Stem cell facts
What are stem cells?
They are progenitor, or “originator” cells. In embryonic development, the earliest cells have the potential to develop into unique cells with distinct functions later. These early cells are called stem cells and they can replicate themselves. As they develop, they become muscle cells, nerve cells, etc.
How do they develop?
Cells transmit and receive information through receptors found on their surfaces. Although it is incompletely understood, environmental and genetic signals send messages to these cells to help them develop specific characteristics of specialized cells. Once the cells become specialized, they can no longer change their function. However, they can reproduce to form new specialized cells. In animal models, as some cells die, others are formed to replace them. Stem cells in the human body serve to produce and regenerate new cells that are required for the maintenance of health.
Where are stem cells found?
Stem cells are readily available in the umbilical cord and placenta of newborns. They can also be found in certain tissues in adults, especially the bone marrow and fat tissue.
How are they used?
Stem cells have been used in research as well as in treatment. The cells are collected and stored under strict conditions. Permission to use stem cells in research is granted by the government. Research focuses on how to promote the development of stem cells into specialized cells in order for them to be used in various circumstances. As a result of such research, scientists have been able to use stem cells in the treatment of many illnesses, most notably cancer. This is most commonly seen in leukemias, when the afflicted patient requires stem cell transplants in order to replace the defective blood with healthy blood cells. Stem cells have also been used to create skin tissue, to be used as grafts in burn victims.
Why the controversy?
It is well-known that President Bush had opposed stem cell research, whereas President Obama has fully endorsed it. However, Mr. Obama has been unable to lift an injunction on the use of stem cells produced from embryonic lines. This is still a politically hot topic.
The fertilized egg is the ultimate stem cell, as it has the potential to become an entire human being. The early embryo is a mass of stem cells, therefore, it is a rich source for these cell lines. Consequently, to use these cells, the embryo must be destroyed. As such, anti-abortion activists strongly oppose the use of stem cells. The ethical rationale behind this stance are beyond the scope of this article, but the stem cell lines approved for use have come from IVF “leftovers”, eliminating this ethical dilemma.
What are potential problems of using stem cells?
Despite the many benefits of using stem cells, there are some real concerns relating to health. First of all, stem cells may be harvested from an individual, treated, then returned to the individual. This is called an autologous or autogenic transplant. If the cells come from another individual, it is called an allogenic transplant. Either way, there is always a possibility that the body may reject the transplant, or the transplant reject the body, more so in the allogenic transplant. Furthermore, stem cells like to aggregate and they can grow out of control, becoming cancerous. In some cases, the overproduction may cause obstructions. This is potentially dangerous in blood vessels.
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