Lift limits on cells' study, say senators

A majority of U.S. senators have signed a letter asking President Bush to lift the government's funding restrictions on embryonic stem cell research, increasing the pressure to change a policy critics say is holding back potentially lifesaving medical research.

The letter, which is still being circulated for signatures and has not yet released, says the United States is falling behind in research into diseases "that affect more than 100 million Americans" and calls on the president to "expand" the current policy. It has been signed by 56 senators, including conservatives Trent Lott of Mississippi, Kay Bailey Hutchison of Texas, Orrin G. Hatch of Utah, and 10 other Republicans.

Human embryonic stem cells are potent cells that can create any type of tissue in the human body and are thought to have great promise for fighting diseases that afflict millions of Americans. Because they can be created only by destroying a human embryo, the use of the cells for research is highly controversial, and three years ago Bush declared that the government would no longer pay for any research on new lines of stem cells.

The Senate letter, which mirrors a similar one released by the House of Representatives two months ago, is a sign of how the political terrain has changed since Bush issued his policy in August 2001.

Since then, groups representing victims of diseases that might be helped by the research — such as Parkinson's or juvenile diabetes — have been aggressively lobbying members of Congress. This campaign has included pleading visits from children who have diabetes, as well as a powerful speech from former first lady Nancy Reagan. Though many legislators remain firmly opposed to embryonic stem cell research, the campaign has taken some of the partisan edge off the debate and given the president a measure of political cover should he decide to alter the policy.

"I have seen a change (in political attitudes) over the last few months," said Lawrence A. Soler, who heads up the Washington lobbying operations of the Juvenile Diabetes Research Foundation. "This is not a partisan issue."

The Senate effort is fueled by a sense among scientists that the ban is posing more of an obstacle to research in the United States than at first thought. In 2001, the president said the government would pay for research on lines of stem cells that already existed, a number he put at more than 60. Only 19 of those lines have become available to scientists, however. Last month a Globe survey found that most new cell lines are being created overseas, and that federally funded American scientists are aren't able to keep up with the field as it moves forward.