Other Avenues

	Stem cell therapy could give hope to patients of Alzheimer's and Parkinson's disease and other disorders that are caused by the lack of specific cells.

Is there any way around this "ethical minefield?" The answer - as is often the case in philosophical debates - is maybe. Stem cell researchers and research-opponents alike would both prefer to see work done on what are known as adult stem cells, said to be "pleuripotent". Like the "totipotent" embryonic stem cells, adult stem cells divide infinitely and can specialize to become a variety of cell types. Unlike embryonic stem cells, however, adult stem cells can not become just any type of cell.

Blood cells, for instance, come from adult stem cells in the bone marrow. These stem cells can specialize into red blood cells or one of a variety of white blood cell types. But they can't become other cells such as neurons, retina cells or liver cells as embryonic stem cells could. The hope remains that scientists could isolate a variety of adult stem cells that, taken together, could provide all the cells necessary to treat diseases.

Stem cell researchers and research-opponents alike would both prefer to see work done on what are known as adult stem cells.

Scientists are already investigating adult stem cells' therapeutic potential. In Australia, surgeons extracted adult stem cells from a cardiac patient's bone marrow, then injected the pleuripotent cells into the 74-year-old man's ailing heart. There, doctors hope, the stem cells will give rise to new vessel growth. News of the procedure hit the wires the same day Bush urged the U.S. Senate to ban all human cloning.

	Dr. Suku Thambar (right) of the Hunter Medical Research Institute in Newcastle, Australia is working with adult stem cells in a cardiac patient.

Five days later, on April 15th 2002, researchers at the Salk Institute of Biologial Studies published some promising data in the journal Nature Neuroscience. The investigators were able to coax adult stem cells from rat brains into becoming new neurons. This groundbreaking work could lead to cures for paralysis, Alzheimer's and Parkinson's diseases and many other ailments. But, in the Salk experiments, not all the cells became neurons, and - of those that did - not all behaved normally. The Salk scientists aren't sure if the problems were procedural or were rooted in the adult stem cells themselves. Many scientists worry adult stem cells are inherently less useful for therapeutic purposes than embryonic stem cells, but only further research can resolve the questions raised by these and other experiments. And, according to Melton, if that research doesn't happen in the United States, it may not happen anywhere.

"Either it won't happen at all and we'll never know the answers, or it will go so slowly that people will get discouraged," he says. "You need a community of people to make progress in an area. As with growing a tree, if you don't give it enough food and water and sun, it just shrivels."
- - - - - - - - - - - -
3 pages: | 1 | 2 | 3 |

Photo: Australian Broadcasting Corporation