日本血吸虫尾蚴不同途径感染家兔的实验观察

将血吸虫尾蚴经兔腹背部皮肤和眼睑结膜感染家兔，获虫率分别为59．60％、58．40％和55．20％。     

日本血吸虫尾蚴经口腔粘膜感染小鼠的可行性研究

在寄生虫学与寄生虫病的科学研究与教学活动中 ,经常使用家兔和小鼠作为血吸虫病的动物模型 ,过去通常用经腹壁皮肤或经腹腔注射尾蚴的方法感染动物。经查阅NationalLibraryofMedicine、中国期刊网CNKI数字图书馆及维普资讯镜像站中刊数据库检索系统 ,尚未见尾蚴经口腔粘膜感染动物方法的相关文献报道。本实验进行了经口腔粘膜感染的可行性研究。1　材料与方法1.1　日本血吸虫尾蚴　阳性钉螺由湖南省寄生虫病防治研究所提供 ,以 2～ 4只 /管分别放入指管内 ,管内注满冷开水 ,置于2 5℃有光照的温箱内孵育 4～ 8h ,待尾蚴逸出后备用。1.2…     

珊瑚姜霜防止日本血吸虫尾蚴感染的实验研究

目的 观察珊瑚姜霜阻止日本血吸虫尾蚴侵入皮肤的效果。方法 在小鼠裸腹上涂不同浓度珊瑚姜霜后，先在泥水中爬8h模拟下水作业，然后再经腹部感染日本血吸虫尾蚴，35d后剖杀，用灌注法加撕碎法查找成虫，计算减虫率。结果 5％珊瑚姜霜减虫率为91％，与对照组相比差异有显著性（P＜0．01）。结论 珊瑚姜是一种可预防血吸虫尾蚴感染的中草药。     

C—6膜检测江滩水体中日本血吸虫尾蚴的初步观察

尾蚴是感染血吸虫病最直接的环节,对水体中尾蚴的检测,是血吸虫病监测的一项重要内容。它可以预报易感场所,为及时采取相应措施控制人群感染提供信息。江滩尾蚴分布规律的调查,在江宁县尚未系统开展。因此,我们选择江宁县长江新济洲作为调查区,利用Ｃ－６膜粘蚴法［...     

日本血吸虫尾蚴经不同途径和方式感染的研究

目的探讨尾蚴经IMDM悬液皮下注射和肌肉注射感染动物建立动物模型的可行性.方法22只昆明小鼠随机分为3组:A组经IMDM悬液皮下注射感染尾蚴,B组经IMDM悬液肌肉注射感染尾蚴,C组经典玻片贴皮感染尾蚴.45 d后剖杀检查成虫数目,并用间接ELISA法测定小鼠感染后第15、45天体内的抗血吸虫IgG抗体水平.结果45 d杀鼠后,A组成虫回收率为39.2%(P＜0.05),B组为32.3%(P＜0.05),C组为72.8%.感染后第45天A、B两组与C组小鼠体内IgG水平差异无显著性(P＞0.05).结论尾蚴经皮下、肌肉注射感染小鼠成功,其感染率均为100%.但与经典玻片贴皮感染动物在回收率方面仍有一定差距.     

防蚴润肤霜防御日本血吸虫尾蚴感染的研究

目的：实验评价新型少肤防护剂一防蚴润夫霜防御日本血吸虫尾蚴感染的效果，并了解其对皮肤的急性刺激反应。方法：采用模拟现场试验方法，分别在小白鼠腹部和尾部涂布防蚴润肤霜，并经泥水浸泡洗刷4-8h后接种日本血吸虫尾蚴，饲养40d解剖小鼠观察感染情况。以小鼠感染率、平均虫荷数和减虫率为评价指标，同时进行皮肤急性刺激试验。结果：防蚴润肤霜涂布小鼠腹部、尾部后减虫率达100％；家兔皮肤急性刺激试验结果为阴性。结论：防蚴润肤霜涂布皮肤后4-8h具有完全防御日本血吸虫尾蚴感染的作用，对皮肤无刺激作用。     

日本血吸虫尾蚴经口腔黏膜感染小鼠的研究

在寄生虫与寄生虫病的科学研究与教学活动中,经常使用家兔和小白鼠做日本血吸虫病的动物模型,过去通常用直接经腹壁皮肤或经腹腔注射尾蚴的方法感染动物,但用尾蚴经口腔黏膜感染动物模型的方法未见文献报道,笔者经过数年的摸索,进行了经口腔黏膜感染的观察研究。     

不同宿主感染日本血吸虫尾蚴的皮肤组织反应

本文观察了小鼠,大鼠、仓鼠、沙鼠、豚鼠、家兔、恒河猴和鸽8种动物于初次感染日本血吸虫尾蚴后不同时间皮肤的组织反应。结果表明其皮肤反应的情况反映了不同宿主对日本血吸虫易感性的特点。一般说来,初次感染的哺乳动物宿主皮肤的反应较为轻微,而非易感动物鸽的皮肤反应则非常剧烈.文中对无免疫抗力宿主、具有天然免疫抗力宿主及人工获得免疫抗力宿主的皮肤反应特点进行了比较和讨论。     

致弱尾蚴感染血清对日本血吸虫尾蚴和成虫抗原免疫识别初步研究

<正> 众所周知,血吸虫减毒尾蚴可诱导宿主产生较高免疫保护力,但是,刺激宿主免疫系统的究竟是哪些目标抗原,目前仍未定论。血清被动转移实验证明减毒尾坳多次免疫后血清可诱导宿主产生针对幼虫期的免疫保护,因此我们用多次免疫兔血清初步筛选日本血吸虫可溶性尾蚴中的保护性抗原,以期为血吸虫疫苗的研制提供一些新的线索。     

