Introduction to Stem Cells
Stem cells are special undifferentiated cells that have the potential to develop into many different kinds of cells. They are the foundation for every cell, tissue and organ in our body. They help our bodies to replenish themselves by continually growing and dividing. Stem cells act as an internal repair system and in certain organs such as our digestive tract or bone marrow, they can fix and replace worn out tissue. As unspecialized cells, they are a blank slate, capable of transforming into muscle cells, blood cells, brain cells and more. Stem cells can also renew themselves by dividing and giving rise to more stem cells.
There are various kinds of stem cells such as embryonic, adult and umbilical. Embryonic stem cells are derived from the cell mass of a fertilized egg. Eggs can be from a variety of animal sources, including humans. Frozen human embryos that are created through in vitro fertilization procedures are contributed with the consent of the donor for this purpose. Adult stem cells can be found in limited quantities in certain tissues of the body that regularly create replacement cells for those that are lost through normal use, injury and disease. For example, stem cells can be found in the bone marrow, which creates all types of specialized blood cells. The umbilical cord of a newborn is also a source of stem cells (National Institutes of Health).
Stem Cell Treatments
As of 2009, there are several stem cell therapies that are currently in use. One of the most common and well-known is bone marrow transplant. This procedure is used to treat leukemia, blood-diseases and other types of cancer. It involves replacing diseased and abnormal bone marrow and subsequent stem cells, with that of a healthy matching donor. Successful transplants enable donated stem cells to migrate into the patient's bone marrow where they can begin producing healthy leukocytes (infection-fighting white blood cells) and replacing abnormal cells.
Another such procedure is the transplant of adult peripheral blood stem cells. Although most stem cells are present in bone marrow, limited quantities are available in the blood. These stem cells can be used just like bone marrow to treat the same diseases. The collection of peripheral blood stem cells is much easier and less invasive then collecting bone marrow. However, it is more challenging to collect enough stem cells in this fashion because they are less concentrated in the bloodstream than in bone marrow.
Umbilical cord stem cell transplants can also treat leukemia, blood-diseases and certain cancers. The umbilical cord, which is normally discarded after the birth of a baby, can now be used to harvest stem cells. The stem cells that come from the cord are less likely to be rejected than either bone marrow or peripheral blood stem cells (The University of Utah).
The Future of Stem Cells
The regenerative properties of stem cells offer potential therapies for a treating a variety of ailments and disease. There is still much research and investigation that needs to be done with stem cells. Currently, several therapeutic applications for stem cells are being tested. Some of these therapies are for the treatment of musculoskeletal abnormalities, cardiac disease, liver disease, metabolic disorders, auto-immune diseases and advanced cancers. However, only a very limited number of patients have had access to these new procedures (International Society for Stem Cell Research).
