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affect Mutations

Mutations that affect aging: More common than we thought? – Phys.org

Mutations that affect ageing - more common than we thought?
The researchers at Linköping University used fruit flies to study mutations that could contribute to ageing. Credit: Magnus Johansson/Linköping University

The number of mutations that can contribute to aging may be significantly higher than previously believed, according to new research on fruit flies. The study by scientists at Linköping University, Sweden, supports a new theory about the type of mutation that can lie behind aging. The results have been published in BMC Biology.

We live, we age and we die. Many functions of our bodies deteriorate slowly but surely as we age, and eventually an organism dies. This thought may not be very encouraging, but most of us have probably accepted that this is the fate of all living creatures—death is part of life. However, those who study find it far from clear why this is the case.

“The evolution of aging is, in a manner of speaking, a paradox. Evolution causes continuous adaptation in organisms, but even so it has not resulted in them ceasing to age,” says Urban Friberg, senior lecturer in the Department of Physics, Chemistry and Biology at Linköping University and leader of the study.

Nearly 70 years ago, evolutionary biologists proposed two theories concerning two different types of mutation that contribute to aging. Both of these have a as the organism becomes older—which leads to aging—while they are either advantageous or neutral early in life. Researchers have, however, not been able to determine which of the two types of mutation contributes most to aging, despite experimental studies.

A new was proposed a few years ago suggesting that aging is caused by mutations with a detrimental effect early in life, and whose negative effects increase with age. Those who support this hypothesis believe that many of the mutations that arise have negative effects right from the start, compared with the normal variant of a gene.

Mutations that affect ageing - more common than we thought?
Martin Iinatti Brengdahl, PhD student at Linköping University, examining fruit flies in a microscope. Credit: Magnus Johansson/Linköping University

The study now published describes experiments to test the theory of mutations that have a detrimental effect throughout life and contribute to aging. The authors used one of the most well-studied animals in the world, namely the fly, or Drosophila melanogaster. They tested 20 different mutations that they had placed into the genetic material of the flies. For each individual mutation, they studied a group of flies with the mutation and a control group without it. Each mutation had a specific, visible effect, which made it easy to follow, such as a somewhat different appearance of the wings or a different shape of the eyes.

As an organism ages, the probability that an individual dies increases, and its ability to reproduce falls. The researchers determined the fertility of the and used it as a measure of aging. They counted the number of eggs laid by each female early in life, after two weeks, and finally after a further two weeks (which is a ripe old age for a fruit fly!). The researchers wanted to see whether the difference between flies with the mutations and the control group changed as they aged. The results support the theory they were testing. Most of the mutations had a negative effect on the fertility of the fruit flies early in life, and most of them also caused reproductive aging to occur more rapidly.

“The results suggest that mutations that are detrimental early in life can also contribute to aging. Thus it may be that mutations that bring on aging are significantly more common than we previously believed,” says Martin Iinatti Brengdahl, doctoral student in the Department of Physics, Chemistry and Biology and principal author of the study.



More information:
“Deleterious mutations show increasing negative effects with age in Drosophila melanogaster”, Martin I. Brengdahl, Christopher M. Kimber, Phoebe Elias, Josephine Thompson and Urban Friberg, (2020), BMC Biology, published online 30 September, DOI: 10.1186/s12915-020-00858-5

Citation:
Mutations that affect aging: More common than we thought? (2020, September 29)
retrieved 30 September 2020
from https://phys.org/news/2020-09-mutations-affect-aging-common-thought.html

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affect Obesity

Obesity might affect how well a coronavirus vaccine works – Atlanta Journal Constitution

More than 150,000 people in the United States — nearly 4,000 of them in Georgia — have died from COVID-19, making the need for a vaccine urgent.

ExploreCoronavirus in Georgia: COVID-19 dashboard

Researchers from Emory University are working with a team to create a COVID-19 vaccine. Although their vaccine has showed positive results, more work is needed to be sure it is safe.

When a vaccine is found, it might not work for everyone, Sarah Varney writes for Kaiser Health News.

In the United States, the promise of a vaccine “is hampered by a vexing epidemic that long preceded Covid-19: obesity,” she wrote.

Studies have shown that flu, hepatitis B, tetanus and rabies vaccines can be less effective in obese adults than in the general population, and there’s no reason to believe a coronavirus vaccine will be any different.

ExploreTrained dogs able to detect COVID-19 with high accuracy

“Will we have a Covid vaccine next year tailored to the obese? No way,” Raz Shaikh, an associate professor of nutrition at the University of North Carolina-Chapel Hill, told Varney.

“Will it still work in the obese? Our prediction is no.”

According to the Centers for Disease Control and Prevention in Atlanta, 30-35% of Georgia’s adults are obese, meaning their body mass index, or BMI, is 30 or higher.

The CDC initially warned that people who were morbidly obese —having a BMI of 40 or more or were about 100 pounds overweight — were among the groups at highest risk of becoming severely ill with COVID-19.

It wasn’t long before that warning was expanded to include people with a body mass index of 30 or more.

How does obesity prevent vaccines from working correctly?

According to Varney: “A healthy immune system turns inflammation on and off as needed, calling on white blood cells and sending out proteins to fight infection. Vaccines harness that inflammatory response. But blood tests show that obese people and people with related metabolic risk factors such as high blood pressure and elevated blood sugar levels experience a state of chronic mild inflammation; the inflammation turns on and stays on.”

