China will begin trialling the use of embryonic stem-cells (ES) to treat Parkinson’s disease and macular degeneration, in a move that has met with criticism from international experts.
The trials, which come in the wake of new stem-cell regulations introduced in China in 2015, will test the efficacy of injecting ES-derived cells into damaged areas of the brain and eyes.
In one trial, ES-derived neuronal-precursor cells will be injected into the areas of the brain affected by Parkinson’s disease in attempt to regenerate dopamine-producing tissue. In another trial, the ES-derived retinal cells will be injected into eyes of people with age related macular degeneration. It is believed that the retinal cells may be able to replace cells damaged as a result of epithelial tissue degeneration.
“It will be a major new direction for China,” Pei Xuetao, a stem-cell scientist at the Beijing Institute of Transfusion Medicine who is on the central-government committee that approved the trials, told Nature.
Other researchers who work on Parkinson’s disease, however, worry that the trials might be misguided.
Jeanne Loring, a stem-cell biologist at the Scripps Research Institute in La Jolla, California, who is also planning stem-cell trials for Parkinson’s, is concerned that the Chinese trials use neural precursors and not ES-cell-derived cells that have fully committed to becoming dopamine-producing cells. Precursor cells can turn into other kinds of neurons, and could accumulate dangerous mutations during their many divisions, says Loring. “Not knowing what the cells will become is troubling.”
Lorenz Studer, a stem-cell biologist at the Memorial Sloan Kettering Cancer Center in New York City, says that “support is not very strong” for the use of precursor cells. “I am somewhat surprised and concerned, as I have not seen any peer-reviewed preclinical data on this approach,” he told Nature.
Saturday, June 3, 2017
Now that President Donald Trump has backed out of the Paris Climate Change agreement, employment prospects for bioethicists may pick up. Let me explain
The boundaries of bioethics are very elastic, and on some maps they take in care for the natural environment. I would predict that in the measure that scientists lose faith in a political solution to global warming, some will back geoengineering projects to cool the planet.
These include tactics such as injecting aerosols into the upper atmosphere, dumping iron filings into the sea to promote algal blooms, and machines to capture carbon dioxide. These involve significant risk and place great power in the calculations of technocrats. They need to be studied very carefully. As University of Chicago climate scientist Raymond Pierrehumbert said a few years ago, “I see lots [of geoengineering ideas] that are feasible but they all terrify me.”
A 2010 conference on the ethics of climate intervention at Asilomar, in California, addressed some of these issues using principles drawn from the famous Belmont principles of autonomy, beneficence, non-malificence and justice. And who knows more about these than bioethicists? Dust off those resumés.
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