Culture

SAN FRANCISCO - Promising new therapies for food allergies are on the horizon, including an experimental immunotherapy awaiting federal approval that enables people who are very allergic to eat peanut protein without suffering serious side effects.

Good news, right?

As it turns out, the idea of a child who is highly allergic to a specific food eating that same food item makes kids with lifelong food allergies and their parents a bit queasy.

"It's a very big paradigm shift. From diagnosis, children are told to avoid their food triggers at all cost. But now they may be counseled to approach the very thing that scares them, put it in their body and see what happens," says Linda Herbert, Ph.D., an assistant professor in Children's Division of Psychology and Behavioral Health.

"On the flip side, these new protections could reduce long-term anxieties, replacing daily anxiety about accidental exposure with a newfound sense of empowerment. Either way, a lot of families will need support as they try these new treatments that enable them to ingest a food allergen daily or wear a patch that administers a controlled dose of that food allergen," Herbert says.

She will discuss food allergy treatments in the pipeline and families' psychosocial concerns related to daily life as she presents a research update during the American Academy of Allergy, Asthma & Immunology (AAAAI) 2019 Annual Meeting. A select group, including Herbert, has been recognized with an AAAAI Foundation Heritage Lectureship, which honors distinguished AAAAI members with a special lecture and plaque.

Herbert's symposium targets allied health professionals at the annual meeting, including psychologists, dietitians and nurse practitioners who attend to a host of psychosocial concerns felt by families affected by allergies to foods like eggs, nuts and cow's milk.

"When patients arrive for outpatient therapy, they feel anxious about being safe when they're out in public. They have anxieties about their children feeling safe at school as well as managing restaurant meals. They explain difficulties being included in social events like birthday parties, field trips and shared vacations," Herbert says. "Some families restrict social activities due to stress and anxiety."

Children's National Health System takes a multidisciplinary approach for complex conditions like food allergies, she says, combining the expertise of psychologists, medical providers, research nurses, clinical nurses, registered dietitians and other allied health professionals.

"When we all communicate, we can see the complete picture. It strengthens the care that the child receives, and it's especially powerful that it can happen all at once - rather than going to multiple appointments," she adds.

During such group huddles, the team agrees on a plan together that is communicated to the family. One ongoing challenge is that one-third of school children with food allergies are bullied or teased.

"A lot of parents don't necessarily know to ask or how to ask. I frequently suggest that clinicians discuss peer concerns more in clinic."

Opioid-related deaths nationwide jumped fourfold in the last two decades, and the epidemic has made major inroads in the Eastern states, according to a new study by researchers at the Stanford University School of Medicine, Harvard University and the University of Toronto.

"Although opioid-related mortality has been stereotyped as a rural, low-income phenomenon concentrated among Appalachian or Midwestern states, it has spread rapidly, particularly among the Eastern states," the study said.

The researchers found the highest rates of opioid-related deaths occurred in eight states: Connecticut, Illinois, Indiana, Massachusetts, Maryland, Maine, New Hampshire and Ohio. Two states, Florida and Pennsylvania, had opioid-related mortality rates that were doubling every two years. The mortality rate from opioids has increased the fastest in the District of Columbia, more than tripling every year since 2013, the researchers found.

The study's findings will be published Feb. 22 in JAMA Network Open. Mathew Kiang, ScD, a postdoctoral scholar at Stanford, is the lead author. The senior author is Monica Alexander, PhD, assistant professor of sociology and statistical sciences at the University of Toronto.

'More potent than they expected'

Synthetic opioid deaths now outnumber heroin deaths, which suggests synthetics, such as as fentanyl, have contaminated the production process of other illegal drugs, like cocaine and methamphetamines, and is no longer limited to heroin, Kiang said.

"People aren't aware their drugs are laced and more potent than they expected, putting them at higher risk of overdose," Kiang said.

The research, which is based on data from the National Center for Health Statistics and the U.S. Census, suggests the opioid epidemic has evolved as three waves, based on the types of opioids associated with mortality:

The first wave of opioid-related deaths, from the 1990s until about 2010, was associated with prescription painkillers.

The second wave, from 2010 until recently, was associated with a large increase in heroin-related deaths.

The third and current wave, which began around 2013, involves a rapid increase in deaths associated with illicitly manufactured synthetic opioids, such as tramadol and fentanyl.

"The evolution has also seen a wider range of populations being affected, with the spread of the epidemic from rural to urban areas and considerable increases in opioid-related mortality observed in the black population," the study says.

The Centers for Disease Control and Prevention reports that African-Americans experienced the largest increase in opioid overdose deaths among any racial group from 2016 to 2017, with a 26 percent surge.

"The identification and characterization of opioid 'hot spots' -- in terms of both high mortality rates and increasing trends in mortality -- may allow for better-targeted policies that address the current state of the epidemic and the needs of the population," the researchers wrote.

