A scientific paper expands on social media reports of sudden onset of periods, spotting and other menstrual peculiarities during last summer’s protests in Portland, Ore.At some point last summer, there were just too many reports of protesters who had experienced abnormal menstrual cycles after being exposed to tear gas for Britta Torgrimson-Ojerio, a nurse researcher at the Kaiser Permanente Center for Health Research in Portland, to dismiss them as coincidence.A preschool teacher told Oregon Public Broadasting that if she inhaled a significant amount of gas at night, she’d get her period the next morning. Other Portland residents shared stories of periods that lasted for weeks and of unusual spotting. Transgender men described sudden periods that defied hormones that had kept menstruation at bay for months or years.Dr. Torgrimson-Ojerio decided she would try to figure out whether these anecdotes were outliers or representative of a more common phenomenon. She surveyed around 2,200 adults who said they had been exposed to tear gas in Portland last summer. In a study published this week in the journal BMC Public Health, she reported that 899 of them — more than 54 percent of the respondents who potentially menstruate — said they had experienced abnormal menstrual cycles.“Even though we cannot say anything scientifically definitive about these chemical agents and a causal relationship to menstrual irregularities,” Dr. Torgrimson-Ojerio said, “we can definitively say that in our study most people who had menstrual cycles or a uterus reported menstrual irregularities after reporting exposure to tear gas.”Downstream effects, like the impact on fertility, are not known, but “this is our call to action to ask our scientific community to turn their eye to this issue,” she said.Dr. Torgrimson-Ojerio was also interested in whether people had experienced other problems more than a few hours after being exposed to tear gas. She found that 80 percent of survey participants had, with difficulty breathing being among the most prevalent complaints.Kira Taylor, a professor of epidemiology and population health at the University of Louisville School of Public Health and Information Sciences who is conducting a similar study, said that Dr. Torgrimson-Ojerio’s study provided “some of the first solid evidence” that tear gas might be linked to menstrual abnormalities. It is also “the first study to document the longer-term effects of tear gas exposure in a large population,” she said.Sven-Eric Jordt, a professor of anesthesiology, pharmacology and cancer biology at the Duke University School of Medicine, who was not involved in the study, applauded the work.A tear gas canister striking a barrier in Portland in July.Mason Trinca for The New York TimesMost of the research that police agencies and the government rely on to inform them about tear gas safety “are outdated, often 50 to 70 years old, and don’t measure up to modern toxicological approaches,” he said. “Most of these studies were conducted in young healthy men at the time, either police or military, and not in women, or in a general civilian population representing protesters.”Dr. Torgrimson-Ojerio and her colleagues recruited survey participants through social media and links on the websites of The Oregonian and the Oregon Health Authority in July and August.The researchers asked participants to explain precisely how their periods had been affected after exposure to tear gas. Increased cramps, unusual spotting and uncharacteristically intense or long bleeding were the most common reactions. A number of people who don’t usually have periods because of hormone therapy or age reported unexpected bleeding and spotting, Dr. Torgrimson-Ojerio said.This study has limitations. It is not a random sample.“It is possible that people who feel that their health was damaged by tear gas might have been more likely to respond than people who were also exposed, yet did not feel such harmful effects,” Dr. Taylor said. “This means that some of the numbers might be exaggerated.”Given that subjects were permitted to participate anonymously, researchers could not verify their accounts.A spent canister of CS gas that was fired during a protest at the Immigration and Customs Enforcement building in Portland in January.Alisha Jucevic for The New York TimesNor can the study answer how or why tear gas might be contributing to menstrual irregularities or to what extent other factors are also involved. The authors acknowledge that the high levels of stress and anxiety among protesters, for example, could also have contributed to the physical response.“It is possible that pain, stress, dehydration and exertion play a role,” Dr. Jordt said. Alternatively, tear gas may act as an “endocrine disrupter,” interfering with normal hormonal function.“The tear gas agent CS, sometimes used by police, is a chlorinated chemical compound and produces additional chlorinated byproducts when burned in the canisters used by the police,” he said. “Exposure to chlorinated chemicals can affect menstrual health.”Alexander Samuel, a molecular biologist in France, has been investigating similar questions since French protesters began reporting menstrual irregularities.He mentioned two additional areas for exploration: whether tear gas is metabolized into cyanide, which may cause heavy menstrual bleeding, and the role a traumatic event may play in altering menstrual cycles.Suspicions about tear gas and menstruation first came up more than a decade ago, during the Arab Spring protests, Dr. Jordt noted.In 2011, Chile also banned the use of tear gas after a study suggested that CS gas could cause miscarriages and harm young children. Three days later, the Chilean police lifted the ban, insisting that the type of tear gas they used was perfectly safe.

