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January 12, 2007

More News on Stem Cell

Stem cell bill sails through House
By JIM KUHNHENN, Associated Press WriterFri Jan 12, 7:39 AM ET
The House voted to expand government-financed embryonic stem cell research Thursday, but for the second time in two years lawmakers were unable to muster enough votes to overcome a promised presidential veto.

Still, the 253-174 vote was a high watermark in the stem cell debate, drawing advocates closer to the two-thirds vote threshold needed to override President Bush's objections.
With stem cells offering hope for major health care cures, lawmakers on both sides of the issue punctuated the debate with poignant personal stories and clashed over the ethics of the science.

Addressing "those who do not have the will to stand up against a presidential veto," freshman Rep. Zach Space, D-Ohio, described his 16-year-old son's battle against juvenile diabetes and wondered aloud what awaited him as an adult.

"This research represents the only meaningful hope for a cure in my son's lifetime," Space said.
Embryonic stem cells hold the promise of medical breakthroughs because they have the ability to become any tissue in the body. But the research typically involves the destruction of frozen embryos created for in vitro fertilization, a step that stirs passions over the beginning of life.
Rep. Virginia Foxx (news, bio, voting record), R-N.C., blind in one eye, said she would benefit from stem cell science to replace a detached retina. But she said the federal government should emphasize research into adult stem cells, not those derived from embryos.

"Killing human life does not have to be accomplished to create efficacious treatment for people and diseases," she said.

The legislation would lift Bush's 2001 ban on the use of federal dollars spent on deriving new stem cells from fertilized embryos.

Bush vetoed similar legislation last year and actor Michael J. Fox elevated the issue into prominence with political ads during last fall's congressional elections. Democrats credit that issue, among others, for helping them drive Republicans from power in Congress.

Thursday's vote set another milestone in the new Democratic leadership's march toward passing a string of campaign promises in the early days of the new congressional session.
In the Senate, however, Democratic efforts to pass a wide-ranging ethics rule ran aground when Republicans, aided by nine Democrats, supported a more restrictive rule governing pet projects that lawmakers tuck into major legislation.

The setback slowed down the Senate's legislative pace and illustrated the brittleness of the Democratic majority. Senate Democratic leader Harry Reid (news, bio, voting record) of Nevada planned to work through amendments to the ethics rules through next week.

The floor debates in both houses occurred against the overwhelming presence of the Iraq war, coming a day after Bush told the nation he would send 21,500 more troops to Iraq. On and off the floor, lawmakers debated Bush's plan, drawn to what was clearly the top issue of the day.
More and more rank-and-file Republicans voiced skepticism about Bush's plan, but GOP leaders prepared to put up obstacles to Democratic efforts to express their opposition with a recorded vote.

Rep. Ric Keller (news, bio, voting record), R-Fla., one of Bush's most ardent supporters, said Thursday he would have agreed three years ago with the president's call for more troops, but not now.

"At this late stage, interjecting more young American troops into the crossfire of an Iraqi civil war is simply not the right approach," Keller told the House. "We are not going to solve an Iraqi political problem with an American military solution."

The House on Friday turns to yet another item on its list of legislative priorities — requiring the administration to negotiate with drug companies for lower prices for Medicare. But that legislation, like the embryonic stem cell bill, also faces a presidential veto.

In a statement Thursday, the administration said, "Government interference impedes competition, limits access to lifesaving drugs, reduces convenience for beneficiaries and ultimately increases costs to taxpayers, beneficiaries and all American citizens alike."
Bush has only exercised his veto power once, when he rejected the last embryonic stem cell bill. The new Democratic majority is likely to elicit more threats in the next two years than he issued in the first six years of his administration.

The embryonic stem cell bill has bipartisan support in the Senate. But the Senate bill, which is not likely to come up for some time, could undergo amendments during floor debate that would require it to be reconciled with the House version.

"You take it one step at a time," said Lawrence Soler, vice president of government relations for the Juvenile Diabetes Research Foundation, which supports expanded federally funded research. "The bipartisan support for the overall issue is going to stand firm. That process will open up opportunities to have discussions with the administration."

