Don't let anyone see you reading this. It's a topic hotter than an autoclave: stem cells. Two institutions we approached, a prominent cardiac research center and a well-known medical school, declined interviews on the topic because it's so controversial. But they hastened to say they are not investigating embryonic stem cells (ESC), only adult stem cells.

As a refresher, stem cells are basic human cells that can grow into a variety of tissue. This gives them the potential to replace damaged heart muscles, lung tissue, bone, and the biggie: heal damaged nerve tissue. ESC research got off to a bad start because embryos are the source of the cells. A researcher had to fertilize human eggs with sperm and harvest the cells after four to seven days, thereby killing what could have been viable embryos, and igniting the controversy. ESC advocates callously asked: “Where's the problem? Most cities have abortion clinics and they trash fetuses every day. ”

To make matters worse, a few news stories reported early success with ESC on a few diseases. Most were premature. For instance, a young South Korean woman who had been lame from birth was treated with ESCs and later photographed walking with a walker, something she had not been able to do for years. However, the unfortunate woman is now confined to bed with unexplained pain in her legs. In South Korea, ESC researcher Kim Sun-Jong lied about test results and admitted fabricating stem-cell lines. And his colleague Hwang Woo-Suk published false reports in at least two U.S. journals. Woo-Suk is under investigation for embezzling research funds.

Adult stem cells (ASC) are on the other side of the controversy and have a more positive story. Most human tissue has adult stem cells in it. But in some tissue and most tissue from the aged, these cells are difficult to identify and isolate. Like ESC, ASC can grow into a variety of human tissue. So far, ASC have been harvested from adult bone marrow, the umbilical-cord blood of healthy full-term infants, placentas, and even menstrual blood.

Commercial applications of ASC are just surfacing. For instance, Tissue Regeneration Inc., Medford, Mass., is using them to develop a silk-based protein matrix on which to grow tissue to repair anterior cruciate (knee) ligaments. The National Center for Regenerative Medicine, Cleveland, has spun off four biotech companies that are further developing applications for ASC. Arteriocyte Inc., for instance, is developing ASC therapies to grow blood vessels for patients suffering from vascular diseases. RegenerX, another spin off, focuses on using adult stem cells to heal injured heart tissue. The implication is that the ability to heal hearts may make heart transplants and all their complications history.

Better yet, the Cleveland Center's efforts are paying off. Its literature reports that five patients have been successfully treated with ASC — three for leukemia, one for an improperly healing fracture, and one with non-Hodgkins lymphoma.

The developments are also good news for the design community because specialized equipment will be needed for experiments and to grow tissue. Research will require temperature controlled growing chambers and monitoring equipment along with hoses, pumps, and filters.

So shame on researchers who thought it would be a good idea to harvest stem cells from fertilized human eggs. And a pox on federal-government ninnies who now won't fund any stem cell research because they treat the topic as tainted. (Several state governments, such as California and Ohio, are not so myopic. They view the technology as a growth industry and are funding it.) Adult stem-cell research is in its infancy with enormous potential. It's not the time for discussions in whispers.