Boris Johnson has announced a new “antivirals task force” to find “promising new medicines” to treat Covid by autumn.Speaking at the Downing Street briefing on Tuesday, the prime minister is hoping that people will be able to take a pill or tablet at home.
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Astronauts who spend extended time in space face stressors such as isolation, confinement, lack of privacy, altered light-dark cycles, monotony and separation from family. Interestingly, so do people who work at international research stations in Antarctica, where the extreme environment is characterized by numerous stressors that mirror those present during long-duration space exploration.
To better understand the psychological hurdles faced by astronauts, University of Houston professor of psychology Candice Alfano and her team developed the Mental Health Checklist (MHCL), a self-reporting instrument for detecting mental health changes in isolated, confined, extreme (ICE) environments. The team used the MHCL to study psychological changes at two Antarctic stations. The findings are published in Acta Astronautica.
“We observed significant changes in psychological functioning, but patterns of change for specific aspects of mental health differed. The most marked alterations were observed for positive emotions such that we saw continuous declines from the start to the end of the mission, without evidence of a ‘bounce-back effect’ as participants were preparing to return home,” reports Alfano. “Previous research both in space and in polar environments has focused almost exclusively on negative emotional states including anxiety and depressive symptoms. But positive emotions such as satisfaction, enthusiasm and awe are essential features for thriving in high-pressure settings.”
Negative emotions also increased across the study, but changes were more variable and predicted by physical complaints. Collectively, these results might suggest that while changes in negative emotions are shaped by an interaction of individual, interpersonal and situational factors, declines in positive emotions are a more universal experience in ICE environments. “Interventions and counter measures aimed at enhancing positive emotions may, therefore, be critical in reducing psychological risk in extreme settings,” said Alfano.
At coastal and inland Antarctic stations, Alfano and her team tracked mental health symptoms across a nine-month period, including the harshest winter months, using the MHCL. A monthly assessment battery also examined changes in physical complaints, biomarkers of stress such as cortisol, and the use of different emotion regulation strategies for increasing or decreasing certain emotions.
Study results also revealed that participants tended to use fewer effective strategies for regulating (i.e., increasing) their positive emotions as their time at the stations increased.
“Both the use of savoring — purposely noticing, appreciating, and/or intensifying positive experiences and emotions — and reappraisal — changing the way one thinks about a situation — decreased during later mission months compared to baseline. These changes likely help explain observed declines in positive emotions over time,” said Alfano.
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Materials provided by University of Houston. Original written by Laurie Fickman. Note: Content may be edited for style and length.
Recent research links certain cells that line the human airway with different infant diseases. The work, which is published in Cell Reports and was led by investigators at Massachusetts General Hospital (MGH), could lead to new prevention and treatment strategies for these conditions.
The human airway — from the windpipe to the lungs — is lined with epithelial cells, including a type called pulmonary neuroendocrine cells (PNECs) that communicate with the nervous system and secrete different factors and hormones. Increased numbers and clusters of PNECs have been observed in various breathing-related illnesses, but the cells’ roles in health and disease are unclear. To better understand PNECs and their effects in the body, researchers analyzed lung and airway tissues from humans and mice.
The scientists were surprised to find that PNECs are much more varied than previously described. In fact, it appears that the airway harbors three distinct types of PNECs. Some PNECs express a protein called tubulin beta 3 class III (TUBB3), and this protein is required for protrusions involved in communication between the cells and their environment. Therefore, PNECs with and without TUBB3 may have different sensing mechanisms. Also, higher numbers of certain PNECs were present in autopsied tissues from children who had died from diseases such as sudden infant death syndrome and neuroendocrine hyperplasia in infancy, a rare lung disorder of unknown cause.
“We are currently studying how different subpopulations of PNECs differ in their function,” says senior author Xingbin Ai, PhD, a pulmonary disease specialist in the Department of Pediatrics at MGH. “We hope to leverage this knowledge for future development of markers and treatment strategies for infant diseases that involve abnormalities in these cells.”
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Materials provided by Massachusetts General Hospital. Note: Content may be edited for style and length.
Forensic science includes the analysis of blood backspatter involved in gunshot wounds, but scientific questions about the detailed role of fluids in these situations remained unresolved.
To search for answers about how blood droplets from a gunshot wound can reverse direction while in flight, University of Illinois at Chicago and Iowa State University researchers explored the influence of propellant gases on blood backspatter.
In Physics of Fluids, from AIP Publishing, the researchers report using numeric modeling to capture the behavior of gun muzzle gases and predict the reversal of blood droplet flight, which was captured experimentally. Their experiments also show the breakup of blood droplets, a future extension of their modeling efforts.
Propellant gases from gunpowder issue from the gun barrel at high speed and form turbulent vortex rings, which can be visualized by high-speed shadowgraph images, like those used to capture flow structures of supersonic aircraft or spacecraft.
A penetrating bullet tends to spatter blood droplets from the victim backward, toward the shooter, but a turbulent vortex ring of muzzle gases moving from the shooter toward the victim can reverse the flight of the droplets.
The researchers’ prior work focused on modeling the trajectories of blood droplets that lead to bloodstains that end up being analyzed by forensics experts.
“We used proper fluid dynamics models for the aerodynamic drag, which led to significant improvements, but concluded muzzle gases should also be included and can dramatically alter the formation and size of blood droplets,” said Alexander Yarin, a distinguished professor at the University of Illinois at Chicago.
In their most recent work, the researchers identified an additional feature at play beyond deflection and reversal of blood spatter back toward the victim: the secondary breakup of formed droplets in flight, identified by James Michael’s group at Iowa State University.
“We concluded that forensic analysis of formed bloodstains should account for additional uncertainty in the trajectories of droplets, if muzzle gas interactions are present for short-range shooting,” said Yarin. “And while determination of the origin of droplets is often a desirable outcome of forensic analysis, muzzle gas interactions can confound interpretation.”
The researchers’ imaging results made it clear “the size of droplets can be dramatically impacted through the secondary breakup induced by the muzzle gas wind,” said Yarin. “We’re working to analyze this behavior using bloodstain patterns with Drs. James Michael and Daniel Attinger and their team at Iowa State University.”
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Materials provided by American Institute of Physics. Note: Content may be edited for style and length.
Dietary sugars and gut microbes play a key role in promoting malaria parasite infection in mosquitoes. Researchers in China have uncovered evidence that mosquitoes fed a sugar diet show an increased abundance of the bacterial species Asaia bogorensis, which enhances parasite infection by raising the gut pH level. The study appears April 20 in the journal Cell Reports.
“Our work opens a new path for investigations into the role of mosquito-microbiota metabolic interactions concerning their disease-transmitting potential,” says co-senior study author Jingwen Wang of Fudan University in Shanghai, China. “The results may also provide useful insights for the development of preventive strategies for vector control.”
Mosquitoes rely on nectar-derived sugars, such as glucose, for energy, survival, and reproduction. Similarly, glucose is the primary energy source supporting the proliferation of Plasmodium — malaria parasites that are transmitted to human hosts by female mosquitoes of the genus Anopheles. Some indirect evidence also suggests that carbohydrate metabolism influences the capability of mosquitoes to transmit malaria parasites. Although glucose metabolism is expected to play a role in regulating Plasmodium infection in mosquitoes, the underlying mechanisms have not been clear.
To address this question, Wang teamed up with co-senior study author Huiru Tang of Fudan University. They found that feeding Anopheles stephensi mosquitoes a solution containing glucose for five days increased the number of Plasmodium berghei oocytes in the midgut after infection with the parasite. But mosquitoes treated with an antibiotic cocktail did not show this effect, pointing to a critical role for gut microbes in the sugar-induced enhancement of Plasmodium infection.
The sugar diet specifically increased the abundance of A. bogorensis in the mosquito midgut. Infected mosquitoes that were fed glucose and colonized only with A. bogorensis showed an increased number of P. berghei oocytes. Taken together, the findings suggest that sugar intake promotes Plasmodium infection in mosquitoes by increasing the proliferation of A. bogorensis. Additional experiments provided evidence that this bacterial species mediates the sugar-induced enhancement of infection by raising the midgut pH level, which facilitates the sexual development of P. berghei.
