Estudo quantitativo e qualitativo dos plexos de Auerbach e Meissner do esôfago de cäes inoculados com o Trypanosoma cruzi / A quantitative and qualitative study of the Auerbach and Meissner plexus in dogs inoculated with Trypanosoma cruzi

A quantitative and qualitative study was conducted on the Auerbach and Meissner plexuses of the esophagus of four chagasic dogs sacrificed during the acute phase of infection. Ganglionitis and periganglionitis of the Auerbach plexus ranged from mild to moderate and induced significant neuronal lesions, especially in two animals. The ganglions of the Meissner plexus were observed in small number which did not permit any analysis. Mild or moderate myositis was observed mainly in the lower third of the esophagus and was rarely associated with amastigote nests. Ganglion and neuron counts did not demonstrate denervation. Although the formation of megaesophagus was not induced in any dog, lesions of the Auerbach plexus and myocells of the esophagus were observed during the acute phase of chagasic infection. To our knowledge, this is the first systematic quantitative and qualitative study of the Auerbach and Meissner plexuses of the esophagus in experimental trypanosomiasis cruzi.

Experimental Chagas' disease in dogs

This paper describes the development of experimental Chagas' disease in 64 out-bred young dogs. Twenty-nine animals were inoculated with the Be-62 and 35 with Be-78 Trypanosoma cruzi strains. Twenty-six were infected with blood trypomastigotes by different inoculation routes and 38 with metacyclic trypomastigotes from the vector via the conjunctival route. Twenty of the 26 dogs infected with blood trypomastigotes were autopsied during the acute phase. Eleven died spontaneously and nine were sacrificed. Six remained alive until they died suddenly (two) or were autopsied (four). Twelve of the 38 dogs infected with metacyclic trypomastigotes evolved naturally to the chronic phase and remained alive for 24-48 months. The parasitemia, clinical aspects and serology (IgM and IgG) as well as electrocardiogram, hemogram and heart anatomo-histopathologic patterns of acute and chronic cardiac forms of Chagas' disease as seen in human infections, were reproduced. The most important finding is the reproductibility of diffuse fibrosing chronic chagasic cardiopathy in all dogs infected with Be-78 T. cruzi strain autopsied between the 90th and 864th days of infection. Thus, the dog can be considered as a suitable experimental model to study Chagas' disease according to the requisites of the World Health Organization (1984). Futhermore the animal is easily obtained and easy to handle and maintain in experimental laboratory conditions

Fase crônica cardíaca fibrosante da tripanossomíase cruzi experimental no cäo / Fibrosing cardiac chronic phase in experimental Chagas' disease in dogs

Os autores documentan a cardiopatia difusa fibrosante, com todos os sintomas clínicos e dados de autópsia pertinente a insuficiência cardíaca congestiva, em um dos 21 cäes infectados com a cepa Colombiana (cinco morreram na fase aguda e quatro continuam vivos) e cinco, dos 13 infectados com a cepa Berenice-78 (oito morrerm na fase aguda), num período de oito anos de observaçäo. Em vista destes resultados, os autores sugerem que o cäo possa vir a ser um modelo experimental, adequado par o estudo da história da doença de Chagas, preenchendo os requisitos estabelecidos pelo Comitê Assessor de Doença de Chagas do Programa Especial de Pesquisa e Treinamento em Doenças Tropicais da Organizaçäo Mundial de Saúde

Envolvimento renal na associaçäo Salmonella-Schistosoma mansoni / Renal involvement in the association of Salmonelosis with Schistosoma mansoni

Vinte pacientes com a associaçäo Salmonella-S. mansoni (Grupo 1) e 20 com esquistossomose mansoni hepatesplênica (Grupo 2) foram selecionados para o estudo. Submeteram-se os pacientes dos Grupos 1 e 2 a exame clínico minucioso e a uma série de exames complementares, com destaque para as provas de funçäo renal. Em 10 pacientes do Grupo 1 e 20 do Grupo 2, realizou-se, ainda, estudo histológico do rim à microscopia óptica, de fluorescência e eletrônica. As alteraçöes renais foral mais freqüentes nos pacientes do Grupo 1. Após o tratamento dos pacientes do Grupo 1, com antibióticos e/ou esquistossomicidas, observou-se regressäo das alteraçöes renais sob o ponto de vista clínico, laboratorial e imunopatológico. Os autores concluem pela existência de duas nefropatias distintas: a nefropatia esquistossomótica e a encontrada em pacientes com a associaçäo Salmonella-S. mansoni

Alteraçöes quantitativas das células neuroendócrinas no megacólon chagásico / Quantitative changes in the neuroendocrine cells of chagasic megacolon

Utilizando-se técnicas histoquímicas pela prata (Masson-Fontana e Sevier-Munger) estudaram-se a distribuiçäo e o número de células enterocromafins (EC) e do conjunto EC mais células argirófilas (ARG) em peças cirúrgicas de megassigmóide chagásico. Observou-se que tanto nos "megas" (n = 16) como nos controles (n = 8), a posiçäo das células EC e ARG na mucosa foi predominantemente basal, com distribuiçäo irregular, principalmente das EC. A análise histológica revelou aparente aumento numérico das EC e do conjunto EC mais ARG. Todavia, contagens sistematizadas mostraram que somente o conjunto dessas células apresentou aumento estatisticamente significativo (P<0,01). Realizou-se tambéjm o estudo morfométrico da mucosa e das musculares que revelou espessamento significativo (P<0,01) dessas camadas em relaçäo aos casos controles