Tag: 25/1/22

Categories : AgeingTags : Leave a comment

Muscles may Stay Younger at an Epigenetic Level through Exercise

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Photo by Kanasi on Unsplash

While the benefits of exercise in ageing have been well established, such as lowering risk of cardiovascular disease, a new study that used mice demonstrated that exercise in aged individuals could help muscles stay younger at an epigenetic level.

Despite generating a wealth of data, the study, which was published in Aging Cell, made use of a relatively straightforward experiment. Lab mice nearing the end of their natural lifespan, at 22 months, were allowed access to a weighted exercise wheel. Mice generally run voluntarily, without any coercion. Older mice will run anywhere from six to eight kilometres a day, mostly in spurts, while younger mice may run up to 10 to 12 kilometres. The weighted wheel ensured they built muscle. While there isn’t a direct analogue to most human exercise routines, first author Kevin Murach, assistant professor at the University of Arkansas, likened it to “a soldier carrying a heavy backpack many miles.”

When the mice were examined after two months of progressive weighted wheel running, it was determined that they were the epigenetic age of mice eight weeks younger than sedentary mice of the same age – 24 months. Murach noted that while the specific strain of mice and their housing conditions can impact lifespans, “historically, they start dropping off after 24 months at a significant rate.” Needless to say, when your lifespan is measured in months, an extra eight weeks – roughly 10 percent of that lifespan – is a noteworthy gain.

The science behind this hinges largely on DNA methylation, where methyl groups attach to DNA, altering their function. As the body ages, there tends to be increased DNA methylation, or even hypermethylation, at promoter sites on genes in muscle. “DNA methylation changes in a lifespan tend to happen in a somewhat systematic fashion,” Murach explained, “to the point you can look at someone’s DNA from a given tissue sample and with a fair degree of accuracy predict their chronological age.” Due to this, researchers can use one of a number of “methylation clocks” to determine the age of a DNA sample.

While the paper strengthens the case for exercise, much work remains to be done. Though there is a clear connection between methylation and ageing, the relationship between methylation and muscle function is less clear. Murach is not yet prepared to say that the reversal of methylation with exercise causes improved muscle health. “That’s not what the study was set up to do,” he explained. However, he intends to pursue future studies to determine if “changes in methylation result in altered muscle function.”

Source: University of Arkansas

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A New Method to Block Listeria Infections

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Photo by Drew Hays on Unsplash

University of Queensland researchers have unlocked a way of fighting Listeria infections, which can cause severe and potentially illness in pregnant women and immunocompromised individuals.

Listeria infection does not cause disease in most people, but can be deadly for the immunocompromised and is also a major health concern during pregnancy and can lead to miscarriage, stillbirth and premature birth.

From 2017 to 2018, South Africa suffered the world’s largest listeriosis outbreak, in which there were 216 deaths out of 1060 recorded cases.

During the study, published in the journal PLOS Pathogens, researchers discovered a way to block Listeria from making the proteins that allow bacteria to survive and multiply in immune cells. University of Queensland’s Professor Antje Blumenthal said using a small, drug-like inhibitor has improved their understanding of Listeria’s weak spot.

“Listeria is found in the soil and sometimes in raw foods. Once ingested it can hide from the immune system and multiply inside immune cells,” Prof Blumenthal said.

“Instead of killing the bacteria, the immune cells are used by the bacteria to multiply and are often killed by Listeria growing inside them.

“Our study showed the bacteria could be cleared with a small drug-like inhibitor that targets the ‘master regulator’ of the proteins that help Listeria grow in immune cells. The inhibitor helped the immune cells survive infection and kill the bacteria.”

Previously, studies into Listeria’s ‘master regulator’, which controls critical proteins that make the bacteria virulent, have mostly been based on engineered bacteria, or mutated versions of these proteins.

“By using a drug-like inhibitor, we were able to use molecular imaging and infections studies to better understand what happens to Listeria when the bacteria cannot effectively grow inside immune cells and hide from immune defence mechanisms,” Prof Blumenthal said.

