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Pulmonary endarterectomy achieves excellent results for patients with segmental CTEPH

Boston, MA (April 30, 2021) - A new study, presented today at the AATS 101st Annual Meeting, found that patients treated surgically for segmental Chronic Thromboembolic Pulmonary Hypertension (CTEPH) had excellent outcomes with the vast majority doing very well in the long term without any additional treatment other than surgery. In addition, the study found that the proportion of CTEPH patients with segmental disease increased dramatically during the study period - from 2005 to 2020. At the beginning of the study, roughly seven percent of patients were diagnosed with segmental disease. During the last five years of the study, the proportion rose to an average of 41 percent of patients.

CTEPH is a major cause of pulmonary hypertension with Pulmonary endarterectomy

(PEA) showing great success at treating the condition and potentially offering a cure for both proximal and segmental disease. The study performed a comprehensive analysis of all CTEPH patients undergoing PEA at University of Toronto between August 2005 and March 2020. Follow-up was completed for all patients. Disease located at the segmental level and more distally was defined as Jamieson type 3 and compared to more proximal disease defined as Jamieson type 1 and 2 (Type 1-2).

At 12 months, 76 percent of patients with segmental disease who underwent PEA were returned to virtually normal function, with the remaining 24 percent requiring some degree of pulmonary hypertension (PH) therapy and/or balloon angioplasty. Anecdotally, the study found that patients who were treated with PH therapy preoperatively were more likely to require continued PH therapy post-operatively.

According to Dr. Marc de Perrot, Director of the CTEPH program at University of Toronto, while the proportion of patients with segmental disease has increased dramatically, PEA results in excellent long-term outcomes. "Segmental CTEPH is a surgical disease," explained de Perrot. "With surgery, patients show 80 percent long-term survival and good quality of life. The most important factor is a multidisciplinary approach to reassess and provide additional treatment post-operatively if necessary."

Credit: 
American Association for Thoracic Surgery

Most mitral regurgitation patients treated with TEER will require surgery if treatment fails

Boston, MA (May 1, 2021) - A new study, presented today at the AATS 101st Annual Meeting, and simultaneously published in the Journal of the American College of Cardiology, finds that patients suffering from severe mitral regurgitation should be carefully screened and counselled before undergoing transcatheter edge-to-edge mitral repair (TEER). Data showed that up to 95 percent of patients who needed surgery after failed TEER could not have their valves repaired, and needed mitral valve replacement to resolve the issue. The findings highlight the need to select patients carefully for TEER.

As a less invasive approach, TEER is an attractive alternative treatment to mitral valve surgery, particularly in older patients. However, TEER is not currently recommended for younger patients who benefit more from a surgical repair long-term. This caution is supported by this study of 463 patients which provides the first national data on surgical outcomes when TEER fails. The surgical repair rate after failed TEER was only 4.8 percent overall, and 6.8 percent in degenerative disease.

"The fact that TEER takes surgical repair off the table as an option for patients makes it essential that we have a very clear understanding of which patients will benefit. This finding has important implications for treatment choice in lower-risk patients with degenerative disease." said Dr. Joanna Chikwe, chair of the Department of Cardiac Surgery in the Smidt Heart Institute at Cedars-Sinai and the Irina and George Schaeffer Distinguished Chair in Cardiac Surgery in honor of Alfredo Trento, MD. "These findings should inform patient consent for TEER, design of clinical trials, and clinical performance measures."

Results of additional industry studies and an NIH-funded trial comparing TEER to mitral surgery should be published within the next two years and may result in updated guidelines on the use of TEER to treat degenerative mitral regurgitation.

Credit: 
American Association for Thoracic Surgery

WIN's DDPP biomarker to guide cancer therapy and predict response duration

The Worldwide Innovative Network in personalized cancer medicine consortium - WIN Consortium announces the publication of the Digital Display Precision Predictor: the prototype of a global biomarker model to guide treatments with targeted therapy and predict progression-free survival for cancer patients in NPJ Precision Oncology (10.1038/s41698-021-00171-6)

Precision oncology has led to approved, molecularly specific, biomarker-defined indications for targeted therapies. With the number of validated drug targets increasing, testing each patient's tumor for all markers related to all possible targeted therapies becomes infeasible due to limited amount of tissue usually obtained by biopsies. In addition, the current companion diagnostic approach used for most targeted therapies provides limited treatment options, with a binary "yes/no" expected response to a drug and no recommendation for which treatment, among a range of possible options, is likely to be the best option for a particular patient.

The Digital Display Precision Predictor (DDPP), is a biomarker strategy and tool able to predict the duration of progression-free survival (PFS) for multiple targeted treatments for patients with advanced/metastatic cancers, based on the comprehensive investigation of the whole transcriptome (the gene expression profile of the tumor compared to that of normal tissue).

DDPP is based on: 1) the exploration of the whole transcriptome (20,000 genes) providing insight about the status of activation of almost all drug targets in the context of the network of genes or pathways that drive tumor progression; 2) the data can be obtained from a single assessment requiring very small amounts of tumor and analogous normal tissues; and 3) the prediction of the duration of the time until tumor progression (PFS) under a specific therapeutic regimen.

"One of the main challenges of finding new biomarkers is that they are built in a relatively small number of patients treated with the same drug (from the WINTHER trial), for whom both molecular profiles (from tumor and analogous normal tissues) and PFS data were available," said Dr. Josep Tabernero, Vice-Chairman and Chairman of Scientific Advisory Board of WIN, Director, Vall d'Hebron Institute of Oncology, VHIO (Spain) and past ESMO President (2018-2019).

"The DDPP is potentially a new global biomarker tool that can apply to any type of cancer drug used alone or in combination, agnostic of tumor type, and can lead, pending further prospective validation, to a new approach to optimal treatment selection for patients with cancer," concluded Dr. Richard L. Schilsky, Chairman of WIN.

Credit: 
WIN Consortium

Decoding the effect of body mass index on breast cancer

Medical researchers at Flinders University have established a new link between high body mass index (BMI) and breast cancer survival rates - with clinical data revealing worse outcomes for early breast cancer (EBC) patients and improved survival rates in advanced breast cancer (ABC).

In a new study published in a top breast cancer journal- researchers evaluated data from 5 thousand patients with EBC and 3496 with ABC to determine associations between BMI and survival rates across both stages.

Researchers say the results present an 'obesity paradox' which will impact the survival outcomes of the 19,807 women and 167 men diagnosed with breast cancer in Australia in 2020.

Natansh Modi, a NHMRC PHD Candidate at Flinders University, says understanding the biological reasons obesity impacts early and advanced breast cancer survival rates differently will be the key towards developing more effective treatments.

