细胞毒作用前后马来丝虫微丝蚴氨基酸组成及含量的测定分析

目的通过观察马来丝虫微丝蚴(mf)经细胞毒作用后,虫体氨基酸含量的变化,进一步探讨宿主体内的杀虫机制.方法应用高速氨基酸分析仪对细胞毒作用前后的周期型马来丝虫mf进行氨基酸组成及含量的分析比较.结果马来丝虫mf含1 7种氨基酸,缺少色氨酸.经宿主细胞毒作用后的虫体氨基酸绝对含量明显低于细胞毒作用前(P＜0.05).其中,精氨酸、脯氨酸、甲硫氨酸、赖氨酸下降显著(P＜0.01).结论虫体氨基酸含量下降,尤其是碱性氨基酸与酸性氨基酸、芳香族氨基酸之间比率下降可能是宿主体内杀伤丝虫mf的机制之一.     

细胞毒作用前后马来丝虫微丝蚴氨基酸组成及含量的测定分析

目的 通过观察马来丝虫微丝蚴（mf)经细胞毒作用后，虫体氨基酸含量的变化，进一步探讨宿主体内的杀虫机制。方法 应用高速氨基酸分析仪对细胞毒作用前后的周期型马来丝虫mf进行氨基酸组成及含量的分析比较。结果 马来丝虫mf含17种氨基酸，缺少色氨酸。经宿主细胞毒作用后的虫体氨基酸绝对含量明显低于细胞毒作用前（P＜0．05）。其中，精氨酸、脯氨酸、甲硫氨酸、赖氨酸下降显著（P＜0．01）。结论 虫体氨基酸含量下降，尤其是碱性氨基酸与酸性氨基酸、芳香族氨基酸之间比率下降可能是宿主体内杀伤丝虫mf的机制之一。     

细胞毒作用对周期型马来丝虫微丝蚴化学元素含量的影响

目的　通过观察细胞毒作用对周期型马来丝虫微丝蚴 (mf)化学元素含量的影响 ,进一步探讨宿主体内杀伤虫体的机制。方法　应用原子吸收光谱分析法对细胞毒作用前后的周期型马来丝虫mf7种微量元素和 2种常量元素的含量进行检测分析。结果　所测的周期型马来丝虫mf7种微量元素中铁 (Fe)含量最高 ;镉 (Cd)含量最低。常量元素钙 (Ca)高于镁(Mg)。经细胞毒作用后虫体各微量元素和常量元素含量均有所下降 ,尤其是微量元素中的铁 (Fe)、铜 (Cu)、锰 (Mn)、铬 (Cr)、镉 (Cd)铝 (Al)和常量元素中的镁 (Mg)下降显著 (P <0 0 1 )。结论　经细胞毒作用后虫体内的微量元素和常量元素大量丢失 ,造成其营养代谢和生理功能的障碍 ,可能是宿主体内杀伤丝虫mf,导致虫体死亡的因素之一     

一种克隆化马来丝虫抗原在微丝蚴血症小鼠模型中的保护性效应

作者曾报道由马来丝虫表达文库筛选出一株1800bp的cDNA克隆,此克隆编码的548个氨基酸蛋白相当于马来丝虫微丝蚴(mf)的62kDa抗原,与保护性mf抗原有关。本文报告了该重组蛋白在微丝蚴血症小鼠模型中的保护性效应、免疫原性和虫期特异性。     

丝虫病研究Ⅴ.彭亨丝虫和马来丝虫微丝蚴在埃及伊蚊、东乡伊蚊、尖音库蚊骚扰亚种及骚扰阿蚊体内的脱鞘

长期以来,有人认为班氏丝虫、马来丝虫、彭亨丝虫及罗阿丝虫的微丝蚴(mf)被蚊摄入后,立即在胃内脱鞘。也有人报告:彭亨丝虫mf被四斑按蚊摄入后,立即在血块中脱鞘。Yamamoto等(1983)报道,彭亨丝虫在骚扰阿蚊的胃及腹部血腔内脱鞘。从而认为,鞘可能起着保护幼虫的作用。为了了解mf脱鞘是否常在蚊血腔中进行,作者采用感染丝虫的长爪沙鼠作蚊血源进行实验。感染彭亨丝虫的鼠血mf平均密度为73.5条/cmm和2.6条/cmm;感染马来丝虫的为1.5条/cmm,均以40mg/kg戊     

