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1.
一氧化氮抗寄生虫感染的研究进展 总被引：4，自引：1，他引：3
一氧化氮 (NO)在寄生虫感染过程中具有抑制或杀伤寄生虫与对宿主机体产生病理损伤的双重作用。机体内 NO的产生及抗寄生虫作用受细胞因子严格调节 ,巨噬细胞经 IFN-γ等细胞因子或脂多糖 L PS刺激后能大量表达 i N-OS,产生的 NO对球虫、弓形虫、锥虫、疟原虫、肝片吸虫、血吸虫等均有杀伤作用 ,NOS抑制剂的阻断则进一步表明 NO在寄生虫感染中的重要作用。近年来 ,关于 NO抗寄生虫感染、作用机制、NO合酶抑制剂和细胞因子影响等的研究报道日渐增多。文章就有关研究进展进行了综述 相似文献
2.
一氧化氮合酶与寄生虫感染 总被引：4，自引：0，他引：4
一氧化氮(NO)在体内由L-精氨酸在一氧化氮合成酶(NOS)的催化下生成。它是一种重要的信使分子,参与血管、气道平滑肌的调节,神经递质的传递,细胞杀伤,肿瘤细胞的溶解及内分泌激素的释放过程,与许多疾病的发生、发展密切相关;既在机体多个系统多种细胞中具有广泛的生理功能,又可能参与多种疾病的发生过程。寄生虫感染时,动物机体内由其诱发产生各种细胞因子。细胞因子激发一氧化氮合酶基因,其转录产生iNOS(induciblenitricoxidesynthase)mRNA,由iNOSmRNA指导一氧化氮合酶(iNOS)生成。iNOS以精氨酸为底物合成NO。本文就NOS的结构、生成和NO对寄生虫的作用以及影响NO抗寄生虫感染的因素作了综述。 相似文献
3.
近年来许多研究表明一氧化氮(NO)在抗寄生虫感染过程中发挥着重要的作用,其作用更多受到一氧化氮合酶(NOS)的影响。利用NO供体来模拟NO的活性是研究NO作用的一个重要手段。NO抑制寄生虫感染的机理十分复杂,既有直接作用,也有间接和免疫协同作用等多个作用。本文就NO的生物学特性、作用机制及其抗寄生虫感染的关系和影响因素等方面做一简要概述。 相似文献
4.
不同剂量柔嫩艾美耳球虫感染对雏鸡脾重与血清NO含量的影响 总被引：2，自引：0，他引：2
近年来，球虫免疫的研究成为一个热点，诸多实验结果表明，脾脏和体内的NO在寄生虫感染和免疫过程中发挥重要的作用。早在1990年Green就提出，巨噬细胞和肝细胞内受细胞因子诱导生成的NO属于由细胞内感染引发的非特异免疫机制。本研究以人工感染发病的方法，研究了不同剂量的柔嫩艾美耳球虫在感染雏鸡后的第5、7、10、14天脾脏相对重量和血清中的一氧化氮的变化情况，以揭示脾脏和一氧化氮在抗球虫感染中所发挥的作用，为鸡球虫的非特异性免疫防治提供依据。 相似文献
5.
宿主感染寄生虫的一个显著表现是在感染期间不能发生有效的免疫反应。花生四烯酸代谢物可能在这一现象中起重要作用。大量的研究证据表明，寄生虫释放花生四烯酸代谢物；寄生虫花生四烯酸代谢物抑制宿主免疫细胞功能，从而有利于寄生虫的入侵和生存；寄生虫也激发宿主细胞产生花生四烯酸代谢物。 相似文献
6.
