Students' certainty during course test-taking and performance on clerkships and board exams.

Psychometric aspects of multiple-choice tests were investigated using a confidence-weighted scoring technique. The contributions of two indices, overconfidence and underconfidence, in the prediction of subsequent academic performance of examinees were studied. A total of 444 sophomore students (entering classes of 1982 and 1983) in one medical school were asked to indicate their confidence, on a 5-point scale (100, 75, 50, 25, and 0), in the correctness of their responses to each multiple-choice item on an Introduction to Clinical Medicine examination.

An unusual cause of GI bleeding in a quadriplegic: report of a case and review of the literature.

The authors report a case of upper gastrointestinal hemorrhage in a quadriplegic. The cause was a Mallory-Weiss tear, a previously unrecognized problem in these patients. The incidence of bleeding in patients with spinal cord injury is as high as 25 percent in the few reported series.

Evaluation of the 3 alpha-hydroxysteroid dehydrogenase assay for ursodeoxycholic acid, and 7 oxo- and 12 oxo- bile acids.

3 alpha-Hydroxysteroid dehydrogenase (SDH) quantifies ursodeoxycholic acid, 3 alpha,12 alpha-diol-7-one-5 beta-cholanoic acid, 3 alpha-ol-7-one-5 beta-cholanoic acid, and 3 alpha,7 alpha-diol-12-one-5 beta-cholanoic acid in a manner similar to the more commonly measured bile acids, exemplified by taurocholic acid. The type of oxygen function at the 7 or 12 position and its orientation at the 7 position has no effect on the rate of reaction of the enzyme. Discrepancies in the glycine/taurine ratios of patient intestinal aspirates containing ursodeoxycholic acid and oxo bile acids, obtained by SDH and gas-liquid chromatographic methods are not a result of the enzyme assay procedure.

Structure of bile acids associated with secretion in the rat cecum.

An isolated in vivo rat cecal loop technique was utilized to determine what structure of bile acids is required to stimulate net colonic secretion of water and sodium. A dose response curve for water and sodium movement was determined for deoxycholic acid (1-6 mM) and chenodeoxycholic acid (3-6 mM). Both of these bile acids were associated with significant secretion of water and sodium at 4 mM concentration.

Abnormal intestinal bile acid distribution in azotaemic man: a possible role in the pathogenesis of uraemic diarrhoea.

Proximal intestinal bile acids have been studied in 14 ambulatory patients with varying degrees of azotaemia. When compared with normal subjects, the azotaemic patients showed a significant decrease in deoxycholic acid. Analysis of faecal bile acids of a patient with low intestinal deoxycholic acid also showed low deoxycholic acid with a preponderance of primary bile acids, and contrast with faecal bile acids of a normal subject and a patient with normal intestinal deoxycholic acid.

Analysis of the conjugated bile acid distribution in human intestinal aspirates using gas liquid chromatography.

The conjugated bile acid pattern was evaluated in intestinal aspirates of five normal subjects and five patients known to have an abnormal bile acid distribution. The glycine/taurine (G/T) ratios for total bile acids were determined by gas liquid chromatography (GLC) and by enzymatic assay using 3-hydroxysteroid dehydrogenase (STDH). By both methods G/T ratios in normal samples approximated 3.

Analysis of the total bile acid distribution in human intestinal aspirates by gas liquid chromatography.

A method for the quantitative determination of the total bile acid content of human intestinal aspirates is presented. This method was applied to duodenal samples from ten normal subjects and distal jejunal samples from seven of these subjects. Enzymatic and radioactive monitoring of the procedures utilized yielded recoveries of 89 to 100 percent of bile acids.