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The absence of centromeric bands in the karyotype of Felis catus is confirmed. It is also confirmed that no satellite band is visible in CsCl density gradients. However, a satellite is observed both by recentrifuging the fraction of the DNA that bands at high density in CsCl and by using netropsin to enhance the resolution of a CsCl gradient containing total F. catus DNA. The satellite, about 0.5% of total DNA, was isolated by repeated centrifugation in CsCl alone and in CsCl with netropsin. Netropsin was removed and a pure satellite DNA obtained. The reassociation kinetics (C0t1/2 less than 10(-3) M . s) show that the satellite is of the simple sequence type and hence a candidate for centromeric heterochromatin. Its cytological localisation awaits in situ hybridisation experiments. 相似文献
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OBJECTIVE: To report population reference values for blood lipids, to determine the prevalence of lipid risk factors and to assess their association with other risk factors. DESIGN: Population-based cross-sectional surveys. Survey participants were interviewed at home and provided a blood sample at a clinic. All blood lipid analyses were done in the Lipid Research Laboratory, University of Toronto. The laboratory is standardized in the National Heart, Lung Blood Institute-Centres for Disease Control Standardization Program. SETTING: Nine Canadian provinces, from 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 was selected from the health insurance registers for each province. Blood samples were obtained from 16,924 participants who had fasted 8 hours or more. OUTCOME MEASURES: Concentration of total plasma cholesterol, triglycerides and high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in blood samples from fasting participants. MAIN RESULTS: Of the study population, 46% had total plasma cholesterol levels above 5.2 mmol/L, 15% had LDL-cholesterol levels above 4.1 mmol/L, 15% had triglyceride levels above 2.3 mmol/L and 8% had HDL-cholesterol levels below 0.9 mmol/L. Total plasma cholesterol, LDL-cholesterol and triglyceride levels rose with age in men to a maximum in the 45-54 age group; in women there was little change with age up to ages 45 to 54, at which time the level of each of these lipids increased appreciably. The age-standardized prevalence of obesity was positively associated with elevation of total plasma cholesterol. CONCLUSION: The results suggest the need for a multifactorial approach in health promotion efforts to lower blood cholesterol levels and reduce other risk factors in the population. A considerable number of adults were found to be at risk at all ages in both sexes. In the short term, men aged 34 and older and women aged 45 and older might benefit most from prevention programs. 相似文献
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In vivo and in vitro reactivation impairment of a herpes simplex virus type 1 latency-associated transcript variant in a rabbit eye model. 总被引:3,自引:2,他引:1
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M D Trousdale I Steiner J G Spivack S L Deshmane S M Brown A R MacLean J H Subak-Sharpe N W Fraser 《Journal of virology》1991,65(12):6989-6993
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Multilocus recombination frequencies 总被引:8,自引:0,他引:8
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REINHARD B
SE KARL T. FRIEDHOFF SYLVIA OLBRICH 《The Journal of eukaryotic microbiology》1987,34(1):110-113
Four fallow deer, Cervus dama, became infected with Trypanosoma (Megatrypanum) sp. by oral application of triturated guts from tabanids collected in an area with deer but without any cattle; four control calves remained negative. Upon challenge with triturated guts from tabanids from an area with pastured cattle, the four calves became infected with Trypanosoma (M.) theileri. The prepatent period in deer was five days or less. Haematopota spp. and Tabanus spp. were identified as vectors of the deer trypanosomes. It is concluded that the trypanosomes of C. dama belong to a Megatrypanum species that is not identical with T. theileri. 相似文献
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Two patients with disseminated histoplasmosis are reported. One patient presented with severe thrombocytopenic purpura and splenomegaly. Histoplasmin skin test, blood and bone marrow cultures and smears, sputum cultures, and chest radiographs were negative for Histoplasma capsulatum. She died on the sixth hospital day from a massive intracerebral hemorrhage. Cardiorespiratory function was maintained until one kidney was removed for homotransplantation. The second patient, with chronic glomerulonephritis and uremia, received the renal homograft from the first patient. Initial signs of homograft rejection developed five days postoperatively. Diffuse thrombocytopenic purpura occurred shortly thereafter. Spores of Histoplasma capsulatum were observed in blood smears, in leukocyte concentrates, and in five-day leukocyte cultures from the blood obtained prior to death. Disseminated histoplasmosis was found in both patients at autopsy. The severe platelet deficit in both cases suggests that systemic histoplasmosis should be considered as a cause of thrombocytopenic purpura.To our knowledge, this is the first reported instance of direct transmission of Histoplasma capsulatum, and must be considered a hazard in homotransplantation.In vitro leukocyte cultures as a method for early diagnosis of certain disseminated fungous infections needs further investigation. 相似文献
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