BackgroundSchistosomiasis has a considerable impact on public health in many tropical and subtropical areas. In the new world, schistosomiasis is caused by the digenetic trematode Schistosoma mansoni. Chemotherapy is the main measure for controlling schistosomiasis, and the current drug of choice for treatment is praziquantel (PZQ). Although PZQ is efficient and safe, its repetitive large-scale use in endemic areas may lead to the selection of resistant strains. Isolates less susceptible to PZQ have been found in the field and selected for in the laboratory. The impact of selecting strains with a decreased susceptibility phenotype on disease dynamics and parasite population genetics is not fully understood. This study addresses the impact of PZQ pressure on the genetics of a laboratory population by analyzing frequency variations of polymorphic genetic markers.MethodologyInfected mice were treated with increasing PZQ doses until the highest dose of 3×300 mg/Kg was reached. The effect of PZQ treatment on the parasite population was assessed using five polymorphic microsatellite markers. Parasitological and genetic data were compared with those of the untreated control. After six parasite generations submitted to treatment, it was possible to obtain a S. mansoni population with decreased susceptibility to PZQ. In our experiments we also observed that female worms were more susceptible to PZQ than male worms.ConclusionsThe selective pressure exerted by PZQ led to decreased genetic variability in S. mansoni and increased endogamy. The understanding of how S. mansoni populations respond to successive drug pressure has important implications on the appearance and maintenance of a PZQ resistance phenotype in endemic regions.

O processo de inclusão do aluno autista na escola nos tempos atuais tem-se mostrado deficiente, pois os professores da educação básica não estão preparados para lidar com alunos especiais em suas turmas, seja em classes regulares seja em classes especiais. Este estudo foi motivado, principalmente, pelas enormes dificuldades em se admitir a questão da inclusão na educação regular brasileira. E vem analisar a inclusão de um aluno autista matriculado em uma escola regular da rede municipal de Juiz de Fora (MG). A pesquisa de campo foi realizada baseada no estudo de caso. através de entrevistas semi-estruturadas com a mãe do aluno autista e três profissionais da Associação de Pais e Amigos dos Excepcionais (APAE). No espaço escolar, o estudo foi realizado através de dois questionários, um deles aplicado aos colegas do autista e outro aplicado a alguns professores. Através dos resultados, notou-se que na inclusão é necessário o desenvolvimento do aluno especial, como os demais alunos, salvo suas limitações. Sendo de total relevância a capacitação dos professores ao lidar com a inclusão.