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71.
Syncytia or multinucleated giant-cell formation is one of the major cytopathic effects induced by human immunodeficiency virus (HIV) infection. Cell fusion results from the strong interaction of CD4 molecules on the surface of the uninfected T cells and gp120, an external envelope glycoprotein of HIV on the infected T cells. We studied the production of HIV in fusion cells between MOLT-4 and virus-infected MOLT-4/HIV cells and found that HIV production was enhanced up to three- to fivefold, which showed a good correlation with the appearance and extent of syncytia formation. Blocking the fusion by monoclonal antibody against a binding epitope of CD4 molecule to gp120 decreased the HIV production significantly. Enhancement of HIV production was observed by more than five-fold in comparison with chronically infected cells, which were fusion free 20 hr postcocultivation. Electron microscopic observation also showed the presence of abundant HIV particles inside the fused cells and on the outer surface. AZT blocked the HIV augmentation of fused cells in coculture completely. Southern blot analysis revealed that both integrated and unintegrated HIV DNA were highly accumulated in fusion cells, as compared with fusion-free MOLT-4/HIV cells. Among unintegrated DNA, circular and linear DNA were accumulated to a similar degree. Northern blot hybridization showed that rapid enhancement of all three species of HIV-specific RNA containing genomic (9.2 kb) and subgenomic (4.3 and 1.9 kb) RNAs were found 20 hr postinfection in fusion cells. These data suggest that syncytia formation is an extremely active infection process of HIV, by which multiple rounds of reinfection might take place.  相似文献   
72.
73.
Summary Results of DNA study on two patients of gonadal dysgenesis with a 45,X/46,X,Ynf (non-fluorescent Y chromosome) karyotype are described. In one patient who developed gonadoblastoma, all 12 loci on the non-fluorescent part of Yq were detected. Another patient did not have gonadoblastoma at 20 years, and only the proximal 6 loci out of 12 were detected.  相似文献   
74.
采用聚合酶链反应(PCR)技术,对42例肝活切组织石蜡切片中乙型肝炎病毒(HBV)DNA进行检测,并与乙肝表面抗原(HBsAg)的免疫组织化学及血清学检测进行比较,HBV-PCR阳性率为73.8%,高于组织及血清HBsAg阳性率(分别为59.5%和50.0%)。3例病理形态呈肝炎改变,而血清HBsAg(─)的肝组织中有2例检出HBV-DNA,提示PCR的高度敏感性和准确性。83.3%的门脉性肝硬变和87.5%的肝细胞癌组织中HBV-PCR呈阳性,进一步证实了上述两病与HBV的关系密切。我们还发现肝细胞淤胆患者HBV感染率较高,HBV-DNA及组织HBsAg阳性比例各为6/9和4/8。  相似文献   
75.
Assessment of HBV persistent infection in an adult population in Taiwan   总被引:1,自引:0,他引:1  
In order to study the prevalence of hepatitis B virus (HBV) in the adult population of Taiwan, we screened for the presence of HBV DNA in 205 blood samples from adult (20-59-year-old) volunteers. According to the serological markers of HBV, samples were divided into three groups: group I (173 subjects) was negative for both HBsAg and HBeAg; group II (14 subjects) was positive for both HBsAg and HBeAg; and group III consisted of 18 subjects who were HBsAg-positive but HBeAg-negative. Plasma HBV DNA was not detected in group I, but it was found in 85.7% and 11.8% of samples in group II and group III, respectively. A free-form HBV DNA was found in 14.3% of the leukocyte samples in group II. Furthermore, an integrated form of HBV DNA was detected in the leukocytes of two cases of group I who remained healthy based on clinical data. HBV DNA was also detected in the spermatozoa and liver cells of one of the cases.  相似文献   
76.
