卵黄免疫球蛋白的应用进展

卵黄免疫球蛋白是一种来源丰富的多克隆抗体。由于卵黄抗体不能激活哺乳动物的补体系统,不与哺乳动物的Fc受体、类风湿因子、葡萄球菌蛋白A和葡萄球菌蛋白G结合,因而作为诊断试剂具有较高的敏感性。卵黄抗体具有良好的免疫活性,作为防治药物具有见效快,疗效高,无毒副作用,无残留等优点,目前卵黄抗体已得到了广泛应用。本文综述了卵黄抗体在动物病毒性疾病、细菌性疾病和寄生虫病诊断、预防和治疗等方面的应用及前景。     

如何提高缉毒犬的实际工作能力

缉毒犬对各种毒品气味的分辨能力,即一头受训犬能够在各种复杂的环境中,准确地从烟、酒、食物、糖、茶、化妆品、药材以及化学物品等干扰气味中分辨出某种毒品气味,并反应正确。目前,有些地方的缉毒犬只是对单一毒品气味进行了训练：并且考虑在更为复杂的环境下的训练,即模拟训练。这种训练接近实战,要求带犬民警充分考虑到实战现场的复杂性,并以此为标准,对模拟训练中的三种形式进行合理的布局。     

手术治疗真胃移位应注意的问题

随着奶牛单产水平的不断提高，真胃移位病例时有发生，治疗该病已是每个兽医工作者必备的技能。治疗有多种方法：禁食、泻下、健胃法和手术法。前两种方法治疗复发率比较高，后者疗效确切。笔者治疗该病采用手术疗法，在多数病例中总结出了手术法治疗该病值得注意的几个问题，写出来供同行参考。     

L-arginine prevents reduced expression of endothelial nitric oxide synthase (NOS) in pulmonary arterioles of broilers exposed to cool temperatures

This study investigated nitric oxide synthase (NOS) expression in the endothelium of pulmonary arterioles of broilers during the development of pulmonary hypertension syndrome (PHS). PHS was triggered by exposing broilers to sub-thermoneutral (cool) temperatures and an additional 1.0% L-arginine was added to the basal diet to evaluate the effects of supplemental L-arginine on nitric oxide (NO) production, endothelial NOS expression, and the incidence of PHS. Cumulative mortality from PHS, right/total ventricle weight ratios (RV/TV), and body weights were recorded. Plasma NO concentration and NOS expression in the endothelium of pulmonary arterioles with an outer diameter ranging from 100 to 200 microm were determined. Birds exposed to cool temperatures had increased pulmonary hypertension and PHS mortality and diminished endothelial NOS expression. Supplemental dietary L-arginine reduced PHS mortality and elicited higher NOS expression within the pulmonary endothelium coincident with elevated NO production. The results demonstrated that broilers developing PHS exhibited diminished NOS expression in the endothelium of their pulmonary arterioles. Supplemental L-arginine prevented the reduced expression of NOS in the pulmonary endothelium, which might contribute to the increased production of NO by the pulmonary vasculature.     

Inhibition of porcine circovirus type 1 and type 2 production in PK-15 cells by small interfering RNAs targeting the Rep gene

Porcine circovirus type 1 (PCV1) and type 2 (PCV2) are two genotypes of porcine circovirus. Both of them are presumed to be widespread in the swine population. Currently, there is no specific treatment for their infections. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism mediated by small interfering RNA (siRNA), which represents a possible therapeutic application for the treatment of viral infections. In this study, three siRNA expression plasmids (pS-RepA, pS-RepB and pS-RepC) were generated to target three different coding regions of the Rep protein (Rep) of PCV. These siRNAs were used to inhibit PCV production in a porcine kidney cell line, PK-15 cells. Our results revealed that Rep gene expression was inhibited by pS-RepA, pS-RepB and pS-RepC to different degrees. Moreover, our study also showed that the production of PCV1 and PCV2 was reduced by these siRNAs. pS-RepC, which targets the middle region of Rep gene, proved to be the most efficient siRNA for inhibition of Rep expression and viral production. Taken together, our data suggest that RNAi could be investigated as a potential treatment for PCV infection.     