States are trying to combat the epidemic by enacting policies, such as restricting the supply of prescription painkillers and expanding treatment and access to the overdose-reversing drug naloxone.

"Treating opioid use disorder should be our top priority to curb the problem," Kiang said. "Similarly, we have the ability to counteract the effects of an overdose. These lifesaving drugs should be easily accessible and widely available."

ROCHESTER, Minn. -- The good news is that physician burnout appears to be improving, along with indicators for physician well-being. However, physicians remain at high risk for burnout, depression and depersonalization, compared to other professionals. Those are the updated findings from Mayo Clinic researchers and their collaborators that are published in Mayo Clinic Proceedings.

"This is good news. It shows that burnout is being addressed nationally and programs are having some impact," says Lotte Dyrbye, M.D., Mayo Clinic researcher and senior author of the paper. "Clearly more organizational change and more research is needed to sustain this trajectory."

Researchers from Mayo Clinic, the American Medical Association and Stanford University collaborated in the national survey of physicians across more than 20 specialties to assess any changes between the previous study in 2014 and the original survey in 2011. While burnout varies by specialist, overall reported levels of burnout and satisfaction with work-life integration improved between 2014 and 2017 -- but only to 2011 levels. The researchers say individual and organizational efforts have improved the situation, but more work needs to be done.

Burnout encompasses many aspects but includes the areas of emotional exhaustion, depersonalization, distress and depression. Extreme cases of burnout can lead to medical errors affecting patients, job loss and suicide. Survey responders say the demands of updating electronic health records are a major factor in burnout. These demands limit the time physicians can spend with patients, and that affects career satisfaction.

More than 30,000 physicians were invited to participate in the electronic survey. Roughly 17 percent (5,197) responded, and a second attempt to reach nonrespondents gained 248 more participants. Questions mirrored those on the previous surveys.

Researchers say the reason for the change may be due to physicians adapting to the new work environments over the three-year period. Also, much progress may be attributed to interventional programs to stem burnout in hospitals and other facilities. Conversely, they say the indicators may have improved because many distressed physicians have left the profession.

A new study by Johns Hopkins Bloomberg School of Public Health researchers found that U.S.-based patient advocacy organizations received a disproportionate amount of contributions made by the world's 10 largest pharmaceutical companies in 2016.

The study assessed contributions to patient advocacy groups in seven countries and the United Kingdom and found that U.S.-based patient advocacy organizations received 74 percent of total contributions in 2016, or an estimated $88 million dollars.

Patient advocacy organizations are nonprofit groups that focus on specific medical conditions. They are found in almost every industrialized country and seek to raise awareness, lobby for research and treatment options as well as provide patient and caregiver education, advocacy and support services.

The study was published online February 21, 2019 in the American Journal of Public Health.

"Patient advocacy groups have an important role when they testify in Congress, at the Food and Drug Administration, the Centers for Medicare & Medicaid Services and other government agencies," says senior co-author Gerard Anderson, PhD, professor in the Bloomberg School's Department of Health Policy and Management. "It is important for policymakers to understand the funding sources for these organizations."

The report reveals a patchwork of disclosure levels among countries, with only six of the 10 drug companies disclosing their financial donations to U.S.-based patient advocacy organizations in 2016. This disclosure gap suggests that the total amount of contributions to U.S.-based patient groups was even higher, as four companies did not disclose their U.S. contributions.

In contrast, the study found that all 10 companies disclosed their 2016 financial transactions to patient advocacy organizations in France, Germany and the United Kingdom, which encourage or require such disclosure.

The authors say the findings underscore the importance of transparency given the growing role of patient advocacy groups, particularly in the U.S., and recommend moving to greater disclosure, either voluntary or regulatory.

"Patient advocacy groups have grown exponentially in the last 10 years, but the magnitude of pharmaceutical industry funding to them across countries has not been measured before," says So-Yeon Kang, MPH, MBA, lead study author and research associate in the Bloomberg School's Department of Health Policy and Management. "Patient advocacy organizations are supposed to represent their constituents' interests. Transparency is critical to avoid conflict of interests."

For their study, the researchers identified the world's 10 largest pharmaceutical companies based on total global revenue in 2016: Pfizer, Novartis, Roche, Sanofi, Merck, AbbVie, Amgen, Gilead, Janssen and GlaxoSmithKline. Together they accounted for 41 percent of pharmaceutical industry revenue that year. The study authors then researched disclosures for contributions from these 10 companies to patient advocacy groups based in Canada, France, Germany, Italy, Japan, Spain, the United Kingdom and the U.S. The researchers collected financial information from pharmaceutical websites, funding reports and other public-facing documentation, such as annual reports.

In France, Germany and the United Kingdom, where all 10 pharmaceutical companies disclosed financial contributions to patient groups, the researchers note that in addition to robust regulatory frameworks, information about disclosures was easily accessible and content was consistent.

