - We present and discuss the permeability and electrical properties of thin lipid membranes, and the changes induced in these properties by several agents added to the aqueous phases after the membranes have formed. The unmodified membrane is virtually impermeable to ions and small "hydrophilic" solutes, but relatively permeable to water and "lipophilic" molecules. These properties are consistent with those predicted for a thin film of hydrocarbon through which matter is transported by dissolving in the membrane phase and then diffusing through it. The effect of cholesterol in reducing the water and "lipophilic" solute permeability is attributed to an increase of the "viscosity" of the hydrocarbon region, thus reducing the diffusion coefficient of molecules within this phase. The selective permeability of the membrane to iodide (I(-)) in the presence of iodine (I(2)) is attributed to the formation of polyiodides (perhaps I(5) (-)), which are presumed to be relatively soluble in the membrane because of their large size, and hence lower surface charge density. Thus, I(2) acts as a carrier for I(-). The effects of "excitability-inducing material" and the depsipeptides (particularly valinomycin) on ion permeability are reviewed. The effects of the polyene antibiotics (nystatin and amphotericin B) on ion permeability, discussed in greater detail, are the following: (a) membrane conductance increases with the 10th power of nystatin concentration; (b) the membrane is anion-selective but does not discriminate completely between anions and cations; (c) the membrane discriminates among anions on the basis of size; (d) membrane conductance decreases extraordinarily with increasing temperatures. Valinomycin and nystatin form independent conductance pathways in the same membrane, and, in the presence of both, the membrane can be reversibly shifted between a cation and anion permeable state by changes in temperature. It is suggested that nystatin produces pores in the membrane and valinomycin acts as a carrier. PMID- 19873620 TI - The structure of a model membrane in relation to the viscoelastic properties of the red cell membrane. AB - The molecular arrangement within a lamellar structure composed of human erythrocyte lipids is determined. The 45 A thick lipid layer, in water, is filled in the interior with a liquid-like configuration of the hydrocarbon chains of phospholipid molecules and is covered on both sides by their hydrophilic polar groups. Cholesterol is located so that part of its steroid nucleus is between the polar groups of the phospholipid molecules while the rest of the molecule extends into the inner hydrocarbon layer. This lipid leaflet would be expected to have the mechanical properties of a purely liquid surface, as other authors have shown for the "black" lipid membranes. Data are presented which demonstrate that the intact erythrocyte membrane is a tough viscoelastic substance with a Young's modulus of 10(6)-10(8) dynes/cm(2) and a viscosity of 10(7)-10(10) poises. The parameters and the kinetics of membrane breakdown are incompatible with the model system of pure lipid. Caution must be exercised in applying various data on the model systems to intact membranes. PMID- 19873621 TI - Monolayer and interfacial permeation. AB - Transport across physical-chemical interfaces is considered in connection with three particular problems of biological interfaces: the structure and properties of cell membranes, the properties of the lung surfactant, and the effects of ionic currents across excitable membranes. With regard to cell membranes, studies of monolayer permeation suggest that permselectivity on the basis of size is a property of bilayer structure and probably gives rise to the observed dependence of the permeability on partition coefficients. The permeabilities of lipid and protein monolayers are consistent with the bimolecular leaflet (BML) model of the membrane and not with mosaic models. Experiments with the lung surfactant indicate that, in addition to its surface tension-lowering properties, it is unusual in its ability to form a strong two-dimensional network, which probably contributes to alveolar stability. Finally, the results of studies of interfacial ionic transference suggest a new way of accounting for the ionic fluxes in excitable membranes during an action potential without assuming ion-selective pores or carriers. In the suggested mechanism, it is possible to account for the change in ionic selectivity and the proper phasing of the fluxes, as well as other aspects of excitation in natural membranes. PMID- 19873622 TI - Ion Transport through Monolayers and Interfacial Films. AB - Ion transport through monolayers and through several molecules of thick films at the mercury/water interface is discussed. The permeability of the monolayer is described by a rate constant, k(c). The permeability of a thin but not monomolecular film is expressed as a function of the thickness of the film, the diffusion coefficient of the permeant in the film, and the distribution coefficient between the film and the bulk of the solution. The rate constant k(c) is expressed in terms of absolute rate processes. In the absence of specific interactions, the activation energy is composed of three terms: (a) electrostatic interaction between the permeating ion and the charged monolayer, (b) monolayer compression work of forming a hole for passage of the ions, and (c) energy of boundary line formation between the monolayer and the hole. The contribution of the third term is especially marked in condensed monolayers. Ions are bound weakly to the monolayers of the dipolar ion lecithin, which complicates the transport problem in this system. The retardation of oxygen reduction by the lecithin monolayer is of particular interest. PMID- 19873623 TI - Lytic agents, cell permeability, and monolayer penetrability. AB - Cell lysis induced by lytic agents is the terminal phase of a series of events leading to membrane disorganization and breadkdown with the release of cellular macromolecules. Permeability changes following exposure to lytic systems may range from selective effects on ion fluxes to gross membrane damage and cell leakage. Lysis can be conceived as an interfacial phenomenon, and the action of surface-active agents on erythrocytes has provided a model in which to investigate relationships between hemolysis and chemical structure, ionic charge, surface tension lowering, and ability to penetrate monolayers of membrane lipid components. Evidence suggests that lysis follows the attainment of surface pressures exceeding a "critical collapse" level and could involve membrane cholesterol or phospholipid. Similarities of chemical composition of membranes from various cell types could account for lytic responses observed on interaction with surface-active agents. Cell membranes usually contain about 20-30 % lipid and 50-75 % protein. One or two major phospholipids are present in all cell membranes, but sterols are not detectable in bacterial membranes other than those of the Mycoplasma group. The rigid cell wall in bacteria has an important bearing on their response to treatment with lytic agents. Removal of the wall renders the protoplast membrane sensitive to rapid lysis with surfactants. Isolated membranes of erythrocytes and bacteria are rapidly dissociated by surface-active agents. Products of dissociation of bacterial membranes have uniform behavior in the ultracentrifuge (sedimentation coefficients 2-3S). Dissociation of membrane proteins from lipids and the isolation and characterization of these proteins will provide a basis for investigating the specificity of interaction of lytic agents with biomembranes. PMID- 19873624 TI - Structure and Function of the Plasma Membrane : A biochemical perspective. AB - The paucimolecular unit membrane model of the structure of the plasma membrane is critically reviewed in relation to current knowledge of the chemical and enzymatic composition of isolated plasma membranes, the properties of phospholipids, the chemistry of fixation for electron microscopy, the conformation of membrane proteins, the nature of the lipid-protein bonds in membranes, and possible mechanisms of transmembrane transport and membrane biosynthesis. It is concluded that the classical models, although not disproven, are not well supported by, and are difficult to reconcile with, the data now available. On the other hand, although a model based on lipoprotein subunits is, from a biochemical perspective, an attractive alternative, it too is far from proven. Many of the questions may be resolved by studies of membrane function and membrane biosynthesis rather than by a direct attack on membrane structure. PMID- 19873625 TI - Biochemical studies on active transport. AB - The active transport process, so important in cell function, has been studied in the past with intact cells. Models which have arisen from this work all depend on: first, a specific protein to recognize the substrate; second, translocation of the substrate across the cell membrane; third, release of substrate within the cell and restoration of the system to its initial state. These steps are adequate for facilitated transport, but in active transport an energy input is required to maintain a concentration gradient. Parts of transport systems have been isolated recently. A protein which specifically recognizes beta-galactosides has been partially purified. In another case, a protein that appears to be the recognition part of the sulfate transport system of Salmonella typhimurium has been crystallized, and many of its properties have been described. The role of this protein in recognition and in translocation is discussed. Also proteins that phosphorylate a variety of sugars as they enter the cell's interior provide a mechanism for concentrating sugars as their phosphates, against a gradient. PMID- 19873626 TI - Dynamics of transcapillary fluid exchange. AB - Fluid balance at the capillary level has been simulated with an analogue computer program, based on experimental data on regional differences in capillary permeability, surface areas, and hydrostatic pressures. The program takes into account fluid and protein fluxes into and out of the interstitial space. Solutions are obtained for tissue hydrostatic pressure, tissue fluid osmotic pressure, interstitial space volume, and lymph flow. Simulation of a variety of physiological experiments and clinical disease states has yielded reasonable agreement between experimental data and data obtained by computer analysis. Dilution of the interstitial plasma protein pool with a consequent reduc6tion of its oncotic pressure appears to be a major factor, which prevents edema unless plasma oncotic pressures are reduced by 10-15 mm Hg or, alternatively, venous pressures are elevated by a similar amount. The computer analysis in all instances yields positive values for tissue pressure, in agreement with experimental data obtained by needle puncture. The negative tissue pressures observed in subcutaneous capsules can be reproduced in the computer program, if the interface between the capsule and the surrounding interstitial space is assumed to have the properties of a semipermeable membrane. PMID- 19873627 TI - Mediated (nonactive) transport of glucose in Mammalian cells and its regulation. AB - Mediated (nonactive) transport of glucose in mammalian cells is characterized by saturation kinetics, stereospecificity, sensitivity to inhibition by phlorizin and certain sulfhydryl-blocking agents, a temperature coefficient of about 2, an inability to utilize metabolic energy, and countertransport. Countertransport can be explained by the development of carrier gradients in the cell membrane and provides the best evidence for carrier mobility. Efforts to identify and isolate chemical components of the transport system, have not been successful. Transport among different types of mammalian cells shows a wide range of activities (V(max) values differ by three or more orders of magnitude) and different sensitivities to hormones. Glucose enters the liver cell by mediated transport, as shown by a difference in the penetration rates of D- and L-glucose and sensitivity to phlorizin. The activity of the system is one of the highest known. Transport in muscle is the most important rate-controlling step for glucose utilization and is strongly accelerated by hypoxia, work, and insulin. The effect of work or insulin is strongly inhibited by metabolism, of fatty acids. Insulin also stimulates glucose transport in adipose tissue. Using isolated fat cells, it could be shown that insulin is rapidly bound to sites on the cell surface. The effect is lost within a few minutes after the exogenous hormone is removed. The bound insulin is not released as such, but is metabolized to unknown products. Binding is prevented by preexposure of cells to maleimide, which presumably blocks certain sulfhydryl groups at or near the insulin-binding site. Pretreatment with insulin protects against maleimide. Digestion of the cell with trypsin eliminates the acceleration of glucose transport and the inhibition of lipolysis by insulin. The glucose transport and adenyl cyclase systems are not grossly affected by trypsin, indicating that the insulin effector system is a separate entity. PMID- 19873628 TI - The microrheology of red blood cell suspensions. AB - The general problem of microrheology is to predict the macroscopic flow properties of a material from a detailed description of the behavior of its constituent elements. This approach has been used to study suspensions of human red cells in plasma or Ringer's solution flowing steadily in rigid tubes 8-25 times the red cell diameter by observing individual cell motions under the microscope. The results have been compared with those previously obtained with model particles under similar conditions. In very dilute suspensions single red cells rotated in orbits similar to those of rigid discs at low flow rates, but, in common with model deformable particles, were observed to migrate away from the tube wall. Linear rouleaux of red cells rotated as rodlike particles and were flexible, bending during their rotational orbits in a manner similar to that of filaments of nylon or Dacron. Transparent concentrated suspensions were produced by preparing ghost cells reconstituted in biconcave form in plasma. In these, the motions of some unhemolyzed red cells were followed. The erythrocyte velocity profiles were blunted at concentrations above 20%; the cell paths were erratic because of frequent radial displacements, especially at the tube periphery, with the particles being markedly deformed and oriented parallel to the flow. Finally, the difference in flow pattern in large and small vessels is discussed and some relevant model experiments are described. PMID- 19873629 TI - The ultrastructural basis of transcapillary exchanges. AB - A brief survey is given of current views correlating the ultrastructural and permeability characteristics of capillaries. Observations based on the use of peroxidase (mol wt 40,000), as an in vivo, and colloidal lanthanum, as an in vitro, ultrastructural tracer, are presented. In capillaries with "continuous" endothelium, the endothelial intercellular junctions are thought to be permeable to the tracers, and are regarded as maculae occludentes rather than zonulae occludentes, with a gap of about 40 A in width between the maculae. Some evidence for vesicular transport is also presented. It is inferred that the cell junctions are the morphological equivalent of the small-pore system, and the vesicles the equivalent of the large-pore system. Peroxidase does not apparently cross brain capillaries: the endothelial cell junctions are regarded as zonulae occludentes, and vesicles do not appear to transport across the endothelium. This is regarded as the morphological equivalent of the blood-brain barrier for relatively large molecules. The tracers appear to permeate the fenestrae of fenestrated capillaries, and the high permeability of these capillaries to large molecules is attributed to the fenestrae. Capillaries with discontinuous endothelium readily allow passage of the tracers through the intercellular gaps. A continuous basement membrane may act as a relatively coarse filter for large molecules. In general, the morphology of capillaries correlates well with physiological observations. PMID- 19873631 TI - A single or dual channel in nerve membranes. PMID- 19873630 TI - Transcapillary exchange in relation to capillary circulation. AB - Transcapillary exchange of diffusible solutes depends on capillary blood flow, Q; capillary permeability, P; and capillary surface area, S. In a single capillary, the extent of equilibration of a given solute depends on the ratio of Q, to the product of P and S. In a microvascular bed consisting of many capillaries, equilibration depends on the fraction of them which are open to blood flow at any time and on the distribution of Q/PS ratios in the open capillaries. Both these characteristics are subject to control by vascular smooth muscle, particularly by the precapillary sphincters. Vasomotor mechanisms have been shown experimentally to exert a wide range of effective control over blood-tissue transport. In skeletal muscle, effective PS measured with (42)K or (86)Rb may be increased 8 fold from maximum nervous vasoconstriction to optimum metabolic vasodilatation. Most probably, these changes are due to differences in functional capillary surface area and of blood flow distribution relative to permeability and surface area. The extent to which variations in permeability itself can contribute to control of transcapillary exchange is not known. PMID- 19873632 TI - Single or dual channel mechanisms. PMID- 19873633 TI - Stimulation of the labellar sugar receptor of the fleshfly by mono- and disaccharides. AB - Responses of the labellar sugar receptor of the fleshfly, Boettcherisca peregrina, were studied over a wide range of concentrations of several sugars (sucrose, maltose, glucose, fructose, and mannose) in single solutions and in mixtures. The results suggest (a) that the receptor sites are not completely differentiated for glucose and for fructose combination, (b) that the receptor site is composed of two subunits. Such suggestions are based on the classical model, where the response is proportional to the number of the sites, two subunits of each site being simultaneously occupied with one molecule of disaccharides or two molecules of monosaccharides. It is shown, however, that an allosteric model gives a somewhat better interpretation of the experimental results. PMID- 19873634 TI - Thermal and spectral sensitivities of discrete slow potentials in limulus eye. AB - The discrete, subthreshold, slow potential fluctuations (SPF's) which can be recorded intracellularly in Limulus ommatidia are sensitive to temperature and light wavelength. SPF frequency increases with increasing temperature (Q(10) about 3.5) and light intensity. The effects are additive. SPF rise and decay time decrease with increasing temperature (Q(10) between 2 and 3). There is a peak, near 520 nm, in the spectral sensitivity of SPF frequency. This peak may correspond to the wavelength of maximum absorption by rhodopsin in the ommatidia. Hydroxylamine produces a rapid, irreversible reduction of SPF frequency and amplitude perhaps owing to its action on the photopigment. The cornea and crystalline cones fluoresce (peak about 445 nm) when excited by near-ultraviolet energy (380 nm peak) and this fluorescence may influence SPF spectral sensitivity measurements. These findings suggest that the SPF's are the results of photolytic and thermolytic reactions occurring in the ommatidial visual pigments and that they have a role in the mechanisms which transduce light to electrical activity in the visual receptors. PMID- 19873635 TI - Epithelial conduction in hydromedusae. AB - Sarsia, Euphysa, and other hydromedusae have been studied by electrophysiological techniques and are found to have nonnervous conducting epithelia resembling those described earlier for siphonophores. Simple, nonmuscular epithelia fire singly or repetitively following brief electrical stimuli. The pulses recorded with suction electrodes are biphasic, initially positive, and show amplitudes of 0.75-2.0 mv, durations of 5-15 msec, and velocities of 15-35 cm/sec with short refractory periods. In the swimming muscle (myoepithelium) 2.0-4.0 mv composite events lasting 150-300 msec are associated with contraction waves. Propagation in nonnervous epithelia is typically all-or-none, nondecremental, and unpolarized. The subumbrellar endoderm lamella conducts independently of the adjacent ectoderm. The lower regions of the tentacles do not show propagated epithelial events. The spread of excitation in conducting epithelia and associated effector responses are described. Examples are given of interaction between events seemingly conducted in the nervous system and those in nonnervous epithelia. Either system may excite the other. Spontaneous activity, however, appears to originate in the nervous system. Conduction in nonnervous tissues is unaffected by excess Mg(++) in concentrations suppressing presumed nervous activity, although this may not be a wholly adequate criterion for distinguishing components of the two systems. Evidence from old work by Romanes is considered in the light of these findings and the general significance of epithelial conduction is discussed. PMID- 19873636 TI - Calcium-binding properties of sarcoplasmic reticulum as influenced by ATP, caffeine, quinine, and local anesthetics. AB - Calcium retained at binding sites of the sarcoplasmic reticulum membranes isolated from rabbit skeletal muscle requires 10(-5) - 10(-4)M ATP to exchange with (45)Ca added to the medium. The ATP requirement for Ca exchangeability was observed with respect to the "intrinsic" Ca of the reticulum membranes and the fraction of Ca that is "actively" bound in the presence of ATP. Furthermore, a concentration of free Ca in the medium higher than 10(-8)M is required for ATP to promote Ca exchangeability. This exchangeability is not influenced by caffeine, quinine, procaine, and tetracaine, and Ca that is either nonexchangeable (in the absence of ATP) or exchangeable (in the presence of ATP) is released by 1-5 mM quinine or tetracaine, but neither caffeine (6 mM) nor procaine (2-5 mM) has this effect. Quinine or tetracaine also releases Ca and Mg bound passively to the reticulum membranes. A possible role of ATP in maintaining the integrity of cellular membranes is discussed, and the effects of caffeine, quinine, and of local anesthetics on the binding of Ca by the isolated reticulum are related to the effects of these agents on (45)Ca fluxes and on the twitch output observed in whole muscles. PMID- 19873637 TI - The electrical activity of embryonic chick heart cells isolated in tissue culture singly or in interconnected cell sheets. AB - Embryonic chick heart cells were cultured on a plastic surface in sparse sheets of 2-50 cells mutually in contact, or isolated as single cells. Conditions are described which permitted conjoint cells to be impaled with recording microelectrodes with 75% success, and isolated single cells with 8% success. It is proposed that cells in electrical contact with neighbors are protected from irreversible damage by the penetrating electrode, by a flow of ions or other substances from connected cells across low-impedance intercellular junctions. Action potentials recorded from conjoint and isolated single cells were similar in form and amplitude. The height or shape of the action potential thus appears not to depend upon spatial relationships of one cell to another. As the external potassium concentration was increased from 1.3 mM to 6 mM, cells became hyperpolarized while the afterhyperpolarization was reduced. At higher potassium levels, the afterhyperpolarization disappeared, the slope of the slow diastolic depolarization decreased, and resting potential fell along a linear curve with a slope of 61 mv per 10-fold increase in potassium. In pacemaker cells the diastolic depolarization consists of two phases: (a) recovery from the afterpotential of the previous action potential and (b) the pacemaker potential. These phases are separated by a point of inflection, and represent manifestations of different mechanisms. Evidence is presented that it is the point of inflection (PBA) rather than the point of maximal diastolic potential, that should be taken as the resting potential. PMID- 19873638 TI - The ionic basis of electrical activity in embryonic cardiac muscle. AB - The intracellular sodium concentration reported for young, embryonic chick hearts is extremely high and decreases progressively throughout the embryonic period, reaching a value of 43 mM immediately before hatching. This observation suggested that the ionic basis for excitation in embryonic chick heart may differ from that responsible for electrical activity of the adult organ. This hypothesis was tested by recording transmembrane resting and action potentials on hearts isolated from 6-day and 19-day chick embryos and varying the extracellular sodium and potassium concentrations. The results show that for both young and old embryonic cardiac cells the resting potential depends primarily on the extracellular potassium concentration and the amplitude and rate of rise of the action potential depend primarily on the extracellular sodium concentration. PMID- 19873639 TI - The Effects of Temperature upon Contraction and Ionic Exchange in Rabbit Ventricular Myocardium : Relation to control of active state. AB - The mechanical responses (active and resting tension, dP/dt, TPT) and ionic exchange characteristics (Ca(++), K(+), Na(+)) which follow upon a variation in temperature, rate, and [K(+)](o) were studied in the rabbit papillary muscle and arterially perfused rabbit interventricular setpum. Abrupt changes in temperature provided a means of separating the contributions of rate of development (intensity) of active state and duration of active state to total active tension development (approximated by isometric tension). Threefold changes in duration of active state with proportional changes in active tension can be induced without evidence for alteration of Ca(++), K(+), or Na(+) exchange. Abrupt cooling produced a moderate ( approximately 15%) increase of dP/dt which suggests an augmentation of active state intensity. Evidence is presented to suggest that this increase of dP/dt is based upon an increase in membrane Ca(++) concentration which occurs secondary to inhibition of active Na(+) transport. The alterations in ionic exchange and active state produced by variation of temperature are discussed in terms of a five-component control system. PMID- 19873640 TI - Binding proteins from animals with possible transport function. AB - Several proteins from various animal tissues with possible transport function have been briefly described, with emphasis given to a vitamin D-induced calcium binding protein (CaBP) implicated in calcium translocation across epithelial membranes. The latter protein was shown to be present in the small intestine, colon, kidney, and the uterus (shell gland) of the chicken. CaBP was also found in the small intestine of the rat, dog, bovine, and monkey. This protein has been isolated in high purity from chick intestinal mucosa and some of its properties determined. Its molecular weight is about 28,000, its formation constant, about 2.6 x 10(5) M(-1), and its binding capacity, 1 calcium atom per protein molecule. Correlative studies have shown that CaBP concentration in intestinal mucosa varies with the calcium absorptive capacity of the gut, thereby suggesting that CaBP is intimately involved in the process of calcium absorption. CaBP has been localized in the brush border region of the intestinal absorptive cell and within goblet cells. Among other proteins mentioned were the intrinsic factor required for vitamin B(12) absorption and the protein(s) associated with iron translocation. PMID- 19873641 TI - The transport of carbohydrates by a bacterial phosphotransferase system. AB - THE COMPONENTS AND PROPERTIES OF A PHOSPHOENOLPYRUVATE: glucose phosphotransferase system are reviewed, along with the evidence implicating this system in sugar transport across bacterial membranes. Some possible physiological implications of sugar transport mediated by the phosphotransferase system are also considered. PMID- 19873642 TI - Proteins of excitable membranes. AB - Excitable membranes have the special ability of changing rapidly and reversibly their permeability to ions, thereby controlling the ion movements that carry the electric currents propagating nerve impulses. Acetylcholine (ACh) is the specific signal which is released by excitation and is recognized by a specific protein, the ACh-receptor; it induces a conformational change, triggering off a sequence of reactions resulting in increased permeability. The hydrolysis of ACh by ACh esterase restores the barrier to ions. The enzymes hydrolyzing and forming ACh and the receptor protein are present in the various types of excitable membranes. Properties of the two proteins directly associated with electrical activity, receptor and esterase, will be described in this and subsequent lectures. ACh esterase has been shown to be located within the excitable membranes. Potent enzyme inhibitors block electrical activity demonstrating the essential role in this function. The enzyme has been recently crystallized and some protein properties will be described. The monocellular electroplax preparation offers a uniquely favorable material for analyzing the properties of the ACh-receptor and its relation to function. The essential role of the receptor in electrical activity has been demonstrated with specific receptor inhibitors. Recent data show the basically similar role of ACh in the axonal and junctional membranes; the differences of electrical events and pharmacological actions are due to variations of shape, structural organization, and environment. PMID- 19873643 TI - On Some Structural Analogies between Acetylcholinesterase and the Macromolecular Receptor of Acetylcholine. AB - Several properties of the enzyme acetylcholinesterase (AChE) isolated in vitro are compared with those of the membrane receptor(s) of acetylcholine expressed by the in vivo electrical response of the electroplax membrane. AChE strongly binds in vitro effectors of the electroplax: agonists e.g., decamethonium or antagonists, e.g., d-tubocurarine and flaxedil. It also reacts covalently with an affinity labeling reagent of the acetylcholine receptor site(s) in vivo (TDF). Two classes of sites on AChE molecule account for the binding of these quaternary nitrogen containing compounds: (1) the anionic site of the active center and (2) noncatalytic "peripheral anionic centers" located outside the active center. A disulfide bond breaking agent, dithiothreitol (DTT) alters in a parallel manner the reaction of AChE and the excitable membrane of the electroplax to TDF. The irreversibility of TDF action is lost in both cases, after exposure to DTT. Both AChE and the acetylcholine receptor thus contain disulfide bonds-they are closely related but not necessarily identical proteins. PMID- 19873644 TI - Chemical modification of the active site of the acetylcholine receptor. AB - The receptor for acetylcholine in the subsynaptic membrane of the electroplax of Electrophorus electricus is a protein with a disulfide bond in the vicinity of the active site. This disulfide can be reduced and reoxidized with concomitant inhibition and restoration of the response to acetylcholine and other monoquaternary ammonium-depolarizing agents. Conversely, the bisquaternary hexamethonium, normally a competitive inhibitor, causes depolarization, and the activity of decamethonium is increased following reduction of the disulfide. The reduced receptor can be alkylated by various maleimide derivatives and is then no longer reoxidizable. Some quaternary ammonium maleimide derivatives act as affinity labels of the reduced receptor, alkylating it at a rate three orders of magnitude faster then do uncharged maleimide derivatives. Other types of potential affinity labels also react only with the reduced receptor and the resulting covalently attached quaternary ammonium moieties interact with the active site, strongly activating the receptor. These results suggest a model for the active site and its transitions in which an activator such as acetylcholine bridges between a negative subsite and a hydrophobic subsite in the vicinity of the disulfide, causing an altered conformation around the negative subsite and a decrasee of a few angstroms in the distance between the two subsites. PMID- 19873645 TI - Action on the electroplax of antibiotics affecting membrane permeability. PMID- 19873646 TI - Dissociation and reassociation of bacterial membrane components. AB - The dissociation of the phospholipid, lipopolysaccharide, and protein components of the bacterial cell envelope results in loss of enzyme activities which are normally located in the cell envelope structure and which are involved in lipopolysaccharide biosynthesis. The activity of one of these enzymes, UDP galactose:lipopolysaccharide alpha,3 galactosyl transferase, can be restored by the reassociation of purified phospholipid, lipopolysaccharide, and enzyme protein. Reconstitution of activity occurs in stepwise fashion: lipopolysaccharide + phospholipid --> lipopolysaccharide.phospholipid See PDF for Equation enzyme.lipopolysaccharide.phospholipid. The intermediates in the reaction were isolated by gradient centrifugation. The final ternary complex behaves in a similar manner to the intact cell envelope in the enzyme reaction and appears to represent the reconstitution of a portion of the membranous portion of the cell envelope. PMID- 19873647 TI - Isologous oxygen, sulfur, and selenium compounds as probes of acetylcholine receptors. AB - Evidence is presented that while the conformations of acetylcholine and acetylthiolcholine are different, acetylthiolcholine and acetylselenolcholine are structurally and conformationally very similar. Experiments with sulfur and selenium isologs of acetylcholine, choline, and local anesthetics suggest that the active sites of receptors of the electroplax and of electric eel acetylcholinesterase are different, but are compatible with the postulate that acetylcholine receptors of axonal and synaptic excitable membranes are similar. PMID- 19873648 TI - Spin-labeled membranes. PMID- 19873649 TI - Affinities or apparent affinities of the transport adenosine triphosphatase system. AB - The interactions of potassium ions and ATP on transport ATPase activity are discussed, and the interpretation of these interactions is shown to be often ambiguous. Caldwell's (1968) Physiological Review model is discussed with particular reference to the observed kinetics of sodium: sodium exchange in red cells. Recent experimental work on the properties of the ouabain-sensitive component of potassium efflux from red cells is described. This component of efflux occurs only if either sodium or potassium are present in the external medium, but the effects of external sodium and potassium are not additive. The relation between ouabain-sensitive potassium efflux and the external concentration of sodium (in a potassium-free medium) or of potassium (in low- and high-sodium media) are described. When starved sodium-poor red cells are poisoned with iodoacetamide, loaded with phosphate, and incubated in high-sodium potassium free media, the ouabain-sensitive efflux of potassium appears to be accompanied by the reversal of the entire ATPase system. About two to three potassium ions leave by the ouabain-sensitive route for each molecule of ATP synthesized. If potassium is present in the external medium, no ouabain-sensitive synthesis of ATP occurs and the ouabain-sensitive efflux of potassium presumably involves the reversal of only the last part of the ATPase system. PMID- 19873650 TI - Membrane lipids and the conformations of membrane proteins. AB - The general relations between protein conformation and the optical activity of peptide chromophores are outlined and applied to the analysis of the optical rotatory dispersion and circular dichroism of the plasma membranes of human erythrocytes and Ehrlich ascites carcinoma cells. It is concluded that the proteins of these membranes are "globular" and that they have considerable helical content. The spectroscopic consequences of perturbing the membranes with phospholipase C, phospholipase A, lysolecithin, and sodium dodecyl sulfate are examined in the light of the effects of these agents upon certain enzymatic and physical properties of the membranes and upon their proton magnetic resonance spectra. The data suggest that the architecture of membrane proteins is strongly dependent upon apolar lipid-protein and/or lipid-sensitive protein-protein interactions. PMID- 19873651 TI - Flexibility of an active center in sodium-plus-potassium adenosine triphosphatase. AB - In plasma membranes of intact cells an enzymatic pump actively transports sodium ions inward and potassium ions outward. In preparations of broken membranes it appears as an adenosine triphosphatase dependent on magnesium, sodium, and potassium ions together. In this adenosine triphosphatase a phosphorylated intermediate is formed from adenosine triphosphate in the presence of sodium ions and is hydrolyzed with the addition of potassium ions. The normal intermediate was not split by adenosine diphosphate. However, selective poisoning by N ethylmaleimide or partial inhibition by a low magnesium ion concentration yielded an intermediate split by adenosine diphosphate and insensitive to potassium ions. Pulse experiments on the native enzyme supported further a hypothesis of a sequence of phosphorylated forms, the first being made reversibly from adenosine triphosphate in the presence of sodium ion and the second being made irreversiblyfrom the first and hydrolyzed in the presence of potassium ion. The cardioactive steriod inhibitor, ouabain, appeared to combine preferentially with the second form. Phosphorylation was at the same active site according to electrophoretic patterns of proteolytic phosphorylated fragments of both reactive forms. It is concluded that there is a conformational change in the active center for phosphorylation during the normal reaction sequence. This change may be linked to one required theoretically for active translocation of ions across the cell membrane. PMID- 19873652 TI - On the molecular characterization of the sodium-potassium transport adenosine triphosphatase. AB - The phosphorylated intermediate in the (Na + K)-activated adenosine triphosphatase (Na-K ATPase) has been characterized as an L-glutamyl-gamma phosphate residue in the enzyme. This has been accomplished by digestion of the phosphorylated and nonphosphorylated forms of the enzyme with pepsin, reaction of the pepsin digests with [2,3-(3)H]N-(n-propyl)hydroxylmine, further digestion of the derivatized peptides with pronase in the presence of carrier L-glutamyl-gamma N-(n-propyl)hydroxamate and carrier L-aspartyl-N-(n-propyl)hydroxamate, and chromatographic purification. An increment in radioactivity migrated with authentic L-glutamyl-gamma-N-(n-propyl)hydroxamate in a total of seven electrophoretic and chromatographic systems and on gel filtration. No increment in radioactivity was associated with authentic L-aspartyl-beta-N-(n propyl)hydroxamate in five out of the seven chromatographic and electrophoretic systems. At the last stage of purification the radioactivity from the phosphorylated enzyme which migrated as L-glutamyl-gamma-N-(n-propyl)hydroxamate was 2(1/2) times that from the nonphosphorylated enzyme. On the basis of these results it is concluded that the phosphorylated intermediate in the Na-K ATPase is an L-glutamyl-gamma-phosphate residue. The beef brain Na-K ATPase has been solubilized with the nonionic detergent, Lubrol, and has been purified 10 times over that in the original microsomes. The soluble enzyme remains stable in the presence of ATP and either Na(+) or K(+). If the partially purified enzyme is electrophoresed in 3% polyacrylamide, followed by incubation with ATP, Na(+), K(+), and Mg(++), a single, somewhat diffuse, ATPase band, which is ouabain sensitive is seen. Protein impurities are also seen on the gel. Gel electrophoresis, after treatment of the partially purified enzyme with phenol acetic acid-urea, shows about 12 discrete protein bands. Studies on the site directed alkylation of the (Na + K)-activated adenosine triphosphatase with haloacetate derivatives of cardiotonic steroids are reviewed. Efforts are now underway to specifically alkylate the cardiotonic steroid site of the Na-K ATPase with hellebrigenin 3-[2-(3)H]iodoacetate and to purify the subunit of the enzyme containing the cardiotonic steroid site by following radioactivity. Finally, a working model for the role of the Na-K ATPase in the coupled transport of Na and K is presented. PMID- 19873653 TI - The Interaction between Tritiated Ouabain and the Na-K Pump in Red Blood Cells. PMID- 19873654 TI - Resolution and reconstitution of a Mammalian membrane. AB - The problem of the resolution and reconstitution of the inner mitochondrial membrane has been approached at three levels. (1) Starting with phosphorylating submitochondrial particles, a "resolution from without" can be achieved by stripping of surface components. The most extensive resolution was recently obtained with the aid of silicotungstate. Such particles require for oxidative phosphorylation the addition of several coupling factors as well as succinate dehydrogenase. (2) Starting with submitochondrial particles that have been degraded by trypsin and urea a resolution of the inner membrane proper containing an ATPase has been achieved. These experiments show that at least five components are required for the reconstitution of an oligomycin-sensitive ATPase: a particulate component, F(1), Mg(++), phospholipids, and F(c). Morphologically, the reconstituted ATPase preparations resemble submitochondrial particles. (3) Starting with intact mitochondria individual components of the oxidation chain have been separated from each other. The following components were required for the reconstitution of succinoxidase: succinate dehydrogenase, cytochrome b?, cytochrome c(1), cytochrome c, cytochrome oxidase, phospholipids and Q(10). The reconstituted complex had properties similar to those of phosphorylating submitochondrial particles; i.e., the oxidation of succinate by molecular oxygen was highly sensitive to antimycin. PMID- 19873655 TI - Microenvironmental effects on enzyme activity. PMID- 19873656 TI - Identification of Mitochondrial Inner Membranes in Anaerobically Grown Baker's Yeast. PMID- 19873657 TI - Studies on a protein component of Guinea pig erythrocyte membranes. PMID- 19873658 TI - Intra-protein interactions across a fluid membrane as a model for biological transport. AB - A model is proposed for the mechanism of action of the glucose transport system of the human erythrocyte. The model is based on the possibility of there being interaction through the membrane between superficially disposed protein subunits, these units being embedded within the bimolecular lipid layer, anchored to the aqueous phase, perhaps mobile in the plane of each face of the membrane. The subunits have the ability to bind sugar and, when associated with the symmetrical protein at the opposite face of the membrane, transfer sugar across the membrane. Evidence for the model is presented. The possibility that this model may also be a model for the cell membrane as such is briefly touched upon. PMID- 19873659 TI - Studies on the Lactose Transport System in Escherichia coli. PMID- 19873660 TI - The effect of osmotic shock on release of bacterial proteins and on active transport. AB - Osmotic shock is a procedure in which Gram-negative bacteria are treated as follows. First they are suspended in 0.5 M sucrose containing ethylenediaminetetraacetate. After removal of the sucrose by centrifugation, the pellet of cells is rapidly dispersed in cold, very dilute, MgCl(2). This causes the selective release of a group of hydrolytic enzymes. In addition, there is selective release of certain binding proteins. So far, binding proteins for D galactose, L-leucine, and inorganic sulfate have been discovered and purified. The binding proteins form a reversible complex with the substrate but catalyze no chemical change, and no enzymatic activities have been detected. Various lines of evidence suggest that the binding proteins may play a role in active transport: (a) osmotic shock causes a large drop in transport activity associated with the release of binding protein; (b) transport-negative mutants have been found which lack the corresponding binding protein; (c) the affinity constants for binding and transport are similar; and (d) repression of active transport of leucine was accompanied by loss of binding protein. The binding proteins and hydrolytic enzymes released by shock appear to be located in the cell envelope. Glucose 6 phosphate acts as an inducer for its own transport system when supplied exogenously, but not when generated endogenously from glucose. PMID- 19873661 TI - Interferons: purification and physicochemical aspects. AB - Antiviral interferon activity in any one species can be exhibited by a variety of substances that differ in their physical and chemical properties, but the nature of these differences is not understood. Conditions that can lead to the formation of diverse types of interferons have been outlined. Reasons have been adduced why, for certain purposes, purification of interferons is desirable or even necessary, and examples have been presented to show how and to what extent this has been achieved. In spite of some very high purification factors, not a single interferon has been obtained as a pure substance. Therefore, all available knowledge of physical and chemical properties has been obtained by indirect means. PMID- 19873662 TI - Molecular aspects of interferon induction by viruses. AB - Virus-induced interferon formation depends on the presence within the cell of a viral ribonucleic acid. This RNA may either be double stranded or, in certain cases, single stranded. The double-stranded RNA can be derived from a virus, such as reovirus, which contains this type of RNA, or it may be synthesized within the cell using viral single-stranded RNA as a template. Single-stranded RNA must possess a stable configuration in solution to be active, and certain viral RNA molecules appear to be active for this reason. The presence of this RNA triggers a derepression event, which is probably nuclear, by an unknown mechanism, and this is followed by the production of an interferon messenger RNA and its translation. Little is known of the derepression event or the events that follow it. PMID- 19873663 TI - Comparison of in vitro and in vivo labeling of virus-induced L-cell interferon. AB - Preparations of NDV(uv)-induced L-cell interferon were labeled in vitro with (125)I and (3)H gas, or in vivo through incorporation of amino acids-(3)H during synthesis. Prior to purification, more than 90% of the interferon titer was lost during in vitro labeling by either procedure, whereas 34% of the initial activity of in vivo-labeled material was preserved during preparatory handling. Purification by carboxymethyl-Sephadex chromatography and electrophoresis in polyacrylamide gels was about 100-fold, and electrophoretic profiles revealed close concordance between isotopes and interferon titers in all instances. Noninterferon proteins from control cells, although less extensively labeled with tritium during synthesis than proteins from interferon-producing cells and released in lesser amounts, also contained components of identical electrophoretic mobility and distribution in acrylamide gels as interferon. The highest specific activity (6 x 10(6) U/mg protein) but lowest cpm per interferon unit ratio (0.3) were exhibited by in vivo-labeled interferon. The advantage of better isotope incorporation through in vitro labeling techniques was largely offset by extensive losses in interferon activity. PMID- 19873664 TI - Studies on the mechanism of interferon action. AB - Interferon does not inactivate viruses or viral RNA. Virus growth is inhibited in interferon-treated cells, but apart from conferring resistance to virus growth, no other effect of interferon on cells has been definitely shown to take place. Interferon binds to cells even in the cold, but a period of incubation at 37 degrees C is required for development of antiviral activity. Cytoplasmic uptake of interferon has not been unequivocally demonstrated. Studies with antimetabolites indicate that the antiviral action of interferon requires host RNA and protein synthesis. Experiments with 2-mercapto-1(beta-4-pyridethyl) benzimidazole (MPB) suggest that an additional step is required between the binding and the synthesis of macromolecules. Interferon does not affect the adsorption, penetration, or uncoating of RNA or DNA viruses, but viral RNA synthesis is inhibited in cells infected with RNA viruses. The main action of interferon appears to be the inhibition of the translation of virus genetic information probably by inhibiting the initiation of virus protein synthesis. PMID- 19873665 TI - Development of the antiviral state in response to interferon. AB - The development of resistance in response to interferon depends on cellular RNA synthesis and probably also on cellular protein synthesis. The evidence for these requirements is reviewed, as well as the proposal that this evidence indicates the existence of a specific response of the cell to interferon, involving the induced synthesis of an antiviral protein. Direct evidence for such an interpretation has not been obtained, and alternative explanations are discussed which do not require quantitative or qualitative differences in the RNA and protein made in cells exposed to interferon. The possible role of the ribosome in the antiviral action of interferon is also discussed. PMID- 19873666 TI - [Not Available]. PMID- 19873667 TI - The defensive role of the interferon system. AB - The evidence relating the interferon system to the infectious process has been examined. The available evidence supports the view that the interferon system is an important component of the body's nonimmune defenses, which are probably the major causes of recovery from already established virus infections of body tissues. The interferon system can also serve to limit virus spread through the bloodstream. Factors which may influence the interferon system and thereby influence virus infection have been considered. Finally, evidence is presented which indicates that the interferon system is one of the determinants of virulence of certain viruses and is one of the determinants of some persistent virus infections. PMID- 19873668 TI - Interrelationships of interferon and immunity during viral infections. AB - Interferon is one determinant of host resistance. The immune responses, cellular or humoral, are other components. Cell-mediated responses appear to be involved in host resistance to certain viral infections, particularly the herpesvirus group and vaccinia virus. It is suggested that immune and interferon responses may complement one another and contribute to host resistance. The relative importance of each component depends upon the virus-host interaction. Finally, evidence has been presented which suggests that production of interferon as a result of antigen-sensitized cell interaction may further link these two components of the host response. PMID- 19873669 TI - Interferon and interferon inducers in protozoal infections. AB - Several interferon inducers (Newcastle disease virus, statolon, and poly rI:poly rC) as well as exogenous mouse interferon protect mice from sporozoite-induced Plasmodium berghei malaria, as long as they are administered before the end of the preerythrocytic phase of development of the parasite. The protective effect of the interferon inducers was related to their interferon-inducing effect; the protective effect of the interferon preparations was related to the interferon titer of the preparations, and it exhibited other attributes of interferon such as species specificity. In contrast to sporozoite-induced infection, blood forms induced P. berghei malaria was only weakly susceptible to the protective effect of interferon inducers. This difference may provide an approach to study the mechanism of protection. The growth in cell cultures of another intracellular protozoon, Toxoplasma gondii, is also inhibited by interferon (22). The fact that P. berghei and T. gondii (as well as another group of intracellular parasites susceptible to interferon, the Chlamydia) have their own ribosomes raises questions, concerning the role of host cell ribosomes in the host cell-parasite relationship of these intracellular parasites and in the mechanism of interferon action against them, that can be approached experimentally. The possibility of therapeutic or prophylactic application of interferon or of its inducers to certain protozoal diseases of man and of other animals is still remote, but it has to be considered for long range planning. PMID- 19873670 TI - Interferon and interferon inducers in the treatment of malignancies. AB - The mechanism of the antitumor action of polyinosinic-polycytidylic acid is probably multifaceted. The compound induces the synthesis of interferon, and interferon probably is active against some tumors. Poly I:poly C alters protein and RNA synthesis in tissue culture. It specifically inhibits such macromolecule synthesis in tumors in vivo, while having less inhibitory action on synthesis in normal organs, or it may actually enhance. Finally, poly I:poly C strongly enhances graft vs. host rejection mechanisms, which may play a role in the rejection of some tumors. PMID- 19873671 TI - Interferon and ocular viral disease. PMID- 19873672 TI - Interferon production by nonviral stimuli of microbial origin. AB - An increasing number of nonviral materials of microbial origin has been reported to stimulate the production of interferon in cell cultures and (or) in animals. These materials include (a) gram-negative bacteria or the endotoxins prepared from their cell walls, (b) other microorganisms such as Rickettsiae, Bedsoniae, Protozoa, and (c) fungal products such as a mannan from Candida and various antibiotics which act as protein synthesis inhibitors, e.g., glutarimide antibiotics and tenuazonic acid. A summary is presented of the current state of knowledge about interferon production in animals by the most thoroughly studied nonviral substance of microbial origin, bacterial endotoxin. Further evidence is presented which clearly distinguishes the "endotoxin-type" of interferon response in animals from the response seen after the injection of virus. The data suggest that the release of preformed interferon from the tissues occurs in animals injected with endotoxin. On the other hand, interferon produced in response to the injection of virus is newly synthesized protein. While the exact chemical structure of the component of bacterial endotoxin responsible for interferon release has not yet been elucidated, it is clear that the lipid portion of the lipopolysaccharide, rather than the O-specific polysaccharide side chains or the core polysaccharide, is the active moiety. PMID- 19873673 TI - Interferon induction by viruses. AB - Interferons are proteins of cellular origin capable of conferring virus resistance to vertebrate cells. Most cells do not produce interferons except in response to proper stimulation. Clearly, the stimulation of interferon production encompasses two phenomena. When stimulated, some cell systems produce their interferons by synthesizing new proteins. Other cell systems do not require the synthesis of new proteins to produce interferons, and still other cell systems may produce interferons by both means. Before much can be learned from the detailed study of the nature of the molecules which stimulate interferons, the type of phenomenon which the stimulus induces must be identified. Chick embryo tissues apparently make interferons by synthesizing new proteins. Many viruses stimulate interferon production in chick embryo tissues. Data available suggest that neither the protein nor nucleic acid moieties of the added virions act as inducing molecules. Also, double-stranded replicative form is probably not responsible. It is suggested that the inducer molecule may be cellular in nature and may be produced in response to a wide variety of insults among which are viral infections. PMID- 19873674 TI - Circulating Interferon Production in the Mouse : Origin and nature of cells involved and influence of animal genotype. AB - A radiobiological study of circulating interferon production in the mouse was undertaken in the hope of elucidating the site(s) of circulating interferon production. After total body X-irradiation of the animals, different radiosensitivities of circulating interferon production were observed with different viral inducers. Myxovirus-induced circulating interferon production was especially radiosensitive. Moreover, a study of interferon production in syngeneic and xenogeneic radiochimeras demonstrated that cells producing NDV (Newcastle disease virus)-induced circulating interferon were derived from hematopoietic stem cells. In addition, treatment of mice with antilymphocyte serum significantly reduced NDV- and Sendai virus-induced circulating interferon, as opposed to other inducers. Taken together, these results strongly suggest that the lymphocyte is the major source of myxovirus-induced circulating interferon. A survey of interferon production in 12 inbred mouse strains, using NDV as inducer, revealed the existence of low and high producers. A Mendelian analysis carried out with low producing Balb/c and high producing C57BL indicated that the difference between low and high interferon producers was caused by a single, autosomal, codominant factor. PMID- 19873675 TI - Nonviral interferon inducers. AB - Interferon production can be stimulated by a great variety of microbial and nonmicrobial agents other than viruses. The nonmicrobial inducers can be divided into polyanions, mitogens, and a miscellaneous category including the various endotoxins and antibiotics. The polyanions appear to require a stable, high molecular weight backbone and a high density of free anionic groups whether they are polynucleotides, plastics, or polysaccharides. Mitogen-induced interferon appears to be but one of a constellation of substances produced following lymphocyte transformation. The process of transformation can be stimulated either by specific immune recognition or non-specifically by phytohemagglutinin. Synthetic polynucleotide inducers are active; the thermostable, double-stranded RNA's are much more active than the double-stranded DNA's or 1-, 3-, or 4 stranded RNA's. Some success has been obtained with potentiation of nucleotide inducers through the use of polycationic substances, complexing with a polysaccharide, concurrent administration of a metabolic antagonist, or substitution of phosphate by thiophosphate in the polynucleotide backbone. The stages in the interaction of interferon stimulating RNA and cells can be divided into three steps: first, binding to cell surface, next, a temperature dependent "recognition" step, and finally, degradation and utilization of monomers in cellular RNA synthesis; the critical recognition site has not yet been determined. The vast majority of cell-associated polynucleotide remains at the surface of the cell. Information from animal models resembling human diseases suggests that certain of these nucleotide inducers may have clinical usefulness in therapy or prophylaxis. PMID- 19873676 TI - Cellular mechanisms of interferon production. AB - Rabbit kidney cell cultures stimulated with either double-stranded polyinosinate polycytidylate (poly I:poly C) or with ultraviolet-irradiated Newcastle disease virus (UV-NDV) produce two types of interferon response, designated "early" and "late," respectively. The early response is suppressed by inhibitors of RNA or protein synthesis and is therefore thought to represent de novo synthesis of interferon. Circumstantial evidence suggested that this interferon response is regulated by a translation control mechanism. Late interferon production with poly I:poly C only took place in the presence of inhibitors of RNA or protein synthesis. The late interferon is therefore likely to be derived by the activation of an interferon precursor. The stimulation of late poly I:poly C induced interferon production by cycloheximide suggested the existence of a second, posttranslational level of control of interferon production. This posttranslation control seems to be activated by interferon. UV-NDV can probably suppress the synthesis of the posttranslation inhibitory protein, and therefore it stimulates a late interferon response in the absence of inhibitors of RNA or protein synthesis. It is postulated that both the translation and posttranslation inhibitor participate in the development of a cellular refractory state to repeated interferon stimulation. The picture of interferon which emerges from this study is one of a heterogenous class of proteins whose production is controlled by cellular repressors acting at various levels. PMID- 19873677 TI - Double-stranded polynucleotides as interferon inducers. AB - A discussion of factors considered influential in making a polynucleotide an efficient inducer of interferon was presented. These factors were double strandedness of the polynucleotides, the sugar moiety of the polynucleotides, thermal stability, resistance to enzymatic degradation, and molecular size of the polynucloetides. Recent developments concerning interferon induction during virus infection were also discussed. PMID- 19873678 TI - Control of interferon production in rabbit cells treated with poly I:C. PMID- 19873679 TI - The uptake of a labeled double-stranded polynucleotide by cultured rabbit kidney cells: an electron microscopic study. AB - Polyribocytidylate-(3)H-polyriboinosinate (rC-(3)H:rI) enters cultured rabbit kidney cells from the surrounding medium within (1/2) hr after exposure. Grains are found in the cytoplasm, nucleus, and nucleolus. At 2 hr, grains are localized predominantly over the nucleolar regions. Subsequently, the grains in the nucleus become dispersed. A specific receptor site for the initiation of interferon production was not revealed. PMID- 19873680 TI - Functional Organization of the Cardiac Ganglion of the Lobster, Homarus americanus. AB - External recording and stimulation, techniques were used to determine which neurons and interactions are essential for production of the periodic burst discharge in the lobster cardiac ganglion. Burst activity can be modulated by brief single shocks applied to the four small cells, but not by similar stimulation of the five large cells, suggesting that normally one or more small cells primarily determine burst rate and duration. Repetitive electrical stimulation of large cells initiates spike activity in small cells, probably via excitatory synaptic and/or electrotonic connections which may normally act to prolong bursts and decrease burst rate. Transection of the ganglion can result in burst activity in small cells in the partial or complete absence of large cell spike activity, but large cells isolated from small cell excitatory synaptic input by transection or by application of dinitrophenol do not burst. Generally, transections which decrease excitatory feedback to small cells are accompanied by an increase in burst rate, but mean spike frequency over an entire burst cycle stabilizes at the original level within 10-30 min for various groups of cells whose spike-initiating sites are still intact. These and previous results suggest that the system is two layered: one or more small cells generate the burst pattern and impose it on the large cells which are the system's motorneurons. PMID- 19873681 TI - A Relaxation Oscillator Description of the Burst-Generating Mechanism in the Cardiac Ganglion of the Lobster, Homarus americanus. AB - Properties of the neural mechanism responsible for generating the periodic burst of spike potentials in the nine ganglion neurons were investigated by applying brief, single shocks to the four small cells with extracellular electrodes placed near the trigger zones of the small cells. The shock elicited a burst if presented during the latter portion of the silent period, terminated a burst during the latter portion of the burst period, and was followed by a newly initiated burst during the early portion of the burst period. The resultant changes in burst and silent period durations were quantitatively described by a second-order non-linear differential equation similar to the van der Pol equation for a relaxation oscillator. The equation also qualitatively described changes in firing threshold of the small cells during the burst cycle. The first derivative of the solution to the equation is similar to slow transmembrane potentials in neurons that are involved in generation of burst activity in other crustacean cardiac ganglia. PMID- 19873682 TI - Stark realities. Interview by Elizabeth Gardner. PMID- 19873683 TI - Wire mesh flooring--boon or bedevilment? A precedent for future use? PMID- 19873685 TI - Canadian Institutes of Health Research-Institute of Aging: profiles. Bridging policy and research on aging in Canada: recognizing an anniversary, realizing an opportunity. PMID- 19873684 TI - Leptin gene -2548G/A variants predict risperidone-associated weight gain in children and adolescents. AB - OBJECTIVE: As the use of atypical antipsychotics in children and adolescents has increased, concerns have been raised about their long-term safety. We aimed to investigate the association between risperidone-induced weight gain, leptin concentration, and the leptin gene (LEP) -2548G/A variants in youths. METHODS: Medically healthy 7- to 17-year-old children and adolescents, in extended naturalistic treatment with risperidone, were recruited through pediatric psychiatry clinics. Anthropometric measures and laboratory testing were conducted. Growth and medication history was obtained from the medical record. The effect of the LEP genotypes on leptin concentration and on the slopes of the weight and body mass index (BMI) Z-score curves before and after the onset of risperidone treatment was investigated . RESULTS: In 74 individuals, chronically treated with risperidone, the A allele was associated with higher leptin concentration at low weight and BMI Z-scores. There was no effect of the LEP genotypes on weight or BMI Z-scores before risperidone was started. Afterwards, however, the A-allele carriers showed a steeper rate of increase in weight and BMI Z-scores. As a result, the GG-genotype carriers were 2.5 times less likely to be overweight/obese (i.e. having a BMI above the 85th percentile). This genetic effect on risperidone-associated weight gain did not extend to weight loss related to psychostimulants. CONCLUSION: The LEP - 2548G/A variants seem to moderate the weight-altering effect of risperidone but not psychostimulants. This may be related to genetic differences in tissue sensitivity to leptin, resulting in differential body composition. PMID- 19873686 TI - Depression symptoms and health-related quality of life among patients with metastatic breast cancer in programme of palliative cancer care. AB - Depression is seen in many cancer patients. It occurs in approximately 25% of palliative care patients. The quality of life term contains the information on an individual's physical social and spiritual condition. The study evaluated incidence and relevance of depression symptoms and level of health-related quality of life (HRQoL) among patients with metastatic breast cancer in programme of palliative cancer care. This study was local prospective and cross-sectional. It was carried at Department of Clinical Oncology and Radiation Therapy of Charles University Hospital in Hrader Kralove, Czech Republic. Dates were obtained during year 2008 among 41 patients with metastatic breast cancer in programme of palliative cancer care. The mean age for all 41 subjects was 58 years old (aged 41 - 80 years old). The Czech version of Zung self-rating depression scale was performed for evaluation of depression symptoms. The Czech version of genetic EuroQol questionnaire EQ-5D was performed for evaluation of level of HRQoL. The statistical evaluation presents that mean ZSDS (Zung self rating depression score) certifies the presence of signs of moderately depression symptoms among patients with metastatic breast cancer (ZSDS range was 60-69). The mean ZSDS in all patients was 60,6. The mean ZSDS is group of healthy females was 38,9 (normal range of ZSDS). The incidence of depression was 61% (25 of all 41 subjects). The relevance of depression is characterized: severely depressed was proved in 5 of all 25 subjects, the moderately depressed in 10 subjects of all 25 subjects and mildly depressed in 10 of all 25 subjects. The statistical evaluation not presents statistically significant dependence of ZSDS on age, number of associated diseases and type of palliative cancer care. The HRQoL among patients with metastatic breast cancer is on very low level. The mean EQ-5D score (dimension of quality of life) was 55%. The mean EQ-5D VAS (subjective health condition) was 59,2%. The mean EQ-5D score in group of healthy female was 78,4% and the mean EQ-5D VAS was 85% (both QoL parameters show very good of QoL level). The statistical evaluation not presents statistically significant dependence of EQ-5D score and EQ-5D VAS on age, number of associated diseases and type of palliative cancer care. The results showed that subsist clear association between metastatic breast cancer in programme of palliative cancer care and depression. Also, the results showed that subsist low level of HRQoL of patients with metastatic breast cancer. PMID- 19873687 TI - Therapeutic monitoring of vancomycin in adults summary of consensus recommendations from the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists. AB - Vancomycin is a commonly used antibiotic due to its effectiveness in treating serious gram-positive infections caused by methicillin-resistant Staphylococcus aureus. As commercial drug assays and a multitude of pharmacokinetic data from a variety of patient populations are widely available, therapeutic monitoring of serum vancomycin concentrations is frequently performed by clinicians, with the expectation that targeting the concentrations within a relatively narrow range can minimize toxicity yet still achieve therapeutic success. Much debate exists, however, over the value of routine therapeutic monitoring of vancomycin levels because of conflicting evidence regarding the ability of serum concentrations to predict effectiveness or prevent toxicity. In addition, studies have suggested that the potential for nephrotoxicity or ototoxicity with vancomycin monotherapy is minimal at conventional dosages of 1 g (15 mg/kg) every 12 hours. However, increased rates of nephrotoxicity have recently been reported with doses of 4 g/day or higher. The American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists published a consensus statement on therapeutic monitoring of serum vancomycin levels in adults. These organizations established an expert panel to review the scientific data and controversies associated with vancomycin monitoring and to make recommendations based on the available evidence. As the members of this panel, we summarize the conclusions and highlight the recommendations from the consensus statement. We determined that the area under the concentration-time curve (AUC): minimum inhibitory concentration (MIC) ratio is the most useful pharmacodynamic parameter to predict vancomycin effectiveness and suggested a target ratio of 400 or greater to eradicate S. aureus. In addition, trough serum concentration monitoring is the most accurate and practical method to monitor vancomycin serum levels. Increasing trough concentrations to 15-20 mg/L to attain the target AUC:MIC ratio may be desirable but is currently not supported by clinical trials. Alternative therapies should be considered in patients with S. aureus infections that demonstrate a vancomycin MIC of 2 mg/L or greater because the target AUC:MIC ratio ( 400) is unlikely to be achieved in this setting. Increasing the dosage to result in higher trough concentrations may increase the potential for toxicity; however additional clinical experience is required to determine the extent. PMID- 19873689 TI - What you need to know about the H1N1 vaccine. PMID- 19873688 TI - A simulation of the comparative long-term effectiveness of liraglutide and glimepiride monotherapies in patients with type 2 diabetes mellitus. AB - STUDY OBJECTIVE: To project and compare long-term outcomes of morbidity and mortality, and costs of complications of type 2 diabetes mellitus from a randomized controlled trial of patients receiving liraglutide versus glimepiride monotherapy. DESIGN: Mathematic simulation using the validated Center for Outcomes Research (CORE) Diabetes Model, calibrated to baseline patient characteristics from a short-term, randomized, controlled trial of liraglutide and glimepiride monotherapies (Liraglutide Effect and Action in Diabetes [LEAD]-3 trial) and using data from long-term outcomes studies. SETTING: Simulated routine clinical practice. PATIENTS: Seven hundred forty-six patients with type 2 diabetes who participated in the LEAD-3 trial, and three hypothetical cohorts of 5000 patients each that were based on the baseline characteristics of the patients in the LEAD-3 trial. The patients in the LEAD-3 trial were randomly assigned to monotherapy with liraglutide 1.2 mg/day (251 patients), liraglutide 1.8 mg/day (247 patients), or glimepiride 8 mg/day (248 patients). MEASUREMENTS AND MAIN RESULTS: The impact of the three treatments for type 2 diabetes on survival and cumulative incidence of cardiovascular, ocular, or renal events and costs were estimated at three time periods: 10, 20, and 30 years. Simulations predicted improved survival for liraglutide 1.8 and 1.2 mg at all three time points compared with glimepiride. Survival benefits were greatest after 30 years of follow-up: 16.5%, 13.6%, and 7.3%, respectively. The frequency of nonfatal renal and ocular events was lower for both liraglutide doses than for glimepiride. The rate of neuropathies leading to first or recurrent amputation was higher for glimepiride compared with both liraglutide doses. The average cumulative cost/patient was higher for glimepiride compared with liraglutide 1.2 mg and liraglutide 1.8 mg. CONCLUSION: With use of the CORE Diabetes Model and data from the LEAD-3 trial, long-term projected survival, diabetes complications, and costs favored liraglutide 1.2- and 1.8-mg monotherapies compared with glimepiride in the treatment of type 2 diabetes. PMID- 19873690 TI - Cutaneous manifestations of systemic tropical parasitic diseases. AB - Tropical diseases continue to cause significant health problems in developing nations. An overview of illnesses with notable cutaneous findings caused by protozoans and helminthes is provided. The role of the health care provider in disease management is described. PMID- 19873691 TI - Current biologic treatments for psoriasis. AB - Psoriasis is a common inflammatory disorder. Modes of treatment include topical, UVA/UVB, systemic, and recently, biologic treatments. As the development ofbiologics continues, biologics have a marked effect on the physical and emotional burdens of patients with psoriasis. PMID- 19873692 TI - Preventing pressure ulcers on the heel: a Canadian cost study. AB - An adaptation of a clinical study of 130 patients at risk of developing a pressure ulcer on the heels was performed using Canadian costs. The aim of the study was to compare the cost effectiveness of a specially shaped hydrocellular dressing (Allevyn Heel) versus that of a protective heel bandage (Soffban and gauze) in pressure ulcer prevention over an 8-week period. PMID- 19873693 TI - What's your assessment? Invasive moderately differentiated squamous cell carcinoma. PMID- 19873694 TI - Tinea capitis: diagnostic criteria and treatment options. AB - Tinea capitis is a fungal infection involving the hair shaft of the scalp. It is commonly referred to as ringworm and occurs primarily in children. Treatment with a systemic anti-fingal rather than topical treatment is required. Currently, two medications, griseofulvin (Grifulvin) and terbinafine (Lamisil Granules), are FDA approved to treat tinea capitis. Treatment with griseofulvin is usually 6 to 8 weeks, while treatment with terbinafine requires 6 weeks. There are other medications currently not FDA-approved to treat tinea capitis that have similar cure rates and shorter durations of treatment for tinea capitis, and as a result, are being used off-label. The research-based literature related to the treatment of tinea capitis with various pharmacologic agents is reviewed. PMID- 19873695 TI - Allergic contact dermatitis. PMID- 19873696 TI - Exploring careers in dermatology. PMID- 19873697 TI - How many ABCDs should we know in dermatology? PMID- 19873698 TI - How to terminate a therapeutic relationship with a patient. PMID- 19873699 TI - Emerging therapies could help ease the chronic symptoms of atopic dermatitis for adults and children. PMID- 19873700 TI - New guidelines for managing psoriasis with systemic medications. PMID- 19873701 TI - Studies show combination laser therapy effective at clearing acne, reducing oil production. PMID- 19873702 TI - Bioengineered skin and stem cells show promise in treatment of non-healing wounds. PMID- 19873703 TI - Potential new treatment for patients with severe chronic hand eczema. PMID- 19873704 TI - Match game. Calif. groups eye federal Medicaid dollars. PMID- 19873705 TI - Seismic mandate deadline near. Calif. hospitals lack money to meet building codes. PMID- 19873706 TI - Symptoms of distress. PMID- 19873707 TI - The next makeover. Reformers want revamped role for managed care. PMID- 19873708 TI - [A comparison of endoscopy-assisted and conventional partial-superficial parotidectomy]. AB - OBJECTIVE: To investigate the feasibility of endoscopy-assisted partial superficial parotidectomy. METHODS: 38 cases with benign tumors located in the superficial lobe of the parotid gland were randomly assigned to receive conventional (20 cases) or endoscopic (18 cases) partial-superficial parotidectomy. Two short incisions, which were 2 to approximately 2.5 cm in length and located at retromandibular and postauricular area, were adopted for endoscopy-assisted surgery. The facial nerve was dissected through retrograde approach. RESULTS: The tumors were successfully resected with endoscopy in 18 cases. The operation time was not significantly different between the conventional and endoscopy-assisted procedures (P > 0.05). The intraoperative blood loss was markedly lower in endoscopy-assisted group, compared with conventional group (P < 0.01). All the 18 cases with endoscopy-assisted surgery were satisfactory with the postoperative cosmetic results. The great auricular nerve was preserved very well in 12 patients (66.6%). Transient facial paralysis happened in 1 case and relieved 1 month later. Salivary fistula occurred in 1 case and recovered after dressing with pressure for 2 weeks. All the patients were followed up for 24 to approximately 50 months (mean, 39 months) without relapse. CONCLUSIONS: Endoscopy-assisted partial-superficial parotidectomy can successfully treat benign tumors located in the superficial lobe of parotid gland with a better postoperative cosmetic result. PMID- 19873709 TI - [The clinical application of parotid fascia-SMAS-platysma flap in the lifting of lower face and neck]. AB - OBJECTIVE: To investigate the technique of lower face and neck lifting with parotid fascia-SMAS-platysma flap. METHODS: To improve the lifting strength of SMAS and the cosmetic result, the traditional SMAS-platysma flap was modified as parotid fascia-SMAS-platysma flap. The modified flap was folded and suspended step by step to lift the lower face and neck. RESULTS: From Oct. 2004 to Oct. 2008, 78 patients were treated with this method. The patients' age ranged from 40 to 65 years old. There were 2 cases of male and 76 cases of female. All the patients were followed up for 6 months to 4 year with satisfactory results. CONCLUSIONS: Folding and suspension of the parotid fascia-SMAS-platysma flap step by step can effectively lift the saggy tissue of lower face and neck. PMID- 19873710 TI - [Repairing alar defects by using a retro-grade island auricle composite tissue flap based on the interconnection of superficial temporal artery and posterior auricular artery]. AB - OBJECTIVE: To investigate the application of reverse island auricular composite tissue flap based on the superficial temporal artery for alar defects. METHODS: 16 cases with alar defects were treated with reverse island auricular composite tissue flap based on the superficial temporal artery. RESULTS: All the composite auricular flaps survived with primary healing. The patients were followed up for half a year to four years. The survived composite flaps had a similar color, texture and appearance as normal alar. The cosmetic result was satisfactory. CONCLUSIONS: Reverse island auricular composite tissue flap based on the superficial temporal artery is very suitable for alar defects. PMID- 19873711 TI - [Application of titanium mesh and free forearm flap for reconstruction of maxillary defect resulted from tumor resection]. AB - OBJECTIVE: To investigate the application of titanium mesh and free forearm flap for reconstruction of maxillary defect resulted from tumor resection. METHODS: From 2004 to 2008, 19 cases with maxillary tumor underwent tumor resection. The defects were reconstructed immediately with titanium mesh for bony defects and free forearm flap for oral mucosa defects. RESULTS: 16 cases achieved satisfactory functional and cosmetic results. The speech assessment was good without oronasal reflux. The titanium mesh was exposed and infected in 3 cases. Then the meshes were taken out and the defects were covered with the forearm flap to close the oronasal fistula. The midface was slightly depressed with no functional morbidity. CONCLUSIONS: It is simple and practical to reconstruct maxillary defect with titanium mesh and free forearm flap. Both the functional and cosmetic results are satisfactory. PMID- 19873712 TI - [Application of quantitative tissue expansion in ear reconstruction]. AB - OBJECTIVE: To explore the application of tissue expander in ear reconstruction and to deal with the complications. METHODS: 50 ml kidney-shape tissue expanders were implanted subcutaneously in the mastoid area. The drainage tube was removed 3 days after operation. The suture was removed 10 days later. Since 7 days after operation, 5 ml NS was injected into the expander every time, three times a week. The total injection volume was about 60 ml. After that, the expander was maintained for one month. RESULTS: From January 1992 to December 2006, 5,248 patients of microtia were treated with 6,252 expander. After the maintaining period, the expanded skin was thin and well-vascularized. The complication rate was 7.79%, including hematoma, malunion and infection. CONCLUSIONS: The quantitative tissue expansion is easily manipulated with few complications. It can provide hairless, thin skin with reliable blood supply for ear reconstruction. PMID- 19873713 TI - [Repair of defects at the end of fingers with island flaps pedicled with digital artery]. AB - OBJECTIVE: To investigate the therapeutic effect of island flaps pedicled with digital artery for the defects at the end of fingers. METHODS: 63 cases with 72 soft tissue defects at the end of fingers were treated with the island flaps. The flap size ranged from 8 mm x 11 mm to 21 mm x 27 mm. RESULTS: All the flaps survived completely. The follow-up period ranged from 4 to 19 months. The functional and cosmetic results were satisfactory. The two-point discrimination was 7 to approximately 9 mm. The TAM functional examination showed excellent in 59 fingers, good in 11 fingers and common in 2 fingers. CONCLUSIONS: The technique with island flap is simple and reliable for the defects at the end of fingers. PMID- 19873714 TI - [Clinical application of reverse island flap based on tibial planter digital artery]. AB - OBJECTIVE: To study the therapeutic effect of reverse island flap based on tibial plantar digital artery for soft tissue defect at the distal end of first toe. METHODS: 18 cases with soft tissue defect at the distal end of first toe were treated with reverse island flap based on tibial plantar digital artery. RESULTS: The patients were followed up for 6 to approximately 12 months (mean 9.5 months). All the flaps survived completely with good functional and cosmetic results. CONCLUSIONS: The reversed island flap based on tibial plantar digital artery has a reliable blood supply and is adjacent to the recipient area. It is practical and suitable for soft tissue defect at the distal end of first toe. PMID- 19873715 TI - [Free peroneal artery perforator sural neurocutaneous flap for hand and foot defects]. AB - OBJECTIVE: To report the operative techniques and clinical results of the free peroneal artery perforator sural neurocutaneous flaps. METHODS: Free sural neurocutaneous flap with a single unit of perforating veins and artery arising from the peroneal artery was designed to repair skin defects of hand or from the ankle to distal end of the foot. After the flap was transposed to the defect, the perforating artery was anastomosed with a branch of a nearby artery, and the small saphenous vein was anastomosed with the cephalic vein or the great saphenous vein to establish the flap's circulation. An alternative way was to anastomose the perforating vessels only. The sural nerve was anastomosed to innervate the flap. RESULTS: From Jan 2005 to Dec 2007, 12 cases were treated with the flaps with no flap necrosis. The size of the flaps ranged from 12 cm x 7 cm to 18 cm x 11 cm. The follow-up period was 7 to 27 months. Both the cosmetic and functional results were satisfactory. Two point discrimination was 7 to approximately 12 mm. CONCLUSIONS: The flap has all the advantages of the free flap, the perforator flap and the neurocutaneous flap. It is easily performed with reliable blood supply. It's a good choice for repairing the skin defects of hands and feet. PMID- 19873716 TI - [Repair of skin defects at forepart of feet with reverse saphenous nerve neurocutaneous flaps]. AB - OBJECTIVE: To investigate the effect of reverse saphenous nerve neurocutaneous flaps for skin defects at forepart of feet. METHODS: From January 2004 to October 2008,15 cases of skin defects at forepart of feet were repaired with reverse saphenous nerve neurocutaneous flaps. The flap size ranged from 3.5 cm x 3.0 cm to 8 cm x 5 cm. The wounds at donor site were closed with skin graft. RESULTS: All the flaps survived completely with no ulcer at the donor site. 10 patients were followed up for 1 to approximately 9 months. The skin color and texture were satisfactory. The patients could walk very well. CONCLUSIONS: It is reliable to repair the skin defects at forepart of feet with reverse saphenous nerve neurocutaneous flaps. It is easily performed with less morbidity. PMID- 19873717 TI - [Central wedge resection and asymmetric Z-plasty for minor labia reduction]. AB - OBJECTIVE: To investigate the therapeutic effect of central wedge resection and asymmetric Z-plasty for minor labia reduction. METHODS: Based on the Giraldo procedure, the incision was designed and the redudent tissue was resected quantitatively. The Z-plasty was modified to rectangle flap with deviated incision. The incisions at the two surface of minor labia were designed in an opposited direction. The two rectangle flaps were inserted to form the free edge of minor labia. RESULTS: 11 cases of minor labia hypertrophy were treated with good results. CONCLUSIONS: The modified procedure is easily performed with precise design. It is suitable for all kinds of minor labia hypertrophy. PMID- 19873718 TI - [Middle & distal circum peeling with bleeding control technique for redundant prepuce]. AB - OBJECTIVE: To investigate the middle and distal circum peeling with bleeding control technique for redundant prepuce. METHODS: The middle and distal part of prepuce was circum peeled with bleeding control and electrical scalpel. More preputial inner plate was reserved. RESULTS: From January 2004 to July 2008, 51 patients with redundant prepuce were treated with this procedure. The average blood loss was 1 to approximately 2 ml with minimal edema. The proportion of inner and outer plates was suitable. CONCLUSIONS: This technique has the advantages of minimal blood loss and slight edema. The cosmetic result is also satisfactory. PMID- 19873719 TI - [Expression of insulin-like growth factor-1 and alkaline phosphatase in the reconstruction of cleft palate with distraction osteogenesis in rhesus]. AB - OBJECTIVE: To investigate the osteogenesis mechanism by analysis of the expression of insulin-like growth factor-I (IGF-1) and alkaline phosphatase (ALP) in the reconstruction of cleft palate (CP) with distraction osteogenesis (DO) in rhesus. METHODS: The CP animal models were established surgically. 21 rhesus in experimental group underwent DO to close the soft and bony defect, followed by consolidations. Every 3 animals were killed and the specimen were taken out after consolidation of 1, 2, 4, 6, 8, 12, 24 weeks. The mRNA of IGF-1 and ALP were detected with Real-time RT-PCR technique. The expression of IGF-1 and ALP was quantitatively analyzed by ELISA. The results were compared with those in control and sham groups (each of 2 animals), respectively. RESULTS: Since consolidation, the mRNA of IGF-1 and ALP increased significantly at one week and reached the peak at two weeks, but decrease to control level after 12 weeks of consolidation. The expression of IGF-1 also increased to peak level after two weeks of consolidation. The expression of ALT increased significantly since consolidation and reach the peak value after six weeks. They all decreased to nearly control level after 8-12 weeks. CONCLUSIONS: The palate cleft can be successfully closed with new formed bone after DO. The mechanism of bone consolidation is intramembranous bone formation. PMID- 19873720 TI - [An ultrastructure study on the palatomaxillary suture of dog expanded by NiTi SMA]. AB - OBJECTIVE: To explore the ultrastructure of the palate-maxillary sutures under tensile forces by transmission electron microscope (TEM). METHODS: The Suture expanders were made in NiTi-Shape memory alloy (NiTi-SMA). The maximum force was 3.5 N. Fourteen 8-month old mongrel dogs were used in the study. They were divided into three groups, (1) experimental group, (2) control group, (3) sham group. In the experiment and control groups, an 8 mm wide cleft was made by surgery. The suture expanders were fixed onto the palatine bones of the experimental group. The dogs of the experimental group were executed after 3, 7, 14, 28, 56 days of suture expansion. The change of suture tissue was examined by TEM. RESULTS: The cleft of the experiment group were closed at the ninth day of expansion. At the beginning, tissue rupture, exudation, death of fibroblasts, disruption of collagen and tear vessels were seen at the early stage of suture expansion. Then highly active functional manifestations were seen in both osteocytic and fibrocytic populations. At last, normal structure restored. CONCLUSIONS: Cell types and functional condition could be distinguished clearly by TEM. It suggests that the suture expansion should be the process of tissue repair and regeneration. The suture cells response, especially, the osteogenic response were the major factor of increasing suture width. PMID- 19873722 TI - [Effect of botulinum toxin type A injection on hypertrophic scar in rabbit ear model]. AB - OBJECTIVE: To investigate the effect of botulinum toxin type A (Botox A) injection on hypertrophic scar in rabbit ear model. METHODS: The hypertrophic scar model was established in 16 Japanese rabbits' ears. These wounds were divided into two groups as group T (treated with Botox A, n = 48) and group S (not treated, n = 48). The wounds healing times and scar hypertrophy were observed with 8 specimen of normal skin at the rabbit ears as sham group B. HE stain was used to assess the hypertrophic index (HI). The expression of collagen I and III was tested by western-blot. The cell cycle of fibroblasts was studied by flow cytometry. RESULTS: The HI was significantly lower in group T than in group S (P < 0.01). The expression of collagen I and III, as well as the ratio of I to III, was markedly stronger in group S than in group T (P < 0.01). Compared with group T, more fibroblasts were in G2-M in group S and fewer in G0-G1 (P < 0.05). CONCLUSIONS: Local injection of Botox A can inhibit the formation of hypertrophic scar and the activity of fibroblasts in rabbit ear model. It can significantly decrease the expression of collagen I and III in hypertrophic scar, as well as the ratio of collagen I to III. It serves as the basis for the treatment of hypertrophic scar with Botox A. PMID- 19873721 TI - [Establishment of animal model for electroporation-mediated gene therapy in distraction osteogenesis of rabbit mandible]. AB - OBJECTIVE: To evaluate the feasibility of electroporation-mediated transfection of recombinant plasmid to mandibular distraction area of rabbit in vivo. METHODS: New-Zeland rabbit were employed. The mandible was distracted 3 days after operation at a rate of 0.8 mm per day for 7 days. The rabbits were randomly divided into 3 groups as group A (recombinant plasmid pIRES-VEGF165-EGFP), group B (recombinant plasmid plRES-VEGF165-EGFP) and group C (normal saline). The rabbits were sacrified at 3 hours, 1, 3, 7 and 14 d after injection respectively. The tissue at the distraction area was taken out for frozen section. The gene expression was assessed by the detection of expression of green fluorescence protein (GFP) using fluorescence microscope. The liver and kidney function test (ALT, AST, BUN, Scr) and the histological examination of heart, liver and kidney were also performed. RESULTS: GFP was seen in the distraction area in group A and group B 3 hours after injection, which increased at the 1st day, reached peak value at the 3rd day, decreased at the 7th day and was very lower at 14th day. The GFP expression was much stronger in group A than in group B. GFP was not expressed in group C. There was no statistical difference in the concentration of ALT, AST, BUN and Scr in serum of rabbits among the three groups. CONCLUSIONS: Electroporation-mediated transfection of recombinant plasmid can be expressed in the distraction area of rabbits, and there was no toxicity to the liver and kidney of rabbits. Electroporation could obviously improve transfection efficiency in vivo. It indicates that electroporation-mediated transfection of recombinant plasmid to distraction area tissue of rabbits is feasible. PMID- 19873723 TI - [Proliferation of the mesenchymal stem cells in a delayed fat flap: an experimental study in rabbits]. AB - OBJECTIVE: To investigate the possibility to enhance the proliferation of adipose derived stem cells (ASCs) in a delayed fat flap in rabbits. METHODS: A delayed fat flap was formed in one side of inguinal region of a rabbit. 21 days after operation, the fat tissues at the delayed flaps and at the unoperated side were harvested and digested with 0.25% collagenase and sieved. The cell suspensions were centrifuged. The cells were obtained from tissue precipitate after centrifugation. The expression rates of the surface marker (CD29, CD44, CD14 and CD45) were measured by FCM and compared between the experimental and control groups. RESULTS: Expression rates of CD29 and CD44 were higher in the delayed fat flap (74.06% and 90.74%) than in the contralateral fat tissue (62.88% and 77.54%, P < 0.05), while those of CD14 and CD45 were lower in the delayed fat flap (57.66% and 4.84%) than in the contralateral fat tissue (72.10% and 75.82%, P < 0.05 and P < 0.01). CONCLUSIONS: Tissue hypoxic ischemia such as fat tissue in a delayed fat flap can promote proliferation of ASCs. It indicates that tissue in the delayed flap may be transplanted with better survival rate. The ischemia pretreatment of fat tissue may become a new method for fat transplantation. PMID- 19873724 TI - [The change rules and correlation between specific leaf weight and dry weight of rhizoma of Atractylodes macrocephala]. AB - OBJECTIVE: To study the change rules of specific leaf weight, dry weight of rhizoma and the drying rate of annual and biennial Atractylodes macrocephala. METHODS: We measured the specific leaf weight and dry weight of rhizoma, and accounted the drying rate and correlation by dugging the annual and biennial plants each 15 days. There were 3 rhizoma types of biennial Atractylodes macrocephala with Drumstick/Frog type, Er-cha type and Wu-zi type. RESULTS: It showed the curve of specific leaf weight of annual plant was "N" style, which of biennial plant was linear. The dry weight and the drying rate of all rhizoma types increased point-blank during the whole growth period. CONCLUSION: The correlation between specific leaf weight and dry weight of rhizoma is obvious in biennial Atractylodes macrocephala but is contrary in annual Atractylodes macrocephala. PMID- 19873725 TI - [Isolation and pharmacological properties of analgesic fraction from venom of Naja Naja atra]. AB - OBJECTIVE: To separate main analgesic fraction from venom of Guangdong Naja naja atra, to establish the basis for the using of Naja naja atra and find new analgesic fraction. METHODS: Affinity chromatography and size exclusion were used to isolate the analgesic fraction from the venom of Naja naja atra, and then to determine its properties by biochemical methods, such as SDS-polyacryamide gel electrophoresis ( SDS-PAGE), HPLC and Mole-toff. RESULTS: HPLC showed its relative purity was 95% (HPLC)and Mw was 6741. 236 Da. We observed that peripheral administration of neurotoxin strongly reduced the mechanical allogynia and thermal hyperalgesia for 24 hours, associated with this neuropathy (L5 spinal nerve ligation). CONCLUSION: The fraction from venom of Naja naja atra has significant analgesic effect and it is worth further developing. PMID- 19873726 TI - [Study on the influence on Rhizoma Corydalis by different harvest time and processing methods]. AB - OBJECTIVE: To choose the best harvest time and initial processing method of Rhizoma Corydalis. METHODS: Taking the content of tetrahydropalmatine and dry rates as major indices, different samples from different harvest time and different processing methods were investigated by HPLC. The C18 column (250 mm x 4.6 mm, 5 microm) was used with mobile phase of methanol-0.1% phosphoric acid solution (pH = 6.0, adjusted with triethylamine) (58: 42). The mobile phase flow rate was 1.0 mL/min. The detection wavelength was 280 nm. RESULTS: The contents of tetrahydropalmatine were similar although the harvest time was different. The dry rate on May 21 was higher than the others. The content of tetrahydropalmatine was the highest by steaming and reached 0.11%. CONCLUSION: The best harvest time for Rhizoma Corydalis is around 10 days after the above-ground plant wilted, and the best initial processing method for Rhizoma Corydalis is steaming. PMID- 19873727 TI - [The determination of three effective constituents in wild and cultivated Gastrodia elata from Bomi]. AB - OBJECTIVE: To determine the contents of gastrodin, amino acids and total flavonoids in wild and cultivated Gastrodia elata, in order to choose the best method for its cultivation. The Gastrodia elata was picked at Guxiang town Bomi county Linzhi Region in Tibet. METHODS: HPLC was used to determine the content of gastrodin. The autoanalyzer was used to determine the content of amino acid. The ultraviolet spectrophotometer was adopted to measure the content of total flavonoids. RESULTS: The Gastrodin in wild Gastrodia elata was the highest. The contents of amino acids and total flavonoids in organic cultivated Gastrodia elata were higher than those in common cultivated and wild Gastrodia elata. CONCLUSION: The organic cultivated Gastrodia elata has better quality. PMID- 19873728 TI - [Study on the influence on the content of dehydrocavidine and total alkaloids in Corydalis saxicola by different drying methods]. AB - OBJECTIVE: To evaluate the influence of five different drying methods on the contents of dehydrocavidine, a main active constituent, and total alkaloids in Corydalis saxicola. METHODS: The whole plant samples of C. saxicola were harvested at its florescence stage, and then immediately divided into four parts of root, stem, leaf, and inflorescence. Each part of sample was dried by the following five methods, drying in a sunshine, drying in a shade, oven-drying at 60 degrees C, vacuum-drying at room temperature and frozen vacuum-drying, respectively. Then the contents of dehydrocavidine and total alkaloids were determined by RP-HPLC and ultraviolet spectrophotometry. RESULTS: The contents of dehydrocavidine and total alkaloids in all the four parts of the sample processed by drying in a shade were significantly higher than those in the samples processed by the other four drying mehods. CONCLUSION: Different drying methods could significantly influence the contents of dehydrocavidine and total alkaloids in C. saxicola. The process of drying in a shade for a long time would be the best. PMID- 19873729 TI - [Studies on the chemical constituents of Epimedium brevicornum]. AB - OBJECTIVE: To study the chemical constituents of Epimedium breviconum. METHODS: Compounds were purificated with various chromatographic techniques such as silica vacuum liquid chromatography and Sephadex LH-20 column chromatography. Their structures were elucidated by physico-chemical methods and spectral analysis. RESULTS: Ten compounds were obtained and indentified as (7R, 8S) 4,9-dihydroxyl 3,3'-dimethyoxyl-7, 8-dihydrobenzofunan-1'-propanolneolignan-9'-O-alpha-L rhamnopyranoside (1), (7R, 8S, 8' R) 4, 4', 8', 9-tetrahydroxyl-3, 3'-dimethyoxyl 7, 9'-monoepoxylignan (2), (+)-cycloolivil (3), (3, 5, 7, 4')-tetrahydroxyl-8 isopentene group flavonoids-3-O-alpha-L-rhamnopyranoside (4), beta-sitosterol (5), p-hydroxybenzaldehyde (6), succinic acid (7) and p-hydroxyphenethyl (8). CONCLUSIONS: Compound 1 is isolated from this genus for the first time. Compounds 2,3,5 -8 are isolated from the plant for the first time. PMID- 19873730 TI - [Study on the chemical constituents of the fruit handles from Schizandra chinensis]. AB - OBJECTIVE: To study the chemical constituents of the fruit handles from Schizandra chinensis. METHODS: Compounds from the 85% ethanol extracts were isolated by silica gel, Sephadex LH-20, recrystal, etc., and their structures were identified by the spectral analysis and chemical evidence. RESULTS: Eight compounds were isolated and identified as wuweizisu C (I), ganwuweizic acid(II), beta-sitosterol(III), gomisin A(IV), schizandrin(V), daucosterol(VI), wuweizisu A(VII), gamma-schizandrin (VIII). CONCLUSION: Compounds I - VIII are isolated from the fruit handles of Schizandra chinensis for the first time. PMID- 19873731 TI - [Study on the chemical constituents of Uvaria microcarpa]. AB - OBJECTIVE: To study the chemical constituents of Uvaria microcarpa. METHODS: The constituents were repeatedly separated and purified with silica gel column and Sephadex LH-20 column, and identified by physico-chemical properties and spectral methods. RESULTS: Nine compounds were separated and identified as beta-sitosterol palmitate (I), euphorginol (II), beta-sitosterol (III), benzoic acid(IV), stigmasterol-3-O-beta-D-glucopyranoside (V), taraxerol (VI), emodin (VII), aristololactam A II (VI), beta-daucosterol (IX) . CONCLUSION: Compounds I, II, V, V are isolated from this plant for the first time. PMID- 19873732 TI - [Studies on triterpenoid saponins in the rhizome of Anemone flaccida]. AB - OBJECTIVE: To study the triterpenoid saponins in the rhizome of Anemone flaccida. METHODS: The constituents were separated with various chromatographic techniques and their structures were elucidated by means of physicochemical properties and the analysis of their spectral datas. RESULTS: Five compounds were isolated and identified as 3-O-beta-D-glucuronypyranosyl-oleanolic acid-28-O-alpha-L rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl(1 --> 6)-beta-D-glucopyra noside (1), 3-O-beta-D-glucuronypyranosyl-oleanolic acid-28-O-beta-D-glucopyranosyl (1 - > 6)-beta-D-glucopyranoside (2), 3-O-alpha-L-rhamnopyranosy (1 --> 2)-beta-D glucopyranosyl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 --> 4)-beta-D glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (3), 3-O-alpha-L-rhamnopyranosyl (1 --> 2)-alpha-L-arabinopyrano-syl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 -->4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (4), 3-O-alpha-L rhamnopyranosyl (1 --> 2)-beta-D-xylopyranosyl-oleanolic acid-28-O-alpha-L rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (5). CONCLUSION: Compound 1 - 4 are isolated from this plant for the first time. Compound 1,2 are isolated from this genus for the first time. PMID- 19873733 TI - [Study on the constituents of petroleum ether fraction of Buxus microphylla]. AB - OBJECTIVE: To study the chemical constituents from the petroleum ether fraction of Buxus microphylla. METHODS: The petroleum ether fraction of Buxus microphylla was isolated and identified by silica gel column chromatography. And the anticancer activity of different chemical constituents was measured by MTT reduction test. RESULTS: Eight compounds were isolated and identified as lupeol (1), butulin (3), beta-sitosterol (4), stigmasterol (5), dibutyl phthalate (6), 3beta, 30-dihydroxy-lup-20 (29) ene (7), daucosterol (8). Compound 7 inhibited KB cells' proliferation in a dose-dependent manner. CONCLUSION: Compounds 2 - 5, 7, 8 are isolated from this genus for the first time. Compound 7 has certainly anticancer effects. PMID- 19873734 TI - [Studies on the chemical constituents of Blumea laciniata]. AB - OBJECTIVE: To study the chemical constituents of Blumea laciniata. METHODS: The chemical constituents of the ethyl acetate fraction of ethanol extract from Blumea laciniata were isolated with column chromatographic techniques. The structures of the isolated compounds were elucidated by spectroscopic analysis and comparison with their published datas. RESULTS: Five compounds were isolated and identified as: protocatechuic acid (1), chrysoeriol (2), apigenin (3), 4 hydroxy-3,5-dimethoxbenzoic acid (4), scopolet (5). CONCLUSION: Compounds 1 - 5 are isolated from this plant for the first time, and also obtained from this genus for the first time. PMID- 19873735 TI - [Structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity]. AB - OBJECTIVE: To study the structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity. METHODS: By the assay systems of DPPH*, the antioxidant activity of six phenylethanoid glycosides from plants of Cistanche salsa was determined to investigate the relationship between the antioxidant activities and phenylethanoid glycosides's structural characteristics. RESULTS: The antioxidative activity of phenylethanoid glycosides was variant with dose-dependent effect. The sequence of the strength of the antioxidative activity of the six components was shown to be 2' Acetylacteoside > Acteoside > or = Tubuloside B > or = Isoacteoside > Echinacoside > Cistanoside A. CONCLUSION: The antioxidative activity of phenylethanoid glycosides is related to the number of phenolic hydroxyl, steric hindrance, 2-acetyl on the middle glucopyranose, and the location of phenolic hydroxyl. Additionally, it may be related to the alpha, beta-unsaturated ketone of phenl-2-propenoyl. PMID- 19873736 TI - [Effects of Yi Fu Ning soft gelatin capsules on reproductive endocrine-immune function of ovariectomized rats]. AB - OBJECTIVE: To investigate the effect of Yi Fu Ning Soft Gelatin Capsules (YFN) on reproductive endocrine-immune function of ovariectomized rats. METHODS: 60 3 month old female Sprague-Dawley rats were used, 50 of them were ovariectomized and randomly divided into 5 groups: ovariectomizy (OVX) group, OVX with diethylstilbestrol tablets (DT) group, OVX with YFN (high dose, middle dose and low dose) group. The others were sham-operated group. The rats were administrated initially in the 4th week after the operation. After drugs had been given for 12 weeks the rats were sacrificed, blood serum hormone, IL-2 content and T lymphocyte subpopulation were detected with methods radioimmunoassay and flow cytometry (FCM). RESULTS: (1) Compared with sham group, the level of serum E2, Te and P significantly decreased (P < 0.01), FSH, LH content significantly increased; Blood T lymphocyte subpopulation CD3+ cells, CD4+ cells and CD4+/CD8+ ratio significantly decreased, serum IL-2 content also significantly decreased (P < 0.01). (2) Compared with model group, after treated by YFN, the level of serum E2 and P significantly increased (P < 0.01), serum FSH and LH content significantly decreased; T lymphocyte subpopulation CD3+ cells, CD4+ cells and CD4+/CD8+ ratio were improved significantly and serum interleukin-2 (IL-2) content increased significantly. CONCLUSION: YFN can increase serum sexual hormone content,reduce the level of FSH and LH, and improve imbalanced T lymphocyte subpopulation, stimulate IL-2 excretion, which means YFN can regulate inordinate reproductive endocrine-immune network in ovariectomized rats. PMID- 19873737 TI - [Determination of the eliminating ratio of TCM polysaccharide to hydroxyl radical by kinetic fluorescent spectrophotometry]. AB - OBJECTIVE: To explore reaction dynamic of hydroxyl radical (*OH) and salicylic acid,and to determine the elimination ratios of TCM polysaccharide to *OH by kinetic fluorescent analysis. METHODS: The impact dynamics factors of this reaction were studied by fluorescent, such as the reaction of concentration, reaction time and temperature. The dynamical equation was built, a kinetic fluorescent spectrophotometry based on the reaction was developed to determine the elimination ratio. Repetitiveness and reliability of this method were tested by vitamin C. RESULTS: The dynamical equation of reaction rate to salicylic acid was gamma = 0. 9818x -1. 1801 under the condition of lambda ex = 295 nm, lambda em = 411 nm at room temperature, r approximately 1. The 50% elimination ratio (IC50) of TCM polysaccharide of Tangerine peel and Ganoderma lucidum to *OH was 78.01 mg/L and 232.5 mg/L, respectively. The IC50 of vitamin C was 24.52 microg/L, RSD was 0.23% (n = 5). CONCLUSIONS: The method is sensitive and reliable, it can be used to determine the elimination ratio of TCM polysaccharide to *OH. PMID- 19873738 TI - [Effects of total flavonoids from Rhizoma Drynariae medicated serum on proliferation, differentiation, cell cycle and apoptosis of osteoblasts in vitro]. AB - OBJECTIVE: To observe the effects of total flavonoids from Rhizoma Drynariae medicated serum on cell proliferation, differentiation, cell cycle and apoptosis of rats' osteoblasts cultured in vitro. METHODS: The osteoblasts from cranium of newborn SD rats were cultured by collagenase method. MTT, PNPP, PI and Annexin V/PI methods were used to observe the proliferation, activity of alkaline phosphatase (ALP), every stage cells in the cell cycle, and the ratio of apoptosis cells by different concentrations of total flavonoids from Rhizoma Drynariae medicated serum at different time points. RESULTS: Different concentrations of total flavonoids from Rhizoma Drynariae medicated serum could significantly enhance the cell proliferation rate and ALP activity (P < 0.05), more cells in S stage and less cells apoptosised than that of the untreated osteoblasts (P < 0.05). CONCLUSION: Total flavonoids from Rhizoma Drynariae medicated serum could promote the proliferation, differentiation, increase S stage cells, and reduce the ratio of apoptosis cells, which reveals that they have anti-osteoporosis activity. PMID- 19873739 TI - [Effects of Tankejing dry powder inhaler on the inflammatory damage in the lungs of mice infected by FM1]. AB - OBJECTIVE: To study the effect of Tankejing Dry Powder inhaler on inflammatory in lung injury of mice infected by influenza virus (FM1). METHODS: Model mice infected by influenza virus FM1 were randomly divided into six groups: the nomal group, model group, low dose, medium dose and high dose of Tankejing Dry Powder inhaler group,and Ribavirin group. The following indices including the change of NF-kappaB in lung tissue at 24 h, the changes of TNF-alpha, IL-1beta, IL-6 in lung tissue, the lung index and the death rate were observed. RESULTS: Compared with model group, medium and high dosages of Tankejing Dry Powder inhaler could modulate the expression of NF-kappaB, reduce the level of TNF-alpha, IL-beta, IL 6 in lung tissue (P < 0.05), and reduce the lung index and the death number of animals within 14 days (P < 0.05). CONCLUSION: Tankejing Dry Powder inhaler may reduce the inflammatory injury caused by influenza virus FM1 through regulating the expression level of NF-kappaB and cytokine. PMID- 19873740 TI - [The effect of gallic acid extracted from leaves of Phyllanthus emblica on apoptosis of human hepatocellular carcinoma BEL-7404 cells]. AB - OBJECTIVE: To explore the effect of gallic acid extracted from Leaves of Phyllanthus emblica on the apoptosis of BEL-7404 cells. METHODS: MTT assay was applied to detect the influence on prolifetation in vitro. Inverted microscope was utilized to observe the morphological changes after BEL-7404 cells were treated with gallic acid. Annexin V/PI double label method was used to detect earlier period apoptosis cells and Tunel was applied to calculate the apoptosis rates. RESULTS: Gallic acid could restrain the BEL-7404 cells proliferation at diffierent levels in a time and concentration dependent manner. The typical morphological changes of apoptosis were observed after BEL-7404 cells were treated with gallic acid. Annexin V/PI double label method and Tunel method showed that the viable apoptotic cell and apoptosis rates added as action time prolonged. CONCLUSION: Gallic acid can restrain the BEL-7404 cells proliferation and induce apoptosis, and its effect on apoptosis is time dependent. PMID- 19873741 TI - [Study on refining process of Flos Chrysanthemi extract with macroporous resin]. AB - OBJECTIVE: To determine the parameters of refining process of Flos Chrysanthemi extract with macroporous adsorption resin. METHODS: According to the chlorogenic acid and total flavonoids, to investigate the kind of macoroporous resin, the maximum quantity of physic liquor, and the type and quantity of elution solvent. Then combining with the retention rate of luteolin, to verify the parameters of the process. RESULTS: The maximum adsorption quantity of chlorogenic acid was 10.8 mg/g dry resin, and the elution solvent was 5-fold column volume of 80% alcohol; the purity of total flavonoids, chlorogenic acid and luteolin were 589.2%, 605.4%, 650.1%, respectively. CONCLUSION: The resin F can enrich the active components of Flos Chrysanthemi effectively. PMID- 19873742 TI - [Comparison of microwave-assisted and conventional extraction of Corydalis yanhusuo]. AB - OBJECTIVE: To compare the extraction yield and economic cost in the microwave assisted extraction and conventional extraction of Corydalis yanhusuo. METHODS: Both of the extractions of Corydalis yanhusuo were optimized by orthogonal design. The contents of tetrahydropalmatine and total alkaloids were determined by HPLC and ultraviolet spectrophotometer, respectively. Meanwhile, the electricity consumption was determined in the extraction process. RESULTS: Comparing with conventional extraction, the microwave-assisted extraction saved time and money, and provided higher extraction yield of tetrahydropalmatine and total alkaloids. CONCLUSION: The microwave-assisted extraction has advantages in high efficiency and low cost. PMID- 19873743 TI - [Study on fingerprint of Maodongqing injection by HPLC]. AB - OBJECTIVE: To establish the fingerprint of Maodongqing injection by HPLC. METHODS: The column of ODS-2 Hypersil C18 (4.6 mm x 200 mm, 5 microm) was used. The mobile phase consisted of acetonitrile-0.05% phosphoric acid with gradient elution. The flow rate was 1 mL/min, the column temperature was 30 degrees C, and the detection wavelength was 325 nm. RESULTS: The fingerprint of Maodongqing injection was established, and 8 samples of different batches of Maodongqing injection were detected. Thirteen peaks in the chromatogram were marked by "Similarity Evaluation System for Chromatographic Fingerprints of Traditional Chinese Medicine (Version 2004 A)". There was a high similarity and each chromatographic peak was obtained with good separation and correlation according to the technical requirements of the fingerprints of Chinese traditional medicine. CONCLUSION: This method is accurate, reliable and provides a scientific basis for controlling the quality of Maodongqing injection. PMID- 19873744 TI - [HPLC determination of rhynchophylline and isorhynchophylline in Anshen Yangxue oral liquid]. AB - OBJECTIVE: To establish the method for determining rhynchophylline and isorhynchophylline in Anshen Yangxue oral liquid. METHODS: Rhynchophylline and isorhynchophylline were determined by HPLC. The chromatographic conditions were composed of Kromasil C18 column (5 microm, 4.6 mm x 250 mm), a mixture of methanol and water (55: 45) as mobile phase with 0.01 mol/L triehthylamine, adjusted with acetic acid to pH 7.5. The UV detection wavelength of rhynchophylline and isorhynchophylline was 254 nm. RESULTS: The average coveries of rhynchophylline and isorhynchophylline were 99.04% and 98.75%, respectively. When rhynchophylline's injection quantity between 0.12 - 1.20 microg and isorhynchophylline's injection quantity between 0.08 -0.80 microg, there were good linear relationships (r1 = 0.9999, r2 = 0.9993). CONCLUSION: This method is simple, sensitive, accurate and can be used for the quality control of Anshen Yangxue oral liquid. PMID- 19873745 TI - [Regulations diversity of fungal copper homeostasis--a review]. AB - Copper is an essential trace element in all organisms and serves as a catalytic cofactor for many biological processes in cells. Yet excess cuprous and cupric forms can be high toxic to the cells. Thus cells must have developed diverse mechanisms to control the uptake and distribution of copper. Much are known about the copper metabolism in Saccharomyces cerevisiae and a few other fungi. In this review, we focus on the recent research in copper uptake, transport and distribution in model organism baker's yeast Saccharomyces cerevisiae, as well as the new frontier in other fungi, e.g., the novel roles of copper in the pathogenesis of the fungal pathogen Cryptococcus neoformans. PMID- 19873746 TI - [Type III secretion system of Vibrio parahaemolyticus--a review]. AB - Vibrio parahaemolyticus is a halophilic gram-negative bacterium that causes food borne acute gastroenteritis in human being or certain diseases in aquatic species. In addition to thermostable direct hemolysin (tdh) and tdh-related hemolysin (trh), two sets of type III secretion systems (T3SS) were recently found to be associated closely with virulence. T3SS1 located on chromosome 1 is involved in cytotoxicity to host cells and orchestrates a multifaceted host cell infection by induction of autophagy, cell rounding, and eventual cell lysis. T3SS2 in chromosome 2 is enterotoxic. In this we address the composition of the two T3SS, their functions and regulation in Vibrio parahaemolyticus. PMID- 19873747 TI - [Quorum sensing and its roles in pathogenesis among animal-associated pathogens- a review]. AB - Quorum sensing (QS) is a phenomenon that microbes regulate some of their genes by signals related to the density of population. It is confirmed that acyl homoserine lactones (AHL), some peptides, some furanones and some other small moleculars can be used as quorum-sensing signals by microbes. Microbes control their physiology with different QS systems in parallel or hierarchical ways. A lot of microbial pathogenesis connect with quorum sensing closely. More and more studies show that QS systems regulate microbial pathogenesis through the following points: (1) QS helping pathogens invasion and colonization; (2) QS regulating production of virulent factor; (3) QS giving pathogens the ability of immunity or drug resistance. We review the role of QS in microbial pathogenesis and address a new way to prevent and control microbial diseases. PMID- 19873748 TI - [Phylogenetic diversity of the culturable rare actinomycetes in marine sponge Hymeniacidon perlevis by improved isolation media]. AB - OBJECTIVE: Based on the molecular diversity information, seven actinomycete selective culture media and isolation conditions were modified to isolate and cultivate diverse rare actinomycetes from Hymeniacidon perlevis. METHODS: Modified, selective cultivation and enrichment media were used, with the addition of an elemental solution of simulating the elemental composition of marine sponge H. perlevis. Restriction Fragment Length Polymorphism (RFLP) analysis of 16S rDNA sequence was used to reveal the diversity of culturable rare actinomycetes. RESULTS: A total of 59 actinomycete strains were isolated from the marine sponge H. perlevis. A total of 27 representative actinomycetes were selected according to their morphological feature, color and pigments. They gave 15 different RFLP patterns after digesting their PCR products of 16s rDNA with Hha I. The results showed that these isolates belonged to 10 genera: Streptomyces, Nocardiopsis, Micromonospora, Cellulosimicrobium, Gordonia, Nocardia, Prauseria, Pseudonocardia , Saccharomonospora and Microbacterium. CONCLUSION: The modified isolation media and selective cultivation procedures are highly effective in the recovery of culturable actinomycetes from the marine sponge H. perlevis, resulting in the highest diversity of culturable rare actinomycetes from any sponges. PMID- 19873749 TI - [Genetic diversity of cultivable bacteria of dominant plants in a potassium mine tailing of Nanjing]. AB - OBJECTIVE: Plant rhizosphere bacteria play an important role in biogeochemical cycles. Microbial diversity of cultivable bacteria from soil-plant-mineral system in a mine tailing was assessed. METHODS: Cultivable bacteria were isolated by plating and screening from plant root, rhizosphere and bulk soils of predominant plants in a mine tailing of Nanjing, Jiangsu Province. Phylogenetic analyse based on 16S rDNA sequence comparisons and amplified rDNA restriction analysis of isolates were investigated. RESULTS: In total, 60 pure cultures were isolated; they could be grouped into 18 different operational taxonomic units (OTU) at the similarity level of 60%. Nineteen bacterial strains belonged to eleven genera (Rhizobium, Pseudomonas, Pantoea, Arthrobacter, Microbacterium, Bacillus, Paenibacillus, Acinetobacter, Sphingomonas, Kocuria , Mitsuaria) of three major phylogenetic groups (Proteobacteria, Actinobacteria, Firmicutes). Rhizobium, Pseudomonas and Pantoea were the dominant groups. CONCLUSION: Different cultivable bacteria inhabited in roots and soils of dominant plants in the mine tailing. They might play a certain role in the soil-plant-mineral environment. PMID- 19873750 TI - [Roles of OxyRxoo, a transcriptional regulator of Xanthomonas oryzae pv. oryzae in regulation of detoxification of hydrogen peroxide]. AB - OBJECTIVE: OxyRxoo is a homologue of OxyR from Xanthomonas oryzae pv. oryzae (Xoo), the pathogen of bacterial blight of rice. To elucidate the role of OxyRxoo in detoxification of hydrogen peroxide. METHODS: OxyRxoo was studied by gene cloning, sequencing, deletion,complement and phenotype analysis. RESULT: Compared to those of the wild-type strain PXO99(A), there was no difference in bacterial growth in vitro of delta oxyRxoo, but delta oxyRxoo is more sensitive to H2O2 with reduced catalase activity. In the presence of H2O2, the expression of catalase genes (ahpCxoo, catBxoo, katExoo and srpAxoo) was significantly down regulated, while the expression of oxyRxoo was up-regulated in delta oxyRxoo. CONCLUSION: OxyRxoo functions as a transcription regulator in mediating and controlling H2O2 detoxification in Xoo. PMID- 19873751 TI - [Expression and optimization of anti-AFB1 scFv in Escherichia colil]. AB - OBJECTIVE: A drawback of the expression of single chain antibody fragment (scFv) in prokaryotic system is the protein accumulation in the cytoplasm as inclusion body. We aimed at high-level production of an anti-aflatoxin B1 scFv in functional form. METHODS: The gene of scFv-H4 was cloned into pET22b vector and transformed into E. coli BL21(DE3) and Origami (DE3),respectively. The amount of functional scFv-H4 was optimized in terms of IPTG concentration and induction temperature. RESULTS: scFv-H4 could be expressed in both BL21(DE3) and Origami (DE3). Compared with BL21(DE3), Origami(DE3) could express multifunctional scFv H4 (35 mg/mL) and less in inclusion body (11% of the total expression). The expression of scFv-H4 was significantly affected by induction temperature rather than IPTG concentration. CONCLUSION: The pET22b could be used for high-level expression of the functional scFv-H4 in Origami (DE3), which has an oxidative cytoplasm. In addition,the induction at low temperature avoided the formation of inclusion body. PMID- 19873752 TI - [Identification and analysis of an actinomycete strain suppressing Clavibacter michiganensis subsp, michiganensis]. AB - OBJECTIVE: To identify and analyze bioactive compounds of an actinomycete strain Z-L-22 suppressing Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker of tomato. METHODS: Morphological, biological and biochemical characterization, chemotaxonomy analysis and 16S rDNA sequences homology analysis were performed to identify the strain Z-L-22. Bioactive compounds were separated and retrieved by thin layer chromatography. Paper chromatography and confirmation tests were used to identify the antibiotic. PCR was carried out using the primers targeted to synthetase of the antibiotic. RESULTS: Strain Z-L-22 belonged to Streptomyces sp. and was similar to Streptomyces setonii. Two main bioactive components were isolated by thin layer chromatography, which were all identified as actinomycin. New actinomycin synthetase gene was cloned using the primers designed from actinomycin synthetase conserve domain. CONCLUSION: Strain Z-L-22 was classified as Streptomyces setonii. Actinomycin produced by Streptomyces setonii was first reported. PMID- 19873753 TI - [Isolation and characterization of a marine agarase]. AB - OBJECTIVE: This study was carried out to isolate and characterize an agarase from a marine bacterium Agarivorans albus QM38. METHODS: SDS-PAGE grade agarase was obtained from the fermentation broth after removing the bacteria by centrifugation, ammonium sulfate precipitation, DEAE-sepharose fast flow anion exchange chromatography and Sephacryl S-100 gel filtration. Enzyme's molecular weight was determined with SDS-PAGE. The catalysates of the isolated enzyme were determined withmass spectrography. RESULTS: Agarase A was isolated. The molecular weight of agarase A was 127.80 kDa. More characterizations of agarase A were studied and the results showed that the optimal reaction condition for agarase A was at 35 degrees C, pH 7.6, and agar concentration of 0.9% (w/v), while most of the metal ions inhibited the activity of it. The catalysates of agarase A were mainly tetrose and hexose. CONCLUSION: Agarase A was purified from the medium. It could hydrolyze jellied agar and yield simple catalysates. Its molecular weight is different from all the agarases reported so far. PMID- 19873754 TI - [Predominant strains of polycyclic aromatic hydrocarbon-degrading consortia from deep sea of the Middle Atlantic Ridge]. AB - OBJECTIVE: In order to identify the predominant strains of polycyclic aromatic hydrocarbon (PAH)-degrading consortia harboring in sea water and surface sediment collected from deep sea of the Middle Atlantic Ridge. METHODS: We employed enrichment method and spread-plate method to isolate cultivable bacteria and PAHs degraders from deep sea samples. Phylogenetic analysis was conducted by 16S rRNA gene sequencing of the bacteria. Then we analyzed the dominant bacteria in the PAHs-degrading consortia by denaturing gradient gel electrophoresis (DGGE) combined with DNA sequencing. RESULTS: Altogether 16 cultivable bacteria were obtained, including one PAHs degrader Novosphingobium sp. 4D. Phylogenetic analysis showed that strains closely related to Alcanivorax dieselolei NO1A (5/16) and Tistrella mobilis TISTR 1108T (5/16) constituted two biggest groups among the cultivable bacteria. DGGE analysis showed that strain 4L (also 4M and 4N, Alcanivorax dieselolei NO1A, 99.21%), 4D (Novosphingobium pentaromativorans US6-1(T), 97.07%) and 4B (also 4E, 4H and 4K, Tistrella mobilis TISTR 1108T, > 99%) dominated the consortium MC2D. While in consortium MC3CO, the predominant strains were strain 5C (also 5H, Alcanivorax dieselolei NO1A, > 99%), uncultivable strain represented by band 5-8 (Novosphingobium aromaticivorans DSM 12444T, 99.41%), 5J (Tistrella mobilis TISTR 1108T, 99.52%) and 5F (also 5G, Thalassospira lucentensis DSM 14000T, < 97%). CONCLUSION: We found that strains of genus Alcanivorax, Novosphingobium, Tistrella and Thalassospira were predominant bacteria of PAHs-degrading consortia in sea water and surface sediment of Middle Atlantic Ridge deep sea, with Novosphingobium spp. as their main PAHs degraders. PMID- 19873755 TI - [Antifungal sctivities and stability of extracts from culture liquid of Hypoxylon perforatum to Sphaeropsis sapinea]. AB - OBJECTIVE: Our research objective is to obtain the active substances from culture liquid of Hypoxylon perforatum with inhibitory effect on Sphaeropsis sapinea growth and germination. METHODS: Water and ester were used for extracting active substances from culture liquid of Hypoxylon perforatum, either by extracting directly from cultural liquid, or extracting under ultrasonic. Growth-inhibiting rate and germination-inhibiting rate were used as the index of antifungal activity. RESULTS: Five extracts from culture liquid of Hypoxylon perforatum showed antifungal activities to Sphaeropsis sapinea growth and germination. CONCLUSION: Ethyl acetate-extract from culture liquid of Hypoxylon perforatum has a highly antifungal activity to Sphaeropsis sapinea, high stability in the natural environment. So it has a highly development of the value and application prospect. The mainly inhibiting active substance is methyl p-methoxy cinnamate, which as medicine intermediate was used in cosmetic to be UV-protection absorbefacient. Diisobutyl phthalate and Dibutyl phthalate are all the common plastic-enhancer for PolyvinylChloride (PVC). It is very important in medicinal industry and chemistry industry to discovering the natural presence of the three compounds. PMID- 19873756 TI - Isolation and identification of a new radiation-resistant bacterium Deinococcus guangriensis sp.nov. and analysis of its radioresistant character. AB - OBJECTIVE: To isolate and identify a new ionizing-radiation resistant strain capable of surviving under highly ionizing radiation conditions as UV and gamol/La radiation and to characterize its radioresistant properties. METHODS: The isolates were sampled from Radiation Centre of Guangxi University, Nanning, China, and the medium used for isolation and cultivation of the bacterium was General Bacterial Medium (GBM). The new ionizing-radiation resistant strain WGR700(T) was identified by its morphology, biochemical and physiological characteristics, fatty acids, G + C content of DNA, UV and gamol/La radiation resistance and 16S rRNA gene sequence homology. RESULTS: The strain WGR700(T) is of rod-shape, Gram-negative, non-spore-forming, non motile, aerobic and red pigmented. The optimum temperature and pH for strain WGR700(T) growth is 37 degrees C and pH 7.0, respectively. The predominant respiratory quinone is MK-8 and its cell well contains ornithine. The major cellular fatty acids found in the cell wall are 16:1omega7c, 16:0, 15:1omega6c, iso-15:0 and iso-17:0. DNA of strain WGR700(T) had a G + C content of 64.7 mol%. WGR700(T) was highly resistant to UV ( > 728 J/m2 ) and gamol/La radiation ( D10 = 9.8 kGy). Phylogenetic analysis of the 16S rRNA gene sequences showed 87.1-95.6% similarities with other recognized Deinococcus species. CONCLUSION: Based on the high 16S rRNA gene sequence divergence and phenotypic differences, it is proposed that the new isolated strain should be classified as a novel member in the genus Deinococcus with the name Deinococcus guangxiensis sp. nov. The type strain is WGR700(T)( = CGMCC 1.7045T = CICC 10360T = JCM 15082T) . PMID- 19873757 TI - [Characterization of a carbendazim-degrading Trichoderma sp. T2-2 and its application in bioremediation]. AB - OBJECTIVE: To obtain carbendazim-degrading microbial strains, and to use them for bioremediation of contaminated soil. METHODS: A carbendazim-degrading bacterium T2-2 was isolated from the screening of drug-tolerated mutants Trichoderma strains. High-pressure liquid chromatography-mass spectrometry (HPLC-MS) analysis showed the presence of the metabolites after shake incubation of the Trichoderma T2-2 at temperature 25 degrees C, 200 r/min in mineral salt medium that contained 100 mg/ L carbendazim. We prepared T2-2 bioremediation agents from crop straw through solid fermentation. By inoculating T2-2 in soil, we performed a bioremediation test of sterilized soil and original soil at 0.1 mg/g dry soil of carbendazim concentration and 10(7) cfu/g dry soil of inoculating amount. In addition, we also conducted a control effect experiment of T2-2 against fusarium wilt of cucumber. RESULTS: The metabolites detected by HPLC-MS were 2 aminobenzimidazole, benzimidazole, and 2-aminobenxinitrile in the culture filtrate after 2 days of incubation. Carbendazim and metabolites could no longer be detected through the High-pressure liquid chromatography (HPLC) analysis in the culture filtrate after 5 days of incubation. In the soil bioremediation test, carbendazim in the sterilized soil was degraded completely after 6 days of inoculation, whereas the process only needed 4 days in original soil. It showed crop straw could function as co-metabolic substrate and promote co-metabolism of T2-2 and indigenous microorganisms. Moreover, the efficiency of T2-2 against cucumber fusarium wilt might reach 81.7%, which is superior to chemical pesticide. CONCLUSION: T2-2 could degrade carbendazim in soil and thus control plant disease. PMID- 19873758 TI - [Characterization of Listonella anguillarum as the aetiological agent of vibriosis occurred in cultured ayu (Plecoglossus altivelis) in Ninghai country, China]. AB - OBJECTIVE: Ayu (Plecoglossus altivelis) vibriosis threatens ayu aquaculture seriously caused by mass mortality due to severe infections. We characterized the vibriosis pathogen of ayu in Ninghai country. METHODS: A dominant strain was isolated and identified by a series of biochemical and physiological tests. The lethal dose 50% (LD50) was calculated by the modified Karber's method. PCR amplification and sequence analysis were used to further identify the pathogen. RESULTS: LD50 of ayu-H080701 was 1.2 x 10(4) CFU to ayu. PCR amplification showed that the bacterial universal primers for 16S rRNA gene and the specific primers for the metalloprotease (MP) gene of Listonella anguillarum worked. 16S rRNA gene analysis showed that ayu-H080701 shared 99.4%-99.5% nucleotide identical to L. anguillarum isolates, while 94.3% and 91.9% nucleotide identical to L. pelagius and Photobacterium damselae respectively. Metalloprotease analysis showed that ayu- H080701 shared 97.6%-98.8% amino acid sequence identical to L. anguillarum isolates, while lower than 75.6 % to other bacteria. Phylogenetic analysis showed that ayu-H080701 grouped constantly with L. anguillarum isolates. CONCLUSION: The biochemical, physiological tests and sequence analysis all strongly supported the identification of the pathogen causing ayu vibriosis in Ninghai country, China, as an isolate of L. anguillarum. PMID- 19873759 TI - [Suppression of the antigen-specific T cell immune response by co-immunization with the HBV DNA vaccine and recombinant HBsAg]. AB - OBJECTIVE: To explore a new therapeutic strategy against acute hepatitis B and fulminant hepatitis B, we studied effect of co-immunization with HBV DNA and HBsAg on the T cell proliferation reaction. METHODS: We immunized the BALB/ c mice with HBV DNA vaccine (pcDS2) plus HBsAg by intramuscular injection. The immunization was performed on week 0, 2 and 4. The anti-HBs(IgG)antibody titer, T lymphocyte proliferation reaction , and the expression of IL-10 and Foxp3 in CD3 T cell were detected on week 6. RESULTS: The anti-HBs IgG titer induced by pcDS2 plus HBsAg group was higher than that induced by pcDS2, or HBsAg alone. Compared to mice immunized with pcDS2, or HBsAg alone, the stimulated index (SI) of T cell proliferation induced by the pcDS2 plus HBsAg group tested by MTH methods decreased. Besides, the immune suppression of T cell proliferation response induced by co-immunization group was further confirmed by flow cytometry. Finally, the expression of IL-10 and Foxp3 in CD3+ T cell was up-regulated in the co-immunization group significantly. CONCLUSION: The co-immunization of HBV DNA vaccine and HBsAg can induce the humoral immune response, but cannot induce antigen specific T cell proliferation reaction. Besides, the immune suppression induced by co-immunization may be correlated with the expression of IL-10 and Foxp3. PMID- 19873760 TI - [Rescue and identification foot-and-mouth disease virus Asia1/JS/China/2005 strain with Arg-Gly-Asp RGD receptor recognition site]. AB - OBJECTIVE: To construct an infectious full-length cDNA clone of Asial/JS/China/2005 strain with Arg-Gly-Asp (RGD) receptor recognition site. METHODS: We constructed foot-and-mouth disease virus type Asial full-length cDNA clone pFMDV-RGD by using site-directed mutagenesis. The plasmid pFMDV-RGD contained the desired mutation. The plasmids pFMDV-RGD were linearized with NotI enzyme. Linearized plasmid and pcDNAT7P plasmids expressing T7 RNA polymerase cotransfected into BHK-21 cells to rescue FMDV-RGD. RESULTS: We constructed FMDV Asial/JS/China/2005 strain full-length cDNA clone with Arg-Gly-Asp receptor recognition site by sequence. We obtained rescued virus by plasmid cotransfection. The results of sequencing, indirect immunofluorescence, electron microscope and sulk mice pathogenicity analysis showed foot-and-mouth disease virus containing Arg-Gly-Asp receptor recognition site was successfully rescued. CONCLUSION: The results lay a foundation for further study of biology characteristic diversity of rescued virus with Arg-Gly-Asp and Arg-Asp-Asp (RDD) receptor recognition site. PMID- 19873761 TI - [Reverse genetic system for rabies virus vaccine Evelyn-Rokitnicki-Abelseth strain]. AB - OBJECTIVE: To establish a reverse genetic system of rabies virus for producing safe and efficient rabies vaccine. METHOD: By reverse genetic and molecular cloning technique, we established two rabies virus rescue systems including (1) help plasmids expressing N, P and L protein, and (2) CMV/T7 and T7 promoter. RESULTS: Wild-type rERA-VC was rescued by both systems, and had the same growth kinetics as parental virus. The third generation virus could grow to high titer. CONCLUSION: The established reverse genetic system for rescuing wild-type rERA-VC provides the possibility of producing safe and efficient rabies virus vaccines. PMID- 19873762 TI - [Mutations of the hemagglutinin gene of H9N2 subtype avian influenza viruses under selective pressure of antibody]. AB - OBJECTIVE: To understand mutations of avian influenza virus (AIV) under the antibody selective pressures. METHODS: We continuously passed an H9N2-AIV strain LG1 in embryos with or without maternal antibody to LG1 in 6 separate serials. At the 10th, 20th, 30th, 40th and 50th passages in each serial, H9 hemagglutinatin gene (HA) sequences were determined and compared to the original LG1 strain. RESULTS: Only unstable random mutations happened in 29 sites with nonsynonymous vs synonymous (N/S) mutation ratio of 1.42 during 50 passages in 2 serials without maternal antibodies. However, multiple stable nonsynonymous mutations were detected gradually during 50 passages of 4 serials in embryos with maternal antibody to LG1 strain, and the NS/S ratio was as high as 3.46 among 45 mutated sites. CONCLUSION: The results suggested that the antibody selective pressure influenced mutations of H9N2 AIV HA gene during the passages in embryos with maternal antibody. Embryos with maternal antibody to certain viruses could be used as experimental models to study the immune selective pressures on viral mutations. PMID- 19873763 TI - [Transcriptional profiles of intestinal pig epithelial cell jejenum 2 cultures infected by vesicular stomatitis virus]. AB - OBJECTIVE: To better understand the host inflammatory responses, in particular inflammatory cytokines responses of Vesicular Stomatitis virus (VSV) infection, and the host-VSV interaction. METHODS: We used VSV Indian strain to infect the Intestinal Pig Epithelial Cell Jejenum (IPEC-J2) cell. Then we measured and analyzed the viral RNA by using real-time PCR. The transcript level of cytokines (IL-2, 6, 8, 10,12, IFN-alpha, IFN-gamma, TNF-alpha, TGF-beta and TLR3) were detected by real-time PCR. RESULTS: We found that the transcript levels of IL-6, IL-8, IL-12, TNF-alpha and TLR3 were increased obviously whereas TGF-beta showed no significant difference. TPEC-J2 cell did not secrete IL-2, IL-10, IFN-alpha and IFN-gamma. CONCLUSION: The level of inflammatory response was increased when VSV infected TPEC-J2 cell. PMID- 19873764 TI - [Analysis of leader and trailer sequence of genotype III, VIb and VIId Newcastle disease virus determined by modified rapid amplification of cDNA ends (RACE) strategy]. AB - OBJECTIVE: The purpose of this research is to establish a simple rapid amplification of cDNA ends (RACE) strategy for direct mapping of the 3' end and 5' end of the genomic RNA of Newcastle disease virus (NDV), and to analyze the leader and trailer sequence of NDV strains belonging to different genotypes. METHODS: Classic RNA Ligase Mediated Rapid Amplification of cDNA Ends (RLM-RACE) was specifically modified for mapping both ends of the NDV genome. 3'-RACE was carried out by genomic RNA ligation with 5' end phosphated adaptor CL+, and the 5' end was obtained by first strand cDNA with adaptor CL+. RESULTS: A modified RLM-RACE strategy was established in this paper, which proved simple, low-cost, repetitive and could be specifically used to map genome ends of NDV. By using this method, the leader and trailer sequence of 5 NDV strains, termed JS/5/05/Go, JS/07/04/Pi, JS/07/16/Pi, JS/7/05/Ch and JS/9/05/Go, belonging to genotype III, VI and VII was determined, respectively. CONCLUSION: The initial 8nt at the 3' and 5' ends of the genome of genotype I-VI NDV strains were complementary, whereas, the complementary sequences of strain JS/5/05/Go were up to 9 nt due to a mutation from T to C at the 9th nt in the 5' end. The 3' end of NDV genomic and anti-genomic RNA was predicted to form a potential hairpin structure. The U-->C(T ->C) mutation was located in the circle part of the hairpin in the 5' end of anti genomic RNA, and had no visible influence on the formation of RNA secondary structure. However, the sequence of the circle part of the hairpin was changed from 3'-UUUC-5' to 3'-UCUC-5', more similar to the 3'-UCUUA-5' in the hairpin of genomic RNA. PMID- 19873765 TI - [Cloning and analysis of promoter-active fragments from Corynebacterium glutamicum 10147]. AB - OBJECTIVE: To clone promoter-active fragments from Corynebacterium glutamicum for further construction of expression vectors. METHODS: Random Sau3A I digested fragments of C. glutamicum 10147 chromosome were shot-gun cloned into the promoter-probe vector pAKC6 and promoter activity of the inserted fragments was selected by chloramphenicol resistance of transformed C. glutamicum cells. RESULTS: Thirty promoter-carrying fragments were isolated. Three C. glutamicum clones harboring pAKC6 with promoter fragments displayed chloramphenicol acetyltransferase (CAT) activity of more than 24 U/mg. The fragment F57 led to the highest CAT activity of 32.50 U/mg, even more than that produced by the promoter Ptrc, 26.33 U/mg. CONCLUSION: The strength of promoter on fragments F21, F54 and F57 is as strong as promoter Ptrc in C. glutamicum. These fragments can be used to construct expression vector. PMID- 19873766 TI - [Isolation, identification and anticancer activity of an endophytic fungi from Juglans mandshurica]. AB - The endophytic fungus named FSN006 was isolated from the inner bark of Juglans mandshurica. It grew quickly and formed circular colony on PDA plate. The upper side of the colony was white, while the lower side of the colony and the conditioned medium were light yellow as a result of significant yellow pigment substances were produced and secreted by the fungi. Green elliptic conidia appeared when cultured on CMX plate. Based on the morphology identification and ITS sequence, it was clear that this fungus belonged to the Deuteromycotina, HyPhomycetes, Moniliales, Trichoderma longibrachiatum. The conditioned medium of FSN006 showed a high anti-tumor ability against liver cancer cell-HepG2, and reached its IC50 concentration after being diluted 20 times, while the IC50 concentration of curcumine was(11.49 +/- 0.12) mg x L(-1). In addition, there was preeminent selective inhibiting effect against the normal liver cell strain HL 7702 and its caner counter strain HepG2. The inhibiting effect against strain HL 7702 was only one quarter of that against HepG2 at the concentration of IC50. Therefore, the fermentation of FSN006 may provide a possible way to produce anticancer drug with higher efficiency and lower toxicity. PMID- 19873767 TI - [Identification of differentially expressed genes in different anomalies of Glycyrrhiza uralensis by cDNA-AFLP method]. AB - OBJECTIVE: To understand the molecular mechanism in genetic variation within species, and identify the differentially expressed genes among 8 anomalies of Glycyrrhiza uralensis under the same genetic background and cultivated environment. METHOD: The differentially expressed genes in roots of different anomalies of G. uralensis in vigorous growing stage were identified by cDNA-AFLP and confirmed by reverse-Northern hybridization. Their functions were inferred through bioinformatics method. RESULTS: Fourteen differentially expressed genes were identified, among which, the function of 6 were unknown, and the rest were involved in antibacterium, regulating metabolism, enhancing the heat resistance ability, increasing the nitrogen fixation ability, and other bioprocesses. CONCLUSION: For the first time, the differentially expressed genes were cloned from the different anomalies of G. uralensis. This provided the basis for the screening of fine anomalies and varieties, and the research of functional genomics. PMID- 19873768 TI - [Effects of light intensity on growth and photosynthetic characteristics of Chrysanthemum morifolium]. AB - OBJECTIVE: To investigate the effect of light intensity on growth and photosynthetic of Chrysanthemum morifolium. METHOD: The growth characteristics of C. morifolium were measured under different treatments (100%, 80%, 60%, 40% and 20% of full sunlight). The photosynthetic characteristics and chlorophyll fluorescence parameters of leaves under different light intensity were determined by a LI-6400 photosynthesis system and a PAM-2100 chlorophyll fluorescence system. RESULT: With the reduction of irradiance, the diameter of the stem reduced, plant height, leaf length, leaf width and length/width raised, assimilation product increased; Content of photosynthetic pigment increased between light intensity 100%-40% reduced under 20% treatment, chlorophyll a/b decreased. Light compensation point (LCP), apparent quantum yield (AQY) increased first and reduced later, photosynthesis rate (P(n)), stomatal conductance (G(s)), intercellular CO2 concentration (C(i)) and transpiration rate (T(r)) decreased, stomatal limitation value (L(s)) rose. Chlorophyll fluorescence parameters F(v)/F(m) increased, phiPS II, F(v)'/F(m)', ETR and qP increased between irradiance 100%-60%, NPQ decreased, such as phiPS II decreased and NPQ increased when irradiance was lower than 40%. CONCLUSION: Weak light condition was unfavorable to the growth of C. morifolium and the light conditions of culture should be control between 80%-60% of full sunlight. PMID- 19873769 TI - [Accumulation of flavonoids and chlorogenic acid in callus and suspension cell of Eucommia ulmoides]. AB - OBJECTIVE: To analyze and compare the cell growth and accumulation of flavonoids and chlorogenic acid in the callus and suspension cell of Eucommia ulmoides. METHOD: The callus induced from the leaf of E. ulmoides seedlings were suspended in liquid medium. The time courses of cell growth and yields of flavonoids and chlorogenic acid were studied. RESULT: The highest contents of flavonoids and chlorogenic acid in the callus were 13.46, 1.712 mg x g(-1), respectively, while the contents of these two secondary metabolites were 16.63, 3.93 mg x g(-1) in suspension cell culture correspondingly. CONCLUSION: Comparing with callus, the suspension cell showed a short growth period and high growth rate with a remarkable high content of flavonoids and chlorogenic acid. PMID- 19873770 TI - [Isolation and determination of anamorph of Shiraia bambusicola]. AB - OBJECTIVE: To isolate and identify the anamorph of Shiraia bambusicola. METHOD: Fungus strains were isolated from mature ascospores and stroma. They were identified by means of morphological identification including colony and microscope characteristic, the molecular identification was done by 5.8S-ITS rDNA. RESULT: The strains GZDXIFR-171 and GZDXIFR-181 were isolated and obtained with the separation of different methods, which had the same colony morphology. With the universal primers of the ITS1-5.8S rDNA-ITS2, the 5.8S-ITS rDNA sequence of GZDXIFR-171 and GZDXIFR-181 were obtained by the PCR amplification and sequencing. Compared with the published nucleotide sequence of 5.8S-ITS rDNA in NCBI (National Center for Biotechnology Information), GZDXIFR-171 and GZDXIFR-181 were highly identical with S. bambusicola. CONCLUSION: The isolated strains GZDXIFR-171 and GZDXIFR-181 were confirmed to be the true anamorph of S. bambusicola. PMID- 19873771 TI - [Photosynthetic characteristics of Sarcandra glabra]. AB - OBJECTIVE: To learn about the photosynthetic characteristics of Sarcandra glabra and provide the theoretic references for its better planting. METHOD: The photosynthetic parameters of twenty different provenances of Sarcandra glabra were determined by Li-6400 portable photosynthesis system, and the data was analyzed by Excel and SAS software. RESULT: The results showed that the light saturation point of different Provenances of S. glabra were almost about 800 micromol x m(-2) x s(-1), while the light compensation point of them were from 14.70 micromol x m(-2) x s(-1) to 48.68 micromol x m(-2) x s(-1). The curve of net photosynthetic rate had two peaks on sunny day, the first one was in the morning and the other one was in the afternoon. The photosynthetic "noon- break" of S. glabra appeared between 11:00-13:00, when the net photosynthetic rate goes down sharply. Intercellular CO2 concentration (C(i)), CO2 concentration (CO2S) and transpiration rate (T(r)) all have effect on the diurnal change of net photosynthetic rate (P(n)) of S. glabra, and the average correlation coefficient between P(n) and the parameters above were orderly as -0.89 (P < 0.01), -0.75 (P < 0.05) and 0.69 (P < 0.05); CONCLUSION: S. glabra was a plant with characteristics of shade-tolerance, and through the way of covering, sprinkling for decreasing the surrounding temperature would be effective to reduce its "noon break" time and increas its efficiency of photosynthesis. PMID- 19873772 TI - [Solubility peak and dielectric requirement of Buyang Huanwu docoction]. AB - OBJECTIVE: To study the solubility peak and dielectric requirement of the Buyang Huanwu docoction materials, and provide theoretical and experimental foundation for selecting extraction solvent for extracting traditional Chinese drugs (TCD). METHOD: 11 types of solvents were employed as single or complex solvent systems, whose solubility parameter and dielectric constant were from 14.11 to 47.86, dielectric requirement from 1 to 80 respectively, to lixiviate Buyang Huanwu decoction (5 g per samples) in nearly saturate volume as V0 for materials at 25 degrees C. The apparent solubilities of extracts were determined and calculated out according to the section of determination of extract in the appendix of 'Chinese Pharmacopoeia'. RESULT: The saturate solvent V0 for materials powder were 0.21, 0.31, 0.49, 0.36, 0.77, 0.93, 0.86, 0.92, 1.08, 1.00, 1.14 mL x g(-1), respectively. The apparent solubility of Buyang Huanwu docoction for each solvent system were 114.0, 101.3, 73.40, 109.4, 210.7, 295.0, 501.4, 437.0, 355.6, 423.1, 210.6 g x mL(-1), respectively, among which the max apparent solubility, illustrated as solubility peak, was carried out by methanol-water (68: 32) with 47.5 corresponding to the Buyang Huanwu docoction dielectric requirement. CONCLUSION: The apparent solubilities of (TCD) and their formula are controlled by dielectric constant of extraction solvent, and are in accordance with stable dielectric requirement. PMID- 19873773 TI - [Preparation and in vitro release of Maiyanning sustained-release patches]. AB - OBJECTIVE: To prepare Maiyanning sustained-release patches and optimize the prescription. METHOD: The mono-factor design was used to screen the formulation of the sustained-release patches. RESULT: The optimal composition of the formulation was MD-607 as the pressure sensitive adhesive and azone as the penetration enhancer with the content of 5.0%. Drugs released from the pressure sensitive adhesive patches in a constant speed, it confirmed that the drug was released by zero order equation from the patches. CONCLUSION: The prepared patches have an ideal release trait. PMID- 19873774 TI - [Processing technics of Rhizoma Dioscoreae stired by wheat bran]. AB - OBJECTIVE: To study the processing technics of prepared slice of Rhizoma Dioscoreae for its industrial production. METHOD: The effect factors, such as stiring temperature (60, 80, 100 degrees C), stiring time (10, 20, 30 min) and the proportion of pieces and wheat bran (100: 5, 100: 10, 100: 15) were evaluated by orthogonal method. The content of allantoin in Rhizoma Dioscoreae was determine by HPLC method. RESULT: The amount of wheat bran could affect the content of allation significantly, and stiring temperature and stiring time almost had no effect on content of allantoin. The processing technics was tested by industrial produce, according to 11 batches from 4 growing regions. The result showed that the quality of industrial product was stable. CONCLUSION: That the amount of wheat bran can affect the quality of Rhizoma Dioscoreae greatly. The determined technics is simple and suitable for prepared slice of Rhizoma Dioscoreae industrival manufacture. PMID- 19873775 TI - [Effect of several penetration enhancers on transdermal absorption in vitro of syringin, chologenic acid and rutin in Xuelian cataplasm]. AB - OBJECTIVE: To study the effects of different penetration enhancers on the transcutaneous permeability of syringin, chologenic acid and rutin in Xuelian cataplasm in vitro and to determine the effective enhancer. METHOD: Using improved Franz-type diffusion cell and excised big mouse skin in vitro as transdermal barrier, the kinetics parameters of syringin, chologenic acid and rutin in Xuelian cataplasm such as cumulative permeation quantity, permeation rate were determined by HPLC. The enhancement ability of azone (A-zone), propylene glycol (PG) was investigated when used either uniquely or combinatively. RESULT: With the 7% azone, the syringin, chologenic acid and rutin in Xuelian cataplasm could penetrate through the skin of rats well. CONCLUSION: The selection of the best penetration enhancers provide reference for Xuelian cataplasm. PMID- 19873776 TI - [Pre-treatment in determining total polysaccharide in flos Chrysanthemum indicum by response surface design]. AB - OBJECTIVE: To study pre-treatment in determining total polysaccharide in flos Chrysanthemi Indici. METHOD: The factors including the extraction temperature, extraction time, ratio of material to liquid were studied. The best extraction condition was found through the response surface design. RESULT: The best extraction condition as follows: 81.0 degrees C of the extraction temperature, 1.6 h of extraction time, and the ratio of material to water as 1: 29. On these conditions the extraction rate of flos Chrysanthemi Indici was the best. CONCLUSION: A model equation that can be used to predict the experiment is established through the response surface method. PMID- 19873777 TI - [Identification and comparison of constituents in HPLC fingerprint of five Chinese herbal pieces from Rheum palamatum]. AB - OBJECTIVE: To identificate and compare constituents in the HPLC fingerprint of five Chinese herbal pieces from Radix et Rhizoma Rhei. METHOD: HPLC analysis was carried out with methyl alcohol 1% glacial acetic acid as gradient elution, changes in five Chinese herbal pieces and medicinal material under 280 nm and 430 nm were compared. RESULT: HPLC fingerprints of the no-parched pieces, the liquor and the vinegar roasts pieces were similar, 24 peaks were identified under 280 nm 19 or 22 peaks could be indicated in the braising with liquor and the charring respectively. Under 430 nm, 8 peaks were identified except the braising with liquor. CONCLUSION: HPLC fingerprints of the no-parched pieces, the liquor and the vinegar roasts pieces are similar while the changes on chemical composition and the content in braising with liquor and the charring are remarkable. PMID- 19873778 TI - [Chemical constituents from roots of Incarvillea mairei]. AB - OBJECTIVE: To study the chemical constituents of the roots of Incarvillea mairei. METHOD: The chemical constituents were isolated and purified by chromatographic techniques with silica gel, Sephadex LH-20 column, and preparative TLC. Structures of the compounds were identified by spectroscopic methods. RESULT: Seven compounds were obtained and elucidated as 1-O-methyl-guaiacylglycerol (1), 1-O-feruloyl-3-O-(26"-hydroxylhexacosoyl) glycerol (2), incarvine D (3), piceid (4), 6'-8"E, 11"E-octadecadienoyl-clionasterol-3-glucoside (5), beta-sitosterol (6), and beta-daucosterol (7). CONCLUSION: Compounds 1-7 were isolated from I. mairei, and among them 1 and 2 were new compounds, 4, 5 were isolated from the genus Incarvillea for the first time. PMID- 19873779 TI - [Chalcones from Bauhinia glauca subsp. pernervosa]. AB - OBJECTIVE: To study the chemical constituents of Bauhinia glauca subsp. pernervosa. METHOD: The coulis of B. glauca subsp. pernervosa were extracted with 95% EtOH at room temperature. The compounds were isolated and separated by chromatographic techniques, and structures were identified by spectroscopic methods. RESULT: Seven chalcones were isolated and identified: butein-4-methyl ether (1), isoliquiritigenin (2), butein (3), isoliquiritigenin-2'-methyl ether (4), 2',4'-dihydroxychalcone (5), isoliquiritigenin-4-methyl ether (6), 4-hydroxy 2',4'-dimethoxychalcone (7). CONCLUSION: Compounds 1, 3, and 7 were isolated from the genus Bauhinia for the first time, the other compounds were obtained from this plant for the first time. PMID- 19873780 TI - [Chemical constituents from tubers of Dioscorea bulbifera]. AB - OBJECTIVE: To study the chemical constituents in the tubers of Dioscorea bulbifera. METHOD: Compounds were isolated and purified with silica gel, ODS and Sephadex LH-20 column chromatography, their structures were determined by using spectroscopic methods including MS and NMR. RESULT: Fourteen compounds were isolated and identified as stigmasterol (1), mono-arachidin (2), 1,7-bis-(4 hydroxyphenyl)-1E,4E,6E-heptatrien-3-one (3), behenic acid (4), demethyl batatasin IV (5), 2,3'-di-hydroxy-4',5'-dimethoxybibenzyl (6), diosbulbin B (7), diosbulbin D (8), docosyl ferulate (9), 7-bis-(4-hydroxyphenyl) -4E, 6E-heptadien 3-one (10), 5,3,4-trihydroxy-3,7-dimethoxyflavone (11), tristin(12), protocatechuic acid (13), adenosine (14). CONCLUSION: Compounds 24, 6, 9, 10, 12, 14 were isolated from the genus Dioscorea for the first time. PMID- 19873781 TI - [Alkaloids from Macleaya cordata]. AB - OBJECTIVE: To study the alkaloids of Macleaya cordata. METHOD: The alkaloids were isolated and purified by various column chromatography as well as recrystallization. Their structures were identified by physico-chemical properties and spectral analysis. RESULT: Thirteen alkaloids were isolated and identified as 6-methoxy-dihydrosanguinarine (1), norsanguinarine (2), 6-acetonyl dihyrochelerythrine (3), 6-acetonyl-dihyrosanguinnarine (4), sanguidimerine (5), chelidimerine (6), (+/-) -bocconarborine A (7), (+/-)-bocconarborine B (8), cryptopine (9), dihydrosanguinarine (10), dihydrochelerythrine (11), protopine (12), alpha-allocryptopine (13). CONCLUSION: Compounds 2, 3, 5 - 9 were firstly isolated from the genus Macleaya and compound 1 was obtained from M. cordata for the first time. PMID- 19873782 TI - [Chemical constituents from Xanthium mongolicum]. AB - OBJECTIVE: To study the chemical constituents of Xanthium mongolicum. METHOD: The compounds were isolated with column chromatography. The structures were determined by spectroscopic techniques. RESULT: Eight compounds were isolated from X. mongolicum, four compounds are sesquiterpene lactones, two compounds are triterpenes and two compounds are lignins. Their structure elucidated as xanthatin (1), xanthinosin (2), 11alpha, 13-dihydroxanthatin (3), atractylenolide III (4), oleanolic acid (5), ursolic acid (6), lignocellulose (7), balanophonin (8). CONCLUSION: Compounds 3-8 were isolated from this plant for the first time. Sesquiterpene lactones (1-3) had shown the induction hindrance activeness of the (ICAM-1), but the activitiy of 3 was weaker. PMID- 19873783 TI - [Chemical constituents in herbs of Polygonum jucundum]. AB - OBJECTIVE: To investigate the chemical constituents in herbs of Polygonum jucundum. METHOD: The 85% ethanol extract was separated by means of silica gel and Sephadex LH-20 column chromatography. The compounds isolated from the plant were identified by physicochemical properties and spectroscopic evidence. RESULT: Eight compounds were isolated and identified as: quercetin-3'-O-beta-D galactoside (1), 8-methoxyquercetin (2), pigenin (3), luteolin (4), quercetin (5), 3,5,7-trihydroxychromone (6), p-hydroxybenzaldehyde (7), beta-sitosterol (8). CONCLUSION: All compounds were isolated from this plant for the first time, compounds 5- 8 were isolated from the genus Polygonum for the first time. PMID- 19873784 TI - [Determination of d-borneol in the different parts of Cinnamomum camphora by GC MS]. AB - OBJECTIVE: To measure and compare the content of d-borneol in the different parts of Cinnamomum camphora by GC-MS. METHOD: With water-steam distillation and GC-MS method, d-borneol was extracted and determined. RESULT: The linear range of d borneol was 0.4-2.8 microg (r = 0.999 9). The average recovery was 95.40%, and RSD was 0.56%. CONCLUSION: The method is simple and accurate with good separation. The content of d-borneol in the dried leaves 63.97% in the crude exfract. It can provide the proof of the exploitation of C. camphora. PMID- 19873785 TI - [DPPH radical scavenging activities of 31 flavonoids and phenolic acids and 10 extracts of Chinese materia medica]. AB - OBJECTIVE: To investigate DPPH radical scavenging activities of 31 flavonoids and phenolic acids and 10 extracts of Chinese materia medica. METHOD: The antioxidant activities of the above samples were evaluated by a DPPH method, the half-wave oxidation potentials (E1/2) of the 31 compounds were determined by an HPLC CoulArray method, at the same time, phenolic contents of the the total compounds in the 10 extracts of Chinese materia medica were analyzed by Folin-Ciocalteu method. RESULT: The 31 compounds showed a 50% inhibition of DPPH radical in the concentration range of 6.7-3 500 micromol x L(-1), in which (-) -EGCg demonstrated the strongest activity with the IC50 value of 6.7 micromol x L(-1). The E1/2 of 31 compounds spanned a wide potential range of more than 0.6 V. Myricetin had the lowest E1/2 value (20 mV) whereas apigenin and vitexin-2"-O rhamnoside had the highest E1/2 value (620 mV). Among the 10 herb extracts, having 82% phenolic acid, tea extract showed the strongest DPPH radical scavenging activity with the IC50 value of 0.011 7 mg x mL(-1) whereas safflower demonstrated the weakest DPPH radical scavenging activity with the IC50 value of 1.250 mg x mL(-1), in which only 7% phenolic acids was tested. CONCLUSION: The DPPH radical scavenging activities of the 31 compounds were founded to be related to their chemical structures, such as the number and position of hydroxyl groups. And a qualitative relationship was found between DPPH radical scavenging activities and E1/2 values of the 31 compounds, the lower the E1/2 values, the higher the DPPH radical scavenging activities. A quantitative relationship was obtained to describe the DPPH radical scavenging activity of the herb extracts: Y = 7.779X(-0.48), r = 0.929 5, where Y stands for the concentration for 50% inhibition of DPPH radical, and X stands for the concentration of total phenolic compaunds, namely the extracts with higher content of flavonoids and phenolic acid exhibited the stronger DPPH radical scavenging activity. PMID- 19873786 TI - [Protective effects and machanism of muskone on pheochromocytoma cell injure induced by glutamate]. AB - OBJECTIVE: To explore the mechanism of glutamate (Glu)-induced PC12 cell apoptosis and the protective effect of muscone. METHOD: PC12 cells were randomly divided into six groups: normal group (Normal), model group injured by glutamate (Glu), nimodipine group (Nim) and muskone groups (Mus) of high, middle and low doses. The PC12 cells were pretreated with or without different concentrations of muskone for 30 min and then exposed to glutamate. MTT assay for cell survival, flow cytometric detection of apoptotic cells, DCF assay for reactive oxygen species (ROS) and flow cytometric assay was performed to determine the mitochondrial membrane potential in PC12 cell. RESULT: PC12 cell damage, the concentrations of [Ca2+], and apoptosis induced by Glu were decreased after being administrated with paeoniflorin. CONCLUSION: Muskone inhibited Glu-induced apoptosis in PC12 cells. The mechanism is related to inhibiting intracellular Ca2+ overload and maintaining mitochondral membrance potential. PMID- 19873787 TI - [Interaction between four herb compounds and a western drug by CYP3A4 enzyme metabolism in vitro]. AB - OBJECTIVE: To explore the interaction between herbal medicines and western drugs based on CYP3A4 enzyme metabolism by using testotesrone as a probe in liver microsome metabolism system in vitro. METHOD: The mixed liver microsome enzymatic system consisting of rat liver microsomes by ultra-high-speed centrifuge was established. The substrate testosterone was added into the system and enzyme CYP3A4 metabolic activity was expressed by the output of 6beta-hydroxy testosterone which was measured by HPLC method. The proper conditions for testotesrone metabolism in liver microsome system included substrate concentration, incubation time, pH and incubation temperature. When the conditions in vitro were determined, three kinds of Chinese herbal medicinal ingredients (Tetrahydropalmatine, neferine, panax notoginseng saponins) were diluted into different concentrations and incubated with testotesrone in the liver microsomes incubation system, respectively. The results were measured through metabolite production with or without the presence of Chinese medicines. We assessed the Chinese herbal medicinal ingredients effect on the metabolism of CYP3A4 enzyme through 6beta-hydroxy metabolite of testosterone production. RESULT: Liver microsomes were incubated in the system, the testosterone metabolited into 6beta-hydroxy testosterone. The metabolism conditions were proper at the concentration of testosterone 200 micromol x L(-1) which was incubated for 3.5 hours at 37 degrees C in pH 7.0, PBS 0.1 mol x L(-1). The inhibition of tetrahydropalmatine and panax notoginseng saponins on testotesrone were weak with IC50 > 100 micromol x L(-1). The neferine had a little inhibition on testotesrone metabolism, IC50 < 100 micromol L(-1). CONCLUSION: Tetrahydropalmatine and panax notoginseng saponins had no obvious effect on testotesrone metabolism. Neferine had a little effect on testotesrone metabolism. It prompted that drug-interaction could not be apparent between two kinds of Chinese medicines and the CYP3A4 enzyme substrate, Neferine could bring about drug-interaction. PMID- 19873788 TI - [Effects of naringin on proliferation, differentiation and matrix mineralization of MC3T3-E1 cells]. AB - OBJECTIVE: To investigate the effect of naringin on the proliferation, differentiation and matrix mineralization of MC3T3-E1 cells in vitro. METHOD: MC3T3-E1 cell lines were taken in vitro model. CCk-8 method was used to observe the proliferation of MC3T3 cells. Lactic acid dehydrogenase cytotoxicity (LDH) test was used to observe the cell toxicity. Bone morphogenetic protein-2 (BMP-2), alkaline phosphatase (ALP) and osteocalcin (OC) were used to observe the cell differentiation. Von kossa calcification staining method was used to observe the cell calcification. RESULTS: The high dosages of the naringin could promote the proliferation of MC3T3-E1 cells at both 12 h and 24 h. While, low dosages did not show the same capability. LDH test showed that the cytotoxicity percentages in all six naringin treated groups were quite low. BMP-2 cytoimmunochemistry test showed that the three naringin treated group (10, 1, 0.1 micromol x L(-1)) showed higher brown coloration in cytoplasm than the control group at both 24 h and 48 h. 1, 0.1 micromol x L(-1) naringin raised ALP activity of MC3T3-E1 cells at 48 h (P < 0.05). Meanwhile, 0.1 micromol x L(-1) naringin increased the ALP activity at 72 h (P < 0.05). 10 and 1 micromol x L(-1) naringin increased the capability of MC3T3-E1 cell to synthesize osteocalcin during 8th - 12th dsince adding the medicine (P < 0.05). Naringin did not show the positive effects on cell calcification. CONCLUSIONS: Naringin could promote proliferation and differentiation of MC3T3-E1 cells. PMID- 19873789 TI - [HPLC determination of catalpol in cerebrospinal fluid of rats]. AB - OBJECTIVE: To establish an HPLC method for determination of catalpol in CSF (cerebrospinal fluid) of rats. METHOD: Rats were intravenously injected 1.0 g x L(-1) catalpol physiological saline, and the sample of CSF from subarachnoid space of the cerebrum 40 minutes of injection. The sample of CSF from normal rats was used for blank control, the all samples were preserved in a refrigerator of - 20 degrees C, and use HPLC was employed to determine the catalpol content. The separation of catalpol was performed on Hypersil C18 reversion phase chromatographic column. The mobile phase consisted of water-acetonitrile (99.5: 0.5) with a flow rate of 1.0 mL x min(-1) and detection wavelength of 210 nm. RESULT: The linear range of catalpol in CSF was 0.5-40 mg x L(-1) (r = 0.999 7). The absolute recoveries were (90.2 +/- 1.71)%, (89.1 +/- 1.17)% and (86.9 +/- 0.98)%; and the methodological recoveries were (99.8 +/- 1.98)%, (101.1 +/- 3.04)%, (100.1 +/- 2.30)% respectively. The within-day and between-day derivation RSD were less than 4%. Catalpol was stable in a refrigerator of -20 degrees C for 15 days. CONCLUSION: The method is simple and accurate for the determination of the content of catalpol in CSF. PMID- 19873790 TI - [Influence of glycyrrhizin on paeoniflorin pharmacokinetic fate in unrestrained conscious rats by intravenous administration]. AB - OBJECTIVE: The aim of this study is to develop a simple and rapid HPLC method and investigate the effect of glycyrrhizin on pharmacokinetic fate of paeoniflorin after intravenous administration. METHOD: Paeoniflorin and glycyrrhizin was administrated to rat via vena caudalis, and paeoniflorin in rat plasm was determined by RP HPLC method and internal standard method. All data were subsequently processed by the pharmacokinetic Software WinNonLin. The non compartmental pharmacokinetic parameters of area under the plasma concentration time curve (AUC/min x mg x L(-1)), clearance (CL/mL x min(-1) x kg(-1) ) and volume of distribution (Vd/mL x kg(-1)) were calculated based on moment methods. RESULT: The values of AUC, V(d) and CL was 166.81 +/- 26.94, 394.33 +/- 29.52, 18.40 +/- 3.12 in control group, respectively; however, the values of AUC, V(d), CL was 235.44 +/- 46.48, 266.63 +/- 48.43 and 13.16 +/- 2.59 in experimental group. CONCLUSION: Glycyrrhizin significantly influenced the pharmacokinetic fate of paeoniflorin, increasing the value of AUC and decreasing CL and V(d). PMID- 19873792 TI - [Establish remote of sensing monitoring method and standard on wild rare medical plant]. AB - At present the shortage of the resources of wild and rare medicinal plants is very serious in China. So grasping the situation and change tendency of medicinal plant resources comprehensive and real-timely, is vital significance to realize the sustainable using of medicinal plant resources. In order to use the remote sensing monitor technology and method to study the resources of the wild and rare medicinal plants, this article discusses the principle, method, technology and the principle and standard based on the operation and experiment of remote sensing monitor on the resources of wild rare medicinal plant. PMID- 19873791 TI - [Retrospective study of adverse events of Polygonum multiflorum and risk control]. AB - To provide a reference for rational clinical medication and review the irrational use and factors relating the adverse events of Polygonum multiflorum. The literatures on P. multiflorum published between 1978 and 2008 were reviewed and the reports on clinical use were analyzed. A total of 26 literatures were retrieved. 38 cases of adverse drug event were reported, 10 cases of allergy, 24 cases of liver damage, and 4 cases presented with other adverse events. Irrational use is common in both self-medication and doctor prescription. It is one of the main factors of adverse events. Improving clinical rational use is the most important way to control its risk. PMID- 19873793 TI - It's a jab or your job. PMID- 19873794 TI - Medical professionalism in the 21st century. PMID- 19873795 TI - John R. White, MD, KMA President 2009-2010. PMID- 19873796 TI - The surgical management of breast cancer. AB - The management of the patient with breast cancer has evolved to become a multidisciplinary practice. The role of the surgeon remains important in the diagnosis, staging, and treatment of disease, as well as in educating the patient as to her best options. Herein we review current surgical techniques in the diagnosis, resection, and staging of breast cancer including biopsy techniques, surgical approaches to resection of breast cancer, and breast reconstruction, and issues surrounding axillary staging by sentinel lymph node biopsy. PMID- 19873797 TI - Breast imaging screening status and updates. PMID- 19873798 TI - Systemic therapy for early breast cancer. PMID- 19873799 TI - Radiation in the management of breast cancer. PMID- 19873800 TI - The power of "yes". PMID- 19873801 TI - Kentucky pink link: an untapped resource for Kentucky breast cancer patients. PMID- 19873802 TI - A healthier way to pay doctors. PMID- 19873803 TI - Health-care grudge match! PMID- 19873804 TI - What you don't know might kill you. PMID- 19873805 TI - [Introduction]. PMID- 19873806 TI - [The early years]]. PMID- 19873807 TI - [Theological philosophical principles]. PMID- 19873808 TI - [Quadratur manuscripts]. PMID- 19873809 TI - [Summary]. PMID- 19873810 TI - Diabetes support at school: starting a group. PMID- 19873811 TI - Fast-food cooking at home. Drive-in menu. PMID- 19873812 TI - Disaster preparedness. It's never too early to plan ahead! PMID- 19873813 TI - Diabetes quiz. How much do you know about depression? PMID- 19873814 TI - Fish and shellfish. PMID- 19873815 TI - What your doctor is reading. PMID- 19873816 TI - Being supermarket savvy. PMID- 19873817 TI - Common foot problems and their solutions. PMID- 19873818 TI - Food for thought. The best of the harvest. Squash is a sweet seasonal treat. PMID- 19873819 TI - Diabetes 101. Gastroparesis. Feeling full. This nerve disorder can leave your stomach out of sync. PMID- 19873820 TI - Diabetes at 100 mph. Catching up with Charlie Kimball, a race car driver with type 1. PMID- 19873821 TI - 10 ways to save a buck and improve your health. PMID- 19873822 TI - More questions than answers. What you've heard about antioxidants may be mostly hype. PMID- 19873823 TI - Top it off. PMID- 19873824 TI - Cracking the case. A federal jury finds diabetes discrimination at the FBI. PMID- 19873825 TI - The big D. Looking for links between type 2 diabetes and vitamin D. PMID- 19873826 TI - Failing trust put inpatients at risk. PMID- 19873827 TI - Taking a look at ordinary people's tales of life with mental illness. Interview by Alita Howe. PMID- 19873828 TI - Tumors in brown bullheads in the Chesapeake Bay watershed: analysis of survey data from 1992 through 2006. AB - Liver and skin tumor prevalences in brown bullheads Ameiurus nebulosus have been used in the North American Great Lakes to designate highly contaminated areas of concern and monitor their recovery. Here we interpret the results of six surveys conducted in the Chesapeake Bay watershed between 1992 and 2006, with data for 647 fish. The objective has been to develop an adequate database to critically evaluate the use of tumor prevalence as a habitat quality indicator within the watershed. Surveys featured randomized fish collection; recording of sex, length, weight, and age; and histopathology of all livers and all raised skin lesions. The Bayes information criterion was used to analyze all possible combinations of age, gender, length, and weight as covariates for logistic regression. Length and gender were the covariates that best described liver tumor prevalence. There were no covariates in the model for skin tumor prevalence. In some surveys, biomarkers, such as biliary polynuclear aromatic hydrocarbon (PAH)-like metabolites, hepatic cytochrome P450 activity, and hepatic DNA adducts, were used with sediment and tissue chemistry data to evaluate classes of chemicals as likely contributors to tumor prevalence. We highlight two surveys of the Anacostia River, Washington, D.C. (average = 55% liver tumors, 23% skin tumors), where sediment PAHs, biliary PAH-like metabolites, and hepatic DNA adducts were high, suggesting that PAHs play a major role. We show that logistic regression is an appropriate procedure for comparing "contaminated" versus "reference" locations, and we evaluate the utility of tumor surveys as an environmental indicator for the Chesapeake Bay watershed. PMID- 19873829 TI - Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei. AB - The virulence of seven geographic isolates of white spot syndrome virus (WSSV; genus Whispovirus; China [strain CH1995], Nicaragua [strain N2000], Honduras [strain H2000], Ecuador [strains E-L1999 and E-LT2002], and Mexico [strains M M2001 and M-LP2001]) was compared using a series of challenge experiments, each lasting 10 d. For each isolate, four quantified dilutions (10(-6), 10(7), 10(-8), and 10(-9)) of a viral inoculum were prepared from WSSV-infected shrimp tissue. Each viral inoculum was injected into 10 specific pathogen-free juvenile Pacific white shrimp Litopenaeus vannamei (0.25-1.50 g); controls received injections of marine crustacean physiological saline (3.2%). The minimum dose of viral inoculum that killed 50% of injected shrimp (LD50) was calculated for dilution, tissue concentration, and viral DNA amount. The CH1995 and M-M2001 isolates were the least virulent, with LD50 values of 10(-6) to 10(-7) of viral inoculum. The isolates could be grouped into three virulence clusters (CH1995 and M-M2001; N2000 and E-LT2002; and H2000, E-L1999, and M-LP2001). Virulence clusters were not altered by LD50 values based on viral DNA concentration, although a slight shifting of order in regards to virulence was seen among the three most virulent isolates (E-L1999, H2000, and M-LP2001). Overall, results indicate that there is a measurable virulence difference among WSSV isolates, which may correspond to geographical region. PMID- 19873830 TI - Optimizing copper sulfate treatments for fungus control on channel catfish eggs. AB - This range-finding study determined the optimum concentration of copper sulfate (CuSO4) for fungus control on eggs of channel catfish Ictalurus punctatus. The study consisted of five CuSO4 concentrations (2.5, 5, 10, 20, and 40 mg/L) and an untreated control in a flow-through system. A single spawn was used for each replication (N=4). Eggs were treated daily until the embryos reached the eyed stage. When hatching was complete for all viable eggs, fry were counted to determine the percent survival in each treatment. Fungal growth was severe in the untreated controls; survival of hatched fry in the control group was approximately 2%. The optimum CuSO4 treatment, as determined by percent survival of hatched fry, was 10 mg/L daily (69% survival); survival for this treatment group was significantly different from that for the controls. Very little fungus was present in treatments receiving 10-mg/L CuSO4 or higher except in one replication that had approximately 40% unfertilized eggs. The average survival rates in the 0-, 2.5-, 5-, 10-, 20-, and 40-mg/L CuSO4 treatments were 2, 34, 50, 69, 59, and 51%, respectively. PMID- 19873831 TI - Are all koi ulcer cases associated with infection by atypical Aeromonas salmonicida? Polymerase chain reaction assays of koi carp skin swabs submitted by hobbyists. AB - Infection by atypical Aeromonas salmonicida is regarded as the cause of ulcer disease (KUD) in koi carp Cyprinus carpio and goldfish Carassius auratus. However, other causes--including parasites, viral infection, and fungi--have been proposed. In our diagnostic work, we often fail to isolate A. salmonicida even when clear clinical signs of KUD are present. This failure may be because these fastidious and slow-growing bacteria are difficult to isolate in culture or because the bacteria are not actually present in the lesions. In this study, we used polymerase chain reaction (PCR) to detect A. salmonicida in DNA samples swabbed from koi carp ulcers. These alcohol-preserved samples were collected and submitted by hobbyists and included 40 separate cases from 12 different states. We identified atypical A. salmonicida by PCR in 52 of 62 samples submitted and in 33 of 40 unique cases. The negative findings for A. salmonicida by PCR could all be attributed to high water temperatures, prior antibiotic use, poor sample quality, or misdiagnosis of columnaris disease as KUD. Tests for Aphanomyces invadans by PCR were negative in every case. This work confirms that A. salmonicda is still the predominant cause of KUD and that our negative culture results were most likely due to technical failures rather than an absence of A. salmonicda in the ulcer lesions. PMID- 19873833 TI - Evaluation of sodium carbonate peroxyhydrate as a potential catfish egg disinfectant. AB - Two experiments were conducted to evaluate the efficacy of sodium carbonate peroxyhydrate (SCP) in improving the hatching success of channel catfish Ictalurus punctatus when used as a prophylactic chemotherapeutant during egg incubation. In the first experiment, the efficacy of SCP was evaluated in 379-L aluminum incubation troughs similar to those used in commercial hatcheries. Egg masses treated daily with 254 mg of SCP/L of water had significantly higher mean hatching success than untreated controls, and a pathogen-inhibiting effect was also evident (i.e., no gross infection was observed on the treated egg masses). In the second experiment, the hatching success of egg masses treated daily with 254 mg/L was compared with that of egg masses treated daily with hydrogen peroxide (70 mg/L). The effects of both treatments on the pH, dissolved oxygen, and hydrogen peroxide concentrations in the trough were also examined. Both SCP and hydrogen peroxide significantly improved hatching success. Unlike in the treatment with hydrogen peroxide, water pH increased during the treatment with SCP; however, no negative effects on hatching success were observed. The results of this research suggest that SCP acts similarly to hydrogen peroxide in improving channel catfish hatching success and warrants further research to determine whether it could be a practical and effective alternative for managing catfish egg infections in commercial hatcheries. PMID- 19873832 TI - Assessment of cellular and functional biomarkers in bivalves exposed to ecologically relevant abiotic stressors. AB - An understanding of the complex effects of the environment on biomarkers of bivalve health is essential for aquaculturists to successfully select field culture sites and monitor bivalve health in these sites and in hatcheries. We tested several whole-organism (functional) and cellular-level biomarkers as indicators of health of the cultured, stress-tolerant northern quahog (hard clam) Mercenaria mercenaria. We performed single- and dual-stressor experiments that were consistent with available water quality data from a clam culture area on the Gulf coast of Florida. Clams from the culture area were exposed over a 14-d period to low O2 (hypoxia), elevated temperature, hyposalinity, and a combination of elevated temperature and hyposalinity. There was no clear relationship between the functional and cellular-level biomarkers, with most of the treatment effects being detected at the whole-organism level but not the cellular level. Survival and burial ability were significantly affected by elevated temperature and by the combination of elevated temperature and hyposalinity. Glycogen content decreased over the experiment duration and did not differ significantly among treatments. There were no significant changes in expression patterns of eight stress proteins or in the levels of oxidatively damaged RNA. The results highlight the importance of investigating the effects of multiple stressors in short-term, controlled laboratory conditions and suggest that such cellular-level biomarker assays should be paired with functional biomarkers to better understand the responses of highly stress-tolerant species. PMID- 19873834 TI - Identification of Edwardsiella ictaluri and E. tarda by species-specific polymerase chain reaction targeted to the upstream region of the fimbrial gene. AB - Phylogenetic analysis of nine strains of Edwardsiella ictaluri and eight strains of E. tarda (six typical motile strains and two atypical nonmotile strains) isolated from diseased fish was performed using the upstream region of the fimbrial gene cluster. Strains of E. ictaluri and E. tarda were significantly clustered into separate groups. Moreover, atypical E. tarda strains were clustered into a different group from the other strains. Three polymerase chain reaction (PCR) primer sets for differential detection of E. ictaluri as well as typical and atypical E. tarda were developed from the respective characteristic sequences. Strains of E. ictaluri, typical E. tarda, and atypical E. tarda were specifically detected by PCR using each primer set. No amplifications were observed after the use of these three primer sets with 25 other bacterial species, including fish pathogens. In addition, the three primer sets were able to detect the DNA of each target species from fish kidney and liver artificially infected with E. ictaluri or E. tarda. PMID- 19873835 TI - Competing commitments in clinical trials. PMID- 19873836 TI - An approach to evaluating the therapeutic misconception. PMID- 19873837 TI - Factors that influence institutional review board members' commitment to their role responsibilities. PMID- 19873838 TI - Resting easy. Genset provides medical center with peace of mind. PMID- 19873839 TI - The right connections. Cardiovascular facility improves efficiencies. PMID- 19873840 TI - Veterans of innovation. 2009 ES Department of the Year. PMID- 19873841 TI - Sprucing up wayfinding. From traditional signs to electronic kiosks, designers are making it easier to get patients to their destinations. PMID- 19873842 TI - Back to nature. Using natural and recycled materials give hospitals a fresh look. PMID- 19873843 TI - {Open} communication. Implementing a building automation protocol system. PMID- 19873844 TI - Converging interests. The merging of surgery and imaging influences design. PMID- 19873845 TI - [Recommendations for emergency contraception use]. PMID- 19873846 TI - [Frequently asked questions concerning the A/H1N1 virus]. PMID- 19873847 TI - [Evaluation of influenza vaccination in community pharmacies 2008-2009]. PMID- 19873848 TI - [Self-medication of upper gastrointestinal symptoms: a community pharmacy study]. AB - BACKGROUND: Upper gastrointestinal (GI) symptoms are a common reason for self treatment with over-the-counter (OTC) medication. However, data on the typology of GI complaints for which individuals seek self-medication and, more importantly, on the prevalence of alarm symptoms in this population are scarce. OBJECTIVE: This study aimed to investigate: (i) the nature of GI symptoms people intend to self-medicate, (ii) prevalence of alarm symptoms, (iii) compliance with referral advice given by the pharmacist, and (iv) self-reported efficacy and frequency of use of OTC medication for minor complaints. METHODS: This descriptive study was performed in 63 community pharmacies. Participants (n=592, aged 18-80 y) completed a questionnaire to assess symptom characteristics and previous medical consulting. Based on this information, the pharmacist referred subjects to a physician or advised self-treatment. Four weeks later, participants were presented a follow-up questionnaire, evaluating compliance with referral advice or efficacy of self-treatment. RESULTS: The most frequently reported GI complaints were burning retrosternal discomfort (49.2%), acid regurgitation (53.2%) and bothersome postprandial fullness (51.2%). At least 1 alarm symptom was present in 22.4% of the individuals, difficulty in swallowing being the most prevalent one (15.4%). Although twenty-one percent of the customers were referred, only 51.7% of these actually contacted a physician. Almost all of the remaining customers who were advised self-treatment reported symptom relief with the obtained OTC drug (95.1%). CONCLUSIONS: Mild GI symptoms will mostly resolve with self-treatment. Yet, the value of pharmacist counselling on OTC treatment should be recognized, as community pharmacists can play an important role in PMID- 19873849 TI - [The administration of proton-pump inhibitors in little children or patients with difficulties in deglutition]. PMID- 19873850 TI - [Treatment adherence as a social ability: a case of patients with schizophrenia]. AB - Psychosocial rehabilitation programs are available for schizophrenic patients to develop social abilities. Taking into account deficits in drug compliance of such patients, psycho-educational programs have been developed to tackle patients' abilities to take their drugs. One year after discharge from psychiatric facilities however, only 50% of the psychotic patients are still compliant with their drug treatment. The aim of our paper is to describe concepts associated with drug adherence as a social ability, and to illustrate these concepts with a program designed for psychotic patients. First, we define the concept of social rehabilitation, second, we describe strategies available to enhance adherence to drug treatment, third, we present a psycho-educational program developed at St. Egreve Hospital, France. This program is centered on the patient's own capacities to become adherent. Individual in-patient consultations, developed by a team of 3 professionals (psychiatrist, pharmacist, nurse) are linked to indiviual follow-up at home. Their scope is to identify specific targets for the patient's self efficacy to run his drug treatment in an autonomous way. PMID- 19873851 TI - [Antibiotics dispensed upon the recommendation of staff in private dispensaries in Abidjan in the Ivory Coast]. AB - BACKGROUND: The inappropriate dispensing of antibiotics and inadequate antibiotic treatment leads to the emergence of bacterial resistance. The aim of this study is to assess and describe the antibiotics dispensed upon the recommendation of staff in private pharmacies in Abidjan. It is also a matter of determining whether the information given when the drug is dispensed encourages the correct compliance of the antibiotic treatment by the patients. METHODS: Eighteen private pharmacies were in these private pharmacies was recorded using observation handbooks. Focus groups were set up with staff from the private pharmacies with the aim of better understanding of the actions observed. In the study, only antibiotics administered in systemic way were taken into account. RESULTS: One thousand one hundred and twenty-three purchases of antibiotics were observed in total, 158 of which were dispensed upon the recommendation of staff in the private pharmacies (14.1%) [95% CI = 12.1-16.3%]. Penicillin, co-trimoxazole and macrolides constituted the most frequently recommended groups of antibiotics. Compared with the assistants, the pharmacists recommended antibiotics more frequently to customers. The three main groups of symptoms leading to the dispensing of antibiotics upon recommendation were respiratory, gastro-intestinal and cutaneous symptoms. The staff in private pharmacies almost systematically recommended antibiotics for loose coughs lasting more than three days without taking into account the customer's age, general condition and extra-respiratory signs. The duration of the antibiotic treatment was clearly given in 25 cases (15.8%) and information telling customers to take antibiotics at mealtimes was only given on exceptional occasions. It transpired from the meetings conducted with pharmacy staff that there were indirect financial incentives, known as "Unites Gratuites", offered by the medical reps from certain pharmaceutical laboratories, encouraging the excessive dispensing of antibiotics. CONCLUSION: The staff in private pharmacies in Abidjan advise customers to take antibiotics even though they are prescription-only drugs. This leads to the inappropriate dispensing of antibiotics. Some information essential for the correct compliance of the treatment by patients, such as the duration of the treatment and taking it at mealtimes, are often omitted. Educational interventions aimed at pharmacy staff and measures encouraging the application of the law on the sale of antibiotics, are necessary to improve the dispensing of these drugs in private pharmacies in Abidjan. PMID- 19873852 TI - [Etravirine--oral administration (Intelence)]. PMID- 19873853 TI - [Zinc acetate hydrate--oral administration (Wilzin)]. PMID- 19873854 TI - Evidence mounts in favour of QRISK. PMID- 19873855 TI - Non-motor symptoms may herald Parkinson's disease. AB - Parkinson's disease is the second most common neurodegenerative disorder, after Alzheimer's disease. It predominantly affects the elderly. Age is the most clearly established risk factor and there is a male:female ratio of 1.5:1. Current incidence in the general population is 8.4-19 per 100,000 population per year with an approximate prevalence of 120 per 100,000 population. NICE recommends that patients with suspected Parkinson's disease should be referred untreated to a specialist with expertise in parkinsonian disorders. The diagnosis is primarily clinical. Parkinson's disease should be suspected in all patients presenting with bradykinesia (which is essential for the diagnosis of any form of parkinsonism, including Parkinson's disease), muscular rigidity, resting tremor (4-6 Hz) and postural instability not caused by a primary visual, vestibular, cerebellar, or proprioceptive dysfunction. At present, there are no specific biochemical, imaging or genetic tests to assist in the diagnosis of Parkinson's disease. Structural brain imaging (MRI or CT) has no role in the diagnosis of Parkinson's disease but may be useful to exclude cerebrovascular disease, hydrocephalus and Wilson's disease in selected cases. Parkinson's disease is a condition that results in both motor and non-motor symptoms. Morbidity associated with non-motor symptoms in Parkinson's disease is becoming increasingly recognised and some non-motor symptoms such as hyposmia, apathy, depression and REM sleep behaviour disorder may precede the onset of motor symptoms. PMID- 19873856 TI - Diagnosing and managing multiple sclerosis. AB - The most common form of MS is relapsing remitting MS (RRMS). This is now a treatable condition and early diagnosis is becoming increasingly important in order to guide management decisions. After several years, RRMS may evolve into a slowly progressive deterioration in neurological function, known as secondary progressive MS. In 10-15% of people with MS, the condition follows this pattern of slow deterioration from onset, without relapses or remissions. This is primary progressive MS. It is difficult to predict prognosis in an individual patient. Factors associated with a favourable prognosis include female sex, onset with optic neuritis or sensory symptoms (rather than weakness or ataxia) and a long interval between initial relapses. RRMS is most commonly diagnosed in white women in their 20s. The first attack is known as a 'clinically isolated syndrome' reflecting inflammation in a single location. Common sites and symptoms are: optic nerve; spinal cord; sensory symptoms; Lhermitte's symptom and brainstem. The time course of symptoms is often helpful, as it is characteristic of inflammation. Patients tend to deteriorate over days, remain at a nadir for a week or two, and then recover over weeks. Recovery may be incomplete. Question patients directly to find out if there is a past history of any of the other common symptoms and perform a full neurological examination. Primary progressive MS should be suspected in patients presenting with a progressive spastic paraparesis or cerebellar syndrome. The diagnosis of MS should be made by a specialist and patients with a syndrome suggestive of MS should be referred to a neurologist. The mainstays of pharmacological treatment in RRMS are still the beta interferons and glatiramer acetate. These drugs reduce the rate of relapse by about a third and are therefore indicated for mobile patients with at least two relapses in the past two years. PMID- 19873857 TI - Tackling persistent low back pain in primary care. AB - Non-specific low back pain is pain or discomfort felt in the lower back, where there is no cause identified. It may include symptoms referred to the lower limbs. Those patients who develop chronic pain and disability persisting for more than a year are unlikely to resume normal activities. There is no reliable method of identifying structures responsible for non-specific low back pain. X-rays and MRI are considered to be unhelpful in improving treatment success, and are only recommended for those patients for whom surgery is being considered, or where serious pathology needs to be excluded. Patients should be encouraged to stay active, exercise and carry on with their normal activities. The following approach is recommended initially for persistent low back pain: advice and a stepped approach to analgesics with referral to a pain specialist if longer-term, strong opioids are required. In addition, patients should also be offered up to 12 weeks of one of the following: tailored exercises; manual therapy; or acupuncture. A second option should be offered if the first choice does not provide satisfactory improvement. Combined physical and psychological treatment for up to eight weeks is recommended for patients with severe disability and/or significant psychological distress who have had at least one of the above options. PMID- 19873858 TI - Bites and stings. PMID- 19873861 TI - Checklists and patient safety. PMID- 19873862 TI - Managing gestational diabetes mellitus. PMID- 19873863 TI - Cerebral palsy following neonatal hypoxic seizures in singleton term infants: the influence of parity. AB - This was a retrospective review of term singleton neonates (> 37 weeks) with early onset seizures, with and without encephalopathy, from 1989 through 2000. Our aim was to examine the relationship between antepartum and intrapartum obstetric events, neonatal hypoxic seizures and subsequent neurological impairment of 77,838 infants, the incidence of seizures was significantly higher among primiparas (2.4/1000; 67/31,729) compared with multiparas (0.35/1000; 16/46,109)(p < 0.001). Compared with multiparas, seizures with encephalopathy occurred more frequently among primiparas (0.8/1000; 26/31,729) vs. multiparas (0.2/1000; 8/46,109), were more commonly associated with unexplained intrapartum hypoxia (0.6/1000, n = 20 vs.0.04/ 1000, n = 2) and the incidence of cerebral palsy, 45% (9/20) vs. 0% (0/2) was significantly higher(p < 0.001). Seizures with encephalopathy (0.2/1000 vs.0.13/1000) and cerebral palsy (33%) had a similar incidence in primiparas and multiparas following a sentinel event. Neonatal seizures with encephalopathy, related to intrapartum events, were 4 times more common following first delivery and associated with a 9 fold higher incidence of cerebral palsy, implicating primiparous labor in the development of cerebral palsy. PMID- 19873864 TI - Depression, suicidality and alcohol abuse among medical and business students. AB - We determined the prevalence and correlates of depression, alcohol abuse and suicidal ideation among medical and business students in Trinity College, Dublin and University College, Dublin. We rated depression and suicidal ideation in the past month with the Beck Depression Inventory (BDI) and alcohol abuse with the CAGE. Of 539 students registered, 338 (62.7%) responded. 47 (13.9%) students were depressed, scoring > or = 10 on the BDI. 83 (24.6%) students had an alcohol use disorder (CAGE > or = 2). Alcohol abuse was more common among business students than medical students (AOR = 2.9; 95% C.I. = 1.7-5.1); there were no other inter faculty differences. 20 (5.9%) students reported suicidal ideation in the last month. Suicidal ideation correlated positively with stressful life events (AOR = 1.4; 95% C.I.= 1.1-1.7), and negatively with social support (AOR = 0.6; 95/ C.I. =0.5-0.7). These findings suggest that students are a vulnerable group, and underscore the need for mental health education and psychosocial support services in universities. PMID- 19873865 TI - Meeting the health care needs of school-age children with intellectual disability. AB - Intellectual disability (ID) is common and is known to affect 1-3% of the population. There is a lack of medical epidemiological data in Ireland for this group. Such data is necessary in providing the evidence base to plan for rehabilitation services, provide ongoing health care and consider prevention strategies. We report on the underlying diagnosis and co-morbidities of the school-age children in one Health Service Executive area. There were 97 children. Forty seven (48.5%) of the children have a chromosomal or genetic explanation for their disability, 16 (16.5%) have an environmental cause and 34 (35%) have no identified cause. The children have complex medical needs: 35 (36%) have epilepsy and 34 (35%) have gastro-intestinal problems; 24 (25%) have a respiratory condition and 15 (15%) have congenital heart disease. Thirty one (32%) and 30 (31%) have visual and hearing impairment respectively. Expansion of the National Intellectual Disability Database should be explored to include the medical epidemiological data to inform the future development of services for Intellectually Disabled. PMID- 19873866 TI - Age related outcome in acute subdural haematoma following traumatic head injury. AB - Acute subdural haematoma (ASDH) is one of the conditions most strongly associated with severe brain injury. Reports prior to 1980 describe overall mortality rates for acute subdural haematomas (SDH's) ranging from 40% to 90% with poor outcomes observed in all age groups. Recently, improved results have been reported with rapid diagnosis and surgical treatment. The elderly are predisposed to bleeding due to normal cerebral atrophy related to aging, stretching the bridging veins from the dura. Prognosis in ASDH is associated with age, time from injury to treatment, presence of pupillary abnormalities, Glasgow Coma Score (GCS) or motor score on admission, immediate coma or lucid interval, computerized tomography findings (haematoma volume, degree of midline shift, associated intradural lesion, compression of basal cisterns), post-operative intracranial pressure and type of surgery. Advancing age is known to be a determinant of outcome in head injury. We present the results of a retrospective study carried out in Beaumont Hospital, Dublin, Ireland's national neurosurgical centre. The aim of our study was to examine the impact of age on outcome in patients with ASDH following severe head injury. Only cases with acute subdural haematoma requiring surgical evacuation were recruited. Mortality was significantly higher in older patients (50% above 70 years, 25.6% between 40 and 70 years and 26% below 40 years). Overall poor outcome (defined as Glasgow outcome scores 3-5) was also higher in older patients; 74.1% above 70 years, 48% between 40 and 70 years and 30% below 40 years. Poor outcome in traumatic acute subdural haematoma is higher in elderly patients even after surgical intervention. PMID- 19873867 TI - Towards safer use of opioids. AB - The main aim of our work was to improve the safety of opioid use in our institution, an acute generalhospital with 620 beds. Initially, all reported opioid errors from 2001 - 2006 were audited. The findings directed a range of multidisciplinary staff educational inputs to improve opioid prescribing and administration practice, and encourage drug error reporting. 448 drug errors were reported, of which 54 (12%) involved opioids; of these, 43 (79%) involved codeine, morphine or oxycodone. 31 of the errors (57%) were associated with administration, followed by 12 (22%) with dispensing and 11 (20%) with prescribing. There were 2 reports of definite patient harm. A subsequent audit examined a 17-month period following the introduction of the above teaching: 17 errors were noted, of which 14 (83%) involved codeine, morphine or oxycodone. Again, drug administration was most error-prone, comprising 11 (65%) of reports. However, just 2 (12%) of the reported errors now involved prescribing, which was a reduction. PMID- 19873868 TI - Congenital diaphragmatic hernia: neonatal outcomes following referral to a paediatric surgical centre. AB - Congenital diaphragmatic hernia (CDH) is a rare malformation observed in approximately 1 in 3000 live births. Estimates of postnatal survival range from 50 to 70% despite advances in neonatal care. Antenatal diagnosis is associated with termination of pregnancy in 25-50% pregnancy internationally which may not be reflective of the Irish population. We aimed to evaluate the mortality of infants with CDH who survived to admission in a tertiary referral paediatric hospital between 1996 and 2007. The Hospital In-Patient Enquiry system was used to determine the number of neonatal referrals for CDH to OLHSC between 1996 and 2007. Mortality, sex distribution, length of patient stay and the number of cases per year were examined. 141 neonates with CDH were over 12 years with approximately 12 referrals per annum of which 82 (58%) were male and 59 (42%) female. The average length of stay in the hospital was 33 (range 0-364) days. Overall 71% of the patients survived to discharge. In the first epoch (1996-2001) survival was 63% compared with 78% in the later epoch (2002-7). The overall survival for neonates with CDH presenting to OLCHC during the 12 year-period was 71% although this improved to 78% in recent epoch. Further study of associated congenital anomalies, number of terminations of pregnancy, complexity of the diaphragmatic defect and degree of pulmonary hypertension are required to compare this population with other international centres. PMID- 19873869 TI - Causes of prolonged hospital stay following low-energy fracture of the proximal femur: issues of most concern. AB - Hip fractures are an important cause of morbidity in the elderly and represent a significant proportion of acute orthopaedic admissions. We reviewed a consecutive series of hip fractures presenting to our unit over five years, obtaining demographic and clinical data from patient's medical records. Patients who remained in-patient for greater than fourteen days were analyzed for reasons responsible. We reviewed 717 consecutive hip fractures. The average length of stay was 28 days. Forty-nine percent of patients stayed in hospital greater than 14 days. Reasons for prolonged stay included both medical and social reasons. Direct postoperative complications were rarely responsible for prolonged hospital stay. Hip fractures constitute a significant burden on acute trauma services. Further strategies are needed to address both medical and social reasons for prolonged stay in hospital following hip fracture, as is a prospective national hip fracture audit to quantify the burden on the Irish health service. PMID- 19873870 TI - Implementation of spacer therapy for acute asthma in children. AB - The aim was to develop and implement an evidence based guideline for the treatment of acute asthma using a metered dose inhaler and spacer combination. Children admitted to Cork University Hospital Paediatric Department with acute asthma were identified during two identical 2 month seasonal periods before (2005) and after (2006) implementation of the new guidelines in September 2006. Pre-intervention and post-intervention audits by case note review were performed to determine the impact of and compliance with this evidence-based guideline emphasising patient assessment, spacer delivered bronchodilator and specific discharge criteria. Patients had similar characteristics during the two study periods. There was a raised threshold for admission after guideline implementation with 11/52 patients having mild exacerbations in 2006, compared to 21/36 in 2005. Duration of admission was less in the post-implementation group for equivalent exacerbation severity e.g. for moderate severity; 28 hours in 2005, 23 hours in 2006. Duration of bronchodilator therapy was shorter in 2006 and more likely to be given by spacer device earlier for equivalent levels of severity e.g. for moderate exacerbations, in 2006 the average length of salbutamol therapy was 18 hours with 12 hours by spacer device, in 2005 the average length of therapy was 25 hours with 3 hours by spacer. There was earlier initiation of oral corticosteroids; the average time to administration was 56 minutes in 2006 and 227 minutes in 2005. There was an improved documentation of asthma education in 2006 e.g. inhaler technique was reviewed in 37/52 in 2006, 21/35 in 2005 and better use of written action plans. PMID- 19873871 TI - Managing pandemic (H1N1) 2009. PMID- 19873872 TI - [Thrombin and anticoagulant therapy]. AB - New data which reveal rational approaches for pharmacologic control of blood coagulation process and confirm the key role of thrombin in haemostasis processes compared with other proteinases are presented in the review. Modulation of thrombin properties described in the review gives a new possibility for creating anti-thrombin preparations. Thrombin allosteria can serve a basis for development of new therapy. Creation of catalytically inert thrombin in slow-form within efficient anti-coagulant activity in vivo will allow using it in medicine as a unique anti-thrombin agent. PMID- 19873873 TI - [Jasmonic acid and its participation in defence reactions of plant organism]. AB - The main stages and inductors of biosynthesis of jasmonic acid and its derivatives, peculiarities of their content depending on the type of tissue, organ, plant age, mechanical irritation, injury and the impact of pathogens are considered. Data about use of mutant and transgenic plants with disturbed biosynthesis and perception of jasmonic acid for research ofjasmonate value in the induction of defense reactions are presented. Enzymes that are involved in the biosynthesis of jasmonic acid, synergistic (with abscisic acid, ethylene) and antagonistic (with salicylic acid) action of jasmonic acid with other phytohormones are described. There are data on the induction of jasmonic acid defense reactions in plants by the activation of genes encoding the synthesis ofthionins, extensins, phytoalexins and phenolic compounds. It is stressed that the ways of signal transmission for defense reactions induction are largely unknown and require further study. PMID- 19873874 TI - [Change in concentration of cytosolic Ca2+ caused by extracellular ATP and ecto ATP-ase activity in thymocytes and transformed MT-4 cells]. AB - The comparative study of extracellular ATP (ATP0) effect on free cytosolic calcium concentration ([Ca2+]i) in normal (isolated rat thymocytes) and transformed (leukosis MT-4 line) T-cells was carried out. Addition of 1 mM ATP to Ca-free incubation medium of both types of cells, loaded with indo-1, had no effect on [Ca2+]i level. Upon subsequent addition of 1 mM CaCl2 to the incubation medium the rapid and significant increase of [Ca2+]i in MT-4 cells was registered. This effect was maintained within 10 min and was not inhibited by phospholipase C inhibitor 0.2 mM neomycin, that was induced by cation entry into the cells from the extracellular medium. Both types of cells were shown to demonstrate ecto-ATPase activity in the presence of 1 mM MgCl2 or CaC12 in the incubation medium. Estimation of kinetic parameters has indicated that the maximum rate of extracellular ATP hydrolysis by MT-4 cells is higher and Mg2+ and Ca2+ activation constants are lower as compared to respective parameters of ATP hydrolysis by thymocytes. The possible functional significance of the increased level of ecto-ATPase activity in malignantly transformed cells is discussed. PMID- 19873875 TI - Possible pathways involved in activation of catalase and superoxide dismutase with sodium nitroprusside in yeast Saccharomyces cerevisiae. AB - The effect of nitric oxide (*NO) on biological systems depends very much on many circumstances. Nitric oxide can activate redox sensitive pathways that in many cases results in an increase of antioxidant potential of the cell. However, the direct effects of nitric oxide on the activity of principal antioxidant enzymes such as catalase and superoxide dismutase (SOD) have not been studied. In the present work we exploited the yeast model to elucidate a possibility of regulation of the mentioned activity by NO-donor sodium nitroprusside (SNP). We demonstrated that nitric oxide spontaneously generated at SNP decomposition increased the activity of catalase and SOD 1.3 times. Using inhibitors of mRNA (actinomycin D) and protein (cycloheximide) synthesis, the strain deficient in Yap1p, a master regulator coordinating yeast adaptive response to oxidative stress, we have found that these enzymes are up-regulated via synthesis of new molecules at transcription and translation levels. This response is mediated by Yap1p. Despite the increase of SOD activity in yeast cells possibly includes the activation of the present apoprotein by Ccs1p, the ways of nitric oxide regulation of Ccs1p activity are still unclear. PMID- 19873876 TI - [Particularities of arginase and NO-synthase pathways of L-arginine metabolism in leucocytes of peripheral blood of rats in conditions of chronic x-ray irradiation]. AB - Arginine takes part in many metabolic cell processes. It is not only involved in the dynamic cycle of interconversion with prolin and glutamine but also serves as a precursor for protein, nitric oxide, creatine, polyamines, agmatine and urea synthesis. Particularities of arginase and NO-synthase pathways of L-arginine conversion under the X-ray radiation in the leucocytes-radiosensitive cells of peripheral blood, under the per os administration of L-arginine and L-NAME (NG nitro-L-arginine methyl ester) to rats were detected. It was shown that both L arginine (arginase and NO-synthase main substrate) and L-NAME (nonspecific inhibitor of NO-synthase) had a positive correct influence on the organism in case of decreasing of NO overproduction under the X-ray radiation. PMID- 19873877 TI - [Transport and absorption of acetate in the gastrointestinal tract of white mice]. AB - Acetate absorbed in a thin, thick intestine and rectum, which is characterized by a repeated peak of concentrations in the blood of mice that is shown by research results. Absorption of acetate is paracellular and is carried out through a specific carrier. A possibility of compounds reabsorption under appropriate conditions is proved. PMID- 19873878 TI - [Effect of vitamin B1 structural analogue 3-decyloxycarbonylmethyl-4-methyl-5 (beta-hydroxyethyl) thiazole chloride on transmembrane current via ion channels formed by amphotericin B in bilayer lipid membrane]. AB - The structural analogue of vitamin B1 (thiamine)-3-decyloxycarbonylmethyl-4 methyl-5-(beta-hydroxyethyl) thiazole chloride (DMHT) introduced from the cis side of cholesterol-containing phospholipid bilayer membrane reversibly reduced the conductance induced by amphotericin B channels reconstituted from the same side of membrane. Introduction of DMHT (0.1 mM) from the cis-side of membrane blocked the amphotericin B-created conductance in symmetric solution of 100 mM KCI by 84 +/- 2%. The conductance of one-sided amphotericin B channels remained unaffected, when DMHT was introduced separately to the opposite trans-side of membrane. The kinetics of amphotericin B channels inhibition with DMHT showed no cooperativity allowing to expect that negatively charged ionogenic groups of these channels formed one DMHT binding site per channel as the slope of blocking rate determined in double-log coordinates was 1.5. Relatively high pK of binding with amphotericin B channels (5.13) suggests that this site provides high affinity interaction with DMHT. The comparative analysis of inhibition kinetics with the other blockers of amphotericin B channels--tetraethylammonium and tetramethylammonium has proved that DMHT is a comparable though much more potent substitute for both tetraalkylammonia. Hence, the DMHT was proposed as a novel powerful blocker for cation-selective channels with the size of the pore ranging between 0.28 nm and 0.385 nm. PMID- 19873879 TI - [Construction of immune library of murine immunoglobulin genes and screening of single-chain Fv-antibodies specific to diphtheria toxin B subunit]. AB - The aim of this work was to obtain the panel of recombinant single-chain Fv antibodies against diphtheria toxin B subunit, the main diagnostic and pathogenic antigen of Corynebacterium diphtheriae. For this purpose we have constructed the immune library of murine immunoglobulin genes. A number of scFv specific to diphtheria toxin B subunit were acquired from the obtained library after one round of selection by phage-display. ScFv encoding DNA-fragments of eight clones were subcloned into plasmid pET-22b(+). It was shown that selected scFv were highly specific to diphtheria toxin B subunit, with affinity constant for different clones ranged from 10(7) to 10(9) M(-1). PMID- 19873880 TI - [Effect of 17beta-estradiol on mRNA expression of Bax proapoptotic protein and DNA fragmentation level in the human adrenal cortex]. AB - The effect of 17beta-estradiol on the change of proapoptotic protein Bax mRNA level and DNA laddering in human adrenal cortex tissue was studied. The adding of 17beta-estradiol to incubation medium caused a decrease of the proapoptotic protein Bax mRNA level in adrenocorticocytes by 22% in comparison with control. Hormone influence decreases the DNA fragmentation by 50%. The obtained data suggest that 17beta-estradiol caused a significant antiapoptotic effect in human adrenal cortex. PMID- 19873881 TI - [Alpha-tocopherol prevents thymocyte death induced by antimycin A and oligomycin in rats]. AB - The influence of a-tocopherol, its structure analogues--alpha-tocopheryl acetate and a-tocopheryl quinone, ubiquinone (Q10), and also antioxidants quercetin and N acetyl-L-cysteine on rat thymocytes apoptosis and necrosis induced by antimycin A and oligomyci, accordingly, was investigated. It was established that alpha tocopherol completely restored the thymocytes survival independent of production of reactive oxygen species (ROS) by them. The degree of inhibition of ROS generation by the antioxidants having different antiradical activity did not correlate with their influence on thymocytes survival. Quercetin and N-acetyl-L cysteine reducing, to the greatest degree, the ROS level rendered the least effect on cell survival. Taken together, these results demonstrate that the ability of alpha-tocopherol to effectively prevent the rat thymocytes antimycin A and oligomycin-induced death is not determined by its antioxidant activity, but is possibly conditioned by prevention of mitochondrial dysfunction by stabilisation of mitochondrial membranes and modulation ofbioenergetic processes. PMID- 19873882 TI - [Signal transudation pathways in parietal cells of the gastric mucosa in experimental stomach ulcer]. AB - The goal of the presented work was the research of signal transduction mechanism in the rat gastric parietal cells under stomach ulcer conditions. In these cells activation of adenylate cyclase (increase of cAMP level and proteinkinase A activity) and phosphoinositide (increases [Ca2+]i; cGMP and phoshatidylinocitole levels; proteinkinase C, proteinkinase G, and calmodulin-dependent-proteinkinase activity) of signals pathway was shown. An increase of plasma membrane phospholipids (PC, PS, PE, PI, LPC) level was shown. Under conditions of influence of the stress factor the membran enzymes activity (H+, K+ -ATPase, 5' AMPase, Na+, K+ -ATPase, Ca2+, Mg2+ -ATPase and H+, K+ -ATPase) was considerably increased. The intensification of lipid peroxidation processes in rats was demonstrated. PMID- 19873883 TI - [Effect of stress on the content of free radical oxidation products in subcellular brain fractions in rats of pubertal age]. AB - The purpose of the present work is to study the influence of immobilization stress of different intensity on the content of protein and lipid oxidation products in subcellular brain fractions in rats of different age. It has been shown that 30-minute immobilization of 1.5-month, 2-month- and 12-month-old rats was not accompanied by accumulation of protein and lipid oxidation products in subcellular brain fractions. A prolonged immobilization of 1.5-month-old rats was accompanied by manifestations of oxidative stress in subcellular brain fractions; such manifestations were not characteristic of the rats of older age groups. PMID- 19873885 TI - [Effect of salicylic acid on water potential, ethylene secretion and activity of antioxidative processes in the winter wheat leaves under drought conditions]. AB - Effect of plants treatment by salicylic acid on the water potential, ethylene emission, intensity of lipid peroxidation oxidation and enzymatic antioxidative activity in the leaves with contrasting drought-resistance of winter wheat cultivars was investigated. It is ascertain, that the treatment of plants by salicylic acid contributes to a decrease of water loss and intensity of lipid peroxidation, to an increase of ethylene synthesis and peroxidase, catalase, superoxide dismutase activity in the winter wheat leaves under drought conditions. PMID- 19873884 TI - [Anti-inflammatory effect of N-stearoylethanolamine in experimental burn injury in rats]. AB - The biochemical mechanisms of anti-inflammatory effect of endocannabinoid congener N-stearoylethanolamine (NSE) was studied on the model of experimental burn in rats. The animals after the thermal burn of the skin received per os during 7 days the water suspension of NSE in a doze 10 mg/kg of body weight. In the other groups of rats the suspension was applied to the wound (the concentration of NSE was 10 mg/ml). It was shown for the first time that NSE accelerated the process of burn wound healing by the inhibition of proinflammatory cytokines (TNFalpha, IL-6) production. NSE caused the normalization of the iNOS and cNOS activity and of nitrite content in plasma, erythrocytes, liver and spleen of rats. NSE also modified the antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) activity and diminished the level of lipid peroxidation. The discovered anti-inflammatory NSE properties suggest the possibility of its usage for burn treatment. PMID- 19873886 TI - The world's most reviled genius. Can the scientist who denied the cause of AIDS be trusted to cure cancer? PMID- 19873887 TI - Healthcare has that IT factor. Xerox latest company to seek entry into market with proposed ACS deal. PMID- 19873888 TI - Forging stronger bonds. SEC seeking more transparency to aid investors. PMID- 19873889 TI - Largest rehabilitation providers. Ranked by number of free-standing rehabilitation hospitals, 2008. PMID- 19873890 TI - Putting madness in its place. PMID- 19873891 TI - Pandemic payoff. PMID- 19873892 TI - Shelling out for eggs. PMID- 19873893 TI - Still hotter than ever. PMID- 19873894 TI - Burying climate change. PMID- 19873895 TI - Easy go, easy come. PMID- 19873896 TI - Monopole position. PMID- 19873897 TI - Sewage's cash crop. PMID- 19873898 TI - How does the Coast Guard find people lost at sea? PMID- 19873899 TI - Keys to Copenhagen. PMID- 19873901 TI - Will E.T. look like us? PMID- 19873900 TI - A clunker of a climate policy. PMID- 19873903 TI - The long-lost siblings of the sun. PMID- 19873902 TI - How women can save the planet. PMID- 19873905 TI - A path to sustainable energy by 2030. PMID- 19873904 TI - New culprits in chronic pain. PMID- 19873906 TI - Rethinking the hobbits of Indonesia. PMID- 19873907 TI - The everything TV. PMID- 19873908 TI - The rise of vertical farms. PMID- 19873909 TI - The future of cars. Inteview by Stuart F. Brown. PMID- 19873910 TI - [Effects of electroacupuncture on in vitro fertilization-embryo transfer (IVF-ET) of patients with poor ovarian response]. AB - OBJECTIVE: To observe the effect of electroacupuncture therapy on oocyte quality and pregnancy outcome of patients with poor ovarian response or decreased reserve in the course of in vitro fertilization (IVF). METHODS: Sixty cases accepting IVF ET were randomly divided into an observation group and a control group, 30 cases in each group. The two groups were both treated with antagonist scheme for ovulation induction, and the electroacupuncture intervention was also added in the observation group, Guanyuan (CV 4), Taixi (KI 3), Sanyinjiao (SP 6) etc. were selected. The therapeutic effects in the two groups were compared after treatment. RESULTS: There was no significant difference between the two groups before treatment. The symptoms of kidney difficiency in the observation group were significantly improved after treatment, and the levels of serum estradiol (E2), fertilization rate, oocyte maturation rate, good quality embryos rate, and implantation rate in the observation group were superior to those in the control group on human Chorionic Gonadotropin (hCG) injection day (all P<0.05); the levels of stem cell factor (SCF) in follicular fluid and serum in the observation group were significantly higher than those in the control group (both P<0.05). The pregnancy rate in the observation group was higher than that in the control group, and the abortion rate in the observation group was lower than that in the control group, but there was no significant difference between the two groups (both P>0.05). CONCLUSION: Electroacupuncture therapy has a good clinical effect for IVF patients with poor ovarian reserve, and can improve oocyte quality and pregnancy outcome. PMID- 19873911 TI - [Randomized controlled study on influence of acupuncture for life quality of patients with chronic fatigue syndrome]. AB - OBJECTIVE: To observe effects of acupuncture on quality of life of patients with chronic fatigue syndrome (CFS). METHODS: Randomized, controlled and single blinded study method was used, 70 cases were divided into an observation group and a control group, 35 cases in each group. The observation group was treated with acupuncture at Baihui (GV 20), Danzhong (CV 17), Zhongwan (CV 12), Qihai (CV 6), Guanyuan (CV 4), Hegu (LI 4), Zusanli (ST 36), etc.; the control group was treated with acupuncture at non-meridian points (2 cm to the acupoints), thrice a week. The treatment was given for 14 times. The World Health Organization Quality of Life (WHOQOL-BREF) scale was used to evaluate the patients' quality of life before and after treatment. RESULTS: The physiological field, individuals own perception of his health condition and total score were significantly improved after treatment in the observation group (all P<0.05); there were no obvious changes in the psychology, social relationships, environment and subjective feelings about the quality of life (all P>0.05). The score of the environmental field in the control group was significantly decreased compared to that before treatment (P<0.05), and there were no significant changes in the other scores. There were no adverse effects in patients. CONCLUSION: Acupuncture can improve the quality of life of CFS patients, especially in physiological field and the individual perception to his well being. Acupuncture has high safety, and the acupoints has high specific degree than non-meridian points. PMID- 19873912 TI - [Effects of Linggui Bafa on the therapeutic effect and quality of life in patients of post-stroke depression]. AB - OBJECTIVE: To probe into effects of Linggui Bafa (method for picking eight points linked with extraordinary meridians according to time) on the therapeutic effect and quality of life in patients of post stroke depression. METHODS: One hundred and twenty cases were randomly divided into 3 groups, an observation group 1, an observation group 2 and a control group, 40 cases in each group. All patients were given routine clinical treatments and second level medical prevention. Patients in the observation group 1 received Linggui Bafa acupuncture treatment 2 weeks after stroke; at the same time the observation group 2 was treated with oral administration of Sertraline. The control group did not receive any form of either acupuncture or oral medication, but early rehabilitative intervention and psychological treatment were initiated. Curative effects were evaluated with Hamilton Depression Scale (HAMD), Function Independent Measure (FIM), National Institutes of Health Stroke Scale (NIHSS) and SF-36 after the treatment and 6 months later, respectively. RESULTS: The scores of HAMD, FIM (cognition function) and general health, role-physical, role-emotional, social function, vitality, mental health in SF-36 in the observation group 1 were significantly higher than those in the control group after treatment and 6 months later (P<0.01, P<0.05). The scores of physical function in SF-36 after treatment and NIHSS 6 months later in the observation group 1 were significantly improved than those in the control group (P<0.01, P<0.05). The scores of FIM (cognition function) and role-physical, social function, mental health in SF-36 after treatment and HAMD and general health, social function, mental health in SF-36 6 months later in the observation group 2 were significantly better than those in the control group (P<0.01, P<0.05). The scores of HAMD, FIM (cognition function) and general health, role emotional, social function, vitality, mental health in SF-36 in the observation group 1 were significantly improved than those in the observation group 2 after treatment and 6 months later (P<0.01, P<0.05). The scores of NIHSS and role physical in SF-36 in the observation group 1 were significantly higher than those in the observation group 2 6 months later (P<0.05). CONCLUSION: Acupuncture can improve depression symptoms and quality of life of patients with post stroke depression and the effects were better than Sertraline. PMID- 19873913 TI - [Observation on therapeutic effect of eye acupuncture on cognition disorders in patients of chronic cerebral circulation insufficiency]. AB - OBJECTIVE: To observe the therapeutic effect of eye acupuncture on cognition disorders in patients of chronic cerebral circulation insufficiency (CCCI). METHODS: Sixty cases were randomly divided into an observation group and a control group, 30 cases in each group. All patients were treated with oral administration of compound Danshen tablets, and the observation group was treated with eye acupuncture based on the pharmacotherapy and upper energizer area, kidney area, spleen area were selected. Their therapeutic effects were observed after 8 weeks. RESULTS: The total effective rate of 80.0% in the observation group was better than that of 53.3% in the control group (P<0.05). The score of mini-mental state (MMSE) in the observation group was also higher than that in the control group (P<0.05). CONCLUSION: Eye acupuncture has a good effect on cognition disorders in patients of CCCI and can enhance life quality of the patients. PMID- 19873914 TI - [Clinical observation on scalp point injection to improve the cerebral microcirculation for children of early cerebral palsy]. AB - OBJECTIVE: To explore an effective therapy for children of early cerebral palsy. METHODS: One hundred and twenty cases were randomly divided into an acupoint injection group and a medication group, 60 cases in each group. The acupoint injection group was treated with scalp point injection of 0.5-1 mL brain protein hydrolysate into each point, Baihui (GV 20), Fengchi (GB 20) and motor area etc. were selected; the medication group was treated with 10 mL brain protein hydrolysate by intravenous drip. The therapeutic effects in the two groups were observed, and the changes of cerebral blood flow were compared before and after treatment. RESULTS: The total effective rate of 91.4% in the acupoint injection group was superior to that of 73.7% in the medication group (P<0.05), the acupoint injection group could significantly improve the systolic peak velocity (Vs), end diastolic velocity (Ved) and mean velocity (Vm) of middle cerebral artery (MCA) and anterior cerebral artery (ACA), and decrease the vascular resistance index (RI) (all P<0.05), and the improvement degree was superior to the medication group (all P<0.05). CONCLUSION: Scalp point injection therapy can significantly improve the cerebral microcirculation of patients, and has a good therapeutic effect for early cerebral palsy. PMID- 19873915 TI - [Clinical observation on acupuncture for treatment of paralytic strabismus]. AB - OBJECTIVE: To compare therapeutic effects of acupuncture at local points of eye and western medicine on paralytic strabismus. METHODS: One hundred cases were randomly divided into an acupuncture group and a medication group. The acupuncture group (58 cases) was treated with acupuncture at local points of eye, Jingming (BL 1), Tongziliao (GB 1), Shangming (Extra) etc. were selected; and the medication group (42 cases) was treated with oral administration of Methycobal and Vitamin B1. After treatment of 5 courses, the therapeutic effects in the two groups were observed. RESULTS: The total effective rate of 94.8% in the acupuncture group was superior to that of 85.7% in the medication group (P<0.01); the therapeutic effects of the acupuncture group for treatment of oculomotor nerve and abducent nerve were significantly better than that of the medication group (P<0.05); the acupuncture group was better than the medication group in synoptophore examination results and improvement of rima oculi and pupil (P<0.01, P<0.05), the acupuncture group was superior to the medication group in improvement of the function of paralysis eye muscle, including medial rectus and lateral rectus except superior oblique (P<0.01, P<0.05). CONCLUSION: Acupuncture on local points of eye is an effective therapy for paralytic strabismus. PMID- 19873916 TI - [Controlled study on therapeutic effects of electroacupuncture and modified electric convulsive therapy on catatonic schizophrenia]. AB - OBJECTIVE: To evaluate the clinical therapeutic effect of electroacupuncture for treatment of catatonic schizophrenia. METHODS: Eighty cases were randomly divided into an observation group and a control group, 40 cases in each group. The observation group was treated with electroacupuncture, Baihui (GV 20) and Taiyang (EXHN 5) were selected, once daily; the control group was treated with modified electric convulsive therapy (MECT), the treatment was given once every 2 days or 3 days, 14 to 21 days constituted one course in the two groups. RESULTS: The markedly effective rate and total effective rate were 72.5% and 92.5% in the observation group, 77.5% and 97.5% in the control group, respectively, there was no significant difference between the two groups (both P>0.05). CONCLUSION: The therapeutic effect of electroacupuncture is similar to that of MECT. PMID- 19873917 TI - [Observation on therapeutic effect of He's Santong needling methods on cold erythema multiforme]. AB - OBJECTIVE: To search for an effective therapy for cold erythema multiforme in ham. METHODS: One hundred and eighty cases with cold erythema multiforme in ham were randomly divided into a Santong group (n=90) and a western medicine group (n=90). The Santong group was treated by He's Santong needling methods and Huantiao (GB 30), Fengshi (GB 31), Zusanli (ST 36), etc. were selected. The western medicine group was treated by oral administration of Cinnarizine, Cyproheptadine and Vitamin E. Two weeks later, their therapeutic effects were observed. RESULTS: The cured rate was 68.9% and the recurrence rate was 11.3% in the Santong group, and 33.3% and 53.3% in the western medicine group, with significant differences in the cured rate and the recurrence rate between the two groups (both P<0.01). CONCLUSION: He's Santong needling methods can increase the cured rate and reduce the recurrence rate of cold erythema multiforme in ham. PMID- 19873918 TI - [Analysis on theory of meridians and acupuncture manipulation based on ancient Shushu]. AB - The theories of Shushu in the literature of Qin and Han periods are reorganized and related expositions of foreign scholars are consulted, and Shushu theory is compared with the recordation in ancient medical books so as to probe into the relationship between Shushu and theory of meridians together with acupuncture manipulation. It is found that the eleven meridians system is the mathematical foundation of Five Shu Poits, Yuan-primary acupoints and the acupoints of all over the body, and which plays an important role in the theories of TCM. The exterior-interior relationship between viscera and meridians and circulation of ying-qi can be executed on the establishments of twelve meridians system. Shushu can affect needling instrument, needling methods, contraindications, etc. The construction of the meridians theory is full of philosophical dialectics, and it has certain subjectivity but does not influence the ancients to observe physiological phenomenon of viscera and meridians generally. PMID- 19873919 TI - [Application of hereditary "Promoting qi activating blood prescription" in clinical acupuncture and moxibustion]. AB - The present paper introduces the composition and clinical application of "Promoting qi Activating Blood Prescription" handed down from the great-great grandfather of the author, which can promote flow of qi and blood circulation. The prescription is composed of Jianshi (PC 5) and Sanyinjiao (SP 6) point. Its scope of treatment is very extensive and can be widely applied to many clinical diseases in departments of internal medicine, surgery, gynecology and orthopedics and traumatology, etc. For all the diseases and syndromes of retention of blood stasis and qi-stagnancy and blood stasis, if promoting flow of qi and blood circulation, this prescription will be available. PMID- 19873920 TI - [Effects of acupuncture and moxibustion on DNA excision repair-related proteins of bone marrow cell in cyclophosphamide-induced mice]. AB - OBJECTIVE: To explore the molecular biological mechanism of acupuncture and moxibustion for relieving myelosuppression and increasing white blood cells. METHODS: Two hundred and twenty-four clean male Kunming mice were randomly divided into a control group, a model group, an acupuncture group and a moxibustion group, 56 mice in each group. The model of myelosuppression was made with Cyclophosphamide. In the acupuncture group and the moxibustion group, acupoints "Dazhui" (GV 14), "Geshu" (BL 17), "Shenshu" (BL 23) and "Zusanli" (ST 36) were used for treatment with acupuncture and moxibustion, respectively, while, in the control group and the model group, there were no treatment carried out except catching and fixing. The changes of bone marrow cell DNA pol beta and XPD between the 2nd and 7th day were examined with immunohistochemical method. RESULTS: Acupuncture and moxibustion markedly up-regulated the expression of bone marrow cell DNA pol beta and XPD, and promoted the base excision repair and nucleotide excision repair, which leads to the relieving Cyclophosphamide-induced myelosuppression and increasing the number of white blood cells. CONCLUSION: For acupuncture and moxibustion, one of the bone major mechanisms in relieving post chemotherapy myelosuppression, protecting hemopoietic function and increasing the white blood cells is that it can promote the repair of the bone marrow cell DNA excision and protect hemopoietic cells from injury by chemical drugs. PMID- 19873921 TI - [Effects of auricular acupuncture on the memory and the expression of ChAT and GFAP in model rats with Alzheimer's disease]. AB - OBJECTIVE: To observe the effects of auricular acupuncture on the learning and memory abilities of model rats with Alzheimer's disease (AD), and investigate its mechanism. METHODS: Thirty SD rats were randomly divided into a control group, a model group and an auricular acupuncture group, 10 rats in each group. The model rats with AD were established by multiple injections with Okadaic Acid into the CA1 region of hippocampus. In the control group, the same quantity injection with Dimethyl Sulfoxide (DMSO) was applied on experimental rats. The auricular acupoints of "Nao" (brain) and "Shen" (kidney) were used for treating in the auricular acupuncture group, in contrast, the auricular region were not treated in the model and the control groups. The learning and memory capabilities of the rats were assessed with Morris Water Maze behavioral test, and the expressions of choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry. RESULTS: Comparing with the model group, the treated AD rats with auricular acupuncture was showed that the average escape latency was obviously shortened in the place navigation test (P<0.01), the movement time in plateform quadrant was obviously prolonged in the spatial probe test (P<0.05), and the number of traversing platform obviously increased (P<0.01) after the platform was taken away. The expression of ChAT increased in the hippocampus and cortex (P<0.01, P<0.05), but the expression of GFAP obviously decreased in the CA1 region of hippocampus (P<0.01). CONCLUSION: Auricular acupuncture can improve the learning and memory capability of the model rats with AD. Its mechanism might be related with decreasing cholinergic neuron damage and reducing the abnormal activation and hyperplasia of astrocyte. PMID- 19873922 TI - [Four seasons acupuncture and Five Shu Points]. AB - The method of four seasons acupuncture was initially recorded in the Internal Classic. It has the important meaning for understanding the contents of acupoints, especially the Five Shu Points. Its original meaning is that the place of acupuncture is difference on each season in order to cooperate with the both qi from the depth of acupuncture and four seasons. Through the interpretation from different aspects, the depth of qi is mainly considered as layer location and further considered as acupoints, and then gradually formed the principle of using the Five Shu Points. Following this way, we could correctly understand the contents of the Five Shu Points. PMID- 19873923 TI - [Differences in thinking model of treatment based syndrome differentiation between acu-moxibustion and internal medicine of TCM]. AB - The founding of clinical syndrome differentiation treatment system for acu moxibustion is an important issue for the development of clinical acupuncture practices, and it has attracted extensive attention in the domestic and overseas circles in acu-moxibustion field. At present, the syndrome differentiation treatment system of internal medicine of TCM is literally carried out in clinical acu-moxibustion practices, syndrome differentiation according to zang-fu is used instead of syndrome differentiation according to meridian, hence, it is difficult to reflect the features and advantages of acupuncture and moxibustion. Although the goals of acu-moxibustion and Chinese herbal medicine treatments are consistent, but the methods and approaches of the treatment are different. Therefore, the syndrome differentiation treatment system are not in concordance. Acu-moxibustion has gradually established unique thinking model of treatment based syndrome differentiation including principle, methods, prescription, points and technique which are different from principle, methods, prescription and drugs of internal medicine of TCM. PMID- 19873924 TI - [Application and development of cohort study in Chinese medicine]. AB - To evaluate the cohort study in Chinese medicine research, especially in acupuncture study field. This paper introduced the concepts, methods and applications of cohort study; furthermore, it introduced the applications and progress of cohort study in clinical Chinese medicine research at present. In China, cohort study has been mainly used in Chinese medicine research focusing on tumors, any researches using cohort study in acupuncture were not retrieved. Contrarily, the cohort study has been used earlier and advocated to apply in abroad acupuncture research. As one of methods in classic epidemiological observational studies, cohort study is fit to evaluate clinical researches of Chinese medicine and acu-moxibustion, so it is worthy of being promoted in applications. PMID- 19873925 TI - [Study on needling Ying method for treatment of sore throat]. AB - To explore the mechanism of needling Ying method for treatment of sore throat. By the analysis of pathogenesis of sore throat, the authors think the key of its pathogenesis is stagnation of pathogenic factors such as hotness and phlegm accumulating, and meridian-vessel obstruction in the throat is its meridian foundation. There are several meridians passing through the throat, so the throat is closely related to viscera and meridians, and stagnation of pathogenic factors such as hotness and phlegm accumulating in the throat lead to sore throat when exogenous pathogenic factors invading or dysfunction of viscera and meridians. The treatment of needling Ying at local throat or combined with corresponding meridian point selection can dredge collaterals, dispel pathogenic factors, remove pathogenic factors to dispel swelling, resolve phlegm and dissipate stagnation and harmonize yin and yang, so as to relieve sore throat. In conclusion, needling Ying method is an important method in the treatment of sore throat. PMID- 19873926 TI - [Discussion on reinforcing-reducing manipulations of acupuncture in Internal Classic]. AB - To study and analyze the reinforcing-reducing manipulations of acupuncture in Internal Classic. The major methods of reinforcing-reducing manipulations of acupuncture in Internal Classic were reinforcing-reducing by manipulating the needle in cooperation with the patient's respiration, reinforcing-reducing effect induced by slow and quick manipulation of needle, and open-close reinforcing reducing manipulation, these three methods were usually applied in combination. All of reinforcing-reducing manipulations should be based on the principle of puncturing along and against the flowing direction of the meridian qi. Mastering the reinforcing-reducing manipulations of acupuncture in Internal Classic will contribute to the improvement of therapeutic effects in clinical practice. PMID- 19873927 TI - [Systematic evaluation of therapeutic effect of acupuncture for treatment of simple obesity]. AB - OBJECTIVE: To evaluate the therapeutic effect of acupuncture for treatment of simple obesity, and to analyze the current situation of clinical studies. METHODS: Randomized controlled trials (RCTs) involving acupuncture treatment for simple obesity were searched from PubMed (1979-2008), OVID (1979-2008), EBSCO (1973-2008), Cochrane Library (Issue 2, 2008), CBM (1978-2008), CNKI (1979-2008), VIP (1989-2008) and WanFang Database (1998-2008). Literatures were enrolled focusing on RCTs related to acupuncture treatment for simple obesity; the quality of literatures were evaluated by two evaluators unaidedly. Meta-analyses were conducted with the Cochrane Collaboration's RevMan 4.2.8 software. RESULTS: Eight papers including 1,017 cases, conformed with the enrolled criteria. Meta-analyses showed that there were significant difference between acupuncture groups and western medicine groups in the effective rate [combined RR (fixed effects model) = 1.11, 95% CI (1.05, 1.18), P=0.0006]. There was a significant difference between acupuncture and Sibutramine in the body mass [combined WMD (fixed effects model) = 1.94, 95%CI (1.73, 2.16), P<0.00001] and body mass index (BMI) [combined WMD (fixed effects model) = 0.52, 95% CI (0.33, 0.70), P<0.00001]. However, acupuncture was not superior to Sibutramine in hip circumference (HC) [combined WMD (fixed effects model) = -0.35, 95% CI (-0.56, -0.15), P<0.0007]. CONCLUSION: For treating simple obesity, besides reasonable diet and exercise, acupuncture is safe and effective, which may be more effective than routine western medicine. The quantity of literature was limited and the quality of some literatures was low. Thus, more high-quality and large-scale of RCTs are needed. PMID- 19873928 TI - [The use of politetrafluoroethylene stent-graft and vena cava filter in the endovascular treatment of ruptured abdominal aortic aneurysm with aortocaval fistula]. AB - We report on a the endovascular treatment of ruptured abdominal aortic aneurysm with aortocaval fistula. The stent-graft was placed with the patient under general anaesthesia, and the abdominal aorta aneurysm was successfully treated. To prevent pulmonary embolism vena cava filter was deployed before the implantation of the sten-graft. The aneurysm was excluded and no endoleak or communication between the aorta and inferior vena cava was seen on computed tomographic imaging at the 3-month evaluation. Endovascular treatment offers an attractive therapeutic alternative to open repair in case of aortocaval fistula. PMID- 19873929 TI - [The application of Harpagophytum procumbens extract in anti-inflammatory preparations applied on skin produced on acrylic acid polymers base]. AB - An attempt was made to use dry standardized extract from Harpagophytum procumbens of confirmed anti-inflammatory activity in formulations applied on skin. To obtain synergy in the area of analgesic and anti-inflammatory activity formulations were produced containing plant extract and nonsteroidal anti inflammatory drug (ketoprofen). All the preparations were prepared on the base of acrylic acid polymers (Carbopol Ultrez 10, Carbopol 980). The formulations were subjected to complementary physicochemical investigations. Viscosity parameters (structural viscosity, yield stress, thixotrophy) were determined with cone-plate digital rheometer. Potentiometric method was used to measure pH of the produced hydrogels. The test for ketoprofen pharmaceutical availability through a semipermeable membrane to acceptor fluid was performed in vitro. The rate of the process of release was tested by determining the quantity of the therapeutic agent diffusing into acceptor fluid at defined time intervals by spectrophotometric method. The effect of Harpagophytum procumbens extract components on ketoprofen diffusion was estimated. Viscosity tests revealed that all the formulations are viscoelastic systems having yield stress. All model formulations were tested 24h after production and after 6-month storage. All the formulations demonstrate rheological stability and high pharmaceutical availability of ketoprofen. The suggested formulations can be an alternative for market preparations applied on skin of anti-inflammatory and analgesic activity. PMID- 19873930 TI - [Glicol plant extracts of anti-inflammatory activity in hydrogels produced on Carbopol base]. AB - Medications originating from plants can be successfully applied in the treatment of rheumatic pain beside those from the nonsteroidal anti-inflammatory drugs (NSAIDs). An attempt was made to produce a new form of a drug applied on skim, which contains NSAID and glycol plant extract in its composition. The aim of the study was to obtain synergy in the area of analgesic and antiinflammatory activity. Formulations containing NSAID (ketoprofen) and formulations containing glycol plant extracts of confirmed anti-inflammatory and analgesic activity (extract from sage, extract form arnica) were produced on the basis of acrylic acid polymers (Carbopol Ultrez 10, Carbopol 980). Moreover, formulations were also produced containing ketoprofen and glycol plant extract in their composition. Viscosity parameters of the tested formulations (structural viscosity, yield stress, thixotrophy)were determined with cone-plate digital rheometer. Potentiometric method was used to measure pH of the produced hydrogels. The test for therapeutic agents pharmaceutical availability was performed with membrane method. Spectrophotometric method was used to estimate the quantity of the released therapeutic agent. The usefulness of acrylic acid polymers (Carbopol Ultrez 10, Carbopol 980) was assessed for the application in the prescription of dermatological hydrogels as well as their compatibility with ketoprofen and active substances contained in glycol plant extracts. Pharmaceutical availability was tested of ketoprofen and therapeutic agents contained in the investigated plant extracts. Furthermore, the effect of the components of extracts on the process of ketoprofen release to acceptor fluid through a semipermeable membrane was estimated. PMID- 19873931 TI - [Dry plant extracts in the prescription of dental hydrogels with Carbopol 971P]. AB - The study assumption was to work out a prescription for dental anti-inflammatory hydrogel on Carbopol 971P base. Dry plant extracts (sage, horsetail) and nonsteroidal anti-inflammatory drug (sodium ibuprofen) were introduced into the prescription of a model hydrogel. The aim of the study was to estimate pharmaceutical availability of the applied therapeutic agents and to test their effect on physicochemical properties of the produced form of a drug. The physicochemical parameters of the produced preparation were tested. Viscosity tests were performed using cone-plate digital rheometer. Extensometric method was used to test extensibility. pH measurements were performed by direct immersing the electrode connected with pH-meter into the hydrogel samples of uniform mass. Pharmaceutical availability of therapeutic agents contained in hydrogel (active components of plant extracts, sodium ibuprofen) was estimated. The rate of the process of mass exchange was tested by spectrophotometric method determining the quantity of therapeutic agents diffusing into acceptor fluid at the same time intervals. Sodium ibuprofen is better released from the hydrogel containing horsetail extract (815.5 c.u.) than from the hydrogel of parallel prescription containing sage extract (640.8 c.u.). Hydrogels containing dry extract from horsetail have greater extensibility and lower structural viscosity as well as the value of yield stress than equivalent hydrogels containing sage extract. Introduction of sodium ibuprofen into the prescription of hydrogels with plant extracts modifies rheological parameters (greater extensibility, lower viscosity of the preparation). The tests of the kinetics of therapeutic agents release demonstrated that the presence of sodium ibuprofen in the prescription of hydrogels exerts an influence on the decrease of the effectiveness of the release of active substances contained in these extracts. PMID- 19873932 TI - The influence of lidocaine hydrochloride on environmental pH changes of diluted dispersions of poly(N-isopropylacrylamide) below and over the LCST. AB - In this study we assessed the influence of lidocaine hydrochloride on the pH of diluted aqueous dispersions of modified poly(N-isopropylacrylamide), at temperature assigned as normalized skin surface temperature, and below and over the lower critical solution temperature value. Three different N isopropylacrylamide polymer derivatives were synthesized by surfactant free emulsion polymerization, and assessed in the terms of pH in the aqueous dispersions in the presence and absence oflidocaine hydrochloride. The tendency in observed system was similar at three different temperatures, when lidocaine was applied. The pH value increased from the range between 5,39 - 5,90 up to the range 6,22 - 6,55. However, the step of pH between the temperature of 25 degrees C and 32 degrees C was more radical, comparing to 32 degrees C and 45 degrees C. The lidocaine hydrochloride influences the pH patterns observed at various temperature in polymeric systems: measurements of preparations applied on the skin or mucosa should be evaluated in respective temperature range. PMID- 19873933 TI - The pH changes of diluted dispersions of poly(N-isopropylacrylamide) below and over the LCST in the presence of chlorhexidine. AB - The pH of diluted aqueous dispersions of modified poly(N-isopropylacrylamide) with chlorhexidine was evaluated, at normalized skin surface temperature, as well below and over the lower critical solution temperature value. Three different poly-N-isopropylacrylamides were synthesized by surfactant free emulsion polymerization. They were evaluated in the terms of pH in the aqueous dispersions in the presence of chlorhexidine. The tendency was similar in all investigated systems at increasing temperature between 25 degrees C and 45 degrees C. The pH value decreased from the range between 9.87-9.94 down to the range 9.38-9.46. The course of pH decrease between the temperature of 32 degrees C and 45 degrees C was more radical, comparing to 25 degrees C and 32 degrees C, however in general the decrease was monotonic. The systems with chlorhexidine tend to change the pH with temperature increase more radically, in the comparison to the chlorhexidine alone. The formulations applied on the skin surface or in the oral cavity should be evaluated in proper temperature spectrum. PMID- 19873934 TI - [The use of the synthetic silver coated prosthesis and penduculated omentum flap in the treatment of prostheses infection]. AB - There is a methods of surgical treatment of secondary enteroaortal fistula after infection of vascular prostheses with the use silver prosthesis and great omentum. Secondary enteroaortal fistula is the most serious complication followed infection of vascular prosthesis, with high risk of death rate regardless of different operative methods. Patients is operated and the dracon prosthesis was exchanged to arterial homograft, which is more resistant to infections or subclavio-femoral bypasses. Removing of intestinal fistula included resection of duodenum and gastroenterotomy or duodenorrhaphy. The modification of duodenal fistula provision relies on duodenorraphy and protection of that area and prosthesis with pediculated flap of gastrocolic omentum conducted retrocolicaly in retroperitoneum space. The retrocolical and retroperitoneal omentoplasty seems to be a practical modification of aorto-duodenal fistula treatment with useful protection of duodenal plastic. PMID- 19873935 TI - Evolving technological changes and the impact on our profession. PMID- 19873936 TI - Radiation therapy of prostate cancer: rationale, pitfalls and the continuing prospect of success forged by medical physics. AB - Radiation therapy aimed at curing prostate cancer forms a considerable workload in most contemporary radiation oncology departments. The wide range of currently available therapeutic strategies for this cancer and their increasing complexity further increases the impact these patients have within the treating unit. Grounded in basic anatomy, physiology and pathology, the rationale for the division of prostate cancers into different prognostic and therapeutic groups is discussed, and put into clinical context using the current research evidence base. Weaknesses in this evidence base are highlighted in relation to areas directly impacted on by the work of medical physics. PMID- 19873937 TI - Effects of collimator backscatter in an Elekta linac by Monte Carlo simulation. AB - The effects of radiation backscattered from the secondary collimators into the monitor chamber in an Elekta linac (producing 6 and 10 MV photon beams) are investigated using BEAMnrc Monte Carlo simulations. The degree and effects of this backscattered radiation are assessed by evaluating the changes to the calculated dose in the monitor chamber, and by determining a correction factor for those changes. Additionally, the fluence and energy characteristics of particles entering the monitor chamber from the downstream direction are evaluated by examining BEAMnrc phase-space data. It is shown that the proportion of particles backscattered into the monitor chamber is small (< 0.35%), for all field sizes studied. However, when the backscatter plate is removed from the model linac, these backscattered particles generate a noticeable increase in dose to the monitor chamber (up to approximately 2.4% for the 6 MV beam and up to 4.4% for the 10 MV beam). With its backscatter plate in place, the Elekta linac (operating at 6 and 10 MV) is subject to negligible variation of monitor chamber dose with field size. At these energies, output variations in photon beams produced by the clinical Elekta linear accelerator can be attributed to head scatter alone. Corrections for field-size-dependence of monitor chamber dose are not necessary when running Monte Carlo simulations of the Elekta linac operating at 6 and 10 MV. PMID- 19873938 TI - Improved observer dependent perception of weak edges when scanning an image in real time indicated by introducing 1/f noise into the primary visual cortex V1. Theory and experimental support. AB - We present results of a new process for generating 1/f type noise sequences and introducing the noise in the primary visual cortex which then enables improved perception of weak edges when an observer is scanning a complex image in real time to detect detail such as in mammogram reading sessions. It can be explained by an adaptation of information theory for functional rather than previous task based methods for formulating processes for edge formation in early vision. This is enabled from a two "species" classification of the interaction of opposing on centre and off-centre neuron processes. We show that non-stationary stochastic resonances predicted by theory can occur with 1/f noise in the primary visual cortex V1 and suggest that signalling exchanges between V1 and the lateral geniculate nucleus (LGN) of the thalamus can initiate neural activity for saccadic action (and observer attention) for weak edge perception. Improvements predicted by our theory were shown from 600 observations by two groups of observers of limited experience and an experienced radiologist for reference (but not for diagnosis). They scanned and rated the definition of microcalcification in clusters separately rated by the experienced radiologist. The results and supporting theory showed dependence on the observer's attention and orderly scanning. Using a compact simplified equipment configuration the methodology has important clinical applications for conjunction searches of features and for detection of objects in poor light conditions for vehicles. PMID- 19873939 TI - Half-value layer measurement: simple process method using radiochromic film. AB - Although the half-value layer (HVL) is one of the important parameters for QA and QC, constant monitoring has not been performed because the measurements using an ionization chamber (IC) are time-consuming and complicated. To solve these problems, the use of radiochromic film (GAFCHROMIC XR TYPE R: GAF-R) with step shaped aluminum (Al) filters, referred to herein as the simple process method, has been developed. The measurement X-ray tube voltages were 120 kV, 100 kV, and 80 kV. The Al filter area, the full exposure area, and the unexposed area were set on the GAF-R so as to obtain correct data. The HVL was evaluated using the density attenuation ratio. The HVLs obtained using the GAF-R and an 1C dosimeter were compared. HVLs with X-ray tube voltages of 120 kV, 100 kV, and 80 kV using the GAF-R were 4.10 mm, 3.55 mm and 2.97 mm, respectively. The difference ratios of the HVLs using the GAF-R and the IC were 1.2%, 7.6%, and 10.0%, respectively. The HVL at 120 kV can be routinely and quickly measured using the simple process method. Therefore, an IC dosimeter is not needed for HVL measurements for QA and QC. However, the HVL measurements of low energy (100 kV and 80 kV) need attention. PMID- 19873940 TI - ECG interference suppressed using a harmonic generator. AB - Non-linear loading of the utilities supply introduced significant electromagnetic field (EMF) interference severe enough to disrupt electrocardiograph (ECG) monitoring and recordings in the new Emergency Department (ED) at the Royal Melbourne Hospital (RMH). This interference was evident even though standard Mu metal shielding had been installed over the main hospital power feed which runs underneath the department. Investigations revealed that the source of the interference was due to 3rd harmonic currents flowing in the mains cable. This interference was suppressed by introducing third harmonic current into the main power cable in anti-phase to the interfering signal. PMID- 19873941 TI - Milwaukee police department retirees: cardiovascular disease risk and morbidity among aging law enforcement officers. AB - This study explored the self-reported prevalence of cardiovascular disease (CVD) and accompanying risk factors among 165 male retirees 43 years and older (M = 56.2, SD = 7.1) from the Milwaukee Police Department (MPD) compared to 671 individuals of similar age and income who responded to the 2005 Wisconsin Behavioral Risk Factor Surveillance System (BRFSS). CVD and other risk factors were more prevalent in the MPD retirees than the general population (CVD 15.2% vs. 9.5%, p = .036; hypertension 51.5% vs. 36.2%, p = .001; hypercholesterolemia 62.4% vs. 44.4%, p = .001; overweight and obesity 85.1% vs. 74.7%, p = .005). In addition, other factors associated with CVD prevalence included working in law enforcement (odds ratio = 1.70; 95% confidence interval = 1.03 to 2.79). Results suggest an association between employment in law enforcement and an increase in CVD morbidity. PMID- 19873942 TI - Factors affecting Thai workers' use of hearing protection. AB - This study used an ecological model to examine Thai workers' beliefs and attitudes toward using occupational hearing protection. Data collection involved focus group sessions with 28 noise-exposed workers at four factories in Chiang Mai Province and an interview with a safety officer at each organization. Detailed content analysis resulted in the identification of three types of factors influencing the use of hearing protection: intrapersonal, including preventing impaired hearing, noise annoyance, personal discomfort, and interference with communication; interpersonal, including coworker modeling, supervisor support, and supervisor modeling; and organizational, including organizational rules and regulations, provision of hearing protection devices, dissemination of knowledge and information, noise monitoring, and hearing testing. Effective hearing protection programs depend on knowledge of all of these factors. Strategies to promote workers' use of hearing protection should include the complete range of factors having the potential to affect workers' hearing. PMID- 19873943 TI - Outcome study of unilateral lateral rectus recession for small to moderate angle intermittent exotropia in children. AB - PURPOSE: To report an outcome study of 100 consecutive children with intermittent exotropia treated by unilateral rectus recession for small to moderate angle exodeviation with a minimum follow-up of 6 months. METHODS: The records of patients with intermittent exotropia younger than 15 years who underwent 7-to-10 mm unilateral lateral rectus recession for exodeviation measuring 15 to 35 prism diopters (PD) from January 2000 to July 2008 were retrospectively reviewed. The surgery were performed accordingly to the amount of distance deviation. A successful alignment was defined as an exodeviation of 5 PD or less and absence of any esotropia in primary and lateral gaze while viewing distant or near targets. RESULTS: Successful alignment was achieved in 99%, 88%, and 76% of patients at early postoperative, 6-month, and final follow-up, respectively. One overcorrected patient had an esodeviation of 20 PD at 6 months. The results of the final follow-up did not depend on age or refraction at the level of 0.05, whereas the amount of initial exodeviation was found to be significantly correlated with success at the final examination (P = .041). There was a positive significant relationship between results at 6 months and final follow-up (P = .000, r = 0.449). Eleven of the 13 patients who had a second surgery and were observed more than 6 months had successful alignment. Eighty-nine percent of the patients achieved a successful outcome with the combined primary and secondary surgery at the final follow-up. CONCLUSION: Unilateral lateral rectus recession is a safe and effective treatment for small to moderate angle intermittent exotropia in children. PMID- 19873944 TI - Successful Surgical Intervention for Childhood Pterygium Using a Conjunctival Autograft. AB - Childhood pterygia are extremely rare and no consensus currently exists regarding surgical management in cases of significant symptomatology. The authors describe a case of a childhood pterygium in a 9-year-old boy successfully treated with a superior conjunctival autograft. At 6 months of follow-up, no signs of recurrence were detected and the patient reported marked improvement in symptoms. Use of this technique may be beneficial in certain cases of childhood pterygia. PMID- 19873945 TI - Is buckle surgery still the state of the art for retinal detachments due to retinal dialysis? AB - PURPOSE: Retinal dialysis is a frequent cause of retinal detachment in infants and young adults. The authors report long-term results obtained with conventional detachment surgery in a large consecutive series. METHODS: Fifty-two eyes of 50 patients with retinal detachment due to dialysis underwent a segmental buckling procedure between January 1990 and December 1998. Patient characteristics and surgical results at 1 year of follow-up were evaluated. In 2007, 40 eyes from these groups were reexamined for long-term results (follow-up: 9 to 17 years; median: 13.4 years). RESULTS: The mean age of the patients was 12.8 years (range = 6 to 28 years). Preferred locations of the dialyses were inferotemporal (72%) and superonasal (16%). The macula was detached in 82%. At 1 year of follow-up, the retina was completely reattached after one surgical procedure in 87% and after two procedures in 97%. Long-term follow-up of 40 of 52 eyes revealed no retinal redetachment, but additional surgeries had been performed. Visual acuity improved in 70% of the eyes, but only 40% reattained reading vision due to the high rate of macula-off retinal detachment preoperatively. CONCLUSION: Scleral buckling for retinal detachment due to dialysis yields good results, even in the long term, and remains the treatment of choice for these usually young patients despite the increasing popularity of primary vitrectomy. PMID- 19873946 TI - Isolated Anterior Chamber Relapse in a Child with Chronic Myeloid Leukemia: Masquerade Syndrome. AB - The authors report a case of anterior uveitis with hypopyon that was refractory to topical corticosteroid therapy. A detailed history revealed that the patient had chronic myeloid leukemia. Cytology in the aqueous humor was consistent with relapse of chronic myeloid leukemia. PMID- 19873947 TI - Simultaneous Occurrence of Glial Heterotopia and Meningocele in the Orbit with Clinical Anophthalmia and Neurological Anomalies. AB - The authors describe a 5-year-old boy who had three congenital anomalies (clinical anophthalmos, meningocele, and glial heterotopia) in the orbit. These were associated with multiple neurological anomalies. PMID- 19873948 TI - A new transconjunctival muscle reinsertion technique for minimally invasive strabismus surgery. AB - PURPOSE: To describe a novel, minimally invasive strabismus surgery (MISS) technique for horizontal rectus muscle recessions, plications, and advancements. METHODS: Subjects for this prospective study were the first 20 consecutive patients who underwent unilateral horizontal rectus muscle surgery with a transconjunctival suturing (TRASU) technique for primary muscle displacements of 4.5 mm or greater or for repeat muscle displacements of 3.0 mm or greater. RESULTS: The TRASU technique was associated with no increase in complication rate and was accomplished through a conjunctival approach with an incision that was smaller by 31% +/- 11% compared to incisions for previously described MISS approaches. Of the 19 patients (20 eyes) returning for follow-up, 11 (55%) had minimal redness as the only grossly visible sign of surgery on the first postoperative day. By 6 months postoperatively, visual acuity and refractive error were not significantly different from preoperative values (P > .10 for each). CONCLUSION: The TRASU technique is safe and can be accomplished through a conjunctival incision that averages two-thirds the size of incisions for previously reported MISS techniques. PMID- 19873949 TI - Macular Abnormality Observed by Optical Coherence Tomography in Children with Amblyopia Failing to Achieve Normal Visual Acuity After Long-Term Treatment. AB - PURPOSE:To investigate why some children with amblyopia fail to achieve normal visual acuity. METHODS:Optical coherence tomography (OCT) was performed to observe the morphology of the macular tissue of children with various types of amblyopia who failed to achieve normal visual acuity (, |5,0(-)>, |8,0(+)> and |4,0(-)>|2> vibrational states of H(2)O [ Callegari , A. ; et al. Science 2002 , 297 , 993.]