Embryonic Stem Cells
Stem cells have potential in many different areas of health and medical research. To start with, studying stem cells will help us to understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are due to problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.
Another potential application of stem cells is making cells and tissues for medical therapies. Today, donated organs and tissues are often used to replace those that are diseased or destroyed. Unfortunately, the number of people suffering from these disorders far outstrips the number of organs available for transplantation.
Stem cells offer the possibility of a renewable source of replacement cells and tissues to treat myriad diseases, conditions, and disabilities including Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis and rheumatoid arthritis. There is almost no realm of medicine that might not be touched by this innovation.
The clinical potential of stem cells has also been demonstrated in the treatment of other human diseases that include diabetes and advanced kidney cancer. However, these newer applications have involved studies with a very limited number of patients, using stem cells that were harvested from people.
Pluripotent stem cells have been isolated from human embryos that are a few days old. Cells from these embryos can be used to create pluripotent stem cell "lines", cultures that can be grown indefinitely in the laboratory.
Once a stem cell line is established from a cell in the body, it is essentially immortal, no matter how it was derived. That is, it does not have to be created again from the original embryo or adult. Once established, it can be grown in the laboratory indefinitely and widely distributed to other researchers.
In addition, before scientists can use any type of stem cell for transplantation, they must overcome attempts by a patient's immune system to reject the transplant. Human stem cell lines might in the future be modified with gene therapy or other techniques to overcome this immune rejection. Scientists might also be able to replace damaged genes or add new genes to stem cells in order to give them new characteristics that can ultimately help to treat diseases.
The embryo must have been created for reproductive purposes but no longer be needed for the couple. Informed consent must have been obtained from the parent(s) for the donation of the embryo, and no financial inducements for donation are allowed.
Embryonic Stem Cells- Source and medical importance
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1st day- the fertilized oocyte contains 2 nuclei. | |
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2nd day- 4cell stage. |
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| Shortly before implantation the embryo forms this structure consisting of an outer layer of cells (that will become the placenta) and an “inner cell mass” which will form the embryo itself |  |
5th/6th day – The blastocyst stage. |
| The cells from the ICM are taken and are cultured under special conditions to have the ability to become different cell types. |  |
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Cell types that are able to be produced by embryonic stem cells- | |
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| Red blood cells Nerve cells Skeletal,muscle cells, Lung cells,Heart muscle, Pancreas |
