[1] Univ Helsinki, Cent Hosp, Dept Med, Haartmansgatan 4, FIN-00290 Helsinki, Finland
[2] Minerva Fdn, Helsinki, Finland
[3] Sahlgrens Univ Hosp, Gothenburg, Sweden
[4] Cornell Univ, Weill Med Coll, New York, NY USA
[5] Ullevaal Univ Hosp, Oslo, Norway
[6] Univ Michigan, Ann Arbor, MI 48109 USA
[7] City Hosp, Birmingham, W Midlands, England
[8] Karolinska Univ Hosp, Stockholm, Sweden
[9] Glostrup Univ Hosp, Glostrup, Denmark
[10] Merck Res Labs Scandinavia, Stockholm, Sweden
[11] Viborg Hosp, Viborg, Denmark
[12] Umea Univ, Umea, Sweden
[13] Univ Helsinki, Cent Hosp, Helsinki, Finland
[14] Haukeland Hosp, N-5021 Bergen, Norway
[15] Univ Alabama Birmingham, Birmingham, AL USA
[16] Merck & Co Inc, Whitehouse Stn, NJ USA
[17] Nord Sch Publ Hlth, Gothenburg, Sweden