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Why do scientists create a hybrid of animal and human?

Why do scientists create a hybrid of animal and human?Transplanting animal organs people can solve the pressing problems of Transplantation. And to identify new, including the emergence of unknown dangerous diseases is not the worst thing.

According to statistics from the World Health Organization, the number in need of donor organs has increased in the world five times in the last 12 years. According to an official government report on transplantation in the United States every day donor organs receive 79 and 18 people die, without waiting for them. And this in a country with the most developed transplantation system. Growing artificial bodies - it is a distant prospect. Therefore, in the scientific community are increasingly discussing the idea of xenotransplantation, growing human organs in animals. It can be the best technology for the salvation of men, yet biologists are learning to create organs using tissue engineering, said a representative of the National Institute of Heart, Lung, and Blood USA (NHLBI) Dr. Muhammad Mohiuddin.

First create a live Japan factory
The essence of xenotransplantation is the following: the induced (.. Ie reprogrammed from other species, such as reproductive) human stem cell is introduced into an animal embryo. Then, a combination of animal embryo implanted female. The result is a breed with suitable organs for transplant. Professor Alan Flake from the Children's Hospital of Philadelphia in which established xenotransplantation lab calls a good survival rate among the main advantages of the technology: grown in the animal human organs will not be rejected after transplantation.
Over the development of this field of transplantation work such renowned organizations as the American Mayo Clinic, biotech company United Therapeutics, Novartis and others. However, so far the most important achievement is the work of specialists of the National Heart Institute, lung and US blood (National Heart, Lung and Blood Institute, NHLBI), successfully transplanted genetically modified pig heart baboons.

After the scientist Shinya Yamanaka in 2012, he won the Nobel Prize in Physiology or Medicine for research on stem cells, regenerative medicine has been announced in Japan, one of the priority directions of science. Country Japan prefers not to publicize the results of its developments in the field of xenotransplantation. But that it may become the first country in the world where grown in the animal organs will be transplanted to people. In any case, the Council for Scientific and Technological Policy of the Government of Japan has already appealed to the Cabinet of the relevant authorizations.

How to grow new organs
More information about these studies voiced States. It is for these data, we can judge how far advanced the respective surveys. One of the most resonant events in the scientific world began to research scientists led by Ismail Zanjani of the University of Nevada-growing "humanised" organs in the body of sheep. Initially, the scientists set themselves the goal to find out whether it is possible to "fix" the embryos with genetic defects by introducing them healthy stem cells. However, in the course of experiments Zanjani realized that this technology can also be used for the cultivation of donor organs.
The idea of experience with sheep based on the research of experts from Children's Hospital of Philadelphia, who showed that human bone marrow stem cells can theoretically take root in sheep and become a part of the heart, the skin, muscles and other organs. Zanjani team managed to achieve a surprisingly high proportion of human cells in some organs of animals. The problem is that, as it turned out, in some cases, human cells lose functionality or bind to cells of sheep, and no one knows what consequences it may bring. Zanjani has not yet managed to find a way out of the situation.

Robert Kloner, an expert on heart disease at the University of Southern California in Los Angeles is sure: if we can grow heart cells in animals, it will be a major breakthrough, since it would create embryonic heart cells to conventional therapy. The technology has already proven its effectiveness in the treatment of heart disease in mice and rats. The problem is that at present the only source of human embryonic heart cells is a human fetus. Scientists hope that Zanjani technique will help solve the ethical problem.

According Zanjani, using his method can grow a wide variety of tissues, such as the cells that produce insulin to treat diabetes. Over time, it supposed to significantly increase the proportion of human cells in experimental animals the organs that allow such bodies to better take root. Now scientists are trying to find the types of stem cells that are most effective for the formation of an organ.

The best donors are the pigs
Much more progress has been made to scientists, growers organs in pigs. These animals are considered to be best for experiments in the field of xenotransplantation: its DNA is similar to human, and the authorities alike as an anatomically and functionally. Therefore, the main experiments are carried out precisely with these animals. So, a group of scientists headed by Professor Stanford and the University of Tokyo Hiromitsu Nakauti in August of this year, the beginning of the experiment on the cultivation of human organs in the body of a pig using stem cells. At a certain chemical action, they are able to regenerate into any type of cell, which theoretically can be grown in the laboratory for different organ tissues. However, their subsequent transplantation in humans can cause cancers, however this technique has not yet been used.

Hiromitsu Nakauti began with the reconstruction of the pancreas. He modified fertilized egg swine: an animal that was not in the future porcine pancreatic cells responsible for this have been removed. Then, in the adult uterus embryo introduced at an early stage with the replacement of missing stem cells of human prostate cells. They are adapted to the pig body that leads to the development of the human pancreas. If successful application of this technology in regenerative medicine will be possible in the coming years. Scientists plan to grow in this way and other tissues and organs for subsequent transplantation to man.

Experiment with the pigs and the company United Therapeutics: its experts are trying to find an effective way to treat serious lung diseases through transplantation. Founder and CEO Martin Rotblatt company hopes that with time can be successfully transplanted pig lungs man. According Rotblatt to make pig lungs biocompatible with the human body, you need to perform about 12 Genetic modification of porcine genome without this organ rejection occurs. United Therapeutics has successfully made six of them. Experts are also promising developments in xenotransplantation of kidney, liver, heart and corneas. United Therapeutics also involved in the modification of porcine cells, whose heart was successfully transplanted into monkeys, scientists from the NHLBI.

The dangerous of "animal" combining
The use of animals as living factories for the production of cells and organs for humans causes a lot of controversy and raises many ethical questions. For example, if a sheep is with human brain cells, a sheep, or it is already partially man? Interestingly, for the study of this subject in the United Kingdom and Canada created a special commission, the composition of which is not only scientists, but also journalists, lawyers and other specialized professionals.

There are also concerns that xeno-transplantation may lead to chimerism. Transplanted from animal organs are composed of cells that are theoretically able to migrate on the human body and to modify it outside the transplanted organ. That is a result of the transplantation of organs from animals to humans can change the physiology of the recipient. Some experts do not rule out that a transplant taken from an animal body is capable of unpredictable change mentality and emotional sphere of man. Consequently, preconditions for the emergence of inter-specific hybrids of humans and animals.
Finally, we should not ignore the risk of possible transmission to humans through animal DNA of dangerous diseases. This is one of the main reasons why xenotransplantation, despite obvious successes in this area, does not develop until quite effectively.

Ksenotransplantologii Supporters say that the necessary level of security is able to provide a thorough selection and selection of donor animals. The best solution may be to create a specialized pig farms operating on the organ transplant program. Whatever it was, xenotransplantation technology will provide a great future, because the engraftment and preservation of a healthy donor organ without a permanent cure for the subsequent life - is too tempting prospect, to abandon it.
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