Month: March 2021

Impact of French Nuclear Testing Underestimated

A new report has found that the extent of radiation exposure to people involved in nuclear testing in French Polynesia has been significantly underestimated.

Over 1966 to 1996 at Moruroa and Fangataufa atolls in French Polynesia, France conducted An unofficial report has gone through thousands of recently declassified documents, focusing on the impact of three key nuclear tests: Aldébaran, Encelade and Centaure in 1966, 1971 and 1974.
The report suggests that the French government has underestimated fallout by as much as 40%, opening the door for tens of thousands more to claim compensation.

One millisievert (mSv) per annum is the maximum allowable public exposure. There is clear evidence for radiation effects at doses over 100mSv, while doses less than 10mSv are undetectable even in very large epidemiological studies and such low dose effects on human health are controversial. According to the linear-no dose-threshold (LNT) theory, all radiation exposure carries some level of harm.

Last February, a report was sent from Paris to French Polynesia on a cluster of cancers uncovered there, believed to be linked to radiation exposure . Email evidence suggests that at least 2000 of the 6000 military personnel involved in the tests had contracted at least one form of cancer.
It was only in 2010 that France established a compensation claims board for people with one of 23 cancers associated with radiation and who lived in French Polynesia at the time of the tests. However, many claimants do not have the means to access these claims, such as those who live on remote islands.

Faulty and imprecise monitoring equipment impacted the results, which were used to calculate the original dose calculations. The researchers recalculated the estimated doses absorbed by the population based on samples taken by the military at the time, and also using new methods involving meteorological data to plot the spread of radioactive fallout. Some recalculations did not show much change, but a 1966 test produced a level three times higher than the official estimate. Some 11 000 people exposed to the nuclear testing received a dose higher than 5mSv, the researchers found.

Source: The Guardian

New Smart Speakers That Can Remotely Monitor Heartbeat


Smart speaker services like Amazon’s Alexa have shown that they can be adapted to monitor the breathing of babies, and recent development has enabled them to detect heartbeats without contacting the skin.

“Heart rhythm disorders are actually more common than some other well-known heart conditions. Cardiac arrhythmias can cause major morbidities such as strokes, but can be highly unpredictable in occurrence, and thus difficult to diagnose,” explained co-senior author Dr Arun Sridhar, assistant professor of cardiology at the UW School of Medicine. “Availability of a low-cost test that can be performed frequently and at the convenience of home can be a game-changer for certain patients in terms of early diagnosis and management.”

Instead of listening to the heartbeat, the smart speaker emits a continuous sound which bounces off the patient’s body. Changes in the received sound are associated with motions in the body from a heartbeat.
“The motion from someone’s breathing is orders of magnitude larger on the chest wall than the motion from heartbeats, so that poses a pretty big challenge,” said lead author Anran Wang, a doctoral student in the Allen School. “And the breathing signal is not regular so it’s hard to simply filter it out. Using the fact that smart speakers have multiple microphones, we designed a new beam-forming algorithm to help the speakers find heartbeats.”

Beam-forming is a technology where an array of emitters or receivers can change the direction in which a signal is emitted or received. Applications of such technology include directing sound only in one direction, such as a person watching TV while another wants quiet while they read,
Much in the way AI systems sort out sounds to identify human speech, the algorithm developed by the team can pick up heartbeats. As this does not produce the usual peaks seen in heartbeat monitors, this also requires processing the heartbeat further to extract the inter-beat interval.
“With this method, we are not getting the electric signal of the heart contracting. Instead we’re seeing the vibrations on the skin when the heart beats,” Mr Wang said.

The researchers tested their prototype smart speaker system on 26 healthy participants and 24 patients with hospitalised with a variety of cardiac conditions. The team compared the smart speaker’s inter-beat interval with one from a standard heartbeat monitor. Of the nearly  2,300 heartbeats measured for the healthy participants, the smart speaker’s median inter-beat interval was within 28 milliseconds of the standard monitor. With cardiac patients, the median inter-beat interval measured by the smart speaker was within 30 milliseconds of the standard.

The technology is currently set up for spot checks; a person concerned about their heart rhythm could sit in front of a smart speaker for a reading. In the future, the researchers hope that the system could be set up to monitor heartbeats for long periods, such as when they are sleeping, helping to diagnose conditions like sleep apnoea.

Source: Medical Xpress

Restaurants and Not Wearing Masks Increases COVID Transmission, CDC Warns

Fully opening restaurants and not having mask rules in place and the Centers for Disease Control (CDC) warned.

“This report is a critical reminder that with the current levels of COVID-19 in communities and the continued spread of more transmissible virus variants, which have now been detected in 48 states, strictly following prevention measures remains essential for putting an end to this pandemic,” said CDC director Rochelle Walensky, MD, at a White House COVID briefing on Friday. “It also serves as a warning about prematurely lifting these prevention measures.”

Dr Walensky’s comments may have been made with states such as Texas and Mississippi in mind, with their governors announcing that they were dropping mask mandates and allowing full reopening, including businesses such as restaurants at full capacity. Some restaurants that are still enforcing 

Research has already shown that in-person dining and lack of mask regulations contribute to the spread of COVID cases. Taking data from state and local health department websites, COVID cases and deaths were analysed at county level The team compared data from post-implementation time points, ranging from 1-20 days to 81-100 days, to pre-implementation periods.

The researchers also attempted to control for other factors, such as restaurant closures during the mask mandates, mask mandates in the restaurant reopening models, stay-at-home orders, and bans on gatherings of more than 10 people.

Of the three-quarters of surveyed counties with mask mandates, the researchers found that within 1-20 days of mask mandates, there was a 0.5 percentage point drop in COVID case growth rates. Case and death growth rates saw almost a 2.0 percentage point decline 81-100 days after mask mandates came into effect.

Conversely, states allowed restaurants to re-open for in-person dining. While the impact was not immediate, COVID case growth rates increased 1.1 percentage points 81-100 days later. However, counties allowing in-person dining were associated with 2.2 percentage point increases at days 61-80 and a 3.0 percentage point increase at days 81-100 after restrictions were lifted.

The researchers speculated about the cause, such as restaurants potentially delaying reopening even after they were allowed to do so, and that patrons might have been more cautious during initial reopenings but more likely to dine at restaurants as time passed.

Source: MedPage Today

Review Finds Antidepressants Are Ineffective for Low Back Pain

A systematic review of studies on antidepressants for low back pain has shown that they are no more effective than placebo, but still could have even more serious side effects. 

Explaining the study, lead author Michael Ferraro, doctoral candidate at University of New South Wales (UNSW) Medicine & Health and Neuroscience Research Australia (NeuRA), said:  “Antidepressants are commonly prescribed to treat the symptoms of low back pain. However, prescription rates for antidepressants to manage low back pain are increasing worldwide, despite unclear evidence to support their efficacy and safety and conflicting advice in clinical guidelines.”

Across 17 studies with over 2500 participants, the researchers looked at differences in outcomes for pain, safety, function and depressive symptoms between people taking antidepressants and placebos. 

“We found that treating low back pain with antidepressants failed to lead to reductions in what patients might consider important benefits for pain or function,” Mr Ferraro said.

“We also discovered that people taking antidepressants for low back pain are more likely to stop treatment and experience side effects and might even experience more serious side effects.
“If people are taking antidepressants for low back pain and have any concerns about their treatment, they should consult their medical physician for advice.”

These results bring into question no less than six international guidelines that recommend the use of antidepressants for low back pain. In particular, the US has a guideline for duloxetine, a serotonin and norepinephrine reuptake inhibitor, chronic low back pain treatment.
“We believe the US recommendation for duloxetine could be reconsidered in light of our findings,” he said. “Ongoing recommendations for the use of antidepressants to treat low back pain are concerning, particularly given the increased risk of side effects.”

The low quality of the studies in general limited their findings, but no clear benefits of using antidepressants for low back pain could be identified.
“It is difficult to estimate the true effects of such medicines being used to treat low back pain. The majority of the studies were considered to be at high risk of bias and interestingly, the studies which showed the most promise were industry-sponsored. We recommend future research focuses on other types of medicines that may provide benefit to adults with low back pain, as well as non-pharmacological treatments, such as physiotherapy and exercise,” said Mr Ferraro.

Source: News-Medical.Net

Journal information: Ferraro, M.C., et al. (2021) Efficacy, acceptability, and safety of antidepressants for low back pain: a systematic review and meta-analysis. Systematic Reviews. doi.org/10.1186/s13643-021-01599-4.

Central Retinal Artery Occlusion Needs to be Treated as A Stroke

The American Heart Association published a new scientific statement, “Management of Central Retinal Artery Occlusion,” which laid out the best methods to treat what is effectively a small stroke in the eye.

A central retinal artery occlusion (CRAO) is a rare (1 in 100 000 people) form of acute ischaemic stroke arising from a blockage of blood flow to the main artery of the eye. It causes painless, immediate vision loss in the impacted eye from which less than 20% of people will recover from.

“Central retinal artery occlusion is a cardiovascular problem disguised as an eye problem. It is less common than stroke affecting the brain but is a critical sign of ill health and requires immediate medical attention,” said the chair of the statement writing committee Brian C Mac Grory, MBBCh, BAO, MRCP, an assistant professor of neurology and staff neurologist at the Duke Comprehensive Stroke Center at Duke University School of Medicine. “Unfortunately, a CRAO is a warning sign of other vascular issues, so ongoing follow-up is critical to prevent a future stroke or heart attack.”

In a comprehensive review of the literature, committee members from a variety of specialties summarised the state of the science in this condition. They noted that a lack of clinical trials results in physicians not recognising the problem, including that it is a type of stroke, resulting in inaction and differing methods of diagnosis and treatment.

“We know acute CRAO is a medical emergency requiring early recognition and triage to emergency medical treatment,” said Dr Mac Grory. “There is a narrow time window for effective treatment of CRAO and a high rate of serious related illness. So, if a person is diagnosed in a doctor’s office or another outpatient clinic, they should be immediately sent to a hospital emergency department for further evaluation and treatment.”

CRAOs can be caused by problems with carotid arteries, the blood vessels in the neck, but there is also evidence CRAOs could be caused by heart problems such as atrial fibrillation.

CRAO risk factors include age and the presence of cardiovascular risk factors such as type 2 diabetes, smoking, and obesity. 

Currently, the literature suggests that intravenous tissue plasminogen activator (tPA) treatment, a “clot buster” also used for brain strokes, could be effective. However, to be effective and safe tPA must be administered within 4.5 hours of the onset of symptoms

Hyperbaric oxygen and intra-arterial alteplase, were also noted as showing potential but requiring further study. Hyperbaric oxygen can result in an improvement if done within 24 hours of the CRAO event. Other possible treatments needing further research icnclude breaking up clots with novel thrombolytics and using novel neuroprotectants (substances capable of preserving brain function and structure) in concert with other treatments to restore blood flow in the blocked artery.

Since there is potential for future strokes or even heart attacks, patients should undergo screening and treatment of vascular risk factors as a matter of urgency. CRAOs are complex to treat and manage, requiring the joint effort of a team of specialists.

Secondary prevention (including monitoring for complications) must be a collaborative effort between neurologists, ophthalmologists, cardiologists and primary care clinicians. Risk factor modification includes lifestyle and pharmacological interventions.

Source: News-Medical.Net

Journal information: Grory, B. M., et al. (2021) Management of Central Retinal Artery Occlusion: A Scientific Statement From the American Heart Association. Stroke. doi.org/10.1161/STR.0000000000000366.

Molnupiravir Performs Well Versus COVID in Early Trials

Pharmaceutical giant announced on Saturday that its antiviral drug molnupiravir significantly reduced viral load in COVID patients.

Delivering the information to infectious disease experts, the company said that the drug caused the drop in viral loads five days after administration to COVID patients.

“At a time where there is unmet need for antiviral treatments against SARS-CoV-2, we are encouraged by these preliminary data,” said Wendy Painter, chief medical officer of the US firm, Ridgeback Biotherapeutics, which developed the drug in concert with Merck.

Merck had stopped development of two vaccine candidates earlier on, but has been pressing ahead with two possible treatments for COVID.

The experimental drug, also known as EIDD-2801, is currently in its Phase 2a trials. It would need to complete the third phase trials to gain approval. Molnupiravir was originally developed to treat influenza viruses, and its mechanism of action is thought to be through inducing RNA transcription errors in viruses, leading to a transcription catastrophe. This mechanism also inherently creates a significant barrier for viral escape from the drug.

The clinical trials enrolled 202 participants with COVID, who were not hospitalised. There were no safety alerts for the drug, and the four serious adverse events that did occur were not considered to be associated with the drug, Ms Painter said.