肠道寄生虫与菌群互作关系研究进展 总被引：1，自引：1，他引：0
肠道菌群是动物机体的重要组成部分，与寄生虫和宿主的关系十分密切。寄生虫感染往往会对宿主产生不利影响，其致病作用与寄生虫种类、寄生部位及其与宿主的相互作用有关。寄生虫感染可导致肠道微生态的改变、失调和炎症性疾病；肠道菌群也影响寄生虫在宿主体内的定植、增殖和毒力。肠道寄生虫包括寄生蠕虫和原虫，近年来对肠道寄生虫与菌群相互作用研究发现，无论是原虫还是蠕虫感染均可导致肠道微生物组成和多样性的改变，对宿主产生致病作用，而蠕虫对炎症性肠病的潜在治疗作用一度颠覆了以往人们对于寄生虫的认知。肠道菌群可促进或抑制寄生虫对宿主的致病作用，且益生菌对肠道寄生虫感染有一定的预防或治疗作用。目前对寄生虫与菌群相互作用的研究仍然处于初期阶段，对其相互作用的机制尚不清楚。明确寄生虫与肠道菌群的相互影响及其作用机制，对深入理解寄生虫－肠道菌群－宿主的相互关系、研发有效的抗寄生虫微生态制剂具有重要意义。作者就近年来肠道蠕虫和原虫与菌群相互作用的研究进展进行了综述，并对该领域未来的研究方向进行展望，以期为预防和控制寄生虫病提供新的策略和理论依据。 相似文献
7.
李细林 《江西畜牧兽医杂志》2006,(6):41-42
当前,寄生虫在猪场的感染十分普遍,给猪场的造成的损失也非常明显,不同规模的大小猪场均存在较高程度的寄生虫感染。有报道证明,猪的体内寄生虫感染率达90%以上,体外寄生虫感染几乎100%。寄生虫的感染直接造成猪体瘦弱、生长缓慢、死胎、饲料利用率降低,传播疾病。1流行情况及症状引起猪群感染的寄生虫种类主要有疥螨、虱、蛔虫、鞭虫、食道口线虫等,其中以疥螨和蛔虫的危害最为普遍也最为严重。1.1疥螨感染最初是耳部皮屑脱落,进而导致过敏性皮肤丘疹,逐渐蔓延至背部、躯干两侧及后肢内侧,严重时出血、结缔组织增生和皮肤增厚,引起采食量减… 相似文献
8.
生长激素是一种重要的垂体激素,主要参与身体生长和新陈代谢。在哺乳动物,克氏锥虫感染急性期的控制主要依赖于巨噬细胞活化细胞因子,为探索生长激素是否可有效治疗恰加斯病,试验研究了生长激素对克氏锥虫感染鼠的治疗效果,重点分析了其对寄生虫血症,NO、TNF-a、IFN-c浓度,心肌组织病理学变化及寄生虫负荷的影响。克氏锥虫雄性Wistar感染鼠每日腹腔注射生长激素,注射剂量为5ng/10g体重。与未处理组小鼠相比,生长激素处理组小鼠在感染急性期的血液锥虫数量显著减少(P0.05)。在试验感染急性期(感染后7、14、21d),与未处理组小鼠相比,生长激素处理组小鼠的NO、TNF-a、IFN-c浓度显著升高(P0.05)。心肌组织病理学观察结果表明,注射生长激素可减轻无鞭毛体负荷,减少炎性渗透和组织结构破坏。结果表明,生长激素可作为免疫调节剂来控制寄生虫复制,可与现用药物联合使用以减少恰加斯病的危害。 相似文献
9.
舍饲肉羊感染寄生虫主要分为内寄生虫感染,如片型吸虫、消化道线虫和体表寄生虫感染,如虱、螨、蜱等。内寄生虫可导致羊贫血、消瘦、局部水肿、下痢、流产等。外寄生虫以吸食羊血为主,使病羊瘙痒、不安,影响采食、休息,导致皮肤发炎和消瘦。1疥癣病 相似文献
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11.
文章介绍了我国塔里木盆地的驴资源和驴用途,以及当前发展养驴业在新疆的重要意义。同时概述了我国驴的福利和健康问题,以及部分国内外对驴寄生虫的研究成果。建议应从流行病学调查为起始点,首先掌握塔里木盆地驴寄生虫的流行规律,为驴寄生虫病的科学防控提供依据。 相似文献
12.
Kaio César Simano Tavares Patricia Wolkmer Luiz Claudio Miletti 《Research in veterinary science》2011,90(2):257-259
Cryopreservation is a method of keeping parasites alive in a laboratory. However, this technique may also damage the parasite. Alternatively, parasites may be maintained by in vitro culture. Unfortunately, for Trypanosoma evansi no effective medium that is able to maintain the parasite for more than 4 months has been described. In this study, we examined the effect of purifying trypomastigote through DEAE-cellulose chromatography before and after cryopreservation, by analyzing the pre-patent period, longevity, parasitemia, and count of viable parasites. Our results showed a three-times increase in the concentration of viable trypomastigote in DEAE-purified cryopreserved parasites as compared to non-DEAE-purified cryopreserved parasites. This indicates that DEAE-cellulose chromatography followed by cryopreservation is an effective method for the storage and preservation of T. evansi, with the advantage that the stocked parasites will be ready to use in molecular biology procedures. 相似文献
13.
