SharecloseShare pageCopy linkAbout sharingimage copyrightReutersThe head of the World Health Organization (WHO) says further investigation is needed to conclusively rule out a theory that Covid-19 emerged from a laboratory in China. Tedros Adhanom Ghebreyesus said on Tuesday that although a laboratory leak is the least likely cause, more extensive research is needed.The virus was first detected in Wuhan, in China’s Hubei province in late 2019.The Chinese government has dismissed the allegations of a virus leak.Since the novel coronavirus was first identified, more than 2.7 million people are known to have died from it, with more than 127 million cases worldwide.An international team of experts travelled to Wuhan in January to probe the origins of the virus. Their research relied on samples and evidence provided by Chinese officials. Dr Tedros said the team had difficulty accessing raw data and called for “more timely and comprehensive data sharing” in the future. image copyrightReutersThe team investigated all possibilities, including one theory that the virus had originated at the Wuhan Institute of Virology. The institute is the world’s leading authority on the collection, storage and study of bat coronaviruses. Former US President Donald Trump was among those who supported the theory that the virus might have escaped from a lab.But a report by WHO and Chinese experts released on Tuesday and seen by AFP news agency, said the lab leak explanation was highly unlikely and the virus had probably jumped from bats to humans via another intermediary animal. Wuhan- City of silenceWuhan marks its anniversary with triumph and denialHowever the theory “requires further investigation, potential with additional missions involving specialist experts,” Dr Tedros said. “Let me say clearly that as far as WHO is concerned, all hypothesis remain on the table,” he added. Also on Tuesday, WHO investigation team leader, Peter Ben Embarek, said his team had found no evidence that any laboratories in Wuhan were involved in the outbreak. He added that his team had felt under political pressure, including from outside China but said he was never pressed to remove anything from the team’s final report.Dr Embarak added that it was “perfectly possible” that cases were circulating in the Wuhan area in October or November 2019. China informed the WHO about cases on 3 January, a month after the first reported infection. Shortly after, the US and 13 allies including South Korea, Australia and the UK, voiced concern over the report and urged China to provide “full access” to experts. The statement said the mission to Wuhan was “significantly delayed and lacked access to complete, original data and samples”.The group pledged to work together with the WHO. China has refuted claims the virus originated in a lab and says that although Wuhan is where the first cluster of cases was detected, it is not necessarily where the virus originated. State media has claimed that the virus may have arrived in Wuhan on frozen food imports.The country has largely brought its own outbreak under control through quick mass testing, stringent lockdowns and tight travel restrictions.

It makes evolutionary sense for long-lived animals to have complex social relationships — such as friends and enemies — researchers say.
Some species and individuals focus their energy on reproduction (live fast, die young), while “slow-living” animals prioritise survival and tend to live longer lives.
In the new paper, University of Exeter scientists argue that natural selection favours complex social structures among slow-living animals — meaning that knowing their friends and enemies is easier for animals with longer lifespans, and helps them live even longer.
Meanwhile, fast-lived species should only bother with such social relationships if it increases their chances of reproduction.
“Slow-living species can afford to invest in social relationships, as they live long enough to enjoy the pay-offs,” said Professor Dave Hodgson, Director of the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.
“There is strong evidence that strong social bonds are beneficial for survival in slow-living species, including humans.

Drinking beetroot juice promotes a mix of mouth bacteria associated with healthier blood vessels and brain function, according to a new study of people aged 70-80.
Beetroot — and other foods including lettuce, spinach and celery — are rich in inorganic nitrate, and many oral bacteria play a role in turning nitrate to nitric oxide, which helps to regulate blood vessels and neurotransmission (chemical messages in the brain).
Older people tend to have lower nitric oxide production, and this is associated with poorer vascular (blood vessel) and cognitive (brain) health.
In the new study, by the University of Exeter, 26 healthy older people took part in two ten-day supplementation periods: one with nitrate-rich beetroot juice and another with nitrate-free placebo juice, which they drank twice a day.
The results showed higher levels of bacteria associated with good vascular and cognitive health, and lower levels of bacteria linked to disease and inflammation.
Systolic blood pressure dropped on average by five points (mmHg) after drinking the beetroot juice.

Remote monitoring using airborne devices such as drones or satellites could revolutionise the effectiveness of nature-based solutions (NBS) that protect communities from devastating natural hazards such as floods, storms and landslides, say climate change experts from the University of Surrey.
Grey structural measures (a collective term for engineering projects that use concrete and steel) like floodgates, dams, dikes and sea walls are still the most common methods to guard against natural hazards. However, these ‘grey measures’ are expensive and lack the long-term flexibility and sustainability needed to help communities manage their growing population and address the planet’s ongoing struggle against urbanisation and climate change. While NBS are cost-effective, their usability and reproducibility are often hindered by the lack of standard monitoring methods, tools and indicators.
In a comprehensive study published in the Earth-Science Reviews journal, researchers from Surrey’s Global Centre for Clean Air Research (GCARE) collaborated with experts from across Europe to analyse monitoring methods that measure the effectiveness of NBS — such as wetlands, forest restoration projects and installation of green walls.
In the paper, the team found that while there is a need for combining ground and remote monitoring methods for holistic assessment, the advances in remote monitoring techniques present a significant source of hope for routinely, continually and accurately measuring the effectiveness of NBS and quelling skepticism around choosing NBS over grey-engineered options. Remote monitoring offers the ability to cover large geographical areas, and high-resolution imagery could change the way farmers, scientists, hazard managers and other decision-makers view NBS usage and applicability.
However, the study also warns that the lack of globally accepted standards to gauge an NBS success hinders their progress and use and needs to be urgently addressed.
Professor Prashant Kumar, Associate Dean (International) and the Director of the GCARE at the University of Surrey, said: “Unfortunately we do expect a significant uptick in natural hazards, thanks to climate change. Therefore, our decisions on how we protect ourselves are crucial, and nature-based solutions have the advantages of being flexible and not adding to the damage caused to our environment.
“I hope that this review begins an urgent discussion on how we can move forward as a scientific community and start to develop an accepted framework for measuring the effectiveness of nature-based solutions.”
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Scientists have discovered that tracking malaria as it develops in humans is a powerful way to detect how the malaria parasite causes a range of infection outcomes in its host.
The study, found some remarkable differences in the way individuals respond to malaria and raises fresh questions in the quest to understand and defeat the deadly disease.
Malaria, caused by the parasite — Plasmodium falciparum — is a huge threat to adults and children in the developing world. Each year, around half a million people die from the disease and another 250 million are infected. Malaria parasites are spread to humans through the bites of infected mosquitoes.
The outcomes that follow a malaria infection can vary from no symptoms to life-threatening disease and death. The precise reasons why people respond in different ways to the same parasite infection are still unknown, experts say.
Researchers from the University of Edinburgh, in collaboration with teams at the Universities of Oxford and Glasgow and the Wellcome Trust Sanger Institute, explored infection outcomes in 14 volunteers who were injected with malaria parasites.
Scientists studied how the volunteers responded to the parasites over the course of 10 days. The group were then treated with antimalarial drugs to cure the infection before there was any risk of them developing severe symptoms.

Adding the nutrient selenium to diets protects against obesity and provides metabolic benefits to mice, according to a study published today in eLife.
The results could lead to interventions that reproduce many of the anti-aging effects associated with dietary restriction while also allowing people to eat as normal.
Several types of diet have been shown to increase healthspan — that is, the period of healthy lifespan. One of the proven methods of increasing healthspan in many organisms, including non-human mammals, is to restrict dietary intake of an amino acid called methionine.
Recent studies have suggested that the effects of methionine restriction on healthspan are likely to be conserved in humans. Although it might be feasible for some people to practice methionine restriction, for example, by adhering to a vegan diet, such a diet might not be practical or desirable for everyone. In the current study, a research team from the Orentreich Foundation for the Advancement of Science (OFAS), Cold Spring, New York, US, aimed to develop an intervention that produces the same effects as methionine restriction, while also allowing an individual to eat a normal, unrestricted diet.
