Hi all --
The following excerpts from an article from the July 16th Chicago Tribune
examines the differences between adult stem cells and embryonic stem
cells. Are they really equal options for research?

Full Article at:
http://www.chicagotribune.com/news/nationworld/article/0,2669,1-010716022
8,FF.html

Science explores stem cell options
By Jeremy Manier and Ronald Kotulak, Tribune staff reporters. Tribune
staff reporter Peter Gorner contributed to...

 " As the political fortunes of embryonic stem cell research hang in
the balance, scientists increasingly are looking for alternatives in
case federal funding for work on human embryos falls through.

... Opponents of such research argue that some alternatives are at
least as promising as embryonic stem cells, which may be able to
regenerate tissue to cure ailments such as diabetes and Parkinson's
disease. The desperate search for other research options has led to
possible stem cell sources in adult bone marrow, cells made by
mimicking the process of cloning and even fat tissue.

Yet some of the alternatives, such as fat, almost certainly are dead
ends, according to stem cell experts. Adult stem cells from bone
marrow show more promise and have reached human trials for some
diseases. Even so, experts say, such cells have lacked the power of
embryonic stem cells to form virtually any type of tissue.

For those reasons even the most prominent adult stem cell researchers
say they support federal funding of work on cells from embryos.

"The vanguard of the field has really been the embryonic work," said
Dr. Ira Black, a neuroscientist from the University of Medicine and
Dentistry of New Jersey. Last year, Black presented the first report
showing adult stem cells from blood could be transformed into brain
cells..."

"Using adult stem cells

Although adult stem cells can become several different tissue types,
there is little hard evidence that they can replicate essential
functions, said Dr. Irv Weissman, a Stanford University scientist and
pioneer of adult stem cell research.

"We have a small number of intriguing experiments in mice where we
could show, for example, that a blood-forming stem cell could turn
into liver," Weissman said. "But almost all of the other experiments
that were done, even with mice, are not rigorous experiments--they're
sort of flashes out of the box."

Most adult stem cell research has focused on cells from bone marrow. A
potential advantage of adult stem cells is that unlike embryonic stem
cells, which have never been transplanted into humans, doctors have
decades of experience with bone marrow transplants for cancer
patients..."

Misinterpretations

"Some adult stem cell researchers, however, said the implications of
their work have been exaggerated.

When Dr. Diane Krause of the Yale University School of Medicine
published a study in May suggesting bone marrow cells could form
liver, lung and skin cells, some opponents of embryonic research
claimed the results showed adult stem cells are just as flexible as
stem cells from embryos.

Yet Krause said her study could not show the cells were functioning in
their new roles.

"It was based on 10 mice," said Krause, who supports embryonic stem
cell research. "I would call that scant evidence. That doesn't mean
it's not true. But we have no idea how it happened."

Similar misinterpretations sprang from a much-publicized April study
in which researchers obtained muscle and bone cells from fat tissue,
according to Gearhart of Johns Hopkins. Because the researchers never
isolated individual stem cells, they could not know if the new cells
came from fat or from blood that circulated through the fat tissue,
Gearhart said.

Many researchers said the relative strengths of adult and embryonic
cells will never be known until they can be tested against each other.
And that is almost impossible without federal funding for embryonic
cell research, said Dr. Evan Snyder, a stem cell researcher at Harvard
University...."

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