紫外线致弱日本血吸虫尾蚴感染小鼠引起的肺组织细胞反应及虫体扫描电镜观察

目的通过观察日本血吸虫(Schistosoma japonicum,Sj)紫外线辐照致弱尾蚴感染小鼠后肺组织的细胞反应以及肺期虫体的受损情况,探寻致弱尾蚴在小鼠体内诱导免疫效应机制和Sj受损情况。方法以紫外线致弱Sj尾蚴经腹部皮肤感染小鼠4d、7d、14d和45d后剖杀,分别取肺组织,固定、切片,光镜下观察虫体周围的组织细胞反应,并与同时期的感染小鼠组织切片进行比较,同时,对小鼠体内肺期Sj童虫进行扫描电镜观察。结果感染后4~7d,小鼠肺期童虫虫体周围出现较明显的出血灶和炎症反应,并有一定量的嗜酸性粒细胞、中性粒细胞、巨噬细胞等炎症细胞的浸润,同时期的正常感染小鼠组织内虫体周围炎症反应却不明显;虫体体壁可见不同程度的损伤,电镜观察显示小鼠体内的肺期童虫存在明显的畸形和发育延迟。结论紫外线辐照致弱尾蚴感染后Sj在小鼠体内不能正常发育成熟,和正常尾蚴相比,致弱尾蚴在肺期滞留时间较长,仅有极少数虫体可移行至肠系膜或肝脏,但宜不能发育成熟,引起的病理损害主要表现为在肺期弥漫性出血灶、炎症细胞浸润等反应,这些特征可能与血吸虫致弱尾蚴感染免疫机制有关。     

斯氏并殖吸虫感染犬肝、肺组织中JAK-STAT和NF-Κβ的表达

目的探讨JAK-STAT、NF-Κβ在斯氏并殖吸虫感染犬肺、肝组织表达和意义。方法自流行区采集溪蟹,分离斯氏并殖吸虫囊蚴,经腹腔注射感染犬,3月后剖杀,取肝、肺组织,固定、切片,HE染色后光镜下观察虫体周围的组织细胞反应,免疫组织化学方法观察JAK-STAT和NF-Κβ的表达水平。结果肝、肺组织中虫体周围出现较明显的坏死区、出血灶和炎症反应,有嗜酸性粒细胞、中性粒细胞、巨噬细胞等炎症细胞的浸润;肝、肺组织中JAK-STAT、NF-Κβ呈阳性表达,比正常组织表达高（P〈0.05）。结论斯氏并殖吸虫在肝、肺组织中的机械破坏作用和炎症病理反应激活了JAK-STAT、NF-Κβ信号的表达。     

日本血吸虫在大鼠体内的发育及其引起的病理变化

目的　观察日本血吸虫 (Schistosomajaponicum ,Sj)在大鼠体内的发育及其引起的病理变化。方法　以小鼠为对照 ,光镜下比较感染后第 4d、7d、14d大鼠与小鼠体内童虫的形态学及第 4 5d虫卵肉芽肿反应 ,用电镜观察两种鼠系肺内 4d龄童虫的体表特征。结果　感染后 4～ 7d ,大鼠肺期童虫周围出现严重的炎症反应 ,虫体体壁可见不同程度的损伤 ;感染后第14d ,大鼠体内童虫的形态及大小与小鼠体内的童虫相似 ,炎症反应减轻。感染后第 4 5d大鼠体内的雌虫比雄虫小 ,但雌雄虫均显著小于相应小鼠体内的成虫 (P <0 0 0 1)。经测定 ,大鼠肝内单个虫卵引起的肉芽肿平均直径明显小于小鼠肝内的相应病变 (P <0 0 1)。结论　Sj在大鼠体内发育差 ,引起的病理损害较小 ,这些特征可能与大鼠先天抗血吸虫感染免疫有关。     

