Millions of girls fall out of love with sports by teens

Body image, puberty and fear of judgement are among the reasons girls drop out of sport, a study reveals.

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Covid in Scotland: Fourth jab rolled out for most vulnerable

Care home residents, over-75s and people with reduced immunity are offered Spring boosters

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New discovery may help reduce side effects of multiple sclerosis drugs

Investigators from Weill Cornell Medicine and Memorial Sloan Kettering Cancer Center have discovered how a drug for multiple sclerosis interacts with its targets, a finding that may pave the way for better treatments.

The study, published Feb. 8 in Nature Communications, details the precise molecular structure of the multiple sclerosis drug siponimod as it interacts with its target, the human S1P receptor 1 (S1P1), and off-target receptors using a cutting-edge electron microscopy technique called cryo-EM. This knowledge could help scientists develop drugs for the disease that are less likely to miss their targets.

“This discovery will help us improve drugs for multiple sclerosis and reduce their side effects,” said the study’s co-senior author Dr. Xin-Yun Huang, professor of physiology and biophysics at Weill Cornell Medicine.

In patients with multiple sclerosis, immune cells called lymphocytes attack and destroy the protective sheath around nerve cells, causing progressive neurologic symptoms. Scientists developed immune-suppressing drugs that block the release of these lymphocytes from the lymph nodes by binding to S1P1 receptors. But the first-generation version of these drugs could also bind to related receptors including S1P3, which caused unwanted side effects including an abnormal heart rhythm. To address this problem, scientists created next-generation medications like siponimod that bind more selectively to S1P1 and another receptor called S1P5. But this didn’t eliminate all unwanted side effects.

The new study, co-led by Dr. Shian Liu, a research associate at Weill Cornell Medicine, and Navid Paknejad, a graduate student at Memorial Sloan Kettering, reveals how siponimod binds to these two receptors and the features of the molecule that prevent it from binding to unwanted targets like S1P2, S1P3 and S1P4. Scientists can use this information to modify the drug to help it attach more tightly to its target (S1P1) and less likely to bind with unintended target (S1P5), reducing the risk of side effects.

“This new structural information will help us develop the next generation of multiple sclerosis drugs,” Dr. Huang said.

The study also helps explain how naturally occurring lipids can regulate the immune system, the nervous system and lung function. The team found that nearly identical lipids called sphingosine 1-phosphate and lysophosphatidic acid assumed very different shapes when bound to their target receptors.

“Lipids are highly plastic molecules, and the structures reveal how the receptors leverage subtle differences in the lipids structures to discriminate between them,” said co-senior author Dr. Richard Hite, a structural biologist at Memorial Sloan Kettering and an assistant professor in the biochemistry and structural biology and the physiology, biophysics and systems biology programs at the Weill Cornell Graduate School of Medical Sciences.

“This explains how lipids can play very different roles in the body even though their chemical structures are very similar,” Dr. Huang said.

The finding highlights the importance of carefully designing lipid-based drugs to prevent them from missing their targets. “We need to make lipid-based drugs that are very specific to reduce the risk of side effects,” he said.

These new insights may help scientists develop improved treatments for other autoimmune diseases like inflammatory bowel disease, psoriasis and systemic lupus. They might also help scientists create lipid-based therapies for conditions that affect the brain or lungs. For example, Dr. Huang noted that there are currently lipid-based drugs in clinical trials to reduce lung stiffening in patients with COVID-19.

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Scientists identify areas of high marine mammal diversity

Sightings of more than 1 million marine mammals in the federally protected Northeast Canyons and Seamounts Marine National Monument and sites along the Atlantic Coast have been used to identify areas of high marine mammal diversity. These findings underscore the importance of ocean conservation as these waters face increasing impacts from human activities.

In a new study published in Conservation Science and Practice, New England Aquarium scientists reviewed marine mammal sightings to gain a better understanding of habitat use along the U.S. East Coast. The research team used North Atlantic Right Whale Consortium data from aerial and boat surveys conducted by 49 organizations between 1979 and 2020 to calculate marine mammal species diversity in the North Atlantic Ocean between Florida and Nova Scotia, Canada. The data set contained 189,175 sightings of more than 1 million animals from 30 unique species or species groupings.

