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Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

blogs.scientificamerican.com

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Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#111

Post by ergothus »

im3w1l wrote: post #97
thfuran wrote: post #89

Earlier quoted context omitted.

They can induce correctly-folded proteins to misfold, effectively replicating.

But shouldn't the number of misfolds be very limited or just one so that evolution cannot occur? It almost sounds like fearing that fire will evolve.

> fearing that fire will evolve.

Well now I have new nightmares... :)

But in seriousness, I don't know much, but I believe that protein-folding is a hugely complicated problem that still lies at the edge of our understanding, therefore I conclude that we can't really conclude that the options for a replicating, harmful prion are basically harmless.

I mean...we don't even really know how common prions are, right? We only have noticed a handful because they have dramatically bad symptoms. A large number of replicating but harmless prions could exist (right?).

Obviously there's no reason to panic, but considered caution and study seems a better reaction than overconfident dismissal.

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#112

Post by ergothus »

OldFatCactus wrote: post #24

I had project in college on Prions. Some interesting things I remember: * Kuru (laughing disease) was transmitted from cannibalism. Women and children of the tribe were more likely to contract it because they were more often given the less palatable parts of the bodies, which included brains * Some countries do not trust American cattle because our standards for Prion screening are too low * Kentucky has issues with…

A few questions:

* Do we have a good grasp on the number of prions in the world? My recollection from when MadCow became a big thing in the late 90s was that prions weren't even looked for and were hard to find as a general rule, but that was 20+ years ago. Might there be many common-but-harmless prions that we haven't even noticed?

* WHY is brain consumption (both in humans and in animals) such a source of prions? What makes that situation more likely to create prions?

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#113

Post by gnulinux »

crankylinuxuser wrote: post #84
mkagenius wrote: post #41

Earlier quoted context omitted.

The top comment sheds some light on the rarity of the disease and the article just being some sort of fear mongering -- https://news.ycombinator.com/item?id=18648393

If you don't eat brains, you're pretty much safe. If you eat brains, your risks go up by multiple magnitudes.

I wonder if it's limited to brain. If a cattle has prions and if you eat its tissues other than brain, can't you still contact prions via motor neurons?

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#114

Post by adamb »

sillypuddy wrote: post #43
arkades wrote: post #10

Prion disease is exceedingly rare. CJD is the most common, with an incidence of 1 per 1,000,000 person-years worldwide, inclusive of all transmission vectors (including medical procedures). Iatrogenic transmission is a rarer subset still: the riskiest transplants (with respect to CJD) are in the central nervous system. The UK tracked their transmission rates from 1970 to 2003 (a long period is needed because surgical…

Is alzheimers a prion disease, or maybe just Prions are involved?

My understanding is that there is some evidence that Alzheimer's is transmissible (e.g. higher rate of incidence in caregivers and neurosurgeons), but more study is needed.

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#115

Post by [deleted] »

dahfizz wrote: post #81
travisoneill1 wrote: post #66

Earlier quoted context omitted.

The example in the article has very little transmissive ability because it grows in the brain and eyes. If there were a respiratory prion disease that could be much different. By nature of being a protein they are simpler and harder to eliminate than bacteria or viruses: > In a particularly vexing twist, prions are also nearly impervious to destruction, even when attacked using a strenuous combination of disinfectant…

> If there were a respiratory prion disease that could be much different. Not really. The point your parent is making is that prions themselves don't reproduce like viruses and bacteria. Its basically impossible for a large scale breakout to occur and spread.

[deleted]

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#116

Post by than »

If you're interested in prions and some heavy science, I would highly recommend reading the research blogs of Eric and Sonia.

http://www.cureffi.org/ and http://www.prionalliance.org/blog/

> Wife-husband team Sonia Vallabh and Eric Minikel are on a very personal mission to find a cure to prion diseases. When Sonia was diagnosed as a genetic carrier of a rare disease called Fatal Familial Insomnia (FFI), she and Eric quit their regular jobs and began studying molecular biology to learn as much as they could.

Theirs is an incredible story so far. https://www.newyorker.com/books/page-turner/a-prion-love-sto...

