Daily Archives: 31 Jan 2021

Astronomy

Successful Test Paves Way for New Planetary Radar (Astronomy)

Leave a comment

The National Science Foundation’s Green Bank Observatory (GBO) and National Radio Astronomy Observatory (NRAO), and Raytheon Intelligence & Space conducted a test in November to prove that a new radio telescope system can capture high-resolution images in near-Earth space.

GBO’s Green Bank Telescope (GBT) — the world’s largest fully steerable radio telescope — was outfitted with a new transmitter developed by Raytheon Intelligence & Space, allowing it to transmit a radar signal into space. The NRAO’s continent-wide Very Long Baseline Array (VLBA) received the reflected signal and produced images of the Apollo 15 moon landing site.

The proof-of-concept test, culminating a two-year effort, paves the way for designing a more powerful transmitter for the telescope. More power will allow enhanced detection and imaging of small objects passing by the Earth, moons orbiting around other planets and other debris in the Solar System.

The technology was developed as part of a cooperative research and development agreement between NRAO, GBO, and Raytheon.

“This project opens a whole new range of capabilities for both NRAO and GBO,” said Tony Beasley, director of the National Radio Astronomy Observatory and vice president for Radio Astronomy at Associated Universities, Inc. (AUI). “We’ve participated before in important radar studies of the Solar System, but turning the GBT into a steerable planetary radar transmitter will greatly expand our ability to pursue intriguing new lines of research.”

Using the information collected with this latest test, the participants will finalize a plan to develop a 500-kilowatt, high-power radar system that can image objects in the Solar System with unprecedented detail and sensitivity. The increased performance also will allow astronomers to use radar signals as far away as the orbits of Uranus and Neptune, increasing our understanding of the Solar System.

“The planned system will be a leap forward in radar science, allowing access to never before seen features of the Solar System from right here on Earth,” said Karen O’Neil, the Green Bank Observatory site director.

“Raytheon’s radar techniques could ultimately improve our ability to explore the Solar System,” said Steven Wilkinson, Principal Engineering Fellow at Raytheon Intelligence & Space. “Working with the astronomy community allows us to apply decades of radar know-how to a project that provides high-resolution images of near-Earth objects.”

“We are excited to be partnering with Raytheon and applying their radar expertise to transform our observatories’ telescopes in new science areas,” said AUI President Adam Cohen.

The National Radio Astronomy Observatory and the Green Bank Observatory are facilities of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Featured image: New radar image of the Apollo 15 landing site, located with respect to prominent lunar features. Credit: Sophia Dagnello, NRAO/GBO/Raytheon/AUI/NSF/USGS

Provided by Green Bank Observatory

Medicine

CHOP Researchers Develop Potentially Safer, More Effective Gene Therapy Vector for Blood Disorders (Medicine)

Leave a comment

Researchers at Children’s Hospital of Philadelphia (CHOP) have developed a gene therapy vector for blood disorders like sickle cell disease and beta-thalassemia that is potentially safer and more effective than those currently used in gene therapy trials for those conditions. The vector, an engineered vehicle for delivering functional copies of the hemoglobin gene to correct a genetic abnormality, leads to the production of more hemoglobin with a lower dose, minimizing the risk of toxic side effects.

The findings were published today in Molecular Therapy.

“These results have many potential benefits for the successful treatment of patients affected by beta-globinopathies like sickle cell disease and beta-thalassemia, including a better dose response, a minimized chance of clonal expansion and tumorigenesis, a reduced cost of therapy, and a potentially reduced need for chemotherapy or radiation before beginning gene therapy,” said Laura Breda, PhD, research assistant professor at CHOP and first author of the paper. “All of us in the CuRED Frontier Program at CHOP are dedicated to finding new and improved curative therapies for blood disorders, and we look forward to taking steps to move this vector into clinical trials.”

Sickle cell disease and beta-thalassemia are genetic blood disorders caused by errors in the genes for hemoglobin, a protein consisting of globin and iron-containing subunits that is found in red blood cells and carries oxygen from the lungs to tissues throughout the body. The disorders, sometimes referred to as beta-globinopathies due to mutations in the beta-globin gene, lead to serious health complications, ranging from delayed growth and jaundice to pain crises, pulmonary hypertension, and stroke.

Because children with beta-globinopathies have two abnormal copies of the hemoglobin gene – one from each parent – researchers have explored gene therapy as a potential breakthrough treatment. Using an engineered carrier called a vector to introduce a functional copy of the beta-globin gene, this therapy has the potential to restore normal hemoglobin production in patients with beta-globinopathies. However, there are challenges to this approach, including limited dose response, dose-related toxicities, and the need in many cases for myeloablation, a procedure in which the bone marrow is suppressed via chemotherapy or radiation before gene therapy can begin.

