An agent that is smaller than a virus causes scrapie. It is either a protein called a prion or it is another substance closely associated with the prion protein. Scientists still have a lot to learn about the scrapie agent and exactly how it works.
Tissue valves are made with tissues from porcine (pig) heart valves or bovine (cow) cardiac tissue because they function like human heart valves. Once the tissue is removed from the animal, it is chemically treated to preserve the tissue and prevent immulogic reactions once it is placed in a patient.
The new cells and vessels eventually replace the scar tissue left behind by the heart attack. Because the gel is made from heart tissue taken from pigs, the damaged heart responds positively, creating an environment in which the heart is able to naturally rebuild itself, Christman said in a press release.Christman and her colleagues established the safety of the gel in large and small animal studies.ecause the gel is made from heart tissue taken from pigs, the damaged heart responds positively, creating an environment in which the heart is able to naturally rebuild itself, Christman said in a press release.