X-Message-Number: 4017
From:  (Brian Wowk)
Newsgroups: sci.cryonics
Subject: Re: Reversal of Freezing Injuries
Date: 14 Mar 1995 23:47:49 GMT
Message-ID: <3k59v5$>
References: <3jrsbg$>

	Cryobiology is a large field with thousands of published papers
covering topics ranging from insect winter survival mechanisms to how
freeze human embryos.  Only a small subset of this knowledge is relevant
to cryonics.  An extensive list of references can be found in the
monograph, "The Cryobiological Case for Cryonics", available from
either Alcor or CryoCare.

	As a general rule, many individual cell types can be successfully 
cryopreserved, while large organs cannot be.  (Skin, corneas, and
small intestines are the only organs I know that can be reversibly
cryopreserved today.)  One cryobiology lab (formerly at the Red Cross,
now at Organ, Inc.) is tantalizingly close to a breakthrough with
cryopreservation of the human kidney.  If this works out, the next
target (for cryonicists, anyway) will be the human brain.  This could
be anywhere from two to ten or more years away.  That's where cryonics
is at today.  Don't expect reversible cryopreservation of whole bodies
for at least 40 years, IMHO.

	Natural anti-freeze compounds, by the way, are not useful for
organ cryopreservation as they only protect down to -40'C at most,
while -130'C or lower is needed for true long-term storage.

---Brian Wowk

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