CEH-EUS with the new Olympus prototype device successfully visualizes the microvascular pattern in pancreatic solid lesions, and may be useful for distinguishing adenocarcinomas from other pancreatic masses.

The postprandial release of immunoreactive insulin, glucagon, gastrin, somatostatin, pancreatic polypeptide (PP), and gastric inhibitory polypeptide (GIP) was studied in parallel with the absorption of sugars and amino acids in conscious pigs. Six pigs fitted with permanent catheters in the portal vein and arterial blood system as well as within an electromagnetic flow probe around the portal vein received successively at 3-day intervals, three meals of 800 g each containing 0, 14, or 28% protein (semisynthetic diets based on fish protein). Blood samples were collected and portal blood flow was recorded during a postprandial period of 8 h. For the same level of feed intake, an increase in the dietary protein concentration led to a higher alpha-amino nitrogen absorption and to a lower appearance of reducing sugars in the portal vein; in addition, the carbohydrate absorption efficiency (amounts absorbed as a percentage of amounts ingested) was reduced, showing the competition between the absorption of amino acids and glucose. The largest absorption occurred during the first 4 h after the meal, but neither the digestion of proteins nor that of carbohydrates were finished 8 h after the meal since portoarterial differences could still be observed. All test meals induced a rise of portal and peripheral concentrations of insulin, gastrin, somatostatin, and PP, and of the systemic level of GIP. Glucagon increased after the 28% protein meal only. The rise of plasma insulin paralleled that of blood glucose, and bore a significant positive relationship to the systemic GIP level in the early postprandial period. In terms of absolute amounts, portoarterial concentration gradients increased postprandially. Insulin release was significantly the highest after intake of the 14% protein diet. The gastrin response was significantly correlated to the amount of protein. Similarly the release of glucagon and somatostatin tended to increase with increasing dietary amount, but differences failed to reach significance (P less than 0.05), except for glucagon 2 h after the meal. There were very close relationships between the hourly amounts of alpha-amino nitrogen absorbed and gastrin and glucagon production, as between insulin and PP secretions. From the present results, the induction of physiological increments of plasma peptide concentration in 60-kg pigs would require infusion rates of about 50-250 micrograms/h for insulin, 1-4 micrograms/h for gastrin 17, 5-10 micrograms/h for glucagon and somatostatin, and 5-50 micrograms/h for PP.

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The effect of three concentrations of high-methoxy apple pectin (5, 10, and 15 g), on solid-liquid meal digestion was studied in 12 healthy men by the gastrointestinal intubation technique. The gastric emptying of water and carbohydrates is significantly reduced only after 10 and 15 g pectin. The changes in gastric pH are similar for pectin-free and pectin-containing meals. Cumulative lipase and trypsin outputs are not significantly different with and without pectin. When gastric uronic acid concentration is above 6 g/l, the duodenal absorption of carbohydrates is significantly reduced (p less than 0.001). The mean blood glucose levels with 10 and 15 g pectin are significantly higher than the control values at 180 min (p less than 0.05). Pectin does not modify serum concentrations of secretin, cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), and somatostatin but serum motilin and gastrin levels are below the control values after high fiber meal.

SUMMARY The aim of this study was to measure the role of the duodenal loop in biliopancreatic secretion in man by infusing various stimuli at the ampulla of Vater and collecting duodenal contents at the ligament of Treitz, above an occluding balloon. Perfusion at 10 mVmin of a first mixture of aminoacids -phenylalanine (47.2 mmol), methionine (38.2 mmol), tryptophan (11 mmol), valine (61-6 mmol) -increased cholecystokinin (CCK) plasma concentrations and duodenal bile salt output (p