Miracle Max, Right as Usual
A while back, I posted a book review in which I recommended Nick Lane's Power, Sex, Suicide: Mitochondria and the Meaning of Life.
Today, on Microsoft's MSN homepage, they're touting an article from Newsweek. In it, scientists discuss what they've learned about what happens when your heart stops beating. Of particular interest is the fact that you're not dead. For at least a few hours after your heart stops beating, although you are, by definition, clinically dead, you remain very much alive; all your cells are still alive. Your brain has shut itself down to preserve oxygen, but it's alive. Nonetheless, medical science shows that attempts to revive a patient whose heart has been stopped for more than a few minutes will fail. The patient is dead.
So you're not dead, but you are dead. What gives? Ah, it's those tricky mitochondria that Nick Lane wrote about.
See, they're the organelles that tell the host cell when it should self-destruct, a process called "apoptosis" (the second "p" is silent if you're scoring at home, or even if you aren't). This is how the body destroys most cancerous cells long before they become a problem; it tells them to self-destruct. Or rather, they tell themselves to self-destruct. Or rather, their mitochondria tell them to self-destruct. If this signal doesn't happen at the appropriate time, cancer is the result.
When your heart has stopped beating for more than a few minutes, then oxygen is suddenly resupplied to your cells -- say, as a result of medical procedures to restart the heart -- the mitochondria in your cells sense that something highly weird has happened and, just to be on the anti-cancer safe side, each of them tells its host cell to commit hari-kari. Boom. Now you're dead. Not just mostly dead, but completely dead, and nothing can bring you back -- not even to blave.
In other words, what kills you isn't your lack of a heartbeat, or even the resulting lack of oxygen, but the doctors' attempts to revive you by flooding you with oxygen and kickstarting your heart. Now that they know this, they're working on ways to resupply your body with oxygen gradually, to prevent putting your mitochondria in kamikaze mode.
Once again, our definition of "dead" has gotten fuzzier.
Today, on Microsoft's MSN homepage, they're touting an article from Newsweek. In it, scientists discuss what they've learned about what happens when your heart stops beating. Of particular interest is the fact that you're not dead. For at least a few hours after your heart stops beating, although you are, by definition, clinically dead, you remain very much alive; all your cells are still alive. Your brain has shut itself down to preserve oxygen, but it's alive. Nonetheless, medical science shows that attempts to revive a patient whose heart has been stopped for more than a few minutes will fail. The patient is dead.
So you're not dead, but you are dead. What gives? Ah, it's those tricky mitochondria that Nick Lane wrote about.
See, they're the organelles that tell the host cell when it should self-destruct, a process called "apoptosis" (the second "p" is silent if you're scoring at home, or even if you aren't). This is how the body destroys most cancerous cells long before they become a problem; it tells them to self-destruct. Or rather, they tell themselves to self-destruct. Or rather, their mitochondria tell them to self-destruct. If this signal doesn't happen at the appropriate time, cancer is the result.
When your heart has stopped beating for more than a few minutes, then oxygen is suddenly resupplied to your cells -- say, as a result of medical procedures to restart the heart -- the mitochondria in your cells sense that something highly weird has happened and, just to be on the anti-cancer safe side, each of them tells its host cell to commit hari-kari. Boom. Now you're dead. Not just mostly dead, but completely dead, and nothing can bring you back -- not even to blave.
In other words, what kills you isn't your lack of a heartbeat, or even the resulting lack of oxygen, but the doctors' attempts to revive you by flooding you with oxygen and kickstarting your heart. Now that they know this, they're working on ways to resupply your body with oxygen gradually, to prevent putting your mitochondria in kamikaze mode.
Once again, our definition of "dead" has gotten fuzzier.
posted by juvenal_urbino | 5:50 PM
5 Comments:
So the important question is: At what point is it appropriate to go through their pockets looking for spare change?
Precisely. And how long after being revived is it okay to go swimming?
Apologies to all, btw, for the downer "to blave" link. It was the only one I could find that explained it right at the top of the page.
That's some interesting stuff, there.
Innit?
We were already struggling with defining "death," given our existing medical knowledge and capabilities. (To wit: Terri Schiavo.) Now we can add to the confusion the case where someone has been without a heartbeat for several hours, but might still be revivable. I guess we'll have to add "heart dead" to our list of special categories, like "brain dead."
What are the implications for, say, organ transplant? If you can't declare the person dead until their cells are dead, I would think their organs will no longer be of any use. But you can't very well take them while their owner is still "alive," can you?
Those are great questions, JU. Now I might actually have to read a book on mitochondria. And I'm blaming you for that. Because I already know it'll make my head hurt.
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