title: Natural Schistosoma mansoni infection in Nectomys squamipes: histopathological and morphometric analysis in comparison to experimentally infected N. squamipes and C3H/He mice.
abstract: Histopathologic and morphometric (area, perimeter, major and minor diameters) analysis of hepatic granulomas isolated from twelve naturally infected Nectomys squamipes were compared to four experimentally infected ones and six C3H/He mice. Liver paraffin sections were stained for cells and extracellular matrix. Both groups of N. squamipes presented peculiar granulomas consisting predominantly of large macrophages, full of schistosome pigment, characterizing an exudative-macrophage granuloma type, smaller than the equivalent granuloma type in mouse. Naturally infected animals exhibited granulomas in different stages of development, including large number of involutional types. Morphometric analysis showed that all measurements were smaller in naturally infected animals than in other groups. The results demonstrated that both N. squamipes groups reproduced, with small variations, the hepatic granuloma aspects already described in cricetidium (Calomys callosus), showing a genetic tendency to set up strong macrophage responses and small granulomas. Unexpectedly, natural infection did not engender distinguished histopathological characteristics distinct from those derived from experimental single infection, showing changes predominantly secondary to the duration of infection. It appears that the variability of the inocula (and the number of infections?) interfere more with the quantity than with the quality of the pathological changes, denoting some morpho-functional determinism in the response to schistosomal infection dependent on the animal species.
authors.affiliation: Departamento de Patologia e Laboratórios, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, 20550-170, Brasil. machado@uerj.br
authors.forename: Michele
authors.initials: M
authors.lastname: Costa-Silva
authors.forename: Rosângela
authors.initials: R
authors.lastname: Rodrigues-Silva
authors.forename: Maarten
authors.initials: M
authors.lastname: Hulstijn
authors.forename: Renata Heisler
authors.initials: RH
authors.lastname: Neves
authors.forename: Mônica
authors.initials: M
authors.lastname: de Souza Panasco
authors.forename: Henrique Leonel
authors.initials: HL
authors.lastname: Lenzi
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Machado-Silva
mesh_terms: D000818:Animals; D005243:Feces / Q000469:parasitology; D006099:Granuloma / Q000469:parasitology / Q000473:pathology / Q000662:veterinary; D008099:Liver / Q000469:parasitology / Q000473:pathology; D008109:Liver Diseases, Parasitic / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D008264:Macrophages; D051379:Mice; D008809:Mice, Inbred C3H / Q000469:parasitology*; D009115:Muridae / Q000469:parasitology*; D010270:Parasite Egg Count; D012376:Rodent Diseases / Q000469:parasitology / Q000473:pathology*; D012555:Schistosomiasis mansoni / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*