Stem cells are early cells found in animals and humans which have no specialized function. These unspecialized cells may may have the potential to become one of many types of cells found in the human body (e.g. blood cells, heart cells, etc). These are very young cells are found both early embryos and some adult tissues.
What are embryonic and adult stem cells?
Human stem cells can be extracted from 3-7 day human embryos — such as the donated frozen embryos stored in-vitro fertilization clinics. The embryonic stem cells from these embryos may have the potential to develop into many of the cell types in the body.
Stem cells can also be extracted from adult tissue. There has been a consensus among researchers that adult stem cells may limited in usefulness due to the small numbers of cells found in adult tissue and their limited ability to mature into a limited group of human cell types.
What are stem cell lines?
Researchers have found that some stem cells can be adapted to grow in the laboratory. Citing ethical concerns about embryos being destroyed to obtain stem cells for research, in 2001, the President banned the use of federal funds for research on any stem cells taken from new embryos. Only those stem cell lines already in existence could be used in federally funded research.
Has a human embryo been cloned for the purpose of isolating stem cells?
In February 2004, researchers at the Seoul National University in Seoul, South Korea announced that the successful cloning of 30 human embryos using nuclear transplantation technology. Sixteen Korean woman donated 242 eggs to create the embryos. The embryos were cultured and stem cells were harvested from them.
What is the promise of stem cell research?
Human stem cells respresent an important tool for clinical and basic researchers interested in understanding the complex events involved in human development. Mistakes which occur in these processes often lead to serious medical condition such as heart disease, diabetes and certain types of cancer.
Researchers also believe that stem cell reserch may lead to a renewable source of human replacement cells. Researchers regard stem cells as an important opportunity to treat human disease. Over 100 million Americans suffer from diseases that may eventually be treated more effectively with stem cells. These include Parkison’s disease, Alzeheimer’s disease, diabetes, and certain types of cancer. The timeline of these treatments is yet undetermined.