The efficacy of omeprazole twice daily with supplemental H2 blockade at bedtime in the suppression of nocturnal oesophageal and gastric acidity.

BACKGROUND: It has been presumed that nocturnal acid breakthrough may pose a risk for the development of nocturnal gastro-oesophageal reflux. AIM: To investigate the occurrence of gastro-oesophageal reflux and acid breakthrough during polygraphically monitored sleep under conditions of powerful acid suppression with omeprazole 20 mg b.d. and an additional dose of ranitidine at bedtime. METHODS: Nineteen individuals with symptomatic gastro-oesophageal reflux disease were studied. Each individual was studied on two occasions subsequent to 1 week of 20 mg of omeprazole treatment b.d. Subjects underwent 24-h oesophageal and gastric pH recording, with polysomnographic monitoring. Participants received either 150 mg ranitidine at bedtime or placebo, prior to a provocative meal. RESULTS: Ranitidine administration resulted in a significant (P < 0.01) reduction in the percentage of time the intragastric pH < 4.0. There was no significant difference with regard to measures of gastro-oesophageal reflux, and reflux events were not noted to occur with a significantly greater frequency during periods of nocturnal acid breakthrough compared with control intervals without acid breakthrough. CONCLUSIONS: The administration of 150 mg ranitidine at bedtime did not significantly alter the occurrence of sleep-related gastro-oesophageal reflux.

The role of age and salivation in acid clearance in symptomatic patients with gastro-oesophageal reflux disease.

BACKGROUND: Cisapride has been shown to have not only prokinetic effects, but also salivary stimulating effects. Both of these mechanisms play an important role in the acid clearance of the oesophagus. AIM: To access the efficacy of cisapride in facilitating acid clearance in patients with symptomatic gastro-oesophageal reflux disease. METHODS: Fifteen older adults and 15 younger adults with symptomatic gastro-oesophageal reflux disease completed the study. The acid clearance test was accomplished by infusing 15 mL of 0.1 N HCl into the distal oesophagus, and the number of swallows was determined to achieve an oesophageal pH of 4.0. This was accomplished under baseline conditions and salivary stimulation with a peppermint lozenge. After 1 week of treatment with cisapride (10 mg, q.d.s.), the acid clearance test was repeated. RESULTS: The lozenge produced a significant decrease in the number of swallows compared to baseline in both groups (P < 0.01). There was a significant decrease in the number of swallows after the treatment with cisapride compared to baseline in both groups (P < 0.01). No significant difference was found in the number of swallows when comparing cisapride with lozenge. CONCLUSIONS: Cholinergic stimulation of salivation is an effective means of facilitating oesophageal acid clearance. Drugs, such as 5 hydroxytriptamine (5-HT)4-receptor agonists, should be considered as potentially important compounds in the treatment of gastro-oesophageal reflux disease.

Molecular analysis of the Drosophila catalase gene.

The main objective of this study was to isolate and characterize the catalase gene and accompanying cis-regulatory regions in Drosophila melanogaster. Genomic clones were obtained on the basis of cross-hybridization to catalase cDNA and a 7-kb SalI-KpnI fragment encompassing the catalase gene was introduced into Drosophila by P element-mediated transformation. A single transgene, when placed in a catalase null background, was sufficient to restore resistance to H2O2 as well as reduce susceptibility to early death. DNA sequence of the catalase gene domain was obtained. This included 1365 bp of sequence upstream of the transcription initiation site and 1423 bp downstream of the termination codon. The Drosophila catalase gene is composed of 3 exons, encoding 19, 307, and 180 amino acids, which are separated by 3520- and 96-bp introns. Sequence analysis of the promoter domain is presented, revealing multiple sequence similarities between catalase and Cu,Zn superoxide dismutase promoter domains. Developmental RNA get analysis shows that peaks of catalase mRNA accumulation correspond roughly with major peaks of ecdysone titer during third instar and pupal stages. Candidate ecdysone response element sequences are noted downstream of the catalase polyadenylation site.