Day: November 9, 2022

Cryoablation may be a Better First-stage Atrial Fibrillation Treatment

Photo by Piron Guillaume on Unsplash

A recent study comparing atrial fibrillation (AF) treatments, published in The New England Journal of Medicine, shows that early intervention with cryoballoon catheter ablation (cryoablation) is more effective at reducing the risk of serious long-term health impacts, when compared to the current first step in treatment, antiarrhythmic drugs.

“By treating patients with cryoablation right from the start, we see fewer people advancing to persistent, more life-threatening forms of atrial fibrillation,” says Dr Jason Andrade, an associate professor of medicine at University of British Columbia. “In the short term, this can mean less recurrences of arrhythmia, improved quality of life and fewer visits to the hospital. In the long run, this can translate into a reduced risk of stroke and other serious heart problems.”

When used for AF, cryoablation is a minimally invasive procedure that involves guiding a small tube into the heart to kill problematic tissue by freezing. Historically, the procedure has been reserved as a secondary treatment when patients don’t respond to antiarrhythmic drugs.

“This study adds to the growing body of evidence that early intervention with cryoablation may be a more effective initial therapy in the appropriate patients,” says Dr Andrade.

Early intervention halts disease progression

AF affects approximately 3% of the population, and while the condition starts as an isolated electrical disorder, each recurring incident can cause electrical and structural changes in the heart that can lead to persistent AF, where episodes last more than seven days.

“Atrial fibrillation is like a snowball rolling down a hill. With each atrial fibrillation episode there are progressive changes in the heart, and the heart rhythm problem gets worse,” explains Dr Andrade.

The new findings, stemming from a multi-site clinical trial, show that cryoablation can stop this snowball effect.

Researchers enrolled 303 patients with AF in Canada. Half of the patients were randomised to receive antiarrhythmic drugs, while the other half were treated with cryoablation. All patients received an implantable monitoring device that recorded their cardiac activity throughout the study period.

At three years follow-up, patients in the cryoablation group were less likely to progress to persistent AF compared to patients treated with antiarrhythmic drugs. Over the follow-up period, the cryoablation patients also had lower hospitalisation rates and experienced fewer serious adverse health events that resulted in death, functional disability or prolonged hospitalisation.

Addressing the root cause

Because cryoablation targets and destroys the cells that initiate and perpetuate AF, the researchers say it can lead to longer-lasting benefits.

“With cryoablation, we’re treating the cause of the condition, instead of using medications to cover-up the symptoms,” says Dr Andrade. “If we start with cryoablation, we may be able to fix atrial fibrillation early in its course.”

The new study builds on previous work by Dr Andrade and colleagues demonstrating that cryoablation was more effective than antiarrhythmic drugs at reducing the short-term recurrence of atrial fibrillation.

COVID Vaccination Boosts Nasopharyngeal Cancer Treatment Success

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Patients with nasopharyngeal cancer are often treated with immunotherapy. It was previously feared that, due to its immune response stimulation, COVID vaccination could reduce the success of cancer treatment or cause severe side effects. A recent study published as a “Letter to the editor” in the journal Annals of Oncology now gives the all-clear on this matter. What’s more, the study showed that cancer drugs actually worked better after vaccination with the Chinese vaccine SinoVac than in unvaccinated patients.

Many cancer cells are capable of subverting the body’s immune response. They do this by acting on the PD-1 receptor, they effectively shut down these endogenous defence forces. Drugs can be used to block PD-1 receptors. This enables the immune system to fight the tumour more effectively.

Vaccination against COVID also stimulates the immune response, involving the PD-1 receptor. “It was feared that the vaccine would not be compatible with anti-PD-1 therapy,” explains Dr Jian Li of the Institute of Molecular Medicine and Experimental Immunology (IMMEI) at the University Hospital Bonn. “This risk is especially true for nasopharyngeal cancer, which, like the SARS Cov-2 virus, affects the upper respiratory tract.”

Researchers from the Universities of Bonn and Shanxi in the People’s Republic of China investigated whether this concern is justified. More than 1500 patients treated in 23 hospitals from all over China participated in the analysis. Such multi-centre studies are considered to be particularly informative because the participants are very diverse and, moreover, the results are not distorted by regional characteristics.

Better response to cancer therapy

A subset of 373 affected individuals had been vaccinated with the Chinese COVID vaccine SinoVac. “Surprisingly, they responded significantly better to anti-PD-1 therapy than the unvaccinated patients,” explains Prof. Dr. Christian Kurts, Director of IMMEI. “Furthermore, they did not experience severe side effects more often.” The researchers cannot say why the treatment was more successful after vaccination. “We assume that vaccination activates certain immune cells, which then attack the tumor,” says Prof. Dr. Qi Mei of Shanxi University Hospital. “We will now investigate this hypothesis further.”

Nasopharyngeal cancer is quite rare in this country. In southern China and other countries in Southeast Asia, however, the disease is widespread. One of the suspected reasons for this is the frequent use of air conditioning in the hot and humid regions. Nutritional factors also appear to play an important role. In Taiwan, nasopharyngeal cancer is now considered one of the leading causes of death among young men.

Source: University of Bonn

Viewing Violent TV Leaves Lasting Impact on Preschool Children

Photo by Helena Lopes

Watching violent TV during the preschool years can lead to later risks of psychological and academic impairment by the end of primary school according to a new study published in the Journal of Developmental and Behavioral Pediatrics.

According to study leader Professor Linda Pagani, a professor at Université de Montréal’s School of Psycho-Education, it was previously “unclear to what extent exposure to typical violent screen content in early childhood – a particularly critical time in brain development – can predict later psychological distress and academic risks,” said Pagani.

“The detection of early modifiable factors that influence a child’s later well-being is an important target for individual and community health initiatives, and psychological adjustment and academic motivation are essential elements in the successful transition to adolescence,” she added.

“So, we wanted to see the long-term effect of typical violent screen exposure in preschoolers on normal development, based on several key indicators of youth adjustment at age 12.”

To do this, Pagani and her team examined the violent screen content that parents reported their children viewing between ages three-and-a-half and four-and-a-half, and then conducted a follow-up when the children reached 12.

Follow-up at age 12

At the follow-up, two reports were taken: first, of what teachers said they observed, and second, of what the children themselves, now at the end of Grade 6, described as their psychological and academic progress.

“Compared to their same-sex peers who were not exposed to violent screen content, boys and girls who were exposed to typical violent content on television were more likely to experience subsequent increases in emotional distress,” said Pagani.

“They also experienced decreases in classroom engagement, academic achievement and academic motivation by the end of the sixth grade,” she added.

“For youth, transition to middle school already represents a crucial stage in their development as adolescents. Feeling sadness and anxiety and being at risk academically tends to complicate their situation.”

Pagani and co-authors Jessica Bernard and Caroline Fitzpatrick came to their conclusions after examining data from a cohort of children born in 1997 or 1998 who are part of the Quebec Longitudinal Study of Child Development, coordinated by the Institut de la statistique du Québec.

Close to 2000 children studied

In all, the parents of 978 girls and 998 boys participated in the study of violent TV viewing at the preschool age. At age 12 years, the children and their teachers rated the children’s psychosocial and academic achievement, motivation and participation in classroom activities.

Pagani’s team then analysed the data to identify any significant link between problems with those aspects and violent content they were exposed to at preschool, while trying to account for as many possible biases and confounding influences as possible.

“Our goal was to eliminate any pre-existing conditions of the children or families that could have provided an alternative explanation or throw a different light on our results,” Pagani said.

Watching TV is a common early childhood pastime, and some of the children in the study were exposed to violence and some were not.

Psychological and academic impairment in children is of increasing concern for education and public-health sector workers. According to Pagani, problems starting middle school (ages 13 to 15) are rooted in early childhood.

Identifying with fictional characters

“Preschool children tend to identify with characters on TV and treat everything they see as real,” she said. “They are especially vulnerable to humorous depictions of glorified heroes and villains who use violence as a justified means to solve problems.

“Repeated exposure,” she added, “to rapidly paced, adrenaline-inducing action sequences and captivating special effects could reinforce beliefs, attitudes and impressions that habitual violence in social interactions is ‘ normal’. Mislearning essential social skills can make it difficult to fit in at school.”

Added Bernard: “Just like witnessing violence in real life, being repeatedly exposed to a hostile and violent world populated by sometimes grotesque-looking creatures could trigger fear and stress and lead these children to perceive society as dangerous and frightening.

“And this can lead to habitually overreacting in ambiguous social situations.”

She continued: “In the preschool years, the number of hours in a day is limited, and the more children get exposed to aggressive interactions (on screens) the more they might think it normal to behave that way.”

Pagani added: “Being exposed to more appropriate social situations, however, can help them develop essential social skills that will later be useful and ultimately play a key role in their personal and economic success.”

Source: University of Montreal

Why Women Have the Edge in Recovery from Kidney Injury

Anatomic model of a kidney
Photo by Robina Weermeijer on Unsplash

Women have a better ability to recover from kidney injury than men, but the reasons are not well understood. A study in Cell Reports may provide answers, as researchers found that females have an advantage at the molecular level that protects them from a newly discovered form of cell death that occurs in injured kidneys. This protection could be exploited as a potential therapeutic.

“Kidney disease afflicts more than 850 million people worldwide every year, so it’s important to understand why female kidneys are more protected from these acute and chronic injuries,” said Tomokazu Souma, MD, PhD, assistant professor at Duke University School of Medicine. “Our study is a step toward identifying the causes and suggests that this female resilience could be therapeutically harnessed to improve kidney repair in both sexes.”

Souma and colleagues conducted studies in mice focusing on a form of cell death called ferroptosis, which was only recently discovered. This form of cell death is dependent on iron and oxidative stress. It has been identified as a key player in kidney diseases.

Using genetic and single-cell RNA transcriptomic analysis in mice, the researchers found that being female confers striking protection against ferroptosis through a particular pathway called nuclear factor erythroid 2-related factor 2, or NRF2.

In females, NRF2 is highly active, keeping cell death in check. In males, however, the sex hormone testosterone reduces the activity of NRF2, thus promoting ferroptosis and undermining cell resiliency in kidney injury.

Further experiments showed that chemically activating NRF2 protected male kidney cells from ferroptosis, demonstrating that NRF2 could be a potential therapeutic target to prevent failed renal repair after acute kidney injury.

“By identifying the mechanism in which the female hormonal environment protects and the male hormonal environment aggravates acute and chronic kidney injuries, we believe there is strong potential to boost the resilience of kidneys,” Souma said.

Source: Duke University Medical Center

Hormone Discovery could Predict Longevity of Men

Old man jogging
Photo by Barbra Olsen on Pexels

Researchers have discovered that a certain hormone, that develops in males during puberty, could be predictive of the risk of developing age-related disease in later life.

The novel insulin-like peptide hormone, called INSL3, was found by researchers to be consistent over long periods of time and is an important early biomarker for prediction of age-linked disease. Their latest findings have been published today in Frontiers in Endocrinology.

INSL3 is produced in the testes by Leydig cells, which also make testosterone, but unlike testosterone which fluctuates over a man’s life, INSL3 remains consistent, with the level at puberty staying about the same throughout life, decreasing only slightly into old age. This makes it the first clear and reliable predictive biomarker of age-related morbidity as compared to any other measurable parameters.

Blood levels of INSL3 were associated with a range of age-related illnesses, such as bone weakness, sexual dysfunction, diabetes, and cardiovascular disease.

Since the hormone is so consistent, a young man with high INSL3 would still have high INSL3 when he is older. But low levels of INSL3 when young will stay low when older, making a man more likely to acquire typical age-related illnesses. This opens up exciting possibilities for predicting age-related illnesses and finding ways to prevent the onset of these diseases with early intervention.

This study from University of Nottingham was led by Professors Ravinder Anand-Ivell and Richard Ivell and is the latest of three recent studies into this hormone. Prof Anand-Ivell explains: “The holy grail of ageing research is to reduce the fitness gap that appears as people age. Understanding why some people are more likely to develop disability and disease as they age is vital so that interventions can be found to ensure people not only live a long life but also a healthy life as they age. Our hormone discovery is an important step in understanding this and will pave the way for not only helping people individually but also helping to ease the care crisis we face as a society.”

The team analysed blood samples from 3000 men, with two samples taken four years apart and found that unlike testosterone, INSL3 remains at consistent.

The study also showed that there is an almost 10-fold variation in INSL3 levels in the normal male population, even among the young and healthy.

Prof Ivell adds: “Now we know the important role this hormone plays in predicting disease and how it varies amongst men we are turning our attention to finding out what factors have the most influence on the level of INSL3 in the blood. Preliminary work suggests early life nutrition may play a role, but many other factors such as genetics or exposure to some environmental endocrine disruptors may play a part.”

Source: University of Nottingham