Some celebrity vaccine endorsements have delighted social media users. But epidemiologists say there isn’t much evidence proving that they boost vaccine uptake.Pelé, Dolly Parton and the Dalai Lama have little in common apart from this: Over a few days in March, they became the latest celebrity case studies for the health benefits of Covid-19 vaccines.“I just want to say to all of you cowards out there: Don’t be such a chicken squat,” Ms. Parton, 75, said in a video that she posted on Twitter after receiving her vaccine in Tennessee. “Get out there and get your shot.”This is hardly the first time public figures have thrown their popularity behind an effort to change the behavior of ordinary people. In medicine, celebrity endorsements tend to echo or reinforce messages that health authorities are trying to publicize, whether it’s getting a vaccine, or other medical treatment. In 18th-century Russia, Catherine the Great was inoculated against smallpox as part of her campaign to promote the nationwide rollout of the procedure. Almost 200 years later, backstage at “The Ed Sullivan Show,” Elvis Presley received the polio vaccine in an effort to help reach at-risk teenagers.But do the star-studded endorsements really work? Not necessarily. Epidemiologists say there are plenty of caveats and potential pitfalls — and little scientific evidence to prove that the endorsements actually boost vaccine uptake.“Very few people actually do give the weight of expertise, for better or worse, to celebrities,” said René F. Najera, an epidemiologist and the editor of the History of Vaccines website, a project of the College of Physicians of Philadelphia.Elvis Presley received the polio vaccine backstage at the “The Ed Sullivan Show” in 1956.CBS Photo Archive/Getty Images“There’s some shift there now with social media and social influence in the younger age groups,” he added. “But for the most part, we still listen more to our peers than to some figurehead.”As vaccination campaigns accelerate around the world, watching high-profile endorsements has become one of the latest — and among the weirdest — online rituals of the Covid era.To help track the phenomenon, New York Magazine over the winter kept a running list of newly vaccinated celebrities that includes Christie Brinkley (“piece of cake”), Whoopi Goldberg (“I didn’t feel it”) and Mandy Patinkin (“One of the few benefits of being old”). Journalists in India have done the same for Bollywood film stars.In Europe, pictures of male politicians getting their shots while shirtless have generated a bunch of memes. An epidemiologist in Oregon, Dr. Esther Choo, joked on Twitter that the French health minister, Olivier Véran, was carrying out a public-relations campaign that she called “Operation Smolder.”Such posts are notable because they instantly allow millions of people to see the raw mechanics of immunization — needles and all — at a time when skepticism toward Covid vaccines has been stubbornly persistent in the United States and beyond. The rapid-fire testimonials by Pelé, Ms. Parton and the Dalai Lama in March, for example, collectively reached more than 30 million followers and prompted hundreds of thousands of engagements across Twitter, Instagram and YouTube. In April, the singer Ciara hosted a star-studded NBC special meant to promote vaccinations, with appearances by former President Barack Obama and his wife, Michelle Obama, as well as Lin-Manuel Miranda, Jennifer Hudson, Matthew McConaughey and others.“These kind of endorsements might be especially important if trust in government/official sources is quite low,” Tracy Epton, a psychologist at the University of Manchester in Britain who has studied public health interventions during the coronavirus pandemic, said in an email.That was the case in the 1950s, when Elvis Presley agreed to receive the polio vaccine to help the National Foundation for Infantile Paralysis reach a demographic — teenagers — that was “difficult to educate and inspire through traditional means,” said Stephen E. Mawdsley, a lecturer in modern American history at the University of Bristol in Britain.“I think Elvis helped to make getting vaccinated seem ‘cool’ and not just the responsible thing to do,” Dr. Mawdsley said.There is some evidence that celebrity endorsements of a given medical behavior can have concrete results. After Katie Couric had a colonoscopy live on the “Today” show in 2000, for example, the number of colorectal screenings in the United States soared for about nine months.And in Indonesia, researchers found in a pre-coronavirus experiment that when 46 celebrities agreed to tweet or retweet pro-immunization messages, their posts were more popular than similar ones from noncelebrities. That was especially true when the celebrities delivered the message in their own voices, rather than citing someone else, researchers found. “Their voice matters,” said Vivi Alatas, an economist in Indonesia and a co-author of that study. “It’s not just their ability to reach followers.”For the most part, though, the science linking celebrity endorsements to behavioral change is tenuous.One reason is that people generally consider those within their own personal networks, not celebrities, the best sources of advice about changing their own behavior, Dr. Najera said.He cited a 2018 study that found few gun owners in the United States rated celebrities as effective communicators about safe gun storage. The owners were far more likely to trust law enforcement officers, active-duty military personnel, hunting or outdoor groups, and family members.From left, Arsenio Hall, Danny Trejo and Magic Johnson got their vaccines together in Los Angeles in March.Pool photo by Gina FerazziDr. Najera and other researchers have been convening focus groups of Americans to find out what has prompted them to agree — or not — to be vaccinated against Covid-19. He said the primary finding so far was that rates of uptake or hesitancy often corresponded to vaccine behavior among a given person’s racial, ethnic or socioeconomic peer group.Ho Phi Huynh, a professor of psychology at Texas A&M University-San Antonio, said that vaccine endorsements from celebrities tended to have a “spectrum of effect” because the degree of star admiration varies so much from fan to fan. Some see a celebrity merely as entertainment, Dr. Huynh said, while others form attachments to them that may compensate for a lack of authentic relationships in their own lives.“So going back to Dolly, if people perceive her to be a ‘typical liberal’ celebrity, there might be little influence for a large faction of the country,” he said.In Indonesia this winter, it took only a few hours for a mega-celebrity to undercut his own vaccine endorsement.The government had chosen the entertainer Raffi Ahmad, 34, to be among the first in the country to receive a Covid shot in January. “Don’t be afraid of vaccines,” he told his Instagram followers, who numbered nearly 50 million at the time, almost a fifth of the country’s population.That night, he was spotted partying without a mask, and accused of breaking the public’s trust.“Please you can do better than this,” Sinna Sherina Munaf, an Indonesian musician, told Mr. Ahmad and her nearly 11 million followers on Twitter. “Your followers are counting on you.”