"Higher body mass index (BMI) is associated with an increased risk of developing many types of cancer including breast cancer as a result of elevated levels of circulating sex hormones such as estrogen, estrone, and testosterone, high serum leptin, and chronic inflammation that are associated with high BMI."

Co-author Dr Ashley Hopkins, a Senior Research Fellow at Flinders University, says the study utilises high quality contemporary medicines data to demonstrate higher BMI as independently associated with worse survival in EBC and paradoxically improved survival in advanced disease.

"This is world first evidence of an obesity paradox in breast cancer and highlights an urgent need to understand the biological basis of obesity impacts throughout breast cancer diagnosis and treatment."

Credit: 
Flinders University

Technology provides non-invasive treatment for congenital heart disease patients

WASHINGTON, D.C., (April 30, 2021) - New study results validate the effectiveness of the Medtronic Harmony™ transcatheter pulmonary valve (TPV) system for patients with congenital heart disease (CHD) and severe pulmonary regurgitation (PR). The Harmony TPV is designed to be a less invasive treatment option for patients with irregularity in their right ventricular outflow tract (RVOT) needing pulmonary valve placement to restore valve function. The results of this study are being presented as late-breaking clinical science today at the Society for Cardiovascular Angiography & Interventions (SCAI) 2021 Scientific Sessions.

About 40,000 infants are born with CHD every year in the United States and approximately one in five CHD patients have an abnormality of their right ventricular outflow tract (RVOT) . Prior to TPV technology, CHD patients were treated with invasive procedures such as open-heart surgery or opted for surgical valve replacement later in life. These procedures are associated with high risk for further complications and mortality. The Harmony TPV is designed to be a non-invasive, non-surgical treatment option for these adolescent and adult CHD patients.

The prospective, nonrandomized study was conducted at ten sites in the U.S., Canada, and Japan and included 67 patients who received the valve. Primary safety and effectiveness endpoints included freedom from procedure or device-related mortality at 30 days and percentage of patients with acceptable hemodynamic function at 6 months and no Harmony valve intervention.

Investigators analyzed two sizes of the Harmony valve, a 22-mm valve (TPV22) and a modified version of the original 25-mm valve (mTPV25). Clinical outcomes through one year included no mortality, endocarditis, major stent fractures or need for surgical intervention. One patient underwent a valve-in-valve intervention for residual stenosis. Over 90% of patients reported having little to no pulmonary regurgitation during follow-up visits.

"This is a brand-new class of cardiac devices designated to help a very specific patient population where no less-invasive, percutaneous treatment options were available until now," said Thomas Jones, MD, Principal Investigator and Director, Cardiac Catheterization Laboratories at Seattle Children's Hospital. "Unlike any other TPV, this novel technology is designed to expand into the enlarged RVOT in these patients while simultaneously deploying a suitable bioprosthetic pulmonary valve. The Harmony TPV system has the potential to fundamentally alter the lifetime management of CHD patients from here on out."

In March 2021, the Harmony TPV system was granted U.S. Food and Drug Administration (FDA) approval for use in the U.S. Additionally, investigators plan to follow-up through 5 years. A post approval study will also be conducted with follow-up to 10-years.

Credit: 
Society for Cardiovascular Angiography and Interventions

Prior SARS-CoV-2 infection rescues B and T cell responses to variants after first vaccine

A single dose of vaccine boosts protection against SARS-CoV-2 coronavirus variants, but only in those with previous COVID-19, a study has found.

In those who have not previously been infected and have so far only received one dose of vaccine the immune response to variants of concern may be insufficient.

The findings, published today in the journal Science and led by researchers at Imperial College London, Queen Mary University of London and University College London, looked at immune responses in UK healthcare workers at Barts and Royal Free hospitals following their first dose of the Pfizer/BioNTech vaccine.*

They found that people who had previously had mild or asymptomatic infection had significantly enhanced protection against the Kent and South Africa variants, after a single dose of the mRNA vaccine. In those without prior COVID-19, the immune response was less strong after a first dose, potentially leaving them at risk from variants.

Professor Rosemary Boyton, Professor of Immunology and Respiratory Medicine at Imperial College London, who led the research, said: "Our findings show that people who have had their first dose of vaccine, and who have not previously been infected with SARS-CoV-2, are not fully protected against the circulating variants of concern. This study highlights the importance of getting second doses of the vaccine rolled out to protect the population."

Blood samples were analysed for the presence and levels of immunity against the original strain of SARS-CoV-2, as well as the Kent (B.1.1.7) and South Africa (B.1.351) variants of concern. Along with antibodies - the Y-shaped proteins which stick to the virus and help block or neutralize the threat - the researchers also focused on two types of white blood cell: B-cells, which 'remember' the virus; and T cells, which help B cell memory and recognise and destroy cells infected with coronavirus.

They found that after a first dose of vaccine, prior infection was associated with a boosted T cell, B cell and neutralizing antibody response, which could provide effective protection against SARS-CoV-2, as well as the Kent and South Africa variants.

However, in people without previous SARS-CoV-2 infection, a single vaccine dose resulted in lower levels of neutralizing antibodies against SARS-CoV-2 and the variants, potentially leaving them vulnerable to infection and highlighting the importance of the second vaccine dose.

The team looked at two variants of concern, however, they think it possible that the findings will apply to other variants in circulation, such as the Brazil (P.1) and India (B.1.617 and B.1.618) variants.

It remains unclear precisely how much protection is offered by T cells. Interestingly, the mutations in the Kent and South Africa variants here resulted in T cell immunity which could be reduced, enhanced or unchanged compared to the original strain, depending on genetic differences between people.

Professor Boyton commented: "Our data show that natural infection alone may not provide sufficient immunity against the variants. Boosting with a single vaccine dose in people with prior infection probably does. As new variants continue to emerge, it is important to fast track global rollout of vaccines to reduce transmission of the virus and remove the opportunities for new variants to arise."

Professor Danny Altmann, Professor of Immunology at Imperial, commented: "At a time of generally improving outlook in those countries with substantial vaccine rollout programmes, this study reminds us of the need to be vigilant about the threat of the variants. Most vaccinated people in the UK have received just one dose. While we know this offers remarkable protection against the original virus, our data suggest this leaves people susceptible to variants of concern."

Professor Áine McKnight, of Queen Mary University of London, said: "Our study offers reassurance and a warning. We show that current vaccines offer some protection against variants of concern. However, people who have received only the first course of a double dose vaccine show a more muted immune response. We must ensure that the global vaccination programme is fully implemented. Current events in India make painfully clear the cost of complacency."

Professor James Moon, of University College London and Barts, said: "These results represent collaborative science at its best between hospitals, universities and public bodies providing important timely results to inform policy and strategy."

