[Polymorphism of collagen in duodenal mucosa of ulcers]

Determinations of collagen in specimens of duodenal mucosa taken from 15 patients operated on because of duodenal ulcer with pyloric stenosis were performed. In the ulcer and surrounding tissue, total collagen values were significantly increased when compared with the results in unchanged wall of the duodenum. Collagen polymorphism study showed considerably higher percentage of type I and decreased type III in the ulceration than in control duodenal mucosa. In conclusion, extracellular components of connective tissue may play a role in the formation and course of duodenal ulcer disease.

[The effect of some drugs on the levels of selected cytokines in experimental septic shock]

The production of tumor necrosis factor (TNF-alpha), and interleukin 1 beta (IL-1 beta), IL-6, sTNFR-p55, sTNFR-p75 and their pharmacomodulation were evaluated in a model of septic shock induced in CD-1 mice by cecal ligation and puncture (CLP). This model of sepsis, which resembles the clinical situation of bowel perforation and peritonitis with subsequent septic shock was compared with that induced by administration of pure endotoxin (LPS). TNF-alpha was detectable in serum, liver, spleen and lungs during the first 4 h, with a peak 2 h after CLP. IL-1 beta was measurable in serum after 24 h, and levels increased significantly in spleen and liver 4 and 8 h after CLP. IL-6 levels increased significantly in serum throughout the first 16 h after CLP. sTNFR-p55 and p75 increased in both models of shock but with different kinetics. Cytokines were also detectable after LPS injection, with kinetics similar to those after CLP but a significantly higher level. Pretreatment with dexamethasone (DEX) and ibuprofen (IBU), significantly reduced survival, while TNF did not affect it. Only pentoxifylline (PTX) significantly increased survival in mice with CLP. However DEX protected the mice from LPS mortality. In conclusion, by inhibiting TNF-alpha with DEX and PTX survival was reduced or unchanged respectively, suggesting that the modulation of this cytokine does not play significant role in sepsis and septic shock induced by CLP, unlike treatment with LPS. The negative effects of IBU suggests a protective role by prostaglandins in sepsis induced by LPS.

Regional blood flow and acid secretion associated with damage and restitution of the gastric surface epithelium in cats

The gastric mucosa of anesthetized cats was exposed to 2 M NaCl for 10 min. After returning to gastric perfusion with 150 mM NaCl and pH 7.40, with and without pentagastrin stimulation, transmucosal potential difference decreased to zero and then gradually increased to approximately half the original value during the following 90 min. H+ secretion decreased and remained close to zero after exposure to 2 M NaCl in nonstimulated cats, whereas pentagastrin-stimulated secretion gradually increased to nearly half the preexposure level. Mucosal blood flow increased, and the vascular resistance decreased in the posterior wall of the stomach corresponding to epithelial damage, as observed by light microscopy after 15 min. Blood flow during pentagastrin stimulation was initially high in fundus and corpus and did not increase further after exposure to 2 M NaCl, but showed similar changes as without pentagastrin in the antrum. Epithelial restitution occurred within 90 min during both nonstimulated conditions and pentagastrin stimulation. In control animals subjected to 150 mM NaCl there were no changes in transmucosal potential difference, H+ secretion, or blood flow throughout the experiment and epithelial damage was not found. In conclusion, damage caused by 2 M NaCl to the gastric surface epithelium was associated with decreased acid secretion and increased mucosal blood flow. These factors may contribute to creating favorable conditions for the epithelial restitution, indicated by restoration of transmucosal potential difference and observed by light microscopy.