Xref: info.physics.utoronto.ca news.answers:30049 sci.answers:1633 sci.cryonics:1790 Subje

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Xref: info.physics.utoronto.ca news.answers:30049 sci.answers:1633 sci.cryonics:1790 Path: cantaloupe.srv.cs.cmu.edu!tsf From: tsf+@cs.cmu.edu (Timothy Freeman) Newsgroups: sci.cryonics,news.answers,sci.answers Subject: Cryonics FAQ 2: Science/Technology Supersedes: Followup-To: sci.cryonics Date: 1 Oct 1994 07:02:05 GMT Organization: Carnegie-Mellon University, School of Computer Science Lines: 265 Approved: news-answers-request@MIT.Edu Expires: 14 Nov 1994 07:01:42 GMT Message-ID: References: NNTP-Posting-Host: pop.cs.cmu.edu Summary: This posting contains a list of Frequently Asked Questions and their answers about cryonics, the practice of carefully preserving very recently clinically and legally dead people in hopes that they can be revived in the future. It should be read by anyone interested in posting to sci.cryonics and by anyone who finds the prospect of certain death irritating. Archive-name: cryonics-faq/part2 Cryonics Frequently Asked Question List Section 2: Science/Technology Last Modified Mon Jun 21 14:05:59 1993 (You can fetch cryomsg "n" by sending mail to kqb@whscad1.att.com or to kevin.q.brown@att.com with the subject line "CRYOMSG n". There is more about this in the answer to question 8-2. The index to this FAQ list is cryomsg "0018.1". ) Copyright 1993 by Tim Freeman. See the end of Section 1 for restrictions on redistribution. 2-1. Has anyone been successfully revived from cryonic suspension? No. Fortunately, successful cryonics is a two-step process: (1) put the patient in suspension and (2) revive the patient from suspension. For cryonic suspension to be worthwhile, we only need to master step (1) right now and have reasonable expectation that we might master step (2) later. 2-2. What advances need to be made before people frozen now have a chance of being revived? A number of advances in basic areas of research such as medicine, microbiology, engineering, and information sciences are required before any serious attempt can be made to revive patients suspended with current technology. Nanotechnology, the design and fabrication of molecular scale machines, is an emerging technology that will probably be both necessary and sufficient for revival. 2-3. Is there any government or university supported research on cryonics specifically? There was suspended animation research sponsored by NASA as late as 1979 at the University of Louisville, Kentucky. 2-4. What is the procedure for freezing people? Read an account of a cryonic suspension. Briefly, circulation is restored by CPR, and the blood is replaced by other substances that prevent blood clots and bacteria growth and decrease freezing damage. As this happens the body is cooled as quickly as possible to slightly above 0 degrees C. After the blood has been replaced the body is cooled more slowly to liquid nitrogen temperatures. 2-5. How can one get a more detailed account of a suspension? Cryomsgs 601 and 602 are The Transport of Patient A-1312 (28K bytes) and cryomsgs 696, 697, and 698 are The Neurosuspension of Patient A-1260. (35K bytes). These messages give a first-hand description of the initial stages of two suspensions. 2-6. Is there damage from oxygen deprivation during a suspension? Not if the suspension happens under good circumstances. One of the big goals of the suspension procedure is to get the heart and lung resuscitation (HLR) machine onto the patient as soon as possible, to prevent this damage. The barbiturates they give reduce brain metabolism, as does cooling. In a well done suspension, the damage from oxygen deprivation should be minor. In a more perfect world, the suspension procedure would be able to start before legal death, which should reduce the damage from ischemia even more because there wouldn't be any time when the heart is stopped and the body is warm. 2-7. Do memories require an ongoing metabolism to support them, like RAM in a computer? No. Here's a relevant quote, supplied by Brian Wowk: We know that secondary memory does not depend on continued activity of the nervous system, because the brain can be *totally inactivated* (emphasis added) by cooling, by general anesthesia, by hypoxia, by ischemia, or by any method and yet secondary memories that have been previously stored are still retained when the brain becomes active once again. Textbook of Medical Physiology, Arthur C. Guyton, W.B. Saunders Company, Philadelphia, 1986 Thomas Donaldson says that brain waves of supercooled small animals have been measured, and there are none, even though the animals still have their memories after they are rewarmed. He cites AU Smith, ed. BIOLOGICAL EFFECTS OF FREEZING AND SUPERCOOLING, London, 1961; article by Aubrey Smith herself, "Revival of mammals from body temperatures below zero", pp. 304-368. 2-8. If these frozen people are revived, will it be easy to cure them of whatever disease made them clinically die? Repairing the freezing damage looks much harder than curing any existing disease, so if revival is possible then curing the disease ought to be trivial. This doesn't include diseases that lose information in the brain, such as Alzheimer's, mental retardation, or brain tumors; in these cases, even if the disease were cured and the person revived, the problem of replacing the lost information looks hard. 2-9. If I'm frozen and then successfully revived, will my body be old? No. Old age is a disease that ought to be easier to cure than the freezing damage. 2-10. Why is freezing in liquid nitrogen better than other kinds of preservation, such as drying or embalming? Straightforward chemical arguments lead to the conclusion that significant amounts of decomposition do not occur at liquid nitrogen temperatures. (See Hugh Hixon's article "How Cold Is Cold Enough?" from *Cryonics* magazine, January, 1985, or fetch cryomsg 0015.) This isn't true for either dried or embalmed tissue kept at room temperature. Also, Alcor and Trans Time have done experiments with dogs that demonstrate that part of the suspension process does not cause damage. Dogs have been anesthetized, perfused with a blood substitute, and cooled to slightly above 0 C for several hours. After rewarming and replacing the original blood, the dogs revived with no obvious brain damage. Experiments like this cannot be done with drying or embalming. Another option that may become possible in the future is vitrification. 2-11. What is vitrification? (Next paragraph copied from CRYOMSG 6 posted by Kevin Brown) The cover article of the Aug. 29, 1987 issue of Science News describes vitrification, which achieves cooling to a glassy state without the water crystallizing into ice. The advantage of this is that the cells do not suffer the mechanical damage from the crystallization. The main disadvantage is that the concentration of cryoprotectants required to achieve this is toxic. It is also, currently, a technically difficult and expensive process requiring computer control of cooling rates, perfusion, etc. The March, 1988 issue of Cryonics magazine ("The Future of Medicine", Part 2 of 2) suggests that vitrification may not be needed for ordinary organ banking, since other, cheaper methods may be good enough. For tissues and cells, though, it has a lot of promise for the commercial market. Thus, commercial research into vitrification may stop short of what is needed for making it viable for preservation of large organs or whole bodies required by cryonics. 2-12. How is the baboon? Did it live? Any brain damage? According to Art Quaife as of 14 Jul 92, the baboon is well and has no signs of brain damage. This is part of what CRYOMSG 865 posted by Art Quaife has to say about the baboon: Berkeley, California, May 29 1992. BioTime Inc. has, for the first time, successfully revived a baboon following a procedure in which the animal's deep body temperature was lowered to near-freezing and its blood was replaced with BioTime's patent-pending blood- substitute solution. The animal was anesthetized, immersed in ice and cooled to below 2 degrees Celsius, using the BioTime solution with cardiopulmonary bypass procedures. After being bloodless and below 10 degrees Centigrade for 55 minutes, the animal was rewarmed and revived. The baboon is presently under study by BioTime scientists to determine any long-term physical effects. The company intends to conduct further experiments on primates, using its blood-substitute solutions. 2-13. Who has successfully kept dogs cold for hours? Did they survive? Any brain damage? Several people have achieved that. The first cryonics organization to do so was Alcor, in the mid 1980's. For example, the Jan. 1986 issue of Cryonics magazine describes, in the article "Dixie's Rebirthday", a German Shepherd dog named Dixie who "experienced the privilege (and the peril) of having all her blood washed out and replaced with a synthetic solution and then being cooled to 4 C. For four hours she was held at this temperature: stiff, cold, with eyes flattened out, brain waves stopped, and heart stilled. Then, she was reperfused with blood, warmed up and restored to life and health." She made a total recovery. Several variations, with different perfusates and slightly different temperatures and/or times were also performed by Alcor. Later, ACS performed a similar experiment on a beagle named Miles and recently (1992) BioTime successfully cooled and revived a baboon. In comparison, hypothermic cardiac surgery was pioneered on humans decades ago, although the temperatures used were not nearly as low as in the dog experiments above. More recently, the October 1988 issue of The Immortalist described successful surgery on a brain aneurysm in which the patient was cooled to 15 C for almost an hour. During that time the patient's blood remained drained from the body, there was no respiration, the heart did not beat, and the brain barely functioned. 2-14. Who froze the roundworms? What happened? (This text is quoted with slight modifications from CRYOMSG 790 posted by Charles Platt) Gerry Arthus, Alcor New York's Coordinator, has announced preliminary results of an experiment which was designed to investigate whether memories will survive cryonic suspension. For his experiment, Gerry used Caenorhabditis elegans, a nematode (tiny worm) that's one of the simplest living creatures. It has a complete nervous system, however, and can be "trained" in a rudimentary way. Worms that are raised in a warm environment will "remember" it and will prefer it if they are given the choice. Conversely, worms that were raised in a cooler area will tend to prefer that environment. Gerry placed a small number of worms in a cryoprotective solution and froze them to -80 degrees Celsius for two hours. After he revived the worms, the ones that survived the experience still "remembered" their former environmental preferences. So far as we know, this is the world's first experiment designed to verify that memory is chemically encoded and will survive the freezing process. The sample that Gerry used is too small to prove anything conclusively. Soon, however, Gerry hopes to repeat the experiment with a larger sample. He also intends to devise tests to eliminate the possibility that the worms changed physiologically to adapt themselves to warmer or cooler environments. 2-15. What were the circumstances under which cat brains produced normal-looking brain waves after being frozen? This was reported by I. Suda and A.C. Kito in Nature, 212, 268-270 (1966). The cat brains were perfused with 15% glycerol and cooled to -20 C for five days and, upon rewarming and perfusion with fresh blood, showed normal brain function (as measured by EEG). Since this experiment was done so long ago, and technology has improved considerably since then, there is some interest in redoing these experiments to see how well we can do now. The April 1992 Cryonics, volume 13 number 4 page 4, talks more about this and gives more references. Appendix B of CRFT talks about the plausibility of repair in general. 2-16. Would it be possible to use some improvement on modern CAT or MRI scanners to infer enough about the structure of a brain to reconstruct the memories and personality? This was discussed on the cryonics mailing list some time back. The conclusion was that using radiation to infer the structure of the neurons in a brain in a reasonable amount of time would require enough radiation to vaporize that brain. Then the discussion moved on to nuclear-bomb x-ray holography devices in outer space that record the results on film that has to be moving by at an astronomical speed so it doesn't get caught in the blast. Cremation and immortality, all in one convenient package. I find nanotechnology-based approaches more believable, albeit less spectacular. To read about this yourself, fetch articles from the cryonet archive with the words "brain scan" in the subject. There are 18 as of July 30, 1992. See the "What is a cryomsg?" question, number 8-2. 2-17. Does background radiation cause significant damage to suspendees? No. Ralph Merkle addresses this in in the cryonet archive, message 558. He estimates that background radiation should not be an issue for at least 50,000 years of storage. See question 8-2 for instructions on how to fetch this.

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