一起未经检疫调运牲畜引发疫情的调查处理

1案情2003年3月23日锡盟正镶白旗改良站从通辽市科左后旗查金台牧场购入26头西门塔尔牛 (其中3头种公牛 ) ,用汽车从科尔沁区运抵锡盟正镶白旗羊场 ,并与2002年11月从通辽科左后旗查金台牧场购入的10头牛混群饲养。24日下午起 ,新购进牛陆续发病 ,至31日病牛已达26头 (新购和原购的牛都有 ) ,旗兽医站接到疫情报告后即派兽医人员到羊场调查情况 ,并采取了相应措施。兽医人员初步诊断为某一类病 ,于是向旗、盟畜牧局和政府上报疫情。并采取病料送自治区兽医站检验诊断 ,确诊为某一类传染病。2处罚经自治区动物防疫监督检验所调查取证 ,这是一…     

提高"仙湖3号"种鸭生产性能的技术措施

“仙湖3号”鸭属快大、瘦肉型新品种,成活率高,49天龄体重3.0～3.5kg,父母代种鸭具有产蛋率高,受精率高,孵化率高等优点,是“仙湖”鸭课题组培育的一个优良品系。本文简要介绍提高“仙湖3号”种鸭生产性能的技术措施,希望通过改进饲养管理,提高经济效益。     

Structural and metabolic integrity of sheep external intercostal muscle during extended culture

The objectives of this study were to examine the structural and metabolic integrity of isolated sheep external intercostal muscle bundles following variable lengths of preincubation (0 to 192 h). Samples of intact external intercostal muscle (10 to 15 g), with tendons attached, were prepared from growing wethers and maintained at their resting lengths during preincubation for 0 to 192 h. Protein synthesis (PS), protein degradation (PD), acetate oxidation and ultrastructural integrity of muscle samples were examined at 0 to 192 h, 0 to 96 h, 0 to 48 h and 0 to 96 h following isolation, respectively. Additionally, the effects of variable fetal calf serum (FCS) concentrations (0 to 20%; w/v) on PS and PD and acetate oxidation were examined. Rate of PS increased as preincubation time increased to 192 h; however, most of this increase was due to the proliferation of fibroblasts on the surface of the muscle sample. Addition of cytosine arabinoside to the incubation media prevented the fibroblast-dependent increase in PS; however, it did not entirely prevent the preincubation time-dependent increase in PS. Rate of PD increased greatly upon preincubation. The nitrogen balance of incubated muscles was negative at all times examined. Acetate oxidation was maintained through 12 h of preincubation and thereafter declined. Relatively normal myofibrillar structure was maintained through 48 h of preincubation; however, loss of mitochondrial integrity and dissolution of Z-disks at 48 h and at 96 h of preincubation were evident. Isolated tissues were able to respond to FCS concentration in medium following 48 h of preincubation.     

一种低糖型酸奶对小鼠免疫功能的影响

以低聚果糖、阿斯巴甜、木糖醇为甜味剂替代蔗糖,研制出一种低糖型酸奶。对试验组（灌胃低糖型功能酸奶）和对照组（灌胃生理盐水）分别进行脏器体重比值的测定试验、小鼠腹腔巨噬细胞吞噬鸡红细胞试验、血清溶血素含量的测定试验、血细胞计数试验。结果显示,灌胃功能酸奶的小鼠以上指标和对照组相比均有显著的提高,以此证明该酸奶具保健价值。     

蚕粪中提取叶绿素铜钠盐的稳定性研究

以蚕粪为原料,95%的乙醇为溶剂提取叶绿素,并通过化学法制得叶绿素的铜纳盐。采用721分光光度计对叶绿素铜钠盐进行定性、定量测定,确定该色素测定系统中的最大波长为414nm。通过测量吸光值研究了几种常用食品添加剂对叶绿素铜钠盐稳定性的影响,并对其耐光、耐热、耐酸碱及耐氧化性、耐还原性进行探讨。结果表明:叶绿素铜钠盐在70℃以下稳定性较好;光照对叶绿素铜钠盐稳定性的影响较大;还原剂(Na2S2O3)对叶绿素铜钠盐稳定性的影响较大,氧化剂在短时间内对其稳定性的影响不大,但放置的时间不宜超过30min;叶绿素铜钠盐在pH值为6以上的溶液中较为稳定,且有机酸及单糖对其稳定性无明显影响。