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Biomedical subjects

N K Dorsey

Publications and source records attributed to N K Dorsey.

3 recordsLinked to original sources

Standardized patient encounters. A method for teaching and evaluation.

The primary goal of medical education is to foster development of clinical competence in trainees at all levels. Variable clinical experience, inconsistent methods of instruction, and ambiguous evaluation criteria undermine this goal. Standardized patients, trained to consistently portray a wide variety of clinical cases, can help overcome many of these educational problems. This article describes the development and application of standardized patients throughout medical training at The University of Texas Medical Branch, Galveston, in the freshman interviewing course, the second-year physical diagnosis course, third-year clerkships, a fourth-year final exercise, and residency training. Development of this program is discussed in the context of a broader literature in medical education, and investigation of variables affecting standardized patient and student performance is reported. Future directions for use of standardized patients in monitoring and promoting the development of clinical competence are discussed.

Clinical Competence↗

Effect of solvent on the histamine-releasing, enzyme-releasing, and mitogenic properties of the calcium ionophore A23187.

The potency of the calcium ionophore A23187 in inducing three activities of human leukocytes (histamine secretion from basophils, enzyme secretion from PMNs, and proliferation of lymphocytes) was markedly dependent on the solvent (DMSO versus ethanol versus aqueous buffer) used for its initial sonication. While 0.1 micrograms/ml of DMSO- and ethanol-solubilized A23187 induced maximal histamine release from basophils and histaminase release from PMNs, concentrations of aqueous buffer-sonicated ionophore of greater than or equal to 1 microgram/ml were required for an equivalent response. Ionophore sonicated in organic solvents caused a maximum release of 40% of PMN beta-glucuronidase, at an optimal concentration tenfold higher than that required for maximal histaminase release; ionophore sonicated in aqueous buffers, even at high concentrations, effected a release of less than 5% of cellular beta-glucuronidase. A23187 also induced lymphocyte proliferation over a narrow concentration range; 0.05 micrograms/l of DMSO-sonicated ionophore induced optimal proliferation and concentrations greater than or equal to 0.2 micrograms/ml were toxic. Twofold higher concentrations of ethanol-sonicated ionophore and fourfold higher concentrations of aqueous-sonicated ionophore were necessary for maximal proliferation, and the magnitude of the maximal response with aqueous-sonicated A23187 was only one-half that of DMSO-solubilized agent. Ionophore-induced release of histamine from basophils and enzymes from PMNs was not cytotoxic, since ionophore induced neither LDH nor histamine release from heat-treated (47 degrees C) cells. These results explain several previous, discordant reports on the presence or absence of an effect of A23187 on cellular secretory events, on differing dose-response relationships, and on cytotoxic versus noncytotoxic mechanisms of action.

Anti-Bacterial Agents↗