Although scientists are still researching its causes, it seems chronic inflammation interferes with the body’s immune response to vaccines.

“Obesity is a serious global problem, and the suboptimal vaccine-induced immune responses observed in the obese population cannot be ignored,” researchers from the Mayo Clinic’s Vaccine Research Group wrote in a 2015 study published in the journal Vaccine.

ExploreTips for wearing a face mask during Georgia’s hot months

Obese individuals shouldn’t take this information to mean there is no point in getting a coronavirus vaccination, however.

Dr. Timothy Garvey, an endocrinologist and director of diabetes research at the University of Alabama at Birmingham, said it’s still safer for obese people to get vaccinated than not.

“The influenza vaccine still works in patients with obesity, but just not as well,” he said. “We still want them to get vaccinated.”

ExploreGeorgia city among places with highest percentage of overweight adults

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affect Blood

How blood type may affect your coronavirus risk – NBC News

Recent studies have suggested that people’s blood types may affect their risk of contracting the COVID-19 virus or developing a serious case of the disease. Overall, the findings indicate that people with Type O blood seem to be more protected and that those with Type A appear more vulnerable.

So does that mean some people can slack off on preventive measures while others need to ratchet them up?

Not so fast, say doctors who point out that the findings show associations, not causation — and don’t indicate that any particular blood type guarantees protection.

While the findings may catch the public’s attention at a time when people fatigued by the pandemic are looking for signs of hope, doctors say the results are more relevant to researchers trying to better understand the virus.

“I think something like this has much more sex appeal than it does real practical value,” said Dr. Aaron Glatt, chair of medicine and chief of infectious diseases at Mount Sinai South Nassau in New York.

Everybody should practice exactly the same way, whatever your blood type is, in terms of appropriate masking and social distancing.

Any possible influence of blood type on COVID-19 appears small compared with the substantial impact of known risk factors, such as older age and underlying health conditions, said Glatt, who is a spokesperson for the Infectious Diseases Society of America. “In any individual patient, if they have risk factors or they don’t have risk factors, that is far, far more important,” he said.

People shouldn’t jump to conclusions that they are safer or not because of their blood types, he said.

“They certainly shouldn’t walk around high-fiving and saying, ‘I can do whatever I want, I don’t have to mask, I don’t have to worry about anything because I have O,'” Glatt said. “And they shouldn’t crawl into a corner of the world and not let anyone near them because they have A. Everybody should practice exactly the same way, whatever your blood type is, in terms of appropriate masking and social distancing.”

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Dr. Lewis Kaplan, a professor of surgery at the University of Pennsylvania who is president of the Society of Critical Care Medicine, agreed.

Even if some people have reduced risks based on blood type — and the risks vary by study — they don’t have zero risk, Kaplan said. “It might mean they have less risk, but if you engage in risky behavior, we don’t know just how much risk you need to incur to overwhelm whatever potential protection you might have,” he said. “We have no clue.”

A European study published last month in the New England Journal of Medicine found that people with Type A blood were 45 percent more likely to develop severe COVID-19 requiring oxygen supplementation or a ventilator than people with other blood types and that those with Type O blood were 35 percent less likely. The study involved 1,610 patients with severe COVID-19 and 2,205 control subjects.

But people with Type O can still get very sick.

“They have a decreased risk to get infected and to develop severe disease,” study author Andre Franke, a professor of molecular medicine at the University of Kiel in Germany, said in an email. “However, this is only a relative risk reduction, i.e. there is no full protection. Among our patients who died there were also many with blood group O.”

A couple of related papers have been released on the preprint server medRxiv without the peer review scrutiny that published papers typically receive. Studies in China and New York both found that people with Type A blood had a greater risk of coronavirus infection than those with other blood types, while those with Type O had a lower risk.

And the gene testing company 23andMe wrote a blog post about preliminary unpublished data suggesting that people with Type O blood were less likely to test positive for the coronavirus than others.

Dr. Roy Silverstein, a professor and chair of medicine at the Medical College of Wisconsin who is senior investigator at Versiti Blood Center of Wisconsin, cautioned against putting too much weight on findings that haven’t been peer-reviewed and said more research is needed.

“We have to be careful about overreacting,” Silverstein said.

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Blood types O and A are most common, so the studies were able to draw stronger statistical conclusions about those types than B and AB, he said.

An explanation for the findings isn’t known, but there is speculation that blood type may affect clotting or other factors in COVID-19 patients or somehow affect infectivity or immunity. The hope is that the findings can be applied to future research to better understand why the coronavirus affects people differently and to develop treatments.

The results aren’t expected to alter how doctors care for patients now.

“The fact that you have O or A is not going to change one iota how we monitor a patient,” said Glatt, of Mount Sinai South Nassau. “If somebody has O and they’re not doing well, I’m not going to say, ‘Oh, don’t worry about it, you have O.’ I would treat them appropriately. And if they have A and they’re doing very well, I would say, ‘OK, we’re going to continue to watch you.'”

Jacqueline Stenson

NBC News contributor Jacqueline Stenson is a health and fitness journalist who has written for the Los Angeles Times, Reuters, Health, Self and Shape, among others. She also teaches at the UCLA Extension Writers’ Program.

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