[1] Univ Puerto Rico, Sch Med, Dept Pediat, San Juan, PR 00936 USA
[2] Baylor Coll Med, Houston, TX 77030 USA
[3] Boston Univ, Sch Med, Boston, MA 02118 USA
[4] NICHHD, Pediat Adolescent & Maternal AIDS Branch, Bethesda, MD 20892 USA
[5] New England Res Inst, Watertown, MA 02172 USA
[6] SUNY Hlth Sci Ctr, Brooklyn, NY 11203 USA
[7] Columbia Univ Coll Phys & Surg, New York, NY 10032 USA
[8] Univ Illinois, Chicago, IL USA
[9] NIDA, Rockville, MD USA
[10] NIAID, Div Aids, Bethesda, MD 20892 USA