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家禽的免疫抑制与免疫失败 总被引:4,自引:0,他引:4
我国养禽业取得的辉煌成绩是和禽病研究与防制工作的进展密不可分的,但同时必须看到,我国禽病防制的总体水平不高,禽病的发生和危害仍十分严重。各种引起家禽免疫抑制和免疫失败的因素在禽病中起着越来越重要的作用,是导致疾病频发,禽群生产性能下降,死淘率增加和经济损失加大的重要原因。一、免疫抑制性疾病对家禽的影响传染性疾病是引起家禽免疫抑制的最主要原因,包括传染性囊病(IBD)、马立克氏病(MD)、禽白血病(LL)、网状内皮组织增生病(RE)、鸡传染性贫血因子(CIA)、新城疫(ND)、传染性喉气管炎(ILT)、传染… 相似文献
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<正>在生产实践中,我国养禽业免疫抑制性疾病的发生日趋严重。免疫抑制性疾病常导致家禽免疫系统受损、疫苗免疫失败、多种疾病并发或继发感染,使得家禽大批死亡,给养殖业造成巨大损失。现就家禽常见的免疫抑制性疾病的病因及其防控作一介绍,希望能给广大养禽业者提供参考。1导致家禽免疫抑制的主要因素引起家禽发生免疫抑制性疾病的因素包括非传染性因素和传染性因素。非传染性因素主要有营养缺乏、药物使用不当、霉菌毒素、管理和应激等; 相似文献
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目前在美国,爆发禽痘疾病有多种原因,即使家禽已被免疫也不例外。最近的一个报道中,伊利诺伊州立大学的DeokiTripathy博士指出:导致发病的一个最主要的致病因素是病毒基因组组成的改变。在家禽疾病中,REV和MDV都是免疫抑制性疾病,常导致抗禽痘免疫力的降低。特别在家禽遭受各种应激,如换羽、一些细菌或IBV等非相关性疾病的继发感染时。禽痘病毒基因组较大,由此引起了一些研究,包括在痘病毒基因组中插入网状内皮增生症(REV)或马立克氏病(MDV)的基因组,会导致禽痘的发生。这些研究成果表明,在野生状态下,病毒的遗传物… 相似文献
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尽管我国家禽饲养水平和集约化程度不断提高,但某些家禽肿瘤及病毒性疾病一直没有得到解决。免疫预防在疫病控制中发挥了巨大作用,但病原的变异、家禽免疫抑制病和环境等原因造成机体免疫状态低下等原因常会造成疫苗免疫的失败。因此研究通过免疫手段进行禽病治疗、提高现有疫苗的作用以及研制治疗性疫苗产品等工作,将会在解决上述问题上具有广阔的临床前景。 相似文献
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抗病毒免疫与其他微生物免疫一样 ,由非特异性和特异性免疫两部分组成 ,后者又包括体液和细胞免疫。因病毒生物学特殊 ,其免疫性具有明显特点 :1为彻底清除体内病毒 ,免疫效应物质须直接作用于病毒感染的靶细胞 ,或中断病毒大分子物质的合成 ,或破坏细胞使病毒丧失赖以生存的环境 ,这类免疫主要是细胞免疫 ,特别在有包膜病毒感染中 ,细胞免疫的作用尤为突出 ;2多种病毒在进入易感细胞之前都存在一定阶段的胞外游离状态 ,只有在这一阶段体液免疫才能充分发挥作用 ;3在病毒存在的不同阶段细胞免疫和体液免疫互相配合 ,扩大作用才能将其杀死。总之 ,在大多数情况下细胞免疫在抗病毒免疫中占主导地位 ,而体液免疫的作用是有限的。 相似文献
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随着畜牧业现代化,我国建立了许多集约化、工厂化、规模化的养殖小区。各地随着大规模的引种;养殖场内饲养密度的加大;养殖疾病防控知识更新慢等因素,造成动物疾病时常发生。特别是现阶段禽流感,口蹄疫等人畜共患病的发生,导致养殖户蒙受巨大经济损失。实践证明,免疫接种能卓有成效地控制甚至根除疾病,防治动物疫病时,接种疫苗免疫是控制传染病发生的最有效的利剑。接种疫苗提高动物的免疫力来预防疾病,基于“治病不如防病”这样一个常识性原则,疫苗接种已在世界范围广泛常规使用。免疫接种可以有效防止疫病的发生。然而目前许多养殖户没有认识到疫苗接种的重要性,不能熟练掌握免疫技术,不能合理制定, 相似文献
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Immunity in neonates 总被引:1,自引:0,他引:1
Passively derived maternal immunity hampers active immunization of newborns. Further, an immature immune system contributes to a weak and Th2 polarized immunity. This state of immunity in early life sustains endemic infections in man and continuous reinfections in animal herds. The endemic infections of the young occur preferentially when the immune system is still functionally immature and when the low levels of maternal antibodies are no longer protective but yet blocks protective immune responses. Vaccines overcoming these problems would have strong positive effects on the herd health and environmental benefits. The Th2 bias of the newborn is mediated by high levels of progesterone and Th2 cytokines produced in the maternal-fetal