1. Graduate School of Biomedical Sciences; Nagasaki University; 1-14 Bunkyo-machi Nagasaki 852-8521 Japan
2. Department of Molecular Microbiology and Immunology; Graduate School of Biomedical Sciences; Nagasaki University; 1-12-4 Sakamoto Nagasaki 852-8523 Japan
3. Department of Radioisotope Medicine, Atomic Bomb Disease Institute; Nagasaki University; 1-12-4 Sakamoto Nagasaki 852-8523 Japan