. To link the measured Stark coefficients with the dipole surface, we analyze our results using a coupled anharmonic oscillator model, which takes into account the local-mode nature of higly excited OH stretching vibrations in water, and the tunneling between the two equivalent bonds. The large inertial frame tilt associated with the local-mode bond stretching results in a complex interaction between rotational-, vibrational-, and tunneling-motion, all of which become deeply entangled in the Stark coefficients. A perturbational approach makes it possible to analyze the problem at increasingly higher levels of approximation and to disentangle the different contributions, according to the different time scales involved. This simple model reproduces most experimental values to within a few percent, even for these highly vibrationally excited levels, and gives valuable insight into the complex rotational and vibrational motions that link the dipole moment surface with the Stark coefficients. PMID- 19873973 TI - A single-component molecular metal based on a thiazole dithiolate gold complex. AB - A single component molecular conductor has been isolated from electrocrystallization of the monoanionic gold bis(dithiolene) complex based on the N-ethyl-1,3-thiazoline-2-thione-4,5-dithiolate (Et-thiazdt) ligand. The crystal structure of the system exhibits layers built from parallel uniform one dimensional stacks of the planar molecule. At room temperature and ambient pressure the system is semiconducting (0.33 S x cm(-1)) with a small activation energy. However, the single crystal conductivity is strongly pressure dependent reaching 1000 S x cm(-1) at 21 kbar. At 13 kbar there is a crossover between semiconducting and metallic regimes. Thus, the present system is the first well characterized single-component molecular metal without TTF dithiolate ligands. First-principles DFT calculations show that the ground state is antiferromagnetic with a very small band gap. A simulation of the effect of pressure on the electronic structure provides a rationale for the observed variations of the conductivity and gives insight on how to further stabilize the metallic state of the system. PMID- 19873974 TI - Azaindole hydroxamic acids are potent HIV-1 integrase inhibitors. AB - HIV-1 integrase (IN) is one of three enzymes encoded by the HIV genome and is essential for viral replication. Recently, HIV-1 IN inhibitors have emerged as a new promising class of therapeutics. Herein, we report the discovery of azaindole carboxylic acids and azaindole hydroxamic acids as potent inhibitors of the HIV-1 IN enzyme and their structure-activity relationships. Several 4-fluorobenzyl substituted azaindole hydroxamic acids showed potent antiviral activities in cell based assays and offered a structurally simple scaffold for the development of novel HIV-1 IN inhibitors. PMID- 19873975 TI - Unexpected inversions in asymmetric reactions: reactions with chiral metal complexes, chiral organocatalysts, and heterogeneous chiral catalysts. PMID- 19873977 TI - Transition metal catalyzed alkene and alkyne hydroacylation. PMID- 19873976 TI - Characterization of copolymer latexes by capillary electrophoresis. AB - Latexes are widely used for industrial applications, including decorative paints, binders for the papermaking industry, and drilling fluids for oil-field applications. In this work, the interest of capillary zone electrophoresis (CE) for the characterization of hydrophobic block copolymer latexes obtained by the conventional emulsion polymerization technique consisting of a core of polystyrene (PS) surrounded by a layer of poly(ethyl acrylate) (PEA) has been investigated. The PEA part of the copolymer can be partially hydrolyzed in poly(acrylic acid) (PAA) leading to PS-PEA-AA water-soluble amphiphilic copolymer having high viscosifying properties. The main purpose of this work was to evaluate the potential of CE for the characterization of the latexes at the different stages of the synthesis (PS core, PS-PEA diblock latex, and hydrolyzed PS-PEA-AA gel). The main analytical issues were to state (i) if there was free PS or PEA homopolymer latexes in the PS-PEA latex sample and (ii) if there was free PS, PEA, PS-PEA latexes, or free PAA chains in the PS-PEA-AA gel. Within this scope, this work describes the optimization of the selectivity of the separation between the different species (PS, PEA particles in the not hydrolyzed diblock latex and PS, PEA, PS-PEA particles as well as the polymer PAA chains in the PS PEA-AA diblock gel sample obtained by latter latex hydrolysis). For that purpose, several experimental parameters were investigated such as pH and ionic strength of the background electrolyte (BGE) or the concentration of neutral surfactant added in the BGE. A challenging issue was to overcome the high viscosity of the PS-PEA-AA gel. This was resolved by the addition of 10 mM neutral surfactant in the gel sample and in the BGE. Finally, it is demonstrated that, within the detection limits, CE is a suitable analytical tool for controlling and monitoring the syntheses of these latexes and for intrinsically characterizing the distribution in charge density of the final PS-PEA-AA gel at different hydrolysis rates. PMID- 19873978 TI - Recombinant differential anchorage probes that tower over the spatial dimension of intracellular signals for high content screening and analysis. AB - Recombinant fluorescent probes allow the detection of molecular events inside living cells. Many of them exploit the intracellular space to provide positional signals and, thus, require detection by single cell imaging. We describe here a novel strategy based on probes capable of encoding the spatial dimension of intracellular signals into "all-or-none" fluorescence intensity changes (differential anchorage probes, DAPs). The resulting signals can be acquired in single cells at high throughput by automated flow cytometry, (i) bypassing image acquisition and analysis, (ii) providing a direct quantitative readout, and (iii) allowing the exploration of large experimental series. We illustrate our purpose with DAPs for Bax and the effector caspases 3 and 7, which are keys players in apoptotic cell death, and show applications in basic research, high content multiplexed library screening, compound characterization, and drug profiling. PMID- 19873979 TI - Asymmetrical diaromatic guanidinium/2-aminoimidazolinium derivatives: synthesis and DNA affinity. AB - In this paper we report the synthesis of three families of new amidine-based aromatic derivatives as potential DNA minor groove binding agents for the treatment of cancer. The preparation of monoguanidine, mono-2-aminoimidazoline, and asymmetric diphenylguanidine/2-aminoimidazoline derivatives (compounds 1a-c to 8a-c) is presented. The affinity of these substrates and of a family of mono- and bis-isoureas (previously prepared in Rozas' laboratory) for DNA was evaluated by means of DNA thermal denaturation measurements. In particular, compounds 2c, 5c, 6c, 7c, and 8c were found to bind strongly both to natural DNA and to adenine thymine oligonucleotides, showing a preference for the adenine-thymine base pair sequences. PMID- 19873980 TI - Characteristic energies and shifts in optical spectra of colloidal IV-VI semiconductor nanocrystals. AB - We investigate structural, electronic, and optical properties of colloidal IV-VI semiconductor quantum dots (QDs) using an ab initio pseudopotential method and a repeated supercell approximation. In particular, rhombo-cuboctahedral quantum dots consisting of PbSe, PbTe, and SnTe with a pseudohydrogen passivation shell are investigated for different QD sizes. The obtained dependence of the confinement energy on the QD size questions the use of three-dimensional spherical potential well models for small QD structures. The predicted band gaps are almost in agreement with measured values. The calculated Franck-Condon shifts vary significantly with the QD size. Only for PbSe they may explain the Stokes shift between optical absorption and emission. For the tellurides, spectral properties such as the oscillator strength are more important. PMID- 19873981 TI - Discovery of 2-{4-[(3S)-piperidin-3-yl]phenyl}-2H-indazole-7-carboxamide (MK 4827): a novel oral poly(ADP-ribose)polymerase (PARP) inhibitor efficacious in BRCA-1 and -2 mutant tumors. AB - We disclose the development of a novel series of 2-phenyl-2H-indazole-7 carboxamides as poly(ADP-ribose)polymerase (PARP) 1 and 2 inhibitors. This series was optimized to improve enzyme and cellular activity, and the resulting PARP inhibitors display antiproliferation activities against BRCA-1 and BRCA-2 deficient cancer cells, with high selectivity over BRCA proficient cells. Extrahepatic oxidation by CYP450 1A1 and 1A2 was identified as a metabolic concern, and strategies to improve pharmacokinetic properties are reported. These efforts culminated in the identification of 2-{4-[(3S)-piperidin-3-yl]phenyl}-2H indazole-7-carboxamide 56 (MK-4827), which displays good pharmacokinetic properties and is currently in phase I clinical trials. This compound displays excellent PARP 1 and 2 inhibition with IC(50) = 3.8 and 2.1 nM, respectively, and in a whole cell assay, it inhibited PARP activity with EC(50) = 4 nM and inhibited proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC(50) in the 10-100 nM range. Compound 56 was well tolerated in vivo and demonstrated efficacy as a single agent in a xenograft model of BRCA-1 deficient cancer. PMID- 19873982 TI - Novel pentacyclic seco-prezizaane-type sesquiterpenoids with neurotrophic properties from Illicium jiadifengpi. AB - Three novel seco-prezizaane-type sesquiterpenoids, jiadifenolide (1), jiadifenoxolane A (2), and jiadifenoxolane B (3), were isolated from the pericarps of Illicium jiadifengpi. Their pentacyclic cage structures were determined by 2D-NMR methods, chemical conversion, and single-crystal X-ray analysis. Compounds 1 and 2 strongly promote neurite outgrowth in primary cultured rat cortical neurons at concentrations ranging from 0.01 to 10 muM. PMID- 19873983 TI - Total synthesis of (-)-huperzine A. AB - The total synthesis of (-)-huperzine A was accomplished in 23 steps from a commercially available anhydride. Our synthetic route features a facile construction of the bicyclo[3.3.1] skeleton equipped with proper functionalities to introduce the remaining substructures. PMID- 19873984 TI - Symmetric macrocycles by a Prins dimerization and macrocyclization strategy. AB - A tandem dimerization/macrocyclization reaction utilizing the Prins cyclization has been developed. This reaction develops molecular complexity through the formation of highly substituted dimeric tetrahydropyran macrocycles. Mild conditions utilizing rhenium(VII) catalysts were explored for aromatic substrates, while harsher Lewis acidic conditions were used for aliphatic substrates. Both aldehydes and acetals are shown to be viable substrates for this reaction. PMID- 19873985 TI - Catalytic asymmetric three-component Mannich-type reaction of alkenyl trichloroacetates. AB - A catalytic enantioselective three-component Mannich-type reaction of alkenyl trichloroacetates, ethyl glyoxalate, and aniline derivatives was achieved using an (S)-BINOL-derived chiral tin dibromide possessing a 4-trifluoromethylphenyl group at the 3- and 3'-positions as the chiral precatalyst in the presence of sodium ethoxide, sodium iodide, and ethanol. Optically active beta-amino ketones with up to 98% ee were syn-selectively obtained in high yields even from imines possessing a polar amino group under the influence of the in situ generated chiral tin bromide ethoxide. PMID- 19873986 TI - Monodisperse upconverting nanocrystals by microwave-assisted synthesis. AB - Upconverting nanocrystals have a tremendous potential for applications in fields such as bioanalysis, medical therapy, or display technologies. However, a prerequisite for many applications is the availability of small, monodisperse, and highly luminescent nanocrystals. Here we show, that a microwave-assisted synthesis approach allows for the synthesis of such monodisperse and luminescent upconverting nanocrystals within 5 min in a closed reaction vessel. Even though the same reactants and solvents as with classical conductive heating reactions were used, microwave-assisted synthesis resulted in differently sized and shaped particles and provided superior reaction control. The nucleation and growth mechanism follows a La Mer scheme and can be controlled extremely accurately. It is expected that the fundamental principles of this synthesis approach can be applied to many other types of nanocrystals as well. PMID- 19873987 TI - Palladium(II) acetate catalyzed tandem cycloisomerization and oxidation of arylvinylcyclopropenes using p-benzoquinone as oxidant and pro-nucleophile. AB - Catalyzed by Pd(II)/p-BQ, a tandem cycloisomerization and oxidation of arylvinylcyclopropenes took place smoothly to produce methyleneindene derivatives stereoselectively in moderate to excellent yields, affording an unusual example of solo addition by p-hydroquinone generated by oxidation of Pd(0) to Pd(II) along with the formation of a new C-O bond. PMID- 19873988 TI - Got TiO2 nanotubes? Lithium ion intercalation can boost their photoelectrochemical performance. AB - Cations such as H(+) and Li(+) are intercalated into TiO(2) nanotube arrays by subjecting them to short-term electrochemical pulses at controlled potentials (< 1.0 V vs Ag/AgCl). The intercalation of these small cations has a profound effect toward enhancing photocurrent generation under UV light irradiation. A nearly three-fold increase in the photoconversion efficiency (IPCE) was observed upon intercalation of Li(+) ions into TiO(2) nanotube arrays. The intercalation process is visualized by the color change from gray to blue. Spectroelectrochemical measurements were carried out to monitor the absorption changes at different applied potentials. The analysis of the V(oc) decay following termination of UV light shows a significant decrease in the rate of recombination of accumulated electrons upon Li(+) ion intercalation. PMID- 19873989 TI - Studies on electrophilic reaction of tertiary 2,3-allenols with NBS in H2O or aqueous MeCN: an efficient selective synthesis of 2-bromoallylic ketones, 1,2 allenyl ketones, or 3-bromo-2,5-dihydrofurans. AB - Previously, we observed that the electrophilic reaction of 2,3-allenols with X(+) (X = Br, I) affords 3-halo-2-alkenals or 2-halo-2-alkenyl ketones in aqueous MeCN (MeCN/H(2)O = 15:1). However, the reaction of tertiary 2,3-allenols with NBS under these reaction conditions affords a mixture of rearrangement products (aldehydes or ketones) together with 1-bromovinyl epoxides in a low selectivity. Due to the synthetic potential of 2-haloallylic ketones, we decided to explore this reaction further. After screening, we observed that the electrophilic reaction of terminal tertiary 2,3-allenols with NBS in water affords 2 bromoallylic ketones highly selectively in up to 97% yields via a sequential electrophilic interaction of Br(+) with the allene moiety to form a possible three-membered bromonium intermediate with the more substituted C=C bond, which would be followed by 1,2-aryl or 1,2-alkyl shift to open the strained three membered ring and proton elimination to form the carbonyl functionality. When both R(1) and R(2) (the substituents on the carbon atom connected to the hydroxyl groups) are alkyl groups, one of these two groups is migrated; with 1,2 propadienyl cycloalkanols, a ring expansion reaction was observed; with R(1) being an aryl group, R(1) would be transferred exclusively to form the 2 bromoallylic ketones. Interestingly, these 2-bromo-1-aryl-2-propenyl ketones may easily be converted into 1,2-allenyl ketones after column chromatography on silica gel pre-eluented with 10 drops of Et(3)N; when there is at least an alkyl substituent on the 4-position of the tertiary 2,3-allenols, their electrophilic reaction with NBS in CH(3)CN/H(2)O = 15/1 or H(2)O, under the same reaction conditions as above, affords 3-bromo-2,5-dihydrofurans in 61-84% yields, indicating that the electronic effect and the steric effect of the two C=C bonds determine the reaction pathway, i.e., the Br(+) interacts with the C=C bond at the 3-position. PMID- 19873990 TI - Alotaketals A and B, sesterterpenoids from the marine sponge Hamigera species that activate the cAMP cell signaling pathway. AB - The new sesterterpenoids alotaketals A (1) and B (2) have been isolated from extracts of the marine sponge Hamigera sp. collected in Papua New Guinea. Their chemical structures were elucidated by analysis of spectroscopic data. Alotaketals A and B have the unprecedented alotane carbon skeleton, and they activate the cAMP cell signaling pathway with EC(50)'s of 18 and 240 nM, respectively. PMID- 19873991 TI - Formal total synthesis of (-)-saliniketals. AB - A highly stereoselective formal total synthesis of the ornithine decarboxylase inhibitors (-)-saliniketals A and B is described. The salient features of the synthesis are the utilization of a desymmetrization technique to create six contiguous chiral centers from a single bicyclic precursor as well as substrate controlled Grignard reaction, intramolecular Wacker-type oxidation, and antialdol reaction following Pirrung-Heathcock conditions. PMID- 19873992 TI - Online coupling of electrochemical reactions with liquid sample desorption electrospray ionization-mass spectrometry. AB - The combination of electrochemistry (EC) and mass spectrometry (MS) is a powerful analytical tool to study redox reactions. This work reports the online coupling of a thin-layer electrochemical flow cell with liquid sample desorption electrospray ionization mass spectrometry (DESI-MS) and its applications in investigating various electrochemical reactions of biological molecules such as oxidative formation and reductive cleavage of disulfide bonds and online derivatization of peptides/proteins. As a result of the direct sampling nature of DESI, several useful features of such a coupling have been found, including simple instrumentation, fast response time (e.g., 3.6 s in the case of dopamine oxidation), freedom to choose a favorable ionization mode of DESI or traditional electrolysis solvent systems, and the absence of background signal possibly resulting from ionization when the cell is off (e.g., in the case of dopamine oxidation). More importantly, with the use of this new coupling apparatus, three disulfide bonds of insulin were fully cleaved by electrolytic reduction and both the A and B chains of the protein were successfully detected online by DESI-MS. In addition, online tagging of free cysteine residues of peptides/proteins employing electrogenerated dopamine o-quinone can be performed. These revealed characteristics of the coupling along with examined electrochemical reactions suggest that EC/DESI-MS has good potential in bioanalysis. PMID- 19873994 TI - Efficient synthesis of 3-arylphthalides using palladium-catalyzed arylation of aldehydes with organoboronic acids. AB - The synthesis of 3-arylphthalides via palladium-catalyzed arylation of aldehydes with organoboronic acids was achieved using the thioether-imidazolinium carbene ligand in good to excellent yields and was carried out using 1.0 mol % of the catalyst with high substrate tolerance. PMID- 19873993 TI - Identification of aspartic and isoaspartic acid residues in amyloid beta peptides, including Abeta1-42, using electron-ion reactions. AB - Amyloid beta peptides are the major components of the vascular and plaque amyloid filaments in individuals with Alzheimer's disease (AD). Although it is still unclear what initiates the disease, isomerization of aspartic acid residues in Abeta peptides is directly related to the pathology of AD. The detection of isomerization products is analytically challenging, due to their similar chemical properties and identical molecular mass. Different methods have been applied to differentiate and quantify the isomers, including immunology, chromatography, and mass spectrometry. Typically, those methods require comparative analysis with the standard peptides and involve many sample preparation steps. To understand the role of Abeta isomerization in AD progression, a fast, simple, accurate, and reproducible method is necessary. In this work, electron capture dissociation (ECD) Fourier-transform ion cyclotron resonance mass spectrometry (FTICR MS) was applied to detect isomerization in Abeta peptides. ECD generated diagnostic fragment ions for the two isomers of Abeta17-28, [M + 2H - 60]+* and z6*-44 when aspartic acid was present and z6*-57 when isoaspartic acid was present. Additionally, the z(n)-57 diagnostic ion was also observed in the electron ionization dissociation (EID) spectra of the modified Abeta17-28 fragment. ECD was further applied toward Abeta1-40 and Abeta1-42. The diagnostic ion c6 + 57 was observed in the ECD spectra of the Abeta1-42 peptide, demonstrating isomerization at residue 7. In conclusion, both ECD and EID can clearly determine the presence and the position of isoaspartic acid residues in amyloid beta peptides. The next step, therefore, is to apply this method to analyze samples of Alzheimer's patients and healthy individuals in order to generate a better understanding of the disease. PMID- 19873995 TI - Conical intersection is responsible for the fluorescence disappearance below 365 nm in cyclopropanone. AB - The photodissociation dynamics of cyclopropanone was explored with the complete active space self-consistent field (CASSCF) calculations and ab initio nonadiabatic molecular dynamics simulations. The related minima, transition state (TS) and minimum-energy conical intersections (MECIs) were obtained as well as energetics. In the static CASSCF calculations, one MECI was found to be responsible for the fluorescence disappearance below 365 nm because the ultrafast internal conversion (IC) via this MECI deprived the opportunity of the fluorescence emission. Further evidence of this ultrafast IC event came from the subsequent ab initio nonadiabatic molecular dynamics simulations. PMID- 19873997 TI - [N3MN5]q: a type of low-lying sandwich-like isomer on [N8M]q hypersurface with (M, q) = (Ni, 0), (Co, -1), and (Fe, -2). AB - Recently, design and assembly of small, high-energy-density, all-nitrogen units into more complex sandwich-like forms have received growing attention. In this paper, we report a type of heterodecked sandwich-like structures [N(3)MN(5)](q) containing two odd-membered all-nitrogen rings (N(3) and N(5)) on the hypersurface of [N(8)M](q) [(M, q) = (Ni, 0), (Co, -1), (Fe, -2)]. At the B3LYP/6 311+G(d) level, the new isomers are energetically more stable than the previously reported homodecked sandwich-like isomers [N(4)MN(4)](q) based on the even membered all-nitrogen ring N(4)(2-). In particular, the eta(3)-eta(2) (eta(3) eta(1)) isomers of [N(3)MN(5)](q) [(M, q) = (Ni, 0), (Co, -1), (Fe, -2)] possess considerable kinetic stability for laboratory characterization. The bond length and natural charge analysis of [N(3)MN(5)](q) [(M, q) = (Ni, 0), (Co, -1), (Fe, 2)] indicate that each complex possesses the smallest triplet all-nitrogen ring (3)N(3)(-). The unique stability of the presently designed heterodecked sandwich like complexes await future laboratory investigations. PMID- 19873996 TI - Amide or amine: determining the origin of the 3300 cm(-1) NH mode in protein SFG spectra using 15N isotope labels. AB - Sum frequency generation (SFG) vibrational spectroscopy has been employed in biomaterials research and protein adsorption studies with growing success in recent years. A number of studies focusing on understanding SFG spectra of proteins and peptides at different interfaces have laid the foundation for future, more complex studies. In many cases, a strong NH mode near 3300 cm(-1) is observed in the SFG spectra, but the relationship of this mode to the peptide structure is uncertain, since it has been assigned to either a backbone amide mode or a side chain related amine resonance. A thorough understanding of the SFG spectra of these first model systems is an important first step for future experiments. To clarify the origin of the NH SFG mode, we studied (15)N isotopically labeled 14-amino acid amphiphilic model peptides composed of lysine (K) and leucine (L) in an alpha-helical secondary structure (LKalpha14) that were adsorbed onto charged surfaces in situ at the solid-liquid interface. (15)N substitution at the terminal amine group of the lysine side chains resulted in a red-shift of the NH mode of 9 cm(-1) on SiO(2) and 13 cm(-1) on CaF(2). This clearly shows the 3300 cm(-1) NH feature is associated with side chain NH stretches and not with backbone amide modes. PMID- 19873998 TI - Subnanometer CdS clusters self-confined in MFI-type zeolite nanoparticles and thin films. AB - One-step colloidal synthesis of subnanometer CdS clusters in hydrophobic MFI-type zeolite crystals in the presence of 3-mercaptopropyl-trimethoxysilane (MPS), cadmium precursor, and tetrapropylammonium hydroxide (TPAOH) is performed. MPS is used as the bifunctional agent, as it hydrolyzes fast, cross-links with the silica framework, and provides thiol groups to anchor Cd(2+), and subsequently forms CdS clusters. The MFI crystals with the thiol groups not only function as a nanochamber for the formation of CdS but also prevent further moisture-induced agglomeration of the clusters. Direct evidence for the presence of asymmetric shaped subnanometer CdS clusters aligned in the channels of MFI crystals stabilized in suspensions and films is provided by high resolution transmission electron microscopy (HRTEM), grazing incidence X-ray diffraction (GI-XRD), and photoluminescence spectra (emission < 350 nm). The CdS clusters are stable for months in colloidal suspensions and films without any particular precaution against water. The hydrophobicity of the MFI zeolite and the presence of the organic template in the channels favor the stabilization of small CdS clusters, which are available for further applications. PMID- 19873999 TI - Biolabeling with 2,4-dichlorophenoxyacetic acid derivatives: the 2,4-D tag. AB - Many bioanalytic and diagnostic procedures rely on labels with which the molecule of interest can be tracked in or discriminated from accompanying like substances. Herein, we describe a new labeling and detection system based on derivatives of 2,4-dichlorophenoxyacetic acid (2,4-D) and anti-2,4-D antibodies. The 2,4-D system is highly sensitive with a K(D) of 7 x 10(-11) M for the hapten-antibody pair, can be used on a large variety of biomolecules such as proteins, peptides, carbohydrates, and nucleic acids, is not hampered by endogenous backgrounds because 2,4-D is a xenobiotic, and is robust because 2,4-D is a very stable compound that withstands the conditions of most reactions usually performed on biomolecules. With this unique blend of properties, the 2,4-D system compares favorably with its rivals digoxigenin (DIG)/anti-DIG and biotin/(strept)avidin and provides an interesting and powerful tool in biomolecular labeling. PMID- 19874000 TI - Mixed monolayers on gold nanoparticle labels for multiplexed surface-enhanced Raman scattering based immunoassays. AB - This paper describes a new approach, based on self-assembled mixed monolayers, to the design and preparation of extrinsic Raman labels (ERLs). ERLs function as spectroscopic tags for the readout of sandwich-type immunoassays using surface enhanced Raman scattering (SERS). They are created by coating gold nanoparticles with Raman reporter molecules and antibodies specific for the target analyte. Mixed-monolayer ERLs are formed by covering gold nanoparticles with a mixture of two different thiolates. One thiolate serves to covalently bind antibodies to the particles, imparting biospecificity to the ERLs, while the other thiolate produces a strong Raman signal. Mixed-monolayer ERLs can be prepared in a few relatively simple steps using readily available materials. The SERS intensity of each type of ERL can be tuned to match other ERLs by adjusting the mixed monolayer composition, greatly facilitating the generation of sets of ERLs for multiplexed applications. The work herein not only describes the new pathway for ERL production, but also demonstrates the simultaneous qualitative and quantitative multiplexed detection using a set of four mixed-monolayer ERLs. PMID- 19874001 TI - Simultaneous determination of twelve tetrahydrocorticosteroid glucuronides in human urine by liquid chromatography/electrospray ionization-linear ion trap mass spectrometry. AB - A liquid chromatography/electrospray ionization (ESI)-mass spectrometry (MS) method for the direct determination of 12 tetrahydrocorticosteroid glucuronides in human urine has been developed. The analytes were 3- and 21-monoglucuronides of tetrahydrocortisol, tetrahydrocortisone, tetrahydro-11-deoxycortisol, and their 5alpha-stereoisomers. The mass spectrometric behaviors of these glucuronides in negative-ion ESI-MS/MS revealed the production of intense, structure-specific product ions within the same group of glucuronides. Regioisomeric glucuronides could be distinguished by collision-induced dissociation and tandem mass spectrometry. Using a linear ion trap instrument operating in the negative-ion mode and by monitoring the transition ions of [M - H](-) --> [M - H - CH(2)O](-) for 3-monoglucuronides and [M - H](-) --> [M - H - CH(2)OG](-) for 21-monoglucuronides, a sensitive and specific assay was developed. Initial steps in the assay were a simple solid-phase extraction and the addition of [9,12,12,21,21-d(5)]-tetrahydrocortisone-3-glucuronide (prepared by enzyme-assisted synthesis) as an internal standard. The method was applied to determine the 12 tetrahydrocoticosteroid glucuronides in urine from healthy subjects and from patients with excessive cortisol production. The method described here appears to be useful for clinical and biochemical studies. PMID- 19874002 TI - Enzymatic/chemical release of O-glycans allowing MS analysis at high sensitivity. AB - As the role of O-linked oligosaccharides have been demonstrated to be increasingly important in numerous medical conditions, it is imperative to develop new techniques allowing their analysis at high sensitivity. While mass spectrometry (MS) provides adequate measurements of important O-linked oligosaccharides glycans and their profiles, the release from glycoproteins has not been sufficiently addressed for the needs of biomedical applications. This work describes a new strategy, involving the combination of a complete enzymatic degradation with a chemical release during the solid-phase permethylation of O linked oligosaccharides. The analytical data implicate highly effective cleavage from the serine and threonine (but not arginine) residues, during permethylation. Tandem MS analyses confirmed these observations for model glycoproteins. Comparative measurements through isotopic labeling MS show this approach to be vastly superior over the previously used cleavage procedures. PMID- 19874003 TI - Oxidized mesoporous silicon microparticles for improved oral delivery of poorly soluble drugs. AB - Surface functionalized mesoporous silicon (pSi) microparticles are reported as a solid dispersion carrier for improving dissolution and enhancing the orally administered pharmacokinetics (fasted rat model) of indomethacin (IMC), employed as a model poorly soluble BCS type II drug. IMC was loaded via immersion/solvent evaporation onto the thermally oxidized pSi particles, which provide a stable hydrophilic matrix with a nanoporous structure. The solid state properties of IMC loaded pSi were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, differential scanning calorimetry and thermogravimetric analysis. IMC molecules are encapsulated in a noncrystalline state due to geometric confinement in the nanopores; stability of the noncrystalline state has been demonstrated for several months under accelerated storage conditions. The pSi carrier facilitates accelerated immediate release of IMC and enhanced oral delivery performance in comparison with crystalline indomethacin and Indocid i.e. a 4-times reduction on T(max), a 200% increase on C(max) and a significant increase in bioavailability. The in vitro-in vivo correlation is discussed based on the noncompartment model and gives insight into the delivery mechanism for the pSi carrier. PMID- 19874005 TI - Investigation of the effect of oxy bridging groups in dinuclear Zn(II) complexes that catalyze the cleavage of a simple phosphate diester RNA analogue. AB - Two sets of dinuclear Zn(II) complexes were prepared to determine the effect of the presence of oxyanionic bridging groups between the metal centers on the catalytic activity toward the methanolysis of the RNA analogue 2-hydroxypropyl-4 nitrophenyl phosphate (HPNPP, 2). The Zn(II)2 complexes of bis(di-(2 pyridylmethyl)amino)-m-xylene (6) and 2,6-bis(di-(2-pyridylmethyl)amino)-4 methylphenol (7) were compared to assess the effect of a bridging phenoxide ligand, while the Zn(II)2 complex of 1,3-bis-N1-(1,5,9-triazacyclododecyl)-propan 2-ol (8) was prepared to determine the effect of the 2-propoxy group compared to the previously studied complex of 1,3-bis-N1-(1,5,9-triazacyclododecyl)-propane (4). Detailed kinetic studies of the cleavage of 2 including k(obs) vs [catalyst] plots and (s)(s)pH-rate profiles were performed for each system along with potentiometric titration experiments to determine the acid dissociation constants for the catalytically relevant groups. The results show that inclusion of the phenoxy bridging group in 7:Zn(II)2 reduces the second-order catalytic rate constant (k2(cat)) for cleavage of 2 by a factor of 160 relative to that of 6:Zn(II)2, while the incorporation of a propoxy group in 8:Zn(II)2 reduces its efficacy by 3.7 x 10(4) times relative to 4:Zn(II)2. Energetics calculations reveal that 6:Zn(II)2 offers a 3.7 kcal/mol greater stabilization of the reaction transition state for the cleavage of 2 than does 7:Zn(II)2 and that 4:Zn(II)2 affords 6.5 kcal/mol greater transition state stabilization than does 8:Zn(II)2. The analyses show that the reduction in the transition state stabilization experienced with the complexes having permanently bridging oxyanion groups stems almost entirely from a weaker binding of the phosphate and catalyst, and a reduced catalytic rate constant. These results indicate that the presence of a bridging oxyanion ligand between the metal centers, a common structural element required for the successful formation of many small molecule dinuclear catalysts that show cooperative activity in water, significantly impairs the catalytic efficiency for cleavage of 2. PMID- 19874004 TI - The drug transporter-metabolism alliance: uncovering and defining the interplay. AB - Two decades ago the importance of transporter-enzyme interplay and its effects on drug bioavailability and hepatic disposition were first recognized. Here we review the history of uncovering and defining this interplay with a primary emphasis on studies from our laboratory. We review the early 1990s oral bioavailability studies that found that the highly lipophilic, poorly water soluble cyclosporine formulation on the market at that time did not have an absorption problem, but rather a gut metabolism problem. This led to studies of the interactive nature of CYP3A and P-glycoprotein in the intestine, and investigations of this interplay using cellular systems and isolated perfused rat organ studies. Studies investigating uptake transporter-enzyme interactions using cellular, perfused rat liver and intact rats are reviewed, followed by the human transporter-enzyme interaction studies. Work characterizing the rate limiting processes in the drug transporter-metabolism alliance is then addressed, ending with a review of areas of the interplay that require further studies and analysis. PMID- 19874006 TI - Controlled self-assembly of quantum dot-block copolymer colloids in multiphase microfluidic reactors. AB - The controlled self-assembly of large compound quantum dot micelles (QDCMs), consisting of constituents of polymer-stabilized quantum dots (QDs) and amphiphilic polystyrene-b-poly(acrylic acid) stabilizing chains, in gas-liquid segmented microfluidic reactors is demonstrated. Self-assembly is initiated by fast mixing of water with the polymer constituents via chaotic advection, as liquid plugs containing reactants move through a sinusoidal mixing channel. The resulting QDCMs are then processed within a postformation channel, where circulating flow patterns develop within the liquid plugs, followed by off-chip quenching and analysis by transmission electron microscopy (TEM). Particle processing via circulating flow is found to involve a combination of particle growth via collision-induced coalescence and shear-induced particle breakup. The final mean QDCM sizes represent kinetic states arising from the competition between these two mechanisms, depending on tunable chemical and flow parameters. A systematic investigation of the experimental variables that influence particle size and polydispersity, including water concentration, flow rate, and the gas-to liquid flow ratio, is conducted, demonstrating tunability of QDCM sizes in the range of approximately 40-140 nm. The importance of shear-induced particle breakup in the limit of high shear is illustrated by a common minimum particle size, 41 +/- 1 nm, which is achieved for all water contents by increasing the total flow rate to sufficiently high values. PMID- 19874007 TI - Efficient site-specific radiolabeling of a modified C2A domain of synaptotagmin I with [99mTc(CO)3]+: a new radiopharmaceutical for imaging cell death. AB - We describe the design and synthesis of a new Tc-99m labeled bioconjugate for cell-death imaging, based on C2A, the phosphatidylserine (PS)-binding domain of rat synaptotagmin I. Since several lysine residues in this protein are critical for PS binding, we engineered a new protein, C2AcH, to include the C-terminal sequence CKLAAALEHHHHHH, incorporating a free cysteine (for site-specific covalent modification) and a hexahistidine tag (for site-specific radiolabeling with [99mTc(CO)3(OH2)3]+). We also engineered a second derivative, C2Ac, in which the C-terminal sequence included only the C-terminal cysteine. These proteins were characterized by electrospray mass spectrometry, SDS/PAGE, and size exclusion chromatography and radiolabeled with [99mTc(CO)3(OH2)3]+. Conjugates of the proteins with the rhenium analogue [Re(CO)3(OH2)3]+ were also synthesized. Site-specific labeling was confirmed by performing a tryptic digest of rhenium tricarbonyl-labeled C2AcH, and only peptides containing the His-tag contained the [Re(CO)3]+. The labeled proteins were tested for binding to red blood cells (RBC) with exposed PS in a calcium dependent manner. Labeling 100 microg of C2AcH with [99mTc(CO)3(OH2)3]+ at 37 degrees C for 30 min gave a radiochemical yield of > 96%. However, C2AcH that had first been conjugated with fluorescein maleimide or iodoacetamide via the Cys residue gave only 50% and 83% radiochemical yield, respectively, after incubation for 30 min at 37 degrees C. Serum stability results indicated that >95% of radiolabeled C2AcH remained stable for at least 18 h at 37 degrees C. Site-specifically labeled C2AcH exhibited calcium-dependent binding to the PS on the RBC, whereas a nonspecifically modified derivative, C2AcH-B, in which lysines had been modified with benzyloxycarbonyloxy, did not. We conclude that (i) the combination of Cys and a His-tag greatly enhances the rate and efficiency of labeling with [99mTc(CO)3(OH2)3]+ compared to either the His-tag or the Cys alone, and this sequence deserves further evaluation as a radiolabeling tag; (ii) non-site-specific modification of C2A via lysine residues impairs target binding affinity; (iii) 99mTc-C2AcH has excellent radiolabeling, stability and PS binding characteristics and warrants in vivo evaluation as a cell-death imaging agent. PMID- 19874008 TI - Molecular conductors based on the mixed-valence polyoxometalates [SMo12O40]n- (n = 3 and 4) and the organic donors bis(ethylenedithio)tetrathiafulvalene and bis(ethylenedithio)tetraselenafulvalene. AB - The synthesis, crystal structure, and physical characterization of two new radical salts formed by the organic donors bis(ethylenedithio)tetrathiafulvalene (ET) and bis(ethylenediseleno)tetrathiafulvalene (BETS) and the Keggin polyoxometalate (POM) [SMo(12)O(40)](n-) are reported. The salts isolated are ET(8)[SMo(12)O(40)] x 10 H(2)O (1) (crystal data: (1) monoclinic, space group I2/m with a = 13.9300(10) A, b = 43.467(3) A, c = 13.9929(13) A, beta = 107.979(6) degrees, V = 8058.9(11) A(3), Z = 2) and BETS(8)[SMo(12)O(40)] x 10 H(2)O (2) (crystal data: monoclinic, space group I2/m with a = 14.0878(2) A, b = 44.1010(6) A, c = 14.0930(2) A, beta = 106.739(3) degrees, V = 8384.8 A(3), Z = 2). Both compounds are isostructural and consist of alternating layers of the organic donors (with an alpha or theta(42+40) packing mode) and POM anions. The structural data, as well as the magnetic susceptibility, ESR measurements, and band structure calculations, indicate that the Keggin POMs have been reduced by one electron in 1 and by two electrons in 2, leading to the POMs [SMo(12)O(40)](3 ) and [SMo(12)O(40)](4-) in 1 and 2, respectively. At ambient pressure 1 is a classical semiconductor with a room temperature conductivity of about 1 S cm(-1) and an activation energy of about 130 meV. Salt 2 also exhibits an activated behavior although it does not follow a classical semiconducting regime. The conductivity of 2 under applied pressure shows an enhanced conductivity, in agreement with the analysis of the electronic structure, although no metallic behavior is detected below about 10 kbar. PMID- 19874009 TI - Surface dipole layer potential induced ir absorption enhancement in n-alkanethiol SAMs on GaAs(001). AB - The work function of n-alkanethiol self-assembled monolayers (SAMs) prepared on the GaAs(001) surface was measured using the Kelvin probe technique yielding the SAM 2D dipole layer potential (DLP). Direct n-dependent proportionality between the DLP values and the C-H stretching mode infrared (IR) absorption intensities was observed, which supports a correspondence of reported IR enhancements with the electrostatic properties of the interface. X-ray photoelectron spectroscopy is also used to verify the work function measurements. In addition, the principal components of the refractive index tensor are shown to be n-invariant in the ordered SAM phase. Our results suggest that a local field correction to the transition dipole moment accounts for the observed increase in IR activity through an increase to the electronic polarizability. PMID- 19874010 TI - Amine-bearing mesoporous silica for CO(2) and H(2)S removal from natural gas and biogas. AB - Triamine-grafted pore-expanded mesoporous silica (TRI-PE-MCM-41) exhibited high CO(2) and H(2)S adsorption capacity as well as high selectivity toward acid gases versus CH(4). Unlike physical adsorbents such as zeolites and activated carbons, the presence of moisture in the feed enhanced the CO(2) removal capability of TRI PE-MCM-41 without altering its H(2)S adsorption capacity. Thus, depending on the feed composition, CO(2) and H(2)S may be removed over TRI-PE-MCM-41 simultaneously or sequentially. These findings are suitable for acid gas separation from CH(4)-containing mixtures such as natural gas and biogas. PMID- 19874011 TI - Reactive formation of zircon inclusion pigments by deposition and subsequent annealing of a zirconia and silica double shell. AB - A novel general method for coating particles with a complex oxide was described. Zirconia precursor and silica layers with careful control of film thickness were coated separately onto hematite particles in corresponding solutions. A zircon shell was subsequently obtained by heat treatment at 800 degrees C for 3 h using LiF as a mineralizer. The as-prepared zircon-occluded hematite pigment gave a pink color to the glazed sample after annealing at 1120 degrees C. The current research suggests that various chromophoric particles can be encapsulated with zircon to prepare ceramic pigments for high-temperature use. PMID- 19874012 TI - Novel self-assemblies of oppositely charged polyelectrolytes and surfactants in the presence of neutral polymer. AB - In this Letter, the effect of addition of poly(ethylene oxide) (PEO) on the nature of the self-assemblies of sodium dodecyl sulfate (SDS) and branched poly(ethyleneimine) (PEI) is investigated. We demonstrate that the neutral polymer adsorbs onto the surface of the polyelectrolyte/surfactant nanoparticles, which may result in sterically stabilized colloidal dispersions of the nanoparticles with hydrophobic core and hydrophilic corona. The kinetic stability is maintained even at high ionic strengths, where the charge stabilization of the PEI/SDS dispersions is inefficient. These results might be exploited to improve the efficiency of those formulations, which contain oppositely charged macromolecules and amphiphiles. PMID- 19874013 TI - Gold nanoparticle enlargement coupled with fluorescence quenching for highly sensitive detection of analytes. AB - We report a versatile and facile route for highly sensitive detection of analytes through coupling the enlargement of gold nanoparticles with fluorescence quenching. The fluorescence intensity of dye molecules (e.g., fluorescein or rhodamine B) significantly decreased with the increasing concentration of reducing agents, such as hydrogen peroxide and hydroquinone. The sensitivity for the detection of reducing agents was much higher than that of other methods based on the absorbance measurement of enlarged gold nanoparticles or quantum-dot enzyme hybridization. We could successfully detect acetylthiocholine with the detection limit of several nanomolar concentration using an enzymatic reaction by acetylcholine esterase, a key route for the detection of toxic organophosphate compounds. The fluorescence quenching approach described in this report requires only a simple addition of fluorescence dye to the reaction solution without any chemical modification. The strategy of fluorescence quenching coupled with nanoparticle growth would provide a new horizon for the development of highly sensitive optical biosensors. PMID- 19874014 TI - Laser photolysis of dye-sensitized nanocapsules occurs via a photothermal pathway. AB - Light-addressable nanocapsules offer a powerful method for delivering spatiotemporally precise signals to cells. Thus far, the mechanism involved in the photolysis of nanocapsules has been opaque. This paper presents experimental evidence that rules out a photochemical pathway in favor of a photothermal mechanism in the far-red photolysis of dye-sensitized, lipid-vesicle based nanocapsules. Photolysis efficiency was unaffected by the presence of radical inhibitors, and mass spectrometry measurements confirmed that the photolytic process did not produce dye radicals. Measurements of dye quantum yield in the lipid membrane showed an inverse correlation between quantum yield of the dye and photolysis efficiency of the vesicle. The result is consistent with the notion that a decrease in quantum yield translates into more vibrational relaxation and thermal motion of the dye molecules in the membrane and thus more efficient photothermal disruption of the vesicle. Furthermore, we observed that the decrease in quantum yield and increase in photolysis efficiency was caused by the formation of raftlike domains that clustered the dye molecules into concentrated regions. On the basis of this information, we were able to design new nanocapsules using ternary mixtures of lipid and cholesterol that promoted the formation of raft domains and dye clustering. These nanocapsules showed improved photolysis efficiency over the best results we obtained previously. PMID- 19874015 TI - Giardia telomeric sequence d(TAGGG)4 forms two intramolecular G-quadruplexes in K+ solution: effect of loop length and sequence on the folding topology. AB - Recently, it has been shown that in K(+) solution the human telomeric sequence d[TAGGG(TTAGGG)(3)] forms a (3 + 1) intramolecular G-quadruplex, while the Bombyx mori telomeric sequence d[TAGG(TTAGG)(3)], which differs from the human counterpart only by one G deletion in each repeat, forms a chair-type intramolecular G-quadruplex, indicating an effect of G-tract length on the folding topology of G-quadruplexes. To explore the effect of loop length and sequence on the folding topology of G-quadruplexes, here we examine the structure of the four-repeat Giardia telomeric sequence d[TAGGG(TAGGG)(3)], which differs from the human counterpart only by one T deletion within the non-G linker in each repeat. We show by NMR that this sequence forms two different intramolecular G quadruplexes in K(+) solution. The first one is a novel basket-type antiparallel stranded G-quadruplex containing two G-tetrads, a G x (A-G) triad, and two A x T base pairs; the three loops are consecutively edgewise-diagonal-edgewise. The second one is a propeller-type parallel-stranded G-quadruplex involving three G tetrads; the three loops are all double-chain-reversal. Recurrence of several structural elements in the observed structures suggests a "cut and paste" principle for the design and prediction of G-quadruplex topologies, for which different elements could be extracted from one G-quadruplex and inserted into another. PMID- 19874016 TI - A new porous reaction layer for developing addressable molecular libraries. AB - A new diblock copolymer-derived porous reaction layer for microelectrode arrays has been tested for its stability and its compatibility with both site-selective synthesis and electrochemical signaling experiments. The diblock copolymer consisted of a cinnamoyl-substituted polymethacrylate block for attachment to the surface of the array and a bromo-substituted polystyrene block for selective functionalization of the surface proximal to microelectrodes in the array. Site selective Suzuki, Heck, and Cu(I)-coupling reactions were all performed on the new reaction layer along with electrochemical impedance studies. PMID- 19874017 TI - Superbasicity of a bis-guanidino compound with a flexible linker: a theoretical and experimental study. AB - The bis-guanidino compound H(2)C{hpp}(2) (I; hppH = 1,3,4,6,7,8-hexahydro-2H pyrimido[1,2-a]pyrimidine) has been converted to the monocation [I-H](+) and isolated as the chloride and tetraphenylborate salts. Solution-state spectroscopic data do not differentiate the protonated guanidinium from the neutral guanidino group but suggest intramolecular "-N-H...N=" hydrogen bonding to form an eight-membered C(3)N(4)H heterocycle. Solid-state CPMAS (15)N NMR spectroscopy confirms protonation at one of the imine nitrogens, although line broadening is consistent with solid-state proton transfer between guanidine functionalities. X-ray diffraction data have been recorded over the temperature range 50-273 K. Examination of the carbon-nitrogen bond lengths suggests a degree of "partial protonation" of the neutral guanidino group at higher temperatures, with greater localization of the proton at one nitrogen position as the temperature is lowered. Difference electron density maps generated from high resolution X-ray diffraction studies at 110 K give the first direct experimental evidence for proton transfer in a poly(guanidino) system. Computational analysis of I and its conjugate acid [I-H](+) indicate strong cationic resonance stabilization of the guanidinium group, with the nonprotonated group also stabilized, albeit to a lesser extent. The maximum barrier to proton transfer calculated using the Boese-Martin for kinetics method was 2.8 kcal mol(-1), with hydrogen-bond compression evident in the transition state; addition of zero-point vibrational energy values leads to the conclusion that the proton transfer is barrierless, implying that the proton shuttles freely between the two nitrogen atoms. Calculations determining the gas-phase proton affinity and the pK(a) in acetonitrile both indicate that compound I should behave as a superbase. This has been confirmed by spectrophotometric titrations in MeCN using polyphosphazene references, which give an average pK(a) of 28.98 +/- 0.05. Triadic analysis indicates that the dominant term causing the high basicity is the relaxation energy. PMID- 19874018 TI - Excited-state dynamics of cytosine tautomers. AB - We report the relaxation dynamics of keto and enol or keto-imino cytosine, photoexcited in the wavelength range of 260-290 nm. Three transients with femtosecond to hundreds of picoseconds lifetimes are observed for the biologically relevant keto tautomer and are assigned to internal conversion and excited-state tautomerization. Only two transients with femtosecond and picosecond lifetimes are identified for the enol or keto-imino tautomer and are assigned to internal conversion processes. The results are discussed in the context of published ab initio theory. PMID- 19874019 TI - Dramatic improvement in catalyst loadings and molar ratios of coupling partners for Ni/Cr-mediated coupling reactions: heterobimetallic catalysts. AB - Two new ligands 1a,b are reported. Upon treatment with 1 equiv of NiCl(2) x (MeOCH(2))(2), 1a,b give the corresponding Ni complexes. X-ray analysis of 1a x NiCl(2) established that the NiCl(2) is selectively coordinated to the phenanthroline nitrogens. Ni/Cr heterobimetallic catalysts 1a,b x CrCl(2)/NiCl(2), prepared from 1a,b x NiCl(2), have been shown to behave exceptionally well in catalytic asymmetric Ni/Cr-mediated couplings, with highlights including the following: (1) 1-2 mol % catalyst is sufficient to complete the coupling; (2) only negligible amounts of the dimers, byproducts formed through the alkenyl Ni species, are observed; (3) the coupling goes to completion even with a 1:1 molar ratio of the coupling partners; and (4) the asymmetric induction is practically identical with that obtained from the coupling with the Cr catalysts prepared from (S)-sulfonamides 2a,b. The scope of the new Ni/Cr heterobimetallic catalysts was briefly studied using four additional aldehydes. The applicability of the new catalysts to polyfunctional substrates was demonstrated by two C-C bond formations chosen from the halichondrin/E7389 synthesis as examples. PMID- 19874020 TI - Sorption characteristics of atrazine and imazethapyr in soils of new zealand: importance of independently determined sorption data. AB - We investigated sorption characteristics of two commonly used herbicides, atrazine and imazethapyr, in 101 soils with allophanic and non-allophanic clays of New Zealand using the batch equilibration technique. Soil properties, such as organic carbon (OC) content, texture, pH, amount and type of clay, and cation exchange capacity (CEC), were tested against the sorption coefficients (Kd) of these herbicides. There was a wide variation in the sorption affinities of the soils, as the Kd values of atrazine and imazethapyr ranged from 0.7 to 52.1 and from 0.1 to 11.3 L kg(-1), respectively. For atrazine, the sorption affinities for the allophanic set of soils (mean Kd of 8.5 L kg(-1)) were greater than for the non-allophanic set of soils (mean Kd of 7.5 L kg(-1)). However, no effect of allophanic status was found for imazethapyr sorption (mean Kd of 0.82 and 0.76 L kg(-1) for allophanic and non-allophanic, respectively). None of the measured soil properties could alone explain adequately the sorption behavior of the herbicides. The variation of OC soil sorption coefficients, Koc, was also larger for atrazine (mean Koc of 126.9 L kg(-1)) than for imazethapyr (mean Koc of 13.2 L kg(-1)). The prediction equations for atrazine and imazethapyr developed overseas failed to provide the acceptable values of sorption coefficients for the soils of New Zealand. The study highlights the danger of using sorption coefficient data from the literature for practical assessments of the herbicide leaching in New Zealand soils. PMID- 19874021 TI - Gene expression profiling of metabolism-related genes between top round and loin muscle of Korean cattle (Hanwoo). AB - Using differential display reverse transcriptase polymerase chain reaction, we detected 11 differentially expressed genes between top round and loin muscle in Korean cattle (Hanwoo). In the loin muscle, the lightness (L*) value (P<0.01) and marbling fat content (P<0.01), which are important factors in determining meat quality, were higher than in top round muscle. Three of the 11 genes were validated as significant genes between two types of muscle by real-time polymerase chain reaction (P<0.05). To determine whether the three genes were associated with meat quality traits, a regression analysis was preformed. The result demonstrated that two genes (NADH dehydrogenase 2 and cytochrome oxidase III), which are involved in oxidative phosphorylation in mitochondria, were significantly correlated with marbling fat content in the loin muscle (P<0.01), while two genes were not significant with marbling fat content in top round muscle. No significant effects for two genes on other meat quality traits such as meat color (redness and yellowness value), Warner-Bratzler shear force, and water holding capacity were detected in this study. PMID- 19874022 TI - Preferential interactions of guanidinum ions with aromatic groups over aliphatic groups. AB - Small angle neutron scattering (SANS) and molecular dynamics (MD) simulations were used to characterize the long-range structuring (aggregation) of aqueous solutions of isopropanol (IPA) and pyridine and the effect on structuring of guanidinium chloride (GdmCl). These solutes serve as highly soluble analogs of the nonpolar aliphatic (IPA) and aromatic (pyridine) side chains of proteins. SANS data showed that isopropanol and pyridine both form clusters in water resulting from interaction between nonpolar groups of the solutes, with pyridine aggregation producing longer-range structuring than isopropanol in 3 m solutions. Addition of GdmCl at 3 m concentration considerably reduced pyridine aggregation but had no effect on isopropanol aggregation. MD simulations of these solutions support the conclusion that long-range structuring involves hydrophobic solute interactions and that Gdm(+) interacts with the planar pyridine group to suppress pyridine-pyridine interactions in solution. Hydrophobic interactions involving the aliphatic groups of isopropanol were unaffected by GdmCl, indicating that the planar and weakly hydrated Gdm(+) cation cannot make productive interactions with the highly curved or "lumpy" aliphatic groups of this solute. These observations support the conclusion that the effects of Gdm(+) ions on protein-stabilizing interactions involving aromatic amino acid side chains make significant contributions to the denaturant activity of GdmCl, whereas interactions with the "lumpy" aliphatic side chains are likely to be less important. PMID- 19874024 TI - Mechanisms of aqueous extraction of soybean oil. AB - Aqueous extraction processing (AEP) of soy is a promising green alternative to hexane extraction processing. To improve AEP oil yields, experiments were conducted to probe the mechanisms of oil release. Microscopy of extruded soy before and after extraction with and without protease indicated that unextracted oil is sequestered in an insoluble matrix of denatured protein and is released by proteolytic digestion of this matrix. In flour from flake, unextracted oil is contained as intact oil bodies in undisrupted cells, or as coalesced oil droplets too large to pass out of the disrupted cellular matrix. Our results suggest that emulsification is an important extraction mechanism that reduces the size of these droplets and increases yield. Protease and SDS were both successful in increasing extraction yields. We propose that this is because they disrupt a viscoelastic protein film at the droplet interface, facilitating droplet disruption. An extraction model based on oil droplet coalescence and the formation of a viscoelastic film was able to fit kinetic extraction data well. PMID- 19874023 TI - Total synthesis of platensimycin and related natural products. AB - Platensimycin is the flagship member of a new and growing class of antibiotics with promising antibacterial properties against drug-resistant bacteria. The total syntheses of platensimycin and its congeners, platensimycins B(1) and B(3), platensic acid, methyl platensinoate, platensimide A, homoplatensimide A, and homoplatensimide A methyl ester, are described. The convergent strategy developed toward these target molecules involved construction of their cage-like core followed by attachment of the various side chains through amide bond formation. In addition to a racemic synthesis, two asymmetric routes to the core structure are described: one exploiting a rhodium-catalyzed asymmetric cycloisomerization, and another employing a hypervalent iodine-mediated de-aromatizing cyclization of an enantiopure substrate. The final two bonds of the core structure were forged through a samarium diiodide-mediated ketyl radical cyclization and an acid catalyzed etherification. The rhodium-catalyzed asymmetric reaction involving a terminal acetylene was developed as a general method for the asymmetric cycloisomerization of terminal enynes. PMID- 19874025 TI - In vitro antioxidant activity and antigenotoxic effects of avenanthramides and related compounds. AB - Avenanthramides are substituted N-cinnamoylanthranilic acids, with hydroxycinnamic acid and anthranilic acid moieties. These alkaloid phenols, which are unique to oats, may confer health benefits via antioxidant or other mechanisms. Synthetic avenanthramides, hydroxycinnamic acids, Tranilast, and ascorbic acid were evaluated for antioxidant activity using two assays, DPPH (2,2 diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant potential), and for antigenotoxicity using the Comet assay with stressed human adenocarcinoma colon cells. Of all the compounds tested, N-(3',4'-dihydroxy-(E)-cinnamoyl)-5 hydroxyanthranilic acid (2c), an abundant oat avenanthramide, generally had the highest activity in all three assays. The drug Tranilast showed antigenotoxic effects, but not antioxidant activity, suggesting that antigenotoxicity is not dependent on antioxidant effects. Overall, results show that avenanthramides exert antioxidant and antigenotoxic activities that are comparable to those of ascorbic acid and which have the potential to exert beneficial physiological effects. PMID- 19874026 TI - pH-triggered disassembly in a caged protein complex. AB - Self-assembling protein cage structures have many potential applications in nanotechnology, one of which is therapeutic delivery. For intracellular targeting, pH-controlled disassembly of virus-like particles and release of their molecular cargo is particularly strategic. We investigated the potential of using histidines for introducing pH-dependent disassembly in the E2 subunit of pyruvate dehydrogenase. Two subunit interfaces likely to disrupt stability, an intratrimer interface (the N-terminus) and an intertrimer interface (methionine-425), were redesigned. Our results show that changing the identity of the putative anchor site 425 to histidine does not decrease stability. In contrast, engineering non native pH-dependent behavior and modulating the transition pH at which disassembly occurs can be accomplished by mutagenesis of the N-terminus and by ionic strength changes. The observed pH-triggered disassembly is due to electrostatic repulsions generated by histidine protonation. These results suggest that altering the degree of electrostatic repulsion at subunit interfaces could be a generally applicable strategy for designing pH-triggered assembly in protein macromolecular structures. PMID- 19874028 TI - Charge transport and dipolar relaxations in imidazolium-based ionic liquids. AB - Charge transport and dipolar relaxations in a series of imidazolium-based ionic liquids are studied by means of broadband dielectric spectroscopy. Despite the shift of more than 5 decades in the dielectric spectra upon systematic variation of the anion, scaling with respect to the dc conductivities and the characteristic rates yields a collapsing plot. The dielectric spectra are described at higher frequencies in terms of dipolar relaxations whereas hopping conduction in a random spatially varying energy landscape is quantitatively shown to dominate the spectra at lower frequencies. The beta-relaxations observed for both the precursor and the ionic liquids are assigned to librational motion of the imidazolium ring. The corresponding dielectric strength exhibits a strong dependence on the anion. PMID- 19874027 TI - Profiling of alpha-dicarbonyl content of commercial honeys from different botanical origins: identification of 3,4-dideoxyglucoson-3-ene (3,4-DGE) and related compounds. AB - The alpha-dicarbonyl contents of commercial honey samples from different botanical origins were analyzed as their quinoxaline derivatives using HPLC-DAD, HPLC-MS, HPLC-MS/MS, and HPLC-TOF-MS. A total of nine such compounds were detected, of which five were previously reported in honey (glucosone, 3 deoxyglucosone, glyoxal, methylglyoxal, and 2,3-butanedione) and three were reported only from sources other than honey [3-deoxypentulose, 1,4 dideoxyhexulose, and 3,4-dideoxyglucoson-3-ene (3,4-DGE)]. An unknown alpha dicarbonyl compound was also tentatively identified as an oxidation product of 3,4-DGE and was termed 3,4-dideoxyglucosone-3,5-diene (3,4-DGD). Only glyoxal (0.3-1.3 mg/kg), methylglyoxal (0.8-33 mg/kg), and 2,3-butanedione (0-4.3 mg/kg) were quantified in all honey samples. Furthermore, analysis of the alpha dicarbonyl profile of various honey samples indicated that certain alpha dicarbonyl compounds are found in specific honey samples in much higher proportions relative to the average amounts. The free radical scavenging activity as measured by DPPH method has also indicated that the darker honey samples such as buckwheat, manuka, blueberry, and eucalyptus had higher antioxidant properties compared to lighter-colored samples. PMID- 19874029 TI - Layered transition metal carboxylates: efficient reusable heterogeneous catalyst for epoxidation of olefins. AB - Layered metal carboxylates [M(malonato)(H(2)O)(2)](n) (M = Ni(II) and Mn(II)) that have a claylike structure have been synthesized hydrothermally and characterized. The interlayer separation in these layered carboxylates is comparable to that of the intercalation distance of the naturally occurring clay materials or layered double hydroxides (LDHs). In this study, we have demonstrated that, instead of intercalating the metal complex into layers of the clay or LDH, layered transition metal carboxylates, [M(malonato)(H(2)O)(2)](n), as such can be used as a recyclable heterogeneous catalyst in olefin epoxidation reaction. Metal carboxylates [M(malonato)(H(2)O)(2)](n) exhibit excellent catalytic performance in olefin epoxidation reaction. PMID- 19874030 TI - Facilitation of RNA enzyme activity in the molecular crowding media of cosolutes. AB - Short RNA sequences exhibiting the activity of a target RNA cleavage are promising for cellular gene regulation and biosensor research, but the reaction media different from an aqueous solution may cause unanticipated molecular interactions and properties. In this study, we investigated the molecular crowding effects arising from steric crowding and altered solvent properties on the hammerhead ribozyme activity using water-soluble neutral cosolutes. Poly(ethylene glycol) (PEG) and other cosolutes at 20 wt % increased the RNA hydrolysis rate by a factor of 2.0-6.6 at 10 mM MgCl(2) and much more at lower MgCl(2) concentrations. Remarkably, although the cosolutes decreased the stability of the ribozyme stem helices, the thermal inactivation temperature of the ribozyme was significantly raised, resulting in a higher reaction rate, up to 270 times at 50 degrees C. More significantly, PEG decreased the metal ion concentration to perform the reaction even with a limiting Mg(2+) or Na(+) concentration, facilitated the catalytic turnover, and activated a catalytically less active ribozyme sequence. These observations agreed that the cosolutes acted as an osmolyte stabilizing the water-release reaction of the RNA tertiary folding but destabilizing the water-uptake reaction of Watson-Crick base pairing. The opposite cosolute effect on the stabilities of RNA secondary and tertiary structures, which is fundamentally different from a protein folding, suggests how RNA stabilizes a tertiary structure and enhances the catalytic activity in molecular crowding media. PMID- 19874031 TI - Flow velocity profiles and shear banding onset in a semidilute wormlike micellar system under Couette flow. AB - Velocity profiles in Couette flow are measured in a wormlike micellar solution made of cetyltrimethylammonium bromide (CTAB), sodium salicylate (NaSal), and water, at R (= [NaSal]/[CTAB]) = 2 and at R = 4; [CTAB] = 100 mM. Velocity profiles were obtained by using a two-incident beam laser Doppler technique. Profiles reveal that one of the micellar solutions (R = 2) becomes heterogeneous a long time after flow inception, even at very low imposed shear rates. However, profiles do not correspond to what is expected for gradient shear banding, because the fluid splits in one section close to the moving cylinder where the local mean velocity depends linearly on the gap position and in a second section presenting important velocity fluctuations. Close to the static cylinder, there is a third section where the fluid does not flow; it behaves like a slipping block. On the other hand, at high imposed shear rates, the former slipping block flows and presents a linear profile. Here, velocity profiles are consistent with gradient shear banding. The onset of shear banding was observed. The picture of two stable shear bands separated by a thin steady interface is not always valid. Inhomogeneous flow could be observed, although it cannot be classified as shear banding. In addition, conditions can be found where, as shear rate is increased and before shear banding appears, instead of a thin interface, a fluctuating intermediate band can be observed. On the contrary, for the R = 4 solution, the flow never becomes heterogeneous even at high shear rates. Flow curves were measured in a Couette cell under shear rate control in two cases, when stress is sensed with the moving cylinder and when it is sensed with the static cylinder of the cell. Differences between the flow curves can be explained by using the velocity profiles for both solutions. PMID- 19874032 TI - Dynamic molecular propeller: supramolecular chirality sensing by enhanced chiroptical response through the transmission of point chirality to mobile helicity. AB - The secondary terephthalamide host 1a-H attached to four aryl blades was prepared from tetrabromide 2a by Suzuki-Miyaura coupling and undergoes a conformational change from a nonpropeller anti-form to a propeller-shaped syn-form upon complexation with ditopic guests such as p-xylylenediammonium derivatives (R,R)/(S,S)-3 (chirality generation). Through transmission of the point chiralities attached on the nitrogens in the chiral guests to the mobile helicity in 1a-H, the propeller-shaped host in the complex is biased to prefer a particular handedness (chirality biasing). While chiral guests with simple point chiralities such as (R,R)/(S,S)-3 exhibit only very weak CD activity, complexation with the dynamic propeller host 1a-H results in much stronger chiroptical signals (chiroptical enhancement). The chirality generation-chirality biasing protocol was successfully applied to a neurotransmitter, (-) phenylephrine 4, acting as a chiral ditopic guest. When the chiral auxiliaries are attached to the host as in (R,R)-1b-H, complexation with (S,S)-3 causes CD enhancement but not with (R,R)-3, due to chiral recognition. PMID- 19874033 TI - Metal ion facilitated dissociation of heme from b-type heme proteins. AB - Addition of Ni(2+), Cu(2+), or Zn(2+) (10-40 equiv) to metMb in sodium bicarbonate buffer (25 degrees C) at alkaline pH (7.8-9.5) results in a time dependent (2-6 h) change in the electronic absorption spectrum of the protein that is consistent with dissociation of the heme from the active site and that can be largely reversed by addition of EDTA. Similar treatment of cytochrome b(5), indoleamine 2,3-dioxygenase, and cytochrome P450(cam) (in the presence or absence of camphor) produces a similar spectroscopic response. Elution of metMb treated with Ni(2+) in this manner over an anion exchange column in buffer containing Ni(2+) affords apo-myoglobin without exposure to acidic pH or organic solvents as usually required. Bovine liver catalase, in which the heme groups are remote from the surface of the protein, and horseradish peroxidase, which has four disulfide bonds and just three histidyl residues, exhibit a much smaller spectroscopic response. We propose that formation of carbamino groups by reaction of bicarbonate with protein amino groups promotes both protein solubility and the interaction of the protein with metal ions, thereby avoiding precipitation while destabilizing the interaction of heme with the protein. From these observations, bicarbonate buffers may be of value in the study of nonmembrane proteins of limited solubility. PMID- 19874034 TI - Experimental and theoretical investigation of the pyrrole/Al(100) interface. AB - The electronic properties of the pyrrole/Al(100) interface have been investigated from both a theoretical and experimental point of view. Electron energy loss spectroscopy (EELS) in specular reflection geometry does not reveal modification of the electronic structure of the molecule when adsorbed on the Al surface. EELS results and the low desorption temperature of pyrrole indicate a weak molecule/metal interaction. Ab initio calculations in the framework of the single particle density functional theory within the local density approximation was used to investigate the adsorption energy and geometry. The low adsorption energy, -0.51 eV per molecule, and the high N-Al distance, 1.98 A, confirm the weak interaction of pyrrole adsorbed on the Al surface. PMID- 19874035 TI - Design of HIV protease inhibitors based on inorganic polyhedral metallacarboranes. AB - HIV protease (HIV PR) is a primary target for anti-HIV drug design. We have previously identified and characterized substituted metallacarboranes as a new class of HIV protease inhibitors. In a structure-guided drug design effort, we connected the two cobalt bis(dicarbollide) clusters with a linker to substituted ammonium group and obtained a set of compounds based on a lead formula [H(2)N-(8 (C(2)H(4)O)(2)-1,2-C(2)B(9)H(10))(1',2'-C(2)B(9)H(11))-3,3'-Co)(2)]Na. We explored inhibition properties of these compounds with various substitutions, determined the HIV PR:inhibitor crystal structure, and computationally explored the conformational space of the linker. Our results prove the capacity of linker substituted dual-cage cobalt bis(dicarbollides) as lead compounds for design of more potent inhibitors of HIV PR. PMID- 19874037 TI - New route to produce dry colloidal crystals without cracks. AB - We report a new route for fabricating opal films in which the particles are bounded by polymer gel. A loosely packed colloidal crystal immobilized in a hydrogel is homogeneously shrunk and dried and converted into a crack-free opal film. The obtained film shows a uniform diffraction color and excellent transmission spectral properties inherited from the starting state. The optical stop band wavelength is adjustable by varying the amount of gel-polymer. PMID- 19874038 TI - Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers. AB - The new phase K(12)Au(21)Sn(4) has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) A, V = 1901.3(7) A(3), and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au(20)) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn(4)). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K(3)Au(5)In and Rb(2)Au(3)Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22). PMID- 19874036 TI - Structure--activity relationships of polymyxin antibiotics. PMID- 19874039 TI - Impact of ATRP initiator spacer length on grafting poly(methyl methacrylate) from silica nanoparticles. AB - We quantified the impact of the carbon spacer length (CSL) of immobilized alkoxysilanes initiators on grafting poly(methyl methacrylate) (PMMA) from the surfaces of monodisperse silica nanoparticles. PMMA was grafted using surface initiated atom transfer radical polymerization (SI-ATRP), a facile technique to produce well-controlled polymer brushes. The polymerizations were carried out in environmentally friendly 4:1 (v/v) methanol-water solutions at room temperature. Monoethoxysilane initiators of 3, 11, and 15 carbon spacer lengths were synthesized and characterized with (1)H NMR and (13)C NMR. The initiators were then used to modify the surfaces of monodisperse silica nanoparticles in methyl isobutyl ketone, producing dense initiator monolayers with site densities between 1.8-3.6 initiators/nm(2). PMMA was subsequently grafted from the functionalized nanoparticles using both CuCl and CuBr catalysts. We found that polymerizations performed with CuBr were uncontrolled, whereas those with CuCl were controlled. PMMA graft densities ranged between 0.10-0.43 polymers/nm(2), which increased with the initiator carbon spacer length (CSL). Interestingly, longer CSLs make nanoparticle surfaces hydrophobic, causing nanoparticle aggregation in methanol water solutions. Our results indicate that surface hydrophobicity correlates to increases in PMMA graft density through the adsorption of hydrophobic MMA monomers on initiators with longer CSLs. Thus, to augment PMMA graft densities, a subtle balance must be struck between enabling particle stability and increasing MMA adsorption in methanol-water solutions. PMID- 19874040 TI - Oxidizing Ru(II) complexes as irreversible and specific photo-cross-linking agents of oligonucleotide duplexes. AB - Oxidizing polyazaaromatic Ru(II) complexes containing two TAP ligands (TAP = 1,4,5,8-tetraazaphenanthrene) are able under illumination to cross-link irreversibly the two strands of an oligonucleotide (ODN) duplex by covalent bond formation. The cross-linking proceeds by two successive absorptions of a photon. An adduct of the metallic complex on a guanine (G) base of one ODN strand is first photoproduced, followed by a second photoaddition of the same Ru species to a G base of the complementary strand, provided that the two G moieties are separated by 0 or 1 base pair. These two processes lead to the cross-linking of the two strands. Such a photo-cross-linking is easily detected with [Ru(TAP)(2)(phen)](2+) (1; phen = 1,10-phenanthroline) and [Ru(HAT)(2)(phen)](2+) (2; HAT = 1,4,5,8,9,12-hexaazatriphenylene), whereas it is not observed with [Ru(TAP)(2)TPAC](2+) (3; TPAC = tetrapyridoacridine) at the same level of loading of the duplex by 3. With a concentration of 3 similar to that of 1 and 2, when the loading of the duplex by 3 is much more important than with 1 and 2, the photo-cross-linking with 3 can thus also be observed. As 3 intercalates its TPAC ligand into the base pairs stack, its mobility is restricted in the duplex. In contrast, 1 and 2 can adopt different geometries of interaction, which probably facilitate the photo-cross-linking. PMID- 19874041 TI - Core-shell chromium silicide-silicon nanopillars: a contact material for future nanosystems. AB - Chromium silicide nanostructures are fabricated inside silicon nanopillars grown by the vapor-liquid-solid mechanism. The remarkable field-emission behavior of these nanostructures results from extensive improvement of carrier transport due to the reduced energy barrier between the metal and semiconductor layers. The results warrant consideration of chromium silicide as a potentially important contact material in future nanosystems. PMID- 19874042 TI - Total synthesis of (+/-)-cordypyridones A and B and related epimers. AB - Efficient racemic synthesis of two antibacterial and antimalarial natural products, cordypyridones A and B, was achieved from inexpensive, commercially available starting materials in an overall yield of 15% (8% and 7%, respectively). This convergent synthesis utilizes a key coupling step of two fragments and the subsequent functional group transformations lead to the target compounds and their 8-epi-analogues. PMID- 19874043 TI - Hypoglycemic polysaccharides from the tuberous root of Liriope spicata. AB - Previous studies showed that the water extract and crude polysaccharides from the tuberous root of Liriope spicata var. prolifera showed high hypoglycemic and hypolipidemic activities. In the present study, two new water-soluble polysaccharides, named LSP1 and LSP2, were isolated from the active crude polysaccharides by DEAE-cellulose 52 and AB-8 macroporous resin chromatography and tested for their hypoglycemic effects. On the basis of the chemical and physical data obtained, LSP1 and LSP2 are two fructans with the molecular weights 3.20 and 4.29 kDa, respectively, which both have a backbone structure of beta-(1- >2)-fructosyl residues that branches at O-6 with fructosyl residues and terminates with a glucosyl residue and a fructosyl residue. Preliminary activity tests revealed that both LSP1 and LSP2 caused a significant decrease of the fasting blood glucose (FBG) and a significant improvement on glucose tolerance in type 2 diabetic mice. These results suggest that LSP1 and LSP2 show high potential to be explored as natural oral hypoglycemic agents. PMID- 19874044 TI - Bioactive constituents of the stem bark of Mitrephora glabra. AB - Bioactivity-guided fractionation of the stem bark of Mitrephora glabra yielded nine compounds, comprising three ent-kaurenoids (1-3), five polyacetylenic acids/esters (4-8), and one aporphine alkaloid, liriodenine (9). The structures of the six new compounds (1-3, 5, 7, and 8) were determined by spectroscopic data interpretation. All compounds were evaluated for their inhibitory activities against a panel of cancer cell lines and a battery of microorganisms. PMID- 19874045 TI - Structural, electronic, and magnetic properties of gold cluster anions doped with zinc: Au(n)Zn- (2 < or = n < or = 10). AB - The geometrical structures, relative stabilities, electronic, and magnetic properties of zinc-doped gold cluster anions Au(n)Zn(-) (2 < or = n < or = 10) have been systematically investigated by means of first-principles density functional calculations at the B3LYP level. The results show that the most stable isomers have a planar structure and resemble pure gold cluster anions in shape, and no 3D isomers were obtained. Calculated dissociation energy, the second difference energy, and the highest occupied-lowest unoccupied molecular orbital gaps as a function of the cluster size exhibit a pronounced even-odd alternation phenomenon. The first vertical detachment energy of the anion clusters were calculated and compared with available experimental results. A good agreement between experimental and theoretical results suggests good prediction of the lowest-energy structures for all clusters calculated in the present study. Furthermore, both the local and total magnetic moments display a pronounced odd even oscillation with the number of gold atoms. PMID- 19874046 TI - Capturing electrochemically evolved nanobubbles by electroless deposition. A facile route to the synthesis of hollow nanoparticles. AB - Gas evolution during electrochemical deposition has long been regarded as undesired and deliberately suppressed. Here, we show a new role of electrochemically evolved hydrogen bubbles, serving as both templates and reducing agent to form hollow Au nanoparticles via electroless deposition. Hollow gold nanoparticles with a complete nanocrystalline shell and a 50 nm hollow core were fabricated. By controlling the shell thickness, particle size can be varied from 100 to 150 nm. The process is very simple, scalable, and with a high throughput. Using this method, more complicated hollow nanostructures such as double nanoshells ("nanomatryoshka") can also be synthesized. These hollow nanoparticles possess desirable plasmonic properties and can potentially be used as nanocontainers to store and deliver gaseous materials. In addition, the process can be used for fundamental studies of nanobubble formation mechanism. PMID- 19874047 TI - Kinetics of stop codon recognition by release factor 1. AB - Recognition of stop codons by class I release factors is a fundamental step in the termination phase of protein synthesis. Since premature termination is costly to the cell, release factors have to efficiently discriminate between stop and sense codons. To understand the mechanism of discrimination between stop and sense codons, we developed a new, pre-steady state kinetic assay to monitor the interaction of RF1 with the ribosome. Our results show that RF1 associates with similar association rate constants with ribosomes programmed with stop or sense codons. However, dissociation of RF1 from sense codons is as much as 3 orders of magnitude faster than from stop codons. Interestingly, the affinity of RF1 for ribosomes programmed with different sense codons does not correlate with the defects in peptide release. Thus, discrimination against sense codons is achieved with both an increase in the dissociation rates and a decrease in the rate of peptide release. These results suggest that sense codons inhibit conformational changes necessary for RF1 to stably bind to the ribosome and catalyze peptide release. PMID- 19874048 TI - Identification of the rate-determining step of tRNA-guanine transglycosylase from Escherichia coli. AB - The modified RNA base queuine [7-(4,5-cis-dihydroxy-1-cyclopenten-3 ylaminomethyl)-7-deazaguanine] is present in tRNA because of a unique base exchange process catalyzed by tRNA-guanine transglycosylase (TGT). Previous studies have suggested the intermediacy of a covalent TGT-RNA complex. To exist on the reaction pathway, this covalent complex must be both chemically and kinetically competent. Chemical competence has been demonstrated by the crystal structure studies of Xie et al. [(2003) Nat. Struct. Biol. 10, 781-788]; however, evidence of kinetic competence had not yet been established. The studies reported here unequivocally demonstrate that the TGT-RNA covalent complex is kinetically capable of occurring on the TGT reaction pathway. These studies further suggest that dissociation of product RNA from the enzyme is overall rate-limiting in the steady state. Interestingly, studies comparing RNA with a 2'-deoxyriboside at the site of modification suggest a role for the 2'-hydroxyl group in stabilizing the growing negative charge on the nucleophilic aspartate (264) as the glycosidic bond to the aspartate is broken during the breakdown of the covalent complex. PMID- 19874049 TI - Proteomic analyses of the developing chicken cardiovascular system. AB - Up until today, no proteomics approaches have been described for heart muscle development. We describe a proteomics method to study the proteome of different heart structures at three stages of chicken embryonic development. For this purpose, a combination of gel separation, nanoLC separation and mass spectrometry was used. With this method, we identified in total 267 proteins in different tissue structures of chicken heart. We observed differences in protein abundance for a number of proteins between the different tissue structures and time points of development using spectral counting as a semiquantitative measure of protein abundance. For myosin-heavy chain 6, myosin-heavy chain 7, titin, connectin, collagen alpha-1, and xin, differences in protein levels for the different stages and structures (great arteries, outflow tract and ventricles) have been observed. A pathway analysis is performed in which the identified proteins are related to theoretical protein networks. Most prominent was the 'cardiovascular system development and function' network with the abundantly present proteins myosin 6 and myosin 7. We showed that myosin 6 is highly regulated in a stage and heart tissue specific manner. In conclusion, this method can be used to study changes in protein levels of chicken heart tissue in a spatiotemporal manner. PMID- 19874050 TI - Phase transition of two-dimensional chiral supramolecular nanostructure tuned by electrochemical potential. AB - Molecular chiralty and phase transition of p-phenylenedi(alpha-cyanoacrylicacid) di-n-ethyl ester (p-CPAEt) assembled on Au(111) have been studied in the electric double layer region in 0.1 M HClO(4) by electrochemical scanning tunneling microscopy (ECSTM) technique. Three types of chiral supramolecular nanostructures were resolved at differently charged interfaces. Within a potential range (0.65 V < E < 0.8 V, region I), a close-packed physisorbed adlayer of chiral stripe pattern, with the (3 x 6) structure, has been observed. At more negative potential (0.2 V < E < or = 0.65 V, region II), the stripe patterns gradually dissolved, and two types of new chiral network structures (3 square root(7) x 4 square root(7)) and (3 square root(7) x 3 square root(7)) evolved on reconstructed and unreconstructed surfaces, respectively. On the basis of the high-resolution STM images, it was tentatively proposed that three types of chiral supramolecular nanostructures were formed by two-dimensional adsorption induced chiral p-CPAEt species together with lateral hydrogen-bonding interaction (C-H...N[triple bond]C). Intriguingly, ECSTM images allow in situ monitoring of the phase transition process of these chiral adlayers driven by the electrochemical potential. The detailed dynamic results showed that the chiral two-dimensional adlayers could be reversibly tuned purely by the applied electrode potential. PMID- 19874051 TI - Fabrication of oriented antibody-conjugated magnetic nanoprobes and their immunoaffinity application. AB - In an attempt to fabricate highly active immunoprobes for serum biomarker detection, we report a simple and effective method for site-specific and self oriented immobilization of antibodies on magnetic nanoparticles (MNPs). Through boronate formation, the carbohydrate moiety within the constant domain, Fc, of the antibody can be specifically and covalently linked to a boronic acid functionalized MNP (BA@MNP) without hindering the antigen binding domain, Fab. The performance was evaluated by immunoaffinity extraction of multiple serum antigens. Compared with the random immobilization of antibody on a MNP, the antibody self-oriented immunoprobe provides long-term stability (>2 months) and 5 fold extraction efficiency. It also provides 5-fold improved sensitivity at a low nM range (0.4 nM), presumably through enhanced antibody@MNP activity. In addition, false-positive detections arising from nonspecific binding can be completely minimized by effective surface protection using concentration dependent dextran blocking. Compared with conventional antibody site-specific immobilization through protein G, this new BA-mediated covalent antibody immobilization provides interference-free extraction resulting from noncovalent immobilization of antibody by protein G. The new immunoassay was applied in comparative profiling of serum amyloid P (SAP), serum amyloid A (SAA), and C reactive protein (CRP) in human serum. Our triple immunoassay revealed a distinct pattern among normal patients, patients with cancer, and patients with cardiovascular disease. Using the previously reported quantization capability of the MALDI MS readout, we expect that this site-specific immunonanoprobe-based immunoassay can be highly active, rapid, and accurate in nanodiagnosis. PMID- 19874052 TI - Microsecond analysis of transient molecules using bi-directional capillary electrophoresis. AB - We demonstrate the feasibility for minimizing electrophoretic analysis times of transient chemical species by inducing nascent, oppositely charged photochemical products to migrate in opposite directions from their point of creation. In this approach, separate probe sites are positioned within an electrophoretic channel both upfield and downfield from a photoreaction site formed by high-numerical aperture optics, with positively charged (and in some cases neutral) components migrating toward one probe site and negatively charged species migrating in the opposite direction, toward the second probe site. As a proof-of-concept, fluorescent photoproducts of the hydroxyindoles, 5-hydroxytryptamine (serotonin), 5-hydroxytrptophan, and 5-hydroxyindole-2-carboxylic acid, are formed within a geometrically modified capillary and are transported electrophoretically and electroosmotically to probe sites several micrometers away. Although it is possible to detect all components in a single channel, or to use a two-channel imaging approach to independently detect positive and negative components, we have found the most rapid analysis approach involves a protocol in which laser light is alternately directed to opposing probe sites at high frequency (1 kHz), a strategy that allows positive and negative species to be detected with no cross talk, even when components have overlapping detection times. Fluorescence-signal averaging is performed on each temporal channel via summation of the two sequences of interdigitized electrophoretic traces. This approach allows photoproducts to be detected free from interferences from oppositely charged species, enabling positive and negative species in a mixture to be analyzed electrophoretically in ca. 6 micros, a period several-fold faster than was previously feasible using unidirectional electrophoresis. PMID- 19874053 TI - Development of a linear ion trap/orthogonal-time-of-flight mass spectrometer for time-dependent observation of product ions by ultraviolet photodissociation of peptide ions. AB - A hybrid linear ion trap/orthogonal time-of-flight (TOF) mass spectrometer has been developed to observe time-dependent vacuum ultraviolet photodissociation product ions. In this apparatus, a reflectron TOF mass analyzer is orthogonally interfaced to an LTQ using rf-only octopole and dc quadrupole ion guides. Precursor ions are generated by electrospray ionization and isolated in the ion trap. Subsequently they are directed to the TOF source where photodissociation occurs and product ions are extracted for mass analysis. To detect photodissociation product ions having axially divergent trajectories, a large rectangular detector is utilized. With variation of the time between photodissociation and orthogonal extraction in the TOF source, product ions formed over a range of times after photoexcitation can be sampled. Time-dependent observation of product ions following 157 nm photodissociation of a singly charged tryptic peptide ion (NWDAGFGR) showed that prompt photofragment ions (x- and v-type ions) dominate the tandem mass spectrum up to 1 micros after the laser shot, but the intensities of low energy thermal fragment ions (y-type ions) become comparable several microseconds later. Different proton mobilization time scales were observed for arginine- and lysine-terminated tryptic peptides. PMID- 19874054 TI - Quenching-resistant multiple micro-flame photometric detector for gas chromatography. AB - A multiple flame photometric detector (mFPD) based on many flames operated in series is introduced for the detection of sulfur and phosphorus compounds. The method employs attributes of a previously developed micro counter-current flame technique to readily establish any number of very small compact flames inside a narrow quartz tube. Results show for the first time that a five flame mFPD mode can improve hydrocarbon quenching resistance nearly 20-fold relative to a single flame (i.e., conventional FPD) mode, and nearly 10-fold relative to a two flame (i.e., dual FPD) mode. Under these conditions, the five flame mFPD mode is shown to maintain about 60% of its original analyte chemiluminescence even in the presence of over 100 mL/min of methane flow into the detector. In contrast to a conventional dual FPD device, the five flame mFPD mode also provides analyte sensitivity that is similar to a conventional FPD. Of note, the mFPD yields minimum detectable limits for sulfur and phosphorus of 4 x 10(-11) g S/s and 3 x 10(-12) g P/s respectively. Analyte selectivity over hydrocarbons, signal reproducibility, and response equimolarity are also improved in the mFPD, making it a potentially useful detector for applications in gas chromatography. PMID- 19874055 TI - Bipolar electrode focusing: simultaneous concentration enrichment and separation in a microfluidic channel containing a bipolar electrode. AB - A method for simultaneously concentrating and separating analytes in a buffer filled microfluidic channel is reported. The approach is based on modulation of the local electric field within the channel and the corresponding opposition of electrophoretic and electroosmotic flow (EOF) velocities. Dye molecules having different electrophoretic mobilities are focused at different locations within the channel where concentration takes place. At least three species, all small dye molecules, can be simultaneously concentrated and separated, with localized enrichment factors up to approximately 600 achieved within 400 s. The enrichment zones affect the electric field profile, as evidenced by significant differences in focusing of single versus multiple analytes. The EOF could be modulated by modifying the channel walls with an appropriate polymer, and this had the effect of increasing both the enrichment factors and resolution of the separation. Numerical simulations provide insights into the underlying fundamental principles for the experimental findings. PMID- 19874057 TI - Stir membrane extraction: a useful approach for liquid sample pretreatment. AB - In this paper, a novel extraction approach based on the use of a polymeric membrane as the extraction medium is described. For this aim, an original unit which allows the magnetic stirring of the membrane during the extraction process has been designed, optimized, and practically evaluated. On one hand, the main variables affecting the extraction process such as the unit design, the stirring rate, the extraction time, the sample volume, and the elution conditions were deeply studied. Once optimized, a model analytical problem, the determination of polycyclic aromatic hydrocarbons in water samples, was selected for practical evaluation of the stir membrane extraction procedure. The method was characterized on the basis of its linearity, precision, and limits of detection. The novel approach was sensitive and precise enough for the detection of the target analytes in the low nanogram per liter range using 25 mL of sample. In fact, limits of detection ranged from 0.8 ng/L (fluoranthene) to 7.6 ng/L (benzo anthracene) with relative standard deviations lower than 8%. PMID- 19874056 TI - Rapid determination of RNA accessible sites by surface plasmon resonance detection of hybridization to DNA arrays. AB - RNA accessible sites are the regions in an RNA molecule that are available for hybridization with cDNA or RNA molecules. The identification of these accessible sites is a critical first step in identifying antisense-mediated gene suppression sites, as well as in a variety of other RNA-based analysis methods. Here, we present a rapid, hybridization-based, label-free method of identifying RNA accessible sites with surface plasmon resonance imaging (SPRi) on in situ synthesized oligonucleotide arrays prepared on carbon-on-metal substrates. The accessible sites of three pre-miRNAs, miRNA precursors of approximately 75 nt in length, were determined by hybridizing the RNA molecules to RNA-specific tiling arrays. An array composed of all possible 6mer oligonucleotide sequences was also utilized in this work, offering a universal platform capable of studying RNA molecules in a high throughput manner. PMID- 19874058 TI - Wavelet orthogonal signal correction-based discriminant analysis. AB - We report the use of wavelet orthogonal signal correction (WOSC) for multivariate classification. This new classification tool combines a wavelet prism decomposition of a spectral response and orthogonal signal correction to significantly improve the classification performance, reducing both classification errors and model complexity. Two spectroscopic data sets are examined in this paper. We show that a discriminant analysis based on WOSC effectively removes irrelevant classification information from spectral responses. WOSC-based discriminant analysis performs favorably as compared to a wavelength-domain filtering approach, such as that used in orthogonal partial least-squares discriminant analysis (OPLS-DA). PMID- 19874059 TI - In-source fragmentation of very labile peptides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. AB - Synthetic acidic proline-rich peptides devoid of basic chemical groups were studied by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF). Their ion mass spectra recorded in reflector positive ion mode have shown unusual features, i.e., absence or very weak presence of protonated peptide together with a major peak associated with fragmentation at a site that corresponds to the amide bond N-terminal to the first proline of the XPP motif. In contrast, arginine-containing analogues were stable in MALDI-TOF, whereas peptides sharing a free N-terminal amino group were moderately subject to the same fragmentation. Effects of extraction delay time suggest that this process takes place very early (nanoseconds) at the beginning of the plume expansion. The effect of the nature of the matrix on the survival yield indicates a better correlation with the initial axial velocity than with the matrix proton affinity. All the data show some strong differences with the classical in-source decay (ISD). Our results suggest the role of the available protons in the close neighborhood of the peptide during the crystallization process and the prompt fragmentation induced by collisions in the first step of ablation. Undoubtedly, our study highlights that the MALDI-TOF analysis of peptides containing proline and no basic group should be carried out with extreme caution. PMID- 19874060 TI - Chemical methods for the detection of protein N-homocysteinylation via selective reactions with aldehydes. AB - Elevated blood levels of homocysteine (Hcy), hyperhomocysteinemia or homocystinuria, have been associated with various diseases and conditions. Homocysteine thiolactone (Hcy TL) is a metabolite of Hcy and reacts with amine groups in proteins to form stable amides, homocystamides, or N-homocysteinylated proteins. It has been proposed that protein N-homocysteinylation contributes to the cytotoxicity of elevated Hcy. Due to its heterogeneity and relatively low abundance, detection of this posttranslational modification remains challenging. On the other hand, the gamma-aminothiol group in homocystamides imparts different chemical reactivities than the native proteins. Under mildly acidic conditions, gamma-aminothiols irreversibly and stoichiometrically react with aldehydes to form stable 1,3-thiazines, whereas the reversible Schiff base formation between aldehydes and amino groups in native proteins is markedly disfavored due to protonation of amines. As such, we have developed highly selective chemical methods to derivatize N-homocysteinylated proteins with various aldehyde tags, thereby facilitating the subsequent analyses. For instance, fluorescent or biotin tagging coupled with gel electrophoresis permits quantification and global profiling of complex biological samples, such as hemoglobin and plasma from rat, mouse and human; affinity enrichment with aldehyde resins drastically reduces sample complexity. In addition, different reactivities of lysine residues in hemoglobin toward Hcy TL were observed. PMID- 19874064 TI - General reaction conditions for the palladium-catalyzed vinylation of aryl chlorides with potassium alkenyltrifluoroborates. AB - Activated and deactivated aryl and heteroaryl chlorides are efficiently cross coupled with potassium vinyl- and alkenyltrifluoroborates using 4 hydroxyacetophenone oxime derived palladacycle as precatalyst in 1 to 3 mol % Pd loading, Binap as ligand, and Cs(2)CO(3) as base in DMF at 120 degrees C. The reactions can also be performed using Pd(OAc)(2) as Pd(0) source, although with lower efficiency. Bidentate ligands such as Binap and dppp can be used, the former being the best choice. Only in the case of deactivated aryl chlorides should the reaction temperature be increased to 160 degrees C to achieve good yields. The corresponding cross-coupled compounds, such as styrenes, stilbenes, and alkenylarenes, are obtained in good yields and with high regio- and diastereoselectivity. PMID- 19874061 TI - Quantitative measurement of zinc secretion from pancreatic islets with high temporal resolution using droplet-based microfluidics. AB - We assayed glucose-stimulated insulin secretion (GSIS) from live, murine islets of Langerhans in microfluidic devices by the downstream formation of aqueous droplets. Zinc ions, which are cosecreted with insulin from beta-cells, were quantitatively measured from single islets with high temporal resolution using a fluorescent indicator, FluoZin-3. Real-time storage of secretions into droplets (volume of 0.470 +/- 0.009 nL) effectively preserves the temporal chemical information, allowing reconstruction of the secretory time record. The use of passive flow control within the device removes the need for syringe pumps, requiring only a single hand-held syringe. Under stimulatory glucose levels (11 mM), bursts of zinc as high as approximately 800 fg islet(-1) min(-1) were measured. Treatment with diazoxide effectively blocked zinc secretion, as expected. High temporal resolution reveals two major classes of oscillations in secreted zinc, with predominate periods at approximately 20-40 s and approximately 5-10 min. The more rapid oscillation periods match closely with those of intraislet calcium oscillations, while the slower oscillations are consistent with insulin pulses typically measured in bulk islet experiments or in the bloodstream. This droplet sampling technique should be widely applicable to time-resolved cellular secretion measurements, either in real-time or for postprocessing. PMID- 19874062 TI - Microarray-based multiplexed scanometric immunoassay for protein cancer markers using gold nanoparticle probes. AB - We report the use of electroless gold deposition as a light scattering signal enhancer in a multiplexed, microarray-based scanometric immunoassay using gold nanoparticle probes. The use of gold development results in greater signal enhancement than the typical silver development, and multiple rounds of metal development were found to increase the resulting signal compared to one development. Using these conditions, the assay was capable of detecting 300 aM (approximately 9000 copies) of prostate specific antigen in buffer and 3 fM in 10% serum. Additionally, the highly selective detection of three protein cancer markers at low picomolar concentrations in buffer and 10% serum was demonstrated. The use of gold deposition may have significant utility in scanometric detection schemes and broader clinical and research applications. PMID- 19874065 TI - Photoinitiated domino reactions: N-(adamantyl)phthalimides and N (adamantylalkyl)phthalimides. AB - Phthalimides 1-6 undergo photochemical reactions upon direct irradiation as well as triplet sensitization and give rise to new products. Besides formation of the primary photoproducts, the first photochemical step initiates a subsequent thermal domino reaction or a domino sequence of a thermal and a photochemical reaction. The latter, involving two photochemical intramolecular gamma-H abstractions, was observed with phthalimides 1, 3, and 6 and delivered stereospecifically the hexacyclic benzazepine products 12, 19, and 27, respectively. The lowest triplet states of 1-6 were characterized in several solvents upon direct and acetone-sensitized excitation. The intermolecular electron transfer from triethylamine and DABCO was studied, and the radical anions were observed. Electrochemical measurements showed that intramolecular electron transfer from the adamantyl group of 1-6 to the lowest triplet state of the phthalimides is not feasible. The formation of products can be explained by intramolecular H-abstraction from the (alkyl)adamantane to the excited phthalimide, either from the excited singlet state or a hidden upper excited triplet state. PMID- 19874066 TI - Palladium-catalyzed carbamoylation of aryl halides by tungsten carbonyl amine complex. AB - In the presence of aminepentacarbonyltungsten, base, and a catalytic amount of palladium(0) complex, carbamoylation of aryl halide proceeds to afford amide. The reaction may involve transmetalation between palladium(II) intermediate and carbamoyltungstenate that is generated in situ. This catalytic cross-coupling reaction provides an alternative method to the conventional palladium-catalyzed amidation by using gaseous carbon monoxide. PMID- 19874067 TI - Synthesis of tetrahydropyrans from propargyl alcohols and 1,1 cyclopropanediesters: a one-pot ring-opening/Conia-ene protocol. AB - Lewis acid catalyzed ring opening of 1,1-cyclopropanediesters by the hydroxyl group of a propargyl alcohol sets up a subsequent Conia-ene cyclization to afford substituted tetrahydropyrans in a one-pot, high-yielding procedure. PMID- 19874068 TI - A practical total synthesis of globo-H for use in anticancer vaccines. AB - An improved synthesis of the hexasaccharide MBr1 antigen (globo-H) is reported. Enhanced efficiency in the synthesis was necessary for the scale-up production of globo-H, in order to advance globo-H-based anticancer vaccines to clinical trials. The key features of the improved synthesis include preactivation-based glycosylations and a revised iodosulfonimidation/rearrangement. PMID- 19874070 TI - Challenges in current adult fish laboratory reproductive tests: suggestions for refinement using a mummichog (Fundulus heteroclitus) case study. AB - Concerns about screening endocrine-active contaminants have led to the development of a number of short-term fish reproductive tests. A review conducted of 62 published adult fish reproductive papers using various fish species found low samples sizes (mean of 5.7 replicates with a median of 5 replicates) and high variance (an average coefficient of variance of 43.8%). The high variances and low sample sizes allow only relatively large differences to be detected with the current protocols; the average significant difference detected was a 68.7% reduction in egg production, while only differences above 50% were detected with confidence. This result indicates low power to detect more subtle differences and a high probability of type II errors in interpretation. The present study identifies several ways to increase the power of the adult fish reproductive test in the mummichog (Fundulus heteroclitus). By identifying the peak timing of egg production (before and after the new moon), extending the duration of the experiment (increased from 7 to 14 d), and determining that a sample size of eight replicate tanks per treatment accurately predicts variance in the sample population (based on pre-exposure variation calculations of replicate tanks), the power of the test has been significantly increased. The present study demonstrates that weaknesses in the current adult fish reproductive tests can easily be addressed by focusing on improved understanding of the reproductive behavior of the test species and developing study designs that include calculating desired variability levels and increasing replicates. PMID- 19874071 TI - A new species of trichostrongyloid in African buffalo (Syncerus caffer) (Artiodactyla: Bovinae) from Uganda. AB - Africanastrongylus giganticus n. sp. is described based on large ostertagiine nematodes occurring in the abomasum of African buffalo, Syncerus caffer, from Uganda; this represents the second species recognized in the genus. Specimens of A. giganticus are characterized by large size (15-19 mm in total length), a strongly tapering synlophe in the cervical region, and a great number of ridges at all levels of the body (maximum 72 attained in the third quarter); numbers of ridges exceed that reported among any known genera and species of the Ostertagiinae. We refer A. giganticus to this genus based on a strongly tapering lateral synlophe, relatively large numbers of ridges at all levels of the body, miniscule cervical papillae, poorly demarcated divisions of the ovejector, absence of vulval cuticular inflations, and the presence of slightly protruding lips at the vulva. It is distinguished from its congener, Africanastrongylus buceros, in total length, maximum number of ridges (68-72 vs. 53, respectively), structure and disposition of the synlophe, presence of strongly spiraled ovarian tracks, and eggs that are distributed in 3 or more rows in the uterus. A superficial resemblance to Longistrongylus meyeri, the only other large ostertagiine in the African fauna, is evident; these species, however, are distinct based on the synlophe and other characters. Recognition of a second species of Africanastrongylus represented by nematodes of large size suggests that prior reports of L. meyeri in Syncerus caffer may be attributable to A. giganticus. PMID- 19874072 TI - Helminth parasites of amphibians and reptiles from the Ucayali Region, Peru. AB - Twenty individual amphibians representing 9 species within 6 families and 44 individual reptiles representing 15 species within 8 families from the Ucayali Region, Peru, were examined for helminths. Seven (35%) of the amphibian species and 15 (34%) of the reptiles were found to harbor at least 1 species of helminth; 5 (25%) of the amphibians and 4 (9%) of the reptiles harbored multiple infections. A cyclophyllidean cestode and 14 taxa of nematodes within 7 families were found in the herpetofauna surveyed. Thirteen new host and 6 new geographic distribution records are documented. PMID- 19874073 TI - An outbreak of angiostrongyliasis cantonensis in Beijing. AB - An outbreak of 81 cases of angiostrongyliasis cantonensis (AC) occurred in Beijing, China, during June through September 2006. Epidemiological characteristics, clinical signs and symptoms, laboratory tests, imaging, and treatment data from the 81 AC patients were collected and analyzed. All cases had a history of eating raw freshwater snails, and acquired Angiostrongylus cantonensis as a result. The incubation period ranged from 1 to 36 days. The main symptoms were fever, severe headache, neck stiffness, and skin paresthesia. A significant increase in eosinophilia occurred in the peripheral blood of 62 cases and in cerebrospinal fluid of 64 cases; 36 patients presented a linearly enhanced abnormal signal of the leptomeninges site during a cranial MRI examination, indicative of meningitis; 18 cases had a significant nodule shadow and spot flaky ground-glass shadow on chest computerized tomography. All patients were relieved of their illness with a 7-day treatment of albendazole. PMID- 19874075 TI - A systematic review of the effectiveness of treadmill training for children with cerebral palsy. AB - PURPOSE: The development of efficient and independent walking is an important therapeutic goal for many children with cerebral palsy (CP). Consequently, there has been growing interest in determining the effects of treadmill training programs for these children. METHOD: A systematic review of the literature was conducted to evaluate the effectiveness of treadmill training for children with CP. Relevant trials were identified by searching electronic databases and by citation tracking. RESULTS: Of 125 papers initially identified, five met the criteria for review. Results showed that treadmill training is safe and feasible for children with CP across a wide range of ages and functional abilities. Children with more severely affected walking ability significantly increased their walking speed (d = 1.48, 95% CI: 0.49-2.40) and gross motor performance (d = 1.5, 95% CI: 0.50-2.50) after training. However, the results also suggested that treadmill speed and length of training sessions might need to be set to specifically match desired intervention goals such as increasing walking speed or endurance. CONCLUSIONS: The review suggests that treadmill training is safe and feasible for children with CP and indicates that there may be some positive benefits in walking speed over short distances and in general gross motor skills. The provision of PBWS may be particularly beneficial for children with more severe walking disability (GMFCS III and IV). Further research is necessary before it can be concluded that treadmill training is beneficial for children with CP. PMID- 19874076 TI - Increased mortality among individuals with chronic widespread pain relates to lifestyle factors: a prospective population-based study. AB - PURPOSE: Widespread chronic pain has been related to disability and loss of quality of life, but in a few epidemiological studies also to increased mortality. The aim of this study was to further investigate the relationship between chronic pain, lifestyle factors and all cause mortality. METHODS: A random sample of an adult (age 25-74) Swedish population (n = 1609) responded to a comprehensive questionnaire on pain, other symptoms, lifestyle, work and socioeconomic factors in 1988. Mortality data for this cohort between 1988 and 2002 were analysed. Survival analysis (Kaplan-Meier) and Cox proportional regression were used to study initially reported factors influencing survival. RESULTS: Individuals with widespread chronic pain showed an increased mortality risk (hazard ratio, HR = 1.95, CI: 1.26-3.03) compared to the group without chronic pain. Death due to cardiovascular disease accounted for the increased mortality. Adjustment for lifestyle factors eliminated the excess risk. CONCLUSIONS: Increased mortality among individuals with widespread chronic pain is related to factors like smoking, sleep disturbances and low physical activity. The result emphasises the importance of including lifestyle factors in a cognitive-behavioural rehabilitation process. It remains to be shown whether health promotion activities aimed at lifestyle could change mortality among individuals with chronic pain. PMID- 19874077 TI - The usability of a modified Astrand bicycle test to assess the aerobic capacity in patients with musculoskeletal pain and healthy controls. AB - PURPOSE: The aim of this study was to assess the usability of a modified Astrand bicycle test in subjects with musculoskeletal pain disorder (MSPD) and healthy controls. METHODS: In a random cross-over design, 31 subjects with a MSPD who have been referred to rehabilitation medicine and 33 healthy subjects matched for age, gender, height and body weight, performed an Astrand bicycle test and a modified test with a time interval of 7 days. Drop-out rates, VO2max values (in mL/kg lean body mass (LBM) min(-1)), intraclass correlation coefficients (ICCs) and critical difference (Bland-Altman plots) for both tests within each group of subjects were compared. RESULTS: The drop-out rate in both tests for the MSPD group was comparable, and mainly caused by pain, fatigue or breathlessness. Compared with the modified version, the Astrand test showed higher VO2max-scores: 4.83 mL/kg LBM min(-1) (9.96%) in the MSPD group and 3.5 mL/kg LBM min(-1) (5.57%) in the healthy group. ICCs were 0.79 and 0.87 and the limits of agreement were 8.5 mL/kg LBM min(-1) (15.9%) and 10.2 mL/kg LBM min(-1) (18.1%), respectively. CONCLUSION: The usability of the modified test is acceptable, as well as in healthy individuals as subjects suffering from MSPD being referred to rehabilitation medicine. However, a slight under estimation of VO2max with the modified test has to be taken into account. PMID- 19874078 TI - Perception of multimodal cognitive treatment for people with chronic widespread pain--changing one's life plan. AB - PURPOSE: The aim of this study was to gain a deeper understanding of chronic widespread pain patients' perception of a multimodal treatment with a cognitive approach. METHODS: A reformulated grounded theory study based on interviews with 16 participants in the programme was conducted at the end of a 6-month treatment period. RESULTS: The result describes a conceptual model of the informants' perception of the treatment. The core category 'changing one's life plan' comprised of three categories: 'changing one's perception of life', 'depending on support' and 'managing one's life'. Changing one's perception of life could be deep and overwhelming 'overall life changes' or more superficial 'life adjustments'. Support by health professionals and the patient group were of importance. At the end of the rehabilitation program managing one's life was perceived as either 'reorientation' or 'stagnation'. The informants who experienced overall life changes achieved reorientation with support by others, while those who experienced life adjustments did not change their way of managing one's life to any great extent. CONCLUSION: The core category changing one's life plan included the categories; changing one's perception of life, depending on support and managing one's life. Informants experiencing overall life changes were more likely to achieve reorientation than those who experienced life adjustments. PMID- 19874079 TI - Perceptions of health professionals about effective practice in falls prevention. AB - PURPOSE: Falls prevention is a practice context with a rapidly expanding evidence base. However, little is known about the implementation of this evidence into practice by health professionals. This study aimed to explore how falls prevention evidence is applied in practice internationally by health professionals working in the homes of older people, and to identify the perceived barriers and effective strategies in implementing falls prevention programs. METHOD: A qualitative study design using a grounded theory approach was selected. Data were collected via focus groups or individual, semi-structured interviews with 50 health professionals from Australia, the UK and Canada. All participants visited older people in their homes as part of their usual practice. Data analysis used the constant comparative method. RESULTS: Three themes emerged from the data: (i) client experiences of falls prevention, (ii) professional skills and clinical reasoning in falls prevention and (iii) service issues in falls prevention. CONCLUSIONS: The complexity of delivering an evidence-based, multi disciplinary falls prevention intervention that is acceptable to clients was described by participants. Challenges were identified in applying the evidence according to the resources and experience of health professionals in the systems within which they work. PMID- 19874080 TI - Return-to-work experiences: prior to receiving vocational services. AB - PURPOSE: Injured workers can experience a myriad of difficulties while attempting workplace reintegration and, in some cases, problems encountered result in workers being unable to take up employment opportunities and/or maintain employment gains. This project aimed to discover what injured workers report as being the reason for their not pursuing and/or leaving post-injury work opportunities. METHODS: Semi-structured interviews inquiring about participant's (N = 150) return-to-work experiences following an occupational injury resulting in an impairment that limited their ability to perform their past work. RESULTS: Findings indicate that although reasons cited for the loss of employment gains included physiological body function, the ability to perform work-related tasks and actions and personal factors, the most commonly referenced barriers by far were environmental in nature. Depending on where the worker was within the return to-work process, the regularity with which each of the types of environmental factors was mentioned varied considerably. CONCLUSIONS: The finding that environmental factors are considered the most common stumbling blocks is positive in that these are arguably some of the most amenable to intervention. PMID- 19874081 TI - A Rasch-based validation of a short version of ABILHAND as a measure of manual ability in adults with unilateral upper limb amputation. AB - PURPOSE: To evaluate the measurement properties of ABILHAND (a generic measure developed to assess functioning in people with upper limb impairments) when used in adults with unilateral upper limb amputation (ULA). METHODS: A convenience sample of 72 adults who had unilateral ULA and completed rehabilitation at the Institute for Rehabilitation in Ljubljana at least 1 year prior to the study. They filled in the ABILHAND questionnaire. Rating scale analysis (Rasch model) was used to evaluate functioning of the rating scale categories, the validity of the measure by examining fit of the items to the latent trait and the hierarchy of item difficulties compared with expectations of the construct. RESULTS: Rasch analysis allowed us to improve ABILHAND by rescoring to reduce the response categories from 5 to 4, and identifying 22 of 46 items that are useful to measure upper limb function in people with ULA. The results indicate that high confidence can be placed in the consistency of both person-ability and item-difficulty estimates. CONCLUSIONS: This revised ABILHAND for people with unilateral ULA (ABILHAND-ULA 1.0) is a promising instrument for measuring their degree of manual functioning. PMID- 19874082 TI - Living and doing with chronic pain: narratives of pain program participants. AB - PURPOSE: This study aimed to explore factors which predicated successful long term pain management for people who had attended a cognitive-behavioural-based pain management program (PMP) in regional Australia. METHOD: This study used qualitative methods based on analysis of narratives. Fifteen people (11 women and four men), who attended the PMP in 2002 and 2003, agreed to participate in two in depth interviews with a narrative focus in 2005. Their ages ranged from 30-65 years. Interview transcripts were analysed thematically. FINDINGS: Themes that emerged from the interviews were the meanings and beliefs participants had attributed to their pain at the time of the program and after program completion (i.e. being ready to do the program and acceptance or non-acceptance of the long term nature of their pain). It also identified the strategies that some participants used and continued to apply in their daily lives (i.e. using pacing strategies and re-engaging in valued routines and tasks). CONCLUSION: The findings suggested that the ability to adopt positive meaning attributes and use a variety of strategies was related to those participants who were successful in their ongoing pain management. The importance of these factors should be considered for those attending chronic pain programs. PMID- 19874083 TI - Identification of international classification of functioning, disability and health relevant categories to describe functioning and disability of patients with myasthenia gravis. AB - PURPOSE: To describe functioning and health of patients with myasthenia gravis (MG) and to identify which are the most common problems patients encounter, by using the international classification of functioning, disability and health (ICF). METHOD: Adult patients with MG were recruited at C. Besta Neurological Institute. The ICF checklist was administered in individual sessions. Categories were identified as relevant if they were reported as a problem by more than 30% of patients (within activities and participation, the threshold was counted on capacity qualifier). RESULTS: One hundred two patients were enrolled (mean age 47.2; inpatients were 29.4%, females 68.6%) and 54 ICF categories were selected: 14 body functions categories (26% out of total selected categories), 2 body structures (4%), 22 activities and participation categories (41%) and 16 environmental factors (29%). Environmental factors were essentially reported as facilitators. CONCLUSIONS: Twelve ICF categories, not contained in ICF core-sets for neurological condition, related to mobility, household and labour activities were identified. The ICF categories identified in this study are an useful guideline for clinicians and researchers, for monitoring interventions and follow up of clinical conditions on a broad set of functional areas, and for developing ICF-based assessment tools for patients with MG. PMID- 19874084 TI - The effects of neuromuscular electrical stimulation on clinical improvement in hemiplegic lower extremity rehabilitation in chronic stroke: a single-blind, randomised, controlled trial. AB - OBJECTIVE: In this study, the effectiveness of neuromuscular electrical stimulation (NMES) was evaluated in lower extremity rehabilitation in patients with chronic stroke. METHOD: The study enrolled 40 patients with chronic stroke. Twenty patients each were assigned to the treatment group and the control group. All patients received a conventional rehabilitation program for a 4-week period. In addition to this rehabilitation program, patients in the treatment group received NMES treatment for hemiplegic foot dorsiflexor muscles for 4 weeks, 5 days a week. The sessions were performed as one session per day and added to a total of 20 sessions. Clinical parameters were evaluated before and after the treatment. RESULTS: Pre-treatment and post-treatment evaluations showed a significant increase in ankle dorsiflexion and a significant decrease in the level of spasticity in the treatment group (p < 0.05); however, there were no significant differences in the control group between the pre-treatment and post treatment measures. Although Brunnstrom Stage, Rivermead leg and trunk score and Functional Independence Measurement motor subscore showed a significant improvement in pre- and post-treatment comparisons for both groups, the treatment group's scores were significantly higher than the control group (p < 0.05). Functional Ambulation Categories showed a significant improvement in both groups following the treatment; however, there was no significant difference between the two groups (p > 0.05). CONCLUSIONS: Use of NMES in hemiplegic foot dorsiflexion can contribute to the clinical improvement of patients when used in combination with rehabilitation programs. PMID- 19874085 TI - Not a process of simple vicariousness, the differentiation of human adipose derived mesenchymal stem cells to renal tubular epithelial cells plays an important role in acute kidney injury repairing. AB - The recent findings indicate that under conditions of severe tubular injuries, transplantation of mesenchymal stem cells (MSCs) may be a promising treatment in acute kidney diseases; nevertheless, the underling mechanism is still under debate. To investigate the differentiation characteristics and the role of MSCs in renal tubular injury, human adipose-derived MSCs (hAD-MSCs) were transplanted into ischemia-reperfusion (I/R) kidneys in C57BL/6 mouse model. Results showed that hAD-MSCs were able to differentiate toward renal tubular epithelium at an early stage of injuries. The differentiated donor cells replaced the vacant space left over by the dead cells, contributed to maintenance of structural integrity and proceeded to a subsequent tissue repair process. Furthermore, MSCs as supportive cells may promote repair via secreting cytokines. The differentiation and replacement of MSCs at an extremely early stage play important roles for the subsequent self-repair and -renewal of functional cells. Direct differentiation of MSCs, as an important mechanism of injured kidney repair, warrants further investigation. PMID- 19874087 TI - Toxicology and human health assessment of decabromodiphenyl ether. AB - We evaluated the available pharmacokinetic data and human and animal toxicity data for 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) (CASRN 1163 19-5) with the objective of deriving a reference dose (RfD) based on the best available science. The available studies for deriving an RfD were first screened using the Klimisch criteria and further evaluated using the United States Environmental Protection Agency's general assessment factors for data quality and relevance (i.e., soundness, applicability and utility, clarity and completeness, uncertainty and variability, and evaluation and review). The chronic 2-year dietary feeding study conducted by the United States National Toxicology Program ( NTP, 1986 , Technical Report Series No. 309) was selected for RfD derivation. Hepatocellular degeneration in male rats was chosen as the critical endpoint in the development of an RfD. For dose-response characterization, we applied benchmark-dose modeling to animal data and determined a point of departure (the 95% lower confidence limit for a 10% increase in hepatocellular degeneration) of 419 mg/kg-day for oral exposures. Based on the similar pharmacokinetic characteristics of BDE-209 across species, this value was converted to a human equivalence dose of 113 mg/kg-day by applying a dosimetric adjustment factor based on body weight scaling to the (3/4) power. An oral RfD of 4 mg/kg-day was calculated by using a composite uncertainty factor of 30, which consisted of 10 for intraspecies uncertainty, 3 for interspecies uncertainty (i.e., 3 for toxicodynamics x 1 for toxicokinetics), and 1 for deficiencies with the database. We consider the RfD to be adequately protective of sensitive subpopulations, including women, their fetuses, children, and people with hepatocellular diseases. PMID- 19874090 TI - The Communication Attitude Test (CAT-S): normative values for 220 Swedish children. AB - BACKGROUND: The risk of developing a negative attitude to communication as a consequence of having a speech disorder has been in focus for decades in research concerning fluency disorders in relation to both children and adults. The Communication Attitude Test (CAT), which was created to measure children's attitudes towards their own communication, has been widely used. Research has shown that children who stutter have a significantly more negative attitude to their own communication than normal-speaking children and preliminary results show a similar picture in children with other types of speech disorders. However, the setting for obtaining data on normal-speaking children often differs from that on children with speech disorders. In order to make a significant interpretation of results from children with a speech disorder, comparable data on normal-speaking children are needed. AIMS: The main purpose of this study was to obtain norm values for the Swedish version of the test (CAT-S) and examine possible differences related to age, sex or small town/big city. A second aim was to investigate some aspects of reliability, such as internal consistency, and validity in terms of item analysis as well as a qualitative analysis of the answers to the different items. In addition, group setting was compared with individual setting for the test procedure. METHODS & PROCEDURES: CAT-S was completed in a group setting by 220 normal-speaking children aged 7-15 years and by an additional group of 35 normal-speaking 10-year-old children who completed the test individually. OUTCOMES & RESULTS: The 220 Swedish children had a mean score of 6.05 (a slightly higher mean score have been found in other countries, i.e. Belgium = 7.05 and USA = 8.24). The 7-year-olds had a significantly higher mean score than children at the other ages, except for the 15-year-olds. No other differences were found related to age, sex or size of community. The aspects of reliability and validity investigated for the CAT-S were satisfactory. Furthermore, there was no significant difference between the groups of 10-year olds objected to different test procedures. CONCLUSIONS & IMPLICATIONS: The norm values of CAT-S could be used for comparison of scores from Swedish children with speech disorders. The CAT-S is easy to administer and could be used either in a group setting for research purpose or individually at the clinic. PMID- 19874086 TI - Wnt inhibitors Dkk1 and Sost are downstream targets of BMP signaling through the type IA receptor (BMPRIA) in osteoblasts. AB - The bone morphogenetic protein (BMP) and Wnt signaling pathways both contribute essential roles in regulating bone mass. However, the molecular interactions between these pathways in osteoblasts are poorly understood. We recently reported that osteoblast-targeted conditional knockout (cKO) of BMP receptor type IA (BMPRIA) resulted in increased bone mass during embryonic development, where diminished expression of Sost as a downstream effector of BMPRIA resulted in increased Wnt/beta-catenin signaling. Here, we report that Bmpr1a cKO mice exhibit increased bone mass during weanling stages, again with evidence of enhanced Wnt/beta-catenin signaling as assessed by Wnt reporter TOPGAL mice and TOPFLASH luciferase. Consistent with negative regulation of the Wnt pathway by BMPRIA signaling, treatment of osteoblasts with dorsomorphin, an inhibitor of Smad-dependent BMP signaling, enhanced Wnt signaling. In addition to Sost, Wnt inhibitor Dkk1 also was downregulated in cKO bone. Expression levels of Dkk1and Sost were upregulated by BMP2 treatment and downregulated by Noggin. Moreover, expression of a constitutively active Bmpr1a transgene in mice resulted in the upregulation of both Dkk1 and Sost and partially rescued the Bmpr1a cKO bone phenotype. These effectors are differentially regulated by mitogen-activated protein kinase (MAPK) p38 because pretreatment of osteoblasts with SB202190 blocked BMP2-induced Dkk1 expression but not Sost. These results demonstrate that BMPRIA in osteoblasts negatively regulates endogenous bone mass and Wnt/beta catenin signaling and that this regulation may be mediated by the activities of Sost and Dkk1. This study highlights several interactions between BMP and Wnt signaling cascades in osteoblasts that may be amenable to therapeutic intervention for the modification of bone mass density. PMID- 19874091 TI - Comprehension of metaphor and metonymy in children with Williams syndrome. AB - BACKGROUND: Figurative language, such as metaphor and metonymy, is very common in daily language use. Its underlying cognitive processes are sometimes viewed as lying at the interface of language and thought. Williams syndrome, which is a rare genetic developmental disorder, provides an opportunity to study this interface because individuals with this disorder have relative strengths in vocabulary and syntax against a background of low general cognitive ability. Few studies have investigated metaphor comprehension in Williams syndrome and none has investigated metonymy. AIMS: This is the first study to investigate metaphor and metonymy comprehension in Williams syndrome and to compare their performance with a group of typically developing children. METHODS & PROCEDURES: Ten children with Williams syndrome were compared with eleven typically developing children in a novel metaphor-metonymy comprehension task. Cross-sectional trajectory analyses were used to compare the development of metaphor and metonymy using a child friendly story picture task. Trajectories were constructed linking task performance either to chronological age or to measures of mental age (receptive vocabulary, visuospatial construction). OUTCOMES & RESULTS: The performance of children with Williams syndrome was significantly poorer than the typically developing group. The comprehension of metonyms was in line with receptive vocabulary, but comprehension of metaphors fell below this level. CONCLUSIONS & IMPLICATIONS: Metonyms may be part of vocabulary and treated as synonyms in Williams syndrome, while metaphor engages additional cognitive mechanisms outside language that develop atypically in this disorder. Despite earlier reports that emphasize good language skills, the Williams syndrome language system shows anomalies compared with typical development. PMID- 19874093 TI - The latest "cheap high" for teens. PMID- 19874094 TI - Managing weight in persons living with severe mental illness in community settings: a review of strategies used in community interventions. AB - Although several published reviews have summarized the results of behavioral weight management interventions for persons with severe mental illness, little attention has been paid to the interventions themselves, despite the breadth of intervention strategies that have been examined in published trials. This study identified and systematically described 16 behavioral weight management interventions for community-dwelling persons with severe mental illness. Intervention content and delivery features that were considered included (a) approach to weight management; (b) theoretical constructs targeted to achieve behavior change; (c) diet, exercise, and/or self-regulation skills; (d) instructional strategies; and (e) intervention format including duration, intensity, and setting. Findings revealed modest, but sustained, weight loss. Individual and societal resources to address obesity among persons living with severe mental illness are limited. Further research is needed to identify the most effective and the most parsimonious interventions. PMID- 19874095 TI - Recognizing and addressing the stigma associated with mental health nursing: a critical perspective. AB - Negative and stigmatizing beliefs regarding mental health nursing discredit the valuable contributions of mental health nurses, but more importantly, these beliefs discredit the needs of people who access mental health care. The stigma associated with mental health nursing, however, has received little attention in the literature. In this article, the author explores the stigma associated with mental health nursing from a critical lens. Recommendations are proposed to address the stigma associated with mental health nursing and mental illness, concurrently, within nursing education. PMID- 19874096 TI - Sources of uncertainty: experiences of Alzheimer's disease. AB - Uncertainty is an inherent part of most illness experiences and Alzheimer's disease in particular is fraught with uncertainties, especially for the family. In an investigation of sources of uncertainty, 33 adult children with a parent diagnosed with probable Alzheimer's disease were interviewed. Participants described medical, personal, and social sources of uncertainty related to their parent's diagnosis. This research contributes to literature on uncertainty management and addresses the specific illness experiences of families coping with uncertainty related to Alzheimer's disease. Recommendations are made for further research that focuses on the ways family members are affected by illness. PMID- 19874097 TI - Disclosure of serostatus to sex partners among HIV-positive men and women in Hawaii. AB - The HIV epidemic in the United States is not abating, and sexual activity is the transmission-risk factor most frequently reported among those newly infected. Many HIV-positive persons have difficulty disclosing their serostatus to sex partners (SPs) and may not use condoms consistently. The aims of the research were to explore patterns of disclosure to SPs among HIV-positive men (N = 93) and women (N = 23) living in Hawaii, and to explore factors influencing disclosure and condom use. Using a survey design, participants were asked about their sexual activity during a three-month recall period, including detailed information for up-to-three most recent SPs. A variety of demographic, HIV-illness, self efficacy, and contextual variables were examined as potential factors influencing disclosure. A total of 278 SPs were reported with rates of disclosure and of condom use near 50% for both genders. Perceived self-efficacy (SE) for disclosure decision-making was associated with disclosure for both men and women. Not discussing a SP's serostatus was associated with nondisclosure for both men and women. Additional factors influencing disclosure for men included cocaine and marijuana use, and years since diagnosis. Being transgendered was associated with less disclosure, but the small sample size for women precludes generalization of findings. There was an association between disclosure and condom use for men but not for women. Nurses must routinely assess for client HIV transmission-risk behaviors, and encourage disclosure of serostatus to SPs. It is also essential to offer clients behavioral strategies that can enhance their intentions to use condoms. PMID- 19874098 TI - Hand hygiene compliance among health care staff and student nurses in a mental health setting. AB - Hand hygiene practice among health care workers is considered to be the single most effective method of preventing nosocomial infection in hospital settings. Infection control practices in psychiatric facilities are particularly challenging as hand hygiene protocols are specific to acute care facilities, areas where hands are visibly soiled, and when procedures are completed that may involve body fluid exposure. The inability to motivate and change the hand washing practices of health care workers suggests that hand washing behaviour is complex, involving individual beliefs and attitudes and institutional commitment and rigor. PMID- 19874099 TI - Attitudes of Jordanian mental health nurses toward mental illness and patients with mental illness. AB - The purpose of this study was to examine Jordanian mental health nurses' attitudes toward mental illness and patients with mental illness. A descriptive correlational design was utilized to collect data from 92 mental health nurses in Jordan. Data was collected on nurses' attitudes toward mental illness and patients with mental disorder and their satisfaction with nursing care delivery. The Jordanian mental health nurses who participated in this study had negative attitudes toward mental illness and toward patients with mental disorders. About 60% of the mental health nurses had perceived patients with mental illness to be dangerous, immature, dirty, cold hearted, harmful, and pessimistic. In only two descriptions-being polite and adult-did nurses have positive perception about patients with mental illness. Mental health nurse were not satisfied with nursing care delivery. More than 70% of nurses were proud to be a mental health nurse. Age and gender were significant influential factors in forming the nurses' attitudes or satisfaction. Immediate intervention is needed to improve the quality of patient care provided by mental health nurses. PMID- 19874100 TI - Construction of an instrument to evaluate nurses' decision making in relation to the use of restraint in acute care psychiatry. AB - Use of physical restraint in acute care psychiatry has been, and continues to be, a controversial issue. For this reason, a study was conducted in 1996 that examined nurses' decision making related to the use of physical restraint with aggressive psychiatric patients. An instrument, the Moylan Assessment of Progressive Aggression Tool (MAPAT), was developed for this purpose. Information relating to this instrument has not been previously published. It is currently in use in an ongoing research study by the author. A description of the process of the development of the MAPAT is provided here, along with the validity and reliability of the instrument, and implications for potential use in research, training, and education. PMID- 19874101 TI - Family and community responses to mental illness. PMID- 19874102 TI - Personal health records: protecting behavioral health consumers' rights. PMID- 19874103 TI - Do the causes of psychotic symptoms matter? AB - There needs to be a better understanding of how psychoses and other serious mental illnesses develop. They do not develop in isolation but are connected with subsequent events that impose themselves on the individual. Predispositions, via heredity, starts the process, but it is what happens subsequently in the environment that leads to interactions that are dynamic. Hence knowledge into what causes psychosis is not helpful when treating the condition. An analysis of the remitting symptoms leading to the treatment of the symptoms offers a better chance of remedying the condition. There is a need for as early an intervention as possible, ideally, if possible, avoiding the use of medication and concentrating on the use of CBT or CT. PMID- 19874105 TI - Uncorrected refractive errors, presbyopia and spectacle coverage: results from a rapid assessment of refractive error survey. AB - PURPOSE: To investigate the prevalence of uncorrected refractive errors, presbyopia and spectacle coverage in subjects aged 15-50 years using rapid assessment methodology in the Mahabubnagar district of Andhra Pradesh, India. METHODS: A population-based cross sectional study was conducted using cluster random sampling to enumerate 3,300 subjects from 55 clusters. Unaided, aided and pinhole visual acuity was assessed using a LogMAR chart at a distance of 4 meters. Near vision was assessed using N notation chart. Uncorrected refractive error was defined as presenting visual acuity worse than 6/12 but improving to at least 6/12 or better on using a pinhole. Presbyopia is defined as binocular near vision worse than N8 in subjects aged more than 35 years with binocular distance visual acuity of 6/12 or better. RESULTS: Of the 3,300 subjects enumerated from 55 clusters, 3,203 (97%) subjects were available for examination. Of these, 1,496 (46.7%) were females and 930 (29%) were > or = 40 years. Age and gender adjusted prevalence of uncorrected refractive errors causing visual impairment in the better eye was 2.7% (95% CI, 2.1-3.2%). Presbyopia was present in 690 (63.7%, 95% CI, 60.8-66.6%) subjects aged over 35 years. Spectacle coverage for refractive error was 29% and for presbyopia it was 19%. CONCLUSIONS: There is a large unmet need for refractive correction in this area in India. Rapid assessment methods are an effective means of assessing the need for services and the impact of models of care. PMID- 19874106 TI - A population survey of the penetrance of contact lens wear in Australia: rationale, methodology and results. AB - PURPOSE: A population based, cross-sectional telephone survey was conducted to estimate the total penetrance of contact lens wear in Australia. METHODS: A total of 42,749 households around Australia were randomly selected from the national electronic telephone directory based on postcode distribution. Before contact was attempted, letters of introduction were sent. The number of individuals and contact lens wearers in each household was ascertained and lens wearers were interviewed to determine details of lens type and mode of wear using a structured questionnaire. RESULTS: Of households contacted, 59.2% (19,171/32,405) agreed to participate. Response rates were only marginally higher amongst households that first received a letter of introduction. In these households, 35,914 individuals were identified, of which, 1,798 were contact lens wearers. The penetrance of contact lens wear during the study period was 5.01% (95% CI: 4.78-5.24). Soft hydrogel lenses had the largest penetrance in the community, (66.7% of all wearers), however, their market share decreased significantly over the study period with increased uptake of newly introduced lens types. CONCLUSIONS: The penetrance of contact lens wear concurs with market estimates and equates to approximately 680,000 contact lens wearers aged between 15 and 64 years in Australia. The low response rate obtained in this study highlights the difficulty in contemporary use of telephone survey methodology. PMID- 19874107 TI - Disparities in access to medical care for individuals with vision impairment. AB - PURPOSE: We investigated the relationship between blindness and vision impairment and access to medical care. METHODS: Pooled data from the Medical Expenditure Panel Survey (MEPS) years 2002-2004 were used to identify non-institutionalized individuals over the age of 40 with either self-reported blindness, vision impairment, or no vision impairment (n = 40,643). Differences in access to care measures by vision status were assessed, after adjusting for the complex sampling design of the MEPS, using either two-sided z-tests or two-sided t-tests. RESULTS: Individuals with blindness and vision impairment report having more access problems related to cost of care, availability of insurance coverage, transportation issues, and refusal of services by providers, although they do not report lower rates of having a usual source of care compared to those without vision impairment. CONCLUSIONS: The results suggest that access to care for individuals with blindness and vision impairment is problematic, for reasons that are amenable to policy interventions. PMID- 19874108 TI - Distribution pattern of lens opacity among a rural population in South Western Nigeria. AB - PURPOSE: To determine prevalence of the morphological types of age-related lens opacity in Southwestern Nigeria as part of need assessment survey towards planning an eye health care service. METHOD: Multistage cluster sampling was used in selecting a representative cross-sectional sample of persons 50 years of age or older among the residents of the rural wards in Akinyele Local Government Area in southwestern Nigeria. Lens opacity was graded using the World Health Organization cataract grading system. RESULTS: One thousand two-hundred persons were recruited for the survey and 1031 (85.9%) had grading of lens opacity. The mean age of the participants was 64.9 years and 51.1% were male. Five hundred and ninety persons had definite lens opacity (crude prevalence rate 57.2%; 95% Confidence interval [CI] 54.1-60.3) (standardized prevalence 47.0%; 95% confidence interval 46.7-47.3). The prevalence for participants aged 70 years and above (82.5%; 95% CI 78.2-86.3) was three times more than for participants aged 50-59 years (29.2%; 95% CI 24.2-34.6). Nuclear opacity was the most prevalent type of lens opacity (20.9%; 95% CI 18.4-23.5). Sixty percent of the grade 3 lens opacity was found among participants aged 70 years and above. CONCLUSION: This is the first population-based survey on prevalence of lens opacity subtype in this West Africa subregion. The prevalence of lens opacity in the rural Akinyele local government is high. Nuclear sclerosis was the most prevalent form among this rural population. PMID- 19874109 TI - Cataract symptom score questionnaire: Rasch revalidation. AB - PURPOSE: The 5-item Cataract Symptom Score (CSS) was developed using classical test theory to determine appropriate timing for cataract surgery, its outcomes, and whether the symptoms included bother cataract patients. The purpose of this study was to investigate the psychometric properties of the 5-item CSS using Rasch analysis. METHODS: Responses from 113 patients awaiting cataract surgery to the 5-item CSS (bothered by double or distorted vision, glare or halos, blurry vision, colors looking different and worsening of vision) were subjected to Rasch analysis. The use of response categories (threshold order), ability of CSS to discriminate between participants' severity of symptoms (person separation, recommended minimum value 2.0), matching of item difficulty to severity of symptoms (targeting), and ability of items to measure a single construct (unidimensionality) were investigated. RESULTS: Participants used the response categories as intended. However person separation (1.74) was inadequate, suggesting that the CSS could differentiate only between two groups of participants by their symptoms. Furthermore the CSS was poorly targeted for our population, as the majority of our participants were not bothered by symptoms in the CSS. All items fit the single construct, implying that the CSS is a unidimensional measure of cataract symptoms. CONCLUSIONS: The CSS is unable to discriminate people with cataract. This problem could be fixed by adding additional questions, but a superior approach may be to create an item bank of cataract symptoms questions, including those of the CSS, and utilize computer adaptive testing for measurement. PMID- 19874110 TI - Age-related macular degeneration in a screened South Korean population: prevalence, risk factors, and subtypes. AB - PURPOSE: To identify the prevalence, risk factors, and subtypes of age-related macular degeneration (AMD) in a screened South Korean population. METHODS: A total of 10,890 participants (aged 50-92) who underwent a health check-up at Kangbuk Samsung Hospital from January to December 2006 were included. Fundus photographs and systemic risk factors were assessed. Subtype frequencies of neovascular AMD were recorded according to angiograms. AMD was defined in accord with the international classification and grading system. Logistic regression analyses were performed to identify risk factors for AMD. RESULTS: The mean age of the 10,890 participants was 57.2 +/- 6.3 years (50-92 years), and 56.2% were men. The age-gender-adjusted prevalence of early AMD was 5.07%. Multiple logistic regression analysis showed that age (OR per 10-year increment, 2.22) and high blood pressure (adjusted OR: 1.35) were independent risk factors for early AMD. The age-gender-adjusted prevalence of late AMD was 0.34%. Only age was significantly associated with late AMD. Of 9 exudative AMD patients who received fluorescein angiography or indocyanine green angiography, 6 eyes (66.7%) showed choroidal neovascularization, 2 eyes (22.2%) had polypoidal choroidal vasculopathy (PCV), and 1 eye (11.1%) had retinal angiomatous proliferation. CONCLUSION: In this study, the prevalence of early AMD was similar to other studies though the prevalence of late AMD was low. High blood pressure as well as age was a risk factor of early AMD. South Koreans may have a higher prevalence of PCV than white populations. These findings provide preliminary information for further investigation of AMD in South Koreans. PMID- 19874111 TI - Children with low literacy and poor stereoacuity: an evaluation of complex interventions in a community-based randomized trial. AB - PURPOSE: To assess, among children with low literacy and poor stereoacuity, the efficacy of two intervention programs on child vision and education compared to a control program. METHODS: Eighty-eight children aged 8 to 13 years who had reading problems, and demonstrated poor stereoacuity as measured by the Titmus stereocircle test (> 100 seconds arc) or computerized assessment were randomized to one of two intervention programs: Lawson vision or Phono-Graphix, or a control group: Parental Literacy Support. Vision (Lang test, visual acuity, convergence insufficiency symptom survey) and education assessments (Woodcock Reading Mastery Tests-Revised) were conducted at baseline, intervention end (10 weeks), and 36 weeks. Analysis used intention to treat multi-level models. RESULTS: Compared to the parental literacy support group, convergence insufficiency symptoms were reduced 36 weeks post-randomization amongst those receiving the Lawson orthoptic intervention (mean difference -5.55; 95% confidence interval (CI): -11.1 to 0.05, P < 0.05). Stereoacuity, measured by the Lang test, improved for both the Lawson and Phono-Graphix interventions compared to the parental literacy support group (-1.01; 95% CI: -1.6 to -0.4, P = 0.001, and -0.77; 95% CI: -1.4 to -0.2, P = 0.01). At the 36 week follow-up assessment, word identification had also improved for the Lawson and Phono-Graphix groups but other educational outcomes did not improve. CONCLUSION: A formal randomized control trial was feasible in this setting. Intervention among children with poor stereoacuity and low literacy produced small improvements in stereopsis and convergence insufficiency symptom scores. Further randomized control trials should be conducted to clarify the role of orthoptic intervention on literacy in selected child populations. PMID- 19874114 TI - Erymildbraedin A and B, two novel cytotoxic dimethylpyrano-isoflavones from the stem bark of Erythrina mildbraedii: evaluation of their activity toward endocrine cancer cells. AB - Two new dimethylpyrano-isoflavones, named erymildbraedin A (4) and B (5), were isolated from the stem bark of the Cameroonian medicinal plant Erythrina mildbraedii, along with four known ones, the linear congeners, scandenone (1), erysenegalinsein M (2), 5,4'-dihydroxy-2'-methoxy-8-(3,3-dimethylallyl)-2'',2'' dimethylpyrano[5,6:6,7]isoflavone (3), and the angular isoflavone eryvarin B (6), and two other compounds, fraxidin and scoparone. Their structures were elucidated by the usual spectroscopic methods and isoflavone effects on the growth of human breast, prostate, and endometrial adenocarcinoma cells were determined. Isoflavones 1, 3, and 6 strongly inhibited the growth of all three cell lines, supporting the notion that a non-oxidized isoprenyl group at C-8 is requisite for cytotoxic activity. PMID- 19874115 TI - Why acetylcholinesterase reactivators do not work in butyrylcholinesterase. AB - The pyridinium oxime therapy for treatment of organophosphate poisoning is a well established, but not sufficient method. Recent trends also focus on prophylaxis as a way of preventing even the entrance of organophosphates into the nervous system. One of the possible prophylactic methods is increasing the concentration of butyrylcholinesterase in the blood with the simultaneous administration of butyrylcholinesterase reactivators, when the enzyme is continuously reactivated by oxime. This article summarizes and sets forth the structural differences between butyrylcholinesterase and acetylcholinesterase, essential for the future design of butyrylcholinesterase reactivators. Butyrylcholinesterase lacks the reactivator aromatic binding pocket found in acetylcholinesterase, which is itself a part of the acetylcholinesterase peripheral anionic site. This difference finally renders the current acetylcholinesterase reactivators, when used in butyrylcholinesterase, non-functional. PMID- 19874116 TI - Pharmacokinetic parameters and a theoretical study about metabolism of BR-AEA (a salbutamol derivative) in rabbit. AB - In this study, we report the pharmacokinetics of 1-(4-di-hydroxy-3,5-dioxa-4 borabicyclo[4.4.0]deca-7,9,11- trien-9-yl)-2-(tert-butylamino)ethanol (BR-AEA). This compound was identified as a more potent beta(2) adrenoceptor (beta(2)AR) agonist than salbutamol. A sensitive and reproducible high-performance liquid chromatography (HPLC) method was used for determining the time-dependent BR-AEA concentration in healthy rabbit plasma. The pharmacokinetic parameters obtained are explained in relation to the compound's metabolism by sulfotransferases. For this purpose, docking simulations were carried out on SULT1A3, SULT1C1, and SULT1A1 3-D models using the Autodock 3.0.5 program. According to the HPLC results, t(1/2) = 2.36 +/- 0.18 h and K(e) = 0.32 +/- 0.02 h(-1) for BR-AEA in rabbit plasma. Thus, BR-AEA has a greater half-life compared with salbutamol (t(1/2) = 0.66 +/- 0.08 h). This could be due to the protection that the boronic acid moiety of BR-AEA offers to the hydroxyl groups that would otherwise be susceptible to sulfation when exposed inside the active site of the sulfotransferase. This could be due to the fact that BR-AEA has a high affinity for the side-chain hydroxyl groups of Ser and Tyr residues of the enzymes, which are located outside the active site. PMID- 19874117 TI - The current state of the art in high-resolution two-dimensional electrophoresis. AB - The study of the "proteomes" of human cells, tissues, and body fluids is a big challenge, and several highly sophisticated workflow approaches are pursued to achieve as comprehensive information as possible. Initially proteome analysis was exclusively based on the gel-based workflow, employing two-dimensional electrophoresis of protein extracts followed by mass spectrometry of the tryptic peptide digests of protein spots. Meanwhile several additional proteomics workflows are applied, which are mostly based on separation and analysis of tryptic peptides without separating the protein mixture. However, direct information on quantitative and qualitative changes of protein expressions can only be obtained by methods operating on the protein level, no other method can replace two-dimensional electrophoresis. In this review we compile the different techniques of high-resolution two-dimensional electrophoresis and their further developments to increase the degree of reliance of the method. PMID- 19874118 TI - Centurion syndrome: clinical presentation and surgical outcome. AB - PURPOSE: To describe the clinical signs and outcome of surgery in cases with Centurion syndrome and highlight the clinical presentation of this syndrome. METHODS: A retrospective review of records of patients with Centurion syndrome who underwent surgery between January 2002 and July 2007. The position of the punctum, nasal bridge prominence, Hertel exophthalmometry and the presence of inferiorly directed sharp angulation of the medial canthus was noted. The patients underwent anterior canthal tendon release, punctoplasty or medial conjunctivoplasty or a combination of these. RESULTS: Of the 13 cases, 10 had been treated medically elsewhere. The mean age of onset was 20.7 years. Most of the patients were male 10 (76.9%). A prominent nasal bridge was demonstrable in 9 (69.2%) patients and sharp inferior angulation of the medial canthus, the 'beak' sign was present in 9 (69.2%) cases. Anterior canthal tendon release alone was performed in 4 patients, in combination with punctoplasty in 5 and with conjunctivoplasty in 4. Watering resolved in 10 patients. 3 patients who had a combination of anterior canthal tendon release and punctoplasty had persistent but asymptomatic epiphora. DISCUSSION: Centurion syndrome is characterised by the abnormal anterior insertion of the medial canthal tendon with displacement of the punctum out of the lacrimal lake. Most cases present with unexplained watering. Surgical management by anterior canthal tendon release with or without conjunctivoplasty or lower lid retractor plication is usually successful. PMID- 19874119 TI - Rupture of an aneurysm of the persistent trigeminal artery presenting as a carotid-cavernous sinus fistula. AB - A 62-year-old Caucasian female presented with spontaneous right-sided eye pain, chemosis and ophthalmoloplegia. A right carotid-cavernous sinus fistula was discovered and successfully treated with transvenous introduction of Guglielmi detachable coils. In addition to complete fistula occlusion, follow-up angiography 6 weeks post-treatment demonstrated the presence of a patent persistent trigeminal artery previously hidden by the caliber of the carotid cavernous sinus fistula. The spontaneous nature of the presentation and the proximity of the persistent trigeminal artery to the site of coil embolization suggest spontaneous rupture of a persistent trigeminal artery aneurysm as cause of the fistula. Current literature on this finding is discussed here, demonstrating that an aneurysm of the persistent trigeminal artery leading to carotid-cavernous sinus fistula formation is rare. Furthermore, the present case is the first report of its kind in world ophthalmology literature. PMID- 19874120 TI - An oculoplastic use for the temporalis muscle flap. AB - PURPOSE: To report a novel method of repairing a large periorbital defect with exposed bone, using a pedicled temporalis muscle flap and split thickness skin graft. METHODS: Interventional case note review with clinical photographs, computerised tomography (CT) imaging, intra-operative photographs and histology. RESULTS: A 77-year-old man presented with an extensive neglected ulcerating lesion extending from the left lateral canthus to the tragus of the left ear. An incisional biopsy of the 15 cm lesion confirmed the clinical diagnosis of an invasive squamous cell carcinoma. A CT scan demonstrated the tumour depth and there were no infra-temporal fossa or intra-orbital extensions or associated lymphadenopathy. A wide surgical excision was performed which resulted perioperatively in a large area of exposed zygomatic and temporal bone. A pedicled temporalis muscle flap was rotated to cover the exposed bone and therefore allow placement of a split thickness skin graft. At 3 months' follow-up the graft is viable and the surgical rehabilitative result is satisfactory. CONCLUSIONS: A pedicled temporalis muscle flap and split thickness skin graft is a good one-stage reconstruction technique when faced with a large area of exposed bone. The temporalis muscle provides a suitable recipient site for a split skin graft and enhances its chances of survival. This technique, to our knowledge, had not previously been reported in the literature. PMID- 19874121 TI - Rare orbitocranial tumour in an adult. AB - A 35-year-old lady presented with recurrent episodes of painful right upper lid swelling and ptosis of 6 months' duration. The symptoms would subside with oral antibiotics and painkillers. She had also been undergoing treatment for 1 year for multiple painful osteolytic lesions in the long bones and axial skeleton for which no definite diagnosis had been made, despite several radiological and serological investigations having been performed. Computed tomographic scan showed a soft tissue lesion in the superolateral part of the right orbit with erosion of the adjacent bone. Lacrimal gland biopsy showed non-specific inflammatory changes. She was referred for full work-up to exclude lymphoma and metastasis. Magnetic resonance imaging revealed an enhancing soft tissue mass in the right anterior cranial fossa eroding the lateral orbital wall and extending into the orbit. Another mass encased the superior sagittal sinus. Bone marrow biopsy showed near total replacement of marrow cells by a round cell tumour. Immunohistochemical studies revealed that the tumour cells expressed neuron specific enolase and chromogranin. The pathological findings suggested a diagnosis of neuroendocrine tumour though neuroblastoma could not be unequivocally ruled out. A(131) I-metaiodobenzylguanidine scan showed no uptake. Radiologic studies suggested multiple bony metastases. No other site of primary tumour was found so there was a strong possibility of it being a primary orbito cranial neurogenic tumour. Neuroblastomas and neuroendocrine tumours are very rare in adults. The orbit is an unusual site for a primary of this nature. In addition, it is quite difficult to make a specific diagnosis in a less differentiated tumour. PMID- 19874122 TI - Undiagnosed squamous cell carcinoma of the forehead presenting as a Tolosa-Hunt syndrome. AB - Squamous cell carcinoma (SCC) is the second most common periocular skin cancer. We describe a case of invasive squamous cell carcinoma arising from actinic keratosis and causing orbital and intracranial invasion via perineural spread. Perineural invasion (PNI) is a known feature of SCC and very rarely basal cell carcinomas of the head and neck. A high degree of clinical suspicion is necessary to diagnose PNI. Varied clinical presentations have been described for this form of dissemination, including orbital apex syndrome as in our case. Prognosis is poor, with death resulting in over 50% of cases at 5 years. PMID- 19874123 TI - Double skull lymphangioma. Case report and review of the literature. AB - OBJECTIVE: It is still controversial whether lymphangiomas are a true entity or a combination of congenital venous and lymphatic malformations. Lymphangioma diagnosis is made on a multifactorial basis and surgery should provide cosmetic and functional preserving results. Only few multiple localization have been described in the literature and to our knowledge this is the first case reported on a double localization (orbital and temporal) in the skull. CASE DESCRIPTION: A 10-year-old girl was referred to our department with a rapidly enlarging subcutaneous mass in the right eyebrow and upper eyelid, displacing the eyeball and causing proptosis and diplopia that occurred synchronous with her menarche. A head MRI scan showed two distinct lesions, one into the orbit causing bony destruction and the other one in the sub-temporal area. The little girl underwent an open biopsy, suggesting the diagnosis of lymphangioma. Surgery through an anterior approach with total removal of both lesions was performed. Pathological examination disclosed a lesion consisting of multiple cysts with erythrocytes and lymphs, confirming the diagnosis. At a 6- and 12-months follow-up, the girl was clinically intact with normal ocular movements and a follow-up MRI showed no evidence of residual disease and/or recurrence. PMID- 19874124 TI - Topical mitomycin C as a postoperative adjunct to endonasal dacryocystorhinostomy in patients with anatomical endonasal variants. AB - PURPOSE: Unusual intranasal conditions may increase the rate of complications and affect success rate of endonasal dacryocystorhinostomy (DCR) surgery. The purpose of this study was to find the influence of endonasal abnormalities on outcome of endonasal DCR surgery and to find the role of topical mitomycin C (MMC) as a postoperative adjunct to endonasal dacryocystorhinostomy in these patients. METHODS: A total of 23 patients (19 males and 4 females) of bilateral chronic dacryocystitis in the age range of 18-60 years, having endonasal anatomical variants were included in this study. After endonasal DCR, the right side of nasal cavity was packed with 0.05% MMC nasal pack and left side of nasal cavity was packed with normal saline pack for 48 hours. During postoperative visits, the patients were checked for improvement in clinical symptoms and watched for complications including formation of adhesions and/or synechaie. The statistical association between endonasal pathologies and 3 dichotomous outcome variables (clinical features, adhesions, synechaie) was assessed by applying Fisher's Exact Test. RESULTS: Postoperative retention of nasal packs for 48 hours after endonasal DCR, did not cause any side effect in our patients. An improvement in clinical symptoms (23/23 = 100%) was seen in all the patients on side with 0.05% MMC soaked nasal pack, while 10/23 i.e., 43.47% patients did not show improvement in symptoms on side of saline nasal pack. Postoperatively, the MMC nasal pack side nasal cavity had a healthy nasal mucosa during the entire follow up, while the saline nasal pack side nasal cavity had synechiae in 15/23 (65.2%) patients and adhesions in 15/23 (65.2%) patients. In our study, none of the anatomical endonasal variants had a statistically significant association with either formation of adhesion or formation of synechiae, as the p-value was > 0.05 in all these instances. CONCLUSIONS: The patients with endonasal anatomical variants have a higher incidence of complications like formation of adhesions and synechaie after endonasal DCR than other patients. Topical MMC is safe and effective agent to decrease the rate of complications when used as an adjunct in endonasal DCR in patients with endonasal anatomical variants. PMID- 19874125 TI - Blindness from orbital varices: case report. AB - A 41-year-old woman presented with a 21-year history of a left orbital mass. She reported 3 distinct episodes of sudden proptosis, periorbital bruising, pain, nausea and vomiting with resulting stepwise deterioration in her vision. Her symptoms resolved spontaneously over several days, with the exception of loss in vision, which persisted. Examination was notable for ipsilateral enophthalmos in primary gaze. With Valsalva she developed proptosis. Magnetic resonance imaging (MRI) demonstrated a left orbital apex malformation consistent with a varix. She had no light perception on the left with end-stage optic atrophy. This case illustrates the severity of visual loss that can occur with orbital varices. PMID- 19874126 TI - Primary non-Hodgkins lymphoma of the lacrimal sac: mortality-related epiphora. AB - We report a case of primary non-Hodgkins lymphoma of the lacrimal sac in a 60 year-old Asian lady, who presented with persistent epiphora and recurrent medial canthal swelling. Primary lymphoma of the lacrimal sac is rare and it can be easily misdiagnosed. Delayed in diagnosis may be related to mortality. To minimize the risk of overlooking specific pathology it is important to assess the appearance of the lacrimal sac and its surrounding structures intraoperatively. Biopsy of the lacrimal sac is required in cases where specific pathology is suspected. PMID- 19874127 TI - Sebaceous carcinoma of the eyelid metastasizing to the lacrimal sac after 5 years. AB - Eyelid sebaceous carcinoma metastasizing to lacrimal sac is rare. A 65 year old female underwent excision with 5 mm margins and Cutler-beard reconstruction for a nodulo-ulcerative mass showing eyelash loss in the middle third of the right upper eyelid. Histopathology confirmed it to be sebaceous carcinoma with uninvolved margins. Five years after primary excision, the patient presented with persistent epiphora and mass in the ipsilateral lacrimal sac region. Repeat excision biopsy and conjunctival map biopsy confirmed recurrent sebaceous carcinoma of the lacrimal sac. Thirteen months after adjuvant radiotherapy to the orbit, the patient is alive and well with no loco-regional recurrence. PMID- 19874128 TI - Successful medical treatment of blepharochalasis: a case series. AB - INTRODUCTION: Blepharochalasis describes recurrent attacks of idiopathic transient painless oedema in the adnexal tissue of the orbit with the most severe reaction in the skin and orbicularis region. This may produce permanent tissue changes associated with thinning of the eyelid skin. Previous reviews have concentrated on surgical correction of the excess skin and orbicularis created by the condition. There has, as yet, been no report of successful medical management. PATIENTS AND METHODS: We report here on 4 males and 2 females aged between 37 and 78 years. Systemic acetazolamide (initially 250 mg SR OD), was used in combination with a topical steroid (hydrocortisone cream). RESULTS: All 6 patients achieved relief of their symptoms, with decreased incidence of occurrence and duration of episode if not complete resolution. CONCLUSION: Oral Acetazolamide in combination with topical hydrocortisone provides effective relief of the periorbital oedema associated with blepharochalasis. In our short series, the cases were improved either with medical therapy alone or in combination with surgery. Relapses following surgery were diminished as a result of prior medical therapy. PMID- 19874129 TI - A case of conjunctival derived orbital dermoid cyst: case report. PMID- 19874130 TI - Human liver progenitor cell lines are readily established from non-tumorous tissue adjacent to hepatocellular carcinoma. AB - Non-tumorous liver tissue removed during surgery to resect hepatocellular carcinoma (HCC) is potentially a useful source of material from which cells, particularly liver progenitor/stem cells (LPCs), can be isolated to establish cell lines. The purpose of this study was to evaluate the applicability of the "plate-and-wait" method to derive LPCs from resections to remove HCC. Three independent non-tumorous liver samples from HCC resection and 3 samples from liver donors were used for LPC isolation. Staining for LPC markers, OV6, CK19, and EpCAM, in the above liver samples demonstrated staining in only 2 of the non tumorous samples. We isolated 2 human liver epithelial cell lines (HLECs) from these 2 samples. These HLECs were positive for general stem cell markers CD133, EpCAM, and Oct4. They expressed the liver progenitor cell markers OV6, CK14, and M2PK but not CK19. They also expressed the hepatocellular markers albumin, CK8, CK18, HNF4-alpha, and the drug-metabolizing gene CYP3A4. These cells accumulated glycogen, indocyanine green, and synthesized urea. They produced colonies in soft agar that showed anchorage-independent growth and their tumorigenic status was confirmed when they produced tumors following transfer to athymic nude mice. In contrast, the third non-tumorous tissue and 3 normal liver samples did not produce cell lines. This study establishes a correlation between the presence of LPCs in the source liver tissue and the ability to derive cell lines from these tissues. The phenotypic similarities between the LPCs and the HLECs suggest that a precursor-product relationship may exist between the 2 cell types. PMID- 19874131 TI - Molecular characterization of cultured adult human liver progenitor cells. AB - Hepatic progenitor cells hold great promise as a self-renewing cell source for cell-based regenerative therapies as well as in vitro pharmacological testing. There is a fundamental need to identify and characterize these cells with respect to discriminative marker genes especially those encoding cell surface proteins, which can be utilized for the identification and isolation of these progenitor cells. In this study, comparative global gene expression profiling was performed with two epithelial cell types isolated from human livers that showed progenitor characteristics (type 1 and 2 cells), two human embryonic stem cell lines H1 and H9, and with primary human hepatocytes. The analysis revealed that the transcriptome of type 1 cells is more similar to that of human embryonic stem cells than to that of human hepatocytes. Among the list of genes expressed in type 1 cells are cadherins (CDH3), tight junction proteins (CLDN4), receptors (DDR1), integrins (ITGB4), cell adhesion molecules (EpCAM/TACSTD1), cell surface proteins (CD133/PROM1, ANXA3, and CD24), and a gene encoding the multidrug resistance protein MRP4/ABCC4. Finally, we were able to localize type 1 progenitor cells in Canals of Hering and in cells of ductular reactions within sections of normal and diseased human liver using ANXA3 and CLDN4 antibodies. Our study confirms the progenitor identity of type 1 cells and identifies novel markers that could be used for further studies on their characteristics and isolation using marker-based cell sorting strategies. PMID- 19874133 TI - A novel and sensitive method for the detection of deoxynivalenol in food by time resolved fluoroimmunoassay. AB - In order to detect deoxynivalenol (DON) contamination in cereals, a time-resolved fluoroimmunoassay (TRFIA) was developed. By use of DON-bovine serum albumin (DON BSA), anti-DON antibody, and europium-labeled goat anti-rabbit antibody, this study established an indirect competitive DON-TRFIA. The sensitivity of this method was high, with the detection limit of 0.01 ng/mL. The tests showed the sensitivity was 0.1 microg/kg in cereals and 0.1 ng/mL in beer. Its detection range was 0.01-100 ng/mL. Within the detection range, the intra- and inter-batch CVs of the DON-TRFIA were 3.6% and 8.2%. Data obtained from corn and beer samples by TRFIA and ELISA were in good agreement. This assay did not cross-react with zearalenone (ZEN) and nivalenol (NIV) which commonly exists in corn. This study suggests that DON-TRFIA is a simple, fast and economic method for screening large quantities of samples, and has good prospects of application. PMID- 19874134 TI - Mechanistic studies on human N-acetylgalactosamine kinase. AB - N-Acetylgalactosamine kinase (GALK2) is a small molecule kinase from the GHMP family which phosphorylates N-acetylgalactosamine at the expense of ATP. Recombinant GALK2 expressed in, and purified from, Escherichia coli was shown to be active with the following kinetic parameters: Michaelis constant for ATP, 14 +/- 3 microM; Michaelis constant for N-acetylgalactosamine, 40 +/- 14 microM; and turnover number, 1.0 +/- 0.1 s(-1). The combination of substrate inhibition by N acetylgalactosamine and alpha-methylgalactopyranoside acting as an uncompetitive inhibitor with respect to ATP suggested that the enzyme has an ordered ternary complex mechanism in which ATP is the first substrate to bind. The effects of pH on the kinetic parameters provided evidence for ionizable residues playing a role in substrate binding and catalysis. These results are discussed in the context of the mechanisms of the GHMP kinases. PMID- 19874135 TI - 4-(4-morpholinophenyl)-6-arylpyrimidin-2-amines: synthesis, spectral analysis, and in vitro microbiological evaluation. AB - Compounds 4-(4-morpholinophenyl)-6-phenylpyrimidin-2-amine 20, 4-(4 methoxyphenyl)-6-(4-morpholinophenyl)pyrimidin-2-amine 23, 4-(4-bromophenyl)-6-(4 morpholinophenyl)pyrimidin-2-amine 25, 4-(3-chlorophenyl)-6-(4-morpholinophenyl) pyrimidin-2-amine 27, and 4-(3-fluorophenyl)-6-(4-morpholinophenyl)pyrimidin-2 amine 28 exerted excellent antibacterial activity against V. cholerae. Compounds 4-(4-chlorophenyl)-6-(4-morpholinophenyl)pyrimidin-2-amine 22, 25, 4-(4 morpholinophenyl)-6-(3-nitrophenyl)pyrimidin-2-amine 26, and 28, which contained electron-withdrawing chloro, bromo, nitro, and fluoro functional groups, respectively, at the para/meta position of the phenyl ring attached to the pyrimidine ring promoted much activity against S. aureus. Compounds 4-(4 fluorophenyl)-6-(4-morpholinophenyl)pyrimidin-2-amine 24 and 25 (against beta hemolytic Streptococcus) and compound 28 (against S. felxneri) showed pronounced activity. Compounds 26 and 28 (against K. pneumoniae) and compounds 24, 25, and 28 (against P. aeruginosa) exerted strong antibacterial activity. Compounds 22 and 25 promoted much antifungal activity against A. flavus, while compounds 24 and 25 registered maximum activity against Mucor. Compounds 23 (against C. albicans) and 27 and 28 (against Rhizopus) promoted good activity. PMID- 19874136 TI - Synthesis and biological evaluation of biguanide and dihydrotriazine derivatives as potential inhibitors of dihydrofolate reductase of opportunistic microorganisms. AB - Twenty-one biguanide and dihydrotriazine derivatives were synthesized and evaluated as inhibitors of dihydrofolate reductase (DHFR) from opportunistic microorganisms: Pneumocystis carinii (pc), Toxoplasma gondii (tg), Mycobacterium avium (ma), and rat liver (rl). The most potent compound in the series was B2-07 with 12 nM activity against tgDHFR. The most striking observation was that B2-07 showed similar potency to trimetrexate, approximately 233-fold improved potency over trimethoprim and approximately 7-fold increased selectivity as compared to trimetrexate against tgDHFR. Molecular docking studies in the developed homology model of tgDHFR rationalized the observed potency of B2-07. This molecule can act as a good lead for further design of molecules with better selectivity and improved potency. PMID- 19874137 TI - Inhibitory effects of thioethers on fatty acid synthase and 3T3-L1 cells. AB - Thioethers are the main flavor compounds found in Liliaceae Allium vegetables and have been shown to have beneficial effects against several diseases correlated with metabolic syndrome. The inhibitory effects of six thioethers on fatty acid synthase (FAS) were investigated. Dose-dependent and time-dependent inhibitions of FAS by one trisulfide and two disulfides were revealed. Diallyl trisulfide (DATS, IC(50) = 8.37 microM) was the most active of these thioethers. Inhibition kinetics, substrate protection analysis, and stoichiometric assay revealed that DATS interacted with both essential sulfhydryl groups on the acyl-carrier protein and beta-ketoacyl synthase domain of FAS to inactivate the enzyme. The inactivation by DATS represented affinity-labeling kinetics. The active thioethers also inhibited the differentiation and lipid accumulation of 3T3-L1 preadipocytes, and the effect was related to their inhibition of FAS. It is suggested that the inhibition on FAS by thioethers and Allium vegetables is an important factor for their effects against metabolic syndrome. PMID- 19874138 TI - Inhibition of purified bovine liver glutathione reductase with some metal ions. AB - Glutathione reductase (GR; E.C. 1.6.4.2) is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). In this study we tested the effects of Al3+, Ba2+, Ca2+, Li+, Mn2+, Mo6+, Cd2+, Ni2+, and Zn2+ on purified bovine liver GR. In a range of 10 microM-10 mM concentrations, Al3+, Ba2+, Li+, Mn2+, and Mo6+, and Ca2+ at 5 microM-1.25 mM, had no effect on bovine liver GR. Cadmium (Cd2+), nickel (Ni2+), and zinc (Zn2+) showed inhibitory effects on this enzyme. The obtained IC50 values of Cd2+, Ni2+, and Zn2+ were 0.08, 0.8, and 1 mM, respectively. Cd2+ inhibition was non-competitive with respect to both GSSG (Ki(GSSG) 0.221 +/- 0.02 mM) and NADPH (Ki(NADPH) 0.113 +/- 0.008 mM). Ni2+ inhibition was non-competitive with respect to GSSG (Ki(GSSG) 0.313 +/- 0.01 mM) and uncompetitive with respect to NADPH (Ki(NADPH) 0.932 +/- 0.03 mM). The effect of Zn2+ on GR activity was consistent with a non-competitive inhibition pattern when the varied substrates were GSSG (Ki(GSSG) 0.320 +/- 0.018 mM) and NADPH (Ki(NADPH) 0.761 +/- 0.04 mM), respectively. PMID- 19874139 TI - Global elimination of blinding trachoma by 2020: where are we? PMID- 19874140 TI - Rapid assessment of trachoma among children living in rural northern India. AB - PURPOSE: Rapid assessment of active trachoma in children aged 1-9 years in a previously hyperendemic rural area in Haryana, India. METHODS: Ten disadvantaged villages each with a population of 3000-5000 were chosen by cluster random sampling. One thousand children from 500 households in the most underdeveloped parts of the villages--identified by observation and consultation, between the ages of 1-9 years--were examined for signs of Trachomatous inflammation follicular (TF) and Trachomatous inflammation intense (TI). Assessment was done in a health care unit. Examination of both eyes for signs of trachoma and its complications was done with the aid of binocular loupe (2.5X magnification). Tarsal conjunctival swabs from patients of active trachoma were analyzed by direct immunofluorescence assay and polymerase chain reaction for Chlamydia trachomatis antigen. RESULTS: Forty children (males 21, females 19) had signs of active trachoma that included TF (33) and TI (7). At least one ocular morbidity was present in 69% of all children that were examined. Unclean face carried a 2.70 (confidence interval [CI] = 1.30-5.37) times higher risk and poor ocular hygiene had 2.05 (CI = 1.02-4.11) times higher risk for trachoma infection. Among clinically positive cases, direct immunofluorescence assay and polymerase chain reaction assays were positive in 25% and 10%, respectively. CONCLUSIONS: Active trachoma is not a public health problem in previously hyperendemic areas of North India. PMID- 19874141 TI - The pattern of childhood blindness in Karnataka, South India. AB - PURPOSE: To determine the causes of severe visual impairment and blindness in children in schools for the blind in southern Karnataka state of India. METHOD: Children aged less than 16 years with a visual acuity of < 6/60 in the better eye, attending the residential schools for the blind were examined in 2005-2006, in the Karnataka state in the south of India. History taking, visual acuity estimation, external ocular examination, retinoscopy, and fundoscopy were done on all students. Refraction and low vision work-up done where indicated. The anatomical and etiological causes of severe visual impairment (< 6/60-3/60) and blindness (< 3/60 in the better eye) were classified using the World Health Organization's prevention of blindness programs' record system. RESULTS: A total of 1,179 students were examined, 891 of whom fulfilled the eligibility criteria. The major anatomical sites of visual loss were congenital anomalies (microphthalmos, anophthalmos) (321, 35.7%), corneal conditions (mainly scarring due to vitamin A deficiency, measles, trauma) (133, 14.9%), cataract or aphakia in 102 (11.4%), and retinal disorders (mainly dystrophies) in 177 children (19.9%). Nearly one-fourth of children were blind from conditions which could have been prevented or treated (27.8%), 87 of whom were referred for surgery. Low vision devices improved near acuity in 27 children (3%), and 43 (4.8%) benefited from refraction. CONCLUSIONS: Congenital anomalies, cataract, and retinal conditions account for most of the blindness in children. PMID- 19874142 TI - Economics and attitudes regarding spectacles in daily life: a European perspective. AB - PURPOSE: The objectives of this survey were to collect data from five European countries (France, Germany, Italy, Spain, and the United Kingdom) on the societal costs of spectacle dependence and respondents' willingness to pay (WTP) for freedom from spectacles. METHODS: Samples of citizens age >or=45 years and currently wearing spectacles were selected according to a quota method (age, gender, occupation) and interviewed (22 questions) using a Computer-Assisted Telephone Interviewing system. RESULTS: In total, 4,157 respondents were interviewed across the 5 countries; 38.4% were age >or=65 years and 55.8% female. Most prescribed lenses were monofocal (49.7-72.8%) in all countries, except in France (29.8%). The most frequent replacement interval (70.4%) was >or=2 years and the average cost was > euro 145 per pair (62.9%). Replacements were most frequent in the UK and expenditure was highest in France. The three most common everyday tasks requiring spectacles were reading (60.4%), watching TV (33.6%) and shopping (28.8%). Willingness to pay varied across countries, the UK subjects expressing the lowest values; this was especially true for men and persons aged < 64 years. CONCLUSION: Respondents in France bought mostly expensive spectacles while Italians acquired the least expensive eyeglasses. The spectacle frequency of replacement rate is inversely related to prices. About half of all respondents expressed a WTP, at least partially, for freedom from spectacles. PMID- 19874143 TI - Stated and actual willingness to pay for spectacles in Timor-Leste. AB - PURPOSE: To conduct a survey of willingness to pay for ready-made spectacles in the low-resource country of Timor-Leste, and, uniquely, subsequent validation with actual payment information. METHODS: A systematic random sampling strategy was used to apply a binary with follow-up stated willingness to pay methodology. Findings were validated by comparing the amount declared willing to pay with the actual price paid at a subsequent visit. RESULTS: Of the 152 participants (96.2%; mean age 50.9 +/- 13.2 years; 50.0% female) agreeable to wearing spectacles if required, 84.9% were willing to pay for them, with 82.9% of these willing to pay at least United States dollars (USD) 0.10. By multivariate analysis, increasing age and owning fewer animals were significantly and independently associated with unwillingness to pay at least USD 0.10. Of the survey participants agreeable to wearing spectacles who attended a later visit (113/152; 74.3%; 53.1% female), the 80.5% who would benefit were offered spectacles, first for USD 1.00. If declined, this was revised to USD 0.10. If this was declined, the spectacles were dispensed, unknown to subsequent attendees, at no charge. The predictive value of stated willingness to pay at least USD 0.10 was 96.3%. CONCLUSIONS: Binary with follow-up stated willingness to pay with validation against actual payment was successfully applied to spectacles in Timor-Leste. PMID- 19874144 TI - Epidemiology of refractive errors in an adult European population: the Segovia study. AB - PURPOSE: To determine the prevalence of refractive errors in Segovia, Spain. METHODS: A cohort of 569 subjects was randomly selected in a stratified manner according to gender and age in a cross-sectional, population-based epidemiologic study, the target population of which was urban residents aged 40 to 79 years. All participants underwent an ophthalmic examination that included measurement of visual acuity (VA) and refraction, tonometry, anterior segment biomicroscopy, funduscopy, optic nerve head photography, and visual field testing. Of those, 417 subjects were enrolled who met the inclusion criteria of a phakic right eye and VA over 20/40. The prevalence of spherical errors was assessed after calculating the spherical equivalent and defining myopia as -0.5 diopters (D) or less and hyperopia as +0.50 D or more. The prevalence of astigmatism over 0.50 D was evaluated in minus cylinder form. RESULTS: The estimated prevalences (95% confidence interval) of myopia, hyperopia, and astigmatism, in the population were 25.4% (21.5-29.8%) 43.6% (39-48.4%), and 53.5% (48.7-58.2%), respectively. No significant gender difference was found in the prevalence of any refractive errors. The prevalence of myopia or the mean value did not change significantly with age. The mean hyperopia and the mean astigmatism (p < 0.01 for both) and the prevalence increased with increasing age (p < 0.01 for both). Anisometropia of 1 D or more was present in 12.3% (49/396 subjects). CONCLUSION: More than 60% of the Segovia population over 40 years of age has a refractive error, with 25.4% myopic and 43.6% hyperopic. Astigmatism is present in over half of the population and the types change with age. PMID- 19874145 TI - Assessment of the Student Sight Savers Program methods for glaucoma screening. AB - PURPOSE: To assess methods used for glaucoma screening in the Student Sight Savers Program (SSSP), an initiative of the Friends of the Congressional Glaucoma Caucus Foundation that has screened individuals for glaucoma in the United States since 2001. METHODS: This was a prospective, case-control, clinic-based study (total N = 70). Patients with primary open-angle glaucoma and age- and sex matched controls with no evidence of glaucoma or other ocular disease were evaluated with the SSSP screening method. Primary outcome measures were sensitivity, specificity, and positive predictive power for both low- and high prevalence populations. RESULTS: Sensitivity and specificity values of the individual tests were 48.6% and 68.6% for family history of glaucoma, 22.1% and 78.6% for intraocular pressure (IOP), and 58.1% and 98.6% for frequency doubling technology (FDT) visual field (P = 0.03, chi-square). Specificity of FDT was significantly better than IOP (P < 0.001) and the questionnaire (P < 0.01) by z test. When analyzing the overall screening criteria (positive screen was >or= 1 positive in the three tests), the sensitivity increased to 88.6% with reduction in specificity to 57.1%. The positive predictive power (PPP) for high-prevalence population was low for the overall screening criteria (15.4%) and highest for FDT as an individual (34.0%) or combined (41.0% to 45.3%) test. The medical student education and community awareness aspects of the program were not assessed. CONCLUSIONS: Of different methods used in the SSSP, FDT was the best single screening test, demonstrating high specificity but only moderate sensitivity. Use of multiple screening criteria resulted in slightly increased sensitivity and PPP over FDT, but decreased specificity. PMID- 19874146 TI - Effect of light perception on menarche in blind women. AB - PURPOSE: The role of light on human reproductive development is unclear. Women with varying degrees of visual impairment appear to have altered reproductive function compared to sighted women. These differences have been attributed in part to differences in light exposure between the sighted and the blind. The present study was conducted to determine whether differences exist in reproductive measures among blind women with at least light perception (LP) compared to women with no perception of light (NPL). METHODS: We studied 1,392 (LP, n = 968; NPL, n = 417; unreported, n = 7) blind women across North America between 2005 and 2007. Statistical analysis was conducted using Student's two sample t tests and multivariate logistic or linear regression. Models were adjusted for current age, body mass index (BMI) and BMI at age 18. RESULTS: NPL women reported an earlier menarche (mean age, 12.16, standard deviation +/- 1.53) than LP women (mean age, 12.46, +/- 1.57 yrs). The adjusted odds ratio (OR) for each increasing year of menarche among NPL women compared to LP women, was 0.88 (95% confidence intervals [CI]: 0.81-0.96). When those women NPL from birth were compared to all others, the adjusted odds ratio was strengthened (OR: 0.80, 95% CI: 0.68-0.94). When we examined the association between age at onset of NPL and age at menarche, we found a significant positive association with earlier menarche being associated with an earlier age category of loss of light perception (test for trend p < 0.01). CONCLUSIONS: Our findings suggest that lack of light perception affects reproductive development in women. PMID- 19874147 TI - Survey effect on use of eye care by older persons with correctable visual impairment. AB - PURPOSE: To assess changes in the pattern of eye care utilization among older Australians with correctable visual impairment, identified in an eye survey. METHODS: The Blue Mountains Eye Study (BMES) examined 3654 Australians aged >or= 49 years at baseline (BMES-I). Five-year follow-up examinations were attended by 2334 participants, 75.0% of survivors (BMES-II). Interviewers collected data on eye care utilization at each visit. Habitual (presenting) and best-corrected visual acuity were assessed using a LogMAR chart. Survey reports, including visual acuity and recommendations were sent to participants after each visit. Those with under-corrected refractive error were informed that they could benefit from a new distance prescription. Eye care utilization was compared before and after the BMES-I survey. RESULTS: Of 2152 participants with data from both examinations, 26 had non-correctable and 115 had correctable visual impairment at BMES-I. The proportion of the 115 participants with correctable visual impairment who reported seeing an eye care provider during the previous 2 years increased from 55% at BMES-I to 64% at BMES-II. Comparing the data collected at BMES-II with that at BMES-I, a higher proportion of reported optometric visits in the previous 5 years was evident for all participants regardless of their correctable visual impairment status. Among those with correctable visual impairment at BMES I, 58% improved to no visual impairment at BMES-II, and the proportion who subsequently wore distance correction increased from 57% to 71%. CONCLUSIONS: We observed modest increases in eye care utilization by older persons after an eye survey, particularly those with correctable visual impairment. PMID- 19874148 TI - Non-mydriatic digital macular photography: how good is the second eye photograph? AB - PURPOSE: In an elderly Australian population, to evaluate the quality of fundus photographs taken non-mydriatically in both eyes, and to compare the quality of those taken second with those taken first. METHODS: From 2258 participants (4516 images) aged 70 years and older who participated in the Melbourne Collaborative Cohort Study (MCCS), digital non-stereoscopic 45 degrees retinal photographs were taken with a Canon CR6-45NM Non-mydriatic Retinal Camera and evaluated. The quality of macular images was assessed as good, fair, and poor and McNemar's test was used to analyze variation in quality. RESULTS: Gradable quality images were obtained from 95.8% eyes of participants, with 93.9% of participants having gradable photos of both eyes. The gradable rate for the eye photographed first (right), was significantly higher than that for the eye photographed second (left): 89.7% vs. 85.6%, respectively (difference of 4.12%, confidence interval [CI] of 2.68-5.54%, p < 0.001). The rate of ungradable photographs from the second eye was slightly greater than the first eye (4.5% and 3.8%, respectively), but the difference in proportion was not statistically significant (difference of 3.6%, CI of 0.17-1.5%, p = 0.384). CONCLUSIONS: In the setting of a large elderly cohort study, non-dilated 45 degrees digital retinal imaging is an excellent method for fundus examination. It is fast, easy to use, non-invasive, and a reliable AMD (age-related macular degeneration)-detecting technique with only a minor loss of information from the second eye. PMID- 19874149 TI - Visual function versus visual acuity in older people. AB - PURPOSE: To determine visual function (VF) status in older people, to establish its degree of correlation with visual acuity (VA), and to assess its association with other physical and mental functional limitations. PARTICIPANTS: A sample of 1,160 persons aged 65 years or over were selected by simple randomization. METHODS: The participants' VF (The Visual Function Index - VF-14), VA, self reported vision, mental and physical function (Katz Index, Pfeiffer's test, and Geriatric Depression Scale), and socio-demographic data were determined. Multiple linear regression was used to assess the association between VF and its conditioning factors. Statistical adjustment was made for the possible confounding variables. RESULTS: Of the studied subjects, 6.3% (95% confidence interval (CI) = 4.93-7.82) had VA of less than 6/18 in the better eye and 20.9% (95% CI = 18.6-23.3) had VA of less than 6/12. The best corrected VA of each participant demonstrated moderate correlation with his or her VF-14 score (r = 0.416; p < 0.001). Using multiple regression analysis, the variables associated with VF status were: visual impairment, self-reported poor vision, dependence in daily activities, cognitive impairment, depressive symptoms, female gender and older age. These independent variables explain 34.4% (r(2) = 0.344) of the variation in the data. CONCLUSIONS: VF impairment is common in older persons and when associated with other limitations, it may be considered a major health problem with important consequences. As a complement to the preventive care guidelines on VA in older persons, assessment of VF impairment in clinical practice, using appropriate visual screening tools, is advisable. PMID- 19874150 TI - Actin filament nucleation and elongation factors--structure-function relationships. AB - The spontaneous and unregulated polymerization of actin filaments is inhibited in cells by actin monomer-binding proteins such as profilin and Tbeta4. Eukaryotic cells and certain pathogens use filament nucleators to stabilize actin polymerization nuclei, whose formation is rate-limiting. Known filament nucleators include the Arp2/3 complex and its large family of nucleation promoting factors (NPFs), formins, Spire, Cobl, VopL/VopF, TARP and Lmod. These molecules control the time and location for polymerization, and additionally influence the structures of the actin networks that they generate. Filament nucleators are generally unrelated, but with the exception of formins they all use the WASP-Homology 2 domain (WH2 or W), a small and versatile actin-binding motif, for interaction with actin. A common architecture, found in Spire, Cobl and VopL/VopF, consists of tandem W domains that bind three to four actin subunits to form a nucleus. Structural considerations suggest that NPFs-Arp2/3 complex can also be viewed as a specialized form of tandem W-based nucleator. Formins are unique in that they use the formin-homology 2 (FH2) domain for interaction with actin and promote not only nucleation, but also processive barbed end elongation. In contrast, the elongation function among W-based nucleators has been "outsourced" to a dedicated family of proteins, Eva/VASP, which are related to WASP-family NPFs. PMID- 19874151 TI - Transient cocaine-associated behavioral symptoms rated with a new instrument, the scale for assessment of positive symptoms for cocaine-induced psychosis (SAPS CIP). AB - Chronic use of cocaine is associated with a variety of behavioral symptoms. The current report describes the assessment of cocaine-related behavioral symptoms (CRB) using the Scale for Assessment of Positive Symptoms of Cocaine-Induced Psychosis (SAPS-CIP). The CRB section, one of the three domains in the SAPS-CIP, consists of sub-domains, including Aggressive/Agitated Behavior, Repetitive/Stereotyped Behavior, and Unusual Social or Sexual Behavior. Severity scores are assigned according to operational criteria, and range from 0 (not present) to 5 (severe). We interviewed 261 unrelated cocaine-abusing adults using the SAPS-CIP, and 243 of them met criteria for inclusion in the study. The proportion of subjects endorsing different classes of CRBs varied across categories, with 109 of 243 (44.9%) subjects reporting aggressive and agitated behaviors, 180 subjects (74.1%) repetitive/stereotyped behaviors, and 192 (79.0%) unusual social/sexual behaviors. A substantial minority of the subjects (10.3 25.1%) reported that they experienced marked-to-severe behavioral symptoms associated with cocaine use. The proportions of subjects endorsing CRB did not differ by ethnic/racial group or by sex. Correlations among the different domains of CRB were strong, but behaviors rated in the CRB section were less well correlated with psychotic symptoms, which were rated in the hallucination and delusion sections of the instrument. A variety of CRBs are common in cocaine dependent subjects, and many of these are highly intercorrelated. CRBs also correlate with hallucinations and delusions induced by cocaine, but to a lesser degree. Our findings suggest that there may be some common vulnerability factors that contribute to both cocaine-induced psychosis and CRBs. PMID- 19874152 TI - Uses of diverted methadone and buprenorphine by opioid-addicted individuals in Baltimore, Maryland. AB - This study examined the uses of diverted methadone and buprenorphine among opiate addicted individuals recruited from new admissions to methadone programs and from out-of-treatment individuals recruited from the streets. Self-report data regarding diversion were obtained from surveys and semi-structured qualitative interviews. Approximately 16% (n = 84) of the total sample (N = 515) reported using diverted (street) methadone two-three times per week for six months or more, and for an average of 7.8 days (SD = 10.3) within the past month. The group reporting lifetime use of diverted methadone as compared to the group that did not report such use was less likely to use heroin and cocaine in the 30 days prior to admission (ps <.01) and had lower ASI Drug Composite scores (p <.05). Participants in our qualitative sub-sample (n = 22) indicated that street methadone was more widely used than street buprenorphine and that both drugs were largely used as self-medication for detoxification and withdrawal symptoms. Participants reported using low dosages and no injection of either medication was reported. PMID- 19874154 TI - Coerced childhood sexual abuse moderates the association between cigarette smoking initiation and college drug use frequency. AB - The current study examined childhood sexual abuse (CSA) as a potential moderator of the "gateway theory" association of cigarette use onset and college drug use. Covariate adjusted hierarchical regressions showed that CSA history interacted with age of first cigarette to predict total 12-month illicit drug use frequency (Delta R(2) =.048, F(10, 76) = 4.041, Mse = 8.812, p =.021). Simple effects revealed that age of first cigarette predicted drug use frequency in individuals with CSA histories (p =.045) rather than non-CSA individuals (p =.103). Exploratory analyses further revealed that the CSA moderation was carried primarily by those exposed to forced/coerced CSA events. Implications of the findings are discussed. PMID- 19874153 TI - High-dose naltrexone therapy for cocaine-alcohol dependence. AB - This randomized, double-blind, placebo-controlled study compared the effects of high-dose (100 mg/d) naltrexone versus placebo in a sample of 87 randomized subjects with both cocaine and alcohol dependence. Medication conditions were crossed with two behavioral therapy platforms that examined whether adding contingency management (CM) that targeted cocaine abstinence would enhance naltrexone effects compared to cognitive behavioral therapy (CBT) without CM. Primary outcome measures for cocaine (urine screens) and alcohol use (timeline followback) were collected thrice-weekly during 12 weeks of treatment. Retention in treatment and medication compliance rates were low. Rates of cocaine use and drinks per day did not differ between treatment groups; however naltrexone did reduce frequency of heavy drinking days, as did CBT without CM. Notably, adding CM to CBT did not enhance treatment outcomes. These weak findings suggest that pharmacological and behavioral interventions that have shown efficacy in the treatment of a single drug dependence disorder may not provide the coverage needed when targeting dual drug dependence. PMID- 19874155 TI - Youth tobacco access and possession policy interventions: effects on observed and perceived tobacco use. AB - This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty-four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use. PMID- 19874156 TI - Addictive severity in cocaine addicts measured with the EuropASI: differences between composite scores and severity ratings. AB - In this study we present the addiction severity profile in a sample of 202 cocaine addicts, using the composite scores for each area of the EuropASI (European version of the ASI), which are compared with the severity ratings obtained through interviewers' subjective assessments. The results showed that the areas of the EuropASI which reflected the greatest severity according to the composite scores were, in the following order: employment/support, family/social situation, use of alcohol and psychiatric state. The results obtained with the composite scores show discrepancies with those obtained from the severity rating. Statistically significant differences were found in the areas of alcohol (Z = 6.205; p < 0.001), drugs (Z = -11.902; p < 0.001), family/social (Z = -6.915; p < 0.001) and psychiatric status (Z = -6.651; p < 0.001). The results call into question the reliability and validity of severity ratings obtained through interviewers' subjective assessments. For diagnosis and research, a more objective appraisal is recommended, using composite scores, since severity ratings depend totally on the interviewer's judgement, and do not appear to constitute a sound measure for estimating therapeutic change. PMID- 19874157 TI - Allopathic, complementary, and alternative medical treatment utilization for pain among methadone-maintained patients. AB - We surveyed 150 methadone maintenance treatment program (MMTP) patients about pain, pain treatment utilization, perceived efficacy of prior pain treatment, and interest in pursuing pain treatment at the MMTP. Respondents with chronic severe pain (CSP) (ie, pain lasting at least six months with moderate to severe pain intensity or significant pain interference) and "some pain" (ie, pain reported in the previous week but not CSP) endorsed similar rates of past-week and lifetime allopathic or standard medical (with the exception of lifetime medical use of non opiate medication) and complementary and alternative medicine (CAM) utilization for pain reduction. Prior pain treatments were perceived to be less effective by CSP than SP patients but both groups had equivalent high rates of interest in pain treatment associated with the MMTP. These findings may have implications for resource and program planning in MMTPs. PMID- 19874159 TI - Retrospective safety analysis of atomoxetine in adult ADHD patients with or without comorbid alcohol abuse and dependence. AB - This post hoc analysis compared the safety of atomoxetine treatment of ADHD in adults with or without comorbid alcohol abuse/dependence. Study completion rates in patients receiving atomoxetine were comparable between heavy drinkers (60.9%) and patients with no alcohol-use disorder (71.0%) but lower in nonheavy drinkers (35.7%); however, there was no significant difference in discontinuation rates due to adverse events or lack of efficacy among these groups. Alcohol-use disorder patients, especially heavy drinkers, generally experienced the greatest frequency of treatment-emergent adverse events in both the atomoxetine and placebo groups. Vital signs and measures of hepatic function were not significantly different among the 3 drinking status groups taking atomoxetine. PMID- 19874158 TI - Is implementation of the 5 A's of smoking cessation at community mental health centers effective for reduction of smoking by patients with serious mental illness? AB - We tested whether implementing the "5 A's" (Ask, Advise, Assess, Assist, Arrange) at six mental health centers reduces smoking among persons with serious mental illness. One hundred and fifty six patients were evaluated just before initiating the 5 A's and after six and 12 months. A delayed control condition evaluated 148 patients six months before 5 A's implementation, just before and then after six months. Six months of the 5 A's produced no effect. Modest cessation and reduction benefits were noted after 12 months. Implementing the 5 A's at community mental health centers may have modest benefit after twelve months. PMID- 19874160 TI - Social support is associated with gambling treatment outcomes in pathological gamblers. AB - Poor social support is a contributory factor in development of addictive disorders, but it has rarely been evaluated in pathological gamblers. This study examined social support in pathological gamblers and its relationship with treatment outcomes. Low baseline social support was associated with increased severity of gambling, family, and psychiatric problems and poorer post-treatment outcomes. Further, social support assessed post-treatment was significantly related to severity of gambling problems at the 12-month follow-up. These findings demonstrate that social support plays an important role in moderating outcomes, and enhancing social support may be an important aspect of effective gambling treatments. PMID- 19874161 TI - An evaluation of the nature of marijuana use and its motives among young adult active users. AB - The present investigation examined marijuana use, abuse, and dependence in relation to self-reported marijuana use behaviors and motives, as well as concurrent cigarette and problematic alcohol use among a sample of young adult current marijuana users (n = 200; 44.5% women; M(age) = 21.48, SD = 6.54). Preliminary results broadly indicated that more severe forms of marijuana use (eg, dependence) were associated with a more problematic pattern of marijuana use behavior, polysubstance use, and greater motivation to use marijuana for multiple reasons. Results are discussed in relation to better understanding the underlying nature of marijuana use and its disorders among young adults. PMID- 19874162 TI - Disproportionately high rate of epileptic seizure in patients abusing dextropropoxyphene. AB - Dextropropoxyphene (DPP), a weak opioid, is often abused as a psychoactive substance. In this retrospective chart review to document, characterize and put in perspective the often-obtained history of epileptic seizures in patients with DPP abuse, we analyzed the case files of all patients with DPP abuse registered in our center (a tertiary-care drug de-addiction clinic in north India) from May 1, 2001 until April 30, 2007 and those with use of other opioids during the same period. Non-drug-related seizures were excluded from analysis. Out of 312 patients with DPP abuse, 63 (20.2%) had epileptic seizures related to DPP use, in contrast to 0.4% -4.2% of other opioid users. The seizures were mostly characterized as generalized tonic-clonic seizures (87.3%), occurring around two hours following a higher-than-usual dose of DPP. Those with seizures had significantly greater duration of DPP use and higher rates of medical comorbidity compared to patients without seizure. Age, duration of use and medical comorbidity were better predictors of seizure than dosage of drug or use of multiple drugs. Thus, DPP-induced epileptic seizures are common (one in five), and much more frequent than seizures in patients using other opioids. The awareness of this phenomenon has implications for diagnosis and management, as well as for drug regulation policy. PMID- 19874163 TI - Relationship between cigarette use and mood/anxiety disorders among pregnant methadone-maintained patients. AB - This study investigates the association between cigarette use and current mood/anxiety disorders among pregnant opioid-dependent patients. Pregnant methadone-maintained women (N = 122) completed the Addiction Severity Index and Structured Clinical Interview for DSM-IV. Participants were categorized based on past 30 days cigarette use: no (n = 15) and any smoking (n = 107); this latter group was then subdivided into light (one to ten cigarettes/day; n = 55), and heavy smokers (11+ cigarettes/day; n = 52). Any smoking was significantly associated with any current mood/anxiety disorder (p < 0.001), any current mood disorder (p = 0.007), and any current anxiety disorder (p < 0.001). No significant association was found between specific level of cigarette use and mood/anxiety disorders. This association between smoking and psychiatric disorders has implications for the mental and physical health of methadone maintained women and their children, and may contribute to the understanding of the physiological mechanisms underlying smoking and nicotine dependence. PMID- 19874164 TI - Sleep impairment in ecstasy/polydrug and cannabis-only users. AB - The present study investigated aspects of sleep quality in ecstasy and cannabis users. Two-hundred and twenty seven participants (117 ecstasy/polydrug users, 53 cannabis users and 57 drug naive participants) took part. The participants completed measures of daytime sleepiness, and indicators of sleep quality. The results demonstrated that ecstasy/polydrug users viewed themselves as being more evening types and having poorer sleep quality than cannabis users and drug naive participants. They were also more likely to have missed a night's sleep. The reported differences in sleep type may reflect ecstasy-related serotonergic dysfunction resulting in problems with shifting circadian rhythms. PMID- 19874167 TI - Characteristics of pathological gamblers with a problem gambling parent. AB - This analysis compares the characteristics of adult pathological gamblers with and without a problem gambling parent. A sample of 517 individuals with current DSM-IV pathological gambling was categorized based on presence of a parental problem gambler. Groups were compared on clinical characteristics, gambling severity, gambling-related problems, and psychiatric comorbidity. Although the groups were similar on most measures, pathological gamblers with at least one problem gambling parent were more likely to have a father with an alcohol abuse/dependence problem; have financial and legal problems; and report daily nicotine use. Females with a problem gambling parent had significantly earlier onset of gambling behavior, were significantly more likely to have a father with an alcohol use disorder, and were significantly more likely to have financial problems secondary to gambling than females without a problem gambling parent. Males with a problem gambling parent were significantly more likely to have a father with an alcohol use disorder and have legal problems secondary to gambling compared to males without a problem gambling parent. Treatment approaches may need to be tailored for specific problems secondary to gambling and gender issues based on the history of having a problem gambling parent. PMID- 19874166 TI - The variety of ecstasy/MDMA users: results from the National Epidemiologic Survey on alcohol and related conditions. AB - This study investigates the potential heterogeneity of ecstasy or MDMA (3,4 methylenedioxy-N-methylamphetamine) users. Data came from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Latent class analysis (LCA) and multinomial logistic regression procedures were used to identify subtypes of ecstasy users. Approximately 1.6% (n = 562) of adult participants (N = 43,093) reported lifetime ecstasy use. LCA identified three subtypes of ecstasy users. Class 1 exhibited pervasive use of most drug classes (ecstasy-polydrug users, 37%). Class 2 reported a high rate of use of marijuana and cocaine and a moderate use of amphetamines (ecstasy-marijuana-stimulant users, 29%). Class 3 was characterized by a high rate of use of marijuana and a low use of primarily prescription-type drugs (ecstasy-marijuana users, 34%). Subtypes were distinguished by family income, history of substance abuse treatment, and familial substance abuse. Class 1 exhibited the highest prevalence of disorders related to the use of marijuana (77%), tobacco (66%), amphetamines (36%), opioids (35%), sedatives (31%), and tranquilizers (30%). The recent resurgence in ecstasy use among adults underscores the need to monitor trends in its use. PMID- 19874168 TI - Psychiatric comorbidity reduces quality of life in chronic methadone maintained patients. AB - Despite the efficacy of methadone maintenance treatment (MMT), opioid dependence still involves severe impairment of functioning and low quality of life. This study examines the influence of the psychiatric comorbidity of MMT patients on their quality of life. A total of 193 middle-aged patients in long-term MMT were assessed for current and lifetime Axis I psychiatric disorders, substance use disorders, and personality disorders using the MINI, the CIDI-SAM, and the SIDP IV. Quality of life (Qol) was assessed using the EQ-5D. Psychiatric comorbidity was documented in 78% of the patients. Mood disorders (60%) and anxiety disorders (46%) were the most common diagnoses. Additional substance use disorders were diagnosed in 70% of the MMT patients. While a probable personality disorder was documented for 65% of the patients, 66 of these patients actually showed an antisocial personality disorder. Qol was severely diminished to a level comparable to that for patients with chronic psychiatric and/or somatic disorders. Multivariate analyses showed the occurrence of comorbid psychiatric disorders to explain about 32% of the variance in Qol. The quality of life for MMT patients is generally low. The present results showed a high rate of psychiatric comorbidity for this patient group with mood disorders, additional substance use disorders, and personality disorders occurring in particular. Such comorbid psychopathology substantially affects quality of life. The negative influence of comorbid psychopathology on quality of life is an important reason to provide additional mental health services for MMT patients. PMID- 19874165 TI - Obesity and its relationship to addictions: is overeating a form of addictive behavior? AB - Obesity is a major public health problem and notoriously difficult to treat. There are many parallels between obesity/overeating and addictions to alcohol and drugs. This paper discusses similarities between obesity and addictive disorders, including common personality characteristics, disruptive behavior syndromes, and brain mechanisms. Although there are important differences between overeating and other addictive behaviors, an addiction model of overeating may effectively inform prevention and treatment of obesity. PMID- 19874170 TI - A simple risk scoring system for prediction of relapse after inpatient alcohol treatment. AB - Predicting relapse after alcoholism treatment can be useful in targeting patients for aftercare services. However, a valid and practical instrument for predicting relapse risk does not exist. Based on a prospective study of alcoholism treatment, we developed the Risk of Alcoholic Relapse Scale (RARS) using items taken from the Addiction Severity Index and some basic demographic information. The RARS was cross-validated using two non-overlapping samples, and tested for its ability to predict relapse across different models of treatment. The RARS predicted relapse to drinking within 6 months after alcoholism treatment in both the original and the validation sample, and in a second validation sample it predicted admission to new treatment 3 years after treatment. The RARS can identify patients at high risk of relapse who need extra aftercare and support after treatment. PMID- 19874169 TI - Influence of verbal recall of a recent stress experience on anxiety and desire for cocaine in non-treatment seeking, cocaine-addicted volunteers. AB - It has long been postulated that stress increases the risk of drug abuse and relapse. The principal goal of this project was to evaluate the effects of verbal recall of a recent stress experience (specifically meaningful to each individual) on physiological and subjective measures in cocaine-addicted participants. Subjects described a recent stressful non-drug-related experience and a neutral non-stressful experience, and then completed mood and drug effect questionnaires, while heart rate and blood pressure were recorded. Participants (N = 25) were predominantly African American and male. As a group, participants used cocaine for more than 15 years and approximately 18 of the last 30 days, and a majority reported use of nicotine and/or alcohol. All participants were evaluated during a time in which they tested positive for cocaine metabolite. On a scale of 1-10, participants reported their verbal recall of a recent stress event as highly stressful and their verbal recall of a recent neutral event as non-stressful (p < 0.0001). The self-reported vividness of this recall was high (>8 out of 10) for both the stress and neutral events. Heart rate and systolic and diastolic blood pressure did not differ after verbal recall of either stress or neutral events. Similarly, self-reported subjective effects (including ratings of anxiety and craving for cocaine) did not differ after verbal recall of either stress or neutral events. In summary, despite the fact that participants recounted highly stressful and vivid memories, this experience did not elicit significant changes in cardiovascular or subjective effects. These data suggest that simply recalling a stressful event may not be a sufficient enough stimulus to contribute to craving or relapse in cocaine-addicted individuals. PMID- 19874176 TI - Reassortment between amantadine-resistant and -sensitive H1N1 influenza A viruses generated an amantadine-sensitive virus during the 2007-2008 season. AB - The frequency of the amantadine-resistant H1N1 influenza A virus has been increasing since the 2005-2006 season. It is unclear whether reassortment was involved in this trend. Here, we show that cocirculation of amantadine-resistant and -sensitive strains led to the genesis of amantadine-sensitive reassortant virus during the 2007-2008 season. Thereafter, the reassortant virus predominated. This contrasts with the trend for the H3N2 virus, in which the amantadine-resistant reassortant virus became predominant. The results suggest that it is necessary to monitor genome dynamics to understand the evolution and mechanism of the emergence and spread of antiviral resistance among influenza A viruses. PMID- 19874171 TI - Effects of a diagnosis or family history of alcoholism on the taste intensity and hedonic value of sucrose. AB - Given inconsistent findings in published studies, we examined whether a personal lifetime history of alcohol dependence (AD) or a parental history of alcoholism affected preference for sweet solutions. Ninety-three alcohol-dependent subjects rated the intensity and hedonic value of five different sucrose solutions, which was compared with similar data from 122 subjects screened to exclude alcohol dependence. The effect of a family history of alcoholism (FH) was examined in the AD group. Neither the diagnosis of AD nor a family history of alcoholism was associated with ratings of sweetness intensity or sweet preference. These findings do not support the hypothesis that sucrose preference is positively associated with either a personal lifetime history of AD or a family history of alcoholism. PMID- 19874177 TI - Immunopathogenesis and diagnosis of tuberculosis and tuberculosis-associated immune reconstitution inflammatory syndrome during early antiretroviral therapy. AB - BACKGROUND: In many settings, the benefits of antiretroviral therapy (ART) are reduced by the high early incidence of tuberculosis and tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS). METHODS: We used tuberculin skin testing and the QuantiFERON-TB Gold In-Tube assay to investigate cellular immune responses to purified protein derivative (PPD) and region of difference 1 (RD1) antigens during the first 24 weeks of ART. RESULTS: TB-IRIS and ART-associated tuberculosis occurred in 15 of 75 (20%) and 11 of 231 (4.8%) participants at risk, respectively. Greater increases in interferon gamma (IFN gamma) and skin test responses to PPD were seen at week 24 and 12 in participants with TB-IRIS (P< or = .04), respectively. Raw IFN-gamma responses to RD1 antigens and PPD corrected for pre-ART CD4(+) T cell counts were higher at all time points in individuals with ART-associated tuberculosis (P<.001) and were associated with areas under receiver operator characteristic curves of 0.90 for RD1 (95% confidence interval [CI], 0.78-1.00) and 0.92 for PPD (95% CI, 0.83-1.00) for the diagnosis of ART-associated tuberculosis. Pre-ART IFN-gamma responses enabled stratification of participants into groups with risks of subsequent tuberculosis of 0.7%, 9.3%, and 30.0%. CONCLUSIONS: Type 1 effector T cell responses are prominent in ART-associated tuberculosis, but additional immune defects may be more important in paradoxical TB-IRIS. IFN-gamma release assays may contribute to the prediction and diagnosis of tuberculosis during early ART. PMID- 19874178 TI - Low bone mineral density, renal dysfunction, and fracture risk in HIV infection: a cross-sectional study. AB - BACKGROUND: Reduced bone mineral density (BMD) is common in adults infected with human immunodeficiency virus (HIV). The role of proximal renal tubular dysfunction (PRTD) and alterations in bone metabolism in HIV-related low BMD are incompletely understood. METHODS: We quantified BMD (dual-energy x-ray absorptiometry), blood and urinary markers of bone metabolism and renal function, and risk factors for low BMD (hip or spine T score, -1 or less) in an ambulatory care setting. We determined factors associated with low BMD and calculated 10 year fracture risks using the World Health Organization FRAX equation. RESULTS: We studied 153 adults (98% men; median age, 48 years; median body mass index, 24.5; 67 [44%] were receiving tenofovir, 81 [53%] were receiving a boosted protease inhibitor [PI]). Sixty-five participants (42%) had low BMD, and 11 (7%) had PRTD. PI therapy was associated with low BMD in multivariable analysis (odds ratio, 2.69; 95% confidence interval, 1.09-6.63). Tenofovir use was associated with increased osteoblast and osteoclast activity (P< or = .002). The mean estimated 10-year risks were 1.2% for hip fracture and 5.4% for any major osteoporotic fracture. CONCLUSIONS: In this mostly male population, low BMD was significantly associated with PI therapy. Tenofovir recipients showed evidence of increased bone turnover. Measurement of BMD and estimation of fracture risk may be warranted in treated HIV-infected adults. PMID- 19874179 TI - Response to vicriviroc in treatment-experienced subjects, as determined by an enhanced-sensitivity coreceptor tropism assay: reanalysis of AIDS clinical trials group A5211. AB - The enhanced-sensitivity Trofile assay (Monogram Biosciences) was used to retest coreceptor use at both study screening and study entry for 118 treatment experienced subjects in AIDS Clinical Trials Group A5211 who had CCR5-tropic (R5) virus detected by the original Trofile assay at study screening. Among 90 recipients of vicriviroc, a significantly (P< .001) greater mean reduction in HIV 1 RNA was observed in 72 subjects with R5 virus versus 15 subjects reclassified as having dual/mixed-tropic viruses at screening: -1.11 versus -0.09 log(10) copies/mL at day 14 and -1.91 versus -0.57 log(10) copies/mL at week 24, respectively. Results suggest that the enhanced-sensitivity assay is a better screening tool for determining patient eligibility for CCR5 antagonist therapy. PMID- 19874181 TI - The effect of titanium particles on rat bone marrow stem cells in vitro. AB - In arthroplasty prostheses and dental implant, titanium is an excellent biocompatible material for its advanced physical qualities and better biocompatibility. However, it was reported that high ratios of titanium particles can be liberated due to the continual loading or articulation cycles of the implant. Because bone marrow stem cells (BMSCs) located adjacent to the implant are critical contributors to osseous tissue integrity, this study researched the influence of titanium particles on BMSCs' viability, proliferation, and cell skeleton. In addition, the phagocytosis of titanium particles by BMSCs and expression of tumor suppressor protein p53 were also examined. It was found that exposure of BMSCs to titanium particles disrupted their viability and proliferation in vitro, which may due to the phagocytosis of titanium particles by BMSCs. Moreover, cell skeleton was destroyed and the p53 protein level increased as the titanium particles were added. For these results, it was concluded that titanium particles had a cytotoxic effect on BMSCs in vitro and would inhibit the bone formation around the implant. PMID- 19874182 TI - Characteristics of aldehyde dehydrogenase 2 (Aldh2) knockout mice. AB - Acetaldehyde is an intermediate of ethanol oxidation. It covalently binds to DNA, and is known as a carcinogen. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme that oxidizes acetaldehyde. Approximately 45% of Chinese and Japanese individuals have the inactive ALDH2 genotypes (ALDH2*2/*2 and ALDH2*1/*2), and Aldh2 knockout mice appear to be a valid animal model for humans with inactive ALDH2. This review gives an overview of published studies on Aldh2 knockout mice, which were treated with ethanol or acetaldehyde. According to these studies, it was found that Aldh2 -/- mice (Aldh2 knockout mice) are more susceptible to ethanol and acetaldehyde-induced toxicity than Aldh2 +/+ mice (wild type mice). When mice were fed with ethanol, the mortality was increased. When they were exposed to atmospheres containing acetaldehyde, the Aldh2 -/- mice showed more severe toxic symptoms, like weight loss and higher blood acetaldehyde levels, as compared with the Aldh2 +/+ mice. Thus, ethanol and acetaldehyde treatment affects Aldh2 knockout mice more than wild type mice. Based on these findings, it is suggested that ethanol consumption and acetaldehyde inhalation are inferred to pose a higher risk to ALDH2-inactive humans. These results also support that ALDH2-deficient humans who habitually consume alcohol have a higher rate of cancer than humans with functional ALDH2. PMID- 19874184 TI - Entomological factors affecting the low endemicity of Chagas disease in Nazca, Southwestern Peru. AB - Chagas disease is prevalent in Peru. The province of Nazca, in the southwestern region of the country, shows a high intradomiciliary infestation rate of Triatoma infestans bugs. Although the vector is present, the number of Chagas disease cases appears to be much lower than those reported in the neighboring region of Arequipa. We examined 624 T. infestans from Nazca to determine the current Trypanosoma cruzi infection rates, and found that no bugs were infected with this parasite. These results contrast with those found in Arequipa, where 19-30% triatomines have been reported infected. To compare their vectorial capacity, we infected 30 T. infestans specimens, selected both from Nazca and Arequipa, by feeding bugs on T. cruzi-infected mice. The parasites developed all stages expected in the vector; furthermore, the infective stage, metacyclic trypomastigote, was found in both insect populations from the second week after infection. In addition, those insects that accepted to be fed with mice blood defecated immediately after finishing blood meal, indicating that they might be efficient vectors. We maintain that differences observed in infection rates between vectors from Nazca and Arequipa may be explained by differences in host availability. In Arequipa hosts are mainly small animals, whereas in Nazca the main blood source comes from birds, which are refractory to the infection. PMID- 19874183 TI - Distribution of antibodies reactive to Borrelia lonestari and Borrelia burgdorferi in white-tailed deer (Odocoileus virginianus) populations in the eastern United States. AB - Southern tick-associated rash illness is a Lyme-like syndrome that occurs in the southern states. Borrelia lonestari, which has been suggested as a possible causative agent of southern tick-associated rash illness, naturally infects white tailed deer (WTD; Odocoileus virginianus) and is transmitted by the lone star tick (Amblyomma americanum). To better understand the prevalence and distribution of Borrelia exposure among WTD, we tested WTD from 21 eastern states for antibodies reactive to B. lonestari using an indirect immunofluorescent antibody assay and Borrelia burgdorferi using the IDEXX SNAP 4Dx test. A total of 107/714 (15%) had antibodies reactive to B. lonestari, and prevalence of antibodies was higher in deer from southern states (17.5%) than in deer from northern states (9.2%). Using the SNAP 4DX test, we found that 73/723 (10%) were positive for B. burgdorferi, and significantly more northern deer (23.9%) were positive compared with southern deer (3.8%). Our data demonstrate that WTD are exposed to both Borrelia species, but antibody prevalence for exposure to the two species differs regionally and distributions correlate with the presence of Ixodes scapularis and A. americanum ticks. PMID- 19874185 TI - Evaluation of a dengue IgG indirect enzyme-linked immunosorbent assay and a Japanese encephalitis IgG indirect enzyme-linked immunosorbent assay for diagnosis of secondary dengue virus infection. AB - To establish a new method for the diagnosis of dengue secondary infection, 187 serum samples from the patients with dengue secondary infection, 40 serum samples from the patients with dengue primary infection, and 44 serum samples from the healthy volunteers were tested using the dengue IgG indirect enzyme-linked immunosorbent assay (DEN IgG ELISA). The results of the test were compared with those from the dengue hemagglutination inhibition (DEN HI) test, which has been recommended as the gold standard by the World Health Organization (WHO, 1997). Japanese encephalitis IgG indirect ELISA (JE IgG ELISA) was also performed to measure anti-flavivirus IgG, which cross-reacts with the Japanese encephalitis virus, to test the possibility of an alternative to DEN IgG ELISA. The results of DEN IgG and JE IgG ELISAs were highly correlated with those of the DEN HI test. In the DEN IgG ELISA, a titer of 1:29,000 was the cut-off value for the diagnosis of dengue secondary infection (91.5% accuracy [95% confidence interval, CI], 90.9% sensitivity [95%CI], and 92.9% specificity [95%CI]). A titer of 1:52,000 was the cut-off value for dengue secondary infection using JE IgG ELISA (95.6% accuracy [95%CI], 98.9% sensitivity [95%CI], and 88.1% specificity [95%CI]). In conclusion, this study confirmed that the results of both DEN IgG and JE IgG ELISAs were highly correlated with the results of DEN HI test. Thus, these ELISAs are simple, rapid, sensitive, and quantitative tests that can be used in the determination of dengue secondary infection. PMID- 19874186 TI - Cervical lymphadenitis in a patient coinfected with Toxoplasma gondii and Bartonella henselae. AB - Cat scratch disease, caused by Bartonella henselae, is a worldwide zoonosis that is most frequently associated with the bite or scratch of a kitten under 6 months of age, as well as from a fleabite. Toxoplsma gondii is also another important zoonotic agent in cats and humans, which is mainly acquired by ingestion of food or water that is contaminated with oocytes shed by cats or by eating undercooked or raw meat containing tissue cysts. Here, we report a first case of young patient with cervical lymphadenitis, which shows serological and histological evidence of B. henselae and T. gondii coinfection in Korea with literature review. PMID- 19874187 TI - Emergence of chikungunya virus infection in Orissa, India. AB - From September through October 2006, an unknown disease characterized by acute onset of fever, joint pain with or without swelling, and maculopapular rash along with fatigue was reported from three villages of Cuttack and one village of Kendrapara district of Orissa, India, by the State Health Department. Upon learning this, a team from Regional Medical Research Centre (Indian Council of Medical Research), Bhubaneswar, Orissa, conducted an epidemiological investigation in the area. Household survey was carried out and clinical examination of the symptomatic individuals (n = 1289: Kendrapara, 752; Cuttack, 537) undertaken. Based on the recorded chikungunya (CHIK) fever symptoms, a vector-borne viral disease was considered for provisional diagnosis. Blood samples were collected from 217 symptomatic individuals; to confirm the diagnosis, sera were tested for anti-CHIK antibody (immunoglobulin M), which revealed 63% (64/101) and 40% (47/116) seropositivity in the samples from Kendrapara and Cuttack district, respectively. The illness was managed with analgesics like paracetamol. No death was recorded due to the illness. Entomological survey in the areas revealed the presence of Aedes mosquitoes: aegypti, albopictus, and vittatus. The per-man-hour density of Aedes vectors ranged from 0.8 to 7.6. High larval indices, house index >17% and Breteau index >70%, also indicated Aedes breeding in the area. The investigation documented circulation of CHIK in Orissa, India, and helped to take preventive steps in the outbreak area, with the suggested vector control measures. PMID- 19874188 TI - Wash-resistance and field efficacy of Olyset net, a permethrin-incorporated long lasting insecticidal netting, against Anopheles minimus-transmitted malaria in Assam, Northeastern India. AB - INTRODUCTION: The long-lasting insecticidal nets are ready-to-use, pretreated nets, which do not require retreatment for 4-5 years. Olyset nets that are made of high-density polyethylene monofilament yarn with 2% w/w permethrin incorporated (corresponding to 1 g/m(2)) are type-2 in which insecticide is incorporated into the polymers and are wash resistant. In these, insecticide migrates to the surface of the netting fiber to be bioavailable against mosquitoes and other insect pests. STUDY SITE AND OBJECTIVES: The present study was a village scale, field-based trial that was conducted in Plasmodium falciparum predominant area of Assam to assess feasibility, acceptability, and sustainability of this intervention against vector populations and disease transmission. We here report the research findings of Olyset net as an intervention against Anopheles minimus-transmitted malaria in foothill area of Assam for the first year of observations beginning July 2005 till June 2006. RESULTS: An. minimus, the mosquito vector species, was observed to be fully susceptible to permethrin. Follow-up investigations revealed that An. minimus mosquitoes had virtually disappeared in Olyset net villages, which was corroborated by data on human bait mosquito-landing catches. There was a consistent decline in the malarial incidence in Olyset net intervention villages, and the overall impact on the malarial transmission was significant compared to untreated net and no-net control villages for the corresponding study period. The bioavailability of insecticide on Olyset netting fiber was consistent (100% kill effect) up to 10 months of monitoring, and was observed to be wash resistant even after the 20th wash at fortnightly intervals. CONCLUSIONS: The Olyset nets were safe to use, wash resistant, and assessed to be operationally feasible, community based intervention for sustainable management of disease vectors against malaria. Community compliance and acceptance was high, and users reported decreased nuisance due to biting mosquitoes. PMID- 19874189 TI - Molecular detection of Ehrlichia chaffeensis and Anaplasma bovis in the salivary glands from Haemaphysalis longicornis ticks. AB - The salivary gland (SG) of tick plays an important role as a route in the dissemination of tick-borne pathogens to their hosts. We evaluated the presence of these pathogens in the SGs of Haemaphysalis longicornis ticks, and these ticks were collected from grazing cattle in Jeju Island, Korea. Of total 463 one-side SGs, 56 (12.1%) SGs were positive for Ehrlichia chaffeensis and 11 (2.4%) were positive for Anaplasma bovis. In addition, two (0.4%) SGs were co-infected with both E. chaffeensis and A. bovis. In conclusion, we specifically describe the presence of E. chaffeensis and A. bovis in the SGs of H. longicornis ticks in Korea. PMID- 19874190 TI - Ecology of hantaviruses and their hosts in North America. AB - Since the 1993 discovery of a highly pathogenic hantavirus associated with the North American deer mouse (Peromyscus maniculatus), intensive ecological studies have led to many advances in our understanding of the natural history of New World hantaviruses as it relates to human disease. Seventeen named hantaviruses have been identified in North America. Field and laboratory studies of Sin Nombre and other hantaviruses have delineated host associations, geographical distributions, mechanisms of transmission, temporal infection dynamics of these viruses in host populations, and environmental factors that influence these dynamics. Using data from these studies, preliminary predictive models of the risk of hantavirus infection to humans have been developed. Improved models using satellite-derived data are under development. Multidisciplinary collaboration, integration of field and laboratory studies, and establishment and maintenance of long-term monitoring studies will be critical to continued advancement in the understanding of hantavirus-host ecology and disease prevention in humans. PMID- 19874191 TI - Binding conformations and QSAR of CA-4 analogs as tubulin inhibitors. AB - A theoretical study on the binding conformations and the quantitative structure activity relationship (QSAR) of combretastatin A4 (CA-4) analogs as inhibitors toward tubulin has been carried out using docking analysis and comparative molecular field analysis (CoMFA). The appropriate binding orientations and conformations of these compounds interacting with tubulin were revealed by the docking study; and a 3D-QSAR model showing significant statistical quality and satisfactory predictive ability was established, in which the correlation coefficient (R(2)) and cross-validation coefficient (q(2)) were 0.955 and 0.66, respectively. The same model was further applied to predict the pIC(50) values for 16 congeneric compounds as external test set, and the predictive correlation coefficient R(2)(pred) reached 0.883. Other tests on additional validations further confirmed the satisfactory predictive power of the model. In this work, it was very interesting to find that the 3D topology structure of the active site of tubulin from the docking analysis was in good agreement with the 3D-QSAR model from CoMFA for this series of compounds. Some key structural factors of the compounds responsible for cytotoxicity were reasonably presented. These theoretical results can offer useful references for understanding the action mechanism and directing the molecular design of this kind of inhibitor with improved activity. PMID- 19874192 TI - DNA vaccination of American robins (Turdus migratorius) against West Nile virus. AB - West Nile virus (WNV) has caused at least 1150 cases of encephalitis, 100 deaths, and an estimated 30,000-80,000 illnesses in 6 of the last 7 years. Recent evidence from several regions has implicated American robins (Turdus migratorius) as an important host for feeding by Culex mosquitoes, and, when integrated with their host competence for WNV, demonstrates that they are a key WNV amplification host. We evaluated the efficacy of a DNA plasmid vaccine at reducing the viremia and infectiousness of hatch-year American robins. We found that a single dose of vaccine injected intramuscularly resulted in more than a 400-fold (10(2.6)) decrease in average viremia. Although sample sizes were small, these results suggest that vaccinated robins exhibit viremias that are likely to be mostly noninfectious to biting Culex mosquitoes. More broadly, if an orally effective formulation of this vaccine could be developed, new control strategies based on wildlife vaccination may be possible. PMID- 19874194 TI - Larvicidal effects of the major essential oil of Pittosporum tobira against Aedes aegypti (L.). AB - Essential oil obtained from the leaves of Pittosporum tobira was extracted and its chemical composition and larvicidal effects were studied. Analyses were conducted by gas chromatography and mass spectroscopy (GC-MS) to determine the primary constituents of the essential oil of P. tobira. The yield of P. tobira essential oil (PTEO) was 0.1%, and GC-MS analysis identified its major constituents as undecane (31.11%), 4-methyl-1,3-pentadiene (11.34%), (1,3 dimethyl-2-butenyl)benzene (5.45%), and L-limonene (14.08%). The essential oil had a significant toxic effect against early fourth-stage larvae of Aedes aegypti (L.), with an LC(50) value of 58.92 ppm and an LC(90) value of 111.31 ppm. Finally, the LC(50) and LC(90) values of L-limonene were 39.7 ppm and 78.11 ppm. These results could be useful for seeking newer, safer, and more effective natural larvicidal agents against A. aegypti. PMID- 19874193 TI - Kinetic analysis of substrate utilization by native and TNAP-, NPP1-, or PHOSPHO1 deficient matrix vesicles. AB - During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Here, we have studied phosphosubstrate catalysis by osteoblast derived MVs at physiologic pH, analyzing the hydrolysis of ATP, ADP, and PP(i) by isolated wild-type (WT) as well as TNAP-, NPP1- and PHOSPHO1-deficient MVs. Comparison of the catalytic efficiencies identified ATP as the main substrate hydrolyzed by WT MVs. The lack of TNAP had the most pronounced effect on the hydrolysis of all physiologic substrates. The lack of PHOSPHO1 affected ATP hydrolysis via a secondary reduction in the levels of TNAP in PHOSPHO1-deficient MVs. The lack of NPP1 did not significantly affect the kinetic parameters of hydrolysis when compared with WT MVs for any of the substrates. We conclude that TNAP is the enzyme that hydrolyzes both ATP and PP(i) in the MV compartment. NPP1 does not have a major role in PP(i) generation from ATP at the level of MVs, in contrast to its accepted role on the surface of the osteoblasts and chondrocytes, but rather acts as a phosphatase in the absence of TNAP. PMID- 19874195 TI - Strontium is incorporated into mineral crystals only in newly formed bone during strontium ranelate treatment. AB - Strontium ranelate has been shown to increase bone mass in postmenopausal osteoporosis patients and to reduce fracture risk. The aim of this study was to investigate the potential influence of strontium ranelate (Protelos) treatment on human bone tissue characteristics and quality at the micro- and nanostructural levels. We investigated transiliac biopsies from patients treated for 36 months with strontium ranelate or placebo (n = 5 per group) using synchrotron radiation with a microbeam combining scanning small-angle scattering, X-ray diffraction, and fluorescence spectroscopy (SAXS/XRD/XRF) for a detailed characterization of the mineral crystals within the collagenous bone matrix. A scanning procedure allowed the simultaneous determination of maps of the chemical composition together with thickness, length, and lattice spacing of these mineral crystals within each of the 15- or 25-microm-wide pixels in a thin bone section. The fluorescence results show that only bone packets or osteons formed during the strontium ranelate treatment contain significant amounts of strontium and that up to 0.5 of 10 calcium atoms in the mineral crystals are replaced by strontium, as revealed by a corresponding shift in apatite lattice spacing. The thickness and length of the plate-shaped bone mineral crystals were not affected by the strontium ranelate treatment. As a consequence, there was no indication for a change in human bone tissue quality at the nanoscale after a 36-month treatment of postmenopausal osteoporotic women with strontium ranelate, except for a partial replacement of calcium by strontium ions in the hydroxyapatite crystals, only in newly formed bone. PMID- 19874196 TI - Cbp recruitment of Csk into lipid rafts is critical to c-Src kinase activity and bone resorption in osteoclasts. AB - A tyrosine kinase, c-Src, that plays an indispensable role in ruffled border formation and bone resorption is constitutively active in osteoclasts. However, to date, the molecular mechanism underlying increased c-Src activity in osteoclasts is unknown. To address this, we first examined the expression levels and subcellular localization of Csk, a negative regulatory kinase for c-Src. We found that the expression level of Csk in osteoclasts was comparable with that of other tissues. However, in osteoclasts, Csk was hardly localized in lipid rafts, where c-Src is highly expressed. Interestingly, expression of Cbp, which recruits Csk into lipid rafts through physical interaction with Csk, was very low in osteoclasts compared with other tissues. To understand the importance of Cbp in osteoclasts, we introduced Cbp into osteoclasts using an adenovirus gene delivery system. Introduction of Cbp stimulated recruitment of Csk into lipid rafts and suppressed c-Src activity in a dose-dependent manner. Furthermore, introduction of Cbp markedly inhibited formation of actin rings and bone-resorbing activity in osteoclasts. In addition, treatment with RANKL and overexpression of TRAF6 or NFAT2 inhibited Cbp expression in the osteoclastogenic cell line RAW264.7 along with osteoclastic differentiation. NFAT2 overexpression also inhibited Cbp expression in spleen macrophages. Collectively, our results indicate that reduction in Cbp expression is responsible for maintaining high c-Src activity in osteoclasts. These findings contribute to an understanding of the unique regulatory system for c-Src in osteoclasts. PMID- 19874197 TI - Bone microstructure at the distal tibia provides a strength advantage to males in late puberty: an HR-pQCT study. AB - Bone is a complex structure with many levels of organization. Advanced imaging tools such as high-resolution (HR) peripheral quantitative computed tomography (pQCT) provide the opportunity to investigate how components of bone microstructure differ between the sexes and across developmental periods. The aim of this study was to quantify the age- and sex-related differences in bone microstructure and bone strength in adolescent males and females. We used HR-pQCT (XtremeCT, Scanco Medical, Geneva, Switzerland) to assess total bone area (ToA), total bone density (ToD), trabecular bone density (TrD), cortical bone density (CoD), cortical thickness (Cort.Th), trabecular bone volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular spacing standard deviation (Tb.Sp SD), and bone strength index (BSI, mg2/mm4) at the distal tibia in 133 females and 146 males (15 to 20 years of age). We used a general linear model to determine differences by age- and sex group and age x sex interactions (p<0.05). Across age categories, ToD, CoD, Cort.Th, and BSI were significantly lower at 15 and 16 years compared with 17 to 18 and 19 to 20 years in males and females. There were no differences in ToA, TrD, and BV/TV across age for either sex. Between sexes, males had significantly greater ToA, TrD, Cort.Th, BV/TV, Tb.N, and BSI compared with females; CoD and Tb.Sp SD were significantly greater for females in every age category. Males' larger and denser bones confer a bone-strength advantage from a young age compared with females. These structural differences could represent bones that are less able to withstand loads in compression in females. PMID- 19874198 TI - Odanacatib, a cathepsin-K inhibitor for osteoporosis: a two-year study in postmenopausal women with low bone density. AB - Cathepsin K, a cysteine protease expressed in osteoclasts, degrades type 1 collagen. Odanacatib selectively and reversibly inhibited cathepsin K and rapidly decreased bone resorption in preclinical and phase I studies. A 1-year dose finding trial with a 1-year extension on the same treatment assignment was performed in postmenopausal women with low bone mineral density (BMD) to evaluate the safety and efficacy of weekly doses of placebo or 3, 10, 25, or 50 mg of odanacatib on BMD and biomarkers of skeletal remodeling. Women with BMD T-scores of -2.0 or less but not less than -3.5 at the lumbar spine or femoral sites were randomly assigned to receive placebo or one of four doses of odanacatib; all received vitamin D with calcium supplementation as needed. The primary endpoint was percentage change from baseline lumbar spine BMD. Other endpoints included percentage change in BMD at hip and forearm sites, as well as changes in biomarkers of skeletal remodeling. Twenty-four months of treatment produced progressive dose-related increases in BMD. With the 50-mg dose of odanacatib, lumbar spine and total-hip BMD increased 5.5% and 3.2%, respectively, whereas BMD at these sites was essentially unchanged with placebo (-0.2% and -0.9%). Biochemical markers of bone turnover exhibited dose-related changes. The safety and tolerability of odanacatib generally were similar to those of placebo, with no dose-related trends in any adverse experiences. In summary, 2 years of weekly odanacatib treatment was generally well-tolerated and increased lumbar spine and total-hip BMD in a dose-related manner in postmenopausal women with low BMD. PMID- 19874199 TI - Transfer, analysis, and reversion of the fibrous dysplasia cellular phenotype in human skeletal progenitors. AB - Human skeletal progenitors were engineered to stably express R201C mutated, constitutively active Gs alpha using lentiviral vectors. Long-term transduced skeletal progenitors were characterized by an enhanced production of cAMP, indicating the transfer of the fundamental cellular phenotype caused by activating mutations of Gs alpha. Like skeletal progenitors isolated from natural fibrous dysplasia (FD) lesions, transduced cells could generate bone but not adipocytes or the hematopoietic microenvironment on in vivo transplantation. In vitro osteogenic differentiation was noted for the lack of mineral deposition, a blunted upregulation of osteocalcin, and enhanced upregulation of other osteogenic markers such as alkaline phosphatase (ALP) and bone sialoprotein (BSP) compared with controls. A very potent upregulation of RANKL expression was observed, which correlates with the pronounced osteoclastogenesis observed in FD lesions in vivo. Stable transduction resulted in a marked upregulation of selected phosphodiesterase (PDE) isoform mRNAs and a prominent increase in total PDE activity. This predicts an adaptive response in skeletal progenitors transduced with constitutively active, mutated Gs alpha. Indeed, like measurable cAMP levels, the differentiative responses of transduced skeletal progenitors were profoundly affected by inhibition of PDEs or lack thereof. Finally, using lentiviral vectors encoding short hairpin (sh) RNA interfering sequences, we demonstrated that selective silencing of the mutated allele is both feasible and effective in reverting the aberrant cAMP production brought about by the constitutively active Gs alpha and some of its effects on in vitro differentiation of skeletal progenitors. PMID- 19874200 TI - Impaired osteoblast function in GPRC6A null mice. AB - GPRC6A is a widely expressed orphan G protein-coupled receptor that senses extracellular amino acids, osteocalcin, and divalent cations in vitro. GPRC6A null (GPRC6A(-/-)) mice exhibit multiple metabolic abnormalities including osteopenia. To investigate whether the osseous abnormalities are a direct function of GPRC6A in osteoblasts, we examined the function of primary osteoblasts and bone marrow stromal cell cultures (BMSCs) in GPRC6A(-/-) mice. We confirmed that GPRC6A(-/-) mice exhibited a decrease in bone mineral density (BMD) associated with reduced expression of osteocalcin, ALP, osteoprotegerin, and Runx2-II transcripts in bone. Osteoblasts and BMSCs derived from GPRC6A(-/-) mice exhibited an attenuated response to extracellular calcium-stimulated extracellular signal-related kinase (ERK) activation, diminished alkaline phosphatase (ALP) expression, and impaired mineralization ex vivo. In addition, siRNA-mediated knockdown of GPRC6A in MC3T3 osteoblasts also resulted in a reduction in extracellular calcium-stimulated ERK activity. To explore the potential relevance of GPRC6A function in humans, we looked for an association between GPRC6A gene polymorphisms and BMD in a sample of 1000 unrelated American Caucasians. We found that GPRC6A gene polymorphisms were significantly associated with human spine BMD. These data indicate that GRPC6A directly participates in the regulation of osteoblast-mediated bone mineralization and may mediate the anabolic effects of extracellular amino acids, osteocalcin, and divalent cations in bone. PMID- 19874201 TI - Age-dependence of femoral strength in white women and men. AB - Although age-related variations in areal bone mineral density (aBMD) and the prevalence of osteoporosis have been well characterized, there is a paucity of data on femoral strength in the population. Addressing this issue, we used finite element analysis of quantitative computed tomographic scans to assess femoral strength in an age-stratified cohort of 362 women and 317 men, aged 21 to 89 years, randomly sampled from the population of Rochester, MN, and compared femoral strength with femoral neck aBMD. Percent reductions over adulthood were much greater for femoral strength (55% in women, 39% in men) than for femoral neck aBMD (26% in women, 21% in men), an effect that was accentuated in women. Notable declines in strength started in the mid-40s for women and one decade later for men. At advanced age, most of the strength deficit for women compared with men was a result of this decade-earlier onset of strength loss for women, this factor being more important than sex-related differences in peak bone strength and annual rates of bone loss. For both sexes, the prevalence of "low femoral strength" (<3000 N) was much higher than the prevalence of osteoporosis (femoral neck aBMD T-score of -2.5 or less). We conclude that age-related declines in femoral strength are much greater than suggested by age-related declines in femoral neck aBMD. Further, far more of the elderly may be at high risk of hip fracture because of low femoral strength than previously assumed based on the traditional classification of osteoporosis. PMID- 19874202 TI - Processing of the NF-kappa B2 precursor p100 to p52 is critical for RANKL-induced osteoclast differentiation. AB - Gene targeting of the p50 and p52 subunits of NF-kappaB has shown that NF-kappaB plays a critical role in osteoclast differentiation. However, the molecular mechanism by which NF-kappaB regulates osteoclast differentiation is still unclear. To address this issue, we analyzed alymphoplasia (aly/aly) mice in which the processing of p100 to p52 does not occur owing to an inactive form of NF kappaB-inducing kinase (NIK). Aly/aly mice showed a mild osteopetrosis with significantly reduced osteoclast numbers. RANKL-induced osteoclastogenesis from bone marrow cells of aly/aly mice also was suppressed. RANKL still induced the degradation of I kappaB alpha and activated classical NF-kappaB, whereas processing of p100 to p52 was abolished by the aly/aly mutation. Moreover, RANKL induced expression of NFATc1 was impaired in aly/aly bone marrow. Overexpression of constitutively active IKK alpha or p52 restored osteoclastogenesis in aly/aly cells. Finally, transfection of either wild-type p100, p100 Delta GRR that cannot be processed to p52, or p52 into NF-kappaB 2-deficient cells followed by RANKL treatment revealed a strong correlation between the number of osteoclasts induced by RANKL and the ratio of p52 to p100 expression. Our data provide a new finding for a previously unappreciated role for NF-kappaB in osteoclast differentiation. PMID- 19874203 TI - Capacity of omega-3 fatty acids or eicosapentaenoic acid to counteract weightlessness-induced bone loss by inhibiting NF-kappaB activation: from cells to bed rest to astronauts. AB - NF-kappaB is a transcriptional activator of many genes, including some that lead to muscle atrophy and bone resorption-significant concerns for astronauts. NF kappaB activation is inhibited by eicosapentaenoic acid (EPA), but the influence of this omega-3 fatty acid on the effects of weightlessness are unknown. We report here cellular, ground analogue, and spaceflight findings. We investigated the effects of EPA on differentiation of RAW264.7 monocyte/macrophage cells induced by receptor activator of NF-kappaB ligand (RANKL) and on activation of NF kappaB by tumor necrosis factor alpha (TNF-alpha) or exposure to modeled weightlessness. EPA (50 microM for 24 hours) inhibited RANKL-induced differentiation and decreased activation of NF-kappaB induced by 0.2 microg/mL of TNF-alpha for 30 minutes or by modeled weightlessness for 24 hours (p < .05). In human studies, we evaluated whether NF-kappaB activation was altered after short duration spaceflight and determined the relationship between intake of omega-3 fatty acids and markers of bone resorption during bed rest and the relationship between fish intake and bone mineral density after long-duration spaceflight. NF kappaB was elevated in crew members after short-duration spaceflight, and higher consumption of fish (a rich source of omega-3 fatty acids) was associated with reduced loss of bone mineral density after flight (p < .05). Also supporting the cell study findings, a higher intake of omega-3 fatty acids was associated with less N-telopeptide excretion during bed rest (Pearson r = -0.62, p < .05). Together these data provide mechanistic cellular and preliminary human evidence of the potential for EPA to counteract bone loss associated with spaceflight. PMID- 19874204 TI - IL21R and PTH may underlie variation of femoral neck bone mineral density as revealed by a genome-wide association study. AB - Bone mineral density (BMD) measured at the femoral neck (FN) is the most important risk phenotype for osteoporosis and has been used as a reference standard for describing osteoporosis. The specific genes influencing FN BMD remain largely unknown. To identify such genes, we first performed a genome-wide association (GWA) analysis for FN BMD in a discovery sample consisting of 983 unrelated white subjects. We then tested the top significant single-nucleotide polymorphisms (SNPs; 175 SNPs with p < 5 x 10(-4)) for replication in a family based sample of 2557 white subjects. Combing results from these two samples, we found that two genes, parathyroid hormone (PTH) and interleukin 21 receptor (IL21R), achieved consistent association results in both the discovery and replication samples. The PTH gene SNPs, rs9630182, rs2036417, and rs7125774, achieved p values of 1.10 x 10(-4), 3.24 x 10(-4), and 3.06 x 10(-4), respectively, in the discovery sample; p values of 6.50 x 10(-4), 5.08 x 10(-3), and 5.68 x 10(-3), respectively, in the replication sample; and combined p values of 3.98 x 10(-7), 9.52 x 10(-6), and 1.05 x 10(-5), respectively, in the total sample. The IL21R gene SNPs, rs8057551, rs8061992, and rs7199138, achieved p values of 1.51 x 10(-4), 1.53 x 10(-4), and 3.88 x 10(-4), respectively, in the discovery sample; p values of 2.36 x 10(-3), 6.74 x 10(-3), and 6.41 x 10(-3), respectively, in the replication sample; and combined p values of 2.31 x 10(-6), 8.62 x 10(-6), and 1.41 x 10(-5), respectively, in the total sample. The effect size of each SNP was approximately 0.11 SD estimated in the discovery sample. PTH and IL21R both have potential biologic functions important to bone metabolism. Overall, our findings provide some new clues to the understanding of the genetic architecture of osteoporosis. PMID- 19874206 TI - Synthesis and biological activity of progesterone derivatives as 5alpha-reductase inhibitors, and their effect on hamster prostate weight. AB - In this study, we report the synthesis and biological evaluation of four 6- and 17-substituted progesterone derivatives (7-10). These compounds were prepared from the commercially available 17alpha-acetoxyprogesterone. The biological effect of these steroids was demonstrated in in vivo as well as in vitro experiments. In the in vivo experiments, we measured the activity of 6-10 on the weight of the prostate glands of gonadectomized hamsters treated with testosterone (T). For the studies in vitro, we determined the IC(50) value by measuring the concentration of steroidal derivative that inhibited 50% of the activity of 5alpha-reductase present in the human prostate. The results from this work indicated that compounds 6-9 significantly decreased the weight of the prostate as compared to testosterone-treated animals and this reduction of prostate weight was comparable to that produced by finasteride. Steroid 8 was the most effective of the tested compounds. However, compound 10 did not exhibit this capacity. On the other hand, 6-9 exhibited a high inhibitory activity for the human 5alpha-reductase enzyme with IC(50) values of 10, 70, 22, and 19 nM, respectively. However, 10 was not effective for the inhibition of 5alpha reductase activity. In conclusion, the compounds that contained the acetate ester moiety in the molecule (6, 7, 8, and 9) inhibited the activity of 5alpha reductase and decreased the weight of the prostate. Nevertheless, the double bond in ring B seems to diminish the inhibitory potency (7 and 9), since 6, which does not possess a double bond at C-6, had the highest inhibitory activity (the lowest IC(50) value). PMID- 19874205 TI - Actinomyces in chronic granulomatous disease: an emerging and unanticipated pathogen. AB - BACKGROUND: Chronic granulomatous disease (CGD) is a rare inherited disease of the phagocyte NADPH oxidase system that causes defective production of toxic oxygen metabolites, impaired bacterial and fungal killing, and recurrent life threatening infections, mostly by catalase-producing organisms. We report for the first time, to our knowledge, chronic infections with Actinomyces species in 10 patients with CGD. Actinomycosis is a chronic granulomatous condition that commonly manifests as cervicofacial, pulmonary, or abdominal disease, caused by slowly progressive infection with oral and gastrointestinal commensal Actinomyces species. Treatment of actinomycosis is usually simple in immunocompetent individuals, requiring long-term, high-dose intravenous penicillin, but is more complicated in those with CGD because of delayed diagnosis and an increased risk of chronic invasive or debilitating disease. METHODS: Actinomyces was identified by culture, staining, 16S ribosomal DNA polymerase chain reaction, and/or a complement fixation test in 10 patients with CGD. RESULTS: All 10 patients presented with a history of fever and elevated inflammatory signs without evident focus. Diagnosis was delayed and clinical course severe and protracted despite high-dose intravenous antibiotic therapy and/or surgery. These results suggest an unrecognized and unanticipated susceptibility to weakly pathogenic Actinomyces species in patients with CGD because these are catalase-negative organisms previously thought to be nonpathogenic in CGD. CONCLUSIONS: Actinomycosis should be vigorously sought and promptly treated in patients with CGD presenting with uncommon and prolonged clinical signs of infection. Actinomycosis is a catalase negative infection important to consider in CGD. PMID- 19874207 TI - A FRET-based microplate assay for human protein kinase CK2, a target in neoplastic disease. AB - Besides cardiovascular diseases, cancer represents the major cause of death in developed countries. In many different human tumors, increased activity of serine/threonine protein kinase CK2 has been detected, and recent in vivo studies support a direct involvement of CK2 in tumor progression. Therefore, potent compounds to decrease CK2 activity to a non-pathogenic level would be a promising effort toward an antineoplastic therapy. In this study, an alternative to the established radiometric phosphorylation assay for quantification of CK2 activity was developed. For this purpose, the substrate peptide RRRDDDSDDD was coupled at the C-terminus to the fluorophore EDANS (5-[(2-aminoethyl)amino]naphthalene-1 sulfonic acid) and at the N-terminus to the quencher DABCYL (4-(4 dimethylaminophenylazo)benzoic acid). This resulted in quenched fluorescence of EDANS due to a FRET-based effect. After proteolytic cleavage of the peptide by elastase, the quenching effect was reduced and, as a consequence, fluorescence was increased. Because elastase is supposed to cleave at the S/D site of the peptide, phosphorylation of serine by CK2 hampered substrate binding of elastase and blocked the increase in fluorescence by proteolytic cleavage. This means that the new assay to quantify human CK2 activity is based on the differential accessibility of the proteolytic cleavage site, which is dependent on kinase phosphorylation. It could be used to measure inhibition of the human target in neoplastic diseases by the compounds TBB (4,5,6,7-tetrabromobenzotriazole) and Emodin. PMID- 19874208 TI - Prediction of acute toxicity in fish by using QSAR methods and chemical modes of action. AB - Three quantitative structure-activity relationship (QSAR) models were evaluated for their power to predict the toxicity of chemicals in two datasets: (1) EPAFHM (US Environmental Protection Agency-Fathead Minnow) and (2) derivatives having a high production volume (HPV), as compiled by the European Chemical Bureau. For all three QSAR models, the quality of the predictions was found to be highly dependent on the mode of action of the chemicals. An analysis of outliers from the three models gives some clues for improving the QSAR models. Two classification methods, Toxtree and a Bayesian approach with fingerprints as descriptors, were also analyzed. Predictions following the Toxtree classification for narcosis were good, especially for the HPV set. The learning model (Bayesian approach) produced interesting results for the EPAFHM dataset but gave lower quality predictions for the HPV set. PMID- 19874209 TI - New insights into homopiperazine-based 5-HT1A/5-HT7R ligands: synthesis and biological evaluation. AB - The synthesis of new N-homopiperazinyl-based ligands is reported. Various structural modifications along with the corresponding biological activities on 5 HT(1A)/5-HT(7) receptors give further insights into this class of serotoninergic ligands. Among the tested central heterocyles, the 7-azaindole gave the best results on the above-mentioned receptors. PMID- 19874210 TI - High-resolution optical coherence tomography correlates in ischemic radiation retinopathy. AB - PURPOSE: To find the abnormalities in various retinal layers caused by radiation retinopathy using spectral domain optical coherence tomography (SD-OCT). METHODS: We report a case of radiation retinopathy that was imaged using SD-OCT Copernicus (Optopol, Zawiercie, Poland). Analysis and synthesis of the OCT image were done using information both at the fovea and 2.5 mm temporal to the fovea. RESULTS: The layers that were reduced in thickness included the inner plexiform layer (47 microm vs. 74 microm), the inner nuclear layer (17 microm vs. 48 microm), and the outer plexiform layer (25 microm vs. 45 microm), whereas the layers with comparable thickness included the nerve fiber layer (24 microm vs. 25 microm), the outer nuclear layer (42 microm vs. 43 microm), the outer segment-inner segment junction (52 microm vs. 54 microm), and the retinal pigment epithelium (RPE) choriocapillaris layer (30 microm vs. 28 microm). CONCLUSION: This report suggests that the radiation-induced damage was confined to the inner layers of the retina. However, secondary outer retinal layer changes may also occur, as suggested by functional derangements. PMID- 19874211 TI - Modifying chromatin architecture during the response to DNA breakage. AB - The human genome is compacted in a dynamic macromolecular complex, chromatin, whose structure presents a considerable barrier to the cellular machinery which responds to DNA double-strand breaks. This review discusses current understanding of the processes that modify chromatin architecture to enable, first, the sensing of DNA breakage, next, the assembly of the protein complexes that resolve the lesion, and finally, the restoration of epigenetic marks after its repair. The importance of these fundamental biological processes is underscored by the growing appreciation that they are aberrant in human diseases, and that their modulation could provide new approaches to disease therapy. PMID- 19874212 TI - Needs, barriers and facilitators experienced by spouses of people with aphasia. AB - PURPOSE: Little is known about how spouses cope with their needs as a result of their partner's aphasia. This study described spouses' needs and identified the barriers and facilitators to satisfying them. METHODS: Four associations of people with aphasia were approached. Eleven spouses were interviewed in small groups. They described the results of their inquiries and efforts to satisfy their needs because their partner had aphasia (mean time since onset 6 years 8 months) as a result of stroke or surgery. Discussions were transcribed and coded. Excerpts were grouped into categories. RESULTS: Spouses mainly needed support and respite, and perceived their partner to need help for communication and well being. Personal factors like the availability of close others to provide help were facilitating. However, participants encountered barriers, mainly organisational, i.e. the help needed did not exist. Some needs persisted over time. CONCLUSIONS: Results confirm the long-term needs of spouses in adjusting to the aphasia of their partner, as well as the limited services available to them. Many of the needs reflected spouses' concerns about their partner, while others were a consequence of their caregiving role as well as the unavailability of support. Spouses of people with aphasia should have access to support during and after rehabilitation. PMID- 19874213 TI - Client and therapist views on exercise programmes for early-mid stage Parkinson's disease and Huntington's disease. AB - PURPOSE: Physiotherapists frequently prescribe home exercise programmes for individuals with Parkinson's disease (PD) and Huntington's disease (HD); however, little is known about clients' perceptions of such programmes and any barriers that may affect participation and compliance. METHOD: A qualitative design was used to capture the attitudes and experiences of people with early-mid stage HD and PD, and with physiotherapists who have experience in neurodegenerative diseases. Two focus groups were conducted for physiotherapists (n = 8); individual interviews were conducted for clients with HD and PD (n = 10). Conversations were digitally recorded and transcribed, and transcriptions were analysed using grounded theory and validated through researcher triangulation. Concepts were categorised according to emerging themes and findings were verified by participants. RESULTS: Both groups cited several barriers to engagement in exercise programmes, which included disease-specific impairments, individual safety and the location at which exercising takes place. Therapists felt that a client's cognition could affect their ability to participate in an exercise programme. Therapists and clients offered a number of strategies to overcome barriers to exercise. CONCLUSIONS: Therapists should work in collaboration with clients to evaluate their individual considerations, identify barriers to exercise and design a client-specific programme that is acceptable and feasible for the client. PMID- 19874214 TI - Assessing the effects of subthalamic nucleus stimulation on gait and mobility in people with Parkinson disease. AB - PURPOSE: To determine the effects of unilateral and bilateral subthalamic nucleus (STN) stimulation on gait and mobility in persons with Parkinson disease (PD). METHOD: We examined eight individuals with advanced PD who underwent staged stimulator implantation surgeries. Gait and mobility were assessed in the medication-on state with a variety of clinical and laboratory measures (Unified Parkinson Disease Rating Scale items, Timed Up and Go Test, gait speed) at three time points: prior to surgery, after the first surgery (unilateral stimulation) and after the second surgery (bilateral stimulation). RESULTS: Despite overall improvements in motor function and reduction of dyskinesia, there were no significant group effects of unilateral or bilateral stimulation on gait and mobility compared to pre-surgical function. However, there were clinically meaningful changes, both improvements and declines, at the individual level. CONCLUSIONS: Because of the consequences of gait deficits and mobility limitations for people with PD, future research should examine the effects of STN stimulation on gait in the medication-on state using sensitive and specific measures such as gait speed. Accurate assessment of gait changes is necessary to improve the evaluation of STN effects and the prediction of individuals in need of rehabilitation services to manage gait and mobility deficits. PMID- 19874215 TI - Elevated plasma concentration of NO and cGMP may be responsible for the decreased platelet aggregation and platelet leukocyte conjugation in platelets hypo responsive to catecholamines. AB - Impaired responsiveness to epinephrine and other catecholamines (CA) were previously reported in platelets of 20 approximately 30% healthy Japanese and Koreans. In the present study, the possible mechanisms of different responsiveness to CA in platelets of CA hypo-responders (CA-HY) and CA good responders (CA-GR) were investigated. Increased platelet-leukocyte conjugate (PLC) formations were observed with whole blood of CA-GR than with that of CA-HY in both non-stimulated [mean fluorescence intensity (MFI) values: 1.33 +/- 0.26 vs. 1.16 +/- 0.19] and ADP (MFI: 5.54 +/- 3.46 vs. 2.15 +/- 1.13) or TRAP (MFI: 5.11 +/- 2.32 vs. 3.38 +/- 1.47) activated states. The platelets of CA-GR, when stimulated with ADP (10 microM), released approximately twice the amount of ATP than those of CA-HY (0.88 +/- 0.65 and 0.45 +/- 0.36 nmole, respectively). Nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels were significantly higher in non-stimulated PRP of CA-HY than in that of CA-GR (70.3 +/- 24.1 microM and 14.1 +/- 4.9 nM vs. 41.1 +/- 15.8 microM and 6.7 +/- 2.4 nM, respectively). The platelet-monocyte conjugation induced with either ADP or TRAP was significantly reduced in CA-GR with the addition of linsidomine, a NO donor, (MFI: 2.78 +/- 0.43 vs. 3.73 +/- 0.90, or 4.28 +/- 0.95 vs. 5.76 +/- 1.33, respectively). Moreover, the degree of platelet aggregation and the ATP secretion induced by epinephrine in CA-GR were significantly retarded with the addition of either linsidomine or 8-Bromo-cGMP (a cGMP analog) with more substantial effects on ATP release than aggregation. The results suggested that elevated NO and/or cGMP plasma levels may be responsible for the lower platelet aggregation and PLC formation observed in CA-HY than that in CA-GR. PMID- 19874216 TI - Pemphigus: the promises of peptide immunotherapy. AB - Pemphigus is caused by IgG autoantibodies directed against desmogleins (Dsg), keratinocyte desmosomal glycoproteins belonging to the cadherin family. Anti-Dsg IgG antibodies interfere with adhesive of desmogleins, causing the detachment of keratinocytes (acantholysis). In our laboratory, an alternative approach to pemphigus immunotherapy has been tested. The peptidic vaccine approach is based on the identification of peptidic epitopes within the sequence of known autoantigens and the use of such peptides to evoke tolerance (as in autoimmune disease) or to boost effector immune mechanisms (as in immunotherapy of tumors). This approach shows that in silico mapping of low-similarity sequences may add to the prediction of peptide immunogenicity. Thus peptide immunotherapy for pemphigus deserve further investigations before joining the therapeutic arsenal for pemphigus and related disorders. PMID- 19874218 TI - The structure, genetic polymorphisms, expression and biological functions of complement receptor type 1 (CR1/CD35). AB - The complement system is comprised of soluble and cell surface associated proteins that recognize exogenous, altered, or potentially harmful endogenous ligands. In recent years, the complement system--particularly component C3 and its receptors--have been demonstrated to be a key link between innate and adaptive immunity. Complement receptor type 1 (CR1), the receptor for C3b/C4b complement peptides, has emerged as a molecule of immense interest in gaining insight to the susceptibility, pathophysiology, diagnosis, prognosis and therapy of such diseases. In this review, we wish to briefly bring forth the structure, genetic polymorphisms, expression and biological functions of CR1. PMID- 19874217 TI - The role of infection and inflammation in sudden infant death syndrome. AB - Sudden Infant Death Syndrome (SIDS) is the most common cause of post-neonatal mortality in the developed world. The exact cause of SIDS is likely to be multifactorial involving a critical developmental period, a vulnerable infant, and one or more triggers. Many SIDS infants have a history of viral illness preceding death. Prone sleep position, one of the leading risk factors, can increase airway temperature, as well as stimulate bacterial colonization and bacterial toxin production. Markers of infection and inflammation are often found on autopsy along with microbial isolates. Although the causal link between infection and SIDS is not conclusive, there is evidence that an infectious insult could be a likely trigger of SIDS in some infants. PMID- 19874219 TI - Follicular development in pregnant cows after the administration of equine chorionic gonadotropin (eCG): a new insight. AB - The follicular development in the cow occurs in a wave-like pattern, and it takes place also during pregnancy. In the cow, Equine Chorionic Gonadotropin (eCG) is used for superovulation, but a decrease in total fertility has been reported, likely because of its immunogenic properties in species other than equine. In this regard, immune response has been implicated in follicular growth, ovulation, and placental development. So, aims of our study are to test the safety of eCG administered during pregnancy and characterize the ovarian activity, the quality of oocytes, the hormonal status, and interleukin levels in eCG-treated pregnant cows. PMID- 19874220 TI - Quantitative determination of pegylated consensus interferon in rhesus monkey serum using a competitive enzyme-linked immunosorbent assay. AB - A competitive enzyme-linked immunosorbent assay (ELISA) with generated mouse anti consensus interferon (CIFN) antibody was developed for quantitative determination of pegylated consensus interferon (PEG-CIFN) in rhesus monkey serum. The operational concentrations of the original assay were determined using the chessboard method. ELISA working range was 10-5000 ng/ml, corresponding to a limit of quantification of 8.4 ng/ml in rhesus monkey serum. In a precision test, intra-assay CV ranged 1.8-9.6% and inter-assay CV ranged 3.5-12.7%. Relative recovery rate of this ELISA assay ranged from 102.65-115.77%, with RSD values ranging from 2.26-5.44%. Three groups of rhesus monkeys received 1250 microg/kg, 300 microg/kg, 150 microg/kg PEG-CIFN by subcutaneous administration, and blood samples were drawn via the femoral vein at the specified time points. PEG-CIFN in rhesus monkey serum was determined using the competitive ELISA, and the results were compared with antiviral activity assay. In conclusion, the competitive ELISA assay we developed has sufficient sensitivity, precision, and accuracy for the analysis of a rhesus monkey serum sample. PMID- 19874221 TI - Chinese herbal medicinal ingredients inhibit secretion of IL-6, IL-8, E-selectin and TXB2 in LPS-induced rat intestinal microvascular endothelial cells. AB - The aim of the research was to investigate the anti-inflammatory mechanism of Pulsatillae Decoction (PD), the levels of interleukin (IL)-6, IL-8, E-selectin, and thromboxane B(2) (TXB(2)) secreted by cultured rat intestinal microvascular endothelial cells (RIMECs) were determined after treatment with its active ingredients, namely anemoside B4, anemonin, berberine, jatrorrhizine, palmatine, aesculin, and esculetin. RIMECs were challenged with 1 microg/mL lipopolysaccharide (LPS) for 3 h, and then treated with each of the seven ingredients at three concentrations (1, 5 and 10 microg/mL) for 24 h. The results revealed that anemonin, aesculin and esculetin inhibited the production of IL-6, aesculin and esculetin inhibited the secretion of IL-8, anemoside B4, berberine and jatrorrhizine downregulated E-selectin expression, anemonin, berberine, jatrorrhizine and palmatine decreased the content of TXB(2). All these changes were significant. Taken together, the data suggest that all seven active ingredients of PD can effectively reduce inflammatory response, thus relieving intestinal dysfunction via multiple pathways. PMID- 19874222 TI - Anti-necrosis potential of polyphenols against snake venoms. AB - Polyphenols from the extracts of Areca catechu L. and Quercus infectoria Oliv. inhibited phospholipase A(2), proteases, hyaluronidase and L-amino acid oxidase of Naja naja kaouthia Lesson (NK) and Calloselasma rhodostoma Kuhl (CR) venoms by in vitro tests. Both extracts inhibited the hemorrhagic activity of CR venom and the dermonecrotic activity of NK venom by in vivo tests. The inhibitory activity of plant polyphenols against local tissue necrosis induced by snake venoms may be caused by inhibition of inflammatory reactions, hemorrhage, and necrosis. The result implies the therapeutic potential of plant polyphenols against necrosis in snakebite victims. PMID- 19874223 TI - Postmortem morphology and viability of human Peyer's patches in distal ileum: a technical note. AB - The intestinal mucosa contains a highly specialized immune system which plays a central role in the induction of immune reactions. In the small bowel, Gut Associated Lymphoid Tissue (GALT) is organized in lymphoid aggregates which are known as Peyer's Patches (PP). Even though human PP involvement in systemic immunity has been described, little is known about their anatomy and morphology and viability. The aim of this study was to examine PP according to their macroscopic anatomy, distribution and cell viability after death. Specimens from the distal ileum were obtained from 72 serial autopsy cases: PP were identified and, parts of them were analyzed for histological examination. Moreover, viability of recovered PP cells was assessed by the trypan blue exclusion test. Most of the PP (90%) were situated on the antimesenteric border of ileum, and the greatest density of PP occurred in the most distal segment. The number of PP varied with age, with the maximum number observed in 21- to 30-years old cadavers. Histological examination showed their remarkable architectural preservation at different post-mortem intervals (PMI), while the mucosal surface underwent autolysis. In 56% of cases PP cells were still viable, especially at PMI < 24 hours after death. These data confirm that human PP are still well preserved in a remarkable percentage of cadavers also several hours after death, and their availability may be helpful in various fields of research. PMID- 19874224 TI - Post-mortem Peyer's patches: their potential application in forensic medicine. AB - Pro-inflammatory mediators hold important functions in human body in response to infection, trauma and vascular disease. However, their action is down regulated by the release of anti-inflammatory cytokines, thus restoring a balance which reflects the immune status of a given individual. Recent studies have stressed out the importance of circulating levels of cytokines for forensic purposes even if there is a lack of studies regarding the role of post-mortem mucosa-associated lymphoid tissue. In this respect, Peyer's patches (PP), represent one of the most important immunological site of the body and the major component of the gut associated lymphoid tissue. The aim of this study was to evaluate post-mortem PP immune response in 40 serial autopsy cases of people who died from natural and traumatic death. The study examined spontaneous release of the following cytokines by fresh isolated PP cells: interleukin (IL)-12, tumor necrosis factor (TNF)-alpha, IL-10, IL-6, IL-1 beta, and IL-8. Results will show that higher levels of TNF-alpha, IL-6, IL-1 beta, and IL-8 are statistically correlated with the traumatic death group. From a forensic point of view these data demonstrate that fundamental lymphoid organs, such as PP, may have a potential in diagnosing the cause of death. PMID- 19874225 TI - A synthetic analogue of phosphatidylinositol mannoside is an efficient adjuvant. AB - We recently described the synthesis of an ether linked analogue of phosphatidylinositol dimannoside (PIM(2)ME). In the current study, PIM(2)ME was found to significantly enhance the release of the key Th1 cytokine interleukin-12 (IL-12) by dendritic cells (DCs) of naive mice in vitro, but not interleukin-10 (IL-10). Based on this result, it was hypothesized that PIM(2)ME would be an effective adjuvant for cell-mediated immune responses. Injections of PIM(2)ME alone did not lead to weight loss and did not have toxic side effects, based on biomarkers of toxicity in serum,demonstrating that the compound induced no apparent adverse side effects. Mice were vaccinated with the core antigens of the hepatitis C virus by itself or with three different adjuvants, namely PIM(2)ME, a commercial preparation of monophosphoryl lipid A (MPL) or a preparation of aluminium hydroxide gel (alum). A control group of animals received the antigen only with no adjuvants. Immune responses to the Hepatitis C viral antigens were monitored by measuring antigen-specific production of interferon-gamma (IFN gamma), the p40 subunit of interleukin-12 (IL-12) and interleukin-10 (IL-10) to assess cell-mediated immune responses. Vaccination of mice with Hepatitis C viral antigens with the adjuvant PIM(2)ME led to a significant increase in cell mediated immune responses (IFN-gamma and IL-12). Injection of Hepatitis C viral antigens in alum led to no enhancement of the cell-mediated immune response. We conclude that PIM(2)ME is an efficacious adjuvant for enhancing cell-mediated immunity, and induces no observable adverse effects. PMID- 19874226 TI - Tigecycline attenuates staphylococcal superantigen-induced T-cell proliferation and production of cytokines and chemokines. AB - The purpose of this study is to examine the in vitro modulatory effect of tigecycline on staphylococcal superantigen-induced T-cell activation and cytokines and chemokines production by human peripheral blood mononuclear cells (PBMC). Isolated human PBMC from ten healthy volunteers were stimulated by staphylococcal enterotoxin B (SEB) and Staphylococcal toxic shock syndrome toxin 1 (TSST-1) superantigens with varying concentrations of tigecycline. Cytokines IL 1 beta, IL-6, TNF-alpha, and chemokines MIP-1 alpha and MIP-1 beta concentrations were measured along with T cell proliferation. Results demonstrated that tigecycline alters cytokine production and reduces T-cell proliferation in vitro suggesting an immunomodulatory activity independent of its antimicrobial effect. PMID- 19874227 TI - Viral sequence integration into introns of chemokine receptor genes. AB - Viral DNA sequences are able to integrate into the non-coding DNA sections of the genome of human cells which have been infected, either spontaneously or experimentally. We have made a data-base search for integration events of non endogenous viruses into the introns of chemokine receptor sequences. A BLAST search of all viral DNA sequences, using the intronic sequences as "Query," returned several significant alignments. However, due to the high reiteration rate of the non-coding sequences in the human genome, it became necessary to re examine the individual alignments to verify whether the virus-flanking intronic sequence was really located in a chemokine receptor intron. We found only one unquestionable event of viral insertion of a section of a long terminal repeat of the murine leukemia virus within the first intron of the CC chemokine receptor 7 gene. Possible biological effects of such an insertion are discussed. Further experimental or clinical research could demonstrate the occurrence of other intronic viral insertions in human chemokine receptor genes. PMID- 19874228 TI - Preclinical analysis of treosulfan in combination with total body irradiation as conditioning regimen prior to bone marrow transplantation in rats. AB - Treosulfan (Treo) and total body irradiation (TBI) demonstrate a high therapeutic activity in treatment of acute leukemia and lymphoma. We investigated the combination of Treo and TBI prior to bone marrow transplantation (BMT) in rats. Female Lewis rats were treated with Treo on 3 consecutive days followed by TBI with either 5 Gy (n = 28) or 7.5 Gy (n = 48). After conditioning animals received 4 x 10E7 bone marrow cells (BC) from female Lewis rats. Additional 16 rats were transplanted with 4 x 10E7 BC and 1.5 x 10E7 spleen T-cells from female Brown Norway (BN) rats. Animals were examined daily for clinical signs and toxicity was investigated by necropsy and histology in all animals. Gastrointestinal toxicity was the dose-limiting factor of Treo in combination with TBI. The highest tolerable dose of Treo in combination with 7.5 Gy TBI was 3 x 0.5 g/kg and the highest tolerable dose of Treo in combination with 5 Gy TBI was 3 x 0.6 g/kg. Allogeneic BMT from BN donors resulted in engraftment and survival of 12 out of 16 animals. Gastrointestinal toxicity is the dose-limiting factor in the treatment with Treo and TBI. Furthermore, Treo possesses certain characteristics of a radiosensitizer. PMID- 19874229 TI - Dissociation of local anti-inflammatory effect and systemic effects of mometasone furoate in mice. AB - Mometasone furoate (MF) is a topical glucocorticoid used for atopic dermatitis, allergic rhinitis, and bronchial asthma. To elucidate the usefulness of MF, the dissociation between local anti-inflammatory effects and systemic effects of MF was compared with that of beclomethasone 17,21-dipropionate (BDP). MF was more potent than BDP in croton oil-induced ear edema tests in mice. Oral systemic effects of MF were inversely lower than that of BDP on thymolysis, plasma corticosterone lowering, and suppression of body weight gain in mice. These results indicate that MF has a higher therapeutic index and superior clinical usefulness as a topical glucocorticoid compared to BDP. PMID- 19874230 TI - The anti-ophidian properties of Anacardium occidentale bark extract. AB - Snakebites in rural areas of tropical and subtropical regions are commonly treated with medicinal plants. In this report, we have studied the ability of Anacardium occidentale bark extract to neutralize enzymatic as well as pharmacological effects induced by Vipera russelii venom. The extract neutralized the viper venom hydrolytic enzymes such as phospholipase, protease, and hyaluronidase in a dose dependent manner. These enzymes are responsible for both local effects of envenomation such as local tissue damage, inflammation and myonecrosis, and systemic effects including dysfunction of vital organs and alteration in the coagulation components. In addition, extract neutralized the pharmacological effects such as edema, hemorrhage, and myotoxic effects including lethality, induced by venom. Since, it inhibits both hydrolytic enzymes and pharmacological effects; it may be used as an alternative treatment to serum therapy and, in addition, as a rich source of potential inhibitors of hydrolytic enzymes involved in several physiopathological diseases. PMID- 19874231 TI - Different bacteria species lipopolysaccharide co-exposure with Pseudomonas exotoxin A on multiple organ injury induction. AB - The present study investigated the effect of different bacterial species lipopolysaccharide plus Pseudomonas exotoxin A (LPS/PEA) on the induction of multiple organ injury (MOI). Rats were injected with various LPS from Salmonella (SAE, SAT), E. coli (EB4, EB5), or P. aeruginosa (PAL) and PEA showed a greater mortality in the SAE/PEA and SAT/PEA groups. Histological alterations, serum enzymes, and cytokines changes were severer in the SAE/PEA group than the EB4/PEA or PAL/PEA group. EB4/PEA and PAL/PEA failed to induce MOI, even at the LPS doses increased up to 2-4- and 4-8-fold, respectively. Rats co-treated with Salmonella lipid A/PEA developed severer MOI than the E. coli lipid A/PEA. The results indicated the critical roles of MOI induction, which were related to LPS derived from appropriate bacterial species. PMID- 19874232 TI - Immunosuppressive effect of ethanol extract of Artemisia annua on specific antibody and cellular responses of mice against ovalbumin. AB - Artemisia annua has been widely used to treat autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis in traditional Chinese medicine. In this study, the ethanol extract of A. annua (EEAA) was evaluated for the immunosuppressive potentials on mice splenocyte proliferation in vitro, and the specific antibody and cellular immune responses in the ovalbumin (OVA) immunized mice. EEAA significantly suppressed concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated splenocyte proliferation in vitro in a concentration-dependent manner. EEAA also significantly suppressed Con A-, LPS- and OVA-induced splenocyte proliferation in the OVA-immunized mice in a dose dependent manner. Meanwhile, the OVA-specific serum IgG, IgG1 and IgG2b antibody levels in the OVA-immunized mice were markedly reduced by EEAA. The results suggest that EEAA could suppress the cellular and humoral response in mice. This study provided evidence to understand the therapeutic effects of A. annua for treatment of some autoimmune diseases and an immunosuppressive natural products to further researches to be developed as immunosuppressant. PMID- 19874233 TI - Reactive oxygen species (ROS): involvement in bovine follicular cysts etiopathogenesis. AB - Ovulation is compared to an acute inflammatory process during which vasoactive agents, prostanoids, leukotrienes and Reactive Oxygen Species (ROS) develop. The aim of this study was to evaluate the levels of ROS in cystic and follicular fluid, in order to establish their involvement in the etiopathogenesis of Cystic Ovarian Follicle (COF) in dairy cows. The study was conducted in 30 healthy cows (group C) and 30 cows affected by COF (group COF). The fluid of follicular cysts and of preovulatory follicles was drawn by means of ultrasound guided aspiration from the cows of both groups. The fluid obtained was analyzed by a photometric analytical system to detect ROS level. ROS concentration was statistically lower in the cystic fluid than in the follicular one (62.4 +/- 13.36 U.Carr vs. 84.89 +/- 26.99 U.Carr) (p<0.05), thus suggesting that an alteration of the cascade responsible for ROS production may be implicated in the complex etipathogenesis of COF. PMID- 19874235 TI - Ammonium perfluorooctanoate substantially alters phenotype and cytokine secretion of human monocyte-derived dendritic cells in vitro. AB - Perfluoroalkyl carboxylic acids (PFCA) are commercially used for their surfactant properties combined with chemical and thermal stability. Differentiation of peripheral monocytes to immature dendritic cells (DCs) in the presence of the PFCA, ammonium perfluorooctanoate (APFO, 200 microM) led to a considerably increased expression of CD86 and HLA-DR on immature DCs. However, these phenotypic changes were not reflected by an increased T cell-stimulatory capacity of the cells. Notably, activated, fully mature APFO-treated DCs secreted significantly less IL-12 and IL-10 than control cells. Thus, APFO at non cytotoxic concentration affects the phenotype and cytokine secretion of human DCs. PMID- 19874234 TI - The role of glucocorticoid in SIRP alpha and SHP-1 gene expression in AIHA patients. AB - The aim of this work was to evaluate the regulation of SIRP alpha, an inhibitory phagocyte receptor, and the phosphatase SHP-1 in monocytes of patients with autoimmune hemolytic anemia, and the role of dexamethasone on SIRP alpha and SHP 1 gene expression and erythrophagocytosis in vitro. SIRP alpha and SHP-1 expression was higher in monocytes from AIHA patients compared with normal, returning to normal after glucocorticoid therapy. SIRP alpha and SHP-1 mRNA expression was upregulated in healthy monocytes treated with dexamethasone compared with basal; however, the erythrophagocytic ability was not altered. Our results point to a minor role of SIRP alpha and SHP-1 in determining AIHA. PMID- 19874236 TI - Inhibitory effects of Cynodon dactylon L. on inflammation and oxidative stress in adjuvant treated rats. AB - Cynodon dactylon is one of the 10 auspicious herbs that constitute the group Dasapushpam in Ayurveda. Traditionally Cynodon dactylon L. is used against many chronic inflammatory diseases in India. The present study was carried out to evaluate the protective effect of Cynodon dactylon against rats with adjuvant- induced arthritis. Arthritis was induced by intradermal injection of complete Freund's adjuvant into the right hind paw produce inflammation of the joint. A significant increase in the levels of inflammatory mediators, myeloperoxidase, nitrite, C-reactive protein, ceruloplasmin was observed. This was associated with oxidative stress with a marked reduction in the activity of catalase, superoxide dismutase, glutathione peroxidase and the levels of glutathione, vitamins C and E and an increase in the lipid peroxidation as indicated by the higher levels of thiobarbituric acid reactive substances. Cynodon dactylon (20mg/kg/b.wt) was orally administered to arthritic rats after adjuvant injection produced a significant attenuation in the inflammatory response, oxidative stress and ameliorated the arthritic changes to near normal conditions. Hence, the results of this study clearly indicate that Cynodon dactylon extract has a promising protective role against arthritis. PMID- 19874237 TI - Cross-reaction between proteins of Larrea divaricata Cav. (jarilla) and proteins of Gram-negative bacteria. AB - Larrea divaricata is an abundant plant of northwest of Argentina used to treat different pathologies. We aimed to characterize the immunogenicity of proteins from a partially purified crude aqueous extract (JPCE) of jarilla. We evaluated the cross reaction between JPCE and whole cell-bacterial proteins (W-CBP) of Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, and Klebsiella pneumoniae using a mouse anti-JPCE serum. Protein profiles of JPCE and W-CBP were analyzed. For JPCE, 18 bands were observed in a 20-176 kDa range. Levels of IgG against JPCE and W-CBP were determined. Bacterial proteins showed a strong reaction with the anti-JPCE serum. Plant proteins could be used as immune stimulants. PMID- 19874238 TI - Induction of expression of iNOS by N-nitrosodimethylamine (NDMA) in human leukocytes. AB - The aim of this study was to assess the influence of N-nitrosodimethylamine (NDMA) on expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) by human neutrophils (PMN) and peripheral blood mononuclear cells (PBMC), and the participation of the p38 MAPK kinase in this process. Furthermore, the ability of neutrophils to release superoxide anion was determined. The influence of N nitrosodimethylamine on iNOS expression was determined in isolated PMN and PBMC cells from peripheral blood of healthy individuals. The mononuclear cells showed higher sensitivity to NDMA. Moreover, cytotoxic effect of NDMA can be influenced in some way by the impact of this xenobiotic on nitric oxide and superoxide anion release from human leukocytes. Furthermore, increased generation of these radicals by human leukocytes suggest that neutrophils and mononuclear cells that are exposed to NDMA activity can play a key role in endogenous NDMA generation. However the relationship between iNOS expression and phospho-p38 MAPK in neutrophils and mononuclear cells shows that p38 MAPK pathway participates in induction of iNOS expression in the presence of NDMA. PMID- 19874239 TI - Effect of a seashell protein Haishengsu on the immunological function of mice with Ehrlich ascites tumor. AB - This study was designed to investigate the effect of a seashell protein Haishengsu (HSS) on the immuno logical function in mice with Ehrlich ascites tumor. Ehrlich ascites tumor-bearing mice were divided into three HSS groups (25, 50 and 100 mg/kg, i.v., respectively), cyclophosphamide (10 mg i.p.) and control group. The immunological function was assessed by measuring the phagocytizing capacity of the peritoneal macrophages and neutrophils, as well as the number of spleen hemolytic plaque-forming cells. The percentage of blood T-lymphocytes was also evaluated. The number and the percentage of phagocytizing macrophages and neutrophils in the 50 and 100 mg/kg HSS groups were higher than in the control and the cyclophosphamide groups (P < 0.01). The hemolytic plaque-forming cells in the three HSS groups (10.8 +/- 1.2, 16.9 +/- 3.9 and 25.3 +/- 2.9, respectively), was greater than in the control (7.3 +/- 1.4), or the cyclophosphamide group (0.33 +/- 0.4) (all P < 0.01). In all HSS groups, the percentage of blood T3, T4 and T8 was higher than in the cyclophosphamide and the control group (all P < 0.01). We conclude that HSS has significant immune-modulating effect in mice with Ehrlich ascites tumor. PMID- 19874240 TI - Mechanisms of diabetes mellitus induced with FK506 in SD rats models. AB - BACKGROUND: Tacrolimus causes post-transplant diabetes mellitus, however the pathogenetic mechanisms remain controversial. In this study we probed into the mechanisms of tacrolimus-induced diabetes mellitus in rats. METHODS: Glucose levels were determined on whole blood samples using a glucose oxidase method. Levels of serum insulin and C-peptide were measured with ELISA. Histological damage of ultra-structure and apoptosis of beta cells of the pancreas were assayed with electric microscope and tunnel methods respectively.