伊维菌素和海群生治疗后改变人体对丝虫特异性抗原的免疫应答

外周血液中微丝蚴(mf)的出现与体内抗丝虫的体液和细胞免疫应答的减弱有关,海群生(DEC)治疗可导致对丝虫特异性抗原反应显著增高。已知DEC杀微丝蚴作用需宿主因素参与,且有杀丝虫成虫作用。伊维菌素不同于DEC,现在认为,它直接杀mf,对成虫无作用。为此,比较上述2种药物治疗后血内微丝蚴减少与免疫反应变化之间的关系,可有助于阐明治疗效果的免疫学依据。     

马来布鲁线虫:伊维菌素抑制微丝蚴脱鞘

鉴于经伊维菌素(Ⅳ)治疗后,盘尾丝虫或班氏丝虫病人的皮肤及血内微丝蚴(mf)数量显著下降,因而蚋或伊蚊媒介的mf摄入量也相应减少,以及Ⅳ可阻断埃及伊蚊经沙鼠传播布鲁线虫的事实,作者进一步研究Ⅳ对mf脱鞘过程的作用方式,同时研究体外Ⅳ抑制mf脱鞘的效果以及对阻断丝虫病传播的潜在意义,进行了如下实验。方法:给实验感染马来丝虫的mf阳性长爪沙鼠腹膜下注射Ⅳ,剂量为200μg/kg,     

一个新的班氏丝虫病实验性传播效能指数

丝虫病实验性传播指数最初由Kart-man(1954)提出,其后经Wharton(1957,1960)改进,称Wharton指数,其定义是当1μl人宿主血中的微丝蚴(mf)数为1时,每只蚊虫体内的感染期幼丝虫数。该指数在过去的30年间被丝虫病研究人员广泛采用。但Kartman或Wharton指数所依据的是预期被吸血蚊吸入的mf理论数,而不考虑在吸血期间及其后可能影响mf数量的各种因素。为弥补这一缺点,进行了人宿主指端血,     

五种丝虫的氨基酸与化学元素

用高效液相（ＨＰＬＣ）研究人、牛、马、驴、骡与犬体内５种丝虫１８种氨基酸，人、畜丝虫分别含有１６和１７种，缺色氨酸。家畜丝虫氨基酸含量（μｇ／ｍｇ干粉）高于马来丝虫，其酸性和碱性氨基酸（Ｐ＜０．０５）及支链族和芳香族氨基酸（Ｐ＜０．０１）含量高低差异明显并非常显著。以原子吸收分光光度计测定丝虫含Ｚｎ，Ｃｕ，Ｆｅ，Ｍｎ，Ｃｄ５种微量元素中以Ｚｎ为高（μｇ／０．１ｇ干粉），２种常量元素中Ｃａ多于Ｍｇ，这将为研究丝虫（病）的生理代谢与免疫学诊断提供参考资料。     

用抗牛丝虫抗体Dot—ELISA检测人体丝虫循环抗原的研究

应用抗牛丝虫抗体及抗马来丝虫抗体进行Dot-ELISA检测49例班氏丝虫微丝蚴(mf)阳性血清,CAg阳性率分别为89.7％及91.8％;36例班氏丝虫mf(—)血清,CAg阳性率分别为47.2％及50.0％;31例马来丝虫mf(+)血清,CAg阳性率分别为87.0％及93.5％,非流行区肠线虫感染44例及正常人血清40例全部阴性,华支睾吸虫感染血清70例,两种抗体检测CAg的假阳性率分别为8.5％及7.1％,囊虫病血清76例,假阳性率均为3.9％。     

