Debate Over Stem Cell Research Continues

A stem cell has the ability to turn into any organ in a person's body if it gets the right signals and is in the right environment.

Here's how embryonic stem cell research works. Scientists thaw frozen embryos and remove the stem cells. The cells grow in a Petri dish, where they continue to multiply and divide.

It's at an early stage of cell division that researchers say the potential exists to turn the cells into any of the body's more than 200 tissue types. For example, they can make muscle cells to repair a damaged heart, nerve cells to cure Parkinson's disease or pancreatic cells to cure diabetes.

Dr. Joanne Kurtzburg heads up the stem cell transplant program at Duke. Right now, Duke does not do embyronic stem cell research. Instead, Kurtzburg uses blood stem cells from the umbilical cords of newborn babies to treat cancers and other disorders.

Unlike embryonic stem cells, cord blood cells have a limited number of uses.

"They're capable of forming blood cells, immune cells but not necessarily cells that can give rise to other organs in the body," she says.

Kurtzburg says that while embryonic stem cell research is promising, it will not happen overnight.

"The amount of work that needs to be done is enormous, and you know there's a lot of distance to be covered before this is an everyday treatment," she says.

There are still several hurdles to cross. Scientists have successfully used embryonic stem cells to create nerve cells, which they have implanted the cells into the the brains of Parkinson's patients.

It worked for a while -- the new cells produced the chemical that was missing in the brain, but after a certain amount of time, the cells started to overproduce that chemical because they lacked the signal needed to stop the production.

Experts also hope to find ways in the lab to keep stem cells from "aging" so they could use one or two embryos to create all the tissue they need. Right now, they cannot stop stem cells from maturing into a particular type of tissue.