Other countries, including the United States, had varying amounts of disclosed information available. The researchers report that they encountered several barriers with data collection in the U.S., including different reporting styles and mixed information with various types of grants.

The six companies that disclosed contributions to U.S. groups contributed $120 million in patient advocacy funding to the study countries--$88 million to U.S. groups and $32 million to groups in the remaining six countries and the U.K.

Researchers also wanted to understand the relationship between patient advocacy groups and the pharmaceutical market in the respective countries. The researchers did not find any association between companies' contributions to a country's patient advocacy groups and the country's population, pharmaceutical revenue or GDP.

"If financial support to patient advocacy organizations is really about patient education, you would expect the funding to be the same in each country," says Anderson. "This analysis shows that there's no correlation and something more than patient education influences the level of patient advocacy organization support in a country."

The disproportionate amount of funding to U.S. patient advocacy organizations and unregulated financial disclosures highlight the importance of establishing reporting guidelines.

"Legislative actions, such as expanding the Physician Payment Sunshine Act, would insure universal disclosure compliance," says Kang. "But as an intermediary step, the industry should consider adopting a voluntary disclosure requirement at the trade association level. They already have it in Europe. Why not in the U.S.?"

Increased transparency, the authors say, would help address potential conflicts of interest associated with the pharmaceutical industry's support. "The U.S. has one of the most robust drug regulation processes," explains Anderson. "It is often the first country to adopt prescription drugs and therefore has a significant influence on a product's performance in a global market. Regulation is important because these groups can be influenced by the money they receive from drug companies."

The remarkable properties of a recently-discovered squid protein could revolutionize materials in a way that would be unattainable with conventional plastic, finds a review published in Frontiers in Chemistry. Originating in the ringed teeth of a squid's predatory arms, this protein can be processed into fibers and films with applications ranging from 'smart' clothes for health monitoring, to self-healing recyclable fabrics that reduce microplastic pollution. Materials made from this protein are eco-friendly and biodegradable, with sustainable large-scale production achieved using laboratory culture methods.

"Squid proteins can be used to produce next generation materials for an array of fields including energy and biomedicine, as well as the security and defense sector," says lead author Melik Demirel, Lloyd and Dorothy Foehr Huck Endowed Chair in Biomimetic Materials, and Director of Center for Research on Advanced Fiber Technologies (CRAFT) at Penn State University, USA. "We reviewed the current knowledge on squid ring teeth-based materials, which are an excellent alternative to plastics because they are eco-friendly and environmentally sustainable."

Squid ring teeth are all-rounders

As humanity awakens to the aftermath of a 100-year party of plastic production, we are beginning to heed nature's warnings - and its solutions.

"Nature produces a variety of smart materials capable of environmental sensing, self-healing and exceptional mechanical function. These materials, or biopolymers, have unique physical properties that are not readily found in synthetic polymers like plastic. Importantly, biopolymers are sustainable and can be engineered to enhance their physical properties," explains Demirel.

The oceans, which have borne the brunt of plastic pollution, are at the center of the search for sustainable alternatives. A newly-discovered protein from squid ring teeth (SRT) - circular predatory appendages located on the suction cups of squid, used to strongly grasp prey - has gained interest because of its remarkable properties and sustainable production.

The elasticity, flexibility and strength of SRT-based materials, as well as their self-healing, optical, and thermal and electrical conducting properties, can be explained by the variety of molecular arrangements they can adopt. SRT proteins are composed of building blocks arranged in such a way that micro-phase separation occurs. This is a similar situation to oil and water but on a much smaller, nano-scale. The blocks cannot separate completely to produce two distinct layers, so instead molecular-level shapes are created, such as repeating cylindrical blocks, disordered tangles or ordered layers. The shapes formed dictate the property of the material and scientists have experimented with these to produce SRT-based products for a variety of uses.

In the textiles industry, SRT protein could address one of the main sources of microplastic pollution by providing an abrasion-resistant coating that reduces microfiber erosion in washing machines. Similarly, a self-healing SRT protein coating could increase the longevity and safety of damage-prone biochemical implants, as well as garments tailored for protection against chemical and biological warfare agents.

It is even possible to interleave multiple layers of SRT proteins with other compounds or technology, which could lead to the development of 'smart' clothes that can protect us from pollutants in the air while also keeping an eye on our health. The optical properties of SRT-based materials mean these clothes could also display information about our health or surroundings. Flexible SRT-based photonic devices - components that create, manipulate or detect light, such as LEDs and optical displays, which are typically manufactured with hard materials like glass and quartz - are currently in development.

"SRT photonics are biocompatible and biodegradable, so could be used to make not only wearable health monitors but also implantable devices for biosensing and biodetection," adds Demirel.

