Day: August 5, 2022

Categories : UncategorizedTags :

Hyaluronic Acid Wakes up Stem Cells to Repair Muscles

On By ModernMedia
Credit: Dr Kiran Nakka

A new study published in the journal Science reveals a unique form of cell communication that controls muscle repair, coordinated by hyaluronic acid. In damaged muscle, stem cells must work together with immune cells to complete the repair process, yet how these cells coordinate to ensure the efficient removal of dead tissue before making new muscle fibres has remained unknown.

“When muscles get damaged, it is important for immune cells to quickly enter the tissue and remove the damage before stem cells begin repair,” said Dr Jeffrey Dilworth, senior author on the study. “Our study shows that muscle stem cells are primed to start repair right away, but the immune cells maintain the stem cells in a resting state while they finish the cleanup job. After about 40 hours, once the cleanup job is finished, an internal alarm goes off in the muscle stem cells that allows them to wake up and start repair.”

Dr Dilworth and his team identified hyaluronic acid as the key ingredient in this internal alarm clock that rouses muscle stem cells from their slumber. When muscle damage occurs, stem cells start producing and coating themselves with hyaluronic acid, which, when thick enough, blocks the sleep signal from the immune cells, thereby causing the muscle stem cells to wake up.

Using mouse and human tissues, the researchers also discovered how muscle stem cells control the production of hyaluronic acid using epigenetic marks on the Has2 gene.

“Interestingly, ageing is associated with chronic inflammation, muscle weakness and a reduced ability of muscle stem cells to wake up and repair damage,” said lead author Dr Kiran Nakka. “If we could find a way to enhance hyaluronic acid production in the muscle stem cells of older people it might help with muscle repair.”

The regenerative effect of hyaluronic acid seems to depend on it being produced by the muscle stem cells, the authors noted. They are currently investigating if drugs could epigenetically stimulate muscle stem cells to increase their production of hyaluronic acid.

Categories : NeurologyTags :

Why do We Struggle to Recognise the Faces of People of Other Races?

On By ModernMedia
An Asian man and two white men enjoying St. Patrick’s Day Photo by Pressmaster on Pexels

In a study published in Scientific Reports, cognitive psychologists at the believe they have discovered the answer to a 60-year-old question as to why people find it more difficult to recognise faces from visually distinct racial backgrounds than they do their own.

This phenomenon named the Other-Race Effect (ORE) was first discovered in the 1960s. Humans seem to use a variety of markers to recognise people, instead of photographically memorising their faces, which may be based on what they observe in others around them. Hair and eye colour may be used by white people to tell apart other white people since those features vary considerably in that racial group. Setting may also be important: some people might not notice that the centre man in the picture above is Asian while his friends on either side are white.

The ORE has consistently been demonstrated through the Face Inversion Effect (FIE) paradigm, where people are tested with pictures of faces presented in their usual upright orientation and inverted upside down. Such experiments have consistently shown that the FIE is larger when individuals are presented with faces from their own race as opposed to faces from other races.

The findings spurred decades of debate, and social scientists took the view that indicates less motivation for people to engage with people of other races, making a weaker memory for them. Cognitive scientists posited it is down to a lack of visual experience of other-race individuals, resulting in less perceptual expertise with other-race faces.

Now, a team in the Department of Psychology at Exeter, using direct electrical current brain stimulation, has found that the ORE would appear to be caused by a lack of cognitive visual expertise and not by social bias.

“For many years, we have debated the underpinning causes of ORE,” said Dr Ciro Civile, the projects lead researcher.

“One of the prevailing views is that it is predicated upon social motivational factors, particularly for those observers with more prejudiced racial attitudes. This report, a culmination of six years of funded research by the European Union and UK Research and Innovation, shows that when you systematically impair a person’s perceptual expertise through the application of brain stimulation, their ability to recognise faces is broadly consistent regardless of the ethnicity of that face.”

The research was conducted at the University of Exeter’s Washington Singer Laboratories, using non-invasive transcranial Direct Current Stimulation (tDCS) specifically designed to interfere with the ability to recognise upright faces. This was applied to the participants’ dorsolateral prefrontal cortex, via a pair of sponges attached to their scalp.

