J亚群禽白血病病毒TCID_(50)不同测定方法的比较

为比较不同方法在测定J亚群禽白血病病毒(ALV-J)组织细胞半数感染量(TCID50)上的差异,将ALV-J传染性克隆r NX0101株同一病毒保存液以10倍梯度稀释后按照常规方法分别接种已长满DF-1细胞和鸡胚成纤维细胞(CEF)的96孔板,维持7 d后取所有细胞培养上清以ALV-p27抗原检测试剂盒检测p27抗原,细胞固定后以ALV-J特异性单克隆抗体JE9进行间接免疫荧光(IFA)检测,确定病毒感染孔后按照Reed-Muench法分别计算两种方法在两种细胞上的TCID50。结果显示,ELISA法测定该病毒在DF-1细胞和CEF细胞上的TCID50分别为10-5.4TCID50/0.1 m L和10-4.666TCID50/0.1 m L,而IFA法测定该病毒在DF-1和CEF细胞上的TCID50分别为10-6.333TCID50/0.1 m L和10-5.2TCID50/0.1 m L。结果表明,IFA比ELISA具有更高的灵敏度,并且ALV-J在DF-1细胞上复制能力比CEF更强,在DF-1细胞上测定ALV-J的TCID50更为科学。     

IFA和ELISA检测J亚群禽白血病病毒的比较研究

为比较3种禽白血病病毒(ALV)抗原检测ELISA试剂盒的特异性和灵敏度,将J亚群禽白血病病毒(ALV-J)传染性克隆rNX0101株以病毒原液(9×103TCID50)、10倍病毒稀释液(9×102TCID50)、100倍病毒稀释液(90 TCID50)接种培养于6孔板的DF1细胞,每孔均提前放入灭菌的细胞爬片,于接种后第1~6天每天取上清用3种ELISA试剂盒(A、B、C)检测ALV p27抗原,同时在接种后的第3天和第6天取出细胞爬片进行间接免疫荧光法(IFA)检测。结果表明,IFA方法对高、中、低剂量接种3 d后均可检出ALV-J的感染,而ELISA试剂盒中只有A试剂盒在高剂量接种时才能检出,试剂盒B和试剂盒C最早要在第4天才可检出;中、低剂量接种,3种试剂盒在第4~5天才能检出;第6天时,由于病毒的明显复制,无论IFA方法还是3种ELISA试剂盒都可检出ALV-J的感染。本研究结果为正确选择商品化禽白血病抗原检测试剂盒提供了借鉴。     

应用荧光定量RT-PCR检测J亚群禽白血病病毒

针对J亚群禽白血病病毒（ALV-J）基因序列保守区域设计一对特异性引物和一条特异性探针,通过构建重组阳性标准质粒作为阳性标准品,建立了检测ALV-J核酸的荧光定量PCR方法。优化反应体系和条件后进行特异性、敏感性、重复性试验。结果显示,该检测方法特异性强,与其它禽源病毒如A亚群禽白血病病毒（ALV-A）、B亚群禽白血病病毒（ALV-B）、新城疫病毒（ NDV）、禽流感病毒（AIV）、鸡传染性贫血病毒（CIAV）和马立克病病毒（MDV）均不发生交叉反应;该方法可检测到3.2×102拷贝/μL的病毒核酸,与常规RT-PCR相比,敏感性高100倍;重复性试验的变异系数小于2%。研究结果表明,建立的Real-time RT-PCR 检测方法特异性强、灵敏度高、可重复性好,可用于ALV-J的定量检测。     

差速离心对J亚群禽白血病病毒分离株SCAU11-H生物学活性影响

为探讨差速离心对J亚群禽白血病分离株SCAU11-H生物学活性的影响,本研究通过实时荧光定量RT-PCR、IFA和ELISA等方法验证差速离心后浓缩病毒的生物学活性。结果显示,在透射电镜下病毒粒子直径为60¹40 nm,由外部的囊膜和内部的电子致密的核心构成,多近似球形,也有一些类似长杆形、鼓锤形的形态;浓缩前后病毒的滴度(TCID50/m L)由原来的1.58×105/m L上升到8.89×1011/m L。浓缩病毒(105TCID50)感染细胞后,病毒复制量在1 d,3 d,5 d逐步增长,ALV-J抗原gp85和p27检测均为阳性。以上结果表明,差速离心极大提高了病毒滴度,且并不影响病毒生物学活性,浓缩后的病毒可用于后续试验研究。     

融合表达禽白血病env基因和IgG-Fc基因对鸡免疫效果研究

为研究鸡IgG-Fc作为分子佐剂是否能够增强J亚群白血病病毒env基因核酸疫苗的免疫效果,本研究克隆鸡IgG-Fc、禽白血病病毒-J(ALV-J)env基因,通过overlap-PCR将两个基因串联,构建pcDNA-env-Fc重组质粒,转染HEK293T细胞,48 h后经间接免疫荧光试验证明外源基因能够在细胞内表达。将pcDNA-env-Fc重复免疫SPF鸡3次,记录免疫过程中ALV-J env抗体动态变化,通过ELISA试剂盒检测鸡体内ALV-J env基因特异性抗体含量,结果显示第5周ALV-J抗体水平显著高于对照组(p0.05),尤其是IgG-Fc片段作为分子佐剂比ALV-J env基因疫苗更能显著刺激机体产生抗体。结果表明IgG-Fc片段可以作为ALV-J env基因疫苗有效的分子佐剂。     