High species diversity occurred more frequently in the northern part of the Atlantic Coast, particularly around the Monument, on the edge of the continental shelf, and across the Gulf of Maine and Georges Bank, they found. “It was very exciting to see these results,” said Brooke C. Hodge, the study’s lead author and Associate Scientist in the Spatial Ecology, Mapping, and Assessment (EcoMap) Program for the Anderson Cabot Center for Ocean Life at the New England Aquarium.. “Our research shows us that the Monument is diverse compared to the East Coast. It is clearly well-sited and protects a unique and diverse marine mammal community.”

Last October, the Biden-Harris Administration reinstated the Monument’s federal protection status, which had been removed by the previous administration. The nearly 5,000-square mile underwater sanctuary is located 130 miles southeast of Cape Cod and is home to vibrant deep-sea ecosystems that include coral reefs, fish, and endangered whales. In 2016, Aquarium scientists provided strong scientific evidence that helped the Monument’s initial designation under President Obama. In 2021, Aquarium scientists explored the consequences of removing protections from the Monument and demonstrated that opening the Monument to fishing increased the risk of entanglement, bycatch, and habitat destruction for species from the sea surface to sea floor.

In this study, scientists found that species diversity was highest in the northern and mid-Atlantic regions with steep continental shelf edges. Canyons and areas with high salinity and low temperatures also had a high diversity of marine mammals. “Well designed and effectively managed marine protected areas can lead to conservation success,” Hodge said. In the study, the authors wrote: “Our analyses contribute to efforts to designate MPAs (marine protected areas) to conserve habitat that is important for protecting species by identifying drivers of biodiversity and potential sites for protecting 30 percent of the plant by 2030.” The Biden-Harris Administration aims to protect 30 percent of federal U.S. lands and waters by 2030.

“Identifying MPAs in our study area is critical because U.S. East Coast waters face intensive human use from fishing, shipping, planned wind energy development, and features that support marine mammal foraging are subject to specific threats,” researchers wrote in the study. “The Gulf of Maine is one of the most rapidly warming marine ecosystems in the world, and evidence of changes in productivity have already been observed. Designating MPAs and establishing effective management measures to meet the goal of protecting areas of particular importance to biodiversity are needed to protect marine mammals and the ecosystems on which they depend.” However, the authors acknowledge that further research is needed to more fully characterize marine mammal species diversity in these areas and to assess the biodiversity of the full wildlife community and the habitat, such as seabirds, deep-self invertebrates, deep-sea corals, sponges, and fish.

The study’s coauthors include several New England Aquarium scientists: Daniel E. Pendleton, Research Scientist; Laura C. Ganley, Postdoctoral Associate Research Scientist; Orfhlaith “Orla” O’Brien, Associate Scientist; Scott D. Kraus, Emeritus Scientist; and Jessica V. Redfern, Senior Scientist and Chair of the Spatial Ecology, Mapping, and Assessment Program. Ester Quintana-Rizzo of Simmons University also contributed to the research.

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Possible common thread between many neurodegenerative diseases

Take a cell-deep tour of a brain afflicted with Alzheimer’s disease, and you will find minuscule clumps of protein that seem suspicious. Ever since the 1980s, when neuroscientists began identifying these protein tangles, researchers have discovered that other brain diseases have their own tangled-protein signatures.

“Each of these diseases has a unique protein tangle, or fibril, associated with it,” said Anthony Fitzpatrick, PhD, principal investigator at Columbia’s Zuckerman Institute. “These proteins associated with diseases have their own shapes and behaviors,” added Dr. Fitzpatrick, also an assistant professor of biochemistry and molecular biophysics at Columbia University Irving Medical Center and a member of Columbia’s Taub Institute for Research on Alzheimer’s Disease and the Aging Brain.

Published today in Cell, the research by Dr. Fitzpatrick and an international team of 22 collaborators reveals a new fibril in diseased brains, one formed by a protein normally busy cleaning cells.

“We have a surprising and provocative result that we hope could have some bearing on managing neurodegenerative diseases,” said undergraduate Andrew Chang, a co-first author on the paper in the Fitzpatrick lab. Drug researchers have long pursued the tangle-forming proteins as targets for new medicines, but this pursuit so far has largely delivered disappointing results.

Fibril-associated diseases, some common and some rare, collectively affect millions of people around the world. Their incidence is slated to increase as the population grows and people live longer. Untangling what is going on in these neurodegenerative diseases has a personal facet for Dr. Fitzpatrick: He lost an uncle to one of them, progressive supranuclear palsy (PSP).

