Multiple exposures to anaesthesia may affect your child’s memory

Agencies
June 1, 2017

Jun 1: A recent study has found that repeated exposure to a common anaesthesia drug early in life results in visual recognition memory impairment, which emerges after the first year of life and may persist long-term.child

The research from the Icahn School of Medicine at Mount Sinai is among the first to address the question of whether repeated postnatal anaesthesia exposure, in and of itself, results in memory impairment in a highly translationally relevant rhesus monkey model.

Rhesus monkeys at birth are at a stage of neurodevelopment that is more similar to that of human infants than are neonatal rodents; with respect to brain growth, a six-week-old rhesus monkey corresponds to a human 6 to 12 months of age.

Because these kinds of controlled studies cannot be carried out in humans, it is essential to use a comparable animal model to discover if anaesthesia is affecting the brain. Unlike previous research, the study was conducted in the absence of a surgical procedure, co-morbidities that may necessitate surgical intervention, or the psychological stress associated with illness.

“The major strength of this study is its ability to separate anaesthesia exposure from surgical procedures, which is a potential complication in the studies conducted in children,” said researcher Mark Baxter. “Our results confirm that multiple anaesthesia exposures alone result in memory impairment in a highly translational animal model. Interestingly, the anaesthesia-exposed group had normal visual memory at six months of age. Visual memory impairment didn’t emerge until the second year of life, corresponding roughly to the age of three to six years old in humans.”

Specifically, the study team exposed 10 non-human primate subjects to a common paediatric aesthetic called sevoflurane for four hours, the length of time required for a significant surgical procedure in humans. They were exposed to the aesthetic at postnatal day 7 and then again two and four weeks later, because human data indicate that repeated anaesthesia results in a greater risk of cognitive disability relative to a single aesthetic exposure.

They found the anaesthesia-exposed infants displayed no memory impairment when tested at 6-10 months, but demonstrated significant memory impairment (reduced time looking at the novel image) after the first year of life compared with the control group.

This primate model may be used by researchers for future studies to develop a new aesthetic agent or prophylactic treatment to counteract the impact of anaesthesia on behaviour in children. The findings also suggest that additional work is required to identify the mechanisms by which anaesthetics may cause long-term changes in central nervous system function that impact behaviour.

The study is published in The British Journal of Anaesthesia.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
January 11,2020

Europe, Jan 11: Researchers have revealed the people who drink tea at least three times a week have healthy years of life and longer life expectancy.

The research was published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

Dr Xinyan Wang, who is the author of the study, said: "Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death. The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers."
The analysis that was conducted included about 100,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer.

Participants were classified into two groups: Habitual tea drinkers and never or non-habitual tea drinkers and followed-up for a median of 7.3 years.

The analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea. Compared with never or non-habitual tea drinkers, the habitual tea consumers had a 20 per cent lower risk of incident heart disease and stroke, 22 per cent lower risk of fatal heart disease and stroke, and 15 per cent decreased risk of all-cause death.

The potential influence of changes in tea drinking behaviour was suspected in a subset of 14,081 participants with assessments at two-time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.

Habitual tea drinkers who maintained their habit in both surveys had a 39 per cent lower risk of incident heart disease and stroke, 56 per cent lower risk of fatal heart disease and stroke, and 29 per cent decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Senior author Dr Dongfeng Gu said: "The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."

In a subanalysis by type of tea, drinking green tea was linked with approximately 25 per cent lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.
Dr Gu noted that a preference for green tea is unique to East Asia.

Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process, polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function.

Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. Dr Wang said: "One reason might be that 48 per cent of men were habitual tea consumers compared to just 20 per cent of women. Secondly, women had a much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men."

She said: "The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced."

In conclusion, the authors have found that randomised trials are required to validate the results and to illustrate nutritional guidelines and advice for lifestyle.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
July 15,2020

The first COVID-19 vaccine tested in the US revved up people's immune systems just the way scientists had hoped, researchers reported Tuesday -- as the shots are poised to begin key final testing.

No matter how you slice this, this is good news, Dr. Anthony Fauci, the U.S. government's top infectious disease expert, told The Associated Press.

The experimental vaccine, developed by Fauci's colleagues at the National Institutes of Health and Moderna Inc., will start its most important step around July 27: A 30,000-person study to prove if the shots really are strong enough to protect against the coronavirus.

