Washington ? Ronald Reagan’s death is invigorating an effort to expand stem-cell research, which scientists believe may help treat Alzheimer’s, the disease that afflicted the former president.

On Monday, 58 senators made public a letter they had sent to the White House on Friday urging President Bush to expand the number of stem-cell lines available for research; 206 members of the House of Representatives signed a similar letter on April 28.

Sen. Orrin Hatch, a Utah Republican and author of the Senate letter, said that Reagan’s death and Nancy Reagan’s advocacy for stem-cell research has helped sway conservatives.

“I believe that Nancy Regan has a lot of influence on this,” Hatch said. “I am just hopeful that we can make headway here.”

Signers of the letter included 43 Democrats, the Senate’s sole independent and 14 Republicans, including some who oppose abortion.

Stem cells typically are taken from human embryos and grown in a laboratory. Because the embryo is destroyed, some conservatives oppose the process, likening it to abortion. They fear that allowing use of stem cells would create a market for human embryos. Some also fear the possibility of human cloning.

Embryonic stem cells theoretically can grow into any of the body’s cell types, making them valuable for scientists who believe the cells can lead to better treatments and possible cures for disease and disabilities that afflict 128 million Americans.

But research has been hamstrung by Bush’s August 2001 policy, which limited federal funding of research to stem-cell lines existing at that time. While the administration said that 78 such lines exist, the National Institutes of Health said only 15 to 19 are viable for research. In a letter to Congress, an NIH director said that access to additional stem cell lines may speed life-saving research.

Harvard University and Stanford University have continued their stem-cell research with private donations to get around the ban on federal funding. Meanwhile, scientists overseas continue to pursue the research. Earlier this year, South Korean researchers successfully cloned a human embryo and culled stem cells from it.

The ban on federal money means top scientists are leaving the United States, Hatch said.

Bush stands by his stem-cell position, a White House spokesman said.

“The president continues to believe we need to explore the promise of stem-cell research without crossing the fundamental, moral line by funding or encouraging the destruction of human embryos,” said Trent Duffy, White House spokesman.

In a speech last month, Bush made what some saw as an oblique reference to the stem-cell debate. “Life is not just a tool, or a commodity, or a means to other ends,” he said.

The polarized politics of abortion may prevent any quick policy changes. Hatch said that Bush is unlikely to budge before the elections because the political stakes are so high.

“An open mind is important here. You can get too caught up in the ideology and forget about the welfare of mankind,” Hatch said.