1. Department of Internal Medicine, Circulatory and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
2. Department of Internal Medicine, Saigo Hospital, 29 Saigo-Tashiro, Misato, Higashi-Usuki, Miyazaki 883-1101, Japan
3. Department of Pathology, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
4. Department of Internal Medicine, Kirishima Memorial Hospital, 1-5-19 Fukushima, Kokubu, Kirishima 899-4322, Japan