Tag: 28/8/23

Categories : Metabolic DisordersTags : Leave a comment

Don’t Overlook Latent Autoimmune Diabetes in Adults, Researchers Caution

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Photo by Photomix Company on Pexels

To reduce the risk of complications, it is important to measure antibodies those with adult onset diabetes, while also considering the levels of these antibodies.

In a study published in the journal Diabetes Care, researchers demonstrate that individuals with Latent Autoimmune Diabetes in Adults (LADA) have an equally high risk of developing cardiovascular disease as people with type 2 diabetes, but a higher risk of developing retinopathy and poorer glucose control. Many also lack adequate treatment.

LADA is a common but relatively unknown form of diabetes. Similar to type 1 diabetes, it is an autoimmune disease characterised by antibodies against insulin-producing cells. It develops in adulthood, and the autoimmune process progresses more slowly than in type 1 diabetes. LADA also shares features with type 2 diabetes, which means those affected risk getting the wrong diagnosis if antibodies are not measured. Incorrect diagnosis can result in inadequate treatment. Previous studies suggest that between five and ten percent of all individuals initially diagnosed with type 2 diabetes actually have LADA. Researchers at Karolinska Institutet, and the Universities of Lund and Helsinki set out to examine the risk of complications in LADA.

Our results emphasise the importance of diagnosing LADA correctly and careful monitoring of glucose control in these individuals, so that treatment can be intensified if needed, thereby reducing the risk of complications.

Yuxia Wei, PhD-student and Sofia Carlsson, senior lecturer, Institute of Environmental Medicine, Karolinska Institutet

According to the study LADA was characterised by fewer metabolic risk factors than type 2 diabetes, such as high blood pressure and high blood lipids. However, a lower proportion of individuals with LADA achieved good glucose control. The lack of glucose control was most evident in LADA patients with high levels of the antibody GADA (glutamic acid decarboxylase antibody). A significant portion of individuals with LADA lacked any glucose-lowering treatment.

The results of the new study are based on the ESTRID study, where researchers followed over 4000 individuals with diabetes, of whom 550 had LADA, for up to 12 years after diagnosis. According to the researchers, it is the most comprehensive study to date regarding the risk of complications in LADA.

Source: Karolinska Institutet

Categories : Cardiovascular Disease GenderTags : Leave a comment

In Half of Sudden Cardiac Arrests, Symptoms Appear 24 Hours Earlier

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Photo by Camilo Jimenez on Unsplash

Thanks to a study recently published in The Lancet Digital Health, clinicians are one step closer to helping people catch a sudden cardiac arrest before it happens. The study, found that 50% of individuals who experienced a sudden cardiac arrest also experienced a telling symptom 24 hours before their loss of heart function.

The investigators from the Smidt Heart Institute at Mount Sinai also learned that this warning symptom was different for women than it was for men. For women, the most prominent symptom of an impending sudden cardiac arrest was shortness of breath, whereas men experienced chest pain. Smaller subgroups of both genders experienced abnormal sweating and seizure-like activity.

Out-of-hospital sudden cardiac arrest is fatal 90% of the time, so there is an urgent need to better predict and prevent the condition.

“Harnessing warning symptoms to perform effective triage for those who need to make a 911 call could lead to early intervention and prevention of imminent death,” said sudden cardiac arrest expert Sumeet Chugh, MD, senior author of the study. “Our findings could lead to a new paradigm for prevention of sudden cardiac death.”

For this study, investigators used two established and ongoing community-based studies, each developed by Chugh: the ongoing Prediction of Sudden Death in Multi-Ethnic Communities (PRESTO) Study in Ventura County, California, and the Oregon Sudden Unexpected Death Study (SUDS), based in Portland, Oregon.

Both studies provide Cedars-Sinai investigators with unique, community-based data to establish how to best predict sudden cardiac arrest.

