应用Dot-ELISA快速检测黑尾叶蝉体内水稻黄矮病毒研究

本文给出了应用膜上斑点免疫吸咐试验(Dot—ELISA)检测黑尾叶蝉体内水稻黄矮病毒的方法,试验研究表明:使用该方法检测比ELISA法不仅操作简便、使用抗原少,而且快速、灵敏度更高并可长期保存结果。因此,作者认为该法可作为基层单位测报时应用。     

ELISA检测姜片虫病患者抗体的研究

研究了姜片吸虫成虫冷浸抗原检测姜片吸虫病患者血清抗体的敏感性和特异性及其在流行病和临床上的应用价值．超声粉碎制备姜片吸虫成虫冷浸抗原．以评价ELISA法检测姜片虫病血清抗体的敏感性、特异性和交叉反应性．按常规ELISA方法操作,目视与酶标仪判断结果．普查2189人中姜片吸虫卵阳性者168例;168例中165例ELISA阳性,ELISA与改良加藤法的阳性符合率98．21％;健康居民血清147份,阳性6份,阳性率4．08％;与血吸虫病交叉阳性为9．38％,肺吸虫病交叉阳性为5．36％．姜片吸虫成虫冷浸抗原1：3500工作浓度包被酶标板,检测姜片虫病血清抗体具有敏感性高、特异强和交叉反应率低的特点．     

禽病消对禽多杀性巴氏杆菌的体外抑菌试验

本试验应用体外抑菌试验的试管法对复方敌菌净、喹乙醇单方和两药复方(禽病消)对禽多杀性巴氏杆菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)进行了测定.单方时复方敌菌净和喹乙醇的MIC分别为48μg/ml和6μg/ml,MBC分别为120μg/ml和15μg/ml,复方制剂(禽病消)中的复方敌菌净和喹乙醇的MIC分别为3.84μg/ml和0.84μg/ml,MBC分别为24μg/ml和3μg/ml,FIC指数为0.16,禽病消对禽多杀性巴氏杆菌的抗菌作用较复方敌菌净、喹乙醇两药单独应用时增强了12.5—32倍,结果说明:复方敌菌冷与喹乙醇联合应用具有明显的协同作用,禽病消组方合理,是防治禽巴氏杆菌病的有效复方新制剂.     

鸡肿瘤病快速鉴别诊断试剂盒及其应用研究

建立快速鉴别诊断鸡肿瘤病的聚合酶链式反应技术并研制成配套的诊断试剂盒。应用该试剂盒及其配套的操作程序,在2000年5月～2004年7月检测来源于广西6个地区202个禽群共685羽病、死鸡和火鸡的肿瘤和可疑肿瘤组织病料以及来源于安徽省不同地区的46个鸡群的疑似肿瘤病、死鸡305羽;同时,检测广西、安徽、山东、河南主要养鸡地区临床表现为生长缓慢、消瘦、贫血、疫苗免疫应答不佳、发病率和死亡率偏高等疑为免疫抑制状态的154个鸡群中的644羽病、死鸡。结果,在肿瘤和可疑肿瘤病料的检测中,马立克氏病、网状内皮增生症和禽白血病的阳性率分别为57．17％、11．84％和5．47％,其中二重、三重混合感染总检测率为16．25％。在疑似免疫抑制性疾病病料的检测中,3种鸡肿瘤病的阳性率分别为28．26％、7．45％和4．19％,其中二重、三重肿瘤病以及与其它免疫抑制性疾病的混合感染率达35．92％。建立的鸡肿瘤病快速鉴别诊断程序及试剂盒,操作简便快捷、结果准确可靠、保存方便、检测成本低,适用于临床鸡肿瘤病的鉴别诊断,对鸡肿瘤病的流行病学调查、免疫抑制病检测以及兽医检疫有重要价值。     

新疆部分地区3种鸡肿瘤性疾病的初步调查

为了调查新疆部分地区蛋鸡场疑似肿瘤性疾病,初步了解鸡肿瘤性疾病感染与发病情况,从喀什、阿克苏、玛纳斯等地区的7个养殖场抽选30份疑似肿瘤性疾病病例,进行现场剖解,采用病理组织学方法,ELISA抗原检测法,病原核酸鉴定法对其进行鉴别研究。结果显示：ELISA法检出马立克氏病、禽白血病及禽网状内皮组织增生症的阳性检出率分别为10．00％、76．66％、50．00％。其中禽白血病及禽网状内皮组织增生症的双重感染率为36．66％;PCR方法只检出马立克氏病为阳性。新疆部分地区商品蛋鸡场存在3种鸡肿瘤性疾病的感染,但引发肿瘤病变是以马立克氏病毒为主,调查结果为该类疾病的防控措施提供参考依据。     

