DO STEM CELL CLINICAL PERSPECTIVE?

Many diseases are accompanied by cell death, the body can not naturally replaced. Sometimes cells die suddenly, such as myocardial infarction. In other cases, the process is slow and inevitable, such as Alzheimer's disease. Most clinical perspective stem cells (which are the equivalent of a reduction of energy for the body) - is that they can be made by specialized, ie, they will be replacing the body's cells that were lost due to disease.

However, quite a difficult obstacle to scientific point of view, ethics and even the intervention of politicians slowed progress in this field for more than ten years. However, over the past two years there has been a marked shift in the field through a series of remarkable discoveries: suddenly be possible to create cells that have the potential of embryonic stem cells without the use of embryos. This made it possible to eliminate most of the ethical issues related to research in the field of stem cells. Embryonic stem cells are characterized by two extraordinary properties that make them potentially useful for practical applications in medicine. First, they are "pluripotent", that is the ability to turn into any type of specialized cells of the body: myocardial cells, pumping blood, acid-cells of the gastric mucosa, the light-sensitive cells of the retina, or brain cells that retain information. Second, embryonic stem cells have the ability to continuously divide and create unlimited copies of their fellow cells - is the most important property, because to replace cells lost due to disease, there is a need for a huge number of new ones. The scientists also studied stem cells in adults. In such studies, no ethical issues arise, as in the case of embryonic stem cells, because they do not use human embryos. Bone marrow and organs such as the heart and liver, contain adult stem cells. These cells can differentiate into most cells of the body in which they are located. Adult stem cells are specialized cells replace the dead, since most specialized cells are incapable of natural reproduction. However, adult stem cells in most organs can not provide a complete replacement of the cells in the case of the massive damage in a number of diseases, although researchers are working to change this. Also of note is that adult stem cells are not pluripotent: Unlike embryonic stem cells, they are not able to grow into any cell of the body. The unique properties of embryonic stem cells is difficult to use for medical purposes. Ideally, patients who needed treatment for stem cells would have to get their own, genetically identical stem cells, because then they will not be attacked by the immune system of the patient, as foreign. However, embryonic stem cells, there are only a short period of time, namely during the first two weeks after conception. In addition, stem cells from embryos that are used for programs fertilization in vitro, to be genetically different from the patient's cells, which increases the risk of rejection of the immune system, and thus to suppress the immune response will require potentially toxic treatments. The use of embryonic stem cells is also fraught with ethical issues, as some people believe that an embryo can be implanted with the potential to make it developed into a fetus has the moral status of the person and therefore it can not be destroyed, no matter how great a benefit it could someone would bring. In 2001, President Bush limited federal funding for the then existing embryonic stem cell lines, that is, government money is not allowed to spend on studies, which implied the destruction of embryos. However, the newly-elected U.S. President Obama said that he will change the policy of the Government in the field of research. A possible solution to overcome such difficult obstacles, is the proposal of the Japanese researchers. They asked a simple, albeit non-standard question: can I get a specialized cell back to an embryonic stem cell, or even in cells with the exceptional properties that have embryonic stem cells? In each cell there are genes predetermine the structure and functions of each particular cell. Although all human specialized cells, like embryonic stem cells, have the exact same set of genes in each cell type "on" different genes. In other words, embryonic stem cells are transformed into specialized cells because certain genes are "switched on", while others "turned off." In 2006, a team of researchers at Kyoto University led by Shinya Yamanaka, used a powerful and relatively new technology to determine which genes are "on" and which are "off" in a specific cell type. Using this technology for