Study reveals even small amounts of antibiotics can cause resistance

Agencies
April 24, 2018

Even low concentrations of antibiotics can cause high antibiotic resistance in bacteria, a growing problem in global health care, according to a study.

In the study published in the journal Nature Communications, researchers investigated how prolonged exposure to low levels of antibiotics contributes to the development of bacterial antibiotic resistance.

“The results are interesting because they show that the very low antibiotic concentrations present in many environments, too, can lead to a high degree of resistance and contribute to the problem of resistance,” said Dan I Andersson, a professor at Uppsala University in Sweden.

During a course of antibiotics, a high proportion of the antibiotic dose is excreted in the urine in unchanged, active form, and can then spread into watercourses, lakes and soil in the wastewater.

Consequently, these environments may contain low levels of antibiotics, researchers said.

In some parts of the world, large quantities of antibiotics are used in meat production and aquaculture, where small doses of antibiotics are added to the animal feed to make the animals grow faster, they said.

This means that the bacteria in their intestines are exposed to low levels of antibiotics over long periods and these bacteria can then, in turn, infect people via food, for example.

The researchers show that low concentrations of antibiotics, too, play a major part in the development of resistance.

The study showed that, over time, bacteria exposed to low doses of antibiotics developed resistance to antibiotic levels that were more than a thousand times higher than the initial level to which the bacteria were subjected.

It was also found that the mutations in the bacterial DNA that cause resistance are of a different type than if they have been exposed to high doses.

During the experiment, the bacteria eventually acquired several mutations. Each of these yielded low resistance, but together they brought about very high resistance.

In addition, the mutations took place mainly in genes that have not previously been regarded as typical resistance genes, suggesting that the number of genes capable of promoting development of resistance has been greatly underestimated.

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Agencies
February 11,2020

Using smartphone for long hours every day may do you more harm than you can probably think of. Researchers have found that spending a lot of time with the device and on social media may lead to mental distress and suicidality among adolescents.

The findings, published in the journal CMAJ (Canadian Medical Association Journal) contains guidance for physicians, parents and teachers on how to help teenagers manage smartphone and social media use for a healthy balance between sleep, academic work, social activity, interpersonal relationships and online activity.

"Physicians, teachers and families need to work together with youth to decrease possible harmful effects of smartphones and social media on their relationships, sense of self, sleep, academic performance, and emotional well-being," said lead author of the study Elia Abi-Jaoude from Toronto Western Hospital in Canada.

This review of evidence, led by the Hospital for Sick Children (SickKids), focuses on smartphone use and does not consider online gaming.

"For adolescents today, who have not known a world without social media, digital interactions are the norm, and the potential benefits of online access to productive mental health information -- including media literacy, creativity, self-expression, sense of belonging and civic engagement -- as well as low barriers to resources such as crisis lines and Internet-based talking therapies cannot be discounted," the authors wrote.

The researchers recommend that doctors should ask teenagers to reduce social media use rather than eradicate it completely and encourage parents to be part of the conversations.

Parents should discuss appropriate smartphone use with teenagers to determine together how to reduce risks and set boundaries.

A recent poll from the US indicates that 54 per cent of teenagers think they spend too much time on their smartphones and about half said they were cutting back on usage.

"Encouragingly, youth are increasingly recognising the negative impact of social media on their lives and starting to take steps to mitigate it," the authors wrote.

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Agencies
July 3,2020

Apart from the many benefits of doing exercise, new research has now found that exercise can slow down or prevent the development of macular degeneration and may benefit other common causes of vision loss, such as glaucoma and diabetic retinopathy.

The new study from the University of Virginia School of Medicine found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45 per cent. This tangle of blood vessels is a key contributor to macular degeneration and several other eye diseases.

The study represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration, a leading cause of vision loss, the scientists report. Ten million Americans are estimated to have the condition.

"There has long been a question about whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. The way that question has historically been answered has been by taking surveys of people, asking them what they are eating and how much exercise they are performing," said researcher Bradley Gelfand, PhD, of UVA's Center for Advanced Vision Science.

"That is basically the most sophisticated study that has been done. The problem with that is that people are notoriously bad self-reporters ... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for the very first time," Gelfand added.

Enticingly, the research found that the bar for receiving the benefits from exercise was relatively low - more exercise didn't mean more benefit.

"Mice are kind of like people in that they will do a spectrum of exercise. As long as they had a wheel and ran on it, there was a benefit. The benefit that they obtained is saturated at low levels of exercise," Gelfand said.

An initial test comparing mice that voluntarily exercised versus those that did not found that exercise reduced the blood vessel overgrowth by 45%. A second test, to confirm the findings, found a reduction of 32 per cent.

The scientists aren't certain exactly how exercise is preventing the blood vessel overgrowth. There could be a variety of factors at play, they say, including increased blood flow to the eyes.

Gelfand, of UVA's Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with a decrease in exercise.

"It is fairly well known that as people's eyes and vision deteriorate, their tendency to engage in physical activity also goes down. It can be a challenging thing to study with older people. ... How much of that is one causing the other?" he said.
The researchers already have submitted grant proposals in hopes of obtaining funding to pursue their findings further.

"The next step is to look at how and why this happens, and to see if we can develop a pill or method that will give you the benefits of exercise without having to exercise," Gelfand said.

He explained, "We're talking about a fairly elderly population [of people with macular degeneration], many of whom may not be capable of conducting the type of exercise regimen that may be required to see some kind of benefit." (He urged people to consult their doctors before beginning any aggressive exercise program.)
Gelfand, a self-described couch potato, disclosed a secret motivation for the research: "One reason I wanted to do this study was sort of selfish. I was hoping to find some reason not to exercise," he joked. "It turned out exercise really is good for you."

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News Network
February 12,2020

Washington, Feb 12: People who are optimistic may contribute to the health of their partners, staving off the risk factors leading to Alzheimer's disease, dementia and cognitive decline as they grow old together, according to a study.

The research, published in the Journal of Personality, followed nearly 4,500 heterosexual couples from the US Health and Retirement Study for up to eight years.

The researchers found a potential link between being married to an optimistic person and preventing the onset of cognitive decline, due to a healthier environment at home.

"We spend a lot of time with our partners.They might encourage us to exercise, eat healthier or remind us to take our medicine," said William Chopik, an assistant professor at the Michigan State University in the US.

"When your partner is optimistic and healthy, it can translate to similar outcomes in your own life. You actually do experience a rosier future by living longer and staving off cognitive illnesses," Chopik said.

An optimistic partner may encourage eating healthy foods, or working out together to develop healthier lifestyles, the researchers said.

For example, if a person quits smoking or starts exercising, their partner is close to following suit, they said.

"We found that when you look at the risk factors for what predicts things like Alzheimer's disease or dementia, a lot of them are things like living a healthy lifestyle," Chopik said.

"Maintaining a healthy weight and physical activity are large predictors.There are some physiological markers as well. It looks like people who are married to optimists tend to score better on all of those metrics," he said.

The researchers said there is a sense where optimists lead by example, and their partners follow their lead.

They also suggest that when couples recall shared experiences together, richer details from the memories emerge.

Chopik noted while there is a heritable component to optimism, there is some evidence to suggest that it's a trainable quality.

"There are studies that show people have the power to change their personalities, as long as they engage in things that make them change," Chopik said.

"Part of it is wanting to change. There are also intervention programs that suggest you can build up optimism," he added.

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