--Ultra structure were assayed with electric microscope and apoptosis of beta cells of the pancreas were assayed with tunnel methods. Immunohistochemistry was utilized to detect the sum of insulin receptors of hepatic cells. RESULTS: Compared to control group, insulin and C peptide levels in serum decreased in rats of diabetes mellitus models induced with FK506(P<0.05). Compared to the control group, the sum of apoptosis body in pancreatic islets increased in rats of diabetes mellitus models induced with FK506 (P<0.05). Compared to the control group, electron microscopy showed cytoplasm swelling and vacuolization, and marked decrease or absence of dense-core secretory granules in beta cells in rats with diabetes mellitus induced with FK506.Compared to the control group, expression of insulin receptor of hepatic cell decreased in rats of diabetes mellitus models induced with FK506 (P<0.05). CONCLUSION: Pathogenetic mechanisms of rats of diabetes mellitus models induced with FK506 including reduction of secretion of insulin in beta cells of pancreatic islets, damages of ultra structure of beta cells of pancreatic islets, increasing of apoptosis of beta cells of pancreatic islets and decreasing of expression of insulin receptors in hepatic cells. PMID- 19874241 TI - Effects of antibiotics on biochemical parameters, leukocytes and reactive oxygen species (ROS) in bitches after ovariectomy. AB - It is well known that following surgical procedures, a variety of patho physiological alterations occurs in the host, such as changes in haemodynamic, endocrine and immune functions, as well as increase in Reactive Oxygen Species (ROS). Antibiotic administration, a common practice used in surgery, affects immune functions and ROS generation. Our study was aimed to investigate the effect of five different antibiotic regimens: amoxicillin, benzylpenicillin/dihydrostreptomycin, sulfametazine/sulfamerazine/ sulfathiazole, enrofloxacin, lincomycin/spectinomycin, administered twice (2 hours before skin incision and 6 hours after the end of the surgical suture), on biochemical parameters, leukocytes and ROS concentrations, in bitches undergoing open laparotomic ovariectomy. All treated bitches recovered from surgery without developing either systemic dysfunctions, or infections at the surgical site. Mean healing time was 7 +/- 3 days. An increase in white blood cell count, in differential leukocyte count and in ROS concentrations occurred 24 hours after the end of surgery, followed by a gradual decrease to basal values within the fourth day after surgery. The biochemical parameters remained quite constant throughout the study. In conclusion, our results show that the above antibiotic regimens, administered only twice, are efficient in inducing an uneventful recovery after laparotomic ovariectomy and preventing the development of infections in the bitch. PMID- 19874242 TI - Effect of Brazilian propolis on sneezing and nasal rubbing in experimental allergic rhinitis of mice. AB - We studied the effect of Brazilian propolis on sneezing and nasal rubbing in experimental allergic rhinitis of mice. A single administration of propolis caused no significant effect on both antigen-induced nasal rubbing and sneezing at a dose of 1000 mg/kg, but a significant inhibition was observed after repeated administration for 2 weeks at this dose. Propolis caused no significant inhibitory effect on the production of total IgE level after repeated administration of 1000 mg/kg. The drug also caused no significant inhibition of histamine-induced nasal rubbing and sneezing at a dose of 1000 mg/kg. On the other hand, propolis significantly inhibited histamine release from rat mast cells induced by antigen and compound 48/80 at a concentration of more than 10 microg/ml. These results clearly demonstrated that propolis may be effective in the relief of symptoms of allergic rhinitis through inhibition of histamine release. PMID- 19874243 TI - The paradoxical immuno-response of adenosine triphosphate effects. AB - The actual research on the paradoxical effects of ATP to obtain to optimal conditions of the immune response against certain pathologies. The ATP Paradox, after its interaction with iron or aluminum, which have shown important effects on carcinogenesis, suggests its implication in pathological systems in which overcalcification may play a role. PMID- 19874244 TI - Anti-complementary effect of polysaccharide B3-PS1 in Herba Scutellariae Barbatae (Scutellaria barbata). AB - The polysaccharide B3-PS1 was extracted and purified from Herba Scutellariae Barbatae (Scutellaria barbata D. Don), through bioactivity-guided fractionation. Average molecular weight of B3-PS1 was about 1,700,000 Da with a composition of Gal, Glc, Man and Ara in the ratio of 4.3:1.6:1.1:1.0, and trace of Rha, Fuc and Xyl. Preliminary data showed that 1) B3-PS1 inhibited complement activation of the classic pathway with CH(50) value of 0.12 +/- 0.02 mg/ml and of the alternative pathways with AP(50) value of 0.36 +/- 0.05 mg/ml; 2) B3-PS1 interacts with C1q, C1r, C1s, C2, C3, C4, C5 and C9 through a hemolytic assay. These results strongly suggested that B3-PS1 could be a potential candidate in treating those complement-associated diseases such as rheumatoid arthritis, Alzheimer's disease, and Adult Respiratory Distress Syndrome (ARDS). PMID- 19874245 TI - Hepatic veno-occlusive disease during chemotherapy for nephroblastoma: successful and safe treatment with defibrotide. Report of a clinical case. AB - Here we report a case of administration of defibrotide in an 11 months old infant with hepatic veno-occlusive disease during chemotherapy for nephroblastoma. He presented with abdominal distension, a weight gain of 15%, ascites, hepatomegaly with right upper quadrant pain, thrombocytopenia and hypertransaminasemia. Despite therapy, his clinical conditions aggravated, and, therefore intravenous administration of defibrotide on a compassionate-use basis was started. The dosage was 15 mg/kg/day in 4 divided doses, which was increased gradually (in 3 days) to 40 mg/kg/day in 4 divided doses. Defibrotide proved safe and effective in resolving clinical symptoms and normalizing serological findings in the syndrome. PMID- 19874246 TI - The epidemiology, economic burden, and pharmacological treatment of chronic low back pain in France, Germany, Italy, Spain and the UK: a literature-based review. AB - OBJECTIVE: This study's objective was to review the literature on the epidemiological and economic burden and treatment of chronic low back pain (CLBP) in France, Germany, Italy, Spain and the UK. METHODS: A literature search was conducted for 1997 - 2007, focusing on CLBP burden and treatment in the countries of interest. RESULTS: The literature search yielded 1552 articles; 23 sources were included in this review. General population prevalence estimates for CLBP were available for two countries: 5.91% (Italy) and 6.3 - 11.1% (UK). Resource utilization estimates were available for Germany, Italy, Spain and the UK. Patients visited general practitioners and osteopaths. Annual direct costs of low back pain were available only for Germany: > euro 7000 per person. Work absenteeism accounted for 75% of the total per-patient cost of low back pain in Germany. The five identified treatment guidelines recommended a multimodal approach. Recommended pharmacotherapies included NSAIDs, muscle relaxants, analgesics and anesthetics, and opioids. CONCLUSIONS: Prevalence estimates varied, possibly owing to differences in diagnostic criteria and populations studied. Little is known about CLBP's economic burden. Treatment guidelines recommended multimodal treatment. PMID- 19874247 TI - Pharmacotherapy of postpartum depression. AB - BACKGROUND: The prevalence and recurrence rates of postpartum depression (PPD) are 13 and 25%, respectively. Despite its detrimental impact on the health of the mother-infant dyad, there is a paucity of data in the literature regarding the efficacy of pharmacological treatment of PPD. OBJECTIVES: i) To review the literature on the use of antidepressants and hormonal supplements for the prevention and the treatment of PPD; ii) to give the authors' opinion on the current status of the pharmacological treatment of PPD; and iii) to discuss developments that are likely to be important in the future. METHODS: An electronic search was performed by using PubMed, Medline, and PsychINFO. Inclusion criteria were: i) empirical articles in peer-reviewed English-language journals; ii) well-validated measures of depression; and iii) a uniform scoring system for depression among the sample. RESULTS/CONCLUSION: The electronic search yielded a total of 19 articles (12 on treatment and 7 on prevention of PPD) with the following study designs: eight randomized clinical trials (six using placebo control and two using active control groups), and 11 open-label studies. The selection of the specific antidepressant for a woman with PPD should derive from a personalized risk-benefit analysis. PMID- 19874248 TI - Luteinizing hormone-releasing hormone (LHRH) agonists in the treatment of breast cancer. AB - This article reviews the use of luteinizing-hormone-releasing hormone (LHRH) agonists in pre- or perimenopausal women with hormone-receptor-positive breast cancer. Estimates of efficacy from systematic reviews, based on several randomized trials, are provided. These show that LHRH agonists can reduce the risk of recurrence and death, and can be an alternative to chemotherapy, particularly for women who would like to avoid early menopause. The benefits can be seen 10 or 15 years later. The main side effects - hot flashes and reduction in bone density - often recede once treatment stops. Ongoing research will provide information about LHRH agonists when used with modern chemotherapy regimens and aromatase inhibitors. PMID- 19874249 TI - Pharmacotherapy of intraocular pressure: part I. Parasympathomimetic, sympathomimetic and sympatholytics. AB - Elevated intraocular pressure (IOP) has been recognized as the major risk factor for the development of glaucoma and a wide range of options are now available to reduce it: medical treatment, laser, filtering, or cyclodestructive surgery (alone or in combination). All these modalities act by decreasing eye pressure and, thereby, protecting the optic nerve head from a mechanic direct and/or vascular indirect insult. Topical medical therapy represents the first-choice treatment and, in most cases, it effectively controls IOP, avoiding the occurrence of further optic nerve damage. All medications lower IOP in two main ways: decreasing the production of aqueous humour or by increasing its outflow from the eye. Consequently, antiglaucoma drugs either suppress aqueous humour formation (beta-adrenergic antagonists, carbonic anhydrase inhibitors, and alpha 2-adrenergic agonists) or raise aqueous humour outflow throughout the conventional (e.g., pilocarpine) or uveoscleral (prostaglandin FP receptor agonists, and prostamides) route. In addition, fixed and unfixed combinations of antiglaucoma compounds have also been available for patients requiring more than one type of medication. This review, which is part one of two (please see Expert Opinion on Pharmacotherapy 10 (17)) briefly considers the characteristics of sympathomimetic, sympatholytics and parasympathomimetic commonly employed in the medical treatment of glaucoma, mainly the primary open-angle form, focusing the discussion on the clinical evidence supporting the use of these three classes of compound. PMID- 19874250 TI - Dexmethylphenidate for attention deficit hyperactivity disorder. AB - BACKGROUND: Dexmethylphenidate is a single-isomer stimulant medication approved for the treatment of attention deficit hyperactivity disorder (ADHD). Single isomer drugs have the potential for decreased undesired effects and improved therapeutic efficacy. Stimulant medications have been the mainstay treatments for ADHD for fifty years, and ability to reduce their adverse effects would be useful in promoting patient compliance with treatment. OBJECTIVE: To review the literature on the safety and efficacy of dexmethylphenidate. METHODS: MedLine, PubMed search of dexmethylphenidate research. RESULTS/CONCLUSIONS: Dexmethylphenidate is a safe and effective treatment for ADHD. Its overall safety and tolerability profile is similar to other members of the psychostimulant class. PMID- 19874251 TI - Mecamylamine - a nicotinic acetylcholine receptor antagonist with potential for the treatment of neuropsychiatric disorders. AB - Mecamylamine (Inversine), the first orally available antihypertensive agent launched in the 1950s, is rarely used today for hypertension because of its widespread ganglionic side effects at antihypertensive doses (25 - 90 mg/day). However, more recent clinical studies suggest that mecamylamine is effective at much lower doses for blocking the central and peripheral effects of nicotine. Pharmacologically, mecamylamine has been well characterized as a nonselective and noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs). Because mecamylamine easily crosses the blood - brain barrier at relatively low doses (2.5 - 10 mg), it has been used by several research groups over the past two decades investigating the role of central nAChRs in the etiology and treatment of various neuropsychiatric disorders, including addiction disorders, Tourette's syndrome, schizophrenia and various cognitive and mood disorders. Two independent Phase II clinical trials recently confirmed mecamylamine's hypothesized antidepressant activity and suggest that it may be effective as an augmentation pharmacotherapy for SSRI treatment resistant major depression. These areas of investigation for mecamylamine are reviewed and recommendations for future research directions are proposed. PMID- 19874252 TI - Terbinafine: a pharmacological and clinical review. AB - Terbinafine (TRB) is an allylamine antifungal agent that has been available for more than a decade. It is now used for the treatment of dermatophytic infections and onychomycosis. Despite several studies having demonstrated the efficacy of terbinafine against nondermatophytic infections including azole-resistant candidiasis, invasive aspergillosis, disseminated fusariosis and scedosporiosis, the role of TRB in the management of these infections remains greatly underappreciated. A brief review of pharmacodynamic, pharmacokinetic, in vitro and in vivo data and published case reports provides insight into the use of terbinafine as a potential adjunct in combination with azoles, polyenes or echinocandins in the management of severe drug-resistant or refractory mycoses. Despite the lack of intrinsic fungicidal activity against several nondermatophytes, when used in combination, particularly with azoles, TRB has demonstrated good antifungal efficacy that could be exploited in clinical practice. As comprehensive human clinical studies are not feasible with the rare occurence of these mycoses, experiments using animal models are essential to evaluate the in vivo efficacy of drug combinations. In summary, terbinafine has established itself as a drug of choice for dermatophytic infections; it must be considered in combination with other antifungal agents for the management of nondermatophytic refractory or resistant yeast/mold infections as well. PMID- 19874253 TI - Vildagliptin in clinical practice: a review of literature. AB - Vildagliptin is the second member of the DPP-IV inhibitor class of drugs licensed for the treatment of type 2 diabetes mellitus (T2DM). The novel action of these drugs has promoted a new outlook in the pathobiology of T2DM. This review undertakes to examine the clinical studies published to date, with the aim of evaluating the position of vildagliptin among the drugs that are now available to treat this common dysmetabolic state. PMID- 19874254 TI - Bimatoprost - a review. AB - Bimatoprost is a synthetic prostamide analog that is efficacious in the treatment of open-angle glaucoma, ocular hypertension and other forms of glaucoma. It reduces intraocular pressure (IOP) by increasing uveoscleral and trabecular outflow. When used as a 0.03% topical preparation once daily, it demonstrates sustained lowering of IOP of 7 - 8 mmHg over a 24-h period. The drug has been found to be more effective than timolol. In some studies it has shown greater ability to lower IOP when compared with other prostaglandin analogs; whereas in others all three clinically used prostaglandin analogs were found to be equally effective. It shows good IOP reduction when used in combination with other glaucoma medications. A common side effect includes mild conjunctival hyperemia, which is generally reversible. Other side effects include periorbital pigmentation, discomfort, ocular surface hyperemia and skin changes. Pharmacoeconomic data indicate that bimatoprost is cost effective in the treatment of open-angle glaucoma. PMID- 19874255 TI - Current status of thoracic endografting and its adjunctive pharmacology. AB - BACKGROUND: Thoracic endovascular aortic repair is a promising treatment modality. The advantages in the short term include shorter hospital stay, avoidance of lengthy invasive procedures, and decreased anesthesia time. It has made possible the treatment of elderly patients with coexisting comorbidities who otherwise would be difficult candidates for open surgery. OBJECTIVE: Although the technical aspects of thoracic endovascular procedures have been described in the literature, the adjunct pharmacology has not been discussed. The aim of this study is therefore to review the clinical pharmacology necessary for procedural details in repair of patients with aortic aneurysms and aortic dissection. METHODS: A literature search was performed using PUBMED by combining relevant Medical Subject Heading key words. The query was subsequently limited to English language, and involving "human". The articles were assessed for their validity, importance, and applicability. The publications were analyzed and clinically important data were collected and incorporated. RESULTS/CONCLUSION: Thoracic endovascular aortic repair is a complex procedure on a morbid cohort of patients with aortic pathologies. The pharmacotherapy is a crucial component of the procedure: It is aimed at facilitating the endovascular procedure and improving outcomes. PMID- 19874256 TI - Therapeutic effects of low-level laser on lateral epicondylitis from differential interventions of Chinese-Western medicine: systematic review. AB - BACKGROUND: Low-level laser therapy (LLLT) is a conservative treatment for lateral epicondylitis (LE), but it is also an alternative intervention between the very different approaches of Chinese and Western medicine. OBJECTIVE: The purpose of this study was to systematically review and meta-analyze the therapeutic effects of LLLT on LE. METHODS: We searched several electronic databases, including Medline, PubMed, and CINAHL, and explored studies that were randomized controlled trials on the therapeutic effects of LLLT on LE from 1990 to February 2009. These studies were systematically reviewed for the difference in therapeutic effects among various LLLTs on acupuncture points and on tender and myofascial trigger points (MTrPs). The reviewed therapeutic effects included pain, grip strength, range of motion (ROM), and weight tests, and were compared by meta-analysis. RESULTS: We selected ten articles, and in seven of them the irradiation was conducted on tender points or MTrPs in the experimental groups. In two other articles, the irradiation was conducted on acupuncture points, and the last one was conducted on both kinds of points. Only three articles provided sufficient data for meta-analysis. The results revealed that applying LLLT on tender points or MTrPs is an effective means to improve the effect size (ES) of pain release after treatment (pooled ES: 0.71, 95% CI: 0.82- approximately 0.60) and follow-up (pooled ES: 1.05, 95% CI: 1.16- approximately 0.94). LLLT application was also able to increase the grip force, ROM, and weight test (p < 0.05). CONCLUSIONS: We suggest that using LLLT on tender points or MTrPs of LE could effectively improve therapeutic effects. PMID- 19874257 TI - Antifungal agents, WO2009025733. AB - BACKGROUND: The incidence and prevalence of serious mycoses continues to be a public health problem. These infections are an important cause of morbidity and mortality, especially in immunocompromised patients. The present patent deals with isolation and characterization of a 'pure' mixture of two novel isoxazolidinone-containing natural products from two new fungal strains. They have the partial structure of secalonic acid and show very good antifungal activity in mammals and plants and also synergism with other active ingredients. OBJECTIVE: To analyze the activity of the isoxazolidinone-containing compounds in the present patent. METHODS: To review the discovery and development of antifungal compounds in general and secalonic acid related compounds in particular. CONCLUSION: The research of Parish and collaborators at Merck and Co. has isolated novel antifungal compounds with a new mode of action. These molecules may be considered potential antifungal leads for further clinical study. PMID- 19874261 TI - GLUT1 as a therapeutic target in hepatocellular carcinoma. AB - Primary hepatocellular carcinoma (HCC) is one of the most fatal cancers in humans with rising incidence in many regions around the world. Currently, no satisfactory curative pharmacological treatment is available, and the outcome is mostly poor. Recently, we have shown that the glucose transporter GLUT1 is increased in a subset of patients with HCC and functionally affects tumorigenicity. GLUT1 is a rate-limiting transporter for glucose uptake, and its expression correlates with anaerobic glycolysis. This phenomenon is also known as the Warburg effect and recently became of great interest, since it affects not only glucose uptake and utilization but also has an influence on tumorigenic features like metastasis, chemoresistance and escape from immune surveillance. Consistent with this, RNA-interference-mediated inhibition of GLUT1 expression in HCC cells resulted in reduced tumorigenicity. Together, these findings indicate that GLUT1 is a novel and attractive therapeutic target for HCC. This review summarizes our current knowledge on the expression and function of GLUT1 in HCC, available drugs/strategies to inhibit GLUT1 expression or function, and potential side effects of such therapeutic strategies. PMID- 19874262 TI - Acid ceramidase upregulation in prostate cancer: role in tumor development and implications for therapy. AB - Bioactive sphingolipids, such as ceramide, sphingosine and sphingosine-1 phosphate are known bio-effector molecules which play important roles in various aspects of cancer biology including cell proliferation, growth arrest, apoptosis, metastasis, senescence and inflammation. Therefore, enzymes involved in ceramide metabolism are gaining recognition as being critical regulators of cancer cell growth and/or survival. We previously observed that the ceramide metabolizing enzyme, acid ceramidase (AC) is upregulated in tumor tissues. Studies have now concluded that this creates a dysfunctional ceramide pathway, which is responsible for tumor progression and resistance to chemotherapy and radiation. This suggests that development of small-molecule drugs that inhibit AC enzyme activity is a promising approach for improving standard cancer therapy and patient's clinical outcomes. PMID- 19874264 TI - Understanding the basis for the association of apoE4 with Alzheimer's disease: opening the door for therapeutic approaches. AB - Apolipoprotein E4 (apoE4) is the major genetic risk factor for Alzheimer's disease (AD) by an as yet to be defined mechanism. Since the structure or biophysical properties of a protein directly determines function, our approach to addressing mechanism is structure:function based. Domain interaction a structural property of apoE4 that distinguishes it from apoE3 is predicted to contribute to the association of apoE4 with AD. We developed a mouse model, the Arg-61 apoE model, which is specific for domain interaction. These mice display synaptic, functional, and cognitive deficits, demonstrating domain interaction is the causative factor. We present evidence that domain interaction results in stressed astrocytes that are dysfunctional and propose that dysfunctional astrocytes are an early player in apoE4-associated AD and that domain interaction is a potential therapeutic target. PMID- 19874263 TI - Modulation and detection of tau aggregation with small-molecule ligands. AB - Recent results from high-throughput and other screening approaches reveal that small molecules can directly interact with recombinant full-length tau monomers and fibrillar tau aggregates in three distinct modes. First, in the high concentration regime (>10 micromolar), certain anionic molecules such as Congo red efficiently promote tau filament formation through a nucleation-elongation mechanism involving a dimeric nucleus and monomer-mediated elongation. These compounds are useful for modeling tau aggregation in vitro and in biological models. Second, in the low concentration regime (<1 micromolar), other ligands, including cyanine dyes, display aggregation antagonist activity. Compounds that can prevent or reverse fibrillization are candidate modifiers of disease pathology. Finally, certain compounds bind mature tau fibrils with varying affinities at multiple binding sites without modulating the aggregation reaction. For some ligands, >10-fold selectivity for tau aggregates relative to filaments composed of beta-amyloid or alpha-synuclein can be demonstrated at the level of binding affinity. Together these observations suggest that small-molecules have utility for interrogating the tau aggregation pathway, for inhibiting neuritic lesion formation, and for selective pre-mortem detection of neurofibrillary lesions through whole brain imaging. PMID- 19874265 TI - A neurotrophic rationale for the therapy of neurodegenerative disorders. AB - The concept and rationale for neuroprotection are presented. Several examples of small molecule neurotrophic agents with favourable drug-like and pharmacological properties are shown. Compound efficacy in acute neurodegenerative models (optic nerve axotomy) and chronic neurodegenerative models (glaucoma, age-associated cognitive impairment, Alzheimer's Disease) are evaluated and discussed. Targeting neurotrophin receptors with ligands that activate survival pathways or inhibit death pathways is an alternative worth pursuing. PMID- 19874266 TI - Suppression of glial HO-1 activity as a potential neurotherapeutic intervention in AD. AB - The mechanisms responsible for oxidative damage, pathological brain iron deposition and mitochondrial insufficiency in Alzheimer disease (AD) remain enigmatic. Heme oxygenase-1 (HO-1) is a 32 kDa stress protein that catabolizes heme to biliverdin, free iron and carbon monoxide. The HO-1 gene is exquisitely sensitive to oxidative stress and is induced in brain and other tissues in various models of disease and trauma. Our laboratory demonstrated that 1) HO-1 protein is significantly over-expressed in AD-affected temporal cortex and hippocampus relative to neurohistologically-normal control preparations, 2) in cultured astrocytes, HO-1 up-regulation by transient transfection of the human ho 1 gene, or stimulation of endogenous HO-1 expression by exposure to beta-amyloid, TNFalpha or IL-1beta, promotes intracellular oxidative stress, opening of the mitochondrial permeability transition pore and accumulation of non-transferrin iron in the mitochondrial compartment, and 3) the glial iron sequestration renders co-cultured neuron-like PC12 cells prone to oxidative injury. Induction of the astroglial ho-1 gene may constitute a 'common pathway' leading to pathological brain iron deposition, intracellular oxidative damage and bioenergetic failure in AD and other human CNS disorders. HYPOTHESIS: Targeted suppression of glial HO-1 hyperactivity may prove to be a rational and effective neurotherapeutic intervention in AD and related neurodegenerative disorders. To begin testing this hypothesis, studies have been initiated to determine whether systemic administration of a novel, selective and brain-permeable inhibitor of HO 1 activity ameliorates cognitive dysfunction and neuropathology in a transgenic mouse model of AD. PMID- 19874267 TI - A PPARdelta agonist reduces amyloid burden and brain inflammation in a transgenic mouse model of Alzheimer's disease. AB - Agonists of the peroxisome proliferator activated receptor gamma (PPARgamma) have been shown to reduce inflammatory responses in several animal models of neurological diseases and conditions and to reduce amyloid burden in transgenic mice expressing mutant forms of human amyloid precursor protein. However, the effects of activating the related receptor PPARdelta (PPARdelta), which is expressed at higher levels in the brain than PPARgamma, on inflammation and amyloid burden have not been explored. In this study we tested the effects of the selective PPARdelta agonist GW742 in 5xFAD mice which harbor 3 mutations in amyloid precursor protein and 2 mutations in presenilin 1, develop plaques by 5-6 weeks of age, and show robust inflammation and neuronal damage. Oral delivery of GW742 significantly reduced amyloid plaque burden in the subiculum region of 3 month old male and female 5xFAD mice. GW742 also significantly reduced astrocyte activation, suggesting anti-inflammatory effects on glia cells. The changes in plaque burden were accompanied by increased expression of the amyloid degrading enzymes neprilysin and insulin degrading enzyme, while in transfected HEK293 cells, GW742 activated a neprilysin promoter driving luciferase expression. These results suggest that, as found for some PPARgamma agonists, PPARdelta agonists can also reduce amyloid burden likely to be mediated by effects on amyloid clearance. PMID- 19874268 TI - Lysosomal modulatory drugs for a broad strategy against protein accumulation disorders. AB - Protein accumulation leads to CNS effects in Alzheimer's disease, frontotemporal dementia, and other age-related disorders. Common mechanisms may contribute to the progressive pathology in the different protein accumulation disorders, and synergistic toxicity between dissimilar protein structures may also be involved. Among several avenues being pursued to reduce proteins prone to oligomerization and/or aggregation, a lysosomal avenue has been described that regulates the lysosomal system's broad clearance capability. Lysosomes are the primary site for protein clearance, to remove old and misfolded proteins and maintain cellular homeostasis. Small-molecule lysosomal modulators trigger a feedback response in vitro and in vivo, resulting in marked up-regulation of cathepsins and other lysosomal enzymes without any indications of synaptic pathology, behavioral abnormalities, or major organ malfunctions. For the characterization and screening of lysosomal modulatory drugs, the hippocampal slice model of protein accumulation has proved very useful. The model exhibits experimentally-induced phosphorylated tau species, paired helical filament deposits, ubiquitinated inclusions, and protein oligomers, thus providing a valuable tool to study the associated sequelae underlying progressive cellular and synaptic compromise. In the absence of modulatory drugs, the protein accumulation events lead to microtubule destabilization, transport failure, and synaptic decline. When lysosomal modulators are administered to slices with pre-existing deposits, protein accumulations are reduced causing normalization of tau chemistry, restoration of tubulin structures and tubulin-binding proteins, and recovery of synaptic composition. Thus, positive modulators of the lysosomal system represent first-in-class drugs, providing a suitable strategy to enhance protein clearance, promote synaptic health, and slow the progression of proteinopathies. PMID- 19874269 TI - Tau-focused immunotherapy for Alzheimer's disease and related tauopathies. AB - Immunotherapies targeting the amyloid-beta (Abeta) peptide in Alzheimer's disease (AD) have consistently been effective in mouse studies and shown promise in clinical trials, although some setbacks have occurred. First, encephalitis was observed in a small subset of patients. More recent autopsy data from a few subjects suggests that clearance of Abeta plaques may not halt cognitive deterioration once impairments are evident, emphasizing the need for other more effective approaches at that stage of the disease. Another important target in AD is the neurofibrillary tangles and its precursors, composed primarily of hyperphosphorylated tau proteins, which correlate well with the degree of dementia. As Abeta and tau pathologies are likely synergistic, targeting both together may be more effective, and perhaps essential as early diagnosis prior to cognitive decline is currently unavailable. Also, Abeta immunotherapy results in a very limited indirect clearance of tau aggregates, showing the importance of developing a separate therapy that directly targets pathological tau. Our findings in two tangle mouse models indicate that active immunization targeting an AD phospho-tau epitope reduces aggregated tau in the brain and prevents/slows progression of the tangle-related behavioral phenotype, including cognitive impairment. These antibodies enter the brain and bind to pathological tau within neurons although the therapeutic effect may at least in part be due to clearance of extracellular tau that may have biological effects. We are currently clarifying the mechanism of these promising findings, determining its epitope specificity as well as assessing the feasibility of this approach for clinical trials. PMID- 19874270 TI - O-GlcNAc modification and the tauopathies: insights from chemical biology. AB - The aggregation of the microtubule-associated protein tau into paired-helical filaments is the defining characteristic of the tauopathies. It has become apparent that the hyperphosphorylation of tau likely plays a role in the aggregation process and thus strategies to reduce tau phosphorylation are generating wide interest. The O-GlcNAc posttranslational modification of tau has been shown to be reciprocal to its phosphorylation; increasing O-GlcNAc leads to reductions in tau phosphorylation. In this mini-review, we highlight the use of chemical compounds as a means of understanding the reciprocal nature of tau phosphorylation and tau O-GlcNAcylation and highlight some recent progress in this area. PMID- 19874271 TI - Addressing Alzheimer's disease tangles: from NAP to AL-108. AB - AL-108 is the intranasal formulation of NAP (a peptide of eight amino acids, NAPVSIPQ). Phase IIa clinical results have recently shown that AL-108 has a positive impact on memory function in patients with amnestic mild cognitive impairment (aMCI), a precursor to Alzheimer's disease (AD). The clinical development of AL-108 has been based on extensive studies showing pre-clinical efficacy for NAP. NAP has demonstrated potent neuroprotective activity in vitro and in vivo. Its mechanism of action is thought to center on the modulation of microtubule stability in the face of outside damage. Such an effect on structures of such central importance in a broad range of cellular functions is thought to explain NAP's activity in wide ranging models of cellular damage and neurodegeneration. The following article reviews NAP's discovery and pharmacological characterization that has led to clinical development of a novel tangle-directed drug candidate. PMID- 19874272 TI - Effect of IPP5, a novel inhibitor of PP1, on apoptosis and the underlying mechanisms involved. AB - Genes encoding apoptosis-inducing proteins are postulated to be candidate tumour suppressors. The identification of such proteins may benefit the early diagnosis and therapy of tumours. In the present study, we characterized the function of a novel human BMSC (bone marrow stromal cell)-derived protein {IPP5 [inhibitor-5 of PP1 (protein phosphatase 1)]} by large-scale random sequencing of a human BMSC cDNA library. hIPP5 (human IPP5) cDNA encodes a protein of 116 amino acid residues, which shares high homology with human PPI-1 (inhibitor-1 of PP1). The effect of IPP5 on apoptosis and the underlying molecular mechanisms were investigated by overexpression of IPP5 in HeLa cells, a human cervical carcinoma cell line. Our results showed that overexpression of active mutant IPP5 inhibited anchorage-dependent growth and induced apoptosis in HeLa cells, which may be attributed to the up-regulation of p21(waf/cip1) (a 21 kDa cell-cycle regulatory protein), p53 and Bcl-2-antagonist/killer, and down-regulation of Bcl-2 and Bcl X(L). We also showed that the expression of active mutant IPP5 in HeLa cells was further enhanced on TNF (tumour necrosis factor) treatment and overexpression of active mutant IPP5 sensitized HeLa cells to TNF-induced JNK (c-Jun N-terminal kinase) and p38 activation as well as TNF-mediated apoptosis. Thus overexpression of active mutant IPP5 may increase cell susceptibility to TNF-induced apoptosis by the activation of p38 and JNK pathways. In addition, IPP5 active mutant could interact with PP1alpha as demonstrated by the co-precipitation assay. PMID- 19874273 TI - Early-life nutrition influences thymic growth in male mice that may be related to the regulation of longevity. AB - Nutrition and growth rate during early life can influence later health and lifespan. We have demonstrated previously that low birthweight, resulting from maternal protein restriction during pregnancy followed by catch-up growth in rodents, was associated with shortened lifespan, whereas protein restriction and slow growth during lactation increased lifespan. The underlying mechanisms by which these differences arise are unknown. In the present study, we report that maternal protein restriction in mice influences thymic growth in early adult life. Offspring of dams fed a low-protein diet during lactation (PLP offspring) had significant thymic growth from 21 days to 12 weeks of age, whereas this was not observed in control mice or offspring of dams fed a low-protein diet during pregnancy (recuperated offspring). PCNA (proliferating-cell nuclear antigen) and SIRT1 (silent information regulator 1) protein levels at 21 days of age were significantly higher in the thymus from both PLP mice (P<0.001 and P<0.05 respectively) and recuperated mice (P<0.001 and P<0.01 respectively) compared with controls. At 12 weeks, PLP mice maintained a higher SIRT1 level, whereas PCNA was decreased in the thymus from recuperated offspring. This suggests that mitotic activity was initially enhanced in the thymus from both PLP and recuperated offspring, but remained sustained into adulthood only in PLP mice. The differential mitotic activity in the thymus from PLP and recuperated mice appeared to be influenced by changes in sex hormone concentrations and the expression of p53, p16, the androgen receptor, IL-7 (interleukin-7) and the IL-7 receptor. In conclusion, differential thymic growth may contribute to the regulation of longevity by maternal diet. PMID- 19874274 TI - Chicken ileal bile-acid-binding protein: a promising target of investigation to understand binding co-operativity across the protein family. AB - Protein-bile acid interactions are crucial microscopic events at the basis of both physiological and pathological biochemical pathways. BABPs (bile-acid binding proteins) are intracellular transporters able to bind ligands with different stoichiometry, selectivity and co-operativity. The molecular determinants and energetics of interaction are the observables that connect the microscopic to the macroscopic frameworks. The present paper addresses the study and proposes a mechanism for the multi-site interaction of bile acids with chicken I-BABP (ileal BABP) with the aim of elucidating the determinants of ligand binding in comparison with homologous proteins from different species and tissues. A thermodynamic binding model describing two independent consecutive binding sites is derived from isothermal titration calorimetry experiments and validated on the basis of both protein-observed and ligand-observed NMR titration data. It emerges that a singly bound protein is relatively abundant at low ligand/protein molar ratios assessing the absence of strong co-operativity. Both the measured energetics of binding and the distributed protein chemical-shift perturbations are in agreement with a first binding event triggering a global structural rearrangement. The enthalpic and entropic contributions associated with binding of the first ligand indicate that the interaction increases stability and order of the bound protein. The results described in the present study point to the presence of a protein scaffold which is able to establish long range communication networks, but does not manifest positive-binding co operativity, as observed for the human protein. We consider chicken I-BABP a suitable model to address the molecular basis for a gain-of-function on going from non-mammalian to mammalian species. PMID- 19874275 TI - Apoptosis in the myocardium of the adult dromedary camel: ultrastructural characterization. AB - Apoptosis is a highly regulated mode of cell death that occurs in the absence of inflammation. Light microscopic (LM) examination of the myocardium of apparently healthy camel did not reveal evidence of apoptosis in any samples; however, evidence of apoptosis was apparent by transmission electron microscopy (TEM). The most common apoptotic features observed by TEM included (1) an intact sarcolemma with some bleb formation; (2) nuclear chromatin condensation and margination with nucleolar disruption; (3) mitochondrial swelling and disorganization, accompanied by degeneration or hypercondensation of cristae; and (4) an intercalated disc region with a higher-than-normal mitochondrion/myofibril ratio, or surrounded from both sides by asymmetrically contracted sarcomeres. Apoptotic alterations were also noted among the endothelial cells lining the microvasculature of the myocardium. These alterations included (1) marked nuclear chromatin condensation and margination; (2) villous blebs on the adluminal plasmalemma, which projected into the lumen; (3) cytoplasmic vacuolation; (4) presence of intraluminal membrane-bounded vesicles; and (5) occasional pericapillary edema and accumulations of cellular debris. The results of this study indicate that myocardial apoptosis can occur in apparently healthy camels, in the absence of a clear-cut etiology. PMID- 19874276 TI - Morphometric analysis of the canal system of cortical bone: An experimental study in the rabbit femur carried out with standard histology and micro-CT. AB - The osteonal pattern of cortical bone is gradually built around the intracortical vessels by the progression of the cutting cones (secondary remodelling); therefore, the central canal size can be used as index of the remodelling activity. An experimental model in the rabbit femur was used to investigate, through central canal morphometry and frequency distribution analysis, the remodelling activity, comparing the middle of the diaphysis (mid-shaft) with the extremity (distal-shaft) and at the same level sectors and layers of the cortex in transversal sections. The study documented a higher density of canals in the mid-shaft than in the distal-shaft and a higher remodelling in the distal-shaft. There were no significant differences between dorsal, ventral, medial and lateral sectors at both mid-shaft and distal-shaft levels, while the number of canals was higher in the sub-periosteal layers than in the sub-endosteal. A lower threshold of 40 microm(2) was observed in the central canal area. Sealed osteons in the midshaft were 22.43% of the total number of osteons of the central canal area between 40 and 200 microm(2) and 0.44% of those of the distal-shaft. Micro-CT allowed a 3D reconstruction of the vascular canal system, which confirmed the branched network pattern rather than the trim architecture of the traditional representation. Some aspects like the lower threshold of the central canal size and the sealed osteons documented the plasticity of the system and its capacity for adaptation to changes in the haemodynamic conditions. PMID- 19874277 TI - Morphology of testes from transgenic rabbits: histological and ultrastructural aspects. AB - The aim of this study was to compare morphological characteristics of testes from transgenic (the WAP-hFVIII gene) and non-transgenic rabbits with emphasis on the histological and ultrastructural aspects. Samples of testes from both groups were fixed and embedded into Durcupan ACM for transmission electron microscopy. For histological analysis, semi-thin toluidine blue-stained sections were evaluated under a Jenaval light microscope. Male fertility was tested based on egg fecundity and blastocyst yield; transgene transmission was proved using PCR assay. Spermatogenesis in rabbit testes had not been destroyed both in transgenic and non-transgenic rabbits. No significant differences were found in the occurrence of individual cell organelles of the Sertoli cells in transgenic and non-transgenic rabbits. The ultrastructure of Leydig cells in testes of transgenic and non-transgenic rabbits was rather similar. No differences in the occurrence of individual organelles of Leydig cells between transgenic and non transgenic males were found. These results were in concert with fertilizing capacity of transgenic spermatozoa. The presented status of organelles in this study indicates functional activity of the analysed cells. PMID- 19874278 TI - The excurrent ducts of the testis of the emu (Dromaius novaehollandiae) and ostrich (Struthio camelus): Microstereology of the epididymis and immunohistochemistry of its cytoskeletal systems. AB - The volumetric proportion of the various ducts of the epididymis of the emu and ostrich and the immunohistochemistry of actin microfilaments, as well as cytokeratin, desmin and vimentin intermediate filaments, were studied in the various ducts of the epididymis of the emu and ostrich. The volumetric proportions of various ducts, which are remarkably different from those of members of the Galloanserae monophyly, are as follows: the rete testis, 5.2 +/- 1.4% for the emu and 2.4 +/- 1.8% for the ostrich; efferent ducts, 14.2 +/- 2.3% (emu) and 11.8 +/- 1.8% (ostrich); epididymal duct unit, 25.8 +/- 5.8% (emu) and 26.1 +/- 4.1% (ostrich) and connective tissue and its content, 54.7 +/- 5.8% (emu) and 60.0 +/- 4.9% (ostrich). Unlike in mammals and members of the Galloanserae monophyly, only vimentin was immunohistochemically demonstrated in the rete testis epithelium of the emu, and none of the cytoskeletal protein elements in the ostrich rete testis. The epithelium of the efferent ducts of the emu co-expressed actin, cytokeratin and desmin in the non-ciliated type I cells, and vimentin in the ciliated cell component. The ostrich demonstrated only cytokeratin in this epithelium. The ratite epididymal duct unit is different from that of mammals in lacking actin (only weaky expression in the ostrich), desmin and cytokeratin, and a moderate/strong immunoexpression of vimentin in the basal cells and basal parts of the NC type III cell in the epididymal duct unit. Immunoexpression of the microfilaments and intermediate filaments varied between the two ratite birds, as has been demonstrated previously in birds of the Galloanserae monophyly, and in mammals. PMID- 19874279 TI - Immunohistolocalization and gene expression of the carbonic anhydrase isoenzymes (CA-II and CA-VI) in glands associated with the canine lacrimal apparatus. AB - Cytosolic and secretory carbonic anhydrase isoenzymes (CA-II and CA-VI, respectively) were detected by immunohistolocalization using specific canine CA II and CA-VI antisera. CA-II and CA-VI were identified in glands associated with the canine lacrimal apparatus, such as lacrimal gland, superficial gland of the third eyelid (third eyelid gland) and tarsal gland. CA-II and CA-VI mRNA signals were also detected by reverse-transcriptase polymerase chain reaction in the same tissues. Some serous acinar cells and duct segments in the lacrimal gland and serous acinar cells in the third eyelid gland were immunopositive for anti-CA-II and CA-VI antisera. In particular, some immunopositive acini to CA-II and CA-VI on the edge of the third eyelid gland are histologically similar to sebaceous gland cells. Sebaceous gland cells in the tarsal and ciliary glands also showed immunopositivity to both CA antisera. CA-II and CA-VI gene transcripts were detected in the same regions. These results suggest that secreted CA-VI may form together with cytosolic CA-II, a high-activity isozyme mostly considered as a bicarbonate producer, in a mutually complementary system for the maintenance of bicarbonate levels to regulate pH in tear fluid and protect the corneal epithelia against injuries. In sebaceous gland cells in the lacrimal apparatus, CA-VI may be related to lipogenesis in an unknown function. PMID- 19874280 TI - Evaluation of membrane oxygenators and reservoirs in terms of capturing gaseous microemboli and pressure drops. AB - An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of neurologic complications. In this study, the capability of capturing and classification of gaseous emboli and pressure drop of three different membrane oxygenators (Sorin Apex, Terumo Capiox SX25, Maquet QUADROX) were measured in a simulated adult model of CPB using a novel ultrasound detection and classification quantifier system. The circuit was primed with 1000 mL heparinized human packed red blood cells and 1000 mL lactated Ringer's solution (total volume 2000 mL, corrected hematocrit 26-28%). After the injection of 5 mL air into the venous line, an Emboli Detection and Classification Quantifier was used to simultaneously record microemboli counts at post-pump, post-oxygenator, and post-arterial filter sites. Trials were conducted at normothermic (35 degrees C) and hypothermic (25 degrees C) conditions. Pre-oxygenator and post-oxygenator pressure were recorded in real time and pressure drop was calculated. Maquet QUADROX membrane oxygenator has the lowest pressure drops compared to the other two oxygenators (P < 0.001). The comparison among the three oxygenators indicated better capability of capturing gaseous emboli with the Maquet QUADROX and Terumo Capiox SX25 membrane oxygenator and more emboli may pass through the Sorin Apex membrane oxygenator. Microemboli counts uniformly increased with hypothermic perfusion (25 degrees C). Different types of oxygenators and reservoirs have different capability of capturing gaseous emboli and transmembrane pressure drop. Based on this investigation, Maquet QUADROX membrane oxygenator has the lowest pressure drop and better capability for capturing gaseous microemboli. PMID- 19874281 TI - Experience with the Levitronix CentriMag in the pediatric population as a bridge to decision and recovery. AB - Short-term mechanical circulatory support in the pediatric population with acute cardiac failure has traditionally been limited to extracorporeal membrane oxygenation given the limited availability of pediatric-sized pumps. The Levitronix CentriMag system (Thoratec Corporation, Pleasanton, CA, USA) offers expanded options for short-term support for this population. We report our experience with the successful use of the CentriMag in the pediatric population as a bridge to decision after postcardiotomy ventricular failure and as a bridge to recovery after heart transplantation. The first patient was bridged to a long term HeartMate II (Thoratec Corporation) as a bridge to potential recovery. The second patient was supported after severe graft failure post heart transplantation, with a full recovery. The Levitronix CentriMag has proven to be a versatile, safe, and effective short-term circulatory support system for our pediatric patients. PMID- 19874282 TI - Management of deep wound complications with vacuum-assisted therapy after Berlin Heart EXCOR ventricular assist device placement in the pediatric population. AB - Wound complications after ventricular assist device (VAD) placement remain a formidable challenge to surgeons. The Berlin Heart EXCOR VAD is a versatile pulsatile system that has been successful in pediatric patients of all ages and sizes. Prevention of device-related complications such as infection, particularly in pediatric patients, remains an essential issue in minimizing patient morbidity and mortality. The introduction of vacuum-assisted wound closure (VAC) therapy and its application in VAD-related wound complications provide an efficient and effective method for wound healing. We report our experience in the management of deep wound complications in two pediatric patients after placement of the Berlin Heart EXCOR VAD. The wound VAC system proved to achieve complete wound healing without any infectious complications. PMID- 19874283 TI - The Aachen miniaturized heart-lung machine--first results in a small animal model. AB - Congenital heart surgery most often incorporates extracorporeal circulation. Due to foreign surface contact and the administration of foreign blood in many children, inflammatory response and hemolysis are important matters of debate. This is particularly an issue in premature and low birth-weight newborns. Taking these considerations into account, the Aachen miniaturized heart-lung machine (MiniHLM) with a total static priming volume of 102 mL (including tubing) was developed and tested in a small animal model. Fourteen female Chinchilla Bastard rabbits were operated on using two different kinds of circuits. In eight animals, a conventional HLM with Dideco Kids oxygenator and Stockert roller pump (Sorin group, Milan, Italy) was used, and the Aachen MiniHLM was employed in six animals. Outcome parameters were hemolysis and blood gas analysis including lactate. The rabbits were anesthetized, and a standard median sternotomy was performed. The ascending aorta and the right atrium were cannulated. After initiating cardiopulmonary bypass, the aorta was cross-clamped, and cardiac arrest was induced by blood cardioplegia. Blood samples for hemolysis and blood gas analysis were drawn before, during, and after cardiopulmonary bypass. After 1 h aortic clamp time, all animals were weaned from cardiopulmonary bypass. Blood gas analysis revealed adequate oxygenation and perfusion during cardiopulmonary bypass, irrespective of the employed perfusion system. The use of the Aachen MiniHLM resulted in a statistically significant reduced decrease in fibrinogen during cardiopulmonary bypass. A trend revealing a reduced increase in free hemoglobin during bypass in the MiniHLM group could also be observed. This newly developed Aachen MiniHLM with low priming volume, reduced hemolysis, and excellent gas transfer (O(2) and CO(2)) may reduce circuit-induced complications during heart surgery in neonates. PMID- 19874284 TI - Comparison of two types of neonatal extracorporeal life support systems with pulsatile and nonpulsatile flow. AB - We compared the effects of two neonatal extracorporeal life support (ECLS) systems on circuit pressures and surplus hemodynamic energy levels in a simulated ECLS model. The clinical set-up included the Jostra HL-20 heart-lung machine, either the Medtronic ECMO (0800) or the MEDOS 800LT systems with company-provided circuit components, a 10 Fr arterial cannula, and a pseudo-patient. We tested the system in nonpulsatile and pulsatile flow modes at two flow rates using a 40/60 glycerin/water blood analog, for a total of 48 trials, with n = 6 for each set up. The pressure drops over the Medtronic ECLS were significantly higher than those over the MEDOS system regardless of the flow rate or perfusion mode (144.8 +/- 0.2 mm Hg vs. 35.7 +/- 0.2 mm Hg, respectively, at 500 mL/min in nonpulsatile mode, P < 0.001). The preoxygenator mean arterial pressures were significantly increased and the precannula hemodynamic energy values were decreased with the Medtronic ECLS circuit. These results suggest that the MEDOS ECLS circuit better transmits hemodynamic energy to the patient, keeps mean circuit pressures lower, and has lower pressure drops than the Medtronic Circuit. PMID- 19874285 TI - Apoptin enhances radiation-induced cell death in poorly responding head and neck squamous cell carcinoma cells. AB - Treatment of head and neck cancers is still rather poor and worldwide new treatment options are sought. Sensitizing radioresistant tumours by combining irradiation with other therapeutics to induce apoptosis are widely investigated. We examined whether chicken anaemia virus-derived apoptin protein would have a beneficial effect on irradiation of radiosensitive SCC61 and radioresistant SQD9 human head and neck squamous carcinoma cell lines. In both cell lines, concurrent exposure to irradiation and apoptin resulted in analysed mitochondrial cytochrome c release and in cleavage of caspase-3, whereas irradiation alone of SQD9 cells under identical conditions did not. Moreover, in comparison with the irradiation, only the synchronized treatment of apoptin and irradiation resulted in increased cell death in especially the radioresistant SQD9 cells, as measured by means of a colony survival assay. Our data reveal that apoptin treatment represents an effective way for enhancing radiotherapy of tumours responding poorly to radiotherapy. PMID- 19874286 TI - Sub-chronic exposure to methylmercury at low levels decreases butyrylcholinesterase activity in rats. AB - In this study, we examined the effects of low levels and sub-chronic exposure to methylmercury (MeHg) on butyrylcholinesterase (BuChE) activity in rats. Moreover, we examined the relationship between BuChE activity and oxidative stress biomarkers [delta-aminolevulinic acid dehydratase (delta-ALA-D) and malondialdehyde levels (MDA)] in the same animals. Rats were separated into three groups (eight animals per group): (Group I) received water by gavage; (Group II) received MeHg (30 microg/kg/day) by gavage; (Group III) received MeHg (100 microg/kg/day). The time of exposure was 90 days. BuChE and ALA-D activities were measured in serum and blood, respectively; whereas MDA levels were measured in plasma. We found BuChE and ALA-D activities decreased in groups II and III compared to the control group. Moreover, we found an interesting negative correlation between plasmatic BuChE activity and MDA (r = -0.85; p < 0.01) and a positive correlation between plasmatic BuChE activity and ALA-D activities (r = 0.78; p < 0.01), thus suggesting a possible relationship between oxidative damage promoted by MeHg exposure and the decrease of BuChE activity. In conclusion, long term exposure to low doses of MeHg decreases plasmatic BuChE activity. Moreover, the decrease in the enzyme is strongly correlated with the oxidative stress promoted by the metal exposure. This preliminary finding highlights a possible mechanism for MeHg to reduce BuChE activity in plasma. Additionally, this enzyme could be an auxiliary biomarker on the evaluation of MeHg exposure. PMID- 19874287 TI - Design, synthesis and pharmacological characterization of endomorphin analogues with non-cyclic amino acid residues in position 2. AB - A series of endomorphin-1 (EM-1) and endomorphin-2 (EM-2) analogues, containing non-cyclic amino acids (Ala, D-Ala, beta-Ala, NMeAla, D-NMeAla or Sar) instead of Pro in position 2 was synthesized, where NMeAla = N-methylalanine and Sar = N methylglycine, sarcosine. The opioid activity profiles of these peptides were determined in mu and delta opioid receptor (MOR and DOR)-representative binding assays and bioassays in vitro, as well as in the mouse hot-plate test in vivo. Finally, the degradation rates of all analogues in the presence of either rat brain homogenate or selected proteolytic enzymes were determined. Analogues of EM 2 were generally more potent than the respective analogues of EM-1. EM-2 analogues with D-Ala or D-NMeAla were about twofold more potent than the parent peptide and were least prone to degradation by brain homogenate, dipeptydyl peptidase IV and aminopeptidase M. In the in vivo test, [D-Ala(2)]EM-2 and [D NMeAla(2)]EM-2 showed much higher analgesic potency than EM-2 which confirmed the usefulness of structural modifications in obtaining new leads for pain-relief therapeutics. PMID- 19874289 TI - Effects of insulin-like growth factor-1 on rotenone-induced apoptosis in human lymphocyte cells. AB - Human peripheral blood lymphocytes have been useful as a putative model of oxidative stress-induced apoptosis for Parkinson's disease. The present work shows that rotenone, a mitochondrial complex I inhibitor, induced time- and concentration-dependent apoptosis in lymphocytes which was mediated by anion superoxide radicals (O(2)*(-))/hydrogen peroxide, depolarization of mitochondria, caspase-3 activation, concomitantly with the nuclear translocation of transcription factors such as NF-kappaB, p53, c-Jun and nuclei fragmentation. Since insulin-like growth factor-1 (IGF-1) interferes with a cell's apoptotic machinery when subjected to several stressful conditions, it is demonstrated here for the first time that IGF-1 effectively protects lymphocytes against rotenone through PI-3K/Akt activation, down-regulation of p53 and maintenance of mitochondrial membrane potential independently of ROS generation. These data might contribute to understanding the role played by IGF-1 against oxidative stress stimuli. PMID- 19874288 TI - Nano titanium dioxide particles promote allergic sensitization and lung inflammation in mice. AB - The purpose of this study was to investigate whether photocatalytic TiO(2) nanoparticles have adjuvant effect, when administered in combination with ovalbumin (OVA) in mice. Mice were immunized via intraperitoneal injections of OVA, OVA + TiO(2) or OVA + Al(OH)(3) and challenged with aerosols of OVA. At the end of the study, serum was analysed for content of OVA-specific IgE, IgG1 and IgG2a antibodies, and the bronchoalveolar lavage fluid (BALF) was analysed for content of inflammatory cells and levels of interleukin (IL)-4, IL-5, IL-10 and interferon-gamma. The TiO(2) particles promoted a Th2 dominant immune response with high levels of OVA-specific IgE and IgG1 in serum and influx of eosinophils, neutrophils and lymphocytes in BALF. The TiO(2) particles induced a significantly higher level of OVA-specific IgE than the standard adjuvant Al(OH)(3). However, the two substances were comparable regarding the level of eosinophilic inflammation and interleukins present in BALF. PMID- 19874290 TI - Counterfactual reasoning in surrogate decision making -- another look. AB - Incompetent patients need to have someone else make decisions on their behalf. According to the Substituted Judgment Standard the surrogate decision maker ought to make the decision that the patient would have made, had he or she been competent. Objections have been raised against this traditional construal of the standard on the grounds that it involves flawed counterfactual reasoning, and amendments have been suggested within the framework of possible worlds semantics. The paper shows that while this approach may circumvent the alleged problem, the way it has so far been elaborated reflects insufficient understanding of the moral underpinnings of the idea of substituted judgment. Proper recognition of these moral underpinnings has potentially far-reaching implications for our normative assumptions about accuracy and objectivity in surrogate decision making. PMID- 19874291 TI - Prognosis of patients with relapsed and chemoresistant gestational trophoblastic neoplasia transferred to the Peking Union Medical College Hospital. AB - OBJECTIVE: To analyse and compare the treatment outcome of the patients with gestational trophoblastic neoplasia (GTN) who were transferred to the Peking Union Medical College Hospital (PUMCH) because of chemoresistant or relapsed GTN. DESIGN: A retrospective study of the clinical features and treatment outcome of GTN after treatment failure elsewhere at the PUMCH. SETTING: The Department of Obstetrics and Gynecology, PUMCH, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. POPULATION: A total of 81 women with chemoresistant or relapsed GTN transferred and treated between January 2005 and December 2007. METHODS: A review of medical records of consecutively collected, referral cases of GTN was performed. The patients were classified according to the reasons for referral as having chemoresistant GTN if they had an incomplete response to previous treatment, and as having relapsed GTN if they had elevated serum beta-human chorionic gonadotropin (beta-hCG) levels, in the absence of a pregnancy, after the completion of initial treatment. MAIN OUTCOME MEASURES: Serologic complete remission (SCR) and relapse rates. RESULTS: The patients with chemoresistant and relapsed GTN achieved 52.6 and 76.7% of the long-term SCR rate, respectively; P = 0.035. Relapse rate and median time to relapse were similar between the chemoresistant GTN cohort and the relapsed GTN cohort after initial SCR (24 versus 35.7%, P = 0.417; 4 versus 3 months, P = 0.969). CONCLUSIONS: The patients with chemoresistant GTN had a worse outcome compared with patients with relapsed GTN. The importance of obtaining a normal beta-hCG level with treatment for GTN should be emphasised, and novel therapies should be pursued for these patients. PMID- 19874292 TI - Reasons for not seeking medical help for severe pelvic floor symptoms: a qualitative study in survivors of gynaecological cancer. AB - OBJECTIVE: (1) To explore the reasons for not seeking help for severe pelvic floor symptoms after gynaecological cancer treatment. (2) To determine the willingness to undergo treatment for these symptoms. (3) To invite suggestions to improve outpatient care. DESIGN: Qualitative study using semistructured interviews. SETTING: Vulvar, endometrial or cervical cancer survivors treated in the Academic Medical Centre, Amsterdam, the Netherlands between 1997 and 2007. POPULATION: Purposively selected sample from 138 eligible respondents to pelvic floor-related questionnaires, who were severely bothered by their symptoms (>75th percentile of domain sum score of questionnaires) and had not sought medical help. METHODS: After each semistructured interview, a checklist with reasons for not seeking help was complemented with newly mentioned reasons. The interviews were stopped when data saturation was accomplished, i.e. three consecutive interviewees had not revealed new reasons. The interviews were analysed by two researchers independently. MAIN OUTCOME MEASURE: Help-seeking behaviour for bothersome pelvic floor symptoms. RESULTS: Fifteen interviews were conducted. Most reported reasons for not seeking help were that women found their symptoms bearable in the light of their cancer diagnosis and lacked knowledge about possible treatments. Seven women were willing to undergo treatment. Eleven women stated that care should be improved, specifically by timely referral to pelvic floor specialists and additional care by oncology nurses. CONCLUSIONS: There is a need for standardised attention to adverse effects on pelvic floor function after cancer treatment. This could be realised by quantifying symptoms using questionnaires, standardised attention for such symptoms by gynaecological oncologists or oncology nurses, and timely referral to pelvic floor specialists of women with bothersome pelvic floor symptoms. PMID- 19874293 TI - Risk of ovarian failure and fertility preserving methods in girls and adolescents with a malignant disease. AB - Girls and young women suffering from a malignant disease that requires treatment with chemo- and/or radiotherapy are at risk of losing fertility. The most significant risk factors are age and type of treatment given. Preserving fertility is of high priority to both the young patient and her parents. This article reviews the effect of chemo- and radiotherapy on gonadal function, and thus fertility, and offers different fertility preserving methods based on the literature. Cryopreservation of ovarian tissue is a possible way of preserving fertility in this group of patients in the future. PMID- 19874294 TI - The menstrual disorder of teenagers (MDOT) study: determining typical menstrual patterns and menstrual disturbance in a large population-based study of Australian teenagers. AB - OBJECTIVE: The aim of this study was to: (1) establish the typical experience of menstruation for senior high school girls and (2) determine how many experience considerable menstrual disturbance that could require further investigation and management of underlying pathology. DESIGN: Cross-sectional study. SETTING: Senior High Schools in the Australian Capital Territory (ACT), Australia. POPULATION: A total of 1051 girls aged between 15 and 19 years. METHODS: Data based on a quantitative survey. MAIN OUTCOME MEASURES: Self-reports of menstrual bleeding patterns, typical and atypical symptoms and morbidities. RESULTS: Typical menstruation in adolescence includes pain (93%), cramping (71%), premenstrual symptoms (96%) and mood disturbance (73%). Highly significant associations were found between increasing severity of menstrual pain, number of menstrual-related symptoms, interference with life activities and school absence. These associations indicate that approximately 25% of the sample had marked menstrual disturbance: 21% experienced severe pain; 26% school absence; 26% suffering five or more symptoms; > or =24% reporting moderate to high interference with four out of nine life activities. Approximately 10% reported atypical symptoms associated with menstruation. Diagnosis of menstrual pathology in the sample was low, even though 33% had seen a GP and 9% had been referred to a specialist. CONCLUSIONS: Menstrual pain and symptoms are common in teenagers. Girls indicating moderate to severe pain in association with a high number of menstrual symptoms, school absence and interference with life activities should be effectively managed to minimise menstrual morbidity. Those girls who do not respond to medical management should be considered for further investigation for possible underlying pathology, such as endometriosis. PMID- 19874295 TI - High prevalence of bacterial vaginosis in adolescent girls in a tropical area of Ecuador. AB - Bacterial vaginosis (BV) is a common clinical syndrome, but data are scarce on the BV prevalence in tropical regions among sexually active and virgin adolescents. To estimate the prevalence of BV among adolescent girls in an Ecuadorian coastal town, girls were asked to complete a questionnaire on risk factors for BV and vaginal samples were examined. Bacterial vaginosis was present in 31.5% of 213 girls, and the prevalence was similar in self-reported virgin and sexually active girls (OR 1.06, 95% CI, 0.51-2.21, P = 0.88), although the power of this analysis was limited. The prevalence of BV was high among Ecuadorian adolescent girls, and did not appear to be associated with sexual activity. PMID- 19874296 TI - The levonorgestrel intrauterine system (Mirena) for the treatment of menstrual problems in adolescents with medical disorders, or physical or learning disabilities. AB - Menstrual problems are common in adolescence. Management can be very problematic in girls with disability or medical disorders, as their condition and other medications may mean they are less likely to achieve satisfactory control with standard medical treatments. Those with disability tend to tolerate menses poorly. We report experience with the levonorgestrel intrauterine system (LNG IUS) for treatment of menstrual problems in adolescents with a range of medical problems or with severe learning disability. It provided of significant therapeutic benefit for 12 of 14 participants, with the majority opting to continue for the 5-year duration of the device. The rates of expulsion, bleeding and amenorrhoea appear similar to those reported in older women, where contraception is the primary indication. PMID- 19874297 TI - Critical appraisal of technical problems with robotic urological surgery. AB - OBJECTIVE: To record the technical problems and complications associated with the use of da Vinci S robotic system (Intuitive Surgical, Sunnyvale, CA, USA) and to review previous reports. METHODS: We analysed our records for all machine- or instrument-related errors during the course of 340 consecutive robot-assisted urological operations at our centre from July 2006 to March 2009, using one robotic machine. The cause of the error (machine or human), troubleshooting methods and consequences of the errors were evaluated. RESULTS: The overall device failure rate was 10.9% (37/340). The most frequent technical problems were related to robotic instruments (23/37). Other failures included colour/hue changes in the console image, intermittent double vision, fused illuminator bulb and problems with the master tool-manipulator device (hand-piece unit), patient cart circuitry, patient-side manipulator arm, closed-circuit camera unit or camera cable. Of 37 problems, 28 (76%) were surmountable during the course of surgery. The overall conversions to standard open/laparoscopic procedure attributable to mechanical failures of the robot were 0.6% (2/340). There were no complications or direct harm to the patient in any case. Most faults could be corrected or bypassed with some addition to operating room time. CONCLUSIONS: Despite an association of various types of new technical problems with robotic surgery, it provides a safe mode of minimally invasive surgery with very low conversion rates attributable to it, and no direct patient injury. PMID- 19874298 TI - Real-time polymerase chain-reaction detection of pathogens is feasible to supplement the diagnostic sequence for urinary tract infections. AB - OBJECTIVE: To evaluate, in a prospective pilot study, the feasibility of identifying pathogens in urine using real-time polymerase chain reaction (PCR), and to compare the results with the conventional urine culture-based procedures. PATIENTS AND METHODS: Severe urinary tract infections (UTIs) are frequent in critically ill patients in the intensive-care unit (ICU) and in outpatients, and thus the reliable and fast identification of the bacteria is mandatory, but routine urine culture is time-consuming and the therapeutic regimen is often calculated and not culture-based. The study included 301 prospectively collected urine samples from 189 patients with suspected UTI, based in a university hospital in 2005, and included outpatients and those in the ICU. Urine culture with Cled-, MacConkey- and malt extract agar of all samples was followed by microbiological identification of the pathogens in 98 samples with visible growth. In parallel, all samples were assessed using qualitative real-time PCR based DNA detection and identification by labelled hybridization probes. RESULTS: In all, 15 dipstick culture-negative samples showed positive pathogen DNA identification by PCR. By contrast, 17 PCR-negative samples showed detectable pathogens by culture, of which 10 were not detectable on PCR because the identified pathogens were not represented in the probe panel. The sensitivity and specificity for detecting contaminated samples was 0.90 and 0.87, respectively. Overall, 95% of the mono-infection pathogens and 57% of the multiple-infection pathogens were detected concordantly with both methods. CONCLUSION: In this prospective pilot study PCR-based identification of pathogens was feasible for supplementing conventional culture methods for the diagnosis of UTI. The main advantage is the time saved in identifying the pathogens. The limited pathogen detection in multiple-infection-samples by PCR might be explained by competitive PCR amplification conditions. PMID- 19874299 TI - Open renal biopsy: comorbidities and complications in a contemporary series. AB - STUDY TYPE: Therapy (case series) Level of Evidence 4. OBJECTIVE: To report the indications and outcomes of a contemporary series of patients with contraindications to percutaneous renal biopsies (PRBs) who had an operative RB (ORB), as although ORB is a relatively infrequent procedure, it remains an important and underreported operation. PATIENTS AND METHODS: In a retrospective review of patients who had an ORB we examined comorbidities, indications, and 30 day morbidity and mortality. Preoperative comorbidities were stratified according to the Charlson comorbidity index. RESULTS: In all, 115 patients had ORB between 1991 and 2006 (mean age 48 years, range 18-83); 60% of the patients were American Society of Anesthesiologists class >or=3. The median Charlson comorbidity index score was 3, with a score of 0 in 20.9%, 1-2 in 27.8%, 3-4 in 30.4% and >or=5 in 20.9% of patients. Indications for an ORB included morbid obesity, failed PRB, coagulopathy, and solitary kidney. In all, 47.8% of patients had a serum creatinine level of <3.0 mg/dL, 34.8% of >3.0 mg/dL and 17.4% were dialysis dependent. There were 43 complications in 36 patients. The mortality rate after surgery was 0.8%. There were eight major complications in seven patients (6.1%) including cardiac arrest, stroke, sepsis, reoperation and re-intubation. There were minor complications 34 times in 31 patients (27%), the most common being wound infection, pneumonia, intraoperative transfusion of >2 units, arrhythmia, postoperative retroperitoneal bleed, and seep vein thrombosis. CONCLUSIONS: This study shows that there are significant comorbidities in patients referred to urologists for an ORB. With a mortality rate of 0.8% and major and minor complication rates of 6.1% and 27%, respectively, the ORB, while infrequent, carries a significant risk in this population that should be included in preoperative decision making and used for patient counselling. PMID- 19874300 TI - Initial experience of teaching robot-assisted radical prostatectomy to surgeons in-training: can training be evaluated and standardized? AB - OBJECTIVE: To measure the time and subjective quality of individual steps of robot-assisted radical prostatectomy (RARP), as RARP performed by trainees has recently become the most common technique of RP in the USA, and although outcomes from expert surgeons are reported, limited data are available to document training experiences. PATIENTS AND METHODS: The patients studied were from a prospective cohort of 178 participants (124 with training data). Transperitoneal RARP was performed by one faculty surgeon and one assistant from a rotation of four urological oncology fellows and three residents. RARP was divided into 11 steps, and staff times were recorded for each step. Trainee times and quality scores were recorded for each step, the later defined as grade A equal to staff (A+, no verbal coaching); B, minor corrections; and C, major corrections. Short term outcomes were recorded to assess the safety of the training. RESULTS: The mean (range) console time/case of trainees was 40 (10-123) min. The median console time for a complete case by faculty and by trainees (pooled group) was 128 and 231 min, respectively, an increase in 81%. Individual trainee-performed steps increased in time (compared to staff) by a median range of 50-177%, and the incidence of quality grades < A of 9-100%. Trainee quality grades for basic tissue-dissection steps were higher than for advanced tissue dissection and suturing. There was no downgrading for a major correction. Analysis of short-term outcomes suggested acceptable results in a training environment. The study is limited by no available validated training measurement tools, and a low frequency of beginner trainees advancing to more difficult steps during the rotation. CONCLUSIONS: During the initial exposure of trainees to RARP of <40 cases, we measured time and subjective quality grading of basic steps, and introduction to advanced steps. Training requires more procedure time, but does not appear to diminish expected outcomes. PMID- 19874301 TI - The effect of the approach to radical prostatectomy on the profitability of hospitals and surgeons. AB - OBJECTIVE: To evaluate the profit margins for radical retropubic prostatectomy (RRP), laparoscopic radical prostatectomy (LRP) and robot-assisted laparoscopic prostatectomy (RALP), and the effect on the reimbursement to the urologist, as there has been a dramatic increase in use of RALP, with the cost of the robot borne by hospitals. METHODS: Data on costs and payments to hospital and surgeon from 2003 to 2008 for RRP, LRP and RALP were obtained from the hospital and urology department. We determined the profit based on the difference between payments received and total cost. RESULTS: Between 2000 and 2008, 1279 RPs were performed at our private hospital. The introduction of RALP increased total number of RPs and replaced most RRPs. RRP represents the only procedure where payments exceed total costs. For RRP there was a significantly higher profit for patients with comorbidities. The type of payer had a large effect on profit. Medicare provides a small profit for RRP but a significant loss of >US$4000 for RALP. While all insurance companies resulted in losses for LRP and RALP, there was variability of almost $600/case for LRP and >$1400/case for RALP. RALP provided the highest reimbursement for the surgeon due to additional reimbursement for the S2900 code (use of robot). CONCLUSIONS: The introduction of RALP has increased the case volume at our hospital and improved profits for the surgeon. The hospital loses money on each LRP and RALP case compared with RRP, which provides a small profit. PMID- 19874302 TI - Treatment of long ureteric strictures with buccal mucosal grafts. AB - OBJECTIVE: To describe the reconstruction of long ureteric strictures using buccal mucosal patch grafts and to report the intermediate-term functional outcome. PATIENTS AND METHODS: Between November 2000 and October 2006 reconstruction of seven long ureteric strictures using buccal mucosal patch grafts and omental wrapping was performed in five women (one with bilateral strictures) and one man. The surgical steps of stricture reconstruction and wrapping with omentum are described in detail. Stricture recurrence was defined as persistent impaired ureteric drainage as displayed by imaging techniques or the necessity to prolong JJ stenting. Patency rates and stricture recurrence-free survival rates are provided. RESULTS: With a median follow up of 18 months five of the seven strictures were recurrence-free. Graft take was good in all patients. In one asymptomatic patient, there was impaired ureteric drainage on the reconstructed side, and in one patient with reconstruction of both ureters prolonged JJ stenting of one side was necessary. In both patients, the impaired drainage was caused by persistent stricture below the reconstructed ureteric segments. CONCLUSIONS: At intermediate-term follow-up in a small group of patients with long ureteric strictures, treatment with buccal mucosal patch grafts and omental wrapping showed good functional outcome. PMID- 19874303 TI - Synchronous panniculectomy with stomal revision for obese patients with stomal stenosis and retraction. AB - OBJECTIVE: To report our experience of synchronous panniculectomy with stomal revision in morbidly obese patients after radical cystectomy (RC) and ileal conduit urinary diversion (UD). Abnormal skin folds with an uneven surface, stomal retraction and stomal stenosis result in a poorly fitting appliance which leads to urinary leakage, need for frequent change of appliances and skin excoriation. PATIENTS AND METHODS: In all, 302 RCs with UD were done by one surgical team between 2002 and 2008, with ileal conduit diversion in 182 (60%); 18 had a body mass index (BMI) of >35 kg/m(2), and among them four had severe stomal stenosis with retraction. We report the technique we used for managing stomal stenosis in these patients. RESULTS: The mean (range) BMI of the patients was 42 (38-46) kg/m(2); all were women. The mean (sd) operative duration was 2 (0.5)h. The drain was removed once the drainage was <25 mL in 24 h. The mean (sd) hospital stay was 3 (1) days; there were no significant complications. After a mean follow-up of 3 years there was no recurrent stomal stenosis or retraction. CONCLUSIONS: The unique advantage of this procedure is that it avoids laparotomy in a morbidly obese patient, and it provides excellent cosmesis while correcting the stomal complication. PMID- 19874304 TI - Outcome analysis of robotic pyeloplasty: a large single-centre experience. AB - OBJECTIVE: To present our experience and outcomes of robot-assisted laparoscopic pyeloplasty (RALP) for pelvi-ureteric junction obstruction (PUJO). PATIENTS AND METHODS: This was a prospective study of 85 consecutive patients who had RALP for PUJO at our institute from July 2006 to December 2008. The preoperative evaluation included intravenous urography (IVU) and diuretic renography. The type of pyeloplasty was decided based on the size of the pelves, presence of crossing vessel, level of ureteric insertion and the length of obstruction. All surgery was done through a transperitoneal approach using four or five ports. The follow up comprised IVU and renal dynamic scintigraphy. Relevant data were collected and analysed for perioperative morbidity, complications and long-term functional outcomes. RESULTS: In all, 86 RALPs were performed, including one bilateral, 41 right-sided and 43 left-sided cases. The mean operative time was 121 min, including an anastomosis time of 47 min. The mean estimated blood loss was 45 mL. The drain was removed within 48 h. The mean hospital stay was 2.5 days. Three patients had stents that migrated upwards, and prolonged drainage. The success rate was 97% (82/85) with a mean follow-up of 13.6 months. CONCLUSIONS: RALP is highly effective for managing PUJO, with low morbidity, quick recovery and a durable success rate. PMID- 19874305 TI - Chronic kidney disease among men with lower urinary tract symptoms due to benign prostatic hyperplasia. AB - OBJECTIVE: To analyse potential association of various clinical characteristics of benign prostatic hyperplasia (BPH) with chronic kidney disease (CKD) among men presenting with lower urinary tract symptoms (LUTS) secondary to BPH of varying severity. PATIENTS AND METHODS: We reviewed the data of 2741 consecutive patients who presented to our clinic with LUTS secondary to BPH. For our analysis, CKD was defined by an elevated serum creatinine level or decreased estimated glomerular filtration rate (eGFR). Univariate and multivariate logistic regression analyses were used to address associations of CKD with various clinical characteristics. RESULTS: Of the 2741 patients, 161 (5.9%) were initially classified as having CKD (serum creatinine > or =133 micromol/L). In multivariate analysis, peak flow rate (P = 0.001) and a history of hypertension and/or diabetes (both P < 0.001) were significantly associated with CKD, whereas age, body mass index, prostate specific antigen level, prostate volume, postvoid residual, or International Prostate Symptom Score (IPSS) were not. When individual symptoms from the IPSS were analysed, only weak stream (P = 0.041) and hesitancy (P = 0.048), both obstruction-related, were significantly associated with CKD status in age and comorbidity-adjusted analyses. The results of secondary analysis with CKD defined as an eGFR of <60 mL/min/1.73 m(2) were similar. CONCLUSION: Our results show that decreased peak flow rate and a history of hypertension and/or diabetes are significantly associated with CKD in men seeking management for LUTS from BPH of varying severity. PMID- 19874306 TI - Pelvic fracture-related injuries of the bladder neck and prostate: their nature, cause and management. AB - OBJECTIVE: To report our experience of bladder neck injuries, which are a well recognized but rare consequence of pelvic fracture-related trauma to the lower urinary tract, as we have been unable to find any reference in the English literature to their specific nature, cause and management in adults. PATIENTS AND METHODS: In the last 10 years we have treated 15 men with bladder neck injuries after pelvic fracture. Two were treated at our centre by delayed primary repair. Thirteen were initially treated elsewhere and presented to us 3 months to 5 years after their injury with intractable incontinence and various other symptoms most notably recurrent urinary infection and gross haematuria. Twelve of the injuries were at or close to the anterior midline and associated with lateral compression fractures or 'open-book' injuries. Five of them were confined to the bladder neck and prostatic urethra; the other seven extended into the subprostatic urethra. Four of these were associated with a coincidental typical rupture of the posterior urethra. All had an associated cavity involving the anterior disruption of the pelvic ring. Two of the injuries, following particularly severe trauma, were a simultaneous complete transection of the bladder neck and of the bulbo membranous urethra with a sequestered prostate between. We have seen this in children before but not in adults. Another injury, also after particularly severe trauma, was an avulsion of the anterior aspect of the prostate. We have not seen this described before. Fourteen patients underwent lower urinary tract reconstruction and one underwent a Mitrofanoff procedure. All of the 14 had a layered reconstruction of the prostate and bladder neck and in 13, this was supplemented with an omental wrap. RESULTS: In all patients with an anterior midline rupture, the primary injury appeared to be to the prostate and prostatic urethra with secondary involvement of the bladder neck and the subprostatic urethra. The Mitrofanoff procedure was successful. Of the 14 patients with a layered reconstruction one, without an omental wrap, broke down but was successfully repaired on a subsequent occasion. The four patients who also had a ruptured urethra had a simultaneous bulbo-prostatic anastomotic urethroplasty, two of which required further attention. Eight of the 14 reconstructed patients underwent implantation of an artificial urinary sphincter (AUS) for sphincter weakness incontinence, in seven of whom this was successful. Two of these had previously undergone implantation of an AUS with an unsatisfactory outcome and were made continent by bladder neck reconstruction. The other six patients had acceptable urinary incontinence by reconstruction of the bladder neck and urethra alone. CONCLUSIONS: The primary injury is to the prostate and prostatic urethra. The bladder neck and subprostatic urethra are involved secondarily by extension. These injuries have a particular cause and a particular location with a predictable outcome. They need to be identified and treated promptly as they do not heal spontaneously and otherwise cause considerable morbidity. We also describe two particular types of bladder neck injury that we have not seen described before in adults. PMID- 19874307 TI - Dorsal onlay lingual mucosal graft urethroplasty for urethral strictures in women. AB - OBJECTIVE: To describe the technique and results of dorsal onlay lingual mucosal graft (LMG) urethroplasty for the definitive management of urethral strictures in women. PATIENTS AND METHODS: In all, 15 women (mean age 42 years) with a history suggestive of urethral stricture who had undergone multiple urethral dilatations and/or urethrotomy were selected for dorsal onlay LMG urethroplasty after thorough evaluation, from October 2006 to March 2008. After a suprameatal inverted-U incision, the dorsal aspect of the urethra was dissected and urethrotomy was done at the 12 o'clock position across the strictured segment. Tailored LMG harvested from the ventrolateral aspect of the tongue was then sutured to the urethrotomy wound over an 18 F silicone catheter. RESULTS: The preoperative mean maximum urinary flow rate of 7.2 mL/s increased to 29.87 mL/s, 26.95 mL/s and 26.86 mL/s with a 'normal' flow rate curve at 3, 6 and 12 months follow-up, respectively. One patient at the 3-month follow-up had submeatal stenosis and required urethral dilatation thrice at monthly intervals. At the 1 year follow-up, none of the present patients had any neurosensory complications, urinary incontinence, or long-term functional/aesthetic complication at the donor site. CONCLUSION: LMG urethroplasty using the dorsal onlay technique should be offered for correction of persistent female urethral stricture as it provides a simple, safe and effective approach with durable results. PMID- 19874308 TI - Severe liver dysfunction from hepatitis C virus reactivation following alemtuzumab treatment for chronic lymphocytic leukaemia. PMID- 19874309 TI - Lenalidomide on alternative days is effective in myelodysplastic syndrome with 5q deletion. PMID- 19874310 TI - Increased levels of tissue factor activity and procoagulant phospholipids during treatment of children with acute lymphoblastic leukaemia. AB - The use of L-asparaginase (L-ASP) in paediatric patients with acute lymphoblastic leukaemia (ALL) is associated with thrombotic complications. We evaluated the activities of tissue factor (TFa), thrombomodulin (TMa) and procoagulant phospholipids (PPL) in 26 consecutive children with ALL (25 B-ALL and one T-ALL) treated by the French Acute Lymphoblastic Leukemia group (FRALLE)-2000 protocol. Samples were obtained at diagnosis, after glucocorticoid (GC) therapy, during the induction phase with L-ASP, vincristine (VCR) and adriamycin (ADR), during the re induction and within the week after treatment. Plasma levels of TFa, TMa and PPL increased gradually and significantly during the different phases of the treatment, with higher levels observed during the induction period, and decreased after treatment discontinuation. In vitro studies showed that the different drugs used for ALL treatment could induce a weak expression of TF and procoagulant activity (PCA) on normal and leukaemia blood cells, while a marked effect was observed on endothelial cells. In conclusion, these data indicate that, in addition to the well-identified increased in coagulation factors and inhibitor deficiencies, the injury of the endothelium could lead to the release of TF and PPL and could contribute to the hypercoagulability of children treated for ALL. PMID- 19874311 TI - Laboratory correlates for a phase II trial of romidepsin in cutaneous and peripheral T-cell lymphoma. AB - Romidepsin has shown promise in the treatment of T-cell lymphomas, and so we evaluated molecular endpoints gathered from 61 patients enrolled on a phase II trial of romidepsin in cutaneous and peripheral T-cell lymphoma at the National Institutes of Health. The endpoints included histone H3 acetylation and ABCB1 gene expression in peripheral blood mononuclear cells (PBMCs); ABCB1 gene expression in tumour biopsy samples; and blood fetal haemoglobin levels (HbF), all of which were increased following romidepsin treatment. The fold increase in histone acetylation in PBMCs at 24 h was weakly to moderately well correlated with the pharmacokinetic parameters C(max) and area under the curve (AUC)(last) (rho = 0.37, P = 0.03 and rho = 0.36, P = 0.03 respectively) and inversely associated with clearance (rho = -0.44; P = 0.03). Histone acetylation in PBMCs at 24 h was associated with response (P = 0.026) as was the increase in fetal haemoglobin (P = 0.014); this latter association may be due to the longer on study duration for patients with disease response. Together, these results suggest that pharmacokinetics may be an important determinant of response to histone deacetylase inhibitors (HDIs) - the association with histone acetylation in PBMCs at 24 h is consistent with a hypothesis that potent HDIs are needed for a critical threshold of drug exposure and durable activity. PMID- 19874312 TI - Quantitative assessment of PTPN11 or RAS mutations at the neonatal period and during the clinical course in patients with juvenile myelomonocytic leukaemia. AB - To evaluate minimal residual disease (MRD) after chemotherapy and haematopoietic stem cell transplantation in juvenile myelomonocytic leukaemia (JMML), a locked nucleic acid-allele specific quantitative polymerase chain reaction (LNA-AS-qPCR) was developed for 13 patients (four types of PTPN11 mutation and four types of RAS mutation). The post-transplant MRD detected by LNA-AS-qPCR analysis was well correlated with chimerism assessed by short tandem repeat PCR analysis. Non intensive chemotherapy exerted no substantial reduction of the tumour burden in three patients. There was no significant difference in the quantity of RAS mutant DNA after spontaneous haematological improvement in 4 patients with NRAS or KRAS 34G > A during a 2- to 5-year follow-up. PTPN11, NRAS, or KRAS mutant DNA was detected from Guthrie card dried blood in five of seven patients (who were aged <2 years at diagnosis) at a level of 1.0-6.5 x 10(-1) of the values at diagnosis. Accordingly, these five patients might have already reached a subclinical status at birth. Considering the negative correlation between mutant DNA level in neonatal blood spots and age at diagnosis, JMML patients with a larger tumour burden at birth appeared to show earlier onset. PMID- 19874313 TI - Epigenetic regulation of the non-canonical Wnt pathway in acute myeloid leukemia. AB - Wnt5a is a member of the Wnt family of proteins that signals through the non canonical Wnt/Ca(2+)pathway to suppress cyclin D1. Deregulation of this pathway has been found in animal models suggesting that it acts as tumour suppressor in acute myeloid leukemia (AML). Although DNA methylation is the main mechanism of regulation of the canonical Wnt pathway in AML, the role of WNT5A abnormalities has never been evaluated in this clinical setting. The methylation status of WNT5A promoter-exon 1 was analyzed by methylation-specific PCR and sequencing in eleven AML-derived cell lines and 252 AML patients. We observed WNT5A hypermethylation in seven cell lines and in 43% (107/252) of AML patients. WNT5A methylation was associated with decreased WNT5A expression (P < 0.001) that was restored after exposure to 5-Aza-2'-deoxycytidine. Moreover, WNT5A hypermethylation correlated with upregulation of CYCLIN D1 expression (P < 0.001). Relapse (15%vs 37%, P < 0.001) and mortality (61%vs 79%, P = 0.004) rates were lower for patients in the non-methylated group. Disease-free survival and overall survival at 6 and 7 years, respectively, were 60% and 27% for unmethylated patients and 20% and 0% for hypermethylated patients (P = 0.0001 and P = 0.04, respectively). Interestingly, significant differences were also observed when the analysis was carried out according to cytogenetic risk groups. We demonstrate that WNT5A, a putative tumor suppressor gene in AML, is silenced by methylation in this disease and that this epigenetic event is associated with upregulation of CYCLIN D1 expression and confers poor prognosis in patients with AML. PMID- 19874314 TI - Supraciliary wrinkles and botulinum toxin A. AB - BACKGROUND: Injection of botulinum toxin into certain areas of face that carry a high risk of ptosis (danger zone) needs caution in application. An example is the lateral forehead, particularly the lower portion. AIM: In this study, we evaluated the efficacy and safety of treating supraciliary wrinkles in the lower lateral forehead by injections of botulinum toxin at the temporal hairline, keeping a reasonable distance from danger zone. METHODS: In this randomized clinical trial, 40 women (mean age 35 years) were selected and divided into two groups, A and B. both groups were treated with botulinum toxin to treat wrinkles in the frown area, as well as frontal lines and lateral canthus lines. Group B received extra injections at each temporal line for treatment of supraciliary wrinkles. RESULTS: There was a significant difference in total wrinkle number and mean number of wrinkles between the two groups after injections (paired t-test, P < 0.01). No ptosis was seen in either group. CONCLUSIONS: Injection of botulinum toxin type A through the temporal hairline to correct supraciliary wrinkles seems to be safe and effective. PMID- 19874315 TI - c-Ski promotes skin fibroblast proliferation but decreases type I collagen: implications for wound healing and scar formation. AB - BACKGROUND: Accelerating wound healing is always accompanied by excessive scar formation. The focus in chronic wounds has been promoting the proliferation of tissue repair cells while decreasing collagen deposition. Smad3 null mice display more rapid wound closure and reduced scar formation. We hypothesized that c-Ski, acting as a co-repressor of transforming growth factor-beta1/Smad3 in epithelial cells and as a complicated regulator of embryo fibroblast proliferation, may play such a role through modulation of skin fibroblast function. AIM: To investigate the effect of c-Ski on skin fibroblast proliferation, cell-cycle progression, type I collagen secretion and myofibroblast differentiation. The potential involvement of Smad3 was also investigated. METHODS: Cultured rat skin fibroblasts were used. Immunocytochemistry and reverse transcription (RT)-PCR was used to examine the localization and expression of c-Ski. Plasmid transfection technology was used to produce c-Ski or/and Smad3 overexpression. Cell proliferation was analysed by 5-bromo-2-deoxyuridine incorporation; cell cycle by fluorescence-activated cell sorting; type I collagen expression by immunocytochemistry, RT-PCR and western blotting; and myofibroblast differentiation by western blotting. RESULTS: c-Ski was expressed in cultured skin fibroblasts. Overexpression of c-Ski was able to promote skin fibroblast proliferation and accelerate cell-cycle progression through inhibiting Smad3 activity. It also decreased type I collagen protein and mRNA expression through inhibiting Smad3 activity. It did not affect fibroblast-myofibroblast differentiation. CONCLUSIONS: Because of the important role of fibroblast proliferation and collagen secretion in tissue repair and scar formation, we speculate that c-Ski may be a new candidate molecule for accelerating wound healing and decreasing scar formation. PMID- 19874316 TI - A randomized, double-blind, vehicle-controlled study of a preparation containing undecylenoyl phenylalanine 2% in the treatment of solar lentigines. AB - BACKGROUND: Solar lentigines are common, benign, cosmetically disfiguring lesions. Available physical treatments are effective, but they are costly and carry risks of side-effects. OBJECTIVE: To evaluate the efficacy and safety of a preparation containing undecylenoyl phenylalanine 2% in the topical treatment of solar lentigines. METHODS: In total, 36 patients with solar lentigines of the hands were randomly assigned to apply the active preparation on one side and the vehicle alone on the other side, twice daily for 12 weeks. Patients were evaluated monthly for efficacy and safety. RESULTS: In all, 30 patients (28 women and 2 men; age range 47-75 years) completed the study. The duration of lesions ranged from 8 months to > 10 years. All patients responded partially on the side of the active treatment. Of the partial responders, 19 (63.3%) had moderate improvement and 11 (36.6%) had marked improvement. Improvement was evident from the first follow-up visit. On the side of the vehicle, 26 remained stable (86.6%) and 4 (13.3%) had partial improvement. There was a significant difference (P < 0.01) in efficacy of the active preparation vs. the vehicle. Using patient assessment ratings, 80% were 'much more satisfied/more satisfied' with the result. The reported side-effects were minor and included erythema and itching or burning on the side of active treatment. CONCLUSIONS: Undecylenoyl phenylalanine 2% is a novel depigmenting agent, which possibly acts as an alpha-melanocyte stimulating hormone antagonist, thus inhibiting melaninogenesis. It achieved a significant lightening of the lesions with minimal side-effects. Most patients were satisfied with the improvement. Undecylenoyl phenylalanine 2% may represent a safe, effective and inexpensive therapeutic alternative for solar lentigines. PMID- 19874317 TI - Are dark-skinned people really protected from ultraviolet radiation? AB - BACKGROUND: Premature ageing of the skin (photoageing) results from the action of ultraviolet radiation (UVR) on skin. One of the histopathological findings of photoageing is the presence of solar elastosis in the dermis. Skin pigmentation is protective against UVR. AIM: To evaluate the presence of solar elastosis in dark-skinned people. METHODS: Normal facial skin biopsies of 147 dark-skinned and 140 light-skinned people were examined histopathologically for solar elastosis. The degree of solar elastosis was graded on a five-point scale by a panel of dermatopathologists blinded to patient demographics. RESULTS: There were 112 of 140 (80%) light-skinned and 50 of 147 (34%) dark-skinned patients with high-grade solar elastosis. In the dark-skinned patient group, high-grade solar elastosis was seen in 29 of 61 (47.5%) Hispanic and 5 of 49 (10.2%) African American subjects. CONCLUSIONS: Dark-skinned people are not completely protected from the effects of UVR. PMID- 19874318 TI - Effects of hyaluronan and iodine on wound contraction and granulation tissue formation in rat skin wounds. AB - BACKGROUND: Hyaluronan (HA) plays an important role in the repair of damaged skin and has been used for the treatment of wounds. Iodine is a mild topical antiseptic. AIM: A mixture of high molecular weight HA with the iodine complex KI(3) (hyiodine) was reported to accelerate wound healing in patients with diabetes and patients after surgery. We investigated how this mixture affects wound contraction, granulation tissue (GT) and wound edges in excision skin wounds in rats. METHODS: Hyiodine was applied to full-thickness wounds made on the back of rats. The areas of the contracting wounds were calculated from digital photographs. The moving edges of the wound were studied by histological methods. The properties of GT were studied in wounds in which contraction was prevented by the insertion of plastic rings. The effects of hyiodine were compared with those of high molecular weight (1200 kDa) HA, low molecular weight (11 kDa) HA and KI(3) solution. RESULTS: Hyiodine accelerated wound contraction significantly in the first 5 days of healing. On day 3, hyiodine-treated wounds had reduced to 63% of the original area, whereas the wound area in saline-treated animals was 75% of the original size. The proliferating epidermis was thicker in hyiodine-treated animals on day 7. In the wounds with inserted rings, hyiodine caused little change in GT, but the weight of the crust/exudate formed on the top of the wound was increased by 351% compared with only minor changes caused by the hyiodine components alone. CONCLUSIONS: Hyiodine supports wound healing by stimulating wound contraction and epidermal proliferation and by keeping the wound moist through increased exudation. PMID- 19874319 TI - Pemphigus herpetiformis: analysis of the autoantibody profile during the disease course with changes in the clinical phenotype. AB - BACKGROUND: Pemphigus herpetiformis (PH) is a rare dapsone-responsive variant of pemphigus, characterized by annular and vesiculopustular cutaneous lesions. Most PH serum samples contain autoantibodies against desmoglein (Dsg)1, but not Dsg3, and the presence of the latter is almost invariably associated with mucosal involvement, as predicted based on the 'Dsg compensation theory'. METHODS: We describe a patient with features characteristic of PH with histologically eosinophilic spongiosis who repeatedly tested positive for anti-Dsg3 but not anti Dsg1 autoantibodies by ELISA. To investigate whether the peculiar clinical phenotype was due to a distinct immunological profile, the patient's serum was tested by ELISA and immunoblotting using recombinant forms of Dsg3. RESULTS: Serum samples were found to have low and high reactivity against the EC1 and the EC4 domains of Dsg3, respectively, whereas the autoantibodies belonged predominantly to the IgG1 and IgG4 subclasses. The overall immunological profile was typical of pemphigus vulgaris. The patient finally developed isolated oral erosions 22 months after initial presentation, without significant changes in the autoantibody profile and of the targeted antigenic sites. CONCLUSIONS: Our patient presented features characteristic of PH. Although circulating anti-Dsg3 antibodies were present, the patient had only cutaneous involvement for a long period. Our findings indicate that the proposed Dsg compensation theory cannot always explain the clinical phenotype, changes in which may occur without apparent modification of the autoantibody profile and antibody specificity. Hence, additional factors, such as Fcgamma-dependent neutrophil activation, may critically affect the clinical presentation of pemphigus. PMID- 19874320 TI - Serum T helper 1 cytokine levels are greater in patients with alopecia areata regardless of severity or atopy. AB - BACKGROUND: Alopecia areata (AA) is an organ-specific autoimmune disease characterized by folliculotropic T-cell infiltrates around anagen-stage hair follicles. The role of T helper (Th)1 and Th2 cytokines in the pathogenesis of AA have not been established. AIM: To determine whether serum cytokine profiles define the severity of the AA phenotype or are affected by co-existent atopy. METHODS: In total, 17 serum cytokines were measured and compared in 269 patients with AA of varying severity with and without atopy and 18 unrelated controls. RESULTS: Of the 269 patients with AA, 96% had active disease and 54% were atopic. The disease phenotype was transient patchy AA in 27 patients, persistent patchy AA in 89 and alopecia totalis or alopecia universalis in 153. Levels of Th1, interleukin (IL)-1 receptor antagonist (ra) and IL-8 levels were higher in all patients with AA than in controls. IL-1alpha, IL-12 and tumour necrosis factor alpha levels were higher in patients with AA and atopy than in patients with AA without atopy. CONCLUSIONS: Increased Th1 serum cytokines (IL-2, IL-12 and interferon-gamma) and IL-1ra levels are associated with AA regardless of disease severity or the presence of atopy. PMID- 19874321 TI - Coudability hairs: a revisited sign of alopecia areata assessed by trichoscopy. AB - BACKGROUND: We have previously reported several trichoscopic (dermatoscopic) characteristics, such as black dots, 'exclamation-mark' hairs, broken hairs, yellow dots and clustered short vellus hairs as being useful clinical indicators for alopecia areata (AA). 'Coudability hairs', which are normal-looking hairs tapered at the proximal end, have been previously reported as another sign of AA. AIMS: To use trichoscopy to evaluate coudability hairs as a clinical indicator for the disease activity of AA and a substitute-marker for the hair-pull test. METHODS: Trichoscopic examinations of hair loss and perilesional areas on the scalps of 100 East Asian patients with AA were performed using a dermatoscope. Using Spearman's rank-order correlation coefficient by rank test, we examined the correlations of scores between coudability and AA disease activity, severity or duration and other trichoscopic features, and then evaluated the coudability score as a surrogate-marker for the hair-pull test. RESULTS: Coudability scores correlated positively with AA disease activity, hair-pull tests, short duration, black dots and exclamation-mark hairs, and correlated negatively with short vellus hairs. CONCLUSIONS: Coudability hairs, more closely perceived by trichoscopy, are useful-markers for disease activity in AA and provide a surrogate-marker for the hair-pull test. PMID- 19874322 TI - Association of HLA-DRB1* and keloid disease in an Afro-Caribbean population. AB - BACKGROUND: Keloid disease (KD) is a fibroproliferative dermal tumour of unknown aetiology. The high incidence of familial clustering in KD, its prevalence in certain races and its concordance in identical twins suggest a strong genetic predisposition to keloid formation. The highest incidence of keloids is found in black populations, where the incidence has been estimated to be up to 16%. The most polymorphic genetic system in vertebrates is the major histocompatibility complex (MHC) also known as the human leucocyte antigen (HLA) system. The MHC has been shown to be strongly associated with numerous conditions. Of particular relevance is the association of DR2 with dermal fibrotic diseases including sarcoidosis and systemic sclerosis. AIMS: To investigate the aetiology of KD and the potential involvement of the MHC. METHODS: We compared the HLA-DRB1 phenotype frequencies of Afro-Caribbean patients of Jamaican origin with keloid scars against those seen in a control population of the same ethnicity (n = 121; mean age 34.8 years, range 14-88). In total, 180 keloid cases of Afro-Caribbean origin, recruited from Kingston, Jamaica, were evaluated in the study (mean age 29.7 years, range 2-90 years). HLA-DRB1 alleles were determined in all participants using a semiautomated typing system of reverse hybridization PCR with sequence-specific oligonucleotide probes. HLA-DRB1* phenotype frequencies were established in the Jamaican Afro-Caribbean population and comparisons made between cases and controls. Furthermore, the influence of multiple vs. single lesions, patient gender and family history were also investigated. RESULTS: Differences were observed between the disease and control cohorts although none was significant. CONCLUSIONS: This study does not support an association between HLA-DRB1* alleles and susceptibility to keloid in people of Afro-Caribbean origin. PMID- 19874323 TI - Randomized controlled trial comparing store-and-forward teledermatology alone and in combination with web-camera videoconferencing. AB - BACKGROUND: Studies on the reliability of teledermatology have shown considerable variability in results. Only one study has compared asynchronous and synchronous methods. OBJECTIVES: This report describes DERMATEL, a prospective, randomized diagnostic-concordance study that sought to evaluate the relative advantages, in terms of reliability, of two remote consultation techniques. METHODS: Patients referred by 18 general practitioners were randomized (4 : 4 : 2) to three study groups: store and forward (SF), hybrid videoconferencing-SF (VC-SF), and a control group. In total, 457 patients were assigned: 192 to the SF group, 176 to the VC-SF group and 89 to the control group. High-quality still images were used throughout, with additional use of standard web-camera (webcam) videoconferencing in the VC-SF group. All patients were also seen by the same dermatologist in a face-to-face (FTF) consultation, considered the practical reference standard. Two different dermatologists assessed concordances between the teledermatology and FTF consultations. RESULTS: There were no significant differences in age, gender or diagnostic category between the three groups, and the images (82%), clinical history (91%) and diagnostic confidence (89%) were high-quality. Online management was possible for 70% of cases. Agreement between teledermatology and the FTF consultation was high for both diagnosis (> 0.85) and treatment (> 0.78). Concordance in diagnosis was influenced by image quality (P < 0.001), confidence in diagnosis (P < 0.001) and need for conventional consultation (P < 0.001), rather than by quality of clinical history (P = 0.58) or method of teleconsultation (P = 0.340). CONCLUSIONS: Intraobserver reliability is very high in teledermatology. When history taking and training in digital photography are standardised, a hybrid system with audio is no better than SF alone. PMID- 19874324 TI - Psychiatric treatments in dermatology: an update. AB - There is a considerable degree of connection between psychiatry and dermatology. This connection is relevant both for diagnosis and management of dermatological pathology. This article summarises common psychiatric conditions seen in patients with skin disease, both primary psychiatric disorders and psychiatric disorders secondary to dermatological pathology. Diagnosis of relevant psychiatric conditions such as anxiety, depression, obsessive-compulsive disorder, delusional parasitosis and dermatitis artefacta, and psychiatric treatments are discussed. It gives an update of psychopharmacology relevant to the dermatologist including important interactions between psychotropic and dermatological agents. PMID- 19874325 TI - Aggressive digital papillary adenocarcinoma: a review. AB - Vigorous treatment of aggressive digital papillary adenocarcinoma (ADPA), including amputation, has been recommended by most authors, but the appropriateness and effectiveness of excision as an alternative to amputation has not been systematically evaluated. To evaluate the appropriateness and effectiveness of excision as an alternative to amputation in the treatment of ADPA, we reviewed the clinical presentations, treatments and patient outcomes presented in case reports on ADPA available on Ovid MEDLINE. We also assessed the results of immunohistochemical staining for proliferation markers in one patient in order to explain the nonaggressive nature of ADPA noted in that patient. Except for the duration of lesions, there was no significant difference in clinical outcome between the excision and amputation groups. We also found that p63 may be a useful marker for distinguishing primary ADPA from metastatic adenocarcinomas. In addition, the intensity of Ki67 expression in tumour cells may be a marker of aggressive behaviour and thus be helpful in therapeutic decision-making. Wide excision with or without sentinel lymph-node biopsy is a feasible alternative to amputation. It should be considered in patients who present with a long-standing history of ADPA without evidence of underlying bone invasion or distant metastasis and with low-intensity expression of proliferation markers. PMID- 19874326 TI - Perinatal exposure to endotoxin and the development of eczema during the first 6 years of life. AB - BACKGROUND: Previous studies have reported a protective association between high levels of exposure to endotoxin during infancy and the development of subsequent eczema within the first 6 months of life. AIM: To investigate the association between exposure in infancy to endotoxin from mattress dust and the development of eczema up to age of 6 years in 2166 children participating in the German Influences of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood (LISA) study, an ongoing population-based birth-cohort study. METHODS: Endotoxin levels in house dust samples collected at 3 months after birth were quantified using the kinetic Limulus amebocyte lysate assay. Specific IgE antibodies to common food and aeroallergens were measured using radioallergosorbent test, fluorenzyme immunoassay (Pharmacia CAP system) when children were 2 and 6 years old. Information on eczema symptoms and physician diagnosed eczema were collected at each follow-up using a questionnaire. RESULTS: No association was found between endotoxin exposure from mattresses (the mattresses of each child and their parents were examined) during infancy and the development of eczema symptoms or doctor-diagnosed eczema by 6 years of age (OR = 1.1, 95% CI 0.5-2.3, and OR = 1.1, 95% CI 0.4-3.3, respectively). No association was found when children with only atopic eczema. CONCLUSION: Endotoxin exposure during infancy is unlikely to have a large long-term effect on the development of eczema, especially the atopic form. PMID- 19874328 TI - Advances in paracoccidioidomycosis. AB - Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America. It is becoming globally relevant, as increasing numbers of cases have been detected in returning travellers and immigrants from endemic regions. It is characterized by pulmonary involvement, lymphadenopathy, and chronic progression of mucocutaneous lesions. Untreated, systemic disease can be severe and fatal. Skin features are common and characteristic, enabling the dermatologist to diagnose infection early and prevent the development of serious sequelae. This review outlines the clinical features and management of paracoccidioidomycosis and discusses notable recent developments in molecular diagnosis, prognostics and therapies. PMID- 19874327 TI - Corticosteroid/cyclophosphamide pulse treatment in South African patients with pemphigus. AB - BACKGROUND: Treatment of pemphigus remains a challenge. Corticosteroid/cyclo phosphamide pulse treatment has been used to reduce the morbidity associated with long-term treatment with high-dose corticosteroids. We describe our experience with pulse treatment in South African patients with pemphigus. OBJECTIVES: To assess, in patients who achieved remission of pemphigus, the number of pulses, time and total amounts of steroid and cyclophosphamide required to achieve remission of pemphigus, any side-effects and the long-term outcome. METHODS: Patient charts were reviewed retrospectively. In those who had remission of disease (resolution of cutaneous lesions and no new mucosal lesions), details of medication were analysed. The relationships between medication, disease severity, type of disease and patient demographics were investigated. RESULTS: Of the 70 patients, 35 achieved remission as defined in the study criteria; 43% of them with < 6 treatment pulses. Neither the type nor severity of pemphigus correlated with the number of treatment pulses or time to remission. However, 73% of patients who presented with severe disease did receive additional oral corticosteroids between treatment pulses. Lymphopenia occurred in 80% of patients, who needed more treatment pulses (P = 0.002) and thus larger total amounts of oral (P = 0.006) and intravenous (P = 0.02) cyclophosphamide to eventually achieve remission. Of the 35 patients who achieved remission, 94% remained in remission, although seven patients required retreatment to achieve this. CONCLUSIONS: Pulse treatment in our setting was associated with minimal morbidity. In the nine patients who relapsed, the regimen was not strictly followed, emphasizing the importance of compliance. Our use of low-dose oral corticosteroids between treatment pulses, early in the management of poorly controlled patients, supports the current modified recommendation of Pasricha. PMID- 19874329 TI - Effect of levothyroxine treatment on clinical symptoms and serum cytokine levels in euthyroid patients with chronic idiopathic urticaria and thyroid autoimmunity. AB - BACKGROUND: Screening for thyroid autoimmunity in patients with chronic idiopathic urticaria (CIU) is generally recommended. However, there are not yet sufficient data as to whether levothyroxine treatment is beneficial for the clinical symptoms of CIU in patients with thyroid autoimmunity. AIM: We investigated the effect of levothyroxine treatment on clinical symptoms and serum tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and interferon (IFN) gamma levels in euthyroid patients with CIU and thyroid autoimmunity. METHODS: In total, 15 patients with CIU and positive thyroid autoantibodies were randomized to receive either levothyroxine plus 5 mg/day desloratadine (suppression group, n = 8) or 5 mg/day desloratadine alone (control group, n = 7) for 12 weeks. Clinical symptoms of CIU, thyroid hormone levels, thyroid antibodies and serum cytokine levels were assessed at baseline and after the treatment. RESULTS: There were significant improvements in pruritus score and severity of weals in both groups compared with baseline values, but when the two groups were compared, there was no significant difference in the patients' clinical symptoms. Thyroid antibody titres were not different according to intragroup and intergroup analysis. In the suppression group, serum IFN-gamma and TNF-alpha levels were increased after treatment with levothyroxine compared with baseline values and there was a borderline statistical significance (P = 0.05 for both). CONCLUSIONS: These results suggest that levothyroxine treatment is not a reasonable option in euthyroid patients with CIU and thyroid autoimmunity. Augmentation of cytokine production after levothyroxine treatment seems to be related to the immunomodulatory effects of TSH-suppressive treatment. PMID- 19874330 TI - Predictors of patient satisfaction with initial diagnosis and management of malignant melanoma. AB - BACKGROUND: Malignant melanoma (MM), accounts for around 10% of skin cancers. To date, there have been few data on patient satisfaction with initial management of MM. OBJECTIVE: To identify the predictors of patient satisfaction with initial diagnosis and management of MM. METHODS: Data on 214 patients were collected using a questionnaire filled in by a clinician during a face-to-face interview when the patient attended an appointment at a tertiary melanoma centre. Age, gender, ethnic origin, date of diagnosis, site of lesion, and overall stage at diagnosis and at interview were obtained from the hospital notes. Patients were asked about their satisfaction level at the end. RESULTS: In total, 64 (29.9%) patients were dissatisfied with the time they had to wait to receive a diagnosis. Patients whose initial biopsy was taken by a dermatologist were more satisfied than those whose biopsy was taken by a general practitioner (GP) (P < 0.003) and women were more dissatisfied than men (P = 0.04). Delay in diagnosis (P < 0.001) and number of visits (P < 0.001) were found to be predictors for dissatisfaction in univariate analysis, but in multivariate analysis, only the number of visits (P < 0.001) was a significant predictor of patient satisfaction. For each additional visit made by the patient, the odds of dissatisfaction increased by 3.5 times, irrespective of who did the initial biopsy, any delay in diagnosis, and the age and gender of the patient. CONCLUSIONS: Patients whose initial biopsy was taken by dermatologist were more satisfied than those with a biopsy taken by a GP. The number of visits was an important predictor of patient satisfaction. PMID- 19874331 TI - Axillary hair removal with 1064-nm Nd:YAG laser increases sweat production. AB - BACKGROUND: Laser-assisted hair removal has become a popular treatment for eradication of body hair. Many studies have been published concerning the safety and efficacy of several laser systems. Adverse events are hyperpigmentation, hypopigmentation, erythema, oedema, scarring, pain and blistering. Changes in sweating have not previously been reported. AIM: To investigate the effects on axillary sweating of hair removal by a 1064-nm neodymium:yttrium-aluminium-garnet (Nd:YAG) laser. METHODS: The sweating function of both axillae was evaluated objectively by the iodine starch test for planimetry measurement and subjectively using a visual analogue scale (VAS) before the treatment, and 1 month and 1 year after the last session. RESULTS: The difference in hyperhidrotic activity before and after treatment was significant (P < 0.05), and these differences persisted 1 year after the last evaluation. CONCLUSIONS: The results of this study confirm that treatment of axillary hair using the 1064-nm Nd:YAG laser can cause hyperhidrosis, and this effect is not transient. We did not evaluate the eccrine glands histologically, which is a limitation of the study. PMID- 19874332 TI - Neurotropin inhibits both capsaicin-induced substance P release and nerve growth factor-induced neurite outgrowth in cultured rat dorsal root ganglion neurones. AB - BACKGROUND: Neurotropin (NTP), a biological extract from rabbit skin inoculated with vaccinia virus, is an effective analgesic and anti-allergic agent, and has antipruritic effects in various dermatoses including eczema, dermatitis and urticaria. In patients receiving haemodialysis who have pruritus, NTP appears to exert its antipruritic effect by lowering the plasma levels of substance P (SP), but its underlying mechanisms are not fully understood. AIM: To investigate the antipruritic mechanisms of NTP. METHODS: The effects of NTP on capsaicin-induced SP release from neonatal rat dorsal root ganglion (DRG) neurones were assessed by measuring SP concentrations in culture media by a competitive ELISA. The effects of NTP on nerve growth factor (NGF)-induced neurite outgrowth were assessed by measuring the length of the longest process of cultured DRG neurones. The neuronal cytotoxicity of NTP was determined using a methylthiazole tetrazolium cytotoxicity assay. RESULTS: NTP dose-dependently inhibited capsaicin-induced release of SP from cultured DRG neurones, whereas NTP alone had no effect on SP release. Moreover, NTP dose-dependently inhibited NGF-induced neurite outgrowth in cultured DRG neurones. NTP had no observable cytotoxicity. CONCLUSIONS: These results suggest that NTP exerts its antipruritic effects by inhibiting both SP release and neurite outgrowth of cutaneous sensory nerves. PMID- 19874333 TI - Genotoxic effects of 1064-nm Nd:YAG and 532-nm KTP lasers on fibroblast cell cultures. AB - BACKGROUND: Several different laser types are used in cutaneous surgery. The neodymium:yttrium-aluminium-garnet (Nd:YAG) and frequency-doubled Nd:YAG (KTP, potassium titanyl phosphate) lasers are widely used in dermatology. OBJECTIVES: To investigate the possible genotoxic effects on fibroblasts of irradiation with a 1064-nm Nd:YAG laser and a 532-nm KTP laser. METHODS: Fibroblast cell cultures were exposed to each of the lasers, using 10-mm spot size at 60 ms pulse duration with 10, 20, 40 J/cm(2) and 3, 6, 12 J/cm(2) fluences, respectively. Fibroblasts in passages 1-6 were used. During laser irradiation, 96-well microplate cultures were kept on a cooling block and transported on ice and in the dark, and processed immediately for single-cell gel electrophoresis (SCGE) assay (also known as a comet assay). RESULTS: DNA damage was determined by computerized assessment of comet assay. There was increasing damage with increasing numbers of passages. For the Nd:YAG laser, the greatest damage occurred on passages 5 and 6, whereas the greatest damage appeared at passages 3 and 4 for KTP and returned to baseline at passages 5 and 6. Damage also increased with each dose increment for both wavelengths. At the highest dose for both wavelengths (Nd:YAG 40 J/cm(2) and KTP 12 J/cm(2)), damage was higher with the Nd:YAG laser. CONCLUSIONS: Different patterns of cellular damage were seen for different cell-culture passages, treatment doses, and laser wavelengths. These dose ranges are generally used for the treatment of vascular and pigmented lesions and for rejuvenation purposes. As replicative ageing or cell senescence is one of the critical factors determining the extent of cell damage induced by laser therapy, these results may have important implications for clinical practice. PMID- 19874334 TI - The profile of dermatological problems in primary care. AB - BACKGROUND: Cutaneous disease is thought to account for 10-15% of patient consultations with general practitioners, but relatively little is known about the demography of dermatological conditions in primary care. AIM: To assess the proportion and diagnostic profile of dermatological conditions seen in primary care in the southeast of Scotland, and to draw comparisons with secondary dermatological care. METHODS: General practitioners in 13 general practices were asked to note all skin-related consultations during a 2-week period. The case notes of these patients were reviewed, and diagnosis and treatment was recorded. Patients who had consulted for the same skin disorder on >or= 3 occasions during the previous year were invited for assessment by a consultant dermatologist. Where possible, the case notes from 10% of all consultations during the 2-week study period were examined to assess accuracy of recording. RESULTS: The percentage of consultations relating to cutaneous disorders varied between practices, ranging from 3% to 18.8%, with a mean of 8.4%. Eczema accounted for 22.5%, infections 20.3% and benign tumours for 11.4% of consultations with a dermatological basis. In contrast, in secondary care, benign tumours accounted for 23.8%, malignant tumours for 16.4% and eczema for 16.3% of dermatological consultations. CONCLUSIONS: Dermatological disorders make up a significant proportion of general practitioners' workload. The diagnostic profile of primary care dermatology differs markedly from that of hospital practice. General practitioners may benefit from training specifically tailored to the common primary-care dermatological conditions. PMID- 19874336 TI - Clopidogrel: mechanisms of action and review of the evidence relating to use during skin surgery procedures. AB - Patients who have skin surgery may be taking medication that increases the likelihood of bleeding, such as clopidogrel, aspirin, warfarin, heparin and nonsteroidal anti-inflammatory drugs (NSAIDS). All of these may increase the risk of perioperative and postoperative bleeding. This article examines the mechanism of action of clopidogrel, current practice, and evidence for or against continuing its use during skin surgery. The mechanisms of action of aspirin, warfarin, heparin and NSAIDS will also be briefly discussed. PMID- 19874335 TI - Mucosal (oral and vulval) lichen planus in women: are angiotensin-converting enzyme inhibitors protective, and beta-blockers and non-steroidal anti inflammatory drugs associated with the condition? AB - AIM: To determine whether there is an association between the use of angiotensin converting enzyme (ACE) inhibitors, beta-blockers and nonsteroidal anti inflammatory drugs (NSAIDS) in women with mucosal (oral and vulval) lichen planus (LP) compared with a control population. METHODS: This was a retrospective review of medical records in dedicated vulval and oral clinics in hospitals. The study population comprised 141 women with vulval LP and 106 women with oral LP. Medications taken at the time of diagnosis were recorded. RESULTS: Patients with mucosal LP were more likely to be on NSAIDS and beta-blockers, but less likely to be on ACE inhibitors compared with controls. All three groups were found to have an inverse relationship with ACE inhibitors, but no association was found between patients with oral LP and beta-blockers. CONCLUSIONS: Beta-blockers and NSAIDS are associated with LP, suggesting that withdrawal of these drugs should be considered. Further studies are needed to confirm or refute the inverse relationship between mucosal LP and use of ACE inhibitors. PMID- 19874337 TI - Therapeutic options for palmoplantar pustulosis. AB - Palmoplantar pustulosis (PPP) is a common chronic and recurrent pustular dermatosis characterized by multiple sterile pustules and erythematous plaques on the palms and soles. The exact cause and pathogenesis of the disease remain unknown, and there is still debate about whether PPP is a variant of psoriasis or a distinct condition. A review of the medical literature revealed that a wide range of treatments have been used in the treatment of PPP over the years. The literature in PPP is restricted to case reports or small case series, and there is a lack of well-documented clinical studies, which makes it difficult to select an ideal therapy for the condition. The purpose of this review is to discuss the current therapy options for PPP, based on results of randomized controlled trials. PMID- 19874338 TI - A case-control analysis and laboratory study of the two feet-one hand syndrome in two dermatology hospitals in China. AB - BACKGROUND: Two feet-one hand syndrome (bilateral plantar tinea pedis with coexistent unilateral tinea manuum) is commonly seen in dermatology clinics, but the cause of the unilateral hand involvement remains unresolved. AIMS: To investigate the unilateral hand involvement in this syndrome. METHODS: This was a case-control study. The experimental group comprised 113 patients with bilateral tinea pedis and unilateral tinea manuum and the control group comprised 44 patients with tinea pedis only, without tinea manuum. Clinical data were recorded and pathogens were identified by fungal examination. The predominant pathogen, Trichophyton rubrum, was genotyped by PCR amplification of tandem repeat elements from the ribosomal DNA nontranscribed spacer region. RESULTS: Scratching habits were significantly different between the groups, and there was a significant relationship between tinea manuum and the hand reportedly used to scratch the feet. In analysis of isolates from the feet and the involved hand, 94.5% of pairs were of the same species, and 80% of pairs had the same genotypes. CONCLUSIONS: Contact between hands and feet probably results in the transmission of dermatophytes from the feet to the scratching hand. PMID- 19874339 TI - Oxidative protein damage and antioxidant status in systemic lupus erythematosus. AB - BACKGROUND: Oxidative stress may play a role in the pathogenesis of systemic lupus erythematosus (SLE). Proteins are one of the main targets for oxidants, due to their abundance in biological systems and their high rate constants for reaction. AIM: To evaluate differences in oxidative protein damage and antioxidant status between patients with SLE and healthy controls, and to explore whether oxidative protein damage has a role in either the disease activity or the organ damage in SLE. METHODS: Using spectrophotometry and ELISA, the levels of multiple markers of protein oxidation and antioxidant status in the serum of 62 patients with SLE and 62 healthy controls were evaluated. RESULTS: We found that levels of multiple markers of protein oxidation and activities of superoxide dismutase (SOD) and myeloperoxidase were increased, whereas levels of protein thiol and activities of glutathione peroxidase and catalase were reduced in serum from patients with SLE compared with controls. Disease activity index correlated positively with erythrocyte sedimentation rate and levels of serum protein carbonyl (PC), 3-nitrotyrosine and C-reactive protein, and negatively with levels of serum protein thiols and activities of SOD, glutathione peroxidase and catalase activities in patients. There was a significant difference in the serum PC levels between patients with and without arthritis or arthralgia. The same was true when patients with and without cardiac involvement, and patients with and without renal disease were analysed. CONCLUSIONS: The findings suggest that protein oxidation may play a role in the pathogenesis of chronic organ damage in SLE. PMID- 19874340 TI - Comparison of two dye lasers in the treatment of port-wine stains. AB - BACKGROUND: Port-wine stains (PWS) are congenital capillary malformations that persist throughout life. Laser therapy is a common treatment for PWS, and pulsed dye laser is the current treatment of choice. AIM: To compare the clinical results on untreated PWS of two dye lasers with different wavelengths and pulse duration: a flashlamp-pumped dye laser (FPDL) and a long-pulse-duration dye laser (LPDL). METHODS: In total, 24 patients were treated on 4-6 test areas with both laser types using high-energy and low-energy fluences. An FPDL with 0.45 ms pulse duration tuned to 585 nm was compared with an LPDL with 1.5 or 3.0 ms pulse duration tuned to 595 nm. Twelve weeks later the degree of lightening was evaluated by a blinded assessor. Pain was assessed directly after treatment with both lasers, using a visual analogue scale. RESULT: There was no significant difference overall between the two systems in lightening of the lesion or in patient-reported pain. CONCLUSION: Both laser systems are equivalent in terms of efficacy and pain. PMID- 19874341 TI - A localized form of aquagenic syringeal acrokeratoderma. PMID- 19874342 TI - What's new in atopic eczema? An analysis of systematic reviews published in 2007 and 2008. Part 2. Disease prevention and treatment. AB - This review summarizes clinically important findings from systematic reviews indexed in bibliographical databases between August 2007 and August 2008 that dealt with disease prevention (six reviews) and treatment of atopic eczema (seven reviews). Regarding disease prevention, two independent systematic reviews found some clinical trial evidence that ingestion of probiotics by mothers during pregnancy might reduce the incidence of subsequent eczema. Another review failed to find any clear benefit of prebiotics in eczema prevention. Although furry pets are often cited as causing allergic disease, a systematic review of observational studies found no evidence that exposure to cats or dogs at birth increases eczema risk. One very large review of studies of breastfeeding found some evidence of a protective effect on eczema risk, although all the studies were limited by their observational nature. A German group has attempted an overview of eczema prevention studies with a view to informing national guidelines. In terms of eczema treatment, two systematic reviews have confirmed the efficacy of topical tacrolimus ointment. Another review of 31 trials confirms the efficacy of topical pimecrolimus, although many of those trials were vehicle controlled, which limits their clinical utility. A review of 23 studies of desensitization therapy for allergic diseases found some evidence of benefit for eczema, which needs to be explored further. Despite the popularity of antistaphylococcal therapies for eczema, a Cochrane Review of 21 trials failed to show any clear benefit for any of the therapies for infected or clinically noninfected eczema. Another Cochrane Review dealt with dietary exclusions for people with eczema and found little evidence to support any dietary exclusion, apart from avoidance of eggs in infants with suspected egg allergy supported by evidence of sensitization. A review of 13 studies of probiotics for treating established eczema did not show convincing evidence of a clinically worthwhile benefit, an observation that has been substantiated in a subsequent Cochrane Review. PMID- 19874343 TI - What's new in atopic eczema? An analysis of systematic reviews published in 2007 and 2008. Part 1. Definitions, causes and consequences of eczema. AB - This review summarizes clinically important findings from nine systematic reviews indexed in bibliographical databases between August 2007 and August 2008, dealing with the definitions, causes and consequences of atopic eczema (AE). One review of diagnostic criteria found that out of 10 sets of criteria, only the UK refinement of the Hanifin and Rajka criteria have been adequately tested (in 19 studies). Another review of 20 named outcome measures found that only three [SCORing Atopic Dermatitis (SCORAD), the Eczema Area and Severity Index (EASI) and the Patient Oriented Eczema Measure (POEM)] had been tested and found to perform adequately. In terms of risk factors for developing disease, a review found that birth by caesarean section increased the risk of asthma and hay fever but not eczema in offspring. A review of cohort studies also found evidence that adverse psychological factors in early life predispose to more atopic disease and a worse prognosis. Another review found that filaggrin gene mutations were a consistently strong risk factor for AE, with a person carrying one of these mutations being over three times more likely to exhibit eczema. It has been suggested that eczema might protect against some forms of cancer, and a detailed systematic review of brain cancers that included 53,233 participants from eight case-control and cohort studies found that having atopic disease was associated with a 39% reduction in glioma risk, a finding that was also present for just those with AE (odds ratio 0.69, 95% CI 0.58-0.82). A further review of case control and cohort studies failed to find any association between keeping furry pets at birth and subsequent risk of eczema, although pet fur might still exacerbate established disease. In terms of disease consequences, a review found that eczema was the commonest cause of chronic sleep loss in young people, affected the whole family. A review of four economic studies from the US found that the annual cost of AE in the States was as high as $3.8 billion when indirect costs are included. PMID- 19874344 TI - Livedoid vasculopathy: thrombotic or inflammatory disease? AB - The pathogenesis of livedoid vasculopathy (LV) is still unclear. However, with increasing knowledge of disorders of coagulation over the past few years, the cause of some cases of LV has been elucidated. LV has now been described in association with hyperhomocysteinaemia, activated protein C resistance, and prothombin gene mutations in the absence of significant underlying inflammatory disease. When LV is seen in association with systemic lupus erythematosus or polyarteritis nodosa, it is probably due to the pro-coagulable state induced by these diseases rather than being true vasculitis. We review recent insights into LV provided by published clinical cases and discuss its pathogenesis. PMID- 19874345 TI - Relapse-associated autoantibodies to BP180 in a patient with anti-p200 pemphigoid. AB - Anti-p200 pemphigoid and bullous pemphigoid (BP) are autoimmune subepidermal blistering diseases characterized by autoantibodies to a 200-kDa dermal antigen (p200) and two hemidesmosomal proteins (BP180 and BP230), respectively. We report a 70-year-old man with haemorrhagic blisters, widespread crusted erosions, and the immunopathological characteristics of anti-p200 pemphigoid. Treatment with doxycycline, topical corticosteroids and immunoadsorption led to rapid clinical remission. However, 19 weeks later, a relapse occurred with generalized itchy urticarial erythema and tense blisters. At this time, both strong dermal and epidermal IgG staining was detected by indirect immunofluorescence microscopy on salt-split skin, and autoantibodies against both p200 and the 16th noncollagenous (NC16A) domain of BP180 were found. Interestingly, the relapse was associated not only with the detection of autoantibodies to a second autoantigen (BP180), but also with an altered clinical phenotype. This case was a unique occasion to directly monitor the emergence of intermolecular epitope spreading during the course of an autoimmune bullous disorder. PMID- 19874346 TI - Pilar leiomyoma with cytological atypia: cutaneous counterpart of atypical uterine leiomyoma? PMID- 19874347 TI - Polymorphism of glutathione S-transferases M1 and T1: susceptibility to solar keratoses in an Italian population. AB - BACKGROUND: Polymorphisms of glutathione S-transferases (GSTs) are linked to skin cancer, but data on their association with solar keratosis (SK) are few and conflicting. AIM: To verify the possible association between the development of SK and the 'null' GSTM1 and/or T1 genotype. METHODS: Analysis of the GSTM1 and T1 genotype of 33 subjects with >=3 solar keratoses and of 150 controls, before and after stratification based on smoking habits, sun exposure and immunosuppression. RESULTS: The GST T1 null allele is significantly (P < 0.03) associated with increased prevalence of SK in our population. CONCLUSIONS: Our study, the first on a Mediterranean population, shows the existence of a correlation between SK and the GST T1 null genotype. This result points out significant differences between subjects of different ethnic and geographical origin and warrants further investigation on a larger population, and ethnically different populations. PMID- 19874348 TI - Generalized eruptive lentiginosis induced by chemotherapy. AB - Lentigines are characterized by brown macules developing due to increased proliferation of melanocytes in the dermoepidermal junction. Many drugs, including immunosuppressants and immunomodulators, have been shown to cause generalized lentiginosis. We describe a case of lentiginosis induced by cancer chemotherapy, an extremely rare occurrence. PMID- 19874349 TI - Koilonychia in carpal-tunnel syndrome. PMID- 19874350 TI - Stevens-Johnson syndrome and toxic epidermal necrolysis due to anticonvulsants share certain clinical and laboratory features with drug-induced hypersensitivity syndrome, despite differences in cutaneous presentations. AB - BACKGROUND: Drug-induced hypersensitivity syndrome (DIHS)/drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is characterized by late disease onset, fever, rash, hepatic dysfunction, haematological abnormalities, lymphadenopathy and often, human herpesvirus (HHV) reactivation. The diagnosis of DIHS is based on the combined presence of these findings. Anticonvulsants are a major cause of DIHS and may also cause Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We examined whether SJS/TEN due to anticonvulsants display similar clinical and laboratory features seen in DIHS. METHODS: Patients diagnosed with SJS or TEN due to anticonvulsants (n = 8) were examined and their clinical features and laboratory findings were compared with patients with anticonvulsant-related DIHS (n = 6). RESULTS: Seven of the eight patients with SJS/TEN developed symptoms > 3 weeks after starting anticonvulsants. Hepatic dysfunction was present in six patients with SJS/TEN and five patients with DIHS. Leucocytosis and/or eosinophilia was noted in seven patients with SJS/TEN and four patients with DIHS. Only one patient in the SJS/TEN group had atypical lymphocytosis; this was present in four patients with DIHS. Reactivation of HHV-6 was detected in one of the four patients tested in the SJS/TEN group, although it was seen in five of the six patients with DIHS. CONCLUSIONS: TSJS/TEN due to anticonvulsants may exhibit some clinical and laboratory features of DIHS. The nature of the cutaneous involvement should be emphasized in the diagnosis of DIHS. PMID- 19874351 TI - Postirradiation linear morphoea. AB - Postirradiation morphoea is an uncommon side-effect of radiotherapy. We report a 74-year-old woman who was treated with radiotherapy for endometrial carcinoma. About 3.5 years after the first dose of radiotherapy, the patient developed linear morphoea starting from the radiation port and affecting distant, nonirradiated skin. Lesions of radiation-induced morphoea are generally described as well-demarcated, indurated plaques with varying amounts of associated erythema; however, there is no previous publication of unilateral band-like distribution of morphoea associated with radiotherapy, to our knowledge. PMID- 19874352 TI - Immunohistochemistry in Kaposi's sarcoma. AB - The importance of immunohistochemistry (IHC) to our understanding, ability to confidently diagnose and treat Kaposi's sarcoma (KS) has grown steadily in the past few decades. IHC has been performed on many KS specimen types, with > 100 different primary antibodies. Therefore, it is not surprising that IHC has helped unravel the histogenesis, understand the pathogenesis and facilitate the diagnosis of KS and identify novel therapeutic targets in the disease. This paper reviews the literature on the use of IHC in the study of KS. PMID- 19874353 TI - Mutations in the keratin 9 gene in Pakistani families with epidermolytic palmoplantar keratoderma. AB - BACKGROUND: Keratins are heteropolymeric proteins that form the intermediate filament cytoskeleton in epithelial cells. The common basic structure of all keratins is organized in a central alpha-helical rod domain flanked by nonhelical, variable head and tail regions. Most mutations in keratins are found in the central alpha-helical rod domain. Keratin 9 (K9) is expressed only in the suprabasal layers of palmoplantar epidermis. Mutations in the keratin 9 gene (KRT9) have been shown to cause epidermolytic palmoplantar keratoderma (EPPK; OMIM 144200), an autosomal dominant genodermatosis characterized clinically by diffuse hyperkeratosis limited to the palms and soles, and histologically by epidermolysis in suprabasal layers of the epidermis. AIM: To elucidate the genetic basis of EPPK in five Pakistani families. METHODS: Using microsatellite markers localized to the areas around the type I keratin gene cluster on chromosome 17q21, genotyping of these families was performed, followed by sequencing of the KRT9 gene. RESULTS: The analysis resulted in the identification of two novel (p.M157K and p.Y454H) and two recurrent (p.M157T and p.R163Q) mutations in the KRT9 of all five families. All mutations occurred within the highly conserved helix initiation or termination motif of K9. CONCLUSIONS: The affected members of all five families possess mutations in the KRT9 gene that severely affect heterodimer formation with the type II keratin partner. The results of our study further underscore the crucial role of K9 protein in the palmoplantar epidermis. PMID- 19874354 TI - In vitro activity of fluconazole, itraconazole, voriconazole and terbinafine against fungi causing onychomycosis. AB - BACKGROUND: Onychomycosis is one of the commonest dermatological diseases worldwide. The antifungal activity of current medications varies, and treatment failure occurs in 25-40% of treated patients. AIMS: To evaluate the in vitro antifungal activity of itraconazole, fluconazole, terbinafine and voriconazole against isolates taken from patients with onychomycosis. METHODS: Nail isolates were evaluated according to methods described in the protocols of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (AFST-EUCAST) and the Clinical and Laboratory Standards Institute (CLS M38-A), and a CLSI M38-A modified technique for dermatophytes. Antifungal agents tested included terbinafine, itraconazole, voriconazole and fluconazole. RESULTS: In total, 103 isolates of Candida species (n = 58), Fusarium species (n = 10), Fusicoccum dimidiatum (n = 4), Scytalidium hyalinum (n = 1) and dermatophytes (n = 30) were evaluated. Itraconazole and voriconazole were the most active agents against Candida species, whereas terbinafine and voriconazole were most potent against dermatophytes. Fusarium species had the highest minimum inhibitory concentration (MIC) values with all antifungal agents. CONCLUSIONS: The aetiological agents of onychomycosis that we found differ from those found in other countries, suggesting that the heat and humidity of the Colombian climate could favour yeast nail infections. The lowest MICs for Candida species (obtained with voriconazole, followed by itraconazole) may be explained by emerging resistant strains. Against dermatophytes, the lowest MICs were obtained with terbinafine, followed by voriconazole. MIC values for the evaluated agents were higher for non-dermatophyte filamentous fungi than for other fungi. As MIC breakpoints have not yet been established for onychomycosis therapies, it remains unclear if in vitro activities of antifungal drugs are predictive of clinical outcome. Well-designed clinical studies are necessary to assist clinicians in choosing the best antifungal agents. PMID- 19874355 TI - Usefulness of the CD63 basophil activation test in detecting Anisakis hypersensitivity in patients with chronic urticaria: diagnosis and follow-up. AB - BACKGROUND: The basophil activation test (BAT) has been recently described as a useful in vitro tool for diagnosis of allergy to Anisakis species in patients with acute urticaria. AIM: To evaluate the relationship between sensitization to Anisakis simplex and chronic urticaria (CU), using flow cytometry analysis of in vitro BAT. Methods. A. simplex sensitization was evaluated in patients with CU (n = 57) and in atopic (n = 22) and healthy controls (n = 20) by means of skin prick test (SPT), specific IgE and Anisakis-induced BAT using a triple-labelled strategy with anti-CD123, anti-human leucocyte antigen DR and anti-CD63 antibodies. During a follow-up period of 6 months in 10 patients with CU who accepted a fish-free dietary regimen, the diagnostic performance of the in vivo and in vitro methods was calculated, and changes in specific IgE and BAT were evaluated with respect to clinical response. RESULTS: A significant association between CU and A. simplex sensitization was found, with an overall prevalence of 75.4% in patients with CU (43/57) compared with 18% (4/22) and 10% (2/20) of the atopic and healthy controls, respectively (P < 0.0001). BAT (cut-off > 13%) had the highest sensitivity and specificity, with significantly better ability than specific IgE testing for the identification of A. simplex sensitization in patients with CU. During the 6-month follow-up, clinical improvement was seen in all patients, and specific IgE and BAT results decreased to normal values in 6/10 (60%) and 10/10 (100%) patients, respectively. CONCLUSIONS: BAT can be considered a reliable new in vitro method to evaluate A. simplex hypersensitivity in patients with CU, supplementing standardized procedures in both diagnosis and follow-up. PMID- 19874356 TI - Colorimetric measurements of iris colour and their significance in East Asian patients with skin cancer. AB - BACKGROUND: A light-coloured iris is considered a risk factor for skin cancer in general. However, iris colour cannot be considered a plausible risk factor for skin cancer in East Asian populations because of the relative homogeneity of iris colours. Furthermore, subjective classifications of iris colour cannot distinguish between different East Asian individuals as to their likelihood of developing cancer. AIM: To measure human iris colours quantitatively and to assess the significances of iris colours with respect to skin cancer in Korean patients. METHODS: Reference Commission Internationale d'Eclairage (CIE) L*a*b* coordinates on a ColorCheck chart were recorded using a reflectance spectrophotometer and compared with computed CIE L*a*b* coordinates from digital images to determine equations to calibrate CIE L*a*b* values. We then took iris images and measured iris colours and the colours of sun-exposed and sun-protected skin in 42 Korean patients with various cutaneous malignancies and nonmalignant dermatological diseases. Results were statistically analysed with regard to iris and skin colours in CIE L*a*b* coordinates. RESULTS: Patients with skin cancer had significantly lighter irises or higher L* values than dermatological patients without a malignancy (P = 0.02). Colour differences (DeltaE*ab) between sun exposed skin and sun-protected skin were greater in men (P < 0.01) and in patients with skin cancer (P < 0.01), and the lightness (L*) values of sun exposed skins decreased with age (r = -0.32, P < 0.05). CONCLUSIONS: Iris colour appears to be a possible skin cancer risk factor in East Asian populations. The larger colour differences seen between sun-protected and sun-exposed skin in men and in patients with skin cancer may have been due to chronic or excessive sun exposure. PMID- 19874357 TI - Serum interleukin-27 levels in patients with cutaneous T-cell lymphoma. PMID- 19874358 TI - Management of acne vulgaris: an evidence-based update. AB - This review summarizes clinically important findings from 3 systematic reviews, 1 updated guideline and a selection from the 62 randomized controlled trials (RCTs) published between February 2007 and January 2009 on the topic of acne vulgaris. Low glycaemic-load diets might reduce acne severity but this remains unproven. Written patient information leaflets have not been surpassed by other communication methods. New combination topical treatments have not shown convincing advantages over current combination products such as clindamycin/benzoyl peroxide. Topical dapsone is superior to placebo but has yet to be compared with standard topical treatments. Long-term topical tretinoin to prevent nonmelanoma skin cancer in elderly men was associated with higher all cause mortality, but there is currently no evidence of increased mortality for topical retinoid use when treating acne. All oral tetracyclines have similar efficacy, yet minocycline is the most costly. Oral isotretinoin monotherapy remains the gold-standard treatment for severe acne. Flutamide plus the oral contraceptive pill is beneficial for acne associated with polycystic ovary syndrome. Photodynamic therapy, phototherapy and laser therapy cannot be recommended universally for acne until minimal postinflammatory pigmentation and longer-term benefit can be shown, especially with current high costs. Development of non-antibiotic therapies is preferable to minimize the risk of community antibiotic resistance. Future trials should use active comparators at optimum doses and avoid noninferiority comparisons unless appropriately powered. Trials need to shift from using multiple, unvalidated outcome measures to including patient-reported and quality-of-life outcomes, and all trials should be registered on a public clinical-trials database. PMID- 19874359 TI - An approach to the correlation between vitiligo and autoimmune thyroiditis in Chinese children. AB - BACKGROUND: Vitiligo is a common skin depigmenting disease, which is thought to have, at least partly, an autoimmune aetiology. AIM: To explore the correlation between paediatric vitiligo and other associated diseases, with an emphasis on autoimmune thyroiditis (AT). METHODS: In total, 363 paediatric patients (198 boys, 165 girls) with vitiligo and 93 healthy children (55 boys, 38 girls) were screened for autoimmune thyroiditis. The two groups were matched for age and gender. Children with vitiligo were split into two groups according to type (segmental and nonsegmental vitiligo). Demographic data, clinical features and examinations were recorded using questionnaires. Thyroid function tests including free triiodothyronine, free thyroxine and thyroid-stimulating hormone were performed. Anti-thyroid peroxidase antibody) and anti-thyroglobulin antibody levels were assessed as well. Other associated diseases were also monitored in this study. RESULTS: Of the 363 patients, 43 (11.8%) had abnormal levels of studied thyroid parameters, compared with 4 of the 93 controls (4.3%); the difference was significant (P = 0.04). The alterations of thyroid parameters and the incidence of AT in patients with nonsegmental vitiligo were both significantly different (P < 0.05, P = 0.04) relative to the segmental vitiligo group. Of the 363 patients, 67 (18.5%) had other associated diseases. There were no differences in the rates of other associated diseases between patients with segmental vitiligo and those with nonsegmental vitiligo (P > 0.05). CONCLUSIONS: A significant incidence of thyroid dysfunction was found in paediatric patients with nonsegmental vitiligo. As vitiligo usually appears before the development of the thyroid disease, it may be advantageous to screen thyroid functions and antibody levels in all paediatric patients with vitiligo, especially those with nonsegmental vitiligo. PMID- 19874360 TI - Severe exacerbation of multiple self-healing squamous epithelioma (Ferguson-Smith disease) with radiotherapy, which was successfully treated with acitretin. AB - We describe the challenging case of a patient presenting with extensive, eruptive mid-facial squamous cell carcinomas (SCCs) and keratoacanthomas (KAs) consequent to radiotherapy. Our patient had a personal and family history of multiple KAs and SCCs. Multiple self-healing squamous epithelioma, otherwise known as Ferguson Smith disease, was diagnosed. This case presented a therapeutic challenge to preserve tissue and avoid severe facial disfigurement. We found oral acitretin to be the treatment of choice. PMID- 19874361 TI - c-Kit (CD117) expression in classic Kaposi's sarcoma. AB - BACKGROUND: Kaposi's sarcoma is a multicentric, low-grade, vascular neoplasia. Human herpesvirus 8 is associated with all epidemiological forms of KS and has been shown in vitro to induce the tyrosine receptor kinase c-Kit in infected cells. AIM: To investigate the expression of c-Kit in cases of classic KS and to clarify its association with clinicopathological parameters and HHV8 latency associated nuclear antigen-1 expression. METHODS: In total, 35 cases of classic KS at various histological stages were included in the study. Age and gender of the patients and location and histological stage of the tumours were recorded. Formalin-fixed, paraffin wax-embedded tissue sections were stained by immunohistochemistry with antibodies to c-Kit and HHV8. RESULTS: c-Kit immunoreactivity was found in 22 cases and HHV8 immunoreactivity was present in all cases. There was no correlation in c-Kit immunoreactivity between clinicopathological parameters and HHV8 immunoreactivity. CONCLUSIONS: The results of our study show that in cases of classic KS there is a high rate of c Kit immunoreactivity, but c-Kit expression does not show any correlation with HHV8 immunoreactivity. PMID- 19874362 TI - Photochemotherapy for systemic sclerosis: effect on clinical and molecular markers. AB - BACKGROUND: The cutaneous changes seen in systemic sclerosis (SSc) can result in considerable patient morbidity. AIM: We previously reported on the beneficial effect of psoralen ultraviolet A (PUVA) phototherapy in 13 patients with morphoea. We now report the findings of a study in which patients with SSc were treated with PUVA. METHODS: Twelve patients with SSc were treated with PUVA phototherapy. The effect on cutaneous disease activity was assessed using the modified Rodnan score, and the effect on serological and immunohistochemical growth factors and adhesion molecules was also measured. RESULTS: The median Rodnan score at baseline was 24.5 [interquartile range (IQR) 18.5-26.0]. The median number of treatments with PUVA was 24 exposures (IQR 20-26) with a median cumulative exposure of 68.3 J/cm(2) (IQR 28.6-139.8). Of the 12 patients, 11 responded well to phototherapy with a mean change in Rodnan score of 6.58 (36.98%) (P < 0.01, Wilcoxon signed ranks test). After treatment with PUVA there was a significant increase in circulating tumour necrosis factor-alpha levels in 8/12 patients (P = 0.03). In 7/12 patients there was an increase in E-selectin and vascular cell adhesion molecule, although this was not significant. CONCLUSIONS: PUVA treatment is associated with a significant improvement in cutaneous symptoms in patients with SSc as measured by the Rodnan score (P < 0.01). Specific lymphocyte markers, adhesion molecules and cytokines are also affected by this treatment, helping to clarify further the mechanism of action of PUVA treatment and our understanding of the primary pathological process. PMID- 19874363 TI - Extraocular sebaceous carcinoma expressing oestrogen receptor alpha and human epidermal growth factor receptor 2. PMID- 19874364 TI - Keratotic vascular papules over the feet: a case of Waldenstrom's macroglobulinaemia-associated cutaneous macroglobulinosis. AB - Waldenstrom's macroglobulinaemia (WM) is a plasma-cell dyscrasia characterized by the monoclonal proliferation of lymphoplasmacytes. A 48-year-old man presented with a 4-year history of multiple painful, hyperkeratotic deep-seated papules over the pressure areas of both soles. He had a 1-year history of Raynaud's phenomenon, intermittent epistaxis, recurrent vomiting, tingling and numbness, and visual disturbances. Histological examination of a skin biopsy found amyloid like deposits in the upper and mid dermis involving dermal blood vessels, but apart from periodic-acid-Schiff, various stains gave negative results for amyloid. Direct immunofluorescence was positive for IgM antibody. Hence, a diagnosis of WM with cutaneous macroglobulinosis was made. Immunoelectrophoresis found monoclonal IgM kappa antibody, and bone-marrow examination revealed a lymphoplasmacytoid malignancy. The patient's systemic systems were attributed to hyperviscosity syndrome associated with WM and the cutaneous papules were identified as deposits of excess IgM antibodies. The patient received five cycles of chemotherapy, resulting in nearly complete resolution of the skin lesions and systemic symptoms. PMID- 19874365 TI - Inhibitory effects of antipsychotic and anxiolytic agents on stress-induced degranulation of mouse dermal mast cells. AB - BACKGROUND: Various psychological stresses induce degranulation of mast cells. It has been confirmed by animal experiments that stress induced by restraint promotes mast-cell degranulation in various organs, and that the degranulation is inhibited by pretreatment with corticotropin-releasing factor (CRF)-neutralizing antibodies, CRF receptor antagonists, and neurotensin (NT) antagonists. Previous studies have suggested that anxiety and fear induced in animals by psychological stressors promote the production and release of various neuropeptides and neurotransmitters, and induce degranulation of mast cells in several organs. AIM: To evaluate the effect of prior treatment with antipsychotic and anxiolytic agents to inhibit foot-shock (FS) stress-induced degranulation of mouse dermal mast cells. METHODS: Using a communication box system, FS was administered to mice and the degranulated dermal mast cells were counted. Chlorpromazine (2 or 4 mg/kg body weight), tandospirone (10 mg/kg body weight) or CRA1000, a selective non-peptidic CRF receptor type 1 antagonist (10 or 100 mg/kg body weight) was injected intraperitoneally 1 h before exposure to FS. RESULTS: After FS was administered, the number of dermal mast cells did not change. However, FS significantly increased the proportion of degranulated mast cells. Pretreatment of mice with chlorpromazine hydrochloride, an antipsychotic agent (2 or 4 mg/kg), or the anxiolytic agents tandospirone citrate (10 mg/kg) or CRA1000 (10 or 100 mg/kg), significantly inhibited the FS-induced mast-cell degranulation (P < 0.05, P < 0.01, P < 0.05, P < 0.05, and P < 0.05, respectively). CONCLUSIONS: Antipsychotic and anxiolytic agents may be effective treatments for stress aggravated inflammatory skin diseases by inhibition of mast-cell degranulation. PMID- 19874366 TI - Increased serum B cell-activating factor level in children with atopic dermatitis. AB - BACKGROUND: B cell-activating factor (BAFF) is a tumour necrosis factor superfamily member best known for its role in the survival and maturation of B cells. BAFF activity is seen in naive and effector/memory T cells. AIM: To investigate the level and role of BAFF in serum of patients with atopic dermatitis (AD). METHODS: Levels of serum BAFF, a proliferation-inducing ligand (APRIL) and total serum IgE level, and total eosinophil count were measured in 245 children. RESULTS: Patients were characterized as having atopic eczema (AE) (n = 90) or non-AE (n = 77); the remainder were healthy control subjects (n = 78). Serum BAFF level in children with AE (1625.04 +/- 708.32 pg/mL) was significantly higher than in non-AE children (1194.69 +/- 448.44 pg/mL, P < 0.0001) or healthy controls (1062.89 +/- 444.74 pg/mL, P < 0.0001). Serum APRIL level was not different between the three groups. Serum BAFF level significantly correlated with total serum IgE level (gamma = 0.42, P < 0.0001) and total eosinophil count. It was also positively correlated with serum BAFF and egg specific IgE level (gamma = 0.252, P = 0.045) in AE. CONCLUSIONS: Serum BAFF level is high in AE and might be a useful marker for AE. PMID- 19874367 TI - Simple and rapid screening for HLA-Cw*06 in Polish patients with psoriasis. AB - BACKGROUND: The human leucocyte antigen (HLA) C allele Cw*06 is currently recognized as a major disease allele at the PSORS1 locus. It has been suggested that characterization of this gene could be used as a convenient criterion for classification of psoriasis phenotypes. AIM: To design and optimize a DNA typing procedure, suitable for identification of HLA-Cw*06 and its zygosity status verification in large-scale analyses, and to test for its robustness in a case control study. METHODS: PCR assays with sequence-specific primers (PCR-SSP) were used for specific detection of HLA-Cw*06. PCR with analysis of restriction fragment length polymorphism was used to distinguish between patients homozygous and heterozygous for HLA-Cw*06. Additionally, those homozygous for HLA-Cw*06 were screened for nonspecific digestion by degenerated PCR-SSP. This three-step procedure was used in the examination of 383 patients with psoriasis that developed at the age of >or= 30 years of age and of 143 healthy subjects from northern Poland. RESULTS: A simple and rapid procedure for screening of HLA-Cw*06 was produced. A significant difference in HLA-Cw*06 frequency between patients with psoriasis and controls was seen (P = 0.02). Detailed examination of the age of disease onset among patients with psoriasis revealed that involvement of HLA Cw*06 in the genetic background of psoriasis developing as late as the age of 45 years cannot be neglected. CONCLUSIONS: The low cost, high-throughput capacity and requirement for small sample amounts make this procedure a useful one for HLA Cw*06 typing in clinical practice and large population studies. We recommend that patients with psoriasis diagnosed before 45 years of age should be considered for diagnostic HLA-Cw*06 typing. PMID- 19874368 TI - RNA interference silences the human papillomavirus 6b/11 early gene E7 in vitro and in vivo. AB - BACKGROUND: RNA interference (RNAi) is a potential therapeutic tool in the treatment of various diseases, such as cancers and viral infections. Silencing of E7 genes is an effective method to suppress human papilloma virus (HPV)-related tumours. AIM: To determine the therapeutic potential of RNAi in controlling condyloma acuminatum (CA). METHODS: Small interfering (si)RNA duplexes or small hairpin (sh)RNA-expressing plasmids targeting the E7 genes of HPV-6b or HPV 11were inoculated into cultured E7-expressing cells via cationic liposomes, or into E7 gene-expressing mouse tumour models intratumorally or intravenously. Experiments were performed in triplicate and E7 mRNA level was analysed by real time PCR. RESULTS: The in vitro experiments found that both siRNAs and shRNA expressing plasmids reduced the mRNA levels of HPV-6b or HPV-11 E7 to 20-40% at the optimum dosage of 25-50 nmol/L for siRNAs and 0.1-0.2 microg/mL for shRNA expressing vectors. The optimum time for this to happen was 72 h. E7 mRNA expression in tumour models was reduced to 45-50% after three intratumural injections. Intratumoral injections of RNAi effectors induced greater inhibition than did intravenous injections. CONCLUSIONS: We conclude that HPV-6b/11 E7 gene expression can be specifically modulated by RNAi, which may provide a useful method in the management of CA. PMID- 19874369 TI - Nonpigmenting fixed drug eruption as a possible abortive variant of toxic epidermal necrolysis: immunohistochemical and serum cytokine analyses. AB - Nonpigmenting fixed drug eruption (NPFDE) is clinically indistinguishable from Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) in its initial presentation. The traditional paradigm that epidermal changes are absent in NPFDE cannot be easily reconciled with the clinical resemblance to SJS/TEN. We therefore investigated whether NPFDE is pathogenetically different from pigmented FDE (PFDE) or SJS/TEN and which factors are responsible for the lack of hyperpigmentation. NPFDE lesions before challenge were characterized by larger numbers of CD8+ intraepidermal T cells associated with a paucity of melanocytes, compared with those in PFDE. Very high levels of serum interleukin (IL)-10 were noted after clinical challenge. We conclude that NPFDE is a clinical syndrome with heterogeneous histological expression. NPFDE with epidermal involvement may be an abortive form of SJS/TEN, in which progression to TEN can be prevented by IL-10. PMID- 19874370 TI - Immune reconstitution inflammatory syndrome involving the skin. AB - BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) occurs in 10-25% of unselected patients starting highly active antiretroviral therapy (HAART). About 52-78% of these cases involve cutaneous features. AIM: To describe the prevalence and incidence of new dermatological conditions within 6 months of patients starting HAART, and to specify the clinical and immunological features and time of onset in patients responding to HAART. METHODS: A retrospective cohort analysis was performed of 59 treatment-naive patients started on HAART and followed up for 6 months by a clinician trained in dermatology. Medical records were reviewed for new dermatological conditions diagnosed clinically. RESULTS: In all, 30 patients (50.8%) developed 45 new skin conditions at a median of 8 weeks (range 3-24 weeks) after starting HAART. The incidence rate was 104.5 cases per 100 patient-years. Diagnoses included seborrhoeic dermatitis (nine patients), anogenital herpes (seven patients), acne, tinea and folliculitis (six patients each), Kaposi's sarcoma, herpes zoster, genital warts and eczema (two patients each), and molluscum contagiosum, planar warts and pityriasis versicolor (one patient each). Significantly more women (23/38; 60.5%) than men (7/21; 33.3%) (P < 0.05) developed new skin lesions after starting HAART. Baseline median CD4 counts in those with and without IRIS were 60/microL and 62/microL, respectively, and in both groups, the counts increased to > 90/microL by week 12. Baseline median viral load was > 100,000 copies/mL and was < or = 32 copies/mL by week 12. In both groups, the majority of patients were in World Health Organization stages 3 and 4. CONCLUSIONS: New skin lesions were very common in this cohort, with the majority being women and patients with very low baseline CD4 counts. PMID- 19874371 TI - Macrophage migration inhibitory factor in patients with vitiligo and relationship between duration and clinical type of disease. AB - BACKGROUND: Vitiligo is a disorder of pigmentation characterized by the presence of depigmented skin macules. Cellular immunity is known to have a role in the pathogenesis of vitiligo. Macrophage migration inhibitory factor (MIF) is a potent activator of macrophages and is considered to play an important role in cell-mediated immunity. AIMS: To determine serum level of MIF in patients with vitiligo and compare with healthy controls. We also aimed to determine whether there is a relationship between MIF levels and the disease duration, clinical vitiligo and involved body surface area (BSA) in patients with vitiligo. METHODS: The study group comprised 30 patients with vitiligo (14 men, 16 women) and 30 healthy controls, matched for age and gender. Blood samples were taken for MIF analysis. RESULTS: The mean serum level of MIF in patients with vitiligo (40.83 +/- 31.66 pg/mL) was significantly higher than that of the control group (21.00 +/- 6.48 pg/mL) (P = 0.002). There was a positive correlation between disease duration and MIF levels (r = 0.601, P < 0.001). Mean MIF level of patients with acral and acrofacial vitiligo (n = 6) was 48.25 +/- 32.02 pg/mL, and of patients generalized vitiligo (n = 18) was 44.46 +/- 35.25 pg/mL. There was no significant difference between these two groups (P > 0.05). However there was a significant difference in MIF levels between patients with localized (20.41 +/- 5.23, n = 5) and acral-acrofacial (P = 0.02) vitiligo and those with generalized (P = 0.006) vitiligo. There was no relationship between BSA and MIF levels. CONCLUSIONS: Mean serum MIF level of patients with vitiligo was higher than that of controls, indicating that MIF has a role in the pathogenesis of vitiligo. PMID- 19874372 TI - Deregulation of cell-death pathways as the cornerstone of skin diseases. AB - Deregulation of cell-death pathways plays a key role in the pathogenesis of various skin diseases. The different types of cell death are mainly defined by morphological criteria, and include apoptosis, autophagic cell death, and necrosis. The process of apoptosis is well characterized at the molecular level and involves the activation of two main pathways, the intrinsic and extrinsic pathways, converging into the execution of apoptosis by intracellular cysteine proteases, called caspases. The relevance and implication of these apoptotic pathways in the pathophysiology of skin diseases, such as toxic epidermal necrolysis, graft-versus-host disease and skin cancer, has been extensively studied. The role of autophagic cell death in progression of skin tumours and response to cytotoxic drugs is only beginning to be elucidated. PMID- 19874373 TI - Lichen planus in childhood: report of 100 cases. AB - BACKGROUND: Lichen planus (LP) is uncommon in children, and there have been few large studies on LP in this patient group. Most of the literature on childhood LP has appeared as case reports or isolated case series. METHODS: We report the results of a study on 100 children with LP, which is, to our knowledge, the largest study to date on this condition. RESULTS: The mean age of patients was 8.76 years and mean age at disease onset was 7.6 years. The onset of the disease was most commonly seen on the legs (54% of patients). The classic papular lesions were the commonest morphology seen (42% of patients). The oral mucosa was involved in 17% and nail involvement in 19% of children. CONCLUSION: Vaccination against hepatitis B has been suggested to be causally related to the onset of LP in various published studies. However, only 16 of our patients had been vaccinated against hepatitis B. If there is a causal relationship, more cases of LP in children may occur in the future, as vaccination against hepatitis B becomes routine in India. PMID- 19874374 TI - Do antineutrophil cytoplasmic antibodies (ANCA) play a key role in neutrophilic dermatoses? A case of propylthiouracil-induced neutrophilic dermatosis with positive perinuclear ANCA. AB - We report a case of neutrophilic dermatosis caused by propylthiouracil (PTU), with positive perinuclear antineutrophil cytoplasmic antibodies (p-ANCA). PTU is well known to cause vasculitis associated with positive ANCA titres, and this typically occurs late in the treatment (after months to years). PTU rarely causes neutrophilic dermatoses (three case reports). In the three cases described, ANCA was positive at the outset. Our patient's initial ANCA testing was negative and her positive p-ANCA evolved. This may be because PTU binds to myeloperoxidase (MPO) inside neutrophils, altering its configuration and thus causing antibody formation to this abnormal MPO-PTU configuration, which would not be detected by standard laboratory techniques. ANCA has been implicated in spreading neutrophil activation and thus its pathogenic effect and clinical significance may extend beyond the realm of vasculitis alone. PMID- 19874375 TI - Demethylation of promoter regulatory elements contributes to CD70 overexpression in CD4+ T cells from patients with subacute cutaneous lupus erythematosus. AB - BACKGROUND: Impaired methylation of T-cell DNA is thought to contribute to the development of systemic lupus erythematosus (SLE). CD70 (TNFSF7) is a B-cell costimulatory molecule that contributes to excessive B-cell stimulation in vitro and in vivo. CD70 is overexpressed in CD4+ T cells of patients with SLE, and DNA demethylation occurs in promoter sequences that regulate CD70 expression in SLE CD4+ T cells. However, it is unknown whether the expression and methylation of CD70 in CD4+ T cells are affected in patients with subacute cutaneous lupus erythematosus (SCLE). OBJECTIVE: To compare CD70 expression levels and the methylation status of the CD70 promoter region in CD4+ T cells from patients with SCLE and healthy controls. METHODS: We used real-time RT-PCR to compare messenger RNA levels of CD70 and flow cytometry to compare CD70 protein levels in CD4+ T cells from patients with SCLE and healthy controls. Bisulphite sequencing was used to determine the methylation status of the CD70 promoter region. RESULTS: CD70 is overexpressed at the surface of SCLE CD4+ T cells. Demethylation of the CD70 promoter region was seen in CD4+ T cells from patients with SCLE. CONCLUSIONS: Demethylation of regulatory elements contributes to CD70 overexpression in CD4+ T cells of patients with SCLE. PMID- 19874376 TI - Topical tazarotene vs. coal tar in stable plaque psoriasis. AB - BACKGROUND: The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. AIM: To assess the comparative efficacy and tolerability of topical tazarotene 0.1% gel and CCT 5% ointment in stable plaque psoriasis. METHODS: In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). RESULTS: Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% +/- 9.43 and 77.37% +/- 10.93 with tazarotene and CCT, respectively (P > 0.05). A reduction in ESI score of > 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. CONCLUSIONS: Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis. PMID- 19874377 TI - Prevalence of acquired melanocytic naevi in Brazilian schoolchildren. AB - BACKGROUND: The prevalence of acquired melanocytic naevi (AMN) is one of the most important known risk factors for malignant melanoma (MM) in homogeneous white populations. However, there are few studies on AMN in heterogeneous populations. Insight into the causes of AMN in heterogeneous populations in a country with intense ultraviolet radiation should lead to successful strategies in the prevention of MM. AIM: To evaluate the frequency and anatomical distribution of AMN and to observe the influence of environmental and constitutional variables. METHODS: A cross-sectional study on the prevalence of AMN was performed on 1279 Brazilian schoolchildren, aged 2-8 years, according to an international protocol. RESULTS: Both girls and boys had the same number of AMN. The number of AMN was higher on sun-exposed body sites, such as shoulders, thorax/upper abdomen, face/ears and back. A high number of AMN was associated with lighter skin type, greater sun exposure, age, number of sunburns and presence of freckles. CONCLUSIONS: In genetically predisposed people, the body-site distribution of AMN in a heterogeneous population (mixed ethnic backgrounds) is similar to that in a homogeneous population and has the same tendency toward potential proliferation of melanocytes in the presence of ultraviolet radiation. Strategies to reduce the incidence of MM should start at an early age. We believe that these findings will have a direct effect on concepts for preventive strategies. Studies in different populations may serve as a starting point for research into the mechanism underlying increasing rates of AMN. PMID- 19874378 TI - Infectious causes of cancer: an evolving educational saga. PMID- 19874379 TI - Hepatitis B and C virus-related carcinogenesis. AB - Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the most important causes of hepatocellular carcinoma (HCC), accounting for the majority of the cases worldwide. The geographical distribution of HCC therefore coincides with the distribution of HBV and HCV infections in those areas. Similar to nonviral liver diseases, HBV and HCV infection can cause chronic injury to the liver, with subsequent progression to severe fibrosis and cirrhosis. The presence of cirrhosis is a major risk factor for the development of HCC. However, HCC can occur in the absence of cirrhosis, suggesting that both HBV and HCV may be directly involved in hepatocarcinogenesis. Several HBV factors have been implicated in hepatocarcinogenesis, including the HBx gene, the pre-S2/S gene and the HBV spliced protein. Furthermore, HBV can be integrated into the host genome, leading to changes in genomic function or chromosomal instability. By contrast to HBV, HCV cannot integrate into the host genome. Various HCV proteins, including the core, envelope and nonstructural proteins, have been shown to have oncogenic properties. For HBV infection, antiviral therapy and vaccination have been shown to decrease the risk of HCC. Antiviral therapy for HCV can also reduce the risk of HCC. PMID- 19874380 TI - Helicobacter pylori and gastric adenocarcinoma. AB - Gastric cancer is the second most common cause of cancer death worldwide. A large body of evidence supports a causal role of Helicobacter pylori in the majority of gastric malignancies. Great strides have been made in understanding the pathogenesis of this relationship, but much remains to be learned. Moreover, because of the high prevalence of infection, the lack of definitive trials, and the challenges of H. pylori treatment, there remains no consensus on the role of routine screening and treatment of this infection to prevent cancer. This article reviews the current knowledge on H. pylori and gastric cancer and presents some of the clinical and public health challenges associated with this pathogen. PMID- 19874381 TI - Human papilloma viruses and cancer in the post-vaccine era. AB - Human papilloma viruses (HPV) are strong human carcinogens, in fact today they are considered as the second most frequent carcinogen. In the middle of the 1970s the hypothesis that cervical cancer may arise from viruses was established and in the 1990s the relationship between HPV and cervical neoplasia was confirmed. HPV infections are the most common sexually transmitted infections. Specific subtypes of human papilomaviruses are now considered as the etiological agents in nearly all cases of cervical cancer and cervical epithelial neoplasia. Approximately 470,000 new cases and 23,000 deaths of cervical cancer occur each year, with the majority taking place in developing countries. Cervical cancer remains among the three leading causes of cancer deaths among women below the age of 45. Human papilomaviruses are classified into two groups: high-risk (oncogenic) types and low risk types. HPV types 16, 18, 45 and 31 are considered to be the most important oncogenic types. Subtypes 16 and 18 are the causative agents of more than 50% of cervical pre-cancerous lesions, and more than 70% of cervical cancer cases. High risk subtypes are also implicated with anal, perianal and oropharyngeal carcinomas. Recently, the prophylactic bivalent HPV 16/18 and the quadrivalent HPV 6/11/16/18/ vaccines have been approved. The development of prophylactic vaccines against human papilomavirus has been hailed as one of the most significant advances of recent years and it is expected to reduce dramatically the mortality of human papilomavirus associated cancers, but has also given rise to some of the most intense scientific debates. PMID- 19874382 TI - Epstein-Barr virus and carcinogenesis: beyond Burkitt's lymphoma. AB - Subsequent to its discovery over 45 years ago, Epstein-Barr virus (EBV) has been associated with numerous human carcinomas. Approximately 95% of the world's population sustain an asymptomatic life-long EBV infection. EBV persists in the memory B cell pool of normal healthy individuals and any disruption of this interaction results in virus-associated B cell tumours. The association of EBV with epithelial cell tumours, specifically nasopharyngeal carcinoma and EBV positive gastric carcinoma, is less clear and is currently considered to be a consequence of the aberrant establishment of virus latency in epithelial cells displaying pre-malignant genetic changes. Although the precise role of EBV in the carcinogenic process is currently poorly understood, the presence of the virus in all tumour cells provides opportunities for the development of novel therapeutic and diagnostic approaches. The study of EBV and its role in carcinomas continues to provide insights into the carcinogenic process that are relevant to a broader understanding of tumour pathogenesis and to the development of targeted cancer therapies. PMID- 19874383 TI - A preventable killer: Pneumonia. PMID- 19874384 TI - The costs and benefits of fast living. AB - Growth rates play a fundamental role in many areas of biology (Q. Rev. Biol., 67, 1992, 283; Life History Invariants. Some Explorations of Symmetry in Evolutionary Biology, 1993; Philos. Trans. R. Soc. Lond. B Biol. Sci., 351, 1996, 1341; Plant Strategies, Vegetation Processes, and Ecosystem Properties, 2002; Trends Ecol. Evol., 18, 2003, 471; Q. Rev. Biol., 78, 2003, 23; J. Ecol., 95, 2007, 926.) but the cost and benefits of different growth rates are notoriously difficult to quantify (Q. Rev. Biol., 72, 1997, 149; Funct. Ecol., 17, 2003, 328). This is because (1) growth rate typically declines with size and yet the most widely used growth measure - relative growth rate or RGR (conventionally measured as the log of the ratio of successive sizes divided by the time interval) - is not size corrected and so confounds growth and size, (2) organisms have access to different amounts of resource and (3) it is essential to allow for the long-term benefits of larger size. Here we experimentally demonstrate delayed costs and benefits of rapid growth in seven plant species using a novel method to calculate size-corrected RGR. In control treatments, fast-growing plants benefited from increased reproduction the following year; however, fast-growing plants subjected to an experimental stress treatment (defoliation) showed strongly reduced survival and reproduction the following year. Importantly, when growth was estimated using the classical RGR measure, no costs or benefits were found. These results support the idea that life-history trade-offs have a dominant role in life-history and ecological theory and that the widespread failure to detect them is partly due to methodological shortcomings. PMID- 19874385 TI - The rise of research on futures in ecology: rebalancing scenarios and predictions. AB - Concern about the ecological consequences of global change has increasingly stimulated ecologists to examine the futures of ecological systems. Studying futures is not only a crucial element of the interaction between science, management and decision making, but also a critical research challenge per se, especially because futures cannot be observed or experimented on. In addition, researchers can encounter methodological and theoretical difficulties, which make interpretations and predictions problematic. In the literature which deals with futures of ecological systems two main lines of research can be distinguished: a predictive approach, which dominates the literature, can be contrasted with a rarer number of studies that elaborate potential scenarios for ecological systems. Scenario approaches currently concern mainly contacts with stakeholders or decision makers, or the use of climate scenarios to derive projections about ecological futures. We argue that a new direction for ecological futures research could be explored by using ecological scenarios in combination with predictive models to further fundamental ecological research, in addition to enhancing its applied value. PMID- 19874386 TI - Angelman syndrome: current understanding and research prospects. AB - Angelman syndrome is a neurogenetic disorder characterized by developmental delay, severe intellectual disability, absent speech, exuberant behavior with happy demeanor, motor impairment, and epilepsy, due to deficient UBE3A gene expression that may be caused by various abnormalities of chromosome 15. Recent findings in animal models demonstrated altered dendritic spine formation as well as both synaptic [including gamma-aminobutyric acid (GABA)(A) and N-methyl-D aspartate (NMDA) transmission] and nonsynaptic (including gap junction) influences in various brain regions, including hippocampus and cerebellar cortex. Reversal of selected abnormalities in rescue genetically engineered animal models is encouraging, although it should not be misinterpreted as promising "cure" for affected patients. Much research is still required to fully understand the functional links between lack of UBE3A expression and clinical manifestations of Angelman syndrome. Studies of regulation of UBE3A expression, including imprinting-related methylation, may point to possibilities of therapeutic upregulation. Understanding relevant roles of the gene product might lead to targeted intervention. Further documentation of brain network dynamics, with particular emphasis on hippocampus, thalamocortical, and cerebellar networks is needed, including in a developmental perspective. There is also a need for further clinical research for improving management of problems such as epilepsy, behavior, communication, learning, motor impairment, and sleep disturbances. PMID- 19874387 TI - Array-CGH detection of a de novo 0.7-Mb deletion in 19p13.13 including CACNA1A associated with mental retardation and epilepsy with infantile spasms. PMID- 19874388 TI - Familial hemiplegic migraine is associated with febrile seizures in an FHM2 family with a novel de novo ATP1A2 mutation. PMID- 19874391 TI - Saliva DHEA and cortisol responses following short-term corticosteroid intake. AB - BACKGROUND: Given the high correlation between the serum and saliva hormone values demonstrated at rest, saliva provides a convenient non-invasive way to determine dehydroepiandrosterone (DHEA) and cortisol concentrations. However, to our knowledge, pituitary adrenal recovery following short-term suppression with corticosteroids has never been investigated in saliva. The aim of this study was therefore to examine how steroid hormone concentrations in saliva are influenced by short-term corticosteroid administration. MATERIALS AND METHODS: We studied saliva DHEA and cortisol concentrations before, during (day 1-day 7) and following (day 8-day 16) the administration of oral therapeutic doses of prednisone (50 mg daily for 1 week) in 11 healthy recreationally trained women. RESULTS: Mean saliva DHEA and cortisol concentrations decreased immediately after the start of prednisone treatment (P < 0.05). Three days after concluding prednisone administration, both saliva DHEA and cortisol had returned to pretreatment levels. CONCLUSIONS: These data are consistent with previous studies on blood samples and suggest that non-invasive saliva samples may offer a practical approach to assessing pituitary-adrenal function continuously during and after short-term corticosteroid therapy. PMID- 19874395 TI - Memantine versus donepezil in mild to moderate Alzheimer's disease: a randomized trial with magnetic resonance spectroscopy. AB - BACKGROUND AND PURPOSE: To compare memantine with the most prescribed cholinesterase inhibitor (donepezil) from a clinical viewpoint when administered in early phases of Alzheimer disease (AD), and to find out whether memantine may produce changes in brain metabolite concentrations in comparison with donepezil. METHODS: In this comparative rater-blinded parallel group randomized trial we recruited a consecutive sample of patients with probable mild to moderate AD. At baseline we carried out neuropsychological assessment with mini-mental, Clinical Dementia Rating Scale (CDR), Blessed Dementia Rating Scale, Alzheimer's Disease Assessment Scale, cognitive part (ADAS-cog), neuropsychiatric inventory (NPI), and disability assessment for dementia (DAD), as well as (1)H magnetic resonance spectroscopy (MRS) in several areas of the brain. Patients were randomized to receive either donepezil or memantine for 6 months. After this elapse of time we repeated the same procedures and observed the changes in clinical scales (ADAS cog, NPI, DAD), as well as the changes in metabolite levels in every area of exploration (temporal, pre-frontal, posterior cingulated (PCG), and occipital), especially those of N-acetyl-aspartate (NAA) which is regarded as a surrogate marker of neuronal density. RESULTS: A total of sixty-three patients completed the trial. We did not see significant differences in clinical scales and metabolite levels between those on donepezil (n = 32) and those on memantine (n = 31). In general, more patients worsened than improved on either of the drugs. The changes in the NAA/creatine ratio in the PCG correlated significantly with the changes in the ADAS-cog (P = 0.004). CONCLUSIONS: Donepezil and memantine have similar modest clinical and spectroscopic effect on mild to moderate AD. MRS could be useful to monitor progression of the disease. PMID- 19874396 TI - Frontal-lobe mediated behavioral dysfunction in amyotrophic lateral sclerosis. AB - BACKGROUND: Cognitive impairment secondary to frontal lobe atrophy exists in 40 60% of Amyotrophic Lateral Sclerosis (ALS) cases. We aimed to determine the prevalence of frontal-lobe mediated behavioral impairment in (ALS) and to ascertain its relationship to cognitive impairment. METHODS: Two-hundred and twenty five patients diagnosed with sporadic ALS were evaluated for behavioral dysfunction using the Frontal Systems Behavior Scale (FrSBe), a validated measure used to examine frontal-lobe mediated behaviors, specifically apathy, executive dysfunction and disinhibition; a total behavior score is also provided. Additionally, a subset of patients also underwent a comprehensive neuropsychological evaluation. RESULTS: Changes in the total FrSBe scores were observed in 24.4% of the patients and 39.6% of the patients had impairment in at least one behavioral domain with symptoms of Apathy being the most common (31.1%). Cognitively impaired ALS patients had worse total (P = 0.05) and apathy scores (P < 0.01); however, behavioral dysfunction was also present in 16% of the cognitively intact patients. Half of the behaviorally intact patients exhibited cognitive impairment. Significant correlations were observed for performance on certain neuropsychological tests (Animal fluency, Block Design, Logical Memory I and Verbal Series Attention Test) and severity of behavioral dysfunction on certain FrSBe sub scores. CONCLUSIONS: Frontal-lobe mediated behavioral dysfunction appears to be common in ALS. Cognitively impaired ALS patients had greater behavioral dysfunction. Recognition of behavioral and cognitive dysfunction may assist health-care providers and care-givers recognize changes in decision-making capacity and treatment compliance of patients with ALS. PMID- 19874397 TI - Characterization and comparison of the properties of sarcoma cell lines in vitro and in vivo. AB - To expand the available tools for investigating human sarcomas, we characterized the primary properties of 22 common, uncommon, and newly characterized sarcoma cell lines representing eight different histological subtypes. Throughout the characterization process we noticed that in vitro markers and assays are poor indicators of tumorigenicity and that generated xenografts often bear little resemblance to the original histopathology. In vitro properties examined included morphology, proliferation rate, cell cycle characteristics, invasiveness, and immunohistochemical expression of p53 and phospho-AKT. In vivo properties examined included days to tumor formation in NOD/SCID mice, xenograft morphology in several locations and immunohistochemical expression of Ki67, p53 and phospho AKT. We believe that such an in depth comparison of a large cohort of sarcoma cell lines will be useful in both designing and interpreting experiments aimed at elucidating both the molecular biology and efficacy of therapeutic agents in sarcomas. However, that data generated also suggests a small set of sarcoma cell lines may be inappropriate for generalizations regarding biological behavior of specific sarcoma subtypes. Integration of functional genomics or other more sophisticated assays of cell lines may help bridge the differences in vitro and in vivo. PMID- 19874398 TI - POU6F1 is the transcription factor that might be involved in cell proliferation of clear cell adenocarcinoma of the ovary. AB - Clear cell adenocarcinoma of the ovary often shows resistance to anticancer agents. We investigated new molecules to use when developing molecular-targeting therapy for clear cell adenocarcinoma of the ovary. RMG-I cells without invasive potential and RMG-V cells with invasive potential (derived from clear cell adenocarcinoma of the ovary) were subjected to complementary deoxyribonucleic acid microarray analysis. Caveolin-1, a molecule involved in cellular motility and invasion, showed differing expression between the two cell lines. An RNA interference experiment using the published siRNA for caveolin-1 was carried out. The results showed suppression of RMG-V cell infiltration by siRNA, but proliferation of the cancer cells was also suppressed. In other words, RMG-V cell infiltration may have been suppressed simply because cell proliferation was suppressed by RNA interference. These findings suggested that POU6F1 might be a transcription factor involved in the proliferation of ovarian cancer cells. Clear cell adenocarcinoma of the ovary shows little response to standard therapy. The results of the present study suggest that the transcription factor POU6F1 could be a new molecular target for treatment of this cancer. PMID- 19874399 TI - Polymorphisms of p53 codon 72 and MDM2 promoter 309 and the risk of endometrial cancer. AB - Genetic polymorphisms of p53 and its negative regulator murine double minute 2 homolog (MDM2) have been shown to be closely associated with tumorigenesis in a variety of human cancers. In the present study, single nucleotide polymorphism (SNP) at p53 codon 72 and MDM2 promoter 309 was examined for germline DNA samples from 102 endometrial cancer cases and 95 controls using polymerase chain reaction based fragment analysis. There were no significant differences in the genotype and allele prevalence between control subjects and endometrial cancer patients for p53 codon 72. The GG genotype frequency of MDM2-SNP309 was statistically higher in endometrial cancer patients than that in normal healthy women when compared with the TG genotype (P= 0.0088). However, no statistically significant differences were found between the TT and TG or GG genotype frequencies and allele prevalence. Interestingly, the combination of the homozygous Arg/Arg genotype of p53 codon 72 and homozygous GG genotype of MDM2 SNP309 polymorphisms was significantly associated with the risk of endometrial cancer (odds ratio = 3.28, 95% confidence interval = 1.13 to 9.53, P= 0.0212). The homozygous variants of wild p53 codon 72 and mutant MDM2 promoter 309 may cooperatively increase the risk of endometrial cancer in a Japanese population. PMID- 19874400 TI - Organic compound characterization and source apportionment of indoor and outdoor quasi-ultrafine particulate matter in retirement homes of the Los Angeles Basin. AB - Quasi-ultrafine (quasi-UF) particulate matter (PM(0.25)) and its components were measured in indoor and outdoor environments at four retirement communities in Los Angeles Basin, California, as part of the Cardiovascular Health and Air Pollution Study (CHAPS). The present paper focuses on the characterization of the sources, organic constituents and indoor and outdoor relationships of quasi-UF PM. The average indoor/outdoor ratios of most of the measured polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were close to or slightly lower than 1, and the corresponding indoor-outdoor correlation coefficients (R) were always positive and, for the most part, moderately strong (median R was 0.60 for PAHs and 0.74 for hopanes and steranes). This may reflect the possible impact of outdoor sources on indoor PAHs, hopanes, and steranes. Conversely, indoor n alkanes and n-alkanoic acids were likely to be influenced by indoor sources. A chemical mass balance model was applied to both indoor and outdoor speciated chemical measurements of quasi-UF PM. Among all apportioned sources of both indoor and outdoor particles, vehicular emissions was the one contributing the most to the PM(0.25) mass concentration measured at all sites (24-47% on average). PRACTICAL IMPLICATIONS: Although people (particularly the elderly retirees of our study) generally spend most of their time indoors, a major portion of the PM(0.25) particles they are exposed to comes from outdoor mobile sources. This is important because, an earlier investigation, also conducted within the Cardiovascular Health and Air Pollution Study (CHAPS), showed that indoor-infiltrated particles from mobile sources are more strongly correlated with adverse health effects observed in the elderly subjects living in the studied retirement communities compared with other particles found indoors (Delfino et al., 2008). PMID- 19874401 TI - Residential air exchange rates in three major US metropolitan areas: results from the Relationship Among Indoor, Outdoor, and Personal Air Study 1999-2001. AB - We report approximately 500 indoor-outdoor air exchange rate (AER) calculations based on measurements conducted in residences in three US metropolitan areas in 1999-2001: Elizabeth, New Jersey; Houston, Texas; and Los Angeles County, California. Overall, a median AER across these urban areas and seasons was 0.71 air changes per hour (ACH, or per hour; n = 509) while median AERs measured in California (n = 182), New Jersey (n = 163), and Texas (n = 164) were 0.87, 0.88, and 0.47 ACH, respectively. In Texas, the measured AERs were lower in the summer cooling season (median = 0.37 ACH) than in the winter heating season (median = 0.63 ACH), likely because of the reported use of room air conditioners as Houston is typically hot and humid during the summer. The measured AERs in California were higher in summer (median = 1.13 ACH) than in winter (median = 0.61 ACH). Because the summer cooling season in Los Angeles County is less humid than in New Jersey or Texas, natural ventilation through open windows and screened doors likely increased measured AER in California study homes. In New Jersey, AER were similar across heating and cooling seasons, although the median AER was relatively lower during the spring. PRACTICAL IMPLICATIONS: Adequate ventilation or air exchange rate (AER) for an indoor environment is important for human health and comfort, and relevant to building design and energy conservation and efficiency considerations. However, residential AER data, especially measured by more accurate non-toxic tracer gas methodologies, are at present quite limited worldwide, and are insufficient to represent the variations across regions and seasons within and between homes, including apartments and condominiums in more densely populated urban areas. The present paper presents quantitative and qualitative data to characterize residential AERs in three US urban areas with different climate attributes. PMID- 19874402 TI - Review and comparison between the Wells-Riley and dose-response approaches to risk assessment of infectious respiratory diseases. AB - Infection risk assessment is very useful in understanding the transmission dynamics of infectious diseases and in predicting the risk of these diseases to the public. Quantitative infection risk assessment can provide quantitative analysis of disease transmission and the effectiveness of infection control measures. The Wells-Riley model has been extensively used for quantitative infection risk assessment of respiratory infectious diseases in indoor premises. Some newer studies have also proposed the use of dose-response models for such purpose. This study reviews and compares these two approaches to infection risk assessment of respiratory infectious diseases. The Wells-Riley model allows quick assessment and does not require interspecies extrapolation of infectivity. Dose response models can consider other disease transmission routes in addition to airborne route and can calculate the infectious source strength of an outbreak in terms of the quantity of the pathogen rather than a hypothetical unit. Spatial distribution of airborne pathogens is one of the most important factors in infection risk assessment of respiratory disease. Respiratory deposition of aerosol induces heterogeneous infectivity of intake pathogens and randomness on the intake dose, which are not being well accounted for in current risk models. Some suggestions for further development of the risk assessment models are proposed. PRACTICAL IMPLICATIONS: This review article summarizes the strengths and limitations of the Wells-Riley and the dose-response models for risk assessment of respiratory diseases. Even with many efforts by various investigators to develop and modify the risk assessment models, some limitations still persist. This review serves as a reference for further development of infection risk assessment models of respiratory diseases. The Wells-Riley model and dose-response model offer specific advantages. Risk assessors can select the approach that is suitable to their particular conditions to perform risk assessment. PMID- 19874403 TI - Pneumonia and influenza hospitalizations in elderly people with dementia. AB - OBJECTIVES: To compare the demographic and geographic patterns of pneumonia and influenza (P&I) hospitalizations in older adults with dementia with those of the U.S. population and to examine the relationship between healthcare accessibility and P&I. DESIGN: Observational study using historical medical claims from the Centers for Medicare and Medicaid Services (CMS) and CMS records supplemented with information derived from other large national sources. SETTING: Retrospective analysis of medical records uniformly collected over a 5-year period with comprehensive national coverage. PARTICIPANTS: A study population representative of more than 95% of all people aged 65 and older residing in the continental United States. MEASUREMENTS: Six million two hundred seventy-seven thousand six hundred eighty-four records of P&I between 1998 and 2002 were abstracted, and county-specific outcomes for hospitalization rates of P&I, mean length of hospital stay, and percentage of deaths occurring in a hospital setting were estimated. Associations with county-specific elderly population density, percentage of nursing home residents, median household income per capita, and rurality index were assessed. RESULTS: Rural and poor counties had the highest rate of P&I and percentage of influenza. Patients with dementia had a lower frequency of influenza diagnosis, a shorter length of hospital stay, and 1.5 times as high a rate of death as the national average. CONCLUSION: The results suggest strong disparities in healthcare practices in rural locations and vulnerable populations; infrastructure, proximity, and access to healthcare are significant predictors of influenza morbidity and mortality. These findings have important implications for influenza vaccination, testing, and treatment policies and practices targeting the growing fraction of patients with cognitive impairment. PMID- 19874404 TI - Baseline lower extremity strength and subsequent decline in functional performance at 6-year follow-up in persons with lower extremity peripheral arterial disease. AB - OBJECTIVES: To evaluate associations between baseline lower extremity strength and decline in functional performance over 6 years of follow-up in men and women with lower extremity peripheral arterial disease (PAD). DESIGN: Prospective observational study. SETTING: Three Chicago-area hospitals. PARTICIPANTS: Three hundred seventy-four men and women with PAD. MEASUREMENTS: Baseline isometric hip extension, hip flexion, knee flexion, and knee extension strength were measured using a musculoskeletal fitness evaluation chair. Usual and fastest-paced 4-m walking speed, 6-minute walk, and Short Physical Performance Battery (SPPB) were assessed at baseline and annually thereafter. Analyses were adjusted for age, sex, race, ankle-brachial index (ABI), comorbidities, and other confounders. RESULTS: In women with PAD, weaker baseline hip and knee flexion strength were associated with faster average annual decline in usual-pace 4-m walking speed (P trend <.001 and .02, respectively) and SPPB (P trend=.02 and .01, respectively). In women, weaker hip extension strength was associated with faster decline in usual-pace 4-m walking speed and SPPB (P trend=.01 and <.01, respectively). There were no significant associations between baseline strength and decline in 6 minute walk in women. There were no significant associations between any baseline strength measure and functional decline in men. CONCLUSION: Weaker baseline leg strength is associated with faster functional decline in nonendurance measures of functional performance in women with PAD but not in men with PAD. PMID- 19874405 TI - Do hierarchical condition category model scores predict hospitalization risk in newly enrolled Medicare advantage participants as well as probability of repeated admission scores? AB - OBJECTIVES: To compare how well hierarchical condition categories (HCC) and probability of repeated admission (P(RA)) scores predict hospitalization. DESIGN: Longitudinal cohort study with 12-month follow-up. SETTING: A Medicare Advantage (MA) plan. PARTICIPANTS: Four thousand five hundred six newly enrolled beneficiaries. MEASUREMENT: HCC scores were identified from enrollment files. The P(RA) tool was administered by mail and telephone. Inpatient admissions were based on notifications. The Mann-Whitney test was used to compare HCC scores of P(RA) responders and nonresponders. The receiver operating characteristic curve provided the area under the curve (AUC) for each score. Admission risk in the top 5% of scores was evaluated using logistic regression. RESULTS: Within 60 days of enrollment, 45.1% of the 3,954 beneficiaries with HCC scores completed the P(RA) tool. HCC scores were lower for the 1,783 P(RA) respondents than the 2,171 nonrespondents (0.71 vs 0.81, P<.001). AUCs predicting hospitalization with regard to HCC and P(RA) were similar (0.638, 95% confidence interval (CI)=0.603 0.674; 0.654, 95% CI=0.618-0.690). Individuals identified in the top 5% of scores using both tools, using HCC alone, or using P(RA) alone had higher risk for hospitalization than those below the 95th percentile (odds ratio (OR)=8.5, 95% CI=3.7-19.4, OR=3.8, 95% CI=2.3-6.3, and OR=3.9, 95% CI=2.3-6.4, respectively). CONCLUSION: HCC scores provided to MA plans for risk adjustment of revenue can also be used to identify hospitalization risk. Additional studies are required to evaluate whether a hybrid approach incorporating administrative and self-reported models would further optimize risk stratification efforts. PMID- 19874406 TI - Life-space assessment in urogynecology and gynecological oncology surgery patients: a measure of perioperative mobility and function. AB - OBJECTIVE: To assess the effect of gynecological surgery on mobility and functional status in women aged 60 and older using Life-Space Assessment (LSA). DESIGN: Observational prospective cohort study. SETTING: Academic outpatient urogynecology and gynecological oncology clinics. PARTICIPANTS: Women presenting for urogynecology (n=51) and gynecological oncology (n=51) surgery. MEASUREMENTS: LSA scores 6 weeks, 6 months, and 1 year after surgery. Information on participant demographics, preoperative diagnoses, surgical approach, and medical comorbidities was collected. Analyses used repeated measures. RESULTS: Mean age was 71 +/- 7. Urogynecology participants started and maintained a higher LSA (P=.03) than oncology participants at all study intervals. Six weeks after surgery, urogynecology and oncology participants' mean decline was 13 points (95% confidence interval (CI)=4-21; P=.004) and 23 points (95% CI=13-33; P<.001), respectively. At 6 months, the urogynecology and oncology participants' scores increased by a mean of 9 points (95% CI=1-17; P=.03) and 13 points (95% CI=5-20; P=.001), respectively. No significant difference was found 1 year from baseline within each group or between groups in LSA scores. Income, depression, body mass index, and having an operative complication predicted a larger decline in life space over time in both groups. CONCLUSION: Gynecological surgical interventions in older women limit physical and functional ability at 6 weeks after surgery. The urogynecology and gynecological oncology cohorts returned to baseline levels by 6 months, which was sustained to 1 year. PMID- 19874407 TI - Self-reported adherence to nonpharmacological treatment and association with mortality over 6 years: population-based study in older persons with hypercholesterolemia. AB - OBJECTIVES: To determine the prevalence of self-reported adherence of older persons with hypercholesterolemia to nonpharmacological treatment prescribed by a physician and to describe its association with mortality. DESIGN: Population based prospective study. SETTING: Home interview and physical examination at baseline. PARTICIPANTS: Four thousand eight persons representative of the noninstitutionalized Spanish population aged 60 and older. MEASUREMENTS: Primary exposure variable was self-reported adherence to nonpharmacological treatment (weight control or loss, increased physical activity, and reduced saturated fat or cholesterol intake) in the 918 persons with known hypercholesterolemia in 2001. The outcome variable was mortality from all causes between 2001 and 2007. The association between self-reported adherence to nonpharmacological treatment and total mortality was studied using Cox models adjusted for main confounders. RESULTS: Most (83.8%) persons with known hypercholesterolemia reported adherence to at least one nonpharmacological measure, and 29.5% adhered to three measures. Those who reported increasing their physical activity had less mortality than those who did not (hazard ratio (HR)=0.68, 95% confidence interval (CI)=0.46 0.99; P<.05). Persons with hypercholesterolemia who reported adherence to one, two, or all three nonpharmacological measures had lower mortality than those who reported adherence to none of the measures (49%, 41%, and 60%, respectively, P for linear trend .002). No independent association with mortality was found for weight control or loss or dietary measures. CONCLUSION: Most of this population with known hypercholesterolemia reported adherence to at least one physician prescribed nonpharmacological measure. Reported adherence to all three measures was associated with the lowest mortality. PMID- 19874408 TI - The intersection of sex, marital status, and cardiovascular risk factors in shaping stroke incidence: results from the health and retirement study. AB - OBJECTIVES: To examine the role of sex and marital status in the distribution and consequences of cardiovascular risk factors for stroke. DESIGN: Longitudinal cohort. SETTING: U.S. national sample, community based. PARTICIPANTS: U.S. adults aged 50 and older and their spouses. MEASUREMENTS: Health and Retirement Study (HRS) participants born between 1900 and 1947 (N=22,818), aged 50 and older, and stroke-free at baseline were followed an average of 9.4 years for self- or proxy reported stroke (2,372 events). Financial resources, behavioral risk factors, and cardiovascular conditions were used to predict incident stroke in Cox proportional hazard models stratified according to sex and marital status (married, widowed, divorced or separated, or never married). RESULTS: Women were less likely to be married than men. The distribution of risk factors differed according to sex and marital status. Men had higher incident stroke rates than women, even after full risk factor adjustment (hazard ratio (HR)=1.22, 95% confidence interval (CI)=1.11-1.34). For both sexes, being never married or widowed predicted greater risk, associations that were attenuated after adjustment for financial resources. Widowed men had the highest risk (HR=1.40, 95% CI=1.12-1.74 vs married women). Lower income and wealth were associated with similarly high risk across subgroups, although this risk factor especially affected unmarried women, with this group reporting the lowest income and wealth levels. Most other risk factors had similar HRs across subgroups, although moderate alcohol use did not predict lower stroke risk in unmarried women. CONCLUSION: Stroke incidence and risk factors vary substantially according to sex and marital status. It is likely that gendered social experiences, such as marriage and socioeconomic disadvantage, mediate pathways linking sex and stroke. PMID- 19874409 TI - Alcohol, tobacco, and nonmedical drug use in older U.S. Adults: data from the 2001/02 national epidemiologic survey of alcohol and related conditions. AB - OBJECTIVES: To examine the prevalence and sociodemographic and health-related correlates of substance use, including alcohol, tobacco, and nonmedical drug use, in adults aged 65 and older. DESIGN: Cross-sectional, retrospective survey of a population-based sample, the 2001/02 National Epidemiologic Survey on Alcohol and Related Conditions. SETTING: United States. PARTICIPANTS: Eight thousand two hundred five U.S. adults aged 65 and older. MEASUREMENTS: Prevalence of lifetime and previous-12-month alcohol, tobacco, and nonmedical drug use and associations between substance use and sociodemographic and health-related factors. RESULTS: Almost 80% of older adults had used any of the three substances over their lifetimes, and more than 50% reported such use over the previous 12 months. Alcohol was the most commonly used substance over the lifetime (74%) and in the previous 12 months (45%), followed by tobacco (52% lifetime; 14% previous 12 months); far fewer reported nonmedical use of drugs (5% lifetime; 1% previous 12 months). In general, being younger, male, and divorced or separated were factors consistently associated with use of any of the three substances. CONCLUSION: Most older adults had used substances over their lifetimes and in the previous 12 months. Alcohol is the substance of choice for this age group, followed by tobacco; few report nonmedical drug use. PMID- 19874410 TI - Hearing acuity as a predictor of walking difficulties in older women. AB - OBJECTIVES: To examine whether hearing acuity correlates with walking ability and whether impaired hearing at baseline predicts new self-reported walking difficulties after 3 years. DESIGN: Prospective follow-up. SETTING: Research laboratory and community. PARTICIPANTS: Four hundred thirty-four women aged 63 to 76. MEASUREMENTS: Hearing was measured using clinical audiometry. A person was defined as having a hearing impairment if a pure-tone average of thresholds at 0.5 to 4 kHz in the better ear was 21 dB or greater. Maximal walking speed was measured over 10 m (m/s), walking endurance as the distance (m), covered in 6 minutes and difficulties in walking 2 km according to self-report. RESULTS: At baseline, women with hearing impairment (n=179) had slower maximal walking speed (1.7 +/- 0.3 m/s vs 1.8 +/- 0.3 m/s, P=.007), lower walking endurance (520 +/- 75 m vs 536 +/- 75 m, P=.08), and more selfreported major difficulties in walking 2 km (12.8% vs 5.5%, P=.02) than those without hearing impairment. During follow up, major walking difficulties developed for 33 participants. Women with hearing impairment at baseline had a twice the age-adjusted risk for new walking difficulties as those without hearing impairment (odds ratio=2.04, 95% confidence interval=0.96-4.33). CONCLUSION: Hearing acuity correlated with mobility, which may be explained by the association between impaired hearing and poor balance and greater risk for falls, both of which underlie decline in mobility. Prevention of hearing loss is not only important for the ability to communicate, but may also have more wide-ranging influences on functional ability. PMID- 19874411 TI - Cholinesterase inhibitor use in U.S. nursing homes: results from the national nursing home survey. AB - OBJECTIVES: To determine the frequency of cholinesterase inhibitor (ChEI) use in nursing home (NH) residents with dementia and examine correlates of ChEI use in this population. DESIGN: Cross-sectional study using the 2004 National Nursing Home Survey (NNHS). SETTING: A representative, stratified, random sample of U.S. NHs. PARTICIPANTS: All NNHS participants aged 65 and older with a chart diagnosis of dementia. MEASUREMENTS: Bivariate analyses to compare characteristics of NH residents with dementia according to ChEIs status and multivariable logistic regression to identify independent correlates of ChEI use. RESULTS: Almost half (49.1%) of NNHS participants had dementia, and 30.0% of those with dementia were receiving ChEIs. Donepezil accounted for 71% of all ChEI prescriptions. Multivariable logistic regression showed that ChEI use was independently associated with younger age (odds ratio (OR)=0.42, 95% confidence interval (CI)=0.28-0.64, aged > or =95 vs 65-74), less activity of daily living impairment (OR=0.49, 95% CI=0.42-0.58, severe vs mild impairment), greater use of antipsychotics (OR=1.33, 95% CI=1.16-1.54) and antidepressants (OR=1.38, 95% CI=1.20-1.59), and residence in NHs with more beds (OR=1.52, 95% CI=1.07-2.16, > or =200 beds vs <50 beds). CONCLUSION: Approximately 30% of NH residents with dementia in U.S. NHs are treated with ChEIs. Functional impairment and medical comorbidity are common in ChEIs users, although users tend to be younger and less impaired than NH residents with dementia who are not receiving ChEIs. Further study is required to determine the optimum use of ChEI in NH populations. PMID- 19874412 TI - The Jahnigen scholars program: a model for faculty career development. PMID- 19874413 TI - Modified hockey-stick approach to the mitral valve. AB - Modified biatrial approach to the mitral valve is described. The hockey-stick incision combines the advantage of excellent exposure with low surgical risk and easy reconstruction. PMID- 19874414 TI - Cusp shaving for concomitant mild to moderate rheumatic aortic insufficiency. AB - BACKGROUND: The aim of this study was to assess the early and mid-term results of patients who underwent cardiac operations due to cardiac pathologies other than aortic valve (AV) disease, but also had mild-to-moderate aortic valve insufficiency that was repaired during the same session. METHODS: A total of 43 patients who underwent AV repair for mild-to-moderate aortic insufficiency between January 2003 and February 2009, in addition to the procedure performed for their main pathology necessitating the surgical intervention, were included in the present study. Cardiac function was evaluated, before and after the operation. RESULTS: Hospital mortality rate was 4.6% (two patients). After the operations, significant improvements were observed in aortic insufficiency (0.57 +/- 0.50 vs. 2.86 +/- 0.48, p = 0.001), New York Heart Association class (1.08 +/ 0.28 vs. 3.03 +/- 0.44, p = 0.001), and left atrial diameter (47.37 +/- 9.28 vs. 42.35 +/- 7.02; p = 0.001). However, left ventricular end diastolic and end systolic diameters remained unchanged. Two patients were re-operated for AV disease during the follow-up period; thus, at five years, the rate of freedom from re-operation due to AV pathology was 90.7 +/- 6.3%. CONCLUSIONS: Cusp shaving is a feasible option that can be performed with low risk for concomitant aortic insufficiency. PMID- 19874415 TI - Cardiac calcified amorphous tumor. AB - Cardiac calcified amorphous tumor is a rare pseudoneoplastic intracavitary mass composed of calcium deposits in a background of amorphous degenerating fibrin. We report occurrence of this lesion in the right atrium in two male patients. These were accompanied by calcific occlusion of the inferior vena cava and right pulmonary artery. PMID- 19874416 TI - 64-Row MDCT demonstration of an unruptured aneurysm of the sinus of Valsalva. PMID- 19874417 TI - Unexpected persistent left superior vena cava and absent right superior vena cava in situs solitus patient. AB - We, herein, report a patient with persistent left superior vena cava with enlarged coronary sinus and absent right superior vena cava. This anomaly, diagnosed intraoperatively during the third open-heart surgery in the course of transesophageal echocardiography examination, was not mentioned during the patient's previous two cardiac operations. Challenges in intraoperative management and implications for subsequent treatments are discussed. PMID- 19874418 TI - Unusual manifestations of vascular rings. AB - Vascular rings are a relatively rare entity caused by abnormal development of the fetal aortic arches. Most patients with vascular rings present in infancy or early childhood with respiratory (inspiratory) symptoms. The treatment of patients with symptomatic vascular rings is generally straight-forward, focusing on surgical division of the ring. The majority of patients are "cured" by this simple procedure. However, a small percentage of patients do not follow this typical course. The purpose of this manuscript is to review and discuss three patients who demonstrated unusual manifestations of vascular rings. Two patients required reoperation after double aortic arch repair and one had successful treatment of an aberrant right subclavian artery. PMID- 19874419 TI - Dedifferentiation of human articular chondrocytes is associated with alterations in expression patterns of GDF-5 and its receptors. AB - Human articular chondrocytes are expanded in monolayer culture in order to obtain sufficient cells for matrix-associated cartilage transplantation. During this proliferation process, the cells change their shape as well as their expression profile. These changes resemble those that occur during embryogenesis, when the limb anlagen form the interzone that later develops the joint cleft. We analysed the expression profile of genes that are reportedly important for these changes during embryogenesis within the dedifferentiation process of adult articular chondrocytes. We found GDF-5, BMPR-Ib and connexin 43 up-regulated, as well as a down-regulation of BMPR-Ia and noggin. Connexin 32 could not be detected in either native cartilage or in dedifferentiated cells. The newly synthesized proteins were detected by immunofluorescence. There is evidence from our results that dedifferentiated chondrocytes resemble the cells from the interzone in developing synovial joints. PMID- 19874420 TI - Isthmin is a novel secreted angiogenesis inhibitor that inhibits tumour growth in mice. AB - Anti-angiogenesis represents a promising therapeutic strategy for the treatment of various malignancies. Isthmin (ISM) is a gene highly expressed in the isthmus of the midbrain-hindbrain organizer in Xenopus with no known functions. It encodes a secreted 60 kD protein containing a thrombospondin type 1 repeat domain in the central region and an adhesion-associated domain in MUC4 and other proteins (AMOP) domain at the C-terminal. In this work, we demonstrate that ISM is a novel angiogenesis inhibitor. Recombinant mouse ISM inhibited endothelial cell (EC) capillary network formation on Matrigel through its C-terminal AMOP domain. It also suppressed vascular endothelial growth factor (VEGF)-basic fibroblast growth factor (bFGF) induced in vivo angiogenesis in mouse. It mitigated VEGF-stimulated EC proliferation without affecting EC migration. Furthermore, ISM induced EC apoptosis in the presence of VEGF through a caspase dependent pathway. ISM binds to alphavbeta(5) integrin on EC surface and supports EC adhesion. Overexpression of ISM significantly suppressed mouse B16 melanoma tumour growth through inhibition of tumour angiogenesis without affecting tumour cell proliferation. Knockdown of isthmin in zebrafish embryos using morpholino antisense oligonucleotides led to disorganized intersegmental vessels in the trunk. Our results demonstrate that ISM is a novel endogenous angiogenesis inhibitor with functions likely in physiological as well as pathological angiogenesis. PMID- 19874421 TI - Phosphatidylinositol 3-kinase interacts with the glucocorticoid receptor upon TLR2 activation. AB - Airway inflammation is a common condition where glucocorticoids (GC) are a well established therapy. It has been demonstrated that GC stimulate components of innate immunity. Specifically, GC up-regulate TLR2 expression and activation upon inflammatory stimuli; however, little is known about the signalling involved in this process. To determine the mechanism by which dexamethasone modulates TLR2 induced cytokine production this signalling pathway was monitored in a lung epithelial cell line exposed to the TLR2 synthetic agonist, Pam(3) -Cys-Ser Lys(4) . These experiments demonstrate that phosphatidylinositol 3-kinase (PI3K) is critical for the TLR2 downstream effects of GC. Cells expressing a PI3K mutant (p85-dominant negative, DN; p85 Delta478-511) and exposed to Pam(3) -Cys-Ser Lys(4) in the presence or absence of dexamethasone, showed enhanced tumour necrosis factor (TNF)alpha expression while AP-1 and NF-kappaB transcriptional activity were repressed. We provide experimental evidence that PI3K physically interacts with the glucocorticoid receptor (GR) through two putative PI3K recruitment consensus YxxM binding motifs in the GR, suggesting that some functions regulated by this receptor might occur through kinase interaction. Mutations of two tyrosine residues in the GR, 598 and 663, to phenylalanine significantly reduced interaction with PI3K and the GC effects on TLR2-induced TNF-alpha expression. However, these mutations did not alter GR transcriptional activity nor affect cellular localization of the expressed mutant GR in COS-1 cells. Therefore, the PI3K-GR interaction may contribute to the effects of GC on the TLR2 pro-inflammatory signalling cascade, thus defining a novel signalling mechanism with a profound impact on innate immune responses. PMID- 19874422 TI - Serially heterotransplanted human prostate tumours as an experimental model. AB - * Introduction * Serially heterotransplanted human tumours in immunosuppressed mice: similarity to the tumour of origin - Cytological and histological analysis Karyotype - Marker expression - Other PC markers - Tumour cell proliferation and frequency of mitosis - Vasculature - Stromal compartment - Heterotransplant hormone dependency - Androgen dependent - Partially androgen dependent - Androgen independent - Metastases * Conclusions Preclinical research on prostate cancer (PC) therapies uses several models to represent the human disease accurately. A common model uses patient prostate tumour biopsies to develop a cell line by serially passaging and subsequent implantation, in immunodeficient mice. An alternative model is direct implantation of patient prostate tumour biopsies into immunodeficient mice, followed by serial passage in vivo. The purpose of this review is to compile data from the more than 30 years of human PC serial heterotransplantation research. Serially heterotransplanted tumours are characterized by evaluating the histopathology of the resulting heterotransplants, including cellular differentiation, karyotype, marker expression, hormone sensitivity, cellular proliferation, metastatic potential and stromal and vascular components. These data are compared with the initial patient tumour specimen and, depending on available information, the patient's clinical outcome was compared with the heterotransplanted tumour. The heterotansplant model is a more accurate preclinical model than older generation serially passaged or genetic models to investigate current and newly developed androgen deprivation agents, antitumour compounds, anti-angiogenic drugs and positron emission tomography radiotracers, as well as new therapeutic regimens for the treatment of PC. PMID- 19874423 TI - Involvement of neuropeptide Y and its Y1 and Y5 receptors in maintaining self renewal and proliferation of human embryonic stem cells. AB - Neuropeptide Y (NPY) and NPY receptors are widely expressed in various organs and cell types and have been shown to have pleiotropic functions. However, their presence or role in human embryonic stem cells (hESCs) remains unknown. We now show that undifferentiated hESCs primarily express NPY and its Y1 and Y5 receptors. Inhibition of NPY signalling using either the selective NPY Y1 or Y5 receptor antagonist reduces the maintenance of self-renewal and proliferation of undifferentiated hESCs. We also provide compelling evidence that exogenous NPY supports the long-term growth of undifferentiated hESCs in the absence of feeder cell factors using only knockout serum replacement media. Further, NPY facilitates the use of chemically defined medium made up of N2/B27 supplement and basic fibroblast growth factor (bFGF) for hESC feeder-free culture. Our results indicate that both Y1 and Y5 receptors appear to be involved in the NPY-mediated activation of AKT/protein kinase B and extracellular signal-regulated kinase 1/2 (ERK1/2) in hESCs. Notably, only Y1 receptor, but not Y5 receptor, is responsible for the NPY-induced activation of cAMP-response element binding (CREB) in hESCs. These results provide the first evidence that NPY and its Y1 and Y5 receptors have potential role in maintaining hESC self-renewal and pluripotency. We demonstrate the underlying importance of NPY signalling and its usefulness in the development of a defined and xeno-free culture condition for the large-scale propagation of undifferentiated hESCs. PMID- 19874424 TI - Exendin-4 regulates pancreatic ABCA1 transcription via CaMKK/CaMKIV pathway. AB - ATP-binding cassette transporter A1 (ABCA1) in pancreatic beta cells influences insulin secretion and glucose homeostasis. This study investigates whether the long-acting agonist of the glucagon-like peptide 1, namely exendin-4, which mediates stimulatory effects on ABCA1 gene expression, could interfere with the Ca(2+)/calmodulin (CaM)-dependent protein kinase (CaMK) cascade. ABCA1 promoter activity was examined by reporter gene assay in rat insulin-secreting INS-1 cells incubated with exendin-4. CaMKIV activity was assessed by detection of activation loop phosphorylation (Thr(196)) of CaMKIV. We investigated the influence of the constitutively active form (CaMKIVc) or CaMKIV knockdown on ABCA1 expression. Increased abundance of ABCA1 protein was noted in response to rising concentrations of exendin-4 with maximum induction at 10 nM. Exendin-4 also stimulated ABCA1 promoter activity, but failed to do so in the presence of STO 609, a CaMKK inhibitor. Up-regulation of CaMKIV phosphorylation (at Thr(196)) peaked after 10 min. of exposure to exendin-4. CaMKIVc enhanced or up-regulated ABCA1 promoter activity in INS-1 cells. Furthermore, exendin-4 induction of ABCA1 protein expression was significantly suppressed in cells treated with CaMKIV siRNA. Activation of the CaMKK/CaMKIV cascade by exendin-4 stimulated ABCA1 gene transcription, indicating that exendin-4 plays an important role in insulin secretion and cholesterol ester content in pancreatic beta cells. PMID- 19874425 TI - Metformin attenuates ovarian cancer cell growth in an AMP-kinase dispensable manner. AB - Metformin, the most widely used drug for type 2 diabetes activates 59 adenosine monophosphate (AMP)-activated protein kinase (AMPK), which regulates cellular energy metabolism. Here, we report that ovarian cell lines VOSE, A2780, CP70, C200, OV202, OVCAR3, SKOV3ip, PE01 and PE04 predominantly express -alpha(1), beta(1), -gamma(1) and -gamma(2) isoforms of AMPK subunits. Our studies show that metformin treatment (1) significantly inhibited proliferation of diverse chemo responsive and -resistant ovarian cancer cell lines (A2780, CP70, C200, OV202, OVCAR3, SKVO3ip, PE01 and PE04), (2) caused cell cycle arrest accompanied by decreased cyclin D1 and increased p21 protein expression, (3) activated AMPK in various ovarian cancer cell lines as evident from increased phosphorylation of AMPKalpha and its downstream substrate; acetyl co-carboxylase (ACC) and enhanced beta-oxidation of fatty acid and (4) attenuated mTOR-S6RP phosphorylation, inhibited protein translational and lipid biosynthetic pathways, thus implicating metformin as a growth inhibitor of ovarian cancer cells. We also show that metformin-mediated effect on AMPK is dependent on liver kinase B1 (LKB1) as it failed to activate AMPK-ACC pathway and cell cycle arrest in LKB1 null mouse embryo fibroblasts (mefs). This observation was further supported by using siRNA approach to down-regulate LKB1 in ovarian cancer cells. In contrast, met formin inhibited cell proliferation in both wild-type and AMPKalpha(1/2) null mefs as well as in AMPK silenced ovarian cancer cells. Collectively, these results provide evidence on the role of metformin as an anti-proliferative therapeutic that can act through both AMPK-dependent as well as AMPK-independent pathways. PMID- 19874426 TI - Prevalence and correlates of mental disorders in Israeli adolescents: results from a national mental health survey. AB - BACKGROUND: The development of epidemiological instruments has enabled the assessment of mental disorders in youth in countries that plan policy according to evidence-based principles. The Israel Survey of Mental Health among Adolescents (ISMEHA) was conducted in 2004-2005 in a representative sample of 957 adolescents aged 14-17 and their mothers. METHODS: The aims of this study were to estimate prevalence rates of internalizing and externalizing mental disorders and their socio-demographic and health correlates. Disorders were ascertained with the Development and Well-Being Assessment inventory and verified by child psychiatrists. RESULTS: The prevalence rates were 11.7%, 8.1% and 4.8% for any disorder, internalizing disorders and externalizing disorders, respectively. Distinct risk factors were associated with the different types of disorders: internalizing disorders were associated with female gender, chronic medical conditions and being cared for by a welfare agency. Risk factors for externalizing disorders were male gender, having divorced or single parents, being an only child or having only one sibling. Learning disability was associated with both types of disorders. CONCLUSIONS: The risk and protective factors related to internalizing and externalizing disorders are interpreted within the framework of family composition in this multicultural society. PMID- 19874428 TI - Lower maternal folate status in early pregnancy is associated with childhood hyperactivity and peer problems in offspring. AB - BACKGROUND: Maternal nutrition during pregnancy has been linked with fetal brain development and psychopathology in the offspring. We examined for associations of maternal folate status and dietary intake during pregnancy with brain growth and childhood behavioural difficulties in the offspring. METHODS: In a prospective cohort study, maternal red blood cell folate (RCF) was measured at 14 weeks of pregnancy and total folate intake (TFI) from food and supplements was assessed in early and late pregnancy. The offspring's head circumference and body weight were measured at birth and in infancy, and 100 mothers reported on children's behavioural difficulties at a mean age of 8.75 years using the Strengths and Difficulties Questionnaire. RESULTS: Lower maternal RCF and TFI in early pregnancy were associated with higher childhood hyperactivity (RCF: beta = -.24; p = .013; TFI: beta = -.24; p = .022) and peer problems scores (RCF: beta = -.28; p = .004; TFI: beta = -.28; p = .009) in the offspring. Maternal gestational RCF was positively associated with head circumference at birth (adjusted for gestational age), and mediation analyses showed significant inverse indirect associations of RCF with hyperactivity/inattention and peer problems via fetal brain growth. Adjustment for mother's smoking and drinking alcohol during pregnancy did not change the results. CONCLUSIONS: Although the associations are small and residual confounding is possible, our data provide preliminary support for the hypothesis that lower folate status in early pregnancy might impair fetal brain development and affect hyperactivity/inattention and peer problems in childhood. PMID- 19874427 TI - Research Review: 'Ain't misbehavin': Towards a developmentally-specified nosology for preschool disruptive behavior. AB - There is increasing consensus that disruptive behavior disorders and syndromes (DBDs) are identifiable in preschool children. There is also concomitant recognition of the limitations of the current DBD nosology for distinguishing disruptive behavior symptoms from the normative misbehavior of early childhood. In particular, there appears to be substantial insensitivity to heterotypic manifestations of this developmental period and problems in identifying meaningful heterogeneity. As a result, the developmental basis for much of the current nosology may be called into question. To address these and other critical issues, this paper reviews the foundational elements of clinical and developmental science pertinent to developmental differentiation of disruptive behavior in the preschool period as paradigmatic for developmental specification across the lifespan and generates an agenda for future research. We begin by reviewing evidence of the validity of DBDs in preschool children. This is followed by an outline of key developmental concepts and a review of the corollary evidence from developmental science. These provide a basis for conceptualizing disruptive behavior in reference to developmental deviation in four core dimensions hypothesized to mark the core features of disruptive behavior syndromes. Finally, we propose a program of research to establish an empirical basis for determining the incremental utility of a developmentally specified nosology. Central to this approach is a contention that the benefits of developmental specification are extensive and outweigh any disadvantages. This is because a developmentally specified approach holds substantial promise for increasing sensitivity and specificity for differentiating disruptive behavior from normative misbehavior and from other related syndromes as well as for improving prediction. Further, more precisely defined, developmentally based phenotypes are likely to elucidate distinct mechanisms within translational studies and to serve as a catalyst for the generation of novel treatments. PMID- 19874430 TI - An Italian shared dermatological and rheumatological proposal for the use of biological agents in psoriatic disease. AB - BACKGROUND: As psoriatic disease (PD) is a condition characterized by the combination of inflammatory skin (psoriasis) and osteo-articular manifestations (psoriatic arthritis), its treatment should cover both its clinical components. OBJECTIVE: The objective of this study was to propose a flexible framework for the use of biological agents in PD. METHODS: The proposal was drawn up by a group of dermatologists and rheumatologist expert in PD and was based on existing evidence and personal opinion. RESULTS: The three TNF-alpha inhibitors (adalimumab, etanercept, infliximab) are effective in all of the psoriatic manifestations and should be used in the case of moderate/severe disease refractory to systemic treatment with non-biological drugs. We propose the following definitions of moderate/severe disease: PASI > 10 or BSA > 10 or DLQI > 10 for plaque-psoriasis; BSA > or = 10 or DLQI > or = 10 for the other psoriatic skin lesions; DLQI > or = 10 or meaningful values of the NAPSI or mNAPSI for psoriatic nail involvement; > or = 1 inflamed joint + patient global VAS(3)4 + physician's judgement or arthritic joint deformities or radiographic joint damage plus > or = 5 inflamed small joints or > or = 1 large joints for peripheral joint involvement; > or = 1 digit with dactylitis and > or = 1 enthesitic sites + patient global VAS(3)4 + physician's judgement for dactylitis and enthesitis. BASDAI > or = 4 + physician's judgement for spondylitis; recurrent flares or risk of developing irreversible damage for uveitis. Other assessment instruments can be used if the physician is more familiar with them and if they have been validated. CONCLUSION We provide a shared dermatological and rheumatological proposal for the use of biological agents in PD. PMID- 19874429 TI - The temporal relation between depression and comorbid psychopathology in adolescents at varied risk for depression. AB - BACKGROUND: This study examined the temporal comorbidity of depressive disorders with anxiety, externalizing, and substance use disorders in adolescents who varied in risk for depression. METHODS: Participants were 240 adolescents and their mothers who had either a history of depression (high-risk, n = 185) or were lifetime-free of psychiatric disorders (low-risk, n = 55). Children (54.2% females) were first evaluated in 6th grade (mean age = 11.86, SD = .57) with the K-SADS-PL to assess current and lifetime diagnoses, and then annually through 12th grade with the A-LIFE to assess diagnoses since the previous evaluation. RESULTS: For girls, the rate of depression was high regardless of prior anxiety, whereas for boys, the odds that those with prior subthreshold anxiety would have subsequent subthreshold depression were 1.5 times those of boys with no prior subthreshold anxiety, controlling for risk. In addition, the odds that girls with prior substance use disorders would have a threshold depressive disorder subsequently were three times those of girls with no prior substance use disorders, controlling for risk. CONCLUSIONS: These results highlight the importance of early detection of various forms of psychopathology in youth who then can be targeted for intervention. The prospective paths to comorbidity differed by sex, thus suggesting that interventions need to be constructed with sensitivity to these distinct diagnostic trajectories. PMID- 19874431 TI - Analysis of four prevalent filaggrin mutations (R501X, 2282del4, R2447X and S3247X) in Austrian and German patients with atopic dermatitis. AB - BACKGROUND: Recently, mutations in the filaggrin gene (FLG) have been shown to be a major predisposing factor for atopic dermatitis (AD). OBJECTIVE: In this study, we evaluated the influence of four prevalent mutations (R501X, 2282del4, R2447X and S3247X) in a large cohort of 462 Austrian and German AD patients and in 402 control individuals. RESULTS: We found a strong association of the FLG mutations with AD. Subgroup