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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."

23 of 214 comments (clear)

  1. Corrected article link by damn_registrars · · Score: 4, Informative

    For those with access to the journal Cell, you can view The Castilla, et al, paper online (this abstract should be available for all). The nature link in the summary goes to a write-up about the article, not the actual article itself.

    Those with subscriptions to Cell can also get the full text, Full Text in PDF, and the Supplementary Data.

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  2. Re:Folding@Home by ozphx · · Score: 5, Insightful

    Instead of donating energy to run Folding on your inefficient PC, where the results have to be triple-checked - consider just donating money directly to the project instead of via your power bill.

    Runtime on a trusted supercomputer / local cluster is going to be an order of magnitude more efficient in terms of data crunched per watt-hour.

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  3. Re:Folding@Home by g0dsp33d · · Score: 4, Insightful

    Or do both. I think they'll be glad for any CPU and especially any GPU cycles.

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    lol: You see no door there!
  4. While troubling, also cool. by fuzzyfuzzyfungus · · Score: 5, Insightful

    While I certainly wouldn't want to get any of the prion diseases, they are all rather nasty, I find the existence of prions fascinating. They are arguably even less alive than viruses, though not by much, and yet they multiply(in a sense), and exist in all sorts of variants.

    It seems like any sufficiently complex system(biological proteins in this case), is at considerable risk of having something analogous to life spring up and cause trouble.

    1. Re:While troubling, also cool. by jd · · Score: 4, Interesting

      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.

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    2. Re:While troubling, also cool. by oldhack · · Score: 5, Funny

      It seems like any sufficiently complex system(biological proteins in this case), is at considerable risk of having something analogous to life spring up and cause trouble.

      Your name is not "Murphy" by any chance?

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    3. Re:While troubling, also cool. by Hal_Porter · · Score: 5, Interesting

      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.

      --
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    4. Re:While troubling, also cool. by rve · · Score: 5, Informative

      These prions are single molecules that have a harmful effect on the host. I believe the word 'toxin' is a better description.

      Prions don't self replicate, it's a substance that catalyzes (speeds up) the reaction of refolding an existing protein into another shape, not the formation of a protein out of other substances. If it catalyzed a different kind of reaction, you'd call it a toxic enzyme, not something on the continuum of life.

    5. Re:While troubling, also cool. by cartman · · Score: 5, Informative

      Prions don't self replicate, it's a substance that catalyzes (speeds up) the reaction of refolding an existing protein into another shape...I believe the word 'toxin' is a better description.

      You're mistaken. Prions self-replicate by inducing other proteins to fold into prions like themselves. Prions thereby replicate and increase their numbers exponentially until they damage the organism. When symptoms appear, this process of exponential growth is already 95% complete and the organism will soon be dead. At that point, the organism is much more infectious because the number of prions is far higher than originally.

      Because prions replicate themselves, they bio-accumulate over time. Since organisms can "inherit" the prions of other organisms by ingesting them, the prions can accumulate across generations. Which means that you can feed cows to other cows continuously, and the number of prions in the cow population will increase over generations. It may take several generations of cow cannibalism before disease will become apparent.

      The prion hypothesis was interesting precisely because it proposed a mechanism of replication and infectivity which was not based upon DNA or RNA.

  5. Re:Rudimentary by fahrbot-bot · · Score: 4, Informative

    Considering that we force feed cows and chickens the meat bi-products of the industry.

    That's been illegal in the U.S. for cows for many years. I'm not sure about the current law for chickens. From a 2003 USAToday article:

    The United States and Canada in 1997 made it illegal to feed cows meat and bone meal made from ruminants. The feed bans in both countries do allow use of that feed for poultry and pigs.

    --
    It must have been something you assimilated. . . .
  6. Ailment? by ghoti · · Score: 4, Informative

    I'm sorry, but Creutzfeld-Jakob disease is a bit more than an "ailment." It's deadly and incurable. I think a slightly stronger word would be in order.

    --
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  7. Re:Folding@Home by nospam007 · · Score: 5, Informative

    >Runtime on a trusted supercomputer / local cluster is going to be an order of magnitude more efficient in terms of data crunched per watt-hour.

    Problem is, there ain't no such thing on this planet.

    From Wikipedia: http://en.wikipedia.org/wiki/Folding@home

    "On September 16, 2007, the Folding@home project officially attained a performance level higher than one petaFLOPS, becoming the first computing system of any kind to do so, although it had briefly peaked above one petaFLOPS in March 2007.[14][15]. In comparison, the fastest supercomputer in the world (as of June 2008, IBM's Roadrunner) peaks at 1.026 petaFLOPS[16]. In early May 2008 the project attained a sustained performance level higher than two petaFLOPS, again being the first computing system of any kind to do so. Now Folding@home computing cluster operates at above 2 petaFLOPS at all times, with a large majority of the performance coming from PlayStation 3 and GPU clients.[2] On August 20, 2008, the Folding@home project broke the three petaFLOPS milestone, once again being the first computing project of any kind in history to ever do so.[2]"

  8. Been known for quit some time by transporter_ii · · Score: 5, Interesting

    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:

    -=-=-=

    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 ..

