Serological survey for Ehrlichia canis in urban dogs from the major population centres of northern Australia     

Mason RJ  Lee JM  Curran JM  Moss A  Van Der Heide B  Daniels PW 《Australian veterinary journal》2001,79(8):559-562

OBJECTIVE: To detect evidence of Ehrlichia canis infection of dogs from the major population centres of northern Australia, if present. DESIGN: Serological investigation for E. canis. PROCEDURE: The sera of 316 domestic dogs, collected from the northern Australian population centres of Townsville, Cairns, Darwin, Kununurra and Broome from May 1997 to August 1999, were investigated for evidence of infection with E. canis. Samples were tested for antibodies to E. canis using an indirect fluorescent antibody (IFA) test. The buffy coats from blood of dogs whose serum reacted in the IFA test were subsequently tested with a nested PCR to detect E. canis DNA. When available, blood from these dogs was injected into suckling mice, which were then examined for clinical disease and tested for the presence of E. canis antibodies. RESULTS: Of the 316 samples tested seven reacted in the IFA test for E. canis. None of the dogs from which these samples were obtained exhibited clinical signs of acute or chronic ehrlichiosis. The six positive samples available for testing were negative when tested with the nested PCR. Suckling mice inoculated with blood from three of the dogs whose serum was positive by IFA test showed no signs of clinical disease nor did their give positive reactions in the IFA test. CONCLUSIONS: No evidence of E. canis infection was confirmed in any of the dogs examined. Northern Australia would appear to remain free of this obligate parasite.  相似文献   

两个高度同源的RING结构域蛋白功能初步研究     

杨虹伟  翟先芝  刘志斌  王健美  李旭锋  杨毅 《中国农业科技导报》2013,15(5):100-105

泛素化途径在植物应答生物和非生物胁迫中起着重要作用,其中E3连接酶在泛素化途径中起着决定性作用。室通过在线基因芯片预测发现2个与非生物胁迫相关的拟南芥RING结构域蛋白基因At2g24480（HHR1）、At5g43200(HHR2)通过体外泛素化实验证明了二者具有E3连接酶活性。对这两个E3连接酶进行了亚细胞定位,表达谱和组织特异性分析,发现二者受诱导后的表达情况、组织特异性、亚细胞定位均不同。HHR1定位于细胞膜上,HHR2定位于细胞核;表达谱分析表明HHR1响应热和H2O2胁迫,而HHR2响应盐和H2O2胁迫;HHR1在根和花中的表达量较高,在茎和叶中的表达量较低,而HHR2在根、茎、叶中的表达量都较高,在花中表达量较低。该研究结果证实了HHR1和HHR2的一些性质和亚细胞定位,为深入研究其功能奠定了基础。  相似文献   

Performance of 2 microtiter canine Coombs' tests     

Overmann JA  Sharkey LC  Weiss DJ  Borjesson DL 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2007,36(2):179-183

BACKGROUND: The Coombs' test, which detects immunoglobulin or complement on RBC surfaces, has long been the standard for laboratory confirmation of immune-mediated hemolytic anemia (IMHA), a common cause of hemolytic anemia in the dog. This test, however, suffers from relatively low sensitivity. Optimization of test sensitivity would lead to fewer discrepancies between laboratory results and clinical diagnoses, and in some cases institution of appropriate therapy in a timely manner. OBJECTIVES: The objectives of this study were to 1) characterize the sensitivity and specificity of 2 canine Coombs' tests for the detection of IMHA, 2) document the efficacy of using multiple antisera dilutions beyond what is directed by manufacturers, and 3) evaluate the necessity of monovalent antisera in the test protocol. METHODS: Sixty-five canine whole-blood samples submitted for Coombs' testing were evaluated. Patients were classified as IMHA positive or negative based on a set of predetermined criteria. IMHA classification was compared to Coombs' test results from 2 different Coombs' tests adapted to a microtiter-plate format. One Coombs' test (VMRD Coombs' test) utilized a single polyvalent antiserum (VMRD, Inc, Pullman, WA, USA), while a second Coombs' test (University of Minnesota [U of MN] Coombs' test) used both polyvalent and monovalent antisera. RESULTS: Sensitivity and specificity were 61% and 100% for the VMRD Coombs' test, and 82% and 95% for the U of MN Coombs' test. The use of multiple antisera dilutions resulted in 6 additional Coombs' positive test results. All positive Coombs' test results were positive by polyvalent antisera. CONCLUSIONS: When used in a microtiter-plate format, the U of MN Coombs' test was a more sensitive test for the detection of IMHA in canine patients when compared to the VMRD Coombs' test. The use of multiple antisera dilutions increased test sensitivity. Sensitivity, however, was not increased by the use of monovalent antisera in the Coombs' test protocol.  相似文献   

