PCR检测鸭瘟病毒的研究

根据鸭瘟病毒DNA聚合酶基因序列，设计、合成了1对引物，以1株鸭瘟病毒疫苗株DNA为模板，进行：PCR扩增，扩增出预期563bp的目的DNA片段。将扩增出的DNA片段克隆到pMDl8—T载体，经Amp／IPTG／X-gal平板筛选，HindⅢ、XbaⅠ双酶切鉴定，获得阳性重组质粒。对重组质粒进行序列测定，与参考序列比较，二者同源性为99．3％。小鹩瘟病毒、鸭肝炎病毒、鹅副黏病毒：PCR扩增均为阴性。用此方法检测人工感染和自然感染鸭瘟的组织(脑、肝、脾)，均能检测到鸭瘟病毒DNA。PCR检测鸭瘟病毒具有高度的特异性、敏感性，能够用于鸭瘟急性及亚临床感染的检测与诊断。     

用聚合酶链反应检测鸭瘟病毒的研究

根据已发表的鸭瘟病毒基因序列 ,设计并合成了一对引物 ,其扩增跨幅为 60 2 bp。用这对引物对 6株鸭瘟病毒 DNA进行扩增 ,均获得了与设计大小相符的明亮条带 ,为阳性 ,而对其它 6株禽病病原体基因扩增不出任何条带 ,为阴性。敏感试验表明可检测到 1 0 0 fg的鸭瘟病毒 DNA模板     

用聚合酶锭反应检测鸭瘟病毒的研究

根据已发表的鸭瘟病毒基因序列，设计并合成了一对引物，其扩增跨幅为６０２ｂｐ。用这对引物对６株鸭瘟病毒ＤＮＡ进行扩增，均获得了与设计大小相符的明亮条带，为阳性率人而对其它６株禽病的原体基因扩增不出任何条带，为阴性。敏感试验表明可检测到１００ｆｇ的鸭瘟病毒ＮＤＡ模板。     

PCR用于鸭瘟病毒诊断的研究

根据鸭瘟病毒UL6和UL7基因序列,设计合成了一对引物,以2株疫苗株、1株强毒株和1株山东分离株DNA为模板,进行PCR扩增,得到预期690bp的目的片段.将扩增的目的片段克隆到pMD18-T载体,经Amp平板筛选,HindⅢ、BamHⅠ双酶切鉴定,获得阳性重组质粒.对重组质粒进行序列测定,与参考序列比较,山东分离株与参考序列的同源性为99.7%,其余3株DPV与参考序列的同源性均为100%.应用PCR可检测人工感染和自然感染鸭瘟的组织中的鸭瘟病毒,表明PCR检测鸭瘟病毒具有很高的特异性、敏感性,该法能够用于鸭瘟急性及亚临床感染的检测与诊断.     

小鹅瘟套式PCR诊断方法的建立及初步应用

本试验根据GenBank发表的小鹅瘟病毒B株基因序列,设计了两对VP3基因的特异性引物,进行PCR扩增,建立了小鹅瘟病毒套式PCR诊断方法,该方法能特异性地扩增出406 bp的小鹅瘟病毒VP3基因片段而对其他病毒基因组DNA均没有扩增出条带。本方法对病料中小鹅瘟病毒基因组DNA的最小检测量为0.02175 fg/μL。通过对延边地区疑似小鹅瘟的80只病死雏鹅进行了检测,阳性检出率为95%。结果表明,本试验建立的小鹅瘟病毒套式PCR诊断方法具有极高的敏感性和特异性且检出率极高,可作为一种有效的临床诊断方法。     

鸭瘟病毒强弱毒株PCR检测方法的建立

根据基因库中鸭瘟病毒强毒株和弱毒株UL2基因保守区设计特异性引物,优化PCR反应的引物浓度和退火温度等,初步建立了可同时鉴别鸭瘟病毒强毒株和弱毒株的PCR检测方法,并对建立的方法进行了敏感性、特异性验证和临床样品检测。该PCR检测方法最低能检出1pg的鸭瘟病毒强毒和弱毒DNA模板。对鸭瘟病毒强毒和弱毒模板的检测,得到了与试验设计相符的827bp(强毒)和299bp(弱毒)的扩增条带,而对鸭副黏病毒、鸭坦布苏病毒、鸭圆环病毒、番鸭细小病毒、鸭Ⅰ型肝炎病毒、禽流感病毒和小鹅瘟病毒等病原体的检测均为阴性。说明建立了一种敏感性高、特异性好的鉴别鸭瘟病毒强毒和弱毒的PCR检测方法。     

SYBR Green Ⅰ实时定量PCR快速检测鸭瘟病毒的研究

根据GenBank中鸭瘟病毒(DPV)UL6和UL7基因的保守序列,设计了一对特异性引物,扩增位于UL6和UL7基因第891～991位长度为101bp片断。以DPV标准强毒株DNA为模板,建立了SYBRGreenⅠ实时荧光定量PCR检测鸭瘟病毒的方法,用该方法检测鸭瘟标准强毒、疫苗毒及野毒株均为阳性,检测其他受试的非鸭瘟病毒DNA均为阴性,对鸭瘟强毒和疫苗毒人工感染鸭胚尿囊液的检出率均为100%,对6个临床送检样本的检出率为6/6,与病毒分离鉴定结果一致;最小检出量为1.57×104拷贝/ul。     

鸭瘟病毒PCR快速检测方法的建立

根据Gen Bank公布的鸭瘟病毒UL30基因保守序列设计了一对引物,建立了检测鸭瘟病毒PCR方法,并对其特异性、敏感性进行了研究。该PCR方法对鸭瘟病毒扩增结果为阳性,对照毒株扩增结果均为阴性;对鸭瘟病毒检测的灵敏性为1 pg总DNA量。以上结果表明该PCR方法特异性强、敏感性高、简便、快速,可用于鸭瘟的早期确诊和病毒鉴定。     

鸭瘟病毒UL35基因PCR方法的建立与初步应用

本研究建立了检测鸭瘟病毒（Duck pl ague vi rus,DPV）的PCR方法,并运用建立的检测方法对分离毒株和人工感染样品进行临床应用检测。根据GenBank（登录号为EF643558）中的DPV UL35基因保守区域,设计合成了一对引物,以DPV疫苗株为模板,优化PCR反应条件,建立了一种快速、有效的DPVPCR方法。结果显示：该方法能从DPV中扩增到与预期大小相符,长度为354 bp的特异性片段,而对禽流感病毒（AIV）、番鸭呼肠孤病毒（MDRV）、新城疫病毒（NDV）、番鸭细小病毒（MPV）、鹅细小病毒（GPV）等样品的扩增结果均为阴性;检测灵敏度达到470 ng病毒DNA。应用该方法对3株DPV分离株和6份由DPV BL8毒株人工感染鸭的肝脏和脾脏等组织进行PCR检测均为阳性。表明所建立的DPV PCR方法特异性强、灵敏度高,可用于DPV的临床诊断和流行病学调查。     

鸭瘟病毒的PCR鉴定及相关序列分析

设计、合成了2对鸭瘟病毒引物，对云南省发现的1例鸭瘟可疑病例(YN-DPV01)进行PCR鉴定，并对其扩增产物进行测序。结果显示，引物对被检测病料的扩增正确；所扩增的片段经序列测定与参考毒株p481的同源性为99．5％。     

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。     

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。     

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。     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

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.