BLOGS

Plastic chokes a canal in Chennai, India. Credit: R. Satish Babu/AFP via Getty

Topics: Applied Physics, Biology, Chemistry, Environment, Medicine

People who had tiny plastic particles lodged in a key blood vessel were more likely to experience heart attack, stroke or death during a three-year study.

Plastics are just about everywhere — food packaging, tyres, clothes, water pipes. And they shed microscopic particles that end up in the environment and can be ingested or inhaled by people.

Now, the first data of their kind show a link between these microplastics and human health. A study of more than 200 people undergoing surgery found that nearly 60% had microplastics or even smaller nanoplastics in a main artery¹. Those who did were 4.5 times more likely to experience a heart attack, a stroke, or death in the approximately 34 months after the surgery than were those whose arteries were plastic-free.

“This is a landmark trial,” says Robert Brook, a physician-scientist at Wayne State University in Detroit, Michigan, who studies the environmental effects on cardiovascular health and was not involved with the study. “This will be the launching pad for further studies across the world to corroborate, extend, and delve into the degree of the risk that micro- and nanoplastics pose.”

But Brook, other researchers and the authors themselves caution that this study, published in The New England Journal of Medicine on 6 March, does not show that the tiny pieces caused poor health. Other factors that the researchers did not study, such as socio-economic status, could be driving ill health rather than the plastics themselves, they say.

Landmark study links microplastics to serious health problems, Max Kozlov, Nature.

PAC1R-expressing dorsal raphe neurons in the mouse brain (red) serve as the projection targets for PACAP parabrachial neurons to mediate panic-like behavioral and physical symptoms. Credit: Salk Institute

Topics: Biology, Medicine, Research, Science

Overwhelming fear, sweaty palms, shortness of breath, rapid heart rate—these are the symptoms of a panic attack, which people with panic disorder have frequently and unexpectedly. Creating a map of the regions, neurons, and connections in the brain that mediate these panic attacks can provide guidance for developing more effective panic disorder therapeutics.

Now, Salk researchers have begun to construct that map by discovering a brain circuit that mediates panic disorder. This circuit consists of specialized neurons that send and receive a neuropeptide—a small protein that sends messages throughout the brain—called PACAP. What's more, they determined that PACAP and the neurons that produce its receptor are possible druggable targets for new panic disorder treatments.

The findings were published in Nature Neuroscience.

"We've been exploring different areas of the brain to understand where panic attacks start," says senior author Sung Han, associate professor at Salk.

"Previously, we thought the amygdala, known as the brain's fear center, was mainly responsible—but even people who have damage to their amygdala can still experience panic attacks, so we knew we needed to look elsewhere. Now, we've found a specific brain circuit outside of the amygdala that is linked to panic attacks and could inspire new panic disorder treatments that differ from currently available panic disorder medications that typically target the brain's serotonin system."

Scientists uncover key brain pathway mediating panic disorder symptoms, Salk Institute.

Figure 2. mRNA contains four different bases, abbreviated A, U, G, and C. The Nobel Laureates discovered that base-modified mRNA can be used to block the activation of inflammatory reactions (secretion of signaling molecules) and increase protein production when mRNA is delivered to cells. © The Nobel Committee for Physiology or Medicine. Ill. Mattias Karlén

Topics: COVID-19, Medicine, Nobel Laureate, Nobel Prize, Physiology

Press Release

2023-10-02

The Nobel Assembly at Karolinska Institutet

has today decided to award

the 2023 Nobel Prize in Physiology or Medicine

jointly to

Katalin Karikó and Drew Weissman

for their discoveries concerning nucleoside base modifications that enabled the development of effective mRNA vaccines against COVID-19

The discoveries by the two Nobel Laureates were critical for developing effective mRNA vaccines against COVID-19 during the pandemic that began in early 2020. Through their groundbreaking findings, which have fundamentally changed our understanding of how mRNA interacts with our immune system, the laureates contributed to the unprecedented rate of vaccine development during one of the greatest threats to human health in modern times.

mRNA vaccines: A promising idea

In our cells, genetic information encoded in DNA is transferred to messenger RNA (mRNA), which is used as a template for protein production. During the 1980s, efficient methods for producing mRNA without cell culture were introduced, called in vitro transcription. This decisive step accelerated the development of molecular biology applications in several fields. Ideas of using mRNA technologies for vaccine and therapeutic purposes also took off, but roadblocks lay ahead. In vitro transcribed mRNA was considered unstable and challenging to deliver, requiring the development of sophisticated carrier lipid systems to encapsulate the mRNA. Moreover, in vitro-produced mRNA gave rise to inflammatory reactions. Enthusiasm for developing the mRNA technology for clinical purposes was, therefore, initially limited.

These obstacles did not discourage the Hungarian biochemist Katalin Karikó, who was devoted to developing methods to use mRNA for therapy. During the early 1990s, when she was an assistant professor at the University of Pennsylvania, she remained true to her vision of realizing mRNA as a therapeutic despite encountering difficulties in convincing research funders of the significance of her project. A new colleague of Karikó at her university was the immunologist Drew Weissman. He was interested in dendritic cells, which have important functions in immune surveillance and the activation of vaccine-induced immune responses. Spurred by new ideas, a fruitful collaboration between the two soon began, focusing on how different RNA types interact with the immune system.