research on embryonic stem cells and specialized cells, Yamanaka's team identified a number of genes in mice, which were always "on" in embryonic stem cells, but not in specialized cells. Then in late 2007, a group Yamanaka with a group of American scientists led by James Thomson of the University of Wisconsin and George Daley of Harvard, testified that the "inclusion" of four genes in human skin cells resulted in reversion of these cells into cells resembling embryonic stem cells. They called these new cells induced pluripotent stem cells (iPS). Like embryonic stem cells, iPS cells had the ability to transform into any type of specialized cells, as well as self-reproduction to an infinite number of copies. Thus, has become theoretically possible for anyone to create their own stem cells that are genetically identical and have all the potential to own long-lost human embryonic stem cells. In addition, the adult cells to be transformed into iPS cells can be easily obtained by biopsy of the skin or other surface tissues. And, very importantly, iPS cells can be generated by avoiding the creation and destruction of embryos, which allows you to bypass the moral barriers to the use of embryonic stem cells. However, it should be noted that, despite the importance of such a breakthrough in this area, therapy using iPS cells is still not a prospect near future. Still need to find answers to important questions and develop new technologies. The ability of cells to turn into any type of cell in the laboratory does not guarantee that using such cells can be successfully treated animal or human disease in the experiment. However, Rudolf Jaenisch testified that because iPS quite successfully treated sickle cell anemia in mice and Parkinson's disease in rats. However, the treatment is effective in rodents, do not always work in humans, however, they are often still active. It should also be noted that two of the four genes that were originally used to create iPS cells, are oncogenes that could turn iPS cells into malignant cells. In addition, for the transfer of the four genes in specialized cells used a retrovirus, which also carries a risk of becoming iPS cells into malignant cells. However, in late 2008, scientists reported that iPS cells can be created without the use of both oncogenes and retroviruses. In 2009, many laboratories are working on the modification of existing technologies to create iPS cells to make them as safe and effective. Another potential problem: how iPS cells created in the laboratory, safely move into the affected organ located inside the body? And if we can move them back if they can harmoniously "worked" with the healthy cells of the body? These questions are important and they do not have an answer. One of the facts that scientists have learned through the use of bone marrow transplantation (a type of stem cell therapy, is widely used for 30 years), is that the cells injected into the bloodstream, find their way to the appropriate place in the body and, once there, can respond to the body's own cells that surround them, starting to work in harmony with them. However, for certain organs is not so simple. For example, the heart. Suppose that due to myocardial infarction millions died of myocardial cells. After that, the patient's bloodstream introduced millions created iPS cells. Will they find a way to your heart? And even if found, it will take a correct position, and whether in the long term decline in unison with the unaffected healthy cardiomyocytes? If not, whether this will lead to arrhythmia? If these cells, in addition to heart, get into another body, it will not cause harm? The only way to find the answer to these questions - is the way of trial and error, first in animals and then in humans. In addition to treatment, iPS cells can also help to find the cause. Several research groups from Harvard created iPS cells based on the tissues of patients with different genetic diseases, including Parkinson's disease, Huntington's disease and type 1 diabetes. Because iPS cells can reproduce indefinitely, it allows you to create and study cells with genetic defects that determine the disease. The researchers also asked the question, whether there will be an opportunity to transform one type of specialized adult cells into iPS cells without creating another. This is considered unlikely until August 2008, when a team of scientists from the Harvard-led Douglas Melton transformed pancreatic cells not producing insulin, insulin-producing cells in live mice, which allowed to treat diabetes in this mouse. According to the materials of foreign publications prepared Volodymyr Pavlyuk

