X-Message-Number: 9453 Date: Sat, 11 Apr 1998 15:50:54 -0400 (EDT) From: Charles Platt <> Subject: Basic Cryobiology Let us go back to the basics: "Freezing of living cells: mechanisms and implications" by Peter Mazur at Oak Ridge National Laboratory, copyright 1984 by the American Physiological Society, available as a reprint from Alcor. This summarizes more than two decades of knowledge of cryobiology. Citing 126 references, it confirms beyond reasonable doubt: 1. If you introduce a high concentration of perfusate without increasing the concentration gradually, you are very likely to inflict severe osmotic damage. 2. If you freeze perfused tissue slowly, you allow larger ice crystals to form and inflict toxicity from high concentrations of salts remaining in the cells. In an earlier post I spelled out these facts extremely clearly and asked why The Cryonics Institute uses a protocol that flouts these basic principles with potentially severe consequences. In response, Bob Ettinger simply claims that his methods produce good results. This places him at odds with 30 years of accumulated knowledge in cryobiology, derived from thousands of experiments. To support his claim, he cites one source: the light and electron micrographs produced by Pichugin. I have already noted that when these micrographs were shown to a leading cryobiologist, he was dismayed by the obvious amount of damage. I saw the damage myself: large ice holes, capillary tears, and scrambled brain tissue. Most of these problems could be avoided or minimized with better technique. When the micrographs were shown to neurobiologists, they were unable even to identify the tissue. I believe a note was attached to the micrographs from Pichugin, stating in fact that he did use incrementally increasing glycerol concentrations. If this wasn't stated in CI's magazine, the only way to settle the matter is by contacting Pichugin directly. I plan to do this. But, since the results achieved by his protocol showed severe amounts of damage either way, it doesn't really matter whether the protocol was better than, or the same as, the protocol used by CI on human patients. It simply did not work very well. I invite Bob to compare, for himself, Pichugin's micrographs with those that we published in CryoCare Report, showing results achieved by properly controlled perfusion. I will be glad to send him a copy of the newsletter if he does not have one already. I don't expect Bob to change his outlook, because this is not the first time he has placed himself in opposition to all established knowledge in a field of science. For example, he continues to defend Olga Visser. But when he claims that an uncontrolled, unmonitored, uncalibrated open-circuit perfusion with 75 percent (v/v) glycerol can produce results equivalent to those of the most advanced research being done today, surely someone has to point out that this is optimism taken beyond reasonable limits. It is _simply not true._ I realize that Bob is much loved in the cryonics community, and any upstart who challenges his procedures at CI is like a guest on a talk show accusing the host of child abuse. It's not a cool thing to do. The audience will boo. But I believe that the statements I have made above are beyond dispute. ----- Regarding the general probability of cryonics patients being resuscitated, I am aware of Bob's views on this, but for the record, I believe (for example) the probability of eventual FDA regulation is far greater than .78, and I believe damage repair in many patients may have a probability of zero. But why go through all this again? It has been discussed inconclusively at great length (e.g. "Will Cryonics Work?" by Steven B. Harris in _Cryonics_ magazine, May 1989, which suggested overall probability of success somewhere between .0023 and .15). This is the kind of topic that cryonicists love, because a) no ultimate proof or disproof is possible, b) anyone's opinion is as good as anyone else's, regardless of professional qualifications, and c) it encourages us to forget the problems of the present and daydream about the future. This is precisely the opposite intention of my original post. --Charles Platt, CryoCare Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9453