Effect of sub-diaphragmatic vagotomy on gastric mucosal mast cell population in pylorus ligated rats.

Gastric mucosal mast cell population was studied following sub-diaphragmatic vagotomy in albino rats, 6 and 12 h after pylorus ligation. Sub-diaphragmatic vagotomy significantly increased the gastric mucosal mast cell population in both 6 and 12 h groups, the increase being more in the latter. The results suggest that the vagal impulses act on the gastric mucosal mast cells causing their degranulation. Following vagotomy the contents stay bound within the mast cells. Increase in mast cell population with the longer experimental situation was possibly due to the continuation of normal turnover of the mast cells in the gastric mucosa. The present study, however, does not lead to a conclusion that the vagal influence on mast cell population is similar throughout the gastro-intestinal tract.     

An experimental model of ameboma in guinea pig.

Among the wide variety of clinicopathological manifestations of intestinal amebiasis, amebomas occur rarely and their pathogenesis is not well understood. When cholesterol-fed, 2- to 4-week-old guinea pigs were infected intracecally with a virulent, monoaxenic strain of Entamoeba histolytica, gross and histologically characteristic amebomas developed in 85% of the animals by the 3rd day, in 94% by the 9th day, and in 96% by the 12th day postinfection, by which time most of them had died. Amebomas were confirmed by histopathology. Thus, a model of consistent production of amebomas was documented.     

Studies on metabolism of vitamin A. The effect of the stage of vitamin A deficiency on sulphate activation in rat liver

1. The synthesis of ;active sulphate' in rat liver was studied at various stages of vitamin A deficiency, with the corresponding pair-fed controls. 2. The activity was significantly decreased even at the onset of the deficiency, and at the acute stage there was further loss. 3. Only at the earlier stages of the deficiency was the addition of retinol, in vitro, fully effective in restoring the lost activity; retinoic acid was partially active. No such restoration was possible at the acute deficiency stage.     

Effect of nifedipine administration on the functional capacity of neutrophils

Administration of nifedipine to mice over a period of six months caused a significant (p<0.05) decrease in neutrophilic functions viz superoxide generation, coupled to NADPH oxidase activity as well as NADPH production by HMP shunt. Properties like chemotaxis and phagocytosis showed a similar decrease. From this study, it is seen that nifedipine causes neutrophil functional abrogation which is therefore an apparent concern for the prolonged usage of the drug. However, relevance of the mouse model to clinical situation needs further investigation.