Well, its been quite a while since “Mad Cow Disease” was first recognized. I also belive that several hundred people (mostly in the UK) have died from the human form of this disease. Now, I hear that wild deer and elk in the northern USA and Canada, have been found to harbor a similar type disease. So, for you experts:
-do scientists unanamously accept prions as the cause of these diseases?
-can these prions be destroyed?
-are there 100% reliable methods for keeping this disease from the human population?
-once infected with a prion, is it inevitable that the host will die?
Finally, could prions be used for germ warfare?
I don’t know a lot. I do know Creutzfeldt Jakob Disease has been around for several years, yet only recently linked in the media to Mad Cow Disease
These are both medical sites,much of the available on-line information seems rather “fringy” to me. Many are animal rights or vegan sites, who may not be totally objective.
no cite.
I asked my professor once about prions back when I was a freshman. She told me they’re generally super stable, but misconformed proteins. So stable that enzymatic attack has no effect on it. Being dumped into ph 1 acid doesn’t destroy it. Uv light doesn’t scratch em either.
Prions aren’t very infectious. They’re not an airborne vector or anything. They’d be a really bad choice for germ warefare since 1) it’s super hard to infect someone, and 2) it takes about 10 years to kill.
Prison doesn’t really induce any diseases not found elsewhere, but it is a concentrated living environment, where one is in close quarters with other people with contagious diseases, so…
Oh.
Prion. :smack:
Never mind.
Science is just about never unanimous about anything.
Sure. Just not easily. They wouldn’t survive in the heart of the sun, for instance.
There’s no such thing as a 100% reliable method for anything.
It is inevitable that we will all die.
If you could come up with large scale production and delivery methods, I don’t see why not. But there’s not much point - there are better and simpler choices for germ warfare out there.
-Now, I hear that wild deer and elk in the northern USA and Canada
** Many mammals have a prion based disease. Sheep have scrapies, cows have Mad Cow, the original work was done with mice and hamsters. **
-do scientists unanamously accept prions as the cause of these diseases?
Although there are no certainties in science, Stanley Prusiner did win the Nobel Prize for his proof of the connection.
-can these prions be destroyed?
Technically, they are destroyable, but proteolysis, organic solvents, high temperatures, natural immune responses, and UV rays do nothing.
-are there 100% reliable methods for keeping this disease from the human population?
Keeping the disease from humans is impossible, namely, because prion based disases naturally arise in humans, ranging from the well known Creutzfeldt-Jakob Disease to the rare Fatal Familial Insomnia. There seems to be a genetic component that is passed from generation to generation involved. The regular version of CJD appears in the population at a rate of about one in a million every year.
-once infected with a prion, is it inevitable that the host will die?
At this point, all known prion diseases cause an early death for the infected.
Finally, could prions be used for germ warfare?
Prions, in my opinion, don’t appear to be a good weapon. Prions kill by changing the conformation of good proteins into bad ones and then aggregating together. They aren’t inherently contagious. They wouldn’t jump from person to person. Unless your body is going to naturally make the prion itself, the only way to get it would be to somehow get the prion inside your body (eat food with prions,etc).
Thanks for the info, but what exactly makes prions so stable? Ordinary proteins can be destroyed by heat (ordinary cooking temps will do). If a prion is a protein with a few extra kinks, what makes it so resistant to destruction?
well again, no cite, but it probably has to do with conformation. Some are just inherently more stable then others. Think Teflon. Teflon is one of the most unreactive substances ever, and IIRC it’s mostly due to it’s molecular shape.
I mispoke. Prions are simply much more resistant than regualr protein but compounds like SDS, Proteinase K, Trypsin can all have an impact on prions but they are muted when compared to the effects on proteins. Prions can handle temperatures in excess of 100 degrees. The conformation is simply a significantly more stable version. Prion cleaning solutions to limit the spread are being worked on as can be seen here.
A few other things about prions. Statements, questions, and conjecture:
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CJD has several variants the one which is associated with mad cow disease is so called variant CJD. However, there is another form termed “sporadic CJD” which some (outside of the manstream) believe is actually connected with a prion based vector if not Madcow/vCJD . For example there was a publicized “cluster” of CJD cases in New Jersey that allegedly centered around a horse racing track. The CDC investigated and supposedly determined these were naturallly occuring cases of so called sporadic CJD. Never the less they seemed to effect individuals in their 40’s and 50’s which is unusual for traditional sporadic CJD.
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My microbiology professor talked about a “cluster” of vCJD cases that occured in Kentucky in the last few years. Supposedly these occured do to a local tradition of eating and sharing squirrel brains with neightbors. I have also read of a few cases of sporadic CJD which have occured in hunters eating game (although it has not been proven that this represented transmission of the so called chronic wasting disease to humans).
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I seem to recall reading at Sciencedaily.com last year about a couple of compounds in testing that seemed to slow the progression of variant CJD. They worked by slowing the conversion of normal brain prion proteins (Prsp maybe??) into the diseased based prions (PrXX).
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Some criticise the beef industry in the United States for not more beef cattle for Mad Cow when slaughtered. Indeed, I seem to recall reading about a particular slaughter house that wanted to test EVERY cow that it slaughtered so that it could export beef to Japan (this was a couple of months after they found the infected cow out West and Japan blocked United States beef imports). However, the USDA (at least I think it was the USDA, lets just say some governmental agency for now) blocked their attempt to do so (under pressure from other slaughter houses who didn’t want to see this become some sort of standard). Indeed, it was only after they found the infected cow that the United States even started testing so called “downer cows”.
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Personally, I believe the likely source of vCJD prions to be sheep. That is because scapie has been a known prion based disease for many decades (centuries)…
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I seem to recall a United States special forces soldier contracting vCJD/Mad Cow disease after sharing a meal of sheep brain over in the Middle East (I think they were trying to foster relations with the locals to improve intel). I saw his family interviewed on the O’Reilly factor.
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I seem to recall reading that some molecular biologists are still not convinced that prions even exist. They believe that an as yet unidentified viral, or bacterial component exists (although it would have to be a very exotic bacteria indeed like nanobacteria or something). However, I think there number is shrinking.
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I have heard it suggested (again outside the mainstream) that a substancial number of people who die of Alzheimer’s disease are instead infected with sporadic CJD. Keep in mind however, that VARIANT CJD/ Mad Cow disease normally affects younger people.
Not to mention kuru among the Fore of New Guinea.
Humans, like other critters, have prion diseases.
There were also a number of cases of CJD some time back that are believed to be from the administration of human growth hormone to short-stature children back in the days when they had to refine the stuff from human corpses. These days, HGH is made through genetically engineered bacteria and thus does not pose a risk of disease. At least, not that sort of disease.
Yes, and there are some cases that are believed to be linked to contaminated surgical instruments, and things like corneal transplants from infected individuals.