By Rick Weiss
Washington Post Staff Writer
Saturday, July 15, 2006; A04
With just days to go before the Senate is scheduled to vote on a hotly anticipated bill that would loosen President Bush's restrictions on human embryonic stem cell research, both sides of the scientifically and ethically charged issue have ramped up their publicity machines and attacks on each other.
As the week drew to a close, commentators opposed to the research, such as William Kristol, editor of the conservative Weekly Standard, released fiery commentaries urging senators to reject the bill. And several scientific and medical groups, including the American Society for Reproductive Medicine, released countervailing warnings that patients and their families would suffer if the bill failed.
Yesterday, in one of the more incendiary volleys, the journal Science published a letter by three researchers documenting apparently significant misstatements made by a leader in the movement to block the bill.
The legislation, already passed by the House, would for the first time allow scientists to use federal funds to conduct research on new colonies of the medically promising cells, which are controversial because human embryos must be destroyed to obtain them.
The bill would override rules put in place by Bush five years ago that restrict federal funding to research on only those embryonic stem cells that were in existence as of August 2001. That policy is aimed at protecting human embryos, but it has been widely decried by researchers and patient groups as a roadblock to the development of treatments for a range of diseases.
The letter to the journal focused on David A. Prentice, a scientist with the conservative Family Research Council. Prentice has been an adviser to Sen. Sam Brownback (R-Kan.) -- a leader in the charge to maintain tight restrictions on the research -- and an "expert source" often cited by opponents of embryonic stem cell research.
Prentice has repeatedly claimed that adult stem cells, which can be retrieved harmlessly from adults, have at least as much medical potential as embryonic cells. He often carries a binder filled with references to scientific papers that he says prove the value of adult stem cells as treatments for at least 65 diseases.
In the letter to Science, however, three researchers went through Prentice's footnoted documentation and concluded that most of his examples are wrong.
"Prentice not only misrepresents existing adult stem cell treatments but also frequently distorts the nature and content of the references he cites," wrote Shane Smith of the Children's Neurobiological Solutions Foundation in Santa Barbara, Calif.; William B. Neaves of the Stowers Institute for Medical Research in Kansas City, Mo.; and Steven Teitelbaum of Washington University in St. Louis.
For example, they wrote, a study cited by Prentice as evidence that adult stem cells can help patients with testicular cancer is in fact a study that evaluates methods of isolating adult stem cells.
Similarly, a published report that Prentice cites as evidence that adult stem cells can help patients with non-Hodgkin's lymphoma does not address the medical value of those cells but rather describes the best way to isolate cells from lymphoma patients and grow them in laboratory dishes, the letter said.
And Prentice's reference to the usefulness of adult stem cells for patients with Sandhoff disease -- a rare nerve disorder -- is "a layperson's statement in a newspaper article," the scientists reported.
All told, the scientists concluded, there are only nine diseases that have been proved to respond to treatment with adult stem cells.
"By promoting the falsehood that adult stem cell treatments are already in general use for 65 diseases and injuries, Prentice and those who repeat his claims mislead laypeople and cruelly deceive patients," the scientists wrote.
Prentice, in a brief voice message left for a reporter as he embarked on a trip yesterday, said, "I appreciate them pointing out some of the things . . . that need to be changed and updated." But he accused the letter writers of "mental gymnastics" by focusing narrowly on proven therapies, as opposed to the large number of diseases for which the value of adult stem cells is now being tested.
Majority leader Bill Frist (R-Tenn.) announced this week that the Senate will debate the bill to loosen Bush's rules on Monday and vote on Tuesday. Under the terms of an agreement worked out with Democrats, the bill will need 67 ayes to pass, a count most observers believe will be achieved.
The Senate will also vote on two other bills -- one aimed at preventing abuses in fetal research and one encouraging a search for non-embryonic stem cells that might have the same healing potential as embryonic cells.
Both bills are expected to pass easily and to be taken up and passed by the House on Wednesday and Thursday, congressional aides said. At that point, President Bush would be free to follow up on his oft-repeated promise to veto the bill that would loosen his rules.
That could come as early as Thursday, the aides said, and would constitute the first veto of Bush's presidency.
The House could follow by Friday with an attempt to override that veto. Current head counts suggest that an override attempt in the House would fail. If so, the bill would be dead without the Senate having to reconsider the issue.
Last week, the two leaders in the effort to loosen Bush's rules -- Reps. Michael N. Castle (R-Del.) and Diana DeGette (D-Colo.) -- sought an audience with Bush as part of a last-ditch effort to persuade him not to veto the measure.
Last Friday, they said they were told he would not have time.