Role of the environment in osteoporosis.

By using a quantitative RNA-RNA solution hybridisation method, the average number of mdrl RNA transcripts per cell was measured in total nucleic acid extracts of leukaemic cells from patients with acute leukaemia. The results in different types of leukaemia were (number of patients with detectable mdrl RNA/total number of patients; median number of transcripts per cell in samples with detectable mdrl RNA); de novo untreated acute myelocytic leukaemia (AML): 20/44; 0.7, secondary acute myelocytic leukaemia: 8/13; 1.1, acute lymphocytic (ALL) and undifferentiated leukaemia: 5/14; 0.6, relapsed leukaemia: 7/15; 0.7. Forty-six patients with de novo untreated acute leukaemia (AML: n = 34, ALL: n = 12) were evaluable for response to induction chemotherapy. Twelve of 18 patients (67%) with detectable mdrl RNA levels achieved complete remission compared to 23 of 28 (82%) with undetectable levels (P = 0.40). The remission duration tended to be longer among patients with undetectable mdrl RNA (P = 0.08). Leukaemic cells were analysed