[1] Chicago Ctr Clin Res, Chicago, IL USA
[2] Charing Cross Hosp, Natl Heart & Lung Inst, London, England
[3] Univ Milan, Milan, Italy
[4] Univ Birmingham, Birmingham, W Midlands, England
[5] Univ Glasgow, Glasgow, Lanark, Scotland
[6] Emory Univ, Sch Med, Atlanta, GA USA
[7] Univ Minnesota, Minneapolis, MN USA
[8] Natl Clin Res, Richmond, VA USA