Transmissible spongiform encephalopathies and tissue cell culture

The discovery of prion proteins and the diseases which are associated with them still present scientists and clinicians with a number of problems. There are clearly risks with the use of living cells and materials of animal origin to produce therapeutic compounds with respect to the transmission of prion protein. However the medical benefit many of these compounds has to be weighed against this. It is clear a number of groups are continuing to unravel the highly complex relationships of prion biology and pathology and it is only when this is clearly established that the community can decide on these issues. Until this time the scientific community must rely on the best research available and provide guidance from this. This revised version was published online in August 2006 with corrections to the Cover Date.