Petra Schulze-Westhoff

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The antileukaemic enzyme L-asparaginase is used to achieve the greatest possible reduction in blood levels of the amino acid asparagine, an essential factor for the growth of leukaemic blasts. There are two main sources of the enzyme, E. coli and Erwinia. Faced with increasing reports of treatment complications, we established a programme to monitor enzyme(More)
The enzyme asparaginase is an important element in the therapy of acute lymphoblastic leukaemia (ALL). The usual asparaginase dose as prescribed in the ALL-BFM-86/90 treatment protocol for the therapy of ALL is 10,000 IU/m2 at 3 d intervals and had been developed on the basis of the E. coli asparaginase preparation Crasnitin from the Bayer company. Using(More)
The aim of this study was to describe the pharmacokinetics of paracetamol (acetaminophen) and to get primary information on its metabolism after first indicated intravenous administration of paracetamol in children and adolescents undergoing major surgery. About 4 weeks after the last chemotherapy, seven children and adolescents (five osteosarcoma, two(More)
PURPOSE Most pediatric treatment protocols specify dose calculations for cytostatic drugs based on body-surface area (BSA). However, for children less than 1 year of age, calculation guidelines vary. Normally, reduced dosages are recommended with calculations based on body weight (BW). However, the optimal dose for infants should take age-dependent and(More)
The antitumor effect of etoposide (ETO) may be related to duration of exposure to a relatively low serum level while myelosuppression may be dependent on peak ETO serum levels. With regard to such therapeutic ranges, duration of exposure to predefined plasma ETO concentration ranges and the related AUC (expressed as percent of total AUC, pAUC) were used to(More)
Lack of sufficient cellular activity of asparagine synthetase (AS) in blast cells compared with normal tissue is thought to be the basis of the antileukaemic effect of L-asparaginase in acute lymphoblastic leukaemia (ALL). Although L-asparaginase is routinely used in ALL, its role and value in the treatment of acute myelogenous leukaemia (AML) is still(More)
The importance of the cellular pharmacokinetics of cytarabine triphosphate (ara-CTP) with regard to therapeutic efficacy is well established. In vitro and in vivo monitoring of pharmacokinetic parameters of leukemic blast cells were initiated in order to contribute to the pharmacological basis of optimal ara-C treatment strategies. Peripheral or bone marrow(More)
A rapid and sensitive capillary electrophoretic method for the determination of idarubicin and its metabolite idarubicinol in plasma has been developed and validated. Plasma is extracted by liquid-liquid extraction using chloroform. Idarubicin, idarubicinol and the internal standard daunorubicin can be separated in less than 5 min using a phosphate buffer(More)
A method for the determination of doxorubicin and its main metabolite doxorubicinol in human plasma is described. Two different sample preparation procedures are applied depending on the expected concentration: To monitor the peak plasma levels, 10 microL of plasma are deproteinated with acetonitrile. After centrifugation, the supernatant is directly(More)
The influence of two different E. coli asparaginase (ASP) preparations on fibrinolytic proteins in childhood ALL was recently reported, demonstrating a clearly significant association between ASP activity and haemostatic changes. Since the Bayer preparation is no longer available for treatment of large series of patients with ALL, the present study was(More)