    -=-=-=

    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
    1. Re:Been known for quit some time by tloh · · Score: 4, Interesting

      mod parent up. I did some reading last year on Cronic Wasting Disease (CWD was mentioned in the article) for my infectious disease class and examples like the outbreak at the mink farm just mentioned was very prevalent in available literature. I think most people are getting the wrong idea because the article is badly written for a non-technical audience. The novelty seems *not* to be that prions can cause cross-species infections, but that it has been demonstrated in vitro (by way of "protein misfolding cyclic amplification (PMCA) protocol") in such a way that elucidated some details (multiple forms as revealed by novel strain properties) that were not apparent before. This is interesting *not* because it is a ground breaking new discovery, but because it serves as a starting point for further studying cross-species prion interaction from a different perspective using different techniques.

      --
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  9. Re:Folding@Home by RickRussellTX · · Score: 5, Informative

    Depends on when you run it. Coal plants burn more coal at night than they need for electricity to keep the furnaces hot for peak usage periods. If you run F@H between 9PM and 6AM, you're actually not having much impact on fossil fuel use, pollution or carbon footprint.

    That's why electric utilities and some companies are developing programs to make the best use of off-peak power. Electric cars, for example, are exciting because they could engage timers that charge them only during off-peak.

    F@H could do the same in principle, with a check-box to run only during late hours. I don't know if they have that feature now.

  10. Scary by Pedrito · · Score: 4, Interesting

    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.

    1. Re:Scary by rrohbeck · · Score: 5, Insightful

      I didn't realize this, but it appears that a lot of prion diseases are fairly recent developments.

      People didn't eat as much meat as they do today, didn't live as long, and they certainly didn't feed their livestock with slaughterhouse waste. The latter is what got prions into the food chain in significant amounts.

  11. Mark Purdey's alternative hypothesis by nido · · Score: 5, Interesting

    ... 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.

    --
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    1. Re:Mark Purdey's alternative hypothesis by Reziac · · Score: 4, Interesting

      Yes, but now I'm wondering... DNA can be damaged/mutated by environmental factors; proteins can be damaged by chemicals (when I was in college, we used the crude method of boiling proteins in a saturated lye solution to break them down into their various amino acids); why should prions be immune?

      Which says nothing pro or con re this Purdey fellow's theory of the origin of BSE; he could be dead-wrong on that, yet correct as applied elsewhere. Or he may be completely off-base in every way, yet we should still look at *what* causes prions to "fold wrong"; who knows what we'll learn?

      --
      ~REZ~ #43301. Who'd fake being me anyway?
  12. Folding for Someone Else's Pocket by SuperBanana · · Score: 4, Insightful

    Sounds like another good reason to donate your spare CPU cycles to projects like Folding@home."

    So the public is donating a lot of computing time and electrical energy. What does the public get back?

    If Folding@Home goes towards lining the pockets of a university endowment or a drug company's coffers, count me out. If the research product is required to be free from patents, and available for public good...full speed ahead. Somehow, I seriously doubt that any successful results will be freely available.

    1. Re:Folding for Someone Else's Pocket by julesh · · Score: 4, Informative

      So the public is donating a lot of computing time and electrical energy. What does the public get back?

      If Folding@Home goes towards lining the pockets of a university endowment or a drug company's coffers, count me out. If the research product is required to be free from patents, and available for public good...full speed ahead. Somehow, I seriously doubt that any successful results will be freely available.

      The project is run by a non-profit company. Results are routinely made public. I don't see any reason to be concerned here.

  13. Re:Rudimentary by dubyrunning · · Score: 5, Informative

    That's been illegal in the U.S. for cows for many years.

    Not so. The FDA ban on feeding cattle protein to cattle excepts proteins derived from blood products and fat, and beef tallow is still used as a feed supplement at cattle farms. Also, since the bovine meat and bonemeal that used to be fed to cattle are still fed to other food stock like pigs and chickens - whose meal is, in turn, an accepted protein supplement for cattle - there is still a chance that infectious prions could find their way back into cattle (and us). Check out Michael Pollan's book, The Omnivore's Dilemma, for more info.

  14. Rosetta @ home by goombah99 · · Score: 4, Informative

    For this issue Rosetta at home (Boinc) might be a better choice for protein structure. It's already wokring on the prion problem.

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