118 replies to this topic

[ocsrazor]

A quick correction Dis,

Vitrification is much more likely to allow a wake-up process with something close to current medical technology. The chemicals used to vitrify cause a great deal less damage to biological tissue than what has been used previously, and can be washed out of the tissue. There are experiments underway which are showing that biological tissues are still functional after vitrification and washout (whole animal studies are a little further off). Nanotechnology is only necessary if there is significant damage to cells, as has been caused previously with hard freeze techniques. So far, it looks like vitrification is much less destructive and it may make near term reversal of suspension a possibility.

Peter

[Discarnate]

Thanks for the correction, Peter. . . I hadn't realized they'd gotten that far.

Which tissues have they tested so far? Or is there a good link to the study/studies in question?

-Discarnate

[ocsrazor]

Greg Fahy, Brian Wowk and the team at 21st Century Medicine are carrying out the research. I know that kidney and brain are the two tissues they are focusing on. These two tissues have the most complex and easily disrupted structures in mammalian systems, and so make good targets for verification of the process. I just recently offered to consult with their neurophysiologist for verifying that brain slices are still functional as far as signalling by using multielectrode arrays. So far they have been able to show that there is very little structural damage in brain slices (by electron microscopy) They are close to publication on this data. Pubmed (pubmed.com) "Fahy, GM" for the paper trail on the research. The most recent pub on the kidney function data is:

Arnaud FG, Khirabadi BS, Fahy GM.

Transpl Int. 2002 Jun;15(6):278-89. .

Normothermic blood perfusion of isolated rabbit kidneys. III. In vitro physiology of kidneys after perfusion with Euro-Collins solution or 7.5 M cryoprotectant (VS4).

[Lazarus Long]

I have been planning a surprise for display purposes but I think I should at least give some of you here fair warning, especially those coming to the meeting. Peter, I believe you in particular will enjoy the now not such a surprise.

My father and I have a patent on his research now dating back over ten years on the patent and more than four decades on the first samples of human tissue we have been preserving using what you are calling cryprotectants but in essence can eliminate the need for cryo all together. I will have some recent samples and some decades old samples that have their DNA intact as well as having only a been kept at room temperature all this time, and not under sterile conditions.

No decay, no percieved aging or deterioration and the only perceived problem is a certain amount of hydrophilic activity during the summer high relative humidity periods, but we were able to control this with just a dehumidifier even when ambient temperature was relatively high.

I prefer to discuss the details in person but if you research my father's name, Dr. Bernard Sills, you will find his articles dating back to the 1950's & 1960's on the techniques he developed and the applications for using PEG (polyethylene glycol).

When we get together I will explain in greater detail but during the mid 1990's we did an entire cadaver for the UNAM Medical School Museum. The body was preserved intact and microtomed like an Escher painting. It is still used for teaching purposes there in Mexico, along with numerous displays of our work.

We used both the circulatory system and lymphatic when possible to pump the PEG (we were working on tissue preservation for research purposes only) and operated with low pressure pumps and total immersion to replace almost all of the water, but basically what we didn't replace we were able to modify into solution with the PEG down to the level of the cell nuclei.

Essentially, we "fixed" all the cells in the body simultaneously. We were even able to modify bone tissue. I will gladly discuss this topic in great detail but not as the formal presentation. I am looking forward to a "lively" discussion on reversing the death process when we talk, but as far as I am concerned I still think that until we can better understand what is going on with the brain and its relationship to the mind; dead is dead. And unless we create a suspended state prior to death I suspect all we are saving is the DNA and maybe even a body for a reboot, but identity function will be lost. Please, prove me wrong.

So expect some interesting, very special effects for curious minds to examine. I wasn't joking when I said that in a way I am trained in a modern variation of the ancient art of mummification.

[myworldline]

I voted it will not work at the moment, it cannot possibly work, spend your money on a nice car or around the world cruise instead. Nanotechnology is not if close and the freezing techniques that can resuscitate a cadaver back to life. They use cannot even reliably freeze a kidney at those temperatures and make it viable again.

