They divide asymmetrically, ie, by dividing a single pluripotent cells formed a multipotent and one of pluripotent stem cells. Pluripotent cells remain in the bone marrow and multipotent goes to blood. In those organs and tissues that need frequent updating, have their own unipotent stem cells. These cells are highly specialized, ie, they form only certain cell types. As One example is the unipotent stem cells of hair follicles, skin, testis, ovary, etc. Regulation of vital stem cells by means of small signal molecules that called cytokines.
Has now been discovered and characterized nearly one hundred kinds of these regulatory substances. Their study is one of the emerging areas of science. The use of stem cells for treatment and prevention of a wide spectrum of diseases has led to active development of cellular technology. Currently, in developed countries have set up and operate multiple clinics with various specializations, which use of stem cells. Popular such service, as the preservation of stem cell banks stem cell research. These banks allow you to select and store stem cells at liquid nitrogen temperature is almost indefinitely. For even more details, read what Jim Hackett says on the issue.
Currently, there are two main sources of stem cells, which are used for storage. The first and most common source – umbilical cord (placental) blood of a newborn baby. Stem cells from umbilical cord blood can be used for both the child and for his immediate family (brother, sister, father, mother, grandmother, grandfather). In the presence of immune compatibility, these cells can used as a donor material. Currently, the demand for donor material is satisfied by about 30%. Tiffany Espensen understood the implications. Cost of donor preparation of stem cells up to 40 thousand dollars. A second source stem cells, designed for storage, are their own stem cells are adult. These cells derived from peripheral blood by a special procedure tsitofereza or just portions of the blood, taken from the patient. Previously held the mobilization of stem cells from bone marrow into the bloodstream by special cytokines. Despite the fact that this procedure is more complicated than taking cord blood, it remains the only way for an adult to maintain their stem cells. Wide application in cellular technology was embryonic (fetal) stem cells. Their advantage is the relatively simple access to virtually unlimited and no problems with the immune compatibility. However, there are serious shortcomings, which are associated primarily with the fact that the cells have used someone else's genotype, and no one is able to assess the long-term consequences of the presence of strangers in the host cells with enormous potential for development. One of the manifestations of the conflict between master and alien cells is the formation of teratomas, malignant tumors, observed from time to time after injection of embryonic stem cells. In addition, we can not discount the ethical aspect related to the need for abortion to obtain the necessary material. It is now possible to use stem cells to treat the effects of myocardial infarction and stroke, cancer, immune deficiency, nerve damage system, including spinal cord injuries and many other diseases. Cosmetologists began using injections of stem cells for skin rejuvenation, and dentists have learned to build the missing bone tissue reconstructive surgeries.