New Test Detects Mad
Cow Protein In Blood
By John Roach
When mad cow disease occurred in England in 1986, it dealt a severe economic blow to the British beef industry. A scientist has developed a way to identify the presence of an abnormal protein in the blood of animals that gives rise to diseases such as mad cow disease. The technique might lead to a diagnostic test for such diseases.
"The big breakthrough is that to this point no one has been able to pick up the agent that causes the diseases in the blood of animals," said Mary Jo Schmerr, the Agriculture Research Service chemist who developed the laboratory assay.
The technique tags the abnormal proteins, called prions, as they are pushed through a small capillary. If the florescent tag binds to the proteins, it is an indicator that prions are present and the animal is infected. With further development, the assay could be packaged as a test kit and shipped around the country.
The tagging of prions also allows researchers to learn how the proteins move in the blood stream and at what stage the disease infects the brains of animals, where it causes the most damage.
Mad cow disease is the best known of these diseases, known as transmissible spongiform encephalopathies. When mad cow disease occurred in England in 1986 it dealt a severe economic blow to the British beef industry. Mad cow disease would have a similar devastating impact if detected in North America.
All sheep in North America are susceptible to scrapie, another form of transmissible spongiform encephalopathie.
"Further development of this assay may lead to a diagnostic test for this fatal disease agent in animals and humans. Such a diagnostic test would be an important tool for the control of these diseases," ARS administrator Floyd Horn said in a statement.
"This is the kind of tool needed to prevent that kind of disaster," said Schmerr. With a test kit, researchers could go in and find out what animals have the disease and "put a wall around the sick animals."
Other forms of transmissible spongiform encephalopathies include scrapie, which all sheep in North America are susceptible to. Elk and mule deer get the chronic wasting disease and mink are susceptible to yet another form.
Humans are susceptible to Creutzfeldt-Jakob disease and kuru. Creutzfeldt-Jakob disease is rare in the United States and kuru has never been seen outside New Guinea, according to the Agricultural Research Service.
Copyright 1999, Environmental News Network, All Rights Reserved