猪尿液中盐酸克伦特罗残留的ELISA法和GC-MS法检测

克伦特罗(Clenbuterol，CL)，是一种人工合成的β2-肾上腺素受体激动剂。其药理作用为松弛支气管平滑肌、增加肺活量、降低气道阻力、增强支气管纤毛运动和促进痰液排出，临床上常用于防治哮喘、肺气肿等呼吸系统疾病。但当其应用剂量达治疗量的5～10倍时，CL可增强肌肉发育，降低脂肪沉积，因此又称为“瘦肉精”，常被作为饲料添加剂非法用于肉用动物的生产之中。更为重要的是，由于CL在动物体内吸收快，分布广，脂溶性高，具有残留性积累和半衰期长等药理特性。人在食用残留CL肉品后引起的中毒事件不断发生。因此，各国政府都禁止CL作为饲料添加剂用于肉用动物的生产中，我国政府也规定严禁在饲料中添加CL。同时制订了CL的最高残留限量标准。为了建立快速、敏感、特异、快速的CL免疫检测方法，本研究应用ELISA法和GC-MS法对照检测饲喂盐酸克伦特罗育肥猪的尿液样品，以确证盐酸克伦特罗快速检测ELISA试剂盒的精确性和稳定性。     

盐酸克伦特罗的危害性与检测

2 0世纪 70年代末 ,美国等发达国家首次对盐酸克伦特罗 ( CL B)开发研究 ,80年代被广泛应用到畜禽生产中。 CL B作为饲料添加剂应用于养殖业在许多省市相当普遍 ,造成动物体内的残留量相当严重 ,并相继发生了食用含CL B猪肉或内脏引起中毒的事例。人食用了残留有 CL B的畜产品对健康造成严重的危害。文章对 CL B理化特性和对人畜的危害性 ,以及应用高效液相、气相色谱法以及电泳和免疫技术对 CL B残留的检测方法进行了概述     

青海省养猪生产中盐酸克伦特罗的检测

盐酸克伦特罗(Clenbuerol，CL)是β类兴奋剂，俗称“瘦肉精”，在动物体内具有调节营养物质的流向和重新分配，促进肌肉组织生长，降低胴体脂肪含量，提高饲料报酬及肉品瘦肉率的作用。然而这种β兴奋剂残留、聚集在动物的可食组织中，人食用后会对肝、肾等内脏器官产生毒害，出现心悸、头疼、目眩、恶心、呕吐、心率加快、肌肉振颤等症状，严重者甚至死亡。中华人民共和国农业部已明令禁止在畜禽饲料中添加CL，但是近几年不法商贩受经济利益的驱使，违法滥用该药品造成中毒的事件时有报道．严重危害养殖业的发展和人民身体健康。笔者应用酶联免疫吸附试验(ELISA)对青海省重点饲料生产、经营企业和养猪场、屠宰加工厂(点)的猪饲料、饮水和肝组织及尿液中CL的含量进行了检测。     

盐酸克伦特罗在动物组织中的残留及检测

综述了盐酸克伦特罗(HCl-clenbuterol,CL)在动物体内的残留及消除特性,指出如何合理选择供检靶组织。介绍了目前常用于检测CL的几种方法及国内外禁用CL的情况,提出要防止CL的滥用,必须增强对CL危害性的认识,完善监督检测体系。     

克伦特罗和莱克多巴胺多残留胶体金免疫层析试纸条的研制

本试验旨在研制同时检测克伦特罗(CL)和莱克多巴胺(RAC)的多残留胶体金免疫层析试纸条(Multistrip).用细胞融合技术筛选CL和RAC杂交瘤细胞株,制备单克隆抗体,金标抗体竞争性膜层析技术研制Multistrip.该试纸条由样品垫、偶联垫、双检测线和质控线标记的NC膜、吸收垫等几部分构成,其中偶联垫上灌注有CL和RAC两种金标单克隆抗体,双检测线由检测抗原CL-OVA和RAC-BSA喷膜构成,间距2 mm.结果表明:多残留试纸条的CL和RAC目测检测限分别为1和2 ng·mL-1,检测时间5～8 min.基质呈阳性的真实样品用单残留试纸条、ELISA和GC-MS检测,结果一致,无假阳性或假阴性案例.该试纸条具有快速、敏感、特异、简便等特点,适合于现场检测和筛选.     

