Morphological and ultrastructural redescription of Calyptospora serrasalmi Cheung, Nicrelli & Ruggieri, 1986 (Apicomplexa: Calyptosporidae), a parasite found in two new host species of the genus Serrasalmus

Coccidians are pathogenic protoparasites found in various fish species. In this report, we used light and electron microscopy to study the morphological and ultrastructural features of Calyptospora serrasalmi, a coccidian parasite found to parasitize two additional species of the teleostean genus Serrasalmus, S. striolatus and S. rhombeus, from the Amazon river and the lagoonal region of Recife, Brazil, respectively. Infection involved only the liver parenchyma, with the coccidians occurring as isolated oocysts or in clusters of up to 40-50 oocysts encapsulated by a layer of connective tissue. Several life cycle stages were observed in the same section, with oocysts being the most evident. Each spherical oocyst (~25.5 um in diameter) contained four sporocysts, each surrounded by a thin membranous veil. The sporocysts were pear-shaped (11.8x6.0 um) with an attached apical sporopodium that had several small lateral projections (up to 0.5 um long). These small projections were formed by the same material as the sporocyst wall and were distributed over the basal portion of the wall in 10-12 longitudinal series. The sporocysts lacked a Stieda body and contained two vermiform sporozoites. Calyptospora serrasalmi was distinguishable from previously described species on the basis of sporocyst morphology.

Fine structure of the oocyst of Nematopsis mytella (apicomplexa, porosporidae),a parasite of the mussel Mitella falcata andof the oyster crassostrea rizophorae (Mollusca, Bivalvia)from the northeastern atlantic coast of Brasil

Oocystsof Nematopsis mytella, an apicomplexa gregarine parasite of the mussel Mytella falcata (fam. Mytelidae) and of the oyster Crassostrea rizophorae (fam. Ostreidae). Were collected from Itamaracá Island and Suape, two distinct zones in the estuarine region of the northeastern coast of Brazil, near the city of Recife. The oocysts were examined by light and transmission electron microscopy. No morphological and ultrastructural differences were observed between oocysts the two host species. The oocysts were engulfed by the cytoplasm of host phagocytes, with each phagocyte containing 1-19 oocysts (usually 3-5). Each oocyst was located in the center of a spherical to ellipsoidal parasitophorous vacuole (PV) 20-25 um in diameter. The oocyst (13.2 um long and 8.4 um wide) consisted of an external wall 0.6 um thich surrounded by an internal, uninucleated sporozoit. The apical region of the wall of each oocyst contained a circular micropyle 0.8 um in diameter covered by an operculum. The oocyst wall was connected to the PV membrane by a complex network of anastomosed microfibrils. The PV matrix contained 1-2 dense bodies and the periphery was occupied by numerous glycogen particles. This is the first record of a Nematopsis sp. from the northeastern coast of Brazil and only the second from Brazil as a country.

Utilizaçäo de artéria bovina tratada pelo glutaraldeido em aorta abdominal de cäo: análise morfológica de nove enxertos após 196 dias de implantaçäo / Use of bovine artery treated by glutaraldehyde in abdominal aorta of the dog: morphological analysis of 9 grafts after 196 days of implantation

Nove cäes mestiços adultos foram submetidos a interposiçäo de segmento de artérias bovina em aorta abdominal infrarrenal. Os segmentos arteriais foram preparados a partir da artéria torácica interna, as quais foram colocadas em soluçäo salina gelada, até transporte para o laboratório, onde era feita a retirada do tecido conjuntivo e adiposo perivascular e ligadas as colaterais. A seguir, usando-se o aparelho apresentado por KAPLAN e col., as artérias foram fixadas em sol. de glutaraldeído a 0,65//, objetivando-se a avaliaçäo da eficácia deste método, através de análise morfológica dos enxertos com mais de seis meses de implantaçäo. Após este período os animais foram sacrificados para retirada do enxerto. Foi encontrada como achado mais marcante, rigidez de seis enxertos, a qual correspondia à calcificaçäo nas preparaçöes histológicas. Dois animais evoluíram com trombose dos enxertos, a qual ocorreu gradativamente, com formaçäo de rica circulaçäo colateral. Nenhum caso de aneurisma, infecçäo ou rejeiçäo do enxerto foi registrado. Hiperplasia de íntima em dois casos, discreta reaçäo inflamatória linfo-plasmacitária perienxerto e tendência a hialinizaçäo em todos foram os achados dos microscópicos mais marcantes. Conclui-se que a metodologia empregada foi eficaz em evitar reaçäo de rejeiçäo, degeneraçäo, dilataçäo e infecçäo em todos os casos, com ocorrência de clacificaçäo em dois terços dos casos, mas proporcionando uma boa aceitaçäo do enxerto pelo hospedeiro

Schistosoma mansoni: structural damage after treatment with oxamniquine

The effects of a single dose (100 mg/kg-body weight of mouse) of oxamniquine on the worm's tegument and paranchyma in relation to the process of immunological granulomatous reaction of the host's liver are described under light and electron microscopy (EM). The lesions caused by the drug are sequentially and simultaneously described in form of swelling, surface bulble and disruption with erosions. Ulceration in the tubercules with loss of spines is often more extensive and severe in male worms and concentration of host's mononuclear cells is observed. The possible role of host's immune response is discussed.

Estudo quantitativo e morfométrico das vesículas "pinocíticas" dos capilares pulmonares do rato em situaçäo normal e de edema agudo / Quantitative and morphometric study of lung capillary \"pinocytic\" vesicles of rats in normal condition and in acute edema

Vesículas "pinocíticas" do endotélio capilar alveolar do pulmäo de rato foram estudadas quantitativamente e por técnicas morfométricas. Em casos de edema pulmonar induzido pela alfa-naftil-tiouréia, näo se observou aumento numérico mas, apenas, volumétrico das vesículas em relaçäo a animais controles. Esta alteraçäo de volume pode traduzir aumento de transporte de fluido e também constituir a fase inicial de processo degenerativo que leva a vacúolos e bolhas citoplasmáticas, comumente encontrados nos edemas pulmonares. Nos pulmöes normais, bem como naqueles com edema, verificaram-se quatro padröes populacionais de vesículas, que fortalecem a hipótese de que estas estruturas näo constituem um único tipo de organela, mas, sim, vários e com funçöes distintas. Recomenda-se substituir o termo "vesículas pinocíticas" por "vesículas citoplasmáticas", a fim de evitar a limitaçäo funcional sugerida por aquela denominaçäo