Behavior of Schistosoma mansoni-induced histopathological lesions in Biomphalaria glabrata submitted to ionizing radiation

O presente trabalho demonstra que a irradia????o repetida, num total de 15.000 rads, resulta numa r??pida supress??o da elimina????o das cercarias em caramujos infectados pelo Schistosoma mansoni. Inicialmente os esporocistos desaparecem dos tecidos. As formas evolutivas das cercarias s??o mais resistentes e apresentam vacuoliza????o citoplasm??tica e condensa????o nuclear antes de desaparecerem. N??o foram observadas rea????es nos tecidos do hospedeiro. Trinta e quatro dias ap??s a ??ltima irradia????o, os caramujos voltam a eliminar cerc??rias. Numerosos esporocistos e cerc??rias em desenvolvimento aparecem infiltrando difusamente os tecidos ?? maneira de uma neoplasia maligna, sem sinais de oposi????o da parte do hospedeiro, a qual era vis??vel nos controles infectados e n??o irradiados. A regi??o do ovo-testis apareceu destru??da ap??s a radia????o, mas retornou ?? sua apar??ncia normal em torno de 40 dias mais tarde. A radia????o ionizante afeta tanto o hospedeiro como as formas em desenvolvimento do parasito, mas estas altera????es impressionantes s??o logo revers??veis.Present report demonstrates that repeated radiation of Schistosoma mansoni-infected Biomphalaria glabrata, totaling 15,000 rads, caused a sudden, albeit transient, suppression of cercarial shedding. Initially, sporocysts practically disappeared from the snail tissues. The more resistant developing cercariae presented nuclear clumping and vacuolation, before undergoing lysis. No host tissue reaction was evident at any time. Thirty-four days after the last irradiation, the snails resumed cercarial elimination. By that time numerous sporocysts and developing cercariae were detected, disseminated throughout snail tissues in a pattern similar to that of a highly malignant neoplasm, with no signs of host cellular reactions, which on the other hand were present in non-irradiated infected controls. The region of the ovo-testis was apparently destroyed after radiation, but returned to its normal appearance around 40 days after the last radiation. Ionizing radiation affected both host and parasite in S. mansoni-infected Biomphalaria glabrata, but the resulting impressive changes were soon reversed