X-Message-Number: 23440
From: 
Subject: Scientific Evaluation of Cryonics Protocol
Date: Sun, 15 Feb 2004 21:27:37 US/Eastern

  Michael Price carefully laid-out some bait in CryoMsg 23427
to which Charles Platt responded in CryoMsg 23430. Charles'
answer contains some unstated assumptions which have rarely
been discussed -- and perhaps rarely even thought-about. I 
want to bring these assumptions out in the open. 

   A cryonics protocol can be evaluated through animal
experiments. The brains of the animals can be removed and
analyzed by histochemical studies and electron micrographs.
The micrographs can be assayed by counts of neurons, 
neuropil (axons & dendrites) and synapses. Histochemical
analysis can include, for example, LDH (Lactate DeHydrogenase)
for ischemic damage because this stable enzyme is released
when cell membranes break and can be quantitatively assayed.
All metrics can be compared to the brains of a control group 
of animals who had not been subjected to the cryonics protocol.

   Comparison of cryonics protocols would be done 
similarly: one group of animals given one cryoprotectant
and another group given another cryoprotectant. Or one
group given an anti-ischemic cocktail along with CPS
(Cardio-Pulmonary Support) & cooling whereas the other group 
only receives CPS & cooling before perfusion. 

   How can the results be evaluated? How do counts of 
neurons, neuropil & synapses plus histological assays map to
preservation of personal identity & cognitive capacity? Where
damage is detected in the animals undergoing the protocol,
what damage is reparable by future science and what damage
is not reparable?

    In cryonics we must rely on indirect scientific 
evidence to assess damage. We cannot predict what future
science can repair or reconstruct. It seems prudent to 
minimize damage, but damage can be difficult to quantify
and the costs of reduction may be high. There may be 
thresholds of damage separating what future science can 
repair and what it cannot. But the future is unlimited --
what seems irreparable in 50 years may prove to be reparable
or replaceable in 100 years.

   Currently work is being done by CI & 21CM to evaluate
cryoprotectant protocols on animals. No one is evaluating
anti-ischemic protocols on animals. Suspended Animation has
a mandate to do such work, but has been thwarted -- despite
pleas that only rodents & previously-killed dogs would be used.

   The last substantial cryonics-related ischemic work done
was the demonstration (by Mike Darwin & Steve Harris) that 
dogs could recover from 17 minutes of normothermic ischemia
by the application of CCR meds. I believe that this does prove 
that CCR meds can reduce ischemic damage. But *how much*
benefit are anti-ischemic meds to a cryonics patient who has been 
given immediate CPS & cooldown? If CPS & cooldown are effective 
enough there should be *no* ischemic damage -- meaning that
anti-ischemic meds are useless or worse than useless if they 
interfere with optimum application of CPS & cooldown. That kind 
of treatment cannot be compared to 17 minutes of warm ischemia.

   Although cooldown may be enough to compensate for the
poor circulation delivered by poor CPS, if some ischemic
damage is caused, *how much* ischemic damage is caused? If
the damage is miniscule or more easily repaired than 
freezing damage, it should not be a concern. It has been
an article of faith among many cryonicists that freezing
damage can be repaired by future science, but ischemic 
damage is irreparable. I believe that the ischemic damage
experienced during good CPS & cooldown would be easily 
repaired. Cells experiencing ATP levels less than 15% of 
normal die of necrosis in a matter of hours at room 
temperature. Cells experiencing ATP levels 25% to 75% of 
normal die of apoptosis in a matter of very many hours --
or more often days -- at room temperature. I believe that
future science will be able to intervene in the path of 
cell death by necrosis & apoptosis if these processes are
halted by cryopreservation. "Irreversible" cell death is an
artifact of current technology. 

  ( For more details and scientific references, see my
    essay "Ischemia and Reperfusion Injury in Cryonics"
     http://www.benbest.com/cryonics/ischemia.html )

   Anti-ischemic meds do a great deal of psychological damage
-- possibly greatly outweighing the benefits. Local groups
have the potential to be invaluable in cryonics emergencies
-- for which traveling teams many miles away may not help. No
aspect of cryonics rescue intimidates potential local group
members more than anti-ischemic meds. Local group members do
not know what to include in a homemade kit and cannot afford
to pay a huge fee for a pre-packaged one. And they are 
intimidated about the means to administer the meds. So even
if prompt CPS & cooling could provide most -- if not all --
of the anti-ischemic benefit, local group members are left
feeling helpless & useless -- feeling if a traveling team
does not arrive there is nothing that can be done. 

   Charles should not take the fact that CI cases have been 
poorly documented as evidence that good cooldown & CPS 
support has never been given to CI patients. Mae Ettinger
had the benefit of bedside response with a Michigan Instruments
thumper. And there are other cases. But my focus is on the future.

   I despise the hostility I often see between Alcor members 
& CI members and I am committed to neutralizing this
hostility. I applaud Alcor for the work that they do. I 
believe that good technology need not be expensive technology
and I am committed to improving CI services without raising
costs. I am expecting significant advances in CI technology
in the near future and beyond. I believe cryonics will more
advance by Alcor & CI concentrating their energies on 
improving service through different strategies than by 
spending energy trying to destroy the other organization. 

                 -- Ben Best

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