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Melbourne researchers have revealed how melanoma cells are flooded with DNA changes as this skin cancer progresses from early, treatable stages through to fatal end-stage disease.

Using genomics, the team tracked DNA changes occurring in melanoma samples donated by patients as their disease progressed, right through to the time the patient died. This revealed dramatic and chaotic genetic changes that accumulated in the melanoma cells as the cancers progressed, providing clues to potential new approaches to treating this disease.

The research, published in Nature Communications, was led by Professor Mark Shackleton, Professor Director of Oncology at Alfred Health and Monash University; Professor Tony Papenfuss, who leads WEHI's Computational Biology Theme and co-heads the Computational Cancer Biology Program at Peter MacCallum Cancer Centre; and Dr Ismael Vergara, a computational biologist at WEHI, Peter Mac and the Melanoma Institute Australia.

At a glance

Genomics has been used to track DNA changes in melanoma samples donated by patients whose disease recurred and progressed after treatment.

The research revealed that end-stage melanomas acquired dramatic and chaotic genetic changes that are associated with aggressive disease growth and treatment resistance.

Understanding the genetic changes that drive melanoma growth and treatment resistance could lead to new approaches to treating this cancer.

Tracking a devastating cancer

Melanoma - the third most commonly diagnosed cancer in Australia - is caused by damaging changes occurring in the DNA of skin cells called melanocytes, usually as a result of exposure to ultraviolet (UV) radiation from sunlight. These genetic changes enable uncontrolled growth of the cells, forming a melanoma. As the melanoma cells keep dividing, some accumulate even more DNA changes, helping them to grow even faster and spread, said Professor Shackleton.

"At early stages, melanomas can be cured with surgery. However, they sometimes recur and progress to more aggressive forms. While there are excellent new therapies in these contexts, for some patients this progressing disease is difficult to treat," he said.

"We used DNA sequencing to document genetic changes that occurred as melanomas recurred and progressed in patients."

The team obtained genome sequencing data from tumours that had been donated by these patients and fed it into a mathematical model. This revealed that, as melanomas progress, they acquire increasingly dramatic genetic changes that add substantially to the initial DNA damage from UV radiation that caused the melanoma in the first place, said Professor Papenfuss.

"Early-stage primary melanomas showed changes in their DNA from UV damage - akin to mis-spelt words in a book. These changes were enough to allow the melanoma cells to grow uncontrollably in the skin," he said.

"In contrast, end-stage, highly aggressive melanomas, in addition to maintaining most of the original DNA damage, accumulated even more dramatic genetic changes. Every patient had melanoma cells in which the total amount of DNA had doubled - a very unusual phenomenon not seen in normal cells - but on top of that, large segments of DNA were rearranged or lost - like jumbled or missing pages in a book. We think this deluge of DNA changes 'supercharged' the genes that were driving the cancer, making the disease more aggressive.

"The genomes in the late-stage melanomas were completely chaotic. We think these mutations occur in a sudden, huge wave, distinct from to the gradual DNA changes that accumulate from UV exposure in form earlier-stage melanomas. The melanoma cells that acquire these chaotic changes seem to overwhelm the earlier, less-abnormal, slower growing cells," Professor Papenfuss said.

New insights into melanoma

Professor Shackleton said the research provided an in-depth explanation of how melanomas change as they grow and may also provide clues about how melanoma could be treated.

"We mapped sequential DNA changes to track the spread of the disease in individual cases, creating 'family trees' of melanoma cells that grew, spread and changed over time in each patient. In early-stage melanomas in the skin, the DNA changes were consistent with UV-damage, while the changes we saw in later-stage melanoma were totally wild, and associated with increased growth and spread of the disease, and evasion of the body's immune defences. We could also link some DNA changes to the development of treatment resistance," he said.

The research also revealed key cancer genes that may contribute to the growth and spread of the melanoma.

"Many patients' late-stage melanomas had damage to genes known to control cell growth and to protect the structure of DNA during cell growth and division. When these genes don't work properly, cell growth becomes uncontrolled and the DNA inside cells becomes even more abnormal - it's a snowball effect. The findings also suggest that therapies which exploit these damaging changes might be useful for treating late-stage melanoma," Professor Shackleton said.

The study included tumour samples from Peter Mac's Cancer tissue Collection After Death (CASCADE) program - in which patients volunteer to undergo a rapid autopsy following their death.

"Our whole team would like to extend our sincere gratitude to the patients and their families whose participation in CASCADE made this research possible. We hope that the insights we have gained will lead to better treatments for people with melanoma," Professor Shackleton said.

Clinically, multiple lines of evidence show that chronic pain and depressive symptoms are frequently encountered. Patients suffered from both pain and depression are likely to become insensitive to drug treatment, indicating a refractory disease. The neural mechanism under this comorbidity remains unclear.

In a study published in Nature Neuroscience, the research team led by Prof. ZHANG Zhi and Dr. LI Juan from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), reported the discrete thalamocortical circuits underlying the pain symptom caused by tissue injury and depression-like states.

Being the gateway towards cerebral cortex and considered as the major source of 'nociceptive neurons' at the highest level of the nervous system in anesthetized animals, the thalamus integrates physical signals of emotions and pains and projects them to the cortex through thalamocortical structure for differentiating and processing. Thus, the thalamocortical circuits for pain processing is a hot spot in research.

Taking advantage of mouse models of tissue-injury-associated allodynia as well as in vivo calcium imaging and multi-tetrode electrophysiological recordings, the researchers found an enhanced circuit from posterior thalamic nucleus (PO) to primary somatosensory cortex (S1) under tissue-injury conditions, .

Interestingly, for mice in depression-like states, who also displayed significant allodynia, regulation of the PO -> S1 circuit failed to take effect. What mediates the depression associated pain sensitization is another pathway from the parafascicular thalamic nucleus (PF) to anterior cingulate cortex (ACC).

These results provide a new insight into the pathogenesis of physical pain.

The novel understanding of the neural circuit may add to the precision of these targeting therapy strategies in clinical use as physical intervention of specific brain regions or neural circuits is the current treatment option toward drug-insensitive neurological diseases.

In a world first, a cross-institutional research collaboration has used a two-photon microscope (*1) with a combination of calcium imaging (*2) and holographic stimulation (*3) to reveal that the functional connectivity between neurons located in the primary somatosensory cortex is increased in response to acute pain.

Pain occurs as a result of injury, such as peripheral neuron damage or inflammation stemming from peripheral tissue violation. Research findings have been published on the involvement of central nervous system abnormalities in the onset of pain and sustained pain. The primary somatosensory cortex in the cerebral cortex plays an important role in identifying the strength and location of pain. Research carried out using fMRI and two-photon microscopy has shown that activity in this part of the brain is accelerated when acute pain is experienced. However, it has yet to be revealed how the functional connectivity and synchronization between neurons changes over time, and what kind of effect these alterations have on pain.

The researchers conducted experiments using inflammatory pain model mice and the results revealed that both the spontaneous activity of the neuronal population and the synchronized activity between neurons in the primary somatosensory cortex increased during acute pain. Furthermore, they discovered that when a single neuron was stimulated with holographic light, there was an increased response from the surrounding neurons. As the pain was ameliorated, the neurons gradually returned to their original state. The researchers also showed that expression levels in N-type calcium ion channels are involved in this mechanism, revealing that the pain threshold could be restored when inhibitors that blocked these channels were administered. It is hoped that these discoveries can contribute towards treatments for patients with chronic pain.

The research group included the following members:

Specially Appointed Assistant Professor OKADA Takuya and Professor MIZOBUCHI Satoshi, both of the Division of Anesthesiology, Kobe University Graduate School of Medicine.

Professor WAKE Hiroaki (Kobe University Organization for Advanced and Integrated Research) and Assistant Professor KATO Daisuke, both of the Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine.

Professor MATOBA Osamu (Kobe University Organization for Advanced and Integrated Research).

Professor TAKIGUCHI Tetsuya (Kobe University Graduate School of System Informatics).

These research findings will be published in Science Advances on March 19, 2021.

Main Points

The research group showed that when acute pain is experienced, there is an increase in both spontaneous activity and synchronized activity in neurons in the primary somatosensory cortex. Furthermore, when a single neuron was stimulated with holographic light, the response from the surrounding neurons also increased during this acute pain. The researchers also demonstrated that when the pain was ameliorated, the neurons returned to their original state.

The expression levels of N-type calcium ion channels in the primary somatosensory cortex were elevated during acute pain and the researchers revealed that this pain could be ameliorated by administrating channel inhibitors (either as an intraventricular injection, or as an ointment on the surface of the primary somatosensory cortex).

It is hoped that these results will contribute towards the development of treatments for patients suffering from chronic pain.

Research Background

Pain occurs as a result of injury, such as peripheral neuron damage or inflammation stemming from peripheral tissue violation. It is an unavoidable sensation that everyone has experienced, however the detailed mechanism for the onset and sustention of pain has yet to be illuminated. Vital research into pain has been conducted that focuses on the activation of neurons and glial cells in the dorsal horn of the spinal cord. With the development of imaging technologies, there has been increased research into the relationship between pain and regions of the brain in recent years.

The cerebral cortex's primary somatosensory cortex (S1) is an area of the brain that plays in important role in distinguishing pain. Research conducted using imaging technologies such as fMRI and two-photon microscopy have shown that the neuronal population in S1 is aggravated during acute pain, however the detailed, underlying neural networks in S1 that are involved in generating and sustaining pain have not been clarified.

The research team used a two-photon microscope to conduct calcium imaging to track identified neurons, illuminating increases in both spontaneous neuronal activity and synchronization between S1 neurons during acute pain. Furthermore, they revealed that when a single neuron was stimulated with holographic light, there was an increased response from the surrounding neurons and as the pain was ameliorated, the neurons gradually returned to their original state. In addition, the expression of N-Type calcium ion channels was found to play a role in this mechanism, and the researchers showed that when this expression was corrected, the pain threshold could be effectively restored.

Research Methodology and Findings

The researchers conducted calcium imaging using a two-photon microscope. This method enabled them to monitor the activity of neurons in a living brain. Inflammatory pain model mice were developed by injecting Complete Freund's Adjuvant (CFA) into the hind paws. During acute pain, the spontaneous activity of neurons in the 2/3 layer of S1 increases, as does the synchronization between neurons. The research group also showed that the neurons returned to their original state once pain was ameliorated. Moreover, they discovered that the higher the level of synchronization between neurons, the lower the pain threshold (Figure 1).

To verify the above results, an experiment was conducted using a combination of two-photon microscope calcium imaging and holographic stimulation. It was discovered that when a single S1 neuron in an inflammatory pain model mouse was stimulated, the response from the surrounding neurons increased during acute pain. Conversely, when pain was ameliorated, the response from the surrounding neurons decreased. In summary, it was shown that synchronization between neurons increased as a result of strengthened functional connectivity between neurons in S1 during acute pain, and that when this pain was ameliorated, this synchronization decreased.

In order to verify the relationship between the increased spontaneous activity of neurons in S1 2/3 layer and the threshold for pain, a modified human muscarinic receptor (hM3Dq) activated by clozapine-N-oxide (CNO) was used to artificially induce increased neuronal activity in the S1 of the mice. The researchers then compared the neuronal activity and pain threshold in the mice before and after CNO administration (using chemogenetics (*4)). These results showed that when S1 neuronal activity was artificially induced in mice, the synchronization between neurons increased while the pain threshold decreased.

Flow Cytometry (*5) was used to investigate the molecular mechanism relating to these results. The expression levels of each ion channel in the S1 neurons of inflammatory pain model mice that had experienced acute pain were compared with those of wild-type mice that had not been exposed to pain. The results showed that in the inflammatory pain model mice, there was increased expression in the N-type calcium channels, and that by administering calcium channel inhibitors (either as an intraventricular injection, or as an ointment on the surface of S1), the pain threshold could be restored.

Further Research

The primary somatosensory cortex (S1) is an area of the brain that plays in important role in distinguishing pain, and research up until now has shown that neuronal population activity in S1 is accelerated when acute pain is induced. The current research study revealed that not only was this activity accelerated in response to acute pain but that there is also an increase in functional connectivity and synchronized activity between the neurons.

Next, the research team is due to examine the causal relationship between neuronal activity and pain, using holographic stimulation. They will do this by first identifying and determining the features of the S1 neurons that play a large role in pain, and then applying holographic stimulation to the identified cells to investigate the causal relationship. Furthermore, the researchers plan to look into possible treatment options for acute pain, such as preventing the increase in functional connectivity between neurons.

PITTSBURGH, March 19, 2021 - Non-circulating memory T cells, whose main function is to provide local protection against re-infection, contribute to chronic transplant rejection, University of Pittsburgh School of Medicine researchers reveal in a paper published today in Science Immunology.

The scientists show that these "tissue-resident memory T cells" are harmful in situations where antigens that the cells recognize are present in the body for a long time, such as in cases of an organ or tissue transplant. This finding is an important step toward improving therapies to help prevent organ rejection in transplant recipients.

"Tissue-resident memory T cells serve an important surveillance function," said co-senior author Martin Oberbarnscheidt, M.D., Ph.D., assistant professor of surgery at Pitt. "If these cells encounter the same pathogen more than once, they can help quickly eliminate it. But studying these cells in transplants gives us a unique opportunity to look into what happens when the antigen persists--a new organ transplant is a big piece of tissue which, unlike an infection, stays in the body for a long time."

Immunologists and transplant surgeons have long been aware that T cells--a subset of immune cells central to the development of acquired immunity--play a critical role in acute rejection of a transplanted organ. But until now, the role of resident memory T cells in transplant rejection was overlooked.

"Resident memory T cells turn from being protective against an infection into a problem in a transplant setting as they fight off a life-saving organ," said lead author Khodor Abou-Daya, M.D., research assistant professor in Pitt's Department of Surgery. "It's an elephant in the room--T cells are present at a chronic stage of the kidney transplant rejection, but no one knew if these cells were functional."

Using a mouse model of kidney transplantation, the researchers showed that, over time, activated T cells that infiltrate a transplanted organ morph into resident memory T cells.

They discovered that if they surgically conjoin blood circulation of two mice, both of which received identical kidney transplants, memory T cells formed in transplanted organs don't travel from one mouse to the other. Similarly, if a transplanted kidney was then removed and re-transplanted again to yet another mouse, resident memory T cells stayed in the transplanted kidney and didn't disseminate anywhere else in the recipient's body, establishing that these cells reside in the tissue permanently.

It also is remarkable that, despite the presence of the ubiquitous antigen, these tissue-resident memory T cells didn't become "exhausted," as commonly happens to these T cells during chronic infections and in tumors. Instead, the cells remained functional, proliferating and producing signals that sustained a prolonged immune response. Moreover, their formation precipitated kidney graft rejection.

"There is an assumption that T cells in transplanted organs or tissues are exhausted and dysfunctional and may not contribute significantly to tissue rejection," said Abou-Daya. "Our work shows that tissue-resident memory T cells are functional and destructive."

Specifically targeting these cells could improve clinical transplant outcomes while preserving the immune system's ability to fight off infections, reducing the side effects of current systemic immunosuppressive therapies.

CAMBRIDGE, MA -- Many viruses infect their hosts through mucosal surfaces such as the lining of the respiratory tract. MIT researchers have now developed a vaccination strategy that can create an army of T cells that are ready and waiting at those surfaces, offering a quicker response to viral invaders.

The researchers showed that they could induce a strong memory T cell response in the lungs of mice by giving them a vaccine modified to bind to a protein naturally present in mucus. This can help ferry the vaccine across mucosal barriers, such as the lining of the lungs.

"In this paper, we specifically focused on T cell responses that would be useful against viruses or cancer, and our idea was to use this protein, albumin, as sort of a Trojan horse to get the vaccine across the mucosal barrier," says Darrell Irvine, the senior author of the study, who is the Underwood-Prescott Professor with appointments in the departments of Biological Engineering and Materials Science and Engineering; an associate director of MIT's Koch Institute for Integrative Cancer Research; and a member of the Ragon Institute of MGH, MIT, and Harvard.

In addition to protecting against pathogens that infect the lungs, these types of inhaled vaccines could also be used to treat cancer metastasizing to the lungs or even prevent cancer from developing in the first place, the researchers say.

Former MIT postdoc Kavya Rakhra is the lead author of the study, which appears today in Science Immunology. Other authors include technical associates Wuhbet Abraham and Na Li, postdoc Chensu Wang, former graduate student Kelly Moynihan PhD '17, and former research technicians Nathan Donahue and Alexis Baldeon.

Local response

Most vaccines are given as an injection into the muscle tissue. However, most viral infections occur at mucosal surfaces such as the lungs and upper respiratory tract, reproductive tract, or gastrointestinal tract. Creating a strong line of defense at those sites could help the body fend off infection more effectively, Irvine says.

"In some cases, vaccines given in muscle can elicit immunity at mucosal surfaces, but there is a general principle that if you vaccinate through the mucosal surface, you tend to elicit a stronger protection at that site," Irvine says. "Unfortunately, we don't have great technologies yet for mounting immune responses that specifically protect those mucosal surfaces."

There is an approved nasal vaccine for the flu, and an oral vaccine for typhoid, but both of those vaccines consist of live, attenuated viruses, which are better able to cross mucosal barriers. Irvine's lab wanted to pursue an alternative: peptide vaccines, which have a better safety profile and are easier to manufacture, but are more difficult to get across mucosal barriers.

To try to make peptide vaccines easier to deliver to the lungs, the researchers turned to an approach they first explored in a 2014 study. In that paper, Irvine and his colleagues found that attaching peptide vaccines to albumin proteins, found in the bloodstream, helped the peptides to accumulate in the lymph nodes, where they could activate a strong T cell response.

Those vaccines were given by injection, like most traditional vaccines. In their new study, the researchers investigated whether albumin could also help peptide vaccines get across mucosal barriers such as those surrounding the lungs. One of albumin's functions is to help maintain osmotic pressure in the lungs, and it can easily pass through the epithelial tissue surrounding the lungs.

To test this idea, the researchers attached an albumin-binding lipid tail to a peptide vaccine against the vaccinia virus. The vaccine also included a commonly used adjuvant called CpG, which helps to provoke a stronger immune response.

The vaccine was delivered intratracheally, which simulates inhalation exposure. The researchers found that this type of delivery generated a 25-fold increase in memory T cells in the mouse lungs, compared to injecting the albumin-modified vaccine into a muscle site far from the lungs. They also showed that when mice were exposed to the vaccinia virus months later, the intramuscular vaccine offered no protection, while all of the animals that received the vaccine intratracheally were protected.

Targeting tumors

The researchers also tested a mucosal vaccine against cancer. In that case, they used a peptide found on melanoma cells to immunize mice. When the vaccinated mice were exposed to metastatic melanoma cells, T cells in the lungs were able to eliminate them. The researchers also showed that the vaccine could help to shrink existing lung tumors.

This kind of local response could make it possible to develop vaccines that would prevent tumors from forming in specific organs, by targeting antigens commonly found on tumor cells.

"In both the virus and the tumor experiments, we're leveraging this idea that, as other people have shown, these memory T cells set up shop in the lungs and are waiting right there at the barrier. As soon as a tumor cell shows up, or as soon as a virus infects the target cell, the T cells can immediately clear it," Irvine says.

This strategy could also be useful for creating mucosal vaccines against other viruses such as HIV, influenza, or SAR-CoV-2, Irvine says. His lab is now using the same approach to create a vaccine that provokes a strong antibody response in the lungs, using SARS-CoV-2 as a target.

Nearly two-thirds of middle-aged and older adults in Canada report adverse childhood experiences

Hamilton, ON (Mar. 19, 20121) - New research from McMaster University has found that roughly three in every five Canadian adults aged 45 to 85 have been exposed to childhood abuse, neglect, intimate partner violence or other household adversity.

The research, which estimates the prevalence of a broad range of adverse childhood experiences, was published in CMAJ Open.

"Our research showed that adverse childhood experiences are highly prevalent in the Canadian population, with 62% of Canadian adults aged 45 to 85 reporting at least one exposure," said Divya Joshi, the study's lead author and a postdoctoral fellow in the Department of Health Research Methods, Evidence, and Impact at McMaster.

The study used data collected from 44,817 participants enrolled in the Canadian Longitudinal Study on Aging (CLSA), a large, national population-based study of health and aging. The participants completed questionnaires about adverse childhood experiences through telephone and face-to-face interviews between 2015 and 2018.

Childhood exposure to physical abuse, intimate partner violence and emotional abuse were the most prevalent types of adverse childhood experiences reported across all participants.

More than one in four adults reported exposure to physical abuse, and one in five reported exposure to intimate partner violence and emotional abuse in childhood.

The researchers also found that reporting of adverse childhood events varied by demographic factors, such as age, sex, socioeconomic status, education and sexual orientation.

People younger than 65 years, women, those with less education, lower annual household income, and those of non-heterosexual orientation reported greater exposure.
"We found that adverse childhood experiences were highly prevalent across all demographic groups, although some groups experienced an unequal or greater burden," Joshi said.

The research also showed that exposure to adverse childhood events varied across Canadian provinces.
"This research shows that strategies are needed to increase awareness of adverse childhood experiences and their long-lasting consequences," said Andrea Gonzalez, a member of the research team and an associate professor in the Department of Psychiatry and Behavioural Neurosciences at McMaster.

"We need to take measures to improve the quality of household environments, support positive parenting and promote healthy child development, as well as integrate trauma-informed care to prevent the negative consequences of adverse childhood experiences," added Gonzalez, who is a member of the Offord Centre for Child Studies and the McMaster Institute for Research on Aging.

Researchers at the Paul Scherrer Institute PSI have for the first time observed photochemical processes inside the smallest particles in the air. In doing so, they discovered that additional oxygen radicals that can be harmful to human health are formed in these aerosols under everyday conditions. They report on their results today in the journal Nature Communications.

It is well known that airborne particulate matter can pose a danger to human health. The particles, with a maximum diameter of ten micrometres, can penetrate deep into lung tissue and settle there. They contain reactive oxygen species (ROS), also called oxygen radicals, which can damage the cells of the lungs. The more particles there are floating in the air, the higher the risk. The particles get into the air from natural sources such as forests or volcanoes. But human activities, for example in factories and traffic, multiply the amount so that concentrations reach a critical level. The potential of particulate matter to bring oxygen radicals into the lungs, or to generate them there, has already been investigated for various sources. Now the PSI researchers have gained important new insights.

From previous research it is known that some ROS are formed in the human body when particulates dissolve in the surface fluid of the respiratory tract. Particulate matter usually contains chemical components, for instance metals such as copper and iron, as well as certain organic compounds. These exchange oxygen atoms with other molecules, and highly reactive compounds are created, such as hydrogen peroxide (H2O2), hydroxyl (HO), and hydroperoxyl (HO2), which cause so-called oxidative stress. For example, they attack the unsaturated fatty acids in the body, which then can no longer serve as building blocks for the cells. Physicians attribute pneumonia, asthma, and various other respiratory diseases to such processes. Even cancer could be triggered, since the ROS can also damage the genetic material DNA.

New insights thanks to a unique combination of devices

It has been known for some time that certain reactive oxygen species are already present in particulates in the atmosphere, and that they enter our body as so-called exogenous ROS by way of the air we breathe, without having to form there first. As it now turns out, scientists had not yet looked closely enough: "Previous studies have analysed the particulate matter with mass spectrometers to see what it consists of," explains Peter Aaron Alpert, first author of the new PSI study. "But that does not give you any information about the structure of the individual particles and what is going on inside them."

Alpert, in contrast, used the possibilities PSI offers to take a more precise look: "With the brilliant X-ray light from the Swiss Light Source SLS, we were able not only to view such particles individually with a resolution of less than one micrometre, but even to look into particles while reactions were taking place inside them." To do this, he also used a new type of cell developed at PSI, in which a wide variety of atmospheric environmental conditions can be simulated. It can precisely regulate temperature, humidity, and gas exposure, and has an ultraviolet LED light source that stands in for solar radiation. "In combination with high-resolution X-ray microscopy, this cell exists just one place in the world," says Alpert. The study therefore would only have been possible at PSI. He worked closely with the head of the Surface Chemistry Research Group at PSI, Markus Ammann. He also received support from researchers working with atmospheric chemists Ulrich Krieger and Thomas Peter at ETH Zurich, where additional experiments were carried out with suspended particles, as well as experts working with Hartmut Hermann from the Leibniz Institute for Tropospheric Research in Leipzig.

How dangerous compounds form

The researchers examined particles containing organic components and iron. The iron comes from natural sources such as desert dust and volcanic ash, but it is also contained in emissions from industry and traffic. The organic components likewise come from both natural and anthropogenic sources. In the atmosphere, these components combine to form iron complexes, which then react to so-called radicals when exposed to sunlight. These in turn bind all available oxygen and thus produce the ROS.

Normally, on a humid day, a large proportion of these ROS would diffuse from the particles into the air. In that case it no longer poses additional danger if we inhale the particles, which contain fewer ROS. On a dry day, however, these radicals accumulate inside the particles and consume all available oxygen there within seconds. And this is due to viscosity: Particulate matter can be solid like stone or liquid like water - but depending on the temperature and humidity, it can also be semi-fluid like syrup, dried chewing gum, or Swiss herbal throat drops. "This state of the particle, we found, ensures that radicals remain trapped in the particle," says Alpert. And no additional oxygen can get in from the outside.

It is especially alarming that the highest concentrations of ROS and radicals form through the interaction of iron and organic compounds under everyday weather conditions: with an average under 60 percent and temperatures around 20 degrees C., also typical conditions for indoor rooms. "It used to be thought that ROS only form in the air - if at all - when the fine dust particles contain comparatively rare compounds such as quinones," Alpert says. These are oxidised phenols that occur, for instance, in the pigments of plants and fungi. It has recently become clear that there are many other ROS sources in particulate matter. "As we have now determined, these known radical sources can be significantly reinforced under completely normal everyday conditions." Around every twentieth particle is organic and contains iron.

But that's not all: "The same photochemical reactions likely takes place also in other fine dust particles," says research group leader Markus Ammann. "We even suspect that almost all suspended particles in the air form additional radicals in this way," Alpert adds. "If this is confirmed in further studies, we urgently need to adapt our models and critical values with regard to air quality. We may have found an additional factor here to help explain why so many people develop respiratory diseases or cancer without any specific cause."

At least the ROS have one positive side - especially during the Covid-19 pandemic - as the study also suggests: They also attack bacteria, viruses, and other pathogens that are present in aerosols and render them harmless. This connection might explain why the SARS-CoV-2 virus has the shortest survival time in air at room temperature and medium humidity.

Sabrina L. Spencer, PhD, is a CU Boulder researcher and a CU Cancer Center member. Spencer recently won two awards: the Damon Runyon-Rachleff Innovation Award (from the Damon Runyon Cancer Research Foundation) and the Emerging Leader Award (from The Mark Foundation for Cancer Research). The preliminary research she used to apply for the grants, "Melanoma subpopulations that rapidly escape MAPK pathway inhibition incur DNA damage and rely on stress signalling," was published in Nature Communications on March 19, 2021. We spoke to Spencer about the awards and how she plans to use them to further her research.

Q: What is the focus of your research?

The work is about understanding where drug resistance comes from in cancer. It's a well-known problem, and it's particularly prominent with targeted therapeutics. These drugs usually work great at first, but then, after some time, there's relapse.

A lot of people have focused on trying to understand what mutations in those relapsed tumors make the drugs stop working. But in a way, that's a little too late. Because the question is, how did those cells survive in the first place to be able to acquire the mutations to become drug resistant? We wanted to look at the first few days of drug treatment to understand whether you can already see cells adapting in a non-genetic way in order to evade the drugs.

Q: You're watching cells become drug resistant in real time? How does that work?

We use time-lapse microscopy to study this process. We're particularly adept at time-lapse imaging of single cells, where we film single cancer cells over several days and watch them proliferating. Then we hit them with the drugs and watch the drugs block the cells from proliferating. Then, after a couple of days, we can see a subset of cells start proliferating again.

Q: What sparked your interest in this research?

I've always been interested in outliers. And I've always been interested in cancer cells, because they have such an interesting mixture of adaptive and maladaptive features -- features that make them proliferate faster but are an Achilles heel as well. I like the philosophical juxtaposition of combining that with this idea of outliers and heterogeneity. Every cell is unique. Even genetically identical cells aren't truly identical, because they could have a little more of protein X and a little less of protein Y at any given moment. When it comes to drug resistance, these chance events can make a cell an outlier on one particular day, and that could be the day the drug comes along. Now that cell has a completely different fate.

Q: You just won two awards to further this research. What was that like?

I submitted a very similar grant application to both, because each funding agency only gives out a handful of these awards. I didn't think this would be a problem, because I wasn't expecting to get either one! Then I found out that I had gotten both and thought I'd have to choose between them, but when I reported my situation to the two foundations, they said, "Don't you worry about it. We'll sort it out." And they decided to co-fund the grant.

Q: How will you use the grant?

One of the things we saw about the cells that escaped the drugs -- cells we have dubbed escapees -- is that they have DNA damage. That's curious, because these drugs are not supposed to be mutagenic. So the first aim of the grant is to understand how these drugs are causing DNA damage. The second finding is the activation of a stress response pathway called ATF4. That pathway is super high in the escapees, but not the non-escapees and not the untreated cells. We know that if you knock that pathway down, you get fewer escapees, but we don't really understand what that pathway is doing for the escapees. Is it helping them escape the drugs? Or is it just helping them survive the stress of cycling in the presence of the drugs? So that's the second aim of the grant, to understand how this ATF4 stress response pathway is enabling or promoting drug escape.

Binge drinking in adolescence is associated with changes in the volume of the cerebellum in young adulthood, a new study from the University of Eastern Finland and Kuopio University Hospital shows. Earlier studies have shown that excessive, long-term alcohol consumption causes damage to the cerebellum in adults, but there is very little data on the effects of adolescent drinking on the cerebellum. The findings were published in Alcohol.

The study included 58 young adults aged 21 to 28 years, whose alcohol consumption had been monitored for the previous ten years. Of the participants, 33 had been heavy drinkers since adolescence, while 25 were light drinkers, consuming little or no alcohol at all. All of them were highly functional and had normal cognitive capacity, and none of them met the diagnostic criteria for alcohol use disorder.

In heavy-drinking participants, magnetic resonance imaging revealed changes in the volume of posterior cerebellar lobules, when compared to participants consuming little or no alcohol at all.

"These areas of the brain are associated with motor and cognitive functions. However, further research is needed in order to assess the significance and implications of these findings," says Virve Kekkonen, MD, Adolescent Psychiatry Specialist and the lead author of the study.

3,938 moths are part of a major insect study based on artificial intelligence, and researchers from Aarhus University have just published their results in the scientific journal Sensors.

They have developed a counting machine that uses ultraviolet light to attract insects and register them with image recognition. The invention may have a decisive impact on research into climate change and biodiversity.

"If we can monitor the development of moth populations, we can gain new knowledge about how climate change affects our nature. Our technology takes an important step towards automating the very extensive work entailed in counting insects," says Kim Bjerge, associate professor at the Department of Electrical and Computer Engineering at Aarhus University.

Moths are some of our most important markers for climate change, and they are important for global biodiversity. For this reason, biologists are currently spending thousands of hours manually counting moths to monitor developments in the population.

A moth is not just a moth

The challenge is that a moth is not just a moth. There are more than 2,400 different species in Denmark alone, which makes counting and species determination a difficult and time-consuming task.

Today, we catch moths in light traps with a special type of poison. Then we take the dead insects to the laboratory and study them one by one under a microscope.

"Determining the species of moths is a highly specialised task. Our machine can replace much of the manual work, so we can do much larger studies than is possible today. We also avoid having to kill the insects," says Kim Bjerge.

The machine registers the flying insects with a camera which, by means of an algorithm, not only counts the insects, but also determines the species in an instant.

It sounds simple, but there is a lot of interdisciplinary research work behind the insect counter and the artificial intelligence, says Kim Bjerge.

"The biggest challenge has been to train the neural network to recognise a single moth out of several thousand different species and to ensure that it's not counted more than once if it flies past again. Of course, it's absolutely crucial that the technology can be used to monitor the populations of individual species," he says.

The researchers have trained the algorithm in the insect counters with images of moths that have already been species-determined by entomologists.

Intelligent nature monitoring

The intelligent insect counter could pave the way for a completely new form of nature monitoring. Therefore, the researchers in Aarhus are very excited that a large number of international research groups have already shown an interest in implementing the technology as part of their national biodiversity initiatives.

"There are major perspectives in using artificial intelligence to monitor insects. We can study the species without killing one single insect, while at the same time gaining more precise knowledge about their habitats, population status and level of activity from day to day," says Toke Thomas Høye, senior researcher from the Department of Bioscience.

He is the ideas man behind the counter and he will use it in his own research work to monitor how quickly different species of moth are attracted by nature restoration projects.

"We hope that the technology will make it possible for us to monitor moths more systematically. This will help us discover whether some species are disappearing. Moths constitute an important element in the Earth's ecosystems. They perform important functions such as pollination, and they're generally good indicators of the state of nature," he says.

Scientists have witnessed bonobo apes adopting infants who were born outside of their social group for the first time in the wild.

Researchers, including psychologists at Durham University, UK, twice saw the unusual occurrence among bonobos in the Democratic Republic of Congo, in central Africa.

They say their findings give us greater insight into the parental instincts of one of humans' closest relatives and could help to explain the emotional reason behind why people readily adopt children who they have had no previous connection with.

The research, led by Kyoto University, in Japan, is published in the journal Scientific Reports.

Researchers observed a number of bonobo groups over several years in the Wamba area of the Democratic Republic of Congo.

The examples of cross-group adoption were seen between April 2019 and March 2020 before Covid-19 restrictions brought observations to a temporary halt.

Chio, aged between 52 to 57 years old, who is thought to be post-menopausal, was seen to adopt three-year-old Ruby who had been part of another unknown group.

Marie, an 18-year-old bonobo was also seen to adopt Flora, who is estimated to be two-and-a-half-years-old, after Flora's mother disappeared from a separate group.

Neither Chio nor Marie, who had already had their own offspring, had any pre-existing family connections to the adopted infants or any strong social connections with the youngsters' biological mothers, yet both readily adopted the young bonobos.

Both adoptive mothers carried, groomed, nursed, and shared food with their adopted young. Ruby and Flora were also both observed suckling at their adopted mothers. In the case of Ruby, she might have been suckling for comfort as Chio is unlikely to have been producing milk.

The researchers say this caring nature is evidence of bonobos' strong attraction to infants and high tolerance of individuals, including immature youngsters, from outside of their normal group.

Bonobos, along with chimpanzees, are humans' closest relatives and the researchers say their discovery helps us to understand adoption among people.

Marie-Laure Poiret, a PhD Research Student, in the Department of Psychology, at Durham University, UK, said: "Usually in wild animals adoptive mothers are related to orphaned infants or sometimes young females will adopt orphans to improve their own care-giving behaviours, which increases the future survival chances of their own offspring.

"This means that adoption in non-human animals can usually be explained by the adoptive mother's own self-interest or pre-existing social relationships.

"The cross-group adoption we have seen in the cases of both Chio and Ruby, and Marie and Flora, is as surprising as it is wonderful and perhaps helps us explain adoption among humans, which cannot be explained purely by the benefits received by adoptive mothers.

"Instead it is fair to say from the examples we have seen in bonobos that adoption in humans can be explained by a selfless concern for others and an emotional desire to offer care to someone who we have no previous connection with."

The bonobo groups included in this study have been observed by scientists since the 1970s and researchers have come to know the individuals in each of the groups.

Research lead author Nahoko Tokuyama, Assistant Professor in the Primate Research Institute and Wildlife Research Centre at Kyoto University, Japan, who has spent more than ten years studying bonobos in the Democratic Republic of Congo, said bonobos "never ceased to amaze".

Dr Tokuyama added: "Although cases of adoption were observed in non-human primates, the adoptive mother and adoptees almost exclusively belonged to the same social group.

"This may be because adoption is very costly behavior and because non-human primates form stable groups and have a good ability to recognise other group members.

"It's well known that groups of bonobos sometimes encounter and associate with each other, and that those belonging to different groups can interact tolerantly.

"However, I had never imagined that bonobos could adopt infants from outside of their groups, so these cases were quite surprising."

The researchers plan to continue their observations of the bonobo groups once Covid-19 restrictions allow.

Marine heatwaves are dramatically affecting the marine ecosystems of the world and the Mediterranean is no exception. In the Mediterranean, these extreme climate episodes and its resulting massive mortality of species are getting more and more intense and frequent. To date, most of the studies analysed the effects of these perturbations on specific species and populations, although researchers still do not know how this affects the functioning of the involved ecosystems.

A new study led by the University of Barcelona (UB) and the Institute of Marine Sciences (ICM-CSIC) has stated that marine heatwaves are having a strong impact on the functioning of coraligen, one of the most emblematic habitats of the Mediterranean due to the high diversity of species it covers and the high number of ecosystem services it provides.

The study states the loss of the few species that bring structural complexity to these coralline communities, that is, the architects of these habitats. An example of this is the gorgonian coral, which acts as forest trees and offers shelter to a great amount of marine species. According to the study, published in the journal Ecology Letters, gorgonians have been severely affected over the last years by several episodes of massive mortality caused by marine heatwaves in the Mediterranean.

"Gorgonians are sensitive to the climate change. In fact, their abundance has been reduced by 93% in some of the sampled sites where heatwaves have impacted. This is worrying because gorgonians play a critical role in coralligenous assemblages. They are the organisms that provide the three-dimensional structure that allows more than 1600 species to thrive in the coralligenous", says Daniel Gómez-Gras, predoctoral researcher at ICM-CSIC and the UB.

"Thanks to this study, we have been able to verify that the coralligenous reefs are losing the dominance of key functions, which are precisely those provided by the gorgonians", says ICREA professor Cristina Linares, professor at the Departament of Evolutionary Biology, Ecology and Environmental Sciences of Faculty of Biology and member of the Biodiversity Research Institute (IRBio) of the UB. "This implies the loss of essential ecosystem services and the potential decline of species with great commercial value -such as scorpionfish and lobsters-, whose presence would be reduced due to the loss of habitats with high structural complexity" highlights the expert.

Increasing the vulnerability of the ecosystem

Unlike what happens in tropical areas, where many species can act as architects in these habitats, the Mediterranean has only a few, and therefore, they are likely to lose their function, experts warn. The most known ones are the precious coral (Corallium rubrum) and the violescent sea-whip (Paramuricea clavate), the species this study focused on.

"The loss of structural complexity makes coralligenous assemblages more vulnerable to disturbances, as the disappearance of some species makes it difficult for others to survive, leading to an acceleration of the degradation process of the community. It is like if the roof of a building collapses and the windows break. If they are not fixed, the building will eventually collapse", notes ICM-CSIC researcher Joaquim Garrabou, who also participated in this work.

Protected areas are also affected on the inside

To carry out this study, researchers analysed the results from monitoring programs in the Port-Cros National Park and the Scandola Natural Reserve (France), two of the oldest protected marine areas of the Mediterranean, effective on protection and conservation of natural resources. Such programs, carried out for over a decade, have been conducted by the Marine Biodiversity Conservation Group (MedRecover).

With the analyses of demographic and functional traits of coralline species, experts studied how the marine heatwaves affected the functions of these communities in two protected areas. Among the collaborators in the study were the teams of the University of Hawaii System (United States) and the University of Saint Andrews (Scotland, United Kingdom).

The results of the study stress the devastating effects of the climate change, both inside and outside the protected areas, in habitats that are essential for marine life in the Mediterranean, such as coralligenous assemblages. This "will be severely compromised in a near future due to the marine heatwaves", authors warn.

NEW YORK, NY (March 18, 2021)--Therapies that soothe inflammation could be an effective way to prevent heart disease in people with a common age-related blood condition, according to a new study from researchers at Columbia University Vagelos College of Physicians and Surgeons.

The researchers identified how the blood condition, called clonal hematopoiesis, worsens atherosclerosis, and their findings suggest that an anti-inflammatory drug previously tested in a wider population of people with cardiovascular disease may have potential if used only in those with clonal hematopoiesis.

"The main message from our research is that anti-inflammatory therapies for atherosclerotic heart disease may be particularly effective in patients with clonal hematopoiesis," says Alan Tall, MD, the Tilden Weger Bieler Professor of Medicine, the study's co-senior author with Nan Wang, MD, associate professor of medical sciences (in medicine).

Their study was published online March 17 in Nature.

Aging Contributes to Heart Disease

Although great strides have been made in reducing atherosclerotic heart disease with therapies such as statins that reduce cholesterol, many people still have increased disease despite these current treatments.

"Over the years, researchers have learned that the aging process itself is a major contributor to cardiovascular disease," says Trevor P. Fidler, PhD, associate research scientist in medicine, the study's first author. "But how aging itself can lead to heart disease--and how it could be prevented--is not well understood."

Common Blood Condition Increases Heart Disease

In the new study, the researchers took a close look at a common blood condition, called clonal hematopoiesis, that is associated with aging. 

Clonal hematopoiesis is thought to occur in roughly 10% of people over age 70, and most people have no symptoms. But researchers recently realized that the condition--for unknown reasons--raises the risk of heart disease by 40%.

Clonal hematopoiesis occurs when hematopoietic (blood) stem cells acquire mutations. As people age, each hematopoietic stem cell acquires genetic mutations, though most of these mutations have no impact. But in clonal hematopoiesis, some mutations supercharge the stem cell so that it produces a greater number of blood cells compared with other stem cells. 

Study of Mice Reveals Source of Extra Heart Risk

Clonal hematopoiesis usually arises when one of four specific genes is mutated. The Columbia team looked specifically at JAK2, which imparts the strongest risk of premature coronary artery disease. 

In atherosclerosis, white blood cells called macrophages accumulate in plaques and proliferate as the plaque grows.

In studies of mice, the researchers found that the JAK2 mutations led to a number of changes in macrophages that increased macrophage proliferation, increased inflammation in the atherosclerotic plaques, and enhanced the plaque's necrotic core. 

"We know in humans that such regions are associated with unstable plaques, which can rupture, causing heart attacks or strokes," Fidler says.  

The researchers also traced the molecular mechanisms that led to these changes, including increased activation of the AIM2 inflammasome, a complex of proteins that induces inflammation.

Targeting Inflammasome May Reduce Cardiovascular Risk

Inhibiting various components of the inflammasome improved the stability of the plaques, as did inhibition of IL-1ß, a product of the inflammasome.

Though an IL-1ß inhibitor called canakinumab reduced cardiovascular events in a clinical trial, the drug was associated with a small risk of infection and has not been marketed to reduce cardiovascular disease.

"If instead we take a precision medicine approach and only use canakinumab to treat patients with JAK-driven clonal hematopoiesis," Fidler says, "we may increase the cardiovascular benefit. Even if infection risk remains unchanged, we may provide an overall benefit to this specific population."

While the drug tamoxifen reduces the risk of developing breast cancer and prevents recurrence, the side-effects cause many women to discontinue their treatment. A study involving researchers at Karolinska Institutet in Stockholm has now found that a much lower dose than the standard produces a good effect with fewer adverse reactions in women who have yet to enter the menopause. The study, which has been published in the Journal of Clinical Oncology, can play a significant role in the treatment of cancer.

The anti-hormone drug tamoxifen has been used for over 40 years to reduce the risk of relapse in women who have been treated for hormone-related breast cancer. It is also approved as a prophylactic for women with an inherited higher risk of breast cancer.

Women with dense breasts, which is to say breasts with relatively high amounts of firbroglandular tissue to fat tissue, run a four to six-times higher risk of developing breast cancer.

Both dense breast tissue and tumours appear white in mammograms, which makes cancer difficult to detect. Tamoxifen reduces the mammographic density of the breast.

Despite the fact that tamoxifen reduces the risk of breast cancer by up to 40 per cent, it is used relatively infrequently as a prophylactic for healthy women with an increased risk of the disease.

Almost half of the women who take tamoxifen to prevent recurrence after a lumpectomy discontinue treatment prematurely due to a number of known adverse reactions, including menopausal like symptoms such as flushes, sweats, insomnia and various gynaecological problems.

Radiologists, oncologists and researchers at Stockholm Sodersjukhuset Breast Centre, Lund University and Karolinska Institutet have examined the effect of tamoxifen on breast density at a lower dose than the standard 20 mg.

The Karisma study started in 2016 and monitored 1,440 women between the ages of 40 and 74 for just under three years. The women were randomly assigned to six groups of 240, five experimental groups that received a particular dose of tamoxifen (1 2.5, 5, 10 or 20 mg) plus a placebo group.

Before and after the six-month treatment, their mammographic breast density was compared. The women were also asked to report any side effects on a specially designed app.

"Tamoxifen has been shown to reduce mammographic density in women and could be viewed as a proxy for therapy reponse," says principal investigator Professor Per Hall at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. "The established tamoxifen dose is 20 mg, but it turned out that 2.5, 5 and 10 mg reduced the density just as much as 20 mg. At the same time, the adverse reactions reported by the 2.5 mg group were reduced by 50 per cent compared to women who received the 20 mg dose."

The next step for the researchers is to interrogate whether 2.5 mg tamoxifen also reduces the risk of developing breast cancer and can therefore be used to prevent both a first occurrence and recurrence.

"Such a dose-reduction could potentially increase the number of patients who complete their treatment," he says.

There are currently hardly any preventative strategies for reducing breast cancer with the exception for a small group of women with an inherited increased risk. Per Hall welcomes more work on prophylactic treatments:

"One of the problems is that there is no acceptable medication. Another is that there is no effective method of identifying women at a high risk of breast cancer. At present, we're engaged in a project in which we use AI, Artificial Intelligence, to examine mammographic images to find changes that identify women who will develop breast cancer."

Metformin, a drug used to treat type-2 diabetes, could help reduce chronic inflammation in people living with HIV (PLWH) who are being treated with antiretroviral therapy (ART), according to researchers at the University of Montreal Hospital Research Centre (CRCHUM).

Although ART has helped improved the health of PLWH, they are nevertheless at greater risk of developing complications related to chronic inflammation, such as cardiovascular disease. These health problems are mainly due to the persistence of HIV reservoirs in the patients' long-lived memory T cells and to the constant activation of their immune system.

In a pilot study published recently in EBioMedicine (URL), Université de Montréal immunology professor Petronela Ancuta and first author Delphine Planas, a PhD student in her laboratory at the CRCHUM, evaluate the ability of metformin to improve immune function and reduce viral reservoir size.

We asked Professor Ancuta to explain the study.

Q. Despite the use of antiretroviral therapy, seropositive individuals exhibit immune activation and excessive inflammation. In your study, you try to stop that with metformin. How so?

Currently, antiretroviral therapies inhibit HIV replication by preventing the entry of virion (a complete viral particle) into new cells and its exit from infected cells. However, one step is still not targeted by these therapies: the multiplication of the viral genome inside the infected cell.

Despite antiretroviral therapy, this intracellular viral multiplication causes chronic inflammation and immune activation, leading to the emergence of co-morbidities such as cardiovascular disease. In the laboratory, we are working to identify new treatments to inhibit intracellular viral multiplication.

The idea of using metformin in people living with HIV came from Dr.?Jean-Pierre Routy of the Research Institute of the McGill University Health Centre, our collaborator in this study. Used widely in medicine, this drug stimulates or inhibits the reactions of the body's immune system.

In our study, knowing that metformin interferes with the activity of the mTOR (mechanistic target of rapamycin) molecule involved in the intracellular multiplication of HIV genome, we used the drug to treat 22 nondiabetic PLWH on antiretroviral therapy (13 in Montreal and nine in Ottawa). In vitro, studies by our group and others had previously demonstrated that inhibiting mTOR with drugs inhibits HIV replication considerably in the cells of patients infected by the virus.

Q. Did the results of your study surprise you?

Yes, we were excited by the positive results of this pilot study. The drug was extremely well tolerated by the patients and we observed the beneficial biological effects of metformin in colon biopsies.

HIV hides in CD4 T cells, immune system cells that shelter the virus and form viral reservoirs in various peripheral tissues such as the intestine. The virus continues to multiply in these reservoirs and leads to inflammation.

In the study, we observed a reduction in the activation of mTOR in CD4 T cells present in the colon, as well as a decrease in certain plasma markers of inflammation and intestinal damage. Metformin, then, has both intestinal and systemic effects.

Q. HIV reservoir size is linked to the level of inflammation. Could new approaches like yours reduce the size of these reservoirs? Did you observe this in your study?

The viral DNA reservoir size in peripheral blood T cells and in the colon was pretty stable, which is consistent with the known stability of HIV reservoirs. However, we expect that longer treatment may lead to a reduction of these reservoirs. This hypothesis is worth testing.

Q. Will you continue your research with a larger patient sample?

We're going to launch a new randomized study on more than 58 participants in which metformin will be administered over a longer period. We're planning to do it over a six- to 12-month period to validate the benefits of metformin in controlling inflammation, in part by regulating mTOR.

To conclude, I would like to thank the participants in the LILAC study for donating their biological samples and believing in our research efforts, which came to fruition thanks to close collaboration with many researchers, particularly the teams of Drs.?Jean-Pierre Routy and Maged Peter Ghali (McGill University Health Centre), Nicolas Chomont (CRCHUM) and Dr.?Jonathan Angel (Ottawa Hospital Research Institute).