Thursday April 27 1:51 AM ET
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Iowa Sen. Tom Harkin held up a piece of paper on which he had made a small dot with the point of his pencil.
"That's how big the embryo is," he said. Harkin sides with scientists and senators who want to press ahead with research involving embryonic stem cells. But opponents say getting the cells involves the taking of a human life, and that no end justifies it.
The debate should start coming to a head next month when the Senate debates a bill designed to accelerate the research.
Experts think the research has the potential to transform medicine, offering treatments and even cures for diseases such as juvenile diabetes, in which the pancreas is partly destroyed, heart disease and Parkinson's.
The cells seem so powerful because, when taken from very early embryos, they still "know" how to become any kind of cell in the body. The hope is to direct this development so they can be used for tissue and even organ transplants.
But current law forbids the use of federal funds to harm a human embryo, so federally funded scientists may not extract these cells from human embryos to use for research.
Harkin, who supports a bill that would specifically allow such research, was challenging one of the bill's main opponents, Kansas Republican Sen. Sam Brownback.
"The Stem Cell Research Act of 2000 seeks to allow federal funding for researchers to kill living human embryos," Brownback told Wednesday's hearing of the Senate Appropriations Subcommittee on Labor, Health and Human Services.
"Clearly we must continue to fight to help cure disease and alleviate suffering. However, it is never acceptable to deliberately kill one innocent human being in order to help another."
Pennsylvania Republican Sen. Arlen Specter, the bill's sponsor, says he does not believe that the tiny, frozen embryos, left over from in-vitro fertilization (IVF) fertility treatments, are human beings. Specter points out that the embryos will be discarded if they are not used for research.
Many scientists classify the tiny clusters of fewer than a dozen cells as "pre-embryos" because they are not yet at the stage where, if they were developing inside a woman's body, they would have implanted in the uterus. They also lack the "primitive streak" -- the first signs of a spinal cord.
"In some cases, you cannot see it without a microscope. To equate that with an individual person that Nazis were experimenting on is to stretch the meaning of humanness," Harkin said.
"There are leftover humans of this size -- about a hundred thousand of them, in liquid nitrogen. Regardless of what you think about IVF, what are you going to do with them?"
Christopher Reeve, an actor paralyzed in a riding accident who has become a spokesman for people with spinal injuries, told the hearing it would be "criminal" to let the frozen embryos go to waste.
"I have only a small lesion about the width of your pinky at the second cervical vertebra," Reeve told a news conference after the hearing.
He said his hope was that stem cells could be injected into the spinal cord and would take cues from their new environment to form new nerve cells to restore the connection.
"They would become new neurons to replace those that have been damaged by atrophy," Reeve said.
Specter said he hoped the debate would go the way of the fight over using tissue from aborted fetuses for treating diseases such as Parkinson's. "After extensive consideration, fetal tissue is now used for medical research," Specter said.
"There had been concerns that the use of fetal tissue for medical uses would promote abortion and I think those fears have been laid to rest."
He said South Carolina Republican Sen. Strom Thurmond had been instrumental in turning around conservative opinion on fetal tissue research and he hoped Thurmond would do the same for the stem cell debate.
"Stay tuned, ladies and gentlemen. This debate isn't over," Specter said.