analysis revealed a significantly higher proportion of patients with an early age of disease onset and significantly higher median serum IgE levels among mutation carriers. Furthermore, we observed an overrepresentation of null alleles in AD patients with concomitant asthma compared with those without this co-morbidity. CONCLUSION: Our data confirm and extend the knowledge of the influence of FLG mutations in AD. PMID- 19874432 TI - The risk of psoriatic arthritis remains constant following initial diagnosis of psoriasis among patients seen in European dermatology clinics. AB - BACKGROUND: Estimates of psoriatic arthritis (PsA) prevalence among psoriasis patients vary widely (5-40%). The time to development of PsA in patients with plaque psoriasis also remains unclear. OBJECTIVES: To examine whether length of time since diagnosis of psoriasis affects risk of developing PsA, and to assess differences in quality of life (QoL), work-related issues, comorbidities and healthcare resource utilization (HCRU) for patients with PsA vs. psoriasis. METHODS: This large cross-sectional observational study was conducted in the UK, Italy, France, Spain and Germany in 2006. Dermatologists who actively treated patients with psoriasis recruited 10 consecutive patients with psoriasis. Presence of PsA, body surface area (BSA) affected with psoriasis and HCRU were recorded; patients completed EUROQoL (EQ5D) and employment disadvantages questionnaires. RESULTS: Patients with psoriasis (n = 1560) included 126 with PsA. Ninety per cent of these patients with PsA were seen by dermatologists who involved a rheumatologist in the care of their patients with PsA. Survival analysis indicated that the incidence of PsA among psoriasis patients remained constant (74 per 1000 person-years), while the prevalence increased with time since diagnosis of psoriasis, reaching 20.5% after 30 years. In addition, those with high BSA currently affected by psoriasis were more likely to have developed PsA (P < 0.028). PsA patients reported reduced QoL compared with psoriasis patients (EQ5D score: 0.56 vs. 0.82: P < 0.0005), as well as more work problems. PsA patients were more likely to be hospitalized (0.27 +/- 0.84 vs. 0.14 +/- 0.71 per year; P < 0.0005) and have additional comorbidities than those without PsA. CONCLUSIONS: The incidence of PsA was constant after initial diagnosis of psoriasis, leading to a higher prevalence of concomitant PsA over time. PsA is associated with decreased QoL and increased work-related problems, HCRU and comorbidities. Dermatologists should screen for PsA in their patients, especially long-standing patients who did not initially present with PsA. PMID- 19874433 TI - Risk factors associated with rosacea. AB - BACKGROUND: Although rosacea is a common disease, the cause of disease is still a mystery -Helicobacter pylori infection, genetic predisposition, climatic factors, and detrimental habits are implicated as triggers of rosacea. OBJECTIVE: The aim of current study is to evaluate several suspected risk factors coincidently. METHODS: Patients with rosacea from a dermatology clinic and skin-healthy controls from an randomly selected employees' population enrolled the study. Skin status were evaluated by one and same dermatologist. Participants were queried for age, gender, sun-reactive skin type, and detrimental habits using a questionnaire; blood samples for detecting Helicobacter pylori serostatus were collected. RESULTS: Totally 145 skin-healthy controls and 172 subjects either with flushing episodes or established rosacea included the study. In multivariate analysis, rosacea patients had significantly higher chance to have photosensitive skin types (OR 1.75; 95% CI 1.01-3.04; P < 0.05), positive family history to rosacea (OR 4.31; 95% CI 2.34-7.92; P < 0.0001) or previous smoking status (OR 2.01; 95% CI 1.07-3.80; P < 0.05) comparing with skin-healthy controls. There were no statistically significant differences either in gender, Helicobacter pylori serostatus, caffeine intake, alcohol consumption, occupational environment, or education level between rosacea patients and controls. CONCLUSION: Rosacea is foremost associated with familial predisposition. There is no association between Helicobacter pylori infection and rosacea in current study. PMID- 19874434 TI - Retrospective analysis of systemic treatments for psoriasis patients attending a Psocare center in Florence. Relevance of biological drugs use and comorbidities. AB - BACKGROUND: Psoriasis is a chronic inflammatory skin condition associated with several risk factors and comorbidities. METHODS: The present study outlines patient and therapy profiles emerging from the analysis of 471 patients affected by plaque psoriasis or psoriatic arthritis (PsA). RESULTS: In our sample, the age of onset and first diagnosis of PsA is significantly higher than plaque psoriasis and about 65% of the patients are either smoker or ex-smokers, while 79% are not drinkers. We also report a different distribution in the use of systemic treatments compared to the Psocare report 2007, with a tendency for a larger use of biologics over classical systemic drugs and in particular etanercept is the main treatment for PsA, and efalizumab for plaque psoriasis. All biological treatments used in the study significantly reduced PASI score. The main comorbidity associated both with plaque psoriasis and with PsA was hypertension, while hyperlipidaemia was frequently present in patients under biologics treatment. Finally, a strong association between type II diabetes and PsA was also reported. CONCLUSIONS: Current treatments have to consider general health conditions and patients habits. In this picture, biological drugs are emerging as the therapy of choice for their good efficacy in the long term management of psoriasis. PMID- 19874435 TI - The evaluation of self-care and self-efficacy in patients undergoing hemodialysis. AB - PURPOSE: The purpose of this study is to assess patients' self-care ability and self-efficacy, to examine the relationship between them and to determine the factors affecting self-care ability and self-efficacy in people undergoing hemodialysis (HD). METHODS: This research was conducted as a descriptive survey study by 138 people with ESRD who were patients of HD units service in Sivas. The data were collected with a Personal Information Form, Exercise of Self-Care Agency (ESCA) Scale and Self-Efficacy Assessment Form. Data collected from the study were analysed using percent, mean, Tukey test, significance test of two means, one-way variant analysis and Kruskal-Wallis test. RESULTS: The study results demonstrate that while there is a correlation between self-care ability and education level, work status, income level and frequency of HD application, factors such as age, gender, education level, work status, income level and frequency of HD application determine self-efficacy. Furthermore, a positive correlation was found between patients' self-care ability and self-efficacy. It was determined that as the level of self-care ability increases self-efficacy level also increases. CONCLUSIONS: Hemodialysis application affects patients' self-care ability and self-efficacy levels. There is a positive correlation between self-care ability and self-efficacy. In view of this study's results, it is recommended to organize education programmes to increase self-care ability and self-efficacy levels of HD patients and prepare comprehensive plans including patients' families. PMID- 19874436 TI - Trial-generated profiles for implantation of electrical devices in outpatients with heart failure: real-world prevalence and 1-year outcome. AB - BACKGROUND: Randomized controlled trials have generated strong evidence on the efficacy of electrical device therapy in selected patients with heart failure (HF). The enrolment criteria of these three trials generated patient profiles that helped to shape current guidelines on chronic heart failure (CHF) treatment and sudden cardiac death (SCD) prevention. We investigated the prevalence of trial-generated profiles for implantable defibrillator or cardiac resynchronization therapy candidacy among HF outpatients; we explored differences between real-world and trial populations and we evaluated 1-year survival without device treatment. METHODS: We reviewed Italian Network on Congestive Heart Failure (IN-CHF) registry patients (n = 4977) enrolled in a period (1995-2000) roughly concurrent with the MADIT-II and SCD-HeFT trials. RESULTS: Regarding device eligibility, 14.5% IN-CHF patients at entry satisfied MADIT-II criteria, 6.8% satisfied CARE-HF criteria and as many as 47.9% fulfilled SCD-HeFT criteria. One-year overall mortality among non-implanted patients was 1.5 to 2-fold higher in each of these subgroups than in control arms of the corresponding trials. Among registry patients, different trial-profile combinations were associated with a wide range of 1-year outcomes (mortality, 8-35%; SCD/total mortality ratio, 0.35-0.57). Despite clear differences between registry and trial patients in pharmacological therapy (and clinical characteristics), none of the main drug classes independently predicted 1-year mortality in any of the IN-CHF subgroups. CONCLUSIONS: As many as half the IN-CHF outpatients fulfilled current criteria for device implantation. Various subgroups had higher 1-year mortality than patients in trial control arms - a finding that may not be entirely attributable to differences in drug therapy (especially beta blockers). PMID- 19874437 TI - Strengthening conflict-of-interest policies in medicine. AB - RATIONALE, AIMS AND OBJECTIVES: Conflict-of-interest (COI) policies have played a vital role in protecting the integrity of science as well as protecting patients' welfare. However, the usefulness of these policies could be enhanced by addressing gaps in disclosure requirements, especially insofar as these gaps may impede the intended neutrality of COI policies. For example, current COI policies have not addressed potential conflicts created by indirect industry funding, such as when pharmaceutical companies provide general funding to researchers' academic departments or to medical educational programmes. Nor do they address the consequent creation of climates of opinion, which may marginalize important criticisms and undermine progress on this important policy issue. METHODS: The authors used a critical thinking approach to analyze the gaps in existing COI policies. CONCLUSION: Taking the position that a more adequate system of checks and balances is needed, the authors offer specific recommendations for improving current policies and for addressing the issue of indirect support. PMID- 19874438 TI - Co-evolution of plumage characteristics and winter sociality in New and Old World sparrows. AB - Understanding the evolution of phenotypic diversity, including the stunning array of avian plumage characters, is a central goal of evolutionary biology. Here, we applied a comparative analysis to test factors associated with the origin and maintenance of black chest and throat patches, which in some taxa are referred to as 'badges-of-status'. Specifically, we tested whether the evolution of black colour patches in Old and New World sparrows is consistent with a signalling function during the nonbreeding season or breeding season. We found no positive associations between patch evolution and polygyny or summer sociality. Instead, patch evolution is significantly associated with sociality during the nonbreeding season. Additionally, unlike typical plumage characteristics under sexual selection, these patches are visible throughout the nonbreeding season. Further, the pattern of patch dimorphism uncovered in this study does not match expectations for a trait that evolved in a reproductive context. In particular, patch dimorphism is not associated with polygyny or the presence of extra-pair mating although other types of plumage dimorphism are strongly associated with nonmonogamous mating systems. Overall, patterns of patch evolution suggest that they are more strongly associated with social competition during the nonbreeding season than sexual competition during the breeding season. These results clarify why some previous work has uncovered puzzling relationships between black plumage patches and reproductive behaviour. We discuss these findings in the context of signal theory and previous work on badges-of-status. PMID- 19874439 TI - Sexual selection and condition-dependence. AB - The handicap theory of sexual selection suggests that females prefer mates who display extravagant ornaments that advertise their quality or condition. It is often assumed that as such ornamental traits undergo sexually-selected exaggeration, they must inevitably become more sensitive to condition, and thus more informative. Here, we show that this is not necessarily the case. Depending on the precise form of the relationship between trait size and cost, expression may become more or less condition-dependent as the trait undergoes exaggeration, or may remain unchanged. This leads us to question how much of the information content of sexual signals can be attributed to sexual selection, and how much to pre-existing, naturally-selected condition-dependence. PMID- 19874440 TI - The ontogeny of cross-sex genetic correlations: an analysis of patterns. AB - The independent evolution of males and females is typically constrained by shared genetic variance. Despite substantial research, we still know little about the evolution of cross-sex genetic covariance and its standardized measure, the cross sex genetic correlation (r(MF)). In particular, it is unclear if r(MF) tend to vary with age. We compiled 28 traits for which ontogenetic trends in r(MF) were documented. Decreases in r(MF) with age were observed significantly more often than increases and the mean effect size for the relationship between r(MF) and age was large and negative. This suggests that sexual dimorphism (SD) may typically evolve more readily for phenotypes expressed later in ontogeny and that evolutionary inferences related to the evolution of SD should be limited to the ontogenetic stage at which r(MF) was estimated. Knowledge about ontogenetic variation in r(MF) should help improving our understanding of evolutionary patterns related to SD and the resolution of intralocus sexual conflicts. PMID- 19874441 TI - Study of the cytochrome b gene sequence in populations of Taiwan. AB - The cytochrome b gene (MTCYB) has been widely used in taxonomic research. In this study, the sequence polymorphism of the MTCYB gene was determined in 417 subjects of eight populations living in Taiwan (Taiwanese Han, indigenous Taiwanese, Tao, mainland Chinese, Filipino, Thai, Vietnamese, and Caucasian). Sequence variation from the revised Cambridge Reference Sequence and genetic distance between these populations were analyzed. There were 108 variable positions with a total of 99 haplotypes. Population-specific positions of MTCYB gene were noted in Tao and Caucasian populations. There were statistically significant differences of genetic distance between Taiwanese Han and Caucasian, between Taiwanese Han and Tao, and between Taiwanese Han and Filipino. A phylogenetic tree presents the genetic distances between these populations. In conclusion, there are sufficient sequence polymorphisms of the MTCYB gene in individuals of different populations, which may be used in the analyses of human ethnic groups in forensic casework. PMID- 19874442 TI - Protecting effects of a large dose of dexamethasone on spleen injury of rats with severe acute pancreatitis. AB - BACKGROUND AND AIMS: To explore the protecting effects and mechanisms of dexamethasone on spleen injury in rats with severe acute pancreatitis (SAP). METHODS: The rats were randomly divided into a model control group, treated group and sham-operated group. The contents of plasma endotoxin, serum NO, phospholipase A(2) enzyme (PLA(2)) and endothelin-1 (ET-1) were determined. The mortality rate, pathological changes and changes of Bax and Bcl-2 protein expression levels and apoptotic indexes in the spleen of rats were observed in all groups, respectively, at 3, 6 and 12 h after operation. RESULTS: Although the survival rate was significantly higher in the treated group than in the model control group, there was no significantly different between them (P > 0.05). The expression levels of Bax and Bcl-2 proteins and apoptotic indexes were significantly higher in the treated group than in the model control group at different time points (P < 0.05 or P < 0.01) while other blood indexes contents and pathological severity scores of spleen were significantly lower in the treated group than in the model control group (P < 0.05, P < 0.01 or P < 0.001). CONCLUSION: Dexamethasone can protect spleen from injury during SAP mainly by reducing the content of inflammatory mediators in blood. PMID- 19874443 TI - Eukaryotic expression of extracellular ligand binding domains of murine Tie-2 and its anti-angiogenesis effect in SGC-7901 cell lines. AB - BACKGROUND AND AIMS: Researches about blocking angiogenesis to treat tumor have become one of the most promising and active fields in anticancer research. This study aimed to investigate the eukaryotic expression of extracellular ligand binding domains of murine Tie-2 and its anti-angiogenesis effect. METHODS: A eukaryotic expression vector pcDNA3.1(+) integrating with a DNA fragment which encode extracellular ligand binding domains of murine Tie-2 was transfected into SGC-7901 gastric cancer cell line. The protein expression was detected by western blot analysis and immunocytochemistry staining. Following the construction of nude mouse tumor xenograft model with and without transfected cells, tumor microvessel density was determined by counting per high power field in the sections stained with an antibody to CD31 to test its inhibition of angiogenesis. RESULTS: The extracellular ligand binding domains of murine Tie-2 receptor was highly expressed in SGC-7901 gastric cancer cells with plasmid transfection. The mean tumor sizes of groups with and without transfection were 1.27 +/- 0.35 and 1.75 +/- 0.17 cm(3), respectively (P = 0.025). The mean inhibitory rate of tumor was 27.18 +/- 19.93%. The comparison between highest microvessel density of group with transfection (14.00 +/- 3.80) and that of group without transfection (22.30 +/- 5.91) was statistically significant at P = 0.030. CONCLUSION: The protein of extracellular ligand binding domains of murine Tie-2 can be expressed at high level in the eukaryotic expression system, and the expressed protein may have the anti-angiogenesis effect. PMID- 19874444 TI - Oral buffered esomeprazole is superior to i.v. pantoprazole for rapid rise of intragastric pH: a wireless pH metry analysis. AB - BACKGROUND AND AIMS: A pH of more than 6 is required for clot stability and hemostasis. Intravenous proton pump inhibitors have a rapid onset of action compared to oral and have been preferred for management of non-variceal bleeding. Intravenous pantoprazole has been used extensively. Buffered esomeprazole (BE) is an oral preparation consisting of an inner core of non-enteric-coated esomeprazole with a shell of sodium bicarbonate. The buffer protects against acid degradation of esomeprazole in addition to immediate antacid action. The aim of this study was to assess the efficacy of BE for raising and maintaining an intragastric pH of more than 6 in comparison to i.v. pantoprazole in equivalent dosing. METHODS: A randomized two-way cross-over study was conducted. Ten healthy volunteers were randomized to twice daily BE 40 mg or pantoprazole 40 mg i.v. bolus. Intragastric pH was measured with a wireless pH radiotelemetry capsule (Bravo, Medtronic). A 2-week washout period was given between doses. RESULTS: BE achieved a steady pH of more than 6 in a median time of 2 min (range 1-5 min) after the first dose. The mean % time that intragastric pH was more than 6.0 for BE was 96%, and 90% of the 24-h period compared to pantoprazole (47% and 18%), P = 0.000. A median pH (interquartile range) for the BE group was 6.2 (6.175-6.2) which was higher than i.v. pantoprazole 4.60 (4.5-5.0) (P = 0.005). CONCLUSION: BE achieves and maintains a pH of more than 6 within minutes of administration. It was significantly superior to i.v. pantoprazole in equivalent dosing. This finding could have implications in the management of non-variceal bleed where a rapid and sustained pH of more than 6 is desirable. PMID- 19874445 TI - Narrow-band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma. AB - BACKGROUND AND AIMS: Head and neck cancers, especially pharyngeal cancers, as well as esophageal cancers frequently coexist either synchronously or metachronously, but most cases of pharyngeal cancer are detected at an advanced stage resulting in poor prognosis. The aim of this study is to evaluate the effectiveness of using narrow-band imaging (NBI) endoscopy with magnification for early detection of pharyngeal cancer on patients following their treatment for esophageal squamous cell carcinoma (SCC). METHODS: This case series was conducted at the National Cancer Center Hospital in Tokyo between April and October 2005 and included 424 consecutive patients for surveillance endoscopy who had previously undergone chemoradiotherapy (CRT) and/or surgery for esophageal SCC. Observation of the pharyngeal region was randomly conducted on 91 patients using NBI endoscopy with magnification (NBI group) and 333 patients using conventional white light endoscopy (control group). RESULTS: The detection rate for pharyngeal cancer was significantly higher using NBI endoscopy with magnification (10.9%; 10/91) compared with conventional endoscopy (1.2%; 4/333) (P < 0.0001). In particular, the detection rate in CRT patients was significantly higher in the NBI group (12.9%; 7/54) than the control group (0.5%; 1/191) (P < 0.0001). In addition, diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the NBI group were 100% (10/10), 97.5% (79/81), 97.8% (89/91), 83.3% (10/12) and 100% (79/79), respectively. CONCLUSION: NBI endoscopy with magnification is a promising technique for detecting superficial pharyngeal cancer at an early stage in patients previously treated for esophageal SCC. PMID- 19874446 TI - Sex differences in epidemiological, clinical and pathological characteristics of colorectal cancer. AB - Sex significantly influences the clinical and pathological characteristics of colorectal cancer (CRC). These include differences in incidence and mortality rates, clinical presentations including age, emergency surgery for complications from CRC, screening participation rates, site, stage and treatment utilization, histopathology and survival. Environmental, behavioral and biological factors contribute to the differential risk. Recent advances in the molecular biology of CRC, specifically in microsatellite status, estrogen hormone and estrogen receptor beta, have led to greater understanding of the effect of estrogen in colorectal carcinogenesis. Estrogen may preferentially protect against microsatellite unstable cancers through its effect on selected molecular targets; however, the exact pathways have not been elucidated. Recognition of important sex disparities in these areas may lead to the implementation of specific measures to diminish these differences and facilitate equitable distribution of health resources. Identifying specific molecular targets on CRC that interact with estrogen may stimulate research to improve the overall outcomes of all patients with CRC. PMID- 19874447 TI - Social cognition in children with Down's syndrome: challenges to research and theory building. AB - Characterising how socio-cognitive abilities develop has been crucial to understanding the wider development of typically developing children. It is equally central to understanding developmental pathways in children with intellectual disabilities such as Down's syndrome. While the process of acquisition of socio-cognitive abilities in typical development and in autism has received considerable attention, socio-cognitive development in Down's syndrome has received far less scrutiny. Initial work in the 1970s and 1980s provided important insights into the emergence of socio-cognitive abilities in the children's early years, and recently there has been a marked revival of interest in this area, with research focusing both on a broader range of abilities and on a wider age range. This annotation reviews some of these more recent findings, identifies outstanding gaps in current understanding, and stresses the importance of the development of theory in advancing research and knowledge in this field. Barriers to theory building are discussed and the potential utility of adopting a transactional approach to theory building illustrated with reference to a model of early socio-cognitive development in Down's syndrome. The need for a more extensive model of social cognition is emphasised, as is the need for larger scale, finer-grained, longitudinal work which recognises the within-individual and within-group variability which characterises this population. The value of drawing on new technologies and of adapting innovative research paradigms from other areas of typical and atypical child psychology is also highlighted. PMID- 19874448 TI - Using personal goal setting to promote the social inclusion of people with intellectual disability living in supported accommodation. AB - The social exclusion of persons with intellectual disability is more marked in congregated than in individualised supported accommodation. Goal setting was used as a means of increasing individuals' choices and engaging support staff in personalised planning. Method People living in four different housing and support options were invited to identify up to three 'social inclusion' goals they wanted to achieve in the coming months. Nine months later, a review was undertaken to see if their goals had been attained and also to identify what had helped or hindered individuals in doing this. The goal selection was then repeated and reviewed again after a further 9 months. Results The most commonly chosen goals were around social activities with other people and over half the participants were reported to have attained at least one of their goals within 9 months, particularly those in supported living arrangements that had greater hours of individual staff support. In the second 9-month period, fewer people chose goals, although the same proportion as before were successful. The main reason given for goal attainment was the information and support provided by staff. Conclusions Goal setting seems a suitable way of promoting social inclusion as it can be tailored to the needs and aspirations of individuals, although extra efforts may be needed to implement and sustain it with staff across all accommodation options. PMID- 19874450 TI - Is the reverse cycle during chewing abnormal in children with primary dentition? AB - The purpose of this study was to clarify whether the reverse cycle during chewing is abnormal in children with primary dentition. Children with normal primary dentition (N = 23; 5.5 +/- 0.8 years) and female adults (N = 25; 20.7 +/- 1.9 years) participated in this study. Chewing movement was recorded using an opto electronic analysis system with six degrees-of-freedom (TRI-MET, Tokyo-shizaisha; Tokyo, Japan). Each subject was given a stick of chewing gum (new TRIDENT, WARNER LAMBERT CO., Morris Plains, NJ, USA) and instructed to chew it normally. Starting from the maximum intercuspal position, each chewing sequence was recorded over a period of 20 s. A custom computer program identified individual chewing cycles. Frontal views were used to distinguish seven types of cycle shapes according to Ahlgren (Acta Odontol Scand, 24, 1966, 1-109; Acta Odontol Scand, 25, 1967, 3 13). Multilevel statistical models evaluated differences between children and adults. In the adults, type II cycles that initially opened towards the balancing side and then moved towards the working side were the most common, and the closing pathway was lateral to the opening pathway. In the children, type V (reverse) cycles that opened towards the working side were most common, the closing pathway was medial to the opening pathway, and there was a smaller lateral component during opening and closing than in adults (P < 0.05). We conclude that the reverse cycle is not abnormal because normal children with primary dentition have a smaller lateral component and difficulty in controlling asymmetric muscle activity. PMID- 19874449 TI - Resilience and the course of daily parenting stress in families of young children with intellectual disabilities. AB - BACKGROUND: Parenting stresses have consistently been found to be higher in parents of children with intellectual disabilities (ID); yet, some families are able to be resilient and thrive in the face of these challenges. Despite the considerable research on stress in families of ID, there is still little known about the stability and compensatory factors associated with everyday parenting stresses. METHODS: Trajectories of daily parenting stress were studied for both mothers and fathers of children with ID across child ages 36-60 months, as were specific familial risk and resilience factors that affect these trajectories, including psychological well-being of each parent, marital adjustment and positive parent-child relationships. RESULTS: Mothers' daily parenting stress significantly increased over time, while fathers' daily parenting stress remained more constant. Decreases in mothers' daily parenting stress trajectory were associated with both mother and father's well-being and perceived marital adjustment, as well as a positive father-child relationship. However, decreases in fathers' daily parenting stress trajectory were only affected by mother's well being and both parents' perceived marital adjustment. CONCLUSIONS: Parenting stress processes are not shared entirely across the preschool period in parents of children with ID. Although individual parent characteristics and high-quality dyadic relationships contribute to emerging resilience in parents of children with ID, parents also affect each others' more resilient adaptations in ways that have not been previously considered. PMID- 19874451 TI - Discriminant analysis of patients' reasons for choosing or refusing treatments for partial edentulism. AB - The aim of the study was to explore partially edentulous patients' reasons for choosing or refusing prosthodontic treatment with removable partial dentures (RPD), fixed partial dentures (FPD) and implant partial dentures (IPD). Clinical and oral health-related quality of life measures were collected from 165 partially edentulous patients undergoing treatment. Patients' preferences were recorded and reasons for choosing or refusing treatments were measured with 32 questions using a five-point Likert scale. Descriptive statistics, chi-square and multiple logistic regression were used to compare patients' preferences according to clinical variables. Discriminant analysis was used to examine the impact of each reason for a patient's decision to choose or refuse treatment options. Results showed that older patients (P < 0.001) and with greater oral-related quality of life impacts (P < 0.05) were more likely to choose RPD. IPD were preferred by patients with higher education levels (P < 0.01). Discriminant functions revealed that the desire to have a fixed or removable denture had great impact on preferences. Removal of tooth structure was the main reason for refusing FPD and financial cost had a great impact on refusing IPD. Overall agreement between observed patients' decisions and those predicted by the discriminant function was >90% for all treatments. Reasons vary greatly among patients, and the role of individual perception of potential reasons for treatment selection was the most important determinants of patients' decisions. The main reasons for choosing or refusing treatments focused in this study can be used to guide shared decision-making, providing treatments that better match patients' expectations and desires. PMID- 19874452 TI - Periodontal bacteremia and various vascular diseases. AB - BACKGROUND AND OBJECTIVE: Weak oral bacteria, such as periodontal bacteria, have been found in various vascular lesions, including atheroma, the thrombus of the occluded artery of Buerger's disease, the abdominal aortic aneurismal wall and varicose veins. Serum titer levels of each bacterium are now available and have shown a significant relationship between severity and individual differences. MATERIAL AND METHODS: The Medline and Tokyo Medical and Dental University databases were searched to identify the literature currently available on oral bacteria and vascular diseases. RESULTS: It is estimated that lymph vessel openings trap bacteria en route from the mouth to the bloodstream and then carry them to the vein of the venous angle near the supraclavicular area. In the case of periodontal bacteria, a typical bacterium, such as Porphyromonas gingivalis, strongly activates platelets and makes them mass, including the bacteria without phagocytosis. Simultaneously, cytokines and serotonin are discharged. Platelet engulfment was clearly demonstrated by electron microscopy analysis. An animal study using rats showed the formation of a small arterial thrombus after continuous intravenous infusion of P. gingivalis for 2-4 wk. CONCLUSION: Weak oral bacteria, such as periodontal bacteria, may play an important role in the development of various vascular diseases, such as Buerger's disease, atherosclerosis and varicose veins, through bacteremia. PMID- 19874453 TI - Triclosan inhibits tumor necrosis factor-alpha-stimulated urokinase production in human gingival fibroblasts. AB - BACKGROUND AND OBJECTIVES: Destruction of the supporting periodontal tissues is mediated by the action of several proteolytic enzymes. Urokinase is a serine protease that plays a key role in connective tissue destruction through conversion of plasminogen into plasmin. The present study was conducted to evaluate the effect of triclosan on the production and activity of urokinase in cultured gingival fibroblasts. MATERIAL AND METHODS: Urokinase production was studied in primary cultures of human gingival fibroblasts stimulated with tumor necrosis factor-alpha. Urokinase activity and production were evaluated using casein zymography and western blotting, respectively. Urokinase mRNA expression was evaluated using the reverse transcription-polymerase chain reaction. Triclosan was used to interfere with this stimulatory effect. The roles of different cell-signaling cascades involved in urokinase production were assessed through western blotting and immunofluorescence using several cell-signaling inhibitors. RESULTS: Tumor necrosis factor-alpha was found to be a strong stimulus for urokinase production and triclosan was able to inhibit this response at the protein and mRNA levels. Triclosan was also able to inhibit conversion of plasminogen into plasmin. Tumor necrosis factor-alpha-stimulated urokinase production was shown to be dependent on the nuclear factor-kappaB and c-Jun N terminal kinase signaling pathways. Triclosan inhibited c-Jun N-terminal kinase phosphorylation and c-Jun production. CONCLUSIONS: Within the limits of this study, these results show that triclosan may inhibit urokinase production and plasminogen activation in gingival fibroblasts through modulation of the c-Jun N terminal kinase signaling pathway. PMID- 19874454 TI - Genetic testing for von Willebrand disease: the case for. PMID- 19874455 TI - Coronary atherosclerosis and cardiovascular mortality in hemophilia. PMID- 19874456 TI - To bleed or not to bleed - is that a question? PMID- 19874457 TI - Volumetric or time-based capnography for excluding pulmonary embolism in outpatients? AB - BACKGROUND: Volumetric capnography is technically more demanding but theoretically better than the time-based alveolar deadspace fraction (P(a)CO(2) - EtCO(2))/P(a)CO(2) as a bedside diagnostic tool for excluding pulmonary embolism (PE) in outpatients. OBJECTIVE: We compared both diagnostic accuracy in patients with a suspected PE and positive D-dimer enzyme-linked immunosorbent assay results. PATIENTS AND METHODS: In this clinical multicenter trial with prospective inclusion and 3-month follow-up, alveolar deadspace fraction was compared by receiver operating characteristic (ROC) analysis with other parameters derived from volumetric capnography. RESULTS: Capnography was performed in 239 patients, and 205 tests (86%) were conclusive. The incidence of PE was 33%. The alveolar deadspace fraction accuracy expressed with ROC curve analysis was 0.73 +/- 0.04. The diagnostic performances of parameters from volumetric capnography were not significantly better. Sixteen per cent [95% confidence interval (CI) 12-21%] of patients presented a (P(a)CO(2) - EtCO(2))/P(a)CO(2) ratio under the cut-off value of 0.15, with a low clinical probability. This combination excluded PE, with a sensitivity of 96% (95% CI 89 99%) and a negative likelihood ratio of 0.17 (95% CI 0.09-0.33%). CONCLUSION: Volumetric capnography failed to show superiority to alveolar deadspace fraction measurements [(P(a)CO(2) - EtCO(2))/P(a)CO(2)] for exclusion of PE in outpatients with positive D-dimer test results. Future studies should clarify the safety of excluding PE in patients combining low clinical probability with positive D-dimer results and (P(a)CO(2) - EtCO(2))/P(a)CO(2) ratios below the cut-off value of 0.15. PMID- 19874458 TI - Arterial thrombosis: relevance of a model with two levels of severity assessed by histologic, ultrastructural and functional characterization. AB - BACKGROUND: We previously described a model of laser-induced thrombosis in mesenteric arterioles with superficial and deep levels of injury producing a transient thrombus resolving within 2 min and a larger almost occlusive thrombus, respectively. Both types of lesion were sensitive to platelet GPIIb-IIIa and P2Y(12) inhibition, whereas only deep injuries were sensitive to thrombin blockade. OBJECTIVE: The aim of the present study was to use histologic methods and electron and intravital microscopy to characterize the lesions and thrombi and to extend our knowledge of the sensitivity of this model to genetic and pharmacologic inhibition. RESULTS: A superficial injury was found to detach the endothelial cells and expose a collagen III- and IV-rich subendothelium where platelets could adhere. Tissue factor and fibrin were not detected. Deeper penetration of the external elastic lamina occurred in deep injuries, with exposure of collagen I, III and IV. Here the thrombus was composed of platelets exhibiting a decreasing gradient of degranulation from the deepest lesion area to the surface. Fibrin was found close to the most activated platelets. Consistently, glycoprotein VI (GPVI)-collagen and GPIb-von Willebrand factor (VWF) interactions were found to be critical in superficial injuries. After deep lesion, thrombus formation was modestly reduced in GPVI-immunodepleted mice and still strongly inhibited in VWF(-/-) mice. Combined hirudin infusion and GPVI depletion further inhibited thrombosis after deep injury. CONCLUSIONS: This study confirms the feasibility of inducing arterial thrombosis with distinct levels of severity and establishes the central roles of collagen and VWF in thrombus formation after superficial injury. Collagen, VWF and thrombin all appear to contribute to thrombosis after deep arterial lesion. PMID- 19874459 TI - The plasma von Willebrand factor O-glycome comprises a surprising variety of structures including ABH antigens and disialosyl motifs. AB - BACKGROUND: von Willebrand factor (VWF) is a key component for maintenance of normal hemostasis. Its glycan moieties, accounting for about 20% of its molecular weight, have been shown to affect many of its properties. Previous studies reported correlations between VWF secretion, half-life and the nature or presence of its N-glycans, and more importantly between VWF plasma level and the type of N linked ABH antigens. Despite the presence of 10 predicted O-glycosylation sites, the O-glycome remains poorly characterized, impairing the complete elucidation of its influence on VWF functions. So far only a single glycan structure, a disialyl core 1 glycan, has been identified. OBJECTIVES: To define an exhaustive profile of the VWF O-glycan structures to help the understanding of their role in VWF regulation and properties. METHODS: Plasma-derived VWF O-linked sugars were isolated and analyzed using state-of-the-art mass spectrometry methodologies. RESULTS AND CONCLUSIONS: We provide here a detailed analysis of the human plasma derived VWF O-glycome. Eighteen O-glycan structures including both core 1 and core 2 structures are now demonstrated to be present on VWF. Amongst the newly determined structures are unusual tetra-sialylated core 1 O-glycans and ABH antigen-containing core 2 O-glycans. In conjunction with current models explaining VWF activity, knowledge of the complete O-glycome will facilitate research aimed at providing a better understanding of the influence of glycosylation on VWF functions. PMID- 19874460 TI - The discovery of the endothelial cell protein C receptor. PMID- 19874461 TI - Platelet-bound P-selectin expression in patients with coronary artery disease: impact on clinical presentation and myocardial necrosis, and effect of diabetes mellitus and anti-platelet medication. PMID- 19874462 TI - The mitogen-activated protein kinase signaling pathways: role in megakaryocyte differentiation. AB - Megakaryopoiesis is a process by which bone marrow progenitor cells develop into mature megakaryocytes (MKs), which in turn produce platelets required for normal hemostasis. The mitogen-activated protein kinases (MAPKs) family comprises four main groups of proteins: extracellular signal-related kinases (ERKs) (ERK1/2 or p44/p42), ERK5, p38MAPKs (alpha, beta, gamma, delta) and c-Jun amino-terminal kinases (JNKs) (JNK 1, 2, 3). These intracellular signaling pathways play a pivotal role in many essential cellular processes including proliferation and differentiation. The purpose of this review is to summarize our current knowledge on the role of MAPKs in MKs, specifically regarding differentiation in immortalized cell lines and primary MKs. A critical role of the MEK (MAPK kinase) ERK1/2 pathway in MK development has been demonstrated although the details remain controversial. There is at present no functional evidence for a role of p38MAPKs whereas the role of JNKs and ERK5 in MK development is not known. Characterization of these molecular event cascades remains crucial for the understanding of the megakaryopoiesis process. PMID- 19874463 TI - Novel APC-cleavage sites in FVa provide insights into mechanisms of action of APC and its cofactor protein S. AB - BACKGROUND: Activated protein C (APC) inhibits factor Va (FVa) by cleaving at Arg306, Arg506 and Arg679. Protein S serves as cofactor, in particular for the Arg306 site, and a protein S-mediated relocation of the active site of APC closer to the membrane has been proposed as a mechanism. Recently, it was demonstrated that FVa, which was mutated at all three APC-cleavage sites (FVa-306Q/506Q/679Q), could still be cleaved by APC. These sites were close to Arg306 and Arg506 but not further defined. OBJECTIVE: To identify and characterize the additional APC cleavage sites in FVa. METHODS: The cDNA for FV-306Q/506Q/679Q was used as a template to create FV variants with one or more possible cleavage sites being mutated. The FV variants were expressed and their sensitivity for APC characterized functionally and with Western blotting. RESULTS: The additional APC cleavage sites were located at Lys309, Arg313, Arg316, Arg317 and Arg505. FVa 306Q/309Q/313Q/316Q/317Q/505Q/506Q/679Q (denoted 8M-FVa) was APC resistant. To investigate individual sites, they were mutated back using 8M-FV as a template. The kinetics of APC-degradation of these variants demonstrated that protein S was equally efficient in enhancing the APC effect for all the novel sites. CONCLUSIONS: Multiple APC-cleavage sites close to Arg306 and a single site close to Arg506 were identified. Protein S was equally efficient as APC cofactor for all novel sites. The stimulation by protein S of the Arg505 cleavage argues against a specific protein S-mediated stimulation of cleavage at Arg306 due to relocation of the APC active site closer to the membrane. PMID- 19874464 TI - The platelet glycoprotein Ib-IX-V complex anchors lipid rafts to the membrane skeleton: implications for activation-dependent cytoskeletal translocation of signaling molecules. AB - BACKGROUND: The glycoprotein (GP) Ib-IX-V complex attaches platelets to areas of endothelial damage by binding von Willebrand factor (VWF), an interaction that transmits intracellular activation signals. These signals require that the complex associates with both lipid rafts and the membrane cytoskeleton, but it is not clear whether the same GPIb-IX-V subpopulation associates with both structures. OBJECTIVES: To determine which subpopulation of GPIb-IX-V associates with lipid rafts, and the consequences of that interaction. METHODS: We analyzed the content of proteins (particularly the GPIb-IX-V complex) and lipids in rafts from detergent lysates of platelets before and after removal of the actin cytoskeleton alone or both the actin cytoskeleton and membrane skeleton (by successive centrifugations of 15,800 x g and 100,000 x g). RESULTS: In unstimulated platelets, little raft-associated GPIb-IX-V sedimented with the actin skeleton; most was removed by sedimentation of the membrane skeleton. The Src family kinase Lyn followed the same pattern. In VWF-activated platelets, almost all of the GPIb-IX-V complex and Lyn in rafts sedimented with the actin cytoskeleton, consistent with a previously described crosslinking of the membrane and actin skeletal structures following platelet activation. Disruption of the GPIbalpha-filamin linkage with N-ethylmaleimide prevented depletion of raft associated GPIb-IX-V by skeletal sedimentation. Not all raft-associated proteins and lipids followed this pattern. CONCLUSION: These results suggest that the raft association and cytoskeletal linkage of the GPIb-IX-V complex are interrelated, and both are required for optimal receptor function, perhaps because raft association attracts signaling proteins and membrane skeletal association allows these proteins to move en masse to new locations. PMID- 19874465 TI - Thrombophilia and the risk of post-thrombotic syndrome: retrospective cohort observation. PMID- 19874466 TI - The decrease in procarboxypeptidase U (TAFI) concentration in acute ischemic stroke correlates with stroke severity, evolution and outcome. AB - BACKGROUND AND OBJECTIVES: Procarboxypeptidase U (proCPU, TAFI) concentration in plasma is potentially related to thrombotic tendency, and elevated proCPU levels have been reported in ischemic stroke patients. Improved insight into the role of proCPU in acute ischemic stroke is essential for the development of more adequate therapeutics that may include carboxypeptidase inhibitors. In this study we investigated whether the plasma concentration of proCPU and the proCPU kinetic profile in acute ischemic stroke are related to initial stroke severity, stroke evolution in the subacute phase and long-term stroke outcome. METHODS: Plasma concentration of proCPU was assessed in 136 stroke patients at admission (7.5 h after stroke onset), at 24 h, at 72 h and at day 7 after stroke onset. We evaluated the relation between change in proCPU concentrations and (a) stroke severity (patients with TIA vs. stroke patients, NIHSS score at admission), (b) stroke evolution (stroke progression, infarct volume at 72 h), and (c) stroke outcome (mRS score at month 3). RESULTS: ProCPU concentration decreased significantly in the first 72 h after stroke onset and thereafter returned to baseline. This biphasic time course, with its nadir at 72 h, was more pronounced in patients with severe stroke, unfavourable stroke evolution in the first 72 h and poor long-term outcome. CONCLUSIONS: The decrease in proCPU concentration in the first 72 h after stroke onset correlates with more severe stroke, unfavourable stroke evolution, and poor long-term stroke outcome. PMID- 19874468 TI - The prevalence of symptomatic von Willebrand disease in primary care practice. PMID- 19874467 TI - Cleaved high molecular weight kininogen inhibits tube formation of endothelial progenitor cells via suppression of matrix metalloproteinase 2. AB - BACKGROUND AND OBJECTIVE: Endothelial progenitor cells (EPCs) contribute to postnatal neovascularization, thus promoting wide interest in their therapeutic potential in vascular injury and prevention of their dysfunction in cardiovascular diseases. Cleaved high molecular weight kininogen (HKa), an activation product of the plasma kallikrein-kinin system (KKS), inhibits the functions of differentiated endothelial cells including in vitro and in vivo angiogenesis. In this study, our results provided the first evidence that HKa is able to target EPCs and inhibits their tube forming capacity. METHODS AND RESULTS: We determined the effect of HKa on EPCs using a three-dimensional vasculogenesis assay. Upon stimulation with vascular endothelial growth factor (VEGF) alone, EPCs formed vacuoles and tubes, and differentiated into capillary like networks. As detected by gelatinolytic activity assay, VEGF stimulated secretion and activation of matrix metallopeptidase 2 (MMP-2), but not MMP-9, in the conditioned medium of 3D culture of EPCs. Specific inhibition or gene ablation of MMP-2, but not MMP-9, blocked the vacuole and tube formation by EPCs. Thus, MMP-2 is selectively required for EPC vasculogenesis. In a concentration dependent manner, HKa significantly inhibited tube formation by EPCs and the conversion of pro-MMP-2 to MMP-2. Moreover, HKa completely blocked the association between pro-MMP-2 and alphavbeta3 integrin, and its inhibition of MMP 2 activation was dependent on the presence of alphavbeta3 integrin. In a purified system, HKa did not directly inhibit MMP-2 activity. CONCLUSIONS: HKa inhibits tube forming capacity of EPCs by suppression of MMP-2 activation, which may constitute a novel link between activation of the KKS and EPC dysfunction. PMID- 19874469 TI - Reduction in deep vein thrombosis incidence in intensive care after a clinician education program. AB - BACKGROUND: Deep vein thrombosis (DVT) is a major complication in intensive care units (ICU) but dedicated guidelines on its management are still lacking. OBJECTIVES AND METHODS: This study investigated the effect of a 1-year educational program for the implementation of DVT prophylaxis on the incidence of inferior limb DVT in a mixed-bed ICU that admits high-risk surgical and trauma patients, investigated during a first retrospective phase [126 patients, SAPS II score 42 (28-54)] and a following prospective phase [264 patients, SAPS II score II 41 (27-55)]. The role of baseline and time-dependent DVT risk factors in DVT occurrence was also investigated during the prospective phase. RESULTS: The educational program on implementation of DVT prophylaxis was associated with a significant decrease in DVT incidence from 11.9% to 4.5% (P < 0.01) and in the mean length of ICU stay (P < 0.01). Combined with pharmacological prophylaxis, the use of elastic compressive stockings significantly also increased in the prospective phase (P < 0.01). The duration of mechanical ventilation, vasopressor administration and neuromuscular block were significantly different between DVT positive and DVT-negative patients (P < 0.01). Multivariate analysis identified neuromuscular block as the strongest independent predictor for DVT incidence. CONCLUSION: One-year ICU-based educational programs on implementation of DVT prophylaxis were associated with a significant decrease in the incidence of DVT and also in the length of stay in ICU. PMID- 19874470 TI - Clinical course of high-risk patients diagnosed with antiphospholipid syndrome. AB - BACKGROUND: The characteristics and the clinical course of antiphospholipid syndrome (APS) in high-risk patients that are positive for all three recommended tests that detect the presence of antiphospholipid (aPL) antibodies have not been described. METHODS: This retrospective analysis of prospectively collected data examined patients referred to Italian Thrombosis Centers that were diagnosed with definite APS and tested positive for aPL [lupus anticoagulant (LA), anti cardiolipin (aCL), and anti-beta2-glycoprotein I (beta2GPI) antibodies]. Laboratory data were confirmed in a central reference laboratory. RESULTS: One hundred and sixty patients were enrolled in this cohort study. The qualifying events at diagnosis were venous thromboembolism (76 cases; 47.5%), arterial thromboembolism (69 cases; 43.1%) and pregnancy morbidity (11 cases; 9.7%). The remaining four patients (2.5%) suffered from catastrophic APS. The cumulative incidence of thromboembolic events in the follow-up period was 12.2% (95% CI, 9.6 14.8) after 1 year, 26.1% (95% CI, 22.3-29.9) after 5 years and 44.2% (95% CI, 38.6-49.8) after 10 years. This was significantly higher in those patients not taking oral anticoagulants as compared with those on treatment (HR=2.4 95% CI 1.3 4.1; P<0.003). Major bleeding associated with oral anticoagulant therapy was low (0.8% patient/years). Ten patients died (seven were cardiovascular deaths). CONCLUSIONS: Patients with APS and triple positivity for aPL are at high risk of developing future thromboembolic events. Recurrence remains frequent despite the use of oral anticoagulants, which significantly reduces the risk of thromboembolism. PMID- 19874471 TI - Mean platelet volume: a quick, easy determinant of thrombotic risk? PMID- 19874472 TI - Functional association of phosphoinositide-3-kinase with platelet glycoprotein Ibalpha, the major ligand-binding subunit of the glycoprotein Ib-IX-V complex. AB - BACKGROUND: The adhesion receptor glycoprotein (GP)Ib-IX-V, which binds von Willebrand factor (VWF) and other ligands, initiates platelet activation and thrombus formation at arterial shear rates, and may control other vascular processes, such as coagulation, inflammation, and platelet-mediated tumor metastasis. The cytoplasmic C-terminal domain of the ligand-binding GPIbalpha subunit contains binding sites for filamin (residues 561-572, critically Phe568/Trp570), 14-3-3zeta (involving phosphorylation sites Ser587/590 and Ser609), and the phosphoinositide-3-kinase (PI3-kinase) regulatory subunit, p85. OBJECTIVES: We previously showed that, as compared with wild-type receptor, deleting the contiguous sequence 580-590 or 591-610, but not upstream sequences, of GPIbalpha expressed as a GPIb-IX complex in Chinese hamster ovary cells inhibited VWF-dependent Akt phosphorylation, which is used as a read-out for PI3 kinase activity. Pulldown experiments using glutathione-S-transferase (GST)-p85 or GST-14-3-3zeta constructs, and competitive inhibitors of 14-3-3zeta binding, suggested an independent association of 14-3-3zeta and PI3-kinase with GPIbalpha. The objective of this study was to analyze a further panel of GPIbalpha deletion mutations within residues 580-610. RESULTS: We identified a novel deletion mutant, Delta591-595, that uniquely disrupts 14-3-3zeta binding but retains the functional p85/PI3-kinase association. Deletion of other sequences within the 580 610 region were less discriminatory, and either partially affected p85/PI3-kinase and 14-3-3zeta binding (Delta580-585, Delta586-590, Delta596-600, Delta601-605), or strongly inhibited binding of both proteins (Delta606-610). CONCLUSIONS: Together, these findings have significant implications for interpreting the functional role of p85 and/or 14-3-3zeta in GPIb-dependent signaling or platelet functional studies involving truncation of the C-terminal residues in cell-based assays and mouse models. The Delta591-595 mutation provides another strategy for determining the function of GPIbalpha-associated 14-3-3zeta by selective disruption of 14-3-3zeta but not p85/PI3-kinase binding. PMID- 19874473 TI - Human plasminogen kringle 1-5 reduces atherosclerosis and neointima formation in mice by suppressing the inflammatory signaling pathway. AB - BACKGROUND: Activation of vascular endothelial cells plays an important role in atherogenesis and plaque instability. Recent research has demonstrated that late stage inhibition of plaque angiogenesis by angiostatin (kringle 1-4) reduces macrophage accumulation and slows the progression of advanced atherosclerosis. Kringle 1-5 (K(1-5)) is a variant of angiostatin that contains the first five kringle domains of plasminogen. OBJECTIVE: To investigate whether K(1-5) has an inhibitory effect on early-stage atherosclerosis, using the apolipoprotein E (ApoE)-deficient mouse model and a carotid artery ligation model. METHODS: ApoE deficient mice received K(1-5) treatment for 4 weeks, and the severity of aortic atherosclerosis was measured. In the ligation model, the left common carotid arteries of C57BL/6 mice were ligated near the carotid bifurcation, and the mice received K(1-5) for 4 weeks. Human umbilical vein endothelial cells were pretreated with K(1-5) before tumor necrosis factor-alpha (TNF-alpha) treatment to explore the anti-inflammatory effect of K(1-5). RESULTS: The areas of the lesion in the aortas of ApoE-deficient mice that received K(1-5) treatment were notably decreased, and the formation of carotid neointima in the C57BL/6 mice was decreased by treatment with K(1-5). Expression of TNF-alpha-induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 was inhibited by K(1-5) treatment, possibly via downregulation of translocation of nuclear factor-kappaB and expression of reactive oxygen species. CONCLUSIONS: K(1-5) reduced atherosclerosis and neointima formation in mice, possibly through inhibition of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression in endothelial cells. PMID- 19874475 TI - Prediction of the warfarin maintenance dose after completion of the 10 mg initiation nomogram: do we really need genotyping? AB - INTRODUCTION: Initiation of warfarin therapy is complicated by its narrow therapeutic index and inter-patient dose-effect variability. A '10-mg nomogram' warfarin initiation protocol permits safe therapeutic anticoagulation in outpatients started on warfarin. We aimed to develop a safe and effective warfarin maintenance dose prediction tool in these patients. METHODS: Baseline potential predictor variables were collected on a retrospective cohort of outpatients initiated on warfarin for venous thromboembolism treatment. The primary outcome was the warfarin maintenance dose, defined as mean warfarin dose over the last 10 days of the first month of warfarin treatment. Univariate and multivariate analyses were performed to determine which baseline variables were warfarin maintenance dose predictors. An independent cohort of patients validated the derived warfarin maintenance dose prediction rule. RESULTS: Patient's age and weight, cumulative dose of warfarin over the first week of induction and international normalized ratio (INR) on days 3, 5 and 8 were statistically significant predictors of the warfarin maintenance dose. Our final prediction rule reads: maintenance dose (in mg) = 2.5 + 10% of the first week cumulative dose - INR value at day 8 + 1.5 if INR was below 2.0 at day 5. In the validation cohort, the predicted dose was strongly correlated with the actual maintenance dose (r = 0.88, P < 0.0001). The mean difference between observed and predicted dose was not clinically significant: -0.1 +/- 1.1 mg. CONCLUSION: In outpatients initiated on warfarin using a '10-mg nomogram', a simple prediction rule can accurately predict warfarin maintenance dose. Prospective studies employing the rule are indicated. PMID- 19874474 TI - Ability of VKORC1 and CYP2C9 to predict therapeutic warfarin dose during the initial weeks of therapy. AB - BACKGROUND: CYP2C9 and VKORC1 genotypes predict therapeutic warfarin dose at initiation of therapy; however, the predictive ability of genetic information after a week or longer is unknown. Experts have hypothesized that genotype becomes irrelevant once international normalized ratio (INR) values are available because INR response reflects warfarin sensitivity. METHODS: We genotyped the participants in the Prevention of Recurrent Venous Thromboembolism (PREVENT) trial, who had idiopathic venous thromboemboli and began low-intensity warfarin (therapeutic INR 1.5-2.0) using a standard dosing protocol. To develop pharmacogenetic models, we quantified the effect of genotypes, clinical factors, previous doses and INR on therapeutic warfarin dose in the 223 PREVENT participants who were randomized to warfarin and achieved stable therapeutic INRs. RESULTS: A pharmacogenetic model using data from day 0 (before therapy initiation) explained 54% of the variability in therapeutic dose (R(2)). The R(2) increased to 68% at day 7, 75% at day 14, and 77% at day 21, because of increasing contributions from prior doses and INR response. Although CYP2C9 and VKORC1 genotypes were significant independent predictors of therapeutic dose at each weekly interval, the magnitude of their predictive ability diminished over time: partial R(2) of genotype was 43% at day 0, 12% at day 7, 4% at day 14, and 1% at day 21. CONCLUSION: Over the first weeks of warfarin therapy, INR and prior dose become increasingly predictive of therapeutic dose, and genotype becomes less relevant. However, at day 7, genotype remains clinically relevant, accounting for 12% of therapeutic dose variability. PMID- 19874476 TI - Activated factor X cleaves factor VIII at arginine 562, limiting its cofactor efficiency. AB - BACKGROUND: Factor VIII (FVIII) and its activated form (FVIIIa) are subject to proteolysis that dampens their cofactor function. Among the proteases that attack FVIII (activated factor X (FXa), activated protein C (APC) and plasmin), only APC cleaves within the FVIII A2 domain at R562 to fully abolish FVIII activity. OBJECTIVES: We investigated the possible involvement of the FXa cleavage at R562 within the A2 domain in the process of FVIII inactivation. METHODS: An antibody (GMA012/R8B12) that recognizes the carboxy-terminus extremity of the A2 domain (A2C) was used to evaluate FXa action. A molecule mutated at R562 was also generated to assess the functional role of this particular residue. RESULTS AND CONCLUSIONS: The appearance of the A2C domain as a function of time evidenced the identical cleavage within the A2 domain of FVIII and FVIIIa by FXa. This cleavage required phospholipids and occurred within minutes. In contrast, the isolated A2 domain was not cleaved by FXa. Von Willebrand factor and activated FIX inhibited the cleavage in a dose-dependent manner. Mutation R562K increased both the FVIII specific activity and the generation of FXa due to an increase in FVIII catalytic efficiency. Moreover, A2C fragment could not be identified from FVIII-R562K cleavage. In summary, this study defines a new mechanism for A2 domain-mediated FVIII degradation by FXa and implicates the bisecting of the A2 domain at R562. PMID- 19874477 TI - Prospective comparison of Fibroscan, King's score and liver biopsy for the assessment of cirrhosis in chronic hepatitis C infection. AB - Historically, liver biopsy (LB) was the sole method to evaluate the severity of hepatic fibrosis in patients with chronic hepatitis C infection. However, LB is expensive and associated with a risk of severe complications. Therefore, noninvasive tests have been developed to assess the severity of liver fibrosis. The accuracy of Fibroscan (FS) and King's score (KS) was evaluated individually and in combination using liver histology as the reference standard. One hundred and eighty-seven patients were identified who had undergone a biopsy with a diagnosis of chronic hepatitis C virus (HCV) mono-infection (HCV RNA-positive by RT-PCR), attending King's College Hospital (n = 88) or the Royal Free Hospital (n = 99) (London) between May 2006 and December 2007. Liver fibrosis was scored using the Ishak method; significant fibrosis was defined as Ishak fibrosis stage F3-F6, and cirrhosis defined as Ishak fibrosis F5-F6. The diagnostic accuracy of each test was assessed by area under receiver operator characteristic curves (AUROC). Median age was 49 years (43-54) and 115 (61%) were male. The AUROC for FS, KS and FS + KS for the diagnosis of Ishak F3-F6 were 0.83, 0.82 and 0.85, respectively and for the diagnosis of cirrhosis (>or=F5) were 0.96, 0.89 and 0.93, respectively. The negative predictive values for the diagnosis of cirrhosis using the optimal cut-off results for fibrsocan (10.05 kPa), KS (24.3) and the two combined (26.1) were 98%, 91% and 94%, respectively. The noninvasive markers and, particularly, FS were effective tests for the prediction of cirrhosis in chronic hepatitis C. Both KS and FS also had clinical utility for the prediction of Ishak fibrosis stages F3-F6. PMID- 19874478 TI - Hepatitis B viral load and risk for liver cirrhosis and hepatocellular carcinoma in The Gambia, West Africa. AB - The main objectives of this study were to define the occurrence and levels of hepatitis B virus (HBV) DNA in asymptomatic HBV carriers, cirrhosis patients and hepatocellular carcinoma (HCC) cases from The Gambia, and to evaluate the risk for cirrhosis or HCC associated with HBV viremia. We used sensitive real-time quantitative PCR assays to measure HBV DNA in samples from a case-control study consisting of 60 asymptomatic HBV carriers, 53 cirrhotic patients and 129 HCC cases. Logistic regression was used to estimate the risks of cirrhosis and HCC associated with HBV-DNA levels and HBV e antigenemia (HBeAg) detection (a surrogate marker for viral replication). Detectable HBV viremia and HBeAg positivity were both significantly associated with cirrhosis (increasing risk by fourfold and 11-fold respectively) and with HCC (increasing risk by sixfold and threefold respectively). HBV-DNA levels were significantly higher in both HCC cases and cirrhotic patients compared to asymptomatic carriers (P < 0.01 for both). High-level HBV DNA (>10,000 copies/mL) was strongly associated with both HCC and cirrhosis (17- and 39-fold increased risk). Lower level HBV viremia (200 10,000 copies/mL) conferred a significant risk of HCC, although the association with cirrhosis was not significant. In conclusion, we find that high HBV-DNA levels are strongly associated with the serious sequelae of HBV infection, independent of HBeAg status. While risk for cirrhosis and for HCC notably increases at HBV-DNA levels >or=10,000 copies/mL, low-level viremia was also associated with significant risk for HCC. PMID- 19874479 TI - Ratios between Alpha-, Beta- and Gamma-proteobacteria in tap water determined by the ProteoQuant assay. AB - AIMS: Proteobacteria are widespread on earth. Recently, it has been discovered that a diverse repertoire of proteobacteria are also dominant in tap water. It is therefore important to use high-throughput monitoring tools for tap water. Here, the high-throughput assay ProteoQuant was developed to quantify the main proteobacterial phyla in tap water. METHODS AND RESULTS: The principle of ProteoQuant is proteobacterial-selective 23S rRNA gene PCR amplification, with multiple competitive TaqMan probes for quantifying the phyla Alpha-, Beta- and Gamma-proteobacteria. The ProteoQuant assay was evaluated, analysing both designed proteobacterial mixes and rRNA gene clone libraries from tap water. These evaluations showed a good coverage and accuracy of the ProteoQuant assay. CONCLUSIONS: Large-scale tap water screening using ProteoQuant revealed a dominance of Beta-proteobacteria and a potential interaction between Alpha- and Beta-proteobacteria. Gamma-proteobacteria, on the other hand, seemed independent of the two other phyla. SIGNIFICANCE AND IMPACT OF THE STUDY: The ProteoQuant assay will potentially be important for future understanding of the ecological forces shaping the tap water microbiota. PMID- 19874480 TI - Rapid and sensitive detection of Vibrio cholerae by loop-mediated isothermal amplification targeted to the gene of outer membrane protein ompW. AB - AIMS: The present study was aimed to develop a loop-mediated isothermal amplification (LAMP) assay for rapid and specific detection of Vibrio cholerae. METHODS AND RESULTS: A set of five designed primers that recognized specifically the V. cholerae ompW gene was used. The optimized time and temperature conditions for the LAMP assay were 75 min at 65 degrees C, respectively. The LAMP method accurately identified 16 isolates of V. cholerae but did not detect 28 non cholerae Vibrio isolates and 37 non-Vibrio bacterial isolates. The sensitivity of LAMP for V. cholerae detection in pure cultures was 2.2 x 10(3) CFU ml(-1) or equivalent to 8 CFU per reaction. In the case of spiked shrimp samples without enrichment, the detection limit for V. cholerae was 2.2 x 10(4) CFU g(-1) or equivalent to 20 CFU per reaction, while that of PCR was 100 CFU per reaction. CONCLUSION: The developed LAMP assay targeting ompW gene was rapid, specific and sensitive for V. cholerae detection. SIGNIFICANT AND IMPACT OF THE STUDY: The developed LAMP assay appears to be precise, accurate and a valuable tool for detection of V. cholerae. This assay can replace laborious biochemical tests for the identification of V. cholerae in contaminated food sample. PMID- 19874481 TI - The in vitro antibiofilm activity of selected culinary herbs and medicinal plants against Listeria monocytogenes. AB - AIMS: The antibiofilm activity of extracts obtained from selected herbs, spices, beverages and commercially important medicinal plants was investigated on Listeria monocytogenes. METHODS AND RESULTS: The growth and development of the biofilm was assessed using the crystal violet (CV) assay. The respiratory activity was assessed using the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H tetrazolium-5-carboxanilide (XTT) reduction assay. The majority of extracts tested prevented cell adhesion to the polyvinyl chloride (PVC) surface. Seven of the 15 extracts reduced biofilm adhesion of both the clinical and the type strains by at least 50%. In contrast, inhibition of a preformed biofilm was more difficult to achieve, with only three extracts (Rosmarinus officinalis, Mentha piperita and Melaleuca alternifolia) inhibiting the growth of both strains by at least 50%. CONCLUSIONS: Although most extracts were able to reduce initial cell attachment, inhibition of growth in a preformed biofilm was more difficult to achieve. SIGNIFICANCE AND IMPACT OF THE STUDY: The ability to reduce biofilm biomass as shown by several plant extracts warrants further investigation to explore the use of natural products in antibiofilm adhesion. PMID- 19874482 TI - Identification of coliform genera recovered from water using different technologies. AB - AIMS: Methods for the detection of coliforms in water have changed significantly in recent years with procedures incorporating substrates for the detection of beta-d-galactosidase becoming more widely used. This study was undertaken to determine the range of coliform genera detected with methods that rely on lactose fermentation and compare them to those recovered using methods based upon beta-d galactosidase. METHODS AND RESULTS: Coliform isolates were recovered from sewage polluted water using m-endo, membrane lauryl sulfate broth, tergitol TTC agar, Colilert-18, ChromoCult and ColiScan for primary isolation. Organisms were grouped according to whether they had been isolated based upon lactose fermentation or beta-d-galactosidase production. CONCLUSIONS: A wide range of coliform genera were detected using both types of methods. There was considerable overlap between the two groups, and whilst differences were seen between the genera isolated with the two method types, no clear pattern emerged. Substantial numbers of 'new' coliforms (e.g. Raoutella spp.) were recovered using both types of methods. SIGNIFICANCE AND IMPACT OF THE STUDY: The results presented here confirm that both methods based on lactose fermentation or detection of beta-d galactosidase activity recover a range of coliform organisms. Any suggestion that only methods which are based upon fermentation of lactose recover organisms of public health or regulatory significance cannot be substantiated. Furthermore, the higher recovery of coliform organisms from sewage-polluted water using methods utilizing beta-d-galactosidase-based methods does not appear to be because of the recovery of substantially more 'new' coliforms. PMID- 19874483 TI - Panose, a new prebiotic candidate. AB - AIMS: To investigate the prebiotic potential of two novel candidates, sophorose and panose, with in vitro methods. METHODS AND RESULTS: The growth of single microbial strains was first assessed for both substrates in pure cultures, and panose was further analysed in the simulated colon model with mixed human faecal culture. Quantitative PCR and flow cytometry were used to determine the microbial group and strain densities after the simulated colonic fermentation of panose, and chromatographic methods were utilized to analyse metabolite concentrations. In pure cultures, sophorose and panose were both fermented only by few beneficial strains, and in the colon simulator, panose gave a significant increase in the numbers of Bifidobacterium and Bifidobacterium lactis, concomitantly decreasing Bacteroides group. Butyrate and acetate production was significantly increased together with decreased markers of protein fermentation as a result of panose fermentation. CONCLUSIONS: Panose had bifidogenic activities in vitro, and these potential beneficial effects should be further assessed in vitro and in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study has provided the first data on pure panose fermentation by the endogenous microbiota and extends our knowledge of the selective fermentation of oligosaccharides by the intestinal microbes. PMID- 19874484 TI - Inhibitory effects of Bacillus probionts on growth and toxin production of Vibrio harveyi pathogens of shrimp. AB - AIM: To investigate the effects of Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium in terms of toxin and growth of pathogenic Vibrio harveyi. METHODS AND RESULTS: Three Bacillus probionts were isolated from probiotic BZT aquaculture and identified using a 16S rDNA sequence. Growth inhibition assay showed that supernatants from the 24-h culture of three Bacillus species were able to inhibit the growth of V. harveyi (LMG 4044); B. subtilis was the most effective based on the well diffusion method. Results of a liquid culture model showed that B. subtilis was also widely effective in inhibiting three strains of V. harveyi (isolated from Thailand, the Philippines and LMG 4044), and that both B. licheniformis and B. megaterium inhibit the growth of V. harveyi isolated from the Philippines. Moreover, a haemolytic activity assay demonstrated that V. harveyi (IFO 15634) was significantly decreased by the addition of B. licheniformis or B. megaterium supernatant. CONCLUSIONS: Bacillus subtilis inhibited Vibrio growth, and both B. licheniformis and B. megaterium suppressed haemolytic activity in Vibrio. SIGNIFICANCE AND IMPACT OF THE STUDY: The cell free supernatants produced by Bacillus probionts inhibit Vibrio disease, and Bacillus probionts might have an influence on Vibrio cell-to-cell communications. PMID- 19874485 TI - The zymocidial activity of Tetrapisispora phaffii in the control of Hanseniaspora uvarum during the early stages of winemaking. AB - AIMS: The yeast strain Tetrapisispora phaffii DBVPG 6706 (formerly Kluyveromyces phaffii) secretes a killer toxin (Kpkt) that has antimicrobial activity against apiculate yeasts. The aim of this study was to evaluate the killer activity of Kpkt towards Hanseniaspora uvarum under winemaking conditions. METHODS AND RESULTS: The zymocidial activity of Kpkt on H. uvarum was assayed in microfermentation trials inoculated with free and immobilized T. phaffii cells. The microbial evolution and fermentation profiles of the wines were evaluated to determine the effects of Kpkt on apiculate yeasts, in comparison with SO(2). The results indicate that the fungicidal activity of Kpkt against H. uvarum is stable for at least 14 days in wine, and the zymocin can control the proliferation of apiculate yeasts. The analytical composition of wines with the inoculum of T. phaffii immobilized cells did not differ from the wines with SO(2). In contrast to wines without this control of apiculate yeasts, an increase in ethyl acetate was seen. CONCLUSIONS: Tetrapisispora phaffii is an excellent candidate for the biological control of undesired proliferation of apiculate yeasts during the first steps of fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: Tetrapisispora phaffii cells in an immobilized form can be used as a biocontrol agent to reduce the need for SO(2) addition. PMID- 19874486 TI - The use of chromogenic bacteria as coloured substitutes for pathogens: a simple strategy during design and development of a new method for sample pretreatment. AB - AIMS: In the present study, chromogenic (red) bacteria were used to simulate actual target bacteria during set-up and optimization of an isolation process of bacteria, designed for food samples. Isolation of bacteria from food in the context of molecular biological detection of food pathogens is a multistep process. Development of such a separation method requires continuous monitoring of the location of the presumable targets in the sample tubes. Therefore, red coloured pigmented bacteria were used as substitutes for the actual target bacteria, during the establishment of a new sample preparation technique. METHODS AND RESULTS: The chromogenic bacteria Micrococcus roseus and Serratia marcescens were confirmed to withstand the physical (e.g. centrifugal forces) and chemical (e.g. lysis buffer composition) conditions required during establishment of the new technique. Furthermore, the suitability of these model bacteria to substitute for the actual target pathogens (Salmonella enterica subsp. enterica serovar Typhimurium and Listeria monocytogenes) was assured by testing the physical properties of the model bacteria with respect to the proposed separation methods. CONCLUSION: Visibility of the pigmented bacteria within the complex sample matrices served to allocate bacterial content during the various steps necessary for finalization of the method protocol. The presumptive bacterial targets can be allocated simply by visualization of their bright red colour silhouetted against the background sample matrix. SIGNIFICANCE AND IMPACT OF STUDY: The use of pigmented bacteria as substitutes for actual colourless target bacteria during design and development of a bacterial isolation method is a simple and inexpensive application. It saves a huge amount of time and resources, as the proof of principle of new methods is possible in rapid succession. PMID- 19874487 TI - Legionella in industrial cooling towers: monitoring and control strategies. AB - AIMS: Legionella contamination of industrial cooling towers has been identified as the cause of sporadic cases and outbreaks of legionellosis among people living nearby. To evaluate and control Legionella contamination in industrial cooling tower water, microbiological monitoring was carried out to determine the effectiveness of the following different disinfection treatments: (i) continuous chlorine concentration of 0.01 ppm and monthly chlorine shock dosing (5 ppm) on a single cooling tower; (ii) continuous chlorine concentration of 0.4 ppm and monthly shock of biocide P3 FERROCID 8580 (BKG Water Solution) on seven towers. METHODS AND RESULTS: Legionella spp. and total bacterial count (TBC) were determined 3 days before and after each shock dose. Both strategies demonstrated that when chlorine was maintained at low levels, the Legionella count grew to levels above 10(4) CFU l(-1) while TBC still remained above 10(8 )CFU l(-1). Chlorine shock dosing was able to eliminate bacterial contamination, but only for 10-15 days. Biocide shock dosing was also insufficient to control the problem when the disinfectant concentration was administered at only one point in the plant and at the concentration of 30 ppm. On the other hand, when at a biocide concentration of 30 or 50 ppm was distributed throughout a number of points, depending on the plant hydrodynamics, Legionella counts decreased significantly and often remained below the warning limit. Moreover, the contamination of water entering the plant and the presence of sediment were also important factors for Legionella growth. CONCLUSIONS: For effective decontamination of outdoor industrial cooling towers, disinfectants should be distributed in a targeted way, taking into account the possible sources of contamination. SIGNIFICANCE AND IMPACT OF THE STUDY: The data of the research permitted to modify the procedure of disinfection for better reduce the water and aerosol contamination and consequently the exposure risk. PMID- 19874488 TI - Development of a minimal growth medium for Lactobacillus plantarum. AB - AIM: A medium with minimal requirements for the growth of Lactobacillus plantarum WCFS was developed. The composition of the minimal medium was compared to a genome-scale metabolic model of L. plantarum. METHODS AND RESULTS: By repetitive single omission experiments, two minimal media were developed: PMM5 (true minimal medium) and PMM7 [a pseudominimal medium, supporting proper biomass formation of 350 mg l(-1) dry weight (DW)]. The specific growth rate of L. plantarum on PMM7 was found to be 50% and 63% lower when compared to growth on established growth media (chemically defined medium and MRS, respectively). Using a genome-scale metabolic model of L. plantarum, it was predicted that PMM5 and PMM7 would not support the growth of L. plantarum. This is because the biosynthesis of para aminobenzoic acid (pABA) was predicted to be essential for growth. The discrepancy in simulated growth and experimental growth on PMM7 was further investigated for pABA; a molecule which plays an important role in folate production. The growth performance and folate production were determined on PMM7 in the presence and absence of pABA. It was found that a 12,000-fold reduction in folate pools exerted no influence on formation of biomass or growth rate of L. plantarum cultures when grown in the absence of pABA. CONCLUSION: Largely reduced folate production pools do not have an effect on the growth of L. plantarum, showing that L. plantarum makes folate in a large excess. SIGNIFICANCE AND IMPACT OF THE STUDY: These experiments illustrate the importance of combining genome scale metabolic models with growth experiments on minimal media. PMID- 19874489 TI - Deleted in liver cancer 1 isoforms are distinctly expressed in human tissues, functionally different and under differential transcriptional regulation in hepatocellular carcinoma. AB - BACKGROUND: Deleted in liver cancer (DLC) is a family of tumour suppressors that plays a critical role in hepatocellular carcinoma (HCC). AIMS: This study aimed to document the expression profiles of the three known DLC1 isoforms (alpha, beta and gamma) in normal human tissues and human HCCs and address their functional and regulatory differences. We also aimed to determine the clinicopathological and prognostic significance of the DLC1 dominant isoform in human HCCs. METHODS: Quantitative polymerase chain reaction was performed to determine the expressions of DLC1 isoforms in different normal human tissues and human HCCs. The clinicopathological and prognostic significance of DLC1 expression in HCC samples was also analysed. In addition, the functional roles of DLC1 isoforms were addressed using HCC cell lines to examine their abilities to suppress stress fibre formation and HCC cell growth. RESULTS: DLC1alpha was the most predominant of the three isoforms in the normal human tissues examined, except the heart. The DLC1alpha promoter, but not the DLC1beta and gamma promoter, was hypermethylated and epigenetically silenced in HCC cells. Underexpression of DLC1alpha at the mRNA level was frequently (52.5%, n=52) observed in the 99 HCCs as compared with the corresponding nontumorous liver tissues. DLC1alpha underexpression correlated with poorer tumour cellular differentiation (P=0.010). Functionally, DLC1alpha and beta, but not DLC1gamma, were localized at focal adhesions of cells and able to inhibit stress fibre formation and suppress HCC cell growth. CONCLUSIONS: The results suggested that DLC1 isoforms are differentially expressed in human tissues, have different epigenetic transcriptional regulations and are functionally different. DLC1alpha was underexpressed and clinically relevant in human HCCs. PMID- 19874490 TI - Evaluation of acoustic radiation force impulse elastography for fibrosis staging of chronic liver disease: a pilot study. AB - BACKGROUND: Acoustic radiation force impulse (ARFI) is a new technology integrated into conventional B-mode ultrasonography. ARFI is used to evaluate tissue stiffness in several organs, but this method has not been applied for liver fibrosis. AIM: The aim of this study was to determine whether ARFI elastography is useful for the evaluation of liver fibrosis. METHODS: This study enrolled 55 consecutive patients with chronic liver disease who underwent a liver biopsy for histological assessment of liver fibrosis by the Metavir scoring system. Liver stiffness of the 55 patients and 25 healthy volunteers was evaluated by ARFI elastography and was expressed as the shear wave velocity. Cut off values were determined using receiver-operating characteristic (ROC) curves. RESULTS: Histological liver fibrosis was evaluated by Metavir scoring; F0: six cases, F1: 14 cases, F2: nine cases, F3: nine cases and F4: 17 cases. Liver stiffness determined by ARFI elastography was correlated with histological liver fibrosis (P<0.0001). The areas under the ROC curves were 0.94 (95% confidence intervals, 0.87-0.99) for F2-F4, 0.94 (0.88-0.99) for F3-F4 and 0.96 (0.91-1.01) for F4. The cut-off values of the shear wave velocity were as follows: >1.34 m/s for F2-F4 (sensitivity 91.4%, specificity 80%); >1.44 m/s for F3-F4 (sensitivity 96.2%, specificity 79.3%); and >1.80 m/s for F4 (sensitivity 94.1%, specificity 86.8%). CONCLUSIONS: Ultrasonic ARFI elastography is a novel, non-invasive and reliable method for the assessment of liver fibrosis in patients with chronic liver disease. PMID- 19874491 TI - The outcomes of pregnancy in patients with cirrhosis: a population-based study. AB - BACKGROUND: The outcomes of pregnancy in patients with cirrhosis are poorly described. Our objective was to assess obstetric outcomes in cirrhotic women and their infants from a population-based perspective. METHODS: We analysed the 1993 2005 US Nationwide Inpatient Sample database to identify obstetric hospitalizations among patients with cirrhosis (n=339) and controls matched on age, hospital and year (n=6625). The effect of cirrhosis on maternal and fetal outcomes was evaluated using regression models with adjustment for patient and hospital factors. RESULTS: Between 1993 and 2005, 114 antepartum and 225 delivery admissions in cirrhotic patients were identified. The estimated mean number of deliveries nationwide increased from 68 to 106 annually between 1993 and 1999 and 2000 and 2005 (P=0.0004). Patients with cirrhosis were more likely to deliver by caesarean [42 vs. 28%; adjusted odds ratio (OR) 1.41; 95% confidence interval (CI) 1.06-1.88]. Maternal (1.8 vs. 0%; P<0.0001) and fetal mortality (5.2 vs. 2.1%; P<0.0001), antepartum admission (OR 2.97; 95% CI 2.24-3.96), and maternal (OR 2.03; 95% CI 1.60-2.57) and fetal complications (OR 3.66; 95% CI 2.74-4.88) were greater among cirrhotic patients than controls. Gestational hypertension, placental abruption and uterovaginal haemorrhage were more common in patients with cirrhosis; their infants had higher rates of prematurity and growth restriction. Hepatic decompensation occurred in 15%, including ascites in 11% and variceal haemorrhage in 5%. In women with decompensation, maternal and fetal mortality were 6 and 12% respectively. CONCLUSIONS: Although rare, pregnancies among women with cirrhosis are increasing. Cirrhotic patients and their infants have an increased risk of obstetric complications, emphasizing the importance of close maternal-fetal monitoring during pregnancy. PMID- 19874493 TI - Medical education: striving for mediocrity? PMID- 19874494 TI - Conceptualising and classifying validity evidence for simulation. AB - CONTEXT: The term 'validity' is used pervasively in medical education, especially as it relates to curriculum, assessment, measurement and instrumentation. Exactly what is meant by the term 'validity' in the medical education literature is not always clearly defined. OBJECTIVES: This study attempts to clarify, conceptualise and classify how validity fits within the context of assessment and to provide a framework for medical educators to determine the type and degree of validity evidence required for their specific assessment and evaluation needs. METHODS: We apply a structure for considering validity, and its association with validation, in medical education. We build this discussion around the use of simulation in medical training because of its rapid growth as a foundation for numeric measurement of performance in the development of clinical skills and reasoning. We explain why validity is inextricably tied to the assessment process in both simulation-based medical training and traditional medical education. RESULTS: This logical framework structures the type and degree of validity evidence for various assessment and evaluation needs. We also provide an example for medical educators to reference and follow in collecting and reviewing their own needs for validity evidence in all aspects of medical education. CONCLUSIONS: Assessment is integral to measurement and decision making in medical education. The implications of assessment results are variably dependent on the inferences and decisions made from them. As such, validity evidence is critical, but is also flexibly tied to those decisions and not all assessments require the same degree of validity rigor. The framework described herein reinforces a model for medical educators to use in developing their assessment and evaluation needs and associated requirements for validity evidence. PMID- 19874495 TI - When only the real thing will do: junior medical students' learning from real patients. AB - OBJECTIVES: This study aimed to explore how medical students experience contacts with real patients and what they learn from them. METHODS: We carried out a post hoc, single-group study in one teaching sector of a 5-year, problem-based, horizontally integrated, outcome-based and community-oriented undergraduate programme, in which students lacked clinical exposure in the pre-clerkship phase. Subjects comprised five cohorts of students on their first clerkships. Data consisted of purposively selected, voluntary, self-report statements regarding real patient learning (RPL). Constant comparative analysis was performed by two independent researchers. RESULTS: Respondents valued patients as an instructional resource that made learning more real. They reported learning through visual pattern recognition as well as through dialogue and physical examination. They more often used social than professional language to describe RPL. They reported affective outcomes including enhanced confidence, motivation, satisfaction and a sense of professional identity. They also reported cognitive outcomes including perspective, context, a temporal dimension, and an appreciation of complexity. Real patient learning helped respondents link theory learned earlier with reality as represented by verbal, visual and auditory experiences. It made learning easier, more meaningful and more focused. It helped respondents acquire complex skills and knowledge. Above all, RPL helped learners to remember subject matter. Most negative responses concerned the difficulty of acquiring appropriate experience, but RPL made a minority of respondents feel uncomfortable and incompetent. CONCLUSIONS: Real patient learning led to a rich variety of learning outcomes, of which at least some medical students showed high metacognitive awareness. Sensitivity from clinical mentors towards the positive and negative outcomes of RPL reported here could support reflective clinical learning. PMID- 19874496 TI - Do medical students correctly perceive what patients believe about their own health? AB - OBJECTIVE: This study set out to estimate the prevalence of any mismatch between medical students' perceptions of patients' health beliefs and those of a normative group of primary care patients. METHODS: A Perception of Health Scale, normed on 314 primary care patients and including four reproducible subscales based on Health Belief Model constructs, was distributed to 500 medical students in Years 3 and 4 at a private US medical school. The students were asked to indicate how a 'typical' patient they had seen with a preceptor or on a rotation might have answered. Responses were scored as matching or not matching the normative data. Group comparisons were made for gender, year of graduation, age and planned specialty. RESULTS: Depending on the subscale, at least 75% of the students' responses did not match those of the normative patient group. There were no consistent group differences. CONCLUSIONS: The findings suggest that medical students do not accurately perceive what patients believe about their own health. Whether this is true for residents and providers in practice remains unknown. PMID- 19874497 TI - Indigenous Australian medical students' perceptions of their medical school training. AB - CONTEXT: The Australian Medical Council requires all accredited Australian medical schools to have specific admission and recruitment policies for Indigenous Australian students. However, there is no clear evidence about how these students can be retained through to graduation. OBJECTIVES: This study aimed to explore the training experiences of Indigenous undergraduate medical students and their perceptions of the factors influencing their progression through training. Methods We used a qualitative methodology involving focus groups. All participants had successfully completed at least 1 year of the Bachelor of Medicine programme at the University of Newcastle, New South Wales, Australia. RESULTS: Sixteen of 18 eligible students participated in the study. The factors that influence an Indigenous student's progress through medical training are multi-faceted and inter-related and are associated with student support, course content and styles of learning, personal qualities (such as confidence and coping skills), discrimination and distinctive cultural issues pertinent to Indigenous students. CONCLUSIONS: Both academic and non-academic factors affect the progression through training of Indigenous medical students. A number of individual and systemic interventions which actively encourage a range of support networks, increase confidence and coping skills, and reduce cultural clash by assertively addressing discrimination and stereotyping need to be introduced. The outcomes of this work may provide some guidance to medical schools engaged in implementing strategies to enroll and support Indigenous students. PMID- 19874498 TI - Medical training and the hospital at night: an oxymoron? AB - CONTEXT: Attempts to reduce doctors' working hours and streamline postgraduate medical training may mean junior doctors' out-of-hours experience is reduced. It is also proposed that, in the UK, compulsory clinical (Foundation Programme) competencies are to be accomplished in 1 year rather than 2 years as they are at present. This observational study was performed to examine the scope of opportunity available to junior doctors to achieve such competencies while working on a 'Hospital at Night' (H@N) team. METHODS: A database of electronic requests made to the H@N team was used to tabulate the number and type of tasks requested and to define differences between specialties, using local hospital admissions rates to contextualise the data. These requests were then compared with a list of compulsory clinical competencies to assess the scope of opportunity available to trainees to achieve these competencies when working on the H@N team. RESULTS: A total of 8268 referrals were made to our H@N team between 1 October 2007 and 31 January 2008 using the electronic Hospital Information System (HIS). The predefined, online HIS request list included eight of the 20 tasks that represent compulsory competencies and showed that on average there were 247 opportunities per week of night shifts to perform them. Medical wards generated more requests than surgical wards (4767 versus 3170) and afforded greater opportunity to attain compulsory competencies (139 opportunities/week versus 96 opportunities/week; extra requests could not be attributed to either medical or surgical wards as original request did not include ward number). CONCLUSIONS: The H@N initiative provides adequate opportunities for junior doctors to attain important clinical (Foundation) competencies. There appears to be sufficient opportunity to achieve these competencies within 1 year rather than the 2 years currently allowed in the UK Foundation Programme. PMID- 19874499 TI - Comparison of trait and ability measures of emotional intelligence in medical students. AB - CONTEXT: Emotional intelligence (EI), the ability to perceive emotions in the self and others, and to understand, regulate and use such information in productive ways, is believed to be important in health care delivery for both recipients and providers of health care. There are two types of EI measure: ability and trait. Ability and trait measures differ in terms of both the definition of constructs and the methods of assessment. Ability measures conceive of EI as a capacity that spans the border between reason and feeling. Items on such a measure include showing a person a picture of a face and asking what emotion the pictured person is feeling; such items are scored by comparing the test-taker's response to a keyed emotion. Trait measures include a very large array of non-cognitive abilities related to success, such as self-control. Items on such measures ask individuals to rate themselves on such statements as: 'I generally know what other people are feeling.' Items are scored by giving higher scores to greater self-assessments. We compared one of each type of test with the other for evidence of reliability, convergence and overlap with personality. METHODS: Year 1 and 2 medical students completed the Meyer-Salovey-Caruso Emotional Intelligence Test (MSCEIT, an ability measure), the Wong and Law Emotional Intelligence Scale (WLEIS, a trait measure) and an industry standard personality test (the Neuroticism-Extroversion-Openness [NEO] test). RESULTS: The MSCEIT showed problems with reliability. The MSCEIT and the WLEIS did not correlate highly with one another (overall scores correlated at 0.18). The WLEIS was more highly correlated with personality scales than the MSCEIT. CONCLUSIONS: Different tests that are supposed to measure EI do not measure the same thing. The ability measure was not correlated with personality, but the trait measure was correlated with personality. PMID- 19874500 TI - Emotional intelligence in medical students: does it correlate with selection measures? AB - CONTEXT: Much attention and emphasis are placed on the selection of medical students. Although selection measures have been validated in the literature, it is not yet known whether high scores at selection are indicative of high levels of interpersonal aptitude. Emotional intelligence (EI) is reported to be a predictor of the interpersonal and communications skills medical schools are looking for in applicants. OBJECTIVES: This study describes EI scores in medical students and explores correlations between EI and selection scores at the University of Western Australia. METHODS: Senior medical students from a 6-year undergraduate curriculum completed the online MSCEIT (Mayer-Salovey-Caruso Emotional Intelligence Test) survey. Scores for EI were described and correlations between EI and Undergraduate Medicine and Health Sciences Admission Test (UMAT), Interview and Tertiary Entrance Rank (TER) scores were analysed. RESULTS: Mean scores of the 177 respondents (58%) reflected the normal distribution of scores (mean 98, standard deviation [SD] 15.0) in the general population. Males had higher EI scores than females and Asian students demonstrated higher EI Total and branch scores than White students. The highest and lowest EI scores were obtained for the branches Understanding Emotions (mean 110, SD 19.0) and Perceiving Emotions (mean 94, SD 15.6), respectively. No significant correlations were found between EI Total or EI branch scores and any of the selection scores (UMAT, TER and Interview). DISCUSSION: This study offers information that can be used to compare the EI scores of medical students with those of other health professionals. No relationship was identified between cognition (measured by the UMAT) and skill (measured by the MSCEIT) in the interpersonal domain and EI. Further studies are required to explore whether UMAT Section 2 is measuring EI, if there are associations between EI and academic performance and if EI can be used to predict the performance of junior doctors. PMID- 19874501 TI - Lost at sea: anatomy teaching at undergraduate and postgraduate levels. PMID- 19874502 TI - Global choices: international health and medical student residency preferences. PMID- 19874505 TI - Fostering education scholarship: the mentored research group. PMID- 19874506 TI - Phlebotomy training for patient attendants in Malawi. PMID- 19874507 TI - Panel advising: an alternative to consider. PMID- 19874508 TI - Introducing microteaching sessions in an Indian medical school. PMID- 19874509 TI - Guiding undergraduate medical students to use literature appropriately. PMID- 19874510 TI - Performance-based stratified grouping to enhance peer learning. PMID- 19874511 TI - Using the 'transect walk' as a public health teaching and learning tool. PMID- 19874512 TI - Attracting health professional students to substance abuse research. PMID- 19874513 TI - Nested peer tutoring in clinical reasoning. PMID- 19874514 TI - Training deaf persons as standardised patients. PMID- 19874515 TI - An innovative method of teaching clinical therapeutics through role-play. PMID- 19874516 TI - Feasibility of an evidence-based medicine educational prescription. PMID- 19874517 TI - The BigSib students' peer group mentoring programme. PMID- 19874518 TI - A genethics debate within an interdisciplinary curriculum. PMID- 19874519 TI - A questionnaire on the quality of life of medical students. PMID- 19874520 TI - Experiences from a medical students' well-being workshop. PMID- 19874521 TI - Teaching transplantation ethics to final-year medical students. PMID- 19874522 TI - When medicine was a foreign language. PMID- 19874523 TI - What standardised patients tell us about 'activating' patients. PMID- 19874524 TI - Moodle platform for online tutoring during internships. PMID- 19874525 TI - Shortening distances: a Moodle platform supports programme evaluation in internship. PMID- 19874526 TI - Wiki use and challenges in undergraduate medical education. PMID- 19874527 TI - How active are American adolescents and have they become less active? AB - The aim of this study was to systematically examine patterns and time trends in US adolescents' physical activity (PA) and sedentary behaviours. We examined findings from the nationally representative Youth Risk Behavior Surveillance Surveys during 1991-2007, and fit regression models estimating average annual changes and tested time trends, and age, gender and ethnic differences. US adolescents had less PA but more sedentary behaviours than recommended, but showed no clear evidence of becoming less active. In 2007, 24.9% reported on average spending >=3 h of screen time per day for non-school work; only 34.7% met the current PA recommendations, and it (25.6%) was even lower in girls. The prevalence of having sufficient vigorous PA changed little between 1993 and 2005 (from 65.8% to 64.1%). Encouraging changes regarding TV viewing time and physical education (PE) were detected. PE daily attendance rate and exercising >20 min during an average PE class increased significantly, while watching TV >=3 h d-1 decreased significantly in recent years. Considerable sex, age and ethnic differences existed in the patterns and trends. These national data show no clear evidence of declining PA among US adolescents in recent years. Reduced PA is not likely the major explanation of the recent increase in obesity among US adolescents. PMID- 19874528 TI - Screening for body-weight disorders in Nigerian children using contrasting definitions. AB - Several indices for body-weight disorders exist in scientific literature, but it is inconclusive whether or not they can yield comparable results when applied to Nigerian children. The prevalence of weight disorders in Nigerian children was examined using the Centre for Disease Control and Prevention (CDC) body mass index (BMI) for age charts and the International Obesity Task Force's (IOTF) age- and sex-specific BMI cut-off points. Participants were 2015 pupils (979 boys and 1036 girls) aged 9-12 years, attending 19 public primary schools in Makurdi, Nigeria. Stature and body mass were measured using standard techniques. Results were analysed using student t-test and Chi-squared statistics, with the probability level set at or = 30 years) during a 20-year period. Data were derived from two cross sectional nationally representative surveys (n = 13 844) in 1978-1980 and 2000 2001. Weight and height were measured using a standardized protocol. Obesity was defined as body mass index (BMI) > or = 30 kg m(-2). Cut-offs of BMI > or = 35 kg m(-2) and BMI > or = 40 kg m(-2) were also used. A 20-year difference in the prevalence of obesity was from 11.3% to 20.7% in men and from 17.9% to 24.1% in women. In 1978-1980, 1.1% of men and 3.8% of women had a BMI at least 35 kg m( 2). The corresponding prevalence was 3.9% in men and 6.8% in women 20 years later. The educational gradient in obesity diminished in 20 years because of the most prominent increase among highly educated men. Yet, 25% of men and 28% of women with low education are obese. Obesity increased in all age and educational groups over the 20-year period. It was highest among women and individuals with the lowest education, but the increase was most striking among well-educated men. A comprehensive public health strategy targeting the whole population and especially those with low education is urgently needed to halt the obesity epidemic. PMID- 19874530 TI - Viral obesity: fact or fiction? AB - The aetiology of obesity is multifactorial. An understanding of the contributions of various causal factors is essential for the proper management of obesity. Although it is primarily thought of as a condition brought on by lifestyle choices, recent evidence shows there is a link between obesity and viral infections. Numerous animal models have documented an increased body weight and a number of physiologic changes, including increased insulin sensitivity, increased glucose uptake and decreased leptin secretion that contribute to an increase in body fat in adenovirus-36 infection. Other viral agents associated with increasing obesity in animals included canine distemper virus, rous-associated virus 7, scrapie, Borna disease virus, SMAM-1 and other adenoviruses. This review attempted to determine if viral infection is a possible cause of obesity. Also, this paper discussed mechanisms by which viruses might produce obesity. Based on the evidence presented in this paper, it can be concluded that a link between obesity and viral infections cannot be ruled out. Further epidemiologic studies are needed to establish a causal link between the two, and determine if these results can be used in future management and prevention of obesity. PMID- 19874531 TI - Weight loss interventions in young people (18 to 25 year olds): a systematic review. AB - This systematic review assesses weight loss interventions in young adults (18-25 years), who are vulnerable to weight gain. This age group experience critical life course points (leaving home for higher studies or job, pregnancy, cohabitation) and develop/establish lifestyle and behavioural patterns making this an opportune intervention period. Medline, Embase, Cinahl, PsychINFO and Cochrane Library were searched (1980 to March 2008). All trials and cohort studies with control groups that assessed weight loss interventions in this specific age group were included finally identifying 14 studies. Before and after comparison of behavioural/motivational interventions (-2.40 kg; 95% CI -5.4 to 0.6) and combination interventions (-2.96; 95% CI -4.4 to -1.5) consistently showed weight loss. Behavioural/motivational interventions increased self efficacy, the desire to control weight, boosted self-esteem, and increased satisfaction with body areas and appearance. Interventions also showed improvements in HDL cholesterol, insulin, glucose and maximum oxygen uptake. However, recruitment to participation in interventions was a barrier for this age group with small sample sizes and short-term interventions. There may be gender differences in preference to participation in certain type of interventions. Further research to understand attitudes towards healthy lifestyle and preferences of interventions is needed to develop suitable interventions for this vulnerable age group. PMID- 19874532 TI - Design and statistical analysis of oral medicine studies: common pitfalls. AB - A growing number of articles are emerging in the medical and statistics literature that describe epidemiologic and statistical flaws of research studies. Many examples of these deficiencies are encountered in the oral, craniofacial, and dental literature. However, only a handful of methodologic articles have been published in the oral literature warning investigators of potential errors that may arise early in the study and that can irreparably bias the final results. In this study, we briefly review some of the most common pitfalls that our team of epidemiologists and statisticians has identified during the review of submitted or published manuscripts and research grant applications. We use practical examples from the oral medicine and dental literature to illustrate potential shortcomings in the design and analysis of research studies, and how these deficiencies may affect the results and their interpretation. A good study design is essential, because errors in the analysis can be corrected if the design was sound, but flaws in study design can lead to data that are not salvageable. We recommend consultation with an epidemiologist or a statistician during the planning phase of a research study to optimize study efficiency, minimize potential sources of bias, and document the analytic plan. PMID- 19874533 TI - Proliferation, migration and apoptosis of periodontal ligament cells after tooth replantation. AB - OBJECTIVE: The aim of this study was to investigate the proliferation, migration and death of periodontal ligament (PDL) cells after tooth replantation. MATERIALS AND METHODS: Maxillary first molars were extracted from 4-week-old male (n = 28) Sprague-Dawley rats and immediately replanted, after which, proliferation, migration and death of PDL cells were investigated. RESULTS: At 3 days after tooth replantation, many proliferative cell nuclear antigen (PCNA)-positive PDL cells were observed on the alveolar bone side, but fewer on the root side. However, while a gradual decrease was observed in number of PCNA-positive PDL cells on the alveolar bone side until 7 days, an increase was seen on the root side. At 3 weeks, cells labeled with PKH26 (fluorescent dye into plasma membrane) were located in the middle of the PDL space. However, these PKH26-labeled cells did not spread to the surface of the cementum or the alveolar bone. TUNEL positive cells were observed on both the bone and root sides at 3 days. Number of apoptotic cells increased until 7 days on the bone sides, but decreased on root sides. CONCLUSION: These results suggest that both cell proliferation and apoptosis occur in different patterns and at different times to maintain regular spacing of the PDL after tooth replantation. PMID- 19874534 TI - Evidence-based interventional pain medicine according to clinical diagnoses. 2. Cluster headache. AB - Cluster headache is a strictly unilateral headache that is associated with ipsilateral cranial autonomic symptoms and usually has a circadian and circannual pattern. Prevalence is estimated at 0.5 to 1.0/1,000. The diagnosis of cluster headache is made based on the patient's case history. There are two main clinical patterns of cluster headache: the episodic and the chronic. Episodic is the most common pattern of cluster headache. It occurs in periods lasting 7 days to 1 year and is separated by at least a 1-month pain-free interval. The attacks in the chronic form occur for more than 1 year without remission periods or with remission periods lasting less than 1 month. Conservative therapy consists of abortive and preventative remedies. Ergotamines and sumatriptan injections, sublingual ergotamine tartrate administration, and oxygen inhalation are effective abortive therapies. Verapamil is an effective and the safest prophylactic remedy. When pharmacological and oxygen therapies fail, interventional pain treatment may be considered. The effectiveness of radiofrequency treatment of the ganglion pterygopalatinum and of occipital nerve stimulation is only evaluated in observational studies, resulting in a 2 C+ recommendation. In conclusion, the primary treatment is medication. Radiofrequency treatment of the ganglion pterygopalatinum should be considered in patients who are resistant to conservative pain therapy. In patients with cluster headache refractory to all other treatments, occipital nerve stimulation may be considered, preferably within the context of a clinical study. PMID- 19874535 TI - Evidence-based interventional pain medicine according to clinical diagnoses. 3. Persistent idiopathic facial pain. AB - Persistent idiopathic facial pain, previously known as atypical facial pain, is described as a persistent facial pain that does not have the classical characteristics of cranial neuralgias and for which there is no obvious cause (International Classification of Headache Disorders in 2004). According to these criteria, the diagnosis is possible if the facial pain is localized, present daily, and throughout all or most of the day. By definition, neurological and physical examination findings in persistent idiopathic facial pain should be normal. Forming a diagnosis is not simple and follows a process of elimination of other causes of facial pain. The precise incidence is unknown. The affliction is seen primarily in older adults and rarely in children. The pathophysiology is unknown. In persistent idiopathic facial pain, there is no abnormal processing of somatosensory stimuli in the pain area or facial area of the primary somatosensory cortex of the brain. The treatment is difficult and often requires a multidisciplinary approach. The most important part of the treatment is psychological counseling and pharmacological therapy. Pharmacological treatment with tricyclic antidepressants and anti-epileptic drugs can be tried. The conservative, pharmacological treatment with amitryptiline is the primary choice. Venlafaxine and fluoxetine treatment can also be considered. When the pharmacological treatment fails, pulsed radiofrequency treatment of the ganglion pterygopalatinum (sphenopalatinum) can be considered (2 C+). PMID- 19874536 TI - What is the case for prescribing long-acting opioids over short-acting opioids for patients with chronic pain? A critical review. AB - INTRODUCTION: Effective pain management requires appropriate patient assessment, ongoing reassessment, and an understanding of the options available for the treatment of patients with chronic pain. Opioids have long been an important option in the management of moderate to severe chronic pain, but optimal use requires understanding the variety of choices currently available. METHODS: Literature search was carried out using PubMed. Search terms included "steady state," "pharmacokinetics," "pharmacodynamics," "chronic non-cancer pain," "sustained release opioid," "extended release opioid," "controlled release opioid," "morphine," "oxymorphone," "hydromorphone," "oxycodone," and "fentanyl." RESULTS: This search found 12 chronic pain studies that compared short- and long acting opioids head-to-head. These were supplemented with representative studies from the chronic pain literature. DISCUSSION: The objective of this article is to review clinical data for the use of long-acting and short-acting opioids in a variety of chronic noncancer pain conditions. Although some patients with chronic pain appear to prefer short-acting opioids, many patients receiving long-acting opioid formulations show improved treatment responses and better perception of quality of life. In addition, the sustained reductions in pain seen with long acting opioid formulations may promote patients' focus on daily activities rather than on their pain, thereby improving therapy adherence and reducing pain-related anxieties. CONCLUSION: Long-term clinical trials of these formulations are needed to allow clinicians to make informed decisions about which patient groups might benefit most from these formulations. PMID- 19874538 TI - Sedation during cervical vs. Lumbar translaminar epidural steroid injections. PMID- 19874540 TI - The Dof protein DAG1 mediates PIL5 activity on seed germination by negatively regulating GA biosynthetic gene AtGA3ox1. AB - We have previously shown that inactivation of the gene encoding the Arabidopsis thaliana transcription factor DOF AFFECTING GERMINATION 1 (DAG1) renders seed germination more sensitive to both phytochrome B (phyB) and gibberellins (GA). dag1 mutant seeds require less red (R) light fluence and a lower GA concentration than WT to germinate. Here, we show that inactivation of the gene PHYTOCHROME INTERACTING FACTOR 3-LIKE 5 (PIL5) results in down-regulation of DAG1. Inactivation of PIL5 in the dag1 mutant background further increased the germination potential of dag1 mutant seeds, supporting the suggestion that DAG1 is under the positive control of PIL5. Germination of dag1phyB seeds showed a reduced requirement of gibberellins as compared with phyB mutant seeds, both in the presence and in the absence of GA biosynthesis. Furthermore, the GA biosynthetic gene AtGA3ox1 is upregulated in dag1 seeds as compared with the WT, and DAG1 actually binds to the AtGA3ox1 promoter, as shown by chromatin immunoprecipitation experiments. Expression analysis at different time points confirms that AtGA3ox1 is directly regulated by DAG1, while suggesting that DAG1 is not a direct regulatory target of PIL5. Our data indicate that in the phyB pathway leading to seed germination, DAG1 negatively regulates GA biosynthesis and suggest that DAG1 acts downstream of PIL5. In addition, the analysis of hypocotyls of dag1 and phyB mutant plantlets, of plantlets overexpressing phyB in the dag1 mutant, as well as of dag1phyB double mutant suggests that DAG1 may act as a negative regulatory element downstream of phyB also in hypocotyl elongation. PMID- 19874542 TI - Arabidopsis thaliana plastidial methionine sulfoxide reductases B, MSRBs, account for most leaf peptide MSR activity and are essential for growth under environmental constraints through a role in the preservation of photosystem antennae. AB - Methionine oxidation to methionine sulfoxide (MetSO) is reversed by two types of methionine sulfoxide reductases (MSRs), A and B, specific to MetSO S- and R diastereomers, respectively. Two MSRB isoforms, MSRB1 and MSRB2, are present in chloroplasts of Arabidopsis thaliana. To assess their physiological role, we characterized Arabidopsis mutants knockout for the expression of MSRB1, MSRB2 or both genes. Measurements of MSR activity in leaf extracts revealed that the two plastidial MSRB enzymes account for the major part of leaf peptide MSR capacity. Under standard conditions of light and temperature, plants lacking one or both plastidial MSRBs do not exhibit any phenotype, regarding growth and development. In contrast, we observed that the concomitant absence of both proteins results in a reduced growth for plants cultivated under high light or low temperature. In contrast, double mutant lines restored for MSRB2 expression display no phenotype. Under environmental constraints, the MetSO level in leaf proteins is higher in plants lacking both plastidial MSRBs than in Wt plants. The absence of plastidial MSRBs is associated with an increased chlorophyll a/b ratio, a reduced content of Lhca1 and Lhcb1 proteins and an impaired photosynthetic performance. Finally, we show that MSRBs are able to use as substrates, oxidized cpSRP43 and cpSRP54, the two main components involved in the targeting of Lhc proteins to the thylakoids. We propose that plastidial MSRBs fulfil an essential function in maintaining vegetative growth of plants during environmental constraints, through a role in the preservation of photosynthetic antennae. PMID- 19874541 TI - PYR/PYL/RCAR family members are major in-vivo ABI1 protein phosphatase 2C interacting proteins in Arabidopsis. AB - Abscisic acid (ABA) mediates resistance to abiotic stress and controls developmental processes in plants. The group-A PP2Cs, of which ABI1 is the prototypical member, are protein phosphatases that play critical roles as negative regulators very early in ABA signal transduction. Because redundancy is thought to limit the genetic dissection of early ABA signalling, to identify redundant and early ABA signalling proteins, we pursued a proteomics approach. We generated YFP-tagged ABI1 Arabidopsis expression lines and identified in vivo ABI1-interacting proteins by mass-spectrometric analyses of ABI1 complexes. Known ABA signalling components were isolated including SnRK2 protein kinases. We confirm previous studies in yeast and now show that ABI1 interacts with the ABA signalling kinases OST1, SnRK2.2 and SnRK2.3 in plants. Interestingly, the most robust in planta ABI1-interacting proteins in all LC-MS/MS experiments were nine of the 14 PYR/PYL/RCAR proteins, which were recently reported as ABA-binding signal transduction proteins, providing evidence for in vivo PYR/PYL/RCAR interactions with ABI1 in Arabidopsis. ABI1-PYR1 interaction was stimulated within 5 min of ABA treatment in Arabidopsis. Interestingly, in contrast, PYR1 and SnRK2.3 co-immunoprecipitated equally well in the presence and absence of ABA. To investigate the biological relevance of the PYR/PYLs, we analysed pyr1/pyl1/pyl2/pyl4 quadruple mutant plants and found strong insensitivities in ABA-induced stomatal closure and ABA-inhibition of stomatal opening. These findings demonstrate that ABI1 can interact with several PYR/PYL/RCAR family members in Arabidopsis, that PYR1-ABI1 interaction is rapidly stimulated by ABA in Arabidopsis and indicate new SnRK2 kinase-PYR/PYL/RCAR interactions in an emerging model for PYR/PYL/RCAR-mediated ABA signalling. PMID- 19874543 TI - Transformation of the flax rust fungus, Melampsora lini: selection via silencing of an avirulence gene. AB - Rust fungi cause devastating diseases on many important food crops, with a damaging stem rust epidemic currently affecting wheat production in Africa and the Middle East. These parasitic fungi propagate exclusively on plants, precluding the use of many biotechnological tools available for other culturable fungi. In particular the lack of a stable transformation system has been an impediment to the genetic manipulation required for molecular analysis of rust pathogenicity. We have developed an Agrobacterium-mediated genetic transformation procedure for the model flax rust fungus Melampsora lini, which infects flax (Linum usitatissimum). Selection of transgenic rust lines is based on silencing of AvrL567, which encodes a rust effector protein that is recognised by the flax L6 immune receptor. The non-transgenic rust line is unable to infect flax plants expressing L6, while silenced transgenic lines are virulent on these plants, providing an effective selection system. This directly confirms that the cloned AvrL567 gene is responsible for flax rust virulence phenotypes, and demonstrates the utility of this system to probe rust gene function. PMID- 19874544 TI - Autoimmunity: limited progress for the patient, despite decades of research. PMID- 19874545 TI - Use of immobilized HLA-A2:Ig dimeric proteins to determine the level of epitope specific, HLA-restricted CD8(+) T-cell response. AB - A novel assay to assess antigen-specific cytokine release from stimulated CD8(+) T cells derived from the mucosal and peripheral blood compartments has been developed and standardized using the influenza A virus matrix protein (MP) peptide, GILGFVFTL. This technology is based on the capacity for the human leucocyte antigen (HLA)-A2:Ig dimeric protein to stimulate CD8(+) T cells in a major histocompatibility complex (MHC) class I-restricted fashion without the necessity for antigen presenting cells (APC). This assay has been optimized utilizing a 9-amino acid residue (9mer) peptide, the optimal peptide length for presenting an epitope to CD8(+) T cells. Compared to existing assays, this more sensitive and specific methodology requires fewer cells, enabling easier and more accurate monitoring of the CD8(+) T-cell response in biological compartments, such as the mucosa during the course of viral infection and may be utilized to assess epitope-specific CD8(+) T-cell responses in vaccine trials. PMID- 19874546 TI - Effects of lipopolysaccharide on the induction of mixed chimerism in cyclophosphamide-induced tolerance. AB - Cyclophosphamide (CP)-induced tolerance is a mixed chimerism-based tolerance and is one of the strategies used to induce transplant tolerance. Toll-like receptor (TLR) agonists are reportedly able to abrogate the induction of tolerance by activating alloreactive T cells, or by inhibiting Treg cells. However, little is known about the effect of the immune response mediated by TLR on mixed chimerism based tolerance protocols. In this study, we evaluated the influence of lipopolysaccharide (LPS), which is best known as an TLR4 agonist, on CP-induced tolerance. BALB/c (H-2(d)) mice received a conditioning regimen consisting of 10(8) donor DBA/2 (H-2(d)) spleen cells (SC) on day 0 and 200 mg/kg CP on day 2. A single dose of 20 microg LPS was injected on day -2, 0, 7, or 35. Our results showed that LPS infusion at any time point resulted in chronic rejection of donor skin grafts and the abrogation of mixed chimerism in 33-60% of recipients. We found a correlation between skin graft acceptance and higher levels of mixed chimerism. Flow cytometric analysis revealed that donor-reactive T cells were permanently eliminated, regardless of LPS infusion. In conclusion, LPS-infusion had little influence on the immune response of donor-reactive T cells, but had a significant effect on the induction and maintenance of mixed chimerism in CP induced tolerance. PMID- 19874547 TI - TLR9 activation increases TAP-independent vesicular MHC class I processing in vivo. AB - Cross-presentation of soluble protein antigens on major histocompatibility complex (MHC) class I by dendritic cells (DC) can occur in vesicular, endolysosomal compartments and be either dependent or independent of TAP peptide transporters. Here we investigate if an immunostimulatory CpG oligodeoxynucleotide can increase the activity in a TAP-independent endolysosomal vesicular pathway (el-VP) in vivo as we have earlier found in in vitro cultured DC. We use the in vivo response of CFSE labelled OT-1 T cells, transgenic for a T cell receptor (TCR) that recognizes an ovalbumin (OVA)-derived peptide (SIINFEKL) presented by H-2K(b), transferred into TAP1(-/-) mice, as a functional read-out for activity in the el-VP. We have found a poor OT-1 T-cell response to soluble OVA which, however, could be strongly enhanced by the simultaneous administration of CpG. This increased responsiveness required both the endolysosomal cathepsin S (CatS) and Toll like receptor (TLR)9, the CpG receptor, both of which are present in the el-VP. Confocal microscopy demonstrated a co-localization of H 2K(b)/SIINFEKL and the endolysosomal marker LAMP1 in CD11c positive DC which was markedly increased by CpG administration. No complexes were found in the ER and cis-Golgi compartments in TAP1(-/-) mice, indicating the lack of classical MHC-I processing. In DC isolated from CatS(-/-) mice the opposite was found, complexes were present in the ER but not in the el-VP. We conclude that in vivo activation of TLR9 by CpG increases the efficiency of TAP independent el-VP and that this might contribute to the potent adjuvant activity of this type of compound. The cellular mechanisms remain to be established. PMID- 19874548 TI - Insulin2 gene (Ins2) transcription by NOD bone marrow-derived cells does not influence autoimmune diabetes development in NOD-Ins2 knockout mice. AB - Insulin is a critical autoantigen for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. About 80% of NOD females and 30-40% of NOD males develop diabetes. However, Insulin2 (Ins2) knockout NOD mice develop autoimmune diabetes with complete penetrance in both sexes, at an earlier age, and have stronger autoimmune responses to insulin. The severe diabetes phenotype observed in NOD-Ins2-/- mice suggests that lack of Ins2 expression in the thymus may compromise immunological tolerance to insulin. Insulin is a prototypical tissue specific antigen (TSA) for which tolerance is dependent on expression in thymus and peripheral lymphoid tissues. TSA are naturally expressed by medullary thymic epithelial cells (mTEC), stromal cells in peripheral lymphoid tissues and bone marrow (BM)-derived cells, mainly CD11c(+) dendritic cells. The natural expression of TSA by mTEC and stromal cells has been shown to contribute to self tolerance. However, it is unclear whether this also applies to BM-derived cells naturally expressing TSA. To address this question, we created BM chimeras and investigated whether reintroducing Ins2 expression solely by NOD BM-derived cells delays diabetes development in NOD-Ins2-/- mice. On follow-up, NOD-Ins2-/- mice receiving Ins2-expressing NOD BM cells developed diabetes at similar rates of those receiving NOD-Ins2-/- BM cells. Diabetes developed in 64% of NOD recipients transplanted with NOD BM and in 47% of NOD mice transplanted with NOD-Ins2-/- BM (P = ns). Thus, NOD-Ins2-/- BM did not worsen diabetes in NOD recipients and Ins2 expression by NOD BM-derived cells did not delay diabetes development in NOD-Ins2 /- mice. PMID- 19874549 TI - A comparative study of transfection methods for RNA interference in bone marrow derived murine dendritic cells. AB - Selective gene silencing using RNA interference (RNAi) has been shown to be an efficient method for manipulation of cellular functions. In this study, we compare three previously established methods for transfection of murine bone marrow-derived DC (BM-DC). We tested the efficacy of electroporation with the Mouse Nucleofector kit((R)) from Amaxa Biosystems and lipid-based transfection methods using transfection reagents from Santa Cruz Biotechnology or Genlantis. To analyse the transfection efficacy we used FITC-conjugated siRNA as a positive control together with CD80 and CD86 specific siRNA. We show that electroporation using the Mouse Nucleofector kit((R)) from Amaxa Biosystems was not an efficient method to transfect BM-DC with siRNA in our hands. Transfection with Santa Cruz Biotechnology reagents resulted in up to 59% FITC-siRNA positive cells, but did not result in effective silencing of CD80 surface expression. In contrast, the most effective method was the lipid-based method using the siRNA transfection reagent GeneSilencer((R)) from Genlantis. This protocol resulted in up to 92% FITC-siRNA positive cells after 4 h which declined to 62% and 59% 24 and 48 h post-transfection, respectively. The transfected BM-DC remained CD11c positive, expressed high MHC class II and intermediate CD40 and were functional as APC. In conclusion, this protocol was effective for manipulation of murine BM-DC function through the use of specific siRNA and such methods can be important for the future study of DC-T cell interactions. PMID- 19874550 TI - Identification of Rv2041c, a novel immunogenic antigen from Mycobacterium tuberculosis with serodiagnostic potential. AB - Novel immunogenic antigens are continually required for the improvement of diagnostic techniques for Mycobacterium tuberculosis infection. Some proteins with serodiagnostic value are not expressed under normal culture conditions, but may be induced under specific conditions such as gradual oxygen depletion and low pH, and from inside macrophages. Using a customized amplification library, we previously found that Rv2041c from M. tuberculosis H37Rv was highly expressed in vitro under conditions of low pH and hypoxia. In this study, recombinant (r)Rv2041c was produced in Escherichia coli to examine its role in immune responses. Increased Rv2041c expression in vitro during dormancy and during infection in human macrophages was confirmed by Western blotting and reverse transcription polymerase chain reaction, respectively. Interestingly, positive antibody responses to rRv2041c were detected only in those patients with active tuberculosis (TB) and in mice infected with M. tuberculosis H37Rv. Finally, Rv2041c was used successfully in the serodiagnosis of active M. tuberculosis infection in Korean patients in conjunction with other M. tuberculosis proteins, including Ag85 complex, 38 kDa, rESAT-6, rHSP-X and rCFP-10. Our Rv2041c-ELISA had comparable diagnostic sensitivity and equivalent specificity to the use of an M. tuberculosis H37Rv cellular extract. In addition, seven of 46 serum samples collected from TB patients (15.28%) showed positive antibody responses to Rv2041c, but not to the other proteins. These results suggest that Rv2041c can be used to increase assay sensitivity alongside well-known antigens for the serodiagnosis of M. tuberculosis infection. PMID- 19874551 TI - New alternative vaccine component against mycobacterium tuberculosis--heat shock protein 16.3 or its T-cell epitope. AB - Heat shock protein 16.3 (Hsp16.3) of Mycobacterium tuberculosis (MTB) containing T-cell and B-cell epitopes not only plays an important role in the survival of MTB against macrophages, but also has great potential to be used to develop new TB vaccines. In order to study whether Hsp16.3 can be replaced with its T-cell epitope for producing a vaccine against TB, we expressed and purified Hsp16.3 protein of MTB H37Rv strain and confirmed by immunoblotting. The immune responses and protection against the H37Rv induced by Hsp16.3 protein were compared with its T-cell epitope synthetic peptide in mice. The results showed that both Hsp16.3 and its synthetic peptide induced significantly stronger specific antibodies than the classical TB vaccine-BCG (bacillus Calmette-Guerin). Compared with BCG, the stimulation index in the splenolymphocyte proliferation of both recombinant protein and its synthetic peptide were remarkably enhanced, but the levels of IFN-gamma release were lower. Dramatic reduction in the numbers of MTB colony forming units (CFU) in the spleens and lungs was observed in the mice immunized with Hsp16.3 or its synthetic peptide. The protection provided by Hsp16.3 or its synthetic peptide in the lungs was equivalent to that provided by BCG. Both Hsp16.3 and its T-cell epitope are effective components and Hsp16.3 can be replaced with its T-cell epitope while developing the vaccine against TB, without requiring the complicated procedure of expressing and purifying Hsp16.3. PMID- 19874552 TI - Common CCR 5 polymorphism in stroke: the CCR 5 delta32 polymorphism differentiates cardioembolism from other aetiologies of ischaemic cerebrovascular diseases. AB - Inflammation is involved in the development of atherosclerosis. The CC chemokine receptor 5 (CCR5) initiates chemotaxis and modulates the inflammation secondary to atherosclerosis and related vascular diseases. The CCR5 Delta32 polymorphism influences the expression of CCR5 on the cell surface. The purpose of this study was to examine the effect of the Delta32 polymorphism in ischaemic cerebrovascular disease (ICVD). The CCR5 Delta32 polymorphism was genotyped in 1462 individuals: 562 ischaemic stroke (IS), 97 transient ischaemic attack (TIA) and in 803 healthy controls. All 659 ICVD patients were categorized according to the Trial of Org 10172 in Acute Stroke Treatment aetiological classification. The investigated subtypes were large artery atherosclerosis (LAA), cardioembolism (CE), small artery occlusion (SAO) and cryptogenic disease (CRYPT). Genotyping was performed with the TaqMan polymerase chain reaction. The Delta32 allele was less frequent in CE patients compared with LAA (OR, 0.4; 95% CI, 0.24-0.79; P = 0.008), SAO (OR, 0.5; 95% CI, 0.29-0.84; P = 0.01), CRYPT (OR, 0.5; 95% CI, 0.28 0.82; P = 0.008) and controls (OR, 0.5; 95% CI, 0.36-0.82; P = 0.002). Multiple logistic regression analysis showed that the Delta32 allele is associated with a lower risk for cardioembolic ICVD (OR 0.5; 95% CI, 0.28-0.75; P = 0.002) when compared with ICVD of other causes. The Delta32 polymorphism of CCR5 may differentiate cardioembolism from the remaining causes of ICVD. PMID- 19874553 TI - Immune responses in patients with metastatic renal cell carcinoma treated with dendritic cells pulsed with tumor lysate. AB - Patients with metastatic renal cell carcinoma (mRCC) have a limited life expectancy but still a subset of these patients develop immune and clinical responses after immunotherapy including dendritic cell (DC) vaccination. In a recently published phase I/II trials, fourteen HLA-A2 negative patients with progressive mRCC were vaccinated with autologous DC pulsed with allogeneic tumour lysate. Low-dose IL-2 administered subcutaneously was given concomitantly. In this study, we analysed lysate specific proliferation of PBMCs from these patients together with the TH1/TH2 balance of the responding T cells. Also, serum concentrations of IL-10, IL-12, IL-15, IL-17 and IL-18 from these patients and additional thirteen HLA-A2 positive mRCC patients treated with autologous DC pulsed with survivin and telomerase peptides were analysed during vaccination to identify systemic immune responses and potential response biomarkers. In HLA-A2 negative mRCC patients a spontaneous predominance of TH1 secreting tumour lysate specific T cells was observed prior to vaccination in patients attaining stable disease (SD) during treatment whereas patients with continued progressive disease (PD) had a mixed TH1/TH2 response. The TH1/TH2 balance was unchanged during vaccination also when tumour lysate specific T cell responses increased. An increase in IL-12, IL-17 and IL-18 serum concentrations was observed during vaccination but no difference between patients with SD and PD was observed. IL-10 or IL-15 was not measurable in serum. PMID- 19874555 TI - Retraction. PMID- 19874554 TI - Serum soluble interleukin-2 receptor, beta2-microglobulin, lactate dehydrogenase and erythrocyte sedimentation rate in children with Hodgkin's lymphoma. AB - The study was to determine clinical utility of serum soluble interleukin (IL)-2 receptor (sIL-2Ralpha), beta(2)-microglobulin (beta(2)-M), lactate dehydrogenase (LDH) and erythrocyte sedimentation rate (ESR) as markers of diagnosis, prognosis and monitoring of response to therapy in childhood Hodgkin's lymphoma (HL). The markers were measured prospectively before treatment and in complete remission (CR) during and after therapy in 30 children with HL (F/M:19/11; median age: 11.3 years) and once in 50 healthy children (F/M: 24/26; median age: 8.7 years). Median pretreatment levels of all analysed markers were significantly higher than in healthy controls. Increased pretreatment sIL-2Ralpha, LDH and ESR correlated with bulky disease; sIL-2Ralpha, beta(2)-M and ESR with presence of B symptoms and sIL-2Ralpha and LDH with advanced HL stages. There was a correlation between sIL-2Ralpha and LDH and between beta(2)-M and ESR. The levels and rates of elevated markers reflected well the response to chemotherapy, decreasing significantly when patients achieved CR and further on with therapy continuation. Since all patients survived thus the markers' value to predict the outcome was not established. Serum sIL-2Ralpha, beta(2)-M, LDH and ESR may act as markers for diagnostics and used in monitoring of therapy effectiveness in childhood HL. The markers were also increased in subgroups of patients with unfavourable clinical features; however, small sample size of the study did not allow to draw conclusion on their prognostic roles. We were also not able to establish the influence of markers on event free survival and overall survival because all children survived independent of initial clinical characteristics and pretreatment levels of sIL-2Ralpha, beta(2)-M, LDH and ESR. PMID- 19874556 TI - No association of KIR3DL1 or KIR3DS1 or their alleles with ankylosing spondylitis. AB - We determined the alleles of KIR3DL1 and KIR3DS1 in a cohort of British Caucasian ankylosing spondylitis (AS) patients and HLA-B27-positive controls. We found no association in frequencies of the alleles of these genes in AS. In addition, no differences were found when the patients and controls were differentiated by gender. PMID- 19874557 TI - Hydrophobic and basic domains target proteins to lipid droplets. AB - In recent years, progress in the study of the lateral organization of the plasma membrane has led to the proposal that mammalian cells use two different organelles to store lipids: intracellular lipid droplets (LDs) and plasma membrane caveolae. Experimental evidence suggests that caveolin (CAV) may act as a sensitive lipid-organizing molecule that physically connects these two lipid storing organelles. Here, we determine the sequences necessary for efficient sorting of CAV to LDs. We show that targeting is a process cooperatively mediated by two motifs. CAV's central hydrophobic domain (Hyd) anchors CAV to the endoplasmic reticulum (ER). Next, positively charged sequences (Pos-Seqs) mediate sorting of CAVs into LDs. Our findings were confirmed by identifying an equivalent, non-conserved but functionally interchangeable Pos-Seq in ALDI, a bona fide LD-resident protein. Using this information, we were able to retarget a cytosolic protein and convert it to an LD-resident protein. Further studies suggest three requirements for targeting via this mechanism: the positive charge of the Pos-Seq, physical proximity between Pos-Seq and Hyd and a precise spatial orientation between both motifs. The study uncovers remarkable similarities with the signals that target proteins to the membrane of mitochondria and peroxisomes. PMID- 19874558 TI - Analysis of articulation between clathrin and retromer in retrograde sorting on early endosomes. AB - Clathrin and retromer have key functions for retrograde trafficking between early endosomes and the trans-Golgi network (TGN). Previous studies on Shiga toxin suggested that these two coat complexes operate in a sequential manner. Here, we show that the curvature recognition subunit component sorting nexin 1 (SNX1) of retromer interacts with receptor-mediated endocytosis-8 (RME-8) protein, and that RME-8 and SNX1 colocalize on early endosomes together with a model cargo of the retrograde route, the receptor-binding B-subunit of Shiga toxin (STxB). RME-8 has previously been found to bind to the clathrin uncoating adenosine triphosphatase (ATPase) Hsc70, and we now report that depletion of RME-8 or Hsc70 affects retrograde trafficking at the early endosomes-TGN interface of STxB and the cation-independent mannose 6-phosphate receptor, an endogenous retrograde cargo protein. We also provide evidence that retromer interacts with the clathrin binding protein hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) not only via SNX1, as previously published (Chin Raynor MC, Wei X, Chen HQ, Li L. Hrs interacts with sorting nexin 1 and regulates degradation of epidermal growth factor receptor. J Biol Chem 2001;276:7069-7078), but also via the core complex component Vps35. Hrs codistributes at the ultrastructural level with STxB on early endosomes, and interfering with Hrs function using antibodies or mild overexpression inhibits retrograde transport. Our combined data suggest a model according to which the functions in retrograde sorting on early endosomes of SNX1/retromer and clathrin are articulated by RME-8, and possibly also by Hrs. PMID- 19874559 TI - Severe neonatal alloimmune thrombocytopaenia with anaemia. PMID- 19874560 TI - Hemolytic disease of the fetus/newborn: reflections on articles from TRANSFUSION Volume 1. PMID- 19874561 TI - Periods without agitation diminish platelet mitochondrial function during storage. AB - BACKGROUND: Prolonged periods without agitation produce platelet (PLT) storage lesions that result in reduced in vitro assay parameters and an increase of apoptotic markers during storage. The aim of this study was to evaluate the influence of periods without agitation on PLT mitochondrial function, blood gases, and activation. STUDY DESIGN AND METHODS: Apheresis PLT units (n = 12) were collected using a cell separator and each was equally divided among five storage bags (50 mL of PLT suspension in 300-mL nominal volume containers). Four bags were held without agitation for 24, 48, 72, and 96 hours in a standard shipping box at room temperature and the fifth bag was continuously agitated. PLTs were assayed for standard in vitro PLT assays as well as for mitochondrial membrane potential (MMP), accumulation of reactive oxygen species, Annexin V binding, mitochondrial mass, and activity of mitochondrial reduction power (MRP) immediately after removal of units from the shipping container on Days 1, 2, 3, 4, and 7. RESULTS: Increasing periods without agitation resulted in increased superoxide anion generation and PLT activation as well as reduced PLT MMP and MRP. Increasing periods without agitation resulted in increasing Annexin V binding. PLTs that had undergone periods without agitation showed increased oxygen and carbon dioxide levels immediately after storage without agitation. The superoxide anion generation was highly correlated with the loss of MMP, increasing Annexin V binding, and pH decline. CONCLUSIONS: PLTs, if stored without agitation, produce a lesion that leads PLTs to apoptosis. The severity of the lesion depends on the length of the period without agitation. Prolonged periods without agitation induce formation of superoxides and depolarization of MMP along with a presentation of apoptotic markers. PMID- 19874562 TI - Red blood cell aging markers during storage in citrate-phosphate-dextrose-saline adenine-glucose-mannitol. AB - BACKGROUND: It has been suggested that red blood cell (RBC) senescence is accelerated under blood bank conditions, although neither protein profile of RBC aging nor the impact of additive solutions on it have been studied in detail. STUDY DESIGN AND METHODS: RBCs and vesicles derived from RBCs in both citrate phosphate-dextrose (CPD)-saline-adenine-glucose-mannitol (SAGM) and citrate phosphate-dextrose-adenine (CPDA) were evaluated for the expression of cell senescence markers (vesiculation, protein aggregation, degradation, activation, oxidation, and topology) through immunoblotting technique and immunofluorescence or immunoelectron microscopy study. RESULTS: A group of cellular stress proteins exhibited storage time- and storage medium-related changes in their membrane association and exocytosis. The extent, the rate, and the expression of protein oxidation, Fas oligomerization, caspase activation, and protein modifications in Band 3, hemoglobin, and immunoglobulin G were less conspicuous and/or exhibited significant time retardation under storage in CPD-SAGM, compared to the CPDA storage. There was evidence for the localization of activated caspases near to the membrane of both cells and vesicles. CONCLUSIONS: We provide circumstantial evidence for a lower protein oxidative damage in CPD-SAGM-stored RBCs compared to the CPDA-stored cells. The different expression patterns of the senescence markers in the RBCs seem to be accordingly related to the oxidative stress management of the cells. We suggest that the storage of RBCs in CPD-SAGM might be more alike the in vivo RBC aging process, compared to storage in CPDA, since it is characterized by a slower stimulation of the recognition signaling pathways that are already known to trigger the erythrophagocytosis of senescent RBCs. PMID- 19874563 TI - Recipient-derived HPA-1a antibodies: a cause of prolonged thrombocytopenia after unrelated donor stem cell transplantation. AB - BACKGROUND: Patients with human platelet antigen (HPA) specific antibodies in cases of neonatal alloimmune thrombocytopenia and platelet (PLT) refractoriness derive clinical benefit from the use of HPA-selected PLTs. STUDY DESIGN AND METHODS: This study describes three patients with underlying diagnoses of acute myeloid leukemia, chronic lymphocytic leukemia, and myelodysplasia, respectively, who underwent allogeneic bone marrow transplantation (BMT) with unrelated donors matched at the HLA-A, B, C, Dr, and DQ loci but who failed to achieve an adequate PLT count. Investigation using PLT immunofluorescence test, monoclonal antibody immobilization of PLT antigens assay, and genotyping revealed the presence of recipient-derived HPA-1a antibodies. RESULTS: In two patients, anti-HPA-1a was detected post-BMT and in the third patient, anti-HPA-1a was detected during pre BMT chemotherapy. Despite apparent 100% engraftment of donor cells, the patients' PLT counts failed to recover 9-10 months posttransplant. The patients remained PLT-transfusion dependent and failed to achieve satisfactory increments following random donor or HLA-matched PLT transfusions. After the identification of HPA-1a antibodies, the patients were supported by HPA-1a(-) PLTs and satisfactory posttransfusion PLT increments were obtained. These cases illustrate that HPA-1a antibodies may remain detectable for 10 months following apparently successful donor engraftment and the disappearance of recipient-derived HLA antibodies. The prolonged persistence of recipient-derived PLT-specific antibodies following BMT has to our knowledge not been described previously. CONCLUSION: HPA-1a antibodies were associated with protracted PLT-transfusion dependence and significant hemorrhagic complications. Appropriate and timely laboratory investigation for HPA-specific antibodies followed by transfusion support with HPA-selected PLTs provided the cornerstone of the hemostatic management in these cases. PMID- 19874564 TI - Immune hemolytic anemia due to cimetidine: the first example of a cimetidine antibody. AB - BACKGROUND: Although there have been a few reports of immune hemolytic anemia (IHA) thought to be due to cimetidine, none of them provided proof (e.g., serologic detection of anti-cimetidine and/or repeat of IHA upon drug rechallenge). One report used cimetidine as an example of how temporal associations of drug administration and hemolytic anemia are not proof of a cause effect relationship. STUDY DESIGN AND METHODS: A 63-year-old cancer patient developed IHA on two occasions after receiving cimetidine (with and without chemotherapy). Serologic methods included testing cimetidine-treated red blood cells (RBCs) as well as testing untreated RBCs in the presence of cimetidine. RESULTS: The patient's direct antiglobulin test was positive (C3 only) and a serum antibody to cimetidine was detected by both testing methods. An eluate from the patient's RBCs was nonreactive. Cimetidine-treated RBCs were optimally prepared at room temperature and needed to be tested on the day of preparation. CONCLUSIONS: This is the first reported case of IHA due to a cimetidine antibody where a drug-dependent antibody was demonstrated. The patient had IHA after receiving cimetidine on two separate occasions. PMID- 19874565 TI - Seroprevalence of West Nile virus infection in solid organ transplant recipients. AB - BACKGROUND: Of people infected with mosquito-borne West Nile virus (WNV), <1% develop neuroinvasive disease (NID). Population studies suggest that people older than 65 years may be at higher risk for neurologic symptoms. It has been suggested that solid organ transplant (SOT) recipients are also at higher risk for WNV NID, but definitive serologic and epidemiologic data are lacking. METHODS: A serologic screening survey, using a US Food & Drug Administration approved enzyme-linked immunosorbant assay to detect WNV immunoglobulin-G (IgG) antibody responses in cohorts of SOT recipients and non-immunocompromised controls, was undertaken at a large Midwestern university organ transplant center in the aftermath of the summer 2003 WNV regional outbreak. Hemagglutination inhibition testing was used to confirm WNV IgG-positive results and differentiate them from positive results caused by Saint Louis encephalitis virus, another flavivirus that is endemic in the Midwestern US. FINDINGS: The rate of WNV IgG seropositive responses did not differ between SOT recipients and non immunocompromised controls, and were 12% and 10%, respectively. Retrospective chart review showed no documented WNV NID in the seropositive SOT recipients, suggesting an incidence of WNV NID may be as low as 0.7% in this population. INTERPRETATION: Asymptomatic WNV infection is common among immunocompromised SOT patients, occurring as often as it does in non-immunocompromised controls. Our data indicated that severe WNV NID is less frequent in SOT patients, contrary to what has been suggested in other studies. PMID- 19874566 TI - Pseudomembranous Aspergillus tracheobronchitis in a heart transplant recipient. AB - Aspergillus tracheobronchitis (AT) is an uncommon clinical presentation of pulmonary aspergillosis that frequently progresses to invasive pulmonary aspergillosis. Diagnosis of AT may be delayed because of its insidious onset, non specific signs and symptoms, and scarcity of radiographic abnormalities. We report the case of a patient who received a heart transplant (HT) because of cardiac amyloidosis and who developed pseudomembranous AT. Possible risk factors concurrent in this case were splenectomy, lymphocytopenia, and previous cytomegalovirus infection. Chest computed tomography scan showed thickening of the left bronchi and a 'tree-in-bud' pattern with multiple small nodules. Bronchoscopic examination revealed raised yellowish pseudomembranous plaques on the tracheobronchial tree. Bronchoalveolar lavage and aspirate cultures yielded Aspergillus fumigatus. The patient recovered with voriconazole. Clinicians should be aware of AT as a potential cause of respiratory symptoms with few radiographic abnormalities in HT recipients, as delay in performing bronchoscopy could result in an unfavorable prognosis. PMID- 19874567 TI - Bordetella bronchiseptica pneumonia in a kidney-pancreas transplant patient after exposure to recently vaccinated dogs. AB - Bordetella bronchiseptica is an uncommon cause of respiratory infection in humans generally occurring in immunocompromised individuals exposed to infected animals. A 61-year-old female underwent a kidney-pancreas transplant 7 years before presentation. Postoperative immunosuppression was achieved with sirolimus and mycophenolate mofetil. The patient was doing well until she developed a small bowel obstruction secondary to adhesions. She underwent surgical adhesiolysis without complications. Two weeks postoperatively the patient developed pneumonia. She failed to respond to repeated courses of antibiotics, and thus, diagnostic bronchoscopy with bronchoalveolar lavage (BAL) was performed. BAL cultures grew B. bronchiseptica. Further investigation revealed that the patient's dogs had recently received a live-attenuated B. bronchiseptica intranasal vaccination. The patient recovered after 21 days of therapy with doxycycline based upon in vitro susceptibility testing. B. bronchiseptica is an uncommon but recognized human pathogen. It most commonly affects immunocompromised individuals. Here, we report a culture-proven case of B. bronchiseptica pneumonia in an immunocompromised host residing in a household with her dogs who had recently received live-attenuated, intranasal B. bronchiseptica vaccinations. As polymerase chain reaction testing was not performed comparing the isolated strain to the vaccination strain, the association is presumptive. This report expands the spectrum of immunocompromised hosts to include renal-pancreas transplant patients who have developed infection from B. bronchiseptica, while illustrating the risks associated with animal contacts and attenuated vaccines in the immunosuppressed population. PMID- 19874568 TI - Polymyxin B, scavenger of endotoxin, enhances isolation yield and in vivo function of islets. AB - Collagenase purified from bacteria has been used to isolate islets for transplantation. However, collagenase is contaminated with small amounts of endotoxin, which induces dysfunction or apoptosis of islets. In this study, we investigated the effects of polymyxin B, endotoxin scavenger, on the yield and quality of isolated islets. It is revealed that polymyxin B neutralized endotoxin in vitro and inhibited endotoxin-mediated decreases of the glucose stimulation index. Additionally, adenosine triphosphate (ATP) quantitation, islet regression assay, and caspase-3 activation assay demonstrated that polymyxin B efficiently blocked the toxic effects induced by endotoxin. Thereafter, we isolated mouse islets both with and without polymyxin B and compared total islet equivalents (IEQs), glucose-stimulated insulin release, and ATP content. Polymyxin B enhanced islet recovery, and ATP content of islets, and glucose stimulation index, and reduced TNF-alpha expression of islets. Marginal transplantation (200 IEQs/mouse) under the kidney capsule of diabetic mice induced normoglycemia in 30% of the polymyxin B group, but not in any mouse of control group. This result suggests that islets isolated with polymyxin B more effectively lower blood glucose levels as compared with control islets. Thus, polymyxin B could serve as a useful agent in the protection of islets from endotoxin-induced inflammation and apoptosis. PMID- 19874569 TI - Surgeon Yurii Voronoy (1895-1961) - a pioneer in the history of clinical transplantation: in memoriam at the 75th anniversary of the first human kidney transplantation. PMID- 19874570 TI - In vitro sensitivity of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis Brazilian isolates to meglumine antimoniate and amphotericin B. AB - Resistance of Leishmania parasites to specific chemotherapy has become a well documented problem in the Indian subcontinent in recent years but only a few studies have focused on the susceptibility of American Leishmania isolates. Our susceptibility assays to meglumine antimoniate were performed against intracellular amastigotes after standardizing an in vitro model of macrophage infection appropriate for Leishmania (Viannia) braziliensis isolates. For the determination of promastigote susceptibility to amphotericin B, we developed a simplified MTT-test. The sensitivity in vitro to meglumine antimoniate and amphotericin B of 13 isolates obtained from Brazilian patients was determined. L. (V.) braziliensis isolates were more susceptible to meglumine antimoniate than Leishmania (Leishmania) amazonensis. EC(50), EC(90) and activity indexes (calculated over the sensitivity of reference strains), suggested that all isolates tested were susceptible in vitro to meglumine antimoniate, and did not show association with the clinical outcomes. Isolates were also uniformly susceptible in vitro to amphotericin B. PMID- 19874571 TI - Good research practices for measuring drug costs in cost effectiveness analyses: issues and recommendations: the ISPOR Drug Cost Task Force report--Part I. AB - OBJECTIVES: The assignment of prices or costs to pharmaceuticals can be crucial to results and conclusions that are derived from pharmacoeconomic cost effectiveness analyses (CEAs). Although numerous pharmacoeconomic practice guidelines are available in the literature and have been promulgated in many countries, these guidelines are either vague or silent about how drug costs should be established or measured. This is particularly problematic in pharmacoeconomic studies performed from the "societal" perspective, because typically the measured cost of a brand name pharmaceutical is not a true economic cost but also includes transfer payments from some members of society (patients and third party payers) to other members of society (pharmaceutical manufacturer stockholders) in large part as a reward for biomedical innovation. Moreover, there are numerous and complex institutional factors that influence how drug costs should be measured from other CEA perspectives, both internationally and within the domestic US context. The objective of this report is to provide guidance and recommendations on how drug costs should be measured for CEAs performed from a number of key analytic perspectives. METHODS: ISPOR Task Force on Good Research Practices-Use of Drug Costs for Cost Effectiveness Analysis (Drug Cost Task Force [DCTF]) was appointed with the advice and consent of the ISPOR Board of Directors. Members were experienced developers or users of CEA models, worked in academia, industry, and as advisors to governments, and came from several countries. Because how drug costs should be measured for CEAs depend on the perspectives, five Task Force subgroups were created to develop drug cost standards from the societal, managed care, US government, industry, and international perspective. The ISPOR Task Force on Good Research Practices-Use of Drug Costs for Cost Effectiveness Analysis (DCTF) subgroups met to develop core assumptions and an outline before preparing six draft reports. They solicited comments on the outline and drafts from a core group of 174 external reviewers and more broadly from the membership of ISPOR at two ISPOR meetings and via the ISPOR web site. RESULTS: Drug cost measurements should be fully transparent and reflect the net payment most relevant to the user's perspective. The Task Force recommends that for CEAs of brand name drugs performed from a societal perspective, either 1) CEA analysts use a cost that more accurately reflects true societal drug costs (e.g., 20-60% of average sales price), or when that is too unrealistic to be meaningful for decision-makers, 2) refer to their analyses as from a "limited societal perspective." CEAs performed from a payer perspective should use drug prices actually paid by the relevant payer net of all rebates, copays, or other adjustments. When such price adjustments are confidential, the analyst should apply a typical or average discount that preserves this confidentiality. CONCLUSIONS: Drug transaction prices not only ration current use of medication but also ration future biomedical research and development. CEA researchers should tailor the appropriate measure of drug costs to the analytic perspective, maintain clarity and transparency on drug cost measurement, and report the sensitivity of CEA results to reasonable drug cost measurement alternatives. PMID- 19874572 TI - Effect of iron supplementation on iron status during the first week after blood donation. AB - INTRODUCTION: Frequent blood donations may lead to a negative iron balance. Iron depletion may be prevented by iron supplementation after whole blood donations. The aim of this study was to compare the short time changes in iron status after donation in two groups randomized to iron supplementation or no additional iron. A second objective was to evaluate the effect of iron supplementation in donors having HFE-variants compared to HFE wild types. METHODS: Subjects of both genders (199 women, 200 men) were randomised to receive iron supplementation or no additional iron after donation. Iron status, defined by the concentration of haemoglobin, serum ferritin, soluble transferrin receptor, concentration of haemoglobin in reticulocytes (CHr) and percent hypochrome mature red blood cells, was determined at the start of donation and 8 +/- 2 days after donation. HFE genotyping was performed at reappearance. RESULTS: There was a significant difference between the two study groups on all the iron status parameters. CHr was an efficient, early marker of ongoing synthesis of haemoglobin. Heterozygosity for the HFE variants C282Y and H63D had no statistically significant influence on the iron status. The donor's baseline serum ferritin value may be basis for an individual iron supplementation regimen, as donors with serum ferritin >50 microg/l do not seem to utilize the iron supplementation, but prefer endogenous iron to restore the loss of haemoglobin. CONCLUSION: Iron supplementation had a significant positive impact on the restoration of iron status one week after donation. PMID- 19874573 TI - Retrospective comparison of maternal vs. HPA-matched donor platelets for treatment of fetal alloimmune thrombocytopenia. AB - BACKGROUND AND OBJECTIVES: In fetal alloimmune thrombocytopenia (FAIT), transplacental maternal antibodies cause destruction of fetal platelets. FAIT is similar to fetal Rhesus haemolytic disease, but half of the affected fetuses are born to primiparous women. In 10-20% of cases, prenatal and perinatal intracranial haemorrhages are reported. Different therapeutic approaches have been described, including maternally administered high-dose intravenous immunoglobulin (high dose IVIG) without or with steroids or intrauterine transfusion (IUT) of compatible platelets. For the latter, the use of plasma-free maternal and donor platelets has been described, but a comparison of these two sources of platelets has not been reported. MATERIALS AND METHODS: We retrospectively analyzed the clinical courses of cases with FAIT treated with IUT of either HPA-matched donor platelets or maternal platelets, done by a single team between 1990 and 1997. In 57 pregnancies, FAIT was treated by repeated IUT with either maternal (15 fetuses) or donor platelets (42 fetuses). RESULTS: There was no procedure-related fetal or neonatal loss. Platelets from both sources reliably raised the fetal platelet counts. Donor platelet preparations contained more platelets and yielded higher fetal post-transfusion platelet counts, but maternal platelets were clinically equally effective. CONCLUSIONS: Donor and maternal platelet concentrates are effective sources for the treatment of FAIT. PMID- 19874574 TI - Genetical genomic determinants of alcohol consumption in rats and humans. AB - BACKGROUND: We have used a genetical genomic approach, in conjunction with phenotypic analysis of alcohol consumption, to identify candidate genes that predispose to varying levels of alcohol intake by HXB/BXH recombinant inbred rat strains. In addition, in two populations of humans, we assessed genetic polymorphisms associated with alcohol consumption using a custom genotyping array for 1,350 single nucleotide polymorphisms (SNPs). Our goal was to ascertain whether our approach, which relies on statistical and informatics techniques, and non-human animal models of alcohol drinking behavior, could inform interpretation of genetic association studies with human populations. RESULTS: In the HXB/BXH recombinant inbred (RI) rats, correlation analysis of brain gene expression levels with alcohol consumption in a two-bottle choice paradigm, and filtering based on behavioral and gene expression quantitative trait locus (QTL) analyses, generated a list of candidate genes. A literature-based, functional analysis of the interactions of the products of these candidate genes defined pathways linked to presynaptic GABA release, activation of dopamine neurons, and postsynaptic GABA receptor trafficking, in brain regions including the hypothalamus, ventral tegmentum and amygdala. The analysis also implicated energy metabolism and caloric intake control as potential influences on alcohol consumption by the recombinant inbred rats. In the human populations, polymorphisms in genes associated with GABA synthesis and GABA receptors, as well as genes related to dopaminergic transmission, were associated with alcohol consumption. CONCLUSION: Our results emphasize the importance of the signaling pathways identified using the non-human animal models, rather than single gene products, in identifying factors responsible for complex traits such as alcohol consumption. The results suggest cross-species similarities in pathways that influence predisposition to consume alcohol by rats and humans. The importance of a well-defined phenotype is also illustrated. Our results also suggest that different genetic factors predispose alcohol dependence versus the phenotype of alcohol consumption. PMID- 19874575 TI - Mechanisms of ubiquitin transfer by the anaphase-promoting complex. AB - The anaphase-promoting complex (APC) is a ubiquitin-protein ligase required for the completion of mitosis in all eukaryotes. Recent mechanistic studies reveal how this remarkable enzyme combines specificity in substrate binding with flexibility in ubiquitin transfer, thereby allowing the modification of multiple lysines on the substrate as well as specific lysines on ubiquitin itself. PMID- 19874576 TI - The malaria candidate vaccine liver stage antigen-3 is highly conserved in Plasmodium falciparum isolates from diverse geographical areas. AB - BACKGROUND: A high level of genetic stability has been formerly identified in segments of the gene coding for the liver stage antigen-3 (LSA-3), a subunit vaccine candidate against Plasmodium falciparum. The exploration of lsa-3 polymorphisms was extended to the whole sequence of this large antigen in 20 clinical isolates from four geographical areas; Senegal, Comoro islands, Brazil and Thailand. METHODS: The whole 4680 bp genomic sequence of lsa-3 was amplified by polymerase chain reaction and sequenced. The clinical isolate sequences were aligned on the sequence of the laboratory reference P. falciparum strain 3D7. RESULTS: The non-repeated sequence of lsa-3 was very well conserved with only a few allelic variations scattered along the sequence. Interestingly, a formerly identified immunodominant region, employed for the majority of pre-clinical vaccine development, was totally conserved at the genetic level. The most significant variations observed were in the number and organization of tetrapeptide repeated units, but not in their composition, resulting in different lengths of these repeated regions. The shorter repeated regions were from Brazilian origin. A correlation between the geographical distribution of the parasites with single nucleotide polymorphisms was not detected. CONCLUSION: The lack of correlation between allelic polymorphisms with a specific transmission pressure suggests that LSA-3 is a structurally constrained molecule. The unusual characteristics of the lsa-3 gene make the molecule an interesting candidate for a subunit vaccine against malaria. PMID- 19874577 TI - Changes in serum creatinine in the first 24 hours after cardiac arrest indicate prognosis: an observational cohort study. AB - INTRODUCTION: As patients after cardiac arrest suffer from the consequences of global ischemia reperfusion, we aimed to establish the incidence of acute kidney injury (AKI) in these patients, and to investigate its possible association to severe hypoxic brain damage. METHODS: One hundred and seventy-one patients (135 male, mean age 61.6 +/- 15.0 years) after cardiac arrest were included in an observational cohort study. Serum creatinine was determined at admission and 24, 48 and 72 hours thereafter. Serum levels of neuron-specific enolase (NSE) were measured 72 hours after admission as a marker of hypoxic brain damage. Clinical outcome was assessed at intensive care unit (ICU) discharge using the Pittsburgh cerebral performance category (CPC). RESULTS: AKI as defined by AKI Network criteria occurred in 49% of the study patients. Patients with an unfavourable prognosis (CPC 3-5) were affected significantly more frequently (P = 0.013). Whilst serum creatinine levels decreased in patients with good neurological outcome (CPC 1 or 2) over the ensuing 48 hours, it increased in patients with unfavourable outcome (CPC 3-5). ROC analysis identified DeltaCrea24 <-0.19 mg/dl as the value for prediction with the highest accuracy. The odds ratio for an unfavourable outcome was 3.81 (95% CI 1.98-7.33, P = 0.0001) in cases of unchanged or increased creatinine levels after 24 hours compared to those whose creatinine levels decreased during the first 24 hours. NSE levels were found to correlate with the change in serum creatinine in the first 24 hours both in simple and multivariate regression (both r = 0.24, P = 0.002). CONCLUSIONS: In this large cohort of patient after cardiac arrest, we found that AKI occurs in nearly 50% of patients when the new criteria are applied. Patients with unfavourable neurological outcome are affected more frequently. A significant association between the development of AKI and NSE levels indicating hypoxic brain damage was observed. Our data show that changes in serum creatinine may contribute to the prediction of outcome in patients with cardiac arrest. Whereas a decline in serum creatinine (> 0.2 mg/dL) in the first 24 hours after cardiac arrest indicates good prognosis, the risk of unfavourable outcome is markedly elevated in patients with constant or increasing serum creatinine. PMID- 19874578 TI - PD 0332991, a selective cyclin D kinase 4/6 inhibitor, preferentially inhibits proliferation of luminal estrogen receptor-positive human breast cancer cell lines in vitro. AB - INTRODUCTION: Alterations in cell cycle regulators have been implicated in human malignancies including breast cancer. PD 0332991 is an orally active, highly selective inhibitor of the cyclin D kinases (CDK)4 and CDK6 with ability to block retinoblastoma (Rb) phosphorylation in the low nanomolar range. To identify predictors of response, we determined the in vitro sensitivity to PD 0332991 across a panel of molecularly characterized human breast cancer cell lines. METHODS: Forty-seven human breast cancer and immortalized cell lines representing the known molecular subgroups of breast cancer were treated with PD 0332991 to determine IC50 values. These data were analyzed against baseline gene expression data to identify genes associated with PD 0332991 response. RESULTS: Cell lines representing luminal estrogen receptor-positive (ER+) subtype (including those that are HER2 amplified) were most sensitive to growth inhibition by PD 0332991 while nonluminal/basal subtypes were most resistant. Analysis of variance identified 450 differentially expressed genes between sensitive and resistant cells. pRb and cyclin D1 were elevated and CDKN2A (p16) was decreased in the most sensitive lines. Cell cycle analysis showed G0/G1 arrest in sensitive cell lines and Western blot analysis demonstrated that Rb phosphorylation is blocked in sensitive lines but not resistant lines. PD 0332991 was synergistic with tamoxifen and trastuzumab in ER+ and HER2-amplified cell lines, respectively. PD 0332991 enhanced sensitivity to tamoxifen in cell lines with conditioned resistance to ER blockade. CONCLUSIONS: These studies suggest a role for CDK4/6 inhibition in some breast cancers and identify criteria for patient selection in clinical studies of PD 0332991 PMID- 19874579 TI - Mary Crosse project: systematic reviews and grading the value of neonatal tests in predicting long term outcomes. AB - BACKGROUND: Events before birth, condition at birth, events immediately following birth, and condition in early childhood are linked together, and have implications for health and disease in adulthood. At present, there is lack of clarity about the tests that purport to link these various stages. This is partly because there is paucity of collated information about the best strategies for predicting longer-term outcomes before (using tests in fetal period) or after birth (using tests in neonatal period, infancy as well as early childhood). METHODS/DESIGN: A series of systematic reviews and meta-analyses will be undertaken to determine, amongst neonates, the ability of various tests and measures to predict infant, childhood and adult outcomes. We will search Medline, Embase, Cochrane Library, MEDION, citation lists of review articles and eligible primary articles and will contact experts in the field. Independent reviewers will select studies, extract data and assess study quality according to established criteria. Language restrictions will not be applied. Data synthesis will involve meta-analysis (where appropriate), exploration of heterogeneity and publication bias. Evidence collated will be graded for its quality to support decision making. DISCUSSION: The project will collate, synthesise and evaluate the available evidence concerning the value of tests of neonatal wellbeing to predict long term outcomes. The systematic reviews will assess the quality of available evidence and identify tests with the strongest association with outcomes, and assess their economic value. The output of this project will help formulate practice recommendations. PMID- 19874580 TI - The relationship between disease activity, sleep, psychiatric distress and pain sensitivity in rheumatoid arthritis: a cross-sectional study. AB - INTRODUCTION: Despite recent advances in anti-inflammatory therapy, rheumatoid arthritis (RA) patients continue to rate pain as a priority. The etiology of RA pain is likely multifactorial, including both inflammatory and non-inflammatory components. In this study, we examine the association between disease activity, sleep, psychiatric distress and pain sensitivity in RA. METHODS: Fifty-nine female RA patients completed questionnaires and underwent pressure pain threshold testing to assess hyperalgesia/allodynia at joint and non-joint sites. Blood samples were taken to measure C-reactive protein (CRP). The association between disease activity, sleep problems, psychiatric distress and pain threshold was assessed using Pearson/Spearman correlations and multivariable linear regression. Disease activity levels, sleep problems and psychiatric distress were compared between RA patients with fibromyalgia and RA patients without fibromyalgia. RESULTS: In unadjusted analyses, CRP was not correlated with pain threshold, but tender joint count was inversely correlated with pain threshold at all sites (P < or = 0.004). Sleep problems were associated with low pain threshold at all sites (P < or = 0.0008). Psychiatric distress was associated with low pain threshold at the wrist and thumbnail (P < or = 0.006). In multivariable linear regression models, CRP was inversely associated with wrist pain threshold (P = 0.003). Sleep problems were inversely associated with pain threshold at all sites (P < or = 0.01), but psychiatric distress was not. Despite differences in pain threshold, CRP levels and sleep problems between RA patients with fibromyalgia and those without fibromyalgia, associations between these variables did not change when patients with fibromyalgia were excluded. CONCLUSIONS: Multivariable models are essential in analyses of pain. Among RA patients, inflammation is associated with heightened pain sensitivity at joints. In contrast, poor sleep is associated with diffuse pain sensitivity, as noted in central pain conditions such as fibromyalgia. Future studies examining pain sensitivity at joint and non-joint sites may identify patients with different underlying pain mechanisms and suggest alternative approaches to treating RA pain. PMID- 19874581 TI - Impact of insecticide-treated nets on wild pyrethroid resistant Anopheles epiroticus population from southern Vietnam tested in experimental huts. AB - BACKGROUND: In this study, the efficacy of insecticide-treated nets was evaluated in terms of deterrence, blood-feeding inhibition, induced exophily and mortality on a wild resistant population of Anopheles epiroticus in southern Vietnam, in order to gain insight into the operational consequences of the insecticide resistance observed in this malaria vector in the Mekong delta. METHOD: An experimental station, based on the model of West Africa and adapted to the behaviour of the target species, was built in southern Vietnam. The study design was adapted from the WHO phase 2 guidelines. The study arms included a conventionally treated polyester net (CTN) with deltamethrin washed just before exhaustion, the WHO recommended long-lasting insecticidal net (LLIN) PermaNet 2.0 unwashed and 20 times washed and PermaNet 3.0, designed for the control of pyrethroid resistant vectors, unwashed and 20 times washed. RESULTS: The nets still provided personal protection against the resistant An. epiroticus population. The personal protection ranged from 67% for deltamethrin CTN to 85% for unwashed PermaNet 3.0. Insecticide resistance in the An. epiroticus mosquitoes did not seem to alter the deterrent effect of pyrethroids. A significant higher mortality was still observed among the treatment arms despite the fact that the An. epiroticus population is resistant against the tested insecticides. CONCLUSION: This study shows that CTN and LLINs still protect individuals against a pyrethroid resistant malaria vector from the Mekong region, where insecticide resistance is caused by a metabolic mechanism. In the light of a possible elimination of malaria from the Mekong region these insights in operational consequences of the insecticide resistance on control tools is of upmost importance. PMID- 19874582 TI - Incidence of propofol-related infusion syndrome in critically ill adults: a prospective, multicenter study. AB - INTRODUCTION: While propofol is associated with an infusion syndrome (PRIS) that may cause death, the incidence of PRIS is unknown. Determining the incidence of PRIS and the frequency of PRIS-related clinical manifestations are key steps prior to the completion of any controlled studies investigating PRIS. This prospective, multicenter study sought to determine the incidence of PRIS and PRIS related clinical manifestations in a large cohort of critically ill adults prescribed propofol. METHODS: Critically ill adults from 11 academic medical centers administered an infusion of propofol for [>or=] 24 hours were monitored at baseline and then on a daily basis until propofol was discontinued for the presence of 11 different PRIS-associated clinical manifestations and risk factors derived from 83 published case reports of PRIS. RESULTS: Among 1017 patients [medical (35%), neurosurgical (25%)], PRIS (defined as metabolic acidosis plus cardiac dysfunction and [>or=] 1 of: rhabdomyolysis, hypertriglyceridemia or renal failure occurring after the start of propofol therapy) developed in 11 (1.1%) patients an average of 3 (1-6) [median (range)] days after the start of propofol. While most (91%) of the patients who developed PRIS were receiving a vasopressor (80% initiated after the start of propofol therapy), few received a propofol dose >83 mcg/kg/min (18%) or died (18%). Compared to the 1006 patients who did not develop PRIS, the APACHE II score (25 +/- 6 vs 20 +/- 7, P = 0.01) was greater in patients with PRIS but both the duration of propofol use (P = 0.43) and ICU length of stay (P = 0.82) were similar. CONCLUSIONS: Despite using a conservative definition for PRIS, and only considering new-onset PRIS clinical manifestations, the incidence of PRIS slightly exceeds 1%. Future controlled studies focusing on evaluating whether propofol manifests the derangements of critical illness more frequently than other sedatives will need to be large. These studies should also investigate the mechanism(s) and risk factors for PRIS. PMID- 19874583 TI - Stimulation of glioma cell motility by expression, proteolysis, and release of the L1 neural cell recognition molecule. AB - BACKGROUND: Malignant glioma cells are particularly motile and can travel diffusely through the brain parenchyma, apparently without following anatomical structures to guide their migration. The neural adhesion/recognition protein L1 (L1CAM; CD171) has been implicated in contributing to stimulation of motility and metastasis of several non-neural cancer types. We explored the expression and function of L1 protein as a stimulator of glioma cell motility using human high grade glioma surgical specimens and established rat and human glioma cell lines. RESULTS: L1 protein expression was found in 17 out of 18 human high-grade glioma surgical specimens by western blotting. L1 mRNA was found to be present in human U-87/LacZ and rat C6 and 9L glioma cell lines. The glioma cell lines were negative for surface full length L1 by flow cytometry and high resolution immunocytochemistry of live cells. However, fixed and permeablized cells exhibited positive staining as numerous intracellular puncta. Western blots of cell line extracts revealed L1 proteolysis into a large soluble ectodomain (~180 kDa) and a smaller transmembrane proteolytic fragment (~32 kDa). Exosomal vesicles released by the glioma cell lines were purified and contained both full length L1 and the proteolyzed transmembrane fragment. Glioma cell lines expressed L1-binding alphavbeta5 integrin cell surface receptors. Quantitative time-lapse analyses showed that motility was reduced significantly in glioma cell lines by 1) infection with an antisense-L1 retroviral vector and 2) L1 ectodomain-binding antibodies. CONCLUSION: Our novel results support a model of autocrine/paracrine stimulation of cell motility in glioma cells by a cleaved L1 ectodomain and/or released exosomal vesicles containing L1. This mechanism could explain the diffuse migratory behavior of high-grade glioma cancer cells within the brain. PMID- 19874584 TI - Chlamydia trachomatis infection and sexual behaviour among female students attending higher education in the Republic of Ireland. AB - BACKGROUND: There are no prevalence data on Chlamydia trachomatis relating to female students attending higher education available for the Republic of Ireland. This information is required to guide on the necessity for Chlamydia screening programmes in higher education settings. This research aimed to determine the prevalence of and predictive risk factors for Chlamydia trachomatis genital infection among female higher education students in Ireland. METHODS: All females presenting during one-day periods at Student Health Units in three higher education institutions in two cities in the Republic of Ireland were invited to participate. Participants completed a questionnaire on lifestyle and socio demographic factors and provided a urine sample. Samples were tested for C. trachomatis DNA by a PCR based technique (Cobas Amplicor, Roche). To examine possible associations between a positive test and demographic and lifestyle risk factors, a univariate analysis was performed. All associations with a p value < 0.05 were included in a multivariate logistic regression analysis. RESULTS: Of the 460 sexually active participants 22 tested positive (prevalence 4.8%; 95% CI 3.0 to 7.1%). Variables associated with significantly increased risk were current suggestive symptoms, two or more one-night stands and three or more lifetime sexual partners. The students displayed high-risk sexual behaviour. CONCLUSION: The prevalence of C. trachomatis infection and the lack of awareness of the significance of suggestive symptoms among sexually experienced female students demonstrate the need for a programme to test asymptomatic or non-presenting higher education students. The risk factors identified by multivariate analysis may be useful in identifying those who are most likely to benefit from screening. Alcohol abuse, condom use, sexual behaviour (at home and abroad) and, knowledge of sexually transmitted infections (STIs) (including asymptomatic nature or relevant symptoms) were identified as target areas for health promotion strategies. These strategies are needed in view of the high-risk sexual activity identified. PMID- 19874585 TI - Predicting sulfotyrosine sites using the random forest algorithm with significantly improved prediction accuracy. AB - BACKGROUND: Tyrosine sulfation is one of the most important posttranslational modifications. Due to its relevance to various disease developments, tyrosine sulfation has become the target for drug design. In order to facilitate efficient drug design, accurate prediction of sulfotyrosine sites is desirable. A predictor published seven years ago has been very successful with claimed prediction accuracy of 98%. However, it has a particularly low sensitivity when predicting sulfotyrosine sites in some newly sequenced proteins. RESULTS: A new approach has been developed for predicting sulfotyrosine sites using the random forest algorithm after a careful evaluation of seven machine learning algorithms. Peptides are formed by consecutive residues symmetrically flanking tyrosine sites. They are then encoded using an amino acid hydrophobicity scale. This new approach has increased the sensitivity by 22%, the specificity by 3%, and the total prediction accuracy by 10% compared with the previous predictor using the same blind data. Meanwhile, both negative and positive predictive powers have been increased by 9%. In addition, the random forest model has an excellent feature for ranking the residues flanking tyrosine sites, hence providing more information for further investigating the tyrosine sulfation mechanism. A web tool has been implemented at http://ecsb.ex.ac.uk/sulfotyrosine for public use. CONCLUSION: The random forest algorithm is able to deliver a better model compared with the Hidden Markov Model, the support vector machine, artificial neural networks, and others for predicting sulfotyrosine sites. The success shows that the random forest algorithm together with an amino acid hydrophobicity scale encoding can be a good candidate for peptide classification. PMID- 19874586 TI - Clinical trial participant characteristics and saliva and DNA metrics. AB - BACKGROUND: Clinical trial and epidemiological studies need high quality biospecimens from a representative sample of participants to investigate genetic influences on treatment response and disease. Obtaining blood biospecimens presents logistical and financial challenges. As a result, saliva biospecimen collection is becoming more frequent because of the ease of collection and lower cost. This article describes an assessment of saliva biospecimen samples collected through the mail, trial participant demographic and behavioral characteristics, and their association with saliva and DNA quantity and quality. METHODS: Saliva biospecimens were collected using the Oragene(R) DNA Self Collection Kits from participants in a National Cancer Institute funded smoking cessation trial. Saliva biospecimens from 565 individuals were visually inspected for clarity prior to and after DNA extraction. DNA samples were then quantified by UV absorbance, PicoGreen(R), and qPCR. Genotyping was performed on 11 SNPs using TaqMan(R) SNP assays and two VNTR assays. Univariate, correlation, and analysis of variance analyses were conducted to observe the relationship between saliva sample and participant characteristics. RESULTS: The biospecimen kit return rate was 58.5% among those invited to participate (n = 967) and 47.1% among all possible COMPASS participants (n = 1202). Significant gender differences were observed with males providing larger saliva volume (4.7 vs. 4.5 ml, p = 0.019), samples that were more likely to be judged as cloudy (39.5% vs. 24.9%, p < 0.001), and samples with greater DNA yield as measured by UV (190.0 vs. 138.5, p = 0.002), but reduced % human DNA content (73.2 vs. 77.6 p = 0.005) than females. Other participant characteristics (age, self-identified ethnicity, baseline cigarettes per day) were associated with saliva clarity. Saliva volume and saliva and DNA clarity were positively correlated with total DNA yield by all three quantification measurements (all r > 0.21, P < 0.001), but negatively correlated with % human DNA content (saliva volume r = -0.148 and all P < 0.010). Genotyping completion rate was not influenced by saliva or DNA clarity. CONCLUSION: Findings from this study show that demographic and behavioral characteristics of smoking cessation trial participants have significant associations with saliva and DNA metrics, but not with the performance of TaqMan(R) SNP or VNTR genotyping assays. TRIAL REGISTRATION: COMPASS; registered as NCT00301145 at clinicaltrials.gov. PMID- 19874587 TI - Primary congenital anomalies of the coronary arteries and relation to atherosclerosis: an angiographic study in Lebanon. AB - BACKGROUND: Most coronary artery anomalies are congenital in origin. This study angiographically determined the prevalence of different forms of anomalous aortic origins of coronary anomalies and their anatomic variation in a selected adult Lebanese population. Correlation between these anomalies and stenotic coronary atherosclerotic disease was also investigated. METHODS: 4650 coronary angiographies were analyzed for anomalous aortic origin. These anomalies were clustered in four main groups: anomalous left circumflex (LCX) coronary artery, anomalous right coronary artery, anomalous left main coronary artery and anomalous left anterior descending coronary artery. RESULTS: Thirty four patients had anomalous aortic origin of coronary arteries. Of these, anomalous LCX coronary artery was the most common (19 of 34 patients). The second most common anomaly was anomalous RCA origin (9 of 34 patients.) The incidence of coronary stenosis in non-anomalous vessels was 50%. However, a significantly smaller percentage (17.46%; 6 of 34 patients) of anomalous vessels exhibited significant stenosis, reminiscent of atherosclerotic disease. Of these six vessels, five were LCX coronary artery arising from right coronary sinus or from early branch of right coronary artery. The sixth was right coronary artery arising from left coronary sinus. CONCLUSION: The incidence of congenital coronary anomalies in Lebanon is similar to other populations where the most common is the LCX coronary artery. Isolated congenital coronary anomalies do not increase the risk of developing coronary stenosis or atherosclerosis. Angiographic detection of these anomalies is clinically important for coronary angioplasty or cardiac surgery. PMID- 19874588 TI - The forsaken mental health of the Indigenous Peoples - a moral case of outrageous exclusion in Latin America. AB - BACKGROUND: Mental health is neglected in most parts of the world. For the Indigenous Peoples of Latin America, the plight is even more severe as there are no specific mental health services designed for them altogether. Given the high importance of mental health for general health, the status quo is unacceptable. Lack of research on the subject of Indigenous Peoples' mental health means that statistics are virtually unavailable. To illustrate their mental health status, one can nonetheless point to the high rates of poverty and extreme poverty in their communities, overcrowded housing, illiteracy, and lack of basic sanitary services such as water, electricity and sewage. At the dawn of the XXI century, they remain poor, powerless, and voiceless. They remain severely excluded from mainstream society despite being the first inhabitants of this continent and being an estimated of 48 million people. This paper comments, specifically, on the limited impact of the Pan American Health Organization's mental health initiative on the Indigenous Peoples of Latin America. DISCUSSION: The Pan American Health Organization's sponsored workshop "Programas y Servicios de Salud Mental en Communidades Indigenas" [Mental Health Programs and Services for the Indigenous Communities] in the city of Santa Cruz, Bolivia on July16 - 18, 1998, appeared promising. However, eleven years later, no specific mental health program has been designed nor developed for the Indigenous Peoples in Latin America. This paper makes four specific recommendations for improvements in the approach of the Pan American Health Organization: (1) focus activities on what can be done; (2) build partnerships with the Indigenous Peoples; (3) consider traditional healers as essential partners in any mental health effort; and (4) conduct basic research on the mental health status of the Indigenous Peoples prior to the programming of any mental health service. SUMMARY: The persistent neglect of the Indigenous Peoples' mental health in Latin America raises serious concerns of moral and human rights violations. Since the Pan American Health Organization' Health of the Indigenous Peoples Initiative 16 years ago, no mental health service designed for them has yet been created. PMID- 19874589 TI - A novel role of dendritic gap junction and mechanisms underlying its interaction with thalamocortical conductance in fast spiking inhibitory neurons. AB - BACKGROUND: Little is known about the roles of dendritic gap junctions (GJs) of inhibitory interneurons in modulating temporal properties of sensory induced responses in sensory cortices. Electrophysiological dual patch-clamp recording and computational simulation methods were used in combination to examine a novel role of GJs in sensory mediated feed-forward inhibitory responses in barrel cortex layer IV and its underlying mechanisms. RESULTS: Under physiological conditions, excitatory post-junctional potentials (EPJPs) interact with thalamocortical (TC) inputs within an unprecedented few milliseconds (i.e. over 200 Hz) to enhance the firing probability and synchrony of coupled fast-spiking (FS) cells. Dendritic GJ coupling allows fourfold increase in synchrony and a significant enhancement in spike transmission efficacy in excitatory spiny stellate cells. The model revealed the following novel mechanisms: 1) rapid capacitive current (Icap) underlies the activation of voltage-gated sodium channels; 2) there was less than 2 milliseconds in which the Icap underlying TC input and EPJP was coupled effectively; 3) cells with dendritic GJs had larger input conductance and smaller membrane response to weaker inputs; 4) synchrony in inhibitory networks by GJ coupling leads to reduced sporadic lateral inhibition and increased TC transmission efficacy. CONCLUSION: Dendritic GJs of neocortical inhibitory networks can have very powerful effects in modulating the strength and the temporal properties of sensory induced feed-forward inhibitory and excitatory responses at a very high frequency band (>200 Hz). Rapid capacitive currents are identified as main mechanisms underlying interaction between two transient synaptic conductances. PMID- 19874590 TI - The case for developing publicly-accessible datasets for health services research in the Middle East and North Africa (MENA) region. AB - BACKGROUND: The existence of publicly-accessible datasets comprised a significant opportunity for health services research to evolve into a science that supports health policy making and evaluation, proper inter- and intra-organizational decisions and optimal clinical interventions. This paper investigated the role of publicly-accessible datasets in the enhancement of health care systems in the developed world and highlighted the importance of their wide existence and use in the Middle East and North Africa (MENA) region. DISCUSSION: A search was conducted to explore the availability of publicly-accessible datasets in the MENA region. Although datasets were found in most countries in the region, those were limited in terms of their relevance, quality and public-accessibility. With rare exceptions, publicly-accessible datasets - as present in the developed world - were absent. Based on this, we proposed a gradual approach and a set of recommendations to promote the development and use of publicly-accessible datasets in the region. These recommendations target potential actions by governments, researchers, policy makers and international organizations. SUMMARY: We argue that the limited number of publicly-accessible datasets in the MENA region represents a lost opportunity for the evidence-based advancement of health systems in the region. The availability and use of publicly-accessible datasets would encourage policy makers in this region to base their decisions on solid representative data and not on estimates or small-scale studies; researchers would be able to exercise their expertise in a meaningful manner to both, policy makers and the public. The population of the MENA countries would exercise the right to benefit from locally- or regionally-based studies, versus imported and in 'best cases' customized ones. Furthermore, on a macro scale, the availability of regionally comparable publicly-accessible datasets would allow for the exploration of regional variations and benchmarking studies. PMID- 19874591 TI - Sex and hand differences in circadian wrist activity are independent from sex and hand differences in 2D:4D. AB - BACKGROUND: We investigated the relationship between patterns of sex and hand differences in circadian wrist activity and digit ratio, a marker for prenatal androgen exposure. If the contribution of prenatal androgen exposure to sex differences in digit ratio underlies sex differences in circadian wrist activity, we predict that patterns of wrist activity will be correlated with digit ratio. METHODS: Bilateral wrist activity of male and female college students was measured for three consecutive days. Digit ratio was obtained from photocopy measurements of the second and fourth fingers of each subject. RESULTS: Males had lower digit ratios with more pronounced differences on the right hand. Female acrophase occurred earlier than male acrophase. There was more activity in the right hand and right hand activity peaked before the left. Digit ratio was not correlated with any measure of wrist activity. An analysis of activity by age revealed that younger female students exhibited more male-like activity patterns. CONCLUSION: Sex and hand differences for digit ratio and acrophase replicated previous findings. The lack of correlation between digit ratio and patterns of wrist activity suggests that sexually dimorphic circadian activity develops independently from the mechanisms of hormone exposure that cause sex differences in digit ratio. PMID- 19874592 TI - In vivo evidence that truncated trkB.T1 participates in nociception. AB - Brain-Derived Neurotrophic Factor (BDNF) is a central nervous system modulator of nociception. In animal models of chronic pain, BDNF exerts its effects on nociceptive processing by binding to the full-length receptor tropomyosin-related kinase B (trkB.FL) and transducing intracellular signaling to produce nocifensive behaviors. In addition to trkB.FL, the trkB locus also produces a widely expressed alternatively-spliced truncated isoform, trkB.T1. TrkB.T1 binds BDNF with high affinity; however the unique 11 amino acid intracellular cytoplasmic tail lacks the kinase domain of trkB.FL. Recently, trkB.T1 was shown to be specifically up-regulated in a model of HIV-associated neuropathic pain, potentially implicating trkB.T1 as a modulator of nociception. Here, we report that trkB.T1 mRNA and protein is up-regulated in the spinal dorsal horn at times following antiretroviral drug treatment and hind paw inflammation in which nocifensive behaviors develop. While genetic depletion of trkB.T1 did not affect baseline mechanical and thermal thresholds, the absence of trkB.T1 resulted in significant attenuation of inflammation- and antiretroviral-induced nocifensive behaviors. Our results suggest that trkB.T1 up-regulation following antiretroviral treatment and tissue inflammation participates in the development and maintenance of nocifensive behavior and may represent a novel therapeutic target for pain treatment. PMID- 19874593 TI - Repetitive H-wave device stimulation and program induces significant increases in the range of motion of post operative rotator cuff reconstruction in a double blinded randomized placebo controlled human study. AB - BACKGROUND: Albeit other prospective randomized controlled clinical trials on H Wave device stimulation (HWDS), this is the first randomized double-blind placebo controlled prospective study that assessed the effects of HWDS on range of motion and strength testing in patients who underwent rotator cuff reconstruction. METHODS: Twenty-two patients were randomly assigned into one of two groups: 1) H Wave device stimulation (HWDS); 2) sham-placebo device (PLACEBO). All groups received the same postoperative dressing and the same device treatment instructions. Group I was given HWDS which they were to utilize for one hour twice a day for 90 days postoperatively. Group II was given the same instructions with a Placebo device (PLACEBO). Range of motion was assessed by using one-way ANOVA with a Duncan Multiple Range Test for differences between the groups preoperatively, 45 days postoperatively, and 90 days postoperatively by using an active/passive scale for five basic ranges of motions: Forward Elevation, External Rotation (arm at side), External Rotation (arm at 90 degrees abduction), Internal Rotation (arm at side), and Internal Rotation (arm at 90 degrees abduction). The study also evaluated postoperative changes in strength by using the Medical Research Council (MRC) grade assessed strength testing. RESULTS: Patients who received HWDS compared to PLACEBO demonstrated, on average, significantly improved range of motion. Results confirm a significant difference for external rotation at 45 and 90 days postoperatively; active range at 45 days postoperatively (p = 0.007), active at 90 days postoperatively (p = 0.007). Internal rotation also demonstrated significant improvement compared to PLACEBO at 45 and 90 days postoperatively; active range at 45 days postoperatively (p = 0.007), and active range at 90 days postoperatively (p = 0.006). There was no significant difference between the two groups for strength testing. CONCLUSION: HWDS compared to PLACEBO induces a significant increase in range of motion in positive management of rotator cuff reconstruction, supporting other previous research on HWDS and improvement in function. Interpretation of this preliminary investigation while suggestive of significant increases in Range of Motion of Post -Operative Rotator Cuff Reconstruction, warrants further confirmation in a larger double-blinded sham controlled randomized study. PMID- 19874594 TI - Empirical evaluation of the inter-relationship of articular elements involved in the pathoanatomy of knee osteoarthritis using magnetic resonance imaging. AB - BACKGROUND: In this cross-sectional study, we conducted a comprehensive assessment of all articular elements that could be measured using knee MRI. We assessed the association of pathological change in multiple articular structures involved in the pathoanatomy of osteoarthritis. METHODS: Knee MRI scans from patients over 45 years old were assessed using a semi-quantitative knee MRI assessment form. The form included six distinct elements: cartilage, bone marrow lesions, osteophytes, subchondral sclerosis, joint effusion and synovitis. Each type of pathology was graded using an ordinal scale with a value of zero indicating no pathology and higher values indicating increasingly severe levels of pathology. The principal dependent variable for comparison was the mean cartilage disease score (CDS), which captured the aggregate extent of involvement of articular cartilage. The distribution of CDS was compared to the individual and cumulative distributions of each articular element using the Chi-squared test. The correlations between pathological change in the various articular structures were assessed in a Spearman correlation table. RESULTS: Data from 140 patients were available for review. The cohort had a median age of 61 years (range 45-89) and was 61% female. The cohort included a wide spectrum of OA severity. Our analysis showed a statistically significant trend towards pathological change involving more articular elements as CDS worsened (p-value for trend < 0.0001). Comparison of CDS to change in the severity of pathology of individual articular elements showed statistically significant trends towards more severe pathology as CDS worsened for osteophytes (p-value for trend < 0.0001), bone marrow lesions (p = 0.0003), and subchondral sclerosis (p = 0.009), but not joint effusion or synovitis. There was a moderate correlation between cartilage damage, osteophytes and BMLs as well as a moderate correlation between joint effusion and synovitis. However, cartilage damage and osteophytes were only weakly associated with synovitis or joint effusion. CONCLUSION: Our results support an inter-relationship of multiple articular elements in the pathoanatomy of knee OA. Prospective studies of OA pathogenesis in humans are needed to correlate these findings to clinically relevant outcomes such as pain and function. PMID- 19874595 TI - A retrospective cohort pilot study to evaluate a triage tool for use in a pandemic. AB - INTRODUCTION: The objective of this pilot study was to assess the usability of the draft Ontario triage protocol, to estimate its potential impact on patient outcomes, and ability to increase resource availability based on a retrospective cohort of critically ill patients cared for during a non-pandemic period. METHODS: Triage officers applied the protocol prospectively to 2 retrospective cohorts of patients admitted to 2 academic medical/surgical ICUs during an 8 week period of peak occupancy. Each patient was assigned a treatment priority (red -- 'highest', yellow -- 'intermediate', green -- 'discharge to ward', or blue/black - 'expectant') by the triage officers at 3 separate time points (at the time of admission to the ICU, 48, and 120 hours post admission). RESULTS: Overall, triage officers were either confident or very confident in 68.4% of their scores; arbitration was required in 54.9% of cases. Application of the triage protocol would potentially decrease the number of required ventilator days by 49.3% (568 days) and decrease the total ICU days by 52.6% (895 days). On the triage protocol at ICU admission the survival rate in the red (93.7%) and yellow (62.5%) categories were significantly higher then that of the blue category (24.6%) with associated P values of < 0.0001 and 0.0003 respectively. Further, the survival rate of the red group was significantly higher than the overall survival rate of 70.9% observed in the cohort (P < 0.0001). At 48 and 120 hours, survival rates in the blue group increased but remained lower then the red or yellow groups. CONCLUSIONS: Refinement of the triage protocol and implementation is required prior to future study, including improved training of triage officers, and protocol modification to minimize the exclusion from critical care of patients who may in fact benefit. However, our results suggest that the triage protocol can help to direct resources to patients who are most likely to benefit, and help to decrease the demands on critical care resources, thereby making available more resources to treat other critically ill patients. PMID- 19874596 TI - BARCRAWL and BARTAB: software tools for the design and implementation of barcoded primers for highly multiplexed DNA sequencing. AB - BACKGROUND: Advances in automated DNA sequencing technology have greatly increased the scale of genomic and metagenomic studies. An increasingly popular means of increasing project throughput is by multiplexing samples during the sequencing phase. This can be achieved by covalently linking short, unique "barcode" DNA segments to genomic DNA samples, for instance through incorporation of barcode sequences in PCR primers. Although several strategies have been described to insure that barcode sequences are unique and robust to sequencing errors, these have not been integrated into the overall primer design process, thus potentially introducing bias into PCR amplification and/or sequencing steps. RESULTS: Barcrawl is a software program that facilitates the design of barcoded primers, for multiplexed high-throughput sequencing. The program bartab can be used to deconvolute DNA sequence datasets produced by the use of multiple barcoded primers. This paper describes the functions implemented by barcrawl and bartab and presents a proof-of-concept case study of both programs in which barcoded rRNA primers were designed and validated by high-throughput sequencing. CONCLUSION: Barcrawl and bartab can benefit researchers who are engaged in metagenomic projects that employ multiplexed specimen processing. The source code is released under the GNU general public license and can be accessed at http://www.phyloware.com. PMID- 19874597 TI - Engineering an efficient secretion of leech carboxypeptidase inhibitor in Escherichia coli. AB - BACKGROUND: Despite advances in expression technologies, the efficient production of heterologous secreted proteins in Escherichia coli remains a challenge. One frequent limitation relies on their inability to be exported to the E. coli periplasm. However, recent studies have suggested that translational kinetics and signal sequences act in concert to modulate the export process. RESULTS: In order to produce leech carboxypeptidase inhibitor (LCI) in the bacterial periplasm, we compared expression of the natural and optimized gene sequences, and evaluated export efficiency of LCI fused to different signal sequences. The best combination of these factors acting on translation and export was obtained when the signal sequence of DsbA was fused to an E. coli codon-optimized mature LCI sequence. When tested in high cell density cultures, the protein was primarily found in the growth medium. Under these conditions, the engineered expression system yields over 470 mg.l-1 of purified active LCI. CONCLUSION: These results support the hypothesis that heterologous secreted proteins require proper coupling between translation and translocation for optimal high-level production in E. coli. PMID- 19874598 TI - WHO global survey on maternal and perinatal health in Latin America: classifying caesarean sections. AB - BACKGROUND: Caesarean section rates continue to increase worldwide with uncertain medical consequences. Auditing and analysing caesarean section rates and other perinatal outcomes in a reliable and continuous manner is critical for understanding reasons caesarean section changes over time. METHODS: We analyzed data on 97,095 women delivering in 120 facilities in 8 countries, collected as part of the 2004-2005 Global Survey on Maternal and Perinatal Health in Latin America. The objective of this analysis was to test if the "10-group" or "Robson" classification could help identify which groups of women are contributing most to the high caesarean section rates in Latin America, and if it could provide information useful for health care providers in monitoring and planning effective actions to reduce these rates. RESULTS: The overall rate of caesarean section was 35.4%. Women with single cephalic pregnancy at term without previous caesarean section who entered into labour spontaneously (groups 1 and 3) represented 60% of the total obstetric population. Although women with a term singleton cephalic pregnancy with a previous caesarean section (group 5) represented only 11.4% of the obstetric population, this group was the largest contributor to the overall caesarean section rate (26.7% of all the caesarean sections). The second and third largest contributors to the overall caesarean section rate were nulliparous women with single cephalic pregnancy at term either in spontaneous labour (group 1) or induced or delivered by caesarean section before labour (group 2), which were responsible for 18.3% and 15.3% of all caesarean deliveries, respectively. CONCLUSION: The 10-group classification could be easily applied to a multicountry dataset without problems of inconsistencies or misclassification. Specific groups of women were clearly identified as the main contributors to the overall caesarean section rate. This classification could help health care providers to plan practical and effective actions targeting specific groups of women to improve maternal and perinatal care. PMID- 19874599 TI - Predictors of initiation and persistence of unhealthy weight control behaviours in adolescents. AB - BACKGROUND: Unhealthy weight control behaviours (UWCB) among adolescents have significant health and weight consequences. The current longitudinal study aimed to identify personal and socio-environmental predictors of initiation or persistence of adolescent UWCB, in order to inform development of programs aimed at both preventing and stopping UWCB. METHODS: A diverse sample included 1106 boys and 1362 girls from 31 middle schools and high schools in the United States who were enrolled in Project EAT (Eating Among Teens). Project EAT explored personal, behavioural, and socio-environmental factors associated with dietary intake and body weight in adolescence. Participants completed questionnaires to assess demographics, UWCB (including several methods of food restriction, purging by vomiting or medications, smoking to control weight, or food substitutions) and personal and socio-environmental variables at two time points, five years apart, between 1998 and 2004. Logistic regression models examined personal and socio environmental predictors of initiation and persistence of UWCB among Project EAT participants. RESULTS: Results indicate that 15.5% of boys and 19.7% of girls initiated UWCB by Time 2, and 15.9% of boys and 43.3% of girls persisted with these behaviours from Time 1 to Time 2. After controlling for race/ethnicity and weight status changes between assessments, logistic regression models indicated that similar factors and patterns of factors were associated significantly with initiation and persistence of UWCB. For both boys and girls, personal factors had more predictive value than socio-environmental factors (Initiation models: for boys: R2 = 0.35 for personal vs. 0.27 for socio-environmental factors; for girls, R2 = 0.46 for personal vs. 0.26 for socio-environmental factors. Persistence models: for boys: R2 = 0.53 for personal vs. 0.33 for socio-environmental factors; for girls, R2 = 0.41 for personal vs. 0.19 for socio-environmental factors). The weight concerns model was the strongest predictor among all individual models [Initiation odds ratios (ORs) and 95% confidence interval (CI): 4.84 (3.32-7.01) for boys and 5.09 (3.55-7.30) for girls; persistence OR (CI): 4.55 (2.86-7.14) for boys and 3.45 (2.50-4.76) for girls]. CONCLUSION: In general, predictors of initiation and persistence of UWCB were similar, suggesting that universal and selective prevention programs can target similar risk factors. PMID- 19874600 TI - Environmental stresses inhibit splicing in the aquatic fungus Blastocladiella emersonii. AB - BACKGROUND: Exposure of cells to environmental stress conditions can lead to the interruption of several intracellular processes, in particular those performed by macromolecular complexes such as the spliceosome. RESULTS: During nucleotide sequencing of cDNA libraries constructed using RNA isolated from B. emersonii cells submitted to heat shock and cadmium stress, a large number of ESTs with retained introns was observed. Among the 6,350 ESTs obtained through sequencing of stress cDNA libraries, 181 ESTs presented putative introns (2.9%), while sequencing of cDNA libraries from unstressed B. emersonii cells revealed only 0.2% of ESTs containing introns. These data indicate an enrichment of ESTs with introns in B. emersonii stress cDNA libraries. Among the 85 genes corresponding to the ESTs that retained introns, 19 showed more than one intron and three showed three introns, with intron length ranging from 55 to 333 nucleotides. Canonical splicing junctions were observed in most of these introns, junction sequences being very similar to those found in introns from genes previously characterized in B. emersonii, suggesting that inhibition of splicing during stress is apparently a random process. Confirming our observations, analyses of gpx3 and hsp70 mRNAs by Northern blot and S1 protection assays revealed a strong inhibition of intron splicing in cells submitted to cadmium stress. CONCLUSION: In conclusion, data indicate that environmental stresses, particularly cadmium treatment, inhibit intron processing in B. emersonii, revealing a new adaptive response to cellular exposure to this heavy metal. PMID- 19874601 TI - A novel R-package graphic user interface for the analysis of metabonomic profiles. AB - BACKGROUND: Analysis of the plethora of metabolites found in the NMR spectra of biological fluids or tissues requires data complexity to be simplified. We present a graphical user interface (GUI) for NMR-based metabonomic analysis. The "Metabonomic Package" has been developed for metabonomics research as open-source software and uses the R statistical libraries. RESULTS: The package offers the following options: Raw 1-dimensional spectra processing: phase, baseline correction and normalization. Importing processed spectra. Including/excluding spectral ranges, optional binning and bucketing, detection and alignment of peaks. Sorting of metabolites based on their ability to discriminate, metabolite selection, and outlier identification. Multivariate unsupervised analysis: principal components analysis (PCA). Multivariate supervised analysis: partial least squares (PLS), linear discriminant analysis (LDA), k-nearest neighbor classification. Neural networks.Visualization and overlapping of spectra. Plot values of the chemical shift position for different samples. Furthermore, the "Metabonomic" GUI includes a console to enable other kinds of analyses and to take advantage of all R statistical tools. CONCLUSION: We made complex multivariate analysis user-friendly for both experienced and novice users, which could help to expand the use of NMR-based metabonomics. PMID- 19874602 TI - Value of eight-amino-acid matches in predicting the allergenicity status of proteins: an empirical bioinformatic investigation. AB - The use of biotechnological techniques to introduce novel proteins into food crops (transgenic or GM crops) has motivated investigation into the properties of proteins that favor their potential to elicit allergic reactions. As part of the allergenicity assessment, bioinformatic approaches are used to compare the amino acid sequence of candidate proteins with sequences in a database of known allergens to predict potential cross reactivity between novel food proteins and proteins to which people have become sensitized. Two criteria commonly used for these queries are searches over 80-amino-acid stretches for >35% identity, and searches for 8-amino-acid contiguous matches. We investigated the added value provided by the 8-amino-acid criterion over that provided by the >35%-identity over-80-amino-acid criterion, by identifying allergens pairs that only met the former criterion, but not the latter criterion. We found that the allergen sequence pairs only sharing 8-amino-acid identity, but not >35% identity over 80 amino acids, were unlikely to be cross reactive allergens. Thus, the common search for 8-amino-acid identity between novel proteins and known allergens appears to be of little additional value in assessing the potential allergenicity of novel proteins. PMID- 19874603 TI - A multi-component model of the dynamics of salt-induced hypertension in Dahl-S rats. AB - BACKGROUND: In humans, salt intake has been suggested to influence blood pressure (BP) on a wide range of time scales ranging from several hours or days to many months or years. Detailed time course data collected in the Dahl salt-sensitive rat strain suggest that the development of salt-induced hypertension may consist of several distinct phases or components that differ in their timing and reversibility. To better understand these components, the present study sought to model the dynamics of salt-induced hypertension in the Dahl salt sensitive (Dahl S) rat using 3 sets of time course data. RESULTS: The first component of the model ("Acute-Reversible") consisted of a linear transfer function to account for the rapid and reversible effects of salt on BP (ie. acute salt sensitivity, corresponding with a depressed slope of the chronic pressure natriuresis relationship). For the second component ("Progressive-Irreversible"), an integrator function was used to represent the relatively slow, progressive, and irreversible effect of high salt intake on BP (corresponding with a progressive salt-induced shift of the chronic pressure natriuresis relationship to higher BP levels). A third component ("Progressive-Reversible") consisted of an effect of high salt intake to progressively increase the acute salt-sensitivity of BP (ie. reduce the slope of the chronic pressure natriuresis relationship), amounting to a slow and progressive, yet reversible, component of salt-induced hypertension. While the 3 component model was limited in its ability to follow the BP response to rapid and/or brief transitions in salt intake, it was able to accurately follow the slower steady state components of salt-induced BP changes. This model exhibited low values of mean absolute error (1.92 +/- 0.23, 2.13 +/- 0.37, 2.03 +/- 0.3 mmHg for data sets 1 - 3), and its overall performance was significantly improved over that of an initial model having only 2 components. The 3 component model performed well when applied to data from hybrids of Dahl salt sensitive and Dahl salt resistant rats in which salt sensitivity varied greatly in its extent and character (mean absolute error = 1.11 +/- 0.08 mmHg). CONCLUSION: Our results suggest that the slow process of development of salt-induced hypertension in Dahl S rats over a period of many weeks can be well represented by a combination of three components that differ in their timing, reversibility, and their associated effect on the chronic pressure natriuresis relationship. These components are important to distinguish since each may represent a unique set of underlying mechanisms of salt-induced hypertension. PMID- 19874604 TI - Saliva as an alternative source of high yield canine genomic DNA for genotyping studies. AB - BACKGROUND: The domestic dog presents an attractive model system for the study of the genetic basis of disease. The development of resources such as the canine genome sequence and SNP genotyping platforms has allowed for the implementation of canine genetic studies. Successful implementation of such studies depends not only on the quality of individual DNA samples, but also on the number of samples obtained. The latter can be maximized using a non-invasive DNA collection method that can increase study participation. We compared the DNA yield and quality obtained from blood and buccal swabs to those obtained using a non-invasive saliva collection kit (Oragene *ANIMAL kit). We also assessed the success rate of PCR amplification and genotyping accuracy of DNA isolated using these collection methods. FINDINGS: Comparison of DNA yields from matched saliva, blood and buccal swab samples showed that yields from saliva were significantly higher than those from blood (p = 0.0198) or buccal swabs (p = 0.0008). Electrophoretic analysis revealed that blood and saliva produced higher quality DNA than buccal swabs. In addition, a 1.1-kb PCR fragment was successfully amplified using the paired DNA samples and genotyping by PCR-RFLP yielded identical results. CONCLUSION: We demonstrate that DNA yields from canine saliva are higher than those from blood or buccal swabs. The quality of DNA extracted from saliva is sufficient for successful amplification of a 1.1-kb fragment and for accurate SNP genotyping by PCR-RFLP. We conclude that saliva presents a non-invasive alternative source of high quantities of canine genomic DNA suitable for genotyping studies. PMID- 19874605 TI - Cerebellar Purkinje cells incorporate immunoglobulins and immunotoxins in vitro: implications for human neurological disease and immunotherapeutics. AB - BACKGROUND: Immunoglobulin G (IgG) antibodies reactive with intracellular neuronal proteins have been described in paraneoplastic and other autoimmune disorders. Because neurons have been thought impermeable to immunoglobulins, however, such antibodies have been considered unable to enter neurons and bind to their specific antigens during life. Cerebellar Purkinje cells - an important target in paraneoplastic and other autoimmune diseases - have been shown in experimental animals to incorporate a number of molecules from cerebrospinal fluid. IgG has also been detected in Purkinje cells studied post mortem. Despite the possible significance of these findings for human disease, immunoglobulin uptake by Purkinje cells has not been demonstrated in living tissue or studied systematically. METHODS: To assess Purkinje cell uptake of immunoglobulins, organotypic cultures of rat cerebellum incubated with rat IgGs, human IgG, fluorescein-conjugated IgG, and rat IgM were studied by confocal microscopy in real time and following fixation. An IgG-daunorubicin immunotoxin was used to determine whether conjugation of pharmacological agents to IgG could be used to achieve Purkinje cell-specific drug delivery. RESULTS: IgG uptake was detected in Purkinje cell processes after 4 hours of incubation and in Purkinje cell cytoplasm and nuclei by 24-48 hours. Uptake could be followed in real time using IgG-fluorochrome conjugates. Purkinje cells also incorporated IgM. Intracellular immunoglobulin did not affect Purkinje cell viability, and Purkinje cells cleared intracellular IgG or IgM within 24-48 hours after transfer to media lacking immunoglobulins. The IgG-daunomycin immunotoxin was also rapidly incorporated into Purkinje cells and caused extensive, cell-specific death within 8 hours. Purkinje cell death was not produced by unconjugated daunorubicin or control IgG. CONCLUSION: Purkinje cells in rat organotypic cultures incorporate and clear host (rat) and non-host (human or donkey) IgG or IgM, independent of the immunoglobulin's reactivity with Purkinje cell antigens. This property permits real-time study of immunoglobulin-Purkinje cell interaction using fluorochrome IgG conjugates, and can allow Purkinje cell-specific delivery of IgG-conjugated pharmacological agents. Antibodies to intracellular Purkinje cell proteins could potentially be incorporated intracellularly to produce cell injury. Antibodies used therapeutically, including immunotoxins, may also be taken up and cause Purkinje cell injury, even if they do not recognize Purkinje cell antigens. PMID- 19874606 TI - iTriplet, a rule-based nucleic acid sequence motif finder. AB - BACKGROUND: With the advent of high throughput sequencing techniques, large amounts of sequencing data are readily available for analysis. Natural biological signals are intrinsically highly variable making their complete identification a computationally challenging problem. Many attempts in using statistical or combinatorial approaches have been made with great success in the past. However, identifying highly degenerate and long (>20 nucleotides) motifs still remains an unmet challenge as high degeneracy will diminish statistical significance of biological signals and increasing motif size will cause combinatorial explosion. In this report, we present a novel rule-based method that is focused on finding degenerate and long motifs. Our proposed method, named iTriplet, avoids costly enumeration present in existing combinatorial methods and is amenable to parallel processing. RESULTS: We have conducted a comprehensive assessment on the performance and sensitivity-specificity of iTriplet in analyzing artificial and real biological sequences in various genomic regions. The results show that iTriplet is able to solve challenging cases. Furthermore we have confirmed the utility of iTriplet by showing it accurately predicts polyA-site-related motifs using a dual Luciferase reporter assay. CONCLUSION: iTriplet is a novel rule based combinatorial or enumerative motif finding method that is able to process highly degenerate and long motifs that have resisted analysis by other methods. In addition, iTriplet is distinguished from other methods of the same family by its parallelizability, which allows it to leverage the power of today's readily available high-performance computing systems. PMID- 19874607 TI - The effect of provider- and workflow-focused strategies for guideline implementation on provider acceptance. AB - BACKGROUND: The effective implementation of clinical practice guidelines (CPGs) depends critically on the extent to which the strategies that are deployed for implementing the guidelines promote provider acceptance of CPGs. Such implementation strategies can be classified into two types based on whether they primarily target providers (e.g., academic detailing, grand rounds presentations) or the work context (e.g., computer reminders, modifications to forms). This study investigated the independent and joint effects of these two types of implementation strategies on provider acceptance of CPGs. METHODS: Surveys were mailed to a national sample of providers (primary care physicians, physician assistants, nurses, and nurse practitioners) and quality managers selected from Veterans Affairs Medical Centers (VAMCs). A total of 2,438 providers and 242 quality managers from 123 VAMCs participated. Survey items measured implementation strategies and provider acceptance (e.g., guideline-related knowledge, attitudes, and adherence) for three sets of CPGs--chronic obstructive pulmonary disease, chronic heart failure, and major depressive disorder. The relationships between implementation strategy types and provider acceptance were tested using multi-level analytic models. RESULTS: For all three CPGs, provider acceptance increased with the number of implementation strategies of either type. Moreover, the number of workflow-focused strategies compensated (contributing more strongly to provider acceptance) when few provider-focused strategies were used. CONCLUSION: Provider acceptance of CPGs depends on the type of implementation strategies used. Implementation effectiveness can be improved by using both workflow-focused as well as provider-focused strategies. PMID- 19874608 TI - pISTil: a pipeline for yeast two-hybrid Interaction Sequence Tags identification and analysis. AB - BACKGROUND: High-throughput screening of protein-protein interactions opens new systems biology perspectives for the comprehensive understanding of cell physiology in normal and pathological conditions. In this context, yeast two hybrid system appears as a promising approach to efficiently reconstruct protein interaction networks at the proteome-wide scale. This protein interaction screening method generates a large amount of raw sequence data, i.e. the ISTs (Interaction Sequence Tags), which urgently need appropriate tools for their systematic and standardised analysis. FINDINGS: We develop pISTil, a bioinformatics pipeline combined with a user-friendly web-interface: (i) to establish a standardised system to analyse and to annotate ISTs generated by two hybrid technologies with high performance and flexibility and (ii) to provide high-quality protein-protein interaction datasets for systems-level approach. This pipeline has been validated on a large dataset comprising more than 11.000 ISTs. As a case study, a detailed analysis of ISTs obtained from yeast two-hybrid screens of Hepatitis C Virus proteins against human cDNA libraries is also provided. CONCLUSION: We have developed pISTil, an open source pipeline made of a collection of several applications governed by a Perl script. The pISTil pipeline is intended to laboratories, with IT-expertise in system administration, scripting and database management, willing to automatically process large amount of ISTs data for accurate reconstruction of protein interaction networks in a systems biology perspective. pISTil is publicly available for download at http://sourceforge.net/projects/pistil. PMID- 19874609 TI - multiplierz: an extensible API based desktop environment for proteomics data analysis. AB - BACKGROUND: Efficient analysis of results from mass spectrometry-based proteomics experiments requires access to disparate data types, including native mass spectrometry files, output from algorithms that assign peptide sequence to MS/MS spectra, and annotation for proteins and pathways from various database sources. Moreover, proteomics technologies and experimental methods are not yet standardized; hence a high degree of flexibility is necessary for efficient support of high- and low-throughput data analytic tasks. Development of a desktop environment that is sufficiently robust for deployment in data analytic pipelines, and simultaneously supports customization for programmers and non programmers alike, has proven to be a significant challenge. RESULTS: We describe multiplierz, a flexible and open-source desktop environment for comprehensive proteomics data analysis. We use this framework to expose a prototype version of our recently proposed common API (mzAPI) designed for direct access to proprietary mass spectrometry files. In addition to routine data analytic tasks, multiplierz supports generation of information rich, portable spreadsheet-based reports. Moreover, multiplierz is designed around a "zero infrastructure" philosophy, meaning that it can be deployed by end users with little or no system administration support. Finally, access to multiplierz functionality is provided via high-level Python scripts, resulting in a fully extensible data analytic environment for rapid development of custom algorithms and deployment of high throughput data pipelines. CONCLUSION: Collectively, mzAPI and multiplierz facilitate a wide range of data analysis tasks, spanning technology development to biological annotation, for mass spectrometry-based proteomics research. PMID- 19874610 TI - Inferring branching pathways in genome-scale metabolic networks. AB - BACKGROUND: A central problem in computational metabolic modelling is how to find biochemically plausible pathways between metabolites in a metabolic network. Two general, complementary frameworks have been utilized to find metabolic pathways: constraint-based modelling and graph-theoretical path finding approaches. In constraint-based modelling, one aims to find pathways where metabolites are balanced in a pseudo steady-state. Constraint-based methods, such as elementary flux mode analysis, have typically a high computational cost stemming from a large number of steady-state pathways in a typical metabolic network. On the other hand, graph-theoretical approaches avoid the computational complexity of constraint-based methods by solving a simpler problem of finding shortest paths. However, while scaling well with network size, graph-theoretic methods generally tend to return more false positive pathways than constraint-based methods. RESULTS: In this paper, we introduce a computational method, ReTrace, for finding biochemically relevant, branching metabolic pathways in an atom-level representation of metabolic networks. The method finds compact pathways which transfer a high fraction of atoms from source to target metabolites by considering combinations of linear shortest paths. In contrast to current steady state pathway analysis methods, our method scales up well and is able to operate on genome-scale models. Further, we show that the pathways produced are biochemically meaningful by an example involving the biosynthesis of inosine 5' monophosphate (IMP). In particular, the method is able to avoid typical problems associated with graph-theoretic approaches such as the need to define side metabolites or pathways not carrying any net carbon flux appearing in results. Finally, we discuss an application involving reconstruction of amino acid pathways of a recently sequenced organism demonstrating how measurement data can be easily incorporated into ReTrace analysis. ReTrace is licensed under GPL and is freely available for academic use at http://www.cs.helsinki.fi/group/sysfys/software/retrace/. CONCLUSION: ReTrace is a useful method in metabolic path finding tasks, combining some of the best aspects in constraint-based and graph-theoretic methods. It finds use in a multitude of tasks ranging from metabolic engineering to metabolic reconstruction of recently sequenced organisms. PMID- 19874611 TI - 13C-metabolic flux ratio and novel carbon path analyses confirmed that Trichoderma reesei uses primarily the respirative pathway also on the preferred carbon source glucose. AB - BACKGROUND: The filamentous fungus Trichoderma reesei is an important host organism for industrial enzyme production. It is adapted to nutrient poor environments where it is capable of producing large amounts of hydrolytic enzymes. In its natural environment T. reesei is expected to benefit from high energy yield from utilization of respirative metabolic pathway. However, T. reesei lacks metabolic pathway reconstructions and the utilization of the respirative pathway has not been investigated on the level of in vivo fluxes. RESULTS: The biosynthetic pathways of amino acids in T. reesei supported by genome-level evidence were reconstructed with computational carbon path analysis. The pathway reconstructions were a prerequisite for analysis of in vivo fluxes. The distribution of in vivo fluxes in both wild type strain and cre1, a key regulator of carbon catabolite repression, deletion strain were quantitatively studied by performing 13C-labeling on both repressive carbon source glucose and non-repressive carbon source sorbitol. In addition, the 13C-labeling on sorbitol was performed both in the presence and absence of sophorose that induces the expression of cellulase genes. Carbon path analyses and the 13C-labeling patterns of proteinogenic amino acids indicated high similarity between biosynthetic pathways of amino acids in T. reesei and yeast Saccharomyces cerevisiae. In contrast to S. cerevisiae, however, mitochondrial rather than cytosolic biosynthesis of Asp was observed under all studied conditions. The relative anaplerotic flux to the TCA cycle was low and thus characteristic to respiratory metabolism in both strains and independent of the carbon source. Only minor differences were observed in the flux distributions of the wild type and cre1 deletion strain. Furthermore, the induction of the hydrolytic gene expression did not show altered flux distributions and did not affect the relative amino acid requirements or relative anabolic and respirative activities of the TCA cycle. CONCLUSION: High similarity between the biosynthetic pathways of amino acids in T. reesei and yeast S. cerevisiae was concluded. In vivo flux distributions confirmed that T. reesei uses primarily the respirative pathway also when growing on the repressive carbon source glucose in contrast to Saccharomyces cerevisiae, which substantially diminishes the respirative pathway flux under glucose repression. PMID- 19874613 TI - Transparency in Nigeria's public pharmaceutical sector: perceptions from policy makers. AB - BACKGROUND: Pharmaceuticals are an integral component of health care systems worldwide, thus, regulatory weaknesses in governance of the pharmaceutical system negatively impact health outcomes especially in developing countries 1. Nigeria is one of a number of countries whose pharmaceutical system has been impacted by corruption and has struggled to curtail the production and trafficking of substandard drugs. In 2001, the National Agency for Food and Drug Administration and Control (NAFDAC) underwent an organizational restructuring resulting in reforms to reduce counterfeit drugs and better regulate pharmaceuticals 2. Despite these changes, there is still room for improvement. This study assessed the perceived level of transparency and potential vulnerability to corruption that exists in four essential areas of Nigeria's pharmaceutical sector: registration, procurement, inspection (divided into inspection of ports and of establishments), and distribution. METHODS: Standardized questionnaires were adapted from the World Health Organization assessment tool and used in semi structured interviews with key stakeholders in the public and private pharmaceutical system. The responses to the questions were tallied and converted to scores on a numerical scale where lower scores suggested greater vulnerability to corruption and higher scores suggested lower vulnerability. RESULTS: The overall score for Nigeria's pharmaceutical system was 7.4 out of 10, indicating a system that is marginally vulnerable to corruption. The weakest links were the areas of drug registration and inspection of ports. Analysis of the qualitative results revealed that the perceived level of corruption did not always match the qualitative evidence. CONCLUSION: Despite the many reported reforms instituted by NAFDAC, the study findings suggest that facets of the pharmaceutical system in Nigeria remain fairly vulnerable to corruption. The most glaring deficiency seems to be the absence of conflict of interest guidelines which, if present and consistently administered, limit the promulgation of corrupt practices. Other major contributing factors are the inconsistency in documentation of procedures, lack of public availability of such documentation, and inadequacies in monitoring and evaluation. What is most critical from this study is the identification of areas that still remain permeable to corruption and, perhaps, where more appropriate checks and balances are needed from the Nigerian government and the international community. PMID- 19874612 TI - Insurance data for research in companion animals: benefits and limitations. AB - The primary aim of this article is to review the use of animal health insurance data in the scientific literature, especially in regard to morbidity or mortality in companion animals and horses. Methods and results were compared among studies on similar health conditions from different nations and years. A further objective was to critically evaluate benefits and limitations of such databases, to suggest ways to maximize their utility and to discuss the future use of animal insurance data for research purposes. Examples of studies on morbidity, mortality and survival estimates in dogs and horses, as well as neoplasia in dogs, are discussed.We conclude that insurance data can and should be used for research purposes in companion animals and horses. Insurance data have been successfully used, e.g. to quantify certain features that may have been hitherto assumed, but unmeasured. Validation of insurance databases is necessary if they are to be used in research. This must include the description of the insured population and an evaluation of the extent to which it represents the source population. Data content and accuracy must be determined over time, including the accuracy/consistency of diagnostic information. Readers must be cautioned as to limitations of the databases and, as always, critically appraise findings and synthesize information with other research. Similar findings from different study designs provide stronger evidence than a sole report. Insurance data can highlight common, expensive and severe conditions that may not be evident from teaching hospital case loads but may be significant burdens on the health of a population. PMID- 19874614 TI - Inflammatory bowel disease activity assessed by fecal calprotectin and lactoferrin: correlation with laboratory parameters, clinical, endoscopic and histological indexes. AB - BACKGROUND: Research has shown that fecal biomarkers are useful to assess the activity of inflammatory bowel disease (IBD). The aim of the study is: to evaluate the efficacy of the fecal lactoferrin and calprotectin as indicators of inflammatory activity. FINDINGS: A total of 78 patients presenting inflammatory bowel disease were evaluated. Blood tests, the Crohn's Disease Activity Index (CDAI), Mayo Disease Activity Index (MDAI), and Crohn's Disease Endoscopic Index of Severity (CDEIS) were used for the clinical and endoscopic evaluation. Two tests were performed on the fecal samples, to check the levels of calprotectin and lactoferrin. The performance of these fecal markers for detection of inflammation with reference to endoscopic and histological inflammatory activity was assessed and calculated sensitivity, specificity, accuracy.A total of 52 patient's samples whose histological evaluations showed inflammation, 49 were lactoferrin-positive, and 40 were calprotectin-positive (p = 0.000). Lactoferrin and calprotectin findings correlated with C-reactive protein in both the CD and UC groups (p = 0.006; p = 0.000), with CDAI values (p = 0.043; 0.010), CDEIS values in DC cases (p = 0,000; 0.000), and with MDAI values in UC cases (p = 0.000). CONCLUSION: Fecal lactoferrin and calprotectin are highly sensitive and specific markers for detecting intestinal inflammation. Levels of fecal calprotectin have a proportional correlation to the degree of inflammation of the intestinal mucosa. PMID- 19874615 TI - Combined intermittent hypoxia and surface muscle electrostimulation as a method to increase peripheral blood progenitor cell concentration. AB - BACKGROUND: Our goal was to determine whether short-term intermittent hypoxia exposure, at a level well tolerated by healthy humans and previously shown by our group to increase EPO and erythropoiesis, could mobilize hematopoietic stem cells (HSC) and increase their presence in peripheral circulation. METHODS: Four healthy male subjects were subjected to three different protocols: one with only a hypoxic stimulus (OH), another with a hypoxic stimulus plus muscle electrostimulation (HME) and the third with only muscle electrostimulation (OME). Intermittent hypobaric hypoxia exposure consisted of only three sessions of three hours at barometric pressure 540 hPa (equivalent to an altitude of 5000 m) for three consecutive days, whereas muscular electrostimulation was performed in two separate periods of 25 min in each session. Blood samples were obtained from an antecubital vein on three consecutive days immediately before the experiment and 24 h, 48 h, 4 days and 7 days after the last day of hypoxic exposure. RESULTS: There was a clear increase in the number of circulating CD34+ cells after combined hypobaric hypoxia and muscular electrostimulation. This response was not observed after the isolated application of the same stimuli. CONCLUSION: Our results open a new application field for hypobaric systems as a way to increase efficiency in peripheral HSC collection. PMID- 19874616 TI - Inheritance of fertility in broiler chickens. AB - BACKGROUND: The fertility of a chicken's egg is a trait which depends on both the hen that lays the egg and on her mate. It is also known that fertility of an individual changes over the laying period. METHODS: Longitudinal models including both random genetic and permanent environmental effects of both the female and her male mate were used to model the proportion of fertile eggs in a pedigree broiler population over the ages 29-54 weeks. RESULTS: Both the male and the female contribute to variation in fertility. Estimates of heritability of weekly records were typically 7% for female and 10% for male contributions to fertility. Repeatability estimates ranged from 24 to 33%, respectively. The estimated genetic variance remained almost constant for both sexes over the laying period and the genetic correlations between different ages were close to 1.0. The permanent environment components increased substantially towards the end of the analyzed period, and correlations between permanent environment effects at different ages declined with increasing age difference The heritability of mean fertility over the whole laying period was estimated at 13% for females and 17% for males. A small positive correlation between genetic effects for male and female fertility was found. CONCLUSION: Opportunities to improve fertility in broiler stocks by selection on both sexes exist and should have an impact throughout the laying period. PMID- 19874617 TI - Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen. AB - BACKGROUND: In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. RESULTS: Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. CONCLUSION: Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer. PMID- 19874618 TI - Exploring the impact of the Baby-Friendly Hospital Initiative on trends in exclusive breastfeeding. AB - BACKGROUND: The Baby-Friendly Hospital Initiative (BFHI) seeks to support breastfeeding initiation in maternity services. This study uses country-level data to examine the relationship between BFHI programming and trends in exclusive breastfeeding (EBF) in 14 developing countries. METHODS: Demographic and Health Surveys and UNICEF BFHI Reports provided EBF and BFHI data. Because country programs were initiated in different years, data points were realigned to the year that the first Baby-Friendly hospital was certified in that country. Pre-and post-implementation time periods were analyzed using fixed effects models to account for grouping of data by country, and compared to assess differences in trends. RESULTS: Statistically significant upward trends in EBF under two months and under six months, as assessed by whether fitted trends had slopes significantly different from 0, were observed only during the period following BFHI implementation, and not before. BFHI implementation was associated with average annual increases of 1.54 percentage points in the rate of EBF of infants under two months (p < 0.001) and 1.11-percentage points in the rate of EBF of infants under six months (p < 0.001); however, these rates were not statistically different from pre-BFHI trends. CONCLUSION: BFHI implementation was associated with a statistically significant annual increase in rates of EBF in the countries under study; however, small sample sizes may have contributed to the fact that results do not demonstrate a significant difference from pre-BFHI trends. Further research is needed to consider trends according to the percentages of Baby Friendly facilities, percent of all births occurring in these facilities, and continued compliance with the program. PMID- 19874619 TI - Changes in timber haul emissions in the context of shifting forest management and infrastructure. AB - BACKGROUND: Although significant amounts of carbon may be stored in harvested wood products, the extraction of that carbon from the forest generally entails combustion of fossil fuels. The transport of timber from the forest to primary milling facilities may in particular create emissions that reduce the net sequestration value of product carbon storage. However, attempts to quantify the effects of transport on the net effects of forest management typically use relatively sparse survey data to determine transportation emission factors. We developed an approach for systematically determining transport emissions using: 1) -remotely sensed maps to estimate the spatial distribution of harvests, and 2) - industry data to determine landscape-level harvest volumes as well as the location and processing totals of individual mills. These data support spatial network analysis that can produce estimates of fossil carbon released in timber transport. RESULTS: Transport-related emissions, evaluated as a fraction of transported wood carbon at 4 points in time on a landscape in western Montana (USA), rose from 0.5% in 1988 to 1.7% in 2004 as local mills closed and spatial patterns of harvest shifted due to decreased logging on federal lands. CONCLUSION: The apparent sensitivity of transport emissions to harvest and infrastructure patterns suggests that timber haul is a dynamic component of forest carbon management that bears further study both across regions and over time. The monitoring approach used here, which draws only from widely available monitoring data, could readily be adapted to provide current and historical estimates of transport emissions in a consistent way across large areas. PMID- 19874620 TI - Steps toward broad-spectrum therapeutics: discovering virulence-associated genes present in diverse human pathogens. AB - BACKGROUND: New and improved antimicrobial countermeasures are urgently needed to counteract increased resistance to existing antimicrobial treatments and to combat currently untreatable or new emerging infectious diseases. We demonstrate that computational comparative genomics, together with experimental screening, can identify potential generic (i.e., conserved across multiple pathogen species) and novel virulence-associated genes that may serve as targets for broad-spectrum countermeasures. RESULTS: Using phylogenetic profiles of protein clusters from completed microbial genome sequences, we identified seventeen protein candidates that are common to diverse human pathogens and absent or uncommon in non pathogens. Mutants of 13 of these candidates were successfully generated in Yersinia pseudotuberculosis and the potential role of the proteins in virulence was assayed in an animal model. Six candidate proteins are suggested to be involved in the virulence of Y. pseudotuberculosis, none of which have previously been implicated in the virulence of Y. pseudotuberculosis and three have no record of involvement in the virulence of any bacteria. CONCLUSION: This work demonstrates a strategy for the identification of potential virulence factors that are conserved across a number of human pathogenic bacterial species, confirming the usefulness of this tool. PMID- 19874622 TI - The accessory papillary muscle with inferior J-waves--peculiarity or hidden danger? AB - Originally described in 1953, today the so-called J-wave is the source of much controversy. As a marker of so-called "early repolarization", this variant has been regarded as a totally benign variant since the 1960's. However, since then a wealth of data have indicated that the J-wave may be a marker of a highly arrhythmogenic substrate with a resultant high risk of sudden cardiac death.In this case report a case of an accessory papillary muscle with a prominent J-wave is described. This may be the first of many possible cases where papillary muscle variants may be the cause of the J-wave. PMID- 19874621 TI - Wnt pathway reprogramming during human embryonal carcinoma differentiation and potential for therapeutic targeting. AB - BACKGROUND: Testicular germ cell tumors (TGCTs) are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC) that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES) cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency. METHODS: Human embryonal carcinoma cells were stably infected with a lentiviral construct carrying a canonical Wnt responsive reporter to assess Wnt signalling activity following induced differentiation. Cells were differentiated with all-trans retinoic acid (RA) or by targeted repression of pluripotency factor, POU5F1. A Wnt pathway real-time-PCR array was used to evaluate changes in gene expression as cells differentiated. Highlighted Wnt pathway genes were then specifically repressed using siRNA or stable shRNA and transfected EC cells were assessed for proliferation, differentiation status and levels of core pluripotency genes. RESULTS: Canonical Wnt signalling activity was low basally in undifferentiated EC cells, but substantially increased with induced differentiation. Wnt pathway gene expression levels were compared during induced differentiation and many components were altered including ligands (WNT2B), receptors (FZD5, FZD6, FZD10), secreted inhibitors (SFRP4, SFRP1), and other effectors of Wnt signalling (FRAT2, DAAM1, PITX2, Porcupine). Independent repression of FZD5, FZD7 and WNT5A using transient as well as stable methods of RNA interference (RNAi) inhibited cell growth of pluripotent NT2/D1 human EC cells, but did not appreciably induce differentiation or repress key pluripotency genes. Silencing of FZD7 gave the greatest growth suppression in all human EC cell lines tested including NT2/D1, NT2/D1-R1, Tera-1 and 833K cells. CONCLUSION: During induced differentiation of human EC cells, the Wnt signalling pathway is reprogrammed and canonical Wnt signalling induced. Specific species regulating non-canonical Wnt signalling conferred growth inhibition when targeted for repression in these EC cells. Notably, FZD7 repression significantly inhibited growth of human EC cells and is a promising therapeutic target for TGCTs. PMID- 19874623 TI - Team climate and quality of care in primary health care: a review of studies using the Team Climate Inventory in the United Kingdom. AB - BACKGROUND: Attributes of teams could affect the quality of care delivered in primary care. The aim of this study was to systematically review studies conducted within the UK NHS primary care that have measured team climate using the Team Climate Inventory (TCI), and to describe, if reported, the relationship between the TCI and measures of quality of care. FINDINGS: The databases MEDLINE, EMBASE, and CINAHL were searched. The reference lists of included article were checked and one relevant journal was hand-searched. Eight papers were included. Three studies used a random sample; the remaining five used convenience or purposive samples. Six studies were cross sectional surveys, whilst two were before and after studies. Four studies examined the relationship between team climate and quality of care. Only one study found a positive association between team climate and higher quality care in patients with diabetes, positive patient satisfaction and self-reported effectiveness. CONCLUSION: While the TCI has been used to measure team attributes in primary care settings in the UK it is difficult to generalise from these data. A small number of studies reported higher TCI scores being associated with only certain aspects of quality of care; reasons for the pattern of association are unclear. There are a number of methodological challenges to conducting such studies in routine service settings. Further research is needed in order to understand how to measure team functioning in relation to quality of care. PMID- 19874624 TI - Expression of nodal signalling components in cycling human endometrium and in endometrial cancer. AB - BACKGROUND: The human endometrium is unique in its capacity to remodel constantly throughout adult reproductive life. Although the processes of tissue damage and breakdown in the endometrium have been well studied, little is known of how endometrial regeneration is achieved after menstruation. Nodal, a member of the transforming growth factor-beta superfamily, regulates the processes of pattern formation and differentiation that occur during early embryo development. METHODS: In this study, the expression of Nodal, Cripto (co-receptor) and Lefty A (antagonist) was examined by RT-PCR and immunohistochemistry across the menstrual cycle and in endometrial carcinomas. RESULTS: Nodal and Cripto were found to be expressed at high levels in both stromal and epithelial cells during the proliferative phase of the menstrual cycle. Although immunoreactivity for both proteins in surface and glandular epithelium was maintained at relatively steady state levels across the cycle, their expression was significantly decreased within the stromal compartment by the mid-secretory phase. Lefty expression, as has previously been reported, was primarily restricted to glandular epithelium and surrounding stroma during the late secretory and menstrual phases. In line with recent studies that have shown that Nodal pathway activity is upregulated in many human cancers, we found that Nodal and Cripto immunoreactivity increased dramatically in the transition from histologic Grade 1 to histologic Grades 2 and 3 endometrial carcinomas. Strikingly, Lefty expression was low or absent in all cancer tissues. CONCLUSION: The expression of Nodal in normal and malignant endometrial cells that lack Lefty strongly supports an important role for this embryonic morphogen in the tissue remodelling events that occur across the menstrual cycle and in tumourogenesis. PMID- 19874625 TI - TinkerCell: modular CAD tool for synthetic biology. AB - BACKGROUND: Synthetic biology brings together concepts and techniques from engineering and biology. In this field, computer-aided design (CAD) is necessary in order to bridge the gap between computational modeling and biological data. Using a CAD application, it would be possible to construct models using available biological "parts" and directly generate the DNA sequence that represents the model, thus increasing the efficiency of design and construction of synthetic networks. RESULTS: An application named TinkerCell has been developed in order to serve as a CAD tool for synthetic biology. TinkerCell is a visual modeling tool that supports a hierarchy of biological parts. Each part in this hierarchy consists of a set of attributes that define the part, such as sequence or rate constants. Models that are constructed using these parts can be analyzed using various third-party C and Python programs that are hosted by TinkerCell via an extensive C and Python application programming interface (API). TinkerCell supports the notion of a module, which are networks with interfaces. Such modules can be connected to each other, forming larger modular networks. TinkerCell is a free and open-source project under the Berkeley Software Distribution license. Downloads, documentation, and tutorials are available at http://www.tinkercell.com. CONCLUSION: An ideal CAD application for engineering biological systems would provide features such as: building and simulating networks, analyzing robustness of networks, and searching databases for components that meet the design criteria. At the current state of synthetic biology, there are no established methods for measuring robustness or identifying components that fit a design. The same is true for databases of biological parts. TinkerCell's flexible modeling framework allows it to cope with changes in the field. Such changes may involve the way parts are characterized or the way synthetic networks are modeled and analyzed computationally. TinkerCell can readily accept third-party algorithms, allowing it to serve as a platform for testing different methods relevant to synthetic biology. PMID- 19874626 TI - Assessment of oral self-care in patients with periodontitis: a pilot study in a dental school clinic in Japan. AB - BACKGROUND: Oral hygiene education is central to every stage of periodontal treatment. Successful management of periodontal disease depends on the patient's capacity for oral self-care. In the present study, the oral self-care and perceptions of patients attending a dental school clinic in Japan were assessed using a short questionnaire referring to existing oral health models. METHODS: A cross-sectional study design was used. The study population consisted of sixty five patients (age range 23-77) with chronic periodontitis. The pre-tested 19 item questionnaire comprised 3 domains; 1) oral hygiene, 2) dietary habits and 3) perception of oral condition. The questionnaire was used as a part of the comprehensive assessment. RESULTS: Analyses of the assessment data revealed no major problems with the respondents' perceived oral hygiene habits, although their actual plaque control levels were not entirely adequate. Most of the respondents acknowledged the importance of prevention of dental caries and periodontal diseases, but less than one third of them were regular users of the dental care system. Twenty-five percent of the respondents were considered to be reluctant to change their daily routines, and 29% had doubts about the impact of their own actions on oral health. Analyzing the relationships between patient responses and oral hygiene status, factors like 'frequency of tooth brushing', 'approximal cleaning', 'dental check-up' and 'compliance with self-care advice' showed statistically significant associations (P < 0.05) with the plaque scores. CONCLUSION: The clinical utilization of the present questionnaire facilitates the inclusion of multiple aspects of patient information, before initiation of periodontal treatment. The significant associations that were found between some of the self-care behaviors and oral hygiene levels document the important role of patient-centered oral health assessment in periodontal care. PMID- 19874627 TI - Influenza H5N1 virus infection of polarized human alveolar epithelial cells and lung microvascular endothelial cells. AB - BACKGROUND: Highly pathogenic avian influenza (HPAI) H5N1 virus is entrenched in poultry in Asia and Africa and continues to infect humans zoonotically causing acute respiratory disease syndrome and death. There is evidence that the virus may sometimes spread beyond respiratory tract to cause disseminated infection. The primary target cell for HPAI H5N1 virus in human lung is the alveolar epithelial cell. Alveolar epithelium and its adjacent lung microvascular endothelium form host barriers to the initiation of infection and dissemination of influenza H5N1 infection in humans. These are polarized cells and the polarity of influenza virus entry and egress as well as the secretion of cytokines and chemokines from the virus infected cells are likely to be central to the pathogenesis of human H5N1 disease. AIM: To study influenza A (H5N1) virus replication and host innate immune responses in polarized primary human alveolar epithelial cells and lung microvascular endothelial cells and its relevance to the pathogenesis of human H5N1 disease. METHODS: We use an in vitro model of polarized primary human alveolar epithelial cells and lung microvascular endothelial cells grown in transwell culture inserts to compare infection with influenza A subtype H1N1 and H5N1 viruses via the apical or basolateral surfaces. RESULTS: We demonstrate that both influenza H1N1 and H5N1 viruses efficiently infect alveolar epithelial cells from both apical and basolateral surface of the epithelium but release of newly formed virus is mainly from the apical side of the epithelium. In contrast, influenza H5N1 virus, but not H1N1 virus, efficiently infected polarized microvascular endothelial cells from both apical and basolateral aspects. This provides a mechanistic explanation for how H5N1 virus may infect the lung from systemic circulation. Epidemiological evidence has implicated ingestion of virus-contaminated foods as the source of infection in some instances and our data suggests that viremia, secondary to, for example, gastro-intestinal infection, can potentially lead to infection of the lung. HPAI H5N1 virus was a more potent inducer of cytokines (e.g. IP-10, RANTES, IL-6) in comparison to H1N1 virus in alveolar epithelial cells, and these virus-induced chemokines were secreted onto both the apical and basolateral aspects of the polarized alveolar epithelium. CONCLUSION: The predilection of viruses for different routes of entry and egress from the infected cell is important in understanding the pathogenesis of influenza H5N1 infection and may help unravel the pathogenesis of human H5N1 disease. PMID- 19874628 TI - Developing and pre-testing a decision board to facilitate informed choice about delivery approach in uncomplicated pregnancy. AB - BACKGROUND: The rate of caesarean sections is increasing worldwide, yet medical literature informing women with uncomplicated pregnancies about relative risks and benefits of elective caesarean section (CS) compared with vaginal delivery (VD) remains scarce. A decision board may address this gap, providing systematic evidence-based information so that patients can more fully understand their treatment options. The objective of our study was to design and pre-test a decision board to guide clinical discussions and enhance informed decision-making related to delivery approach (CS or VD) in uncomplicated pregnancy. METHODS: Development of the decision board involved two preliminary studies to determine women's preferred mode of risk presentation and a systematic literature review for the most comprehensive presentation of medical risks at the time (VD and CS). Forty women were recruited to pre-test the tool. Eligible subjects were of childbearing age (18-40 years) but were not pregnant in order to avoid raising the expectation among pregnant women that CS was a universally available birth option. Women selected their preferred delivery approach and completed the Decisional Conflict Scale to measure decisional uncertainty before and after reviewing the decision board. They also answered open-ended questions reflecting what they had learned, whether or not the information had helped them to choose between birth methods, and additional information that should be included. Descriptive statistics were used to analyse sample characteristics and women's choice of delivery approach pre/post decision board. Change in decisional conflict was measured using Wilcoxon's sign rank test for each of the three subscales. RESULTS: The majority of women reported that they had learned something new (n = 37, 92%) and that the tool had helped them make a hypothetical choice between delivery approaches (n = 34, 85%). Women wanted more information about neonatal risks and personal experiences. Decisional uncertainty decreased (p < 0.001) and perceived effectiveness of decisions increased (p < 0.001) post intervention. CONCLUSION: Non-pregnant women of childbearing age were positive about the decision board and stated their hypothetical delivery choices were informed by risk presentation, but wanted additional information about benefits and experiences. This study represents a preliminary but integral step towards ensuring women considering delivery approaches in uncomplicated pregnancies are fully informed. PMID- 19874629 TI - Protein kinase C promotes restoration of calcium homeostasis to platelet activating factor-stimulated human neutrophils by inhibition of phospholipase C. AB - BACKGROUND: The role of protein kinase C (PKC) in regulating the activity of phospholipase C (PLC) in neutrophils activated with the chemoattractant, platelet activating factor (PAF, 20 and 200 nM), was probed in the current study using the selective PKC inhibitors, GF10903X (0.5 - 1 muM) and staurosporine (400 nM). METHODS: Alterations in cytosolic Ca2+, Ca2+ influx, inositol triphosphate (IP3), and leukotriene B4 production were measured using spectrofluorimetric, radiometric and competitive binding radioreceptor and immunoassay procedures, respectively. RESULTS: Activation of the cells with PAF was accompanied by an abrupt increase in cytosolic Ca2+ followed by a gradual decline towards basal levels. Pretreatment of neutrophils with the PKC inhibitors significantly increased IP3 production with associated enhanced Ca2+ release from storage vesicles, prolongation of the peak cytosolic Ca2+ transients, delayed clearance and exaggerated reuptake of the cation, and markedly increased synthesis of LTB4. The alterations in Ca2+ fluxes observed with the PKC inhibitors were significantly attenuated by U73122, a PLC inhibitor, as well as by cyclic AMP mediated upregulation of the Ca2+-resequestering endomembrane ATPase.Taken together, these observations are compatible with a mechanism whereby PKC negatively modulates the activity of PLC, with consequent suppression of IP3 production and down-regulation of Ca2+ mediated pro-inflammatory responses of PAF activated neutrophils. CONCLUSION: Although generally considered to initiate and/or amplify intracellular signalling cascades which activate and sustain the pro-inflammatory activities of neutrophils and other cell types, the findings of the current study have identified a potentially important physiological, anti inflammatory function for PKC, at least in neutrophils. PMID- 19874630 TI - Validation of reference genes for quantitative expression analysis by real-time RT-PCR in Saccharomyces cerevisiae. AB - BACKGROUND: Real-time RT-PCR is the recommended method for quantitative gene expression analysis. A compulsory step is the selection of good reference genes for normalization. A few genes often referred to as HouseKeeping Genes (HSK), such as ACT1, RDN18 or PDA1 are among the most commonly used, as their expression is assumed to remain unchanged over a wide range of conditions. Since this assumption is very unlikely, a geometric averaging of multiple, carefully selected internal control genes is now strongly recommended for normalization to avoid this problem of expression variation of single reference genes. The aim of this work was to search for a set of reference genes for reliable gene expression analysis in Saccharomyces cerevisiae. RESULTS: From public microarray datasets, we selected potential reference genes whose expression remained apparently invariable during long-term growth on glucose. Using the algorithm geNorm, ALG9, TAF10, TFC1 and UBC6 turned out to be genes whose expression remained stable, independent of the growth conditions and the strain backgrounds tested in this study. We then showed that the geometric averaging of any subset of three genes among the six most stable genes resulted in very similar normalized data, which contrasted with inconsistent results among various biological samples when the normalization was performed with ACT1. Normalization with multiple selected genes was therefore applied to transcriptional analysis of genes involved in glycogen metabolism. We determined an induction ratio of 100-fold for GPH1 and 20-fold for GSY2 between the exponential phase and the diauxic shift on glucose. There was no induction of these two genes at this transition phase on galactose, although in both cases, the kinetics of glycogen accumulation was similar. In contrast, SGA1 expression was independent of the carbon source and increased by 3-fold in stationary phase. CONCLUSION: In this work, we provided a set of genes that are suitable reference genes for quantitative gene expression analysis by real-time RT-PCR in yeast biological samples covering a large panel of physiological states. In contrast, we invalidated and discourage the use of ACT1 as well as other commonly used reference genes (PDA1, TDH3, RDN18, etc) as internal controls for quantitative gene expression analysis in yeast. PMID- 19874631 TI - Accurate molecular classification of cancer using simple rules. AB - BACKGROUND: One intractable problem with using microarray data analysis for cancer classification is how to reduce the extremely high-dimensionality gene feature data to remove the effects of noise. Feature selection is often used to address this problem by selecting informative genes from among thousands or tens of thousands of genes. However, most of the existing methods of microarray-based cancer classification utilize too many genes to achieve accurate classification, which often hampers the interpretability of the models. For a better understanding of the classification results, it is desirable to develop simpler rule-based models with as few marker genes as possible. METHODS: We screened a small number of informative single genes and gene pairs on the basis of their depended degrees proposed in rough sets. Applying the decision rules induced by the selected genes or gene pairs, we constructed cancer classifiers. We tested the efficacy of the classifiers by leave-one-out cross-validation (LOOCV) of training sets and classification of independent test sets. RESULTS: We applied our methods to five cancerous gene expression datasets: leukemia (acute lymphoblastic leukemia [ALL] vs. acute myeloid leukemia [AML]), lung cancer, prostate cancer, breast cancer, and leukemia (ALL vs. mixed-lineage leukemia [MLL] vs. AML). Accurate classification outcomes were obtained by utilizing just one or two genes. Some genes that correlated closely with the pathogenesis of relevant cancers were identified. In terms of both classification performance and algorithm simplicity, our approach outperformed or at least matched existing methods. CONCLUSION: In cancerous gene expression datasets, a small number of genes, even one or two if selected correctly, is capable of achieving an ideal cancer classification effect. This finding also means that very simple rules may perform well for cancerous class prediction. PMID- 19874632 TI - Comparison of the effects of a liquid yogurt and chocolate bars on satiety: a multidimensional approach. AB - In the context of epidemic obesity, satiety is an important target for nutritional interventions. Using a multidimensional approach, we compared the effect on satiety of two food products frequently consumed in France by young adults as a small mid-afternoon meal called the 'gouter'. Participants were eighteen healthy young males (aged 20.8 (sd 1.8) years) of normal body weight (BMI 21.7 (sd 1.7) kg/m2) used to eating four times per d including a 'gouter'. On two occasions, under laboratory conditions, the time-blinded participants consumed a fixed energy lunch (2.8 MJ) and, 240 min later, either a liquid yogurt or chocolate bars matched for energy (1.2 MJ) and weight (366 g). Then, satiety was assessed by: (1) ratings of hunger, appetite, desire to eat and fullness at 20 min intervals (perception), (2) the delay until the subject requested his dinner meal (duration) and (3) energy intake at this meal (consumption). Results showed that satiety was perceived higher after liquid yogurt than chocolate bars over the 60 min preceding the next meal, as evidenced by hunger (P < 0.005), appetite, (P < 0.005), desire to eat (P < 0.04) and fullness (P < 0.05) ratings. However, its duration was similar between liquid yogurt and chocolate bars (165 (se 8) and 174 (se 7) min respectively) and this difference was not followed by reduced intake at dinner. In conclusion, this approach of satiety revealed that a liquid yogurt induced a lower subjective motivation to eat than chocolate bars during the hour preceding the spontaneous onset of a meal, without affecting subsequent food intake. PMID- 19874633 TI - Plasma alkylresorcinol metabolites as potential biomarkers of whole-grain wheat and rye cereal fibre intakes in women. AB - It has been demonstrated that intact plasma alkylresorcinols (AR) and urinary AR metabolites could be used as biomarkers of whole-grain intake. Thereafter, we developed the method for the plasma AR metabolites, which is more convenient and requires less sample pretreatment than the analysis of intact plasma AR. The aim of the present study is to evaluate whether AR metabolites measured in plasma, in the same population, could also be considered as useful biomarkers of cereal fibre. Fifty-six women were recruited in a cross-sectional and observational study. Dietary intake (5-d record) and plasma AR metabolites (3,5 dihydroxybenzoic acid, DHBA; 3-(3,5-dihydroxyphenyl)-1-propanoic acid, DHPPA) were measured. The relationship between plasma AR metabolites and cereal fibre intake was examined using partial correlation and stepwise regression. Cereal fibre intake correlated significantly with plasma DHBA (r 0.411; P = 0.002) and DHPPA (r 0.463; P = 0.000) even after adjustment for BMI and age. Thus, plasma AR metabolites correlate with cereal fibre intake as noted with plasma intact AR and urinary AR metabolites. We observed that plasma DHPPA was the independent predictor of cereal fibre intake, explaining 18 % of the variance (adjusted r(2) 0.176; P = 0.002). In epidemiological screening, it might be easier to obtain and to collect plasma than urine samples. In addition, the plasma AR metabolites half life seems longer than those of intact plasma AR, and their measurements are more convenient, and faster. Thus, sum of plasma AR metabolites and more specifically plasma DHPPA seems to be good and specific biomarkers of cereal fibre intake. PMID- 19874634 TI - Effects of a breakfast yoghurt, with additional total whey protein or caseinomacropeptide-depleted alpha-lactalbumin-enriched whey protein, on diet induced thermogenesis and appetite suppression. AB - Previous studies have shown effects of high-protein diets, especially whey protein, on energy expenditure and satiety, yet a possible distinction between the effects of whey or alpha-lactalbumin has not been made. The present study assessed the effects of the addition of total whey protein (whey) or caseinomacropeptide-depleted alpha-lactalbumin-enriched whey protein (alpha-lac) to a breakfast yoghurt drink on energy expenditure and appetite suppression in human subjects. A total of eighteen females and seventeen males (aged 20.9 (sd 1.9) years; BMI 23.0 (sd 2.1) kg/m2) participated in an experiment with a randomised, three-arm, cross-over design where diet-induced energy expenditure, respiratory quotient and satiety were measured. Breakfasts were isoenergetic and subject-specific: a normal-protein (NP) breakfast consisting of whole milk (15, 47 and 38 % energy from protein, carbohydrate and fat, respectively), a high protein (HP) breakfast with additional whey or a HP breakfast containing alpha lac (41, 47 and 12 % energy from protein, carbohydrate and fat, respectively). Resting energy expenditure did not differ between the three conditions. HP breakfasts (area under the curve: whey, 217.1 (se 10.0) kJ x 4 h; alpha-lac, 234.3 (se 11.6) kJ x 4 h; P < 0.05) increased diet-induced thermogenesis more compared with a NP yoghurt at breakfast (179.7 (se 10.9) kJ x 4 h; P < 0.05). Hunger and desire to eat were significantly more suppressed after alpha-lac (hunger, - 6627 (se 823); desire to eat, - 6750 (se 805) mm visual analogue scale (VAS) x 4 h; P < 0.05) than after the whey HP breakfast (hunger, - 5448 (se 913); desire to eat, - 5070 (se 873) mm VAS x 4 h; P < 0.05). After the HP breakfasts, a positive protein balance occurred (alpha-lac, 0.35 (sd 0.18) MJ/4 h; whey, 0.37 (sd 0.20) MJ/4 h; P < 0.001); after the NP breakfast a positive fat balance occurred (1.03 (sd 0.29) MJ/4 h; P < 0.001). In conclusion, consumption of a breakfast yoghurt drink with added whey or alpha-lac increased energy expenditure, protein balance and decreased fat balance compared with a NP breakfast. The alpha-lac-enriched yoghurt drink suppressed hunger and the desire to eat more than the whey-enriched yoghurt drink. PMID- 19874635 TI - Reduced circulating antioxidant defences are associated with airway hyper responsiveness, poor control and severe disease pattern in asthma. AB - Dietary antioxidants are important in protecting against oxidative stress. We have previously demonstrated that circulating dietary antioxidant levels are reduced in asthma. The present study examined the variation in dietary antioxidant levels in asthma, according to airway responsiveness, asthma control and clinical asthma pattern. Peripheral blood was collected from forty-one subjects with stable, persistent asthma. Airway responsiveness was assessed by hypertonic saline challenge. Asthma control was assessed using the Asthma Control Questionnaire. Clinical asthma pattern was determined using Global Initiative for Asthma (GINA) criteria. Whole-blood carotenoids (beta-carotene, lycopene, alpha carotene, beta-cryptoxanthin, lutein/zeaxanthin) and tocopherols (alpha-, delta-, gamma-tocopherol) were measured by HPLC. Plasma antioxidant potential (AOP) was determined by colorimetric assay (OxisResearch, Portland, OR, USA). Asthmatic subjects with airway hyper-responsiveness (AHR) had reduced levels of beta carotene and alpha-tocopherol compared with those without AHR. Subjects with uncontrolled asthma had low levels of AOP compared with those with controlled or partly controlled asthma. Subjects with a severe persistent clinical asthma pattern had reduced levels of alpha-tocopherol compared with those with a mild to moderate asthma pattern. We conclude that asthmatic subjects with AHR, uncontrolled asthma and a severe asthma pattern have impaired antioxidant defences and are thus most susceptible to the damaging effects of oxidative stress. This highlights the potential role for antioxidant supplementation in these subjects. PMID- 19874636 TI - Effect of almond-enriched high-monounsaturated fat diet on selected markers of inflammation: a randomised, controlled, crossover study. AB - Frequent consumption of nuts lowers the risk of CHD. While lowering blood lipids is one of the mechanisms for cardioprotection, the present study sought to determine whether monounsaturated fat-rich almonds also influence other CHD risk factors such as inflammation and haemostasis. This was a randomised, controlled, crossover feeding study with twenty-five healthy adults (eleven men; fourteen women), age 22-53 years. Following a 2 week run-in phase (34 % energy from fat), subjects were assigned in random order to three diets for 4 weeks each: a heart healthy control diet with no nuts ( < 30 % energy from fat), low-almond diet and high-almond diet (10 % or 20 % isoenergetic replacement of control diet with almonds, respectively). Serum E-selectin was significantly lower on the high almond diet compared with the control diet. E-selectin decreased as the percentage of energy from almonds increased (P < 0.0001). C-reactive protein (CRP) was lower in both the almond diets compared with the control diet. A clear dose response was not observed for either E-selectin or CRP. There was no effect of diet on IL-6 or fibrinogen. Tissue plasminogen activator antigen was significantly lower on the control and high-almond diets compared with the low almond diet, although the values were within normal range. In conclusion, consumption of almonds influenced a few but not all of the markers of inflammation and haemostasis. A clear dose response was not observed for any of the markers studied. PMID- 19874637 TI - Rates of Stenotrophomonas maltophilia colonization and infection in relation to antibiotic cycling protocols. AB - This study evaluated whether antibiotic cycling programmes using broad-spectrum agents including carbapenems were associated with increased rates of colonization or infection by Stenotrophomonas maltophilia. Retrospective analyses of colonization or infection by S. maltophilia from 1992 to 2002 were conducted using University of Virginia Hospital clinical microbiology records of patients with any culture positive for S. maltophilia and hospital epidemiology records of nosocomial S. maltophilia infections. Incidence rates were calculated and compared for cycling and non-cycling periods. No significant differences were found in incidence rates of S. maltophilia isolates between cycling and non cycling periods, but there was a significant secular increase in the hospital wide rate of infections caused by S. maltophilia (P=0.01728). Antibiotic cycling protocols were not associated with a significantly increased rate of colonization of S. maltophilia as determined by the frequency of patients having at least one positive routine clinical culture in this hospital. PMID- 19874638 TI - Effect of nasolacrimal duct obstruction on nasal mucociliary transport. AB - BACKGROUND: Most patients with nasolacrimal duct obstruction have dry, crusty nasal mucosa. Mucociliary clearance is modulated by the amount and biochemical composition of nasal mucus. Nasolacrimal duct obstruction disturbs the drainage of tears into the nasal cavity. OBJECTIVE: We examined the effect of nasolacrimal duct obstruction on the mucociliary transport of nasal mucosa, by comparing saccharine test results for epiphora patients versus healthy volunteers. STUDY DESIGN: Prospective, randomised, clinical trial. METHODS: Eight patients with bilateral epiphora and 10 patients with unilateral epiphora were included in the study group. Complete nasolacrimal duct obstruction was demonstrated by studying irrigation of the nasolacrimal system, and by fluorescein dye study. The control group comprised 20 healthy volunteers. Mucociliary transport was assessed by the saccharine test in both the study and control groups. The saccharine transit times of 26 impaired nasal cavities were compared with those of 20 healthy nasal cavities of controls. Also, the saccharine transit times of the healthy nasal cavities of the 10 patients with unilateral epiphora were compared with those of their diseased sides, and also with those of healthy volunteers. RESULTS: The saccharine transit times of the epiphora patients were statistically significantly greater than those of the control group. Also, there was a statistically significant difference in saccharine transit times, comparing the healthy and impaired nasal cavities of patients with unilateral epiphora. CONCLUSION: Nasolacrimal duct obstruction has a negative effect on nasal mucociliary clearance. This may be related to changes in the amount and biochemical composition of nasal mucus. PMID- 19874639 TI - Preschoolers' extension of novel words to animals and artifacts. AB - We examined whether preschoolers' ontological knowledge would influence lexical extension. In Experiment 1, four-year-olds were presented with a novel label for either an object with eyes described as an animal, or the same object without eyes described as a tool. In the animal condition, children extended the label to similar-shaped objects, whereas in the tool condition, children extended the label to similar-function objects. In Experiment 2, when four-year-olds were presented with objects with eyes described as tools, they extended the label on the basis of shared function. These experiments suggest that preschoolers' conceptual knowledge guides their lexical extension. PMID- 19874640 TI - Determining that a label is kind-referring: factors that influence children's and adults' novel word extensions. AB - The present studies examined factors that influence children's and adults' interpretation of a novel word. Four factors are hypothesized to emphasize that a label refers to a richly structured category (also known as a 'kind'): generic language, internal property attributions, familiar kind labels and absence of a target photograph. In Study 1, for college students (N=125), internal property attributions resulted in more taxonomic and fewer shape responses. In Study 2, for four-year-olds (N=126), the presence of generic language and familiar kind labels resulted in more taxonomic choices. Further, the presence of familiar kind labels resulted in fewer shape choices. The results suggest that, when learning new words, children and adults are sensitive to factors that imply kind reference. PMID- 19874641 TI - Predictors of early precocious talking: a prospective population study. AB - This study examines potential predictors of 'precocious talking' (expressive language >=90th percentile) at one and two years of age, and of 'stability' in precocious talking across both time periods, drawing on data from a prospective community cohort comprising over 1,800 children. Logistic regression was used to examine the relationship between precocious talking and the following potential predictors: gender, birth order, birth weight, non-English speaking background, socioeconomic status, maternal age, maternal mental health scores, and vocabulary and educational attainment of parents. The strongest predictors of precocity (being female and having a younger mother) warrant further exploration. Overall, however, it appears that precocity in early vocabulary development is not strongly influenced by the variables examined, which together explained just 2.6% and 1% of the variation at 1;0 and 2;0 respectively. PMID- 19874642 TI - New Zealand's Primary Health Care Strategy: early effects of the new financing and payment system for general practice and future challenges. AB - Since 2001, implementation of a New Zealand's Primary Health Care Strategy (the Strategy) has led to an increase in the proportion of primary health care services which are publicly funded, the development of 82 primary health organisations (PHOs) to oversee primary health care services and universal public capitation funding of PHOs. This approach has replaced the previous system of fee for service targeted public subsidies paid to individual general practitioners (GPs). Patient copayments, although at a reduced level but still set by individual practitioners, have remained a core feature of the system. This paper focuses on the implementation and impact of key policy changes over the first five years of the Strategy. Although patient copayments have fallen and consultation rates have increased, the new funding and payment system has raised a number of unresolved issues - whether to retain the new universal funding system or revert to the former targeted approach; how to achieve the potential gains from capitation when GPs continue to receive their income from a variety of sources and in a variety of different ways; and how to manage the potential for 'cream skimming'. Recent improvements in access may, in time, improve health status and reduce inequalities in health, but there is no guarantee that a universal system will necessarily improve average health or reduce inequalities. Much depends on the services being delivered and the populations that are benefiting most - something New Zealand needs better evidence on before determining future policy directions in primary health care. PMID- 19874643 TI - What factors influence seniors' desire for choice among health insurance options? Survey results on the Medicare prescription drug benefit. AB - Questions about the design of the new US Medicare prescription drug benefit were raised even before its passage, where one of the most heated issues has been the number of plans offered to beneficiaries. Whether beneficiaries believe that there should be extensive or limited choice is still an open question. To study this issue, we analyzed data from the Kaiser Family Foundation/Harvard School of Public Health Survey, which included 718 individuals aged 65 years and above. The survey asked these older adults (i) whether they prefer having dozens of plans or for Medicare to offer a restricted number of plans and (ii) whether they think there are too many, too few or the right amount of plans. Our findings show that the majority of beneficiaries (69%) preferred that Medicare offer a limited number of options while only 29% wanted to see dozens of plans on the market. We also examine the effect of education level, income, political affiliation, race and health status on the desire for more or fewer plans. One surprising finding is that seniors with higher education appear to prefer fewer, not more, plan choices. Overall, our results question the merit of offering so many prescription drugs plan choices to Medicare beneficiaries. PMID- 19874644 TI - Changes in white muscle transcriptome induced by dietary energy levels in two lines of rainbow trout (Oncorhynchus mykiss) selected for muscle fat content. AB - Energy intake and genetic background are major determinants of muscle fat content in most animals, including man. We combined genetic selection and dietary energy supply to study the metabolic pathways involved in genetic and nutritional control of fat deposition in the muscle of rainbow trout (Oncorhynchus mykiss). Two experimental lines of rainbow trout, selected for lean (L) or fat (F) muscle, were fed with diets containing either 10 or 23 % lipids from the first feeding, up to 6 months. At the end of the trial, trout exhibited very different values of muscle fat content (from 4.2 to 10.1 % wet weight). Using microarrays made from a rainbow trout multi-tissue cDNA library, we analysed the molecular changes occurring in the muscle of the two lines when fed the low-energy or high-energy diet. The results from microarray analysis revealed that eleven metabolism related genes were differentially expressed according to the diet while selection resulted in expression change for twenty-six genes. The most striking observation was the increased level of transcripts encoding the VLDL receptor and fatty acid translocase/CD36 following both the high-fat diet and upward selection for muscle fat content, suggesting that these two genes are relevant molecular markers of fat deposition in the white muscle of rainbow trout. PMID- 19874645 TI - A comparison of the validity of gas chromatography- mass spectrometry and liquid chromatography- tandem mass spectrometry analysis of urine samples for morphine, codeine, 6-acetylmorphine, and benzoylecgonine. AB - On November 25, 2008, the U.S. Department of Health and Human Services posted a final notice in the Federal Register authorizing the use of liquid chromatography tandem mass spectrometry (LC-MS-MS) and other technologies in federally regulated workplace drug testing (WPDT) programs. These rules are expected to become effective in May 2010. To support this change, it is essential to explicitly demonstrate that LC-MS-MS as a technology can produce results at least as valid as gas chromatography-mass spectrometry (GC-MS), the long-accepted standard in confirmatory analytical technologies for drugs of abuse and currently the only confirmatory method allowed for use in support of federally regulated WPDT programs. A series of manufactured control urine samples (n = 10 for each analyte) containing benzoylecgonine, morphine, codeine, and 6-acetylmorphine at concentrations ranging from 10% to 2000% of federal cutoffs were analyzed with replication by five federally regulated laboratories using GC-MS (five replicate analyses per lab) and at RTI International using LC-MS-MS (10 replicate analyses). Interference samples as described in the National Laboratory Certification Program 2009 Manual were also analyzed by both GC-MS and LC-MS-MS. In addition, matrix effects were assessed for LC-MS-MS, and both analytical technologies were used to analyze previously confirmed urine specimens of WPDT origin. Results indicated that LC-MS-MS analysis produced results at least as precise, accurate, and specific as GC-MS for the analytes investigated in this study. Matrix effects, while evident, could be controlled by the use of matrix matched controls and calibrators with deuterated internal standards. LC-MS-MS data parameters, such as retention time and product ion ratios, were highly reproducible. PMID- 19874646 TI - Determination of naloxone and nornaloxone (noroxymorphone) by high-performance liquid chromatography-electrospray ionization- tandem mass spectrometry. AB - A highly sensitive method was developed to measure naloxone and its metabolite nornaloxone in human plasma, urine, and human liver microsomes (HLM). Naltrexone d(3) and oxymorphone-d(3) were used as respective internal standards. Solid-phase extraction, using mixed mode extraction columns and 0.1 M phosphate buffer (pH 5.9), was combined with high-performance liquid chromatography interfaced by electrospray ionization to tandem mass spectrometry. The calibration range in plasma was 0.025 to 2 ng/mL for naloxone and 0.5 to 20 ng/mL for nornaloxone. It was 10 to 2000 ng/mL in urine and 0.5 to 20 ng/mL in HLM for both. Enzymatic hydrolysis of urine was optimized for 4 h at 40 degrees C. Intra- and interrun accuracy was within 15% of target; precision within 13.4% for all matrices. The mean recoveries were 69.2% for naloxone and 32.0% for nornaloxone. Analytes were stable in plasma and urine for up to 24 h at room temperature and in plasma after three freeze-thaw cycles. In human subjects receiving 16 mg buprenorphine and 4 mg naloxone, naloxone was detected for up to 2 h in all three subjects and up to 4 h in one subject. Mean AUC(0-24) was 0.303 +/- 0.145 ng/mL.h; mean C(max) was 0.139 +/- 0.062 ng/mL; and T(max) was 0.5 h. In 24-h urine samples, about 55% of the daily dose was excreted in either conjugated or unconjugated forms of naloxone and nornaloxone in urine. When cDNA-expressed P450s were incubated with 20 ng of naloxone, nornaloxone formation was detected for P450s 2C18, 2C19, and 3A4. Naloxone utilization exceeded nornaloxone formation for 2C19 and 3A4, indicating they may produce products other than nornaloxone. These results demonstrate a new method suitable for both in vivo and in vitro metabolism and pharmacokinetic studies of naloxone. PMID- 19874647 TI - Potential biomarkers of smoked fentanyl utilizing pyrolysis gas chromatography mass spectrometry. AB - Fentanyl is a potent opioid analgesic that is increasingly becoming a choice drug of abuse. Fentanyl transdermal patches (FTPs) are easily obtained and consumed by smoking the reservoir gel and/or the whole patch. This allows for an increased bioavailability when inhaled. A method using analytical pyrolysis was developed to identify possible biomarkers associated with smoked fentanyl and FTPs. Pyrolysis was carried out under anaerobic and aerobic conditions using helium and air coupled to a gas chromatograph-mass spectrometer. The presence of a trap enhanced recovery and afforded a positive identification of pyrolytic products. Anaerobic and aerobic pyrolysis of fentanyl and FTPs consistently yielded propionanilide as the major pyrolytic product along with pyridine and previously reported metabolites (norfentanyl and despropionyl fentanyl). Analysis of fentanyl resulted in chlorine-containing compounds, presumably formed from the HCl salt of fentanyl. Analysis of FTPs showed significant polymeric and hydrocarbon compounds and products likely derived from the gel matrix. Fentanyl in the FTPs was in the citrate salt form; therefore, the chlorine-containing pyrolytic products obtained with the neat drug were not observed. Based on this application, it may be possible to identify what salt form of the drug was smoked based on pyrolytic products and to target distinguishing metabolic products for future research. PMID- 19874648 TI - Oxycodone-related fatalities in the west of Scotland. AB - The intent of this study was to review fatalities involving oxycodone in the west of Scotland using a liquid chromatography-electrospray ionization-tandem mass spectrometry method developed for the determination of oxycodone and N- and O demethylated metabolites in unhydrolyzed postmortem specimens. Ten oxycodone positive postmortem cases were detected, and nine were drug-related fatalities. Five cases were attributed solely to oxycodone intoxication and four to polydrug intoxication. Although there was overlap between blood oxycodone levels in deaths attributed to oxycodone only and those due to polydrug intoxication, lower oxycodone levels (< 1 mg/L) were associated with polydrug intoxication when compared with cases due to oxycodone alone (> 1 mg/L). The role of the parent drug in oxycodone fatalities has been fully studied, but the role of oxycodone metabolites (noroxycodone and oxymorphone) was investigated in this report for the first time. Oxycodone was more commonly detected in blood, urine, and vitreous humor followed by noroxycodone. The ratio between oxycodone and its N demethylated metabolite was evaluated and found to be useful in determining whether death occurred shortly after drug administration or if there was a significant delay. High parent/metabolite ratios were correlated with short survival times after ingestion. The median ratio of oxycodone/noroxycodone was 2.4 and ranged from 0.7 to 49. Oxycodone prescriptions have risen sharply in Scotland in recent years, and the identification of 10 oxycodone-related deaths in the past 18 months highlights the importance of including this drug in routine laboratory screening and confirmation procedures. PMID- 19874649 TI - Comparison of oxycodone in vitreous humor and blood using EMIT screening and gas chromatographic-mass spectrometric quantitation. AB - Vitreous humor may serve as a useful alternative specimen for oxycodone analysis in death investigations where blood samples are not available or are of poor quality or limited quantity. The purpose of this study was to investigate the relationship between immunoassay results and gas chromatography-mass spectrometry (GC-MS) quantitation of oxycodone in postmortem vitreous humor and blood. When used with vitreous humor calibrators, the Microgenics DRI Oxycodone (EMIT) Assay was found to be linear from 25 to 500 ng/mL with an limit of detection of 25 ng/mL. Vitreous humor and postmortem blood precipitate immunoassay responses in 57 oxycodone-positive cases were found to be correlated (r(2) = 0.69, p < 0.01). Confirmation and quantitation of oxycodone in vitreous humor by GC-MS was linear from 50 to 1000 ng/mL with a limit of detection of 10 ng/mL and a limit of quantitation of 50 ng/mL. In 30 cases, oxycodone vitreous humor concentrations ranged from less than 50 to 945 ng/mL, and blood concentrations ranged from 103 to 768 ng/mL. The average vitreous humor/blood ratio was 1.16 and ranged from 0.12 to 3.26. Disparities between vitreous fluid and blood oxycodone concentrations were seen in a few cases. PMID- 19874650 TI - Urinary MDMA, MDA, HMMA, and HMA excretion following controlled MDMA administration to humans. AB - 3,4-Methylenedioxymethamphetamine (MDMA), or ecstasy, is excreted as unchanged drug, 3,4-methylenedioxyamphetamine (MDA), and free and glucuronidated/sulfated 4 hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) metabolites. The aim of this paper is to describe the pattern and timeframe of excretion of MDMA and its metabolites in urine. Placebo, 1.0 mg/kg, and 1.6 mg/kg oral MDMA doses were administered double-blind to healthy adult MDMA users on a monitored research unit. All urine was collected, aliquots were hydrolyzed, and analytes quantified by gas chromatography-mass spectrometry. Median C(max), T(max), ratios, first and last detection times, and detection rates were determined. Sixteen participants provided 916 urine specimens. After 1.6 mg/kg, median C(max) were 21,470 (MDMA), 2229 (MDA), 20,793 (HMMA), and 876 ng/mL (HMA) at median T(max) of 13.9, 23.0, 9.2 and 23.3 h. In the first 24 h, 30.2-34.3% total urinary excretion occurred. HMMA last detection exceeded MDMA's by more than 33 h after both doses. Identification of HMMA as well as MDMA increased the ability to identify positive specimens but required hydrolysis. These MDMA, MDA, HMMA, and HMA pharmacokinetic data may be useful for interpreting workplace, drug treatment, criminal justice, and military urine drug tests. Measurement of urinary HMMA provides the longest detection of MDMA exposure yet is not included in routine monitoring procedures. PMID- 19874651 TI - Sensitive method for detection of cocaine and associated analytes by liquid chromatography-tandem mass spectrometry in urine. AB - Cocaine (COC) is a potent CNS stimulant that is metabolized to benzoylecgonine (BE) and further metabolized to minor metabolites such as m hydroxybenzoylecgonine (m-HOBE). COC is also metabolized to norcocaine (NC). Cocaethylene (CE) is formed when cocaine and ethyl alcohol are used simultaneously. Anhydroecgonine methyl ester (AEME) is a unique marker following smoked cocaine, and anhydroecgonine ethyl ester (AEEE) is found in cocaine smokers who also use ethyl alcohol. We developed a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the detection and quantitation of COC, BE, NC, CE, m-HOBE, AEME, and AEEE in urine. Two hundred samples previously analyzed by gas chromatography (GC) coupled with MS were extracted using solid phase extraction. Chromatographic separation was achieved using a gradient consisting of mobile phase A [20 mM ammonium formate (pH 2.7)] and mobile phase B (methanol/acetonitrile, 50:50), an XDB-C(8) (50 x 2.1 mm, 1.8 microm) column and a flow rate of 270 microL/min. Concentrations were calculated by comparing the peak-area with the internal standard and plotted against a standard curve. The assay displayed linearity from 1.0 to 100 ng/mL. Within- and between-run coefficients of variation were < 10% throughout the linear range. A method comparison between GC-MS and LC-MS-MS showed good correlation for COC (r(2) = 0.982) and BE (r(2) = 0.955). We report here on a sensitive method to identify clinically and forensically relevant cocaine and associated analytes at concentrations as low as 1.0 ng/mL. PMID- 19874652 TI - Automated solid-phase extraction-liquid chromatography-tandem mass spectrometry analysis of 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid in human urine specimens: application to a high-throughput urine analysis laboratory. AB - An automated solid-phase extraction coupled with liquid chromatography and tandem mass spectrometry (SPE-LC-MS-MS) method for the analysis of 11-nor-Delta(9) tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in human urine specimens was developed. The method was linear (R(2) = 0.9986) to 1000 ng/mL with no carryover evidenced at 2000 ng/mL. Limits of quantification and detection were found to be 2 ng/mL. Interrun precision was evaluated at the 15 ng/mL level over nine batches spanning 15 days (n = 45). The coefficient of variation (%CV) was found to be 5.5% over the course of the validation. Intrarun precision of a 15 ng/mL control (n = 5) ranged from 0.58% CV to 7.4% CV for the same set of analytical batches. Interference was tested using (+/-)-11-hydroxy-Delta(9)-tetrahydrocannabinol, cannabidiol, (-)-Delta(8)-tetrahydrocannabinol, and cannabinol. One hundred and nineteen specimens previously found to contain THC-COOH by a previously validated gas chromatographic mass spectrometry (GC-MS) procedure were compared to the SPE LC-MS-MS method. Excellent agreement was found (R(2) = 0.9925) for the parallel comparison study. The automated SPE procedure eliminates the human factors of specimen handling, extraction, and derivatization, thereby reducing labor costs and rework resulting from human error or technique issues. Additionally, method runtime is greatly reduced (e.g., during parallel studies the SPE-LC-MS-MS instrument was often finished with analysis by the time the technician finished the offline SPE and derivatization procedure prior to the GC-MS analysis). PMID- 19874653 TI - Solid-phase extraction and analysis of THC and carboxy-THC from whole blood using a novel fluorinated solid-phase extraction sorbent and fast liquid chromatography tandem mass spectrometry. AB - In this study, solid-phase extraction (SPE) is described using a novel fluorinated [heptadecafluorotetrahydrodecyl (C(10)H(4)F(17))] phase to isolate THC and its primary metabolite carboxy-THC from whole blood samples. SPE was performed in hydrophobic mode after samples of whole blood were precipitated with acetonitrile. After applying the sample to the SPE column in aqueous phosphate buffer (pH 7), the sorbent was washed with deionized water and phosphate buffer (pH 7) and dried. The SPE column was eluted with a solvent consisting of ethyl acetate/hexanes (50:50) containing 2% acetic acid. The eluate was collected, evaporated to dryness, and dissolved in mobile phase (50 microL) for analysis by fast liquid chromatography-tandem mass spectrometry in positive/negative multiple reaction monitoring mode. Chromatography was performed in gradient mode employing a C(18) column and a mobile phase consisting of acetontitrile (containing 0.1% formic acid) and 0.1% aqueous formic acid. The total run time for each analysis was less than 5 min. The limits of detection/quantification for this method were determined to be 0.1 and 0.25 ng/mL, respectively. The method was found to be linear from 0.25 to 50 ng/mL (r(2) >or= 0.995). Recoveries of the individual cannabinoids were found to be greater than 85%. In this report, results of authentic samples analyzed for THC and carboxy-THC are reported using this new methodology. PMID- 19874655 TI - Determination of specific absorbance (A|) for Zaleplon (Sonata) by spectrophotometry. AB - Specific absorbance (A|) is the maximum absorbance of a 1% solution over a 1-cm path length as measured by a spectrophotometer. If a reliable A| determination is available for a drug, it provides an extremely useful tool for the quantitative verification of a stock drug solution. Zaleplon was introduced into the market in 1999, and although the drug has been available for 10 years, A| has not been published in the literature. Zaleplon's A| was experimentally determined by a spectrophotometer at 229 nm in aqueous acid and verified with three independent external sources to be 1186 (1042-1262; n = 18). The experimentally determined A| of zaleplon is beneficial to a toxicology laboratory to verify the quantitative accuracy of a drug solution prior to its use in casework. PMID- 19874654 TI - Implications of plasma Delta9-tetrahydrocannabinol, 11-hydroxy-THC, and 11-nor-9 carboxy-THC concentrations in chronic cannabis smokers. AB - Delta(9)-Tetrahydrocannabinol (THC) is commonly found in toxicological specimens from driving under the influence and accident investigations. Plasma cannabinoid concentrations were determined in 18 long-term heavy cannabis smokers residing on an in-patient research unit for seven days of monitored abstinence. THC, 11 hydroxy-THC, and 11-nor-9-carboxy-THC (THCCOOH) were quantified by two dimensional gas chromatography-mass spectrometry with cryofocusing. THC concentrations were > 1 ng/mL in nine (50.0%) participants (1.2-5.5 ng/mL) on abstinence day 7. THCCOOH was detected (2.8-45.6 ng/mL) in all participants on study day 7. THC and THCCOOH median percent concentration decreases (n = 18) were 39.5% and 72.9% from day 1 to 7, respectively. Most (88.9%) of the participants had at least one specimen with increased THC compared to the previous day. Cannabis use duration and plasma THCCOOH concentrations were positively correlated on days 1-3 (R = 0.584-0.610; p = 0.007-0.011). There were no significant correlations between THC concentrations > 0.25 ng/mL and body mass index on days 1-7 (R = -0.234-0.092; p = 0.350-0.766). Measurable THC concentrations after seven days of abstinence indicate a potential mechanism for residual neurocognitive impairment observed in chronic cannabis users. THC's presence in plasma for seven days of abstinence suggests its detection may not indicate recent use in daily cannabis users. PMID- 19874656 TI - Zaleplon (Sonata) analysis in postmortem specimens by gas chromatography-electron capture detection. AB - Zaleplon (Sonata) is a sedative hypnotic prescription medication used for the short-term treatment of insomnia. Although Zaleplon was approved by the FDA in 1999, there has been limited postmortem information about the drug cited in the toxicology literature. Zaleplon was separated from postmortem biological specimens utilizing liquid-liquid extraction coupled with a solid-phase extraction technique, and detection was accomplished by a gas chromatography electron capture detector. The method was linear from 5.0 to 150 ng/mL with the limit of quantitation and detection determined to be 3.0 and 0.50 ng/mL, respectively. The postmortem tissue distribution of zaleplon in seven cases was as follows: 6.1-1490 ng/mL central blood (seven cases), < 3.0-503 ng/mL femoral blood (five cases), 108 ng/mL harvest blood (one case), 343-679 ng/g liver (four cases), 950 ng/g spleen (one case), < 3.0-85 ng/mL bile (three cases), 3.8-106 ng/mL urine (four cases), < 3.0-486 ng/mL vitreous humor (five cases), and 0.005 3.4 mg total gastric contents (four cases). A validated method for the analysis of zaleplon and postmortem concentrations of autopsy specimens are reported to aid the forensic toxicologist with interpretation of future casework. PMID- 19874657 TI - Development of a homogeneous immunoassay for the detection of zolpidem in urine. AB - Sleep disorders are common conditions that affect about 40 million people in the U.S every year, the most common of which is insomnia, which is characterized by difficulty falling or staying asleep. Zolpidem (Ambien) is a non-benzodiazepine prescription drug that is used to treat insomnia and is often preferred over the commonly used benzodiazepines due to a lesser side effect profile. This is because the non-benzodiazepine binding is more selective to GABA-A receptors versus the non-selective binding of benzodiazepines. With the increasing popularity of non-benzodiazepines, drug abuse and driving-while-impaired cases involving sleep-inducing drugs have risen. Therefore, a highly sensitive and rapid homogeneous immunoassay (EMIT-type assay) has been developed for the detection of zolpidem in urine. The zolpidem antibody is highly specific and does not cross-react with other newer sleep aids such as zopiclone and zaleplon. This assay has a detection limit of 5 ng/mL for zolpidem in urine. Further evaluation of this assay using liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis of authentic urine samples demonstrated that the accuracy of the assay is greater than 90%. Because this assay is designed to measure the non-conjugated drug in urine, it resulted in simplification for gas chromatography-MS or LC-MS MS confirmation methods that do not require urine hydrolysis before solid-phase extraction or liquid-liquid extraction. PMID- 19874658 TI - Urinary detection times and excretion patterns of flunitrazepam and its metabolites after a single oral dose. AB - We investigated the excretion profiles of flunitrazepam metabolites in urine after a single dose. Sixteen volunteers received either 0.5 or 2.0 mg flunitrazepam. Urine samples were collected after 2, 4, 6, 8, 12, 24, 48, 72, 96, 120, 240, and 336 h. Samples were screened using CEDIA (300 microg/L cutoff) and quantitated using liquid chromatography-tandem mass spectrometry. The cutoff was 0.5 microg/L for flunitrazepam, N-desmethylflunitrazepam, 7-aminoflunitrazepam, 7 aminodesmethylflunitrazepam, 7-acetamidoflunitrazepam, and 7 acetamidodesmethylflunitrazepam. None of the subjects receiving 0.5 mg were screened positive, and only 23 of 102 samples from the subjects given 2.0 mg were positive with CEDIA. The predominant metabolites were 7-aminoflunitrazepam and 7 aminodesmethylflunitrazepam. For all subjects given the low dose, 7 aminoflunitrazepam was detected up to 120 h, and for two subjects for more than 240 h. Seven subjects given the high dose were positive up to 240 h for 7 aminoflunitrazepam. We conclude that the ratio 7-aminodesmethylflunitrazepam to 7 aminoflunitrazepam increased with time, independent of dose, and may be used to estimate the time of intake. For some low-dose subjects, the metabolite concentrations in the early samples were low and a chromatographic method may fail to detect the intake. We think laboratories should consider this when advising police and hospitals about sampling as well as when they set up strategies for analysis. PMID- 19874659 TI - Determination of beta-hydroxybutyrate in blood and urine using gas chromatography mass spectrometry. AB - Beta-hydroxybutyrate (BHB) is considered a potential biomarker for alcoholic ketoacidosis (AKA). A robust and sensitive method was developed and validated for the quantitative determination of BHB in postmortem blood and urine using deuterated gamma-hydroxybutyrate as an internal standard. Samples were analyzed by gas chromatography-mass spectrometry following liquid-liquid extraction and silyl derivatization. The limits of detection and lower limits of quantification in blood and urine were 2 and 7 mg/L and 2 and 6 mg/L, respectively. The interday and intraday precision was measured by coefficients of variation for blood and urine and ranged from 1.0 to 12.4% for quality control samples spiked at 50 and 300 mg/L. The linear range of 50-500 mg/L resulted in an average correlation of R(2) > 0.99, and the average extraction recoveries in blood and urine were >or= 82% and >or= 59%, respectively. BHB remains stable in blood spiked at a concentration of 300 mg/L for 15 days when stored within a refrigerator (2-5 degrees C). Postmortem blood and urine samples were analyzed using the validated method for cases where the deceased had a history of chronic alcohol abuse to establish the use of BHB as a potential marker of AKA. PMID- 19874660 TI - Ethylene glycol and glycolic acid in postmortem blood from fatal poisonings. AB - Ethylene glycol (EG), a relatively infrequent cause of fatal intoxication, presents an analytical challenge for forensic confirmation in postmortem toxicology. We report EG and glycolic acid (GA) quantification in postmortem blood by gas chromatography coupled with ion trap mass spectrometry (GC-MS) analysis using a modification of a previously reported clinical method. The method is linear from 50 to 4000 mg/L with a limit of detection of 25 mg/L for both EG and GA. Interassay coefficient of variation (2.1-8.6%, 4.3-6.0%) and accuracy (96-101%, 92-105%) were determined for EG and GA, respectively. EG concentration by ion trap GC-MS correlated closely (R(2) = 0.995) with EG quantified by GC-flame-ionization detection. Analysis of blood from 20 autopsies with no evidence of EG exposure did not reveal detectable EG or GA. In 12 medical examiner cases with EG poisoning as cause of death, EG concentrations ranged widely from 58 to 7790 mg/L with a mean of 1830 mg/L, and the GA concentration averaged 1360 mg/L with a narrower range of 810-1770 mg/L. EG and GA levels correlate poorly (R(2) = 0.15) in postmortem blood with discordantly low EG concentrations in two cases. Birefringent oxylate crystals in renal tissue was a consistent finding. In conclusion, a sensitive and specific GC-MS method for detection and quantification of EG and GA has been validated and a study of fatal EG poisonings revealed forensic application of the method. PMID- 19874661 TI - Examination of some performance characteristics of breath alcohol measurements obtained with the intoxilyzer 8000C following social drinking conditions. AB - The Intoxilyzer 8000C was used to measure breath alcohol concentration (BrAC) in 10 healthy subjects under social drinking conditions. Measurements commenced within 5 min of the end of drinking (EOD). For 14 blood-breath pairs, measured BrACs were compared to corresponding venous blood alcohol concentrations (vBAC) of samples drawn at least 30 min after EOD and within 5 min of the corresponding breath test. BAC was analyzed using an enzymatic method. Concentration differences between breath and blood (BrAC - vBAC) ranged from -32 to +3 mg/dL (untruncated BrAC) and from -32 to -4 mg/dL (truncated BrAC). The Invalid Sample message was actuated in five out of 23 BrAC profiles. In the remaining 18 samples, residual mouth alcohol was evaluated by comparing the maximum difference between successive (5 min apart) measurements (MID5) over 20-30 min after EOD with the precision of replicate BrAC values taken 30-40 min after EOD (5 mg/dL or less; precision unaffected by breath sample volume over the range of 2-3 L). MID5 values occurred within the first three measurements in 16/18 cases, indicative of a significant mouth alcohol effect. Thus, mandatory delays should be used with the Intoxilyzer 8000C prior to testing to minimize the probability of overestimation of BrAC due to mouth alcohol. PMID- 19874662 TI - Manual versus automatic sampling variations of a preliminary alcohol screening device. AB - Utilization of a manual sampling function as an alternative to the automatic sampling function in the Alco-Sensor IV Black Dot Model has been recognized by the manufacturer to potentially underestimate an individual's true breath alcohol content (BrAC). A controlled human subject study was conducted to analyze the possible breath-sampling differences between the standard automatic technique and three manual techniques. Subjects were dosed with vodka and orange juice and then tested during the descending limb of their BrAC curve. Differences between the automatic and the manual techniques were found to be statistically significant with the three manual techniques underestimating the BrAC. The average maximum difference between the automatic BrAC level, as compared to the lowest manual level in each data set, was 27.9% (median 27.7%) with underestimations from 20.8% to 40.0%. In no instance did any of the manual techniques produce higher BrACs than the automatic technique. PMID- 19874663 TI - Convenient headspace gas chromatographic determination of azide in blood and plasma. AB - Azide in human blood and plasma samples was derivatized with propionic anhydride in a headspace vial without prior sample preparation. The reaction proceeds quickly at room temperature to form propionyl azide. A portion of the headspace was assayed by gas chromatography with a nitrogen-phosphorus detector. In the heated injector of the gas chromatograph, the propionyl azide undergoes thermal rearrangement, forming ethyl isocyanate, which is subsequently chromatographed and detected. Propionitrile was used as the internal standard. The method is linear to at least 20 microg/mL. Limit of quantitation was 0.04 microg/mL, and the within-run coefficient of variation was 5.6% at 1 microg/mL. There was no interference from cyanide. A fatality report in which blood and plasma azide concentrations from a 59-year-old man were monitored for 24 h following the ingestion of an unknown amount of sodium azide is presented. The patient became critically ill after his self-inflicted sodium azide ingestion. He was intubated and treated with vasopressors and aggressive supportive care, including extracorporeal membrane oxygenation therapy, in the intensive care facility but died from neurological brain damage secondary to anoxia. On admission, 1.4 h after ingestion, his azide level was 5.6 microg/mL (blood); shortly thereafter, it had risen to 13.7 microg/mL (plasma) and, subsequently, was projected to have been eliminated by 16.7 h. No azide was detected in the postmortem blood and vitreous humor. PMID- 19874664 TI - The uncertainty of reference standards--a guide to understanding factors impacting uncertainty, uncertainty calculations, and vendor certifications. AB - Certified solution standards are widely used in forensic toxicological, clinical/diagnostic, and environmental testing. Typically, these standards are purchased as ampouled solutions with a certified concentration. Vendors present concentration and uncertainty differently on their Certificates of Analysis. Understanding the factors that impact uncertainty and which factors have been considered in the vendor's assignment of uncertainty are critical to understanding the accuracy of the standard and the impact on testing results. Understanding these variables is also important for laboratories seeking to comply with ISO/IEC 17025 requirements and for those preparing reference solutions from neat materials at the bench. The impact of uncertainty associated with the neat material purity (including residual water, residual solvent, and inorganic content), mass measurement (weighing techniques), and solvent addition (solution density) on the overall uncertainty of the certified concentration is described along with uncertainty calculations. PMID- 19874665 TI - Validation of a spectrophotometric method for quantification of carboxyhemoglobin. AB - The measurement of carboxyhemoglobin (COHb) levels in blood is a valuable procedure to confirm exposure to carbon monoxide (CO) either for forensic or occupational matters. A previously described method using spectrophotometric readings at 420 and 432 nm after reduction of oxyhemoglobin (O(2)Hb) and methemoglobin with sodium hydrosulfite solution leads to an exponential curve. This curve, used with pre-established factors, serves well for lower concentrations (1-7%) or for high concentrations (> 20%) but very rarely for both. The authors have observed that small variations on the previously described factors F1, F2, and F3, obtained from readings for 100% COHb and 100% O(2)Hb, turn into significant changes in COHb% results and propose that these factors should be determined every time COHb is measured by reading CO and O(2) saturated samples. This practice leads to an increase in accuracy and precision. PMID- 19874666 TI - Prevalence of gabapentin in impaired driving cases in Washington State in 2003 2007. AB - Gabapentin (Neurontin) is an antiepileptic drug commonly prescribed for pain treatment. In the past 15 years, indications for gabapentin have been increasing even though the complete mechanism of action is unknown. Side effects include somnolence, dizziness, ataxia, nystagmus, and fatigue. This study reviewed all cases positive for gabapentin submitted to the Washington State Toxicology Laboratory between January 2003 and December 2007. The concentrations of gabapentin in blood from impaired driving cases (n = 137) ranged from < 2.0 to 24.7 mg/L with a mean of 8.4 +/- 5.4 mg/L and a median of 7.0 mg/L. The driving population was 50% male with a mean age of 43.0 +/- 10.9 years (range 23-73). Of the cases studied, only 7% were positive for gabapentin alone with the remaining 93% indicative of polydrug use. Drug Recognition Expert reports from four cases in which the only drug detected likely to be causing impairment was gabapentin were examined. These reports demonstrated that subjects may exhibit psychophysical indicators of a central nervous system depressant (e.g., horizontal gaze nystagmus, poor performance on standardized field sobriety tests) with clinical indicators (e.g., dilated pupils, low body temperature, and elevated pulse and blood pressure) that are not consistent with a depressant. PMID- 19874668 TI - Hair analysis to demonstrate administration of sildenafil to a woman in a case of drug-facilitated sexual assault. AB - The drug sildenafil (Viagra, Pfizer) and, more recently, tadalafil (Cialis, Lilly Icos) and vardenafil (Levitra, Bayer), has drawn public attention to aphrodisiacs. The search for such substances dates back millennia. Adverse effects associated with these drugs include hypotension, tachycardia, headache, flushing, blurred vision, dyspepsia, and musculoskeletal pain. Although sildenafil has been marketed for erection of the penis, recent attention has been paid to its application for women, including enhancement of success of in vitro fertilization but also better sexual responses (increased desire, satisfaction, and orgasm) in cases of sexual disorders. Today, there is a debate on internet forums about the potential properties of sildenafil to enhance women's sexual pleasure. This laboratory was asked to analyze a 12-cm length of light brown hair submitted by a British police force following an allegation that a young female had been subjected to sexual assaults over a two-year period. The female was 15 17 years of age at the time. The alleged perpetrator was her stepfather, and there was some suspicion that drugs may have been administered to facilitate the attacks. After decontamination and segmentation (6 x 2-cm section), the specimen was analyzed by liquid chromatography coupled with tandem mass spectrometry after alkaline (pH 9.5) extraction using dichloromethane/ isopropanol/n-heptane (25:10:65, v/v/v). The limit of quantitation was 5 pg/mg. The proximal segment tested positive for sildenafil at 38 pg/mg, and all others proved negative. This was in accord with the victim's claim. In the absence of any controlled studies, it was impossible to put any quantitative interpretation on the measured concentration. PMID- 19874667 TI - Cocaine detection in postmortem samples following therapeutic administration. AB - Cocaine is one of the most widely abused drugs and one that is frequently encountered in forensic toxicology laboratories. Most often, the detection of cocaine would lead toxicologists and forensic pathologists to believe that the drug was used illicitly; however, cocaine is an effective local anesthetic and vasoconstrictor and is used clinically in surgeries of the eye, ear, nose, and throat. Therefore, it is important to note that the presence of cocaine and its metabolites in forensic samples cannot always be attributed to abuse and that a thorough investigation and review of medical records is warranted before an informed conclusion can be made. In this case report, a 54-year-old male died three days after an altercation in which he suffered multiple injuries. In addition to natural disease and injuries documented at autopsy, cocaine and its metabolites were detected in the decedent's urine, and a review of surgical records showed that earlier on the day of death, he was administered cocaine clinically during a procedure to repair nasal bone fractures. If not for this comprehensive investigation and review of surgical records, the assumption of cocaine abuse might have otherwise been made and the cause and manner of death incorrectly established. PMID- 19874669 TI - A fatality from an oral ingestion of methamphetamine. AB - The case presented is of a 49-year-old white male decedent who admitted to oral ingestion of methamphetamine. He believed he was being followed by the police while walking his daughter to school in the morning and swallowed the "8-ball of meth," which is known to be one-eighth of an ounce or the equivalent of about 3 g. The following autopsy specimens were analyzed for the presence of methamphetamine and amphetamine by gas chromatography-mass spectrometry: femoral blood, urine, bile, vitreous fluid, brain, liver, and gastric contents. Blood drawn at the hospital approximately 12 h after ingestion was also analyzed. The methamphetamine concentration in the hospital blood was 3.0 mg/L, and the concentration in the femoral blood from autopsy was 30 mg/L. Other drugs confirmed included tramadol, lorazepam, and 11-carboxy-Delta(9) tetrahydrocannabinol. The pathologist ruled the cause of death to be cardiac dysrhythmia due to excited delirium as a result of methamphetamine drug effects. Discussion of the timeline from ingestion to death and the clinical presentation of the decedent are included. PMID- 19874670 TI - Evaluation of potential lactate/lactate dehydrogenase interference with an enzymatic alcohol analysis. AB - The Connecticut Department of Public Safety laboratory recently addressed a legal challenge to a hospital alcohol dehydrogenase (ADH)-based serum ethanol determination based on the suggestion of interference by lactate dehydrogenase (LDH)-catalyzed oxidation of lactate. Both ADH- and LDH-oxidations require NAD(+) (present in excess in the assay). NADH produced by LDH-catalyzed lactate oxidation in the assay is interpreted as derived from ethanol. Hepatic trauma was suggested as the basis for elevated levels of lactate and LDH. Clinical laboratory results were evaluated, specifically serum hepatic enzymes, ions, and anion gap. Aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were 229 and 144 U/L, respectively (approximately 8x and 4x reference range midpoint values). Na(+), K(+), Cl(-), and CO(2) levels were 143, 3.0, 112, and 20 meq/L, respectively, yielding an anion gap of 8 meq/L (ref. range 8-15). Serum lactate contributes to "unmeasured anions"; hence, the anion gap was inconsistent with a significant lactate elevation. Based on the slight elevation of ASAT and ALAT, LDH levels were estimated to be elevated to no more than 10-fold. Calculation of the amount of LDH and ADH present in the ethanol assay suggest an ADH/LDH ratio of 200:1. Hence, contribution by lactate oxidation to the serum ethanol concentration in this case would have been negligible. PMID- 19874671 TI - A fatality due to cyproheptadine and citalopram. AB - Cyproheptadine (Periactin) is a first-generation antihistamine available in over the-counter cold medications and is used to treat allergic-type symptoms. Although antihistamines in general have long been known to cause serious side effects, especially when taken in overdose, few reports that specifically address cyproheptadine-related fatalities exist. A 42-year-old healthy female was found dead at her home with no anatomic cause of death and a recent history of suicidal ideations. Toxicology revealed cyproheptadine and citalopram in the femoral postmortem blood at concentrations of 0.49 and 2.3 mg/L, respectively. Vitreous, urine, and bile analysis were also performed, yielding concentrations of < 0.04 and 0.80 mg/L in the vitreous for cyproheptadine and citalopram, respectively; 0.23 and 8.2 mg/L in the urine; and 30.7 and 9.0 mg/L in the bile. The cause of death was determined to be cyproheptadine and citalopram intoxication, and the manner was ruled a suicide. Although cyproheptadine is widely available in the United States and Europe, there are only two published fatalities due to this antihistamine and only one that specifically cites blood and tissue concentrations. Therefore, this case study will be beneficial to the forensic toxicology community by providing additional information regarding postmortem interpretation. PMID- 19874672 TI - Comparison of bone marrow stromal cell behaviors on poly(caprolactone) with or without surface modification: studies on cell adhesion, survival and proliferation. AB - Poly(caprolactone) (PCL) is a promising biodegradable polymer for tissue engineering. However, intrinsically poor cell-adhesive properties of PCL may limit its application. In this study, the PCL film surface was modified with RGDC peptide by a chemical immobilization procedure. Furthermore, bone marrow stromal cell (BMSC) behaviors including attachment, spreading, focal adhesion formation, focal adhesion kinase (FAK) activation, apoptosis and proliferation when cultured on the modified PCL films were investigated. Our results demonstrated that PCL with RGD modification promoted initial BMSC attachment, spreading and focal adhesion formation. At a later time point (12 h), BMSC attachment on both RGD peptide-modified PCL and PCL-NH(2) films significantly increased compared to untreated PCL films. Importantly, FAK phosphorylation was significantly increased only on the films with RGD-modified films, not on the PCL-NH(2) films, demonstrating that PCL with RGD modification had an advantage in initiating the specific integrin-mediated signal transduction and might play an important role in the subsequent retardation in cell death and enhancement in cell proliferation. The present results provide more evidence that functionalizing PCL with RGD peptides may be a feasible way to improve the interaction between BMSC and PCL substrate, which is important in tissue engineering. PMID- 19874673 TI - Fabrication of nano-fibrous PLLA scaffold reinforced with chitosan fibers. AB - In this study, a nano-fibrous PLLA scaffold reinforced by micro-scale chitosan fibers was fabricated using thermally-induced phase separation (TIPS). The morphology, porosity, mechanical performance and pH changes in in vitro degradation of the scaffold were also investigated. Results showed that the mechanical properties of the scaffold increased with the amount of chitosan fibers embedded, and the pH in in vitro degradation of the scaffold changed more slowly than that of the pure nano-fibrous PLLA scaffold without chitosan fibers. The new composite scaffold might be a very promising scaffold for tissue engineering. PMID- 19874674 TI - Effects of precursor and cross-linking parameters on the properties of dextran allyl isocyanate-ethylamine/poly(ethylene glycol diacrylate) biodegradable hydrogels and their release of ovalbumin. AB - In this paper, we studied the effects of molecular weight of poly(ethylene glycol diacrylate) (PEGDA) precursor, the degree of substitution (DS) of both allyl isocyanate (AI) and amine groups in dextran-based precursor (Dex-AE), and photoinitiator concentration on Dex-AE/PEGDA hydrogel formation and its ovalbumin (OVA) release. FT-IR spectra showed chemical bond interaction between amine and urethane groups of the hydrogel carriers with OVA. The increase in PEGDA molecular weight led to a faster OVA release because of a more open gel network structure. The study on the DS of AI in Dex-AE precursor showed that an increase in AI did not result in a prominent gel network structure difference. However, the urethane groups in Dex-AE precursor showed some interactions with OVA and, thus, resulted in a slower release rate. The incorporation of amine group into Dex-AE precursor did not affect the gel network structure, but reduced the OVA release rate, and the level of reduction increased with an increasing amine group substitution into the Dex-AE precursor. This reduction could be attributed to the interaction between the amine groups in the gel carrier and OVA. An increase in the photoinitiator concentration showed no effect on the gel network structure or OVA release. PMID- 19874675 TI - Synthesis and drug-release behavior of porous biodegradable amphiphilic co polymeric hydrogels. AB - A series of amphiphilic random block co-polymers were synthesized by the condensation of hydrophobic polycaprolactone diol (PCL diol) with hydrophilic dicarboxy poly(ethylene glycol) (PEG-diacid), obtained by reacting poly(ethylene glycol) (PEG) with succinic anhydride. The PEG/PCL random block co-polymers were then acrylated with acryloyl chloride to form PEG/PCL diacrylates (PCEdA), and then characterized by FT-IR, (1)H-NMR and GPC. The porous biodegradable gels were prepared through photo-polymerization of the PCEdA dissolved in DMSO at low temperature. Thermal behavior, swelling ratio and morphological characteristics as well as biodegradability of the presented gels were investigated. Results showed that the swelling ratio of the gel in deionized water increased with an increase of the PEG chain length in the copolymeric gel. DSC thermograms indicated that the melting point of the PCEdA was lower than that of PCL and PEG blocks, but a new crystalline peak of the co-polymeric gel appeared with increasing of the segmental length of the PEG. Thermal stability of PCE gel was higher than that of PCE diol. The pore size of the gel was influenced by the concentration of PCEdA. The drug-release behavior of PCE gels was also investigated. PMID- 19874676 TI - Modification of polydimethylsiloxane surfaces using benzophenone. AB - New biocompatible materials have been obtained by different modifications of polydimethylsiloxane (PDMS) surfaces. PDMS is of great interest for several biomedical applications. For some applications the native silicone does not provide an optimal performance. PDMS attracts proteins and salts. To reduce protein adhesion and salt deposition selected monomers were grafted by radical polymerization on the silicone surface. The conditions for surface modifications of PDMS using benzophenone as UV initiator were optimized. The modified surfaces were characterized properly using different methods. The effect of surface modifications on the albumin, as model protein, deposition was tested in an in vitro model. PMID- 19874677 TI - Synthesis of optically active helical poly(2-methoxystyrene). Enhancement of HeLa and osteoblast cell growth on optically active helical poly(2-methoxystyrene) surfaces. AB - Poly(2-methoxystyrene)s (P2MS) were synthesized using n-BuLi in THF and toluene at various temperatures. At -20 degrees C and higher temperatures, toluene was an effective polymerization solvent for synthesizing poly(2-methoxystyrene). Under these conditions, polymers with good yields and reasonable molecular weight distributions were obtained. Polymers synthesized under all conditions were isotactic; the most highly isotactic polymer was obtained in toluene at -20 degrees C. The m (isotactic dyad) content of the polymers synthesized in toluene at 0 degrees C and -20 degrees C was 0.65 and 0.74, respectively. Optically active helical (+) and (-) P2MS were synthesized by asymmetric polymerization utilizing (+) or (-) [2,3-dimethoxy1,4(dimethylamino)butane] (DDB)/tolyl lithium initiating complex in toluene. Asymmetric polymerizations were also carried out at 0 degrees C to synthesize optically active polymers. The optical rotations of the polymers were found to be dynamic and reversible, strongly suggesting contribution of the chiral higher ordered structure to the overall optical rotation. Geometry optimization carried out using various force fields such as MM+, AMBER and CHARMM suggests that isotactic P2MS form low energy stable helical conformations. HeLa cells showed better growth on surfaces prepared using chiral polymers compared to the surfaces prepared with achiral polymers. Similarly, chiral P2MS surfaces were also more effective as supports for mouse and human osteoblast cells. The cell attachment and growth data demonstrate that chiral P2MS surfaces were better supports compared to achiral P2MS surfaces. Atomic force microscopy (AFM) studies on surfaces prepared using chiral poly(2 methoxystyrene) showed more discrete topography features compared to surfaces prepared with achiral polymers. Thus, the surface topography may play a role in determining polymer-cell interactions. PMID- 19874678 TI - Isolation and biochemical characterisation of a novel collagen from Catostylus tagi. AB - A preliminary biochemical approach to the study of collagen isolated from the medusa Catostylus tagi is reported and results are discussed in view of its use as a natural matrix for biomedical applications. Collagen from the jellyfish umbrella was isolated by pepsin digestion and purified by dialysis and salt precipitation. As expected, glycine represented almost one-third of the total amino acids. Aromatic amino-acid content was very low and imino acids were fewer than in collagens from fish and mammalian sources. Results from SDS-PAGE, ion exchange chromatography and N-terminal amino-acid sequencing revealed an alpha1alpha2alpha3 heterotrimer, similar to vertebrate type V/XI. The molecular mass of two of the polypeptide chains was close to 85 kDa and 100 kDa for the third. However, the two chains presenting similar molecular mass, showed differences in charge and primary structure. Further characterisation showed a glycosylated protein with the carbohydrate moiety comprising almost 7% of the total mass, a denaturation temperature of 29.9 degrees C and multiple isoelectric points. Incubation with glutamyl endopeptidase resulted in significant digestion, in agreement with the protein's high content of Asp and Glu. PMID- 19874679 TI - Three-dimensional plotter technology for fabricating polymeric scaffolds with micro-grooved surfaces. AB - Various mechanical techniques have been used to fabricate biomedical scaffolds, including rapid prototyping (RP) devices that operate from CAD files of the target feature information. The three-dimensional (3-D) bio-plotter is one RP system that can produce design-based scaffolds with good mechanical properties for mimicking cartilage and bones. However, the scaffolds fabricated by RP have very smooth surfaces, which tend to discourage initial cell attachment. Initial cell attachment, migration, differentiation and proliferation are strongly dependent on the chemical and physical characteristics of the scaffold surface. In this study, we propose a new 3-D plotting method supplemented with a piezoelectric system for fabricating surface-modified scaffolds. The effects of the physically-modified surface on the mechanical and hydrophilic properties were investigated, and the results of cell culturing of chondrocytes indicate that this technique is a feasible new method for fabricating high-quality 3-D polymeric scaffolds. PMID- 19874680 TI - The MPEG monophosphate ester: synthesis and characterization. AB - Methods of preparation of the phosphoric ester of monomethyl ether of poly(ethylene glycol) (MPEG-P) from MPEG (M(n) = 550 and 2000) and phosphoric acid (P), or its derivatives - pyrophosphoric acid (PY), polyphosphoric acid (PP) and POCl(3)- are described and compared. MPEG-P was isolated in a pure state (no detectable impurities) and characterized. PMID- 19874681 TI - Biocompatibility, alignment degree and mechanical properties of an electrospun chitosan-P(LLA-CL) fibrous scaffold. AB - Chitosan-poly(L-lactide-co-epsilon-caprolactone) (P(LLA-CL)) complex fibers, fibrous mats and a tubular scaffold have been obtained through electrospinning. Due to their high porosity, there were more porcine iliac artery endothelial cells (PIECs) attached to fiber mats than to tissue-culture plate (TCP) and coverslips. The cells could grow and spread well on nanofiber mats. There were many of native extracellular matrix (ECM)-like colloids above and under the surface of fibrous mats after cell culturing. The two-dimensional fast Fourier transform (2-D FFT) approach was used to analysis alignment degree of fibers collected on a rotary mandrel. The relations among mechanical properties, alignment degree, fiber diameter and rotary speed are discussed. Aligned fibers with various alignment degrees could be found through adjusting rotary speed. Fiber alignment was the variable most closely associated with the regulation of stress and strain. In this study, we show a feasible approach for producing scaffold with controllable mechanical property for soft tissue engineering through electrospinning. PMID- 19874682 TI - Fabrication, characterization of chitosan/nanosilver film and its potential antibacterial application. AB - In this work chitosan/silver nanoparticle films were synthesized by a simple photochemical method of reduction of silver ions in an acidic solution of AgNO(3) and chitosan. This is a novel, cheap, easy, quick and in situ approach to prepare chitosan films loaded with silver nanoparticles (AgNPs). Chitosan used here is a natural polymer and acts as a very good chelating and stabilizing agent; thus, this approach of formation of chitosan/silver nanoparticle films is proved to be an excellent 'green approach' for the synthesis of metal nanoparticle composites. The presence of silver nanoparticles was confirmed from the transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) of the film. The surface plasmon resonance (SPR) obtained at 400 nm also confirmed the presence of nanosilver in the chitosan film. The developed chitosan nanosilver films demonstrated excellent antibacterial action against model bacteria, Escherichia coli and Bacillus. This approach can be easily used in the large-scale production of such silver-nanoparticles-loaded chitosan films. These films can be used as antimicrobial packaging materials, as wound dressings and can also be grafted onto various implants. PMID- 19874683 TI - [Focusing on the treatment of chronic hepatitis B]. PMID- 19874684 TI - [The efficacy of nucleoside/nucleotide analogue on chronic hepatitis B]. PMID- 19874685 TI - [Interferon therapy for chronic hepatitis B]. PMID- 19874686 TI - [Dissection of mechanism for the adefovir dipivoxil resistance in chronic hepatitis B patients]. AB - OBJECTIVE: To explore the mechanism for adefovir dipivoxil (ADV) resistance occurred in chronic hepatitis B patients of a series of phase III clinical trails. METHODS: 30 resistant HBV strains were selected out from 177 cases of ADV treated chronic hepatitis B patients. HBV polymerase RT region were amplified by nested PCR and analyzed with the standard nucleotide sequence of HBV strains deposited in GeneBank. RESULTS: 21 out of 30 HBV strains were primary resistant strains, among them 5 HBV strains (23.8%, 5/21) had the polymorphism site of rtN118H. While the other 9 HBV strains showed secondary resistance, variations in conservative region C (rtM207V) and other non-conservative regions were found. The classic mutation sites such as rtN236T and rtA181V/T were not found. CONCLUSIONS: Polymorphism site of rtN118H might be responsible for HBV primary resistance to ADV therapy. rtM207V variation in HBV RT C domain and other variation sites might play a role in HBV secondary resistance to ADV treatment, and natural resistant quasispecies may be the basis for the ADV quick resistance. These conclusions await further confirmation by phenotype test. PMID- 19874688 TI - [Association between the serum HBV DNA loads normalized to hepatic parenchyma cell volume and the liver histopathologic inflammation gradings in the immune clearance phase]. AB - OBJECTIVE: To investigate the relationship between the serum HBV DNA loads normalized to hepatic parenchyma cell volume and the liver histopathologic inflammation gradings in the immune clearance phase during the natural history of hepatitis B. METHODS: Serum HBV DNA loads were detected by fluorescence polymerase chain reaction and normalized to hepatic parenchyma cell volume. The association between normalized HBV DNA loads and liver inflammation histopathologic grade were analyzed. RESULTS: The serum HBV DNA loads in patients with liver inflammation histopathologic grading 1, 2, 3 and 4 were 8.20*10(5)+/ 9.11*10, 1.36*10(6)+/-5.96*10, 8.12*10(5)+/-8.01*10 and 2.08*10(6)+/-3.69*10 copies/ml, respectively (P more than 0.05). But the serum HBV DNA loads normalized to hepatic parenchyma cell volume in their located fibrosis stage were 9.24*10(8)+/-935, 5.33*10(9)+/-756, 1.06*10(10)+/-1770 and 3.31*10(11)+/-518 copies/ml, respectively (P less than 0.05). CONCLUSION: The serum HBV DNA load normalized to hepatic parenchyma cell volume in patients with different fibrosis stages is associated with liver histopathologic inflammation gradings. PMID- 19874687 TI - [Comparison of liver pathohistological and clinical characteristics between chronic HBV carriers and chronic hepatitis B patients with mild elevation in ALT]. AB - OBJECTIVE: To compare the liver pathohistological and clinical features between chronic HBV carriers and chronic hepatitis B patients with mild elevated in ALT. METHODS: 128 patients were divided into 3 groups according to the ALT: group A: ALT is less than or equal to 0.5*ULN, group B: 0.5*ULN less than ALT is less than or equal to 1*ULN, group C: 1*ULN less than ALT less than 2*ULN. The age, sex, serum HBV DNA, HBeAg status, expression of HBcAg in liver, thickness of spleen, breadth of portal vein ,blood stream speed of protal vein, right liver obliqua diameter, grade of liver inflammation and stage of liver fibrosis were compared in the three groups. RESULTS: Among 128 patients, 57(44.5%) patients had G1 hepatitis and 71 (55.5%) had G2 hepatitis, no G0 hepatitis was found in these patients; 72 patients (56.3%) had S1 fibrosis, 30 (23.4%) patients had S2 fibrosis, and 26 (20.3%) patients did not have liver fibrosis. The liver inflammation in group C was more aggravated than that in group A (P less than 0.05). And there were significant differences in thickness of spleen and right liver obliqua diameter between group C and group A, as well as between group C and B (P all less than 0.01). With the aggravating of liver inflammation, the serum ALT, thickness of spleen, breadth of portal vein and expression of HBcAg in liver were increased obviously (P less than 0.05). With the aggravating of liver fibrosis, the thickness of spleen, breadth of portal vein, right liver obliqua diameter and HBeAg negative patients were increased obviously, while the blood stream speed of portal vein was decreased obviously (P less than 0.01). CONCLUSION: Among the chronic HBV infection patients whose ALT less than 2*ULN, there were 55.5% patients had G2 of liver inflammation and 23.4% patients had S2 of liver fibrosis. The serum ALT, thickness of spleen, breadth and blood stream speed of portal vein, right liver obliqua diameter and expression of HBcAg in liver are associated with pathohistological changes in these patients. PMID- 19874689 TI - [Early prediction of lamivudine response in e antigen-negative chronic hepatitis B patients]. AB - OBJECTIVE: To evaluate the effects of ALT, HBsAg and HBV DNA at the baseline, 4 and 12 weeks after lamivudine treatment on the long term (104 weeks) response in e antigen-negative chronic hepatitis B patients. METHODS: 127 adult e antigen negative chronic hepatitis B patients were enrolled in this study. All patients received treatment on LAM 100 mg/d for at least 104 weeks. The liver function, serum HBV markers and HBV viral load were regularly checked during the treatment. The effects of ALT, HBsAg and HBV DNA at the baseline, 4 and 12 weeks after lamivudine treatment on the response at 104 weeks were statistically analyzed. RESULTS: The proportion of patients with serum HBV DNA less than 1000 copies / ml at 104 weeks after LAM treatment was 50.0% and 86.8% in patients with baseline ALT less than 5 ULN and ALT is more than or equal to 5 ULN, respectively (P less than 0.01). In patients with baseline HBsAg less than 2000 COI and HBsAg is more than or equal to 2000 COI, the proportion of patients with serum HBsAg less than 500 COI at 104 weeks after LAM treatment was 19.1% and 17.5%, respectively (P more than 0.05). the HBsAg serological conversion rates were respectively 2.1% and 2.5% , respectively (P more than 0.05), the proportion of patients with serum HBV DNA less than 1000 copies/ml was 61.7% and 67.5%, respectively (P more than 0.05). In patients with baseline HBV DNA less than 10(6) copies/ml and HBV DNA is more than or equal to 10(6) copies/ml, the proportion of patients with HBV DNA less than 1000 copies/ml were statistically different at 4 weeks and 12 weeks after treatment, however, the proportion of patients with HBV DNA less than 1000 copies/ml at 104 weeks after LAM treatment was 62.7% and 67.1%, respectively (P more than 0.05). In patients with HBV DNA less than 1000 copies/ml and HBV DNA is more than or equal to 1000 copies/ml at 4 weeks after treatment, the proportion of patients with HBV DNA less than 1000 copies/ml at 104 weeks after LAM treatment was 70.7% and 60.9%, respectively (P more than 0.05). In patients with HBV DNA less than 1000 copies/ml and HBV DNA is more than or equal to 1000 copies/ml at 12 weeks after treatment, the proportion of patients with HBV DNA less than 1000 copies/ml at 104 weeks after treatment was 78.8% and 38.1%, respectively (P less than 0.01). CONCLUSION: e antigen negative chronic hepatitis B patients with baseline ALT is more than or equal to 5 ULN and HBV DNA less than 1000 copies/ml at 12 weeks after treatment have better virological response at 104 weeks after LAM treatment. The baseline HBsAg and HBV DNA load are associated with the virological response at 104 weeks after LAM treatment. PMID- 19874690 TI - [The study on the relationship between expression of B7-H1 on HBV transgenic mice and immune tolerance to HBV]. AB - OBJECTIVE: To investigate whether there is an association between the expression of B7-H1 in HBV transgenic mice and the immune tolerance to HBV. METHODS: T cells stimulatory capacity of DC was analyzed using mixed lymphocyte reaction. Expression of MHC-II, CD80, CD86, B7-H1 on DC was detected by Flow Cytometry. IL 2, IFNgamma, IL-10 production of T cells were determined by using ELISA. B7-H1 mRNA and protein expression in liver tissue were detected by RT-PCR and Western blotting respectively. RESULTS: The ability of DC cells from HBV transgenic mice to stimulate T cell proliferation was significantly impaired compared with DC cells from control mice (t = 16.674, 19.674, 21.712, P less than 0.01). Expression of MHC-II, CD80 on DC was markedly decreased in transgenic mice (t = 7.910, 6.413, P less than 0.05). Meanwhile, the expression of CD86 and B7-H1 on DC cells in HBV transgenic mice were not significantly different from that in control mice. The levels of IL-2, IFNgamma, IL-10 in supernatant of T cells was significantly lower compared with controls (t = 18.712, 18.712 and 11.683, P less than 0.05). There was no significant difference in B7-H1 expression at mRNA and protein levels in liver tissue compared with controls. CONCLUSIONS: Functional defect of DC, partly due to decreased expression of MHC-II, CD80, but not related to B7-H1 expression, is the cause for immune tolerance to HBV in HBV transgenic mice. PMID- 19874691 TI - [The change of intestinal mucosa barrier in chronic severe hepatitis B patients and clinical intervention]. AB - OBJECTIVE: To study the change of intestinal mucosa barrier in chronic severe hepatitis B patients and clinical intervention. METHOD: (1) 30 normal healthy controls and 60 chronic severe hepatitis B patients were enrolled in this study. The change of intestinal permeability was determined by urine lactulose/ mannitol ratio (L/M), and the serum diamine oxidase (DAO) was measured. (2) 60 chronic severe hepatitis B patients were randomly divided into two groups: the control group and the treated group, each group has 30 cases. Patients in the control group received standard treatment for 2 weeks, however, in addition to standard treatment, patients in the treated group also received glutamine 10g tid. Endotoxin (ET), DAO and L/M were compared between the two group. RESULTS: (1) Compared to healthy controls, the level of L/M and DAO was significantly increased in chronic severe hepatitis B patients (t = 2.762, P less than 0.01 or t = 6.326, P less than 0.01). (2) Compared to the control group, ET, DAO and L/M were significantly lower 2 weeks after treatment (F = 11.662, P less than 0.01; F = 12.699, P less than 0.01; F = 19.981, P less than 0.01). CONCLUSION: (1) There is an early intestinal mucosa barrier damage in chronic severe hepatitis B patients. (2) Compared to standard treatment, adding glutamine can reverse intestinal mucosa barrier damage. PMID- 19874692 TI - [Induction of necrosis in the hepatocellular carcinoma HepG2 xenografts treated with SOM230]. AB - OBJECTIVE: To investigate the effects of SOM230, a new somatostatin analogue, on the proliferation of hepatocellular carcinoma (HCC) cell line HepG2 in vitro and in vivo, and explore the mechanism underline the necrosis of tumors. METHODS: MTT, TdT-mediated dUTP nick end labeling assay (TUNEL) and flow cytometric assay were used to measure the effects of SOM230 on the proliferation and apoptosis of HCC HepG2 cells. Nude mice bearing HCC xenografts of the HepG2 cell line were treated with SOM230 (100 microg/kg/d subcutaneously injection) and saline as a control for eight weeks. The mass and percentage of necrotic volume of the HCC xenografts in nude mice were determined. Western blot was used to detect SSTR2 in HCC xenografts. Immunohistochemical method was used to detect the expression sites of SSTR2 and VEGF in HCC xenografts. ELISA was used to detect the levels of TNFalpha. RESULTS: No proliferation and apoptosis of HepG2 cells were induced by SOM230 in vitro (F = 0.16, P more than 0.05). The percentage of necrotic volume in SOM230 were significantly higher than that of control group (73.4%+/-7.0% vs 30.2%+/-14.0%, t = -8.02, P more than 0.01). SSTR2 was expressed in blood sinus of HCC xenografts in nude mice. There was no significance difference in the level of SSTR2 expression between SOM230 group and saline treated group. VEGF expression in xenografts was down-regulated by SOM230 treatment. SOM230 treatment did not affect the level of TNFalpha in HCC xenografts (t = -0.24, P more than 0.05). CONCLUSIONS: SOM230 can induce massive necrosis of HCC xenografts only after the blockage of blood flow through down-regulation of VEGF mediated by SSTR2. PMID- 19874693 TI - [Differentiation of hepatic oval cell into mature hepatocyte induced by hepatic stellate cells]. AB - OBJECTIVE: To investigate the role of hepatic stellate cells in the differentiation of hepatic oval cells into adult hepatocyte. METHODS: The oval cell were cocultured with primary hepatic stellate cells (HSC) in the same well (M-coculture) or separately cultured with HSC by millIcell (S-coculture). Oval cells were cultured alone as control; the expression of adult hepatocyte marker HNF-4alpha, albumin, and oval cell marker AFP, CK-19 in each group were detected by real-time PCR and western-blot. Phenotype changes were observed by transmission electron microscope (TEM); PAS staining was used to detect the quantity of glycogen granule in oval cell. Albumin level in supernatant was detected using ELISA kit. RESULT: (1) The relative level of HNF-4alpha and albumin mRNA expression compared with pre-coculture: M-coculture: HNF-4a: 1.9+/ 0.2, 10.7+/-1.2, 12.0+/-1.3; albumin: 5.7+/-1.6, 110.7+/-13.7, 173.6+/-22.3. S coculture: 1.4+/-0.1, 3.2+/-0.6, 8.9+/-1.4 times; albumin: 2.9+/-1.4, 22.3+/-8.5, 96.3+/-16.3. The relative level of HNF-4a and albumin mRNA expression in coculture group (M- and S-coculture) were higher than control group (LSD-t: 32.98, 10.08, 13.38, 7.96; P less than 0.01); and a higher level of HNF-4a and albumin was found in M-coculture group compared to S-coculture group (LSD-t: 32.98, 25.65; P less than 0.01). The relative level of AFP and CK-19 mRNA expression compared with pre-coculture: M-coculture: 1.1+/-0.2, 0.2+/-0.0, 0.0+/ 0.0; S-coculture group: AFP: 1.0+/-0.2, 0.2+/-0.1, 0.1+/-0.0; CK-19: 0.6+/-0.1, 0.1+/-0.0, 0.0+/-0.0; control group: AFP: 1.0+/-0.1, 1.0+/-0.1, 1.1+/-0.1, CK-19: 1.0+/-0.1, 1.1+/-0.1, 1.0+/-0.1. The relative level of AFP and CK-19 mRNA expression in coculture group (M- and S-coculture) were lower than that in control group (LSD-t: 37.99, 34.50, 13.59, 22.46; P less than 0.01). (2) The albumin secretion was detected in M-coculture: 14 day: (15.30+/-0.09) ng/ml, 21: (20.98+/-0.12) ng/ml; S-coculture: 14 day: (11.41+/-0.13) ng/ml, 21 day:(15.12+/ 0.17) ng/ml. (3) It showed more organelles such as endoplasmic reticulum, mitochondrion and Golgi apparatus in oval cells cocultured with HSC. And cholangiole-like structure appeared between oval cells cocultured with HSC. (4) PAS staining showed glycogen granules could be observed in coculture groups. CONCLUSION: HSC can induce differentiation of oval cell into mature hepatocyte. PMID- 19874694 TI - [Application of total nutrient admixture in acute hepatic failure rats]. AB - OBJECTIVE: To study the therapeutic efficacy of total nutrition admixture (TNA) containing 30.6% BCAA, MCT/LCT, glucose, vitamin, electrolytes in rat with acute hepatic failure (AHF). METHOD: 30 Wistar rats were randomly divided into 4 groups: Normal control, AHF control, Fat-free nutrient admixture group, TNA group. AHF model was induced by D-galactosamine Liver and renal function, nitrogen balance, plasma total protein, albumin, prealbumin, fibronectin, hemoglobin, aminogram, tumor necrosis factor, lymphocyte transformation rate, glucose, blood fat tests etc were determined. RESULTS: The improvement of liver and renal function was better in TNA group than those in other groups. ALT ALP TBil BUN were lower in TNA group than those in other groups. TP, ALB, PA, N balance in TNA group were significantly higher than those in other groups. The spectrum of plasma amino acids of the TNA group was close to the normal and the control group. The TNF in TNA group were significantly higher than that in Fat free nutrient admixture group. The stimulation index in TNA group was significantly higher than that in other groups. The difference of triglyceride in TNA group and normal diet was statistically significant, The difference of cholesterol in TNA group and Fat-free nutrient admixture was statistically significant, The difference of lipid peroxidation in four groups was not statistically significant. CONCLUSION: Nutritional supportive treatment is necessary for AHF. PMID- 19874695 TI - [Role of S6K1 in the induction of SREBP1c in mouse hepatic cell by high glucose stimulation]. AB - OBJECTIVE: To study the role of S6K1 in the induction of SREBP1c in mouse hepatic cell by high glucose stimulation. METHODS: S6K1 shRNA recombinant adenovirus (S6K1Ax) was injected into tail vein of db/db mice and then hepatic triglycerol content was analyzed. Liver specimen were stained with HE. After transfection with S6K1Ax or pU6Ax, mouse hepatic AML12 cells were treated with high glucose, insulin or glucose and insulin, the expression of mSREBP1c was detected by RT PCR. S6K1 protein was detected by Western blot. RESULTS: Hepatic S6K1 protein in db/db mice was inhibited a week after S6K1Ax injection. Compared with the control group, hepatic triglycerol content of S6K1Ax group was decreased (0.65+/-0.02) mmol/L vs (0.56+/-0.01) mmol/L (t = 4.312, P less than 0.01), hepatocyte fat droplet and vaculor generation were also decreased, fatty liver was improved. The mSREBP1c expression in S6K1Ax transfected cells was lower than that in the control cells (0.03+/-0.01 vs 0.06+/-0.01, t = 5.624, P less than 0.01). Compared with the basal state, SREBP1c expression of both groups was increased on the insulin stimulation, S6K1Ax group was 0.06+/-0.02 (t = 8.452, P less than 0.01) and control group was 0.08+/-0.02 (t = 3.591, P less than 0.05). There is no difference between control and S6K1Ax group by glucose addition (P more than 0.05). CONCLUSION: S6K1 acts on fatty synthesis by regulating mSREBP1c expression. PMID- 19874696 TI - [Clinical observation on hepatotoxicity of AIDS patients treated with HAART]. PMID- 19874697 TI - [The effect of Smad4 knockdown on the activated hepatic stellate cells]. PMID- 19874698 TI - [Forecasting of hepatitis C virus CTL epitopes and design of multi-epitopes vaccine]. PMID- 19874699 TI - [Auto-antibodies in hepatitis C virus infection]. PMID- 19874700 TI - [Preliminary research on the mechanism of apoptosis hepatic stellate cells induced by zedoary turmeric oil]. PMID- 19874701 TI - [Effects of sp600125 on acetaldehyde stimulated hepatic stellate cells]. PMID- 19874702 TI - [Dynamics of HBV covalently closed circular DNA: amplification and clearance]. PMID- 19874703 TI - [Regulation of hepatitis B virus replication regulated by HBX protein]. PMID- 19874704 TI - [Molecular study of the hepatic inflammation to fibrosis to cancer axis]. PMID- 19874705 TI - The Hsp90 chaperone machinery: from structure to drug development. AB - Hsp90, an evolutionarily conserved molecular chaperone, is involved in the folding, stabilization, activation, and assembly of a wide range of 'client' proteins, thus playing a central role in many biological processes. Especially, several oncoproteins act as Hsp90 client proteins and tumor cells require higher Hsp90 activity than normal cells to maintain their malignancy. For this reason, Hsp90 has emerged as a promising target for anti-cancer drug development. It is still largely unknown how Hsp90 can recognize structurally unrelated client proteins. However, recent progress in structural studies on Hsp90 and its interaction with various co-chaperones has broadened our knowledge of how the Hsp90 ATPase activity, which is essential for its chaperone function, is regulated and coupled with the conformational changes of Hsp90 dimer. This review focuses on the roles of various Hsp90 co-chaperones in the regulation of the Hsp90 ATPase cycle, as well as in the selection of client proteins. In addition, the current development of Hsp90 inhibitors based on the structural information will be discussed. PMID- 19874706 TI - Heat shock transcription factors and sensory placode development. AB - The heat shock transcription factor (HSF) family consists of at least three members in mammals and regulates expression of heat shock proteins in response to heat shock and proteotoxic stresses. Especially, HSF1 is indispensable for this response. Members of this family are also involved in development of some tissues such as the brain and reproductive organs. However, we did not know the molecular mechanisms that regulate developmental processes. Involvement of HSFs in the sensory development was implicated by the finding that human hereditary cataract is associated with mutations of the HSF4 gene. Analysis of gene-disrupted mice showed that HSF4 and HSF1 are required for the lens and the olfactory epithelium, respectively. Furthermore, a common molecular mechanism that regulates developmental processes was revealed by analyzing roles of HSFs in the two developmentally-related organs. PMID- 19874707 TI - Development and characterization of a fully functional small anti-HER2 antibody. AB - The penetrating of monoclonal antibodies (mAbs) into solid tumor may be hampered by their large size. The antibody mimetics, composed of two complementarity determining regions (CDRs) through a cognate framework region (FR), have been demonstrated to have the capacity to penetrate tumors superior to its parental intact IgG. In this study, we used CDR and FR sequences from the humanized anti HER2 monoclonal antibody trastuzumab to design four antibody mimetics. Then these antibody mimetics were fused to human IgG Fc to generate mimetics-Fc small antibodies. One of the four mimetics-Fc antibodies binds well to HER2 overexpressing SK-BR3 cells and effectively inhibits the binding of trastuzumab. This mimetics-Fc, denoted as HMTI-Fc, was shown to be effective in mediating antibody-dependent cellular cytotoxicity and exhibit an antiproliferative effect in SK-BR3 cells. To our knowledge, the HMTI-Fc antibody shown here is the smallest fully functional antibody and may have a potential for treatment of cancer. PMID- 19874708 TI - The opposite correlation between calcium ion and cyclic-AMP regarding the activation of microsomal triglyceride transfer protein in rat liver. AB - In this study, the effects of Ca(2+) and cyclic adenosine monophosphate (cAMP) on microsomal triglyceride (TG) transfer protein (MTP) activity were investigated in rat liver. MTP activity was high when liver contained low levels of cAMP, which was induced by administration of glucose, or high levels of total Ca(2+) and TG. However, MTP activity increased by high levels of Ca(2+) and TG was reduced in a dose-dependent manner by treatment with dibutyryl-cAMP (db-cAMP), a cAMP analogue. Conversely, when homogenates of liver from normal rats, with low levels of total Ca(2+) and high levels of cAMP, were incubated with thapsigargin, a Ca(2+)-inducer, MTP activity was increased in a dose-dependent manner compared to control. Therefore, our results suggest that high levels of Ca(2+) cause hypertriglyceridemia through the elevation of MTP activity, as opposed to high levels of cAMP, which suppress MTP activity and inhibit hypertriglyceridemia. PMID- 19874709 TI - Radish phospholipid hydroperoxide glutathione peroxidase provides protection against hydroperoxide-mediated injury in mouse 3T3 fibroblasts. AB - Overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) genes has been reported to play an important role in protecting host cells from oxidative injury in several model systems. A radish phospholipid hydroperoxide glutathione peroxidase (RsPHGPx) known to have high catalytic activity was applied to mouse 3T3 fibroblasts to determine the protective effects of PHGPx against oxidative injury triggered by hydroperoxides such as hydrogen peroxide (H(2)O(2)), tert-butyl hydroperoxide (t-BHP) and phosphatidylcholine hydroperoxide (PCOOH). We observed that preincubation of cells with RsPHGPx significantly increased cell viability, reduced levels of malondialdehyde (MDA), inhibited generation of reactive oxygen species (ROS), and maintained natural cell shapes after treatment with H(2)O(2), t-BHP or PCOOH, indicating that the exogenous RsPHGPx can act as an effective hydroperoxide-scavenger and may also protect target cells from oxidative damage. These results suggest the possibility for use of RsPHGPx as a therapeutic protectant. PMID- 19874710 TI - Anti-invasive activity of histone deacetylase inhibitors via the induction of Egr 1 and the modulation of tight junction-related proteins in human hepatocarcinoma cells. AB - The potential anti-metastasis and anti-invasion activities of early growth response gene-1 (Egr-1) and claudin-3, a tight junction (TJ)-related protein, were evaluated using histone deacetylase (HDAC) inhibitors in human hepatocarcinoma cells. The results of wound healing and Transwell assays showed that HDAC inhibitors such as trichostatin A and sodium butyrate inhibited cell migration and invasion. HDAC inhibitors markedly induced Egr-1 expression during the early period, after which expression levels decreased. In addition, the down regulation of snail and type 1 insulin-like growth factor receptor (IGF-1R) in HDAC inhibitor-treated cells induced the upregulation of thrombospondin-1 (TSP 1), E-cadherin and claudin-3. Cells transfected with Egr-1 and claudin-3 siRNA displayed significant blockage of HDAC inhibitor-induced anti-invasive activity. Collectively, these findings indicate that the up-regulation of Egr-1 and claudin 3 are crucial steps in HDAC inhibitor-induced anti-metastasis and anti-invasion. PMID- 19874711 TI - Proteomic analysis of porcine pancreas development. AB - Porcine pancreas development is not well studied at the molecular level despite being a therapeutic resource for diabetic patients. In this study, we investigated expression of lineage markers and performed proteomic analysis. Expression of the early lineage markers Pdx1 and Ptf1a was developmentally conserved between mice and pigs, whereas expression of the islet differentiation marker Pax4 was delayed in porcine compared with murine pancreas development. Proteomic analysis found that expression levels of chymotrypsinogen were downregulated during porcine pancreas development while those of digestive enzymes like lipases, elastase and serine protease were up-regulated. In addition, specific isoforms of protein folding assistants such as protein disulfide isomerase and prefoldin were expressed at specific stages during the maturation of digestive enzymes. Taken together, these results show that development of the porcine pancreas is regulated by a concerted interplay of pancreas lineage marker proteins and other specified proteins, resulting in a functional endocrine and exocrine organ. PMID- 19874712 TI - Lipid accumulation mediated by adiponectin in C2C12 myogenesis. AB - Plasma concentrations of adiponectin have been shown to be decreased in patients with obesity, cardiovascular diseases, hypertension and metabolic syndrome. Recent studies have found that adiponectin reduces lipid accumulation in macrophage foam cells which may impact the development of atherosclerosis. However, it remains unclear whether adiponectin is involved in the process of lipid accumulation during myogenesis. Using C2C12 myoblasts, we investigated the effect of adiponectin on intramyocellular lipid accumulation during myogenesis. The results showed that intracellular lipid accumulation is significantly decreased during C2C12 differentiation, apparently due to increased fatty acid oxidation and decreased fatty acid synthesis during this process. C2C12 cells transiently transfected with adiponectin gene showed reduced lipid accumulation as compared to controls. Further experiments demonstrated that adiponectin can suppress lipid accumulation by increasing fatty acid oxidation during C2C12 myogenesis. PMID- 19874713 TI - Isolation and characterization of a novel short-chain alcohol dehydrogenase gene from Panax ginseng. AB - The cDNA of alcohol dehydrogenase (PgADH) was isolated and characterized from the leaf of Panax ginseng. The cDNA had an open reading frame of 801 bp and a deduced amino acid sequence of 266 residues. The calculated molecular mass of the mature protein is approximately 29 kDa with a predicated isoelectric point of 6.84. Homology analysis revealed that the deduced amino acid of PgADH shares a high degree of homology with the short-chain ADH proteins of other plants. Genomic DNA hybridization analysis indicated that PgADH represents a multi-gene family. The expression of PgADH under various environmental stresses was analyzed at different time points using real-time PCR. ABA, SA and especially JA (80-fold) significantly induced PgADH expression within 24 h of treatment. The positive responses of PgADH to abiotic stimuli suggest that ginseng ADH may protect against hormone-related environmental stresses. PMID- 19874714 TI - Fenofibrate reduces adiposity in pregnant and virgin rats but through different mechanisms. AB - Fenofibrate has been proven to reduce adiposity. Since gestation produces an increase in white adipose tissue (WAT) mass, we comparatively studied this drug effect in virgin and pregnant rats. Fenofibrate reduced lumbar WAT weight in both pregnant and virgin rats. Fenofibrate treatment did not modify plasma free fatty acid (FFA) concentration in virgin rats, it greatly increased it in pregnant animals. Remarkable differences between the two groups were obtained for two proteins related to fatty acid oxidation and esterification and storing. Respectively, the mRNA levels of carnitine palmitoyltransferase I (CPT-I) were increased by the fenofibrate only in the virgin rats and a similar finding was observed for the expression of phosphoenolpyruvate carboxykinase (PEPCK). These findings indicate that fenofibrate reduces adiposity in pregnant and virgin rats through different mechanisms: a) in virgin rats, by promoting fatty acid oxidation; and b) in pregnant rats, by enhancing fatty acid output. PMID- 19874715 TI - Sphingosine 1-phosphate induces vascular endothelial growth factor expression in endothelial cells. AB - Angiogenesis is essential for tumor growth and vascular endothelial cell growth factor (VEGF) plays a key role in this process. Conversely, sphingosine 1 phosphate (S1P) is a biologically active sphingolipid known to play a key role in cancer progression by regulating endothelial cell proliferation and migration. In this study, the authors found that S1P increases the level of VEGF mRNA in human umbilical vein endothelial cells (HUVECs) and immortalized HUVECs (iHUVECs). Additionally, S1P was found to increase VEGF promoter activity in MS-1 mouse pancreatic islet endothelial cells. Furthermore, a pharmacological inhibitory study revealed that G(alpha i/o)-mediated phospholipase C, Akt, Erk, and p38 MAPK signaling are involved in this S1P-induced expression of VEGF. A component of AP1 transcription factor is important for S1P-induced VEGF expression. Taken together, these findings suggest that S1P enhances endothelial cell proliferation and migration by upregulating the expression of VEGF mRNA. PMID- 19874716 TI - Transcriptional activation of pref-1 by E2F1 in 3T3 L1 cells. AB - The E2F gene family appears to regulate the proliferation and differentiation of events that are required for adipogenesis. Pref-1 is a transmembrane protein that inhibits adipocyte differentiation in 3T3-L1 cells. In this study, we found that the expression of pref-1 is regulated by the transcription factor E2F1. The expression of pref-1 and E2F1 was strongly induced in preadipocytes and at the late differentiation stage. Using luciferase reporter assay, ChIP assay and EMSA, we found that the -211/-194 region of the pref-1 promoter is essential for the binding of E2F1 as well as E2F1-dependent transcriptional activation. Knockdown of E2F1 reduced both pref-1 promoter activity and the level of pref-1 mRNA. Taken together, our data suggest that transcriptional activation of pref-1 is stimulated by E2F1 protein in adipocytes. PMID- 19874717 TI - Eggs, embryos and the evolution of imprinting: insights from the platypus genome. AB - Genomic imprinting is widespread in eutherian and marsupial mammals. Although there have been many hypotheses to explain why genomic imprinting evolved in mammals, few have examined how it arose. The host defence hypothesis suggests that imprinting evolved from existing mechanisms within the cell that act to silence foreign DNA elements that insert into the genome. However, the changes to the mammalian genome that accompanied the evolution of imprinting have been hard to define due to the absence of large-scale genomic resources from all extant classes. The recent release of the platypus genome sequence has provided the first opportunity to make comparisons between prototherian (monotreme, which show no signs of imprinting) and therian (marsupial and eutherian, which have imprinting) mammals. We compared the distribution of repeat elements known to attract epigenetic silencing across the genome from monotremes and therian mammals, particularly focusing on the orthologous imprinted regions. Our analyses show that the platypus has significantly fewer repeats of certain classes in the regions of the genome that have become imprinted in therian mammals. The accumulation of repeats, especially long-terminal repeats and DNA elements, in therian imprinted genes and gene clusters therefore appears to be coincident with, and may have been a potential driving force in, the development of mammalian genomic imprinting. Comparative platypus genome analyses of orthologous imprinted regions have provided strong support for the host defence hypothesis to explain the origin of imprinting. PMID- 19874718 TI - Monotreme sex chromosomes--implications for the evolution of amniote sex chromosomes. AB - In vertebrates, a highly conserved pathway of genetic events controls male and female development, to the extent that many genes involved in human sex determination are also involved in fish sex determination. Surprisingly, the master switch to this pathway, which intuitively could be considered the most critical step, is inconsistent between vertebrate taxa. Interspersed in the vertebrate tree there are species that determine sex by environmental cues such as the temperature at which eggs are incubated, and then there are genetic sex determination systems, with male heterogametic species (XY systems) and female heterogametic species (ZW systems), some of which have heteromorphic, and others homomorphic, sex chromosomes. This plasticity of sex-determining switches in vertebrates has made tracking the events of sex chromosome evolution in amniotes a daunting task, but comparative gene mapping is beginning to reveal some striking similarities across even distant taxa. In particular, the recent completion of the platypus genome sequence has completely changed our understanding of when the therian mammal X and Y chromosomes first arose (they are up to 150 million years younger than previously thought) and has also revealed the unexpected insight that sex determination of the amniote ancestor might have been controlled by a bird-like ZW system. PMID- 19874719 TI - Replication asynchrony and differential condensation of X chromosomes in female platypus (Ornithorhynchus anatinus). AB - A common theme in the evolution of sex chromosomes is the massive loss of genes on the sex-specific chromosome (Y or W), leading to a gene imbalance between males (XY) and females (XX) in a male heterogametic species, or between ZZ and ZW in a female heterogametic species. Different mechanisms have evolved to compensate for this difference in dosage of X-borne genes between sexes. In therian mammals, one of the X chromosomes is inactivated, whereas bird dosage compensation is partial and gene-specific. In therian mammals, hallmarks of the inactive X are monoallelic gene expression, late DNA replication and chromatin condensation. Platypuses have five pairs of X chromosomes in females and five X and five Y chromosomes in males. Gene expression analysis suggests a more bird like partial and gene-specific dosage compensation mechanism. We investigated replication timing and chromosome condensation of three of the five X chromosomes in female platypus. Our data suggest asynchronous replication of X-specific regions on X(1), X(3) and X(5) but show significantly different condensation between homologues for X(3) only, and not for X(1) or X(5). We discuss these results in relation to recent gene expression analysis of X-linked genes, which together give us insights into possible mechanisms of dosage compensation in platypus. PMID- 19874720 TI - Analysis of SINE and LINE repeat content of Y chromosomes in the platypus, Ornithorhynchus anatinus. AB - Monotremes feature an extraordinary sex-chromosome system that consists of five X and five Y chromosomes in males. These sex chromosomes share homology with bird sex chromosomes but no homology with the therian X. The genome of a female platypus was recently completed, providing unique insights into sequence and gene content of autosomes and X chromosomes, but no Y-specific sequence has so far been analysed. Here we report the isolation, sequencing and analysis of approximately 700 kb of sequence of the non-recombining regions of Y2, Y3 and Y5, which revealed differences in base composition and repeat content between autosomes and sex chromosomes, and within the sex chromosomes themselves. This provides the first insights into repeat content of Y chromosomes in platypus, which overall show similar patterns of repeat composition to Y chromosomes in other species. Interestingly, we also observed differences between the various Y chromosomes, and in combination with timing and activity patterns we provide an approach that can be used to examine the evolutionary history of the platypus sex chromosome chain. PMID- 19874721 TI - Platypus chain reaction: directional and ordered meiotic pairing of the multiple sex chromosome chain in Ornithorhynchus anatinus. AB - Monotremes are phylogenetically and phenotypically unique animals with an unusually complex sex chromosome system that is composed of ten chromosomes in platypus and nine in echidna. These chromosomes are alternately linked (X1Y1, X2Y2, ...) at meiosis via pseudoautosomal regions and segregate to form spermatozoa containing either X or Y chromosomes. The physical and epigenetic mechanisms involved in pairing and assembly of the complex sex chromosome chain in early meiotic prophase I are completely unknown. We have analysed the pairing dynamics of specific sex chromosome pseudoautosomal regions in platypus spermatocytes during prophase of meiosis I. Our data show a highly coordinated pairing process that begins at the terminal Y5 chromosome and completes with the union of sex chromosomes X1Y1. The consistency of this ordered assembly of the chain is remarkable and raises questions about the mechanisms and factors that regulate the differential pairing of sex chromosomes and how this relates to potential meiotic silencing mechanisms and alternate segregation. PMID- 19874722 TI - Characterisation of ATRX, DMRT1, DMRT7 and WT1 in the platypus (Ornithorhynchus anatinus). AB - One of the most puzzling aspects of monotreme reproductive biology is how they determine sex in the absence of the SRY gene that triggers testis development in most other mammals. Although monotremes share a XX female/XY male sex chromosome system with other mammals, their sex chromosomes show homology to the chicken Z chromosome, including the DMRT1 gene, which is a dosage-dependent sex determination gene in birds. In addition, monotremes feature an extraordinary multiple sex chromosome system. However, no sex determination gene has been identified as yet on any of the five X or five Y chromosomes and there is very little knowledge about the conservation and function of other known genes in the monotreme sex determination and differentiation pathway. We have analysed the expression pattern of four evolutionarily conserved genes that are important at different stages of sexual development in therian mammals. DMRT1 is a conserved sex-determination gene that is upregulated in the male developing gonad in vertebrates, while DMRT7 is a mammal-specific spermatogenesis gene. ATRX, a chromatin remodelling protein, lies on the therian X but there is a testis expressed Y-copy in marsupials. However, in monotremes, the ATRX orthologue is autosomal. WT1 is an evolutionarily conserved gene essential for early gonadal formation in both sexes and later in testis development. We show that these four genes in the adult platypus have the same expression pattern as in other mammals, suggesting that they have a conserved role in sexual development independent of genomic location. PMID- 19874723 TI - Testicular descent, sperm maturation and capacitation. Lessons from our most distant relatives, the monotremes. AB - The present review examines whether monotremes may help to resolve three questions relating to sperm production in mammals: why the testes descend into a scrotum in most mammals, why spermatozoa are infertile when they leave the testes and require a period of maturation in the specific milieu provided by the epididymides, and why ejaculated spermatozoa cannot immediately fertilise an ovum until they undergo capacitation within the female reproductive tract. Comparisons of monotremes with other mammals indicate that there is a need for considerable work on monotremes. It is hypothesised that testicular descent should be related to epididymal differentiation. Spermatozoa and ova from both groups share many of the proteins that are thought to be involved in gamete interaction, and although epididymal sperm maturation is significant it is probably less complex in monotremes than in other mammals. However, the monotreme epididymis is unique in forming spermatozoa into bundles of 100 with greatly enhanced motility compared with individual spermatozoa. Bundle formation involves a highly organised interaction with epididymal proteins, and the bundles persist during incubation in vitro, except in specialised medium, in which spermatozoa separate after 2-3 h incubation. It is suggested that this represents an early form of capacitation. PMID- 19874724 TI - New proteins identified in epididymal fluid from the platypus (Ornithorhynchus anatinus). AB - The platypus epididymal proteome is being studied because epididymal proteins are essential for male fertility in mammals and it is considered that knowledge of the epididymal proteome in an early mammal would be informative in assessing the convergence and divergence of proteins that are important in the function of the mammalian epididymis. Few of the epididymal proteins that have been identified in eutherian mammals were found in platypus caudal epididymal fluid, and the major epididymal proteins in the platypus (PXN-FBPL, SPARC and E-OR20) have never been identified in the epididymis of any other mammal. PMID- 19874725 TI - Directional mapping of DNA nicking in ejaculated and cauda epididymidal spermatozoa of the short-beaked echidna (Tachyglossus aculeatus: Monotremata). AB - Prototherian spermatozoa are unique amongst the Mammalia in terms of their filiform morphology, tandem arrangement of chromosomes and formation of sperm bundles. In the present study, we provide observations of echidna spermatozoa and note that the superstructure of the bundle is engineered around the shape of the individual sperm head and that this in turn may be a consequence of the unusual circumferential and helicoidal condensation of the DNA during spermiogenesis. Frozen-thawed ejaculated echidna spermatozoa were incubated and examined for the presence of non-typical DNA conformation by means of in situ labelling of DNA breaks using Klenow polymerase and via alkaline single-cell comet assays for detection of fragmented DNA. Both techniques successfully revealed the presence of what appeared to be directional DNA nicking, co-localised with the presence of highly sensitive alkali sites along the length of the sperm nucleus. It was not possible to define whether these alternative DNA configurations were associated with a failure of the sperm nucleus to condense appropriately during spermiogenesis or were evidence of DNA fragmentation following post-thaw incubation or a sequential structural chromatin rearrangement necessary for fertilisation. PMID- 19874726 TI - Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals. AB - Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of beta-casein occurred in the monotreme lineage, as opposed to more ancient duplications of alpha-casein in the eutherian lineage, while marsupials possess only single copies of alpha- and beta caseins. Despite this variability, the close proximity of the main alpha- and beta-casein genes in an inverted tail-tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages. PMID- 19874727 TI - Buckle fractures in children: Is urgent treatment necessary? AB - PURPOSE: To determine whether the clinical outcome of buckle fractures in children differs between those treated acutely on the same day of trauma and those treated subacutely, and whether a change in practice patterns based on these data would result in cost savings. METHODS: In this retrospective cohort study-approved by the institutional review board-we reviewed the cases of 341 consecutive patients younger than 18 years of age seen by the pediatric orthopedic clinic for treatment of isolated extremity buckle fractures between July 1, 2004 and August 31, 2007. Time from injury to treatment was used to divide patients into 2 groups: acute (1 day or less; n=155) and subacute treatment (more than 1 day; n=186). Clinical outcome at final orthopedic follow up was recorded for each patient. We defined adverse outcome as fractures requiring manipulation, clinically apparent deformity, or functional impairment. Charge analysis compared differences in management costs for patients with buckle fractures presenting initially to the emergency department (ED) and those seen solely in the orthopedic clinic. RESULTS: No adverse outcomes were identified in either acute or subacute treatment groups. Total clinical visits did not vary (acute, 3.2 vs subacute, 3.1; P=.051). Presence of mild angulation of fractures on radiographs did not differ significantly between acute and subacute management groups at initial presentation (6.5% vs 8.6%; P=.541) or at final follow-up (12.2% vs 12.4%; P=1.0). A cost savings of approximately $3000 could have been realized for each patient referred to the ED who might otherwise have been seen subacutely in the orthopedic clinic. CONCLUSIONS: No adverse clinical outcomes resulted from subacute treatment of stable buckle fractures. Cost and time savings may be realized with subacute management of buckle fractures without affecting clinical outcome. PMID- 19874728 TI - Do OTC remedies relieve cough in acute URIs? AB - Dextromethorphan (DM) for adults and honey for children provide some relief. DM may modestly decrease cough in adults compared with placebo. The data supporting zinc for the common cold are mixed. Antihistamines, antihistamine-decongestant combinations, and guaifenesin do not provide greater relief than placebo in adults. In children, antihistamines, decongestants, DM, or combinations of them do not relieve cough better than placebo. Honey may modestly decrease frequency and severity of cough compared with DM or no treatment. PMID- 19874729 TI - Liver disease: early signs you may be missing. PMID- 19874730 TI - 3 alternatives to standard varicose vein treatment. AB - Discuss minimally invasive procedures with patients considering surgery for treatment of chronic venous insufficiency. Thermal ablation, in particular, has higher success rates than vein stripping. Consider endovenous chemical ablation for treatment of tortuous saphenous tributary varicosities that cannot be treated with thermal ablation. Foamed sclerosant, injected under ultrasound guidance, allows for direct visualization and has equivalent efficacy rates when compared to venous stripping. Pregnancy, active deep vein thrombosis, poor health with limited mobility, and severe peripheral vascular disease are contraindications for both thermal and chemical ablation. PMID- 19874731 TI - Stop shingles in its tracks. AB - Initiate antiviral treatment as soon as possible; rapid resolution of acute pain and reduction in the development of postherpetic neuralgia (PHN) are most likely when therapy is started within 72 hours of the outbreak. Discuss herpes zoster (HZ) vaccination with healthy patients 60 years of age and older during their first office visit; the vaccine markedly reduces the incidence of HZ and PHN. Do not prescribe tricyclic antidepressants or corticosteroids in the acute phase of HZ. PMID- 19874732 TI - Screening adults for depression in primary care: A position statement of the American College of Preventive Medicine. AB - The American College of Preventive Medicine (ACPM) maintains that primary care providers should screen all adults for depression and that all primary care providers should have systems in place, either within the primary care setting itself or through collaborations with mental health professionals, to ensure the accurate diagnosis and treatment of this condition. The earliest and best opportunities to identify depression are in the clinics of primary care providers. Thus, the ACPM supports the recommendations of the US Preventive Services Task Force (USPSTF), and further suggests that all primary care practices should have such systems of care in place. PMID- 19874733 TI - Failure to thrive. PMID- 19874734 TI - Pain in abdomen and shoulder. AB - A 26-year-old man came into the emergency department for treatment of vomiting, and pain in his abdomen and right shoulder. His vital signs were normal, with the exception of his heart rate, which was 109 bpm. His oxygen saturation was 96% on room air. The patient, a smoker, did not complain of any difficulty breathing, despite having diminished breath sounds over the left lung fields and absent breath sounds over the right. The rest of the exam was normal. The patient's initial blood work was within normal limits. We ordered a chest x-ray and a chest computed tomography (CT) scan to further assess his decreased breath sounds. PMID- 19874735 TI - Can nonantidepressants help treat depression? PMID- 19874736 TI - Which complementary therapies can help patients with PMS? PMID- 19874737 TI - Frequently asked questions in the evaluation and management of overactive bladder. PMID- 19874738 TI - Step-to-step reproducibility and asymmetry to study gait auto-optimization in healthy and cerebral palsied subjects. AB - OBJECTIVE: The purpose of our study was to compare plantar pressure asymmetry and step-to-step reproducibility in both able-bodied persons and two groups of hemiplegics. The relevance of the research was to determine the efficiency of asymmetry and reproducibility as indexes for diagnosis and rehabilitation processes. MATERIAL AND METHOD: This study comprised 31 healthy young subjects and 20 young subjects suffering from cerebral palsy hemiplegia assigned to two groups of 10 subjects according to the severity of their musculoskeletal disorders. The peaks of plantar pressure and the time to peak pressure were recorded with an in-shoe measurement system. The intra-individual coefficient of variability was calculated to indicate the consistency of plantar pressure during walking and to define gait stability. The effect size was computed to quantify the asymmetry and measurements were conducted at eight footprint locations. RESULTS: Results indicated few differences in step-to-step reproducibility between the healthy group and the less spastic group while the most affected group showed a more asymmetrical and unstable gait. CONCLUSION: From the concept of self-optimisation and depending on the neuromotor disorders the organism could make priorities based on pain, mobility, stability or energy expenditure to develop the best gait auto-optimisation. PMID- 19874739 TI - Neuropsychological disorders induced by cerebellar damage. AB - INTRODUCTION: Motor coordination disorders caused by cerebellar dysfunction are well known. However, the less known cerebellar neuropsychological disorders also merit attention, since they occur more frequently than one might imagine. CASE REPORT: We describe a 66-year-old patient with severe cerebellar damage caused by hemorrhagic stroke and associated with cognitive impairments (including impaired executive function, reasoning and judgment). A review of the literature on these neuropsychological disorders revealed a set of clinical, anatomical and functional imaging arguments that prompted us to broaden our vision of the cerebellum's role by acknowledging the presence of a cognitive component as well as the well-known motility component. In fact, there is good evidence of altered executive function (including mental flexibility, scheduling capacities and verbal working memory) in cerebellar patients. Visuospatial capacities are also affected, with disorders of visual memory and construction abilities having been reported. In terms of language, we noted reports of hypospontaneity and agrammatism with syntax problems. Memory (especially verbal memory), learning (both associative and procedural), judgment and reasoning also seem to be affected. In terms of emotion, various types of abnormal behavior and psychiatric disorders have been described and range from depression to true psychoses. Even though these data are controversial and must be confirmed, they prompt us to reconsider and deepen our understanding of the cerebellum's role and the functioning and improve our approach to (and management of) patients with cerebellar damage. PMID- 19874750 TI - Forming a consortium to promote pediatric cardiac care in a developing country. PMID- 19874752 TI - Databases and diagnosis of obesity: pitfalls and potential of using ICD-9 codes. PMID- 19874751 TI - The tip of the iceberg: the prevalence of functional gastrointestinal diseases in children. PMID- 19874753 TI - ALTEs: still a puzzle after all these years. PMID- 19874754 TI - Establishing a translational science for autistic spectrum disorders for children and their families: optimizing function, participation, and well-being. PMID- 19874760 TI - Obesity is related to multiple functional abdominal diseases. AB - Analysis of the body mass index of pediatric patients with gastrointestinal complaints as a whole and by disease subgroup revealed a greater percentage of obese patients with constipation, gastroesophageal reflux, irritable bowel syndrome, encopresis, and functional abdominal pain compared with local and New Jersey control populations. PMID- 19874761 TI - Use of antibiotics in children hospitalized with community-acquired, laboratory confirmed influenza. AB - Many children with influenza are treated with antibiotics. In this report, we describe the rate and indications for antibacterial use in children hospitalized with influenza. A total of 333 of 729 (46%) patients received >2 days of treatment with antibacterial medications, of whom 36% did not have an apparent indication for therapy. PMID- 19874762 TI - Mannose-binding lectin deficiency in a child with recurrent infections. AB - We describe an 11 month old girl with mannose-binding lectin deficiency who presented with recurrent infections. Her mother and brother also were affected. Mannose-binding deficiency is common, and we suggest that testing for it should be included in the evaluation of children with increased susceptibility to infection. PMID- 19874763 TI - Are breast-fed infants more resilient? Feeding method and cortisol in infants. AB - The effect of feeding method on stress hormone levels in infants is unknown. We studied infants from birth to 1 year and found salivary cortisol 40% higher in breast-fed infants compared with formula-fed infants. The higher cortisol levels among breast-fed children may be involved in the analgesic effect of breastfeeding. PMID- 19874764 TI - High and low glycemic index mixed meals and blood glucose in youth with type 2 diabetes or impaired glucose tolerance. AB - This cross-over pilot study tested blood glucose response to low and high glycemic index meals in 12 obese youth with type 2 diabetes or impaired glucose tolerance. Participants demonstrated significantly lower mean daytime blood glucose and a trend toward lower variability, suggesting a clinically relevant impact of reducing glycemic index. PMID- 19874765 TI - Acquired left-sided pulmonary vein stenosis in an extremely premature infant: a new entity? PMID- 19874766 TI - Esophageal perforation: a complication of nasogastric tube placement in premature infants. PMID- 19874767 TI - Evidence not persuasive for recommending a combination of ibuprofen and acetaminophen for feverish children. PMID- 19874768 TI - Ondansetron reduces vomiting in children with acute gastroenteritis. PMID- 19874770 TI - Nicotine nasal spray neither effective nor well-tolerated by adolescent smokers. PMID- 19874772 TI - Clinical dehydration scale appears valid, but its impact on clinical outcomes is not clear. PMID- 19874771 TI - Continuous glucose monitoring study does not demonstrate benefit in children and adolescents. PMID- 19874774 TI - Improbable blood lead concentration-IQ relationships. PMID- 19874775 TI - Correction. PMID- 19874776 TI - Data suggest visual assessment of jaundice in newborns is helpful. PMID- 19874777 TI - Ketoconazole treatment for Cushing syndrome in McCune-Albright syndrome. PMID- 19874779 TI - Sun proteins enlighten nuclear movement in development. AB - Regulation of nuclear movement is a critical event in neurogenesis and neuronal migration during brain development. In this issue of Neuron, Zhang et al. identify a role for SUN and the KASH-domain-containing nuclear membrane proteins as the long-sought linker between microtubules and the nucleus during brain development. PMID- 19874780 TI - Guidance receptors find their places in the axonal order. AB - In this issue of Neuron, Katsuki and colleagues show that cell-autonomous mechanisms divide Drosophila axons into proximal and distal compartments. Axon guidance receptors selectively localize to one compartment. A diffusion barrier exists near the compartment boundary, suggesting that it may have properties like those of the axon initial segment in mammalian neurons. PMID- 19874781 TI - Go with the flow -- but only in one direction. AB - Retinotopic maps form prior to the development of vision, when retinal waves serve as a robust source of correlated neural activity. Two recent studies provide critical insights into the features of retinal waves that may be instructive for the formation of retinotopic maps. PMID- 19874782 TI - History matters: illuminating metaplasticity in the developing brain. AB - Metaplasticity refers to an activity-dependent regulation of the plastic state of neurons. In this issue of Neuron, Dunfield and Haas demonstrate that in intact developing brain circuits, specific patterns of visual stimulation drive functional plasticity of individual neurons with variable outcomes, predisposed by time-averaged postsynaptic activity recent to visual training. PMID- 19874783 TI - A stretch from the periphery helps brain clocks feel the daily heat. AB - In this issue of Neuron, Sehadova et al. show that synchronization of circadian clocks in the brains of Drosophila by daily temperature changes requires chordotonal organs, mechanosensory structures that function as stretch receptors in insects. This is strikingly different from the more direct path by which brain clocks perceive light. PMID- 19874784 TI - The way biomedical research is organized has dramatically changed over the past half-century: are the changes for the better? AB - Biomedical research in today's universities is usually carried out by groups consisting of a leader and 5-20 or so trainees. This is in sharp contrast with past generations, when research was usually done by individuals or small partnerships of two or three who thought up their own ideas and carried them out themselves. Group leaders today spend their time in an office, on a wide variety of administrative tasks, and have little or no time left for work at the bench. I recommend that leaders try to change the system by forming smaller groups and insisting on reserving their own time at the bench. I suggest that trainees, before beginning their research, look for laboratories where groups are small and independent, with leaders engaged actively in research. PMID- 19874785 TI - Combined intrinsic and extrinsic neuronal mechanisms facilitate bridging axonal regeneration one year after spinal cord injury. AB - Despite advances in promoting axonal regeneration after acute spinal cord injury (SCI), elicitation of bridging axon regeneration after chronic SCI remains a formidable challenge. We report that combinatorial therapies administered 6 weeks, and as long as 15 months, after SCI promote axonal regeneration into and beyond a midcervical lesion site. Provision of peripheral nerve conditioning lesions, grafts of marrow stromal cells, and establishment of NT-3 gradients supports bridging regeneration. Controls receiving partial components of the full combination fail to exhibit bridging. Notably, intraneuronal molecular mechanisms recruited by delayed therapies mirror those of acute injury, including activation of transcriptional activators and regeneration-associated genes. Collectively, these findings provide evidence that regeneration is achievable at unprecedented postinjury time points. PMID- 19874787 TI - Intra-axonal patterning: intrinsic compartmentalization of the axonal membrane in Drosophila neurons. AB - In the developing nervous system, distribution of membrane molecules, particularly axon guidance receptors, is often restricted to specific segments of axons. Such localization of membrane molecules can be important for the formation and function of neural networks; however, how this patterning within axons is achieved remains elusive. Here we show that Drosophila neurons in culture establish intra-axonal patterns in a cell-autonomous manner; several membrane molecules localize to either proximal or distal axon segments without cell-cell contacts. This distinct patterning of membrane proteins is not explained by a simple temporal control of expression, and likely involves spatially controlled vesicular targeting or retrieval. Mobility of transmembrane molecules is restricted at the boundary of intra-axonal segments, indicating that the axonal membrane is compartmentalized by a barrier mechanism. We propose that this intra axonal compartmentalization is an intrinsic property of Drosophila neurons that provides a basis for the structural and functional development of the nervous system. PMID- 19874786 TI - SUN1/2 and Syne/Nesprin-1/2 complexes connect centrosome to the nucleus during neurogenesis and neuronal migration in mice. AB - Nuclear movement is critical during neurogenesis and neuronal migration, which are fundamental for mammalian brain development. Although dynein, Lis1, and other cytoplasmic proteins are known for their roles in connecting microtubules to the nucleus during interkinetic nuclear migration (INM) and nucleokinesis, the factors connecting dynein/Lis1 to the nuclear envelope (NE) remain to be determined. We report here that the SUN-domain proteins SUN1 and SUN2 and the KASH-domain proteins Syne-1/Nesprin-1 and Syne-2/Nesprin-2 play critical roles in neurogenesis and neuronal migration in mice. We show that SUN1 and SUN2 redundantly form complexes with Syne-2 to mediate the centrosome-nucleus coupling during both INM and radial neuronal migration in the cerebral cortex. Syne-2 is connected to the centrosome through interactions with both dynein/dynactin and kinesin complexes. Syne-2 mutants also display severe defects in learning and memory. These results fill an important gap in our understanding of the mechanism of nuclear movement during brain development. PMID- 19874788 TI - Spatial-temporal patterns of retinal waves underlying activity-dependent refinement of retinofugal projections. AB - During development, retinal axons project coarsely within their visual targets before refining to form organized synaptic connections. Spontaneous retinal activity, in the form of acetylcholine-driven retinal waves, is proposed to be necessary for establishing these projection patterns. In particular, both axonal terminations of retinal ganglion cells (RGCs) and the size of receptive fields of target neurons are larger in mice that lack the beta2 subunit of the nicotinic acetylcholine receptor (beta2KO). Here, using a large-scale, high-density multielectrode array to record activity from hundreds of RGCs simultaneously, we present analysis of early postnatal retinal activity from both wild-type (WT) and beta2KO retinas. We find that beta2KO retinas have correlated patterns of activity, but many aspects of these patterns differ from those of WT retina. Quantitative analysis suggests that wave directionality, coupled with short-range correlated bursting patterns of RGCs, work together to refine retinofugal projections. PMID- 19874789 TI - Dual palmitoylation of NR2 subunits regulates NMDA receptor trafficking. AB - Modification of NMDA receptor function and trafficking contributes to the regulation of synaptic transmission and is important for several forms of synaptic plasticity. Here, we report that NMDA receptor subunits NR2A and NR2B have two distinct clusters of palmitoylation sites in their C-terminal region. Palmitoylation within the first cluster on a membrane-proximal region increases tyrosine phosphorylation of tyrosine-based internalization motifs by Src family protein tyrosine kinases, leading to enhanced stable surface expression of NMDA receptors. In addition, palmitoylation of these sites regulates constitutive internalization of the NMDA receptor in developing neurons. In marked contrast, palmitoylation of the second cluster in the middle of C terminus by distinct palmitoyl transferases causes receptors to accumulate in the Golgi apparatus and reduces receptor surface expression. These data suggest that regulated palmitoylation of NR2 subunits differentially modulates receptor trafficking and might be important for NMDA-receptor-dependent synaptic plasticity. PMID- 19874790 TI - ELKS2alpha/CAST deletion selectively increases neurotransmitter release at inhibitory synapses. AB - The presynaptic active zone is composed of a protein network that contains ELKS2alpha (a.k.a. CAST) as a central component. Here we demonstrate that in mice, deletion of ELKS2alpha caused a large increase in inhibitory, but not excitatory, neurotransmitter release, and potentiated the size, but not the properties, of the readily-releasable pool of vesicles at inhibitory synapses. Quantitative electron microscopy revealed that the ELKS2alpha deletion did not change the number of docked vesicles or other ultrastructural parameters of synapses, except for a small decrease in synaptic vesicle numbers. The ELKS2alpha deletion did, however, alter the excitatory/inhibitory balance and exploratory behaviors, possibly as a result of the increased synaptic inhibition. Thus, as opposed to previous studies indicating that ELKS2alpha is essential for mediating neurotransmitter release, our results suggest that ELKS2alpha normally restricts release and limits the size of the readily-releasable pool of synaptic vesicles at the active zone of inhibitory synapses. PMID- 19874791 TI - Metaplasticity governs natural experience-driven plasticity of nascent embryonic brain circuits. AB - During embryogenesis, brain neurons receiving the same sensory input may undergo potentiation or depression. While the origin of variable plasticity in vivo is unknown, it plays a key role in shaping dynamic neural circuit refinement. Here, we investigate effects of natural visual stimuli on neuronal firing within the intact, awake, developing brain using calcium imaging of 100 s of central neurons in the Xenopus retinotectal system. We find that specific patterns of visual stimuli shift population responses toward either potentiation or depression in an N-methyl-D-aspartate receptor (NMDA-R)-dependent manner. In agreement with Bienenstock-Cooper-Munro metaplasticity, our results show that functional potentiation or depression can be predicted by individual neurons' specific receptive field properties and historic firing rates. Interestingly, this activity-dependent metaplasticity is itself NMDA-R dependent. Furthermore, network analysis reveals increased correlated firing of neurons that undergo potentiation. These findings implicate metaplasticity as a natural property regulating experience-dependent refinement of nascent embryonic brain circuits. PMID- 19874792 TI - Temperature entrainment of Drosophila's circadian clock involves the gene nocte and signaling from peripheral sensory tissues to the brain. AB - Circadian clocks are synchronized by the natural day/night and temperature cycles. Our previous work demonstrated that synchronization by temperature is a tissue autonomous process, similar to synchronization by light. We show here that this is indeed the case, with the important exception of the brain. Using luciferase imaging we demonstrate that brain clock neurons depend on signals from peripheral tissues in order to be synchronized by temperature. Reducing the function of the gene nocte in chordotonal organs changes their structure and function and dramatically interferes with temperature synchronization of behavioral activity. Other mutants known to affect the function of these sensory organs also interfere with temperature synchronization, demonstrating the importance of nocte in this process and identifying the chordotonal organs as relevant sensory structures. Our work reveals surprising and important mechanistic differences between light- and temperature-synchronization and advances our understanding of how clock resetting is accomplished in nature. PMID- 19874794 TI - Frequency-band coupling in surface EEG reflects spiking activity in monkey visual cortex. AB - Although the electroencephalogram (EEG) is widely used in research and clinical settings, its link to the underlying neural activity during sensory processing remains poorly understood. To investigate this, we made simultaneous recordings of surface EEG, intracortical local field potential, and multiunit activity (MUA) in the alert monkey visual cortex during presentation of natural movies. Using a general linear model, we show that in single trials, EEG power in the gamma band (30-100 Hz) and phase in delta band (2-4 Hz) are significant predictors of the MUA response. Specifically, we found that the MUA response was strongest only when increases in EEG gamma power occurred during the negative-going phase of the delta wave, thus revealing a frequency-band coupling mechanism that can be exploited to infer population spiking activity. This finding may open up a new dimension in the use and interpretation of EEG in normal and pathological conditions. PMID- 19874793 TI - Theta oscillations provide temporal windows for local circuit computation in the entorhinal-hippocampal loop. AB - Theta oscillations are believed to play an important role in the coordination of neuronal firing in the entorhinal (EC)-hippocampal system but the underlying mechanisms are not known. We simultaneously recorded from neurons in multiple regions of the EC-hippocampal loop and examined their temporal relationships. Theta-coordinated synchronous spiking of EC neuronal populations predicted the timing of current sinks in target layers in the hippocampus. However, the temporal delays between population activities in successive anatomical stages were longer (typically by a half theta cycle) than expected from axon conduction velocities and passive synaptic integration of feed-forward excitatory inputs. We hypothesize that the temporal windows set by the theta cycles allow for local circuit interactions and thus a considerable degree of computational independence in subdivisions of the EC-hippocampal loop. PMID- 19874795 TI - Factors contributing to anaemia after uncomplicated Plasmodiumfalciparum malaria in children. AB - The factors contributing to anaemia in falciparum malaria were characterized in 1261 prospectively studied children in an endemic area of southwestern Nigeria. Of these, 487 (39%) presented with anaemia (haematocrit <30%). The following were found to be independent risk factors for anaemia at presentation: age <5 years, history of illness >3 days before presentation, presence of fever, a palpable liver, >parasitaemia 10,000/microl blood, and gametocytaemia. The mean maximum fractional fall in haematocrit (FFH) after treatment was 13.8% (95% confidence interval [CI] 13-14.6) of the baseline value. This occurred 3 days after treatment began and correlated positively with enrolment haematocrit. In children whose haematocrit was >30% at enrolment, the following were found to be independent risk factors associated with subsequent development of anaemia during follow-up: age <5 years and parasitaemia > or =100,000 parasites/microl. Haematological recovery was usually complete by 4-5 weeks, but was slower in children who were anaemic at enrolment and in those with recrudescence of their infections. Half of the children with recrudescence were still anaemic at 4 weeks. These findings have implications for the control of the burden of malarial anaemia in children in sub-Saharan African countries. PMID- 19874796 TI - Plasma levels of chemokines during leprosy specific treatment. AB - Leprosy, whose etiologic agent is Mycobacterium leprae, is an illness of ample clinical and immunopathological spectrum. Although chemokines seem to be involved in the immunopathogenesis of leprosis, few studies have been carried out to unveil the potential of chemokines as biological markers of the disease. The purpose of this study was to investigate the value of measuring CCL2, CCL3, CCL11 and CCL24 in plasma of patients with leprosy (LE) at different stages of multi drug therapy (MDT). Chemokines were measured by ELISA in plasma of 30 non infected individuals (NI) and 33 LE patients before and at different stages of treatment. The plasma concentration of CCL11 (p<0.01) and CCL24 (p<0.05) was increased in LE patients before treatment when compared to NI individuals. The plasma concentration of CCL24 decreased after MDT (p<0.05). No differences were observed in the concentration of CCL2 and CCL3 in plasma of NI and LE individuals. The elevated levels of CCL11 and CCL24 in plasma of patients with LE suggest that these chemokines may play a role in disease pathogenesis. Moreover, the decrease of CCL24 after treatment suggests that this chemokine might be useful as a biomarker of response to MDT in patients with leprosy. PMID- 19874797 TI - Improving discrimination of outer membrane proteins by fusing different forms of pseudo amino acid composition. AB - Integral membrane proteins are central to many cellular processes and constitute approximately 50% of potential targets for novel drugs. However, the number of outer membrane proteins (OMPs) present in the public structure database is very limited due to the difficulties in determining structure with experimental methods. Therefore, discriminating OMPs from non-OMPs with computational methods is of medical importance as well as genome sequencing necessity. In this study, some sequence-derived structural and physicochemical features of proteins were incorporated with amino acid composition to discriminate OMPs from non-OMPs using support vector machines. The discrimination performance of the proposed method is evaluated on a benchmark dataset of 208 OMPs, 673 globular proteins, and 206 alpha-helical membrane proteins. A high overall accuracy of 97.8% was observed in the 5-fold cross-validation test. In addition, the current method distinguished OMPs from globular proteins and alpha-helical membrane proteins with overall accuracies of 98.2 and 96.4%, respectively. The prediction performance is superior to the state-of-the-art methods in the literature. It is anticipated that the current method might be a powerful tool for the discrimination of OMPs. PMID- 19874798 TI - Probing mechanisms for enzymatic activity enhancement of organophosphorus hydrolase in functionalized mesoporous silica. AB - We have previously reported that organophosphorus hydrolase (OPH) can be spontaneously entrapped in functionalized mesoporous silica (FMS) with HOOC- as the functional groups and the entrapped OPH in HOOC-FMS showed enhanced enzyme specific activity. This work is to study the mechanisms that why OPH entrapped in FMS displayed the enhanced activity in views of OPH-FMS interactions using spectroscopic methods. The circular dichroism (CD) spectra show that, comparing to the secondary structure of OPH free in solution, OPH in HOOC-FMS displayed increased alpha-helix/beta-strand transition of OPH with increased OPH loading density. The fluorescence emission spectra of Trp residues were used to assess the tertiary structural changes of the enzyme. There was a 42% increase in fluorescence. This is in agreement with the fact that the fluorescence intensity of OPH was increased accompanying with the increased OPH activity when decreasing urea concentrations in solution. The steady-state anisotropy was increased after OPH entrapping in HOOC-FMS comparing to the free OPH in solution, indicating that protein mobility was reduced upon entrapment. The solvent accessibility of Trp residues of OPH was probed by using acrylamide as a collisional quencher. Trp residues of OPH-FMS had less solvent exposure comparing with free OPH in solution due to its electrostatical binding to HOOC-FMS thereby displaying the increased fluorescence intensity. These results suggest the interactions of OPH with HOOC FMS resulted in the protein immobilization and a favorable conformational change for OPH in the crowded confinement space and accordingly the enhanced activity. PMID- 19874799 TI - An aggregate-prone mutant of human glyceraldehyde-3-phosphate dehydrogenase augments oxidative stress-induced cell death in SH-SY5Y cells. AB - Glycerladehyde-3-phosphate dehydrogenase (GAPDH), a classic glycolytic enzyme, also has a role in mediating cell death under oxidative stress. Our previous reports suggest that oxidative stress-induced GAPDH aggregate formation is, at least in part, a mechanism to account for the death signaling. Here we show that substitution of cysteine for serine-284 of human GAPDH (S284C-GAPDH) leads to aggregate-prone GAPDH, and that its expression in SH-SY5Y human neuroblastoma results in greater dopamine-induced cell death than expression of wild type GAPDH. Treatment of purified recombinant S284C-GAPDH in vitro with the nitric oxide donor NOR3 led to greater aggregation than wild type-GAPDH. Several lines of structural analysis revealed that S284C-GAPDH was amyloidogenic. Overexpression of doxycycline-inducible S284C-GAPDH in SH-SY5Y cells accelerated dopamine treatment-induced death and increased formation of GAPDH aggregates, compared to cells expressing wild type-GAPDH. These results suggest that aggregate-prone mutations of GAPDH such as S284C-GAPDH may confer risk of oxidative stress-induced cell death. PMID- 19874800 TI - IL-8 production by macrophages is synergistically enhanced when cigarette smoke is combined with TNF-alpha. AB - Macrophages are key inflammatory cells in chronic obstructive pulmonary disease (COPD). The pathophysiology of cigarette smoke-induced lung emphysema is complex but there is a clear role for reactive oxygen species (ROS, such as peroxynitrite), tumor necrosis factor (TNF-alpha) and interleukin (IL)-8. We investigated whether TNF-alpha or cigarette smoke medium (CSM) alone or in combination induces the production of IL-8 by human macrophages or monocyte lymphoma U937. CSM and TNF-alpha induce a dose- and time-dependent increase in IL 8 production. Interestingly, when sub-threshold concentrations of CSM and TNF alpha were co-incubated, a 1500% increase in IL-8 production was observed compared to either of the compounds alone. Similar results were obtained with TNF alpha and the peroxynitrite donor SIN-1. Moreover, the overproduction of IL-8 was associated with an enhanced increase in the translocation of NF-kappaB and an enhanced decrease in glutathione levels. Preincubation of the cells with antioxidants, such as N-acetyl-L-cysteine (NAC), prevented the overproduction of IL-8 and activation of NF-kappaB. In conclusion, CSM exposure of macrophages up regulates the expression and the production of IL-8 via reactive oxygen species and NF-kappaB activation. Moreover, CSM dramatically enhances the production of IL-8 in combination with TNF-alpha. Based upon the strong synergistic action, a combination therapy directed against ROS and TNF-alpha could be a new approach to stop the progression in lung damage during emphysema. PMID- 19874801 TI - Targets and effectors of the cellular response to aurora kinase inhibitor MK-0457 (VX-680) in imatinib sensitive and resistant chronic myelogenous leukemia. AB - MK-0457 inhibits aurora, BCR-ABL and other kinases and may be clinically active in imatinib resistant leukemia. To define mediators of MK-0457 responsiveness, kinase inhibitory profiles were examined in multiple cell models of imatinib sensitive and resistant disease. Aurora and BCR-ABL kinase inhibition were consistently measured at 20-100 nM and 2-10 microM MK-0457, respectively, but expression of T315I-BCR-ABL and overexpression of Lyn kinase reduced MK-0457 sensitivity. Aurora kinase inhibition was associated with cell cycle restriction and p53 induction and p53-null cells were far less responsive to MK-0457, requiring BCR-ABL inhibitory concentrations for apoptotic activity. In wild-type p53 expressing CML cells MK-0457 sensitivity was modulation by alterations in p53 levels through HDM-2 inhibition and gene silencing. MK-0457 suppressed aurora kinase activity and induced apoptosis in imatinib resistant clinical specimens expressing T315I and other BCR-ABL mutations without effecting BCR-ABL kinase activity. Together, these results suggest that MK-0457 apoptotic activity in CML cells is primarily associated with aurora kinase inhibition but can be altered by multiple molecular changes associated with disease progression or acquisition of imatinib resistance. PMID- 19874802 TI - Effects of cisplatin on matrix metalloproteinase-2 in transformed thyroid cells. AB - We investigated the effects of cisplatin (cisPt) on matrix metalloproteinase-2 (MMP-2) gelatinolitic activity in transformed PC E1Araf rat thyroid cells. Cells incubated with increasing cisPt concentrations showed dose- and time-dependent decrease of the MMP-2 protein and activity. CisPt provoked the translocation from the cytosol to the plasma membrane of atypical protein kinase C-zeta (PKC-zeta) and the activation of PKB/AKT. The effect of cisPt on MMP-2 was dependent on PKC zeta activation since it was potentiated by a myristoylated PKC-zeta pseudo substrate peptide or by PKC-zeta down-regulation by siRNA. Moreover, MMP-2 activity modulation by cisPt was also dependent on PKB/AKT activation since it was decreased by PKB/AKT down-regulation by siRNA or by pharmacological inhibition of PI3K, thus indicating the importance of the balance of PKB/AKT and PKC-zeta in regulating the cisPt effect on MMP-2 activity. The PC E1Araf cells displayed a migratory capacity that was blocked by MMP-2 down-regulation using siRNA or pharmacological inhibition. The inhibition of cell migration was also obtained with cisPt; in cisPt-treated cells the administration of MMP-2 active protein was able to restore cell migration capacity. In conclusion, the decrease of MMP-2 secretion after cisPt was allowed by PKB/AKT and counteracted by PKC zeta; the cisPt-provoked inhibition of MMP-2 secretion ended in reduction of cell migration. PMID- 19874803 TI - How do infants perceive scrambled face?: A near-infrared spectroscopic study. AB - Using near-infrared spectroscopy (NIRS), we recorded changes of oxy-Hb, deoxy-Hb, and total-Hb in 7- to 8-month-old infants' and adults' brains in response to canonical face and scrambled face stimuli. Using a newly developed probe for NIRS recording, which was light and soft enough to be tolerated by infants, we were able to acquire data from the very young even in the awake state. Total-Hb in response to a canonical face stimulus was greater than for scrambled face stimuli only in the right hemisphere in infants. This indicates the presence of right hemisphere dominance of brain activity in response to face images in 7- to 8 month-old infants. In adults, oxy-Hb and total-Hb were significantly increased from baseline only for the canonical face in the right hemisphere. There were greater numbers of channels showing significantly increased activity for the canonical face in the right than in the left hemisphere. These data indicate that the right hemisphere is more dominant for canonical face perception in both infants and adults. However, overall, the increase of total-Hb and oxy-Hb in adults was modest compared to infants. Although the reason for the difference between infants and adults is unclear, in addition to developmental changes influencing face perception, some methodological problems may be present. Thus, because we recorded NIRS signals in infants and adults using the same method, anatomical and physiological problems might affect the results to some degree. Although comparing the results between infants and adults is not simple, the present study is the first to indicate how 7- to 8-month-old infants perceive scrambled face stimuli and to compare such results with those of adults in order to understand developmental changes in face perception. PMID- 19874805 TI - Postnatal development of neuronal responses to frequency-modulated tones in chinchilla auditory cortex. AB - Responses to cortical neurons to frequency-modulated (FM) stimuli have been described in various adult animal models. Here, we ask whether FM coding at the cortical level is innate or if it is influenced by postnatal environmental experience. We report on the FM response properties of neurons in core auditory cortex of newborn (P3), 1-month-old (P28) and adult (>1-year-old) anesthetized chinchillas (Chinchilla laniger). Upward and downward linear FM sweeps spanning frequencies from 0.1 to 20 kHz were presented monaurally at speeds of 0.05 to 0.82 kHz/ms. Results indicated that neurons in neonatal pups were responsive to FM stimulation. While we observed a developmental increase in the selectivity of units for FM sweep direction (p<0.01, one-way ANOVA), selectivity for sweep speed appeared to be established early in development. Chinchilla pup neurons also demonstrated single-peak (single dominant response during FM sweep presentation) and multi-peak (multiple distinct responses during FM sweep) temporal response patterns to FM stimuli similar to those observed in adults. A developmental increase in the proportion of multi-peak units closely paralleled a previously reported increase in the complexity of pure tone receptive fields. We suggest that units in core auditory cortex of the chinchilla are not uniquely activated by FM sounds but that FM responses are largely predictable based on how changing frequency stimuli interact with the tonal receptive fields of neurons in the auditory cortex. PMID- 19874806 TI - Epigenetic changes in therapy-related MDS/AML. AB - Therapy-related Myelodysplastic Syndromes/Acute Myeloid Leukemias (t-MDS/AML) are one of the most compelling long term adverse events occurring in cancer survivors treated with chemo-radiotherapy regimes. Beside several well-described genetic lesions, a growing amount of data suggests that abnormalities in DNA methylation profile contribute to multistep secondary leukemogenesis. Two distinct alterations of normal DNA methylation patterns may occur in cancer: a global hypomethylation resulting in chromosomal instability and loss of genetic integrity, and promoter specific DNA hypermethylation which leads to silencing of tumor suppressor genes. Cytotoxic drugs and radiation have been shown to affect tissue DNA methylation profile. Radiation is able to induce a stable DNA hypomethylation in both target and bystander tissues. Gene promoter methylation is a common finding in t-MDS/AML and has been associated to a shorter latency period from the treatment of the primary tumor. Among the studied genes, p15 methylation correlated to monosomy/deletion of chromosome 7q, suggesting that it could be a relevant event in alkylating agent-induced leukemogenesis. We found frequent methylation of DAPK in the t-MDS/AML group, especially in patients with a previous lymphoproliferative disease. In patients studied for concurrent methylation of several promoters, t-MDS/AML were significantly more frequently hypermethylated in 2 or more promoter regions than de novo MDS or AML suggesting that promoter hypermethylation of genes involved in cell cycle control, apoptosis and DNA repair pathways is a frequent finding in t-MDS/AML and may contribute to secondary leukemogenesis. However, how the epigenetic machinery is disrupted after chemo/radiotherapy and during secondary carcinogenesis is still unknown, warranting further studies. PMID- 19874807 TI - Efficacy of lanreotide in preventing the occurrence of chemically induced hepatocellular carcinoma in rats. AB - Hepatocellular carcinoma (HCC) is increasing worldwide and is the third cause of cancer-related death. HCC develops in a pre-neoplastic organ, the cirrhotic liver. Therefore, chemoprevention could play a role in the management of HCC. We have previously shown that lanreotide, a somatostatin analogue, inhibits the development of "foci of altered hepatocytes", which represent very early neoplastic changes in rat liver. Here we induced bona fide HCC by means of a different chemically induced model that is known to lead to significant fibrosis before HCC appearance. Lanreotide was given from the beginning of the experiment in one group and from the time when significant fibrosis was present in the second group. Lanreotide decreased the frequency of occurrence of HCC in both groups. In both groups, significant decreases in hepatocyte proliferation and inhibition of fibrosis were demonstrated. When given at the start of the experiment, lanreotide dramatically decreased levels of angiogenic factors and enhanced apoptosis. Further work on the anti-tumoral effect of lanreotide is called for to assess the mechanistic relationships of its anti-proliferative and anti-angiogenic actions on liver neoplastic cells. PMID- 19874804 TI - NT79: A novel neurotensin analog with selective behavioral effects. AB - Neurotensin, a tridecapeptide, is widely distributed in the brain and gastrointestinal tract. It possesses analgesic, hypothermic, and antipsychotic like properties. Neurotensin's effects are mediated mainly through two receptor subtypes, NTS1 and NTS2. Activation of NTS1 has been implicated in most of the pharmacological effects of neurotensin but is associated with hypothermia and hypotension. We report on a novel neurotensin analog with higher selectivity to NTS2, namely, NT79, which exhibits selective behavioral effects. NT79 was tested in animal models for pain (thermal-hot plate test; visceral-acetic acid-induced writhing test), and in animal models that are predictive of antipsychotic-like effects (apomorphine-induced climbing; d-amphetamine-induced hyperactivity; disruption of prepulse inhibition). Its effects on body temperature and on blood pressure were also determined. Neurochemical changes in extracellular neurotransmitters were measured using in vivo microdialysis while the rats were simultaneously evaluated for acetic acid-induced writhing with and without pretreatment with NT79. Binding data at molecularly cloned hNTS1 and hNTS2 suggest selectivity for hNTS2. NT79 blocked the acetic acid-induced writhing with an ED(50) of 0.14 microg/kg while having no effect on thermal nociception. The writhing was paralleled by an increase in 5-HT which was attenuated by NT79. NT79 demonstrated antipsychotic-like effects by blocking apomorphine-induced climbing, d-amphetamine-induced hyperactivity, and reducing d-amphetamine- and DOI-induced disruption of prepulse inhibition. Uniquely, it caused no significant hypothermia and was without effect on blood pressure. NT79, with its higher selectivity to NTS2, may be potentially useful to treat visceral pain, and psychosis without concomitant side effects of hypothermia or hypotension. PMID- 19874808 TI - Activation of inflammatory response and apoptosis of polymorphonuclear leukocytes in patients with argemone oil poisoning. AB - In the present study, the role of ROS and RNS in activation of inflammatory response and associated molecular events during apoptosis of polymorphonuclear leucocytes (PMNs) in patients from an outbreak of argemone oil (AO) poisoning leading to epidemic dropsy in Lucknow, India was undertaken. It was observed that generation of superoxide radical, nitrite formation and phagocytosis (103-429%) were significantly increased in PMNs of dropsy patients. Furthermore, activities of superoxide dismutase and glutathione peroxidase (GPx) (47-79%) were found to be increased while that of catalase and glutathione reductase (GR) (56-57%) were decreased. Lipid and protein oxidation, nitrotyrosine formation and 8 hydroxydeoxyguanosine (8-OHdG) excretion were significantly enhanced with concomitant depletion of GSH levels (67%) in dropsy patients. In addition, significant elevation of IL-6, IL-8 and TNF-alpha (68-406%) in plasma was observed. Apoptosis was enhanced (1.5 folds) with increased (2.0-3.6 folds) caspases 3, 8 and 9 activities along with DNA fragmentation (119%). The results suggest that generation of ROS and RNS along with enhancement of secretion of inflammatory mediators leading to DNA damage followed by apoptosis may have an effect on immune system, which in turn may be responsible for histopathological changes in target organs of dropsy patients. PMID- 19874809 TI - 2'-epi-2'-O-Acetylthevetin B extracted from seeds of Cerbera manghas L. induces cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. AB - 2'-epi-2'-O-Acetylthevetin B (GHSC-74) is a cardiac glycoside isolated from the seeds of Cerbera manghas L. We have demonstrated that GHSC-74 reduced the viability of HepG2 cells in a time- and dose-dependent manner. The present study was designed to explore cellular mechanisms whereby GHSC-74 led to cell cycle arrest and apoptosis in HepG2 cells. Cell cycle flow cytometry demonstrated that HepG2 cells treated with GHSC-74 (4microM) resulted in S and G2 phase arrest in a time-dependent manner, as confirmed by mitotic index analysis. G2 phase arrest was accompanied with down-regulation of CDC2 and Cyclin B1 protein. Furthermore, GHSC-74-induced apoptotic killing, as demonstrated by DNA fragmentation, DAPI staining, and flow cytometric detection of sub-G1 DNA content in HepG2 cells. GHSC-74 treatment resulted in a significant increase in reactive oxygen species, activation of caspase-9, dissipation of mitochondrial membrane potential, and translocation of apoptosis-inducing factor (AIF) from the mitochondrion to the nucleus in HepG2 cells. Nevertheless, after GHSC-74 exposure, no significant Fas and FasL up-regulation was observed in HepG2 cells by flow cytometry. In addition, treatment with antioxidant N-acetyl-l-cysteine (NAC) and broad-spectrum caspase inhibitor z-VAD-fmk partially prevented apoptosis but did not abrogate GHSC-74-induced nuclear translocation of AIF. In conclusion, we have demonstrated that GHSC-74 inhibited growth of HepG2 cells by inducing S and G2 phase arrest of the cell cycle and by triggering apoptosis via mitochondrial disruption including both caspase-dependent and -independent pathways, and ROS generation. PMID- 19874810 TI - Binding of a cationic phenazinium dye in anionic liposomal membrane: a spectacular modification in the photophysics. AB - Interaction of a cationic phenazinium dye, phenosafranin (PSF), with the anionic liposomal vesicle/bilayer of dimyristoyl-L-alpha-phosphatidylglycerol (DMPG) has been demonstrated using steady state and time resolved fluorescence and fluorescence anisotropy techniques. The charge transfer emission spectrum of PSF shows a dramatic modification in terms of fluorescence yield together with an appreciable hypsochromic shift in the lipid environment. The blue shift indicates a lowering in polarity inside the vesicle as compared to that in bulk water. The fluorescence and fluorescence quenching studies and micropolarity determination reveal that the cationic fluorophore has a profound binding interaction with the anionic DMPG membrane. Anisotropy study indicates the imposition of a motional restriction on the probe inside the bilayer. The electrostatic interaction between the cationic dye and the anionic lipid membrane has been argued to be the reason behind all these observations. The results could be useful in analyzing membrane organization and heterogeneity in natural membranes exploiting PSF or alike compounds as fluorescent probes. PMID- 19874811 TI - Association of IL-1F7 gene with susceptibility to human leukocyte antigen-B27 positive ankylosing spondylitis in Han Chinese population. PMID- 19874812 TI - Dhrs3a regulates retinoic acid biosynthesis through a feedback inhibition mechanism. AB - Retinoic acid (RA) is an important developmental signaling molecule responsible for the patterning of multiple vertebrate tissues. RA is also a potent teratogen, causing multi-organ birth defects in humans. Endogenous RA levels must therefore be tightly controlled in the developing embryo. We used a microarray approach to identify genes that function as negative feedback regulators of retinoic acid signaling. We screened for genes expressed in early somite-stage embryos that respond oppositely to treatment with RA versus RA antagonists and validated them by RNA in situ hybridization. Focusing on genes known to be involved in RA metabolism, we determined that dhrs3a, which encodes a member of the short-chain dehydrogenase/reductase protein family, is both RA dependent and strongly RA inducible. Dhrs3a is known to catalyze the reduction of the RA precursor all trans retinaldehyde to vitamin A; however, a developmental function has not been demonstrated. Using morpholino knockdown and mRNA over-expression, we demonstrate that Dhrs3a is required to limit RA levels in the embryo, primarily within the central nervous system. Dhrs3a is thus an RA-induced feedback inhibitor of RA biosynthesis. We conclude that retinaldehyde availability is an important level at which RA biosynthesis is regulated in vertebrate embryos. PMID- 19874813 TI - Kit ligand cytoplasmic domain is essential for basolateral sorting in vivo and has roles in spermatogenesis and hematopoiesis. AB - Juxtamembrane signaling via the membrane growth factor KitL is critical for Kit mediated functions. KitL has a conserved cytoplasmic domain and has been shown to possess a monomeric leucine-dependent basolateral targeting signal. To investigate the consequences in vivo of impaired basolateral KitL targeting in polarized epithelial cells, we have mutated this critical leucine to alanine using a knock-in strategy. KitL(L263A/L263A) mutant mice are pigmented normally and steady-state hematopoiesis is unaffected although peritoneal and skin mast cell numbers are significantly increased. KitL localization is affected in the Sertoli cells of the KitL(L263A/L263A) testis and testis size is reduced in these mice due to aberrant spermatogonial proliferation. Furthermore, the effect of the KitL L263A mutation on the testicular phenotype is dosage dependent. The tubules of hemizygous KitL(L263A/Sl) mice completely lack germ cells in contrast to the weaker testicular phenotype of KitL(L263A/L263A) mice. The onset of the testis phenotype coincides with the formation of tight junctions between Sertoli cells during postnatal development. Thus, the altered sorting of KitL is dispensable for hematopoietic and melanogenic lineages, yet is crucial in the testicular environment, where the basal membranes of adjacent polarized Sertoli cells form a niche for the proliferating spermatogonia. PMID- 19874814 TI - Challenges for modeling global gene regulatory networks during development: insights from Drosophila. AB - Development is regulated by dynamic patterns of gene expression, which are orchestrated through the action of complex gene regulatory networks (GRNs). Substantial progress has been made in modeling transcriptional regulation in recent years, including qualitative "coarse-grain" models operating at the gene level to very "fine-grain" quantitative models operating at the biophysical "transcription factor-DNA level". Recent advances in genome-wide studies have revealed an enormous increase in the size and complexity or GRNs. Even relatively simple developmental processes can involve hundreds of regulatory molecules, with extensive interconnectivity and cooperative regulation. This leads to an explosion in the number of regulatory functions, effectively impeding Boolean based qualitative modeling approaches. At the same time, the lack of information on the biophysical properties for the majority of transcription factors within a global network restricts quantitative approaches. In this review, we explore the current challenges in moving from modeling medium scale well-characterized networks to more poorly characterized global networks. We suggest to integrate coarse- and find-grain approaches to model gene regulatory networks in cis. We focus on two very well-studied examples from Drosophila, which likely represent typical developmental regulatory modules across metazoans. PMID- 19874815 TI - Pulsation and stabilization: contractile forces that underlie morphogenesis. AB - Embryonic development involves global changes in tissue shape and architecture that are driven by cell shape changes and rearrangements within cohesive cell sheets. Morphogenetic changes at the cell and tissue level require that cells generate forces and that these forces are transmitted between the cells of a coherent tissue. Contractile forces generated by the actin-myosin cytoskeleton are critical for morphogenesis, but the cellular and molecular mechanisms of contraction have been elusive for many cell shape changes and movements. Recent studies that have combined live imaging with computational and biophysical approaches have provided new insights into how contractile forces are generated and coordinated between cells and tissues. In this review, we discuss our current understanding of the mechanical forces that shape cells, tissues, and embryos, emphasizing the different modes of actomyosin contraction that generate various temporal and spatial patterns of force generation. PMID- 19874816 TI - Cytokine-dependent activation of small hepatocyte-like progenitor cells in retrorsine-induced rat liver injury. AB - Complete liver regeneration after partial hepatectomy (PH) in rats exposed to the pyrrolizidine alkaloid retrorsine is accomplished through the activation, expansion, and differentiation of a population of small hepatocyte-like progenitor cells (SHPCs). The mechanism(s) governing activation of SHPCs after PH in retrorsine-injured rats has not been investigated. We examined the possibility that SHPCs require cytokine priming prior to becoming growth factor responsive in this model of liver injury and regeneration. Male Fischer 344 rats were treated with retrorsine (30 mg/kg ip) at 6 and 8 weeks of age. Retrorsine-exposed and age matched control rats were randomized into dexamethasone-treated and no DEX groups. DEX-treated animals were either given a single dose of DEX (2 mg/kg ip) at the time of PH or multiple DEX treatments (2 mg/kg ip each) at 24 and 1 h before PH and 1, 2, and 3 days post-PH. A subset of rats received 10 microg of recombinant IL6 protein, administered intravenously 30 min after PH. Liver tissues were harvested at 7, 14, 21, and 30 days post-PH. Treatment of retrorsine exposed rats with the cytokine inhibitor dexamethasone (DEX) effectively blocked the emergence of SHPCs resulting in an inhibition of liver regeneration and producing significant short-term mortality. The livers of DEX-treated retrorsine exposed rats displayed decreased numbers and smaller SHPC clusters compared to retrorsine-exposed rats in the absence of DEX treatment. Administration of recombinant IL6 to DEX-treated retrorsine-exposed rats restored the emergence of SHPCs and SHPC-mediated regenerative response. The livers of DEX-treated retrorsine-exposed rats that received IL6 displayed numbers of expanding SHPC clusters comparable to that of retrorsine-exposed rats in the absence of DEX treatment. These results combine to suggest that SHPC activation after PH in retrorsine-exposed rats is cytokine dependent and may specifically require IL6. PMID- 19874817 TI - The relationship between transforming growth factor beta1 expression and cold ischemia injury of rat donor kidney. AB - OBJECTIVE: Cold ischemia injury represents an independent risk factor which favors chronic allograft nephropathy (CAN). In order to investigate the role of transforming growth factor-beta 1( (TGF-beta1) in the progression of CAN, we studied the relationship between the expression of TGF-beta1 and cold ischemia injury in the renal tubular epithelia of rat donor kidney. METHODS: A total of 24 Wistar rats were used in this study. In terms of the time of cryopreservation of donor kidney, the 24 Wistar rats were randomly divided into 3 groups: 0 h group(control group), 24 h group, 48 h group. A block removal of donor kidney with in situ perfusion of cooling HC-A preservation solution was adopted. The rat kidney was preserved 0 h, 24h and 48 h at 0-4 degrees C respectively. The morphologic changes of proximal tubular epithelial cells in different cryopreservation time were observed under light microscope and transmission electron microscope. The expression of TGF-beta1 mRNA and protein in proximal tubular epithelial cells of different cryopreservation time group were detected by in situ hybridization and immunohistochemistry analysis. RESULTS: 1. In 24 h group, part of the proximal tubular epithelial cells showed slight degeneration. In 48 h group, the proximal tubular epithelial cells demonstrated severe hydropic degeneration and part of the cells developed necrosis and effluxion. 2. Only a small amount of TGF-beta1 protein and mRNA were expressed in the renal tubular epithelial cells of 0 h group. The positive unit (PU) value of TGF-beta1 protein and mRNA were 6.37+/-2.77 and 5.29+/-2.15, respectively. As the cold ischemia time prolonged, the PU value of TGF-beta1 protein increased at 24 h group (10.20+/-3.27) and 48 h group (17.17+/-3.96) . The PU value of TGF-beta1 mRNA also increased at 24 h group (11.31+/-3.34) and 48 h group (19.01+/-3.53). There was the significant difference of TGF-beta1 protein PU value or mRNA PU value among these groups(P<0.05). CONCLUSION: There was the significant correlation between the expression of TGF-beta1 and the degree of cold ischemia injury. The results suggest that TGF-beta1 might play the key role in regeneration and reparation of renal tubular epithelial cell injury. The overexpression of TGF beta1 might be one of the mechanisms that initiate chronic allograft nephropathy. PMID- 19874819 TI - mRNA and micro-RNA expression analysis in laser-capture microdissected prostate biopsies: valuable tool for risk assessment and prevention trials. AB - Diagnosis of prostate cancer (PCa) typically relies on needle biopsies, which are routinely archived in paraffin after formalin fixation and may contain valuable risk or prognostic information. The objective of this study was to determine the feasibility of mRNA and miRNA expression analysis in laser-capture microdissected (LCM) formalin-fixed paraffin-embedded archived prostate biopsies compared to the gold standard of frozen tissue. We analyzed the expression of compartment specific and PCa-related genes in epithelial and stromal tissues collected from paired sets of archived prostate biopsies and frozen radical prostatectomy specimens from three patients. Our results showed appropriate compartment specific and PCa-related expression with good within patient agreement between the FFPE biopsies and the frozen tissue. The potential for both mRNA and micro RNA expression profiling in the biopsies was also demonstrated using PCR arrays which showed high correlation between the biopsy and frozen tissue, notwithstanding sensitivity limitations for mRNA detection in the FFPE specimen. This is the first study to compare RNA expression from biopsy and frozen tissues from the same patient and to examine miRNA expression in LCM-collected tissue from prostate biopsies. With careful technique and use of appropriate controls, RNA profiling from archived biopsy material is quite feasible showing high correlation to frozen tissue. PMID- 19874818 TI - Disruption of actin cytoskeleton mediates loss of tensile stress induced early phenotypic modulation of vascular smooth muscle cells in organ culture. AB - Aorta organ culture has been widely used as an ex vivo model for studying vessel pathophysiology. Recent studies show that the vascular smooth muscle cells (VSMCs) in organ culture undergo drastic dedifferentiation within the first few hours (termed early phenotypic modulation). Loss of tensile stress to which aorta is subject in vivo is the cause of this early phenotypic modulation. However, no underlying molecular mechanism has been discovered thus far. The purpose of the present study is to identify intracellular signals involved in the early phenotypic modulation of VSMC in organ culture. We find that the drastic VSMC dedifferentiation is accompanied by accelerated actin cytoskeleton dynamics and downregulation of SRF and myocardin. Among the variety of signal pathways examined, increasing actin polymerization by jasplakinolide is the only one hindering VSMC dedifferentiation in organ culture. Moreover, jasplakinolide reverses actin dynamics during organ culture. Latrunculin B (disrupting actin cytoskeleton) and jasplakinolide respectively suppressed and enhanced the expression of VSMC markers, SRF, myocardin, and CArG-box-mediated SMC promoters in PAC1, a VSMC line. These results identify actin cytoskeleton degradation as a major intracellular signal for loss of tensile stress-induced early phenotypic modulation of VSMC in organ culture. This study suggests that disrupting actin cytoskeleton integrity may contribute to the pathogenesis of vascular diseases. PMID- 19874820 TI - hnRNP M interacts with PSF and p54(nrb) and co-localizes within defined nuclear structures. AB - The abundant heterogeneous nuclear ribonucleoprotein M (hnRNP M) is able to associate with early spliceosomes and to influence splicing patterns of specific pre-mRNAs. Here, by a combination of immunoprecipitation and pull-down assays, we have identified PSF (polypyrimidine tract-binding protein-associated splicing factor) and p54(nrb), two highly related proteins involved in transcription and RNA processing, as new binding partners of hnRNP M. HnRNP M was found to co localize with PSF within a subset of nuclear paraspeckles and to largely co fractionate with PSF and p54(nrb) in biochemical nuclear matrix preparations. In cells transfected with an alternatively spliced preprotachykinin (PPT) minigene expression of hnRNP M promoted exon skipping while expression of PSF favours exon inclusion. The latter effect was reverted specifically by co-expressing the full length hnRNP M or a deletion mutant capable of interaction with PSF and p54(nrb). Together our data provide new insights and some functional implications on the hnRNP M network of interactions. PMID- 19874821 TI - Inhibition of UV-B induced apoptosis in corneal epithelial cells by potassium channel modulators. AB - The goal of this study was to determine whether prevention of K(+) loss can protect human corneal-limbal epithelial (HCLE) cells from UV-B induced apoptosis. Immunostaining for activated caspase-3 of HCLE cells exposed to 150-200 mJ/cm(2) UV-B demonstrated induction of apoptosis 6 h after exposure. The number of apoptotic cells was decreased by incubation in medium with 25 or 100 mM K(+). If this protection is due to a reduction of UV-induced K(+) loss then K(+) channel blockers should also protect HCLE cells from UV-B. Caspase-8 activity induced by exposure to UV-B at 150 mJ/cm(2) was significantly reduced when the cells were incubated in 0.3 microM BDS-I or 0.05-1 mM quinidine. Caspase-3 was also activated by UV-B and a reduction in activity was observed after incubation in 0.1-0.3 microM BDS-I and 0.1-1 mM quinidine. Induction of DNA fragmentation, as measured by the TUNEL assay, was decreased by treatment with 0.3 microM BDS-I and 0.01-0.05 mM quinidine. Patch-clamp recording showed activation of K(+) channels after exposure to UV-B and a decrease in outward K(+) current was observed following application of BDS-I. Quinidine did not block K(+) currents in HCLE cells, suggesting that the protective effect of quinidine occurs by a mechanism other than via K(+) channels. The effect of the K(+) channel blocker BDS-1 on HCLE cells exposed to UV-B confirms that preventing K(+) efflux protects corneal epithelial cells from apoptosis. This suggests the elevated [K(+)] in tears may protect the corneal epithelium from effects of ambient UV-B. PMID- 19874822 TI - Functional imaging of putative human mirror neuron systems in neurological disease. PMID- 19874823 TI - Toxoplasma gondii: Recombinant GRA5 antigen for detection of immunoglobulin G antibodies using enzyme-linked immunosorbent assay. AB - In this study, for the first time, the evaluation of Toxoplasma gondii full length recombinant GRA5 antigen for the serodiagnosis of human toxoplasmosis is shown. The recombinant GRA5 antigen as a fusion protein containing His-tag at both terminals was obtained using an Escherichia coli expression system. The usefulness of rGRA5 for the diagnosis of toxoplasmosis in an ELISA was tested on a total of 189 sera from patients with different stages of the infection and 31 sera from sero-negative individuals, obtained during routine diagnostic tests. Anti-GRA5 IgG antibodies were detected in 70.9% of all seropositive serum samples. This result was comparable to ELISA using a Toxoplasma lysate antigen (TLA) and six combinations of recombinant antigens. The sensitivity of IgG ELISA calculated from all positive serum samples was similar for TLA (94.2%), rMAG1+rSAG1+rGRA5 (92.6%), rGRA2+rSAG1+rGRA5 (93.1%) and rROP1+rSAG1+rGRA5 (94.2%) cocktails, whereas the sensitivity of cocktails without rGRA5 antigens was lower giving 82.0%, 86.2% and 87.8%, respectively. Thus, the present study showed that the full-length rGRA5 is suitable for use as a component of an antigen cocktail for the detection of anti-T. gondii IgG antibodies. PMID- 19874825 TI - Pancreatic cancer cells activate CCL5 expression in mesenchymal stromal cells through the insulin-like growth factor-I pathway. AB - Mesenchymal stromal cells (MSCs) have a critical role in cancer progression and metastasis. Despite extensive studies of the physiological responses in cancer cells, the molecular mechanisms regulating gene expression in MSCs by cancer cells remain undefined. Here we demonstrate that CC chemokine ligand 5 (CCL5) expression was increased in MSCs co-cultured with pancreatic cancer cells (PCCs), and this activation was dependent on extracellular insulin-like growth factor (IGF-I). Moreover, CCL5 induction in MSCs was required for the activation of IGF I pathway in PCCs. These results reveal a link between the IGF-I pathway in PCCs and CCL5 pathway in MSCs through the interaction of those cells. PMID- 19874824 TI - Glycosynaptic microdomains controlling tumor cell phenotype through alteration of cell growth, adhesion, and motility. AB - Glycosphingolipids (GSLs) GM3 (NeuAcalpha3Galbeta4Glcbeta1Cer) and GM2 (GalNAcbeta4[NeuAcalpha3]Galbeta4Glcbeta1Cer) inhibit (i) cell growth through inhibition of tyrosine kinase associated with growth factor receptor (GFR), (ii) cell adhesion/motility through inhibition of integrin-dependent signaling via Src kinases, or (iii) both cell growth and motility by blocking "cross-talk" between integrins and GFRs. These inhibitory effects are enhanced when GM3 or GM2 are in complex with specific tetraspanins (TSPs) (CD9, CD81, CD82). Processes (i)-(iii) occur through specific organization of GSLs with key molecules (TSPs, caveolins, GFRs, integrins) in the glycosynaptic microdomain. Some of these processes are shared with epithelial-mesenchymal transition induced by TGFbeta or under hypoxia, particularly that associated with cancer progression. PMID- 19874826 TI - Inactivation of the complement anaphylatoxin C5a by secreted products of parasitic nematodes. AB - Given the importance of the complement anaphylatoxins in cellular recruitment during infection, the ability of secreted products from larval stages of Brugia malayi and Trichinella spiralis to influence C5a-mediated chemotaxis of human peripheral blood granulocytes in vitro was examined. Secreted products from B. malayi microfilariae almost completely abolished chemotaxis. This inhibition was blocked by phenylmethylsulphonyl fluoride, indicating the presence of a serine protease, which was subsequently shown to cleave C5a. In contrast, secreted products from T. spiralis infective larvae showed modest inhibition of C5a mediated granulocyte chemotaxis, and this was blocked by potato carboxypeptidase inhibitor, an inhibitor of several metallocarboxypeptidases. Adult and larval stages of both parasites were demonstrated to secrete carboxypeptidases which cleaved hippuryl-L-lysine and hippuryl-L-arginine, and the T. spiralis enzyme was partially characterised. The data are discussed with reference to inflammation in parasitic nematode infection. PMID- 19874827 TI - Technical advancement in regulatory T cell isolation and characterization using CD127 expression in patients with malignant glioma treated with autologous dendritic cell vaccination. AB - We have successfully treated over two hundred high-grade glioma (HGG) patients with immunotherapy consisting of vaccination with autologous dendritic cells (DCs) loaded with autologous tumour lysate. It has been documented that regulatory T cells (Treg) can counteract anti-tumour immune responses. Therefore, monitoring of Treg in these patients is essential. Up till now, Treg have been characterized based on the expression of the transcription factor Foxp3. Here, we validated IL-7 receptor alpha subunit (CD127)dim expression as a marker for human Treg within HGG patients, as a less laborious assay for routine use in tumour vaccination trials. We noted a strong positive correlation between Foxp3 expression and CD127dim expression in CD4+CD25+ and CD4+ cells. The suppressive function of CD4+CD127dim cells was assessed in an allogeneic mixed lymphocyte reaction (MLR). We conclude that CD127 staining is a fast, well-suited and reproducible Treg monitoring tool in HGG patients treated with immunotherapy. PMID- 19874828 TI - Diffusion of the restriction nuclease EcoRI along DNA. AB - Many specific sequence DNA binding proteins locate their target sequence by first binding to DNA nonspecifically, then by linearly diffusing or hopping along DNA until either the protein dissociates from the DNA or it finds the recognition sequence. We have devised a method for measuring one-dimensional diffusion along DNA based on the ratio of the dissociation rate of protein from DNA fragments containing one specific binding site to the dissociation rate from DNA fragments containing two specific binding sites. Our extensive measurements of dissociation rates and specific-nonspecific relative binding constants of the restriction nuclease EcoRI enable us to determine the diffusion rate of nonspecifically bound protein along the DNA. By varying the distance between the two binding sites, we confirm a linear diffusion mechanism. The sliding rate is relatively insensitive to salt concentration and osmotic pressure, indicating that the protein moves smoothly along the DNA probably following the helical phosphate-sugar backbone of DNA. We calculate a diffusion coefficient for EcoRI of 3 x 10(4) bp(2) s(-)(1) EcoRI is able to diffuse approximately 150 bp, on average, along the DNA in 1 s. This diffusion rate is about 2000-fold slower than the diffusion of free protein in solution. A factor of 40-50 can be accounted for by rotational friction resulting from following the helical path of the DNA backbone. Two possibilities could account for the remaining activation energy: salt bridges between the DNA and the protein are transiently broken, or the water structure at the protein-DNA interface is disrupted as the two surfaces move past each other. PMID- 19874829 TI - Strain differences in the distribution of N-methyl-d-aspartate and gamma (gamma) aminobutyric acid-A receptors in rat brain. AB - AIMS: Previous studies have shown that the Wistar-Kyoto (WKY) rat strain exhibits depressive symptoms such as anhedonia, psychomotor retardation, ambivalence and negative memory bias following exposure to stress. Given the involvement of excitatory glutamate and inhibitory gamma (gamma)-aminobutyric acid (GABA) signaling pathways in influencing depressive behavior, the present study investigated strain differences in the distribution of central N-methyl-d aspartate (NMDA) and GABA(A) receptor sites in WKY compared to their inbred counterpart, Wistar (WIS) rats. MAIN METHODS: Quantitative autoradiographic analysis was used to map the binding and distribution of NMDA and GABA(A) receptors in various brain regions in WKY and WIS rats. KEY FINDINGS: Results indicated a significant difference between the two strains. Lower NMDA receptor binding was found in the anterior cingulate cortex, caudate putmen, nucleus accumbens, CA1 region of the hippocampus and the substantia nigra pars reticulata in WKY compared to WIS rats. Conversely, higher GABA(A) receptor binding was found in the amygdala, caudate putmen, dentate gyrus, CA2 and CA3 fields of the hippocampus, periaqueductal grey and substantia nigra pars reticulata in WKY compared to WIS rats. SIGNIFICANCE: Given that these two rat strains differ in their behavioural, endocrine and neurochemical profile, the observed strain differences in NMDA and GABA(A) receptor binding suggest that these two neurotransmitter systems may be involved in the depressive and stress-sensitive phenotype of the WKY rat strain. PMID- 19874830 TI - Existence of NO-triggered vagal afferent activation in the rat gastric mucosa. AB - AIM: We previously reported the possible involvement of mucosal nitric oxide (NO) triggered 5-HT release in luminal glutamate sensing by the gastric vagus nerve, and we proposed that the stomach, like the duodenum, could "taste" luminal nutrients. Nitric oxide synthase (NOS) is widely distributed in the gastric mucosa, but the physiological role of mucosal NO is not well understood. In this study, we investigated the functional coupling of NO and vagal nerve endings in the gastric mucosa. MAIN METHODS: For electrophysiological recordings, male Sprague-Dawley rats were anesthetized with urethane, and afferent nerve responses of rat vagal gastric branches to a NO donor were monitored. KEY FINDINGS: Intravenous application of 100microg/kg sodium nitroprusside (SNP) transiently increased afferent nerve discharges of the rat ventral gastric vagus, which was followed by rapid changes in blood pressure. High doses of SNP (>300microg/kg, i.v.) showed a biphasic increase in afferent discharges. Secondary activation of the vagal afferent continued even after blood pressure returned to basal levels. SNP-evoked afferent responses were abolished by mucosal 5-HT depletion using p cholorophenylalanine and were inhibited by pre- and post-treatment with the 5 HT(3) antagonist granisetron. SIGNIFICANCE: These pharmacological results strongly indicate that NO-triggered 5-HT release is coupled to vagal afferent activation in the rat gastric mucosa. PMID- 19874831 TI - Mutagenicity of N3-methyladenine: a multi-translesion polymerase affair. AB - We recently demonstrated that Polzeta and Rev1 contribute to alleviate the lethal effects of Me-lex, which selectively generates 3-methyladenine, by error prone lesion bypass. In order to determine the role of Poleta in the biological fate of Me-lex induced lesions, the RAD30 (Poleta) gene was deleted in the yIG397 parental strain and in its rev3 (Polzeta) derivative, and the strains transformed with plasmid DNA damaged in vitro by Me-lex. While deletion of RAD30 increased the toxicity of Me-lex, the impact on mutagenicity varied depending on the concentration of Me-lex induced DNA damage and the overall TLS capacity of the cells. For the first time the Me-lex induced mutation spectrum in rad30 strain was determined and compared with the spectrum previously determined in WT strain. Overall, the two mutation spectra were not significantly different. The effect on mutation frequency and the features of the Me-lex induced mutation spectra were suggestive of error prone (significant decrease of mutation frequency and significant decrease of AT>TA at a mutation hotspot in rad30 vs RAD30) but also error free (significant increase of AT>GC in rad30 vs RAD30) Poleta dependent bypass of lesions. In summary, our previous results with Polzeta and Rev1 mutants, the present results with Poleta, and the known physical and functional interactions among TLS proteins, lead us to propose that the bypass of Me-lex induced lesions is a multi-DNA polymerases process that is mostly effective when all three yeast TLS polymerases are present. PMID- 19874832 TI - Silver nanoparticles induced heat shock protein 70, oxidative stress and apoptosis in Drosophila melanogaster. AB - Due to the intensive commercial application of silver nanoparticles (Ag NPs), risk assessment of this nanoparticle is of great importance. Our previous in vitro study demonstrated that Ag NPs caused DNA damage and apoptosis in mouse embryonic stem cells and fibroblasts. However, toxicity of Ag NPs in vivo is largely lacking. This study was undertaken to examine the toxic effects of well characterized polysaccharide coated 10 nm Ag NPs on heat shock stress, oxidative stress, DNA damage and apoptosis in Drosophila melanogaster. Third instar larvae of D. melanogaster were fed a diet of standard cornmeal media mixed with Ag NPs at the concentrations of 50 and 100 microg/ml for 24 and 48 h. Ag NPs up regulated the expression of heat shock protein 70 and induced oxidative stress in D. melanogaster. Malondialdehyde level, an end product of lipid peroxidation was significantly higher while antioxidant glutathione content was significantly lower in Ag NPs exposed organisms. Activities of antioxidant enzyme superoxide dismutase and catalase were also significantly higher in the organisms exposed to Ag NPs. Furthermore, Ag NPs up-regulated the cell cycle checkpoint p53 and cell signaling protein p38 that are involved in the DNA damage repair pathway. Moreover, activities of caspase-3 and caspase-9, markers of apoptosis were significantly higher in Ag NPs exposed organisms. The results indicate that Ag NPs in D. melanogaster induce heat shock stress, oxidative stress, DNA damage and apoptosis. This study suggests that the organism is stressed and thus warrants more careful assessment of Ag NPs using in vivo models to determine if chronic exposure presents developmental and reproductive toxicity. PMID- 19874833 TI - Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro. AB - Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 microg/ml) and MEHP (0.1-10 microg/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin dependent-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators. PMID- 19874834 TI - Adverse health effects due to arsenic exposure: modification by dietary supplementation of jaggery in mice. AB - Populations of villages of eastern India and Bangladesh and many other parts of the world are exposed to arsenic mainly through drinking water. Due to non availability of safe drinking water they are compelled to depend on arsenic contaminated water. Generally, poverty level is high in those areas and situation is compounded by the lack of proper nutrition. The hypothesis that the deleterious health effects of arsenic can be prevented by modification of dietary factors with the availability of an affordable and indigenous functional food jaggery (sugarcane juice) has been tested in the present study. Jaggery contains polyphenols, vitamin C, carotene and other biologically active components. Arsenic as sodium-m-arsenite at low (0.05 ppm) and high (5 ppm) doses was orally administered to Swiss male albino mice, alone and in combination with jaggery feeding (250 mg/mice), consecutively for 180 days. The serum levels of total antioxidant, glutathione peroxidase and glutathione reductase were substantially reduced in arsenic-exposed groups, while supplementation of jaggery enhanced their levels in combined treatment groups. The serum levels of interleukin-1beta, interleukin-6 and TNF-alpha were significantly increased in arsenic-exposed groups, while in the arsenic-exposed and jaggery supplemented groups their levels were normal. The comet assay in bone marrow cells showed the genotoxic effects of arsenic, whereas combination with jaggery feeding lessened the DNA damage. Histopathologically, the lung of arsenic-exposed mice showed the necrosis and degenerative changes in bronchiolar epithelium with emphysema and thickening of alveolar septa which was effectively antagonized by jaggery feeding. These results demonstrate that jaggery, a natural functional food, effectively antagonizes many of the adverse effects of arsenic. PMID- 19874835 TI - Proteomics-based safety evaluation of multi-walled carbon nanotubes. AB - This study evaluated the biological responses to multi-walled carbon nanotubes (MWCNTs). Human monoblastic leukemia cells (U937) were exposed to As-grown MWCNTs and MWCNTs that were thermally treated at 1800 degrees C (HTT1800) and 2800 degrees C (HTT2800). Cell proliferation was highly inhibited by As-grown but not HTT2800. However, both As-grown and HTT1800, which include some impurities, were cytotoxic. Proteomics analysis of MWCNT-exposed cells revealed 37 protein spots on 2-dimensional electrophoresis gels that significantly changed (p<0.05) after exposure to HTT1800 with a little iron and 20 spots that changed after exposure to HTT2800. Peptide mass fingerprinting identified 45 proteins that included heat shock protein beta-1, neutral alpha-glucosidase AB, and DNA mismatch repair protein Msh2. These altered proteins play roles in metabolism, biosynthesis, response to stress, and cell differentiation. Although HTT2800 did not inhibit cell proliferation or cause cytotoxicity in vitro, some proteins related to the response to stress were changed. Moreover, DJ-1 protein, which is a biomarker of Parkinson's disease and is related to cancer, was identified after exposure to both MWCNTs. These results show that the cytotoxicity of MWCNTs depends on their impurities, such as iron, while MWCNTs themselves cause some biological responses directly and/or indirectly in vitro. Our proteomics-based approach for detecting biological responses to nanomaterials is a promising new method for detailed safety evaluations. PMID- 19874836 TI - Identification of arsenite-and arsenic diglutathione-binding proteins in human hepatocarcinoma cells. AB - It is generally accepted that trivalent arsenicals are more toxic than the corresponding pentavalent arsenicals, since trivalent arsenicals bind the thiol groups of biomolecules, leading to a deterioration in cellular functions. In the present study, we prepared three different arsenic-bound sepharoses and investigated the binding of hepatic cytosolic proteins to pentavalent, trivalent, and glutathione-conjugated trivalent arsenicals. SDS-PAGE showed no proteins bound to pentavalent arsenic specifically. In contrast, we found a number of proteins that have specific and high affinity for trivalent arsenic. Two of those proteins were identified: protein disulfide isomerase-related protein 5 (PDSIRP5) and peroxiredoxin 1/enhancer protein (PRX1/EP). These proteins have vicinal cysteines, as previously reported. In contrast, one of the prominent proteins that did not bind to trivalent arsenic was identified as calreticulin precursor. Although there are 3 cysteines in calreticulin precursor, two of the cysteines are spaced more than 25 amino acids apart. Five synthetic peptides containing 2 vicinal cysteines were prepared to study whether they would inhibit the binding of PDSIRP5, PRX1/EP, and other arsenic-binding proteins to trivalent arsenicals. Only two of the five peptides effectively inhibited binding, suggesting that other amino acids besides the 2 vicinal cysteines may modulate the affinity of cysteine-rich proteins for trivalent arsenicals. We further investigated hepatic cytosolic proteins that bound specifically to glutathione-conjugated trivalent arsenic, which is the most abundant form of arsenical in bile fluid. Four proteins that bound specifically to glutathione-conjugated trivalent arsenic were identified; interestingly, these proteins were different from the trivalent arsenic-binding proteins. These results suggest that although glutathione conjugation is an important process in the metabolism, excretion, and detoxification of arsenicals, glutathione-conjugated arsenicals can still react with some proteins in hepatic cells. PMID- 19874837 TI - The B[a]P-increased intercellular communication via translocation of connexin-43 into gap junctions reduces apoptosis. AB - Gap junctions are channels in plasma membrane composed of proteins called connexins. These channels are organized in special domains between cells, and provide for direct gap junctional intercellular communication (GJIC), allowing diffusion of signalling molecules <1 kD. GJIC regulates cell homeostasis and notably the balance between proliferation, cell cycle arrest, cell survival and apoptosis. Here, we have investigated benzo[a]pyrene (B[a]P) effects on GJIC and on the subcellular localization of the major protein of gap junction: connexin-43 (Cx43). Our results showed that B[a]P increased GJIC between mouse hepatoma Hepa1c1c7 cells via translocation of Cx43 from Golgi apparatus and lipid rafts into gap junction plaques. Interestingly, inhibition of GJIC by chlordane or small interference RNA directed against Cx43 enhanced B[a]P-induced apoptosis in Hepa1c1c7 cells. The increased apoptosis caused by inhibition of GJIC appeared to be mediated by ERK/MAPK pathway. It is suggested that B[a]P could induce transfer of cell survival signal or dilute cell death signal via regulation of ERK/MAPK through GJIC. PMID- 19874838 TI - State of the art on cyanotoxins in water and their behaviour towards chlorine. AB - The occurrence of cyanobacterial blooms is drastically increasing in temperate countries and drinking water resources are threatened. As a result, cyanotoxins should be considered in water treatment to protect human health. This study presents a state of the art on cyanotoxins in water and their behaviour towards chlorination, a common drinking water disinfection process. Chlorination efficiency on cyanotoxins alteration depends on pH, chlorine dose and oxidant nature. Microcystins and cylindrospermopsin are efficiently transformed by chlorine, with respectively 6 and 2 by-products identified. In addition, chlorination of microcystins and cylindrospermopsin is associated with a loss of acute toxicity. Even though they have been less investigated, saxitoxins and nodularins are also altered by chlorine. For these toxins, no by-products have been identified, but the chlorinated mixture does not show acute toxicity. On the contrary, the fact that anatoxin-a has a very slow reaction kinetics suggests that this toxin resists chlorination. PMID- 19874839 TI - Understanding the in vitro neuromuscular activity of snake venom Lys49 phospholipase A2 homologues. AB - Phospholipases A(2) (PLA(2)s) with a lysine substituting for the highly conserved aspartate 49, Lys49 PLA(2) homologues, are important myotoxic components in venoms from snakes of Viperidae family. These proteins induce conspicuous myonecrosis by a catalytically-independent mechanism. Traditionally, the Lys49 PLA(2) homologues are classified as non-neurotoxic myotoxins given their inability to cause lethality or paralytic effects when injected in vivo, even at relatively high doses. However, a series of in vitro studies has shown that several Lys49 PLA(2) homologues from Bothrops snake venoms induce neuromuscular blocking activity on nerve-muscle preparations in vitro. The interpretation of these findings has created some confusion in the literature, raising the question whether the Lys49 PLA(2) homologues present some neurotoxic activity. The present article reviews the in vitro neuromuscular effects of Lys49 PLA(2) homologues and discusses their possible mechanisms of action. It was concluded that the neuromuscular blockade induced by Lys49 PLA(2) homologues in isolated preparations is mainly a consequence of the general membrane-destabilizing effect of these toxins. PMID- 19874840 TI - Parabutoporin, a cationic amphipathic peptide from scorpion venom: much more than an antibiotic. AB - Parabutoporin (PP) from the South African scorpion Parabuthus schlechteri is a 45 mer lysine-rich and cysteine-free peptide. At micromolar concentrations it has antimicrobial effects against G+ and G- bacteria and is antifungal as well. However, at submicromolar concentrations, parabutoporin also directly interferes with cellular functions of the human innate immune system, especially polymorphonuclear neutrophils (PMN): parabutoporin acts as a chemoattractant for neutrophils, induces their degranulation, while delaying constitutive neutrophil apoptosis. In addition, it potently inhibits induced superoxide production. Different signalling pathways regulating these biochemical processes were identified as targets of parabutoporin. Therefore, parabutoporin is a well documented scorpion venom peptide with immuno-regulatory properties beyond its antibiotic effects. PMID- 19874841 TI - Pre-clinical and preliminary dose-finding and safety studies to identify candidate antivenoms for treatment of envenoming by saw-scaled or carpet vipers (Echis ocellatus) in northern Nigeria. AB - The aim of this study was to identify candidate antivenoms with specific activity against the venom of the saw-scaled or carpet viper (Echis ocellatus) in northern Nigeria, where bites by this species cause great morbidity and mortality but where effective antivenoms have become scarce and unaffordable. Selected antivenoms were destined to be compared by randomised controlled clinical trials (RCTs). Standard pre-clinical neutralisation assays were carried out in rodents. We included two licensed antivenoms of established clinical efficacy and 6 candidate antivenoms. Although 6 of the tested antivenoms showed promising efficacy, all but 3 were excluded from further study because of inadequate pre clinical efficacy or because they were unavailable or unaffordable for the anticipated RCTs. Median effective doses (ED(50)) of the remaining three candidate antivenoms suggested that the following doses might neutralise the maximum observed venom yield of 24.8 mg (dry weight) of venom milked from captive E. ocellatus: 10 ml of MicroPharm "EchiTAb G" (ET-G) antivenom; 30 ml of Instituto Clodomiro Picado "EchiTAb-Plus-ICP" (ET-Plus) antivenom; 50 ml of VacSera, Cairo "EgyVac" antivenom. A preliminary clinical dose-finding and safety study of these three antivenoms was carried out in 24 patients with incoagulable blood after E. ocellatus bites who were not severely envenomed. A 3+3 dose escalation design was employed. Initial doses of 10 ml ET-G and 30 ml ET-Plus restored blood coagulability in groups of 6 patients with early mild reactions (pruritus only) in not more than one third of them. EgyVac antivenom did not fulfil efficacy or safety criteria in 12 patients. On the basis of these results, ET-G and ET-Plus were selected for comparison in a RCT. PMID- 19874842 TI - Adult weight gain and diabetes among African American and white adults in southeastern US communities. AB - OBJECTIVE: To examine associations between adult weight gain and diabetes among African Americans and Whites. METHOD: Cross-sectional interview data from 19,589 African American men, 6202 White men, 27,021 African American women, and 11,623 White women enrolled in the Southern Community Cohort Study in the southeastern USA from 2002 to 2009 were analyzed in multivariate logistic regression models to examine odds ratios and 95% confidence intervals between self-reported diabetes and weight change from age 21. RESULTS: Diabetes odds rose with increasing weight gain and effects varied somewhat by race and gender; odds ratios (95% confidence interval) for diabetes associated with weight gain of 40+ kg compared to stable weight (change <5 kg) were 3.3 (2.8-4.0) for African American males, 3.6 (2.7 4.8) for White males, 2.6 (2.3-3.1) for African American females, and 4.0 (3.2 4.9) for White females. Among women, significantly increased diabetes odds (41% for Whites and 21% for African Americans) were observed even for weight gain of 5 10 kg. Relative increases in odds ratios for diabetes were most pronounced among individuals who had a healthy body mass index (18.5-24.9 kg/m2) at age 21 compared to those already overweight. CONCLUSION: Adult weight gain is strongly associated with diabetes across gender and race groups indicating that a uniform prevention message can be presented, even to those of healthy weight. PMID- 19874843 TI - Anti-inflammatory effect of the polysaccharides of golden needle mushroom in burned rats. AB - The present study was to investigate chemical components of polysaccharides isolated from Golden needle (GNP) mushroom using high performance liquid chromatography (HPLC) and nuclear magnetic resonance spectroscopy (NMR). Then, anti-inflammatory effect of the polysaccharides was also evaluated. Results indicated that GNP was composed of the three monosaccharides (glucose, mannose and xylose) with a molar ratio of 3.5:0.8:1.4. GNP could significantly decreased CD4+ CD8+, ICAM-1, and MPO in serum and colon of normal and burned rats. It could be concluded that GNP possessed strong anti-inflammatory activity in burned rats. PMID- 19874844 TI - Influences of cationic, anionic, and nonionic surfactants on alkaline-induced intermediate of bovine serum albumin. AB - The formation of one molten globule-like intermediate of bovine serum albumin (BSA) at pH 11.2 has been established by circular dichroism (CD) spectra, fluorescence spectroscopy and 'phase diagram' approach. Three types of surfactants induced alpha-helical structure and resumed the tertiary structure of alkaline-induced BSA intermediate. The internalized tryptophans of the intermediate were exposed to a more polar environment in the presence of surfactants. Induction of both secondary and tertiary structures in alkaline unfolded BSA was greater in the presence of 3.5 mM cetyltrimethylammonium bromide (CTAB) followed by 8.0 mM sodium dodecyl sulphate (SDS) and the least in 0.1 mM Tween-20. Maximum ANS binding was obtained in the presence of 0.1 mM Tween-20 followed by 8.0 mM SDS. The addition of 3.5 mM CTAB resulted in loss of ANS binding sites, suggesting the burial of hydrophobic patches. PMID- 19874845 TI - Structure elucidation and antioxidant activity of a novel alpha-(1-->3),(1-->4)-D glucan from Aconitum kusnezoffii Reichb. AB - Aconitum kusnezoffii Reichb. has been used as traditional Chinese medicine over the last 2500 years, but its polysaccharides have been paid little attention by now. In the present study, a hot alkali extracted polysaccharide (AKP) from A. kusnezoffii Reichb. was characterized to be an alpha-(1-->3),(1-->4)-D-glucan with Mw 1.4 x 10(5) Da, of which (1-->3)-linked and (1-->4)-linked alpha-Glcp residues were in a ratio of 1:7. In vitro antioxidant testing indicated that AKP had significant ferrous ion-chelating ability, reducing power and scavenging effects on DPPH radical, hydroxyl radical, superoxide anion, H2O2 and self oxidation of 1,2,3-phentriol, suggesting that it should be explored as a novel natural antioxidant. PMID- 19874846 TI - Purification and characterization of a thermostable phytate resistant alpha amylase from Geobacillus sp. LH8. AB - A thermophilic and amylolytic bacterium (LH8) was isolated from the hot spring of Larijan in Iran at 65 degrees C. Identification of strain LH8 by 16S rDNA sequence analysis showed that LH8 strain belongs to the Geobacillus sp. with 99% sequence similarity with the 16S rDNA of Geobacillus thermodenitrificans. A new alpha-amylase (GA) was extracted from this strain and purified by ion-exchange chromatography. SDS-PAGE showed a single band with an apparent molecular mass of 52kDa. The optimum temperature and pH were 80 degrees C and 5-7, respectively. In the presence of Mn2+, Ca2+, K+, Cr3+ and Al3+, the enzyme activity was stimulated while Mg2+, Ba2+, Ni2+, Zn2+, Fe3+, Cu2+ and EDTA reduced the activity. The K(m) and V(max) values for starch were 3 mg ml(-1) and 6.5 micromol min(-1), respectively. The gene encoding alpha-amylase was isolated and the amino acid sequence was deduced. Comparison of GA and other alpha-amylase amino acid sequences suggested that GA has conserved regions that were previously identified in alpha-amylase family but GA exhibited some substitutions in the sequence. Its phytate resistant is an important property of this enzyme. 5 and 10 mM phytic acid did not inhibit this enzyme. Therefore, features of phytate resistant alpha amylase from Geobacillus sp. LH8 are discussed. PMID- 19874847 TI - Rapid influenza diagnostic test during the outbreak of the novel influenza A/H1N1 2009 in Thailand: an experience with better test performance in resource limited setting. PMID- 19874848 TI - De-regulated FGF receptors as therapeutic targets in cancer. AB - Fibroblast growth factors (FGFs) acting through their cognate receptors (FGFRs) play vital roles in development and de-regulation of FGF/FGFR signalling is associated with many developmental syndromes. In addition there is much interest in inhibiting FGF/FGFR signalling as a therapeutic approach to cancer. FGF/FGFR signalling is certainly important in tumour angiogenesis but studies in the last few years have uncovered increasing evidence that FGFRs are driving oncogenes in certain cancers and act in a cell autonomous fashion to maintain the malignant properties of tumour cells. These observations make FGFRs increasingly attractive as targets for therapeutic intervention in cancer. In this article, we review FGFR signalling and describe recent advances in cancer genomics and cancer cell biology that demonstrate that specific tumour types are dependent upon or addicted to de-regulated FGFR. We also describe the range of therapeutic strategies currently employed or in development to antagonise de-regulated FGFRs including antibodies and small molecule tyrosine kinase inhibitors. PMID- 19874849 TI - Anticancer drugs and cardiotoxicity: Insights and perspectives in the era of targeted therapy. AB - Drug-induced cardiotoxicity is emerging as an important issue among cancer survivors. For several decades, this topic was almost exclusively associated with anthracyclines, for which cumulative dose-related cardiac damage was the limiting step in their use. Although a number of efforts have been directed towards prediction of risk, so far no consensus exists on the strategies to prevent and monitor chemotherapy-related cardiotoxicity. Recently, a new dimension of the problem has emerged when drugs targeting the activity of certain tyrosine kinases or tumor receptors were recognized to carry an unwanted effect on the cardiovascular system. Moreover, the higher than expected incidence of cardiac dysfunction occurring in patients treated with a combination of old and new chemotherapeutics (e.g. anthracyclines and trastuzumab) prompted clinicians and researchers to find an effective approach to the problem. From the pharmacological standpoint, putative molecular mechanisms involved in chemotherapy-induced cardiotoxicity will be reviewed. From the clinical standpoint, current strategies to reduce cardiotoxicity will be critically addressed. In this perspective, the precise identification of the antitarget (i.e. the unwanted target causing heart damage) and the development of guidelines to monitor patients undergoing treatment with cardiotoxic agents appear to constitute the basis for the management of drug-induced cardiotoxicity. PMID- 19874850 TI - Mechanism of tumor cell-induced T-cell apoptosis mediated by galectin-1. AB - Galectin-1 (Gal-1) has been implicated in tumor progression partly via the induction of T-cell apoptosis. However the mechanism of Gal-1 induced T-cell death was mostly studied using recombinant, soluble Gal-1 producing controversial results. To explore the true mechanism of Gal-1 and hence tumor cell-induced T cell death, we applied co-cultures of tumor cells and T-cells thus avoiding artificial circumstances generated using recombinant protein. T-cells died when co-cultured with Gal-1-expressing but survived with Gal-1 non-expressing tumor cells. Removing tumor cell surface Gal-1 or knocking down Gal-1 expression resulted in diminution of T-cell apoptosis. Gal-1 transgenic or soluble Gal-1 treated HeLa cells became cytotoxic. Stimulation of apoptosis required interaction between the tumor and T-cells, presence of p56lck and ZAP70, decrease of mitochondrial membrane potential and caspase activation. Hence tumor cell derived Gal-1 might efficiently contribute to tumor self-defense. Moreover this system resolves the discrepancies obtained using recombinant Gal-1 in T-cell apoptosis studies. PMID- 19874852 TI - Sexual transmission of HIV-1. AB - HIV-1 transmission occurs in a limited number of ways all of which are preventable. Overall, the risk of HIV-1 transmission following a single sexual exposure is low especially in comparison with other sexually transmitted infections (STIs); with estimates of the average probability of male to female HIV-1 transmission only 0.0005-0.0026 per coital act. The risk of acquiring HIV-1 from a single contact varies enormously and is dependant upon the infectiousness of the HIV-1 positive individual and the susceptibility to HIV-1 of their sexual partner. An understanding of the determinants of HIV-1 transmission is important not only to assess the infection risk to an individual when exposed to the virus (e.g. to determine the provision of post exposure prophylaxis), but also to make accurate predictions on the potential spread of HIV-1 infection in a population and to direct appropriate targeted prevention strategies. In this review article we summarise the current literature on the major worldwide source of HIV-1 acquisition, sexual transmission. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010. PMID- 19874853 TI - Efficacy of favipiravir (T-705) and T-1106 pyrazine derivatives in phlebovirus disease models. AB - Several studies have reported favipiravir (T-705) to be effective in treating a number of viral diseases modeled in rodent systems. Notably, the related pyrazine derivative, T-1106, was found to be more effective than T-705 in treating yellow fever virus infection in hamsters. Based on these findings, we hypothesized that T-1106 may be more effective in treating hepatotropic Punta Toro virus (PTV, Phlebovirus) infection in rodents. In cell culture, the inhibitory concentrations of the compounds against various phleboviruses ranged from 3 to 55microM for T 705 and from 76 to 743microM for T-1106. In PTV-challenged hamsters, a model that generally presents with high liver viral loads, T-1106 was more effective at reducing mortality. However, in mice infected with PTV, a model wherein systemic infection is more prominent, the greater efficacy exhibited by T-1106 in the hamster system was not apparent. In contrast, T-705 was superior in preventing mortality in hamsters challenged with Pichinde virus (PICV, Arenavirus), an infection characterized as diffuse and pantropic. Remarkably, T-1106 has proven more active in vivo than would have been expected from our cell culture results, and our in vivo findings suggest that it is more effective in infections characterized predominantly by high levels of hepatic viral burden. PMID- 19874851 TI - Development of topical microbicides to prevent the sexual transmission of HIV. AB - Women comprise almost 50% of the population of people living with HIV and the majority of these women contracted the virus through sexual transmission in monogamous relationships in the developing world. In these environments, where women are not empowered to protect themselves through the negotiation of condom use, effective means of preventing HIV transmission are urgently needed. In the absence of an approved and effective vaccine, microbicides have become the strategy of choice to provide women with the ability to prevent HIV transmission from their infected partners. Topical microbicides are agents specifically developed and formulated for use in either the vaginal or rectal environment that prevent infection by sexually transmitted infectious organisms, including pathogenic viruses, bacteria and fungi. Although a microbicidal product will have many of the same properties as other anti-infective agents and would be similarly developed through human clinical trials, microbicide development bears its own challenges related to formulation and delivery and the unique environment in which the product must act, as well as the requirement to develop a product that is acceptable to the user. Herein, perspectives based on preclinical and clinical microbicide development experience, which have led to an evolving microbicide development algorithm, will be discussed. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of anti-retroviral drug discovery and development, Vol 85, issue 1, 2010. PMID- 19874854 TI - The effects of BDNF Val66Met polymorphism on brain function in controls and patients with multiple sclerosis: an imaging genetic study. AB - Relatively little is known about genetic determinants of cognitive dysfunction in multiple sclerosis (MS). A growing body of evidence demonstrates that a functional variant of the brain-derived neurotrophic factor (BDNF) gene, the Val(66)Met polymorphism, contributes to poor hippocampal and prefrontal functions, particularly memory processes, in healthy controls. In contrast, findings from previous association studies examining this polymorphism and memory performance in MS patients yielded conflicting results. However, the way in which this BDNF polymorphism affects brain function in MS patients has not been examined. In line with the "intermediate phenotype" approach, we assessed effects of the BDNF Val(66)Met polymorphism on brain activity during a spatial working memory task. We used functional magnetic resonance imaging (fMRI) to measure brain responses in a total of 61 subjects comprising 29 relapsing-remitting MS patients and 32 healthy controls. The fMRI results demonstrated association of the BDNF polymorphism with brain activity during working memory, with opposite effects in MS patients and controls. Healthy carriers of the Met(66) allele showed increased activation of the parieto-prefrontal network and altered disengagement of the ventro-medial prefrontal cortex and hippocampus in comparison with their respective Val(66) counterparts. Analysis within the group demonstrated that this working memory-related activation pattern was absent in MS patients. Our imaging genetic study demonstrates that the Val(66)Met polymorphism of the BDNF gene contributes to some of the individual variability in the functional response to a working memory challenge in healthy controls but it does not provide evidence for an MS-specific pattern of gene action. PMID- 19874855 TI - Species differences in group size and electrosensory interference in weakly electric fishes: implications for electrosensory processing. AB - In animals with active sensory systems, group size can have dramatic effects on the sensory information available to individuals. In "wave-type" weakly electric fishes there is a categorical difference in sensory processing between solitary fish and fish in groups: when conspecifics are within about 1m of each other, the electric fields mix and produce interference patterns that are detected by electroreceptors on each individual. Neural circuits in these animals must therefore process two streams of information-salient signals from prey items and predators and social signals from nearby conspecifics. We investigated the parameters of social signals in two genera of sympatric weakly electric fishes, Apteronotus and Sternopygus, in natural habitats of the Napo River valley in Ecuador and in laboratory settings. Apteronotus were most commonly found in pairs along the Napo River (47% of observations; maximum group size 4) and produced electrosensory interference at rates of 20-300 Hz. In contrast, Sternopygus were alone in 80% of observations (maximum group size 2) in the same region of Ecuador. Similar patterns were observed in laboratory experiments: Apteronotus were in groups and preferentially approached conspecific-like signals in an electrotaxis experiment whereas Sternopygus tended to be solitary and did not approach conspecific-like electrosensory signals. These results demonstrate categorical differences in social electrosensory-related activation of central nervous system circuits that may be related to the evolution of the jamming avoidance response that is used in Apteronotus but not Sternopygus to increase the frequency of electrosensory interference patterns. PMID- 19874856 TI - Crystal structure of the aspartyl-tRNA synthetase from Entamoeba histolytica. AB - The crystal structure of the aspartyl-tRNA synthetase from the eukaryotic parasite Entamoeba histolytica has been determined at 2.8Aresolution. Relative to homologous sequences, the E. histolytica protein contains a 43-residue insertion between the N-terminal anticodon binding domain and the C-terminal catalytic domain. The present structure reveals that this insertion extends an arm of the hinge region that has previously been shown to mediate interaction of aspartyl tRNA synthetase with the cognate tRNA D-stem. Modeling indicates that this Entamoeba-specific insertion is likely to increase the interaction surface with the cognate tRNA(Asp). In doing so it may substitute functionally for an RNA binding motif located in N-terminal extensions found in AspRS sequences from lower eukaryotes but absent in Entamoeba. The E. histolytica AspRS structure shows a well-ordered N-terminus that contributes to the AspRS dimer interface. PMID- 19874857 TI - Cloning and bioinformatic identification of small RNAs in the filarial nematode, Brugia malayi. AB - Characterization of small RNAs from the filarial nematode Brugia malayi is the initial step in understanding their role in gene silencing. Both RNA cloning and bioinformatics were used to identify 32 microRNAs (miRNAs) belonging to 24 families. One family, miR-36 only occurs in helminths including B. malayi. Several of the miRNAs are arranged in clusters and are coordinately expressed as determined by northern blot analysis. In addition, small RNAs were identified from Pao/Bleo retrotransposons and their associated repeat sequences indicating that B. malayi uses an RNAi mechanism to maintain genome integrity. Analysis of these data provides a first glimpse into how small RNA-mediated silencing pathways regulate the parasitic life cycle of B. malayi. PMID- 19874858 TI - Well-defined block copolymers for gene delivery to dendritic cells: probing the effect of polycation chain-length. AB - The development of safe and efficient polymer carriers for DNA vaccine delivery requires mechanistic understanding of structure-function relationship of the polymer carriers and their interaction with antigen-presenting cells. Here we have synthesized a series of diblock copolymers with well-defined chain-length using atom transfer radical polymerization and characterized the influence of polycation chain-length on the physico-chemical properties of the polymer/DNA complexes as well as the interaction with dendritic cells. The copolymers consist of a hydrophilic poly(ethylene glycol) block and a cationic poly(aminoethyl methacrylate) (PAEM) block. The average degree of polymerization (DP) of the PAEM block was varied among 19, 39, and 75, with nearly uniform distribution. With increasing PAEM chain-length, polyplexes formed by the diblock copolymers and plasmid DNA had smaller average particle size and showed higher stability against electrostatic destabilization by salt and heparin. The polymers were not toxic to mouse dendritic cells (DCs) and only displayed chain-length-dependent toxicity at a high concentration (1mg/mL). In vitro gene transfection efficiency and polyplex uptake in DCs were also found to correlate with chain-length of the PAEM block with the longer polymer chain favoring transfection and cellular uptake. The polyplexes induced a modest up-regulation of surface markers for DC maturation that was not significantly dependent on PAEM chain-length. Finally, the polyplex prepared from the longest PAEM block (DP of 75) achieved an average of 20% enhancement over non-condensed anionic dextran in terms of uptake by DCs in the draining lymph nodes 24h after subcutaneous injection into mice. Insights gained from studying such structurally well-defined polymer carriers and their interaction with dendritic cells may contribute to improved design of practically useful DNA vaccine delivery systems. PMID- 19874859 TI - Size and shape effects in the biodistribution of intravascularly injected particles. AB - Understanding how size and shape can affect the biodistribution of intravascularly injected particles is of fundamental importance both for the rational design of delivery systems and from a standardization and regulatory view point. In this work, uncoated silica spherical beads, with a diameter ranging from 700 nm to 3 microm, and uncoated non-spherical silicon-based particles, with quasi-hemispherical, cylindrical and discoidal shapes, have been injected into tumor bearing mice. The number of particles accumulating in the major organs and within the tumor mass has been measured through elemental silicon (Si) analysis. For the spherical beads, it has been found that the number of particles accumulating in the non-RES organs reduces monotonically as the diameter d increases, suggesting the use of smaller particles to provide a more uniform tissue distribution. However, discoidal particles have been observed to accumulate more than others in most of the organs but the liver, where cylindrical particles are deposited at a larger extent. These preliminary results support the notion of using sub-micrometer discoidal particles as intravascular carriers to maximize accumulation in the target organ whilst reducing sequestration by the liver. PMID- 19874860 TI - Liposomes based on dimethyldioctadecylammonium promote a depot effect and enhance immunogenicity of soluble antigen. AB - The mechanism behind the immunostimulatory effect obtained with the cationic liposomal vaccine adjuvant DDA:TDB remains unclear. One of the proposed hypotheses is the 'depot effect' in which the liposomal carrier helps to retain the antigen at the injection site thereby increasing the time of vaccine exposure to the immune cells. In the present study we devise a method to quantify the in vivo movement of liposomes and vaccine antigen using the radioisotopes H(3) and I(125) respectively. H(3)-labeled liposomes composed of dimethyldioctadecylammonium bromide (DDA) or an 8:1 molar ratio of DDA and trehalose 6,6-dibehenate (TDB) were administered in combination with I(125) labeled Ag85B-ESAT-6 antigen, both via intramuscular and subcutaneous injection to mice. Furthermore characterisation of the liposomal system in simulated in vivo conditions was undertaken. Our results show that this dual-labeling technique is functional and reproducible. The administration of Ag85B-ESAT-6 without a liposomal carrier leads to rapid dissemination of the antigen from the site of injection. The administration of Ag85B-ESAT-6 together with either DDA or DDA:TDB liposomes however leads to deposition of the antigen at the injection site with detectable levels still being present 14 days post injection. Neither the incorporation of TDB nor the route of injection had any significant influence on the depot effect of DDA-based liposomes. The presence of TDB in DDA liposomes improves draining of liposomes to the lymph node in addition to increasing monocyte influx to the site of injection as highlighted by the intensive blue colouring of the injection site after pontamine blue staining of phagocytic cells in vivo. Our findings provide conclusive evidence for a cationic liposome mediated deposition of antigen at the injection site with improved monocyte infiltration. PMID- 19874861 TI - An overview of liposome lyophilization and its future potential. AB - Lyophilization is a promising approach to ensure the long-term stability of liposomes. After decades of studies in this field, different lyoprotective mechanisms, such as water replacement and vitrification models, have been proposed. Much progress has been made in developing highly stable liposomes after lyophilization based on optimization of formulation and process parameters. Here, this paper reviews the lyoprotective mechanisms, the parameters affecting the lyoprotective effect and the techniques used in a large number of studies. The parameters are discussed with regard to the following two aspects: (1) the formulation factors: the choice of drug, the lipid bilayer composition, vesicle size, selection of lyoprotectants, combination of lyoprotectants and additives, dry mass ratio of lyoprotectant to lipid, distribution of lyoprotectant on the two sides of lipid bilayers and others, which are the key factors determining the lyoprotective effect of freeze-dried liposomes. (2) The technological factors: freezing protocols, drying protocols, storage conditions and others, which are the extrinsic factors affecting the stability of freeze-dried cakes. Moreover, encapsulated solute/drug retention (ESR), gel-to-liquid crystalline phase transition temperature (T(m)) and glass transition temperature (T(g)) are selected as indicators to investigate the protective effect during this process. Finally, the major areas and future potential of research on lyophilized liposomes are highlighted. PMID- 19874862 TI - Targeted delivery of low molecular drugs using chitosan and its derivatives. AB - Chitosan has prompted the continuous impetus for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resulting amphiphile may form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site of action. Chemical attachment of the drug to the chitosan throughout the functional linker may produce useful prodrugs, exhibiting the appropriate biological activity at the target site. Mucoadhesive and absorption enhancement properties of chitosan increase the in vivo residence time of the dosage form in the gastrointestinal tract and improve the bioavailability of various drugs. The main objective of this review is to provide an insight into various target-specific carriers, based on chitosan and its derivatives, towards low molecular weight drug delivery. The first part of the review is concerned with the organ-specific delivery of low molecular drugs using chitosan and its derivatives. The subsequent section considers the recent developments of drug delivery carriers for cancer therapy with special focus on various targeting strategies. PMID- 19874863 TI - Importance of extracellular loop one of the neuropeptide S receptor for biogenesis and function. AB - Neuropeptide S (NPS) is the endogenous ligand of a formerly orphan G protein coupled receptor (GPCR). The NPS receptor (NPSR) belongs to the subfamily of peptide GPCRs and is widely expressed in the brain. NPS promotes arousal and induces anxiolytic-like effects after central administration in rodents. Previously, we have reported that the N107I polymorphism in the human NPS receptor results in a gain-of-function characterized by an increase in agonist potency without changing agonist binding affinity. We have extended our findings by investigating pharmacological and biochemical consequences of mutations in the vicinity of position 107. Alanine substitutions were made for D105 and N101, and stable clones were analyzed for agonist-induced changes of intracellular Ca(2+). Receptor protein expression was monitored by Western blot and flow cytometry. The mutation D105A produced receptors that have a approximately 200-fold higher EC(50) despite elevated total receptor protein and surface expression compared to cell lines expressing the parental receptor NPSR-N107. The mutation N101A resulted in slightly reduced agonist potency without affecting the ability of the protein to form functional receptors. Stable NPSR-A101 clones show little expression of the fully glycosylated form. However, NPSR-A101 receptors are expressed on the cell surface and are functional, suggesting that full glycosylation is not required for receptor function. Our studies suggest that N linked glycosylation is not important for receptor biogenesis or function, and that residue D105 might be critical for receptor binding. PMID- 19874864 TI - Aqueous extract of Phyllanthus amarus inhibits chromium(VI)-induced toxicity in MDA-MB-435S cells. AB - Cr(VI) (hexavalent) is a very strong oxidant which causes high cytotoxicity through oxidative stress in tissue systems. Its abundance in groundwater and drinking water in several parts of the world has been noted to cause severe toxicity to both flora and fauna. This study evaluated the effects of aqueous extract of Phyllanthus amarus Schum. & Thon. against Cr(VI)-induced oxidative toxicity in vitro in MDA-MB-435S human breast carcinoma cells, along with an estimation of its antioxidant potential, inhibition of lipid peroxidation and determination of its polyphenolic composition. The extract showed significant (P<0.05) potential in scavenging free radicals (DPPH() and ABTS()(+)) and Fe(+3), and in inhibiting lipid peroxidation. A distinct decline in Cr(VI)-induced cytotoxicity was noticed in MDA-MB-435S cells with an increase in extract dosage. Furthermore, the extract proved to contain a high content of phenolic compounds which were found to have strong and significant (P<0.05) positive correlations to free-radical scavenging potential, lipid peroxidation inhibition capacity and cyto-protective efficiency against Cr(VI)-induced oxidative cellular damage. HPLC analysis identified some of the major phenolic compounds in it. It was concluded that P. amarus aqueous extract has high antioxidant potential (by virtue of its phenolic constituents) which simultaneously inhibits Cr(VI)-induced oxidative toxicity to MDA-MB-435S cells. PMID- 19874865 TI - Selection advantage of metabolic over non-metabolic replicators: a kinetic analysis. AB - A kinetic analysis and simulation of the replication reactions of two competing replicators-one non-metabolic (thermodynamic), the other metabolic, are presented. Our analysis indicates that in a rich resource environment the non metabolic replicator is likely to be kinetically selected for over the metabolic replicator. However, in the more typical resource-poor environment it will be the metabolic replicator that is the kinetically more stable entity, and the one that will be kinetically selected for. Accordingly, a causal relationship between the emergence of a simple replicator and the emergence of a metabolic system is indicated. The results lend further support for the "replication first" school of thought in the origin of life problem by providing a mechanistic basis for the emergence of a metabolism, once a simple non-metabolic replicating system has itself been established. The study reaffirms our view that the roots of Darwinian theory may be found within standard chemical kinetic theory. PMID- 19874866 TI - Neurotrophin-4 couples to locally modulated ACh release at the end of neuromuscular synapse maturation. AB - We use immunocytochemistry to show that neurotrophin-4 (NT-4) and its receptor proteins (p75(NTR) and tropomyosin-related tyrosine kinase B) are present in neonatal neuromuscular junctions (NMJ) colocalized with several synaptic markers. NT-4 incubation (1h, in the range 2-12 nM) does not change the size of the endplate potential between P6 and P45. However, extended exposure (3h) to a relatively low dose of NT-4 (2 nM) potentiates ACh release (approx. 70%) in adult but not in neonatal muscles. The present results suggest that the developmental mechanism of axonal competition and neonatal elimination of redundant synapses cannot be modulated by added NT-4. However, this neurotrophin was able to modulate synaptic transmission locally in the adult NMJ. PMID- 19874867 TI - Oral administration of L-serine reduces the locomotor activity of socially isolated rats. AB - L-Serine is considered a functional amino acid in the central nervous system, since intracerebroventricular injection of L-serine induced sedative and hypnotic effects in neonatal chicks exposed to acute stressful conditions. Accordingly, L serine is a candidate anti-stress factor, but the effect of daily intake of L serine on behavior of animals exposed to chronic stress has not been investigated. In the present study, we exposed rats to social isolation stress for 4 weeks, and home cage test and open field test were concluded to evaluate the effect of L-serine on behavior. To investigate L-serine supplementation modifies the brain L-serine and its metabolite contents, free amino acid contents were measured by a high performance liquid chromatography. L-Serine in the drinking water increased L-serine levels in some brain areas, but changes in its metabolites were almost negligible. L-Serine decreased locomotor activity in rats exposed to a familiar environment. In addition, L-serine decreased exploratory behavior of isolated rats, even in a novel environment. Our results could suggest that daily intake of L-serine can attenuate symptoms induced by chronic stress. PMID- 19874868 TI - TPH1 218A/C polymorphism is associated with major depressive disorder and its treatment response. AB - The association between the tryptophan hydroxylase 1 (TPH1) 218A/C polymorphism and (1) severity of major depressive disorder (MDD) and (2) response to treatment was studied. There were three study populations, the first consisting of 119 treatment-resistant MDD inpatients treated with electro-convulsive therapy (ECT), and the second of 98 MDD open care patients treated with selective serotonin reuptake inhibitors (SSRI). In addition, there was a control population of 395 healthy blood donors. The first aim of the study was to compare the genotypes of the patient with those of the healthy controls and between patient populations. The second aim was to compare the genotypes of MDD patients achieving remission with basic SSRI treatment (MADRS<8) with the genotypes of non-responders to ECT (defined as MADRS>15). TPH1 218A/C polymorphism was associated with the risk of MDD. CC genotype was significantly more common in patients (including both ECT and SSRI treated patients) than in controls (38.2% and 26.8% respectively; p=0.008), and its frequency was significantly higher in more severe forms of depression, i.e. in ECT treated patients compared with SSRI treated patients (42.0% and 33.7%, p=0.026). CC genotype was also associated with lower probability of achieving remission. It was significantly more frequent among ECT non-responders than among SSRI remitters (53.1% and 23.3%, p=0.049). In this Finnish population TPH1 218A/C polymorphism was associated with the risk of MDD and treatment response; CC genotype was associated with the increased risk of MDD and lower probability of responding treatment. Further studies with larger samples will be required to confirm the results. PMID- 19874869 TI - Early interaction between perceptual load and involuntary attention: An event related potential study. AB - Whether selective attention affects C1, the first (earliest) visual cortical component of the event-related potential (ERP), remains controversial. We used a cued, involuntary attention task requiring discrimination of targets under low and high levels of perceptual load to examine early attentional modulation in visual cortex. Potential confounds due to physical stimulus differences between load conditions and cue-target sensory interaction were minimized. An interaction between perceptual load and involuntary attention was observed for the P1m component (peak latency between 100 and 140 ms). Furthermore, the parieto-central C1 component (peak latency 80 ms) was modulated by attention, but only under the high-load condition. Thus, whereas attention typically modulates the later P1 component, attentional modulation of C1 is possible under optimal conditions. Specifically, a high perceptual load is necessary for eliciting this earliest attentional effect on cortical processing. PMID- 19874870 TI - Clinical and medial temporal features in a family with mood disorders. AB - It is debated whether non-affected relatives of patients with affective disorders share a specific brain structure endophenotype. Aim of this work is to explore the medial temporal morphology in affected and non-affected members of a family with mood disorders. Hippocampi and amygdalae were manually traced from the 3D magnetic resonance imaging of five affected family members, 10 non-affected relatives, and 15 unrelated matched controls. Affected and non-affected relatives were characterized by larger left amygdalae (18%, p=0.030), smaller right hippocampus (up to 18%, p<0.0005), and reduced hippocampal asymmetry (p<0.001) than controls. Abnormal, albeit non significant, positive correlations of MTL volumes with age were observed, with the exception of smaller volume of the left hippocampus with advancing age (r=-0.76) in the affected relatives. These data add to the evidence that abnormal medial temporal structures may constitute an endophenotype for affective disorders. PMID- 19874871 TI - Upregulated expression of oncomodulin, the beta isoform of parvalbumin, in perikarya and axons in the diencephalon of parvalbumin knockout mice. AB - The calcium-binding proteins parvalbumin, calbindin D-28k, calretinin and calcineurin are present in subsets of GABAergic gigantic calyciform presynaptic terminals of the reticular thalamic nucleus (RTN). Previously it was hypothesized that GABA and calcium-binding proteins including parvalbumin are not only colocalized in the same neuron subpopulation, but that GABA synthesis and parvalbumin expression could be also genetically regulated by a common mechanism. Moreover, parvalbumin expression levels could influence GABA synthesis. For this, we analyzed GABA immunoreactivity in RTN gigantic calyciform presynaptic terminals of parvalbumin-deficient (PV-/-) mice. With respect to GABA immunoreactivity we found no differences compared to wild-type animals. However, using a polyclonal parvalbumin antibody raised against full-length rat muscle parvalbumin on brain sections of PV-/- mice, we observed paradoxical parvalbumin immunoreactivity in partly varicose axons in the diencephalon, mainly in the lamina medullaris externa surrounding the thalamus. A detailed immunohistochemical, biochemical and molecular biological analysis revealed this immunoreactivity to be the result of an upregulation of oncomodulin (OM), the mammalian beta isoform of parvalbumin in PV-/- mice. In addition, OM was present in a sparse subpopulation of neurons in the thalamus and in the dentate gyrus. OM expression has not been observed before in neurons of the mammalian brain; its expression was restricted to outer hair cells in the organ of Corti. Our results indicate that the absence of parvalbumin has no major effect on the GABA synthesizing system in RTN presynaptic terminals excluding a direct effect of parvalbumin on this regulation. However, a likely homeostatic mechanism is induced resulting in the upregulation of OM in selected axons and neuronal perikarya. Our results warrant further detailed investigations on the putative role of OM in the brain. PMID- 19874872 TI - Activation of extracellular signal-regulated kinases in social behavior circuits during resident-intruder aggression tests. AB - Using a variety of experimental methods, a network of brain areas regulating aggressive behaviors has been identified in several groups of vertebrates. However, aggressive behavior expressed in different contexts is associated with different patterns of activity across hypothalamic and limbic brain regions. Previous studies in rodents demonstrated that short day photoperiods reliably increase both male and female aggression versus long day photoperiods. Here we used immunohistochemistry and western blots to examine the effect of photoperiod on phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK) in male California mice (Peromyscus californicus) during resident-intruder tests. Phosphorylated ERK (pERK) can alter neuronal activity in the short term and in the long term acts as a transcription factor. In the posterior bed nucleus of the stria terminalis (BNST) males tested in aggression tests had more pERK positive cells when housed in short days but not long days. This result was replicated in western blot analyses from microdissected BNST samples. In the medial amygdala (MEA), immunostaining and western analyses showed that pERK expression also was generally increased in short days. Immunostaining was also used to examine phosphorylation of cyclic AMP response element binding protein (CREB). CREB can be phosphorylated by pERK as well as other kinases and functions primarily as a transcription factor. Intriguingly, aggressive interactions reduced the number of cells stained positive for phosphorylated CREB in the infralimbic cortex, ventral lateral septum and MEA. This effect was observed in mice housed in long days but not short days. Overall, these data suggest that different (but overlapping) networks of aggressive behavior operate under different environmental conditions. PMID- 19874874 TI - Hypothalamic gonadotropin-releasing hormone receptor activation stimulates oxytocin release from the rat hypothalamo-neurohypophysial system while melatonin inhibits this process. AB - The present study was undertaken to investigate the influence of gonadotropin releasing hormone (GnRH) and its agonist and antagonist on oxytocin (OT) release from the rat hypothalamo-neurohypophysial (H-N) system. An additional aim was to determine whether the possible response of oxytocinergic neurons to these peptides could be modified by melatonin through a cAMP-dependent mechanism. The results show that the highly selective GnRH agonist (i.e., [Des-Gly(10),d His(Bzl)(6),Pro-NHEt(9)]-LHRH; Histrelin) stimulates the secretion of OT from an isolated rat H-N system. Melatonin significantly inhibited basal and histrelin induced release of OT in vitro, and displayed no significant influence on OT release in the presence of GnRH or its antagonist. Addition of melatonin to a medium containing forskolin resulted in significant reduction of OT secretion from the H-N system. On the other hand, addition of forskolin to a medium containing both histrelin and melatonin did not further alter the inhibitory influence of melatonin on the histrelin-dependent secretion of OT in vitro. Intracerebroventricular (icv) infusion (experiment in vivo) of a GnRH antagonist resulted in substantial inhibition of OT release, thus revealing the stimulatory action of endogenous GnRH. In melatonin-treated animals, blood plasma OT levels were not changed in comparison to the vehicle. Our present data strongly suggests that activation of the GnRH receptor in the hypothalamus is involved in stimulation of OT secretion from the rat H-N system. It has also been shown, under experimental in vitro conditions, that melatonin fully suppresses the response of oxytocinergic neurons to the GnRH agonist - histrelin. The effect of melatonin on OT release is mediated by the cAMP-dependent mechanism, although other mechanisms of action are also possible. PMID- 19874873 TI - Contralateral paw sensitization following injection of endothelin-1: effects of local anesthetics differentiate peripheral and central processes. AB - Subcutaneous injection of the peptide endothelin-1 (ET-1) into the rat's footpad is known to cause rapid, transient ipsilateral mechanical and thermal sensitization and nocifensive hind paw flinching. Here we report that local injection of ET-1 (2 nmoles) into one hind paw slowly sensitizes the contralateral paw to chemical and mechanical stimulation. There was a 1.5-2-fold increase in the hind paw flinching response, over that from the first injection, to a second injection of the same dose of ET-1 delivered 24 h later into the contralateral paw. A similar increase in the number of flinches during the second phase of the response to formalin also occurred in the contralateral paw 24 h after ET-1. The contralateral paw withdrawal threshold to von Frey hairs was lowered by approximately 55% at 24 h after ipsilateral ET-1 injection. ET-1 injected s.c. at a segmentally unrelated location, the nuchal midline, caused no sensitization of the paws, obviating a systemic route of action. Local anesthetic block of the ipsilateral sciatic nerve during the period of initial response to ipsilateral ET-1 prevented contralateral sensitization, indicating the importance of local afferent transmission, although ipsilateral desensitization was not changed. These findings suggest that peripheral ET-1 actions lead to central sensitization that alters responses to selected stimuli. PMID- 19874875 TI - Chemical composition of the Lippia origanoides essential oils and their antigenotoxicity against bleomycin-induced DNA damage. AB - The present work evaluated the chemical composition of the essential oils (EO) obtained from Lippia origanoides and their DNA protective effect against bleomycin-induced genotoxicity. L. origanoides EO chemical composition was determined by gas chromatography-mass spectrometry (GC-MS). The major compounds of the L. origanoides EOs were thymol (34-58%) and carvacrol (26%). The antigenotoxic effects of the EOs, major compounds and standard compound (epigallocatechin gallate) were assayed in co-incubation procedures using the SOS chromotest in Escherichia coli. Both EOs and their major compounds protected bacterial cells against bleomycin-induced genotoxicity indicating that these two compounds were principally responsible for the antigenotoxicity detected in the oils. Thymol and carvacrol antigenotoxicity was lower than those observed with epigallocatechin gallate. The results were discussed in relation to the chemopreventive potential of L. origanoides EOs and their major components, carvacrol and thymol. PMID- 19874876 TI - Object familiarization and novel-object preference in rats. AB - We investigated whether object familiarization was related to novel-object preference in the novel-object preference (NOP) test in rats. In Experiment 1, we found that no significant correlation existed between the time spent investigating 2 identical copies of a sample object and the degree of preference for a novel object. In Experiment 2, rats investigated 2 identical sample objects for a total of 5, 30, 60, 90 or 120s. Investigatory preference for the novel object was compared to chance expectancy as well as between the groups. Only the 90-s group and the 120-s group displayed above-chance investigatory preference for the novel object, but novel-object preference for these 2 groups did not differ from each other, suggesting that a minimal amount of sample object investigation is necessary for rats to develop a novel-object preference, beyond which no increase in novel-object preference was found. In Experiments 3 and 4, normal rats and rats with hippocampal lesions were given repeated test trials, with the same sample object presented with a different novel object, at 24-h and (Experiment 3) and 35-s intervals (Experiment 4). In both experiments, novel object preference did not increase in magnitude with repeated sample object exposures, suggesting that increased familiarity with the sample object does not result in increased novel-object preference. Rats with lesions of the dorsal hippocampus showed an unreliable investigatory preference for the novel object. These results are discussed in terms of the potential limitations of the NOP test as a tool for the assessment of object-recognition memory in rats. PMID- 19874877 TI - Transcutaneous delivery of a nanoencapsulated antigen: induction of immune responses. AB - We investigated the influence of antigen entrapment in PLA nanoparticles on the immune responses obtained after transcutaneous immunization. OVA-loaded PLA nanoparticles were prepared using a double emulsion process. Following application onto bare skin of mice in vivo, fluorescence-labeled nanoparticles were detected in the duct of the hair follicles indicating that the nanoparticles can penetrate the skin barrier through the hair follicles. Although the OVA loaded nanoparticles elicited lower antibody responses than those induced by OVA in aqueous solution they were more efficient in inducing cytokine responses. In vitro re-stimulation of cultured splenocytes with OVA elicited a little higher levels of IFN-gamma (difference statistically insignificant, p>0.05) and significantly higher levels of IL-2 (p<0.001) in mice immunized with OVA-loaded nanoparticles compared to those immunized with OVA in solution. In the presence of CT, the OVA-loaded nanoparticles induced significantly higher IFN-gamma and IL 2 than all other formulations. Transcutaneous administration of OVA encapsulated in the PLA nanoparticles exhibited priming efficacy to a challenging dose of OVA given via different route. These findings indicate the potential of nanoparticles to deliver antigens via the transcutaneous route and prime for antibody and strong cellular responses. The co-administration of an adjuvant such as CT had the added advantage of modulating the immune response, a desirable characteristic within the context of vaccination against intracellular versus extracellular pathogens. PMID- 19874878 TI - Separation of major catechins from green tea by ultrahigh pressure extraction. AB - This study presents a novel extraction technique, ultrahigh pressure extraction, to obtain major catechins from green tea leaves. The effects of various high pressure level (100, 200, 300, 400, 500, 600 MPa) on the extract are examined. HPLC chromatographic analyses determine the concentration of four major catechins and caffeine. The extraction yields of active ingredients with ultrahigh pressure extraction (400 MPa pressure) for only 15 min were given the same as those of organic solvent extraction for 2h. These excellent results for the ultrahigh pressure extraction are promising for the future separation of active ingredients from traditional Chinese herbal medicine. PMID- 19874879 TI - PEI-alginate nanocomposites: efficient non-viral vectors for nucleic acids. AB - Branched polyethylenimine (PEI, 25 kDa) was ionically interacted with varying amount of alginic acid to block different proportion (2.6-5.7%) of amines in PEI to form a series of nanocomposites, PEI-Al. These nanocomposites, upon interaction with DNA, protected it against DNase I. Among various complexes evaluated, PEI-Al(4.8%)/DNA displayed the highest transfection efficiency in HEK293, COS-1 and HeLa cells that was approximately 2-8-folds higher than Superfect, Fugene, PEI (750 kDa)-Al(6.26%) and PEI alone. The projected nanocomposites were nearly non-toxic to cells in vitro. Furthermore, the concentration of PEI-Al(4.8%) needed to deliver GFP-specific siRNA in COS-1 cells was 20 times lower than PEI (750 kDa)-Al(6.26%). Intracellular trafficking of PEI Al(4.8%) with or without complexed DNA in HeLa cells shows that both appear in the nucleus after 1 h. PMID- 19874880 TI - Targeted antifungal delivery system: beta-glucosidase sensitive nystatin-star poly(ethylene glycol) conjugate. AB - A new targeted intravenous conjugate of nystatin with pentaerythritol poly(ethylene glycol)ether has been prepared and characterised (NY(4)-sPEG, M=25 160). The conjugate contains a beta-d-glucopyranoside molecular switch sensitive to beta-glucosidases (E.C.3.2.1.21), which are specifically present in the enzyme outfit of fungal pathogens. The investigated conjugate is stable under in vitro conditions for 24h (solution of phosphate buffer pH=7.4). Spectrophotometrically controlled releasing of nystatin in model medium containing beta-glucosidase ((Aspergillus niger) 2mg/mL, 66.6 units/g; pH 7.4, 2 x 10(-2)M), reported decomposition half-life of conjugate tau(1/2)=(88+/-2)s. This implies that releasing of nystatin is controlled only enzymatically. PMID- 19874881 TI - Hepatoprotective activity of ethanolic extracts of bark of Zanthoxylum armatum DC in CCl4 induced hepatic damage in rats. AB - AIM OF THE STUDY: Zanthoxylum armatum DC is described as a hepatoprotective in Ayurveda, the Indian system of medicine. However, there is no scientific basis or reports in the modern literature regarding its usefulness as a hepatoprotective agent. The present study was carried out to evaluate the hepatoprotective activity of ethanolic extract of bark of Zanthoxylum armatum DC in CCl(4) induced hepatotoxicity in male Wistar rats. MATERIALS AND METHODS: Ethanolic extracts at doses of 100, 200, and 400mg/kg were administered orally once daily for 7 days. The hepatoprotective activity was assessed using various biochemical parameters like alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum bilirubin, total protein and serum antioxidant enzymes along with histopathological studies of liver tissue. RESULTS: The substantially elevated serum enzymatic levels of serum transaminases, alkaline phosphatase and total bilirubin were significantly restored towards normalization by the extracts. Bark extracts significantly increased the levels of antioxidant enzymes: superoxide dismutase, catalase and glutathione. Phytochemical analysis revealed presence of isoquinoline alkaloid, berberine, as well as flavonoids and phenolic compounds, which have been known for their hepatoprotective activities. CONCLUSIONS: Zanthoxylum armatum DC possesses significant protective effect against hepatotoxicity induced by CCl(4) which may be attributed to the individual or combined action of phytoconstituents present in it. PMID- 19874882 TI - Ethnobotanical and phytomedicinal knowledge in a long-history protected area, the Abruzzo, Lazio and Molise National Park (Italian Apennines). AB - AIMS OF THE STUDY: This study reports on the ethnobotanical and phytomedical knowledge in one of the oldest European Parks, the Abruzzo, Lazio and Molise National Park (Central Italy). We selected this area because we judged the long history of nature preservation as an added value potentially encouraging the survival of uses possibly lost elsewhere. METHODOLOGY: In all, we interviewed 60 key informants (30 men and 30 women) selected among those who, for their current or past occupation or specific interests, were most likely to report accurately on traditional use of plants. The average age of informants was 65 years (range 27-102 years). RESULTS: The ethnobotanical inventory we obtained included 145 taxa from 57 families, corresponding to 435 use-reports: 257 referred to medical applications, 112 to food, 29 to craft plants for domestic uses, 25 to veterinary applications, 6 to harvesting for trade and another 6 to animal food. The most common therapeutic uses in the folk tradition are those that are more easily prepared and/or administered such as external applications of fresh or dried plants, and decoctions. Of 90 species used for medical applications, key informants reported on 181 different uses, 136 of which known to have actual pharmacological properties. Of the uses recorded, 76 (42%) concern external applications, especially to treat wounds. Medical applications accounted for most current uses. Only 24% of the uses we recorded still occur in people's everyday life. Species no longer used include dye plants (Fraxinus ornus, Rubia tinctorum, Scabiosa purpurea, Rhus coriaria and Isatis tinctoria) and plants once employed during pregnancy, for parturition, nursing, abortion (Asplenium trichomanes, Ecballium elaterium, Juniperus sabina and Taxus baccata) or old magical practices (Rosa canina). CONCLUSIONS: Our study remarked the relationship existing between the high plant diversity recorded in this biodiversity hotspot of central Apennines and the rich ethnobotanical knowledge. The presence of some very experienced young informants was related to the opportunities offered by living in a major protected area. However, to counter the disappearance of local ethnobotanical culture it would be important to incorporate its preservation among nature reserve activities. PMID- 19874883 TI - Conserved methylation of the glucocorticoid receptor gene exon 1(7) promoter in rats subjected to a maternal methyl-supplemented diet. AB - It is well known that the early life experiences affect stress responses and other physiological and behavioral traits in adulthood. Both rat and human studies have shown that early postnatal effects are associated with methylation of the hippocampal glucocorticoid receptor gene exon 1(7) (rat) and 1-F (human) promoters. Methylation of these sites is also seen following methionine administration in adult rats. However, it remains unclear whether similar alterations in DNA methylation profiles can result from prenatal influences. To address this question, we fed pregnant rats a methyl-supplemented diet that resulted in alteration of the stress response. However, methylation analysis revealed no effect of methyl supplements on methylation patterns of the glucocorticoid receptor gene exon 1(7) promoter in offspring. These results suggest that the pre- and postnatal effects of methyl supplementation have different mechanisms. PMID- 19874884 TI - Transcriptional profiling reveals genes in the human pathogen Trichophyton rubrum that are expressed in response to pH signaling. AB - Trichophyton rubrum is a dermatophyte that infects human skin and nails. Its growth on keratin as its carbon source shifts the ambient pH from acidic to alkaline, which may be an efficient strategy for its successful infection and maintenance in the host. In this study, we used suppression subtractive hybridization to identify genes preferentially expressed in T. rubrum incubated at either pH 5.0 or pH 8.0. The functional grouping of the 341 overexpressed unigenes indicated proteins putatively involved in diverse cellular processes, such as membrane remodeling, cellular transport, metabolism, cellular protection, fungal pathogenesis, gene regulation, interaction with the environment, and iron uptake. Although the basic metabolic machinery identified under both growth conditions seems to be functionally similar, distinct genes are upregulated at acidic or alkaline pHs. We also isolated a large number of genes of unknown function, probably unique to T. rubrum or dermatophytes. Interestingly, the transcriptional profiling of several genes in a pacC(-) mutant suggests that, in T. rubrum, the transcription factor PacC has a diversity of metabolic functions, in response to either acidic or alkaline ambient pH. PMID- 19874885 TI - A mutation in gene CNGA3 is associated with day blindness in sheep. AB - Lambs with congenital day blindness show diminished cone function, which is characteristic of achromatopsia, a congenital disorder described in humans and dogs. To identify gene(s) associated with sheep day blindness, we investigated mutations in the CNGA3, CNGB3, and GNAT2 genes which have been associated with achromatopsia. Sequencing the coding regions of those genes from four affected and eight non-affected lambs showed that all affected lambs were homozygous for a mutation in the CNGA3 gene that changes amino acid R236 to a stop codon. By PCR RFLP-based testing, homozygosity for the stop codon mutation was detected in another 19 affected lambs. Non-affected individuals (n=386) were non-carriers or heterozygous for the mutation. While a selection program has been launched to eradicate the day blindness mutation from Improved Awassi flocks, a breeding nucleus of day-blind sheep has been established to serve as animal models for studying human achromatopsia. PMID- 19874886 TI - Whole-body or isolated ovary (60)Co irradiation: effects on in vivo and in vitro folliculogenesis and oocyte maturation. AB - For the first time, the effects of low doses of gamma-radiation were studied on folliculogenesis and on isolated oocytes. After irradiation of adult mice, even at the lowest dose, a drastic loss of primordial follicles was observed in serial sections of ovaries, with, in opposite, no effect on the other follicle stages. Moreover, oocytes freshly recovered from the largest antral follicles of irradiated adult ovaries exhibited significantly less regular Ca(2+) oscillations than controls. Finally, in vitro folliculogenesis demonstrated a smaller diameter of preantral follicles recovered from irradiated juvenile ovaries compared to control, and an increase in follicle atresia. Further on, PLC-beta1 localization was not affected in the enclosed oocytes whereas chromatin configuration revealed that a quarter of them had prematurely resumed meiosis or was fragmented. These results raise the question of the risk of genetic and teratogenic effects on women submitted to chronic exposure even of very low radiation. PMID- 19874887 TI - A role for Bach1 and HO-2 in suppression of basal and UVA-induced HO-1 expression in human keratinocytes. AB - Ultraviolet A (UVA) radiation is an oxidizing agent that strongly induces the heme oxygenase 1 (HO-1) gene and expression of the protein in cultured human skin fibroblasts but weakly induces it in skin keratinocytes. Lower basal levels of HO 1 and much higher basal levels of HO-2 protein are observed in keratinocytes compared with fibroblasts. Using both overexpression and knockdown approaches, we demonstrate that HO-2 modulates basal and UVA-induced HO-1 protein levels, whereas HO-1 levels do not affect HO-2 levels in skin fibroblasts and keratinocytes. Silencing of Bach1 strongly increases HO-1 levels in transformed HaCaT keratinocytes and these HO-1 levels are not further increased by either UVA irradiation or silencing of HO-2. This is consistent with the conclusion that high constitutive levels of HO-2 expression in keratinocytes are responsible for the resistance of these cells to HO-1 induction by UVA radiation and that Bach1 plays a predominant role in influencing the lack of HO-1 expression in keratinocytes. Bach1 inhibition leading to HO-1 induction reduced UVA-irradiation induced damage as monitored both by the extent of LDH release and by nuclear condensation, so that Bach1 inhibition seems to protect against UVA-irradiation induced damage in keratinocytes. PMID- 19874888 TI - Transdominant regulation of integrin function: mechanisms of crosstalk. AB - Transdominant inhibition of integrins or integrin-integrin crosstalk is an important regulator of integrin ligand binding and subsequent signaling events that control a variety of cell functions in many tissues. Here we discuss examples of integrin crosstalk and detail our current understanding of the molecular mechanisms that are involved in this receptor phenomenon. The cytoskeleton associated protein talin is a key regulator of integrin crosstalk. We describe how the interaction of talin and the cytoplasmic tail of beta integrin is controlled and how competitive inhibitors of this binding play a role in integrin crosstalk. We conclude with a discussion of how integrin crosstalk impacts the interpretation of integrin inhibitor and knockdown studies in both the laboratory and clinical setting. PMID- 19874889 TI - USP11 negatively regulates TNFalpha-induced NF-kappaB activation by targeting on IkappaBalpha. AB - IkappaBalpha serves as a central anchoring molecule in the sequestration of NF kappaB transcription factor in the cytoplasm. Ubiquitination-mediated IkappaBalpha degradation immediately precedes and is required for NF-kappaB nuclear translocation and activation. However, the precise mechanism for the deubiquitination of IkappaBalpha is still not fully understood. Using a proteomic approach, we have identified Ubiquitin Specific Peptidase 11 (USP11) as an IkappaBalpha associated deubiquitinase. Overexpression of USP11 inhibits IkappaBalpha ubiquitination. Recombinant USP11 catalyzes deubiquitination of IkappaBalpha in vitro. Moreover, knockdown of USP11 expression enhances TNFalpha induced IkappaBalpha ubiquitination and NF-kappaB activation. These data demonstrate that USP11 plays an important role in the downregulation of TNFalpha mediated NF-kappaB activation through modulating IkappaBalpha stability. In addition, overexpression of a catalytically inactive USP11 mutant partially inhibits TNFalpha- and IKKbeta-induced NF-kappaB activation, suggesting that USP11 also exerts a non-catalytic function in its negative regulation of TNFalpha mediated NF-kappaB activation. Thus, IkappaBalpha ubiquitination and deubiquitination processes function as a Yin-Yang regulatory mechanism on TNFalpha-induced NF-kappaB activation. PMID- 19874890 TI - Effect of hydroxyl substitution of flavone on angiogenesis and free radical scavenging activities: a structure-activity relationship studies using computational tools. AB - Angiogenesis is a key process needed for the growth and survival of solid tumors. Anti-angiogenesis may arrest the tumor growth and keep check on cancer metastasis. Developing antiangiogenic agents have remained a significant hope in the mainstream of anticancer research. The free radical implications in the initiation of cancers are well established. In the present studies, simple flavone and flavones with hydroxyl substitution in 'A' and 'C' ring at 3, 5, 6, and 7 were studied for antiangiogenic activities using chorioallantoic membrane (CAM) model and kinetics of DPPH (2,2-diphenyl-1-picryl hydrazine) and superoxide anion radical (SOR) scavenging activities. The docking of selected flavones with specific angiogenic targets such as vascular endothelial growth factor (VEGF), hypoxia inducible factor (HIF-1alpha) and vascular endothelial growth factor receptor-2 (VEGFR2) from human origin was carried out to focus the possible underlying mechanism of anti-angiogenesis. The result of the present studies shows that the 3-hydroxy substitution of the flavone was found to be the most promising lead for antiangiogenic activity in CAM model. The same was true for DPPH reduction with greater velocity as compared to other hydroxyl substitutions. However the 7- and 6-hydroxy substitution were observed to be more favourable for SOR scavenging activities as compared to other hydroxyl substitutions. The docking experiments shows that the VEGFR2 seems to be a structurally compatible target for tight binding of the flavones especially with 3-hydroxy substitution ( 9.78 kcal/mole) as compared to VEGF (-8.47 kcal/mole) and HIF-1alpha (-8.99 kcal/mole). The quantum chemical descriptors of the test flavones related to free radical scavenging and other biological activities were calculated using computational tools. The data is discussed in the light of structure-activity relationship. PMID- 19874891 TI - A new approach to characterise pharmaceutical aerosols: measurement of aerosol from a single dose aqueous inhaler with an optical particle counter. AB - An in-line sampling system with dilution units for aqueous droplet aerosols from single dose inhalers (Berodual Respimat, Boehringer Ingelheim Pharma GmbH & Co. KG, Germany) for an optical particle counter is described. The device has been designed to interface with a white light aerosol spectrometer (welas digital 2100, Palas GmbH, Germany) that allows the time-resolved measurement of highly concentrated aerosols. Performance of the sampling system with regard to the measured particle size distribution (PSD) is compared to Next Generation Impactor (NGI) and to laser diffraction measurements (Sympatec Inhaler and open bench). Optimal settings of the sampling system lead to PSDs that correspond well to those measured by the evaporation minimising NGI approach (15 L/min, cooled) and laser diffraction. The better accuracy of the new dilution unit in presence of an additional aerosol sampling filter in comparison to a previously described aerosol sampling system is shown for different settings of the sampling system. This allows a more precise quantification of the delivered drug amount which is also well correlated to the aerosol volume measured by the welas system. In addition, using time-resolved welas measurements provides insight into droplet size, evaporation and size changes of aerosol clouds delivered by liquid inhalers. PMID- 19874892 TI - Multiple duplications of the rare ace-1 mutation F290V in Culex pipiens natural populations. AB - Two amino acid substitutions in acetylcholinesterase 1 (AChE1), G119S and F290V, are responsible for resistance to organophosphate and carbamate insecticides in Culex pipiens mosquitoes. These mutations generate very different levels of insensitivity to insecticide inhibitors. We described here a biochemical method that rapidly identifies AChE1 variants (susceptible, G119S and F290V, named S, R and V, respectively) present in individual mosquitoes. We investigated the frequency of AChE1 phenotypes in 41 field samples collected around the Mediterranean Sea. F290V substitution was found only in 15 samples and at low frequency, whereas G119S was highly spread in all samples. However, seven V distinct alleles were identified whereas only one R allele was present. The [V] enzymatic phenotype was never observed alone, and the V allele was always found associated with the susceptible and/or G119S AChE1 ([VS], [VR] or [VRS] phenotypes). Furthermore, we showed the presence of duplicated alleles, associating a susceptible and a V copy of the ace-1 gene, in most individuals analyzed for its presence. Evolutionary forces driving the large number of F290V ace-1 alleles and their low frequency in Mediterranean countries are discussed. PMID- 19874893 TI - A systematic study of brainstem motor nuclei in a mouse model of ALS, the effects of lithium. AB - Transgenic mice expressing the human superoxide dismutase 1 (SOD-1) mutant at position 93 (G93A) develop a phenotype resembling amyotrophic lateral sclerosis (ALS). In fact, G93A mice develop progressive motor deficits which finally lead to motor palsy and death. This is due to the progressive degeneration of motor neurons in the ventral horn of the spinal cord. Although a similar loss is reported for specific cranial motor nuclei, only a few studies so far investigated degeneration in a few brainstem nuclei. We recently reported that chronic lithium administration delays onset and duration of the disease, while reducing degeneration of spinal motor neuron. In the present study, we extended this investigation to all somatic motor nuclei of the brain stem in the G93A mice and we evaluated whether analogous protective effects induced by lithium in the spinal cord were present at the brain stem level. We found that all motor but the oculomotor nuclei were markedly degenerated in G93A mice, and chronic treatment with lithium significantly attenuated neurodegeneration in the trigeminal, facial, ambiguus, and hypoglossal nuclei. Moreover, in the hypoglossal nucleus, we found that recurrent collaterals were markedly lost in G93A mice while they were rescued by chronic lithium administration. PMID- 19874894 TI - To the genesis of Burkitt lymphoma: regulation of apoptosis by EBNA-1 and SAP may determine the fate of Ig-myc translocation carrying B lymphocytes. AB - Chromosomal translocations that juxtapose one of the three immunoglobulin loci to the c-myc protooncogene are the hallmark of Burkitt lymphomas (BLs), whether they carry the Epstein Barr Virus (EBV) or not. Ig/myc translocations occur as accidents of normal B lymphocyte differentiation. Unless protected, the translocation carrying cells are apoptosis prone. However, the high B cell stimulatory cytokine level found in the two BL prone conditions, in chronic hyperendemic malaria and HIV infection, may rescue them. X-linked lymphoproliferative disease (XLP) is due to the lack of functional SAP protein, a consequence of mutation or deletion of the SAP gene. We and others have shown that SAP is pro-apoptotic. Here we summarize our finding that 8 of 10 EBV carrying, but none of 9 EBV negative BL lines express SAP. We suggest that the apoptosis prone Ig/myc translocation carrying EBV negative precursors of BL can only grow into lymphomas if they do not express SAP. However, their EBV positive counterparts are permissive for SAP expression, due to the anti-apoptotic function of EBNA-1. PMID- 19874895 TI - The quantitative research of composite immune indicator for crustacean. AB - Through analyzing the immunity indicators in recent crustacean research, two defects are pointed in comprehensive immunity evaluation, 1) the integrant indicators cannot comprehensively reflect the change of immunity, and 2) the conclusions that obtained from different indicators of immunity level cannot be compared objectively and scientifically. Basing on that, the paper firstly indicated that the immunity system could be regarded as a composite indicator. Secondly, the paper gave the specific definition of the composite immunity indicator (CII), and discussed the methods of calculation, especially provided two calculation methods of the weights, that is, the Analytic Hierarchy Process (AHP) and the Principal Component Analysis (PCA). Finally, examples were given to clarify the specific steps to compute the composite immunity indicator. The computing results gave the quantitative evaluation, which were in concordance with the existing conclusions. PMID- 19874896 TI - Phagocytosis by B-cells and neutrophils in Atlantic salmon (Salmo salar L.) and Atlantic cod (Gadus morhua L.). AB - Phagocytosis by fish cells has mostly been studied using adherent leucocytes, excluding suspended cells such as the majority of B-cells and neutrophils, but a recent study describes professional phagocytosis of latex beads and bacteria by B cells from rainbow trout. In the present study, phagocytosis by B-cells and neutrophils from salmon and cod was studied. Leucocytes were isolated from peripheral blood (PBL) and head kidney (HKL). By flow cytometry analyses, proportions of MAb labelled cell populations with internalized fluorescent beads, as well as the number of beads within each cell, could be determined. Phagocytic capacity and ability were demonstrated in B-cells and neutrophils from salmon and cod. In salmon, B-cells had higher phagocytic ability than neutrophils in HKL, but not in PBL. For cod the phagocytic ability of B-cells were lower than for neutrophils in both HKL and PBL, but the phagocytic capacity of cod B-cells were higher than for neutrophils in both HKL and PBL. For salmon B-cells the phagocytic capacity was lower than or similar to neutrophils in HKL and PBL. The total phagocytic ability of leucocytes was different in the species studied. The highest phagocytic ability was observed in cod, showing similar values for PBL and HKL. Salmon PBL displayed about twice the phagocytic ability of cod PBL. There seemed to be some major differences between the two fish species concerning phagocytosis. In salmon, a rather large proportion of phagocytic leucocytes were phagocytic B-cells, indicating that B-cells may have an important function in particle clearance in this species. In cod, phagocytic leucocytes in HKL and PBL were mostly neutrophils, and only a small proportion of B-cells were phagocytic, supporting the more prominent role of innate immune functions in cod neutrophils. PMID- 19874897 TI - Shared neural resources between left and right interlimb coordination skills: the neural substrate of abstract motor representations. AB - Functional magnetic resonance imaging was used to reveal the shared neural resources between movements performed with effectors of the left versus right body side. Prior to scanning, subjects extensively practiced a complex coordination pattern involving cyclical motions of the ipsilateral hand and foot according to a 90 degrees out-of-phase coordination mode. Brain activity associated with this (nonpreferred) coordination pattern was contrasted with pre existing isodirectional (preferred) coordination to extract the learning-related brain networks. To identify the principal candidates for effector-independent movement encoding, the conjunction of training-related activity for left and right limb coordination was determined. A dominantly left-lateralized parietal-to (pre)motor activation network was identified, with activation in inferior and superior parietal cortex extending into intraparietal sulcus and activation in the premotor areas, including inferior frontal gyrus (pars opercularis). Similar areas were previously identified during observation of complex coordination skills by expert performers. These parietal-premotor areas are principal candidates for abstract (effector-independent) movement encoding, promoting motor equivalence, and they form the highest level in the action representation hierarchy. PMID- 19874898 TI - Cortical gamma-oscillations modulated by listening and overt repetition of phonemes. AB - Both superior temporal gyrus and inferior Rolandic area have been reported to be involved in perception and production of speech in humans. Here, we determined how these cortical structures were activated by listening and subsequent overt articulation of syllables, by measuring event-related gamma-oscillations as quantitative measures of cortical activation. Fifteen subjects were presented an auditory syllable consisting of either "fee [fi:]," "faa [falpha:]," "hee [hi:]," or "haa [halpha:]," and were instructed to overtly repeat each given syllable. Gamma-oscillations in the superior temporal gyrus were highly augmented during syllable-presentation, least augmented at the onset of syllable-articulation, and again highly augmented following syllable-articulation. Gamma-oscillations were augmented in the inferior Rolandic area prior to and during syllable-articulation with the onset and peak occurring earlier in the left side. Subsets of the inferior Rolandic sites, more frequently on the left side, showed differential gamma-augmentation elicited by articulation of phoneme [f] more than [h] or phoneme [i:] more than [alpha:]. Our observations suggest that the superior temporal gyrus may be active when externally presented or articulated auditory stimuli are present, and may be minimally active when articulation is about to be initiated. Our novel observation of phoneme-specific differential gamma augmentation in the inferior Rolandic area may be partially attributed to the mouth position during phoneme-articulation. Our observations support the hypothesis that positioning of the mouth to articulate phonemes is predominantly driven and/or monitored by the primary sensorimotor area on the left side. PMID- 19874899 TI - Temporal lobe white matter asymmetry and language laterality in epilepsy patients. AB - Recent studies using diffusion tensor imaging (DTI) have advanced our knowledge of the organization of white matter subserving language function. It remains unclear, however, how DTI may be used to predict accurately a key feature of language organization: its asymmetric representation in one cerebral hemisphere. In this study of epilepsy patients with unambiguous lateralization on Wada testing (19 left and 4 right lateralized subjects; no bilateral subjects), the predictive value of DTI for classifying the dominant hemisphere for language was assessed relative to the existing standard-the intra-carotid Amytal (Wada) procedure. Our specific hypothesis is that language laterality in both unilateral left- and right-hemisphere language dominant subjects may be predicted by hemispheric asymmetry in the relative density of three white matter pathways terminating in the temporal lobe implicated in different aspects of language function: the arcuate (AF), uncinate (UF), and inferior longitudinal fasciculi (ILF). Laterality indices computed from asymmetry of high anisotropy AF pathways, but not the other pathways, classified the majority (19 of 23) of patients using the Wada results as the standard. A logistic regression model incorporating information from DTI of the AF, fMRI activity in Broca's area, and handedness was able to classify 22 of 23 (95.6%) patients correctly according to their Wada score. We conclude that evaluation of highly anisotropic components of the AF alone has significant predictive power for determining language laterality, and that this markedly asymmetric distribution in the dominant hemisphere may reflect enhanced connectivity between frontal and temporal sites to support fluent language processes. Given the small sample reported in this preliminary study, future research should assess this method on a larger group of patients, including subjects with bi-hemispheric dominance. PMID- 19874900 TI - Single shot partial dual echo (SPADE) EPI--an efficient acquisition scheme for reducing susceptibility artefacts in fMRI. AB - SPADE is a new acquisition scheme for fMRI based on dual echo EPI. As in previous work, additional spin echo EPI images are used to recover signal in regions that are affected by susceptibility related sensitivity loss in gradient echo EPI. However, with SPADE the additional spin echo images are only acquired for the affected slices, which reduces the acquisition time and enhances the time normalised signal-to-noise ratio. We demonstrate the feasibility of this approach and discuss potential applications of the SPADE technique in fMRI. We conclude that SPADE provides an efficient acquisition scheme for fMRI applications where whole brain coverage and sensitivity is required. PMID- 19874901 TI - Saccadic spike potentials in gamma-band EEG: characterization, detection and suppression. AB - Analysis of high-frequency (gamma-band) neural activity by means of non-invasive EEG is gaining increasing interest. However, we have recently shown that a saccade-related spike potential (SP) seriously confounds the analysis of EEG induced gamma-band responses (iGBR), as the SP eludes traditional EEG artifact rejection methods. Here we provide a comprehensive profile of the SP and evaluate methods for its detection and suppression, aiming to unveil true cerebral gamma band activity. The SP appears consistently as a sharp biphasic deflection of about 22 ms starting at the saccade onset, with a frequency band of approximately 20-90 Hz. On the average, larger saccades elicit higher SP amplitudes. The SP amplitude gradually changes from the extra-ocular channels towards posterior sites with the steepest gradients around the eyes, indicating its ocular source. Although the amplitude and the sign of the SP depend on the choice of reference channel, the potential gradients remain the same and non-zero for all references. The scalp topography is modulated almost exclusively by the direction of saccades, with steeper gradients ipsilateral to the saccade target. We discuss how the above characteristics impede attempts to remove these SPs from the EEG by common temporal filtering, choice of different references, or rejection of contaminated trials. We examine the extent to which SPs can be reliably detected without an eye tracker, assess the degree to which scalp current density derivation attenuates the effect of the SP, and propose a tailored ICA procedure for minimizing the effect of the SP. PMID- 19874902 TI - Atrophy patterns in Alzheimer's disease and semantic dementia: a comparison of FreeSurfer and manual volumetric measurements. AB - Alzheimer's disease (AD) and semantic dementia (SD) are characterized by different patterns of global and temporal lobe atrophy which can be studied using magnetic resonance imaging (MRI). Manual delineation of regions of interest is time-consuming. FreeSurfer is a freely available automated technique which has a facility to label cortical and subcortical brain regions automatically. As with all automated techniques comparison with existing methods is important. Eight temporal lobe structures in each hemisphere were delineated using FreeSurfer and compared with manual segmentations in 10 control, 10 AD, and 10 SD subjects. The reproducibility errors for the manual segmentations ranged from 3% to 6%. Differences in protocols between the two methods led to differences in absolute volumes with the greatest differences between methods found bilaterally in the hippocampus, entorhinal cortex and fusiform gyrus (p<0.005). However, good correlations between the methods were found for most regions, with the highest correlations shown for the ventricles, whole brain and left medial-inferior temporal gyrus (r>0.9), followed by the bilateral amygdala and hippocampus, left superior temporal gyrus, right medial-inferior temporal gyrus and left temporal lobe (r>0.8). Overlap ratios differed between methods bilaterally in the amygdala, superior temporal gyrus, temporal lobe, left fusiform gyrus and right parahippocampal gyrus (p<0.01). Despite differences in protocol and volumes, both methods showed similar atrophy patterns in the patient groups compared with controls, and similar right-left differences, suggesting that both methods accurately distinguish between the three groups. PMID- 19874903 TI - Modulation of neuronal activity after spinal cord stimulation for neuropathic pain; H(2)15O PET study. AB - Spinal cord stimulation (SCS) is an effective therapy for chronic neuropathic pain. However, the detailed mechanisms underlying its effects are not well understood. Positron emission tomography (PET) with H(2)(15)O was applied to clarify these mechanisms. Nine patients with intractable neuropathic pain in the lower limbs were included in the study. All patients underwent SCS therapy for intractable pain, which was due to failed back surgery syndrome in three patients, complex regional pain syndrome in two, cerebral hemorrhage in two, spinal infarction in one, and spinal cord injury in one. Regional cerebral blood flow (rCBF) was measured by H(2)(15)O PET before and after SCS. The images were analyzed with statistical parametric mapping software (SPM2). SCS reduced pain; visual analog scale values for pain decreased from 76.1+/-25.2 before SCS to 40.6+/-4.5 after SCS (mean+/-SE). Significant rCBF increases were identified after SCS in the thalamus contralateral to the painful limb and in the bilateral parietal association area. The anterior cingulate cortex (ACC) and prefrontal areas were also activated after SCS. These results suggest that SCS modulates supraspinal neuronal activities. The contralateral thalamus and parietal association area would regulate the pain threshold. The ACC and prefrontal areas would control the emotional aspects of intractable pain, resulting in the reduction of neuropathic pain after SCS. PMID- 19874904 TI - Phylogenetic relationships of the western North American cyprinid genus Richardsonius, with an overview of phylogeographic structure. AB - Diversification of many North American taxa, including freshwater fishes, has been heavily influenced by the effects of complex geological and climatic events throughout the Cenozoic that have significantly altered the landscape. Here, we employ an array of phylogenetic analyses using a multiple gene tree approach to address several questions regarding the phylogenetic relationships of the North American cyprinid genus Richardsonius and two other closely related genera, Clinostomus and Iotichthys. We also use divergence time estimates generated using fossil calibrations to qualitatively assess the phylogeographic implications of evolution within the group. Mitochondrial and nuclear DNA sequences show a sister relationship between Iotichthys and Richardsonius, with Clinostomus being sister to an Iotichthys-Richardsonius clade, hence the currently recognized sister relationship between Clinostomus and Richardsonius is not supported. These genera appear to be monophyletic lineages, and sister species within genera appear to be reciprocally monophyletic. The two species within the genus Richardsonius both exhibit phylogeographic structure that is worthy of further investigation. Divergence time estimates between genera and species are Miocene or Pliocene in age, and divergence between phylogroups within species occurred in the late Pliocene to Pleistocene. These splits coincide with documented geological and climatic events. PMID- 19874905 TI - Suitability of chloroplast LSU rDNA and its diverse group I introns for species recognition and phylogenetic analyses of lichen-forming Trebouxia algae. AB - To date, species identification of lichen photobionts has been performed principally on the basis of microscopic examinations and molecular data from nuclear-encoded genes. In plants, the chloroplast genome has been more readily exploited than the nuclear genome for systematic investigations. At the present time, very little information is available about the chloroplast genome of lichen forming algae. For this reason, we have sequenced a portion of the gene encoding for the chloroplast large sub-unit rRNA (LSU rDNA) as a new molecular marker. Sequencing of the chloroplast LSU rDNAs revealed the existence of an unusual diversity of group I introns (a total of 31) within 15 analyzed Trebouxia species. The number, sequence and insertion site of these introns were very different among species, contributing to their recognition. A relatively large intron-free portion of the chloroplast LSU rDNA and part of the nuclear ribosomal cistron (18S-5.8S-26S) between the nuclear internal transcribed spacers (nrITS) were subjected to phylogenetic analyses. The obtained results indicate that data combination from both nuclear and chloroplast sequences can improve phylogenetic accuracy. Herein, we propose the suitability of both intronic and exonic sequences of the chloroplast LSU rDNA for species recognition, and an exonic sequence spanning from position 879 to 1837 in the Escherichia coli 23S rDNA for phylogenetic analyses of Trebouxia phycobionts. PMID- 19874906 TI - Systematics and biogeography of the Neotropical genus Mabuya, with special emphasis on the Amazonian skink Mabuya nigropunctata (Reptilia, Scincidae). AB - Phylogenetic analyses using up to 1532 base pairs (bp) of mitochondrial DNA from 106 specimens of Neotropical Mabuya, including 18 of the 19 recognized South American and Mesoamerican species, indicate that most species of the genus are monophyletic, including M. nigropunctata that had previously been reported to be paraphyletic. The present results shows that this species includes three highly divergent and largely allopatric lineages restricted to occidental, meridional, and oriental Amazonia. Our dataset demonstrates that previous claims regarding the paraphyletic status of M. nigropunctata and the phylogenetic relationships within this species complex based on the analysis of three mitochondrial and four nuclear genes (approx. 