A new analysis suggests that schools and colleges, large companies and other organizations that want to keep themselves safe with frequent mass testing should think beyond their own personnel.By dedicating a substantial portion of their tests to people in the surrounding community, they can reduce the number of Covid-19 cases among their members by as much as 25 percent, researchers report in a new paper, which has not yet been published in a scientific journal.“It’s natural in an outbreak for people to become self-serving, self-focused,” said Dr. Pardis Sabeti, a computational biologist at Harvard University and the Broad Institute who led the analysis. But she added, “If you’ve been in enough outbreaks, you just understand that testing in a box doesn’t makes sense. These things are communicable, and they’re coming in from the community.”The study has “really profound implications, especially if others can replicate it,” said David O’Connor, a virologist at the University of Wisconsin, Madison, who was not involved in the analysis but reviewed a draft of the paper.Early in the pandemic, when testing resources were in short supply, many colleges proposed intensive, expensive testing regimens focused entirely on their own campuses. When they sought Dr. Sabeti’s advice, she said, she told them they ought to test friends, relatives and neighbors of their students and employees as well.It was not an easy idea to sell without data on its effectiveness, so Dr. Sabeti and her colleagues developed an epidemiological model to simulate how a virus might spread through a midsize institution, Colorado Mesa University, and what would happen under different testing policies. They found that allocating some tests to community contacts would significantly reduce the expected number of Covid cases on campus.C.M.U. now offers free tests to all of its students’ self-reported contacts, and runs a testing site that is open to local residents, according to Amy Bronson, a co-chair of the university’s Covid-19 task force and an author of the paper.And in November, the University of California, Davis, began offering free coronavirus tests to anyone who lives or works in that city.“A virus does not respect geographic boundaries,” said Brad Pollock, an epidemiologist at U.C. Davis who directs the project. “It is ludicrous to think that you can get control of an acute infectious respiratory disease like Covid-19, in a city like Davis that hosts a very large university, without coordinated public health measures that connect both the university and the community.”

A 10-week muscle-building and dietary program involving 50 middle-aged adults found no evidence that eating a high-protein diet increased strength or muscle mass more than consuming a moderate amount of protein while training. The intervention involved a standard strength-training protocol with sessions three times per week. None of the participants had previous weightlifting experience.
Published in the American Journal of Physiology: Endocrinology and Metabolism, the study is one of the most comprehensive investigations of the health effects of diet and resistance training in middle-aged adults, the researchers say. Participants were 40-64 years of age.
The team assessed participants’ strength, lean-body mass, blood pressure, glucose tolerance and several other health measures before and after the program. They randomized participants into moderate- and high-protein diet groups. To standardize protein intake, the researchers fed each person a freshly cooked, minced beef steak and carbohydrate beverage after every training session. They also sent participants home with an isolated-protein drink to be consumed every evening throughout the 10 weeks of the study.
“The moderate-protein group consumed about 1.2 grams of protein per kilogram of body weight per day, and the high-protein group consumed roughly 1.6 grams per kilogram per day,” said Colleen McKenna, a graduate student in the division of nutritional sciences and registered dietician at the University of Illinois Urbana-Champaign who led the study with U. of I. kinesiology and community health professor Nicholas Burd. The team kept calories equivalent in the meals provided to the two groups with additions of beef tallow and dextrose.
The study subjects kept food diaries and McKenna counseled them every other week about their eating habits and protein intake.
In an effort led by U. of I. food science and human nutrition professor Hannah Holscher, the team also analyzed gut microbes in fecal samples collected at the beginning of the intervention, after the first week — during which participants adjusted to the new diet but did not engage in physical training — and at the end of the 10 weeks. Previous studies have found that diet alone or endurance exercise alone can alter the composition of microbes in the digestive tract.

One-third of the Earth’s surface is covered by more than 11,000 grass species — including crops like wheat, corn, rice and sugar cane that account for the bulk of the world’s agricultural food production and important biofuels. But grass is so common that few people realize how diverse and important it really is.
Research published today in the journal Nature provides insights that scientists could use not only to improve crop design but also to more accurately model the effects of climate change. It also offers new clues that could help scientists use leaf fossils to better interpret the climate of the ancient past.