No squid was harmed in the making of this film

One of the main advantages of SRT-based materials over synthetic materials and plastics made from fossil fuels are its eco-credentials. SRT proteins are cheaply and easily produced from renewable resources and researchers have found a way of producing it without catching a squid.
"We don't want to deplete natural squid resources and hence we produce these proteins in genetically modified bacteria. The process is based on fermentation and uses sugar, water, and oxygen to produce biopolymers," explains Demirel.

It is hoped that the SRT-based prototypes will soon become available more widely, but more development is needed.

Demirel explains, "Scaling up these materials requires additional work. We are now working on the processing technology of these materials so that we can make them available in industrial manufacturing processes."

Researchers in Virginia Commonwealth University's Department of Physics have discovered that a technique known as nanopore sensing can be used to detect subtle changes in clusters, or extremely small chunks of matter that are bigger than a molecule but smaller than a solid.

"Nanopores act as extremely small volume sensors that are on the order of a few nanometers a side," said Joseph Reiner, Ph.D., an associate professor of experimental biophysics and nanoscience in the College of Humanities and Sciences. "This size scale allows us to observe when the cluster changes size by a single ligand molecule. The ability to detect these changes in real time -- as they happen -- to a single cluster particle is the new and exciting thing here."

The discovery is described in a paper, "Ligand-induced Structural Changes of Thiolate-capped Gold Nanoclusters Observed with Resistive-pulse Nanopore Sensing," by Reiner and physics professor Massimo F. Bertino, Ph.D., along with VCU students Bobby Cox, Peter Wilkerson and Patrick Woodworth, published in the Journal of the American Chemical Society.

"This is new because there really aren't many ways to detect these changes on a single particle in real time," Reiner said. "This opens the door to observe all kinds of interesting phenomenon on nanosurfaces, which is an area of great interest to many chemists in both applied and pure research areas."

The research sheds new light on the activity of clusters, which are extremely reactive objects and are considered to be interesting for catalysis, or the acceleration of a chemical reaction by a catalyst.

"Understanding how molecules behave on a nanocluster helps [our] understanding of their catalytic properties," Bertino said. "To date, people thought that molecules were kind of stationary on cluster surfaces. Our experiments show that molecules, instead, change their configuration and position at a very fast pace. This opens new perspectives for the chemistry of these things."

The team's findings could lead to exciting new discoveries, Bertino said.

"There are several possible alleys that open now. One is to look at cluster growth. Nobody has a good grasp on how these things come into existence. Another one is to help tune their properties," he said. "To date, people grow these things and make them reactive, but it's not always clear how this happens. Essentially, darts are thrown at the problem and one hopes that one of them sticks. This work allows us to look at a single cluster of a well-defined size and lets us mess with it by varying one parameter at a time."

By getting a better look at these clusters and how they behave, the researchers hope to gain a better understanding of how catalysts could be improved for more efficient drug discovery and synthesis.

About VCU and VCU Health

Virginia Commonwealth University is a major, urban public research university with national and international rankings in sponsored research. Located in downtown Richmond, VCU enrolls more than 31,000 students in 217 degree and certificate programs in the arts, sciences and humanities. Thirty-eight of the programs are unique in Virginia, many of them crossing the disciplines of VCU's 11 schools and three colleges. The VCU Health brand represents the VCU health sciences academic programs, the VCU Massey Cancer Center and the VCU Health System, which comprises VCU Medical Center (the only academic medical center and Level I trauma center in the region), Community Memorial Hospital, Children's Hospital of Richmond at VCU, MCV Physicians and Virginia Premier Health Plan. For more, please vcu.edu and vcuhealth.org.

The use of alcohol and tobacco is closely linked to several diseases, and is a contributing factor in many deaths.

A recent study using data from 1.2 million people has now been published in the journal Nature Genetics. Several research groups around the world are involved, among them a group from the Nord-Trøndelag Health Study (HUNT) and the K.G. Jebsen Center for Genetic Epidemiology.

"We discovered several genes associated with an increased use of alcohol and tobacco. We also looked at the correlation between these genes and the risk of developing various diseases and disorders," says Professor Kristian Hveem at the HUNT Research Centre. He is also the head of the Jebsen Center and one of the study's co-authors.

Genes and diseases

The research groups discovered a total of 566 gene variants at 406 different sites in the human genetic material that can be linked to the use of alcohol or tobacco. One hundred fifty of these sites are linked to the use of both tobacco and alcohol.

Alcohol consumption was measured in terms of the number of standard alcohol units. Tobacco use was measured in the number of cigarettes per day.

"The study group that was genetically predisposed to smoking was also genetically predisposed to a number of health problems, including obesity, diabetes, ADHD and various mental illnesses, whereas a genetic risk for alcohol was associated with lower disease risk. This does not imply that consuming more alcohol improves health, but indicates a mechanistic complexity that needs to be investigated further," Hveem says

We reported evidence for the involvement of many natural signalling agents in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission which to some extent may provide a biological explanation for why we seek artificial stimuli.