江陵县一例J亚群禽白血病的诊断与调查分析

禽白血病是由禽C型反录病毒群引起的一类禽的多种肿瘤性疾病的统称,病毒分为A~J十个亚群。J亚群禽白血病主要引起肉鸡髓细胞瘤,1991年由美国Panyne首次报道,我国在1999年首次从市场肉鸡群中检测和分离出禽白血病病毒。ALV-J既可经垂直传播由父母代病鸡传染给子代,也可在鸡群中     

应用地高辛标记的PCR-ELISA技术快速检测转基因水稻

应用地高辛标记的PcR—ELISA(Dig-PcR—ELISA)技术进行转基因水稻检测研究。针对转基因水稻中普遍存在的花椰菜花叶病毒(CaMV)35S启动子(p35S)、胭脂碱合成酶(NOS)终止子(Thos)，筛选标记潮霉素磷酸转移酶基因(hpt,hph)、β—葡萄糖苷酸酶基因(gus)、抗草丁膦除草剂基因(bar)，建立Dig—PcR—ELISA检测方法；能进行半定量检测，敏感性试验表明，Dig—ELISA检测比常规电泳检测可提高敏感性达1000倍，可检测含量达0．1％的GM0样品。全过程可在24h内完成。     

流式荧光微球技术在实验动物质量控制中的应用

摘要: ELISA 和IFA 是实验室主要的血清学检测方法,在过去的数十年中得到广泛的应用。但其存在着操作繁琐、 耗时长的问题。美国Luminex 公司开发的xMAP 是一种快速、高通道的技术平台,可在同一反应孔内同时检测上 百种抗原、抗体、核苷酸片段、受体/配体等生物分子,在医学界已广泛应用。MFIATM 是美国Charles River Laboratories 应用xMAP 平台开发的应用于实验动物质量控制的多通路、高效率的抗体检测技术,该技术的应用大 大改善了实验动物质量控制的水平。     

利用ELISA方法鉴定大白菜TuMV抗性

为了准确鉴定大白菜分离群体中各个单株的TuMV抗/感特性,采用美国Agdia公司的TuMV检测试剂盒,利用ELISA方法,对接种后的抗、感材料和F2代单株进行检测.结果表明,对抗病材料和感病材料,ELISA检测结果与其抗性表现基本一致,能明显区分出抗病和感病.但对发病较为严重的高感病毒病材料,ELISA检测结果却为阴性.绝大多数F2代的ELISA检测结果能够说明各个单株的抗/感特性.利用ELISA方法还能对某些单株的抗/感特性进行提前预测.因此,ELISA方法可作为大白菜TuMV抗病性鉴定的有利辅助手段.     

禽用“二克星”体内外抑(杀)菌试验及疗效观察

使用禽用“二克星”对鸡病原性大肠杆菌、鸡白痢沙白氏菌进行的体外抑（杀）菌试验及对试验感染鸡大肠杆菌病的疗效试验研究结果表明：供试各菌株对禽用“二克星”均具有很高的敏感性，其最小抑菌浓度为１∶３２７６８，最小杀菌浓度为１∶４０９６。应用禽用“二克星”的预防量组和治疗量组，均比有效药物氟哌酸对照组死亡率低，其中以治疗量组保护率为最高，各致病菌型间无明显差异，说明禽用“二克星”的试验性防治效果优于临床常用药物氟哌酸     

禽流感病毒H9亚型特异性抗原捕捉ELISA检测方法的研究

 采用禽流感病毒多克隆抗体及H9亚型特异性单克隆抗体,研究建立H9亚型特异性抗原捕捉ELISA检测方法,用于检测H9亚型禽流感病毒.优化了反应条件,确定了包被抗体、检测抗体及酶结合物的最佳工作浓度,对该方法的敏感性、特异性、重复性及稳定性分析,并与RT-PCR方法比较.通过使用该方法对野外样品进行检测.结果表明该方法敏感、特异,具有良好的重复性和稳定性,可用于检测临床样品、鸡胚培养物及细胞培养物中的H9亚型禽流感病毒.     

禽流感病毒H5亚型特异性抗原捕捉ELISA检测方法的研究

 在获得禽流感病毒多克隆抗体及H5亚型特异性单克隆抗体的基础上,研究建立H5亚型特异性抗原捕捉ELISA检测方法,用于检测H5亚型禽流感病毒.优化反应条件,确定包被抗体、检测抗体及酶结合物的最佳工作浓度,进行敏感性、特异性、重复性及稳定性分析,并与RT-PCR方法比较.同时使用该方法对野外样品进行检测.结果表明:该方法敏感、特异,具有良好的重复性和稳定性,可用于检测临床样品、鸡胚培养物及细胞培养物中的H5亚型禽流感病毒.     

