1. Division of Rheumatology, Immunology and Allergy, Georgetown University Hospital, 3800 Reservoir Road, N.W., Hington, DC 20007, USA
2. Centre for Biomedical Sciences, Cardiff School of Health Sciences, University of Wales Institute-Cardiff, Western Avenue, Cardiff CF5 2YB, UK
3. Center for Wound Healing, Georgetown University Hospital, Washington, DC 20007, USA