New insights

The data that was collected came from a number of studies and included different age categories, societies with different attitudes to the use of drugs and different patterns of alcohol and nicotine use. However, results showed that the correlation between genetic risk and the development of different disease categories varied little between the population groups.

It is important to note that a gene variant that predisposes a person to a certain trait does not have to be "expressed" or biologically active, which could depend on several factors. The interplay between different genes may play a role, and social conditions also influence the use of alcohol and tobacco, making it difficult to draw any firm conclusions.

This research gives new insight into the complexity of genetic and environmental factors that compel some of us to drink and smoke more than others. It is also interesting to note that some of these genes linked to increased use of alcohol, reduce the risk for some diseases.

ROCHESTER, Minn. -- Leprosy has a history that has spanned centuries and societies across the globe. Yet, it continues to be a problem -- even in the modern era. Sufferers from the chronic and infectious skin disease still face the social stigma and lack of medical care that people have endured since the origins of the disease itself. Although leprosy can be treated, the World Health Organization reported 216,108 cases in 2016, with some of these patients seeking treatment at Mayo Clinic's Rochester campus.

Looking at risk factors and demographic information of sufferers, researchers discuss local case studies of leprosy in the upcoming issue of Mayo Clinic Proceedings.

Using an electronic health record database, researchers identified nine patients with leprosy who were evaluated and treated at Mayo Clinic from 1994 to 2017. Demographic information was obtained on these patients, including age, gender, country of origin, travel history and skin biopsy results. Seven patients were men, and two were women. Their ages ranged from 15 to 63. Six patients had emigrated from foreign countries -- Guam, Indonesia, Mexico and Micronesia -- and three patients were born in the U.S. All of the patients had skin lesions of leprosy that involved their trunk, upper and lower extremities, and/or head and neck. Many of the patients also had neurological symptoms, including a reduced sense of touch.

Common factors found in patients in the review include Micronesian lineage and extensive travel while being immunosuppressed. Spencer Bezalel, M.D., one of the authors, notes that the average person in the U.S. is not at risk for contracting leprosy. "Immunosuppressed people traveling to countries where the disease is prevalent in high rates are at highest risk, as are people planning on being in close contact with others infected for long periods of time," says Dr. Bezalel.

Leprosy is caused mainly by the bacterium Mycobacterium leprae. Occasionally, it is caused by a newer species called M. lepromatosis. The disease mainly affects the skin and peripheral nerves. While the exact mechanism of transmission is not known, it is thought that a person needs to be in contact with an infected individual for an extended period of time. In some cases, armadillos, who are hosts of the bacteria, have been known to transmit the disease. In most modern instances, people who develop leprosy are immunosuppressed, such as transplant patients or those taking immunosuppressive medications for other reasons. Otherwise, these people live in or travel to places where the rates of leprosy are high.

While leprosy is rare within the U.S., this research illustrates that the disease cannot be entirely ruled out in certain circumstances. Treatment of leprosy with antibiotics and vigilance on behalf of immunosuppressed people or those who travel considerably is adequate to prevent the devastation caused by leprosy in days past. "Leprosy is not highly contagious or easily spread, and most people have immunity against the disease," says Dr. Bezalel.

Food can conjure up all kinds of warm and fuzzy feelings--childhood nostalgia, memories of road trips, or just the simple comfort of a nourishing cup of soup.

For restaurants, though, conveying a sense of love could be as simple as picking a different menu font.

A recent study found that when restaurant diners read menus with healthy food options printed in a typeface that appears handwritten, they were more likely to believe that the food was better for their bodies, made of better ingredients, and prepared with more care than similar items printed in machine-style fonts.

"The handwritten typeface conveys love, and that sense of human touch feels even more salient," said Stephanie Liu, co-author of the study and assistant professor of hospitality management at The Ohio State University. "It feels to the customer like there is more heart, more effort, and more love in it, even though it doesn't cost any more money."

The team's findings were published Feb. 10 in the Journal of Business Research.

The researchers conducted online surveys and found that the positive-response phenomenon occurred only when customers perceived the restaurant or menu items as healthy or locally grown--when the restaurant's brand was health-focused.

"This wouldn't apply to a fast-food brand that sells low-quality hamburgers," Liu said.

But a font that appeared handwritten, even if it had been produced by a computer and not actually written by hand, triggered the perception that extra love and care are imbued in the restaurant's offerings.

Liu has a theory about why this might be: The world is growing ever-more automated and ever-more mechanized. Technology can put distance between humans and occasionally remove the warmth that comes with human touch.

Handwriting can convey that warmth, because it requires more effort than typewritten font. A handwritten note, for example, is more personal than one typed on a computer. A typeface that appears handwritten, with imperfect curves and slants and organic strokes, conveys a deeper sense of emotional connection than machine-written typeface, which is typically squared, straight and uniform.