Japanese are replaced with artificial grafts immunity

Scientists from Japan spoke about the fact that they are trying to replace part of the immune system of artificial grafts. Studies have been completed successfully. The results showed that all the Japanese doctors who want to have a high-tech spleen and lymph nodes, they can provide. In experiments with mice, biologists from Kyoto University have shown that artificial lymph nodes are not worse than this, actually. To create a lymph node scientists used matrix (sponge) of the polymer and bone marrow stem cells. Previously they have made stem cells a few genetic modifications. Experimental lymph node biologists transplanted in mice, the renal capsule. Three weeks polymeric sponge producing cells, and the structure of the site has evolved and acquired features of the structure, typical for a healthy lymph node. Scientists have shown that artificial lymph nodes even participate in the immune response, forming B cells, T cells and memory cells. The spleen is removed from the body the bacteria and foreign particles, and in contact with the blood of foreign antigens allows the immune response - producing cells. According to Japanese researchers, artificial lymph nodes prove useful for patients with cancer, aging and just people who have to be naturally reduced immunity. Scientists say that in recent years gathered enough scientific data needed to finally create an artificial lymphoid tissues and organs that are suitable for clinical practice

Male baldness: the process - reversible

Knowledge - force. American scientists finally get to the real reasons men untimely loss of their hair. Hopefully, this knowledge will make morally stronger than those who have not yet learned to put up with his thinning hair past zero. Male baldness: the process - is reversible. Bald? Do not believe your eyes! In fact, the concept of baldness is largely arbitrary. Yes, the hair falls out, but in their place, as judged by the presence of roots, always appear new. True, the quality of the "new hair" is largely inferior to "gone" - weak, lifeless and ... are so small that they can be seen only under a microscope. The reason for that - a defect of stem cells, significant problems with their activation. New knowledge opens up space for the imagination of scientists. If you invent a nearly magic cream and use it to transform stem cells, normal hair color vzrastut like to order. Hair from the "function" of migration You say, it sounds fable? Perhaps if we take into account the fact that for years the same scientists previously associated with hair loss male hormone testosterone. With hefty medical Talmud and the world stands scale medsobrany broadcast: baldness is inherited, it is triggered by exposure to radiation and medication. And, as a sentence: a universal means to cure or prevent hair loss not. It seemed that the guy does not want to put up with a bald head, one way: to move hair from behind - the "front" of the head. Almost panacea Hair loss can be avoided! At least we should try to lower the level of stress a few utterly life, if possible, to say "no" to the physical and emotional stress. For the sake of lush mane is to offer sacrifice - to give up smoking and alcohol. With caution and only after consultation with a doctor to take antibiotics. Remove from her wardrobe hairpieces, wigs, hats close - they impede blood flow, are the cause of hair loss. Cost control your weight - fat accumulation of little help, but in the blood cholesterol levels, which may, on occasion, clog the sebaceous and sweat glands. The victims will certainly be justified if the gray hair to be able to keep and own peace of mind, and the hair. Let them "joy - twisted, grief whipped." The main thing that they - are.

Blood types arose for protection against viruses

As scientists from University of Bath believe, the person could get the enzymes defining a blood type, at bacteria – they were necessary to interfere with distribution of viruses to populations. Erythrocytes in blood of the person are covered with carbohydrate structures which call gliko-anti-genes. The phenotype of these anti-genes determines a blood type by AB0 system. A-positive people have the antibodies resisting to gliko-anti-genes of group B, B-positive have anti-And and anti-0, 0-positive – anti-A and anti-B. These antibodies don't exist at the beginning of organism formation, and appear with intestinal bacteria which make eritrotsitarny anti-genes. Viruses in a cover bear part of a membrane of a cage owner which contains anti-genes of blood types. As a result, if the virus arrives from an A-positive organism in B-or 0-positive, the immune system kills him etc.

Gliko-antigena consist of groups of enzymes – гликозилтрансфераз. Scientists investigated three-dimensional structure of a molecule гликозилтрансферазы from an intestinal bacterium of Bacteroides ovatus. It appeared that it has the structure similar with maternal, though possesses functional differences (its working capacity doesn't depend on ions). They show that maternal enzyme could occur from bacterial as a result of a horizontal transfer of genes (passing a specific barrier), instead of by vertical (from generation to generation). It is supposed that genes of bacterial enzyme were introduced in an organism of the ancestor of modern vertebrata, and from them there was an enzyme of the person as a security measure from viruses. Article with this conclusion is published by scientists in the Scientific Reports magazine.

Scientists learned not to start up HIV in immune system

tratScientists from Barcelona defined the mechanism of peneion of HIV in immune system. Besides, they managed to block this "entrance" and to prevent virus distribution, writes La Vanguardia. Today while it is difficult to imagine opening potential, but it is possible to hope that in 10 years the medicine blocking transfer to HIV in a human body will be developed, notes the edition. Earlier it was found out that HIV is capable to hide in the cages dendrites protecting immune system, and through them to infect lymphatic fabric. Now Barcelonian scientists described a molecule of dendrites which serves as "entrance" in a cage.

