Question on bovine spongiform encephalathopy (sp?).

BSE is discussed in the current issue of Newsweek, and I believe there might have been a question regarding it in the past here on the Board, I haven’t been able to find it in a search.

Everything I read seems to indicate that you can’t kill BSE with heat, as you can with bacteria. Why? And if you can, am I going to have to start eating my T-bones well-done? (Gack)

Has been discussed before:

Basically if I understand the situation, BSE is probably caused by a Prion, a protein string fragment. This is not ‘alive’ as are bacteria and viruses. Heat does not necessarily break down these protein fragments as it does bacteria and viruses by destroying their metabolism. Nor do any disinfecting chemicals work. In order to break down the protein strings, extreme heat or other (chemical) intervention would be needed that would destroy the chemical bonds holding the string together.

Those prions are pretty damn robust things as pjen said, although I’d have to disagree that viruses could be in any way considered alive like bacteria.

Cook your T-bone as well as you like, it’ll make no difference;)
Red meat with no traces of spinal cord or brain material appears not to be infective (I think that in experiments they made cows eat a LOT of their peers’ red meat, though how well done it was I don’t know, none succumbed to infection.). T-bone steaks were banned here for a while (UK).

The nasty bits…

I used quotes around ‘Alive’ for a reason. The fact that viruses are made of DNA RNA strands and are able to multiply using cells as hosts means that their status is oftensen as on the edge of alive/not alive.

I did err when I mentioned metabolism- what I should have said was heat etc. can destroy bacteria and virus complex structure at relatively low temperatures, which is not true for Prions.

Thanks for the link, Pjen. I thought I had seen it somewhere recently, but my search didn’t work.

Thanks for the answers, too. Now I have more questions, though. If a prion isn’t alive (or even marginally in the land of the living, like a virus), how can it “infect” us? If it’s just a nonliving substance, then wouldn’t it be more accurate to describe it as a poison?

And I’ll take my t-bone medium-rare, as always, andoid! Thanks.

The difference between a prion and a poison is the fact that prions can, in fact, replicate. Sort of.

Here’s how prions work: protein X can exist in two forms, X1 and X2. X1 is the normal protein found in the body and has some funtion. X2 is the same protein, in that it’s made of the same string of amino acids, but its 3D structure is rearranged, giving it a new function. What makes prions unusual is that the function of X2 is to turn X1 into X2, thus making more copies of X2 and depleting the source of X1. It acts like a vicious cycle - X2 (the dangerous form) increases exponentially while X1 decreases at the same rate.

It’s the replicative property of a prion that makes the word “infection” make sense. A poison just gets into the body and does its thing without any replication.

I posted some threads on the above topics a while ago (BTW, I originated the phrase “Mad Cow Cheese” and gladly take credit for that…

It is not true that you brain or spinal cord is the only tissue that will transmit prionopathy (also a term I originated right here on this Board).

CJD had been transmitted by: corneal transplants and blood injection (eg by the use of scalp EEG and muscle EMG electrodes).

I’d be interested in hearing doper’s opinions on this article:

It scared the living crap out of me, until I realized that there was absolutely nothing I could do about the situation.

There has been a localized outbreak of new variant CJD in a county in middle England- Leicestershire- around the village of Queniborough:

Last week the Investigators of the outbreak said that they had made a major discovery about the means of transmission and would be informing the residents in the near future, and the rest of us towards the end of the month.

British beef is probably now safer than that from Europe because of the extreme protection methods used here compared with there over the past few years. What is happening in the States is anyone’s guess as there is a natural reluctance to take any action that could effectively destroy the meat industry. Any whistleblowers would be aware what happened to Oprah!

The same as in Britain, the USA will be fully informed when it is too late!

Yet another thread on the topic… contains some interesting links.