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Biomedical subjects

W Y Chey

Publications and source records attributed to W Y Chey.

At least 199 records · Page 11Linked to original sources
PubMed1977

Effect of motilin on the lower esophageal sphincter of the opossum.

We have studied the effect of Yajima's synthetic motilin on the lower esophageal sphincter (LES) of the opossum and compared its potency to that of gastrin and its interaction with secretin. Dose-response curves for the LES were constructed from the intravenous bolus injection of graded doses of motilin and gastrin alone and motilin given against a background infusion of secretin. The smallest dose of motilin that elicited a significant response was 0.05 microng/kg, and the highest response was observed with the highest dose used in this study (1.0 microng/kg). Over a wide dose range, both motilin and gastrin were found to be equally potent in stimulating the LES of the opposum, and secretin caused inhibition of the LES pressure to motilin. Therefore, we conclude that (1) motilin is a potent stimulant of the LES; (2) this response is dose dependent; (3) motilin's potency is similar to that of gastrin; and (4) secretin counteracts the effect of motilin on the LES.

Animals↗
PubMed1977

Hemangioendotheliomatosis of the liver. A 12-year follow-up.

Hemangioendothelioma of the liver is a rare tumor. A case is reported of a middle-aged woman who presented with hepatomegaly and ascites, and who has been followed for over 12 years. The clinical features, pathological, radiographic, portal hemodynamic, and metabolic changes are presented.

Adult↗
PubMed1977

Pathophysiology and significance of malabsorption after Roux-en-Y reconstruction.

Extensive metabolic studies were conducted in five normal controls and in five study patients after total gastric resection with Roux-en-Y (RY) reconstruction to determine the nutritional consequences of this particular technique of restoring gastrointestinal continuity. Although malabsorption of fat (19.2 +/- 2.2%) and nitrogen (22 +/- 2.5%) demonstrated in the study patients was moderate, it was significantly greater than normal ( less than 0.01). In spite of the demonstrated malabsorption, however, positive nitrogen balances (+ 0.33 +/- 0.18 gm/day) were maintained in the RY patients throughout the investigative period. These observations suggest that malabsorption after RY is infrequently of clinical significance, even in this "worst-case" situation characterized by complete removal of gastric tissue. Malnutrition should occur in only those patients with more limited gastric resections and RY reconstruction who are unable to increase caloric intake to cover losses due to malabsorption. A significant decrease in both trypsin and lipase concentrations and a marked delay in secretion of these enzymes was noted in the RY patients in response to a test meal (p less than 0.01). Malabsorption of fat and nitrogen in RY patients improved after exogenous pancreatic enzymes, but not after administration of tetracycline. Bacterial overgrowth as a cause of postoperative malabsorption may be less important than previously thought. Malabsorption after RY is due primarily to maldigestion brought about by duodenal bypass which, in turn, results in either an absolute or a relative pancreatic enzyme insufficiency.

Bile Acids and Salts↗
PubMed1977

Simultaneous measurement of basal pancreatic, gastric acid secretion, plasma gastrin, and secretin during smoking.

The effect of smoking one unfiltered cigarette every 15 min for 1 hr on basal gastric acid and pancreatic secretion was studied in 10 subjects with a history of duodenal ulcer and 10 without duodenal ulcer. Smoking induced a transient rise of basal acid output followed by a slight decrease. This effect was more pronounced in the duodenal ulcer group. Smoking markedly inhibited fluid and bicarbonate secretion during the smoking period. The bicarbonate and fluid secretion returned to control levels within 30 to 60 min in the ulcer group and in 60 to 90 min in the nonulcer group. There was no difference in the degree of inhibition of pancreatic secretion between the two groups. Immunoreactive gastrin and secretin in the peripheral venous blood did not change significantly during smoking. The degree of inhibition of basal pancreatic secretion correlated well with the plasma concentrations of nicotine. These observations indicate that smoking in the fasting state induces alterations of basal gastric and pancreatic secretions which are not related to changes in plasma gastrin and secretin concentration, but to plasma concentrations of nicotine. The implication of this study in relation to a possible causal association between cigarette smoking and peptic ulcer disease is discussed.

Adult↗
PubMed1976

Observations of plasma secretin levels by radioimmunoassay in response to duodenal acidification and to a meat meal in humans.

The endogenous release of secretin in healthy human subjects was studied by measuring plasma secretin levels by radioimmunoassay (RIA) before, during, and following duodenal acidification and eating a meal. The sensitivity of our RIA was assessed by measuring plasma secretin levels during constant intravenous infusions of 4 graded doses of secretin. Our RIA detected significant increases (P less than 0.001) in plasma secretin with each dose, including a low dose of 0.125 U (41.3 ng)/kg hr. Intraduodenal infusion of 0.1 N HCl resulted in marked increases (P less than 0.001) in plasma secretin levels whenever pH in the second portion of the duodenum was reduced to less than 3.5. In contrast, following a meal, pH in the second portion of the duodenum remained consistently greater than 4.5 and plasma secretin levels showed no changes from basal levels. These studies confirm that endogenous release of secretin depends on an acidic pH of the duodenum, and insigificant changes in the plasma secretin level following ingestion of a meal suggest that endogenous release of secretin in the postprandial period is probably to small in quantity to be detected by the present radioimmunoassay method.

Adolescent↗
PubMed1976

Plasma secretin and gastrin responses to a meat meal and duodenal acidification in dogs.

In five conscious dogs with gastric fistula and two duodenal cannulas, plasma RIA secretin and gastrin levels were determined in response to 1) infusion of 0.1 N HCl in the proximal duodenal cannula, 2) ingestion of a meal, and 3) intraduodenal infusion of 0.1 N HCl following ingestion of a meal. Significant increases in plasma RIA secretin levels occurred during duodenal acidification. However, no significant change occurred in the secretin levels after ingestion of a meal, whereas significant increase in plasma gastrin level was observed. Postprandial duodenal pH remained above 4.5 for 3 h.

Animals↗
PubMed1976

Secretion cells in the gastrointestinal tract.

The morphology and distribution of secretin (S) cells were investigated in the human and the dog. S cells were well-visualized by the indired immunofluorescence antibody technique, using a highly specific rabbit anti-secretin sera. The fluorescence reaction was not blocked by an excess amount of gastrin, cholecystokinin, glucagon, vasoactive intestinal polypeptide, or motilin, whereas secretin blocked the reaction. S cells were seen in the mucosa of the antrum and duodenum in both humans and dogs, and throughout the entire length of the canine small intestine. They were not found in the mucosa of the esophagus, fundus of the stomach, or rectum. These cells were either pyramidal in shape or pearshaped and were one-third of the size of gastrin cells. The possible significance of S-cell distribution in the antrum and small intestine is discussed.

Adult↗
PubMed1975

Watery diarrhea associated with pancreatic islet cell carcinoma.

A patient with severe watery diarrhea and a non-beta islet cell carcinoma of the pancreas producing five hormones (secretin, serotonin, enteroglucagon, vasoactive intestinal polypeptide, and pancreatic glucagon) is described. We have demonstrated massive pancreatic hypersecretion to be a major factor in this patient's diarrhea. Possible inter-relationships of the actions of five hormones present in excess in the patient are discussed.

Adenoma, Islet Cell↗