1. Department of Pathophysiology-Periodontal Science; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; 2-5-1 Shikata-cho Kita-ku Okayama 700-8525 Japan
2. Shinobe Clinic; 5-32-2 Akatsutsumi Setagaya-ku Tokyo 156-0044 Japan
3. Miyoshi Renal Clinic; 3-13-2 Miyoshi-cho Fuchu-shi Tokyo 183-0045 Japan
4. Machidakeisen Hospital; 2-1-47 Minami-machida Machida-shi Tokyo 194-0005 Japan
5. Department of Periodontics and Endodontics; Okayama University Hospital; 2-5-1 Shikata-cho Kita-ku Okayama 700-8558 Japan