X-Message-Number: 7685
From: "JDY" <>
Subject: Hextend as cryoprotectant?
Date: 11 Feb 97 06:48:27 GMT
Newsgroups: sci.cryonics

I came across a news item at http://www.businesswire.com/cnn/btim.htm,
dated may 96. It's probably old news to most readers here, but it was new
to me. BioTime researchers were presented results at a meeting, and the
text mentioned experimental results which pointed to the possibility for
long term preservation of organs. My question is, would the solution
(hextend?) be useable as a cryoprotectant? Are any of the cryonics
organizations considering using it? Why or why not?

BTW I also noticed that BioTime is on the top 25 list of individual
investor magazine. Perhaps if their Hextend product enjoys commercial
success, some of their profits will be reinvested into cryopreservation of

Jim Y.

Here is an excerpt:
    Additional research on the use of Hextend supplemented with
cold-protective agents was presented by Dr. Hal Sternberg, BioTime's
research vice president.  He described experiments in which hamsters
were completely blood substituted at hypothermic temperatures with
BioTime solutions, and then placed in sub-zero freezing baths for
periods of up to 2 hours.  These animals reached deep body
temperatures as low as -4 C, and then were revived to consciousness
and reactivity.  An analysis of brain tissue immediately following
revival indicated that substantial freezing and thawing of the
tissues of the brain had occurred.  Sternberg said "these
experiments reveal that mammals can survive - at least for short
periods - partial freezing of vital organs, if their blood is
replaced with solutions which guard against some of the damage caused
by ice crystallization.  These studies suggest that techniques for
maintaining a wide variety of tissues and organs in frozen or
partially frozen states for extended time periods may be achievable
when adequate solutions and protocols are developed.  This
breakthrough could lead to long term organ and tissue banking for

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