SharecloseShare pageCopy linkAbout sharingimage copyrightGetty ImagesAs several countries see a devastating resurgence in Covid cases, one tiny Asian island has emerged as the best place to ride out the global pandemic.This week, Singapore topped the Bloomberg Covid Resilience Ranking, knocking out New Zealand which has ruled the chart for months. The list considers factors ranging from Covid case numbers to freedom of movement.Bloomberg cited Singapore’s efficient vaccination programme compared to the slow rollout in New Zealand as the chief reason for the change in position.So what’s it like to live in the best place in the world during these uncertain Covid times? And is it really all that it’s cracked up to be?A near-normal life and deep dissonanceOK, it’s mostly true. Life in Singapore can be pretty good – though I say this with some big caveats.In recent months, apart from small outbreaks that have been swiftly quashed, there have been nearly zero daily community cases – though just this week several new cases emerged and restrictions were promptly tightened.Strict travel rules and border security have meant that imported cases are generally stopped in their tracks, with arrivals whisked away to isolation immediately.Apart from a two month “circuit-breaker” early last year, we’ve never had to go into lockdown again. Life is near-normal: I can see my family anytime or meet friends for dinner at a restaurant, though we can’t be more than eight people. Masks are mandatory everywhere, even outdoors, though you can take them off while exercising or eating.image copyrightGetty Imagesimage copyrightGetty ImagesMany of us are back at work in a socially-distanced office, and you can catch a movie, watch a concert, or go shopping – as long as you wear your mask and check in on a contact tracing app. Schools and childcare centres are open, and on the weekend I can take my children anywhere – though many venues have reduced capacity to ensure social distancing, so planning for the weekend is much like preparing for a military exercise (I’m the hapless soldier, my kids are the generals).image copyrightGetty ImagesAbout 15% of our population has been fully vaccinated since the start of the year. This statistic is partly due to a small base – there’s only about six million of us – but also because of a well-run rollout, high trust in the government, and dwindling vaccine hesitancy.So we’re safe, and doing well – mandatory mask wearing, aggressive contact tracing, and prolonged restrictions on travel and large gatherings have all helped, as does the fact that we’re an island with easily-controlled borders, large financial reserves, and a ruthlessly efficient system.image copyrightGetty ImagesBut at the same time, there’s a deep dissonance in the idea that we’re the best place to live right now.Many in Singapore enjoy freedom of movement, but that’s not the case for the hundreds of thousands of migrant workers who are still mostly confined to their workplaces and dormitories, following mass outbreaks last year due to cramped and unsanitary living conditions.They have to seek permission from their employers if they want to leave their dorms, and mostly socialise in government-approved recreation centres.How a pandemic exposed Singapore’s inequalitiesHalf of Singapore’s migrant workers were Covid-positiveAll this is necessary to protect the rest of the country as there is a “real and significant” risk of another outbreak in their community, the government has argued. This is not untrue, given that many workers continue to live in more crowded housing than most Singaporeans, even after efforts to improve their accommodation.But it also underscores the bitter fact that for all its talk of equality, Singapore still remains a deeply segregated society.This is “shameful and discriminatory”, says migrant rights activist Jolovan Wham. “Because the migrant workers lack political power, it somehow becomes socially acceptable that they bear the brunt of our policy failures.”New Zealand may also be near the top of the Covid Resilience list, but it did not trample on people’s rights. It’s not just about the result, but the means of how we get there.”image copyrightGetty ImagesThe pandemic also continues to leave its scars on the underprivileged and low-income families. The government has ploughed millions of dollars into propping up the economy and helping needy families, and the unemployment rate has remained low.But the figures don’t tell the full story. Some workers have seen pay cuts, and many of those who lost their jobs have found new ones in the gig economy as food deliverymen or drivers.”It’s precarious, and the feeling of not knowing how much you can earn that day, that can be very stressful. They’re easily replaceable too. So it’s that lack of social security,” says social worker Patricia Wee.This stress can then go on to impact families in “insidious ways”, she adds. Cases of family violence, for instance, have been increasing, even after lockdown.A gilded cageEven for those of us who enjoy the privileges of freedom and a stable income, there are some downsides.The little privacy that we had before the pandemic in this highly-surveilled state has diminished even further. We’ve come to accept that everywhere we go, we have to use an app or carry a token that traces our whereabouts and the people we come in contact with, though the government says the data is anonymised.Covid-19 has seen a rush into further surveillance without much public debate. Many agree with the government’s argument that it’s necessary in a crisis, but some have warned of potential misuse of such