“Our study provides crucial molecular insights into how the complex interplay between glucose metabolism of mosquitos and a component of their gut microbiota, A. bogorensis, influences malaria parasite infection,” Tang says. “Targeting mosquito glucose metabolism might be a promising strategy to prevent malaria parasite transmission.”
The study also provides evidence that the specific sugar composition of plant saps might influence malaria transmission by affecting the proliferation of A. bogorensis. Specifically, Parthenium hysterophorus — a plant species that mosquitoes feed on quite frequently — did not promote A. bogorensis proliferation or P. berghei infection when compared with other mosquito-preferred plants. According to the authors, planting this species might reduce malaria transmission. But further studies are needed to investigate the influence of natural plant saps on the microbiota composition of field mosquitoes and to examine the influence of A. bogorensis from field mosquitoes on malaria parasite infection.
The researchers will continue to investigate the metabolic interactions between mosquitos and their microbiota and the influence of these interactions on pathogen transmission. “Our goal is to find out the key metabolites or chemicals that could inhibit malaria parasite infection in mosquitoes,” Wang says.
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Materials provided by Cell Press. Note: Content may be edited for style and length.
Exposure to certain endocrine-disrupting chemicals could elevate the risk of breast cancer, according to a new comprehensive systematic review of epidemiological research. However, for many chemicals, evidence is inconsistent or still limited. The review was carried out by researchers at the universities of Hong Kong and Eastern Finland and published in Critical Reviews in Food Science and Nutrition.
Endocrine-disrupting chemicals (EDCs) can interfere with the body’s hormonal system, also called the endocrine system, and are widely present in the environment. They originate from a variety of sources, including pesticides, plasticisers and other industrial and pharmaceutical chemicals, as well as natural sources. Humans are often exposed to EDCs through food, but other possible exposure routes include drinking water, skin contact and air.
Breast cancer accounts for the majority of women’s cancers. There has been an increasing interest in the role of estrogene-mimicking EDCs, so called xenoestrogens, in the development of breast cancer. They comprise a broad range of pesticides, synthetic chemicals, phytoestrogens and certain mycotoxins. The researchers reviewed 131 epidemiological studies evaluating the link between xenoestrogen exposure and breast cancer. Most studies assessed exposures by measuring the EDCs and their metabolites in urine, serum, plasma or adipose tissues.
Some may be genetically more vulnerable to EDCs
According to the review, the nowadays widely banned pesticide DDT is one of the most studied EDCs in relation to breast cancer risk. Out of 43 epidemiological studies, eleven reported positive associations between DDT or its metabolites in lipid, serum or plasma and breast cancer incidence. Nine reported higher DDT levels among women with breast cancer than among controls. In a few studies, DDT was linked to estrogen-positive breast cancer or the association to breast cancer risk depended on genotype.
Polychlorinated biphenyls, PCBs, are a large group of compounds earlier much used in electrical devices, surface coatings and other purposes. The review of 50 studies found the association between total PCBs and breast cancer risk to be inconsistent. However, 19 studies linked certain PCBs to a higher breast cancer incidence. Similar to DTT, PCBs accumulate in the adipose tissue and in the food chain and can be excreted in breast milk.
The largest study of its type in the UK has identified differences in the immune response to COVID-19, between people with no symptoms, compared to those suffering a more serious reaction to the virus.
Researchers from the Wellcome Sanger Institute, Newcastle University, University College London, University of Cambridge, EMBL’s European Bioinformatics Institute (EMBL-EBI) and their collaborators within the Human Cell Atlas initiative, found raised levels of specific immune cells in asymptomatic people. They also showed people with more serious symptoms had lost these protective cell types, but gained inflammatory cells. These differences in the immune response could help explain serious lung inflammation and blood clotting symptoms, and could be used to identify potential targets for developing therapies.
The research, published today (20th April 2021) in Nature Medicine, is one of the only studies to include people who were asymptomatic. This large-scale collaborative study is part of the Human Cell Atlas* initiative to map every cell type in the human body, to transform our understanding of health, infection and disease.
