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Biomedical subjects

J I Isenberg

Publications and source records attributed to J I Isenberg.

At least 109 records · Page 6Linked to original sources

Effect of intravenous lipid on gastric acid secretion stimulated by intravenous amino acids.

Intraduodenal fat is a potent inhibitor of all forms of gastric acid secretion in humans. Studies were performed in random order on 3 separate days in 5 normal subjects to determine if intravenous fat (Intralipid) altered gastric acid secretion stimulated by intravenous amino acids in humans. Mean (+/- SE) gastric acid output during a 4-hr intravenous amino acid infusion (21 g L-amino acids; Freamine II) plus glucose (50 g. to maintain isocaloric and isoosmolar solutions) was 43.2 +/- 3.2 meq/4 hr. Intraduodenal fat fusion (20 g of Intralipid) significantly (P < 0.02) suppressed amino acid-stimulated acid output. Interestingly, intravenous fat (20 g of Intralipid) also significantly (P < 0.02) inhibited acid secretion (14.8 +/- 6.3 meq/4 hr); similar to the effect observed with intraduodenal fat (12.7 +/- 4.9 meq/4 hr). Serum levels of CCK, gastrin, and GIP were measured at 30-min intervals throughout each study. Cholecystokinin and GIP increased significantly from basal during intraduodenal fat infusion. There were no other changes in serum CCK, gastrin, or GIP during any of the other tests. It is concluded that in normal subjects intravenous fat is a potent inhibitor of intraveous amino acid-stimulated gastric acid secretion, similar in effect to intraduodenal fat. The inhibitory effect of intravenous fat on amino acid-stimulated gastric acid secretion is probably not mediated by release of either CCK of GIP. Circulating fat may play a role in the control of some forms of gastric acid secretion.

Adult↗

Cimetidine versus intensive antacid therapy for duodenal ulcer: a multicenter trial.

In a randomized double blind multicenter trial, patients treated with cimetidine (800 or 1200 mg daily) or an intensive regimen of Al-Mg antacid (210 ml daily) had similar rates of duodenal ulcer healing and pain relief. After 4 weeks of treatment, the proportion of patients with ulcer healing by endoscopy were: cimetidine (1200 mg), 21 of 33 (64 percent); cimetidine (800 mg), 19 of 32 (59 percent); and antacids, 15 of 29 (52 percent). These proportions did not differ significantly. Eighty per cent of cimetidine-treated patients became asymptomatic by week 4, as did 63 percent of antacid-treated patients (P greater than 0.1). No untoward effects were observed during cimetidine treatment. Twenty-seven per cent of antacid-treated patients reported diarrhea.

Adult↗

Effect of one-month treatment with cimetidine on gastric secretion and serum gastrin and pepsinogen levels.

The inhibitory effects of cimetidine on gastric acid and pepsin secretion were studied before and after 1 month of treatment with 300 mg of cimetidine four times a day in 15 male duodenal ulcer patients. Cimetidine inhibited both pentagastrin- and peptone meal-stimulated acid secretion significantly better before, than after, 1 month of treatment. Similarly cimetidine inhibited pentagastrin-stimulated pepsin secretion significantly better before treatment. Meal-stimulated serum gastrin concentrations were significantly higher after treatment. The mechanism(s) of these effects was not apparent.

Cimetidine↗

Healing of duodenal ulcer with an antacid regimen.

To determine whether a large-dose antacid regimen is effective in promoting healing of duodenal ulcer, 74 patients with endoscopically proved duodenal ulcer completed a 28-day double-blind clinical trial comparing such a regimen with an inert placebo. The ulcer healed completely in 28 of the 36 antacid-treated as compared to 17 of the 38 placebo-treated patients (P less than 0.005). The antacid regimen was not more effective than placebo in relieving ulcer symptoms. Presence or absence of symptoms during the fourth treatment week was a poor predictor of presence or absence of an ulcer crater. Ulcers of placebo-treated patients who smoked cigarettes were less likely to heal than those of nonsmokers (P = 0.03). Except for mild diarrhea, no side effects of the antacid regimen were observed. We conclude that a large-dose antacid regimen hastens the healing of duodenal ulcer.

Administration, Oral↗

Hypertrophic protein-losing gastropathy and vitiligo. Report of a second case.

A second patient with hypertrophic protein-losing gastropathy and extensive vitiligo was studied. Upper gastrointestinal radiographs and endoscopy revealed multiple polyps of the upper half of the stomach. The patient was achlorhydric to pentagastrin stimulation. Clearance of 51Cr-labeled protein by the gastrointestinal tract was about 15 times normal. A total gastrectomy was done for relief of persistent epigastric pain and correction of hypoproteinemia. Histologically the polyps consisted of hypertrophied mucosal glands with cystic dilatation deep to the glandular layer. The similarity of this patient to a patient previously seen at our hospital led us to report the possible association of hypertrophic protein-losing gastropathy with vitiligo.

Gastric Juice↗

Antacid and placebo produced similar pain relief in duodenal ulcer patients.

The effectiveness of antacid and placebo in relieving single episodes of spontaneous duodenal ulcer pain were compared in two double blind, controlled, randomized trials. The trials compared the effects on ulcer pain of individual doses of a liquid antacid and placebo, rather than the effects of therapeutic regimens with antacid or placebo. Thirty patients were studied. There were no significant differences between antacid and placebo in time to onset, degree, or duration of pain relief. These results suggest that factors other than gastric acid neutralization are important in acute relief of spontaneous duodenal ulcer pain.