An important clue for developing such a treatment is that methionine restriction causes a decrease in the amounts of an energy-regulating hormone called IGF-1. If a treatment could be found that causes a similar decrease in IGF-1, this might also have beneficial effects on healthspan. Previous research has shown that selenium supplementation reduces the levels of circulating IGF-1 in rats, suggesting that this could be an ideal candidate.
The team first studied whether selenium supplementation offered the same protection against obesity as methionine restriction. They fed young male and older female mice one of three high-fat diets: a control diet containing typical amounts of methionine, a methionine-restricted diet, and a diet containing typical amounts of methionine as well as a source of selenium. For both male and female mice of any age, the authors found that selenium supplementation completely protected against the dramatic weight gain and fat accumulation seen in mice fed the control diet, and to the same extent as restricting methionine.
Next, they explored the effects of the three diets on physiological changes normally associated with methionine restriction. To do this, they measured the amounts of four metabolic markers in blood samples from the previously treated mice. As hoped, they found dramatically reduced levels of IGF-1 in both male and female mice. They also saw reductions in the levels of the hormone leptin, which controls food intake and energy expenditure. Their results indicate that selenium supplementation produces most, if not all, of the hallmarks of methionine restriction, which suggests that this intervention may have a similar positive effect on healthspan.
To gain insight into the beneficial effects of selenium supplementation, the researchers used a different organism — yeast. The two most widely used measurements of healthspan in yeast are chronological lifespan, which tells us how long dormant yeast remain viable, and replicative lifespan, which measures the number of times a yeast cell can produce new offspring. The team previously showed that methionine restriction increases the chronological lifespan of yeast, so they tested whether selenium supplementation might do the same. As it turned out, yeast grown under selenium-supplemented conditions had a 62% longer chronological lifespan (from 13 days to 21 days) and a replicative lifespan extended by nine generations as compared with controls. This demonstrates that supplementing yeast with selenium produces benefits to healthspan detectable by multiple tests of cell aging.
“One of the major goals of aging research is to identify simple interventions that promote human healthspan,” notes senior author Jay Johnson, Senior Scientist at OFAS. “Here we present evidence that short-term administration of either organic or inorganic sources of selenium provides multiple health benefits to mice, the most notable of which being the prevention of diet-induced obesity. In the long term, we expect that supplementation with these compounds will also prevent age-related disease and extend the overall survival of mice. It is our hope that many of the benefits observed for mice will also hold true for humans.”
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For decades, the power of the placebo effect was thought to lie in patients’ belief that they were — or at least, could be — receiving a pharmacologically active treatment. A new study by physician-researchers at Beth Israel Deaconess Medical Center (BIDMC) suggests that patients don’t need to be deceived to receive benefit from treatment with placebo.
In a randomized clinical trial published in the journal PAIN, researchers found participants with moderate to severe irritable bowel syndrome (IBS) who were knowingly treated with a pharmacologically inactive pill — referred to as an honest or open-label placebo — reported clinically meaningful improvements in their IBS symptoms. People who received the open-label placebo experienced improvements that were significantly greater than those reported by participants assigned to a no-pill control group. There was no difference in symptom improvement between those who received open-label or double-blind placebos. The results build on the research team’s previous findings and challenge the long-held notion that concealment or deception are key elements in the placebo effect.
“The clinical response to open-label placebo in this six-week trial was high, with 69 percent of participants who received open-label placebo reporting a clinically meaningful improvement in their symptoms,” said first and corresponding author Anthony J. Lembo, MD, Professor of Medicine in the Division of Gastroenterology at BIDMC. “IBS is one of the most common reasons for healthcare consultations and absenteeism from work or school. Effective treatment options for IBS are limited, and we hypothesized it may be possible to ethically harness the placebo effect for clinical benefit.”