William Fischer, lead investigator of the study and a professor of medicine at the University of North Carolina said that these were promising results, adding: “If supported by additional studies, (they) could have important public health implications, particularly as the SARS-CoV-2 virus continues to spread and evolve globally.”

The company is testing another drug in clinical trials, MK-711, preliminary results for which have indicated a 50% drop in viral load in mild and severe COVID patients.

Source: Medical Xpress

UK Says ‘Strong Evidence’ of Gender Health Gap Exists

Woman in a hospital bed. Photo by Andrea Piacquadio from Pexels.

As an inquiry into the disparity of health service provision to women begins this week, Ministers in the UK say there is “strong evidence” of a gender gap.

The Women’s Health Strategy will speak to women and girls over the next 12 weeks on a variety of issues, ranging from maternity care to mental health.

Nadine Dorries, minister for women’s health, said: “Women’s experiences of healthcare can vary and we want to ensure women are able to access the treatment and services they need.

“It’s crucial women’s voices are at the front and centre of this strategy so we understand their experiences and how to improve their outcomes.”

Patients have told the BBC they have felt overlooked in conditions like endometriosis, or procedures such a pelvic floor mesh.

There is less knowledge on female conditions and their treatment among clinicians. Despite the fact that they make up half of the population, female conditions are often considered a ‘niche’ area. Research shows that a large part of the problem is due to the fact that clinical trials have  failed to take into account gender. Eight out of ten drugs that were withdrawn in the US between 1997 and 2000 were as a result of side effects in women.
While campaigners have welcomed the view, they say that it is still vital to listen to women’s views and act on them.

Gill Walton, chief executive of the Royal College of Midwives, said: “We know that placing women at the centre of their own care not only improves outcomes in pregnancy, but also improves a woman’s experience of birth and maternity care.”

Mika Simmons, co-chair of the Ginsburg Women’s Health Board, filmmaker, and host of The Happy Vagina podcast, said: “Every single woman I speak to, myself included, has experienced either misunderstanding or loss as a direct result of slow or inaccurate diagnosis of their health concerns.

“I am delighted that this – the gender health gap – which grew out of a severe lack of historical research into women’s health issues, is not only finally being acknowledged but that steps are being taken to right size it.”

Source: BBC News

Faster 3-D Bioprinting A Step Closer to Printing Whole Organs

With the demonstration of a new type of more rapid 3-D bioprinting, University at Buffalo engineers have taken a step closer to the fabrication of whole organs.

In a video of the process, a hand emerges over a matter of seconds from a vat of liquid almost as if out of a science fiction movie. In reality, the video was sped up from its original duration of 19 minutes, but even this is a quantum leap ahead of the six or so hours such a process previously took. 
“The technology we’ve developed is 10-50 times faster than the industry standard, and it works with large sample sizes that have been very difficult to achieve previously,” said co-lead author Ruogang Zhao, PhD, associate professor of biomedical engineering.

The new method involves a 3-D printing technology called stereolithography and hydrogels. Hydrogels have applications in wound dressings, contact lenses and hygiene products, as well as scaffolds for tissue engineering.

Scaffolds are particularly important in 3-D bioprinting, and the team has spent a great deal of its time and effort on these in order to come up with an optimised solution for its fast, accurate 3-D printing technique.
“Our method allows for the rapid printing of centimeter-sized hydrogel models. It significantly reduces part deformation and cellular injuries caused by the prolonged exposure to the environmental stresses you commonly see in conventional 3-D printing methods,” said the other co-lead author, Chi Zhou, PhD, associate professor of industrial and systems engineering.

This method is readily suited for the printing of cells with embedded networks of blood vessels. It is expected that this emerging technology will be key to producing whole 3-D printed organs and tissue.

Source: Medical Xpress

Journal information: Nanditha Anandakrishnan et al, Fast Stereolithography Printing of Large‐Scale Biocompatible Hydrogel Models, Advanced Healthcare Materials (2021). DOI: 10.1002/adhm.202002103
https://medicalxpress.com/news/2021-03-rapid-3d-method-3d-printed.html

‘Obesity Paradox’ in Kidney Cancer Continues to Mystify

Obese patients with metastatic renal cell carcinoma (RCC) were more likely to survive compared to their normal weight counterparts when receiving immune checkpoint inhibitors (ICI), a study has shown.

RCC is the most deadly of the urogenital cancers, and its incidence is increasing. Males are twice as likely as females to develop it.
A team of researchers including Toni Choueiri, MD, of Dana-Farber Cancer Institute in Boston, conducted an analysis of 735 metastatic RCC patients who received PD-1/L1 immunotherapies. 

Those with a BMI of 25 or greater had significantly longer overall survival (OS), with 1-year rates of 79% versus 66% for those with a BMI below that cutoff. This relationship was observed across tumour categories.

“These findings are consistent with the obesity paradox that was previously seen during the VEGF-targeted therapy era,” the team noted.

“Several hypotheses have attempted to explain this clinical observation in RCC,” Choueiri’s team wrote. “Low fatty acid synthase gene expression, which is inversely correlated with BMI, was associated with longer OS in VEGF-treated patients. Transcriptomic analysis suggests that patients with obesity have tumors with increased angiogenesis gene signatures and peritumoral adipose tissues with increased hypoxia, inflammation, and immune cell infiltration signatures.”

In 319 patients with next-generation sequencing technology, there was no difference between groups for tumour mutation burden, at an average 6.8 mutations per megabase for the low and high BMI groups. Genomic alteration frequency analysis also picked up no differences.

Limitations of the study authors included its retrospective nature, incomplete gene-expression profiling, and between-group imbalances. Patients with higher BMI had greater odds of having better performance status and being in more favourable risk groups, had greater odds of having clear cell histology, having had prior nephrectomy, and having received a checkpoint inhibitor as first-line therapy.

Source: MedPage Today

Journal information: AKA Lalani, et al “Assessment of immune checkpoint inhibitors and genomic alterations by body mass index in advanced renal cell carcinoma” JAMA Oncol 2021; DOI: 10.1001/jamaoncol.2021.0019.

Health Conditions Driven By Evolution and Genetic Sex Differences

A new study shows that the human genome has been subject to selection pressures favouring different characteristics in females and males, which makes males more susceptible to a variety of health conditions.

Genetic sex differences have long been known to have an impact on health. On balance, while females have certain conditions unique to them (eg, cervical cancer), or are more prone to (eg, multiple sclerosis), males are more prone to certain medical conditions, bringing down their average life expectancy compared to women.

Their research adds to a body of knowledge on genomic influences on health, which can map hereditary traits onto individuals and populations to guide healthcare. Looking at health conditions through the lens of genomics can help clinicians to better understand them and guide development of new treatments.  

“Our cells have memories and they carry the accumulation of all the changes our ancestors have experienced over millions of years,” said Rama Singh, a McMaster biology professor who wrote the paper with his son, Karun Singh, an associate professor of neuropathology at the University of Toronto, and Shiva Singh (no relation), a biology professor at Western University.

The researchers focussed on autism, which is a good example of the way men and women develop medical conditions differently; though they inherit the same sets of genes from the parents, the expression of those genes differs greatly by sex.

Though human behaviour regarding mate selection has changed, those genetic characteristics remain and continue to be expressed in the health and development of modern men.

The male genome has been shaped over millions of years, and favours reproduction in the early years of male maturity to pass on genes, at the expense of genetic well-being in the long term.

Women are less vulnerable to most health conditions, living longer than men because their genomes have evolved to protect against unhealthy traits in the male genome, resulting in better immunity and more longevity.

The same forces shaping human selection also apply to mental health, even though it is complex. Women are more prone to anxiety and depression, while men are more prone to anti-social disorders.

“If women and men were any more different, they would be different species,” joked corresponding author, Prof Karun Singh.

Male-female imbalance is especially pronounced in autism, with being up to four times more likely to have some form of autism, and are also more likely to have severe symptoms. Evolution has resulted in a higher threshold, protecting females from developing the condition.

Although autism is not solely the result of inherited characteristics, it does appear that boys are more likely to develop it as a result of other inhertied characteristics rendering them more vulnerable to environmental, developmental and other factors that give rise to autism.

“One of the reasons I think this is interesting is that it offers a perspective that is not well represented in the medical literature. This is a really good example of the perspective that geneticists and evolutionary biologists can add to health research,” said Prof Karun Singh.

Source: News-Medical.Net

Journal information: Singh, R. S., et al. (2021) Origin of Sex-Biased Mental Disorders: An Evolutionary Perspective. Journal of Molecular Evolution. doi.org/10.1007/s00239-021-09999-9.