RENEE MONTAGNE, host:
In this part of the program, we're going to look at a couple of promising developments for those who've become disabled. In a moment we'll hear about an eye bank in Seattle that's helping restore vision for people around the world. First, NPR's Richard Knox tells us about researchers who are reporting progress in making new tissue for children who have been in serious accidents.
RICHARD KNOX: This is a success story about five young Mexican boys whose urinary tracts were terribly damaged in car accidents. Researcher Anthony Atala says none of these boys could urinate normally.
Dr. ANTHONY ATALA (Researcher): When they first come in, they have a leg bag that drains urine and they have to carry this bag around with them everywhere they go. And it's also uncomfortable and painful.
KNOX: Atala and his colleagues at Wake Forest University in North Carolina collaborated with doctors in Mexico City to build these boys new urinary tubes. Their report is in the British journal The Lancet.
The first thing they did was to remove a small section of each boy's bladder.
Mr. ATALA: The piece of tissue we take is very small - less than one-half the size of a postage stamp.
KNOX: They grew the bladder cells in laboratory dishes until there were 100 million of them. Then the researchers layered thin sheets of cells onto a cylinder made out of biodegradable material. A week later, the cells covered the cylinder, creating a tube of tissue about as long as a deck of cards with a diameter a little bigger than a soda straw.
The researchers stitched these made-to-order tissue tubes into the gaps in the boys' urinary systems. That was six years ago. In every case the boys' re-engineered urinary systems are functioning normally.
Mr. ATALA: Typically, if you're going to see these structures fail, they can fail early or they can fail late. But if you have them with this long of a follow-up, then you know that they're going to do well over time.
KNOX: Atala says the procedure has transformed the boys' lives.
Mr. ATALA: These children now are totally normal children, running around and doing the things they usually do.
KNOX: The procedure might ultimately help thousands of children not only those who suffer injury, but those with urinary birth defects, which are pretty common.
Dr. Dario Fauzo of Children's Hospital in Boston says the report is encouraging, but it's only a first step.
Dr. DARIO FAUZO (Children's Hospital, Boston): We are only talking about five patients, which is certainly not enough for widespread, meaningful conclusions.
KNOX: Fauzo says it's not clear if the implanted cells did the job or stimulated other cells in the boys' systems to heal the damage.
Mr. FAUZO: We don't know if the cells that were put in there are still there. But that they did something helpful, it appears they did.
KNOX: Scientists have had lots of disappointments over the years as they've tried to grow replacement parts, but Fauzo says it looks like the field of tissue engineering is finally moving ahead.
Richard Knox, NPR News.