Pneumocystis carinii: recognition of the infection in albino rats using different stains.

Pneumocystis carinii is a commensal protozoan which may cause pneumonia in hosts with compromised immune status and may end fatally. Since effective management of pneumocystic pneumonia depends on rapid and accurate recognition of the disease, so, the present study aims to throw lights on the best staining method for cytodiagnosis of this organism with the sequential pathological changes in the infected lungs. An immunosuppression state was induced in albino rats for 6-8 weeks then rats were sacrificed weekly & lungs were examined for infection using different stains. In stained smears, intracystic bodies have been identified using Giemsa, Papanicolaou & Toluidine blue stains. On the other hand, cysts were inspected in paraffin sections using Gomori methenamine silver nitrate (GMS) & weight gram stains. Histopathologically, in sections stained with H & E, features of Pneumocystis carinii pneumonia were obvious, foamy exudation, inflammatory infiltration formed mainly of histiocytes, plasma cells, lymphocytes, thickening of alveolar septa and lastly formation of hyaline membrane in some alveoli.

Oral contraceptive pills in experimental schistosomiasis mansoni: parasitological, biochemical, histopathological and ultrastructural studies.

This study examines the effect of intake of oral contraceptive steroid in S. mansoni infected mice as regards parasitological, biochemical, histopathological and ultrastructural changes. Three groups were studied group I: S. mansoni infected mice received contraceptive pills six weeks post-infection (p.i.), group II: S. mansoni infected control and group III: non-infected control. Administration of oral contraceptive pills to S. mansoni infected mice results in significant reduction in tissue egg count with a high percentage of dead eggs as observed in the oogram study. There was statistically significant increase in all parameters of the hepatic functions except the prothrombin activity which showed significant decrease. Histopathological examination revealed less cellular granulomas with marked fibrosis, foci of hyperplastic changes in the liver cells and accentuation of cellular degenerative changes. On the subcellular level, there were marked proliferation and dilatation of rER and SER, evident increase of ribosomes, alteration in mitochondrial cristae with intra luminal inclusions and increase glycogen content of hepatocytes.