[+/-] Approved stem cell lines contaminated

As if we needed any more reasons to oppose the Bush administrations policy on stem cells:

All human embryonic stem cell lines approved for use in federally funded research are contaminated with a foreign molecule from mice that may make them risky for use in medical therapies, according to a study released Sunday.

Researchers at the UC San Diego and the Salk Institute for Biological Studies in La Jolla report that if the stem cells are transplanted into people, the cells could provoke an immune system attack that would wipe out their ability to deliver cures for diseases such as Parkinson's, Alzheimer's and diabetes.

The finding is a setback to the Bush administration's controversial policy of providing federal funding only for research using a limited number of embryonic stem cell lines already in existence.