Stem Cells: What are they and where do they come from.
During these days of advances in treating and curing many well known human diseases, stem cell research has begun to raise the human spirit by offering hope to those who think they don't have any.
The new research in human developmental biology has led to the discovery of human stem cells, including embryonic stem cells(ES), embryonic germ cells(EG), fetal stem cells and adult stem cells(Recer,1). Stem cells can be taken from bone marrow, from stem cells in the blood circulation, or from the blood in the umbilical cord of a new-born infant(Recer, 1-2). Stem cells can also be obtained from fetuses. The procedure for obtaining bone marrow is known as harvesting, it is a fairly simple procedure with very few if any risks to it at all. About one liter of marrow is collected from the bones of the pelvis by inserting a needle into them many times and drawing off the marrow.
The marrow can be frozen and stored for months or even years. This is often done for patients with chronic myeloid leukemia of those with lymphoma. The storing of this marrow may be a way to alleviate the pain if the leukemia should return. .
There are a small number of stem cells in the circulating blood off healthy .
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people. These are known as peripheral blood stem cells (PBSC)(Robeznieks 2). .
Normally there aren't enough of these in the blood stream to harvest from the blood. The use of peripheral blood stem cells can be seen when a patient's blood is passed through a machine and then returned to the donor. The machine can separate off the blood cell population which contains the stem cells. This process is called leukapheresis(Robeznieks 2).
Umbilical cord blood contains a high number of stem cells from the baby, which can be transplanted to adults and children to try and repopulate the implanted's bone marrow. For some patients it may be possible to use their own marrow or peripheral blood stem cells.
