应用抗原捕捉ELISA快速检测牛病毒性腹泻病毒

在96孔微量板中包被BVDV(Erns)单克隆抗体,加入被检血清,血清中的病毒特异性地与抗体结合,形成抗原抗体复合物.洗涤去除未结合的物质,加入酶标抗体连接物.再洗去未结合的酶连接物,加入底物后显色,加入终止液终止反应.用装有450 nm滤光片的酶标仪进行检测,通过计算S-N值,判定血清中BVDV抗原阴性、阳性.此法具有特异、快速、灵敏的特点.     

酶标抗体反应诊断旋毛虫病

酶标抗体反应广泛用于医学、工业和农业的许多部门。该反应的原则系统如下:在聚乙烯制的免疫试验反应板的圆孔或小试管中(它们起抗原和抗体的载体作用),先后加入液体抗原、假定存在抗体的被检血清、结合物和底物。结合物乃是酶(辣根过氧化氢酶)标记的抗猪球蛋白抗体,而底物则是0.08%5-氨基水杨酸与0.05%过氧化氢的9:1混合物。构成的抗原抗体结合过程,根据底物被结合物的分解而查明,特征是被染成暗褐色,或通过被检血清的滴度和测定底物的光密度(用光比色计、分光光度计)来确定。     

酶联免疫吸附测定法在饲料毒素检测中的应用

1　酶联免疫吸附测定法 (ＥＬＩＳＡ)的基本原理及特点ＥＬＩＳＡ法是把抗原抗体的免疫反应和酶的高效催化作用原理有机地结合起来的一种检测技术。该技术的主要依据有 3点 :1 )抗体吸附在固相载体表面后 ,仍具有和抗原产生免疫反应的特性 ;2 )抗原和酶结合所形成的结合物 (酶标抗原 ) ,仍具有免疫反应特性和酶的催化特性 ;3)酶标抗原和抗体结合后 ,结合物中的酶 ,能催化底物生成有色物质 ,且颜色的深浅 ,可作为判定抗原含量的依据。ＥＬＩＳＡ测定法主要分 3类 :间接法、夹心法和竞争法。饲料中毒素大多数是小分子半抗原物质 ,因此主要采用…     

“瘦肉精”检测原理及操作步骤

1测定原理 ＂瘦肉精＂（克仑特罗）竞争酶标免疫检测的基础是抗原抗体反应。酶联板的微孔包被有针对兔抗克仑特罗特异性抗体的羊抗体（第2抗体）。加入兔抗克仑特罗特异性抗体（第1抗体）与第2抗体结合而被固定,洗涤后加入标准液或样品溶液与酶结合物（酶标记抗原）,     

酶免疫技术(EIA)和检测单克隆抗体(续)

七、酶与蛋白质结合选用酶和蛋白质结合首先要注意标记的分子情况,酶一抗原或酶一抗体结合物往往利用戊二醛法或过碘酸钠法进行制备。酶一半抗原结合物大多数     

鼻气管鸟杆菌间接ELISA检测方法的建立及应用

提取A型鼻气管鸟杆菌(ORT)外膜蛋白,经纯化后包被反应板,通过方阵滴定确定最佳抗原包被浓度、血清稀释倍数、兔抗鸡酶标二抗稀释倍数,建立了检测ORT抗体的间接ELISA方法.经方阵滴定确定最佳抗原包被质量浓度为11.85 mg/L,血清样品稀释倍数为1∶20,兔抗鸡IgG辣根过氧化物酶结合物最佳稀释倍数为1∶1 000,抗原抗体最佳结合时间为1 h,血清与二抗最适反应时间为45 min.试验结果确定的判定标准为:样品D490 nm≥0.639判定为阳性,D490 nm≤0.350判定为阴性,介于两者之间的为可疑.试验证明该方法具有良好的稳定性、重复性和特异性,将205份疑似ORT的鸡血清用本方法进行检测,其阳性检出率为11.7%(24/205).     

丝状霉形体山羊亚种血清抗体间接ELISA检测方法的建立

利用丝状霉形体山羊亚种标准株PG3制备抗原,经纯化后作为包被抗原建立了间接ELISA方法,用于检测丝状霉形体山羊亚种血清抗体。经方阵滴定确定最佳抗原包被浓度为1.09μg/mL,血清样品最佳稀释度为1∶64,兔抗羊IgG辣根过氧化物酶结合物的最佳稀释度为1∶40 000,抗原抗体最佳结合时间为1 h。判定标准为样品D490 nm值与标准阴性血清D490 nm值之比（P/N）≥3为阳性,≤2.5为阴性,介于二者之间的为可疑。重复性和稳定性试验证明,建立的间接ELISA的稳定性和重复性良好,与间接血凝试验相比,其敏感性较高。     

应用阻断酶联免疫吸附试验检测牛白血病病毒抗体

多年来,都用琼脂凝胶免疫扩散(AGID)试验检测牛白血病病毒(BLV)抗体。而此疫病的普查和根除需要检测大量的样品,酶联免疫吸附试验就可满足这一要求,间接法是先将提纯的抗原包被到固相载体,再加试验血清和特异性IgG结合物,阻断法是利用试验血清中的抗体干扰或阻断标准抗原-抗体     

应用间接酶联免疫吸附试验检测鸡传染性支气管炎抗体的研究

建立了辣根过氧化物酶标记兔抗鸡ＩｇＧ检测鸡传染性支气管炎抗体的间接ＥＩＳＡ法，其抗原包被浓度为４ｍｇ／Ｌ，待检血清与酶结合物的最佳稀释度各为１：８０，酶结合物，抗原抗体的作用时间分别为６０ｍｉｎ，３０ｍｉｎ，封闭液的浓度和作用时间分别为１％和６０ｍｉｎ，ＯＤ值大于０．２８７的判为阳性。用此法检测经ＩＢＶ灭活苗免疫鸡所产蛋孵出的雏鸡的母原抗体，ＯＤ值的Ｐ／Ｎ值为６．０，１５ｄ后降至２．０以下。检测１     

SPA与鸭IgG的结合性研究

金黄色葡萄球菌细胞壁中的A蛋白(staphylo-coccal protein A,SPA)能与多种动物的γ-球蛋白发生非特异性结合反应,而且IgG的Fc片段与SPA结合后并不影响Fab片段的免疫活性,因此在酶联免疫吸附试验(ELISA)中,常用SPA与辣根过氧化酶(HRP)交联而成SPA-HRP结合物,用于抗原、抗体的定量测定及组织切片中抗原或抗体的定位、免疫复合物的检测等[1].     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.