The feeder cells excrete some form of growth factor or hormone that keeps the human cells healthy, raising the issue of possible contamination by animal viruses or other pathogens. The hearing also could give NIH a reason to quicken its pace on the issue, Chow said, especially if the committee discusses proposed privately funded stem cell research. Committee members should not look for hard and fast numbers or qualifications on the 64 lines during the hearing, she added, since a great deal of basic science remains before many of the colonies can be characterized. Other witnesses are expected to include Rep. Jim Langevin, D-R.I., who has been paralyzed from the chest down since a handgun accident at age 16. Langevin is expected to discuss the prospects stem cell research holds for treating conditions such as his.
Stem cells are the basis for all other cells in the human body.
Adult stem cells, which are rare, are taken from mature tissue but appear to be limited in their ability to produce cell types other than that of the tissue from which they were taken. Embryonic stem cells, however, seem to be able to create specialized cells throughout the body, such as heart or pancreatic cells. Researchers are more optimistic about the ability of embryonic cells to develop into medical treatments for disease, but the cells are created by destroying human embryos. Bush's decision prevents federal funds from going to procedures that destroy any more embryos. Copyright 2001 by United Press International.