Gilbert O. Barbezat

Fibreoptic endoscopy and the use of the Sengstaken tube in acute gastrointestinal haemorrhage in patients with portal hypertension and varices.

The value of emergency upper gastrointestinal fibre-endoscopy, followed where required by the use of a modified Sengstaken tube, was studied during 84 episodes of acute bleeding in 75 patients who had evidence of portal hypertension with varices. The portal hypertension was due to alcoholic cirrhosis in 80% and to cryptogenic cirrhosis in 9% of the patients. By definition, varices were present in all patients, but in only 66% of episodes were the varices the cause of the bleed. The correct diagnosis of the source of bleeding was made at endoscopy in 89%. A Boyce modification of the Sengstaken-Blakemore tube was passed in 73% of the episodes of variceal bleeding. It effectively stopped the bleeding primarily in 85% of patients but was successful as a final definitive measure only in 46%. Furthermore, only 40% of the patients in whom the tube was passed, survived. Mortality rate could be related to the severity of the bleed and to hepatocellular dysfunction. Survival increased from 23% in those patients with jaundice, ascites, and encephalopathy on admission to 92% in those without these manifestations. The in-hospital survival rate was 52% in patients bleeding from varices and 64% in those bleeding from other causes, with an overall survival rate of 56%, indicating the poor prognosis in cirrhotic patients with gastrointestinal bleeding, irrespective of the cause.

Effect of Calcitonin on the Serum Amylase Levels after Endoscopic Retrograde Cholangiopancreatography

Calcitonin or placebo was infused in a double-blind study in 30 patients undergoing endoscopic retrograde cholangiopancreatography. Calcitonin was found to have no significant effect on the hyperamylasemia following this procedure.

The Effect of Gastric Inhibitory Polypeptide on Human Jejunal Water and Electrolyte Transport

Using a triple-lumen gut perfusion technique, the net flux of water and electrolytes in the jejunum of 5 healthy volunteers was measured before, during and after an intravenous infusion of gastric inhibitory polypeptide (GIP). The dose of GIP used (1 mug/min for 30 mins) has previously been shown to raise serum GIP levels to physiological levels achieved in normal subjects after a meal. During GIP infusion, net water Na, K, and HCO3 absorption was significantly reduced and chloride flux was switched from absorption to secretion when compared to pre- and post-GIP control periods (p less than 0.001).

Healing dynamics of traumatic gastric mucosal defects in the normal and hyperacid stomach.

Previous studies in man and preliminary experiments in the pig suggested an exponential healing rate for both gastric ulcers and induced mucosal defects. This was further investigated in six pigs with histamine-induced hyperacidity and in six controls. Healing of simple surgical defects measuring ∼1.5 cm was endoscopically monitored at 2- to 3-day intervals through a Thomas cannula. In the control animals the healing rate was not strictly exponential but conformed to an organic decay curve with maximum healing phase around the fifth day and a slow initial and late healing velocity. In the six histamine-treated animals the healing rate was significantly delayed (P<0.02) in the first four days but thereafter resembled that of the control animals. This suggests that acid secretion may be a determinant factor, especially within the early healing phase.

Secretion of neurotensin and its effects on the jejunum in the dog.

The triple-lumen perfusion technique was used to assess the effect of neurotensin on the canine jejunum; net water and electrolyte fluxes were measured during intravenous infusion of neurotensin and during preceding and succeeding control infusions of sodium chloride. A pharmacologic dose of neurotensin (70 pmol X kg-1 X min-1) converted basal net jejunal water and electrolyte absorption to net secretion (p less than 0.02); 3.2 pmol X kg-1 X min-1 of the peptide significantly inhibited net water and electrolyte absorption (p less than 0.05), and induced a transient but consistent increase in jejunal transmural potential difference; however, 1.3 pmol X kg-1 X min-1 had no significant effect on net jejunal water and electrolyte fluxes. Neurotensin (1.3 pmol X kg-1 X min-1) induced a rise in plasma neurotensinlike immunoreactivity which was greater than the increment occurring after a normal meal, but which could be reproduced in the same animals by infusion of oleic acid into the ileum. This latter stimulus, however, had no effect on jejunal potential difference, or net water and electrolyte fluxes. These observations do not support a hormonal role for neurotensin in the postprandial regulation of intestinal function in the dog, although they do not rule out the possibility of physiologic paracrine activity.

Jejunal secretion in response to a duodenal mixed nutrient perfusion.

A multilumen balloon tube constructed to separate duodenal and jejunal perfusion segments was placed in the proximal small bowel of 6 healthy volunteers. The effect of nutrient mixture in the duodenum on net jejunal water and electrolyte flux was then determined. The duodenum was perfused with a balanced electrolyte solution before and after the nutrient perfusion. Net water flux in the perfused jejunum changed from absorption 27.0 +/- 6.0 microliter/min/cm, (mean +/- SEM) to secretion 7.7 +/- 7.3 microliter/min/cm (P less than 0.025) during nutrient perfusion. There was also net chloride secretion and decreased net absorption of Na, K, and HCO3 (P less than 0.05). The jejunal absorption of water and electrolytes before and after the duodenal nutrient perfusion was the same. Results indicate that intestinal secretion may occur under physiologic conditions at sites remote to the application of food in humans.

Glucagon inhibition of secretin and combined secretin and cholecystokinin stimulated pancreatic exocrine secretion in health and disease.

The effect of glucagon infusion on secretin and combined secretin and cholecystokinin stimulated exocrine pancreatic secretion was studied in normal subjects and in patients after acute and with chronic pancreatic disease. Glucagon inhibited pancreatic protein secretion and had no inhibitory effect on volume or bicarbonate secretion.

Serum Gastrin Levels Before and After 6 Weeks of Cimetidine Therapy in Patients with Duodenal Ulcer

Fasting serum gastrins were carried out at the beginning and end of a 6-week double-blind trial of cimetidine and placebo in 30 patients with duodenal ulcer. Cimetidine did not cause any significant change in fasting serum gastrin levels after 6 weeks of therapy.

The effect of histamine H2-receptor blockade with metiamide on serum gastrin levels in man.

Metiamide, an histamine H2-receptor antagonist which inhibits gastric acid secretion, does not lower basal serum gastrin concentration in man. Serum gastrin responses after stimulation by food were marginally higher when the stimulus of food was preceded by metiamide.

Kinetics of somatostatin inhibition of pentagastrin-stimulated gastric acid secretion

Dogs with gastric fistulae and denervated gastric pouches received graded doses of pentagastrin with and without a background infusion of somatostatin (1 microgram kg-1 h-1). Similarly, graded doses of somatostatin (0.25, 0.5, 1, 2 and 4 microgram kg-1 h-1) were infused after a steady state gastric secretion had been achieved with pentagastrin (1.5 microgram kg-1 h-1), about twice the dose required to produce half maximal (D50) response. Somatostatin inhibited pentagastrin-stimulated gastric acid secretion with competitive inhibition kinetics, but its precise site of action remains uncertain. The minimum effective dose of somatostatin on a twice D50 dose of pentagastrin was 0.25 microgram kg-1 h-1.