X-Message-Number: 29217 From: "Mark Plus" <> Subject: Suspending Life: The Science of Cryonics Date: Fri, 02 Mar 2007 14:51:17 -0800 http://www.firstscience.com/home/index2.php?option=com_content&task=view&id=14148&Itemid=71&pop=1 or, http://tinyurl.com/ywzb82 Suspending Life: The Science of Cryonics By Jen Schripsema Moments after death, some people are being preserved in very cold conditions with the hopes that future technology will be able to bring them back to life. Is this scientifically possible? Freezing people only to revive them at a later date is a good plot device for movies such as Idiocracy, Austin Powers, or Forever Young. It may sound like science fiction but in fact over 140 people, including famous baseball player Ted Williams, have already been preserved using a technique called cryonics, where human bodies are cooled to extremely low temperatures and stored in the hope that future technology will bring them back to life. But how does cryonics actually work? Or, according to many scientists, not work? Preserving bodies Supporters of cryonics are primarily concerned with preserving a person's identity, thoughts and memories which are physically stored in the brain, under the assumption that in the future it will be possible to regrow' a new body. Therefore, at the Alcor Life Extension Foundation and the Cryonics Institute, the two biggest organizations that provide this service, people can choose to have either their entire body or only their head preserved. But cryonically preserving a body, or a brain, after death doesn't actually involve freezing at least not anymore. The problem with freezing is that the structure and growth of ice crystals in cells is very damaging anyone who has eaten dried-out food damaged by freezer burn has direct experience with the destructive effects of ice crystals. To avoid ice formation, cryonics has been moving towards a process called vitrification. To vitrify a body, a machine replaces blood with a solution containing a high concentration of chemicals called cryoprotectants that chill the body while preventing ice formation. As cryobiologist Kenneth Storey from Carleton University in Canada explains, the secret lies in the extreme speed with which tissues can be cooled to extremely low temperatures. If you change the temperature of a solution very, very fast 5000 to 10,000 degrees Celsius a minute that solution will actually just stop in place. The water molecules don't have time to form the rigid crystalline structure of ice, but instead maintain a fairly random arrangement that is referred to as a glass-like state. After vitrification, cryonics labs suspend people in liquid nitrogen at temperatures below -180 degrees C. Vitrification is a scientifically sound process - Storey uses it in his own research on freeze-tolerant animals. But he doesn't agree that the process can be used successfully to preserve people and then have them come back to their original state. You can vitrify a single human cell and have it come back. You can even vitrify sheets of human cells, so long as they are only one or two cells thick, and have them come back. But you can't vitrify a huge human organ; they are too big, they are too complicated, and you cannot change their temperature fast enough, says Storey. The Alcor Life Extension Foundation and the Cryonics Institute disagree. The Alcor website states: Vitrification can happen on any scale at any cooling rate if enough water is replaced by cryoprotectant. Prior to 2001, Alcor used glycerol to prevent ice formation but like most cryoprotectants, it is quite toxic at room temperature. They are now using a mixture of two different cryoprotectants which is less potent. The big thaw Even if an entire organ is successfully vitrified, thawing it out is likely to cause damage due to recrystallization. Tiny ice crystals that form around 0 degrees C get bigger and bigger and bigger, says Storey. He studies animals like the wood frog that live in very cold climates and reach a deep, frozen state of hibernation to survive the winter. The liver of these animals makes glucose, a cryoprotectant, which is circulated to cells so that ice doesn't form inside them. Subsequently, their blood circulation ceases, their hearts stop and they have no detectable brain activity for weeks, but when it's time to thaw out, they regain all their vital functions within hours. But these animals have several adaptations to deal with freezing temperatures that humans just don't have. They can turn on various genes that make special proteins to help cells deal with the stress of freezing and thawing. To genetically engineer all those mechanisms would be an infinitely difficult problem, says Storey. However, proponents of cryonics believe that future technologies will provide answers to all of the problems introduced during vitrification and thawing, not to mention curing the health problems that led to the death of the preserved body in the first place. Cryonicists have been envisioning cell repair augmentation by drugs, synthetic enzymes, viruses, and macrophages since the 1960s, states the Alcor website. Today, hope lies in the field of nanomedicine - using microscopic devices to treat disease. Other cryonics experts are not convinced. As a scientist, while no one ever says this is impossible, the probability is extremely low partly because of the complexity involved when cells and tissues deal with freezing and partly because of what we don't know, says John Baust, the director of the Institute of Biomedical Technology at Binghamton University in New York state. Many scientists believe that relying on future technology to solve problems places cryonics outside the scope of science and into the realm of faith or religion. Cryonics as it stands is not bad or evil, but it's not scientific. It's a faith-based initiative, says Storey. For more information: Alcor Life Extension Foundation http://www.alcor.org/ Kenneth Storey's Lab at Carleton University http://http-server.carleton.ca/~kbstorey/ _________________________________________________________________ Find a local pizza place, movie theater, and more .then map the best route! http://maps.live.com/?icid=hmtag1&FORM=MGAC01 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=29217