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牛病毒性腹泻病毒致病机理研究进展 总被引:6,自引:0,他引:6
牛病毒性腹泻病毒(BVDV)是危害养牛业的重要病原之一。BVDV感染能够引起广泛的临床症状,包括牛病毒性腹泻、粘膜病、持续感染与免疫耐受、繁殖障碍、血小板减少与出血综合征等,其相应的致病机理也非常复杂。持续感染是妊娠母畜在怀孕早期通过子宫内感染非致细胞病变(NCP)型BVDV引起的,是BVDV在自然环境中维持存在的一种重要形式。当持续感染动物再次感染抗原性相似或同源的致细胞病变(CP)型病毒时就会发生粘膜病。本文将粘膜病发生过程中CP型病毒的来源机制概括为五点:①外源细胞序列的插入;②病毒基因的重排和拷贝;③外源细胞序列插入同时伴有病毒基因的复制;④缺陷干扰粒子;⑤点突变。BVDV感染导致奶牛繁殖力下降的机制可能有两条:一是造成卵母细胞的质量下降,二是使性腺类固醇激素生成机制受到破坏,导致血浆中雌二醇、黄体酮等激素紊乱。血小板减少和出血性综合征是BVDV感染引起的又一重要临床症状,其致病机理主要有两种:①BVDV进入到外周循环,使外周循环中血小板受损程度增加,病理检查表现为血小板体积平均值较正常有明显增大;②BVDV感染造成骨髓生成血小板的能力下降,病理检查表现为血小板的体积平均值较正常减少。 相似文献
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猪圆环病毒(PCV)是当今危害世界养猪业最严重的病毒之一,可以造成免疫抑制,引起其他相关疾病的继发和并发感染,给养猪业造成了巨大的经济损失。通过对圆环病毒的致病机理的研究进展进行总结分析,以期为猪圆环病毒病的防控提供理论依据。 相似文献
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2009年6月份以来,在我国养殖密集的省市地区的鸡群中发生了一定比例的疑似禽白血病血管瘤,主要临床症状表现为,出现鸡爪、皮肤出血,并且流血不止直到死亡,剖检可见大肝大脾,每天死亡率在1‰~3‰。从30日龄到300日龄鸡均能见到该发病症状,多集中干120~180日龄。 相似文献
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2009年6月份以来,在我国养殖密集的省市地区的鸡群中发生了一定比例的疑似禽白血病血管瘤,主要临床症状表现为,出现鸡爪、皮肤出血,并且流血不止直到死亡,剖检可见大肝大脾,每天死亡率在1‰~3‰。从30日龄到300日龄鸡均能见到该发病症状,多集中干120~180日龄。 相似文献
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Bovine viral diarrhea virus (BVDV) is one of the most important pathogenic viruses which mainly causes bovine viral diarrhea disease (BVD). BVDV can not only cause serious clinical symptoms, but also lead to decrease of immunity of livestock and infect other pathogens, resulting in significant increase of morbidity and mortality of sick animals, and causes significant losses to the cattle industry. With the development of molecular biology theory and technology in recent years, the research on BVDV has been deepening, and some new understandings have been made to the molecular biology of the virus. In this paper, the progress of molecular biology of BVDV in recent years is described from three aspects of the composition and function of virus, the epidemic situation of BVDV gene and the genetic and mutation of BVDV gene. 相似文献
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牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)是导致牛腹泻的重要致病病毒之一,BVDV感染不仅能造成严重的临床症状,且可导致患畜的免疫力降低从而感染其他病原,致使患病动物的发病率和死亡率大大增加,给养牛业造成重大的损失。随着近年来分子生物学相关理论及技术不断发展,对于BVDV的研究逐渐深入,人们对该病毒的分子生物学方面有了一些新的了解,作者主要从BVDV的病毒粒子结构组成及功能、国内外的流行情况和BVDV基因的遗传与变异情况3个方面阐述近几年BVDV的分子生物学研究进展。 相似文献
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牛海绵状脑病病原学研究进展 总被引:3,自引:0,他引:3
牛海绵状脑病 (bovinespongiformencephalopathy ,BSE)又称疯牛病 ,是成年牛的一种神经性、进行性疾病 ,病原为一种蛋白侵染因子—朊病毒。朊病毒是一种主要在神经细胞表面发现的含有GPI(糖基磷酸肌醇 )锚定位点的正常宿主膜相关蛋白 ,它有 2种异构体PrPc_和PrPSc,其中PrPc(33~ 35kd)可被蛋白酶完全降解 ,而PrPScN_端 6 2个氨基酸被蛋白酶降解后 ,留下一段具有抗蛋白酶降解能力并具有感染性的约由141个氨基酸组成的核心片段 (2 7~ 30kD) ,而且该片段在脑内的沉积常是BSE… 相似文献
