From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med,sci.life-extension Subject: Re: Freeze-dried mouse sperm fertilizes eggs Date: 30 Jun 1998 08:42:11 GMT In <6n9o3d$tg7$1@basement.replay.com> nobody@REPLAY.COM (Anonymous) writes: >http://dailynews.yahoo.com/headlines/health/story.html?s=z/reuters/980 >29/health/stories/sperm10_1.html > >Monday June 29 6:39 PM EDT > >Freeze-dried mouse sperm fertilizes eggs > >NEW YORK, Jun 29 (Reuters) -- Though technically dead, reconstituted >freeze-dried mouse sperm can still be used to fertilize eggs -- and the >process results in normal offspring, according to a groundbreaking study >in the July issue of Nature Biotechnology. > >The study is the first confirmed and replicated research showing that >freeze-dried sperm can produce normal offspring, write the authors, Dr. >Teruhiko Wakayama of the University of Hawaii School of Medicine in >Honolulu, and Dr. Ryuzo Yanagimachi of the University of Tokyo in Japan. > >[snipped] Comment: Big deal. We've been able to freeze-dry skin and corneal cells for years and show that they can be rehydrated and live. There's even a little crustacean called the tardigrade (a critter with 10 legs like a mite, and about that size) which can be entirely freeze-dried, and rehydrated years later. Tardigrades from museum moss a century old come back to life when "wattered," if only briefly (that much time apparently does do ultimately fatal damage). In the dehydrated state, tardigrades can even tolerate vacuum and liquid nitrogen or liquid helium temperatures. As can many a frozen or vitrified cell. There is no metabolism at 4 Kelvin. Life is not function, folks, it's structure. Information. You're not dead until your information is gone. All that can be said instead is that you're out of order-- nonfunctional-- like any other nonworking machine. It will have occured to you that many people are declared legally dead today long before their information is gone. Well, sure. Declaring somebody legally dead is like declaring them legally married. Nothing changes but the *legal* status of the person. Biological status, which doesn't pay much attention to the courts, is another matter. It is at this point that cryonics enters in, with obvious reasoning. Cryonics isn't about freezing people who are Dead-- by which we mean really most sincerely dead. Informationally dead. Rather, cryonics is only about freezing people who are legally dead, which is not the same. Legally dead people for some hours, and perhaps much longer (depending on treatment) are still alive by many standards, and almost certainly by the standards of a very high tech future (if such a future comes). You can culture live neurons out of brains dead 8 hours today, without even any special treatment or even good cooling. There's a lot of life in things we have by definition consigned to other categories. Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med Subject: Re: What is the precise definition of death? Date: 23 Apr 1998 00:12:47 GMT In <353E4065.38460BF9@gw-tech.com> Carey Gregory <cgregory@gw-tech.com> writes: >Steven B. Harris wrote: > >> Can't even use that. There are lots of children who were once >> embryos in liquid nitrogen. No metabolism. But they, as organisms, >> clearly were not dead. > >True, but once the metabolism is switched on, switching it off again is a >pretty good definition of death. These embryos were once alive, dividing. Switched on. In LN2 they're stitched off. Later to switched on. can do the same with dozens of kinds of cells. Only thing which prevents with organs is thermal stress (cracking) if you go too cold after vitrification, and the toxicity of the vitrifying chemicals themselves (which are very close to being too toxic but not QUITE, if you cool really fast, and warm really fast, to get you through the metastable ice-forming temp zone. Expect this by in the next few years. >Is there a technology of the future that could return inert cells to a >functional state? Perhaps, but until then I think cessation of cellular >metabolism is the best definition of death for the question as asked. As >a practical measurement, ambient CO2 levels in expired air works >nicely. Not in resusciated animals. All it means is that perfusion of lungs has stopped. That's a strictly mechanical problem due to a lack of a mechanical thumber which works by active compression decompression. Having lungs full of flurocarbon may work also. Finally remember that cells quite producing CO2 when they do anaerobic. If you cardiac arrest for 16.5 min, you don't have CO2 coming out of the lungs-- nothing to transport it. Start it all back up with a hear lung machine, and it works fine. I know, I've seen it. >> Life is not metabolism, it is structure. Information. >Interesting perspective.... Cryonics perpective. Perspective of the future. Read Jim Halperin's bood The First Immortal for more. And for a colorful history of cryonics and immortality theory, it's hard to beat _The Great Mambo Chicken" by Ed Regis (_Who Got Einstein's Office_, the story of the PIAS, etc)_ From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med,sci.life-extension Subject: Re: Freeze-dried mouse sperm fertilizes eggs Date: 1 Jul 1998 03:12:16 GMT In <6nan1d$iib$1@ostrich.cybercomm.net> "Jennifer Petersen" <jennifer@jenniferpetersen.com> writes: > >A "legally" dead person can often be kept "alive" almost >indefinately. Their cells will keep functioning. But those >neurons they cultured have, as you put it, "lost their >information", especially if it hasn't been cooled for those 8 >hours. We don't know that, because we don't know for sure how long term memory is encoded. If, as seems likely, it's encoded as additional proteins manufactured to strengthen responses at certain synaptic connections, I can't think of any good reason why such alterred connections shouldn't survive physically in space for as long (or longer!) than the neuron(s) they are part of. Life, if defined as metabolism, is delicate. Structure is tougher. Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med,sci.life-extension Subject: Re: Freeze-dried mouse sperm fertilizes eggs Date: 1 Jul 1998 03:20:22 GMT In <359982E8.9237321E@dnai.com> Michael Sierchio <kudzu@dnai.com> writes: > >Steven B. Harris wrote: > >> Life is not function, folks, it's structure.... > >That's an interesting assertion. I'm not sure I agree -- I'm not sure >I disagree. Some of the functions are interesting, and are integral >to life. May I read your statement as "critters/plants/fungi are DNA's >way of making more DNA?" No. No function is "integral" to live, because at liquid helium temperatures, there is no function. However, life remains. Unless you want to define deep frozen critters as "dead" and then say they were resurrected rather than just revived. But we usually reserve the word "dead" for situations of permanence. If not (as in clinical death, and sudden death syndrome) we generally qualify or modify the word. Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med,sci.life-extension Subject: Re: Freeze-dried mouse sperm fertilizes eggs Date: 2 Jul 1998 10:50:05 GMT In <6ndf04$ba1$1@ostrich.cybercomm.net> "Jennifer Petersen" <jennifer@jenniferpetersen.com> writes: > > Since we concider life to be some amazing, special, almost >mystical thing, the definition of life remains difficult. >Especially since we have a limited sample to examine. Life is >usually defined as some sort of process so where there is no >process, there is no life by that definition. We also define life >as the organism as a whole. So that although the heart of someone >may be beating is someone elses chest, the donor is dead even >though the parts "live" on. The donor's heart is alive. The donor is dead because his brain is dead. > We can expand the definition of life >to include things that where alive, are now, by definition, dead >but could be alive again. That seems to me to be an unnessassary >complication and would make those people in cryonic chambers >still alive even though legally and clinically dead. Yep. That would be scary, wouldn't it? But tell me: is a frozen cell dead, or just in suspended animation? Is a frozen person dead, or just in suspended animation? Are you suggestion that we consider all frozen things "dead", even if we KNOW we can bring them to life again? > Personally, >I see no reason to say someone is resurrected instead of revived. >Funk & Wagnall defines revive as to bring back to *life* OR >conciousness. And "bring back to life" implies life was "lost". I'm not sure that "bring back to life" implies that life was lost, merely that it was absent. Absent can be "lost," but doesn't have to be. > Your assertion that there is life at liquid helium >temperatures would seem to imply that there is something special >about the cells themselves, even without function. That the >structure of a cell defines it as alive. My assertion that there is "life" at liquid helium temperatures is, in one way, merely playing a word game. I'm not at all certain that life is an objective thing. It's partly subjective, like beauty, or the difference between green and blue. Asking if something is "really" alive may be as meaningless as asking it something is "really" complex (versus "simple"). It's kind of like asking how high is "up." I hope there is nobody here who thinks there is a perfectly obvious and completely objective answer to all questions of whether or not a painting or a woman is really beautiful, or a man is really drunk, or an action is really dangerous, or a sound is really loud, or the day is really hot, or a couple is really married. Whether or not a frozen cell or person is really alive probably is the same kind of problem. At the extremes, such things are clear. In the gray zone, it's-- well-- gray. Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med,sci.life-extension Subject: Re: Freeze-dried mouse sperm fertilizes eggs Date: 2 Jul 1998 10:53:10 GMT In <6nd7bv$35f$1@ostrich.cybercomm.net> "Jennifer Petersen" <jennifer@jenniferpetersen.com> writes: > No, we don't know that. Exactly how memories and personality >work is still not fully understood. Much of what we know seems to >be from studying accident victims and people whos brains have >been deprived of oxygen for more than a few minutes. It may be >possible that the brain damage we see with these people is a >matter of restarting the chemical signals at the synapses rather >than actual damage to the neurons. Or perhaps some as yet unknown >process. > Assuming the neurons structure is tough enough, assuming >metabolism can be restarted and assuming structure as a whole is >maintained, then perhaps the "person" could be revived after the >8 hours even without good cooling. We've already seen children >revived without apparent alteration to their personality after 40 >minutes or more in cold weather. Yep. The record for essentially full recovery of a cold water drowned child is over 60 minutes immersion. Set in Utah, where they have a lot of toddlers and a lot of cold mountain stream water. Don't wait for Florida to catch up. Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med.nutrition Subject: Re: altitude effects on longevity? Date: 7 Jul 1998 07:19:08 GMT In <6nqioo$a7v$1@nnrp1.dejanews.com> carmack@bigfoot.com writes: >Just wondering--with all the hype about antioxidants, have there been any >studies done on the effects of altitude or other low-oxygen environments >on longevity? Is it the case that there is less oxygen in the blood in >such environments, or does the body adjust by more efficiently absorbing >oxygen from the atmosphere? And is this even theoretically relevant to >the free-radical theories? Alas, low oxygen environments cause MORE oxygen radicals in most critter that use oxygen, for reasons obscure (at least to me). And when oxygen is cut off entirely, reoxygenation causes a lot of oxygen based radicals. Possibly due to tissue damage and free iron catalyzed Fenton reactions. But there are others, too, like deregulation of xanthine oxidase. Steve Harris, M.D. |
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