Stem cells decrease in our body with age. In addition, they can be functionally different, so they are not a panacea for all diseases. However, stem cell therapy remains one of the most promising branches of medical science. ..
Stem Cells: Where From and Where?
The adult body, fortunately, has a reserve, which, if necessary, is mobilized - such cells move in the area of damage and repair the affected tissue sites. This, figuratively speaking, natural stem cell therapy - it occurs without human intervention. However, the possibilities of regenerating tissues and organs at their expense are not unlimited. And this tendency worsens with biological age.
Three sources of stem cells
To date, mankind has three main ways of obtaining stem cells.
|On the first one, we are already well aware: abortive material - the source of fetal stem cells , which have true totipotency.|
|The second method is almost perfect, but for the currently living there is no longer available - the cord blood stem cells .Now many( but not all and not everywhere) caring and far-sighted mothers can provide a guarantor for healing for their children by sending to the special bank a placental blood.|
|The third method - the isolation and reproduction of human own human stem cells( autologous stem cells ) - can give hope if not for complete healing, then to extend life to millions of patients of different ages.|
How much in our body does stem cell?
As a child, all the cells of our body were very promising, but over the years "decided", settled and began to perform strictly narrow, specialized functions. Nevertheless, each of us still has a stock of precious stem cells, which, alas, is scanty every year. With the course of inexorable time, there is a catastrophic decline in their number. Their ratio is changing rapidly, and not the best for the party: at birth, one stem cell is identified for 10 thousand;to 25 years - already 1 per 100 thousand;to 30 -1 per 300 thousand. .. Well, by the age of 60 they are nothing - 1 stem for 6 million mature cells. Therefore, banks of human stem cells are created. As a rule, these are separate units at transplantation centers. They are purified, tested and cultivated cultures of cell lines obtained on the basis of not only cord blood, but also autologous.
Stem cells are a living potential of
For the time being, pluripotent stem cells of several sources
are of the greatest interest for medicine. Hematopoietic stem cells. "Pioneers" in their field: the development of their research began in the 50's of last century. Already then it was noticed that in the blood there is a very rapid change of differentiated cells - during the process of hemopoiesis 1 billion red blood cells and 100 million leukocytes are produced hourly( and, consequently, destroyed).Such rates can be ensured only by the proliferation of a number of self-sustaining cells that have been considered as stem cells. True, such stem cells are also susceptible to disease, as an example - a disease of cells that are responsible for blood formation, called idiopathic myelofibrosis.
Nervous - their capabilities have been identified relatively recently, so it is too early to talk about practical application.
Hepatic - the so-called oval cells located in the bile ducts, are the precursors of hepatocytes and bile duct epithelium cells. This type of cells promises to deliver mankind first of all, from cirrhosis of different etiology.
Mesenchymal , the main source of which is bone tissue. However, for their extraction, it is more promising to use fat. Consequently, biowaste after operations on liposuction will still serve humanity well. Mesenchymal stem cells are able to differentiate into cells of various types of connective tissue of the body - adipocytes, chondrocytes, myoblasts and osteoblasts.
For the time being, the first in the list is leading as a therapeutic tool - they are the most studied. However, a great interest for scientists is mesenchymal. The fact is that mesenchymal stem cells possess a super-valuable dignity - low immunogenicity. In other words, the recipient's immunity will not meet the "newly arrived" stem cells with bayonets. If they get into the donor's body, they do not express a lot of antigens than sin cells of homeopoietic origin. Accordingly, the risk of undesirable side reactions in the case of their use is reduced. Consequently, this "repair" material has more chances for successful implementation - it will not be rejected by the recipient organism.