Prions in urine

toilet urine

This is one of the scariest papers I have read.

All prion diseases – like the mad cow disease, scrapie, Kuru or Creutzfeldt-Jacob (CJD) – are incurable and fatal. Up to recently, we thought the only way you can get it is by ingesting the meat of the affected animal. Or, as I reported a couple of months ago, by ingesting drugs derived from the pituitary glands of infected dead humans.

A paper published 4 years ago describes another unexpected way to contract this horrible deadly disease. Using electrophoresis, mass spectrometry and liquid chromatography selected reaction monitoring, Van Dorsselaer et al. (2011) found prion proteins in a class of infertility drugs, the injectable urine-derived gonadotropins. These drugs are given to hundreds of thousands of women in North America for infertility treatment. They are developed from the urine of donor women, who are screened for all sorts of diseases, but the CJD has a long incubation period (decades) and thus it may be un-detectable using non-invasive methods.

Now, this in itself is not so worrisome as additional screening of the final medicine can be done and eliminate the batches with prions. What scared the living you-know-what out of me is the thought that the infected humans pee in the toilet and then that goes to the water treatment plants and then comes to your faucet. My question is: can the purification done at the water treatment plant eliminate the prions? I really, really do not wish to be alarming and panicky, especially in a world where every other news you read/hear seems to be something scary, so I invite anybody with knowledge about water treatment to comment and let us all know that is impossible, or at least highly unlikely, to get prions from the drinkable water. I don’t know how, maybe some step in the water treatment kills proteins as a matter of course or something.

Reference:  Van Dorsselaer A, Carapito C, Delalande F, Schaeffer-Reiss C, Thierse D, Diemer H, McNair DS, Krewski D, & Cashman NR. (23 Mar 2011). Detection of prion protein in urine-derived injectable fertility products by a targeted proteomic approach. PLoS One, 6(3):e17815. doi: 10.1371/journal.pone.0017815. Article | FREE FULLTEXT PDF

By Neuronicus, 18 November 2015

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Golf & Grapes OR Grandkids (but not both!)

Pesticides may be bad for you, but they are devastating for your great grandchildren, because there will be no great great grandchildren. Photo Credit: JetsandZeppelins from Flickr under CC BY 2.0 license
Pesticides may be bad for you, but they are devastating for your great grandchildren, because there will be no great great grandchildren. Photo Credit: JetsandZeppelins from Flickr under CC BY 2.0 license

Transgenerational epigenetic inheritance (TGI) refers to the inheritance of a trait from one generation to another without altering the DNA code (normally, evolution is driven by changes in the DNA itself). Instead, it happens by modifying the proteins that wrap around the DNA, the histones; these histones, in turn, control what genes will be expressed and when. Until a decade ago, TGI was considered impossible, nay, a scientific heresy since it had too close of a resemblance to Lamarckian evolution. But, true to its guiding principles, the scientific endeavor had to bite the bullet in front of amassing evidence and accept the fact that it may have been a kernel of truth to the so called ‘soft inheritance’.

Anway et al.’s paper was one of the first to promote the concept, ten years ago. They exposed pregnant rats to the pesticides vinclozolin or methoxychlor (only vinclozolin is still used widely in U.S.A. and several EU countries, particularly in agriculture, wine production, and turf maintenance; methoxychlor was banned in the early noughts). The authors found out that more than 90% of the male offspring had “increased incidence of male infertility”. These effects were transferred through the male germ line to nearly all males of all subsequent generations examined” up to great great grandsons, inclusively (Anway et al., 2005). (I don’t want to speculate how they managed to breed the low fertility males…). That doesn’t mean that the F5 generation was OK (the great great great gransons); it means that they stopped investigating after the F4 generation (or they couldn’t breed the F4s). Moreover, the mechanism of inheritance seems to be altered methylation of the DNA histones of the male germline, and not alteration of the DNA itself. Females were affected too, but they didn’t have enough data on that experiment (the Ph.D. student that did the work had to graduate sometime…).

Although the authors used higher amounts of pesticides than they suspected back then, in 2005, to be found in the environment, the study still gives pause for thought. After all, it has been 10 years since this paper plus the previous 20 years of use of the stuff. And no, you cannot get rid of it by washing your grapes and vegetables really thoroughly.

Reference: Anway, M. D., Cupp, A. S., Uzumcu, M., & Skinner, M. K. (3 June 2005). Epigenetic transgenerational actions of endocrine disruptors and male fertility. Science, 308(5727): 1466-1469. DOI:10.1126/science.1108190. Article + Science Cover + FREE PDF

by Neuronicus, 25 September 2015