(Credit: DoruqpashA/Shutterstock)

Topics: Education, Existentialism, History, Medicine, Nuclear Power

21st-century weather models show how radioactive fallout from atmospheric nuclear tests spread more widely than thought across the US

The Trinity Nuclear Test on 16 July 1945 is a key incident in the blockbuster Oppenheimer movie and in the history of humankind. Many scientists think it marks the beginning of the Anthropocene, a new geological era characterized by humanity’s influence on the Earth. That’s because Trinity’s radioactive fallout will forever appear in the geological record, creating a unique signature of human activity that can be precisely dated.

But there’s a problem. In 1945, radioactive monitoring techniques were in their infancy, so there are few direct measurements of fallout beyond the test site. What’s more, weather patterns were also less well understood, so the spread of fallout could not be easily determined.

As a result, nobody really knows how widely Trinity’s fallout spread across the U.S. or, indeed, how the fallout dispersed from other atmospheric nuclear tests on the U.S. mainland.

Nuclear Mystery

Today, that changes thanks to the work of Sébastien Philippe at Princeton University and colleagues. This team used a state-of-the-art weather simulation for the 5 days after each nuclear test to simulate how the fallout would have dispersed.

The result is the highest resolution estimate ever made of the spread of radioactive fallout across the U.S. It marks the start of the Anthropocene with extraordinary precision, and it throws up some significant surprises. Some parts of the U.S. are known to have received high levels of fallout, and the new work is consistent with this. But the research also reveals some parts of the US that received significant fallout without anybody realizing it.

The findings “provide an opportunity for re-evaluating the public health and environmental implications from atmospheric nuclear testing,” said Philippe and co.

Between 1945 and 1962, the U.S. conducted 94 atmospheric nuclear tests that generated yields of up to 74 kilotons of TNT. (Seven other tests were damp squibs.) 93 of these tests took place in Nevada, but the first, the Trinity test in the Oppenheimer film, took place in New Mexico.

How The Trinity Nuclear Test Spread Radioactive Fallout Across America, the Physics arXiv Blog, Discover Magazine

New research from Chalmers University of Technology, Sweden, and the University of Freiburg, Germany, shows that wounds on cultured skin cells heal three times faster when stimulated with electric current. The project was recently granted more funding so the research can get one step closer to the market and the benefit of patients. Credit: Science Brush, Hassan A. Tahin

Topics: Applied Physics, Biotechnology, Medicine

Chronic wounds are a major health problem for diabetic patients and the elderly—in extreme cases, they can even lead to amputation. Using electric stimulation, researchers in a project at Chalmers University of Technology, Sweden, and the University of Freiburg, Germany, have developed a method that speeds up healing, making wounds heal three times faster.

There is an old Swedish saying that one should never neglect a small wound or a friend in need. For most people, a small wound does not lead to any serious complications, but many common diagnoses make wound healing far more difficult. People with diabetes, spinal injuries, or poor blood circulation have impaired wound-healing ability. This means a greater risk of infection and chronic wounds—which can lead to serious consequences like amputation in the long run.

Now a group of researchers at Chalmers and the University of Freiburg have developed a method using electric stimulation to speed up the healing process. The study, "Bioelectronic microfluidic wound healing: a platform for investigating direct current stimulation of injured cell collectives," was published in the Lab on a Chip journal.

"Chronic wounds are a huge societal problem that we don't hear much about. Our discovery of a method that may heal wounds up to three times faster can be a game changer for diabetic and elderly people, among others, who often suffer greatly from wounds that won't heal," says Maria Asplund, Associate Professor of Bioelectronics at the Chalmers University of Technology and head of research on the project.

How electricity can heal wounds three times faster, The Chalmers University of Technology

Topics: Diversity in Science, Education, Medicine, Research, STEM

AAAS will bring together a diverse group of professionals in science, technology, engineering, mathematics, and medicine (STEMM) to tackle the barriers to individuals entering and staying in careers in those fields.

The first Multidisciplinary Working Group (MWG), called Empowering Career Pathways in STEMM (ECP), will focus on developing recommendations that acknowledge and value the variety of professional journeys that contribute equally to the scientific enterprise.

“We need to abandon the idea of a so-called gold standard for what a STEMM career looks like and outdated notions of success that have resulted in excluding and losing talent and, more importantly, potential,” said Julie Rosen, AAAS’ director of strategic initiatives, who was brought on board to launch and oversee the MWGs.

Some of the major barriers to individuals entering STEMM careers and challenges to retaining talent include exclusionary practices that limit access to career opportunities, disincentives for those wanting to make career changes, unrealistic goals for success, and disconnects between formal training and on-the-job competencies.

“The landscape that early-career scientists are facing is nebulous and, for those coming from communities or backgrounds that are underrepresented in STEMM, it can seem insurmountable,” said Gilda Barabino, chair of the AAAS Board of Directors and president of Olin College of Engineering. “By identifying ways to reimagine how a career in science or engineering may play out, the first AAAS working group will empower multiple paths that can help strengthen the STEMM enterprise.”

Inaugural AAAS Multidisciplinary Working Group to Focus on STEMM Workforce Development

Image Link: NobelPrizeMedicine.org

Topics: Medicine, Nobel Laureate, Nobel Prize

Press release

2022-10-03

The Nobel Assembly at Karolinska Institutet

has today decided to award

the 2022 Nobel Prize in Physiology or Medicine

to

Svante Pääbo

for his discoveries concerning the genomes of extinct hominins and human evolution

Humanity has always been intrigued by its origins. Where do we come from, and how are we related to those who came before us? What makes us, Homo sapiens, different from other hominins?

Through his pioneering research, Svante Pääbo accomplished something seemingly impossible: sequencing the genome of the Neanderthal, an extinct relative of present-day humans. He also made the sensational discovery of a previously unknown hominin, Denisova. Importantly, Pääbo also found that gene transfer had occurred from these now extinct hominins to Homo sapiens following the migration out of Africa around 70,000 years ago. This ancient flow of genes to present-day humans has physiological relevance today, for example affecting how our immune system reacts to infections.

Pääbo’s seminal research gave rise to an entirely new scientific discipline; paleogenomics. By revealing genetic differences that distinguish all living humans from extinct hominins, his discoveries provide the basis for exploring what makes us uniquely human.

Press release: The Nobel Prize in Physiology or Medicine 2022. NobelPrize.org. Nobel Prize Outreach AB 2022. Mon. 3 Oct 2022. <https://www.nobelprize.org/prizes/medicine/2022/press-release/>

Magnetic prosthetic: A magnetic sensing array enables a new tissue tracking strategy that could offer advanced motion control in artificial limbs. (Courtesy: MIT Media Lab/Cameron Taylor/Vessel Studios)

Topics: Biotechnology, Magnetism, Materials Science, Medicine, Nanotechnology, Robotics

Cultural reference: The Six Million Dollar Man, NBC

In recent years, health and fitness wearables have gained popularity as platforms to wirelessly track daily physical activities, by counting steps, for example, or recording heartbeats directly from the wrist. To achieve this, inertial sensors in contact with the skin capture the relevant motion and physiological signals originating from the body.

As wearable technology evolves, researchers strive to understand not just how to track the body’s dynamic signals, but also how to simulate them to control artificial limbs. This new level of motion control requires a detailed understanding of what is happening beneath the skin, specifically, the motion of the muscles.

Skeletal muscles are responsible for almost all movement of the human body. When muscle fibers contract, the exerted forces travel through the tendons, pull the bones, and ultimately produce motion. To track and use these muscle contractions in real-time and with high signal quality, engineers at the Massachusetts Institute of Technology (MIT) employed low-frequency magnetic fields – which pass undisturbed through body tissues – to provide accurate and real-time transcutaneous sensing of muscle motion. They describe their technique in Science Robotics.

Magnetic beads inside the body could improve control of bionic limbs, Raudel Avila is a student contributor to Physics World

Figure 1. Schematic illustration of the Hepatitis C virus. Top right: the virus particle containing an RNA genome and the viral envelope glycoproteins E1 and E2 exposed on the surface. Bottom: the viral genome encoding a large polyprotein that is cleaved into multiple structural and non-structural proteins with 5’ and 3’ terminal untranslated regions.

Topics: Medicine, Nobel Laureates, Nobel Prize

The discovery of Hepatitis C virus
The 2020 Nobel Prize in Physiology or Medicine is awarded to Harvey J. Alter, Michael Houghton, and Charles M. Rice for the discovery of Hepatitis C virus. Hepatitis, from the Greek names for liver and inflammation, is a disease characterized by poor appetite, vomiting, fatigue, and jaundice – yellow discoloration of the skin and eyes. Chronic hepatitis leads to liver damage, which may progress to cirrhosis and liver cancer. Viral infection is the leading cause of hepatitis, with some forms persisting without symptoms for many years before life-threatening complications develop. Until the 1960s, exposure to blood from infected individuals was a major health hazard, with up to 30% risk of chronic hepatitis following surgery or multiple blood transfusions. This risk was only partially reduced by the discovery of the Hepatitis B virus (HBV) and the eventual elimination of HBV-contaminated blood through testing. A more insidious form of hepatitis, characterized by very mild symptoms in the acute phase and a high risk of progression to chronic liver damage and cancer, remained. The work of Alter, Houghton, and Rice characterized this form of hepatitis to be a distinct clinical entity, caused by an RNA virus of the Flavivirus family, now known as Hepatitis C virus (HCV). This pioneering work has paved the way for the development of screening methods that have dramatically reduced the risk of acquiring hepatitis from contaminated blood and has led to the development of effective antiviral drugs that have improved the lives of millions of people.

Advanced information. NobelPrize.org. Nobel Media AB 2020. Mon. 5 Oct 2020. <https://www.nobelprize.org/prizes/medicine/2020/advanced-information/>