[1] Toho Univ, Ohashi Med Ctr, Div Nephrol, Tokyo 1538515, Japan
[2] Jikei Univ, Katsushika Med Ctr, Div Nephrol & Hypertens, Tokyo, Japan
[3] Musashino Red Cross Hosp, Dept Nephrol, Tokyo, Japan
[4] Kawakita Gen Hosp, Dialysis Ctr, Tokyo, Japan
[5] St Lukes Int Hosp, Div Internal Med, Dept Nephrol, Tokyo, Japan
[6] Tokyo Yamate Med Ctr, Dept Clin Engn, Tokyo, Japan
[7] Nagoya Daini Red Cross Hosp, Kidney Ctr, Nagoya, Aichi, Japan
[8] Wakayama Med Univ, Dept Internal Med, Div Nephrol, Wakayama, Japan
[9] Showa Univ, Fujigaoka Hosp, Dept Internal Med, Div Nephrol, Yokohama, Kanagawa 227, Japan
[10] Rinku Gen Hosp, Dept Nephrol, Osaka, Japan