IMO if nontechnology does ever advance to the level of being able to resuscitate a frozen cadaver (which I doubt), scientists in the future time will view the current efforts of Alcor as being so extremely archaic and amateurish, they would be no better than the ancient Egyptians methods of preserving their cadavers in the vein hope of resurrection. These scientists will not even bother trying to resuscitate the Alcor cadavers, preferring the far more advanced freezing techniques they used instead, and will be using and simply dismissing Alcor as getting it completely wrong. They will probably just laugh lol and treat Alcor as a real joke.

Edited by myworldline, 06 July 2003 - 11:23 PM.

[ocsrazor]

myworldonline

I would like to know what your technical background is that you think you can evaluate the effectiveness of the techniques being used for biological suspension. You obviously didn't read the references I posted above, vitrifying kidneys and bringing them back to temperature with little or no loss of function is currently being carried out in the lab.

Of course the technology is going to advance, but if it is at all possible, scientists will try and rebuild those that have already been stored with more primitive techniques. They will likely be seen as pioneers, doing they best they could with the available technology.

Best,
Peter

[myworldline]

myworldonline

I would like to know what your technical background is that you think you can evaluate the effectiveness of the techniques being used for biological suspension. You obviously didn't read the references I posted above, vitrifying kidneys and bringing them back to temperature with little or no loss of function is currently being carried out in the lab.

Of course the technology is going to advance, but if it is at all possible, scientists will try and rebuild those that have already been stored with more primitive techniques.  They will likely be seen as pioneers, doing they best they could with the available technology.

Best,
Peter

Peter

I sure those future scientists will be using cryoprotentants you and I have never heard of and they would not bother with our hillbilly pioneers, they will eventually be thawed out and disposed of to make room.

Through genetic engineering you may even have to change the human genome to inocorperate genetic information from another freeze tolerant species of animal like the gray tree frog.

You may have to be born with those genes first.

Edited by myworldline, 07 July 2003 - 03:12 PM.

[Utnapishtim]

myworld:
I disagree with you quite fundamentally on this. You underestimate human curiousity for one.

If it were possible to wake up the mummies currently housed in the british museum don't you think we would do it?

Thawing out the current alcor patients couldn't happen unless Alcor had a total financial meltdown (no pun intended) Given thearrangments that are currently in place I think that fairly unlikely.

[DJS]

I sure those future scientists will be using cryoprotentants you and I have never heard of and they would not bother with our hillbilly pioneers, they will eventually be thawed out and disposed of to make room.

myworldline,

I believe that the jury is still out on the utility of cryonics. But I'll tell you this, I would much rather take my chances being frozen than to be placed in the ground with the worms [":)] .

Futher, your insights lack business/legal perspective. Don't you think that the individuals frozen at Alcor have contracts with Alcor to guarantee their preservations?? Second, even if they did not, do you really think Alcor would thaw them out and chuck them in the dumpster?? Yeah, that makes real business sense [8)] . Part of Alcor's business imperative is to promote trust from its clients. Who would ever elect to be cryogenically frozen by Alcor if it came out that the older bodies were being dumped?

And finally, why would Alcor dumped bodies to make room. They will just make more room when demand dictates it. You've never taken a business class, have you?

The only way that the bodies may be disposed of is, if in the distant future it is determined that the brain operates using quantum effects (which I doubt). Then it would be appropriate to give the bodies a proper burial since the essence of the individuals involved would be lost forever.

Kissinger

[myworldline]

myworld:
I disagree with you quite fundamentally on this. You underestimate human curiousity for one.

If it were possible to wake up the mummies currently housed in the british museum don't you think we would do it?

Thawing out the current alcor patients couldn't happen unless Alcor had a total financial meltdown (no pun intended) Given thearrangments that are currently in place I think that fairly unlikely.

Waking up the mummies in museums, that not even sound like science fiction to me, it's just pure fantasy.
There are plenty of other companies much bigger that Alcor that had a total financial meltdowns, Enron is a little bigger.
Who will pay for the reviving process at the other end. Do you seriously believe Alcor will do that in the goodness of their hearts? That's a thought let them try and revive an entire pig's heart and see how far they get.

[DJS]

DUDE [huh] [huh] ,

You have no idea what you are talking about.

[ocsrazor]

myworldonline,

The statements you are making are just downright silly, please go do some research before you embarass yourself further. I'm not saying this to be mean, but you are showing that you have a complete lack of knowledge on this subject. Rather than making knee jerk statements with no basis in fact, why don't you try asking some questions of the people on this board. There is a very serious amount of intelligence and experience here.

