1. Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
2. Laboratory of Radiopharmacy, Universiteit Gent, Harelbekestraat 72, B-9000 Ghent, Belgium
3. Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium