Oral cavity as a potential source of gastric reinfection by Helicobacter pylori.

Helicobacter pylori (Hp) is a common pathogen colonizing the a gastric mucosa, but some reports indicated that it may also be found in the oral cavity, which could serve as a reservoir of the bacteria and a source of gastric reinfection. Accordingly, we aimed to study whether the oral cavity, particularly gingival pockets, are colonized by Hp and whether it could be the source of gastric reinfection. We studied 329 patients with dyspeptic symptoms (257 with chronic gastritis, 15 with gastric ulcer, and 57 with duodenal ulcer).

Luminal Nalpha-methyl histamine stimulates gastric acid secretion in duodenal ulcer patients via releasing gastrin.

Nalpha-methyl histamine is an unusual histamine metabolite which is produced in the stomach infected by Helicobacter pylori and which was shown in animals to stimulate gastric acid secretion and to release gastrin in vitro isolated G-cells, but no information is available regarding its influence on gastric secretion and gastrin release in duodenal ulcer patients before and after H. pylori eradication. In this study, we compared the effects of intragastric administration of single or graded doses of Nalpha-methyl histamine on gastric acid secretion and plasma gastrin levels in 16 male duodenal ulcer patients (aging from 35 to 48 years and weighing 65-82 kg) before and after the eradication of H.

Helicobacter pylori and impaired gastric secretory functions associated with duodenal ulcer and atrophic gastritis.

Previous study showed that duodenal ulcer (DU) patients infected with Helicobacter pylori (H. pylori) have increased basal and pentagastrin- or GRP-induced gastric acid secretion and that these disturbances reversed fully after eradication of H. pylori.

Effects of ebrotidine on aspirin-induced gastric mucosal damage and blood flow in humans.

Nonsteroidal anti-inflammatory agents (NSAIDs) such as aspirin (ASA) damage the gastric mucosa both in normal subjects and in arthritic patients. The aim of this study was to investigate the protective action of a new H2-receptor antagonist, ebrotidine, in the prevention of ASA-induced acute mucosal injury in the stomach of healthy volunteers. In a double-blind randomized crossover study 10 male volunteers received treatment with either placebo plus ASA (500 mg) or ebrotidine (800 mg) plus ASA twice daily for 3 days with 10 days' washout period between treatments.

Gastric acid inhibitory profile of ebrotidine, a novel H2-receptor antagonist in humans.

This study was designed to assess the gastric secretory effects of ebrotidine, a novel H2 receptor antagonist, in humans. Three groups (A, B and C) of male subjects with normal gastric mucosa were used. Group A (6 subjects) was used to determine the dose-dependency of gastric inhibitory effect of ebrotidine on basal and pentagastrin-induced maximal acid output.

Effects of nocloprost on gastric functions in man.

Previous studies in animals and humans demonstrated that nocloprost, a stable prostaglandin E2 analogue, shows very high gastroprotective potency, relatively weak gastric inhibitory activity, and low systemic bioavailability after oral administration. In this study the effects of nocloprost on gastric acid secretion and intraluminal pH and on gastric emptying and plasma gastrin levels were determined in humans. Nocloprost at doses of 50 and 100 micrograms was ineffective, but at a dose of 200 micrograms it reduced the response to pentagastrin significantly and that to a peptone meal by 30-50% and abolished plasma gastrin response without affecting the rate of gastric emptying.

Cholecystokinin in the inhibition of gastric secretion and gastric emptying in humans.

Cholecystokinin (CCK) is known to inhibit gastric acid secretion and gastric emptying but its physiological role in the inhibition of gastric functions is not settled. In this study performed on 16 young male subjects, gastric acid secretion and emptying rate were determined after intragastric administration of 8% peptone meal alone or in combination with intravenous infusion of graded doses of CCK-8 (5-80 pmol/kg.h) or with addition of vegetable oil to meal without or with pretreatment with loxiglumide, a specific CCK antagonist.

Effects of colloidal bismuth subcitrate on aspirin-induced gastric microbleeding, DNA loss, and prostaglandin formation in humans.

Ten healthy young male subjects took part in a double-blind, placebo-controlled, crossover trial to assess the effect of colloidal bismuth subcitrate (De-No) on prostaglandin (PG) E2 generation and mucosal integrity in an aspirin (ASA)-treated stomach. After administration of ASA (2.5 g) plus placebo, a marked reduction in mucosal generation of PGE2 (by about 85%) was observed, and this was accompanied by a significant increase in gastric microbleeding and DNA loss and endoscopic and histologic damage of the mucosa.