The study’s senior author is Lawren Sack, a UCLA professor of ecology and evolutionary biology and one of the world’s most influential scientific researchers.
The research determined that grass with narrow leaves and high numbers of veins should be better able to withstand the drier conditions expected in the future. That finding should enable scientists to better predict grass species’ ability to tolerate cold and drought — important for conserving species amidst climate change. It also suggests that scientists who are breeding agricultural grasses to better survive cold climates and drought should turn their focus toward varieties with smaller leaves and more large veins.
From other types of plants, scientists have learned that leaf size is an important factor in how plants adapt to their environments. But until now, it was not known how thousands of species of grass could exist in so many diverse environments, and whether leaf size might play a role.
“Grass leaf blades can vary in size from a few square millimeters for grasses of the high Andes to more than a square meter for tropical bamboos,” Sack said.

Researchers have developed a new microscopy technique that can acquire 3D super-resolution images of subcellular structures from about 100 microns deep inside biological tissue, including the brain. By giving scientists a deeper view into the brain, the method could help reveal subtle changes that occur in neurons over time, during learning, or as result of disease.
The new approach is an extension of stimulated emission depletion (STED) microscopy, a breakthrough technique that achieves nanoscale resolution by overcoming the traditional diffraction limit of optical microscopes. Stefan Hell won the 2014 Nobel Prize in Chemistry for developing this super-resolution imaging technique.
In Optica, The Optical Society’s (OSA) journal for high impact research, the researchers describe how they used their new STED microscope to image, in super-resolution, the 3D structure of dendritic spines deep inside the brain of a living mouse. Dendric spines are tiny protrusions on the dendritic branches of neurons, which receive synaptic inputs from neighboring neurons. They play a crucial role in neuronal activity.
“Our microscope is the first instrument in the world to achieve 3D STED super-resolution deep inside a living animal,” said leader of the research team Joerg Bewersdorf from Yale School of Medicine. “Such advances in deep-tissue imaging technology will allow researchers to directly visualize subcellular structures and dynamics in their native tissue environment,” said Bewersdorf. “The ability to study cellular behavior in this way is critical to gaining a comprehensive understanding of biological phenomena for biomedical research as well as for pharmaceutical development.”
Going deeper
Conventional STED microscopy is most often used to image cultured cell specimens. Using the technique to image thick tissue or living animals is a lot more challenging, especially when the super-resolution benefits of STED are extended to the third dimension for 3D-STED. This limitation occurs because thick and optically dense tissue prevents light from penetrating deeply and from focusing properly, thus impairing the super-resolution capabilities of the STED microscope.
To overcome this challenge, the researchers combined STED microscopy with two-photon excitation (2PE) and adaptive optics. “2PE enables imaging deeper in tissue by using near-infrared wavelengths rather than visible light,” said Mary Grace M. Velasco, first author of the paper. “Infrared light is less susceptible to scattering and, therefore, is better able to penetrate deep into the tissue.”
The researchers also added adaptive optics to their system. “The use of adaptive optics corrects distortions to the shape of light, i.e., the optical aberrations, that arise when imaging in and through tissue,” said Velasco. “During imaging, the adaptive element modifies the light wavefront in the exact opposite way that the tissue in the specimen does. The aberrations from the adaptive element, therefore, cancel out the aberrations from the tissue, creating ideal imaging conditions that allow the STED super-resolution capabilities to be recovered in all three dimensions.”
Seeing changes in the brain
The researchers tested their 3D-2PE-STED technique by first imaging well-characterized structures in cultured cells on a cover slip. Compared to using 2PE alone, 3D-2PE-STED resolved volumes more than 10 times smaller. They also showed that their microscope could resolve the distribution of DNA in the nucleus of mouse skin cells much better than a conventional two-photon microscope.
After these tests, the researchers used their 3D-2PE-STED microscope to image the brain of a living mouse. They zoomed-in on part of a dendrite and resolved the 3D structure of individual spines. They then imaged the same area two days later and showed that the spine structure had indeed changed during this time. The researchers did not observe any changes in the structure of the neurons in their images or in the mice’s behavior that would indicate damage from the imaging. However, they do plan to study this further.
