El objetivo del presente estudio fue evaluar las alteraciones histopatológicas de las placentas provocadas por la infección materna durante la preñez con diferentes cepas de Trypanosoma cruzi. Ratones preñadas, de 60 días de edad, fueron inoculadas por la via intraperitoneal (i.p.) con 2 x 105 tripomastigotes sanguíneos de las cepas colombiana, Y, Bolivia o RC del T. cruzi. Los resultados mostraron que las cepas Bolivia y RC presentan mayor histotropismo por las células placentarias del ratón que las cepas colombiana e Y. El proceso inflamatorio afectó la decidua basal en todos los grupos de ratones infectados, mientras que la cepa colombiana causó intensa degeneración de la decidua basal, con células inflamatorias escasas o ausentes. Las placentas de todos los grupos infectados presentaron áreas de edema, degeneración, necrosis y calcificación, principalmente en la decidua basal. En los animales inoculados con la cepa RC del T. cruzi también fue afectado el trofoblasto de la zona esponjosa. El parasitismo más intenso fue observado en los animales infectados con las cepas Bolivia y RC, envolviendo todas las zonas placentarias, incluso las células trofoblásticas gigantes y el trofoblasto esponjoso. Los resultados permiten concluir que las placentas sufren procesos patológicos diferentes, característicos para cada cepa del T. cruzi.

The objective of the present study was to evaluate the histopathological alterations of the placenta provoked by maternal infection during pregnancy by different Trypanosoma cruzi strains. Pregnant mice, 60 day-old, were i.p. inoculated with 2 x 105 bloodstream trypomastigotes of colombian, Y, Bolivia or RC strains of T. cruzi. The results demonstrated that the Bolivia and RC strains showed higher histotropism for the mouse placental cells than the colombian or Y strains. The inflammatory process in all the infected groups involved the basal decidua, but the colombian strain caused intense decidual degeneration, with rare or absent inflammatory cells. Placentas from all the infected groups displayed aéreas of edema, degeneration, necrosis and calcification, mainly in the basal decidua, but the group infected by the RC strain showed also involvement of the spongiotrophoblast. The highest parasitism was observed with the Bolivia and RC strains, involving all the placenta zones, including the trophoblast giant cells and the spongiotrophoblast. The results show that placentas undergo differentiated pathological processes, characteristic for each strain.

The objective of this work was to evaluate karyometrically the alterations caused by different strains of Trypanosoma cruzi in the mouse placenta. Pregnant mice, 60-day oíd, were intraperitoneally inoculated with 2 x 10(5) bloodstream trypomastigotes of the Colombian, Y, Bolivia or RC strain of T cruzi. There were observed clear differences in the karyometric alterations of the trophoblast giant cells and in the spongiotrophoblast cells. The results demónstrate that the Colombian and RC strains cause alterations both in the trophoblast giant cells and in the spongiotrophoblast cells, whereas the Y and Bolivia strains provoke alterations only in the trophoblast giant cells. It is possible concluding that each strain has its own characteristics and that, in spite of the similar type of transmission, it show differential nuances in the placental pathogenic process.

El objetivo de este trabajo fue evaluar cariometricamente las alteraciones causadas por diferentes cepas de T. cruzi en la placenta del ratón. Ratones hembras de 60 días, grávidas, fueron inoculadas, intraperitonealmente, con 2 x 10(5) tripomastigotes sanguíneos de las cepas colombiana, Y, Solivia o RC del T. cruzi. Fueron observadas claras diferencias en las alteraciones cariométricas de las células trofoblásticas gigantes y de las células trofoblásticas de la zona esponjosa. Los resultados demostraron que las cepas colombiana y RC causan alteraciones tanto en las células trofoblásticas gigantes como en las células del trofoblasto esponjoso, mientras que las cepas Y y Bolivia provocan alteraciones solamente en las células trofoblásticas gigantes. Es posible concluir que cada cepa posee características propias y que, a pesar del tipo similar de transmisión, presenta matices diferenciales en el proceso de la patogénesis placentaria.

The objective of this work was to evaluate the effects of the acute maternal infection with different strains of Trypanosoma cruzi on the intrauterine growth of the mouse fetus. Pregnant mice, 60 day-old, were i.p. inoculated with 2 x 10(5) trypomastigotes blood stream of T. cruzi (Colombian, Y, Bolivia or RC strains). The results allow to conclude that the T. cruzi infection affect the intrauterine growth of the mouse fetus, with reduction of both weight and length, umbilical cord length, body weight to placenta weight ratio and body weight to umbilical cord length ratio. T. cruzi strains showed different behavior. In general, the less prejudicial to the fetal growth was the RC strain, whereas the most prejudicial were the Bolivia and Y strains. The parasitemic curves of these strains show the most rapid growth, reaching the peak at the 5th and 7th day, respectively. As inoculation was made to agree the last pregnancy day with the parasitemic peak, the infected animals had the most rapid infection with elevated parasitemy, without possibility of maternal adaptation

El objetivo de este trabajo fue evaluar los efectos de la infección aguda materna con diferentes cepas de T. cruzi sobre el crecimiento intrauterino del ratón. Animales grávidos, de 60 días, fueron inoculados i.p. con 2 x 10(5) tripomastigotes sanguíneos de T. cruzi (cepa colombiana, Y, Bolivia o RC). Los resultados muestran que la infección afecta el crecimiento intrauterino, con reducción de peso y de longitud del cuerpo, longitud del cordón umbilical, relación peso corporal/peso placentario y relación peso corporal/longitud del cordón umbilical. Las cepas usadas muestran comportamiento diferente. En general, la menos perjudicial para el crecimiento fue la cepa RC, mientras que las más deletéreas fueron las cepas Bolivia e Y. Las curvas parasitemicas de estas cepas tienen el crecimiento más rápido, alcanzando el máximo al 5º y 7º día, respectivamente. Como la inoculación fue hecha de modo a coincidir los niveles máximos de parasitemia con el fin de la gravidez, estas cepas causan un proceso infeccioso más rápido, con altos índices de parasitemia, sin permitir la adaptación materna

