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81.
82.
T.G. Burrage W.W. Laegreid 《Comparative immunology, microbiology and infectious diseases》1994,17(3-4):275-285
African horsesickness (AHS) is a serious, non-contagious disease of horses and other solipeds caused by an arthropod-borne orbivirus of the family Revoiridae. In horses, AHS causes three distinct clinicopathologic syndromes, the pulmonary, cardiac and fever forms of the disease. Recent work has shown that the primary determinant of the form of disease expressed by naive horses is the virulence of the virus inoculum. Horses which recover from AHS exhibit solid humoral immunity against homologous challenge. Protective antibodies appear to be directed towards neutralizing epitopes on AHS virus VP2. The relationship of neutralization to protection and vaccination is discussed. 相似文献
83.
An 8-week-old male moose calf was inoculated with 360 infective third-stage larvae (L3) of E. cervi. The calf started to expel first-stage larvae (L1) of E. cervi in faeces 63 days after inoculation. The highest faecal larval count of 1,920 L1 per gram faeces was recorded 133 days post inoculation. Clinically, intermittent lameness, mild ataxia and general stiffness were observed over a 3 months’ period from day 75 after inoculation. The symptoms were moderate, faded gradually and were not seen during the last three weeks of the observation period. The calf had a good appetite and the bodyweight increased continuously throughout the experiment. On day 202 after inoculation the calf was euthanized and autopsied. Adult E. cervi were found in the epidural space of the central nervous system (CNS) and in skeletal muscles. Oedema, haemorrhages, discolouration and extensive inflammatory reactions were observed in the fat and loose connective tissue of the epidural space between the 5 th cervical vertebra and cauda equina. Nematodes or lesions indicating nematode infestation could not be demonstrated in the leptomeninges or in the neural parenchyma of the CNS. Numerous eggs and larvae of E. cervi associated with moderate pathological changes were observed in the lungs. 相似文献
84.
Rift Valley fever(RVF) virus is an arbovirus in the Bunyaviridae family that, from phylogenetic analysis, appears to have first emerged in the mid-19th century and was only identified at the beginning of the 1930's in the Rift Valley region of Kenya. Despite being an arbovirus with a relatively simple but temporally and geographically stable genome, this zoonotic virus has already demonstrated a real capacity for emerging in new territories, as exemplified by the outbreaks in Egypt (1977), Western Africa (1988) and the Arabian Peninsula (2000), or for re-emerging after long periods of silence as observed very recently in Kenya and South Africa. The presence of competent vectors in countries previously free of RVF, the high viral titres in viraemic animals and the global changes in climate, travel and trade all contribute to make this virus a threat that must not be neglected as the consequences of RVF are dramatic, both for human and animal health. In this review, we present the latest advances in RVF virus research. In spite of this renewed interest, aspects of the epidemiology of RVF virus are still not fully understood and safe, effective vaccines are still not freely available for protecting humans and livestock against the dramatic consequences of this virus. 相似文献
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86.
Marcelo HAF Mendes Maria HB Pinto Eduardo J Gimeno Claudio G Barbeito Fabiano JF de Sant'Ana 《Reproduction in domestic animals》2019,54(10):1366-1374
The lectin histochemical pattern (LHP) was characterized and compared in normal and cystic ovaries of sows. Six biotinylated lectins (PNA, SBA, WGA, RCA‐1, DBA and UEA‐1) were used on tissue sections. In the normal ovaries, the reaction to UEA‐1 and SBA was mild to moderate in mesothelial and endothelial cells. RCA‐1 staining was mild to moderate in theca interna of growing follicles, corpora luteum and mesothelium. In addition, this lectin presented strong reaction in endothelial cells, granulosa cells of atretic follicles, zona pellucida of growing follicles and plasma. DBA showed strong intensity in mesothelial and endothelial cells. There was mild to moderate reactivity to WGA in granulosa cells, corpus luteum and theca interna of follicles in development, and moderate in zona pellucida, in granulosa cells of atretic follicles and mesothelium. PNA staining was mild to moderate in oocytes and in the adventitia and media of medullary arteries. Changes in the LHP of the cystic ovaries were noted; however, there were no differences in these findings between the follicular and luteinized cysts. UEA‐1 reactivity in the cystic ovaries was moderately reduced in the mesothelial and endothelial cells, whereas there was mild reduction in the DBA staining in the granulosa cells. Reaction to RCA‐1 and WGA in the cysts also was decreased in theca interna, zona pellucida and granulosa cells of atretic follicles. Furthermore, endothelium and theca interna in the cystic ovaries presented mild reduction of marcation to SBA, whereas there was decreased reactivity to PNA in the oocytes and adventitia and media layers of the medullary arteries. The results of the current study show that cysts modify the LHP in swine ovaries. These changes of glycoconjugates in many ovarian structures could modify diverse process and may be one of the reasons for decreased fertility in sows. 相似文献
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88.
革兰氏阴性菌外膜蛋白研究进展 总被引:14,自引:0,他引:14
外膜蛋白对细菌本身和宿主都具有重要的作用。本文综述了革兰氏阴性菌外膜蛋白的组成、结构、功能及遗传调控,外膜蛋白可作为大肠杆菌的克隆标志,在细菌的致病机理及免疫机理中都有重要作用,研制开发外膜蛋白疫苗具有广阔的应用前景,必将为细菌性疾病的防治提供有力的措施。 相似文献
89.
细胞凋亡与细胞坏死比较的研究进展 总被引:5,自引:0,他引:5
本文对细胞凋亡和细胞坏死的发病机理和病理形态学进行了比较。凋亡是细胞的一种主动性死亡。其特点是单细胞发生,胞核浓缩、破裂,核碎块被胞膜包裹,形成特异性“凋亡小体”;细胞器多以萎缩变化为主。坏死则为细胞的被动性死亡,并常伴有炎症反应。作者认为:细胞凋亡和坏死虽然在发生机制和病理形态学方面有所区别,但它们的本质却是相同的,均为细胞的一种不可复性的退行性变化。 相似文献
90.
The Hydropericardium Syndrome in Poultry – A Current Scenario 总被引:2,自引:0,他引:2
Inclusion-body hepatitis hydropericardium syndrome (IBH-HPS) is an important, recently emerged, disease of poultry, particularly of 3- to 6-week-old broiler chicks, characterized by its sudden onset, with high mortality ranging from 20% to 70%, typical hydropericardium and enlarged mottled and friable livers, with intranuclear inclusion bodies in the hepatocytes. The causative agent is a non-enveloped icosahedral fowl adenovirus (FAV) serotype 4, belonging to the Adenovirus genus of the family Adenoviridae, which can be propagated or cultivated in chicken embryo liver and kidney primary cell cultures. The transmission of disease occurs vertically and laterally by the oral-faecal route. The liver of infected birds shows necrotic foci and basophilic intranuclear inclusion bodies in the hepatocytes. The disease can be diagnosed from its gross and histopathological changes in the liver and by various serological tests, such as agar gel immunodiffusion, counterimmunoelectrophoresis, indirect haemagglutination, the fluorescent antibody technique, enzyme-linked immunosorbent assay and the polymerase chain reaction. The disease has been brought under control by the use of formalin-inactivated vaccines, prepared from infected liver homogenate, and of inactivated cell culture vaccines. The vaccines are effective in the face of natural outbreaks or experimental challenge and significantly reduce the mortality. 相似文献