酶免疫法测定磺胺对甲氧嘧啶残留的研究：抗磺胺对甲氧嘧啶抗体的制备

ＳＭＤ常用于治疗畜禽细菌性疾病及球虫病。为了检测动物组织中的ＳＭＤ残留物，将ＳＭＤ的芳香胺基与兔血清白蛋白偶联形成全抗原。经此全抗原高免的兔子血清中含有高滴度抗半抗原ＳＭＤ的琼脂扩散和ＥＬＩＳＡ的特异性抗体。相信以此种特异性抗血清为基础的检测方法可以检出组织中的ＳＭＤ残留。     

HPLC法测定复方磺胺对甲氧嘧啶片中磺胺对甲氧嘧啶的含量

建立了兽药复方磺胺对甲氧嘧啶片中磺胺对甲氧嘧啶的高效液相色谱测定法,以C₁₈为固定相,0.1%磷酸溶液－乙腈(80：20)为流动相,流速为1.0ml/min,柱温40℃,检测波长为270nm。磺胺对甲氧嘧啶的线性范围为5.0－100μg/mL,回归方程为Area=33.5583726*Amt－12.147672(n=5),相关系数为0.99997。     

标准加入法测定猪肉中磺胺二甲嘧啶和磺胺二甲氧嘧啶残留量

采用标准加入法测定了猪肉中磺胺二甲嘧啶和磺胺二甲氧嘧啶残留量。样品经乙腈提取正己烷液液分配去脂净化后上机测定。色谱柱为C₁₈(50mm×2.1mm,1.7μm),以乙腈-0.01mol/L乙酸铵溶液为流动相进行梯度洗脱,采用电喷雾正离子(ESI+)和多反应监测(MRM)模式测定,标准加入法定量。结果表明50、100、200μg/kg三个添加水平下,回收率在(71.79±1.20)%～(93.10±3.07)%之间。本方法可排除基质效应的影响,更为准确的测定猪肉中磺胺二甲嘧啶和磺胺二甲氧嘧啶残留量。     

猪磺胺二甲氧嘧啶中毒的诊治

2004年11月18日上午，偃师市某镇一养殖户饲养的猪突然出现大批死亡，根据发病情况调查、临床症状及剖检变化，诊断为猪磺胺二甲氧嘧啶中毒。经治疗后，病情很快得到了控制，现将情况介绍如下。     

仔猪磺胺二甲氧嘧啶中毒的诊治体会

2005年8月8日,互助县一养殖户饲养的一批仔猪出现病症。根据病因调查、临床症状及剖检变化,诊断为猪磺胺二甲氧嘧啶中毒。经治疗后获得良好效果,现将诊治体会总结如下:1发病原因养殖户刘某饲养的60头仔猪(20~30 kg),于2005年6月下旬有部分仔猪在进食时有咳嗽症状,疑为猪肺炎。于是在500kg料中拌入泰乐菌素400g、磺胺二甲氧嘧啶500g,于6月30日开始饲喂,至7月5日料全部喂完。7月6日有2头25kg仔猪突然死亡,而其它猪全部出现不同程度的震颤、呕吐、拉黄色稀粪等症状。2临床症状病猪喂药2d后,开始拉黄色稀粪,饮水欲增加,眼结膜苍白、黄染,小便发…     

高效液相法测定复方磺胺对甲氧嘧啶片中磺胺对甲氧嘧啶和甲氧苄啶的含量

建立了兽用复方磺胺对甲氧嘧啶片含量测定的高效液相色谱法(HPLC)。试验采用C18色谱柱,0.1%磷酸-乙腈(85∶15)为流动相,流速为1.0 mL/min,进样量20μL,测定波长240 nm,柱温40℃。采用外标法定量计算磺胺对甲氧嘧啶和甲氧苄啶的含量。结果表明,磺胺对甲氧嘧啶在30～300μg/mL浓度范围内,其峰面积与浓度呈良好的线性关系(R~2=1),平均回收率为99.3%;甲氧苄啶在6～60μg/mL浓度范围内,其峰面积与浓度呈良好的线性关系(R~2=1),平均回收率为99.0%。HPLC方法有良好的精密度、稳定性,能够用于测定兽用复方磺胺对甲氧嘧啶片各成分的含量,对该片剂的质量控制起到重要作用。     

抗磺胺二甲氧嘧啶VHH抗体噬菌体库的构建和鉴定

旨在制备抗磺胺二甲氧嘧啶(SDM)驼源单域重链(VHH)抗体,用于检测动物源性食品中SDM的残留.采用重氮化法,SDM分别与牛血清白蛋白(BSA)和鸡卵清蛋白(OVA)偶联,合成人工免疫原(SDM-BSA)和包被抗原(SDM-OVA).用SDM-BSA免疫骆驼,在第5 次免疫后1周采集骆驼外周血液,分离外周血淋巴细胞,...     