For the rigorously designed clinical trial, researchers enrolled 262 adult participants, 18 to 80 years old with at least moderately severe irritable bowel syndrome, as measured by the validated IBS-Severity Scoring System (IBS-SSS), which measures frequency and severity of abdominal pain and distention, quality of life and other relevant factors across a scale of 0-500. Participants were examined, filled out baseline questionnaires and were randomized into one of three study arms; open-label placebo; double-blind (which included double-blind placebo or double-blind peppermint oil); or no-pill control. During their examinations, all participants discussed the placebo effect, the trial and its aims with their physicians.
The open-label group received pill bottles labeled “open-label placebo,” and were told that the pills inside were pharmacologically inert, but could make them feel better through the placebo effect. The double-blind group received pill bottles labeled “double-blind placebo or peppermint oil.” Participants in the double-blind group received either a placebo or an identical pill containing peppermint oil, but neither they nor the research team knew which they received. All participants who received pills were instructed to take one pill three times a day, 30 minutes before meals. The no-pill control group received no pills but otherwise followed identical study protocol. During return visits three and six weeks into the study, all participants completed questionnaires, were verbally asked about adverse events and briefly met with a study physician.
Lembo and colleagues — including senior author, Ted J. Kaptchuk, Director of the Program in Placebo Studies and the Therapeutic Encounter at BIDMC — found that improvement in IBS-SSS scores from baseline to the six-week endpoint was significantly greater in the open-label placebo group compared to the no-pill control group. Additionally, participants in the double-blind placebo group also saw superior symptom improvement compared to the no-pill control group, but the double-blind and open-label groups were not different from each other.
Next, the researchers performed a post hoc analysis of the participants who experienced large clinical improvements — those who improved by at least 50 points and by at least 150 points, considered strong and very strong clinical responses, respectively. A greater percentage of participants in the open-label placebo and double-blind placebo groups reported a 50 point reduction in IBS severity score compared to the no-pill control group (approximately 70 percent in each placebo group compared to 54 percent in the no pill control group). Similarly, approximately 30 percent of open-label placebo and double-blind placebo participants reported a 150 point reduction in IBS symptoms, compared to only 12 percent of the no-pill group.
“If the presumption that deception is necessary for placebos to be effective is false, then many theories about the mechanisms that drive placebo effects may need modification,” said Kaptchuk, who with colleagues in 2010, published the results of the first randomized controlled trial to show that patients with IBS responded well to treatment with open-label placebo. Subsequent research has demonstrated similar findings in patients with what they call subjective symptoms, including low back pain, knee pain, cancer-related fatigue, migraine headaches, menopausal hot flashes, and allergic rhinitis. “Our finding that openly prescribed placebo may be as effective as double-blinded placebo has implications for clinical practice and for future research, especially in chronic visceral and somatic pain conditions.”

Washington State University researchers have discovered a protein that could be key to blocking the most common bacterial cause of human food poisoning in the United States.
Chances are, if you’ve eaten undercooked poultry or cross contaminated food by washing raw chicken, you may be familiar with the food-borne pathogen.
“Many people that get sick think, ‘oh, that’s probably Salmonella,’ but it is even more likely it’s Campylobacter,” said Nick Negretti (’20 Ph.D.), a lead member of the research team in Michael Konkel’s Laboratory in WSU’s School of Molecular Biosciences.
According to a study on the research recently published in Nature Communications, a secreted protein known as CiaD facilitates cell entry by Campylobacter and takes control of important cell processes by changing the composition of a protein complex inside the cell.
By gaining insight into the infection process and the specific actions of the Campylobacter secreted proteins, the work gives the WSU team and the rest of the field a foundation to understanding why infections occur and persist.
Until the Konkel Lab’s latest finding, the functions of the bacterium’s proteins and how they infect the cell were largely unknown.

A mechanism has been identified that explains how physical exercise in pregnancy confers metabolic health benefits in offspring. According to researchers, the key lies with a protein called SOD3, vitamin D and adequate exercise, with the outcomes possibly forming the first steps to designing rational diet and exercise programs to use during pregnancy and particularly when mothers may also be overweight or obese.
