X-Message-Number: 8445
From:  (Thomas Donaldson)
Subject: Re: CryoNet #8442 - #8443
Date: Thu, 7 Aug 1997 19:10:48 -0700 (PDT)

Hi!

Preserving heads, human or other, so long as they are the heads of mammals,
runs into a severe FUNDAMENTAL problem if you want to preserve them while 
awake: it is organs in the head which produce many substances which cause
aging and eventual death. I refer to the hypothalamus, the pituitary, and
the pineal gland in particular. (And of course just removing these will
cause derangements in other ways). That is the fundamental problem; there
are plenty of problems which are more technical. Keeping any organ alive
separate from a body is not at all simple, and the best so far has been
only a week or so. But the fundamental problem is something that would
have to be dealt with even if you solved all the technical problems.

I personally, as a matter of informed opinion, would say that if you found
a way to solve that fundamental problem then you would also have solved the
problem of aging, and suspension in many cases might not even be necessary.
Others might argue about this, however.

You may have heard that many cryonicists have chosen neuropreservation. This
basically consists of filling the head only (as much as practical) with
suspension solution, while lowering its temperature. In practice, a patient's
head remains attached to his/her body until all that is done. It is removed
just before placing it in dry ice, the first stage of taking it down to 
liquid nitrogen temperature. (Actually, if I understand current procedure,
liquid nitrogen is now used for all cooling, but no tissue should be simply
immersed. There is a very carefully design cooling regimen worked out to
bring down the temperature relatively slowly and with optimal speed).

If a head is removed before the blood inside has been removed, there will
be a serious problem with suspension. The clots are very hard to get out
once formed. Furthermore, hooking it up properly would require some
thought, since current methods remove the head after rather than before 
most of the procedure. In some cases, such as autopsies, cryonics societies
have been able to retrieve only the head or (in at least one case) only
the brain. This had been damaged so much by the delay that it was simply
frozen straight, with no attempt at cryopreservation.

We are all aware of the book to which you refer. I own a copy myself. Fleming
apparently either did not know about, or chose to ignore, the fundamental
problem I allude to above, and discusses only the technical problems in
keeping the head alive. That is a mean problem in itself, and he did no
experiments. 

			Best wishes,

				Thomas Donaldson

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