“Dendritic spines are so small that without super-resolution it is difficult to visualize their exact 3D shape, let alone any changes to this shape over time,” said Velasco. “3D-2PE-STED now provides the means to observe these changes and to do so not only in the superficial layers of the brain, but also deeper inside, where more of the interesting connections happen.”
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Increased allergic reactions may be tied to the corticotropin-releasing stress hormone (CRH), suggests a study published this month in the International Journal of Molecular Sciences. These findings may help clarify the mechanism by which CRH induces proliferation of mast cells (MC) — agents involved in the development of allergies in the human nasal cavity.
“In my daily practice, I meet many patients with allergies who say their symptoms worsened due to psychological stress,” states lead researcher Mika Yamanaka-Takaichi, a graduate student of the Department of Dermatology, Osaka City University, “This is what led me to do this research.”
Together with Professor Daisuke Tsuruta of the same department, they hypothesized that due to its role in inducing MC degranulation in human skin, “CRH may also be involved in stress-aggravated nasal allergies,” says Professor Tsuruta.
When the team added CRH to a nasal polyp organ culture, they saw a significant increase in the number of mast cells, a stimulation both of MC degranulation and proliferation, and an increase of stem cell factor (SCF) expression, a growth factor of mast cells, in human nasal mucosa- the skin of the nasal cavity. In exploring possible therapeutic angles, “we saw the effect of CRH on mast cells blocked by CRHR1 gene knockdown, CRHR1 inhibitors, or an addition of SCF neutralizing antibodies,” states Dr. Yamanaka-Takaichi.
In vivo, the team found an increase in the number of mast cells and degranulation in the nasal mucosa of mouse models of restraint stress, which was inhibited by the administration of CRHR1 inhibitor, antalarmin.
“In addition to understanding the effects stress has on our allergies, we have also found promising therapeutic potential in candidates like antalarmin,” adds Dr. Yamanaka-Takaichi, “And this is wonderful news for my patients.”
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Food scientists from Nanyang Technological University, Singapore (NTU Singapore) have made an antibacterial gel bandage using the discarded husks of the popular tropical fruit, durian.
Known as the “King of Fruits” in Southeast Asia, the durian has a thick husk with spiky thorns which is discarded, while the sweet flesh surrounding the seeds on the inside is considered a delicacy.
By extracting high-quality cellulose from the durian husks and combining it with glycerol — a waste by-product from the biodiesel and soap industry — NTU scientists created a soft gel, similar to silicon sheets, which can be cut into bandages of various shapes and sizes.
They then added the organic molecules produced from baker’s yeast known as natural yeast phenolics, making the bandage deadly to bacteria.
Developed by Professor William Chen, the Director of NTU’s Food Science and Technology Programme, the innovation was published recently in ACS Sustainable Chemistry & Engineering, a peer-reviewed journal of the American Chemistry Society.
Conventional hydrogel patches are commonly available at pharmacies, usually used to cover wounds from surgery to minimise the formation of excessive scar tissue, resulting in a softer and flatter scar. The patch keeps the skin hydrated instead of drying up when conventional band-aid or gauze bandages are used.

An international team of scientists has found evidence that SARS-CoV-2, the virus that causes COVID-19, infects cells in the mouth. While it’s well known that the upper airways and lungs are primary sites of SARS-CoV-2 infection, there are clues the virus can infect cells in other parts of the body, such as the digestive system, blood vessels, kidneys and, as this new study shows, the mouth. The potential of the virus to infect multiple areas of the body might help explain the wide-ranging symptoms experienced by COVID-19 patients, including oral symptoms such as taste loss, dry mouth and blistering. Moreover, the findings point to the possibility that the mouth plays a role in transmitting SARS-CoV-2 to the lungs or digestive system via saliva laden with virus from infected oral cells. A better understanding of the mouth’s involvement could inform strategies to reduce viral transmission within and outside the body. The team was led by researchers at the National Institutes of Health and the University of North Carolina at Chapel Hill.
“Due to NIH’s all-hands-on-deck response to the pandemic, researchers at the National Institute of Dental and Craniofacial Research were able to quickly pivot and apply their expertise in oral biology and medicine to answering key questions about COVID-19,” said NIDCR Director Rena D’Souza, D.D.S., M.S., Ph.D. “The power of this approach is exemplified by the efforts of this scientific team, who identified a likely role for the mouth in SARS-CoV-2 infection and transmission, a finding that adds to knowledge critical for combatting this disease.”
