On March 20th, after the scientists successfully developed the chimera of human and pig for the first time last year, scientists at Stanford University in the United States recently introduced human stem cells into sheep embryos and obtained human and sheep chimeras. The research team has successfully The pancreas was transplanted into mice. On March 15th, Liu Zhonghua, professor of the College of Life Sciences of Northeast Agricultural University and director of the Livestock Embryology Engineering Laboratory, told the Science and Technology Daily reporter that despite the controversy over ethical issues, this breakthrough result may help alleviate global organ donation. The shortage problem. Significant or may cultivate human organs in animals In the United States, about 76,000 people are waiting for organ transplants. In the UK, this figure is 6,500, and each patient may have to wait for 5 years or more. On average, 32 patients die every day while waiting for organ donation. Previously, although scientists have successfully cultivated human pig chimeras, the medical community is excited about using them to cultivate human organs, but no research team has further promoted this achievement. Although scientists can't get organs directly from pigs or sheep and transplant them into the human body, they believe that human stem cells may be one way to solve this problem. Pablo Ross, a zoologist at the University of California at Davis, participated in the human-chicken mosaic study, which he insisted was one of the most promising medical explorations. Human sheep mosaic process diagram from "Technology Daily" It is well known that the problem of transplant organ rejection has not been solved so far. Organ transplanters need to take anti-rejection drugs for a long time to reduce the immune system's attack on transplanted organs. Surprisingly, organs obtained from human-animal chimeras carry their own specific immune antigens, which can greatly reduce this rejection. According to reports, the project offers the possibility of treating other diseases such as type 1 diabetes. "We used animal chimera to successfully develop a mature mouse pancreas in rats and transplant the pancreas into mice with type 1 diabetes. After transplantation, the blood glucose regulation of mice tends to be normal. Hiro Nakuachi, the project's head of genetics at Stanford University, reported at the annual meeting of the American Association for the Advancement of Science last month. Ethical controversy worried that human cells enter the brain of experimental animals Interestingly, more than a year ago, the US government said it would provide funding for such controversial experiments, but then withdrew funds after receiving more than 20,000 complaints from animal rights groups. The controversy includes fears that there will be a weird image of the “human head†or “goat face†in the traditional impression. In the face of controversy, Dr. Zhong Nai said in the report: "The embryos we created in the experiment were destroyed after 28 days." In fact, in recent years, stem cells and genetic engineering have paved the way for the generation of chimeras between different species, and scientists hope to breed larger chimeric animals, such as pigs or sheep with human organs. However, this faces serious technical obstacles and complex ethical issues. Dr. Li Lingheng, a researcher at the Stowes Medical Institute in the United States, told the Science and Technology Daily that people don't want human germ cells and nerve cells, especially the chimera's brain, to be derived from humans. Therefore, germ cells and nerve cells. It is the ethical boundary of human-animal chimerism. Pablo Ross admits that he has similar concerns. At present, human cells account for less than 1% of chimeras. If the ultimate goal is to meet the needs of human organ transplantation, it is necessary to gradually increase the proportion of human cells in the chimera, and this process will inevitably lead to more Many ethical issues. Ross said that everything depends on how much human cells can behave in animals. If they spread farther than expected, such as entering the brains of experimental animals, it is impossible to approve such trials for ethical reasons. "If these cells are not only embedded in the intended organs during development, but participate in the development of other organs, such as the nervous system or the reproductive system, this will bring very complicated ethical issues. This is the main reason why everyone is worried about such research." Liu Zhonghua also believes. Therefore, Liu Zhonghua emphasized that how to effectively control these cells and not develop in the direction of organs that people do not want it to go is one of the focuses that researchers need to think and study. According to the situation of Liu Zhonghua, there is currently no management policy in China for the development of human and animal chimeric embryos. “However, the research institutes have ethics committees. Before conducting research on the chimeric development of human and animal embryos, they need to be reported to the ethics committee for filing and approval. Only after review by the ethics committee can the relevant work be carried out. Therefore, although it has not yet reached the policy level in China, it is very strict in the management of the system." Liu Zhonghua said. The long-distance technology can really be used in practical applications. At the annual meeting of the American Association for the Advancement of Science, Dr. Nakai said: "It may take another 5-10 years to apply this technology to humans, but we will definitely wait until the day when technology matures." As the first person in China to use the adult somatic cell as a nuclear donor, Liu Zhonghua admits that from a practical point of view, this technical route is widely recognized by the academic community, but in practice, human The proportion of cells in animal embryos is not very high, and there is still a long way to go from actual applications. Liu Zhonghua said that the current work faces many difficulties in research. The first is how to increase the proportion of human cells in the embryonic development of animals and control their whereabouts. "Because the ultimate goal of the research is to cultivate human organs in animals, or organs that are mainly human cells, the proportion of human cells in this organ is a very critical parameter. As can be seen from the report, this ratio is not high." Liu Zhonghua said. Dr. Zhong Nai's research team introduced human stem cells into sheep embryos to form a mosaic of the two. In the human-羊 hybrid animals obtained in this experiment, human cells contribute very little, and almost 99% of the genes are derived from sheep embryos, of which human cells are only about 10,000 (or less). Liu Zhonghua said that the human and sheep chimeras first cultivated by scientists at Stanford University in the United States have been a big breakthrough compared to previous studies, but it can be seen from the results that the work has a long way to go from practical applications. Going. Liu Zhonghua believes that the second difficulty of this research work is to control the direction of cells. The current design idea is to knock out the key genes in the original animal embryo that control the development of an organ, so that the animal itself has no way to develop this. organ. "For example, in the pancreas, if the sheep or pig-related genes are knocked out, the pancreas cannot be developed from animal embryos, that is, sheep or pigs' own embryonic cells. This is equivalent to the vacancy in this piece. This vacancy is designed according to theory. It will be filled by the human embryonic stem cells that have been moved in, so that a pancreas developed by human cells can grow." Liu Zhonghua said. The difficulty of technology breakthrough is still inseparable from the discussion of ethical issues. Liu Zhonghua believes that, first of all, how to improve the proportion of human cells participating in the development of this chimeric embryo through the exploration of technology and theory; secondly, how to effectively control The cell develops in the direction of the organ that one wishes to develop, and does not participate in those organs that people do not wish to develop. These are the problems that need to be solved urgently. "Of course, the goal of producing human organ transplant donor organs is not limited to these two problems. With the progress of related work, we will encounter other unforeseen problems," Liu Zhonghua said. (Technology Daily) Alopecia is the phenomenon of hair falling out of the scalp. The hair that normally falls out is the hair in the degenerative and telogen phases, because the hair entering the degenerative phase and the newly entering the growing phase are constantly in a dynamic balance. Insen supply Hair Care and Hair Growth raw materials including Minoxidil, RU 85541, Dutasteride, Finasteride, CB-03-01, Setipiprant, etc. Dutasteride Raw Material,Dutasteride Powder,Dutasteride Hair Loss,Hair Loss Dutasteride Hunan Insen Biotech Co., Ltd , https://www.insenhealth.com