Wilms tumor in a patient with Prader-Willi syndrome.

The development of Wilms tumor in a patient with Prader-Willi syndrome prompted us to determine the parental origin of the genes implicated in both disorders because of the sex-specific parent-of-origin effects previously demonstrated for both conditions. A paternal chromosome 15q11-q13 deletion was demonstrated, but no changes were demonstrated in a limited analysis of chromosome 11p, which harbors two Wilms tumor suppressor genes, WT1 and WT2.

Chronopharmacology of methotrexate pharmacokinetics in childhood leukemia.

Survival has been shown to improve when maintenance therapy for acute lymphocytic leukemia in children is given at night rather during the day. We examined the possibility that diurnal variation in methotrexate pharmacokinetics may contribute to this improvement. In a crossover study, we determined the pharmacokinetics of intravenous methotrexate at 10:00 and 21:00 h in six children with standard or high-risk leukemia.

Preoperative chemotherapy for children with Wilms' tumor.

Five years ago, the use of preoperative chemotherapy for Wilms' tumor was adopted at this institution. Thirty children ranging in age from 5 months to 9 years had histologically confirmed Wilms' tumor (needle biopsy, n = 26; open biopsy, n = 4). Stage was determined by chest and abdominal computed tomography (CT) scan.

Diurnal variation of methotrexate disposition in children with acute leukaemia.

There is recent evidence that survival is improved when maintenance therapy for acute lymphocytic leukaemia in children is given at night. We have examined the possibility that diurnal variation in methotrexate pharmacokinetics may contribute to this improvement. In 6 children with leukaemia there was a significant fall in methotrexate plasma clearance at night (from 5.