The team studied the responses of nearly 100 White European students to FIE tests, splitting them equally into active stimulation and sham/control groups. The first cohort received 10 minutes of tDCS while performing the face recognition task involving upright and inverted Western Caucasian and East Asian (Chinese, Japanese, Korean) faces. The second group, meanwhile, performed the same task while experiencing 30 seconds of stimulation, randomly administered throughout the 10 minutes – a level insufficient to induce any performance change.

In the control group, the size of the FIE for own-race faces was found to be almost three times larger than the one found for other-race faces confirming the robust ORE. This was mainly driven by participants showing a much better performance at recognising own-race faces in the upright orientation, compared to other-race faces – almost twice as likely to correctly identify that they had seen the face before.

In the active tDCS group, the stimulation successfully removed the perceptual expertise component for upright own-race faces and resulted in no difference being found between the size of the FIE for own versus other-race faces. And when it came to recognising faces that had been inverted, the results were roughly equal for both groups for both races, supporting the fact that people have no expertise whatsoever at seeing faces presented upside down.

“Establishing that the Other-Race Effect, as indexed by the Face Inversion Effect, is due to expertise rather than racial prejudice will help future researchers to refine what cognitive measures should and should not be used to investigate important social issues,” said Ian McLaren, Professor of Cognitive Psychology. “Our tDCS procedure developed here at Exeter can now be used to test all those situations where the debate regarding a specific phenomenon involves perceptual expertise.”

Source: University of Exeter

Categories : Diseases, Syndromes and ConditionsTags :

HSV-1 Driven by Ancient Migrations – and Introduction of Kissing

On By ModernMedia
Photo by Cottonbro on Pexels

The HSV-1 virus strain behind facial herpes, commonly known as cold sores, emerged approximately 5000 years ago, according to University of Cambridge-led research published in Science Advances. The virus arose in the wake of vast Bronze Age migrations into Europe from the Steppe grasslands of Eurasia, and associated population booms that boosted transmission.

Two-thirds of the world’s population below the age of 50 now carry HSV-1, manifesting as occasional lip sores. In combination with other ailments – sepsis or even COVID, for example – the virus can be fatal. In 2018, two women died of HSV-1 infection in the UK following Caesarean births.

Herpes has an ancestry dating back millions of years, infecting species from bats to coral. Despite being prevalent among humans today, however, scientists say that ancient examples of HSV-1 were surprisingly hard to find.

According to the study authors of the study, , the Neolithic flourishing of facial herpes detected in the ancient DNA may have coincided with the advent of a new cultural practice imported from the east: romantic and sexual kissing.    

“Facial herpes hides in its host for life and only transmits through oral contact, so mutations occur slowly over centuries and millennia,” said Dr Charlotte Houldcroft, co-senior author.

“We need to do deep time investigations to understand how DNA viruses like this evolve. Previously, genetic data for herpes only went back to 1925.”

The team managed to hunt down herpes in the remains of four individuals stretching over a thousand-year period, and extract viral DNA from the roots of teeth. Herpes often flares up with mouth infections: at least two of the ancient cadavers had gum disease and a third smoked tobacco.

The oldest sample came from an adult male excavated in Russia’s Ural Mountain region, dating from the late Iron Age around 1500 years ago.

Two further samples were local to Cambridge, UK. One a female from an early Anglo-Saxon cemetery a few miles south of the city, dating from 6-7th centuries CE. The other was a young adult male from the late 14th century who had suffered appalling dental abscesses. 

The final sample came from a young adult male excavated in Holland: a fervent clay pipe smoker, most likely massacred by a French attack on his village by the banks of the Rhine in 1672. 

“We screened ancient DNA samples from around 3000 archaeological finds and got just four herpes hits,” said co-lead author Dr Meriam Guellil, from Tartu University’s Institute of Genomics.

“By comparing ancient DNA with herpes samples from the 20th century, we were able to analyse the differences and estimate a mutation rate, and consequently a timeline for virus evolution,” said co-lead author Dr Lucy van Dorp, from the UCL Genetics Institute.     

Co-senior author Dr Christiana Scheib said: “Every primate species has a form of herpes, so we assume it has been with us since our own species left Africa.”

“However, something happened around five thousand years ago that allowed one strain of herpes to overtake all others, possibly an increase in transmissions, which could have been linked to kissing.”

