1.   Animal prion diseases are therefore brain diseases.

2.   Fetal stem cells could someday help treat everything from strokes to brain diseases, the promise of which will be politically irresistible, ac cording to Caplan.

3.   In mice, scientists have used the cells to cure paralysis, diabetes and brain disease.

4.   No cases of BSE --which has been linked to a human brain disease -- have been found in the U.S.