Selenite-induced epithelial damage and cortical cataract.

The purposes of these experiments were 1) to measure microscopic changes in the epithelium associated with selenite cataract, and 2) to describe the formation and subsequent clearing of selenite cortical cataract. Fourteen-day old suckling rat pups received a single subcutaneous injection of an overdose of sodium selenite at 2.25 mg Se/kg b.w. Development of cortical cataract was observed by biomicroscopy, and changes in epithelium were studied by light microscopy of flat-mounted lens epithelia. Selenite administration caused cortical cataract 15-30 days after injection in addition to previously characterized nuclear cataract. The cortical cataract progressed through equatorial vacuolization, opacity, and finally clearing of the cataract. Mitosis was suppressed and karyorrhexis was observed in the germinative zone of the epithelium 5 hours after selenite injection. Pathological disorganization of the epithelium followed. Changes included vacuolization, loss of meridional rows, and defective fiber formation. Restoration of epithelial morphology was associated with clearing of cortical opacity. Epithelial damage at 5 hours was the earliest change yet recorded for selenite cataract, and these data are consistent with our working hypothesis that the initial site of attack of selenium in both cortical and nuclear cataract is the lens epithelium.

Recruitment of ethnic and socio-economically disadvantaged students into dentistry.

A program designed to attract and graduate underrepresented minorities and disadvantaged students in dentistry is reported. The program consisted of three phases: career orientation, recruitment, and academic enrichment/retention. In the six years of this program's existence, the number of minority students enrolled increased from 1 to 28, including 12 who were graduated by June 1979. Only two were lost because of academic difficulties. An analysis of grades and tutorial needs showed that students experienced the most difficulty with first-year basic science courses. Recommendations are presented for program improvement.