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LA JOLLA, Calif. and JUPITER, Fla.- MAY 29, 2020 - Surgery would be inconceivable without general anesthesia, so it may come as a surprise that despite its 175-year history of medical use, doctors and scientists have been unable to explain how anesthetics temporarily render patients unconscious.

A new study from Scripps Research published Thursday evening in the Proceedings of the National Academies of Sciences (PNAS) solves this longstanding medical mystery. Using modern nanoscale microscopic techniques, plus clever experiments in living cells and fruit flies, the scientists show how clusters of lipids in the cell membrane serve as a missing go-between in a two-part mechanism. Temporary exposure to anesthesia causes the lipid clusters to move from an ordered state, to a disordered one, and then back again, leading to a multitude of subsequent effects that ultimately cause changes in consciousness.

The discovery by chemist Richard Lerner, MD, and molecular biologist Scott Hansen, PhD, settles a century-old scientific debate, one that still simmers today: Do anesthetics act directly on cell-membrane gates called ion channels, or do they somehow act on the membrane to signal cell changes in a new and unexpected way? It has taken nearly five years of experiments, calls, debates and challenges to arrive at the conclusion that it's a two-step process that begins in the membrane, the duo say. The anesthetics perturb ordered lipid clusters within the cell membrane known as "lipid rafts" to initiate the signal.

"We think there is little doubt that this novel pathway is being used for other brain functions beyond consciousness, enabling us to now chip away at additional mysteries of the brain," Lerner says.

Lerner, a member of the National Academy of Sciences, is a former president of Scripps Research, and the founder of Scripps Research's Jupiter, Florida campus. Hansen is an associate professor, in his first posting, at that same campus.

The Ether Dome

Ether's ability to induce loss of consciousness was first demonstrated on a tumor patient at Massachusetts General Hospital in Boston in 1846, within a surgical theater that later became known as "the Ether Dome." So consequential was the procedure that it was captured in a famous painting, "First Operation Under Ether," by Robert C. Hinckley. By 1899, German pharmacologist Hans Horst Meyer, and then in 1901 British biologist Charles Ernest Overton, sagely concluded that lipid solubility dictated the potency of such anesthetics.

Hansen recalls turning to a Google search while drafting a grant submission to investigate further that historic question, thinking he couldn't be the only one convinced of membrane lipid rafts' role. To Hansen's delight, he found a figure from Lerner's 1997 PNAS paper, "A hypothesis about the endogenous analogue of general anesthesia," that proposed just such a mechanism. Hansen had long looked up to Lerner--literally. As a predoctoral student in San Diego, Hansen says he worked in a basement lab with a window that looked directly out at Lerner's parking space at Scripps Research.

"I contacted him, and I said, 'You are never going to believe this. Your 1997 figure was intuitively describing what I am seeing in our data right now,'" Hansen recalls. "It was brilliant."

For Lerner, it was an exciting moment as well.

"This is the granddaddy of medical mysteries," Lerner says. "When I was in medical school at Stanford, this was the one problem I wanted to solve. Anesthesia was of such practical importance I couldn't believe we didn't know how all of these anesthetics could cause people to lose consciousness."

Many other scientists, through a century of experimentation, had sought the same answers, but they lacked several key elements, Hansen says: First, microscopes able to visualize biological complexes smaller than the diffraction limits of light, and second, recent insights about the nature of cell membranes, and the complex organization and function of the rich variety of lipid complexes that comprise them.

"They had been looking in a whole sea of lipids, and the signal got washed out, they just didn't see it, in large part for a lack of technology," Hansen says.

From order to disorder

Using Nobel Prize-winning microscopic technology, specifically a microscope called dSTORM, short for "direct stochastical optical reconstruction microscopy," a post-doctoral researcher in the Hansen lab bathed cells in chloroform and watched something like the opening break shot of a game of billiards. Exposing the cells to chloroform strongly increased the diameter and area of cell membrane lipid clusters called GM1, Hansen explains.

What he was looking at was a shift in the GM1 cluster's organization, a shift from a tightly packed ball to a disrupted mess, Hansen says. As it grew disordered, GM1 spilled its contents, among them, an enzyme called phospholipase D2 (PLD2).

Tagging PLD2 with a fluorescent chemical, Hansen was able to watch via the dSTORM microscope as PLD2 moved like a billiard ball away from its GM1 home and over to a different, less-preferred lipid cluster called PIP2. This activated key molecules within PIP2 clusters, among them, TREK1 potassium ion channels and their lipid activator, phosphatidic acid (PA). The activation of TREK1 basically freezes neurons' ability to fire, and thus leads to loss of consciousness, Hansen says.

"The TREK1 potassium channels release potassium, and that hyper-polarizes the nerve--it makes it more difficult to fire--and just shuts it down," Hansen says.

Lerner insisted they validate the findings in a living animal model. The common fruit fly, drosophila melanogaster, provided that data. Deleting PLD expression in the flies rendered them resistant to the effects of sedation. In fact, they required double the exposure to the anesthetic to demonstrate the same response.

"All flies eventually lost consciousness, suggesting PLD helps set a threshold, but is not the only pathway controlling anesthetic sensitivity," they write.

Hansen and Lerner say the discoveries raise a host of tantalizing new possibilities that may explain other mysteries of the brain, including the molecular events that lead us to fall asleep.

Lerner's original 1997 hypothesis of the role of "lipid matrices" in signaling arose from his inquiries into the biochemistry of sleep, and his discovery of a soporific lipid he called oleamide. Hansen and Lerner's collaboration in this arena continues.

"We think this is fundamental and foundational, but there is a lot more work that needs to be done, and it needs to be done by a lot of people," Hansen says.
Lerner agrees.

"People will begin to study this for everything you can imagine: Sleep, consciousness, all those related disorders," he says. "Ether was a gift that helps us understand the problem of consciousness. It has shined a light on a heretofore unrecognized pathway that the brain has clearly evolved to control higher-order functions."

HOUSTON -- Patients with advanced non-small cell lung cancer (NSCLC) and the MET exon 14 (METex14) skipping mutation had a 46.5% objective response rate to the targeted therapy drug tepotinib, as shown in a study published today in the New England Journal of Medicine and presented at the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting ASCO20 Virtual Meeting (Abstract 9556 - Poster 322) by researchers from The University of Texas MD Anderson Cancer Center.

"The success of this trial, alongside other studies on the same class of drugs, establishes MET exon 14 as an actionable target for non-small cell lung cancer," said senior author Xiuning Le, M.D., Ph.D., assistant professor of Thoracic/Head & Neck Medical Oncology. "We're pleased to show that another group of lung cancer patients may benefit from precision medicine."

METex14 skipping is a mutation that drives cancer growth and occurs in 3-4% of all NSCLC patients. Patients with METex14 skipping tend to be older, with a median age of 74, and typically don't have other actionable mutations with existing targeted therapy options.

The study results represent cohort A of the single-arm, international Phase II VISION trial, which is ongoing with additional cohorts. More than 6,700 NSCLC patients were prescreened for MET alterations through liquid and/or tissue biopsy. A total of 152 patients with advanced NSCLC and METex14 skipping were treated with tepotinib. Patients with prior treatment and/or stable brain metastasis were allowed to participate in the trial. Participants were treated with 500mg daily oral tepotinib.

Meaningful benefit for an elderly population

The primary endpoint was objective response rate, defined as complete or partial response, according to the RECIST v1.1 criteria and confirmed by independent review. After nine months follow-up, the primary efficacy population of 99 patients had a 46.5% objective response rate and durable response of 11.1 months.

"The median duration of response of almost one year is very meaningful for this patient population," Le said. "It's important for these elderly patients to have another treatment option, other than traditional chemotherapy, in oral form that can improve their quality of life for a long duration."

Toxicities were manageable, with grade ? 3 treatment-related adverse events reported in 27.6% of patients. The most common side effect was peripheral edema. Eleven percent of patients discontinued treatment due to adverse events.

The study also collected patient-reported outcomes, which indicated an improvement in coughing and overall maintenance of quality of life.

Liquid biopsy for biomarker detection

The VISION study represents the largest METex14 skipping cohort to be identified prospectively through liquid biopsy, verifying that liquid biopsy is a reliable method to detect the mutation. The study also showed that liquid biopsy was a useful tool to identify response to the drug.

Matched liquid biopsy samples for baseline and on-treatment were available for 51 patients. Next-generation sequencing found 34 of those patients had a molecular response with a complete or deep reduction of the mutation, and radiographic response was confirmed in 68% of patients who had a molecular response.

"This study marked a major advance in that we now have a highly effective, oral therapy for a group of non-small lung cancer patients that previously did not have any targeted therapy options," said co-author John Heymach, M.D., Ph.D., chair of Thoracic-Head & Neck Medical Oncology. "We are proud to lead the field forward as we work to provide novel treatments to patients."

Tepotinib was granted breakthrough therapy designation by the U.S. Food and Drug Administration (FDA) in September 2019, based on early data from the VISION study. It was approved for use as the first oral targeted therapy for MET-positive NSCLC in Japan in March 2020.

A full list of co-authors and their disclosures are included in the paper. The research was supported by Merck KGaA, Darmstadt, Germany.

High-throughput analysis of blood plasma could aid in identification of diagnostic and prognostic biomarkers for amyotrophic lateral sclerosis (ALS), according to research from North Carolina State University. The work sheds further light on a pathway involved in disease progression and appears to rule out an environmental neurotoxin as playing a role in ALS.

ALS is a progressive neurodegenerative disease that causes deterioration of nerve cells in the brain and spinal cord. Currently, treatments are hampered by lack of definitive targets, a diagnostic process that often takes over a year to complete, and insufficient and subjective methods for monitoring progression.

"Early diagnosis is important, but we are in dire need of quantitative markers for monitoring progression and the efficacy of therapeutic intervention," says Michael Bereman, associate professor of biological sciences at NC State and corresponding author of a paper describing the work. "Since disruptions in metabolism are hallmark features of ALS, we wanted to investigate metabolite markers as an avenue for biomarker discovery."

Bereman, with colleagues from NC State and Australia's Macquarie University, took blood plasma samples for 134 ALS patients and 118 healthy individuals from the Macquarie University MND Biobank. They used chip-based capillary zone electrophoresis coupled to high resolution mass spectrometry to identify and analyze blood plasma metabolites in the samples. This method quickly breaks the plasma down into its molecular components, which are then identified by their mass. The researchers developed two computer algorithms: one to separate healthy and ALS samples and the other to predict disease progression.

The most significant metabolism markers were associated with muscle activity: elevated levels of creatine, which aids muscle movement, and decreased levels of creatinine and methylhistidine, which are byproducts of muscle activity and breakdown. Creatine was 49% elevated in ALS patients, while creatinine and methylhistindine decreased by 20% and 24%, respectively. Additionally, the ratio of creatine versus creatinine increased 370% in male, and 200% in female, ALS patients.

Through machine learning, the algorithms that they created were then able to both separate healthy participants from ALS patients and predict the progression of the disease. The models produced results for both sensitivity (ability to detect disease), and specificity (ability to detect individuals without disease). The disease detection model performed at 80% sensitivity and 78% specificity, and the progression model performed at 74% sensitivity and 87% specificity.

"Creatine deficiency alone does not seem to be a problem - our results confirm that the creatine kinase pathway of cellular energy production, known to be altered in ALS, is not working as well as it should," Bereman says.

"These results are strong evidence that a panel of plasma metabolites could be used both for diagnosis and as a way to monitor disease progression," says Gilles Guillemin, professor of neurosciences at Macquarie University and co-author of the paper. "Our next steps will be to examine these markers over time within the same patient."

Another goal of the work was to look for evidence of exposure to an environmental neurotoxin, Beta Methylamino-L-Alanine (BMAA), which is found in green and blue algae blooms. BMAA has been associated with ALS since the 1950s, but few studies have attempted to detect it in human ALS patients. The researchers did not detect BMAA in the blood of either healthy or ALS patients.

The addition of the monoclonal antibody therapy Trastuzumab to radiotherapy did not reach the protocol objective of a 36% reduction in the ipsilateral breast tumor recurrence rate for women with HER2-positive ductal carcinoma in situ (DCIS) on the NRG Oncology clinical trial NSABP B-43. The trial did find a statistically non-significant, modest (19%) reduction in the rate of recurrence among women that received trastuzumab, but this difference was not statistically significant. These results were recently exhibited during an oral presentation at the virtual Annual Meeting of the American Society for Clinical Oncology.

The Phase III NRG-NSABP B-43 trial accrued 2014 women and randomly assigned trial participants in a 1:1 fashion to receive either whole-breast radiotherapy alone or radiotherapy with two doses of trastuzumab following lumpectomy. The goal of the trial was to determine if the addition of trastuzumab can assist in preventing recurrence of ipsilateral breast cancer, ipsilateral skin cancer, ipsilateral DCIS, or ipsilateral breast tumor recurrence in women with DCIS. This hypothesis was developed in response to data from previous preclinical studies that suggested that trastuzumab can boost the effectiveness of radiotherapy.

Of the 2014 patients that were accrued to the trial, 1998 patients (99.2%) had follow up information available at the median follow up time point of 79.2 months. 2001 women had radiotherapy information; 98.2% of patients completed radiotherapy treatment on the radiotherapy alone treatment arm (RT) and 98.1% completed radiotherapy on the radiotherapy plus trastuzumab arm (RT+T). In the RT+T group, 94.3% patients completed both doses of trastuzumab therapy, while 2.5% had only one dose of the therapy. Another 3.2% did not start trastuzumab.

The NRG-NSABP B-43 protocol required that 163 in-breast tumor recurrence (IBTR) events be confirmed or that all patients be on study for at least five years to trigger a definitive analysis. Since less than 163 IBTR events were confirmed, analysis was performed because all patients were on the trial for five years or longer.

At this preliminary analysis based on information through December 31, 2019, 114 IBTR events were confirmed with 63 being in the RT arm and 51 in the RT+T treatment arm. In those that had a recurrence, 38 were invasive including 18 in the RT arm and 20 in the RT+T treatment arm. The remaining 76 IBTR events were DCIS with 45 in the RT treatment arm and 31 in the RT+T treatment arm. Annual IBTR event rates were 0.99% per year in the RT group and 0.80% per year in the RT+T group. There were 48 deaths on the trial with 26 in the RT arm and 22 in the RT+T arm.

"This is the first prospective, randomized study of HER2-targeted treatment for HER2-positive DCIS. It provides important insight into the natural history and impact of HER2-targeted treatment on outcomes," stated Melody Cobleigh, MD, of Rush University Medical Center and the lead author of the NRG-NSABP B-43 abstract.

ATLANTA--Paid sick leave (PSL) mandates like those found in the federal government's Families First Coronavirus Response Act may be helping to slow the spread of COVID-19, according to a new study by health economists at Georgia State and Tulane universities.

Since 2007, several state and local governments have enacted laws requiring employers to provide their workers with paid sick leave. Michael Pesko, an associate professor in Georgia State's Andrew Young School of Policy Studies, and co-author Kevin Callison studied the effects of these staggered mandate adoptions using multiple government-collected survey data sources from 2005 to 2018.

The mandates were effective in increasing the number of workers holding Paid Sick Leave coverage, particularly those in low-wage industries who were unlikely to have previously received PSL benefits from their employers, they found. Women and racial/ethnic minorities benefitted disproportionately from the PSL mandates.

"These mandates reduced the number of people attending work while sick, which is similar to an earlier study showing influenza-like disease rates decreased after employees gained access to paid sick leave," said Pesko. "If paid sick leave helps stop people from attending work while sick and prevents the spread of disease as a result, this has important policy implications in today's fight to contain COVID-19."

Paid Sick Leave reduces the rate of those working while sick by 4.5 percentage points on average for workers in industries with historically low rates of PSL, such as the accommodation and food service industries. PSL mandates are particularly likely to increase work absences among women and households with children, where workers may be using their benefits to care for a sick child or other family obligations.

"What are the policy implications? The Families First Coronavirus Response Act, which went into effect April 1, is the first congressionally passed bill that provides Paid Sick Leave for employees in medium- and small-sized businesses with coronavirus issues," Pesko said. "We believe that the bill will reduce people attending work with COVID-19 because it pays for them to stay home and recover. This bill is, therefore, an important component in COVID-19 containment efforts."

MINNEAPOLIS, MN- May 29, 2020 - According to the National Autism Association, people with autism spectrum disorder (ASD) may experience sensory hypersensitivity. A University of Minnesota Medical School researcher recently published an article in Nature Communications that illustrates why that may be true by showing the differences in visual motion perception in ASD are accompanied by weaker neural suppression in the visual cortex of the brain.

While experts in neuroscience and psychiatry recognize that differences in sensory functioning are common among people with ASD, it is not currently understood what is happening differently in the brain on a neural level to cause the variations in sensory perception.

Using functional MRI and visual tasks, lead author Michael-Paul Schallmo, PhD, assistant professor in the Department of Psychiatry at the U of M Medical School, and a team of researchers at the University of Washington found:

People with ASD show enhanced perception of large moving stimuli compared to neuro-typical individuals;

Brain responses to these visual stimuli are different among young adults with ASD compared to neuro-typical individuals. In particular, brain responses in visual cortex show less neural suppression in ASD;

A computational model can describe the difference in brain responses.

"Our work suggests that there may be differences in how people with ASD focus their attention on objects in the visual world that could explain the difference in neural responses we are seeing and may be linked to symptoms like sensory hypersensitivity," Schallmo said.

Schallmo is currently working with collaborators at the U of M on a follow-up study of visual and cognitive functioning in youth with ASD, Tourette syndrome, attention deficit hyperactivity disorder and obsessive-compulsive disorder. Having a better understanding of how these different disorders affect brain function could lead to new screenings to better identify kids who are at risk for ASD and related conditions. It may also help scientists to find new targets for studies seeking to improve treatments for sensory symptoms in these disorders.

BUFFALO, N.Y. -- Harm reduction strategies have proven effective for use of opioids, alcohol, and tobacco products. University at Buffalo and University of Michigan researchers say harm reduction techniques also have potential for cannabis users - but first, public health practitioners and organizations need to do a better job of making cannabis users aware of those strategies.

Researchers assessed harm reduction awareness by surveying nearly 500 participants at the 2019 Hash Bash, a popular marijuana advocacy event on the campus of the University of Michigan.

The research team has published a series of papers in recent years based on data collected by surveying Hash Bash attendees. Their latest study, published in Health Promotion Practice, shows that frequent cannabis users aren't as knowledgeable as they should be about harm reduction strategies, such as not driving within six hours of using cannabis. And that, the researchers argue, falls more squarely on public health's failure to properly provide that knowledge.

"Our findings should serve as a wake-up call to public health professionals to integrate harm reduction strategies into practice," said Jessica Kruger, PhD, the study's lead author and a clinical assistant professor of community health and health behavior in UB's School of Public Health and Health Professions.

"As more states legalize medicinal and recreational use of cannabis, it's important that public health equip people with proper knowledge about using cannabis. We know that abstinence just isn't realistic or desirable for some users. We can minimize the costs and risks of cannabis use by creating awareness around harm reduction strategies," Kruger added.

Fewer than half of the study participants believed that any of the listed strategies reduced the harm of using cannabis. Only 42% identified avoiding use when pregnant as an effective harm reduction strategy. Even less, 36%, identified avoiding driving within six hours of using cannabis as an effective strategy.

"This is really remarkable, given that both of these are common warnings for a variety of psychoactive and pharmaceutical substances," said co-author Daniel Kruger, PhD, a research associate professor of community health and health behavior in UB's School of Public Health and Health Professions. He is also a research investigator with the Population Studies Center at the University of Michigan.

About one-quarter of participants believed that using strains with high cannabidiol (CBD) CBD to tetrahydrocannabinol (THC) ratios, using a concentrate or dab without plant material, and putting ice in a bong to reduce cannabis potency were effective harm reduction techniques. Only using strains with a high CBD to THC ratio has been empirically supported, the researchers note.

Less than half of participants reported using any harm reduction strategy, and 39% reported using no effective strategy.

Although knowledge doesn't guarantee behavior or behavior change, the researchers note that providing cannabis users with accurate information on the risks and benefits of the drug will at least help users make informed decisions.

They point to two public health campaigns in Colorado, a state where cannabis is legal for adult use. That state's "Good to Know" campaign educated Colorado residents on new cannabis laws. The state's "Responsibility Grows Here" campaign shares information about the potential risks for teens and pregnant and breastfeeding women, and calls on users to consume cannabis responsibly.

"As more and more people have legal access to medical and recreational cannabis, the importance of effective cannabis-specific health education increases," said study co-author R. Lorraine Collins, PhD, associate dean for research in UB's School of Public Health and Health Professions and a professor of community health and health behavior.

Farmers in Bangladesh achieved significantly higher yields and revenues by growing insect-resistant, genetically engineered eggplant, a new Cornell study has found.

The four genetically engineered (Bt) varieties yielded, on average, 19.6% more eggplant - known as brinjal in Bangladesh - than non-Bt varieties and earned growers 21.7% higher revenue, according to the study, published May 25 in Frontiers in Bioengineering and Biotechnology.

The additional revenue per hectare (1 hectare is approximately 2 ½ acres) is the equivalent of around $664, a substantial sum for resource-poor farmers in Bangladesh.

The paper is the first to document the economic benefits of the four existing Bt brinjal varieties though the Bangladeshi market chain and their acceptability to farmers and consumers, said lead author Tony Shelton, professor of entomology and former director for the Feed the Future South Asia Eggplant Improvement Partnership based in Cornell's Department of Global Development. The study was based on a 2019 survey of Bt and non-Bt brinjal farmers.

Bt brinjal was developed by the Bangladesh Agricultural Research Institute (BARI) in conjunction with Mahyco (an India-based agricultural company), Cornell and the U.S. Agency for International Development, in an effort to stop the losses caused by eggplant fruit and shoot borer (EFSB) larvae caterpillars, and reduce pesticide use.

"The EFSB causes between 30% and 60% yield loss, even when insecticides are frequently sprayed," Shelton said. "Farmers typically apply insecticides more than 80 times during the four- to five-month brinjal growing season, a process that is both expensive and harmful to farmers, who spray without protective equipment."

Of Bt brinjal growers, 83% were satisfied with the yields obtained and 80% were satisfied with the quality of the plant; 59% of non-Bt brinjal growers were pleased with their yields. Some 28% of the non-Bt farmers also indicated that a large portion of their fruit was infested with EFSB larvae. This was not a concern for Bt brinjal, because it provides genetically inherent resistance.

"Bt brinjal varieties provide farmers a more sustainable crop that protects food security and the environment," said Maricelis Acevedo, director of the project since March 2020. "This study provides more evidence that Bt brinjal is being accepted in the market, but more work is needed to develop new varieties better adapted to local conditions and market preferences."

Because of the higher yields, increased revenue and fruit quality, about three-quarters of Bt brinjal farmers said they planned to grow the crop again next season. Brinjal is the second-most important vegetable grown in Bangladesh, cultivated by about 150,000 resource-poor farmers on 50,955 hectares, and consumed by the public on a daily basis.

The survey was conducted in the five most important brinjal producing districts in Bangladesh - Rangpur, Bogra, Rajshahi, Jessore and Tangail - through face-to-face interviews with 195 Bt farmers and 196 non-Bt farmers. Farmers made their own choices about which crop to grow.

A team of researchers led by Swansea University have developed new technology to monitor cholesterol in brain tissue which could uncover its relation to neurodegenerative disease and pave the way for the development of new treatments.

The research, published in the Proceedings of the National Academy of Sciences of the USA, shows the major locations of cholesterol in the brain and what molecules it can be converted to.

The brain is a remarkably complex organ, with cholesterol and its metabolites underpinning the brain's function. Dysregulated cholesterol metabolism is linked to a number of neurodegenerative disorders including Alzheimer's, Parkinson's, Huntington's disease, multiple sclerosis and motor neurone disease.

It is known that cholesterol is not evenly distributed across different brain regions; however, up until now there has been no technology available to map cholesterol metabolism in defined locations of the brain at microscopic levels, and to visualise how it changes in pathological niches in the brain.

Here, researchers describe an advanced mass spectrometry imaging platform to reveal spatial cholesterol metabolism in mouse brain at micrometre resolution from tissue slices. The researchers mapped not only cholesterol, but also biologically active metabolites arising from cholesterol turnover. For example, they found that 24S-hydroxycholesterol, the major cholesterol metabolite in the brain, is about ten times more abundant in striatum than in the cerebellum, two regions involved in different ways in voluntary movement and cognition.

The new technology comes from a decade of research at Swansea University where the team have worked out methods to reveal the different metabolites of cholesterol in very small quantities of the brain, as small as the tip of a ballpoint pen.

Professor William Griffiths, who co-led the study from Swansea University added: "Although our work was with a mouse, the technology can similarly be used in humans in a research lab or a clinical setting, and could have revolutionary value when linked to neurosurgery.

"Tissue excised during surgery could rapidly be profiled by our method in-clinic and used to distinguish healthy from diseased tissue, informing the surgeon on the next step of the operation."

Professor Yuqin Wang added: "This technology which precisely locates molecules in the brain will further our understanding of the complexity of brain function and how it changes in neurodegenerative disorders.

"Our results show that cholesterol turnover is particularly high in striatum, the area most affected in Huntington's disease. We will apply this method to find out how cholesterol metabolism is associated with this disease. This may lead to the development of new therapies to a disease which currently has no cure."

Plants produce the hormone jasmonic acid as a defence response when challenged. This is how they ensure that their predators no longer like the taste of their leaves. Biologists want to find out whether biological precursors and other variants of jasmonic acid lead to similar or different effects. But such derivatives of the hormone have so far been too expensive for experiments and difficult to come by. Researchers from the Faculties of Chemistry and Biology at Bielefeld University have now found a method that might make the production of a biologically significant precursor of jasmonic acid more efficient and cheaper. Their innovation: they imitate how plants produce the hormone. The result is 12-OPDA, a central precursor of jasmonic acid. In the long term, it could also be a potential precursor for high-quality perfume. The researchers present their method today (29.05.2020) in the research journal Advanced Science.

'Jasmonic acid can, for example, trigger the release of toxic substances such as nicotine in the leaves, which harms predators,' explains biologist Professor Dr Karl-Josef Dietz. 'Tobacco plants emit a modified form of jasmonic acid which induces neighbouring plants to prepare for attacks,' says Dietz. 'Jasmonic acid also supports healing and can stimulate damaged plants to regenerate.'

Dietz heads the Plant Biochemistry and Physiology Working Group at Bielefeld University. He is researching how plants react to stress and is working on changing and optimising their response. 'This will enable us to prepare plants for the new environmental conditions resulting from climate change, for instance.' If the warmer climate leads to an increase in beetle populations, plants could be equipped with the ability to harm these attackers with bitter substances. 'We are interested in the effect of preforms of jasmonic acid, such as 12-OPDA, which is only available in the milligram range and then costs several hundred euros,' says Dietz.

'The high price is due to the labour-intensive production process, as the production of 12-OPDA is extremely complex and involves numerous reaction steps in the classical chemical process,' says chemist Professor Dr Harald Gröger. He heads the Industrial Organic Chemistry and Biotechnology Working Group at Bielefeld University. Together with Dietz, he developed the idea of producing 12-OPDA (12-oxophytodienoic acid) as a precursor of jasmonic acid by means of an efficient and innovative synthetic method. Both scientists conduct research at the Center for Biotechnology (CeBiTec) at Bielefeld University.

The new method adopts the principle from plant cells: it uses enzymes as plant catalysts in a form optimised for synthetic purposes. 'It is important that these enzymes are used in the right ratio,' says Jana Löwe. She is the lead author of the new study and a researcher in Gröger's working group. The best part of the new method is that if all the initial conditions are correct, it subsequently runs on its own.

'Like plants, we use easily accessible linolenic acid in combination with only three enzyme reactions,' explains Löwe. Linolenic acid can be extracted from rapeseed oil, for example. The first enzyme incorporates oxygen from the air into the linolenic acid. The second enzyme subsequently produces a highly unstable intermediate, which is then converted into 12-OPDA by the third enzyme.

'It sounds simple,' says Gröger. 'The difficulty so far, however, has been the sensitive, short-lived intermediate stage created by the second enzyme. If the third enzyme is not added immediately, the resulting products are unusable.'

Löwe solves the problem by using bacteria as producers of the enzymes for the second and final stage of the reaction--in combination with a commercial enzyme derived from soybeans for the first reaction stage. The bacteria (Escherichia coli) have been genetically modified to provide the two enzymes in the required quantities. 'As soon as the unstable intermediate is formed, the required enzyme is immediately available and ensures the production of 12-OPDA,' says Löwe.

The 12-OPDA can then be used directly in biological studies or converted into other substances needed for Dietz's experiments, for example. Löwe has also developed a method for this. 'This provides us with a library of descendants of 12-OPDA for plant physiological investigations,' says Dietz. 'With further reactions, the 12-OPDA could even be used to produce methyl dihydrojasmonate efficiently in the future,' says Gröger. 'This is a substance required as an ingredient in many well-known perfumes.'

A combination of genetic shuffling and evolutionary selection of near-identical genetic sequences among specific bat and pangolin coronaviruses may have led to the evolution of SARS-CoV-2 and its introduction into humans, a new study suggests. The results also showed that the virus' entire receptor binding motif (RBM), a component that plays a key role in viral entry into host cells, was introduced through recombination with pangolin coronaviruses. The study joins ongoing efforts to identify the source of the virus that causes COVID-19, which is critical for informing efforts to establish proper animal models, discover new drugs and vaccines, and ultimately prevent the rise of future zoonotic diseases. While the precise origin of SARS-CoV-2 remains a mystery, this study makes clear "that reducing or eliminating direct human contact with wild animals is critical to preventing new coronavirus zoonoses in the future," the authors say. Proximity of different species in a wet market setting, for example, may increase the potential for cross-species spillover infections, by enabling recombination between more distant coronaviruses and the emergence of mutations, the authors say. By analyzing 43 complete genome sequences from three strains of SARS-CoV-2-like coronaviruses from bats and pangolins, Xiaojun Li and colleagues delineated which strains were most and least similar to the novel coronavirus, with a special focus on genes related to the virus' spike protein complex, a critical component that facilitates viral entry into host cells. They found evidence of strong evolutionary selection around the RBM - part of the spike's amino acid sequence that directly contacts host cell receptors - among the bat, pangolin, and human coronaviruses they studied. Amino acid sequences from these viruses and SARS-CoV-2 were identical or nearly identical in the regions adjacent to the RBM, suggesting that common evolutionary mechanisms shaped these distinct viral strains. The scientists also demonstrated that SARS-CoV-2's entire RBM was introduced through recombination with coronaviruses from pangolins. Together, evolutionary selection and frequent recombination among coronaviruses from bats, pangolins, and humans may have allowed the closely related viruses to readily jump between species, the authors postulate, leading to the introduction of SARS-CoV-2 in humans.

DURHAM, N.C. -- A team of scientists studying the origin of SARS-CoV-2, the virus that has caused the COVID-19 pandemic, found that it was especially well-suited to jump from animals to humans by shapeshifting as it gained the ability to infect human cells.

Conducting a genetic analysis, researchers from Duke University, Los Alamos National Laboratory, the University of Texas at El Paso and New York University confirmed that the closest relative of the virus was a coronavirus that infects bats. But that virus's ability to infect humans was gained through exchanging a critical gene fragment from a coronavirus that infects a scaly mammal called a pangolin, which made it possible for the virus to infect humans.

The researchers report that this jump from species-to-species was the result of the virus's ability to bind to host cells through alterations in its genetic material. By analogy, it is as if the virus retooled the key that enables it to unlock a host cell's door -- in this case a human cell. In the case of SARS-CoV-2, the "key" is a spike protein found on the surface of the virus. Coronaviruses use this protein to attach to cells and infect them.

"Very much like the original SARS that jumped from bats to civets, or MERS that went from bats to dromedary camels, and then to humans, the progenitor of this pandemic coronavirus underwent evolutionary changes in its genetic material that enabled it to eventually infect humans," said Feng Gao, M.D., professor of medicine in the Division of Infectious Diseases at Duke University School of Medicine and corresponding author of the study publishing online May 29 in the journal Science Advances.

Gao and colleagues said tracing the virus's evolutionary pathway will help deter future pandemics arising from the virus and possibly guide vaccine research.

The researchers found that typical pangolin coronaviruses are too different from SARS-CoV-2 for them to have directly caused the human pandemic.

However, they do contain a receptor-binding site -- a part of the spike protein necessary to bind to the cell membrane -- that is important for human infection. This binding site makes it possible to affix to a cell surface protein that is abundant on human respiratory and intestinal epithelial cells, endothelial cell and kidney cells, among others.

While the viral ancestor in the bat is the most closely related coronavirus to SARS-CoV-2, its binding site is very different, and on its own cannot efficiently infect human cells.

SARS-CoV-2 appears to be a hybrid between bat and pangolin viruses to obtain the "key" necessary receptor-binding site for human infection.

"There are regions of the virus with a very high degree of similarity of amino acid sequences among divergent coronaviruses that infect humans, bats and pangolins, suggesting that these viruses are under similar host selection and may have made the ancestor of SARS-CoV-2 able to readily jump from these animals to humans," said lead co-author Xiaojun Li from Duke.

"People had already looked at the coronavirus sequences sampled from pangolins that we discuss in our paper, however, the scientific community was still divided on whether they played a role in the evolution of SARS-CoV-2," said study co-lead author Elena Giorgi, staff scientist at Los Alamos National Laboratory.

"In our study, we demonstrated that indeed SARS-CoV-2 has a rich evolutionary history that included a reshuffling of genetic material between bat and pangolin coronavirus before it acquired its ability to jump to humans," Giorgi said.

RIVERSIDE, Calif. -- How might the novel coronavirus be prevented from entering a host cell in an effort to thwart infection? A team of biomedical scientists has made a discovery that points to a solution.

The scientists, led by Maurizio Pellecchia in the School of Medicine at the University of California, Riverside, report in the journal Molecules that two proteases -- enzymes that break down proteins -- located on the surface of host cells and responsible for processing viral entry could be inhibited. Such protease inhibition would prevent SARS-CoV2, the coronavirus responsible for COVID-19, from invading the host cell.

The research is featured as the cover story of the journal (Volume 25, Issue 10).

Spike glycoprotein

The outer surface of coronaviruses contains a critical protein called spike glycoprotein, or S-glycoprotein. Responsible for giving the coronavirus its typical crown shape, the S-glycoprotein is essential for the entry of viral particles into host cells. Host cell proteases, however, must first process or cut this viral surface protein to allow the virus to enter the cells.

Pellecchia's lab and others have recognized that in addition to a previously identified protease called TMPRSS2, the new SARS-CoV2 coronavirus could also be processed by an additional human protease, called furin, for viral entry.

"The use of the host protease furin for processing is a common mechanism of cell entry by both viral fusion proteins and certain bacterial toxins," said Pellecchia, a professor of biomedical sciences, who led the research team. "SARS-CoV2 uses this mechanism also. The nature of the 'proteolytic cleavage' in its S-glycoprotein can determine whether this virus can be transmitted across species, for example from bats or camels to humans."

A fusion protein combines the attributes of more than one protein. Proteolytic cleavage refers to the process of breaking the peptide bonds between amino acids in a protein, which results in cutting the protein.

The coronavirus S-glycoprotein contains three cleavage sites that human host proteases process. The exact nature and sequence of these cleavage sites, and their respective processing proteases, can determine the level of pathogenicity and whether the virus can cross species.

Spotlight on inhibitors

Pellecchia explained that the anthrax toxin, similar to SARS-CoV2, requires processing by human furin to infect macrophages, a type of white blood cell. Using anthrax toxin as model system, his team found an inhibitor of both TMPRSS2 and furin in cellular and animal models can efficiently suppress cell entry by the toxin.

A clinical trial with COVID-19 patients recently began using the TMPRSS2 inhibitor camostat.

"We found, however, that camostat is a poor furin inhibitor," Pellecchia said. "Our current study, therefore, calls for the development of additional protease inhibitors or inhibitor-cocktails that can simultaneously target both TMPRSS2 and furin and suppress SARS-CoV2 from entering the host cell."

Pellecchia added that until now the presence of a furin cleavage site in SARS-CoV2 had been linked to increased pathogenicity. But genetic elimination of furin in cellular laboratory studies failed to stop viral entry, suggesting TMPRSS2 remains the most relevant protease.

Using peptide sequences from SARS-CoV2 S-glycoprotein, however, his team has now demonstrated the new mutations in this coronavirus strain resulted in efficient and increased processing of viral entry by furin and TMPRSS2.

"In other words, SARS-CoV2, unlike other less pathogenic strains, can more efficiently use both proteases, TMPRSS2 and furin, to start the invasion of host cells," Pellecchia said. "While TMPRSS2 is more abundant in the lungs, furin is expressed in other organs, perhaps explaining why SARS-CoV2 is capable of invading and damaging multiple organs."

Pellecchia's lab has already identified potent and effective preclinical inhibitors of furin and demonstrated these inhibitors could be developed as potential COVID-19 therapeutics, perhaps in combination with drugs such as camostat, the TMPRSS2 inhibitor.

Funding sought

"We are seeking additional funding to pursue the design and development of dual inhibitors that can simultaneously target both TMPRSS2 and furin," Pellecchia said. "The funding would allow us to explore new possible effective therapeutics against COVID-19 and support studies that could have far reaching applications to ward off possible future pandemics resulting from similar activating mutations in other viral strains."

Pellecchia, who holds the Daniel Hays Chair in Cancer Research at the UCR School of Medicine, was joined in the research by Elisa Barile, Carlo Baggio, and Luca Gambini of UCR; and Sergey A. Shiryaev and Alex Y. Strongin of the Sanford Burnham Prebys Medical Discovery Institute in La Jolla.

In complex surgery, is there a correlation between the volume of services provided per hospital and the quality of treatment results? This is the question addressed in eight commissions on minimum volumes that the Federal Joint Committee (G-BA) awarded to the Institute for Quality and Efficiency in Health Care (IQWiG). The IQWiG report is now available for the sixth intervention to be tested, complex oesophageal surgery. According to the findings, there is a positive correlation between the volume of services and the quality of treatment results in complex oesophageal surgery: In hospitals with larger case volumes, the survival probabilities for patients who underwent surgery are higher overall. In addition, complications occur less frequently there.

High-risk procedures performed as elective surgery

Oesophageal operations, such as the complete or partial removal of the oesophagus or the reconstruction of the oesophageal passage that is then necessary, are considered high-risk procedures that are usually performed as elective surgery. In most cases (2015: 83%), malignant neoplasms are the reason for the procedure. In 2018, the German Federal Statistical Office registered about 4700 of these complex oesophageal operations. About 9.5% of the patients who underwent surgery between 2010 and 2015 died in hospital in connection with the procedure.

At present, a minimum of ten procedures per hospital location and year applies in Germany for complex oesophageal surgery.

Positive correlation between volume of services and survival probabilities

The IQWiG project team identified 37 studies investigating the correlation between the volume of services and the quality of treatment results in complex oesophageal surgery - 30 of these studies contain usable data.

The analysis of the data showed that the survival probabilities for patients who underwent oesophageal surgery are higher overall in hospitals with larger case volumes. This can be inferred from the studies for the outcome "all-cause mortality" as well as for the outcomes "surgery-related mortality" and "in-hospital mortality". Furthermore, in hospitals with larger case volumes, treatment-related complications such as tearing or leakage of the reconstructed tissue (anastomosis insufficiency) occur less frequently.

In relation to the volume of services per surgeon, the available data show that with increasing routine for oesophageal surgery, fewer patients die in hospital and treatment-related complications occur less frequently.

There are no meaningful studies examining the effects of specific minimum case volumes introduced into the health care system for complex oesophageal surgery on the quality of treatment results.

Due to the devastating worldwide impact of COVID-19, the illness caused by the SARS-CoV-2 virus, there has been unprecedented efforts by clinicians and researchers from around the world to quickly develop safe and effective treatments and vaccines. Given that COVID-19 is a complex new disease with no existing vaccine or specific treatment, much effort is being made to investigate the repurposing of approved and available drugs, as well as those under development.

In Frontiers in Immunology, a team of researchers from the U.S. Food and Drug Administration review all of the COVID-19 clinical and research findings to date. They provide a breakdown of key immunological factors underlying the clinical stages of COVID-19 illness that could potentially be targeted by existing therapeutic drugs.

Dr. Montserrat Puig of the U.S. Food and Drug Administration, senior author of the review, stated that "there are multiple factors involved in determining if the patient's immune response will be insufficient or successful in combating the infection. Our review is an overview of these factors and how they can be considered to define the context in which medications currently used for other diseases, or development of novel agents, can be utilized to prevent, ameliorate or cure COVID-19."

We know that during the early stage of COVID-19 people can show no symptoms or mild symptoms, and for many the disease resolves.

For others it can be catastrophic. The illness can progress to a severe stage with manifestations including Acute Respiratory Distress Syndrome, accompanied by severe lung inflammation and damage. Patients with severe COVID-19 are often admitted to intensive care units and require life support with medical ventilation.

This review compiles and summarizes published up-to-date studies unraveling the factors leading to the cytokine storm and its consequences observed in COVID-19, including the immunological events underlying the severe manifestation of the disease.

The analysis is further supplemented with knowledge previously acquired from other coronaviruses including SARS-CoV and MERS-CoV.

The authors underscore key immunological events that might tip the balance from a protective to a hyperinflammatory response leading to life-threatening conditions. They outline a promising list of currently available drugs that are either under study or under consideration for use in COVID-19 based on their potential to influence these key immunological events.

These drugs include those that could inhibit SARS-CoV-2 entry into host cells, antivirals with the potential to block SARS-CoV-2 replication or factors that could boost the antiviral response, monoclonal antibodies targeting pro-inflammatory cytokines that drive the hyperinflammatory response and therapeutics that could improve the function of the lungs.

Puig states that "approaches to therapy in the early stage of the disease will differ from those in its severe late stage." Adding that "as the results of clinical trials become available, it may become increasingly clear that there is likely no single magic bullet to resolve the disease but a combination of several interventions that target different key factors of COVID-19 may well be required."

Puig cautions that "the research and data obtained from COVID-19 studies are rapidly evolving and continuously updated. Thus, as clearly stated in our review, the information provided is a 'lessons learned' to date and describes the knowledge available at the time of the publication of the review."

The description of the immunological profile of the clinical stages of COVID-19 provided in this review will enable more informed decisions about the type and timing of treatments to be evaluated in clinical trials.

Puig explains that "our hope is that the information contained in our review will help professionals in COVID-19 research develop new tools and agents to better treat those at high risk of severe COVID-19."