Adult↗

Effect of graded amounts of acid instilled into the duodenum on pancreatic bicarbonate secretion and plasma secretin in duodenal ulcer patients and normal subjects.

Pancreatic bicarbonate secretion and plasma secretin were measured in response to graded amounts of hydrochloric acid (0.94, 1.88, 3.75, and 7.5 mEq per 5 min) instilled directly into the duodenum in duodenal ulcer patients and in normal subjects. These graded amounts of acid produced graded increases in pancreatic bicarbonate in both groups. Mean bicarbonate secretion was significantly greater in the duodenal ulcer patients than in the normal subjects basally and after the lowest dose of hydrochloric acid. Mean (+/- SE) peak 30-min bicarbonate output (in milliequivalents) after duodenal acidification was 3.0 +/- 1.0 in the duodenal ulcer patients and 2.1 +/- 0.6 in the normal subjects (P less than 0.5). A significant (P less than 0.05) increase in plasma secretin occurred after duodenal acidification, but the increase in the duodenal ulcer and normal subjects was not significantly different (P less than 0.2). These results indicate that pancreatic bicarbonate secretion and increase in plasma secretin in response to graded amounts of duodenal acid are at least as great in patients with duodenal ulcer as in normal subjects.

Adult↗

Experience with synthetic secretin in the treatment of duodenal ulcer.

Hospitalized male patients with endoscopically verified duodenal ulcer were studied to determine the effect of secretin on the clinical course of their disease. Seven patients received synthetic porcine secretin, 333 mug subcutaneously every 4 hr for 10 days, and 6 patients received placebo injections on the same schedule. Repeat endoscopy was performed within 48 hr of completing the 10-day treatment period. The trial was discontinued because of transient, asymptomatic, hyperamylasemia in secretin-treated patients. Although significant gastric alkalinization could be reproducibly demonstrated in secretin-treated patients, secretin was not more effective than placebo in relieving pain or healing duodenal ulcer. However, because the number of patients was small, definitive conclusions regarding efficacy of secretin in ulcer treatment could not be drawn.

Adult↗

Clearance and acid-stimulating action of human big and little gastrins in duodenal ulcer subjects.

Acid-stimulating action and clearance of pure natural human big gastriin (HG-34-I) and little gastrin (HG-17-I) were assessed in four male subjects with inactive duodenal ulcer (DU) disease. Disappearance half-times for HG-17-I after intravenous infusion (5.2 min) or rapid intravenous injection (6.4 min) were six to eight times shorter than those for HG-34-I (41.5 and 37.8 min, respectively). Studies of clearance of synthetic human little gastrin (HG-17-I) were performed in three of these same four DU subjects, eight additional male DU subjects, and eleven normal male subjects. The disappearance halftime of synthetic HG-17-I averaged 6.2 min in both the DU subjects and the normal subjects. These data suggest that clearance of exogenous gastrin is not altered in patients with DU. Acid secretion in response to rapid intravenous injection of HG-34-I reached a higher peak and lasted longer than in response to an equimolar dose of HG-17-I; the total response to HG-34-I was about three times that to HG-17-I. During constant intravenous infusion, acid responses to equimolar exogenous doses of the two peptides were similar but the increment in molar concentration of circulating gastrin was six to eight times greater with HG-34-I than with HG-17-I. Chromatography of serum obtained during infusions of HG-34-I revealed no evidence of conversion to HG-17-I, nor was there any increase in circulating G-34 activity during infusions of HG-17-I. The increment in serum gastrin concentration required to produce half-maximal stimulation of gastric acid secretion (D50) was estimated in each subject for each gastrin from curves relating acid secretion to change in serum gastrin concentration produced by infusion of these peptides. After instilling peptone solution into the stomach, acid secretion was measured by intragastric titration, and increases in circulating G-17 and G-34 were determined by chromatography and radioimmunoassay of serum. Increases in circulating G-17 and G-34 in response to the peptone meal, taken together, were equivalent to 1.5 times the D50 determined from infusions of G-34 and G-17. Acid secretion during the same time period averaged 55% of maximal rates. Although G-34 comprised approximately three-fourths of the total molar concentration of circulating gastrin after stimulation, it was estimated to contribute less than half of the acid-stimulating activity.

Dose-Response Relationship, Drug↗

A new look at peptic ulcer.

There have been notable advances in knowledge about peptic ulcer recently. Gastrin-producing tumors have been recognized as a rare cause of ulcer, and multiple physiologic defects have been found in duodenal ulcer, including excessive release of gastrin after food intake, increased sensitivity to gastrin, and decreased inhibition by low pH. The tendency of gastric ulcer patients to reflux duodenal contents into the stomach may have pathogenetic significance. Two new classes of drugs strongly inhibit acid secretion in man: chemically modified prostaglandins and histamine analogues which block the action of histamine on acid secretion. Their value in treating ulcer is now being assessed in clinical trials. A new operation for duodenal ulcer shows promise: only those vagal fibers innervating the acid-secreting part of the stomach are severed, thus obviating the need for a drainage procedure and decreasing some of the undersirable side effects of earlier operations.

Antacids↗