Credit: 
Imperial College London

The Lancet: Study confirms greater risk of poor COVID outcomes in minority ethnic groups in England

Largest study so far of more than 17 million adults in England confirms that minority ethnic groups had a higher risk of testing positive, hospitalisation, admission to intensive care units (ICU), and death from COVID-19 compared with white groups, even after accounting for other factors known to increase risk like deprivation, occupation, household size and underlying health conditions.

Disparities for hospitalisation and death lessened for most minority ethnic groups between pandemic waves 1 (February to September 2020) and wave 2 (September to December 2020), but increased for South Asian groups.

To tackle ethnic disparities in COVID-19 risks, the authors call for reducing structural disadvantage and inequality, improving quality of and access to healthcare, and improving uptake of testing and vaccination. They also stress the need for more intensive strategies tailored to improve outcomes in South Asian communities.

Minority ethnic groups had higher risk of testing positive for SARS-CoV-2 and of COVID-19-related hospitalisations, intensive care (ICU) admissions and death compared with white groups in England, according to an observational study published in The Lancet.

The COVID-19 pandemic is understood to have had a disproportionate impact on minority ethnic communities in the UK and beyond. This study accounted for a large number of explanatory variables such as household size, social factors and health conditions across all ethnic groups and at different stages of COVID-19, from testing to mortality. Understanding drivers of SARS-CoV-2 infection and COVID-19 in minority ethnic communities will be crucial to public policy efforts to overcome inequalities.

"Minority ethnic groups in the UK are disproportionately affected by factors that also increase the risk for poor COVID-19 outcomes, such as living in deprived areas, working in front-line jobs, and having poorer access to healthcare. Our study indicates that even after accounting for many of these factors, the risk for testing positive, hospitalisation, ICU admission and death was still higher in minority ethnic groups compared with white people in England. To improve COVID-19 outcomes, we urgently need to tackle the wider disadvantage and structural racism faced by these communities, as well as improving access to care and reducing transmission," says lead author, Dr Rohini Mathur of the London School of Hygiene and Tropical Medicine, UK. [1]

On behalf of NHS England, the research team used the new secure OpenSAFELY data analytics platform to analyse partially anonymised electronic health data collected by GPs covering 40% of England. These GP records were linked to other national coronavirus-related data sets for the first and second waves of the pandemic - including testing, hospital data and mortality records. Ethnicity was self-reported by participants in GP records and grouped into five census categories (white, South Asian, Black, other, mixed) and then a further 16 sub-groups.

Possible explanatory factors, including clinical characteristics, such as BMI, blood pressure, smoking status and conditions such as asthma and diabetes were included in the analyses alongside demographic information such as age, sex, deprivation and household size.

Of 17,288,532 adults included in the study, 63% (10,877,978) were white, 5.9% (1,025,319) South Asian, 2% (340,912) Black, 1.8% (320,788) other, and 1% (170,484) mixed. Ethnicity was unknown for 26.3% (4,553,051) people.

During wave 1, nearly all minority ethnic groups had higher relative risk for testing positive, hospitalisation, ICU admission, and death compared to white groups. The largest disparities were seen in ICU admissions, which were more than doubled for all minority ethnic groups compared with white groups, with Black people more than three times more likely to be admitted to ICU after accounting for other factors.

The proportion of people testing positive for SARS-CoV-2 in wave 1 was higher in South Asian groups (0.9% test positivity), Black (0.7%) and mixed groups (0.5%) and compared with white people (0.4%).

"Higher risks for testing positive and subsequent poor outcomes amongst minority ethnic groups suggest that people may delay seeking testing or accessing care for SARS-CoV-2. This may be due to lack of access to testing sites or conflicting health messaging. It may also suggest that some may be fearful of losing income or employment if required to quarantine after testing positive as minority ethnic groups are more likely to work in insecure jobs with poorer workplace protections. People who need to be tested as well as those who test positive must be supported better if we are to reduce disparities in COVID-19 outcomes," says Dr Mathur. [1]

Compared with wave 1, the relative risk for testing positive, hospitalisation, ICU admission, and death were smaller in pandemic wave 2 for all minority ethnic communities compared to white people, with the exception of South Asian groups. South Asian groups remained at higher risk for testing positive, with relative risks for hospitalisation, ICU admission, and death greater in magnitude in wave 2 compared to wave 1.

"Despite the improvements seen in most minority ethnic groups in the second wave compared to the first, it's concerning to see that the disparity widened among South Asian groups. This highlights an urgent need to find effective prevention measures that fit with the needs of the UK's ethnically diverse population," says Dr Mathur. [1]

After accounting for age and sex, social deprivation was the biggest potential explanatory factor for disparities in all minority ethnic groups except South Asian. In South Asian groups, health factors (e.g., BMI, blood pressure, underlying health conditions) played the biggest role in explaining excess risks for all outcomes. Household size was an important explanatory factor for the disparity for COVID-19 mortality in South Asian groups only.

"While multigenerational living may increase risk of exposure and transmission (from children or working age adults to older or vulnerable family members), such households and extended communities also offer valuable informal care networks and facilitate engagement with health and community services. In light of emerging evidence that minority ethnic groups are less likely to take up the COVID-19 vaccine, co-designing culturally competent and non-stigmatising engagement strategies with these communities is increasingly important," says Dr Mathur. [1]

The authors caution that there are some limitations to the study including an inability to capture all potential explanatory variables, including occupation, health-related behaviours, and experiences of racism or structural discrimination. They call for improving the completeness of ethnicity recording in health data to further support the conduct of high quality research into addressing health inequalities for COVID-19 and beyond.

Writing in a linked Comment, Dr Daniel Morales, University of Dundee, UK, and Dr Sarah Ali, Royal Free London NHS Foundation Trust, UK, (who were not involved in the study), said: "The pressing challenge is now ensuring that COVID-19 vaccination programmes are rolled out effectively amongst all minority ethnic groups. Key to this, will be ensuring that vaccine hesitancy is urgently addressed. There are reports of increased hesitancy in minority ethnic groups, including those working in front-line health and social care roles, who knowingly face an increased risk of contracting COVID-19. Unless vaccine hesitancy is tackled head on, differential vaccine uptake may further exacerbate health inequalities faced by minority ethnic groups."

Credit: 
The Lancet

Vaccines bring us closer

image: World Health Organization (WHO) Member States affirmatively reporting national adult immunisation programmes, by WHO Region and worldwide, 2018

Image: 
Eurosurveillance, WHO

Effectively and safely protecting against disease--this is what makes vaccines a vital and successful public health tool that saves lives and safeguards health and well-being. Today, vaccines shield us from more than 20 life-threatening diseases.

Each year, between 2 to 3 million lives are saved by immunisation against diseases like diphtheria, tetanus, pertussis, influenza or measles [1]. However, several vaccines such as the one against measles can only reach their full potential--protecting not just those who are immunised, but also those who might not be eligible for vaccination--if the vaccination coverage in a population is high enough [2].

