X-Message-Number: 15583
Date: Thu, 08 Feb 2001 13:07:13 -0500
From: Paul Antonik Wakfer <>
Subject: Re: CryoNet #15577 & 15578
References: <>

> Message #15577
> From: 
> Date: Wed, 7 Feb 2001 22:34:35 EST
> Subject: more viability questions
> 
> As previously noted, there are many ways to measure "viability" of tissues
> for various purposes. INC has been using the K/Na ratio, at least in part
> because it appears to be a good predictor of success in transplants of rabbit
> kidneys.

Another partial truth. The major reason is because for the K/Na ratio to
be maintained, major components of the cell must be functioning. (This
has been explained in prior posts.) Its success as a predictor of rabbit
kidney transplant success was simply *supporting* evidence of the worth
of this test. It could not be the primary reason, because the K/Na ratio
test was originally chosen for the rabbit kidney work long before any
kidney work had begun and could not have been known "a priori" to be a
good predictor.
Once again, I ask Mr Ettinger to fairly state the whole truth, weighted
appropriately, instead of a biased version of it.
 
> I have suggested that electrophysiology of the brain may be a better
> criterion for cryonics purposes. 

As I have repeatedly described (and Mr Ettinger has been directly told
by the scientists involved), based on proven brain physiology taught in
basic courses from well-known texts (Guyton - Textbook of Medical
Physiology 8th ed 1991), any tests of electrophysiology must be
secondary to (come after) more comprehensive cellular viability tests
for them to have meaning.

> After all, it is generally believed that we
> "live" in the connections and signals between neurons, with strictly
> housekeeping functions of the cells and tissues secondary and generic.

Only very special kinds of electrophysiology tests will be able to
detect fully intact integrated neural connections and firings. For this
to happen for any length of time, cells will have to be structurally
sound and biochemically alive. A simple result showing nerves capable of
firing shows neither that we have recoverability nor that we are
anywhere near perfected brain suspended animation.
Mr Ettinger here is confusing what attributes/aspects of a brain are
important during life with what attributes/aspects are important for
cryopreservation and restoration of that brain. The two are not exactly
the same.

> Anyway, suppose, on the one hand, that the connections between neurons are
> retained but the internal physiological machinery of the cells fails. On the
> other hand, suppose the opposite--the cells "live" but their connections are
> lost. I submit that the latter case is worse from a cryonics viewpoint.

And I submit that there is no evidence that such a thing is happening or
even likely. Why does Mr Ettinger even consider such a hypothetical and
unreasonable idea for which there is no evidence, unless once more in an
attempt to confuse rather than illuminate?
 
> Now let's look at a paper called "The Influence of Postmortem Delay on Evoked
> Hippocampal Field Potentials in the in-Vitro Slice Preparation," by B.W.
> Leonard et al, Experimental Neurology 113, 373-377, 1991. Paraphrasing some
> key sentences:
> 
> The "5-minute rule" of neurological practice says irreversible brain damage
> occurs after about 5 minures of in-situ (on site or in the patient)
> anoxia/ischemia. This has led to the "universal" belief that hippocampal
> slices should be prepared and put into the in-vitro environment (test tube or
> culture dish etc) as quickly as possible. However, there is reason to believe
> that the in-situ situation could be worse than that in-vitro, because a
> locally damaged circulatory system can contribute to later damage. (We
> reported this many years ago, Hossman & Sato).
> 
> The present study showed that, by a particular electrophysiological
> criterion, for certain types of slices, "viability" was the same for
> postmortem delays of 5 minutes and 30 minutes, and was about half that after
> 3 hours.
> 
> "These data also imply that meaningful electrophysiological information about
> postmortem brain conditions may be inferred from nervous system tissue which
> is not available immediately after death."
> 
> Another encouraging item, it seems to me.

Yes, it is an encouraging result, but since it does not involve either
immersion in a cryoprotectant solution or cooling of any description, it
has little relevance to INC's current reported results or its long-term
goal of perfected brain suspended animation by means of
cryopreservation.

> Message #15578
> Date: Wed, 7 Feb 2001 22:42:39 -0500
> From: <>
> Subject: storage in liquid nitrogen after thousands of years (re: 15572)
> 
> Paul points out in message 15572 that even in liquid nitrogen,
> deterioration takes place after thousands of years.
> 
> I don't want to contest this, and it is arguably conceivable that some
> or perhaps even all current patients won't be revived in 1000 years.
> 
> But i think we can still expect some advances in 1000 years, which is
> a long time to think about the problem, after all.  In particular, i
> think it's reasonable to expect better ways to store patients---perhaps
> in liquid helium, or perhaps there will time stasis or other exotic
> technology.  So if we make it 1000 years, and it looks like it will
> take 10,000 years, i think patients still could be preserved by
> storing them in a new medium.  (Maybe this is even covered in
> Ettinger's first book?)
> 
> I'm not trying to urge complacency here, and any new methods that look
> effective should be investigated as resources permit.  And i think
> everybody appreciates the work being done by INC, 21st Century,
> Alcor, CI, and others to improve suspension methods.
> 
> I just want to claim that concerns about disintegration in liquid
> nitrogen can be reasonably deferred.

Although liquid helium would cause still more cracking damage, Dan's
thought that other methods will come along is certainly correct and I
was not ignoring that.
OTOH, the long-term storage temperature (about -130'C) which will be
best for vitrification (and actually has always been best although not
significantly so before) will enable deterioration at an even faster
rate than LN2 temperature (-196'C).
Still, as Dan says, we can be quite sure that methods will be developed
to decrease the amount of deterioration. 

However, my point to Mr Smith was that any time in storage is *danger
time* for all of several reasons. Therefore, we want the best possible
methods of cryopreservation so that we can come out of this dangerous
situation (totally outside any control of the person in stasis) as soon
as possible after a cure is found for whatever caused the need for
cryopreservation.

Thanks for your reply.

-- Paul --

The Institute for Neural Cryobiology - http://neurocryo.org
A California charitable corporation funding research to
perfect cryopreservation of central nervous system tissue
for neuroscience research & medical repair of the brain.
Voice-mail: 416-968-6291  Fax: 559-663-5511

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