"As a marketing strategy, customers are just subconsciously processing information, and they feel that human touch in the letters on the menu," Liu said. "And they feel that the restaurant put more effort into the design of this menu and they are getting this product to you with more care."

Handwritten typeface might also help solo diners feel slightly less lonely, the researchers found, creating a sense of warmth and connection with the restaurant that could inspire those customers to return.

The researchers found that when customers believed the menu contained "love," those customers were more likely to interact with the restaurant's brand on social media, Liu said.

Lesbian and bisexual women are at increased risk of being overweight or obese compared to heterosexual women, according to new research from the University of East Anglia and UCL.

Gay men however are less likely to be overweight than their straight counterparts, and more at risk of being underweight.

The study, published today in the Journal of Public Health, is the first to investigate the relationship between sexual orientation and body mass index (BMI) using population data in the UK.

The findings support the argument that sexual identity should be considered as a social determinant of health.

The research team pooled data from 12 UK national health surveys involving 93,429 participants and studied the relationship between sexual orientation and BMI.

Lead researcher Dr Joanna Semlyen, from UEA's Norwich Medical School, said: "We found that women who identify as lesbian or bisexual are at an increased risk of being overweight or obese, compared to heterosexual women. This is worrying because being overweight and obese are known risk factors for a number of conditions including coronary heart disease, stroke, cancer and early death.

"Conversely, gay and bisexual men are more likely than heterosexual men to be underweight, and there is growing evidence that being underweight is linked to a range of health problems too, including excess deaths.

"We also found that gay men are significantly less likely than straight men to be overweight or obese.

"This study demonstrates that there is a relationship between sexual identity and BMI and that this link appears to be different for men and women.

"There are a number of possible explanations for these findings. We know that sexual minority groups are more likely to be exposed to psychosocial stressors, which impacts on their mental health and their health behaviours such as smoking and alcohol use and which may influence their health behaviours such as diet or physical activity.

"These stressors include homophobia and heterosexism, negative experiences that are experienced by the lesbian, bisexual and gay population as a result of their sexual orientation identity and are known to be linked to health.

"Until 2008, sexual orientation wasn't recorded in health surveys. This means that until recently it has not been possible to determine health inequalities affecting lesbian, gay and bisexual people.

"Continued collection of data on sexual orientation identity within national health surveys allows us to measure the health of sexual minorities.

"We hope that policy makers and clinicians will be able to use this fresh evidence to provide better healthcare and tailored advice and interventions for lesbian, gay and bisexual people. We need longitudinal research to understand the factors underlying the relationship between sexual orientation and BMI, and research to understand more about being underweight, especially in this population."

Researchers in Japan think they have found an answer to the fundamental biological question of how individual cells know which way to position themselves within a complex, multicellular body. Depending on a cell's purpose in the larger structure, contact or diffuse chemical signals direct it to its final destination.

The journey from egg and sperm to a fully grown body requires more than just multiplication. Plants, animals, and people are all made of trillions of cells, carefully organized into larger structures like tissues and organs. Somehow, each cell knows where it belongs - the left side of the heart, the inner lining of the colon, and so on - and generally stays put.

"It's close to impossible to dissect what's happening while cells position themselves in multicellular organisms because there are so many players: different cell types, different molecules inside cells, different chemical signals outside the cells, cell growth, programmed cell death," said Professor Satoshi Sawai from the University of Tokyo, an expert in biological physics, a field that uses the principles of physics to understand living systems.

The slime mold system

Slime molds provide a simpler system to understand cell positioning. Slime molds are amoebas, but are similar in size and shape to human white blood cells and share the fundamental aspects of cell dynamics, such as migration and engulfment of disease-causing pathogens.

Individual cells of the slime mold Dictyostelium discoideum can exist independently, living freely in the soil and eating bacteria and fungi. When food is scarce, independent slime mold cells clump together and function as a multicellular organism.

When slime mold cells clump together, sometimes 100 cells, other times 10,000 cells, they differentiate into two distinct types.

The first type, pre-stalk cells, eventually forms a column that supports a sphere composed of the second type, pre-spore cells. Researchers call this two-part structure a fruiting body. The pre-stalk cells will die as the pre-spore cells eventually float off in the wind to a better environment where they can grow and divide again as independent amoebas.

Inside the clump, before the fruiting body takes shape, cells attach to form long trains and swirl around, immersed in a chemical signal that they secrete. First identified in the 1970s, this diffusive chemical, called cAMP, attracts cells.

Traditionally, the degree of attraction to cAMP signals was thought to separate the cells into pre-stalk and pre-spore cells. More recent genetic experiments revealed, however, that molecules related to adhesion, or cell-to-cell touch, may also be important.

"What's great about slime mold is that you can take individual cells out of the larger structure and they still do their thing by behaving naturally in a relatively simple setup that mimics the multicellular environment," said Sawai.

