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Biomedical subjects

R H Hunt

Publications and source records attributed to R H Hunt.

At least 217 records · Page 12Linked to original sources
PubMed1986

The correlation between acid suppression and peptic ulcer healing.

Suppression of gastric acid forms the basis of treatment of duodenal and gastric ulcer, but the precise relationship between suppression of acidity and healing rates has not been defined. We examined the results of controlled trials and clinical pharmacological studies of 24-h intragastric acidity involving antisecretory agents. Data on 24-h and nocturnal hydrogen ion activity and nocturnal acid output were obtained, and the healing rates in duodenal ulcer were calculated. Duodenal ulcer healing rates after 4 weeks showed a significant correlation with suppression of 24-hour hydrogen ion activity (r = 0.63; P less than 0.05), and a highly significant correlation between healing and the suppression of nocturnal hydrogen ion activity (r = 0.93; P less than 0.0001). Nocturnal acid output was not significantly correlated. For gastric ulcer, no such association was seen for suppression of either 24-hour or nocturnal hydrogen ion activity. Duodenal ulcer is regarded as an acid-related disorder, but in gastric ulcer other factors may be more important in pathogenesis and treatment.

Anti-Ulcer Agents↗
PubMed1986

Field sampling of Anopheles mosquitoes for correlated cytogenetic, electrophoretic and morphological studies.

Anopheline mosquitos were preserved in liquid nitrogen for up to 8 months prior to dissection and preparation of ovarian polytene chromosomes. The 23 preparations examined all had excellent chromosomes. A method is described for the preservation of the wings, legs and palps of these mosquitos as museum specimens for taxonomic studies; the remaining tissues from the frozen specimens can then be used for electrophoresis. Blood meal identification can be carried out on the undigested stomach contents.

Animals↗
PubMed1986

Effects of low dose omeprazole on gastric secretion and plasma gastrin in patients with healed duodenal ulcer.

The effects of seven days' treatment with omeprazole 5 and 10 mg daily on 24 hours gastric secretion and plasma gastrin concentrations were studied in a randomised double-blinded placebo-controlled study of six male patients with healed duodenal ulcer. Omeprazole 5 mg daily reduced mean daytime and nocturnal intragastric acidity by 31.4 and 40.1%, respectively. Omeprazole 10 mg per day produced very similar reductions of 33.6 and 42.0%, respectively. Total nocturnal acid output was reduced by 63.9% and 63.2%, respectively, by omeprazole 5 and 10 mg daily. There was a large degree of inter-subject variability in response to these low doses of omeprazole. Consequently, neither dose showed a statistically significant antisecretory effect when compared with placebo. Neither dose of omeprazole significantly affected fasting levels of gastrin, but omeprazole 10 mg daily produced a significant (P less than 0.05) increase in the integrated gastrin response to a meal. The lack of consistent antisecretory effect to low dose omeprazole is in accord with previous studies. This suggests that doses of 20 mg per day or greater are required to produce a consistent effect on acid secretion.

Adult↗
PubMed1985

Epidemic hypochlorhydria.

During a study of gastric secretion four out of six previously healthy subjects developed hypochlorhydria after a transient illness with nausea, vomiting, and abdominal pain. Mean basal and peak acid outputs were 0 and 2.3 mmol (84 mg)/h one month after the onset of illness and 1.5 and 27.0 mmol/h (55 and 984 mg/h) at eight months' follow up. Two of the subjects were followed up at 18 months, when mean basal and peak acid outputs were 3.9 and 33.5 mmol/h (142 and 1221 mg/h). No endoscopic abnormality was seen at one and eight months, but biopsies showed active superficial gastritis, which resolved in one subject and became chronic in two. Schilling tests performed in three subjects at eight months showed diminished retention of vitamin B12. During hypochlorhydria a 24 hour intragastric analysis was performed for total and nitrate reducing bacteria, pH, and concentrations of nitrite and total and stable N-nitroso compounds. Of the 48 samples of gastric juice examined, 47 had bacterial growth of more than 10(6) organisms/ml and 46 had growth of nitrate reducing bacteria of more than 10(5) organisms/ml. Mean intragastric nitrite concentrations were 10 times higher than in a group of eight healthy controls. Both mean total and mean stable N-nitroso compound concentrations, however, were not appreciably different from those in controls. Although community transmission was a possibility, serological screening and electron microscopy of gastric biopsy specimens failed to show an infective cause. Transmission of an unidentified enteric pathogen via a contaminated pH electrode was therefore suspected. Thus gastric juice should not be returned to the stomach after contact with a contaminated glass electrode as this is a possible cause of atrophic gastritis.