De-Nol stimulates gastric and duodenal alkaline secretion through prostaglandin dependent mechanism.

This study was designed to determine the effects of colloidal bismuth subcitrate De-Nol on gastric HCO3- secretion in 24 healthy subjects and on gastric and duodenal HCO3- secretion in dogs with gastric and duodenal fistulae. Alkaline secretion was measured after pretreatment with ranitidine to abolish the H+ secretion using a constant perfusion aspiration system and back titration of the perfusates to the original pH 6.0.

Effects of protective drugs on gastric alkaline secretion in man.

This study was designed to determine the effects of sucralfate, De-Nol, and Maalox 70 on gastric HCO3 secretion in 34 healthy humans. Alkaline secretion was measured after pretreatment with ranitidine to abolish H+ secretion, using a constant perfusion-aspiration system and back-titration of the perfusates to the original pH 6.0.

Vagal cholinergic control of gastric alkaline secretion in normal subjects and duodenal ulcer patients.

Gastric alkaline secretion was determined in ranitidine treated healthy subjects and duodenal ulcer (DU) patients using gastric perfusion aspiration system and back titration of gastric perfusate to original pH 6.0. Basal alkaline secretion showed periodic fluctuations reaching peaks at phase III of the migrating motor complex (MMC) in the stomach.

Double blind controlled study on the effect of sucralfate on gastric prostaglandin formation and microbleeding in normal and aspirin treated man.

Two groups A and B each comprising 12 healthy young male subjects were used in a double blind, placebo controlled trial to assess the effects of 1.0 g sucralfate qid on prostaglandin (PG) generation and mucosal integrity in the intact and aspirin-treated stomach. Mucosal formation and luminal release of PGE2, 6-keto-PGE1 alpha and thromboxane B2, gastric microbleeding and DNA loss (integrity indicators) and basal and pentagastrin induced acid secretion were measured after placebo and sucralfate treatment in subjects without (group A) and with administration of 2.

Effects of somatostatin-14 and somatostatin-28 on plasma hormonal and gastric secretory responses to cephalic and gastrointestinal stimulation in man.

This study was designed to determine the influence of cephalic and gastrointestinal meal stimulation on plasma levels of somatostatin-like immunoreactivity (SLI) and to compare plasma hormonal and gastric secretory effects of somatostatin-14 (SS-14) and its putative prohormone, somatostatin-28 (SS-28), in humans. Cephalic stimulation induced by modified sham feeding did not affect plasma SLI, whereas a gastric liver extract meal caused a significant increase in SLI. Infusion of SS-28 dose-dependently suppressed gastric acid, serum gastrin, and plasma pancreatic polypeptide (PP) responses to cephalic and gastrointestinal stimulation.

Effect of meciadanol on gastric secretion and aspirin-induced gastric mucosal injury in humans.

The aim of this study was to assess the effects of a newly synthesized flavonoid, meciadanol, on gastric secretion and on aspirin-induced gastric mucosal injury in healthy humans. In vitro experiments have shown that meciadanol (INN proposed) inhibits histidine decarboxylase in gastric cells. In our study meciadanol did not affect either basal or pentagastrin-stimulated gastric acid secretion or pepsin secretion and did not produce any endoscopic or histological changes in the stomach or duodenum.

Generation of prostaglandins in gastric mucosa of patients with peptic ulcer disease: effect of nonsteroidal antiinflammatory compounds.

Human fundic mucosa generates various prostaglandins (PGs), particularly PGE2, and tromboxanes. This generation appears to be significantly lower in gastric ulcer patients than in duodenal ulcer patients or normal subjects. Nonsteroidal antiinflammatory compounds (NOSAC), such as aspirin or indomethacin, greatly reduce the PG biosynthesis and cause mucosal damage, including mucosal erosions and hemorrhages observed at endoscopy, increased gastric microbleeding and DNA loss.

Prostaglandins in peptic ulcer disease: effect of nonsteroidal anti-inflammatory compounds (NOSAC).

This study shows that human fundic mucosa generates various PGs, particularly PGE2, and thromboxanes and this generation appears to be significantly lower in gastric ulcer than in duodenal ulcer patients or normal subjects. Non-steroidal antiinflammatory compounds (NOSAC), such as aspirin and indomethacin, greatly reduce the PG biosynthesis and cause mucosal damage including mucosal erosions and haemorrhages observed at endoscopy, increased gastric microbleeding and DNA loss. In contrast, carprofen, a novel NOSAC with good antiinflammatory properties and gastric tolerance, failed to affect mucosal generation of PGs and did not influence gastric mucosal integrity.