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二甲基亚砜(DMSO)、丙二醇(PROH)、乙二醇(EG)和甘油(GL)4种冷冻保护剂程序化冷冻牛GV期卵母细胞的结果表明,EG和PROH的保护效果比GL和DMSO好。4种不同冷冻方法冷冻保存牛GV期卵母细胞,比较解冻后卵母细胞的体外成熟率、受精后卵裂率。结果表明,在程序化冷冻法与细管玻璃化法(Straw)之间的差异不显著(P>0.05),在开放式拉管法(OPS)与毛细玻管法(GMP)之间的差异不显著(P>0.05);但OPS和GMP与程序化冷冻法和Straw之间的差异极显著(P<0.01)。玻璃化冷冻效果优于程序化冷冻。说明GMP和OPS玻璃化冷冻优于Straw玻璃化冷冻。说明可以采用GMP方法冷冻保存牛GV期卵母细胞。 相似文献
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牛结核病检疫方法研究进展 总被引:3,自引:2,他引:1
牛结核病主要是由牛分枝杆菌引起的一种慢性消耗性疾病,在许多国家尤其是发展中国家仍然广泛流行,该病不仅给畜牧业造成巨大的经济损失,而且严重威胁着人类的健康。因此,牛结核病的检疫意义重大。细菌学检测、免疫学检测及分子生物学诊断为牛结核病检疫的研究奠定了基础。然而,目前迫切需要研究快速、灵敏、特异的牛结核病诊断方法。牛结核病血清学诊断技术研究一直是研究热点之一,但至今仍存在许多问题。作者就这些诊断检疫方法进展作一简要介绍。 相似文献
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This study presents the gross and light microscopic features of the developing bovine metanephros. Thirty-six specimens, consisting of 19 whole embryos and foetuses, 15 foetal metanephroi, one calf kidney and one cow kidney, were examined. The development of the collecting duct system and nephron induction and formation were similar to those processes described for the human kidney but appeared to follow an accelerated time course. The bovine metanephros by 15–18 weeks gestation, had a well organized internal structure consisting of dilated major calyces, prominent minor calyces and papillae, and a definize cortex and medulla. Nephron induction started as early as 4–6 weeks gestation and was completed around 28 weeks. 相似文献
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Placenta is the link between the fetus and the maternal body during pregnancy.Therefore, the pregnancy outcome of the key was related by the normal development of the placenta.Wnt signaling pathway plays an important role in the development of embryo and placenta formation, several Wnt pathways which have been clear study and the formation process of early embryo and placenta in cattle are reviewed in this article,the early expression of the Wnt pathway components in the somatic cell nuclear transfer (SCNT) cattle and normal insemination of bovine embryos is introduced. The expression of DKK-1 and Fzd4 have a special role in the formation and development of early placenta, but its molecular mechanism is not clear. In addition, the Wnt signaling pathway is activated by inhibiting the MAP2K and GSK3, led to the inner cell mass and trophoblast cell number increased and blastocyst development speed. But it is similar to the extent of phosphorylation of E-cadherin and beta-catenin protein in the early placenta of cows with SCNT and normal insemination, therefore, the role of Wnt signaling pathway in the early formation and development of bovine placenta should be further understood and studied. 相似文献