目的为了摸清安徽省淮南市毛集区山羊消化系统寄生虫病的流行及危害情况，有效的指导该区山羊消化系统寄生虫病的防治工作。方法选取3个调查点，收集山羊的新鲜粪便，采用饱和盐水漂浮法和尼龙筛兜淘洗法获取虫卵，显微镜下进行形态学鉴定，并计算感染强度。根据检查结果，选择药物进行驱虫，观察驱虫效果。结果该区山羊消化系统寄生虫总感染率为100％（47／47），所获寄生虫8种，隶属于3门3纲3目5科8属，即：血矛属（Haemonchus），毛圆属（Trichostrongylus），奥斯特属（Ostertagia），古柏属（Cooperia），艾美耳属（Eimeria），食道口属（Oesophagostomum），仰口属（Bunostomum），莫尼茨属（Moniezia）。根据调查结果采用丙硫咪唑和氯苯胍进行驱虫试验，并对驱虫前后山羊消化系统寄生虫的感染情况进行了分析。结论安徽省淮南市毛集区山羊消化系统寄生虫病感染率较高，采用药物驱虫可以获得较好效果。 相似文献
14.
Karanis P 《DTW. Deutsche tier?rztliche Wochenschrift》2000,107(8):311-315
Human- and veterinary important parasites of the subkingdom of protozoans and helminths infect humans and animals by ingestion of parasites in contaminated water. The parasites are excreted from the body of infected humans, livestock, zoo animals, companion animals or wild animals in the feces. Recreational waters, agricultural practices and wild animals serve as vehicles of transmission of the parasites in the water supplies. The following topics are addressed: a) the life cycles of parasitic diseases-causing agents with proven or potential transmission via water b) the development and the current research status of the analytical techniques for the detection of parasitic diseases-causing agents from water c) the occurrence of Cryptosporidium and Giardia in surface water supplies and in treated water d) the possible water sources and transmission ways of the parasites into the water supplies e) the behaviour and the possibilities for the removal or elimination of the parasites by water treatment. 相似文献
15.
This report describes a remarkable histopathological presentation of a symptomatic dog naturally infected with Leishmania (Leishmania) chagasi from Brazil. An intense inflammatory granulomatous reaction was observed in the liver and spleen associated with hypertrophy and hyperplasia of the mononuclear system (the classical histopathological picture of the disease). In addition, a spectrum of vascular lesions was observed in many organs. However, we did not find parasites (amastigotes of Leishmania) in any skin fragments of the ear, nose and or abdominal tissue. In fact, this animal had severe clinical signs, showed parasites in many organs, but no parasites in the skin. It appears that the presence or absence of parasites in the skin is not a good indicator of parasites in other organs or vice versa. 相似文献
16.
Factors contributing to the public health and economic importance of waterborne zoonotic parasites 总被引：1，自引：0，他引：1
This is the first of a series of review articles in a Special Issue publication on waterborne zoonotic parasites. A brief historical overview of the occurrence and importance of waterborne parasites, dating from early civilization is presented. The article considers the diversity of parasites including protozoa, nematodes, cestodes and trematodes and the related zoonotic organism microsporidia. Many of the life cycle stages and their characteristics, which make parasites environmentally resistant and suitable for waterborne transmission are discussed. Surfaces of transmission stages consist of multiple layers of proteins, lipids, chitin or other substances capable of withstanding a variety of physical and chemical treatments. Delivery of waterborne parasites is facilitated by various mass distribution systems to consumers, and by transport and intermediate hosts such as fish and filter-feeding invertebrates which are consumed by humans. The article discusses the trends in global warming and climate change and potential for concurrent rise in waterborne disease outbreaks due to parasites. Impacts of technological modernization and globalization on the transmission of zoonotic waterborne zoonotic parasites are considered, including the effects of large-scale agricultural practices, rapid transportation of goods, and widespread movement of individuals and animals. Finally, transmission features and parasite attributes which contribute to concerns about accidental or orchestrated waterborne disease outbreaks are discussed. 相似文献
17.
