X-Message-Number: 33100
From: "Jens Rabis" <>
Subject: AW: CryoNet #33098
Date: Sun, 5 Dec 2010 12:33:14 +0100

Hi cryonauten, hi ben

Xenon protects neurons from the toxicity of oxygen deficiency. One should
check whether Xenon is additional (!) suitable for artificial respiration
(stand-by-teams)? Priority for dead impact accumulation patients!? 

Keywords: Wolfgang Kox Xenon neuroprotection

Infos: http://www.freepatentsonline.com/6559190.html


Xenon schutzt Neuronen vor der Vergiftung bei Sauerstoffmangel. Man sollte
prufen ob Xenon zusatzlich(!) zur kunstlichen Beatmung ( Stand-by-Teams)
geeignet ist!? Prioritat tote Schlaganfallpatienten.

Infos: http://www.freepatentsonline.com/6559190.html

Stichworte: Wolfgang Kox Edelgas Xenon rettet Hirnzellen

Best greetings
Jens Rabis

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Auftrag von CryoNet
Gesendet: Sonntag, 5. Dezember 2010 11:00
Betreff: CryoNet #33098 - #33099

CryoNet - Sun 5 Dec 2010

    #33098: Re: could argon/xenon improve vitrification solutions? [benbest]
    #33099: parallel  histories  theory [Hal Tindale]

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Message #33098
Date: Sat, 04 Dec 2010 16:52:58 -0500
Subject: Re: could argon/xenon improve vitrification solutions?

   Sorry if I am always raining on your parade, Doug, but when I see
misconceptions in your postings I feel the need to set the record straight
if there is to be hope of progress.
I do greatly appreciate the interest you show in the possibility of
reversible cryopreservation and the research that you do toward this end.


All of the studies you cite except the xenon clathrate biostasis paper deal
with the subject of reducing ischemic damage by substituting noble gas for
oxygen. Despite the fact that a couple of these papers involve hypothermia,
this has no relevance to improving vitrification solutions.

    I also doubt that xenon clathrate cryostasis is of any benefit to
vitrification, although it could be of value in cryopreservation methods
classically associated with freezing. The debate still rages within the
cryobiology community as to whether freezing or vitrification is the best
method of cryopreservation. Many single-cell and small tissue specimens can
be successfully cryopreserved in liquid nitrogen using small amounts of
cryoprotectant that reduce the ice formation that occurs outside of cells.
The small amounts of ice formed can be tolerated in small tissue samples and
cell suspensions, and using only small amounts of cryoprotectant does not
involve much toxicity. Until less toxic cryoprotectants can be found, this
is the best approach for certain cell types. For more detail on classical
cryogenic cryopreservation using freezing, see


  These methods have no hope of ever being applicable to large organs. Those
ignorant of cryobiology often suggest that cells burst upon freezing because
ice has 9% greater volume than water. That claim is false, because water
first freezes extracellularly, but it is nonetheless true that a 9% greater
volume of ice in the extracellular space will nonetheless mechanically crush
cells. Clathrate hydrates occupy a larger volume than ice, so any attempt to
form these clathrates in an organ would result in even greater mechanical
As I said in my analysis of clathrate hydrates: "The volume of a clathrate
is greater than that of hexagonal ice containing the same number of
molecules ? even excluding the guest molecule ... clathrate formation in
biological tissues is not an alternative to vitrification, and would
actually be expected to cause more damage than freezing."


Freezing techniques cannot complement vitrification, and neither can
clathrate formation. These techniques are mutually exclusive. I note that in
the xenon clathrate cryostasis paper you cite



that 100 psi (6.8 atmospheres) pressure is used. High pressure methods can
be used to reduce ice formation due to the 9% greater volume of ice over
water, but in this case high pressure is probably mostly to induce the xenon
to form the clathrate. It was once necessary to use 1,000 atmospheres of
pressure with VS4 vitrification solution (higher pressures were too
damaging), until the development of VS41A
(VS4 for 1 atmosphere) vitrification solution.

  The bottom line is that although xenon clathrates may be useful for
cryogenic temperature cryopreservation of cell suspensions and small tissue
samples, it cannot be applied to cryogenic organ cryopreservation or
cryonics. Reduction of cryoprotectant toxicity remains the number one
priority. There are methods that complement vitrification, such as ice
blockers and high pressures, but clathrate formation is not one of these

       -- Ben Best

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