The study, published online March, 25, 2021 in Nature Medicine, was led by Blake M. Warner, D.D.S., Ph.D., M.P.H., assistant clinical investigator and chief of NIDCR’s Salivary Disorders Unit, and Kevin M. Byrd, D.D.S., Ph.D., at the time an assistant professor in the Adams School of Dentistry at the University of North Carolina at Chapel Hill. Byrd is now an Anthony R. Volpe Research Scholar at the American Dental Association Science and Research Institute. Ni Huang, Ph.D., of the Wellcome Sanger Institute in Cambridge, U.K., and Paola Perez, Ph.D., of NIDCR, were co-first authors.
Researchers already know that the saliva of people with COVID-19 can contain high levels of SARS-CoV-2, and studies suggest that saliva testing is nearly as reliable as deep nasal swabbing for diagnosing COVID-19. What scientists don’t entirely know, however, is where SARS-CoV-2 in the saliva comes from. In people with COVID-19 who have respiratory symptoms, virus in saliva possibly comes in part from nasal drainage or sputum coughed up from the lungs. But according to Warner, that may not explain how the virus gets into the saliva of people who lack those respiratory symptoms.
“Based on data from our laboratories, we suspected at least some of the virus in saliva could be coming from infected tissues in the mouth itself,” Warner said.
To explore this possibility, the researchers surveyed oral tissues from healthy people to identify mouth regions susceptible to SARS-CoV-2 infection. Vulnerable cells contain RNA instructions for making “entry proteins” that the virus needs to get into cells. RNA for two key entry proteins — known as the ACE2 receptor and the TMPRSS2 enzyme — was found in certain cells of the salivary glands and tissues lining the oral cavity. In a small portion of salivary gland and gingival (gum) cells, RNA for both ACE2 and TMPRSS2 was expressed in the same cells. This indicated increased vulnerability because the virus is thought to need both entry proteins to gain access to cells.

Dining out is a popular activity worldwide, but there has been little research into its association with health outcomes. Investigators looked at the association between eating out and risk of death and concluded that eating out very frequently is significantly associated with an increased risk of all-cause death, which warrants further investigation. Their results appear in the Journal of the Academy of Nutrition and Dietetics, published by Elsevier.
Eating out is a popular activity. The US Department of Agriculture recently estimated that Americans’ daily energy intake from food away from home increased from 17 percent in 1977-1978 to 34 percent in 2011-2012. At the same time, the number of restaurants has grown steadily, and restaurant-industry sales are forecasted to increase significantly.
Although some restaurants provide high-quality foods, the dietary quality for meals away from home, especially from fast-food chains, is usually lower compared with meals cooked at home. Evidence has shown that meals away from home tend to be higher in energy density, fat, and sodium, but lower in fruits, vegetables, whole grains, and protective nutrients such as dietary fiber and antioxidants.
“Emerging, although still limited, evidence suggests that eating out frequently is associated with increased risk of chronic diseases, such as obesity and diabetes and biomarkers of other chronic diseases,” explained lead investigator Wei Bao, MD, PhD, assistant professor, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA. “However, little is known about the association between eating meals away from home and risk of mortality.
Investigators analyzed data from responses to questionnaires administered during face-to-face household interviews from 35,084 adults aged 20 years or older who participated in the National Health and Nutritional Examination Survey 1999-2014. Respondents reported their dietary habits including frequency of eating meals prepared away from home. “We linked these records to death records through December 31, 2015, looking especially at all-cause mortality, cardiovascular mortality, and cancer mortality,” noted first author Yang Du, MD, PhD candidate, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA.
During 291,475 person-years of follow-up, 2,781 deaths occurred, including 511 deaths from cardiovascular disease and 638 deaths from cancer. After adjustment for age, sex, race/ethnicity, socioeconomic status, dietary and lifestyle factors, and body mass index, the hazard ratio of mortality among participants who ate meals prepared away from home very frequently (two meals or more per day) compared with those who seldom ate meals prepared away from home (fewer than one meal per week) was 1.49 (95% CI 1.05 to 2.13) for all-cause mortality, 1.18 (95% CI 0.55 to 2.55) for cardiovascular mortality, and 1.67 (95% CI 0.87 to 3.21) for cancer mortality.
“Our findings from this large nationally representative sample of US adults show that frequent consumption of meals prepared away from home is significantly associated with increased risk of all-cause mortality,” commented Dr. Du.
“This is one of the first studies to quantify the association between eating out and mortality,” concluded Dr. Bao. “Our findings, in line with previous studies, support that eating out frequently is associated with adverse health consequences and may inform future dietary guidelines to recommend reducing consumption of meals prepared away from home.”
“The take-home message is that frequent consumption of meals prepared away from home may not be a healthy habit. Instead, people should be encouraged to consider preparing more meals at home,” concluded the investigators.
Future studies are still needed to look more closely at the association of eating out with death from cardiovascular disease, cancer, dementia, and other chronic diseases.
“It is important to note that the study design for this research examines associations between frequency of eating meals prepared away from home and mortality. While encouraging clients to consider preparing healthy meals at home, registered dietitian nutritionists might also focus on how selections from restaurant menus can be healthy. Tailoring strategies to each client by reviewing menus from restaurants they frequent can help them make healthy food choices,” added co-investigator Linda G. Snetselaar, PhD, RDN, LD, FAND, professor and chair, Preventive Nutrition Education, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA, and Editor-in-Chief of the Journal of the Academy of Nutrition and Dietetics.

Anabolic androgenic steroids (AAS), a synthetic version of the male sex hormone testosterone, are sometimes used as a medical treatment for hormone imbalance. But the vast majority of AAS is used to enhance athletic performance or build muscle because when paired with strength training. AAS use increases muscle mass and strength, and its use is known to have many side effects, ranging from acne to heart problems to increased aggression. A new study now suggests that AAS can also have deleterious effects on the brain, causing it to age prematurely.
The report appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
“Anabolic steroid use has been associated with a range of medical and psychological side effects,” said lead author, Astrid Bjørnebekk, PhD, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway. “However, since anabolic steroids have only been in the public domain for about 35 years, we are still in the early phase of appreciating the full scope of effects after prolonged use. The least studied effects are those that relate to the brain.”
Steroid hormones readily enter the brain, and receptors for sex hormones are found throughout the brain. Because AAS are administered at much higher doses than those naturally found in the body, they could have a harmful impact on the brain, particularly over a long period of use. Previous studies have shown that AAS users performed worse on cognitive tests than non-users.
Dr. Bjørnebekk and colleagues performed magnetic resonance imaging (MRI) of the brains of 130 male weightlifters with a history of prolonged AAS use and of 99 weightlifters who had never used AAS. Using a set of data compiled from nearly 2,000 healthy males from age 18 to 92 years of age. The researchers used machine learning to determine the predicted brain age of each of their participants and then determined the brain age gap: the difference between each participant’s chronological age and their predicted brain age. Advanced brain age is associated with impaired cognitive performance and increased risk for neurodegenerative diseases.
Not surprisingly, AAS users had a bigger brain age gap compared to non-users. Those with dependence on AAS, or with a longer history of use, showed accelerated brain aging. The researchers accounted for use of other substances and for depression in the men, which did not explain the difference between the groups.
“This important study shows in a large sample that use is associated with deviant brain aging, with a potential impact on quality of life in older age. The findings could be directly useful for health care professionals, and may potentially have preventive implications, where brain effects are also included into the risk assessment for young men wondering whether to use anabolic steroids,” added Dr. Bjørnebekk.
Cameron Carter, MD, editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, said of the study: “The results of this brain imaging study should be of concern for athletes using anabolic steroids for performance enhancement and suggest that the adverse effects on behavior and cognition previously shown to be associated with long-term use are the result of effects on the brain in the form of accelerated brain aging.”
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SharecloseShare pageCopy linkAbout sharingimage copyrightGetty ImagesGerman Chancellor Angela Merkel has defended the EU’s decision to procure coronavirus vaccines jointly as the bloc struggles with delays in rollout.EU leaders are to hold virtual talks shortly to discuss ways of boosting vaccine supplies and improving distribution across the 27 nations.Pressure is mounting upon them to deliver after other countries, like the UK, achieved much faster vaccination.The European Commission is seeking added controls on vaccine exports.Such controls could affect supply to the UK, where Prime Minister Boris Johnson has warned against imposing “blockades”.The virtual summit comes as a third wave of coronavirus infections sweeps across much of mainland Europe.EU states have seen some of the deadliest outbreaks of the pandemic, with Italy recording more than 106,000 deaths, France 93,000, Germany 75,000 and Spain 73,000.Yet recent figures show just 12.9 doses of vaccine have been administered per 100 people in the EU compared with 44.7 in the UK and 37.2 in the US.Why is the EU having vaccine problems?Where is the Oxford-AstraZeneca vaccine made?EU tussle with UK over AstraZeneca jabs escalatesThe European Commission has blamed pharmaceutical companies – primarily AstraZeneca – for not delivering the promised doses to the EU. A site in Belgium produces the Oxford-AstraZeneca vaccine, and another in the Netherlands is expected to increase supplies of the jab in the EU.Brussels has said that of the more than 40 million doses exported from the EU over the past two months, a quarter were sent to the UK.The UK and the EU said on Wednesday they wanted to “create a win-win situation and expand vaccine supply for all”.What did Merkel say?Speaking to German MPs, the German chancellor said that if some members had had vaccine supplies and other had not, it would have shaken the EU’s internal market to its core.But some EU states, led by Austria, are calling for a revision in the distribution method after failing to obtain enough doses earlier this year.”We are in a situation where some member states will have vaccinated their population by the beginning or middle of May while for others, it will take six, eight or ten weeks longer,” Austrian Chancellor Sebastian Kurz said last week. “We believe that’s a problem.”Mrs Merkel warned that the impact of the pandemic could go beyond the current year.”We have to assume that the virus, with its mutations, may be occupying us for a long time to come so the question goes far beyond this year,” she said.The EU, she said, relied on what vaccines it could make locally because “British production sites are manufacturing for Britain and the United States is not exporting”.At the same time, more had to be done to ensure the rest of the world was supplied with vaccines, since otherwise new mutations would keep emerging, Mrs Merkel said.EU leaders had planned to meet face to face in Brussels but a third wave of the pandemic is sweeping across much of mainland Europe. So, a summit by video-conference was deemed safer. EU politicians are under increasing public pressure. Many voters blame their governments and Brussels for a vaccine rollout that lags far behind the UK. The European Commission blames pharmaceutical companies – primarily AstraZeneca – for not delivering jabs promised to the EU. But leaders are divided over proposals for new restrictions on vaccine exports out of the bloc to boost domestic supply. Some fear that would disrupt global supply chains needed to manufacture vaccines and damage already strained relations with the UK after Brexit. While there have been suggestions that the proposals being put before EU leaders on Thursday will be focused on the UK and US in particular, EU Health Commissioner Stella Kyriakides said that this was not the case. “We’re dealing with a pandemic and this is not seeking to punish any countries,” he said.What is the EU planning?The tougher export controls are most likely to affect vaccine-exporting countries that have higher vaccination rates than the EU, such as the UK and US. The key criteria for the proposed regulations are “reciprocity” and “proportionality”:The EU says there is no reciprocity if a country importing vaccines from the EU restricts exports itself – so it may review exports to this country Member states and the Commission will also consider the state of the pandemic in that country, its vaccination rate and vaccine supplies There will be no outright export bans, which are opposed by countries such as the Netherlands and Belgium. Vaccine manufacturers would be assessed to see if they were fulfilling their contract with the EU, although no specific algorithm is planned.In an interview with the BBC, the EU’s Internal Market Commissioner Thierry Breton insisted the bloc’s issues were with AstraZeneca and not the UK government. “I know that there’s some tension… but as long as we have transparency, I think [relations] will be able to be normalised,” he said.But he said that if AstraZeneca had provided the agreed 120 million doses to the EU, member states would have been at the same rate of vaccination as the UK: “We have been heavily penalised and we just want to understand why.”AstraZeneca denies that it is failing to honour its contract with the EU.