X-Message-Number: 560 Subject: Cryonics news from Trans-Time From: spectrx! (Edgar W. Swank) Date: Sun, 01 Dec 91 12:29:02 PST [Reprinted from The Immortalist - October, 1991] THE TRANS TIMES Research Update by Hal Sternberg, Ph.D. TRANS TIME and BioTime continue to find the small animal model [reviving hamsters following perfusion with cryoprotective solutions] very useful in improving cryonics suspension protocols. We have observed damage to the microcirculation, particularly noticeable in the brain, upon thawing and reperfusing blood into previously cryoprotected frozen hamsters. We have found that this brain damage can be prevented by using various cryoprotective solutions of relatively high molarity (about 3M and above), which cause excessive dehydration (observed visually). Solutions which lead to edema increase this damage and limit reperfusion to the brain. The cryoprotective solutions used for cryonic suspension by TRANS TIME have been tested in hamsters and lead to moderate dehydration of the brain and other tissues. Dehydration protects against freeze-damage and may be a positive step toward reversible cryonic suspension, as turtles which are freeze-tolerant undergo substantial dehydration before freezing. Our general knowledge of cryoprotection/freezing/thawing technology is improving. At the recent April conference of FASEB (Federation of American Societies for Experimental Biology) we reported a reproducible method for restoring strong rhythmic EKG signals along with heart beats from cryoprotected/frozen/thawed/reperfused hamsters. These hamsters were frozen overnight to between -1.6 to -2.2 deg. C. Even more recently we have restored heart beats and EKG signals from hamsters frozen to as low as -3.5 deg. C overnight. The restoration of this physiological function, which involves the coordinated participation of millions of cardiac cells (myocytes, nodal cells and Purkinje cells) indicates we are learning how to reduce freezing damage, a major obstacle of reversible cryonic suspension. -- (Edgar W. Swank) SPECTROX SYSTEMS (408)252-1005 Silicon Valley, Ca Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=560