磺胺对甲氧嘧啶在肉鸡组织中的残留研究

将艾维茵肉鸡100羽随机分成4组,在基础日粮中分别添加不同水平的磺胺对甲氧嘧啶(从第Ⅰ到第Ⅳ组分别添加0、500、1000、2000mg/kg),连喂3d后停药,并于停药后第1、2、3、5、10d时每组各捕杀鸡10只,迅速取出肝脏、肾脏、肌肉组织,用高效液相色谱法测定这些组织中磺胺对甲氧嘧啶的残留。结果表明,停药后10d内,肌肉、肝脏和肾脏中均有浓度不一的残留,其检测限达0.005mg/kg,回收率在87%以上。     

酶联免疫吸附法检测磺胺对甲氧嘧啶残留

用戊二醛法将磺胺对甲氧嘧啶 (SMD)与载体蛋白牛血清白蛋白 (BSA)偶联制备合成抗原 SMD- BSA用作免疫原 ,同法合成包被抗原 SMD- OVA(卵清蛋白 ) ,免疫家兔获得抗血清 ,用双向琼脂扩散试验和 EL ISA法对抗血清进行了定性定量测定。结果表明 ,抗血清特异性地针对 SMD,其效价为 1∶ 2 5 6 0。用所制备的抗血清建立了间接竞争EL ISA法。优选的 EL ISA的工作条件 :包被抗原最佳包被质量浓度为 5 0 mg/ L ,抗血清最佳稀释度为 1∶ 10 0 ,酶标抗体的最适工作稀释度为 1∶ 5 0 0。标准工作曲线表明 ,抗血清检测在 10～ 2 0 0 0 μg/ L 范围内呈良好的线性关系 ,超过2 0 0 0μg/ L则线性关系较差 ;该法检测底限为 6 3μg/ L ,低于国际规定残留限量 (10 0μg/ kg)和国内规定残留限量 (30 0μg/ kg)的要求。按建立的 EL ISA法测定了方法的回收率 ,无基础本底的牛奶样品回收率为 94 .7%。按药典剂量给鸡肌肉注射 SMD,连续注射 3d,在第 0～ 7天分别采血 ,按建立的 EL ISA方法测定了血清中的 SMD残留含量     

磺胺对甲氧嘧啶和二甲氧苄啶在肉鸡体内的残留消除

采用高效液相色谱-串联质谱法研究磺胺对甲氧嘧啶(SMD)和二甲氧苄啶(DVD)预混剂在白羽肉鸡体内各组织中的残留消除规律。对48只健康白羽肉鸡连续饲喂添加1 000mg/kg磺胺对甲氧嘧啶和二甲氧苄啶预混剂(含SMD 200mg,DVD 40mg)的全价饲料10d,在停药后4h,1、3、6、9、12、15d分别宰杀6只鸡,采集各组织进行药物残留测定。通过空白样品添加回收试验,所有基质中SMD和DVD的定量限分别为10μg/kg和5μg/kg,SMD和DVD分别在50、100、200μg/kg和25、50、100μg/kg 3个添加水平下的平均回收率为71.7%~102.3%,相对标准偏差为1.0%~11.9%。结果表明,磺胺对甲氧嘧啶和二甲氧苄啶预混剂在肾脏中残留量最高,肝脏其次;肌肉和皮脂中的残留量显著低于肝脏和肾脏,停药9d时,残留量低于药物残留限量。综合各组织中总残留量和最高残留限量规定,建议磺胺对甲氧嘧啶和二甲氧苄啶预混剂在鸡的休药期为7d。     

Subjective vs. objective analysis of the corneal endothelial cells in the rabbit cornea by scanning electron microscopy - a comparison of two different methods of corneal fixation

OBJECTIVE: To illustrate a method of quantitative scanning electron microscopy (SEM) for the evaluation of the corneal endothelia of small animals by comparing two commonly used fixation methods. ANIMALS STUDIED: Female New Zealand white rabbits, aged 10-12 weeks. PROCEDURES: The corneas were either dissected from the eye and placed in fixative (2% glutaraldehyde in 80 mm cacodylate, pH 7.4) or the whole eyeball immersed in fixative solution and the cornea dissected later. Lower (x 200) and high magnification (x 1,000-5,000) images were inspected for overall appearance. Magnification images (x 500) were used to measure the areas of 100 cells, and cell density (CD) calculated from the average area. RESULTS: Both fixation protocols yielded an intact endothelial surface, but the dissect- then-fix protocol resulted in more creasing and distortion artifacts that were avoided with the whole-eyeball fixation. Overall, the CD values were higher if the dissect-then-fix method was used, and the uniformity of the cell mosaic was less. The median CD values for the central, mid-peripheral and peripheral regions following dissect-then-fix protocols were 7,693, 7,353, and 7,071 cells/mm(2) (average eight corneas at each location). If the whole-globe fixation was used, the median CD values were 6,098, 5,747, and 4,785 cells/mm(2). CONCLUSION: Cell density values in SEM can be very different according to the fixation method used. A distinct regional difference in CD was evident, which was more pronounced if the cornea was fixed prior to being dissected from the eye.     

