Actress Mary Tyler Moore (search) says she opposes abortion, but she also doesn't like President Bush's reluctance to expand research using stem cells (search) from human embryos to achieve medical breakthroughs.

Moore, diagnosed more than 30 years ago with juvenile diabetes (search), likened the harvesting of stem cells from unused, donated fertilized eggs to organ donations.

"It is the true pinnacle of charity," she said, appearing Wednesday with House members who want new lines of stem cells made available for research. "Federal support for stem cell research ... is the best way to ensure it is undertaken with the highest of ethical standards," she said.

The lawmakers used the occasion to say they were sending Bush a letter, signed by 206 members, mostly Democrats but including some conservative Republicans who oppose abortion.

They said research on stem cells may hold the key to several diseases, including diabetes, cancer, heart disease, Parkinson's (search), Alzheimer's and multiple sclerosis.

Stem cells typically are taken from days-old human embryos and then grown in a laboratory into lines or colonies. Because the embryos are destroyed when the cells are extracted, the process is opposed by some conservatives who link it to abortion.

Rep. Randy Cunningham, R-Calif., said signing the letter was "a very tough decision."

"I'm pro-life ... but this is an area where we can save lives," he said.

Bush signed an executive order in August 2001 order limiting stem cell research to 78 embryonic stem cell lines then in existence. Today, only 19 viable stem cell lines are available to researchers, according to the National Institutes of Health (search).

White House spokesman Trent Duffy said the president believes the promise of stem cell research can be explored through the available stem cell lines.

"The president continues to believe strongly we should not cross a fundamental moral line by funding or encouraging the destruction of human embryos," Duffy said.