Lab-Grown Embryos Mix Human And Monkey Cells For The First Time

By slipping human stem cells into the embryos of other animals, we might someday grow new organs for people with faltering hearts or kidneys. In a step toward that goal, researchers have created the first embryos with a mixture of human and monkey cells. These chimeras could help scientists hone techniques for growing human tissue in species better suited for transplants, such as pigs.

“The paper is a landmark in the stem cell and interspecies chimera fields,” says stem cell biologist Alejandro De Los Angeles of Yale University. The findings hint at mechanisms by which cells of one species can adjust to survive in the embryo of another, adds Daniel Garry, a stem cell biologist at the University of Minnesota (UM), Twin Cities.

In 2017, researchers reported growing pancreases from mouse stem cells inserted into rat embryos. Transplanting the organs into mice with diabetes eliminated the disease. But cells from more distantly related species, such as pigs and humans, haven’t gotten along as well. That same year, developmental biologist Juan Carlos Izpisúa Belmonte of the Salk Institute for Biological Studies and colleagues reported injecting human stem cells into pig embryos. After the embryos had developed in surrogate mother pigs for 3 to 4 weeks, only about one in 100,000 of their cells were human.

The pig study used human skin cells that had been reprogrammed into stem cells. But so-called extended pluripotent stem (EPS) cells, made by exposing stem cells to a certain molecular cocktail, can spawn a greater variety of tissues. In the new study, Izpisúa Belmonte, reproductive biologist Weizhi Ji of Kunming University of Science and Technology, and colleagues tested those more capable cells in a closer human relative—cynomolgus monkeys. They inserted 25 human EPS cells into each of 132 monkey embryos and reared the chimeras in culture dishes for up to 20 days.

The team reports today in Cell that the human cells showed staying power: After 13 days, they were still present in about one-third of the chimeras. The human cells seemed to integrate with the monkey cells and had begun to specialize into cell types that would develop into different organs.

By analyzing gene activity, the researchers identified molecular pathways that were switched on or turned up in the chimeras, possibly promoting integration between human and monkey cells. Izpisúa Belmonte says manipulating some of those pathways may help human cells survive in embryos of species “more appropriate for regenerative medicine.”

Still, the human and monkey cells didn’t quite mesh, notes UM stem cell biologist Andrew Crane. The human cells often stuck together, making him wonder whether there’s “another barrier that we aren’t seeing” that could prevent human cells from thriving if the embryos were to develop further.

In the United States, federal funding cannot be used to create certain types of chimeras, including early nonhuman primate embryos containing human stem cells. The new study was performed in China and funded by Chinese government sources, a Spanish university, and a U.S. foundation. Bioethicist Karen Maschke of the Hastings Center in New York says she is satisfied that the work, which passed layers of institutional review and drew on advice from two independent bioethicists, was performed responsibly.

Human-monkey chimeras do raise a worry, addressed in a report released last week by the National Academies of Sciences, Engineering, and Medicine (p. 218): that human nerve cells might enter animals’ brains and alter their mental capabilities. But that concern is moot for the chimeras in this study because they don’t have a nervous system. They “can’t experience pain and aren’t conscious,” says bioethicist Katrien Devolder of the University of Oxford. “If the human-monkey chimeras were allowed to develop further,” she says, “that would be a very different story.”

Source: Science Magazine

COVID-19 Cases Recorded In Antarctica For First Time – Isolated Continent Reportedly Registers First Infections After 36 Chileans Fall Ill At Research Base

Antarctica, once the only continent not to be affected by the coronavirus pandemic, has reportedly recorded its first cases. The 36 new infections are among people stationed at a Chilean research base and include 26 members of the Chilean army and 10 maintenance workers.

Spanish-language media reported the outbreak at the General Bernardo O’Higgins Riquelme research base on Monday.

In a statement, the Chilean army said: “Thanks to the timely preventive action … it was possible to relieve said personnel, who, after being subjected to a medical control and the administration of a PCR test … turned out to be positive for Covid-19,” according to Newsweek. It reported that three crew members on a ship providing support to the base have also tested positive since returning from their mission to Antarctica.

The 36 individuals who tested positive have since been evacuated to the city of Punta Arenas in Chile, where they are reported to be under isolation and in good condition.

General Bernardo O’Higgins Riquelme is one of 13 Chilean bases on the island, the ABC reports.

Trying to keep the virus at bay in Antarctica has come at a cost. All major research projects in the Antarctic have been halted. As a result, research by scientists around the world has been interrupted.

While the continent has no permanent residents, it 1,000 researchers and other visitors stayed on the island over winter, according to the Associated Press.

In March, as the world locked down in response to Covid’s rapid spread, the Antarctic programs agreed the pandemic could become a major disaster. With the world’s strongest winds and coldest temperatures, the continent roughly the size of the United States and Mexico is already dangerous for workers at its 40 year-round bases.

