Histoarchitecture of schistosomal granuloma development and involution: morphogenetic and biomechanical approaches

The authors present morphogenetic and biomechanical approaches on the concept of the Schistosoma mansoni granulomas, considering them as organoid structures that depend on cellular adhesion and sorting, forming rearrangement into hierarchical concentric layers, creating tension-dependent structures, aiming to acquire round form, since this is the minimal energy form, in which opposing forces pull in equally from all directions and are in balance. From the morphogenetic point of view, the granulomas function as little organs, presenting maturative and involutional stages in their development with final disappearance (pre-granulomatous stages, subdivided in: weaky and/or initial reactive and exudative; granulomatous stages: exudative-productive, productive and involutional). A model for the development of granulomas was suggested according to the following stages: encapsulating, focal hystolysis, fiber production, orientation and compacting and involution and desintegration. The autors concluded that schistosomal granuloma is not a tangled web of individual cells and fibers, but an organized structure composed by host and parasite components, which is not formed to attack the miracidia, but functions as an hybrid interface between two different phylogenetic beings.

The murine "air pouch" model: a sequential morphologic study of its formation

Light and electron microscopy coupled to Laser scanning confocal microscopy and immunohistology (for adhesion detection, revealed that in its development, the air pouch produced in mice, starts as a traumatic event in where is produced a subcutaneous air space surrounded by compressed pre-existing connective issue. It soon matures toward a well circunscribed air pouch, acquiring an epithelial-looking lining suported by newly synthesized connective tissue layers. We recognized three developmental stages and considered they should be taken in account in experimental designs making use of the air pouch model. The capability of the air pouch lining to express adhesion molecules, its easy manipulation and its situation as an isolated comportament turns the air pouch a good alternative model to the coelomatic cavities.

Epidemia de toxoplasmose do sistema nervoso central em enfermos com AIDS na cidade do Rio de Janeiro / An epidemy of CNS toxoplasmosis in patients with AIDS in Rio de Janeiro city-Brazil

O comprometimento do SNC foi analisado em 19 pacientes com AIDS, sendo 11 hemofílicos, seis homossexuais e dois bissexuais. Onze enfermos da série apresentaram toxoplasmose do SNC. O diagnóstico foi estabelecido por pesquisa do IgG e IgM específicas no soro e no líquor, por tomografia computadorizada, biopsia cerebral e exame histopatológico post-mortem. Desde 11 pacientes com infecçäo neurológica central pelo T. gondii, apenas cinco beneficiaram-se, ainda com vida, do diagnóstico patológico, recebendo, portanto, tratamento específico e recuperando-se desta doença. Os autores mostram que o aparecimento de um grande número de casos desta condiçäo patológica num curto espaço de tempo caracteriza surto epidêmico. Argumentam ainda que o acometimento do SNC pelo T. gondii deve ser suspeitado em todo enfermo com AIDS que apresente sinais de envolvimento neurológico, enfatizando que a toxoplasmose do SNC pode ser a primeira expressäo da síndrome