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抗病毒药是一类用于预防和治疗病毒感染的药物,在感染细胞或动物体抑制病毒复制或繁殖。病毒是病原微生物中最小的一种,核心含有核酸(核糖核酸RNA或)和复制酶,其外包有的外壳和膜,本身无细胞结构,缺乏完整的酶系统,必须依赖寄主的细胞和酶而繁殖(复制),其复制过程分为吸附(病毒吸附于易感细胞蛋白受体)、入侵(病毒进入细胞)、核酸复制(病毒进入细胞后,脱壳,病毒酸释出,复制核酸。)、病毒酸和结构蛋白合成(装配为完整病毒)等四个阶段。多在其复制繁殖的不同阶段抑制其繁殖所需的酶,从而阻断其复制。病毒学和分子生物学对病毒特异酶、病毒复制过程和抗病毒药物的作用机理已有所阐明,人们不断发现了一些选择性强、特异地作用于病毒的抗病毒药物,已用于治疗较重要的病毒性疾病。 相似文献
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正理想化的抗病毒药物是指能有效地干扰病毒的复制,又不影响正常细胞代谢,但至今还没有一种抗病毒药物可达到此目的。病毒寄生在细胞内,抗病毒药物需通过细胞膜进入细胞而作用于病毒,理想的抗病毒必须是既能防止病毒吸附于宿主细胞表面,又能特异性抑制病毒复制过程中的某些步骤,且不影响机体正常细胞代谢。然而许多代谢过程为病毒和细胞的功能所共有所以很难研制出一种无毒的抗病毒药物。抗病毒治疗前景一片灰暗,我们难道只能束手无策、坐以待毙吗?当我们把目光不再仅仅局限于抗病毒感染治疗、不再仅仅局限于西医、不再仅仅局限于化学合成类抗病毒药物的时候,我们会发现,其实我们的身后, 相似文献
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为体外筛选具有抗猪繁殖与呼吸障碍综合征病毒(PRRSV)的中药单体,本研究选择4味有效的中药单体成分,以Marc-145细胞为靶细胞,从阻断吸附、抑制复制和直接杀灭3个层面进行抗PRRSV研究,以CPE、病毒滴度评价药物抗PRRSV的效果。结果显示,绿原酸和连翘苷可明显抑制PRRSV在细胞内的复制|适当浓度的奎宁酸、绿原酸和连翘苷对PRRSV有较好的直接杀灭效果。综合阻断吸附、抑制复制和直接杀灭效果,绿原酸和连翘苷是理想的抗PRRSV中药单体药物。本研究为猪繁殖与呼吸障碍综合征防控提供了试验依据。
[关键词]猪繁殖与呼吸综合征|中药单体|抗病毒|病毒复制 相似文献
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近年来,禽流感病毒(AIV)在亚洲多个国家的爆发引起了WHO的广泛关注,因此寻求高效低毒病毒治疗药物成为目前研究的重点,许多研究工作表明RNA干扰(RNAi)可以靶向敲降AIV的基因,抑制病毒的复制与增殖,RNAi显示出抗病毒的治疗潜力与良好的应用前景。 相似文献
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猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome, PRRS)是由猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus, PRRSV)引起的烈性、高度接触性传染病,主要引起母猪繁殖障碍和仔猪呼吸道症状。疫苗免疫是防控PRRS的主要手段,但由于PRRSV毒株高度变异性导致疫苗对该病的效果仍不理想。中药(traditional Chinese medicine, TCM)活性成分众多,生理活性多样,包括抗菌、抗病毒和抗氧化等作用,是抗病毒药物的研究热点。研究证明,中药能以单体或复方的方式对PRRSV产生抑制增殖、阻断吸附和杀灭病毒的作用,以及对机体免疫反应产生影响。关于中药抗PRRSV的机制包括直接抗病毒机制和间接抗病毒机制。直接抗病毒机制即中药有效成分对病毒复制周期的直接影响,主要表现为抑制病毒的吸附、内化、复制、大分子组装和释放中的一环,从而达到抑制病毒的作用。间接抗病毒机制即中药有效成分通过调节细胞因子合成、炎症信号通路、细胞凋亡、氧化代谢和免疫系统... 相似文献
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针对猪繁殖与呼吸综合征病毒(PRRSV)JL/07/SW株GP5基因设计了3个RNA干扰靶位,构建shRNA表达质粒;将转染干扰质粒6 h后的MARC-145细胞接种病毒,并通过Real-time RT-PCR、TCID50、CPE、间接免疫荧光检测(IFA)对所设计的shRNA表达质粒的干扰效果进行评价;结果表明,构建的干扰质粒可以高效抑制PRRSV在MARC-145细胞中的复制,说明GP5基因的这3个干扰靶位可能是PRRSV复制所必需的。本试验为PRRSV复制及基因组功能研究、抗病毒药物开发和转基因动物研究奠定了基础。 相似文献
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《畜牧与兽医》2015,(6):93-98
在已知的3种具有较强抗新城疫病毒(NDV)作用的中药成分组方的基础上,利用细胞病变观察与MTT比色相结合的方法,研究这3种组方对NDV吸附DF1细胞及其增殖、释放过程的影响。结果显示:在吸附阻断试验中,3种组方均能阻碍病毒吸附细胞或阻断已吸附上细胞的病毒进入细胞,说明组方浓度、组方加入方式和病毒吸附时间均能够影响病毒对细胞的感染;在复制抑制和病毒释放阻断试验中,测定的试验组OD570值显著高于相应的病毒对照组,说明3种组方均能够抑制病毒的增殖和阻碍病毒的释放。结果表明,3种组方能够阻断NDV吸附细胞和/或干扰病毒的增殖和释放而表现抗病毒作用。 相似文献
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<正>抗病毒药物是一类用于预防和治疗病毒感染的药物。在体外可抑制病毒复制酶,在感染细胞或动物体抑制病毒复制或繁殖,在临床上治疗病毒病有效的药物。病毒与细菌不同,缺乏自身繁殖的酶系统,因而它是细胞内寄生的微生物,依赖宿主细胞代谢系统进行生殖复制。 相似文献
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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
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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
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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
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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
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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