“We hope that our discovery, together with recent research into the master proteins’ molecular structure and functions, could guide the development of inhibitors and new drugs to treat Listeria infection.”

“Our findings could also inform design of inhibitors against related proteins that are found in different bacteria,” Prof Blumenthal said.

Source: University of Queensland

Categories : Metabolic DisordersTags : Leave a comment

Simple Dietary Supplement in Type 1 Diabetes Calms Immune System

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Gut microbiome. Credit: Darryl Leja, NIH

A clinical trial performed by Australian scientists showed that a simple dietary supplement that targeted gut microbiota could improve gut health and strengthen the immune system in individuals with type 1 diabetes.

The supplement is a type 2–resistant starch consisting of a high-amylose (70%) maize starch that has been modified by bonding the acetate and butyrate. The supplement is resistant to digestion in the upper gastrointestinal tract and delivers a very high yield of short-chain fatty acids (SCFAs) in the colon. This makes it a useful tool to measure the effect of SCFAs on intestinal biology.

According to senior author and lead investigator Dr Eliana Marino, the study tested 21 adults with type 1 diabetes who incorporated the supplement into their daily diet for six weeks. Increased production of metabolites by the gut microbiota was observed, specifically SCFAs. This has an important role in preventing type 1 diabetes.

“People with 1 diabetes have shown altered gut microbiota and reduced production of short-chain fatty acids in stools and blood. We previously have demonstrated that the supplement used in this human study protected mice from diabetes,” said Dr Marino.

Published in Microbiome, the clinical trial showed that participants’ blood immune cells developed a more regulatory phenotype post-intervention.

“We were very excited to find that blood immune cells had become more regulated. Because type 1 diabetes is caused when the immune system becomes too activated and attacks the insulin-producing cells in the pancreas,” said co-lead researcher Associate Professor Hamilton-Williams.

“Type 1 diabetes is a lifelong autoimmune disease that is on the rise with no cure. Individuals living with type 1 diabetes depend on insulin treatment. As a consequence, they can develop late life-threatening inflammatory complications, such as kidney failure, neurological and cardiovascular diseases,” said co-lead researcher Associate Professor Sonia Saad

“While glucose control and insulin requirements didn’t change overall, the participants with the highest short-chain fatty acid concentrations showed the best glucose control after the supplementation,” said co-lead researcher Dr Kirstine Bell.

“Using this supplement for longer and starting it earlier in the disease could potentially stop the immune attack, preserving insulin-producing cells and improving glucose regulation,” said Dr Marino.

“This dietary supplementation represents a safe and accessible alternative therapy for many children with type 1 diabetes or other autoimmune diseases. Also, it could decrease the risk of subsequent inflammatory complications such as cardiovascular disease as clinical trials are underway,” said Dr Marino.

Source: Monash University

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A New Test to Diagnose Dizziness without Deafening

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Source: Miika Luotio on Unsplash

Swedish researchers have developed a new way to diagnose dizziness problems in a simpler and less painful way than the old method. A bone conduction speaker, easily attached behind the ear, can make the diagnosis more efficient and safer – especially for patients with pre-existing hearing problems.

For patients with dizziness, the relationship of dizziness and hearing is used for diagnosis. Typically, a ‘VEMP’ test (Vestibular Evoked Myogenic Potentials) is performed. With loud sounds, the test evokes a muscle reflex contraction in the neck and eye muscles, triggered by the vestibular system. In their new approach, reported in Communications Medicine, researchers at Chalmers University instead made use of bone-conducted sounds to achieve better results.

“We have developed a new type of vibrating device called B250 that is placed behind the ear of the patient during the test,” said Bo Håkansson, a professor at Chalmers University. “The vibrating device is small and compact in size and optimised to provide an adequate sound level for triggering the reflex at frequencies as low as 250 Hz, which we have found to be optimal for VEMP stimulation. Previously, no vibrating device has been available that was directly adapted for this type of test of the balance system.”

