Stem cells are one of the wonders of the universe. These cells are the building blocks of our bodies, and cannot only self-replicate almost infinitely, certain stem cells can also become or produce almost any cell type, depending on the circumstances and environment. Although there are risks and controversies, the medical benefits of stem cells are unparalleled by any other medical technology available today, and the field of research is one of the most promising of our time.
There are two classes of stem cells: embryonic and adult stem cells. An embryonic stem cell is a stem cell that is obtained from the human embryo, usually cloned and activated in a laboratory. They are capable of unprecedented reproduction, and can create all cells in the body. Adult stem cells are cells obtained from non-embryonic human sources, such as bone marrow. Unlike embryonic stem cells, adult stem cells can only self-renew in a limited manner.
There are three types of stem cells: totipotent, multipotent and pluripotent. Totipotent stem cells, which only occur as embryonic stem cells, are capable of unlimited self-renewal and the capacity to become any cell type in the body. Multipotent stem cells, which only occur as adult stem cells, can only self-renew in a limited manner, and only produces environment-specified cell lines. Pluripotent stem cells, which can occur as both cell classes, have a limited capacity for self-renewal, but the ability to produce a range of adult cell lines.
To date, stem cell therapy (the use of stem cells for medicine) is limited. Re-growth of bone marrow and blood cell production is the height of current technology. Research is currently being undertaken into the abilities of stem cells in healing the body; particularly to regenerate cells and lessen the effects of or cure medical diseases that, previously, left the patient crippled for life. Scientists are looking into the possibilities of treating injury, medical conditions and genetic diseases; including autism, cerebral palsy, heart diseases, crushed spinal cords and cancer.
Stem cells are also valuable in the development of new drugs. Due to ethical considerations, scientists cannot test new drugs on humans. Instead, scientists were using human cell cultures as their major testing base. Stem cells have the ability to replicate into any tissue type, making them more valuable in the testing of new drugs by allowing researchers to see a broader scope of potential drug effects.
There has been some controversy over the use of embryonic stem cells. Certain groups, including religious groups, suggest that the use of embryonic stem cells destroys potential human life – the “souls of the unborn”. In some countries, such as the United States of America, government support and funding for stem cell research have been removed because of pressure from these groups. Recently, some of these countries have been lifting these restrictions to allow more research as they begin to see the obvious...