[Student education in a laboratory for general practice skills]. / Studentundervisning i allmennmedisinsk ferdighetslaboratorium.

Clinical skills, like questioning and examining a patient, are developed gradually throughout the years of medical training. Basic skills should be mastered on graduation, but the teaching of skills in most medical schools is not systematic. We evaluated a pilot teaching project in a general practice (GP) skills laboratory. Students were randomised to an intervention group and a control group. Teaching was performed in small groups of one GP instructor and six students and consisted of four weekly three-hour sessions. For the control group, teaching was delayed until after evaluation. Evaluation of practical skills and communication skills was made with the students in random order by GP evaluators who did not know about the randomisation procedure. Each skill was scored as satisfactory or not satisfactory for each of five procedural elements. 56 fourth-year medical students volunteered. Evaluation was performed for 19 (68%) students in the training group and 18 (64%) in the control group. The training group performed better on practical skills, average score 9.7 (95% confidence interval 7.4 to 12.1) vs. 5.5 (3.2 to 7.8), (p = 0.01). There was no significant difference for communication skills, 7.7 (5.6 to 9.8) vs. 6.7 (4.6 to 8.7). Teaching clinical skills in a general practice skills laboratory is feasible. Practical skills may improve rapidly, at least for short-time performance, while our brief teaching in communication skills was not proved to be effective.

[Thallium scintigraphy in the diagnosis of coronary disease]. / Thalliumscintigrafi i diagnostisering av koronar hjertesykdom.

A retrospective analysis was performed in 371 patients who underwent stress thallium scintigraphy over a three-year period. The patient-group was highly selected. The majority had normal or uninterpretable exercise EKG. The purpose was to assess the clinical value of thallium scintigraphy, and to determine the accuracy of the test compared with coronary arteriography for diagnosis of coronary artery disease in 108 of the patients who had undergone cardiac catheterisation. For 79 patients (73%), the scintigraphic results were in complete accordance with the coronary arteriograms. Furthermore, critical review of the arteriograms showed discrete stenosis of less than 50% in another 12 of the patients with abnormal scans. This yields an overall diagnostic accuracy of 84%. The authors discuss some limitations of the method and possible causes of "false" perfusion defects. The results of the analysis are consistent with earlier reports, and emphasize thallium scintigraphy as a valuable diagnostic tool in coronary heart disease.

The effects of two different crystalloid cardioplegic solutions on cultured human endothelial cells.

The effects on cultured human endothelial cells of incubation with two standard crystalloid cardioplegic solutions (St. Thomas' and Bretschneider's) for one or five hours at 10 degrees C or 20 degrees C were studied. The cells were prelabelled with 51Cr and cell injury was measured by release of 51Cr, cell detachment, and by electron microscopy. The injury was also studied after a rewarming period of 35 minutes in cell culture medium at 37 degrees C. Endothelial cells incubated with cell culture medium, but otherwise treated in a similar way, served as controls. Both cardioplegic solutions caused significantly greater release of 51Cr than cell culture medium when incubated at 10 degrees C or 20 degrees C. The Bretschneider's solution induced slightly more release of 51Cr than did the St. Thomas' solution. The cells did not become detached during incubation. Electron microscopy of the cells after 5 hours with the cardioplegic solutions at 10 degrees C revealed contraction of the cells, mild intracellular oedema, swelling of mitochondria, and blebs or craters on the luminal surface of the cells. After rewarming in culture medium for 35 min the cells were not contracted and showed only minimal signs of injury, indicating a rapid and nearly complete reversibility of the changes. The present observations indicate that cultured endothelial cells get some protection, albeit not optimal, from the two crystalloid cardioplegic solutions tested. The presence of procaine-CL increased the injurious effect of the solutions.

Triiodothyronine (T3) binding to immunoglobulin G subclasses in a slightly hypothyroid woman.

A 44-year-old woman, with an earlier history of myxoedema, had stopped taking thyroxine and was found to have both a slightly elevated basal TSH level and an increased TSH response after thyroliberin stimulation. The T4 value was low borderline, and using a radioimmunoassay that separated free and antibody-bound hormone by polyethylene glycol precipitation, the T3 value was found to be less than zero. This last finding was explained by the existence of T3 antibodies in the patient's serum. The antibodies, being of the IgG class, did not bind T4, thyroglobulin or cytoplasmic thyroid antigen. The subclass IgG2, and to a lesser extent IgG1, IgG3 and IgG4, did bind T3. A Scatchard plot gave an antibody avidity constant of 4.28 x 10(8) l/mol and a binding site concentration of 3.8 x 10(-9) mol/l. Radioimmunoassay of total T3, after extraction with ethanol gave a high value. The concentration of free T3 was, however, just above the lower reference limit.