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#117

Post by OldFatCactus »

ergothus wrote: post #112
OldFatCactus wrote: post #24

I had project in college on Prions. Some interesting things I remember: * Kuru (laughing disease) was transmitted from cannibalism. Women and children of the tribe were more likely to contract it because they were more often given the less palatable parts of the bodies, which included brains * Some countries do not trust American cattle because our standards for Prion screening are too low * Kentucky has issues with…

A few questions: * Do we have a good grasp on the number of prions in the world? My recollection from when MadCow became a big thing in the late 90s was that prions weren't even looked for and were hard to find as a general rule, but that was 20+ years ago. Might there be many common-but-harmless prions that we haven't even noticed? * WHY is brain consumption (both in humans and in animals) such a source of prions? W…

I am not a doctor or scientist.

From what I remember on the topic, we do not have a good grasp on prions disease. There is a good chance that some other diseases in history may have actually been misdiagnosed prions disease. It can present as a form of dementia and the incubation period can be so long that many people are middle-aged before symptoms occur.

Tissue of the brain and spine are better for Prions propagation. Prions cause other proteins to misfold themselves. The proteins they affect are related to brain matter.

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#118

Post by Dylan16807 »

jerf wrote: post #110
Dylan16807 wrote: post #105

Earlier quoted context omitted.

Are you saying that the more complicated things are, the more it hints at a simulation? Here, let me ask the most important question: What evidence about how things work on earth would make you less likely to believe the world is a simulation? Because it's always possible to come up with a justification after seeing evidence. (Other planets are a different issue entirely.)

Speaking for myself, I can not imagine what evidence would disprove the Simulation hypothesis. At the moment, reality is indistinguishable from being "real", for appropriate values of "real". There are things that would increase the likelihood of us being in a simulation, like us finding a QM effect of some sort where we can prove that what's actually happening is a computationally tractable simplification of what th…

> Speaking for myself, I can not imagine what evidence would disprove the Simulation hypothesis.

I'm not talking about absolute proof.

I'm saying that for a claim that evidence makes it "more likely", you can't just come up with a plausible reason. You have to weigh plausible reasons for and against it.

For every "more likely", there has to be a corresponding "less likely".

I can come up with plausible reasons that "less complex world" implies simulation, and I can come up with plausible reasons that "more complex world" implies simulation.

But unless I'm using conspiracy theorist logic, I have to weigh those against each other, and say that one of those pieces of evidence would overall make me less likely to believe in a simulation.

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#119

Post by sandworm101 »

prions wrote: post #56
sandworm101 wrote: post #27

Earlier quoted context omitted.

It is also an are where our innate fears, fears that modern society tells us are unacceptable, might have a place. There is a deep-seated fear of diseased people that once kept us healthy. Modern science has given us an understanding of disease that means there is often no need to physically separate paints where we know the disease is not easily transmitted. The shunning of an aids victim, or a child with cancer, is…

As stated in the parent comments that the likelihood of prions spreading in an infectious disease like fashion is very slim. Articles like this, ironically from a science-oriented publication, really don't help the conversation. Luckily modern medicine is fact based and not fear based.

Given that I have been exposed to the BSE prion, and so can never donate blood in north america, this is not a theoretical issue. The transmission of prion diseases are the subject of policy debate.

Re: Prions, Nearly Indestructible and Universally Lethal, Seed the Eyes of Victims

#120

Post by nonbel »

travisoneill1 wrote: post #109
nonbel wrote: post #100

Earlier quoted context omitted.

How is this at all a "twist"? The reason you cannot deactivate prions using these methods is that they are meant to denature protein. Prions are "amyloids"/beta-sheets, which means they are already in the lowest-energy state. This lowest-energy-state is exactly why the presence of prion can serve as a nucleation point for other proteins to denature into beta-sheets.

I don't care whether or not it's a "twist". I care that there is an entire class of pathogen that we don't know how to sterilize a surface of.

You just use bleach and then autoclave:

>"combining autoclaving (even at 121 degrees C) with a sodium hydroxide treatment is extremely effective." https://www.ncbi.nlm.nih.gov/pubmed/10658760

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