动物分子流行病学的研究及其应用概况

动物分子流行病学是近年来流行病学研究中一个崭新、活跃的领域，得到了迅猛的发展．它采用分子生物学技术和理论，从分子水平上阐明疫病在畜群中分布规律和影响因素，并广泛应用于病原体的起源和进化，病原体的分型，强毒与弱毒株、疫苗免疫动物和自然感染动物的鉴别，耐药性传播扩散等方面的研究．本文拟对此作一简要概述，以展示动物分子流行病学研究中的最新进展和光辉前景     

Y-family DNA polymerases in mammalian cells

Eukaryotic genomes are replicated with high fidelity to assure the faithful transmission of genetic information from one generation to the next. The accuracy of replication relies heavily on the ability of replicative DNA polymerases to efficiently select correct nucleotides for the polymerization reaction and, using their intrinsic exonuclease activities, to excise mistakenly incorporated nucleotides. Cells also possess a variety of specialized DNA polymerases that, by a process called translesion DNA synthesis (TLS), help overcome replication blocks when unrepaired DNA lesions stall the replication machinery. This review considers the properties of the Y-family (a subset of specialized DNA polymerases) and their roles in modulating spontaneous and genotoxic-induced mutations in mammals. We also review recent insights into the molecular mechanisms that regulate PCNA monoubiquitination and DNA polymerase switching during TLS and discuss the potential of using Y-family DNA polymerases as novel targets for cancer prevention and therapy.     

335例乙型肝炎患者血清HBV-DNA定量与乙肝病毒标志物的相关性分析

目的:探讨乙型肝炎患者血清HBV-DNA定量与乙肝病毒标志物的关系。方法:对335例乙型肝炎患者分别用实时荧光定量聚合酶链反应(FQ-PCR)检测血清HBV-DNA含量,酶联免疫吸附法(ELISA)检测血清乙肝病毒标志物,并对结果进行统计学分析。结果:大三阳组HBV-DNA阳性率及含量显著高于其他组(P<0.01);小三阳组HBV-DNA阳性率及含量显著低于大三阳组(P<0.01),但与HBsAg、HBcAb阳性组比较差异无统计学意义(P>0.05);HBeAg阳性组HBV-DNA阳性率显著高于HBeAg阴性组(P<0.01)。结论:只有将HBV-DNA定量检测和乙肝病毒标志物有机的结合,才能为乙型肝炎的临床感染、病毒复制、传染性强弱以及抗病毒药物的疗效观察提供可靠的判断依据。     

优化的热启动PCR—限制性酶切法检测冠心病患者？…

改进传统的载脂蛋白Ｅ基因多态性检测方法，建立热启动聚合酶链反应－限制性片段长度多态性检测分析方法。方法：应用热启动ＰＣＲ－限制性内切酶酶切－聚丙烯酰胺凝胶电泳－固定银染法测定１５８例冠心病患者和１１６例正常对照者的ＡｐｏＥ基因型。     

Expression of human cytomegalovirus DNA polymerase in insect cells using baculovirus expression system: Purification and biochemical characterizations

Human Cytomegalovirus (HCMV) DNA polymerase gene was overexpressed in insect cells using the baculovirus transfer system. A6. 2 kb HCMV Rsr II-EcoRI DNA fragment with intact HCMV pol gene coding sequence was engineered into NheI site of vector pBlueBac under the control of polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV). Recombinant AcNPV carried HCMV pol gene was generated by cotransfection of Spodoptera frugiperta cell (SF21) with AcNPV DNA and baculovirus transfer vector with HCMV pol gene. Infection of SF21 cell with recombinant virus lead to the expression of 140 kD peptide of HCMV specific DNA polymerase at the level approximately 2 mg per 10⁸ cells. The polypeptide was purified from the infected SF21 cells by a series of column chromatography to homogeneity. The purified enzyme had a molecular weight of 140 kD and reacted with antiserum specific for HCMV DNA polymerase. It exhibited both 3′–5′ and 5′–3′ exonuclease activities. This enzyme is also sensitive to phosphono acetate. Ye Linbai: born in Feb. 1948. Professor. Current research interest is in Vitology and Molecular Biology Supported by Public Health Service Grants CA21773, CA15036 and AI12717 from the National Institutes of Health     

用微分方程组的解析解拟合甲型流感病毒聚合酶酸性蛋白家族的进化过程(英文)

用数学模型对甲型流感病毒聚合酶酸性蛋白家族的进化进行拟合:(1)用氨基酸对的可预测性量化1918年至2008年分离的2433个聚合酶酸性蛋白以表示其演变,(2)确定上升半寿期和下降半衰期是否相似作为拟合的前提条件,(3)用微分方程组的解析解拟合进化,(4)用所获得的拟合参数模拟2009年至2018年可能的进化过程。结果呈现了对聚合酶酸性蛋白家族及其不同亚型的良好拟合,这标志着蛋白质进化的研究已经从经验性的实验分析向动力学的数学建模迈进。     

猪细小病毒分子生物学诊断技术的研究进展

猪细小病毒是引起母猪繁殖障碍性疾病的主要病原之一。它广泛分布于世界各地,给我国乃至全世界的养猪业造成了巨大的经济损失。近年来,猪细小病毒的分子生物学诊断方法的研究进展迅速,为猪细小病毒的快速、准确的诊断起到了重要的作用。从聚合酶链式反应技术、核酸探针技术、DNA芯片技术等方面对猪细小病毒的分子生物学诊断技术进行综述有助于我们进一步了解这项技术。     

新生物活性肽-daintain/AIF-1在乳腺癌中的表达

采用免疫组织化学两步法分析了乳腺癌组织蜡块切片中daintain／AIF-1的表达．93％的乳腺癌中都有该活性肽的分布,癌旁良性组织中则没有阳性染色或染色很浅．Daintain／AIF-1在乳腺病变级别不同组织中的表达差异很大：增生组织免疫后着黄色,重度不典型增生组织着橙黄色,癌组织则染成了棕褐色．进一步用RT-PCR检测发现,乳腺癌新鲜组织中能扩增出daintain／AIF-1的mRNA,而癌旁良性乳腺组织中的daintain／AIF-1 mRNA极微量,几乎看不到扩增的核酸条带．这些研究表明,daintain／AIF-1在乳腺癌中过量表达,可能在乳腺肿瘤的发展过程起到了促进作用．因此,提示daintain／AIF-1可作为乳腺癌病变早期诊断的一个参考指标。