盐酸克伦特罗快速检测试纸条

盐酸克伦特罗(Clenbuterol,CLB) ,俗名“瘦肉精” ,具有“营养重分配”和“促生长剂”作用 ,20世纪80年代开始被广泛应用于畜禽生产。盐酸克伦特罗在动物体内具有吸收快、分布广、脂溶性高以及残留性积累和半衰期长等药理特性 ,人在食用残留有盐酸克伦特罗的肉品后易发生中毒。1997年以来我国政府先后颁布了一系列禁止使用盐酸克伦特罗的法律法规 ,农牧法 (2001)38号文规定ELISA方法为生猪尿样中盐酸克伦特罗快速筛选检测法。但由于ELISA检测对检测设备、环境条件、操作技能要求高 ,同时还受检测周期长、小批量检测成本高等因素的限制…     

动物源食品中抗生素残留检测分析方法的研究

为了尽量降低药物在肉品中的残留,杜绝其对人类健康的危害,国家有关部门制定了许多相应的法律法规,这就要求肉品检验部门、饲料监督检查部门加强对动物饲料和肉食品中药物残留的检测。另外,随着社会的进步和人们对抗生素残留的日益重视,对肉品中抗生素最大残留限量(MRL)的制定也越来越严格,有的已降到几个μg/kg,有的甚至规定肉品中不能检出抗生素,这就在客观上要求改进传统的检测方法,引进先进的检测仪器,寻求一种快速、精确的检测方法,使得检测结果更加准确、可靠。动物性食品中抗生素残留检测方法主要有3类:第1类为微生物检测法,如杯碟…     

盐酸克伦特罗单克隆抗体的制备及检测方法的初步建立

选择一种新型载体阳离子化牛血清白蛋白（CBSA）与半抗原盐酸克伦特罗（CL）进行偶联．鉴定后作为免疫原免疫Balb／C小鼠，同时以卵清白蛋白（OVA）与CL偶联制备筛选抗原。应用杂交瘤细胞融合技术筛选后获得了1株稳定分泌抗CL单克隆抗体的杂交瘤细胞株，命名为2H5。抗体的亚类为IgM，腹水及细胞上清间接ELISA效价分别为1：20480和1：320，通过竞争阻断实验证明其具有良好的特异性及敏感性，将半抗原经酶标后应用竞争ELISA方法初步建立了CL的检测方法，检测限可达1ng／mL，为进一步制备CL残留检测试剂盒打下了基础。     

盐酸克伦特罗单克隆抗体的制备和鉴定

为进一步建立克伦特罗(CL)残留检测方法,给制备CL残留检测试剂盒打下基础,进行了CL单克隆抗体(McAb)的制备研究。以重氮反应,将CL与牛血清白蛋白(BSA)、鸡卵清白蛋白(OVA)偶联,分别制备免疫原和检测原,并通过杂交瘤技术,获得了5株能稳定分泌特异结合CL小分子的单克隆抗体杂交瘤细胞株(1E9A9、2A9C1、3F2E9、6G2E9、6E10D9)。这5株细胞株经过体外传代培养和冻存复苏后均能稳定分泌抗体。用间接酶联免疫吸附试验(ELISA)测定的这5株细胞上清液抗体效价分别为1:1.28×10~5、1:5.12×10~5、1:1.28×10~5、1:5.12×10~5、1:2.56×10~5;选用3F2E9、6E10D9细胞株,制备CL单克隆抗体腹水并纯化,其纯化后的腹水抗体效价分别为1:1.28×10~5、1:2.56×10~5,BCA(2,2-联喹啉-4,4-二甲酸二钠)方法检测的浓度分别为1.60 mg/mL、1.54 mg/mL;最终通过斑点ELISA(Dot-ELISA)方法测定CL抗原与这2株抗体有较强的结合力。在上述方法的制备及验证下,成功获得了特异性较高的CL单克隆抗体,为进一步研制CL残留检测试剂盒奠定了基础。     

盐酸克伦特罗在我国的非法使用及安全评价

本文回顾了违禁药物盐酸克伦特罗 (CL)在我国造成的中毒事件及我国政府对其非法使用的综合治理 ,介绍了CL引起食肉中毒的残留剂量范围 ,以及实验动物和人中毒后的一般症状和心脏功能损伤 ,提高人们对CL中毒危害的认识 ,建立以筛选法和确证法检测相结合的市场监管体系和加强综合治理措施是防止CL违禁使用的关键。     

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.     

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.     

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.     

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.