[1] UCL, Haemostasis Res Unit, London, England
[2] Scottish Natl Blood Transfus Serv, Prod & Components R&D Grp, Edinburgh, Midlothian, Scotland
[3] Univ Cent Florida, Orlando, FL 32816 USA
[4] Royal Free Hosp, Haemophilia Ctr, London NW3 2QG, England