So far, the COVID-19 global pandemic has caused millions of deaths and many more infections worldwide. Symptoms vary widely in severity and can range from a mild cough to severe respiratory distress, blood clots and organ failure. Several previous studies have highlighted a complex immune response in the blood, but until now the full coordinated immune response and how this differs between symptomatic and asymptotic patients had not been investigated in detail.
In a new study to understand how different immune cells responded to the infection, a large team of researchers came together to analyse blood from 130 people with COVID-19. These patients came from three different UK centres (Newcastle, Cambridge and London) and ranged from asymptomatic to critically severe.
The team performed single-cell sequencing from ~800,000 individual immune cells, along with detailed analysis of cell surface proteins and antigen receptors found on immune cells in the blood. They revealed differences in multiple types of immune cells that are involved in the body’s response to COVID-19.
A new study at Tel Aviv University found that the British variant (termed: B.1.1.7) of Covid-19 is 45% more contagious than the original virus. The researchers relied on data from about 300,000 PCR tests for Covid-19 obtained from the COVID-19 testing lab, which was established in collaboration with the Electra Group.
The new study was conducted by Prof. Ariel Munitz and Prof. Moti Gerlitz of the Department of Clinical Microbiology and Immunology at the Sackler Faculty of Medicine, together with Dr. Dan Yamin and PhD student Matan Yechezkel from the Laboratory for Epidemic Modeling and Analysis (LEMA) at the Department of Industrial Engineering, all at Tel Aviv University. The study’s results were published in the prominent scientific journal Cell Reports Medicine.
The Electra-TAU laboratory was established in March 2020, right after the outbreak of the first wave of the pandemic in Israel. To date, it has analyzed hundreds of thousands of tests from all over the country – from public drive-in test facilities, as well as programs targeting specific populations – such as ‘Shield for Fathers and Mothers’ which routinely ran tests in at-risk hotspots like retirement homes.
Prof. Ariel Munitz explains: “We use a kit that tests for three different viral genes. In the British variant, also known as B.1.1.7, one of these genes, the S gene, has been erased by the mutation. Consequently, we were able to track the spread of the variant even without genetic sequencing.”
According to Prof. Munitz, the data from the lab shows that the spread of the British variant was very rapid: On December 24, 2020 only 5% of the positive results were attributed to the British variant. Just six weeks later, in January 2021, this variant was responsible for 90% of Covid-19 cases in Israel. The current figure is about 99.5%.
“To explain this dramatic increase, we compared the R number of the SARS-CoV-2 virus with the R of the British variant. In other words, we posed the question: How many people, on the average, contract the disease from every person who has either variant? We found that the British variant is 45% – almost 1.5 times – more contagious.”
In the second stage of the study, the researchers segmented contagion by age groups. The results indicated that the turning point for the 60+ population compared to other age groups occurred two weeks after 50% of Israel’s 60+ population received their first vaccine shot.
“Until January we saw a linear dependence of almost 100% between the different age groups in new cases per 1,000 people,” says Dr. Dan Yamin. “Two weeks after 50% of the 60+ population received the first dose of the vaccine this graph broke sharply and significantly. During January a dramatic drop was observed in the number of new cases in the 60+ group, alongside a continued rise in the rest of the population. Simply put, since more than 90% of those who died from Covid-19 were over 60, we can say that the vaccine saved hundreds of lives – even in the short run.”
Moreover, the new study proves that active monitoring of at-risk populations works. “There is a threshold value for determining whether a specific test is positive or negative for the virus – with a lower value indicating a higher viral load,” says Prof. Munitz. “When we compared the threshold values of the different genes in 60+ residents of retirement homes with the values measured in 60+ persons in the general population, we saw significantly higher values in the retirement homes. This means that the viral load in retirement homes was lower compared to the rest of the population.
Since the residents of retirement homes are tested routinely, while other people are usually tested only when they don’t feel well or have been in contact with someone who had tested positive for the virus, we conclude that constant monitoring of at-risk populations is a method that works. It is important to emphasize: the relatively low viral load was found in retirement homes despite the fact that the British variant had already begun to spread in all populations. Consequently, we show that monitoring retirement homes, together with vaccination that gives precedence to vulnerable populations, prevent illness and mortality.”
