MAd Cow

[catbirdseat]

I'm way out of my field here, but I would suspect that handling the raw meat could be a transmission mode.

I don't think so. Proteins don't cross intact skin at all. If meat handlers did not use gloves and did not wash their hands, they could possibly ingest some by putting hands in their mouths, but this route would be less likely to cause infection than actually consuming the meat.

 

In answer to JayB's question this experiment has been done: "Using in vitro conversion of radiolabeled PrPC to protease-resistant PrP by incubation with PrPSc preparations of either strain, Bessen et al. (1995) could confer the respective properties to the newly converted protease-resistant PrP." Biology and Pathology of Prion Diseases: Hypothesis on the Nature of the Infectious Agent

[Peter_Puget]

Cow came from Canada.

 

Link

[Dan_Harris]

WASHINGTON — The Holstein infected with mad cow disease in Washington state was imported into the United States from Canada about two years ago, federal investigators tentatively concluded Saturday.

 

Dr. Ron DeHaven, chief veterinarian for the Agriculture Department (search), said Canadian officials have provided records that indicate the animal was one of a herd of 74 cattle that were shipped from Alberta, Canada, into this country at Eastport, Idaho.

 

"These animals were all dairy cattle and entered the U.S. only about two or two-and-a-half years ago, so most of them are still likely alive," DeHaven said.

 

He emphasized that just because the sick cow was a member of that herd, it does not mean that all 74 animals are infected.

 

Based on the Canadian records, the cow was 6-years-old — older than U.S. officials had thought, DeHaven said. U.S. papers on the cow said she was 4- or 4-years-old. . . .

 

If U.S. officials determine the sick cow was imported from Canada and its offspring has been destroyed, . . .

 

But investigators have not yet found where the sick cow was born.

Did anyone else find the disparity between the beginning of the article and ending interesting? Start says cow was from Canada. End says if it was from Canada. My paper this morning says it is suspected the cow was from Canada but records, both feed and sales of animals, are fuzzy and it will take some time to unravel.

[murraysovereign]

If it's anything like the 9/11 highjackers who supposedly came through Canada, it will eventually be determined this was a Saudi Arabian cow that entered the US on a direct flight from Germany. In order to prevent repeat occurrences, the United States will invade Iraq.

[JayB]

I'm way out of my field here, but I would suspect that handling the raw meat could be a transmission mode.

I don't think so. Proteins don't cross intact skin at all. If meat handlers did not use gloves and did not wash their hands, they could possibly ingest some by putting hands in their mouths, but this route would be less likely to cause infection than actually consuming the meat.

 

In answer to JayB's question this experiment has been done: "Using in vitro conversion of radiolabeled PrPC to protease-resistant PrP by incubation with PrPSc preparations of either strain, Bessen et al. (1995) could confer the respective properties to the newly converted protease-resistant PrP." Biology and Pathology of Prion Diseases: Hypothesis on the Nature of the Infectious Agent

 

From the Same Site...

 

"A disease-specific protein can be identified in the infected brain and other organs. This protein, the "scrapie prion protein", PrPSc in short (also called "BSE prion protein" PrPBSE in the case of BSE), is derived from the normal form of the prion protein, PrPC, occurring in the normal body.

 

The two proteins, the disease-specific PrPSc and the normal PrPC, differ in their spatial structures and the fact that PrPSc is resistant to destruction by digestive enzymes (proteins which digest food in the human stomach), whereas PrPC is completely destroyed when treated with digestive enzymes.

 

As a result of many studies it has been possible for scientists to come to the conclusion that PrPSc is a component of the pathogen of the prion diseases. It is even speculated that PrPSc represents the complete pathogen. According to this theory, an infection brought about by the penetrating PrPSc causes PrPC to be converted into PrPSc. The newly formed PrPSc can now, for its part, bring about the conversion of more PrPC into PrPSc. This leads to the disastrous chain reaction where the PrPSc production increases exponentially and the brain is damaged irrevocably. Notably, the increase in PrPSc during the course of the disease correlates with the increase in infectivity. "

 

This hardly constitutes an exhaustive search of the literature, but in the reading that I have done I have yet to see a study in which someone isolates ultrapure prion protein that's in the conformation associated with the disease, administers it orally, and witnesses the disease in the animal and radioloabelled protein in the appropriate cells in the brain. What I have seen are studies in which researchers generate infections by administering cell lysates from infected tissue, but this sort of experiment does not constitute credible proof that the protein alone is sufficient to transmit the disease. It could be that the protein surrounds and protects fragment of DNA or RNA that actually serves as the infectious agent, or works with the protein in the manner of an extremely primitive virus, etc, etc, etc

 

The studies like the one posted above where prion proteins turn their normal counterparts to the conformation associated with the disease in vitro are certainly interesting, but are not sufficient grounds to claim that the naked proteins are capable of inducing the disease in-vivo IMO.

