[1] Papworth Hosp, Thorac Oncol Unit, Cambridge CB3 8RE, England
[2] Papworth Hosp, Physiol Resp Lab, Cambridge CB3 8RE, England
[3] Papworth Hosp, Dept Res & Dev, Cambridge CB3 8RE, England
[4] Papworth Hosp, Dept Cardiothorac Surg, Cambridge CB3 8RE, England