Carol Etherington

President, Board of Directors Medecins Sans Frontieres U.S.A./
Doctors Without Borders
Nashville, Tennessee

I've been a nurse for more than 30 years, and I've worked with Medecins Sans Frontieres for nearly 10 of those years. We go into the most desperate situations to provide medical relief. We can respond to just about any problem anywhere in the world within 24 hours.

For a long time, MSF, like many medical programs, had a straightforward mission: Go in, diagnose, and cure. And of course we found ourselves in situations where we couldn't "cure," because the population didn't have access to medicines, or we couldn't get access to them, or the situation was simply too overwhelming. We asked, "How do people cope with ongoing hopelessness and helplessness?" So in the early 1990s, MSF made a commitment to making mental health a strong component of our comprehensive health-care program. Usually, that comes down to building, or rebuilding, a sense of community.

Angola in 2001 was different from most missions. We couldn't start a full mental-health program because the physical and medical needs were too great. But we brought people together. We were ready to listen, not talk. At a feeding center, we played with children, drawing pictures in the dirt. There was a place for mothers to gather. Many of them didn't want to talk. Their situations were too painful. So we just sat together, pounding maize.

Back home, though, I spoke up. People don't know enough about the plight of those caught in the 27-year Angolan civil war. And health is inextricably linked to human rights. In accepting his speech for the 1999 Nobel Peace Prize, James Orbinski, then president of MSF, said it best: "We do not know if words can save lives, but we do know that silence can kill."

David Humes

Founder and chief scientific officer, Nephros Therapeutics
Professor of internal medicine, University of Michigan Medical School
Ann Arbor, Michigan

They say that luck only works if you have a prepared and open mind. Back in 1992, my lab director called and said, "The cells are doing funny things. They're clumping together." We weren't looking for that. We were just looking at how cells behave in various conditions based on a clinical observation that in survivors of acute kidney failure, the kidney could heal itself. We figured that if it could heal itself, then there must be cells that had the ability to repair themselves back to full function.

It turns out the clumping meant that the cells could be regenerative. At the time, the notion that we could proliferate stem cells from an adult kidney, or any other organ for that matter, was hardly the conventional wisdom that it is today. Nobody believed us.

That day in the lab, we could have thrown out the experiment. Clumping wasn't part of our hypothesis. Instead, we investigated and hit on something big. Some of the most dramatic insights come from experiments that do not turn out as predicted.

We've been building a bio-artificial kidney for nearly a decade now. The prototype for treating acute renal failure is a foot-long cartridge filled with a billion human kidney cells. Inside, 5,000 tiny fibers house the cells, which supply vital hormones and enzymes that a dialysis machine couldn't. In kidney-replacement therapy today, the dialysis cartridges are just synthetic membranes. Ours are living. They grow. They can repair themselves.