Culture

Brazil is the world leader in sweet orange production, but citrus cultivation in the region faces constant threats concerning the availability of water and the outbreak of diseases. New research published in the Journal of Applied Microbiology indicates that a fatty acid called hexanoic acid may help protect against one such problem: citrus canker, a bacterial infection that causes brownish eruptive lesions on the leaves, stems, and fruit of citrus trees.

Hexanoic acid might be a suitable substitute for chemicals used to protect citrus from bacterial infections. Investigators examined several mechanisms that might explain how hexanoic acid exerts its effects.

"The world population needs food, and agriculture based on chemical protection has guaranteed food in unimaginable amounts. More recently, people want safer food," said senior author Henrique Ferreira, DPhil, of the Sao Paulo State University, in Brazil. "Therefore, we are working hard to deliver safer alternatives to protect plants and minimize the impacts of old-school chemical defenses."

NEW YORK, NY (May 19, 2021)--A new study from Columbia University and an international team of researchers identifies multiple ways to achieve the same health benefits from exercise--as long as the exercise "cocktail" includes plenty of light physical activity.

"For decades, we've been telling people that the way to stay healthy is to get at least 30 minutes of exercise five days a week," says Keith Diaz, PhD, assistant professor of behavioral medicine and director of the exercise testing laboratory at the Center for Behavioral Cardiovascular Health at Columbia University Vagelos College of Physicians and Surgeons.

"But even if you're one of the few adults who can stick to this advice, 30 minutes represents just 2% of your entire day," says Diaz. "Is it really possible that our activity habits for just 2% of the day is all that matters when it comes to health?"

Diaz says that the recommendation about how much exercise to do may be insufficient depending on how individuals spend the rest of their waking day.

Previous studies tended to look at the impact of one type of activity or another in isolation. But each activity has either harmful or beneficial effects on health. "What we don't know is the best combination, or cocktail, of ingredients needed to prolong life," Diaz says.

Only through recent cheap and easy-to-use activity monitors, which can be worn by study participants throughout the day, have researchers been able to address the question.

With data from six studies that included more than 130,000 adults in the United Kingdom, United States, and Sweden, the authors used a technique called compositional analysis to determine how different combinations of activities--including moderate-to-vigorous exercise (such as brisk walking, running, or other activities that increase heart rate), light physical activity (such as housework or casual walking), and sedentary behavior--affect mortality.

Here are the main take-aways:

The benefits of 30 minutes of moderate-to-vigorous exercise depends on how you spend the rest of the day.

Although the current recommendation of 30 minutes per day of moderate-to-vigorous physical activity reduced the odds of an earlier death by up to 80% for some--those who sat for less than 7 hours--it did not reduce mortality risk for individuals who were very sedentary (over 11 to 12 hours per day), the researchers found.

"In other words, it is not as simple as checking off that 'exercise' box on your to-do list," says Diaz. "A healthy movement profile requires more than 30 minutes of daily exercise. Moving around and not remaining sedentary all day also matters."

"Getting 30 minutes of physical activity per day, or 150 minutes per week, is what's currently recommended, but you still have the potential to undo all that good work if you sit too long," says Sebastien Chastin, PhD, professor of health behaviour dynamics at Glasgow Caledonian University in Scotland and lead author of the study.

Light physical activity is more important than you think.

The research found that people who spent just a few minutes engaging in moderate-to-vigorous physical activity lowered their risk of early death by 30% as long as they also spent six hours engaging in light physical activity.

"Perhaps you're a parent with young kids and you simply can't get to the gym to exercise," Diaz says. "But you can still have a healthy movement profile as long as you move around a lot throughout the day as you tend to your everyday activities."

Sitting isn't as bad for your health as smoking, but it's still bad, Diaz says. "While there will always be sitting in our lives, as with most things in life, it's about sitting in moderation. The key is to find the right balance of sedentary time and physical activity."

A cocktail formula of 3 to 1 is best.

The researchers found that getting three minutes of moderate-to-vigorous activity or 12 minutes of light activity per hour of sitting was optimal for improving health and reducing the risk of early death.

"Our new formula gets at the right balance between moderate-to-vigorous exercise and sitting to help people lead a longer, healthier life," says Chastin. "The leftover hours should be spent moving around as much as possible and getting a good night's sleep."

Using this basic formula, the study found that multiple combinations of activities reduced the risk of early death by 30%:

55 minutes of exercise, 4 hours of light physical activity, and 11 hours of sitting

13 minutes of exercise, 5.5 hours of light physical activity, and 10.3 hours of sitting

3 minutes of exercise, 6 hours of light physical activity, and 9.7 hours of sitting

Although the researchers found that replacing sedentary time with just two minutes of moderate-to-vigorous exercise is more efficient than replacing it with light physical activity--two minutes of moderate-to-vigorous exercise is equivalent to four to 12 minutes of light physical activity--both have value.

"This is good news for people who may not have the time, ability, or desire to engage in formal exercise," Diaz says. "They can get health benefits from a lot of light physical activity and just a little moderate-to-vigorous activity."

"Our study shows that there is no one-size-fits-all approach to physical activity, and we get to choose which ones we like best," Diaz says. "It may be more important to mix a movement cocktail that includes a healthy dose of exercise and light activity to take the place of sitting."

Computed tomography -- CT scanning -- which combines a series of X-ray images taken from different angles around an organism and uses computer processing to create cross-sectional images of its bones, is providing new insight into an old initiative to characterize fishes in Africa's Lake Malawi.

The process, demonstrated in a new study using the high-resolution X-ray computer system in Penn State's Center for Quantitative X-Ray Imaging, is important because it will lead to the identification and management of more of the fish species in Africa's second largest lake, according to lead researcher Jay Stauffer Jr., distinguished professor of ichthyology in the College of Agricultural Sciences.

"Before they can effectively manage fish populations, they have to know what is there," he said.

Regarded by scientists as the most vibrant and diverse body of water in the world, Lake Malawi is home to between 800 and 1,000 species of colorful fish called cichlids; however, the lake is overfished by humans for food. As a result, about 10% of those species are believed to be endangered.

Located between Malawi, Tanzania and Mozambique, Lake Malawi is immense. It covers an area of more than 11,000 square miles and holds 7% of the world's available surface freshwater -- by comparison, appreciably more than Lake Erie.

"About half the species in the lake still haven't been described," said Stauffer, who has characterized, or discovered, more than 60 cichlid species himself. Since 1983, he has visited Lake Malawi for extended periods annually, collecting cichlid specimens while scuba diving.

After preservation, those specimens have been housed in the Penn State Fish Museum at Rock Springs, and approximately 35,000 are scheduled to be transferred to the National Research Institute of South Africa this year after COVID-19 restrictions are lifted. In the recent study, Stauffer and colleagues performed CT scans on selected specimens in the collection.

The entire head of each fish was scanned, and the researchers focused on the "morphology" -- analyzing the shape and profiles of the skulls and the structure and arrangement of teeth on the pharyngeal jaws and the oral jaws. This helps to determine a species' specialization to capitalize on certain food sources and to compete with other species.

"We chose species to scan that we knew had different feeding repertoires, and then we wanted to compare their head morphology with their species' feeding specializations to determine the relationships between morphology and behaviors," Stauffer said. "The purpose of this research was to show how observed behavioral traits of shallow-water species can be linked with morphological attributes using data collected from selected cichlids. Such associations can be used to predict behavior of deep-water or rare species, based on head morphology."

In findings recently published in Ecology and Evolution, the researchers reported that high-resolution CT scanning will enable scientists to infer life history and behavioral characteristics of rare or extinct fishes from a detailed examination of morphology and linkages between morphology and behavior observed in surviving species.

Stauffer and other scientists will use CT scanning as they continue to identify cichlids in Lake Malawi. The technology is nondestructive, he explained, so they can collect data from specimens in museum collections.

"High-resolution computed tomography permits us to view the internal morphology and examine areas that would otherwise be destroyed by dissection," he said. "It will be a great help to me because I'm going over there and spending four to six weeks a year at the institute, identifying fishes that are in its museum."

Many of those older museum specimens are surprising him, noted Stauffer, who is 70 and has no plans to retire. "I'm finding a lot of species I've never seen before in more than 30 years of diving in Malawi. I think they're probably extinct. I'd like to describe these species, and the CT scans will help me to make accurate guesses about what their behavior was in the lake."

Adrianus Konings, ichthyologist, photographer, and founder and publisher of Cichlid Press in El Paso, Texas; and Joshua Wisor, doctoral degree student in wildlife and fisheries science, contributed to this research.

SARS-CoV-2 has evolved to acquire mutations on the spike protein--the part of the virus that protrudes from its surface and latches onto cells to infect them--that enhance the coronavirus' ability to bind to human cells or evade antibodies. A new study from the Centers for Genomics and Systems Biology at New York University and NYU Abu Dhabi uses computational modeling to assess the biological significance of spike protein mutations, uncovering versions of the virus that bind more tightly or resist antibodies and offering a promising public health surveillance tool.

The study, which appears in the Journal of Molecular Biology, also suggests that these mutations on the spike protein are a key reason for the virus' rapid spread in parts of the world.

