[extropy-chat] Alternative to Cryo was The Amazing Cellular Repair device

Eugen Leitl eugen at leitl.org
Tue Oct 11 09:37:33 UTC 2005


On Tue, Oct 11, 2005 at 02:03:38AM -0700, The Avantguardian wrote:

> Yes. But my take on cryogenics is not to freeze people

It's cryonics. Cryogenics is something different.

> and to repair the damage later but figure out a way to
> put them in suspended animation without damaging them

No can do, save of a time-freeze spell. Given that
our current knowledge of physics doesn't even give a
hint how that could be possible, your next best bet is
a modern cryopreservation method.

These are actually quite good, and can't be (much)
improved upon -- especially if you're aiming for
structural preservation, and not viability (which 
is a somewhat different, and harsher metric).

> in the first place. It might not even require lowering
> their temperature to 0 Celsius. Are you familiar with

You're making me intensely curious here.

> the work of Blackstone et al., Science 2005? Here's
> the link, I assume you have an institutional
> subscription:
> http://www.sciencemag.org/cgi/content/full/308/5721/518
> 
> Anyone who can't access it but wants to read the
> article, email me and I will send it offlist. In a
> nutshell, the authors demonstrate a state of suspended
> animation in their mice, in an atmosphere where oxygen
> is replaced hydrogen disulphide gas. They show that

Have you ever worked with H2S?

http://scholar.google.com/scholar?hl=en&hs=50u&lr=&c2coff=1&safe=off&client=firefox-a&rls=org.mozilla:en-US:official&sa=X&oi=scholart&q=H2S+toxicity+humans

You don't want to gas a primate with H2S, oh no.
This is worse than using cyanide.

> the core body temperature of the mice drops to
> essentially ambient temperature and the mice's
> metabolism dropped to 10% normal rate thus aging at
> 10% normal rate. The mice were kept in such a state of
> torpor for 6 hrs then revived with no ill effects. The

Don't try this with people. What would happened with
your mice after 6 days? 60 days? 6 years?

> authors didn't lower their temperature to below 13
> degrees celsius, but I have hunch they could have
> lowered it all the way down to just above 0 Celsius at
> which point, the mice would have probably not aged
> appreciatively at all. No actual freezing means no

I recommend you to hit Medline for hypothermia and
chilling injury. They wouldn't have aged much, because
they would have been dead pretty soon.

> freezing damage, yet there is almost no metabolism

"almost no metabolism" doesn't mean your biology is
frozen in a glass matrix. Your mice continue to unravel
at nanoscale, albeit somewhat slowed. Quite soon
your cross the point of no return by which the system
can resume with own power, and your rodent is gone for good.

With vitrification, no damage occurs beyond of the
original caused during the suspension. And it quite
easy to measure what that damage is, and to gauge
how much of it is irreversible information erasure,
and which can be transformed back at structure descriptor
level.

> because there is no oxygen to metabolize. Of course
> the authors might have tried this and failed but they
> don't mention it. In any case, I think THIS technology
> is a bit more immediately attainable than error-free

No way. 

> freeze thawing. Especially because Science is an

It would be a rather stupid idea to warm up a vitrified
critter. You'd get orders of magnitude more damage than
during the suspension. We've been through this before,
multiple times, in fact.

It might be sufficiently low to allow retransplantation
of healthy organs with a survival rate high enough to
be practical, but you don't want to have this happen to
the whole human primate. Trust me.

> impecable peer reviewed journal.

There is not much cryobiology in Science. Cryobiology
is similiarly peer-reviewed (not impeccable, no journal
is that).

I wish a had a subscription. Does anyone have institutional
access to Cryobiology?

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07100, 11.36820            http://www.leitl.org
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