A special Students' Committee on Medical Education was established by the Student Union of Nippon Medical School. The members of this committee are all volunteers and have carried out several plans to improve the educational environment at our school. In 1999, the Students' Committee on Medical Education proposed holding joint meetings with the Education Committee of Nippon Medical School. The meeting was to allow communication between students and teachers for improving the curriculum. The volunteer faculty members of the Education Committee and students have held joint meetings seven times from November 1999 through February 2001. Discussions between students and teachers have changed ideas on both sides and have led to improvements in some educational programs, such as clinical internship during the summer vacation.

In this study, the effects of mono(2-ethylhexyl) phthalate (MEHP), one of metabolites of di(2-ethylhexyl) phthalate, on immature Shiba goat testes in vitro were examined. The testes of 2-month-old Shiba goats were cut into smaller pieces, and seeded in medium. At 1, 3, 6 and 9 hr after administration of MEHP at various concentrations (0, 100 nmol ml-1, 1 nmol ml-1, and 1 x 10-3 nmol ml-1, respectively), the specimens were obtained for light and transmission electron microscopic observations. As a result, at 1 hr after exposure to MEHP, the vacuolization and nuclear membrane rupture appeared in Sertoli cells. Such alterations tended to gradually increase in number in timeand dose-dependent manners. Moreover, by MEHP treatment, apoptotic spermatogenic cells (characterized with chromatin condensation, cytoplasm shrinkage without membrane rupture, still functioning cell organelles, and packed cell contents in membrane-bounded bodies), apoptotic Sertoli cells (characterized with nuclear membrane lysis, nuclear condensation), necrotic spermatogenic cells (characterized with swollen and ruptured mitochondria, plasma membrane lysis, spilt cell contents, and chromatin clumps), and necrotic Sertoli cells (characterized with marginated chromatins along the nuclear membrane, ruptured vesicles within the MNB, some swollen and ruptured cell organelles, e.g. mitochondria) could be identified. Conclusively, ultrastructurally the treatment with MEHP at low concentration tends to lead spermatogenic and Sertoli cells to apoptosis, whereas that at high concentration tends to lead spermatogenic and Sertoli cells to necrosis. Thus, the testicular tissue culture is advantageous for screening testicular toxicity of chemicals.
Animals ; Apoptosis/drug effects/physiology ; Diethylhexyl Phthalate/*analogs&derivatives/*toxicity ; Goat Diseases/*chemically induced/pathology ; Goats ; Male ; Microscopy, Electron, Transmission/veterinary ; Necrosis ; Sertoli Cells/ultrastructure ; Spermatozoa/drug effects/pathology/ultrastructure ; Testicular Diseases/*chemically induced/pathology ; Testis/*drug effects/metabolism/pathology/ultrastructure ; Vacuoles/physiology/ultrastructure