微小隐孢子虫CP15-P23-CP15/60基因的融合表达及抗血清的制备

以微小隐孢子虫基因组DNA为模板,PCR扩增获得子孢子表面抗原CP15、P23和CP15/60基因。利用重叠延伸PCR(SOE PCR)将该3段基因片段串联在一起,各基因片段之间引入柔性氨基酸接头(GGGGS)编码基因。将串联基因克隆到原核表达载体pET-28a(+)上,构建重组表达载体,转化到大肠埃希菌BL21(DE3)中进行诱导表达,将纯化的重组蛋白免疫Balb/c小鼠制备多克隆抗体。结果表明,获得了CP15-P23-CP15/60融合基因,并在大肠埃希菌中高效表达,Western blot显示重组蛋白能被牛抗微小隐孢子虫阳性血清识别,制备的多克隆抗体能被重组蛋白特异性识别,表明获得的重组蛋白具有较好的抗原性。     

小球隐孢子虫gp15基因的克隆与核苷酸序列分析

为了给小球隐孢子虫(Cryptosporidium parvum)核酸疫苗的研制提供基因材料，用聚合酶链式反应(PCR)技术，从牛源小球隐孢子虫基因组中扩增了子孢子表面蛋白CPl5的gpl5基因(413bp)，然后将其克隆到pMDl8-T载体中，用Sanger’s双脱氧法对重组质粒中的插入片段进行序列分析。将测得的核苷酸序列及其推导的氨基酸序列与国外报道的序列进行同源性比较，结果表明核苷酸同源性为99．2％，氨基酸同源性为100％。     

微小隐孢子虫子孢子表面抗原CP15基因的克隆及核苷酸序列分析

目的对编码微小隐孢子虫(Cryptosporidium parvum)子孢子表面抗原CP15基因进行克隆和序列分析,并对其编码的氨基酸变异情况进行分析。方法对田间分离的鼠、兔、猪源微小隐孢子虫提取总RNA,经RT-PCR扩增CP15基因,克隆到pMD 18-T载体中,鉴定正确后进行序列测定,并与GenBank上下载的序列进行同源性比对。结果克隆的CP15基因核苷酸序列与GenBank登录的核苷酸序列比较,鼠源微小隐孢子虫同源性为99.23%,兔源微小隐孢子虫为97.96%,猪源微小隐孢子虫为98.72%,氨基酸序列同源性分别为100%、97.7%和98.4%。结论获得微小隐孢子虫子孢子表面抗原CP15基因,不同宿主来源的CP15基因序列高度一致,为利用该基因进行免疫预防和诊断研究奠定了基础。     

小球隐孢子虫(Cryptosporidium parvum)P15基因的克隆和表达

通过PCR扩增出小球隐孢子虫(Cryptosporidium parvum)P15基因片段。将该片段连接到克隆质粒裁体pUC19的BamH Ⅰ酶切位点上，并对其序列进行了测定。结果表明，该基因长度为479bp，编码的表面蛋白由148个氨基酸残基组成。再将P15蛋白基因片段分别在大肠杆菌和哺乳动物细胞中表达，经SDS-PAGE分析和Western blot检测，结果表明，小球隐孢子虫P15蛋白基因在大肠杆菌内获得表达的融合蛋白相对分子质量为50000；在哺乳动物细胞中，重组痘病毒表达的蛋白相对分子质量为18000-22000，与直接从自然感染牛小球隐孢子虫分离的P15蛋白的相对分子质量相似。     

小球隐孢子虫子孢子表面蛋白CP15/60原核表达载体的构建及表达

用Xho I和EcoR I酶分别从pET-28a( )和pMD18-T15/60质粒中酶切得到线性片段和CP15／60基因片段，然后用T4DNA连接酶连接，构建重组的CP15／60的原核表达载体，在大肠杆菌BL21（DE3）中表达，并用SDS－PAGE、ELISA和Westem lot进行鉴定。结果表明构建了CP15／60的原核表达载体，得到了一分子量约为16kDa的融合蛋白，占大肠杆菌总蛋白的42％。     

牛微小隐孢子虫表面抗原CP15基因原核表达及其表达产物的鉴定

试验旨在构建微小隐孢子虫表面抗原CP15基因原核表达载体并获得重组CP15蛋白。试验以已知重组质粒pMD-CP15为模板,PCR方法扩增出CP15基因片段,并亚克隆到pGEX4T-3,构建了在E.coli BL21中GST融合表达载体pGEX-CP15;经1 mmol/L IPTG进行诱导表达获得目的蛋白,其大小采用SDS-PAGE电泳和Western blotting进行鉴定。结果表明,扩增出约390 bp的微小隐孢子虫表面抗原CP15基因片段并成功构建pGEX-CP15质粒,表达出分子质量为42 ku的融合蛋白,与推导的理论值相符。Western blotting显示该蛋白能被GST血清识别。牛微小隐孢子虫表面抗原CP15基因在大肠杆菌中得到了高效表达。     

