X-Message-Number: 2940
Date: 25 Jul 94 00:52:13 EDT
From: Mike Darwin <>
Subject: SCI.CRYONICS Cardwell carping
I am going to do something I generally hate seeing done: quote a previous post
almost in entirety in order to respond to it. I am doing this because the post
is a rude one and is laced with hostility. I do not wish to be accused to
distorting what was said or how it was said, thuis I reproduce it almost in
full.
>>The more experience I get with "undercapitalized" groups of volunteers in
remote
>>areas (i.e., cut off from mainstream cryonics technology) the more I am coming
>>to conclude that their VERY BEST strategy is to:
>
>>a) Get a PIB (portable ice bath) and Squid (water pump cooling unit)
>>b) build a dry ice box.
>>c) cool the patient on ice ASAP and them FREEZE him/her in dry ice ASAP and
ship
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>to wherever for storage.
>
>>As to the rest of the small groups (in the US and Canada) I think their very
...
>Which is interesting, in light of your comments in another thread, in
>message #2907, where you were discussing the effects of varying glycerol
>concentration:>
...
>>And incidentally, I also have a collection of EM's from straight frozen brains
>>and brains frozen with low concentrations of glycerol. If you think that's
the
>>better approach, forget it! A tissue homogenate *is* the operative
description
>>in these cases (at least after thawing -- an important caveat).
>So, you refer here to evidence that straight freezing of the brain
>produces "a tissue homogenate" (and opining that we should "forget it" as
>the best approach) while in the earlier message you make the categorical
>statement that the "very best" strategy for remote groups is to straight
freeze. Huh?>
>Be that as it may, you changed direction in message #2855, where you
>wrote:
>>After thinking about the Australian Group's situation in light of what Robert
>>has said about their capabilities I would like to add the following thoughts.
>And you then suggest perfusion via the carotids.
>Finally, after I pointed out the glaring disparity between statements by
>yourself and Steve Harris on the value of carotid perfusion, you wrote in
>message #2906:**
...
>>One of things I regretted after posting my message was that I didn't weigh in
>print more carefully the tradeoffs. Yes, there are *very* good reasons for
>>using the aortic root when you can. But, and this was my point, you may not
>>always be able to do that without paying some other kind of price which may be
>>higher. Tough choices, huh?
>Actually, what you did not do, at the beginning of this thread, was to
>avoid making that sweeping and ill-considered statement, apparently borne
>of ignorance and prejudice, suggesting straight freezing as the best
>strategy for certain people. First, get your facts straight about the
>people and situations you are commenting upon, Mike; only then is it
>appropriate to speak of "tradeoffs."**
Let's take it one step at a time:
1) First lets talk about apples not organges. *You* started out by claiming I
was secretly talking about Australia. I was not. My advice was *not*
predicated on your situation. *You* then proceeded to tell me how you were
capable of doing a washout and good stabilization. *That* information then
changed the advice I gave to you. If you have these capabilities and can deal
with all the associated logistic problems, then you are *not* the kind of group
I was talking about. But then I never said you were. In fact, I never said
anything about Australia until *you* inserted yourself into the discussion.
What I had in mind was advising three other groups of people in situations very
different from yours. As to how good your situation will turn out, I have quite
politely refused to give an opinion. Your nasty attitude is wearing my
politeness rather thin.
As to my comments about straight freezing, they are distorted and out of
context. I said that EMs of straight frozen AND THAWED AND FIXED AND SECTIONED
tissue give the appearance of a tissue homogenate. In any contest between
glycerolizing and straight freezing using these criteria glycerolization wins.
And that is what I was speaking to. However, in a situation of long postmortem
delay we are not talking about a simple case of glycerolization vs. straight
freezing. We are talking instead about a third added variable: autolysis. I
have had the opportunity on three occassions now to examine post mortem brain
24-48 hours after legal death at temperatures in the 4-8C range. If you want
autolysis you can see plenty of it. And what you see there isn't something
giving the appearance of a tissue homogenate, it just patchy areas where there
is nothing but (at the EM level) amprphous debris. At the light level what you
see is steadily decreasing cell counts -- just holes in the neuropil. Greg Fahy
and I presented the data from the first human case at the Tahoe Festival.
Contact Alcor for copies of these tapes. We also did extensive dog work at
normothermia looking at ischemic changes versus time delay -- that was
reported there as well.
Personally, if I was given a choice between a long delay and quick freezing, I'd
take quick freezing. As I pointed out in my message which you quoted I was
quite careful to qualify my description of straight frozen-thawed brain tissue
as having this appearance "after thawing -- an important caveat." It's
important because thawing means at least that a) the tissue has been disturbed
(stirred) by ice melting, water reabsortion, etc)., b) the tissue has been
disturbed by cutting to allow for fixation (and cutting after it has been
profoundly injured by freezing so that any "cutting" done by freezing is now
compounded by the stirrring associated with the sectioning to achieve
fixation!), c) freezing probably alters the tissue's chemistry enough to alter
its response to fixation, therefore the tissue may not fix as well and you may
loose more structure due to poor fixation/immobilization of the structure when
it is sectioned., d) you have diffusion driven changes that can go on during
fixation (which is not an instaneous process) and after freezing.
What am I trying to say here? Simply that thawing, fixation, multiple
sectioning, etc. introduce the possibility, no, the probability of stirring
things up such that things that were formerly inferrable, are no longer so.
Even still, the pieces following straight freezing are likely to be larger,
closely related to each other and more easily identifiable -- *in the frozen
state.*
Autolysis is another matter altogether. The pieces are likely to be small,
indiscrete, and scattered by diffusion. Enzymes chop things into *small*
pieces. Almost certainly smaller pieces than freezing injury does. And
diffusion *scatters them.* Thus we are comparing apples and organges.
Choices such as these must be made in the context of the situation. Each
person/organization has to make their own choices. I stated my opinion. It may
not be the best approach. It may not even be compatible with revival. But I
did not state it lightly or thoughtlessly. And the bottom line is that these
questions won't be answered by these kinds of debates but by two things:
research in the laboratory and the march of technology.
Finally, I do not resent your questions, I resent your nasty, blaming tone:
<<Actually, what you did not do, at the beginning of this thread, was to
avoid making that sweeping and ill-considered statement, apparently borne
of ignorance and prejudice, suggesting straight freezing as the best
strategy for certain people. First, get your facts straight about the
people and situations you are commenting upon, Mike; only then is it
appropriate to speak of "tradeoffs.">>
My remarks have been carefully considered, and I am not afraid to modify my
stance on the basis of fresh of information, or even to state I'm wrong when I
find myself to be so. I have no interest in trading insults with you. When you
learn to extend the basic courtesy of not presuming someone whom you are engaged
in a dialogue with to be a cur, especially when that someone has taken a
considerable amount of time to deal with your questions pleasantly and
thoughtfully, you will find life a lot easier.
In short: "First, get your facts straight about the people and situations you
are commenting upon, Robert; only then is it appropriate to speak of them of
making sweeping and ill-considered statements, apparently borne of ignorance
and prejudice."
Mike Darwin
Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2940