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Biomedical subjects

D G Thompson

Publications and source records attributed to D G Thompson.

142 records · Page 8Linked to original sources

Patients appreciate premedication for endoscopy.

Upper gastrointestinal endoscopy without sedation by means of a small diameter (9 mm) instrument is feasible but patients often remember the procedure as unpleasant, do not wish to have it repeated, and compare it unfavourably with a barium meal. In contrast, endoscopy with a larger instrument (13 mm) after diazepam sedation is usually well tolerated and often regarded as no more uncomfortable than a barium meal. Even when a narrow instrument is used, patients still benefit from premedication with diazepam, although return to normal activity is slower because of drowsiness.

Barium Sulfate↗

Normal patterns of human upper small bowel motor activity recorded by prolonged radiotelemetry.

In order to characterise human interdigestive cyclical motor activity, and its interruption by food, jejunal pressure changes in healthy volunteers were recorded continuously for 24 hours, using an ingested pressure-sensitive radiotelemetry capsule tethered at the duodenojejunal flexure. In 20 studies, the subjects fasted throughout; in another 20 studies they received a single standard meal. Using this technique, fasting motor complexes were easily detected. There was considerable variation in interdigestive cycle duration and in the interruption caused by food. The data were not normally distributed. The study indicates that any descriptions of 'atypical' jejunal motility patterns must take into account the wide variations seen in health, before they can be regarded as representing dysfunction or disease.

Adult↗

Mineralocorticoid replacement in Addison's disease.

Eight patients with treated Addison's disease were studied whilst receiving different doses of fludrocortisone together with a constant intake of glucocorticoid. Plasma renin activity (PRA), blood pressure, pulse rate and plasma potassium and urea concentrations were measured after 2-week periods on each dose. In two patients, PRA measurements indicated that mineralocorticoid replacement therapy had been inadequate. In four others, PRA remained normal throughout the study, even after fludrocortisone had been discontinued, suggesting that the drug was unnecessary for the maintenance of normal sodium balance in these patients. Asymptomatic fludrocortisone overdosage was indicated by a low plasma potassium concentration, but not by PRA measurements which failed in this study to distinguish between adequate and excessive mineralocorticoid replacement.

Addison Disease↗

Pericarditis and inflammatory bowel disease.

Pericarditis is an uncommon but important complication of inflammatory bowel disease. Five new cases are described and the published literature on nine other cases is reviewed. The pericarditis occurred during an active phase of the colitis in all our cases and was associated with other extra-colonic manifestations of colitis in three. No other cause for the pericarditis was identified and in all five cases it responded promptly to the administration of corticosteroid drugs.

Adolescent↗

Abnormal small-bowel motility demonstrated by radiotelemetry in a patient with irritable colon.

Jejunal motility was recorded for 47 h by telemetry from a tethered ingested radio-pill in a patient with irritable colon. In fasted controls, motor complexes are as frequent at night as during the day; the patient with irritable colon had a pronounced reduction in complexes when awake. Two prolonged episodes of pain were associated with irregular contractile activity, and ended when cyclical interdigestive activity resumed. This study suggests that irritable colon may be a disorder affecting the upper digestive tract.

Colon↗

Liquid chromatographic method for quantitation of glyphosate and metabolite residues in organic and mineral soils, stream sediments, and hardwood foliage.

A liquid chromatographic method for determining glyphosate (GLYPH) and its major metabolite aminomethylphosphonic acid (AMPA) in various environmental substrates is described. Ion-exchange column chromatography is coupled with post-column ninhydrin derivatization and absorbance detection at 570 nm. Use of a valve-switching technique allowed quantitation of both analytes in a single chromatographic run and eliminated slow-eluting, coextracted interferences. The method was successfully used to quantitate GLYPH and AMPA in organic and mineral soils, stream sediments, and foliage of 2 hardwood brush species. Mean recovery efficiencies for GLYPH as determined from fortified blank field samples were as follows: bottom sediment 84%, suspended sediment 66%, organic soils 79%, mineral soils 73%, alder leaf litter 81%, salmonberry leaf litter 84%, and artificial deposit collectors 87%. Precision for GLYPH determination was good with less than 14% coefficient of variation on mean recovery for all substrates. Limits of detection were lowest for sediments (0.01 microgram/g dry mass) and highest for foliage substrates (0.10 microgram/g dry mass). Using this system, 6 samples/person/day were routinely analyzed.

Chromatography, High Pressure Liquid↗