关键词： cDNA   序列   质粒   基因载体   哺乳动物细胞   改良法   分子生物学   转染   空斑  

摘要： 用大肠杆菌HB 101株扩增了含有poliovirus sabin 1型全序列cDNA plasmid。以不同的方法进行提取 polio cDNA(sabin 1)plasmid,转染 2 BS细胞,非洲绿猴肾细胞(AGMK)。结果表明:氯化铯改良法提取之polio cDNA,保持了序列完整功能,转染细胞成功。对恢复病毒进行了生物学性质与抗原性的鉴定,结果与poliovirus sabin 1型相同。

关键词： 自来水厂   水样   二次加氯   加氯处理   脊髓灰质炎病毒   小儿麻痹病毒   肠道病毒   常规  

摘要： 本实验目的在于检查上海市自来水厂中经常规加氯处理后,在杀灭肠道病毒方面的效果。实验采集现场加氯后之水样,加上一定量脊髓灰质炎病毒Ⅰ型LSc减毒株后,每间隔一定时间测定水中总氯及游离氯含量以及脊髓灰质炎病毒的消长情况。水厂之二次加氯中以第一次加氯为水处理中杀灭病毒的主要环节,加氯后60分钟即已查不到存活之病毒。

关键词： 病毒病   检出   病毒量   病毒传染病   传染病   脊髓灰质炎病毒   小儿麻痹病毒   肠道病毒   病毒污染  

摘要： 一、病毒在环境中的分布 病毒从人体排出进入自然环境,由于水、空气、人为活动等使病毒扩散,广泛地存在于水环境、土壤、空气和食品中。 1.水环境的病毒 由于人口的集中和工业化程度的提高,人们对水资源的利用要求也随之提高了,这不可避免地要循环利用经处理过的水。而生活污水、医院污水大量排入水环境中,会造成污染。但是每人每天又必须消耗大量的水,因而水中的病毒污染问题更为紧迫地摆在人们面前。 1)污水 污水中病毒主要来自病毒病患者的粪便和分泌物。污水中病毒的含量取决于人群的结构、社会经济条件、污水的处理程度、稀释水量的大小、排出病毒的数量和性质及季节的变化等因素。卫生条件差的地区的污水中病毒含量高。相对其它水体而言,污水中病毒含量最多。1972年—1974年,Fattal从以色列海法市的市政污水中检出病毒的

关键词： 脊髓灰质炎病毒   神经末梢   罗斯   峡谷   动物   小儿麻痹病毒   肠道病毒   周围神经系统   感冒   鼻病毒  

摘要： 病毒侵害植物、动物和人。病毒之一——核糖核酸病毒能引起人从头到脚的疾病,如病毒性脑膜炎、甲型肝炎、流行性脊髓灰质炎和普通感冒。现在,感冒病毒和脊髓灰质炎病毒的三维原子结构已能确定,这两种动物病毒最近已搞清。《自然》、《科学》都在十天内宣布了这一发现,叙述了这一重要进展,即已具有预防这些和另一些能引起感染的病毒的认识,以及免疫系统怎样工作的新知识。

关键词： 乙型肝炎病毒抗原   RNA   外壳蛋白   DNA   恶性疟原虫   脊髓灰质炎病毒   小儿麻痹病毒   肠道病毒   抗原基因   疫苗生产   乙型肝炎疫苗   多聚酶   聚合酶   recA   卵转铁蛋白   编码序列   AIDS   质粒   基因载体   大肠杆菌外膜蛋白   HBsAg   逆病毒   HTLV   单克隆抗体  

摘要： 873166 通过 DNA 重组体乙型肝炎疫苗预防乙型肝炎[英]/Schalm,S.W.…//***.-1986,29(2).-42～48[译自 CBA,1986,(9),3646]综述了重组体乙型肝炎疫苗的安全性和有效性,以及通过重组 DNA 技术使之成为第一个普遍接受的疫苗的可能性。附有27篇

关键词： Poliovirus   rotavirus   children   vaccine trial  

摘要： A clinical trial was carried out in 3-month-old infants to assess whether concomitant oral administration of live polio and rotavirus RIT 4237 vaccines would reduce their immunogenicities as a result of mutual interference. One hundred and sixty breast-fed male and female infants were randomly allocated to four study groups to receive in a blind fashion the poliovirus vaccine, the RIT 4237 vaccine, and combination of both vaccines or a placebo preparation. Antibody titres were measured in pre- and postvaccination serum samples by the ELISA test and the neutralizing antibody test (NT) for rotavirus and by the NT for polioviruses types 1 and 3. The percentage of subjects with immune responses to rotavirus in the placebo group was low, indicating the absence of wild rotavirus circulation in the population. Antibody responses against polio types 1 and 3 were found in about a quarter of the infants receiving a placebo because the study was performed during a polio vaccination campaign when vaccine viruses are known to circulate. The results showed that 73% of seroconversion was obtained when RIT 4237 was adminstered alone and that the responses to polioviruses types 1 and 3 were good. However, simultaneous administration of polio and RIT 4237 vaccines caused a significant reduction of the antibody response to rotavirus but not to polioviruses types 1 and 3.

