Stem Cell Research Controversies

Stem cells are "blank" cells that have the potential to develop into any type of cell in the body -- nerve cells, heart cells, kidney cells. Scientists are trying to harvest the cells before they have differentiated, then coax them into becoming certain types. If they could grow cardiac cells, for instance, scientists one day might be able to replace damaged heart tissue in someone who has had a heart attack. By growing nerve cells they might be able to repair brain cells damaged by Alzheimer's or Parkinson's, or replace injured spinal cord cells in a paraplegic.

Stem cells have two important characteristics that distinguish them from other types of cells. First, they are unspecialized cells that renew themselves for long periods through cell division. The second is that under certain physiologic or experimental conditions, they can be induced to become cells with special functions, such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas. Scientists primarily work with two kinds of stem cells from animals and humans: embryonic stem cells and adult stem cells. There are many ways in which human stem cells can be used in basic research and in clinical research. Studies of human embryonic stem cells may yield information about the complex events that occur during human development. Stem cells can also be used to test new drugs. Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissue.

Since the onset of stem cell research has been established, many controversial issues have arisen. The debate over stem-cell research may be one of the most important in modern society. On the one side are those who believe that it holds out the promise to cure, or at least relieve, some of humanity's most terrible diseases. On the other side are those who insist that stem cells can only be collected by killing embryos -- by murder. Before 1998, research on stem cells-mostly from non-controversial sources such as bone marrow and umbilical cord blood-was framed in highly technical terms, focusing on the release of the latest scientific findings or emphasizing the details of funding and applications of research. These technical dimensions, while important, don't touch on political emotions or grab much attention. When the discovery of human embryonic stem cells was announced in 1998, research