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Lawmakers relaunched their effort to expand medical research using embryonic stem cells. They predict that they will have enough support to push the controversial measure through the Senate.

The measure sets up a new showdown between a growing number of lawmakers who want to boost funding for the research and those who equate it with abortion and seek to ban it outright.

Supporters say the bill would allow important disease research to proceed under strict ethical guidelines. At the same time it bans procedures that could produce a cloned human child. They also argued that federal research standards are now needed to reconcile what has become a "patchwork" of state laws governing the use of research embryos.

The bill restricts embryonic stem cell research to a procedure often called "therapeutic cloning," also known as embryo cloning. The process inserts human DNA from an adult cell into an unfertilized human egg cell. The added DNA allows the cells to divide and produce a human embryo that contains stem cells. Those embryonic stem cells or "master cells" can in turn give rise to dozens of types of human tissue.

Researchers say that cells from the human embryo could then be transplanted back into the original (DNA) donor for therapeutic purposes. The technique offers the chance to cure chronic and degenerative diseases like diabetes, Parkinson's, and Alzheimer's disease. With this technique, unlike transplantation of organs, there is no fear of tissue rejection. This type of cloning allows the creation of a perfect match of tissues.

Limits on Stem Cells

But the bill limits research to embryos 14 days or younger, a time when it shows no human qualities and cannot survive on its own. It also requires the National Institutes of Health to set strict ethical guidelines, including a ban on the sale of embryos or eggs.

The proposal also outlaws cloning as a means of reproduction to produce a child, and it exacts a 10-year prison sentence and a $1 million fine on any scientist who attempts to do the procedure.

Sen. Orrin Hatch, R-Utah, the bill's lead sponsor and also one of the strongest abortion foes in the Congress, says embryonic cell research is vital to mounting "a major effort" against a host of diseases.

"One of the best ways to be pro-life is to help take care of the living," Hatch says. "I have never believed human life begins in a Petri dish."

Expanding Stem Cell Research

A decision by President Bush in August 2001 limited federally funded embryonic stem cell research to 77 cell lines already in existence at the time. Critics say many of these have proved inadequate for ongoing research because of a lack of genetic variety or potential contamination.

Republican House leaders agreed last month to allow a vote later this summer on proposals to expand the policy. The vote might allow research on embryos stored in fertilization clinics that were slated for destruction. Twice in the past three years the House has passed measures banning all forms of human cloning research, only to face opposition from the Senate.

Hatch and other backers predicted that they would secure the 60 votes necessary to overcome any procedural hurdles in the Senate. But the bill would still face likely opposition from President Bush, who has shown no signs of expanding his 2001 policy.

"We think we can get 60 votes in the U.S. Senate, and if we do it'll put a lot of pressure on everybody to do something about this," Hatch tells WebMD.

Douglas Johnson, the chief lobbyist for the National Right to Life Council, an anti-abortion group, says efforts to ban all cloning also have wide congressional support and that Thursday's bill "has no chance to become law."

A Policy 'Patchwork'

New federal rules on stem cell research would smooth what has become a "patchwork" of state laws that are draining scientists and research money from some jurisdictions toward others, says Sen. Dianne Feinstein (Calif.), the bill's lead Democratic sponsor.

Four states -- California, New Jersey, Wisconsin, and Massachusetts -- have laws funding embryonic stem cell research, while five others, including Arkansas, Iowa, and Michigan, outlaw all cloning studies. More than 20 other states are considering limits on the research.

Supporters also argue that their bill was needed to stem a tide of U.S. researchers who are fleeing to other countries where stem cell research is permitted. "Embryonic stem cell research is going to go on in the world one way or the other," Feinstein says.

Sam Brownback, R-Kan., who supports banning all forms of cloning research, said he will "aggressively oppose Thursday's bill. Brownback tells WebMD that embryo research is "unnecessary" because dozens of clinical trials using adult stem cells or cells from umbilical cord blood are in progress.

"We are getting cures in an ethical fashion," he says.

By Todd Zwillich, reviewed by Brunilda Nazario, MD

SOURCES: Sen. Orrin Hatch (R-Utah). Sen. Dianne Feinstein (D-Calif.). Sen. Sam Brownback (R-Kan.). Douglas Johnson, chief lobbyist, National Right to Life Committee.