[1] KAROLINSKA INST,DEPT MED BIOPHYS,EDRG,S-10401 STOCKHOLM 60,SWEDEN
[2] HUMBOLDT UNIV,BEREICH MED CHARITE,INST PATHOL,O-1040 BERLIN,GERMANY
[3] UNIV UPPSALA,DEPT ANAT,S-75105 UPPSALA,SWEDEN
[4] UNIV HOSP UPPSALA,DEPT OCCUPAT DERMATOL,UPPSALA,SWEDEN