science news

[LizStreithorst]

I heard this on Here And Now, an NPR news program.  I heard it while passing by the radio.  I don't know the name of the science reporter.  I wanted to listen to it again but it's not up on their website yet.  The reporter said that there was evidence that Alzheimer's and Parkinson's might be linked to a prion infection.  Not Mad Cow because we don't have that here in the States.  It would have to come from somewhere else.  If it's so, it would be a huge discovery.

Changing the subject, Oliver Sacks died yesterday.  I will miss him.

[LizStreithorst]

I googled around and found this.  It was a little over my head but not too far over.  It says basically that they are looking into it but have no idea where the prion comes from.  They also say that there is a genetic predisposition to people exposed to it developing it.

[LizStreithorst]

I'm stilling looking for the prion thing.  I have failed so far.  I did find this about Oliver Sacks.  He was still alive when it was broadcast.  http://www.sciencefriday.com/segment/05/01/2015/the-other-side-of-oliver-sacks.html

[LizStreithorst]

If anyone loves Oliver Sacks as much as I do you should listen to this: http://www.npr.org/sections/health-shots/2015/08/31/436289763/oliver-sacks-a-neurologist-at-the-intersection-of-fact-and-fable

[LizStreithorst]

Ha!  I finally found what I was looking for.  They ran the same story on All Things Considered.  I found the long story by looking up the contributor's name.  http://www.npr.org/2015/08/31/436377464/scientists-discover-new-disease-caused-by-prion-protein

[BillT]

Here is another little story on the issue:
http://www.sciencemag.org/content/349/6248/1255555.abstract

Prions are weird. They are not alive like cells or (some would say) viruses.
They start out as a normal protein (say protein A). The get their shape changed in some way that makes them stick to other normal protein A's. When this happens the normal protein A's they stick to are changed to the prion shape. 

This would be somewhat like a piece of paper folded into some (normal) origami shape (like a dog). It is then folded into some other shape (like a unicorn). Its the same piece of paper, but it has a different shape that changes its function and hows it interacts with (sticks to) other proteins. These proteins do not reproduce. They are made by normal cells. However they can propagate their shape change to other proteins of the same kind that they encounter.

The various diseases in which prions act are not really related by the proteins being effected, but they share a common mechanism of how they get weird.
Different proteins can be affected in different disease.

How these misshaped proteins get around the body is not really clear.
Mad Cow transmission should go from bad cow meat --> stomach digestion --> blood stream --> brain
It is not understood (at least by me) how it gets out of the stomach (where proteins should be digested, which would destroy their structure) of how it gets into the brain. Entry to the brain is usually regulated by the blood-brain barrier which doesn't let just anything into the brain.

[LizStreithorst]

I read that article when I was searching for the story that was broadcast.  I believe that the contamination with Mad Cow and the disease that sheep have is transmitted to the muscle meat when it comes into contact with the infected brain or spinal cord.  It's a very strange and fascinating disease.  What I found most interesting is that they think that Parkinson's and Alzheimer's may be caused by prions.  They said something in the story that I knew but had forgotten.  That Autoclaving surgical instruments doesn't destroy prions.Makes me wish I were working in that field.

[BillT]

The Mad Cow bad proteins are in meat because the meat (muscles) is innervated by axons from nerve cells in the CNS (which make the muscles move).

Autoclaving (which is pretty much pressure cooking) will kill everything, but prions are not alive so they can't be killed.
Nor, apparently, does autoclaving mess up their structure enough to keep them from doing their bad prion thing.

[LizStreithorst]

I can see it being transmitted by the nerve cells in the meat.

No, autoclaving can't help.  I just hope that they find the key to Alzheimer's and Parkinson's with this research. 

Did you ever read about the study done with the nuns?  If not, I'll google around and find it for you. 

[BillT]

I have heard about some drug being worked on that will cause the bad proteins to be excreted from the brain. This could be beneficial.

I heard about  study of some nuns and sentence complexity. It had something to do with Agatha Cristie sentence complexity and dementia.
http://www.npr.org/templates/story/story.php?storyId=127211884

[sschind]

Two cows are standing in a field, the first one says

"say, did you here about this mad cow disease?"

second one says

"who cares? I'm a helicopter."

[PaulineMi]

Two cows are standing in a field, the first one says

"say, did you here about this mad cow disease?"

second one says

"who cares? I'm a helicopter."

[Mugwump]

Two cows are standing in a field, the first one says

"say, did you here about this mad cow disease?"

second one says

"who cares? I'm a helicopter."

[BillT]

I was in England (doing a post-Doc in a lab) eating cow meat among other things when they had their mad cow panic.
Now I can't donate blood here.

[LizStreithorst]

If that's the case I'm sure you know more than I do about prions.  I first learned about it from a book.  Could have been Richard Preston.  It was before the Mad Cow thing, if I remember correctly.  It only described Kuru.  I was immediately fascinated.  I told the vet I worked with about it.  He thought that I had been reading some kind of quack crap.  Months later he came to me talking about his knowledge about prion diseases.  He must have read about it in the scholarly magazine they get.  To everything he told me I said, "I know".