What Are Stem Cells? Adult, Fetal & Cord Blood Stem Cells
What are Stem Cells?
Learn about the different types and what they do and why they are important.
What are they?
Stem cells are cells of the body that have the ability to differentiate into other cell/tissue types. These unspecialized or un-programmed cells have the possible to change into muscle, cartilage, bone or other specialized cell types. Any body part that regenerates or “repairs itself” has cells kind stem. These cells act as backup, ready to replace other cells that get damaged. There is no current evidence that back-up these cells exist for vital tissues and organs such as: nerves, spinal cord, brain, heart, kidneys and pancreas. The development of new supplies of stem kind cells for these tissues is currently in the research phase.
Within the new field of science called regenerative medicine, there are four types of stem kind cells used for treatments, research and development:
* cord blood
Embryonic S.cells are extracted from a human egg that has been fertilized by a sperm. These cells are pluripotent; this method that they can transform into any cell kind found in the body with no restrictions or limitations. Embryonic S. cells can easily be matured into any functional adult cells such as muscle, organ, nerve, and brain. Embryonic cells have the possible to treat diseases such as Parkinson’s, Alzheimer’s, Diabetes, Cancer and more.
There are two main problems with using embryonic cells for treatment purposes:
1. There is an ethical and moral argue regarding the use of a fertilized human egg for treatment and research purposes.
2. There is a possible for tissue rejection (similar to the rejection in a heart, liver or blood transplant). This can limit the healing usefulness of embryonic cells.
Due to these issues many stem cell research organizations are working on developing S. cells from unfertilized eggs.
Fetal S. cells are extracted from the developing tissues and organs of an aborted fetus. A fetus contains a comparatively large supply of cells which are needed for growth and maturation. Fetal cells are believed to be more versatile than adult cells and less versatile than embryonic cells. The S. cells in a fetus are semi-mature cells.
Similar to embryonic cells, there are a few issues with using fetal S. cells for treatment purposes:
1. There is an ethical and moral argue regarding the use of fetal tissue for treatment and research purposes.
2. The number of S. cells in the fetal tissues may not be sufficient for the medical treatment of adults
3. There is a risk of tissue rejection (similar to the rejection in a heart, liver or blood transplant).
Cord blood S. cells are extracted from the umbilical cord, they are the earliest cells found in the fetus. Cord blood cells are hematopoietic; this method that they can only transform into different types of blood cells. Similar to bone marrow cells, cord blood cells can be used to treat a number of blood related diseases and cancers.
In using a patient’s own S. cells the risk of rejection is minimal and the time of action is non-invasive as opposed to the extraction of bone marrow. The complete extent of the therapeutic benefits from cord blood S. cells has not however been realized.
Adult cells are the back-up supply of cells extracted from adult tissue and organs that “auto- repair” when damaged. For example there are reparative cells in the skin and liver from which skin cells and liver cells can be extracted. Adult cells are multipotent, meaning that they are semi-programmed. For example, a skin stem cell cannot be transformed into a heart muscle cell. Adult skin S. cells can only become cells of the skin.
Stem cell progress
In Barcelona on June 2008, doctors implanted a newly constructed windpipe into a 30 year old patient. The windpipe was slightly constructed with tissue grown from the patient’s own adult cells. This is one of the first transplants in which the doctors produced a functional, biological structure that can’t be rejected. This advancement eliminates the need for anti-rejection drugs, which can often be accompanied by side effects such as high blood pressure, cancer and kidney failure. Details of the Clinical transplantation of a tissue-engineered airway can be found online in The Lancet medical journal.
Recently, there have been discoveries suggesting that cord blood S. cells and other adult cells, under the right circumstances, may be conditioned to transform into organ cells. On Feb. 11, 2008, in an early online edition of the research journal Proceedings of the National Academy of the Sciences, UCLA researchers published their progress regarding genetic alteration of human skin cells to create cells that are nearly identical to human embryonic cells.
Cord blood S. cells have been used to treat a variety of different diseases. A list of shared treatments is obtainable at http://www.mazecordblood.com/cordblood-transplant.htm In addition, a number of researchers are working on a variety of exciting treatments using cord blood. These include treatments for diabetes and cerebral palsy.
These examples of stem cell treatment illustrate the healing possible of stem cell research.