鸡传染性支气管炎病毒S1蛋白抗原表位多肽的预测、鉴定及免疫效果的初步研究     

范文胜  朱丹  张愉  廖健淇  王露  雍璐  韦平  磨美兰 《畜牧兽医学报》2020,51(9):2257-2264

旨在对鸡传染性支气管炎病毒（IBV）H120株S1蛋白的B细胞及T细胞可能的表位进行预测并合成相应的多肽,然后免疫小鼠,并分析其免疫效果,以验证候选表位多肽的免疫原性。利用表位预测软件筛选并化学合成针对IBV H120株S1蛋白的5条表位多肽,然后免疫小鼠,通过间接ELISA、中和试验和流式细胞技术检测各表位多肽诱导的特异性抗体、中和抗体和外周血T细胞亚群。ELISA检测结果显示,5条表位多肽均具有良好的反应原性,免疫小鼠的血清效价高低顺序依次为Pep76-106 > Pep240-257 > Pep511-537 > Pep403-421 > Pep135-172;中和试验结果表明,5条多肽免疫小鼠的血清中和滴度均高于空白对照组,其高低顺序依次为Pep240-257=Pep403-421=Pep511-537>Pep76-106=Pep135-172;流式检测结果表明,5条多肽免疫小鼠在CD3⁺、CD4⁺CD8^-、CD8⁺CD4^- T淋巴细胞水平上均极显著高于空白对照组（P<0.01）,CD3⁺T及CD4⁺CD8^-T淋巴细胞数大小顺序依次为Pep403-421 > Pep240-257 > Pep76-106 > Pep511-537 > Pep135-172,CD8⁺CD4^-T淋巴细胞数大小顺序依次为Pep403-421 > Pep76-106 > Pep511-537 > Pep240-257 > Pep135-172。合成的5条表位多肽中,Pep240-257、Pep76-106和Pep403-421可以诱导体液免疫,Pep403-421可以诱导细胞免疫,其中,Pep403-421可以同时诱导细胞免疫及体液免疫。本研究结果为深入了解S1蛋白的免疫学特性以及研发诊断试剂和有效表位疫苗奠定了基础。  相似文献   

单克隆抗体用于比较禽呼肠孤病毒株的抗原关系   总被引：3，自引：0，他引：3  

陈士友  陈浦言 《南京农业大学学报》1993,16(1):96-99

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Investigation of the occurrence of Angiostrongylus vasorum in coyotes in southern Ontario,Canada     

Jonathon D. Kotwa  Manuela Schnyder  Claire M. Jardine  Peter Deplazes  David L. Pearl  Olaf Berke  Nicola Mercer  Andrew S. Peregrine 《Journal of veterinary diagnostic investigation》2021,33(4):664

In North America, the only endemic focus for Angiostrongylus vasorum (French heartworm) was historically thought to occur in the southeastern part of the island of Newfoundland. However, reports of A. vasorum infection in wild canids in West Virginia, USA, and Nova Scotia, Canada, suggest the introduction of the parasite to mainland North America. We screened for A. vasorum in coyotes from across southern Ontario. Additionally, we evaluated the performance of ELISAs for detection of circulating A. vasorum antigen (Ag-ELISA) and antibodies against A. vasorum (Ab-ELISA) designed for use in sera or blood of foxes for use with coyotes in this region. Autopsies were performed on 397 coyotes, and lung tissue extract prepared from each carcass was tested via both ELISAs. The sensitivity and specificity for both tests were estimated in the absence of a gold standard using a 2-test single population Bayesian model; sensitivity and specificity priors were based on the performance of the assays in foxes in Switzerland. Eight coyotes tested positive for A. vasorum antigen; no animal was antibody positive. The estimated sensitivity and specificity of the Ag-ELISA were 90.8% (95% credible interval [CrI]: 83.8–95.6%) and 95.5% (95% CrI: 93.4–97.2%), respectively. For the Ab-ELISA, the estimated sensitivity and specificity were 41.9% (95% CrI: 32.1–51.9%) and 98.0% (95% CrI: 96.3–99.0%), respectively. Based on these findings and negative postmortem data for the same animals, there is insufficient evidence to suggest the presence of A. vasorum in southern Ontario coyotes.  相似文献   

RT-LAMP可视化检测猪瘟病毒及特异性鉴别猪瘟兔化弱毒疫苗     

邓显文  谢芝勋  谢志勤  刘加波  庞耀珊  谢丽基  范晴  罗思思  黄莉  黄娇玲  曾婷婷  黄秀琴 《广西农业科学》2015,(2)

【目的】建立可视化检测猪瘟病毒（CSFV）及特异性鉴别猪瘟兔化弱毒疫苗株（HCLV）的逆转录环介导等温扩增技术（RT-LAMP）,为临床检测CSFV野毒株及特异性鉴别HCLV毒株提供技术支持。【方法】根据GenBank中CSFV非结构蛋白NS5B基因的保守序列,设计两套针对CSFV和HCLV的特异性引物,并优化RT-LAMP反应条件,同时用LA-320C浊度仪实时监测其浊度变化。【结果】优化的RT-LAMP仅需在63℃水浴锅中反应50 min即可完成检测,且能通过肉眼观察反应液的颜色变化直接判定结果;所有CSFV样本的检测结果均为阳性（翠绿色）,其他非CSFV样本的检测结果均为阴性（桔红色）,且能特异性鉴别HCLV毒株,与实时浊度监测结果一致。该方法对CSFV和HCLV的最小检测限分别是100和101 copies,敏感度分别是常规RT-PCR的100倍和10倍。【结论】建立的RT-LAMP特异性强、灵敏度高、方法简便,尤其适合基层进行CSFV感染的快速检测及特异性鉴别HCLV,对有效防控CSF具有重要意义。  相似文献   