interface. The activity of the innate system is enhanced in the mother during the prepartus period, certainly having effects on the offspring. Newborn, 2-days-old, mice can be primed with Sendai virus envelope proteins as model antigens to induce Th1 or Th2 responses, dependent on the supplementation of the virus antigen formulation with Th1 or Th2 adjuvants. This priming has a strong life-long effect when complemented with subsequent boosts. However and importantly this priming effect can be modulated by adjuvants focusing for Th1 and Th2 when applied to the mice at 6 weeks of age, i.e. when they are immunologically adult. It has been shown in various species, besides mice, i.e. dog, sheep, horse and seal, that a strong Th1 driving adjuvant can induce immune response and protection in newborns when conventional vaccines fail. In conclusion, the Th2 bias prevailing around partus can be overcome by appropriate immunological treatments, permitting effective vaccination and protective immunity in the newborn. 相似文献
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P H Klesius 《Veterinary parasitology》1988,27(1-2):159-167
Control of ostertagiasis is a major economic problem in the temperate areas of the world. An immunological control scheme for cattle is an important aspect of integrated control and its achievement is dependent on our understanding of how immunity is acquired. Also, host mechanisms regulated by Ostertagia need to be understood in order to address immunological questions. Little is known about acquired immunity to Ostertagia infection in cattle. The degree of immunity is incomplete and its development slow. Evidence is accumulating for impairment of antibody and cellular immune responses by Ostertagia which is responsible for the survival of the parasite in the young host. Other experimental work suggests that local factors, such as eosinophil accumulation, mucosal mast cell kinetics and other cellular and humoral immune responses, may play a role in pathogenesis and immunity. At the present time these areas are also totally unexplored in the study of Ostertagia infection. 相似文献
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Immunity to Eimeria infections 总被引:1,自引:0,他引:1
M E Rose 《Veterinary immunology and immunopathology》1987,17(1-4):333-343
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鸡球虫病的免疫防治 总被引:1,自引:0,他引:1
鸡球虫病是一种危害性较大的肠道寄生虫病,多发于3个月以内的仔鸡,尤以15~45日龄的雏鸡最易感染。其发病率高达50%~70%,死亡率为20%~30%.严重者可达80%t~。我国是养鸡大国,每年因球虫病造成的直接和间接经济损失难以估计。迄今为止,鸡球虫病的防治主要依赖药物预防,但是目前药物防治球虫病遇到了两大难题.首先是球虫极易产生耐药性.其次是药物残留,一些国家对禽肉、蛋制品中球虫药物含量有着严格的限制,我国已经加入WTO.解决禽蛋制品的药物残留已成当务之急。因此,利用免疫预防来代替药物防治控制球虫病已成为寄生虫学界的共识。近年来,球虫疫苗的应用进一步完善.为我们防治球虫病提供了一种新的途径.比较好地解决了抗药性和药物残留等问题。 相似文献