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[IPm] E-News 3/12/2000


WASHINGTON, Feb. 28 -- Scientists said today that they had used stem
cells -- "master cells" that are the source of new cells in the body -- to reverse
diabetes in mice.

The scientists at the University of Florida in Gainesville said their
experiment was a first demonstration that the cells were as valuable as researchers
have said they would be in treating disease.

The scientists said they have already started testing human cells in the
laboratory and thought those cells would work, too.

Stem cells have been the subject of much interest since their potential was
discovered just over a year ago. Researchers said the cells could be used
as tissue transplants, or even as a source to grow whole new organs.

Blood stem cells are routinely used to replenish the bone marrow of cancer
patients when chemotherapy or radiation therapy destroys it. The other stem
cells are elusive, but have been identified in the brain, muscles and other

One example often cited by those who press for more stem cell research is
the method's potential to treat diabetes.

Dr. Ammon Peck and the team at the University of Florida say they have
finally shown the method's value. Writing in the journal Nature Medicine, they said
they isolated stem cells from the pancreases of mice, got them to grow,
transplanted them into diabetic mice and showed that they worked to produce insulin.

Type-I or juvenile diabetes is caused when a person's immune system
mistakenly turns against insulin-producing cells and destroys them. A person with the disease no longer produces enough insulin to control levels of blood sugar
and must take insulin daily.

About 10 percent of the estimated 16 million Americans with diabetes have
type-I diabetes.

Scientists have tried to transplant the insulin-producing islet cells, but
the method does not work well and the cells are scarce. The hope has been that
stem cells could be used instead.

"To reverse diabetes, you need to either take a transplant of the whole
pancreas or the islets," said Dr. Desmond Schatz, a professor of pediatrics and a
diabetes expert who worked on the experiment. "Here the potential is you
can take stem cells, grow them up, and they grow into islets that are capable
of reversing disease," Dr. Schatz said.

Scientists do not really know what a stem cell looks like; they only know
they produce more cells. Islet cells, Dr. Schatz's team knew, come from cells
known as pancreatic ductal epithelial cells, so they took some of those cells and
grew them in a culture in the hope that they would get stem cells.

Apparently, they did: in laboratory dishes the cells seemed to produce
insulin in response to sugar. Those cells were then implanted in mice specially
bred to develop diabetes.

"We were able to show a reversal" for a short period, Dr. Schatz said. The
scientists killed their mice to look at the cells, so they did not know how
the effects would have lasted.

"The next step is take this into humans," Dr. Schatz said. "In preliminary
experiments it appears that we can take human pancreatic duct cells and
show that they can differentiate into islet cells as well."

Dr. Schatz said the source of the stem cells was organ donors -- people who
have died of various causes and donated their organs.

One of the controversial sources of stem cells is early embryos -- usually
left over from attempts to make test-tube babies. Dr. Schatz said that if organ
donors could be used as a source, "you could potentially bypass embryonic

The journal article "emphasizes the enormous potential of stem cell
therapy," David Sachs and Susan Bonner-Weir of Joslin Diabetes Center in Boston wrote in a commentary.

Dr. Joe, the Diabetes Doctor

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