Culture

The battle against antibiotic-resistant bacteria: A new study at Tel Aviv University revealed a mechanism through which "good" viruses can attack the systems of "bad" bacteria, destroy them and block their reproduction. The researchers demonstrated that the "good" virus (bacteriophage) is able to block the replication mechanism of the bacteria's DNA without damaging its own, and note that the ability to distinguish between oneself and others is crucial in nature. They explain that their discovery reveals one more fascinating aspect of the mutual relations between bacteria and bacteriophages and may lead to a better understanding of bacterial mechanisms for evading bacteriophages, as well as ways for using bacteriophages to combat bacteria.

The study, published recently in PNAS - Proceedings of the National Academy of Sciences, was led by Prof. Udi Qimron, Dr. Dor Salomon, Dr. Tridib Mahata and Shahar Molshanski-Mor of the Sackler Faculty of Medicine. Other participants included Prof. Tal Pupko, Head of the Shmunis School of Biomedicine and Cancer Research and also of the new AI and Data Science Center ; Dr. Oren Avram of the George S. Wise Faculty of Life Sciences; and Dr. Ido Yosef, Dr. Moran Goren, Dr. Miriam Kohen-Manor and Dr. Biswanath Jana of the Sackler Faculty of Medicine.

Prof. Qimron explains that the antibiotic resistance of bacteria is one of the greatest challenges faced by scientists today. One potential solution may lie in further investigation of the targeted eradication of bacteria by "good" bacteriophages; namely, understanding bacteriophage mechanisms for taking over bacteria as a basis for the development of new tools to combat bacterial pathogens.

With this intention in mind, the current study unveiled the mechanism by which the bacteriophage takes control of the bacteria. The researchers found that a bacteriophage protein uses a DNA-repair protein in the bacteria to "cunningly" cut the bacteria's DNA as it is being repaired. Since the bacteriophage's own DNA has no need for this specific repair protein, it is protected from this nicking procedure. In this way the "good" bacteriophage does three important things: it distinguishes between its own DNA and that of the bacteria, destroys the bacteria's genetic material, and blocks the bacteria's propagation and cell division.

Prof. Qimron adds: "The bacteriophage takes advantage of the bacterial DNA's need for repair, while the bacteriophage itself has no need for this specific kind of repair. In this way the bacteriophage destroys the bacteria without suffering any damage to itself. The ability to distinguish between oneself and others is of enormous importance in nature and in various biological applications. Thus, for example, all antibiotic mechanisms identify and neutralize bacteria only, with minimal effect on human cells. Another example is our immune system, which is geared toward maximum damage to foreign factors, with minimal self-injury."

The researchers discovered the process by searching for types of bacterial variants not impacted by this bacteriophage mechanism - those that have developed "immunity" to it. This inquiry led them to the specific bacterial mechanisms affected by the bacteriophage takeover. "We found that the 'immune' bacterial variants simply stopped repairing their DNA in ways that are vulnerable to the bacteriophage attack, thereby evading the bacteriophage's destructive mechanism. Shedding more light on the ways in which bacteriophages attack bacteria, our findings may serve as a tool in the endless battle against antibiotic-resistant bacteria," concludes Prof. Qimron.

Wider clean chemistry applications of the extraordinary Vortex Fluidic Device - invented by Flinders University's Professor Colin Raston - are likely in the wake of new research that has been published outlining the seemingly endless possible uses.

The defining paper on understanding fluid flow in the Vortex Fluidic Device has just been comprehensively explained in an article published in Nanoscale Advances (DOI: 10.1039/D1NA00195G).

This took more than 100,000 experiments to work out - and Professor Raston hopes this publication will encourage more researchers to embrace the VFD and explore yet more innovative applications for this ingenious device.

"How fluid flows is one of the grand challenges of science," says Professor Raston. "What we have been doing with the VFD provides answers for liquids subjected to mechanical energy."

Since 2013, Professor Raston has been working with his team to explore the possibilities of the VFD, which is capable of controlling chemical reactivity, materials processing and probing the structure of self-organised systems, enabling rapid and now predictable modifications.

The VFD has shown its capability in the synthesis of esters, amides, ureas, imines, alpha-amino phosphates, beta-Keto esters, modified amino acids and the local anaesthetic, lidocaine.

Professor Raston says the high-tech, yet simple device can be used in medical and pharmaceutical research, food processing, materials processing and more, aligned with a range of industries - all with a focus on cleaner, greener and cheaper production - and he hopes that the new conclusive summaries about the VFD experiments will see it embraced by more research organisations around the world, and be taken up by industry.

"The topological fluid flows, which were established as 'spinning top' flow, double helical flow and specular flow, account for all the processing outcomes and applications of the VFD - this is an exciting discovery," says Professor Raston.

"We have established the topological features of high shear fluid flow in the vortex fluidic device at sub-micron dimensions, at a critical tilt angle of 45 degrees, being the optimal angle for myriad applications of the device."

The proposed flow patterns in the VFD provide insights that allow accurate prediction and control the formation of nanostructures in the VFD and chemical reactions. The flow patterns also provide an understanding of the advantages of VFD processing relative to using other methods, showing the VFD processing to be without precedent.

As the latest example of green chemistry innovation, PhD candidate Matt Jellicoe has led research into using the VFD to control the coating of particles without using other waste generating reagents.

The paper - High shear spheroidal topological fluid flow induced coating of polystyrene beads with C60 spicules, by Matt Jellicoe, Kasturi Vimalanathan, Jason Gascooke, Xuan Luo and Colin Raston, has been published by Royal Society of Chemistry's ChemComm (10.1039/d0cc07165j).

"I believe the outcome of this research to be significant because we demonstrate the coating of particles 2-6 microns in diameter with zero waste and up to 98% efficiency. This could be beneficial towards the pharmaceutical companies which coat drugs with significant lower yield, thus leading to run off of dangerous chemicals into freshwater streams and the air," says Mr Jellicoe.

He expects the next stage of testing will investigate the possibility of using the VFD as a drug-coating device.

"This may significantly reduce the effects on the environment," says Mr Jellicoe, "and this is what excites me the most. The potential impact, especially on the environment and the economy, could be unfathomable."

A world-first international study led by the University of South Australia has identified a new drug to stop athletes developing dementia after sustaining repeated head injuries in their career.

The link between concussion and neurogenerative diseases is well established, but new research findings could halt the progression of chronic traumatic encephalopathy (CTE) in sportspeople who sustain repeated blows to the head.

CTE is a progressive and fatal brain disease associated with the accumulation of a protein known as hyperphosphorylated tau which affects cognition and behaviour.

In a paper published in Scientific Reports, UniSA Emeritus Professor Bob Vink and colleagues show how repeated concussions can cause CTE and a way to block it with a specially developed drug.

The findings will potentially have significant implications for athletes who play contact sports - such as boxers and footballers - as well as military veterans sustaining head injuries in conflict.

The team of researchers from Adelaide, Melbourne and the United States say the brain releases a neurotransmitter called substance P in the event of a head injury, causing abnormal amounts of the tau protein to collect inside neurons.

"Tau protein tangles are a feature of CTE, which reportedly leads to memory problems, confusion, personality changes, aggression, depression and suicidal thinking," Prof Vink says.

"Our research shows that by blocking substance P with a specific drug, we can prevent the tau protein tangles from developing in the brain and causing neurological problems."

The treatment was successfully tested in animal models, giving hope that CTE can be prevented in humans.

Prof Vink says the next step is human clinical trials, but that could take several years given that currently CTE can only be diagnosed post-mortem.

A study of 14,000 Americans over 25 years, published in Alzheimer's and Dementia in March, showed that people who sustained even one head injury were 25 per cent more likely to develop dementia later in life. This risk increased with multiple traumatic brain injuries.

The Guardian also reported in April that an analysis of late AFLW player Jacinta Barclay's brain uncovered neurological damage at age 29, highlighting the risks of repeated concussions to both sexes. Previous research has focused on the impact of brain injuries in male athletes, but females are more likely to sustain concussions.

Monash University researchers have provided a fundamental advance regarding how T cells become activated when encountering pathogens such as viruses.

The recent study published in Science, co-led by Professor Nicole La Gruta, Professor Jamie Rossjohn and Professor Stephanie Gras with first author Dr Pirooz Zareie from the Monash Biomedicine Discovery Institute, have found that T Cells need to recognise pathogens in a particular orientation in order to receive a strong activating signal.

T cells play a key role in the immune system by eliminating invading pathogens, such as viruses, and it is crucial to understand the factors that determine how and why T cells become activated after recognizing these pathogens.

T cells express on their surface a T cell receptor (TCR) that recognizes and binds to virus fragments (antigens) presented by infected cells. This recognition event can lead to T cell activation and killing of infected cells.

"The central issue is that there are millions of different T cell receptors (TCRs) in the human body, and a vast array of viruses, making it difficult to understand the rules around how T cell receptor recognition of a virus drives T cell activation. Indeed, it is a problem that has remained contentious for over 25 years" says Professor La Gruta.

"Our study has shown that the orientation in which the T cell receptor binds is a primary factor determining whether the T cell receives an activating signal," Professor La Gruta said.

"This is an advance in our fundamental understanding of how a T cell needs to 'see' pathogenic antigens in order to be activated," she said. "It has clarified a critical mechanism essential for effective T cell immunity. It is also relevant to the ongoing development of immunotherapies that aim to boost the activation of T cells."

Dr Pirooz Zareie stated: "a combination of technologies, including super-resolution microscopy, X-ray crystallography at the Australian Synchrotron, biochemical assays and using in vitro and in vivo experimental models from a variety of labs led to the findings."

The study represented a cross-disciplinary collaboration between researchers from the University of Utah, National University of Singapore, University of New South Wales and Monash University.

Niigata, Japan - A comprehensive investigation on cells and colony motion offers new insight into the proliferative and epithelial regenerative capacities of human primary oral keratinocyte cultures with implications for quality control of engineered cells used in regenerative medicine. Dr. Kenji Izumi and his colleagues, Dr. Emi Hoshikawa and Dr. Taisuke Sato, modified the optical flow (OF) protocol originally presented in their 2019 paper to add the capacity to determine the threshold of the cells/colony motion speed required to differentiate substandard oral keratinocyte populations before manufacturing a tissue-engineered oral mucosa tissue construct. Interdisciplinary collaboration was critical to the success of this study, with Dr. Izumi and Dr. Hoshikawa, both experts in the fields of oral keratinocyte biology, relying on the image analysis and mathematics expertise provided by Dr. Sato to enhance the protocol proceeding OF algorithm implementation. Oral mucosa keratinocytes are currently employed in regenerative dentistry and extra-oral regenerative medicine and distinguishing cellular health is critical for manufacturing high-quality products used in cell-based therapies. While previous studies have non-invasively characterized the optimal metabolic activities of oral mucosa tissue-engineered grafts, the non-invasive measurements for first passaged (p1) oral keratinocytes have not developed yet as a tool for quality control of cells. The researchers first determined the specific spatio-temporal growth pattern of p1 cells, allowing them to set correlative estimates that reduced the time of microphotography from 24 hours to 4 hours, resulting in fewer image analyses. Cells/colony proliferation and motion speed of each frame was then assessed by applying the OF algorithm with image segmentation. As noted by Dr. Izumi "dynamic image-based analysis, rather than static image analysis such as observation of colony shape, allowed us to focus on cells/colony motion of oral keratinocytes in our cell culture system in which cells do not form densely-packed colonies". Using this approach, the mean motion speed (MMS), a marker of locomotive ability, was evaluated. As expected, this analysis validated their prior finding that the MMS of oral keratinocytes is positively correlated with proliferative capacity. Surprisingly, the team found this was not the only cellular characteristic associated with MMS, as histologic evaluation of cells showed epithelial regenerative potential is correlated with motion speed. The ability to assess both the proliferative capacity and epithelial regenerative capacity of mid-phase oral keratinocytes using the MMS threshold make this a more robust and predictive quality screening tool to ensure that the cells are suitable for clinical application.

Taking their investigation one step further, the researchers compared the growth characteristics of p1 oral keratinocytes exposed to metabolic challenge with those under standard conditions: "The creative point in this study was that we coerced cells in culture under a couple of poor conditions, which we called "challenged" protocols, to debilitate cells," said Dr. Izumi. "Then, we extrapolated the "threshold" in our own culture condition." The proliferative potential of cells grown in differing conditions was compared, and the population doubling times was calculated to determine the MMS threshold indicative of cells suitable for transfer to 3D culture conditions. In their specific culture system, a motion index less than 40 μm/h reflected cellular damages induced by metabolic challenges and subpar cell colonies. However, these results have a wider application, with the motion index functioning as a threshold to determine the quality of cultured cells in different culture conditions, as observed by Dr. Izumi: "Depending on different type of cells, the details of the algorithm need to be considered and adjusted. More importantly, the "threshold" is necessary to be determined by different type of cells, culture media, and culture conditions." Given that the motion index is correlated with characteristics intimately connected to cell quality and clinical use, such as proliferation and epithelial regeneration, it can function as a reliable indicator of quality control. "Since the non-invasive and quantitative monitoring of cells allows multiple observations over time, it is useful for quality control of cells in regenerative medicine and contributes to cell-manufacturing industry." However, Dr. Izumi notes it has applications beyond even regenerative medicine, such as cancer research. Ultimately, the team hopes to increase the accuracy of the motion speed measurement in the future and elucidate the molecular relationship underlying the correlation between locomotion and proliferation of oral keratinocytes, which contributes to determining critical quality attributes of oral keratinocytes.

Carried like stowaways in the guts of international travelers, new and potentially deadly strains of antimicrobial resistant superbugs may be coming to a community near you, suggests new research from Washington University School of Medicine in St. Louis.

"Even before the COVID-19 pandemic, we knew that international travel was contributing to the rapid global increase and spread of antimicrobial resistance," said Alaric D'Souza, an MD/PhD student at Washington University and a co-first author of the study to be published June 6 in Genome Medicine. "But what's new here is that we've found numerous completely novel genes associated with antimicrobial resistance that suggest a worrisome problem on the horizon."

The research confirms that international travelers often return home with an unexpected bounty of new bacterial strains jostling for position among the thousands that normally reside within the gut microbiome.

Poverty, poor sanitation and changing agricultural practices have turned many low-income, developing regions into hot spots for diseases spread by bacteria, including infections that are increasingly resistant to a range of antibiotic drug treatments.

High-population densities make it easy for these bacteria to be shared among community residents and travelers through exposure to contaminated drinking water and food, or poorly sanitized restrooms, restaurants, hotel rooms and public transportation. Back at home, travelers run the risk of transferring these novel bacteria to family, friends and other community residents.

The research, conducted with Maastricht University in the Netherlands, involved analyzing bacterial communities in the gut microbiomes of 190 Dutch adults before and after travel to one of four international regions where the prevalence of resistance genes is high: Southeastern Asia, South Asia, North Africa and Eastern Africa.

Fecal samples analyzed as part of the study were randomly selected from a larger, multicenter investigation of about 2,000 Dutch travelers, the majority of whom were tourists, known as the Carriage Of Multi-resistant Bacteria After Travel (COMBAT) study.

"We found significant travel-related increases in the acquisition of resistance genes, abundance and diversity encoded by bacteria that are endemic to the region visited," D'Souza said. "These findings provide strong support for international travel as a vector for the global spread of clinically important antimicrobial resistance genes and highlight the need for broader surveillance of antimicrobial resistant bacteria in the gut microbiomes of returning travelers."

The new study was designed by co-senior authors John Penders, a medical microbiologist at Maastricht University, and Gautam Dantas, PhD, a professor of pathology & immunology at Washington University. Manish Boolchandani, PhD, a member of the Dantas Lab during the research and a 2020 graduate of the university's doctoral program in Computational and Systems Biology, is also a first author on the paper.

The World Health Organization, the U.S. Centers for Disease Control and Prevention, and other agencies have described the rapid spread of antimicrobial resistance as one of the most serious public health threats now facing the world -- a looming medical catastrophe that could outweigh the chaos created by the COVID-19 pandemic.

"While previous studies have scanned travelers' stool samples for well-known antimicrobial resistant bacteria, we used a combination of whole metagenome shotgun sequencing and functional metagenomics to identify both known and novel genes that code for antimicrobial resistance," Dantas said.

More traditional genomic techniques look for distinctive genetic signatures of individual pathogens. But such tests can only find known pathogens, while metagenomic sequencing can identify all organisms present in a given sample: good bacteria, dangerous bacteria and even those that are completely new.

In all, the researchers detected 121 antimicrobial resistance genes across the gut microbiomes of the 190 Dutch travelers. More than 40% of these resistance genes (51 of them) were only discovered using the more sensitive metagenomics technique, suggesting that potentially dangerous genes are being missed by the more conventional approaches.

Equally concerning, the study's results confirmed that 56 unique antimicrobial resistance genes had become part of the travelers' gut microbiomes during their trips abroad, including several mobile, high-risk resistance genes, such as extended-spectrum β-lactamases (ESBL) and the plasmid-borne colistin resistance gene, mcr-1.

Resistance to beta-lactam antibiotics is emerging worldwide and confers broad resistance to treatment by penicillins and other important antibiotics.

The mcr-1 genes protect bacteria from another antimicrobial drug called colistin, which is the last-resort treatment for infections by multidrug-resistant gram-negative bacteria. If colistin resistance spreads to bacteria that are resistant to other antibiotics, those bacteria could cause truly untreatable infections, the CDC has warned.

Because metagenomic analysis allows researchers to study all the bacteria and genes in a collection of gut microbiome samples as one, large mixed community of organisms, it also provides opportunity to explore complex ecological interactions between these organisms.

While bacteria may slowly evolve resistance from repeated exposures to antibiotics over time, diverse bacterial communities also share antimicrobial resistance genes through a more rapid process known as horizontal transfer, usually via the exchange of mobile genetic elements that allow snippets of DNA to jump from one bacterium to another.

"Since genes that code for resistance to different classes of antibiotics are often located on the same mobile elements, a single horizontal exchange has the potential to convert bacteria previously susceptible to antibiotics into a multi-drug resistant organism," said Dantas.

Researchers also used metagenomic techniques to piece together important contextual information about resistance gene location and function.

"There was significant association of resistance genes with mobile genetic elements, a primary way that resistance genes spread among bacteria," D'Souza said. "Though our study was unable to demonstrate resistance genes are carried by pathogenic bacteria, it's clear that this is possible. Additionally, international travelers have the potential to introduce resistance genes into their own communities when they return home, and future studies directly addressing this possibility are a priority."

Added Dantas: "Identifying new antimicrobial resistant bacteria and genes could play an important role in slowing the global spread of resistance and guide potential treatments for related diseases. Our study lays the groundwork for those efforts by offering new insight into the genetic mechanisms that underlie the rapid acquisition and sharing of antimicrobial resistance genes across people's gut microbiomes during international travel."

In the present study, Dr. Hidetoshi Hayashi (Professor, Nagoya City University) and collaborators screened small-molecule compounds that suppress UPR, using Myanmar wild plant extracts library. The screening system to track X-box binding protein 1 (XBP1) splicing activity revealed that the ethanol extract of the Periploca calophylla stem inhibited the inositol-requiring enzyme 1 (IRE1)-XBP1 pathway. They isolated and identified periplocin as a potent inhibitor of the IRE1-XBP1 axis. Periplocin also suppressed other UPR axes, protein kinase R-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Examining the structure-activity relationship of periplocin revealed that cardiac glycosides, basically used for cardiac insufficiency therapy, also inhibited UPR. Moreover, periplocin suppressed the constitutive activation of XBP1 and exerted cytotoxic effects in the human multiple myeloma cell lines, AMO1 and RPMI8226. These results reveal a novel suppressive effect of periplocin or the other cardiac glycosides on UPR regulation, suggesting that these compounds will contribute to the understanding of the pathological or physiological importance of UPR signaling.

Researchers from the Hubrecht Institute in Utrecht (The Netherlands) and the Max Planck Institute for Molecular Biomedicine in Münster (Germany) used computer simulations to reveal in atomic detail how a short piece of DNA opens while it is tightly wrapped around the proteins that package our genome. These simulations provide unprecedented insights into the mechanisms that regulate gene expression. The results were published in PLOS Computational Biology on the 3rd of June, 2021.

Every cell in the body contains two meters of DNA. In order to fit all the DNA in the cell's small nucleus, the DNA is tightly packed in a structure known as chromatin. Chromatin is an array of identical smaller structures named nucleosomes. In a single nucleosome, DNA is wrapped around 8 proteins called histones. Chromatin is not uniformly compact across the genome. The tightness of the packaging is important in regulating which genes are expressed and therefore which proteins are produced by a cell.

Transitions from tightly to loosely packed DNA - from closed to open chromatin - are essential for cells to convert to another cell type. These cell conversions are hallmarks of development and disease, but are also often used in regenerative therapies. Understanding how such transitions occur may contribute to understanding diseases and optimizing therapeutical cell type conversions.

Computational nanoscope

One step in the opening of chromatin is the motion of DNA while wrapped in nucleosomes. Like all molecular structures in our cells, nucleosomes are dynamic. They move, twist, breathe, unwrap and wrap again. Visualizing these motions using experimental methods is often very challenging. One alternative is to use the so-called "computational nanoscope".

Researchers use the term computational nanoscope to refer to a set of computer simulation methods. These methods enable them to visualize the movements of molecules over time. Over the past years, the methods have become so accurate that researchers started referring to them as a computational nanoscope; observing the molecules moving on the computer is similar to observing them under a very high resolution nanoscope.

Nucleosomes breathing

Jan Huertas and Vlad Cojocaru, supported by Hans Schöler from the Max Planck Institute for Molecular Biomedicine (Münster, Germany), generated multiple real-time movies of the movements of nucleosomes, each covering one microsecond from the nucleosome lifetime. Using these movies, they monitored how the nucleosomes open and close in a motion known as nucleosome breathing.

In their new paper, published in PLOS Computational Biology, Huertas and Cojocaru describe what causes nucleosome breathing. First, they found that the order in which the building blocks of DNA are arranged - the DNA sequence - is important for nucleosome breathing. Second, the dynamics of histone tails are essential for this process. These histone tails are flexible regions in the histones that play a role in the regulation of gene expression. While the role of histone tails has been studied intensively, little is known about how they influence the motions of single nucleosomes. With their simulations, Huertas and Cojocaru described the relationship between histone tails and nucleosome breathing in atomic detail.

Histone modifications

"Being able to observe the breathing of nucleosomes in computer simulations is very challenging. The fact that we have now been able to visualize this represents a major step towards simulating the complete spectrum of nucleosome dynamics, from breathing to unwrapping. It also allows us to study how these motions are affected by modifications of the histones, which occur in different cells and regions of our DNA. Our simulations revealed that two histone tails are responsible for keeping the nucleosome closed. Only when these flexible tails moved away from particular regions of DNA, the nucleosome was able to open," says the research leader, Vlad Cojocaru.

Jan Huertas, first author in the publication and recent PhD-graduate, adds: "Active (open) and inactive (closed) chromatin contain different modifications of histone tails. The next step is to perform simulations with such modifications. The atomic resolution of the simulations would allow us to pinpoint how each modification affects nucleosomes and chromatin dynamics."

Towards understanding epigenetics

All three researchers are excited about the future of the use of atomistic computer simulations in understanding gene expression mechanisms in development and disease. "With the further increase of computational power available in the world, we will soon be able to simulate milliseconds of a nucleosome lifetime with all its atoms included. Furthermore, we will be able to routinely simulate multiple nucleosomes to study the effect of different modifications of histones on gene expression. This will give unprecedented insights into the mechanisms that regulate gene expression," Cojocaru concludes.

Oncotarget published "Characterization of the inflammatory microenvironment and hepatic macrophage subsets in experimental hepatocellular carcinoma models" which reported that HCC typically develops on a background of chronic inflammation and fibrosis with tumor associated macrophages playing an important role in chronic inflammation-induced HCC and progression.

However, the liver harbors unique macrophages, resident liver Kupffer cells and monocyte-derived macrophages, and their contribution to HCC and to the population of TAMs is incompletely known.

Here, the authors characterized the tumor microenvironment and the proportion and transcriptional profile of hepatic macrophages in two commonly used HCC mouse models.

A gradually increased expression of inflammatory, immune regulatory, fibrotic and cell proliferation pathways and markers was observed during diethylnitrosamine - and non-alcoholic steatohepatitis -induced HCC development.

These insights are useful to further unravel sequential pathogenic events during hepatocarcinogenesis and direct future development of new treatment strategies for HCC.

Dr. Lindsey Devisscher from The Ghent University said, "The incidence of hepatocellular carcinoma (HCC) is increasing worldwide, and HCC is amongst the leading causes of cancer death globally."

"The incidence of hepatocellular carcinoma (HCC) is increasing worldwide, and HCC is amongst the leading causes of cancer death globally."

HCC is considered a classic inflammation-related cancer, whereby inflammation drives carcinogenesis by inducing continuous cycles of tissue damage, necrosis with regeneration and subsequent fibrosis, cell dysplasia and ultimately HCC lesions.

The observations that there were at least 4 nodules with an average tumor growth rate of 150% from 16 to 20 weeks of age, no visible metastasis and preserved liver function suggested that HCC induced in this model is equivalent to more advanced stages B to C of the Barcelona Clinic Liver Cancer staging system for patients.

The liver tumor microenvironment consists of cancer cells surrounded by extracellular matrix elements and different stromal cells such as fibroblasts, endothelial cells and inflammatory cells which secrete a variety of growth factors, cytokines or matrix remodeling enzymes.

Indeed, they previously reported that in models of DEN- and NASH-induced HCC, Mo massively infiltrate the liver KCs, whereas KC are partially depleted during chronic liver injury, including end-stage HCC.

This study assessed the time-dependent characteristics of the inflammatory micro-environment in the two aforementioned HCC mouse models, with an emphasis on the differential transcriptional profile of liver M/Users/anxiolydiot/Desktop/press-formatting-html.html subsets and the sequential changes in phenotype during the progression of HCC.

The Devisscher Research Team concluded in their Oncotarget Research Output, "HCC is an inflammation driven tumor, in which hepatic macrophage populations play a central role. KCs, Mo and Mo-M/Users/anxiolydiot/Desktop/press-formatting-html.html have divergent phenotypes that change with disease progression and these cell populations contribute to the population of TAMs in HCC. The knowledge that KCs also express typical TAM markers further contributes to the understanding of hepatocarcinogenesis in two different frequently used experimental mouse HCC models."

A growing number of people use they/them pronouns to signal their gender identity, but for many people, use of "they" to refer to a single individual takes some getting used to.

Results of a recent University of North Carolina at Chapel Hill study showed the social trend of announcing preferred pronouns, which is often seen in email signatures, Twitter bios and Zoom settings, improves how pronouns are understood.

"Announcing one's pronouns matters, and explicitly saying that someone uses they/them pronouns increases the chance that others will successfully interpret the pronoun in this way in the future," said Jennifer Arnold, a UNC-Chapel Hill professor of psychology and neuroscience who led the study published in Psychonomic Bulletin & Review.

There is a psychology of language and Arnold studies the mental steps that underlie the way we process language.

Singular "they" has been around for centuries. But its frequency and range of uses is expanding to those who identify as non-binary, that is, those who do not exclusively identify as male or female. Using the pronouns that a person goes by is considered a sign of respect.

Still sometimes people can use the wrong pronoun without realizing it or meaning any harm.

For the recent study Arnold worked with undergraduate students Heather Mayo and Lisa Dong to test the impact of explicitly discussing pronouns. For example, saying "Alex uses they/them pronouns."

During experiments, 184 participants from the United States, United Kingdom and Australia read short stories such as "Alex went running with Liz. They fell down." Answers to "Who fell down?" indicated whether the participants interpreted they as Alex or Alex and Liz.

Singular responses were found more often when Alex was either the only person in the story or when Alex was mentioned first. When Alex was listed as second, the rate of assigning singular interpretations was very low, occurring about 20 percent of the time. It was especially hard to get without instruction about preferred pronouns.

The singular interpretation was stronger - in some experiments doubling the chance of getting pronouns right -- when participants heard explicit instructions that Alex uses they/them pronouns. However, participants in all experiments had the opportunity to learn this through observation and illustrations.

"We found that people adopted the singular interpretation more often when they had been explicitly told a person uses they/them pronouns in comparison with people who just figured it out from the context of a conversation," Arnold said.

(Geneva, 5 June 2021) Mass screening of school age children has led to significantly higher numbers of coeliac disease cases being diagnosed, according to a new study presented today at the 6th World Congress of Paediatric Gastroenterology, Hepatology and Nutrition.

Researchers in Italy found double the number of cases of the autoimmune disease - where the body produces antibodies to gluten, a protein found in wheat, barley, and rye - in school children compared to a similar study by the same group 25 years ago.

A new screening programme of 7,760 children aged from five to 11 in eight provinces of Italy found that the overall prevalence of coeliac disease was 1.6%, much higher than the approximate 1% of the global population thought to be currently affected by the condition. The children were screened with a finger-tip blood test for Human Leukocyte Antigens (HLA) gene mutations which predisposes a child to developing coeliac disease. If they tested positive the children were then checked for antibodies to gluten. Diagnosis was then confirmed using the ESPGHAN (European Society for Paediatric, Gastroenterology, Hepatology and Nutrition) criteria.

Lead author of the CELI SCREEN multi-centre trial,i Prof. Elena Lionetti, says the study showed that screening in childhood leads to more cases of coeliac disease being diagnosed than in standard care (where children are tested if they present with symptoms, or are screened because of a family history of the disease).

'Our study showed that prevalence of coeliac disease in schoolchildren has doubled over the past 25 years when compared to figures reported by our team in a similar school age group,' says Prof. Lionetti. 'Our sentiment is that there are more cases of coeliac disease than in the past, and that we could not discover them without a screening strategy.'

'At the moment 70% of coeliac disease patients are going undiagnosed and this study shows that significantly more could be identified, and at an earlier stage, if screening were carried out in childhood with non-invasive screening tests. Diagnosis and avoiding gluten could potentially prevent damage to the villi (finger-like projections that line the gut), which can lead to malabsorption of nutrients and long-term conditions such as growth problems, fatigue and osteoporosis (a fragile bone condition).'

'The study has shown that screening is an effective tool for diagnosing coeliac disease in children which could potentially help avoid a lot of unnecessary suffering from what can be a hard-to-detect condition.'

Commenting on the research, Tunde Koltai, who is Chair of AOECS (Association of European Coeliac Societies) and Patient Representative of the ESPGHAN Public Affairs Committee, added: 'This new study adds to the growing evidence base that the number of people in Europe with coeliac disease is rising, yet many still remain undiagnosed. It is essential that we adopt an effective screening strategy for coeliac disease across Europe to ensure children and the wider population are diagnosed as early as possible so that they can have the best possible quality of life'.

Coeliac disease is caused by the body producing antibodies to gluten, a protein found in wheat, barley, and rye and used to make foods including bread, pasta, biscuits, cake, and some breakfast cereals. The antibodies damage the gut lining causing symptoms such as bloating, pain, diarrhoea, anaemia, and other conditions connected to malabsorption of nutrients, including fatigue, anaemia, osteoporosis, and fertility problems. In infants and children, coeliac disease can cause abdominal pain, bloating, and vomiting, as well as lead to poor growth and delay puberty.

Coeliac disease is one of the most common lifelong conditions in European countries. Following a strict gluten-free diet is an effective treatment, causing symptoms to disappear and gut damage to gradually heal.

The melodic and diverse songs of birds frequently inspire pop songs and poems, and have been for centuries, all the way back to Shakespeare's "Romeo and Juliet" or "The Nightingale" by H.C. Andersen.

Despite our fascination with birdsong, we are only beginning to figure out how this complicated behavior is being produced and which extraordinary specializations enabled songbirds to develop the diverse sound scape we can listen to every morning.

Songbirds produce their beautiful songs using a special vocal organ unique to birds, the syrinx. It is surrounded by muscles that contract with superfast speed, two orders of magnitude faster than e.g. human leg muscles.

"We found that songbirds have incredible fine control of their song, including frequency control below one Hertz", says Iris Adam, lead author on the study and Assistant Professor at Department of Biology, University of Southern Denmark.

A motor unit is the fundamental contraction unit of muscle and consists of a motor neuron and the number of muscle fibers it connects to and activates. Combining tissue preparations to count muscle and nerve fibers and mathematical models the researchers could show that a large portion of the motor units must be very small and even as small as single muscle fiber.

"Motor units vary in size from several hundreds or thousands of muscle fibers in our leg muscles down to only 5-10 in the muscles controlling eye position and the muscles in the larynx", says Dr. Coen Elemans, senior author on the study and head of the Sound Communication and Behavior group at the University of Southern Denmark.

"In zebra finch song muscles our models predicted that 13-17% of the motor neurons innervates a single muscle fiber."

This was such an extraordinary claim that the researchers developed a new technique that can measure the activity of all muscle fibers within a small muscle.

"Our new method allowed us for the first time to activate single motor neurons and visualize and record the activity of all responding muscle fibers simultaneously.", Adam says.

"Like this we were able to show that the song muscles of zebra finches indeed contain motor units a s small as one muscle fiber.", Adam adds.

To be able to understand what the effect such small motor units can have on song the researchers also measured the amount of stress the muscles can make and how such stress changes the frequency of the sound.

Adam: "Next to small motor units, we discovered that songbird vocal muscles have the lowest stress measured in any vertebrate."

"To be able to study how changes in muscle force alter the sound made by the birds' vocal organ, the syrinx, we had to invent a new setup" Elemans adds.

"This setup blows air through the syrinx while we can control the muscles with small motors".

Songbird vocal muscles certainly pack a lot of extremes. "They are among the fastest muscles known, and now we show that they are also the weakest with the highest level of control possible", says Adam.

This fine control is important. Previous research has shown that females can detect these small changes and use it to decide whether they are attracted to a male or not.

Songbirds evolved about 40 million years ago and quickly radiated into the speciose group of birds we know today. Song is crucial for females to find and judge males and can even drive speciation. A few important special features are thought to have been important for their success. Just as humans, songbirds need to learn their song from a tutor by imitation.

Adam: "We think that next to a special syrinx and their amazing ability to imitate sounds, the fine gradation of the song features such as pitch has increased the amount of different sounds a bird can make."

"We suggest that the fine graduation of sound has contributed to the radiated of songbirds", Elemans concludes.

link to Coen Elemans Lab at University of Southern Denmark: http://www.celemans.com/index.html

What The Study Did: This survey study in California assesses what the public knows about extreme risk protection orders and if people are willing to use them to prevent firearm-related harm, both in general and when a family member is at risk, and if not, why not. The orders temporarily suspend firearm and ammunition access by individuals a judge has deemed to be at substantial risk of harming themselves or others.

Authors: Nicole Kravitz-Wirtz, Ph.D., M.P.H., of the University of California Davis School of Medicine in Sacramento, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamahealthforum.2021.0975)

Editor's Note: The article includes funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Accurate soft tissue measurements are critical when making reconstructions of human ancestors, a new study from the University of Adelaide and Arizona State University has found.

"Reconstructing extinct members of the Hominidae, or hominids, including their facial soft tissue, has become increasingly popular with many approximations of their faces presented in museum exhibitions, popular science publications and at conference presentations worldwide," said lead author PhD student Ryan M. Campbell from the University of Adelaide.

"It is essential that accurate facial soft tissue thickness measurements are used when reconstructing the faces of hominids to reduce the variability exhibited in reconstructions of the same individuals."

Hominids have been readily accepted to line the halls of even the most trusted institutions. They are predominantly used for disseminating scientific information to the public in museum displays and students in university courses, which will influence the way humanity is perceived and defined more generally.

"Up until now soft tissue reconstruction has been based on mean tissue depth measurements which does not take into account variation in tissue depths between individuals," says Mr Campbell.

In this study, published in the journal PLOS ONE, the authors have formulated a facial soft tissue thickness dataset for adult chimpanzees, and a set of regression equations that can be used to reconstruct the soft tissues for ancient hominids, such as those dated from 4.0 to 1.2 million years ago.

The study was co-authored by Gabriel Vinas, a Master of Fine Arts candidate at Arizona State University who handles the sculpting in the lab.

"Correlations have been found and multiple regression models have been used to generate equations for improving estimations of soft tissue thickness from craniometrics in modern humans," he said.

"We looked at tissue depths in present day chimpanzees to identify correlations in skin and bone."

This article represents the first time that such a collection of tissue depth data has been collected and presented for chimpanzees in a systematic manner.

"The soft tissue thickness data for chimpanzees are freely available for anyone to download on Figshare.

"The equations, which resulted directly from this research, are also included and can be implemented in future practitioners' reconstructions," said Mr Campbell.

"This research is invaluable for future efforts reconstructing ancient hominids, as well as for comparative studies within and outside the discipline of biological/physical anthropology."

(SACRAMENTO, Calif.) -- Extreme risk protection orders, also known as gun violence restraining orders (GVROs) or "red flag" orders, exist in 19 states and the District of Columbia.

The laws allow law enforcement, family and household members, some co-workers, employers and teachers to work with a judge to temporarily remove access to firearms and ammunition from people at significant risk of self-harm or harming others.

But an obstacle to implementing these preventive measures has been revealed in a new study from the Violence Prevention Research Program at UC Davis Health. Although GVROs have been available in California for five years, two-thirds of the Californians surveyed for the study had never heard of them.

"Firearm violence is preventable, not inevitable. Raising public awareness about proactive ways for people to intervene can be crucial for preventing violence before it occurs," said Nicole Kravitz-Wirtz, lead author of the study and an assistant professor with the Violence Prevention Research Program.

GVROs are only available if an individual has or could get a gun, and other options to protect against harm have failed or are not appropriate.

The study appears June 4 in JAMA Health Forum.

Majority, including gun owners, would be somewhat or very willing to use a GVRO

The survey was completed in July 2020 by 2,870 adults statistically representative of the adult population in California. It also assessed personal willingness to use a GVRO when a family member was at risk.

After reading a brief description of California's GVRO law, more than 80% of the respondents said they would be somewhat or very willing to ask a judge to issue a GVRO if a family member had threatened to physically hurt themselves, someone else or a group of people.

Respondents who lived in homes with gun owners expressed the highest levels of willingness to ask a judge for a GVRO. The responses ranged from 84% who were somewhat or very willing if a family member were experiencing an emotional crisis to 95% if a family member had threatened to physically hurt someone else.

The study included five risk scenarios of a person who has or could get a gun and:

was experiencing an emotional crisis;

has severe dementia or similar condition;

has threatened to physically hurt themselves;

has threatened to physically hurt someone else; or

has threatened to physically hurt a group of people.

A majority of respondents who identified as gun owners -- 70% to 86%, depending on the described risk scenario -- said they would be somewhat or very willing to ask a judge for a GVRO if a family member had threatened to harm themselves or others.

About 30% of the respondents reported they were unwilling to ask a judge for a GVRO for a family member in at least one of the described risk scenarios. The most frequently cited reason for being unwilling was not knowing enough about GVROs. The second most common reason was the belief that the described risk scenarios are personal or family matters.

GVROs can be effective tools for preventing violence. They leverage the knowledge of those who are often the first to recognize someone they care about is in crisis or behaving dangerously and provide a tool for proactive intervention.

"Given the evidence of this and prior studies, the take-home message is clear: 'If you see or hear something, please say something,'" said Garen Wintemute, director of the UC Davis Violence Prevention Research Program and professor of emergency medicine at UC Davis Health.

Prevention measures gaining traction in United States

Firearms are involved in half of suicides and three-quarters of homicides in the United States, accounting for nearly 39,000 violent deaths in 2019, the most recent year in which data are available from the Centers for Disease Control and Prevention.

In California, as in many other states, GVRO legislation was passed in the wake of a public mass shooting. Past research suggests that GVROs have been used successfully to prevent mass harm and that these orders are particularly effective for suicide prevention. But the use of GVROs remains relatively uncommon.

In California, the use of GVROs has grown from 70 orders in 2016, the year the law went into effect, to 700 in 2019. However, overall uptake of the law has been slow, possibly due to a lack of awareness. Given high levels of personal willingness to use a GVRO, including among gun owners and non-owners who live with owners, the current study indicates that improved knowledge of GVROs may lead to increased usage to prevent firearm injury and death in California and other parts of the country.

"GVROs are promising tools for preventing firearm-related harm. Our findings are consistent with national studies indicating that many firearm violence prevention policies have widespread public support and that general consensus exists between firearm owners and non-owners," Kravitz-Wirtz says.