Opening in the future can lead to development of a preparation for HIV treatment at early stages or even protection from it. According to scientists, theoretically this mechanism is useful and for prevention of transfer of other viruses — for example, htlv-1, the causative agent of leukemia.

Stem cells used for a medicine assessment

Researchers from Jones Hopkins's University reported about concrete steps on a way of use of stem cells for studying of action of drugs on cells of a sick organism, reports Science Daily. The work described in the last number Nature Biotechnology, began a few years ago with studying of possibility of testing of experimental preparations on the specialized sick cells which have been grown up from induced plyuripotentny stem cells (iPSCs). Gabsan Li (Gabsang Lee) with colleagues then was withdrawn by skin cells from the person with an infrequent genetic disease, Riley-Day's syndrome. The choice of this disease was bound to that it affects only one type of nervous cells, to allocate which a traditional biopsy it is almost impossible. In experiments on verification of the concept scientists by means of known biochemical factors (they are called as Yamanaka's factors) reprogrammed skin cells in the induced plyuripotentny stem cells, capable to turn into cells of different specialization, and received from them nervous cells. "We can't study nervous cells directly, but this approach allowed us to see for the first time what exactly occurs at disease development", - Whether speaks. One of symptoms of a syndrome of Riley-Day - the lowered painful sensitivity, till 30 years lives only a half of patients.

Whether in recent research with colleagues from Memorial hospital Sloan Kettering used the same laboratorno grown-up nervous cells of a syndrome of Riley-Day for screening of seven thousand preparations. By means of the robot programmed on the analysis of their effect, scientists managed to identify quickly eight bonds for the subsequent testing, and only one - SKF-86466 - showed undoubted ability to stop or turn a course of a disease at cellular level. As Gabsan Li explained, clinical tests of SKF-86466 are impossible because of small number of patients with Riley-Day's syndrome in the world, but instead of this bond it is possible to use very similar preparation allowed for use on other indications.

Nanoconveyors of drugs in cancer cells are created in Russia

The molecule, capable to deliver drugs in the core of a cell, including affected by cancer process, is developed in Russia, is spoken in the report of the director of Institute of biology of a gene of the Russian Academy of Sciences of academician George Georgiyev and the head of the laboratory of molecular genetics of intracellular transport Alexander Sobolev. Such "supplier" does treatment at least one thousand times more effective in comparison with usual therapy, transfers ITAR-TASS. "As a serious call for those who frames specific and effective remedies of treatment, the paradoxical situation serves. It is at the same time necessary to use so-called superficial molecular markers to provide cellular specificity of medicine whereas achievement of maximum efficiency demands medicine delivery in a cell, in its certain part", - Alexander Sobolev told. For anticancerogenic agents such delivery has to be carried out usually immediately in a core, the scientist specified. But for this purpose it is necessary to frame a certain transport of medicine in the right place, uniting to two inconsistent demand. "We developed the modular nanoconveyors (MNT), allowing to achieve it", - Sobolev noted.

For this purpose from different natural molecules separate modules were taken and bridged in himerny, speaking to words of scientists, artificial protein about 10 nanometers in size. It also is MNT, and all modules keep the functions in its structure. MNT after intravenous administration collect mainly in tumoral cells, and in them – mainly in cores. Besides, these conveyors are a little toxic and almost immunogens. Thanks to it drugs for photodynamic therapy of a cancer – so-called photosensitinogens (FS), – delivered by the nanoconveyor in cancer cells, appear by 1000-3000 times more effective in comparison with free FS. So, for example, therapy of the epidermoid carcinoma of the person inoculated to mice with application of MNT causes an appreciable growth inhibition of a tumor and provides survival of 75% of mice with tumors while usual, free FS yields result only in 20%. Similar results were received and when using other antitumoral preparations. "High efficiency of therapy with application of various MNT allows to raise a question of possibility of application of conveyors of this sort for treatment of malignant neoplasms in clinic", - researchers emphasized. Now preclinical tests of MNT come to the end.