X-Message-Number: 15337 Date: Sun, 14 Jan 2001 16:01:01 -0500 From: Paul Antonik Wakfer <> Subject: Reply to Ettinger Part 1 - # 15210 After an absence from CryoNet of nearly 4 months, I have decided to return after been notified of the major distortions and obfuscations which Robert Ettinger is once again perpetrating on a largely ill informed, sometimes innocently and overly optimistic, but often gullible readership by means of his masquerading as a well informed, patient, paternalistic professor. I will confine myself to addressing Ettinger's misinterpretation of the basis and results of current suspended animation research, and particularly of my own previously published remarks, rather than becoming involved in matters involving cryonics organizations. My replies will be posted in installments to prevent overload of Cryonet. After reading Ettinger's very first post in this series on vitrification (#15210), I find that I must begin at the lowest level where he starts right off with fundamental distortions. >From: >Date: Fri, 29 Dec 2000 22:19:44 EST >Subject: Vitrification > >VITRIFICATION FACTS AND PROSPECTS >The word "vitrification" itself is probably fairly familiar to most readers. >It means formation of a glass-like state that is "solid" in the sense that it >does not flow or deform easily, but lacks the clear crystal structure >characteristic of most pure solids. Water solutions that are vitrified have >few or small water (ice) crystals. While this might be acceptable as a correct definition of vitrification, if the size of the ice crystals were well-defined instead of left vague using such words are "few" and "small", together with Ettinger's next paragraph it is quite incorrect right from the outset. Although the glassy state of matter may be defined by its atomic scale structure and thermodynamic properties (physical parameters independent of its origin), for the purposes of application to cryonics, a vitrified (glassy) biological state is fully defined as a configurationally frozen liquid with embedded tissue that failed to crystallize upon cooling. This means that the domains of water or other solute molecules exhibiting repeating patterns (crystal structure) are limited to a few nanometers at most (similar to that for water just above the freezing point). >ADVANTAGES of vitrification over freezing, for human cryopreservation, >include the fact that fewer or smaller ice crystals should result in less >mechanical damage by ice crystals, e.g. fewer tears in cell membranes by ice >crystals formed outside the cells. And if ice crystals tend not to form or >grow, there should be fewer regions where large ice crystals have disrupted >the connections between cells and tissues, or have exerted crushing forces. Again the use of the vague terms "fewer or smaller", "less mechanical damage", "fewer tears", and even the use of the phrase "ice crystals" at all when referring to vitrification, show either a gross misunderstanding or an intentional distortion of the basic definitions with which Ettinger is "setting up" all that follows. In fact, with true vitrification there are *no* ice crystals and *no* mechanical damage which can be reasonably described as "tearing". As the tissue and cryoprotectant solution cool and solidify side by side, the movements of each due to any mechanical distortions of cooling are continuously "stretched" and "molded" together without any lesions except possibly on the molecular scale (similar lesions almost certainly occur in living biological systems and are quickly self-repaired by simple closure/remolding). Whether such true vitrification is being obtained by current Alcor protocols, I am not in a position to say. >(This does not mean that vitrification is the only method of minimizing ice >damage. Ice damage can also sometimes be reduced by removing water, by >reducing the freezing temperature, and by other means to limit the amount of >ice and the size and location of crystals.) While the rest is true, the first line regarding vitrification "minimizing ice damage" is incorrect since true vitrification totally *eliminates* ice damage by totally eliminating all ice formation. >DISADVANTAGES of vitrification include the need (in methods used so far, to >our knowledge) for very fast cooling, This is not a characteristic of vitrification per se. It is a characteristic of using current solutions which, because of their toxic nature (although much less so than previous solutions at the same ice forming concentrations), are used at less than fully vitrifiable concentrations. The fast cooling is done to skirt the boundary of crystal formation and toxicity both of which increase with time. In fact, instead of terming fast cooling a "disadvantage" it would be fairer and more accurate to say that the new CPA solutions are superior because they *allow* fast cooling to be advantageously done, whereas for some previous solutions fast cooling may have caused more damage because of lack of equilibration (uneven distribution of CPA throughout the tissue). Even if this was not the case, fast cooling (as with higher storage temperature - see below) would be more fairly looked upon as a general enhancement for all cryopreservation rather than as a specific need of vitrification. Ongoing research will likely obviate the need for such fast cooling as better (fully vitrifiable and minimally toxic) solutions are discovered and defined. Hopefully, this will enable cryopreservations to be done more cheaply and easily with less costly equipment and procedures, while still achieving fully restorable results. >for storage ideally at a temperature >(in the neighborhood of - 130 C) not easily maintained with great reliability >with equipment currently available, and for very fast and very uniform >rewarming to avoid "devitrification" (formation of ice crystals during >rewarming). Again neither of these are related to vitrification per se. The first is true for any cryopreservation of tissue. All current patients would be more viable (have a better chance of restoration in the future) if they had been stored at a higher temperature than that of liquid nitrogen. It is well known that liquid nitrogen was only used as a matter of convenience and to minimize storage costs. With respect to the major damage previously being done to patients by freezing it was reasonably deemed that the additional damage done by storage at that temperature would be insignificant in comparison. However, the damage being done by current methods is thought to be small enough that the additional damage done by storage at liquid nitrogen temperature would not be insignificant and that using a more optimal storage temperature is worth the added cost and complexity. The second (fast and uniform rewarming) is done for reasons similar to the fast cooling explained above and it too will likely disappear as better vitrification solutions appear. -- 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=15337