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Jun. 4th, 2007 02:13 pmTo Treat the Dead
The new science of resuscitation is changing the way doctors think about heart attacks—and death itself.
"As recently as 1993, when Dr. Sherwin Nuland wrote the best seller "How We Die," the conventional answer was that it was his cells that had died. The patient couldn't be revived because the tissues of his brain and heart had suffered irreversible damage from lack of oxygen. This process was understood to begin after just four or five minutes. If the patient doesn't receive cardiopulmonary resuscitation within that time, and if his heart can't be restarted soon thereafter, he is unlikely to recover. That dogma went unquestioned until researchers actually looked at oxygen-starved heart cells under a microscope. What they saw amazed them, according to Dr. Lance Becker, an authority on emergency medicine at the University of Pennsylvania. "After one hour," he says, "we couldn't see evidence the cells had died. We thought we'd done something wrong." In fact, cells cut off from their blood supply died only hours later.
But if the cells are still alive, why can't doctors revive someone who has been dead for an hour? Because once the cells have been without oxygen for more than five minutes, they die when their oxygen supply is resumed. It was that "astounding" discovery, Becker says, that led him to his post as the director of Penn's Center for Resuscitation Science, a newly created research institute operating on one of medicine's newest frontiers: treating the dead.
Biologists are still grappling with the implications of this new view of cell death—not passive extinguishment, like a candle flickering out when you cover it with a glass, but an active biochemical event triggered by "reperfusion," the resumption of oxygen supply. The research takes them deep into the machinery of the cell, to the tiny membrane-enclosed structures known as mitochondria where cellular fuel is oxidized to provide energy. Mitochondria control the process known as apoptosis, the programmed death of abnormal cells that is the body's primary defense against cancer. "It looks to us," says Becker, "as if the cellular surveillance mechanism cannot tell the difference between a cancer cell and a cell being reperfused with oxygen. Something throws the switch that makes the cell die."...
Ни фига себе открытие. Факты как бы известны давно - теперь они объяснены. И что теперь? Ведь это же означает, что можно делать операции на практически мертвых людях, а потом их оживлять. Вед это же означает. что, в принципе, можно будет и голову пересаживать.
The new science of resuscitation is changing the way doctors think about heart attacks—and death itself.
"As recently as 1993, when Dr. Sherwin Nuland wrote the best seller "How We Die," the conventional answer was that it was his cells that had died. The patient couldn't be revived because the tissues of his brain and heart had suffered irreversible damage from lack of oxygen. This process was understood to begin after just four or five minutes. If the patient doesn't receive cardiopulmonary resuscitation within that time, and if his heart can't be restarted soon thereafter, he is unlikely to recover. That dogma went unquestioned until researchers actually looked at oxygen-starved heart cells under a microscope. What they saw amazed them, according to Dr. Lance Becker, an authority on emergency medicine at the University of Pennsylvania. "After one hour," he says, "we couldn't see evidence the cells had died. We thought we'd done something wrong." In fact, cells cut off from their blood supply died only hours later.
But if the cells are still alive, why can't doctors revive someone who has been dead for an hour? Because once the cells have been without oxygen for more than five minutes, they die when their oxygen supply is resumed. It was that "astounding" discovery, Becker says, that led him to his post as the director of Penn's Center for Resuscitation Science, a newly created research institute operating on one of medicine's newest frontiers: treating the dead.
Biologists are still grappling with the implications of this new view of cell death—not passive extinguishment, like a candle flickering out when you cover it with a glass, but an active biochemical event triggered by "reperfusion," the resumption of oxygen supply. The research takes them deep into the machinery of the cell, to the tiny membrane-enclosed structures known as mitochondria where cellular fuel is oxidized to provide energy. Mitochondria control the process known as apoptosis, the programmed death of abnormal cells that is the body's primary defense against cancer. "It looks to us," says Becker, "as if the cellular surveillance mechanism cannot tell the difference between a cancer cell and a cell being reperfused with oxygen. Something throws the switch that makes the cell die."...
Ни фига себе открытие. Факты как бы известны давно - теперь они объяснены. И что теперь? Ведь это же означает, что можно делать операции на практически мертвых людях, а потом их оживлять. Вед это же означает. что, в принципе, можно будет и голову пересаживать.