抗禽流感iRNA提取及其部分免疫活性的研究

为了比较不同方法抽提抗禽流感iRNA的含量、纯度,以及了解iRNA对小鼠的免疫活性,本研究就抗禽流感iRNA提取及其部分免疫活性进行了研究。结果表明:酚-氯仿抽提与Trizol reagent试剂盒抽提的效果差异不显著,所得到的iRNA含量和纯度较高,而冷热酚法抽提的效果则明显不及酚-氯仿法与Trizol reagent试剂盒;小白鼠腹腔注射提取的iRNA制剂,小白鼠生长良好,10 d内未见小白鼠有死亡,由此说明iRNA对小白鼠是安全的;禽流感HI试验及ELISA试剂盒检测iRNA免疫小白鼠血清抗体,结果为阴性,由此说明抽提的iRNA不能诱导机体产生体液免疫。     

H5N1亚型禽流感病毒血凝素基因的克隆与表达

 根据已知H5N1亚型禽流感病毒血凝素(HA)基因序列设计、合成克隆引物.自灭活的云南地方H5N1亚型病毒阳性临床组织样品中提取总RNA,反转录后采用高可信度DNA聚合酶(Pyobest^TMDNA Polymerase)扩增HA基因,采用Invitrogen定向表达系统(Champion^TMpET directional TOPO expression system)进行克隆表达,纯化获得N末端携带多聚组氨酸标签的重组HA,分子质量约78ku.采用阳性血清经免疫印迹及ELISA分析重组HA的免疫反应性,结果表明重组HA能与H5N1亚型病毒抗血清发生特异性结合,具有良好的免疫反应性.     

应用ELISA试剂盒检测鸡传染性支气管炎抗体

应用ELISA试剂盒对西宁市及乐都县344份血清样品进行了鸡传染性支气管炎抗体水平检测,结果阳性率达97．96％,其中333份样品抗体滴度在500—15000之间;1份样品的抗体滴度小于500;3份样品滴度大于15000。     

Bird-like fossil footprints from the Late Triassic

The study of fossilized footprints and tracks of dinosaurs and other vertebrates has provided insight into the origin, evolution and extinction of several major groups and their behaviour; it has also been an important complement to their body fossil record. The known history of birds starts in the Late Jurassic epoch (around 150 Myr ago) with the record of Archaeopteryx, whereas the coelurosaurian ancestors of the birds date back to the Early Jurassic. The hind limbs of Late Triassic epoch theropods lack osteological evidence for an avian reversed hallux and also display other functional differences from birds. Previous references to suggested Late Triassic to Early Jurassic bird-like footprints have been reinterpreted as produced by non-avian dinosaurs having a high angle between digits II and IV and in all cases their avian affinities have been challenged. Here we describe well-preserved and abundant footprints with clearly avian characters from a Late Triassic redbed sequence of Argentina, at least 55 Myr before the first known skeletal record of birds. These footprints document the activities, in an environment interpreted as small ponds associated with ephemeral rivers, of an unknown group of Late Triassic theropods having some avian characters.     

Characterization of the 1918 influenza virus polymerase genes

The influenza A viral heterotrimeric polymerase complex (PA, PB1, PB2) is known to be involved in many aspects of viral replication and to interact with host factors, thereby having a role in host specificity. The polymerase protein sequences from the 1918 human influenza virus differ from avian consensus sequences at only a small number of amino acids, consistent with the hypothesis that they were derived from an avian source shortly before the pandemic. However, when compared to avian sequences, the nucleotide sequences of the 1918 polymerase genes have more synonymous differences than expected, suggesting evolutionary distance from known avian strains. Here we present sequence and phylogenetic analyses of the complete genome of the 1918 influenza virus, and propose that the 1918 virus was not a reassortant virus (like those of the 1957 and 1968 pandemics), but more likely an entirely avian-like virus that adapted to humans. These data support prior phylogenetic studies suggesting that the 1918 virus was derived from an avian source. A total of ten amino acid changes in the polymerase proteins consistently differentiate the 1918 and subsequent human influenza virus sequences from avian virus sequences. Notably, a number of the same changes have been found in recently circulating, highly pathogenic H5N1 viruses that have caused illness and death in humans and are feared to be the precursors of a new influenza pandemic. The sequence changes identified here may be important in the adaptation of influenza viruses to humans.     

Identification of nuclear proteins encoded by viral and cellular myc oncogenes

The myelocytomatosis viruses are a family of replication-defective avian retroviruses that cause a variety of tumours in chickens and transform both fibroblasts and macrophages in culture through the activity of their oncogene v-myc. A closely related gene (c-myc) is found in vertebrate animals and is thought to be the progenitor of v-myc. Changes in the expression and perhaps the structure of c-myc have been implicated in the genesis of avian, murine and human tumours (for a review, see ref. 15). Elucidation of the mechanisms by which v-myc and c-myc might elicit tumorigenesis requires identification of the proteins encoded by these genes. To this end, we have expressed a portion of v-myc in a bacterial host and used the resulting protein to raise antisera that react with myc proteins. We report here that v-myc and c-myc encode closely related proteins with molecular weights (MWs) of approximately 58,000. Integration of retroviral DNA near or within c-myc in avian lymphomas apparently enhances expression of the gene. Here we have used cells from one such tumour to identify the protein encoded by c-myc and find that the coding domain for the gene is probably intact.