[1] Tokyo Univ Hosp, Dept Med, Tokyo 113, Japan
[2] Univ Occupat & Environm Hlth, Dept Orthoped Surg, Kitakyushu, Fukuoka 807, Japan
[3] Osaka City Univ, Grad Sch Med, Dept Metab Endocrinol & Mol Med, Osaka 558, Japan
[4] Univ Tokushima, Grad Sch Med Sci, Dept Med & Bioregulatory Sci, Tokushima 770, Japan