Y Omata T Kawano T Ohsawa S Sugaya M Satake T Isamida T Koyama A Taka K Miyazawa M Takagi A Saito Y Toyoda 《Veterinary parasitology》1999,82(3):211-215
The infectivity of the feline enteroepithelial stages of Toxoplasma gondii isolated by Percoll-density gradient centrifugation was examined by the trypan blue dye exclusion method by assaying their penetration into feline fibroblast cells in vitro and by inoculation of the intestinal mucosa of cats. A large population of the parasites showed trypan blue dye exclusion activity. When feline fibroblast cells were inoculated with feline enteroepithelial stage parasites, no intracellular parasites were found 18 h post-inoculation. Kittens inoculated intraduodenally with 2 x 10(6) feline enteroepithelial stage parasites shed oocysts between 2 and 8 days post-inoculation. These results indicate that the isolated feline enteroepithelial stage parasites display infectivity towards enterocytes of cats and are capable of gametogenesis. 相似文献
18.
An effort was undertaken to replace a community of sheep endoparasites that had been classified as resistant to levamisole and albendazole with a community of more susceptible parasites using a dilution approach that could be integrated into the management of a commercial flock. For this study, pastures on this sheep farm were divided into two areas: north and south. Strategically timed anthelmintic treatments combined with pasture management reduced to nondetectable levels the endemic community of anthelmintic resistant parasites in this flock and on these pastures by early summer. A group of 102 ewes, lambs, and rams were experimentally infected with third stage larvae from the more susceptible community of parasites. These sheep then seeded the south pastures with the new parasite community, while sheep on the north pastures maintained the endemic resistant community. Despite its insensitivity as a technique for detecting anthelmintic resistance, fecal egg count reduction tests at the end of the grazing season indicated that the more susceptible parasites were present on the south pastures while resistant parasites were present on the north.The following grazing season, similar protocols were used to introduce the more susceptible parasites onto the north pastures. At the end of the grazing season, fecal egg count reduction tests indicated that the new community of parasites had become established on both groups of pastures of the farm. 相似文献
19.
本次对广州地区某羊场山羊的体内外寄生虫进行了调查,通过体表、粪便检查以及尸体剖检发现;体外寄生虫有山羊蚧螨和山羊毛虱;体内寄生虫有寄生于第四胃和小肠物毛圆科线虫,包括血矛线虫属、毛圆属、奥斯特属、马歇尔属、古柏属多种线虫。采用害获灭和螨净对以上寄生虫进行治疗试验。发现害获灭对山羊螨、虱及胃肠道线虫都有较好的驱杀作用。其中对胃肠道线虫的驱净率达１００％,某此螨病较为严重的山羊采用害获灭肌注,同时配合 相似文献
20.
W I Morrison 《Veterinary parasitology》1987,25(2):163-176
The first part of this presentation considers some of the complexities of parasitic infections and parasite-specific effector mechanisms which have hampered the development of practical methods of immunisation against parasitic diseases. In the second part, an outline is given of the effector mechanisms involved in immunity of cattle to the protozoan parasite Theileria parva. Parasites are antigenically complex organisms which often have distinct developmental stages, sometimes with different predilection sites within the host. Antigenic polymorphism between strains is a common feature of parasites and sometimes results in strain-specific immunity. Certain parasites have also evolved mechanisms of modulating surface antigens which allow them to escape host effector mechanism. Effector mechanisms which control parasitic infections may operate by preventing establishment of the parasites, by eliminating the parasites once they have established or by affecting growth or fecundity of the parasites. In addition to specific antibody and cell-mediated immune responses, inflammatory or physiological responses play an important role in the control of some parasites. Current evidence suggests that effector mechanisms against T.parva parasites operate at two levels. First, antibodies produced against the infective stage of the parasite, the sporozoite, can, by neutralising infectivity, reduce the numbers of organisms which establish in the host. Second, cytotoxic T cells directed against parasitised lymphoblasts cause destruction of parasites following their establishment in the host. Moreover, in situations where immunity is parasite strain-specific, the cytotoxic T cell responses have also been found to be strain-specific. The elucidation of these effector mechanisms has indicated potential new strategies of immunisation against T.parva. 相似文献