In bone conduction transmission, sound waves are transformed into vibrations through the skull, stimulating the cochlea within the ear, in the same way as when sound waves normally go through the ear canal, the eardrum and the middle ear. This can be used in various technologies such as in hearing aids.

Half of over-65s suffer from dizziness, but the causes can be difficult to diagnose for several reasons. Dizziness in 50% of those cases results from vestibular system problems. But current VEMP methods have major shortcomings and can cause hearing loss and discomfort for patients. The VEMP test uses very high sound levels which can cause permanent hearing damage. Additionally, if certain types of hearing loss are already present, the test can be inconclusive.

“The previous test was like a machine gun going off next to the ear – with this bone-conduction method it will be much more comfortable. The sound levels to which patients are exposed can be minimised. The test can be performed at 40 decibels lower than today’s method, which uses air-conducted sounds through headphones. This eliminates the risk that the test itself could cause hearing damage,” said researcher Karl-Johan Fredén Jansson, who made all the measurements in the project.

“The benefits also include safer testing for children, and that patients with impaired hearing function due to chronic ear infections or congenital malformations in the ear canal and middle ear can still be diagnosed for the origin of their dizziness,” said Prof Håkansson.

The device has now been tested and developed in several patient studies that have been published internationally, both with healthy individuals to obtain normal data, and in patients suffering from various types of dizziness. The device is compatible with standardised equipment for balance diagnostics in healthcare, which makes it easy to use. In addition to the benefits for patients, the cost of the new technology is also judged to be lower than the corresponding equipment used today.

Source: News-Medical.Net

Categories : Ethics and LawTags : Leave a comment

Medical Bodies Push Back against Commission for Gender Equality’s Statement

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Image source: NCI on Unsplash

The South African Medical Research Council (SAMRC), along with other professional medical and scientific institutions released a statement  distancing themselves from the Commission for Gender Equality’s (CGE) press release of 16 January, 2022, titled “Warning Against Imposing Mandatory Covid-19 Vaccination on Employees and Students”. [PDF]

The CGE cited an article published in Obstetrics and Gynaecology which found that women receiving Pfizer-BioNTech, Moderna or J&J COVID vaccines, vaccine administration was associated with less than a one-day change in cycle length for both vaccine-dose cycles compared with pre-vaccine cycles. The article concluded that clinically meaningful change in menstrual cycle duration associated with COVID vaccination was found. 

The CGE used this study as justification, cautioning businesses and institutions against mandatory vaccination and recommended against sanctions for employees who chose to remain vaccinated.

The signatories expressed their concern at the contents of the statement which is at odds with the scientific understanding of COVID vaccinations, a concern which is compounded by the “enormous influence” of the GCE.

They accept that the vaccine mandates are subject to legal scrutiny, but take issue with the commission “trying to bolster its argument by wrongly insinuating that COVID vaccination has the potential to harm women’s health.”

They also point out that the commission seems to disregard the much greater risks to women and their unborn babies of COVID infection, while misinterpreting evidence on minor menstrual cycle lengthening. This creates fear and confusion in vaccinated women, and may increase vaccine hesitancy.

“It fails to appreciate that one in six unvaccinated pregnant women admitted to hospital in South Africa with COVID infection requires mechanical ventilation, and one in 16 has a fatal outcome,” the signatories stated.

They noted that COVID vaccination provides upwards of 80% protection against severe disease, hospitalisation and death.

They endorse the view of the College of Obstetricians and Gynaecologists of South Africa, which draws on research of the highest quality, that the menstrual effects are minor.

The evidence is “indisputable” that COVID vaccination is safe, does not negatively affect women’s bodies and saves the lives of women, they stress. Statements to the contrary are strongly repudiated.

“We are of the view that the CGE, like all state institutions, medical and scientific bodies, social partners and civil society formations working in the fields of women’s rights, empowerment and equality, should urge women to get vaccinated and advance and defend their rights to all relevant information about and access to vaccination.”

The signatories call on the CGE to withdraw its 16 January statement and to share with it scientific facts on COVID vaccination and women’s health.

Source: South African Medical Research Council