Cecil:
I think this was implied but not stated in your answer about prions: Scrapie, the sheep disease, is another form of spongiform encephalopathy.
What’s the story on prions, which supposedly cause mad cow disease? (15-Jun-2001)
I just wanted to add that I thought this was one of the greatest columns ever. Full of the biting wit we’ve all come to know and revel in:
Hee. Hee. Hee. 
Cecil,
The term prion is actually an acronym for PRoteinaceous virION. A viron is a strange little virus-like particle that mainly infects plants. Also, to clear up a few things about Stan Prusiner: He’s a greedy, PR-hungry slimy bastard. He’s stolen research from other scientists by simply re-naming their observations and then getting his PR machine to disperse his new term. The Nobel was good for drawing attention to this interesting area of science, but Prusiner did not deserve it strictly for the work he had done. For more on the scoop about nucleic acid in prions (and to simply talk to a nicer guy who is very knowledgeable on the subject), you may want to contact Richard Rubenstein of the NY State Institute for Basic Research in Developmental Disabilities. Also, a good book on the subject is Deadly Feasts by Robert Rhodes (not incredibly technical, but a nice presentation of the prion problem with a political flair). And you shouldn’t feel totally safe from vCJD here in the US. There have yet to be any confirmed cases of Mad Cow here, but there are ‘frequent’ outbreaks of mink-SE (spongiform encephalopathy) in mink farms; which doesn’t really enter the human food chain…unless you really like mink. There were also a number of cases among large cats kept in zoos, as they were fed infected meat (as well as household cats and dogs, but not in the US). But a much larger danger is from wild deer, elk and other game animals. The SE disease in these animals is termed Chronic Wasting disease and it has been documented in the US for many years. The FDA is aware and I actually worked with samples from wild game to help better diagnose the disease. So tell all your hunter friends to beware, Bambi will get revenge!
Where did the figure of 1,300 cases in the “rest of the world” come from? There have been 1,200 reported cases in France alone, and investigations of routine “under-reporting” suggests the real figure is nearer 8000. Add Germany, Switzerland etc… Many of these cases are NATIVE and not linked to UK cattle. The UK figures remain high and this may be affected by the heavily enforced monitoring.
Given the habitual non-reporting that goes on in many agricultural circles, I would not be too sure of the “cleanness” of USA herds!! Note that US cattle are often treated with growth hormones, and the direct injection of these is amongst the few fully understood and demonstrated transmission methods of prions.
The next problem that has never been fully addressed (at least for the public) is that some of those people with new-variant CJD are vegans, and had been for a great many years. So how come we are so sure that prions are transmitted by feeding and not caused by other chemical effects?
Well, what I wanna know is, who decided it was pronounced “pree-on”? Shouldn’t it be pronounced to rhyme with “ion”?
Seriously, now.
I’m glad to see that, whether prions are real or not, I’m not the only person who says “Hey, wait a second!” when he hears descriptions of their behavior.
Nova showed an aircraft hanger full of the ashes or infected cattle, saying that the ashes were still infectious. A protein that survives being reduced to ashes? OTOH, a heavy metal could cause the same symptoms and would survive most anything the planet Earth could throw at it. But it’s not going to reproduce.
And piles of ashes in a bloody HANGER(!) is a safe way to store this stuff? What if somebody opens the door, by definition big enough to put an airplane through? Or if it floods? “Poisonous” ashes all over the place!
Sounds to this paranoiac like we are being manipulated with a load of hooey, but why?
Nope. Check out the seminal paper in which Prusiner coins the term:
Prusiner SB. Novel proteinaceous particles cause scrapie. Science 1982 ; 216:136-144.
It’s from proteinaceous infectious particle. Just like Cece says.
Interesting, I’ve always heard that he goes out of his way to avoid interviews and the like. As for his personal character, I’ve never met him, so I don’t know.
A"prion" (pronounced “pry-on”, IIRC) is a kind of bird. I guess the “pree-on” pronunciation is to prevent ruffling the feathers of ornithologists.
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Har.
I believe that whatever is the cuasal agent of BSE its route throught the the feed chain to cattle was due to a decision made by the then British government following lobbying by the feed producers and the rendering industry.
They succesfully applied to have the rendering temperature reduced in the plants which of course saved a deal of money in fuel bills.
Prior to this exactly the same material had been added to bovine feeds without any recorded problems for many years.
Still, whatever the details it was against the advice of some of the expert advisors, but not all.
Thanks Maggie Thatcher for jumping into bed with business and unnecassarily bequeathing this whole mess to us.WTG
Cecil said: “More importantly, prions reproduce without benefit of DNA or RNA, the only such instance in all of biology.”
No, it’s not. Or if it is, it’s true in only by semantics. There’s a
series of self-replicating proteins in yeast, identified a few years ago
and well-characterized by now. See, for example, “Prions: Portable prion domains” by Wickner et al. in Curr Biol 2000 May 4;10(9):R335-7
“Ha!” you scoff. “Scoff! Scoff!” you scoff. “That’s just another
prion!” you scoff. “It’s not a different example, it’s just the same
thing!” you scoff.
Technically, yeah. But it’s only semantics: any time a replicating
protein is discovered, it’s called a prion. That’s the whole class of
replicating proteins. So if you say–or scoff, if you like–that the only
examples of replicating proteins are prions, you’re safe, but meaningless. Yeast prions don’t look like vertebrate prions, except for that critical factor of being replicating.
