How Stem Cells May Speed New Cures

With the first-ever human test of a medical treatment based on
embryonic stem cells gaining federal approval, researchers are
optimistic that President Obama will soon lift a controversial Bush
administration ban on federal funding for embryonic stem cell research
and speed work to develop treatments for diabetes, heart disease,
cancer, Parkinson's, and Alzheimer's. The newly approved human trial
involves an attempt to repair severed spinal cords in paraplegics. All
stem cells can replicate over and over, thanks to an enzyme that slows
their aging. This enzyme, telomerase, is what makes cancer cells
proliferate, too. Stem cells can also make new cells programmed to do
specific jobs. Bone marrow stem cells, for example, make red blood
cells, which carry oxygen through the body. In the past decade,
researchers have discovered different forms of stem cells, all of
which hold promise as tools for developing new treatments for some
chronic diseases. U.S. News's Megan Johnson lists 3 types of stem
cells (and their pluses and minuses in medical applications), and
Nancy Shute offers 3 ways that stem cells may speed new cures.