[1] Gulhane Mil Med Acad, Dept Med, Div Nephrol, Ankara, Turkey
[2] INC Ignacio Chavez, Dept Nephrol, Mexico City, DF, Mexico
[3] Selcuk Univ, Meram Sch Med, Dept Med, Div Nephrol, Konya, Turkey
[4] Univ Zulia, IVIC Zulia, Maracaibo 4011, Venezuela
[5] Univ Hosp, Serv Nefrol, Maracaibo, Venezuela
[6] Gr T Popa Univ Med & Pharm, CI PARHON Univ Hosp, Dialysis & Renal Transplant Ctr, Nephrol Clin, Iasi, Romania
[7] Univ Colorado, Div Renal Dis & Hypertens, Denver, CO 80202 USA