两种粪肠球菌的分离方法比较

本研究利用采集的鸡泄殖腔和猪肛门拭子样本400份,采用两种方法分离粪肠球菌并进行对比。结果显示,两种方法对4类样品中粪肠球菌的分离率分别为22%、33%、23%、22%（方法Ⅱ）和86%、91%、87%、82%（方法Ⅱ）,说明建立了准确、高效、可靠的粪肠球菌分离方法。     

猪瘟活疫苗(细胞源)两种免疫剂量的使用效果对比

根据基层实际情况,选取2种免疫剂量(1头份和6头份)的政府采购猪瘟活疫苗(细胞源),接种6个场的试验猪。比较免疫后不同时间的抗体合格率,结果显示2种免疫剂量的政府采购猪瘟活疫苗在一免后(40-50日龄)抗体水平较低,二免后(81日龄)抗体水平显著提高,均达到全群保护的合格率,且2种免疫剂量无差别。1头份免疫剂量能获得良好的免疫效果。     

三种不同方法处理的玉米青贮饲喂肉牛效果对比

摘要：本试验旨在研究不同方法处理的玉米青贮饲喂肉牛效果对比,选择体重340kg左右的西门塔尔杂交牛30头,随机分为3组,保证精饲料不变,粗饲料分别饲喂3种不同方法处理的玉米青贮,其中试验Ⅰ组为全株玉米青贮、试验Ⅱ组添加剂全株玉米青贮、试验Ⅲ组玉米秸秆黄贮,试验期70d。结果表明：1）试验Ⅱ组的平均日增重极显著高于试验Ⅰ组、试验Ⅲ组（P＜0.01）,分别比Ⅰ组、Ⅲ组高出17.57%、65.71%;Ⅲ组干物质采食量显著高于Ⅰ组、Ⅱ组（P＜0.05）;Ⅰ组和Ⅱ组料重比极显著低于Ⅲ组（P＜0.01）。试验Ⅱ组养殖效益最高为14.14元?天-1?头-1,比试验Ⅰ组高5.05元,比试验Ⅲ组高15.74元。综上,添加剂全株玉米青贮饲喂肉牛效果和养殖效益最佳,全株玉米青贮、玉米秸秆黄贮次之。     

两种粗脂肪测定方法的比较研究

以2种配合饲料和5种饲料原料作为实验材料，比较了采用国家标准（GB9433－94）测定饲料粗脂肪含量与采用改进法测定饲料粗脂肪含量的差异性。经F检验和t检验表明，两种测定方法的检测结果无显著性差异。可用改进法替代国标法来测定饲料中的粗脂肪含量。     

Serum bile acids: reference values in healthy dogs and comparison of two kit methods

Serum bile acid (SBA) reference intervals were established by use of a radioimmunoassay method for fasting dogs to be 0.2 to 4.3 micro mol/L (n = 60) and for 2 hour postprandial samples to be 0.6 to 24.2 micro mol/L (n = 37). The SBA reference intervals estimated using an enzymatic method were 0 to 8.6 micro mol/L for fasting (n = 26) and 0 to 29.8 micro mol/L for 2 hour postprandial samples (n = 36). The correlation between the two methods including samples from healthy dogs and clinical cases is good (n = 128, r = 0.82, p < 0.0001). The radioimmunoassay method is linear to 50 micro mol/L and the enzymatic method is linear to 100 micro mol/L, thus both methods require serum dilutions to be made in many cases of primary liver disease. The enzymatic method is less expensive and more convenient for use in a clinical laboratory but requires a greater sample volume (400 micro I) than the RIA method (50 micro I). Both methods have adequate precision and accuracy to be useful as diagnostic tests of liver function in dogs.     

牛结核病不同检测方法的比较研究

[目的]为达到迅速准确诊断牛结核病的目的,[方法]用2年时间对我国最常用的牛结核病检测方法进行了对比研究.[结果]试验结果表明,国标皮内变态反应试验(PPD)与皮内变态反应比较试验(SICTT)有较高符合率;国标皮内变态反应试验(PPD)阳性敏感性高于皮内变态反应比较试验(SICTT);皮内变态反应比较试验(SICTT...     

Optimization of immunohistochemical methods using two different antigen retrieval methods on formalin-fixed paraffin-embedded tissues: experience with 63 markers.

Formalin fixation produces cross-links between the proteins and the fixative that alter the ability of some antibodies to recognize antigens. We used formalin-fixed, paraffin-embedded tissues to compare two different antigen retrieval methods for 63 antibodies used in the diagnosis of infectious and neoplastic diseases of animal species. Eighty-four percent of the antibodies needed some type of antigen retrieval for optimal results. Of those antibodies, 67.7% were monoclonal and 32.3% were polyclonal. Steam heat was the method of choice for 31 antibodies. Ten antibodies reacted only with steam heat, but 9 antibodies did not react when steam heat was used. Optimal results were obtained with enzyme digestion for 22 antibodies. Only 10 antibodies yielded optimal results without antigen retrieval; 64% of these antibodies were polyclonal. All antibodies against cytokeratins were optimally retrieved with proteinese K. Antigen retrieval appears to be necessary for the majority of antibodies when used with formalin-fixed, paraffin-embedded tissues.