Action of omeprazole (a benzimidazole derivative) on secretory responses to sham feeding and pentagastrin and upon serum gastrin and pancreatic polypeptide in duodenal ulcer patients.

The effects of omeprazole, a benzimidazole derivative, have been determined on the secretory responses to modified sham feeding and pentagastrin, and upon serum gastrin and pancreatic polypeptide concentrations in duodenal ulcer patients. Intragastric administration of omeprazole in doses of 2 and 6 mumol/kg produced, respectively, about 50% and 90% reduction in acid outputs in responses to modified sham feeding and pentagastrin without affecting serum gastrin and pancreatic polypeptide response to modified sham feeding.

The use of carprofen, a non-steroidal antiinflammatory agent, in peptic ulcer diseases.

The effects of carprofen (Roche), a nonsteroid antiinflammatory agent, on gastric secretion, serum gastrin level, electropotential difference (PD), gastric microbleeding, DNA loss, and the generation of mucosal prostaglandins (PGs) were examined in 20 duodenal ulcer patients with active ulcer (15 patients) or in remission (5 patients). Carprofen administered for one-week period at a therapeutic dose (300 mg/day) was well tolerated by all ulcer patients and no adverse effects were observed during or after treatment. Endoscopy performed after carprofen treatment showed complete ulcer healing in 9 out of 15 patients and no exacerbations were observed in the rest of patients.

Effect of enkephalin and naloxone on gastric acid and serum gastrin and pancreatic polypeptide concentrations in humans.

The effects of a synthetic enkephalin analogue with prolonged opioid activity, D-ala-2-enkephalin (ala-enk) and naloxone given alone or in combination, on vagally, pentagastrin- and histamine-induced gastric secretion and plasma hormonal responses to vagal stimulation have been studied in healthy subjects. D-ala-2-enkephalin reduced basal gastric acid and pepsin secretion, and caused a dose-dependent inhibition of gastric secretory responses to modified sham-feeding and pentagastrin but not to histamine. It increased serum gastrin concentration and suppressed plasma pancreatic polypeptide response to modified sham-feeding.

Comparison of prostaglandin E2 and ranitidine in prevention of gastric bleeding by aspirin in man.

This study was designed to compare the effect of oral administration of PGE2 (0.5 mg/kg) and ranitidine in larger (100 mg/dose) or smaller (10 mg/dose) doses on aspirin-induced gastric microbleeding and DNA loss determined chemically in gastric washings in eight healthy subjects. Aspirin (0.

Prostaglandins and vagal stimulation of gastric secretion in duodenal ulcer patients.

The effects of a stable prostaglandin (PG) E2 analog (15-R-15 methyl PGE2) and aspirin, a potent inhibitor of cyclooxygenase, on modified sham-feeding (MSF)-stimulated gastric secretion and serum gastrin and pancreatic polypeptide (PP) levels were measured in patients with duodenal ulcer. PGE2 analog given orally significantly reduced gastric acid and pepsin secretion and suppressed serum PP but not gastrin responses to MSF. Suppression of PG generation in the gastric mucosa did not influence the secretory or hormonal responses to MSF.

Effect of carprofen and indomethacin on gastric function, mucosal integrity and generation of prostaglandins in men.

The effects of indomethacin and carprofen on gastric secretion, serum gastrin level, electropotential difference, gastric microbleeding, DNA loss, mucosal blood flow and the production of mucosal prostaglandins (PGs) were investigated in a double-blind cross-over study in 18 healthy volunteers after one week of treatment. We did not observe any significant changes in basal and pentagastrin-stimulated gastric secretory parameters, serum gastrin level and electro-potential difference before and after treatment with these drugs. Mucosal blood flow was significantly reduced following indomethacin treatment.

Effect of human pancreatic polypeptide and its C-terminal hexapeptide on pancreatic secretion in man and in the dog.

Human pancreatic polypeptide (HPP) and its C-terminal hexapeptide (HP-PP) were infused intravenously in graded doses into healthy human subjects and dogs with chronic pancreatic fistula during submaximal stimulation with secretin. Plasma levels of PP were measured by radioimmunoassay, and pancreatic volume flow and bicarbonate and protein outputs were monitored. PP and HP-PP in humans did not affect secretion-induced volume flow or bicarbonate secretion, but at the highest doses it reduced the protein outputs.