[murraysovereign]

Looks like BSE isn't the only lethal brain-eating poison Canada is exporting to the United States. As your neighbour, I strongly recommend you institute some strict customs regulations to block the importation of this

 

Oh, the humanity...

[JayB]

Have you seen any papers where they administer purified radioloabelled prion proteins to test animals orally and then find both the intact protein localized in brain tissue as well as the plaques of aberrant prion protein? Or where they administered unlabelled protein and detected it in tissue sections with F.I.S.H. or some other means? I haven't come across any papers like that that have would support the claim that prions can move from hamburger to brain - but I would think that there must be such papers out there if this transmission model has been universally accepted.

 

I'm also curious about the incidence of CWD in wild deer and sheep, as they surely are not grilling each other up in the wilderness or engaging in the ritual cannibalism that spread Kuru. The only model of transmission that would jive with this model is if the wild animals were getting their hands on tainted-feed destined for cattle and the species-barrier was too low to prevent transmission from cattle remains to Deer and Elk. I suppose it could pass from mother to offspring (?)but you'd think that natural selection would put a damper on this mode of transmission pretty quickly.

 

Jay - people aren't routinely eating cattle feed from what I understand. If you think BSE can't survive digestion how is it that the consumption of diseased beef (deer or elk) and CJD are linked?

 

I was just saying that if it was necessary to ingest diseased tissue to contract transmissible spongiform encephalopathies, then it's hard to see how herbivores such as deer would contract the disease unless they became cannibalistic omnivores and started eating each other's nervous tissue, or hopped a fence and ate some infected cattle feed on a nearby ranch. So far as I know, the use of rendered remains in livestock feed was outlawed in 1997, so the continued transmission of the disease in the wild - in the absence of tainted feed - presents a problem unless protein from the dead deer carcases alone serves as a viable means of transmitting the disease, as Murray suggested. When cattle were no longer exposed to feed with rendered remains in it, the incidence of the disease in England declined dramatically, and if transmission is relatively rare between animals that live in constant proximity to one another in a closed space, it stands to reason that transmission between animals in the wild would be at least an order of magnitude or two lower.

 

The disease may be orally transmissible, but if the disease is transmitted by a bare protein via ingestion then that protein would have to overcome all of the hurdles that I outlined above on its journey from the mouth to the brain. There's some evidence to support that conclusion out there, but based on the papers I've seen it's far from conclusive at this point.

[EWolfe]

So, a couple of cows are chewing their cud in a field, one cow turns to the other and says:

"Hey, cow! Did you hear about that mad cow disease that's going around?"

The other cow looks up and says:

"Why would I care, you stupid bovine? I'm a tree!"

 

[Fairweather]

Looks like BSE isn't the only lethal brain-eating poison Canada is exporting to the United States. As your neighbour, I strongly recommend you institute some strict customs regulations to block the importation of this

 

Oh, the humanity...

 

NOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!

[arlen]

If it's anything like the 9/11 highjackers who supposedly came through Canada, it will eventually be determined this was a Saudi Arabian cow that entered the US on a direct flight from Germany. In order to prevent repeat occurrences, the United States will invade Iraq.

 

...and cancel a few more flights out of France. Take that, Osama!

[arlen]

Jay - people aren't routinely eating cattle feed from what I understand. If you think BSE can't survive digestion how is it that the consumption of diseased beef (deer or elk) and CJD are linked?

 

Correct me if I'm wrong, but there's no link, only reasonable speculation. There've been several cases of CWD in wild deer in Wisconsin (where there are large cattle and deer herds) but no BSE. They're doing a lot of science on both deer and cattle and so far there's no transmission between cattle and deer, or between cattle or deer and humans. The high occurance of new variant CJD in England seems very compelling, but all I've seen says no actual link has been nailed down.

[olyclimber]

What tastes tastier to a cow than the meat of a cow infected with MCD? Nuttin? Well, it sounds like our US meat producers have their feed situation take care of! What? They already feed 'downers' to the rest of the cows? There goes another business idea down the drain....

[catbirdseat]

What tastes tastier to a cow than the meat of a cow infected with MCD? Nuttin? Well, it sounds like our US meat producers have their feed situation take care of! What? They already feed 'downers' to the rest of the cows? There goes another business idea down the drain....

Here's the latest research which suggests that BSE is more infective in humans than was previously thought. Some animals may be asymptomatic carriers.

[allthumbs]

salt causes erectile disorder, and Henny Penny says the sky is falling

[lummox]

salt causes erectile disorder

that is a bummer for ya.