Looking at immunisation programmes' successes and remaining challenges, this week's issue of Eurosurveillance is published on the occasion of European Immunization Week (EIW), from 26 April to 2 May 2021. The campaign, observed annually in the last week of April, was established by the World Health Organization (WHO) Regional Office for Europe in 2005 and aims to highlight the benefits of routine immunisation and to support national immunisation systems.

This year's EIW slogan, 'Vaccines bring us closer', embraces coronavirus disease (COVID-19) vaccines as an integral part of the response to end the ongoing pandemic and ease the physical distancing measures that have been implemented to help control it [3].

Thanks to routine vaccination--which has helped to eradicate for example smallpox and to protect against other diseases with potentially serious health consequences [4]--we know that vaccines work. Yet, WHO estimates that around 20 million children worldwide do not receive the vaccines they need or miss out on vaccination later in life [5].

Vaccines are most often administered to infants and children as part of routine national vaccination schedules. But immunisation protection reaches further than childhood and is important for people in all stages of life, from teenagers to adults and elderly people. Providing such lifelong protection poses further challenges for vaccination programmes, including ensuring equitable access to vaccines [6].

The editorial in this Eurosurveillance issue outlines the lessons learnt since the outset of the coronavirus disease (COVID-19) pandemic, with regards to rapid vaccine development, authorisation, procurement, distribution and administration in large vaccination campaigns. It looks at the key considerations for national vaccine decision-making--during a pandemic or otherwise--and the role that National Immunisation Technical Advisory Groups (NITAGs) or equivalent bodies play when they advise their governments on how to best use new vaccines or design national immunisation programmes.

Also in this issue, Williams et al. documented and quantified immunisation programmes for adults across 194 WHO Member States in order to assess existing infrastructures' suitability for COVID-19 vaccine deployment. Looking at five vaccines licensed for adult immunisation (hepatitis B, herpes zoster, influenza, pneumococcal conjugate and pneumococcal polysaccharide vaccines), the authors found that of the 194 WHO Member States, 120 (62%) reported having at least one adult vaccination programme in 2018, and that 59% of countries had adult vaccination programmes for influenza.

High- or upper-middle-income countries were found to be significantly more likely to report adult immunisation programmes, with country income serving as the most strongly associated factor overall in a multivariable analysis. Other significantly associated factors in a bivariable analysis included meeting National Immunisation Technical Advisory Group (NITAG) basic functional indicators, having introduced new or underused vaccines and having achieved paediatric vaccine coverage goals.

Based on their assessment, Williams et al. conclude that almost 40% of the assessed countries have no infrastructure for adult immunisation and that even the presence of a national adult vaccination programme does not guarantee extensive use of vaccines in the adult population [7].

One target group for adult vaccination is healthcare workers, given that they are exposed to vaccine-preventable diseases like measles, mumps, pertussis and varicella at work and can also transmit these to patients.

In their article, von Linstow et al. detected immunity gaps mainly among young healthcare workers. In addition, considerable proportions of healthcare workers in the study reported that they were unsure about their vaccination status (22-32%, depending on the disease) and possible previous infections (11% for varicella and 41% for pertussis). According to the authors, this demonstrates the need for more targeted measures like screening and a vaccine strategy to address these gaps in healthcare workers [8].

Specifically for measles and its related elimination goal, coverage and uptake of routine childhood immunisation programmes have to improve in many European countries in the same way that immunity gaps in adolescents and adults need to be addressed [9].

In their paper, Rohleder et al. examine a possible relationship between socioeconomic deprivation and measles incidence in Germany, taking into account demographic, spatial and temporal factors [10]. They conclude that the risks for measles infections are higher and more concentrated in areas with the highest socioeconomic status.

In a study of 6,423 healthcare workers in Italy who received the Comirnaty vaccine (BNT162b2, BioNTech/Pfizer, Mainz, Germany/New York, United States), Fabiani et al. found that the effectiveness of preventing SARS-CoV-2 infection was 84% (95% confidence interval (CI): 40-96) 14-21 days after receiving the first dose and 95% (95% CI: 62-99) at least 7 days after the second dose. According to the authors, these results could support the ongoing COVID-19 vaccination campaigns with evidence for targeted communication [11].

Vaccination may be receiving more attention than usual right now, as many adults worldwide are currently being vaccinated or awaiting their opportunity to receive protection against COVID-19. Topics around vaccine safety and efficacy, ethical and equity considerations, as well as logistics are being discussed more widely and more intensely. In this context, EIW serves to highlight the ongoing need to increase efforts to achieve better vaccination coverage for all vaccine-preventable diseases, in order to prevent disease and protect individuals beyond the COVID-19 pandemic.

Credit: 
European Centre for Disease Prevention and Control (ECDC)

Illnesses of controversial celebrities can negatively affect public health

UNIVERSITY PARK, Pa.-- Not all public figures are equally beloved, and sometimes when more controversial celebrities get sick, it may negatively affect people's health intentions. In a study of people's reactions to radio host Rush Limbaugh's announcement of a lung cancer diagnosis and Kentucky Sen. Rand Paul's announcement of a diagnosis of COVID-19, researchers at Penn State found that those who took pleasure in their misfortune were themselves less likely to take steps to prevent lung cancer or COVID-19.

"Schadenfreude is the emotion of feeling pleasure in another's misfortune," said Jessica Gall Myrick, associate professor of media studies. "In our study, after learning the news of a politician's illness, if people felt schadenfreude, they were much less likely to intend to take the actions that would prevent either lung cancer or COVID-19."

In general, previous research by Myrick has found that coverage of celebrity ailments can raise public awareness of serious illnesses, which can then serve as a motivation for people to avoid bad activities or start new healthy routines. But most studies on the topic examine how the public responds to well-liked celebrities. Respondents were not asked if they liked or disliked the person reporting the illness in the current study, but rather if they felt schadenfreude upon hearing the news of Limbaugh and Paul.

Myrick and doctoral student Jin Chen of the Donald P. Bellisario College of Communications recently conducted two online surveys shortly after news coverage of illnesses associated with two provocative public figures. Their results were published in Journalism and Mass Communication Quarterly.

The first survey was conducted with 414 American adults following Limbaugh's February 2020 announcement that he was diagnosed with advanced lung cancer. The second survey was conducted in March 2020 to 407 American adults following Paul's announcement that he had been diagnosed with COVID-19. Paul was the first national politician to confirm a diagnosis. Respondents were recruited and the surveys were conducted using Amazon Mechanical Turk.

The researchers tested the idea that when the average person sees news coverage about the illness of a public figure that they do not like, then they can experience the emotion of schadenfreude. They examined how that feeling affected people's intentions to prevent themselves from getting sick after hearing the news about Limbaugh and Paul, respectively.