5000bp) were erroneous and resulted from two contaminated cytochrome b sequences. The phylogenetic results indicate that diversification in the Neotropical genus Mabuya started approximately in the Middle Miocene (15.5 13.4Ma). The divergence dates estimated for the Mabuya nigropunctata species complex suggest that the major cladogenetic events that produced the three main groups (occidental (oriental+meridional)) occurred during the Late Miocene. These estimations show that diversification within the M. nigropunctata species complex was not triggered by the climatic changes that occurred during the Pleistocene, as has been suggested by several authors. Rather, our data support the hypothesis that the late tertiary (essentially Miocene epoch) was a period that played a very important role in the generation of biological diversity in the Amazonian forests. Speciation between Mabuyacarvalhoi, endemic to the coastal mountain range of Venezuela, and M. croizati, restricted to the Guiana Shield, occurred during the Middle Miocene and may have been as the result of a vicariant event produced by the formation of the present day Orinoco river drainage basin and the consequent appearance of the Llanos del Orinoco, which acted as a barrier to dispersal between these two species. The split between M. bistriata and M. altamazonica and between the occidental and (meridional+oriental) clades of M. nigropunctata fits very well with the biogeographic split between the eastern and western Amazon basins reported for several other taxa. PMID- 19874907 TI - REP provides meaningful measurement of support across datasets. AB - The relative optimality of the best and next-best hypotheses indicates the strength of support for the optimal hypothesis and may be calculated as either the difference or ratio of their optimality scores. The Goodman-Bremer support measure (GB) calculates the support for a given clade in the most parsimonious tree as the difference between the length of the optimal tree and the optimal tree that lacks that clade. The ratio of explanatory power (REP) support measure calculates support as the ratio of optimality scores, which simplifies to the ratio of observed GB and the maximum possible GB, GB/GB(max). In this paper we show that REP support provides a logical basis for comparison of support across datasets and that recent claims to the contrary are incorrect. PMID- 19874908 TI - Dietary nitrate--good or bad? AB - There has now been a great deal written about inorganic nitrate in both the popular press and in scientific journals. Papers in the 1970s warned us that inorganic nitrate could theoretically be metabolised in the human body to N nitroso compounds, many of which are undoubtedly carcinogenic. More recently there is evidence that nitrate can undergo metabolic conversion to nitrite and nitric oxide and perform a useful protective function to prevent infection, protect our stomach, improve exercise performance and prevent vascular disease. PMID- 19874909 TI - Molecular identification of the advanced third-stage larvae (ADV L(3)) of Gnathostoma lamothei in Tabasco, Mexico. AB - Advanced third-stage larvae (ADV L(3)) of Gnathostoma spp. were collected from the muscle tissue of three species of freshwater fish (i.e., Gobiomorus dormitor, Petenia splendida, and Parachromis managuensis) in Swamps of Centla, Tabasco, Mexico. Nine sequences of the ITS2 of the ribosomal DNA of Gnathostoma spp. were compared with sequences obtained from GenBank for G. binucleatum, G. lamothei, G. miyazakii, G. spinigerum, and G. turgidum. Sequences of the ADV L(3) from P. splendida (Isla Chinal), P. managuensis (Isla Chinal), and of two of the six larvae collected from G. dormitor (Tres Brazos), were identical to that of G. binucleatum (GenBank). Sequences from the other four larvae from G. dormitor (Tres Brazos) are identical to the sequence of G. lamothei (GenBank). This is the first record of the intermediate host of G. lamothei. The only species documented to cause human gnathostomiasis in the Americas is G. binucleatum. Our finding of G. binucleatum, and G. lamothei parasitizing the commercially important fish species, G. dormitor in Centla swamps, indicates the possibility of G. lamothei causing human gnathostomiasis in Mexico as well. PMID- 19874911 TI - Extremely miniaturised and highly complex: the thoracic morphology of the first instar larva of Mengenilla chobauti (Insecta, Strepsiptera). AB - Thoracic structures of the extremely small first instar larva of the strepsipteran species Mengenilla chobauti (ca. 200 microm) were examined, described and reconstructed 3-dimensionally. The focus is on the skeletomuscular system. The characters were compared to conditions found in other insect larvae of very small (Ptiliidae) or large (Dytiscus) size (both Coleoptera) and features of "triungulin" larvae, first instar larvae of Rhipiphoridae, Meloidae (both Coleoptera), and Mantispidae (Neuroptera). The specific lifestyle and the extreme degree of miniaturisation result in numerous thoracic modifications. Many sclerites of the exo- and endoskeleton are reduced. Cervical sclerites, pleural ridges, furcae and spinae are absent. Most of the longitudinal muscles are connected within the thorax, and a pair of ventral longitudinal muscles is present in the pleural region of the meso- and metathorax. This results in a high intersegmental flexibility. Due to the size reduction and the correlated shift of the brain to the thorax, with 94 identified muscles the thoracic musculature appears highly compact. Compared to larger larvae the number of both the individual muscles and the muscle bundles are distinctly reduced. The thorax of the first instar larvae displays many additional strepsipteran autapomorphies. At least partly due to the highly specialised condition, potential synapomorphies with other groups were not found. PMID- 19874910 TI - Evidence of hybridization between Taenia saginata and Taenia asiatica. AB - There has long been a debate as to the specific status of the cestode Taenia asiatica, with some people regarding it as a distinct species and some preferring to recognize it as a strain of Taenia saginata. The balance of current opinion seems to be that T. asiatica is a distinct species. In this study we performed an allelic analysis to explore the possibility of gene exchange between these closely related taxa. In total, 38 taeniid tapeworms were collected from humans living in many localities including Kanchanaburi Province, Thailand where the two species are sympatric. A mitochondrial DNA (mtDNA)-based multiplex PCR tentatively identified those parasites as T. asiatica (n=20) and T. saginata (n=18). Phylogenetic analyses of a mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and two nuclear loci, for elongation factor-1 alpha (ef1) and ezrin radixin-moesin (ERM)-like protein (elp), assigned all except two individual parasites to the species indicated by multiplex PCR. The two exceptional individuals, from Kanchanaburi Province, showed a discrepancy between the mtDNA and nuclear DNA phylogenies. In spite of their possession of sequences typical of the T. saginata cox1 gene, both were homozygous at the elp locus for one of the alleles found in T. asiatica. At the ef1 locus, one individual was homozygous for the allele found at high frequency in T. asiatica while the other was homozygous for the major allele in T. saginata. These findings are evidence of occasional hybridization between the two species, although the possibility of retention of ancestral polymorphism cannot be excluded. PMID- 19874912 TI - Endosulfan in vitro toxicity in Atlantic salmon hepatocytes obtained from fish fed either fish oil or vegetable oil. AB - The composition of the feed may alter the cellular composition of an organism and thus has the potential to influence a xenobiotic response. The main aim of this study was to see if the fatty acid composition of primary hepatocytes isolated from Atlantic salmon (Salmo salar L.) obtained from fish fed either a fish oil or a vegetable oil based diet, influenced the response to endosulfan exposure in vitro. The primary cultures were exposed to six different concentrations of endosulfan (0.001, 0.01, 0.1, 1, 10 and 100 microM) for 48 h. Cell morphology as well as a molecular toolbox of 16 genes encoding stress responsive and biotransformation proteins was examined. Endosulfan exposure caused moderate cytotoxicity and steatosis in a dose-dependent manner in the hepatocytes. In general, endosulfan hepatoxicity seems to be unaffected by the fatty acid composition of the hepatocytes. Exceptions were general stress (HSP70) and markers for estrogen exposure (ZP and VTG), which appeared to be slightly less responsive in hepatocytes isolated from the vegetable oil fed fish. PMID- 19874913 TI - Using hierarchical dynamic Bayesian networks to investigate dynamics of organ failure in patients in the Intensive Care Unit. AB - In intensive care medicine close monitoring of organ failure status is important for the prognosis of patients and for choices regarding ICU management. Major challenges in analyzing the multitude of data pertaining to the functioning of the organ systems over time are to extract meaningful clinical patterns and to provide predictions for the future course of diseases. With their explicit states and probabilistic state transitions, Markov models seem to fit this purpose well. In complex domains such as intensive care a choice is often made between a simple model that is estimated from the data, or a more complex model in which the parameters are provided by domain experts. Our primary aim is to combine these approaches and develop a set of complex Markov models based on clinical data. In this paper we describe the design choices underlying the models, which enable them to identify temporal patterns, predict outcomes, and test clinical hypotheses. Our models are characterized by the choice of the dynamic hierarchical Bayesian network structure and the use of logistic regression equations in estimating the transition probabilities. We demonstrate the induction, inference, evaluation, and use of these models in practice in a case study of patients with severe sepsis admitted to four Dutch ICUs. PMID- 19874914 TI - In vitro stimulation of Balb/c and C57 BL/6 splenocytes by a recombinantly produced banana lectin isoform results in both a proliferation of T cells and an increased secretion of interferon-gamma. AB - Lectins are widely used in many types of assay but some lectins such as banana lectin (BanLec) are recognised as potent immunostimulators. Although BanLec's structure and binding characteristics are now familiar, its immunostimulatory potential has not yet been fully explored. The synthesis by recombinant technology of a BanLec isoform (rBanLec) whose binding properties are similar to its natural counterpart has made it possible to overcome the twin problems of natural BanLec's microheterogeneity and low availability. This study's aim is to explore the immunostimulatory potential of rBanLec in the murine model. Analyses of the responses of Balb/c- and C57 BL/6-originated splenocytes to in vitro rBanLec stimulation were performed to examine the dependency of rBanLec's immunostimulatory potential upon the splenocytes' genetic background. It is shown that the responses of Balb/c- and C57 BL/6-originated splenocytes to rBanLec stimulation differ both qualitatively and in intensity. The hallmarks of the induced responses are T lymphocyte proliferation and intensive interferon-gamma secretion. Both phenomena are more marked in Balb/c-originated cultures; Balb/c originated lymphocytes produce interleukin (IL)-4 and IL-10 following rBanLec stimulation. Our results demonstrate that any responses to rBanLec stimulation are highly dependent upon genetic background; they suggest that genetic background must be an important consideration in any further investigations using animal models or when exploring rBanLec's potential human applications. PMID- 19874915 TI - Anti-asthmatic activity of phenolic compounds from the roots of Gastrodia elata Bl. AB - We previously reported that 4-hydroxy-3-methoxybenzaldehyde has the most potent anti-inflammatory and analgesic activity of eight phenolic compounds obtained from the dried roots of Gastrodiaelata (GE) Blume (Orchidaceae); its activity may be related to inhibition of cyclooxygenase activities and oxidation. In the present study, the effects of nine phenolic compounds from GE on immediate-phase (IAR) and late-phase (LAR) asthmatic responses after aerosolized-ovalbumin (OA) challenge were evaluated by determining the specific airway resistance (sRaw) using a double-chambered plethysmograph in conscious guinea pigs with IgE mediated asthma. Furthermore, recruitment of leukocytes, histamine release, and eosinophil peroxidase (EPO) and phospholipase A(2) (PLA(2)) activities were determined in bronchoalveolar lavage fluids (BALF) 24h after the antigen challenge. 4-Hydroxy-3-methoxybenzyl alcohol (12.5mg/kg) significantly (p<0.05) inhibited sRaw in IAR and in LAR by 51.97+/-4.96% and 39.93+/-3.46%, respectively, compared to that of the controls. Further, hydroxy-3-methoxybenzyl alcohol significantly (p<0.05) inhibited recruitment of leukocytes in accordance with amelioration of eosinophilia and neutrophilia, histamine (30.66+/-5.20%), EPO activity (21.58+/-2.02%), and specific PLA(2) activity (16.60+/-2.52%) in BALF compared with the control. In addition, bis-(4-hydroxyphenyl) methane, 4 hydroxy-3-methoxybenzoic acid, and 4-hydroxy-3-methoxybenzaldehyde (12.5mg/kg) significantly (p<0.05) inhibited sRaw, while bis-(4-hydroxyphenyl) methane, benzyl alcohol, and 4-hydroxybenzaldehyde at 12.5mg/kg significantly (p<0.05) inhibited leukocytes, histamine, EPO and PLA(2) activities in BALF compared with the controls. The phenolic glycoside, parishin had less activity compared to aglycones, 4-hydroxybenzyl compounds. These results suggest that the C(4) hydroxy and C(3) methoxy radicals in benzyl alcohols and aldehydes play important roles in mediating the anti-asthmatic activities of these compounds. PMID- 19874916 TI - Suppression of Toll-like receptor 2 or 4 agonist-induced cyclooxygenase-2 expression by 4-oxo-4-(2-oxo-oxazolidin-3-yl)-but-2-enoic acid ethyl ester. AB - Toll-like receptors (TLRs) recognize molecular structures derived from microbes including bacteria, viruses, yeast, and fungi, and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of nuclear factor-kappaB (NF-kappaB) transcription factor leading to the induction of inflammatory gene products including cytokines and cyclooxygenase-2 (COX-2). In the present report, we demonstrate biochemical evidence that the fumaryl oxazolidinone derivative 4-Oxo-4-(2-oxo-oxazolidin-3-yl)-but-2-enoic acid ethyl ester (OSL07), which was previously synthesized in our laboratory, inhibits the NF-kappaB activation induced by TLR agonists and overexpression of downstream signaling components of TLRs, MyD88 and IKKbeta. OSL07 also inhibits TLR agonist induced COX-2 expression. These results indicate that the anti-inflammatory effects of OSL07 are caused by the modulation of the immune responses regulated by TLR signaling pathways. PMID- 19874917 TI - A nontoxic derivative of lipopolysaccharide increases immune responses to Gardasil HPV vaccine in mice. AB - Human papillomavirus (HPV) is the causative agent of cervical cancer, the second most common cause of cancer death in women worldwide. The licensed HPV vaccine Gardasil((R)) from Merck & Co. is a quadrivalent vaccine containing virus-like particles (VLPs) of the L1 proteins from HPV types 6, 11, 16, and 18 adsorbed on aluminum salts (alum). CIA07 is an immunostimulatory agent comprised of bacterial DNA fragments (CIA02) and a nontoxic derivative of lipopolysaccharide (CIA05) that has been shown to have antitumor activity and adjuvant activity for viral and bacterial vaccine antigens. We investigated whether these CIAs are capable of promoting the immune response to Gardasil. Balb/c mice were immunized intramuscularly twice three weeks apart with 1/20 human dose of Gardasil alone or in combination with CIA02, CIA05 or both, and immune responses were assessed. The serum anti-HPV16 L1 VLP IgG antibody titer was significantly higher in mice administered CIA05 or CIA05 plus CIA02, but not in those given CIA02, compared with mice given Gardasil alone. A secreted alkaline phosphatase (SEAP)-based pseudovirus neutralization assay showed increased neutralizing antibody titers in both CIA05 and CIA05 plus CIA02 groups. Coadministration of CIA05 with Gardasil led to a marked increase in serum IgG2a antibody titer and the percentage of interferon (IFN)-gamma(+) cells in the spleen, indicating that CIA05 effectively promotes Th1-type immune responses. These data indicate that CIA05, in synergy with alum, enhances the immune response to HPV L1 VLPs and suggest its potential as an adjuvant for the development of a potent prophylactic HPV vaccine. PMID- 19874918 TI - Human intestinal microbiota and healthy ageing. AB - Earlier studies have indicated a decrease in anaerobes and bifidobacteria and a concomitant increase in enterobacteria in the intestinal microbiota with ageing. However, new data obtained with molecular techniques suggests decreased stability and increased diversity of the gut microbiota with advancing age. Further, no simple marker change in microbiota composition can be identified. Except for the reduced immune function, ageing itself may have relatively little effect on overall gastrointestinal function. Concomitant changes in nutrition, increased incidence of disease and corresponding use of medication with advancing age modify the composition of the microbial community of the gastrointestinal tract. This mini-review will focus on the recent findings on the gut microbiota of the elderly and on the potential benefits of probiotics, prebiotics and synbiotics. PMID- 19874919 TI - Water-insoluble silk films with silk I structure. AB - Water-insoluble regenerated silk materials are normally produced by increasing the beta-sheet content (silk II). In the present study water-insoluble silk films were prepared by controlling the very slow drying of Bombyx mori silk solutions, resulting in the formation of stable films with a predominant silk I instead of silk II structure. Wide angle X-ray scattering indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared by slow drying had a globule-like structure at the core surrounded by nano-filaments. The core region was composed of silk I and silk II, surrounded by hydrophilic nano-filaments containing random turns and alpha-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. Differential scanning calorimetry results revealed that silk I crystals had stable thermal properties up to 250 degrees C, without crystallization above the T(g), but degraded at lower temperatures than silk II structure. Compared with water- and methanol-annealed films the films prepared by slow drying had better mechanical ductility and were more rapidly enzymatically degraded, reflecting the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated by the present approach of very slow drying, mimicking the natural process. The results also point to a new mode of generating new types of silk biomaterials with enhanced mechanical properties and increased degradation rates, while maintaining water insolubility, along with a low beta-sheet content. PMID- 19874920 TI - Cyclodextrin-functionalized biomaterials loaded with miconazole prevent Candida albicans biofilm formation in vitro. AB - Polyethylene (PE) and polypropylene (PP) were functionalized at their surfaces with cyclodextrins (CDs) in order to prevent the adhesion and proliferation of Candida albicans on medical devices made from these polymers. The surface functionalization involved the grafting of glycidyl methacrylate (GMA) after oxidative gamma-ray pre-irradiation, followed by the attachment of beta-CD and HP beta-CD to PE-g-GMA and PP-g-GMA surfaces. The yield of CD functionalization directly depended on the amount of GMA grafted. The presence of CDs on the surface of the polymers did not compromise their cell compatibility, but remarkably changed their protein adsorption profile. In contrast to unmodified PE and PP that adsorb significant amounts of fibrinogen ( approximately 0.047 mg cm( 2)) but not albumin, the CD-modified polyethers promoted the adsorption of albumin (between 0.015 and 0.155 mg cm(-2)) and reduced the adsorption of fibrinogen. Furthermore, functionalization with CDs provided PE and PP with the capability to incorporate the anti-fungal drug miconazole (up to 0.27 mg cm(-2)), leading to reduced biofilm formation by C. albicans in an in vitro biofilm model system. Overall, the results of the work indicate that the novel approach for functionalization of PE and PP is potentially useful to reduce the likelihood of foreign body-related infections. PMID- 19874921 TI - A serologic test for irritable bowel syndrome: real meat or bare bones? PMID- 19874922 TI - Endoscopic ablation of dysplastic Barrett's esophagus: are we there yet? PMID- 19874923 TI - Comparison of pretreatment strategies for enzymatic saccharification and fermentation of barley straw to ethanol. AB - Barley straw used in this study contained 34.3% cellulose, 23.0% hemicellulose and 13.3% lignin (moisture, 6.5%). Several pretreatments (dilute acid, lime and alkaline peroxide) and enzymatic saccharification procedures were evaluated for the conversion of barley straw to monomeric sugars. The maximum release of sugars (glucose, 384 mg; xylose, 187 mg; arabinose, 32 mg; total sugars, 604 mg/g; 94% of maximum theoretical sugar yield) from barley straw (10%, w/v) was obtained by alkaline peroxide (2.5% H(2)O(2), pH 11.5) pretreatment (35 degrees C, 24 hours) and enzymatic saccharification (45 degrees C, pH 5.0, 120 hours) after diluting 2 times before adding a cocktail of three commercial enzyme preparations (cellulase, beta-glucosidase and hemicellulase) each at the dose level of 0.15 ml/g of straw. Dilute acid and lime pretreatments followed by enzymatic saccharification generated 566 mg (88% yield) and 582 mg (91% yield) total sugars/g of barley straw, respectively. The yield of ethanol from the dilute acid pretreated and enzymatically saccharified barley straw hydrolyzate (23.7g sugars/L) was 11.4g/L (0.48g/g available sugars, 0.26g/g straw) by the mixed sugar utilizing recombinant Escherichia coli strain FBR5 in 17 hours. The ethanol yields were 11.4 and 11.9g/L from 24.4 and 26.2g sugars/L obtained from lime and alkaline peroxide pretreated barley straw, respectively. No inhibition of fermentation occurred by any of the three pretreatments under the conditions used. PMID- 19874924 TI - Comparative varicella vaccine effectiveness during outbreaks in day-care centres. AB - BACKGROUND: Routine varicella vaccination for children >11 months was introduced in Germany in 2004 with three different vaccine brands available. In 2008 and 2009, we investigated seven varicella outbreaks in day-care centres (DCC). METHODS: Varicella disease and vaccination status of 1084 children was reviewed to evaluate vaccination coverage (VC), brand-specific varicella vaccine effectiveness (VE), and risk factors of breakthrough varicella (BV, >42 days after vaccination). A case was defined as a child with acute onset of varicella attending one of the respective DCC at the time of outbreak. Children with a previous history of varicella, age<11 months, vaccinated at age<11 months or <42 days before disease onset or during the outbreak were excluded from VE and BV risk factors analyses (adjusted for gender, age and DCC). FINDINGS: Of 631 children with available vaccination information, 392 (62%) were vaccinated at least once. Overall VE among 352 children eligible was 71% (95% confidence interval (CI) 57-81, p<0.001) and differed significantly by disease severity and number of doses administered. Risk for BV was higher for 1 dose of Varilrix (RR=2.8, 95%CI 1.0-7.8, p=0.05) or Priorix-Tetra (RR=2.4, 95%CI 0.7-8.3, p=0.18) but lower for 2 doses of Priorix-Tetra (RR=0.5, 95%CI 0.1-2.7, p=0.41) than for 1 dose of Varivax. INTERPRETATION: Enhanced efforts to increase VC in Germany and 2 doses varicella vaccine might be successful to reduce the risk for BV. The evidence that VE and risk of BV are associated with vaccine brand needs further investigation. PMID- 19874926 TI - Anti-preS responses influence the anti-HBs response in newborns after vaccination with the third generation Sci-B-Vac vaccine. AB - We analysed the specificity and significance of the antibody response towards the linear preS1 sequence that has been shown to represent the "hepatocyte binding site" comprising amino acids preS1 (21-47) or the specific preS2 (131-140) antibody response to the "polymerised albumin receptor" in relation to the antibody response to hepatitis B surface antigen during immunisation of healthy children with the preS-containing Sci-B-Vac vaccine. Twenty-eight healthy newborns received three doses of the Sci-B-Vac vaccine according to a 0-, 1-, and 6-month scheme. Seventeen (61%) of the 28 newborns had detectable levels of anti preS1 (21-47) antibodies and 14 (50%) were anti-preS2 (131-140) reactive at 6 and/or 9 months after initiation of the vaccination. The mean levels of anti-HBs were significantly higher in the anti-preS2 (131-140) non-reactive (24580+/ 7815IU/l, mean+SEM) compared with the reactive sera (7287+/-2317IU/l, p<0.025). The highest anti-HBs levels were found in newborns who exhibited reactivity towards the aa 21-47 of the preS1 but lacked anti-preS2 (131-140) reactivity. PMID- 19874925 TI - A randomized and controlled Phase 1 study of the safety and immunogenicity of the AMA1-C1/Alhydrogel + CPG 7909 vaccine for Plasmodium falciparum malaria in semi immune Malian adults. AB - A double blind, randomized and controlled Phase 1 clinical trial was conducted to assess the safety and immunogenicity in malaria-exposed adults of the Plasmodium falciparum blood stage vaccine candidate Apical Membrane Antigen 1-Combination 1 (AMA1-C1)/Alhydrogel with and without the novel adjuvant CPG 7909. Participants were healthy adults 18-45 years old living in the village of Doneguebougou, Mali. A total of 24 participants received 2 doses one month apart of either 80 microg AMA1-C1/Alhydrogel or 80 microg AMA1-C1/Alhydrogel + 564 microg CPG 7909. The study started in October 2007 and completed follow up in May 2008. Both vaccines were well tolerated, with only mild local adverse events and no systemic adverse events judged related to vaccination. The difference in antibody responses were over 2-fold higher in the group receiving CPG 7909 for all time points after second vaccination and the differences are statistically significant (all p<0.05). This is the first use of the novel adjuvant CPG 7909 in a malaria exposed population. PMID- 19874927 TI - Identification of mutations in a candidate dengue 4 vaccine strain 341750 PDK20 and construction of a full-length cDNA clone of the PDK20 vaccine candidate. AB - Dengue 4 virus strain 341750 serially passaged 20 times in primary dog kidney (PDK) cells was shown to have reduced infectivity for rhesus monkeys but was immunogenic and protected the monkeys from challenge with low passage parent dengue 4 virus. The dengue 4 PDK20 virus was also shown to be attenuated for human volunteers. We compared the genomic nucleotide sequences of low passage parent and PDK20 attenuated vaccine strains and identified 11 nucleotide (nt) substitutions in the PDK20 genome. Five mutations caused amino acid changes in viral proteins E (N366N/S), NS1 (E146Q), NS4B (S/L112L and A240V), and NS5 (F/L790L). Silent mutations occurred in genes encoding NS1 (nt 2609), NS3 (nt 6113, 6230 and 6239) and NS5 (nt 8081 and 8588). A full-length cDNA clone of the dengue 4 strain 341750 PDK20 was constructed and RNA transcripts of the clone were infectious in monkey kidney (LLC-MK(2)) and Aedes albopictus (C6/36) cells. The sequence analysis and availability of an infectious clone provide molecular tools to investigate the basis for the attenuation of dengue 4 virus. PMID- 19874929 TI - A celebration and remembrance. PMID- 19874930 TI - Design and statistical methodology of the National Surgical Quality Improvement Program: why is it what it is? AB - This article reviews the philosophy and principles of the National Surgical Quality Improvement Program (NSQIP) that the founders of the program had in mind when they developed the program; explains how the philosophy and principles led to the design and statistical methods that were chosen for the program; and reviews recently proposed changes to the program and potential problems that these changes may create. PMID- 19874928 TI - Hyaluronan oligosaccharide treatment of chondrocytes stimulates expression of both HAS-2 and MMP-3, but by different signaling pathways. AB - OBJECTIVE: Small hyaluronan (HA) oligosaccharides displace HA from the cell surface and induce cell signaling events. In articular chondrocytes this cell signaling is mediated by the HA receptor CD44 and includes stimulation of genes involved in matrix degradation such as matrix metalloproteinases (MMPs) as well as matrix repair genes including collagen type II, aggrecan and HA synthase-2 (HAS-2). The objective of this study was to determine whether stimulation of HAS 2 and MMP-3 by HA oligosaccharides is due to the activation of a single, cascading pathway or multiple signaling pathways. METHOD: Bovine articular chondrocytes were pre-treated with a variety of inhibitors of major signaling pathways prior to the addition of HA oligosaccharides. Changes in HA were monitored by real time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of HAS-2 mRNA, HA ELISA and HA accumulation at the cell surface. A 1900 base pair sequence containing the proximal promoter of HAS-2 was inserted into a luciferase reporter construct, transfected into human immortalized chondrocytes and assayed in a similar fashion. RESULTS: While our previous studies demonstrated that HA oligosaccharides stimulate MMP-13 activity via activation of p38 MAP kinase and NF-kappaB, inhibitors of these pathways did not affect the stimulation of HAS-2 mRNA expression. However, inhibiting the phosphatidylinositol-3-kinase pathway blocked HA oligosaccharide-mediated stimulation of HAS-2 yet had no effect on MMP-3. Wortmannin and LY294002 also blocked HA oligosaccharide-induced serine and threonine Akt phosphorylation. Treatment of transfected immortalized chondrocytes with HA oligosaccharides resulted in stimulation of HAS-2 mRNA, activation of Akt and enhanced luciferase activity-activity that was blocked by inhibitors of Akt phosphorylation. CONCLUSIONS: Changes in chondrocyte-matrix interactions by HA oligosaccharides induce altered matrix metabolism by the activation of least two distinct signaling pathways. PMID- 19874931 TI - Adjusted or unadjusted outcomes. AB - BACKGROUND: Surgeons have long maintained an interest in assessing the outcomes of their therapeutic efforts. Previously, such goals were supported by mortality and morbidity conferences or surgical audits. The latter typically focus on unadjusted rates of adverse events. While comparisons of these outcome metrics between individuals or institutions are held to portray quality of surgical care, such comparisons are compromised by the divergent risk profiles associated with the patient population in question, underscoring the import of adequate and validated risk adjustment measures. Numerous risk adjustment strategies have been developed, based either on more readily available, and thus less expensive, administrative claims data or on more reliable and robust, but more expensive, clinical data. The National Surgical Quality Improvement Program (NSQIP), which is requires abstraction of clinical data, stands as the "gold standard" for assessment of surgical quality. DATA SOURCES: While risk adjustment seems essential to truly assess surgical quality, alternatives to use of clinical data continue to be explored. Some alternatives from previous works published by the author and others are briefly reviewed in this presentation. CONCLUSIONS: When assessing the quality of surgical outcomes, risk adjustment seems superior. Ongoing research is needed to help achieve balance between the benefit of clinically based models and less expensive alternatives based on administrative data. PMID- 19874932 TI - Evaluation of healthcare quality: a tale of three giants. AB - Although the concept of quality of care goes as far back as King Hammurabi in 1700 bc, and many have worked on improving the quality of care in medicine since, 3 individuals receive credit for laying down the foundation for the evaluation and measurement of quality of care in modern surgery: Ernest Amory Codman, Avedis Donabedian, and Shukri Khuri. Donabedian was not a surgeon, but his concepts in systems of care provided the basis for the modern engineering design of surgical care delivery. Without crossing paths, each of those giants built on the contributions of their predecessors. They shared the traits of tremendous determination in the face of many challenges and adversities and a sense of enthusiasm in a belief that resulted in improved and safer care. PMID- 19874933 TI - How do (and why should) I use the National Surgical Quality Improvement Program? AB - BACKGROUND: The National Surgical Quality Improvement Program (NSQIP) is celebrating its 15th year in the Veterans Affairs. The full implementation of this program in the VA was associated with a 27% reduction in mortality and a 45% reduction in morbidity in the VA over this timeframe. The objective of this article is to understand the internal and external motivations for using the NSQIP and how NSQIP data can be used to improve outcomes. We also outline several methods to identify the opportunities for improvement. DATA SOURCES: Multiple methods of using the NSQIP for practice improvement were explored by using published data and reviewing hospital practices. CONCLUSIONS: NSQIP data can be used by individuals, services, hospitals, and systems to improve outcomes. It fulfills the current and likely future requirements for Part IV of Maintenance of Certification. PMID- 19874934 TI - Outcomes of care of abdominal aortic aneurysm in Veterans Health Administration facilities: results from the National Surgical Quality Improvement Program. AB - This report describes outcomes of care for abdominal aortic aneurysms (AAAs), along with methods used by the Veterans Affairs (VA) National Surgical Quality Improvement Program (NSQIP) in tracking, monitoring, and improving surgical results in VA facilities. Since the inception of NSQIP in 1994, a continual drop in overall surgical mortality, along with decreased morbidity, has occurred. A parallel improvement in results of vascular surgery and AAA repair was also observed. Soon after introduction of endovascular aneurysm repair (EVAR), with Food and Drug Administration device approval in 1999, robust electronic NSQIP records immediately began to capture individual facility performances and outcomes for both types of AAA repair. The NSQIP data center provided actual and risk-adjusted analyses for both procedures semiannually. These analyses have been used by its executive board to provide recommendations, often based on site visits, to improve outcomes. Requirements for reporting of facility-specific data and feedback, paper audits, and site visits appear to relate directly to improved AAA care. Veterans Health Administration (VHA) outcomes of AAA repair are comparable to those reported nationally and internationally and have continued to improve in recent years. National VHA initiatives, based on data feedback and active oversight, relate to some of the lowest AAA mortality rates available. This review describes past, present, and possible future NSQIP strategies to improve outcomes for AAA repair with general comments about recent alternative proposals. PMID- 19874935 TI - The Michigan Surgical Quality Collaborative: a legacy of Shukri Khuri. AB - BACKGROUND: From the legacy of Shukri Khuri, we have successfully implemented a regional quality collaborative in Michigan, the Michigan Surgical Quality Collaborative (MSQC). METHODS: The MSQC represents a partnership between the American College of Surgeons (ACS), 34 Michigan hospitals, and a large private payer. It is based on a "pay for participation" rather than a "pay for performance" model. Although based on the ACS National Surgical Quality Improvement Program (NSQIP) platform, this collaborative has a unique infrastructure for information technology, collaboration, and ad hoc quality improvement (QI) initiatives. RESULTS: Specific initiatives have been implemented with colectomy, myocardial ischemia, and surgical site infection (SSI). Based on these initiatives, best practices have been implemented. Adherence to these best practices is modest, but despite this, there has been significant QI. CONCLUSIONS: The improved quality was likely the result of diverse process measures, many not yet recognized in the literature, which came together effectively in specific hospitals. PMID- 19874936 TI - New approaches to the National Surgical Quality Improvement Program: the American College of Surgeons experience. AB - In honor of the seminal contributions of Dr. Shukri Khuri to the foundation and development of the National Surgical Quality Improvement Program (NSQIP), a review of recent work and new directions within the American College of Surgeons (ACS) NSQIP is presented, according to the following outline: PMID- 19874937 TI - Using administrative data to identify surgical adverse events: an introduction to the Patient Safety Indicators. AB - BACKGROUND: The Patient Safety Indicators (PSIs) are algorithms based on the International Classification of Diseases, Ninth Revision, Clinical Modification, aimed at identifying potential safety-related adverse events through the automated screening of readily available administrative databases. Many of these indicators focus on surgical care, and a few have been endorsed by the National Quality Forum as performance measures. The aim of this report is to give a brief overview of the development and definitions of the PSIs as well as the current evidence for their validity, compared with the National Surgical Quality Improvement Program and chart abstraction designed for the purpose of PSI validation. METHODS: Several articles published in the past few years, in addition to primary data collected from an ongoing study of PSI validation in the Veterans Health Administration, were examined. RESULTS: Selected surgical PSIs have positive predictive values ranging from 22% to 89%, depending on the nature of the PSI and the method of validation used. CONCLUSIONS: With adequate coding revisions, PSI performance can be substantially improved. PMID- 19874938 TI - The National Surgical Quality Improvement Program: learning from the past and moving to the future. AB - The National Surgical Quality Improvement Program (NSQIP) has achieved remarkable success over the 15 years of its existence, initially in the Veterans Health Administration and more recently in private and US Department of Defense hospitals. However, the NSQIP is at a critical juncture because of the cost and other limitations of data collection largely by manual chart abstraction. A potential solution is the documentation of care by surgical teams using the NSQIP data set as the foundation for standardized data that can be reused electronically for multiple other purposes, such as discharge abstracts, billing, and other Centers for Medicare and Medicaid Services and insurer requirements for data. It is likely that the innovative design of portions of the electronic medical record will be time efficient and acceptable to surgical care providers once they experience its advantages. PMID- 19874939 TI - Fifteen years of the National Surgical Quality Improvement Program in review. AB - Since 1994, the National Surgical Quality Improvement Program (NSQIP) has become a tool for the study of outcomes in surgery. Through carefully designed studies, patient risk factors, structures, and processes of care and their impact on various outcomes were carefully described within many specialties and subspecialties of surgery. "Fifteen years of NSQIP" is a celebration of the work of Shukri Khuri and his colleagues during this time frame. By summarizing their extensive contributions, a perspective is given as to the impact and breadth of their observations and recommendations on quality improvement for specific operations in various specialties under various conditions. A total of 128 articles published in the peer-reviewed literature dealing mostly with findings from the Veterans Affairs (VA) hospital system are summarized. PMID- 19874940 TI - Autism: the ups and downs of neuroligin. PMID- 19874941 TI - Micronutrients in parenteral nutrition: too little or too much? The past, present, and recommendations for the future. AB - This research workshop in 2009 grew out of a concern in the United States, Europe, and other countries with advanced medicine that it was time to revisit the parenteral requirements for a number of micronutrients. Critical questions sought to be answered included the following: Were there micronutrients not routinely added that should be part of a parenteral nutrition (PN) formula? Were other micronutrients present but in inappropriate amounts? How are various micronutrient requirements altered in the critically or chronically ill? PMID- 19874943 TI - The addition of choline to parenteral nutrition. AB - Choline is a quaternary amine endogenously synthesized from the amino acid methionine or absorbed via the portal circulation. It is ubiquitous in the diet, although it has a greater presence in organ meats. Choline is an essential component of all cell membranes, and has been considered a required dietary nutrient since 1998 by the US Institute of Medicine's Food and Nutrition Board. Choline is necessary for DNA repair, mediated by its role as a methyl donor. It also serves as the precursor for the neurotransmitter acetylcholine. Evidence has accumulated that hepatic steatosis, which occurs during parenteral nutrition therapy, develops as a result of choline deficiency because endogenous production of choline from parenterally infused methionine is deficient. In addition, memory deficits and skeletal muscle abnormalities have been described, and choline deficiency appears to activate cellular apoptosis. Provision of intravenous choline ameliorates hepatic steatosis associated with parenteral nutrition infusion. PMID- 19874942 TI - Vitamin K in parenteral nutrition. AB - Vitamin K (as phylloquinone and menaquinones) is an essential cofactor for the conversion of peptide-bound glutamate to gamma-carboxy glutamic acid (Gla) residues in a number of specialized Gla-containing proteins. The only unequivocal deficiency outcome is a bleeding syndrome caused by an inability to synthesize active coagulation factors II, VII, IX, and X, although there is growing evidence for roles for vitamin K in bone and vascular health. An adult daily intake of about 100 microg of phylloquinone is recommended for the maintenance of hemostasis. Traditional coagulation tests for assessing vitamin K status are nonspecific and insensitive. Better tests include measurements of circulating vitamin K and inactive proteins such as undercarboxylated forms of factor II and osteocalcin to assess tissue and functional status, respectively. Common risk factors for vitamin K deficiency in the hospitalized patient include inadequate dietary intakes, malabsorption syndromes (especially owing to cholestatic liver disease), antibiotic therapy, and renal insufficiency. Pregnant women and their newborns present a special risk category because of poor placental transport and low concentrations of vitamin K in breast milk. Since 2000, the Food and Drug Administration has mandated that adult parenteral preparations should provide a supplemental amount of 150 microg phylloquinone per day in addition to that present naturally, in variable amounts, in the lipid emulsion. Although this supplemental daily amount is probably beneficial in preventing vitamin K deficiency, it may be excessive for patients taking vitamin K antagonists, such as warfarin, and jeopardize their anticoagulant control. Natural forms of vitamin K have no proven toxicity. PMID- 19874944 TI - Carnitine in parenteral nutrition. AB - Several new functions or metabolic uses of carnitine and improvements in assessment of carnitine status impact carnitine dosing recommendations. Carnitine dosing will likely be customized for patients at different stages of the life cycle and for patients with dysfunction of different organs. Nutrition supplementation of carnitine should be 2-5 mg x kg(-1) x day(-1) and be administrated via the route used for administration of macronutrients. Pharmacologic supplementation of carnitine should be 50-100 mg x kg(-1) x day(-1) and be reserved for the removal of toxic compounds from the body. PMID- 19874945 TI - Copper in parenteral nutrition. AB - Copper is an essential nutrient for humans. Copper is a component of numerous enzymes that affect a wide variety of metabolic processes. Copper deficiency can result in anemia, neutropenia, skeletal abnormalities, and other clinical manifestations. There is no well-established laboratory measurement of body copper status. Copper supplementation is essential in parenteral nutrition to prevent an adverse effect of deficiency. Balance studies indicate that copper requirements in total parenteral nutrition amount to 0.3 mg/day in the adult. For children and infants, the estimated requirement is 20 microg/kg body wt/day. These amounts may have to be decreased in patients with cholestasis. PMID- 19874946 TI - Chromium in parenteral nutrition: too little or too much? AB - Although guidelines for routine parenteral supplements of chromium (Cr) were published, there remain major concerns about the infusion of excess Cr. In addition, little information is available on appropriate dosage for intravenous usage. Cr functions as a regulator of insulin action. In humans, the 3 reported cases of Cr deficiency developed peripheral neuropathy, weight loss, and hyperglycemia. Supplementation of Cr to the parenteral nutrition (PN) solution corrected these abnormalities. For parenteral Cr, concerns arise from the high levels found in sera (up to 40-fold higher) and tissues (10- to 100-fold higher) and their effects on kidneys: In 15 children receiving long-term PN, the glomerular filtration rate was lower than that of non-PN controls and was inversely correlated with Cr indices. Furthermore, in a randomized blinded prospective protocol involving 75 newborns, the group receiving the recommended dose of Cr showed higher levels of creatinine that were positively correlated with Cr intake. Of note, Cr contaminants in PN solutions can increase the amount delivered by 10%-100%. A possible method for estimating adequate Cr to be provided IV is to calculate the amount physiologically absorbed in healthy people. This amount is 10 to 100 times less than the daily recommended parenteral Cr in adults. The accumulated scientific data presented here point to a serious need to lower the recommended amount of parenteral Cr. PMID- 19874947 TI - Manganese in parenteral nutrition: who, when, and why should we supplement? AB - Micronutrient requirements are not fully understood. Parenteral nutrition (PN) usually contains the trace element (TE) manganese (Mn) from fixed-concentration TE supplements. Multiple TE formulations may not be optimal in pediatric and home PN. Moreover, most PN products contain Mn as a ubiquitous contaminant. Excessive Mn can lead to Parkinson-like symptoms resulting from hypermanganesemia. A survey of 40 Australasian hospitals that contributed data on 108 patients to the annual home PN register and a systematic review of the literature were conducted to establish the scope of the potential problem of Mn toxicity in PN patients. Exposure to Mn doses 5-6 times current daily requirements, together with the TE contamination that is reported in PN products, can lead to neurotoxicity. Whole blood levels are more accurate for monitoring and correlate well with signal intensity of magnetic resonance imaging. Current TE formulations restrict prescribing options. The regulatory mechanisms of Mn homeostasis are bypassed via the parenteral route so elimination via the hepatobiliary system is impaired, resulting in tissue or brain accumulation. Published dosage recommendations may be excessive and official guidelines require revision. Variability in clinical practices necessitates that individual TE additives are more widely available and multiple TE products reformulated. More frequent monitoring for any brain accumulation is recommended. The scarcity of PN-associated Mn deficiency, plus the growing evidence for Mn toxicity, leads to the conclusion that it is unnecessary for Mn to be prescribed routinely for pediatric or long-term PN patients. PMID- 19874948 TI - Iodine: it's important in patients that require parenteral nutrition. AB - Iodine deficiency has multiple adverse effects on growth and development because of inadequate thyroid hormone production. Four methods are generally recommended for assessment of iodine nutrition: urinary iodine concentration, thyroid size, and blood concentrations of thyroid-stimulating hormone and thyroglobulin. Iodine intakes < or = 1 mg/d are well tolerated by most adults, because the thyroid is able to adjust to a wide range of intakes. A daily dose of 1 microg iodine/kg body weight is recommended for infants and children receiving parenteral nutrition (PN), but this is far below their requirement. Daily iodine requirements in adults receiving enteral nutrition or PN are estimated to be 70 150 microg, but most PN formulations do not contain iodine. Despite this, deficiency is unlikely because absorption from iodine-containing skin disinfectants and other adventitious sources can provide sufficient iodine. However, if chlorhexidine replaces iodine-containing disinfectants for catheter care, iodine deficiency may occur during long-term PN, and periodic testing of thyroid functions may be prudent. Infants may be particularly vulnerable because of their small thyroidal iodine store, but available data do not yet support routine supplementation of preterm infants with iodine. Adults may be less vulnerable because thyroidal iodine stores may be able to support thyroid hormone production for several months. More studies to clarify this issue would be valuable. PMID- 19874949 TI - Iron and parenteral nutrition. AB - There is ample evidence that iron is an essential trace element, but assessment of iron status and decisions on the amounts needed and the means of delivery in patients on parenteral nutrition (PN) have been unclear. Although iron requirements may diminish during acute illness, the frequent concurrence of blood loss and iron deficiency argue strongly for maintenance of levels of delivery in line with basal requirements. Maintenance of iron delivery has not been thought likely to present risk, but new data are questioning this. The needs of menstruating, pregnant, and lactating women are greater than those of adult men. The evidence favors an intravenous dose of around 1 mg of elemental iron per day in adult men and postmenopausal women. Doses of 1.5 mg/d [DOSAGE ERROR CORRECTED] in menstruating women and 2.0 mg/d [DOSAGE ERROR CORRECTED] for those in the later stages of pregnancy or lactating can be supported. A calibrated response is required in the growing child. Continued monitoring of iron status is recommended. Iron is an essential component for most PN regimens. The quantity of iron to be included should take account of predicted requirements. PMID- 19874950 TI - Micronutrients in parenteral nutrition: boron, silicon, and fluoride. AB - Boron may be beneficial for bone growth and maintenance, central nervous system function, and the inflammatory response, and silicon may be beneficial for bone maintenance and wound healing. Fluoride is not an essential element but amounts provided by contamination may be beneficial for bone strength. Fluoride toxicity may be a concern in parenteral nutrition. Further studies are warranted to determine whether there are optimal amounts of boron and silicon that should be delivered to typical and special population patients receiving parenteral nutrition. In addition, further studies are needed to determine whether providing the dietary guideline of adequate intake amounts of fluoride parenterally would prevent or treat parenteral nutrition osteopenia. PMID- 19874951 TI - Selenium in intravenous nutrition. AB - Selenium (Se) is an essential nutrient for human beings, with serious consequences resulting from clinical deficiency. It therefore should be provided intravenously to all patients who require parenteral nutrition (PN). Moreover, because the effects of suboptimal status are variable and unclear, this supplementation should be provided from the beginning of the course of PN. In most patients receiving PN at home or after surgery, 60-100 mcg/day will meet their requirements. Patients who commence PN already depleted in selenium may require more. Critically ill patients or those with severe burns may have higher requirements. There is good evidence that up to 400 mcg/day is beneficial in burn patients, but the evidence is inconclusive regarding the benefit of high-dose selenium in severe sepsis. Where increased Se provision is used, or in long-term PN, selenium status should be monitored by measurement of plasma Se together with a measure of systemic inflammatory response syndrome, such as C-reactive protein. There are many research issues, including which biochemical measurements best reflect tissue function, especially immune function in seriously ill patients, the clinical consequences of suboptimal biochemical Se status, whether high-dose Se improves outcome in critically ill patients, and whether extra Se always should be given with extra intakes of other antioxidants. PMID- 19874952 TI - Zinc: an essential trace element for parenteral nutrition. AB - Zinc is an essential trace element for human nutrition that is an integral part of many enzyme systems, including DNA polymerase complex. Zinc deficiency has been associated with stunting of growth and sexual immaturity. In children, deficiency causes a fatal condition called acrodermatitis enteropathica. The same syndrome has been observed in patients on total parenteral nutrition (TPN) who do not receive zinc. In TPN the requirements have been estimated by balance studies to be 3 mg/d in patients without gastrointestinal losses and a mean of 12 mg/d in patients with diarrhea and fistula losses. PMID- 19874954 TI - Vitamin D and the parenteral nutrition patient. AB - Vitamin D is a prohormone produced in the skin epidermis when irradiated with sunlight or ultraviolet light B. It is also absorbed from food or supplements. Vitamin D must be converted to 25-hydroxyvitamin D3 (circulating form) and finally to the hormone, 1a,25-dihydroxyvitamin D3, before it can function. This hormone acts through a single nuclear receptor. The details of these conversions and molecular biology of the action of vitamin D3 are summarized. The physiologic functions of vitamin D have been expanded beyond the mineralization of the skeleton to include modulation of the immune system, terminal differentiation in several tissues, suppression of malignant cells, and anabolic activity in the skeleton and in the renal-cardiovascular system. Epidemiologic studies have associated vitamin D deficiency with an increased risk of colorectal and breast cancers and an increased risk of autoimmune diseases, such as multiple sclerosis, type 1 diabetes, and cardiovascular events. Thus, vitamin D is essential not only for the skeleton but also many other organ systems. Recommendations for 25 hydroxyvitamin D3 levels for PN patients are presented. PMID- 19874953 TI - Vitamin C requirements in parenteral nutrition. AB - Some biochemical functions of vitamin C make it an essential component of parenteral nutrition (PN) and an important therapeutic supplement in other acute conditions. Ascorbic acid is a strong aqueous antioxidant and is a cofactor for several enzymes. The average body pool of vitamin C is 1.5 g, of which 3%-4% (40 60 mg) is used daily. Steady state is maintained with 60 mg/d in nonsmokers and 140 mg/d in smokers. Shocked surgical, trauma, and septic patients have a drastic reduction of circulating plasma ascorbate concentrations. These low concentrations require 3-g doses/d to restore normal plasma ascorbate concentrations, questioning the recommended PN dose of 100 mg/d. Determination of intravenous requirements is usually based on plasma concentrations, which are altered during the inflammatory response. There is no clear indicator of deficiency: serum or plasma ascorbate concentrations <0.3 mg/dL (20 micromol/L) indicates inadequate vitamin C status. On the basis of available pharmacokinetic data the 100 mg/d dose for patients receiving home PN and 200 mg/d for stable adult patients receiving PN are adequate, but requirements have been shown to be higher in perioperative, trauma, burn, and critically ill patients, paralleling oxidative stress. One recommendation cannot fit all categories of patients. Large vitamin C supplements may be considered in severe critical illness, major trauma, and burns because of increased requirements resulting from oxidative stress and wound healing. Future research should distinguish therapeutic use of high-dose ascorbic acid antioxidant therapy from nutritional PN requirements. PMID- 19874955 TI - Vitamin E requirements in parenteral nutrition. AB - Patients with parenteral nutrition depend on an adequate supply of micronutrients, in particular, antioxidant vitamins and cofactors such as selenium. In cases of oxidative stress (eg, chronic inflammation, sepsis, lung distress syndrome, and organ failure), there is a higher need for antioxidants. One of the most important antioxidant vitamins is vitamin E. For very low birth weight infants the plasma level is an indicator for adequate supply and for safety. Safe and effective blood levels are between 23 and 46 micromol/L, maintained with a dose of 2.8 IU/kg body weight (1-2 mg/day). For safety reasons a plasma level of 80 micromol/L should not be exceeded. For adults, 10 IU/day (9.1 mg/day) are recommended. Whether this dose is sufficient to ensure body stores and sufficient antioxidant activity is controversial. If parenteral lipid emulsions are supplied there is an additional need for vitamin E to protect the lipids (polyunsaturated fatty acids) from lipid peroxidation and to deliver additional vitamin E. Dietary guidelines for healthy adults recommend an intake of polyunsaturated fatty acids equal to 10% of total energy and an intake of alpha-tocopherol greater than 0.4 mg/g of polyunsaturated fatty acids. Randomized clinical trials are performed using special formulations of vitamin E solutions because vitamin E is available only in lipid emulsions to protect lipids, but not in an isolated solution for parenteral supply. PMID- 19874957 TI - Cultural neuroscience. Preface. PMID- 19874958 TI - Controlled studies of chimpanzee cultural transmission. AB - Following the first long-term field studies of chimpanzees in the 1960s, researchers began to suspect that chimpanzees from different African populations varied in their behavior, and that some of these variations were transmitted through social learning, thus suggesting culture. Additional reports of chimpanzee culture have since accumulated, which involve an increasing amount of behavioral variation that has no obvious ecological or genetic explanation. To date, close to 50 cultural variants have been reported, including subsistence behavior, tool-use, communication signals, and grooming patterns. Nevertheless, field studies lack the experimental controls and manipulations necessary to conclusively demonstrate that the observed variation results from differential invention and social transmission of behavior. This would require that behavioral variants have been learned from others, a question best addressed in a controlled experimental setting. The following chapter details a series of experimental studies at Yerkes National Primate Research Center of Emory University. In each case, the behavior of two captive groups (each N=12 individuals) was compared before and after the introduction of a novel foraging behavior by a trained conspecific "inventor." The studies were designed to investigate (i) the conditions under which chimpanzees learn from one another, (ii) how behaviors are transmitted, (iii) how cultures are maintained over generations. The results emphasize the importance of integrating both fieldwork and experimental approaches. Previous studies have reported deficits in chimpanzees' cultural capacities, but did so after testing them with human models, which are largely irrelevant to the problem at hand. A representative understanding of culture can only be gained when efforts are made to create a naturalistic learning environment in which chimpanzees have opportunities to learn spontaneously from conspecifics in a familiar social setting. PMID- 19874959 TI - Brain in macro experiential context: biocultural co-construction of lifespan neurocognitive development. AB - For more than a century, neuroscientists have recognized that the brain is an open, adaptive system and that the organism's experiences are environmentally contextualized. However, the proposition that socio-cultural contexts may exert reciprocal influences on neurobiological mechanisms is rarely considered and could not be empirically explored until very recently. This article reviews the emerging trend of interdisciplinary research aiming at exploring the effects of socio-cultural influences on human brain functioning. Recent co-constructive views of brain development and functioning and empirical evidence of developmental plasticity at different levels are reviewed. Empirical findings that are indicative of reciprocal influences of social contexts, culture-specific language environment, and expertise training are highlighted. The quest to understand how individual brains get personalized through lifespan development that takes place in the macro socio-cultural experiential context is still at an embryonic stage. Nevertheless, studies reviewed here indicate that new conceptual and empirical opportunities for this endeavor are emerging. PMID- 19874960 TI - Anthropology and cultural neuroscience: creating productive intersections in parallel fields. AB - Partly due to the failure of anthropology to productively engage the fields of psychology and neuroscience, investigations in cultural neuroscience have occurred largely without the active involvement of anthropologists or anthropological theory. Dramatic advances in the tools and findings of social neuroscience have emerged in parallel with significant advances in anthropology that connect social and political-economic processes with fine-grained descriptions of individual experience and behavior. We describe four domains of inquiry that follow from these recent developments, and provide suggestions for intersections between anthropological tools - such as social theory, ethnography, and quantitative modeling of cultural models - and cultural neuroscience. These domains are: the sociocultural construction of emotion, status and dominance, the embodiment of social information, and the dual social and biological nature of ritual. Anthropology can help locate unique or interesting populations and phenomena for cultural neuroscience research. Anthropological tools can also help "drill down" to investigate key socialization processes accountable for cross group differences. Furthermore, anthropological research points at meaningful underlying complexity in assumed relationships between social forces and biological outcomes. Finally, ethnographic knowledge of cultural content can aid with the development of ecologically relevant stimuli for use in experimental protocols. PMID- 19874961 TI - The brain in culture and culture in the brain: a review of core issues in neuroanthropology. AB - Neuroanthropology is a new field of research that can make two distinctive contributions to our understanding of the brain-culture nexus. The first contribution has to do with the question of how socially shared meanings and practices are reflected in brain function and structure - the culture in the brain problem. Neuroanthropology's second contribution relates to the neural processes that generate socially shared meanings and practices - the brain in culture problem. Research in cultural neuroscience has focused on the first question while research in social neuroscience has a bearing on the second. A neuroanthropological perspective is vital to integrate these two most important dimensions of the human condition. In this paper we review research from cultural anthropology, primatology, and developmental psychology, in addition to social and cultural neuroscience, that deals with these two core neuroanthropological issues. Regarding the brain in culture problem, the review reveals that relational recoding is the basis of a host of cognitive functions that enable the formation of socially shared meanings and practices. The review also shows that relational recoding corresponds to the processing style characteristic of the prefrontal cortex (PFC). With respect to the culture in the brain problem, the most salient finding is the extent and breadth of the influence of culture on the brain: literally all brain areas, cortical and subcortical, respond to regularities in the cultural stream of experience. Furthermore, culture not only shapes preexisting patterns of neural activity but it may also determine whether a pattern is at all present. In addition to influencing brain function culture also changes the structure of the brain. The review finally indicates that cultural regularities can modulate cognitive function both implicitly and explicitly. Overall, the PFC can be regarded as the structure that establishes relationships between things and events that are represented in the different areas distributed across the brain. These areas become in this manner more readily available for modulation or constitution by (cultural) experience. However, the PFC is the structure that stands first to be modified or constituted by cultural experience as it is the structure that lays culture's foundations. PMID- 19874962 TI - Cultural constraints on music perception and cognition. AB - Research suggests that music, like language, is both a biological predisposition and a cultural universal. While humans naturally attend to and process many of the psychophysical cues present in musical information, there is a great - and often culture-specific - diversity of musical practices differentiated in part by form, timbre, pitch, rhythm, and other structural elements. Musical interactions situated within a given cultural context begin to influence human responses to music as early as one year of age. Despite the world's diversity of musical cultures, the majority of research in cognitive psychology and the cognitive neuroscience of music has been conducted on subjects and stimuli from Western music cultures. From the standpoint of cognitive neuroscience, identification of fundamental cognitive and neurological processes associated with music requires ascertaining that such processes are demonstrated by listeners from a broad range of cultural backgrounds and in relation to various musics across cultural traditions. This chapter will review current research regarding the role of enculturation in music perception and cognition and the degree to which cultural influences are reflected in brain function. Exploring music cognition from the standpoint of culture will lead to a better understanding of the core processes underlying perception and how those processes give rise to the world's diversity of music forms and expressions. PMID- 19874963 TI - Culture and attention: evidence from brain and behavior. AB - Research has demonstrated that our experiences, including the culture in which we are raised, shape how we attend to and perceive the world. Behavioral studies have found that individuals raised in Western cultures tend toward analytic processing and prefer tasks emphasizing independent contexts rather than tasks emphasizing interdependent contexts. The opposite is true for individuals raised in East Asian cultures, who tend toward holistic processing and prefer tasks emphasizing interdependent contexts. Recently, cognitive neuroscientists have extended these behavioral findings to examine the brain activity of individuals from different cultures during the performance of cognitive tasks. Results from these initial studies indicate that culture may shape how the brain processes even very abstract stimuli and may influence the features of the environment to which individuals attend. The present chapter reviews evidence that culture influences attention and related systems, which, in turn, impact other cognitive and social processes and their neural correlates. PMID- 19874964 TI - Culture sculpts the perceptual brain. AB - Cultural differences in the way Westerners and East Asians perceive and attend to visual objects and contexts have now been shown across many behavioral studies. Westerners display more attention to objects and their features, in line with an analytic processing style, whereas East Asians attend more to contextual relationship, reflecting holistic processing. In this article, we review these behavioral differences and relate them to neuroimaging studies that show the impact of cultural differences even on ventral visual processing of objects and contexts. We additionally consider the evidence showing how extended experience within a culture via aging affects ventral visual function. We conclude that the brain findings are in agreement with the analytic/holistic dichotomy of Western and East Asian visual processing styles. Westerners engage greater object processing activity while East Asians engage more context-processing activity in the ventral visual areas of the brain. Although such cultural imaging studies are still few, they provide important early evidence supporting the importance of cultural experiences in sculpting visual processing at the neural level. PMID- 19874965 TI - Neuropsychological assessment of African children: evidence for a universal brain/behavior omnibus within a coconstructivist paradigm. AB - Cross-cultural neuropsychology with African and American children provides evidence of consistent deficit patterns in attention, working memory, and learning in children at risk from disease affecting brain function by means of similar pathophysiologic mechanisms (e.g., cerebral malaria (CM) and sickle-cell disease (SCD); HIV in African and American children). These brain-behavior disease processes are also modified in a consistent manner cross-culturally by quality of developmental milieu and caregiving. We then present findings from the pioneering use of computerized cognitive rehabilitation therapy (CCRT) with Ugandan children surviving CM and with HIV. This neuropsychological evidence that CCRT enhances positive brain plasticity in a consistent manner across cultures supports the "coconstructive" paradigm (Li, 2003), since plasticity across the life span is the hallmark of this approach. Coconstructivism is a holistic multi dimensional approach that emphasizes reciprocal biocultural influences across the life span. It also emphasizes the reciprocal interaction of culture and the genome in shaping brain/mind at multiple levels: neurobiological, cognitively, behavioral, and sociocultural (Li, 2003). Cross-cultural neuropsychology in healthy and diseased brains, brain imaging technologies, and genomic research can triangulate the manner in which a universal brain/behavior omnibus drives plasticity across the life span. As such, the further scientific characterization of the brain/behavior omnibus can provide the vital lynchpin between biology and culture in Li's coconstructive paradigm, revolutionizing our understanding of intelligence and culture. PMID- 19874966 TI - Cultural influences on memory. AB - Research reveals dramatic differences in the ways that people from different cultures perceive the world around them. Individuals from Western cultures tend to focus on that which is object-based, categorically related, or self-relevant whereas people from Eastern cultures tend to focus more on contextual details, similarities, and group-relevant information. These different ways of perceiving the world suggest that culture operates as a lens that directs attention and filters the processing of the environment into memory. The present review describes the behavioral and neural studies exploring the contribution of culture to long-term memory and related processes. By reviewing the extant data on the role of various neural regions in memory and considering unifying frameworks such as a memory specificity approach, we identify some promising directions for future research. PMID- 19874967 TI - Numbers in the cultural brain. AB - Recent functional neuroimaging studies have indicated that culture may contribute to differential representation of Arabic numbers in the brain of Chinese and English speakers. The brain networks underlying even very simple arithmetic operation differ among these groups. To what extent do different cultures lead to differences in functional connectivity among the distributed brain areas that constitute the network supporting numerical and arithmetic processes? Key cultural differences are educational system, learning strategy, reading experience, and even genetic background; which ones are important? This review addresses these questions and summarizes findings from recent research on number/arithmetic cognition as well related studies in other cognitive domains. Future directions are also addressed. PMID- 19874969 TI - Culture in the mind's mirror: how anthropology and neuroscience can inform a model of the neural substrate for cultural imitative learning. AB - Cultural neuroscience, the study of how cultural experience shapes the brain, is an emerging subdiscipline in the neurosciences. Yet, a foundational question to the study of culture and the brain remains neglected by neuroscientific inquiry: "How does cultural information get into the brain in the first place?" Fortunately, the tools needed to explore the neural architecture of cultural learning - anthropological theories and cognitive neuroscience methodologies - already exist; they are merely separated by disciplinary boundaries. Here we review anthropological theories of cultural learning derived from fieldwork and modeling; since cultural learning theory suggests that sophisticated imitation abilities are at the core of human cultural learning, we focus our review on cultural imitative learning. Accordingly we proceed to discuss the neural underpinnings of imitation and other mechanisms important for cultural learning: learning biases, mental state attribution, and reinforcement learning. Using cultural neuroscience theory and cognitive neuroscience research as our guides, we then propose a preliminary model of the neural architecture of cultural learning. Finally, we discuss future studies needed to test this model and fully explore and explain the neural underpinnings of cultural imitative learning. PMID- 19874968 TI - Cultural neurolinguistics. AB - As the only species that evolved to possess a language faculty, humans have been surprisingly generative in creating a diverse array of language systems. These systems vary in phonology, morphology, syntax, and written forms. Before the advent of modern brain-imaging techniques, little was known about how differences across languages are reflected in the brain. This chapter aims to provide an overview of an emerging area of research - cultural neurolinguistics - that examines systematic cross-cultural/crosslinguistic variations in the neural networks of languages. We first briefly describe general brain networks for written and spoken languages. We then discuss language-specific brain regions by highlighting differences in neural bases of different scripts (logographic vs. alphabetic scripts), orthographies (transparent vs. nontransparent orthographies), and tonality (tonal vs. atonal languages). We also discuss neural basis of second language and the role of native language experience in second language acquisition. In the last section, we outline a general model that integrates culture and neural bases of language and discuss future directions of research in this area. PMID- 19874970 TI - The cultural neuroscience of person perception. AB - In the last few years, theorists have argued that culture can shape processes of basic visual perception. This work has primarily focused on cultural influences in nonsocial domains, such as cross-cultural differences in seeing and attending to focal stimuli versus backgrounds. Recently, researchers have begun to examine how culture can shape processes of social perception. We review such evidence and describe how culture tunes both the outcomes of social perception (as revealed in behavioral responses) as well as the activity of the neural mechanisms that mediate these outcomes. Such evidence comes from the domains of emotion recognition, social status perception, social group evaluation, and mental state inference. We explicate these findings through our viewpoint that ecologically important aspects of the sociocultural environment shape perceptual processing and its neural basis. More broadly, we discuss the promise of a cultural neuroscience approach to social perception and some of its epistemological challenges as a nascent interdisciplinary enterprise. PMID- 19874971 TI - Understanding the self: a cultural neuroscience approach. AB - The self has been addressed extensively by philosophers and psychologists from different cultures. Recent cognitive neuroscience studies have uncovered neural substrates underlying the processing of different aspects of the self. As social psychologists have shown evidence for differences in self-construal styles between Western and East Asian cultures, recent transcultural neuroimaging research sought to find potential neural mechanisms mediating cultural specific self-related processing. The findings of transcultural neuroimaging research help to understand the culture-dependent nature of the self and its underlying neural substrates. This also sheds light on how to conceptualize the self in psychological and philosophical terms. PMID- 19874972 TI - Cultural effects on the neural basis of theory of mind. AB - "Theory of mind" has been described as the ability to attribute and understand other people's desires and intentions as distinct from one's own. It has been found to develop as early as between 3 and 4 years old, with precursor abilities possibly developing much earlier. There has been debate about the extent to which the developmental trajectory of theory of mind may differ across cultures or language systems. Although very few neuroimaging studies have directly compared different groups from different culture and language systems, across studies of a number of cultural/language groups have been used to explore the neural correlates of theory of mind. A summary of these findings suggests that there may be both universal and culture or language-specific neural correlates related to theory of mind. These studies, while still preliminary in many ways, illustrate the importance of taking into account the cultural background of participants. Furthermore these results suggest that there may be important cultural influence on theory of mind and the neural correlates associated with this ability. PMID- 19874973 TI - Culture and social support: neural bases and biological impact. AB - Social support is an effective means by which people cope with stressful events, and consequently, it beneficially affects health and well-being. Yet there are profound cultural differences in the effectiveness of different types of support and how people use their support networks. In this paper, we examine research on the impact of culture on social support, the neural underpinnings of social support, and how cultural differences in social support seeking are manifested biologically. We focus on cultural factors that may affect individuals' decisions to seek or not to seek social support and how culture moderates the impact of support seeking on biological and psychological health outcomes. We also examine recent research on the interaction between genes and culture in social support use. Discussion centers on the importance of developing an overarching framework of social support that integrates health psychology, cultural psychology, social neuroscience, and genetics. PMID- 19874974 TI - Neuroeconomics: in search of the neural representation of brands. AB - In modern economy the customer is confronted with a huge amount of consumer goods. In this situation, culturally based brands seem to play an important role in establishing strong emotional bonds between customers and goods and to guide people's economic behavior by biasing selections and preference decisions based on affect. Recently, neuroscientific approaches have demonstrated that cultural objects like brands or brand-related behavior may successfully be investigated with neuroimaging tools like fMRI. First studies suggested that structures associated with the reward circuit (striatum) and the dorsolateral part of the prefrontal cortex may be involved when perceiving a favorite brand. Hence, brands that have been associated with appetitive stimuli due to marketing efforts or cultural factors seem to engage similar brain networks than artificially associated reward stimuli. However, brands have different and complex meanings in our life far beyond representing objects of desire. For example, the possession of goods from certain kinds of brands often is used to mark the social state of the owner and to distinguish him or her from other groups. In particular, luxury goods often seem to have this function. Recent neuroimaging results support this observation by showing that viewing logos of luxury brands is associated with brain activity in the anterior medial prefrontal cortex, a region known to be associated with self-centered cognitions. Thus, it seems that brands of luxury goods improve self-relevant thoughts, pointing to the role of luxury brands to mark the superior position of the owner in society. These results demonstrate that cultural symbols like brands can successfully be examined with neuroimaging approaches. Thus, along with advanced cultural theories, neuroeconomics may provide important contributions to the understanding of brand-related or economic behavior. PMID- 19874975 TI - "Neuroarchaeology": exploring the links between neural and cultural plasticity. AB - This paper aims primarily at two things: The first is to present an overview of the newly developed field of "neuroarchaeology" and discuss its theoretical grounding in Material Engagement Theory (MET) and the extended mind hypothesis. The second is to use the above overview as a basis for advancing some tentative proposals about the role that neuroarchaeology, by placing the mutual constitution of brain, mind, and culture in evolutionary perspective, can play within the field of cultural neuroscience and about the common benefits that can arise out of such a cross-disciplinary coalition. PMID- 19874977 TI - Cultural neuroscience: a once and future discipline. AB - The study of culture and biology has long stood stratified within the social and natural sciences, a gap that physicist C.P. Snow (1959) famously called "the two cultures." Cultural neuroscience is an emerging, interdisciplinary field that examines the bidirectional influence of culture and genes to brain and behavior across multiple timescales. Integrating theory and methods from cultural psychology, brain sciences, and population genetics, cultural neuroscience is the study of how cultural values, practices and beliefs shape brain function and how the human brain gives rise to cultural capacities and their transmission across macro- (e.g., phylogeny, lifespan) and micro timescales (e.g., situation). The current article presents the aims and methods of cultural neuroscience, highlights recent empirical findings in the field, and discusses the potential implications of this field for bridging the social and natural sciences as well as informing interethnic ideology and population health concerns, more broadly construed. PMID- 19874976 TI - Cultural neuroscience and psychopathology: prospects for cultural psychiatry. AB - There is a long tradition that seeks to understand the impact of culture on the causes, form, treatment, and outcome of psychiatric disorders. An early, colonialist literature attributed cultural characteristics and variations in psychopathology and behavior to deficiencies in the brains of colonized peoples. Contemporary research in social and cultural neuroscience holds the promise of moving beyond these invidious comparisons to a more sophisticated understanding of cultural variations in brain function relevant to psychiatry. To achieve this, however, we need better models of the nature of psychopathology and of culture itself. Culture is not simply a set of traits or characteristics shared by people with a common geographic, historical, or ethnic background. Current anthropology understands culture as fluid, flexible systems of discourse, institutions, and practices, which individuals actively use for self-fashioning and social positioning. Globalization introduces new cultural dynamics and demands that we rethink culture in relation to a wider domain of evolving identities, knowledge, and practice. Psychopathology is not reducible to brain dysfunction in either its causes, mechanisms, or expression. In addition to neuropsychiatric disorders, the problems that people bring to psychiatrists may result from disorders in cognition, the personal and social meanings of experience, and the dynamics of interpersonal interactions or social systems and institutions. The shifting meanings of culture and psychopathology have implications for efforts to apply cultural neuroscience to psychiatry. We consider how cultural neuroscience can refine use of culture and its role in psychopathology using the example of adolescent aggression as a symptom of conduct disorder. PMID- 19874979 TI - Industrial biotechnology: Current status and future development for the sustainability of human society. PMID- 19874980 TI - Infection prevention in points of dispensing. AB - BACKGROUND: Community-based points of dispensing (POD) will be used during disasters to distribute mass quantities of anti-infective therapy/prophylaxis and/or vaccination to an entire community in a short period of time. Without proper planning, staff training, and implementation of infection prevention strategies, disease transmission is possible in PODs. The purpose of this paper is to outline infection prevention recommendations for PODs. METHODS: A literature review and Internet search were conducted in April 2009. A spreadsheet was created that delineated infection prevention issues in PODs that were identified by each source. Infection prevention recommendations were divided into themes/domains for simplification and clarity. RESULTS: Thirty-one articles, planning documents/reports, and Web-based training programs were identified and screened. Of these, 19 were deemed relevant: 8 were journals articles; and 11 were published reports, planning documents, and/or training programs. Infection prevention themes for PODs identified in the literature included (1) planning for infection prevention in PODs, (2) screening and triage of visitors, (3) using personal protective equipment, (4) implementing hand hygiene, (4) following food and water safety, (5) performing environmental decontamination, (6) communicating and training staff and visitors, and (7) having occupational health protocols. CONCLUSION: Infection prevention in PODs is important to prevent communicable disease spread. This article can assist emergency managers in developing an infection prevention program for PODs. PMID- 19874981 TI - Risk factors and outcomes of Candida albicans and non-albicans Candida species at a Thai tertiary care center. PMID- 19874982 TI - [Current treatment for idiopathic thrombopenic purpura.59 th Congress of National French Society of Internal Medicine. Ajaccio, june 5th, 2009]. PMID- 19874983 TI - [New therapeutic agents in immunologic idiopathic thrombocytopenic purpura treatment: thrombopoietin receptor agonists]. PMID- 19874984 TI - [Physiopathology of idiopathic thrombopenic purpura]. PMID- 19874985 TI - [Quality of life and idiopathic thrombopenic purpura]. PMID- 19874986 TI - [Diagnostic and therapeutic management of idiopathic thrombopenic purpura]. PMID- 19874987 TI - Leriche syndrome. PMID- 19874988 TI - The sympathetic nervous system in heart failure physiology, pathophysiology, and clinical implications. AB - Heart failure is a syndrome characterized initially by left ventricular dysfunction that triggers countermeasures aimed to restore cardiac output. These responses are compensatory at first but eventually become part of the disease process itself leading to further worsening cardiac function. Among these responses is the activation of the sympathetic nervous system (SNS) that provides inotropic support to the failing heart increasing stroke volume, and peripheral vasoconstriction to maintain mean arterial perfusion pressure, but eventually accelerates disease progression affecting survival. Activation of SNS has been attributed to withdrawal of normal restraining influences and enhancement of excitatory inputs including changes in: 1) peripheral baroreceptor and chemoreceptor reflexes; 2) chemical mediators that control sympathetic outflow; and 3) central integratory sites. The interface between the sympathetic fibers and the cardiovascular system is formed by the adrenergic receptors (ARs). Dysregulation of cardiac beta(1)-AR signaling and transduction are key features of heart failure progression. In contrast, cardiac beta(2)-ARs and alpha(1)-ARs may function in a compensatory fashion to maintain cardiac inotropy. Adrenergic receptor polymorphisms may have an impact on the adaptive mechanisms, susceptibilities, and pharmacological responses of SNS. The beta-AR blockers and the inhibitors of the renin-angiotensin-aldosterone axis form the mainstay of current medical management of chronic heart failure. Conversely, central sympatholytics have proved harmful, whereas sympathomimetic inotropes are still used in selected patients with hemodynamic instability. This review summarizes the changes in SNS in heart failure and examines how modulation of SNS activity may affect morbidity and mortality from this syndrome. PMID- 19874989 TI - Long-term prognostic value of ST-segment resolution in patients treated with fibrinolysis or primary percutaneous coronary intervention results from the DANAMI-2 (DANish trial in acute myocardial infarction-2). AB - OBJECTIVES: The purpose of this study was to determine the prognostic value of ST segment resolution after primary percutaneous coronary intervention (pPCI) versus fibrinolysis. BACKGROUND: Resolution of the ST-segment has been used as a surrogate end point in trials evaluating reperfusion in acute myocardial infarction; however, its prognostic significance may be limited to patients treated with fibrinolysis. METHODS: In the DANAMI-2 (DANish trial in Acute Myocardial Infarction-2) substudy, including 1,421 patients, the ST-segment elevation at baseline, pre-intervention, 90 min, and 4 h was assessed. The ST segment resolution was grouped as follows: 1) complete > or =70%; 2) partial 30% to <70%; and 3) no resolution <30%. End points were 30-day and long-term mortality and reinfarction. RESULTS: The ST-segment resolution at 90 min was more pronounced after pPCI (median 60% vs. 45%, p < 0.0001), and a catch-up phenomenon was observed at 4 h. In the fibrinolysis group, 30-day and long-term mortality rates were significantly higher among patients without ST-segment resolution, whereas reinfarction rates were higher with complete ST-segment resolution. The ST-segment resolution was not associated with the 2 end points in the pPCI group. By multivariate analysis, ST-segment resolution at 4 h was an independent predictor of lower mortality, but higher reinfarction rates among patients receiving fibrinolytic therapy. CONCLUSIONS: The ST-segment resolution at 90 min was more complete after pPCI, suggesting better epicardial and microvascular reperfusion, whereas no difference between treatment strategies was seen at 4 h. The ST-segment resolution at 4 h correlated with decreased mortality, but increased reinfarction rates among patients receiving fibrinolytic therapy, whereas no association was seen for patients receiving pPCI. Consequently, 4-h ST segment resolution remains an important prognosticator after fibrinolysis, but may be overemphasized as a surrogate end point after pPCI. PMID- 19874990 TI - Prognostic value of myocardial infarct size and contractile reserve using magnetic resonance imaging. AB - OBJECTIVES: Our aim was to assess the predictive value of myocardial infarct size assessed with late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI) in medically treated patients with chronic myocardial infarction relative to contractile reserve on low-dose dobutamine magnetic resonance (DSMR) for long term event-free survival. BACKGROUND: Information on the relative merits of scar tissue and contractile reserve to predict long-term prognosis in patients with chronic myocardial infarction is lacking. METHODS: A total of 177 patients with known coronary artery disease and scar tissue on LGE MRI were enrolled. Left ventricular (LV) functional parameters at rest and during low-dose DSMR were assessed, and the wall motion score index was calculated. RESULTS: Eleven patients (6.2%) suffered an event during follow-up (average 20.3 months). Infarct size was a stronger predictor of events than LV ejection fraction and LV volumes at rest and during low-dose DSMR. Myocardial infarct size was used to separate patients at high risk (spatial extent > or =6 segments, n = 98) from those at low risk (spatial extent <6 segments, n = 79) for mortality. In the subgroup of patients at high risk, transmurality of infarct was not a predictor of events. However, the presence of contractile reserve (n = 63) was associated with a significantly higher number of events (12.7%) compared with no change in wall motion score index (6.7%; n = 15; p = 0.008). CONCLUSIONS: Myocardial infarct size on LGE MRI is a stronger predictor of clinical outcome than contractile reserve in medically treated patients with myocardial infarction. In patients with large myocardial scar, the presence of contractile reserve is more important for the prediction of events than scar tissue. PMID- 19874991 TI - Angiotensin-converting enzyme inhibitor therapy at the time of coronary artery bypass surgery: when a friend turns mean-spirited. PMID- 19874992 TI - Effects of high-dose modified-release nicotinic acid on atherosclerosis and vascular function: a randomized, placebo-controlled, magnetic resonance imaging study. AB - OBJECTIVES: Our aim was to determine the effects of high-dose (2 g) nicotinic acid (NA) on progression of atherosclerosis and measures of vascular function. BACKGROUND: NA raises high-density lipoprotein cholesterol (HDL-C) and reduces low-density lipoprotein cholesterol and is widely used as an adjunct to statin therapy in patients with coronary artery disease. Although changes in plasma lipoproteins suggest potential benefit, there is limited evidence of the effects of NA on disease progression when added to contemporary statin treatment. METHODS: We performed a double-blind, randomized, placebo-controlled study of 2 g daily modified-release NA added to statin therapy in 71 patients with low HDL-C (<40 mg/dl) and either: 1) type 2 diabetes with coronary heart disease; or 2) carotid/peripheral atherosclerosis. The primary end point was the change in carotid artery wall area, quantified by magnetic resonance imaging, after 1 year. RESULTS: NA increased HDL-C by 23% and decreased low-density lipoprotein cholesterol by 19%. At 12 months, NA significantly reduced carotid wall area compared with placebo (adjusted treatment difference: -1.64 mm(2) [95% confidence interval: -3.12 to -0.16]; p = 0.03). Mean change in carotid wall area was -1.1 +/- 2.6 mm(2) for NA versus +1.2 +/- 3.0 mm(2) for placebo. In both the treatment and placebo groups, larger plaques were more prone to changes in size (r = 0.4, p = 0.04 for placebo, and r = -0.5, p = 0.02 for NA). CONCLUSIONS: In statin treated patients with low HDL-C, high-dose modified-release NA, compared with placebo, significantly reduces carotid atherosclerosis within 12 months. (Oxford Niaspan Study: Effects of Niaspan on Atherosclerosis and Endothelial Function; NCT00232531). PMID- 19874993 TI - Assessing niacin as an atherosclerosis therapeutic agent valuable insights provided by high-resolution vascular magnetic resonance imaging. PMID- 19874995 TI - High prevalence of abnormal nocturnal oximetry in patients with hypertrophic cardiomyopathy. AB - OBJECTIVES: We sought to determine the prevalence of nocturnal oxygen desaturation and obstructive sleep apnea (OSA) in a population of patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: The coexistence of sleep apnea and HCM, 2 common cardiovascular conditions, has been largely unrecognized in the treatment of patients with HCM. The nocturnal hypoxia-induced hyperadrenergic state in OSA is expected to worsen hemodynamics and outcomes in HCM. METHODS: One hundred subjects with HCM between June 1, 2006, and July 14, 2008, were screened with nocturnal oximetry. Clinical variables were collected for statistical analysis. Oximetry was classified abnormal (suspicion of sleep-disordered breathing) in the presence of repetitive desaturation (> or =5 events/h) followed by a rapid return to baseline oxygen saturation (SaO(2)) level with a decrease of > or =4% and threshold of 90%. RESULTS: Seventy-one (71%) patients with HCM had abnormal nocturnal oximetry (71 +/- 9%, 95% confidence interval: 62% to 80%). Subjects with abnormal oximetry were older (age 59.5 +/- 15.3 years) and more were hypertensive (n = 39 [55%]) than those with normal oximetry (age 45.8 +/- 18.5 years, n = 9 [31%], p < 0.001, p = 0.03). Patients with HCM were more symptomatic in the presence of abnormal oximetry (New York Heart Association functional class II to III) (62% vs. 83%, p = 0.023). HCM patients had a higher prevalence of abnormal nocturnal oximetry (n = 71, 71%) compared with a control group of similar age and sex distribution (n = 49, 49%) (p = 0.001). CONCLUSIONS: Abnormal nocturnal oximetry is common in patients with HCM, suggesting that OSA is prevalent. OSA may impact hemodynamics and symptoms in HCM. Further studies are needed to determine the long-term benefit of OSA treatment on hemodynamics and disease progression in HCM. PMID- 19874996 TI - Obstructive sleep apnea a respiratory syndrome with protean cardiovascular manifestations. PMID- 19874994 TI - Triggering of nocturnal arrhythmias by sleep-disordered breathing events. AB - OBJECTIVES: This study sought to evaluate respiratory disturbances as potential triggers for arrhythmia in patients with sleep-disordered breathing (SDB). BACKGROUND: SDB is associated with an increased risk of atrial fibrillation and nonsustained ventricular tachycardia (NSVT) as well as a predilection for sudden cardiac death during nocturnal sleeping hours. However, prior research has not established whether respiratory disturbances operate as triggers for nocturnal arrhythmias. METHODS: Overnight polysomnograms from the Sleep Heart Health Study (n = 2,816) were screened for paroxysmal atrial fibrillation and NSVT. We used the case-crossover design to determine whether apneas and/or hypopneas are temporally associated with episodes of paroxysmal atrial fibrillation or NSVT. For each arrhythmia, 3 periods of sinus rhythm were identified as control intervals. Polysomnograms were examined for the presence of respiratory disturbances, oxygen desaturations, and cortical arousals within a 90-s hazard period preceding each arrhythmia or control period. RESULTS: Fifty-seven participants with a wide range of SDB contributed 62 arrhythmias (76% NSVT). The odds of an arrhythmia after a respiratory disturbance were nearly 18 times (odds ratio: 17.5; 95% confidence interval: 5.3 to 58.4) the odds of an arrhythmia occurring after normal breathing. The absolute rate of arrhythmia associated with respiratory disturbances was low (1 excess arrhythmia per 40,000 respiratory disturbances). Neither hypoxia nor electroencephalogram-defined arousals alone increased arrhythmia risk. CONCLUSIONS: Although the absolute arrhythmia rate is low, the relative risk of paroxysmal atrial fibrillation and NSVT during sleep is markedly increased shortly after a respiratory disturbance. These results support a direct temporal link between SDB events and the development of these arrhythmias. PMID- 19874997 TI - Repaired coarctation of the aorta imaged by 64-detector computed tomography. PMID- 19874998 TI - President's page: who owns what or whom? PMID- 19875000 TI - [Dabigatran (Pradaxa): efficacy and safety]. AB - There is considerable interest in developing new, orally available anticoagulants for the prevention and treatment of thrombotic disorders. In Europe, the low molecular-weight heparins (LMWHs) are more commonly prescribed for thrombosis prevention, but require parenteral administration, platelets monitoring twice a week during the first month. Furthermore, LMWH are not synthetic. All of these characteristics can be an obstacle to optimal patient care, particularly when outpatient dosing is required after early discharge. New oral anticoagulants that require no monitoring and can be administered in a fixed dose without drug-drug and drug-food interactions would clearly offer practical advantages if shown to be safe and effective. dabigatran etexilate, a new oral, direct thrombin inhibitor, is the prodrug of the active compound dabigatran, which binds reversibly to thrombin with high affinity and specificity. This agent has a rapid onset of action, a predictable and reproducible that permit once-daily dosing. To date, more than 8,000 patients have been studied in clinical trials, and more than 38,000 individuals are enrolled in ongoing trials. Three major prospective, randomized, double-blind non-inferiority trials have compared the efficacy and safety of dabigatran etexilate (150 mg or 220 mg once-daily) starting postoperatively, with subcutaneous enoxaparin, in patients undergoing hip (RE NOVATE trial) or knee arthroplasty (RE-MOBILIZE and RE-MODEL). Based on these trial results, dabigatran etexilate is approved for use in the European Union and Canada for primary prevention of VTE in patients having undergone elective total hip and knee arthroplasty. Pradaxa is now on the market in France since December 2008. PMID- 19874999 TI - [Dabigatran etexilate: a major progress in anticoagulant therapy]. PMID- 19875001 TI - [Prevention of intraoperative venous thromboembolism: what are the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition)?]. AB - Extensive evidence related to thromboembolism risk and its prevention are available to guide health care providers. The 8th ACCP Evidence-Based Clinical Practice Guidelines were published in June 2008. The chapter on venous thromboembolism prophylaxis is the result of the collaboration of six senior authors with expertise in thrombosis, surgery, medicine, and critical appraisal. The methodology and the philosophy of these guidelines are explained in this paper and the major recommendations dealing with perioperative thromboprophylaxis are summarized. PMID- 19875002 TI - [Antithrombotic prophylaxis after THA and TKA: the surgeon's point of view]. AB - Total hip arthroplasty (THA) and total knee arthroplasty (PTG) are surgical interventions aiming at functional improvement. They therefore cannot accommodate any "collateral damage" produced, notably by symptomatic thromboembolic events (STE). Use of the necessary thromboprophylaxis has made STEs rare (<3% after THA and 2% after TKA). Pulmonary embolism (PE) is exceptional (0.3%) and only accounts for 15% of the deaths occurring in the 1st postoperative month. However, atherothrombotic disease is significantly associated with thromboembolic venous disease. The causes of STEs are mechanical, directly related to surgical maneuvers, but also biological (familial or acquired thrombophilia, hypercoagulability, particularly associated with hip surgery). Delayed resumption of walking, which promotes venous stasis, has been improved by modern pain management techniques. There is consensus on the need to prolong thromboprophylaxis after THA, but it is more controversial after TKA and depends on the added risk factors. In France, prolonged prevention is widespread. The relatively low STE rate should be put into perspective with the risk of hemorrhage. The surgeon should be particularly attentive to the risk of bleeding at the operative site because it generates a risk of sepsis, and a risk of stiffness for TKA. The risk of hemorrhage essentially results from the misuse of all the anticoagulants, particularly observed with the anti-vitamin K medications because their use is more restricted. The risk of hemorrhage has become quite comparable to the risk of thromboembolism with prophylaxis. To prevent this event, the prescriber must know the characteristics of each drug : Tmax, half life, mode of elimination, as well as the risk of accumulation in the patient receiving such treatment (creatinine clearance). Currently, the thrombohemorrhagic risk for each patient must be assessed. Per os treatment with Dabigatran etexilate is highly advantageous because it is easy to use, there is no thrombopenia induced by heparin, and there is no need for complementary monitoring exams, thus reducing costs. Efficacy in terms of prevention and hemorrhagic risk, demonstrated in phase II studies, must be confirmed by widespread used in real-life conditions. PMID- 19875003 TI - [Anticoagulants drugs direct trombin inhibitors]. AB - The aim of this review is to explain the central role of thrombin in haemostasis and the main pharmacological features of the anticoagulants that are direct inhibitors of thrombin, with emphasis on orally active small molecules. Owing to the complexity of the clotting system only well designed and conducted studies can tell us which drug is the most useful, safe and convenient to limit each type of thrombosis and what are the appropriate dosage and management. Parenterally administered direct thrombin inhibitors require laboratory monitoring, whereas dabigatran, orally active, does not. PMID- 19875004 TI - [Perspectives in cardiology: evidence of efficacy in atrial fibrillation and hopes in acute coronary syndrome]. AB - New antithrombotic drugs, antithrombin or anti Xa, will probably be very useful in cardiology. Two directions are interesting: in one hand atrial fibrillation, in which the unmet need concern drugs as effective as vitamine K antagonists but easier to use. On the other hand, in acute coronary syndrome the situation is different, there are many antithrombotic drugs available but there is still a place for innovative drugs which could provide a gain in terms of efficacy, but the hemorrhagic risk must remain acceptable. In atrial fibrillation, the RELY trial, performed in 18,113 patients has demonstrated, as compared to warfarin, a non inferiority of dabigatran at the dose of 110 mg BID and a superiority of dabigatran at 150 mg BID with a reduction of 34% of the primary endpoint, i.e.stroke and systemic embolism. PMID- 19875005 TI - [Dabigatran: clinical pharmacology]. AB - Dabigatran (Pradaxa) is a new oral, direct, selective and reversible inhibitor of the factor IIa of the coagulation cascade. The main pharmacokinetic characteristics of dabigatran are a bioavailability of approximately 7.5%, a maximum concentration obtained in 0.5 to 2 hours, a terminal half-life of elimination of 7 to 17 hours, a renal way of elimination, 80% as unchanged form and 20% as glucuronide conjugate. The main sources of variability are the renal function, the gastric motility, especially during the early post-operative period and a potential interaction with amiodarone. This compound can be orally administrated, once or twice daily, without any biological monitoring and without any need for dose adjustment. There is a contra-indication in case of severe renal or liver insufficiency. Two phases II with 2287 patients were carried out to for venous thromboembolic (VTE) prophylaxis after major orthopaedic surgery, showing that 150 mg and 220 mg once daily could be the optimal dose regimen to assess in phase III. One phase II with 502 patients vas carried out for the prevention of thromboembolic complications of atrial fibrillation (AF) showing that 110 mg or 150 mg twice daily could be the optimal dose regimen to evaluate in the following phases 3. From this study in AF patients, a dose regimen of 150 mg bid has been chosen to be evaluated for the treatment of VTE. No strong signal for a potential liver toxicity was shown during these studies. PMID- 19875006 TI - Laparoscopic aortic surgery in obese patients. AB - BACKGROUND: Our objective was to demonstrate the feasibility of laparoscopic abdominal aortic aneurysm (AAA) repair in obese patients and to confirm advantages observed with laparoscopic techniques in other surgical specialties regarding pulmonary and parietal complications in this population. METHODS: Between November 2000 and December 2007 we performed 37 laparoscopic aortic reconstructions in obese patients (body mass index [BMI] > 30 kg/m(2)). Median BMI was 31.9 kg/m(2) (range 30.1-40). Twenty-seven patients (73%) were operated for AAA and 10 (27%) for TASC C or D aortoiliac occlusive disease. Data were gathered prospectively and analyzed retrospectively. RESULTS: Aortic exposure was totally laparoscopic in 36 patients (97.3%). Median operative time was 290 min (range 160-480). Median duration of clamping was 77.5 min (range 40-105). Orotracheal extubation was possible before H24 for 35 patients (95%). Median lengths of intensive care unit stay and hospital stay were, respectively, 48 hr (range 12-624) and 8 days (range 4-35). One patient (2.7%) died postoperatively because of colonic ischemia. Five systemic postoperative complications were observed in 36 patients who survived (13.5%) including major nonlethal postoperative complications in two patients (pneumopathy and acute hemodynamic lung edema). All other patients had a fast recovery, with minimal wound discomfort and rapid return to general diet and ambulation, with a median follow up of 21.5 months (range 1-78). One patient was lost. Complete recovery was observed in 35 other patients, and all grafts were patent at last follow-up. No graft infection was observed, and none of our patients presented incisional hernia. CONCLUSION: Obesity is not an operative risk factor for laparoscopic aortic surgery. Our results confirm its feasibility and durability for this high risk population. Laparoscopy should be considered as the technique of choice whenever direct AAA repair is planned in obese patients. PMID- 19875007 TI - Infrarenal iterative aortic surgery: early and late morbi-mortality observed in 61 patients. AB - The aim of this study was to analyze the early and late results of iterative aortic surgery after bypass of infrarenal aorta. Results from Clermont-Ferrand and Saint-Etienne hospitals have been collected. Between January 1993 and December 2001, 61 patients (59 men and two women, mean age 65 years) underwent a partial or complete second aortic reconstruction through a direct approach. Three different indications that required redo surgery were detected. Twenty-three patients presented with an infection (37%), 17 with an occlusive pathology (28%), and 21 with an aneurysm (34%). Medical or endoluminal treatment could no longer be considered. Mean period of time for redo surgery was 101 months (range 1-294). Eighteen of the procedures were emergency surgeries. A polyester prosthesis was used in 45 cases, an arterial allograft in 15 cases, and autogenous venous material in one case. In 22 cases (36%) a visceral, renal, or infracrural revascularization was associated. Four patients died (6.5%): three with an infection and one with an occlusive pathology. Global morbidity rate was 64%. Twelve vascular surgical complications (19%) required redo surgery: seven limb ischemia, three hemorrhage, and two colic ischemia. The preoperative factors generating severe complications were a septic context, renal insufficiency, and American Society of Anesthesiologists grade 3 or 4. Follow-up concerned the 57 surviving patients with a 43-month mean period of time (range 4-105). Actuarial survival rate was 80.7% at 3 years and could be compared to that observed after infrarenal aortic first surgery. Primary and secondary global patency rates were, respectively, 66.4 +/- 6.7% and 94.6 +/- 3% at 3 years with no major amputation. In our series including 37% of septic patients and nearly 30% of patients operated on in emergency, aortic iterative surgery led to mortality and morbidity rates twice and four times as important as those resulting from infrarenal aortic initial surgery, respectively. In the long term, patient survival and limb salvage rates were quite similar to those obtained with de novo surgery. PMID- 19875008 TI - Conservative treatment of spontaneous and isolated dissection of mesenteric arteries. AB - BACKGROUND: Isolated and spontaneous dissection of mesenteric arteries is a rare entity; a little more than 50 cases have been reported in medical literature. There is no therapeutic consensus concerning this type of lesion. METHODS: In this study, we report the results of our treatment based on a conservative approach. This retrospective study concerns eight patients with dissection of the celiac trunk and/or of the upper mesenteric artery (UMA) who were treated between 2002 and 2006. Because these patients were not presenting with acute intestinal ischemia diagnosed by clinical examination or paraclinical tests (medical imaging/biology) or with vital complications, they were treated with an efficient anticoagulation (heparin followed by anti-vitamin K) for 3 to 6 months. Endovascular or surgical treatment was used as the first option in patients with obvious intestinal ischemia or likely to have an arterial rupture, and also when medical treatment had failed. Clinical and radiological follow-up was at 1 month, 3 months, 6 months, and 1 year and then every year. Seven men and one woman (mean age, 48.2; age range, 38-53 years) were treated. Six patients presented with isolated dissection (celiac trunk=4, UMA=2). One patient had a celiac trunk and a UMA dissection and one had a celiac trunk and a UMA dissection along with a dissection of his two renal arteries. On entering the hospital, a patient was operated on for mesenteric ischemia related to a stenosis of the upper mesenteric artery (upper aortomesenteric bypass); a covered stent was implanted in the celiac trunk of another patient presenting with a contained rupture. RESULTS: Both patients were successfully treated. Six patients were medically treated. One of them required an aortohepatic bypass to treat an aneurysmal evolution of the celiac trunk revealed by a computed tomography scan obtained 1 month after the symptoms had begun. In one patient, the dissection remained stable on imaging. Four patients were cured, with a mean 20.1-month follow-up. CONCLUSION: Conservative treatment of spontaneous dissections of mesenteric arteries is possible when there are no complications, and it gives satisfactory results provided regular clinical and radiological checking is performed. PMID- 19875009 TI - Bypass flap reconstruction, a novel technique for distal revascularization: outcome of first 10 clinical cases. AB - Combined distal venous bypass grafting and free flap transfer can achieve successful treatment of soft tissue defects due to advanced leg ischemia. However, this combined approach is a complex technique involving multiple anastomoses on the same arterial axis with an increased risk of thrombosis. To reduce this risk, we have proposed a new bypass-flap (BF) reconstruction technique using an arterial graft and a free flap supplied by a collateral branch of the graft. The purpose of this report is to document the outcome in the first 10 patients treated using the BF reconstruction technique. From 2002 to 2004, a total of 10 patients with a mean age of 67 years (range 55-78) were treated using a BF. All patients presented critical ischemia with soft tissue defects resulting in exposure of tendons and muscles on the foot or ankle. Distal anastomosis was made between the distal branch of the BF and the pedal artery in five cases, the posterior tibial artery or plantar artery in four cases, and the peroneal artery in one case. In six cases proximal anastomosis was performed between the leg artery and arterial autograft. In the remaining four cases proximal anastomosis required extension of the bypass using a venous graft. The mean duration of hospitalization was 25 days. During the postoperative period, one patient died due to stercoral peritonitis and one patient required major amputation due to unrelenting sepsis. Bypass occlusion was not observed. Mean follow-up was 24 months (range 14-36). No patient was lost to follow-up and no patient died after the first 30 postoperative days. Follow-up examinations including clinical assessment and Doppler ultrasound imaging were performed at 3 months and every 6 months thereafter. Findings demonstrated bypass patency and healing of the covered defect in all cases. Outcome in this initial series demonstrates the clinical feasibility of the new BF reconstruction technique, which allows revascularization and coverage of tissue defects using a one-piece anatomic unit. PMID- 19875010 TI - Treatment of popliteal aneurysms by femoral artery transposition: long-term evaluation. AB - A multicentric retrospective study was carried out on 29 operations (28 patients) to evaluate the long-term results of the treatment of popliteal artery aneurysms by transposition of the superficial femoral artery (SFA). This treatment consisted in proximal and distal ligation and bypass grafting or endoaneurysmorrhaphy followed by reconstruction of the popliteal artery. This surgery was always performed when the homolateral SFA could be used. After surgery, every patient was prescribed a long-term antiplatelet treatment. Mean follow-up was 39.2+/-28 months. Actuarial primary patency was 100% at 1 year and 92% at 3 years. No patients presented with either aneurysmal evolution of arterial graft or septic complication of prosthetic bypass. SFA can be used to treat isolated popliteal aneurysms with satisfying long-term results. This technique is an alternative to the use of autologous saphenous vein. PMID- 19875011 TI - Extra-anatomical revascularization of the Adamkiewicz artery using the internal mammary artery: preliminary anatomical study. AB - Ischemic spinal cord injury remains a major complication of both open and endovascular repairs of extensive lesions of the thoracic or thoracoabdominal aorta. Patients undergoing endovascular treatment cannot benefit from direct revascularization of the Adamkiewicz artery (AA). Primary revascularization of the intercostal artery (ICA) giving rise to the AA using the internal mammary artery (IMA) could ensure uninterrupted flow in the AA even if the origin of the feeding ICA was obstructed. The purpose of this study was to assess the anatomical feasibility of revascularization of the ICA giving rise to the AA using the IMA. Twenty-four dissections were carried out on 12 cadavers (eight men, four women) with a mean age of 76 at the time of death. Preparation consisted of intra-arterial injection of polymethylsiloxane (Rhodorsil, Rhodia, France). For each IMA, the following parameters were determined: diameter in relation to the ICA in the paravertebral region before division, length, and level of the intercostal space in which direct anastomosis was possible. Dissection showed that the mean diameter at the end of the IMA was 1.8mm (range 1.2-2.4). The mean diameter of the ICA in the paravertebral region was compatible with that of the IMA, i.e., 1.6mm (range 0.9-2.5). The mean length of the IMA was 185 mm (range 165-230). The lowest intercostal space available in the paravertebral region for direct anastomosis between the IMA and ICA was the seventh space in one case, the eighth in 12, the ninth in eight, and the tenth in three. The findings of this preliminary study document the feasibility of using the IMA to revascularize the ICA in the paravertebral region. This technique could provide a means of preserving spinal cord vascularization during endovascular treatment of thoracic or thoracoabdominal aortic lesions. PMID- 19875012 TI - Fibrodysplastic popliteal aneurysm and dilatation of pedal artery. AB - We report a case of an asymptomatic popliteal aneurysm due to fibromuscular dysplasia (FMD), associated with suspected FMD of pedal artery on a 63-year-old woman. The popliteal aneurysm was resected. An in situ interposition of a short segment of hypogastric artery was performed to restore the arterial continuity. Popliteal FMD was confirmed by histological findings. Only 5 cases are reported in literature. FMD of pedal artery was suspected on the CT-scan aspect. FMD is a rare cause of popliteal aneurysm. To our knowledge, this is the first report of suspected fibrodysplastic dilatation of a foot artery. PMID- 19875013 TI - Severe acute pancreatitis after surgical treatment of a ruptured abdominal aortic aneurysm. AB - Acute pancreatitis (AP) is a rare complication of surgery for abdominal aortic aneurysms, which is often diagnosed late. It is secondary to ischemia and to peroperative pancreatic trauma. We report a case of severe AP after surgical treatment of a ruptured abdominal aorta aneurysm and discuss its etiopathogenic mechanisms. PMID- 19875014 TI - Management of carotid Dacron patch infection: a case report using median sternotomy for proximal common carotid artery control and in situ polytetrafluoroethylene grafting. AB - We report on a 58-year-old male who presented with an enlarging cervical hematoma 3 months following carotid endarterectomy with Dacron patch repair, due to septic disruption of the Dacron patch secondary to presumed infection. The essential features of this case are the control of the proximal common carotid artery gained through a median sternotomy, because the patient was markedly obese with minimal thyromental distance, and the treatment consisting of in situ polytetrafluoroethylene bypass grafting, due to the absence of a suitable autogenous saphenous vein. Median sternotomy is rarely required in case of reintervention for septic false aneurysms and hematomas following carotid endarterectomy but should be considered whenever difficult control of the common carotid artery, when entering the previous cervicotomy, is anticipated. In situ polytetrafluoroethylene grafting can be considered if autogenous vein material is lacking. PMID- 19875015 TI - Tuberculosis of the renal artery: a rare cause of renovascular arterial hypertension. AB - Tuberculosis is an endemic disease in Morocco. Main blood vessels are rarely affected; the few mentioned cases are aneurysmal. We report a 17-year-old patient presenting with renovascular arterial hypertension, revealed thanks to the discovery of an occlusion of the right renal artery in Duplex scan. During the intervention, the observation of pararenal and mesenteric tuberculous polyadenopathy let us suggest the same kind of lesion at the level of the occluded renal artery. Once antituberculosis treatment had been carried out, the right renal artery was revascularized with a right iliorenal bypass using reversed internal saphenous vein. The postoperative course was uneventful, with an 18-month follow-up. Arterial pressure was normal without antihypertensive treatment, and the bypass was patent. As far as we know, this is the first case of renovascular arterial hypertension resulting from tuberculosis treated with an iliorenal bypass. PMID- 19875016 TI - Mesenteric autotransplantation: an alternative technique for reoperation and bypass of the superior mesenteric artery. AB - Superior mesenteric artery (SMA) aneurysms represent a minority of visceral aneurysms but may result in lethal complications if left untreated. Options for treatment include aneurysmorraphy, bypass, ligation, or embolization. Here we present a case of a man with a history of celiac graft thrombosis who presents with a recurrent symptomatic SMA aneurysm. Given his compromised celiac axis, ligation was not an option. His SMA aneurysm was repaired with a PTFE patch. However, to secure longstanding blood flow to the small bowel in the event of graft thrombosis, the distal SMA pedicle was dissected free of the ileocolic vessels and anastomosed to the aorta. Follow-up studies demonstrated an occluded PTFE patch with a patent SMA autotransplant. This case depicts a novel approach to the surgical management of complex recurrent SMA aneurysms. PMID- 19875017 TI - Endograft infection presenting as a ruptured aortic aneurysm. AB - Aortic endograft procedures have become commonplace. Fortunately, infection of endografts remains rare, with an incidence <0.5%. Infection results from contamination at the time of implantation, by seeding the graft from a remote infection, or contiguous infection. We describe a case of late infection after endovascular aortic repair resulting in rupture of the aneurysm sac, followed by a brief review of endograft infections. In a review of the endograft literature, only one other article describes rupture of an aneurysm after endograft due to infection. This case highlights the importance of a thorough endograft evaluation in any patient with abdominal complaints. PMID- 19875018 TI - Insights into the management of venous outflow in patients with primary vascular sarcoma. PMID- 19875019 TI - On ten-year epidemiological review of in-hospital patients with Marfan syndrome. PMID- 19875020 TI - On the management of mycotic femoral pseudoaneurysms in intravenous drug abusers. PMID- 19875022 TI - An avid reading fan. PMID- 19875023 TI - Management of pediatric asthma: focus on the Expert Panel Report 3. PMID- 19875024 TI - Association between parental anxiety and compliance with preoperative requirements for pediatric outpatient surgery. AB - PURPOSE: The purpose of this study was to determine if parental anxiety interferes with the ability to follow preoperative requirements. METHOD: In a single center observational study of parents of children admitted to a same-day surgical unit at a tertiary pediatric hospital, parental preoperative anxiety was measured by the State-Trait Anxiety Inventory (STAI) questionnaire. Anxiety was correlated to a four points assessment of adherence with the following preoperative requirements: dietary restrictions, timely arrival at the hospital, arrival at the assigned room, and completion of required medical forms, because those requirements are the greatest external contributors to surgical cancellation according to hospital statistics. RESULTS: A total of 203 families completed the study. The average STAI score on the day of surgery was 38+/-12 (population average, 36+/-11). Only 130 families (66%) complied with all four preoperative requirements. A higher level of anxiety was significantly associated with lower probability of compliance (odds ratio, 0.88; 95% confidence interval, 0.78-1.00, P=05). In univariate models, factors associated with higher STAI scores included younger parent age, younger children, only child, child's first surgery, and no medical consultation between surgical assessment and surgery. DISCUSSION: Parental anxiety could be associated with a lower likelihood of parents following preoperative requirements and could contribute to increased likelihood of surgical cancellation. PMID- 19875025 TI - Risks for hypertension among undiagnosed African American mothers and daughters. AB - INTRODUCTION: This study examines risks for high blood pressure (BP) among undiagnosed African American mothers and daughters, because African American children are at risk for hypertension due to familial influences. METHOD: This study was cross-sectional in design and included 70 African American mother and daughter participants from the Detroit metropolitan area. RESULTS: BP readings clinically diagnostic of hypertension were found for mothers (25.7%) and daughters (54.3%), although they were undiagnosed. Many participants with BP readings in pre-hypertension or hypertension categories were overweight or obese (mothers, 90.9%; daughters, 50.2%). Fewer underweight or normal-weight mothers (25.0%) and daughters (64.3%) had BP readings indicative of hypertension. Lower diastolic BP was associated with higher body mass index (BMI) among mothers (r = .34, P = .045). Higher systolic BP was positively related to potassium consumption among daughters and total African Americans (r = .55, P = .005 and r = .41, P = .003, respectively). DISCUSSION: Early screening for hypertension is needed to improve health among African Americans. Health providers should use American Academy of Pediatrics guidelines for determining hypertension in children. Research on familial and environment influences on BP among children is recommended to determine early risk for the development of hypertension. PMID- 19875026 TI - Parental hesitation as a factor in delayed childhood immunization. AB - INTRODUCTION: One reason for lower immunization rates is that some parents hesitate to have their children immunized. A hesitancy questionnaire was developed to identify reasons parents hesitate in having their children immunized. METHODS: The hesitancy questionnaire was distributed from local pediatric and family practice offices and from the area's county health department. To be eligible, participants needed to be present in the clinic with a child needing a minimum of one immunization that was at least 6 months overdue. RESULTS: When questioned why their child was overdue for immunizations, the most common response was that participants were confused about the immunization schedule and not sure when to return. Of the participants who reported having concerns regarding immunizations, the child's pain/crying/anxiety was the most commonly occurring answer. When asked where they receive the majority of childhood immunization information, participants frequently identified their health care provider as the main source of information. DISCUSSION: Health care providers may be missing opportunities to educate hesitant parents about immunizations. Parents may not have ample opportunities to discuss their immunization concerns in detail with their health care provider during regularly scheduled clinic visits. It is important for health care providers to suggest ways parents can cope with their child's pain/crying/anxiety when receiving immunizations. PMID- 19875027 TI - Does assessing sleep inadequacy across its continuum inform associations with child and family health? AB - INTRODUCTION: The purpose of this study was to examine the prevalence and characteristics of children experiencing a continuum of inadequate sleep and its associations with child, family, and environmental variables. METHOD: A secondary analysis of weighted responses of 68,418 parents or caregivers of children aged 6 to 17 years participating in the 2003 National Survey of Children's Health was conducted. Inadequate sleep was categorized as mild, moderate, or severe. RESULTS: Approximately one third of parents reported their child's sleep inadequacy as mild (18.6%), moderate (6.8%), or severe (5.8%). Age (P < .001), fair/poor health status (P < .001), frequent depressive symptoms (P < .001), and high parental stress (P < .001) demonstrated a progressive relationship from adequate to severe inadequate sleep. Controlling for child, family, and environment variables, parents of children with inadequate sleep were more likely to report frequent child depressive symptoms, high parental stress, and violent family conflict style. DISCUSSION: Sleep inadequacy affects 15 million American children, 6 million at a moderate or severe level. Identification of inadequate sleep should prompt further assessment of its associated factors-depressive symptoms, parental stress, and family conflict-for targeted clinical intervention. PMID- 19875028 TI - Scurvy: forgotten but definitely not gone. AB - Scurvy, a disease of vitamin C deficiency, is purportedly rare in the United States yet frequently may be misdiagnosed. Presenting symptoms include bone pain, limping, rashes, or spongy bleeding gingiva. These symptoms mimic many other disorders, which often results in numerous unnecessary, invasive, and expensive procedural investigations. The strongest indication of a scurvy diagnosis is the dramatic response to the administration of vitamin C. This case report demonstrates the complexities involved in determining the cause of one child's symptoms. A thorough nutritional history and a shrewd clinician are essential to the early diagnosis and treatment of scurvy. PMID- 19875029 TI - Case study: infant with fishy odor syndrome. PMID- 19875030 TI - Chemical policy and the impact on child health. PMID- 19875031 TI - Focus on nonexperimental approaches. PMID- 19875032 TI - The effects of an advanced practice nurse led telephone intervention on outcomes of patients with heart failure. AB - This study sought to determine the effect of an advanced-practice-nurse (APN)-led telephone intervention on hospital readmissions, quality of life, and self-care behaviors (SCBs) of patients with heart failure (HF). Twenty participants were randomly assigned to either an experimental group that received the APN-led telephone intervention (ALTI) or a control group that received usual care in this pretest-posttest experimental study. The results of this study support the idea that an ALTI positively impacts outcomes of patient with HF, particularly by improving SCBs and decreasing hospital readmissions. An ALTI warrants consideration to improve outcomes of patients with HF. PMID- 19875033 TI - Empowerment, job satisfaction, and organizational commitment: comparison of permanent and temporary nurses in Korea. AB - AIM: This study was conducted to describe and compare empowerment, job satisfaction, and organizational commitment between permanent and temporary nurses in Korea. BACKGROUND: Since Korea's economic crisis of 1997, Korea's labor market has been undergoing dramatic modification, and the rate of temporary nurses employed in health care organizations has gradually increased. However, studies focusing on nurses' employment status, which potentially affect the individual and hospital organization, have been rarely conducted. METHODS: This was a descriptive comparative study. The convenient sample of 416 nurses from 19 hospitals in Korea completed a structured questionnaire. RESULTS: Overall, permanent nurses presented higher levels of job satisfaction, organizational commitment, and empowerment than did temporary nurses. CONCLUSIONS: The results of this study indicated that health care administrators should develop strategies to close the gap of perceptions between permanent and temporary nurses in Korea. The results of this study also imply that such opportunities and compensation plans related with administrative recognition should be made available to the temporary nurses to manage their workforces more efficiently. PMID- 19875035 TI - Clinical diaries and their research value. PMID- 19875034 TI - Weathering the storm: challenges to nurses providing care to nursing home residents during hurricanes. AB - This article documents the experience of 291 Florida nursing homes during the 2004 hurricane season. Using quantitative and qualitative methods, the authors described and compared the challenges nurses encountered when evacuating residents with their experiences assisting residents of facilities that sheltered in place. The primary concerns for evacuating facilities were accessing appropriate evacuation sites for residents and having ambulance transportation contracts honored. The main issue for facilities that sheltered in place was the length of time it took for power to be restored. Barriers to maintaining resident health during disasters for those who evacuated or sheltered in place are identified. PMID- 19875036 TI - An exploratory study of cardiac health in college athletes. AB - A common assumption is that college athletes are healthy based on their age and level of physical activity. This study used a descriptive correlational design to explore relationships and predictors of physical fitness levels among an ethnically diverse sample of 135 college athletes from a National College Athletic Association Division II university. Both subjective and objective indices of cardiac health and physical fitness level (blood pressure [BP], body mass index [BMI], waist-to-hip ratio, waist circumference, hip circumference, blood lipids, glucose, and VO(2max)) were collected. Minimal research exists with this population or with such an array of subjective and objective measures. More than one fourth of the athletes had a BMI in the overweight range, one fifth was prehypertensive, and one fourth had lower-than-recommended high-density lipoprotein (HDL) cholesterol levels. Waist circumference accounted for 21% of the variance in systolic BP level. These factors may predispose the college athletes to cardiac risk in the future when exercise regimens are reduced. Gender differences were found in all physical size variables and in physical fitness levels, with physical fitness level alone predicting gender correctly 98.5% of the time. Differences support the need to account for gender and fitness levels in cardiac risk assessment of young populations. PMID- 19875037 TI - "Holding our breath": the experiences of women contemplating nuchal translucency screening. AB - This article describes the experiences of women who were contemplating nuchal translucency (NT) screening for Down syndrome. Data were collected via semistructured interviews from 20 participants and subjected to a hermeneutic analysis. Findings included that pregnancy was considered to be an essentially abnormal process involving major risks and that being a "good mother" meant rejecting their own mother's advice and keeping quiet about a decision to terminate the pregnancy. Friends played an important role in influencing women to accept NT screening. PMID- 19875038 TI - Nurse consultation support to primary care practices to increase delivery of health behavior services. AB - Tobacco use, lack of physical activity, poor diet, and alcohol use are the key preventable causes of death in the United States. This study tested the use of nurses as consultants to primary care practices to assist practice clinicians and staff in identifying and carrying out plans to help their adult patients improve these health behaviors. A pre-post chart audit was conducted, and 17 of 20 practices (85%, p = <.01) increased documentation of health behavior delivery a mean absolute increase of 5.5% after the intervention. Nurse consultation may be an effective strategy to increase health behavior delivery to patients in primary care. PMID- 19875039 TI - A study on the subjective well-being and its influential factors in chronically ill inpatients in Changsha, China. AB - The aim of this paper is to assess the subjective well-being of chronically ill inpatients to know which its influential factors are, what the significant predictors of SWB are, and what we can do in nursing care. A sample of 290 inpatients with chronic respiratory diseases, diabetes, and cardiovascular diseases responded to questionnaires assessing well-being, anxiety, and depression and gave suggestions about nursing during an interview. It was shown that these patients' subjective well-being was lower than that of the general population. Using ANOVA, Pearson correlations, and multivariate stepwise regression analysis, trait anxiety, anxiety, and means of payment were found to significantly influence subjective well-being. Interventions targeting trait anxiety, anxiety, and means of payments, such as paying more attention to individuals' psychological symptoms, implementing more cost-effective treatment or caring, and establishing positive relationship with patients are necessary to improve inpatients' subjective well-being. PMID- 19875040 TI - The effects of job demands, control, and social support on hospital clinical nurses' intention to turn over. AB - Nursing turnovers may cause a serious setback to the quality of health delivery system. In addition, this turnover increases direct and indirect labor costs. This study examined the influence of job demand, job control, and social support on clinical nurses' turnover intention based on the job strain model. In total, 373 hospital clinical nurses in northern, central, and southern Taiwan were surveyed. The results show that nurses in high job demand and low-control work situations reveal the highest turnover intention. Job-related social support may decrease this turnover rate. PMID- 19875041 TI - Summative index: Acute pain management in older adults. AB - One of the challenges in measuring adoption of complex evidence-based practices (EBPs) such as acute pain management is determining what constitutes adherence to an EBP guideline. Traditionally, individual process indicators extrapolated from an EBP guideline are selected as dependent measures of guideline adoption. When using multiple indicators, the challenge is determining the number of indicators that must be met to define adherence to the EBP guideline. The primary goal of the study reported herein was to develop and test a summative index (SI) of guideline adherence for acute pain management of hospitalized older adults. Steps in formulating the initial index are described as well as refinement of this metric. Techniques used included factor analysis, discriminate validity, and split-half reliability. The resulting SI is composed of 18 indicators each scored as 0 (not present) or 1 (present), with a total SI score of 0 to 18. PMID- 19875042 TI - Feasibility and acceptability of stepping exercise for cardiovascular fitness in women. AB - Nurses conducting clinical research often test the feasibility and acceptability of interventions before using them in large-scale experimental studies. This article specifically reviews stepping exercise as an intervention with women. In a literature review, three stepping modes (steptreadmill, bench/step, and stepper) were compared, with the steptreadmill being identified as the most advantageous for use in experimental research. An exemplar was constructed to illustrate feasibility and acceptability of steptreadmill exercise (motorized stair climbing) in 11 women with hypertension. Steptreadmill exercise is feasible and acceptable and shows promise for use in experimental studies where strict control over the exercise performed is required. PMID- 19875043 TI - Synthesis and evaluation of a radioiodinated lumiracoxib derivative for the imaging of cyclooxygenase-2 expression. AB - INTRODUCTION: Despite extensive attempts to develop cyclooxygenase (COX)-2 imaging radiotracers, no suitable positron emission tomography (PET)/single photon emission computed tomography (SPECT) tracers are currently available for in vivo imaging of COX-2 expression. The aims of this study were to synthesize and evaluate a radioiodinated derivative of lumiracoxib, 2-[(2-fluoro-6 iodophenyl)-amino]-5-methylphenylacetic acid (FIMA), which is structurally distinct from other drugs in the class and has weakly acidic properties, as a SPECT tracer for imaging COX-2 expression. METHODS: The COX inhibitory potency was assessed by measuring COX-catalyzed oxidation with hydrogen peroxide. Cell uptake characteristics of (125)I-FIMA were assessed in control and linterfero/interferon-gamma-stimulated macrophages. The biodistribution of (125)I FIMA was determined by the ex vivo tissue counting method in rats. RESULTS: The COX-2 inhibitory potency of FIMA (IC(50)=2.46 microM) was higher than that of indomethacin (IC(50)=20.9 microM) and was comparable to lumiracoxib (IC(50)=0.77 microM) and diclofenac (IC(50)=0.98 microM). The IC(50) ratio (COX-1/COX-2=182) indicated FIMA has a high isoform selectivity for COX-2. (125)I-FIMA showed a significantly higher accumulation in COX-2 induced macrophages than in control macrophages, which decreased with nonradioactive FIMA in a concentration dependent manner. The biodistribution study showed rapid clearance of (125)I-FIMA from the blood and most organs including the liver and kidneys. No significant in vivo deiodination was observed with radioiodinated FIMA. CONCLUSIONS: FIMA showed high inhibitory potency and selectivity for COX-2. Radioiodinated FIMA showed specific accumulation into COX-2 induced macrophages, no significant in vivo deiodination and rapid blood clearance. Radioiodinated FIMA deserves further investigation as a SPECT radiopharmaceutical for imaging COX-2 expression. PMID- 19875044 TI - Validation of the calculation of the clearance rate constant (k(mono)) of [(11)C]acetate using parametric k(mono) image for myocardial oxidative metabolism. AB - INTRODUCTION: The purpose of this study was to validate the calculation of myocardial oxidative metabolism rate using a parametric clearance rate constant (k(mono)) image. METHODS: Fifteen subjects (seven volunteers, eight patients) were studied. Dynamic PET was acquired after intravenous injection of 700 MBq of [(11)C]acetate. The clearance rate constant of [(11)C]acetate (k(mono)) was calculated pixel by pixel to generate the parametric k(mono) image. The k(mono) values from this image and those calculated from the dynamic image were compared in the same regions of interest (ROIs). RESULTS: Two different methods showed an excellent correlation except in the very low range. Regression equations were y=0.99x+0.0034 (r(2)=0.86, P<.001) and y=1.16x-0.0077 (r(2)=0.87, P<.001) in normal volunteer and patient groups, respectively, and y=1.07x-0.0019 (r(2)=0.87, P<.001) when combined. CONCLUSIONS: Both methods exhibited similar values of k(mono). Parametric k(mono) image may result in better visual understanding of regional myocardial oxidative metabolism. PMID- 19875045 TI - Localization of radiolabeled anti-CEA antibody in subcutaneous and intrahepatic colorectal xenografts: influence of tumor size and location within host organ on antibody uptake. AB - INTRODUCTION: Radioimmunotherapy (RIT) has been shown to be more effective against solid tumor micrometastases, possibly due to an inverse relationship between tumor size and radiolabeled antibody uptake. In this study, the accretion of radiolabeled antibody in intrahepatic micrometastases in an experimental model was investigated using quantitative digital autoradiography, enabling the analysis of antibody uptake in microscopic tumors. METHODS: Mice bearing subcutaneous or intrahepatic metastatic models of LS174T colorectal cancer were injected with radiolabeled anti-carcinoembryonic antigen antibody ([(125)I]A5B7). Tissues were taken to investigate distribution of radionuclide and tumor uptake. In a therapy study, mice bearing intrahepatic metastatic tumors were injected with [(131)I]A5B7. RESULTS: Subcutaneous tumors and large metastatic deposits had similar uptake (e.g., approximately 15%ID/g at 24 h). Small metastatic deposits had higher uptake (e.g., approximately 80%ID/g at 24 h) and prolonged retention at later time points. Small deposit uptake was significantly reduced by accompanying large deposits in the same liver. RIT resulted in increased survival time (untreated mean survival of 21.6+/-12.9 vs. treated mean survival of 39.1+/ 30.8 days), but there was a large range of response within groups, presumably due to variation in pattern and extent of tumor as observed in the biodistribution study. Liver function tests and body weight did not change with tumor growth or therapy response, strongly supporting the use of in vivo imaging in metastatic tumor therapy studies. CONCLUSIONS: Radioimmunodetection and therapy might be greatly influenced by the size and distribution of intrahepatic tumor deposits. PMID- 19875046 TI - Design of silicon-based misonidazole analogues and (18)F-radiolabelling. AB - INTRODUCTION: Development of new (18)F-labeled tracers for positron emission tomography (PET) imaging is increasingly important. Herein, we described the synthesis of silicon analogues of [(18)F]fluoromisonidazole in order to develop new radiolabelled compounds for the detection of tumour hypoxic domain. Their stabilities and their in vivo biodistribution were evaluated. METHODS: (18)F labeled silicon-based misonidazole analogues were synthesized by alkylating 2 nitroimidazole with alkyloxy-(3-chloropropyl)dialkyl or diarylsilane. These intermediates were labeled with [(18)F]F(-) with a mixture of K(18)F and Kryptofix (K222) in acetonitrile as standard condition. PET imaging was performed using a dedicated small animal PET scanner. RESULTS: (18)F-labeled silicon-based misonidazole analogues were easily synthesized in three steps. The hydrolytic and radiolytic stability of these new fluorosilanes depend on the steric hindrance at the silicon center. Indeed, partial uptake of dimethylfluorosilane [(18)F]2a(1-(3 (Fluorodimethylsilyl)propyl)-2-nitro-1H-imidazole) in tumor hypoxic area was observed but defluorination also appeared. Moreover, PET studies indicated that, owing to its high lipophilicity, the most stable dinaphtylfluorosilane [(18)F]2d is retained mainly by the lungs. CONCLUSION: We have described an efficient and versatile approach for the synthesis of (18)F-labeled, silicon-based misonidazole analogues. PET imaging of one of these compounds revealed that hypoxia could be detected. Controlling the biodistribution of (18)F-labeled silicon-based misonidazole analogues will require additional studies. PMID- 19875047 TI - Evaluation of single amino acid chelate derivatives and regioselective radiolabelling of a cyclic peptide for the urokinase plasminogen activator receptor. AB - INTRODUCTION: The aim of this work was to investigate the relative radiolabelling kinetics and affinity of a series of ligands for the [(99m)Tc(CO)(3)](+) core, both in the absence and in the presence of competing donors. This information was used to select a suitable ligand for radiolabelling complex peptide-based targeting vectors in high yield under mild conditions. METHODS: A series of alpha N-Fmoc-protected lysine derivatives bearing two heterocyclic donor groups at the epsilon-amine (1a, 2-pyridyl; '1b, quinolyl; '1c, 6-methoxy-2-pyridyl; 1d, 2 thiazolyl; 1e, N-methylimidazolyl; '1f, 3-pyridyl) were synthesized and labelled with (99m)Tc. A resin-capture purification strategy for the separation of residual ligand from the radiolabelled product was also developed. The binding affinities of targeted peptides 4, 5a and 5b for uPAR were determined using flow cytometry. RESULTS: Variable temperature radiolabelling reactions using 1a-'1f and [(99m)Tc(CO)(3)](+) revealed optimal kinetics and good selectivity for compounds '1a and 1d; in the case of '1a, 1d, and 1e, the labelling can be conducted at ambient temperature. The utility of this class of ligands was further demonstrated by the radiolabelling of a cyclic peptide that is known to target the serine protease receptor uPAR; essentially quantitative incorporation of (99m)Tc occurred exclusively at the SAAC site, despite the presence of a His residue, and without disruption of the disulfide bond. CONCLUSION: A series of single amino acid chelate (SAAC) ligands have been evaluated for their ability to incorporate (99m)Tc into peptides. The lead agent to emerge from this work is the thiazole SAAC derivative 1d which has demonstrated the ability to regioselectively label the widest range of peptides. PMID- 19875048 TI - Targeting aldehyde dehydrogenase: a potential approach for cell labeling. AB - INTRODUCTION: To advance the science and clinical application of stem cell therapy, the availability of a highly sensitive, quantitative and translational method for tracking stem cells would be invaluable. Because hematopoetic stem cells express high levels of the cytosolic enzyme aldehyde dehydrogenase-1A1 (ALDH1), we sought to develop an agent that is specific to ALDH1 and thus to cells expressing the enzyme. Such an agent might be also helpful in identifying tumors that are resistant to cyclophosphomide chemotherapy because ALDH1 is known to be responsible for this resistance. METHODS: We developed schemes for the synthesis of two radioiodinated aldehdyes - N-formylmethyl-5-[*I]iodopyridine-3 carboxamide ([*I]FMIC) and 4-diethylamino-3-[*I]iodobenzaldehyde ([*I]DEIBA)-at no-carrier-added levels from their respective tin precursors. These agents were evaluated using pure ALDH1 and tumor cells that expressed the enzyme. RESULTS: The average radiochemical yields for the synthesis of [(125)I]FMIC and [(125)I]DEIBA were 70+/-5% and 47+/-14%, respectively. ALDH1 converted both compounds to respective acids suggesting their suitability as ALDH1 imaging agents. Although ability of ALDH1 within the cells to oxidize one of these substrates was shown, specific uptake in ALDH-expressing tumor cells could not be demonstrated. CONCLUSION: To pursue this approach for ALDH1 imaging, radiolabeled aldehydes need to be designed such that, in addition to being good substrates for ALDH1, the cognate products should be sufficiently polar so as to be retained within the cells. PMID- 19875049 TI - [(18)F]Fallypride dopamine D2 receptor studies using delayed microPET scans and a modified Logan plot. AB - [(18)F]Fallypride PET studies can be used to estimate the nondisplaceable binding potential (BP(ND)) in vivo of dopamine D2/D3 receptor-rich regions of the brain. These studies often take considerable time, up to >or=2 h, limiting the throughput. In this work, we investigated whether limited-duration scans performed subsequent to tracer administration yielded stable BP(ND) estimates. In particular, we applied a modified version of the Logan plot method on the last 60 min of 120-min data and compared the results to those from analysis of the full data set. METHODS: Fourteen male Sprague-Dawley rats were injected with [(18)F]fallypride intravenously while under isoflurane anesthesia, and dynamic data were acquired on the microPET Focus 220 scanner for 120 min. The distribution volume ratio (DVR=BP(ND)+1) was calculated from a Logan plot using 120 min of data and from a modified version using only the last 60 min. Three of these rats were imaged again on a second day to test the reproducibility. A two tissue compartment model also was used to fit the time-activity curves (TACs) of the 120-min scans to estimate the parameters K(1), k(2), k(on), k(4) and B(max). These parameters were then used to simulate similar TACs while changing k(on) to reflect changes in the dopaminergic system. The simulated TACs were used as a means for exploring the differences in DVR estimates between the last 60 min only and the full 120 min of simulated data. RESULTS: The average DVR from the full 120-min scans was 13.8+/-0.9, whereas the average DVR estimated from only the last 60 min of data (DVR') was 16.3+/-1.0. The DVR estimates showed good reproducibility in the three rats (mean DVR=13.8+/-1.5 on Day 1 and DVR=13.8+/ 0.9 on Day 2). The simulations showed that the relationship between DVR' and DVR estimates follows a semilinear form with varying k(on). CONCLUSION: Although the BP(ND) estimates are slightly overestimated in a delayed scan mode (i.e., no initial radiotracer uptake measurements) compared to a full scan, this overestimation depends primarily on k(3) (approximately k(on) x B(max)) and has been evaluated in this work for a wide range of k(on) values using simulated TACs. In particular, the sensitivity of DVR' to changes in k(on) is similar to that of DVR. This method of delayed scans eliminates the necessity of imaging during the initial uptake of the radiotracer and, thus, can be used to increase the throughput of studies. PMID- 19875050 TI - Evaluation of nigrostriatal damage and its change over weeks in a rat model of Parkinson's disease: small animal positron emission tomography studies with [(11)C]beta-CFT. AB - INTRODUCTION: The cardinal pathological feature of Parkinson's disease (PD) is progressive loss of dopaminergic neurons. Since dopamine transporter (DAT) is a protein located presynaptically on dopaminergic nerve terminals, radioligands that bind to these sites are promising radiopharmaceuticals for evaluation of the integrity of the dopamine system. This study using positron emission tomography (PET) tracers, [(11)C]-2beta-carbomethoxy-3beta-(4-fluorophenyl)-tropane ([(11)C]beta-CFT, radioligand for DAT), was aimed at evaluating the degree of nigrostriatal damage and its change over weeks in a rat model of PD. METHODS: The brains of these rats were unilaterally lesioned by mechanical transection of the nigrostriatal dopamine pathway at the medial forebrain bundle (MFB). Behavioral studies were carried out by apomorphine (APO) challenge prior to and 1, 2 and 4 weeks after MFB axotomy. Small animal PET scans were performed 2 days after the behavioral test. Immunohistochemistry was conducted 4 days after the last PET scan. RESULTS: Compared with the contralateral intact side, a progressively decreased [(11)C]beta-CFT binding was observed on the lesioned side which correlated inversely with the APO-induced rotations. Postmortem immunohistochemical studies confirmed the loss of both striatal dopamine fibers and nigral neurons on the lesioned side. CONCLUSION: These findings not only demonstrate that the neuronal degeneration in this model is relatively slow, but also suggest [(11)C]beta-CFT is a sensitive marker to monitor the degree of nigrostriatal damage and its change over weeks. This marker can be used prospectively to study the progression of the disease, thereby making detection of early phases of PD possible. PMID- 19875051 TI - Glucose utilization in the brain during acute seizure is a useful biomarker for the evaluation of anticonvulsants: effect of methyl ethyl ketone in lithium pilocarpine status epilepticus rats. AB - Enhancement of glucose utilization in the brain has been well known during acute seizure in various kinds of animal model of epilepsy. This enhancement of glucose utilization might be related to neural damage in these animal models. Recently, we found that methyl ethyl ketone (MEK) had both anticonvulsive and neuroprotective effects in lithium-pilocapine (Li-pilo) status epilepticus (SE) rat. In this article, we measured the uptake of [(14)C]2-deoxyglucose ([(14)C]DG) in the Li-pilo SE and Li-pilo SE with MEK rat brain in order to assess whether the glucose utilization was a useful biomarker for the detection of efficacy of anticonvulsive compounds. Significant increase of [(14)C]DG uptake (45 min after the injection) in the cerebral cortex, hippocampus, amygdala and thalamus during acute seizure induced by Li-pilo were observed. On the other hand, the initial uptake of [(14)C]DG (1 min after the injection) in the Li-pilo SE rats was not different from the control rats. Therefore, the enhancement of glucose metabolism during acute seizure was due to the facilitation of the rate of phosphorylation process of [(14)C]DG in the brain. Pretreatment with MEK (8 mmol/kg) completely abolished the enhancement of glucose utilization in the Li-pilo SE rats. The present results indicated that glucose utilization in the brain during acute seizure might be a useful biomarker for the evaluation of efficacy of anticonvulsive compounds. PMID- 19875052 TI - Use of pressure-hold test for sterilizing filter membrane integrity in radiopharmaceutical manufacturing. AB - The bubble point test is the de facto standard for postproduction filter membrane integrity test in the radiopharmaceutical community. However, the bubble point test depends on a subjective visual assessment of bubbling rate that can be obscured by significant diffusive gas flows below the manufacturer's prescribed bubble point. To provide a more objective means to assess filter membrane integrity, this study evaluates the pressure-hold test as an alternative to the bubble point test. In our application of the pressure-hold test, the nonsterile side of the sterilizing filter is pressurized to 85% of the predetermined bubble point with nitrogen, the filter system is closed off from the pressurizing gas and the pressure is monitored over a prescribed time interval. The drop in pressure, which has a known relationship with diffusive gas flow, is used as a quantitative measure of membrane integrity. Characterization of the gas flow vs. pressure relationship of each filter/solution combination provides an objective and quantitative means for defining a critical value of pressure drop over which the membrane is indicated to be nonintegral. The method is applied to sterilizing filter integrity testing associated with the commonly produced radiopharmaceuticals, [(18)F]FDG and [(11)C]PIB. The method is shown to be robust, practical and amenable to automation in radiopharmaceutical manufacturing environments (e.g., hot cells). PMID- 19875053 TI - A restricted access material for rapid analysis of [(11)C]-labeled radiopharmaceuticals and their metabolites in plasma. AB - INTRODUCTION: Analysis of the radioactive components in plasma taken during positron emission tomography (PET) measurements is often vital for the correct quantification of the PET data. The described high-performance liquid chromatography (HPLC) method has been developed to provide a fast, sensitive and robust method for the measurement of plasma samples from PET studies using [(11)C]-labeled radiopharmaceuticals. METHODS: Unadulterated plasma samples were analyzed directly, following a simple filtration, by the use of a small extraction column, containing a restricted access material, combined with a monolithic analysis column in a column-switching HPLC system. RESULTS: Up to 4 ml of plasma was analyzed by this method within 4.5-7 min in a fully automated process. Because of the rapid analysis, a large number of samples could be analyzed during a 90-min PET scan. The extraction column could be used for analysis of up to 500 ml of plasma before replacement was required. CONCLUSIONS: The described method is fast and robust and the large sample volumes allow for accurate determination of the radioactive components in plasma even at 90 min after injection of a [(11)C]-labeled radiopharmaceutical. PMID- 19875054 TI - Trypsinization severely perturbs radioiodide transport via membrane Na/I symporter proteolysis: implications for reporter gene imaging. AB - INTRODUCTION: Cell preparation procedures injurious to Na/I symporters (NIS) could deter their usefulness for reporter gene assays and in vivo cell imaging. In this study, we investigated the effects of cell collection by trypsinization on radioiodide transport and in vivo cell imaging results. METHODS: The influence of trypsinization procedures on (125)I transport was evaluated using Huh-7/NIS hepatoma cells. The effects of graded concentrations of trypsin and EDTA were assessed on Huh-7/NIS and A431/NIS lung cancer cells. Trypsin-induced NIS proteolysis was investigated by immunoblots of plasma membrane prepared from adenovirus-infected mouse liver tissue. (99m)Tc-O(4)(-) scintigraphy was performed in Balb/C nude mice at 1 and 4 h following administration of Huh-7/NIS cells collected with and without trypsin. RESULTS: (125)I Transport ability of Huh-7/NIS cells was severely impaired within minutes of standard trypsinization and further deteriorated up to 24 h after termination of treatment. This perturbation was caused by trypsin, which dose- and time-dependently induced substantial reductions of (125)I uptake in Huh-7/NIS and A431/NIS cells. Immunoblot analysis revealed significant dose- and time-dependent losses of membrane NIS protein by trypsin. NIS proteolysis was completely blocked by soybean trypsin inhibitor, and partial protection was offered by the substrates iodide and perchlorate. On (99m)Tc-O(4)(-) scintigraphy of mice, cells prepared by trypsinization were poorly visualized, whereas those collected with a nonenzymatic method showed significantly better uptake and contrast. CONCLUSION: Trypsinization leads to serious perturbations in iodide accumulating capacity through tryptic degradation of membrane NIS protein. Hence, NIS-based reporter assays and in vivo cell imaging studies may benefit from better-optimized cell cultivation and harvesting procedures. PMID- 19875055 TI - Direct detection and quantification of abasic sites for in vivo studies of DNA damage and repair. AB - Use of chemotherapeutic agents to induce cytotoxic DNA damage and programmed cell death is a key strategy in cancer treatments. However, the efficacy of DNA targeted agents such as temozolomide is often compromised by intrinsic cellular responses such as DNA base excision repair (BER). Previous studies have shown that BER pathway resulted in formation of abasic or apurinic/apyrimidinic (AP) sites, and blockage of AP sites led to a significant enhancement of drug sensitivity due to reduction of DNA base excision repair. Since a number of chemotherapeutic agents also induce formation of AP sites, monitoring of these sites as a clinical correlate of drug effect will provide a useful tool in the development of DNA-targeted chemotherapies aimed at blocking abasic sites from repair. Here we report an imaging technique based on positron emission tomography (PET) that allows for direct quantification of AP sites in vivo. For this purpose, positron-emitting carbon-11 has been incorporated into methoxyamine ([(11)C]MX) that binds covalently to AP sites with high specificity. The binding specificity of [(11)C]MX for AP sites was demonstrated by in vivo blocking experiments. Using [(11)C]MX as a radiotracer, animal PET studies have been conducted in melanoma and glioma xenografts for quantification of AP sites. Following induction of AP sites by temozolomide, both tumor models showed significant increase of [(11)C]MX uptake in tumor regions in terms of radioactivity concentration as a function of time, which correlates well with conventional aldehyde reactive probe (ARP)-based bioassays for AP sites. PMID- 19875056 TI - Intracellular reactions affecting 2-amino-4-([(11)C]methylthio)butyric acid ([(11)C]methionine) response to carbon ion radiotherapy in C10 glioma cells. AB - PURPOSE: The response of 2-amino-4-([(14)C]methylthio)butyric acid ([(14)C]Met) uptake and [(125)I]3-iodo-alpha-methyl-l-tyrosine ([(125)I]IMT) uptake to radiotherapy of C10 glioma cells was compared to elucidate the intracellular reactions that affect the response of 2-amino-4-([(11)C]methylthio)butyric acid ([(11)C]Met) uptake to radiotherapy. METHODS: After irradiation of cultured (3 Gy) or xenografted C10 glioma cells (25 Gy) using a carbon ion beam, the accumulation of [(14)C]Met and [(125)I]IMT in the tumors was investigated. The radiometabolites in xenografted tumors after radiotherapy were analyzed by size exclusion HPLC. RESULTS: [(14)C]Met provided earlier responses to the carbon ion beam irradiation than [(125)I]IMT in both cultured and xenografted tumors. While [(125)I]IMT remained intact in xenografted tumor before and after irradiation, the radioactivity derived from [(14)C]Met was observed both in high molecular fractions and intact fractions, and the former decreased after irradiation. CONCLUSION: The earlier response of [(11)C]Met uptake to tumor radiotherapy could be attributable to the decline in the intracellular energy-dependent reactions of tumors due to radiotherapy. PMID- 19875057 TI - Chasing clot: thrombophilic states and the interventionalist. AB - Thrombophilia is a critical factor in a majority of cases of idiopathic venous thromboembolism and may play a role in arterial thrombotic disease. The more frequently occurring genetic disorders impose a modest increased risk for thromboembolic events. Some of the less common ones are associated with much greater frequency of pathologic clot formation. Most thrombotic episodes occur with additive predisposing risks, namely multiple inherited disorders or concurrent acquired prothrombotic factors. Understanding these disorders is important for interventional radiologists, who frequently treat affected patients. This article reviews the disorders and prevalence of thrombophilia and provides guidelines for handling such cases. PMID- 19875058 TI - Endovascular retrieval of intracardiac inferior vena cava filters: a review of published techniques. AB - Endovascular retrieval of intracardiac or intrapulmonary inferior vena cava (IVC) filters provides a less-invasive alternative to surgery; however, only a few publications provide details describing this approach. The authors searched the medical literature and identified 42 endovascular attempts in 35 publications. There were 29 successful retrievals from the heart (n = 28) and pulmonary artery (n = 1), with only one reported fatality. Of the 13 failed attempts, there were three reported deaths. The authors of 19 reports provided details of their technique. The endovascular approach provides a reasonable alternative treatment to surgical removal of intracardiac or intrapulmonary IVC filters. PMID- 19875059 TI - Transient bacteremia after a percutaneous liver biopsy. PMID- 19875060 TI - Catheter-directed therapy for the treatment of massive pulmonary embolism: systematic review and meta-analysis of modern techniques. AB - PURPOSE: Systemic thrombolysis for the treatment of acute pulmonary embolism (PE) carries an estimated 20% risk of major hemorrhage, including a 3%-5% risk of hemorrhagic stroke. The authors used evidence-based methods to evaluate the safety and effectiveness of modern catheter-directed therapy (CDT) as an alternative treatment for massive PE. MATERIALS AND METHODS: The systematic review was initiated by electronic literature searches (MEDLINE, EMBASE) for studies published from January 1990 through September 2008. Inclusion criteria were applied to select patients with acute massive PE treated with modern CDT. Modern techniques were defined as the use of low-profile devices (< or =10 F), mechanical fragmentation and/or aspiration of emboli including rheolytic thrombectomy, and intraclot thrombolytic injection if a local drug was infused. Relevant non-English language articles were translated into English. Paired reviewers assessed study quality and abstracted data. Meta-analysis was performed by using random effects models to calculate pooled estimates for complications and clinical success rates across studies. Clinical success was defined as stabilization of hemodynamics, resolution of hypoxia, and survival to hospital discharge. RESULTS: Five hundred ninety-four patients from 35 studies (six prospective, 29 retrospective) met the criteria for inclusion. The pooled clinical success rate from CDT was 86.5% (95% confidence interval [CI]: 82.1%, 90.2%). Pooled risks of minor and major procedural complications were 7.9% (95% CI: 5.0%, 11.3%) and 2.4% (95% CI: 1.9%, 4.3%), respectively. Data on the use of systemic thrombolysis before CDT were available in 571 patients; 546 of those patients (95%) were treated with CDT as the first adjunct to heparin without previous intravenous thrombolysis. CONCLUSIONS: Modern CDT is a relatively safe and effective treatment for acute massive PE. At experienced centers, CDT should be considered as a first-line treatment for patients with massive PE. PMID- 19875061 TI - Short- and long-term retrievability of the Celect vena cava filter: results from a multi-institutional registry. AB - PURPOSE: To evaluate retrievability of the Celect vena cava filter over time and to assess the safety of the retrieval procedure in a prospective multicenter registry. MATERIALS AND METHODS: Between October 2005 and March 2008, Celect filters were placed in 95 patients (61 men; mean age, 51 years +/- 18.5) with a temporary need for an inferior vena cava (IVC) filter. All patients satisfied requirements for filter placement; the primary indications for placement were pulmonary embolism (PE) with a contraindication to or failure of anticoagulation (n = 40), high risk for further PE (n = 29), trauma (n = 23), or massive PE with residual deep vein thrombosis and risk for further PE (n = 3). Filter orientation, vena cava injury, and other device-related incidents were evaluated at implantation and retrieval. The degree of difficulty associated with retrieval was also assessed. RESULTS: Filter retrieval was attempted in 58 patients (mean indwell time of 179 days; median, 168.5 d; range, 5-466 d). Fifty-six filters (96.6%) were successfully retrieved. Unsuccessful retrieval attempts were attributed to filter tilt (n = 1) or excessive tissue growth with the hook embedded in the endothelium (n = 1). No adverse events were associated with the inability to retrieve these filters. A Kaplan-Meier product-limit survival estimate revealed that the probability of successful filter retrieval remained at 100% at 50 weeks and at more than 74% at 55 weeks after implantation. No adverse events were related to the retrieval procedures. CONCLUSIONS: Retrieval of the Celect filter was performed safely as long as 466 days after implantation. PMID- 19875062 TI - Technical success and safety of retrieval of the G2 filter in a prospective, multicenter study. AB - PURPOSE: To assess the technical success and safety for retrieval of the G2 filter. MATERIALS AND METHODS: The authors performed a prospective, multicenter study of 100 patients with temporary indication for caval interruption. Patients were enrolled consecutively between December 2005 and July 2006. There were 67 men and 33 women with a mean age of 52.1 years (range, 19-82 years). Indications for filter placement were trauma (n = 56), perioperative risk (n = 16), and medical indications (n = 28). Forty-two patients had venous thromboembolism at filter placement. Fifty-eight filters were placed prophylactically. RESULTS: Retrieval was attempted in 61 patients. Fifty-eight of the 61 filters (95%) were successfully retrieved after a mean dwell time of 140 days (range, 5-300 days). In all failed retrievals, the filter tip was against the caval wall. There was no difference in dwell times between successful and unsuccessful retrievals. Although there were no cases of cranial migration, caudal migrations were observed in 12% of cases (10 of 85 patients with a complete data set). Other device-related complications included filter fracture (1/85, 1.2%), filter tilt of more than 15 degrees (15/85, 18%), and leg penetration (16/61, 26%). The recurrent pulmonary embolism (PE) rate was 2%, with no PE in the 30-day period after filter retrieval. CONCLUSIONS: Retrieval of the Recovery G2 filter was safe and successful in most patients. Caudal migration was observed as an unexpected phenomenon. PMID- 19875064 TI - Hepatic vein tumor thrombus as a risk factor for excessive pulmonary deposition of microspheres during TheraSphere therapy for unresectable hepatocellular carcinoma. AB - PURPOSE: To evaluate the impact of identifiable hepatic vein tumor thrombus on the ability to safely deliver TheraSphere (yttrium 90-containing glass microspheres) for the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A retrospective review was performed of 87 patients (71 men, 16 women; mean age, 64.5 years; age range, 25-83 y) referred for TheraSphere therapy for HCC during a 2-year period between April 2005 and May 2007. Evaluation included contrast-enhanced computed tomography or magnetic resonance imaging, selective mesenteric angiography, and radionuclide perfusion scintigraphy to measure the arteriovenous shunting through the tumor. RESULTS: Of the 87 patients, 83 underwent angiography and perfusion scintigraphy; 53 were ultimately treated with 65 glass microsphere infusions. Twelve of 83 were identified as having tumor thrombus in a hepatic vein or extending into the inferior vena cava. The mean lung shunt for the patients with hepatic vein tumor thrombus was 30% (range, 11% 60%), compared with 8.2% (range, 3%-23%) for patients without identifiable tumor thrombus. Two of the 12 patients were treated with reduced doses of glass microspheres, and the remaining 10 were offered alternative therapies. CONCLUSIONS: The presence of hepatic vein tumor thrombus is a risk factor for an increased lung shunt that may prohibit delivery of a therapeutic dose of TheraSphere to hepatic tumor. PMID- 19875063 TI - Transvenous variceal embolization during or after living-donor liver transplantation to improve portal venous flow. AB - PURPOSE: Diversion of portal vein (PV) flow from the partial liver graft in living-donor liver transplantation (LDLT) can be life-threatening and warrant interruption of large collateral vessels. The purpose of this study is to evaluate the clinical efficacy of percutaneous or intraoperative transvenous embolization of portosystemic collateral vessels to improve PV inflow during or after LDLT. MATERIALS AND METHODS: From 2000 to 2007, 105 of 1,435 patients (7%) who had undergone LDLT underwent percutaneous (n = 17) or intraoperative (n = 88) venography to evaluate the status of PV inflow and portosystemic collateral vessels. Among these 105 patients, 19 underwent percutaneous (n = 6) or intraoperative (n = 13) transvenous embolization of portosystemic collateral vessels to improve PV inflow. This included 12 men and seven women with a mean age of 46.5 years. RESULTS: Successful embolization of the portosystemic collateral vessels with subsequently improved PV inflow was achieved in all 13 patients (100%) treated with the intraoperative approach and in four of six (67%) patients treated with the percutaneous approach. During follow-up (median, 8 months), Doppler ultrasonography showed adequate PV inflow in 17 of 19 patients, and follow-up computed tomography showed that collateral flow to the varices disappeared in 13 patients and decreased in four patients. One patient died of acute reactivated hepatitis 2 months after the procedure. Overall clinical success was achieved in 16 of the 19 study patients (84%). CONCLUSIONS: Transvenous embolization of varices may be an effective method to improve PV inflow in LDLT recipients. PMID- 19875065 TI - Chest port placement with use of the single-incision insertion technique. AB - PURPOSE: To evaluate the single-incision technique for the placement of subcutaneous chest ports. Advantages, technical success, and complications were assessed. MATERIALS AND METHODS: From March 2007 through May 2008, 161 consecutive chest ports were placed with a modified single-incision technique and sonographic and fluoroscopic guidance via the right internal jugular vein (IJV; n = 130), right external jugular vein (n = 1), right subclavian vein (n = 1), or left IJV (n = 28). The primary indication was for long-term chemotherapy; all patients had malignancy. RESULTS: All single-incision chest port insertions were technically successful. Ports were placed in patients 19 months to 93 years of age (mean, 56.3 y), with a mean follow-up of 203.6 device-days per patient and a total of 32,779 catheter access days. No procedure-related complications, pocket hematomas, venous thromboses, or pneumothoraces were observed. Minor delayed complications occurred in three patients. Premature catheter removal was required for two patients (1.2%; 0.006 per 100 catheter-days). One port was removed less than 30 days after implantation for infection of the pocket (0.61%; 0.003 per 100 catheter-days). Another catheter was removed because of patient dissatisfaction and unconfirmed concerns with arrhythmia (0.61%; 0.003 per 100 catheter-days). One minor superficial wound infection was successfully treated with oral antibiotics, with the port kept in place. CONCLUSIONS: Use of a single-incision technique for chest port implantation in adult and pediatric oncology patients is feasible. This may be the preferred method of subcutaneous port placement, as it has a very low complication rate and a high success rate. Prospective evaluation is needed to compare it versus the conventional two-incision technique. PMID- 19875066 TI - Radiofrequency ablation in breast tissue: experimental study for evaluation of radiofrequency effects in the bovine udder and review of the literature. AB - PURPOSE: To investigate the radiofrequency (RF) effects on the nonlactating and lactating ex vivo bovine udder as a model for normal breast tissue. MATERIALS AND METHODS: RF ablation in three lactating and three nonlactating ex vivo bovine udders (ie, six udders) was performed. The opening of the electrodes was 3 cm. The temperature was applied in 10 degrees C increasing steps between 60 degrees C and 100 degrees C and each temperature was maintained for 15 minutes. The experiment was repeated three times for each temperature step in the lactating and nonlactating udder. Resected specimens were assessed histologically. The maximum diameter of the ablation zone and maximum width of the transition zone with respect to the temperature applied were measured. RESULTS: In the nonlactating tissue, there was a correlation of the temperature and diameter of tissue damage. There was a narrow transition zone of 0.10 cm in all cases except at 100 degrees C, when it was 0.17 cm. In the lactating udder, no correlation was seen. The transition zone was not well visualized at temperatures less than 80 degrees C, ranging in overall size between 0.15 cm and 0.20 cm. CONCLUSIONS: The results of the study, with clear demarcation of the ablation zones and transition zones in the normal breast tissue, support the potential of breast thermal ablation as a viable treatment for further study. Lactating tissue does not seem ideal for thermal ablation. The discrepancy of the extent of ablation and the length of the electrodes is an important finding in this study. Further in vivo studies in normal glandular tissue and tumor are necessary. PMID- 19875068 TI - Direct erosion and prolapse of esophageal stents into the tracheobronchial tree leading to life-threatening airway compromise. AB - Covered or uncovered self-expanding metal stents are currently used for the palliative treatment of neoplastic esophageal obstructions or compressions and malignant esophageal leaks or fistulas. This small series, from three different European hospitals, highlights the unusual but significant complication of esophageal stent perforation followed by erosion and prolapse of the endoprosthesis into the tracheobronchial tree causing acute airway compromise or aspiration. Possible causal mechanisms and means of treatment are discussed to raise physician awareness of this life-threatening complication. PMID- 19875067 TI - Radiofrequency ablation of metastatic pheochromocytoma. AB - In the present report on the preliminary safety and effectiveness of radiofrequency (RF) ablation for pheochromocytoma metastases, seven metastases were treated in six patients (mean size, 3.4 cm; range, 2.2-6 cm). alpha- and beta-adrenergic and catecholamine synthesis inhibition and intraprocedural anesthesia monitoring were used. Safety was assessed by recording ablation related complications. Complete ablation was defined as a lack of enhancement within the ablation zone on follow-up computed tomography. No serious adverse sequelae were observed. Complete ablation was achieved in six of seven metastases (mean follow-up, 12.3 months; range, 2.5-28 months). In conclusion, RF ablation may be safely performed for metastatic pheochromocytoma given careful attention to peri-procedural management. PMID- 19875069 TI - Re: Effectiveness of coil embolization in angiographically detectable versus non detectable sources of upper gastrointestinal hemorrhage. PMID- 19875071 TI - Endovascular repair of a distal aortic arch pseudoaneurysm with use of a scallop edged stent-graft. PMID- 19875073 TI - Hitting a nerve: ion channels may hold the key for treating chronic pain. PMID- 19875074 TI - Chasing after antibiotic leads. AB - The emergence of drug-resistant pathogens has prompted the search for new antibacterials. In this issue of Chemistry & Biology, Starosta et al. identify specific thiopeptide-antibiotic precursor lead compounds using three complementary high-throughput translation machinery assays. PMID- 19875075 TI - Expanding the repertoire of glycosynthases. AB - As reported in this issue, Moracci and coworkers have now expanded the glycosynthase concept to two retaining alpha-L-fucosidases. The newly generated alpha-fucosynthases can use beta-L-fucosyl azide as donors for transglycosylation, enabling the synthesis of fucose-containing oligosaccharides. PMID- 19875076 TI - Tools to tackle protein acetylation. AB - In the recent issue of Molecular Cell, Neumann et al. dissect the effect of H3K56 acetylation on chromatin structure using a novel method for generation of acetylated proteins. This is a valuable addition to the toolkit for those interested in unraveling how posttranslational modifications regulate protein function. PMID- 19875077 TI - Deciphering biosynthesis of the RNA polymerase inhibitor streptolydigin and generation of glycosylated derivatives. AB - The biosynthetic gene cluster for the dienoyltetramic acid streptolydigin was identified and characterized from the producer organism Streptomyces lydicus NRRL2433. Sequence analysis of an 80.8 kb DNA region revealed the presence of 38 ORFs, 29 of which are probably involved in streptolydigin biosynthesis and would code for all activities required for its biosynthesis. Six insertional inactivation mutants were generated in the sequenced region to prove its involvement in streptolydigin biosynthesis, to define the boundaries of the cluster, to functionally characterize some genes, and to generate novel derivatives. A model for streptolydigin biosynthesis is proposed that includes a probable domain skipping in the streptolydigin PKS and the participation of a free-standing adenylation domain protein. Some bioactive derivatives of streptolydigin with altered glycosylation pattern have been produced by combinatorial biosynthesis showing a certain degree of flexibility of the L rhodinosyl transferase SlgG for the recognition of 2,3,6-trideoxyhexoses and 2,6 dideoxyhexoses, both in D- and L-configuration. PMID- 19875078 TI - Discovery of potent and reversible monoacylglycerol lipase inhibitors. AB - Monoacylglycerol lipase (MGL) is a serine hydrolase involved in the biological deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). Previous efforts to design MGL inhibitors have focused on chemical scaffolds that irreversibly block the activity of this enzyme. Here, we describe two naturally occurring terpenoids, pristimerin and euphol, which inhibit MGL activity with high potency (median effective concentration, IC(50) = 93 nM and 315 nM, respectively) through a reversible mechanism. Mutational and modeling studies suggest that the two agents occupy a common hydrophobic pocket located within the putative lid domain of MGL, and each reversibly interacts with one of two adjacent cysteine residues (Cys(201) and Cys(208)) flanking such pocket. This previously unrecognized regulatory region might offer a molecular target for potent and reversible inhibitors of MGL. PMID- 19875080 TI - Directed evolution and structural characterization of a simvastatin synthase. AB - Enzymes from natural product biosynthetic pathways are attractive candidates for creating tailored biocatalysts to produce semisynthetic pharmaceutical compounds. LovD is an acyltransferase that converts the inactive monacolin J acid (MJA) into the cholesterol-lowering lovastatin. LovD can also synthesize the blockbuster drug simvastatin using MJA and a synthetic alpha-dimethylbutyryl thioester, albeit with suboptimal properties as a biocatalyst. Here we used directed evolution to improve the properties of LovD toward semisynthesis of simvastatin. Mutants with improved catalytic efficiency, solubility, and thermal stability were obtained, with the best mutant displaying an approximately 11-fold increase in an Escherichia coli-based biocatalytic platform. To understand the structural basis of LovD enzymology, seven X-ray crystal structures were determined, including the parent LovD, an improved mutant G5, and G5 cocrystallized with ligands. Comparisons between the structures reveal that beneficial mutations stabilize the structure of G5 in a more compact conformation that is favorable for catalysis. PMID- 19875079 TI - Hemoglobin digestion in blood-feeding ticks: mapping a multipeptidase pathway by functional proteomics. AB - Hemoglobin digestion is an essential process for blood-feeding parasites. Using chemical tools, we deconvoluted the intracellular hemoglobinolytic cascade in the tick Ixodes ricinus, a vector of Lyme disease and tick-borne encephalitis. In tick gut tissue, a network of peptidases was demonstrated through imaging with specific activity-based probes and activity profiling with peptidic substrates and inhibitors. This peptidase network is induced upon blood feeding and degrades hemoglobin at acidic pH. Selective inhibitors were applied to dissect the roles of the individual peptidases and to determine the peptidase-specific cleavage map of the hemoglobin molecule. The degradation pathway is initiated by endopeptidases of aspartic and cysteine class (cathepsin D supported by cathepsin L and legumain) and is continued by cysteine amino- and carboxy-dipeptidases (cathepsins C and B). The identified enzymes are potential targets to developing novel anti-tick vaccines. PMID- 19875081 TI - Discovery of TNF inhibitors from a DNA-encoded chemical library based on diels alder cycloaddition. AB - DNA-encoded chemical libraries are promising tools for the discovery of ligands toward protein targets of pharmaceutical relevance. DNA-encoded small molecules can be enriched in affinity-based selections and their unique DNA "barcode" allows the amplification and identification by high-throughput sequencing. We describe selection experiments using a DNA-encoded 4000-compound library generated by Diels-Alder cycloadditions. High-throughput sequencing enabled the identification and relative quantification of library members before and after selection. Sequence enrichment profiles corresponding to the "bar-coded" library members were validated by affinity measurements of single compounds. We were able to affinity mature trypsin inhibitors and identify a series of albumin binders for the conjugation of pharmaceuticals. Furthermore, we discovered a ligand for the antiapoptotic Bcl-xL protein and a class of tumor necrosis factor (TNF) binders that completely inhibited TNF-mediated killing of L-M fibroblasts in vitro. PMID- 19875083 TI - beta-Glycosyl azides as substrates for alpha-glycosynthases: preparation of efficient alpha-L-fucosynthases. AB - Fucose-containing oligosaccharides play a central role in physio-pathological events, and fucosylated oligosaccharides have interesting potential applications in biomedicine. No methods for the large-scale production of oligosaccharides are currently available, but the chemo-enzymatic approach is very promising. Glycosynthases, mutated glycosidases that synthesize oligosaccharides in high yields, have been demonstrated to be an interesting alternative. However, examples of glycosynthases available so far are restricted to a limited number of glycosidases families and to only one retaining alpha-glycosynthase. We show here that new mutants of two alpha-L-fucosidases are efficient alpha-L-fucosynthases. The approach shown utilized beta-L-fucopyranosyl azide as donor substrate leading to transglycosylation yields up to 91%. This is the first method exploiting a beta-glycosyl azide donor for alpha-glycosynthases; its applicability to the glycosynthetic methodology in a wider perspective is presented. PMID- 19875082 TI - Identification of distinct thiopeptide-antibiotic precursor lead compounds using translation machinery assays. AB - Most thiopeptide antibiotics target the translational machinery: thiostrepton (ThS) and nosiheptide (NoS) target the ribosome and inhibit translation factor function, whereas GE2270A/T binds to the elongation factor EF-Tu and prevents ternary complex formation. We have used several in vitro translational machinery assays to screen a library of thiopeptide antibiotic precursor compounds and identified four families of precursor compounds that are either themselves inhibitory or are able to relieve the inhibitory effects of ThS, NoS, or GE2270T. Some of these precursors represent distinct compounds with respect to their ability to bind to ribosomes. The results not only provide insight into the mechanism of action of thiopeptide compounds but also demonstrate the potential of such assays for identifying lead compounds that might be missed using conventional inhibitory screening protocols. PMID- 19875084 TI - Biosynthesis of macrolactam BE-14106 involves two distinct PKS systems and amino acid processing enzymes for generation of the aminoacyl starter unit. AB - BE-14106 is a macrocyclic lactam with an acyl side chain previously identified in a marine-derived Streptomyces sp. The gene cluster for BE-14106 biosynthesis was cloned from a Streptomyces strain newly isolated from marine sediments collected in the Trondheimsfjord (Norway). Bioinformatics and experimental analyses of the genes in the cluster suggested an unusual mechanism for assembly of the molecule. Biosynthesis of the aminoacyl starter apparently involves the concerted action of a distinct polyketide synthase (PKS) system and several enzymes that activate and process an amino acid. The resulting starter unit is loaded onto a second PKS complex, which completes the synthesis of the macrolactam ring. Gene inactivation experiments, enzyme assays with heterologously expressed proteins, and feeding studies supported the proposed model for the biosynthesis and provided new insights into the assembly of macrolactams with acyl side chain. PMID- 19875085 TI - Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome: it's more than the anatomy. PMID- 19875086 TI - The homeless teen mom. PMID- 19875087 TI - Pegaptanib sodium for macular edema secondary to branch retinal vein occlusion. AB - PURPOSE: To assess the efficacy and safety of intravitreous pegaptanib sodium (Macugen; EyeTech Pharmaceuticals/Pfizer Inc, New York, New York, USA) for macular edema secondary to branch retinal vein occlusion (BRVO). DESIGN: Prospective, randomized, dose-finding study. METHODS: Twenty subjects from three clinical practices in the United States with BRVO of more than 1 month's and fewer than 6 months' duration; best-corrected visual acuity (BCVA) 70 to 25 Early Treatment Diabetic Retinopathy Study letters inclusive (approximately 20/40 to 20/320 Snellen); and central foveal thickness of 250 microm or more were included. Subjects were randomized 3:1 to intravitreous injections of pegaptanib 0.3 or 1 mg at baseline and at weeks 6 and 12 with subsequent injections at 6 week intervals at investigator discretion until week 48. Principal efficacy outcomes were change from baseline to week 54 in BCVA, center point thickness, central subfield thickness, and macular volume as measured by optical coherence tomography. RESULTS: Fifteen subjects received pegaptanib 0.3 mg and 5 received pegaptanib 1 mg. Eighteen subjects completed the 54-week follow-up. Results were similar in both the 0.3- and 1-mg groups. Overall improvements from baseline to week 54 occurred in mean BCVA (+14 +/- 13 letters), center point thickness (-205 +/- 195 mum), central subfield thickness (-201 +/- 153 mum), and macular volume ( 2.2 +/- 1.6 mm(3)). The response was rapid after the first injection, with a mean BCVA improvement of 11 +/- 7 letters at 1 week from the baseline of 56 +/- 12 letters (approximately 20/80 Snellen). One retinal detachment and no cases of endophthalmitis or traumatic cataract were seen. CONCLUSIONS: Intravitreous pegaptanib offers a promising alternative as a treatment for macular edema secondary to BRVO. PMID- 19875088 TI - Incidence and factors related to macular hole reopening. AB - PURPOSE: To determine the incidence and the factors that can cause a reopening of a macular hole (MH) after a surgical closure. DESIGN: Retrospective, comparative, consecutive case series. METHODS: The medical charts of all patients who underwent vitrectomy with or without internal limiting membrane (ILM) peeling for an idiopathic full-thickness MH were reviewed. In all cases, the MH was closed successfully. Simultaneous phacoemulsification with intraocular lens implantation was performed on all phakic patients who were older than 40 years. RESULTS: Eight hundred and seventy-seven eyes of 831 patients with a mean age of 64.9 +/- 8.0 years were studied. Combined cataract extraction with vitrectomy was performed on 763 eyes of 775 phakic eyes. The mean follow-up time after MH surgery was 57.7 +/ 38.4 months (range, 1 to 175 months). Two groups were studied: an ILM-off group (n = 514) and an ILM-on group (n = 363). The MH reopened in 2 eyes (0.39%) in the ILM-off group and in 26 eyes (7.2%) in ILM-on group (P < .0001). Kaplan-Meier analysis showed higher rates of reopening in the ILM-on group than in the ILM-off group (P< .0001, log-rank test). Factors related to the reopening in the ILM-on group were refractive error (r = -0.12; P = .049) and intraoperative peripheral tear formation (r = 0.13; P = .018). CONCLUSIONS: ILM peeling significantly decreases the incidence of the reopening of an MH. Although the pathogenesis of the reopening of MHs is still undetermined, myopia and intraoperative retinal tears may be related to the reopening. PMID- 19875089 TI - Treatment with voriconazole in 3 eyes with resistant Acanthamoeba keratitis. AB - PURPOSE: To report the use of topical voriconazole 1% (Vfend; Pfizer Inc, New York, New York, USA) ophthalmic solution for Acanthamoeba keratitis (AK) resistant to treatment with chlorhexidine (PerioChip; Dexel Pharma Technologies, Jerusalem, Israel). DESIGN: Retrospective case series. METHODS: Three eyes of 2 patients with culture-proven AK were treated at a tertiary care institution, and their charts were reviewed. Topical voriconazole 1% was instituted as second-line treatment for AK unresponsive to standard treatment with chlorhexidine and hexamidine. Treatment with voriconazole 1% was started at 1-hour intervals. Improvement was assessed and defined by absence of clinical signs of active infection and visual improvement. RESULTS: One patient with unilateral AK and 1 patient with bilateral AK who remained culture-positive for Acanthamoeba despite ongoing treatment with chlorhexidine and hexamidine were treated with voriconazole 1% topical solution as an adjuvant. Both patients were contact lens wearers. Of 3 eyes additionally treated with voriconazole, 2 eyes had clinical resolution of disease. One eye demonstrated recurrent disease after penetrating keratoplasty that resolved after intrastromal injection of voriconazole. CONCLUSIONS: We report the use of topical and intrastromal voriconazole in successfully treating AK in cases of chlorhexidine- and hexamidine-resistant Acanthamoeba. Voriconazole may be a promising adjuvant agent in treating AK. PMID- 19875090 TI - The vitreous gel: more than meets the eye. AB - PURPOSE: To reexamine the role of the vitreous gel in ocular health and disease based on recent information in the ophthalmic literature. DESIGN: Perspective. METHODS: Review, analysis, and discussion of the implications of selected pertinent literature. RESULTS: A new understanding of the vitreous gel is emerging, placing it central to many disease processes affecting the eye, including diabetic retinopathy, retinal vein occlusion, age-related macular degeneration, nuclear sclerotic cataract, and primary open-angle glaucoma. The vitreous gel recently has been found to have the important function of oxygen regulation and distribution within the eye. As the gel undergoes age-related liquefaction or surgical removal this function is impaired. The resultant elevated intraocular oxygen tension likely proves beneficial for vascular endothelial growth factor-mediated retinal diseases. However, it may lead to oxidative stress within the eye and may contribute to disease states such as nuclear cataract and primary open-angle glaucoma. CONCLUSIONS: An intact gel vitreous is central to a healthy human eye. We now understand that age-related liquefaction of the vitreous gel accompanies several age-related ocular diseases. The field of ophthalmology would benefit from future research to understand age related vitreous liquefaction and to identify its cause. PMID- 19875091 TI - Subthreshold micropulse diode laser photocoagulation for diabetic macular edema in Japanese patients. AB - PURPOSE: To assess the efficacy and safety of subthreshold micropulse diode laser photocoagulation for diabetic macular edema (ME). DESIGN: Prospective, nonrandomized interventional case series. METHODS: SETTING: Institutional. PATIENTS: Thirty-six consecutive diabetic patients (43 eyes) with clinically significant ME and a central macular thickness (CMT) <600 microm by optical coherence tomography. OBSERVATION PROCEDURES: Subthreshold micropulse diode laser photocoagulation was done with a 15% duty cycle (0.2 to 0.3 sec; 200 microm) at 50% to 90% of the burn threshold energy. The treated area was monitored on color images for 12 months. MAIN OUTCOME MEASURES: CMT, best-corrected visual acuity (BCVA), and total macular volume at 3 months. RESULTS: After 3 months, there was a significant reduction of CMT (P = .05, paired t test), but the changes of BCVA and macular volume were not significant. The preoperative CMT, BCVA (logarithm of the minimal angle of resolution; logMAR), and macular volume were 341.8 +/- 119.0 microm, 0.12 +/- 0.20, and 8.763 +/- 1.605 mm(3) respectively, vs 300.7 +/- 124.1 microm, 0.12 +/- 0.21, and 8.636 +/- 1.408 mm(3) at 3 months. CMT decreased significantly from 1 month (P = .015, Friedman test). Visual acuity was improved or maintained within 0.2 logMAR for 12 months in 94.7% of the patients. No obvious laser scars were detected in any patient. CONCLUSIONS: In patients with moderate diabetic ME, subthreshold micropulse diode laser photocoagulation controls ME and maintains visual acuity with minimal retinal damage. These findings confirm the efficacy of this method for Japanese patients. PMID- 19875092 TI - Ocular surface reconstruction with autologous nasal mucosa in cicatricial ocular surface disease. AB - PURPOSE: To investigate the possibility of replacing the metaplastic ocular surface with nasal mucosa, and to evaluate the results of autologous nasal and oral mucosal transplantation in cicatricial ocular surface diseases. DESIGN: Retrospective interventional case series. METHODS: We studied 6 eyes in 6 patients with chemical burns, which were characterized by a cicatricial ocular surface. After removal of cicatricial tissues and symblepharolysis, autologous nasal mucosa was transplanted in all patients. In 3 patients with extensive damage, oral mucosal autografting was performed concurrently. The nasal and oral mucosa was evaluated using immunohistochemical analysis for p63, K3, MUC5AC, and CD34. Clinical outcomes were assessed based on visual acuity, ocular manifestations, and liquid-based cytology. RESULTS: Immunohistochemical analysis revealed a plentitude of p63 and K3 in nasal mucosal epithelium. Goblet cells and MUC5AC expression were only observed in nasal mucosal epithelium, not in oral mucosal epithelium. Well-developed parallel vasculature was demonstrated in the nasal mucosa. In contrast, perpendicular vasculature was demonstrated in the oral mucosa. This vascular feature remained after transplantations. In all patients, ocular surface stability recovered with no major complications and increased goblet cells were observed on ocular surface. However, delayed epithelialization and ischemic thinning were seen at oral mucosal graft sites. CONCLUSIONS: Nasal mucosa, which has the advantage of well-developed parallel vasculature, enriched goblet cells, and plenty of stem cells, may be an ideal substitute for a cicatricial ocular surface. Transplantation of autologous nasal mucosa is a very effective method for achieving ocular surface reconstruction in cicatricial ocular surface diseases. PMID- 19875093 TI - Evaluation of sub-Tenon triamcinolone acetonide injections in the treatment of scleritis. AB - PURPOSE: To suggest that sub-Tenon triamcinolone acetonide (TA) injections may be a helpful supplement in patients with scleritis. DESIGN: Retrospective, interventional case series. METHODS: A retrospective chart review was conducted of all patients at our institution receiving sub-Tenon TA injections for scleritis between August 2001 and August 2007. Outcome measures included subjective improvement, presence of inflammation, and adverse events. RESULTS: Eleven patients (12 eyes) were included in this study. The mean age was 50 years; 2 patients were male and 9 female. Six patients had systemic autoimmune disease. All patients were receiving systemic medications for scleritis at the time of injection. Mean initial follow-up time was 3 weeks. Ten of 11 patients reported subjective improvement, and 10 patients had improvement in objective inflammation. Three patients had adverse side effects, including ocular hypertension, worsening of cataract, and subconjunctival hemorrhage with periorbital ecchymosis. CONCLUSIONS: Sub-Tenon TA injections may be a useful adjunct to achieving transient, partial improvement of subjective pain and objective inflammation in patients with scleritis while awaiting systemic medications to take effect. Adverse events were manageable in this small series. PMID- 19875094 TI - Intratarsal keratinous cysts of the Meibomian gland: distinctive clinicopathologic and immunohistochemical features in 6 cases. AB - PURPOSE: To describe 6 patients representing a new entity of Meibomian gland keratinous cysts. DESIGN: Retrospective, interventional, clinicopathologic study. METHODS: Review of clinical histories and findings, histopathologic evaluations, and immunohistochemical studies of the cysts' linings with monoclonal antibodies directed against cytokeratins and cell surface epithelial markers. RESULTS: Six patients with an average age of 62.5 years had noninflamed, upper eyelid nodules fixed to the tarsus. Eyelid eversion revealed a white-yellow nodular bulge in 3 cases, a bluish coloration in 2 cases, and a translucent appearance in 1 case. The cysts were lined by undulating squamous epithelium possessing an inner eosinophilic cuticle that produced a peculiar refractile, strand-like intracavitary keratin. Immunostaining for cytokeratin 17 and carcinoembryonic antigen showed strongly positive results in the Meibomian gland cysts and, by comparison, negative results in cutaneous epidermal cysts. Multiple recurrences occurred after incomplete excisions. CONCLUSIONS: After chalazia and sebaceous cell tumors, Meibomian gland keratinous cysts seem to be the third most common primary intratarsal lesion. Anterior fixation to the tarsus and posterior protrusion beneath the palpebral conjunctiva without inflammation suggest the diagnosis. Histopathologic and immunohistochemical evaluations can distinguish unequivocally the current entity from common epidermal cysts. The optimal treatment consists of an en bloc excision of the cyst with a tarsectomy, or else wide excision with intratarsal cautery of any remnants of the cellular lining. PMID- 19875095 TI - A rare form of midventricular Tako Tsubo cardiomyopathy. AB - We report a case of a rare form of midventricular Tako Tsubo cardiomyopathy characterized by left ventricular angiography and cardiac MRI. PMID- 19875096 TI - [Case report and review of a voluminous right atrial myxoma revealed by heart failure]. AB - Right atrial myxoma is a rare disease and its clinical presentation is not specific. The usual mode of revelation is heart failure. The most frequent complications are pulmonary embolism and atrioventricular valve obstruction by the tumor. A 49-year-old woman was admitted to intensive care unit for heart failure. The echocardiogram showed a voluminous right atrial myxoma, appending to the interatrial septum. Its surgical excision under extracorporeal circulation was successfully performed. Histology confirmed the final diagnosis of myxoma. No complication was observed at 6 months follow-up. PMID- 19875097 TI - [Radial access and management of patients with long-term oral anticoagulation for cardiac catheterization]. AB - Patients with long-term oral anticoagulation are exposed to high bleeding risk and should be managed with care for invasive procedure. Angioplasty is assumed to increase bleeding and access site complications and it is often recommended to temporarily interrupt anticoagulation therapy. Moreover, due to the lack of recommendations, antithrombotic regimen adopted after stenting represents a substantial challenge for the physician who must balance the risk of ischemic and bleeding events. Nevertheless, approaches as uninterrupted therapeutic oral anticoagulation, transradial approach and a best knowledge of ischemic risk, haemorrhage risk and restenosis risk can limit long term complication. Herein, we review the currently available data assessing angioplasty and long-term antithrombotic therapy for stented patients with long-term oral anticoagulation and we propose a potential treatment paradigm to improve long-term prognosis. PMID- 19875098 TI - [How to manage acquired stenosis of the external auditory canal]. PMID- 19875099 TI - Utility of the RT3 triaxial accelerometer in free living: an investigation of adherence and data loss. AB - There is strong evidence for the protective effects of physical activity on chronic health problems. Activity monitors can objectively measure free living occupational and leisure time physical activity. Utility is an important consideration when determining the most appropriate monitor for specific populations and environments. Hours of activity data collected, the reasons for activity hours not being recorded, and how these two factors might change over time when using an activity monitor in free living are rarely reported. This study investigated user perceptions, adherence to minimal wear time and loss of data when using the RT3 activity monitor in 21 healthy adults, in a variety of occupations, over three (7 day) repeated weeks of measurement in free living. An activity diary verified each day of monitoring and a utility questionnaire explored participant perceptions on the usability of the RT3. The RT3 was worn for an average of 14 h daily with 90% of participants having complete data sets. In total 6535.8 and 6092.5h of activity data were collected from the activity diary and the RT3 respectively. An estimated 443.3h (6.7%) of activity data were not recorded by the RT3. Data loss was primarily due to battery malfunction (45.2%). Non-adherence to wear time accounted for 169.5h (38.2%) of data loss, of which 14 h were due to occupational factors. The RT3 demonstrates good utility for free living activity measurement, however, technical issues and strategies to manage participant adherence require consideration with longitudinal and repeated measures studies. PMID- 19875100 TI - Development of an intervention to prevent work-related musculoskeletal disorders among hospital nurses based on the participatory approach. AB - The participatory approach has been widely used to improve the work environment. The purpose of this study was to develop an intervention to prevent work-related musculoskeletal disorders in hospital nurses using the participatory approach. Based on the Participatory Action Oriented Training (PAOT) approach, the multidisciplinary team conducted the trainer workshop to develop a comprehensive intervention protocol, which yielded several practical and low-cost solutions to reduce the risk factors for musculoskeletal disorders. Structured tools that were focused on the hospital environment were developed. The developed action checklist consisted of 43 items that were focused on five areas of nursing tasks (i.e., patient care and treatment; safe handling of drugs, medical devices, and equipment; workstation design; physical environment; and welfare facilities and administration). The final intervention protocol consisted of a series of structured participant workshop, follow-up visits, and presentation of achievements. PMID- 19875101 TI - Can Rachman's indirect pathways be used to un-learn fear? A prospective paradigm to test whether children's fears can be reduced using positive information and modelling a non-anxious response. AB - This study investigated whether children's fears could be un-learned using Rachman's indirect pathways for learning fear. We hypothesised that positive information and modelling a non-anxious response are effective methods of un learning fears acquired through verbal information. One hundred and seven children aged 6-8 years received negative information about one animal and no information about another. Fear beliefs and behavioural avoidance were measured. Children were randomised to receive positive verbal information, modelling, or a control task. Fear beliefs and behavioural avoidance were measured again. Positive information and modelling led to lower fear beliefs and behavioural avoidance than the control condition. Positive information was more effective than modelling in reducing fear beliefs and both methods significantly reduced behavioural avoidance. The results support Rachman's indirect pathways as viable fear un-learning pathways and supports associative learning theories. PMID- 19875102 TI - When self-help is no help: traditional cognitive skills training does not prevent depressive symptoms in people who ruminate. AB - A randomized trial was conducted to test the efficacy of three self-directed prevention intervention workbooks for depression. Cognitively at-risk college freshmen were randomly assigned to one of three conditions: traditional cognitive, non-traditional cognitive, and academic skills. Consistent with hypotheses, participants who were high in rumination and experienced stress exhibited significantly greater levels of depressive symptoms after completing the traditional cognitive skills workbook than after completing the other two workbooks. This pattern of results held post-intervention and 4 months later. These findings indicate that rumination may hinder ones ability to identify and dispute negative thoughts (at least without the help of a trained professional). The results underscore the importance of identifying individual difference variables that moderate intervention efficacy. They also raise concerns about the potential benefits of self-help books, an industry that generates billions of dollars each year. PMID- 19875103 TI - Genomewide association study of movement-related adverse antipsychotic effects. AB - BACKGROUND: Understanding individual differences in the development of extrapyramidal side effects (EPS) as a response to antipsychotic therapy is essential to individualize treatment. METHODS: We performed genomewide association studies to search for genetic susceptibility to EPS. Our sample consisted of 738 schizophrenia patients, genotyped for 492K single nucleotide polymorphisms (SNPs). We studied three quantitative measures of antipsychotic adverse drug reactions-the Simpson-Angus Scale (SAS) for Parkinsonism, the Barnes Akathisia Rating Scale, and the Abnormal Involuntary Movement Scale (AIMS)-as well as a clinical diagnosis of probable tardive dyskinesia. RESULTS: Two SNPs for SAS, rs17022444 and rs2126709 with p = 1.2 x 10(-10) and p = 3.8 x 10(-7), respectively, and one for AIMS, rs7669317 with p = 7.7 x 10(-8), reached genomewide significance (Q value < .1). rs17022444 and rs7669317 were located in intergenic regions and rs2126709 was located in ZNF202 on 11q24. Fourteen additional signals were potentially interesting (Q value < .5). The ZNF202 is a transcriptional repressor controlling, among other genes, PLP1, which is the major protein in myelin. Mutations in PLP1 cause Pelizaeus-Merzbacher disease, which has Parkinsonism as an occurring symptom. Altered mRNA expression of PLP1 is associated with schizophrenia. CONCLUSIONS: Although our findings require replication and validation, this study demonstrates the potential of genomewide association studies to discover genes and pathways that mediate adverse effects of antipsychotics. PMID- 19875105 TI - Concomitant dehydration mechanisms in single crystals of alpha,alpha-trehalose. AB - The dehydration behaviour of alpha,alpha-trehalose (alpha-D-glucopyranosyl alpha D-glucopyranoside) dihydrate single crystals is investigated by thermomicroscopy, Raman microscopy, and differential scanning calorimetry. The results show at a given stage the simultaneous presence of two polymorphic forms, amorphous material, and movement of a fluid phase. The study also underlines that the characterization of the average phase by conventional XRPD and DSC techniques is not sufficient to describe the dehydration mechanisms of alpha,alpha-trehalose particles. Moreover, it confirms that the dehydration behaviour is mainly driven by heterogeneities and the rate of water loss. PMID- 19875104 TI - Aversive imagery in posttraumatic stress disorder: trauma recurrence, comorbidity, and physiological reactivity. AB - BACKGROUND: Posttraumatic stress disorder (PTSD) is characterized as a disorder of exaggerated defensive physiological arousal. The novel aim of the present research was to investigate within PTSD a potential dose-response relationship between past trauma recurrence and current comorbidity and intensity of physiological reactions to imagery of trauma and other aversive scenarios. METHODS: A community sample of principal PTSD (n = 49; 22 single-trauma exposed, 27 multiple-trauma exposed) and control (n = 76; 46 never-trauma exposed, 30 trauma exposed) participants imagined threatening and neutral events while acoustic startle probes were presented and the eye-blink response (orbicularis occuli) was recorded. Changes in heart rate, skin conductance level, and facial expressivity were also indexed. RESULTS: Overall, PTSD patients exceeded control participants in startle reflex, autonomic responding, and facial expressivity during idiographic trauma imagery and, though less pronounced, showed heightened reactivity to standard anger, panic, and physical danger imagery. Concerning subgroups, control participants with and without trauma exposure showed isomorphic patterns. Within PTSD, only the single-trauma patients evinced robust startle and autonomic responses, exceeding both control participants and multiple trauma PTSD. Despite greater reported arousal, the multiple-trauma relative to single-trauma PTSD group showed blunted defensive reactivity associated with more chronic and severe PTSD, greater mood and anxiety disorder comorbidity, and more pervasive dimensional dysphoria (e.g., depression, trait anxiety). CONCLUSIONS: Whereas PTSD patients generally show marked physiological arousal during aversive imagery, concordant with self-reported distress, the most symptomatic patients with histories of severe, cumulative traumatization show discordant physiological hyporeactivity, perhaps attributable to sustained high stress and an egregious, persistent negative affectivity that ultimately compromises defensive responding. PMID- 19875106 TI - I-TAC is a dominant chemokine in controlling skin intragraft inflammation via recruiting CXCR3+ cells into the graft. AB - Chemokines play a critical role in the acute transplant rejection. In order to provide an overview of the chemokine expression during the course of acute allograft rejection, the intragraft expression profile of 11 chemokines representative of all four chemokine subfamilies was analyzed in a murine skin transplantation model of acute rejection. It was found that RANTES/CCL5, TARC/CCL17 and FKN/CX(3)CL1 were expressed at equivalent levels in iso- and allografts. However, the other eight chemokines expression was up-regulated to some extent in allograft compared with that in isograft. The levels of MIP 1alpha/CCL3, MIP-3alpha/CCL20 and CTACK/CCL27 were progressively increased from early stage (day 3 post-transplantation) to late stage (day 11). Mig/CXCL9, IP 10/CXCL10, I-TAC/CXCL11, CXCL16 and LTN/XCL1 expression was elevated at middle stage (day 7), and peaked at late stage. Among the up-regulated chemokines, I-TAC was the most obviously elevated chemokine. Therefore, the effect of I-TAC on the skin acute allograft rejection was evaluated. Block of I-TAC by the intradermal injection of anti-I-TAC monoclonal antibody (mAb) reduced the number of CXCR3(+) cells in skin allograft and significantly prolonged the skin allograft survival. The mAb treatment did not influence the proliferation of the intragraft infiltrating cells in response to the allogeneic antigens, but significantly decreased the number of the infiltrating cells and consequently lowered the secretion of IFN-gamma and TNF-alpha. These data indicate I-TAC might be a dominant chemokine involved in the intradermal infiltration and I-TAC-targeted intervening strategies would have potential application for the alleviation of acute transplant rejection. PMID- 19875107 TI - [Colon metastasis of lobular breast cancer]. PMID- 19875108 TI - [Intestinal invagination in adults: Presentation of a case and a review of the Spanish literature]. AB - INTRODUCTION: Intestinal invagination in the adult is an uncommon condition, often manifested by non-specific chronic or sub-acute symptoms. In the majority of occasions there is an organic lesion. There are currently no large patient series published in the literature to help define the management of these patients. MATERIAL AND METHOD: A review of case series published in the Spanish literature. A data base of patients over 15 years old was designed. Data was extracted from national clinical cases using Internet resources. Our own recent clinical case is added. RESULTS: A series of 30 adults with intestinal invagination was obtained (29 cases from the review and one own). The median age was 45 years (19-84 years) and 17/30 (57%) were males. A total of 27/30 patients had abdominal pain and 8/30 (28%) cases had established intestinal obstruction. The preoperative diagnosis of invagination was made in 25/30 (83%) of patients. The invaginations were; enteroenteric, 61%; colocolic, 12%; enterocolic, 21%; and gastrojejunal, 6%. A total of 85% of the invaginations were associated with a proliferative lesion and 43% of the latter were malignant. CONCLUSIONS: The diagnosis of invagination in the adult is usually made preoperatively. There are no data to support intestinal resection without performing a reduction. Resection must be the norm and the presence of lymph nodes is no argument to perform large resections. PMID- 19875109 TI - [Hand assistance is an alternative to conversion to laparotomy during laparoscopic sigmoidectomy]. AB - INTRODUCTION: Laparoscopic surgery in the treatment of diverticular disease offers multiple benefits compared with its open surgery counterpart. There are two distinct techniques, the laparoscopically assisted and the laparoscopic hand assisted approach. The purpose of this study is to demonstrate that the hand assisted approach can be used if, during a laparoscopically assisted approach, there is difficulty in dissection and/or exposure, and before performing a laparotomy. MATERIAL AND METHODS: This study is a retrospective cohort series that was performed in a private tertiary hospital in Mexico City. Patients with the diagnosis of diverticular disease who underwent a laparoscopically assisted sigmoidectomy were selected. These included patients who, during their procedure required conversion to a hand assisted approach. RESULTS: A total of 47 sigmoid colectomies began with assisted laparoscopy, of which 33 were completed, 4 required laparotomy, and 10 where completed using hand assistance (none required laparotomy). There were no statistically significant differences in return of bowel function (P=0.879) and postoperative hospital stay (P=0.679) between the group that was completed by assisted laparoscopy vs. hand assisted. CONCLUSIONS: If there is difficulty in exposure or dissection during a laparoscopically assisted sigmoid colectomy, the hand assisted approach is an alternative before the laparotomy. PMID- 19875110 TI - Forming intentions successfully: Differential compensational mechanisms of adolescents and old adults. AB - INTRODUCTION: Forming an intention is a key aspect of prospective memory, i.e., the ability to encode, retain, and later realize an intention with a delay of minutes, hours or days. Behavioural and neurophysiological findings from both prospective and retrospective memory research suggest that the efficiency of encoding processes is reduced at both ends of the lifespan and that neural generators underlying successful encoding might differ in childhood and old age. Hence, the present study investigates compensational neural mechanisms during the encoding of intentions in adolescents and old adults compared to young adults. METHODS: We compared Event-Related Potentials (ERPs) and their source localization in 14 adolescents (11-13 years), 14 young adults (18-25 years), and 14 old adults (64-79 years) in a prospective memory task that was embedded in a semantic categorization task. RESULTS: Our data revealed three event-related modulations that differentiate between conditions (i.e., ongoing activity and successful intention formation trials) and groups. Source localizations of these modulations with standardized low-resolution electromagnetic tomography (sLORETA) revealed compensational activations in adolescents and old adults compared to young adults in successful intention formation trials: while adolescents showed a higher activation of secondary occipital regions in the time window of 500-1200 msec with a maximum around 800 msec, old adults activated prefrontal regions to a greater extent beginning at 700 msec, persisting until 1200 msec and expanding to middle temporal regions. CONCLUSION: For a successful encoding of intentions adolescents and old adults recruit more neural generators than young adults. More importantly, the pattern of these compensational activations is different when comparing adolescents with young adults and old adults with young adults. These differences are discussed with regard to differential maturational changes in the brain. PMID- 19875111 TI - Cadmium, follicle-stimulating hormone, and effects on bone in women age 42-60 years, NHANES III. AB - BACKGROUND: Increased body burden of environmental cadmium has been associated with greater risk of decreased bone mineral density (BMD) and osteoporosis in middle-aged and older women, and an inverse relationship has been reported between follicle-stimulating hormone (FSH) and BMD in middle-aged women; however, the relationships between cadmium and FSH are uncertain, and the associations of each with bone loss have not been analyzed in a single population. OBJECTIVES: The objective of this study was to evaluate the associations between creatinine adjusted urinary cadmium (UCd) and FSH levels, and the associations between UCd and FSH with BMD and osteoporosis, in postmenopausal and perimenopausal women aged 42-60 years. METHODS: Data were obtained from the Third National Health Examination and Nutrition Survey, 1988-1994 (NHANES III). Outcomes evaluated were serum FSH levels, femoral bone mineral density measured by dual energy X-ray absorptiometry, and osteoporosis indicated by femoral BMD cutoffs based on the international standard. Urinary cadmium levels were analyzed for association with these outcomes, and FSH levels analyzed for association with bone effects, using multiple regression. Subset analysis was conducted by a dichotomous measure of body mass index (BMI) to proxy higher and lower adipose-synthesized estrogen effects. RESULTS: UCd was associated with increased serum FSH in perimenopausal women with high BMI (n=642; beta=0.45; p< or =0.05; R(2)=0.35) and low BMI (n=408; beta=0.61; p< or =0.01; R(2)=0.34). Among perimenopausal women with high BMI, BMD was inversely related to UCd (beta=-0.04; p< or =0.05) and FSH (beta= 0.03; p< or =0.05). In postmenopausal women with low BMI, an incremental increase in FSH was associated with 2.78 greater odds for osteoporosis (109 with and 706 without) (OR=2.78; 95% CI=1.43, 5.42; p< or =0.01). CONCLUSION: Long-term cadmium exposure at environmental levels is associated with increased serum FSH, and both FSH and UCd are associated with bone loss, in US women aged 42-60 years. PMID- 19875112 TI - Body mass index in Serbian Roma. AB - Stature and body mass were measured in 346 individuals belonging to three Roma groups from metropolitan Belgrade western Serbia. As with the majority of Serbian Roma, the participants in this study have been historically disadvantaged and their situation was further aggravated during the recent political crises. Surprisingly, the body mass index (BMI) of Serbian Roma is relatively high compared with western Europeans and is inconsistent with the view that Serbian Roma are predisposed to high rates of chronic energy deficiency ( approximately 4%). While the majority of individual Roma display BMI values within the normal range (WHO, 1995), certain groups have a moderate to high proportion of individuals ( approximately 35%) who could be classified as overweight and some who approach at-risk levels for clinical obesity. PMID- 19875113 TI - Cognitions associated with nurse performance: a comparison of concurrent and retrospective verbal reports of nurse performance in a simulated task environment. AB - BACKGROUND: Cognitions represent the computations associated with human thought processes. Verbal protocols offer a method by which to record these processes. While concurrent and retrospective verbal reporting of cognitions have been used extensively within nursing and other domains, the use of this methodology in nursing has been characterized by inconsistencies in its application. OBJECTIVES: The primary objective of this study was to describe and compare the content of concurrent and retrospective verbal reports provided by nurses during and after administering care in a simulated task environment. DESIGN: The study utilized a laboratory based quasi-experimental research design. SETTING: The study was based in a simulation laboratory designed specifically for use in studies designed to measure nursing performance. The laboratory integrated extensive instrumentation that facilitated the comprehensive audio and video recording of participant actions. PARTICIPANTS: The participants (N=15) were recruited from a College of Nursing at a large university in the Southeastern United States. METHODS: Research participants were asked to admit a patient experiencing an acute exacerbation of congestive heart failure in a simulated task environment, during which they were required to prioritize and provide care. Participants were trained in the method for providing verbal reports of thoughts, and concurrent and retrospective report data were collected during and after the simulation exercise. The data were then coded for the purposes of descriptive analysis. RESULTS: The results indicated that the concurrent verbal reports provide a more complete representation of the cognitions of research participants providing care in a simulated task environment. However, the results reflect that additional unique data is present in the retrospective reports, exclusive of the concurrent reports. CONCLUSIONS: The findings support the utility of concurrent and retrospective verbal reports as a method of gathering data in studies that address nursing performance in a clinical context. PMID- 19875114 TI - A novel mouse model of in-stent restenosis. AB - BACKGROUND AND AIMS: In-stent restenosis (ISR) is the major complication that occurs after percutaneous coronary interventions to facilitate coronary revascularization. Herein we described a simple and cost-effective model, which reproduces important features of ISR in the mouse. METHODS AND RESULTS: Microvascular bare metal stents were successfully implanted in the abdominal aorta of atherosclerotic ApoE-null mice. Patency of implanted stents was interrogated using ultrasound biomicroscopy. Aortas were harvested at different time points after implantation and processed for histopathological analysis. Thrombus formation was histologically detected after 1 day. Leukocyte adherence and infiltration were evident after 7 days and decreased thereafter. Neointimal formation, neointimal thickness and luminal stenosis simultaneously increased up to 28 days after stent implantation. Using multichannel fluorescence molecular tomography (FMT) for spatiotemporal resolution of MMP activities, we observed that MMP activity in the stented aorta of Apo-E null mice was 2-fold higher than that of wild-type mice. Finally, we compared neointimal formation in response to stenting in two genetically different mouse strains. In-stent neointimas in FVB/NJ mice were 2-fold thicker than in C57BL/6J mice (p=0.002). CONCLUSION: We have developed a model that can take advantage of the multiple genetic resources available for the mouse to study the mechanisms of in-stent restenosis. PMID- 19875115 TI - Modulation of Ca(2+) signalling in human vascular endothelial cells by hydrogen sulfide. AB - Hydrogen sulfide (H(2)S) is now recognised as an important endogenous antihypertensive molecule and is synthesised in the vasculature primarily by endothelial cystathionine gamma lyase. Activity of this enzyme, and the production of other vasoactive substances by the endothelium, are subject to modulation by changes of [Ca(2+)](i). Here, we have used microfluorimetry to investigate whether H(2)S can regulate human endothelial [Ca(2+)](i). H(2)S (applied via the donor NaHS, 5-500 microM) caused concentration-dependent rises of [Ca(2+)](i) which were attributable to release from an ATP- and 4-CEP sensitive intracellular pool. Rises of [Ca(2+)](i) evoked by H(2)S were essentially abolished by prior pool depletion. In the absence of external Ca(2+), H(2)S slowed the decay phase of responses to cyclopiazonic acid, but this could not be attributed to the inhibition of Ca(2+) extrusion since the effects of H(2)S were at least additive with the Na(+)/Ca(2+) exchange inhibitors bepridil and SEA 0400 and the Ca(2+) ATPase inhibitor, carboxyeosin. In some but not all the cells, re-exposure to extracellular Ca(2+) following the addition and removal of H(2)S activated capacitative Ca(2+) entry (CCE), and H(2)S increased ATP evoked (but not thapsigargin-evoked) CCE. Effects of H(2)S were not mediated by energy depletion or production of cyclic ADP ribose. Our data indicate that H(2)S can modulate endothelial [Ca(2+)](i) via multiple mechanisms, and such effects are likely to contribute to this gasotransmitter's beneficial actions. PMID- 19875116 TI - Comparing coronary artery calcium and thoracic aorta calcium for prediction of all-cause mortality and cardiovascular events on low-dose non-gated computed tomography in a high-risk population of heavy smokers. AB - BACKGROUND: Coronary artery calcium (CAC) and thoracic aorta calcium (TAC) can be detected simultaneously on low-dose, non-gated computed tomography (CT) scans. CAC has been shown to predict cardiovascular (CVD) and coronary (CHD) events. A comparable association between TAC and CVD events has yet to be established, but TAC could be a more reproducible alternative to CAC in low-dose, non-gated CT. This study compared CAC and TAC as independent predictors of all-cause mortality and cardiovascular events in a population of heavy smokers using low-dose, non gated CT. METHODS: Within the NELSON study, a population-based lung cancer screening trial, the CT screen group consisted of 7557 heavy smokers aged 50-75 years. Using a case-cohort study design, CAC and TAC scores were calculated in a total of 958 asymptomatic subjects who were followed up for all-cause death, and CVD, CHD and non-cardiac events (stroke, aortic aneurysm, peripheral arterial occlusive disease). We used Cox proportional-hazard regression to compute hazard ratios (HRs) with adjustment for traditional cardiovascular risk factors. RESULTS: A close association between the prevalence of TAC and increasing levels of CAC was established (p<0.001). Increasing CAC and TAC risk categories were associated with all-cause mortality (p for trend=0.01 and 0.001, respectively) and CVD events (p for trend <0.001 and 0.03, respectively). Compared with the lowest quartile (reference category), multivariate-adjusted HRs across categories of CAC were higher (all-cause mortality, HR: 9.13 for highest quartile; CVD events, HR: 4.46 for highest quartile) than of TAC scores (HR: 5.45 and HR: 2.25, respectively). However, TAC is associated with non-coronary events (HR: 4.69 for highest quartile, p for trend=0.01) and CAC was not (HR: 3.06 for highest quartile, p for trend=0.40). CONCLUSIONS: CAC was found to be a stronger predictor than TAC of all-cause mortality and CVD events in a high-risk population of heavy smokers scored on low-dose, non-gated CT. TAC, however, is stronger associated with non-cardiac events than CAC and could prove to be a preferred marker for these events. PMID- 19875117 TI - An injury risk curve for the hip for use in frontal impact crash testing. AB - To facilitate the assessment of hip injury risk in frontal motor-vehicle crashes, an injury risk curve that relates peak force transmitted to the hip to the probability of hip fracture was developed by using survival analysis to fit a lognormal distribution to a recently published dataset of hip fracture forces. This distribution was parameterized to account for the effect of subject stature, which was the only subject characteristic found to significantly affect hip fracture force (X(2)(1)=6.03, p=0.014). The distribution was further parameterized to account for the effects of hip flexion and abduction from a standard driving posture on hip fracture force using relationships between mean hip fracture force and hip flexion/abduction reported in the literature. The resulting parametric distribution was used to define relationships between force applied to the hip and the risk of hip fracture for the statures associated with the small female, midsize male, and large male crash-test dummies, thus allowing these dummies to assess hip fracture/dislocation risk in frontal crashes, provided that such dummies are sufficiently biofidelic. For the midsize male crash test dummy, a 50% risk of hip fracture was associated with a force of 6.00kN. For the small female and large male dummies, a 50% risk of hip fracture was associated with forces of 4.46 and 6.73kN, respectively. PMID- 19875118 TI - Exercise training changes the gating properties of large-conductance Ca2+ activated K+ channels in rat thoracic aorta smooth muscle cells. AB - Large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels play a critical role in regulating the cellular excitability in response to change in blood flow. It has been demonstrated that vascular BK(Ca) channel currents in both humans and rats are increased after exercise training. This up-regulation of the BK(Ca) channel activity in arterial myocytes may represent a cellular compensatory mechanism of limiting vascular reactivity to exercise training. However, the underlying mechanisms are not fully understood. In the present study, we examined the single channel activities and kinetics of the BK(Ca) channels in rat thoracic aorta smooth muscle cells. We showed that exercise training significantly increased the open probability (Po), decreased the mean closed time and increased the mean open time, and the sensitivity to Ca(2+) and voltage without altering the unitary conductance and the K(+) selectivity. Our results suggest a novel mechanism by which exercise training increases the K(+) currents by changing the BK(Ca) channel activities and kinetics. PMID- 19875119 TI - A finite element inverse analysis to assess functional improvement during the fracture healing process. AB - Assessment of the restoration of load-bearing function is the central goal in the study of fracture healing process. During the fracture healing, two critical aspects affect its analysis: (1) material properties of the callus components, and (2) the spatio-temporal architecture of the callus with respect to cartilage and new bone formation. In this study, an inverse problem methodology is used which takes into account both features and yields material property estimates that can analyze the healing changes. Six stabilized fractured mouse tibias are obtained at two time points during the most active phase of the healing process, respectively 10 days (n=3), and 14 days (n=3) after fracture. Under the same displacement conditions, the inverse procedure estimations of the callus material properties are generated and compared to other fracture healing metrics. The FEA estimated property is the only metric shown to be statistically significant (p=0.0194) in detecting the changes in the stiffness that occur during the healing time points. In addition, simulation studies regarding sensitivity to initial guess and noise are presented; as well as the influence of callus architecture on the FEA estimated material property metric. The finite element model inverse analysis developed can be used to determine the effects of genetics or therapeutic manipulations on fracture healing in rodents. PMID- 19875120 TI - In vivo estimation of the glenohumeral joint centre by functional methods: accuracy and repeatability assessment. AB - Several algorithms have been proposed for determining the centre of rotation of ball joints. These algorithms are used rather to locate the hip joint centre. Few studies have focused on the determination of the glenohumeral joint centre. However, no studies have assessed the accuracy and repeatability of functional methods for glenohumeral joint centre. This paper aims at evaluating the accuracy and the repeatability with which the glenohumeral joint rotation centre (GHRC) can be estimated in vivo by functional methods. The reference joint centre is the glenohumeral anatomical centre obtained by medical imaging. Five functional methods were tested: the algorithm of Gamage and Lasenby (2002), bias compensated (Halvorsen, 2003), symmetrical centre of rotation estimation (Ehrig et al., 2006), normalization method (Chang and Pollard, 2007), helical axis (Woltring et al., 1985). The glenohumeral anatomical centre (GHAC) was deduced from the fitting of the humeral head. Four subjects performed three cycles of three different movements (flexion/extension, abduction/adduction and circumduction). For each test, the location of the glenohumeral joint centre was estimated by the five methods. Analyses focused on the 3D location, on the repeatability of location and on the accuracy by computing the Euclidian distance between the estimated GHRC and the GHAC. For all the methods, the error repeatability was inferior to 8.25 mm. This study showed that there are significant differences between the five functional methods. The smallest distance between the estimated joint centre and the centre of the humeral head was obtained with the method of Gamage and Lasenby (2002). PMID- 19875121 TI - A numerical model of cellular blebbing: a volume-conserving, fluid-structure interaction model of the entire cell. AB - In animal cells, blebs are smooth, quasi-hemispherical protrusions of the plasma membrane that form when a section of the membrane detaches from the underlying actin cytoskeleton and is inflated by flowing cytosol. The mechanics behind this common cellular activity are not yet clear. As a first step in the development of a full computational framework, we present a numerical model of overall cell behavior based upon the interaction between a background Newtonian-fluid cytosol and elastic structures modeling the membrane and filaments. The detailed micromechanics of the cytoskeletal network are the subject of future work. Here, the myosin-driven contraction of the actin network is modeled through stressed elastic filaments. Quantitative models of cytoskeletal micromechanics and biochemistry require accurate estimates of local stress and flow conditions. The main contribution of this paper is the development of a computationally efficient fluid-structure interaction model based on operator splitting, to furnish this data. Cytosol volume conservation (as supported by experimental evidence) is enforced through an intermediate energy minimization step. Realistic bleb formation and retraction is observed from this model, offering an alternative formulation to positing complex continuum behavior of the cytoplasm (e.g. poroelastic model of Charras et al., 2008). PMID- 19875122 TI - Rib fractures under anterior-posterior dynamic loads: experimental and finite element study. AB - The purpose of this study was to investigate whether using a finite-element (FE) mesh composed entirely of hexahedral elements to model cortical and trabecular bone (all-hex model) would provide more accurate simulations than those with variable thickness shell elements for cortical bone and hexahedral elements for trabecular bone (hex-shell model) in the modeling human ribs. First, quasi-static non-injurious and dynamic injurious experiments were performed using the second, fourth, and tenth human thoracic ribs to record the structural behavior and fracture tolerance of individual ribs under anterior-posterior bending loads. Then, all-hex and hex-shell FE models for the three ribs were developed using an octree-based and multi-block hex meshing approach, respectively. Material properties of cortical bone were optimized using dynamic experimental data and the hex-shell model of the fourth rib and trabecular bone properties were taken from the literature. Overall, the reaction force-displacement relationship predicted by both all-hex and hex-shell models with nodes in the offset middle cortical surfaces compared well with those measured experimentally for all the three ribs. With the exception of fracture locations, the predictions from all hex and offset hex-shell models of the second and fourth ribs agreed better with experimental data than those from the tenth rib models in terms of reaction force at fracture (difference <15.4%), ultimate failure displacement and time (difference <7.3%), and cortical bone strains. The hex-shell models with shell nodes in outer cortical surfaces increased static reaction forces up to 16.6%, compared to offset hex-shell models. These results indicated that both all-hex and hex-shell modeling strategies were applicable for simulating rib responses and bone fractures for the loading conditions considered, but coarse hex-shell models with constant or variable shell thickness were more computationally efficient and therefore preferred. PMID- 19875123 TI - Computational study on the effect of loading alteration caused by disc degeneration on the trabecular architecture in human lumbar spine. AB - A thorough understanding of age-related phenomena on the trabecular architecture in the human lumbar spine can help the diagnosis and prognosis of age-related architectural changes, and provide an insight into the corresponding clinical assessments. In this paper we considered the different loading conditions of the young and old lumbar spines mainly caused by disc degeneration and studied the effect of loading alteration on trabecular architecture in lumbar spines. A two dimensional muFE models with a 40mum pixel resolution were built to represent the full trabecular architecture in the human lumbar spine, and a topology optimization with the aid of finite element method was conducted to numerically investigate the trabecular morphological changes. Topology optimization iteratively distributes material in a design domain producing optimal layout or configuration, and it has been widely and successfully used for the study of bone remodeling. As a result of adaptive response of bone remodeling due to different loading conditions, we obtained two distinctively different trabecular architectures for the young and old lumbar spines, and we observed a strong correlation between our numerical results and the actual trabecular architecture in the literature. The proposed numerical framework and results demonstrated the potential use of the topology optimization-based numerical tool for putative treatments in advance of actual clinical procedures for the patients. PMID- 19875124 TI - On-line solid-phase extraction of large-volume injections coupled to liquid chromatography-tandem mass spectrometry for the quantitation and confirmation of 14 selected trace organic contaminants in drinking and surface water. AB - We describe the development and validation of an on-line solid-phase extraction of large-volume injections coupled to liquid chromatography-tandem mass spectrometry method for the simultaneous quantitation and confirmation of 14 selected trace organic contaminants in drinking and surface water. Selected compounds were: anti-infectives (clarithromycin, sulfamethoxazole and trimethoprim), an anticonvulsant (carbamazepine) and its transformation product 10,11-dihydrocarbamazepine, an antihypertensive (enalapril), antineoplastics (cyclophosphamide and methotrexate), herbicides (atrazine, cyanazine, and simazine) and two of their transformation products (deethylatrazine and deisopropylatrazine) and an antiseptic (triclocarban). The breakthrough volume determinations showed that out of all the investigated sorbents, the Strata-X on line solid-phase extraction column showed the best performance. The method used a load volume of 10.0 mL and was validated using the corresponding matrices, yielding for most compounds, R(2)>0.99. Extraction recoveries ranged from 60 to 109%. The intra- and inter-day precision were <14 and <16%, respectively. The method detection limits ranged from 0.6 to 6 ng L(-1). Matrix effects were in general low. The performance of the on-line method was demonstrated with the analysis of real water samples. The application of alternative techniques of confirmation was also explored using accurate mass measurements on a time-of flight mass spectrometer and the data-dependent reverse energy ramp scan on a triple quadrupole. PMID- 19875125 TI - Transition from enantioselective high performance to ultra-high performance liquid chromatography: A case study of a brush-type chiral stationary phase based on sub-5-micron to sub-2-micron silica particles. AB - Three brush-type chiral stationary phases (CSPs) differing in the particle size of the starting silica particles have been prepared by covalent grafting of the pi-acidic bis-(3,5-dinitrobenzoyl)-derivative of trans-1,2-diaminocyclohexane (DACH-DNB). Starting silica particles of 4.3, 2.6 and 1.9micron were used to generate the final CSPs using an improved, highly reproducible synthetic methodology, that allowed to assemble and surface-graft the whole chiral selector in only two steps. The different CSPs have been packed in columns of various length and diameters, and fully characterized in terms of flow permeability, kinetic performances and enantioselectivity using a set of test solutes. Very high speed and high resolution applications together with stereodynamic HPLC examples are demonstrated on the columns with reduced particle diameters, on which separations of several enantiomeric pairs are routinely obtained with analysis times in the 15-40s range. PMID- 19875126 TI - Murine fecal proteomics: a model system for the detection of potential biomarkers for colorectal cancer. AB - Tumor related products shed into the feces offer a potential source of biomarkers for the detection of colorectal cancer (CRC). Using SDS-PAGE followed by nanoflow reversed-phased LC-MS/MS to analyse fecal samples from Apc(Min/+) mice (that develop spontaneous multiple intestinal neoplasia with age) we have identified 336 proteins (115 proteins of murine origin, 201 from fecal bacteria, 18 associated with food intake and 2 of apparent parasitic origin). 75% of the murine proteins identified in this study are predicted to be extracellular or associated with the cell plasma membrane. Of these proteins, a number of the murine homologues of colorectal cancer associated proteins (CCAP) such as hemoglobin, haptoglobin, hemopexin, alpha-2-macroglobulin and cadherin-17 have been identified, demonstrating the potential of fecal proteomics for detecting potential biomarkers and paving the way for subsequent MS/MS based biomarker studies on similar human samples. PMID- 19875127 TI - Functional silica nanoparticles synthesized by water-in-oil microemulsion processes. AB - Water-in-oil (W/O) microemulsion is a well-suitable confined reacting medium for the synthesis of structured functional nanoparticles of controlled size and shape. During the last decade, it allowed the synthesis of multi-functional silica nanoparticles with morphologies as various as core-shell, homogenous dispersion or both together. The morphology and properties of the different intermediates and final materials obtained through this route are discussed in the light of UV-Vis-NIR spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and magnetometer SQUID analysis. PMID- 19875128 TI - Adsorption of sodium polyacrylate in high solids loading calcium carbonate slurries. AB - The adsorption of sodium polyacrylate (NaPAA) in slurries with up to 75 wt.% calcium carbonate was investigated with the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and adsorption of probe molecules. Analysis of the IR spectra demonstrated that the carboxylate groups of NaPAA adsorbed onto ground calcium carbonate (GCC) in three different modes. These modes were shown to be dependent on the solids loading and age of the slurry. Further investigation lead to the determination of the chelating ability of NaPAA at high solids loading. PMID- 19875129 TI - Age differences in the rejection of false memories: the effects of giving warning instructions and slowing the presentation rate. AB - Two experiments were conducted to examine whether children of different ages differ in their ability to reject associative false memories with the Deese Roediger-McDermott (DRM) paradigm. Two different types of manipulations that are thought to facilitate false memory rejection in adults-slowing the presentation rate and issuing explicit warnings-were analyzed in younger and older children. The results showed that older children were more able than younger children to reject associative false memories through warnings and by slowing the presentation rate. We conclude that although older children are, in general, more prone to produce false memories with the DRM paradigm, they are also more able to reject them when certain conditions facilitate the editing process. PMID- 19875130 TI - FDG-PET mapping the brain substrates of visuo-constructive processing in Alzheimer's disease. AB - The anatomical basis of visuo-constructive impairment in AD is widely unexplored. FDG-PET can be used to determine functional neuronal networks underlying specific cognitive performance in the human brain. In the present study, we determined the pattern of cortical metabolism that was associated with visuo-constructive performance in AD. We employed two widely used visuo-constructive tests that differ in their demand on visual perception and processing capacity. Resting state FDG-PET scans were obtained in 29 probable AD patients, and cognitive tests were administered. We made a voxel-based regression analysis of FDG uptake to scores in visual test performance, using the SPM5 software. Performance in the CERAD Drawing test correlated with FDG uptake in the bilateral inferior temporal gyri, bilateral precuneus, right cuneus, right supramarginal gyrus and right middle temporal gyrus covering areas of dorsal and ventral visual streams. In contrast, performance in the more complex RBANS Figure Copy test correlated with FDG uptake in the bilateral fusiform gyri, right inferior temporal gyrus, left anterior cingulate gyrus, left parahippocampal gyrus, right middle temporal gyrus and right insula, encompassing the ventral visual stream and areas of higher level visual processing. The study revealed neuronal networks underlying impaired visual test performance in AD. The extent of involvement of visual and higher order association cortex increased with greater test complexity. From a clinical point of view, both of these widely used visual tests evaluate the integrity of complementary cortical networks and may contribute complementary information on the integrity of visual processing in AD. PMID- 19875131 TI - The impact of fear for family on mental health in a resettled Iraqi refugee community. AB - The current study aimed to evaluate the impact of fear for family remaining in the country of origin and under potential threat on the mental health of refugees. Adult Mandaean refugees (N=315) from Iraq, living in Sydney, Australia, were interviewed regarding fear for family in Iraq, fear of genocide, pre migration trauma, post-migration living difficulties and psychological outcomes. Participants with immediate family in Iraq reported higher levels of symptoms of PTSD and depression, and greater mental health-related disability than those without family in Iraq. Intrusive fears about family independently predicted risk of PTSD, depression and disability after controlling for trauma exposure and current living difficulties. Threat to family members living in a context of ongoing threat predicted psychopathology and disability in Mandaean refugees. The effect of ongoing threat to family still living in conflict-ridden countries on the mental health of refugees should be further considered in the context of healthcare. PMID- 19875133 TI - Natural history of solitary cerebral cysticercosis on serial magnetic resonance imaging and the effect of albendazole therapy on its evolution. AB - AIM: To describe the evolution of imaging characteristics of solitary cerebral cysticercal lesions (SCCL) on serial MRI, and to study the effect of treatment with albendazole. DESIGN: Randomised controlled prospective trial. METHODS AND MATERIAL: 123 patients with new-onset seizures and SCCL on contrast MRI were randomised to treatment with albendazole and followed with up to five serial MRIs. RESULTS: 81 patients (M - 41, F - 40) with mean age of 19.6+/-11.7years and 4 or 5 serial MRI were included in the analysis. Analysis was performed on 356 MRI's. Scolex was seen in 61.9% of patients in postcontrast T1 sequence in the first MRI study, and there was a significant drop in visibility from the next scan onwards. Cyst contents were initially T1-hypointense and T2-hyperintense with inversion on FLAIR in 30.8% and later scans showed T2-hypointensity. Cyst wall characteristics changed significantly from initially T2-hypointensity to later hyperintense rim. Initial scan revealed perilesional oedema in 98.5%, which is resolved by the second scan. Around 17.5% showed subtle perilesional T2 hyperintensity in follow-up scans. Enhancement pattern changed significantly from ring to disc, and later to non-enhancement. Initially, 69.7% lesions were in colloid-vesicular stage. Lesions moved through subsequent stages of cyst degeneration: time needed for this process is described. Imaging characteristics, both on the first and on subsequent scans, did not differ between albendazole and control groups. CONCLUSIONS: Evolution of SCCL follows a predictable sequence corresponding to morphologic stages described earlier, taking over a year to complete. Contrast enhancement decreases as degeneration progresses, but some calcific lesions continue to enhance. Albendazole therapy may hasten resolution of inflammation around the lesion but affects neither the morphology of the cysticercus nor the process of degeneration and subsequent healing. PMID- 19875132 TI - Mutation analysis of the SPG4 gene in Italian patients with pure and complicated forms of spastic paraplegia. AB - Mutations in the SPG4 gene are the most common causes of hereditary spastic paraplegia (HSP) accounting for up to 40% of autosomal dominant (AD) forms and 12 18% of sporadic cases. The phenotype associated with HSP due to mutations in the SPG4 gene tends to be pure. There is increasing evidence, however, of patients with complicated forms of spastic paraplegia in which SPG4 mutations were identified. A cohort of 38 unrelated Italian patients with spastic paraplegia, of which 24 had a clear dominant inheritance and 14 were apparently sporadic, were screened for mutations in the SPG4 gene. We identified 11 different mutations, six of which were novel (p.Glu143GlyfsX8, p.Tyr415X, p.Asp548Asn, c.1656_1664delinsTGACCT, c.1688-3C>G and c.