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 Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country

nachricht New data unearths pesticide peril in beehives
21.04.2017 | Cornell University

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>