In pig brains, researchers launch a new activity after death

Conventional wisdom tells us that a mammalian brain dies a few minutes after stopping receiving oxygen. But a recent study, published Wednesday in Nature, challenges our current definitions of life and death.

Researchers at the Yale School of Medicine have successfully revived cell activity in the brains of pigs slaughtered for their meat. The brains did not regain consciousness, but the blood vessels resumed functioning and some cells resumed their metabolic activities, including oxygen uptake and carbon dioxide production. The researchers also measured the electrical activity, although it is not a motive that means consciousness.

"This is not a living brain, but a cell-active brain," said neuroscientist Nenad Sestan, who led the study, at The New York Times.

To conduct the experiment, researchers took the brain from 32 pigs four hours after slaughter. In a move that may seem straight out of science fiction, they then connected the organs to a system called BrainEx, which circulated synthetic blood in the brain for six hours in total.

Carrying oxygen and other nutrients, the solution also contained chemicals to block the nerve signals, which served two functions. First, it helped protect cells from spoilage, a process called excitotoxicity. And secondly, as an added precaution, the researchers wanted to eliminate the possibility (very small) that a brain regains consciousness. They were ready to end the experiment and administer anesthesia in case such activity was detected.

As the news coverage has clearly shown, the work is preliminary and does not have a direct impact on medicine. But it offers new possibilities for understanding how to treat patients with massive stroke or other traumatic brain injury.

It also raises troubling ethical questions. Currently, a person is legally dead if they lose any brain function. The ability to revive a brain dead patient could have a significant impact on organ donations. If a person has a heart attack, for example, doctors may face more complex decisions as to whether they should continue to try to revive the patient or whether they should be prepared for the donation. # 39; organs.

Also in the news:

• A new type of gene therapy for infants born without a functioning immune system successfully treated eight babies in a clinical trial conducted at St. Jude's Children's Research Hospital and the University of California at San Francisco ( UCSF), the Benioff Children's Hospital. The treatment uses a modified version of HIV to deliver a gene that restores immunity in infants born with a form of severe combined immunodeficiency, called SCID-X1. Each year, fewer than 100 children, mostly boys, are born with the rare killer disease in the United States. Since the 1990s, bone marrow transplantation has been the standard treatment for SCID, but it requires donor matching, monthly infusions throughout life, and patient exposure to a risk of leukemia. The new St. Jude treatment should be permanent and have a lower risk of blood cancer. The results of the study were published in the New England Journal of Medicine on Wednesday. Since the document was prepared for publication, two other infants have also successfully undergone the new treatment, and St. Jude has signed a licensing agreement with the small gene therapy company Mustang Bio in hopes of commercializing the procedure. (NPR)

• Astrochemists announced this week the observation of the oldest type of molecule in our universe – helium hydride – in a 600-year-old planetary nebula about 3,000 light-years away. First born when the hot ions produced during the Big Bang began to cool down and form bonds, helium hydride was synthesized in the lab there is close to one century, but its detection in the wild has proved difficult to reach, letting some researchers believe that it had been lost. space. According to an article published Wednesday in the journal Nature, the team has detected the characteristic frequencies of light emitted by the molecule with the help of a specialized laboratory integrated into a Boeing 747SP, called Stratospheric Observatory for infrared astronomy. Flying at an altitude of 45,000 feet, the in-flight spectrometer could detect light emissions that would be masked by ground-based detectors by the water vapor of the Earth's atmosphere. The emission of light associated with helium hydride came from a young planetary nebula known as NGC 7027 with a warm and dense central star. "The lack of evidence of the very existence of helium hydride in the local universe has challenged our understanding of early universe chemistry," Rolf said. Güsten, astronomer at the Max Planck Radioastronomy Institute, and the main author of the study, says the guardian. "The detection reported here resolves such doubts." (The Guardian)

• A new study suggests that even in the confines of a seemingly immaculate Pyrenean mountain range, microplastics – many of them – blow in the wind. In a weather station in southwestern France, 4500 feet above sea level and 100 km from the nearest town, researchers collected an average of more than 350 pieces of plastic a day on an area of ​​one square meter hardly. "The numbers are incredible," said Steve Allen, who contributed to the work. The collected plastic – used packaging materials, plastic bags, fabric fibers and similar materials – would come from cities up to hundreds of kilometers away. Assuming that such particles are raining at comparable rates in other parts of the country, France could receive about 2,000 tonnes of microplastics a year. Although it is known that tiny particles are ubiquitous in the soil, oceans and freshwater bodies, Allen considers windmill microplastics as "a whole new [type of] "Pollution" that could present new threats: they can probably be inhaled by humans, he says, and once in the atmosphere, they are virtually impossible to clean. (NPR)

• For thousands of years, the Cofan people of Ecuador have settled in the rainforest, relying on its resources for food, housing and recreation. drugs. According to the United Nations Declaration on the Rights of Indigenous Peoples, their ability to pursue this way of life should be protected. However, since their territory is now in a national park, the Cofan are actually lacking autonomy on their land. While their community is facing increasing threats of illegal mining, logging and poaching, both themselves and other indigenous peoples are acting. Working with various nongovernmental and indigenous organizations, Cofan began using GPS devices, a drone and hidden cameras, to monitor and map the forest in order to use the data collected to apply for an official title deed . their land. Already in 2018, they were gathering enough evidence to prove that minors benefiting from government legal concessions were operating outside authorized areas, resulting in water pollution and other damage to the environment. "Today, we feel stronger and more powerful and able to say that the Cofan are warriors," said Edison Lucitante, president of the Sinangoe community. "We won the case. We beat the government. We will continue. "(Pacific Standard)

• As political and trade tensions continue to reign between China and the administration of US President Donald J. Trump, the research community and academia are increasingly affected by the fallout. In some cases, American universities have been encouraged to take punitive measures against foreign scientists described by Nature magazine as "unfulfilled rules" related to projects funded by the National Institutes of Health. The sanctions are being implemented in response to a letter from NIH chief Francis Collins earlier this year calling on US universities to monitor "foreign entities" that interfere in NIH-funded research. Other federal agencies have reviewed and updated the rules governing interactions with foreign researchers, and the State Department has revised the rules for issuing visas to Chinese students wishing to undertake higher education at the university. United States – and even issuing visas to Chinese nationals wishing to pursue scientific studies. conferences have been stalled or slowed in recent months. The movements sparked a letter to Nature last month from groups representing Sino-US researchers, claiming that Chinese-born scientists working in the United States ran a real danger of "scape gating, stereotyping, and profiling." racial". (Nature)

• Finally, the field of archeology, relatively sleepy, is still reeling from the #MeToo controversy that erupted last Thursday at an annual professional meeting in New Mexico and continued. this week with angry letters and missing leadership charges. David Yesner, a former archaeologist from the University of Alaska at Anchorage (UAA), has retired. His recent retirement has been accompanied by multiple accusations of "sex discrimination, assault and harassment," according to Science magazine. After an investigation report commissioned by the university and released last month revealed that nine of the charges were credible, Yasner was banned from the UAA campus and when he was not in charge. he attended the meeting of the Society for American Archeology in Albuquerque, to which he attended by some of his accusers – the discord ensued. Yesner was eventually expelled from the proceedings, not by the SAA organizers, but by a freelance journalist who was scheduled to speak at the sexual harassment conference. The initial response of the SAA: ban the journalist following the meeting. A series of open letters, public resignations and Disputes on Twitter followed, and while SAA had begun a more serious effort of apology and self-reflection in the mid-week of the week, critics suggested that the organization was still scolding at the details what happened at the conference – what he would do to reform himself to go from the front. (Science, KTVA)