14 votes

The Case for Transmissible Alzheimer's Grows

2 comments

  1. Atvelonis Link
    It's worth emphasizing off the bat the meaning of the word "transmissible" in this context. I think the Tildes community is not very susceptible to "not reading the article" syndrome (as it were),...

    It's worth emphasizing off the bat the meaning of the word "transmissible" in this context. I think the Tildes community is not very susceptible to "not reading the article" syndrome (as it were), at least not as much as Reddit is, but even so.

    In rare cases (so far as we know), human prion transmission has happened when surgical instruments used on an infected patient were cleaned and reused on an uninfected one. Prions stick to steel like glue, are stable for decades at room temperature, and survive a bombardment of chemical and physical cleaning assaults that are more than sufficient to obliterate other pathogens. Prions are survivors.

    It is important – imperative – to emphasize that transmissible does not equal contagious. There is absolutely no evidence that people with dementia can spread their disease casually to people around them. Even donated blood appears to be safe, as no association with blood transfusions and Alzheimer’s Disease has ever been detected.

    The realization that the peptides involved in some of the most common and feared dementias on Earth may be transmissible under even limited conditions is a sobering and humbling reminder of how very little we still understand about them. Given what we know about prions, I think we would be wise not to underestimate their abilities.

    Nevertheless, this is indeed concerning. And as morbid as the subject matter is, I'm fascinated by the sheer willpower that these little life forms seem to hold in the face of complex laboratory cleaning procedures. But if we can implement more thorough systems to sufficiently denature prions, which is completely possible, then presumably the issue will be limited somewhat.

    Sterilizing prions, therefore, requires the denaturation of the protein to a state in which the molecule is no longer able to induce the abnormal folding of normal proteins. In general, prions are quite resistant to proteases, heat, ionizing radiation, and formaldehyde treatments, although their infectivity can be reduced by such treatments. Effective prion decontamination relies upon protein hydrolysis or reduction or destruction of protein tertiary structure.

    7 votes
  2. eladnarra Link
    Welp, that was a good article to read at night when my health anxiety is more active /sarcasm Interesting that prions are so resistant to denaturing (as @Atvelonis points out). We didn't study...

    Welp, that was a good article to read at night when my health anxiety is more active /sarcasm

    Interesting that prions are so resistant to denaturing (as @Atvelonis points out). We didn't study them much in biochem beyond the general concept, and I would have assumed that things like proteases would be relatively effective. (I guess it makes sense, considering we can contract prion diseases by consuming tissues with them...)

    3 votes