#scrapie

[vinnythefrog]

if you haven't (we just found your blog randomly) could you yap to us about

prion diseases

(weirdly interested in the topic^)

(not forced ofc, take as long as you need)

Oh my gosh we would love to! Also first ask let's goooooo!

So prion diseases (also known as transmissible spongiform encephalopathies) are rare neurodegenetive disorders that form in the brain due to the misfolding of the prion protein! It can affect lots of animals, and there are different strains!

Humans commonly (well when I say that I mean that the stats for humans with prion diseases are what we're looking at) get CJD, and some other neurodegenetive diseases such as Parkinson disease form in very similar ways!

The deer family (and also hampsters apparently) commonly get Chronic Wasting Disease! This is a disease that causes excessive drooling, stumbling, loss of agility and general weirdness. CWD can also be called Zombie Deer Disease due to its symptoms!

Cows get Mad Cow Disease, and sheep and I think goats get Scrapie. Humans can contract prion diseases from eating infected meat, but butchers don't sell that meant because prion diseases are deadly.

My personal favourite is Kuru! That's a disease that humans get from eating the brain or spinal cord of another human who already had Kuru! It likely started from a genetic malfunction and is super rare, buuut it's part of the reason why cannibalism is illegal!

Thank you so so much for asking me about one of my special interests! We're all super happy now! ><

[undrsk0re]

People are disturbed by cwd spreading to humans right

But what about scrapie. The sheep version. Where they compulsively scrape up against anything in sight to the point of scraping away their wool.

Imagine that but people

You go into a hospital, youre a doctor. Youve been called to an influx of people with the same symptoms and they believe your expertise will be able to help.

People are scared and confused.

The patients are scared and confused.

You show up. And you see the patients rubbing up against walls and medical equipment and any surface they can get to, some had scrapes and grazes from dragging their flesh upon concrete walls, some had blistered and rashes. And some were so far gone that they had rubbed away chunks of their own skin leaving lesions and exposed flesh in their wake. They seem unbalanced, they cant help but smack their lips, theyre biting and scratching at their own skin near constantly if they arent scraping it away. You look at the walls and see blood rubbed off on them. You're stumped. You cant get them to stop. You keep trying but they just wont quit. They all have this look in their eyes that shows their fear and delirium. They stumble and cant stand on their own, and one by one they perish. In about a week, most of them are dead, by the next, the remaining follow suite.

You conduct an autopsy and nothing appears off, you check for fungi and bacteria and viruses but nothing appears ary.

Until you cut open their head and see the thousands of spongey holes punched through one of their brains that you finally understand what befell them.

[radleysproposal]

i love diseases i'm a real diseaser i always gotta have wikipedia open on my phone it's usually on rabies yes yes

[er-cryptid]

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[abpoli]

2 Alberta flocks quarantined after fatal disease related to mad cow found in a sheep | CBC News

Two sheep flocks in central Alberta have been quarantined by the Canadian Food Inspection Agency (CFIA) for scrapie, a fatal disease that af

Two sheep flocks in central Alberta have been quarantined by the Canadian Food Inspection Agency (CFIA) for scrapie, a fatal disease that affects the central nervous system of both sheep and goats and is related to mad cow disease.

The CFIA said in mid-June it confirmed a sheep had scrapie, and implemented disease-control measures at that farm. 

It found the diseased sheep had lived on multiple premises, which resulted in a flock at a second farm being quarantined as well.

Continue reading

[neurosciencenews]

Microglia Are Key Defenders Against Prion Disease

The findings suggest that drugs that increase the helpful activity of microglia may have a role in slowing the progression of prion diseases.

The research is in Journal of Virology. (full access paywall)

[torontostudent]

History of Prion Research

As for prion research, they started by trying to study scrapie infectivity in mice through the use of sedimentation properties. They didn’t really learn anything for this except that infectivity was spread throughout the entire gradient - i.e. their method of measuring for infective particles didn’t work on scrapie (didn’t separate the infective particles cleanly). Thus, different research methods had to be devised.

In in vitro studies, they tried to inject brains of scrapie-infected sheep into lab mice, but found that it took another 1-2 years of inoculation for the mice to succumb to the disease and become available for data collection. This was too slow for the scientists, but then they discovered that syrian hamsters succumbed much more quickly to the scrapie disease. Thus they began experimenting on syrian hamsters instead for scrapie studies.

They found the phenols, which could hydrolyze or modify proteins, reduced scrapie, but the disease was resistant to treatment methods that altered nucleic acids (UV radiation). Then finally the hypothesis that scrapie was a protein emerged. Thus they coined the term prion, based on how it was proteinaceous and infectious.

PrPSc (Scrapie form of Prion Protein) was identified from the brains of sheep infected by scrapie. They tested portions of sheep brain to see if they were capable of being infected, and they were. The cellular form has superscript C and is not infectious. This prion protein has a molecular mass of 27-30 kiloDaltons and is the protease-resistant core of PrPSc. They managed to sequence the N-terminus of the protein through Edman degradation (way of sequencing where you cleave off amino acids one by one in order to get the correct order). This allowed them to reverse predict the nucleotide sequence and then conduct molecular cloning experiments.

Interestingly, they found that mRNA levels for this gene were the same in infected and uninfected animals, which meant that the disease wasn’t being spread on an mRNA level. They also found a protein that was from the same sequence in animals that was sensitive to protease (the disease protein was not sensitive to protease). They named this isoform (same sequence, different 3D structure / alignment) the PrPC protein. Afterwards, cDNA probes became available (complementary DNA) and using these cDNA probes they were able to find where in the body these PrP proteins were being expressed. The result was that the PrP proteins were expressed in the brains of uninfected adult mammals.