核酸斑点杂交法与ELISA在SPF鸡检测弱毒疫苗中ALV污染的应用与比较

本研究对SPF鸡检查法在检测弱毒疫苗中低剂量禽白血病病毒(ALV)污染时的核酸斑点杂交法和ELISA进行了比较。分别以10 TCID_(50)/羽份和5 TCID50/羽份ALV-A人为污染一批商品化新城疫(ND)活疫苗,将污染ND疫苗各接种10只SPF鸡,以ELISA定期检测ALV抗体并利用PCR结合核酸斑点杂交法检测血液中ALV核酸。结果显示,在免疫污染疫苗后连续3周内ALV抗体全部为阴性,而核酸斑点杂交法检测表明自免疫后两周开始就出现ALV阳性。结果提示在利用经典的SPF鸡检查法检测弱毒疫苗中ALV污染时,结合对病原核酸的检测有助于节省检测时间和降低漏检率。     

某蛋用型父母代鸡群种蛋中禽白血病病毒的检测

为了检测某蛋用型父母代鸡群是否存在外源性禽白血病病毒（ALV）的感染,收集该鸡群的92枚鸡胚,每枚鸡胚无菌取蛋清2份,一份用禽白血病病毒p27抗原检测试剂盒直接检测群特异性p27抗原,同时分别将92枚鸡胚蛋清接种DF1细胞,培养维持8d后取细胞上清检测p27抗原。将p27抗原阳性样品,分别用针对ALV-J和ALV-AB的单因子血清做间接免疫荧光检测（IFA）。比较p27阳性检出率。结果表明,直接检测蛋清的检出率高于蛋清接种DF1后的细胞上清,接种DF1细胞后p27抗原阳性样品的IFA检测结果显示ALV-J的阳性率为100%,ALV-AB全部为阴性。说明该蛋用型父母代鸡群存在的外源性ALV感染主要是ALV-J,该研究为针对ALV的净化提供了可行性检测方法。     

皖南黄肉种鸡种蛋中禽白血病病毒的感染状态检测

本研究首次通过检测种蛋中禽白血病病毒(ALV)评价了皖南黄父母代肉种鸡的ALV感染状态.收集该鸡群的120枚鸡蛋,取40枚鸡蛋孵化至9～11 d后分别制备CEF,培养10 d,取细胞上清用ELISA试剂盒检测ALV p27抗原.另取80枚鸡蛋卵白直接检测p27抗原,同时分别将80枚鸡蛋卵白接种CEF(DF1),培养10 d后取细胞上清检测p27抗原.比较p27阳性检出率的结果表明,受精蛋孵化9～11 d后制备CEF,再培养10 d的细胞上清检出率(10/36)高于直接检测卵白(17/80)与卵白接种CEF(DF1)的细胞上清(7/80).将经DF1培养后p27抗原阳性样品,用针对ALV-J的单抗JE9做IFA,ALV-J的阳性率为6/7.检测该80枚鸡蛋的卵黄抗体,ALV-J、ALV-AB的抗体阳性率分别为18/80、1/80.结果表明,该皖南黄父母代肉种鸡群存在的外源性ALV感染主要为ALV-J.该研究为ALV的净化提供了可行性检测方法.     

散养淮南王土鸡J亚群禽白血病的诊断

对湖北省某农户散养的12周龄淮南王土鸡病鸡进行剖检,发现病鸡肝脏有白色肿瘤;心肌增厚,有疑似肿瘤赘生物;脾脏萎缩,切面呈暗色。用J亚群禽白血病病毒（ALV-J）特异性引物进行PCR检测,扩增出了约545 bp的条带,病鸡组织内含有ALV-J病毒核酸序列,表明该病例为ALV-J感染。     

鸡传染性法氏囊病病毒BJQ902株对三种传代细胞敏感性的比较研究

为比较Vero、DF-1和MDCK三种传代细胞对鸡传染性法氏囊病病毒(IBDV)BJQ902株的敏感性。研究采用盲传的方法,将BJQ902株分别接种Vero、DF-1和MDCK细胞,连续传代至第8代(F8),收获每代次的病毒液测定TCID50,同时应用SYBR GreenⅠ实时荧光定量RT-PCR法检测病毒拷贝数,分析不同细胞对BJQ902株的敏感性。结果表明经过8代盲传后,收获的IBDV BJQ902株在DF-1细胞、Vero细胞和MDCK细胞培养的病毒液,使用CEF细胞测定病毒滴度分别为107.9TCID50/0.1 m L、106.5TCID50/0.1 m L和103.7TCID50/0.1 m L;SYBR GreenⅠ实时荧光定量RT-PCR法检测表明IBDV在DF-1适应传代6代后,培养液的病毒拷贝数在106.5μL以上,而IBDV抗原拷贝数在Vero细胞和MDCK细胞培养液的拷贝数各代次均低于DF-1细胞。由此可见DF-1细胞对IBDV BJQ902株的敏感性高于Vero细胞和MDCK细胞。     

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。     

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。     

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。     

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。     

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。     

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.