Osvaldo Llanos

Accuracy of the first endoscopic procedure in the differential diagnosis of gastric lesions.

The accuracy of endoscopy and directed biopsy in the differential diagnosis of gastric lesions was evaluated by comparing the diagnoses of one endoscopic procedure (endoscopy and multiple directed biopsies) with the definitive diagnoses in 333 patients. The overall endoscopic and bioptic accuracy rate for all patients amounted to 98.8%. Separate accuracy rates of endoscopy alone and biopsy were 86.5% and 94.9%, respectively. The reliability of endoscopy was similar in the diagnosis of malignant and benign lesions (86% and 89%). Endoscopic biopsy was correct in 99.1+ of benign lesions and in 86% of malignancies. False negative rates were 3.9% for endoscopy and 4.0% for biopsy. It is concluded that one endoscopic procedure is a highly reliable method in the differential diagnosis of benign and malignant gastric lesions.

The effect of fat on secretin release.

The effect of graded doses of intravenously infused secretin and intestinally perfused sodium oleate and HCI on pancreatic exocrine secretion and plasma secretin was determined in cats and dogs prepared with pancreatic fistulas. The pancreatic dose-response curves for bicarbonate following duodenal perfusion of oleate and HCI in cats were almost identical and paralleled the response to exogenous secretin. Although the bicarbonate response to oleate in dogs was less pronounced than the response to HCI or secretin, the bicarbonate output was observed to increase relative to protein output with increasing doses of the intestinally perfused fat. These observations suggested that secretin or a substance with secretin-like activity may be released from the intestine on contact with fat. The inability to detect changes in secretin immunoreactivity in both cats and dogs with increasing doses of oleate suggests that if secretin is released, it is in amounts undetectable by our radioimmunoassay or that some other unknown substance with secretin-like activity may be released.

Results of Surgical Treatment of Gastric Cancer

Background/Aim: The extent of gastric resection and the role of lymphadenectomy in the treatment of gastric cancer are controversial. Methods: This study evaluates the results of radical gastric resection (D2 lymphadenectomy) in 375 patients with a gastric carcinoma operated according to a prospective protocol. Results: Total gastrectomy was performed in 196 and a subtotal gastrectomy in 179 patients, with an operative mortality of 3.5 and 2.8%. The presence of lymph node metastasis was related to the depth of the tumor in the gastric wall. The cumulative 5-year survival was dependent on the depth of tumoral invasion in the gastric wall and also on the presence of lymphatic metastasis. Curative resection had a significantly better 5-year survival (72%) than noncurative resection (26%). Conclusion: Although it is difficult to prove the benefits of extended lymphadenectomy in the surgical treatment of gastric carcinoma, the results of these series seem to support its usefulness.

Release of antral and duodenal gastrin in response to an intestinal meal.

AbstractIn dogs prepared with isolated, innervated antral pouches, intraduodenal perfusion with liver extract at pH 7, with the atrum buffered at pH 7, resulted in a significant release of gastrin selectively from the antrum and from the duodenum. Acidification of the meal to pH 1 abolished both antral and duodenal gastrin release, whereas acidification of the antrum abolished only the antral gastrin response. After antrectomy, liver extract at pH 7 caused a diminished but significant release of duodenal gastrin. These studies provide evidence that an intestinal meal may release (in addition to a specific intestinal phase hormone) gastrin from the intestine, and from antrum, by means of a pH-sensitive mechanism which may involve a humoral agent (enterobombesin?) from the small bowel.

Secretin, Gastrin and Pancreatic Bicarbonate Responses to Meals Varying in pH Levels

Release of endogenous secretin by duodenal acidification has been shown to occur in man and other species. Ingestion of food has, however, resulted in no consistently detectable increase in plasma secretin levels measured by radioimmunoassay. This study was designed to test the effect of the acidification of a meal on secretin and gastrin levels and on pancreatic bicarbonate and gastric acid secretion.