[1] St Marys Hosp, Imperial Coll London, London W2 1NY, England
[2] Univ London Imperial Coll Sci & Technol, London, England
[3] Chelsea Westminster Hosp, Beta Cell Unit, London, England
[4] Royal Brompton Hosp, Clin Trials & Evaluat Unit, London, England
[5] Royal Brompton Hosp, IICT Scanning Unit, London, England
[6] St Marys Hosp, Dept Clin Biochem, London, England
[7] Royal Brompton Hosp, Dept Clin Biochem, London, England
[8] Univ London Imperial Coll Sci & Technol, Natl Heart & Lung Inst, London, England