Kassim O O, Dean D A, Mangold B L, Von Lichtenberg F
Department of Microbiology, Howard University College of Medicine, Washington, DC.
Am J Trop Med Hyg. 1992 Aug;47(2):231-7. doi: 10.4269/ajtmh.1992.47.231.
Combined microautoradiographic and histopathologic methods were used to locate and examine schistosomula of Schistosoma mansoni in the lungs of irradiated cercaria-immunized mice 21 days after percutaneous challenge infection with 75Se-labeled cercariae. Of 75 schistosomula examined in serial sections, 53% were located in the pulmonary microvasculature, 23% in alveolar spaces, 3% with one end in a vessel and the other in an alveolar space, and the locations of 21% were not identified. Inflammatory reactions of variable intensity were observed around schistosomula in both vascular and alveolar sites, although the most intense category of reactions was associated almost entirely with alveolar larvae. All autoradiographic foci contained recognizable schistosomula. Although the concentration of reduced silver grains precluded cyto-structural analysis, observations on schistosomular contour and shape provided no evidence of larval damage. Our findings suggest that immune elimination of schistosomula in mice immunized with irradiated cercariae is partly or largely effected by a process of alveolar extrusion of viable parasites during their lung migration.
采用联合显微放射自显影和组织病理学方法，对经75Se标记尾蚴经皮攻击感染21天后的照射尾蚴免疫小鼠肺内曼氏血吸虫童虫进行定位和检查。在连续切片中检查的75条童虫中，53%位于肺微血管内，23%位于肺泡腔，3%一端在血管内另一端在肺泡腔，21%的位置未确定。在血管和肺泡部位的童虫周围均观察到不同强度的炎症反应，尽管最强烈的反应几乎完全与肺泡内的幼虫有关。所有放射自显影病灶均含有可识别的童虫。虽然还原银颗粒的浓度妨碍了细胞结构分析，但对童虫轮廓和形状的观察未发现幼虫受损的证据。我们的研究结果表明，用照射尾蚴免疫的小鼠体内童虫的免疫清除部分或很大程度上是由活寄生虫在肺内移行过程中通过肺泡挤出的过程实现的。