*2G>T) and two exon deletions previously reported. The overall rate of SPG4 gene mutation in our patients was 36.8% (14/38); in AD-HSP we observed a mutation frequency of 45.8% (11/24), in sporadic cases the frequency was 21.4% (3/14). Furthermore, we found a mutational rate of 22.2% (2/9) and 41.4% (12/29) in the complicated and pure forms, respectively. The results underlie the importance of genetic testing in all affected individuals. PMID- 19875134 TI - Penumbra, the basis of neuroimaging in acute stroke treatment: current evidence. AB - In modern medicine brain imaging is an essential prerequisite not only to acute stroke triage but also to determining the specific therapy indicated. This article reviews the need for imaging the brain in acute stroke, penumbral pathophysiology, penumbral imaging techniques, as well as current status of various imaging modalities that are being employed to select patients for specific therapeutic approaches. PMID- 19875135 TI - A Bayesian hierarchical modeling approach for analyzing observational data from marine ecological studies. AB - We introduce the Bayesian hierarchical modeling approach for analyzing observational data from marine ecological studies using a data set intended for inference on the effects of bottom-water hypoxia on macrobenthic communities in the northern Gulf of Mexico off the coast of Louisiana, USA. We illustrate (1) the process of developing a model, (2) the use of the hierarchical model results for statistical inference through innovative graphical presentation, and (3) a comparison to the conventional linear modeling approach (ANOVA). Our results indicate that the Bayesian hierarchical approach is better able to detect a "treatment" effect than classical ANOVA while avoiding several arbitrary assumptions necessary for linear models, and is also more easily interpreted when presented graphically. These results suggest that the hierarchical modeling approach is a better alternative than conventional linear models and should be considered for the analysis of observational field data from marine systems. PMID- 19875136 TI - Detection of antibiotic resistant bacteria inhabiting the sand of non recreational marine beach. AB - The present study examined the antibiotic resistance of heterotrophic bacteria, which were isolated from the sand of the beach located in the National Park of the southern Baltic Sea coast. The bacteria demonstrated low levels of antibiotic resistance. These microorganisms were the most resistant to cefaclor and clindamycin and the most sensitive to clarithromycin, doxycycline, gentamycin and oxytetracycline. The majority of bacteria inhabiting the sand of the studied beach were resistant to only one antibiotic out of 18 tested antibiotics in this study. The bacteria inhabiting the middle part of the beach and the dune were more antibiotic resistant than bacteria isolated from the seawater and the shoreline-seawater contact zone. Generally, there was no significant difference in antibiotic resistance between bacteria isolated from the surface and the subsurface sand layers. The bacterial antibiotic resistance level depends on the chemical structure of antibiotics. PMID- 19875137 TI - Saponins and a lignan derivative of Terminalia tropophylla from the Madagascar Dry Forest. AB - A study of an EtOH extract obtained from the roots of the Madagascan plant Terminalia tropophylla H. Perrier (Combretaceae) led to isolation of the oleanane type triterpenoid saponin 1, the lignan derivative 2, and the two known saponins arjunglucoside I (3) and sericoside (4). The structures of compounds 1 (terminaliaside A) and 2 (4'-O-cinnamoyl cleomiscosin A) were elucidated using 1D and 2D NMR experiments and mass spectrometry. Compound 1 showed antiproliferative activity against the A2780 human ovarian cancer cell line with an IC(50) value of 1.2 microM. PMID- 19875139 TI - Active cigarette smoking, secondhand smoke exposure at work and home, and self rated health. AB - OBJECTIVES: Although active smoking has been reported to be associated with poor self-rated health (SRH), its association with secondhand smoke (SHS) is not well understood. STUDY DESIGN: A cross-sectional study was conducted to examine the association of active smoking and SHS exposure with SRH. METHODS: A total of 2558 workers (1899 men and 689 women), aged 16-83 (mean 45) years, in 296 small and medium-sized enterprises were surveyed by means of a self-administered questionnaire. Smoking status and exposure levels to SHS (no, occasional or regular) among lifetime non-smokers were assessed separately at work and at home. SRH was assessed with the question: How would you describe your health during the past 1-year period (very poor, poor, good, very good)? SRH was dichotomized into suboptimal (poor, very poor) and optimal (good, very good). Odds ratios (ORs) with 95% confidence intervals (CIs) for reporting suboptimal vs optimal SRH according to smoking status and smoke exposure were calculated. RESULTS: Current heavy smokers (20+ cigarettes/day) had a significantly increased suboptimal SRH than lifetime non-smokers after adjusting for sociodemographic, lifestyle, physical and occupational factors (OR 1.34, 95% CI 1.06-1.69). Similarly, lifetime non-smokers occasionally exposed to SHS at work alone had worse SRH than their unexposed counterparts (OR 1.50, 95% CI 1.02-2.11). In contrast, lifetime non-smokers exposed at home alone had no significant increase in suboptimal SRH. CONCLUSIONS: The present study indicates an increase in suboptimal SRH among current heavy smokers, and suggests that SHS exposure at work is a possible risk factor for non-smokers. Whether or not the association is causal, control of smoking at work may protect workers from developing future health conditions. PMID- 19875138 TI - Covalent interaction of ascorbic acid with natural products. AB - While ascorbic acid (vitamin C) is mostly known as a cofactor for proline hydroxylase and as a biological antioxidant, it also forms covalent bonds with natural products which we here refer to as 'ascorbylation'. A number of natural products containing an ascorbate moiety has been isolated and characterized from a variety of biological sources, ranging from marine algae to flowering plants. Most of these compounds are formed either as a result of nucleophilic substitution or addition by ascorbate, e.g. the ascorbigens from Brassica species are ascorbylated indole derivatives. Some ascorbylated tannins appear to be formed from electrophilic addition to dehydroascorbic acid. There are also examples of annulations of ascorbate with dietary polyphenols, e.g. epigallocatechin gallate (EGCG) and resveratrol derivatives. Herein is a survey of 33 ascorbylated natural products and their reported biological activities. PMID- 19875140 TI - Influenza vaccine uptake among staff in care homes in Nottinghamshire: a random cluster sample survey. AB - OBJECTIVES: To establish uptake of influenza vaccine amongst care home clinical staff in Greater Nottingham, and to investigate what could be done to improve vaccine uptake in this group. STUDY DESIGN: Postal questionnaire surveys were used. In the first instance, a total sample survey was used. In the second instance, a sample of care home staff was surveyed, randomized at the care home level. METHODS: A postal questionnaire completed by care home matrons was used to obtain a preliminary estimate of staff vaccine uptake. Individual staff questionnaires were then used to validate this finding, and measure attitudes, beliefs and behaviours associated with vaccination. RESULTS: Vaccine uptake among those working in care homes with nursing was found to be low. Vaccine uptake was higher in homes with a policy recommending vaccination of staff. Most respondents who had received vaccination reported that they had done so because of an existing medical condition, rather than because of being a healthcare worker. A statistically significant relationship (P=0.02) was found between individuals' reported beliefs on how well they could resist influenza and their vaccination status. CONCLUSIONS: All care homes for the elderly should have a vaccination policy which recommends staff vaccination. Educational campaigns, vaccination in the workplace and free provision of the influenza vaccine may help to improve vaccine uptake in this group. PMID- 19875142 TI - Elastic waves in noncohesive frictionless granular crystals. AB - An ordered structure of noncohesive spherical beads constitutes a phononic crystal. This type of media combines the properties of wave propagation in phononic crystals (dispersion due to the geometrical periodicity) with the properties of wave propagation in granular media (nonlinearities, rotational degree of freedom) and gives the opportunity to have interesting features as tunable frequency band gaps for example. In this work, the acoustic bulk modes of a hexagonal close packed (hcp) structure of beads, considered as rigid masses connected by springs, are theoretically evaluated and their associated resonance frequencies are compared to experimental results. When friction is neglected, the elastic interaction between the beads are reduced to a normal spring interaction given by the Hertz theory. According to this theory, the rigidity of the contact depends on its static loading. The theory predicts the existence of elastic transverse and longitudinal acoustical-type modes and transverse and longitudinal optical-type modes. The acoustic transfer function of a hcp crystal slab built with stainless steel beads is measured and its resonance frequencies are compared to the theoretical predictions. Despite some differences between theory and experiments, which could come for instance from the disordered character of the contact loads, the developed theory and the experimental results show relatively good agreement. PMID- 19875143 TI - Microfoam formation in a capillary. AB - The ultrasound-induced formation of bubble clusters may be of interest as a therapeutic means. If the clusters behave as one entity, i.e., one mega-bubble, its ultrasonic manipulation towards a boundary is straightforward and quick. If the clusters can be forced to accumulate to a microfoam, entire vessels might be blocked on purpose using an ultrasound contrast agent and a sound source. In this paper, we analyse how ultrasound contrast agent clusters are formed in a capillary and what happens to the clusters if sonication is continued, using continuous driving frequencies in the range 1-10 MHz. Furthermore, we show high speed camera footage of microbubble clustering phenomena. We observed the following stages of microfoam formation within a dense population of microbubbles before ultrasound arrival. After the sonication started, contrast microbubbles collided, forming small clusters, owing to secondary radiation forces. These clusters coalesced within the space of a quarter of the ultrasonic wavelength, owing to primary radiation forces. The resulting microfoams translated in the direction of the ultrasound field, hitting the capillary wall, also owing to primary radiation forces. We have demonstrated that as soon as the bubble clusters are formed and as long as they are in the sound field, they behave as one entity. At our acoustic settings, it takes seconds to force the bubble clusters to positions approximately a quarter wavelength apart. It also just takes seconds to drive the clusters towards the capillary wall. Subjecting an ultrasound contrast agent of given concentration to a continuous low-amplitude signal makes it cluster to a microfoam of known position and known size, allowing for sonic manipulation. PMID- 19875144 TI - Mechanisms and functional implications of the degradation of host RNA polymerase II in influenza virus infected cells. AB - Influenza viruses induce a host shut off mechanism leading to the general inhibition of host gene expression in infected cells. Here, we report that the large subunit of host RNA polymerase II (Pol II) is degraded in infected cells and propose that this degradation is mediated by the viral RNA polymerase that associates with Pol II. We detect increased ubiquitylation of Pol II in infected cells and upon the expression of the viral RNA polymerase suggesting that the proteasome pathway plays a role in Pol II degradation. Furthermore, we find that expression of the viral RNA polymerase results in the inhibition of Pol II transcription. We propose that Pol II inhibition and degradation in influenza virus infected cells could represent a viral strategy to evade host antiviral defense mechanisms. Our results also suggest a mechanism for the temporal regulation of viral mRNA synthesis. PMID- 19875145 TI - Influence of biofilm on the transport of fullerene (C60) nanoparticles in porous media. AB - The significance of biofilm on fullerene C(60) nanoparticles transport and deposition were examined both in porous media and quartz crystal microbalance with dissipation (QCM-D) systems under a variety of environmentally relevant ionic strength (1-25 mM in NaCl and 0.1-5 mM in CaCl(2)) and flow conditions (4-8 m day(-1)). The magnitudes of deposition rate coefficients (k(d)) were compared between porous media with and without biofilm extracellular polymeric substances (EPS) coating under equivalent fluid velocities and solution chemistries. The observed k(d) were greater in porous media with biofilm EPS coating relative to those without biofilm EPS coating across the entire solution ionic strengths and fluid velocities examined, demonstrating that the enhancement of C(60) deposition by the biofilm EPS coating is relevant to a wide range of environmental conditions. This greater deposition was also observed on silica surfaces with biofilm EPS coating in QCM-D system. The results clearly showed that biofilm EPS have a great influence on C(60) deposition. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory could not explain the enhanced C(60) deposition by biofilm EPS. Biochemical and physical characteristics of biofilm EPS were responsible for the increased C(60) deposition. PMID- 19875146 TI - PBDEs in indoor dust in South-Central China: characteristics and implications. AB - Dust samples were collected randomly from 76 houses, 12 offices, 43 outdoor sites, two televisions and two computers in South-Central China. The indoor dust samples were analyzed for the concentrations, congener profiles, and possible sources of polybrominated diphenyl ethers (PBDEs) and compared to similar data obtained for outdoor dusts. The concentrations of Sigma(10)PBDEs (the sum of BDE28, 47, 66, 85, 99, 100, 153, 154, 183, and 209) were 186.6-9654 ng g(-1) (mean=2662 ng g(-1)) and 1737-4408 ng g(-1) (mean=3179 ng g(-1)) for house dust and office dust, respectively. No significant differences were found among the congener profiles of PBDEs in house dust from three different cities. The dominant congener in all dust samples was BDE209, accounting for an average of 96.2%, 99.0% and 97.4% of Sigma(10)PBDEs for house dust, office dust and outdoor dust, respectively. Unlike previous studies, this study found that BDE183 was present in high proportion to Sigma(9)PBDEs (BDE209 excluded) in both indoor and outdoor dusts, in addition to the usually dominant congeners, BDE47 and 99. Sigma(10)PBDEs concentrations in house dust were higher than those in outdoor dust for most comparison samples. Combined with the significantly higher Sigma(10)PBDEs concentrations in television and computer dusts, PBDE-containing products used indoors, including television and computers, were important potential emission sources for PBDEs in indoor dusts. Further studies are required to detail the source of the high levels of BDE183 in Chinese indoor dusts. PMID- 19875147 TI - Transformation of the water soluble fraction from "alpeorujo" by Coriolopsis rigida: the role of laccase in the process and its impact on Azospirillum brasiliense survival. AB - The objective of this work was to evaluate the ability of the white rot basidiomycete Coriolopsis rigida to detoxify the water soluble fraction from "alpeorujo" (WSFA), a solid by-product produced by the olive oil extraction industry and characterized by a high concentration of phenols which limits its use as fertilizer and/or amendment. C. rigida reduced the phenol content in the liquid media supplemented with WSFA at 10 and 20% (v/v) after 15d of incubation. The analysis of WSFA toxicity after fungal treatment showed that C. rigida was responsible for a significant increase in the survival rate of Azospirillum brasiliense, a N(2) fixing soil rhizobacterium which promotes plant growth. Supplementation of culture medium with CuSO(4) (300 microM) resulted in strong laccase induction thus facilitating higher phenol reduction and detoxification of WSFA. In vitro reactions using a crude extracellular preparation from laccase active C. rigida showed phenol removal as well as detoxification of the WSFA at 20%. These results suggest that C. rigida reduces the phenol content of the WSFA through the effect of laccase on free phenolic compounds consequently decreasing the toxic effect on A. brasiliense, which suggests that the enzyme plays an important role in the process. These findings have implications in the management and revalorization of olive-mill residues treated with laccase-producing fungi and their potential impact on integrative agricultural systems including organic residues and the co-inoculation with microorganisms which can facilitate the growth of plants of agricultural interest. PMID- 19875149 TI - Testing hypotheses of dietary reconstruction from buccal dental microwear in Australopithecus afarensis. AB - A recent study of occlusal microwear in Australopithecus afarensis described this species as an opportunistic dweller, living in both forested and open environments and greatly relying on fallback resources and using fewer food processing activities than previously suggested. In the present study, analysis of buccal microwear variability in a sample of A. afarensis specimens (n=75 teeth) showed no significant correlations with the ecological shift that took place around 3.5Ma in Africa. These results are consistent with the occlusal microwear data available. In fact, significant correlations between buccal and occlusal microwear variables were found. However, comparison of the buccal microwear patterns showed clear similarities between A. afarensis and those hominoid species living in somewhat open environments, especially the Cameroon gorillas. A diet based mainly on succulent fruits and seasonal fallback resources would be consistent with the buccal microwear patterns observed. PMID- 19875148 TI - Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape. AB - Tufted capuchins (sensu lato) are renowned for their dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between C. apella (n=12) and two "untufted" capuchins (C. capucinus, n=3; C. albifrons, n=5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that tufted capuchins exhibit architectural properties of their jaw muscles that facilitate relatively large forces including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P(0)). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P(0). As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in tufted capuchins primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear to have increased jaw muscle and bite forces without markedly compromising muscle excursion and contraction velocity. One performance advantage of this morphology is that it promotes relatively large bite forces at wide jaw gapes, which may be useful for processing large food items along the posterior dentition. We further hypothesize that this morphological pattern may have the ecological benefit of facilitating the dietary diversity seen in tufted capuchins. Lastly, the observed feeding on large objects, coupled with a jaw-muscle architecture that facilitates this behavior, raises concerns about utilizing C. apella as an extant behavioral model for hominins that might have specialized on small objects in their diets. PMID- 19875150 TI - The presence of a large cercopithecine (cf. Theropithecus sp.) in the 'Ubeidiya formation (Early Pleistocene, Israel). AB - This study presents the discovery of a right cercopithecine calcaneus from the site of 'Ubeidiya, Israel, dated to ca. 1.6 Ma. The fossil is described and statistically compared to bones of modern and fossil cercopithecids. The specimen can be attributed to a large-bodied cercopithecine and represents a new primate taxon previously unidentified in the Early Pleistocene of the Southern Levant. Among extant genera, it is most clearly similar to calcanei of Theropithecus. However, it could also represent Paradolichopithecus, but this alternative is unlikely due to the morphological uniqueness of the latter taxon. The finding of an African taxon in the Levant suggests a circum-Mediterranean dispersal route for the taxon out of Africa, and emphasizes the importance of the Levantine corridor as a biogeographic dispersal route between Africa and Eurasia during the Early Pleistocene. Evidence for the biogeography of large-bodied primates is essential for the understanding of the dispersal routes of "Out of Africa I" taxa and can help elucidate Homo dispersal patterns in the Early Pleistocene. PMID- 19875151 TI - Inhalation method for delivery of nanoparticles to the Drosophila respiratory system for toxicity testing. AB - The growth of the nanotechnology industry and subsequent proliferation of nanoparticle types present the need to rapidly assess nanoparticle toxicity. We present a novel, simple and cost-effective nebulizer-based method to deliver nanoparticles to the Drosophila melanogaster respiratory system, for the purpose of toxicity testing. FluoSpheres, silver, and CdSe/ZnS nanoparticles of different sizes were effectively aerosolized, showing the system is capable of functioning with a wide range of nanoparticle types and sizes. Red fluorescent CdSe/ZnS nanoparticles were successfully delivered to the fly respiratory system, as visualized by fluorescent microscopy. Silver coated and uncoated nanoparticles were delivered in a toxicity test, and induced Hsp70 expression in flies, confirming the utility of this model in toxicity testing. This is the first method developed capable of such delivery, provides the advantage of the Drosophila health model, and can serve as a link between tissue culture and more expensive mammalian models in a tiered toxicity testing strategy. PMID- 19875152 TI - Concentrations and loads of suspended sediment-associated pesticides in the San Joaquin River, California and tributaries during storm events. AB - Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3,000 ng/g; median of 6.1 ng/g) were generally greater than those for the insecticides (0.2 to 51 ng/g; median of 1.5 ng/g). Concentrations in the tributaries were usually greater than in the mainstem San Joaquin River and the west side tributaries were higher than the east side tributaries. Estimated instantaneous loads ranged from 1.3 to 320 g/day for herbicides and 0.03 to 53 g/day for insecticides. The greatest instantaneous loads came from the Merced River on the east side. Instantaneous loads were greater for the first storm of 2008 than the second storm in the tributaries while the instantaneous loads within the San Joaquin River were greater during the second storm. Pesticide detections generally reflected pesticide application, but other factors such as physical-chemical properties and timing of application were also important to pesticide loads. PMID- 19875153 TI - A GIS-based method for modelling air pollution exposures across Europe. AB - A GIS-based moving window approach was developed as a means for generating high resolution air pollution maps over large geographic areas. The approach is demonstrated by modelling annual mean NO(2) pollution for the EU-15 (excluding Sweden) at the 1 km level on the basis of emissions and meteorological data. Models were developed using monitoring data from 714 background NO(2) sites for 2001 and validated by comparing predicted with observed NO(2) concentrations for a reserved set of 228 background sites. First the emission map (NO(x)) was derived by disaggregating national emissions estimates, categorised by source, to a 1 km grid, using proxies including population and road density, traffic statistics and land cover. A set of annuli was then constructed, of varying radii, and these passed over the emissions grid to derive a calibration between measured annual average concentrations at each monitoring site and distance weighted emissions in the surrounding area, using a focalsum function. The resulting model was then used to predict concentrations at the reserved set of validation sites, and measures of performance (R(2), RMSE and fractional bias) obtained. Validation gave R(2)=0.61, RMSE=6.59 and FB=-0.01, and indicated performance equivalent to universal kriging and better than ordinary kriging and land use regression. PMID- 19875154 TI - Forecasting risk along a river basin using a probabilistic and deterministic model for environmental risk assessment of effluents through ecotoxicological evaluation and GIS. AB - This work presents a computer model for Risk Assessment of Basins by Ecotoxicological Evaluation (RABETOX). The model is based on whole effluent toxicity testing and water flows along a specific river basin. It is capable of estimating the risk along a river segment using deterministic and probabilistic approaches. The Henares River Basin was selected as a case study to demonstrate the importance of seasonal hydrological variations in Mediterranean regions. As model inputs, two different ecotoxicity tests (the miniaturized Daphnia magna acute test and the D.magna feeding test) were performed on grab samples from 5 waste water treatment plant effluents. Also used as model inputs were flow data from the past 25 years, water velocity measurements and precise distance measurements using Geographical Information Systems (GIS). The model was implemented into a spreadsheet and the results were interpreted and represented using GIS in order to facilitate risk communication. To better understand the bioassays results, the effluents were screened through SPME-GC/MS analysis. The deterministic model, performed each month during one calendar year, showed a significant seasonal variation of risk while revealing that September represents the worst-case scenario with values up to 950 Risk Units. This classifies the entire area of study for the month of September as "sublethal significant risk for standard species". The probabilistic approach using Monte Carlo analysis was performed on 7 different forecast points distributed along the Henares River. A 0% probability of finding "low risk" was found at all forecast points with a more than 50% probability of finding "potential risk for sensitive species". The values obtained through both the deterministic and probabilistic approximations reveal the presence of certain substances, which might be causing sublethal effects in the aquatic species present in the Henares River. PMID- 19875155 TI - Influence of sex, maturity and reproduction on PCB and p,p'DDE concentrations and repartitions in the European hake (Merluccius merluccius, L.) from the Gulf of Lions (N.W. Mediterranean). AB - The main objective of this work was to establish the influence of sex, maturity and reproduction on the contamination of the demersal fish Merluccius merluccius by organochlorine compounds. Polychlorinated biphenyls (PCBs) and p,p'DDE were quantified in muscle, liver and gonads of female and male hakes collected in the Gulf of Lions in 2004 and 2005. Observed levels appeared higher than the population of the Bay of Biscay and lower than the population of the Thyrrenian Sea. Contaminant fingerprints were roughly constant whatever the studied organ and the hake biological condition. Concentrations varied significantly according to the sex and maturity of hakes. Mature specimens were more contaminated than immature, and males presented higher levels than females. This sex effect can be linked to a lower growth rate of males, and a contaminant elimination during female spawning. Gonadal contamination depends on the importance of lipid content and increases with the maturation degree. Although the main organ of energy and PCB storage is the liver, muscle appears as the main contributor to the gonad contamination. PMID- 19875156 TI - Ambient air total gaseous mercury concentrations in the vicinity of coal-fired power plants in Alberta, Canada. AB - The Lake Wabamun area, in Alberta, is unique within Canada as there are four coal fired power plants within a 500 km(2) area. Continuous monitoring of ambient total gaseous mercury (TGM) concentrations in the Lake Wabamun area was undertaken at two sites, Genesee and Meadows. The data were analyzed in order to characterise the effect of the coal-fired power plants on the regional TGM. Mean concentrations of 1.57 ng/m(3) for Genesee and 1.50 ng/m(3) for Meadows were comparable to other Canadian sites. Maximum concentrations of 9.50 ng/m(3) and 4.43 ng/m(3) were comparable to maxima recorded at Canadian sites influenced by anthropogenic sources. The Genesee site was directly affected by the coal-fired power plants with the occurrence of northwest winds, and this was evident by episodes of elevated TGM, NO(x) and SO(2) concentrations. NO(x)/TGM and SO(2)/TGM ratios of 21.71 and 19.98 microg/ng, respectively, were characteristic of the episodic events from the northwest wind direction. AERMOD modeling predicted that coal-fired power plant TGM emissions under normal operating conditions can influence hourly ground-level concentrations by 0.46-1.19 ng/m(3)(.) The effect of changes in coal-fired power plant electricity production on the ambient TGM concentrations was also investigated, and was useful in describing some of the episodes. PMID- 19875157 TI - WITHDRAWN: Retinal vein occlusion: Risk factors evaluation, treatment and prophylaxis. AB - This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy. PMID- 19875158 TI - Stage I, grade 3 endometrioid adenocarcinoma of the endometrium: an analysis of clinical outcomes and patterns of recurrence. AB - OBJECTIVE: To study patterns of recurrence and survival outcomes in patients with surgical stage I, grade 3 endometrioid adenocarcinoma of the endometrium (EA) treated with various treatment modalities. METHODS: A retrospective multi institutional study of surgical stage I, grade 3 EA patients diagnosed between 1988 and 2006 was performed. Demographic, clinicopathologic, treatment and outcome data were collected. After surgery, patients were treated with either observation or radiotherapy (vaginal brachytherapy, whole pelvic or both). RESULTS: One hundred seventy-six patients were collected with a median age of 68 years. Twenty-six (15%) were stage IA, 96 (54%) IB and 54 (31%) IC. Sixty-one patients (35%) had lymphovascular space invasion (LVSI) and a mean of 18.9 lymph nodes (LNs) was removed. Seventy-eight patients (44%) were observed while 98 (56%) were treated with radiotherapy, the majority (n=51) receiving brachytherapy. After a median follow-up of 58 months, 20 recurrences (11%) were noted. Ninety percent of recurrences occurred in Stage IB/IC patients. The median time to recurrence was 22.5 months (5-74.5) and 80% of recurrences were extra pelvic. There was no significant difference in recurrence based upon treatment modality or LVSI. Majority of recurrences were not salvaged as 75% (12/16) died of their disease with a median time of recurrence to death of 8 months. CONCLUSIONS: Patients with stage IB/IC, grade 3 endometrioid adenocarcinoma have a significant risk for extra-pelvic recurrence. Most patients will not be salvaged and will succumb to their disease, suggesting that current loco-regional adjuvant treatment strategies are not optimal and evaluation of more systemic therapies is warranted. PMID- 19875160 TI - Suberoylanilide hydroxamic acid (SAHA) potentiates paclitaxel-induced apoptosis in ovarian cancer cell lines. AB - OBJECTIVES: To determine if SAHA, a histone deacetylase inhibitor, decreases ovarian cancer cell viability when combined with paclitaxel in vitro, and to explore molecular alterations of combined paclitaxel+SAHA treatment. METHODS: SKOV3 and Hey ovarian cancer cell lines were treated for 24 h with paclitaxel, then re-treated with SAHA or paclitaxel for an additional 48 h. Protein extracts were prepared at 48 h for western blot analysis. Cell viability was assessed at 72 h using the ApoAlert Annexin V Apoptosis Kit. RESULTS: SAHA causes G1 and G2 cell cycle arrest in ovarian cancer cell lines. Cell viability was significantly reduced by combined paclitaxel+SAHA treatment. In Hey cells, viability was reduced to 67% with paclitaxel, and to 48% with paclitaxel+SAHA (p<0.001). In the SKOV3 cell line, viability was reduced to 70% with continuous paclitaxel treatment, and was further reduced to 57% in the combined treatment group (p<0.05). Increased PARP cleavage was noted in the paclitaxel+SAHA groups. SAHA increased expression of p21cip1/waf1 and p27Kip1, down regulated cyclins A and B, and suppressed CDK1. Paclitaxel induced expression of survivin, an inhibitor of apoptosis protein, was reduced to baseline control levels with the addition of SAHA. The pro-apoptotic protein, Bad, was also increased with SAHA. CONCLUSIONS: Paclitaxel+SAHA reduces cell viability in excess of either agent alone in ovarian cancer cell lines. Cell death is mediated via several mechanisms including G1/G2 arrest from CDK1 downregulation, inhibition of paclitaxel-induced survivin accumulation, and from increased Bad expression. PMID- 19875159 TI - Evaluation of magnetic resonance diffusion and spectroscopy measurements as predictive biomarkers in stage 1 cervical cancer. AB - OBJECTIVE: To establish whether ADC and total choline were significantly different between cervical tumors with different histological characteristics (type, degree of differentiation, presence or absence of lymphovascular invasion, lymph-node involvement) in order to establish their role as predictive biomarkers. METHODS: 62 patients with stage 1 cervical cancer were scanned at 1.5 T. T2-weighted imaging (TR/TE=4500/80 ms), to identify tumor and normal cervix, was followed by diffusion-weighted imaging (TR/TE=2500/69 ms; 5 b-values 0, 100, 300, 500 and 800 s/mm(2)) and MR spectroscopic imaging (15 mm slice, 7.5 mm in plane resolution, TR=888 ms). Regions of interest in normal cervix and tumor were drawn on apparent diffusion coefficient (ADC) maps by an expert observer with reference to the T2-weighted images. ADCs were calculated using a monoexponential fit of data from all b-values. MR spectra in voxels designated as tumor (>30% tumor) or non-tumor were quantified using LCModel and referenced to tissue water. RESULTS: There was a statistically significant difference between the ADC of tumor regions (1117+/-183x10(-6) mm(2)/s) and of selected normal regions (1724+/ 198x10(-6) mm(2)/s; p<0.001), and between tumors that were well/moderately differentiated (1196+/-181x10(-6) mm(2)/s) compared with those that were poorly differentiated (1038+/-153x10(-6) mm(2)/s; p=0.016). There was no significant difference between the ADCs of the tumors when separated by other characteristics (tumor type, lymphovascular invasion, lymph-node metastases), or between measured total choline in any of the groups. CONCLUSION: ADCs are lower in cancer compared to normal cervical tissue, with degree of tumor differentiation contributing to this difference. PMID- 19875161 TI - Sentinel lymph node biopsy vs. pelvic lymphadenectomy in early stage cervical cancer: is it time to change the gold standard? AB - OBJECTIVE: To compare the incidence of pelvic lymph node metastases in early stage cervical cancer patients undergoing sentinel lymph node biopsy (SLN) to a matched cohort undergoing pelvic lymphadenectomy. METHODS: All patient data were entered prospectively into an ongoing cervical cancer database. Since April 2004, 87 patients with FIGO stage IA/B1 cervical cancer underwent SLN detection with identification of bilateral SLN. This cohort (cases) was compared to a matched group of patients who underwent complete pelvic lymphadenectomy (controls). The groups were matched 3:1 for tumour size (+/-5 mm), histology, depth of invasion (+/-2 mm), and presence of capillary lymphatic space invasion (CLS). Descriptive statistics were calculated for all variables of interest. The association between cases and controls and lymph node metastases was carried out using a conditional logistic regression analysis. RESULTS: 81 women in the SLN cohort were matched with 1 control, 72 cases with 2 controls, and 65 cases with 3 controls. Among cases, 14 (17%) had pelvic lymph nodes metastases vs. 15 (7%) in the controls (p=0.0059, odds ratio= 2.8, 95% CI=1.3-5.9). Among the 14 cases of SLN metastases, 11 were detected by frozen section and 3 were detected on final paraffin sectioning. All were detected by H and E stains. The size of the SLN metastases ranged from less than 1 mm to 8 mm. CONCLUSIONS: Sentinel lymph node biopsy in early cervical cancer is a more sensitive procedure in detecting pelvic lymph node metastases compared to complete lymphadenectomy. PMID- 19875162 TI - Expression of prostaglandin E synthases in the bovine oviduct. AB - The oviduct is a specialized organ responsible for the storage and the transport of male and female gametes. It also provides an optimal environment for final gamete maturation, fertilization, and early embryo development. Prostaglandin (PG) E(2) is involved in many female reproductive functions, including ovulation, fertilization, implantation, and parturition. However, the control of its synthesis in the oviduct is not fully understood. Cyclooxygenases (COXs) are involved in the first step of the transformation of arachidonic acid to PGH(2.) The prostaglandin E synthases (PGESs) constitute a family of enzymes that catalyze the conversion of PGH(2) to PGE(2), the terminal step in the formation of this bioactive prostaglandin. Quantitative real-time PCR was used to determine the expression of COX-1, COX-2, microsomal prostaglandin E synthase-1 (mPGES-1), microsomal prostaglandin E synthase-2 (mPGES-2), and cytosolic prostaglandin E synthase (cPGES) mRNA in various sections of the oviduct, both ipsilateral and contralateral (to the ovary on which ovulation occurred) at various stages of the estrous cycle. Furthermore, protein expression and localization of cPGES, mPGES 1, and mPGES-2 were determined by Western blot and immunohistochemistry. All three PGESs were detected at both mRNA and protein levels in the oviduct. These PGESs were mostly concentrated in the oviductal epithelial layer and primarily expressed in the ampulla section of the oviduct and to a lesser extent in the isthmus and the isthmic-ampullary junction. The mPGES-1 protein was highly expressed in the contralateral oviduct, which contrasted with mPGES-2 mostly expressed in the ipsilateral oviduct. This is apparently the first report documenting that the three PGESs involved in PGE(2) production were present in the Bos taurus oviduct. PMID- 19875163 TI - Adjustment of dosing of antimicrobial agents for bodyweight in adults. PMID- 19875164 TI - Diabetes in Asia. AB - Prevalence of type 2 diabetes has rapidly increased in native and migrant Asian populations. Diabetes develops at a younger age in Asian populations than in white populations, hence the morbidity and mortality associated with the disease and its complications are also common in young Asian people. The young age of these populations and the high rates of cardiovascular risk factors seen in Asian people substantially increase lifetime risk of cardiovascular disease. Several distinctive features are apparent in pathogenetic factors for diabetes and their thresholds in Asian populations. The economic burden due to diabetes at personal, societal, and national levels is huge. National strategies to raise public awareness about the disease and to improve standard of care and implementation of programmes for primary prevention are urgently needed. PMID- 19875165 TI - Fatigue-life assessment and validation techniques for metallic vascular implants. AB - Vascular implants, such as cardiac valve prostheses, stents, and other devices are often subjected to complex loading conditions in vivo, which can include pulsatile pressure cycling, bending, torsion, tension, and compression, among others. At an average of 72 heartbeats per minute, pulsatile loading alone produces approximately 40-million cycles per year. With design lives of 10-15 years, fatigue performance assessment and validation of these devices are critical for the designer, as mechanical failure can have serious consequences. Historically, various fatigue life assessment approaches have been used to validate endovascular device fatigue performance, including durability testing, stress/strain-life analysis, and damage tolerance-based analysis. This paper explores the merits and shortcomings of each of these design approaches, and provides recommendations for fatigue-life validation of endovascular implants. PMID- 19875166 TI - Non-linear and gender-specific relationships among placental growth measures and the fetoplacental weight ratio. AB - GOALS: Fetal growth depends on placental growth; the fetoplacental weight ratio (FPR) is a common proxy for the balance between fetal and placental growth. Male and female infants are known to have differing vulnerabilities in fetal life, during parturition and in infancy. We hypothesized that these differences may be paralleled by differences in how birth weight (BW) and the fetoplacental weight ratio (FPR) are affected by changes in placental proportions. MATERIALS AND METHODS: Placental proportion measures (disk shape, larger and smaller chorionic diameters, chorionic plate area calculated as the area of an ellipse with the 2 given diameters, disk thickness, cord eccentricity and cord length) were available for 24,601 participants in the Collaborative Perinatal Project delivered between >34 and <43 completed weeks. The variables were standardized and entered into multiple automated regression splines (MARS 2.0, Salford Systems, Vista CA) to identify nonlinearities in the relationships of placental growth measures to BW and FPR with results compared for male and female infants. RESULTS: Changes in chorionic plate growth in female compared to male infants resulted in a greater change in BW and FPR. The positive effects of umbilical cord length on BW reversed at the mean umbilical cord length in females and at +0.08 SD in male infants. CONCLUSIONS: Female infants' BW and FPR are each more responsive to changes in placental chorionic plate growth dimensions than males; this may account for greater female resilience (and greater male vulnerability) to gestational stressors. The effect of umbilical cord length on FPR may be due to longer cords carrying greater fetal vascular resistance. Again male fetuses show a higher "threshold" to the negative effects of longer cords on FPR. PMID- 19875167 TI - Multiple lipoma with hyperlipidemia in a multiple myeloma patient treated with bortezomib/dexamethazone. PMID- 19875168 TI - mRNA expression of matrix metalloproteinases (MMPs) 2 and 9 and tissue inhibitor of matrix metalloproteinases (TIMPs) 1 and 2 in childhood acute lymphoblastic leukemia: potential role of TIMP1 as an adverse prognostic factor. AB - This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P=0.04) and multivariable analysis (P=0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL. PMID- 19875169 TI - SHP-1 exhibits a pro-apoptotic function in antigen-stimulated mast cells: positive regulation of mitochondrial death pathways and negative regulation of survival signaling pathways. AB - Src homology region 2 domain-containing phosphatase-1 (SHP-1) is known to act as a negative signal modulator in mast cells but its roles in cell survival and cell death are poorly understood. We previously reported that SHP-1 also positively regulates mast cell activation signaling by acting as an adaptor protein. In the present study, we examined whether SHP-1 plays a role in antigen (Ag)-induced activation-induced mast cell death. Bone marrow-derived mast cells (BMMCs) from SHP-1-deficient motheaten (me) mice (me-BMMCs) were significantly less susceptible to store-operated Ca(2+) channel (SOC) activation, Ag-induced cell death and DNA fragmentation than BMMCs from their wild-type littermates (WT BMMCs). Subsequent experiments revealed that the differences in these cellular susceptibilities to SOC activation and cell death resulted from the extent of the mitochondrial permeability transition pore (mPTP) opening. Specifically, mPTP opening was sufficiently persistent in WT-BMMCs to evoke mitochondrial integrity disruption, while mPTP opening was too transient to cause the minimal mitochondrial integrity collapse in me-BMMCs. In addition, pro-survival signaling including activation of mitogen-activated protein kinases (MAPKs) such as the extracellular signal-regulated protein kinases, c-Jun NH(2) terminal kinases and p38 and the expression of Bcl-x(L) were significantly prolonged in me-BMMCs compared with WT-BMMCs. Taken together, these data demonstrate that a lack of SHP 1 prevents the mPTP-mediated mitochondrial integrity collapse and augments anti apoptotic signaling such as MAPKs and Bcl-x(L). These findings suggest that SHP-1 positively regulates mitochondrial death pathways and negatively regulates pro survival signaling pathways. PMID- 19875170 TI - Descemet's membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival. AB - PURPOSE: To describe Descemet's membrane endothelial keratoplasty (DMEK) techniques, perioperative challenges, management, and visual and refractive outcomes. DESIGN: Prospective, multicenter, consecutive case series. PARTICIPANTS: Sixty eyes of 56 patients with Fuchs' endothelial dystrophy, pseudophakic bullous keratopathy, or failed previous graft. INTERVENTION: Descemet's membrane (DM) and endothelium were stripped from donor corneas submerged in corneal storage solution in a corneal viewing chamber. Donor DM diameters were 8.5 or 9.0 mm. The central 7 mm of DM was stripped from the recipient cornea. After staining with trypan blue to improve visualization, donor DM was inserted through a 2.8-mm incision. Descemet's membrane endothelial keratoplasty was performed alone (n = 48) or was combined with phacoemulsification and lens implantation (n = 11), pars plana vitrectomy (n = 2), or both. MAIN OUTCOME MEASURES: Best spectacle-corrected visual acuity (BSCVA), manifest refraction, and endothelial cell density. RESULTS: Median BSCVA was 20/30 at 1 month (range, 20/20-20/60), improving from 20/50 (range, 20/25 hand movements) before DMEK, excluding 4 eyes (7%) with preexisting ocular pathologic features that limited visual potential. At 3 months, 26% had 20/20 vision, 63% saw 20/25 or better, and 94% saw 20/40 or better. Refractive cylinder remained unchanged at 0.9 diopters (D; P = 0.93), and a hyperopic shift of 0.49+/ 0.63 D (P = 0.0091) was noted in DMEK single procedures. Endothelial cell loss was 30%+/-20% at 3 months and 32%+/-20% in 38 eyes that reached the 6-month examination. Median pachymetry decreased from 660 mum before surgery to 530 mum. Descemet's membrane stripped successfully from 60 of 72 donor corneas; 6 were converted successfully to Descemet's stripping automated endothelial keratoplasty (DSAEK) and 6 (8%) were discarded. Only 1 graft detached completely, but air was reinjected in 38 eyes (63%), mainly for partial detachments. Five DMEK corneas (8%) failed to clear and were replaced successfully with DMEK or DSAEK. All remained clear at last follow-up. CONCLUSIONS: Compared with DSAEK, DMEK provided a significantly higher rate of 20/20 and 20/25 vision, with comparable endothelial cell loss. Descemet's membrane endothelial keratoplasty restored physiologic pachymetry, but donor preparation and attachment currently are more challenging than with DSAEK. PMID- 19875171 TI - Double lacrimal puncta: clinical presentation and potential mechanisms of epiphora. AB - PURPOSE: Congenital supernumerary lacrimal puncta and canaliculi are rarely reported. Our purpose is to present the largest series of patients with supernumerary puncta and to describe the clinical presentation and associated lacrimal anomalies. DESIGN: Observational retrospective case series. PARTICIPANTS: All patients diagnosed with supernumerary puncta by a single surgeon between 1988 and 2008. METHODS: Retrospective case note review. MAIN OUTCOME MEASURES: Patient demographics, clinical presentation, lacrimal and systemic examination findings, management, and surgical outcomes. RESULTS: Twenty three patients (12 female, 11 male) with a median presenting age of 54 years (range, 1-88 years) had unilateral double lower lid puncta. In 5 patients the presence of a double punctum was an incidental examination finding. Eighteen patients had unilateral tearing on the same side as the double punctum. In 6 children presenting with tearing, associated congenital lacrimal anomalies included nasolacrimal duct obstruction, a lacrimal fistula, a lacrimal sac diverticulum, and absence of the upper canaliculus. Associated systemic findings in 3 children included Down syndrome (1 patient) and preauricular sinuses (2 patients). Of 12 adult patients presenting with ipsilateral tearing, 5 had complete nasolacrimal duct obstruction and 6 had either partial nasolacrimal duct obstruction or functional epiphora. Dacryocystorhinostomy was performed in 12 patients and resulted in improvement or resolution of symptoms in 11 patients (92%). CONCLUSIONS: Double lower lacrimal puncta may be associated with epiphora. In younger patients, tearing may be due to associated congenital anomalies of the nasolacrimal system. A proportion of patients presenting with onset of tearing in adulthood have patent lacrimal systems and otherwise normal adnexal examination results, suggesting that the presence of double puncta may be associated with compromised canalicular function. Reflux of tears through the accessory canaliculus is a potential mechanism and would be consistent with a recently proposed 2-compartment model of lacrimal canalicular drainage. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article. PMID- 19875172 TI - Anterior chamber depth is significantly decreased after scleral buckling surgery. AB - OBJECTIVE: Myopic patients have an increased risk for the development of a rhegmatogenous retinal detachment (RRD). Currently, myopic patients have the choice to undergo correction of their refractive error by the implantation of a phakic intraocular lens (pIOL). After pIOL implantation, progressive endothelial cell loss may result if the anterior chamber is too shallow. Because scleral buckling (SB) surgery for treatment of an RRD may in itself result in a decreased anterior chamber depth (ACD), this may become an important issue not only for the retinal surgeon who is faced with a patient who has both an RRD and a pIOL, but also for the refractive surgeon who should consider the potential problems of the implantation of pIOL in an eye that has previously undergone SB surgery. The goal of this study was to evaluate how long changes in ACD persist after SB procedures in patients with RRD. DESIGN: Prospective case series. PARTICIPANTS: Thirty-eight eyes with a primary RRD treated by SB using an encircling element and a radial or segmental buckle; 31 fellow eyes served as controls. METHODS: Anterior chamber depth (in the horizontal meridian) and axial length were measured preoperatively and at 1 week and 1, 3, 6, 9, and 12 months postoperatively with an anterior optical coherence tomography method and an IOLMaster (Carl Zeiss Meditec, Jena, Germany), respectively. MAIN OUTCOME MEASURES: In all 38 eyes, ACD was significantly reduced compared with preoperative levels up to 9 months after SB surgery. RESULTS: Anterior chamber depth returned to normal at 1 year after surgery. Axial length was significantly enlarged during the whole follow-up period. No significant differences were found between the use of radial or segmental buckles. CONCLUSIONS: Anterior chamber depth may remain decreased after SB for a longer time period than previously reported. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article. PMID- 19875173 TI - A randomized controlled trial comparing everting sutures with everting sutures and a lateral tarsal strip for involutional entropion. AB - OBJECTIVE: To determine whether there is a statistically significant difference in the surgical outcome of everting sutures (ES) alone versus everting sutures with a lateral tarsal strip (ES+LTS) in the treatment of involutional entropion. DESIGN: Prospective randomized comparative trial. PARTICIPANTS: Sixty-three patients with primary involutional lower eyelid entropion were enrolled in the study. The age range was 54 to 94 years, with a mean age of 77 years. Baseline characteristics of the comparative groups were similar. METHODS: Patients requiring primary surgical repair for involutional entropion were selected, and those providing informed consent were randomized for surgery. Thirty-six patients were randomized to ES alone, and 27 patients were randomized to ES+LTS. Patients were evaluated at 3 weeks and 6, 12, and 18 months postoperatively. MAIN OUTCOME MEASURES: Successful surgery was defined as a normal eyelid position at rest and inability to induce entropion on tetracaine provocation testing at or before the 18-month follow-up visit. RESULTS: Eight patients were lost to follow-up (7 had ES alone). Of the 55 patients with complete follow-up data, there were 6 failed procedures in the patients who underwent ES alone and no failed procedures in the patients who underwent ES+LTS (P = 0.02). CONCLUSIONS: These data provide strong evidence that success rates at 18 months are higher in patients treated with ES+LTS procedure compared with ES alone. PMID- 19875174 TI - Accumulation of Eu3+ chelates in cells expressing or not P-glycoprotein: implications for blood-brain barrier crossing. AB - Alzheimer's disease (AD) is the most commonly form of dementia in the elderly. The development of molecules able to detect biomarkers characteristic of AD is critical to its understanding and treatment. However, such molecules must be able to pass blood-brain barrier (BBB) which is a major impediment to the entry of many therapeutic drugs into the brain. Such a limitation applies to the development of magnetic resonance imaging molecular neuroimaging agents using biomarkers of AD-like beta-amyloid deposits, as the common extracellular contrast agents (CAs) are not able to cross an intact BBB. In this work, we have studied the ability of a series of simple Eu(3+) complexes to enter cells overexpressing or not the ABCB1 (P-gp or P-glycoprotein) protein, which is expressed at the BBB and in human embryonic astrocytes. The intracellular uptake of the Eu(3+) complexes of linear and macrocyclic polyaminocarboxylate ligands with different charges and lipophilicities was followed by atomic absorption spectrometry. Based on biochemical argument, we propose that lipophilic contrast agents can be efficiently taken up by cells and accumulate inside mitochondria when they are positively charged. The important point is that they are not P-gp substrates, which is one of the major obstacles for them to cross the BBB. PMID- 19875175 TI - Stabilization of Mn(II) and Mn(III) in mononuclear complexes derived from tridentate ligands with N2O donors: synthesis, crystal structure, superoxide dismutase activity and DNA interaction studies. AB - A new family of tridentate ligands PhimpH (2-((2-phenyl-2-(pyridin-2 yl)hydazono)methyl)phenol), N-PhimpH (2-((2-phenyl-2-(pyridin-2 yl)hydrazono)methyl)napthalen-1-ol), Me-PhimpH (2-(1-(2-phenyl-2-(pyridine-2 yl)hydrazono)ethyl)phenol) have been synthesized and characterized. The ligands PhimpH and N-PhimpH after deprotonation react with manganese(II) and manganese(III) starting materials affording [Mn(Phimp)(2)] (1), [Mn(Phimp)(2)](ClO(4)) (2), [Mn(N-Phimp)(2)] (3), [Mn(N-Phimp)(2)](ClO(4)) (4). Complexes [Mn(Phimp)(2)] (1) and [Mn(N-Phimp)(2)] (3) convert to [Mn(Phimp)(2)](+) (cation of 2) and [Mn(N-Phimp)(2)](+) (cation of 4) respectively upon oxidation. Ligand Me-PhimpH stabilized only manganese(III) centre resulting [Mn(Me-Phimp)(2)](ClO(4)) (5). The molecular structures of [Mn(Phimp)(2)], 1 and [Mn(Phimp)(2)](ClO(4)), 2 were determined by single crystal X-ray diffraction. X-ray crystal structures of 1 and 2 have revealed the presence of distorted octahedral MnN(4)O(2) coordination sphere having meridionally spanning ligands. Electrochemical studies for the complexes showed Mn(II)/Mn(III), (E(1/2)=0.14-0.40V) and Mn(III)/Mn(IV), (E(1/2)=0.80-1.06V) couples vs. Ag/AgCl. The redox properties were exploited to examine superoxide dismutase (SOD) activity using Mn(II)/Mn(III) couple. The complexes 1, 2, 4 and 5 have been revealed to catalyze effectively the dismutation of superoxide (O(2)(. )) in xanthine-xanthine oxidase-nitro blue tetrazolium assay and IC(50) values were found to be 0.29, 0.39, 1.12 and 0.76 microM respectively. DNA interaction studies with complex 2 showed binding of DNA in a non-intercalative pathway. Complexes 1, 2 and 4 exhibited nuclease activity in presence of H(2)O(2) and inhibition of activity was noted in presence of KI. PMID- 19875176 TI - Functional aspects of CD52 in reproduction. AB - CD52 is a GPI-anchored protein present in lymphocytes and male reproductive tissues (mrt) including mature sperm and seminal plasma. It has been shown that mrt-CD52 is synthesized in epithelial cells of the epididymis and vas deferens, but not in the testis. The mrt-CD52 is transported to mature sperm during sperm transition in the male reproductive tract. Lymphocyte CD52 functions to stimulate suppressor T cell induction, while mrt-CD52 is associated with seminogelin and involved in clot formation and liquefaction of semen. In a landmark study, a monoclonal antibody (Mab H6-3C4) from peripheral B lymphocytes of a patient with complement-dependent sperm-immobilizing antibody in the serum has been generated. Using Mab H6-3C4, the carbohydrate moiety of CD52 as an epitope for infertility related antigen was identified. Mab H6-3C4 also shows strong complement-dependent sperm-immobilizing activity. This suggests CD52 may have a function in protecting sperm from complement activation. Indeed, purified mrt-CD52 from human sperm interferes with the classical pathway, but not lectin-binding or alternative pathways, of the complement systems. Recently, we found CD52 in ovulated cumulus cells from the female reproductive tissues (frt). The frt-CD52 is not recognized by Mab H6-3C4, suggesting that it harbors distinct carbohydrate antigenicity. Further studies are necessary to determine the molecular features and biological functions of CD52 in male and female reproductive tissues. PMID- 19875177 TI - The multifunctional zona pellucida and mammalian fertilization. AB - An early step in mammalian fertilization is species-restricted binding of sperm to the oocyte's zona pellucida (ZP), a thick extracellular coat. Sperm bind to the ZP of unfertilized oocytes, but not to the ZP of fertilized oocytes. Shortly after binding to the unfertilized oocyte ZP, sperm undergo the acrosome reaction (AR). Three mouse ZP glycoproteins, called mZP1-3, constitute the mouse oocyte's ZP and participate in the process of fertilization. For example, sperm exposed to unfertilized oocyte mZP3 at nanomolar concentrations are inhibited from binding to oocytes and undergo the AR; mZP1 and mZP2 have no effect. mZP3 from fertilized oocytes has no effect on sperm binding and is unable to induce the AR. These properties of mZP3 strongly suggest that it is a receptor for sperm and inducer of the AR. Mapping of the mZP3 combining-site for sperm suggests that it is located near the C-terminus of the polypeptide, in a region encoded by exon-7 of the mZP3 gene. This region of mZP3 is a site of positive Darwinian selection. When mZP3 exon-7 is fused to the Fc fragment of human IgG and sperm are exposed to the chimeric protein, the sperm are inhibited from binding to oocytes, suggesting that the inhibitory activity of mZP3 is dependent on this region of its polypeptide. PMID- 19875178 TI - Activating T regulatory cells for tolerance in early pregnancy - the contribution of seminal fluid. AB - A state of active tolerance mediated by T regulatory (Treg) cells must be functional from the time of embryo implantation to prevent the conceptus from maternal immune attack. Male seminal fluid and ovarian steroid hormones are implicated in regulating the size and suppressive function of the Treg cell pool during the peri-implantation phase of early pregnancy. Evidence that antigens and cytokine signals in seminal fluid regulate the maternal immune response includes the following: (1) the Treg cell-inducing cytokine TGFbeta and male alloantigens are present in seminal fluid; (2) seminal fluid delivery at coitus is sufficient to induce a state of active immune tolerance to paternal alloantigen, even in the absence of conceptus tissue; (3) female dendritic cells can cross-present seminal fluid antigens to activate both CD8(+) and CD4(+) T cells, and (4) mating events deficient in either sperm or seminal plasma result in diminished CD4(+) CD25(+) Foxp3(+) Treg cell populations at the time of embryo implantation. Ongoing studies indicate that the cytokine environment during priming to male seminal fluid antigens influences the phenotype of responding T cells, and impacts fetal survival in later gestation. Collectively, these observations implicate factors in the peri-conceptual environment of both male and female origin as important determinants of maternal immune tolerance. Defining the mechanisms controlling tolerance induction will be helpful for developing new therapies for immune mediated pathologies of pregnancy such as miscarriage and pre-eclampsia. PMID- 19875179 TI - Neutrophils contain prolyl endopeptidase and generate the chemotactic peptide, PGP, from collagen. AB - Prolyl endopeptidase (PE), a protease that cleaves after proline residues in oligopeptides, is highly active in brain and degrades neuropeptides in vitro. We have recently demonstrated that PE, in concert with MMP's, can generate PGP (proline-glycine-proline), a novel, neutrophil chemoattractant, from collagen. In this study, we demonstrate that human peripheral blood neutrophils contain PE, which is constitutively active, and can generate PGP de novo from collagen after activation with LPS. This novel, pro-inflammatory role for PE raises the possibility of a self-sustaining pathway of neutrophilic inflammation and may provide biomarkers and therapeutic targets for diseases caused by chronic, neutrophilic inflammation. PMID- 19875180 TI - Parents' views on the quality of life of their children 2-3 years after cochlear implantation. AB - OBJECTIVE: Cochlear implants for children are known to have impact on the lives of recipients and their families in a variety of ways. To obtain a clearer picture of these benefits, we explored the quality of life of 36 Finnish children and their families 2-3 years after unilateral cochlear implantation. METHODS: The studied children were, on average 5 years old, and had received their implant at the median age of 2 years:5 months (range 1:6 to 12:3). Most (67%) of the children used speech, eight (22%) used speech and signs, and four (11%) used sign language as their main communication mode. A third of the children had concomitant problems in addition to their profound hearing impairment. A validated closed-set questionnaire "Children with cochlear implants: parental perspectives" (available, e.g., at http://www.earfoundation.org.uk/research/questionnaires.html) was used to find out parents' views and experiences on implantation and explore life after it. RESULTS: Parents were most satisfied with improved/expanded social relations, improved communication (the development of spoken language), general functioning with the help of hearing and improved self-reliance of the child. Benefit of cochlear implantation was also detected with the Categories of Auditory Performance (CAP), which was concordant with views of the parents on the progress of their child in the areas of communication and education. When deciding on implantation, the parents particularly expected auditory information to enhance their child's safety in traffic, joining socially the hearing world, and better employment prospects as adults. Concerning the process of implantation, parents especially valued the know-how and fluent services of the implant centre, positive attitude within the family and information received from other families during the time they were considering the implant decision. Parents also found it important that they have the possibility to influence the communication mode that is used in their child's educational setting. CONCLUSIONS: Parents report that cochlear implants affect their children in a wide variety of ways that cannot be summarized by a single scale. A broader descriptive framework is required to capture their experiences adequately. PMID- 19875181 TI - Is Carhart notch an accurate predictor of otitis media with effusion? AB - BACKGROUND: In the era of pediatric otolaryngology, a number of different methods have been used for the diagnosis of otitis media with effusion (OME). Although there are divers articles within the filed of assessment of the accuracy of diagnostic methods of OME, surprisingly there are very few data published and a small number of researches explaining the accuracy of Carhart notch (CN) for diagnosis of OME cases and comparing the CN with abnormal tympanic membrane findings in binocular microtympanoscopy. METHODS: Audiometric parameters studied in 89 children (178 ears) suffering from chronic otitis media with effusion. Significant CN was defined as a minimum depression of 10 dB in comparison of the rest of thresholds, at any frequency from 500 to 4000 Hz. Intra-operative microscopic otoscopic findings and the type of middle ear fluid were documented in a specially formatted questionnaire. RESULTS: The incidence of CN was 44.94% (80 ears) and that of significant CN was 25.28% (45 ears). The correlation between abnormal tympanic membrane findings and significant CN was significant and the association between CN and middle ear effusion (MEE) was not statistically significant. CONCLUSIONS: Significant CN is a sensitive diagnostic tool for detection of MEE but not specific. The diagnosis of OME in children requires a combinational diagnostic methods including tympanometry and audiometric variables especially CN. PMID- 19875182 TI - Competition between selenomethionine and methionine absorption in the intestinal tract of green sturgeon (Acipenser medirostris). AB - l-Selenomethionine (SeMet) is a dominant form of selenium (Se) found in organisms at all levels of aquatic food chains and a key source of Se bioaccumulation and ecotoxicity. In mammals, intestinal absorption of SeMet is at least partly via the Na(+)-dependent neutral amino acid transporter. The mechanism of SeMet absorption and competitive effects of other dietary components on SeMet absorption in fish are unknown. Thus the in vitro uptake rates of l-methionine (Met) and the competitive effect of SeMet on Met absorption, an indicator that SeMet uses the same nutrient transporter(s) for absorption, in the various regions of the green sturgeon (Acipenser medirostris) intestine were investigated using intact tissues (a modified everted sleeve method). Intestinal tissue was incubated in Ringer's solution containing 0-10mmolL(-1) Met or SeMet (n=5 for each substrate's concentration and intestinal region), respectively, as well as constant tracer levels of isotope-labeled Met. The data indicate that SeMet uptake was mediated by the same transporter(s) as Met and that the absorption kinetics were similar for both substrates. When there were differences in absorption they appeared to be mostly due to higher permeability (passive uptake) of the tissue for Met than for SeMet, particularly in the pyloric caeca (PC) and distal intestine (DI). Maximum rates of absorption, on the other hand, tended to be higher for SeMet than Met in the mid intestine and DI, whereas differences in affinity for the transporters varied between these tissues but were very similar in the PC. These differences may be due to differences in regional intestinal characteristics such as amount of mucus secreted and degree of tissue contraction, and/or substrate differences regarding solubility in and movement through the mucus, influence on tissue contraction, permeability through membranes or between cells, intracellular metabolism, as well as basolateral transport. Interestingly, an increasing proximal-to-distal gradient for rates of methionine and putative SeMet absorption was observed in green sturgeon which differs from the declining gradient usually observed for substrate absorption in other fish species and mammals. PMID- 19875183 TI - Usefulness of Q waves on ECG for the prediction of contractile reserve after acute myocardial infarction. AB - BACKGROUND: Controversy exists regarding the significance of pathological 'Q' waves on electrocardiography (ECG) following established acute myocardial infarction (AMI) in predicting non-viable myocardium. AIM: The aim of the study was to ascertain the reliability of 'Q' waves on ECG to predict myocardial viability following AMI. METHODS: 176 patients underwent both ECG and DSE, at a mean of 4.9 days post AMI. Non-viability on ECG and DSE was defined as mentioned below. Both ECG and DSE were used to evaluate 352 (176 anterior and 176 inferior) myocardial territories for viability. RESULTS: The positive predictive value and the negative predictive value of 'Q' waves on ECG to predict non-viable myocardium were 43% and 85% respectively. The sensitivity for ECG to detect non viable myocardium was rather low for both anterior and inferior 'Q' waves (64% and 65% respectively), and, the specificity was as well not high enough (72% for anterior and 69% for inferior). CONCLUSION: The presence of extensive 'Q' waves does not predict non-viable myocardium. Whereupon, absence of 'Q' waves predicts the presence of viable myocardium for inferior territory but this is relatively less reliable for anterior territory. Myocardial viability should be sought in patients with extensive 'Q' waves and in unclear anterior territories. PMID- 19875184 TI - Vagal impairment in elderly Chagas disease patients: a population-based study (the Bambui study). AB - BACKGROUND: Chagas disease (ChD) will become predominantly a disease of the elderly, as a consequence of the effectiveness of control measures in many Latin American countries. The effects of the disease in old age have received little attention. We investigated the effects of ageing in the association between cardiac vagal impairment, a typical feature of ChD, and chronic Trypanosoma cruzi infection. METHODS: The study sample of this cross-sectional study consists of 1014 subjects >= 60 years old (mean age = 68.3; SD = 6.9) residing in Bambui City (Southeast Brazil). ECG was recorded and one-breath sinus arrhythmia test was performed. Maximal expiratory over the minimal inspiratory (E:I) ratio and heart rate variability (HRV) measurements were calculated. Ordinal logistic regression was used to assess the relation between vagal indexes and chronic T. cruzi infection. RESULTS: The prevalence of T. cruzi infection was 32.0% and of major ECG abnormalities, 43.4%. Among individuals aged 60-69 years, T. cruzi infection was significantly and independently associated with reduced SDNN (OR 0.38; 95% CI 0.27-0.53), RMSSD (OR 0.48; 0.34-0.67) and EI: ratio (OR 0.45; 95% CI 0.33-0.63). Among individuals aged >70 years, no significant odds ratios were found in either the unadjusted or the adjusted analysis. The presence of major ECG abnormalities did not affect the association between vagal indexes and T. cruzi infection. CONCLUSIONS: Disease-specific vagal cardiac dysfunction was observed in ChD individuals below 70. However, further ageing interferes significantly with vagal heart modulation, attenuating the difference of HRV indexes between ChD and non ChD subjects. PMID- 19875185 TI - Bioproduction of resveratrol and stilbene derivatives by plant cells and microorganisms. AB - Trans-resveratrol is a phenolic plant compound that has been recognized for its benefits on human health. Currently, increasing demand for trans-resveratrol for nutraceutical, cosmetic, and putatively pharmaceutic uses makes its production from sustainable sourcing a necessity. In this context, the use of biotechnology through recombinant microorganisms and plant cell suspensions is particularly promising because it represents a reliable alternative method of trans resveratrol production under controlled conditions. Tailoring yeast or bacteria with genes that encode enzymes of the trans-resveratrol pathway and further elicitation of plant-cell metabolism might represent powerful strategies for increased trans-resveratrol bioproduction. This review aims at describing and comparing these different available methods, with a focus on their respective advantages, limits and perspectives as a basis for scale-up in large culture volumes. PMID- 19875186 TI - Effect of fat in ground beef on the growth and virulence plasmid (pYV) stability in Yersinia pestis. AB - Knowledge of the behavior of Yersinia pestis in food may be useful in the event Y. pestis is used in a bioterrorism attack on the food supply. However, there are no reports on the growth of plasmid-bearing (pYV) virulent Y. pestis in food. The growth of a conditionally virulent pYV-bearing Y. pestis KIM5 in sterile raw ground beef with 7, 15 and 25% fat content was studied at 0, 4, 10 and 25 degrees C. The Y. pestis KIM5 did not grow but survived in raw ground beef at 0 and 4 degrees C. In raw ground beef with fat contents of 7, 15 and 25% Y. pestis KIM5 replicated at 10 degrees C with growth rates of 0.06, 0.05, and 0.06 log(10) CFU/h and maximum population densities of 8.65, 8.30, and 8.43 log(10) CFU/g, respectively. The growth rate was 4-fold higher and the maximum population density was slightly higher at 25 degrees C in raw ground beef at all levels of fat as compared to 10 degrees C. Moreover, there was no loss of pYV in surviving Y. pestis KIM5 in raw ground beef stored at refrigerator temperatures or during its growth in raw ground beef. This suggests that raw ground beef contaminated with virulent Y. pestis could cause oro-pharyngeal plague due to refrigeration failure, temperature (10-25 degrees C) abuse, and if the meat was not properly cooked. The resultant disease may lead to outbreaks of highly infectious pneumonic plague. PMID- 19875187 TI - Enhanced photocatalytic disinfection of P. expansum in cold storage using a TiO2/ACF film. AB - Spores of Penicilliumexpansum are the most important airborne component of fungal contamination and are commonly present in the moist air in cold storage rooms where fruits and vegetables are stored. To improve the ability of activated carbon felt-supported titanium dioxide (TiO2/ACF) to remove spores of P. expansum from the atmosphere, measurements for the removal efficiency of the spores at a temperature of 3 degrees C+/-1 degrees C and relative humidity of 90%+/-3% had been made on photocatalytically-activated (PC) silver-doped TiO2/ACF prepared by ion sputtering in two different modes and photoelectrocatalytically-activated (PEC) TiO2/ACF films. The Weibull distribution model was used to define the degree of microbial inactivation attributable to the PC or PEC films. The key parameters of the PC or PEC affecting the disinfection efficiency in terms of the reliable life (t(R) value) of this model were studied. Both silver-doped TiO2/ACF and PEC on TiO2/ACF improved destruction of this airborne microbe. Silver deposited on the surface of the prepared ACF-supported TiO2 films (Ag/Ti=0.012, atomic ratios) dramatically reduced t(R) value. With respect to the PEC, a model was established using response surface methodology to describe the relationship between the t(R) value and the key affecting parameters, including light intensity and bias voltage. The optimized parameters were found to be a light intensity of 2.3 mW x cm(-2) with a bias voltage of 66.7 V. PMID- 19875188 TI - Shiga toxin Stx2 is heat-stable and not inactivated by pasteurization. AB - Shiga toxin-producing Escherichia coli have been associated with food-borne illnesses. Pasteurization is used to inhibit microbial growth in milk, and an open question is whether milk pasteurization inactivates Shiga toxins. To answer this question we measured Shiga toxin's inhibition effect on Vero cell dehydrogenase activity and protein synthesis. Our data demonstrate that Shiga toxin 2 (Stx2) is heat-stable and that pasteurization of milk, at the various suggested temperatures and times by the U.S. Food and Drug Administration, (63 degrees C for 30 min, or 72 degrees C for 15s or 89 degrees C for 1s), did not reduce the biological activity of Stx2. However, treatment at 100 degrees C for 5 min inactivated the toxin. These data demonstrate that Stx2 is not inactivated by conventional pasteurization. PMID- 19875189 TI - Neuropsychological status of elderly patients with diabetes mellitus. AB - AIM: Diabetes mellitus (DM) is an important risk factor for Alzheimer's disease (AD) but the relationship between DM and amnestic mild cognitive impairment (aMCI), characterized by isolated memory loss, is unclear. We studied the prevalence of MCI in DM patients. METHODS: Neuropsychological status was evaluated using the Rivermead Behavioral Memory Test (RBMT) and the Mini Mental State Examination (MMSE). Subjects consisted of 103 consecutive diabetic patients hospitalized for diabetic education. Patients with severe diabetic complications or cerebrovascular accidents were excluded. RESULTS: Neuropsychological evaluation of DM patients showed that 71% were normal (MMSE score > or =24 and RBMT score > or =15), 5% had amnestic MCI (aMCI) (MMSE score > or =24 and RBMT score <15) and the remaining 23% had dementia (MMSE score <24). The percentage of patients with dementia was significantly higher in the DM group than in the control group (p<0.04). RBMT score and HbA1c were mildly correlated in diabetic patients. CONCLUSION: High blood sugar may cause deterioration in not only memory function but also other cognitive domains in elderly patients with DM. Monitoring the neuropsychological status of this patient population is important. PMID- 19875191 TI - Counting the cost of type 2 diabetes in Vanuatu. AB - AIM: To determine the health system costs, cost to people with diabetes and their carers, and impact on quality of life associated with type 2 diabetes in Vanuatu. METHODS: A cross-sectional paper based survey was administered to 199 people with type 2 diabetes as part of a larger diabetes project. RESULTS: There were 172 respondents (86% response rate) with a mean age of 56 years (mean duration of diabetes 8 years, 106 females; 67 unemployed). Over the preceding year there were 2352 outpatient visits for health care totalling 442,400 vatu ($4020 USD); 140 overnight hospital stays totalling 1,383,620 vatu ($12,580 USD); and prescription medications costing 3220 vatu/person ($29.20 USD). Major out-of-pocket costs for individuals were the over-the-counter medications totalling 6600 vatu/person/year ($60 USD) for 31 people (18%); transport at 1980 vatu/person/year ($18.00 USD) for 110 people (64%) and special diets for 38 people (22%) costing 36,480 vatu/person ($332 USD). Quality of life was 91/100 on the EQ-5D visual analogue scale. CONCLUSIONS: Given that diabetes in Vanuatu is likely to be significantly under-diagnosed and under-treated the current costs, while substantial are artificially low but are set to rise sharply with increased awareness of diabetes and growing rates of obesity. PMID- 19875190 TI - Nephropathic complication of type-2 diabetes is following pattern of autoimmune diseases? AB - The impact of several environmental and genetic factors on diabetes and its complications is well documented. The present study was aimed to examine the serum levels of IL-17A and IFN-gamma as antagonistic cytokines in nephropathic and non-nephropathic type-2 diabetic patients. In this experimental study, serum samples were obtained from 180 type-2 diabetic patients, 100 nephropathic type-2 diabetic patients and 100 healthy controls. Serum levels of IL-17A and IFN-gamma was detected by ELISA. Results of this study showed that the serum level of IFN gamma was higher in both diabetic patients (nephropathic and non-nephropathic) in comparison to the controls. In terms of IL-17A, while non-nephropathic type-2 diabetic patients showed an increased serum level of it, the other patients group had a lower serum level. Based on these findings, it can be concluded that the lower serum level of IL-17A is possibly associated with nephropathic complications of type-2 diabetes. PMID- 19875193 TI - Methodological aspects of lung cancer clinical trials in the era of targeted agents. AB - Methodology of clinical trials conducted in lung cancer, similarly to other tumours, has been recently challenged by the particular characteristics of new targeted agents. Traditional methodology of phase II trials has been questioned, both for the choice of the endpoint and for the study design itself. Due to the mechanism of action of new drugs, cytostatic more than cytotoxic at least in principle, the usual endpoint of phase II trials, objective response rate, is now often replaced by alternative event-related endpoints, such as progression-free survival or progression-free rate at a fixed time-point. Randomized phase II trials, considered in the past the exception rather than the rule, have been encouraged, as the only design useful to give clear information on the activity of experimental treatments. Conduction of phase III trials remains mandatory to demonstrate treatment efficacy, but their endpoints and design are currently object of discussion. With targeted agents, great efforts have been made to identify predictive factors of treatment efficacy, but this aspect appears to be more complicated than hypothesized in principle. The history of clinical trials with epidermal growth factor receptor inhibitors in advanced NSCLC is a good example of the uncertainty about predictive factors and selection criteria. Moreover, non-inferiority design has been used for several phase III trials comparing targeted agents with chemotherapy. In this review, recent aspects of clinical trials methodology in lung cancer are described, and examples of their application are discussed. PMID- 19875192 TI - Association of expression of MRP1, BCRP, LRP and ERCC1 with outcome of patients with locally advanced non-small cell lung cancer who received neoadjuvant chemotherapy. AB - PURPOSE: The aim of this study was to investigate prognostic value of multidrug resistance protein 1 (MRP1), breast cancer resistance protein (BCRP), lung resistance-related protein (LRP) and excision repair cross-complementing 1 (ERCC1) in patients with locally advanced non-small cell lung cancer (NSCLC) who received neoadjuvant cisplatin-based chemotherapy. METHODS: Transbronchial biopsy (TBB) specimens from 46 patients with stage IIIA (N(2)) NSCLC were collected to determine the expression level of MRP1, BCRP, LRP and ERCC1 mRNA by semiquantitative RT-PCR. The expression level of each gene was analyzed in relation to histopathologic response to chemotherapy, and tumor-free survival (TFS) and overall survival. RESULTS: Patients with MRP1 or LRP low expression had a significantly better histopathologic response (P=0.032 and 0.006), and a significantly longer TFS (P=0.043 and 0.025) and overall survival (P=0.019 and 0.013) than those with MRP1 or LRP high expression. Patients with ERCC1 low expression had a significantly longer overall survival (P=0.007), but not TFS (P=0.094) than those with ERCC1 high expression. In multivariate analysis, LRP low expression was a significantly favorable factor for TFS (P=0.027), and LRP and ERCC1 were significantly favorable factors for overall survival (P=0.012 and 0.032). CONCLUSION: Assessment of MRP1 and LRP mRNA expression in TBB specimens may predict histopathologic response and survival in locally advanced NSCLC patients who received neoadjuvant cisplatin-based chemotherapy. ERCC1 expression was predictive for overall survival. PMID- 19875194 TI - Alteration in phosphate uptake potential of wheat plants co-cultivated with salicylic acid. AB - The phosphate uptake potential was significantly stimulated with low concentration of salicylic acid (SA). In one of the wheat cultivars (Triticum aestivum Var. Sonalika), 50 microM SA stimulated phosphate (PO(4)(3-)) uptake. At higher concentrations of SA (500 and 1000 microM), the rate of uptake was reduced. These findings underscore the light and dose-dependent biphasic action of SA: a low 50 microM stimulated, and high concentrations 500 and 1000 microM inhibited, PO(4)(3-) uptake. PMID- 19875195 TI - Urocortin modulates dopaminergic neuronal survival via inhibition of glycogen synthase kinase-3beta and histone deacetylase. AB - Urocortin (UCN) is a member of the corticotropin-releasing hormone (CRH) family of neuropeptides that regulates stress responses. Although UCN is principally expressed in dopaminergic neurons in rat substantia nigra (SN), the function of UCN in modulating dopaminergic neuronal survival remains unclear. Using primary mesencephalic cultures, we demonstrated that dopaminergic neurons underwent spontaneous cell death when their age increased in culture. Treatment of mesencephalic cultures with UCN markedly prolonged the survival of dopaminergic neurons, whereas neutralization of UCN with anti-UCN antibody accelerated dopaminergic neurons degeneration. UCN increased intracellular cAMP levels followed by phosphorylating glycogen synthase kinase-3beta (GSK-3beta) on Ser9. Moreover, UCN directly inhibited the histone deacetylase (HDAC) activity and induced a robust increase in histone H3 acetylation levels. Using pharmacological approaches, we further demonstrated that inhibition of GSK-3beta and HDAC contributes to UCN-mediated neuroprotection. These results suggest that dopaminergic neuron-derived UCN might be involved in an autocrine protective signaling mechanism. PMID- 19875196 TI - [Administration of statins during the acute phase of acute coronary syndrome]. AB - The benefits of statins in patients with stable coronary syndrome is indisputable, however their early use in acute coronary syndrome (ACS) is under debate. There are few existing clinical trials and meta-analysis results on this and their results provide little clarification. However, most of the registries have found them to be efficient. There are no studies that show this therapy to be unsafe, so its inclusion in treatment guidelines during the acute phase of ACS could be studied. PMID- 19875197 TI - [Central venous catheter insertion in a persistent left superior vena cava]. PMID- 19875198 TI - [Primary diffuse large B-cell lymphoma of the rectum simulating a rectal adenocarcinoma]. AB - Colorectal lymphoma is an extremely infrequent entity, representing less than 0.5% of all primary colorectal neoplasms. Colorectal localization accounts for 15 20% of all gastrointestinal lymphomas, after the stomach and small intestine. Because the symptoms are non-specific, this disease is usually diagnosed in the advanced stages. Dawson's criteria are highly useful in the differential diagnosis between primary colorectal involvement and gastrointestinal tract involvement secondary to systemic lymphoma, which is important due to the distinct prognosis and treatment of these entities. We report the case of a B cell non-Hodgkin's lymphoma that was difficult to diagnose and was treated with R CHOP polychemotherapy. Outcome was poor. PMID- 19875199 TI - [Helping fish to live? Metamorphosis of a structured objective clinical evaluation (ECOE) for a family medicine intern in the last year of medical school]. PMID- 19875200 TI - [Characteristics of sexually transmitted infections diagnosed in a health centre]. PMID- 19875201 TI - [Family Medicine and university, what do students think?]. PMID- 19875202 TI - [Teaching objectives in resident rotation in a health centre like R4. Can they really be achieved?]. PMID- 19875203 TI - [Application and quantitative-qualitative evaluation of an index to identify family priorities at primary health care level]. PMID- 19875204 TI - [Concept and applications of the Web 3.0: an introduction for medical doctors]. AB - The development of the Internet is continuous and appears to be never-ending, although with the arrival of Web 3.0 it could be said that the Internet is what its creators intended it to be from the first moment, an extraordinary and immense organised, understandable, and easy to access data base, characteristics still not achieved. The innovations and services included in Web 3.0 will result, in the first place, in better, faster and safer access to quality information. In the second place it should provide better personalisation of the health services that Internet users access, avoiding irrelevant information that may contain wrong, false and dangerous recommendations. However, these changes will have to be accompanied by the legal requirements common to the information society, by the ethical aspects associated with medical care, guaranteeing and contributing, in all cases, to improving the doctor-patient relationship. PMID- 19875205 TI - Sigma-1 ligands: Tic-hydantoin as a key pharmacophore. AB - Sigma-1 receptors are involved in numerous pathological dysfunctions and the synthesis of selective ligands is of interest. We identified a fused tetrahydroisoquinoline-hydantoin (Tic-hydantoin) structure with high affinity and selectivity for these receptors. We report here our efforts towards the pharmacomodulation of this substructure, the synthesis of 9 analogs with stereochemistry inversion, opening of isoquinoline ring, removal of isoquinoline nitrogen, replacement of isoquinoline by pyridine, of Tic-hydantoin moiety by quinazolinedione heterocycle. All these analogs provided a loss in the affinity for the sigma-1 receptor. The present work underlines the real importance of the Tic-hydantoin moiety for the obtainment of high affinity ligands. PMID- 19875206 TI - [Anemia of inflammation: Physiopathology and treatment]. PMID- 19875207 TI - [Radiology in Takayasu's disease]. PMID- 19875208 TI - [Medical treatment of Takayasu's disease]. PMID- 19875209 TI - [Pharmacogenetic's use in practical]. PMID- 19875210 TI - [Atherosclerosis in Takayasu's disease]. PMID- 19875211 TI - [Behcet's disease: new therapeutics]. PMID- 19875212 TI - Inactivity-mediated insulin resistance is associated with upregulated pro inflammatory fatty acids in human cell membranes. AB - BACKGROUND & AIMS: Low-grade systemic inflammation and pro-inflammatory pattern of cell membrane fatty acid composition characterize patients affected by type 2 diabetes and metabolic syndrome. We hypothesize that inactivity-induced insulin resistance could affect levels of pro-inflammatory fatty acids in cell membranes. METHODS: Thirty healthy, male, young volunteers were investigated before and after 35-day experimental bed rest. Diet composition was adapted to previous dietary habits. Fatty acid composition of erythrocyte membranes was analyzed by gas-chromatography using flame ionization detector. RESULTS: Following bed rest, the HOMA index of insulin resistance significantly increased by +51+/-11% (P<0.01). Bed rest was associated with increased n-6 polyunsaturated (+4.7+/ 2.2%; P<0.01) and decreased monounsaturated (-4.8+/-1.5%; P<0.01) fatty acid content in erythrocyte membranes. Fractional content of arachidonic acid increased by +14+/-12% (P=0.01) following inactivity. Delta5 and Delta9 desaturase indexes, as estimated from product-to-precursor ratios, significantly diminished following bed rest from 9.6+/-0.4 to 8.4+/-0.3 (P<0.001) and from 0.72+/-0.02 to 0.69+/-0.01 (P<0.05), respectively. The n-3 fatty acids, alpha linolenic and eicosapentaenoic, were decreased (P=0.05) following inactivity by 4.7+/-13.2% and 3.8+/-5.2%, respectively. CONCLUSIONS: Inactivity-mediated insulin resistance was associated with altered Delta5 and Delta9 desaturase indexes and with pro-inflammatory fatty acid pattern in erythrocyte membranes. These abnormalities could contribute to the low-grade inflammation associated to inactivity. PMID- 19875213 TI - Contributing to shipping container security: can passive sensors bring a solution? AB - Illicit trafficking of fissionable material in container cargoes is recognized as a potential weakness in Nuclear Security. Triggered by the attacks of 11 September 2001, measures were undertaken to enhance maritime security in extension to the Safety Of Life At Sea Convention and in line with the US Container Security Initiatives. Effective detection techniques are needed that allow the inspector to intercept illicit trafficking of nuclear weapons components or components of other nuclear explosive devices. Many security measures focus on active interrogation of the container content by X-ray scan, which might be extended with the newly developed tagged neutron inspection system. Both active interrogation techniques can, with the current huge volume of container traffic, only be applied to a limited number of selected containers. The question arises whether a passive detection technique can offer an alternative solution. This study investigates if containers equipped with a small passive detector will register during transport the neutron irradiation by fissionable material such as plutonium in a measurable way. In practice, 4/5 of the containers are about 1/8 filled with hydrogenous material and undergo a typical 2 months route. For this reference case, it was found that the most compatible passive detector would be an activation foil of iridium. Monte-Carlo simulations showed that for the reference case the activity of a 250 microm thin foil with 6 cm(2) cross-section would register 1.2 Bq when it is irradiated by a significant quantity of Reactor-Grade PuO(2). However this activity drops with almost two orders of magnitude for other fillings and other isotopic compositions and forms of the Pu-source. The procedure of selecting the target material for Pu detection is detailed with the theoretical methods, in order to be useful for other applications. Moreover the value of such additional passive sensors for securing maritime container transport is situated within the global framework of the First, Second and Third Line of Defense against illicit trafficking. PMID- 19875214 TI - Modeling the (212)Pb activity concentration in the lower atmosphere. AB - A worldwide radionuclide network of 80 stations, part of the International Monitoring System, is being setup to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The radioactivity sampled at these stations is primarily (220)Rn progenies affecting the detection capability. A model linking the (220)Rn emanation with the sampled (212)Pb activity was developed and is presented here. The model and the performed measurements show that the variation of the sampled (212)Pb activity can be fully explained by the variation of the local (220)Rn activity concentration. PMID- 19875215 TI - Past horrors, present struggles: the role of stigma in the association between war experiences and psychosocial adjustment among former child soldiers in Sierra Leone. AB - Upon returning to their communities, children formerly associated with armed forces and armed groups--commonly referred to as child soldiers--often confront significant community stigma. Much research on the reintegration and rehabilitation of child soldiers has focused on exposure to past war-related violence and mental health outcomes, yet no empirical work has yet examined the role that post-conflict stigma plays in shaping long-term psychosocial adjustment. Two waves of data are used in this paper from the first prospective study of male and female former child soldiers in Sierra Leone. We examined the role of stigma (manifest in discrimination as well as lower levels of community and family acceptance) in the relationship between war-related experiences and psychosocial adjustment (depression, anxiety, hostility and adaptive behaviors). Former child soldiers differ from one another with regard to their post-war experiences, and these differences profoundly shape their psychosocial adjustment over time. Consistent with social stress theory, we observed that post-conflict factors such as stigma can play an important role in shaping psychosocial adjustment in former child soldiers. We found that discrimination was inversely associated with family and community acceptance. Additionally, higher levels of family acceptance were associated with decreased hostility, while improvements in community acceptance were associated with adaptive attitudes and behaviors. We found that post-conflict experiences of discrimination largely explained the relationship between past involvement in wounding/killing others and subsequent increases in hostility. Stigma similarly mediated the relationship between surviving rape and depression. However, surviving rape continued to demonstrate independent effects on increases in anxiety, hostility and adaptive/prosocial behaviors after adjusting for other variables. These findings point to the complexity of psychosocial adjustment and community reintegration in these youth and have a number of programmatic and policy implications. PMID- 19875216 TI - Alertness in young healthy subjects: an fMRI study of brain region interactivity enhanced by a warning signal. AB - An effective connectivity study was carried out on 16 young, healthy subjects performing an alertness task. The objective of this study was to develop and to evaluate a putative network model of alertness by adapting structural equation modeling to fMRI data. This study was designed to evaluate the directed interactivity of an attentional network during intrinsic and phasic alerting tasks. On the basis of theoretical hypotheses, clinical observations, behavioral data and neuroimaging studies, it was hypothesized that neural circuits in the right hemisphere including the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex, inferior parietal cortex and the thalamus were involved. The results of this study support the existence of a common network of activated areas with significant path coefficient differences between intrinsic and phasic alertness. Functional interactivity was significantly reinforced during the phasic alertness task and appeared to preferentially involve activity in the DLPFC region, whereas the path coefficients of the model were well-balanced during intrinsic alertness. This study highlights the predominant role of the DLPFC region in maintenance of a state of alertness and in temporal preparation during an alertness task. PMID- 19875217 TI - [Lipofilling and weight gain. Case report and review of the literature]. AB - Since Coleman's studies, lipofilling has become an easy, reliable and reproducible surgical technique particularly in severe Romberg's syndrome that is characterised by a progressive facial hemi-atrophy of cutaneous and subcutaneous tissues. Considering a young patient case, the authors expose a rare complication of lipofilling: deterioration of the aesthetic results after a significative weight gain due to corticosteroids, oral contraception and a change of lifestyle. Lipofilling is an adipocyte graft realised after centrifugation of liposuction products. Thus, the increasing volume of the fat graft remains hypertrophic and hyperplasic theories. Indeed, the technique produces a concentrated fat graft that realises an asymmetry of fat distribution in both sides of the face. The authors present their preliminary results. PMID- 19875218 TI - [Mondor's disease and breast plastic surgery]. AB - AIM: Mondor's disease is a rare complication following breast plastic surgery. CASE REPORT: We report the case of a 40-year-old woman with breast shape and volume asymmetry. She was treated by left breast submuscular prothesis augmentation followed by right breast mastopexy 6 months later. Following this surgery, she presented with subcutaneous painful abdominal cords on the right side or Mondor's disease. DISCUSSION: We discuss the diagnosis, physiopathology and treatment of this disease in the light of scientific literature. The physiopathology is based on fascial origin in a context of local vascularitis. CONCLUSION: Mondor's disease is a rare but benign pathology following breast plastic surgery. The treatment is symptomatic and the surgeon must reassure the patient on the benignity and the lack of consequence on the final cosmetic result. PMID- 19875219 TI - [Inflammation markers in the exhaled air of patients with bronchiectasis unassociated with cystic fibrosis]. AB - INTRODUCTION: The aim of the study was to analyse the relationship between the intensity of the respiratory tract inflammation, expressed by oxidative stress markers, and the severity of the disease in patients with bronchiectasis unassociated with cystic fibrosis. PATIENTS AND METHODS: The study included 25 patients with stable bronchiectasis (15 females and 10 males). As determining factors of severity, the following parameters were collected: degree of dyspnoea, number of exacerbations/admissions in the last year, mean daily sputum volume, sputum colour (graduated colour scale), bacterial colonisation, respiratory function tests, quality of life (St. George questionnaire) and radiological extension of the lesions (Bhalla scale). Inflammation was analysed using the measurement of nitric oxide, pH and concentration of nitrites, nitrates and isoprostane in the exhaled air condensate. The C reactive protein and erythrocyte sedimentation rate were also determined in peripheral blood. RESULTS: There were no significant relationships between the markers in the exhaled air condensate and the clinical, radiological and functional involvement or the quality of life of the patients. Only bacterial colonisation (16 cases) was associated with higher values of nitrates in exhaled air (mean+/-standard deviation: 18+/-4 compared to 7+/-2microM; r(2)=0.6) and a higher number of exacerbations (3.1+/ 1.9 compared to 1.7+/-1.9; r(2)=0.3). CONCLUSIONS: In our study, the measurement of inflammation markers in exhaled air is only associated with some parameters of severity in patients with bacterial bronchiectasis. PMID- 19875220 TI - [Aspiration of a button battery: a unique case in the medical literature]. PMID- 19875221 TI - [Pulmonary toxicity due to methenolone: a case report]. PMID- 19875222 TI - Rapid oral tolerance induction to isoniazid and pyrazinamide and controlled administration of ethambutol: clinical case. PMID- 19875223 TI - Response to budesonide among atopic and non-atopic infants/preschoolers with recurrent wheezing. AB - BACKGROUND: The treatment in non-atopic young children with recurrent wheezing remains controversial. OBJECTIVE: The aim of the study was to compare the response of inhaled budesonide in atopic versus non-atopic infants/preschoolers with recurrent wheezing (more than three episodes in the last year or one episode per month in the last three months). METHODS: One hundred and seventy three infants/preschoolers (mean age 1.58+/-0.9 yrs) with recurrent wheezing without previous use of inhaled corticosteroids were enrolled and divided into two categories: atopics (eosinophils in peripheral blood > or =4%) and non-atopics (<4%). Both groups were treated with budesonide (200 mcg bid delivered by MDI and spacer) for three months. The primary outcome was the prevalence of wheezing exacerbation episodes at the end of the treatment. RESULTS: Thirty-seven out of 173 (21.4%) were atopics and they were significantly younger, more frequently with a father with asthma, maternal grandparents with asthma and rhinitis, paternal and maternal grandparents with eczema, and higher number of wheezing episodes in the last year than non-atopics. At the end of the study, among those with good compliance (>70% of the weekly doses), the proportion of wheezing episodes were similar among atopics and non-atopics (57.7% vs. 44.1%, p=0.25, respectively); the number of exacerbations requiring emergency department (ED) visits and hospital admission were also similar. CONCLUSION: Regular budesonide therapy may decrease the episodes of wheezing in infants/preschoolers with recurrent wheezing, independently of atopy. PMID- 19875224 TI - Stevens-Jonhson syndrome after acetaminophen ingestion, confirmed by challenge test in an eleven-year-old patient. PMID- 19875225 TI - The connection between early life wheezing and subsequent asthma: The viral march. AB - Several new lines of evidence suggest that alterations in immune responses which predispose to bronchial obstruction during acute respiratory infection, especially with rhinoviruses, may explain to a considerable extent the link between early life wheezing and subsequent asthma; above all among those schoolchildren who are prone to having recurrent asthma exacerbations. The nature of these alterations is currently the subject of considerable scrutiny, but cross sectional studies suggest that deficits in innate immune responses mediated by interferon type I and III are present in lung macrophages and epithelial cells of adult asthmatics. Similarly, long-term follow-up studies suggest that deficits in interferon gamma responses in the first year of life predispose to recurrent episodes of wheezing from the preschool years and into early adolescence. A better understanding of the "viral march" could yield new therapeutic approaches for the prevention and treatment of acute severe airway obstruction during childhood. Several longitudinal studies have provided convincing evidence that, in most cases of asthma, the first symptoms of the disease occur during the preschool years.(1-3) Young children who will go on to develop asthma later in life usually have recurrent episodes of wheezing, cough, and difficulty to breathe ("persistent wheezers"),(4) and these episodes are associated with molecular evidence of viral respiratory infection in up to 90% of cases.(5) However, the majority of infants aged <1 year who wheeze remit by the age of 3 (the so-called transient wheezers(6)), and their episodes are also associated with viral infections. Until very recently, a predisposition to allergy was the main disease mechanisms believed to connect early life wheezing with subsequent asthma.(7) The purpose of this brief comment is to review the evidence which suggests that susceptibility to infection with rhinovirus may be a critical additional factor explaining this connection. PMID- 19875226 TI - Dynamic and supramolecular organisation of alpha-lactalbumin/lysozyme microspheres: A microscopic study. AB - Apo alpha-lactalbumin (apo alpha-LA) and lysozyme (LYS), two homologous globular proteins have been shown to be able to interact and self-assemble to form microspheres. We report on the organisation and the mechanism of such protein assembly process using a variety of microscopic techniques. We demonstrated that proteins involved into apo alpha-LA/LYS microspheres exchange with those free in solution. The exchange process takes place from the periphery to the centre of the microspheres. The formed spherical particles observed after fixed incubation time were found to be either individual or aggregated according to the total protein concentration leading to structures with different size and morphology. It appears that protein assembly occurs throughout successive steps of aggregated spherical particles that reorganise into biggest isolated microspheres. Direct microscopic observations over time confirm that microspheres resulted from a reorganisation of aggregated, clustered nanospheres. We propose that the formation of apo alpha-LA/LYS microspheres follows an "aggregation reorganisation" mechanism. PMID- 19875227 TI - The Epstein criteria predict for organ-confined but not insignificant disease and a high likelihood of cure at radical prostatectomy. AB - BACKGROUND: Few reports attempt to validate the role of Epstein criteria in selecting patients for an active surveillance protocol. OBJECTIVE: To determine the performance of the Epstein biopsy criteria for predicting pathologic end points and biochemical relapse-free survival (bRFS) in men with early stage prostate cancer (PCa) treated by radical prostatectomy (RP). DESIGN, SETTING, AND PARTICIPANTS: Between October 1999 and January 2007, 746 consecutive patients were biopsied, and then underwent RP at our tertiary care institution. Two hundred sixty-eight patients met the entry criteria of Gleason 6 disease only on initial biopsy with complete pathologic information. MEASUREMENTS: Primary end point was insignificant disease. Insignificant disease was defined using a classical (organ-confined, Gleason score <6, and tumor volume <0.5 cm(3)) and more liberal (organ-confined, Gleason <6 tumor of any volume) formulation. Secondary end points included organ-confined disease and bRFS. RESULTS AND LIMITATIONS: One hundred thirty-six men (51%) met the Epstein biopsy criteria, and 167 (62%) had organ-confined cancer. Insignificant disease by the classical and liberal definitions was present in 68 (25%) and 92 (34%) patients, respectively. Cases meeting Epstein biopsy criteria were more likely to have insignificant disease by either definition (p<0.001) and more likely to have organ-confined tumors (p<0.001). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) varied widely among the end points, with sensitivity (74%) and NPV (86%) best for the classical definition of insignificant disease and specificity (74%) and PPV (92%) best for organ-confined disease. The estimated 5-yr bRFS was 100% for those meeting Epstein biopsy criteria compared to 83% for those not meeting these criteria. CONCLUSIONS: The Epstein biopsy criteria predict for a high likelihood of organ-confined disease and the absence of biochemical failure up to 5 yr after RP. These criteria are insufficiently robust to predict the presence of biologically insignificant disease. PMID- 19875228 TI - Surgical treatment and outcome of skull base meningiomas with extracranial extensions. AB - OBJECTIVE: Recurrent cranial base meningiomas occasionally extend into craniofacial structures, and are one of the most difficult tumors to surgically manage. We reviewed our experience of surgical treatment in a series of patients with meningiomas showing extensive extracranial extensions. METHODS: We surgically treated a total of 10 patients with recurrent cranial base meningiomas with large extension to multiple craniofacial structures. All patients underwent orbitozygomatic or zygomatic frontotemporal craniotomy for surgical resection of the tumor. An endoscopic endonasal technique was also employed, if necessary, as an adjunct to the transcranial approach. RESULTS: Eight patients were treated solely with a frontotemporal approach associated with an extended resection of the floor of the middle fossa. In 2 patients, an endoscopic endonasal approach was additionally required for resection of tumors located in the nasal cavity and ethmoid sinus. A gross total resection was achieved without serious surgical complications in 9 out of the 10 patients. In all patients, the tumors were found to invade the surrounding tissue such as the bone and skeletal muscle to varying degrees. CONCLUSION: Our data indicate that recurrent craniofacial meningiomas can usually be managed by using a lateral cranial base approach. Whereas it would be expected that a radical resection may prevent further recurrence with an acceptable quality of life, a long-term follow-up would be required for confirming the benefit of this treatment strategy. PMID- 19875229 TI - Parent artery occlusion with bypass surgery for the treatment of internal carotid artery aneurysms: clinical and hemodynamic results. AB - OBJECTIVE: Parent artery occlusion with/without bypass surgery is one of the treatment choices for the internal carotid artery (ICA) aneurysm difficult to treat by clipping or coiling. There have been few reports regarding postoperative cerebral blood flow (CBF) changes after surgery. This study evaluated the present bypass selection strategy based on balloon test occlusion (BTO) in terms of clinical and hemodynamic outcomes. METHODS: Twenty-one consecutive patients with ICA aneurysms underwent parent artery occlusion. High flow bypass (n=9), superficial temporal artery-middle cerebral artery bypass (n=10), or no bypass (n=2) was performed depending on the changes in clinical symptoms and CBF during BTO. Quantitative CBF measurement with acetazolamide challenge was performed in the chronic stage. RESULTS: Overall outcome at discharge was good recovery 18, moderate disability 2, and severe disability 1. Two patients suffered symptomatic embolic or perforator infarction associated with the surgical manipulations. Preoperative cranial nerve pareses improved completely or partially in all patients except one. CBF in the chronic stage (n=18) demonstrated no significant difference between the surgical and non-surgical cerebral hemispheres. No cerebral ischemic event was observed during the follow-up period (mean 2.9 years). CONCLUSION: The present surgical strategy based on preoperative BTO provides a reliable tool to achieve acceptable clinical and hemodynamic outcomes in patients with complex ICA aneurysms to be treated by parent artery occlusion. PMID- 19875230 TI - Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd Pb exposures. AB - A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. PMID- 19875231 TI - Ammonium removal from aqueous solutions by using natural Chinese (Chende) zeolite as adsorbent. AB - This paper presents a study of the removal of ammonium ion from aqueous solutions using natural Chinese (Chende) zeolite. A series of experiments was conducted to examine the effects of solution pH, particle size, contact time, adsorbent dosage, and the presence of other cation- and anion species on ammonium removal. The findings indicated that these parameters named had a significant effect on the removal of ammonium by the zeolite. The effect of other cations on the removal of ammonium followed the order of preference Na(+)>K(+)>Ca(2+)>Mg(2+) at identical mass concentrations, and the effect of the presence of individual anions followed the order of preference carbonate>chloride>sulfate>phosphate at identical mass concentrations of ammonium ions. Kinetic analysis showed that the adsorption of ammonium on zeolite at different ranges of particle size well followed the pseudo-second-order model and followed the intra-particle diffusion model only during the initial 60 min of the adsorption process. Equilibrium isotherm data was fitted to the linear Langmuir- and Freundlich models with the latter model providing the better description of the process (R(2)=0.991-0.997) compared to the former (R(2)=0.902-0.989). PMID- 19875232 TI - Spinal cord stimulation for failed back surgery syndrome: outcomes in a workers' compensation setting. AB - Questions remain concerning effectiveness and risks of spinal cord stimulation (SCS) for chronic back and leg pain after spine surgery ("failed back surgery syndrome" [FBSS]). This prospective, population-based controlled cohort study evaluated outcomes of workers' compensation recipients with FBSS who received at least a trial of SCS (SCS group, n=51) versus those who (1) were evaluated at a multidisciplinary pain clinic and did not receive SCS (Pain Clinic, n=39) or (2) received neither SCS nor pain clinic evaluation (Usual Care, n=68). Patients completed measures of pain, function, medication use, and work status at baseline and 6, 12, and 24 months later. We also examined work time loss compensation over 24 months. Few (<10%) patients in any group achieved success at any follow-up on the composite primary outcome encompassing less than daily opioid use and improvement in leg pain and function. At 6 months, the SCS group showed modestly greater improvement in leg pain and function, but with higher rates of daily opioid use. These differences disappeared by 12 months. Patients who received a permanent spinal cord stimulator did not differ from patients who received some pain clinic treatment on the primary outcome at any follow-up (<10% successful in each group at each follow-up) and 19% had them removed within 18 months. Both trial and permanent SCS were associated with adverse events. In sum, we found no evidence for greater effectiveness of SCS versus alternative treatments in this patient population after 6 months. PMID- 19875233 TI - Prefrontal cortex modulates placebo analgesia. AB - Expectations and beliefs modulate the experience of pain, which is particularly evident in placebo analgesia. The dorsolateral prefrontal cortex (DLPFC) has been associated with pain regulation and with the generation, maintenance and manipulation of cognitive representations, consistent with its role in expectation. In a heat-pain paradigm, we employed non-invasive low-frequency repetitive transcranial magnetic stimulation (rTMS) to transiently disrupt left and right DLPFC function or used the TMS device itself as a placebo, before applying an expectation-induced placebo analgesia. The results demonstrated that placebo significantly increased pain threshold and pain tolerance. While rTMS did not affect pain experience, it completely blocked placebo analgesia. These findings suggest that expectation-induced placebo analgesia is mediated by symmetric prefrontal cortex function. PMID- 19875234 TI - A new analytical method for characterising the bonding environment at rough interfaces in high-k gate stacks using electron energy loss spectroscopy. AB - Determining the bonding environment at a rough interface, using for example the near-edge fine structure in electron energy loss spectroscopy (EELS), is problematic since the measurement contains information from the interface and surrounding matrix phase. Here we present a novel analytical method for determining the interfacial EELS difference spectrum (with respect to the matrix phase) from a rough interface of unknown geometry, which, unlike multiple linear least squares (MLLS) fitting, does not require the use of reference spectra from suitable standards. The method is based on analysing a series of EELS spectra with variable interface to matrix volume fraction and, as an example, is applied to a TiN/poly-Si interface containing oxygen in a HfO(2)-based, high-k dielectric gate stack. A silicon oxynitride layer was detected at the interface consistent with previous results based on MLLS fitting. PMID- 19875235 TI - Microscopic analysis of calcium ionophore activated egress of Toxoplasma gondii from the host cell. AB - Toxoplasma gondii invades and destroys nucleated cells of warm blooded hosts in a process which involves several steps: recognition, adhesion, penetration, multiplication inside a parasitophorous vacuole (PV) and egress. The last one is the least understood. Parasite egress from LLC-MK2 cells infected with the RH strain of T. gondii was artificially triggered with 4BrA23187 calcium ionophore. The combination of videomicroscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) showed that egress does not result from host cell rupture due to overloading with tachyzoites. Videomicroscopy showed that upon calcium ionophore administration parasite rosettes disassemble, the contour of the parasitophorous vacuole disappears and each tachyzoite takes a separate route to the extracellular medium. FESEM and TEM showed the fragmentation of the intravacuolar network, the fragmentation of parasitophorous vacuole membrane and individual tachyzoites with extruded conoids migrating through the cytosol, tightly surrounded by remnants of parasitophorous vacuole membrane or free in the cytosol. Both videomicroscopy and FESEM showed that a single parasite can cross the host cell membrane without disrupting it, while a large number of parasites, egressing simultaneously, rupture the membrane and the cell as a whole. These data suggest that invasion and egress share less similarities than previously believed. PMID- 19875236 TI - A trial on subcutaneous pedicle island flap for eyebrow reconstruction. AB - INTRODUCTION: Severe burn is a common problem affecting victim's eyebrows. This study aims to assess the effectiveness, complications and patients' satisfaction in two eyebrow reconstruction surgical methods. Up to now, many reconstruction methods, their specific advantages and complications have been introduced. This study compares a new method (subcutaneous pedicle island flap), which is scarcely discussed, with a standard method (superficial temporal artery island flap). METHOD: This is a clinical trial conducted during 2003-2005 at the Al' Zahra' Hospital. Forty patients with eyebrow defect due to burn injuries were selected by convenience sampling. They were allocated to two groups randomly. The control group underwent a surgery for 'superficial temporal artery island flap' and the case group for 'subcutaneous pedicle island flap'. Data were gathered using two questionnaires. The first one included demographic data, patient history and condition of the eyebrows prior to surgery, effectiveness of surgery and complications. The second was a smiley face visual scale for patient's satisfaction. Data analysis was done using SPSS software (version 12; SPSS Inc., Chicago, IL, USA). RESULT: Findings showed that in the control group, 80% were female of a mean age of 22 years (SD=6/30) and in the case group 75% were female, of a mean age of 21/80 years (SD=8/28). Fisher's exact test showed a significant difference between the type of surgery and hair-growth direction (p=0.003). In addition, Mann-Whitney U test showed a significant difference between the type of surgery and patient satisfaction (p=0.002). Analysis showed that there is no significant difference between the type of surgery and bleeding, congestion, flap necrosis, temporary hair loss in flap and donor-site alopecia (p>0.05). Surgeon's experience shows that surgery time and learning curve in the case group is lower than that in the control group. DISCUSSION: Subcutaneous pedicle island flap is an appropriate and easy method with good efficacy, lower complication and more reasonable and acceptable patient's satisfaction. Therefore, this method is recommended for burn patients with eyebrow defects. PMID- 19875237 TI - Systemic Pythium insidiosum in a pediatric burn patient. PMID- 19875238 TI - Vancomycin pharmacokinetics in patients with severe burn injuries. AB - Vancomycin is used in patients with severe burns and methicillin-resistant Staphylococcus aureus (MRSA) infection. This study investigated vancomycin pharmacokinetics in people with burns in comparison to people without burns and examined the factors contributing to pharmacokinetic variability. This was a retrospective, case-control study of hospitalised burns patients compared with a control patient cohort administered vancomycin without burn injury. Vancomycin pharmacokinetic parameters were determined using therapeutic drug monitoring data and a population pharmacokinetic modelling approach employing a two-compartment pharmacokinetic model. The impact of patient characteristics on vancomycin clearance was explored. Vancomycin clearance was significantly higher (p<0.001) in burns patients (5.9+/-3.1L/h, n=37) when compared to control patients (3.4+/ 1.8 L/h, n=33), as was estimated creatinine clearance, which was correlated to drug clearance in burns patients (r(2)=0.64). There was no significant change in volume of distribution between patient groups. The majority of patients received a dosing regimen of 1g twice daily, resulting in significantly (p=0.004) lower serum trough concentrations in patients with burns (median, 6.4 mg/L; range, 0.2 22.3mg/L) than control (median, 9.2mg/L; range, 4.0-29.8 mg/L). Higher clearance and lower serum vancomycin concentrations in people with severe burn may increase the risk of suboptimal bactericidal action and the development of resistance highlighting the need for dosage individualization. PMID- 19875239 TI - BurnEd: parental, psychological and social factors influencing a burn-injured child's return to education. AB - Childhood burns are painful and traumatic and impact the child and their family. For the child, part of the returning to wellness process involves successfully returning to school, a process in which parents play a vital role. This qualitative research aimed to examine how influential parental and other factors were in the return to school process. Data was collected through semi-structured interviews and was analysed using a social-constructivist Grounded Theory approach. The analysis revealed that parental confidence-in themselves, their children and their children's schools; role adaptation, skill acquisition and flexibility; and school receptivity, were pivotal in the return to school process. PMID- 19875240 TI - [Assessment of the contribution of the immunochromatographic pneumococcal urinary antigen test to the etiological diagnosis of pneumonia in hospitalized adults]. AB - AIM OF THE STUDY: To assess the usefulness and prescription practices of the Binax Now Streptococcus pneumoniae urinary antigen test in hospitalized adults. PATIENTS AND METHODS: The results of the pneumococcal urinary antigen tests (UAT) performed from January 2002 to September 2004 were related to that of microbiological cultures, and in positive patients to radiographic findings and C reactive protein (CRP) levels. The evolution of the number of prescriptions and positivity rate in 2007 versus 2002-2004 was analyzed. RESULTS: The pneumococcal UAT was positive in 32 of the 278 patients included from 2002 to 2004 (11.5%). Results were concordant with that of microbiological cultures in 90% of the 247 documented cases. Pneumococcal etiology was considered to be definite in 19 patients (isolation of S. pneumoniae from blood, 17 patients; or pleural fluid, two patients), of whom 15 had a positive UAT (sensitivity: 79%); to be probable in 22 patients (positive UAT, 17 patients and/or isolation of S. pneumoniae from respiratory samples, six patients), and was retained in 39 of the 41 patients (positive predictive value: 93.7%). CRP was greater than 100mg/L in 34 of 39 documented patients and lobar alveolar radiographic opacities observed in 25 of 28 documented patients. In 2007, the dramatic increase in the number of UAT prescriptions and the diversification of prescribing units were associated to a decreased positivity rate (8.1%). CONCLUSION: Whereas the pneumococcal UAT clearly increases etiological diagnosis, pneumococcal pneumonia cannot be ruled out if negative. Indications for its use need to be refined to improve the cost effectiveness of this test. PMID- 19875241 TI - [Evolution of antimicrobial resistance against Pseudomonas aeruginosa in a French university hospital between 2002 and 2006]. AB - AIM OF STUDY: Monitor evolution of antibiotic resistance of Pseudomonas aeruginosa from 2002 to 2006 in our hospital to optimize antibiotherapy. PATIENTS AND METHOD: The infections/colonizations with P. aeruginosa have been identified by the hospital's informatic database. Bacteriological samples realized 48hours after patient's admission was considered as nosocomial. A Cochran-Armitage test was conducted to assess the evolution of resistance. RESULTS: During this period, 2098 infections/colonizations with P. aeruginosa have been identified. Bacteriological samples (68.5%) were nosocomial. Among the beta-lactam antibiotics, ceftazidime and imipenem were the most active (R=16.8% and 15.2%, respectively), followed by piperacillin and piperacillin-tazobactam (R=24.8%, 18.4%, respectively). Amikacin and tobramycin were more active than gentamicin (R=19.9%; 22.2% and 40.6%, respectively). 28.9% of strains were resistant to ciprofloxacin. Nosocomial strains were significantly more resistant than non hospital strains: ceftazidime: 17.9% versus 14.2%, p=0.0346; ticarcillin clavulanic acid: 47.5% versus 39.6%, p=0.0009; piperacillin-tazobactam: 20.0% versus 14.8%, p=0.0046; ciprofloxacin: 30.7% versus 25.2%, p=0.0112. A significant increase in the resistance of nosocomial strains to ceftazidime, ticarcillin-clavulanic acid and piperacillin-tazobactam was noted. Resistance from non-hospital strains to fluoroquinolones, aminoglycosides, ceftazidime, piperacillin and ticarcillin-clavulanic acid decreased significantly. CONCLUSION: P. aeruginosa is a predominantly nosocomial microorganism. There is a decrease of resistance for non-hospital strains. But the resistance of nosocomial strains to antibiotics widely prescribed in hospital is worrying. PMID- 19875242 TI - [In vitro activity of daptomycin against strains isolated from diabetic foot ulcers]. AB - PURPOSE OF THE STUDY: The aim of this study was to evaluate the in vitro activity of daptomycin and other comparator agents against bacterial strains isolated from diabetic foot infections (DFI). PATIENTS AND METHODS: All diabetic patients hospitalized for a first episode of DFI (stage 2 to 4, according to the International Working Group of Diabetic Foot classification) were selected in Nimes University hospital between June 2006 to August 2007. MIC were determined using E-test strip (AB Biodisk) and custom broth microdilution panels against bacterial strains isolated from foot samples. RESULTS: Two hundred strains were studied. Daptomycin was active against 99.5% of all the strains especially Streptococcus sp. (100%), Enterococcus sp. (100%), coagulase-negative Staphylococcus (100%) and methicillin-susceptible Staphylococcus aureus (100%). Exclusively, one methicillin-resistant S. aureus strain was not covered by this antibiotic. CONCLUSIONS: Daptomycin, a new broad spectrum antimicrobial agent against Gram-positive cocci, is qualified to belong to the therapeutic arsenal package of complicated skin and soft tissue infections in diabetic patients after microbial documentation. PMID- 19875243 TI - [Comparison between the LightCycler CMV Quant Kit (Roche Diagnostics) with a standardized in-house Taqman assay for cytomegalovirus blood viral load quantification]. AB - The broad use of cytomegalovirus (CMV) viral load quantification in blood to follow immunosuppressed patients need standardized assays. Choice of whole blood allows follow-up for several viruses and simplifies pretreatment and storage of samples. METHODS: We therefore evaluated the LightCycler CMV Quant Kit (Roche Diagnostics) assay on whole blood after a manual extraction (High Pure viral nucleic acid kit, Roche Diagnostics), using as a reference an in-house Taqman assay (LC1UL83) which has been validated in various clinical situations. A panel obtained by serial dilutions of a virion stock in CMV whole blood, a commercial plasma quality control (VQC, Argene, France) crude or diluted in whole blood, infected cells extracts and 46 clinical samples from transplanted patients were tested simultaneously by both techniques. RESULTS: For plasma quality controls, both PCR assays are correlated VQC (R(2)=0.93). On whole blood or infected cells dilutions, correlation shows an overestimation by the LC1UL83 assay (mean 1.2 log copies/ml) over 3 log though R(2)=0.94. Results with CMV Quant Kit are closer to expected values. Results on clinical samples are close to quality controls with a lower variation of quantification (0.76 log copies/ml). CONCLUSION: CMV Quant Kit performs well when compared with a clinically validated PCR. Quality control results showed discrepancies between plasma and whole blood, demonstrating the need for whole blood standardized panels to compare the methods. This underlines the need to follow a patient with the same technique during his follow-up. PMID- 19875244 TI - [Incidence of hospital-acquired and community-acquired bloodstream infections in the University of Strasbourg Hospitals, France, between 2005 and 2007]. AB - OBJECTIVE: To follow the evolution of incidence of the main feature of bloodstream infections identified in a french hospital between 2005 and 2007. METHODS: We included all the patients hospitalised during three times three-month periods, according to the protocol given by the coordination center against nosocomial infections. For every positive blood culture, we collected clinical and microbiological datas. RESULTS: Hospital-acquired bacteremias are the most frequent with an incidence rate between 0.996 to 1.31 per thousand days of hospitalisation. The population is mainly over 50 years old. The main sources of infection are central catheter, digestive and urinary tracts. Organisms causing the majority of nosocomial bloodstream infections are coagulase-negative staphylococci, Staphylococcus aureus and Escherichia coli. The mortality rate during the first week varies from 16% in 2005 to 8% in 2007. Community-acquired bloodstream infections represent 28% of all episodes, and affect people who are over 70 years old. The main sources of infection are urinary, digestive and pulmonary. Escherichia coli, Staphylococcus aureus and Streptococcus pneumoniae are most frequently isolated. The mortality rate during the first week varies from 3.7 to 9.8% according to the year of study. CONCLUSION: This annual investigation enables us to measure the infection risk level in our hospital, to identify the main sources implied and to create targeted actions to prevent nosocomial bloodstream infections. PMID- 19875245 TI - [Management of the Legionella-link risk in a multicentre area's hospital: lessons learned of a six-year experience]. AB - To reduce the Legionella-linked risk in the several sites of Sud-Francilien Hospital, following a hospital-acquired legionellosis case, a multidisciplinary working group performed an action plan monitored through Legionella pneumophila counts in hot water supply. From 2003 to the first half year 2009, positive points for Legionella pneumophila in the main sites of the hospital decreased from 85.71 to 28.00%, representing a significant reduction of 67.33%. Similar results were observed for three of the four establishments, whereas the last did not describe a pronounced reduction of Legionella pneumophila counts and showed constantly serogroup 1 strains. During this period, investigations of additional cases of legionellosis demonstrated a nosocomial transmission in one case in this last site. Multidisciplinary mobilization in management of Legionella-linked risk contributed to these results. PMID- 19875246 TI - [Community- and non-community-acquired bacteremia: correlation between empiric antimicrobial therapy and susceptibility of micro-organisms isolated during 2007 in the Ile-de-France microbiologists network]. AB - AIM OF THE STUDY: To estimate the percentage of empirical treatments adapted in the bloodstream infections of community and not community origin and to determine the main circumstances in which this initial treatment is not adapted. PATIENTS AND METHODS: Surveillance of bloodstream infections from the laboratories of microbiology of the eight hospitals of the Ile-de-France network, during year 2007. The study concerned the patients hospitalised in medicine, surgery, obstetrics, intensive care, following care and rehabilitation, day hospitalisation, hospitalisation at home, who presented one or several episodes of bloodstream infections. RESULTS: During year 2007, 2013 bloodstream infections were analysed. Only 63.9% of bloodstream infections had an adapted initial antibiotic treatment. Among this proportion of bloodstream infections, an adapted empirical treatment concerned mainly the community episodes, the urinary tract, the pulmonary tract, or maternal-foetal episodes and the maternity ward and pediatrics. The percentage of adapted treatments was superior in the bloodstream infections where were isolated an Enterobacteriaceae, Streptococcus pneumoniae or other streptococci. On the contrary, only a quarter of bloodstream infections due to an Enterobacteriaceae producing BLSE or to a MRSA had received an adapted empirical treatment. CONCLUSION: Only two-thirds of the patients developing a bloodstream infection received an adapted initial antibiotic treatment. This proportion was even lower when it was not about a community origin, in spite of the frequent administration of several anti-infectious molecules or with wide spectrum. PMID- 19875247 TI - [High prevalence of community- and hospital-acquired infections of methicillin resistant Staphylococcus aureus containing Panton-Valentine leukocidin gene in Algiers]. AB - OBJECTIVES: To determine the prevalence of community acquired and hospital methicillin-resistant Staphylococcus aureus (S. aureus) infections and the Panton Valentine leukocidin. PATIENTS AND METHODS: Seven hundred S. aureus strains were collected during 21 months period in Mustapha Bacha hospital. Bacterial identification was based on standard methods and susceptibilities were tested by disk diffusion method. Molecular study (toxins, mecA gene and agr alleles) were determined for 221 S. aureus isolates by multiplex PCR. RESULTS: The global MRSA prevalence was 42 %, 35 % in the community and 49 % in hospital setting. The frequency of strains containing PVL genes (PVL+) was 36 %, their molecular profile was: agr3, mecA+, etd, edin, which correspond to the C-MRSA major ST80 clone in Europe and the Maghreb. The H-MRSA-PVL+ were multidrug resistant. Among the MSSA, 13 strains contained the tst gene and five contained the exfoliatine genes ETA and ETB. CONCLUSION: Our results show a high rate of MRSA-PVL+ in the community and the hospital setting. The H-MRSA-PVL+ were multidrug resistant complicating their antibiotic treatment options. PMID- 19875248 TI - [Etiopathological factors of hepatocellular carcinoma in Bangui, Central African Republic: clinical, biological characteristics and virological aspects of patients]. AB - OBJECTIVES: To describe clinical, biological characteristics and virological aspects of patients with hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Sera obtained from consent patients with clinical suspicion of HCC. Routine biochemical tests and serological markers of hepatitis B virus (HBV), hepatitis D virus (HDV) and hepatitis C virus (HCV) were searched. A hepatic ultrasound scan was realized and, when a suspected mass lesion was observed, ultrasonographic guided fine needle aspiration of the hepatic mass lesion was made to ascertain the diagnosis of HCC. RESULTS: One hundred and seventy-five sera were collected from 99 men and 76 women. Approximately 96.6% (169/175) of them had previous contact with HBV. HBs surface antigen was positive in 41% (69/169) of whom 53.6% (37/69) were co-infected by the HDV. Three patients (1.71%=3/175) were positive for anti-HCV antibodies. The other three patients (1.71%=3/175) did not present any markers for HBV or HCV. At the time of diagnosis, right upper quadrant pain, hepatomegaly, cachexia, were present in all patients. An increase in serum transaminases (70%), high bilirubin concentrations (40%), high AFP levels (40%) and low prothrombin levels (52%) were the most frequent biological abnormalities. Only 17 guided fine needle aspirations of mass lesions were realized. The diagnosis of HCC was confirmed by cytopathological examination for 14 of them. CONCLUSIONS: HCC is a frequent pathology in the Central African Republic (CAR). According to the ultrasound imaging data, patients consult at terminal stage of the disease. This study confirms also the association between HBV and HCC in CAR. Moreover, in 26.5% of patients HDV is associated with severe forms of the disease. PMID- 19875249 TI - Q Fever. AB - Q fever is a zoonotic disease caused by the ubiquitous pathogen Coxiella burnetii responsible for acute and chronic clinical manifestations. Farm animals and pets are the main reservoirs of infection, and transmission to human beings is mainly accomplished through inhalation of contaminated aerosols. This illness is associated with a wide clinical spectrum, from asymptomatic or mildly symptomatic seroconversion to fatal disease. In humans Q fever can manifest as an acute disease (mainly as a self-limited febrile illness, pneumonia, or hepatitis) or as a chronic disease (mainly endocarditis), especially in patients with previous valvulopathy and to a lesser extent in immunocompromised hosts and in pregnant women. In contrast in animals, Q fever is in most cases, strikingly asymptomatic. The definite diagnosis of Q fever is made based on a significant increase in serum antibody titers, the determination of which often requires considerable time, and therefore patients must be monitored for a certain period. The treatment is effective and well tolerated, but must be adapted to the acute or chronic pattern with the tetracyclines to be considered the mainstay of antibiotic therapy. Several actions have been proposed to prevent and reduce the animal and environmental contamination. Vaccination of animals in infected flocks, as well as in uninfected ones close to them, with an efficient vaccine can prevent abortions and shedding of the bacteria. PMID- 19875250 TI - Modelling the spread of Bovine Viral Diarrhoea Virus (BVDV) in a managed metapopulation of cattle herds. AB - In numerous epidemiological models developed within a metapopulation framework, it is assumed that a single infected individual introduced into a patch infects the whole patch and that the proportion of infected individuals into infected patches is consistent over time and among patches. If this approach is relevant for rapidly spreading pathogens, it is less appropriate for moderately spreading pathogens, like the Bovine Viral Diarrhoea Virus (BVDV), characterized by a variability in within-patch prevalence. Our objective is to study the respective influence of neighbouring relationships and animal movements on the spread of BVDV in a managed metapopulation of 100 cattle herds. Infection dynamics is represented by two coupled stochastic compartmental models in discrete-time: a within-herd and a between-herd models. Animal movements are mechanistically modelled. They largely influence the BVDV persistence, the prevalence in infected herds and the epidemic size. Neighbouring relationships only influence epidemic size. Whatever the neighbouring relationships, the infection does not persist in the metapopulation without animal movement between herds. The proposed model can be easily adapted for different herd contact structures. PMID- 19875251 TI - Characterisation of a new infectious full-length cDNA clone of BVDV genotype 2 and generation of virus mutants. AB - Based on their genomic sequences, two genotypes of Bovine viral diarrhea virus (BVDV) can be differentiated, BVDV type 1 (BVDV-1) and BVDV type 2 (BVDV-2). The complete genomic sequence of the highly virulent BVDV-2 strain 890 was cloned as cDNA to establish the infectious cDNA clone p890FL. In vitro-synthesised full length RNA of p890FL was transfected into bovine cells and infectious virus could be recovered (v890FL). In vitro, recombinant v890FL showed similar growth characteristics as wild type virus v890WT. However, infection experiments in calves revealed an attenuation of recombinant v890FL in comparison to the parental isolate. Both leukocytopenia and fever were less pronounced in v890FL infected calves. Nevertheless, viremia and virus shedding were comparable between recombinant and parental BVDV 890. Furthermore, mutants with partial deletions of the genomic region encoding for the autoprotease N(pro) (p890DeltaN(pro)) or the capsid protein (p890DeltaC) were constructed and characterised. In order to generate pseudovirions, replicon p890DeltaC was efficiently trans-complemented on a helper cell line. In summary, the newly developed construct p890FL represents the first infectious full-length cDNA clone for the BVDV-2 strain 890 and offers a useful tool for further studies on the pathogenesis of BVDV-2 and the development of novel recombinant BVDV-2 specific vaccine candidates. PMID- 19875252 TI - Characterisation of experimental infections of domestic pigs with genotype 2.1 and 3.3 isolates of classical swine fever virus. AB - The early identification of classical swine fever epizootics is hampered by difficulties in recognising early signs of infection, due to a lack of specific clinical signs. In addition many textbook descriptions of CSF are based on observations of disease caused by historic, mainly genotype 1, strains. Our objective was to improve our knowledge of the diverse range of signs that different CSFV strains can cause by characterising the experimental infection of domestic pigs with both a recent strain of CSFV and a divergent strain. Conventional pigs were inoculated with a genotype 2.1 isolate, that caused an outbreak in the UK in 2000, and a genotype 3.3 strain that is genetically divergent from European strains. This latter strain is also antigenically distinct as it is only poorly recognised by the CSFV-specific monoclonal antibody, WH303. Transmission was monitored by use of in-contact animals. Clinical, virological and haematological parameters were observed and an extended macro- and histopathological scoring system allowed detailed characterisation of pathological lesions. Infection with the genotype 2.1 isolate resulted in a similar outcome to other recent genotype 2 European strains, whereas the genotype 3.3 strain produced fewer and delayed clinical signs, notably with little fever. This strain would therefore be particularly difficult to detect in the early stages of infection and highlights the importance of encouraging early submission of samples for laboratory diagnosis. As representatives of recent and divergent CSFV isolates, these strains are good candidates to study the pathogenesis of current CSFV isolates and as challenge models for vaccine development. PMID- 19875253 TI - Novel BVDV-2 mutants as new candidates for modified-live vaccines. AB - Protection against Bovine viral diarrhea virus (BVDV) type 2 infection of commercially available vaccines is often limited due to marked genetic and antigenic differences between BVDV types 1 (BVDV-1) and 2 (BVDV-2). Therefore, the immunogenicity of selected BVDV-1 and BVDV-2 mutants derived from infectious full-length cDNA clones and their use as modified-live vaccine candidates against challenge infection with a virulent heterologous BVDV-2 field isolate were investigated. Deletion mutants of BVDV-1 and BVDV-2 lacking a part of the N(pro) gene (BVDV-1DeltaN(pro)/BVDV-2DeltaN(pro)) were used as well as a packaged replicon with a deletion in the structural core protein encoding region (BVDV 2DeltaC-pseudovirions). The 25 calves used in this vaccination/challenge trial were allocated in five groups (n=5/group). One group received BVDV-1DeltaN(pro) (1 shot), one group BVDV-2DeltaN(pro) (1 shot), one group received both, BVDV 1DeltaN(pro) and BVDV-2DeltaN(pro) (1 shot), and one group was immunised with the BVDV-2DeltaC-pseudovirions (2 shots). The fifth group served as non-vaccinated control group. All groups were challenged intranasally with the BVDV-2 strain HI916 and monitored for signs of clinical disease, virus shedding and viremia. All tested BVDV vaccine candidates markedly reduced the outcome of the heterologous virulent BVDV-2 challenge infection showing graduated protective effects. The BVDV-2DeltaN(pro) mutant was able to induce complete protection and a "sterile immunity" upon challenge. Thus it represents a promising candidate for an efficacious future live vaccine. PMID- 19875255 TI - The first ovulation of the breeding season in the mare: the effect of progesterone priming on pregnancy rate and breeding management (hCG response rate and number of services per cycle and mare). AB - The mare is a seasonally polyestrus breeder. In early spring, the mare enters a "transition period" between the anovulatory season and the first ovulation of the year. This period is characterized by irregular estrus cycles and high incidence of regressing dominant follicles. There is a belief that pregnancy rates resulting from the first ovulation of the season is lower than in subsequent ovulations, however this has never been studied critically. Progestagens are often used as an aid to manage the transition period. The objective of this study was to compare pregnancy rates of mares from the first ovulation of the year with: (a) mares on their second or subsequent ovulations and (b) mares with progesterone-primed first ovulations. A total of 136 thoroughbred mares were used in the study. The mares were classified into four groups: (1) mares mated at the first ovulation of the year (n=46); (2) mares mated in the first ovulation of the year after removal of a previously inserted progesterone device (CIDR) (n=29); (3) mares mated at the second or more ovulations of the year after prostaglandin induced estrus (n=50); and (4) mares mated after spontaneous return to estrus (n=11). Pregnancy rates were not different in any of the groups studied: 65.2, 75.9, 76 and 72.7 for groups 1-4 respectively (P>0.05). Group 1 mares had the lowest response to hCG treatment which resulted in the highest number of services per cycle (P<0.05). In conclusion, although the use of progesterone priming did not affect pregnancy rates, it did improve the breeding management of transitional mares by enhancing the hCG response rate and consequently decreasing the number of services per cycle. PMID- 19875254 TI - Infertility, infertility treatment, and mixed-handedness in children. AB - BACKGROUND: Mixed-handedness, which may reflect atypical brain laterality, has been linked to a number of medical conditions as well as prenatal stress. AIMS: The aim of the study was to examine whether infertility or infertility treatment was associated with an increased risk of mixed-handedness in children. STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES: We used data from three population-based birth cohorts in Denmark: the Aalborg-Odense Birth Cohort (1984-1987), the Aarhus Birth Cohort (1990-1992) and the Danish National Birth Cohort (1996-2002) (N=7728, 5720 and 29486, respectively). Data on time to pregnancy and infertility treatment were collected during pregnancy. Handedness was reported in a follow-up questionnaire when the children were at least 7years old. Children were categorized as mixed-handed if their mothers reported that they used both hands equally. RESULTS: Children born after infertility treatment, particularly intrauterine insemination, had a higher risk of being mixed-handed compared to children of fertile couples with a time to pregnancy 0.1) in CAD detection of cancers in dense breasts 90% (53/59) versus non-dense breasts 91% (62/68). There was statistical difference (p < 0.05) in CAD detection of cancers that appeared mammographically as microcalcifications only versus other mammographic manifestations. CAD detected 100% (44/44) of cancers manifesting as microcalcifications, 89% (47/53) as no-calcified masses or asymmetries, 88% (14/16) as masses with associated calcifications, and 71% (10/14) as architectural distortions. CAD sensitivity for cancers 1-10mm was 84% (38/45); 11 20mm 93% (55/59); and >20mm 97% (22/23). CONCLUSION: CAD applied to FFDM showed 100% sensitivity in identifying cancers manifesting as microcalcifications only and high sensitivity 86% (71/83) for other mammographic appearances of cancer. Sensitivity is influenced by lesion size. CAD in FFDM is an adjunct helping radiologist in early detection of breast cancers. PMID- 19875261 TI - Interest of uterine artery embolization with gelatin sponge particles prior to myomectomy for large and/or multiple fibroids. AB - PURPOSE: To evaluate the efficacy of pre-myomectomy uterine artery embolization with gelatin sponge particles to reduce operative blood loss and facilitate removal of fibroids. MATERIALS AND METHODS: This retrospective study included 33 women (mean age, 36 years; range, 24-45 years), of whom at least 18 wished to preserve fertility. They presented with at least one large myoma (mean diameter, 90 mm; range, 50-150 mm) and had undergone preoperative uterine artery embolization with resorbable gelatin sponge by unilateral femoral approach between December 2001 and November 2008. Clinical, radiological and surgical data were available for all patients. Mean haemoglobin levels before and after surgery were compared with Student's t-test. RESULTS: No complication or technical failure of embolization occurred. The myomectomies were performed during laparotomy (25 cases) or laparoscopy (8 cases). Dissection of fibroids was easier (mean, 3 per patient; range, 1-11), with a mean operating time of 108+/-50 min (range, 30-260 min). Bloodless surgery was the rule with a mean estimated peroperative blood loss of 147+/-249 mL (range, 0-800 mL). Mean pre-(12.9+/ 1.3g/dL) and post-therapeutic (11.4+/-1.2g/dL) haemoglobin levels were not statistically different (p>0.05). There was no need for blood transfusion. None of the patients required hysterectomy. The mean duration of hospital stay was 7.5+/-1.3 days (range, 3-12 days). CONCLUSION: Preoperative uterine artery embolization is effective in reducing intraoperative blood loss and improves the chances of performing conservative surgery. It should be considered a useful adjunct to myomectomy in women at high hemorrhagic risk or who refuse blood transfusion. PMID- 19875262 TI - A rapid and sensitive LC-ESI-MS/MS method for detection and quantitation of methylprednisolone and methylprednisolone acetate in rat plasma after intra articular administration. AB - A rapid, sensitive and specific liquid chromatography-electrospray-tandem mass spectrometric (LC-ESI-MS/MS) method for the simultaneous detection and quantitation of methylprednisolone acetate (MPA) and methylprednisolone (MP) in rat plasma, using a triple-stage quadrupole, has been developed and validated. MP D(2) was used as internal standard (IS) and acetonitrile was added to plasma samples for protein precipitation. After extraction with dichloromethane, the analytes were separated on a C-12 reversed-phase column by isocratic elution (6min at a flow rate 0.2mLmin(-1)) with water containing 0.01% formic acid (A) and acetonitrile (B) (50:50, v/v). Quantitation was performed in positive ion multiple reaction monitoring (MRM) mode by applying the following precursor-to product ion transitions: MPA m/z 417-->135+161+253; MP m/z 375-->135+161+253; IS m/z 377-->135+161+253. The method, validated over the concentration range 6 600ngmL(-1), has been shown to meet the current requirements of bioananalytical validation, providing satisfactory results in terms of linearity, recovery, intra day and inter-day precision and accuracy. The lower limit of quantitation (LLOQ) was 6ngmL(-1) for both the analytes (0.080 and 0.072pmol injected for MP and MPA, respectively). The method was successfully applied to monitor the plasma levels of MPA and MP following intra-articular (IA) injections of a low MPA (Depo Medrol((R))) dose in rats. PMID- 19875263 TI - Capillary electrophoresis analysis of the degradation of the aspartyl tripeptide Phe-Asp-GlyOH at pH 2.0 and 7.4 under forced conditions. AB - The degradation of the tripeptide l-Phe-alpha-l-Asp-GlyOH was studied at 80 degrees C and pH 2.0 and 7.4 by capillary electrophoresis. Separation of most known as well as unknown degradation products was achieved in a 50mM sodium phosphate buffer, pH 3.0. The diastereomers l-Phe-alpha-l-Asp-GlyOH/l-Phe-alpha-d Asp-GlyOH could only be separated upon addition of 16mg/ml carboxymethyl-beta cyclodextrin and 5% acetonitrile to the background electrolyte. Compound identification was performed by capillary electrophoresis-electrospray ionization mass spectrometry. In addition to Asp isomerization and epimerization products as well as hydrolysis products four diketopiperazine derivatives were identified. Moreover, two degradation products were observed containing the amino acids Asp, Gly and Phe but the unequivocal assignment could not be accomplished based on the mass spectra. Following validation with regard to linearity, range, limit of detection, limit of quantitation and precision the assay was applied to the analysis of the incubation solutions. While peptide backbone hydrolysis dominated at pH 2.0, isomerization and enantiomerization yielding beta-Asp and d-Asp peptides as well as cyclization to diketopiperazine derivatives were observed at pH 7.4. The diketopiperazines were the dominant reaction products amounting to about 85% of the compounds detected after the maximal incubation time of 240h. A kinetic model was used to fit the concentration versus time data. PMID- 19875264 TI - Validation of a method for the quantitation of ghrelin and unacylated ghrelin by HPLC. AB - An HPLC/UV method was first optimized for the separation and quantitation of human acylated and unacylated (or des-acyl) ghrelin from aqueous solutions. This method was validated by an original approach using accuracy profiles based on tolerance intervals for the total error measurement. The concentration range that achieved adequate accuracy extended from 1.85 to 59.30microM and 1.93 to 61.60microM for acylated and unacylated ghrelin, respectively. Then, optimal temperature, pH and buffer for sample storage were determined. Unacylated ghrelin was found to be stable in all conditions tested. At 37 degrees C acylated ghrelin was stable at pH 4 but unstable at pH 7.4, the main degradation product was unacylated ghrelin. Finally, this validated HPLC/UV method was used to evaluate the binding of acylated and unacylated ghrelin to liposomes. PMID- 19875265 TI - Simultaneous determination of nine pyrethroids in indoor insecticide products by capillary gas chromatography. AB - A gas chromatographic method was developed for simultaneous determination of nine pyrethroids (permethrin, transallethrin, beta-cypermethrin, prallethrin, tetramethrin, transfluthrin, cyphenothrin, phenothrin, imiprothrin) in indoor insecticide products using dibutyl phthalate and iso-octyl phthalate as two internal standards. Parameters affecting the extraction and separation efficiency were investigated. Good linear fit curves were obtained in a range of 0.4-900mg/l with correlation coefficients >0.999. The proposed method was successfully applied for the determination of pyrethroids in mosquito coils and two aerosol products. The recovery of transallethrin in mosquito coils at three spiked levels was 96.8% with relative standard deviation less than 2.7%. The recoveries of transallethrin, tetramethrin, permethrin and cyphenothrin in aerosol products were 97.2%, 96.4%, 94.3%, 94.6% with RSD less than 2.3%, 2.8%, 3.1%, 2.9%, respectively. PMID- 19875266 TI - The effect of preoperative nutritional face-to-face counseling about child's fasting on parental knowledge, preoperative need-for-information, and anxiety, in pediatric ambulatory tonsillectomy. AB - OBJECTIVE: The objective of this study was to define how preoperative nutritional face-to-face counseling on child's fasting affects parental knowledge, preoperative need-for-information, and anxiety, in pediatric ambulatory tonsillectomy. METHODS: The participants in the prospective, randomly allocated study were parents (intervention 62/control 62) with children (4-10 years) admitted for ambulatory tonsillectomy. Data were collected by the knowledge test designed for the study and with The Amsterdam preoperative anxiety and information scale (APAIS). The intervention group was invited to a preoperative visit to receive written and verbal face-to-face counseling. They were initiated into the child's active preoperative nutrition. The parents of the control group received current information without face-to-face counseling. RESULTS: The parents followed the instructions. Their knowledge about the child's fast increased (p=0.003), and need-for-information and anxiety decreased (p<0.0001) significantly. CONCLUSION: The preoperative face-to-face counseling with written information improves parental knowledge about the child's fasting and active preoperative nutrition, and relieves their need-for-information and anxiety. PRACTICE IMPLICATIONS: The primary responsibility remains with the health care professionals when the active preoperative nutrition of the child and counseling on it are introduced into nursing practice. PMID- 19875267 TI - WITHDRAWN: Natural polyphenols modify trace element status and improve clinical symptoms of attention-deficit hyperactivity disorder. AB - This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy. PMID- 19875268 TI - Pharmacogenetic testing is of limited utility for predicting analgesic response to morphine. PMID- 19875269 TI - How should we conduct and interpret phase III clinical trials in palliative care? PMID- 19875270 TI - Effects of different variations of mental and physical practice on sport skill learning in adolescents with mental retardation. AB - The purpose of this study was to investigate the effect of five variations of imagery and physical practice on learning of Basketball free throws in adolescents with mental retardation (AWMR). Forty AWMR were randomly assigned to five groups and performed a variation of practice: physical practice, mental practice, physical practice followed by mental practice, mental practice followed by physical practice, and no practice. The groups exercised the task for 24 sessions. Following training, posttest and retention test were taken. All variations of practice resulted in performance improvement, yet the mental practice followed by physical practice resulted in better improvement. The results suggest that mental practice associated with physical practice results in an outstanding performance improvement in AWMR. PMID- 19875271 TI - Challenges in the validation of triage systems at emergency departments. AB - OBJECTIVES: Triage systems, developed by consensus of experts and based on decision rules, are typically not validated. The objective is to discuss the challenges to evaluate the reliability and validity of triage systems. STUDY DESIGN AND SETTING: Theoretical-conceptual approach to validate triage systems. RESULTS: The consensus-based triage systems have to be applied to a broad population with a variety of signs and symptoms. For the individual patient specific decision, rules are used and the outcome measure is, typically, one of five prognosis-specific urgency categories. In contrast, prediction rules in diagnostic research are developed for a narrow specific subpopulation and based on a combination of parameters to predict presence of a specific diagnosis. Reliability is based on case scenario and simultaneous triage studies. The first step in triage validation is to decide on the best proxy for prognosis, "the reference standard" for the urgency classification. The next step is modification of the triage decision rules, including a multivariate approach. The final step is the validation in different settings and to evaluate the impact in clinical practice. CONCLUSION: Triage should be viewed as diagnostic research and would benefit if it would use the available methodology in diagnostic research. PMID- 19875272 TI - Effects of repeated risperidone exposure on serotonin receptor subtypes in developing rats. AB - Risperidone is an atypical antipsychotic drug that is widely prescribed to young patients with different psychotic disorders. The long-term effects of this antipsychotic agent on neuronal receptors in developing brain remain unclear and require further investigation. In this study, we examined the effects of long term treatment of risperidone on two serotonin receptor subtypes in brain regions of juvenile rat. Levels of 5-HT(1A) and 5-HT(2A) receptors in forebrain regions of juvenile rats were quantified after 3 weeks of treatment with three different doses of risperidone (0.3, 1.0 and 3.0mg/kg). Findings were compared to previously reported changes in 5-HT receptors after risperidone treatment (3.0mg/kg) in adult rat brain. The three doses of risperidone selectively and dose-dependently increased levels of 5-HT(1A) receptors in medial-prefrontal and dorsolateral-frontal cortices of juvenile animals. The higher doses (1.0 and 3.0mg/kg) of risperidone also increased 5-HT(1A) receptor binding in hippocampal CA(1) region of juvenile but not adult rats. In contrast, the three doses of risperidone significantly reduced 5-HT(2A) labeling in medial-prefrontal and dorsolateral-frontal cortices in juvenile as well as in adult animals in an equipotent fashion. 5-HT(1A) and 5-HT(2A) receptors in other forebrain regions were not altered by repeated risperidone treatment. These findings indicate that there are differential effects of risperidone on 5-HT(1A) and 5-HT(2A) receptors in juvenile animals, and that the 5-HT system in developing animals is more sensitive than adults to the long-term effects of risperidone. PMID- 19875273 TI - Secure construction of k-unlinkable patient records from distributed providers. AB - OBJECTIVES: Healthcare organizations must adopt measures to uphold their patients' right to anonymity when sharing sensitive records, such as DNA sequences, to publicly accessible databanks. This is often achieved by suppressing patient identifiable information; however, such a practice is insufficient because the same organizations may disclose identified patient information, devoid of the sensitive information, for other purposes and patients' organization-visit patterns, or trails, can re-identify records to the identities from which they were derived. There exist various algorithms that healthcare organizations can apply to ascertain when a patient's record is susceptible to trail re-identification, but they require organizations to exchange information regarding the identities of their patients prior to data protection certification. In this paper, we introduce an algorithmic approach to formally thwart trail re-identification in a secure setting. METHODS AND MATERIALS: We present a framework that allows data holders to securely collaborate through a third party. In doing so, healthcare organizations keep all sensitive information in an encrypted state until the third party certifies that the data to be disclosed satisfies a formal data protection model. The model adopted for this work is an extended form of k-unlinkability, a protection model that, until this work, was applied in a non-secure setting only. Given the framework and protection model, we develop an algorithm to generate data that satisfies the protection model. In doing so, we enable healthcare organizations to prevent trail re-identification without revealing identified information. RESULTS: Theoretically, we prove that the proposed data protection model does not leak information, even in the context of an organization's prior knowledge. Empirically, we use real world hospital discharge records to demonstrate that, while the secure protocol induces additional suppression of patient information in comparison to an existing non-secure approach, the quantity of data disclosed by the secure protocol remains substantial. For instance, in a population of over 7700 sickle cell anemia patients, the non-secure protocol discloses 99.48% of DNA records whereas the secure protocol permits the disclosure of 99.41%. CONCLUSIONS: Our results demonstrate healthcare organizations can collaborate to disclose significant quantities of personal biomedical data without violating their anonymity in the process. PMID- 19875274 TI - The prevalence of human papillomavirus type 58 in Chinese patients with cervical carcinoma and its influence on survival. AB - AIMS: To assess the prevalence of human papillomavirus (HPV) type-specific infections and its influence on prognosis and survival rate of cervical cancer patients treated with radiotherapy alone or in combination with chemotherapy or hyperthermotherapy or both. MATERIALS AND METHODS: During 1993 and 1994, 120 patients with cervical cancer were consecutively assigned into four therapeutic modalities. One hundred and eight formalin-fixed and paraffin-embedded tissue samples available at the time of this study were subjected to DNA extraction. The DNA was analysed for the presence of HPV and HPV type-specific infections with polymerase chain reaction. The experimental data were co-analysed with the follow up data to evaluate prognosis and survival in relation to the HPV infection and treatment. RESULTS: All samples were found to be positive for HPV; 32.40% (95% confidence interval 23.72-42.09) of samples were HPV 16 single positive, 16.67% (95% confidence interval 10.19-25.06) were HPV 58 single positive, 34.26% (95% confidence interval 25.4-44.01) were HPV 16/58 double positive and 16.67% (95% confidence interval 10.19-25.06) were positive for other HPV types. The 5-year survival rates were 88.89, 80.0, 67.57 and 61.11% in patients with HPV 58 single positive, HPV 16 single positive, HPV 16/58 double positive, and other HPV types, respectively (P=0.18), irrespective of the treatment modalities. Univariate Cox regression analysis results showed that compared with the HPV 16 single positive group, the relative risk of death was high in the HPV 16/58 double positive group (hazard ratio 1.81, 95% confidence interval 0.71-4.60) and the other HPV types group (hazard ratio 2.09, 95% confidence interval 0.73-5.96), whereas it was lower in the HPV 58 single positive group (hazard ratio 0.53, 95% confidence interval 0.11-2.56), but this was not statistically significant (P=0.43). All results remained statistically non-significant after adjustment for age and tumour stage with multivariate Cox regression. No apparent differences were observed in the survival rates among the four groups with regard to the treatment protocols. CONCLUSION: No effect was seen of either treatment protocols or HPV type on survival, except for a slightly high survival in HPV 58 single-infected patients, which was statistically non-significant. PMID- 19875275 TI - Treatment of aggressive fibromatosis: the experience of a single institution. AB - AIMS: Aggressive fibromatosis is a locally aggressive infiltrative low-grade tumour, although pathologically benign, and it does not metastasise, yet it can cause serious local distressing symptoms by virtue of local destruction and impairment of local function. The aim of this study was to emphasise the role of radiotherapy and adequate surgery in the treatment of fibromatosis in patients presenting with newly diagnosed or recurrent disease and to analyse our treatment results over 15 years for this rare tumour type. MATERIALS AND METHODS: Fifty four patients with confirmed diagnosis of aggressive fibromatosis treated at King Faisal Specialist Hospital between 1990 and 2006 were identified from our local cancer registry. Forty-seven patients had surgery: complete resection (R0) in 20 patients, incomplete surgery (R1/2) in 27 patients, and seven patients had biopsy only. Forty-five patients were treated with radiotherapy: 38 patients were treated with postoperative radiotherapy, three patients were treated with preoperative radiotherapy and four patients had radiotherapy as the only treatment. The radiotherapy dose ranged between 45 and 60Gy (median 50.4Gy). Three patients did not receive any form of treatment apart from biopsy, but were still included in the final analysis. RESULTS: Fifty-two per cent (28/54 patients) of our patient population had tumour recurrence when first presented to King Faisal Specialist Hospital. The median age was 29.5 years (range 2-63 years). The most common site of involvement was the extremities (28 patients). Among the 54 patients (with primary and recurrent presentation) there were 10 local recurrences, all of which were within the original primary site. The 5-year progression-free survival and overall survival rates for the whole group were 75 and 95%, respectively. Univariate and multivariate Cox regression analysis showed that the depth of invasion significantly affected progression-free survival. CONCLUSION: Aggressive fibromatosis is effectively treated with surgery and postoperative radiotherapy. Patients first presenting with tumour recurrence may still have local tumour control comparable with newly diagnosed patients. PMID- 19875276 TI - Transcriptome analysis of the venom glands of the Chinese wolf spider Lycosa singoriensis. AB - The wolf spider Lycosa singoriensis is a hunting spider with a widespread distribution in northwest China. The venom gland of spiders, which is a very specialized secretory tissue, can secrete abundant and complex toxin components. To extensively examine the transcripts expressed in the venom glands of L. singoriensis, we generated 833 expressed sequence tags (ESTs) from a directional cDNA library. Toxin-like sequences account for 69.1% of these ESTs, 17.3% are similar to cellular transcripts and 13.6% have no significant similarity to any known sequences. Here, we identified 223 novel toxin-like sequences, which can be classified into six different superfamilies; that means a novel potential source of ligands for varied ion channels was discovered. With the aid of Gene Ontology terms and homology to eukaryotic orthologous groups, the annotation of cellular transcripts revealed some cellular processes important for the toxin secretion of venom glands including protein synthesis, protein folding, tuned post translational processing and trafficking, etc. PMID- 19875277 TI - Additive effects of transdermal tulobuterol to inhaled tiotropium in patients with COPD. AB - BACKGROUND: The current mainstream treatment for COPD is bronchodilators alone or in combination. The effects of a beta(2)-agonist, tulobuterol, administered transdermally, have been reported to last for 24h. However, there are no reports on the efficacy of tulobuterol combined with an anticholinergic. In this study, we investigated the efficacy and safety of transdermal tulobuterol combined with inhaled tiotropium in COPD. METHODS: After a 2-week run-in period, 103 stable COPD patients aged >or=40 years were randomized into two groups: inhaled tiotropium (18microg, Tio group) or transdermal tulobuterol (2mg) combined with inhaled tiotropium (18microg, Tio+Tulo group) for 8 weeks. Primary endpoints were pulmonary function and severity of dyspnea. The St. George's Respiratory Questionnaire (SGRQ) score was a secondary endpoint. RESULTS: In both groups, FEV(1) and FVC as well as dyspnea improved significantly after 8 weeks. In a comparison of both groups, percentage changes in IC and morning and evening peak expiratory flow were significantly greater in the Tio+Tulo group than in the Tio group. In addition, significant improvement in SGRQ score was observed in the Tio+Tulo group only. The risk of adverse events related to the study drugs was not increased. CONCLUSION: In COPD patients, additional administration of transdermal tulobuterol to inhaled tiotropium produced significant benefits in dyspnea and SGRQ score as well as pulmonary function. These benefits may be due to a reduction in pulmonary hyperinflation resulting from improvement of peripheral airflow obstruction through tulobuterol via the systemic circulation. PMID- 19875278 TI - Rhizosphere chemical dialogues: plant-microbe interactions. AB - Every organism on earth relies on associations with its neighbors to sustain life. For example, plants form associations with neighboring plants, microflora, and microfauna, while humans maintain symbiotic associations with intestinal microbial flora, which is indispensable for nutrient assimilation and development of the innate immune system. Most of these associations are facilitated by chemical cues exchanged between the host and the symbionts. In the rhizosphere, which includes plant roots and the surrounding area of soil influenced by the roots, plants exude chemicals to effectively communicate with their neighboring soil organisms. Here we review the current literature pertaining to the chemical communication that exists between plants and microorganisms and the biological processes they sustain. PMID- 19875279 TI - Production of aromatic compounds in bacteria. AB - The aromatic class of chemicals includes a large number of industrially important products. In bacteria and plants, the shikimate pathway and related biosynthetic pathways are a source of aromatic compounds having commercial value. Bacterial strains for the production of aromatic compounds from simple carbon sources as raw material have been generated by applying metabolic engineering and random/combinatorial strategies that modify central metabolism, aromatic biosynthetic pathways, transport, and regulatory functions. These strategies are complemented with heterologous gene expression and protein engineering. Engineered Escherichia coli and Pseudomonas putida strains are enabling the development of sustainable processes for the manufacture of 2-phenylethanol, p hydroxycinnamic acid, p-hydroxystyrene, p-hydroxybenzoate, anthranilate, and cyclohexadiene-transdiols, among other useful chemicals. PMID- 19875280 TI - Molecular genetics of tooth development. AB - Organogenesis depends upon a well-ordered series of inductive events involving coordination of molecular pathways that regulate the generation and patterning of specific cell types. Key questions in organogenesis involve the identification of the molecular mechanisms by which proteins interact to organize distinct pattern formation and cell fate determination. Tooth development is an excellent context for investigating this complex problem because of the wealth of information emerging from studies of model organisms and human mutations. Since there are no obvious sources of stem cells in adult human teeth, any attempt to create teeth de novo will probably require the reprogramming of other cell types. Thus, the fundamental understanding of the control mechanisms responsible for normal tooth patterning in the embryo will help us understand cell fate specificity and may provide valuable information towards tooth organ regeneration. PMID- 19875281 TI - Synthesis and biological evaluation of piperazinyl carbamates and ureas as fatty acid amide hydrolase (FAAH) and transient receptor potential (TRP) channel dual ligands. AB - The evaluation of a series of piperazinyl carbamates and ureas, designed on the basis of previously reported TRPV1 antagonists and FAAH inhibitors, led to the identification of some 'dual-action' compounds targeting both FAAH and TRPV1 or TRPA1 receptors. PMID- 19875282 TI - Isoquinoline-based analogs of the cancer drug clinical candidate tipifarnib as anti-Trypanosoma cruzi agents. AB - We developed a synthetic route to prepare isoquinoline analogs of the cancer drug clinical candidate tipifarnib. We show that these compounds kill Trypanosoma cruzi amastigotes grown in mammalian host cells at concentrations in the low nanomolar range. These isoquinolines represent new leads for the development of drugs to treat Chagas disease. PMID- 19875283 TI - Novel pyrazolopyrimidines as highly potent B-Raf inhibitors. AB - A novel series of pyrazolo[1,5-a]pyrimidines bearing a 3-hydroxyphenyl group at C(3) and substituted tropanes at C(7) have been identified as potent B-Raf inhibitors. Exploration of alternative functional groups as a replacement for the C(3) phenol demonstrated indazole to be an effective isostere. Several compounds possessing substituted indazole residues, such as 4e, 4p, and 4r, potently inhibited cell proliferation at submicromolar concentrations in the A375 and WM266 cell lines, and the latter two compounds also exhibited good therapeutic indices in cells. PMID- 19875284 TI - Discovery and optimization of antibacterial AccC inhibitors. AB - The biotin carboxylase (AccC) is part of the multi-component bacterial acetyl coenzyme-A carboxylase (ACCase) and is essential for pathogen survival. We describe herein the affinity optimization of an initial hit to give 2-(2 chlorobenzylamino)-1-(cyclohexylmethyl)-1H-benzo[d]imidazole-5-carboxamide (1), which was identified using our proprietary Automated Ligand Identification System (ALIS).(1) The X-ray co-crystal structure of 1 was solved and revealed several key interactions and opportunities for further optimization in the ATP site of AccC. Structure Based Drug Design (SBDD) and parallel synthetic approaches resulted in a novel series of AccC inhibitors, exemplified by (R)-2-(2 chlorobenzylamino)-1-(2,3-dihydro-1H-inden-1-yl)-1H-imidazo[4,5-b]pyridine-5 carboxamide (40). This compound is a potent and selective inhibitor of bacterial AccC with an IC(50) of 20 nM and a MIC of 0.8 microg/mL against a sensitized strain of Escherichia coli (HS294 E. coli). PMID- 19875285 TI - Four new cytotoxic oligosaccharidic derivatives of 12-oleanene from Lysimachia heterogenea Klatt. AB - Cytotoxicity-guided phytochemical analysis on the extract of Lysimachia heterogenea Klatt led to the isolation of 3beta,16beta-12-oleanene-3,16,23,28 tetrol (1) and its four new oligosaccharidic derivatives heterogenosides A, B, C, and D (2-5). Their structural elucidation was mainly based on NMR and mass spectral data. The time course experimental results indicated that unlike the likely lysis activity of heterogenosides B-D, heterogenoside A showed a significantly time-dependent cytotoxicity. PMID- 19875286 TI - Use of 5-hydroxy-4H-benzo[1,4]oxazin-3-ones as beta2-adrenoceptor agonists. AB - Novel beta(2)-agonists with a 5-hydroxy-4H-benzo[1,4]oxazin-3-one moiety as head group are described. Systematic chemical variations at the phenethylamine residue of these compounds lead to the discovery of compound 6m as potent, full agonist of the beta(2)-adrenoceptor with a high beta(1)/beta(2)-selectivity. Molecular modeling revealed an interaction between the carboxylic acid group of 6m and a lysine residue (K305) of the beta(2)-receptor as putative explanation for the high observed selectivity. Further, compound 6m displayed in a guinea pig in vivo model a complete reversal of acetylcholine induced bronchoconstriction which lasted over the complete study time of 5h. PMID- 19875287 TI - Synthesis and SAR of novel, non-MPEP chemotype mGluR5 NAMs identified by functional HTS. AB - This Letter describes the discovery and SAR of three novel series of mGluR5 non competitive antagonists/negative allosteric modulators (NAMs) not based on manipulation of an MPEP/MTEP chemotype identified by a functional HTS approach. This work demonstrates fundamentally new mGluR5 NAM chemotypes with submicromolar potencies, and further examples of a mode of pharmacology 'switch' to provide PAMs with a non-MPEP scaffold. PMID- 19875288 TI - Coinheritance of Noonan syndrome and Becker muscular dystrophy. AB - We describe for the first time a case of a 9-year old boy with co-existence of dystrophinopathy and Noonan syndrome (NS). Although the patient has a severe muscular clinical phenotype, consistent with Duchenne muscular dystrophy (DMD), the diagnosis of Becker muscular dystrophy (BMD) was proposed based on family history (brother with BMD) and confirmed by muscle immunohistochemistry, and molecular study shown an in-frame DMD gene mutation. The patient also fulfilled the clinical criteria of NS and he harbors a hotspot mutation on PTPN11 gene. This genetic combination may be an explanation for the variability of clinical expression in the family. PMID- 19875289 TI - Reproducibility of energy cost of locomotion in ambulatory children with spina bifida. AB - OBJECTIVES: Many ambulatory children with Spina Bifida (SB) experience functional decline in ambulation despite stable or even improving motor exams. Improving or maintaining low energy cost of locomotion during childhood and throughout the teenage years, could be an important goal for children and adolescents with SB. Purpose of this study was to determine reproducibility of energy expenditure measures during gait in ambulatory children with SB. DESIGN: Reproducibility study. SETTING: Child Development and Exercise Center of the University Children's Hospital in Utrecht, the Netherlands. PARTICIPANTS: Fourteen ambulatory children (6 boys/8 girls) with SB. Mean age was 10.8 years (+ or - 3.4). INTERVENTIONS: Net and gross energy expenditure measures during locomotion were determined during a six-minute walking test. These measures consisted of energy consumption (ECS), expressed in J/kg/min, and energy cost (EC), expressed in J/kg/m. For reliability, the intra-class coefficient (ICC) was determined. For agreement, the smallest detectable difference (SDD) was calculated. RESULTS: ICCs vary from 0.86 to 0.96 for both EC and ECS. The SDD ranges from 18-24% for gross measures, up to over 30% for net values. CONCLUSION: Reproducibility of energy expenditure during ambulation in children with SB should be considered carefully when using these measures in the evaluation of gait. High reliability of energy expenditure measurements makes these measurements appropriate to use as discriminative tools in children with SB, while agreement of only gross EC seems acceptable to use as a evaluative tool in children with SB. Overall, measures of reliability and agreement seem higher in young children when compared to adolescents. Further research is recommended to determine clinically relevant changes in energy expenditure in children with SB. PMID- 19875290 TI - Patients with type II diabetes mellitus display reduced toe-obstacle clearance with altered gait patterns during obstacle-crossing. AB - Patients with type II diabetes mellitus (DM) have been reported to be at high risk of falls that may be further increased by the effects of challenging activities such as obstacle-crossing. The purpose of this study was to compare the end-point trajectory and joint kinematic and kinetic patterns of the lower extremities between healthy subjects and individuals with DM during obstacle crossing with the leading limb. Fourteen patients with type II DM, with no to minimal peripheral neuropathy (PN), and 14 healthy controls walked and crossed obstacles of three different heights (10%, 20% and 30% of leg length) while kinematic and kinetic data were measured using a motion analysis system and two forceplates. Compared to normal, the DM group had similar walking speeds and horizontal footobstacle distances but significantly reduced leading toe-obstacle clearances, suggesting an increased risk of tripping over the obstacle. When the swing toe was above the obstacle, the DM group showed greater pelvic anterior tilt, stance ankle dorsiflexion, and smaller swing hip abduction, with reduced hip abductor moments but greater knee flexor and ankle plantarflexor and adductor moments. It is suggested that patients with type II DM, with no or minimal PN, should also be targeted for prevention of falls. Possible therapeutic interventions to decrease falls for those with DM may include strengthening of the knee flexors and ankle plantarflexor muscles, together with proprioception and balance training. PMID- 19875291 TI - Unrecognized ligamentous instability due to high-energy, low-velocity mechanism of injury. AB - We report a unique mechanism of injury and illustrate the difficulties of diagnosing purely ligamentous injuries to the cervical spine. To our knowledge, there have been no previous reports of this type of high-energy, low-velocity mechanism of injury. The pattern of injury is also unusual, consisting of anterolisthesis of L4 on L5 with bilateral perched facet joints, atlantoaxial instability and bilateral lower limb fractures. We present a 49-year-old man who experienced a high-energy, low-velocity crush injury that led to extreme hyperflexion of his spine. Standard trauma protocols were carried out, yet atlantoaxial instability was not diagnosed until 3 days post-operatively, when the patient went into respiratory failure due to high spinal cord compression. We fused the C1/2 vertebral bodies using Harm's technique; the patient exhibited no long-term spinal cord dysfunction. Although uncommon, if left undiagnosed or not considered, purely ligamentous injuries to the cervical spine can result in catastrophic complications. Such injuries are an important subgroup to be considered at the time of initial assessment. Furthermore, when managing the multi-trauma patient, clinicians must remember not to overlook the atlantoaxial joint, as high-energy, low-velocity injury to the cervical spine may lead to silent, life-threatening instability that may not be apparent on routine imaging. PMID- 19875292 TI - Protective effects of tadalafil on experimental spinal cord injury in rats. AB - Tadalafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5). Nitric oxide (NO) functions as a retrograde neurotransmitter in the spinal cord, and postsynaptic structures respond to NO by producing cGMP. The concentrations of cGMP in the spinal cord are controlled by the actions of PDE. The aim of the study was to evaluate and compare the effects of the use of both methylprednisolone and tadalafil on serum and tissue concentrations of NO, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and tissue glutathione peroxidase (GSH-Px) activity in rats with spinal cord injury (SCI). SCI was induced in Wistar albino rats by dropping a 10 g rod from a 5.0 cm height at T8-10. The 28 rats were randomly divided into four equal groups: tadalafil, methylprednisolone, non-treatment and sham groups. Rats were neurologically tested at 24 hours after trauma. At the end of the experiment, blood samples were collected and spinal cord tissue samples were harvested for biochemical evaluation. The tissue level of NO was increased in the tadalafil group compared with the non-treatment and methylprednisolone groups (p<0.05). The tissue levels of SOD and GSH-Px did not differ between the groups. Serum levels of NO were higher in the tadalafil group than in the non treatment group (p<0.05). The increase in serum SOD levels was greater in the tadalafil group than the methylprednisolone group. Serum MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non treatment group (p>0.05). Tissue MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non-treatment group and sham groups (p>0.05). Although there was no difference in neurological outcome scores between the tadalafil, methylprednisolone and non-treatment groups (p>0.05), the animals in the tadalafil and methylprednisolone groups tended to have better scores than the non-treatment group. Thus, tadalafil appears to be beneficial in reducing the effects of injury to the spinal cord by increasing tissue levels of NO and serum activity of SOD. PMID- 19875293 TI - TOR complex 2: a signaling pathway of its own. AB - Research on TOR has grown exponentially during the last decade, generating a complex model of the TOR signaling network. Rapamycin treatment provides a simple and straightforward method to inhibit the TOR signaling pathway and to study the influence of TOR on multiple cellular processes. The discovery of two distinct TOR complexes, TORC1 and TORC2, showed that studies using rapamycin targeted only one TOR signaling branch. TORC1 is directly inhibited by rapamycin, whereas TORC2 is not. There is no known TORC2-specific inhibitor, so genetic manipulation is required to study its biological function(s). Many studies in genetically tractable model organisms have expanded our understanding of TORC2 signaling. Here we focus on the TORC2 signaling pathway as revealed by these (mostly recent) studies. PMID- 19875295 TI - Conversion of lateral unicompartmental arthroplasty to anterior cruciate retaining tricompartmental knee arthroplasty. AB - This case report presents the conversion of a lateral unicompartmental arthroplasty (UKA) to an anterior cruciate retaining tricompartmental knee arthroplasty. The patient presented with disease progression to the medial and patellofemoral compartments of the knee, in addition to significant varus deformity. During revision surgery, the previously implanted UKA device was found to be well fixed and in good condition. The conventional treatment option would be conversion to total knee arthroplasty (TKA). However, in this case conversion to a tricompartmental, ligament sparing arthroplasty via implantation of a bicompartmental knee arthroplasty (BKA) device was found to be feasible. In UKA revision cases where the device is functional, the current surgical approach may be an appropriate alternative to conventional TKA. PMID- 19875294 TI - Assembly of checkpoint and repair machineries at DNA damage sites. AB - The remarkably coordinated nature of the DNA damage response pathway relies on numerous mechanisms that facilitate the assembly of checkpoint and repair factors at DNA breaks. Post-translational modifications on and around chromatin have critical roles in allowing the timely and sequential assembly of DNA damage responsive elements at the vicinity of DNA breaks. Notably, recent advances in forward genetics and proteomics-based approaches have enabled the identification of novel components within the DNA damage response pathway, providing a more comprehensive picture of the molecular network that assists in the detection and propagation of DNA damage signals. PMID- 19875296 TI - Distal femoral resection at knee replacement - the effect of varying entry point and rotation on prosthesis position. AB - Malalignment may contribute to early prosthesis failure through point loading and premature polyethylene wear. Femoral resection requires for distal planar resection contingent upon correct rotation and coronal alignment. Using a standard model, we have examined the influence of differing femoral entry points and rotations upon final femoral component positioning. A graphical method and navigation system independently quantified the individual and combined impact of these variables, in 3 planes. Nine permutations were assessed with reference to neutral rotation and a central entry point. The graphical results were corroborated by the navigation analyses. We found that external rotation and a superolateral entry point introduced the greatest error in final component positioning. We have identified a safe envelope for femoral rod positioning and recommend that the rotational alignment is determined before distal bone resection. PMID- 19875297 TI - Aseptic versus septic revision total knee arthroplasty: patient satisfaction, outcome and quality of life improvement. AB - We prospectively compared the clinical outcomes and patient satisfaction rates of aseptic (n=30) versus septic revision TKA (n=15) at a mean follow-up of 40 months. We hypothesized that the clinical results of septic revision TKA would be inferior to aseptic revision TKA. The indication for revision in aseptic group was stiffness in 11 patients, aseptic loosening in 13, patellar loosening or maltracking in 6 patients. Patients operated for infection had better post operative Knee Society Scores (KSS), Function Scores and SF-36 Mental Scores than aseptic group but there were no significant differences in the satisfaction rates. Patients operated for infection had more improvement in their KSS (p=0.004) and Function Scores (p=0.02) than patients revised for stiffness. Moreover, patients operated on for patellar problems had higher satisfaction rates than patients revised for stiffness (p=0.01) or aseptic loosening (p=0.01). Thus, patients undergoing septic revision TKA had better outcomes compared to those with aseptic revision TKA. However, in the aseptic group, revision TKA for stiffness was associated with the poorest outcomes. The indication for aseptic revision is an important variable when discussing treatment and outcome with patients. PMID- 19875299 TI - Synthesis and biological evaluation of 3',4',5'-trimethoxychalcone analogues as inhibitors of nitric oxide production and tumor cell proliferation. AB - A series of 23 3',4',5'-trimethoxychalcone analogues was synthesized and their inhibitory effects on nitric oxide (NO) production in LPS/IFN-gamma-treated macrophages, and tumor cell proliferation has been investigated. 4-Hydroxy 3,3',4',5'-tetramethoxychalcone (7), 3,4-dihydroxy-3',4',5'-trimethoxychalcone (11), 3-hydroxy-3',4,4',5'-tetramethoxychalcone (14), and 3,3',4',5' tetramethoxychalcone (15) were the most potent growth inhibitory agents on NO production, with an IC(50) value of 0.3, 1.5, 1.3 and 0.3 microM, respectively. The tumor cells proliferation assay results revealed that several compounds exhibited potent inhibition activity against different cancer cell lines. The chalcone 15 was the most potent anti-proliferative compound in the series with IC(50) values of 1.8 and 2.2 microM toward liver cancer Hep G2 and colon cancer Colon 205 cell lines, respectively. 2,3,3',4',5'-Pentamethoxychalcone (1), 3,3',4,4',5,5'-hexamethoxychalcone (3), 2,3',4,4',5,5'-hexamethoxychalcone (5), 2 hydroxy-3,3',4',5'-tetramethoxychalcone (10), 11 and 14 showed significant anti proliferation actions in Hep G2 and Colon 205 cells with an IC(50) values ranging between 10 and 20 microM. Among the tested agents, compound 7 showed selective NO production inhibition (IC(50)=0.3 microM), while has no effect on tumor cell proliferation (IC(50) >100 microM). 3,3',4,4',5'-Pentamethoxychalcone (2) showed selective anti-proliferation effect in Hep G2 cells, in addition to its potent NO inhibition, however has no such response in Colon 205 cells. In contrast, 3 formyl-3',4',5'-trimethoxychalcone (22) showed moderate growth inhibition in Colon 205 cells, while has no such effect on NO production and Hep G2 cells proliferation. These results provide insight into the correlation between some structural properties of 3',4',5'-trimethoxychalcones and their in vitro anti inflammatory and anti-cancer differentiation activity. PMID- 19875298 TI - The spirocyclopropyl moiety as a methyl surrogate in the structure of l fucosidase and l-rhamnosidase inhibitors. AB - Nitrogen-in-the-ring analogues of l-fucose and l-rhamnose were prepared, which feature a spirocyclopropyl moiety in place of the methyl group of the natural sugar. The synthetic route involved a titanium-mediated aminocyclopropanation of a glycononitrile as the key step. Four new spirocyclopropyl iminosugar analogues were generated, which displayed some activity towards l-fucosidase and l rhamnosidase. PMID- 19875300 TI - Cytotoxicity mechanisms of pyrazino[1,2-b]isoquinoline-4-ones and SAR studies. AB - The cytotoxicity showed by 1b, an interesting representant of the title compounds, for HT-29 human colon cancer cells (CI(50) value of 1.95 x 10(-7)M) has been related to the induced cell death at the G2 phase and not to DNA damage. This compound promotes the degradation of components of the G2/M checkpoint machinery, in particular cdc2, Cyclin B1 and Wee1, which represents a novel mechanism of cytotoxicity. Degradation of Wee1 seems to be mediated by proteasome activity but degradation of cdc2 has to occur through a different mechanism. The activity of 1b on G2 cell cycle components suggests that tumor cells that are arrested in G2/M by anticancer drugs like cisplatin could be targeted by compound 1b, increasing the apoptosis induction, and that their optimized analogs might be useful in the treatment of colon cancer through combination therapies with cisplatin or other anticancer drugs that affect the cytoskeleton integrity such as taxol and taxotere. SAR studies with compounds obtained by manipulation of the N(2) and C(4)-functional groups and the C(6)-chain of compound 1b have confirmed the importance of these structural features in the in vitro antitumor activity. Fused oxazolidine derivatives as compound 5 were inactive, and the lack of activity found in the replacement of the C(4)-lactam by a cyanoamine function, as in compounds 8-10, could be explained considering that their all-syn relative configuration makes them too stable to generate alkylating iminium species. PMID- 19875301 TI - Mirfentanil and A-4334: Tritiation at high specific activity. AB - Methods are presented to synthesize and characterize [(3)H] mirfentanil and [(3)H] A-4334. PMID- 19875302 TI - Changes in cucumber hypocotyl cell wall dynamics caused by Azospirillum brasilense inoculation. AB - We previously reported that Azospirillum brasilense induced a more elastic cell wall and a higher apoplastic water fraction in both wheat coleoptile and flag leaf. These biophysical characteristics could permit increased growth. Knowledge of the biochemical effects the bacteria could elicit in plant cell walls and how these responses change plant physiology is still scarce. The objective of this work was to analyze whether A. brasilense Sp245 inoculation affected elongation and extensibility of growing cucumber (Cucumis sativus) hypocotyls and ionically bound cell wall peroxidase activities. Hypocotyl tip and basal segments were excised from A. brasilense Sp245-inoculated cucumber seedlings growing in darkness under hydroponic conditions. Elongation, cell wall extensibility, cell wall peroxidase activities against ferulic acid and guaiacol and NADH oxidase activities were analyzed. Azospirillum-inoculated cucumber seedlings grew bigger than non-inoculated ones. Dynamic cell wall differences were detected between inoculated and non-inoculated hypocotyls. They included greater acid-induced cell wall extension and in vivo elongation when incubated in distilled water. Although there was no difference between treatments in either region of the hypocotyl NADH oxidase and ferulic acid peroxidase activities were lower in both regions in inoculated seedlings. These lesser activities could be delaying the stiffening of cell wall in inoculated seedlings. These results showed that the cell wall is a target for A. brasilense growth promotion. PMID- 19875303 TI - WNT signaling in ovarian follicle biology and tumorigenesis. AB - The WNTS are an expansive family of glycoprotein signaling molecules known mostly for the roles they play in embryonic development. WNT signaling first caught the attention of ovarian biologists when it was reported that the inactivation of Wnt4 in mice results in partial female-to-male sex reversal and oocyte depletion. More recently, studies using loss- and gain-of-function transgenic mouse models demonstrated the requirement for Wnt4, Fzd4 and Ctnnb1, components of the WNT pathway, for normal folliculogenesis, luteogenesis and steroidogenesis, and showed that dysregulated WNT signaling can cause granulosa cell tumor development. This review covers our current knowledge of WNT signaling in ovarian follicles, highlighting both the great promise and the many unresolved questions of this emerging field of research. PMID- 19875304 TI - Guidelines on stability evaluation of vaccines. PMID- 19875305 TI - Endovascular embolization of pulmonary sequestration in an adult. PMID- 19875306 TI - Levosimendan attenuates reperfusion injury in an isolated perfused rat heart model. AB - OBJECTIVES: The aim of this study was to investigate the effect of levosimendan on apoptosis and infarct size when administered before ischemia in an isolated rat heart model. DESIGN: An in vitro experimental study. SETTING: Animal laboratory. PARTICIPANTS: Isolated perfused rat heart preparation (n = 22). INTERVENTIONS: Perfusion with Krebs-Henseleit solution was performed for 30 minutes and then 0.1 micromol/L of levosimendan was added to the perfusion fluid for 10 minutes before global ischemia; the control hearts received no levosimendan. Hearts underwent global ischemia for 30 minutes and then were reperfused for 30 minutes before specimens were obtained for testing. MEASUREMENTS AND MAIN RESULTS: Infarct sizes were measured at the end of the reperfusion period and expressed as a percentage of the area at risk. Myocardial apoptosis was detected by using the terminal deoxynucleotidyl transferase mediated dUTP nick end-labelling (TUNEL) method. Bcl-2 expression was determined to detect antiapoptotic activity. Infarct size was significantly less in the levosimendan group (26% +/- 3% v 40% +/- 4%, respectively; p = 0.009). Levosimendan significantly reduced the proportion of TUNEL-positive cardiomyocytes (3 +/- 1 v 20 +/- 4, respectively; p < 0.001) and increased Bcl-2 expression compared with control hearts (44% +/- 3% v 31% +/- 3%, respectively; p = 0.01). Recovery of left ventricular-developed pressure 30 minutes after reperfusion in ischemic hearts pretreated with levosimendan was significantly better than that of placebo-treated hearts (53% +/- 3% v 38% +/- 3% of baseline, respectively; p = 0.004). CONCLUSIONS: Levosimendan has a cardioprotective effect when administered before ischemia in ischemia-reperfusion injury. This effect may be useful in elective cardiac surgery for protecting myocytes from ischemia reperfusion-induced apoptosis. PMID- 19875307 TI - Extracorporeal membrane oxygenation for treating severe cardiac and respiratory failure in adults: part 2-technical considerations. PMID- 19875308 TI - The Parker Flex-Tip tube is useful in a bougie-assisted endotracheal tube exchange after lung lavage. PMID- 19875309 TI - Prophylactic vasopressin in patients receiving the angiotensin-converting enzyme inhibitor ramipril undergoing coronary artery bypass graft surgery. AB - OBJECTIVE: The purpose of this study was to compare the effects of continuation versus discontinuation of the angiotensin-converting enzyme (ACE) inhibitor ramipril and assess the efficacy of prophylactic vasopressin infusion on hemodynamic stability and vasoactive drug requirements in patients undergoing coronary artery bypass graft (CABG) surgery. DESIGN: A prospective, randomized, double-blinded, single-center clinical study. SETTING: Tertiary care hospital. PARTICIPANTS: Forty-seven patients on the ACE inhibitor ramipril for 6 weeks before undergoing elective primary CABG surgery on cardiopulmonary bypass (CPB). INTERVENTIONS: Patients were randomly divided into 3 groups: group A (n = 16), patients discontinued ramipril 24 hours before surgery; group B (n = 16), patients continued ramipril until the morning of surgery; and group C (n = 15), patients continued ramipril until the morning of surgery and received vasopressin infusion (0.03 U/min) from the onset of rewarming until the hemodynamics were stable without vasopressor agents. The anesthetic technique and conduct of CPB were standardized for all the groups. Hemodynamic parameters and vasoactive drug requirements were recorded for 3 days postoperatively. MEASUREMENTS AND MAIN RESULTS: Patients in group A maintained stable mean arterial pressure (MAP) and systemic vascular resistance (SVR). In group B, MAP and SVR decreased after the induction of anesthesia and remained so throughout surgery (p < 0.05). In group C, MAP and SVR decreased upon the induction of anesthesia (p < 0.05) but normalized after CPB. CONCLUSIONS: Preoperative ACE inhibitor continuation predisposed to hypotension upon the induction of anesthesia and in the post-CPB period. Prophylactic low-dose vasopressin infusion prevented post-CPB hypotension. Low-dose vasopressin can be considered as potential therapy in these patients. PMID- 19875310 TI - Alteration in systemic vascular resistance and cardiac output during acute cellular rejection and recovery in heart transplant recipients. AB - Coronary vascular reserve is impaired during acute cellular rejection of the orthotopically transplanted heart, but changes in the peripheral vasculature during rejection have not been well described. To investigate whether peripheral vascular compensatory mechanisms are preserved after orthotopic heart transplantation (OHT), we longitudinally observed systemic vascular resistance (SVR) and cardiac output (CO) during acute cellular rejection. CO decreased during high-grade acute cellular rejection, and maintenance of mean arterial pressure was achieved by increases in SVR, and these changes did not return to baseline until several months after histologic resolution of rejection. PMID- 19875311 TI - Enhancing memory for lists by grouped presentation and rehearsal: a pilot study in healthy subjects with unexpected results. AB - List learning is probably the most established paradigm for the psychometric evaluation of episodic memory deficits in different neuropsychiatric conditions including epilepsy. Strategies which are capable of increasing the test performance might be promising candidates for a therapeutic improvement of daily memory performance. Based on the classical 'temporal grouping effect' we wanted to evaluate the memory-enhancing potential of disentangling perceiving, rehearsing and encoding by temporally grouped presentation and group-wise reproduction during acquisition. According to the ethical principle of subsidiary the study was performed in healthy adolescents (N=126) before setting-up a patient study. Subjects had to learn a list of 12 semantically unrelated nouns and a list of 12 figures during two acquisition trials under one of four experimental conditions defined by the size of presented item groups (GS): GS=1 (single items, i.e., 12 x 1 item), GS=3 (4 x 3 items), GS=6 (2 x 6 items), and GS=12 (standard presentation mode, i.e., 1 x 12 items). Repeated measures MANOVA confirmed a positive effect of smaller GS on acquisition performance but the grouping condition obtained no effect on immediate and delayed free recall or on yes/no recognition. For verbal retention, GS=12 even showed a tendency toward an advantage as compared to GS=3. Although appearing reasonable and promising, facilitating acquisition during list learning by temporal grouping and grouped overt rehearsal turned out to be ineffective with regard to long-term memory encoding and retrieval. A strategy however which fails in healthy subjects is unlikely to obtain a therapeutic potential in patients with memory deficits. PMID- 19875312 TI - Variable-resolution cone-beam computerized tomography with enhancement filtration compared with intraoral photostimulable phosphor radiography in detection of transverse root fractures in an in vitro model. AB - OBJECTIVES: The aim of this study was to compare the diagnostic accuracy of an intraoral photostimulable storage phosphor (PSP) plate system and cone-beam computerized tomography scanning (CBCT) for detection of experimentally induced transverse root fractures and to evaluate differences between original images and images enhanced with high-pass filters. STUDY DESIGN: Sixty-nine extracted human teeth, 34 with root fractures and 35 without, were examined under standardized conditions using an intraoral PSP system (Digora Optime; Soredex). The images were saved in original 8-bit format and in a version sharpened with a high-pass filter. The teeth were examined with CBCT (i-Cat; Imaging Sciences) in 2 resolutions: 0.125 mm and 0.25 mm voxel size. Original images were saved together with images enhanced with 2 high-pass filters, sharpen and angio-sharpen. Six observers scored the presence of a root fracture in all modalities in random order. Sensitivity, specificity, and accuracy [(true positives + true negatives)/all scores] were calculated for each modality and each observer. Differences were estimated by analyzing the binary data, assuming additive effects of observer and modality in a generalized linear model. RESULTS: High resolution original CBCT images had higher sensitivity (P < .05) than lower resolution images and PSP images (0.125 mm resolution 87%, 0.25 mm resolution 72%, and PSP 74%). Angio-sharpen-filtered images for both CBCT resolutions had higher sensitivities (P < .02) than the original images (0.125 mm resolution: 95% vs. 87%; 0.25 mm resolution: 81% vs. 72%). There was no significant difference between the lower-resolution CBCT and PSP images. Only small differences in specificity were seen between modalities, and accuracy was higher for high resolution CBCT than for the other modalities (P < .03). CONCLUSIONS: High resolution i-Cat CBCT images resulted in an increase in sensitivity without jeopardizing specificity for detection of transverse root fractures compared with lower-resolution CBCT images, which were not more accurate than periapical PSP images. The angio-sharpen high-pass filter improved sensitivity in the high resolution CBCT images in this in vitro model. PMID- 19875313 TI - Dentigerous cyst associated with an ectopic tooth in the maxillary sinus: a report of 3 cases and review of the literature. AB - Dentigerous cysts are benign odontogenic cysts that are associated with the crowns of permanent teeth. Dentigerous cysts surrounding impacted teeth often displace teeth into ectopic positions. In the maxilla, these teeth are often displaced into the maxillary sinus. We report 3 cases of dentigerous cysts associated with an ectopic tooth in the maxillary sinus and review the literature reports of this condition over the past 29 years. PMID- 19875314 TI - The quality of single cone and laterally compacted gutta-percha fillings in small and curved root canals as evidenced by bidirectional radiographs and fluid transport measurements. AB - OBJECTIVE: The aim of this study was to examine the quality of root fillings in small and curved root canals using bidirectional radiographs and fluid transport (FT) measurements. STUDY DESIGN: Root canals in eighty 38 degrees -curved mesial roots of mandibular molars were prepared using a balanced force technique. Samples were divided into 4 groups of 20 each and obturated by either the cold lateral compaction (LC) or the single cone (SC) technique, using either epoxy resin-based or zinc oxide-eugenol sealers. Bidirectional (buccolingual and mesiodistal) radiographs were acquired from each root. The voids along the root filling were assessed. The FT along the root filling was measured using an FT monitoring device. The differences between the groups regarding FT and the bidirectional radiographic score were analyzed by means of a Kruskal-Wallis test. The correlation between the FT values and the radiographic scores were analyzed using a Spearman test. RESULTS: Three groups of LC or SC fillings containing epoxy resin-based sealers exhibited similar radiographic scores and FT values (P > .05). The group of SC fillings that contained zinc oxide-eugenol sealer had worse radiographic scores than the other groups (P = .047). The bidirectional radiographic scores and the FT values for the 80 filled roots were strongly correlated (r(2) = 0.519; P = .00001). CONCLUSION: Root fillings of similar quality were confirmed in small and curved root canals filled using either a single cone or laterally compacted gutta-percha and epoxy resin-based sealers. PMID- 19875315 TI - Occurrence of no-function of two electronic apex locators: an in vivo study. AB - OBJECTIVES: This in vivo study was aimed at quantifying the electronic no function rate of 2 electronic apex locators, ApexPointer and Novapex, and evaluating whether their operation is affected by the type of applied treatment, patient's age, and the type of tooth. STUDY DESIGN: A total of 209 root canals were included in this study. For each canal, the electronic length was determined and verified by radiography. Whenever the electronic device failed to provide a value, it was recorded as an electronic no-function. Experimental data were statistically tested with chi-squared through Statview. RESULTS: For both apex locators, the no-function rate remained around 15% and did not seem to be affected by the age of patients. A statistically significant relationship was found between no-function rate and retreatment (P < .05). The type of tooth had no influence on the no-function rate. CONCLUSIONS: Under the conditions of this assessment in vivo, the 2 apex locators proved to give no value in about 15% of the cases. Further investigations are necessary to clear up the links between no function and retreatment or age. PMID- 19875316 TI - Impact of smear layer on sealing property of root canal obturation using 3 different techniques and sealers. Part I. AB - OBJECTIVE: The objective of this study was to determine the influence of smear layer removal on through-and-through fluid movement along root canal fillings obturated using 3 different root canal sealers, namely AH26, Pulp Canal Sealer, and Gutta-Flow, and 3 different obturation techniques. STUDY DESIGN: The fluid transport model was used for detection of through-and-through fluid movement. Root canals of 230 human extracted teeth were mechanically instrumented using the step-back technique. The canals where the smear layer was not removed were irrigated with NaOCl 2.4%, whereas canals where the smear layer was removed were irrigated with EDTA 17% plus NaOCl 2.4%. The teeth were randomly divided into 10 experimental groups (n = 20) and 3 control groups (n = 10) and treated as follows. In group A, where no attempt was made for smear layer removal, the canals were obturated with lateral compaction of gutta-percha and AH26 as a sealer. In group B, the smear layer was removed, and canals were obturated as in group A. In group C (no attempt to remove the smear layer), the canals were obturated with System B plus Obtura II technique and AH26, whereas in group D, the smear layer was removed, and canals were obturated as in group C. The other 4 experimental groups were treated and obturated in the same way as in previous groups, respectively. The sealer that was used in those groups was the Pulp Canal Sealer. Finally, the latter 2 groups were obturated with Gutta-Flow technique. Fluid movement was measured at 24 hours and 30 days and 6 months. RESULTS: In lateral compaction groups (with and without the smear layer), no significant differences were found regarding the ability of the same materials (AH26 and Pulp Canal Sealer) to prevent the fluid movement (P > .05). In warm obturation technique, no significant difference was found between the 2 groups (with and without the smear layer) of AH26 (P > .05). On the contrary, in groups of Pulp Canal sealer, fluid transport values were significantly less when the smear layer was removed (P < .05). Finally, no significant difference was observed between the groups of Gutta-Flow (with and without the smear layer) (P > .05). CONCLUSIONS: Under these in vitro conditions, it seems that smear layer removal improves the ability of the filling materials to prevent the fluid movement, at least after the use of warm obturation techniques. On the contrary, smear layer removal does not seem to improve the same ability after the use of cold lateral compaction technique. Further laboratory and also clinical studies are needed in the future to compose a clear view concerning the improvement of sealing ability following smear layer removal. PMID- 19875317 TI - Bilateral sagittal split osteotomies and mandibular distraction osteogenesis: a randomized controlled trial comparing skeletal stability. AB - OBJECTIVE: To conduct a randomized controlled trial comparing the skeletal stability of bilateral sagittal split osteotomy (BSSO) and mandibular distraction ostoegenesis (MDO) for moderate mandibular advancement. STUDY DESIGN: Fourteen class II mandibular hypoplasia patients requiring mandibular advancement between 6 and 10 mm were randomized into 2 groups for either BSSO or MDO. Serial lateral cephalographs were taken 2 weeks, 6 weeks, 12 weeks, 6 months, and 12 months after surgery for the assessment of skeletal stability. The Student t test was used to analyze stability with statistical significance set at P < .05. RESULTS: There was no significant difference (P > .05) in horizontal and vertical skeletal relapse between the 2 groups at every postoperative time period. CONCLUSIONS: Although the MDO group reported less horizontal and vertical skeletal relapse for mandibular advancements between 6 and 10 mm at 1 year, no statistically significance was found between the groups. Other patient-related factors need to be considered when choosing one technique over the other. PMID- 19875318 TI - The closure of oroantral communications with resorbable PLGA-coated beta-TCP root analogs, hemostatic gauze, or buccal flaps: a prospective study. AB - OBJECTIVE: The aim of this study was to compare the treatment of oroantral communications (OACs) with bioresorbable root analogs made of poly(lactide-co glycolide) (PLGA)-coated beta-tricalcium phosphate (beta-TCP), hemostatic gauze or a buccal flap technique. STUDY DESIGN: In this prospective clinical study, 30 patients with oroantral communications were randomly assigned to a treatment. Clinical success, vestibular depth at the defect site, pain, and swelling were monitored. RESULTS: The OAC closure was successful in all cases. The vestibular depth stayed constant in the groups treated with the PLGA-beta-TCP composite or hemostatic gauze. In contrast, a vestibular depth reduction of 1.2 +/- 0.2 mm was observed in the buccal flap group, indicating atrophy of the alveolar ridge in these patients. Furthermore, pain and swelling were more pronounced in this group. CONCLUSION: Closures of OACs with PLGA-beta-TCP composite or hemostatic gauze are reliable minimally invasive methods that minimize atrophy of the alveolar ridge, swelling, and pain compared with a buccal flap technique. PMID- 19875319 TI - Assessment of pregnancy outcomes with uterine leiomyomas larger than 10 cm; antepartum and postpartum complications. PMID- 19875320 TI - Do illness perceptions predict pain-related disability and mood in chronic orofacial pain patients? A 6-month follow-up study. AB - In our study, we investigated the predictive value of illness beliefs as measured by the revised illness perception questionnaire (IPQ-R) in the context of other clinical predictors in patients with chronic orofacial pain over a 6-month follow up period. Consecutive patients (152) referred to the interdisciplinary orofacial pain service at the Centre for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zurich received questionnaires to assess pain and pain related disability, anxiety, depression as well as physical and mental quality of life at three time points: prior to treatment, 3 and 6 months after beginning of treatment. RESULTS: significant improvement was found over time for all outcome measures except mental quality of life. RESULTS of the regression analysis indicated that believing pain could have serious consequences on one's life (IPQ subscale consequences) is one of the most important predictors for treatment outcome. The belief in low personal control and in a chronic timeline is also shown to be predictive for outcome, though explaining a smaller proportion of variance. These results provided evidence that beliefs about pain are important predictors for treatment outcome even when controlled for pain and mood. They therefore need to be considered in the management of patients with chronic orofacial pain. Assessing patients' illness beliefs can provide essential information on these important psychological determinants of adjustment to chronic pain and may be specific targets for individualised treatment approaches. PMID- 19875321 TI - Improved synthesis of diethyl 2,6-dimethyl-4-aryl-4H-pyran-3,5-dicarboxylate under ultrasound irradiation. AB - Diethyl 2,6-dimethyl-4-aryl-4H-pyran-3,5-dicarboxylates (1) have been synthesized by the reaction of aryl aldehyde and 1,3-diketone catalyzed by ZnCl(2) under ultrasound irradiation. The effects of changes in the ultrasonic power, temperature, and reaction time are discussed. With the optimized reaction conditions, various aryl aldehydes were used to synthesize 4H-pyrans (1) under the influence of ultrasound irradiation. Compared with the conventional thermal methods, the remarkable advantages of this method are the simple experimental procedure, shorter reaction time and high yield of product. PMID- 19875322 TI - A method to estimate EMG crosstalk between two muscles based on the silent period following an H-reflex. AB - The crosstalk phenomenon consists in recording the volume-conducted electromyographic activity of muscles other than that under study. This interference may impair the correct interpretation of the results in a variety of experiments. A new protocol is presented here for crosstalk assessment between two muscles based on changes in their electrical activity following a reflex discharge in one of the muscles in response to nerve stimulation. A reflex compound muscle action potential (H-reflex) was used to induce a silent period in the muscle that causes the crosstalk, called here the remote muscle. The rationale is that if the activity recorded in the target muscle is influenced by a distant source (the remote muscle) a silent period observed in the electromyogram (EMG) of the remote muscle would coincide with a decrease in the EMG activity of the target muscle. The new crosstalk index is evaluated based on the root mean square (RMS) values of the EMGs obtained in two distinct periods (background EMG and silent period) of both the remote and the target muscles. In the present work the application focused on the estimation of the degree of crosstalk from the soleus muscle to the tibialis anterior muscle during quiet stance. However, the technique may be extended to other pairs of muscles provided a silent period may be evoked in one of them. PMID- 19875324 TI - Demographics of international contact lens prescribing. AB - Knowledge of differences in the demographics of contact lens prescribing between nations, and changes over time, can assist (a) the contact lens industry in developing and promoting various product types in different world regions, and (b) practitioners in understanding their prescribing habits in an international context. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 reveal an ageing demographic, with Japan being the most youthful. The majority of fits are to females, with statistically significant differences between nations, ranging from 62 per cent of fits in Norway to 68 per cent in Japan. The small overall decline in the proportion of new fits, and commensurate increase in refits, over the survey period may indicate a growing rate of conversion of lens wearers to more advanced lens types, such as silicone hydrogels. PMID- 19875323 TI - Examining evidence for neighbourhood variation in the duration of untreated psychosis. AB - BACKGROUND: Family involvement in help-seeking is associated with a shorter duration of untreated psychoses [DUP], but it is unknown whether neighbourhood level factors are also important. METHODS: DUP was estimated for all cases of first-episode psychoses identified over 2 years in 33 Southeast London neighbourhoods (n = 329). DUP was positively skewed and transformed to the natural logarithm scale. We fitted various hierarchical models, adopting different assumptions with regard to spatial variability of DUP, to assess whether there was evidence of neighbourhood heterogeneity in DUP, having accounted for a priori individual-level confounders. RESULTS: Neighbourhood-level variation in DUP was negligible compared to overall variability. A non hierarchical model with age, sex and ethnicity covariates, but without area-level random effects, provided the best fit to the data. DISCUSSION: Neighbourhood factors do not appear to be associated with DUP, suggesting its predictors lie at individual and family levels. Our results inform mental healthcare planning, suggesting that in one urbanised area of Southeast London, where you live does not affect duration of untreated psychosis. PMID- 19875325 TI - Adding pieces to the puzzling plant nuclear envelope. AB - The nuclear envelope (NE) and the nuclear pores are important structures that both separate and selectively connect the nucleoplasm and the cytoplasm. NE and nuclear pore research in plants have recently seen an elevated level of interest. This is based both on new findings demonstrating the importance of nucleocytoplasmic trafficking for several signal transduction events, and on increasing evidence that NE and nuclear pore components play important roles during plant cell division. Here, we review the most recent reports in the field and compare them to the more advanced knowledge about yeast and animal model systems. They deal with the refined ultrastructure of the NE and NPC, with the discovery of novel NE components, and, importantly, with novel roles and fates of NE-associated and NPC-associated proteins during plant mitosis and cytokinesis. PMID- 19875327 TI - A scaled quantum mechanical approach of vibrational analysis of o-tolunitrile based on FTIR and FT Raman spectra, ab initio, Hartree Fock and DFT methods. AB - The FTIR and FT Raman vibrational spectra of o-tolunitrile have been recorded using Perkin-Elmer 180 Spectrometer in the range 3100-100 cm(-1). A detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The optimized geometrical parameters, force constants, true rotational constants, rotational temperatures, Potential Energy Distribution (PED) and fundamental vibrational frequencies of the title compound were evaluated using Hartree Fock and Density Functional B3LYP methods with 6-31G(d) basis sets. The vibrational harmonic frequencies were scaled using scale factor which yielded a good agreement between observed and calculated frequencies. With hope of providing more and effective information on the fundamental vibrations, a normal co-ordinate analysis has been performed by assuming C(s) point group symmetry. The results of the calculations were applied to simulated Infrared and Raman spectra of the title compound which showed excellent agreement with the observed spectra. PMID- 19875326 TI - Rearrangements of the transcriptional regulatory networks of metabolic pathways in fungi. AB - Growing evidence suggests that transcriptional regulatory networks in many organisms are highly flexible. Here, we discuss the evolution of transcriptional regulatory networks governing the metabolic machinery of sequenced ascomycetes. In particular, recent work has shown that transcriptional rewiring is common in regulons controlling processes such as production of ribosome components and metabolism of carbohydrates and lipids. We note that dramatic rearrangements of the transcriptional regulatory components of metabolic functions have occurred among ascomycetes species. PMID- 19875328 TI - The structural properties of poly(aniline)--analysis via FTIR spectroscopy. AB - Aniline was polymerized under different experimental conditions like variation in time, temperature, monomer and concentration of initiators. Relative intensity of the benzenoid and quinonoid forms were estimated and correlated with poly(aniline) (PANI) structure. TGA counseled the thermal stability of poly(aniline). Through FTIR study, the structure of poly(aniline) was recognized. Comparison of polymerized aniline with two different initiators was done. PMID- 19875329 TI - Formyl- and acetylindols: vibrational spectroscopy of an expectably pharmacologically active compound family. AB - In the present paper, indole and its seven derivatives were compared, namely 3 formylindole, 1-methyl-3-formylindole, 1-ethyl-3-formylindole, 3-acetylindole, 1 methyl-3-acetylindole, 1-ethyl-3-acetylindole and 1,3-diacetylindole. The substitution of indole in position 3 with aldehydes and with alkyl groups cause only minor changes in the molecular geometry, however, substantially larger alterations are found in the charge distribution and in the vibrational force constants. The appearance of the aldehyde groups increased the degree of association as it was observable on the shape of infrared NH stretching band and its shifts. The alkyl substitution shifts the aldehyde carbonyl stretch band frequencies to somewhat higher values. The effect of the second acetyl group in position 1 is not comparable with those of the 1-alkyl groups. The latter effect is observable in the molecular geometry, however, it is more pronounced in the changes of the net charge distribution, the vibrational force constants and the infrared spectra. PMID- 19875330 TI - Raman spectroscopy for the identification of pigments and color measurement in Duges watercolors. AB - Spectroscopic and colorimetric analysis of a representative set of Duges watercolor paintings was performed. These paintings were the result of scientific studies carried out by the zoologist Alfredo Duges, who recorded the fauna of the Mexican Republic between 1853 and 1910. Micro-Raman spectroscopy, with an excitation wavelength of 830 nm, and colorimetric techniques were employed in order to understand if different colors with the same hue were reproduced using the same pigments. The color coordinates of the measured areas were obtained in the CIEL*a*b* color space. Raman analysis showed that, in some cases, to reproduce colors with the same hue the pigment employed was not the same. Pigments identified in the watercolors were vermilion, carbon-based black, lead white, gamboge and chrome yellow, Prussian and ultramarine blue. Some of these pigments have been used since ancient times, others as Prussian blue, chrome yellow and synthetic ultramarine blue arrived to the market at the beginning of the 18th and 19th centuries, respectively. Furthermore, regarding the white color, instead of left the paper unpainted, lead white was detected in the eye of a bird. The green color was obtained by mixing Prussian blue with chrome yellow. The results of this work show the suitability of using Raman spectroscopy for watercolor pigment analysis and colorimetric techniques to measure the color of small areas (246 microm x 246 microm) that was the case for the lead white pigment. PMID- 19875331 TI - Influences of urea and guanidine hydrochloride on the interaction of 6 thioguanine with bovine serum albumin. AB - The interaction of 6-thioguanine (6-TG) and bovine serum albumin (BSA) in the absence and presence of denaturant (urea and Guanidine hydrochloride) was investigated by fluorescence spectroscopic techniques. Changes of fluorescence intensity both in F(304) and in F(348) of BSA reflected increasing participation of tyrosine fluorescence in the total emission with increasing denaturant, which indicated that energy transfer from tyrosyl residues to tryptophanyl residues became less efficient in the denatured tertiary protein structure. The quenching effects of 6-TG were shown not only on the native but also on the unfolded form of BSA. The quenching constants and binding constants were calculated from the fluorescence spectra of the BSA/6-TG complex both in the absence and presence of the denaturant. The data suggested that the quenching constants and binding constants of 6-TG for BSA decreased with increasing concentration of denaturant. The spectroscopic analysis also showed antidenaturant properties of 6-TG under both denaturant conditions. PMID- 19875332 TI - Mining of clinical and biomedical text and data: editorial of the special issue. PMID- 19875333 TI - Severe gastroenteritis with secondary fever in a 10-month-old boy. PMID- 19875334 TI - Cortical neural plasticity in aged human brains. PMID- 19875335 TI - Motor excess during movement: Overflow, mirroring, and synkinesis. PMID- 19875336 TI - Cetuximab and panitumumab: are they interchangeable? PMID- 19875338 TI - Round table on the management of renal pelvic dilatation in children. PMID- 19875339 TI - IL-15 promotes regulatory T cell function and protects against diabetes development in NK-depleted NOD mice. AB - IL-15, an anti-apoptotic cytokine, has been reported to promote the survival and function of NK cells and T cells, including regulatory T cells (Tregs). Here we examined the effect of repeated injections of IL-15 on the development of diabetes in NOD mice. Injection of recombinant murine IL-15, once a day for 2 weeks, neither inhibited nor accelerated diabetes development in untreated NOD mice. However, treatment with IL-15 significantly reduced the incidence and delayed the onset of diabetes in NOD mice that were depleted of NK cells, while NK cell depletion alone had no protection against the disease development. The protective effect in IL-15-treated, NK cell-depleted NOD mice was associated with an increase in immunosuppressive activity of CD4(+)CD25(+) Tregs. IL-15 also enhanced Foxp3 expression in CD4(+)CD25(+) cells in an in vitro culture system, and such an effect of IL-15 was abrogated by IL-15-activated NK cells. Inhibition of IL-15-induced Foxp3 expression by IL-15-activated NK cells likely resulted from their IFN-gamma production, as recombinant IFN-gamma, or the culture supernatant of IL-15-activated wild-type mouse NK cells but not of IL-15 activated IFN-gamma-deficient NK cells, mediated a similar inhibition. IFN-gamma also diminished the stimulatory effect of IL-15 on Treg function in vitro. These results indicate that IL-15 has the potential to promote Treg function and protect against diabetes development in NOD mice, but such an activity can be eliminated by simultaneous activation of NK cells in IL-15-treated mice. PMID- 19875337 TI - Chemoradiotherapy for locally advanced head and neck cancer: 10-year follow-up of the UK Head and Neck (UKHAN1) trial. AB - BACKGROUND: Between 1990 and 2000, we examined the effect of timing of non platinum chemotherapy when combined with radiotherapy. We aimed to determine whether giving chemotherapy concurrently with radiotherapy or as maintenance therapy, or both, affected clinical outcome. Here we report survival and recurrence after 10 years of follow-up. METHODS: Between Jan 15, 1990, and June 20, 2000, 966 patients were recruited from 34 centres in the UK and two centres from Malta and Turkey. Patients with locally advanced head and neck cancer, and who had not previously undergone surgery, were randomly assigned to one of four groups in a 3:2:2:2 ratio, stratified by centre and chemotherapy regimen: radical radiotherapy alone (n=233); radiotherapy with two courses of chemotherapy given simultaneously on days 1 and 14 of radiotherapy (SIM alone; n=166); or 14 and 28 days after completing radiotherapy (SUB alone, n=160); or both (SIM+SUB; n=154). Chemotherapy was either methotrexate alone, or vincristine, bleomycin, methotrexate, and fluorouracil. Patients who had previously undergone radical surgery to remove their tumour were only randomised to radiotherapy alone (n=135) or SIM alone (n=118), in a 3:2 ratio. The primary endpoints were overall survival (from randomisation), and event-free survival (EFS; recurrence, new tumour, or death; whichever occurred first) among patients who were disease-free 6 months after randomisation. Analyses were by intention to treat. This trial is registered at www.Clinicaltrials.gov, number NCT00002476. FINDINGS: All 966 patients were included in the analyses. Among patients who did not undergo surgery, the median overall survival was 2.6 years (99% CI 1.9-4.2) in the radiotherapy alone group, 4.7 (2.6-7.8) years in the SIM alone group, 2.3 (1.6 3.5) years in the SUB alone group, and 2.7 (1.6-4.7) years in the SIM+SUB group (p=0.10). The corresponding median EFS were 1.0 (0.7-1.4), 2.2 (1.1-6.0), 1.0 (0.6-1.5), and 1.0 (0.6-2.0) years (p=0.005), respectively. For every 100 patients given SIM alone, there are 11 fewer EFS events (99% CI 1-21), compared with 100 given radiotherapy, 10 years after treatment. Among the patients who had previously undergone surgery, median overall survival was 5.0 (99% CI 1.8-8.0) and 4.6 (2.2-7.6) years in the radiotherapy alone and SIM alone groups (p=0.70), respectively, with corresponding median EFS of 3.7 (99% CI 1.1-5.9) and 3.0 (1.2 5.6) years (p=0.85), respectively. The percentage of patients who had a significant toxicity during treatment were: 11% (radiotherapy alone, n=25), 28% (SIM alone, n=47), 12% (SUB alone, n=19), and 36% (SIM+SUB, n=55) among patients without previous surgery; and 9% (radiotherapy alone, n=12) and 20% (SIM alone, n=24) among those who had undergone previous surgery. The most common toxicity during treatment was mucositis. The percentage of patients who had a significant toxicity at least 6 months after randomisation were: 6% (radiotherapy alone, n=13), 6% (SIM alone, n=10), 4% (SUB alone, n=7), and 6% (SIM+SUB, n=9) among patients who had no previous surgery; and 7% (radiotherapy alone, n=10) and 11% (SIM alone, n=13) among those who had undergone previous surgery. The most common toxicity 6 months after treatment was xerostomia, but this occurred in 3% or less of patients in each group. INTERPRETATION: Concurrent non-platinum chemoradiotherapy reduces recurrences, new tumours, and deaths in patients who have not undergone previous surgery, even 10 years after starting treatment. Chemotherapy given after radiotherapy (with or without concurrent chemotherapy) is ineffective. Patients who have undergone previous surgery for head and neck cancer do not benefit from non-platinum chemotherapy. FUNDING: Cancer Research UK, with support from University College London and University College London Hospital Comprehensive Biomedical Research Centre. PMID- 19875340 TI - Factors impacting all-cause mortality in prostate cancer brachytherapy patients with or without androgen deprivation therapy. AB - PURPOSE: Certain subsets of patients have an increased risk of all-cause mortality when androgen deprivation therapy (ADT) is used with definitive radiotherapy. We evaluated the relationship between pretreatment serum testosterone, age, and comorbidities on survival after prostate brachytherapy in men treated with and without ADT. METHODS AND MATERIALS: From October 2001 to September 2005, 803 patients underwent brachytherapy and 720 had a pretreatment serum testosterone. Comorbidities were prospectively recorded for each patient (body mass index>30, hypertension, diabetes, current smoker). Median followup was 5.0 years. 34.2% of the patients received ADT. Focus was on subset of men who might be expected to have more significant side effects associated with ADT. RESULTS: ADT did not significantly impact overall survival (OS) in men <65 years, >65 years, with one or no comorbidities, with more than one comorbidity, or with normal/high testosterone level. ADT use in men with low testosterone level was associated with decreased OS (83.6% vs. 93.1%, p=0.01). The adverse impact of ADT in men with low testosterone level was restricted to men with low testosterone level and more than one comorbidity (OS of 71.3% vs. 92.8%, p<0.01), with death from cardiovascular diseases accounting for almost all of the excess mortality. The subset of men with multiple comorbidities and normal/high testosterone level did not experience adverse OS with ADT. CONCLUSIONS: Low pretreatment testosterone level may be a marker for men at increased risk of premature death with ADT. The combination of low pretreatment serum testosterone level and multiple preexisting comorbidities is associated with decreased OS when ADT is incorporated into treatment. PMID- 19875341 TI - A single-institutional brachytherapy experience in the management of esophageal cancer. AB - PURPOSE: The aim of this work was to analyze the efficacy of high-dose-rate brachytherapy in the management of patients with esophageal cancer. METHODS AND MATERIALS: Between 2001 and 2008, 104 patients (88 males and 16 females) received a brachytherapy treatment as a part of a personalized multimodal approach. The median age was 72 years, and the median Karnofsky performance status was 60. Brachytherapy was used in different situations: to complete a primary treatment with radical intent in patients not suitable for surgery; to control local recurrences; or to obtain a rapid and durable palliation of dysphagia in patients with metastases or in poor general condition. In selected cases, endoscopic ultrasound images were integrated in treatment planning procedure to obtain a more accurate volume definition. Efficacy in controlling dysphagia was assessed 1 month after brachytherapy. RESULTS: Fifty-one patients received a radical treatment, and 53 patients were treated to relieve the symptoms. The median overall survival was 20.8 months. Lymph node involvement was found to be a significant prognostic factor for overall survival and dysphagia. Dysphagia was controlled in 88 patients (84.6%), and the median dysphagia-free interval was 17.5 months. Early and late adverse events were generally mild to moderate. The most severe effects were esophagotracheal fistulas, observed in 3 patients. CONCLUSIONS: Brachytherapy has an important role in the management of esophageal cancer with a low rate of complications. endoscopic ultrasound-assisted treatment planning can be useful for a better individualization of curative treatments. PMID- 19875342 TI - Live three-dimensional transesophageal echocardiographic imaging of novel multielectrode ablation catheters. PMID- 19875343 TI - Cardiac ion channels in health and disease. AB - Cardiac electrical activity depends on the coordinated propagation of excitatory stimuli through the heart and, as a consequence, the generation of action potentials in individual cardiomyocytes. Action potential formation results from the opening and closing (gating) of ion channels that are expressed within the sarcolemma of cardiomyocytes. Ion channels possess distinct genetic, molecular, pharmacologic, and gating properties and exhibit dissimilar expression levels within different cardiac regions. By gating, ion channels permit ion currents across the sarcolemma, thereby creating the different phases of the action potential (e.g., resting phase, depolarization, repolarization). The importance of ion channels in maintaining normal heart rhythm is reflected by the increased incidence of arrhythmias in inherited diseases that are linked to mutations in genes encoding ion channels or their accessory proteins and in acquired diseases that are associated with changes in ion channel expression levels or gating properties. This review discusses ion channels that contribute to action potential formation in healthy hearts and their role in inherited and acquired diseases. PMID- 19875344 TI - Prevalence of dyslipidemia in adults with cystic fibrosis. AB - BACKGROUND: A high fat calorie diet is advocated for patients with cystic fibrosis (CF) however the lipid profiles of individuals with CF, including those with CF-related diabetes (CFRD), are not well studied. METHODS: We conducted a retrospective review of adult CF patients attending St Michael's Hospital between January 2005 and December 2007. RESULTS: 334 patients (77% pancreatic insufficient (PI)) were included in the study. Mean HDL cholesterol was significantly lower in males (p<0.0001) with 44% of males having HDL cholesterol <38.7mg/dL(1mmol/L). Pancreatic sufficient patients were more likely than PI subjects to have total cholesterol >201mg/dL(5.2mmol/L) (p<0.01). 5% of subjects had triglyceride concentrations >195mg/dL(2.2mmol/L). Diabetes was diagnosed in 23% of subjects. Lipid profiles were similar between diabetics and non-diabetics. Total cholesterol and triglycerides both increased with increasing age and increasing BMI (p<0.01). CONCLUSION: Dyslipidemia occurs in CF patients however no differences in lipid profiles were seen between those with diabetes and those without. Fasting lipids should be monitored in CF patients, particularly those with PS, older age, and high BMI. As survival in CF increases, the prevalence of dyslipidemia may increase resulting in clinically important complications. PMID- 19875345 TI - [Amoebic liver abscess]. PMID- 19875346 TI - Obesity and gestational diabetes. AB - The prevalence of both obesity and gestational diabetes mellitus (GDM) is increasing worldwide. GDM affects about 7% of all pregnancies and is defined as any degree of impaired glucose tolerance during gestation. The presence of obesity has a significant impact on both maternal and fetal complications associated with GDM. These complications can be addressed, at least in part, by good glycaemic control during pregnancy. The significance and impact of obesity in women with GDM are discussed in this article, together with treatment options, the need for long-term risk modification and postpartum follow-up. PMID- 19875347 TI - The nitric acid burn trauma of the skin. AB - Nitric acid burn traumata often occur in the chemical industry. A few publications addressing this topic can be found in the medical database, and there are no reports about these traumata in children. A total of 24 patients, average 16.6 years of age, suffering from nitric acid traumata were treated. Wound with I degrees burns received open therapy with panthenol-containing creams. Wound of II degrees and higher were initially treated by irrigation with sterile isotonic saline solution and then by covering with silver-sulphadiazine dressing. Treatment was changed on the second day to fluid-absorbent foam bandages for superficial wounds (up to IIa degrees depth) and occlusive, antiseptic moist bandages in combination with enzymatic substances for IIb degrees -III degrees burns. After the delayed demarcation, necrectomy and mesh graft transplantation were performed. All wounds healed adequately. Chemical burn traumata with nitric acid lead to specific yellow- to brown-stained wounds with slower accumulation of eschar and slower demarcation compared with thermal burns. Remaining wound eschar induced no systemic inflammation reaction. After demarcation, skin transplantation can be performed on the wounds, as is commonly done. The distinguishing feature of nitric-acid-induced chemical burns is the difficulty in differentiation and classification of burn depth. An immediate lavage should be followed by silver sulphadiazine treatment. Thereafter, fluid absorbent foam bandages or occlusive, antiseptic moist bandages should be used according to the burn depth. Slow demarcation caused a delay in performing surgical treatments. PMID- 19875348 TI - Smoking and diabetes--the double health hazard! AB - Smoking is a predictor of the transition from normoglycaemia to impaired fasting glucose and increases the risk of type 2 diabetes, independent from possible confounders. In patients with diabetes as in non-diabetics, smoking is a significant and independent risk factor for all-cause mortality and for mortality from cardiovascular disease and corononary heart disease, as well as for aggregates of fatal and non-fatal cardiovascular events. There is little doubt that smoking is a risk factor for coronary heart disease, but this risk appears to be stronger than the risk for stroke in diabetics. Pathophysiological mechanisms by which smoking causes glucose intolerance and worsens clinical outcomes in established diabetes include greater insulin resistance, impaired beta-cell function and insulin secretion, chronic low-grade inflammation, endothelial dysfunction, as well as interacting indirectly with other factors known to aggravate diabetes and lifestyle factors. Smoking cessation programs are of great importance for primary care specialists dealing with diabetes. PMID- 19875349 TI - Knee arthodesis using a modular customized intramedullary nail. AB - INTRODUCTION: Arthrodesis of the knee, particularly in infectious situations, can be achieved using either an external fixator or an intramedullary device. The objective of this study is to report the clinical, functional, and radiographic outcomes of a continuous series of 19 cases of knee arthrodesis using a customized modular intramedullary nailing system. HYPOTHESIS: The modular intramedullary nail offers a satisfactory functional result while maintaining limb length, in spite of a nonunion risk, since acting like a true endoprosthesis. MATERIAL AND METHODS: In our retrospective series of 19 patients, the main source of patients were infected total knee replacements. The nail was customized from assembling a dual surface-sanded titanium component (femoral and tibial). The Lequesne Algofunctional score and the WOMAC score were recorded, as well as the length discrepancy between the lower extremities. Arthrodesis consolidation and the nail's fit in the shaft were verified on anterior-posterior (AP) and lateral radiographs. RESULTS: Five complications were observed: one anterior cortical break, one excessive tibial rotation, two cases of delayed union, and one nail revision due to residual nail instability. The postoperative Lequesne Algofunctional score was 13/24 and the WOMAC score 57/100. The nonunion rate was 32%. From a functional point of view, the patients who did not achieve complete union and those who did had similar scores. The subjective results were not as good in patients who did not achieve final consolidation. DISCUSSION: Modular intramedullary nailing simplifies the technique, shortens the procedure, and reduces the amount of blood loss at surgery. Our nonunion rate was high, although the functional result did not seem compromised by such nonunion. The risk of long-term implant failure was not studied and requires longer follow-up studies. LEVEL OF EVIDENCE: Level IV therapeutic study. PMID- 19875351 TI - Retrovirus delivered neurotrophin-3 promotes survival, proliferation and neuronal differentiation of human fetal neural stem cells in vitro. AB - Poor survival and insufficient neuronal differentiation are the main obstacles to neural stem cell (NSC) transplantation therapy. Genetic modification of NSCs with neurotrophins is considered a promising approach to overcome these difficulties. In this study, the effects on survival, proliferation and neuronal differentiation of human fetal NSCs (hfNSCs) were observed after infection by a neurotrophin-3 (NT-3) recombinant retrovirus. The hfNSCs, from 12-week human fetal brains formed neurospheres, expressed the stem cell marker nestin and differentiated into the three main cell types of the nervous system. NT-3 recombinant retrovirus (Retro-NT-3) infected hfNSCs efficiently expressed NT-3 gene for at least 8 weeks, presented an accelerated proliferation, and therefore produced an increased number of neurospheres and after differentiation in vitro, contained a higher percentage of neuronal cells. Eight weeks after infection, 37.9+/-4.2% of hfNSCs in the Retro-NT-3 infection group expressed the neuronal marker, this was significantly higher than the control and mock infection groups. NT-3 transduced hfNSCs also displayed longer protruding neurites compared with other groups. Combined these results demonstrate that NT-3 modification promote the survival/proliferation, neuronal differentiation and growth of neurites of hfNSCs in vitro. This study proposes recombinant retrovirus mediated NT-3 modification may provide a promising means to resolve the poor survival and insufficient neuronal differentiation of NSCs. PMID- 19875352 TI - Role of the lateral hypothalamus in modulating responses of parabrachial gustatory neurons in the rat. AB - The lateral hypothalamus (LH) receives projections from the parabrachial nucleus (PBN) gustatory neurons and sends efferent projections to the PBN. To examine if the LH is involved in modulating activity of gustatory neurons in the PBN, we examined the effects of electrical stimulation and electrolytic lesions of the LH on the response of PBN gustatory neurons, using extracellular recording techniques. Among 45 PBN taste neurons recorded, 60% were affected by LH stimulation and 73% were affected by LH lesions. During LH stimulation, the responses of most affected PBN neurons were inhibited with the magnitude significantly lower than that obtained before stimulation (P<0.05). In contrast, LH lesions facilitated the response. Based on the best-stimulus category, the responses of the NaCl-best neurons to NaCl and HCl and the QHCl-best neurons to HCl and QHCl were significantly suppressed during LH stimulation (P<0.05). After lesions of the LH, however, the response to HCl in NaCl-best PBN neurons was significantly increased (P<0.05). Analysis of across-unit patterns indicated that LH stimulation decreased the correlations between NaCl and other stimuli, and increased those between QHCl and other stimuli. After LH lesions, the correlations between NaCl and other tastants were higher than those before lesions. These findings suggest that the LH mediates feeding and taste via modulating the activity and chemical selectivity of PBN gustatory neurons. PMID- 19875354 TI - Effect of the class I metabotropic glutamate receptor antagonist AIDA on certain behaviours in rats with experimental chronic hyperammonemia. AB - PURPOSE: This study examines possible interactions between behavioral effects and mGluR1 (class I metabotropic glutamate receptor) by injecting AIDA [(RS)-1 aminoindan-1,5-dicarboxylic acid] in rats with experimental chronic hyperammonemia (chHA). MATERIAL/METHODS: The effects of mGluR1 antagonist on some behaviors were tested in control groups of rats and in rats with chHA. Experimental chHA was induced by intraperitoneal injection of ammonium acetate (12 mmol/kg) for five consecutive days. We used the following behavioural tests: the open field test, the passive avoidance test and the elevated "plus" maze. RESULTS: In control rats AIDA administered intracerebroventricularly (i.c.v.) at the dose 100 nmol decreased the number of crossings and bar approaches in the open field test and impaired acquisition and recall in the passive avoidance situation. ChHA significantly inhibited locomotor and exploratory activity and profoundly impaired acquisition and recall processes in the passive avoidance test and significantly increased acute stress responses. AIDA increased locomotor activity in chHA rats (especially number of crossed fields and rearings) and produced anxiety enhancement in rats with chHA. AIDA used in rats with chHA significantly improved acquisition and retrieval processes. CONCLUSIONS: The obtained results suggest that AIDA, the antagonist of mGluR1, had beneficial effects on learning and memory in rats with experimental chronic hyperammonemia. PMID- 19875353 TI - [Positron emission tomography and evaluation of response to targeted therapies]. AB - The development of new-targeted therapies has highlighted the need to adapt the criteria used so far for radiological assessment of tumor response, but also the search for new criteria for a more appropriate evaluation. Nuclear medicine, and especially positron emission tomography (PET) offers a variety of functional imaging for early assessment of tumor response to targeted therapies. In this paper, we first describe data in the literature on PET technique with fluorodeoxyglucose (FDG) in this indication and the associated new molecules. The second part discusses the new positron-emitting tracers that are potentially interesting for the evaluation of action or efficacy of these new molecules (imaging "targeted" to specific metabolic pathways, cell proliferation, hypoxia, angiogenesis, receptors, etc.). PMID- 19875355 TI - NGAL (neutrophil gelatinase-associated lipocalin) and L-FABP after percutaneous coronary interventions due to unstable angina in patients with normal serum creatinine. AB - PURPOSE: The value of NGAL (neutrophil gelatinase-associated lipocalin) and L FABP (liver-type fatty acid binding protein) has been highlighted as a novel biomarker of detection of acute renal failure in children after cardiac surgery. Interventional cardiologists are being asked more frequently to perform percutaneous coronary intervention (PCI) and contrast nephropathy is its potentially serious complication. We aimed to prospectively assess NGAL and L FABP in patients with normal serum creatinine undergoing PCI due to unstable angina. MATERIAL AND METHODS: We measured serum NGAL, urinary NGAL and L-FABP using commercially available kits before and after 2, 4, 12, 24 and 48 hours following PCI in 25 patients. RESULTS: We found a significant rise in serum NGAL after 2 and 4 hours. Urinary NGAL and urinary L-FABP followed the same pattern. Both markers increased significantly after 4 hours and remained elevated up to 48 hours after PCI. Serum creatinine did not change significantly during the study period. CONCLUSIONS: NGAL and L-FABP may represent a sensitive early biomarkers of renal impairment after PCI. Persistently increased urinary NGAL and L-FABP may suggest renotubular damage in this population. PMID- 19875356 TI - Role of adipokines in complications related to obesity: a review. AB - Worldwide, the prevalence of overweight and obesity and associated complications is increasing. Cardiovascular complications are the most important factor determining survival and influencing clinical management. However, obesity is also associated with an increased risk of metabolic syndrome, type 2 diabetes, cancer and other diseases. The development of complications depends on the amount of body fat and its endocrine function. The hormones (leptin, adiponectin, resistin) and cytokines (TNF alpha, IL-6, PAI-1) produced by the adipose tissue are the link between obesity and obesity-related complications. The present article discusses the structure, function and clinical significance of adipokines. PMID- 19875358 TI - Proceed with caution. PMID- 19875357 TI - Bilateral partial ureteral duplication with double collecting system in horseshoe kidney. AB - The horseshoe kidney is the most common renal fusion anomaly. Approximately one third is associated with other congenital anomalies. The combination of horseshoe kidney and bilateral ureteral duplication is a very rare entity. The horseshoe kidney anomaly discovered incidentally in ultrasound examination in our patient when he was being detected for urinary incontinence. Because he had dilated renal pelvis he had undergone intravenous pyelography (IVP). Bilateral double collecting system and bilateral partial hydronephrosis was detected on IVP. Magnetic resonance urography was also performed in the same patient for better delineation. PMID- 19875359 TI - Effect of anterior cruciate ligament reconstruction and meniscectomy on length of career in National Football League athletes: a case control study. AB - BACKGROUND: Meniscal and anterior cruciate ligament (ACL) injuries are common in college football athletes. The effect of meniscectomy and/or ACL surgery on the length of an athlete's career in the National Football League (NFL) has not been well examined. HYPOTHESIS: Athletes with a history of meniscectomy or ACL surgery before the NFL combine have a shorter career than matched controls. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A database containing the injury history and career NFL statistics of athletes from 1987-2000 was used to match athletes with a history of meniscectomy and/or ACL surgery, and no other surgery or major injury, to controls without previous surgeries. Athletes were matched by position, year drafted, round drafted, and additional injury history. RESULTS: Fifty-four athletes with a history of meniscectomy, 29 with a history of ACL reconstruction, and 11 with a history of both were identified and matched with controls. Isolated meniscectomy reduced the length of career in years (5.6 vs 7.0; P = .03) and games played (62 vs 85; P = .02). Isolated ACL surgery did not significantly reduce the length of career in years or games played. Comparing the athletes with meniscectomy or ACL reconstruction to athletes with combined ACL reconstruction and meniscectomy, a history of both surgeries, resulted in a shorter career in games started (7.9 vs 35.1; P <.01), games played (41 vs 63; P = .07), and years (4.0 vs 5.8; P = .08) than a history of either surgery alone. CONCLUSION: A history of meniscectomy, but not ACL reconstruction, shortens the expected career of a professional football player. A combination of ACL reconstruction and meniscectomy may be more detrimental to an athlete's durability than either surgery alone. Further research is warranted to better understand how these injuries and surgeries affect an athlete's career and what can be done to improve the long-term outcome after treatment. PMID- 19875361 TI - Platelet-rich plasma: from basic science to clinical applications. AB - Platelet-rich plasma (PRP) has been utilized in surgery for 2 decades; there has been a recent interest in the use of PRP for the treatment of sports-related injuries. PRP contains growth factors and bioactive proteins that influence the healing of tendon, ligament, muscle, and bone. This article examines the basic science of PRP, and it describes the current clinical applications in sports medicine. This study reviews and evaluates the human studies that have been published in the orthopaedic surgery and sports medicine literature. The use of PRP in amateur and professional sports is reviewed, and the regulation of PRP by antidoping agencies is discussed. PMID- 19875360 TI - Accelerated healing of the rat Achilles tendon in response to autologous conditioned serum. AB - BACKGROUND: Despite advances in the treatment of ruptured Achilles tendon, imperfections of endogenous repair often leave patients symptomatic. Local administration of autologous conditioned serum (ACS) in patients with inflammatory, degenerative conditions has shown beneficial effects. PURPOSE: Because ACS also contains growth factors that should accelerate tendon healing, we studied the effect of ACS on the healing of transected rat Achilles tendon. STUDY DESIGN: Controlled laboratory study. METHODS: In preliminary in vitro experiments, rat tendons were incubated with ACS and the effect on the expression of Col1A1 and Col3A1 was assessed by real-time quantitative polymerase chain reaction. To test its effect in vivo, the Achilles tendons of 80 Sprague Dawley rats were transected and sutured back together. Ten rats from each group (ACS group, n = 40; control group, n = 40) were euthanized at 1, 2, 4, and 8 weeks postoperatively for biomechanical (n = 7) and histologic (n = 3) testing. Lysyl oxidase activity was assayed by a flurometric assay. The organization of repair tissue was assessed histologically with hematoxylin and eosin- and with Sirius red-stained sections, and with immunohistochemistry. RESULTS: Tendons exposed to ACS in vitro showed a greatly enhanced expression of the Col1A1 gene. The ACS treated tendons were thicker, had more type I collagen, and an accelerated recovery of tendon stiffness and histologic maturity of the repair tissue. However, there were no differences in the maximum load to failure between groups up to week 8, perhaps because lysyl oxidase activities were unchanged. CONCLUSION AND CLINICAL RELEVANCE: Overall, our study demonstrates that treatment with ACS has the potential to improve Achilles tendon healing and should be considered as a treatment modality in man. However, as strength was not shown to be increased within the parameters of this study, the clinical importance of the observed changes in humans still needs to be defined. PMID- 19875365 TI - Relationship between plasma inflammatory markers and plaque fibrous cap thickness determined by intravascular optical coherence tomography. AB - OBJECTIVE: The purpose of this study was to evaluate the relationship between human plaque fibrous cap thickness detected by intravascular optical coherence tomography (OCT) and the plasma levels of inflammatory factors in patients with coronary artery disease (CAD). METHODS AND RESULTS: OCT was used to measure the fibrous cap thickness of coronary artery atherosclerotic plaques in patients with acute myocardial infarction (AMI), unstable angina pectoris (UAP) and stable angina pectoris (SAP). Plasma levels of inflammatory factors including highly sensitive C-reactive protein (hs-CRP), IL-18 and tumour necrosis factor alpha (TNFalpha) were detected by ELISA, and peripheral white blood cell (WBC) counts were performed. The results demonstrated that the plasma levels of inflammatory factors and WBC count were correlated inversely with fibrous cap thickness (r = 0.775 for hs-CRP, r = -0.593 for IL-18, r = -0.60 for TNFalpha and r = -0.356 for WBC count). Patients with cap thickness less than 65 microm (defined to be thin cap fibroatheromas; TCFA) had higher plasma levels of inflammatory factors as well as WBC counts than those with thicker fibrous caps. Receiver operator characteristic (ROC) curves for hs-CRP, IL-18, TNFalpha and WBC count, which displayed the capability of prediction about TCFA, showed the area under the curves were 0.95, 0.86, 0.79 and 0.70 (p<0.05), respectively. ROC curve analysis confirmed that an hs-CRP cut-off at 1.66 mg/l would detect TCFA with a sensitivity of 96% and a specificity of 90%, and was the strongest independent predictor of TCFA. CONCLUSION: There is an inverse linear correlation between fibrous cap thickness and plasma levels of inflammatory markers. The plasma hs CRP concentration is the strongest independent predictor of TCFA. PMID- 19875366 TI - Low circulating androgens and mortality risk in heart failure. AB - OBJECTIVE: Deficiency of anabolic sex steroids is common in heart failure (HF). The pathophysiological implications of this phenomenon, however, have not been fully elucidated. This clinical study investigated the significance of low serum androgen levels in HF. DESIGN: Prospective cohort study. Patients and Methods In 191 consecutively recruited men with HF (mean age 64 years; New York Heart Association (NYHA) class I-IV 24%/35%/35%/6%) and reduced (ejection fraction (EF) 40%, n=95) left ventricular function total and free serum testosterone, dehydroepiandrosterone sulfate (DHEAS) and sex hormone binding globulin (SHBG) were measured. The median observation period was 859 days. RESULTS: During follow-up 53 patients (28%) died. Whereas total serum testosterone was normal in most patients (91%), free testosterone and DHEAS were reduced in 79% and 23%, respectively. DHEAS and free testosterone, but not total testosterone, were inversely associated with NYHA class (both p<0.01). Lower free testosterone and DHEAS and higher SHBG predicted all-cause mortality risk (hazard ratio (HR) 0.89, 95% CI 0.82 to 0.96 per 1 ng/dl free testosterone, p=0.004; HR 0.95, 95% CI 0.89 to 1.00 per 10 microg/dl DHEAS, p=0.058; and HR 1.18, 95% CI 1.05 to 1.33 per 10 nmol/l SHBG, p=0.006, respectively; adjusted for age and NYHA class). However, further adjustment for carefully selected confounding factors abolished these associations. CONCLUSION: In male HF patients, low serum levels of androgens are associated with adverse prognosis, but this relation is confounded by indicators of a poor health state. The results suggest that low serum androgens develop as a sequel of this progressive multifaceted systemic disorder. PMID- 19875367 TI - Single-beat estimation of the left ventricular end-diastolic pressure-volume relationship in patients with heart failure. AB - AIMS: To test a method to predict the end-diastolic pressure-volume relationship (EDPVR) from a single beat in patients with heart failure. METHODS AND RESULTS: Patients (New York Heart Association class III-IV) scheduled for mitral annuloplasty (n=9) or ventricular restoration (n=10) and patients with normal left ventricular function undergoing coronary artery bypass grafting (n=12) were instrumented with pressure-conductance catheters to measure pressure-volume loops before and after surgery. Data obtained during vena cava occlusion provided directly measured EDPVRs. Baseline end-diastolic pressure (P(m)) and volume (V(m)) were used for single-beat prediction of EDPVRs. Root-mean-squared error (RMSE) between measured and predicted EDPVRs, was 2.79+/-0.21 mm Hg. Measured versus predicted end-diastolic volumes at pressure levels 5, 10, 15 and 20 mm Hg showed tight correlations (R(2)=0.69-0.97). Bland-Altman analyses indicated overestimation at 5 mm Hg (bias: pre-surgery 44 ml (95% CI 29 to 58 ml); post surgery 35 ml (23 to 47 ml)) and underestimation at 20 mm Hg (bias: pre-surgery 57 ml (-80 to -34 ml); post-surgery -13 ml (-20 to -7.0 ml)). End-diastolic volumes were significantly different between groups and between conditions, but these differences were not dependent on the method (ie, measured versus predicted). RMSEs were not different between groups or conditions, nor dependent on V(m) or P(m), indicating that EDPVR prediction was equally accurate over a wide volume range. CONCLUSIONS: Single-beat EDPVRs obtained from hearts spanning a wide range of sizes and conditions accurately predicted directly measured EDPVRs with low RMSE. Single-beat EDPVR indices correlated well with directly measured values, but systematic biases were present at low and high pressures. The single-beat method facilitates less invasive EDPVR estimation, particularly when coupled with emerging non-invasive techniques to measure pressures and volumes. PMID- 19875368 TI - The danger of radiation exposure in the young. PMID- 19875370 TI - Risk assessment with cardiac magnetic resonance imaging in hypertrophic cardiomyopathy. PMID- 19875371 TI - Percutaneous surgery for mitral valve disease. PMID- 19875372 TI - Transradial cardiac procedures and increased radiation exposure: is it a real phenomenon? PMID- 19875373 TI - Unrecognised myocardial infarction in subjects at high vascular risk. PMID- 19875374 TI - Stress cardiomyopathy or Takotsubo syndrome. PMID- 19875375 TI - Real-time three dimensional echocardiography: current and future clinical applications. PMID- 19875376 TI - Effects of pioglitazone on subclinical atherosclerosis and insulin resistance in nondiabetic renal allograft recipients. AB - BACKGROUND: The aim of this study was to evaluate the effect of pioglitazone treatment on the progression of subclinical atherosclerosis and insulin resistance in renal allograft recipients with no preoperative history of diabetes. METHODS: Eighty-three patients without diabetes were randomly assigned to either the pioglitazone group or the control group. Carotid intima-media thickness (IMT), serum adiponectin level and lipid profile were assessed before transplantation and at 12 months after transplantation. Insulin secretory function and insulin resistance were evaluated by the oral glucose tolerance test. RESULTS: The pioglitazone group showed a significant reduction in the mean and maximum carotid IMT compared with the control group after 12 months (mean carotid IMT, 0.05 +/- 0.04 vs -0.03 +/- 0.07 mm, P < 0.001; maximum carotid IMT, 0.08 +/- 0.05 vs -0.05 +/- 0.09 mm, P < 0.001). Pioglitazone increased the adiponectin level, and the change in adiponectin was negatively correlated with carotid IMT changes. Pioglitazone treatment increased the insulin sensitivity index compared with the control group (-0.8 +/- 3.1x10(-)(2) vs +1.1 +/- 3.7x10( )(2), P = 0.036). CONCLUSIONS: These results suggest that pioglitazone treatment reduces the progression of carotid IMT and improves insulin resistance in renal allograft recipients without a history of diabetes. Trial Registration. Clinicaltrials.gov Identifier: NCT00598013. PMID- 19875377 TI - Coronary blood flow in patients with end-stage renal disease assessed by thrombolysis in myocardial infarction frame count method. AB - BACKGROUND: Myocardial ischaemia in patients with end-stage renal disease (ESRD) develops both due to the epicardial coronary artery stenosis and to the microvascular injury. We aimed to evaluate coronary blood flow in ESRD patients by means of the thrombolysis in myocardial infarction (TIMI) frame count method (TFC). In patients with ESRD, implementation of the TFC as a marker of the coronary flow abnormalities have not been previously investigated. METHODS: Thirty-nine ESRD patients on regular dialysis underwent elective coronary angiography. Coronary artery stenosis >75% was defined as significant. TFC for the three main coronary vessels was calculated. Higher TFC values reflected slower flow. RESULTS: In 19 patients (49%), significant epicardial coronary artery disease was found. Distribution of the TFC for the three main coronary arteries reflected prevalence for higher TFC values. Mean corrected TFC for the left anterior descending artery (LAD) was 34.7 +/- 16, for the circumflex artery (Cx) 41.5 +/- 25 and for the right coronary artery (RCA) 30.9 +/- 18 frames. For the three main coronary vessels, there were no statistically significant differences between the mean TFC values according to the presence or absence of the severe coronary artery stenoses on angiography (LAD: 30.2 +/- 12 vs 36.3 +/- 18; Cx: 41.5 +/- 20 vs 41.5 +/- 27; RCA: 34.9 +/- 16 vs 30.0 +/- 19, respectively). CONCLUSIONS: Our results demonstrate for the first time the reduction in blood flow velocity, assessed with TFC method, in the coronary arteries of ESRD patients. This phenomenon was observed regardless of the presence of the significant epicardial coronary artery stenosis. Therefore, TFC cannot be applied as a marker of significant coronary artery stenosis in ESRD population. PMID- 19875378 TI - Recurrence of focal segmental glomerular sclerosis (FSGS) after renal transplantation. PMID- 19875379 TI - The effect of dialysis modality on phosphate control : haemodialysis compared to haemodiafiltration. The Pan Thames Renal Audit. AB - BACKGROUND AND OBJECTIVES: Hyperphosphataemia is a primary risk factor for patients with end-stage kidney failure. Phosphate clearance by traditional thrice weekly standard haemodialysis is inadequate for patients achieving recommended dietary protein goals. We investigated whether phosphate control was improved by adding convective clearance with haemodiafiltration. METHODS: We audited pre midweek session calcium and phosphate levels in 5366 adult patients, 4515 treated by haemodialysis and 851 by on-line haemodiafiltration. RESULTS: The cohorts were similar for age, sex and dialysis vintage. Serum phosphate was lower in the haemodiafiltration cohort (1.42 +/- 0.61 mmol/l) compared to the haemodialysis cohort (1.53 +/- 0.53 mmol/l; P < 0.001), as was the calcium-phosphate product (3.31 +/- 1.53 vs 3.5 +/- 1.33 mmol(2)/l(2), respectively; P < 0.001) despite a shorter treatment session time (3.68 +/- 0.44 vs 3.92 +/- 0.49 h; P < 0.001). Parathyroid hormone levels were similar. CONCLUSIONS: The results of this audit suggest that haemodiafiltration offers improved phosphate control compared to standard intermittent haemodialysis. PMID- 19875380 TI - The profile of adult nephrology patients admitted to the Renal Unit of the Universitas Tertiary Hospital in Bloemfontein, South Africa from 1997 to 2006. AB - BACKGROUND: This paper reports a retrospective audit of new patients referred to the Renal Unit at Universitas Academic Hospital in Bloemfontein, South Africa for the decade 1997-2006. METHODS: All the files kept in the Renal Unit were reviewed for the main clinical presentation, a definitive pathological diagnosis (if obtained), age, race and gender of the patients. No consultations from other disciplines were included. RESULTS: One thousand two hundred and sixteen patients were included in the study. The main clinical presentations were as follows: chronic renal failure (CRF), 461 (37.9%); nephrotic syndrome, 203 (16.7%); hypertension, 161 (13.2%); and abnormal urinary findings, 128 (10.5%). The nephrotic syndrome was the most common indication for renal biopsy, and histological investigation revealed focal segmental glomerulosclerosis in 46 (3.8%) patients, minimal change in 23 (1.9%), membranoproliferative disease in 36 (3.0%) and membranous glomerular disease (MN) in 28 (2.3%). In CRF, hypertension was suspected in 236/461 (51.2%) cases but was proven histologically in only 13 (2.8%) patients. CONCLUSIONS: Socio-political factors impacting on access to healthcare most likely had an influence on the referral pattern of patients during this period. The largest group of patients were referred to our institution late in their disease with CRF, often requiring renal replacement therapy, and a definitive diagnosis was seldom possible at that stage. With the limited availability of dialysis facilities, the need for early detection and preventative measures with regard to renal disease in this community is evident. PMID- 19875381 TI - A proteomic investigation of ligand-dependent HSP90 complexes reveals CHORDC1 as a novel ADP-dependent HSP90-interacting protein. AB - Structural studies of the chaperone HSP90 have revealed that nucleotide and drug ligands induce several distinct conformational states; however, little is known how these conformations affect interactions with co-chaperones and client proteins. Here we use tandem affinity purification and LC-MS/MS to investigate the proteome-wide effects of ATP, ADP, and geldanamycin on the constituents of the human HSP90 interactome. We identified 52 known and novel components of HSP90 complexes that are regulated by these ligands, including several co-chaperones. Interestingly, our results also show that geldanamycin treatment causes HSP90 complexes to become significantly enriched for core transcription machinery, suggesting that HSP90 inhibition may have broad based effects on transcription and RNA processing. We further characterized a novel ADP-dependent HSP90 interaction with the cysteine- and histidine-rich domain (CHORD)-containing protein CHORDC1. We show that this interaction is stimulated by high ADP:ATP ratios in cell lysates and in vitro with purified recombinant proteins. Furthermore, we demonstrate that this interaction is dependent upon the ability of HSP90 to bind nucleotides and requires the presence of a linker region between the CHORD domains in CHORDC1. Together these findings suggest that the HSP90 interactome is dynamic with respect to nucleotide and drug ligands and that pharmacological inhibition of HSP90 may stimulate the formation of specific complexes. PMID- 19875383 TI - Metanephric stromal tumor arising in a patient with neurofibromatosis type 1 syndrome. AB - Metanephric stromal tumor (MST) is a recently recognized benign renal stromal tumor. MST is thought to be part of a spectrum of benign metanephric renal lesions, which also includes the epithelial lesion metanephric adenoma and the mixed stromal-epithelial lesion metanephric adenofibroma. Metanephric lesions may represent hyperdifferentiated counterparts to Wilms' tumor (WT). MST characteristically shows renovascular angiodysplasia and juxtaglomerular (JG) cell hyperplasia. This is remarkably similar to the renal pathology described in neurofibromatosis-1 (NF-1) syndrome, a condition which is also associated with WT. Here, we report the first case of MST arising in a patient with NF-1. The patient presented with hypertension, and the MST was associated with florid angiodysplasia and JG cell hyperplasia. This case tightens the link between NF-1, WT, and MST. PMID- 19875382 TI - Proteomics-based refinement of Deinococcus deserti genome annotation reveals an unwonted use of non-canonical translation initiation codons. AB - Deinococcaceae are a family of extremely radiation-tolerant bacteria that are currently subjected to numerous studies aimed at understanding the molecular mechanisms for such radiotolerance. To achieve a comprehensive and accurate annotation of the Deinococcus deserti genome, we performed an N terminus-oriented characterization of its proteome. For this, we used a labeling reagent, N tris(2,4,6-trimethoxyphenyl)phosphonium acetyl succinimide, to selectively derivatize protein N termini. The large scale identification of N-tris(2,4,6 trimethoxyphenyl)phosphonium acetyl succinimide-modified N-terminal-most peptides by shotgun liquid chromatography-tandem mass spectrometry analysis led to the validation of 278 and the correction of 73 translation initiation codons in the D. deserti genome. In addition, four new genes were detected, three located on the main chromosome and one on plasmid P3. We also analyzed signal peptide cleavages on a genome-wide scale. Based on comparative proteogenomics analysis, we propose a set of 137 corrections to improve Deinococcus radiodurans and Deinococcus geothermalis gene annotations. Some of these corrections affect important genes involved in DNA repair mechanisms such as polA, ligA, and ddrB. Surprisingly, experimental evidences were obtained indicating that DnaA (the protein involved in the DNA replication initiation process) and RpsL (the S12 ribosomal conserved protein) translation is initiated in Deinococcaceae from non canonical codons (ATC and CTG, respectively). Such use may be the basis of specific regulation mechanisms affecting replication and translation. We also report the use of non-conventional translation initiation codons for two other genes: Deide_03051 and infC. Whether such use of non-canonical translation initiation codons is much more frequent than for other previously reported bacterial phyla or restricted to Deinococcaceae remains to be investigated. Our results demonstrate that predicting translation initiation codons is still difficult for some bacteria and that proteomics-based refinement of genome annotations may be helpful in such cases. PMID- 19875384 TI - TREX1 gene variant in neuropsychiatric systemic lupus erythematosus. PMID- 19875385 TI - Matricide: a critique of the literature. AB - Matricide, the killing of mothers by their biological children, is a very rare event, comprising less that 2% of all U.S. homicides in which the victim-offender relationship is known. This manuscript examines more than 20 years of U.S. homicides to determine the age and gender characteristics of matricide offenders. These data reveal that most mothers are killed by their adult sons. Daughters younger than 18 years are the most infrequent killers of mothers. This article examines the incidence of parricide, the involvement of sons and daughters in matricidal incidents, and synthesizes the literature in terms of offender gender. Special attention is given to female matricide offenders, given the lack of research currently available with respect to this population. Implications for practice, policy, and research are discussed. PMID- 19875387 TI - The 'left' ventricle during pulsatile mechanical assistance: reliability of cardiac output monitoring with an uncalibrated pulse contour method. PMID- 19875386 TI - Risk profile and benefits from Gp IIb-IIIa inhibitors among patients with ST segment elevation myocardial infarction treated with primary angioplasty: a meta regression analysis of randomized trials. AB - AIMS: Several randomized trials and a previous meta-analysis have shown significant benefits from Gp IIb-IIIa inhibitors, especially abciximab. Recent randomized trials (BRAVE-3 and HORIZON trials) have shown no benefits from adjunctive Gp IIb-IIIa inhibitors on the top of clopidogrel administration. However, the relatively low mortality may have hampered the conclusion of these recent trials. Thus, the aim of the current study was to perform an update meta analysis of randomized trials on adjunctive Gp IIb-IIIa inhibitors in primary angioplasty, and to evaluate by meta-regression analysis, whether the results may be related to risk profile. METHODS AND RESULTS: We obtained results from all randomized trials evaluating the benefits of adjunctive Gp IIb-IIIa inhibitors among STEMI patients undergoing primary angioplasty. The literature was scanned by formal searches of electronic databases (MEDLINE and CENTRAL) from January 1990 to September 2008. The following key words were used: randomized trial, myocardial infarction, reperfusion, primary angioplasty, Gp IIb-IIIa inhibitors, abciximab, tirofiban, and eptifibatide. Clinical endpoint was mortality at 30 days. Major bleeding complications were assessed as safety endpoint. No language restriction was applied. A total of 16 randomized trials were finally included in the meta-analysis, involving 10 085 patients (5094 or 50.5% in the Gp IIb-IIIa inhibitors group and 4991 or 49.5% in the control group. Gp IIb-IIIa inhibitors did not reduce 30 day mortality (2.8 vs. 2.9%, P = 0.75) or re-infarction (1.5 vs. 1.9%, P = 0.22), but were associated with higher risk of major bleeding complications (4.1 vs. 2.7%, P = 0.0004). However, we observed a significant relationship between patient's risk profile and benefits from adjunctive Gp IIb IIIa inhibitors in terms of death (P = 0.008) but not re-infarction (P = 0.25). CONCLUSION: This meta-analysis shows a significant relationship between benefits in mortality from Gp IIb-IIIa inhibitors and patient's risk profile. Thus, Gp IIb IIIa inhibitors should be strongly considered among high-risk patients. PMID- 19875388 TI - Prevalence and risk factors related to infections of cardiac resynchronization therapy devices. AB - AIMS: Device-related infections (DRI) are not well understood in patients implanted with a cardiac resynchronization therapy (CRT) device. The aims of this study were: (i) to evaluate the prevalence of CRT DRI; (ii) to establish the factors predictive of CRT DRI. METHODS AND RESULTS: Between January 2001 and May 2007, CRT implantation was performed in 303 patients (247 men, 82%). The mean follow-up was 31 +/- 19 months. Population characteristics were a mean age of 70 +/- 10 years old; 56 female; aetiology includes (202 dilated and 101 ischaemic cardiomyopathy); NYHA class 3.2 +/- 0.3; LVEF (26 +/- 6%), and a QRS width of 171 +/- 31 ms. Thirteen patients developed a DRI: endocarditis in four, pocket erosion in three, pocket abscess in five, and septicaemia in one. The prevalence of DRI was 4.3%. By univariate analysis, predictive factors of DRI were: procedure time (skin to skin: median of 85 vs. 57.5 min; P = 0.03), re intervention (54 vs. 6.5%; P < 0.0001), haematoma (31 vs. 8.6% P = 0.01), lead dislodgement (23 vs. 6.2%; P = 0.03), dialysis (23.1 vs. 1.72%; P = 0.003), and procedure type [CRT-ICD (8.6%) vs. CRT PM (1.6%) or system up-grade (1.5%); P = 0.03]. Significant correlations were found between re-intervention and lead dislodgement (r = 0.8; P < 0.001), haematoma (r = 0.2; P < 0.001). Four independent predictive factors of DRI were identified as procedure time (P = 0.002); dialysis (P = 0.0001); re-intervention (P = 0.006), and procedure type (CRT-ICD vs. other procedures; P = 0.01). CONCLUSION: This study found that the prevalence of CRT DRI is close to 4.3% at 2.6 years (1.7% per year incidence). Four independent predictive factors of infections were identified including re intervention, procedure time, dialysis, and primo CRT-ICD implantation. These parameters should be part of the risk-benefit evaluation in patients selected for CRT implantation. PMID- 19875389 TI - The role of head computer tomographic scans on the management of MICU patients with neurological dysfunction. AB - Neurological dysfunction is common in patients admitted to the medical intensive care unit (MICU). However, the indications for head imaging in those patients are unclear. The objective of this study was to assess whether clinical variables would be useful in selecting patients who are likely to have an abnormality on head computerized tomographic (CT) scanning and to determine the impact of such scans on management decisions. We reviewed the charts of 740 patients admitted to our MICU between October 2002 and July 2004. A total of 123 patients (16.6%) had a head CT scan performed, with a new finding being present in 26 (21.1%) patients. In the patients with a new CT finding, there was a change in diagnosis in 11 (42%) patients and a change in treatment in 6 (23%) patients. Logistic regression analysis failed to determine any clinical characteristic that could predict a new finding on the CT scan. This study suggests that clinicians should have a low threshold for ordering a CT scan in MICU patients with acute neurological dysfunction. PMID- 19875390 TI - Bi-level positive airway pressure ventilation in pediatric oncology patients with acute respiratory failure. AB - The aim of the study was to describe our experience with bi-level positive airway pressure (BiPAP) ventilation in oncology children with acute respiratory failure, hospitalized in a single tertiary pediatric tertiary center. This was a retrospective cohort study of all pediatric oncology patients in our center admitted to the intensive care unit with acute hypoxemic or hypercarbic respiratory failure from January 1999 through May 2006, who required mechanical ventilation with BiPAP. Fourteen patients met the inclusion criteria with a total of 16 events of respiratory failure or impending failure: 12 events were hypoxemic, 1 was combined hypercarbic and hypoxemic, and 3 had severe respiratory distress. Shortly after BiPAP ventilation initiation, there was a statistically significant improvement in the respiratory rate (40.4 +/- 9.3 to 32.5 +/- 10.1, P < .05] and a trend toward improvement in arterial partial pressure of oxygen (PaO(2); 71.3 +/- 32.7 to 104.6 +/- 45.6, P = .055). The improvement in the respiratory status was sustained for at least 12 hours. In 12 (75%) events there was a need for sedation during ventilation; 12 children needed inotropic support during the BiPAP ventilation. Bi-level positive airway pressure ventilation failed in 3 (21%) children who were switched to conventional ventilation. All of them have died during the following days. One child was recategorized to receive palliative care while on BiPAP ventilator and was not intubated. In 12 of 16 BiPAP interventions (75%; 11 patients), the children survived to pediatric intensive care unit (PICU) discharge without invasive ventilation. No major complications were noted during BiPAP ventilation. Bi-level positive airway pressure ventilation is well tolerated in pediatric oncology patients suffering from acute respiratory failure and may offer noninferior outcomes compared with those previously described for conventional invasive ventilation. It appears to be a feasible initial option in children with malignancy experiencing acute respiratory failure. PMID- 19875391 TI - Muscle-derived cell injection to treat anal incontinence due to obstetric trauma: pilot study with 1 year follow-up. AB - OBJECTIVE: To treat anal incontinence due to obstetric external anal sphincter disruption via injection of autologous myoblast cells. DESIGN: Observational pilot study. SETTING: University hospital and district hospital PATIENTS: 10 women suffering from anal incontinence due to obstetric anal sphincter injury, refractory to conventional non-surgical therapy. INTERVENTIONS: Autologous myoblasts were cultured from a pectoralis muscle biopsy, harvested, and injected into the external anal sphincter defect using direct ultrasound guidance. MAIN OUTCOME MEASURES: Wexner incontinence score, anal squeeze pressures, and quality of life 12 months after injection. Safety and technical feasibility. RESULTS: The procedure was well tolerated and no adverse events were observed. At 12 months the Wexner incontince score had decreased by a mean of 13.7 units (95% CI, -16.3 to -11.2), anal squeeze pressures were unchanged, and overall quality of life scores improved by a median of 30 points (95% CI, 25 to 42). Anal squeeze pressures did rise significantly at 1 month and 6 months post-injection (p = 0.03). CONCLUSIONS: Injection of autologous myoblasts is safe, well tolerated, and significantly improves symptoms of anal incontinence due to obstetric anal sphincter trauma. PMID- 19875392 TI - Gastro-oesophageal reflux symptoms and the risks of oesophageal cancer: are the effects modified by smoking, NSAIDs or acid suppressants? AB - OBJECTIVE: To measure the extent to which risks of oesophageal cancers associated with gastro-oesophageal reflux (GOR) are modified by common factors including smoking, non-steroidal anti-inflammatory drugs (NSAIDs) and acid suppressant medications. DESIGN AND SETTING: Population-based case-control study. PARTICIPANTS: Cases were patients with oesophageal (OAC; n = 365) or gastro oesophageal junction (GOJAC; n = 426) adenocarcinomas, or squamous cell carcinomas (OSCC; n = 303). Controls were sampled from a population register (n = 1580). MAIN OUTCOME MEASURE: Odds ratio and 95% confidence interval. RESULTS: Frequent (at least weekly) symptoms of GOR were associated with significant 6.4 fold, 4.6-fold and 2.2-fold increased risks of OAC, GOJAC and OSCC, respectively. Under models examining effects of combined exposure, patients with frequent GOR symptoms who were also heavy smokers had markedly higher OAC risks (OR = 12.3, 95% CI 6.3 to 24.0) than those with frequent GOR who did not smoke (OR = 6.8, 95% CI 3.6 to 12.9). Similar patterns were observed for GOJAC and OSCC. Among people with frequent GOR symptoms, regular use of aspirin/NSAIDs was associated with almost two-thirds lower OAC risks (OR = 4.8, 95% CI 2.5 to 9.2) than non-users (13.9, 95% CI 6.5 to 30.0). In contrast, among those with frequent GOR symptoms, users of acid suppressants had similar OAC risks (OR 7.8, 95% CI 5.2 to 11.8) to non-users (OR 5.3, 95% CI 3.2 to 9.0). CONCLUSIONS: People experiencing frequent GOR symptoms have markedly increased risks of OAC and GOJAC, and this effect may be greater amongst smokers. Use of aspirin and NSAIDs, but not acid suppressants, significantly reduced the risks of oesophageal cancers associated with GOR. PMID- 19875393 TI - Bone health in HIV infection. AB - INTRODUCTION: Osteoporosis is among the chronic problems emerging as the human immunodeficiency virus (HIV)-positive population ages. SOURCES OF DATA: We reviewed the English language bibliography using Pubmed 2.0, Web of Science and Embase for relevant abstracts and articles. AREAS OF AGREEMENT: The prevalence of low bone mineral density (BMD) and fracture is increased in the HIV-positive population. AREAS OF CONTROVERSY: The pathogenesis is multifactorial; there is some evidence that HIV infection is an independent risk factor and that highly active antiretroviral therapy has adverse skeletal effects. GROWING POINTS: Physicians should routinely review the bone health of all HIV patients. AREAS TIMELY FOR DEVELOPING RESEARCH: More studies of the mechanisms of bone loss, the skeletal effects of antiretroviral therapy and the therapeutic outcome of bone protective therapy in HIV-positive individuals are needed. PMID- 19875394 TI - Neuropsychological function 5 years after cardiac surgery and the effect of psychological distress. AB - Research has shown conflicting results with regard to the influence of depression and anxiety on neuropsychological performance following coronary artery bypass graft (CABG) surgery. Notably, the independent effects of depression and anxiety have not been examined among CABG candidates in the longer term where it is has been suggested that these patients show marked cognitive deterioration. A neuropsychological test battery and measures of psychological distress were completed by 86 CABG patients and 50 nonsurgical control participants at baseline and 6 months, whereas 75 patients and 36 controls, respectively, completed a 5 year follow-up. In CABG patients, cognitive and affective depressive symptoms were independently associated with lower and worse performance on the Boston Naming Test, Purdue Peg Board, and Digit Symbol Coding 6 months after surgery, whereas at 5-year follow-up an effect for Digit Symbol persisted, and an association was also observed for the Trail Making Test (TMT). On average, CABG patients performed worse on TMT and Digit Symbol at 6 months, whereas at 5-year follow-up their performance was worse on short-term delayed verbal recall. The results among the CABG patients did not show a consistent pattern of association between psychological distress and those neuropsychological domains that were on average significantly lower than a nonsurgical control group. The results here also support the use of nonbiased statistical methodology to document dysfunction among heterogeneous cognitive domains after CABG surgery. PMID- 19875395 TI - Animal models for atrial fibrillation: clinical insights and scientific opportunities. AB - Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. A variety of animal models have been used to study the pathophysiology of AF, including molecular basis, ion-current determinants, anatomical features, and macroscopic mechanisms. In addition, animal models play a key role in the development of new therapeutic approaches, whether drug-based, molecular therapeutics, or device-related. This article discusses the various types of animal models that have been used for AF research, reviews the principle mechanisms governing atrial arrhythmias in each model, and provides some guidelines for model selection for various purposes. PMID- 19875396 TI - Brugada syndrome ECG provoked by the selective serotonin reuptake inhibitor fluvoxamine. AB - A patient with an SCN5A p.W822X nonsense mutation, localized in the transmembrane region DII-S4 of the Na(v)1.5 sodium channel and leading to a non-expression of the mutant allele, was prescribed the selective serotonin reuptake inhibitor (SSRI) fluvoxamine (Floxyfral), 100 mg per day. His normal baseline ECG changed to a characteristic Brugada-Type-1-ECG pattern. To investigate whether fluvoxamine may reduce the cardiac sodium current, the effect of this drug was studied on the wild-type voltage-gated cardiac sodium channel Na(v)1.5 stably expressed in HEK293 cells. Patch-clamp recording showed a 50% inhibition of the current at a concentration of 57.3 microM. In our patient, no arrhythmia occurred but the proarrhythmic potential of SSRI in patients with SCN5A mutations cannot be excluded. Therefore, we advise 12-lead ECG control after administering SSRI in these patients. PMID- 19875397 TI - The difference in autonomic denervation and its effect on atrial fibrillation recurrence between the standard segmental and circumferential pulmonary vein isolation techniques. AB - AIMS: This study examined the difference in autonomic modification (AM) and its effect on paroxysmal atrial fibrillation (PAF) recurrence between segmental pulmonary vein isolation (S-PVI) and circumferential PVI (C-PVI). METHODS AND RESULTS: Successful S-PVI or C-PVI with a basket catheter was achieved in 120 consecutive PAF patients. Serial 24 Holter-recordings were obtained before, immediately, and 1, 3, 6, 12 months after the PVI to analyse the heart rate variability (HRV). Nineteen patients were excluded from analysis because of additional ablation for recurrent PAF after successful PVI. Among the residual 101 patients, 33 had PAF recurrences (S-PVI = 44.0%, C-PVI = 21.6%) at 1 year of follow-up. The root mean square of successive differences and high-frequency power reflecting parasympathetic nervous activity were significantly lower in patients with and without PAF recurrences after C-PVI and patients without PAF recurrences after S-PVI than patients with PAF recurrences after S-PVI (P < 0.005 0.0001). However, there were no significant differences in any HRV parameters in the immediate aftermath of PVI among the patients without PAF recurrences after S PVI and those with and without PAF recurrences after C-PVI. CONCLUSION: Although additional radiofrequency ablation for AM may be recommended after S-PVI to reduce PAF recurrences, it should be carefully determined after C-PVI. PMID- 19875398 TI - Monitoring capabilities of cardiac rhythm management devices. AB - Since the advent of the first generation pacemakers, solely providing rate support, we have witnessed a technological outburst in the type and complexity of implantable devices. The introduction of implantable cardioverter defibrillators and later of cardiac resynchronization therapy devices enriched our therapeutic arsenal for the management of patients with heart failure and/or high risk of sudden cardiac death. In addition, during the last decade, newer generation cardiac rhythm management devices (CRMs) have been capable to provide a continuously expanding pool of diagnostic information derived by novel monitoring capabilities. Although at present the clinical role of this information is undervalued, it is evident that the clinical exploitation of data derived by CRMs may transform the standards of care for our patients by providing timely applied individualized diagnosis and treatment. In this context, even in the absence of solid data supporting the use of this information in everyday clinical practice, improving our familiarity with currently available monitoring algorithms is a prerequisite for the electrophysiologist who keeps in pace with the rapidly evolving technologies of CRMs and is prepared for their future role on clinical practice. PMID- 19875399 TI - Prevalence and spectrum of abnormal electrocardiograms in patients with an isolated congenital left ventricular aneurysm or diverticulum. AB - AIMS: Congenital left ventricular aneurysm (LVA) and diverticulum (LVD) are rare cardiac anomalies and can be associated with ECG abnormalities and rhythm disturbances. We sought to investigate the prevalence and the spectrum of ECG abnormalities in such patients. METHODS AND RESULTS: We assessed 125 patients with isolated LVA or LVD for the prevalence of ECG abnormalities and compared the findings to an age- and gender-matched control group. The 12-lead ECG patterns were evaluated according to commonly used criteria and were classified into three subgroups (distinct, mildly, and minor). Fifty-four of the 125 patients (43.2%) had normal and 71 (56.8%) abnormal ECGs. Mean age was 66 years. Forty-nine (39.2%) were male. Distinct abnormal ECG patterns were more prevalent in patients with LVD (38.2 vs. 15.8%, P = 0.04), and apical location of the anomaly (36.6 vs. 16.6%, P = 0.02). Older age (>66 years) was associated with a trend for a higher prevalence of abnormal ECG pattern (33 vs. 18%, P = 0.06), whereas gender had no influence (32 vs. 16%, P = 0.14). This study also shows that the sensitivity, specificity, positive predictive value and negative predictive value of a 12-lead ECG for the diagnosis of LVA or LVD are low. CONCLUSION: This large single-centre study suggests that the prevalence of abnormal ECG patterns in patients with isolated LVA or LVD is as high as 56.8%. However, ECG is not specific and sensitive to be used as a screening tool in such patients. PMID- 19875400 TI - 'Hospital at home' care model as an effective alternative in the management of decompensated chronic heart failure. AB - AIMS: The 'Hospital at home' (HaH) model avoids hospital admission by transferring healthcare and treatment to the patient's home. We aimed to compare the effectiveness and direct healthcare costs of treating elderly patients with decompensated heart failure (HF) using HaH care vs. inpatient hospital care (IHC) in a cardiology unit. METHODS AND RESULTS: Eighty patients aged over 65 years who presented at the emergency department with decompensated HF were randomly assigned to IHC or HaH. All patients were studied for 1 year. Seventy-one patients completed the study, of these 34 were admitted to cardiology and 37 received HaH care. No significant differences were found in baseline characteristics, including comorbidity, functional status, and health-related quality of life. Clinical outcomes were similar after initial admission and also after the 12 months of follow-up. Death or re-admission due to HF or another cardiovascular event occurred in 19 patients in IHC and 20 in HaH (P = 0.88). Changes in functional status and health-related quality of life over the follow up period were not significantly different. The average cost of the initial admission was 4502 +/- 2153 euro in IHC and 2541 +/- 1334 euro in HaH (P < 0.001). During 12 months of follow-up, the average expenditure was 4619 +/- 7679 euro and 3425 +/- 4948 euro (P = 0.83) respectively. CONCLUSION: Hospital at home care allows an important reduction in the costs during the index episode compared with hospital care, whilst maintaining similar outcomes with respect to cardiovascular mortality and morbidity and quality of life at 1 year follow-up. PMID- 19875401 TI - Impaired cellular contractile function in thiamine-deficient rat cardiomyocytes. PMID- 19875402 TI - Clinical trial participation: are we studying the patients we are trying to treat? PMID- 19875403 TI - Transplantation with survivin-engineered mesenchymal stem cells results in better prognosis in a rat model of myocardial infarction. AB - AIMS: To investigate the effect of survivin (SVV)-engineered mesenchymal stem cells (MSCs) on post-infarction cardiac performance and remodelling in rats. METHODS AND RESULTS: Mesenchymal stem cells from male Sprague-Dawley rat bone marrow were infected with the self-inactive lentiviral vector GFP-wre-CMV/LTR and Flap-Ubiqutin promoter (GCFU) carrying green fluorescent protein (GFP) gene and SVV recombinant vector (GCFU-SVV). In vitro, modification with SVV increased the secretion of vascular endothelial growth factor (VEGF) by 1.28-fold under hypoxic conditions. In vivo, after permanent left anterior descending artery occlusion, rats were randomized (n = 18 per group) to receive intra-myocardial injections of 100 microL of phosphate-buffered saline without cells (group vehicle) or containing 2 million MSC(GFP) (group MSC(GFP)) or MSC(SVV) (group MSC(SVV)) cells. Cellular survival assessed by reverse transcriptase-polymerase chain reaction for GFP in the MSC(SVV) group was 2.5-fold higher at 7 days and 4.3-fold higher at 28 days after transplantation than in the MSC(GFP) group. When compared with transplantation with MSC(GFP), transplantation with MSC(SVV) further upregulated VEGF expression at 7 and 28 days after myocardial infarction (MI), increased capillary density by 38%, reduced the infarct size by 12.7%, significantly inhibited collagen deposition, and further improved cardiac function at 28 days after MI. CONCLUSION: Transplantation with SVV-engineered MSCs by lentiviral vector leads to better prognosis for MI by enhancing cellular survival. PMID- 19875404 TI - The role of Lamin A/C mutations in Danish patients with idiopathic dilated cardiomyopathy. PMID- 19875405 TI - Decreased soluble TWEAK levels predict an adverse prognosis in patients with chronic stable heart failure. AB - AIMS: Tumour necrosis factor (TNF)-like weak inducer of apoptosis (sTWEAK) is a multifunctional cytokine that has recently been implicated in cardiovascular disease. The aim of this study was to define the plasma levels of sTWEAK in patients with stable chronic heart failure and evaluate the possibility of a prognostic impact of sTWEAK. METHODS AND RESULTS: sTWEAK levels in plasma samples from 364 patients with systolic heart failure were compared with 36 control patients. The median levels of sTWEAK in heart failure patients were significantly lower than those of the control group (217 pg/mL, interquartile range 136-311 vs. 325 pg/mL, interquartile range 250-394 pg/mL). Moreover, sTWEAK levels were lower in patients with ischaemic cardiomyopathy vs. dilated cardiomyopathy and correlated significantly with functional NYHA class. Patients with plasma levels below a ROC-derived cut-off value of 227 pg/mL had a significantly higher mortality rate after 4 years. Upon univariate and multivariate analyses, sTWEAK levels below 227 pg/mL emerged as an independent predictor of subsequent death. CONCLUSION: In contrast to other cytokines shown to be increased in heart failure patients, plasma levels of sTWEAK are significantly reduced in chronic stable heart failure. In addition, lower plasma levels of sTWEAK predict an adverse prognosis independent of established risk markers such as NT-proBNP. PMID- 19875406 TI - Sleep apnoea induces cardiac electrical instability assessed by T-wave alternans in patients with congestive heart failure. AB - AIMS: To assess the involvement of sleep apnoea in nocturnal sudden cardiac death (SCD) by evaluating cardiac electrical instability using T-wave alternans (TWA), a risk marker for lethal cardiac arrhythmias, and severity of sleep apnoea in congestive heart failure (CHF) patients. METHODS AND RESULTS: A total of 40 CHF patients simultaneously underwent overnight simplified respiratory polygraphy and 24 h continuous electrocardiography. Peak TWA during both daytime and nighttime were calculated by the modified moving average method. The patients were divided into two groups; 30 patients with daytime predominant TWA (whose peak TWA was higher during daytime than during nighttime) and 10 with nighttime predominant. Apnoea-hypopnoea index (AHI) was significantly higher in patients with nighttime predominant TWA than in those with daytime predominant (35.9 +/- 8.1 vs. 23.9 +/- 14.4 events/h, P = 0.02), and was an independent predictor of nighttime predominant TWA (odds ratio, 1.08; 95% confidence interval, 1.01-1.16; P = 0.03). Moreover, peak TWA during the night was correlated positively with AHI (P < 0.001), and AHI was an independent determinant of nocturnal TWA value (r(2) = 0.27, P = 0.009). CONCLUSION: In CHF patients, sleep apnoea induces cardiac electrical instability manifested as TWA, reflecting increased risk of nocturnal SCD. Moreover, some CHF patients with sleep apnoea exhibit nighttime predominant TWA. Therefore, TWA should also be evaluated during the night. PMID- 19875407 TI - Is taking part in clinical trials good for your health? A cohort study. AB - AIMS: The prognosis of patients included in clinical trials is often better than might be anticipated from epidemiological data. Patients volunteering to take part in a study might be unrepresentative of the potential treatment population or the trial itself may confer benefit by offering closer supervision. METHODS AND RESULTS: A total of 2332 consecutive patients (average +/- SD age 70.1 +/- 10.8; 26% female) who presented to a community heart failure clinic were diagnosed as having heart failure due to left ventricular systolic dysfunction. All patients were asked whether they would be prepared to take part in clinical research projects at their initial visit. During a median follow-up in survivors of 55.7 months (interquartile range 30.4-74.3), 792 (34%) patients died. Agreeing to take part in clinical trials strongly predicted a good outcome (approximately halving the risk of death). In multivariate modelling, willingness to take part [hazard ratio (95% confidence intervals) 0.33 (0.26-0.40)] was a predictor of good outcome independent of age, severity of left ventricular dysfunction, renal function, sodium levels, drug use, and comorbidities. In a subset in whom N terminal pro-B type natriuretic peptide (NT-proBNP) was available (n = 1256), agreeing to take part in trials remained an independent predictor of survival with log [NT-proBNP]. CONCLUSION: Those patients with chronic heart failure who express a willingness to take part in a clinical trial, appear to have a better prognosis than those who do not. PMID- 19875408 TI - Rationale and design of Ferinject assessment in patients with IRon deficiency and chronic Heart Failure (FAIR-HF) study: a randomized, placebo-controlled study of intravenous iron supplementation in patients with and without anaemia. AB - AIMS: Iron deficiency (ID) and anaemia are common in patients with chronic heart failure (CHF). The presence of anaemia is associated with increased morbidity and mortality in CHF, and ID is a major reason for the development of anaemia. Preliminary studies using intravenous (i.v.) iron supplementation alone in patients with CHF and ID have shown improvements in symptom status. FAIR-HF (Clinical Trials.gov NCT00520780) was designed to determine the effect of i.v. iron repletion therapy using ferric carboxymaltose on self-reported patient global assessment (PGA) and New York Heart Association (NYHA) in patients with CHF and ID. METHODS AND RESULTS: This is a multi-centre, randomized, double blind, placebo-controlled study recruiting ambulatory patients with symptomatic CHF with LVEF < or = 40% (NYHA II) or < or =45% (NYHA III), ID [ferritin <100 ng/mL or ferritin 100-300 ng/mL when transferrin saturation (TSAT) < 20%], and haemoglobin 9.5-13.5 g/dL. Patients were randomized in a 2:1 ratio to receive ferric carboxymaltose (Ferinject((R))) 200 mg iron i.v. or saline i.v. weekly until iron repletion (correction phase), then monthly until Week 24 (maintenance phase). Primary endpoints are (i) self-reported PGA at Week 24 and (ii) NYHA class at Week 24, adjusted for baseline NYHA class. CONCLUSION: This study will provide evidence on the efficacy and safety of iron repletion with ferric carboxymaltose in CHF patients with ID with and without anaemia. PMID- 19875409 TI - Adherence to medication according to sex and age in the CHARM programme. AB - AIMS: Although many patients with heart failure have incomplete adherence to prescribed medications, predisposing factors remain unclear. This analysis investigates factors associated with adherence, with particular emphasis on age and sex. METHODS AND RESULTS: A multivariable regression analysis of 7599 heart failure patients from the CHARM trial was done to evaluate factors associated with adherence. Adherence was measured as the proportion of time patients took more than 80% of study medication. The mean age was 66 years (SD 11) and 31.5% (n = 2400) were women. Women were slightly less adherent than men (87.3 vs. 89.8%, P = 0.002), even in adjusted, multivariable models (treatment, P = 0.006; placebo P = 0.004; and overall P < 0.001). However, all-cause mortality was lower in women (21.5%) than in men (25.3%) (adjusted hazard ratio, 0.77; 95% CI, 0.69-0.86; P < 0.001), but patients with a low adherence regardless of sex had a higher mortality. Age, severity of heart failure, number of medications, and smoking status were not associated with adherence. CONCLUSION: Women, particularly those <75 years of age, were less likely to be adherent in this large sample of patients with symptomatic heart failure. Understanding factors associated with adherence may provide opportunities for intervention. PMID- 19875410 TI - Timing of eplerenone initiation and outcomes in patients with heart failure after acute myocardial infarction complicated by left ventricular systolic dysfunction: insights from the EPHESUS trial. AB - AIMS: To test the hypothesis that an earlier post-acute myocardial infarction (AMI) eplerenone initiation in patients with left ventricular systolic dysfunction (LVSD) and heart failure (HF) is associated with better long-term outcomes. METHODS AND RESULTS: The 6632 patients of the EPHESUS study were randomized from day 3 to 14 after the index AMI (median = 7 days), of these 3319 were assigned to eplerenone. We analysed the differential effects of time-to eplerenone initiation vs. placebo, based on the median time to initiation of treatment (<7 days-'earlier', > or =7days-'later'). Effects on outcomes were evaluated over a mean 16-month follow-up, using Cox proportional hazards regression analysis. The earlier eplerenone initiation (<7 days) reduced the risk of all-cause mortality by 31% (P = 0.001) when compared with the 'earlier' placebo' and also reduced the risks of cardiovascular (CV) hospitalization/CV mortality by 24% (P < 0.0001) and sudden cardiac death (SCD) by 34% (P < 0.0001). In contrast, later eplerenone initiation (> or =7 days) had no significant effect on outcomes. Interactions between time-to-randomization and treatment were significant. These associations remained substantially unchanged after risk adjustment in multivariable models. CONCLUSION: An earlier eplerenone administration (3-7days) post-AMI improved outcomes in patients with LVSD and HF. This benefit was not observed when eplerenone was initiated later (> or =7days). PMID- 19875411 TI - Severe cardiomyopathy following treatment with the tumour necrosis factor-alpha inhibitor adalimumab for Crohn's disease. AB - Adalimumab belongs to the group of tumour necrosis factor-alpha inhibitors and has been approved for the treatment Crohn's Disease since 2007. Herein we report a severe adverse reaction to adalimumab in a 25-year-old female patient. One week after the initial-dose of adalimumab (160 mg), which was initiated due to an acute exacerbation of Crohn's disease, the patient developed a fulminant cardiomyopathy. In severe cardiogenic shock, the patient required an extracorporeal membrane-oxygenation system for 8 days until cardiac recovery. PMID- 19875414 TI - Ghrelin resistance in heart failure or why failing cardiomyocytes do not produce ghrelin: the same problem? PMID- 19875415 TI - IPD--the Immuno Polymorphism Database. AB - The Immuno Polymorphism Database (IPD) (http://www.ebi.ac.uk/ipd/) is a set of specialist databases related to the study of polymorphic genes in the immune system. The IPD project works with specialist groups or nomenclature committees who provide and curate individual sections before they are submitted to IPD for online publication. The IPD project stores all the data in a set of related databases. IPD currently consists of four databases: IPD-KIR, contains the allelic sequences of Killer-cell Immunoglobulin-like Receptors, IPD-MHC, is a database of sequences of the Major Histocompatibility Complex of different species; IPD-human platelet antigens, alloantigens expressed only on platelets and IPD-ESTDAB, which provides access to the European Searchable Tumour cell-line database, a cell bank of immunologically characterised melanoma cell lines. The data is currently available online from the website and ftp directory. PMID- 19875416 TI - Random DNA fragmentation allows detection of single-copy, single-exon alterations of copy number by oligonucleotide array CGH in clinical FFPE samples. AB - Genomic technologies, such as array comparative genomic hybridization (aCGH), increasingly offer definitive gene dosage profiles in clinical samples. Historically, copy number profiling was limited to large fresh-frozen tumors where intact DNA could be readily extracted. Genomic analyses of pre-neoplastic tumors and diagnostic biopsies are often limited to DNA processed by formalin fixation and paraffin-embedding (FFPE). We present specialized protocols for DNA extraction and processing from FFPE tissues utilizing DNase processing to generate randomly fragmented DNA. The protocols are applied to FFPE clinical samples of varied tumor types, from multiple institutions and of varied block age. Direct comparative analyses with regression coefficient were calculated on split-sample (portion fresh/portion FFPE) of colorectal tumor samples. We show equal detection of a homozygous loss of SMAD4 at the exon-level in the SW480 cell line and gene-specific alterations in the split tumor samples. aCGH application to a set of archival FFPE samples of skin squamous cell carcinomas detected a novel hemizygous deletion in INPP5A on 10q26.3. Finally we present data on derivative of log ratio, a particular sensitive detector of measurement variance, for 216 sequential hybridizations to assess protocol reliability over a wide range of FFPE samples. PMID- 19875417 TI - Single-cell transcriptional analysis of taste sensory neuron pair in Caenorhabditis elegans. AB - The nervous system is composed of a wide variety of neurons. A description of the transcriptional profiles of each neuron would yield enormous information about the molecular mechanisms that define morphological or functional characteristics. Here we show that RNA isolation from single neurons is feasible by using an optimized mRNA tagging method. This method extracts transcripts in the target cells by co-immunoprecipitation of the complexes of RNA and epitope-tagged poly(A) binding protein expressed specifically in the cells. With this method and genome-wide microarray, we compared the transcriptional profiles of two functionally different neurons in the main C. elegans gustatory neuron class ASE. Eight of the 13 known subtype-specific genes were successfully detected. Additionally, we identified nine novel genes including a receptor guanylyl cyclase, secreted proteins, a TRPC channel and uncharacterized genes conserved among nematodes, suggesting the two neurons are substantially different than previously thought. The expression of these novel genes was controlled by the previously known regulatory network for subtype differentiation. We also describe unique motif organization within individual gene groups classified by the expression patterns in ASE. Our study paves the way to the complete catalog of the expression profiles of individual C. elegans neurons. PMID- 19875418 TI - The RNA polymerase activity of SARS-coronavirus nsp12 is primer dependent. AB - An RNA-dependent RNA polymerase (RdRp) is the central catalytic subunit of the RNA-synthesizing machinery of all positive-strand RNA viruses. Usually, RdRp domains are readily identifiable by comparative sequence analysis, but biochemical confirmation and characterization can be hampered by intrinsic protein properties and technical complications. It is presumed that replication and transcription of the approximately 30-kb severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) RNA genome are catalyzed by an RdRp domain in the C terminal part of nonstructural protein 12 (nsp12), one of 16 replicase subunits. However, thus far full-length nsp12 has proven refractory to expression in bacterial systems, which has hindered both the biochemical characterization of coronavirus RNA synthesis and RdRp-targeted antiviral drug design. Here, we describe a combined strategy involving bacterial expression of an nsp12 fusion protein and its in vivo cleavage to generate and purify stable SARS-CoV nsp12 (106 kDa) with a natural N-terminus and C-terminal hexahistidine tag. This recombinant protein possesses robust in vitro RdRp activity, as well as a significant DNA-dependent activity that may facilitate future inhibitor studies. The SARS-CoV nsp12 is primer dependent on both homo- and heteropolymeric templates, supporting the likeliness of a close enzymatic collaboration with the intriguing RNA primase activity that was recently proposed for coronavirus nsp8. PMID- 19875419 TI - Two modules in the BRC repeats of BRCA2 mediate structural and functional interactions with the RAD51 recombinase. AB - The breast and ovarian cancer suppressor protein BRCA2 controls the RAD51 recombinase in reactions that lead to homologous DNA recombination (HDR). BRCA2 binds RAD51 via eight conserved BRC repeat motifs of approximately 35 amino acids, each with a varying capacity to bind RAD51. BRC repeats both promote and inhibit RAD51 assembly on different DNA substrates to regulate HDR, but the structural basis for these functions is unclear. Here, we demarcate two tetrameric clusters of hydrophobic residues in the BRC repeats, interacting with distinct pockets in RAD51, and show that the co-location of both modules within a single BRC repeat is necessary for BRC-RAD51 binding and function. The two modules comprise the sequence FxxA, known to inhibit RAD51 assembly by blocking the oligomerization interface, and a previously unrecognized tetramer with the consensus sequence LFDE, which binds to a RAD51 pocket distinct from this interface. The LFDE motif is essential in BRC repeats for modes of RAD51 binding both permissive and inhibitory to RAD51 oligomerization. Targeted insertion of point mutations in RAD51 that disrupt the LFDE-binding pocket impair its assembly at DNA damage sites in living cells. Our findings suggest a model for the modular architecture of BRC repeats that provides fresh insight into the mechanisms regulating homologous DNA recombination. PMID- 19875420 TI - Analysis of 23 million US hospitalizations: uninsured children have higher all cause in-hospital mortality. AB - BACKGROUND: The number of uninsured children in the USA is increasing while the impact on children's health of being uninsured remains largely uncharacterized. We analyzed data from more than 23 million US children to evaluate the effect of insurance status on the outcome of US pediatric hospitalization. METHODS: In our analysis of two well-known large inpatient databases, we classified patients less than 18 years old as uninsured (self-pay) or insured (including Medicaid or private insurance). We adjusted for gender, race, age, geographic region, hospital type, admission source using regression models. In-hospital death was the primary outcome and secondary outcomes were hospital length of stay and total hospital charges adjusted to 2007 dollars. RESULTS: The crude in-hospital mortality was 0.75% for uninsured versus 0.47% for insured children, with adjusted mortality rates of 0.74 and 0.46%, respectively. On multivariate analysis, uninsured compared with insured patients had an increased mortality risk (odds ratio: 1.60, 95% CI: 1.45-1.76). The excess mortality in uninsured children in the US was 37.8%, or 16,787, of the 38,649 deaths over the 18 period of the study. CONCLUSION: Children who were hospitalized without insurance have significantly increased all-cause in-hospital mortality as compared with children who present with insurance. PMID- 19875421 TI - Parental stress is associated with poor sleep quality in parents caring for children with developmental disabilities. AB - OBJECTIVE: This study examined the psychosocial predictors of poor sleep quality in parents caring for children with developmental disabilities. Methods Sixty seven parents of children with developmental disabilities and 42 parents of typically developing children completed the Pittsburgh Sleep Quality Index, and measures of parental stress, child problem behaviors, and social support. Results Parents of children with developmental disabilities reported poorer sleep quality. Further, the majority of these parents met the established 'poor sleepers' criterion. The strongest predictor of poor sleep quality was parental stress. This finding withstood adjustment for a number of potential confounders. Conclusions Parental stress is associated with poor sleep quality in parents of children with developmental disabilities. The monitoring and management of sleep issues in these parental caregivers should be a priority for health professionals. PMID- 19875423 TI - National audit shows improving survival rates from bowel cancer but worrying regional variations in case management. PMID- 19875424 TI - Prediction rules in cervical spine injury. PMID- 19875425 TI - Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial. AB - OBJECTIVE: To evaluate the effectiveness of an active strategy to implement the validated Canadian C-Spine Rule into multiple emergency departments. DESIGN: Matched pair cluster randomised trial. SETTING: University and community emergency departments in Canada. Participants 11 824 alert and stable adults presenting with blunt trauma to the head or neck at one of 12 hospitals. INTERVENTIONS: Six hospitals were randomly allocated to the intervention and six to the control. At the intervention sites, active strategies were used to implement the Canadian C-Spine Rule, including education, policy, and real time reminders on radiology requisitions. No specific intervention was introduced to alter the behaviour of doctors requesting cervical spine imaging at the control sites. MAIN OUTCOME MEASURE: Diagnostic imaging rate of the cervical spine during two 12 month before and after periods. RESULTS: Patients were balanced between control and intervention sites. From the before to the after periods, the intervention group showed a relative reduction in cervical spine imaging of 12.8% (95% confidence interval 9% to 16%; 61.7% v 53.3%; P=0.01) and the control group a relative increase of 12.5% (7% to 18%; 52.8% v 58.9%; P=0.03). These changes were significant when both groups were compared (P<0.001). No fractures were missed and no adverse outcomes occurred. CONCLUSIONS: Implementation of the Canadian C-Spine Rule led to a significant decrease in imaging without injuries being missed or patient morbidity. Final imaging rates were much lower at intervention sites than at most US hospitals. Widespread implementation of this rule could lead to reduced healthcare costs and more efficient patient flow in busy emergency departments worldwide. TRIAL REGISTRATION: Clinical trials NCT00290875. PMID- 19875426 TI - Effect of tailored practice and patient care plans on secondary prevention of heart disease in general practice: cluster randomised controlled trial. AB - OBJECTIVE: To test the effectiveness of a complex intervention designed, within a theoretical framework, to improve outcomes for patients with coronary heart disease. DESIGN: Cluster randomised controlled multicentre trial. SETTING: General practices in Northern Ireland and the Republic of Ireland, regions with different healthcare systems. PARTICIPANTS: 903 patients with established coronary heart disease registered with one of 48 practices. INTERVENTION: Tailored care plans for practices (practice based training in prescribing and behaviour change, administrative support, quarterly newsletter), and tailored care plans for patients (motivational interviewing, goal identification, and target setting for lifestyle change) with reviews every four months at the practices. Control practices provided usual care. MAIN OUTCOME MEASURES: The proportion of patients at 18 month follow-up above target levels for blood pressure and total cholesterol concentration, and those admitted to hospital, and changes in physical and mental health status (SF-12). RESULTS: At baseline the numbers (proportions) of patients above the recommended limits were: systolic blood pressure greater than 140 mm Hg (305/899; 33.9%, 95% confidence interval 30.8% to 33.9%), diastolic blood pressure greater than 90 mm Hg (111/901; 12.3%, 10.2% to 14.5%), and total cholesterol concentration greater than 5 mmol/l (188/860; 20.8%, 19.1% to 24.6%). At the 18 month follow-up there were no significant differences between intervention and control groups in the numbers (proportions) of patients above the recommended limits: systolic blood pressure, intervention 98/360 (27.2%) v control, 133/405 (32.8%), odds ratio 1.51 (95% confidence interval 0.99 to 2.30; P=0.06); diastolic blood pressure, intervention 32/360 (8.9%) v control, 40/405 (9.9%), 1.40 (0.75 to 2.64; P=0.29); and total cholesterol concentration, intervention 52/342 (15.2%) v control, 64/391 (16.4%), 1.13 (0.63 to 2.03; P=0.65). The number of patients admitted to hospital over the 18 month study period significantly decreased in the intervention group compared with the control group: 107/415 (25.8%) v 148/435 (34.0%), 1.56 (1.53 to 2.60; P=0.03). CONCLUSIONS: Admissions to hospital were significantly reduced after an intensive 18 month intervention to improve outcomes for patients with coronary heart disease, but no other clinical benefits were shown, possibly because of a ceiling effect related to improved management of the disease. TRIAL REGISTRATION: Current Controlled Trials ISRCTN24081411. PMID- 19875427 TI - A practical guide to interpretation and clinical application of personal genomic screening. PMID- 19875428 TI - Four US drug companies pay $124m for defrauding Medicaid. PMID- 19875430 TI - The curious case of charles darwin and homeopathy. AB - In 1849, Charles Darwin was so ill that he was unable to work one out of every 3 days, and after having various troubling symptoms for 2-12 years, he wrote to a friend that he was 'going the way of all flesh'. He sought treatment from Dr James Manby Gully, a medical doctor who used water cure and homeopathic medicines. Despite being highly skeptical of these treatments, he experienced a dramatic improvement in his health, though some of his digestive and skin symptoms returned various times in his life. He grew to appreciate water cure, but remained skeptical of homeopathy, even though his own experiments on insectivore plants using what can be described as homeopathic doses of ammonia salts surprised and shocked him with their significant biological effect. Darwin even expressed concern that he should publish these results. Two of Darwin's sons were as incredulous as he was, but their observations confirmed the results of his experiments. Darwin was also known to have read a book on evolution written by a homeopathic physician that Darwin described as similar to his own but 'goes much deeper.' PMID- 19875429 TI - Diaphragmatic breathing reduces exercise-induced oxidative stress. AB - Diaphragmatic breathing is relaxing and therapeutic, reduces stress, and is a fundamental procedure of Pranayama Yoga, Zen, transcendental meditation and other meditation practices. Analysis of oxidative stress levels in people who meditate indicated that meditation correlates with lower oxidative stress levels, lower cortisol levels and higher melatonin levels. It is known that cortisol inhibits enzymes responsible for the antioxidant activity of cells and that melatonin is a strong antioxidant; therefore, in this study, we investigated the effects of diaphragmatic breathing on exercise-induced oxidative stress and the putative role of cortisol and melatonin hormones in this stress pathway. We monitored 16 athletes during an exhaustive training session. After the exercise, athletes were divided in two equivalent groups of eight subjects. Subjects of the studied group spent 1 h relaxing performing diaphragmatic breathing and concentrating on their breath in a quiet place. The other eight subjects, representing the control group, spent the same time sitting in an equivalent quite place. Results demonstrate that relaxation induced by diaphragmatic breathing increases the antioxidant defense status in athletes after exhaustive exercise. These effects correlate with the concomitant decrease in cortisol and the increase in melatonin. The consequence is a lower level of oxidative stress, which suggests that an appropriate diaphragmatic breathing could protect athletes from long-term adverse effects of free radicals. PMID- 19875431 TI - Auricular Acupunctures are Effective for the Prevention of Postoperative Agitation in Old Patients. AB - Postoperative cognitive problems and delirium are not uncommon in the elderly. We reported four cases in which auricular acupunctures on the 'Shenmen' and 'Point Zero' points successfully managed postoperative problematic behaviors of the three patients with dementia and the one patient postoperatively demonstrating an agitated behavior. PMID- 19875432 TI - The herb medicine formula "chong lou fu fang" increases the cytotoxicity of chemotherapeutic agents and down-regulates the expression of chemotherapeutic agent resistance-related genes in human gastric cancer cells in vitro. AB - The herb medicine formula "Chong Lou Fu Fang" (CLFF) has efficacy in inhibiting the proliferation of human gastric cancer in vitro and in vivo. To explore the potentially useful combination of CLFF with chemotherapeutic agents commonly used in gastric cancer therapy, we assess the interaction between CLFF and these chemotherapeutic agents in both SGC-7901 cell lines and BGC-823 cell lines using a median effect analysis and apoptosis analysis, and we also investigate the influence of CLFF on chemotherapeutic agent-associated gene expression. The synergistic analysis indicated that CLFF had a synergistic effect on the cytotoxicity of 5-fluorouracil (5-FU) in a relative broad dose inhibition range (20-95% fraction affected in SGC-7901cell lines and 5-65% fraction affected in BGC-823 cell lines), while the synergistic interaction between CLFF and oxaliplatin or docetaxel only existed in a low dose inhibition range (<=50% fraction affected in both cell lines). Combination of CLFF and chemotherapeutic agents could also induce apoptosis in a synergistic manner. After 24 h, CLFF alone or CLFF combination with chemotherapeutic agents could significantly suppress the levels of expression of chemotherapeutic agent resistance related genes in gastric cancer cells. Our findings indicate that there are useful synergistic interactions between CLFF and chemotherapeutic agents in gastric cancer cells, and the possible mechanisms might be partially due to the down regulation of chemotherapeutic agent resistance related genes and the synergistic apoptotic effect. PMID- 19875433 TI - Therapeutic Potential of Polar and Non-Polar Extracts of Cyanthillium cinereum In Vitro. AB - Cyanthillium cinereum (Less.) H. Rob. (Asteraceae) has been traditionally known for its medicinal properties, all aspects of which are yet to be exploited. This study was aimed at investigating the therapeutic potential of polar (methanolic and aqueous) and nonpolar (hexane and chloroform) crude extracts of the whole plant. Several parameters including free-radical (DPPH(*), ABTS(*+), H(2)O(2) and (*)OH) scavenging, reducing power, protection of DNA against oxidative damage, cytotoxicity, inhibition of oxidative hemolysis in erythrocytes, total phenolic content and inhibition of lipid peroxidation were examined. All the free-radical generating assay models demonstrated positive scavenging efficiency with differential but considerable magnitudes for the four extracts. However, only the hexane extract showed significant H(2)O(2) scavenging effect. Lipid peroxidation was estimated by thiobarbituric acid-malondialdehyde (MDA) reaction, and a high degree of inhibition was shown by all the extracts. Reducing power of the polar extracts was higher than the non-polar ones. All extracts showed a concentration dependent increase in phenolic contents. Oxidative damage to erythrocytes was hindered by all extracts in diverse degrees. XTT assay showed that all extracts have mild cytotoxic property. The aqueous extract evidently demonstrated protective effect on pBR322 plasmid DNA against oxidative breakdown. These results suggested the potential of C. cinereum as medicine against free-radical associated oxidative damage and related degenerative diseases involving metabolic stress, genotoxicity and cytotoxicity. PMID- 19875434 TI - An Overture for eCAM: Science, Technology and Innovation Initiation for Prosperous, Healthy Nepal. AB - Nepal the "Shangri-La" in the lap of the Himalayas is gearing up for modern times as it starts rebuilding after a decade of senseless violence and destruction. The nation one of the poorest in the global development index is rich in natural resources and biodiversity. Reports of medicinal plants far exceeding those recorded and reported so far are encouraging and at the same time concerns for medicinal plants under threat as a result of overexploitation are emerging from Nepal. The harsh mountain terrains, lack of industrialization and harnessing potentiality of its areas of strength; water; natural resources and tourism make it poor in per capita income which averages ~ 300 US$, with half the population living under >1$ a day. Nepal is beginning to realize that the way ahead is only possible through the path of Science and Technology (ST). Nepal Academy of Science and Technology formerly known as Royal Academy of Science and Technology organized the fifth national conference held every 4 years that took place in the capital Kathmandu during November 10-12, 2008. The ST initiation event saw the participation of ~ 1400 people representing over 150 organizations from the country and experts from abroad. The theme for the fifth national meet was "Science, Technology and Innovation for Prosperous Nepal". Complementary and Alternative Medicine (CAM) was an important theme in the event as the realization for the need of ST research focused in CAM for harnessing the chemo diversity potential was univocally approved. PMID- 19875435 TI - Alternative isoleucine synthesis pathway in cyanobacterial species. AB - Cyanothece sp. ATCC 51142 is an aerobic N(2)-fixing and hydrogen-producing cyanobacterium. Isotopomer analysis of its amino acids revealed an identical labelling profile for leucine and isoleucine when Cyanothece 51142 was grown mixotrophically using 2-(13)C-labelled glycerol as the main carbon source. This indicated that Cyanothece 51142 employs the atypical alternative citramalate pathway for isoleucine synthesis, with pyruvate and acetyl-CoA as precursors. Utilization of the citramalate pathway was confirmed by an enzyme assay and LC MS/MS analysis. Furthermore, the genome sequence of Cyanothece 51142 shows that the gene encoding the key enzyme (threonine ammonia-lyase) in the normal isoleucine pathway is missing. Instead, the cce_0248 gene in Cyanothece 51142 exhibits 53 % identity to the gene encoding citramalate synthase (CimA, GSU1798) from Geobacter sulfurreducens. Reverse-transcription PCR indicated that the cce_0248 gene is expressed and its transcriptional level is lower in medium with isoleucine than in isoleucine-free medium. Additionally, a blast search for citramalate synthase and threonine ammonia-lyase implies that this alternative isoleucine synthesis pathway may be present in other cyanobacteria, such as Cyanothece and Synechococcus. This suggests that the pathway is more widespread than originally thought, as previous identifications of the citramalate pathway are limited to mostly anaerobic bacteria or archaea. Furthermore, this discovery opens the possibility that such autrotrophic micro-organisms may be engineered for robust butanol and propanol production from 2-ketobutyrate, which is an intermediate in the isoleucine biosynthesis pathway. PMID- 19875436 TI - Ensifer, Phyllobacterium and Rhizobium species occupy nodules of Medicago sativa (alfalfa) and Melilotus alba (sweet clover) grown at a Canadian site without a history of cultivation. AB - Phage-resistant and -susceptible bacteria from nodules of alfalfa and sweet clover, grown at a site without a known history of cultivation, were identified as diverse genotypes of Ensifer, Rhizobium and Phyllobacterium species based on sequence analysis of ribosomal (16S and 23S rRNA) and protein-encoding (atpD and recA) genes, Southern hybridization/RFLP and a range of phenotypic characteristics. Among phage-resistant bacteria, one genotype of Rhizobium sp. predominated on alfalfa (frequency approximately 68 %) but was recovered infrequently ( approximately 1 %) from sweet clover. A second genotype was isolated infrequently only from alfalfa. These genotypes fixed nitrogen poorly in association with sweet clover and Phaseolus vulgaris, but were moderately effective with alfalfa. They produced a near-neutral reaction on mineral salts agar containing mannitol, which is atypical of the genus Rhizobium. A single isolate of Ensifer sp. and two of Phyllobacterium sp. were recovered only from sweet clover. All were highly resistant to multiple antibiotics. Phylogenetic analysis indicated that Ensifer sp. strain T173 is closely related to, but separate from, the non-symbiotic species 'Sinorhizobium morelense'. Strain T173 is unique in that it possesses a 175 kb symbiotic plasmid and elicits ineffective nodules on alfalfa, sweet clover, Medicago lupulina and Macroptilium atropurpureum. The two Phyllobacterium spp. were non-symbiotic and probably represent bacterial opportunists. Three genotypes of E. meliloti that were symbiotically effective with alfalfa and sweet clover were encountered infrequently. Among phage-susceptible isolates, two genotypes of E. medicae were encountered infrequently and were highly effective with alfalfa, sweet clover and Medicago polymorpha. The ecological and practical implications of the findings are discussed. PMID- 19875437 TI - The inositol regulon controls viability in Candida glabrata. AB - Inositol is essential in eukaryotes, and must be imported or synthesized. Inositol biosynthesis in Saccharomyces cerevisiae is controlled by three non essential genes that make up the inositol regulon: ScINO2 and ScINO4, which together encode a heterodimeric transcriptional activator, and ScOPI1, which encodes a transcriptional repressor. ScOpi1p inhibits the ScIno2-ScIno4p activator in response to extracellular inositol levels. An important gene controlled by the inositol regulon is ScINO1, which encodes inositol-3-phosphate synthase, a key enzyme in inositol biosynthesis. In the pathogenic yeast Candida albicans, homologues of the S. cerevisiae inositol regulon genes are 'transcriptionally rewired'. Instead of regulating the CaINO1 gene, CaINO2 and CaINO4 regulate ribosomal genes. Another Candida species that is a prevalent cause of infections is Candida glabrata; however, C. glabrata is phylogenetically more closely related to S. cerevisiae than C. albicans. Experiments were designed to determine if C. glabrata homologues of the inositol regulon genes function similarly to S. cerevisiae or are transcriptionally rewired. CgINO2, CgINO4 and CgOPI1 regulate CgINO1 in a manner similar to that observed in S. cerevisiae. However, unlike in S. cerevisiae, CgOPI1 is essential. Genetic data indicate that CgOPI1 is a repressor that affects viability by regulating activation of a target of the inositol regulon. PMID- 19875439 TI - Epidemiology, variable genetic organization and regulation of the EDIN-B toxin in Staphylococcus aureus from bacteraemic patients. AB - EDIN-B (epidermal cell differentiation inhibitor-B; also termed C3Stau) is an exotoxin of Staphylococcus aureus which ADP-ribosylates and inactivates Rho GTP binding proteins. The EDIN-B gene (edin-B) and the gene for exfoliative toxin D (etd) make up the central part of a recently described pathogenicity island. Here we evaluated the prevalence and genetic organization of the edin-B/etd pathogenicity island in invasive S. aureus isolates, and characterized edin-B transcription and EDIN-B production using artificial constructs transduced in S. aureus strains RN6390 and Newman. We found that eight out of 121 (7 %) S. aureus blood culture isolates harbour edin-B, which is organized in three novel variants of the original edin-B/etd pathogenicity island. In the serum of patients infected with edin-B-positive S. aureus, significant titres of anti-EDIN-B antibodies could be detected. Regulation of edin-B transcription depended on the sarA but not on the agr regulatory system. Furthermore, retrieval of EDIN-B protein secreted by S. aureus RN6390 required the presence of alpha2 macroglobulin to inhibit the activity of extracellular proteases. These data suggest that the EDIN-B toxin is produced during human infection, is part of a highly variable pathogenicity island and can be controlled by the sarA gene regulon and secreted bacterial proteases. PMID- 19875438 TI - Identification and functional characterization of a gene for the methanol : N,N' dimethyl-4-nitrosoaniline oxidoreductase from Mycobacterium sp. strain JC1 (DSM 3803). AB - Mycobacterium sp. strain JC1 is able to grow on methanol as a sole source of carbon and energy using methanol : N,N'-dimethyl-4-nitrosoaniline oxidoreductase (MDO) as a key enzyme for primary methanol oxidation. Purified MDO oxidizes ethanol and formaldehyde as well as methanol. The Mycobacterium sp. strain JC1 gene for MDO (mdo) was cloned, sequenced, and determined to have an open reading frame of 1272 bp. Northern blot and promoter analysis revealed that mdo transcription was induced in cells grown in the presence of methanol. Northern blotting together with RT-PCR also showed that the mdo gene was transcribed as monocistronic mRNA. Primer extension analysis revealed that the transcriptional start site of the mdo gene is located 21 bp upstream of the mdo start codon. An mdo-deficient mutant of Mycobacterium sp. strain JC1 did not grow with methanol as a sole source of carbon and energy. PMID- 19875440 TI - Differential interaction of the E3 ligase parkin with the proteasomal subunit S5a and the endocytic protein Eps15. AB - Parkin is a multidomain E3 ligase associated with autosomal recessive Parkinson disease. The N-terminal ubiquitin-like domain (Ubld) of parkin functions with the S5a proteasomal subunit, positioning substrate proteins for degradation. In addition the parkin Ubld recruits the endocytotic protein Eps15, allowing the E3 ligase to ubiquinate Eps15 distal from its parkin-interacting site. The recognition sequences in the S5a subunit and Eps15 for the parkin Ubld are ubiquitin-interacting motifs (UIM). Each protein has two UIM sequences separated by a 50-residue spacer in S5a, but only approximately 5 residues in Eps15. In this work we used NMR spectroscopy to determine how the parkin Ubld recognizes the proteasomal subunit S5a compared with Eps15, a substrate for ubiquitination. We show that Eps15 contains two flexible alpha-helices each encompassing a UIM sequence. The alpha-helix surrounding UIM II is longer than that for UIM I, a situation that is reversed from S5a. Furthermore, we show the parkin Ubld preferentially binds to UIM I in the S5a subunit. This interaction is strongly diminished in a K48A substitution, found near the center of the S5a interacting surface on the parkin Ubld. In contrast to S5a, parkin recruits Eps15 using both its UIM sequences resulting in a larger interaction surface that includes residues from beta1 and beta2, not typically known to interact with UIM sequences. These results show that the parkin Ubld uses differential surfaces to recruit UIM regions from the S5a proteasomal subunit compared with Eps15 involved in cell signaling. PMID- 19875441 TI - Oxidative half-reaction of arabidopsis thaliana sulfite oxidase: generation of superoxide by a peroxisomal enzyme. AB - Vertebrate forms of the molybdenum-containing enzyme sulfite oxidase possess a b type cytochrome prosthetic group that accepts reducing equivalents from the molybdenum center and passes them on to cytochrome c. The plant form of the enzyme, on the other hand, lacks a prosthetic group other than its molybdenum center and utilizes molecular oxygen as the physiological oxidant. Hydrogen peroxide is the ultimate product of the reaction. Here, we present data demonstrating that superoxide is produced essentially quantitatively both in the course of the reaction of reduced enzyme with O(2) and during steady-state turnover and only subsequently decays (presumably noncatalytically) to form hydrogen peroxide. Rapid-reaction kinetic studies directly following the reoxidation of reduced enzyme demonstrate a linear dependence of the rate constant for the reaction on [O(2)] with a second-order rate constant of k(ox) = 8.7 x 10(4) +/- 0.5 x 10(4) m(-1)s(-1). When the reaction is carried out in the presence of cytochrome c to follow superoxide generation, biphasic time courses are observed, indicating that a first equivalent of superoxide is generated in the oxidation of the fully reduced Mo(IV) state of the enzyme to Mo(V), followed by a slower oxidation of the Mo(V) state to Mo(VI). The physiological implications of plant sulfite oxidase as a copious generator of superoxide are discussed. PMID- 19875442 TI - Bordetella adenylate cyclase toxin promotes calcium entry into both CD11b+ and CD11b- cells through cAMP-dependent L-type-like calcium channels. AB - Adenylate cyclase toxin (ACT), a 200 kDa protein, is an essential virulence factor for Bordetella pertussis, the bacterium that causes whooping cough. ACT is a member of the pore-forming RTX (repeats-in-toxin) family of proteins that share a characteristic calcium-binding motif of Gly- and Asp-rich nonapeptide repeats and a marked cytolytic or cytotoxic activity. In addition, ACT exhibits a distinctive feature: it has an N-terminal calmodulin-dependent adenylate cyclase domain. Translocation of this domain into the host cytoplasm results in uncontrolled production of cAMP, and it has classically been assumed that this surge in cAMP is the basis for the toxin-mediated killing. Several members of the RTX family of toxins, including ACT, have been shown to induce intracellular calcium increases, through different mechanisms. We show here that ACT stimulates a raft-mediated calcium influx, through its cAMP production activity, that activates PKA, which in turn activates calcium channels with L-type properties. This process is shown to occur both in CD11b(+) and CD11b(-) cells, suggesting a common mechanism, independent of the toxin receptor. We also show that this ACT induced calcium influx does not correlate with the toxin-induced cytotoxicity. PMID- 19875443 TI - Engineering monolignol 4-O-methyltransferases to modulate lignin biosynthesis. AB - Lignin is a complex polymer derived from the oxidative coupling of three classical monolignols. Lignin precursors are methylated exclusively at the meta positions (i.e. 3/5-OH) of their phenyl rings by native O-methyltransferases, and are precluded from substitution of the para-hydroxyl (4-OH) position. Ostensibly, the para-hydroxyls of phenolics are critically important for oxidative coupling of phenoxy radicals to form polymers. Therefore, creating a 4-O-methyltransferase to substitute the para-hydroxyl of monolignols might well interfere with the synthesis of lignin. The phylogeny of plant phenolic O-methyltransferases points to the existence of a batch of evolutionarily "plastic" amino acid residues. Following one amino acid at a time path of directed evolution, and using the strategy of structure-based iterative site-saturation mutagenesis, we created a novel monolignol 4-O-methyltransferase from the enzyme responsible for methylating phenylpropenes. We show that two plastic residues in the active site of the parental enzyme are vital in dominating substrate discrimination. Mutations at either one of these separate the evolutionarily tightly linked properties of substrate specificity and regioselective methylation of native O methyltransferase, thereby conferring the ability for para-methylation of the lignin monomeric precursors, primarily monolignols. Beneficial mutations at both sites have an additive effect. By further optimizing enzyme activity, we generated a triple mutant variant that may structurally constitute a novel phenolic substrate binding pocket, leading to its high binding affinity and catalytic efficiency on monolignols. The 4-O-methoxylation of monolignol efficiently impairs oxidative radical coupling in vitro, highlighting the potential for applying this novel enzyme in managing lignin polymerization in planta. PMID- 19875444 TI - Thiolated tRNAs of Trypanosoma brucei are imported into mitochondria and dethiolated after import. AB - All mitochondrial tRNAs in Trypanosoma brucei derive from cytosolic tRNAs that are in part imported into mitochondria. Some trypanosomal tRNAs are thiolated in a compartment-specific manner. We have identified three proteins required for the thio modification of cytosolic tRNA(Gln), tRNA(Glu), and tRNA(Lys). RNA interference-mediated ablation of these proteins results in the cytosolic accumulation non-thio-modified tRNAs but does not increase their import. Moreover, in vitro import experiments showed that both thio-modified and non-thio modified tRNA(Glu) can efficiently be imported into mitochondria. These results indicate that unlike previously suggested the cytosol-specific thio modifications do not function as antideterminants for mitochondrial tRNA import. Consistent with these results we showed by using inducible expression of a tagged tRNA(Glu) that it is mainly the thiolated form that is imported in vivo. Unexpectedly, the imported tRNA becomes dethiolated after import, which explains why the non thiolated form is enriched in mitochondria. Finally, we have identified two genes required for thiolation of imported tRNA(Trp) whose wobble nucleotide is subject to mitochondrial C to U editing. Interestingly, down-regulation of thiolation resulted in an increase of edited tRNA(Trp) but did not affect growth. PMID- 19875445 TI - Role for X-linked Inhibitor of apoptosis protein upstream of mitochondrial permeabilization. AB - Apoptosis is controlled by a signaling equilibrium between prosurvival and proapoptotic pathways, such that unwanted apoptosis is avoided, but when required it occurs rapidly and efficiently. Many apoptosis regulators display dual roles, depending upon whether a cell has received an apoptotic stimulus or not. Here, we identify a novel and unexpected function for X-linked inhibitor of apoptosis (XIAP) that occurs when apoptosis is triggered under physiological conditions. We show that in response to loss of survival signals provided by cell adhesion, endogenous XIAP translocates from the cytosol into a mitochondrial 400-kDa complex and that this occurs very early in the apoptosis process. Membrane associated XIAP induces mitochondrial outer membrane permeabilization leading to cytochrome c and Smac release, which is dependent on Bax and Bak. Thus, although XIAP suppresses apoptosis in healthy cells, our data indicate that XIAP may contribute to it in response to a proapoptotic signal such as loss of extracellular matrix-dependent survival signaling. We suggest that, as with Bcl-2 family proteins, more diverse functions for XIAP exist than previously identified. Moreover, switching the function of proteins from anti- to proapoptotic forms may be a common theme in the efficient execution of cell death. PMID- 19875446 TI - Extracellular loops 2 and 4 of GLYT2 are required for N-arachidonylglycine inhibition of glycine transport. AB - Concentrations of extracellular glycine in the central nervous system are regulated by Na(+)/Cl(-)-dependent glycine transporters, GLYT1 and GLYT2. N Arachidonylglycine (NAGly) is an endogenous inhibitor of GLYT2 with little or no effect on GLYT1 and is analgesic in rat models of neuropathic and inflammatory pain. Understanding the molecular basis of NAGly interactions with GLYT2 may allow for the development of novel therapeutics. In this study, chimeric transporters were used to determine the structural basis for differences in NAGly sensitivity between GLYT1 and GLYT2 and also the actions of a series of related N arachidonyl amino acids. Extracellular loops 2 and 4 of GLYT2 are important in the selective inhibition of GLYT2 by NAGly and by the related compounds N arachidonyl-gamma-aminobutyric acid and N-arachidonyl-d-alanine, whereas only the extracellular loop 4 of GLYT2 is required for N-arachidonyl-l-alanine inhibition of transport. These observations suggest that the structure of the head group of these compounds is important in determining how they interact with extracellular loops 2 and 4 of GLYT2. Site-directed mutagenesis of GLYT2 EL4 residues was used to identify the key residues Arg(531), Lys(532), and Ile(545) that contribute to the differences in NAGly sensitivity. PMID- 19875447 TI - Structural characterization of the EphA4-Ephrin-B2 complex reveals new features enabling Eph-ephrin binding promiscuity. AB - EphA and EphB receptors preferentially bind ephrin-A and ephrin-B ligands, respectively, but EphA4 is exceptional for its ability to bind all ephrins. Here, we report the crystal structure of the EphA4 ligand-binding domain in complex with ephrin-B2, which represents the first structure of an EphA-ephrin-B interclass complex. A loose fit of the ephrin-B2 G-H loop in the EphA4 ligand binding channel is consistent with a relatively weak binding affinity. Additional surface contacts also exist between EphA4 residues Gln(12) and Glu(14) and ephrin B2. Mutation of Gln(12) and Glu(14) does not cause significant structural changes in EphA4 or changes in its affinity for ephrin-A ligands. However, the EphA4 mutant has approximately 10-fold reduced affinity for ephrin-B ligands, indicating that the surface contacts are critical for interclass but not intraclass ephrin binding. Thus, EphA4 uses different strategies to bind ephrin-A or ephrin-B ligands and achieve binding promiscuity. NMR characterization also suggests that the contacts of Gln(12) and Glu(14) with ephrin-B2 induce dynamic changes throughout the whole EphA4 ligand-binding domain. Our findings shed light on the distinctive features that enable the remarkable ligand binding promiscuity of EphA4 and suggest that diverse strategies are needed to effectively disrupt different Eph-ephrin complexes. PMID- 19875448 TI - Heme-binding protein HRG-1 is induced by insulin-like growth factor I and associates with the vacuolar H+-ATPase to control endosomal pH and receptor trafficking. AB - Endocytosis and trafficking of receptors and nutrient transporters are dependent on an acidic intra-endosomal pH that is maintained by the vacuolar H(+)-ATPase (V ATPase) proton pump. V-ATPase activity has also been associated with cancer invasiveness. Here, we report on a new V-ATPase-associated protein, which we identified in insulin-like growth factor I (IGF-I) receptor-transformed cells, and which was separately identified in Caenorhabditis elegans as HRG-1, a member of a family of heme-regulated genes. We found that HRG-1 is present in endosomes but not in lysosomes, and it is trafficked to the plasma membrane upon nutrient withdrawal in mammalian cells. Suppression of HRG-1 with small interfering RNA causes impaired endocytosis of transferrin receptor, decreased cell motility, and decreased viability of HeLa cells. HRG-1 interacts with the c subunit of the V ATPase and enhances V-ATPase activity in isolated yeast vacuoles. Endosomal acidity and V-ATPase assembly are decreased in cells with suppressed HRG-1, whereas transferrin receptor endocytosis is enhanced in cells that overexpress HRG-1. Cellular uptake of a fluorescent heme analogue is enhanced by HRG-1 in a V ATPase-dependent manner. Our findings indicate that HRG-1 regulates V-ATPase activity, which is essential for endosomal acidification, heme binding, and receptor trafficking in mammalian cells. Thus, HRG-1 may facilitate tumor growth and cancer progression. PMID- 19875449 TI - The acidic tail of the Cdc34 ubiquitin-conjugating enzyme functions in both binding to and catalysis with ubiquitin ligase SCFCdc4. AB - Ubiquitin ligases, together with their cognate ubiquitin-conjugating enzymes, are responsible for the ubiquitylation of proteins, a process that regulates a myriad of eukaryotic cellular functions. The first cullin-RING ligase discovered, yeast SCF(Cdc4), functions with the conjugating enzyme Cdc34 to regulate the cell cycle. Cdc34 orthologs are notable for their highly acidic C-terminal extension. Here we confirm that the Cdc34 acidic C-terminal tail has a role in Cdc34 binding to SCF(Cdc4) and makes a major contribution to the submicromolar K(m) of Cdc34 for SCF(Cdc4). Moreover, we demonstrate that a key functional property of the tail is its acidity. Our analysis also uncovers an unexpected new function for the acidic tail in promoting catalysis. We demonstrate that SCF is functional when Cdc34 is fused to the C terminus of Cul1 and that this fusion retains partial function even when the acidic tail has been deleted. The Cdc34-SCF fusion proteins that lack the acidic tail must interact in a fundamentally different manner than unfused SCF and wild type Cdc34, demonstrating that distinct mechanisms of E2 recruitment to E3, as is seen in nature, can sustain substrate ubiquitylation. Finally, a search of the yeast proteome uncovered scores of proteins containing highly acidic stretches of amino acids, hinting that electrostatic interactions may be a common mechanism for facilitating protein assembly. PMID- 19875450 TI - Cell-surface processing of the metalloprotease pro-ADAMTS9 is influenced by the chaperone GRP94/gp96. AB - A disintegrin-like and metalloprotease domain with thrombospondin type 1 motifs 9 (ADAMTS9) is a highly conserved metalloprotease that has been identified as a tumor suppressor gene and is required for normal mouse development. The secreted ADAMTS9 zymogen undergoes proteolytic excision of its N-terminal propeptide by the proprotein convertase furin. However, in contrast to other metalloproteases, propeptide excision occurs at the cell surface and leads to decreased activity of the zymogen. Here, we investigated the potential cellular mechanisms regulating ADAMTS9 biosynthesis and cell-surface processing by analysis of molecular complexes formed by a construct containing the propeptide and catalytic domain of pro-ADAMTS9 (Pro-Cat) in HEK293F cells. Cross-linking of cellular proteins bound to Pro-Cat followed by mass spectrometric analysis identified UDP glucose:glycoprotein glucosyltransferase I, heat shock protein gp96 (GRP94), BiP (GRP78), and ERdj3 (Hsp40 homolog) as associated proteins. gp96 and BiP were present at the cell surface in an immunoprecipitable complex with pro-ADAMTS9 and furin. Treatment with geldanamycin, an inhibitor of the HSP90alpha family (including gp96), led to decreased furin processing of pro-ADAMTS9 and accumulation of the unprocessed pro-ADAMTS9 at the cell surface. gp96 siRNA down regulated the levels of cell-surface pro-ADAMTS9 and furin, whereas the levels of cell-surface pro-ADAMTS9, but not of cell-surface furin, were decreased upon treatment with BiP siRNA. These data identify for the first time the cellular chaperones associated with secretion of an ADAMTS protease and suggest a role for gp96 in modulating pro-ADAMTS9 processing. PMID- 19875451 TI - A disintegrin and metalloproteinase 17 (ADAM17) mediates inflammation-induced shedding of syndecan-1 and -4 by lung epithelial cells. AB - Syndecans are cell surface proteoglycans that bind and modulate various proinflammatory mediators and can be proteolytically shed from the cell surface. Within the lung, syndecan-1 and -4 are expressed as transmembrane proteins on epithelial cells and released in the bronchoalveolar fluid during inflammation. We here characterize the mechanism leading to the generation of soluble syndecan 1 and -4 in cultured epithelial cells and murine lung tissue. We show that the bladder carcinoma epithelial cell line ECV304, the lung epithelial cell line A459 and primary alveolar epithelial cells express and constitutively release syndecan 1 and -4. This release involves the activity of the disintegrin-like metalloproteinase ADAM17 as demonstrated by use of specific inhibitors and lentivirally transduced shRNA. Stimulation of epithelial cells with PMA, thrombin, or proinflammatory cytokines (TNFalpha/IFNgamma) led to the down regulation of surface-expressed syndecan-1 and -4, which was associated with a significant increase of soluble syndecans and cell-associated cleavage fragments. The enhanced syndecan release was not related to gene induction of syndecans or ADAM17, but rather due to increased ADAM17 activity. Soluble syndecan-1 and -4 were also released into the bronchoalveolar fluid of mice. Treatment with TNFalpha/IFNgamma increased ADAM17 activity and syndecan release in murine lungs. Both constitutive and induced syndecan shedding was prevented by the ADAM17 inhibitor. ADAM17 may therefore be an important regulator of syndecan functions on inflamed lung epithelium. PMID- 19875452 TI - Cell adhesion molecule DdCAD-1 is imported into contractile vacuoles by membrane invagination in a Ca2+- and conformation-dependent manner. AB - The cadA gene in Dictyostelium encodes a Ca(2+)-dependent cell adhesion molecule DdCAD-1 that contains two beta-sandwich domains. DdCAD-1 is synthesized in the cytoplasm as a soluble protein and then transported by contractile vacuoles to the plasma membrane for surface presentation or secretion. DdCAD-1-green fluorescent protein (GFP) fusion protein was expressed in cadA-null cells for further investigation of this unconventional protein transport pathway. Both morphological and biochemical characterizations showed that DdCAD-1-GFP was imported into contractile vacuoles. Time-lapse microscopy of transfectants revealed the transient appearance of DdCAD-1-GFP-filled vesicular structures in the lumen of contractile vacuoles, suggesting that DdCAD-1 could be imported by invagination of contractile vacuole membrane. To assess the structural requirements in this transport process, the N-terminal and C-terminal domains of DdCAD-1 were expressed separately in cells as GFP fusion proteins. Both fusion proteins failed to enter the contractile vacuole, suggesting that the integrity of DdCAD-1 is required for import. Such a requirement was also observed in in vitro reconstitution assays using His(6)-tagged fusion proteins and purified contractile vacuoles. Import of DdCAD-1 was compromised when two of its three Ca(2+)-binding sites were mutated, indicating a role for Ca(2+) in the import process. Spectral analysis showed that mutations in the Ca(2+)-binding sites resulted in subtle conformational changes. Indeed, proteins with altered conformation failed to enter the contractile vacuole, suggesting that the import signal is somehow integrated in the three-dimensional structure of DdCAD-1. PMID- 19875453 TI - Transient receptor potential canonical type 1 (TRPC1) operates as a sarcoplasmic reticulum calcium leak channel in skeletal muscle. AB - Extensive studies performed in nonexcitable cells and expression systems have shown that type 1 transient receptor potential canonical (TRPC1) channels operate mainly in plasma membranes and open through phospholipase C-dependent processes, membrane stretch, or depletion of Ca(2+) stores. In skeletal muscle, it is proposed that TRPC1 channels are involved in plasmalemmal Ca(2+) influx and stimulated by store depletion or membrane stretch, but direct evidence for TRPC1 sarcolemmal channel activity is not available. We investigated here the functional role of TRPC1 using an overexpressing strategy in adult mouse muscle fibers. Immunostaining for endogenous TRPC1 revealed a striated expression pattern that matched sarcoplasmic reticulum (SR) Ca(2+) pump immunolabeling. In cells expressing TRPC1-yellow fluorescent protein (YFP), the same pattern of expression was observed, compatible with a longitudinal SR localization. Resting electric properties, action potentials, and resting divalent cation influx were not altered in TRPC1-YFP-positive cells. Poisoning with the SR Ca(2+) pump blocker cyclopiazonic acid elicited a contracture of the fiber at the level of the overexpression site in presence and absence of external Ca(2+) which was not observed in control cells. Ca(2+) measurements indicated that resting Ca(2+) and the rate of Ca(2+) increase induced by cyclopiazonic acid were higher in the TRPC1-YFP-positive zone than in the TRPC1-YFP-negative zone and control cells. Ca(2+) transients evoked by 200-ms voltage clamp pulses decayed slower in TRPC1 YFP-positive cells. In contrast to previous hypotheses, these data demonstrate that TRPC1 operates as a SR Ca(2+) leak channel in skeletal muscle. PMID- 19875454 TI - Lysosomal-mitochondrial axis in zoledronic acid-induced apoptosis in human follicular lymphoma cells. AB - Bisphosphonates (BPs) are potent inhibitors of osteoclast function, widely used to treat excessive bone resorption associated with bone metastases, that also have anti-tumor activity. Zoledronic acid (ZOL) represents a potential chemotherapeutic agent for the treatment of cancer. ZOL is the most potent nitrogen-containing BPs, and it inhibits cell growth and induces apoptosis in a variety of cancer cells. Recently we demonstrated that accumulation of isopentenyl pyrophosphate and the consequent formation of a new type of ATP analog (ApppI) after mevalonate pathway inhibition by nitrogen-containing BPs strongly correlates with ZOL-induced cell death in cancer cells in vitro. In this study we show that ZOL-induced apoptosis in HF28RA human follicular lymphoma cells occurs exclusively via the mitochondrial pathway, involves lysosomes, and is dependent on mevalonate pathway inhibition. To define the exact signaling pathway connecting them, we used modified HF28RA cell lines overexpressing either BclXL or dominant-negative caspase-9. In both mutant cells, mitochondrial and lysosomal membrane permeabilization (MMP and LMP) were totally prevented, indicating signaling between lysosomes and mitochondria and, additionally, an amplification loop for MMP and/or LMP regulated by caspase-9 in association with farnesyl pyrophosphate synthetase inhibition. Additionally, the lysosomal pathway in ZOL-induced apoptosis plays an additional/amplification role of the intrinsic pathway independently of caspase-3 activation. Moreover, we show a potential regulation by Bcl-XL and caspase-9 on cell cycle regulators of S-phase. Our findings provide a molecular basis for new strategies concomitantly targeting cell death pathways from multiple sites. PMID- 19875455 TI - Characterization of a carbon-carbon hydrolase from Mycobacterium tuberculosis involved in cholesterol metabolism. AB - In the recently identified cholesterol catabolic pathway of Mycobacterium tuberculosis, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (HsaD) is proposed to catalyze the hydrolysis of a carbon-carbon bond in 4,5-9,10-diseco-3 hydroxy-5,9,17-tri-oxoandrosta-1(10),2-diene-4-oic acid (DSHA), the cholesterol meta-cleavage product (MCP) and has been implicated in the intracellular survival of the pathogen. Herein, purified HsaD demonstrated 4-33 times higher specificity for DSHA (k(cat)/K(m) = 3.3 +/- 0.3 x 10(4) m(-1) s(-1)) than for the biphenyl MCP 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and the synthetic analogue 8-(2-chlorophenyl)-2-hydroxy-5-methyl-6-oxoocta-2,4-dienoic acid (HOPODA), respectively. The S114A variant of HsaD, in which the active site serine was substituted with alanine, was catalytically impaired and bound DSHA with a K(d) of 51 +/- 2 mum. The S114A.DSHA species absorbed maximally at 456 nm, 60 nm red-shifted versus the DSHA enolate. Crystal structures of the variant in complex with HOPDA, HOPODA, or DSHA to 1.8-1.9 Aindicate that this shift is due to the enzyme-induced strain of the enolate. These data indicate that the catalytic serine catalyzes tautomerization. A second role for this residue is suggested by a solvent molecule whose position in all structures is consistent with its activation by the serine for the nucleophilic attack of the substrate. Finally, the alpha-helical lid covering the active site displayed a ligand dependent conformational change involving differences in side chain carbon positions of up to 6.7 A, supporting a two-conformation enzymatic mechanism. Overall, these results provide novel insights into the determinants of specificity in a mycobacterial cholesterol-degrading enzyme as well as into the mechanism of MCP hydrolases. PMID- 19875456 TI - The phosphatidylinositol 3-kinase/Akt pathway regulates transforming growth factor-{beta} signaling by destabilizing ski and inducing Smad7. AB - Ski is an oncoprotein that negatively regulates transforming growth factor (TGF) beta signaling. It acts as a transcriptional co-repressor by binding to TGF-beta signaling molecules, Smads. Efficient TGF-beta signaling is facilitated by rapid proteasome-mediated degradation of Ski by TGF-beta. Here we report that Ski is phosphorylated by Akt/PKB kinase. Akt phosphorylates Ski on a highly conserved Akt motif at threonine 458 both in vitro and in vivo. The phosphorylation of Ski at threonine 458 is induced by Akt pathway activators including insulin, insulin like growth factor-1, and hepatocyte growth factor. The phosphorylation of Ski causes its destabilization and reduces Ski-mediated inhibition of expression of another negative regulator of TGF-beta, Smad7. Induction of Smad7 levels leads to inactivation of TGF-beta receptors and TGF-beta signaling cascade, as indicated by reduced induction of TGF-beta target p15. Therefore, Akt modulates TGF-beta signaling by temporarily adjusting the levels of two TGF-beta pathway negative regulators, Ski and Smad7. These novel findings demonstrate that Akt pathway activation directly impacts TGF-beta pathway. PMID- 19875457 TI - Src kinase-mediated phosphorylation stabilizes inducible nitric-oxide synthase in normal cells and cancer cells. AB - Src kinases are key regulators of cellular proliferation, survival, motility, and invasiveness. They play important roles in the regulation of inflammation and cancer. Overexpression or hyperactivity of c-Src has been implicated in the development of various types of cancer, including lung cancer. Src inhibition is currently being investigated as a potential therapy for non-small cell lung cancer in Phase I and II clinical trials. The mechanisms of Src implication in cancer and inflammation are linked to the ability of activated Src to phosphorylate multiple downstream targets that mediate its cellular effector functions. In this study, we reveal that inducible nitric-oxide synthase (iNOS), an enzyme also implicated in cancer and inflammation, is a downstream mediator of activated Src. We elucidate the molecular mechanisms of the association between Src and iNOS in models of inflammation induced by lipopolysaccharide and/or cytokines and in cancer cells and tissues. We identify human iNOS residue Tyr(1055) as a target for Src-mediated phosphorylation. These results are shown in normal cells and cancer cells as well as in vivo in mice. Importantly, such posttranslational modification serves to stabilize iNOS half-life. The data also demonstrate interactions and co-localization of iNOS and activated Src under inflammatory conditions and in cancer cells. This study demonstrates that phosphorylation of iNOS by Src plays an important role in the regulation of iNOS and nitric oxide production and hence could account for some Src-related roles in inflammation and cancer. PMID- 19875458 TI - Signal transducer and activator of transcription 3 (STAT3) mediates amino acid inhibition of insulin signaling through serine 727 phosphorylation. AB - Nutrient overload is associated with the development of obesity, insulin resistance, and type II diabetes. High plasma concentrations of amino acids have been found to correlate with insulin resistance. At the cellular level, excess amino acids impair insulin signaling, the mechanisms of which are not fully understood. Here, we report that STAT3 plays a key role in amino acid dampening of insulin signaling in hepatic cells. Excess amino acids inhibited insulin stimulated Akt phosphorylation and glycogen synthesis in mouse primary hepatocytes as well as in human hepatocarcinoma HepG2 cells. STAT3 knockdown protected insulin sensitivity from inhibition by amino acids. Amino acids stimulated the phosphorylation of STAT3 at Ser(727), but not Tyr(705). Replacement of the endogenous STAT3 with wild-type, but not S727A, recombinant STAT3 restored the ability of amino acids to inhibit insulin signaling, suggesting that Ser(727) phosphorylation was critical for STAT3-mediated amino acid effect. Furthermore, overexpression of STAT3-S727D was sufficient to inhibit insulin signaling in the absence of excess amino acids. Our results also indicated that mammalian target of rapamycin was likely responsible for the phosphorylation of STAT3 at Ser(727) in response to excess amino acids. Finally, we found that STAT3 activity and the expression of its target gene socs3, known to be involved in insulin resistance, were both stimulated by excess amino acids and inhibited by rapamycin. In conclusion, our study reveals STAT3 as a novel mediator of nutrient signals and identifies a Ser(727) phosphorylation-dependent and Tyr(705) phosphorylation-independent STAT3 activation mechanism in the modulation of insulin signaling. PMID- 19875459 TI - Neuronal insulin receptor substrate 2 (IRS2) expression is regulated by ZBP89 and SP1 binding to the IRS2 promoter. AB - Since neuronal insulin receptor substrate 2 (IRS2)-mediated signals coordinate key processes in rodent physiology such as food intake, fertility, longevity, and aging-related behavior, we analyzed the mechanisms of neuronal IRS2 expression in neuroblastoma (SHSY5Y) and hypothalamic (GT1-7) cell lines. Using dual luciferase reporter assays and IRS2 promoter deletion constructs, we identified a regulatory cassette within the IRS2 promoter between -779 and -679 bp from the translational start which is responsible for approximately 50% of neuronal IRS2 promoter activity. Chromatin immunoprecipitation assays and electromobility shift assay revealed four overlapping ZBP89/specificity protein 1 (SP1) binding sites which alternatively bind to ZBP89 (ZNF148 as listed in the HUGO Database) or SP1. Activation of this cassette is inhibited by phosphoinositide-3-kinase (PI3K) via increased ZBP89 binding to the promoter. Serum starvation caused increased SP1 binding at one specific SP1 site and decreased binding to another, proving a regulatory interaction between the different binding sites within this promoter cassette to tightly control IRS2 expression. Mutants containing all the possible combinations of one, two, three, or all the four SP1 binding sites of the IRS2 promoter revealed that SP1 binding to one particular site is most important for promoter activation. Stable downregulation of ZBP89 using siRNA substantially increased IRS2 mRNA and protein expression. Thus, alternative binding of ZBP89 or SP1 to the described region in the IRS2 promoter regulates neuronal IRS2 expression in a PI3K-dependent manner. PMID- 19875460 TI - Orthopedic surgeons and physical therapists differ in assessment of need for physical therapy after traumatic lower-extremity injury. AB - BACKGROUND: Lower-extremity injuries constitute the leading cause of trauma hospitalizations among people under the age of 65 years. Rehabilitation has the potential to favorably influence the outcomes associated with traumatic lower extremity injuries. OBJECTIVES: The objectives of this study were to explore variability in surgeon and physical therapist assessments of the need for physical therapy in patients with traumatic lower-extremity injuries and to determine the factors associated with assessments of need. DESIGN: This study was a retrospective cohort investigation. METHODS: Participants were 395 patients treated by reconstruction in the Lower-Extremity Assessment Project. They were evaluated at 8 level I trauma centers at 3, 6, and 12 months after hospitalization by an orthopedic surgeon and a physical therapist to determine the need for physical therapy. Analyses included multilevel logistic regression. RESULTS: Chi-square analyses showed that surgeon and therapist assessments of need differed statistically across trauma centers. Surgeons were more likely to assess a need for therapy at 3 months when participants had low work self efficacy, impaired knee flexion range of motion (ROM), and weight-bearing limitations and at 6 and 12 months when participants had impaired knee flexion ROM and weight-bearing and balance limitations. Therapists were more likely to assess a need for therapy at 3 months when participants had moderate to severe pain and at 6 and 12 months when participants had low work self-efficacy, pain, impaired knee flexion ROM, and balance limitations. CONCLUSIONS: The results revealed variability in assessments of the need for physical therapy at the provider and trauma center levels. Differences in provider assessments highlight the need for communication and further investigation into the outcomes and timing of physical therapy for the treatment of traumatic lower-extremity injuries. PMID- 19875461 TI - Testing the hierarchy of effects model: ParticipACTION's serial mass communication campaigns on physical activity in Canada. AB - The hierarchy of effects (HOE) model is often used in planning mass-reach communication campaigns to promote health, but has rarely been empirically tested. This paper examines Canada's 30 year ParticipACTION campaign to promote physical activity (PA). A cohort from the nationally representative 1981 Canada Fitness Survey was followed up in 1988 and 2002-2004. Modelling of these data tested whether the mechanisms of campaign effects followed the theoretical framework proposed in the HOE. Campaign awareness was measured in 1981. Outcome expectancy, attitudes, decision balance and future intention were asked in 1988. PA was assessed at all time points. Logistic regression was used to sequentially test mediating and moderating variables adjusting for age, sex and education. No selection bias was observed; however, relatively fewer respondents than non respondents smoked or were underweight at baseline. Among those inactive at baseline, campaign awareness predicted outcome expectancy which in turn predicted positive attitude to PA. Positive attitudes predicted high decision balance, which predicted future intention. Future intention mediated the relationship between decision balance and sufficient activity. Among those sufficiently active at baseline, awareness was unrelated to outcome expectancy and inversely related to positive attitude. These results lend support to the HOE model, in that the effects of ParticipACTION's serial mass media campaigns were consistent with the sequential rollout of its messages, which in turn was associated with achieving an active lifestyle among those initially insufficiently active. This provides support to an often-used theoretical framework for designing health promotion media campaigns. PMID- 19875462 TI - Socio-demographic predictors of health behaviors in Mexican college students. AB - Our objectives in this cross-sectional descriptive study were to analyze to what extent freshmen exhibit healthy behaviors, which socio-demographic variables predict healthy or unhealthy lifestyle, and what is the strength of the relationship. Three hundred seven Mexican University students were assessed. t Test and adjusted multiple regression analysis were computed. Life style was measured by use of the HPLP-II questionnaire and socio-demographics data. The results showed that most students presented a non-healthy lifestyle profile. Overall, the health behavior score was predicted by sex, mother's education and socio-economic level (R(2) = 0.104; p = 0.00001). When controlling for the other variables, nutrition was partially predicted by mother's education (R(2) = 0.048; p = 0.001); physical activity and stress management were modulated by sex, marital status and mother's education (R(2) = 0.111, p < 0.0001; R(2) = 0.096; p = 0.0001, respectively); interpersonal relations were predicted by mother's education and socio-economic level (R(2) = 0.104; p < 0.0001). These influences should be taken into account in designing interventions for specific socio demographic profiles that might be at higher risk for certain behaviors. PMID- 19875463 TI - Mitochondrial DNA background modifies the bioenergetics of NARP/MILS ATP6 mutant cells. AB - Mutations in the mitochondrial DNA (mtDNA) encoded subunit 6 of ATPase (ATP6) are associated with variable disease expression, ranging from adult onset neuropathy, ataxia and retinitis pigmentosa (NARP) to fatal childhood maternally inherited Leigh's syndrome (MILS). Phenotypical variations have largely been attributed to mtDNA heteroplasmy. However, there is often a discrepancy between the levels of mutant mtDNA and disease severity. Therefore, the correlation among genetic defect, bioenergetic impairment and clinical outcome in NARP/MILS remains to be elucidated. We investigated the bioenergetics of cybrids from five patients carrying different ATP6 mutations: three harboring the T8993G, one with the T8993C and one with the T9176G mutation. The bioenergetic defects varied dramatically, not only among different ATP6 mutants, but also among lines carrying the same T8993G mutation. Mutants with the most severe ATP synthesis impairment showed defective respiration and disassembly of respiratory chain complexes. This indicates that respiratory chain defects modulate the bioenergetic impairment in NARP/MILS cells. Sequencing of the entire mtDNA from the different mutant cell lines identified variations in structural genes, resulting in amino acid changes that destabilize the respiratory chain. Taken together, these results indicate that the mtDNA background plays an important role in modulating the biochemical defects and clinical outcome in NARP/MILS. PMID- 19875464 TI - Staging of laryngeal cancer using 64-channel multidetector row CT: comparison of standard neck CT with dedicated breath-maneuver laryngeal CT. AB - BACKGROUND AND PURPOSE: With a 64-channel multidetector row CT, imaging acquisition during speech, swallowing, or phonation has become feasible. However, the actual benefit of these additional focused images should be critically evaluated with respect to radiation dose. The purpose of this study was to determine if dedicated laryngeal CT using breath-holding and straw-blowing improved the accuracy of TNM-staging for patients with biopsy-proved laryngeal carcinomas in comparison with a standard neck CT. MATERIALS AND METHODS: A total of 27 patients underwent a standard neck CT and a laryngeal CT with additional images acquired while patients held their breath or blew through a straw. Two radiologists interpreted the neck CT and later the laryngeal CT and assigned a TNM-stage for each case. These interpretations were compared with a TNM-stage determined by surgery and/or clinical examination for the individual patients. The accuracy of standard neck CT was compared with the accuracy of laryngeal CT. RESULTS: The overall accuracy was not significantly different between standard neck CT and the additional laryngeal CT and was, in fact, lower in cases with additional larynx images. The accuracy of staging was slightly improved with the additional laryngeal CT for glottic cancers; however, it was decreased for supraglottic cancers. The accuracy of a dichotomous diagnosis of early-versus advanced-stage cancer was 0.86 for the standard neck CT and 0.80 for the laryngeal CT. The readers' confidence levels did not improve with the use of the additional images. CONCLUSIONS: In the era of isovoxel multidetector CT technology and judicious monitoring of radiation dose, a standard neck CT with coronal and sagittal reformats should suffice for the staging of laryngeal cancer. PMID- 19875465 TI - Identification of infarct core and penumbra in acute stroke using CT perfusion source images. AB - BACKGROUND AND PURPOSE: CT perfusion (CTP) mapping has been reported to be useful in the differentiation of the infarct core and ischemic penumbra. However, the value of the CTP source imaging (CTP-SI) during the arterial and venous phases has not been fully investigated. The purpose of this study was to develop a CTP SI methodology for acute ischemic stroke and compare its efficacy with cerebral blood flow (CBF) and cerebral blood volume (CBV) in predicting infarct core and penumbra. MATERIALS AND METHODS: CT examinations, including non-contrast-enhanced CT, CTP, and CT angiography (CTA), were performed in 42 patients with symptoms of stroke for <9 hours. The Alberta Stroke Program Early CT Score (ASPECTS) was analyzed on the arterial phase CTP-SI and venous phase CTP-SI and then compared with the ASPECTS on CBF and CBV for efficacy assessment. RESULTS: The ASPECTS on the arterial phase CTP-SI was closely correlated with the ASPECTS on CBF, the Pearson correlation coefficient was 0.88 (P < .001), and the concordance correlation coefficient was 0.7603 (95% confidence interval [CI], 0.6331-0.8476). The ASPECTS on the venous phase CTP-SI revealed a significant correlation with the ASPECTS on CBV, the Pearson correlation coefficient was 0.92 (P < .001), and the concordance correlation coefficient was 0.8880 (95% CI, 0.8148-0.9334). Significant differences were shown between the arterial phase CTP-SI/ venous phase CTP-SI (P < .001) and CBF/CBV (P < .001). CONCLUSIONS: This study provides preliminary evidence that the arterial phase and venous phase CTP-SI mismatch model could possibly be applied to ischemic regions in the acute stage of stroke to determine penumbra and infarct core. PMID- 19875466 TI - In vivo experimental intracranial aneurysm models: a systematic review. AB - Animal models are necessary to develop and test innovations in aneurysm therapy before clinical introduction. This review aims at identifying the most likely candidates for standardizing preclinical testing of aneurysm devices. We systematically searched electronic databases for publications on animal aneurysm models from 1961-2008 to assess the methodologic quality of the studies and collect data on the patency and angiographic and pathologic outcomes of treatments. There has been a steady increase in the annual number of publications with time. Species that were most frequently used were dogs, rabbits, and rodents, followed by swine. Most publications are single-laboratory studies with variables and poorly validated outcome measures, a small number of subjects, and limited standardization of techniques. The most appropriate models to test for recurrences after endovascular occlusion were the surgical bifurcation model in dogs, and the elastase-induced aneurysm model in rabbits. A standardized multicenter study is needed to improve the preclinical evaluation of endovascular devices in aneurysm therapy. PMID- 19875467 TI - Anatomic localization of dyskinesia in children with "profound" perinatal hypoxic ischemic injury. AB - BACKGROUND AND PURPOSE: CP is a common feature of perinatal HIBD in the context of "acute profound" injury, and in this article, we have studied the possible anatomic substrates of dyskinesia. We have reviewed the extent of brain injury in children with dyskinetic and spastic CP due to acute profound hypoxia to identify sites of injury that explain why only some children develop movement disorders. It is known that the STN has a role in the development of movement disorders; therefore, we have specifically studied it. MATERIALS AND METHODS: We retrospectively reviewed MR imaging of 40 consecutive children referred to our center with CP confirmed to be due to acute profound hypoxic-ischemic injury. All children received the same high-resolution MR imaging protocol with the same 1.5T scanner. Two pediatric neuroradiologists reviewed the imaging. Logistic regression was applied to identify multivariable predictors that differentiate dyskinetic and spastic CP. RESULTS: Twenty children had dyskinetic CP and 20 had spastic CP. Children with dyskinetic CP had more frequent injury to the STN, as manifest by increased T2 signal intensity. Children with spastic CP had more severe damage to white matter in the vicinity of the paracentral lobule. Injuries to the putamen, caudate, and globus pallidus were not significant predictors of dyskinesia. CONCLUSIONS: We have shown an association between hypoxic-ischemic injury to the STN at birth and the emergence of dyskinesia later in life. PMID- 19875468 TI - Hyperpolarized MR imaging: neurologic applications of hyperpolarized metabolism. AB - Hyperpolarization is the general term for a method of enhancing the spin polarization difference of populations of nuclei in a magnetic field. No less than 5 distinct techniques (dynamic nuclear polarization [DNP]; parahydrogen induced polarization-parahydrogen and synthesis allow dramatically enhanced nuclear alignment [PHIP-PASADENA]; xenon/helium polarization transfer; Brute Force; (1)H hyperpolarized water) are currently under exhaustive investigation as means of amplifying the intrinsically (a few parts per million) weak signal intensity used in conventional MR neuroimaging and spectroscopy. HD-MR imaging in vivo is a metabolic imaging tool causing much of the interest in HD-MR imaging. The most successful to date has been DNP, in which carbon-13 ((13)C) pyruvic acid has shown many. PHIP-PASADENA with (13)C succinate has shown HD-MR metabolism in vivo in tumor-bearing mice of several types, entering the Krebs-tricarboxylic acid cycle for ultrafast detection with (13)C MR imaging, MR spectroscopy, and chemical shift imaging. We will discuss 5 promising preclinical studies: (13)C succinate PHIP in brain tumor; (13)C ethylpyruvate DNP and (13)C acetate; DNP in rodent brain; (13)C succinate PHIP versus gadolinium imaging of stroke; and (1)H hyperpolarized imaging. Recent developments in clinical (13)C neurospectroscopy encourage us to overcome the remaining barriers to clinical HD-MR imaging. PMID- 19875469 TI - Nonenhancing intramedullary astrocytomas and other MR imaging features: a retrospective study and systematic review. AB - BACKGROUND AND PURPOSE: Most intramedullary astrocytomas have been known to exhibit at least some enhancement on MR imaging regardless of cell type or tumor grade. The purpose of this study was to evaluate the incidence of nonenhancing intramedullary astrocytomas through a retrospective study within our institutions and a systematic review of the medical literature. MATERIALS AND METHODS: A total of 19 consecutive patients (male to female ratio, 11:8; mean age, 27.84 +/- 19.0 years) with primary intramedullary astrocytomas (3 WHO grade I, 13 WHO grade II, 3 WHO grade III) who underwent preoperative MR imaging with contrast enhancement were included in this retrospective study from 4 institutions. The tumor enhancement patterns were classified into the following categories: 1) no enhancement, 2) focal nodular enhancement, 3) patchy enhancement, 4) inhomogeneous diffuse enhancement, and 5) homogeneous diffuse enhancement. Seven articles including MR imaging enhancement studies of intramedullary astrocytomas were eligible for literature review. RESULTS: In the retrospective study, 6 astrocytomas (32%), including 2 anaplastic astrocytomas, did not enhance at all. Focal nodular enhancement was identified in 5 astrocytomas (26%); patchy enhancement, in 3 (16%); inhomogeneous diffuse enhancement, in 5 (26%); and homogeneous diffuse enhancement, in none. In the literature review, the frequency of nonenhancing intramedullary astrocytomas was 14 of 76 (18%), including 2 anaplastic astrocytomas. CONCLUSIONS: Nonenhancing intramedullary astrocytomas are not uncommon and comprise between 20% and 30% of intramedullary astrocytomas. Therefore, astrocytoma must remain in the differential diagnosis of nonenhancing intramedullary lesions, particularly if the lesion demonstrates a prominent mass effect or cord expansion. PMID- 19875470 TI - Dynamic 320-section CT angiography in cranial arteriovenous shunting lesions. AB - Novel 320-section CT scanning equipment enables dynamic noninvasive angiographic imaging of the entire cranial vasculature (4D-CTA). We describe this technique and demonstrate its potential in arteriovenous shunting lesions. 4D-CTA imaging resulted in a correct diagnosis, lesion classification, and treatment-strategy selection in 3 patients, compared with CA. We think that 4D-CTA can further reduce the need for CA, sparing the patient the discomfort and risk associated with an invasive procedure. PMID- 19875471 TI - Perfusion CT in squamous cell carcinoma of the upper aerodigestive tract: long term predictive value of baseline perfusion CT measurements. AB - BACKGROUND AND PURPOSE: PCT studies hold short-term predictive value in patients treated with chemoradiotherapy. Our aim was to examine the long-term predictive value of baseline PCT studies for local tumor control and overall survival in SCCA of the upper aerodigestive tract treated with chemoradiotherapy. MATERIALS AND METHODS: Eighty-four patients with advanced SCCA underwent PCT followed by concomitant chemoradiation. The acquired perfusion maps represented BF, BV, MTT, and PS. Visual analysis of the parametric maps for identification of tumor perfusion patterns was conducted. ROC curves, t tests, and Kaplan-Meier survival curves were plotted for local disease control and overall survival. RESULTS: The median time of local tumor control was 24 months. The BF and PS values were significantly higher in patients who had no recurrence than in those with local failure (P < or = .02). The BF and PS were predictive (P < or = .0006) but BV and MTT held no significant predictive values for local tumor control. The patients with high BF and PS had a longer local tumor control than the patients with hypoperfused tumors (P = .0007). A visually detected BF-BV mismatch had a sensitivity/specificity of 63%/66% (P = .03) and 59%/69% (P = .03) for local tumor control and OS, respectively. Patients without mismatch lived significantly longer than patients with mismatch (P = .01). CONCLUSIONS: BF, PS, and mismatch of BF-BV are significant predictors of local tumor control after chemoradiation in SCCA of the upper aerodigestive tract. PMID- 19875472 TI - Diffusion MR imaging of hypoglycemic encephalopathy. AB - BACKGROUND AND PURPOSE: MR imaging features of HE have not been fully established. The purpose of this study was to determine the topographic distribution and DWI findings of HE. MATERIALS AND METHODS: We retrospectively evaluated HE MR imaging (n = 11). The topographic distribution of the lesions was evaluated on routine MR imaging, and DWI SI and ADC values were assessed. The ADC value of involved lesions was compared with the noninvolved subcortical WM area by use of the paired t test. RESULTS: MR images demonstrated bilateral diffusion restrictive lesions in the posterior limb of the IC (n = 6), cerebral cortex (n = 8), CR (n = 7), CS (n = 9), hippocampus (n = 4), and BG (n = 1). The mean ADC value of lesions was 448.82 +/- 92.34 x 10(-6) mm(2)/s compared with the mean ADC value of noninvolved lesions (837.72 +/- 62.14 x 10(-6) mm(2)/s); this difference was statistically significant (P < .000). The lesions showed complete resolution on follow-up DWI for 6 patients. Three patients with cortical involvement of > or = 2 lobes showed partial recovery or death, but most of the other patients with WM involvement or cortical involvement in only 1 lobe experienced complete recovery. CONCLUSIONS: The topographic localization of the lesions was the posterior limb of the IC, cerebral cortex, CR, CS, hippocampus, and BG. Most HE lesions probably correspond to areas of reversible cytotoxic edema as seen on DWI, which can predict the prognosis of HE according to the degree of lesion extent. PMID- 19875473 TI - Addictive illegal drugs: structural neuroimaging. AB - Illegal addictive drugs can lead to functional or structural impairment of the central nervous system. This review provides an overview of the structural imaging findings on CT, MR imaging, and conventional angiography related to chronic and acute abuse of the most commonly abused illegal drugs, including cannabis, organic solvents, and amphetamines and opioids and their respective derivatives. Pathomechanisms include excitotoxicity, which may lead to an acute or subacute leukoencephalopathy, and vascular complications, including vasoconstriction, vasculitis, or hypertension, which may lead to intracranial hemorrhage or ischemia. Because clinical findings alone are often nonspecific, and afflicted patients are unlikely to admit to the substance abuse, the neuroradiologist may play an important role in establishing the diagnosis and, thereby, initiating treatment. PMID- 19875474 TI - Fetal origin of the posterior cerebral artery produces left-right asymmetry on perfusion imaging. AB - BACKGROUND AND PURPOSE: Fetal origin of the PCA is a common anatomic variation of the circle of Willis. On perfusion imaging, patients with unilateral fetal-type PCA may demonstrate left-right asymmetry that could mimic cerebrovascular disease. The aim of this study was to characterize the relationship between a fetal-type PCA and asymmetry of hemodynamic parameters derived from MR perfusion imaging. MATERIALS AND METHODS: We retrospectively reviewed MR perfusion studies of 36 patients to determine the relationship between hemodynamic and vascular asymmetries in the PCA territory. Perfusion asymmetry indices for the PCA territory were computed from maps of rCBF, rCBV, MTT, T(max), and FMT. Vascular asymmetry indices were derived from calibers of the PCA-P1 segments relative to the posterior communicating arteries. RESULTS: Asymmetrically smaller values of FMT and T(max) were observed with unilateral fetal-type PCA, and these were strongly correlated with the degree of vascular asymmetry (Spearman's rho = 0.76 and 0.74, respectively, P < 1 x 10(-6)). Asymmetries of rCBF, MTT, and rCBV were neither significant nor related to vascular asymmetry. CONCLUSIONS: Faster perfusion transit times are seen for parameters sensitive to macrovascular transit effects (eg, FMT and T(max)) ipsilateral to fetal origin of the PCA in proportion to the degree of arterial asymmetry. Knowledge of this normal variation is critical in the interpretation of perfusion studies because asymmetry could mimic cerebrovascular pathology. PMID- 19875475 TI - Changes in perfusion CT of advanced squamous cell carcinoma of the head and neck treated during the course of concomitant chemoradiotherapy. AB - BACKGROUND AND PURPOSE: Concomitant chemoradiation is a promising therapy for the treatment of locoregionally advanced head and neck carcinoma. The purpose of this study was to prospectively evaluate early changes in primary tumor perfusion parameters during concomitant cisplatin-based chemoradiotherapy of locoregionally advanced SCCHN and to evaluate their predictive value for response of the primary tumor to therapy. MATERIALS AND METHODS: Twenty patients with locoregionally advanced SCCHN underwent perfusion CT scans before therapy and after completion of 40 Gy and 70 Gy of chemoradiotherapy. BF, BV, MTT, and PS of primary tumors were quantified. Differences in perfusion and tumor volume values during the therapy as well as between responders and nonresponders were analyzed, and ROC curves were used to assess predictive value of the baseline and follow-up functional parameters. RESULTS: The tumor volumes at 40 Gy and at 70 Gy were significantly lower compared with baseline values (P = .014 and P = .007). In the 6 nonresponders, measurements after 40 Gy showed a nonsignificant trend of increased BF, BV, and PS values compared with the baseline values (P = .06). In 14 responders, a significant reduction of BF values was recorded after 40 Gy (P = .04) and after 70 Gy (P = .01). In responders, BV values showed a reduction after 40 Gy followed by a plateau after 70 Gy (P = .04), whereas in nonresponders there was a nonsignificant elevation of the BV. Baseline BV predicted short-term tumor response with a sensitivity of 60% and specificity of 100% (P = .01). After completion of 40 Gy of concomitant chemoradiation BV was a more significant predictor than were BF and MTT. CONCLUSIONS: The results suggest that in advanced SCCHN the perfusion CT monitoring might be of predictive value for identifying tumors that may respond to cisplatin-based chemoradiotherapy. PMID- 19875476 TI - Concomitant suppression of three target genes can explain the impact of a microRNA on metastasis. AB - It remains unclear whether a microRNA (miRNA) affects a given phenotype via concomitant down-regulation of its entire repertoire of targets or instead by suppression of only a modest subset of effectors. We demonstrate that inhibition of breast cancer metastasis by miR-31-a miRNA predicted to modulate >200 mRNAs can be entirely explained by miR-31's pleiotropic regulation of three targets. Thus, concurrent re-expression of integrin-alpha5, radixin, and RhoA abrogates miR-31-imposed metastasis suppression. These effectors influence distinct steps of the metastatic process. Our findings have implications concerning the importance of pleiotropy for the biological actions of miRNAs and provide mechanistic insights into metastasis. PMID- 19875477 TI - Effect of rosiglitazone, metformin, and glyburide on bone biomarkers in patients with type 2 diabetes. AB - CONTEXT: An increase in bone fractures has been observed in women taking thiazolidinediones. OBJECTIVE: The objective of the study was to examine whether changes in circulating bone biomarkers provide insight into the underlying mechanisms responsible for the increase in bone fractures in female participants randomized to rosiglitazone in A Diabetes Outcome Progression Trial (ADOPT). RESEARCH DESIGN AND METHODS: Paired stored baseline and 12-month serum samples were available from 1605 participants (689 women, 916 men) in ADOPT, a long-term clinical trial comparing the effects of rosiglitazone, glyburide, and metformin on glycemic control in patients with type 2 diabetes. RESULTS: This subset was well matched to the total ADOPT study population. In women a marker of osteoclast activity, C-terminal telopeptide (for type 1 collagen), increased by 6.1% with rosiglitazone compared with reductions of 1.3% (P = 0.03 vs. rosiglitazone) and 3.3% (P = 0.002 vs. rosiglitazone) with metformin and glyburide, respectively. In men, C-terminal telopeptide was unchanged on rosiglitazone (-1.0%) and fell on metformin (-12.7%; P < 0.001) and glyburide (-4.3%, P = NS). Markers of osteoblast activity, procollagen type 1 N-propeptide (P1NP) and bone alkaline phosphatase, were reduced for women and men in almost all treatment groups, with the greatest changes in the metformin group (P1NP in females, -14.4%; P1NP in males, -19.3%), intermediate for rosiglitazone (P1NP in females, -4.4%; P1NP in males, -14.4%), and smallest for glyburide (P1NP in males, +0.2%; bone alkaline phosphatase in females, -11.6%). CONCLUSIONS: Commonly measured bone biomarkers suggest that changes in bone resorption may be partly responsible for the increased risk of fracture in women taking thiazolidinediones. PMID- 19875478 TI - Atypical progeroid syndrome due to heterozygous missense LMNA mutations. AB - CONTEXT: Hutchinson-Gilford progeria syndrome (HGPS) and mandibuloacral dysplasia are well-recognized allelic autosomal dominant and recessive progeroid disorders, respectively, due to mutations in lamin A/C (LMNA) gene. Heterozygous LMNA mutations have also been reported in a small number of patients with a less well characterized atypical progeroid syndrome (APS). OBJECTIVE: The objective of the study was to investigate the underlying genetic and molecular basis of the phenotype of patients presenting with APS. RESULTS: We report 11 patients with APS from nine families, many with novel heterozygous missense LMNA mutations, such as, P4R, E111K, D136H, E159K, and C588R. These and previously reported patients now reveal a spectrum of clinical features including progeroid manifestations such as short stature, beaked nose, premature graying, partial alopecia, high-pitched voice, skin atrophy over the hands and feet, partial and generalized lipodystrophy with metabolic complications, and skeletal anomalies such as mandibular hypoplasia and mild acroosteolysis. Skin fibroblasts from these patients when assessed for lamin A/C expression using epifluorescence microscopy revealed variable nuclear morphological abnormalities similar to those observed in patients with HGPS. However, these nuclear abnormalities in APS patients could not be rescued with 48 h treatment with farnesyl transferase inhibitors, geranylgeranyl transferase inhibitors or trichostatin-A, a histone deacetylase inhibitor. Immunoblots of cell lysates from fibroblasts did not reveal prelamin A accumulation in any of these patients. CONCLUSIONS: APS patients have a few overlapping but some distinct clinical features as compared with HGPS and mandibuloacral dysplasia. The pathogenesis of clinical manifestations in APS patients seems not to be related to accumulation of mutant farnesylated prelamin A. PMID- 19875479 TI - Tumor infiltrating lymphocytes but not serum pituitary antibodies are associated with poor clinical outcome after surgery in patients with pituitary adenoma. AB - CONTEXT: Serum pituitary antibodies (Pit Abs) and tumor-infiltrating lymphocytes (TILs) have been described in pituitary adenomas, but their clinical significance remains unknown. OBJECTIVE: The objective of the study was to assess Pit Abs and TILs prevalence in pituitary adenomas and their influence on clinical outcome. DESIGN: This was a prevalence case-control study. PATIENTS AND SETTING: Two hundred ninety-one pituitary adenoma cases (110 non-secreting, 30 ACTH-69 GH-71 prolactin- and 13 TSH-secreting adenoma; 177 operated and 114 untreated), 409 healthy controls, and 14 autoimmune hypophysitis were enrolled in a tertiary referral center. INTERVENTION: Pit Abs were measured using immunofluorescence in all cases and controls (n = 714). The presence of TILs was evaluated using CD45 staining in a subset of adenomas surgically treated (n = 72). MAIN OUTCOME MEASURE: Clinical response of pituitary adenoma after surgery was evaluated. RESULTS: Pit Abs prevalence was higher in adenomas (5.1%) than healthy subjects (0.7%, P < 0.0001) and lower than in autoimmune hypophysitis patients (57%, P < 0.0001). Similarly, TILs prevalence was higher in adenomas than normal pituitary (P = 0.01) and lower than in autoimmune hypophysitis (P < 0.0001). No correlation between Pit Abs and TILs was found (P = 0.78). A poor clinical outcome was more common in adenoma patients with TILs (11 of 18, 61%) than in those without (17 of 54, 31%, P = 0.026). Multivariate regression analysis identified the presence of TILs as independent prognostic factor for persistence/recurrence of pituitary adenoma. CONCLUSIONS: TILs and Pit Abs are present in a significant number of pituitary adenoma patients. Cell-mediated immunity appears to be predictive of a less favorable clinical outcome. PMID- 19875480 TI - Clinical applications of diabetes antibody testing. AB - CONTEXT: Autoantibodies to glutamate decarboxylase, islet antigen-2, insulin, and zinc transporter-8 are characteristic of type 1 diabetes. They are detectable before clinical onset and define the subgroup of patients with latent autoimmune diabetes in adults. Autoantibody assays are increasingly available to clinicians. This article reviews the prognostic significance of autoantibodies and considers the utility of diabetes antibody testing in routine clinical practice. EVIDENCE ACQUISITION: The medical literature to May 2009 was reviewed for key articles and consensus statements covering use of islet autoantibody testing for prediction and classification of diabetes and implications for therapy. EVIDENCE SYNTHESIS: Sensitive and specific glutamate decarboxylase and islet antigen-2 antibody assays are widely available, although to insulin autoantibody assays remain variable. Islet autoantibodies appear early in life, and testing for multiple antibodies identifies unaffected individuals at very high risk of type 1 diabetes with high sensitivity. This is important for research, but currently no intervention prevents or delays diabetes, and evidence of benefit from awareness of risk is weak. In non-insulin-treated diabetes, patients with autoantibodies progress to insulin requirement more rapidly, but evidence that testing benefits the individual patient is limited. Antibody testing is useful in classifying diabetes of other types. CONCLUSIONS: Islet autoantibody testing allows prediction of type 1 diabetes and definition of the latent autoimmune diabetes in adults subgroup of non-insulin-treated patients. Although useful for research, until therapies modulating the disease process become available, the benefit to individual patients is generally questionable. With a few exceptions, diabetes antibody testing does not yet have a role in routine clinical care. PMID- 19875482 TI - Detection of growth hormone doping by gene expression profiling of peripheral blood. AB - CONTEXT: GH abuse is a significant problem in many sports, and there is currently no robust test that allows detection of doping beyond a short window after administration. OBJECTIVE: Our objective was to evaluate gene expression profiling in peripheral blood leukocytes in-vivo as a test for GH doping in humans. DESIGN: Seven men and thirteen women were administered GH, 2 mg/d sc for 8 wk. Blood was collected at baseline and at 8 wk. RNA was extracted from the white cell fraction. Microarray analysis was undertaken using Agilent 44K G4112F arrays using a two-color design. Quantitative RT-PCR using TaqMan gene expression assays was performed for validation of selected differentially expressed genes. RESULTS: GH induced an approximately 2-fold increase in circulating IGF-I that was maintained throughout the 8 wk of the study. GH induced significant changes in gene expression with 353 in women and 41 in men detected with a false discovery rate of less than 5%. None of the differentially expressed genes were common between men and women. The maximal changes were a doubling for up regulated or halving for down-regulated genes, similar in magnitude to the variation between individuals. Quantitative RT-PCR for seven target genes showed good concordance between microarray and quantitative PCR data in women but not in men. CONCLUSION: Gene expression analysis of peripheral blood leukocytes is unlikely to be a viable approach for the detection of GH doping. PMID- 19875481 TI - Dissociation between skeletal muscle inhibitor-kappaB kinase/nuclear factor kappaB pathway activity and insulin sensitivity in nondiabetic twins. AB - CONTEXT: Several studies suggest a link between increased activity of the inflammatory inhibitor-kappaB kinase/nuclear factor-kappaB (IKK/NF-kappaB) pathway in skeletal muscle and insulin resistance. OBJECTIVE: We aimed to study the regulation of skeletal muscle IKK/NF-kappaB pathway activity as well as the association with glucose metabolism and skeletal muscle insulin signaling. METHODS: The study population included a metabolically well-characterized cohort of young and elderly predominantly nondiabetic twins (n = 181). Inhibitor kappaBbeta (IkappaBbeta) protein levels are negatively associated with IKK/NF kappaB pathway activity and were used to evaluate pathway activity with p65 levels included as loading control. This indirect measure for IKK/NF-kappaB pathway activity was validated by a p65 binding assay. RESULTS: Evaluating the effects of heritability, age, sex, obesity, aerobic capacity, and several hormonal factors (eg insulin and TNF-alpha), only sex and age were significant predictors of IkappaBbeta to p65 ratio (28% decreased ratio in the elderly, P < 0.01, and 49% increased in males P < 0.01). IkappaBbeta to p65 ratio was unrelated to peripheral insulin sensitivity (P = 0.51) and in accordance with this also unrelated to proximal insulin signaling (P = 0.81). Although no association was seen with plasma glucose after oral glucose challenge, there was a tendency for lower IkappaBbeta to p65 ratio (adjusted for age and sex) in subjects with impaired as opposed to normal glucose tolerance (P = 0.055). CONCLUSIONS: Altogether the subtle elevated IKK/NF-kappaB pathway activity seen in glucose-intolerant subjects suggests that IKK/NF-kappaB pathway activation may be secondary to impaired glucose tolerance and that skeletal muscle IKK/NF-kappaB pathway activity is unlikely to play any major role in the control of skeletal muscle insulin action in nondiabetic subjects. PMID- 19875483 TI - Eating slowly increases the postprandial response of the anorexigenic gut hormones, peptide YY and glucagon-like peptide-1. AB - CONTEXT: The rate at which people eat has been suggested to be positively associated with obesity, although appetite and related gut hormones have not been measured. The objective of the study was to determine whether eating the same meal at varying speeds elicits different postprandial gut peptide responses. DESIGN AND SETTING: This was a crossover study at a clinical research facility. STUDY PARTICIPANTS: Seventeen healthy adult male volunteers participated in the study. INTERVENTION: A test meal consisting of 300 ml ice cream (675 kcal) was consumed in random order on two different sessions by each subject: meal duration took either 5 or 30 min. MAIN OUTCOME MEASURES: The postprandial response of the orexigenic hormone ghrelin and the anorexigenic peptides peptide YY and glucagon like peptide-1 over 210 min was assessed. Visual analog scales for the subjective feelings of hunger and fullness were completed throughout each session. RESULTS: Peptide YY area under the curve (AUC) was higher after the 30-min meal than after the 5-min meal (mean +/- sem AUC 5 min meal: 4133 +/- 324, AUC 30 min meal: 5250 +/- 330 pmol/liter . min, P = 0.004), as was glucagon-like peptide-1 AUC (mean +/ sem AUC 5 min meal: 6219 +/- 256, AUC 30 min meal: 8794 +/- 656 pmol/liter . min, P = 0.001). There was a trend for higher visual analog scale fullness ratings immediately after the end of the 30-min meal compared with immediately after the 5-min meal. There were no differences in ghrelin response. CONCLUSIONS: Eating at a physiologically moderate pace leads to a more pronounced anorexigenic gut peptide response than eating very fast. PMID- 19875484 TI - Maternal serum angiopoietin-1 and -2 and tie-2 in early pregnancy ending in preeclampsia or intrauterine growth retardation. AB - CONTEXT: The antiangiogenic growth factor angiopoietin-2 (Ang-2) antagonizes, whereas angiopoietin-1 (Ang-1) activates the endothelial cell-specific tyrosine kinase receptor-2 (Tie-2). In preeclampsia, circulating concentrations of Ang-1 are increased and those of Ang-2 and Tie-2 are decreased. OBJECTIVE: We wanted to study whether maternal serum concentrations of Ang-1, Ang-2, and Tie-2 are altered at gestational wk 12-15 or 16-20 in women with subsequent preeclampsia or intrauterine growth retardation (IUGR). DESIGN: This was a case-control study. SETTING: The study was conducted in Helsinki University Central Hospital, a tertiary referral center. PATIENTS: This study comprised 124 pregnant women, of whom 49 developed preeclampsia and 16 gave birth to infants with IUGR, and 59 healthy women served as controls. MAIN OUTCOME MEASURES: Serum concentrations of Ang-1, Ang-2, and Tie-2 were assessed by ELISA. Data were combined with our earlier data on soluble VEGF receptor (sVEGFR)-1. RESULTS: At gestational wk 12 15, the median concentrations of Ang-1, Ang-2, or Tie-2 were all similar between the study groups. At 16-20 wk, Ang-2 concentrations were higher in women with subsequent preeclampsia [25.0 ng/ml, 19.3-39.5 ng/ml; median, interquartile range (IQR)] than in the controls (17.7 ng/ml, 10.8-27.4 ng/ml, P = 0.006). The odds ratio of high Ang-2 concentrations for subsequent preeclampsia was 4.2 (95% confidence interval 1.4-12.6; P = 0.011) and high Ang-2 combined with high sVEGFR 1, 6.4 (95% confidence interval 2.2-18.7; P = 0.001). CONCLUSION: Maternal serum Ang-2 concentrations are increased prior to preeclampsia. High concentrations of both Ang-2 and sVEGFR-1 indicate subsequent disease. PMID- 19875485 TI - The glucocorticoid-induced leucine zipper gene (GILZ) expression decreases after successful treatment of patients with endogenous Cushing's syndrome and may play a role in glucocorticoid-induced osteoporosis. AB - CONTEXT: Glucocorticoid-induced bone loss is a serious complication in patients with endogenous Cushing's syndrome. However, the mechanism(s) by which excess glucocorticoids influence bone metabolism is not completely understood. OBJECTIVE: The aim of the study was to investigate the functional role of glucocorticoid-induced leucine zipper (GILZ) in bone remodeling with special focus on glucocorticoid-induced osteoporosis (GIO). PATIENTS: Nine patients with endogenous Cushing's syndrome participated in the study. RESEARCH DESIGN AND METHODS: We analyzed bone biopsies from Cushing's patients before and after treatment to screen for expressional candidate genes with putative roles in GIO. Microarray analysis combined with real-time RT-PCR revealed that the gene encoding GILZ ranked among the topmost regulated genes and was selected for functional characterization in vitro. RESULTS: GILZ mRNA was expressed by human fetal osteoblasts (hFOB), human mesenchymal stem cells (hMSC), osteoblasts differentiated from hMSC, and osteoclasts. GILZ was increased by dexamethasone in a time- and dose-dependent manner in hFOB. Inhibition of GILZ in hFOB cells by small interfering RNA decreased typical osteoblast-related genes, suggesting a physiological role in promoting osteoblast maturation. Our data further support a functional role for GILZ in normal bone remodeling by modulating expression of TNF-(ligand) receptor superfamily/osteoprotegerin in favor of increased ratio in hFOB. Finally, osteoclasts exposed to conditioned media from GILZ-silenced hFOB indicated effects on osteoclast activity. CONCLUSION: Taken together, these results implicate the transcription factor GILZ in the pathophysiology of GIO by regulating osteoblast maturation and bone turnover. PMID- 19875486 TI - Introductory overview to the proceedings of the XXth North American Testis Workshop. PMID- 19875487 TI - LDHC: the ultimate testis-specific gene. AB - Lactate dehydrogenase C (LDHC) was, to the best of our knowledge, the first testis-specific isozyme discovered in male germ cells. In fact, this was accomplished shortly before "isozymes or isoenzymes" became a field of study. LDHC was detected initially in human spermatozoa and spermatogenic cells of the testes by gel electrophoresis. Immunohistochemistry was used to localize LDHC first in early-pachytene primary spermatocytes, with an apparent increase in quantity after meiosis, to its final localization in and on the principal piece of the sperm tail. After several decades of biologic, biochemical, and genetic investigations, we now know that the lactate dehydrogenase isozymes are ubiquitous in vertebrates, developmentally regulated, tissue and cell specific, and multifunctional. Here, we will review the history of LDHC and the work that demonstrates clearly that it is required for sperm to accomplish their ultimate goal, fertilization. PMID- 19875488 TI - The power of mouse genetics to study spermatogenesis. AB - Approximately 80 million people worldwide are infertile, and nearly half of all infertility cases are attributed to a male factor. Therefore, progress in reproductive genetics becomes crucial for future diagnosis and treatment of infertility. In recent years, enormous progress has been made in this field. More than 400 mutant mouse models with specific reproductive abnormalities have been produced, and numerous human association studies have been discovered. However, the translation of basic science findings to clinical practice remains protracted, with only modest progress in the application of novel findings to clinical genetic testing and cures. To date, the most significant findings in male infertility remain numeric and structural chromosomal abnormalities and Y chromosome microdeletions in infertile men. Thus, we anticipate that future genetic investigations will focus on infertile men with a normal somatic karyotype but with various spermatozoal defects, like insufficient production of spermatozoa (oligozoospermia), inadequate motility (asthenozoospermia), abnormal morphology (teratozoospermia), or combinations of these defects. Ultimately, basic advances in mammalian nonhuman reproduction will translate to clinical advances in human reproduction and testing for infertile humans, thereby helping to improve diagnostics and health care for infertile patients. PMID- 19875489 TI - Fetal Leydig cells: progenitor cell maintenance and differentiation. AB - In most eutherian mammals, sexually dimorphic masculinization is established by androgen-producing fetal Leydig cells in the embryonic testis. Fetal Leydig cells, which lack expression of the testis-determining gene SRY, arise after the appearance of SRY-expressing Sertoli cells. Therefore, the appearance and differentiation of fetal Leydig cells are probably regulated by factors derived from Sertoli cells. Results from mouse genetic models have revealed that maintenance and differentiation of fetal Leydig cell population depends upon a balance between differentiation-promoting and differentiation-suppressing mechanisms. Although paracrine signaling via Sertoli cell-derived Hedgehog ligands is necessary and sufficient for fetal Leydig cell formation, cell-cell interaction via Notch signaling and intracellular transcription factors such as POD1 are implicated as suppressors of fetal Leydig cell differentiation. This review provides a model that summarizes the recent findings in fetal Leydig cell development. PMID- 19875490 TI - P granule assembly and function in Caenorhabditis elegans germ cells. AB - Germ granules are large, non-membrane-bound, ribonucleoprotein (RNP) organelles found in the germ line cytoplasm of most, if not all, animals. The term germ granule is synonymous with the perinuclear nuage in mouse and human germ cells. These large RNPs are complexed with germ line-specific cytoplasmic structures such as the mitochondrial cloud, intermitochondrial cement, and chromatoid bodies. The widespread presence of germ granules across species and the associated germ line defects when germ granules are compromised suggest that germ granules are key determinants of the identity and special properties of germ cells. The nematode Caenorhabditis elegans has been a very fruitful model system for the study of germ granules, wherein they are referred to as P granules. P granules contain a heterogeneous mixture of RNAs and proteins. To date, most of the known germ granule proteins across species, and all of the known P granule components in C elegans, are associated with RNA metabolism, which suggests that a main function of germ granules is posttranscriptional regulation. Here we review P granule structure and localization, P granule composition, the genetic pathway of P granule assembly, and the consequences in the germ line when P granule components are lost. The findings in C elegans have important implications for the germ granule function during postnatal germ cell differentiation in mammals. PMID- 19875491 TI - Illuminating testis morphogenesis in the mouse. AB - The mammalian testis is a complex organ composed of multiple cell types that are organized into seminiferous tubules and an interstitium, producing spermatozoa and hormones, respectively. During embryogenesis, the testis forms from the genital ridge associated with the embryonic kidney called the mesonephros. After germ cells migrate into the genital ridge, the Sertoli cell-germ cell mass forms and undergoes morphogenetic changes to generate testis cords, the precursors of the seminiferous tubules. Static images of the fetal testis at sequential stages of development provide structural information about cord formation. Transgenic mice that express fluorescent protein reporters offer new opportunities for time lapse imaging to visualize live cells and their behaviors during testis differentiation and morphogenesis. PMID- 19875492 TI - Gonadotropin-regulated testicular RNA helicase (GRTH/DDX25): a multifunctional protein essential for spermatogenesis. AB - Male germ cell maturation is governed by the expression of specific protein(s) in a precise temporal sequence during development. Gonadotropin-regulated testicular RNA helicase (GRTH/DDX25), a member of the Glu-Asp-Ala-Glu (DEAD)-box protein family, is a testis-specific gonadotropin/androgen-regulated RNA helicase that is present in germ cells (meiotic spermatocytes and round spermatids) and Leydig cells. GRTH is essential for completion of spermatogenesis as a posttranscriptional regulator of relevant genes during germ cell development. Male mice lacking GRTH are sterile with spermatogenic arrest due to failure of round spermatids to elongate, where striking structural changes and reduction in size of chromatoid bodies are observed. GRTH also plays a central role in preventing germ cell apoptosis. In addition to its inherent helicase unwinding/adenosine triphosphatase activities, GRTH binds to specific mRNAs as an integral component of ribonuclear protein particles. As a shuttle protein, GRTH transports target mRNAs from nucleus to the cytoplasm for storage in chromatoid bodies of spermatids, where they await translation during spermatogenesis. GRTH is also associated with polyribosomes to regulate target gene translation. The finding of a missense mutation associated with male infertility, where its expression associates with loss of GRTH phosphorylation, supports the relevance of GRTH to human germ cell development. We conclude that the mammalian GRTH/DDX25 is a multifunctional RNA helicase that is an essential regulator of spermatogenesis and is highly relevant for studies of male infertility and contraception. PMID- 19875493 TI - Determination and stability of gonadal sex. AB - The discovery that the SRY gene induces male sex in humans and other mammals led to speculation about a possible equivalent for female sex. But females are proving to be more complicated. Several master genes appear to be autonomously involved, and female sex determination seems to remain relatively labile. Partial loss of function of the transcription factor FOXL2 leads to premature ovarian failure in women; and in animal models, Foxl2 is required for folliculogenesis as well as for maintenance, and possibly induction, of female sex determination. In the germ line, oocytes apparently form normally even in the absence of Foxl2, dependent on genes that include female-specific factors such as Fig-alpha, Nobox, etc. In the soma, ablation of Foxl2 or the independently expressed gene Wnt4 (likely downstream of Rspo1) can produce partial testis differentiation in XX mice, and the double knockout results in the formation of tubules and spermatogonia. This indicates that at least 2 autonomous ovarian pathways are required to antagonize testis differentiation in females, a finding that is being increasingly corroborated by studies in goats and nonmammalian vertebrates. In recent expression profiling of mouse ovaries that lack Foxl2 alone or in combination with Wnt4 or Kit/c-Kit, we found that following Foxl2 loss, early testis genes (including the downstream effector of Sry, Sox9) and several novel ovarian genes were consistently dysregulated during embryo-fetal development. The results support the proposal of dose-dependent Foxl2 function and antitestis action. A partial working model for somatic development and sex determination is presented in which Sox9 is a direct antagonist of Foxl2 in the supporting cell lineage. PMID- 19875494 TI - Regulation of male fertility by X-linked genes. AB - Infertility is a worldwide reproductive health problem, affecting men and women about equally. Mouse genetic studies demonstrate that more than 200 genes specifically or predominantly regulate fertility. However, few genetic causes of infertility in humans have been identified. Here, we focus on the regulation of male fertility by X-linked, germ cell-specific genes. Previous genomic studies reveal that the mammalian X chromosome is enriched for genes expressed in early spermatogenesis. Recent genetic studies in mice show that X-linked, germ cell specific genes, such as A-kinase anchor protein 4 (Akap4), nuclear RNA export factor 2 (Nxf2), TBP-associated factor 7l (Taf7l), and testis-expressed gene 11 (Tex11), indeed play important roles in the regulation of male fertility. Moreover, we find that the Taf7l Tex11 double-mutant males exhibit much more severe defects in meiosis than either single mutant, suggesting that these 2 X linked genes regulate male meiosis synergistically. The X-linked, germ cell specific genes are particularly attractive in the study of male infertility in humans. Because males are hemizygous for X-linked genes, loss-of-function mutations in the single-copy X-linked genes, unlike in autosomal genes, would not be masked by a normal allele. The genetic studies of X-linked, germ cell-specific genes in mice have laid a foundation for mutational analysis of their human orthologues in infertile men. PMID- 19875495 TI - Sam68: a new STAR in the male fertility firmament. AB - Male infertility accounts for approximately 50% of the cases of sterile human couples, and in many instances the genetic or molecular defects involved remain unknown. Studies conducted in animal models have elucidated the key role played by RNA-binding proteins and by the posttranscriptional regulation of gene expression during spermatogenesis. Ablation of proteins involved in each of the steps required for the processing and the utilization of messenger RNAs impairs the production of fertile spermatozoa. Recent evidence indicates that the RNA binding protein Sam68 is absolutely required for the correct progression of spermatogenesis and for male fertility in the mouse. Sam68 belongs to the evolutionary conserved signal transduction and activation of RNA (STAR) family of RNA-binding proteins. The members of this family have been demonstrated to play crucial roles in cell differentiation and development, including male and female gametogenesis. In this review we will summarize the observations gathered on the functions of STAR proteins in different organisms, with particular emphasis on the role of Sam68 in male fertility. PMID- 19875496 TI - microRNAs in the testis: building up male fertility. AB - Spermatogenesis is a strictly regulated process, at both the transcriptional and the posttranscriptional level, which allows continuous gamete production throughout adulthood. A novel mechanism of posttranscriptional control mediated by microRNAs (miRNAs) has lately emerged as an important regulator of spermatogenesis. miRNAs are endogenous, small, noncoding RNAs produced through a multistep enzymatic process, which involves the action of Dicer, an RNaseIII endonuclease. Here, we first present a short overview of classic posttranscriptional control during spermatogenesis, and then concentrate on recent findings that have unraveled the important role of miRNAs in male reproductive function. Particular focus is given to the in vivo role of miRNAs that has been demonstrated through the generation of Sertoli cell-specific or germ cell-specific Dicer knockouts, as well as the potential application of these findings in the treatment of human male infertility and the development of male contraceptives. It is anticipated that unraveling miRNA functions in the testis will further our understanding of the regulatory mechanisms of mammalian spermatogenesis. PMID- 19875497 TI - The molecular mechanisms regulating germ cell development and potential. AB - Time-critical extracellular stimuli as well as the intrinsic functions of transcriptional regulatory molecules play essential roles in fate determination and differentiation of mouse primordial germ cells (PGCs). We found that the precursor cells of PGCs require E-cadherin-mediated cell-cell interaction and the functions of transcription factor Oct3/4 to be specified to PGCs. In addition, transcriptional factors commonly regulating a number of PGC-specific genes appear important for PGC development, and we demonstrated that PGC-specific expression of the mil-1 gene is controlled by germ cell-conserved regulatory sequences in the 5' flanking region. Once they have undergone specification and differentiation, PGCs normally give rise to gametes, but they maintain the potential to be converted into pluripotential stem cells upon activation of particular signaling pathways. PMID- 19875498 TI - Histone demethylase JHDM2A is involved in male infertility and obesity. AB - Recent studies indicate that histone lysine methylation is subject to enzyme catalyzed reversion, and jumonji C (JmjC) domain-containing proteins have been identified as one of the members of histone demethylases. Although an increasing number of histone demethylases have been identified and biochemically characterized, their biological functions are poorly characterized. To elucidate the physiological functions, we generated the knockout mouse model of dimethylated or monomethylated histone 3 lysine 9 (H3K9me2/1)-specific JmjC domain-containing histone demethylase 2A (JHDM2A; also known as JMJD1A and KDM3A) and showed that JHDM2A is essential for spermatogenesis. Jhdm2a-deficient mice exhibited impaired postmeiotic chromatin condensation, which caused infertility, even though the hormonal levels were maintained. Further molecular and biochemical analysis revealed that JHDM2A directly bound to the core promoter regions of transition nuclear protein 1 (Tnp1) and protamine 1 (Prm1) genes, and it induced the transcriptional activation of these genes by removing H3K9 methylation, which is known as a silencing marker of gene transcription. This work uncovered a role for JHDM2A in spermatogenesis and identified 2 downstream genes that are critical for sperm nuclear condensation. In addition, we also showed that JHDM2A plays a role in regulating fat metabolic gene expression in muscle and brown fat tissue, and the knockout mice exhibited obesity and hyperlipidemia. Thus, JHDM2A possesses organ/tissue-specific target genes, and impairment of this molecule cannot be compensated by other JmjC-containing histone demethylases, suggesting the importance of this molecule in vivo. PMID- 19875499 TI - Relationship between passive permeability, efflux, and predictability of clearance from in vitro metabolic intrinsic clearance. AB - In vitro intrinsic metabolic clearance (CL(int)) is used routinely for compound selection in drug discovery; however, in vitro CL(int) often underpredicts in vivo clearance (CL). Forty-one proprietary compounds and 16 marketed drugs were selected to determine whether permeability and efflux status could influence the predictability of CL from in vitro CL(int) obtained from liver microsomal and hepatocyte incubations. For many of the proprietary compounds examined, rat CL was significantly underpredicted using the well stirred model incorporating both fraction of unbound drug in blood and fraction of unbound drug in the microsomal or hepatocyte incubation. Further analysis revealed that the accuracy of the prediction was differentiated by permeability and P-glycoprotein- (P-gp) and mouse breast cancer resistance protein (mBcrp)-mediated efflux. For proprietary compounds with passive permeability greater than 5 x 10(-6) cm/s and efflux ratios less than 5 in both P-gp- and mBcrp-expressing cells, CL(int) provided reasonable prediction. The average -fold error (AFE) was 1.8 for rat liver microsomes (RLMs) and 2.3 for rat hepatocytes. In contrast, CL was dramatically underpredicted for compounds with passive permeability less than 5 x 10(-6) cm/s; AFEs of 54.4 and 29.2 were observed for RLM and rat hepatocytes, respectively. In vivo CL was also underpredicted for compounds that were good efflux substrates (permeability >5 x 10(-6) cm/s). The AFEs were 7.4 and 8.1 for RLM and rat hepatocytes, respectively. A similar relationship between permeability, efflux status, and human CL prediction reported in the literature was observed for 16 marketed drugs. These data show that permeability and efflux status are determinants for the predictability of CL from in vitro metabolic CL(int). PMID- 19875500 TI - Coupling of liquid chromatography/tandem mass spectrometry and liquid chromatography/solid-phase extraction/NMR techniques for the structural identification of metabolites following in vitro biotransformation of SUR1 selective ATP-sensitive potassium channel openers. AB - SUR1-selective ATP-sensitive potassium channel openers (PCOs) have been shown to be of clinical value for the treatment of several metabolic disorders, including type I and type II diabetes, obesity, and hyperinsulinemia. Taking into account these promising therapeutic benefits, different series of 3-alkylamino-4H-1,2,4 benzothiadiazine 1,1-dioxides structurally related to diazoxide were developed. In view of the lead optimization process of the series, knowledge of absorption, distribution, metabolism, excretion, and toxicity parameters, and more particularly the metabolic fate of these compounds, is a fundamental requirement. For such a purpose, two selected promising compounds [7-chloro-3-isopropylamino 4H-1,2,4-benzothiadiazine 1,1-dioxide (BPDZ 73) and 7-chloro-3-(3-pentylamino)-4H 1,2,4-benzothiadiazine 1,1-dioxide (BPDZ 157)] were incubated in the presence of phenobarbital-induced rat liver microsomes to produce expected mammal in vivo phase I metabolites. The resulting major metabolites were then analyzed by both mass spectrometry (MS) and NMR to completely elucidate their chemical structures. The two compounds were also further incubated in the presence of nontreated rats and human microsomes to compare the metabolic profiles. In the present study, the combined use of an exact mass liquid chromatography (LC)/tandem MS platform and an LC/solid-phase extraction/NMR system allowed the clarification of some unresolved structural assessments in the accurate chemical structure elucidation process of the selected PCO drugs. These results greatly help the optimization of the lead compounds. PMID- 19875501 TI - Investigation of the rate-determining process in the hepatic elimination of HMG CoA reductase inhibitors in rats and humans. AB - Elucidation of the rate-determining process in the overall hepatic elimination of drugs is critical for predicting their intrinsic hepatic clearance and the impact of variation of sequestration clearance on their systemic concentration. The present study investigated the rate-determining process in the overall hepatic elimination of the HMG-CoA reductase inhibitors pravastatin, pitavastatin, atorvastatin, and fluvastatin both in rats and humans. The uptake of these statins was saturable in both rat and human hepatocytes. Intrinsic hepatic clearance obtained by in vivo pharmacokinetic analysis in rats was close to the uptake clearance determined by the multiple indicator dilution method but much greater than the intrinsic metabolic clearance extrapolated from an in vitro model using liver microsomes. In vivo uptake clearance of the statins in humans (pravastatin, 1.44; pitavastatin, 30.6; atorvastatin, 12.7; and fluvastatin, 62.9 ml/min/g liver), which was obtained by multiplying in vitro uptake clearance determined in cryopreserved human hepatocytes by rat scaling factors, was within the range of overall in vivo intrinsic hepatic clearance (pravastatin, 0.84-1.2; pitavastatin, 14-35; atorvastatin, 11-19; and fluvastatin, 123-185 ml/min/g liver), whereas the intrinsic metabolic clearance of atorvastatin and fluvastatin was considerably low compared with their intrinsic hepatic clearance. Their uptake is the rate-determining process in the overall hepatic elimination of the statins in rats, and this activity likely holds true for humans. In vitro-in vivo extrapolation of the uptake clearance using a cryopreserved human hepatocytes model and rat scaling factors will be effective for predicting in vivo intrinsic hepatic clearance involving active uptake. PMID- 19875502 TI - Cytogenetic abnormalities of tumor-associated endothelial cells in human malignant tumors. AB - Tumor blood vessels are thought to contain genetically normal and stable endothelial cells (ECs), unlike tumor cells, which typically display genetic instability. Yet, chromosomal aberration in human tumor-associated ECs (hTECs) in carcinoma has not yet been investigated. Here we isolated TECs from 20 human renal cell carcinomas and analyzed their cytogenetic abnormalities. The degree of aneuploidy was analyzed by fluorescence in situ hybridization using chromosome 7 and chromosome 8 DNA probes in isolated hTECs. In human renal cell carcinomas, 22 58% (median, 33%) of uncultured hTECs were aneuploid, whereas normal ECs were diploid. The mechanisms governing TEC aneuploidy were then studied using mouse TECs (mTECs) isolated from xenografts of human epithelial tumors. To investigate the contribution of progenitor cells to aneuploidy in mTECs, CD133(+) and CD133( ) mTECs were compared for aneuploidy. CD133(+) mTECs showed aneuploidy more frequently than CD133(-) mTECs. This is the first report showing cytogenetic abnormality of hTECs in carcinoma, contrary to traditional belief. Cytogenetic alterations in tumor vessels of carcinoma therefore can occur and may play a significant role in modifying tumor- stromal interactions. PMID- 19875503 TI - Regulating the T-cell immune response toward the H99 strain of Cryptococcus neoformans. PMID- 19875504 TI - Dysferlin deficiency and the development of cardiomyopathy in a mouse model of limb-girdle muscular dystrophy 2B. AB - Limb-girdle muscular dystrophy 2B, Miyoshi myopathy, and distal myopathy of anterior tibialis are severely debilitating muscular dystrophies caused by genetically determined dysferlin deficiency. In these muscular dystrophies, it is the repair, not the structure, of the plasma membrane that is impaired. Though much is known about the effects of dysferlin deficiency in skeletal muscle, little is known about the role of dysferlin in maintenance of cardiomyocytes. Recent evidence suggests that dysferlin deficiency affects cardiac muscle, leading to cardiomyopathy when stressed. However, neither the morphological location of dysferlin in the cardiomyocyte nor the progression of the disease with age are known. In this study, we examined a mouse model of dysferlinopathy using light and electron microscopy as well as echocardiography and conscious electrocardiography. We determined that dysferlin is normally localized to the intercalated disk and sarcoplasm of the cardiomyocytes. In the absence of dysferlin, cardiomyocyte membrane damage occurs and is localized to the intercalated disk and sarcoplasm. This damage results in transient functional deficits at 10 months of age, but, unlike in skeletal muscle, the cell injury is sublethal and causes only mild cardiomyopathy even at advanced ages. PMID- 19875505 TI - Memory reconsolidation and extinction in the crab: mutual exclusion or coexistence? AB - A conditioned stimulus (CS) exposure has the ability to induce two qualitatively different mnesic processes: memory reconsolidation and memory extinction. Previous work from our laboratory has shown that upon a single CS presentation the triggering of one or the other process depends on CS duration (short CS exposure triggers reconsolidation, whereas a long CS exposure triggers extinction), both being mutually exclusive processes. Here we show that either process is triggered only after CS offset, ruling out an interaction as the mechanism of this mutual exclusion. Also, we show here for the first time that reconsolidation and extinction can occur simultaneously without interfering with each other if they are serially triggered by respective short and long CS exposures. Thus, we conclude that (1) one single CS presentation triggers one single process, after CS offset, and (2) whether memory reconsolidation and extinction mutually exclude each other or whether they coexist depends only on whether they are triggered by single or multiple CS presentations. PMID- 19875506 TI - Changes in context-specificity during memory reconsolidation: selective effects of hippocampal lesions. AB - After acquisition, memories associated with contextual fear conditioning pass through a labile phase, in which they are vulnerable to hippocampal lesions, to a more stable state, via consolidation, in which they engage extrahippocampal structures and are resistant to such disruption. The process is accompanied by changes in the form of the memory from being context-specific to context-general. However, when revived by a reminder, stable memories once again become labile and susceptible to hippocampal disruption, and memory reconsolidation is needed to stabilize them. This study addressed two questions with respect to this reconsolidation phenomenon: (1) How do reminders reinstate a hippocampally dependent memory trace? (2) As the memory changes from a stable to a labile state after a reminder, does its form remain invariant, or does it also change? Using contextual manipulations at retrieval in a test of contextual fear conditioning, we showed that when the fear-conditioning environment served as a reminder, the reinstated memory regained its context specificity and, as a result, became vulnerable again to the effects of hippocampal lesions. By comparison, exposure to a different environment during the reminder session reinstated a version of the original memory that was dependent primarily on general features of the original context and, consequently, was less affected by hippocampal lesions. These findings, which relate loss of reactivated memories after hippocampal destruction (or inactivation) to changes in memory representation, are interpreted as consistent with the transformation hypothesis of memory processing. PMID- 19875507 TI - In vitro synergistic activity against CCR5-tropic HIV-1 with combinations of potential candidate microbicide molecules HHA, KRV2110 and enfuvirtide (T20). AB - OBJECTIVES: To block the different mechanisms of HIV mucosal transmission, it is likely that use of several microbicide molecules will lead to the best protection against HIV transmission. Indeed, the combination of microbicides with complementary mechanisms of action is expected to increase the antiviral potency of the formulation. METHODS: The gp120-interacting plant lectin HHA ('Hippeastrum hybrid agglutinin'), the non-nucleoside reverse transcriptase inhibitor KRV2110 and the fusion inhibitor enfuvirtide (T20) were combined in 12 drug associations by using the Ray combination design method. Their activity against HIV-1(BaL) was assessed by the lymphocyte infectivity reduction assay and by the single-cycle BaL pseudovirus (PV) assay. In addition, their cell tolerance was evaluated for HEC-1 and HeLa epithelial cell lines, both originating from genital tissue. RESULTS: All evaluated combinations showed synergistic activity in both lymphocyte infectivity reduction and single-cycle BaL PV assays. The combination HHA + KRV2110 resulted in the highest cell viability, whereas the combinations including T20 exhibited a dose-dependent decrease in cell viability, demonstrating the differential tolerance of epithelial cell lines to the combinations. CONCLUSIONS: These observations provide a rational basis for in vitro testing of microbicide candidate molecule combinations, including anti-HIV 1 and cytotoxic cellular assays. PMID- 19875508 TI - Can vaginal misoprostol effectively increase rate of a satisfactory colposcopy? A randomized double-blind placebo-controlled trial. AB - OBJECTIVE: To evaluate the effectiveness of vaginal misoprostol in overcoming an unsatisfactory colposcopy in the patients who had abnormal cervical cytology and to evaluate side effects of vaginal misoprostol. METHODS: Sixty patients with an unsatisfactory colposcopy during the period of September 2007-November 2008 were recruited and randomly allocated to receive either two tablets of 200 microg misoprostol (400 microg) or two tablets of similar-looking placebo vaginally. Colposcopic re-examination was performed approximately 6 h later. The results and side effects before and 2 weeks after the colposcopic re-examination were recorded. RESULTS: Six out of 30 patients in the misoprostol group (20.0%) had a satisfactory colposcopic re-examination compared with 2 out of 27 patients (7.4%) in the placebo group without statistically significant difference (P = 0.172). Three patients in the placebo group dropped out due to not present at the appointment time. Six out of 30 patients (20.0%) and 1 out of 30 patients (3.3%) in the misoprostol group had side effects before and 2 weeks after the colposcopic re-examination orderly. Twenty-seven patients in the placebo group did not have any side effects before and 2 weeks after the colposcopic re examination. All side effects occurred were minimal and well tolerated. CONCLUSIONS: Four hundred micrograms of vaginal misoprostol were not proved to be effective in converting an unsatisfactory to a satisfactory colposcopy. PMID- 19875509 TI - In vitro interactions between primycin and different statins in their effects against some clinically important fungi. AB - The in vitro antifungal activities of primycin (PN) and various statins against some opportunistic pathogenic fungi were investigated. PN completely inhibited the growth of Candida albicans (MIC 64 microg ml(-1)) and Candida glabrata (MIC 32 microg ml(-1)), and was very effective against Paecilomyces variotii (MIC 2 microg ml(-1)), but had little effect on Aspergillus fumigatus, Aspergillus flavus or Rhizopus oryzae (MICs >64 microg ml(-1)). The fungi exhibited different degrees of sensitivity to the statins; fluvastatin (FLV) and simvastatin (SIM) exerted potent antifungal activities against a wide variety of clinically important fungal pathogens. Atorvastatin, rosuvastatin and lovastatin (LOV) had a slight effect against all fungal isolates tested, whereas pravastatin was completely ineffective. The in vitro interactions between PN and the different statins were investigated using a standard chequerboard titration method. When PN was combined with FLV, LOV or SIM, both synergistic and additive effects were observed. The extent of inhibition was higher when these compounds were applied together, and the concentrations of PN and the given statin needed to block fungal growth completely could be decreased by several dilution steps. Similar interactions were observed when the variability of the within-species sensitivities was investigated. PMID- 19875510 TI - Effects of parental larval diet on egg size and offspring traits in Drosophila. AB - If a mother's nutritional status predicts the nutritional environment of the offspring, it would be adaptive for mothers experiencing nutritional stress to prime their offspring for a better tolerance to poor nutrition. We report that in Drosophila melanogaster, parents raised on poor larval food laid 3-6% heavier eggs than parents raised on standard food, despite being 30 per cent smaller. Their offspring developed 14 h (4%) faster on the poor food than offspring of well-fed parents. However, they were slightly smaller as adults. Thus, the effects of parental diet on offspring performance under malnutrition apparently involve both adaptive plasticity and maladaptive effects of parental stress. PMID- 19875512 TI - Micropapillary pattern in lung adenocarcinoma: aspect on 18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging. AB - We diagnosed a non-small cell lung carcinoma in a 49-year-old female patient with the histopathological diagnosis of stage IIIB mixed bronchioloalveolar and papillary adenocarcinoma with extensive micropapillary feature, which was not visualized on the preoperative multimodality imaging with positron emission tomography (PET) and computed tomography (CT). The micropapillary component characterized by a unique growth pattern with particular morphological features can be observed in all subtypes of lung adenocarcinoma. Micropapillary component is increasingly recognized as a distinct entity associated with higher aggressiveness. Even the most modern multimodality PET/CT imaging technology may fail to adequately visualize this important component with highly relevant prognostic implications. Thus, the pathologist needs to consciously look for a micropapillary component in the surgical specimen or in preoperative biopsies or cytology. This may have potential future treatment implications, as adjuvant or neoadjuvant chemotherapy may be of relevance, even in the early stages of the disease. PMID- 19875511 TI - Novel regulation of HIV-1 replication and pathogenicity: Rev inhibition of integration. AB - Following fusion of the human immunodeficiency virus type-1 (HIV-1) with host cells' membrane and reverse transcription of the viral RNA, the resulted cDNA is integrated into the host genome by the viral integrase enzyme (IN). Quantitative estimations have revealed that only 1-2 copies are integrated per infected cell, although many copies of the viral RNA are reverse-transcribed. The molecular mechanism that restricts the integration degree has not, so far, been elucidated. Following integration, expressed partially spliced and unspliced transcripts are exported from the nuclei by the viral Rev protein. Here, we show that in virally infected cells, the Rev interacts with the IN forming a Rev-IN complex and consequently limits the number of integration events. Disruption of the Rev-IN complex by selected IN-derived peptides or infection by a Rev-deficient virus stimulate integration resulting in large numbers of integration event/cell. Conversely, infection of Rev-expression cells blocks integration and inhibits virus production. Increased integration appears to correlate with increased cell death of infected cultures. Our results thus demonstrate a new regulatory function of Rev and probably establish a link between Rev restriction of HIV-1 integration and protection of HIV-1-infected cells from premature cell death. PMID- 19875513 TI - Treatment of an acquired esophageal-bibronchial benign fistula using an original combination of techniques. AB - We report on the successful surgical treatment of an esophageal-bibronchial fistula originating from an iatrogenic mediastinal abscess. Endoscopic treatment had been excluded due to the extensive damage to the right main stem bronchus wall. The surgical treatment was carried out as follows: 1) Endoscopic stenting of the left main bronchus with a self-expanding metallic stent followed by selective left main bronchus intubation; 2) Laparotomic harvesting of the omentum pedicled on both gastro-epiploic vessels; 3) Right thoracotomy, complete dissection of both main bronchi and esophageal wall at the site of the leakage; 4) Harvesting of a pericardial vascularized graft; 5) Deployment of a self expanding metallic stent from the surgical field into the right main stem bronchus; 6) Reconstruction of the right bronchus wall with the pericardial patch; 7) Positioning a T-tube in the esophageal leak; and 8) Intrathoracic transposition of the omental graft for buttressing all sutures and potential leakage points. The postoperative course was uneventful from a surgical point of view and the patient recovered completely. PMID- 19875519 TI - The impact of plant and flower age on mating patterns. AB - BACKGROUND: Over a season, plant condition, amount of ongoing reproduction and biotic and abiotic environmental factors vary. As flowers age, flower condition and amount of pollen donated and received also vary. These internal and external changes are significant for fitness if they result in changes in reproduction and mating. SCOPE: Literature from several fields was reviewed to provide a picture of the changes that occur in plants and flowers that can affect mating over a season. As flowers age, both the entire flower and individual floral whorls show changes in appearance and function. Over a season, changes in mating often appear as alteration in seed production vs. pollen donation. In several species, older, unpollinated flowers are more likely to self. If flowers are receiving pollen, staying open longer may increase the number of mates. In wild radish, for which there is considerable information on seed paternity, older flowers produce fewer seeds and appear to discriminate less among pollen donors. Pollen donor performance can also be linked to maternal plant age. Different pollinators and mates are available across the season. Also in wild radish, maternal plants appear to exert the most control over paternity when they are of intermediate age. CONCLUSIONS: Although much is known about the characters of plants and flowers that can change over a season, there is less information on the effects of age on mating. Several studies document changes in self-pollination over time, but very few, other than those on wild radish, consider more subtle aspects of differential success of pollen donors over time. PMID- 19875520 TI - Donors, donors, and more donors. PMID- 19875521 TI - TPO-mimetics and myelofibrosis? A reticulin question! PMID- 19875522 TI - HIV infection: TRAILing the killers. PMID- 19875523 TI - Turning up the heat on myeloma. PMID- 19875524 TI - Granzyme A is a proinflammatory protease. PMID- 19875526 TI - Clonotypic B cells in classic Hodgkin lymphoma. PMID- 19875528 TI - Is the recommended daily iron intake for women too low? PMID- 19875529 TI - Three deadly sins: hierarchy, etiquette and conformity. PMID- 19875530 TI - Are memory clinics effective? The odds are in favour of their benefit, but conclusive evidence is not yet available. PMID- 19875531 TI - Cure or cocoa? PMID- 19875532 TI - Competitive culture does not guarantee improved quality. PMID- 19875533 TI - Surgeons and safety. PMID- 19875534 TI - Preventing premature mortality in chronic diseases for South Asians in the UK and beyond. PMID- 19875535 TI - From practice guidelines to clinical decision support: closing the loop. PMID- 19875537 TI - Uncomfortable prescribing decisions in hospitals: the impact of teamwork. AB - OBJECTIVES: Prescribing is not always driven by therapeutic motives alone; social and intrinsic factors also play a part in the decision. However, most research into prescribing influences has been conducted in general practice, with very little conducted within hospitals. One potential influence is the hospital multidisciplinary team, yet little attention has been paid to how interactions between teams and team members may influence prescribing. This study investigated the effect that team interaction and structure had upon UK hospital doctors' prescribing decisions, particularly their discomfort felt prescribing. DESIGN AND SETTING: The study used the critical incident technique and in-depth interviews. Prior to an in-depth interview, 48 doctors of varying grades from four hospitals were asked to remember any uncomfortable prescribing decisions that they had recently made. These 'incidents' were discussed in depth. All interviews were tape-recorded and transcribed verbatim. A grounded theory approach to data analysis was taken. RESULTS: There were 193 critical incidents described in the interviews. Over one-third were related to the difficulties of prescribing within a team environment. Discomfort frequently arose because of factors relating to the hierarchical structure; in particular, junior doctors described their discomfort when they were uncertain of seniors' prescribing decisions. Prescribers also adhered to rules of prescribing etiquette, including the maintenance of other doctors'/teams' prescribing decisions and adherence to prescribing norms. Discomfort also arose from a perceived pressure to prescribe from the nursing team. Doctors admitted to prescribing to maintain overall team relationships, sometimes ignoring hospital regulations and best practice to do so. CONCLUSION: Overall, this study demonstrated that hospital doctors' prescribing decisions were strongly influenced by relationships with other team members, particularly nurses and senior doctors. Ways of reducing this discomfort should be explored and further research is advocated in this area. PMID- 19875538 TI - Asymptomatic pericardial calcification in Whipple's disease. PMID- 19875536 TI - An alternative approach to medical genetics based on modern evolutionary biology. Part 4: HERVs in cancer. PMID- 19875539 TI - Cricoarytenoid arthritis presenting as croup. PMID- 19875542 TI - Introduction to the Second World Congress on Controversies to Consensus in Diabetes, Obesity and Hypertension (CODHy): dilemmas in clinical practice. PMID- 19875543 TI - Defining and characterizing the progression of type 2 diabetes. PMID- 19875544 TI - Skeletal muscle insulin resistance is the primary defect in type 2 diabetes. PMID- 19875545 TI - Viewpoints on the way to a consensus session: where does insulin resistance start? The liver. PMID- 19875546 TI - Viewpoints on the way to the consensus session: where does insulin resistance start? The adipose tissue. PMID- 19875547 TI - Where does insulin resistance start? The brain. PMID- 19875548 TI - Goals of treatment for type 2 diabetes: beta-cell preservation for glycemic control. PMID- 19875549 TI - Combined pharmacologic/nonpharmacologic intervention in individuals at high risk of developing type 2 diabetes: pro pharmacologic therapy. PMID- 19875550 TI - Nonpharmacologic therapy and exercise in the prevention of type 2 diabetes. AB - OBJECTIVE: To review the current knowledge about nonpharmacologic approaches in the prevention and early treatment of type 2 diabetes. RESEARCH DESIGN AND METHODS: This study reviewed the research reports dealing with nonpharmacologic interventions aimed at preventing type 2 diabetes with early lifestyle interventions. RESULTS: The results from the randomized controlled trials all show that people with impaired glucose tolerance who received enhanced lifestyle advice had significantly lower (on average approximately 50% reduced) incidence of type 2 diabetes compared with those allocated to receive "usual care." Individuals who were able to correct their lifestyle habits as recommended for usual healthy life patterns were mostly protected against type 2 diabetes. Thus, compelling evidence exists that most of the cases of type 2 diabetes can be prevented or at least the onset of the disease can be significantly delayed. CONCLUSIONS: Randomized controlled trials have unequivocally demonstrated that lifestyle management is highly efficient in the prevention and also in the early management of type 2 diabetes. This evidence of lifestyle modification in diabetes prevention is stronger than for most other multifactorial diseases. PMID- 19875551 TI - Plasma glucose concentration and prediction of future risk of type 2 diabetes. PMID- 19875552 TI - Target for glycemic control: concentrating on glucose. PMID- 19875553 TI - Self-monitoring of blood glucose as part of the integral care of type 2 diabetes. AB - Results from landmark diabetes studies have established A1C as the gold standard for assessing long-term glycemic control. However, A1C does not provide "real time" information about individual hyperglycemic or hypoglycemic excursions. Real time information provided by self-monitoring of blood glucose (SMBG) represents an important adjunct to A1C, because it can differentiate fasting, preprandial, and postprandial hyperglycemia; detect glycemic excursions; identify hypoglycemia; and provide immediate feedback about the effect of food choices, physical activity, and medication on glycemic control. The importance of SMBG is widely appreciated and recommended as a core component of management in patients with type 1 or insulin-treated type 2 diabetes, as well as in diabetic pregnancy, for both women with pregestational type 1 and gestational diabetes. Nevertheless, SMBG in management of non-insulin-treated type 2 diabetic patients continues to be debated. Results from clinical trials are inconclusive, and reviews fail to reach an agreement, mainly because of methodological problems. Carefully designed large-scale studies on diverse patient populations with type 2 diabetes with the follow-up period to investigate long-term effects of SMBG in patients with type 2 diabetes should be carried out to clarify how to make the best use of SMBG, in which patients, and under what conditions. PMID- 19875554 TI - Telemedical artificial pancreas: PARIS (Pancreas Artificial Telemedico Inteligente) research project. PMID- 19875555 TI - Changing the treatment paradigm for type 2 diabetes. PMID- 19875556 TI - Incretin-based therapies: viewpoints on the way to consensus. PMID- 19875557 TI - Antioxidant anti-inflammatory treatment in type 2 diabetes. PMID- 19875558 TI - Bile acids and metabolic regulation: mechanisms and clinical responses to bile acid sequestration. PMID- 19875559 TI - Beta-cell protection and therapy for latent autoimmune diabetes in adults. PMID- 19875560 TI - Insulin therapy for type 2 diabetes. PMID- 19875561 TI - Initiating insulin therapy in type 2 diabetic patients failing on oral hypoglycemic agents: basal or prandial insulin? The APOLLO trial and beyond. PMID- 19875562 TI - Early insulin treatment in type 2 diabetes: what are the pros? PMID- 19875563 TI - Early insulin use in type 2 diabetes: what are the cons? PMID- 19875564 TI - How to define prehypertension in diabetes/metabolic syndrome. PMID- 19875565 TI - Should we treat prehypertension in diabetes? What are the cons? PMID- 19875566 TI - Treatment of prehypertension in diabetes and metabolic syndrome: what are the pros? PMID- 19875567 TI - Hypertension and diabetes: should we treat early surrogates? What are the cons? PMID- 19875568 TI - Hypertension and Diabetes: what are the pros to treating early surrogates? PMID- 19875569 TI - Should 24-h ambulatory blood pressure monitoring be done in every patient with diabetes? PMID- 19875570 TI - Should white-coat hypertension in diabetes be treated? Pro. PMID- 19875571 TI - White-coat hypertension should not be treated in subjects with diabetes. PMID- 19875572 TI - Endothelial dysfunction as a target for prevention of cardiovascular disease. PMID- 19875573 TI - Implications of postprandial glucose and weight control in people with type 2 diabetes: understanding and implementing the International Diabetes Federation guidelines. PMID- 19875574 TI - The Munich Myocardial Infarction Registry: translating the European Society of Cardiology (ESC) and European Association for the Study of Diabetes (EASD) guidelines on diabetes, pre-diabetes, and cardiovascular disease into clinical practice. PMID- 19875575 TI - Is hyperglycemia a causal factor in cardiovascular disease? Does proving this relationship really matter? Yes. PMID- 19875576 TI - Glucose control and cardiovascular disease: is it important? No. PMID- 19875577 TI - Is there evidence that oral hypoglycemic agents reduce cardiovascular morbidity or mortality? No. PMID- 19875578 TI - Is there evidence that oral hypoglycemic agents reduce cardiovascular morbidity/mortality? Yes. PMID- 19875579 TI - Shifting the disease management paradigm from glucose: what are the pros? PMID- 19875580 TI - Shifting the disease management paradigm from glucose: what are the cons? PMID- 19875581 TI - A summary of the ADVANCE Trial. PMID- 19875582 TI - Adipocytokines and insulin resistance: the possible role of lipocalin-2, retinol binding protein-4, and adiponectin. PMID- 19875583 TI - Diabetes surgery: a new approach to an old disease. PMID- 19875584 TI - Triglycerides and HDL cholesterol: stars or second leads in diabetes? PMID- 19875585 TI - Should all diabetic patients be treated with a statin? PMID- 19875586 TI - American Diabetes Association indications for statins in diabetes: is there evidence? PMID- 19875587 TI - Fat or fit: what is more important? PMID- 19875588 TI - Obesity in elderly subjects: in sheep's clothing perhaps, but still a wolf! PMID- 19875589 TI - Obesity in the elderly diabetic patient: is weight loss beneficial? No. PMID- 19875590 TI - Dual blockade of the renin-angiotensin system in diabetic nephropathy. PMID- 19875591 TI - Painful diabetic neuropathy: advantage of novel drugs over old drugs? PMID- 19875592 TI - Microvascular complications in diabetic erectile dysfunction: do we need other alternatives? PMID- 19875593 TI - Smoking cessation: it is never too late. PMID- 19875594 TI - Why won't our patients stop smoking? The power of nicotine addiction. PMID- 19875596 TI - The 6th Annual World Congress on the Insulin Resistance Syndrome. PMID- 19875595 TI - Smoking amplifies cardiovascular risk in patients with hypertension and diabetes. PMID- 19875597 TI - Quality of life, coping ability, and metabolic control in patients with type 1 diabetes managed by group care and a carbohydrate counting program. PMID- 19875598 TI - Lower vital capacity is associated with diabetes but not with metabolic syndrome in nonobese Japanese men: Response to Oda and Kawai. PMID- 19875599 TI - Lower vital capacity is associated with diabetes but not with metabolic syndrome in nonobese Japanese men: Response to Nakajima and Saito. PMID- 19875600 TI - Increased matrix metalloproteinase-9 predicts poor wound healing in diabetic foot ulcers: Response to Muller et al. PMID- 19875601 TI - Increased matrix metalloproteinase-9 predicts poor wound healing in diabetic foot ulcers: Response to Liu et al. PMID- 19875602 TI - Predictors of overweight during childhood in offspring of parents with type 1 diabetes: Response to Rodekamp et al. PMID- 19875603 TI - Predictors of overweight during childhood in offspring of parents with type 1 diabetes: Response to Hummel et al. PMID- 19875604 TI - Association of A1C and fasting plasma glucose levels with diabetic retinopathy prevalence in the U.S. population: Implications for diabetes diagnostic thresholds. AB - OBJECTIVE: To examine the association of A1C levels and fasting plasma glucose (FPG) with diabetic retinopathy in the U.S. population and to compare the ability of the two glycemic measures to discriminate between people with and without retinopathy. RESEARCH DESIGN AND METHODS: This study included 1,066 individuals aged >or=40 years from the 2005-2006 National Health and Nutrition Examination Survey. A1C, FPG, and 45 degrees color digital retinal images were assessed. Retinopathy was defined as a level >or=14 on the Early Treatment Diabetic Retinopathy Study severity scale. We used joinpoint regression to identify linear inflections of prevalence of retinopathy in the association between A1C and FPG. RESULTS: The overall prevalence of retinopathy was 11%, which is appreciably lower than the prevalence in people with diagnosed diabetes (36%). There was a sharp increase in retinopathy prevalence in those with A1C >or=5.5% or FPG >or=5.8 mmol/l. After excluding 144 people using hypoglycemic medication, the change points for the greatest increase in retinopathy prevalence were A1C 5.5% and FPG 7.0 mmol/l. The coefficients of variation were 15.6 for A1C and 28.8 for FPG. Based on the areas under the receiver operating characteristic curves, A1C was a stronger discriminator of retinopathy (0.71 [95% CI 0.66-0.76]) than FPG (0.65 [0.60 - 0.70], P for difference = 0.009). CONCLUSIONS: The steepest increase in retinopathy prevalence occurs among individuals with A1C >or=5.5% and FPG >or=5.8 mmol/l. A1C discriminates prevalence of retinopathy better than FPG. PMID- 19875605 TI - Autologous umbilical cord blood transfusion in very young children with type 1 diabetes. AB - OBJECTIVE: Interest continues to grow regarding the therapeutic potential for umbilical cord blood therapies to modulate autoimmune disease. We conducted an open-label phase I study using autologous umbilical cord blood infusion to ameliorate type 1 diabetes. RESEARCH DESIGN AND METHODS: Fifteen patients diagnosed with type 1 diabetes and for whom autologous umbilical cord blood was stored underwent a single intravenous infusion of autologous cells and completed 1 year of postinfusion follow-up. Intensive insulin regimens were used to optimize glycemic control. Metabolic and immunologic assessments were performed before infusion and at established time periods thereafter. RESULTS: Median (interquartile range [IQR]) age at infusion was 5.25 (3.1-7.3) years, with a median postdiagnosis time to infusion of 17.7 (10.9-26.5) weeks. No infusion related adverse events were observed. Metabolic indexes 1 year postinfusion were peak C-peptide median 0.50 ng/ml (IQR 0.26-1.30), P = 0.002; A1C 7.0% (IQR 6.5 7.7), P = 0.97; and insulin dose 0.67 units * kg(-1) * day(-1) (IQR 0.55-0.77), P = 0.009. One year postinfusion, no changes were observed in autoantibody titers, regulatory T-cell numbers, CD4-to-CD8 ratio, or other T-cell phenotypes. CONCLUSIONS: Autologous umbilical cord blood transfusion in children with type 1 diabetes is safe but has yet to demonstrate efficacy in preserving C-peptide. Larger randomized studies as well as 2-year postinfusion follow-up of this cohort are needed to determine whether autologous cord blood-based approaches can be used to slow the decline of endogenous insulin production in children with type 1 diabetes. PMID- 19875606 TI - Prediction of coronary heart disease risk in a general, pre-diabetic, and diabetic population during 10 years of follow-up: accuracy of the Framingham, SCORE, and UKPDS risk functions: The Hoorn Study. AB - OBJECTIVE: To test the validity of the Framingham, Systematic Coronary Risk Evaluation (SCORE), and UK Prospective Diabetes Study (UKPDS) risk function in the prediction of risk of coronary heart disease (CHD) in populations with normal glucose tolerance (NGT), intermediate hyperglycemia, and type 2 diabetes. RESEARCH DESIGN AND METHODS: Calibration and discrimination of the three prediction models were tested using prospective data for 1,482 Caucasian men and women, 50-75 years of age, who participated in the Hoorn Study. All analyses were stratified by glucose status. RESULTS: During 10 years of follow-up, a total of 197 CHD events, of which 43 were fatal, were observed in this population, with the highest percentage of first CHD events in the diabetic group. The Framingham and UKPDS prediction models overestimated the risk of first CHD event in all glucose tolerance groups. Overall, the prediction models had a low to moderate discriminatory capacity. The SCORE risk function was the best predictor of fatal CHD events in the group with NGT (area under the receiver operating characteristic curve 0.79 [95% CI 0.70-0.87]), whereas the UKPDS performed better in the intermediate hyperglycemia group (0.84 [0.74-0.94]) in the estimation of fatal CHD risk. After exclusion of known diabetic patients, all prediction models had a higher discriminatory ability in the group with diabetes. CONCLUSIONS: The use of the Framingham function for prediction of the first CHD event is likely to overestimate an individual's absolute CHD risk. In CHD prevention, application of the SCORE and UKPDS functions might be useful in the absence of a more valid tool. PMID- 19875607 TI - Alcohol as a risk factor for type 2 diabetes: A systematic review and meta analysis. AB - OBJECTIVE: To clarify the dose-response relationship between alcohol consumption and type 2 diabetes. RESEARCH DESIGN AND METHODS: A systematic computer-assisted and hand search was conducted to identify relevant articles with longitudinal design and quantitative measurement of alcohol consumption. Adjustment was made for the sick-quitter effect. We used fractional polynomials in a meta-regression to determine the dose-response relationships by sex and end point using lifetime abstainers as the reference group. RESULTS: The search revealed 20 cohort studies that met our inclusion criteria. A U-shaped relationship was found for both sexes. Compared with lifetime abstainers, the relative risk (RR) for type 2 diabetes among men was most protective when consuming 22 g/day alcohol (RR 0.87 [95% CI 0.76-1.00]) and became deleterious at just over 60 g/day alcohol (1.01 [0.71-1.44]). Among women, consumption of 24 g/day alcohol was most protective (0.60 [0.52-0.69]) and became deleterious at about 50 g/day alcohol (1.02 [0.83 1.26]). CONCLUSIONS: Our analysis confirms previous research findings that moderate alcohol consumption is protective for type 2 diabetes in men and women. PMID- 19875608 TI - How do we define cure of diabetes? PMID- 19875609 TI - Diabetes, muscles, and the myth of Ulysses' bow. PMID- 19875610 TI - Umbilical cord blood and type 1 diabetes: A road ahead or dead end? PMID- 19875611 TI - Can we become victims of our own success? PMID- 19875612 TI - Remodeling of retinal Fatty acids in an animal model of diabetes: a decrease in long-chain polyunsaturated fatty acids is associated with a decrease in fatty acid elongases Elovl2 and Elovl4. AB - OBJECTIVE: The results of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications cohort study revealed a strong association between dyslipidemia and the development of diabetic retinopathy. However, there are no experimental data on retinal fatty acid metabolism in diabetes. This study determined retinal-specific fatty acid metabolism in control and diabetic animals. RESEARCH DESIGN AND METHODS: Tissue gene and protein expression profiles were determined by quantitative RT-PCR and Western blot in control and streptozotocin-induced diabetic rats at 3-6 weeks of diabetes. Fatty acid profiles were assessed by reverse-phase high-performance liquid chromatography, and phospholipid analysis was performed by nano electrospray ionization tandem mass spectrometry. RESULTS: We found a dramatic difference between retinal and liver elongase and desaturase profiles with high elongase and low desaturase gene expression in the retina compared with liver. Elovl4, an elongase expressed in the retina but not in the liver, showed the greatest expression level among retinal elongases, followed by Elovl2, Elovl1, and Elovl6. Importantly, early-stage diabetes induced a marked decrease in retinal expression levels of Elovl4, Elovl2, and Elovl6. Diabetes-induced downregulation of retinal elongases translated into a significant decrease in total retinal docosahexaenoic acid, as well as decreased incorporation of very long-chain polyunsaturated fatty acids (PUFAs), particularly 32:6n3, into retinal phosphatidylcholine. This decrease in n3 PUFAs was coupled with inflammatory status in diabetic retina, reflected by an increase in gene expression of proinflammatory markers interleukin-6, vascular endothelial growth factor, and intercellular adhesion molecule-1. CONCLUSIONS: This is the first comprehensive study demonstrating diabetes-induced changes in retinal fatty acid metabolism. Normalization of retinal fatty acid levels by dietary means or/and modulating expression of elongases could represent a potential therapeutic target for diabetes-induced retinal inflammation. PMID- 19875613 TI - Defects in IL-2R signaling contribute to diminished maintenance of FOXP3 expression in CD4(+)CD25(+) regulatory T-cells of type 1 diabetic subjects. AB - OBJECTIVE: In humans, multiple genes in the interleukin (IL)-2/IL-2 receptor (IL 2R) pathway are associated with type 1 diabetes. However, no link between IL-2 responsiveness and CD4(+)CD25(+)FOXP3(+) regulatory T-cells (Tregs) has been demonstrated in type 1 diabetic subjects despite the role of these IL-2-dependent cells in controlling autoimmunity. Here, we address whether altered IL-2 responsiveness impacts persistence of FOXP3 expression in Tregs of type 1 diabetic subjects. RESEARCH DESIGN AND METHODS: Persistence of Tregs was assessed by culturing sorted CD4(+)CD25(hi) natural Tregs with IL-2 and measuring FOXP3 expression over time by flow cytometry for control and type 1 diabetic populations. The effects of IL-2 on FOXP3 induction were assessed 48 h after activation of CD4(+)CD25(-) T-cells with anti-CD3 antibody. Cytokine receptor expression and signaling upon exposure to IL-2, IL-7, and IL-15 were determined by flow cytometry and Western blot analysis. RESULTS: Maintenance of FOXP3 expression in CD4(+)CD25(+) Tregs of type 1 diabetic subjects was diminished in the presence of IL-2, but not IL-7. Impaired responsiveness was not linked to altered expression of the IL-2R complex. Instead, IL-2R signaling was reduced in Tregs and total CD4(+) T-cells of type 1 diabetic subjects. In some individuals, decreased signal transducer and activator of transcription 5 phosphorylation correlated with significantly higher expression of protein tyrosine phosphatase N2, a negative regulator of IL-2R signaling. CONCLUSIONS: Aberrant IL-2R signaling in CD4(+) T-cells of type 1 diabetic subjects contributes to decreased persistence of FOXP3 expression that may impact establishment of tolerance. These findings suggest novel targets for treatment of type 1 diabetes within the IL-2R pathway and suggest that an altered IL-2R signaling signature may be a biomarker for type 1 diabetes. PMID- 19875614 TI - A genome-wide association study identifies a novel major locus for glycemic control in type 1 diabetes, as measured by both A1C and glucose. AB - OBJECTIVE: Glycemia is a major risk factor for the development of long-term complications in type 1 diabetes; however, no specific genetic loci have been identified for glycemic control in individuals with type 1 diabetes. To identify such loci in type 1 diabetes, we analyzed longitudinal repeated measures of A1C from the Diabetes Control and Complications Trial. RESEARCH DESIGN AND METHODS: We performed a genome-wide association study using the mean of quarterly A1C values measured over 6.5 years, separately in the conventional (n = 667) and intensive (n = 637) treatment groups of the DCCT. At loci of interest, linear mixed models were used to take advantage of all the repeated measures. We then assessed the association of these loci with capillary glucose and repeated measures of multiple complications of diabetes. RESULTS: We identified a major locus for A1C levels in the conventional treatment group near SORCS1 (10q25.1, P = 7 x 10(-10)), which was also associated with mean glucose (P = 2 x 10(-5)). This was confirmed using A1C in the intensive treatment group (P = 0.01). Other loci achieved evidence close to genome-wide significance: 14q32.13 (GSC) and 9p22 (BNC2) in the combined treatment groups and 15q21.3 (WDR72) in the intensive group. Further, these loci gave evidence for association with diabetic complications, specifically SORCS1 with hypoglycemia and BNC2 with renal and retinal complications. We replicated the SORCS1 association in Genetics of Diabetes in Kidneys (GoKinD) study control subjects (P = 0.01) and the BNC2 association with A1C in nondiabetic individuals. CONCLUSIONS: A major locus for A1C and glucose in individuals with diabetes is near SORCS1. This may influence the design and analysis of genetic studies attempting to identify risk factors for long-term diabetic complications. PMID- 19875615 TI - Lack of TXNIP protects against mitochondria-mediated apoptosis but not against fatty acid-induced ER stress-mediated beta-cell death. AB - OBJECTIVE: We have previously shown that lack of thioredoxin-interacting protein (TXNIP) protects against diabetes and glucotoxicity-induced beta-cell apoptosis. Because the role of TXNIP in lipotoxicity is unknown, the goal of the present study was to determine whether TXNIP expression is regulated by fatty acids and whether TXNIP deficiency also protects beta-cells against lipoapoptosis. RESARCH DESIGN AND METHODS: To determine the effects of fatty acids on beta-cell TXNIP expression, INS-1 cells and isolated islets were incubated with/without palmitate and rats underwent cyclic infusions of glucose and/or Intralipid prior to islet isolation and analysis by quantitative real-time RT-PCR and immunoblotting. Using primary wild-type and TXNIP-deficient islets, we then assessed the effects of palmitate on apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]), mitochondrial death pathway (cytochrome c release), and endoplasmic reticulum (ER) stress (binding protein [BiP], C/EBP homologous protein [CHOP]). Effects of TXNIP deficiency were also tested in the context of staurosporine (mitochondrial damage) or thapsigargin (ER stress). RESULTS: Glucose elicited a dramatic increase in islet TXNIP expression both in vitro and in vivo, whereas fatty acids had no such effect and, when combined with glucose, even abolished the glucose effect. We also found that TXNIP deficiency does not effectively protect against palmitate or thapsigargin-induced beta-cell apoptosis, but specifically prevents staurosporine- or glucose-induced toxicity. CONCLUSIONS: Our results demonstrate that unlike glucose, fatty acids do not induce beta-cell expression of proapoptotic TXNIP. They further reveal that TXNIP deficiency specifically inhibits the mitochondrial death pathway underlying beta-cell glucotoxicity, whereas it has very few protective effects against ER stress-mediated lipoapoptosis. PMID- 19875617 TI - The modulatory effects of garlic oil on hepatic cytochrome P450s in mice. AB - In order to probe into the effects of garlic oil (GO) on the hepatic CYP2E1, CYP1A2 and CYP3A, male Kun-Ming mice were treated with GO (100 mg/kg body weight) or corn oil for 1 day or consecutive 60 days, respectively, and then the protein expressions and the activities of the enzymes were examined. GO did not alter the physical activities of mice and did not induce lesion to the liver. However, it dramatically inhibited the activities and protein levels of hepatic CYP2E1 and 1A2, but not CYP3A. In addition, we noticed that the inhibition of CYP2E1 and 1A2 by GO was more potent in group of 1 day treatment than those in group of 60 days treatment. Compared with the respective control value, the protein levels of CYP2E1 were decreased by 87.40% (p < .01) and 62.26% (p < .01) by 1 day and 60 days of GO treatment, respectively, while the CYP1A2 protein levels were decreased by 70.76% (p < .01) and 41.49% (p < .01), respectively. These data indicated that the mice could adapt to the prolonged treatment, which might be one reasonable explanation for the conflicting data in the literature. The CYP2E1 and 1A2 suppression might contribute to its hepatoprotection, and data about CYP3A indicated that GO was unlikely to alter the metabolism of the concomitantly used drugs. PMID- 19875616 TI - Maternal age at birth and childhood type 1 diabetes: a pooled analysis of 30 observational studies. AB - OBJECTIVE: The aim if the study was to investigate whether children born to older mothers have an increased risk of type 1 diabetes by performing a pooled analysis of previous studies using individual patient data to adjust for recognized confounders. RESEARCH DESIGN AND METHODS: Relevant studies published before June 2009 were identified from MEDLINE, Web of Science, and EMBASE. Authors of studies were contacted and asked to provide individual patient data or conduct prespecified analyses. Risk estimates of type 1 diabetes by maternal age were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were used to derive combined odds ratios and to investigate heterogeneity among studies. RESULTS: Data were available for 5 cohort and 25 case-control studies, including 14,724 cases of type 1 diabetes. Overall, there was, on average, a 5% (95% CI 2-9) increase in childhood type 1 diabetes odds per 5-year increase in maternal age (P = 0.006), but there was heterogeneity among studies (heterogeneity I(2) = 70%). In studies with a low risk of bias, there was a more marked increase in diabetes odds of 10% per 5-year increase in maternal age. Adjustments for potential confounders little altered these estimates. CONCLUSIONS: There was evidence of a weak but significant linear increase in the risk of childhood type 1 diabetes across the range of maternal ages, but the magnitude of association varied between studies. A very small percentage of the increase in the incidence of childhood type 1 diabetes in recent years could be explained by increases in maternal age. PMID- 19875618 TI - Insulin glargine controversy: a tribute to the editorial team at Diabetologia. PMID- 19875620 TI - Novel insights into the etiology of diabetes from genome-wide association studies. PMID- 19875619 TI - Metabolomics applied to diabetes research: moving from information to knowledge. PMID- 19875621 TI - Coronary artery calcium: a clue to the enigma of tight glycemic control and cardiovascular disease? PMID- 19875622 TI - Cleavage of protein kinase D after acute hypoinsulinemia prevents excessive lipoprotein lipase-mediated cardiac triglyceride accumulation. AB - OBJECTIVE: During hypoinsulinemia, when cardiac glucose utilization is impaired, the heart rapidly adapts to using more fatty acids. One means by which this is achieved is through lipoprotein lipase (LPL). We determined the mechanisms by which the heart regulates LPL after acute hypoinsulinemia. RESEARCH DESIGN AND METHODS: We used two different doses of streptozocin (55 [D-55] and 100 [D-100] mg/kg) to induce moderate and severe hypoinsulinemia, respectively, in rats. Isolated cardiomyocytes were also used for transfection or silencing of protein kinase D (PKD) and caspase-3. RESULTS: There was substantial increase in LPL in D 55 hearts, an effect that was absent in severely hypoinsulinemic D-100 animals. Measurement of PKD, a key element involved in increasing LPL, revealed that only D-100 hearts showed an increase in proteolysis of PKD, an effect that required activation of caspase-3 together with loss of 14-3-3zeta, a binding protein that protects enzymes against degradation. In vitro, phosphomimetic PKD colocalized with LPL in the trans-golgi. PKD, when mutated to prevent its cleavage by caspase 3 and silencing of caspase-3, was able to increase LPL activity. Using a caspase inhibitor (Z-DEVD) in D-100 animals, we effectively lowered caspase-3 activity, prevented PKD cleavage, and increased LPL vesicle formation and translocation to the vascular lumen. This increase in cardiac luminal LPL was associated with a striking accumulation of cardiac triglyceride in Z-DEVD-treated D-100 rats. CONCLUSIONS After severe hypoinsulinemia, activation of caspase-3 can restrict LPL translocation to the vascular lumen. When caspase-3 is inhibited, this compensatory response is lost, leading to lipid accumulation in the heart. PMID- 19875623 TI - Follow-up study of female delinquent adolescents in a detention centre: effectiveness of psychiatric intervention as a mental health service. AB - BACKGROUND: RESULTS: of previous studies suggest that many female offenders have co-morbid psychiatric disorders, which require mental health services. However, few longitudinal studies examined subjects during incarceration or detention. This study compares depressive symptoms, abnormal eating behaviour and impulsivity before release from a detention centre and after incarceration, thereby indicating the effectiveness of psychiatric intervention in a Japanese detention centre. METHOD: Of 64 young women, 36 were followed up. Self-report measures were used to assess depression, eating behaviour and impulsivity after incarceration and one month before release. RESULT: s: Of the 36 participants, nine were diagnosed using the MINI-kids as needing mental health services. Those who received psychiatric intervention were diagnosed as having major depression and/or post-traumatic stress disorder. Significant main effects of intervention and effects of time were shown in the DSD. The EAT-26 score demonstrated the significance of the effects of time and interaction. In the BIS-11 scores, neither intervention nor time showed significant effects. CONCLUSIONS: Results of this study showed that the time course and psychiatric intervention contributed to recovery of depression and therapeutic intervention. The time course might reduce eating problems. Psychiatric intervention might be necessary for female juvenile detainees, which presents an important issue for future studies. PMID- 19875624 TI - Experience of caregiving in schizophrenia: a study from India. AB - BACKGROUND: Many studies from India have evaluated the burden of schizophrenia on caregivers. Experience of caregiving, on the contrary, is a broader concept that takes into consideration both negative and positive consequences of the disorder and is influenced by factors like social support and coping of caregivers. METHODOLOGY: Fifty caregivers of patients with diagnosis of schizophrenia were assessed on Experience of Caregiving Inventory (ECI), Coping Checklist (CCL), Social Support Questionnaire (SSQ) and General Health Questionnaire-12 (GHQ-12). Patients were assessed on Positive and Negative Syndrome Scale (PANSS). RESULTS: Maximum ECI score was seen in negative domains of handling the difficult behaviour followed by negative symptoms, loss and dependency. Significant positive correlation was seen between total positive ECI score and the level of education of patients and caregivers. Regression analysis showed that use of problem-focused coping, seeking social support as a coping strategy and education of caregivers explained 30.6% of the variance of ECI positive score. CONCLUSION: The study showed that education of caregivers, coping strategies used by the caregivers and available social support influence the final appraisal of caregiving. PMID- 19875625 TI - Children's representatives in psychiatric services: what is the outcome? AB - BACKGROUND: Psychiatric services have established children's representatives in an effort to support children of mentally ill patients. MATERIAL: Twenty two specially designated children's representatives and 19 other staff members were asked how they conceived the role of children's representatives and if those representatives had the responsibility of identifying children of mentally ill patients. DISCUSSION: Children's representatives expressed difficulty in functioning as advocates for children whose parents were being treated for mental illness. Members of the psychiatric staff, although aware their patients had children, seldom met them since they focused on the adults. CONCLUSIONS: More than one third of all patients seeking psychiatric care have children, yet children's representatives and other staff members seldom meet them. PMID- 19875626 TI - CPB-assisted aortic valve replacement in a pregnant 27-year-old with endocarditis. AB - A 27-year-old, G(3)P( 2)A(0) female with acute Staph aureus (SA) endocarditis successfully underwent CPB-assisted aortic valve replacement with a bioprosthetic aortic valve at 22 weeks' gestation. This patient's presentation of acute endocarditis complicated by septic shock, congestive heart failure, severe aortic insufficiency, multiple septic embolic events and borderline renal failure appeared on the daunting background of chronic heavy tobacco usage, hepatitis C positivity, long-term IV drug abuse and a pregnancy into its twenty-second week. Optimal treatment strategies implemented for both mother and fetus throughout the perioperative period contributed to a successful outcome for both. PMID- 19875627 TI - Immune system dysregulation during spaceflight: clinical risk for exploration class missions. PMID- 19875628 TI - Liver X receptor alpha (LXRalpha) as a therapeutic target in chronic lymphocytic leukemia (CLL). PMID- 19875629 TI - PSGL-1--the hidden player in T cell trafficking into the brain in multiple sclerosis? PMID- 19875632 TI - Association between clinical depression and endothelial function measured by forearm hyperemic reactivity. AB - OBJECTIVE: To assess associations between clinically significant depression (major depressive disorder [MDD] and minor depressive disorder [MiDD]) and endothelial function (EF), via forearm hyperemic reactivity (FHR), in patients referred for myocardial perfusion imaging. Studies have linked MDD to impaired EF, an early marker of coronary heart disease (CHD) and risk factor for cardiac events, in healthy, noncardiac patients, although no studies have assessed the MDD-EF association in patients with or at risk for CHD. METHODS: Depression was assessed, using the Primary Care Evaluation of Mental Disorders structured interview in 323 patients (n = 242 men; mean age = 59 years) with or at risk for CHD. FHR was assessed, using a dynamic nuclear imaging technique that measures the dilatory capability of the brachial artery during hyperemic challenge. The relative uptake ratio (RUR) of blood flow between hyperemic and nonhyperemic arms was used to measure FHR. RESULTS: Patients with MDD and MiDD had lower RURs (mean values = 3.31 and 3.34, respectively), indicating poorer EF than patients without depression (mean = 4.27) (F = 5.19, p < .01), irrespective of CHD status. All results were adjusted for covariates including sociodemographic, medical, biochemical, and physiological variables. CONCLUSIONS: Patients with clinical levels of depression had worse FHR than patients without depression, irrespective of CHD status and after adjusting for covariates. Data extend previous findings, suggesting that the link between clinical depression and worse CHD outcomes may be mediated by EF. PMID- 19875631 TI - History of sudden unexpected loss is associated with elevated interleukin-6 and decreased insulin-like growth factor-1 in women in an urban primary care setting. AB - OBJECTIVE: To investigate the hypothesis that a history of sudden unexpected loss including number of losses and type of loss (death due to unnatural versus natural causes) would be associated with the magnitude of dysregulation. The sudden unexpected death of a loved one confers risk of morbidity and mortality, perhaps due to dysregulation in the immune/inflammatory and endocrine systems. METHODS: Female primary care patients aged >or=40 years (n = 75) completed questionnaires, a clinical interview, and a blood draw. Interleukin (IL)-6 and insulin-like growth factor (IGF)-1 were assayed, using standard enzyme-linked immunosorbent assay protocols and anticytokine antibody pairs. RESULTS: History of sudden loss was positively associated with IL-6 (mean = 4.07 pg/mL; log(10) values, B = 0.314, p = .009) and negatively associated with IGF-1 (mean = 97.05 ng/mL; B = -0.277, p = .023). A linear relationship parsimoniously captured the association between ordered categories of lifetime loss (0, 1, 2-5, 5+) and increases in log(10) IL-6 (B = 0.107, p = .005) and decreases in IGF-1 (B = 0.116, p = .005). Adjusting for illness burden, depressive symptom severity, and obesity did not change the observed associations. The hypothesized effect of type of loss was not supported. CONCLUSIONS: These preliminary findings encourage further investigations to elucidate pathways from sudden unexpected loss to biomarker changes that increase risk for morbidity and mortality. PMID- 19875633 TI - Effect of depression treatment on chronic pain outcomes. AB - OBJECTIVE: To examine the effect of depression treatment on medical and social outcomes for individuals with chronic pain and depression. People with chronic pain and depression have worse health outcomes than those with chronic pain alone. Little is known about the effectiveness of depression treatment for this population. METHODS: Propensity score-weighted analyses, using both waves (1997 1998 and 2000-2001) of the National Survey of Alcohol, Drug, and Mental Health Problems, were used to examine the effect of a) any depression treatment and b) minimally adequate depression treatment on persistence of depression symptoms, depression severity, pain severity, overall health, mental health status, physical health status, social functioning, employment status, and number of workdays missed. Analyses were limited to those who met Composite International Diagnostic Interview Short-Form criteria for major depressive disorder, reported having at least one chronic pain condition, and completed both interviews (n = 553). RESULTS: Receiving any depression treatment was associated with higher scores on the mental component summary of the Medical Outcomes Study Short Form 12, indicating better mental health (difference = 2.65 points, p = .002) and less interference of pain on work (odds ratio = 0.57, p = .02). Among those receiving treatment, minimal adequacy of treatment was not significantly associated with better outcomes. CONCLUSIONS: Depression treatment improves mental health and reduces the effects of pain on work among those with chronic pain and depression. Understanding the effect of depression treatment on outcomes for this population is important for employers, healthcare providers treating this population, and policymakers working in this decade of pain control and research to improve care for chronic pain sufferers. PMID- 19875634 TI - Overload: impact of incident stressful events on antiretroviral medication adherence and virologic failure in a longitudinal, multisite human immunodeficiency virus cohort study. AB - OBJECTIVE: To examine the influence of incident stressful experiences on antiretroviral medication adherence and treatment outcomes. Past trauma history predicts poorer medication adherence and health outcomes. Human immunodeficiency virus (HIV)-infected individuals experience frequently traumatic and stressful events, such as sexual and physical assault, housing instability, and major financial, employment, and legal difficulties. METHODS: We measured prospectively incident stressful and traumatic events, medication adherence, and viral load over 27 months in an eight-site, five-state study. Using multivariable logistic and generalized estimating equation modeling, we assessed the impact of incident stressful events on 27-month changes in self-reported medication adherence and virologic failure (viral load = >or=400 c/mL). RESULTS: Of 474 participants on antiretroviral therapy at baseline, 289 persons were interviewed and still received treatment at 27 months. Participants experiencing the median number of incident stressful events (n = 9) had over twice the predicted odds (odds ratio = 2.32) of antiretroviral medication nonadherence at follow-up compared with those with no events. Stressful events also predicted increased odds of virologic failure during follow-up (odds ratio = 1.09 per event). CONCLUSIONS: Incident stressful events are exceedingly common in the lives of HIV-infected individuals and negatively affect antiretroviral medication adherence and treatment outcomes. Interventions to address stress and trauma are needed to improve HIV outcomes. PMID- 19875635 TI - Cortisol secretion and functional disabilities in old age: importance of using adaptive control strategies. AB - OBJECTIVES: To examine whether the use of health-related control strategies moderates the association between elevated diurnal cortisol secretion and increases in older adults' functional disabilities. METHODS: Functional disabilities of 164 older adults were assessed over 4 years by measuring participants' problems with performing activities of daily living. The main predictors included baseline levels of diurnal cortisol secretion and control strategies used to manage physical health threats. RESULTS: A large increase in functional disabilities was observed among participants who secreted elevated baseline levels of cortisol and did not use health-related control strategies. By contrast, high cortisol level was not associated with increases in functional disabilities among participants who reported using these control strategies. Among participants with low cortisol level, there was a relatively smaller increase in functional disabilities over time, and the use of control strategies was not significantly associated with changes in functional disabilities. CONCLUSIONS: The findings suggest that high cortisol level is associated with an increase in older adults' functional disabilities, but only if older adults do not engage in adaptive control strategies. PMID- 19875636 TI - Pyrogenic cytokines did not mediate a stress interview-induced hyperthermic response in a patient with psychogenic fever: a case report. AB - OBJECTIVE: To investigate if pyrogenic cytokines mediated psychological stress induced hyperthermic response in a patient with psychogenic fever. Despite many case reports on psychogenic fever, the mechanism responsible for how psychological stress increases core body temperature (Tc) in humans is not yet known. CASE PRESENTATION: A 13-year-old girl with fever (>38 degrees C) of unknown causes was referred to our department because psychogenic fever was suspected. To determine if the fever was actually induced by psychological stress, we conducted a 60-minute stress interview. Her baseline oral temperature was 36.60 degrees C and it began to increase immediately after commencement of the interview, reaching a maximum of 37.42 degrees C 20 minutes after the end of the interview. The plasma level of prostaglandin E(2) and the serum interleukin-6 level were increased 90 minutes after the interview. Serum levels of interleukin 1alpha, interleukin-1beta, and macrophage inflammatory protein-1alpha were all less than their minimum detectable level throughout the observation period. We also measured the patient's thermal preference by immersing her hands in warm (40 degrees C) and cold (20 degrees C) water. Her preference changed from cold to warm only during the increasing phase of oral temperature. CONCLUSIONS: This case report shows that a stress interview actually increased Tc in a patient with psychogenic fever. This study suggests that, although pyrogenic cytokines are not involved, the stress interview-induced increase in Tc was an active hyperthermia under the control of the brain, as is infection-induced fever. PMID- 19875637 TI - Monumental revolutions: scientific, sanitary and 'omic. PMID- 19875638 TI - The physical chemistry of self/non-self: jigsaws, transplants and fetuses. PMID- 19875639 TI - Impact of a community-based prevention marketing intervention to promote physical activity among middle-aged women. AB - A physical activity intervention applied principles of community-based participatory research, the community-based prevention marketing framework, and social cognitive theory. A nonrandomized design included women ages 35 to 54 in the southeastern United States. Women (n = 430 preprogram, n = 217 postprogram) enrolled in a 24-week behavioral intervention and were exposed to a media campaign. They were compared to cross-sectional survey samples at pre- (n = 245) and postprogram (n = 820) from the media exposed county and a no-intervention county (n = 234 pre, n = 822 post). Women in the behavioral intervention had statistically significant positive changes on physical activity minutes, walking, park and trail use, knowledge of mapped routes and exercise partner, and negative change on exercise self-efficacy. Media exposed women had statistically significant pre- to postprogram differences on knowledge of mapped routes. No intervention women had significant pre- to postprogram differences on physical activity minutes, walking, and knowledge of mapped routes. PMID- 19875640 TI - Mechanisms of amylin/leptin synergy in rodent models. AB - The present studies aimed to identify mechanisms contributing to amylin/leptin synergy in reducing body weight and adiposity. We reasoned that if amylin/leptin harnessed complementary neuronal pathways, then in the leptin-sensitive state, amylin should augment leptin signaling/binding and that in the absence of endogenous amylin, leptin signaling should be diminished. Amylin (50 microg/kg, ip) amplified low-dose leptin-stimulated (15 microg/kg, ip) phosphorylated signal transducer and activator of transcription-3 signaling within the arcuate nucleus (ARC) in lean rats. Amylin (50 microg/kg x d) or leptin (125 microg/kg x d) infusion to lean rats decreased 28-d food intake (14 and 10%, respectively), body weight (amylin by 4.3%, leptin by 4.9%), and epididymal fat (amylin by 19%, leptin by 37%). Amylin/leptin co-infusion additively decreased food intake (by 26%) and reduced body weight (by 15%) and epididymal fat (by 78%; all P < 0.05 vs. all groups) in a greater than mathematically additive manner, consistent with synergy. Amylin increased leptin binding within the ventromedial hypothalamus (VMN) by 35% and dorsomedial hypothalamus by 47% (both P < 0.05 vs. vehicle). Amylin/leptin similarly increased leptin binding in the VMN by 40% and ARC by 70% (P < 0.05 vs. vehicle). In amylin-deficient mice, hypothalamic leptin receptor mRNA expression was reduced by 50%, leptin-stimulated phosphorylated signal transducer and activator of transcription-3 within ARC and VMN was reduced by 40%, and responsiveness to leptin's (1 mg/kg x d for 28 d) weight-reducing effects was attenuated (all P < 0.05 vs. wild-type controls). We suggest that amylin/leptin's marked weight- and fat-reducing effects are due to activation of intrinsic synergistic neuronal signaling pathways and further point to the integrated neurohormonal therapeutic potential of amylin/leptin agonism in obesity. PMID- 19875642 TI - Fowler awarded National Medal of Science. PMID- 19875643 TI - Young professionals: their importance to SNM now and in the future. PMID- 19875645 TI - Targeting the alphavbeta3 integrin for small-animal PET/CT of osteolytic bone metastases. AB - This article describes the evaluation of the radiopharmaceutical (64)Cu-CB-TE2A c(RGDyK) ((64)Cu-RGD) as an imaging agent for osteolytic bone metastases and their associated inflammation by targeting of the alpha(v)beta(3) integrin on osteoclasts and the proinflammatory cells involved at the bone metastatic site. METHODS: The (64)Cu-RGD radiotracer was evaluated in the transgenic mouse expressing Tax (Tax(+)), which spontaneously develops osteolytic tumors throughout the vertebrae and hind limbs, using biodistribution studies and small animal PET/CT. Histologic analysis was also performed on Tax(+) mouse tails, using hematoxylin and eosin and tartrate-resistant acid phosphatase to confirm the presence of osteolytic bone lesions and the presence of osteoclasts, respectively. Additionally, a proof-of-principle study was conducted with a small group of Tax(+) animals presenting with osteolytic lesions. These animals were treated with the bisphosphonate zoledronic acid and imaged with (64)Cu-RGD to determine whether this radiopharmaceutical was sensitive enough to detect a response to the bisphosphonate therapy. RESULTS: Biodistribution studies using (64)Cu-RGD demonstrated that Tax(+) mice between the ages of 6 and 12 mo had a greater accumulation of activity in their tail vertebrae than did the wild-type (WT) cohort (P = 0.013). Additionally, Tax(+) mice between the ages of 6 and 12 mo had significantly more tracer activity associated with their tail vertebrae than did Tax(+) mice older than 12 mo (P = 0.003), suggesting that earlier bone metastases cause an increased recruitment of alpha(v)beta(3)-expressing cells. Small-animal PET/CT with (64)Cu-RGD was conducted on Tax(+) and WT mice. On the basis of standardized uptake value analysis, Tax(+) mice had approximately 2-fold more tail-associated activity than did WT animals (P = 0.0157). Additionally, decreases in uptake were observed in the tails of Tax(+) mice after treatment with the osteoclast inhibitor zoledronic acid, and histologic analysis of Tax(+) mouse-tail vertebrae revealed the presence of Tax(+) tumor cells, osteoclasts, and proinflammatory cells within the bone microenvironment. CONCLUSION: Together, these data suggest that (64)Cu-RGD has the potential to effectively image osteolytic bone metastases and monitor the physiologic changes in the bone metastatic microenvironment after osteoclast-inhibiting bisphosphonate therapy. PMID- 19875646 TI - Mammographic screening and risk factors for breast cancer. AB - Screening mammography can distort estimated effects in breast cancer risk models due to associations with other risk factors. Mammography information was available in the Nurses' Health Study from 1988, and 1,815 incident breast cancers were accrued through 2000 among 55,625 women with risk factor data. Logistic models were fit for screening mammography, and inverse probability weighting was used to adjust parameters in an established breast cancer risk model. Approximately 80% of women in each 2-year follow-up period had screening mammograms, which were positively associated with history of benign breast disease, family history of breast cancer, hormone therapy, alcohol use, physical activity, multivitamins, and calcium supplements, and negatively associated with postmenopause, current smoking, and body mass index. Markers of medical attention, including hypertension, high cholesterol, and osteoarthritis, were positively associated, while cardiovascular disease was negative. Inverse probability weighting led to small changes in effects of benign breast disease, family history, and hormone therapy. An apparent reduced risk associated with current smoking in unadjusted models was eliminated after weighting. Thus, several risk factors for breast cancer and cancer diagnosis are associated with mammographic screening. Adjustment for screening had some impact on breast cancer prediction in this cohort, especially for hormone therapy and smoking. PMID- 19875647 TI - Retinal straylight as a function of age and ocular biometry in healthy eyes. AB - PURPOSE: To determine the dependency of straylight on ocular biometry. METHODS: This prospective study included 518 eyes of 277 volunteers of diverse ethnic backgrounds with healthy eyes of various iris colors. The eyes had retinal straylight tested using a commercial psychophysical device. Ocular axial length and refraction were also measured with an ocular biometer and an autorefractometer, respectively. RESULTS: The measured retinal straylight was validated by comparing data with the age model described in the literature as log(s) = P(1) + log[1 + (age/65)(4)], where P(1) is the logarithm of the average straylight for the eyes of a newborn. The data agreed well with this model, although P(1) was slightly higher (0.931 vs. 0.87). When this model was subtracted from the measured straylight values, a quadratic increase was found in the function of axial length, L: log(s) = 0.931 + log[1 + (age/65)(4)] + (0.01089L(2) - 0.4820L + 5.330). A similar model was defined for the spherical equivalent refraction SE. This corresponds to an increasing amount of straylight for increasing degrees of myopia. No correlation was found with keratometry and corneal astigmatism or with iris color. CONCLUSIONS: Retinal straylight increases not only with age, but also with axial length. Further study is needed to identify the cause of this dependency. PMID- 19875648 TI - Protective effect of clusterin on blood-retinal barrier breakdown in diabetic retinopathy. AB - Purpose. To investigate whether clusterin attenuates blood-retinal barrier (BRB) breakdown in diabetic retinopathy. Methods. Mice with streptozotocin-induced diabetes and advanced glycation end product-treated human retinal microvascular endothelial cells (HRMECs) were used to determine the effect of clusterin on vascular permeability and tight junction protein expression, through perfusion of retinal vessels with FITC-bovine serum albumin, a [(3)H]sucrose permeability assay, a cell viability assay, Western blot analysis, immunocytochemistry, immunohistochemistry, and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling. Results. Up to 20 mug/mL of clusterin, which is 20 times the effective therapeutic concentration, did not affect the viability of the HRMECs. Moreover, it caused no toxicity in the retina. It effectively inhibited vascular endothelial growth factor-induced hyperpermeability in the HRMECs and the retinas. The antipermeability activity of clusterin was related to the restoration of tight junction proteins. Finally, it was shown to reduce leakage from the vessels in the diabetic retinas and to restore the expression of the tight junction proteins. Conclusions. The data suggest that clusterin, a well known antipermeability factor naturally secreted by cells, may have therapeutic potential in the treatment of diabetic BRB breakdown. PMID- 19875649 TI - A comparison of optic nerve head morphology viewed by spectral domain optical coherence tomography and by serial histology. AB - PURPOSE: To compare serial optic nerve head (ONH) histology with interpolated B scans generated from a three-dimensional (3-D) spectral domain (SD)-OCT ONH volume acquired in vivo from the same normal monkey eye. METHODS: A 15 degrees ONH SD-OCT volume was acquired in a normal monkey eye, with IOP manometrically controlled at 10 mm Hg. After perfusion fixation at 10 mm Hg, the ONH was trephined, the specimen embedded in a paraffin block, and serial sagittal sections cut at 4-mum intervals. The location of each histologic section was identified within the optic disc photograph by matching the position of the retinal vessels and of Bruch's membrane opening. By altering the angles of rotation and incidence, interpolated B-scans matching the location of the histologic sections were generated with custom software. Structures identified in the histologic sections were compared with signals identified in the matched B scans. RESULTS: Close matches between histologic sections and interpolated B scans were identified throughout the extent of the ONH. SD-OCT identified the neural canal opening as the termination of the Bruch's membrane-retinal pigment complex and border tissue as the innermost termination of the choroidal signal. The anterior lamina cribrosa and its continuity with the prelaminar glial columns were also detected by SD-OCT. CONCLUSIONS: Volumetric SD-OCT imaging of the ONH generates interpolated B-scans that accurately match serial histologic sections. SD-OCT captures the anterior laminar surface, which is likely to be a key structure in the detection of early ONH damage in ocular hypertension and glaucoma. PMID- 19875650 TI - Decreased gray matter concentration in the lateral geniculate nuclei in human amblyopes. AB - PURPOSE: In a group of humans with strabismic amblyopia, the relationship was examined between the structure and function of different brain regions. Three question were addressed: (1) Is the lateral geniculate nucleus (LGN) in humans with amblyopia structurally as well as functionally abnormal? (2) Do structural anomalies in the visual cortex correlate with the previously reported cortical functional losses? (3) Is there a link between the functional anomalies in the visual cortex and any structural anomalies in the geniculate? METHODS: The structure was compared by using voxel-based morphometry (VBM) and the function by functional magnetic resonance imaging (fMRI). RESULTS: The results showed that the geniculate is structurally abnormal in humans with strabismic amblyopia. CONCLUSIONS: These findings add further weight to the role of the LGN in the cortical deficits exhibited in human strabismic amblyopes. PMID- 19875651 TI - Intraocular pressure during a very high altitude climb. AB - PURPOSE: Reports on intraocular pressure (IOP) changes at high altitudes have provided inconsistent and even conflicting RESULTS: The purpose of this study was to investigate the effect of very high altitude and different ascent profiles on IOP in relation to simultaneously occurring ophthalmic and systemic changes in a prospective study. METHODS: This prospective study involved 25 healthy mountaineers who were randomly assigned to two different ascent profiles during a medical research expedition to Mt. Muztagh Ata (7,546 m/24,751 ft). Group 1 was allotted a shorter acclimatization time before ascent than was group 2. Besides IOP, oxygen saturation (SaO(2)), acute mountain sickness symptoms (AMS-c score), and optic disc appearance were assessed. Examinations were performed at 490 m/1,607 ft, 4,497 m/14,750 ft, 5,533 m/18,148 ft, and 6,265 m/20,549 ft above sea level. RESULTS: Intraocular pressure in both groups showed small but statistically significant changes: an increase during ascent from 490 m/1,607 ft to 5,533 m/18,148 ft and then a continuous decrease during further ascent to 6,265 m/20,549 ft and on descent to 4,497 m/14,750 ft and to 490 m. Differences between groups were not significant. Multiple regression analysis (IOP-dependent variable) revealed a significant partial correlation coefficient of beta = -0.25 (P = 0.01) for SaO(2) and beta = -0.23 (P = 0.02) for acclimatization time. DISCUSSION: Hypobaric hypoxia at very high altitude leads to small but statistically significant changes in IOP that are modulated by systemic oxygen saturation. Climbs to very high altitudes seem to be safe with regard to intraocular pressure changes. PMID- 19875652 TI - Glyceraldehyde-3-phosphate dehydrogenase in retinal microvasculature: implications for the development and progression of diabetic retinopathy. AB - PURPOSE: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been hypothesized as a mediator in the activation of multiple pathways implicated in the pathogenesis of diabetic retinopathy. The objective of this study was to understand the mechanism by which high glucose inactivates GAPDH in retinal microvascular cells. METHODS: Bovine retinal endothelial cells (BRECs), transfected with GAPDH, were incubated in 20 mM glucose. The effect of the overexpression of GAPDH on its activity, apoptosis, and upstream signaling pathways, protein kinase C, and hexosamine pathways was determined. The effect of the inhibitors of nitration and ribosylation on GAPDH activity, its nuclear translocation and reversal of glucose insult was also evaluated. RESULTS: High glucose decreased GAPDH activity, expression, and nuclear translocation. Overexpression of GAPDH prevented glucose-induced inhibition of its activity, nuclear translocation, apoptosis, and activation of protein kinase C and hexosamine pathways. Inhibitors of nitration and ribosylation ameliorated glucose induced inhibition of GAPDH, and their addition during the normal glucose exposure that followed high glucose levels had a beneficial effect on GAPDH activity and the degree of nitration and ribosylation. CONCLUSIONS: In hyperglycemia, GAPDH in retinal microvascular cells is inhibited by its covalent modifications, and this activates multiple pathways implicated in the pathogenesis of diabetic retinopathy. The agents that can directly target modification of GAPDH have potential in inhibiting the development and in arresting the progression of diabetic retinopathy. PMID- 19875653 TI - Heritabilities of ocular biometrical traits in two croatian isolates with extended pedigrees. AB - PURPOSE: To assess the effects of body stature and years of education, in addition to age and sex, on six oculometric traits and to estimate the heritabilities of these quantitative traits in two Croatian cross-population studies. METHODS: Adult subjects living on the two Croatian islands of Vis and Korcula were recruited for a large epidemiologic and genetic study that included eye biometry, keratometry, and autorefraction. Effects and heritabilities were estimated by using general linear mixed models for axial length (AL), anterior chamber depth (ACD), corneal curvature (CC), corneal thickness (CT), lens thickness (LT), and spherical equivalent refraction (SER). Both cohorts were genotyped with dense SNP arrays, allowing the use of kinship coefficients derived from genotypic data (realized kinship) rather than from pedigree information (expected kinship). RESULTS: Across cohorts, body mass index (BMI) did not consistently influence any of the ocular traits adjusted for age and/or sex, whereas height and years in education (YrEd) did, explaining up to an additional 5% of the variance (in CC). CT was the trait least influenced by covariates. Estimated heritabilities in Vis and Korcula, respectively, were 84% and 52% for CC, 75% and 71% for CT, 37% and 32% for LT, 59% and 45% for ACD, 37% and 74% for AL, and 0% and 17% for SER. CONCLUSIONS: While heritabilities of CT and CC seemed uniformly high across studies of Caucasian datasets, estimates for SER varied widely and were at the lower end of the spectrum of published observations in our study. PMID- 19875654 TI - Inhibition of cell proliferation of Tenon's capsule fibroblast by S-phase kinase interacting protein 2 targeting SiRNA through increasing p27 protein level. AB - PURPOSE: Although antiproliferative drugs have been used to prevent scarring after filtration surgery in patients with glaucoma, there are complications associated with their use. In the present study, the authors investigated whether small interfering RNA (siRNA)-mediated gene silencing of Skp2 can be used to increase p27(kip1) level and inhibit cell proliferation in rabbit Tenon's capsule fibroblast (rTF). METHODS: A plasmid containing Skp2 siRNA was used to decrease the high constitutive level of Skp2 protein in rTF, which can lead to consequent degradation of p27(kip1). Cell proliferation was assayed by immunocytochemistry using antibodies against 59-bromodeoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA). Skp2 siRNA was delivered to a trabeculectomy animal model to study the effect on rTF proliferation in vivo. RESULTS: Immunocytochemistry and Western blot analysis showed a decreased level of Skp2 and an increased level of p27(kip1) in cells transfected with pSkp2 siRNA but not in vehicle transfection and uninfected cells in vitro and in vivo. MTT assay showed that cell viability significantly declined in rTF transfected with Skp2 siRNA. Skp2 siRNA-transfected cells showed significantly less BrdU- and PCNA-positive staining than control cells in vitro and in vivo. Infiltration bleb was detected in the Skp2 siRNA group 14 days after trabeculectomy. CONCLUSIONS: Skp2 siRNA inhibited cell proliferation and decreased cell viability of rTF in vivo and in vitro. These findings suggest that siRNA-mediated gene silencing of Skp2 can be a novel gene therapy to treat scarring after glaucoma surgery by the suppression of p27(kip1) downregulation. PMID- 19875655 TI - A novel nonradioactive method to evaluate vascular barrier breakdown and leakage. AB - PURPOSE: To identify a novel, sensitive, nonradioactive leakage assay that can be used in the assessment of retinal vascular permeability in rats and mice. METHODS: Breakdown of the vascular barrier was induced by vascular endothelial growth factor (VEGF), lipopolysaccharide (LPS), or diabetes. Biotinylated bovine serum albumin (bBSA) was administered as a tracer. After perfusion with lactated Ringer's solution, extravasated bBSA was detected with immunoprecipitation and Western blot analysis or sandwich ELISA. The results were then normalized against the final bBSA plasma concentration, the circulation time, and the protein concentration of the tissue. RESULTS: Six hours after VEGF injection, BRB breakdown was quantified in the injected eye and was 2.5-fold higher than in the contralateral phosphate-buffered saline (PBS)-injected eye (n = 6 rats, P < 0.01). Intravitreal LPS injection induced severe inflammation in the directly injected eye and moderate inflammation in the contralateral untreated eye. Leakage was six- and threefold higher, respectively, compared with that in the untreated control animals (n = 5 rats, P < 0.01). Nine-month diabetic rats had a threefold increase in vascular leakage compared with age-matched control animals (n = 6 retinas, P < 0.05). Twenty-four hours after intraperitoneal administration of LPS in mice, the animals showed increased vascular leakage in all tissue organs examined (retina, 1.7-fold; brain, 1.5-fold; and kidney, 1.3-fold). CONCLUSIONS: bBSA can serve as an effective alternative to the current methods used for quantitating vascular leakage and especially the blood-retinal barrier breakdown. It is reasonably easy to perform, low in cost, and adaptable to experiments in mice. PMID- 19875656 TI - Ocular component growth curves among Singaporean children with different refractive error status. AB - PURPOSE: To describe and compare ocular component growth curves among different refractive error groups in Singaporean children. METHODS: Data collected yearly in 1775 Asian children aged 6 to 10 years with at least three visits were analyzed. Cycloplegic refractive error and biometry variables were measured by autorefractor and A-scan ultrasound machine. Growth curves were compared between five groups: persistent hyperopia of spherical equivalent (SE) > +1.00 D, emmetropizing hyperopia of SE > +1.00 D on the first visit and between -0.50 D and +1.00 D subsequently, persistent emmetropia of SE between -0.50 D and +1.00 D, incident myopia of SE 0.05 versus baseline). In group 3, NP increased IOP from 16.6 +/- 0.7 to 20.0 +/- 0.9 mm Hg (P < 0.01) but did not alter aqueous flow (2.65 +/- 0.3 vs. 3.0 +/- 0.3 microL/min, P > 0.05). CONCLUSIONS: Because a topical NO donor raises EVP and a topical NO synthase inhibitor lowers EVP, the authors conclude that EVP is modulated by NO. PMID- 19875658 TI - Mouse experimental myopia has features of primate myopia. AB - PURPOSE: Several recent studies have suggested that experimental myopia can be induced in mice. However, it is not clear what role the photopic visual input plays in this process and whether mouse myopia is similar to human myopia. The purpose of this study was to carry out an in vivo high-resolution analysis of changes in ocular components and refractive state of the eye upon induction of experimental myopia in mice. METHODS: A high-resolution small animal MRI system and a high-resolution automated eccentric infrared photorefractor were used to analyze changes of the refractive state and ocular components in C57BL/6J mice associated with experimental myopia induced by diffusers and -25 D lenses under photopic conditions. RESULTS: The authors found that both diffusers and -25 D lenses induce myopia in C57BL/6J mice under photopic conditions (continuous light, 200 +/- 15 lux). The extent of myopic shift induced by -25 D lenses was greater than the shift induced by diffusers (-15.2 +/- 0.7 D, lenses; -12.0 +/- 1.4 D, diffusers). Myopia in mice is attributed to an increase in size of the postequatorial segment of the eye. Experimental myopia in mice can be induced only during the susceptible period in postnatal development, which ends around postnatal day 67. CONCLUSIONS: Both diffusers and spectacle lenses induce myopia in mice under photopic conditions, during the susceptible period in postnatal development. Myopia in mice is associated with elongation of the vitreous chamber of the eye, as in humans and nonhuman primates. PMID- 19875659 TI - Spatiotemporal characterization of optic nerve degeneration after chronic hypoperfusion in the rat. AB - PURPOSE: Permanent, bilateral occlusion of the common carotid arteries (2VO) is an established model of chronic hypoperfusion. Previous studies have noted the vulnerability of the optic nerve (ON) to 2VO; however, little information is available regarding the spatiotemporal pattern of axonal degeneration and the accompanying glial cell responses. The present study was conducted to investigate these topics. METHODS: At various times after surgery, ONs were removed for mRNA or Western blot analysis or to be processed for histology and immunohistochemistry. RESULTS: 2VO precipitated an infarct within the proximal ON, whereas the retinal ganglion cells, unmyelinated axons of the optic nerve head, and the distal portion of the ON were initially preserved. The onset of degeneration was rapid, with disturbances in fast axonal transport occurring by 6 hours, damage to the axonal cytoskeleton in the proximal ON detectable by 24 hours, and complete axonal loss within the infarcted area manifest within 3 days. Wallerian degeneration of the distal segment of the ON proceeded thereafter, with almost complete loss of the ON axonal cytoskeleton evident by 30 days. Degradation of the axonal cytoskeleton was accompanied by increasing microglial activation and proliferation and a delayed infiltration of macrophages into the lesion site. Robust and persistent upregulation of stress proteins by astrocytes and oligodendrocytes, which correlated with axonal damage, was found throughout the ON after 2VO. Extracellular matrix remodeling was evident in the optic nerve head and proximal ON. CONCLUSIONS: 2VO causes rapid degeneration of the ON, with some similarity to rodent ischemic optic neuropathy. PMID- 19875660 TI - Primary care provider views of the current referral-to-eye-care process: focus group results. AB - Purpose. To understand the barriers facing primary care providers (PCPs), including nurse practitioners (NPs) and physician assistants (PAs), in the current referral-to-eye-care process and to solicit suggestions from PCPs on how to improve the current referral system. Methods. Four focus groups were conducted with a total of 17 PCPs: two groups with physicians (MDs): one in a rural setting and one in an academic medical center setting and one group of NPs and one of PAs, both in an academic setting. All discussions were audiotaped and transcribed, and both authors performed content analysis of the transcripts with the assistance of qualitative software. Results. The most frequently cited referral barriers included: (1) poor communication from eye care providers (ECPs), (2) patients' lack of finances/insurance coverage, and (3) difficulty in scheduling an eye care appointment. Suggestions made in all groups on ways to improve the current referral system included (1) implementing electronic medical records (EMRs), (2) receiving better communication/feedback from ECPs, (3) having ophthalmologists hold clinic days in primary care facilities, and (4) performing retinal scans in primary care clinics. We found few differences between the opinions of MDs and those of NPs and PAs. Conclusions. PCPs desire change(s) in the current referral-to-eye-care system. Better communication between PCPs and ECPs, further implementation of EMRs, and increasing eye screening in primary care clinics were common themes. Implementing specific suggestions, such as modernizing medical record systems, may help to increase eye care utilization among patients at high risk for advancing eye disease and vision loss. PMID- 19875661 TI - The vasodilatory effect of juxta-arteriolar microinjection of endothelinA receptor inhibitor in healthy and acute branch retinal vein occlusion minipig retinas. AB - Purpose. To investigate the effect of the endothelin(A) receptor inhibitor BQ-123 on the retinal arteriolar vasculature in minipig retinas in normal eyes and eyes with acute branch retinal vein occlusion (BRVO). Methods. Seven healthy eyes of seven minipigs and six eyes of six minipigs with experimental BRVO were evaluated under systemic anesthesia. An intravitreal juxta-arteriolar microinjection of 30 microL BQ-123 0.61 microg/mL (pH 7.4) was performed in all but one eye from each group, into which the physiologic saline vehicle alone was injected. Vessel diameter changes were measured with a retinal vessel analyzer. Results. In healthy minipig retinas (n = 6), arteriolar diameter (+/-SD) increased 6.19% +/- 3.55% (P < 0.05), 25.98% +/- 2.37% (P < 0.001), 23.65% +/- 1.2% (P < 0.001), and 16.84% +/- 1.95% (P < 0.001), at 1, 5, 10, and 15 minutes, respectively, after BQ 123 microinjection. Two hours after experimental BRVO (n = 5), the retinal arteriolar diameter had decreased (13.07% +/- 5.7%; P < 0.01). One, 5, 10, and 15 minutes after BQ-123 microinjection, retinal arteriolar diameter had increased by 7.14% +/- 3.3% (P < 0.01), 26.74% +/- 7.63% (P < 0.001), 23.67% +/- 6.4% (P < 0.001), and 16.09% +/- 3.41% (P < 0.001), respectively. Vehicle only injection had no vasoactive effect on physiologic or BRVO retinas. Conclusions. A significant increase in retinal arteriolar diameter was demonstrated after juxta arteriolar BQ-123 microinjection in healthy and in acute BRVO minipig retinas. The results suggest a role for endothelin-1 in maintaining retinal basal arteriolar tone. Reversing the BRVO-related vasoconstriction by juxta-arteriolar BQ-123 microinjection could bring a new perspective to the management of BRVO. PMID- 19875662 TI - Posttranslational modifications of the bovine lens beaded filament proteins filensin and CP49. AB - PURPOSE: The lens beaded filament proteins filensin and CP49 are phosphorylated proteins that undergo proteolytic degradation with fiber cell age; however, the specific sites of modifications remain largely unknown. The purpose of this study was to identify posttranslational modifications (PTMs) in bovine lens beaded filament proteins. METHODS: Filensin and CP49 were enriched by urea extraction of lens fiber cell homogenates after the water-soluble fraction was removed. The urea-soluble fraction was separated by SDS-PAGE, and the corresponding filensin and CP49 bands were digested by trypsin, Lys C, or Glu C. The enzymatic digests were analyzed by HPLC mass spectrometry. RESULTS: The sequences of lens beaded filament proteins were systematically mapped, and putative database sequence errors of filensin were identified. The data also indicated that Met-1 of CP49 was removed and Ser2 was acetylated. Nine phosphorylation sites on filensin and seven phosphorylation sites on CP49 were identified. Filensin was found to be truncated at D431 and L39, and the resulting new N termini were N-myristoylated and N-acetylated, respectively. Truncation of CP49 occurred at D37. Aspartic acid isomerization to isoaspartic acid occurs at the major truncation sites of filensin (D431) and of CP49 (D37). CONCLUSIONS: This study identified sites of phosphorylation and truncation in filensin and CP49 and revealed two unusual PTMs: postproteolytic N-acetylation and N-myristoylation of filensin. The detailed knowledge about these PTMs provides important information for further study of their functional consequences-for example protein redistribution during lens fiber cell differentiation and aging. PMID- 19875663 TI - The effect of hyperglycemia on hypoperfusion-induced injury. AB - Purpose. Because of differences in energy metabolism between the brain and retina, the hypothesis for the study was that, in a model of ocular and cerebral hypoperfusion, the retina would be protected by short-term hyperglycemia, whereas brain injury would be exacerbated. Methods. Hyperglycemia was induced by intraperitoneal streptozotocin. An initial experiment determined the effect of hyperglycemia alone in sham-surgery rats. Simultaneous retinal and cerebral hypoperfusion was achieved by two-vessel occlusion (2VO; permanent ligation of both common carotid arteries). Hyperglycemia was induced 3 days before 2VO by streptozotocin injection. The rats were killed 7 days after 2VO or sham surgery. The retina of one eye was collected for histology/immunohistochemistry and the fellow retina was collected for real-time RT-PCR. The retinas were analyzed for neuronal and glial markers and heat shock protein-27. The brains were processed for histology and immunohistochemistry. Results. Short-term (approximately 10 days) hyperglycemia alone caused no discernible injury to the retina. The retinas of the normoglycemic 2VO animals showed a marked loss of retinal ganglion cells and horizontal cells, thinning of the inner retina, glial cell activation, and infiltration of macrophages. The hyperglycemic 2VO rats displayed remarkable protection of the retinal structure and reduced glial cell activation compared with the normoglycemic 2VO animals. There was a significantly greater number of heat shock protein-27-positive retinal ganglion cells in the normoglycemic animals than in the hyperglycemic ones. Brains of both the normoglycemic and hyperglycemic 2VO animals displayed scattered ischemic infarcts and mild white matter injury. Conclusions. Short-term hyperglycemia affords robust protection against retinal hypoperfusion injury, but in the same animals, brain injury is not ameliorated. The mechanism of this retinal hyperglycemia-induced neuroprotection requires further study. PMID- 19875664 TI - A murine model of contact lens-associated fusarium keratitis. AB - PURPOSE: Fusarium solani and F. oxysporum were the causative organisms of the 2005/2006 outbreak of contact lens-associated fungal keratitis in the United States. The present study was an investigation of the ability of F. oxysporum grown as a biofilm on silicone hydrogel contact lenses to induce keratitis. METHODS: A clinical isolate of F. oxysporum was grown as a biofilm on lotrafilcon A contact lenses, and a 2-mm diameter punch was placed on the abraded corneal epithelium of either untreated or cyclophosphamide-treated C57BL/6 mice or of IL 1R1(-/-), MyD88(-/-), TLR2(-/-), or TLR4(-/-) mice. After 2 hours, the lens was removed, and corneal opacification, colony forming units (CFUs), and histopathology were evaluated. RESULTS: C57BL/6 mice developed severe corneal opacification within 24 hours and resolved after four days. In contrast, corneal opacification progressed in cyclophosphamide-treated mice, and was associated with unimpaired fungal growth in the cornea, and with hyphae penetrating into the anterior chamber. The phenotype of MyD88(-/-) and IL-1R(-/-) mice was similar to that of cyclophosphamide-treated animals, with significantly impaired cellular infiltration and fungal clearance. Although TLR4(-/-) mice developed a cellular infiltrate and corneal opacification similar to C57BL/6 mice, the CFU count was significantly and consistently higher. CONCLUSIONS: Fusarium grown as a biofilm on silicone hydrogel contact lenses can induce keratitis on injured corneas, with disease severity and fungal killing dependent on the innate immune response, including IL-1R1, MyD88, and TLR4. PMID- 19875665 TI - Nanoscale topography-induced modulation of fundamental cell behaviors of rabbit corneal keratocytes, fibroblasts, and myofibroblasts. AB - PURPOSE: Keratocyte-to-myofibroblast differentiation is a key factor in corneal wound healing. The purpose of this study was to determine the influence of environmental nanoscale topography on keratocyte, fibroblast, and myofibroblast cell behavior. METHODS: Primary rabbit corneal keratocytes, fibroblasts, and myofibroblasts were seeded onto planar polyurethane surfaces with six patterned areas, composed of anisotropically ordered grooves and ridges with a 400-, 800-, 1200-, 1600-, 2000-, and 4000-nm pitch (pitch = groove + ridge width). After 24 hours cells were fixed, stained, imaged, and analyzed for cell shape and orientation. For migration studies, cells on each patterned surface were imaged every 10 minutes for 12 hours, and individual cell trajectories and migration rates were calculated. RESULTS: Keratocytes, fibroblasts, and myofibroblasts aligned and elongated to pitch sizes larger than 1000 nm. A lower limit to the topographic feature sizes that the cells responded to was identified for all three phenotypes, with a transition zone around the 800- to 1200-nm pitch size. Fibroblasts and myofibroblasts migrated parallel to surface ridges larger than 1000 nm but lacked directional guidance on submicron and nanoscale topographic features and on planar surfaces. Keratocytes remained essentially immobile. CONCLUSIONS: Corneal stromal cells elongated, aligned, and migrated, differentially guided by substratum topographic features. All cell types failed to respond to topographic features approximating the dimensions of individual stromal fibers. These findings contribute to our understanding of corneal stromal cell biology in health and disease and their interaction with biomaterials and their native extracellular matrix. PMID- 19875666 TI - Pharmacokinetics of bevacizumab and its effect on vascular endothelial growth factor after intravitreal injection of bevacizumab in macaque eyes. AB - PURPOSE: To evaluate the pharmacokinetics of intravitreally injected bevacizumab in the systemic circulation and the aqueous humor and its effect on vascular endothelial growth factor (VEGF) in the aqueous humor. METHODS: Bevacizumab (1.25 mg/50 microL) was injected into the vitreous cavity of the right eyes of three cynomolgus macaques. Aqueous humor and serum were obtained from the macaques just before injection and on days 1, 3, and 7 and weeks 2, 4, 6, and 8 after injection. The bevacizumab and VEGF concentrations were measured using enzyme linked immunosorbent assay. RESULTS: Aqueous VEGF concentrations ranged from 63.2 to 106 pg/mL (mean, 80.0 +/- 22.6 pg/mL) before injection; decreased to <31.2 pg/mL, the lower limit of detection, in all eyes between 1 and 28 days after injection; and returned to the preinjection concentration at 42 days. Aqueous VEGF concentrations in the fellow eyes did not change throughout the experiment. Aqueous bevacizumab concentrations in the treated eyes reached a mean peak concentration of 49,500 +/- 10,900 ng/mL the day after injection and gradually declined, whereas those in the untreated eyes peaked at 3 days, with a mean concentration of 18.5 +/- 25.5 ng/mL, and declined to below 0.156 ng/mL, the limit of detection at 2 weeks. A maximum mean bevacizumab concentration of 1430 +/- 186 ng/mL was achieved in the serum 1 week after injection. CONCLUSIONS: Intravitreal injection of bevacizumab decreased the VEGF concentration in the treated eyes for at least 4 weeks and had no or a minimal effect on the untreated fellow eyes. PMID- 19875667 TI - Effects on choroidal neovascularization after anti-VEGF Upload using intravitreal ranibizumab, as determined by spectral domain-optical coherence tomography. AB - PURPOSE: It is unclear whether anti-VEGF monotherapy in age-related macular degeneration (AMD) achieves morphologic CNV regression or only stops further CNV growth. In this study, spectral domain-optical coherence tomography (SD-OCT) was used to image CNV structure before and after anti-VEGF treatment. METHODS: Out of 107 consecutive patients, a prospective CNV evaluation was possible in 78 of them. Newly diagnosed CNV (classic CNV: n = 16; occult CNV: n = 54; minimal classic CNV: n = 8) due to AMD was imaged before and 4 weeks after anti-VEGF upload in three intravitreal injections of ranibizumab. Qualitative (structural changes) and quantitative measurements (diameter and thickness) of the CNV were obtained from the OCT images. RESULTS: Classic CNV components were observed above the RPE/photoreceptor complex, whereas occult CNVs stayed below. Of all postoperative OCTs, 59% revealed complete dry retinal structures, 27% showed reduced edema, and 14% showed edema remaining unchanged. Mean macular thickness decreased significantly from 427 to 303 microm (P = 0.000). Qualitatively, overall CNV architecture appeared to be unchanged in 78%, was reduced in thickness in 18%, and became larger in 4%. Quantitatively, in all CNV subtypes, the diameter of the CNV lesions (preoperative, 2813 microm; postoperative, 2804 microm) did not change after treatment (classic CNV: P = 0.390; occult CNV: P = 0.405, minimal classic CNV: P = 0.092) independent of postoperative retinal edema. The overall thickness of the lesion, however, was reduced from 205 to 175 microm (P = 0.000). Thickness reduction was significantly enhanced especially in CNV with classic components (n = 24; 252 to 197 microm; P = 0.000; reduction, 22%), whereas reduction was smaller but also significant in occult CNV (183 to 164 microm; P = 0.003; reduction, 10%). CONCLUSIONS: With SD-OCT, CNV size can be two-dimensionally determined and followed up after intravitreal anti-VEGF treatment. In only 4% of CNV was enlargement observed, whereas in 78%, CNV architecture appeared qualitatively unchanged, independent of retinal edema. Quantitative measurements underlined stable CNV diameters for all subtypes but revealed significant reduction of thickness especially for classic CNV components. In this series, ranibizumab monotherapy was able to morphologically stop further CNV growth but, in most patients, did not lead to a major regression of CNV, especially of its occult components. PMID- 19875669 TI - Neurotrophic effect of a novel TrkB agonist on retinal ganglion cells. AB - PURPOSE: Retinal ganglion cells (RGCs) die in glaucoma and virtually all optic neuropathies. Recently, novel tropomyosin-related kinase B (TrkB) monoclonal antibodies have been shown to activate TrkB receptors and exert neuroprotective and neurotrophic effects. In the present study, the authors examined the ability of one of them, 29D7, to elicit RGC survival and neurite growth both in culture and in vivo. METHODS: RGCs from postnatal day (P)3 to P4 Sprague-Dawley rats were isolated by sequential immunopanning using a monoclonal antibody to Thy1. RGCs were cultured in serum-free defined medium in 96-well plates. RGC viability was assessed after 1 to 3 days by MTT assay. Activation of TrkB and downstream signaling molecules was confirmed by Western blot analysis. Intravitreal injections of 29D7 were performed after optic nerve axotomy, and subsequent RGC survival was quantified using beta-III tubulin immunostaining. Regeneration was assessed using retrograde fluorogold tracing in an optic nerve-peripheral nerve graft model. RESULTS: Similar to brain-derived neurotrophic factor (BDNF), the 29D7 antibody strongly promoted RGC survival and neurite growth in vitro compared with medium alone or control IgG. Forskolin, which weakly supported RGC survival on its own, potentiated the effect of 29D7. Intravitreal injection of 29D7 enhanced RGC survival but not regeneration in vivo 2 weeks after optic nerve injury. CONCLUSIONS: Together, these findings demonstrate the potential for antibody-mediated TrkB agonism as a potential therapeutic approach to enhance RGC survival after optic nerve injury. Further studies are needed to elucidate the mechanistic differences between this TrkB agonist and BDNF. PMID- 19875670 TI - Replication of a glaucoma candidate gene on 5q22.1 for intraocular pressure in mongolian populations: the GENDISCAN Project. AB - PURPOSE: Glaucoma is the second most frequent cause of visual impairment worldwide. Elevated intraocular pressure (IOP) causes glaucomatous optic nerve damage, especially in the primary open-angle glaucoma (POAG) subtype. As most previous studies on IOP genetics were analyses of glaucomatous families, a study of general pedigrees will provide additional information on genetic etiology. METHODS: This work was part of the GENDISCAN study (Gene Discovery for Complex Traits in Isolated Large Families of Asians of the Northeast), which recruited families from population isolates in Mongolia. IOP (obtained by a noncontact method), epidemiologic, and clinical information were collected from 1451 healthy individuals of 142 families. From these individuals, 390 genome-wide short tandem repeat markers were genotyped. Variance component-based linkage analysis was applied to pursue candidate loci explaining IOP variation. RESULTS: The mean IOP was 13.6 mm Hg in the men and 13.7 mm Hg in the women, inversely associated with aging (beta = -0.05; P