MDGPV PT株E-box缺失感染性克隆的构建及生物学特性分析

为获得含有缺失突变体病毒全基因组的番鸭小鹅瘟病毒(MDGPV)PT株缺失病毒并分析其生物学特性,本试验以含有MDGPV PT株全长感染性DNA克隆的质粒pMDGPVPT为模板,通过重叠延伸PCR方法将5′末端倒置重复序列(5′-ITR)第287位E盒基序(E-box)缺失,获得感染性重组质粒pPT△E287。pPT△E287经卵黄囊接种转染9日龄番鸭胚后拯救出缺失病毒rPT△E287。生物学特性试验显示,rPT△E287感染番鸭胚后能够引起特征性病变,与其亲本病毒株PT相比,rPT△E287的毒价及其在番鸭胚中增殖能力有所下降。本试验为进一步了解5′-ITR中E-box的缺失与MDGPV致病力之间的关系奠定基础。     

番鸭小鹅瘟病毒PT株E盒基序缺失感染性克隆的构建及生物学特性分析

为获得含有E盒基序(E-box)缺失突变体病毒全基因组的番鸭小鹅瘟病毒(MDGPV) PT株缺失病毒并分析其生物学特性,本研究以含有MDGPV PT株全长感染性DNA克隆的质粒pMDGPVPT为模板,通过重叠延伸PCR方法将5'-末端倒置重复序列(5'-ITR)第315位E-box缺失,获得感染性重组质粒pPT-Ed315-320。pPT-Ed315-320经卵黄囊接种转染9日龄番鸭胚后拯救出缺失病毒rMDGPV-Ed315-320。生物学特性试验显示,rMDGPV-Ed315-320感染番鸭胚后能够引起其特征性病变,与其亲本病毒株PT相比,rMDGPV-Ed315-320的毒价及其在番鸭胚中增殖能力均有所下降,但在番鸭胚成纤维细胞中的复制能力增强。本研究为进一步了解5'-ITR中E-box的缺失与MDGPV致病力之间的关系奠定了基础。     

番鸭细小病毒XX株VP2基因的克隆和序列分析

根据国内外已发表的番鸭细小病毒(MDPV)FM株和GD株基因序列,应用DNAstar分子生物学软件设计1对引物,应用PCR技术扩增MDPV XX株的结构蛋白基因VP2全基因片段。将扩增得到的VP2全基因克隆到PGEM-T easy载体上,经菌液PCR鉴定后的重组子进行序列测定。结果表明,MDPV XX株基因大小为1764bp,编码587个氨基酸,其基因序列与国内外发表的FM株、GD株核苷酸序列同源性分别为98.4%和99.8%,而与同属的小鹅瘟病毒B株核苷酸同源性仅为78.2%。可见编码番鸭细小病毒结构蛋白的VP2基因较保守,且和同属的小鹅瘟病毒明显不同,这也是该病毒目前只有一个血清型的分子基础。     

运用全基因组扩增方法制备重组瘟病毒

病毒RNA的全基因组扩增为病毒致弱提供了一种新的方法。作者曾报道了一种复苏瘟病毒的全基因组扩增方法。边界病病毒-Gifhorn基因全长cDNA扩增子经长链RT-PCR扩增获得,然后用扩增子的RNA转录物拯救感染性病毒。本试验运用全基因组扩增方法高效、稳定地扩增了3株瘟病毒毒株:疫苗株C、典型猪瘟病毒Paderborn强毒株及牛病毒性腹泻病毒CP7株。扩增子被直接克隆至一个稳定的单拷贝细菌人工染色体中,以感染的RNA转录物为模板扩增产生了全长瘟病毒DNA。     