Both of these surveys showed the same pattern; the respondents who felt greater schadenfreude toward Limbaugh and Paul after learning of their illnesses were less inclined to take the steps to prevent lung cancer and COVID-19.

Political ideology was not related to feelings of schadenfreude, according to these studies. The only factor that could predict how much schadenfreude people felt was how well they believed they knew these famous individuals through the media.

"The more media exposure people had to these political figures, and the more familiar people felt they were knowledgeable about the political figures, the more pleasure they experienced in learning of their illness," Myrick said. "That pleasure in the political figure's pain seemed to demotivate people to take action to protect themselves."

Myrick added that schadenfreude is a positive emotion and when "we feel happy and pleased, we also feel safe." This may be the reason people are less likely to avoid the health risks.

"Basically, why would we do anything to alter this good feeling by confronting a depressing health threat and thinking about bad things that could happen to us?" Myrick said. "Because schadenfreude puts us in a pleasant, pleasureful state, we let our guards down for risks to our own health."

The findings could have serious public health implications, according to Myrick. It makes it hard for health advocates to convince some segments of the population to take preventative actions when controversial political figures get sick.

"We need additional research to figure out the underpinnings of these feelings to see if there are other ways," she said. "Either through encouraging empathy for the ill or maybe even by better channeling the feelings of schadenfreude toward positive action."

Credit: 
Penn State

Antiviral T cells safe and effective for treating debilitating complication common after stem cell transplants

image: A Phase II trial at MD Anderson tound that BK virus (BKV)-specific T cells from healthy donors were safe and effective as an off-the-shelf therapy for BKV-associated hemorrhagic cystitis (BKV-HC), a painful complication common after allogeneic stem cell transplants for patients with leukemia or lymphoma.

Image: 
MD Anderson Cancer Center

HOUSTON ? A Phase II trial led by researchers at The University of Texas MD Anderson Cancer Center found that BK virus (BKV)-specific T cells from healthy donors were safe and effective as an off-the-shelf therapy for BKV-associated hemorrhagic cystitis (BKV-HC), a painful complication common after allogeneic stem cell transplants for patients with leukemia or lymphoma. The study was published today in the Journal of Clinical Oncology.

Infusion of T cells targeting BKV resulted in rapid responses, with 67.7% of patients seeing a complete or partial improvement in symptoms after 14 days. This increased to 81.6% of patients after 28 days post-infusion. No cases of grade 3 or grade 4 graft versus host disease (GVHD) or other infusion-related toxicities occurred.

Addressing a debilitating complication caused by BKV

"BKV-associated hemorrhagic cystitis is an incredibly painful condition that causes significant morbidity in patients and can lead to worse cancer outcomes in the long term. Unfortunately, there are no effective treatments available," said corresponding author Katy Rezvani, M.D., Ph.D., professor of Stem Cell Transplantation and Cellular Therapy. "We were driven to develop this therapy to provide a better option for these patients, and this has emerged as a safe and effective therapy for patients at MD Anderson based on these results."

BKV is a human polyomavirus acquired by most people in early childhood, Rezvani explained. Held in check by the immune system, BKV typically remains inactive in the cells lining the urinary tract, including the kidney, bladder and ureters.

Allogeneic stem cell transplants, in which stem cells come from a matched donor, require patients to be given therapies to suppress the immune system and prevent rejection. However, this also can trigger the BKV to begin reproducing and cause severe cystitis, which can result in hospitalization for days or weeks. An antiviral called cidofovir has been used as a treatment but is associated with significant toxicities.

Developing antiviral T-cell therapies

Recognizing that these viral infections can profoundly impact patient recovery, Rezvani and her research team led the development of antiviral T-cell therapies with the support of the MDS and AML Moon Shot®, part of the institution's Moon Shots Program®, a collaborative effort to rapidly develop scientific discoveries into meaningful clinical advances that save patients' lives.

Beginning with blood samples taken from healthy donors, the research team is able to isolate T cells and grow them to specifically recognize and target a variety of antigens found on the BKV. These cells are expanded in the clinical good manufacturing practice (GMP) laboratory, under the leadership of Elizabeth J. Shpall, M.D., professor of Stem Cell Transplantation and Cellular Therapy. From each donor, the team can manufacture anywhere from 20 to 50 doses of antiviral T cells, which are stored until needed, Rezvani said.

In a previous trial published in the New England Journal of Medicine, these researchers showed that BKV-specific T cells can effectively treat infection with the JC virus, a genetically similar polyomavirus that causes progressive multifocal leukoencephalopathy (PML), a rare and often fatal brain infection.

BKV-specific T cells get positive results in trial

The current trial enrolled a total of 59 MD Anderson patients experiencing BKV-HC following an allogeneic stem cell transplant. Patients had a median age of 47 and were being treated for a variety of hematological conditions, the most common being acute myeloid leukemia. Women accounted for 40.7% of participants and men for 59.3%. Among trial participants, 55.9% (33) were white, 18.6% (11) were Hispanic, 15.3% (9) were African-American, 6.8% (4) were Middle-Eastern and 3.4% (2) were Asian.

Patients received a single infusion of partially human leukocyte antigen (HLA)-matched T cells, with the option to receive additional infusions every two weeks, if needed.

Following infusion, the researchers did not observe any side effects that were likely attributed to the antiviral T cells. No infusion-related toxicities, low blood-cell counts or graft failures were found. Several patients developed delayed cases of low-grade GVHD in the weeks and months following treatment, which were well within the expected rates of GVHD for these patients early after allogeneic stem cell transplant, Rezvani explained.

The median time for patients to have a partial response was 14 days, and the median time to complete response was 21 days. The estimated probability of achieving a complete response was nearly 70% by day 45, indicating continuous activity of the infused cells. Responses were durable and no patients saw their symptoms return after a previously achieved response.

After studying participants on the trial, the researchers determined that expansion of the infused T was positively correlated with patient responses.

"We are extremely encouraged by the safety of this treatment and the rapid responses we've seen in the majority of patients," Rezvani said. "Because this approach is so safe, we've been able to offer this treatment as an outpatient procedure as soon as patients begin developing symptoms. This has been life-changing for the patients we've been able to treat so far."

In the future, the researchers aim to validate these findings in a multi-institutional study and bring this treatment option to many more patients in need.

Credit: 
University of Texas M. D. Anderson Cancer Center

The Lancet: Many more people could benefit from blood pressure-lowering medication

Most detailed study to date including 345,000 people from 48 randomised clinical trials finds that blood pressure-lowering medication is effective in adults regardless of starting blood pressure level.