New and more transmissible COVID-19 variants have emerged in recent months, fueling surges of cases in countries like India and Brazil. As a public health measure, rapid surveillance methods are needed to determine the biological effects of variants and to help anticipate emerging infectious viral strains. But monitoring new variants is no small task; genome sequencing shows that the SARS-CoV-2 spike protein alone, for example, has about 5,000 possible variants.

"Screening such a large set of variants poses a tremendous challenge for conventional experimental methods," said Hin Hark Gan, a senior research scientist at NYU's Center for Genomics and Systems Biology and the study's lead author. "An advantage of computer-based modeling is that a hundred mutations can be readily assessed in a few days."

Gan and his colleagues turned to a computational method that models how the SARS-CoV-2 spike protein recognizes the ACE2 receptor--a protein on the surface of many types of cells--to gain entry into host cells. Studies of coronaviruses indicate that spike-ACE2 recognition is the basis for infection.

The researchers focused on screening the mutations located where the spike protein and ACE2 receptor meet. They assessed 1,003 mutation combinations in the spike and ACE2 proteins, including those resulting in the fast-spreading spike variants that have originated in Brazil, South Africa, the U.K., and India.

Their systematic assessment of variants uncovered that spike mutations that bind tightly to the ACE2 receptor occur in two clusters or mutation "hotspots" on the binding interface. These hotspots are located in structurally flexible regions, indicating that mutations that increase binding effectively reprogrammed the spike conformation to enhance its recognition of the ACE2 receptor.

The researchers also looked at single, double, and triple mutations in the critical spike interface region, which make up some of the recently emerged infectious variants. Their modeling analysis suggests the spike variants S477N, N501Y, and S477N + E484K and E484K + N501Y--fast-spreading double mutants found in Brazil, South Africa, the U.S., and U.K.--have increased binding to the ACE2 receptor relative to the original coronavirus that emerged in Wuhan.

Gan and colleagues observed that the E484K and E484Q mutations found in some recent fast-spreading variants are not only predicted to bind more strongly to ACE2 but have also been shown to confer antibody resistance. Neutralizing antibodies are produced in response to viral infection and target different sites on the spike protein to prevent the virus from invading host cells. This prompted the researchers to look at another factor contributing to viral transmission: antibody resistance of individual spike mutations.

In particular, the variant circulating in India has two mutations in the spike interface region: L452R and E484Q. This variant is not predicted to bind to the ACE2 receptor more tightly than the virus that originated in Wuhan, likely because the individual mutations have opposing effects (the L452R mutation binds less easily while the E484Q mutation binds more easily). Strikingly, however, both of these mutations are strong antibody evaders, a scenario not found in other recent variants.

"As more of antibody target sites become resistant to antibodies due to viral mutations, the efficacy of existing antibodies and vaccines may diminish," added Gan. "This scenario is a likely cause for the rapid spread of the variant in India."

The study not only provides explanations for the coronavirus' rapid spread--both mutations that enhance binding to human cells and help evade antibodies--but also points to a promising predictive tool in the ongoing public health fight against SARS-CoV-2.

"Our computational modeling method can be used as a real-time surveillance tool to screen for emerging infectious COVID-19 variants. It allows for a more timely response to emerging outbreaks and could be used to guide the development of new vaccines," said Kristin C. Gunsalus, professor of biology at NYU, faculty director of bioinformatics at NYU Abu Dhabi, and the study's senior author.

Press release - ESE statement: COVID-19 and endocrine and metabolic diseases. An updated statement from the European Society of Endocrinology

New expert statement confirms strong links between our hormones and COVID-19

The endocrine system is strongly involved in SARS-Cov-2 infection - so much so that evidence of an "endocrine phenotype" of COVID-19 has emerged, according to a statement by the European Society of Endocrinology (ESE) published in the journal Endocrine in April 2021. Leading endocrinology researchers looked into the evidence that has accumulated over the past year since the pandemic emerged, and consistently found evidence for links across a variety of endocrine conditions. This statement constitutes an update of a March 2020 statement that was of the earliest and most read pieces delineating the involvement of the endocrine system in COVID-19.

Dr Manel Puig from the Universitat Autònoma de Barcelona in Spain and first author on the statement said "the evidence is clear. The effect on hormones cannot be ignored in the context of COVID-19". He added "we need to be aware of the endocrine consequences of COVID-19 for patients with a known endocrine condition such as diabetes, obesity or adrenal insufficiency, but also for people without a known condition. Vitamin D insufficiency for example is very common, and the knowledge that this condition has emerged frequently in the hospitalized COVID-19 population and may negatively impact outcomes should not be taken lightly".

Dr Puig, together with Profs Marazuela, Yildiz and Giustina based in Madrid, Ankara and Milano looked at the available evidence with respect to COVID-19 across a number of endocrine conditions and related factors: diabetes, obesity, nutrition, hypocalcemia, vitamin D insufficiency, vertebral fractures, adrenal insufficiency, as well as pituitary/thyroid issues and sex hormones.

Diabetes has emerged as one of the most frequent comorbidities associated with severity and mortality of COVID-19, according to a rapidly increasing amount of published data on the incidence of COVID-19 in patients over the last year. Mortality in type 1 or type 2 diabetes has consistently increased during the year of pandemic - and evidence is emerging that a bidirectional relationship between diabetes and COVID-19 may exist, both in terms of worsening existing conditions and new onset of diabetes.

The researchers identified similar trends for patients with obesity. Obesity increases susceptibility to SARS-CoV-2 and the risk for COVID-19 adverse outcomes. They posit that nutritional management is important both for patients with obesity or undernourishment in order to limit their increased susceptibility and severity of infection. Vitamin D, calcium and bone are other areas showing a growing body of evidence that better monitoring and solutions for patients are needed in the context of COVID-19.

With regard to vaccination, the statement concludes that available evidence suggests COVID-19 vaccination should not be handled differently in patients with stable endocrine diseases. However, patients with adrenal insufficiency may need adjusted glucocorticoid treatment to address side effects such as fever. The authors suggest data from the field should be collected in an international database in order to form firm conclusions on this matter. They also present a decalogue for endocrinologists and patients with endocrine and metabolic conditions in the conclusions of the statement.

This knowledge highlights the important role endocrinologists will need to play in future research on COVID-19 and other global health issues.

While the APP protein is well-known for its key role in Alzheimer's disease, its contribution to healthy brain function, by contrast, has remained largely unknown until now. Recently, an international research team, led by molecular biologist Prof. Dr Ulrike Müller from Heidelberg University, gained new insights on the physiological functions of the APP protein family by using a mouse model lacking APP. The absence of APP during brain development was shown to result in the malformation of important brain regions implicated in learning and memory. Consequently, these mice were severely impaired in their learning abilities and exhibited autistic-like behaviour.

Alzheimer's disease is triggered by insoluble protein deposits in the brain, which aggregate around nerve cells to form plaques. These plaques consist mainly of small β-amyloid peptides (Aβ), which are a cleavage product of the amyloid precursor protein (APP). Aβ peptides inflict damage on nerve cells and ultimately lead them to their death. While the detrimental effect of Aβ peptides on neurons has been recognised for many years, little is known about the natural physiological functions of APP. According to the researchers, this non-pathological perspective is worthy of investigation considering the fact that APP, as well as two other closely-related proteins, is produced by most nerve cells in the brain - particularly in critical regions for learning and memory formation.

To investigate the role of the APP protein family in the development and functionality of the nervous system, Prof. Müller's research group used mice as a model organism, which had been genetically engineered to block the production of all APP family proteins. Close examination of their brains revealed that the loss of APP during brain development led to malformations in the layered structure of the hippocampus - an essential brain region for memory formation. "We observed that the absence of APP led to impaired neuronal wiring and a decrease in the number of synaptic connections. It also greatly reduced communication between nerve cells and severely affected the animal's performance in behaviour tests that assess learning," says Ulrike Müller, who heads the department of Functional Genomics at the Institute of Pharmacy and Molecular Biotechnology of Heidelberg University.

According to Prof. Müller, the team was surprised to discover that these disruptions in brain development also gave rise to behavioural changes that resembled those occurring in autism spectrum disorder. The mice displayed the characteristic recurring movement patterns and lack of interest in social interactions with other mice. "Our findings suggest that the APP family plays a crucial role in the normal development of the nervous system, learning, memory formation and social communication," explains the scientist. "In the future, these understandings may aid the development of novel therapeutics for Alzheimer's disease."

Individuals are often prescribed increasing numbers of medications as they age, and while many of these prescriptions are justifiable, some may be inappropriate. A recent analysis published in the British Journal of Clinical Pharmacology examined the results of all studies investigating associations between potentially inappropriate prescribing--which includes prescribing medications that may not produce benefits relative to harm and not prescribing medications that are recommended--and outcomes of older adults.

Potentially inappropriate prescribing was significantly associated with a range of health-related and system-related outcomes, including functional decline, falls, and hospital admissions due to drug-related side effects.

"Several decision support tools for quality prescribing are available; however, our analysis highlights that medication-related harm due to inappropriate prescribing remains problematic," said lead author Alemayehu Mekonnen, PhD, of Deakin University, in Australia. "A comprehensive assessment of medication use, especially during care transitions such as at hospital discharge, is an important task to reduce medication-related harm and associated healthcare costs."

By the end of the first year of the pandemic in metropolitan Stockholm, investigators estimate that one-fifth of adults in the region previously had COVID-19. The findings, which are published in the Journal of Internal Medicine, come from analyses of anti-viral antibody responses in healthy blood donors and pregnant women.

For the study, researchers examined blood from 2,600 blood donors and 2,500 pregnant women taken between March 14th 2020 and February 28th 2021. Blood donors and pregnant women had a similar rate of past infection, approaching 19% of the study group by the end of February 2021, shortly before mass vaccinations entered the adult population in Sweden. Nearly all (96%) positive samples screened displayed virus neutralizing responses comparable to those provoked by COVID-19 mRNA vaccines, suggesting that milder infections generally provide a degree of protection upon re-exposure to the virus that causes COVID-19.

"That nearly one in five individuals in these study groups had COVID-19 in the first year of the pandemic is striking. The data show how pervasive the virus is in Stockholm and highlight the need to reduce transmission to curtail viral evolution and prevent additional burden on the public healthcare system," said corresponding author Xaquin Castro Dopico, BVM&S, PhD, of the Karolinska Institute.

Unbound nickel atoms and other heavy elements have been observed in very hot cosmic environments, including the atmospheres of ultra-hot exoplanets and evaporating comets that ventured too close to our Sun or other stars. A new study conducted by JU researchers reveals the presence of nickel atoms in the cold gasses surrounding the interstellar comet 2I/Borisov. The team's finding is being published in Nature on 19 May 2021.

Interstellar comets and asteroids are precious to science because, unlike millions of minor bodies that formed in our Solar System, they originate from distant planetary systems. Until very recently, the existence of such cosmic vagabonds has merely been an interesting possibility, based on the fact that our Solar System ejected most of the primordial comets and asteroids into the interstellar space in its early days. The objects came to light in 2017 with the unexpected detection of the asteroidal 1I/'Oumuamua, followed by the discovery of the only known cometary interloper, 2I/Borisov, in 2019. "The scientific value of these objects is absolutely overwhelming, as they carry a plethora of information about their home planetary systems," says Piotr Guzik of the Jagiellonian University in Poland, author of the new study on 2I/Borisov.

The gasses around 2I/Borisov enabled astronomers to obtain the first precious insights into the chemical composition of an alien icy world. "We were curious what atoms and molecules make up the gasses around 2I/Borisov," explains study co-author Michał Drahus of the Jagiellonian University. There was only one way to find out. Over three nights in late January 2020, the Very Large Telescope of the European Southern Observatory in Chile was pointed at comet 2I/Borisov to collect the object's faint light. The incoming photons were directed to the X-shooter spectrograph, which split the light into its constituent wavelengths, enabling the identification of atoms and molecules through their characteristic spectral signatures.

Guzik and Drahus immediately scrutinized the incoming data and realized the existence of unforeseen spectral features. "At first, these features seemed impossible to identify with standard cometary species," says Guzik. After months of fruitless research, the team was close to giving up. But unexpectedly, a solution appeared on the horizon. "It was literally a 'Beautiful Mind' kind of situation, when the wavelengths of these lines materialized in a tabulated spectrum of comet Ikeya-Seki and pointed at atomic nickel," says Guzik, who first realized the surprising answer. "It didn't seem to make any sense," Drahus adds, "but it really did!"

The problem was that comet Ikeya-Seki passed so close to the Sun that the surrounding dust started evaporating, releasing various metals. The same mechanism could not apply to the cold comet 2I/Borisov, which passed too far from the Sun. "The nickel in 2I/Borisov seems to originate from a short-lived nickel-bearing molecule that is incorporated in the cometary ice and sublimates at low temperatures," explains Guzik. "This is really cool because heavy elements have not been observed in cold cosmic environments before." According to the study, nickel is not very abundant, accounting for less than 1 in 100,000 atoms in the gasses around 2I/Borisov.

HOUSTON - (May 19, 2021) - A new study from researchers at Rice University has found that bodily inflammation after the death of a spouse can predict future depression.

"Inflammation and future depressive symptoms among recently bereaved spouses" will appear in the June 2021 edition of the journal Psychoneuroendocrinology. Lead author Lydia Wu, a Rice psychology graduate student, and Christopher Fagundes, associate professor of psychology and principal investigator for the Biobehavioral Mechanisms Explaining Disparities (BMED) lab at Rice, led the study. The research team evaluated 99 people who lost their spouses within 2-3 months of the study on a number of factors, including physical and mental health, across a three-month period.

"Prior research has already linked bodily inflammation to a host of health issues, including cancer, memory issues, heart problems and depression," Wu said. "We were interested in how systemic inflammation affects the mental health of spouses after losing a loved one. In particular, can inflammation help us identify who will experience clinical levels of depression at a future point in time?"

The researchers found that widowed spouses who had higher levels of bodily inflammation right after the loss of their partners showed more severe symptoms of depression three months later than those with lower inflammation, especially if they didn't experience significant depression initially.

Fagundes said depression following the death of a spouse is normal, and research shows that undergoing psychotherapy right away can actually interfere with people's natural ability to cope.

"We know that most people are remarkably resilient," he said.

However, when depression is persistent or occurs six or more months after a spouse's death, it may be a sign that clinical intervention is needed, Fagundes said.

"Until this study, it was difficult to know who was at risk for these persistently high levels of depression and grief until the six-month mark," he said. "This study identifies a potential biomarker that could help us predict who is at greatest risk for long-term repercussions of loss."

"This information makes early intervention possible," Wu said. "We can identify at-risk bereaved persons and introduce them to interventions early on to improve their mental health."

The researchers said more research is needed to determine who might be at greatest risk.

PITTSBURGH, May 19, 2021 - Specialized immune cells that accumulate in the brain in the days and weeks after a stroke promote neural functions in mice, pointing to a potential immunotherapy that may boost recovery after the acute injury is over, University of Pittsburgh School of Medicine neurologists found.

The study, published today in the journal Immunity, demonstrated that a population of specialized immune cells, called regulatory T (Treg) cells, serve as tissue repair engineers to promote functional recovery after stroke. Boosting Treg cells using an antibody complex treatment, originally designed as a therapy after transplantation and for diabetes, improved behavioral and cognitive functions for weeks after a stroke in mice compared to those that did not receive the antibody complex.

"The beauty of this treatment is in its wide therapeutic window," said senior author Xiaoming Hu, M.D., Ph.D., associate professor in the Department of Neurology at Pitt's School of Medicine. "With most strokes, you have four and a half hours or less when you can give medication called tPA to reopen a blocked blood vessel and expect to rescue neurons. We're excited to identify a mechanism that may promote brain recovery by targeting non-neuronal cells well after this window closes."

Previous research in stroke has been focused on developing new drugs to reduce neuronal death. And whereas these acute stroke treatments quickly lose effectiveness after neurons die, Treg cells remain active for weeks after the injury.

True to their name, Treg cells are immune cells that regulate the immune response, including curtailing excessive inflammation that could harm more than help. Hu and her colleagues observed that the levels of Treg cells infiltrating the brain began to increase about a week after a stroke and continued increasing up to five weeks later. So, they did multiple tests in mice after they'd had strokes, paying particular attention to the brain's white matter--which is the brain tissue through which neurons pass messages, turning thoughts into actions, like lifting food to your mouth or saying the name of an object you're looking at.

Mice that were genetically unable to produce Treg cells fared worse than mice with a robust Treg cell response. Interestingly, it was only in the latter phases of stroke recovery that the Treg cell-depleted mice suffered impairments in white matter integrity and behavioral performance compared to mice with a normal Treg cell response.

Additionally, when normal mice were given an antibody complex called "IL-2:IL-2Ab" to boost their Treg cell levels after a stroke, their white matter integrity improved even more and neurological functions were rescued over the long term. The mice with more Treg cells had an easier time moving and had better memories, allowing them to navigate mazes faster after a stroke than their non-treated counterparts.

"This strongly suggests that, rather than working to preserve white matter structure and function immediately after a stroke, Treg cells influence long-term white matter repair and regeneration," said Hu, also a member of the Pittsburgh Institute of Brain Disorders and Recovery and a U.S. Department of Veterans Affairs (VA) investigator. "Our findings pave the way for a therapeutic approach to stroke and other neurological disorders that involve excessive brain inflammation and damage to the white matter. Treg cells appear to hold neurorestorative potential for stroke recovery."

Hu stressed that there are still many hurdles to cross before Treg cells could be used in humans for stroke recovery. Namely, research is needed to determine the best way to boost the number of Treg cells in stroke victims. This could be done by improving IL-2:IL-2Ab so that it better stimulates production of Treg cells with fewer side effects, or a personalized therapy could be developed where some cells are taken from an established Treg cell bank and used to grow custom Treg cells in the lab, which could then be infused back into the patient.

The yeast Candida albicans can cause itchy, painful urinary tract and vaginal yeast infections. For women in low-resource settings who lack access to healthcare facilities, these infections create substantial social and economic burdens. Now, researchers reporting in ACS Omega have developed color-changing threads that turn bright pink in the presence of C. albicans. When embedded in tampons or sanitary napkins, they could allow women to quickly and discreetly self-diagnose vulvovaginal yeast infections, the researchers say.

According to the Mayo Clinic, about 75% of women will experience a yeast infection, or vulvovaginal candidiasis, at least once in their lifetime. Although women in high-resource areas can easily be diagnosed with a vaginal swab at their doctor's office and then treated with an antifungal medication, many women throughout the world lack access to basic healthcare facilities. Moreover, in some resource-limited areas, societal taboos cause women to feel shame or embarrassment about the symptoms, which prevents them from seeking a doctor's care. Therefore, Naresh Kumar Mani and colleagues wanted to develop an inexpensive method that could be integrated into menstrual hygiene products, allowing women to quickly, easily and discreetly self-diagnose yeast infections.

The researchers began with ordinary multifilament cotton threads purchased at a local craft store. To increase the wicking properties of the threads, the team treated them with a heptane solution that removed waxes and binders added during manufacturing. Then, the threads were coated with a molecule called L-proline β-naphthylamide (PRO) -- the substrate for an enzyme secreted by C. albicans -- and embedded in the inner layers of sanitary napkins and pads. When the researchers added simulated vaginal fluid spiked with C. albicans and an indicator solution, the spots of the napkins or pads containing yeast changed to a bright pink color. The detection time was only 10 minutes, compared with 24-72 hours for conventional tests. In addition, the new test costs only 22 to 28 cents per napkin or tampon, and it could easily be adapted to simultaneously detect other pathogens, such as bacteria that also can cause urinary tract infections, the researchers say.

Researchers have found the elusive genetic element controlling the elongated grains and glumes of a wheat variety identified by the renowned botanist Carl Linnaeus more than 250 years ago.

The findings relating to Polish wheat, Triticum polonicum, could translate into genetic improvements and productivity in the field.

Wheat, in bread, pasta, and other forms, is a vital energy and protein source for humans. Each individual grain is nestled within the glumes and other leaf-like organs called lemma and palea which affect the grain's final size, shape, and weight.

Characterised by Linnaeus in 1762, Polish wheat has long grains, glumes, and lemmas. Previous research showed that all these characteristics were controlled by one gene, but which one among wheat's complex genome has been unclear.

Researchers at the John Innes Centre used genomic, field-based, and biotechnological approaches to identify the responsible molecular component as VRT-A2, a member of the MADS-box family of transcription factors which act as genetic switches controlling protein synthesis.

Dr Nikolai Adamski, first author of the paper, said: "These results highlight how changes in expression of transcription factors can impact on important agronomic traits for major crops such as wheat. Our goal is to use this knowledge to help deliver genetic solutions to improve wheat productivity."

The team identified a small sequence rearrangement leading to misexpression of VRT-A2 in different tissues at several growth stages of wheat. This variation is responsible for the longer grains and floral organs found in Polish wheat.

Introducing the VRT-A2 version from Polish wheat into a UK bread wheat cultivar led to higher grain weight, size, and test weight (a measure of the density of the grain) but did not increase yield in UK environments.

Professor Cristobal Uauy, a group leader at the John Innes Centre, explained the broader significance of the research: "Every day, each person on the planet eats the grains of the equivalent of 50 wheat plants. With a growing demand for wheat, and against the backdrop of climate change, it is urgent that we increase wheat production sustainably. As part of this effort, understanding the genetic control of grain size and weight is extremely relevant to deliver genetic solutions."

The experiments also revealed a strong positive correlation between VRT-A2 expression levels and the magnitude of its effects on grain length and floral organ size.

In Polish wheat, the VRT-A2 gene carries a small rearrangement in its first intron - a genetic sequence that does not code for protein, but instead is important for regulating the gene's expression. The researchers suggest that this rearrangement was caused by errors in DNA repair following a double strand break.

Next the research team aim to understand how the VRT-A2 expression pattern is controlled by the sequence rearrangement in the first intron of the gene. They also plan to identify the downstream genes affected by VRT-A2 misexpression.

Scientists, governments and corporations worldwide are racing against the clock to fight climate change, and part of the solution might be in our soil. By adding carbon from the atmosphere to depleted soil, farmers can both increase their yields and reduce emissions. A cover story in Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society, explores what it would take to get this new practice off the ground.

Historically, agricultural soil has provided crops with the nutrients needed to grow, write Senior Editors Melody Bomgardner and Britt Erickson. Today, most soil is considered degraded, leading farmers to rely on fertilizer, irrigation and pesticides, all of which are costly. Scientific advancements in agriculture have shown that adding organic matter, like decaying plants and microbes, to soil can sequester carbon emissions and replenish soil nutrients, which benefits the farmer and the environment. Companies are also offering incentives to farmers who adopt sustainable practices, such as offering marketable carbon credits to those who help offset greenhouse gas emissions by utilizing techniques like low-till farming and planting cover crops.

Although these agricultural practices show great promise, experts say science needs to verify carbon sequestration's impact on greenhouse gas emissions. Companies and environmental groups alike have developed standards and methods to measure the impact of agricultural practices that earn carbon credits, and new technologies utilizing machine learning and artificial intelligence will help with these efforts. Governments are also looking to play a role in encouraging sustainable agriculture as a means to fight climate change, with the U.S. Congress considering legislation that would allow the U.S. Department of Agriculture to participate in carbon markets and set standards at the federal level. The European Union is also promoting carbon farming to its member states and will launch a carbon market later this year. While experts caution that carbon farming will not replace pollution regulations, the financial incentives and other benefits make it a strong model to follow.

Protein intake is more important than protein source if the goal is to gain muscle strength and mass. This is the key finding of a study that compared the effects of strength training in volunteers with a vegan or omnivorous diet, both with protein content considered adequate.

In the study, which was conducted by researchers at the University of São Paulo (USP) in Brazil, 38 healthy young adults, half of whom were vegans and half omnivores, were monitored for 12 weeks. In addition to performing exercises to increase muscle strength and mass, the volunteers followed either a mixed diet with both animal and plant protein, or an entirely plant-based diet, both with the recommended protein content (1.6 gram of protein per kilogram of body weight per day). At the end of three months, there was no difference between vegans and omnivores in terms of muscle strength and mass increase.

“Like any other protein in our organism, such as the proteins in our skin and hair cells, which die and are renewed, our muscles undergo synthesis and breakdown every day. Diet [protein intake] and exercise are the main protein balance regulators, favoring synthesis over breakdown,” said Hamilton Roschel, last author of the published study. Roschel is a University of São Paulo professor affiliated with both USP’s Sports and Physical Education School (EEEE) and Medical School (FM). He also heads the Applied Physiology and Nutrition Research Group jointly run by EEEE-USP and FM-USP.

Protein sources are characterized primarily on the basis of essential amino acids, especially leukin, which plays a key role in anabolic stimulation of skeletal muscles. “Animal protein has more leukin than plant protein. Leukin is an essential amino acid in the anabolic stimulus signaling process. A plant-based diet is often thought to contain less leukin and hence trigger less anabolic stimulation, potentially affecting vegans’ capacity for muscle mass gain,” Roschel said.

The study is published in Sports Medicine and resulted from the master’s research of Victoria Hevia-Larraín, with support from FAPESP.

The study innovated by including a clinical analysis of the effects of protein source quality on muscle adaptation in vegans as compared with omnivores, since most research on the topic to date has focused on the acute anabolic response of muscles to protein intake under laboratory conditions and not on muscle mass as such. “Our findings show that there is no impairment of muscle mass gain for young adult vegans if they ingest the right amount of protein. In fact, the outcome of both diets was the same in this respect,” Roschel said.

However, the researchers stress that, for the purposes of experimental control, protein intake was made the same in both diets by means of protein supplements. Omnivores and vegans were given milk serum protein isolate or soy protein respectively in accordance with individual dietary needs in order to attain the targeted protein intake.

“In clinical practice, we know foods of animal origin generally have a higher protein content,” Roschel said. “Meat, milk and eggs contain more protein per gram than rice and beans, for example. In a clinical application with plant-based foods as the sole protein source, vegans would need to ingest a large amount of food to obtain the same amount of protein. In some specific cases, this could be a major challenge.”

The protein source (mixed or plant-based diet) made no difference, provided each subject received an adequate amount of protein. “This result corroborates other data in the literature showing that a vegan diet can absolutely be complete if it is properly planned and executed,” Roschel said. “Previous studies suggest it can even be healthier than an omnivorous diet. For this to be the case, however, it requires appropriate nutritional counseling and education regarding people’s choices in restricting their intake to plant-based sources.”

Another point noted by Roschel is that the subjects were healthy young adults, and the results might be different for older people or subjects with health problems. “Aging entails a phenomenon known as anabolic resistance, meaning a suboptimal anabolic response to the stimuli provided by diet and exercise compared with young people. Optimal response is possible in older people only if their protein intake is higher than that of the average healthy youngster. So we should be cautious about generalizing our findings for the entire population.”

The article “High-protein plant-based diet versus a protein-matched omnivorous diet to support resistance training adaptations: a comparison between habitual vegans and omnivores” (doi: 10.1007/s40279-021-01434-9) by Victoria Hevia-Larraín, Bruno Gualano, Igor Longobardi, Saulo Gil, Alan L. Fernandes, Luiz A. R. Costa, Rosa M. R. Pereira, Guilherme G. Artioli, Stuart M. Phillips and Hamilton Roschel can be retrieved from: link.springer.com/article/10.1007/s40279-021-01434-9.

Journal

Sports Medicine

DOI

10.1007/s40279-021-01434-9