1. From the Cornell Medical Center (V.P., P.M.O., J.N.B., R.B.D.), New York, New York; Haukeland Hospital (E.G.), Bergen, Norway; Copenhagen County University Hospital (K.W.), Glostrup, Denmark; St. John Hospital and Medical Center (J.G.), Detroit, Michigan; Veteran Affairs Medical Center (V.P.), Washington, DC; Helsinki University Central Hospital (M.S.N.), Helsinki, Finland; Sahlgrenska University Hospital-Östra (B.D.), Göteborg, Sweden.