[1] Chulalongkorn Univ, King Chulalongkorn Mem Hosp, Fac Med, Div Nephrol,Dept Med, Bangkok, Thailand
[2] Rangsit Univ, Lerdsin Hosp, Dept Med, Coll Med, Bangkok, Thailand
[3] St Elizabeths Med Ctr, Dept Med, Boston, MA USA
[4] Tufts Univ, Sch Med, Dept Med, Boston, MA 02111 USA