蒿甲醚对感染小鼠体内埃及血吸虫超微结构的影响

目的 观察蒿甲醚对小鼠体内埃及血吸虫成虫超微结构的损害。 方法 8只小鼠于感染埃及血吸虫尾蚴后81 d用单剂蒿甲醚400 mg/kg口服治疗。治后24 h、3 d、7 d和14 d各剖杀2只小鼠，用灌注法收集血吸虫，并按常规方法固定和处置虫体，作透射电镜观察。从另2只未治疗的感染小鼠体内取虫作对照。 结果 蒿甲醚对血吸虫皮层超微结构的损害主要是皮层基质的肿胀、溶解和空泡变化，基底膜消失和部份受损皮层破裂；在感觉器和皮层结节中，常见其内部结构广泛溶解。在肌层、实质组织、合体细胞和肠管上皮细胞中，查见局灶性或广泛的溶解、粗面内质网减少及线粒体空泡变化和变性。雌虫卵黄细胞的严重变化是空泡变化、粗面内质网减少、卵黄球融合以及受损卵黄细胞破溃等。上述雌、雄虫变化于感染小鼠用蒿甲醚治疗后24 h即可见到，并逐渐加重，3~7 d后最重。治后14 d，部分雌、雄虫仍示有超微结构的损害，但同时亦观察到受损虫组织的恢复。 结论 蒿甲醚对埃及血吸虫成虫的皮层和皮层下组织具有广泛和严重的超微结构损害。     

蒿甲醚对日本血吸虫超微结构的影响

目的：了解蒿甲醚对日本血吸虫超微结构的影响。方法：小鼠于感染日本血吸虫尾蚴后７或３５ｄ灌服蒿甲醚２００ｍｇ·ｋｇ－１·ｄ－１，连给２ｄ，并于治后１、３、７、１４和２８ｄ剖检取虫体作透射电镜观察。结果：治后１－７ｄ，在虫的皮层、合体细胞、肌束、实质组织、肠管上皮细胞和卵黄细胞等均发现超微结构变化。主要的损害为皮层基质模糊、疏松、溶解和空泡形成；皮层细胞质突起的外质膜模糊、融合、电子密度增加和破溃，以及感觉结构的变性等。皮层下的肌束、合体细胞和肠管上皮细胞可查见广泛的肿胀、溶解和空泡形成。雌虫的卵黄细胞亦示有核空泡变化、粗面内质网减少和卵黄球溶解等。治后１４－２８ｄ，一些存活虫的超微结构变化已恢复，但有的虫仍示有损害。结论：蒿甲醚对７ｄ童虫和３５ｄ成虫的超微结构均有明显影响。     

蒿甲醚对感染小鼠体内埃及血吸虫皮层的损害

目的 评价蒿甲醚对小鼠体内埃及血吸虫皮层的损害作用。 方法 8只小鼠于感染埃及血吸虫尾蚴后81 d，用单剂蒿甲醚400 mg/kg口服治疗。治疗后1、3、7和14 d各剖杀2只小鼠，用灌注法收集血吸虫，并按常规方法固定和处置虫体，作扫描电镜观察。从另2只未作治疗的感染小鼠取虫作对照。 结果 用蒿甲醚治疗后24 h，雄虫的皮层结节肿大、破溃或从皮层上剥落; 在雄虫和雌虫的体表可查见有局灶性或广泛的皮层肿胀、融合、空泡变化、糜烂和剥落，以及感觉结构的破坏。治疗后3 d，雌、雄虫的皮层损害加重，最严重的损害为口吸盘肿胀和破溃，并查见皮层褶嵴有广泛和严重的肿胀、糜烂和剥落，以及雌虫盘状感觉结构的破坏。治疗后7至14 d，有些虫仍示有中或重度皮层损害，而有些仍存活的虫则示其大部分皮层已有明显恢复。 结论 蒿甲醚对埃及血吸虫的皮层具有广泛和严重的损害作用。     

蒿甲醚诱导日本血吸虫雌虫总抗氧化能力下降(英)

目的 观察蒿甲醚对日本血吸虫成虫总抗氧化能力的影响。 方法 体外将血吸虫在含蒿甲醚和氯化血红素的培养液内培养24 h后,或体内感染小鼠经蒿甲醚300mg/kg治疗6～24 h后,测定虫体的总抗氧化能力。 结果体外50μmol/L的蒿甲醚与氯化血红素伍用引起雌虫总抗氧化能力明显下降。体内蒿甲醚作用血吸虫6 h,即见雌虫的总抗氧化能力明显下降。体内、体外试验中,蒿甲醚对雄虫的总抗氧化能力均无影响。 结论 蒿甲醚诱导雌虫总抗氧化能力下降。     

