1.   All mammals have prion proteins whose structure varies by just a few building blocks called amino acids, Pringle said.

2.   But, Dormont reported, about half the mice did not have abnormal prion proteins in the parts of their brains examined by the researchers.

3.   Discovery of the prion proteins and their role in disease won the Nobel Prize only a year ago for Dr. Stanley B. Prusiner of UCSF.

4.   Dr. Manuelidis suspects these mice had brain damage because the mutated prion protein injured their brain cells, but that they did not in fact have scrapie.

5.   Dr. Rohwer, however, says that there is no reason to abandon science as we know it until there is proof that a prion protein can cause disease.

6.   First, the hypothesis holds, the prions touch normal prion proteins in the brain.

7.   He and his colleagues found that a normal form of the prion protein is encoded by a gene that is found in every cell of the body.

8.   He has shown that prion proteins exist in two forms -- one normal and one abnormal.

9.   It is marked by prion proteins that eventually turn the brain into a spongy mess.

10.   It is a prion protein, often called a bad protein, which is appropriate for a fatal disease with no cure.