Posted on 01/20/2005 4:42:19 PM PST by M. Espinola
ORONTO, Jan 20th, 2005 (The Canadian Press via COMTEX) -- The human food chain may not be as well protected from BSE as everyone hopes, scientists admitted Thursday in the wake of publication of new research showing the malformed proteins that cause the brain-wasting disease can be found in more tissues than previously thought.
Experts admit the findings are worrisome, but note the additional risk, if confirmed, may still be low because it is believed there is very little bovine spongiform encephalopathy - mad cow disease - in current cattle herds.
"I don't want to provoke hysteria here," senior author Dr. Adriano Aguzzi said in an interview from Zurich, where he is a researcher at the institute of neuropathology at University Hospital.
"The bad news is that the prions are likely to distribute in the body more broadly than we would have thought possible - and that's obviously bad news.
"But ... the good news is there is very little BSE left in Europe and there has always been very little BSE in North America."
A prion expert at the University of Toronto said if the findings are confirmed in cows - the research was done in mice - current regulations aimed at keeping high-risk meats from entering the food chain will have to be reconsidered.
"The specified risk material ban is to protect us from being exposed to BSE prions. If there's a way for BSE prions to circumvent this barrier to actually propagate in muscle (meat), then we're in trouble again," Dr. Neil Cashman said.
"I think it's a clear threat and it deserves ample consideration."
But the director of animal health laboratory services at the Canadian Food Inspection Agency said it is too soon to conclude the risk of acquiring variant Creutzfeld-Jakob disease - the human form of BSE - from eating beef is higher than previously thought.
"Are we concerned about it? Too early to tell," Dr. Shane Renwick said.
"We certainly are very interested in it. And I think there'll be a lot of interest around the world in this research. But it is preliminary in nature."
Renwick defended the current regulations, built around ensuring that tissues considered high risk - brains and spinal cord, gut and lymphatic tissue - don't enter the food chain.
"Given what we know I think the firewall is excellent," he said from Ottawa.
The research was published online Thursday by the journal Science.
Researchers from Zurich, the Institute of Neurology in London and Yale University School of Medicine set out to see if there was a link between inflammation and prions.
Their theory was that inflammation might provoke migration to and propagation of prions in tissues where they are not normally found.
The scientists injected prions into mice suffering from one of five different conditions causing inflammation in the kidney, pancreas or liver. (Those organs, normally thought to be prion-free, were randomly selected.) They then looked to see if they could detect the misfolded proteins in those organs.
They did, in all of the mice.
"Three organs, five different inflammatory conditions - this makes a very tight case," Aguzzi said.
"I have hardly any doubt that these findings can be extrapolated to additional organs as well."
Cashman pointed out a caveat, calling it "a ray of hope." The prions used in the experiment were the type that cause scrapie, the brain-wasting disease that afflicts sheep.
Scrapie is believed to have jumped the species barrier to cows - triggering BSE - but has not been found to be a direct risk to humans.
The scrapie prion and the one that cause BSE don't work exactly the same way, Cashman noted. But it's crucial that additional research is done to see if what happens in mice will also happen in cattle.
"Clearly the experiments have to be done with inflamed bovine muscle," he said.
Aguzzi agreed, but said he cannot work with such large animals in the laboratories in Zurich. Instead, his team is testing the thesis in sheep.
"I predict that they (the results) are probably very well extrapolated to sheep," he said.
"I don't know how much of this will hold true for the cow and this needs experimentation. It could be either way."
In the interval, authorities should stringently enforce regulations aimed at ensuring sick cows don't make it into the food chain, Aguzzi said. "If sick cows were reliably not entering the human food chain, then there would be no reason to worry because of our new findings."
If Mad Cow disease isn't a threat to this country, then how do you explain Barbara Boxer?
The prions used in the experiment were the type that cause scrapie, the brain-wasting disease that afflicts sheep.
Scrapie can also occur in goats.
Scrapie is believed to have jumped the species barrier to cows - triggering BSE - but has not been found to be a direct risk to humans.
This is one of several ideas on how BSE started, but there is not yet enough science to make this a definitive statement.
Bump
We'd be lucky to know diddly about prion disease.
It would be terrible if it turned out that we all have this in our bodies lying dormant and waiting for some bad infection to trigger it.
!!!
that's mad N.O.W. disease.
now virgil, none of us is getting out of this life alive.
I really wish I had not read this.
"Beavers and ducks!"
Gerry Parsky.
And quit allowing Bill Jones to run for office. That's Step One in the 12 Step program.
Here's what was in the NY Times.
