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Biomedical subjects

G D Bell

Publications and source records attributed to G D Bell.

At least 163 records · Page 9Linked to original sources
PubMed1974

Liver structure and function in cholelithiasis: effect of chenodeoxycholic acid.

Although, in suitable patients, oral chenodeoxycholic acid (CDCA) dissolves gallstones, the results of recent animal studies suggest that it might be hepatotoxic. Liver function was therefore studied in patients with gallstones before and during treatment with CDCA and liver biopsies were carried out both in patients with cholelithiasis given bile acid therapy and in those who had been given no medical treatment. In 25 patients treated with 0.5-1.5 g CDCA/day (7-20 mg kg body weight(-1) day(-1)) there was no significant change in serum bilirubin, albumin, globulin, transaminase, isocitric dehydrogenase, alkaline phosphatase, and gamma glutamyl transpeptidase levels before and at monthly intervals during six months' treatment. The kinetics of bromsulphthalein (BSP) clearance and its apparent transport maximum were not significantly changed during CDCA therapy. The mean fasting serum bile acid concentrations of 18.0 +/- SEM 1.2 mumoles/litre before and 20.0 +/- 3.5 mumoles/litre during treatment were both significantly greater than control values. Liver histology was not appreciably different in 11 patients treated with CDCA from that in eight patients with untreated cholelithiasis and in three patients who had received CDCA three to four months before biopsy. These results suggest that in doses of 0.5 to 1.5 g/day CDCA is not hepatotoxic in man.

Adult↗
PubMed1973

Serum lipids in cholelithiasis: effect of chenodeoxycholic acid therapy.

Hypercholesterolaemia has been predicted as a possible complication of chenodeoxycholic acid treatment for gall stones. To exclude this, fasting serum lipids were measured in patients with stones before and at monthly intervals for six months after starting chenodeoxycholic acid. Before treatment half of a group of 36 patients with presumed cholesterol gall stones had serum cholesterol levels exceeding 260 mg/100 ml or serum triglyceride values greater than 160 mg/100 ml or both; these lipid levels were significantly greater than those in control subjects matched for age and sex. Treatment with chenodeoxycholic acid (0.5-1.5 g/day by mouth) did not change serum cholesterol levels but did significantly reduce serum triglyceride concentrations from a pretreatment level of 118 (+/- S.E. of mean 11.7) mg/100 ml to 95 (+/- 7.2) mg/100 ml after six months of therapy. The mechanism of this triglyceride-lowering action of chenodeoxycholic acid is not known, but it may have therapeutic value in patients with hypertriglyceridaemia.

Adult↗
PubMed1972

Lithogenic bile in patients with ileal dysfunction.

Ileal disease or resection causes bile salt malabsorption and a reduction in the bile salt content of bile. Since cholesterol solubility requires adequate bile salt concentrations, depletion of the bile salt content of bile might, therefore, jeopardize cholesterol solubility and predispose to cholesterol gallstone formation. To study this, we examined biliary lipid composition in 10 patients with ileal dysfunction and in 25 healthy controls. Biliary lipid composition, as analysed in cholecystokinin-stimulated, bile-rich duodenal fluid, was shown to be representative of gallbladder bile and reproducible on repeat duodenal intubation. Nine of the 10 patients with ileal dysfunction had an abnormal, supersaturated bile in which the limits of cholesterol solubility were exceeded, and while nine of 25 control subjects also had an unstable bile, the mean bile composition in the ileal dysfunction group was significantly different from the control population. These studies provide a physicochemical explanation for the clinical observation that patients with ileal dysfunction have an increased incidence of gallstones.

Adult↗
PubMedDate not supplied

Dietary cyclandelate decreases pre-established atherosclerosis in the rabbit.

Rabbits were given a diet containing 1% (w/w) cholesterol for 7 weeks to initiate atherosclerosis and then transferred to a low-cholesterol diet (regression diet) with or without 0.5% (w/w) cyclandelate for 10 weeks. In those fed regression diet alone aortic atherosclerosis increased significantly. Cyclandelate treatment decreased the extent and severity of aortic atherosclerosis. Thus in rabbits receiving cyclandelate the total cholesterol and calcium content of aorta was decreased by 45% and 69% of control values, respectively. The effects of cyclandelate occurred without significant lowering of serum cholesterol or alteration of cholesterol content of liver or calcium content of serum, liver or muscle. The result suggests a specific action of cyclandelate on atheromatous accumulations of the aortic wall.

Animals↗
PubMedDate not supplied

Upper gastrointestinal endoscopy: a prospective randomized study comparing continuous supplemental oxygen via the nasal or oral route.

We have examined the efficacy of supplemental oxygen in preventing episodes of significant arterial desaturation (SpO2 less than 90%) during upper gastrointestinal endoscopy. We have compared the effects of 2 liters.min-1 of oxygen given orally via the bite-guard with the same flow rate via nasal cannulas and have also examined the effects of pre-oxygenation. Results of this study at a flow rate of 2 liters.min-1 have been compared with previously published results at a flow rate of 3 liters.min-1. Although in this study fewer episodes of desaturation were seen in the orally supplemented group compared with the nasal group, the difference observed was not statistically significant. Pre-oxygenation significantly reduced episodes of desaturation (SpO2 less than 90%, p less than 0.01) and prevented SpO2 falls below 85% in all patients studied. Supplemental oxygen given at a rate of 2 liters.min-1 was as effective as that given at a rate of 3 liters.min-1 in preventing significant desaturation, as previously defined, during the procedure. We therefore recommend the use of supplemental oxygen at a flow rate of 2 liters.min-1 in all high risk patients and conclude that the oral route has practical advantages and is at least as effective as nasal cannulas.

Endoscopy, Gastrointestinal↗