日本血吸虫尾蚴体表扫描电镜观察

目的观察日本血吸虫尾蚴体表结构.方法阳性钉螺逸出的尾蚴固定在4%戊二醛溶液中1～3 d.固定的标本按扫描电镜（SEM）要求,清洗、固定、脱水、干燥、镀金,用SX-40型SEM进行观察.结果尾蚴小棘几乎布满全身.尾体顶端的头器有两排隆起的围褶,中央为钻腺开口.围褶外围有无鞘的单纤毛乳突.腹吸盘位于体部的后1/3处,有尖刀状棘.尾干小棘比体部小棘长、少且不均匀.尾叉的棘较少,分布不均匀.尾叉的末端各有一个长约3.6 μm、直径3.2 μm的圆柱状尾突,中央均可见一个近似圆形、孔径约0.8 μm的排泄孔.结论观察到了小棘几乎布满全身的日本血吸虫尾蚴体表结构.观察并测量了尾叉末端尾突排泄孔.     

A field-evolved differential filtration method for recovery of schistosome cercariae

Modifications to Theron 's (1979) differential filtration technique are described which improve both sensitivity and reliability. Following pre-filtration to remove larger debris and some plankton, the sample is formalized; constant stirring prevents losses due to the cercarial stickiness normally caused by the fixation process. Once fixed, Schistosoma mansoni cercariae are reliably retained and well displayed on nylon monofilament cloth of 50 micrometers pore size. Such a coarse recovery filter permits very large samples to be processed and results in filters which are easy to read. Field comparison showed the method improved sensitivity by a factor of more than 20 times and laboratory evaluation indicated a recovery rate of over 80%.     

氯硝柳胺展膜油剂杀血吸虫尾蚴效果

取100 ml 30℃去氯水加入直径15 cm的平皿中,然后加入1%氯硝柳胺展膜油剂5μl,再用接种环挑取一环人工逸出的尾蚴于平皿中央,立即在解剖镜下观察尾蚴全部死亡所需要时间,并对加入1%氯硝柳胺展膜油剂放置0、24、48 h后的杀蚴效果进行观察。同时用去氯水作对照。放置3个不同时间段的1%氯硝柳胺展膜油剂均能在3 min内将尾蚴全部杀死,灭蚴效果差异无统计学意义(F=0.062,P>0.05),对照组尾蚴48 h仍有活性。     

血吸虫尾蚴侵染分子机制研究进展

尾蚴穿透宿主皮肤是血吸虫成功感染终宿主的第一步。尾蚴钻腺分泌的蛋白酶在穿透宿主皮肤过程中发挥了 重要作用。目前对于血吸虫感染分子机制的研究主要集中在包括丝氨酸蛋白酶和半胱氨酸蛋白酶在内的尾蚴分泌蛋白 酶上。已有研究表明, 曼氏血吸虫主要靠尾蚴分泌的弹性蛋白酶穿透宿主皮肤, 日本血吸虫则主要利用组织蛋白酶B2侵 入宿主体内。尾蚴入侵分子机制的阐明有助于新型血吸虫病疫苗的研制和药物靶点的发现。     

Blockage of skin invasion by schistosome cercariae by serine protease inhibitors.

Invasion of skin by schistosome cercariae is facilitated by a serine protease secreted from the acetabular cells of cercariae in response to skin lipid. Specific inhibitors of the protease, when applied to human skin in formulations designed to retain the inhibitor on and in the upper stratum corneum layers, block cercarial invasion of human skin. Both peptide-based, irreversible inhibitors and non-peptide, reversible inhibitors block cercarial invasion when applied in a propylene glycol:isopropyl alcohol (3:1) formulation in vitro. Arrest of cercarial invasion could be achieved even after immersion of treated skin in water for 2 hr. Peptide-based irreversible inhibitors in the presence of three different Topicare Delivery Compounds optimized arrest of cercarial invasion. The three Topicare Delivery Compounds applied alone prevented 80-100% of cercarial invasion. With inclusion of the inhibitor, there was 97-100% inhibition in vitro. The optimal formulation with inhibitor was then applied to the tails of BALB/c mice, and the mice were exposed to 120 cercariae by tail immersion. With the carrier lotion alone, there was a 50% reduction in worm burden and a 70% reduction in egg burden. When inhibitor was included, an 80% reduction in worm burden and a 92% reduction in egg burden was observed.     

Reduction of infectivity of schistosome cercariae by application of cercaricidal oil to water

Schistosomiasis continues to plague populations living in disease-endemic areas, and exposure to infective cercariae results in more than 200 million cases worldwide. Laboratory experiments were conducted to test whether a cercaricidal film applied directly to the water surface can reduce viability of cercariae. A distillate from inexpensive cedarwood oil enriched for cedrol in a mixed oil fraction was formulated (1:5) with the surfactant Tween 80. When applied to the surface of clean and turbid water in test vessels, the formulation spread across and just below the air-water interface, causing inactivation of Schistosoma mansoni cercariae within minutes. The active ingredient was heat stable and reduced schistosome survival and infectivity by 90% and 99.2%, respectively in a mouse model. The effective dose (13 mug/cm(2)) was dependent on surface area rather than volume of water treated. We conclude that application of the biodegradable formulation to the surface of schistosome-infested waters may be an effective, economical, and safe means of reducing human infections.