[extropy-chat] [>Htech] The Doctor Will Freeze You Now (fwd from eugen at leitl.org)

[Eugen Leitl]

----- Forwarded message from Eugen Leitl <eugen at leitl.org> -----

From: Eugen Leitl <eugen at leitl.org>
Date: Wed, 5 May 2004 17:26:10 +0200
To: transhumantech at yahoogroups.com
Cc: forkit! <fork at xent.com>, decryo at detrans.de
Subject: [>Htech] The Doctor Will Freeze You Now
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Reply-To: transhumantech at yahoogroups.com


http://www.wired.com/wired/archive/12.05/biotime.html?pg=1&topic=biotime&topic_set=

The Doctor Will Freeze You Now 

How low-temperature surgery could kick-start the cryo game.

By Wil McCarthy

"I should prefer to an ordinary death, being immersed with a few friends in a
cask of Madeira, until that time, then to be recalled to life by the solar
warmth of my dear country! But in all probability, we live in a century too
little advanced, and too near the infancy of science, to see such an art
brought in our time to its perfection."

Benjamin Franklin wrote these words in 1773. And what if the old guy was onto
something? What if life had a Skip button, like the one on your TiVo? Then
you could go offline until next year, when your medication will be approved,
or next decade, when your bonds will have matured, or even next century, when
life is scheduled (finally!) to become perfect.

A company called BioTime shares the dream. BioTime deals in ultra-profound
hypothermia, the body's last stop before freezing. Suspended animation isn't
in the prospectus - yet. For the moment, this 10-person outfit is helping
doctors chill their patients during heart, brain, and vascular surgery, where
lower temperature translates into more available time on the operating table,
less potential for blood loss, and fewer post-op complications.

Major surgery can be hell on a patient, and procedures that require
interrupting blood flow can be the worst because they starve the body of
oxygen. To prepare for stopping the heart, for instance, doctors divert the
bloodstream through a heart-lung machine that circulates the entire blood
volume 30 to 60 times an hour. The machine can release air bubbles into the
bloodstream, bringing on cognitive loss and personality change. It also
ruptures red blood cells, spilling free hemoglobin into bodily organs, where
it's toxic. Meanwhile, white blood cells, finding themselves surrounded by
plastic tubing, go into a sort of immunological panic mode. The resulting
inflammation can cause capillaries to leak, especially in the brain.

One way to sidestep these issues is to minimize the body's oxygen demand, and
the simplest way to do that is to cool the affected tissues. This has spurred
a billion-dollar industry in therapeutic hypothermia, in which a dozen
companies jockey for market position. There are blood coolers and ice-water
baths, cold caps and water-circulating pads that adhere to the skin. Most of
these devices are designed to cool a specific area of the body. Some drop a
person's core temperature as low as 90 degrees. Any lower and blood thickens
to sludge while its proteins fold up into useless shapes, tempting
catastrophic circulatory dysfunction.

It's here that BioTime stands out from the pack. The company has developed a
process that cools living bodies much further than that. Fifty-six degrees
further, in fact, right down to the brink of freezing - a state in which the
brain takes hours, not minutes, to wither.

BioTime's secret is dumbfoundingly obvious: antifreeze. The company's
flagship product, Hextend, is an FDA-approved blood-volume expander designed
to maintain blood pressure and chemistry in the wake of massive blood loss.
It's used for this purpose in surgical wards throughout the US and Canada,
but the product has an additional property: It doesn't coagulate at low
temperature. Since 1992, BioTime has been testing Hextend in baboons, pigs,
and dogs, replacing their entire blood supply and then cooling them to 35
degrees. At that point, vital signs cease. Bleeding virtually stops.
Oxygen-hungry tissues go on a diet. Then technicians raise the body
temperature, reintroduce the blood, and shock the heart to life.

"Right now, we can easily bring animals back from two hours of absolute
clinical death," says Hal Sternberg, BioTime's VP of research. "No pulse, no
respiration, no measurable brain activity."

The astounding thing is that the animals show no sign of physical or
neurological damage. Over a period of weeks, the animal returns to its cute
and cuddly self.

The FDA hasn't approved BioTime's procedure for humans yet, but with Hextend
already on the market as a blood-volume replacement, Sternberg expects the
green light in as little as three years. And when that happens, it will not
only improve surgical safety, but also make way for longer procedures that no
surgeon would dare attempt at room temperature, such as separating adult
conjoined twins fused at the head.

