[1] MRC Clin Trials Unit, London WC2B 6NH, England
[2] Univ London Imperial Coll Sci Technol & Med, Chelsea & Westminster Hosp, Immunol Sect, London SW7 2AZ, England
[3] Chelsea & Westminster NHS Fdn, NHS Trust, London, England
[4] Mortimer Market Ctr, London, England
[5] Brighton & Sussex Univ Hosp, NHS Trust, Brighton, E Sussex, England
[6] St Marys Hosp, London, England
[7] St Thomas Hosp, London, England
[8] Barts & London NHS Trust, London, England
[9] Royal Bournemouth Hosp, Bournemouth, Dorset, England
[10] N Middlesex Univ Hosp, London, England
[11] Kings Coll Hosp London, London, England
[12] Kings Coll London, London, England
[13] St George Hosp, London, England