A stem cell is a body cell that has no function in the organism. For this reason, they have the ability to develop into a variety of cell types (eg nerve cells, heart cells, blood cells).
Stem cells are therefore pluripotent and therefore play a special role in regenerative medicine. It can also be said that it is a form of the cell of origin, because a stem cell can multiply indefinitely. In this cell form, a subdivision into embryonic and adult stem cells takes place.
As the name implies, embryonic stem cells occur only at the stage of development of an embryo. They are not yet specialized, which is why they are called totipotent. This means that a complete organism can develop from a cell.
In contrast, adult stem cells are cells that are found in the human body after birth. Compared with embryonic stem cells, they are only multipotent and form only certain types of cells. Among the adult stem cells include cells that are located in the human bone marrow and reproduce the vital blood cells here. Furthermore, stem cells could also be detected in the liver. They ensure that in case of damage an exchange of dead cells takes place.
The most well-known repair function involving cells is the healing of the skin after superficial abrasions. In principle, no complete organism can develop from adult stem cells. From stem cells, certain cell types can be bred in the laboratory with the help of nutrient solutions.
Stem cells have the ability to form so-called daughter cells. These too have the properties of a stem cell. This is made possible by the asymmetric cell division, which has not yet been completely clarified by science. The cells to which stem cells ultimately develop lie in the biological area in which they are found.
Especially in blood formation stem cells have an important meaning. From them arise in several steps red and white blood cells and platelets. They thus contribute to the renewal, repair and growth of the structures of the human body.
Use stem cells especially in the treatment of diseases. They ensure that an exchange or restoration of damaged or even lost tissue can take place. For more than 40 years, they have been used to cure certain diseases. The treatment with the help of stem cells helps to not only fight the symptoms of certain diseases, but that the damage in the body in the long term to undergo regeneration.
Embryonic stem cells may not be obtained or used by law in Germany, since embryos must be destroyed for this purpose. Stem cell research is only possible if very strict conditions are fulfilled. By means of certain interventions (eg bone marrow puncture with bone marrow donation) the adult stem cells can be won. For the patient, however, this process is painful and also involves risks.
There has also been the possibility for some years that stem cells are obtained directly after delivery from the blood of the umbilical cord. Since they are in their development between embryonic and adult stem cells, they bring with them some positive qualities. For the newborn, the removal is painless and without risks. The use of stem cells from umbilical cord blood is now increasing worldwide. Many parents want to freeze for their child or anonymous the stem cells from the umbilical cord blood.
Probably the most well-known disease of the so-called blood-forming stem cells is leukemia. The lifespan of blood cells is limited, which is why the body has to re-produce them over and over again. If there is a genetic change in the respective stem cells, more and more dysfunctional white blood cells enter the bloodstream, which displaces the normal components of the blood.
It then comes to a lack of red blood cells, which are responsible for the transport of oxygen. Anemia develops, which then leads to an oxygen deficiency in the organism. In leukemia too few haemostatic platelets are present. The tendency to bleed increases and there is a lack of functional white blood cells, the susceptibility to infections increases. Medicine differentiates between acute and chronic leukemia. Both types of this disease can not be prevented. In the treatment of leukemia, the adult blood-forming stem cells are used, even after chemotherapy or radiation, they contribute to the fact that the damaged bone marrow can regenerate.
In connection with the topic "stem cells" should also be called the stem cell law. It serves to protect unborn life. In it regulations are made, which circumstances make it possible in Germany, to research embryonic stem cells. For the production of embryonic stem cells, it is necessary to kill cloned or even by artificial insemination embryos.
The Embryo Protection Act prohibits this practice in Germany. Under certain circumstances, however, it is possible that embryonic stem cells from aborted fetuses may be imported for research purposes. The fulfillment of the requirements of the strict requirements of the Stem Cell Act are checked and evaluated by the "Central Ethics Committee". The Robert Koch Institute (short: RKI) is considered to be the competent licensing authority. Only with its consent can embryonic stem cells be imported from abroad.