X-Message-Number: 15301 From: Date: Tue, 9 Jan 2001 11:05:27 EST Subject: Platt's toxicity Platt (#15298) is wrong again, and the anonymous scientist he mentions was doubtless too hasty to be accurate, in this question of toxicity. Platt writes: >In response to Ettinger's suggestion that the vitrification solution now >being used by Alcor is probably more toxic than the simple glycerol >cryoprotectant used at CI,... I did NOT say that Alcor's solution is more toxic than glycerol. Platt, with his usual honesty and brilliance, is refuting a statement I did not make. I said that Alcor's solution is probably more toxic than the solution tested by INC et al which showed 53% viability. See Fred Chamberlain's article and my recent posts for verification. The anonymous scientist, whose name we all know, was doubtless too busy to pay careful attention, but Platt was not too busy, so either he is having mental lapses or else he is again simply indifferent to the facts. The second part of Platt's criticism concerns the meaning of "53% viability." As far as I know, none of the public material goes into detail on this. Does it mean that about half the cells survived, as I suggested, or that all of the cells, on average, functioned at 53% of normal? If it means the latter, then I went too far--but by how much is still not clear. If measurment of total potassium/sodium ratio for a tissue sample containing many cells shows 53% of normal, and since we know that there is variability among cells, how can we be sure of the variance in viability (as a culture might reveal it)? How can we know how many were 99% impaired and how many only 1% impaired? I'm sure Platt doesn't know, and I doubt that anyone does. Platt suggests that a cell half dead can recover. Right--this was one of my original arguments for optimism about cryonics; if even a few cells show even some signs of life, then it is not unreasonable to expect that future technology might be able to restore all of them, or most of them, or/and replace those actually destroyed (if "destroyed" has any clear meaning in this context). But this line of reasoning tends to support MY overall viewpoint, not Platt's. Finally, since happily Platt after all has time to set things right on Cryonet, l ask him yet again--the 5th time?--to tell us why he does not excoriate Paul Wakfer for criticizing Alcor's overblown claims somewhat as I did. I quote Wakfer again: >First, being able to vitrify by cooling does not necessarily mean that >specimens can remain ice-free or otherwise damage free during rewarming. >Second, we have always been able to vitrify, but this was not done because >the toxicities involved (even some disintegration of cell membranes) were >clearly not tolerable to restoring life. The current vitrification procedure >does still not leave the tissue viable, but the toxicity is low enough that a >decision has been made by someone (perhaps partly for promotional reasons) >that toxicity damage is "better" than ice damage. Since we currently have no >method of restoring from either kind of damage, this decision is at best a >"guesstimate" rather than a decision based on scientific research. To take an >extreme example, long-term preservation in embalming fluid has always been >possible (and without ice damage!), but no one ever proposed it because no >one ever thought that life could ever be restored from that state, or even >that the mind was fully captured and preserved. Thus, until we actually >finish the necessary research to restore to life a person who is preserved in >a manner which allows no deterioration over a long term, I think that it is >premature to say what kind of technology will or will not be necessary for >that restoration. Robert Ettinger Cryonics Institute Immortalist Society http://www.cryonics.org Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=15301