“It takes a village to do this work,” said Chugh. “We initiated the SUDS study 22 years ago and the PRESTO study eight years ago. These cohorts have provided invaluable lessons along the way. Importantly, none of this work would have been possible without the partnership and support of first responders, medical examiners and the hospital systems that deliver care within these communities.”  

In both the Ventura and Oregon studies, Smidt Heart Institute investigators evaluated the prevalence of individual symptoms and sets of symptoms prior to sudden cardiac arrest, then compared these findings to control groups that also sought emergency medical care.

The Ventura-based study showed that 50% of the 823 people who had a sudden cardiac arrest witnessed by a bystander or emergency medicine professional, such as an emergency medicine service (EMS) responder, experienced at least one telltale symptom before their deadly event. The Oregon-based study showed similar results.

“This is the first community-based study to evaluate the association of warning symptoms – or sets of symptoms – with imminent sudden cardiac arrest using a comparison group with EMS-documented symptoms recorded as part of routine emergency care,” said Eduardo Marbán, MD, PhD, executive director of the Smidt Heart Institute.

Such a study, Marbán says, paves the way for additional prospective studies that will combine all symptoms with other features to enhance prediction of imminent sudden cardiac arrest.

“Next we will supplement these key sex-specific warning symptoms with additional features – such as clinical profiles and biometric measures– for improved prediction of sudden cardiac arrest,” said Chugh.

Source: Cedars-Sinai

Categories : Ageing GeneticsTags : Leave a comment

Mice Live Longer when Given a Longevity Gene from Naked Mole Rats

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CRISPR-Cas9 is a customisable tool that lets scientists cut and insert small pieces of DNA at precise areas along a DNA strand. This lets scientists study our genes in a specific, targeted way. Credit: Ernesto del Aguila III, National Human Genome Research Institute, NIH

In a ground-breaking advance in aging research, scientists have successfully transferred a longevity gene from naked mole rats to mice, resulting in improved health and an extension of the mouse’s lifespan.

Naked mole rats are known for their long lifespans and exceptional resistance to age-related diseases. By introducing a specific gene responsible for enhanced cellular repair and protection into mice, the researchers have opened exciting possibilities for unlocking the secrets of aging and extending human lifespan.

“Our study provides a proof of principle that unique longevity mechanisms that evolved in long-lived mammalian species can be exported to improve the lifespans of other mammals,” says Vera Gorbunova, professor at Rochester University. Gorbunova, along with Andrei Seluanov, a professor of biology, and their colleagues, report in a study published in Nature that they successfully transferred a gene responsible for making high molecular weight hyaluronic acid (HMW-HA) from a naked mole rat to mice. This led to improved health and an approximate 4.4 percent increase in median lifespan for the mice.

A unique mechanism for cancer resistance

Naked mole rats are mouse-sized rodents that have exceptional longevity for rodents of their size; they can live up to 41 years, nearly ten times as long as similar-size rodents. Unlike many other species, naked mole rats do not often contract age-related diseases such neurodegeneration, cardiovascular disease, arthritis, and cancer. Gorbunova and Seluanov have devoted decades of research to understanding the unique mechanisms that naked mole rats use to protect themselves against aging and diseases.

The researchers previously discovered that HMW-HA is one mechanism responsible for naked mole rats’ unusual resistance to cancer. Compared to mice and humans, naked mole rats have about ten times more HMW-HA in their bodies. When the researchers removed HMW-HA from naked mole rat cells, the cells were more likely to form tumours.

Gorbunova, Seluanov, and their colleagues wanted to see if the positive effects of HMW-HA could also be reproduced in other animals.

Transferring an HMW-HA-producing gene

The team genetically modified a mouse model to produce the naked mole rat version of the hyaluronan synthase 2 gene, which is the gene responsible for making a protein that produces HMW-HA. While all mammals have the hyaluronan synthase 2 gene, the naked mole rat version seems to be enhanced to drive stronger gene expression.

