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。     

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。     

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。     

低剂量吡喹酮对日本血吸虫皮层损害扫描电镜观察

感染日本血吸虫的家兔1次口服30～40mg/kg低剂量吡喹酮后24h取虫,应用扫描电镜观察,发现药物对虫体的口、腹吸盘结构无影响,但可使其皮层发生褶嵴肿胀、溃破、糜烂和剥落等严重损害。各治疗组皮层损害程度,雌虫较雄虫严重,尤以40mg/kg组更为显著。     

左旋吡喹酮与右旋吡喹酮治疗对体内日本血吸虫皮层损害的扫描电镜观察(英文)

感染日本血吸虫３５ｄ的小鼠用左旋吡喹酮（Ｌ－Ｐｒａ）１５０ｍｇ·ｋｇ－１，或右旋吡喹酮（Ｄ－Ｐｒａ）１５０、６００ｍｇ·ｋｇ－１１次灌胃治疗，在给药后的１５ｍｉｎ，１、２、４、８、２４ｈ分别解剖取虫，以扫描电镜观察血吸虫的皮层变化。结果，发现，Ｌ－Ｐｒａ１５０ｍｇ·ｋｇ－１对血吸虫可引起明显和广泛的损害，包括皮层的严重肿胀、融合、糜烂和剥落，并伴有宿主白细胞的粘附；盘状感觉器官亦示有明显的肿胀、变形和破溃。用Ｄ－Ｐｒａ１５０ｍｇ·ｋｇ－１治疗的血吸虫皮层损害轻微。如剂量增至６００ｍｇ·ｋｇ－１，虫的皮层损害与Ｌ－Ｐｒａ１５０ｍｇ·ｋｇ－１引起的相似，但程度较轻。结果认为，吡喹酮的２种旋光对映体对血吸虫的药理作用虽极为相似，但右旋吡喹酮的作用较左旋吡喹酮的为差。     

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。     

蒿甲醚对血吸虫超微结构的影响

蒿甲醚是青蒿素的一个衍生物,不仅是有效的抗疟药,而且对血吸虫特别是血吸虫童虫亦有效,并已在20世纪末被发展为预防血吸虫病的药物.为了了解蒿甲醚的抗血吸虫作用,除观察其对血吸虫生化代谢的影响外,还用扫描电镜和透射电镜观察了蒿甲醚对感染人体的主要3种血吸虫,即日本血吸虫、曼氏血吸虫和埃及血吸虫超微结构的影响,结果表明蒿甲醚不仅损害血吸虫的皮层、感觉器和皮层结节,而且对虫的肌层、实质组织、肠上皮细胞和卵黄细胞等亦引起广泛的损害.该文综述了蒿甲醚对这3种血吸虫超微结构损害的观察结果,并进行了讨论.     

环孢素A体外抗曼氏血吸虫雄虫的时间生物学研究

目的：探讨环孢素Ａ体外抗曼氏血吸虫的作用。方法：ＭＦ１小鼠实验感染曼氏血吸虫６ｗｋ后，经主动脉和门静脉灌注收虫。将雄虫放入含有１μｇ／ｍｌ、１０μｇ／ｍｌ、１５μｇ／ｍｌ、２０μｇ／ｍｌ和２５μｇ／ｍｌ环孢素Ａ的１９９培养液中体外培养。用扫描电镜对药物所致的虫体皮层损害作时间生物学观察。结果：在体外，雄虫经１μｇ／ｍｌ环孢素Ａ作用后，体嵴的结构疏松；经１０μｇ／ｍｌ环孢素Ａ作用２４ｈ后，雄虫皮层肿胀；雄虫经１５μｇ／ｍｌ环孢素Ａ作用８ｈ－２４ｈ后，虫体皮层破溃；虫体经２０μｇ／ｍｌ药物作用２４ｈ后，雄虫皮层明显破溃；雄虫经２５μｇ／ｍｌ环孢素Ａ作用８ｈ后，皮层褶嵴受损；作用１６ｈ后，皮层肿胀；作用２４ｈ后，皮层极度破溃，皮棘脱落。药物所致的虫体皮层损害与剂量和时间呈依赖关系。结论：环孢素Ａ具有直接杀曼氏血吸虫的作用。     

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。     

Tegumental changes in 21-day-old Schistosoma mansoni harboured in mice treated with artemether

Alterations in the tegument of 21-day-old Schistosoma mansoni, caused by artemether administered to the infected mice, were studied using scanning electron microscopy (SEM). Mice were infected with S. mansoni cercariae, and after 21 days a single dose of artemether (400 mg/kg) was administered intragastrically. After 24, 72 h and 7 days groups of three mice were killed and the schistosomules collected by perfusion, fixed and processed routinely, and examined by SEM. After 24 h, all male and female worms examined showed alterations in the tegument, characterised by swelling, vesiculation and fusion of tegumental ridges; peeling, erosion and collapse of damaged tegumental surface, and also destruction of the oral sucker and acetabulum. After 72 h, severe damage to the tegument was seen, usually including extensive peeling, swelling and vesiculation, and host leukocytes were adhered to the damaged surface. Some worms were surrounded by clusters of host leukocytes or had even disintegrated. Seven days after treatment, some schistosomules still showed severe tegumental damage, but in some cases the damage was less than at earlier times, which suggested that those schistosomules that had survived were beginning to recover. The ability of artemether to cause severe damage to the tegument correlates with its high efficacy in killing 21-day-old schistosomules.     

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.     

