Prions Observed Jumping Species Barrier 214
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."
Corrected article link (Score:5, Informative)
Those with subscriptions to Cell can also get the full text [cell.com], Full Text in PDF [cell.com], and the Supplementary Data [cell.com].
Re:Rudimentary (Score:5, Informative)
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 [usatoday.com] article:
Ailment? (Score:5, 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.
Re:Folding@Home (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 [wikipedia.org]
"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]"
Re:Folding@Home (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 [google.org] 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 [greencarcongress.com].
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.
Re:Rudimentary (Score:3, Informative)
Mad cow disease, just so you understand it, is prion based. It does not just randomly happen. It is impossible for the brain to just make up prions. It must first come in contact with them by consumption or injection. Considering the fact that no one goes around injecting the bovine population with syringes filled with prions we must conclude a cow get's them by ingestion. That would mean that a "mad cow" infected animal got that why be eating the brain or spinal tissue of another MAMMAL.
http://www.citizen.org/pressroom/release.cfm?ID=1629 [citizen.org]
http://www.organicconsumers.org/madcow/silence51104.cfm [organicconsumers.org]
http://www.goveg.com/ABD_madcow.asp [goveg.com]
Re:cross species? (Score:2, Informative)
rodent would be the genus, hamster would be the species.
Re:Rudimentary (Score:3, Informative)
Since both sheep and cows are ruminants, that would mean that they aren't fed to each other. At least sheep wouldn't be fed to cows, the quote doesn't state anything about sheep feed.
Re:Rudimentary (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.
Re:Rudimentary (Score:1, Informative)
Wow, prions are like apostrophes. Once you see one moron misuse them you start misusing them too! "get's", dude? Get is, get was, something belonging to the "get"?
"t is impossible for the brain to just make up prions."
What are you babbling about? Prions are naturally in the brain, just folded the right way. Bad prions fold the bad way.
Rosetta @ home (Score:5, Informative)
For this issue Rosetta at home (Boinc) might be a better choice for protein structure. It's already wokring on the prion problem.
Re:While troubling, also cool. (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.
"Prion diseases" not caused by prions (Score:2, Informative)
While Mark Purdey may not be right about organophosphates (although they may have been a contributing factor) he is (was) correct that the scientific orthodoxy about CJ-like diseases is wrong.
Although prions are not directly my area of research, I have been an interested observer. It is my belief that the idea tha prions are a self-reproducing pathogenic protein (the idea that won Stanley Prusiner a Nobel Prize) is fundamentally wrong. So called "prion diseases" do, in fact, have have nucleic acid genome.
Now, there are not many people who are willing to go up against a Nobel Prize winner and 20 years of research - getting funding for such heretical ideas is not easy.
However, I do believe and hope that the truth of the situation will become apparent and "Science" will have some serious questions to ask itself... how can we have been so wrong about this for so long..?
So, while some of the results of Folding@Home are pretty amazing, spending any CPU time on the structure of prion proteins is utterly pointless.
BTW, if you want to play with protein structures, check out FoldIt (fold.it), it's made by the same people who made Folding@Home, it's pretty cool (there is no "Linux" version - so not that cool (it does run under Wine though)).
(Sigh)!!!! (Score:1, Informative)
The prion hypothesis was developed many years ago. The term is the condensed form of the "protein only" theory, prion... Whereby CJD developed presumably from scrapie or MCD... Which involved the transfer across the species barrier and made headlines... And now in 2008 you slashdot nerds have come across a new revelation that prions cross species barriers when that is how the term was originally coined... Deary me. Perhaps someone will discover that the world is really round.
Re:Rudimentary (Score:2, Informative)
The prion form of the protein is resistant to the enzymes that normally break down proteins, which is why prions are a problem in the first place. Even then the digestive tract blocks large proteins out pretty well, but very rarely one makes it through to start a prion infection.
Re:Folding for Someone Else's Pocket (Score:5, 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.
Re:Folding for Someone Else's Pocket (Score:2, Informative)
http://en.wikipedia.org/wiki/World_Community_Grid#Outreach [wikipedia.org]
"Also, as part of its commitment to improving human health and welfare, the results of all computations completed on World Community Grid are released into the public domain and made available to the scientific community."
Re:While troubling, also cool. (Score:5, Informative)
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.