我国周期型马来丝虫六个省区虫株氨基酸的比较分析

目的　本实验进行丝虫种内分类学研究探讨我国六个省七个不同地区马来丝虫是否存在种内的生物学特性差异。方法　采用ＨＰＬＣ对贵州独山株、贵州荔波株、四川乐山株、湖北谷城株、安徽泾县株、浙江安吉株、福建建阳株马来丝虫成虫的１８种虫体氨基酸含量及种类进行分析比较。结果　七个地区马来丝虫虫体氨基酸的总含量经统计分析无明显的差异（Ｐ＞ ０．０５）,碱性氨基酸、酸性氨基酸以及芳香族氨基酸亦无明显的差异（Ｐ＞ ０．０５）,但在一些种类的氨基酸含量高低和个别氨基酸的缺如有一定的差异。结论　七个虫株丝虫虽有微小的生物学差异,但目前尚未发现有明显的种内分化的迹象     

Platelet mediated killing of larvae from different filarial species in the presence of Dipetalonema viteae stimulated IgE antibodies

The platelets from normal rats interact with microfilariae of Dipetalonema viteae in vitro in the presence of antibodies leading to the killing of the parasite. The antibody involved in this reaction is identified as IgE because the absorption of immune rat serum on anti-rat IgE column or the pretreatment of platelets with anti-Fc epsilon receptor resulted in a significant reduction in the percentage of killing of microfilariae. This antibody, which mediates platelet activity towards microfilariae, appears early in the secondary infection and persists for a short period of time. This short-lasting IgE antibody is not apparently present in the form of large complexes since the supernatant but not the pellet after ultracentrifugation was able to mediate killing of microfilariae by platelets. IgE-dependent platelet-mediated parasite killing is neither stage- nor species-specific because the microfilariae (LI) of Brugia malayi or of Loa loa and infective larvae (L3) of D. viteae or of B. malayi were killed when they were incubated with the serum obtained from rats at day 8 after secondary infection with adult D. viteae worms. The results of the present study suggest that platelets can actively participate in the immunological killing of filarial larvae.     

Release of prostaglandin E2 by microfilariae of Wuchereria bancrofti and Brugia malayi.

To elucidate the local release of immunomodulatory prostaglandins by intravascular filarial parasites, the formation of prostaglandin E2 (PGE2) was examined in individual microfilariae of Wuchereria bancrofti and Brugia malayi. Following incubation of living microfilariae immobilized in an agar matrix, prostaglandins released by the parasites were fixed by carbodiimide and localized by indirect immunofluorescence. Prostaglandin E2 was specifically detected around the entire surface of microfilariae with anti-PGE2 antiserum, but not with control nonimmune or PGE2 affinity-immunoadsorbed antiserum. These results provide direct evidence that individual microfilariae of W. bancrofti as well as B. malayi release prostaglandins into their microenvironment. The release of PGE2 by these intravascular parasites may modulate host leukocyte responses, and thereby contribute to the immune defects observed in infected humans with peripheral microfilaremia.     

抗体和(或)补体依赖细胞介导的对周期型马来丝虫微丝蚴细胞毒作用的体外研究

用碘六醇(Iohexol)分离液从大鼠腹腔渗出液中分离出效应细胞用于体外试验。结果表明,在特异性抗周期型马来丝虫微丝蚴(mf)血清存在时,中性粒细胞(Neu)和巨噬细胞(Mφ)对mf都有强烈的粘附和杀伤作用;嗜酸粒细胞(Eos)只表现粘附效应。正常鼠血清存在时,Neu、Mφ对脱鞘mf的粘附作用要高于Eos。血清加入EDTA可明显地抑制效应细胞的粘附和细胞毒作用,而加入EGTA则无类似现象,提示补体通过激活替代途径参与了该反应。用葡萄球菌A蛋白(SPA)或兔抗大鼠IgG免疫球蛋白处理抗血清后,粘附细胞的虫体数显著下降,表明细胞的粘附效应主要依赖于IgG抗体。通过相差显微镜和电镜观察,显示效应细胞粘附于虫体表面,并对其产生损伤作用。     

