1. Prion Digestion in the Alimentary Tract Nicholas Toney

2. Overview  Outline of the Digestive Tract  Dr. Manuelidis’s Claims  Experimental Procedure  Discussion

3. Ruminant Digestion

4. Digestion

5. Claim to Brain  Manuelidis’s Claim:  All detectable forms of PrP are digested in the gastro intestinal tract yet the invasive infectious particle (as many conventional viruses) is not destroyed

6. Transportation of prion protein across the intestinal mucosa of scrapie-susceptible and scrapie-resistant sheep  Experimental Methods and Goals  In Vivo GI inoculation  In Vitro GI digestion of infectious brain slurry

7. Western Blot

8. Infectivity of Scrapie Prion Protein (PrPSc) Following In vitro Digestion with Bovine Gastrointestinal Microbiota  Goals  Methodology  In Vitro Digestion  In Vivo determined level of infectivity

9. Discussion  Acid Resistance of Prions, digestion by microbiota  What limitations are there with the experimental methods?  Are the in-vitro digestion experiments a good model of digestion?  How do you reconcile the loss of detectable PrPres with the continued infectivity of brain slurry from Scrapie infected brain material?