共查询到20条相似文献,搜索用时 46 毫秒
1.
鸡传染性贫血病毒是鸡传染性贫血病的病原体,能引起雏鸡贫血、淋巴组织萎缩、出血及免疫抑制,是导致许多疫苗免疫失败及雏鸡死亡的主要原因之一。该病毒在世界范围内广泛存在,是养鸡业潜在的巨大威胁。近年来的研究表明,鸡传染性贫血病毒主要是通过其编码的凋亡素诱导雏鸡胸腺和骨髓中的造血祖细胞凋亡而致病的,而凋亡素诱导细胞凋亡的能力与其在细胞中的核定位及半胱氨酸蛋白酶(caspase)等因素密切有关。文章就鸡传染性贫血病毒生物学特征、诱导细胞凋亡的现象及机制的研究进行了综述。 相似文献
2.
3.
4.
《山东畜牧兽医》2016,(12)
正鸡传染性贫血病(CIA)是由鸡传染性贫血病毒(CIAV)引起的一种使能使感染鸡再生障碍性贫血、淋巴组织萎缩、出血的病毒性传染病。鸡传染性贫血病(CIA)主要发生于2~4周龄的雏鸡,导致雏鸡贫血和成鸡的免疫抑制。目前,鸡传染性贫血病对养鸡业的危害不断上升,已引起世界各个养禽国家的广泛关注,如何有效的进行防治成为一大热点,本文就近些年鸡传染性贫血病(CIA)的研究进展及防治措施做一综述。鸡传染性贫血病是由圆环病毒科(Circoviridae)陀螺病毒(Gyrovirus)属的鸡传染性贫血病毒(Chicken infectious anemia virus,CIAV)引起的,临床上以贫血、骨髓黄染、全身淋巴组织萎缩和免疫机能损害为主要特征。1979年 相似文献
5.
6.
7.
鸡传染性贫血病的防制 总被引:1,自引:0,他引:1
鸡传染性贫血病(CIA)是由鸡传染性贫血病毒(CIAV)引起的主要以雏鸡再生障碍性贫血和全身性淋巴组织萎缩为主要特征的免疫抑制病.该病在临床上主要导致雏鸡的生长发育不良、渗出性皮炎和死亡,又称为蓝翅病、出血性综合征和贫血性皮炎综合征等,其引起感染鸡的免疫抑制常常导致其他病原微生物的继发感染,常常给养鸡业造成严重的经济损失. 相似文献
8.
鸡传染性贫血(CIA)是由鸡传染性贫血病毒(CAV)引起的一种以再生障碍性贫血和淋巴器官组织萎缩为主要特征的免疫抑制病.崔现兰(1992)首次于我国东北地区分离到该病毒[1],目前在我国许多地方都有该病毒的报道.CAV侵入雏鸡体内后,主要作用于骨髓和胸腺等淋巴器官,导致感染鸡出现再生障碍性贫血及胸腺等淋巴器官严重萎缩,产生免疫抑制,对禽病疫苗的免疫应答机能降低,甚至丧失.为研究鸡传染性囊病病毒对鸡传染性囊病活疫苗(Gt株)免疫效果的影响,本试验采用人工感染CAV的方法研究CAV感染对鸡传染性囊病活疫苗(Gt株)免疫效果的影响. 相似文献
9.
鸡传染性贫血病是以雏鸡再生障碍性贫血和全身淋巴组织萎缩为主要特征,由鸡传染性贫血病毒(CAV)引起的鸡传染病,1979年由Yuasa等首次在日本发现,此后在世界许多国家包括中国相继证明了该病的发生.由于该病的垂直和水平传播引起的临床和亚临床感染给世界养禽业造成较大的经济损失,目前该病已列入世界许多范围内重要禽病研究的行列. 相似文献
10.
鸡传染性贫血(chicken infectious anemia,CIA)是由鸡传染性贫血病毒(chicken anemia virus,CAV)引发,自1979年日本学者Yuasa等[1]分离到了鸡传染性贫血病毒以来,英国、德国、澳大利亚、美国等世界许多国家相继证明了该病毒的存在,我国亦于1992年由崔现兰等[2]分离到CAV.CAV在1995年的第6次国际病毒分类委员会维也纳会议报告中被归为圆环病毒科(circoviridae),环状病毒属[3].游离CAV为DNA病毒,球形,直径约23~25 nm,无囊膜,二十面体对称,是目前已知的最小病毒之一.CIA以引起雏鸡再生障碍性贫血和免疫抑制为主要特征,严重影响雏鸡生长发育和免疫反应,是危害养禽业的重要病原之一. 相似文献
11.
12.
13.
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
14.
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
15.
16.
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
17.
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
18.
19.
20.
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