BioTime has other cool stuff in the pipeline, including HetaFreeze, a
solution called a cryoprotectant. This substance makes it possible to freeze
tissue grafts - BioTime has tested it with skin and hair - without disrupting
their cellular structure. It may allow whole organs, such as hearts, and even
intact (but brain-dead) organ donors to survive partial freezing.

BioTime's story is neat, clinical, and investor-friendly, with a unique set
of medical technologies that have immediate utility. Clinical death for up to
15 minutes has been reversible since the 1952 invention of the defibrillator;
now BioTime is on the brink of extending that limit to hours. But with the
envelope pushing out further and further, the momentum is carrying the
company into stranger territory.

Especially given that Sternberg and his colleagues are longtime members of
the cryonics movement, whose techno-utopian, frozen-head agenda is well
known.

Like many R&D shops, BioTime's headquarters in Berkeley, California, is
strewn with half-finished projects. One involves a pair of table-mounted
pistons capable of generating up to 3,000 atmospheres of pressure.
Ordinarily, ice crystals rupture the cells of a frozen tissue sample, leaving
nothing but freezer-burned goo. But treated with cryoprotectant, suspended in
liquid nitrogen, and pressurized by these pistons, the tissue enters a
glassy, or vitrified, state from which it can be thawed and grafted onto a
living animal. In nature, frogs tolerate partial freezing for weeks on end,
and while Sternberg doesn't hold much hope for reviving such critters from
vitrification, he does talk about vitrifying and restoring their little
hearts.

Meanwhile, the company's cash flow derives mainly from Hextend, which is
manufactured and distributed by Abbott Pharmaceuticals in Chicago. Like many
blood-related products, it comes in clear 500-milliliter bags covered in tiny
blue print. This familiarity is reassuring, because for nearly 50 years the
task of blood-volume expansion has been handled by balanced electrolyte
solutions like ringers lactate - the basic fluid typically found in an IV bag
- or by simple solutions of starch and saline. But ringers lactate passes
  through the blood-vessel walls too easily, causing tissues to swell and
blood pressure to drop, and saline throws the body's electrolytes out of
whack. Hextend combines the best qualities of both products along with a
revitalizing shot of glucose.

Sternberg, who invented the solution along with other BioTime principals,
looks a decade younger than his 50 years. Indeed, he seems dedicated to
dodging the grim reaper at any cost. He exercises daily but avoids sports and
stays out of cars, and he eats a diet that can only be described as
eccentric: minimal fat, lots of protein, fiber, and sugar, and so much hard
green fruit that he rubbed his gums right off and had them surgically
replaced with grafts.

"Everyone is focused on molecular biology these days," he says. "Nobody is
thinking about gross physiology. We've got a worldwide patent and tremendous
customer loyalty. When surgeons try Hextend, they never switch back."

For a solution intended to make up for lost blood, Hextend is a surprisingly
inefficient transporter of oxygen. Blood carries 20 percent oxygen by weight;
BioTime's product holds only 0.3 percent, about the same as ordinary water.
Most people, however, have more red blood cells than they really need for
short-term survival, so diluting the circulatory system for a few hours of
surgery isn't a problem. This is especially true near the freezing point,
where Hextend, supplemented with sodium bicarbonate, potassium, and
magnesium, can safely replace the entire bloodstream.

"Metabolic needs are drastically reduced at these temperatures," Sternberg
notes. "As it turns out, 0.3 percent is more than enough. And the brain can
survive for hours on stored oxygen alone."

For test animals cooled for more than three hours, BioTime's success rate
drops below 50 percent. If this sounds untenable, keep in mind that for
patients with an inaccessible brain tumors, the alternative is certain death.

Nonetheless, the idea of popsicle patients horrifies experts who haven't
gotten used to it. "Thirty-five degrees?" says Jonathon Sullivan, an
assistant professor at Detroit Receiving Hospital who is familiar with
hypothermia's effect on the nervous system. "That sounds like a dead person.
The lowest survivable temperature we've seen from accidental hypothermia is
61 degrees, and that entails prolonged critical care afterward."

Still, Sullivan cottons to the idea after a few minutes of mulling. "There's
an old axiom of resuscitology," he says: "You're never dead until you're warm
and dead."

That axiom could be the motto of the cryonics movement. Nonetheless, the
medical establishment has shunned advocates of freezing bodies for eventual
revival. And who can blame them? Cryonics is just plain creepy.