“We have found that a protein called TMEM106B can form fibrils, and this behavior was not known before,” said Xinyu Xiang, formerly a member of the Fitzpatrick lab at the Zuckerman Institute and now a graduate student at Stanford University’s Department of Structural Biology. “This protein is a core component of lysosomes and endosomes, which are organelles that clean up the junk that builds up in our cells as we get older.”

Normally, TMEM106B molecules span the membranes of those waste-management organelles. In a feat of laboratory sleuthing, Fitzpatrick’s team discovered that TMEM106B molecules can split into two fragments. Fragments inside the organelles can then self-assemble into what the researchers suspect could be cell-hobbling fibrils.

To make this discovery, the researchers first extracted proteins from brain tissue donated by 11 patients who had died from three neurodegenerative diseases associated with misfolded proteins: PSP, dementia with Lewy bodies (DLB) and frontotemporal lobar degeneration (FTLD). FTLD is the most prevalent form of dementia for those under 60 years of age.

“It’s so motivating to remember that the only way we can do this research is because of people who generously donated their brains,” said Marija Simjanoska, a co-first author and one of the three undergraduates working on the project.

Co-corresponding author Ian Mackenzie, MD, of the University of British Columbia, and co-authors Dennis Dickson, MD, and Leonard Pertrocelli, PhD, of the Mayo Clinic in Florida, helped procure this precious research resource. Joining Drs. Fitzpatrick and Mackenzie as co-corresponding authors on the paper is Michael Stowell, PhD, of the University of Colorado, Boulder. Filling out the 23-member team are researchers from several other institutions, including three in Belgium.

With a world-class cryogenic electron microscope (cryo-EM), the team took snapshots of individual protein molecules at many different angles. From these, the researchers constructed three-dimensional models of the protein in atomic detail. Those models, in turn, helped the researchers identify TMEM106B by making educated guesses about the exact sequence of the protein’s amino-acid building blocks. Much in the way letters string into words with specific meanings, different amino-acid molecules build into proteins, each with its own shape and function.

The researchers fully expected that one of the long-known fibril-forming proteins, such as the tau protein in Alzheimer’s disease, would end up matching with the models from the cryo-EM data. Instead, the matching exercise, which involved searching in a massive database of protein sequences, delivered a head-turning result.

The researchers found that the mysterious protein matched a 135-amino-acid fragment of TMEM106B. That was an exciting revelation because this same protein was identified more than a decade ago in a broad hunt for genes potentially associated with FTLD.

So far, the data in hand shows only that TMEM106B fibrils are present in diseased brain tissue, not that the fibrils cause the diseases. Still, Dr. Fitzpatrick points out, the prevalence of TMEM106B fibrils in tissue from different brain diseases, combined with the protein’s normal place in lysosomes and endosomes, points toward a possible disease-causing role.

In their Cell paper, the researchers speculate that the formation of TMEM106B fibrils disrupts lysosome function, which, in turn, promotes the formation of fibrils made of the other known fibril-forming proteins. These malfunctions could kill brain cells, leading to dementia, movement problems, speech pathologies and other symptoms of Alzheimer’s, PSP, FTLD and other brain diseases with telltale protein tangles.

“We now have a promising new lead,” said Dr. Fitzpatrick. “It could point towards a common thread linking a range of neurodegenerative diseases and could open the way to new interventions.”

This work was supported by the National Institutes of Health (NIH)/National Institute of Neurological Disorder and Stroke (UO1NS110438, U54NS110435); the Association for Frontotemporal Degeneration; Canadian Institutes of Health Research (74580); and MCDB Neurodegenerative Disease Fund.

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Event horizons are tunable factories of quantum entanglement

LSU physicists have leveraged quantum information theory techniques to reveal a mechanism for amplifying, or “stimulating,” the production of entanglement in the Hawking effect in a controlled manner. Furthermore, these scientists propose a protocol for testing this idea in the laboratory using artificially produced event horizons. These results have been recently published in Physical Review Letters, “Quantum aspects of stimulated Hawking radiation in an analog white-black hole pair,” where Ivan Agullo, Anthony J. Brady and Dimitrios Kranas present these ideas and apply them to optical systems containing the analog of a pair white-black hole.

Black holes are some of the most mystifying objects in our universe, largely due to the fact that their inner-workings are hidden behind a completely obscuring veil — the black hole’s event horizon.

In 1974, Stephen Hawking added more mystique to the character of black holes by showing that, once quantum effects are considered, a black hole isn’t really black at all but, instead, emits radiation, as if it was a hot body, gradually losing mass in the so-called “Hawking evaporation process.” Further, Hawking’s calculations showed that the emitted radiation is quantum mechanically entangled with the bowels of the black hole itself. This entanglement is the quantum signature of the Hawking effect. This astounding result is difficult, if not impossible, to be tested on astrophysical black holes, since the faint Hawking radiation gets overshined by other sources of radiation in the cosmos.

On the other hand, in the 1980’s, a seminal article by William Unruh established that the spontaneous production of entangled Hawking particles occurs in any system that can support an effective event horizon. Such systems generally fall under the umbrella of “analog gravity systems” and opened a window for testing Hawking’s ideas in the laboratory.

Serious experimental investigations into analog gravity systems — made of Bose-Einstein condensates, non-linear optical fibers, or even flowing water — have been underway for more than a decade. Stimulated and spontaneously-generated Hawking radiation has recently been observed in several platforms, but measuring entanglement has proved elusive due to its faint and fragile character.

“We show that, by illuminating the horizon, or horizons, with appropriately chosen quantum states, one can amplify the production of entanglement in Hawking’s process in a tunable manner,” said Associate Professor Ivan Agullo. “As an example, we apply these ideas to the concrete case of a pair of analog white-black holes sharing an interior and produced within a non-linear optical material.”

“Many of the quantum information tools used in this research were from my graduate research with Professor Jonathan P. Dowling,” said 2021 PhD alumnus Anthony Brady, postdoctoral researcher at the University of Arizona. “Jon was a charismatic character, and he brought his charisma and unconventionality into his science, as well as his advising. He encouraged me to work on eccentric ideas, like analog black holes, and see if I could meld techniques from various fields of physics — like quantum information and analog gravity — in order to produce something novel, or ‘cute,’ as he liked to say.”

“The Hawking process is one of the richest physical phenomena connecting seemingly unrelated fields of physics from the quantum theory to thermodynamics and relativity,” said Dimitrios Kranas, LSU graduate student. “Analog black holes came to add an extra flavor to the effect providing us, at the same time, with the exciting possibility of testing it in the laboratory. Our detailed numerical analysis allows us to probe new features of the Hawking process, helping us understand better the similarities and differences between astrophysical and analog black holes.”

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Materials provided by Louisiana State University. Note: Content may be edited for style and length.

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Meddling with metals: Escaping the tyranny of copper

It may seem counterintuitive to many, but metal ions play a critical role in life, carrying out some of the most important biological processes. Think of hemoglobin — a metalloprotein responsible for carrying oxygen to the body’s organs via red blood cells. Metalloproteins are proteins bound by at least one metal ion. In the case of hemoglobin, that metal is iron.

For metalloproteins to work properly, they must be paired with the correct metal ion — hemoglobin can only function with iron Yet, protein-metal binding is normally governed by a strict order, called the Irving-Williams Series, which dictates that copper ions should bind to proteins over other metals.

In other words, if a cell contained equal amounts of different metal ions, most cellular proteins and other components would bind to copper, clogging up cellular machinery in the process. This is why organisms spend considerable energy keeping very strict controls over how much free copper is present in cells.

Now researchers in the University of California San Diego’s Division of Physical Sciences have reported a new protein-design strategy to sidestep the Irving-Williams Series. The findings were published earlier this week in the journal Nature.

Professor of Chemistry and Biochemistry Akif Tezcan and postdoctoral scholar Tae Su Choi designed a flexible protein that selectively binds other metal ions over copper, paving the way for the design of novel functional proteins and metal sequestration agents. Choi and Tezcan discovered that selective binding to non-copper metals required the artificial protein to present a very specific combination of amino acids and geometries to discriminate against copper. This discovery required an uncommon design approach.

“Protein design typically involves trying to craft a discrete protein structure that can perform a certain function, such as catalysis. This approach is inherently deterministic and follows the sequence of one design-one structure-one function,” stated Tezcan. “Best case scenario, you obtain the structure and function that is designed. However, this approach doesn’t leave much room for the discovery of new design principles or unexpected outcomes, which are potentially more significant than what was originally planned.”

Tezcan and Choi took a probabilistic approach instead. At the outset, their designed protein wasn’t engineered to possess a singular structure that selectively binds to a certain type of metal. They created a flexible system that could arrange itself in multiple ways to bind different metal ions in different geometries. It was this flexibility that led them to an outcome they did not originally plan for.

“In analyzing these systems, we saw that proteins were binding to cobalt and nickel ions ahead of copper, which is not the natural order of things,” stated Choi. “We created an hypothesis and tested new variants. After extensive analysis, we realized we could construct a protein environment where copper was disfavored.”

“This is an example of designing a pathway rather that a target,” explained Tezcan. “I personally think that this is a more exciting way to go about the protein design problem. By incorporating an element of flexibility into the design, we leave open the possibility of different outcomes and new design principles we couldn’t have known beforehand.”

Research on selective metal binding and protein design has importance beyond a better understanding of the fundamentals of life. It can also lay the foundation for more efficient processes during environmental remediation, such as when certain metals need to be sequestered in contaminated water. Protein design is also a critical part of pharmaceutical research and development.

“We were intrigued by the question ‘Can we design proteins that can selectively bind to metals or have catalytic reactions in ways that evolution has not yet invented?'” said Choi. “Just because biology doesn’t do it, it doesn’t mean it’s not possible.”

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Materials provided by University of California – San Diego. Original written by Michelle Franklin. Note: Content may be edited for style and length.

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Single test for over 50 genetic diseases will cut diagnosis from decades to days

A new DNA test, developed by researchers at the Garvan Institute of Medical Research in Sydney and collaborators from Australia, UK and Israel, has been shown to identify a range of hard-to-diagnose neurological and neuromuscular genetic diseases quicker and more-accurately than existing tests.

‘We correctly diagnosed all patients with conditions that were already known, including Huntington’s disease, fragile X syndrome, hereditary cerebellar ataxias, myotonic dystrophies, myoclonic epilepsies, motor neuron disease and more,’ says Dr Ira Deveson, Head of Genomics Technologies at the Garvan Institute and senior author of the study.

The diseases covered by the test belong to a class of over 50 diseases caused by unusually-long repetitive DNA sequences in a person’s genes — known as ‘Short Tandem Repeat (STR) expansion disorders’.

‘They are often difficult to diagnose due to the complex symptoms that patients present with, the challenging nature of these repetitive sequences, and limitations of existing genetic testing methods,’ says Dr Deveson.

The study, published today in Science Advances, shows that the test is accurate, and allows the team to begin validations to make the test available in pathology services around the world.

A patient who participated in the study, John, first realised something wrong when he experienced unusual problems balancing during a ski lesson.

‘It was very worrying having symptoms that, over the years, increased in severity; from being active and mobile to not being able to walk without support. I had test after test for over ten years and absolutely no answers as to what was wrong,’ says John, who was eventually diagnosed with a rare genetic disease called CANVAS, which affects the brain.

‘It was reassuring to finally confirm my diagnosis genetically, and it’s exciting to know that, in the near future, others with these types of conditions will be able to get a diagnosis quicker than I did,’ he says.

‘For patients like John, the new test will be a game-changer, helping to end what can often be a taxing diagnostic odyssey,’ says Dr Kishore Kumar, a co-author of the study and clinical neurologist at the Concord Hospital.

Repeat expansion disorders can be passed on through families, can be life threatening and generally involve muscle and nerve damage, as well as other complications throughout the body.

Quicker, more-accurate diagnosis for patients avoids ‘diagnostic odyssey’

Current genetic testing for expansion disorders can be ‘hit and miss’, says Dr Kumar. ‘When patients present with symptoms, it can be difficult to tell which of these 50-plus genetic expansions they might have, so their doctor must decide which genes to test for based on the person’s symptoms and family history. If that test comes back negative, the patient is left without answers. This testing can go on for years without finding the genes implicated in their disease. We call this the ‘diagnostic odyssey’, and it can be quite stressful for patients and their families,’ he says.

‘This new test will completely revolutionise how we diagnose these diseases, since we can now test for all the disorders at once with a single DNA test and give a clear genetic diagnosis, helping patients avoid years of unnecessary muscle or nerve biopsies for diseases they don’t have, or risky treatments that suppress their immune system,’ says Dr Kumar.

Although repeat expansion disorders cannot be cured, a quicker diagnosis can help doctors identify and treat disease complications earlier, such as heart issues associated with Friedreich’s ataxia.

Scanning for known and novel diseases

Using a single DNA sample, usually extracted from blood, the test works by scanning a patient’s genome using a technology called Nanopore sequencing.

‘We’ve programmed the Nanopore device to hone in on the roughly 40 genes known to be involved in these disorders and to read through the long, repeated DNA sequences that cause disease,’ he says. ‘By unravelling the two strands of DNA and reading the repeated letter sequences (combinations of A, T, G or C), we can scan for abnormally long repeats within the patient’s genes, which are the hallmarks of disease.’

‘In the one test, we can search for every known disease-causing repeat expansion sequence, and potentially discover novel sequences likely to be involved in diseases that have not yet been described,’ says Dr Deveson.

Upscaling to wider use in the next five years

The Nanopore technology used in the test is smaller and cheaper than standard tests, which the team hopes will smooth its uptake into pathology labs. ‘With Nanopore, the gene sequencing device has been reduced from the size of a fridge to the size of a stapler, and costs around $1000, compared with hundreds of thousands needed for mainstream DNA sequencing technologies’ says Dr Deveson.

The team expects to see their new technology used in diagnostic practice within the next two to five years. One of the key steps towards that goal is to gain appropriate clinical accreditation for the method.

Once accredited, the test will also transform research into genetic diseases, says Dr Gina Ravenscroft, a co-author of the study and a researcher working on rare disease genetics at the Harry Perkins Institute of Medical Research.

‘Adult-onset genetic disorders haven’t received as much research attention as those that appear in early life,’ she says. ‘By finding more people with these rare adult-onset diseases, and those who may be pre-symptomatic, we’ll be able to learn more about a whole range of rare diseases through cohort studies, which would otherwise be hard to do.’

The work was supported predominantly by philanthropic funding from The Kinghorn Foundation.

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Visualizing the invisible: New fluorescent DNA label reveals nanoscopic cancer features

Researchers have developed a new fluorescent label that gives a clearer picture of how DNA architecture is disrupted in cancer cells. The findings could improve cancer diagnoses for patients and classification of future cancer risk.

Published today in Science Advances, the study found that the DNA-binding dye performed well in processed clinical tissue samples and generated high-quality images via superresolution fluorescence microscopy.

“My lab is focused on developing microscopy techniques to visualize the invisible,” said senior author Yang Liu, Ph.D., associate professor of medicine and bioengineering at the University of Pittsburgh. “We are one of the first groups to explore the capabilities of superresolution microscopy in the clinical realm. Previously, we improved its throughput and robustness for analysis of clinical cancer samples. Now, we have a DNA dye that is easy to use, which solves another big problem in bringing this technology to patient care.”

Inside the cell’s nucleus, DNA strands are wound around proteins like beads on a string. Pathologists routinely use traditional light microscopes to visualize disruption to this DNA-protein complex, or chromatin, as a marker of cancer or precancerous lesions.

“Although we know that chromatin is changed at the molecular scale during cancer development, we haven’t been able to clearly see what those changes are. This has bothered me for more than 10 years,” said Liu, who is also a member of the UPMC Hillman Cancer Center. “To improve cancer diagnosis, we need tools to visualize nuclear structure at much greater resolution.”

In 2014, the Nobel Prize-winning invention of superresolution fluorescence microscopy was a major step towards making Liu’s vision reality. A molecule of interest is labelled with a special fluorescent dye that flashes on and off like a blinking star. Unlike traditional fluorescence microscopy, which uses labels that glow constantly, this approach involves switching on only a subset of the labels at each moment. When several images are overlayed, the complete picture can be reconstructed — at a much higher resolution than previously possible.

Until now, the problem was that fluorescent dyes didn’t work well on DNA or in processed clinical cancer samples. So, Liu and her team formulated a new label called Hoechst-Cy5 by combining the DNA-binding molecule Cy5 and a fluorescent dye called Hoechst with ideal blinking properties for superresolution microscopy.

After showing that the new label produced higher resolution images than other dyes, the researchers compared colorectal tissue from normal, precancerous and cancerous lesions. In normal cells, chromatin is densely packed, especially at the edges of the nucleus. Condensed DNA glows brightly because a higher density of labels emits a stronger signal, while loosely packed chromatin produces a dimmer signal.

The images show that as cancer progresses, chromatin becomes less densely packed, and the compact structure at the nuclear border is severely disrupted. While these findings indicate that the new label can distinguish normal tissue from precancerous and cancerous lesions, Liu said that superresolution microscopy is unlikely to replace traditional microscopes for such routine clinical diagnoses. Instead, this technology could shine in risk stratification.

“Early-stage lesions can have very different clinical outcomes,” said Liu. “Some people develop cancer very quickly, and others stay at the precursor stage for a long time. Stratifying cancer risk is a major challenge in cancer prevention.”

To see if chromatin structure could hold clues about future cancer risk, Liu and her team evaluated patients with Lynch syndrome, a heritable condition that increases the risk of several cancer types, including colon cancer. They looked at non-cancerous colorectal tissue from healthy people without Lynch syndrome and Lynch patients with or without a personal history of cancer.

The differences were striking. In Lynch patients who previously had colon cancer, chromatin was much less condensed than in healthy samples, suggesting that chromatin disruption could be an early sign of cancer development — even in tissue that looks completely normal to pathologists.

For Lynch patients without a personal history of cancer, some will go on to develop cancer, while others will not.

“We see a much larger spread in this group, which is very interesting,” said Liu. “Some patients resemble healthy controls, and some are closer to Lynch patients who previously had cancer. We think that patients with more open chromatin are those who are more likely to develop cancer. We need to follow these patients over time to measure outcomes, but we’re pretty excited that chromatin disruption in normal cells could potentially predict cancer risk.”

In future work, Liu and her team are interested in examining chromatin structure in endometrial tissue from Lynch patients, who also have elevated risk of endometrial cancer. The researchers also received funding recently to look at sputum samples from smokers for early detection of lung cancer.

Other authors who contributed to this study were Jianquan Xu, Ph.D., Xuejiao Sun, M.S., Hongqiang Ma, Ph.D., Rhonda M. Brand, Ph.D., Douglas Hartman, M.D., and Randall E. Brand, M.D., all of Pitt; and Mingfeng Bai, Ph.D., and Kwangho Kim, Ph.D., both of Vanderbilt University.

This work was funded by the National Institutes of Health (R01CA254112, R33CA225494 and R01CA232593).

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Making diversity, equity, inclusion integral part of physics education

While many physics instructors are beginning to incorporate lessons on diversity, equity, and inclusion (DEI) in the classroom, it can often feel like an add-on rather than an integral component of becoming a physicist.

In The Physics Teacher, by AIP Publishing, scientists from Carleton College and the University of Colorado Boulder are helping to change this narrative by presenting discussions and activities on DEI as a fundamental and essential part of physics training beyond the introductory physics level.

“Diversity, equity, and inclusion are a part of being a physicist, just as much as knowing about quantum mechanics or using an oscilloscope,” said author Martha-Elizabeth Baylor.

The team created two separate approaches for DEI curriculum at the intermediate level in 30-person and 75- to 120-person classrooms. The former replaced one question on a weekly homework assignment with a reflection essay on a topic important to physicists. The latter included activities and discussions during a two-day unit on representation.

“On the whole, students respond positively to covering this material in a physics class,” said author Jessica Hoehn. “They are eager for these conversations.”

The reflection essays in the first approach were a small component of a larger “Practicing Professionalism” framework, which explored what physicists know, do, and care about. Meanwhile, the second approach tested students on the ideas within their DEI activities and discussions, just as it would with other course content.

Baylor said students began the term by writing themselves out of the definition of a physicist. However, that changed by the end of the class.

“Many students come to see that the physics community thinks about the things that they think about, the things they care about,” said Baylor. “They find that anybody can be a physicist. They just have to care about physics, choose to do physics, and choose that as part of their identity.”

For women in these classes in particular, a large theme emerged: Their feelings about being in physics were particular to the cultural environment in the U.S.

The authors believe instructors can look at each curriculum and design their own lessons that they are comfortable enacting. The individual reflection activities in the first approach may be an easier start for instructors who want to engage with students on an individual basis, rather than lead a class discussion.

The researchers recommend looking at their resources for ideas, then gathering feedback and iteratively improving the curriculum. They hope to help other instructors frame physics as a human endeavor.

“We’re doing this, because if you enter the physics community, you need to be able to engage intelligently and respectfully in these conversations,” said Baylor.

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