Changes in erythrocyte glucose-6-phosphate dehydrogenase (G6PD) and reduced glutathione (GSH) activities in the development of senile and diabetic cataracts.

Oxidative and osmotic stress have been implicated in the pathogenesis of cataracts. Reactive oxygen intermediates (ROI) mediate peroxidation of membrane lipids and cause irreversible damage to lens proteins. The purpose of this study was to assess the changes in erythrocyte glucose- 6-phosphate dehydrogenase enzyme (G6PD) and reduced glutathione (GSH) levels in the development of senile and diabetic cataracts. The activity of erythrocyte G6PD and the concentration of GSH were measured to assess changes in oxidation-reduction status. The oxidation-reduction status of 26 non-diabetic non-cataract (control) subjects were compared with 24 diabetic non-cataract, 30 diabetic cataract and 28 non-diabetic cataract subjects. The results revealed that the GSH and G6PD levels of the subjects with senile cataracts were significantly lower than the subjects without cataracts. The present study reveals the risk of developing senile cataracts is associated with decreased levels of erythrocyte G6PD and GSH. In the formation of diabetic cataracts an adequate supply of NADPH (G6PD activity) is essential to produce osmotically active sorbitol in the lens.

Hepatitis B and C virus markers among new entrant medical students.

AIM: To investigate the presence of hepatitis B and C virus markers in new entrant medical students at the Faculty of Medicine, University of Kelaniya. METHOD: 456 students (mean age 24 years, SD 3.5, 257 men) were investigated before they were exposed to clinical work, using a questionnaire to assess sociodemographic factors and possible risk factors for contracting hepatitis B or C. Blood samples were tested for HBs Ag and anti HBs (n = 456), and anti-HCV (n = 162 randomly selected samples) with a third generation sandwich radioimmunoassay technique. RESULTS: The students were from 20 of the 25 districts in the country, although their distribution was not inform. A past history of hepatitis or jaundice was obtained from 24 (5.3%) and 6 (1.3%) students respectively. None of them had been vaccinated against hepatitis B. At least one risk factor for hepatitis B or C was present in 32 (7%) of them. None of the samples were positive for HBsAg or anti-HCV, and only two (0.44%) were positive for anti-HBs. CONCLUSION: Our results support the view that exposure to hepatitis B and C seems to be uncommon in this country, at least up to young adulthood. As most new entrant medical students are not immune to these infections there is a strong case to vaccinate them against hepatitis B before they are exposed to clinical work.