Tag: 24/1/23

Categories : Paediatrics Respiratory DiseasesTags : Leave a comment

More Physical Activity Linked to Fewer Respiratory Infections in Children

On By ModernMedia
Boys running
Photo by Margaret Weir on Unsplash

A study of 104 children wearing pedometers to monitor daily activity showed that higher levels of physical activity are associated with reduced susceptibility to upper respiratory tract infections such as the common cold. Reporting the findings in Pediatric Research, the researchers suggest reduced inflammatory cytokines and improved immune responses as a possible mechanism.

Wojciech Feleszko, Katarzyna Ostrzyżek-Przeździecka and colleagues measured the physical activity levels and symptoms of upper respiratory tract infections of children aged between four and seven years in the Warsaw city region between 2018 and 2019. Participants wore a pedometer armband 24 hours a day for 40 days to measure their activity levels and sleep duration. For 60 days, parents used daily questionnaires to report their children’s symptoms of upper respiratory tract infections, such as coughing or sneezing. On a second questionnaire, parents reported their children’s vaccinations, participation in sport, whether they had siblings, and their exposure to smoking and pet hair.

The authors found that as the average daily number of steps taken by children throughout the study period increased by 1000, the number of days that they experienced symptoms of upper respiratory tract infections decreased by an average of 4.1 days. Additionally, children participating in three or more hours of sport per week tended to experience fewer days with respiratory tract infection symptoms than those not regularly participating in sports.

Higher activity levels at the beginning of the study were associated with fewer days with respiratory tract infection symptoms during the following six weeks. Among 47 children, with 5668 average daily steps during the first two weeks of the study period, the combined number of days during the following six weeks that these children experienced upper respiratory tract infection symptoms was 947. However, among 47 children whose initial average daily steps numbered 9368, the combined number of days during the following six weeks that these children experienced respiratory symptoms for was 724. Upper respiratory tract infection symptoms were not associated with sleep duration, siblings, vaccinations, or exposure to pet hair or smoking.

The authors speculate that higher physical activity levels could help reduce infection risk in children by reducing levels of inflammatory cytokines and by promoting immune responses involving T-helper cells. They also suggest that skeletal muscles could release small extracellular vesicles that modulate immune responses following exercise. However, they caution that future research is needed to investigate these potential mechanisms in children. In addition, since this was an observational study, causality could not be established.

Source: EurekAlert!

Categories : COVIDTags : Leave a comment

Hybrid Immunity Offers Greatest Protection against COVID

On By ModernMedia
Image of a syring for vaccination
Photo by Mika Baumeister on Unsplash

Analysing data from controlled studies throughout the world, researchers discovered that people with hybrid immunity – from both full vaccination and prior infection – are the most protected against severe illness and reinfection. The study, published in The Lancet Infectious Diseases, will aid public policy-makers in planning the optimal timing of vaccinations.

Researchers from University of Calgary teamed up with World Health Organization (WHO) experts to answer the question of how well protected people are from combinations of vaccinations, boosters and prior infection.

“The results reinforce the global imperative for vaccination,” says Dr Niklas Bobrovitz, first author on the study. “A common question throughout the pandemic was whether previously infected people should also get vaccinated. Our results clearly indicate the need for vaccination, even among people that have had COVID.”

The global emergence and rapid spread of the Omicron variant required scientists and policy-makers to reassess population protection against Omicron infection and severe disease. In the study, investigators were able to look at immune protection against Omicron after a prior SARS-CoV-2 infection, vaccination or hybrid immunity.

“Protection against hospitalisation and severe disease remained above 95 per cent for 12 months for individuals with hybrid immunity,” says Dr Lorenzo Subissi, PhD, a technical officer with WHO and senior author on the study. “We know more variants are going to emerge. The study shows, to reduce infection waves, vaccinations could be timed for rollout just prior to expected periods of higher infection spread, such as the winter season.”

The systematic review and meta-analysis found that protection against Omicron infection declines substantially by 12 months, regardless of prior infection, vaccinations or both, which means vaccination is the best way to periodically boost protection and to keep down levels of infection in the population. In total, 4268 articles were screened and 895 underwent full-text review – a difficult task before the assistance of experts in health informatics.

“This study demonstrates the power of machine translation. We were able to break through language barriers; most of the time, systematic reviews aren’t done in every language, they are limited to one or two,” says Dr Tyler Williamson “These former BHSc classmates, along with the large diverse team they brought together, have emerged as global leaders in SARS-CoV-2 research and delivered decision-grade evidence to the world.”

While the findings demonstrate that vaccination along with a prior infection carries the most protection, the scientists warn against intentional exposure to the virus.

“You should never try to get COVID,” says Bobrovitz. “The virus is unpredictable in how it will affect your system. For some, it can be fatal or send you to hospital. Even if you have a mild infection, you risk developing long COVID.”

The group says the next phase of this research would be to investigate how the bivalent vaccine performs against severe disease.

Findings from the study complement data on the SeroTracker dashboard which monitors studies and news reports to track seroprevalence data – the percentage of people in a population who have antibodies against the novel coronavirus. The website aggregates serology data from studies and news reports in different populations, and built-in filters allow users to compare seroprevalence levels between countries, occupations, and demographic groups.

Source: University of Calgary

Categories : COVIDTags : Leave a comment

How SARS-CoV-2 Evolved Past its Own Weaknesses

On By ModernMedia
Image from Pixabay

New research suggests that the first pandemic-accelerating mutation in the SARS-CoV-2 virus evolved as a way to correct vulnerabilities that were caused by the mutation that started the SARS-CoV-2 pandemic.

Published in Science Advances, this new evidence addresses important biological questions about two key mutations in the virus’ surface spike protein, say the researchers. It suggests that a spike protein mutation called D614G, which emerged a few months after the virus began spread among humans, was not an adaptation to humans. Instead, the mutation was an adaptation to the major changes that happened in the spike gene just before the pandemic, changes which allowed spread via respiratory transmission.

“This study has revealed that the first two genetic alterations in the evolution of the spike protein in SARS-CoV-2 are connected by their function, and this knowledge can improve our understanding of how the spike protein works and how the virus evolves, with important implications for vaccine design and effectiveness of COVID antibodies,” says Stephen Gould, professor of biological chemistry at the Johns Hopkins University School of Medicine, whose lab was studying the basic biology of the virus’s spike protein when the study began.

The initial mutation in the virus, Gould says, is known by scientists as the “furin cleavage site insertion mutation.”

Research by other scientists across the world has shown that this mutation enabled the virus’s spike protein to be cut and primed it for rapid infection of cells lining the airway.

While this initial mutation was essential in helping SARS-CoV-2 efficiently slip into human cells, the mutation’s effects weren’t all good, says Gould, as it cut the spike protein structure into two separate pieces.

According to Gould, this change disrupted other functions of the spike protein, creating evolutionary pressure for a second mutation to correct the disrupted functions of the spike protein while keeping the initial mutations’ rapid infection benefits .

In early 2020, researchers from the University of Toronto discovered a subsequent SARS-CoV-2 mutation, called D614G; however, its precise function was not known.

Gould, first author and graduate student Chenxu Guo, and the research team set out to understand the D614G mutation and its effect.

Working with dozens of blood samples from patients with COVID-19 hospitalized in April 2020 at the Johns Hopkins Hospital, Gould’s team isolated antibodies for the spike protein from the patients’ blood samples. Then, they used these antibodies to track the location of spike proteins in human cells genetically engineered to produce the spiky surface molecules.

They found that the D614G mutation redirects the spike protein and pulls the virus from the surface of human cells into a tiny compartment within the cell called a lysosome, which the spike protein reprograms into storage containers that are used to release infectious virus particles from the cell.

In addition, the D614G mutation caused a three-fold drop in the abundance of spike proteins at the cell surface.

“With less spike protein on the surface of virus-infected cells, it may be more difficult for the immune system to identify and kill those virus-containing cells,” says Gould.

The researchers caution that the study does not provide information about the still-debated origins of the virus. However, their work suggests that the two mutations likely arose in rapid succession.

The researchers are new examining whether spike protein mutations in more recent virus strains affect spike protein trafficking, studying the identity of the human proteins that deliver spike proteins to lysosomes, and researching how spike proteins convert lysosomes into compartments that release more virus.

Source: John Hopkins Medicine

Categories : Cardiovascular Disease Expert OpinionTags : Leave a comment

Consider More People with PE for Surgery, AHA Statement Urges

On By ModernMedia
Credit: American Heart Association

A new American Heart Association scientific statement suggests surgery be considered for more people with high-risk pulmonary embolism (PE). The statement, published in the journal Circulation, also calls for data quality registries for high-risk patients with pulmonary embolism and more research to better understand the disease process and effective treatments.

Nearly 45% of patients experiencing PE will progress to severe symptoms, where the clot causes high pressure in the lungs and subsequent damage to the right heart chamber, with a high risk of death. Even therapy following current guideline-directed treatment has a high rate of death, estimated at approximately 40% of cases in some groups.

Treatment options for patients with severe pulmonary embolism include anticoagulation therapy or thrombolysis (either intravenously or via catheter procedure), or advanced surgical interventions such as surgical embolectomy and mechanical circulatory support. Often, surgical techniques are a last resort after other treatments are unsuccessful. The statement suggests that considering surgery earlier may help improve survival for patients with severe PE.

“This statement demonstrates that modern surgical management strategies and mechanical circulatory support results in excellent survival (97%) even among the sickest patients, including those who present with cardiac arrest and have had CPR,” said Joshua B. Goldberg, MD, chair of the statement writing group. 

“Modern surgical strategies and mechanical circulatory support are drastically underutilised,” he said. “It is the hope of the multidisciplinary group of authors that this scientific statement will provide a greater awareness of the safety and efficacy of modern surgical management and mechanical circulatory support in treating the most unstable patients so that lives may be saved. In addition, we hope this statement will facilitate improved understanding of the disease process and effective treatments and encourage future research to improve the survival of patients with this common and deadly disease.”  

The writing group proposes strategies to determine risk more accurately and identify earlier which PE patients may benefit from surgical intervention. They also suggest increased education for clinicians to encourage the use and integration of surgical strategies earlier in PE treatment. Additionally, the statement supports the development of patient registries, particularly focused on data that provides useful context for clinicians and surgeons to understand the progression from intermediate to high-risk pulmonary embolism and treatment outcomes across patients at various risk levels.

Source: American Heart Association