X-Message-Number: 6793
Date: 23 Aug 96 02:10:08 EDT
From: Paul Wakfer <>
Subject: Prometheus Science Method (update)
Prometheus Project Scientific Plans
Here are the latest Prometheus Project scientific plans. In considering
these plans one must bear in mind that the goal of the Project is necessarily
two-fold. First, to discover how to fully recover both brain and mind from a
state in which it could remain for decades without deterioration, and second,
to demonstrate that its mental faculties have been fully recovered in a
manner which will be convincing to scientists, to the media and to the
public. The goals of the Project are a challenge to both cryobiology to
reversibly preserve the brain, and to neurobiology to provide us with methods
to show convincing evidence of this.
The following description is my present understanding of how this will
be done. However, it should be clearly understood that this is preliminary
and is subject to many possible changes both before and after the Project
research has begun. Also it should be noted that while vitrification is
clearly the leading cryobiological technique which the research will be
utilizing, the Project scientists are well versed in all known cryobiological
methods and are totally open to using whichever method will work best to
achieve the Project goal (which itself says nothing about the method to be
used).
Phase I: Isolated Head Reversible Cryopreservation.
Phase I consists of isolated head experiments that are pre-requisites to
the Phase II head transplantation studies. The following tasks are planned to
be accomplished:
1. Determine what cryoprotective agents will and will not penetrate the
brain under appropriate conditions.
2. Determine how to load and unload these agents without precluding
perfusability and without producing significant damage to ultrastructure
and measures such as: EEG during blood perfusion in-vitro.
3. Determine means of cooling and warming isolated heads that do not
produce major injury beyond that caused by the delivery and washout of
the cryoprotective agents, and determine whether "cooling injury" is a
problem and, if it is, how to overcome it.
4. Refine evaluation methods including sophisticated neurobiological tests
such as: evoked potentials, voltage-sensitive dye-visualized voltage
distributions, LTP, etc. including auto-stimulation of the pleasure
center to see if reproduction of previous results is evoked.
In vitro perfusion with blood has several advantages over the Phase II
transplantation model, including the ability to eliminate white cells and
platelets, which could otherwise preclude assessment of cerebral (and even
superficial tissue) function, and the ability to lower hematocrit to permit
perfusion that otherwise would not occur. Something this modest might be
sufficient to convincingly demonstrate complete recovery of mental faculties
if the neurobiologists can give us sufficiently convincing tests to perform
on the in-vitro perfused brain. Another use of this model will be to
quantitate perfusion and other defects and learn how to overcome them.
The endpoint of Phase I will be a brain that has been cryopreserved and
stored and that survives cryopreservation based on a variety of convincing
in-vitro criteria, conceivably (but unlikely) even including signs of
consciousness. If the brain *can* be returned to consciousness in-vitro and
if superficial structures/sense organs are not destroyed, convincing evidence
for complete cryopreservation will have been achieved.
Phase II: Isolated Head Transplantation.
Phase II will involve the transplantation of isolated heads after
cryopreservation, storage and rewarming. Transplantation should allow us to:
1. Show the brain/head can reflow with blood for prolonged periods without
deteriorating.
2. Show the brain releases and responds to appropriate hormones.
3. Show the brain retains ultrastructure for prolonged periods.
4. Show that the brain survives based on all previous assays.
5. If superficial structures are not irreversibly damaged, wait for
consciousness (and possibly some brain IO) to return, if it is able to
within the time available before rejection sets in.
Phase III: In-situ Brain Perfusion and Cooling.
The purpose of Phase III is a demonstration of successful brain
cryopreservation which will be totally convincing to the media and the
public. It is not likely that this phase will even begin until year 8 of the
Project.
Summary:
In this stage the results of Phase I and II will be applied to the
still-connected brain of a dog. This will be done by:
a) perfusing the still-connected brain of a mammal with the already
developed and proven reversible vitrification solution,
b) cooling the brain to -70xC or as low as the model parameters allow, and
c) rewarming the brain and restoring the dog to a healthy state where full
recoverability of mental faculties may be convincingly seen.
Detail:
1. The experimental animal will first undergo preliminary operations and
recovery to modify the body-to-head vasculature to be more suitable for
the experimental procedure *without* compromising the viability of the
animal.
2. Using clamps, the vasculature of its head will be isolated from that of
its body, and the vasculature of its brain from that of its superficial
skeletal muscle, eyes, facial nerves, and ears to the extent that this
is possible. Vitrification perfusion will be applied to its brain, and
head/brain interface, while its body is maintained in mild hypothermia
with its blood intact, by either its own beating heart and a ventilator,
or with or without its own blood by a heart-lung machine.
3. The vitrification perfusion procedure will be followed by cooling of the
brain only, to -70xC by perfusion with cold perfluorochemical, or
irrigation of the brain surface with cold fluid by canulae inserted
through the skull, or both. A 70xC+ gradient from the superficial
tissues to the brain would be maintained in order to allow the sense
organs and the means of brain self-expression to be spared to the
greatest extent possible. Heat transfer calculations have verified that
such a temperature gradient can be maintained.
4. The head will then be rewarmed by perfusion with warm perfluorochemical,
together with vitrification solution washout and blood reinfusion at the
appropriate rewarming temperatures.
5. The head/brain/body vasculature isolating clamps will be removed, and
the whole animal will be rewarmed and revived.
6. Once sufficiently recovered, the dog will be kept alive until full
behavioral and intellectual/neurological assessment is possible.
7. Monitoring of the dog will be continued to assure long-term cerebral
integrity.
A Phase III Possible In-situ Alternative
If the above (admittedly ambitious) plans for Phase III are found not to
be achievable (a distinct possibility due to anatomical considerations), as
an alternative we will attempt to do whole-head perfusion and cooling with
the still-connected whole-head vasculature isolated from the body by
clamping. Even if recovery were not total this would give the advantage (over
Phase II) of a longer period (up to 3 weeks) post warm-up for evaluation of
the effects of the procedure.
Phase IV: Clean-up and Other Animal models
Phase IV is an open-ended continuation of the Project which will attend
to any imperfections remaining from Phase III and will move to other animal
models to verify species transferability of the results. It will probably
extend past the end of the ten year Project plan which quite naturally ends
with the achievement of the Project goals by the successful completion of
Phase III.
Yes, this is a tall order! There is no question that this whole Project
is on the leading edge of several branches of science and medicine. But then
the only way humanity ever progresses is by constantly and steadfastly
"pushing the edge of the envelop". In terms of both science and culture that
is just what The Prometheus Project is designed to do.
-- Paul --
!!!!! REVERSIBLE BRAIN CRYOPRESERVATION *CAN* BE ACHIEVED IN 10 YEARS !!!!!
Paul Wakfer email: Voice/Fax: Pager:
US: 1220 E Washington St #24, Colton, CA 92324 909-481-4433 800-805-2870
Canada: 238 Davenport Rd #240, Toronto, ON M5R 1J6 416-968-6291 416-446-9461
(currently in Canada)
Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=6793