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Biomedical subjects

W Y Chey

Publications and source records attributed to W Y Chey.

At least 181 records · Page 10Linked to original sources

Electrogastrographic study of patients with unexplained nausea, bloating, and vomiting.

A method of recording gastric myoelectric activity with a peroral suction electrode was evaluated, and the recording was compared with that obtained by implanted electrodes on the serosal surface of the stomach of laparotomized humans. In a group of patients with unexplained nausea, epigastric bloating, and vomiting, abnormal antral myoelectric activities were found by a peroral electrode, in contrast to a regular pacesetter potential (frequency: 3-4/min) in control subjects. These abnormalities were confirmed by the recordings from the implanted electrodes in the same subjects. The study indicates that peroral recording of gastric myoelectric activity is a useful diagnostic method for the detection of gastric myoelectric activity abnormalities in humans.

Action Potentials↗

Influence of the vagus nerve on release and action of secretin in dog.

1. The role of cholinergic nerve on plasma concentration of immunoreactive secretin and pancreatic bicarbonate secretion was investigated in conscious and anaesthetized dogs. 2. In conscious dogs with gastric and pancreatic fistulae, I.V. administration of 2-deoxy-D-glucose (2-DG) potentiated the pancreatic bicarbonate secretion stimulated by duodenal acidification. 3. In conscious dogs with same preparation, I.V. administration of atropine inhibited the pancreatic bicarbonate secretions stimulated by duodenal acidification or exogenous secretin. 4. Neither 2-DG nor atropine had any effect on endogenous release of secretin. 5. In anaesthetized dogs, pancreatic bicarbonate secretion stimulated by duodenal acidification was decreased by bilateral cervical vagotomy. However, plasma secretion concentration achieved by duodenal acidification was not different from that of pre-vagotomy state. 6. The data indicate that the changes of cholinergic tone do not affect release of endogenous secretin but alter the exocrine pancreatic bicarbonate secretion stimulated by secretin.

Animals↗

Plasma secretin concentrations in fasting and postprandial states in dog.

In four dogs with a modified Herrara pancreatic fistula and gastric cannula and three dogs with two duodenal cannulas, ingestion of a meat meal resulted in a significant and sustained increase in the mean plasma immunoreactive secretin concentrations, from mean fasting levels of less than 10 pg/ml to 25--55 pg/ml. This increase in the plasma secretin concentration coincided with a marked increase in pancreatic bicarbonate output and frequent decreases in the mean proximal duodenal pH to less than 4.5 from the range of 6.5 in the fasting state. Intravenous administration of cimetidine, 150 mg, produced a marked suppression of postprandial increases in both pancreatic bicarbonate output and plasma secretin concentration. Moreover, the postprandial duodenal pH rarely reached below 5.0 after cimetidine administration. These studies indicate that plasma secretin concentration does increase significantly after a meal. The postprandial increase in plasma secretin concentration appears to depend on the gastric acid delivered in the proximal duodenum. A possible physiological role of secretin in the pancreatic secretion after a meal is indicated by these findings.

Animals↗

Methyldopa-induced pancreatitis.

An acute febrile illness associated with gastrointestinal upset developed in a patient within one week after starting treatment with methyldopa. The illness was characterized by prompt subsidence of symptoms when the patient withdrew therapy secondary to gastrointestinal upset, and recrudescence of symptoms when methyldopa therapy was reinitiated. This was associated with hyperamylasemia, hyperlipasemia, hyperpyrexia, and epigastric pain, both on admission to the hospital and upon rechallenge with methyldopa. Although gastrointestinal upset has been reported as an untoward side effect of methyldopa, this is the first report to our knowledge of documented methyldopa-induced hyperamylasemia and hyperlipasemia secondary to pancreatitis.

Amylases↗

Impairment of secretin release in celiac sprue.

Plasma secretin concentrations and pH in the second portion of duodenum were measured in the fasting state and during duodenal infusion of HCl in five patients with untreated celiac sprue, five celiac sprue patients after gluten-free diets, and five normal subjects. Mean fasting plasma secretin concentrations were insignificantly lower in untreated sprue patients (4.1 +/- 1.4 pg/ml) than in normal subjects (5.7 +/- 0.59 pg/ml). During 30-min intraduodenal infusions of 0.1 N HCl at 0.20 mEqH+/min, mean plasma secretin concentrations were significantly lower in untreated sprue patients (5.8 +/- 1.8 pg/ml) than in normal subjects (25.4 +/- 1.60 pg/ml, P less than 0.01). The increases in mean secretin concentrations over fasting were 2.1 +/- 0.82 pg/ml in untreated sprue patients compared to 19.7 +/- 1.47 pg/ml in normal subjects (P less than 0.01), a ninefold difference. The results indicate that endogenous release of secretin in response to duodenal acidification is impaired in patients with celiac sprue.

Adult↗

Plasma secretin concentrations in fasting and postprandial state in man.

Plasma immunoreactive secretin concentrations were determined in both healthy subjects and patients with duodenal ulcer. The modified radioimmunoassay method could detect significant increases in the plasma secretin concentrations when 0.05 N HCl was infused intraduodenally at a rate of 1.1 and 2.2 ml/min. The mean fasting plasma secretin concentration of 13 normal healthy subjects was 4.4 +/- 0.38 pg/ml which was significantly less (P less than 0.01) than that of 13 duodenal ulcer patients, 6.9 +/- 0.64 pg/ml. In both groups ingestion of a meat-containing meal resulted in significant increase in the plasma secretin concentrations. Recording of pH from proximal duodenum indicated that pH fell periodically below 4.5 during the postprandial period, indicating that only a short segment of proximal duodenum was exposed to acid after meal. The postprandial rise in plasma secretin levels was abolished when antral pH was raised 5.5 by intragastric infusion of 0.3 N NaHCO3 solution. These observations indicate that although fasting plasma secretin levels are low, the plasma secretin levels increase significantly after ingestion of a meal. This increase appears to be attributable to an increased amount of acid delivered to the proximal duodenum, and patients with duodenal ulcer were found to release more secretin during the postprandial period than normal subjects.

Adult↗

Serial pH changes in the duodenal bulb during smoking.

The effect of smoking on the pH of the duodenal bulb was studied in 10 normosecretors and 10 hypersecretors using a Beckman pH electrode. The pH was monitored during three study periods, basal, smoking, and postsmoking, of 1 hr each. The pH remained below 3.5 significantly longer during the smoking period compared to the basal period for both groups. The bulbar pH remained under 3.5 during the smoking period longer in the hypersecretor group compared to the normosecretor group (60 versus 20%). Hypersecretors who were smokers exhibited acidic bulbar pH values longer and more consistently than hypersecretor-nonsmokers during smoking. In 5 hypersecretors with data for both bulbar pH and bicarbonate output, inhibition of bicarbonate output during smoking was generally associated with acidic pH values in the bulb. These observations suggest that the association between cigarette smoking and peptic ulcer disease may be attributable to, in part, the persistently acidic pH values in the duodenal bulb during smoking. This study further suggests that the degree and the duration of acidification of the duodenal bulb during smoking are influenced by the secretory and the smoking status of the subject.

Adult↗