As I said before, of course the technology will advance, but we are already nearing perfect preservation. This technology will not need to advance a great deal further. I estimate 10 years to a fully developed vitrification process, faster if some serious money gets thrown at the problem.

Genetic engineering will not be necessary to achieve suspension. The "antifreeze" proteins used by frogs are inferior to the synthetic cryoprotectants currently being used by researchers. The problem is one of size of humans - you need to rapidly cool organs to get good cryopreservation and the large size of humans is something that is causing difficulty.

As Kissinger pointed why would you ever dump suspended people? Storage space is prepaid for by the person being suspended through a financial trust. Barring complete financial collapse of our society the people already stored aren't in much danger. Alcor has made arrangements such that even if Alcor itself were to go bankrupt and could no longer perform suspensions, the maintenance of those already stored will be taken care of.

You obviously misunderstood the comment by Utnapishtim about the mummies, he said if it were possible, he did not state it as a realistic possiblity. I agree with him that if it were possible we would certainly try and revive someone from the past.

The work on heart preservation is already underway, and this does not appear to be as much problem as the kidney. (Kidneys have a much more complicated structure) The most difficult organ to preserve will be the brain of course, but there has been significant progress this year which will be published shortly. Expect to start seeing banking of organs for transplant through cryogenic preservation within the next 5 years.

Best,
Peter

[ocsrazor]

Hi Gang,

For those of you here in Atlanta with some interest in cryonics, there will be a talk tommorrow morning entitled "Cryopreservation: Temporary Suspension of Life" by Dr. Jens Karlsson. He is a professor here at Georgia Tech, and is one of the leading experts in the world on cryopreservation. The talk will be held at 9AM in room 1128 (main seminar hall) of the Institute for Bioengineering and Biosciences on the GT campus. Feel free to drop me a message tonight if anyone is interested in attending.

For further information - this is Karlsson's website http://www.me.gatech...lsson_Jens.html

Best,
Peter

[myworldline]

myworldonline,


The work on heart preservation is already underway, and this does not appear to be as much problem as the kidney. (Kidneys have a much more complicated structure) The most difficult organ to preserve will be the brain of course, but there has been significant progress this year which will be published shortly.  Expect to start seeing banking of organs for transplant through cryogenic preservation within the next 5 years.

Best,
Peter

Peter

I agree that freezing of the heart is a lot easier, so why is Alcor not ready for this simple experiment:
Get your healthy pig or some other animal of comparable size to a human and remove its heart and freeze for a week to the best of Alcor's technology and keep the pig on artifical back up for a week then thaw that frozen heart and transplant it back into the pig. Remove artifical back up and see how far you get.

The pigs heart is about the same size and mass as a human's that is what I insist on an animal of comparable size. But a Gorilla or large baboon will do.

Has this already been done? I would like to know

Edited by myworldline, 08 July 2003 - 02:35 AM.

[ocsrazor]

myworldonline,

Alcor does no research of its own, it is simply a service provider. They use the best available technology from a combination of private and public labs. The world's expert on heart cryopreservation is probably Dr. Tinchung Wang at the University of Rochester. He has been able to freeze rat hearts, and is working on scaling up to larger hearts using vitrification. As I metioned, size is a critical issue that is being worked on. I expect that within the next 2-5 years this problem will be solved.

Peter

[myworldline]

Peter

This is about the best they can do

Dr. Roger G. Gosden of McGill University in Montreal and colleagues report the successful transplantation of rat ovaries that were stored in liquid nitrogen.
Transplanting frozen organs is still in its infancy, but the research demonstrates that the approach is feasible, Gosden told Reuters Health.

"Attempts over many years with a variety of other organs failed to restore function, mainly because of damage to the blood vessels," Gosden said. This damage results from the chemicals used in the freezing process, he explained.

Blood vessels will be hard, but that is nothing compared the brain dendrytes and synanptic clefts. The freezing process to those would be nothing short of catastrophic

MWL

Edited by myworldline, 08 July 2003 - 02:58 AM.

[DJS]

Did everyone go to that web site that is fighting to have Ted Williams unfrozen? Does anyone think they have any case whatsoever? The law suit states that Alcor is making fraudulent claims. I think these people haven't done their homework. The agreement is that the individual will be frozen indefinitely -- that's it right? Alcor would never make a guarantee of a future resuscitation, that would be stupid.

The interesting part about this whole affair is that it shows that there are still people out there who don't like change and don't like their "traditional values" being challenged. Alcor is still pretty small in the scheme of things. Imagine the reaction there would be if 10% of the American public started to freeze themselves?

The arguments that this anti-cryonics group makes are really weak. One of their claims is that because Ted Williams is frozen it violates his "human dignity". I wrote them an email asking them to define human dignity. Is human dignity being burnt to ashes and kept in your daughter's living room? Or how about being buried with the worms, maggots, and other earth creatures? Is that human dignity for you?? It is obvious that, for this group, human dignity is code for religious sanctity. They don't like people giving the middle finger to their god.

[ocsrazor]

MWL

I'm currently consulting on a project to do functional analysis of brain cryopreservation (I'm a neuroscientist). It appears that perfect structural preservation has already been achieved down to submicron resolution - there will be a publication on this soon. This is below synapse or dendrite resolution. Functional analysis is just beginning, probably will take 6 months or more. As the quote you mentioned states, damage was due to the chemicals used, which was previously glycerol based substances. In the newer vitrification techniques the chemicals are not nearly as toxic.

Peter

[myworldline]

MWL

I'm currently consulting on a project to do functional analysis of brain cryopreservation (I'm a neuroscientist).  It appears that perfect structural preservation has already been achieved down to submicron resolution - there will be a publication on this soon.  This is below synapse or dendrite resolution.  Functional analysis is just beginning, probably will take 6 months or more.  As the quote you mentioned states, damage was due to the chemicals used, which was previously glycerol based substances.  In the newer vitrification techniques the chemicals are not nearly as toxic.

Peter

Peter

Well being a neuroscientist your are, are you prepared for this little experiment:
If you took ten brain tissue samples from frozen cadavers from the 1970s and ten from the late 1990s and you did a double blind test on which would be the most viable. Are you confident you will score 10 out of 10 and choose the samples out of all the cadavers of the late 1990s?

Also as you know the Badhdad telephone network was totally destroyed so when the new telephone infrastructure is brought up and running after this war (if it ever finishes), it may work fine, but how would you know if it is identical to how it was before the war?
Same as the brain, if some bio-technicians reconnected all your synapses, then it probably may not even be you. In fact they may even inadvertantly revive the mind of Adolph Hitler for all they know.

MWL

Edited by myworldline, 08 July 2003 - 03:55 AM.

[ocsrazor]

It doesn't depend on the time it was done, but on the technique. If I was shown electron micrographs of brains frozen or vitrified with a variety of different processes (chemicals, concentrations, times, etc.) I'm pretty confident that I could identify which technique had been used if I was shown enough samples from each. If this is what you are getting at - vitrified (the most recent technique) tissue looks significantly different than frozen tissue.

The Baghdad metaphor is pretty poor, because the information loss is tremendous less significant in a cryopreserved brain than in a destroyed telephone network. You are not doing a total reconstruction. With vitrification there appears to be almost no structural loss, there is no reconnection necessary. The difficulty is getting the chemicals in and bringing the temperature down fast enough to get as little loss as possible.

The connections and processes that are "you" change every second of your life. There is no doubt cryo is going to be a traumatic event, in majority of cases the patient will have "died". But people who have near death experiences do not usually go insane. The vast majority of the physical structure of the brain and its physiology will be preserved, so I would project that the post-cryo patient would have continuity of personality with the pre-cryo patient. You are not going to create a psychopath from a normal personality without very significant levels of damage to the brain.

Peter

[myworldline]

It doesn't depend on the time it was done, but on the technique.  If I was shown electron micrographs of brains frozen or vitrified with a variety of different processes (chemicals, concentrations, times, etc.) I'm pretty confident that I could identify which technique had been used if I was shown enough samples from each.  If this is what you are getting at - vitrified (the most recent technique) tissue looks significantly different than frozen tissue.

Peter

So if the Alcor of 2023 where to compare the samples of 2003 they will find them to be significantly different too. It does sound to me like a chain of silly experiments. Do you then think we ought discontinue research into reviving 1970s cadavers into something more fruitful?

The Baghdad metaphor is pretty poor, because the information loss is tremendous less significant in a cryopreserved brain than in a destroyed telephone network. You are not doing a total reconstruction.  With vitrification there appears to be almost no structural loss, there is no reconnection necessary.  The difficulty is getting the chemicals in and bringing the temperature down fast enough to get as little loss as possible. 

Yes it is relevant because our brains software is all we are. If you completely lost all the files and programs on your computer then how can you retrieve it if you never thought to back them up anywhere? You may be able to reformat your computer with new files and programs but it wil not be the same. In spite of the fact it has the same physical material

The connections and processes that are "you" change every second of your life.  There is no doubt cryo is going to be a traumatic event, in majority of cases the patient will have "died".  But people who have near death experiences do not usually go insane.  The vast majority of the physical structure of the brain and its physiology will be preserved, so I would project that the post-cryo patient would have continuity of personality with the pre-cryo patient. You are not going to create a psychopath from a normal personality without very significant levels of damage to the brain.

Peter

NDEs would be like a few short circuits compared to cryo-injury which is like an magnitude 8 earthquake under the New York underground telephone exchange smashing every fiber optic and other cable to smithereens

MWL

[ocsrazor]

MWL,

The earliest frozen patients are definitely going to be the hardest to revive, nobody has ever said anything different. It may not be possible to revive those frozen with straight liquid nitrogen. As any technology approaches maturity its form changes exponentially less. As cryopreservation approaches success the technique will change less and less. Vitrified tissue looks significantly different than previous techniques because the tissue is almost perfectly preserved. Cryopreservation approaching success is silly? I think you are uncomfortable with the fact that it will be successful in the very near future.

The brains are software comment is another poor metaphor - you don't understand how memory storage works in biological systems, it is not like a digital computer. There are 4 distinct memory systems in the brain, 3 of which are structurally stored, not dynamically. The 4th is short term memory (<1 hour), which will be lost during cryopreservation because it is dynamic. The physical structure is the memory for the other 3. There is no reformatting necessary, because memory is an inherent part of the system - if the system works, the memory is still there.

NDE's are likely very similar to what would be experienced by a cryo patient. Once again you do not understand the technology. With the more recent techniques there is very little structural damage. You are likely not going to need to rebuild anything if the current line of research is successful, just flush out the cryoprotectants and deal with whatever the original cuase of death was.

I'm no longer going to reply to blatantly false comments, I've tried to be helpful, but I can't tolerate willful ignorance. If you want to ask rational questions, I will be available, but go try and educate yourself before making more content free statements. I'm too busy to suffer fools gladly.

Peter

[myworldline]

MWL,

The brains are software comment is another poor metaphor - you don't understand how memory storage works in biological systems, it is not like a digital computer. There are 4 distinct memory systems in the brain, 3 of which are structurally stored, not dynamically. The 4th is short term memory (<1 hour), which will be lost during cryopreservation because it is dynamic. The physical structure is the memory for the other 3. There is no reformatting necessary, because memory is an inherent part of the system - if the system works, the memory is still there.

Peter


A house is structural, but if you reduce it to a pile of bricks there are billions of possible architectural configurations for many house designs in that pile of bricks. As you know being a neuroscientist if the brain is reduced to a pile of proteins there would be trillions upon trillions of possible architectural configurations for many brain designs and it would be extremely unlikely for a nano-technician at the other end to fluke on the right one.

NDE's are likely very similar to what would be experienced by a cryo patient.  Once again you do not understand the technology.  With the more recent techniques there is very little structural damage.  You are likely not going to need to rebuild anything if the current line of research is successful, just flush out the cryoprotectants and deal with whatever the original cuase of death was. 

I'm no longer going to reply to blatantly false comments, I've tried to be helpful, but I can't tolerate willful ignorance. If you want to ask rational questions, I will be available, but go try and educate yourself before making more content free statements. I'm too busy to suffer fools gladly.


Peter

What kind of a neuroscientist are you?

Cryo-patients having NDE's !(sic) You must be joking lol Cryo-cadavers are what you call them, and that is the way they will stay. Sad to break the cold hard news to you (pardon the pun).
Have you ever revived a "cryo-patient" and asked them what kind of NDE they had?
How can you make such outragous speculations?
Surely no one else believes that Cryo-cadavers have NDE's.

MWL

Edited by myworldline, 08 July 2003 - 10:59 AM.

[Discarnate]

MWL -

"What kind of neuroscientist are you?" - Well, the question applies in the reverse as well - what kind of work have YOU done in the field?

OcsRazor *is* a researcher in the field of neural science. He works with stuff I am unable to rationally comment on beyond a common-sense point. I've seen some of the papers he's worked on, some of the reports and such.

Are you?

If not, why'n hell do you doubt him? Can you point to evidence - not suspicions, not feelings, but EVIDENCE - that he's wrong?

Lemme quote you again, MWL - "A house is structural, but if you reduce it to a pile of bricks there are billions of possible architectural configurations for many house designs in that pile of bricks. As you know being a neuroscientist if the brain is reduced to a pile of proteins there would be trillions upon trillions of possible architectural configurations for many brain designs and it would be extremely unlikely for a nano-technician at the other end to fluke on the right one. "

You are actually underestimating the complexity of the situation by many many orders of magnitude - *IF* everything is reduced to "a pile of proteins". (Little thought experiment. Let's say a neuron is, oh, 1,000 unique proteins with only one copy each. (way low). Let's also say that there's only 40,000 neurons in a brain. (also low). This means if everything is protein stew, no order, there would be 40,000,000 P 1000 (nPr - stats for permutations) versions to worry about - that's 40,000,000 * 39,999,999 * 39,999,998 * .... * 39,999,001 - one helluva big number. Trillions and trillions and trillions is about 10^27th. The real number is in excess of 10^7000 -one HELL of a big number.)

However, this is not the case. Even the nitrogen-preserved people maintain large degrees of structure in cryogenic suspension. Also, as Peter/OcsRazor mentioned in an earlier post, the newer procedures have gotten to the stage where "perfect structural preservation has already been achieved down to submicron resolution", to use his words. There goes your broken house analogy right out the window, sorry.

I have to agree w/ Peter - please go read up on the subject more and stop throwing flame-bait around. At the very least, it's unpleasant, at the worst it's deliberately wrong.

-John/Discarnate

Edited by Discarnate, 08 July 2003 - 12:11 PM.

[myworldline]

Well Discarnate

No I am not a neuroscientist and never profess to be, I am just flabbergasted that he happens to be one. One that comes up with the preposterous assumption that frozen cadavers are capable of NDEs. Has he got any evidence for that?

However, this is not the case. Even the nitrogen-preserved people maintain large degrees of structure in cryogenic suspension. Also, as Peter/OcsRazor mentioned in an earlier post, the newer procedures have gotten to the stage where "perfect structural preservation has already been achieved down to submicron resolution", to use his words. There goes your broken house analogy right out the window, sorry.

I have to agree w/ Peter - please go read up on the subject more and stop throwing flame-bait around. At the very least, it's unpleasant, at the worst it's deliberately wrong.

-John/Discarnate

How is the whole brain preserved is it through slices like
vitrification of slices of the hippocampus
or is it frozen in one complete mass.
How would you like your's to be preserved. Sliced or Complete?
If complete:
To see the flaw in this system, thaw out a can of frozen strawberries. During freezing, the water within each cell expands, crystallizes, and ruptures the cell membranes. When defrosted, all the intracellular goo oozes out, turning your strawberries into runny mush. This is your brain on cryonics

And I have been doing my homework Here are a few links you may enjoy
Nano Nonsense and Cryonics

Quack Watch

Edited by myworldline, 08 July 2003 - 11:32 PM.

[ocsrazor]

MWL,

As to my background: BS microbiology, MS cell and molecular biology with a focus in neural physiology and biochemistry. Expertise in neural development and systems neuroscience. Four years as VP and biotechnology analyst of an investment company for aging research startups and simultaneously VP of a nonprofit foundation for stimulation of aging biotechnology. Currently working on my PhD in the neuroengineering lab at Georgia Tech imaging neurons, building neural interfaces, and modeling neuronal networks. I'm pretty sure I know what I'm talking about.

I'm going to make one more attempt to explain things in as simple terms as possible for you. You do not reduce a brain to proteins even with the harshest of cryogenic techniques - at the very worst cells are pierced by ice crystals and their contents leaks, but most of the structure is still there. This is difficult to recover from biologically, but it might be theoretically possbile to rebuild the structures with mature nanotechnology. For the third time - This type of damage DOES NOT OCCUR using the more current cryogenic techniques.

There are two sources of damage to biological tissue due to low temperature exposure. The one you are fixated on is mechanical damage, which can be caused by formation of ice crystals either internally or externally. The second source of damage is salt toxicity which is caused by too much water being removed too quickly from cells during suspension. Both of these types of damage have already been overcome in cell suspension, simple tissues, and small organ systems.

This has been achieved by raising the solute concentration just enough so that the water in the tissue "glasses" without going through a crystalization phase. No crystals, no mechanical damage. In the following diagram areas 2 and 3 represent the region in which crystal formation occurs, by cooling without passing through this region you can go straight from a liquid (area 1) to a glass (area 4) where all molecular motion is restricted.



The difficulty currently being worked on is scaling up to larger tissues, the correct rates of cooling and the correct solute concentrations are difficult to maintain over large tissues. These do not appear to be huge difficulties to overcome though, they will just require diligent experimentation.

My comment about NDE's was a PROJECTION based on what I know of the effect oxygen and glucose deprivation has on the brain during a traumatic event. The types of memory loss are likely to be very similar in the two events, because the physiological trauma produced is going to be very similar. OF COURSE no one can revive a cryonics patient yet, that is the whole point of suspending someone, the technology is not YET available. This is not outrageous speculation, but is based in the rapidly increasing success rate of researchers in the field and the types of post-cryo tissue trauma being observed in the lab.

The comparison to frozen strawberries by Michael Shermer would only be true if you did a straight freeze/thaw with no cryoprotectants. This type of freeze was done only in a few cases in the 60 and 70's. Even so those people could still be recovered by never thawing them at all and using mature nanotech to rebuild the damaged tissue - this is still highly speculative though. Once again, you do not see this type of damage with the techniques currently being used.

You misunderstood the significance of the slice article by Ben Best. Rat brain slices are used in the lab only for evaluation purposes, because they are easy to work with under the microscope and in electrophysiology equipment. The link you provided is to a description of a research procedure, not one that would be used clinically on humans. No one is proposing slicing up brains to preserve them.

Neither the journalists of Scientific American, nor Dr. Barrett are reliable sources of information on this subject - both tend to be knee-jerk reactionaries who do not fully research their subjects. You have to go to the medical research journals to get an accurate view - try the national library of medicine at www.pubmed.com

Peter

Edited by ocsrazor, 08 July 2003 - 11:02 PM.

[myworldline]

Peter

Why does he not try slicing the rat brain after it has be frozen treated with cryoprotectants and thawed?
What would be the difference if it was frozen on one solid mass?

Do more research on how large volumes of matter undergos phase transitions.

Then you are left with one more fundamental physical problem, entropy. Frozen matter my look rather static to us by it is still technically warm and as a consequence it is deterorating and become more disorganized all the time.

MWL

[DJS]

Then you are left with one more fundamental physical problem, entropy. Frozen matter my look rather static to us by it is still technically warm and as a consequence it is deterorating and become more disorganized all the time.

I am not an expert, but you should know that we are not just talking about freezing here. We are talking about freezing at almost absolute zero. Movement stops at this temperature.

Are you intentionally playing the antagonist to get better feedback from the participants of this forum?

Edited by Kissinger, 08 July 2003 - 11:40 PM.

[myworldline]

I am not an expert, but you should know that we are not just talking about freezing here.  We are talking about freezing at almost absolute zero.  Movement stops at this temperature.

Are you intentionally playing the antagonist to get better feedback from the participants of this forum?

Thanks for that, anyone could of told those cryonuts that. But obviously I just have to call it a truce and agree to disagree. I have been on similar stouces with religious fundies on other forums, it just gets you nowhere.

Edited by myworldline, 08 July 2003 - 11:57 PM.

[DJS]

But you have yet to tell us where you stand MWL....