MAD COW

            Who would of thought that eating hamburgers, steaks and drinking milk could produce an epidemic disease? These types of food are frequently eaten for their appealing tastes and nutritional values. The discovery of Creutzfeld Jakob Disease (CJD) has been a long and remarkable one. The cause of this disease is a mutated prion protein within the brain that can be either inherited or acquired. These mutations create sponge like holes that destroy the brain. As a result, the disorder gives both behavioural and muscular problems to infected individuals Experiments and discoveries to this disease have led to a further understanding of the diversity of proteins. In the 1960s, D. Carleton Gadjusek studied the behaviour of a native population in Papua, New Guinea. This population had been eating the brains of dead relatives and as a result, contracted a fatal neurodegenerative disease. When autopsies were taken from the population who died, they appeared to have a distinct pathology. The central brain tissue resembled a sponge with a lot of regions containing microscopic holes. The results of this disease appeared similar to persons affected with CJD. In 1968, D. Carleton Gadjusek injected an infected biopsy of brain with this disorder into a laboratory animal. As a result, the animal developed this disease. At this time, the biopsy was thought to contain a virus. At the University of California, Stanley Pruisner and colleagues proposed that agent for this disease was a prion. A prion is a protein version of viruses without the genetic information. Once the prion has entered the body, the normal proteins are mutated. The gene for the normal protein is expressed within normal brain tissue and encodes a protein that resides at the surface of nerve cells. The function is unknown. The mutated prion version of the protein accumulates within nerve cells, forming aggregates that kill cells. The normal protein is soluble in salt solution and is destroyed by protein-eating molecules, known as enzymes.