Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers develop faster, more accurate test for mad cow disease

08.09.2003


As U.S. consumers seek reassurance that their hamburgers and steaks are free of deadly mad cow disease, researchers at the University of California-San Francisco say they may have found a promising solution. They’ve developed a faster, more reliable test for identifying the disease, possibly even in living cows. Current tests can only detect the disease after the cow dies.



The test was described today at the 226th national meeting of the American Chemical Society, the world’s largest scientific society.

Critics argue that the standard immunoassay tests used to identify the infectious prion proteins that cause mad cow disease are inadequate for large scale screening of cattle. The tests can produce false readings and may take a week to yield results. A better test is needed, they say.


The new test, which has already undergone animal studies, seems to fit the bill. Called the conformation-dependent immunoassay (CDI), it can detect prion proteins with 100 percent accuracy at much smaller levels than conventional tests and only takes about five hours to produce results, according to the UCSF researchers.

Like conventional tests, the new test is designed for detecting prions in the brain tissue of cows only upon autopsy. Unlike other tests, however, the new test also shows promise for detecting the proteins in muscle tissue and even blood while the animal is still alive. If so, it could be used to identify precisely which animals are infected before they show symptoms and could help end the current practice of slaughtering whole herds, the scientists say.

"This represents a new generation of prion tests," says project leader Dr. Jiri G. Safar, M.D., an associate adjunct professor at UCSF. "It is the most promising test to date for accurately detecting prion proteins," says Safar, a member of the school’s Institute of Neurodegenerative Diseases.

He says the test has been used in a field trial to check for signs of the disease in the brains of 11,000 slaughtered cows in Spain, the United Kingdom and Germany. Results were compared to those from standard immunoassays performed on the same animals. There were no discrepancies between the tests, he says.

"We had a perfect score. There were no false positives and no false negatives," says Safar. "We can’t afford incorrect conclusions, and we didn’t see that in our tests."

He says that the research group plans to use the test on an even larger scale among European cattle herds within the next year, checking them for signs of the disease upon autopsy. If further tests prove successful, he hopes it will eventually be used to evaluate dead cows in this country for mad cow disease, also known as bovine spongiform encephelopathy, or BSE.

Despite the fact that the CDI test is currently being done in dead cattle, Safar says the same test could eventually be used on live animals to determine the presence of prions. In lab tests, the researcher has used the CDI test to detect prions in the muscles of living mice.

The live test could eventually be used to screen patients for the human form of mad cow disease, known as variant Creutzfeldt-Jakob disease, which is thought to be acquired from eating infected beef. A tissue or blood test for live animals could be available in a year, says Safar. "We’re not quite there yet," he adds. "We still need to validate the effectiveness of CDI in live farm animals."

CDI has other advantages. It is automated, allowing larger numbers of animals to be screened in a short period. The test can detect up to eight different strains of prions, including those that cause scrapie in sheep and chronic wasting disease in deer.

With the recent detection of mad cow disease in neighboring Canada and the temporary ban on beef imported from that country, critics have stepped up their call for better testing. To date, there has never been a case of mad cow disease detected in the U.S. Given the flaws of current testing, however, some experts believe it could be just a matter of time.

Safar’s coauthor in this study is Dr. Stanley Prusiner, M.D., a professor of neurology and biochemistry at the university and director of its Institute for Neurodegenerative Diseases. Prusiner was the first to discover that abnormal prion proteins can cause disease, an accomplishment that won him the 1997 Nobel Prize in Physiology or Medicine.

CDI technology is now licensed to InPro Biotechnology, Inc., of San Francisco, a company founded by Prusiner.

Funding for this study was provided by grants from the National Institutes of Health, the United Kingdom’s Department for Environment, Food and Rural Affairs and private sources.


The paper on this research, ANYL 12, will be presented at 2:30 p.m. on Sunday, Sept. 7, at the Javits Convention Center, Room 1A01/1A02, during the "Diagnostic Assays for Prion Diseases" symposium.

Jiri G. Safar, M.D., is an associate adjunct professor at the University of California-San Francisco and a member of the school’s Institute of Neurodegenerative Disorders.

Stanley B. Prusiner, M.D., is a professor of neurology and biochemistry at UCSF and director of its Institute for Neurodegenerative Diseases. He is the recipient of the 1997 Nobel Prize in Physiology or Medicine.

Michael Bernstein | EurekAlert!
Further information:
http://www.acs.org/

More articles from Agricultural and Forestry Science:

nachricht Interaction with fungus containing N2-fixing endobacteria improves rice nitrogen nutrition
26.11.2019 | American Society of Plant Biologists

nachricht Strengthening regional development through old growth beech forests in Europe
20.11.2019 | Hochschule für nachhaltige Entwicklung Eberswalde

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Detailed insight into stressed cells

05.12.2019 | Life Sciences

State of 'hibernation' keeps haematopoietic stem cells young - Niches in the bone marrow protect from ageing

05.12.2019 | Life Sciences

First field measurements of laughing gas isotopes

05.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>