The study, which was led by authors from the Joslin Diabetes Center at the Harvard Medical School and colleagues from Japan, the US, Canada and Denmark, has been published online by Cell Metabolism.
“We’ve known for a while that risks for obesity and type 2 diabetes can originate in the critical prenatal developmental period,” said senior author Laurie Goodyear. “In particular, there is real concern that the increasing levels of obesity seen in women of reproductive age will transmit disease risk to subsequent generations. It’s important to understand that if this is not alleviated, rates of diabetes and obesity will only continue to grow in the coming years.”
Many previous studies have linked increased maternal body weight and unhealthy diets to poorer metabolic outcomes in offspring, often many years later. Understanding the mechanisms of how maternal exercise can reverse these effects might lead to interventions that prevent these diseases transmitting across generations, say the authors of the study.
“The findings offer an explanation as to why physical exercise during pregnancy may have metabolic benefits for offspring as they get older,” said Goodyear. “We show how physical exercise during pregnancy, in combination with adequate vitamin D levels, enhances levels of a placenta-derived protein called SOD3 (superoxide dismutase 3), and that via a number of intermediate steps, this improves glucose tolerance in offspring.”
The findings come from a series of investigations with pregnant mice, comparing groups exposed to voluntary wheel running (i.e., exercise) and groups that were sedentary. Using various techniques, the authors carefully investigated the effects of exercise on parameters such as DNA methylation, cell signaling and gene expression, particularly in relation to glucose metabolism.

When variants of SARS-CoV-2 (the virus that causes COVID-19) emerged in late 2020, concern arose that they might elude protective immune responses generated by prior infection or vaccination, potentially making re-infection more likely or vaccination less effective. To investigate this possibility, researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and colleagues analyzed blood cell samples from 30 people who had contracted and recovered from COVID-19 prior to the emergence of virus variants. They found that one key player in the immune response to SARS-CoV-2 — the CD8+ T cell — remained active against the virus.
The research team was led by NIAID’s Andrew Redd, Ph.D., and included scientists from Johns Hopkins University School of Medicine, Johns Hopkins Bloomberg School of Public Health and the immunomics-focused company, ImmunoScape.
The investigators asked whether CD8+ T cells in the blood of recovered COVID-19 patients, infected with the initial virus, could still recognize three SARS-CoV-2 variants: B.1.1.7, which was first detected in the United Kingdom; B.1.351, originally found in the Republic of South Africa; and B.1.1.248, first seen in Brazil. Each variant has mutations throughout the virus, and, in particular, in the region of the virus’ spike protein that it uses to attach to and enter cells. Mutations in this spike protein region could make it less recognizable to T cells and neutralizing antibodies, which are made by the immune system’s B cells following infection or vaccination.
Although details about the exact levels and composition of antibody and T-cell responses needed to achieve immunity to SARS-CoV-2 are still unknown, scientists assume that strong and broad responses from both antibodies and T cells are required to mount an effective immune response. CD8+ T cells limit infection by recognizing parts of the virus protein presented on the surface of infected cells and killing those cells.
In their study of recovered COVID-19 patients, the researchers determined that SARS-CoV-2-specific CD8+ T-cell responses remained largely intact and could recognize virtually all mutations in the variants studied. While larger studies are needed, the researchers note that their findings suggest that the T cell response in convalescent individuals, and most likely in vaccinees, are largely not affected by the mutations found in these three variants, and should offer protection against emerging variants.
Optimal immunity to SARS-Cov-2 likely requires strong multivalent T-cell responses in addition to neutralizing antibodies and other responses to protect against current SARS-CoV-2 strains and emerging variants, the authors indicate. They stress the importance of monitoring the breadth, magnitude and durability of the anti-SARS-CoV-2 T-cell responses in recovered and vaccinated individuals as part of any assessment to determine if booster vaccinations are needed.
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