Tag: 3/5/22

Categories : COVIDTags : Leave a comment

Omicron Sub-lineages are Evolving Increased Immune Escape Potential

On By ModernMedia
SARS-CoV-2 lineages. Credit: Professor Ryan Gregory, University of Guelph

A paper published May 1 on the medRxiv preprint server on two new sub-lineages of Omicron, BA.4 and BA.5, reported evidence that they may escape immunity conferred by previous BA.1 infection. The study’s authors suggest that this immune escape potential may drive another wave of infections.

In recent weeks, the BA.4 and BA.5 variants have been detected circulating in South Africa, and are close descendants of the Omicron BA.2 lineage.

Researchers isolated live BA.4 and BA.5 viruses and tested their ability to evade infection to 24 participants who had been infected with BA.1 but unvaccinated and 15 vaccinated participants with breakthrough BA.1 infection.

In unvaccinated individuals, FRNT50, the inverse of the dilution for 50% neutralisation, declined from 275 for BA.1 to 36 for BA.4 and 37 for BA.5, a 7.6 and 7.5-fold drop, respectively. In vaccinated BA.1 breakthroughs, FRNT50 declined from 507 for BA.1 to 158 for BA.4 (3.2-fold) and 198 for BA.5 (2.6-fold). Absolute BA.4 and BA.5 neutralisation levels were about 5-fold higher in this group versus unvaccinated BA.1 infected participants.

The observed escape of BA.4 and BA.5 from immunity elicited by BA.1 was more moderate than of BA.1 against previous immunity, the researchers found. The researchers warned that the low absolute neutralisation levels for BA.4 and BA.5, particularly in the unvaccinated group, are unlikely to protect well against symptomatic infection. They suggest that, based on neutralisation escape, BA.4 and BA.5 have potential to result in a new infection wave.

Experts warn however that even these sub-lineages are unlikely to be the last, with plenty of potential remaining for new mutations.

Professor of evolutionary biology T. Ryan Gregory at the University of Guelph, Canada, laid out in a series of tweets that these new sub-lineages are not the final “Pokemon” evolution of SARS-CoV-2. He warned that with all of the replication that is still going on, the virus is still mutating rapidly, especially around the Spike protein, and thus is capable of producing new variants.

Alpha and Delta, which drove two major waves around the world with high levels of mortality, did not give rise to Omicron, but now the variants of concern are increasingly emerging from within the Omicron clade. Prof Gregory noted that a growing number of variants are being seen with transmission or immune escape advantages.

“Sorry to say it, but this pandemic isn’t over,” he concluded.

Categories : Cardiovascular Disease ExerciseTags : Leave a comment

Cutting Down on Sedentary Time Reduces Cardiovascular Risk

On By ModernMedia
Feet in sports shoes
Source: Pixabay

Cutting down daily sedentary time can have a positive effect on the risk factors of cardiovascular disease and type 2 diabetes in as little as three months, according to a study published in the Journal of Science and Medicine in Sport. The study findings suggest that simply one hour less sitting daily and increasing light physical activity can help in the prevention of these diseases.

Regular exercise is well known to be beneficial in weight management and prevention of chronic diseases. However, many adults do not meet the weekly recommendation of 2.5 hours of moderate-intensity exercise, and the majority of the day is typically spent sitting.

In an intervention study, researchers investigated whether health benefits can be achieved by reducing daily sedentary time during a three-month intervention period. The research participants were sedentary and physically inactive working-age adults with an increased risk of type 2 diabetes and cardiovascular diseases.

The researchers compared two groups: the intervention group was guided to reduce their sitting time by one hour per day by increasing standing and light-intensity physical activity, while the control group was instructed to maintain their usual habits and sedentary lifestyle.

“What makes our research design unique is that sedentary time and physical activity of both groups were measured with accelerometers throughout the entire three-month period, whereas in earlier studies activity has typically been measured only for a few days at the beginning and end of the study period. This makes it possible to receive more information on the actual behaviour changes over a longer time period,” explained  Doctoral Candidate Taru Garthwaite from the University of Turku in Finland.

The intervention group reduced sedentary time by 50 minutes per day on average, mainly by increasing the amount of light- and moderate-intensity physical activity. Over the three-month period, the researchers observed benefits in health outcomes related to blood sugar regulation, insulin sensitivity and liver health in the intervention group.

“It is an encouraging thought that health benefits can be achieved by reducing the time spent sitting and increasing the amount of even light-intensity physical activity. For many, this may be an easier starting point than increasing actual exercise,” said Garthwaite.

People who do not meet the weekly physical activity recommendations atre the most likely to benefit the most from replacing sedentary time with light physical activity. However, reducing sedentary time is probably not enough in itself to prevent diseases if the person has several risk factors of diabetes and cardiovascular diseases.

Garthwaite stressed the encouraging nature of the findings: “Reducing the time spent sitting might still slow down the development of these diseases, but greater benefits can of course be gained by increasing the amount or intensity of physical activity in addition to sitting less.”

The researchers next aim to study how changes in daily activity and sedentary time affect energy metabolism and body composition in addition to the risk factors of diabetes and cardiovascular diseases over a six-month study period.

Source: University of Turku

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Fungal Microbiota May Explain Antibiotics’ Long Term Effects in Infants

On By ModernMedia
Gut microbiome. Credit: Darryl Leja, NIH

In infants treated with antibiotics, fungal gut microbiota are more abundant and diverse compared with the control group even six weeks following the start of the antibiotic course, according to a study published in the Journal of Fungi. The study’s authors suggest that reduced competition from gut bacteria being killed by antibiotics left more space for fungi to multiply.

“The results of our research strongly indicate that bacteria in the gut regulate the fungal microbiota and keep it under control. When bacteria are disrupted by antibiotics, fungi, Candida in particular, have the chance to reproduce,” explained PhD student Rebecka Ventin-Holmberg from the University of Helsinki.

A new key finding in the study was that the changes in the fungal gut microbiota, together with the bacterial microbiota, may be partly responsible for the long-term adverse effects of antibiotics on human health.

Antibiotics are the most commonly prescribed drugs for infants, causing changes in the gut microbiota at its most important developmental stage. These changes are more long-term compared to those in adults.

“Antibiotics can have adverse effects on both the bacterial and the fungal microbiota, which can result in, for example, antibiotic-associated diarrhoea,” Ventin-Holmberg said.

“In addition, antibiotics increase the risk of developing chronic inflammatory diseases, such as inflammatory bowel disease (IBD), and they have been found also to have a link to overweight,” she added.

These long-term effects are thought to be caused, at least in part, by an imbalance in the gut microbiota.

This study involved infants with a respiratory syncytial virus (RSV) infection who had never previously received antibiotics. While some of the children were given antibiotics due to complications, others received no antibiotic therapy throughout the study.

“Investigating the effects of antibiotics is important for the development of techniques that can be used to avoid chronic inflammatory diseases and other disruptions to the gut microbiota in the future,” Ventin-Holmberg emphasised.

While there have been many studies on the effect of antibiotics on bacterial microbiota, there has been a lack of studies on fungal microbiota. This study’s findings indicate that fungal microbiota may also have a role in the long-term effects of imbalance in the gut microbiota.

“Consequently, future research should focus on all micro-organisms in the gut together to better understand their interconnections and to obtain a better overview of the microbiome as a whole,” Ventin-Holmberg noted.

Source: University of Helsinki

Categories : Healthcare Politics and RegulationsTags : Leave a comment

US Stands Poised to Rescind Abortion Rights

On By ModernMedia
Photo by Andy Feliciotti on Unsplash

The US Supreme Court has voted to strike down the landmark Roe v Wade decision which constitutionally protects abortion rights, according to an initial draft majority opinion leaked by news outlet POLITICO. This comes at a time when abortion rights are being challenged in a number of US states, and such a ruling would cause abortion to become immediately illegal in 22 US states.

In 2019, there were 630 000 reported abortions in the US in 2019, according to the US Centers for Disease Control, an 18% decrease compared with 2010. Women in their 20s accounted for 57% of abortions in 2019. Abortions are highest among black American women, with a rate of 27 per 1000 for ages 15–44.

The Roe v Wade decision in 1973 gave women in the US an absolute right to an abortion in the first three months of pregnancy, and limited rights in the second trimester.

In 1992, in Planned Parenthood v Casey, it was ruled that states could not place an “undue burden” on women seeking abortions before a foetus could survive outside the womb, at about 24 weeks.

The draft opinion written by Justice Samuel Alito completely refutes the 1973 decision which guaranteed constitutional protections of abortion rights in the US, and also a subsequent 1992 decision – Planned Parenthood v. Casey – that largely maintained the right. “Roe was egregiously wrong from the start,” Justice Alito wrote.

“We hold that Roe and Casey must be overruled,” he writes in the document, labelled as the “Opinion of the Court.” “It is time to heed the Constitution and return the issue of abortion to the people’s elected representatives.”

In the past, deliberations on controversial cases have been fluid, with justices occasionally changing their votes as draft opinions circulate. This represents a rare breach of Supreme Court secrecy and tradition around its deliberations. The final, binding decision, is expected to be published in two months. Currently, five Republican appointees including Justice Alito have voted in favour of repealing Roe and Casey, while the three Democrat appointees are dissenting. It is not known how the last member, Chief Justice John Roberts, will vote.

The ruling as it currently stands would end the 49 year old US constitutional protection of abortion rights, instead allowing each US state to restrict or ban abortions outright.

POLITICO notes that public disclosure of a draft decision is unprecedented in the court’s modern history. Some observers had predicted that the conservative majority would have chipped away at abortion rights without overturning it.

The draft shows that the court is seeking to reject Roe’s logic and legal protections. “The inescapable conclusion is that a right to abortion is not deeply rooted in the Nation’s history and traditions,” Justice Alito wrote, declaring that one Roe’s central tenets, the “viability” distinction between foetuses not capable of surviving outside the uterus and those which can, “makes no sense.”

Justice Alito also described doctors and nurses who terminate pregnancies as “abortionists”, instead of the more neutral term “abortion providers” used by Chief Justice Roberts.

Source: Politico

Categories : Medical Research & TechnologyTags : Leave a comment

A Promising Antidote for Carbon Monoxide Poisoning

On By ModernMedia
Photo by Pablo Stanic on Unsplash

Carbon monoxide (CO) is an odourless and colourless gas is produced from incomplete burning, and is a silent killer, binding to haemoglobin with few treatments available other than administering oxygen. Now, research published in Chemical Communications suggests a path to a possible antidote.

In the US, more than 400 deaths and 20 000 emergency room visits are attributable to carbon monoxide (CO) poisoning every year. While CO detectors and making sure fireplace and heaters work correctly can help prevent exposure, there are limited treatment options for those suffering from CO poisoning.

To address this, Tim Johnstone, an assistant professor of chemistry and biochemistry at UC Santa Cruz, has been working to develop an easy-to-administer antidote.

“If you are exposed to carbon monoxide, the primary treatment right now is fresh air,” said A/Prof Johnstone. “It is a question of time. In fresh air, you need four to six hours for the level of CO in your blood to be cut in half. With 100 percent oxygen or hyperbaric oxygen, the half-life shortens further. Even then, the high blood levels of CO can persist long enough to lead to long-term deficits and neurological problems.”

A/Prof Johnstone has been studying the chemistry of carbon monoxide. In a biological context, CO binds to metal centres such as the iron in haemoglobin, preventing this protein from carrying out its oxygen carrying function.

To mitigate this, A/Prof Johnstone has designed small molecules that possess many of the features of the active site of haemoglobin but can bind CO much more tightly than the protein. In his most recent study, his group described the ability of one such molecule to bind CO, sequester CO that is already bonded to haemoglobin, and rescue red blood cells exposed to CO: all promising signs for a future antidote.

These are early results, said A/Prof Johnstone, but the hope is to create a point-of-care treatment that can be administered quickly. The most common carbon monoxide poisoning symptoms are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. Because it mimics the flu, people may experience symptoms without realizing the danger and delay seeking treatment.

Source: University of California Santa Cruz