Each 5mmHg reduction in systolic blood pressure lowered the relative risk of cardiovascular events by around 10%, even in people with normal blood pressure and those who had never had a heart attack or stroke.

Authors call for global guidelines to be changed so that anyone with increased risk of cardiovascular disease is considered for blood-pressure lowering medication, irrespective of their blood pressure.

Blood pressure-lowering medication can prevent serious cardiovascular conditions such as strokes, heart failure and heart attacks even in adults with normal blood pressure, according to new research published in The Lancet.

Importantly, the study found the beneficial effects of treatment were similar regardless of the starting blood pressure level, in both people who had previously had a heart attack or stroke and in those who had never had heart disease.

The authors say that the findings have immediate and important implications for global clinical guidelines that typically limit blood pressure-lowering treatment to individuals with high blood pressure (usually above 140/90 mmHg).

"Our findings are of great importance to the debate concerning blood pressure treatment", says lead author Professor Kazem Rahimi, University of Oxford, UK. "This new and best available evidence tells us that decisions to prescribe blood pressure medication should not be based simply on a prior diagnosis of cardiovascular disease or an individual's blood pressure level. Instead, medication should be viewed as an effective tool for preventing cardiovascular disease in people at increased risk of developing heart disease or stroke. Clinical guidelines should be changed to reflect these findings." [1]

He cautions, "We're not saying that everyone must begin treatment. The decision will depend on an individual's risk factors for developing cardiovascular disease, the potential for side effects and patient choice." [1]

Heart disease and stroke, linked to high blood pressure, are the leading cause of death across most of the western world. It is widely accepted that blood pressure medication protects people who have had a prior heart attack or stroke from having a second, but the use of these drugs in people with normal or mildly elevated blood pressure has been debated [2]. So far, studies examining whether blood pressure-lowering medication is equally beneficial in people with and without a history of cardiovascular disease, and at lower blood pressure levels than currently considered for treatment (typically 140/90 mmHg or higher) have reported conflicting findings. This has led to contradictory treatment recommendations around the world.

For the current analysis, the Blood Pressure Lowering Treatment Triallists' Collaborators pooled data from 344,716 adults (average age 65 years) in 48 randomised trials (the gold standard for evaluating the effectiveness of treatments) to explore the effects of blood pressure-lowering medications. Participants were separated into two groups: those with a prior diagnosis of cardiovascular disease (157,728 participants - secondary prevention group) and those without (186,988 - primary prevention group, without cardiovascular disease).

Each group was then divided into seven subgroups based on levels of systolic blood pressure at study entry (less than 120, 120-129, 130-139, 140-149, 150-159, 160-169, 170 and above mmHg). Around 20% (31,239) of participants with prior cardiovascular disease and 8% (14,928) of those who had never had cardiovascular disease had normal or high-normal systolic blood pressure at the start of the trials (systolic blood pressure less than 130 mmHg).

Over an average of four years follow-up, 42,324 participants had at least one major cardiovascular event (heart attack, stroke, heart failure, or death from cardiovascular disease). For every 5 mmHg reduction in systolic blood pressure, the risk of developing major cardiovascular disease fell by around 10% (18,287 vs 24,037 major cardiovascular disease in the intervention and comparator groups, respectively), stroke by 13% (6,005 vs 7,767), heart failure by 13% (3,249 vs 4,584), ischaemic heart disease by 8% (8,307 vs 11,145), and death from cardiovascular disease by 5% (4,825 vs 6,110).

The beneficial effects of the treatment did not differ based on a history of having had cardiovascular disease or the level of blood pressure at study entry.

"It is important that people are considered for blood pressure-lowering treatment based on their cardiovascular risk, rather than focusing on blood pressure itself as a qualifying factor for or target of treatment," says co-author Zeinab Bidel from the University of Oxford, UK. "We must provide well-rounded guidelines to lower risks for cardiovascular disease that include exercise, nutrition, smoking cessation, and - where appropriate - medication." [1]

The study has some limitations including that it only investigated the impact of starting blood pressure and prior cardiovascular disease on treatment effects, so the findings cannot be generalised to other patient characteristics that we have not included in our analysis. Additionally, the effects on diseases other than major cardiovascular disease, including potential side effects of treatment, were not specifically examined.

Credit: 
The Lancet

Multi-drug resistant infection about to evolve within cystic fibrosis patients

Scientists have been able to track how a multi-drug resistant organism is able to evolve and spread widely among cystic fibrosis patients - showing that it can evolve rapidly within an individual during chronic infection. The researchers say their findings highlight the need to treat patients with Mycobacterium abscessus infection immediately, counter to current medical practice.

Around one in 2,500 children in the UK is born with cystic fibrosis, a hereditary condition that causes the lungs to become clogged up with thick, sticky mucus. The condition tends to decrease life expectancy among patients.

In recent years, M. abscessus, a species of multi-drug resistant bacteria, has emerged as a significant global threat to individuals with cystic fibrosis and other lung diseases. It can cause a severe pneumonia leading to accelerated inflammatory damage to the lungs, and may prevent safe lung transplantation. It is also extremely difficult to treat - fewer than one in three cases is treated successfully.

In a study published today in Science, a team led by scientists at the University of Cambridge examined whole genome data for 1,173 clinical M. abscessus samples taken from 526 patients to study how the organism has evolved - and continues to evolve. The samples were obtained from cystic fibrosis clinics in the UK, as well as centres in Europe, the USA and Australia.

The team found two key processes that play an important part in the organism's evolution. The first is known as horizontal gene transfer - a process whereby the bacteria pick up genes or sections of DNA from other bacteria in the environment. Unlike classical evolution, which is a slow, incremental process, horizontal gene transfer can lead to big jumps in the pathogen's evolution, potentially allowing it to become suddenly much more virulent.

The second process is within-host evolution. As a consequence of the shape of the lung, multiple versions of the bacteria can evolve in parallel - and the longer the infection exists, the more opportunities they have to evolve, with the fittest variants eventually winning out. Similar phenomena have been seen in the evolution of new SARS-CoV-2 variants in immunocompromised patients.

Professor Andres Floto, joint senior author from the Centre for AI in Medicine (CCAIM) and the Department of Medicine at the University of Cambridge and the Cambridge Centre for Lung Infection at Royal Papworth Hospital, said: "What you end up with is parallel evolution in different parts of an individual's lung. This offers bacteria the opportunity for multiple rolls of the dice until they find the most successful mutations. The net result is a very effective way of generating adaptations to the host and increasing virulence.

"This suggests that you might need to treat the infection as soon as it is identified. At the moment, because the drugs can cause unpleasant side effects and have to be administered over a long period of time - often as long as 18 months - doctors usually wait to see if the bacteria cause illness before treating the infection. But what this does is give the bug plenty of time to evolve repeatedly, potentially making it more difficult to treat."