Two types of signals

In their new experiments, the researchers took cells out of a multicellular clump and tracked how the individual cells migrate in response to artificial touch and cAMP signals.

When cell trains formed, the leader cell moved in the direction of cAMP. The follower cells were not pulled along, but rather actively pushed leader cells forward.

"Cell-cell contact activates processes for cell movement. The follower cells are the engine and the leader cells are the steering wheel, always pointing in the direction of the chemical signal," said Sawai.

Researchers also placed individual pre-stalk or pre-spore cells with beads coated with an adhesion molecule that appears to function in the tail end of cells. All cells attached to follow the bead as in a cell train. Researchers then added cAMP to the experiment. Pre-stalk cells released the bead and moved towards the cAMP source. Pre-spore cells, however, ignored cAMP and held fast to the bead.

Sawai's research team demonstrated that head-to-tail touch between cells directs their migration, but cAMP somehow overrides this contact only in pre-stalk cells.

"Many people think you have to go to Mars to look for the fundamental rules of what makes life. But we can look at all the still-unexplored branches of the tree of life here on Earth. Slime mold gives us hints at what to look for to understand the mechanistic logics underlying more complex species," said Sawai.

This discovery of the importance of cell-cell contact to activate cell movement and organization will open new possibilities to study cell-pattern formation in events such as embryo development or spread of breast cancer.

The results are published in the Proceedings of the National Academy of Sciences of the United States of America.

One of the largest field experiments ever conducted is providing the best evidence yet in support of a key Darwinian theory--that interactions between species are stronger toward the tropics and at lower elevations.

An international research team used a simple experiment that mimics how plants and animals interact with each other--leaving seeds out for 24 hours to see how many are consumed by animals. Seven thousand seed beds were deployed across a huge geographic area, with 70 sites cutting across 18 mountains from Alaska to the Equator.

"Theory predicts that interactions among species--like predation and competition--will be strongest in the warm, productive, biodiverse ecosystems of the tropics and at low elevations," says lead author Anna Hargreaves, who launched the project while at UBC's Biodiversity Research Centre. She is now a professor at McGill University.

"For example, the spectacular diversity of tropical trees is thought to result partly from stronger interactions between plants and the animals that prey on their seeds, which shapes how and where plants grow and adapt."

But until recently, evidence for this key ecological theory was inconclusive and came from small-scale studies that used different methods.

The new study found seed consumption, or predation, increased by 2.6 per cent for every 10 degrees of latitude toward the Equator and by 0.4 per cent for every 100-metre decline in elevation. In total, seed predation increased 17 per cent between Alaska and Equator and by 17 per cent from 4,000 metres above sea level to sea level.

The researchers used consistent methods from the Arctic to Equator and replicated the 24-hour experiment several times during each latitude's natural seed-producing period.

"These interactions form the basis of how ecosystems function and the direct benefits of those ecosystems to human society," says Santiago David, a PhD student at UBC who ran one of the study sites in Colombia. "Understanding global patterns in key interactions between species, such as seed predation, is essential when we think about managing or restoring the ecosystems, especially in the face of climate change."

Predation driven by insects, other invertebrates

By protecting some seeds from mammals, the researchers showed that the study's large-scale patterns are being driven by the smallest seed predators: insects and other invertebrates.

The only other standardized experiment of comparable scale used clay model caterpillars and found that attack rates on the model caterpillars increased toward low latitudes--an interaction also driven largely by invertebrates.

"Taken together, these experiments suggest that invertebrates play an outsized role in the community dynamics and evolution of tropical and lowland ecosystems," says Hargreaves. "And yet we know relatively little about invertebrates, for example, how climate change is affecting their populations."

The researchers are now combining fake caterpillars with the seeds to determine if the patterns they found with one form of predation hold true with another.

The study, "Seed predation increases from the Arctic to the Equator and from high to low elevations," involved researchers from 13 institutions across the Americas, was published today in Science Advances.

https://doi.org/10.1126/sciadv.aau4403

Why do zebras have stripes? A study published in PLOS ONE today [Wednesday 20 February] takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

The evolution of the zebra's two-tone coat has intrigued scientists for over 150 years. Many theories have been proposed, including avoiding predators, better heat regulation and a social function, yet there is still no agreement between scientists.

Now, researchers from the University of Bristol and UC Davis, California, USA, have added evidence to the theory that the primary purpose of zebras' stripes is for avoiding blood-sucking parasites.

Professor Tim Caro, Dr Martin How and colleagues have been investigating the behaviours of tabanid horse flies around captive zebras and domestic horses at a livery in North Somerset, using video analysis techniques.

Their new study has shown that stripes don't deter horse flies from a distance, with both zebras and domestic horses experiencing the same rate of circling from the flies. However, video analyses revealed differences in approach speed, with horse flies failing to slow down on approach to zebras, which is essential for a successful landing.

