DNA repair induction by UV irradiation and various mutagens requiring metabolic activation in rat hepatocytes maintained in culture for several days.

Freshly isolated rat hepatocytes cultivated in Williams Medium E (WME) quickly lose their cytochrome P-450-dependent metabolic activities. A significantly better maintenance of cytochrome P-450 was achieved by supplementing WME with hormones and nutrients and 2% DMSO and 10% fetal calf serum. After 72-h cultivation in this medium the cytochrome P-450 content was still 72% of the amount measured in freshly isolated cells. Over the same period of time the activity of 7-ethoxycoumarin-O-deethylase dropped to approximately 55% of its initial value. DNA repair induction by UV irradiation, hydrogen peroxide, benzo[a]pyrene and 2-acetylaminofluorene was measured. A clear dose-dependent increase of the incorporation of [3H]thymidine was found with all agents tested, regardless of whether the treatment of the hepatocytes began 4 or 52 h after cell isolation. In the case of UV light and hydrogen peroxide the maximum effects were slightly lower after prolonged cultivation, whereas little change or even a slight increase was found with benzo[a]pyrene and 2-acetylaminofluorene. These results indicated that cell cultivation led to a slight loss of DNA repair activity but did not, despite the loss of cytochrome P-450, cause a decrease in DNA-damaging intermediates produced from the two indirect mutagens. The absolute amounts of [3H]thymidine incorporated by the solvent control cells of the 52-h groups was consistently found to be twice the level measured in the corresponding 4-h control groups. The incorporation of deoxy[3H]cytidine was not changed when tested in parallel. The increase in [3H]thymidine incorporation can therefore be explained by the assumption of a diminution of the thymidine pool during cell cultivation.

Restraint, body image and food attitudes in children from 12 to 18 years.

Body image, dietary restraint, attitudes to food and food intake pattern were assessed in a survey of 348 London schoolchildren from three age groups. The data revealed striking sex differences in body image, restraint and food attitudes, even in the youngest age group (12 to 13 years). The majority of girls felt too fat, attempted to restrict their food intake, and expressed guilt about eating. The boys expressed much less concern in all these areas. No differences were found across the age groups. The results suggested that normal English girls experience significant levels of distress over eating and weight.

A metastasising ameloblastoma associated with renal calculi and hypercalcaemia.

A young male had an assumed dentigerous cyst marsupialized and later a recurrent ameloblastoma resected. Eleven years later he was admitted with renal stones and hypercalcemia and metastases of the ameloblastoma in the left lung were discovered. Death occurred as a result of spinal and hepatic spread of his tumor and thrombosis of the renal veins. Renal calcification was demonstrated. The possible causes of the hypercalcaemia which was not associated with a raised serum parathormone or affected by parathyroidectomy is discussed.