X-Message-Number: 10378
Date: Thu, 3 Sep 1998 17:45:27 -0400 (EDT)
From: Charles Platt <>
Subject: Suda etc.

 To Robert Ettinger:
Suda's experiment certainly is relevant to the discussion, 
because it is the only one I know of, in the history of 
cryobiology, where a serious and well-controlled attempt was 
made to measure function of a whole mammalian brain after 
freezing and thawing. All of my cryonics reference materials 
are still sealed in boxes following my relocation from New 
York to Arizona, but I believe my memory of the experiment is 
accurate. The cat brains were perfused with a glycerol 
solution under optimal conditions, in that the "patients" did 
not experience ischemic downtime and did not suffer prolonged 
pre-mortem periods of reduced blood flow and diminished 
supply of oxygen, as is usually the case in cryonics patients 
who die "naturally." Suda's glycerol solution was, I believe, 
ramped up to mitigate osmotic shock, and the concentration 
was accurately measured. Again, this is far better treatment 
than is experienced by some cryonics patients, even today, as
you well know.
Suda's solution was sufficiently concentrated, according to 
one cryobiologist, that there is some doubt whether the 
remaining water really froze at all in brains that were not 
taken all the way down to dry-ice temperature. So, what we 
have here is a MOST FAVORABLE scenario--far LESS potentially 
damaging than the treatment experienced by cryonics patients 
in the 1980s who experienced periods of ischemia before being 
frozen at liquid nitrogen temperature. Yet upon rewarming, 
function in Suda's cat brains ceased because of structural 
damage (among other factors). 
Now, it may be debatable whether those brains resembled 
"hamburger," and whether it was proper or improper for a 
scientist to use this term. What is unarguable, however, is 
that although white-light microscopy may reveal relatively 
little obvious damage, electron micrographs show very clearly 
that the ultrastructure suffers SEVERE damage when brain 
tissue is frozen using cryoprotective protocol that was 
current in the 1980s. 
I ask you once again: Have you looked at these pictures? Some 
were shown at the Alcor Technology Conference, in 
presentations which, as I recall, you chose not to attend. 
Others were published in our own newsletter, CryoCare Report. 
I have offered to send you a copy. You will find obvious ice 
holes (empty areas resulting from the growth of intercellular 
ice), torn capillary beds, severed dendrites, and other 
damage. Maybe the result looks more like beef stew than 
hamburger, but either way, it's the kind of thing that I 
believe Rowe was talking about, and I think it justifies his 
statement AT THE TIME HE MADE IT. Today, I believe we can do 
much better, and research is moving us rapidly toward 
techniques that will result in excellent cryopreservation. 
I believe that all cryonics activists were to some extent 
deluding themselves before Fahy's electron micrographs were 
first made available in the 1980s. This was nothing to be 
ashamed of; better data simply weren't available. But the 
same is not true today. The pictures do exist for anyone who 
wants to look at them. 
Incidentally, for those not familiar with it, Suda's remarkable 
paper was published in Nature, I believe in the October 15, 
1966 issue. I was able to obtain a copy from a medical library. 
I seem to recall that Alcor offers reprints. The CryoCare 
Report back issue, showing pictures of tissue damage that I 
refer to above, is available from me free of charge, to anyone 
who sends me a street address. 
--Charles Platt 

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