Hematopoietic Stem Cells
Cells, which are able to have self-renewal and reproduce function to form different kinds of mature cells, can be defined as “stem cells”.
Stem cells sources can be divided into embryo stem cells and stem cells from mature tissues. Embryo stem cells are formed when the embryo is fertilized and had split into 8 cells after the 4th dividing, and are also called the totipotent stem cells. And also the pluripotent stem cells, which was generated from the 5-days fertilized embryo. Mature tissue stem cells will form organs after the human was born, such as the brain, pancreas or bone marrow stem cells. Under special condition it can differentiate into limited types of tissue. The cell with the weakest differentiation function is call multipotent stem cells.
During the embryo stage, human fetus’s blood producing organ is the yolk sac and the liver. After getting mature, hematopoietic stem cells can be found in the bone marrow and the umbilical cord. Hematopoietic stem cells can differentiated into red, white blood cells and hematoblasts, hence the transplant of HSC have great value in the medical field. Growing stages for stem cells：
In the different kinds of mature stem cells, hematopoietic stem cells (HSC) are found in the bone marrow, baby’s umbilical cord and in adult’s peripheral blood.
This is a group of blood tissue that has not been differentiated, it can produce blood and immune system cells such as oxygen rich blood cells, blood clotting hematoblasts, infection resistance white blood cells, lymphocyte which produces the antibody. Hematopoietic stem cells can be used to treat many kinds of diseases, tumor, unusual congenital metabolic or immune deficiency diseases. Furthermore, when clinical cancer treatments uses resistance medication or radiation therapy, it kills the cancerous cells, in the meantime it also kills healthy bone marrow stem cells. Doctors then can transplant stem cells on the patient, so it can produce new blood and immune system, which can prolong the patient’s life.
Update: Oct. 2009