Source: The Guardian

Facebook Accused Of Watching Instagram Users Through Their Phone Cameras

Facebook Inc. is again being sued for allegedly spying on Instagram users, this time through the unauthorized use of their mobile phone cameras.

The lawsuit springs from media reports in July that the photo-sharing app appeared to be accessing iPhone cameras even when they weren’t actively being used.

Facebook denied the reports and blamed a bug, which it said it was correcting, for triggering what it described as false notifications that Instagram was accessing iPhone cameras.

In the complaint filed Thursday in federal court in San Francisco, New Jersey Instagram user Brittany Conditi contends the app’s use of the camera is intentional and done for the purpose of collecting “lucrative and valuable data on its users that it would not otherwise have access to.”

By “obtaining extremely private and intimate personal data on their users, including in the privacy of their own homes,” Instagram and Facebook are able to collect “valuable insights and market research,” according to the complaint.

Facebook declined to comment.

Source: Bloomberg

Memories Can Be Injected and Survive Amputation and Metamorphosis

The study of memory has always been one of the stranger outposts of science. In the 1950s, an unknown psychology professor at the University of Michigan named James McConnell made headlines—and eventually became something of a celebrity—with a series of experiments on freshwater flatworms called planaria. These worms fascinated McConnell not only because they had, as he wrote, a “true synaptic type of nervous system” but also because they had “enormous powers of regeneration…under the best conditions one may cut [the worm] into as many as 50 pieces” with each section regenerating “into an intact, fully-functioning organism.” 

In an early experiment, McConnell trained the worms à la Pavlov by pairing an electric shock with flashing lights. Eventually, the worms recoiled to the light alone. Then something interesting happened when he cut the worms in half. The head of one half of the worm grew a tail and, understandably, retained the memory of its training. Surprisingly, however, the tail, which grew a head and a brain, also retained the memory of its training. If a headless worm can regrow a memory, then where is the memory stored, McConnell wondered. And, if a memory can regenerate, could he transfer it? 

Shockingly, McConnell reported that cannibalizing trained worms induced learning in untrained planaria. In other experiments, he trained planaria to run through mazes and even developed a technique for extracting RNA from trained worms in order to inject it into untrained worms in an effort to transmit memories from one animal to another. Eventually, after his retirement in 1988, McConnell faded from view, and his work was relegated to the sidebars of textbooks as a curious but cautionary tale. Many scientists simply assumed that invertebrates like planaria couldn’t be trained, making the dismissal of McConnell’s work easy. McConnell also published some of his studies in his own journal, The Worm Runner’s Digest, alongside sci-fi humor and cartoons. As a result, there wasn’t a lot of interest in attempting to replicate his findings.

David Glanzman, a neurobiologist at the University of California, Los Angeles, has another promising research program that recently struck a chord reminiscent of McConnell’s memory experiments—although, instead of planaria, Glanzman’s lab works mostly with aplysia, the darling mollusk of neuroscience on account of its relatively simple nervous system. (Also known as “sea hares,” aplysia are giant, inky sea slugs that swim with undulating, ruffled wings.)

Source: Nautilus

For the first time since the Great Depression, a majority of young adults (ages 18-29) in the U.S. now live with their parents — Report

As COVID-19 swept the country this year, millions of young adults retreated to familiar territory: living at home with mom and dad.

A majority of young Americans ages 18 to 29 are now living with at least one of their parents, according to a Pew Research Center analysis of Current Population Survey data. About 52% of this age group, 26.6 million people in total, were living with their parents in July, compared to 47% at the same time last year. This number surpassed the previous record of 48%, which was set in 1940, during the Great Depression.

Since the proportion of 18 to 29 year olds living at home hit a low of 29% in 1960, the number has risen over the decades, jumping to 36% in 1990, to 38% in 2000 and 44% in 2010. However, the increase this year is notably sharp, and tracks with the trajectory of the pandemic; while about 46% or 47% of young adults lived at home through 2019, in 2020 the number jumped to 49% in March, 51% in April and 52% from May through July.

Source: Time

2nd person cured of HIV after 30 months virus-free, thanks to stem cell transplant

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The cells without the CCR5 gene were part of a bone marrow transplant, which the person was undergoing as a treatment for Hodgkin lymphoma.

Following the transplant, and at 30 months after the person ceased antiretroviral therapy, doctors confirmed that the HIV viral load remained undetectable in blood samples.

This finding means that whatever traces of the virus’s genetic material might still be in the system, they are so-called fossil traces, meaning that they cannot lead to further replication of the virus.

The specialists confirmed that HIV also remained undetectable in samples of cerebrospinal fluid, semen, intestinal tissue, and lymphoid tissue.

Source: MedicalNewsToday