X-Message-Number: 2917 From: Date: Tue, 19 Jul 94 12:31:07 EDT Subject: CRYONICS discussion There are several reasons why in years past I often didn't pay close attention to the various reports on suspension procedures. First, my impression was that the activity was often frenetic and impulsive, with not infrequent reversals of field. (e.g. glycerol to DMSO and back to glycerol.) This is not to denigrate the heroic efforts of Jerry, Mike, and others, but we have to strike a balance. Second, we not infrequently found reports (including the standard literature) to be confusing/confused, incomplete, or just plain wrong. Indeed, Mike Darwin sometimes advised everyone to rely only on his own experience--not bad advice sometimes. Over all, it was just the usual cost/benefit estimate. No procedure was even claimed to produce assured significant benefits at the bottom line, so why divert much badly needed resources of time and effort? The situation is a little different now. Among other things, the Cryonics Institute now has more resources and expects soon to have a new building, so we can do more. We expect eventually probably to offer a full line of options in-house, from the most expensive to the least expensive. (But we will probably also continue to offer out-sourced options, for a variety of reasons.) We are still very much disinclined to chase the latest expensive fad on slim evidence of ultimate benefit, but we will seriously consider all reasonable possibilities. We also hope to benefit (along with others) from the work and unbiased opinions of the European scientists. And, with a higher profile and more active recruiting, we hope to have more of our own people available and competent. As to Dr. Harris' comments on tradeoffs and cooling rates, we are glad to have this input. The answer to his question is that we do NOT take a long time at the freezing plateau, even though we take a full week to cool to dry ice temperature (7 days with human patients--5 days for sheep heads). To get the patient well into the sub-zero Centigrade range takes only about 8 hours. And I repeat that the results, from our own naked eye observations, are good; the Ukrainian work will soon tell us whether results are good at the finer structure level. (Incidentally, the August IMMORTALIST, being mailed tomorrow, is slightly unclear or misleading at one point, unfortunately. In commenting on the Ukrainian report on early phases, and the preliminary report of the next phase, I may have given the impression that they have already completed the full procedure. Actually, as the report itself makes clear, the latest completed phase, soon to be reported in detail, is just freeze-thaw WITHOUT perfusion, to establish another base line. The final work will be completed and reported later, and may answer some important questions.) I also note that Mike Darwin's pessimism about autolysis does not seem to be shared by Ralph Merkle. Further, Greg Fahy's affidavit (1988) contains references to considerable work suggesting that brains do NOT deteriorate under warm ischemia as rapidly or badly as Mike seems to think. With both humans and other mammals, even after several hours of warm ischemia, followed by freezing and thawing, many indices of physiological activity are rather good, and often histology also. Further, I again note that children have reportedly made complete recoveries after nearly an hour of ischemia under cold water--but at body temperatures far above freezing. This suggests to me very strongly that deterioration is not--or at the very least not always--rapid or catastrophic. Finally, I suggest that "Smith's Criterion" is a very weak reed on which to lean. For one thing, surviving 60% ice under her conditions is very different from surviving 60% ice after cryogenic storage. On the other side, "survival" by her criteria could easily be too strict a condition to warrant sacrifice of other considerations. Robert Ettinger Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2917