检测动物组织中金刚烷胺残留的酶联免疫试剂盒的研制

通过对金刚烷胺分子结构进行改造,制备得到了金刚烷胺半抗原及人工抗原,免疫动物,制备特异性单克隆抗体。在筛选金刚烷胺单克隆抗体的基础上,建立酶联免疫检测方法,并研制出检测动物组织中金刚烷胺残留的试剂盒。该试剂盒工作范围为0.5~40.5μg/L,线性回归方程为y=-2.069x+0.493,IC_(50)为2.1μg/L,相关系数R2为0.998;试剂盒检测限为0.25μg/kg,金刚烷胺回收率在82.5%~91.0%,批内、批间变异系数均小于10%;与阿莫西林、苯唑西林、头孢噻呋三种类似结构药物均无交叉反应。该试剂盒灵敏度高、检测限低、特异性强、操作简便,可广泛用于动物组织中金刚烷胺残留量的测定。     

新型喹乙醇残留标志物人工半抗原的设计及其在动物组织残留检测中的应用

为提高酶联免疫方法测定喹乙醇残留标志物(MQCA)的检测性能,设计了一种新型MQCA人工半抗原,该半抗原既完整保留MQCA分子特征性基团和结构,又具有便于和蛋白质载体偶联的基团-NH2。通过三步化学反应合成该半抗原,将其与蛋白质载体偶联成为免疫抗原后,进一步制备特异性抗体,研制了MQCA酶联免疫试剂盒,灵敏度高,特异性好,IC50为1.94μg/L。建立了测定动物性产品中MQCA残留量的直接竞争酶联免疫法,测定猪肝、猪肉、鸡肉、鸡蛋中MQCA的检测限分别为0.42、0.23、0.28、0.28μg/kg。猪肉中不同添加浓度MQCA(1,2,4μg/kg)的回收率为70%~97%;批内、批间变异系数均低于12%。本试剂盒可同时快速检测大批样品,有望在MQCA残留检测中发挥重要作用。研究有助于指导小分子药物半抗原的合理设计,为现有的半抗原设计方法提供新的理念和思路。     

苯乙醇胺A半抗原、抗原及其制备方法的建立

在制备苯乙醇胺A半抗原、抗原和单克隆抗体的基础上应用直接竞争酶联免疫技术ELISA建立了一种检测动物组织和尿样中苯乙醇胺A残留量的方法。结果表明,半抗原改造成功,标准曲线线性检测范围为0.3μg/L~24.3μg/L,对尿样的检测限为0.3μg/L,对肉样的检测限为0.5μg/L,同其类似物交叉反应率均小于0.1%。该方法可应用于苯乙醇胺A在尿样、肉样中的快速筛查现场检测。     

可乐定ELISA检测试剂盒的研制及其性能评价

本研究通过制备可乐定完全抗原,免疫新西兰大白兔,得到特异性多克隆抗体,并和HRP标记的羊抗兔,构建间接ELISA检测法试剂盒,并进行性能测试评价。结果表明,吸光度百分比值与赛庚啶质量浓度的对数在0.1-8.1μg/L呈线性关系,相关系数R₂为0.977,半数抑制浓度(IC₅₀)为0.675μg/L,检测限为0.2μg/L,回收率为81% ～109%,具备良好的特异性,可用于动物尿样、血清和组织中的可乐定残留检测。     

阿莫西林残留ELISA检测试剂盒质量验证

为了对用于检测牛奶中阿莫西林残留的酶联免疫吸附试验(ELISA)检测试剂盒进行质量验证,试验采用不同梯度浓度的方法进行研究。结果表明:阿莫西林标准品浓度在0.5~13.5μg/L范围内具有较好线性关系,50%竞争抑制浓度为2.0μg/L,试剂盒对牛奶中阿莫西林的最低检测限为4.6μg/L。牛奶中分别添加5.0,10.0μg/L的阿莫西林标准品,回收率在72.2%~108.7%之间,批内变异系数小于8.9%,批间变异系数小于11.9%;试剂盒可在37℃条件下保存7 d,可同时检测牛奶中阿莫西林、青霉素、氨苄西林、萘夫西林等药物的残留总量。与仪器方法进行实际样品检测相比,ELISA方法检测结果具有良好的可信度。     

