| The simplest eyes and a small liver grown in the laboratory |
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Japanese scientists claim that they were able to use stem cells to grow a rudimentary human liver, blood vessels filled with working and having the ability to metabolize. At the same time, another group of scientists from Japan reported on the growing element of the eyeball from human stem cells.
Both achievements were presented at the annual meeting of the
International Society for Stem Cell Research, held in Yokohama, Japan.
Although before implantation man full grown in the laboratory of the eye
and liver still required a considerable amount of work and research,
and independent experts say that the results are a brilliant progress in
this area. In the meantime, authorities have grown more applications
in medicine.
Takanori Takebe biologist who studies stem cells at the University of Yokohama, Japan, and his colleagues have grown a little rudimentary liver, using only three out of stem cells. The trick in an instant to make a new ingredient into a mixture of cells. According to the scientist, to develop a method took more than a year and hundreds of attempts. To start investigators have placed genetically reprogrammed human skin cells called "excited pluripotent stem cells" in the growth plate in a specially designed chemical bath. Nine days later, the cells began to develop in the hepatocytes, or liver cells. At this point, the scientists added cells taken from the umbilical cord, which evolved into a network of blood vessels and bone marrow cells that can mutate into bone, cartilage or fat. Two days later, the composition of the cells organize themselves and formed a three-dimensional "embryo liver" - 5-mm slice of tissue, carrying out basic functions of the liver. After organ transplantation in the mouse, scientists said the tiny blood vessels of the liver to work properly, and she was able to successfully metabolize medications that human liver can process, and the rat, as a rule, no. According to a more developed version of Takebe liver can eventually be used for long-term organ transplant, as well as a short-transplant for patients whose own damaged liver can recover. However, until this moment have to do a lot of work, as the embryos of the liver are not the most important component - the bile ducts, but their cells do not produce enough plasma protein albumin in comparison with natural liver cells. Nevertheless, to achieve a group of scientists captured the imagination of many scientists around the world. At the same time, Yoshiki Szasz and his colleagues from the Center for developmental biologists in Kobe, Japan, reported that they were able to make human stem cells called "retinal progenitor cells" evolve into a major component of human eyeball, called the "optic cup". In a Petri dish, and cells were drawn arbitrarily shaped eye vesicles, which are themselves bent, creating a cavity of half a millimeter wide, lined with retinal cells - a glass eye. The most amazing thing, as explained by independent researchers, that this process is deployed in the right order without any external intervention on the part of researchers. In fact, scientists had not known how developing optic cup, while Szasz and his colleagues did not see the process in the laboratory. The researchers say that this achievement gives hope for the restoration of blind people. Ophthalmologist from the team of researchers Masao Takahashi has already begun transplanting retinal layers grown in the laboratory of the eye glasses of blind mice in the hope to restore their vision, and academic plans before the end of the year to the same experiment on monkeys. It remains an open question whether the transplanted tissue will unite with their families. Szasz argues that received eye glasses "clean", ie do not contain residues of stem cells that can cause a risk of growth of cancerous tumors or unwanted tissue. According to the scientist, there is no reason to expect growth of bone cells in that eye. Stem cells have been successfully used to create the existing human trachea, and bladder. In addition, stem cells have been grown animals several organs, including lungs and penis. |
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