1. From the University of Pittsburgh, Pittsburgh, Pa (M.M.B.); Duke University Medical Center, Durham, NC (R.H.J., R.M.C.); St Louis University Health Sciences Center, St Louis, Mo (R.G.B., B.R.C., M.J.K.); the Mayo Clinic, Rochester, Minn (T.A.O.); the National Heart, Lung, and Blood Institute, Bethesda, Md (D.F., G.S.); and the Cleveland Clinic, Cleveland, Ohio (E.H.B.).