1. A/S Alfred Benzon, 29 Halmtorvet, DK-1700 Copenhagen, Denmark
2. Department of Pharmacy, University of Nottingham, Nottingham NG7 2RD
3. Department of Medical Physics, Queens Medical Centre, Nottingham
4. School of Pharmacy, Leicester Polytechnic, Leicester, UK
5. Department of Physiology/Pharmacology, Queens Medical Centre, University of Nottingham, Nottingham