1. Department of Clinical Biochemistry, Immunology and Genetics; Statens Serum Institut; Artillerivej 5 2300 Copenhagen S Denmark
2. IGM - Bioorganic Chemistry, Faculty of Life Sciences; University of Copenhagen; Thorvaldsensvej 40 1871 Frederiksberg C Denmark
3. Present address: LEO Pharma A/S; Industriparken 55 2750 Ballerup Denmark
4. Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences; University of Copenhagen; Universitetsparken 2 2100 Copenhagen Ø Denmark