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Biomedical subjects

A Ribet

Publications and source records attributed to A Ribet.

At least 109 records · Page 6Linked to original sources
PubMed1980

Effects of pancreatic duct ligation on the hamster intestinal mucosa. Histological findings.

After pancreatic duct ligation good correlations were observed between degenerative signs of the exocrine pancreas and ultrastructural changes of intestinal epithelial cells: hypertrophy of Paneth and goblet cells; hyperplasia of Paneth cells, mucous cells and 'intermediate granular cells' after the 10th day. On the 7th day, the absorbing area of the intestine (villi area and microvilli area) decrease significantly. These cytological changes partially disappear after the 15th day concomitant to a partial regeneration of the exocrine pancreas. These findings suggest correlations between the epithelial cells of the small intestine and exocrine pancreatic secretion. Different possibilities (direct action of the pancreatic juice or indirect mechanisms) are discussed and proposed to explain the morphological variations of the intestinal mucosa after pancreatic duct ligation.

Animals↗
PubMed1980

Screening for colorectal tumors - results of two years experience.

The experience after two years of systematic colorectal tumors screening of 603 subjects, aged between 40 and 70, is reported. All subjects were submitted to proctoscopy (P) and air filled barium enema (AFBE). Total frequency of screened tumors: 15.25%. More than 85% of the tumors were found in the recto-sigmoid. Two subgroups were identified in this population. In subgroup A, 125 subjects were submitted to P, AFBE and flexible pansigmoidoscopy (FP). Percentage of screened tumors is 19.2%. Sensitivity rate of radiology for exploration of the recto-sigmoid area, as compared to FP is rather low: 0.41. In subgroup B, 165 subjects were submitted to hemoccult, P, AFBE and colonoscopy when an abnormal or dubious image was shown by AFBE. The comparative study of these different means of investigation shows a very low rate of sensitivity of hemoccult: 0.16. In addition, the percentage of screened colorectal tumors is significantly higher (p less than 0.01) in subjects with personal or family history of polyp or carcinoma: 22%, compared to the incidence in the remaining population of 13%. Flexible pansigmoidoscopy is recommended for systematic screening of colorectal tumors in subjects older than 40.

Adult↗
PubMed1980

Somatostatin 28: effects on exocrine pancreatic secretion in conscious dogs.

The effect of somatostatin 28, a noval intestinal peptide containing somatostatin in its C-terminal portion, was tested on basal exocrine pancreatic secretion on conscious dogs and after stimulation by secretin (1 CU x kg-1 x hr-1), caerulein (37.5 ng x kg-1 x hr-1) or secretin (2 CU x kg-1 x hr-1) caerulein (37.5 ng x kg-1 x hr-1). We found differences in the inhibitory effect of somatostatin 28 on these three forms of stimulation. Bicarbonate secretion stimulated by secretin was inhibited only slightly by large doses of somatostatin 28, whereas small doses markedly inhibited stimulation by caerulein. Protein concentrations were inhibited only when secretin was the stimulant. Protein outputs to all forms of stimulation were inhibited. When compared with synthetic somatostatin 14, lower doses of somatostatin 28 were required to produce the same inhibitory effect on protein outputs stimulated by secretin alone and on volumes stimulated by caerulein alone.

Animals↗
PubMed1979

A cyto-physiological study of the G-cell secretory cycle in the antrum mucosa of the hamster and of the rat.

The secretory cycle of the antral G cell in the golden hamster and in the Wistar rat has been investigated, using classical techniques of optical and electron microscopy associated with special methods (such as goniometry, densitometry, immunohistology, morphometry) and with radioimmunoassay for gastrin. This paper confirms the secretory cycle of the G cell after refeeding. It clarifies the nature of granule polymorphism and suggests a particular mechanism of emiocytosis with sequential granule fusion. Furthermore, our investigations show some dissociations between the G cell, the parietal cycle, and the seric immunoreactive gastrin in the late phase of the secretory cycle (2 to 6 h after refeeding).

Animals↗
PubMed1979

Comparative effects of CCK-PZ on certain intestinal hydrolases in the mucosa and in the luminal content of the hamster jejuno-ileum.

After isolation of the hamster small intestine, the effects of a continuous infusion of cholecystokinin-pancreozymin (CCK-PZ) are studied. Several enzymic activities are measured in the intestinal lumen and compared with the level found in the intestinal homogenate. During CCK-PZ infusion we observed a direct stimulation of Paneth cells associated with an increase of lysozyme activity. Furthermore this work confirms the stimulating effect of CCK-PZ on alkaline phosphatase and amino-peptidase. Maltase and sucrase levels were unaffected. The liberation of the hydrolase of the brush border in the intestinal lumen is negligible and cannot be considered as a true secretion. Only granule content of Paneth cells is actually secreted. However, biochemical data, corroborated by morphological results, suggest that Paneth cell secretion could in part be absorbed on the outer surface of the brush border.

Alkaline Phosphatase↗
PubMed1978

Biochemical studies of pancreatic juice collected by duodenal aspiration and endoscopic cannulation of the main pancreatic duct.

Biochemical studies of pancreatic juice collected by duodenal aspiration and endoscopic cannulation of the main pancreatic duct were performed and compared in the same fasted normal subjects in seven cases. The comparison of the results shows that under the same stimulation (0.5 CU/kg/hr of GIH secretin and 75 ng/kg/hr of cerulein) the endoscopic cannulation of the main pancreatic duct provides the best values for the maximal secretory capacity. On the other hand, this technique is no better than our current method of duodenal aspiration for the exploration of the enzyme secretion.

Adult↗
PubMed1978

Inhibition of exocrine pancreatic secretion by somatostatin in dogs.

The effect of somatostatin on the pancreatic exocrine response to different doses of exogenous stimuli and the somatostatin dose-response relationships on pancreatic secretion were studied in conscious dogs. Somatostatin caused a strong inhibition of basal or slightly stimulated pancreatic secretion but failed to inhibit the maximal responses, suggesting that somatostatin interacts with secretin or caerulein by a competitive mechanism. A higher maximal percentage of inhibition and a dose-response relationship was observed with protein outputs and enzyme concentrations. Volumes and bicarbonate outputs were also inhibited but the maximal percentage of inhibition was lower.

Animals↗