Shawn asks:

> mouse-contaminated?  Maybe I missed some news on the subject, have any
> non-NYT "news" links?

Here's a basically right-wing, "non-mainstream media" report on the subject:

=======================================

White House Disputed 'Contaminated' Stem Cell Report
NewsMax.com Wires
Tuesday, Jan. 25, 2005

The White House is shrugging off a new study that suggests contamination of
the existing lines of embryonic stem cells could bar their use in treating
disease.

Press Secretary Scott McClellan says the president is satisfied those
existing lines are "adequate" for the "basic research that needs to be done."

In 2001, Bush barred federal funding of experiments using new lines of human
stem cells. He cited ethical concerns with harvesting those cells from
destroyed embryos.
But yesterday, a University of California San Diego group cast new doubt on
the existing lines, which were grown using tissues from mice and other animals.
The group said its studies show animal contamination could provoke an immune
reaction in humans.

McClellan says Bush knew about the issue in 2001, but agreed with the view of
top government scientists that it wouldn't prevent research into potential
breakthrough disease cures.

========================================

And here's an American Medical Association report on the same subject, but
these people are among the "elite of the elites" and are obviously not to be
trusted:

=========================================

PROFESSIONAL ISSUES

Embryonic stem cell line found to be contaminated
The NIH Stem Cell Task Force chair said the discovery may lead to
congressional hearings.
By Andis Robeznieks, AMNews staff. Feb. 14, 2005.

New calls for expanding the number of embryonic stem cell lines were sounded
after University of California, San Diego, researchers identified an animal
molecule that has contaminated one of the stem cell lines in the National
Institutes of Health stem cell registry.

The contamination is believed to have occurred because the stem cell line in
question was cultured using a layer of mouse cells. Since all the stem cell
lines in the NIH registry have been grown using either mouse or fetal calf
cells, they all are believed to be contaminated in the same way.

The UCSD researchers noted that many people have antibodies that attack the
contaminating molecule -- N-glycolyneuraminic acid -- so any tissues developed
using contaminated stem cells may result in a "deleterious immune reaction
and/or rejection of the transplanted cells."

In the study, published online in the journal Nature Medicine on Jan. 23,
researcher Ajit Varki, MD, and colleagues conclude that "it would be safest to
start over again with newly derived [human embryonic stem cells] that have never
been exposed to any animal products containing Neu5Gc and ideally, only ever
exposed to serum from the intended transplant recipient. The current
regulatory climate in the United States precludes this type of approach when using
federal grant dollars."

Some critics of the Bush administration stem cell policy, which limits
government funding for embryonic stem cells to existing lines, have taken this as a
call to scrap the NIH registry and start all over, but Dr. Varki said that was
not their intention.

"We are not saying that the existing approved lines are useless for further
research," Dr. Varki said in an e-mail. "We are only saying that there are
concerns about putting them into living humans, because of the potential for
immune reactions and/or rejection. Prior to taking that step, this problem either
needs to be solved -- or alternate lines need to be generated that are free of
this problem."

James F. Battey Jr., MD, PhD, who chairs the NIH Stem Cell Task Force, said
it had long been suspected that using animal feeder cells to culture stem cells
may lead to contamination, so he was grateful to Dr. Varki for identifying
the source of contamination. "Having a molecular identity for this helps us get
a handle on monitoring it," Dr. Battey said. "But I disagree that cells
derived from these stem cell lines will be rejected."

Dr. Battey said humans ingest Neu5Gc in meat and dairy products without
experiencing immune responses. He added that the Food and Drug Administration had
approved other health care products with animal molecules, and humans have been
able to take those "with no evidence of rip-roaring immune rejection."

The report was bad news for three stem cell-related firms whose stock prices
fell after the report's release. One, Rhode Island-based MultiCell
Technologies, issued a news release announcing that it only uses adult stem cells, so
it's not affected by embryonic stem cell line contamination.

Dr. Battey emphasized that any medical treatments using embryonic stem cells
are still years away from human trials and stem cell lines in the NIH registry
are suitable for the basic research that still needs to be done.

"This reminds me of the discussions around genetically modified vegetables
with a lot of people saying a lot of things without a lot of analysis and data,"
Dr. Battey said. "We really need to stay factual in an area that is as
emotionally charged as human embryonic stem cell research."

Still, he admitted that this new controversy will not settle down any time
soon. "It wouldn't surprise me if we had congressional testimony on this," Dr.
Battey said.

Jeffrey Kahn, PhD, MPH, director of the Center for Bioethics at the
University of Minnesota Twin Cities Academic Health Center, said identification of
Neu5Gc confirms the widespread suspicion that stem cell lines cultured with animal
feeder cells were contaminated, and it gives ammunition to Bush
administration critics.

"I think it will add impetus to the need to create additional [embryonic
stem] cell lines," Dr. Kahn said. "The identification adds fuel to the fire for
why we need additional stem cell lines -- unless they're able to figure out how
to remove that protein from existing stem cell lines."

Dr. Battey said it may be possible for Neu5Gc to be diluted out of the stem
cell lines by growing them in a culture free of animal cells for 10 to 20
generations.

Some new stem cell lines, created after Bush's Aug. 9, 2001, cutoff date,
were not grown using animal cells, but Dr. Varki and colleagues said they may not
be free from problems, either.

"Of course, the use of an 'all-human' environment carries a different set of
risks (unexpected contamination with novel or newly emerging pathogens)," they
wrote in the Nature Medicine report.

AMA policy supports the use of therapeutic cloning technology for biomedical
research and encourages strong public support for federal funding of stem cell
research.

=========================================

Wirt Atmar

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