[1] Univ Newcastle, Fac Hlth & Med, Callaghan, NSW 2308, Australia
[2] Nepean Hosp, Kingswood, NSW, Australia
[3] Univ Sydney, Nepean Hosp, Sydney Med Sch, Kingswood, NSW, Australia
[4] Macquarie Univ, N Ryde, NSW, Australia
[5] Univ London Imperial Coll Sci Technol & Med, Ctr Pathol, London, England
[6] Guys Hosp, Dept Expt Immunobiol, London SE1 9RT, England