关键词： neuropathogenicity   attenuation  

摘要： Neuropathogenicity of poliovirus can be attenuated by mutations in the internal ribosomal entry site (IRES) within the 5' nontranslated region of its genome, The Sabin vaccine strains used in prevention of poliomyelitis carry such mutations in their IRES elements, In addition, mutations within the structural and nonstructural proteins of Sabin strains may equally contribute to the attenuation phenotype. Despite their effectiveness as vaccines, the Sabin strains retain a neuropathogenic potential in animal models for poliomyelitis and, at a very low rate, they can cause poliomyelitis in vaccine recipients. The elimination of the neurocytopathic phenotype was achieved through the exchange of the entire poliovirus IRES with its counterpart from human rhinovirus type 2 without affecting growth properties in nonneuronal cells, The attenuating effect of the human rhinovirus type 2 IRES within the context of a poliovirus genome has been mapped to the 3' portion of this genetic element.

关键词： RNA replicase   two-hybrid system   virus-host interactions  

摘要： A HeLa cDNA expression library was screened for human polypeptides that interacted with the poliovirus RNA dependent RNA polymerase, 3D, using the two-hybrid system in the yeast Saccharomyces cerevisiae, Sam68 (Src-associated in mitosis, 68 kDa) emerged as the human cDNA that, when fused to a transcriptional activation domain, gave the strongest 3D interaction signal with a LexA-3D hybrid protein. 3D polymerase and Sam68 coimmunoprecipitated from infected human cell lysates with antibodies that recognized either protein, Upon poliovirus infection, Sam68 relocalized from the nucleus to the cytoplasm, where poliovirus replication occurs. Sam68 was isolated from infected cell lysates with an antibody that recognizes poliovirus protein 2C, suggesting that it is found on poliovirus-induced membranes upon which viral RNA synthesis occurs. These data, in combination with the known RNA- and protein-binding properties of Sam68, make Sam68 a strong candidate for a host protein with a functional role in poliovirus replication.

关键词： RNA Replicase   Amino Acid Sequence   Base Sequence   DNA Primers   DNA-Directed RNA Polymerases   Hela Cells   Humans   Molecular Sequence Data   Point Mutation   Polioviruses   RNA   Viral   Research Support   U.S. Gov't   P.H.S   Structure-Activity Relationship   Temperature   Virus Replication  

摘要： Mutant ts10 is an RNA-negative temperature-sensitive mutant of Mahoney type 1 poliovirus. Mutant ts10 3D(pol) was purified from infected cells and was shown to be rapidly heat-inactivated at 45 degrees when compared to wild-type polymerase. Sequencing of mutant ts10 genomic RNA revealed a U to C transition at nt 7167 resulting in an amino acid change of methionine 394 of 3D(pol) to threonine. The 3D-M394T mutation was engineered into a wild-type infectious clone of poliovirus type 1. The resultant mutant virus, 3D-105, had a temperature-sensitive phenotype in plaque assays. The translation and replication of wild-type, ts10, and 3D-105 virion RNAs were all characterized in HeLa S10 translation-RNA replication reactions in vitro. The optimum temperatures for the replication of the wild-type and mutant viral RNAs in the HeLa S10 translation-replication reactions were 37 and 34 degrees, respectively. To characterize the temperature-sensitive defect in the replication of the mutant RNA, we used preinitiation RNA replication complexes which were formed in HeLa S10 in vitro reactions containing guanidine HCI. Negative-strand RNA synthesis in 3D-M394T mutant preinitiation replication complexes was normal at 34 degrees but was rapidly and irreversibly inhibited at 39.5 degrees. To differentiate between the initiation and elongation steps in RNA replication, we compared the elongation rates in mutant and wild-type replication complexes at 39.5 degrees. The results showed that the elongation rates for nascent negative strands in both the mutant and wild-type replication complexes were identical. Therefore, the results indicate that the heat-sensitive step in negative-strand synthesis exhibited by the 3D-M394T replication complexes is in the initiation of RNA synthesis and not in the elongation of nascent chains. (C) 1995 Academic Press, Inc.

