Scientists Speed Creation of Stem Cells
By LAURAN NEERGAARD, AP Medical WriterThu May 19, 7:13 PM ET
South Korean scientists have dramatically sped up the creation of human
embryonic stem cells, growing 11 new batches that for the first time
were a genetic match for injured or sick patients.
It is a major advancement in the quest to grow patients' own replacement
tissue to treat diseases.
The same scientists last year were the first to clone a human embryo.
Now they have improved, by more than tenfold, their efficiency at
culling these master cells, thus making pursuit of therapeutic cloning
more practical.
"I didn't think they would be at this stage for decades, let alone
within a year," said Dr. Gerald Schatten of the University of
Pittsburgh. He acted as an adviser to the Korean lab in analyzing its
data, which was being published Friday in the journal Science.
"This paper will be of major impact," said stem-cell researcher Dr.
Rudolph Jaenisch of the Whitehead Institute for Biomedical Research in
Cambridge, Mass. "The argument that it will not work in humans will not
be tenable after this."
This research is not cloning to make babies. Instead, scientists create
test-tube embryos to supply stem cells the building blocks which give
rise to every tissue in the body that are a genetic match for a
particular patient and thus won't be rejected by the immune system.
If scientists could harness the regenerative power of those stem cells,
they might be able to repair damage from spinal cord injuries, diabetes,
Parkinson's and other diseases.
Stem cells also can come from embryos left over in fertility clinics.
But these cells would not be a genetic match for any patient.
Any potential therapy is years away from being tested in people. But the
new research marks several advances:
_Last year's cloned stem cells were from one healthy woman. This time,
the Seoul scientists created stem cells that were genetic matches to
each of 11 patients male and female, as young as age 2 and as old as
56, suffering either spinal cord injuries, diabetes or a genetic immune
disease.
_Last year, it took attempts with 242 donated human eggs to grow one
batch of stem cells. This time, it took an average of 17 eggs per batch
and 14 eggs if they were from women younger than 30.
_The researchers eliminated use of mouse "feeder cells" that, until now,
have been used to nourish human stem-cell lines, easing concerns about
animal contamination.
The research also will add to political sparring over whether to expand
government-funded stem cell research in the United States.
Because culling stem cells destroys the days-old embryo harboring the
cells, President Bush in 2001 banned federally funded research on all
but a few old embryonic stem-cell lines. A vote on whether to ease those
restrictions could come in the House as early as next week.
The South Korean research, funded by the South Korean government,
spotlights the frustration that many U.S. scientists feel at being left
behind.
"It's just going to highlight the tragedy of our current situation in
America where there are technologies that are promising that are not
being pursued by talented American scientists because of ideologic
constraints," said Dr. Janet Rowley of the University of Chicago. The
genetics specialist helped write recent national ethics guidelines on
stem-cell research.
The lead South Korean researcher, Hwang Woo-suk of Seoul National
University, said in a telephone interview, "Therapeutic cloning has
tremendous, tremendous healing potential, but we have to open so many
doors before human trials."
More immediately, the research will allow scientists to watch the very
earliest origins of diseases such as Alzheimer's form inside an actual
patient's cloned, living cells, said neuroscientist Fred Gage of the
Salk Institute for Biological Studies in San Diego. That could point to
new ways to prevent and treat illness, said Gage, who plans to perform
some of that work.
The Seoul researchers collected eggs that were donated by 18 unpaid
volunteers and removed the gene-containing nucleus from them.
The scientists inserted into those eggs DNA from skin cells of the 11
patients and chemically jump-started cellular division. Thirty-one
blastocysts early-stage embryos of 100 or so cells each successfully
grew. From those, the scientists harvested 11 stem cell lines.
Each is a genetic match to the patient who had donated a skin snippet,
and each can form other tissues, such as brain cells or bone cells.
Next, the scientists must learn how to control that cell development.
The work means there may be more demand for donated eggs for medical
research. Women considering doing so must understand they get no benefit
and face some risk, said Stanford University bioethicists David Magnus
and Mildred Cho.
The advances do not mean it is time to try reproductive cloning, Hwang
said. That, he said, "is unsafe and unethical," noting that animal
studies show more failures than successes. "Biologically, it may be
impossible."
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http://news.yahoo.com/s/ap/20050519/ap_on_he_me/stem_cells
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In other news, British scientists announced the cloning of a human
embryo for producing stem cells:
http://news.bbc.co.uk/2/hi/health/4563607.stm
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Meanwhile, the US is still arguing about it.
http://news.yahoo.com/s/ap/20050519/ap_on_go_co/stem_cells_congress
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John Hachmann aa #1782
"Those who can make you believe absurdities can make you commit atrocities"
-Voltaire
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