Achlorhydria↗
PubMed1985

Single nocturnal doses of pirenzepine effectively inhibit overnight gastric secretion.

The gastric antisecretory effects of two dose levels of pirenzepine given at night were investigated in a group of healthy male volunteers. Compared with placebo, three days of treatment with pirenzepine 100 mg nocte or 150 mg nocte inhibited mean nocturnal intragastric acidity by 54% and 53%, respectively (p less than 0.01). The volume of gastric juice secreted was reduced by 47% and 52% (p less than 0.005), by 100 mg and 150 mg nocte, respectively. Each dose suppressed mean gastric acid output by 67% (p less than 0.001). Pepsin output was not significantly altered. There were no differences in effect between the two dose levels studied, but side-effects such as dry mouth were only seen with the higher dose. Pirenzepine 100 mg is the optimum dose which can conveniently be given at night. This will limit side-effects, and may be a useful treatment for patients with duodenal ulcer.

Adult↗
PubMed1984

Effect of no treatment, cimetidine 1 g/day, cimetidine 2 g/day and cimetidine combined with atropine on nocturnal gastric secretion in cimetidine non-responders.

We have studied nocturnal acid secretion in patients with duodenal ulcer who met predetermined criteria of poor clinical response to cimetidine. Different groups of patients were investigated receiving either no treatment, cimetidine 1 g/day, cimetidine 2 g/day or cimetidine 1 g/day combined with atropine 4.8 mg/day. The results were compared with those obtained from other patients with duodenal ulcer who were studied in our department but who were not classified as according to their clinical response to cimetidine. The results show that despite adequate absorption, cimetidine has a decreased effect at controlling acid secretion in the poor responders and that increasing the dose of drug does not improve response. Control of acid output was, however, dramatically improved when cimetidine was combined with atropine which suggests that patients who do not respond to H2-receptor blockade should be treated by a combination of cimetidine with an anticholinergic agent.

Atropine↗
PubMed1984

Comparison of ranitidine and cimetidine maintenance treatment of duodenal ulcer.

Sixty-one patients with healed duodenal ulcer were studied during a 12-month maintenance trial with either 150 mg ranitidine at night or 400 mg cimetidine at night. Recurrences were determined at endoscopy after 6 and 12 months of treatment or because of symptomatic relapse. Ulcers recurred in 7 of 28 patients receiving ranitidine and in 8 of 33 patients receiving cimetidine. No serious side effects were encountered.

Adolescent↗
PubMed1983

Accuracy and value of the Hemoccult test in symptomatic patients.

Hemoccult faecal occult blood testing is widely advocated as a screening test for colorectal cancer but few studies have shown its correlation with conventional methods of investigation for colorectal disease. In a prospective study of 802 symptomatic patients with suspected colorectal disease there was good patient compliance (92.5%) and a high specificity for colorectal cancer (85.4%). The false positive rate was 8.6% (12 of 140 patients with positive results), and while the test result was positive in 22 of 26 colonic cancers the false negative rate for rectal cancer (45.4%) should not detract from its value as a screening test if proper digital anorectal and proctosigmoidoscopic examination are widely practised. A positive Hemoccult test result is a useful indicator for the need to proceed to full colorectal investigation, including colonoscopy.

Adolescent↗