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631.
The development and application of a highly sensitive double-target fluorescence in situ hybridization (FISH) method in combination with immunohistochemistry for detection of chromosome 1 abnormalities in interphase nuclei of neuroblastoma samples is reported. An alpha-satellite probe specific for chromosome 1 and a VNTR probe that hybridizes to chromosome band 1p36.3 were hybridized to GD2 prestained neuroblastoma cells in double-target FISH experiments. The ratio of intact to deleted chromosome 1 homologs in the neuroblastoma cells was assessed. To demonstrate the reliability of the method described, four selected samples derived from different neuroblastoma stages are presented. FISH results correlated well with data obtained by conventional cytogenetic procedures. The technique described allows sensitive detection of chromosome 1 abnormalities in interphase nuclei and enables partial cytogenetic analysis of nondividing cells with a defined immunological phenotype.  相似文献   
632.
Supportive evidence that apoptosis contributes to loss of CD4+ lymphocytes in human immunodeficiency virus type 1 (HIV-1)-infected humans comes from an apparent lack of abnormal apoptosis in apathogenic lentivirus infections of nonhuman primates, including HIV-1 infection of chimpanzees. Two female chimpanzees were inoculated, one cervically and the other intravenously, with HIV-1 derived from the LAI/LAV-1b strain, which was isolated from a chimpanzee infected with the virus for 8 years. Within 6 weeks of infection, both recipient chimpanzees developed a progressive loss of CD4+ T cells which correlated with persistently high viral burdens and increased levels of CD4+ T-cell apoptosis both in vitro and in vivo. Lymph nodes from both animals also revealed evidence of immune hyperactivation. Intermediate levels of T-cell apoptosis in both peripheral blood and lymph nodes were seen in a third chimpanzee that had been infected with the LAI/LAV-1b strain for 9 years; this animal has maintained depressed CD4/CD8 T-cell ratios for the last 3 years. Similar analyses of cells from 4 uninfected animals and 10 other HIV-1-infected chimpanzees without loss of CD4+ cells revealed no difference in levels of apoptosis in these two control groups. These results demonstrate a correlation between immune hyperactivation, T-cell apoptosis, and chronic loss of CD4+ T cells in HIV-1-infected chimpanzees, providing additional evidence that apoptosis is an important factor in T-cell loss in AIDS. Furthermore, the results show that some HIV-1 strains are pathogenic for chimpanzees and that this species is not inherently resistant to HIV-1-induced disease.  相似文献   
633.
Silicon - To overcome the fabrication complexity and achieve a better switching ratio is a major grave concern for applications in semiconductor devices. In this regards, a novel stack gate-oxide...  相似文献   
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