1. Department of Internal Medicine, Kyushu University Beppu Hospital, Beppu 874-0838, Japan
2. Department of Hematology and Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka 810-0065, Japan
3. Division of Basic Medical Science and Fundamental Nursing, Department of Nursing, Fukuoka Nursing College, Fukuoka 814-0193, Japan