Camundongos suíços prenhes(Mus musculus)foram inoculados, intraperitonealmente, com 2 x 10(5) tripomastigotas da cepa RAL de Trypanosoma cruzino 7º dia da prenhez e sacrificados no 19º dia da prenhez. Foram realizados cortes histológicos para avaliar as alterações histológicas e morfométricas das placentas. A cepa RAL mostrou intenso tropismo pela placenta, com parasitismo atingindo as três camadas placentárias. Houve envolvimento da parte materna e fetal das placentas, bem como das células gigantes e dos espongioblastos. As placentas dos animais infectados apresentaram escassas áreas de degeneração e necrose, com calcificação distrófica exígua na decídua. O processo inflamatório era constituído de plasmócitos e linfócitos, revelando comprometimento da decídua. O estudo citométrico das células trofoblásticas gigantes mostrou que as placentas do grupo infectado foram bastante afetadas, inclusive no que se refere ao volume celular. As alterações provocadas pela cepa RAL sobre as células trofoblásticas e a diferença de comportamento observado nas populações celulares das diversas regiões placentárias podem afetar o desenvolvimento intra-uterino, provavelmente por uma produção deficiente de hormônios, tais como o lactogênio placentário, que atua como hormônio de crescimento fetal, ou indiretamente, mediante uma invasão decidual deficiente causada por uma vascularização útero-placentária ineficiente, prejudicando desta maneira a nutrição fetal.

Pregnant Swiss mice (Mus musculus) were inoculated intraperitoneally with 2 x 10(5) trypomastigotes of the RAL strain of Trypanosoma cruzi on the 7th day of pregnancy and sacrificed on the 19th day of pregnancy. The placenta was sectioned for the assessment of histological and morphometric changes. The RAL strain showed intense tropism for the placenta, with parasitism reaching the three placental layers. There was involvement of the maternal and fetal portions of the placentas, and also of giant cells and spongioblasts. The placentas of infected animals presented sparse areas of degeneration and necrosis, with mild dystrophic calcification of the decidua. The inflammatory process consisted of plasmocytes and lymphocytes, revealing involvement of the decidua. Cytometric study of giant trophoblastic cells showed that the placentas of the infected group were seriously affected, also with respect to cell volume. The changes provoked by the RAL strain in the trophoblastic cells and the difference in behavior observed in the cell population of the various placental regions may affect intrauterine development, probably by a deficient production of hormones such as placental lactogen, which acts as a fetal growth hormone, or indirectly by deficient tissue invasion caused by inefficient utero-placental vascularization, thus impairing fetal nutrition.

Fez-se o estudo histopatológico e imuno-histoquímico sistematizado do encéfalo e coração de 50 pacientes com forma crônica cardíaca de doença de Chagas. A técnica imuno-histoquímica empregada foi o método da peroxidase-antiperoxidase adaptado para a demonstração de formas amastigotas do T. cruzi. O exame histológico e imuno-histoquímico do encéfalo revelou, em 4 casos (8%), encefalite em focos múltiplos, não sistematizados. Num dos casos o processo era recente, em atividade, contendo parasitas. Nos outros três casos as lesões eram de menor intensidade, com fenômenos exsudativos discretos, sugerindo tratar-se de processo em extinção ou já inativo. A pesquisa de parasitas nestes três casos, mesmo com o uso da imunoperoxidase, foi negativa. O estudo histológico e imuno-histoquímico do coração mostrou, além da miocardite crônica em focos múltiplos acompanhada de fibrose endomisial, amastigotas em 7 casos (14%). A ausência de parasitas e de processo inflamatório no eneéfalo da grande maioria dos chagásicos crônicos, contrastando com o achado constante de lesões inflamatórias e o encontro ocasional de amastigotas no mio-cárdio destes mesmos pacientes, permite afirmar, de modo semelhante a outros autores, que não há base histopatológica para que se possa admitir a existência da forma crônica nervosa da doença de Chagas.

A histopathological and immunohistochemical study of the brain and heart was made in 50 patients with the chronic cardiac form of Chagas' disease. The immunohistochemical technique used was the peroxidase-antiperoxidase method adapted for the demonstration of the T. cruzi amastigotes. Histological and immunohistochemical examination of the brain showed encephalitis in multiple foci, although sparse, in four patients (8%). In one of the patients the process was recent, active, and containing parasites. In the other three patients, the lesions were of minor intensity, with light exudative inflammatory changes, suggesting a process becoming inactive, or already inactive. The search for parasites in these three patients was negative, even with use of immunoperoxidase. The heart histological and immunohistochemical study showed, besides the chronic myocarditis in multiple foci associated with interstitial fibrosis, amastigotes in seven patients (14%). The absence of parasites and of inflammatory changes in the brain in the great majority of patients with chronic Chagas' disease, contrasting with the constant finding of inflammatory changes and the occasional finding of amastigotes in the myocardium of the same patients, allows us to state, in the same way other authors did, that there is no histopathological basis to support the existence of the chronic nervous form of Chagas' disease.