基因重组型番鸭细小病毒FJM3的全基因组特征

从1例未免疫雏番鸭细小病毒活疫苗与鹅细小病毒活疫苗的临床病死雏番鸭脏器中成功分离到1株番鸭细小病毒(FJM3株)。为明确其基因组特征,运用PCR方法,扩增出番鸭细小病毒FJM3株全基因组。结果表明,FJM3株基因组全长为5017nt,其基因组结构和经典番鸭细小病毒参考毒株一致。序列比对结果表明,FJM3株全基因组序列与GenBank中登录的经典MDPV参考株(FM株)核苷酸序列同源性为94.0%,与番鸭源GPV参考株(Y株)核苷酸序列同源性为85.6%。全基因组遗传进化分析表明,FJM3株处于MDPV遗传进化分支;VP1基因遗传分析表明,FJM3株处于经典MDPV遗传进化分支;VP3遗传进化表明,FJM3株处于GPV遗传进化分支。对FJM3株和参考株(FM株、Y株和SYG61v)进行遗传重组分析表明,该毒株于存在2处MDPV与GPV的基因重组现象。     

番鸭三种细小病毒野毒株试验感染雏鸭的临床症状及解剖病理变化差异研究

番鸭"三周病"、细小病毒型"白点病"和小鹅瘟是雏番鸭常见的三种细小病毒病,对番鸭养殖业危害较为严重。本文对从广东惠州及周边地区病死番鸭中分离鉴定的1株番鸭细小病毒型"白点病"病毒、1株小鹅瘟病毒和1株番鸭"三周病"病毒分别感染健康雏番鸭,将发病的临床症状、病理学变化进行对比,从而为基层兽医工作者提供三种番鸭细小病毒病临床鉴别、初步诊断更加直观的依据。     

番鸭细小病毒型“白点病”PCR检测方法的建立与初步应用

番鸭细小病毒型"白点病"主要侵害三周龄以内的雏番鸭。番鸭细小病毒型"白点病"通常与番鸭小鹅瘟以及番鸭"三周病"混合感染,且番鸭小鹅瘟与番鸭"三周病"临床症状和病理变化相似,因此给临床诊断带来了困难,甚至造成误诊。针对这种情况,本文在细小病毒的保守区域设计了一对细小病毒通用引物P1、P2;在番鸭"三周病"病毒的特异性区域设计了一对特异性引物M1、M2;在番鸭小鹅瘟病毒的特异性区域设计了一对特异性引物G1、G2。利用所设计的三对引物进行PCR检测,能够快速、准确地诊断出雏番鸭细小病毒型"白点病",以及与番鸭小鹅瘟或者番鸭"三周病"的混合感染。     

番鸭细小病毒国内分离株主要结构蛋白基因的克隆和序列分析

根据国外已发表的番鸭细小病毒 (MPV) FM株基因组核苷酸序列 ,设计了 1对引物 ,分别对国内 2株番鸭细小病毒分离株 MPV扬州 (YZ)株和 MPV佛山 (FS)株主要结构蛋白 (VP2和 VP3)基因进行 PCR扩增 ,并克隆到p CR3.1T载体 ,经酶切鉴定筛选出阳性克隆质粒并进行核苷酸序列分析比较。结果表明 ,MPV YZ和 MPV FS的VP2 - VP3基因大小均为 176 4bp,编码 5 88个氨基酸。 MPV YZ、MPV FS与 MPV FM核苷酸序列同源性分别为98.5 %和 98.6 % ,氨基酸序列同源性为 97.1%和 97.8% ;MPV YZ与 MPV FS核苷酸序列的同源性为 99.5 % ,氨基酸序列同源性为 98.8%。     

华南地区小鹅瘟和番鸭"三周病"分离野毒株部分VP基因的序列差异分析

为了研究华南地区小鹅瘟病毒(GPV)和番鸭"三周病"病毒(MDPV)分离野毒株部分VP基因的序列差异情况,试验从华南地区分离到疑似5株小鹅瘟病毒和2株番鸭"三周病"病毒野毒,并分析其变异情况.结果表明:华南地区小鹅瘟病毒分离野毒株的VP基因均与小鹅瘟病毒具有较近的亲缘关系,说明VP基因可能和致病性有关;番鸭"三周病"病毒分离野毒株的VP基因与小鹅瘟病毒的相似性相对较低,但均与GenBank注册登陆的小鹅瘟病毒处于同一较大分支上.     

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。