Featured Research

from universities, journals, and other organizations

Eye test for neurological diseases in livestock developed

Date:
October 25, 2010
Source:
Iowa State University
Summary:
Researchers have discovered that the eyes of sheep infected with scrapie return an intense, almost-white glow when they're hit with blue light. That finding suggests technologies can be developed to quickly and non-invasively test for transmissible spongiform encephalopathies, progressive and fatal neurological diseases such as mad cow disease.

The eyes of sheep infected with scrapie -- a neurological disorder similar to mad cow disease -- return an intense, almost-white glow when they're hit with blue excitation light, according to a research project led by Iowa State University's Jacob Petrich.

The findings suggest technologies and techniques can be developed to quickly and noninvasively test for transmissible spongiform encephalopathies, progressive and fatal neurological diseases such as mad cow disease in cattle and Creutzfeldt-Jakob disease in humans. Petrich, in fact, is working to develop a testing device.

The findings were published earlier this year in the journal Analytical Chemistry. The project was supported by a grant from the U.S. Department of Defense.

The research is the result of an accidental discovery while Petrich and his collaborators were developing a fluorescence spectroscopy device that's now used in slaughterhouses to test livestock carcasses for feces and possible E. coli contamination.

"One day we were testing the apparatus by shining light on the carcass and we saw the spinal cord glow -- it fluoresced," said Petrich, professor and chair of Iowa State's chemistry department. "We saw the spinal cord through the skin. The light was pretty intense. It was an amazing result."

That sparked some new thinking: Maybe fluorescence technology could be used to test animals for transmissible spongiform encephalopathies such as bovine spongiform encephalopathy -- what's often called mad cow disease. To reduce the risk of human exposure to the diseases, the brains and spinal cords of animals are removed during slaughter and processing. But there is no quick test to identify animals with the diseases.

And so Petrich and a team of researchers began studying the feasibility of a fluorescence test. The team included Ramkrishna Adhikary, an Iowa State graduate student in chemistry; Prasun Mukherjee, a former Iowa State graduate student and current post-doctoral associate in chemistry at the University of Pittsburgh; Govindarajan Krishnamoorthy, a former Iowa State post-doctoral research associate and current assistant professor of chemistry at the Indian Institute of Technology Guwahati; Robert Kunkle of the U.S. Department of Agriculture's National Animal Disease Center in Ames; Thomas Casey of the National Animal Disease Center; and Mark Rasmussen of the U.S. Food and Drug Administration's Center for Veterinary Medicine in Laurel, Md.

The researchers collected 140 eyeballs from 73 sheep. Thirty five of those sheep were infected with scrapie; 38 were not. The researchers took fluorescence readings from various parts of the eyes of all the sheep.

"The bottom line is the scrapie-positive retinas fluoresced like crazy," Petrich said. "And the scrapie-negative ones did not."

A previous study published in the journal Veterinary Pathology reported that the function and structure of retinas are altered in cattle infected with transmissible mink encephalopathy. Members of that study team included Iowa State researchers M. Heather West Greenlee, an associate professor of biomedical sciences in the College of Veterinary Medicine; Justin Greenlee, a collaborator assistant professor of biomedical sciences; and Juergen Richt, a collaborator associate professor of veterinary microbiology and preventive medicine.

Other studies have reported that lipofuscin, an intracellular fluorescent pigment, accumulates in the eyes of animals infected with the neurological diseases. Petrich and his team attribute the glow from scrapie-positive retinas to the elevated levels of lipofuscin.

Whatever the cause, Petrich said it's clear there are distinct differences in the fluorescence and spectroscopic signatures of retinas from sheep that were naturally infected with scrapie and those that were not. And so he and his research team think there's great promise for a diagnostic test based on that discovery.

That has Petrich starting to develop a device (he likes to call it a "gizmo") that could be used in meat plants to test the retinas of animals for signs of neurological diseases. He expects it will take several years to develop, build and test a useful device.

"What I like about this is it's really simple," Petrich said. "It's light in and light out."


Story Source:

The above story is based on materials provided by Iowa State University. Note: Materials may be edited for content and length.


Journal References:

  1. Ramkrishna Adhikary, Prasun Mukherjee, Govindarajan Krishnamoorthy, Robert A. Kunkle, Thomas A. Casey, Mark A. Rasmussen, Jacob W. Petrich. Fluorescence Spectroscopy of the Retina for Diagnosis of Transmissible Spongiform Encephalopathies. Analytical Chemistry, 2010; 82 (10): 4097 DOI: 10.1021/ac100179u
  2. J. D. Smith, J. J. Greenlee, A. N. Hamir, J. A. Richt, M. H.W. Greenlee. Retinal Function and Morphology Are Altered in Cattle Infected with the Prion Disease Transmissible Mink Encephalopathy. Veterinary Pathology, 2009; 46 (5): 810 DOI: 10.1354/vp.08-VP-0206-W-FL

Cite This Page:

Iowa State University. "Eye test for neurological diseases in livestock developed." ScienceDaily. ScienceDaily, 25 October 2010. <www.sciencedaily.com/releases/2010/10/101019152606.htm>.
Iowa State University. (2010, October 25). Eye test for neurological diseases in livestock developed. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2010/10/101019152606.htm
Iowa State University. "Eye test for neurological diseases in livestock developed." ScienceDaily. www.sciencedaily.com/releases/2010/10/101019152606.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins