[1] Univ Calif Los Angeles, Dept Pediat, Div Gastroenterol & Nutr, Mattel Childrens Hosp, 10833 LeConte Ave,Box 951752, Los Angeles, CA 90095 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, 10833 LeConte Ave,Box 951752, Los Angeles, CA 90095 USA
[3] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Med, Seoul, South Korea
[4] Univ Calif Los Angeles, David Geffen Sch Med, Div Pediat Surg, Dept Surg, Los Angeles, CA 90095 USA
[5] Univ Calif Los Angeles, David Geffen Sch Med, Dept Surg, Los Angeles, CA 90095 USA
[6] Vet Adm Greater Los Angeles Hlth Syst, Dept Surg, Los Angeles, CA USA