X-Message-Number: 12180
Date: Fri, 23 Jul 1999 21:04:38 EDT
Subject: addendum

In my earlier post today there was this:

[Doug Skrecky said]
>>Dehydrating a brain during shipment in an concentrated  cryoprotectant bath 
>>would effectively reduce storage costs by shrinking the brain volume. A 
further >>benefit here could be cheap vitrification, with potentially far 
superior preservation of >>cellular structure during freezing.
[I said]
>Whether dehydration or/and vitrification should be done will be decided 
primarily on >the basis of effectiveness in minimizing damage that may be 
difficult to reverse, not >on the basis of storage cost.

This should have been clarified. It might indeed--depending on results of 
future experiments--be decided that we should offer cheaper methods (possibly 
some combination of freezing, drying, and chemical fixation), even if those 
methods are not the best available, or even second best, since some chance is 
better than none and some people cannot afford much. But for front-line 
procedures, storage cost must take a back seat to effectiveness.

In passing, I might also note Doug's mention of "cellular structure." This is 
not usually the main issue. Freezing damage is a complex subject, still not 
fully understood; but "cellular damage" (inside the cells) is not usually the 
chief culprit, as is obvious not only on a theoretical basis but from the 
many observations that often cells can be cultured, or otherwise shown to be 
viable, from frozen/thawed tissues or organs, even though the tissues or 
organs themselves are not viable. It is often the connectivity between cells 
that is vulnerable, and this is thought to be especially true in the brain, 
where neuron connectivity may underly memory and other brain phenomena. (I 
know Doug knows all that, but newcomers may not.)

What is sometimes not fully recognized is that the facts above offer 
additional support for optimism. I can't take the space or time to go into 
this much, but--for example--if some cell connections are missing and some 
present, the ones present can provide information about the ones missing, or 
clues to ways to recover the information needed.

Robert Ettinger
Cryonics Institute
Immortalist Society

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