a massive harvest of data. When the government recently admitted it allowed the police to use this data for purposes other than contact tracing, despite earlier privacy assurances, this lack of transparency angered some.Many are also chafing in what’s turned out to be a gilded cage, thanks to strict quarantine rules in Singapore and elsewhere which have ruled out easy travel for now. It’s meant that many of us still cannot see in person our loved ones in other countries.image copyrightGetty ImagesLiving in a crowded city-state with no hinterland, many in Singapore are used to travelling abroad, even if it’s just a weekend daytrip to a nearby Indonesian island or to neighbouring Malaysia’s border towns. This is no longer possible, so tens of thousands have gone on cruises to nowhere, while hotels are booked up for “staycations” . Motorcycle and car enthusiasts, used to racing the tracks and highways of Malaysia, have been zooming in endless loops around the island. News that Singapore is opening up a travel bubble with Hong Kong, after a failed attempt last year, was met with joy – then a sense of fatalism after community cases were reported in both cities this week.’Survivor’s guilt’It’s hard to complain about boredom though, given how the virus is still ravaging some parts of the world. Some of us, like writer Sudhir Thomas Vadaketh who has family in India which is seeing a devastating second wave, are experiencing something akin to “survivor’s guilt” as they watch loved ones suffer from afar.”It just feels weird that the situation in some countries on this planet is literally hell, while here we are looking forward to the travel bubble. It almost feels immoral that we are doing so well and enjoying our lives while we’ve been closed off, and other countries are doing so badly,” he says.”Singapore is a city that has grown rich off the back of globalisation. Given our connectivity and nature of economic development, I feel that we have a greater moral responsibility [to care about other countries].”image copyrightGetty ImagesMany in Singapore would say that, for now, we are just grateful and relieved to weather a dangerous global pandemic in this safe little bubble.But it will eventually pop. The Singapore government has repeatedly stressed that the country has to reopen for the sake of economic survival, and has already begun easing restrictions for travellers from some places like mainland China and Australia.Singapore will fully rejoin the rest of the world one day – and that will then be our true test of Covid resilience.

Real scalpels, artificial intelligence — what could go wrong?Sitting on a stool several feet from a long-armed robot, Dr. Danyal Fer wrapped his fingers around two metal handles near his chest.As he moved the handles — up and down, left and right — the robot mimicked each small motion with its own two arms. Then, when he pinched his thumb and forefinger together, one of the robot’s tiny claws did much the same. This is how surgeons like Dr. Fer have long used robots when operating on patients. They can remove a prostate from a patient while sitting at a computer console across the room.But after this brief demonstration, Dr. Fer and his fellow researchers at the University of California, Berkeley, showed how they hope to advance the state of the art. Dr. Fer let go of the handles, and a new kind of computer software took over. As he and the other researchers looked on, the robot started to move entirely on its own.With one claw, the machine lifted a tiny plastic ring from an equally tiny peg on the table, passed the ring from one claw to the other, moved it across the table and gingerly hooked it onto a new peg. Then the robot did the same with several more rings, completing the task as quickly as it had when guided by Dr. Fer.The training exercise was originally designed for humans; moving the rings from peg to peg is how surgeons learn to operate robots like the one in Berkeley. Now, an automated robot performing the test can match or even exceed a human in dexterity, precision and speed, according to a new research paper from the Berkeley team.The project is a part of a much wider effort to bring artificial intelligence into the operating room. Using many of the same technologies that underpin self-driving cars, autonomous drones and warehouse robots, researchers are working to automate surgical robots too. These methods are still a long way from everyday use, but progress is accelerating.Dr. Danyal Fer, a surgeon and researcher, has long used robots while operating on patients.Sarahbeth Maney for The New York Times“It is an exciting time,” said Russell Taylor, a professor at Johns Hopkins University and former IBM researcher known in the academic world as the father of robotic surgery. “It is where I hoped we would be 20 years ago.”The aim is not to remove surgeons from the operating room but to ease their load and perhaps even raise success rates — where there is room for improvement — by automating particular phases of surgery.Robots can already exceed human accuracy on some surgical tasks, like placing a pin into a bone (a particularly risky task during knee and hip replacements). The hope is that automated robots can bring greater accuracy to other tasks, like incisions or suturing, and reduce the risks that come with overworked surgeons.During a recent phone call, Greg Hager, a computer scientist at Johns Hopkins, said that surgical automation would progress much like the Autopilot software that was guiding his Tesla down the New Jersey Turnpike as he spoke. The car was driving on its own, he said, but his wife still had her hands on the wheel, should anything go wrong. And she would take over when it was time to exit the highway.