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Valery Spiridonov, for RIA News
Transplantation of the head is a technology that doctors, theologians, philosophers and, of course, people who need new ways of rehabilitation are discussing hotly this year. But what is behind this technology? Where is the “devil” who settled in the details of laboratory experiments? After all, information about these experiments is already published on the pages of respectable medical journals, such as Surgery and CNS Neuroscience & Therapeutics.
What exactly could make me and some scientists think that this operation was technically acceptable today, and the time has come for it?
Long before the appearance of Italian neurosurgeon Sergio Canavero from the newspapers, I learned the history of this kind of experiments. In the twenties of the last century, the Soviet scientist, physiologist, doctor of medicine Sergey Sergeyevich Bryukhonenko invented the first apparatus of artificial circulation and demonstrated in practice the possibility of maintaining brain life separately from the body. Then there were a number of experiments: the famous experiments on dogs and monkeys. But they all rested on the inability to regain mobility after transplanting the head to another organism.
However, I realized that such an opportunity, if it appeared, would be the last segment of a large puzzle. And people, whose physical possibilities in sick body are severely limited, will find a normal life.
Therefore, for me, the events of 2013 were logical and expected …
In the summer of 2013, Sergio Canavero, the continuer of the ideas of the Soviet scientist Vladimir Demikhov and the American Robert White, made a sensational interview and called a substance called polyethylene glycol, or PEG, a challenge to the previously unresolved problem of the “open circuit” of the spinal cord.
It is with his help that a scientist expects to connect up to 30% of nerve cells responsible for the transfer of vital impulses from the brain to organs and limbs. According to him, this will be enough to restore the basic motor functions of the body. Other details of this operation, such as splicing vessels and tissues, as well as the site of the spine, are not a significant barrier today. The question technically stood only in the return of mobility after the separation of the spinal cord.
It seemed to me interesting to learn the history of PEG, because it is from him now can depend success of the technology, in the development of which your humble servant also participates.
Worms, dachshunds and polymers
PEG is a synthetic polymer that has long been used in a number of industries, such as industry, pharmaceuticals, engineering, cosmetics. They use it even as a component of solid rocket fuel. But in the context of the topic we are interested in developments with the use of PEG in medicine, which have a longer history than it might seem.
Polyethylene glycol is non-toxic, it dissolves in water. In medical doses does not have a negative effect on the human body.
The first mention in literature about the use of this substance in the role of the so-called fusogen, a preparation providing the fusion of separated neural tissues, dates back to 1990. In the article “Accelerated Fusion of Separated Axons Using Polyethylene Glycol,” Professor of Neuroscience at the University of Austin, George Bittner described the effects of different versions of this drug with different molecular weights and concentrations on the “disconnected” nervous system of the earthworm.
Bittner notes that when the two halves of the worm are closely juxtaposed and PEG is used as a “biotope” on the site of the nerve core, 80-100% cell fusion is achieved. Subsequently, he proves this by citing data from electron microscopes, where he demonstrates the integrity with the help of a special dye launched through the nervous system. In a control sample without the use of PEG, cell integrity under identical conditions is not observed. Even then, George Bittner suggested that this technology can be scaled and used for mammals.
In December 2001, the journal Neuroscience Research published an article by Richard Borgens and Debra Bohnert (Richard Borgens, Debra Bohnert) entitled “Rapid recovery from spinal cord injuries using polyethylene glycol.” The article deals with experiments on guinea pigs, where PEG was used as the artificial “cement” for damaged membranes of disconnected axons, stopping their decay.
In all likelihood, PEG also prevents the formation of a scar at the site of the incision of the spinal cord, which under normal conditions completely blocks the conductivity of nerve impulses. The authors of the article argue that, when administered through the vascular system, the polymer concentrates at the site of the rupture, passing untouched areas and causes spontaneous growth and the union of up to 20-30% of cells in the spinal cord of animals. Scientists also reflect on the use of this method of treatment for brain injuries and strokes.
Then, in December 2004, Richard Borgens publishes in the journal Neurotrauma a report on research on dogs, giving hope in the treatment of paralyzed people. He shows the public an extremely promising video in which dogs of different breeds after back injuries regain the ability to walk for several weeks of treatment with PEG, moving from complete paralysis to almost normal mobility.
Three of the four animals managed to be saved by the introduction of the polymer within 72 hours from the time of injury. The treatment was combined with the usual in such cases, therapy with back injuries. Standard treatment includes the surgical removal of fragments of damaged bones of the spine and further physiotherapy procedures, such as swimming.
According to Borgens, brain cells have the ability to send a “suicidal” signal located next to the injury to neurons, causing more serious damage than the trauma itself. However, PEG, when applied in a timely manner, is able to interrupt this “cascade of outages,” restoring the membrane, or facilitating the fusion of two damaged cells into one large, and functioning, nerve cell.
Borgens argues that positive changes were seen already on the fifth day after the start of treatment. The study involved 19 dogs aged from 2 to 8 years. The control group was built on the basis of historical data on dogs with similar injuries, since Richard Borgens did not want to inform the owners of the animals of the second group that their pets would not receive the treatment that they could.
Thus, it became obvious to me that the set of methods proposed by Sergio Canavero, including the key component – PEG – is not a sudden, not confirmed experimentally fiction of an eccentric Italian. For more than 25 years, the amazing regenerative properties of polyethylene glycol have been used in practice, and scientists have moved from experiments on worms to experiments on complex animals.
Should this lead immediately to the possibility of a head transplant from one mammal to another? In my opinion, no. We will have to collect a few more puzzles of this picture, such as the influence of the patient’s DNA on the healthy body of the donor, the life expectancy after the operation, etc. However, when getting back injuries, this polymer, apparently, can return people to their usual life. There is still much work to be done to make this technology reliable and to provide confidence in the correct selection of the set of variables that are important for a successful outcome.
In addition, with old injuries, the use of only polyethylene glycol will not yield any results – the healed tissue can not serve as a signal conductor in any case. It requires the replacement technology for entire segments of the spinal cord. But even today it does not sound too fantastic.
And I note with undisguised satisfaction how, with the help of scientific knowledge and the will to live, we can turn limited opportunities into truly unlimited.
PEG is not the only unique substance used by Canavero and his colleagues in conducting experiments. Along with it, perfluorane, synthetic blood, is also used, a legacy of Soviet science, which, fortunately, despite its extremely difficult history, has not been forgotten, and after decades of research has found a place in modern medicine. Experts know about perfluorane today, it is sold in pharmacies. But the medical application of PEG, apparently, is the matter of the near future of orthopedics and traumatology.
The author’s opinion may not coincide with the editorial position
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