[1] Johns Hopkins Univ, Sch Med, Baltimore, MD 21218 USA
[2] Massachusetts Gen Hosp, Boston, MA 02114 USA
[3] Univ Alberta, Edmonton, AB, Canada
[4] Univ Basel, Basel, Switzerland
[5] Univ Calif Los Angeles, Los Angeles, CA USA
[6] Catholic Univ Louvain, Sch Med, Brussels, Belgium
[7] Univ Pittsburgh, Pittsburgh, PA USA
[8] Univ Calif Los Angeles, David Geffen Sch Med, Los Angeles, CA USA
[9] Vanderbilt Univ, Nashville, TN USA
[10] Univ Leicester, Leicester, Leics, England
[11] Hlth Sci Ctr, Winnipeg, MB, Canada
[12] Hop Europeen Georges Pompidou, Paris, France
[13] Univ Helsinki, Helsinki, Finland
[14] Univ Iowa, Iowa City, IA USA
[15] Yale Univ, New Haven, CT USA
[16] Univ Texas, Houston, TX USA
[17] St Pauls Hosp, Vancouver, BC V6Z 1Y6, Canada
[18] Nagoya City Univ, Nagoya, Aichi, Japan
[19] Univ N Carolina, Chapel Hill, NC USA
[20] Univ Vienna, Vienna, Austria
[21] Univ Barcelona, Barcelona, Spain
[22] Cornell Med Ctr, New York, NY USA
[23] Natl Hosp, Oslo, Norway
[24] Rockyview Gen Hosp, Calgary, AB, Canada