Scientists move hands closer to ‘midnight’
It’s now two-and-a-half minutes to “midnight,” according to the Bulletin of Atomic Scientists, which warned Thursday that the end of humanity may be nigh.
The group behind the famed Doomsday Clock announced at a news conference that it was adjusting the countdown to the End of it All by moving the hands 30 seconds closer to midnight — the closest the clock has been to Doomsday since 1953, after the United States tested its first thermonuclear device, followed months later by the Soviet Union’s hydrogen bomb test.
In announcing that the Doomsday Clock was moving 30 seconds closer to the end of humanity, the group noted that in 2016, “the global security landscape darkened as the international community failed to come effectively to grips with humanity’s most pressing existential threats, nuclear weapons and climate change.”
But the organization also cited the election of Donald Trump in changing the symbolic clock.
“Making matters worse, the United States now has a president who has promised to impede progress on both of those fronts,” theoretical physicist Lawrence M. Krauss and retired Rear Adm. David Titley wrote in a New York Times op-ed on behalf of the Bulletin of the Atomic Scientist. “Never before has the Bulletin decided to advance the clock largely because of the statements of a single person. But when that person is the new president of the United States, his words matter.”
NEW YORK — Scientists have grown human cells inside pig embryos, a very early step toward the goal of growing livers and other human organs in animals to transplant into people.
The cells made up just a tiny part of each embryo, and the embryos were grown for only a few weeks, researchers reported Thursday.
Such human-animal research has raised ethical concerns. The U.S. government suspended taxpayer funding of experiments in 2015. The new work, done in California and Spain, was paid for by private foundations.
Any growing of human organs in pigs is “far away,” said Juan Carlos Izpisua Belmonte of the Salk Institute in La Jolla, California, an author of the paper in the journal Cell.
He said the new research is “just a very early step toward the goal.”
Even before that is achieved, he said, putting human cells in animals could pay off for studies of how genetic diseases develop and for screening potential drugs.
Animals with cells from different species are called chimeras (ky-MEER’-ehz). Such mixing has been done before with mice and rats. Larger animals like pigs would be needed to make humansized organs. That could help ease the shortage of human donors for transplants.
The Salk team is working on making humanized pancreases, hearts and livers in pigs. The animals would grow those organs in place of their own, and they’d be euthanized before the organ is removed.
Most of the organ cells would be human. By injecting pig embryos with stem cells from the person who will get the transplant, the problem of rejection should be minimized, said another Salk researcher, Jun Wu.
Daniel Garry of the University of Minnesota, who is working on chimeras but didn’t participate in the new work, called the Cell paper “an exciting initial step for this entire field.”