X-Message-Number: 2947 From: Date: Thu, 28 Jul 94 16:00:18 EDT Subject: SCI. CRYONICS sheep stages 3,4 Dr. Pichugin and Dr. Zhegunov have completed their report of the 3rd stage of their repetition and extension of the Cryonics Institute sheep head work--freezing to liquid nitrogen temperature and thawing again, but without perfusion--and also a very brief initial report on the 4th stage, wash/perfuse/freeze/thaw. The full reports will appear in THE IMMORTALIST, but part may be delayed past the September issue (mailed in August) if we do not have the photos in time; and the final report will also depend on timing of receipt of the final set of photos. Very briefly, after freeze/thaw WITHOUT perfusion (but using the slow cool/warm procedure that CI used) no cracks were observed at the visible level, but severe damage was observed with both the light microscope and the electron microscope. Details are given. As far as we know, there is nothing very new here, although we still have to study the details. In the very brief initial report of the 4th stage, however--freeze/thaw according to the Cryonics Institute sheep head procedure, including perfusion with glycerol--again no cracking was observed at the visible level. This confirms our observation, and is in clear contrast to results with human patients by other procedures where cracking was observed at all levels, including sizable cracks in skin and surface tissues. They report also that they did not have success in washing out the glycerol after thawing. We await the results of the microscopic examination of the 4th stage, and of the assessment of glycerol concentration in the brain tissues. Then we may be able to decide whether the CI procedures provided any on-balance benefit, compared to others, and whether improvements suggest themselves to be tested. Robert Ettinger Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2947