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伪狂犬病病毒吉林分离株感染BHK-21细胞的超微结构变化   总被引:1,自引:0,他引:1  
以猪伪狂犬病病毒(PRV)吉林分离株PRV-JL感染体外培养的BHK-21细胞为模型,通过透射电镜对PRV的形态发生学和宿主细胞超微结构的动态变化规律进行研究。结果显示,PRV能导致BHK-21细胞圆缩,并发生细胞融合,形成合胞体;电镜观察到的病毒粒子呈球形或椭圆形,成熟的病毒粒子直径大小为140~210 nm,未成熟病毒粒子直径为90~150 nm,多呈中空状,部分呈致密核芯。病毒吸附于细胞后以膜融合的方式进入细胞,在胞核内复制,装配好的病毒粒子以出芽的方式离开细胞核,获得最初的囊膜,进入胞浆;在胞浆内的病毒粒子又利用高尔基体的膜结构合成第2层囊膜,形成完整的病毒粒子;最后包裹有完整病毒粒子的高尔基囊泡与细胞膜发生融合,将病毒粒子释放到细胞外。感染细胞超微结构变化主要表现为:细胞胞浆空泡增多,内质网扩张,线粒体增生、嵴肿胀、脱落,最后空泡化,整个细胞裂解、破碎。  相似文献   
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Altered excitability of the skeletal muscle membrane (sarcolemma) can result in clinical signs of muscle dysfunction. Hyperexcitability of the sarcolemma results in myotonia, and hypoexcitability results in paresis or paralysis. Our understanding of the physiologic and molecular bases of disorders of sarcolemmal excitability is rapidly increasing as techniques for evaluation are improved. This article reviews muscle excitability disorders in dogs and cats and their pathogenesis.  相似文献   
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The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.  相似文献   
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Cucumber mosaic cucumovirus (CMV) has been the most serious pathogen of tomato in Greece for the last 15 years, causing tomato shrinkage, tomato necrosis and tomato fruit necrosis. In an epidemiological study in Eleia county, one of the main centres of production of processing tomato in Greece and one most affected by CMV, it was confirmed that the virus had an extremely high frequency. Disease frequency and severity was found to have a patchy spatial and temporal distribution at county, zone and locality level, during the years and within 1998, the main year of experimentation (and a disastrous year for CMV). Great variation was found in the trends of infection frequencies during the growing season of 1998 in the 15 experimental fields but all were finally 100% or almost 100% infected. The trends of infection frequency in these 15 fields paralleled total captures of alate aphids by a Rothamsted‐type trap, whereas in one of these fields, with a Moericke‐type trap, these parallel captures were composed almost exclusively of Aphis spiraecola.  相似文献   
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采用文献计量学方法,从论文分布、作者分布、发表论文的机构和地区分布、基金资助 等方面对1997-2006年中国期刊全文数据库收录的有关核心期刊研究的论文进行了统计分析 ,对其研究现状和发展趋 势进行探讨,指出了我国有关核心期刊研究的一些不足,并提出了相应的对策。

  相似文献   
49.
家蚕对8种除草剂农药的毒性反应   总被引:5,自引:0,他引:5  
近年来农资部门和植保部门出售的除草剂品种繁多,新药不断出现,有许多除草剂在大田作物和桑园中使用,这些除草剂农药对家蚕的毒性如何?笔者等近年来做了大田常用除草剂农药对家蚕的毒性试验,本文报道8种除草剂对家蚕的触杀毒力、安全间隔期及中毒症状,以便为蚕农科学用药提供依据。 1 材料与方法 1.1 供试农药 市售41%农达水剂(美国孟山都公司),72%2,4-D丁酯水剂(河北万全农药厂),盖草能(中国农业生产资料集团公司分装),2%使它隆乳油(美国陶氏益农公司),20%克无踪水溶液(英国卜内门化学工业有限公司),50%高特克悬浮剂(德国艾格福公司),50%扑草劲可湿性粉剂(昆明农药厂)和10%新代力可湿性粉剂(浙江省乐清市乐吉化工厂)共8种。 1.2 供试蚕品种 春季781×782*734,秋季苏3*秋3×苏4*苏12,由省农科院蚕研所春用组提供。 1.3 试验地点及桑品种 在本所生理病理室和桑树研究室进行,6年生油桑品种,低干养成,7500株/ha  相似文献   
50.
Seasat and Geosat satellite altimeter measurements for the Greenland ice sheet (south of 72 degreesN latitude) show that surface elevations above 2000 meters increased at an average rate of only 1. 5 +/- 0.5 centimeters per year from 1978 to 1988. In contrast, elevation changes varied regionally from -15 to +18 centimeters per year, seasonally by +/-15 centimeters, and interannually by +/-8 centimeters. The average growth rate is too small to determine if the Greenland ice sheet is undergoing a long-term change due to a warmer polar climate.  相似文献   
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