Though the California Nurses Association officially favors embryonic stem cell research, the organization Thursday announced its opposition to Proposition 71, the ballot measure that would fund stem cell studies with a $3 billion bond issue.
Leaders of the group, representing about 58,000 registered nurses statewide, said they felt the measure could allow private drug companies to patent discoveries and benefit from the research at public expense.

They also said they feared women who voluntarily donated their eggs for research would not be properly informed of the medical risks.

"Rather than having patented medicine ... it should be an open source of information for all citizens of California," Deborah Burger, president of the CNA, said at a Sacramento news conference.

"As it is structured, very few people will be able to afford these technological or medical or biological advances."

Roger Salazar, a spokesman for the Yes on 71 campaign, said the initiative mirrors the way federally sponsored research is funded through the National Institutes of Health.

"The basic research is generally done in universities, research institutions, nonprofits, but as you move forward and get it to the developmental stage where you can bring it to the public, you partner up with private companies," he said.

"In order to bring that product to the marketplace, they need to have some sort of (financial) incentive."

Salazar said the nurses' fears that women would be asked to donate embryos without being advised of the risks were unfounded. Most of the embryos used in the research will be leftovers donated by clients of infertility clinics, he said.

Thursday's announcement from the CNA and several other women's health groups places them on the same side as anti-abortion groups and the state Republican Party, previously the highest-profile opponents to Proposition 71.

Embryonic stem cells come from days-old embryos and can morph into any cell in the human body.

Scientists say they could find cures and treatments for some diseases by repairing or replacing damaged cells with new material developed from stem cells.

But retrieving the cells requires destroying the embryos, which abortion foes oppose.

Burger said the CNA adamantly favors abortion rights.

"CNA is a pro-choice, pro-stem-cell-research organization," she said. "It was very, very difficult to come to this decision because we do support stem cell research and we do believe in a woman's right to choose."

Opponents of the measure face an uphill battle.

They have raised about $150,000 and are unlikely to have any media campaign, while proponents have raised more than $20 million and have aired television commercials for weeks. A recent Field Poll found the measure is slightly ahead, with 46 percent of likely voters supporting it and 39 percent opposed.

Proposition 71 supporters this week began airing a television ad featuring actor Michael J. Fox, who has Parkinson's disease, one of the illnesses for which stem cell research might find a cure.