X-Message-Number: 5856 From: (Daniel Jacobs) Newsgroups: sci.cryonics Subject: Freezing Damage Date: Wed, 28 Feb 1996 14:36:28 +1000 Message-ID: <> Although I am generally very sympathetic to the concept of cryonics and can see no fundamental scientific reason for it not to succeed I was very worried by what I read in the BPI Tech Brief 16: "Canine Brain Cryopreservation" by Charles Platt. To quote of the damage found in the canine brain: "Further, the etiology of these tears appears different between the two groups; in the frozen thawed groups the fissures or tears are relatively neat edged, the spaces contain minimal debris and the edges appear complementary, like two halves of a torn piece of paper. Perhaps the degree of "match" between the sides of these fissures could be best characterized by the degree of "match" observed in orbital photographs of continents experiencing millions of years of continental drift; that the patterns are related is obvious, but the match is not precise." "While there is much ultrastrucural and histological preservation in evidence in the micrographs obtained in this series, there is also evidence of considerable damage. Particularly disturbing are the continued presence of large (5 to 15 micron diamater in cross section) tears of unknown "depth" in both the grey and white matter. Dehydration of structures and the presence of what appear to be free nuclei and lysed glial cells are also disturbing." As these dogs were preserved using the current BPI protocol under near ideal conditions it is indeed "disturbing". In response I have the following questions. 1. Has there been much thought been given to the protocol suggested by Drexler ie chemical fixation of the brain then subsequent vitrification? Would this not preserve maximum morphology and information? 2. Would the current cryonics organisations allow a patient to choose prior chemical fixation before freezing? 3. Has anyone investigated what percentage of people die; i) unexpectedly, ii) after prolonged periods of pre-death brain ischaemia, or iii) of a major brain trauma ie those people that are likely to suffer significant brain damage? Finally are most aware that medically assisted suicide is now legal in the Northern Territory ( a state of Australia) for those people suffering a painful terminal illness. Similar legislation is currently before the South Australian and New South Wales parliaments. Thanks -- Daniel Jacobs School of Microbiology & Immunology University of NSW 'I'm sorry but I don't have a pithy quote' Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=5856