鸡肌肉组织中左氧氟沙星兽药残留ELISA检测方法的研究

用N-羟基琥珀酰亚胺法把左氧氟沙星（LVL）与牛血清白蛋白（BSA）偶联制备免疫抗原,免疫新西兰大白兔得到LVL的多克隆抗体,建立了LVL间接竞争ELISA方法。结果表明：抗LVL血清效价达1∶212以上,得到标准曲线的线性回归方程为y=-0.289 4x＋0.049 5（R2=0.987 8）,50%抑制浓度（IC50）为64 ng/mL,最低检测限（LOD）为10 ng/mL,标准曲线的线性范围为10～1 000 ng/mL。批内变异系数为3.51%～7.46%,批间变异系数为8.66%～11.89%,鸡肌肉中的LVL添加浓度在10～1 000 ng/ml范围内时,回收率为73.5%～84.36%。本试验建立的ELISA方法能够满足左氧氟沙星兽药残留检测要求。     

恩诺沙星在鸡肉组织中残留的ELISA检测方法研究

分别用N-羟基琥珀酰亚胺法和氯甲酸异丁酯法把恩诺沙星(ENR)与载体蛋白牛血清白蛋白(BSA)和鸡卵清蛋白(OVA)偶联制备免疫抗原和包被抗原,免疫新西兰大白兔得到ENR的多克隆抗体,建立了ENR间接竞争ELISA方法。结果表明:抗ENR血清效价达达1∶212以上,得到标准曲线的线性回归方程为Y=-0.2341X+0.1193(R2=0.9878),中值(IC50)为36 ng/mL,最低检测限(LOD)为10 ng/mL,标准曲线的线性范围为10~1000 ng/mL。批内变异系数为3.18%~7.64%,批间变异系数为9.69%~11.94%,鸡组织中的ENR的回收率为76.5%~89.42%。本试验建立的ELISA方法能够满足恩诺沙星兽药残留检测要求。     

饲料中磺胺二甲嘧啶的检测-ELISA方法

本研究以磺胺二甲嘧啶的单克隆抗体为核心试剂建立ELISA检测方法,可检测鸡饲料和猪饲料中的磺胺二甲嘧啶。ELISA方法的标准曲线为:y=-29.448x 74.565,R2=0.9917,IC50=6.8ng/mL,线性范围为0.7～71.3ng/mL,检测限为0.3ng/mL。选择磷酸盐缓冲溶液(0.01mol/L,pH7.4)为提取溶剂,以0.1、1μg/g和10μg/g的浓度添加于空白的鸡和猪配合饲料时,其回收率为73.3～107.3%,变异系数为0.9%～19.2%。     

饲料中沙丁胺醇酶联免疫前处理方法的探究

为探讨酶联免疫法(ELISA)检测饲料中沙丁胺醇(salbutamol,SAL)的前处理方法,试验对提取液的pH、离子强度、有机溶剂浓度及样品稀释倍数等条件进行了考察,选取最适宜的提取液条件对2种不同类型的饲料样本进行提取,用ELISA测定样品中沙丁胺醇的残留量。结果表明,沙丁胺醇标准曲线的IC₅₀值为0.606 ng/mL,线性范围为0.221～1.658 ng/mL,R²=0.9998,提取液的pH为7.5,PBS缓冲液最优浓度为0.06 mol/L,稀释倍数为10倍,2种不同类型的饲料样本的检测限(LOD)为5.0 ng/mL。当沙丁胺醇的添加浓度为5、10 μg/kg时,该方法的添加回收率为77%～110%,变异系数<8%。     

ELISA方法检测牛组织中的阿维菌素类药物残留

建立一种间接竞争ELISA方法,检测牛组织中的阿维菌素类药物(Avermectins,AVMs)残留。该方法可同时检测牛肝脏和肌肉中的阿维菌素、伊维菌素和埃普里诺菌素残留。标准曲线:y=-45.613x+81.191,R2=0.9951,IC50=4.8ng/mL,线性范围为1.1ng/mL²1.9ng/mL。空白牛肝脏组织中以20、50ng/mL和100ng/g浓度添加时,AVMs回收率为53.8%21.9ng/mL。空白牛肝脏组织中以20、50ng/mL和100ng/g浓度添加时,AVMs回收率为53.8%⁸0.4%,变异系数为3.4%80.4%,变异系数为3.4%¹7.9%;空白牛肌肉组织中以5、10ng/mL和20ng/g浓度添加时,AVMs回收率为70.9%17.9%;空白牛肌肉组织中以5、10ng/mL和20ng/g浓度添加时,AVMs回收率为70.9%¹08.6%,变异系数为3.7%108.6%,变异系数为3.7%¹7.1%。     

