by Karen Weintraub, Special for USA TODAY

KING5.com

Posted on April 30, 2014 at 3:48 PM

Two new studies out today show both the incredible promise of stem cell research and its current limitations.

In one, published in the journal Nature, researchers showed that they could repair damaged hearts by injecting these versatile stem cells into macaque monkeys. Heart disease is the leading cause of death, and if the same process can work in people, it could benefit hundreds of thousands a year.

In the other study, published in Science Translational Medicine, five men were able to regrow leg muscles destroyed by accidents or military service. The researchers, from the University of Pittsburgh, inserted into the men's muscles a "scaffold" of muscle tissue from a pig. Through aggressive physical therapy right after the surgery, the men's own stem cells were encouraged to populate the scaffold and substantially rebuild their leg muscles.

Nothing had been able to help these men before, including multiple surgeries and years of physical therapy, said Stephen Badylak, the study's senior author.

"Frankly, most of these patients have been through hell," he said at a Tuesday news conference.

David Scadden, a physician and co-director of the Harvard Stem Cell Institute, said he was impressed with the rigor and promise of both studies.

It's long been a goal of stem cell research to figure out how to help the body regrow damaged tissue, he said, and both studies mark a significant step toward that goal.

Originally posted here:
Stem cells used to repair animal hearts and human muscle