“We can’t automate the whole process, at least not without human oversight,” he said. “But we can start to build automation tools that make the life of a surgeon a little bit easier.”Five years ago, researchers with the Children’s National Health System in Washington, D.C., designed a robot that could automatically suture the intestines of a pig during surgery. It was a notable step toward the kind of future envisioned by Dr. Hager. But it came with an asterisk: The researchers had implanted tiny markers in the pig’s intestines that emitted a near-infrared light and helped guide the robot’s movements.Scientists believe neural networks will eventually help surgical robots perform operations on their own.Sarahbeth Maney for The New York TimesThe method is far from practical, as the markers are not easily implanted or removed. But in recent years, artificial intelligence researchers have significantly improved the power of computer vision, which could allow robots to perform surgical tasks on their own, without such markers.The change is driven by what are called neural networks, mathematical systems that can learn skills by analyzing vast amounts of data. By analyzing thousands of cat photos, for instance, a neural network can learn to recognize a cat. In much the same way, a neural network can learn from images captured by surgical robots.Surgical robots are equipped with cameras that record three-dimensional video of each operation. The video streams into a viewfinder that surgeons peer into while guiding the operation, watching from the robot’s point of view.But afterward, these images also provide a detailed road map showing how surgeries are performed. They can help new surgeons understand how to use these robots, and they can help train robots to handle tasks on their own. By analyzing images that show how a surgeon guides the robot, a neural network can learn the same skills.This is how the Berkeley researchers have been working to automate their robot, which is based on the da Vinci Surgical System, a two-armed machine that helps surgeons perform more than a million procedures a year. Dr. Fer and his colleagues collect images of the robot moving the plastic rings while under human control. Then their system learns from these images, pinpointing the best ways of grabbing the rings, passing them between claws and moving them to new pegs.But this process came with its own asterisk. When the system told the robot where to move, the robot often missed the spot by millimeters. Over months and years of use, the many metal cables inside the robot’s twin arms have stretched and bent in small ways, so its movements were not as precise as they needed to be.Human operators could compensate for this shift, unconsciously. But the automated system could not. This is often the problem with automated technology: It struggles to deal with change and uncertainty. Autonomous vehicles are still far from widespread use because they aren’t yet nimble enough to handle all the chaos of the everyday world.From left: At the University of California, Berkeley, Ken Goldberg, an engineering professor; Samuel Paradis, a master’s student; Brijen Thananjeyan, a doctoral candidate; and Dr. Minho Hwang watched as the da Vinci Research Kit conducted the peg transfer.Sarahbeth Maney for The New York TimesThe Berkeley team decided to build a new neural network that analyzed the robot’s mistakes and learned how much precision it was losing with each passing day. “It learns how the robot’s joints evolve over time,” said Brijen Thananjeyan, a doctoral student on the team. Once the automated system could account for this change, the robot could grab and move the plastics rings, matching the performance of human operators.Other labs are trying different approaches. Axel Krieger, a Johns Hopkins researcher who was part of the pig-suturing project in 2016, is working to automate a new kind of robotic arm, one with fewer moving parts and that behaves more consistently than the kind of robot used by the Berkeley team. Researchers at the Worcester Polytechnic Institute are developing ways for machines to carefully guide surgeons’ hands as they perform particular tasks, like inserting a needle for a cancer biopsy or burning into the brain to remove a tumor.“It is like a car where the lane-following is autonomous but you still control the gas and the brake,” said Greg Fischer, one of the Worcester researchers.Many obstacles lie ahead, scientists note. Moving plastic pegs is one thing; cutting, moving and suturing flesh is another. “What happens when the camera angle changes?” said Ann Majewicz Fey, an associate professor at the University of Texas, Austin. “What happens when smoke gets in the way?”For the foreseeable future, automation will be something that works alongside surgeons rather than replaces them. But even that could have profound effects, Dr. Fer said. For instance, doctors could perform surgery across distances far greater than the width of the operating room — from miles or more away, perhaps, helping wounded soldiers on distant battlefields.The signal lag is too great to make that possible currently. But if a robot could handle at least some of the tasks on its own, long-distance surgery could become viable, Dr. Fer said: “You could send a high-level plan and then the robot could carry it out.”The same technology would be essential to remote surgery across even longer distances. “When we start operating on people on the moon,” he said, “surgeons will need entirely new tools.”

