More than 20 years ago, scientists discovered how to derive stem cells from mouse embryos (NIH 2005), but more recently the potential for using human stem cells has been realized. The use of stem cells in medical research hinges on the fact that stem cells have the potential to differentiate into any of the cell types within the body in response to chemical signals. Theoretically they are able to divide limitlessly until they do become differentiated. Extensive research is being carried out in various parts of the world to determine the specific combination of chemical signals that will induce stem cells to differentiate into brain and nerve tissue as well as an array of organ tissue, including heart, pancreas, and liver.
Stem cells are a potential source of an unlimited supply of replacement cells and tissues which can be used in treatments and cures for human diseases, as well as to explore the causes of diseases. For example, stem cells could be induced to differentiate into insulin-producing pancreatic cells which could be used to treat diabetes. This year, a team of researchers at Johns Hopkins University derived embryonic stem cells from mouse embryos, and transplanted these into paralyzed rats (JHMI, June 20, 2006). With the application of a surprisingly small number of cells, the paralysis was entirely cured, and the rats were able to walk again. It goes without saying that regenerating nerve tissue is a remarkable achievement. This research has the potential to be developed into treatments which could substantially increase the quality of life for millions of people suffering from a diverse range of illnesses. According to Douglas Kerr, the neurologist who led the research team, treatments based on this research could one day repair the damage done by Amyotrophic lateral sclerosis (Lou Gehrig's disease), multiple sclerosis, or traumatic spinal injury. With small adjustments, this approach could effectively treat Parkinson's disease and Huntington's disease.
The human embryos used in the first successful attempts to isolate stem cells for laboratory use were derived from unneeded in vitro fertilization procedures (NIH 2005), and were used with the informed consent of the donor. However, as stem cell research has become more popular and the potential for it has been more fully realized, the need for consistent sources of cells has become more apparent, and this need has become a hotly-debated source of contention. In the United States, for example, there has been considerable debate over the past five years as to whether the government should fund research using frozen human embryos which are stored by in vitro fertilization clinics. Embryos used in such research would be approximately five days old (Associated Press, 2006) and would be destroyed in the research process.
Opposition to the use of Human Embryonic Stem Cells on Religious Grounds
Opposition of the use of human embryonic stem ce