[1] Univ Michigan Hlth Syst, Ann Arbor, MI USA
[2] McMaster Univ, Hamilton, ON, Canada
[3] Univ Catania, Dept Clin & Expt Med, Catania, Italy
[4] Boehringer Ingelheim Pharmaceut Inc, 90 E Ridge POB 368, Ridgefield, CT 06877 USA
[5] Univ Cattolica Sacro Cuore, Fdn Policlin A Gemelli, Rome, Italy