Browsing by Author "Japundzic, I. (7003832566)"

[No abstract available]

[No abstract available]

Duodenal ulcer could be induced in rats by a single subcutaneous injection of the anti-inflammatory agent mepirizole (M) or by the alkyl chemical propionitrile (P). Contrary to M, P provokes HCl hypersecretion as well. We used these animal models of duodenal ulcer to study the preulcerogenic molecular changes in the mucosal cells and their causal relationship to HCl hypersecretion. It was found that M and P induced the dose- and time-dependent decrease of duodenal alkaline phosphatase (DAP) activity. The decrease was detected at 4 h, with a nadir at 12 h after the injection of both drugs. The decrease of alkaline phosphatase activity was organ-specific after P administration and it was even regional-specific along the small intestine after M administration. At the level of mucosal cells of duodenum the effect of the ulcerogens was enzyme-selective. Both ulcerogens decreased protein and alkaline phosphatase activities; however, they had no effect on lysosomal acid phosphatase. Contrary to cysteamine (C), the effect of M and P on DAP depletion could not be reproduced under in vitro conditions. An interference of P and a slight additive effect of C on DAP depletion after simultaneous subcutaneous administration with M to the rats was found. The results indicate that the DAP depletion after in vivo administration of the three duodenal ulcerogens could be provoked by at least two different mechanisms. The decrease of DAP activity seems to be a general property of the duodenal ulcerogens independent of their effects on gastric acid secretion or on the suppression of alkaline secretion in the duodenum. As a late molecular event most probably elicited by the early morphological changes, the decrease of DAP activity could rather be related to ulcer healing than to its pathogenesis.

Pregnenolone 16α carbonitrile (PCN), in daily doses of 20 mg/100 g body weight, exerted a marked stimulative effect on the rat thyroid. The uptake of radioiodine in animals receiving PCN was increased. Chromatographic investigations showed that in PCN treated animals the biosynthesis of thyroid hormones was accelerated. There is evidence of histophysiological activation of the TSH cells of the adenohypophysis. It was concluded that there was no inhibition of the synthesis of thyroid hormones and that activation of the pituitary thyroid axis under the influence of PCN, resulted from alteration of the peripheral metabolism of thyroxin.

An experimental study was carried out to evaluate the protective role of an endoluminal prosthesis on high risk colo-colonic anastomoses. One hundred and fifty rats were divided into two groups: Group E with endoluminal latex prosthesis and Group C without. Bursting pressure and collagen concentration in the perianastomotic tissue were tested, respectively, on the 4th, 7th and 12th, and 4th, 7th, 12th, 18th and 38th post-operative days. Bursting pressure was significantly higher in Group E on the 4th postoperative day. There was no significant difference in the anastomotic collagen concentration between the two groups. The presence of the prosthesis did not produce any macroscopic or microscopic evidence of impaired healing or stricture at the suture line. Death due to anastomotic dehiscence occurred in 11/75 (15%) in Group C and in 1/75 (1.3%) in Group E (p<0.010). Endoluminal prosthesis appears to have a protective effect on anastomotic healing. The mechanism is probably due to mechanical protection and not to differences in collegen concentration. © 1991 Springer-Verlag.

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[No abstract available]