Distress and DNA repair in human lymphocytes   总被引:3,自引:0,他引:3  
This research assessed differences in DNA repair in lymphocytes from high-and low-distressed individuals. A median split on Minnesota Multiphasic Personality Inventory (MMPI) Scale 2 divided 28 newly admitted nonpsychotic psychiatric inpatients into high- and low-distress subgroups. The high-distress subgroup had significantly poorer DNA repair in lymphocytes exposed to X-irradiation than low-distress subjects. We also found that lymphocytes obtained from this psychiatric sample had significantly poorer DNA repair than lymphocytes from nonpsychiatric control subjects when compared 5 hr after X-irradiation. A high level of distress therefore appears to be associated with significant dysfunctional differences at the molecular level which may have important implications for health. These data provide evidence for a direct pathway through which distress could influence the incidence of cancer.This research was funded in part by General Molecular Applications, Inc., the Bremer Foundation, the Samuel J. Roessler Fund, and Comprehensive Cancer Center Core Grant CA-16068-09.  相似文献   
77.
78.
Summary The growth and vascularization patterns of B16 melanoma colonies in the liver and lungs were measured and compared by histological techniques and dye diffusion patterns after injection of the fluorochrome Hoechst 33342. In the liver, the fluorescent pattern of dye diffusion revealed that uninodular tumours measuring up to 146 n in diameter were not functionally vascularized. However, when the nodules fused to give rise to multinodular tumours measuring between 256 and 366 n in diameter, a reticular dye diffusion pattern revealed functional tumour vascularization. In the lungs, subpleural, parenchymal and peritubular (i.e. surrounding blood vessels and airways) tumours were observed. The two former classes were vascularized down to thicknesses and diameters of 49 and 24 m respectively. In contrast, dye diffusion was never seen in peritubular tumour cuffs up to 609 m in thickness. The results indicate differences in vascularization patterns in B16 tumours in the liver and lungs, and differences between tumours growing in different sites within the lungs. If these results are applicable to metastases in these two organs, they indicate potential diffusion-mediated resistance to chemotherapy, and potential hypoxia-mediated resistance to radiotherapy of both metastases and micrometastases.  相似文献   
79.
An Epstein-Barr virus (EBV)-producer line, designated Akata, was established from a Japanese patient with Burkitt's lymphoma. The Akata line possessed the Burkitt's-type chromosome translocation, t(8q-; 14q+), and was derived from the tumor cell. Akata cells produced a large quantity of transforming virus upon treatment of cells with anti-immunoglobulin antibodies (Takada, 1984). Southern blot analysis of viral DNA indicated that the Akata EBV is nondefective and more representative of wild-type viruses. Akata cells should be useful as a source of EBV.  相似文献   
80.
Human cytomegalovirus (HCMV) DNA can be detected in different compartments of human milk. A protocol for the preparation of milk whey free of fat and cells for the detection of human cytomegalovirus (HCMV) by nested PCR is presented. This is based upon the experience of the separation of more than 200 milk specimens of healthy seropositive breast feeding mothers. HCMV DNA could be detected in freshly centrifuged and filtrated milk whey specimens without contamination by cellular DNA. In limiting dilution experiments using HCMV plasmid DNA, the effect of different DNA extraction procedures from native milk and milk whey on the detection limit of cytomegaloviral DNA was demonstrated. About 200 viral genome equivalents/ml in milk whey or native milk were detectable by classical organic phenol/chloroform extraction or a spin column method, respectively. The detection of viral DNA in milk cells depended on a minimum number of milk cells (105–2×105) available for DNA extraction. In contrast to the findings of cytomegaloviral DNA in native sera or plasma of immunosuppressed patients we failed to amplify low level viral DNA from native breast milk by nested PCR due to an inhibition of Taq polymerase by lipid components. Finally, the course of cell associated and cell free DNAlactia was monitored. Analyzing sequential milk specimens, in some cases the presence of HCMV DNA in colostrum could be demonstrated. DNAlactia of milk cells and whey was partially discordant. Onset (week 1–4 after delivery) and duration (2 weeks up to more than 3 months) of DNAlactia showed distinct individual patterns. The methods described, allow further analysis of the mechanisms involved in the postnatal HCMV transmission by breast feeding seropositive mothers.  相似文献   
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