Dr. Yemin concludes: “Due to crowded conditions, large households and age distribution in the Israeli population, the coronavirus had a more favorable environment for spreading in Israel compared to most Western countries. Our message to the world is that if with our problematic starting point a distinct decline was identified, other Western countries can certainly expect the curve to break – despite the high contagion of the British variant – with a dramatic drop in severe cases following the vaccination of 50% of the older population, alongside targeted testing at risk epicenters.”###
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Materials provided by Tel-Aviv University. Note: Content may be edited for style and length.
Researchers at the TUM have demonstrated a way to efficiently study molecular mechanisms of disease resistance or biomedical issues in farm animals. Researchers are now able to introduce specific gene mutations into a desired organ or even correct existing genes without creating new animal models for each target gene. This reduces the number of animals required for research..
CRISPR/Cas9 enables desired gene manipulations
CRISPR/Cas9 is a tool to rewrite DNA information. Genes can be inactivated or specifically modified using this method. The CRISPR/Cas9 system consists of two components.
The gRNA (guide RNA) is a short sequence that binds specifically to the DNA segment of the gene that is to be modified. The Cas9 nuclease, the actual “gene scissors,” binds to the gRNA and cuts the respective section of the target DNA. This cut activates repair mechanisms that can inactivate gene functions or incorporate specific mutations.
Healthy chickens and pigs with integrated gene scissors
“The generated animals provide the gene scissors, the Cas9 protein, right along with them. So all we have to do is to introduce the guide RNAs to get animals which have specific genetic characteristics,” explains Benjamin Schusser, Professor of Reproductive Biotechnology at the TUM. “The initial generation of these animals took about three years. Cas9 can now be used at all stages of animal development, since every cell in the body permanently possesses the Cas9 protein. We have been successfully able to utilize this technique in chicken embryos as well as in living pigs.”
The healthy chickens and pigs produced by the researchers thus possess the Cas9 nuclease in all organs studied. This is particularly useful in biomedical and agricultural research.
University of Minnesota Medical School researchers have offered new ways to think about the immune system thanks to a recent study published in Nature. Their research, which indicates organ tissues become increasingly immune throughout life, may begin to alter fundamental ideas regarding the rules of vaccination and the immune system’s function within the body.
Saythi Wijeyesinghe, PhD, the lead author on the study is a researcher in the Masopust Lab at the U of M Medical School, which focuses on T cell immunity. His research began with the goal to understand the lifespan of T cells in organ tissues, which are known to fight off viruses while also protecting from reinfection by the same virus.
“Historically, studies of the immune system have emphasized its renewable nature through bone marrow, lymphoid organs and blood. Our work shows how much this model fails to account for the many immune cells distributed throughout other organs of the body, where most infections and tumors arise,” Wijeyesinghe said. “What we found ends up painting a much broader picture of how the immune system accomplishes surveillance of the entire body for pathogens, tissue damage and tumors.”
The study’s major findings, include:- Antiviral T cells that reside in most organs of the body persist over time and in the face of extensive infectious exposures; – Unlike other organ systems, the immune system becomes increasingly immune throughout life, which is a natural response to accumulated microbial exposures over time; – Up to 25% of the cells in organs were immune cells, indicating that the immune system significantly contributes to the cellular makeup of the body; – And, along with antiviral T cells, most other immune cells are durably tissue-resident in organs as well. Wijeyesinghe hopes this study can further advance the ongoing change in how the broader scientific community conceptualizes the immune system and immune homeostasis.During this study, Wijeyesinghe also unexpectedly discovered how tissue-resident T cells may serve as the origin for memory T cells in blood. As a next step in this research, the Masopust Lab is developing new techniques to trace the fate of these immune cells, hoping to further dissect the relationship between blood-borne and tissue-based immunity.
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Materials provided by University of Minnesota Medical School. Original written by Angel Mendez. Note: Content may be edited for style and length.
