The clinical learning environments in medicine, paediatrics and surgery clerkships

Using questionnaires, the students of the 1981 graduating class from McGill's Faculty of Medicine were investigated for their perceptions of the nature of the clinical instruction and of the roles of the consultant, resident and intern staffs during clerkships in medicine, paediatrics and surgery. Personal student diaries were used to assess time spent on various clinical activities. The results indicated that students perceived learning to be different in the three disciplines, with the acquisition of clinical skills (technical and problem-solving skills) greater in medicine and surgery than in paediatrics, and the acquisition of interpersonal skills and factual knowledge greater in paediatrics than in medicine and surgery. Students perceived themselves as passive observers in surgery and formed personal relationships more easily with staff in medicine and paediatrics than in surgery. In contrast, students perceived more emphasis on team effort in surgery. Time spent on activities related to direct patient encounter was greatest in medicine. The findings suggest that the learning environments in clinical disciplines are not homogeneous and this has implications for curricular planning and clinical teaching.     

Cytokeratin 20 expression by non-invasive transitional cell carcinomas: potential for distinguishing recurrent from non-recurrent disease

Although approximately 50% of patients with non-invasive (T_a) papillary transitional cell carcinoma show no recurrence of their disease, current histopathological approaches cannot distinguish this sub-group from those patients in whom the disease will recur. In this 5 year retrospective study, we have shown that cytokeratin 20 (CK20) was expressed in 19 of 29 (65.5%) of non-invasive papillary tumours of grades 1 or 2. CK20 expression patterns were predictive of disease non-recurrence in a sub-group of eight patients, representing 51.7% of patients with non-recurrent disease. In normal bladder mucosa, CK20 expression was restricted to the terminally-differentiated superficial cell. In eight CK20-positive tumours which showed no recurrence at 5 years, CK20 expression was either restricted to, or most intense in, the luminal cells of the papillae. This pattern of expression was not seen in any of the 15 tumours from the recurrent group. Disruption of normal CK20 expression was highly significantly correlated with recurrent tumours. These results suggest that changes in the expression of differentiation-associated antigens, such as CK20, may be useful in predicting benign versus malignant behaviour and may, therefore, be useful in defining treatment strategies.     

THYROID DEFICIENCY AND CELL DEATH IN THE RAT CEREBELLUM DURING DEVELOPMENT

Thyroid deficiency and cell death in the rat cerebellum during development.
The [³H]-DNA content of the cerebellum remained constant during a period from 4 h to 8–9 days after the administration of [³H]-thymidine both to normal rats at 6 and 12 days of age and to thyroid deficient rats at 6 days. On the other hand, when [³H]-thymidine was given to 12-day-old thyroid deficient rats, a progressive decrease in the cerebellar content of [³H]-DNA was observed during the first 4 days after the injection. These findings, together with previous results showing a markedly elevated pyknotic index in the internal granular layer of the 12-day-old hypothyroid cerebellum, are consistent with there being an increased death of newly formed and differentiating granule cells in thyroid deficiency towards the end of the second week of postnatal life.