[1] Univ Bristol, Bristol Royal Infirm, Div Med, Bristol BS2 8HW, Avon, England
[2] Univ London Queen Mary & Westfield Coll, London E1 4NS, England
[3] Kings Coll London, London SE5 9RS, England
[4] Rush Presbyterian St Lukes Med Ctr, Chicago, IL 60612 USA
[5] Univ Edinburgh, Edinburgh EH8 9BE, Midlothian, Scotland
[6] Merck Sharp & Dohme Ltd, Res Labs, Harlow CM20 2QR, Essex, England