In order to reduce unwanted side effects and increase effectiveness of gene therapy for these conditions, the CHOP researchers developed a new vector using an engineered lentivirus, the same retrovirus used to create gene therapy vectors in ongoing gene therapy trials for beta-globinopathies. The lentiviral vectors currently in use all contain the human beta-globin gene along with its promoter; three so-called hypersensitive sites that are important for gene transcription; and a truncated version of intron 2, which does not code for proteins.

The CHOP researchers hypothesized that including the full intron, rather than a truncated one, in addition to other genomic elements that promote uniform expression of the beta-globin gene would enhance beta-globin – and thus functional hemoglobin – expression. Based on this hypothesis, the research team generated five novel lentiviral vectors by combining different additional genomic elements. As a benchmark, they also generated three vectors similar to those that have already been used in clinical trials, which they used to compare to their novel vectors.

Using a variety of in vitro and in vivo screening approaches, the researchers found that one of their vectors, ALS20, expressed significantly higher transgenic hemoglobin levels than other vectors currently used to treat beta-globinopathies. Compared with the three benchmark vectors, ALS20 produced 157%, 84%, and 40% more adult hemoglobin, which would have a greater clinical impact on patients, especially those who require higher hemoglobin production to become transfusion independent. ALS20 was also more powerful, with a lower dose providing higher hemoglobin production, which could reduce the need for myeloablation and possibly allow for in vivo delivery methods.

From a safety standpoint, ALS20 viral particles did not contain unwanted genomic RNA byproducts, and mice treated with ALS20 exhibited normal physiology without any proliferative disorders or cancerous formations compared with controls.

Stefano Rivella, PhD, senior study author © CHOP

“Considering the body of evidence presented in this work, we believe that ALS20 is an outstanding candidate for the successful treatment of beta-globinopathies,” said senior author Stefano Rivella, PhD, Kwame Ohene-Frempong Chair on Sickle Cell Anemia and Professor of Pediatrics at CHOP. “Our vector may not only provide safer therapy with a reduced probability of genome toxicity and milder conditioning requirements, but it may also improve the efficacy and offer a competitive product for the gene therapy market.”

The research was supported by the Comprehensive Center for the Cure of Sickle Cell Disease and other Red Cell Disorders (CuRED) – Frontier Program at CHOP, the Commonwealth Universal Research Enhancement Program (CURE) – Department of Health of Pennsylvania, and the Associazione Veneta per la Lotta alla Talassemia (AVLT). The team also received support through private donations, including those from the 2018 CHOP Daisy Days campaign and The Runway.

Featured image: Group photo of research team © CHOP

Reference: Breda L, Ghiaccio V, Tanaka N, Jarocha D, Ikawa Y, Abdulmalik O, Dong A, Casu C, Raabe TD, Shan X, Danet-Desnoyers GA, Doto AM, Everett J, Bushman FD, Radaelli E, Assenmacher CA, Tarrant JC, Hoepp N, Guzikowski V, Smith-Whitley K, Kwiatkowski JL, and Rivella S. “Lentiviral vector ALS20 yields high hemoglobin levels with low genomic integrations for treatment of beta-globinopathies,” Molecular Therapy, online January 29, 2021. DOI: 10.1016/j.ymthe.2020.12.036

Provided by CHOP

Earth Science

Students In Scientific Writing Course Review ‘Lava Worlds’ in Academic Publication (Earth Science)

Leave a comment

In the early solar system, rocky planets, such as Earth, Mercury, Venus and Mars, and the Moon may have been ‘lava worlds,’ with oceans of magma blanketing the surface, according to planetary scientists. Similar magma-covered planets may orbit close to other stars and can be studied directly . Five earth sciences graduate students in the University of Hawai‘i at Mānoa’s School of Ocean and Earth Science and Technology (SOEST), along with their professor, published a scientific review of this stage in planetary evolution that may determine the later atmospheric composition and potential habitability of planets like Earth.

A critical skill for success in graduate studies and a career in the sciences is clear and concise writing. Courses in scientific writing such as those taught by Earth sciences professor Eric Gaidos are an opportunity for SOEST graduate students to develop their skills and get experience with publication.

This is the fourth time students in Gaidos’s writing class have successfully published their work in an academic journal.

“The introduction to scientific writing was invaluable and something that I was looking for,” said Kelly Truax, co-author and SOEST graduate student. “My first career was a mix of the arts and education which is a vastly different writing style. It became easier after working on this paper to understand the differences in tonality and structure. The project also offered a unique opportunity to write about subject matter outside of my research and receive feedback from all parties involved.”