January 20, 2005 Rogue Proteins Found in Unexpected Organs By THE ASSOCIATED PRESS
Filed at 3:28 p.m. ET
WASHINGTON (AP) -- Rogue proteins like those that cause mad cow disease -- found previously only in brain, nerve and lymph tissues -- have now been located in the liver, kidney and pancreas in a study of rodents.
While the discovery raises the possibility that similar proteins could move into unanticipated parts of farm animals that have similar diseases, it is not a reason for alarm, says researcher Adriano Aguzzi of the University Hospital of Zurich, Switzerland.
But, he adds, ``There is reason to reappraise critically the way regulations that are already in place'' are enforced.
Sick animals such as sheep and cows should not enter the human food chain, Aguzzi, the lead researcher in the study, said in a telephone interview.
``I think what is probably worth doing is to recheck whether all these regulations are implemented properly,'' he said. ``But, I think this is nothing that should provoke a wave of panic.''
Rogue proteins called prions are blamed for several brain-wasting diseases, including mad cow disease, scrapie in sheep and variant Creutzfeldt-Jakob disease in humans.
These proteins had only been found in the brains, spinal cord and lymph tissues of infected people and animals. But Aguzzi's report, being published online Thursday by the journal Science, indicates that in at least some cases they can move to other parts of the body.
Inflammation, characterized by swelling, redness and pain, occurs in a number of diseases, such as hepatitis, which affects the liver.
``I think it certainly raises questions as to the current classification of risk organs, which essentially says the brain and lymphatic tissue is at risk, whereas everything else is rather safe,'' Aguzzi said. ``So, I think that in the case of an inflammatory condition, I think that is no longer valid.''
The finding ``reinforces that you never say never,'' said Dr. William Hueston, director of the University of Minnesota's Center for Animal Health and Food Safety.
Hueston, who was not part of Aguzzi's research team, agreed that the finding isn't cause for alarm, saying it reinforces the reasons for inspecting animals in the food chain.
Dr. Robert B. Petersen, a professor of neuropathology at Case Western Reserve University in Cleveland, agreed that any risk is low since screening procedures would identify infected animals.
In addition, considering the low incidence of prion diseases, ``it is unlikely that you would find an animal with chronic viral or bacterial infection and prion infection simultaneously,'' said Peterson, who was not involved in Aguzzi's research.
Jim Rogers, of the Agriculture Department's Animal and Plant Health Inspection Service, said the agency already targets high-risk animals and won't need to change its procedures.
In the study, Aguzzi's team, which included researchers at the Institute of Neurology in London and at Yale University, raised mice that had chronic inflammatory disease of the liver, pancreas or kidney.
These mice were injected with prions from sheep suffering from the disease scrapie, and when the mice were studied the researchers found at least some of the prions had accumulated in the diseased organs. Aguzzi said he is planning similar experiments on sheep.
Mad cow disease is formally known as bovine spongiform encephalopathy, or BSE. The brain-destroying illness raised great concern when a form of it passed to humans in England in the 1980s and 1990s. It has killed more than 140 people in Britain and at least 10 others in other parts of the world. The only U.S. death, last June, was a woman who had been infected in England years earlier.
When BSE is passed into humans it is known as variant Creutzfeldt-Jakob disease. There is also a brain-wasting disease called sporadic Creutzfeldt-Jakob disease that occurs in humans, but is not caused by BSE. Both, however, are caused by prions, proteins that fold incorrectly.
Only a single case of mad cow disease has been reported in the United States, in Washington state, prompting federal regulators to ban certain portions of cows from human food and to tighten rules on use of sick animals.
The research was supported by the Swiss Federal Office for Education and Science, Swiss National Science Foundation, Swiss National Center for Competence in Research, University of Zurich, a grant from the Catello family, the Association for the Promotion of the Academic New Generation, the Medical Research Council of the United Kingdom and the U.S. National Institutes of Health.
Science: http://www.sciencemag.org
He' accountable for her re-election. He deflected all CAGOP fundraising to Bush leaving Jones high and dry.
And quit allowing Bill Jones to run for office. That's Step One in the 12 Step program.
LOL! Parsky PREFERRED Bill Jones over Howard Kaloogian. Once nominated, Parsky abandoned Jones, who took the dive as predicted.
RINOs.
What credence do you give to the hypothetical role of organophosphates as an alternative to prions as the cause of Mad Cow?
How do you know that some dogs haven't died from this disease? Do people have autopsies performed on their dogs?
I don't, but I have never heard of a case and dogs get more veterenary care than do cows.
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