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291.
Polypeptides released into the culture medium of herpesvirus sylvilagus-infected cells were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracellular fluid from [35S]methionine- and [3H]glucosamine-labeled cell cultures. Virus-induced glycoproteins 31, 32, and 33 (molecular weights of 62,000, 59,000, and 54,000, respectively) were the most abundant species and appeared predominantly in the culture medium. This observation, together with the known cell-associated nature of herpesvirus sylvilagus, suggested that virus-induced glycoproteins 31, 32, and 33 were specifically released. Immunization of rabbits with virus-induced glycoproteins 13 (molecular weight of 130,000) and 32 resulted in the production of antibodies that neutralized viral infectivity in vitro. Both antiserum to gp13 and antiserum to gp32 immunoprecipitated gp13, gp26, gp33a, gp45, and virus-induced polypeptide 39 (molecular weights of 130,000, 77,000, 49,000, 27,000, and 36,000, respectively) from [35S]methionine-labeled cell extracts as well as virus-induced glycoproteins 31, 32, and 33 from the culture medium. In addition, membrane immunofluorescence assays indicate that an antigen(s) reactive with anti-gp13/32 serum was located on the plasma membrane of infected cells.  相似文献   
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These siblings of a Czech family aged 21, 19 and 6 years, respectively, with congenital dyserythropoietic anemia, type II, (HEMPAS) are reported. In two elder siblings ferrokinetic studies revealed a rapid plasma 59Fe clearance, markedly decreased erythrocyte incorporation and shortened 51Cr red-cell survival. Direct anti-globulin test was found positive in one of them. Further investigations revealed low values of blood plasma cholesterol, total lipids, beta-lipoproteins, beta-carotine and vitamin E and A as well as low values of the prothrombin complex. Liver biopsy demonstrated siderosis and disseminated intravascular coagulation in the liver in both patients. The possible reasons for these humoral aberrations are discussed.  相似文献   
294.
The interpretation of a moving retinal image   总被引:10,自引:0,他引:10  
It is shown that from a monocular view of a rigid, textured, curved surface it is possible, in principle, to determine the gradient of the surface at any point, and the motion of the eye relative to it, from the velocity field of the changing retinal image, and its first and second spatial derivatives. The relevant equations are redundant, thus providing a test of the rigidity assumption. They involve, among other observable quantities, the components of shear of the retinal velocity field, suggesting that the visual system may possess specialized channels for computing these components.  相似文献   
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297.
The physical and covalent binding of the carcinogen benzo(a)pyrene-7,8-diol-9,10-oxide (BaPDE) to poly(dG-dC).(dG-dC) and poly(dG-m5dC).(dG-m5dC) in the B and Z forms were studied utilizing absorbance, fluorescence and linear dichroism techniques. In the case of poly(dG-dC).(dG-dC) the decrease in the covalent binding of BaPDE with increasing NaCl concentration (0.1-4 M) as the B form is transformed to the Z form is attributed to the effects of high ionic strengths on the reactivity and physical binding of BaPDE to the polynucleotides; these effects tend to obscure differences in reactivities with the B and Z forms of the nucleic acids. In the case of poly(dG-m5dC).(dG-m5dC) the B-to-Z transition is induced at low ionic strength (2 mM NaCl + 10 microM Co(NH3)6Cl3) and the covalent binding is found to be 2-3-times lower to the Z form than to the B form. Physical binding of BaPDE by intercalation, which precedes the covalent binding reaction, is significantly lower in the Z form than in the B form, thus accounting, in part, for the lower covalent binding. The linear dichroism characteristics of BaPDE covalently bound to the Z and B forms of poly(dG-m5dC).(dG-m5dC) are consistent with nonintercalative, probably external conformations of the aromatic pyrenyl residues.  相似文献   
298.
Metabolic depletion of human red cells with 2-deoxy-D-glucose in the presence of EGTA decreased ATP to about 4% of the initial value and increased total ouabain- and furosemide-resistant Na+ and K+ effluxes by 20% and 100%, respectively, and furosemide-sensitive Na+ and K+ effluxes by 100% and 60%, respectively. When ATP was restored, all the components of Na+ and K+ fluxes measured returned to baseline levels suggesting a metabolic dependence.  相似文献   
299.
Lymphocyte antigens were tested in sheep which had been selected for responsiveness to vaccination against the intestinal nematode Trichostrongylus colubriformis. These sheep had been bred in an assortative mating programme which produced offspring designated as either “high responders” or “low responders”, with highly heritable resistance or susceptibility.Ovine lymphocyte antigen (OLA) typing antisera were obtained from parous ewes in the course of matings which produced the high and low responder flocks. A particular antigen (SY1) was found to be present in high frequency on the lymphocytes of high responder (72·2%) and in lower frequency (21·9%) on the lymphocytes of low responder rams. In ewes, the frequency for high responders was 65·7% and for low responders it was 33·5%. A similar association between the SY1 antigen and low faecal egg count was found in random-bred sheep which had been vaccinated with irradiated larvae and challenged with normal larvae. The conclusion was drawn that this lymphocyte antigen was likely to be part of the sheep major histocompatibility complex which influenced the immune response of sheep to vaccination against the parasite.  相似文献   
300.
Ten patients with advanced progressive adenocarcinoma of the prostate were treated with a long acting analogue of gonadotrophin releasing hormone. Eight of these patients responded to treatment in terms of pain relief and clinical regression of tumour. Serum gonadotrophin and testosterone concentrations were significantly suppressed by the end of the second week of treatment, testosterone concentrations being comparable with those achieved by castration. The two patients who failed to respond had both relapsed previously when receiving conventional treatment, and neither showed any endocrine response to the analogue. Superagonists of gonadotrophin releasing hormone may be the treatment of choice in adenocarcinoma of the prostate, but further trials are required to establish long term safety and efficacy.  相似文献   
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