Freezing and Reviving of Humans NearsMay 6, 2004 Dave Eberhart, NewsMax.com
Science is close to freezing, and then reviving, human beings.
Wired magazine reports that one firm, BioTime, has been regularly bringing animals such as dogs, baboons and pigs back from a frozen near-death experience.Life After Death
"Right now, we can easily bring animals back from two hours of absolute clinical death," BioTime Vice president Hal Sternberg said.
Wired reports that the "the astounding thing is that the animals show no signs of physical or neurological damage. Over a period of weeks, the animal returns to its cute and cuddly self."
Sternberg expects to get the Food and Drug Administration's approval for such a process for humans within next three years.
The reports could have been lost on public attention because so much attention is focused on molecular biology these days, including human cloning.
But the growing frontier of more prosaic physiological science could be coming in from the cold, so to speak - which might have a great impact one our lives.
Even the terminology of one of medicine's most promising, albeit chilling, frontiers can get a little vexing. Low-temperature surgery or "therapeutic hypothermia," "ultra-profound hypothermia" and the sci-fi "cryonics" or "cryogenics" conjure up creepy images of baseball great Ted Williams' head bouncing around in freezers as his family argues over whether to keep him frozen or thaw and bury him.
Like the Williams controversy, freezing the dead or freezing live people and resuscitating them at a much later date are fraught with moral, legal and financial issues.
The idea of using freezing technologies is not new. Low-temperature surgery or therapeutic hypothermia has been around for some time. Since the early 1950s, surgeons and scientists have understood that cooling tissues minimizes the body's demand for life-sustaining oxygen to circulate via the bloodstream.
Here's the rub: During surgical procedures for the treatment of certain cardiovascular conditions such as large aneurysms, cardiovascular abnormalities and damaged blood vessels in the brain, surgeons must temporarily interrupt the flow of blood through the body.
But interruption of blood flow can be maintained for only short periods of time at normal body temperatures because many critical organs, particularly the brain, are quickly damaged by the resulting loss of oxygen.
The ubiquitous heart-lung machine that pumps and oxygenates a patient's blood, although a lifesaver, may rupture red blood cells releasing hemoglobin into organs with toxic effect.
Already in use in operating theaters are hosts of blood coolers, cold caps, clinging water-circulating pads and the mundane ice-water bath, all designed to cool the affected tissues and give surgeons more precious time to get in, do their work and close before the flesh begins to die of starvation.
The current outer edge of this therapeutic hypothermia, however, appears to be those appliances that can drop a patient's core temperature to as low as 90 degrees.
A device at St. Paul Heart Clinic in Minnesota, for instance, helps survivors of heart attacks save endangered heart muscle. The device, called "Innercool," chills the body to 91 degrees, so heart muscle starved of oxygen by a clogged artery doesn't need as much air anymore.
But go beyond that apparent 90-degree threshold and blood turns to sludge and deadly circulatory dysfunction creeps in.A New Breed of Pioneer
Enter BioTime, a company headquartered in Berkeley, Calif., that advertises that it "develops blood plasma volume expanders, blood replacement solutions for hypothermic (low temperature) surgery, organ preservation solutions and technology for use in surgery, emergency trauma treatment, and other applications."
Recently, BioTime was awarded a research grant by the National Heart, Lung, and Blood Institute division of the National Institutes of Health for use in the development of its "HetaCool" blood plasma volume expander.
The grant will be used to fund a project entitled "Resuscitating Blood-Substituted Hypothermic Dogs" at the Texas Heart Institute in Houston. HetaCool, a unique blood substitute with a sort of advanced anti-freeze component, is specifically designed for use at low temperatures. The goal of the BioTime research project is to use HetaCool to increase the time during which a patient may be maintained in hypothermic cardiac and circulatory arrest during surgery.
In the research project, the body temperature of dogs will be lowered to reduce their metabolic rate and related need for oxygenating red blood cells, while HetaCool will be used to replace the circulating blood to prevent the blockage of small blood vessels caused by the sludging of blood at low temperatures.
Such studies are nothing new at BioTime.
Years ago, the company made medical headlines by reviving baboons hours after their bodies were packed into crates of ice. The animals on ice had no pulse, no respiration and no measurable brain activity.
During those history-making procedures, the company used its flagship product "Hextend," a plasma replacement fluid that is poured into the body through a vein in the upper thigh as blood is drained and the anaesthetized body is cooled dramatically, down to 35 degrees. As the clear fluid permeates the tissues, it prevents the deterioration caused by extreme lowering of body temperature.
Although Hextend is already on the market as a successful, profitable and vaunted blood-volume replacement, dramatic suspended-animation procedures using the product have not been approved by the FDA for humans.
Visionaries, like Sternberg, see such progress as key to eventually allowing humans to preserve their ice-cold bodies in suspended animation and wake up years later in the same physical condition.
Space scientists investigating the possibility of interstellar travel are also intrigued as the technique could be used to "store" astronauts as they journey for years to destinations light years away.
And the military application is foreseeable - allowing critically injured troops to be near-frozen on the battlefield and preserved for later treatment.
Although BioTime routinely distances itself from creepy "cryonics," where the human body is frozen like a side of beef, the company admits that a plausible long-term objective is to add yet more sophisticated anti-freezing chemicals to its blood substitute solutions so human bodies can be indefinitely stored at -196C, the temperature of liquid nitrogen.
As things stand now, it's easy enough to freeze a body, but how to thaw it without irreparable damage to cells is a formidable roadblock. But once that roadblock is smashed, the brave new world of revival after clinical death could spring well beyond the hours-long window now being achieved in the animal revival experiments. Not 'Socially Acceptable,' Yet
"It is like the public attitude to early organ transplants," Sternberg once told the London Times. "Although everyone will love us when we announce we have reversibly frozen a human being, at the moment this area is not considered socially acceptable.
"There is a limit to how far people think you should go to save a life, but we already have children being born from frozen embryos. If you are extending the beginning of life, why shouldn't you also extend it later on?"
For the time being, however, BioTime is sticking with its suspended animation gig where ultra-profound hyperthermia is the ticket, not freezing.
Sternberg admits that even with this more modest approach, the prospect for really long-term suspended animation of humans will continue to be vague for the next few years:
"I expect the limits [over the next few years] on a whole person might be two hours or maybe slightly longer."
But hope and man's penchant for invention spring eternal, and research into the animal kingdom could eventually teach humans how to mimic the suspended-animation talents of some unique animals.
Sternberg says work on the mechanisms of animal hibernation has provided much of the basic information on suspended animation.
One type of North American frog, for instance, can partially freeze its body while it shuts down during winter. Lowly bacteria can travel through space frozen in a meteorite. And then we have the current mammal king of the deep chill, hamsters, which have been kept alive at 1-2C with no heartbeat in BioTime laboratories for up to seven hours before being successfully rewarmed.
Meanwhile, BioTime is making incremental steps forward. Science might not yet be sophisticated enough to freeze and thaw (without cell damage) a complete human being or even a detached human head, but progress is being made.
In BioTime's pipeline is "HetaFreeze," a so-called "cryroprotectant," which makes it possible to freeze tissue grafts. Already, BioTime has run successful tests with skin and hair without resulting cell damage.
Perhaps a human heart will follow, then perhaps --
A curious irony in BioTime's saga is that founder Paul Segall, who died in 2003 from an aneurism, is frozen in liquid nitrogen at a facility in San Leandro, Calif.
As Sternberg says, "It may take a long time, but someday we'll wake Paul up."
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