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 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=23440