X-Message-Number: 5757 Date: Sun, 18 Feb 1996 22:21:57 -0800 (PST) From: Doug Skrecky <> Subject: Re: Mostly good news from Nederland In message #5740 Steve Bridge <> wrote: >One note of bad news: Bredo Morstel has been at -78 C for several >years instead of -196 C. That means that significant cell >deterioration continues to take place. While it is nice that >people are willing to help, this care is still far below the >standards of any cryonics company. Anyone else interested in >a do-it-yourself cryonics operation should be cautioned that being >independent may have its benefits, but safe and rational long-term >care of your relative is not one of them. I would like to amplify Steve's comments with the following observations. Storage at -78 C may have variable results depending on how the patient was treated. There seem to be four main options. Option #1: Pretreatment with cryoprotectants that are liquid at room temperature such as DMSO or glycerol. Since these have annealed glass transitions (Tg') of below -78 C significant deterioration can be expected to occur. For example glycerolized bone marrow cells maintain normal morphology at -69 to -78 C during the first year of storage. Deterioration becomes apparent in the second year and this becomes severe in the 3'rd year. (Cryobiology 1970:65-69) I do not know how Bredo Morstel was pretreated, but it does appear very likely that if glycerol was used that this patient is now nothing but a corpse. No revival will be possible and further maintainance at -78 C is pointless. Option #2: Freeze-drying. Option #3: Chemical preservation combined with low temperature storage. The Canadian Cryonics Society has in the past been involved in attempted permafrost burials. I have examined the two burials that occurred at Yellowknife, N.W.T. and determined that the corpses were interred in only seasonally frozen soil. However burial at colder sites is now feasible and permafrost burial remains a distinct possibility. However considering the damage induced by fixatives permafrost burial will be of interest only in cases where cryonic suspension in liquid nitrogen is not possible for whatever reason. Option #4: Pretreatment with cryoprotectants that are solid at room temperature. For example the Tg' for sorbitol solutions is -64 C. (Carbohydrate Research 1993 238:39-48) It is thought that deterioration of tissue will not occur to an appreciable extent over time spans of interest if storage temperature is below Tg'. It follows that little or no deterioration can be expected with storage at -78 C for tissue that has been pretreated with sorbitol. This is an important safety concern that I would like to see addressed by companies involved in the cryonics field. If storage temperatures above liquid nitrogen temperature are considered in the future there will be a much greater safety margin with solid cryoprotectants such as sorbitol over liquid cryoprotectants such as glycerol. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=5757