The movement's roots reach back to the 1964 publication of Robert Ettinger's
The Prospect of Immortality, but the current chapter begins in 1972, with a
rift among the founders of Trans Time, a pioneering cryonics venture. One
Trans Time splinter, Alcor Life Extension Foundation, went on to become
supreme tabloid fodder in 2003 when it acquired the remains of deceased
baseball legend Ted Williams after a bizarre custody scuffle between his
children. Things took an even stranger turn when Alcor's former COO, Larry
Johnson, told Sports Illustrated that the company had mishandled Williams'
remains. Alcor insiders, he charged, joked about "throwing the body away" and
"posting it on eBay" to persuade the sports star's son to pay an outstanding
bill in excess of $100,000. Johnson himself later sold photos on his Web site
of Williams' severed head.

This kind of behavior explains why BioTime goes out of its way to distance
itself from cryonics. It's tricky, though, since BioTime has roots in Trans
Time, too. BioTime VP of operations and secretary Judith Segall insists,
"There's no association between the two companies." However, a 1992 Trans
Time newsletter trumpets a "close working relationship" with BioTime. "Drs.
Paul Segall, Hal Sternberg, and Harold Waitz, BioTime's principal
researchers, have a long affiliation with Trans Time," the document says.
Later, it notes that "Hal Sternberg is currently our vice president, and
BioTime secretary Judy Segall is also Trans Time's secretary."

BioTime founder Paul Segall - husband of Judith and brother of Trans Time
president John Segall - died in June 2003 from an aneurysm. Until the firm
appoints a new CEO, his business role has been assumed by his wife and his
technical functions by Hal Sternberg and Harold "Frosty" Waitz, another Trans
Time alum.

So it's hard to feel sure you're getting a straight answer when asking
Sternberg about the prospects for long-term suspended animation. "Oh, jeez,
that's a good question," he says. "For the next few years at least, I expect
the limits on a whole person might be two hours, or maybe slightly longer.
However, with a more substantial understanding of animals in a hibernating
state, we may be able to reduce the demand for food and oxygen dramatically.
There may be hormones or other things that could enable the body to tolerate
much longer periods."

How about freezing people altogether, I ask, conjuring an image of Woody
Allen in Sleeper. "Until somebody does it," Sternberg says, "we don't know if
such people would ever be revived."

Sternberg himself may be among the first to learn, because Paul Segall is
frozen right now, in a liquid nitrogen dewar on Trans Time premises in San
Leandro, California.

Many cryonicists speak of their frozen kin in the present tense, as if
entering suspension were something quite different from dying. Sternberg
doesn't do this. In talking about his departed friend and partner, he makes
liberal use of was and had and even the dreaded d-word itself. But in a
candid moment he affirms his faith.

"It may take a long time," he says, "but someday we'll wake Paul up."

As far as anyone knows, there's nothing physically impossible about reviving
a frozen head. Still, when you get down to it, Alcor and Trans Time are
taking money for a service that may never exist, and that even the companies
themselves estimate is 150 years down the road. BioTime is approaching the
problem from the other end - the respectable end - by working to extend
established medical procedures. The immediate benefit will be preventing
untimely death in the here and now, which is a completely different
proposition than resurrecting the already dead.

On the other hand, to give the envelope - any envelope - a meaningful nudge,
you have to be a little bit crazy. You need to walk the knife-edge between
the unlikely and the impossible. You need to dream. NASA has always been keen
on hibernation for long space voyages, à la Aliens and 2001: A Space Odyssey.
Indeed, several NASA documents cite a 1995 article in the Journal of
Gravitational Physiology called "Low Temperature Preservation and Space
Medicine." The authors? Paul Segall, Hal Sternberg, and Frosty Waitz.

With a bit of prodding, Sternberg describes the outline of his daydreams.
"You can also freeze small tissues and all kinds of single cells
indefinitely, and it has been shown that bacteria can travel on a meteorite
in a frozen state. How long? With enough research, I think the answer is
indefinitely."

But who would risk their own neural integrity on such experiments?
Ironically, given the need to preserve donor organs for as long as possible,
brain-dead accident victims may lead the way in whole-body cryobiological
research. The day may not be far off when we freeze these cadavers for
transport, then thaw them and place their revived organs into the bodies of
deeply hibernating transplant patients.

When this becomes routine, the next survival boost will come from freezing
prospective organ recipients when death is imminent and no replacement organ
is available. We'll pause their lives for weeks, months, maybe even years.
And once we've done that, can the stars themselves be far behind?

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07078, 11.61144            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
http://moleculardevices.org         http://nanomachines.net



----- End forwarded message -----
-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07078, 11.61144            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
http://moleculardevices.org         http://nanomachines.net
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