环境水样中地塞米松的酶联免疫法测定

通过对地塞米松分子结构进行改造,制备了地塞米松半抗原及人工抗原,免疫动物得到了地塞米松的单克隆抗体,建立了地塞米松间接竞争酶联免疫检测方法。结果表明,Logit/Log拟合标准曲线方程为Y=-2.1426X–9884,相关指数R~2为0.9965,半数抑制浓度(IC_(50))为0.337μg/L,环境水样的检测限为0.5μg/L,地塞米松阳性样本的加标回收率为75%～105%,样本重复检测结果的变异系数15%。建立的酶联免疫吸附方法具有较好的特异性、回收率和重复稳定性,可用于环境水样中地塞米松残留的检测。     

链霉素残留检测ELISA试剂盒的研制及应用

本研究采用EDC法人工合成链霉素抗原（SM—BSA）,免疫BALB／c小鼠,通过杂交瘤技术获得了分泌抗链霉素单克隆抗体的杂交瘤细胞株,建立了快速检测链霉素（SM）残留的酶联免疫方法,并成功研制了试剂盒。然后对其灵敏度、准确度、特异性、基质效应性等技术指标进行检测,同时应用该试剂盒对生长猪尿液中的残留情况进行检测。结果表明：除双氢链霉素外,该试剂盒与其它抗生素类药物均无交叉反应;线性检测范围为1～1289g／L,相关系数R^2=0．9251,灵敏度为0．45μg／L,半数抑制浓度（IC50）为7．769g／L,检测限为19g／L;猪尿样的平均添加回收率为84．1％;基质对该试剂盒的检测结果影响不大。该试剂盒具有快速、敏感、特异、简便等特点,适合于SM残留的快速检测,具有较高的推广应用价值。     

牛奶中替米考星间接竞争酶联免疫吸附检测法的建立

本研究通过棋盘法优化替米考星抗体、包被原浓度,并考察了最佳包被条件,最佳反应温度、时间和酶标二抗最佳反应时间等,建立了替米考星残留的间接竞争酶联免疫吸附试验(ELISA)并应用到牛奶样本的检测。建立的间接竞争ELISA方法半数抑制浓度(IC50)为2.1ng/mL,牛奶中替米考星的最低检测限(LOD)为2μg/L。在5、10和20μg/L添加浓度下,回收率为79.2%~90.1%,变异系数不高于9.0%。与其他常见的大环内酯类药物无交叉反应。本研究建立的替米考星间接竞争ELISA方法灵敏度达到了残留限量标准要求,为开发可用于牛奶中替米考星的快速检测试剂盒奠定基础。     

饲料中地西泮残留的酶联免疫检测试剂盒研制

为快速、简便地检测饲料中地西泮的残留,应用间接竞争酶联免疫原理研制出饲料中地西泮残留检测试剂盒,并对其性能进行评价。结果:试剂盒的灵敏度为0.1μg/L,对配合料、浓缩料、预混料的检测限分别为10、20、20μg/kg;平均添加回收率为71.5%～94.2%,批内、批间相对标准偏差均小于15%;与地西泮结构类似物无交叉反应。结果表明:研制的试剂盒检测快速、灵敏度高、特异性强,适用于从源头上对动物性食品中的地西泮残留进行检测监管。     

庆大霉素ELISA检测方法的建立与应用

本实验利用戊二醛法合成抗原,进行动物免疫,制备特异性强的单克隆抗体。建立了庆大霉素ELISA检测方法,方法灵敏度为0.1μg/L,半数抑制浓度IC50为0.295μg/kg,将建立的庆大霉素ELISA检测方法应用于肌肉组织的检测中,得到最低检测限为7.91μg/kg,样本添加回收率在70%～120%之间,变异系数小于15%,该方法的建立为庆大霉素的残留检测提供了可靠的分析检测手段。     

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 Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.