SharecloseShare pageCopy linkAbout sharingimage copyrightCitizenGOA Kenyan doctor who became a vociferous opponent of Covid-19 vaccines has succumbed to the virus, weeks after saying the jabs were “totally unnecessary”. Dr Stephen Karanja, chairman of the Kenya Catholic Doctors Association, advocated steam inhalation and hydroxychloroquine tablets. He clashed with the Catholic church over the safety of Covid jabs.Health authorities and the World Health Organization (WHO) rejected his claims. “[The vaccine] being distributed in Kenya, has been reviewed and found safe not only by the WHO rigorous process but also by several stringent regulatory authorities,” the WHO said in March.Africa Live: Latest updates from across the continentKenyan nurse: ‘I was shunned over coronavirus fears’The women fighting South Africa’s ‘infodemic’The Kenya Conference of Catholic Bishops also distanced itself from Dr Karanja’s view on Covid-19 vaccines, saying the vaccines were “licit and ethically acceptable.” Kenya received just over a million vaccine doses from the global Covax initiative, most of which have been administered. The country has confirmed more than 160,000 cases and 2,707 deaths. In March, the government imposed another lockdown restricting movement in five counties after a surge in new infections.What did Dr Karanja say about Covid vaccines?In a letter dated 3 March Dr Karanja said that “there are drugs that have been repurposed and used effectively to treat Covid-19,” adding that “we also know that vaccination for this disease is totally unnecessary making the motivation suspect.”He went on in different forums to advocate alternative treatments, including steam inhalation and a cocktail of drugs – including hydroxychloroquine and Ivermectin, which have not been approved by the WHO to treat Covid-19.Covid-19 and hydroxychloroquine: What do we know?The South African debate over IvermectinDr Karanja, who was an obstetrician and gynaecologist, died on Thursday a week after he was admitted to hospital suffering from complications caused by a Covid-19 infection.What else has Dr Karanja said?Before falling out with the Catholic church in Kenya about the safety and efficacy of the Covid-19 vaccine, Dr Karanja often allied with the religious leaders to oppose mass vaccination campaigns. In 2019 he led opposition against vaccination of schoolgirls against cervical cancer, saying the jab against Human Papilloma Virus (HPV) was unnecessary because it affected those “whose lifestyle involves irresponsible sexual behaviours”. In 2014, his association opposed the government’s rollout of a tetanus vaccine targeting women, claiming it was a sterilisation campaign, despite local health authorities, the WHO, and the UN children’s agency Unicef saying the vaccine was safe.In both instances the government carried on with its plans, but officials reported that they encountered vaccine hesitancy as a result of the objections raised by Dr Karanja.He was also a prominent anti-abortion campaigner and appeared in court in 2018 as an expert witness in a case in which the government was sued for withdrawing guidelines on abortion. The high court ruled that the government decision was unlawful and illegal. Though shunned by a majority of health professionals in Kenya, the Catholic church recognised his association, but often hastened to add that Dr Karanja did not speak for the Catholic church.”The mandate of the church is to speak on matters of morality and faith. The mandate of the doctors is to speak on their understanding of their scientific practice. We are not at variance,” Father Ferdinand Lugonzo, the Kenya Conference of Catholic Bishops spokesperson, told the BBC.A SIMPLE GUIDE: How do I protect myself?IMPACT: What the virus does to the bodyRECOVERY: How long does it take?

Through T cell engineering, researchers at Virginia Commonwealth University Massey Cancer Center show that it’s possible to arrest tumor growth for a variety of cancers and squash the spread of cancer to other tissues. This research will be published in tomorrow’s print edition of Cancer Research.
The paper builds on decades of research by study co-senior author Paul B. Fisher, M.Ph., Ph.D., a member of Massey’s Cancer Biology research program, who discovered a protein called IL-24 that attacks a variety of cancers in several different ways.
In this latest study, Fisher teamed up with his colleague Xiang-Yang (Shawn) Wang, Ph.D., who co-leads the Developmental Therapeutics research program at Massey, to deliver the gene coding for IL-24, which is called MDA-7, to solid tumors using T cells.
“I think the beauty of what we’ve been involved in is that it expands the scope of immunotherapy,” said Fisher, professor and chair of the Department of Human and Molecular Genetics at the VCU School of Medicine, director of the VCU Institute of Molecular Medicine (VIMM) and Thelma Newmeyer Corman Endowed Chair in Oncology Research. “Our approach is less dependent on cancer cells expressing something specific to target.”
After all, this isn’t the first time T cells have been engineered for cancer immunotherapy. FDA-approved chimeric antigen receptor T (CAR-T) cell therapy — which is designed to destroy cancer cells expressing specific surface molecules — has shown tremendous success for treating advanced cancers of the blood and lymphatic systems.
But CAR-T has made limited progress on solid tumors, such as prostate cancer or melanoma, because the cells that make up those tumors aren’t all the same, which blocks the engineered T cells from recognizing and attacking.

Researchers have created a new gene editing tool called Retron Library Recombineering (RLR) that can generate up to millions of mutations simultaneously, and ‘barcodes’ mutant bacterial cells so that the entire pool can be screened at once. It can be used in contexts where CRISPR is toxic or not feasible, and results in better editing rates.
