[1] Arkansas Childrens Hosp, Little Rock, AR 72202 USA
[2] Univ Arkansas Med Sci, Dept Pediat, Little Rock, AR 72205 USA
[3] Univ Arkansas Med Sci, Sect Pediat Clin Pharmacol & Toxicol, Little Rock, AR 72205 USA
[4] Univ Arkansas Med Sci, Ctr Appl Res & Evaluat, Little Rock, AR 72205 USA
[5] Louisiana State Univ, Sch Med, Dept Pediat, Clin Pharmacol Sect, Shreveport, LA USA
[6] Univ Missouri, Dept Pediat, Kansas City, MO 64110 USA
[7] Univ Missouri, Dept Pharmacol, Kansas City, MO 64110 USA
[8] Childrens Mercy Hosp, Sect Pediat Clin Pharmacol & Expt Therapeut, Kansas City, MO 64108 USA
[9] Univ Arkansas Med Sci, Dept Pharmacol & Toxicol, Little Rock, AR 72205 USA
[10] NICHHD, Bethesda, MD 20892 USA