What are stem cells?
Normally a skin cell remains as a skin cell all its life. A nerve cell remains as a nerve cell until it dies and so on. Stem cells, however, can change into many types of cells -- heart cells, nerve cells, muscle cells, skin etc. That is why they are called stem cells. They are the stem or trunk from which the branches (different cell types) can proceed.
In other word a stem cell is a cell that has the ability to continuously divide and differentiate (develop) into various other kind(s) of cells and tissues. Like a blank microchip that can ultimately be programmed to perform any one of a number of specialized tasks, stem cells are undifferentiated, 'blank' cells that do not yet have a specific physiological function. Because of this capacity they may prove useful for treatment of some medical conditions as they can be trained in different directions.
Where do stem cells come from?
Basically, there are two types of Stem Cells,
Embryonic stem cells: Embryonic stem cells are obtained by harvesting living embryos which are generally 5-7 days old. The removal of embryonic stem cells invariably results in the destruction of the embryo.
Adult stem cells: Stem cells can be taken from living humans (children or adults) without harming them. These are called adult stem cells.
Adult stem cells, despite their name, can be taken from children or adults, without harming them usually tissues from the bone marrow, liver, epidermis, retina, skeletal muscle, intestine, brain, dental pulp and elsewhere , or from umbilical cord blood after the birth of a child, or derived from Human Placenta, which up to ten times as many stem cells can be harvested from a placenta as from cord blood.
Why are adult stem cells preferable to embryonic stem cells?
Adult stem cells are a "natural" solution. They naturally exist in our bodies, and they provide a natural repair mechanism for many tissues of our bodies. They belong in the microenvironment of an adult body, while embryonic stem cells belong in the microenvironment of the early embryo, not in an adult body, where they tend to cause tumors and immune system reactions.
Most importantly, adult stem cells have already been successfully used in human therapies for many years. NO therapies in humans have ever been successfully carried out using embryonic stem cells. New therapies using adult type stem cells are being developed all the time. There are many examples of success stories using adult stem cells.
Is Stem Cell Research Ethical?
Most types of stem cell research are morally acceptable and laudable. Only research using embryonic stem cells raise insuperable moral objections. An ethical overview:
* Embryonic Stem Cells - always morally objectionable, because the human embryo must be destroyed in order to harvest its stem cells.
* Adult Stem Cells - morally acceptable and also since the afterbirth umbilical cord or placenta is no longer required after the delivery has been completed.
What are the benefits of stem cell treatment?
Stem cell research may benefit many conditions, including Alzheimer's disease, Parkinson's disease, diabetes, spinal cord injuries, heart disease and cancer. The new cells may be able to replace damaged tissue. But it must be remembered that such benefits may be a long way off as they are complex diseases and the cures are never simple. We need to be optimistic but also realistic, nevertheless there’re many success cases for treating these diseases.
