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牛的一种新病——牛海绵样脑病 总被引：1，自引：0，他引：1
<正> 牛海绵样脑病(Bovine SpongiformEnc?phalopathy BSE)于1985年英国首次发生,1987年首次报道。主要发生于3～8岁龄乳牛,以黑白花牛多见。肉牛也有发病的报道。根据Willian和Richard,(1990) 报道,在英国,15%的乳牛场和1%肉牛场出现BSE。对8000个牛场检疫结果认为。每周有300头以上新病例发生,至本文完稿为 相似文献
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羊痒疫、“疯牛病”及人的海绵样脑病程道祥（福建省农业厅畜牧局）近来，英国的“疯牛病”问题被新闻媒介炒得沸沸扬扬，搅得整个西欧人心惶惶，由于患病牛只的病理特征与人的海绵样脑病极为相似，并怀疑“疯牛病”的牛肉及其制品可传染给人类，因此有关国家纷纷禁止从英... 相似文献
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疯牛病研究进展 总被引：3，自引：0，他引：3
疯牛病 ( mad cow disease)是牛海绵样脑病 ( bovinespongiform encephalopathy,BSE)的俗称 ,是动物传染性海绵样脑病 ( transmissible spongiform encephalopathy,TSE)中的一种 ,1 986年首先在英国发现 [1] ,然后传播到欧洲多个国家和地区 ,给英国和欧洲的养牛业造成了巨大损失 ,并影响到相关的用牛源材料的工业。特别是随着 BSE的流行 ,由同一致病因子引起的人的变异型克雅氏症( new variant Creutzfeldt-Jakob disease,nv CJD,v CJD)的出现 ,导致了全世界对疯牛病的恐慌。可以说 ,BSE已给动物和人类健康及国际贸易等领域带来全球… 相似文献
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严防疯牛病传入中国 总被引：2，自引：0，他引：2
20世纪 80年代中期发生于英国的疯牛病 ,如今已搅得世界不安 ,特别是欧洲大陆。据在欧洲所作的一项调查表明 ,人们已达到谈牛色变的程度。在接受调查的人中 ,有一半人已停止吃牛肉。有的国家 ,已将牛肉从学生的食谱中撤消了 ,以杜绝疯牛病对人体的危害。由此可见 ,疯牛病已成为人类的新恶魔。1 疯牛病 ,医学上称为牛海绵样脑病 (bovinespongiform encephalopathy,BSE) ,是 1 985年 4月首次在英国发现的牛的致死性疾病 ,1 986年 1 1月定名为 BSE,并首次作了报道。此后 1 0余年中 ,英国已有 1 6万多头牛发生 BSE,英国政府为此付出了惨重… 相似文献
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牛海绵状脑病是国外最近几年新发现的一种疾病,又称疯牛病。本病是以脑灰质发生海绵状或海绵样变化为特征的,中枢神经系统变性的慢性疾病。该病潜伏期长,死亡率高。迄今已知,自然界的传染性海绵状脑病不仅存在于绵羊、山羊、鹿及人,还发生于野生反刍动物。最近查明,在英国牛群中已发现有“痒病样疾病”并称之为牛海绵状脑病(Bovine SpongiformEncephalopathy.BSE)。为提供一些准确判定此病的理论依据,防止本病侵入我国,特将近几年国外对 BSE 的研究情况概述如下。 相似文献
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对于疯牛病这类传染性海绵样脑病(TSE)的病原本质，虽然科学界大多数人接受美国科学家Stanley B Prusiner提出的它是一种不含有核酸的传染性蛋白因子的假说，但是对于蛋白质是否具有传染性至今仍然存在争议。而Prusiner研究组在Science杂志发表了他们的最近研究成果，即在大肠杆菌中表达的重组小鼠PrP(recMoPrP(89-230))蛋白，能够折叠成富含b片层的结构， 相似文献
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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。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献