The researchers found that the mice that had the naked mole rat version of the gene had better protection against both spontaneous tumors and chemically induced skin cancer. The mice also had improved overall health and lived longer compared to regular mice. As the mice with the naked mole rat version of the gene aged, they had less inflammation in different parts of their bodies — inflammation being a hallmark of aging — and maintained a healthier gut.

While more research is needed on exactly why HMW-HA has such beneficial effects, the researchers believe it is due to HMW-HA’s ability to directly regulate the immune system.

A fountain of youth for humans?

“It took us 10 years from the discovery of HMW-HA in the naked mole rat to showing that HMW-HA improves health in mice,” Gorbunova says. “Our next goal is to transfer this benefit to humans.”

They believe they can accomplish this through two routes: either by slowing down degradation of HMW-HA or by enhancing HMW-HA synthesis.

“We already have identified molecules that slow down hyaluronan degradation and are testing them in pre-clinical trials,” Seluanov says. “We hope that our findings will provide the first, but not the last, example of how longevity adaptations from a long-lived species can be adapted to benefit human longevity and health.”

Source: University of Rochester

Categories : Medical Research & Technology OphthalmologyTags : Leave a comment

A Smart Contact Lens Battery Powered by Tears

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Photo by Arteum.ro on Unsplash

Singapore scientists have developed a flexible battery as thin as a human cornea, which can store electricity when immersed in a saline solution such as tears. The scientists described their research in Nano Energy, and believe that this technology could one day power smart contact lenses.

Smart contact lenses are high-tech contact lenses capable of displaying visible information on the cornea and can be used to access augmented reality as well as monitoring health and their normal function of correcting vision. But they need power, and existing rechargeable batteries rely on wires or induction coils that contain metal and are unsuitable for use in the human eye, as they are uncomfortable and present risks to the user.

The battery, developed by Nanyang Technological University, is made of biocompatible materials and does not contain wires or toxic heavy metals, such as those in lithium-ion batteries or wireless charging systems. It has a glucose-based coating that reacts with the sodium and chloride ions in the saline solution surrounding it, while the water the battery contains serves as the ‘wire’ or ‘circuitry’ for electricity to be generated.

The battery could also be powered by human tears as they contain sodium and potassium ions, at a lower concentration. Testing the current battery with a simulated tear solution, the researchers showed that the battery’s life would be extended an additional hour for every twelve-hour wearing cycle it is used. The battery can also be charged conventionally by an external power supply.

Associate Professor Lee Seok Woo, from NTU’s School of Electrical and Electronic Engineering (EEE), who led the study, said: “This research began with a simple question: could contact lens batteries be recharged with our tears? There were similar examples for self-charging batteries, such as those for wearable technology that are powered by human perspiration.

“However, previous techniques for lens batteries were not perfect as one side of the battery electrode was charged and the other was not. Our approach can charge both electrodes of a battery through a unique combination of enzymatic reaction and self-reduction reaction. Besides the charging mechanism, it relies on just glucose and water to generate electricity, both of which are safe to humans and would be less harmful to the environment when disposed, compared to conventional batteries.”

The research team has filed for a patent through NTUitive, NTU’s innovation and enterprise company. They are also working towards commercialising their invention.

Cry me a current

The team demonstrated their invention using a simulated human eye. The battery, which is about 0.5 millimetres-thin generates electrical power by reacting with the basal tears – the constant tears that create a thin film over our eyeballs – for the devices embedded within the lenses to function.

The flexible and flat battery discharges electricity through a process called reduction when its glucose oxidase coating reacts with the sodium and chloride ions in the tears, generating power and current within the contact lenses.

The team demonstrated that the battery could produce a current of 45 microamperes and a maximum power of 201 microwatts, which would be sufficient to power a smart contact lens.

Laboratory tests showed that the battery could be charged and discharged up to 200 times. Typical lithium-ion batteries have a lifespan of 300 to 500 charging cycles.

The team recommends that the battery should be placed for at least eight hours in a suitable solution that contains a high quantity of glucose, sodium and potassium ions, to be charged while the user is asleep.

Source: Nanyang Technology University