11.   Once it gets into a body, each prion protein latches onto a normal protein and transforms the good protein into a bad prion one.

12.   Prion diseases occur when a normal protein called a cellular prion misfolds into an abnormal shape that cannot be broken down by enzymes.

13.   Prions are normal proteins found on the surface of cells throughout the body.

14.   Prions, he said, are variants of normal proteins but are folded differently.

15.   Since the normal proteins are conjectured to form part of the surface of nerve cells, prion infections show up as brain degenerative diseases.

16.   That is, can a prion from a BSE-infected cow brain alter the normal human PrP protein, converting it into an agent of Creutzfeldt-Jakob?

17.   The abnormal prion is a version of the normal protein that has run amok.

18.   The new prion is far less vulnerable to degradation by enzymes than is the normal protein.

19.   The mutation alters beta amyloid, a fragment of a normal protein that is the major constituent of plaque.

20.   The University of Texas study was based on a comparison of mice which had normal protein FasL activity against mice that were bred to be deficient in this protein.