Embryonic stem cells show the most immediate promise for helping patients with spinal cord injuries, said Sean Tipton, spokesman for The Coalition for the Advancement of Medical Research.

Spinal cord injuries

Geron Corp., based in Menlo Park, Calif., expects to be the first U.S. company to test an embryonic stem cell treatment in a clinical trial.

The company has successfully injected neural cells - derived from animal embryonic stem cells - into mice with spinal cord lesions. The neural cells repaired the myelin, or coating around the nerve cells, allowing the nerve cells to function.

"Which means," said spokesman David Schull, "a paralyzed rat can walk."

He added: "We expect to complete the [investigational new drug] filing with the [Food and Drug Administration] by the end of year. The plan is to enter the clinic in 2008."

Diabetes

In May, Geron announced its affiliated researchers had turned embryonic stem cells into clusters of cells that secrete insulin in response to elevated sugar levels.

In those with Type I diabetes, the "islet" cells of the pancreas that normally produce insulin are destroyed by the immune system. They often need cell transplants from pancreas donors, but there is a severe shortage.

The next step will be to improve the quality of the insulin-secreting cells, then use them to create normal blood sugar levels in lab animals, Geron said.

The results are limited but represent "some definite progress," said Peter Cleary, spokesman for the Juvenile Diabetes Research Foundation.

One to watch

The California Institute for Regenerative Medicine is a state agency created to oversee the distribution of $3 billion in public funding over the next 10 years.

"It's our objective to have one stem cell-based therapy in a Phase II clinical trial at the end of 10 years, with five or six more ready to move into the pipeline," said spokesman Dale Carlson.

- By Lisa Rosetta