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Biomedical subjects

O D Kowlessar

Publications and source records attributed to O D Kowlessar.

At least 19 recordsLinked to original sources
PubMed1988

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. Examinations were scored in two ways: in the conventional way, using the total number of correct responses, and by a confidence-weighted technique based on the level of certainty indicated for each response by the examinee. Only the conventional score determined the grade; the confidence-weighted score was calculated for the purely experimental purposes of this study. Overconfidence and underconfidence indices were also calculated by using the indicated levels of certainty. Improvements in the psychometrics of the examinations were observed when confidence-weighted scoring was used. In multiple-regression models, the confidence-weighted scores and indices of over- and underconfidence contributed significantly to predicting scores of the students studied on Parts I and II of the National Board of Medical Examiners examinations, whereas the conventional score did not contribute to the prediction of Part II scores. Significant differences on junior clerkship examinations and ratings were observed between those who were highly overconfident and those who were slightly overconfident. The highly overconfident students also estimated higher future incomes than did those who were slightly overconfident.

Attitude↗
PubMed1982

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. We feel that with the increased risk of gastrointestinal bleeding in the spinal cord patient and the accompanying significant mortality, early endoscopy is essential for accurate diagnosis since clues to the presence, etiology, and severity of the bleeding are often lacking.

Adolescent↗
PubMed1980

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.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

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. Therefore, this concentration was used for all test bile acids studied. Test solutions included the tri- and di-substituted bile acids: cholic acid, hyocholic acid, 3 alpha, 7 beta, 12 alpha-trihydroxycholanic acid, 3 alpha, 12 alpha-dihydroxy-7-ketocholanic acid, ursodeoxycholic acid, 3 alpha-hydroxy-7-ketocholanic acid, 7 alpha, 12 alpha-dihydroxycholanic acid, and hyodeoxycholic acid. Only three bile acids, deoxycholic acid, chenodeoxycholic acid, and 7 alpha, 12 alpha-dihydroxycholanic acid were associated with net secretion of water and sodium. Cecal histology after incubation with bile acids revealed mucosal alterations in those sacs in which secretion occurred, but not where absorption was noted. These data indicate that bile acid-associated water and sodium secretion in the rat cecum requires a specific bile acid structure with a definite spatial relationship of the hydroxyl groups. Secretion occurred only with two alpha-hydroxyl groups in either the 3, 7, or 12 positions.

Animals↗
PubMed1976

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. It is suggested that impairment of deconjugation or 7alpha-dehydroxylation might be contributing to the low deoxycholic acid observed in azotaemic patients. Unusual bile acids: ursodeoxycholic acid, 3-hydroxy-7-keto-cholanic acid, and 3,12-dihydroxy-7-keto-cholanic acid were also noted in intestinal aspirates of azotaemic patients. The presence of these bile acids in conjunction with low deoxycholic acid correlates with the symptom of diarrhoea in azotaemic patients, and may contribute to the pathogenesis of diarrhoea in these patients.

Adolescent↗
PubMed1970

Celiac disease.

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Blood Group Antigens↗