[1] Duke Univ, Med Ctr, Durham, NC 27710 USA
[2] Univ Texas, Med Branch, Galveston, TX 77550 USA
[3] Univ N Carolina, Chapel Hill, NC 27515 USA
[4] Glaxo Wellcome Inc, Res Triangle Pk, NC 27709 USA
[5] St George Hosp, Sch Med, London, England
[6] Ctr Hosp, Nancy, France
[7] Ostra Univ, Sahlgrenska Hosp, Gothenburg, Sweden
[8] Northwestern Univ, Sch Med, Chicago, IL USA