X-Message-Number: 15361 Date: Wed, 17 Jan 2001 04:31:11 -0500 From: Paul Antonik Wakfer <> Subject: Reply to Ettinger Part 3 - # 15249 & 15279 Once again, lack of comment about any particular Ettinger statement does not signify agreement that it is correct or even pertinent. >From: >Date: Wed, 3 Jan 2001 23:18:07 EST >Subject: Vitrification and Evaluation [snip] >4. Toxicity of the solution is said to be relatively low. This is based on >experiments with slices from the hippocampus of the rat brain, using a >similar but LESS concentrated solution, which resulted in 53% viability >relative to untreated controls. This is believed to mean that about half the >cells survived, as determined by a single chemical/physiological criterion, >the potassium/sodium ratio. It also means, of course, that almost half of >them died, or at least were not restored to function. Once again, this is misleading and/or incorrect. 1. The sodium/potassium ratio test is not a "single chemical/physiological criterion", but requires large portion of the cellular machinery to be active and highly functional for the ratio to be maintained. The same machinery required to effect this ratio will also cause most of the rest of the cellular functions to also be intact and operational. This is the reason why the sodium/potassium ratio was chosen and is such an excellent test of the functional viability of the cells in question. 2. As stated before, the test is a global one, not an individual cellular one. 53% does not mean that almost half the cells are dead or have ceased to function (actually the same thing for cells). Other tests such as microhistology have shown elsewhere that under such conditions very few cells are disintegrated. 3. Finally, as has been shown for rabbit kidneys, starting out with only about 70% viability as tested by this means, cells can self-recover to full functionality. ------------------------------------------------------------------ >From: >Date: Sun, 7 Jan 2001 12:05:40 EST >Subject: vitrification # 5 > [snip] >What would be new in the Hallelujah sense is confirmed vitrification of >mammalian brains, examined after rewarming from long term storage temperature >and showing minimal damage from at least three standpoints--histology >(microanatomy), physiology (chemical functions), and electrophysiology >(neural net function). Here Ettinger once again shows a complete lack of understanding of (or a willful disregard for) the meaning of vitrification. I repeat once more that vitrification means nothing more nor less than the lack of crystallization upon cooling. Neither physiology nor electrophysiology have any import on the determination of whether vitrification has occurred or not. There are many kinds of damage besides that caused by crystallization which can prevent return of full cellular and intercellular brain functionality. Some of these are cooling/shear damage (think of the bending and displacement of a cooling bimetal strip) and chemical damage. From the above statement, Ettinger is clearly confusing vitrification with fully perfected suspended animation. This confusion in the minds of many well-meaning but unskilled cryonicists was why I made my original post - to somewhat tone down the unrealistic notions of the worth of vitrification. It is a leap forward, by all means, but it does not mean that we can now rest easy. It does not means that we are now all "saved" and can stop worrying and working hard to perfect suspended animation. -- Paul -- The Institute for Neural Cryobiology - http://neurocryo.org A California charitable corporation funding research to perfect cryopreservation of central nervous system tissue for neuroscience research & medical repair of the brain. Voice-mail: 416-968-6291 Fax: 559-663-5511 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=15361