Professor Floto and colleagues have previously advocated routine surveillance of cystic fibrosis patients to check for asymptomatic infection. This would involve patients submitting sputum samples three or four times a year to check for the presence of M. abscessus infection. Such surveillance is carried out routinely in many centres in the UK.

Using mathematical models, the team have been able to step backwards through the organism's evolution in a single individual and recreate its trajectory, looking for key mutations in each organism in each part of the lung. By comparing samples from multiple patients, they were then able to identify the key set of genes that enabled this organism to change into a potentially deadly pathogen.

These adaptations can occur very quickly, but the team found that their ability to transmit between patients was constrained: paradoxically, those mutations that allowed the organism to become a more successful pathogen within the patient also reduced its ability to survive on external surfaces and in the air - the key mechanisms by which it is thought to transmit between people.

Potentially one of the most important genetic changes witnessed by the team was one that contributed towards M. abscessus becoming resistant to nitric oxide, a compound naturally produced by the human immune system. The team will shortly begin a clinical trial aimed at boosting nitric oxide in patients' lung by using inhaled acidified nitrite, which they hope would become a novel treatment for the devastating infection.

Examining the DNA taken from patient samples is also important in helping understand routes of transmission. Such techniques are used routinely in Cambridge hospitals to map the spread of infections such as MRSA and C. difficile - and more recently, SARS-CoV-2. Insights into the spread of M. abscessus helped inform the design of the new Royal Papworth Hospital building, opened in 2019, which has a state-of-the-art ventilation system to prevent transmission. The team recently published a study showing that this ventilation system was highly effective at reducing the amount of bacteria in the air.

Professor Julian Parkhill, joint senior author from the Department of Veterinary Medicine at the University of Cambridge, added: "M. abscessus can be a very challenging infection to treat and can be very dangerous to people living with cystic fibrosis, but we hope insights from our research will help us reduce the risk of transmission, stop the bug evolving further, and potentially prevent the emergence of new pathogenic variants."

The team have used their research to develop insights into the evolution of M. tuberculosis - the pathogen that causes TB about 5,000 years ago. In a similar way to M. abscessus, M. tuberculosis likely started life as an environmental organism, acquired genes by horizontal transfer that made particular clones more virulent, and then evolved through multiple rounds of within-host evolution. While M. abscessus is currently stopped at this evolutionary point, M. tuberculosis evolved further to be able to jump directly from one person to another.

Dr Lucy Allen, Director of Research at the Cystic Fibrosis Trust, said: "This exciting research brings real hope of better ways to treat lung infections that are resistant to other drugs. Our co-funded Innovation Hub with the University of Cambridge really shows the power of bringing together world-leading expertise to tackle a health priority identified by people with cystic fibrosis. We're expecting to see further impressive results in the future coming from our joint partnership."

Credit: 
University of Cambridge

COVID-19 stress and remote schools worsened youth mental health

A survey of over 32,000 caregivers of youth in Chicago Public Schools found that around a quarter of children and adolescents were described as stressed, anxious, angry or agitated after pandemic-related school closures and the switch to remote learning. Around a third of youth were described by caregivers as lonely and only one-third were described as having positive social and peer relationships. Across the board, caregivers reported significantly worse psychological well-being after school closures as compared to before. Findings were published in the journal JAMA Network Open.

"Caregivers are reporting that the pandemic and school closures have taken a substantial emotional toll on their children and adolescents," said lead author Tali Raviv, PhD, clinical psychologist at Ann & Robert H. Lurie Children's Hospital of Chicago Center for Childhood Resilience and Associate Professor of Psychiatry and Behavioral Sciences at Northwestern University Feinberg School of Medicine. "Greater public attention to youth mental health issues during this time can help appropriately allocate resources and inform policies to support the well-being of students as schools begin to reopen."

Among 350,000 families invited to participate, 32,217 caregivers completed the survey on behalf of nearly 50,000 children in prekindergarten through 12th grade. The survey was distributed from June 24 to July 15, 2020.

While COVID-19 related stressors were experienced by nearly all families in the survey, Black and Latinx participants experienced significantly more of these stressors. Increased exposure to COVID-19 related stressors was associated with poorer psychological well-being for children in the sample.

"The pandemic revealed to all what we've long known is true: schools are important community hubs that meet fundamental needs like access to food, health and mental health supports and services, as well as other kinds of protection," said co-senior author Kenneth Fox, MD, from the Chicago Public Schools. "While schools continue to meet those needs, we think they will also serve as sites of community healing where public health strategies and systems can converge and align to serve families in innovative ways. This convergence may be a powerful way to address the increased mental health needs the pandemic has wrought among our students, especially those from Black and Latinx communities, to ensure equitable access to support and care."

"These findings also present an important opportunity for collaboration across schools, community organizations, and academic institutions to address the important emotional needs of students," said co-senior author Ruchi Gupta, MD, MPH, Director of the Center for Food Allergy & Asthma Research (CFAAR) at Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago. "With the ongoing impact of the COVID-19 pandemic, we look forward to working together to develop programs, resources, and interventions to support these needs."

Credit: 
Ann & Robert H. Lurie Children's Hospital of Chicago

Study: ISCHEMIA trial represents small fraction of patients undergoing intervention

WASHINGTON, D.C. (APRIL 29, 2021) - Results from a new study find a broad range of patients who typically undergo revascularization for stable ischemic heart disease (SIHD) in the U.S. did not meet enrollment criteria for the ISCHEMIA trial. The data, which was presented today as late-breaking clinical science at the Society for Cardiovascular Angiography & Interventions (SCAI) 2021 Scientific Sessions, demonstrates a minority of SIHD patients referred for coronary intervention in contemporary practice clearly resemble those enrolled in the ISCHEMIA trial.

Ischemic heart disease impacts more than 13 million people in the United States and is the leading cause of death and disability worldwide. Treatment for ischemia includes a variety of medical therapies as well as procedures like percutaneous coronary intervention (PCI) to open up clogged arteries and improve blood flow to the heart. The 2020 ISCHEMIA trial, which found the procedure strategy did not decrease the risk of death or heart attack compared with medical therapy alone, was widely reported and called the practice of coronary intervention and revascularization into question. The purpose of the current study was to uncover the proportion of patients undergoing PCI in the U.S. that fell into ISCHEMIA inclusion criteria.

"The ISCHEMIA trial is one of the most important studies in interventional cardiology over the last decade. While the findings are very valuable in informing our decision-making in many patients - the population enrolled does not appear representative of the broad range of patients that modern US coronary interventionists encounter," said study senior author Jay Giri, MD, MPH, Penn Medicine.