While the CRISPR-Cas9 gene editing system has become the poster child for innovation in synthetic biology, it has some major limitations. CRISPR-Cas9 can be programmed to find and cut specific pieces of DNA, but editing the DNA to create desired mutations requires tricking the cell into using a new piece of DNA to repair the break. This bait-and-switch can be complicated to orchestrate, and can even be toxic to cells because Cas9 often cuts unintended, off-target sites as well.
Alternative gene editing techniques called recombineering instead perform this bait-and-switch by introducing an alternate piece of DNA while a cell is replicating its genome, efficiently creating genetic mutations without breaking DNA. These methods are simple enough that they can be used in many cells at once to create complex pools of mutations for researchers to study. Figuring out what the effects of those mutations are, however, requires that each mutant be isolated, sequenced, and characterized: a time-consuming and impractical task.
Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard Medical School (HMS) have created a new gene editing tool called Retron Library Recombineering (RLR) that makes this task easier. RLR generates up to millions of mutations simultaneously, and “barcodes” mutant cells so that the entire pool can be screened at once, enabling massive amounts of data to be easily generated and analyzed. The achievement, which has been accomplished in bacterial cells, is described in a recent paper in PNAS.
“RLR enabled us to do something that’s impossible to do with CRISPR: we randomly chopped up a bacterial genome, turned those genetic fragments into single-stranded DNA in situ, and used them to screen millions of sequences simultaneously,” said co-first author Max Schubert, Ph.D., a postdoc in the lab of Wyss Core Faculty member George Church, Ph.D. “RLR is a simpler, more flexible gene editing tool that can be used for highly multiplexed experiments, which eliminates the toxicity often observed with CRISPR and improves researchers’ ability to explore mutations at the genome level.”
Retrons: from enigma to engineering tool
Retrons are segments of bacterial DNA that undergo reverse transcription to produce fragments of single-stranded DNA (ssDNA). Retrons’ existence has been known for decades, but the function of the ssDNA they produce flummoxed scientists from the 1980s until June 2020, when a team finally figured out that retron ssDNA detects whether a virus has infected the cell, forming part of the bacterial immune system.

Scientists have known for a while that SARS-CoV-2’s distinctive “spike” proteins help the virus infect its host by latching on to healthy cells. Now, a major new study shows that they also play a key role in the disease itself.
The paper, published on April 30, 2021, in Circulation Research, also shows conclusively that COVID-19 is a vascular disease, demonstrating exactly how the SARS-CoV-2 virus damages and attacks the vascular system on a cellular level. The findings help explain COVID-19’s wide variety of seemingly unconnected complications, and could open the door for new research into more effective therapies.
“A lot of people think of it as a respiratory disease, but it’s really a vascular disease,” says Assistant Research Professor Uri Manor, who is co-senior author of the study. “That could explain why some people have strokes, and why some people have issues in other parts of the body. The commonality between them is that they all have vascular underpinnings.”
Salk researchers collaborated with scientists at the University of California San Diego on the paper, including co-first author Jiao Zhang and co-senior author John Shyy, among others.
While the findings themselves aren’t entirely a surprise, the paper provides clear confirmation and a detailed explanation of the mechanism through which the protein damages vascular cells for the first time. There’s been a growing consensus that SARS-CoV-2 affects the vascular system, but exactly how it did so was not understood. Similarly, scientists studying other coronaviruses have long suspected that the spike protein contributed to damaging vascular endothelial cells, but this is the first time the process has been documented.
In the new study, the researchers created a “pseudovirus” that was surrounded by SARS-CoV-2 classic crown of spike proteins, but did not contain any actual virus. Exposure to this pseudovirus resulted in damage to the lungs and arteries of an animal model — proving that the spike protein alone was enough to cause disease. Tissue samples showed inflammation in endothelial cells lining the pulmonary artery walls.
The team then replicated this process in the lab, exposing healthy endothelial cells (which line arteries) to the spike protein. They showed that the spike protein damaged the cells by binding ACE2. This binding disrupted ACE2’s molecular signaling to mitochondria (organelles that generate energy for cells), causing the mitochondria to become damaged and fragmented.
Previous studies have shown a similar effect when cells were exposed to the SARS-CoV-2 virus, but this is the first study to show that the damage occurs when cells are exposed to the spike protein on its own.
“If you remove the replicating capabilities of the virus, it still has a major damaging effect on the vascular cells, simply by virtue of its ability to bind to this ACE2 receptor, the S protein receptor, now famous thanks to COVID,” Manor explains. “Further studies with mutant spike proteins will also provide new insight towards the infectivity and severity of mutant SARS CoV-2 viruses.”
The researchers next hope to take a closer look at the mechanism by which the disrupted ACE2 protein damages mitochondria and causes them to change shape.
Other authors on the study are Yuyang Lei and Zu-Yi Yuan of Jiaotong University in Xi’an, China; Cara R. Schiavon, Leonardo Andrade, and Gerald S. Shadel of Salk; Ming He, Hui Shen, Yichi Zhang, Yoshitake Cho, Mark Hepokoski, Jason X.-J. Yuan, Atul Malhotra, Jin Zhang of the University of California San Diego; Lili Chen, Qian Yin, Ting Lei, Hongliang Wang and Shengpeng Wang of Xi’an Jiatong University Health Science Center in Xi’an, China.
