X-Message-Number: 4613 Date: 06 Jul 95 02:55:20 EDT From: Mike Darwin <> Subject: CI Research Critique and Responses Fellow Cryonetters, I have attempted to post my critique of CI's sheep brain ultrastructural studies as well as Dr. Pichugin's responses to this critique. Dr. Pichugin has been very generous with his data and results, and we arereciprocating. Bob Ettinger of CI should already have a copy of some of our EMs (in the July 1995 CryoCare Report) and the posted and written report which accompany them. More pictures will be sent to both Bob and Dr. Pichugin as we get them scanned/printed. Dr. Pichugin should have a large package of material from us in about a week. While my report is critical of the CI results as reduplicated in Ukraine, I would emphasize several things: 1) There are many caveats about the work; simple changes in terms of post freezing/thawing handling can have an enormous impact on outcome. 2) It is not possible given the current data to seperate out damage due to freezing from that incurred during rewarming, prep for EM, etc. 3) BPI had a very hard time getting good EMs out of glycerolized tissue. This is quite an art; we finally got good pictures as a result of some clever post fixation handling techniques. Everyone on this list should be sophisticated enough to realize that this is not an attack of any kind. Indeed, Dr. Pichugin is currently underway with work on nonischemic sheep heads and viable brain slices using similar techniques. Further, he has apparently demonstrated viable electrophysiology in brain slices following cryoprotection, freezing and thawing. Obviously, much added research is needed. We are happy to report such comparatively good results with our protocol. I say comparatively good results: much remains to be done, and the results (even though we believe them to be the best so far) are far from ideal. Mike Darwin BioPreservation 10743 Civic Center Drive Rancho Cucamoga, CA 91730 (909)987-3883 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4613