1. Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, Centre for Self Organizing Molecular Systems, University of Leeds, LS2 9JT, UK, Department of Chemistry, Biophysical Chemistry, Umeå University, SE-901 87 Umeå, Sweden, and Department of Dermatology and Venereology, Lund University, Biomedical Center, SE-221 84, Lund, Sweden