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。     

小鼠感染日本血吸虫后肝脏内的细胞反应

本文报告C57BL/6小鼠感染日本血吸虫后,随着血吸虫及虫卵的发育,肝脏内产生相应的细胞反应。感染后第七天,肝窦及小叶间静脉周围嗜酸性粒细胞和淋巴细胞开始增加,在28天小叶间静脉周围开始出现浆细胞。提示宿主对童虫-成虫的反应是免疫反应。虫卵发育成熟后,肝窦内嗜酸性粒细胞再次升高,小叶间静脉周围各类细胞继续上升,提示宿主对童虫-成虫的反应与对虫卵的反应是分阶段的。本研究还发现,虫卵一旦发育成熟,肉芽肿迅速形成,推测虫卵成熟前宿主已处于致敏状态,宿主对童虫-成虫的免疫反应可能参与虫卵肉芽肿的形成。     

紫外线减毒日本血吸虫尾蚴免疫小鼠的皮肤组织细胞反应

目的 :探讨紫外线减毒血吸虫尾蚴免疫宿主的皮肤组织在抗攻击感染中的作用。方法 :88只小鼠分为 4组 ,1、2组分别以 50± 3条紫外线减毒日本血吸虫尾蚴免疫或日本血吸虫尾蚴感染 ,5wk后以 10 0 0± 10 0条尾蚴进行攻击感染 ;3、4组分别以减毒尾蚴或尾蚴 10 0 0± 10 0条免疫或初次感染。各组均于感染或接种后 6- 12 0 h定时取局部皮肤组织作病理观察。结果 :( 1)免疫攻击组皮肤组织内炎症细胞杀伤童虫现象最明显、炎症反应最强且持续时间最长 ,嗜酸性粒细胞( EOS)浸润百分数最高 ;( 2 )感染攻击组呈现相似炎症反应但程度略轻 ;( 3)免疫对照组减毒童虫在皮肤内滞留时间延长 ,至 12 0 h皮下仍可见较多童虫 ;( 4 )感染对照组皮肤内的童虫数于 72 h后明显减少 ,童虫周围轻微炎症反应。电镜观察可见免疫攻击组童虫内部结构破坏 ,虫体周围 EOS、淋巴细胞增多 ,肥大细胞颗粒溶解。结论 :提示皮肤组织的细胞免疫反应在血吸虫减毒尾蚴免疫的宿主抗攻击感染保护性免疫中起重要作用。     

广州管圆线虫感染小鼠后在其体内分布及小鼠组织病理学实验观察

为观察广州管圆线虫感染小鼠后在小鼠体内的分布及对小鼠的致病作用 ,以广州管圆线虫第三期幼虫人工感染实验小鼠 ,分批处死后 ,镜检并记录各部位虫体 ,同时进行组织病理学观察。结果感染不同时间后 ,小鼠肝、心、肺、脑、脊髓、肾、眼球、肌肉等部位均发现有幼虫寄生 ,其中脑、脊髓是广州管圆线虫的主要寄生部位。虫体寄生部位因虫体的机械作用和炎症反应而受损。同时还对广州管圆线虫幼虫在小鼠体内的移行和发育作了初步探讨     

广州管圆线虫成虫可溶性抗原诱导小鼠保护性免疫的研究

目的 探讨广州管圆线虫成虫可溶性抗原诱导小鼠的保护性免疫,为广州管圆线虫病的免疫预防研究提供科学依据。方法 以广州管圆线虫成虫可溶性抗原隔周腹腔注射免疫小鼠1次,共3次,末次免疫1w后,用300条广州管圆线虫第三期幼虫感染每鼠,攻击感染4w后解剖每鼠检获虫体,计算减虫率,并观察、测量检获虫体形态、大小。此外,还检测了小鼠体内血清特异性抗体IgG和血液嗜酸性粒细胞含量。结果 免疫组小鼠与对照组比较,有极显著的减虫效果（P＜0．01）,800μg、400μg和200μg免疫原组小鼠的减虫率分别是44．0％、42．6％和18．7％。免疫组小鼠体内检获的虫体比对照组要少。免疫组小鼠血清抗体水平及血液嗜酸性粒细胞绝对值均高于对照组（P＜0．01）。结论 广州管圆线虫成虫可溶性抗原可诱导小鼠产生保护性免疫。     