Douglas Johnson, the legislative director of the National Right to Life Committee, an anti-abortion group, predicted the congressional debate would be overrun by advances in adult stem cell research, including new reported research that stem cells extracted harmlessly from amniotic fluid have properties similar to embryonic stem cells.

"We expect when the dust settles, the president's policy will be preserved and the science will continue to demonstrate that the stem cells obtained from other sources have far more potential and are far more easy to control," he said.
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The bill is H.R. 3.
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On the Net:
Congress: http://thomas.loc.gov

January 11, 2007

A New Look at Stem Cells

Recently an article was published in the L.A Times regarding stem cells being utilized from amniotic fluid. Although these stem cells may not prove to be as totipotential as embryonic stem cells, it does appear that these stem cells do have potential for developing various cell lines. It appears that they have been used to create bone, heart muscle, blood vessels, fat, nerve and liver tissues. This is extremely beneficial especially from an ethical standpoint. As stem cell research now proceeds, it typically requires using embryonic stem cells and from an ethical standpoint this does appear to be somewhat of a conflicted issue. If it turns out that utilization of amniotic fluid stem cells is beneficial, then this should be added to the present armamentarium of choices that are now available. We should continue to search for new ways to utilize the various stem cell derivatives and do it in an ethical and humane way.
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Stem cells in amniotic fluid show promise
A study finds they offer key therapeutic benefits but avoid controversy.
By Karen Kaplan, Times Staff Writer
January 8, 2007

Researchers have found that some stem cells in human amniotic fluid appear to have many of the key therapeutic benefits of embryonic stem cells while avoiding their knottiest ethical, medical and logistical drawbacks, according to a study published Sunday.

The stem cells — easy to harvest from the fluid left over from amniocentesis tests given to many pregnant women — were used to create bone, heart muscle, blood vessels, fat, and nerve and liver tissues, the study said.

"So far, we've been successful with every cell type we've attempted to produce from these stem cells," said study senior author Anthony Atala, director of the Institute for Regenerative Medicine at Wake Forest University School of Medicine in Winston-Salem, N.C. The report was published online by the journal Nature Biotechnology.

The finding points to a promising avenue of research that sidesteps the hurdles facing embryonic stem cell research, which has been hampered by moral objections to the destruction of embryos that occurs when the cells are harvested.

The objections have been divisive, prompting President Bush to restrict federal funding for most human embryonic stem cell research. Those restrictions have sparked movements in some states to fund research on their own.

California's Proposition 71, approved in 2004, was designed to provide $3 billion for stem cell research but has met a vigorous legal challenge from opponents of the research.

Amniotic stem cell research ducks the controversy because no embryos are destroyed. The National Institutes of Health already funds such research.

The study also suggests another advantage: Embryonic cells can form tumors when implanted in lab animals, but amniotic-fluid stem cells do not appear to do so.

"If everything that people think about them turns out to be true, they'll be a powerful source for therapeutic cells," said Alan Russell, director of the McGowan Institute for Regenerative Medicine at the University of Pittsburgh, who wasn't involved in the study.

It is still unclear whether stem cells from amniotic fluid — the liquid that cushions fetuses in the womb — can produce the range of cell types that embryonic stem cells can.

"They can clearly generate a broad range of important cell types, but they may not do as many tricks as embryonic stem cells," said Dr. Robert Lanza, an embryonic stem cell researcher and head of scientific development at Advanced Cell Technology Inc. in Worcester, Mass.

But even if amniotic stem cells turn out to be less flexible, they still might be an important tool in the nascent field of regenerative medicine.

Dr. Dario Fauza, coordinator of the surgical research laboratories at Children's Hospital Boston, has used the cells to grow tissue to repair defective diaphragms and tracheas in sheep.

He has asked the Food and Drug Administration for permission to do the same for children born with herniated diaphragms. It would be the first human clinical trial involving amniotic stem cells, he said.

Swiss scientists Dorthe Schmidt and Simon Hoerstrup of University Hospital Zurich have used amniotic stem cells to grow heart valves. They are currently testing them in sheep.

The stem cells "may not be as earth-shattering a discovery as human embryonic stem cells, but these cells could prove to be equally important for medical therapy," said Lanza, who was not involved in the study. "I think this is an exciting breakthrough."

Amniotic-fluid stem cells lie somewhere between the two major categories of stem cells: embryonic and adult.

Embryonic stem cells are derived from days-old embryos. Nearly all of the development is still to come, so those cells must be extremely flexible.

That "pluripotency" is the reason researchers believe embryonic stem cells could offer cures for a wide range of ailments. They hope to use the cells to replace the insulin-secreting islet cells of diabetes patients and to grow brain tissue to treat stroke victims, among other treatments. But they don't yet know how.

Adult stem cells are narrowly focused on replenishing specific types of tissue that wear out over a lifetime, such as skin, hair and blood. Researchers around the world are looking for ways to expand the cells' range of capabilities.

Amniotic-fluid stem cells, which are sloughed off by the fetus, are "a different kind of a stem cell," Atala said. "It's not as early as a human embryonic stem cell and it's not as late as the adult stem cells."

Scientists surmised more than a decade ago that amniotic fluid would contain those cells and identified some after several years of searching.

Atala and his colleagues set out to determine just how plentiful and flexible the stem cells might be.

The researchers studied 10-milliliter samples of fluid extracted from pregnant women who had amniocentesis to screen fetuses for genetic abnormalities. Those tests are commonly performed early in the second trimester.

Of the myriad cells that make up amniotic fluid, the researchers found that about 1% had a surface marker that is a hallmark of embryonic stem cells. They took it as a signal that these cells might be pluripotent.

The researchers from Wake Forest and Harvard Medical School biochemically prompted the cells to transform into all of the main categories of embryonic tissue.

A key test was to see whether the cells functioned like normal cells.

Stem cells induced to become neural cells were able to secrete a neurotransmitter when stimulated by potassium ions, mimicking conditions inside the brain, the researchers reported. They also induced stem cells to develop into liver cells that were able to secrete urea, a compound produced in the liver.

Other stem cells that had been coaxed into becoming osteoblasts, which build up bone, were implanted in mice. The cells formed a tissue that was more dense than normal mouse bone, he said.

"You may be able to obtain the same medical benefits — and cure the same diseases — without the risks or controversy associated with embryonic stem cells," said Lanza of Advanced Cell Technology. "It's just what the doctor ordered."

The cells were easy to grow and maintain, and they did not form the tumors — jumbles of tissue that can include bits of fat, hair and teeth — that are common with embryonic stem cells, the researchers said.

"That's one of the biggest issues the FDA will be concerned about when it comes time to approve stem-cell-based therapies," said the University of Pittsburgh's Russell.

But Larry Goldstein, a professor of cellular and molecular medicine at UC San Diego who studies embryonic stem cells, said the absence of tumors might signal a limitation of amniotic stem cells. "It makes me wonder how pluripotent they are," said Goldstein, who was not involved in the study.

Though the cells might prove useful in some circumstances, Goldstein said, they aren't a substitute for embryonic stem cells. "They built a screwdriver here, but I need a wrench," he said.

The technology described in the study is owned by Wake Forest University Baptist Medical Center and controlled by Plureon Corp., a biotech start-up in Winston-Salem.

Atala serves on Plureon's board and directs its scientific advisory panel.

The researchers, whose study was primarily funded by the Joshua Frase Foundation and the Crown Foundation of the March of Dimes, reported they had found similar stem cells in samples of chorionic villi — a part of the placenta sometimes biopsied as an alternative to amniocentesis — and of placentas obtained after birth.

Stem cells could one day be routinely extracted from placentas and stored in case they are needed to create genetically matched tissues during a baby's lifetime, Atala said. Because the cells would be a perfect match, the transplanted tissues would not be rejected.

Amniotic-fluid stem cells could also be used to build a stem cell bank. It would take about 100,000 cell samples to obtain enough genetic diversity to cover 99% of the U.S. population, he said.
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karen.kaplan@latimes.com

About January 2007

This page contains all entries posted to Dr. Werlin's Fertility World in January 2007. They are listed from oldest to newest.

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