The research was supported by the National Institutes of Health, the National Natural Science Foundation of China, the Shaanxi Natural Science Fund, the National Key Research and Development Program, the First Affiliated Hospital of Xi’an Jiaotong University; and Xi’an Jiaotong University.

Scientists at the University of Nottingham have developed an ultrasonic imaging system, which can be deployed on the tip of a hair-thin optical fibre, and will be insertable into the human body to visualise cell abnormalities in 3D.
The new technology produces microscopic and nanoscopic resolution images that will one day help clinicians to examine cells inhabiting hard-to-reach parts of the body, such as the gastrointestinal tract, and offer more effective diagnoses for diseases ranging from gastric cancer to bacterial meningitis.
The high level of performance the technology delivers is currently only possible in state-of-the-art research labs with large, scientific instruments — whereas this compact system has the potential to bring it into clinical settings to improve patient care.
The Engineering and Physical Sciences Research Council (EPSRC)-funded innovation also reduces the need for conventional fluorescent labels — chemicals used to examine cell biology under a microscope — which can be harmful to human cells in large doses.
The findings are being reported in a new paper, entitled ‘Phonon imaging in 3D with a fibre probe’ published in the Nature journal, Light: Science & Applications.
Paper author, Salvatore La Cavera, an EPSRC Doctoral Prize Fellow from the University of Nottingham Optics and Photonics Research Group, said of the ultrasonic imaging system: “We believe its ability to measure the stiffness of a specimen, its bio-compatibility, and its endoscopic-potential, all while accessing the nanoscale, are what set it apart. These features set the technology up for future measurements inside the body; towards the ultimate goal of minimally invasive point-of-care diagnostics.”
Currently at prototype stage, the non-invasive imaging tool, described by the researchers as a “phonon probe,” is capable of being inserted into a standard optical endoscope, which is a thin tube with a powerful light and camera at the end that is navigated into the body to find, analyse, and operate on cancerous lesions, among many other diseases. Combining optical and phonon technologies could be advantageous; speeding up the clinical workflow process and reducing the number of invasive test procedures for patients.

Mitochondria are the energy suppliers of our body cells. These tiny cell components have their own genetic material, which triggers an inflammatory response when released into the interior of the cell. The reasons for the release are not yet known, but some cardiac and neurodegenerative diseases as well as the ageing process are linked to the mitochondrial genome. Researchers at the Max Planck Institute for Biology of Ageing and the CECAD Cluster of Excellence in Ageing research have investigated the reasons for the release of mitochondrial genetic material and found a direct link to cellular metabolism: when the cell’s DNA building blocks are in short supply, mitochondria release their genetic material and trigger inflammation. The researchers hope to find new therapeutic approaches by influencing this metabolic pathway.
Our body needs energy — for every metabolic process, every movement and for breathing. This energy is produced in tiny components of our body cells, the so-called mitochondria. Unlike other cell components, mitochondria have their own genetic material, mitochondrial DNA. However, in certain situations, mitochondria release their DNA into the interior of the cell, causing a reaction from the cell’s own immune system and being associated with various diseases as well as the ageing process. The reasons for the release of mitochondrial DNA are not yet known.
Shortage of DNA building blocks triggers inflammatory reaction
To answer the question of when mitochondria release their DNA, researchers at the Max Planck Institute for Biology of Ageing have focused on the mitochondrial protein YME1L, which owes its name to yeast mutants that release their mitochondrial DNA — yeast mitochondrial escape 1. “In cells lacking YME1L, we observed the release of mitochondrial DNA into the cell interior and a related immune response in the cells,” said Thomas MacVicar, one of the study’s two first authors. Closer examination revealed a direct link to the building blocks of DNA. “If the cells lack YME1L, there is a deficiency of DNA building blocks inside the cell,” Thomas MacVicar describes. “This deficiency triggers the release of mitochondrial DNA, which in turn causes an inflammatory response in the cell: the cell stimulates similar inflammatory reactions as it does during a bacterial or viral infection. If we add DNA building blocks to the cells from the outside, that also stops the inflammation.”
New therapeutic approaches based on the metabolism of DNA building blocks
The discovered link between the cellular inflammatory response and the metabolism of DNA building blocks could have far-reaching consequences, explains Thomas MacVicar: “Some viral inhibitors stop the production of certain DNA building blocks, thereby triggering an inflammatory response. The release of mitochondrial DNA could be a crucial factor in this, contributing to the effect of these inhibitors.” Several ageing-associated inflammatory diseases, including cardiac and neurodegenerative diseases, as well as obesity and cancer, are linked to mitochondrial DNA. The authors hope that modulating the metabolism of DNA building blocks will offer new therapeutic opportunities in such diseases.
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