Research
ANIMAL MODELS OF HUMAN DISEASES
Many disorders related to autoimmune diseases and genetic problems in people are similar to diseases in animals. This similarity of human and animal diseases allows veterinary researchers to better understand the role of genes in inherited diseases.
Two particular animal models have been the subject of long-term studies at the College of Veterinary Medicine. The gray collie dog, which has an inherited disorder called cyclic hematopoiesis, was discovered by a UT researcher to be a naturally-occurring animal model for the study of cyclic neutropenia, a life-threatening cyclical blood disorder in human beings. The effectiveness of potential treatments for the disease can be studied through blood samples taken from the affected dogs.
Another animal model of an inherited human disorder was discovered by a UT veterinary researcher. Studies of the disease Mucopolysaccharidosis I, commonly known as Hurler's Syndrome, have been conducted by UT researchers for several years with the assistance of the canine model. Hurler's disease, a disorder involving a deficiency of an enzyme needed to degrade certain metabolic by-products, can cause a variety of problems in humans, including bone abnormalities, visual impairments, deafness and mental deterioration. Children afflicted with the disease normally die before puberty.
These and other models are important in the study of a variety of diseases, both inherited and acquired. Treatments that may include bone marrow transplantation or the use of growth factors can be examined in these naturally occurring disease models.
Researchers at the College of Veterinary Medicine and Oak Ridge National Laboratories recently created a genetically altered mouse that can serve as an animal model for a fatal kidney disease affecting newborn children. Polycystic disease is an inherited disease that produces multiple cysts in the kidneys and liver of children and kills 95 percent of affected babies within a day of birth. The genetically altered mouse also develops polycystic disease similar to that in human beings. Until this discovery, researchers had been unable to identify any of the genes associated with the disease. By the end of 1992 researchers expect to locate the gene which is similar to the mouse gene and may cause the disease in human beings, allowing physicians to identify carriers of the inherited disease prior to pregnancy.
An area of long-term research at the college relates to blood platelet production. Many cancer patients die from bleeding caused by too few platelets. Developing a method to improve blood platelet production is critical. Current efforts are directed at cloning the gene for the factor, thrombopoietin, with a goal of producing sufficient quantities for patient therapy. Recent findings show that purified thrombopoietin will be useful for increasing platelet counts in cancer patients, in people undergoing bone marrow transplantation, those with AIDS or those with blood platelet disorders, such as chronic renal disease.