牛奶中孕酮直接竞争ELISA检测方法的建立

采用直接竞争ELISA方法检测牛奶中孕酮含量.采用碳化二亚胺法,应用辣根过氧化物酶(HRP)标记11-α羟基孕酮琥珀酸酯(11α-OH-P4-HS),制备孕酮酶标抗原;酶标抗原与牛奶样品中的孕酮共同竞争结合固相包被的孕酮单克隆抗体,建立直接竞争ELISA反应体系.试验结果表明,最佳抗体包被浓度为1∶2 000,最佳酶标抗原工作浓度为1∶16 000,建立的标准曲线为y=-2.4598x+0.999(R2=0.996),牛奶中孕酮检测范围0.12～40 ng/mL,最低检测量为0.12 ng/mL,批内和批间变异系数分别为1.63%和2.49%.成功建立了可用于牛乳中孕酮快速检测的直接竞争ELISA方法.     

氯霉素竞争ELISA检测方法的研究

用抗氯霉素的MAb 2G2建立了检测氯霉素的竞争ELISA,对主要影响因素进行了研究,其回归方程为y=0.3522x+0.5939,相关系数为RZ=0.9906,检测线性范围为0.098 ng/mL～25 ng/mL,半数抑制浓度(IC50)为1.848 ng/mL.检测限为0.135 ng/mL.与氯霉素琥珀酸钠交叉反应率为143%,与其它结构类似物和常见抗菌素的交叉反应率均小于0.01%.批内和批间变异系数分别为4.98%和9.42%,牛奶样的平均添加回收率为101.31%.所建立的检测氯霉素竞争ELISA法,符合检测氯霉素残留的要求,为氯霉素残留快速检测试剂盒的研制奠定了基础.     

二氟沙星残留检测的Ci-ELISA方法建立

以合成的二氟沙星（DIF）人工抗原为基础，制备出了高效价抗DIF血清（1∶29×104），并建立了DIF间接竞争酶联免疫吸附测定法(Ci-ELISA法)。标准曲线的线性回归方程为y=-0.223x+0.9631(r=0.9929)，中值（I50）=119.21 ng/ml，最低检测限（LOD）=1.14 ng/ml，线性范围为1.14~10000 ng/ml，方法的平均批内变异系数（CV）为4.83%,平均批间CV为10.69%。DIF以浓度15~10000 ng/ml在鸡肉中添加时，回收率为81.24%~90.64%，变异系数为8.18%~11.75%。     

孔雀石绿间接竞争ELISA检测方法的建立

采用无色孔雀石绿(Leucomalachite green,LMG)单克隆抗体建立了水产品中孔雀石绿(Malachite green,MG)残留的间接竞争ELISA(ciELISA)检测方法。结果表明,LMG-McAb最佳稀释倍数为1∶80 000,包被抗原最佳质量浓度为0.80μg/mL;竞争反应时的LMG理想稀释液为40%乙腈水溶液;标准曲线呈线性相关,相关系数R2=0.9823,最适检测范围1 ng/mL~256 ng/mL,最低检测限为1.29 ng/mL,批内和批间变异系数分别为4.307%和4.566%;鳗鱼肉样的平均添加回收率为90%~110%;该检测方法与隐性结晶紫、孔雀石绿、结晶紫的交叉反应(CR%)分别为40.67%、13.50%和5.89%,与其他抗生素无交叉反应。     

醋酸甲孕酮（MPA）间接竞争ELISA检测方法的建立

将半抗原醋酸甲孕酮（MPA）衍生物与牛血清白蛋白(BSA)偶联后，作为包被原与游离的醋酸甲孕酮竞争抗MPA多克隆抗体，通过该模式建立间接竞争ELISA方法检测MPA的残留量。试验结果表明：理想的包被抗原为0.625 μg/ml,抗体的工作浓度为1∶8000，标准曲线在1 ～50 ng/ml之间线性关系较好，最低检测限0.1 ng/ml, 得回归方程y=-1.1479x+0.9426(r2=0.9679),批内和批间变异系数分别为5. 35%、10. 89%。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.