TGEV S基因重组乳酸菌小鼠免疫研究*

将含有猪传染性胃肠炎病毒S基因的重组乳酸菌PNZ8149/NZ3900口服（灌胃）免疫BALB/C小鼠,第3次加强免疫后10 d捕杀小鼠,采集血液、脾脏、粪便,处理后采用T淋巴细胞增殖试验及间接ELISA方法,检查免疫小鼠对外源基因表达产物的应答情况。结果表明,含有S基因的重组乳酸菌经口服免疫小鼠后,血清中的IgG、粪便中的sIgA与对照组有明显的差异（P〈0.05）。结果说明,含有猪传染性胃肠炎病毒S基因的重组乳酸菌,可以诱导小鼠产生良好的针对猪传染性胃肠炎病毒的全身体液和黏膜免疫应答。     

Studies on the Putative Interactions between the Organophosphorus Insecticide Phosmet and Recombinant Mouse PrP and its Implication in the BSE Epidemic

It has been suggested that exposure of cattle to the ectoparasiticide Phosmet in the 1980s caused a conformational change in the cellular prion protein (PrP^C) to form the BSE prion (PrP^SC), which initiated the epidemic of bovine spongiform encephalopathy (BSE).Recombinant mouse cellular prion (r[mouse]PrP^C) was exposed to the organophosphorus pesticide Phosmet in vitro and the conformation of the prion before and after exposure was monitored using circular dichroism (CD) spectroscopy, utilizing synchrotron radiation at the Council for the Central Laboratory of the Research Councils (CLRC) facilities at Daresbury, UK. Metabolites of Phosmet, generated in situ by rat microsomes, were investigated in the same way, to determine whether they might initiate the conformational change due to their high chemical reactivity.Our studies showed that exposure of r[mouse]PrP^C to Phosmet or microsomes-generated metabolites of Phosmet did not result in the conformational change in the protein from -helix to -pleated sheet that is characteristic of the PrP^C to PrP^SC conversion and, therefore, Phosmet is very unlikely to have initiated the BSE epidemic by a simple direct mechanism of conformational change in the prion protein.     

我国部分地区传染性羊痒病基因型的分布情况调查

引起羊痒病的病原朊蛋白是一种正常的唾液酸糖蛋白(PrPc)在三级结构发生改变后形成的异常蛋白(PrPsc)。该病的发生与绵羊朊蛋白编码基因PRNP遗传多样性密切相关,主要表现在PRNP第136、154和171位密码子组成的PRNP基因型与绵羊对痒病的抗病性的联系。根据已建立的一种利用荧光定量PCR扩增反应对羊痒病抗性基因进行筛选的方法,对我国部分地区的无角多赛特绵羊羊痒病基因分布情况进行调查,从而从品种选育水平上杜绝羊痒病的发生。     

猪传染性胃肠炎病毒S基因A抗原位点序列的克隆与原核表达

将RT-PCR扩增的猪传染性胃肠炎病毒（TGEV）S基因A抗原位点目的片段克隆、双酶切后连接于表达载体,经酶切、PCR和测序鉴定的阳性重组质粒转化BL21（DE3）,用IPTG诱导,进行SDS-PAGE和Western-blotting分析,确定目的蛋白的原核表达情况和免疫特异性。结果显示,目的片段的大小为534bp,序列分析表明,该基因与其他TGEV相应基因具有很高的同源性;Western-blotting检测可见分子质量约43 ku的融合蛋白条带,表明,该蛋白具有良好的反应原性。     

多肽PrP106-126对小脑颗粒神经元凋亡相关基因表达的影响

试验旨在研究多肽PrP106-126对小脑颗粒神经元凋亡相关基因表达的影响。本研究利用多肽PrP106-126作用于小脑颗粒神经细胞,对该多肽影响小脑颗粒神经细胞凋亡基因的表达进行了检测。结果表明:bax、caspase-3和myc基因在PrP106-126多肽作用后表达显著增加,而bcl-2基因表达明显下降,进一步验证了bax、caspase-3和myc基因具有诱导凋亡作用,而bcl-2基因则具有抑制凋亡作用。     

检测猪传染性胃肠炎病毒Taq Man荧光定量RT-PCR方法的建立与初步应用

据GenBank登录的猪传染性胃肠炎病毒(TGEV)N基因的保守区序列设计合成了引物和探针,对荧光定量RT-PCR的反应条件进行了优化,建立了一种特异、灵敏、快速的TaqMan荧光定量RT-PCR方法来检测TGEV。与国外进口的An imal Genetics公司生产TGEV抗原快速检测试剂盒进行比较,符合率达到100%;与常规RT-PCR检测方法相比,灵敏度高100倍。用该方法对辽宁、山东、福建等地的送检疑似病料进行了检测,结果阳性率为24%。试验证明,所建立方法适用于猪传染性胃肠炎病毒的分子诊断、流行病学调查等相关研究。     

应用RT-PCR检测猪传染性胃肠炎病毒的研究

根据GenBank已发表的猪传染性胃肠炎病毒(porcine transmissible gastroenteritis virus,TGEV)N蛋白的基因序列,设计合成1对引物,扩增片段长度为730 bp,在优化RT-PCR反应条件的基础上,建立了检测TGEV的RT-PCR检测方法,并用该方法对疑似TGEV的猪群临床腹泻疾病进行了诊断检测和分析。本研究建立的TGEV检测方法,特异、灵敏、可靠,为该病的诊断和流行病学调查研究提供了技术保障。     

疯牛病的研究动态和我国防控体系建设

目前,欧洲、北美洲、亚洲都不同程度发生疯牛病疫情,文章重点介绍世界各国在疯牛病预防、监测、基础理论方面的研究动态,以及我国疯牛病防控体系现状。     

Organic acidemia in a young cat associated with cobalamin deficiency

Objective: To describe a case of severe metabolic acidosis and encephalopathy secondary to cobalamin (Cbl) deficiency in a young cat. Case summary: A 4‐year‐old spayed female domestic short hair cat weighing 2.5 kg, presented with a 2‐day history of neurological signs referable to the cerebrum. The cat was evaluated for similar episodes twice before, however, no definitive diagnosis was made for either visit. On presentation the cat was minimally responsive and had a metabolic acidosis and ketonuria with no apparent reason, such as lactic acidosis or diabetic ketoacidosis. The patient was diagnosed postmortem with an organic acidemia secondary to low Cbl levels. New or unique information provided: The purpose of this report is to alert emergency clinicians to be suspicious of an organic acidemia in any case of metabolic acidosis and ketonuria that cannot be explained. Early identification of inherited organic acidemias in domestic animals may allow prompt and appropriate treatment of these conditions.