This topic is particularly timely for the scientific community because NASA’s Transiting Exoplanet Survey Satellite is surveying the entire sky searching for close-in planets around bright stars—including “lava worlds” and the James Webb Space Telescope, scheduled to launch later this year will usher in a new era of precise measurements of those objects.

“I was interested in writing this paper on lava worlds because planetary volcanology has always been fascinating to me,” said Rebecca deGraffenried, co-author and SOEST graduate student.“It’s always fun to consider a process on Earth, and think about how that process would change under the range of conditions present on exoplanets. Particularly since I started studying Kīlauea, I’ve been interested in lava lakes. So this paper afforded the opportunity to both learn more about lava lakes in general and lava lakes on other worlds.”

Participating in a guided collaboration within the cohort is a significant feature of this approach to the course.

“Balancing the work with classes and research gave me confidence that I could balance everything,” said Truax. “Ultimately, the camaraderie around the work and the experiences along the way were invaluable and allowed for the rare chance to write predominantly with my peers versus those later into their careers.”

Said Gaidos, “This course was an opportunity for the students not only to pursue their individual scientific interests and improve their writing skills, but also to learn to work as a team toward a common goal, and then see a tangible result from their collective effort.”

The authors on the publication in the journal Geochemistry are Keng-Hsien Chao, Rebecca deGraffenried, Mackenzie Lach, William Nelson, Kelly Truax and Eric Gaidos.

Featured image: Halemaumau lava lake in Kilauea, taken in November 2013. Credit: Tom Shea.

Reference: Keng-Hsien Chao, Rebecca deGraffenried, Mackenzie Lach, William Nelson, Kelly Truax, Eric Gaidos, “Lava Worlds: From Early Earth to Exoplanets”, Geochemistry, 2021, 125735, ISSN 0009-2819,
https://doi.org/10.1016/j.chemer.2020.125735.
(http://www.sciencedirect.com/science/article/pii/S000928192030146X)

Provided by SOEST

Medicine

Pregnant Mothers’ Antibodies to SARS-CoV-2 Transfer Efficiently to their Fetuses (Medicine)

Leave a comment

Findings hint that vaccination of pregnant women might also protect their newborns.

Antibodies to the SARS-CoV-2 coronavirus in the blood of pregnant women cross the placenta efficiently and are were found at similar concentrations in the blood of their newborns, according to a large study from researchers at the Perelman School of Medicine at the University of Pennsylvania.

The findings, reported JAMA Pediatrics, suggest that mothers who have had COVID-19, or asymptomatic exposure to the coronavirus, can, through this antibody transfer, provide some protection against the virus to their newborns. The authors hypothesize that this may have implications for COVID-19 vaccines.

The researchers tested blood samples from 1,471 women and their newborns for the presence of antibodies to SARS-CoV-2, and observed that 83 of the women had significant levels of SARS-CoV-2-specific antibodies. The vast majority (87 percent) of the newborn babies of these women also had significant levels of SARS-CoV-2-specific antibodies in samples of umbilical cord blood drawn at birth. The study found no evidence that the antibodies were due to fetal infection, indicating that it is likely the antibodies crossed the placenta from the mother’s blood to the fetal circulation.

“This transfer appears to be pretty efficient,” said study co-senior author Karen Puopolo, MD, PhD, a neonatologist at Children’s Hospital of Philadelphia, an associate professor of Pediatrics at the University of Pennsylvania Perelman School of Medicine and Chief of the Section on Newborn Medicine at Pennsylvania Hospital. “In some of the cases, the newborn’s blood concentration of SARS-CoV-2 antibodies was even higher than the mother’s.”

“In general, our findings are consistent with what we know about cross-placental transfer of antibodies to other viruses, and should contribute to the discussion about whether and when to vaccinate pregnant women against SARS-CoV-2,” said co-senior author Scott Hensley, PhD, an associate professor of Microbiology at Penn Medicine and a member of the Penn Institute for Immunology.

Prior, smaller studies also have found evidence that maternal antibodies can cross the placenta to the fetal bloodstream. However, the dynamics and the efficiency of this transfer have been unclear.

Puopolo and Hensley and their colleagues used a previously validated blood test kit to check for SARS-CoV-2-specific antibodies in blood serum samples collected at the time of delivery during a four-month period from April to August of last year at Pennsylvania Hospital in Philadelphia. The study in all covered 1,471 mother-and-child pairs of samples.

About 6 percent of the women, 83 in all, showed significant SARS-CoV-2 antibody levels on the tests. Of their 83 newborns, 72 (87 percent) also showed significant SARS-CoV-2 antibody levels.

The researchers found that the most common class of antibodies in the blood, known as immunoglobulin G (IgG) antibodies, appeared to transfer readily from the mother’s blood across the placenta. IgG anti-SARS-CoV-2 levels detected in the newborns closely tracked levels in their mothers.

However, a class of larger antibodies, known as IgM antibodies, which tend to be produced earlier in an infection and are not known to cross the placenta, were not detected in any cord blood sample. Since infants have some ability to produce their own IgM antibodies, the absence of these antibodies also suggested that the SARS-CoV-2 virus itself had not crossed the placenta and infected them. Among the mothers who had anti-SARS-CoV-2 antibodies but their infants didn’t, 5 had only IgM antibodies, which would not have been expected to cross the placenta. The other 6 had low levels of IgG antibodies. COVID-19 vaccines are generally designed to elicit high levels of IgG antibodies against the virus.

The transport of IgG antibodies across the placenta is known to occur especially in the third trimester of pregnancy, and as more time passes, more antibodies cross. Scientists also know that an infection with a novel virus can take time to elicit a significant antibody response. The results from Hensley, Puopolo and their colleagues were consistent with these known patterns: placental transfer was greater the longer the time elapsed between maternal COVID-19 infection and delivery.

Other co-authors of the study were co-first authors Dustin Flannery and Sigrid Gouma; and Miren Dhudasia, Sagori Mukhopadhyay, Madeline Pfeifer, Emily Woodford, Jourdan Triebwasser, Jeffrey Gerber, Jeffrey Morris, Madison Weirick, Christopher McAllister, Marcus Bolton, Claudia Arevalo, Elizabeth Anderson, and Eileen Goodwin.

Funding was provided by the Children’s Hospital of Philadelphia Foerderer Grant for Excellence and philanthropic support from Philadelphia 76ers star player Joel Embiid and managing partners Josh Harris and David Blitzer, and Philadelphia Eagles owner Jeffrey Lurie.

Reference: Dustin D. Flannery, Sigrid Gouma, Miren B. Dhudasia, Sagori Mukhopadhyay, Madeline R. Pfeifer, Emily C. Woodford, Jourdan E. Triebwasser, Jeffrey S. Gerber, Jeffrey S. Morris, Madison E. Weirick, Christopher M. McAllister, Marcus J. Bolton, Claudia P. Arevalo, Elizabeth M. Anderson, Eileen C. Goodwin, Scott E. Hensley, Karen M. Puopolo, “Assessment of Maternal and Neonatal Cord Blood SARS-CoV-2 Antibodies and Placental Transfer Ratios”, JAMA Pediatr. Published online January 29, 2021. doi:10.1001/jamapediatrics.2021.0038

Provided by Penn Medicine

About Penn Medicine

Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System, which together form a $8.6 billion enterprise.

The Perelman School of Medicine has been ranked among the top medical schools in the United States for more than 20 years, according to U.S. News & World Report’s survey of research-oriented medical schools. The School is consistently among the nation’s top recipients of funding from the National Institutes of Health, with $494 million awarded in the 2019 fiscal year.

The University of Pennsylvania Health System’s patient care facilities include: the Hospital of the University of Pennsylvania and Penn Presbyterian Medical Center—which are recognized as one of the nation’s top “Honor Roll” hospitals by U.S. News & World Report—Chester County Hospital; Lancaster General Health; Penn Medicine Princeton Health; and Pennsylvania Hospital, the nation’s first hospital, founded in 1751. Additional facilities and enterprises include Good Shepherd Penn Partners, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is powered by a talented and dedicated workforce of more than 43,900 people. The organization also has alliances with top community health systems across both Southeastern Pennsylvania and Southern New Jersey, creating more options for patients no matter where they live.

Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2019, Penn Medicine provided more than $583 million to benefit our community.

Psychiatry

Why Do Psychiatric Drugs Help Some, But Not Others? New Study Offers Clues (Psychiatry)

Leave a comment

When it comes to developing drugs for mental illnesses, three confounding challenges exist:

Men and women experience them differently, with things like depression and anxiety far more common in females.

A drug that works for one person may not work for another, and side effects abound.

New CU Boulder research, published in the journal eLIfe, sheds light on one reason those individual differences may exist. Turns out a key protein in the brain called AKT may function differently in males than females. The study also offers a closer look at where, precisely, in the brain things may go wrong with it, marking an important step toward more targeted and less harmful therapies.

“The ultimate goal is to find the kink in the armor of mental illness—the proteins in the brain that we can specifically target without impacting other organs and causing side effects,” says Charles Hoeffer, an assistant professor of integrative physiology at the Institute for Behavioral Genetics. “Personalization is also key. We need to stop hitting every mental illness with the same hammer.”

The stuff memories are made of

Discovered in the 1970s and best known for its potential role in causing cancer when mutated, AKT has more recently been identified as a key player in promoting “synaptic plasticity.” That’s the brain’s ability to strengthen connections between neurons in response to experience.

“Let’s say you see a shark and you’re scared and your brain wants to form a memory. You have to make new proteins to encode that memory,” explains Hoeffer.  

AKT is one of the first proteins to come online, cranking the gears up on a host of downstream proteins in that memory factory. Without it, researchers have suspected, we can’t learn new memories or extinguish old ones to make room for new, less harmful ones.

Previous studies have linked mutations in the AKT gene to a host of problems, from schizophrenia and post-traumatic stress disorder to autism and Alzheimer’s.

We need to stop hitting every mental illness with the same hammer.

– Charles Hoeffer

But, as Hoeffer’s previous research has discovered, not all AKTs are created equal:

Different flavors, or isoforms, function differently in the brain. For instance, AKT2 found exclusively in the star-shaped brain cells called astroglia, is often implicated in brain cancer.

AKT3 appears to be important for brain growth and development. And AKT1, in combination with AKT2 in the prefrontal cortex of the brain, appears to be critical for learning and memory.

“These subtle differences could be really important if you wanted to personalize treatments for people,” explains Marissa Ehringer, an associate professor of integrative physiology who partnered with Hoeffer on some of the research.

Gender matters

Three years in the making, the new study adds an important new wrinkle to the story. Following National Institutes of Health guidelines that in the past six years began to require researchers to include both male and female animals in studies, it looked closely at how different gendered mice responded to the loss of various AKT isoforms.

“We found the difference between males and females to be so great it became the focus of our work,” Hoeffer said. “It was like night and day.”

For instance, male mice whose AKT1 was functioning normally were much better than those missing the protein when it came to “extinction learning” – replacing an old memory, or association, that’s not useful any more. (Imagine letting go of the memory of your favorite route home from work because you’ve moved, or disassociating a loud sound with danger).

For female mice, it didn’t make much of a difference.

Far more research is needed and underway, but Hoeffer suspects many other key proteins in the brain share similar nuances – with different flavors serving different purposes or acting differently in men and women.

With one in five U.S. adults living with mental illness and women as much as four times as likely to experience it during their lifetimes, he hopes that by disentangling all those nuances, he can move the dial toward better, safer treatments.

“To help more people suffering from mental illness we need much more knowledge about the difference between male and female brains and how they could be treated differently,” Hoeffer said. “This study is an important step in that direction.”

Reference: Helen Wong et al., “Isoform-specific roles for AKT in affective behavior, spatial memory, and extinction related to psychiatric disorders”, Neuroscience, 2020. DOI: 10.7554/eLife.56630 https://elifesciences.org/articles/56630#content

Provided by University of Colorado, Boulder

Medicine

Breast Cancer Risk More Accurate After Genetic Test (Medicine)

Leave a comment

Leiden University Medical Center (LUMC) has spent the past five years coordinating an international study of genetic mutations and breast cancer risks. The results will make it easier to determine which genes increase the risk of breast cancer and to what extent. The researchers published their results in the New England Journal of Medicine.

Peter Devilee, Professor of Genetics of Cancer at the LUMC. © Leiden University

‘Women around the world who think they may have a higher risk of developing breast cancer, for example because of a family history, can be tested to see if they carry a genetic mutation,’ explains Peter Devilee, Professor of Genetics of Cancer. This is done in diagnostic laboratories with what is known as a multigene panel test, which determines whether several breast cancer genes contain a genetic mutation.

Uncertainty about breast cancer risk

‘Women in the Netherlands can be tested for five breast cancer genes. These obviously include the familiar BRCA1 and BRCA2 genes, but more recently PALB2, CHEK2 and ATM too,’ Devilee explains. ‘For these genes we have a fairly good idea of the breast cancer risk, but this still isn’t very accurate. With the latter three genes, it is particularly difficult to interpret the test in terms of the exact level of the risk of breast cancer.’

It is known that other genes may also influence the risk of breast cancer. ‘The aim of our research was to estimate more accurately the risks relating to the five known breast cancer genes and to research whether other genes –and if so which ones – also increase the risk so that we can possibly expand the test.’

Accurate estimate

All the university medical centres in the Netherlands took part in this study as did the Antoni van Leeuwenhoek hospital. This was through the ‘Hebon’ research network. The international partners in the study tested 34 potential breast cancer genes in more than 60,000 breast cancer patients and 53,000 healthy women.

The results confirm that the five genes that are tested in the Netherlands are at present the most important breast cancer genes. The researchers were also able to provide a more-accurate estimate of the associated breast cancer risk, which will enable clinical geneticists to give clearer advice on the risks. The results also showed that 19 genes are not involved in breast cancer, and that although it was clear that seven other genes can increase the risk of breast cancer, this is nonetheless quite rare.

Greater clarity

The results therefore support current Dutch policy to provide women with results for the five known genes. Clinical geneticists will include the new information in their advice more or less immediately. They will be able to use the more-accurate risk estimates to tailor each test result to the individual woman. ‘The results also provide evidence for the potential expansion of the test,’ says Devilee. ‘In short, thanks to this study women around the world who undergo a multigene panel test will have a much better idea of where they stand.’

Read the full article: Breast Cancer Risk Genes — Association Analysis in More than 113,000 Women.

Provided by University of Leiden

Medicine

Heartburn Or Heart Attack? (Medicine)

Leave a comment

A big meal may cause heartburn or aggravate chronic acid reflux but sometimes the symptoms aren’t what you’d expect. How do you tell the difference between chest pain from heartburn and a heart attack? According to Baylor College of Medicine gastroenterologist Dr. Suneal Agarwal, it starts with knowing your body and your risk for both conditions.

“If there are factors that suggest you may have heart disease, such as family history, smoking, diabetes or hypertension, then you should seek care to address the heart right away,” said Agarwal, assistant professor of medicine – gastroenterology at Baylor. “Traditional heartburn is more of a burning sensation rather than a true pressure sensation, but often it is hard to tell the difference.”

Reflux happens when an abnormal amount of stomach acid enters the esophagus. Typical symptoms include heartburn (a burning feeling in the chest or throat), regurgitation (the sensation that stomach fluids are backing up into the throat) and difficulty swallowing. But some patients may present with less typical symptoms such as coughing, wheezing or chest pain that some may describe as comparable to a heart attack.

Pressure and pain due to reflex usually begin about 30-45 minutes after a meal. People with reflux disease may notice a pattern of heartburn after meals.

“If patients are having reflux episodes occurring more than 2-3 times a week, they should seek consultation with a gastroenterologist or their primary care physician,” Agarwal said.

Lifestyle changes can help address reflux disease. Agarwal recommends weight loss, avoiding meals before bed and refraining from lying down after a meal. Certain foods like citrus, chocolate, fatty foods, spicy food, alcohol, caffeine, carbonated beverages and peppermint may trigger reflux, and people can modify their diets to help improve symptoms. There also are medications like proton-pump inhibitors, histamine blockers and antacids that can decrease or neutralize stomach acid.

Seeing a doctor is important for patients whose condition does not improve with these treatments. It is important to assess any complications due to reflux and rule out other serious conditions.

“If a patient develops reflux symptoms suddenly after the age of 45 or has what we refer to as red flag symptoms (weight loss, trouble swallowing, family history of esophageal or gastric cancer), they should see a gastroenterologist,” Agarwal said.

Provided by Baylor College of Medicine

Medicine

Heart Disease Remains the Leading Cause of Death Worldwide (Medicine)

Leave a comment

Heart disease remains the leading cause of death worldwide, according to the 2021 Statistical Update from the American Heart Association, written by a collaboration of healthcare professionals led by Dr. Salim Virani, professor of medicine – cardiology at Baylor College of Medicine and a staff cardiologist at the Michael E. DeBakey Veterans Affairs Medical Center. Experts believe these numbers will be impacted by COVID-19 in the coming years.  

Virani chairs the committee made up of expert volunteers working on behalf of the American Heart Association’s Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee. He also is lead author on the data published online today in the journal Circulation.

The report found that globally, nearly 18.6 million people died of cardiovascular disease in 2019 (latest data recorded). Over the past decade, the number of deaths has increased 17.1%. There were more than 523.2 million cases of cardiovascular disease in 2019, an increase of 26.6% compared with 2010.

Virani and his colleagues say the impact of COVID-19 on cardiovascular disease is not entirely known at this time, but it is expected to play a role in cardiovascular health and mortality rates for many years.

“This could be caused directly by the virus, as well as a result of increased lifestyle-related risks during and after the pandemic,” Virani said. “Research is showing that the unique coronavirus can cause damage to the heart. Importantly, we also know people have delayed getting care for heart attacks and strokes, which can result in poorer outcomes.” Read more about indirect effects of the pandemic on the heart here.

Lifestyle changes related to the extraordinary circumstances faced by almost everyone dealing with COVID-19, such as lack of physical activity, unhealthy eating habits, increased alcohol consumption and mental stress brought on by quarantine isolation, fear of the virus, job loss or financial stress, can adversely impact a person’s risk for cardiovascular health. He said these behavioral trends will need to be watched and addressed as the full ramifications will likely be felt in the coming years.

Another finding the group noted in the 2021 Statistical Update was the importance of maternal health complications and how those affect cardiovascular health of mothers and their babies.

Pregnancy complications, including hypertensive disorders, gestational diabetes, preterm births and small-for-gestational-age at birth deliveries, occur in 10% to 20% of all pregnancies in the U.S. Cardiovascular deaths are the most common cause (26.5%) of maternal death in the U.S.

“There can be long-term effects on offspring of women who suffer pregnancy-related complications. But we can also help impact the health of future generations because as we help women learn to reduce their cardiovascular risk, they’re likely to adopt healthier lifestyles. In turn, they can influence the health behaviors of their families,” Virani said.

The annual report tracks trends related to ideal cardiovascular health, social determinants of health, global cardiovascular health, cardiovascular health genetics and healthcare costs. It represents a compilation of the newest, most relevant statistics on heart disease, stroke and risk factors impacting cardiovascular health. Virani emphasized the importance of this surveillance as a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates and others seeking the best available data on these factors and conditions.

The U.S. data is gathered in conjunction with the National Institutes of Health and other government agencies, while the global trends are provided by the Global Burden of Disease Study from the Institute for Health Metrics and Evaluation at the University of Washington.

Co-authors are Alvaro Alonso, M.D., Ph.D.; Hugo J. Aparicio, M.D., M.P.H.; Emelia J. Benjamin, M.D., Sc.M.; Marcio S. Bittencourt, M.D., Ph.D., M.P.H.; Clifton W. Callaway, M.D., Ph.D.; April P. Carson, Ph.D., M.S.P.H.; Alanna M. Chamberlain, Ph.D., M.P.H.; Susan Cheng, M.D., M.M.Sc., M.P.H.; Francesca N. Delling, M.D., M.P.H.; Mitchell S.V. Elkind, M.D., M.S.; Kelly R. Evenson, Ph.D., M.S.; Jane F. Ferguson, Ph.D.; Deepak K. Gupta, M.D., M.S.CI.; Sadiya S. Khan, M.D., M.Sc.; Brett M. Kissela, M.D., M.S.; Kristen L. Knutson, Ph.D.; Chong D. Lee, Ed.D., M.Ed.; Tené T. Lewis, Ph.D.; Junxiu Liu, Ph.D.; Matthew Shane Loop, Ph.D.; Pamela L. Lutsey, Ph.D., M.P.H;  Jun Ma, M.D., Ph.D.; Jason Mackey, M.D.; Seth S. Martin, M.D., M.H.S.; David B. Matchar, M.D.; Michael E. Mussolino, Ph.D.; Sankar D. Navaneethan, M.D., M.S., M.P.H.; Amanda Marma Perak, M.D., M.S.; Gregory A. Roth, M.D.; M.P.H.; Zainab Samad, M.D.; Gary M. Satou,; M.D.; Emily B. Schroeder, M.D., Ph.D.; Svati H. Shah, M.D., M.H.S.; Christina M. Shay, Ph.D.; Andrew Stokes, Ph.D.; Lisa B. VanWagner, M.D., M.Sc.; Nae-Yuh Wang, Ph.D., M.S.; Connie W. Tsao, M.D., M.P.H. Author disclosures are in the manuscript.

Provided by Baylor College of Medicine

Astronomy

Optical Luminosity-Time Correlation for More Than 100 GRBs (Astronomy)

Leave a comment

A new correlation has been discovered in optical observations of gamma-ray bursts (GRBs) that may be the key to using GRBs as cosmological distance indicators. Under Dr. Dainotti mentorship (KIPAC alum, Assistant Professor at Jagiellonian University in Poland and Senior Research Scientist at the RIKEN iTHEMs in Japan and affiliated senior resear h scientist at Space Science Institute), Samantha Livermore (fourth-year physics major at Tufts University) investigated the “plateau emission” in optical GRB observations during Samantha’s internship at SLAC National Accelerator Laboratory and Stanford University through the SULI program during the summer of 2020. The work continued afterwards during Livermore’s thesis research until its publication.

Dainotti and Livermore worked with a large team of international collaborators located in US, Europe, Mexico and Australia to gather a sizable sample and conduct their rigorous statistical analysis. This research, a continuation of Dr. Dainotti’s previous work on the plateau emission of GRBs, features the largest sample of optical plateaus in the literature to date, and has been accepted to be published in the Astrophysical Journal Letters.

Figure 1. Examples of two light curves including the plateau emission. Credit: The Authors.

The “plateau emission”, a feature commonly found in X-ray observations of GRBs, has been the subject of much study in the GRB community in recent years. This feature takes place after the initial prompt emission of the GRB, and is followed by a steadily decaying afterglow as the GRB fades away. The most interesting features of the plateau emission, however, are the luminosity and time at which the plateau ends. These parameters make up the luminosity-time correlation in X-rays, which states that in log-log space, there is an anticorrelation between the luminosity and the time at the end of the plateau emission in X-ray observations of GRBs (Dainotti et al. 2008). This correlation has been tested against selection biases in collaboration with Professor Petrosian at Stanford University. Thus, encouraged by the intrinsic nature of this correlation, in this most recent work, Dainotti and Livermore find that this luminosity-time correlation also holds in optical observations, extending the correlation and its implications further across the electromagnetic spectrum.

The team studied 267 optical GRB light curves (mostly from the Neil Gehrels Swift Observatory) and found that 102 of them had well-defined plateaus by fitting the curves with a phenomenological model known as the Willingale model, shown in the left panel of Fig. 1. Once the plateaus are identified, the luminosity-time parameters of each GRB are gathered for a large statistical analysis. When the luminosity-time data is plotted for the entire sample, it is clear that the luminosity-time correlation could also be found in optical plateaus, as well as X-ray plateaus as had been shown previously (this correlation has a clear slope of -1 in log luminosity- log time space). This means that the more luminous the optical plateau, the shorter its duration. Given the slope of the correlation is nearly -1, this further supports that the plateau has a fixed energy reservoir independent of a given class and a possible explanation can be the magnetar model. The source of the dispersion of the correlation comes both from a physical point of view, depending on the energy mechanism underlying the plateau, and from an instrumental point of view.

Not only was the familiar X-ray correlation reproduced in optical observations, but the correlation was found to be constant even in different sub-samples of GRBs. When the 102 GRBs were divided by classification, and plateau inclination, the correlation did not vary significantly, showing that the optical luminosity-time correlation holds across a varied population of GRBs.

This correlation implies that the energy reservoir of the GRB is constant during the plateau emission, which aids astrophysicists in unifying a large and varied population of GRB events. It is an extremely interesting and challenging task to standardize groups of GRBs in order to take advantage of their incredible luminosity and use them as standard candles. GRBs have been observed up to redshifts of z ≈ 8.2, making them attractive candidates for use as cosmological distance indicators, since they reach further back in time than the current most popular standard candles, Supernova Ia, observed up to z < 2.3.

Figure 2. Plot of the optical luminosity-time correlation. Credit: The Authors.

The problem, however, is that GRB varies in duration, brightness, progenitor system, and morphological features. In order to use GRBs to measure distances in the universe, we need better understand their emission mechanisms and find features that unite their larger population —this is why the existence of the luminosity-time correlation in optical plateaus is so crucial. Looking at relationships between observable parameters of the plateau helps to define intrinsic patterns that could unify a diverse population of GRBs.

The main finding of the paper is that the Gold Sample, defined as the GRBs with almost relatively flat plateaus and at least with 5 points at the beginning of the plateau itself, has a reduced dispersion around the best fit line which is 52.4% smaller than the whole sample. The slopes of the X-ray and optical luminosity-time correlation are comparable within 1σ. The researchers were able to obtain a reduced scatter when considering light curves belonging to the Gold Sample.

Presented results are a part of research conducted at the Department of High Energy Astrophysics of the Jagiellonian University’s Astronomical Observatory.

Featured image: Green dots show the locations of 186 gamma-ray bursts observed by the Large Area Telescope (LAT) on NASA’s Fermi satellite during its first decade. Some noteworthy bursts are highlighted and labeled. Background: Constructed from nine years of LAT data, this map shows how the gamma-ray sky appears at energies above 10 billion electron volts. The plane of our Milky Way galaxy runs along the middle of the plot. Credits: NASA/DOE/Fermi LAT Collaboration.

Reference: M.G. Dainotti, S. Livermore, D.A. Kann, L. Li, S. Oates, S. Yi, B. Zhang, B. Gendre, B. Cenko, N. Fraija: The Optical Luminosity-Time Correlation for More Than 100 Gamma-Ray Burst Afterglows, ApJS, 238, 9, 2018.

Provided by Astronomical Observatory of the Jagiellonian University