WASHINGTON Nov 20 Researchers announced on Tuesday that they had found a way to make powerful human embryonic stem cells without using cloning technology and without making a human embryo.
Here are some facts about stem cells:
* Stem cells are the body's master cells, the source of all cells and tissue such as brain, blood, heart, bones, muscles and skin.
* Embryonic stem cells come from days-old embryos and can produce virtually any other type of cell in the body. They are called pluripotent stem cells.
* The new cells are called induced pluripotent stem cells, or iPS cells for short. They appear to have all the qualities of embryonic stem cells, although this has not been fully tested.
* Pluripotent cells can also live for many years in lab dishes, making them useful for research and making it possible for scientists to share them.
* Adult stem cells are harbored in blood and mature tissue in the bodies of children and adults. They are more specialized than embryonic cells and give rise to specific cell types, although they may be coaxed into a broader range of cell types under the right conditions.
* Scientists hope to harness the transformational qualities of stem cells to treat a variety of diseases affecting millions of people worldwide, including brain cells for Parkinson's disease, pancreatic cells for diabetes and nerve cells for spinal-cord injuries.
* They also hope to use them to study specific diseases in people, for instance, by taking a cell from a patient with cancer and studying ways to treat that cell.
* The issue is controversial because some people believe the destruction of any embryo is wrong. Leaders of the Roman Catholic Church and some other religious and conservative political figures hold this view, although some opponents of abortion rights support human embryonic stem-cell research. (Reporting by Maggie Fox, editing by Will Dunham)
