1. Infectious Disease Research Program, Center for Bone Marrow Transplantation and Department of Pediatric Hematology/Oncology, Children's University Hospital, Muenster, Federal Republic of Germany
2. Clinical Pharmacokinetics Section, Coordinating Centre for Clinical Trials (KKS), University Hospital, Muenster, Federal Republic of Germany
3. Millers Children's Hospital, Long Beach, California
4. Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland