Blogs / 80beats

In a pioneering new treatment, doctors created a tailor-made new windpipe for a woman out of donor tissue and the woman’s own stem cells, and say the new, transplanted trachea has been accepted by the woman’s immune system as a natural part of her body without the use of powerful immune-suppressing drugs. Martin Birchall, one of the surgeons, said the transplant showed “the very real potential for adult stem cells and tissue engineering to radically improve their ability to treat patients with serious diseases. We believe this success has proved that we are on the verge of a new age in surgical care” [The New York Times]. Similar treatments could soon be tried on transplants of other hollow organs, like the bowel, bladder, and reproductive tract, he said.

The 30-year-old patient, Claudia Castillo, had failing airways and severe shortness of breath due to a bout with tuberculosis. By March of this year, Castillo’s condition had deteriorated to the point where she was unable to care for her children. Removing a lung was one treatment option, which would have allowed her to live, but seriously impaired her quality of life [Forbes.com]. She opted instead for this experimental treatment, in which doctors took a piece of trachea from an organ donor and transformed it into a structure that now appears native to her body.

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While the nation decides on the fate of Barack Obama and John McCain tomorrow, residents of Michigan will also decide on the fate of thousands of human embryos. They will be voting on Proposition 2, an amendment to the state constitution that would lift a 30-year-old ban on the destruction of human embryos to get stem cells for medical research. Currently, researchers in the state must import embryonic stem cell lines from other states or countries. (Research on embryonic stem cells is legal in Michigan, but not the destruction of embryos.) The nationwide ban on federal funding for most embryonic stem cell research, instituted in 2001, will still hold, although both Obama and McCain have stated they would lift the ban if elected.

Proposition 2 pits the state’s powerful public and private biological research centers against large, conservative Catholic and evangelical populations who oppose destroying embryos, a form of human life [Wall Street Journal]. The proposition is sponsored by the bipartisan group Cure Michigan. Proponents argue embryos in fertility clinics are routinely thrown away, so why not donate them to science [Detroit Free Press]? The U. S. currently has 400,000 frozen embryos in storage, most of which will be discarded. Supporters say embryonic stem cell research could lead to therapies for degenerative diseases like Alzheimer’s and juvenile diabetes, and that lifting the ban would advance the state’s biomedical industry and create thousands of new jobs.

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Scientists have proven that a functional prostate gland can be grown from a single adult stem cell. The glands were grown in mice but the research, by scientists at Genentech in San Francisco, may aid the diagnosis and treatment of prostate cancer in humans. It is the second instance of an entire organ being grown from a single stem cell; the first came in 2006, when scientists grew mammary glands in mice.

The team first found a marker, a protein, that would differentiate prostate stem cells from other cells in the prostate. This marker, C-117, can also be found in the human prostate, they said [Reuters]. Using the new C-117 marker and three previously known markers, the scientists identified stem cells in the prostate of baby mice and transplanted them onto the kidneys of adult mice. Three months later, the researchers removed the kidneys and analyzed the fate of the grafted cells. Of the 97 single-cell transplants, 14 had grown into fully functioning prostates–complete with multiple cell types, characteristic branching structures, and prostate-specific proteins [Technology Review].

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Researchers have found a way to create stem cells from adult liver cells without triggering DNA changes that have caused mutations and tumors in previous studies. Though demonstrated only in mice so far, the result marks another key achievement in the fledgling science of cellular reprogramming. The hope is to create human, embryonic-like stem cells — which can be turned into all the other tissue types of the body — without using eggs or destroying embryos. That freshly derived tissue could then be transplanted into patients to treat various diseases [The Wall Street Journal].

A method of using adult cells to create stem cells was debuted by Japanese researchers in 2006. By using viruses to insert key developmental genes, researchers coaxed human skin cells into an embryonic state, capable of growing into almost any other type of tissue…. But there was a catch: Viruses used to reset the cells tended to fuse with their DNA, leading to unpredictable mutations and cancer. The cells were promising in principle, but couldn’t be used medically [Wired News]. In the new breakthrough, researchers used a different kind of virus to introduce the genes, and found that it didn’t leave behind any damaging genetic code.

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In a discovery that’s being hailed as a leap forward in regenerative medicine, researchers have found a way to transform common pancreatic cells in an adult mouse into the rare, insulin-producing beta cells that are destroyed in type 1 diabetes. Previously, researchers believed that the only way to transmute an adult cell was to first coax it back into stem cell form and then to reprogram it; this new research removes the first step entirely.

The accomplishment raises the tantalizing prospect that patients suffering from not only diabetes but also heart disease, strokes and many other ailments could eventually have some of their cells reprogrammed to cure their afflictions without the need for drugs, transplants or other therapies. “It’s kind of an extreme makeover of a cell,” said [lead researcher] Douglas A. Melton…. “The goal is to create cells that are missing or defective in people. It’s very exciting” [Washington Post].

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Using embryonic stem cells, researchers have created enough red blood cells to fill several test tubes, in a development that could eventually allow for the mass-production of blood and the end of blood donation drives. “We literally generated whole tubes in the lab, from scratch,” said Robert Lanza, chief science officer at Advanced Cell Technologies [Wired News].

The breakthrough raises the prospect of mass-producing supplies of the “universal donor” blood type O-negative, which is prized because it can be safely transfused into any patient, whatever their blood group. This type of blood is in short supply – around 8% of Caucasians have it, and just 0.3% of Asians [New Scientist]. Experts say the method would also help keep pathogens like HIV out of the blood supply, as blood banks would no longer have to screen the blood from thousands of donors.

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In a striking achievement, researchers have taken ordinary skin cells from two elderly women suffering from Lou Gehrig’s disease, also known as amyotrophic lateral sclerosis, and have reprogrammed those cells to act like stem cells, the versatile cells that can grow into almost any kind of specialized cell. Then the researchers programmed the cells to turn into motor neurons, the type of nerve cells that waste away and die as ALS progresses.

The new nerve cells won’t be used in any sort of experimental treatment; instead researchers will look for flaws in these nerve cells to study the disease’s mechanism. “Now we can make limitless supplies of the cells that die in this awful disease. This will allow us to study these neurons, and ALS, in a lab dish, and figure out what’s happening in the disease process,” said [study coauthor] Dr. Kevin Eggan [Reuters]. This is particularly useful for ALS because the nerve cells affected by the disease are in patients’ spinal cords, making it impossible for researchers to take cell samples for study.

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Several medical research institutions are reconsidering the use of five stem cell lines that are approved for federal-funded research by the National Institutes of Health, citing recently discovered problems with the consent forms signed by the patients at fertility clinics who donated their extra embryos to medical research. Now, ethics oversight committees at universities across the United States are questioning which lines should be permissible for research [Nature News].

Stanford and San Francisco-based [California Institute for Regenerative Medicine] — the $3 billion state agency created when California voters approved the sale of bonds to fund embryonic stem cell research — along with Johns Hopkins University have stopped or may stop research on five of the 21 lines that President Bush in August 2001 deemed acceptable for federal funding [San Jose Business Journal]. Researchers had already chafed at the narrow range of genetic diversity available from the 21 lines; this new development is likely to further limit their research options.

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In an experiment that could have applications in treating heart disease and strokes, researchers have taken certain cells from the blood and used them to grow entire networks of blood vessels in mice.

“What’s really significant about our study is that we are using human cells that can be obtained from blood or bone marrow rather than removing and using fully developed blood vessels,” said Harvard’s Joyce Bischoff, who led the study.[Reuters].

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Researchers say they turned a mouse with muscular dystrophy into a mighty mouse by injecting stem cells into its muscles. Just a few weeks after injecting the stem cells, which were taken from the muscles of healthy adult mice, the weak and wasting muscles of the ailing mice were almost completely restored to full strength.

While human trials are still years away, the results offer hope that one day skeletal muscle stem cells from healthy people could be grafted into those with muscle disorders, says Amy Wagers, coauthor of the paper…. People with other kinds of muscle damage could benefit as well, she says. “There are a lot of situations where muscle is degenerating or damaged and you might want to boost its regenerative capacity” [Science News]. 

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