关键词： Base Sequence   Chromosome Mapping   Crosses, Genetic   Cytopathogenic Effect, Viral   Cytopathogenic Effect, Viral   DNA-Directed RNA Polymerases/metabolism   Genetic Markers   Mutation   Poliovirus/genetics   Recombination, Genetic   RNA, Viral/metabolism   Structure-Activity Relationship  

摘要： We have investigated RNA recombination among poliovirus genomes by analyzing both intratypic and intertypic recombinant crosses involving the same defined genetic markers. Sequence analysis of the recombinant junctions of 13 nonsibling intertypic recombinants showed that intertypic RNA recombination is not site-specific, nor does it require extensive homology between the recombining parents at the crossover site. To discriminate between breaking-rejoining and copy choice mechanisms of RNA recombination, we have inhibited the replication of the recombining parents independently and found opposite effects on the frequency of genetic recombination in intratypic crosses. The results strongly support a copy choice mechanism for RNA recombination, in which the viral RNA polymerase switches templates during negative strand synthesis.

关键词： Animals   Antigens, Viral/genetics   Antigens, Viral/immunology   Epitopes/genetics   Epitopes/immunology   Genetic Engineering   Hepatitis B Surface Antigens/genetics   Hepatitis B Surface Antigens/immunology   Mice   Neutralization Tests   Neutralization Tests   Poliovirus/immunology   Viral Envelope Proteins/genetics   Viral Envelope Proteins/immunology  

摘要： The hepatitis B virus (HBV) envelope protein carrying the surface antigen (HBsAg) is assembled with cellular lipids in mammalian cells into empty viral envelopes. In a study to evaluate the capacity of such particles to present foreign peptide sequences in a biologically active form, in-phase insertions were created in the S gene encoding the major envelope protein. One of the sequences inserted was a synthetic DNA fragment encoding a poliovirus neutralization epitope. Mammalian cells expressing the modified gene secreted hybrid particles closely resembling authentic 22-nanometer HbsAg particles. These particles reacted with a poliovirus-specific monoclonal antibody and induced neutralizing antibodies against poliovirus. The results indicate that empty viral enevelopes of HBV may provide a means for the presentation of peptide sequences and for their export form mammalian cells.

摘要： A synthetic gene coding for the coat protein of tobacco mosaic virus (TMVCP) was expressed in E. coli under the direction of the lacUV5 promoter. Modification of the 3' end of the TMVCP gene by insertion of a region coding for an antigenic epitope from poliovirus type 3 resulted in the production of a hybrid TMVCP (TMVCP-polio 3). Both the E. coli-produced TMVCP and TMVCP-polio 3 were shown to assemble into virus-like rods under acidic conditions in E. coli extracts. Their purification was accomplished in a single step by chromatography on Sepharose 6B. TMVCP-polio 3 induced the formation of poliovirus neutralizing antibodies following injection into rats. The level of immune response was related to the degree of polymerization of the TMVCP-polio 3 preparations.

摘要： Between April 1982 and June 1983 four children 3 to 24 months of age were referred for evaluation of neurologic abnormalities found to be compatible with vaccine-related poliovirus infection, which had not been suspected by referring physicians. Patients were epidemiologically unrelated residents of Indiana, and none had prior symptoms suggestive of immunodeficiency. All had received poliovirus vaccine orally (first dose in three, fourth dose in one) and a diphtheria-tetanus-pertussis injection in the left anterior thigh within 30 days of symptoms. A vaccine-like strain of poliovirus was isolated from each patient, and each had symptoms (left leg paralysis in three;developmental regression, spasticity, and progressive fatal cerebral atrophy in one) persisting for at least 6 months. Immune function was normal in two with poliovirus type 3 infection, and abnormal (hypogammaglobulinemia, combined immunodeficiency) in two type 1 and type 2 infection, respectively. The incidence of observed vaccine-related poliovirus infection in Indiana recipients of orally administered poliovirus vaccine was 0.058 per 100,000 per year, significantly greater (P < 0.001) than predicted.