白细胞介素-5转基因小鼠的高嗜酸性粒细胞血症不能阻止旋毛虫的感染

嗜酸性粒细胞增多是宿主感染蠕虫后的典型特征之一。白细胞介素-5(IL-5)又是导致嗜酸性粒细胞分化的主要因素。体外培养试验证明,嗜酸性粒细胞是蠕虫感染的效应细胞,但体内试验对其抗蠕虫的效应还不清楚。本研究以IL-5转基因小鼠为研究对象,将非转基因C3H/HeN小鼠作为对照,比较两者感染旋毛虫幼虫后肠内的成虫数、雌虫的生殖力和骨骼肌中的幼虫数。     

异盘并殖吸虫在大鼠体内发育的实验研究

目的：探讨异盘并殖吸虫在大鼠体内发育的多态性及其主要寄生部位，确定大鼠的宿主性质。方法：囊蚴经口感染大鼠后，用生理盐水逸出法，分离组织中童虫或直接从肺和肝脏虫囊内取虫，测量虫体大小，染色并摄影。结果：异盘并殖吸虫感染大鼠１４ｄ时，虫体侵入肝脏、肌肉和腹腔；３０ｄ时，发育出现分化。体腔中虫体发育迅速，成为具有生殖器官雏形的大型童虫，肌肉中虫体发育迟缓；感染７０ｄ以后，大鼠的肺、肝和胸壁有虫囊形成，囊内虫体发育成熟且产卵。９只大鼠感染７０ｄ后，其中７只在肝脏检获多个虫囊，最多达１１个虫囊。囊内虫体发育良好，成熟率为７８．６％－１００％，最大虫体为１６ｍｍ×８ｍｍ。肝脏严重受损，表面凹凸不平，纤维结缔组织增生，肝细胞变性坏死。分布于肌肉中的虫体占３２．６％－８２．４％，始终保持小型童虫状态。感染后１５６ｄ，虫体仍无发育，其大小为９１４．８７μｍ±７８．２１μｍ×５２５．３４μｍ±７６．２６μｍ，排泄囊内充满黑色颗粒。结论：异盘并殖吸虫在大鼠体内发育呈多态性且多部位寄生，大鼠为其终宿主及其转续宿主。     

Antigenicity and immunogenicity of the tegumental outer membrane of adult Schistosoma mansoni

The tegumental membranes of adult Schistosoma mansoni have been isolated and purified and shown to function as potent immunogens; they elicit an essentially identical immune response in rabbits, rats and mice. Anti-membrane antisera harvested from these animals consistently recognized common antigens, of relative molecular weight (mol. wt) 32 000 and 20 000, on the surface of young schistosomula, 5 day old lung worms and adult worm purified membranes. An additional molecule of 25 000 mol. wt was present on the surface of lung worms and adult worm membranes and was specifically recognised by serum from chronically infected mice and by serum from rabbits inoculated with adult worm purified membranes. The concept of antigenic identity between developmental stages that parasitize the mammalian host was further substantiated by the observation that anti-membrane antiserum bound to live schistosomula, lung worms and adult parasites as measured by indirect immunofluorescence. In complement-mediated in vitro cytotoxicity assays, the sera from rabbits inoculated with either adult worm purified membranes, or the 32 000 mol. wt antigen partially purified from adult worm membranes, mediated levels of schistosomula killing as high as those obtained with sera from chronically infected mice. These rabbit antisera also promoted eosinophil adherence and killing of newly transformed schistosomula, but lung stage parasites, despite binding the anti-membrane antiserum, were refractory to both humoral and cellular cytotoxicity. The significance of antigenic identity is discussed in relation to the concept of concomitant immunity.     

东方田鼠IgG3抗体抗血吸虫病作用研究

采用ELISA方法, 平行检测东方田鼠、 BALB/c小鼠和昆明小鼠在攻击感染前、 后的血清抗血吸虫童虫(SSA)、 成虫 (SAWA) 和虫卵(SEA) IgG3抗体水平, 并进行体内、 外试验, 观察IgG3抗体抗血吸虫效应。结果攻击感染后第4周, 东方田鼠抗SSA和SAWA的IgG3抗体水平增幅较大, 分别较感染前增加79.6%和49.6%, BALB/c小鼠IgG3抗体在攻击感染后无明显增加。野生和室内繁殖的东方田鼠的IgG3抗体所致童虫死亡率分别为昆明小鼠的5.88和2.35倍, 前者还诱生出较高的减虫率 (39.8%)。提示东方田鼠IgG3抗体可能是其抗血吸虫感染的主要免疫物质。     

Effects of protective immune serum on the yields of parasites and pulmonary cell reactions in schistosome-infected rats

Yields of parasites during the period of worm migration from the lungs to the portal circulation were measured in S. mansoni-infected Fischer rats passively immunized with protective serum from twice-infected donor rats. Two effects of protective serum were observed in recipient rats relative to normal serum recipients: yields of schistosomula from lungs were higher and yields of (immature) worms from the portal circulation were lower throughout the period analyzed. Histopathological analysis of lung tissue confirmed the presence of greater numbers of schistosomula in lungs of passively immunized rats. In addition, the percent of lung schistosomula involved in all categories of inflammatory reactions was greater in recipients of protective rat serum. The kinetics of accumulation of worms perfused from the portal circulation of normal and passively immunized rats indicate that in the latter group a smaller fraction of worms successfully migrates to the portal circulation. These findings support the hypothesis that protective activity of the serum prevents a portion of worms from successfully completing migration from the lung to the portal circulation.     

青蒿琥酯抗日本血吸虫童虫和成虫作用的研究

目的 观察青蒿琥酯对不同阶段日本血吸虫的损害作用,揭示青蒿琥酯的杀虫机制.方法小鼠感染尾蚴18 d时给予青蒿琥酯300 mg/kg,24 h后灌注法收集童虫,并用紫外吸收法和Bradford标准曲线法测定青蒿琥酯对日本血吸虫18 d童虫DNA和蛋白质含量的影响;分别将10条虫体在含有3H胸腺嘧啶核苷的培养基中培养24 h后,用滤膜法和匀浆法测定青蒿琥酯对标记核苷掺入童虫DNA的影响;感染血吸虫尾蚴21 d的小鼠一次性灌服青蒿琥酯300 mg/kg,给药后21 d,灌注法收集成虫,观察青蒿琥酯对日本血吸虫成虫生殖器官大小及生殖细胞发育的影响;小鼠感染血吸虫33 d时给予同样的青蒿琥酯进行治疗,24 h和48 h后处死小鼠,将肝脏制作组织切片,在光镜下观察同等剂量青蒿琥酯引起的成虫肝移和形态学变化的影响.结果 青蒿琥酯体内作用18 d的虫体,24 h后,童虫的DNA和蛋白质含量均较对照组明显减少,减少率分别为23.0%和33.6%(P＜0.01);在含有3H胸腺嘧啶核苷的培养基中培养24 h后,童虫摄入标记的核苷及核苷掺入童虫DNA的量较对照组也明显减少,减少率分别为61.1%和40.8%(P＜0.01);21 d给药组小鼠体内雌虫卵巢的成熟、发育受到了抑制;药物作用于虫体33 d后能明显引起虫体形态的变化,特别是虫体体表.结论 青蒿琥酯能减少日本血吸虫童虫蛋白质和DNA的含量,能明显抑制虫体对标记核苷的摄入以及标记核苷掺入虫体DNA的量,能引起虫体体表明显的组织形态学变化,并且能抑制雌虫卵巢的发育,降低或抑制雌虫的产卵,能有效减轻血吸虫病的病情和控制传播.     

Comparison of Schistosoma mansoni migration patterns in normal and irradiated cercaria-immunized mice by means of autoradiographic analysis. Evidence that worm elimination occurs after the skin phase in immunized mice

Migration and elimination of radiolabeled Schistosoma mansoni were compared in naive and irradiated cercaria-immunized mice by autoradiography of compressed host tissues. The results indicated that 1) most of the normal elimination of schistosomula in unimmunized mice and the additional elimination in immunized mice occur at some point(s) after arrival of schistosomula in the lungs and before their development into adult worms, 2) migration of schistosomula from skin to lungs is delayed for several days but not reduced in immunized mice, 3) migration of schistosomula from lungs to liver is delayed for several days in immunized mice, and 4) schistosomula reach the liver in reduced numbers or are killed and cleared in the liver in greater numbers in immunized mice. The lung chop procedure was shown to recover schistosomula from control and irradiated cercaria-immunized mice with equal efficiency. Autoradiography of all tissues of the body demonstrated that, in both control and immunized mice, at least 20-25% of the schistosomula detectable 2 and 3 weeks after infection were present in tissues other than the skin, lungs and liver.     

