[1] Packard Inst Co, Meriden, CT 06450 USA
[2] Boehringer Ingelheim Pharmaceut Inc, R&D Ctr, Ridgefield, CT 06877 USA
[3] Glaxo Wellcome Res & Dev Ltd, Med Res Ctr, Stevenage SG1 2NY, Herts, England
[4] Merck & Co Inc, Merck Sharp & Dohme Res Labs, Rahway, NJ 07065 USA
[5] Rhone Poulenc Rorer, Ctr Rech Vitry Alfortville, F-94403 Vitry Sur Seine, France
[6] Zeneca Pharmaceut, Macclesfield SK10 4TG, Cheshire, England
[7] CIS Bio Int, Res & New Technol, F-30203 Bagnols Ceze, France