1. Department of Hematology and Oncology,1
2. Molecular Oncology, Biomedical Research Center, 2 and
3. Helix Research Institute, Chiba 292-0812,3
4. National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-0032, 4 and
5. Internal Medicine II, 5 Osaka University Medical School, Suita, Osaka 565-0871,
6. Pharmaceutical Research Laboratory, Kirin Brewery Co. Ltd., Takasaki, Gunma 370-1202, 6 Japan