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[EN VIDÉO] Stem cells survive the death of the organism Stem cells, undifferentiated, can form, by dividing and specializing, different types of tissue, which makes them promising for regenerative medicine methods. Researchers at the Institut Pasteur have discovered that they can survive for up to 17 days after the death of the organism. Surprised, biologists think that there are keys to better use them.
A feat achieved at the Yale School of Medicine redefines the concept of death. ” All cells do not die immediately, rather it is a long succession of events. It is a process in which we can intervene, stop it and restore certain cellular functions. says David Andrijevic, a neuroscientist at Yale School of Medicine. Restoring cellular functions, and even certain organs after death, is precisely what David Andrijevic and his colleagues have done thanks to a system called OrganEx. Their experience is the subject of a publication in Naturee.
Cells restored several hours after death
The OrganEx system pumps into the bodies of pigs, whose death was induced by depriving the animal’s organs of blood (ischemia) under general anesthesia, a liquid which replaces the blood. The composition of the liquid made it possible to restore the activity of certain cells and certain tissues one hour after the death of the animals. The heart cells were able to contract again. And regions of their liver and their kidneys also showed signs of activity. ” We were also able to restore circulation through all the bodies, which surprised us “, says Nenad Sestan, the director of this research.
Concerning the brain, OrganEx made it possible to maintain its integrity but no electrical activity, a sign that the animal was conscious, was recorded. But scientists have observed movements involuntary movements in the muscles and necks of animals – movements that do not seem to be controlled by the brain but possibly by the spine. Researchers do not yet have a satisfactory explanation for this phenomenon, but it is clear that the animals were not resurrected.
Applications and ethical questions
The apps of OrganEx in human medicine are numerous, in particular to prolong the duration of life of grafts or treat an organ or tissue damaged by ischemia. If this feat augurs new advances, it also raises ethical issues, especially in the event that brain activity is restored after death. This experience underlines that death is not a moment, but a biological process that remains, to a certain extent, “treatable”. Our definition of this term may change as medical advances are made.
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