The first known report of kissing is a Bronze Age manuscript from South Asia, and suggest the custom, not found in most human cultures, may have travelled westward with migrations into Europe from Eurasia.   

In fact, centuries later, the Roman Emperor Tiberius tried to ban kissing at official functions to prevent disease spread, a decree that may have been herpes-related.

However, for most of human prehistory, HSV-1 transmission would have been ‘vertical’: passing from infected mother to newborn child.

Source: University of Cambridge

Categories : GastrointestinalTags :

Gold Nanoparticles Ease IBD Inflammatory Symptoms

On By ModernMedia
Gold bars
Photo by Jingming Pan on Unsplash

In a Chinese study published in Fundamental Research, researchers explored a treatment for inflammatory bowel disease (IBD) using ultrasmall gold nanoparticles. Previous studies showed that these nanoclusters effectively eliminate a variety of reactive oxygen species (ROS), elevated levels of which are commonly found in the gastrointestinal tract of IBD patients.

IBD includes ulcerative colitis and Crohn’s disease, both of which tend to be debilitating, lifelong conditions that can prove fatal in severe cases. Currently, there is no cure for IBD. The main clinical treatments are drugs such as aminosalicylic acid preparations and corticosteroids, but they are often accompanied by gastrointestinal problems, anaemia, and various intestinal complications. Finding alternative, more effective options is a priority for researchers.

The team found that administering gold (Au25) nanoclusters orally to mice suffering from colitis eliminated ROS, increased antioxidant enzymes, and inhibited pro-inflammatory cytokines, without any obvious side effects. According to paper author Fei Wang of China’s The Seventh Affiliated Hospital of Sun Yat-Sen University, a reduction in the inflammation in the gastrointestinal tracts of the mice was observed within 24 hours. She added: “And the fact that these nanoclusters can be administered orally, means there is no need for invasive procedures.”

Additionally, the team found that the nanoclusters have a number of benefits when compared with natural enzymes used in traditional IBD treatments, including lower cost, better stability, mass synthesis and easier storage. Wang explained: “The storage of Au25 nanoclusters was not affected by pH, temperature or solution medium, and their good physiological stability and acid resistance meant they were easily able to access the inflamed colon. They also have good biocompatibility and chemical stability and can remove a variety of ROS.”

Wang concluded: “Au25 nanoclusters offer a promising strategy in the research field of nanomedicine therapy for IBD. We believe this study demonstrates their value as a scientific basis and experimental basis for the clinical treatment of IBD.”

Source: EurekAlert!

Categories : Hospitals Medical IndustryTags :

Mediclinic Agrees to £3.7bn Buyout by Remgro Consortium

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After turning down a previous bid, Mediclinic has agreed to a £3.7 billion buyout by a consortium consisting of investment group Remgro Limited and Mediterranean Shipping Company (MSC).

The buyout will give Remgro and MSC, through a jointly owned subsidiary, a 50/50 stake in the healthcare company.

The offer still has to be cleared by 75% of Mediclinic’s shareholders (Remgro is already a shareholder), but according to the The Daily Maverick, Mediclinic’s CFO, Gert Hattingh, the company’s directors consider the terms of the sale to be fair and reasonable. In addition, regulatory approval must be granted in South Africa, Namibia, Switzerland and Cyprus for the acquisition to proceed.

The current bid is offering 504 pence per share, a 35% increase on the first rejected offer, according to MoneyWeb. With the £3.7 billion buyout, Mediclinic has an implied enterprise value of roughly £6.1 billion.

Mediclinic operates 74 hospitals as of March this year, with 50 hospitals in Southern Africa (three of which are in Namibia), 17 hospitals in Switzerland, seven in the UAE and a 200-bed hospital due to open in Saudi Arabia.

The 72-year-old Johann Rupert who leads Remgro and has a 7% ownership, is South Africa’s richest person, with a personal fortune of $8.8bn, according to the most recent estimate by Forbes.

Commenting on the acquisition, Dame Inga Beale, Chair of Mediclinic, said: “The recommended offer represents a near-term value realisation for Mediclinic shareholders at an attractive premium.

“Over 39 years, Mediclinic has developed into the leading international healthcare services group it is today. During this time, Remgro has remained a supportive long-term shareholder. Together with SAS, the Consortium’s resources will put Mediclinic in a strong position to continue to serve patients through our broad range of high-quality healthcare services.”