Localization and immunogenicity of tubulin in the filarial nematodes Brugia malayi and B. pahangi

Tubulin was identified in the filarial nematodes Brugia malayi and B. pahangi by several approaches. Initially, a monoclonal antibody (6D8) was selected for its unusual binding to B. malayi microfilariae in indirect immunofluorescence assays: 6D8 showed granular, heterogeneously dispersed fluorescence on fixed parasites but did not bind to unfixed microfilariae. The microfilarial sheath did not bind 6D8, although it did bind fluoresceinated wheatgerm agglutinin. By Western blotting against microfilarial sonicate, 6D8 reacted with a 50,000-55,000 mol. wt protein, and also bound to purified chicken brain beta-tubulin. Additionally, this monoclonal antibody reacted with a recombinant fusion protein expressed by a clone (Bpa-7) originally isolated from an adult B. pahangi cDNA expression library by its reaction with chronic human filariasis serum. This clone encodes a small 40 amino acid C-terminal segment corresponding to residues 409-449 of beta-tubulin, and shows complete amino acid sequence homology with vertebrate beta-tubulin from 409 to 430 but 55% divergence (six amino acid substitutions, four insertions and one deletion) from human and chicken beta-tubulin over positions 431-449 at the C terminus. Antibody to both parasite and vertebrate (chicken) tubulin was found in filarial infection sera, with higher levels of autoreactive antibody apparent in amicrofilaraemic individuals. Immunogold electron microscopy was then used to localize beta-tubulin in B. malayi microfilariae and adult worms. Tubulin was shown not to be exposed on the microfilarial sheath or in the cuticle of either stage, but was found to be abundant in the somatic tissues. In microfilariae, 6D8 bound myofibril structures under the hypodermal layer, and also bound within cell nuclei. In the adult stage, tubulin was associated with muscle blocks, as well as the intestinal brush border and the embryonic uterine microfilariae.     

感染马来丝虫微丝蚴的中华按蚊组织化学观察

中华按蚊碱性磷酸酶、酸性磷酸酶、非特异性酯酶、乙酰胆碱酯酶、糖原及蛋白质等组织化学观察结果表明，感染马来丝虫微丝蚴后蚊体内的碱性磷酸酶、酸性磷酸酶、糖原及蛋白质含量均比未感染蚊明显降低。非特异性酯酶活性亦有一定改变，而乙酰胆碱酯酶活性则几无改变。     

贵州两个不同地区周期型马来丝虫成虫氨基酸的组成研究

应用高效液相色谱对贵州省内的两个不同地区周期型马来丝虫（贵州独山株、贵州荔波株）成虫的１８种氨基酸进行了检测和分析。结果显示贵州独山株与荔波株马来丝虫均检出１７种氨基酸，两株丝虫有１６种相同氨基酸。两株氨基酸的总含量无明显差异（Ｐ＞０．０５）。但独山株有丝氨酸，缺酪氨酸，而荔波株含酪氨酸，缺丝氨酸。     

Characterization of immunosuppressive proteins of Brugia malayi microfilariae

Inhibition of Concanavalin A-induced lymphocyte proliferation was used to monitor the partial purification and characterization of suppressor molecules from microfilariae of Brugia malayi. Suppressor activity was present in high molecular weight fractions of microfilarial extracts (Mr greater than 50 kd on SDS-PAGE) and was protease-sensitive but resisted treatment with sodium periodate, indicating that it is associated with parasite proteins. Suppressor activity was released by microfilariae cultured in vitro and could be detected in peritoneal exudates of intraperitoneally-infected jirds and in lymph and sera from athymic C3H/HeN mice with patent B. malayi infections. These findings indicate that immune unresponsiveness during patent filarial infections may result from the in vivo release by microfilariae of high molecular weight proteins that suppress host immune responses.