关键词： 脊髓灰质炎病毒   聚合酶链反应   RNA  

摘要： 用聚合酶链反应(PCR)技术检测19份急性弛缓性麻痹患者(AFP)的粪便中脊髓灰质炎(脊灰)病毒,其中11份阳性,与中和试验鉴定及单克隆抗体鉴定结果符合率为90.90%～100%。该法不仅简便、敏感、特异分型,而且可作型内鉴别,为环境样品中脊灰病毒污染提供了检测手段。

关键词： 小儿麻痹   功能锻炼   临猗县   儿麻患者   肢体延长术   儿麻后遗症   手术治疗   脊髓灰质炎病毒   小儿麻痹后遗症   矫形外科器械  

摘要： 共建大厦千万间大庇天下儿麻痹者共欢颜──记山西省临猗县小儿麻痹医院脊髓灰质炎是由脊髓灰质炎病毒引起的一种急性传染病，病变以脊髓颈膨大和腰膨大的前角最明显，但也可累及整个中枢神经系统。由于病变多累及脊髓前角运动神经元，所以临床上主要表现为所支配的肌肉驰...

关键词： 脊髓灰质炎病毒   生活污水   携带者   调查   赤峰市  

摘要： 赤峰市部分地区健康人群及生活污水中脊灰病毒的调查报告刘跃宗，侯志林，孟宪坤，王永平，顾苏仪（赤峰市卫生防疫站，内蒙古自治区卫生防疫站）脊髓灰质炎病毒是引起小儿麻痹症的病原。当前世界卫生组织提出全世界于２０００年消灭脊髓灰质炎。为此，必须加强对本病的人...

关键词： 麻疹   脊髓炎质炎   疫苗   质量调查  

摘要： 麻疹及脊髓灰质炎疫苗质量纵向调查郑官增，张宗祥浙江省台州市卫生防疫站（３１７０００台州）麻疹和脊髓灰质炎（简称质灰）疫苗都是减毒的病毒活疫苗，它们对热光敏感，高温下很易灭活。为确保生物制品质量，了解“两苗”实际应用时的效价，观察“冷链”运转效果，评价...

关键词： 脊髓灰质炎病毒   流行病学   脊髓灰质炎  

摘要： 本文报道河南省脊灰流行时期的１９９１年分离的六株脊灰Ⅰ型病毒重组株的分子结构特点，以及它们与同期分离的六株脊灰Ⅰ型强毒和一株疫苗相关病毒的流行病学特征做了分析。发现六株脊灰Ⅰ型重组病毒的感染对象的年龄、免疫状况、致残特点等方面与六株脊灰Ⅰ型强毒有一定差异，与疫苗相关株也不一样。基于对资料的分析，认为重组病毒的产生投服脊灰活疫苗有关，更有可能与投服单价脊灰Ⅰ型疫苗有关。同时指出，在脊灰流行时期，大量投服脊灰活疫苗，有可能引起一部分严生的麻痹患者。这种现象可能与重组病毒的出现有关，而与脊灰Ⅰ型野病毒自身的毒力增强无直接关系。从重组脊灰Ⅰ型病毒引起的患者发病时间推断，河南脊灰Ⅰ型病毒重组病毒出现时间是在１９９１年４月以前。

关键词： poliomyelitis   HBV   vaccination   reactogenicity   immunogenicity  

摘要： The immunogenicity and reactogenicity of a booster dose of enhanced potency inactivated polio vaccine (EIPV) were evaluated in 492 healthy 12 year old adolescents. The booster was administered at the same time as the HEY vaccine compulsory in Italy at this age. Blood samples and questionnaires on reactogenicity were collected over 9 months. Analysis of pre-vaccination immunity showed that 97.4% of the subjects were protected against all polio types, 1.9% were negative for two polio types and 0.6% for one. After vaccination 98.4% of the vaccinees showed a significant increase (greater than or equal to 4 times) of antibody titre;the geometric mean titres (GMT) were markedly higher than before vaccination, particularly for poliovirus type 3. The polio booster dose did not affect HE Sr vaccination. An anti-HBs response >10 mIU ml(-1) (GMT=2951 mIU ml(-1)) was observed in 781 (98.6%) of 792 vaccinees (492 given EIPV+HBV and 300 given only HBV) 9 months later. Only mild local and rare general reactions were noted for both the vaccines studied. These data confirm the suitability and efficacy of an EIPV booster dose and HEY vaccination in adolescents. Copyright (C) 1996 Elsevier Science Ltd.

关键词： polio virus   wild type   Nigeria  

摘要： Faecal samples collected from 114 fully vaccinated pre-school children and 32 unvaccinated infants in Ibadan, Nigeria, were assayed for poliovirus in Hep-2 and RD cell cultures. 8 strains of poliovirus type 1 were isolated from 146 samples-3 from 32 unvaccinated children aged less than 40 d and 5 from 114 fully vaccinated children aged between 9 and 60 months. Studies using Sabin and wild monoclonal antibodies and the polymerase chain reaction confirmed 7 of the 8 isolates to be of the wild type, a possible source of infection among vaccinated children.