Gonadotropic hormone (GtH) receptors in the testis of the troutSalmo gairdneri: in vitro studies     

Florence Le Gac  Bernard Breton  Muriel Bougoussa 《Fish physiology and biochemistry》1988,5(4):209-217

A particulate fraction obtained from trout testis at the time of spermiation shows saturable binding sites for¹²⁵I-labeled salmon gonadotropin (¹²⁵I-GtH). Non-gonadal tissues (liver, muscle and spleen) did not demonstrate specific¹²⁵I-GtH binding. The tracer's specific activity was determined by the self-displacement method (18 to 30 Ci/g). Maximal specific binding ability of¹²⁵I-GtH varied from 20 to 30% of the labelled ligand added, depending on the hormone preparation. Specific binding of¹²⁵I-GtH to 20 mg of the testis membrane varied from 40 to 85% of the total binding depending on the method of membrane prepratation, and was competitively inhibited by concentrations of unlabelled GtH ranging from ca 1 to 1000 ng/ml of incubate. Gonadotropin of mammalian origin, ovine TSH or salmon prolactin competed only weakly, or not at all, for testicular gonadotropin binding sites (relative potencies s-GtH>>FSH=hCG>s-PRL>bTSH). Scatchard analysis of equilibrium binding studies shows that saturable gonadotropin binding was due to a class of high affinity binding sites (sites I Ka3×10¹⁰ M^–1) and possibly to a second class of lower affinity binding sites (sites II Ka=5 to 14×10⁸ M^–1). The binding capacity of sites I, as measured in enriched membrane preparations, was 45±18 fmoles/g of testis during the period of spermiation. The concentration of GtH required to obtain half maximal displacement of¹²⁵I-GtH in the binding studies was of the same order of magnitude as the apparent ED50 for GtH stimulation of 11-Cetotestosterone (11KT) secretion by trout testesin vitro. Mammalian LH and FSH were 100 to 1000 folds less potent than salmor GtH to increase 11 KT secretion.  相似文献   

鹿特异性复合麻醉剂对大鼠不同脑区ATP酶活性的影响     

尹柏双  ;王秋竹  ;付连军  ;呼显生  ;石星星  ;姜胜  ;高利  ;王洪斌 《兽医大学学报》2014,(11):1842-1845

为研究鹿特异性复合麻醉剂麻醉与大鼠各脑区突触体ATP酶活性的关系,探讨其麻醉机理。将20只SD大鼠分为对照组和麻醉组,对照组大鼠腹腔注射30mL/kg生理盐水,试验组腹腔注射30mg/kg鹿特异性复合麻醉剂,采集大鼠各脑区,利用比色法测定脑区内Na＋-K＋-ATP、Ca2＋-AT P和Mg2＋-ATP酶活性。结果显示,药物作用后大鼠大脑皮层和脑干Na＋、K＋-ATP酶活性与对照组比较降低显著（P〈0.05或P〈0.01）,小脑、脑干和海马Ca2＋-ATP酶活性与对照组比较显著降低（P〈0.05或P〈0.01）,大脑Mg2＋-AT P酶活性低于对照组（P〈0.05或P〈0.01）。结果表明,麻醉引起大鼠大脑皮层、脑干中Na＋-K＋-ATP酶活性降低,大脑皮层中Mg2＋-ATP酶活性低,小脑、脑干和海马脑区中Ca2＋-ATP酶活性降低可能是鹿特异性复合麻醉剂麻醉作用的机理之一。  相似文献   

烟夜蛾血淋巴凝集素活性的研究     

张利芬  白素芬  李欣 《河南农业大学学报》2013,47(3):313-317

利用血凝法检测烟夜蛾Helicoverpa assulta血淋巴对红细胞的凝集活性和不同发育期凝集素水平,同时选取13种糖进行凝集素糖抑制反应,以明确该凝集素与烟夜蛾发育的关系和糖结合特性.研究结果表明,在烟夜蛾的不同发育期均检测有凝集素,但各龄幼虫及不同日龄蛹的凝集活性存在明显差异,雌蛹凝集素水平高于同日龄的雄蛹,表明凝集素与发育期、虫龄及蜕皮过程有关,且与性别相关.烟夜蛾蛹血淋巴凝集素活性与近缘种棉铃虫H.armigera的相类似,均被D-半乳糖、L-鼠李糖、麦芽糖、乳糖明显抑制;D-葡萄糖、D-果糖、L-岩藻糖和蔗糖等也有抑制作用,但抑制程度不同;L-阿拉伯糖与棉铃虫凝集素的专一性结合更强;N-乙酰葡萄糖胺和L-山梨糖只对棉铃虫凝集素有抑制作用,而对烟夜蛾凝集素无抑制作用,说明这2个近缘种的凝集素不完全相同.  相似文献