Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Test could improve detection of prion disease in humans

15.02.2005


A highly sensitive post-mortem test could help scientists more accurately determine if a person died of Creutzfeldt-Jakob disease (CJD), a human neurological disorder caused by the same class of infectious proteins that trigger mad cow disease, according to a new study supported in part by the National Institutes of Health (NIH). The finding opens the possibility that such testing might be refined in the future so it can be used to detect prion disease in living people and animals before the onset of symptoms.



The test, called conformation-dependent immunoassay (CDI), was originally developed to detect various forms of disease-causing proteins called prions in cows, sheep, deer and other animals. In the new study, researchers led by Jiri Safar, M.D., Bruce Miller, M.D., Michael Geschwind, M.D., Stephen DeArmond, M.D., and Nobel Laureate Stanley B. Prusiner, M.D., of the University of California, San Francisco, found that CDI not only identifies prions in human brain tissue but is faster and far more precise than the standard immunological detection methods, which only detect a small fraction of the infectious prions that may be in the brain.

The finding appears in the March 1, 2005 issue of the Proceedings of the National Academy of Sciences, www.pnas.org. Two components of the NIH, the National Institute of Neurological Disorders and Stroke (NINDS)* and the National Institute on Aging (NIA), supported the study. Additional support was provided by the John Douglas French Foundation for Alzheimer’s research, the McBean Foundation, and the Alzheimer’s Disease Research Center of California.


"The findings of this NIH-funded research are an important step forward for the detection of prions," said Michael Nunn, Ph.D., NINDS program director for prion research. "It has been very difficult to generate diagnostic tests in this area and these results are a significant improvement for the diagnosis of CJD in living people."

In the study, Prusiner and his colleagues extracted brain tissue from 28 people who had died of CJD. They tested these samples using CDI, which uses highly specific antibodies that bind to all disease-causing prions in the brain. They also used immunohistochemistry (IHC) to measure only the prion proteins that are resistant to an enzyme called protease. Protease-resistant prions are abnormal and usually infectious, meaning they can cause CJD and other neurodegenerative diseases. CDI detected abnormal prions in all of the sampled brain regions. In contrast, the researchers found that IHC detected abnormal prions in less than 25 percent of the sampled brain regions. The findings, according to the researchers, suggest that CDI could be used to establish or rule out the diagnosis of CJD with greater accuracy than IHC, particularly when a small number of samples are available. Prusiner and colleagues are exploring the possibility of using CDI in living tissue, like blood or muscle, to detect and diagnose prion diseases, such as CJD or bovine spongiform encephalopathy (BSE, mad cow disease) while people or animals are still alive.

"This research not only is an important advance for the detection and diagnosis of prion diseases, but, with the identification of protease-sensitive infectious prions, will lead to a better understanding of the underlying disease processes," said Andrew Monjan, Ph.D., Chief of the NIA’s Neurobiology of Aging Branch.

Prusiner received the 1997 Nobel Prize in physiology or medicine for his discovery of prions. Unlike viruses, bacteria, fungi, and parasites, prions contain no DNA or RNA. Instead, prions are an altered type of protein normally found within cells in humans and other organisms. These abnormal prion proteins appear to convert other, normal prions to an abnormal shape. Many scientists now believe this conversion process leads to several dementing diseases in humans, including CJD. Similar diseases in animals include bovine spongiform encephalopathy ("mad cow" disease) in cattle and scrapie in sheep. Abnormal, misfolded proteins contribute to other age-related neurological diseases such as Alzheimer’s and Parkinson’s diseases. According to Prusiner and his colleagues, CDI testing might eventually have a role in the diagnosis of other neurodegenerative diseases, including Alzheimer’s and Parkinson’s, in which normally shaped proteins are structurally altered.

Doug Dollemore | EurekAlert!
Further information:
http://www.nia.nih.gov

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>