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Past Shows
February 11, 2006
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Cool Science: Making Humans Hibernate
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Arctic Ground Squirrel may hold secret to human hibernation |
One of the biggest challenges still facing medicine is the lack of time to deal with traumas. After a heart attack, or massive wound, the speed with which someone receives treatment has a huge impact on whether or not they survive. If there were ways to essentially freeze time for a victim, then maybe we'd have a better chance for reviving them. One way to accomplish this, is to slow down their metabolism. With a slower metabolic rate, the body doesn't break down as quickly. The brain, heart and other major organs don't start to decay as quickly as they would under normal, higher metabolic conditions.
In nature, this slowing of metabolism occurs naturally every winter. It's called hibernation. Dr. Hannah Carey, a physiologist at the University of Wisconsin, Madison, studies hibernation in a variety of animals. She says there's a whole suite of physiological processes that change as an animal enters the state of hibernation. It turns out these processes are controlled by genes that are present in all mammals, including humans. If we knew more about these genes, it's possible we could manipulate them to create hibernation states in non-naturally-hibernating animals.
Another researcher who's looking at hibernation in animals is Dr. Ken Storey, a Canada Research Chair in molecular physiology at Carleton University. He's been identifying the proteins and genes that are turned on and off as an animal enters hibernation. With the work he's doing he's finding ways we may be able to slow down time for individual organs. This would extend out the time they'd be useful for transplant. Right now, many organs go to waste after they're taken from donors because we don't have long enough to transfer them to where they're needed. Dr. Storey sees a day when we'll be able to bathe these organs in drugs which make the organs hibernate, extending their life span by hours or even days.
Hibernation in whole humans is more complicated than in individual organs. But Dr. Hasan Alam, a trauma surgeon at the Massachusetts General Hospital in Boston, is looking for ways to replicate the effects of hibernation. He's working with pigs as his test subjects. In his trials he's replacing the pig's blood with a cold fluid that rapidly drops the animal's core temperature. This forces the heart to stop beating, brain activity to drop to undetectable levels and the animal appears dead. Remarkably, just by adding warm blood back into the pig, he's able to revive it. He sees this technique being useful for treating gun shot wound victims who have already lost most of their blood, and who usually die before they reach the hospital.
Dr. Mark Roth, from the Fred Hutchinson Cancer Center in Seattle, Washington, is taking a slightly different approach, but reaching a similar goal. He's found that giving mice a small dose of hydrogen sulphide forces them into hibernation. Like Dr. Alam's pigs, Dr. Roth's mice dramatically reduce their heart beat, brain activity slows right down and the animals cool to just above room temperature. And, after several hours, they can return to being perfectly normal.
Within just a few years these techniques could be applied to human beings.
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Grandpa T. Rex
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Artist's rendition of Guanlong Wucaii - Courtesy, Zhongda Zhang/IVPP |
A group of paleontologists, including Dr. David Eberth, the head of Sedimentology at the Royal Tyrrell Museum of Paleontology in Drumheller, Alberta, has unveiled the earliest known fossil relative of the fearsome Tyrannosaurus rex. The exquisitely preserved, 160-million-year-old dinosaur was discovered in the western Chinese desert. It's been dubbed Guanlong wucaii, and is far smaller than T. rex, but sports a unique crest on its head. Dr. Eberth says this dinosaur was also likely feathered, and lived quite close to the time when its lineage of dinosaurs gave rise to the first birds.
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Chemicals in the Air
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PFOA has been found in polar bears |
They're in our homes, in our bodies, and even in the blood of polar bears in the far North. Now a Canadian environmental chemist believes he’s found an explanation for how persistent, bioaccumulative and potentially toxic fluorochemicals have gotten there. And policy makers are listening to Dr. Scott Mabury. The Environmental Protection Agency in the United States has recommended that industry reduce emissions of one such fluorochemical, known as PFOA. Right now, PFOA comes from the production of many consumer products, such as stain-resistant carpets, water-resistant clothing and even microwave popcorn bags. Dr. Mabury is a professor and chair of the Chemistry Department at the University of Toronto.
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Question of the Week: Watering Plants
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This week, Shirley Wildenbeest from Kingston, Ontario writes: When I take a cutting from a plant to make a new plant, I place it in water. I can often leave the newly rooted plant in the water and it survives. But when I over-water potted plants, they die. Why can a plant survive in pure water but be killed by over-watering when potted?
For the answer, we go to the University of Guelph where Dr. Larry Peterson is Professor Emeritus in the Department of Integrative Biology.
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