It’s like defining “replicators” as “life”, claiming that “only living
things replicate”, and then dismissing, say, crystals as a counterexample by arguing that since they replicate, they’re living things, and therefore they’re not exceptions.
The fact that yeast prions exist makes vertebrate prions much more
plausible, since it’s clear the mechanism can work.
Ian
A couple questions for my fellow Dopers:
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What is it about this place that attracts all of these smartasses? Is it because Cecil is King of the Smartasses?
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Why does it take so long for some of them to find this place?
Welcome aboard, you two! Looks like you’ll fit right in.
FYI, Nicholas Regush at ABCNews.com had a recent sceptical column on prions and BSE:
http://abcnews.go.com/sections/living/SecondOpinion/secondopinion010525.html
The term “self replicating” with regard to prions is somewhat misleading. Cecil’s analogy of Ice-9 is more on the mark. Prion’s “replication” is more akin to crystallization, where a seed “crystal” converts an existing pool of subunits into another form by contact. The initial rate limiting step is the creation of (or exposure to) the seed particle.
I must confess I’m rather disappointed in Cecil’s prion column, which is rather thin on information & full of filler. In any case I thought I would point interested Dopers to this article, which lucidly explains prions, BSE, scrapie, & the history of British response to BSE:
http://www.lrb.co.uk/v22/n24/penn2224.htm
Among other things this confirms the assertion of the previous poster that Prusiner received too much credit–the key figure is Alan Dickinson. – Note that the article usefully stresses that while BSE apparently had its origins in the feeding of scrapie-infected sheep to cattle, it is not the same thing as scrapie–an important distinction, as the article makes clear.
There was also a fine, long article on the insomnia disease in the New York Times Magazine about a month ago–you can find it on their website though you’ll have to pay for it, unfortunately.
Well, no. gmachine asserts that Prusiner actually stole data, which is a rather serious (and AFAIK unsupported) accusation.
The article you listed, ndorward, merely states that Prusiner is “indebted” to Dickinson. In fact, from what the article says, Dickinson found a gene that apparently controls the incubation period of TSEs. That’s a far cry from putting together a novel mechanism for the transmission of an equally novel infectious agent.
My more cynical side interprets that article as being a bit too territorial. The journal is British, BSE is “an English disease” and Dickinson is “a typical product of the British biometrical/statistical school of genetics.” It’s also the first time I’ve ever seen Prusiner, who was born in Cincinnati, described as a “Californian scientist”. Dammit, this is our disease and we’ll be damned if some cowboy from the Colonies takes the credit for figuring the disease out!
OK, I’m a tad cynical, but by the article’s own admission Dickinson appareently took an indirect abstract genetic approach to the disease, whereas Prusiner’s experiments were more direct and more biochemical.
I’m not in the Prusiner fan club or anything, but as well all know, prions and BSE are not only controversial as a biomedial concept, they also have several metric tonnes of political baggage. Distortion of the facts is rampant and any kinds of statements (especially those not made in peer-reviewed journals) really need to be looked at with a skeptical eye.
Well, huh. You learn something new every day. Thank you, Alpha. However, your linked pic was kinda teeny and murky, so here’s a better picture of a fairy prion. “Pry-on.”
http://users.bigpond.net.au/palliser/photos/img052b.html
[wanders off muttering “pry-on, pree-on, pry-on, pree-on”…]
Just a few points–
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yes, the article’s got a British focus, but that’s not surprising given that its concern isn’t simply the disease but the relationship of its occurrence & somesequent spread to the British government’s actions–everything from the Thatcherite squeeze on scientific funding to the government’s efforts at silencing scientists & politicians who raised the alarm about BSE. (The piece is a review of the 5112-page report of the Phillips inquiry into BSE.)
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yes, the article in question isn’t in a peer-reviewed scientific journal; neither is The Straight Dope. All of which is to say that a layman like myself is forced to rely on the best popularizing accounts he can find. I’d welcome any corrections to the LRB article, of course.
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Sorry to confuse matters about Prusiner & the issue of credit–no, it does not substantiate the accusations made about intellectual theft &c earlier in this thread; it does strongly argue that he should have received considerably more credit (indeed suggests he ought to have been jointly awarded the Nobel).
I forgot to say in response to your comments on parochialism: for what it’s worth, the title “The English Disease” was surely chosen because it’s a pun (the usual, centuries-old meaning of the phrase is “melancholy” or, later, “rickets”: see the OED).
(Argh, typos: “subsequent”.) --N
(Typos round 2: “he” in the second half of my 3rd numbered point should of course be “Dickinson”. --N)
I must confess I’m rather disappointed in Cecil’s prion column, which is rather thin on information & full of filler.
I agree: I was very disappointed in this column. I find the subject of Prions (whatever the pronunciation) fascinating, and was hoping for a good round of Cecil-like separation of wheat from chaff.
Instead we got a lot of (yes, very entertaining, but) anecdotes and frippery. I love the frippy, but how about some of that frippin’ CecilAnalysis™? You know: dispelling myths and shining a light in the darkness, e.g. The Straight Dope on an issue.
Sorry, Cece. I calls 'em how I sees 'em: lame column. Funny, but lame.
Isn’t too much filler exactly how this whole mess started? Just be glad that Cecil didn’t use bone meal.