The natural DNA repair protein, alkylguanine-DNA alkyltransferase (AGT) undoes the methylation or chlorethylation damage to the guanine of DNA done by alkylnitrosourea treatment. So a drug that depletes tumour cells of AGT should impair antitumour drug resistance. US researchers (Journal of Clinical Oncology 1998;16:3750–5) have shown that the drug 0⁶-benzylguanine (0⁶-BG) given to adults by intravenous infusion 18 hours before operation for malignant glioma reliably depleted glioma tissue of AGT. The next step will be to work out the maximum dose of antitumour drug that can safely be given with the 0⁶-BG.

It is perhaps not surprising that the families of adolescents with anorexia nervosa often exhibit disturbed functioning. But what is cause and what is effect? A study in the north west of England (British Journal of Psychiatry1999:174 :63–6) suggests that family difficulties are perceived as being greater by the adolescents and their doctors than by the parents and may be greater when the anorexia is less severe. These difficulties do not improve with clinical improvement. Where this puts the cause and …