Release date: 2017-06-01
Human regenerative capacity is likely to be realized in the future, but not far away. In the near future, limb regeneration will become part of the medical toolbox. At present, the latest research by scientists has found important clues about the weight of human limbs.
è¾èžˆ is a mysterious creature in nature that can regenerate the resected limbs
According to foreign media reports, if you cut off your legs, they will grow up again, but humans do not have such ability, the reason is not simple, to a certain extent full of mystery. David Gardiner, a professor of developmental and cell biology at the University of California, Irvine, said: "In fact, we humans also have the ability to regenerate, such as epidermal tissue. In addition, the human body can regenerate part of the intestinal mucosa. But humans cannot regenerate more complex body tissues."
Gardner spent decades studying the regenerative capacity of cockroaches and looking for potential mechanisms for this superpower. He said: "Human regenerative capacity is likely to be realized in the future, but not far away. In the near future, limb regeneration will become part of the medical toolbox."
This is because, in theory, human limb regeneration is possible, for example: skin, if the skin is not deep, it will not leave scars, because the body can regenerate skin cells during self-healing. At the same time, if the cells under the nails are still intact, humans are likely to regenerate the front part of the finger. If these tissues are re-growth, the bones will be well combined, which is like a screw and a screw cap. Human liver can also grow and regenerate and rebuild damaged tissue.
Growing a complete limb
Limb regeneration (like the ability to regenerate sputum) is not only a replacement for tissue parts. Limb regeneration requires bones, muscles, blood vessels and nerve tissue. Adult stem cells are an undifferentiated cell that has a special effect on regenerating muscle tissue, but they not activated. Gardner pointed out that you can regenerate blood vessels, even nerve tissue, but not the entire arm.
Stephane Roy, director of the vertebrate tissue regeneration laboratory at the University of Montreal in Canada, stresses that human skin, liver and bones do not regenerate in the same way. Humans can only regenerate superficial tissues of the skin (in fact, this continuous process is called homeostasis), and most of the dust in the bedroom is the dead skin cells of the human body.
Liver regeneration is completely different from the limb regeneration of the sputum. Liver regeneration is a compensatory hyperplasia, which means that the volume it grows is part of the tissue that compensates for the loss, meaning that the liver tissue will grow larger, but if the whole liver is removed It will be impossible to regenerate. The lost part of the liver is not regenerative, so the liver part cannot be re-examined. In contrast, the limbs of the tendon can be re-examined multiple times, and new limbs can be re-growed with each resection.
Humans have regenerative capacity
Gardner pointed out that the fetus can form a complete organ system in the uterus, and obtaining some genetic information from the embryo can develop into a complex baby in only 9 months. Therefore, humans have the ability to regenerate certain organ tissues, and at the same time, from an evolutionary perspective, humans need self-healing functions.
In addition, the underlying genetic mechanisms of sputum and humans are not completely different. The 360-year-old Devonian period and the common ancestral species of humans have evolved branches. Gardner said: "There is no special for limb regeneration. There are many evolutionary processes in genes, but humans have at least not completed an evolutionary step."
In order to regenerate a limb, the cell needs to know where the regenerative limb is, at the tip of the finger, or at the elbow joint? They need to reconstruct the correct structure in the correct sequence. Gardner said that cockroaches have certain genes, but they are in a "closed" state in the human body. Perhaps these genes can regenerate, or at least help control the regeneration process. Some genes in the evolutionary process of humans do not express the ability to regenerate like scorpion genes. No one knows what these recessive genes are.
In 2013, Australian scientist James Godwin may unveil some of the mystery of limb regeneration. He discovered that macrophages can prevent the accumulation of scar tissue in the body, and macrophages exist in humans. In other animals, it is part of the immune system. Their function is to stop infection and cause inflammation, which is a signal that the body part needs to be repaired. If the body lacks macrophages, it will not be able to regenerate their limbs, but only scars.
Gardner said that Godwin's research work helps us to further understand the phenomenon of limb weight. Under normal circumstances, sputum does not form scar tissue at all. When human muscles tear or form a deep wound, it will damage the connective tissue. Tissue that promotes the formation of scar tissue. These scar tissue does not provide the same functionality of the original tissue.
He said: "If I can make a scar on my body, it will be a great thing, because it will reveal the mechanism by which humans cannot regenerate their limbs or organs. Macrophages may have some associations, but it is not entirely due to this factor. of."
Juvenile continuation and limb regeneration
The ability of "young continuation" may reveal the mystery of limb regeneration in another way. Mexico has a continuation of juvenile continuation, meaning that they still maintain their infancy characteristics as they enter adulthood. This is why Mexico still retains clams after maturity, while other alfalfa species do not.
Humans also have a continuation of juvenile continuation. This is why adults sometimes have a "child" in their inner self, while other primates do not. At the same time, humans have longer maturity than other primates, and are likely to continue and regenerate. There is some correlation between capabilities. Gardner stressed that young people are more likely to heal themselves than older people.
In addition, researchers at Harvard Medical School in the United States have discovered the "Lin28a" gene, which is activated in juvenile animals (including humans), and its activity will stop as the animal enters adulthood. This gene ensures that mouse tissue is regenerated, or at least Re-grow the tip of the toe and the ear. Once these animals are older than 5 weeks, they will not regenerate those tissues, even when the Lin28a gene function is activated. The Lin28a gene is part of the mouse's metabolic control system, and when stimulated, it will give animals more energy as if they were younger.
However, the inevitable correlation between the continuation of the young and the regeneration of the limbs is still uncertain. All the alfalfa species can be regenerated, but only the Mexican cockroach has a continuation feature. Alfalfa species are able to regenerate stem cells and begin to gain limb weight. This type of cell reacts with the wound and correlates with the limb's re-growth. Gardner stimulates the growth of nerve cells at the wound, allowing the limb to grow extra limbs.
Roy said: "This may be related to a strong immune response, or to some specific growth factors and their binding factors, which will partly answer a biophysical phenomenon: in terms of body proportion, the limbs are smaller than the human limbs. However, frogs cannot regenerate their limbs, so this is not a problem related to body shape. At present, the ability of animal limb regeneration is still an unsolved mystery, at least for scientists at present.
Source: Sina Technology
Calcium Ethoxide CAS No.2914-17-2
Calcium Ethoxide Basic Information
CAS: 2914-17-2
MF: C4H10CaO2
MW: 130.2
EINECS: 220-828-8
Mol File: 2914-17-2.mol
Calcium Ethoxide Chemical Properties
Melting point >170°C (dec.)
Safety Information
Risk Statements 11-14-36
Safety Statements 8-16-26-43
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