A cross-sectional analysis of the National Cardiovascular Data Registry (NCDR) CathPCI Registry was conducted between October 2017- June 2019 (an interval representative, and inclusive of the time the ISCHEMIA trial was conducted) including more than 1,600 hospitals and 388,212 patients. Participants included patients undergoing PCI for SIHD in routine clinical practice. This SIHD population represented 42.9% of all performed PCI over the examined time period, with the majority of US PCI performed in patients with acute coronary syndromes, cardiac arrest, or cardiogenic shock. Patients who met ISCHEMIA trial inclusion criteria (SIHD, moderate to severe ischemia on functional testing, lack of high-risk anatomic or clinical features) and those who did not, were identified.

Among U.S. patients undergoing PCI for SIHD between October 2017 - June 2019, 32.3% met ISCHEMIA trial enrollment criteria. Among SIHD patients that did not meet criteria, 18.5% had SIHD with high-risk features (35.2% left main disease, 43.7% left ventricular systolic dysfunction, 16.8% end-stage renal disease), 17.3% had SIHD with negative or low-risk functional testing, and 31.9% either had no stress testing or did not have ischemic burden reported. Compared with the other SIHD cohorts, the ISCHEMIA-like cohort had the lowest in-hospital mortality rate (0.1%), and comparable in-hospital bleeding (0.6%), and acute kidney injury requiring hemodialysis (0.04%).

"Our study reveals that most patients who have intervention are not reflected in the ISCHEMIA trial," said Saurav Chatterjee, MD, principal investigator, cardiologist at Northwell Health. "These results help shine a light into what is truly happening in Cath labs across the country, and the kinds of patients who are being referred for intervention."

The full manuscript is under review.

Credit: 
Society for Cardiovascular Angiography and Interventions

Creation without contact in the collisions of lead and gold nuclei

image: Semicentral or central collisions of lead nuclei in the LHC produce quark-gluon plasma and a cocktail with contributions of other particles. Simultaneously, clouds of photons surrounding the nuclei collide, resulting in the creation of lepton-antilepton pairs within the plasma and cocktail, and in the space around the nuclei.

Image: 
Source: IFJ PAN

When heavy ions, accelerated to the speed of light, collide with each other in the depths of European or American accelerators, quark-gluon plasma is formed for fractions of a second, or even its "cocktail" seasoned with other particles. According to scientists from the IFJ PAN, experimental data show that there are underestimated actors on the scene: photons. Their collisions lead to the emission of seemingly excess particles, the presence of which could not be explained.

Quark-gluon plasma is undoubtedly the most exotic state of matter thus far known to us. In the LHC at CERN near Geneva, it is formed during central collisions of two lead ions approaching each other from opposite directions, travelling at velocities very close to that of light. This quark-gluon soup is also sometimes seasoned with other particles. Unfortunately, the theoretical description of the course of events involving plasma and a cocktail of other sources fails to describe the data collected in the experiments. In an article published in Physics Letters B, a group of scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences in Cracow explained the reason for the observed discrepancies. Data collected during collisions of lead nuclei in the LHC, as well as during collisions of gold nuclei in the RHIC at Brookhaven National Laboratory near New York, begin to agree with the theory when the description of the processes takes into account collisions between photons surrounding both interacting ions.

"With a pinch of salt, you could say that with sufficiently high energies, massive ions collide not only with their protons and neutrons, but even with their photon clouds," says Dr. Mariola Klusek-Gawenda (IFJ PAN) and immediately clarifies: "When describing the collision of ions in the LHC we already took into account collisions between photons. However, they concerned only ultra-peripheral collisions, in which the ions do not hit each other, but pass by each other unchanged, interacting only with their own electromagnetic fields. No one thought that photon collisions could play any role in violent interactions where protons and neutrons merge into a quark-gluon soup."

In conditions known from everyday life, photons do not collide with each other. However, when we are dealing with massive ions accelerated to almost the speed of light, the situation changes. The gold nucleus contains 79 protons, the lead nucleus as many as 82, so the electric charge of each ion is correspondingly many times greater than the elementary charge. The carriers of electromagnetic interactions are photons, so each ion can be treated as an object surrounded by a cloud of many photons. Moreover, in the RHIC and LHC, the ions move at speeds close to that of light. As a result, from the point of view of the observer in the laboratory, both they and their surrounding clouds of photons appear to be extremely thin patches, flattened in the direction of movement. With each passage of such a proton-neutron pancake, there is an extremely violent oscillation of the electric and magnetic fields.

In quantum electrodynamics, the theory used to describe electromagnetism with regard to quantum phenomena, there is a maximum critical value of the electric field, of the order of ten to sixteen volts per centimetre. It applies to static electric fields. In the case of collisions of massive atomic nuclei in the RHIC or LHC, we are dealing with dynamic fields appearing only for millionths of a billionth of one billionth of a second. For such an extremely short time, the electric fields in the collisions of ions can be even 100 times stronger than the critical value.

"In fact, the electric fields of ions colliding in the LHC or RHIC are so powerful that they generate virtual photons and their collisions occur. As a result of these processes, lepton-antilepton pairs are formed at various points around the ions where there was nothing material before. The particles of each pair move away from each other in a characteristic way: typically in opposite directions and almost perpendicular to the original direction of the movement of the ions," explains Dr. Wolfgang Schäfer (IFJ PAN) and points out that the family of leptons includes electrons and their more massive counterparts: muons and tauons.

Photon interactions and the production of lepton-antilepton pairs associated with them are crucial in peripheral collisions. Collisions such as these were described by the physicists from Cracow a few years ago. To their surprise, they have now managed to show that the same phenomena also play a significant role in direct collisions of nuclei, even central ones. The data collected for gold nuclei in the RHIC and lead nuclei in the LHC show that during such collisions a certain "excess" number of electron-positron pairs appears, which diverge relatively slowly in directions almost perpendicular to the ion beams. It has been possible to explain their existence precisely just by taking into account the production of lepton-antilepton pairs by colliding photons.

"The real icing on the cake for us was the fact that by supplementing the existing tools for the description of massive ion collisions with our formalism built on the so-called Wigner distribution function, we could finally explain why the detectors of the largest contemporary accelerator experiments record these sorts of distributions of leptons and antileptons escaping from the site of the nuclear collisions (for a determined centrality of the collision). Our understanding of the most important processes taking place here has become more complete," concludes Prof. Antoni Szczurek (IFJ PAN).

Work on the Cracow model of photon-photon collisions was financed by the Polish National Science Centre. The model has aroused the interest of physicists working with the ATLAS and ALICE detectors of the LHC and will be used in the next analyses of experimental data.

The Henryk Niewodniczanski Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Kraków Research Consortium: "Matter-Energy-Future", which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. The Institute holds A+ Category (the highest scientific category in Poland) in the field of sciences and engineering.

Credit: 
The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences