Day: February 21, 2022

Categories : Obstetrics & GynaecologyTags :

Endocrine-disrupting Chemicals Present in Many Pregnancies

On By ModernMedia
Photo by Shvets Productions on Pexels

Researchers in Europe have shown that up to 54% of pregnant women in Sweden were exposed to complex mixtures of endocrine-disrupting chemicals disruptive to brain development.

While current risk assessment tackles chemicals and their allowable exposures on an individual basis, these findings show the need to take mixtures into account for future risk assessment approaches. The study was published in Science.

A growing body of evidence has shown that industrially produced chemicals have endocrine disrupting properties and can thus be dangerous to human and animal health and development. A huge number of new compounds is released every year into the environment during the production of plastic derivatives and other goods.

While exposures for individual chemicals falls below thresholds, exposure to the same chemicals in complex mixtures can still impact human health. However, all current exposure thresholds, are based on chemicals being examined individually. Therefore, an alternative strategy needed to be tested, in which the actual mixtures measured in real life exposures could be tested as such in both the epidemiological and experimental setting. The EDC-MixRisk project set out to tackle this unmet need.

“The uniqueness of this comprehensive project is that we have linked population data with experimental studies, and then used this information to develop new methods for risk assessment of chemical mixtures,” said Carl-Gustaf Bornehag, professor at Karlstad University, Project Manager of the SELMA study.

The study was conducted in three steps:

  1. A mixture of chemicals in the blood and urine of pregnant women was identified in the Swedish pregnancy cohort SELMA, associated with delayed language development in children at 30 months. This critical mixture included a number of phthalates, bisphenol A, and perfluorinated chemicals.
  2. Experimental studies uncovered the molecular targets through which human-relevant levels of this mixture disrupted the regulation of endocrine circuits and of genes involved in autism and intellectual disability.
  3. The findings from the experimental studies were used to develop new principles for risk assessment of this mixture.

“It is striking that the findings in the experimental systems well reflected what we found in the epidemiological part, and that the effects could be demonstrated at normal exposure levels for humans,” said Joëlle Rüegg, professor of environmental toxicology at Uppsala University.

“Human brain organoids (advanced in vitro cultures that reproduce salient aspects of human brain development) afforded, for the first time, the opportunity to directly probe the molecular effects of this mixture on human brain tissue at stages matching those measured during pregnancy. Alongside other experimental systems and computational methods, we found that the mixture disrupts the regulation of genes linked to autism (one of whose hallmarks is language impairment), hinders the differentiation of neurons and alters thyroid hormone function in neural tissue,” said Giuseppe Testa, principal investigator of the EDC-MixRisk responsible for the human experimental modelling.

“One of the key hormonal pathways affected was thyroid hormone. Optimal levels of maternal thyroid hormone are needed in early pregnancy for brain growth and development, so it’s not surprising that there is an association with language delay as a function of prenatal exposure,” said Barbara Demeneix, professor of physiology and endocrinology at the Natural History Museum in Paris.

By combining these techniques, the researchers were able to show that 54% of children included in the SELMA study were at risk of delayed language development (at age 30 months) as they were prenatally exposed to a mixture of chemicals at levels that were above the levels predicted to impact neurodevelopment. Yet this risk fell below the exposure limits for individual chemicals.

Source: EURION Cluster

Categories : Ageing Diet and NutritionTags :

Soluble Fibre is Associated with Lower Dementia Risk

On By ModernMedia
Source: Pixabay

Drawing on a decades-long cohort study, researchers in Japan have found that higher levels of dietary fibre, particularly soluble fibre, are associated with a lower risk of dementia.

Fibre is known to have vital importance for a healthy digestive system and also has cardiovascular benefits like reduced cholesterol. In a new study published in Nutritional Neuroscience, researchers have shown that a high-fibre diet is also associated with a reduced risk of developing dementia, adding to evidence that fibre is also important for a healthy brain.

“Dementia is a devastating disease that usually requires long-term care,” says lead author of the study Professor Kazumasa Yamagishi. “We were interested in some recent research which suggested that dietary fibre may play a preventative role. We investigated this using data that were collected from thousands of adults in Japan for a large study that started in the 1980s.”

Between 1985 and 1999, 3739 participants who were generally healthy and aged between 40–64 completed dietary information surveys. They were then followed up from 1999 until 2020, and it was noted whether they developed dementia that required care.

Participants were assigned into four groups according to the amount of fibre in their diets. They found that the groups who ate higher levels of fibre had a lower risk of developing dementia.

The team also examined whether there were differences for the two main types of fibre: soluble and insoluble fibres. Soluble fibres, found in foods such as oats and legumes, are important for the beneficial bacteria that live in the gut as well as providing other health benefits. Insoluble fibres, found in whole grains, vegetables, and some other foods, are known to be important for bowel health. The researchers found that the link between fibre intake and dementia was more pronounced for soluble fibres.

The team has some ideas as to what might underlie the link between dietary fibre and the risk of dementia.

“The mechanisms are currently unknown but might involve the interactions that take place between the gut and the brain,” said Professor Yamagishi. “One possibility is that soluble fibre regulates the composition of gut bacteria. This composition may affect neuroinflammation, which plays a role in the onset of dementia. It’s also possible that dietary fibre may reduce other risk factors for dementia, such as body weight, blood pressure, lipids, and glucose levels. The work is still at an early stage, and it’s important to confirm the association in other populations.”

Source: University of Tsukuba

Categories : Cardiovascular DiseaseTags :

Cough Suppressant Could Lead to New Arrhythmia Treatment

On By ModernMedia
Photo by cottonbro from Pexels

An over-the-counter cough suppressant can knock some heart cells out of arrhythmia, a discovery that could lead to a new treatment for long QT syndrome. The finding, which was published in Nature Cardiovascular Research, was made using stem cells from patients with the disorder.

The QT interval on an electrocardiogram (ECG) represents the duration of the ventricular action potential, and this physiologically correlates with the duration of the ventricular depolarisation and repolarisation. Cardiac events and fatal arrhythmias may occur when the QT interval is prolonged either congenitally or through acquired causes. In people with long QT syndrome, cardiac cells are not always ready to produce the next beat, a situation that can knock the heart out of its normal rhythm, which may be life-threatening. For many people with long QT, no treatment can correct the heart cells or prevent arrhythmia.

Using mice to investigate how human heart arrhythmias can be stopped is difficult, so Masayuki Yazawa, PhD at the University of Columbia, turned to patient-derived reprogrammed stem cells, which can be made into heart cells in the lab.

The road to the discovery began several years ago when Dr Yazawa found that heart cells in the lab would resume a normal rhythm when a certain enzyme was inhibited. But the drugs used to inhibit the enzyme also had other unintended effects, such as liver toxicity, so alternatives were needed.

Looking through published research, the team learned that the enzyme could be inhibited through an intermediary molecule inside heart cells called SIGMAR1. Further reading suggested that SIGMAR1 could be targeted by a cough suppressant, dextromethorphan.

Dr Yazawa’s team found that the cough suppressant, when added to heart cells, successfully prepared the heart cells for the next beat and soothed the cells’ irregular rhythm.

The cough suppressant reset heart cells from people with Timothy syndrome, a genetic disorder that also causes other heart abnormalities, and from people with more common forms of long QT syndrome.

Dr Yazawa cautioned that it’s premature to use dextromethorphan to treat long QT patients; the drug has a short half-life and would have to be used long term, which might still have unknown adverse side effects.

“But our study shows that drugs targeting SIGMAR1 have potential to treat a wide array of patients with long QT syndrome,” said Dr Yazawa, “and we will continue to look for better options.”

Source: Columbia University

Categories : Substance UseTags :

LSD Microdosing Study Shows no Benefit

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Photo by Bruce Christianson on Unsplash

Published in Addiction Biology, a study into the effects of LSD “microdosing” found no evidence to back up proponents’ claims that it can improve mood and cognitive function. 

The study’s lead author, Chicago University Professor Harriet de Wit, noted that the study doesn’t disprove microdosing’s possible benefits, and that more investigation is needed. The study does show that taking small doses of LSD is safe. Prof De Wit said the findings demonstrate the important role clinicians can play when it comes to therapeutics claims about recreational drugs.

“These drugs are already being used out in the world, and it’s important for us to test them under controlled conditions, ensure their safety and see whether there’s some validity to the benefits people claim,” she said. “That’s something that has been missing from the conversation.”

The researchers studied the effects of four repeated low doses of LSD, administered under lab conditions every three to four days. One group of participants received 13 micrograms of the drug, a second group received 26 micrograms, and the third received a placebo. To put these low doses into context, the doses of LSD that are used to “trip” or to get high are typically 100–200 micrograms, she said.

LSD was chosen for the study because it’s the most commonly used psychedelic drug in microdosing.

Participants received the drugs during five-hour, supervised laboratory sessions. They also attended a drug-free follow-up session three to four days after the last dose. Participants were not told what kind of drug was being tested in the study – whether it was a stimulant, a tranquiliser or a hallucinogen – or that the study was about microdosing.

“We removed any expectations that this was a psychedelic drug,” Prof de Wit explained. “Because in the real world, people’s expectations can strongly influence their responses.”

To assess their mood and mental performance, the participants completed cognitive and emotional tasks both during the drug administration sessions and at the drug-free follow-up session. Some participants who received the higher dose reported feeling a modest “high” during the drug sessions, but the effects were mild.

The drug did not improve mood or affect participants’ performance on cognitive tests, either during the drug sessions or at the follow-up session.

Prof De Wit said the results came as a disappointing surprise. “Because so many people claim to have experienced benefits from microdosing, we expected to document some kind of beneficial effect under laboratory conditions,” she said.

Neurobiological reasons had also suggested that LSD might improve mood, because LSD acts through serotonin receptors, where traditional antidepressants are known to act.

“We can’t say necessarily that microdosing doesn’t work,” Prof de Wit said. “All we can say is that, under these controlled circumstances, with this kind of participant, these doses, and these intervals, we didn’t see a robust effect.”

People who microdose often have strong expectations of beneficial effects. “It is possible that these expectations contribute to the apparent benefits, or they may interact with the pharmacological effect of the drug,” she said.

LSD was confirmed to be safe, an unsurprising find which is in line with previous human and animal studies.

In fact, de Wit noted, participants appeared to build a tolerance to LSD over the course of the study, with the strongest “high” reported at the first session, and the perception of a drug effect diminishing at each subsequent session. That’s a good sign because it confirms the drug does not stay in the body or accumulate over time, she said.

Getting authorisation to use a controlled substance made the experiment challenging, as did the participants’ necessary time commitment. However, Prof de Wit emphasised the importance of such research, especially as practices like microdosing become commercialised.

“There are a lot of companies getting into the drug business, either with psychedelic drugs, or drugs like cannabidiol,” she noted. “And really there’s not very much empirical support to back up their claims. So, I think we have a responsibility to investigate and validate the claims.”

Source: University of Chicago

Categories : COVIDTags :

India’s True Pandemic Death Toll Likely Over Three Million

On By ModernMedia
FIG. 1. Percentages of adults reporting daily death in household, expected percentage in 2020, and daily confirmed COVID deaths in India, 1 June 2020 to 1 July 2021. COVID Tracker deaths (red line, left vertical scale) represent COVID deaths reported daily (smoothed for rolling 7-day averages) at age 35 or older, less a subtraction value of 0.59% to represent nonhousehold reporting. Expected all-cause deaths (grey dashed line, left vertical scale) per year of 3.4% (see text), with 7-day smoothed weekly adjustment from variation observed among 480,000 deaths in the Million Death Study from 2004 to 2014. Confirmed COVID deaths (blue bars, right vertical scale) are daily reports from Covid19india.org (2).
Credit: DOI: 10.1126/science.abm5154

An updated estimate for COVID mortalities in India puts the true number at over three million, which is so much higher than the official estimate of around a million that it would raise the World Health Organization’s official global death toll by 50%.

When the COVID Delta wave hit India over early to mid-2021, hospitals were filled beyond capacity, oxygen ran out, and community networks for tending to the dead were overwhelmed. At the time, government reporting put the death toll at under a million.

However, other sources estimated that the toll was far worse than this, likely in the millions. A more accurate measure of COVID mortality in India puts that number at 3.2 million people, according to a paper published in Science. 

“The analyses find that India’s cumulative COVID deaths by September 2021 were six to seven times higher than reported officially,” the international team of researchers wrote.

“You have to put that into context,” said Associate Professor of Economics Paul Novosad, co-author of the paper. “At the time that we were writing this, India was reporting about half a million official COVID deaths, the World Health Organization was reporting about 4 to 5 million COVID deaths globally, so just this adjustment – just correctly counting the deaths in India – is going to raise the global mortality count of COVID by almost 50%.”

The team looked at all-causes mortality from an independent survey of 140 000 adults, and from two government data sources including deaths reported in health facilities and registered deaths in 10 Indian states. Comparing these to previous years without COVID, they found that total deaths increased by 26% to 29% in the COVID period compared to total deaths in past years. This range was consistent across separate data sources, the researchers wrote.

“We’re triangulating on this number from a lot of different directions and have broad agreement regarding the range that we’re finding,” said Novosad.

Novosad’s work incorporates many novel types of data, including measures of well-being generated from satellite images, data collected by government programs, and archival administrative records not previously used for policy design. His research lab, which focuses on India, has created an open source data platform to support socioeconomic research in India and the developing world.

“A large part of my research agenda is based on finding new, 21st-century data sources and mobilising them for better research and policy,” he said.

Novosad believes this work can help answer many  critical questions about how governments and organisations can respond to the global pandemic.

“The decisions you make are better if they’re based on true facts about the world. If you don’t have data, then you just have to work on stories and impressions,” he said. “We need an empirical foundation for this kind of work.”

Source: Dartmouth College

Categories : Diseases, Syndromes and Conditions GeneticsTags :

A Life-changing Genetic Cure for Sickle Cell Patient

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Sickle cell disease occurs in people who inherit two copies of the sickle cell gene, one from each parent. This produces abnormal haemoglobin, called haemoglobin S. Credit: Darryl Leja, National Human Genome Research Institute, National Institutes of Health

Jimi Olaghere, who had suffered all his life from the chronic pain of sickle cell disease, recently received a genetic cure decades sooner than he would have believed possible.

Mr Olaghere is one of the first seven sickle cell patients who received a new gene-editing treatment going through its first clinic trials in the US. “It’s like being born again,” he said, adding that it has changed his life. “When I look back, it’s like, ‘Wow, I can’t believe I lived with that.'”

Mr Olaghere, 36 said: “You always have to be in a war mindset, knowing that your days are going to be filled with challenges.”

Sickle cell disease is caused by a mutated gene that results in abnormal haemoglobin, leading to blood cells becoming more rigid and taking on their characteristic sickle shape. These malformed cells often get stuck in blood vessels, giving rise to ischaemias and an increase in cardiovascular disease risk and organ damage. Mr Olaghere may need a hip replacement due to avascular necrosis.

The disease also causes chronic pain, which he likened to “shards of glass flowing through your veins or someone taking a hammer to your joints.”

Severe pain episodes known as crises are the hallmark of sickle cell disease. For years, Mr Olaghere was hospitalised on a monthly basis. Winters worsened the problem as the cold restricted surface blood vessels, increasing the risk of blockages. He moved to a warmer city, and became a tech entrepreneur as he didn’t think any employer would be sympathetic to going to the hospital so often.

His family urged him to participate in clinical trials or receive a bone marrow transplant. However, he thought it would take too much time and instead pinned his hopes on DNA editing “in the future, probably 20 to 50 years from now”.

But in 2019 he read about a new gene editing therapy and emailed the medical team right away. When he learned he was accepted, he said it was “the best Christmas present ever”. As the pandemic hit and flights were cancelled, he was still able to make the four-hour drive for treatment appointments.
In order to genetically edit his stem cells the stem cells were flushed out of his bone marrow and into the bloodstream for collection.

“You sit there for eight hours and this machine is literally just sucking all the blood out of you,” he said.

The process left him physically and mentally drained, and still needed  blood transfusions. Mr Olaghere had to go through this process, the most difficult of all for him, four times. 

The key to the treatment lies not in correcting the genetic defect that produces the cell but rather sidestepping it by getting the body to use an alternative: foetal haemoglobin 

Ordinarily, at around 40 weeks of pregnancy, a genetic switch called BCL11A is flipped and the body starts producing adult haemoglobin – which is the only form affected by sickle cell disease. 

“Our approach is to turn that switch off and increase the production of foetal haemoglobin again, basically turning the clock back,” explained Dr Haydar Frangoul, who treated Mr at the Sarah Cannon Research Institute.

Mr Olaghere’s stem cells were sent to Vertex Pharmaceuticals’ laboratories for genetic editing. By September 2020, the engineered cells were ready to be infused into his body. “It was the week of my birthday, actually. So it was almost like getting a new life,” he recalled.

The original faulty stem cells that remained in his body were killed off with chemotherapy, and then genetically engineered replacements were infused into his body to produce sickle-free blood.

“I remember waking up without any pain and feeling lost,” he said. “Because my life is so associated with pain, it’s just a part of who I am. It’s weird now that I don’t experience it any more.'”

Dr Frangoul said that the first seven patients’ results have been “nothing short of amazing” and represented a “functional cure” for their disease.
“What we are seeing is patients are going back to their normal life, none have required admission to hospital or doctor visits because of sickle cell related complications,” Dr Frangoul said.

So far, the genetic technique has been conducted on 45 patients with either sickle cell disease or beta thalassaemia. However, the data are still being gathered.

Source: BBC News