[1] INSERM Unité 21,
[2] Faculty of Medicine Paris Sud,undefined
[3] 16 avenue Paul Vaillant-Couturier,undefined
[4] F-94807 Villejuif,undefined
[5] France e-mail: maison@vjf.inserm.fr Tel.: 33 1 45 59 51 00,undefined
[6] Fax: 33 1 47 26 94 54,undefined
[7] CREDES,undefined
[8] Paris,undefined
[9] France,undefined