[1] Newcastle Univ, Fac Med Sci, Inst Cellular Med, Newcastle Upon Tyne NE2 4HH, Tyne & Wear, England
[2] Newcastle Upon Tyne Hosp NHS Fdn Trust, Freeman Hosp, Ctr Cardiothorac, Newcastle Upon Tyne, Tyne & Wear, England
[3] Newcastle Upon Tyne Hosp NHS Fdn Trust, Dept Biochem, Newcastle Upon Tyne, Tyne & Wear, England
[4] Newcastle Upon Tyne Hosp NHS Fdn Trust, Freeman Hosp, Dept Reg Med Phys, Newcastle Upon Tyne, Tyne & Wear, England