[1] Univ Alberta, Edmonton, AB T6G 2M7, Canada
[2] Univ Clin Vienna, Vienna, Austria
[3] Univ Alabama, Tuscaloosa, AL 35487 USA
[4] Charite Univ, Berlin, Germany
[5] McGill Univ, Montreal, PQ H3A 2T5, Canada
[6] Univ Chicago, Chicago, IL 60637 USA
[7] Acad Med Ctr, Amsterdam, Netherlands
[8] Schering Plough Res Inst, Kenilworth, NJ USA