Professor Tim Caro, Honorary Research Fellow from the University of Bristol's School of Biological Sciences, said: "Horse flies just seem to fly over zebra stripes or bump into them, but this didn't happen with horses. Consequently, far fewer successful landings were experienced by zebras compared to horses."

Dr Martin How, Royal Society University Research Fellow in the School of Biological Sciences, added: "This reduced ability to land on the zebra's coat may be due to stripes disrupting the visual system of the horse flies during their final moments of approach.

"Stripes may dazzle flies in some way once they are close enough to see them with their low-resolution eyes."

Their second experiment was to observe horse fly behaviour around the same horses wearing different coloured cloth coats: black, white or zebra striped livery. This excluded any differences in behaviour or smell between horses and zebras. Just as before, when horses wore coats with striped patterns, they experienced fewer horse fly landings compared to when they wore single-colour coats.

Horse flies are a widespread problem for domestic animals so mitigating techniques, such as the development of anti-fly wear designed to resemble zebra stripes, may, from this research, be an interesting outcome for animal health and wellbeing.

The research also directly observed zebra and horse behaviour in response to biting flies. Zebras exhibited preventative behaviour, such as running away and tail swishing at a far higher rate than horses. Consequently, any horse flies that did successfully land on zebras spent less time there compared to those landing on horses, with few staying long enough to probe for a blood meal.

In Africa where zebras are native, horse flies carry dangerous debilitating diseases such as trypanosomiasis and African horse sickness which cause wasting and often death. Therefore, it is unsurprising that zebras utilise both behavioural defences and morphological striping to avoid horse flies.

This research provides new evidence for the theory that zebras evolved dichromatic striped coats to evade biting flies and has considerable implications for the horse industry.

Salt apparently affects allergic immune reactions. A team working with Prof. Christina Zielinski at the Technical University of Munich (TUM) has demonstrated in cell cultures that salt leads to the formation of Th2 cells. These immune cells are active in allergic conditions such as atopic dermatitis. The team also detected elevated salt concentrations in the skin of patients.

In industrial countries, nearly one in three people are affected by allergies at some point in their lives. One in ten children suffer from atopic dermatitis. T-cells play an important role in immune conditions of this kind. They are a vital aspect of the body's resistance to infections, but, if uncontrolled, can also develop pathological responses and start attacking parts of our bodies or innocuous substances such as allergens.

When such functions occur, Th2 cells, a subgroup of T cells, can cause inflammatory skin conditions such as atopic dermatitis. This involves increased production of the proteins interleukin 4 (IL-4) and interleukin 13 (IL-13). It is still unknown what triggers the signalling malfunction.

More Th2 cells under the influence of sodium ions

Table salt, known scientifically as sodium chloride, is essential to the health of humans and animals. In the body it occurs in the form of sodium and chlorine ions. In a recent study, Christina Zielinski, a DZIF-professor at TUM's Institute of Virology, and her team were able to demonstrate that sodium chloride can induce a state in human T cells that causes them to produce increased amounts of the proteins IL-4 and IL-13.

Types of T-cells, which should not cause allergies, can, in the presence of salt, turn into Th2 cells. The changes are reversed when the T cell is again exposed to lower salt levels. "Consequently, ionic signals do play a role in the generation and control of Th2 cells," says Christina Zielinski.

Highly elevated salt levels in the skin of patients suffering from atopic dermatitis

As a medical specialist in the field of dermatology, Zielinski is naturally interested in atopic dermatitis. Her team investigated whether the affected skin regions of atopic dermatitis patients exhibit elevated sodium levels." Measuring sodium concentrations in the tissue is complicated," explains the first author of the study, Julia Matthias. "Dissolved salt in blood can be measured using standard clinical methods. But for the skin, we needed the help of colleagues in nuclear chemistry and physics." They tested the skin samples at the Research Neutron Source Heinz Maier-Leibnitz (FRM II) at TUM and at the Institute for Nuclear Chemistry at the University of Mainz by means of neutron activation analysis. The sodium levels in the affected skin areas of patients suffering from atopic dermatitis proved to be up to 30 times higher than in healthy skin.

Ideal conditions for bacteria thriving under salty conditions

"The higher sodium levels in the affected skin neatly match another characteristic of atopic dermatitis," says Christina Zielinski. "It has been known for some time that patients with this condition have elevated levels of the bacterium Staphylococcus aureus on their skin. These are bacteria, which thrive under salty conditions - in contrast to other commensal bacteria, which are in fact harmed by salt." Zielinski believes that this insight along with others and the current research results point to a link between salt and the occurrence of atopic dermatitis.

"However, we have not yet been able to show how these large quantities of salt find their way to the skin," she concedes. "For that reason, we are also unsure of how a low-salt or high-salt diet might be related to the appearance and progression of atopic dermatitis or other allergic conditions." Professor Zielinski and her team hope to answer these and other questions in future interdisciplinary studies.