But Tuesday, researchers reported anxiously awaited findings from the first 45 volunteers who rolled up their sleeves back in March. Sure enough, the vaccine provided a hoped-for immune boost.

Those early volunteers developed what are called neutralizing antibodies in their bloodstream -- molecules key to blocking infection -- at levels comparable to those found in people who survived COVID-19, the research team reported in the New England Journal of Medicine.

This is an essential building block that is needed to move forward with the trials that could actually determine whether the vaccine does protect against infection, said Dr. Lisa Jackson of the Kaiser Permanente Washington Research Institute in Seattle, who led the study.

There's no guarantee but the government hopes to have results around the end of the year -- record-setting speed for developing a vaccine.

The vaccine requires two doses, a month apart.

There were no serious side effects. But more than half the study participants reported flu-like reactions to the shots that aren't uncommon with other vaccines -- fatigue, headache, chills, fever and pain at the injection site. For three participants given the highest dose, those reactions were more severe; that dose isn't being pursued.

Some of those reactions are similar to coronavirus symptoms but they're temporary, lasting about a day and occur right after vaccination, researchers noted.

Small price to pay for protection against COVID, said Dr. William Schaffner of Vanderbilt University Medical Center, a vaccine expert who wasn't involved with the study.

He called the early results a good first step, and is optimistic that final testing could deliver answers about whether it's really safe and effective by the beginning of next year.

It would be wonderful. But that assumes everything's working right on schedule, Schaffner cautioned.

Moderna's share price jumped nearly 15 percent in trading after US markets closed. Shares of the company, based in Cambridge, Massachusetts, have nearly quadrupled this year.

Tuesday's results only included younger adults. The first-step testing later was expanded to include dozens of older adults, the age group most at risk from COVID-19.

Those results aren't public yet but regulators are evaluating them. Fauci said final testing will include older adults, as well as people with chronic health conditions that make them more vulnerable to the virus and Black and Latino populations likewise affected.

Nearly two dozen possible COVID-19 vaccines are in various stages of testing around the world. Candidates from China and Britain's Oxford University also are entering final testing stages.

The 30,000-person study will mark the world's largest study of a potential COVID-19 vaccine so far. And the NIH-developed shot isn't the only one set for such massive U.S. testing, crucial to spot rare side effects. The government plans similar large studies of the Oxford candidate and another by Johnson & Johnson; separately, Pfizer Inc. is planning its own huge study.

Already, people can start signing up to volunteer for the different studies.

People think this is a race for one winner. Me, I'm cheering every one of them on, said Fauci, who directs NIH's National Institute of Allergy and Infectious Diseases.

We need multiple vaccines. We need vaccines for the world, not only for our own country. Around the world, governments are investing in stockpiles of hundreds of millions of doses of the different candidates, in hopes of speedily starting inoculations if any are proven to work.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
February 26,2020

Feb 26: While too much stress can be toxic to your health, a new study suggests that despite its negative side effects, it may also lead to a surprising social benefit.

The research, published in the journal Stress & Health, found that experiencing stress made people both more likely to give and receive emotional support from another person.

This was true on the day they experienced the stressor as well as the following day.

"Our findings suggest that just because we have a bad day, that doesn't mean it has to be completely unhealthy," said study researcher David Almeida from Penn State University in the US.

"If stress can actually connect us with other people, which I think is absolutely vital to the human experience, I think that's a benefit. Stress could potentially help people deal with negative situations by driving them to be with other people," Almeida added.

For the study, the researchers interviewed 1,622 participants every night for eight nights. They asked the participants about their stressors and whether they gave or received emotional support on that day.

Stressors included arguments, stressful events at work or school, and stressful events at home.

The researchers found that on average, participants were more than twice as likely to either give or receive emotional support on days they experienced a stressor.

Additionally, they were 26 per cent more likely to give or receive support the following day.

The researchers said that while this effect, on average, was found across the participants, it differed slightly between men and women.

"Women tended to engage in more giving and receiving emotional support than men," said study researcher Hye Won Chai.

"In our study, men were also more likely to engage in emotional support on days they were stressed, but to a lesser extent than women," Chai added.

The researchers said they were surprised that stress was linked to people not just receiving emotional support, but giving it, as well.

"We saw that someone experiencing a stressor today actually predicted them giving emotional support the next day," Almeida said.

"This made me think that it's actually possible that stress helps to drive you to other people and allows it to be ok to talk about problems -- your problems, my problems," Almeida added.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.