Site requirements and kinetics of immune-dependent elimination of intravascularly administered lung stage schistosomula in mice immunized with highly irradiated cercariae of Schistosoma mansoni

Experiments were performed to compare the migration and survival of 75Se-labeled schistosomes, introduced by percutaneous cercarial exposure or by intravascular administration of 7-day-old lung stage schistosomula, in control and irradiated cercaria-immunized mice. Schistosomula were intravascularly introduced into the lungs, systemic organs and liver by injection via the femoral vein (FV), left ventricle (LV), and superior mesenteric vein (SMV), respectively. The fate of challenge larvae was examined by autoradiography of host tissues and by recovery of adult worms. It was found that both normal and immune elimination were site-dependent. In control mice 45%-60% of cercarial penetrants and lung schistosomula injected into the FV and LV were recoverable as adult worms, while a significantly greater number (70%-85%) were recoverable when lung schistosomula were injected into the SMV. In immunized mice, parasites introduced as either cercariae or FV-injected schistosomula were both highly sensitive to immune elimination. LV-injected schistosomula were also sensitive but to a slightly lesser degree. In contrast, schistosomula placed directly in the liver by SMV injection were totally insensitive to immune elimination. It was concluded that elimination of schistosomula in irradiated cercaria-immunized mice occurs in the lungs and/or in the systemic organs, but not in the liver. Also, it was concluded that immune elimination is not a rapid process, since more than 7 days were required after intravascular challenge for the development of demonstrable differences between control and immunized mice.     

Schistosoma mansoni: age-dependent susceptibility to immune elimination of schistosomula artificially introduced into preinfected mice

Mice chronically infected with Schistosoma mansoni exhibited a significant resistance to a second infection with the same parasite, as demonstrated by their challenge worm burdens measured by portal perfusion. A decreased worm recovery was also exhibited by chronically infected mice when the challenge was administered intravenously using 3-h schistosomula obtained by the isolated skin technique or using 5-, 6-, 7- and 9-day-old schistosomula obtained from the lungs ofinfected donor mice. Variable results were obtained with 10- and II-day-old forms, while schistosomula which were 12days old or older, did not undergo significant rejection when introduced into the mesenteric veins of preinfected mice. Attempts to analyse these phenomena using the‘lung assay’were made complicated by the observation that the day of maximum recovery from the lungs was dependent upon the age of injected worms.     

Immunization with newly transformed Schistosoma mansoni schistosomula tegument elicits tegument damage, reduction in egg and parasite burden

The surface of the schistosomula is an important target for host immune system attack because the tegument represents the interface between host and parasite and thus is a potential candidate for the development of new intervention strategies. In this study, we evaluated the ability of schistosomula tegument (Smteg) to induce protection in mice. Immunization of mice with Smteg together with Freund adjuvant induced a Th1 type of immune response associated with a significant reduction in worm burden (43-48%), eggs trapped in the liver (65%), eggs eliminated in the faeces (59-60%) and granuloma number (41%). Lastly, during an in vitro study, worms from mice immunized with Smteg showed damage in the adult worm tegument and impaired egg laying.     

Autoradiographic analysis of resistance to reinfection with Schistosoma mansoni in mice. Evidence that the liver is a major site of worm elimination

Migration and elimination of 75Se-labeled Schistosoma mansoni were studied in previously infected mice by means of autoradiography and worm recovery. As in control mice, there appeared to be little if any worm elimination in the skin of previously infected mice. In previously infected mice, there appeared to be some worm elimination in the lungs and in migration sites between the lungs and liver, though much less than would have been expected from previous studies. In two of three experiments most of the challenge worm elimination in previously infected mice, above the normal attrition level occurring in the controls, appeared to take place in the liver. In the third experiment, it appeared that all of the challenge worm elimination occurred after migration to the lungs, and at least one-third of it in the liver. It was also observed that the lung chop procedure recovered viable schistosomula much less efficiently from previously infected mice than from controls indicating that the reduction in lung schistosomulum recovery overestimates the amount of lung and prelung killing that occurs in reinfected mice.