[1] Univ Nottingham, Queens Med Ctr, Div Ophthalmol & Visual Sci, Nottingham NG7 2UH, England
[2] St Thomas Hosp, Dept Infect & Immunol, London, England
[3] Newcastle Univ, Bioinformat Support Unit, Inst Cell & Mol Biosci, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[4] Kings Coll London, Mol Toxicol Grp, Dept Forens Sci & Drug Monitoring, London WC2R 2LS, England