[Dru]

Have you seen any papers where they administer purified radioloabelled prion proteins to test animals orally and then find both the intact protein localized in brain tissue as well as the plaques of aberrant prion protein? Or where they administered unlabelled protein and detected it in tissue sections with F.I.S.H. or some other means? I haven't come across any papers like that that have would support the claim that prions can move from hamburger to brain - but I would think that there must be such papers out there if this transmission model has been universally accepted.

 

I'm also curious about the incidence of CWD in wild deer and sheep, as they surely are not grilling each other up in the wilderness or engaging in the ritual cannibalism that spread Kuru. The only model of transmission that would jive with this model is if the wild animals were getting their hands on tainted-feed destined for cattle and the species-barrier was too low to prevent transmission from cattle remains to Deer and Elk. I suppose it could pass from mother to offspring (?)but you'd think that natural selection would put a damper on this mode of transmission pretty quickly.

 

Jay - people aren't routinely eating cattle feed from what I understand. If you think BSE can't survive digestion how is it that the consumption of diseased beef (deer or elk) and CJD are linked?

 

I was just saying that if it was necessary to ingest diseased tissue to contract transmissible spongiform encephalopathies, then it's hard to see how herbivores such as deer would contract the disease unless they became cannibalistic omnivores and started eating each other's nervous tissue, or hopped a fence and ate some infected cattle feed on a nearby ranch. So far as I know, the use of rendered remains in livestock feed was outlawed in 1997, so the continued transmission of the disease in the wild - in the absence of tainted feed - presents a problem unless protein from the dead deer carcases alone serves as a viable means of transmitting the disease, as Murray suggested. When cattle were no longer exposed to feed with rendered remains in it, the incidence of the disease in England declined dramatically, and if transmission is relatively rare between animals that live in constant proximity to one another in a closed space, it stands to reason that transmission between animals in the wild would be at least an order of magnitude or two lower.

 

The disease may be orally transmissible, but if the disease is transmitted by a bare protein via ingestion then that protein would have to overcome all of the hurdles that I outlined above on its journey from the mouth to the brain. There's some evidence to support that conclusion out there, but based on the papers I've seen it's far from conclusive at this point.

 

apparently elk like to rub noses and swap saliva (and eat each others feces) Chronic Wasting Disease is transmitted that way

 

filthy beasts! i thought only humans were supposed too be perverts

[chucK]

Investigative report on KIRO TV that finds MANY more CJD (human variant of BSE) than have been otherwise reported. Many misclassified as strokes and Alzheimers. The report looked at WA and found many more cases than have been thought. It states that WA has a higher incidence than everywhere else, but I think that might not be correct because everywhere else has not undergone this upgraded scrutiny. What probably is true is that CJD is much more prevalent than the doctors and govt. are telling us.

 

link

[To_The_Top]

I'm sure its the cattle lobby too...they are very powerful.

[catbirdseat]

I heard they are only testing downer cattle for BSE and yet it turns out the Mabton cow was NOT a downer. The whole testing program is quite dubious.

[jon]

I wish I could figure out a quick BSE test, I would be rich.

[chucK]

Combination cow-slaughtering and dressing and MRI machine!

[archenemy]

I wish I could figure out a quick BSE test, I would be rich.

 

There already is one, it is used in Europe. We just don't do it here due to "cost" (which I don't believe). I have had to work with the FDA before to get medical devices approved, and although I don't know if that is what the cattle-testing gang has to go through, its got to be a pain in the ass.

[catbirdseat]

So you've no doubt heard that there was a cow that was "suspicious". They used a new "high sensitivity" test which caught the case. I presume this is a biochemical test for the actual variant prion protein. They sent it off for the "definitive" testing, which is the microscopic examination of the brain tissue for the characteristic holes in the neurons. This was done twice and in both cases was negative. Reassuring until you realize that infected individuals can be asymptomatic. This cow may have had very early stage disease. There have been documented cases of humans in whom the prion protein has been isolated from nasal surfaces.

 

I'm reading a book called Brain Trust which suggests that tens to hundreds of thousands of people in the US may be dying of BSE which is misdiagnosed as Alzheimer's Disease. Why is it that the incidence of Alzheimer's disease has increased dramatically since 1979?

 

I'll likely write more about this after I finish the book. Meanwhile, enjoy your beef.

[Sandbag]

 

Everyone should stop listening and reading and watching anything that FOX News produces. Period.

 

See here: http://www.outfoxed.org/

[catbirdseat]

Just for kicks you should go and google [cattle mutilation prion] and see what you get. The UFO folks always liked to think that cattle mutilation was being performed by aliens. Well, guess again. The government was interested in prion diseases because of its possible utility in biowarfare. They infected a huge variety of different species at Patuxent, MA in the early 1960's and the prion disease escaped into wildlife becoming known as "chronic wasting disease". Apparently, the government has been financing a covert prion testing program for the past 40 years. What is amazing is that no one has ever shot down one of the helicopters used in the illegal testing. I'll bet they've been shot AT.