Morphological tegument alterations of adult Schistosoma mansoni, harbored in non anti-helminthic treated, high-immune-tolerogenic and low-inflammatory mice

The present study exhibits original results of S. mansoni tegumental alterations due to contact with the immune system of non anti-helminthic treated mice. We compared, by SEM, the tegument of adult worms recovered from strains of mice genetically selected to extreme phenotypes of resistance (TR strain) and susceptibility (TS strain) to egg-albumin oral tolerance (OT). The parasites recovered from TR mice displayed no morphologic alteration, while specimens collected from TS mice presented tubercle swelling with blunted and shortened spines in lower density, increased sensory organelle numbers, fusion and tegumental ridge peeling. These tegument alterations were similar to those described for Artemether or Praziquantel treatment, supporting observations that the host immune system influences the development and function of the tegument of worms harbored in both anti-helminthic treated and non-treated mice. Our results are indicative that the development and function of the worm tegument depend on the immune regulatory capacity of each individual host.     

Histopathological changes in juvenile Schistosoma haematobium harboured in hamsters treated with artemether

Histopathological changes in juvenile Schistosoma haematobium, caused by artemether administered to the infected hamsters, were studied. Hamsters were infected with S. haematobium cercariae, and after 28 days, a single dose of artemether (300 mg/kg) was administered intragastrically. After 24 h, 72 h and 7 days, groups of two hamsters were sacrificed, and livers were removed, fixed and processed routinely, and examined by light microscopy. After 24 h, 93% of the schistosomulae examined showed degeneration, which included swelling of the tegument, adherence of inflammatory cells to the damaged tegument, collapsed and damaged intestine, and infiltration of inflammatory cells, predominantly lymphocytes. After 72 h, the intensity of damage increased, including severe swelling of the tegument, loss of definition in the internal structures, collapse of intestine accompanied by release of pigment particles to the parenchymal tissues, and emergence of dead schistosomulae. Seven days after treatment, the number of dead schistosomulae increased, and most of them developed to an early- or late stage of dead worm granuloma. Meanwhile, 12% of the schistosomulae showed a normal appearance, which suggested that those schistosomulae that had survived the treatment were recovered to normal. The results demonstrated that artemether effectively acts against the juvenile stages of S. haematobium and confirms earlier results with S. japonicum and S. mansoni.     

Antischistosomal action of atorvastatin alone and concurrently with medroxyprogesterone acetate on Schistosoma haematobium harboured in hamster: surface ultrastructure and parasitological study

Aiming to study the influence of long-term administration of lipid lowering agents (atorvastatin; AV), and to study the action of combined treatment with injectable contraceptive (medroxyprogesterone acetate; MPA) on tegumental ultrastrucutre and survival of Schistosoma worms, this study was established. AV (0.9 mg kg-1) was administered orally for 49 successive days to Schistosoma heamatobium-infected hamster starting from day 35 post-infection (pi). Another group of infected hamster was administrated MPA intramuscularly (0.1 ml kg-1) at days 7 and 35 pi followed by AV treatment regimen. Both treatment regimens significantly affected the surface ultrastructure of the male worms more pronouncedly than the female ones. Combined treatment was more severe in action compared to single one. The combined treatment was characterized by losing of spines and damaging of tubercles throughout the tegument, severe erosion and peeling and appearance of deep crakes in different parts of the tegument. Moreover, mild to sever destruction to the oral suckers of both female and male worms was noticed. On the other hand, both treatment regimens significantly reduced numbers of recovered S. haematobium worms and tissue egg load. Oogram pattern was affected only in case of combined treatment with high percentage of dead eggs. In conclusion, AV, if given continuously for long time, has a pronounced antischistosomal action especially when accompanied with contraceptive intake. These promising results may encourage further investigation with the intention of their possible application on treatment of schistosomiasis as a complement strategy to praziquantel chemotherapy.     

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.     

对硝基苯甲酰还原青蒿素对日本血吸虫童虫的作用

小鼠感染血吸虫尾蚴后第7d,1次灌服对硝基苯甲酰还原青蒿素300mg/kg。结果表明:给药后4h童虫皮层即有变化,8h已十分明显。主要表现为表皮水肿,皮层褶嵴融合,形成大量球状物或小泡。12h后皮层糜烂破溃剥落,并有白细胞附着于皮层损害处。从体表面积和体积的测量计算看,7～12d龄童虫生长基本停滞,而第13d又趋恢复。此结果为本药预防血吸虫病的最佳疗程的设计提供了科学依据。     

Tegumental changes in adult Schistosoma mansoni harboured in mice treated with praziquantel enantiomers

Praziquantel administered to the host causes damage to the tegument of Schistosoma mansoni. In this study, the effects of racemic praziquantel (Pra) and its enantiomers, levo-praziquantel (L-Pra) and dextro-praziquantel (D-Pra) were compared using scanning electron microscopy (SEM). Mice infected with S. mansoni for 49 days were treated with a single dose of Pra (300 mg/kg), L-Pra (150 mg/kg) or D-Pra (150 or 600 mg/kg). Groups of three mice were killed after 4 and 24 h, and schistosomes collected by perfusion and examined by SEM. Treatment with Pra or L-Pra, for 4 or 24 h, caused tegumental damage to S. mansoni including severe swelling, vacuolization, fusion of the tegumental ridges and loss or shortening of the spines on the tubercles, collapse and peeling. After treatment with D-Pra at 150 mg/kg, no apparent damage was observed. When the dosage was increased to 600 mg/kg, after 4 h lesions on the tegument similar to those induced by Pra or L-Pra were seen, but less severe. After 24 h, there was evidence of recovery. The study thus clearly showed that L-Pra was more active than D-Pra in causing tegumental damage. D-Pra showed a qualitatively similar activity at a higher concentration. It is possible that this effect was due at least to some extent to the small amount of L-Pra (<2%) which was present in the preparation of D-Pra used.