蒿甲醚诱导日本血吸虫雌虫总抗氧化能力下降(英)

目的 观察蒿甲醚对日本血吸虫成虫总抗氧化能力的影响。 方法 体外将血吸虫在含蒿甲醚和氯化血红素的培养液内培养24 h后,或体内感染小鼠经蒿甲醚300mg/kg治疗6～24 h后,测定虫体的总抗氧化能力。 结果体外50μmol/L的蒿甲醚与氯化血红素伍用引起雌虫总抗氧化能力明显下降。体内蒿甲醚作用血吸虫6 h,即见雌虫的总抗氧化能力明显下降。体内、体外试验中,蒿甲醚对雄虫的总抗氧化能力均无影响。 结论 蒿甲醚诱导雌虫总抗氧化能力下降。     

谷胱甘肽抑制蒿甲醚的抗血吸虫作用

目的　观察还原型谷胱甘肽 (GSH)对蒿甲醚伍用氯化血红素抗日本血吸虫作用的影响。　方法　将蒿甲醚、氯化血红素、GSH及谷胱甘肽耗竭剂 2 ,4 -二硝基氯苯 (CDNB)单一或伍用加入含 5周龄血吸虫的培养液内 ,温育2 4 h后 ,测定虫体的丙二醛含量 ,并观察培养至 96 h虫体存活情况。感染小鼠经蒿甲醚 30 0 mg/kg治疗后 6、12或 2 4h,测定虫体的 GSH水平。　结果　体外 ,蒿甲醚伍用氯化血红素作用血吸虫 2 4 h后 ,虫丙二醛含量明显升高。培养时间延长 ,虫陆续死亡。GSH对蒿甲醚伍用氯化血红素诱导血吸虫脂质过氧化及杀虫作用具有拮抗作用 ,CDNB则有增强作用。体内 ,蒿甲醚作用血吸虫 6～ 2 4 h,虫体内 GSH水平先降低再明显升高。　结论　 GSH可能在血吸虫防御蒿甲醚衍生的毒性过氧化物和自由基攻击中起重要作用。     

蒿甲醚在血吸虫病防治中的研究和应用进展

蒿甲醚是青蒿素的衍生物,不仅具有抗疟作用,还有抗血吸虫作用,特别是抗血吸虫童虫,在上世纪末已被发展为预防血吸虫病的药物。该文就蒿甲醚的抗血吸虫作用、抗血吸虫的作用机制、毒性、药代动力学、与吡喹酮联合用药和现场人群应用蒿甲醚预防血吸虫感染的效果及其应用前景等作一简要综述。     

蒿苯酯预防日本血吸虫病的实验研究

本文报道了蒿苯酯预防动物血吸虫病的实验结果。小鼠、免及犬在单次感染日本血吸虫尾蚴后第7d开始服蒿苯酯,每wkl次,连服4-6次,对宿主体内的血吸虫童虫有明显杀灭效果,减虫率达90％—100％,该药对不同感染度小鼠体内血吸虫童虫的杀灭作用相同。对连续感染14d(每d1次)的家兔减虫率亦达93.5％,蒿苯酯皮下注射给药效果比口服好,但毒性大。比较蒿苯酯、呋喃丙胺和吡喹酮3种药物杀灭血吸虫童虫的效果,以蒿苯酯为最佳。同样,蒿苯酯优于其他两种青蒿衍生物一蒿甲醚和还原青蒿素。     

蒿甲醚对曼氏血吸虫的作用:剂量与效应的关系和虫的形态学和组织病理学的变化

目的　应用感染曼氏血吸虫 (利比里亚株 )的小鼠观察蒿甲醚单剂量与效应的关系,虫体肝移及蒿甲醚所引起的虫的形态学和组织病理学变化。　方法　感染21d童虫的小鼠一次口服蒿甲醚12.5mg/kg至600mg/kg不同剂量 ,治后28d剖检观察各组虫数。感染46d或70d成虫的小鼠一次口服蒿甲醚40 0mg/kg后8～14d ,观察虫体肝移及其形态和组织病理学变化。　结果　蒿甲醚对21d童虫的最低有效剂量为200mg/kg ,减虫率为 81%。用蒿甲醚治疗后8h成虫开始肝移,3～7d全部肝移,14d有31%的虫返回肠系膜静脉。成虫虫体萎缩,咽部扩大,肠管膨胀及其色素减少。雌虫局部体表受损,白细胞附着,卵巢及卵黄腺变性退化,以及雄虫睾丸萎缩等。在肝内的虫体被嗜酸粒细胞为主的炎细胞包围和浸润。　结论　蒿甲醚对小鼠曼氏血吸虫21d童虫的最低有效剂量为200mg/kg ,可引起曼氏血吸虫成虫萎缩、退化或死亡。在肝内受损的虫体主要是被嗜酸粒细胞包围和侵袭所致。     

3种青蒿素衍生物对日本血吸虫吡喹酮抗性株童虫的体内作用效果观察

目的观察3种青蒿素衍生物双氢青蒿素、青蒿琥酯和蒿甲醚对日本血吸虫吡喹酮抗性株童虫的体内作用效果。方法以经11轮亚治疗剂量吡喹酮筛选的日本血吸虫为吡喹酮抗性株,以未暴露于吡喹酮的日本血吸虫作为吡喹酮敏感株,收集2虫株尾蚴感染小鼠,以300mg/kg双氢青蒿素、青蒿琥酯和蒿甲醚对感染后7~8 d童虫分别进行2次灌服用药(总剂量600 mg/kg),所有小鼠于感染后45 d解剖,收集小鼠体内成虫并计数,计算减虫率和减雌率。结果 300 mg/kg双氢青蒿素、蒿甲醚和青蒿琥酯2日疗法(总剂量600 mg/kg)对日本血吸虫吡喹酮敏感株7~8 d童虫的减虫率为69.8%~71.0%,减雌率为75.4%~79.8%;对日本血吸虫吡喹酮抗性株7~8 d童虫的减虫率为64.6%~66.1%,减雌率为69.3%~71.1%,差异均无统计学意义(均p0.05)。结论 日本血吸虫吡喹酮抗性株对青蒿素类衍生物双氢青蒿素、青蒿琥酯和蒿甲醚依然敏感,青蒿素衍生物与吡喹酮在日本血吸虫中不存在交叉抗药性。     

Transmission electron microscopic observations on ultrastructural damage in juvenile Schistosoma mansoni caused by artemether.

Artemether, a derivative of the antimalarial artemisinin, has been shown to induce rapid and extensive alteration to the tegument of juvenile Schistosoma japonicum, S. mansoni and S. haematobium. Less is known with regard to ultrastructural damage caused by artemether; therefore, the present work was designed to assess the damage in juvenile S. mansoni. Mice infected with S. mansoni were treated intragastrically with a single dose of 400 mg/kg artemether 21 days post-infection. Between 8 h and 14 days after treatment groups of two mice were sacrificed, and schistosomula recovered for transmission electron microscopic observations. Ultrastructural damage was seen in the tegument, subtegumental musculature, parenchymal tissues and gastrodermis. It was already apparent 8 h after drug administration and increased gradually to reach a peak, 7 days post-treatment. Tegumental alterations were characterised by swelling, vesiculation and degeneration of sensory structures. Damage in subtegumental musculature, parenchymal tissues and gastrodermis included swelling, focal or extensive lysis, and decrease in granular endoplasmatic reticulum. Fourteen days after treatment ultrastructural damage was still seen in most schistosomula, however, there was partial repair in some specimens. The ability of artemether to cause extensive ultrastructural damage to juvenile S. mansoni correlates with its schistosomicidal effects and confirms earlier findings with S. japonicum.     

南京血吸虫扫描电镜观察

目的用扫描电镜观察南京血吸虫体表形态和结构。方法用南京血吸虫的阳性钉螺逸出的尾蚴感染兔,每兔1 200条,感染45-80 d后解剖,获得的血吸虫用4％戊二醛固定。然后按扫描电镜观察要求,清洗、固定、脱水、干燥、镀金,用SX-40扫描电镜进行观察。结果大雄虫背中部体表有粗大的嵴和深的凹陷,腹中部有小棘。小雄虫整个背部和腹部均有小棘。大雌虫体表均有小棘。小雌虫背部和腹面均有小棘,但形状不同,旋转的尾部在同一平面显示出2种体棘;腹吸盘可见轮辐状。雌雄虫体表均可见有纤毛和没有纤毛的感觉乳突。结论南京血吸虫体表存在着与日本血吸虫不同的形态和结构。考虑为一新种血吸虫。     

Ultrastructural alterations in adult Schistosoma mansoni, harbored in non-antihelminthic treated and low-inflammatory mice by transmission electron microscopy (TEM)

This original study suggests that alterations observed on tegumental structure and egg quality of adult Schistosoma mansoni harvested from TS mice are due to their high immune tolerogenic and low-inflammatory capacity. The tegument of worms harvested from genetically selected mice for extreme phenotypes of immune oral tolerance, resistance (TR) and susceptibility (TS) were analyzed by transmission electron microscopy (TEM). Parasites recovered from TR mice showed no tegumental morphological changes. However, specimens collected from TS mice exhibited tubercle swelling with blunted and shortened spines in lower density. These tegumental alterations were similar to those described with artemether or praziquantel treatment, but without to affecting the worm surveillance, supporting observations that the host immune system influences the development and function of the tegument of worms harbored in non-antihelminthic treated TS mice. TS mice showed a higher percentage of dead eggs and a lower percentage of immature eggs than TR mice, but had similar quantities of collected eggs. This suggests that in TS mice the alterations in adult worm tegument prevented egg development, but not egg production or worm survival. These results corroborate our previous scanning electron microscopy (SEM) study indicating the influence of the host immune regulatory profile on the development and function of the worm's reproductive system and tegument.     