四种隐孢子虫半胱氨酸蛋白酶Cryptopain-1基因的克隆和序列分析

为克隆不同种隐孢子虫(Cryptosporidium spp.)的半胱氨酸蛋白酶Cryptopain-1基因,分析其核苷酸与编码氨基酸序列的变异情况,根据GenBank上公布的微小隐孢子虫(C.parvum)Cryptopain-1基因序列设计合成引物,用PCR技术从不同种隐孢子虫基因组DNA中扩增Cryptopain-1基因,并将其克隆至pZeroBack/blunt载体,阳性克隆经PCR鉴定正确后测序,与微小隐孢子虫Cryptopain-1基因进行序列同源性比对,并进行系统进化分析。结果显示,本研究成功从泰泽隐孢子虫(C.tyzzeri)、火鸡隐孢子虫(C.meleagridis)、兔隐孢子虫(C.cuniculus)基因组DNA中扩增出Cryptopain-1基因。与微小隐孢子虫Cryptopain-1基因比较,泰泽隐孢子虫、火鸡隐孢子虫、兔隐孢子虫Cryptopain-1基因核苷酸序列相似性分别为98.67%、94.53%、98.34%,演绎的氨基酸序列相似性分别为99.00%、96.51%、99.00%。研究结果为利用Cryptopain-1基因进行隐孢子虫的代谢、致病机理等研究奠定了基础。     

羊驼催乳素受体基因(PRLR)exon10的克隆与序列分析

通过氰仿／异戊醇法从羊驼血液和组织中提取羊驼基因组DNA，首次扩增出羊驼PRLR基因（Prolactin Receptor，PRLR）exon10序列（GenBank登录号为DQ206831），并与其它动物相应区域作了同源性比较，结果表明：羊驼PRLR基因exon10的开放阅读框为1133bp，包括1046bp的编码区和87bp的拖尾区；同源性比较显示，羊驼PRLR基因exon10的核苷酸序列与哺乳动物（牛、绵羊、猪、狗、兔、大鼠等）的同源性较高，达80％，氨基酸序列的同源性则≥66％，而与鱼类的同源性则较低，仅为40％～45％。     

火鸡隐孢子虫18S核糖体DNA部分序列测定与系统发育分析

从长春地区鸭的粪便中分离纯化了火鸡隐孢子虫（Cryptosporidium meleagridis）卵囊，根据隐孢子虫18S rDNA基因序列设计合成引物，用PCR扩增了卵囊基因组DNA大小586bp的片段，PCR产物经电泳鉴定后用试剂盒回收纯化，纯化后PCR产物直接测序，将测得的序列用Dnastar软件分析并与国外已发表的相应序列进行了同源性比较，并绘制了系统发育进化树。结果初步建立了火鸡隐孢子虫的PCR检测方法，序列分析显示长春外国语源火鸡隐孢子虫与国外9株隐孢子虫相应序旬同源性在82.7%-99.8%之间，其中与国外火鸡源火允隐孢子虫相应序列同源性为85.3%；与C.felis同源性最低，与C.muris同源性最高。本研究为火鸡隐孢子虫病诊断及该病分子流行病学研究打下了良好基础。     

鸡抗病毒Mx基因的克隆与序列分析

用干扰素诱导剂poly（I）／（C）诱导鸡胚成纤维细胞,提取细胞总RNA,采用RT—PCR方法扩增了北京白鸡Mx基因全长编码区序列。序列分析表明：该基因编码区长2118bp,编码705个氨基酸残基,其第631位为天冬酰胺,理论上推测具有抗病毒活性。通过与GenBank中已登录的7个品系鸡Mx基因进行核苷酸系统进化树分析,结果显示,北京白鸡Mx基因与WL—N品系鸡Mx基因的亲缘关系最近。北京白鸡Mx基因序列与其他动物Mx基因序列的比较结果显示,核苷酸同源性为49．5％～76．8％,氨基酸同源性为44．1％～61．6％。据此可以推断：克隆的Mx基因具有抗病毒活性的分子特征和特征性功能结构,不同种属动物Mx基因的同源性与其亲缘关系呈正相关。     

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。     

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.     

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。