1. Ecole Polytechnique Fédérale de Lausanne, STI, LMIS4; Station 17 1005 Lausanne Switzerland
2. Faculty of Medicine; Department of Pathology and Immunology; CMU; Rue Michel-Servet 1 CH-1211 Geneva 4 Switzerland
3. Service de recherche chirurgicale; CHUV, Pavillon 4 1011 Lausanne Switzerland