甲氟喹单剂口服治疗对小鼠体内日本血吸虫成虫皮层的损害(英文)

目的观察甲氟喹对感染小鼠体内日本血吸虫成虫皮层的损害。方法12只雌性昆明小鼠每鼠感染60～80条日本血吸虫尾蚴,其中10只小鼠于感染后35d用甲氟喹单剂400mg/kg口服治疗,治疗后8h、24h、3d、7d和14d分别剖杀2只,用灌注法收集血吸虫,常规方法固定、逐级乙醇脱水和临界点干燥器干燥,用扫描电镜观察,另2只未治疗的感染小鼠取虫作对照。结果甲氟喹给药后8h,雌、雄虫即示虫体局部肿大,有广泛的皮层褶嵴肿胀、紧密接触和融合,并有少数感觉结构(sensory structure)肿大或部分有破溃。给药后24h,雄虫和雌虫头部高度肿大,并伴有严重的口吸盘损害。给药后3d,虫体普遍出现局部肿大,雌、雄虫的受损皮层融合形成大的块状物,突出于体表,并见局灶性或广泛的皮层剥落,或因肿大的感觉结构破溃形成洞样外观。给药后7d,甲氟喹引起的虫体局部肿大和皮层损害与给药后3d相仿,并见局灶性皮层剥落、肿大,感觉结构的破溃和雌、雄虫口吸盘毁形。给药后14d,个别存活雄虫的虫体仍有轻度局部肿大,但其头部皮层褶嵴正常。结论甲氟喹可引起血吸虫成虫虫体局部肿大和广泛严重的皮层损害。     

肺巨噬细胞对卫氏并殖吸虫后尾蚴损伤作用的超微结构研究

应用扫描电镜和透射电镜观察了卫氏并殖吸虫后尾蚴受肺巨噬细胞损伤后的超微结构改变。后尾蚴与肺巨噬细胞孵育后,表面出现糜烂、肿胀、水泡、皮棘消失,感觉器消失或变形,指状突起变短或消失和外质膜局灶性溶解,基质内出现多层膜包裹的小体;加肺巨噬细胞上清液可致同样的病变。本文结果提示,肺巨噬细胞对后尾蚴有损伤作用,损伤的部位主要在皮层,其机制主要通过肺巨噬细胞分泌的可溶性介质。     

Artemether, an effective new agent for chemoprophylaxis against shistosomiasis in China: its in vivo effect on the biochemical metabolism of the Asian schistosome.

Conventional drug chemotherapy against human schistosomiasis currently relies on treatment with praziquantel to eliminate adult schistosome worm pairs. The use of praziquantel for control purposes is limited, however, by high rates of post-treatment re-infection with subsequent parasite egg deposition and host end-organ damage. Artemether, a methyl ether derivative of the anti-malarial drug quinghaosu, was discovered recently to also have anti-schistosomal properties. Because artemether selectively targets the larval migratory stages of the parasite, known as schistosomulae, it blocks the development of ovipositing adult schistosome worm pairs in the vasculature. On this basis, we have since shown in clinical trials conducted in China that artemether has proven benefit as an agent for chemoprophylaxis. In vivo studies using laboratory animals suggest that artemether causes damage to the tegument and musculature of schistosomulae. Artemether may exert its helminthotoxic effect through synergy with hemin or related heme-containing compounds. Schistosomes recovered from artemether treated laboratory animals have increased glycogen phosphorylase activity, but decreased glucose uptake. These findings may account for their decreased glycogen content, relative to schistosomes recovered from untreated laboratory animals. The artemether-damaged schistosomes also have decreased activities of a number of enzymes and enzyme systems, including glycolysis. This might suggest common pathways by which artemether may target human parasites that live in the bloodstream.     

甲氟喹抗血吸虫及其他蠕虫作用的研究进展

近年来抗疟药甲氟喹,一种氨基乙醇化合物,被发现具有很强的抗血吸虫作用,其特点是对不同发育期的血吸虫童虫和成虫的杀灭作用相仿。本文对近3年有关甲氟喹抗血吸虫和其他蠕虫的实验研究进展进行综述。