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881.
Two distinguishable subpopulations were recovered from chickens infected with lentogenic strains of Newcastle disease virus originally ioslated from chickens in Australia and Ireland. In both instances, a subpopulation that rapidly eluted from chicken erythrocytes was recovered predominantly from tracheal swabs, and a slow-eluting subpopulation from cloacal swabs. The two subpopulations differed in thermostability of the hemagglutinatin and mean survival time of infected chicken embryos, as well as in elution pattern. The heterogeneity characteristic of the Aust-V4 strain and NI-Ulster strain could not be demonstrated in B1, NJ-LaSota, and ENG-F, lentogenic strains commonly used in vaccines. The question is discussed of whether standard vaccine strains are also hetrogeneous if a technique for separating stock populations is found, and the significance of possible heterogeneity to the effectivenss of the vaccines. 相似文献
882.
S Sun RP Beasley KE Anderson HS Berg C Hsu W Lee 《Canadian Metallurgical Quarterly》1976,21(6):366-369
Liver morphology and function were restudied after an interval of 1 1/2-2 years in 21 Chinese men with hepatitis B antigen (HBsAg). Antigenemia and mild liver histopathology disappeared in one individual who developed antibody to HBsAg(Anti-HBsAg). 20 subjects who were chronic carriers of HBsAg had mild histological abnormalities which were usually persistent and were more commonly lobular than portal. Particularly striking were focal necrosis, eosinophilic bodies, ground-glass cytoplasmic change, and, by electron microscopy, microtubular structures within cytoplasmic membranous cysternae. Interval development of chronic aggressive hepatitis was observed in only one subject. This study suggests that the great majority of HBsAg carriers have a good prognosis at least over a 1 1/2-2-year period, and that liver biopsy is most indicated in those with persistent liver function abnormalities. 相似文献
883.
Levels of cefuroxime in bronchial secretion were measured in 49 patients requiring bronchoscopy for diagnostic purposes. Patients were randomly allocated to one of 4 groups which differed with respect to the size (750 mg or 1.5 g) and number (1 or 7) of intravenous doses of cefuroxime given approximately 1 hour prior to sampling. Levels of cefuroxime achieved after administration of all 4 dosages were sufficient to exceed the MIC values for the major chest pathogens. Penetration of cefuroxime into bronchial secretion was also found to be dose-related. 相似文献
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Although much has been learned about the spatial sampling and filtering properties of peripheral vision, little attention has been paid to the remarkably clear appearance of the peripheral visual field. To study the apparent sharpness of stimuli presented in the periphery, we presented Gaussian blurred horizontal edges at 8.3, 16.6, 24, 32, and 40 deg eccentricity. Observers adjusted the sharpness of a similar edge, viewed foveally, to match the appearance of the peripheral stimulus. All observers matched blurred peripheral stimuli with sharper foveal stimuli. We have called this effect "sharpness overconstancy". For field sizes of 4 deg, there was greater overconstancy at larger eccentricities. Scaling the field size of the peripheral stimuli by a cortical magnification factor produced sharpness overconstancy which was independent of eccentricity. In both cases, there was a slight sharpness underconstancy for peripherally presented edges blurred only slightly. We consider various explanations of peripheral sharpness overconstancy. 相似文献
889.
Although 30-60% of the variance in many personality traits is inherited, until recently little was known about the responsible genes. Preliminary studies of family history in bipolar disorder and of X-linkage of personality traits in color-blindness suggested a "quantitative trait locus" (QTL) approach to the genetics of normal personality. In methodically similar but independent studies of 124 Israeli and 315 American normal volunteers we showed an association between the dopamine D4 receptor gene (D4DR) and the personality trait of novelty seeking. In the Israeli sample we also found an interaction between the D4DR gene and the serotonin 2C receptor gene (5-HT2C) with a marked effect on the trait of reward dependence. Further investigation of genes for personality traits may suggest links between normal personality and psychiatric illness. 相似文献
890.
CONTEXT: Alopecia is a recognized adverse effect of numerous medications, but vaccines are not normally considered a cause for unexpected loss of hair. OBJECTIVE: To describe case reports of hair loss after routine vaccines and to assess the hypothesis that vaccinations might induce hair loss. DESIGN: Case series with telephone follow-up. METHODS: Review of spontaneous reports to the Food and Drug Administration, the Centers for Disease Control and Prevention, and the Vaccine Adverse Event Reporting System. MAIN OUTCOME MEASURE: Loss of hair following immunization. RESULTS: A total of 60 evaluable reports submitted since 1984 and coded for "alopecia" after immunizations included 16 with positive rechallenge (hair loss after vaccination on more than 1 occasion), 4 of which were definite and 12 possible or probable. Of the 60 cases, 46 had received hepatitis B vaccines. Both of the currently available recombinant products, as well as the former plasma-derived product, were represented. Females predominated in all age groups. The majority of patients recovered, but clinical features, such as intervals from vaccination until onset and the extent and reversibility of hair loss, varied widely. Nine patients reported previous medication allergy. CONCLUSION: There may be an association, probably very rare, between vaccinations and hair loss. More than 1 pathophysiologic mechanism may be responsible. Since apparently nonrandom distributions by vaccine, age, and sex could reflect biased case ascertainment, further research will be needed in defined populations with consistent case detection. 相似文献