[1] ROYAL POSTGRAD MED SCH, DEPT MED, GASTROENTEROL UNIT, LONDON W12 0HS, ENGLAND
[2] ROYAL POSTGRAD MED SCH, DEPT RADIOL, LONDON W12 0HS, ENGLAND
[3] ROYAL POSTGRAD MED SCH, DEPT PATHOL, LONDON W12 0HS, ENGLAND
[4] ROYAL POSTGRAD MED SCH, DEPT IMMUNOL, LONDON W12 0HS, ENGLAND