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.

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Agencies
May 26,2020

Tedros Adhanom Ghebreyesus, the World Health Organisation's (WHO) Director-General, said that a clinical trial of hydroxychloroquine (HCQ) on COVID-19 patients has come to "a temporary pause", while the safety data of the the anti-malaria drug was being reviewed.

According to the WHO chief, The Lancet medical journal on May 22 had published an observational study on HCQ and chloroquine and its effects on COVID-19 patients that have been hospitalized, reports Xinhua news agency.

The authors of the study reported that among patients receiving the drug, when used alone or with a macrolide, they estimated a higher mortality rate.

"The Executive Group of the Solidarity Trial, representing 10 of the participating countries, met on Saturday (May 23) and has agreed to review a comprehensive analysis and critical appraisal of all evidence available globally," Tedros said in a virtual press conference on Monday.

The review will consider data collected so far in the Solidarity Trial and in particular robust randomized available data, to adequately evaluate the potential benefits and harms from this drug, he said.

"The Executive Group has implemented a temporary pause of the HCQ arm within the Solidarity Trial while the safety data is reviewed by the Data Safety Monitoring Board. The other arms of the trial are continuing," Tedros added.

WHO initiated the Solidarity Trial, a plan to evaluate the safety and efficacy of four drugs and drug combinations against COVID-19 more than two months ago, which include HCQ.

According to the WHO, over 400 hospitals in 35 countries are actively recruiting patients and nearly 3,500 patients have been enrolled from 17 countries under the Solidarity Trial.

Tedros added that the safety concern over the drug related only to the use of HCQ and chloroquine in COVID-19, and "these drugs are accepted as generally safe for use in patients with autoimmune diseases or malaria".

"WHO will provide further updates as we know more," he added.

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Agencies
May 8,2020

As Europe and the US loosen their lockdowns against the coronavirus, health experts are expressing growing dread over what they say is an all-but-certain second wave of deaths and infections that could force governments to clamp back down.

"We are risking a backslide that will be intolerable," said Dr Ian Lipkin of Columbia University's Center for Infection and Immunity.

Around the world, German authorities began drawing up plans in case of a resurgence of the virus. Experts in Italy urged intensified efforts to identify new victims and trace their contacts. And France, which has not yet eased its lockdown, has already worked up a "reconfinement plan" in the event of a new wave.

"There will be a second wave, but the problem is to which extent. Is it a small wave or a big wave? It is too early to say," said Olivier Schwartz, head of the virus unit at France's Pasteur Institute.

In the US, with about half of the states easing their shutdowns to get their economies restarted and cellphone data showing that people are becoming restless and increasingly leaving home, public health authorities are worried.

Many states have not put in place the robust testing that experts believe is necessary to detect and contain new outbreaks. And many governors have pressed ahead before their states met one of the key benchmarks in the Trump administration's guidelines for reopening -- a 14-day downward trajectory in new illnesses and infections.

"If we relax these measures without having the proper public health safeguards in place, we can expect many more cases and, unfortunately, more deaths," said Josh Michaud, associate director of global health policy with the Kaiser Family Foundation in Washington.

Cases have continued to rise steadily in places such as Iowa and Missouri since the governors began reopening, while new infections have yo-yoed in Georgia, Tennessee and Texas.

Lipkin said he is most worried about two things: the reopening of bars, where people crowd together and lose their inhibitions, and large gatherings such as sporting events, concerts and plays. Preventing outbreaks will require aggressive contact tracing powered by armies of public health workers hundreds of thousands of people strong, which the US does not yet have, Lipkin said.

Worldwide the virus has infected more than 36 lakh people and killed over a quarter-million, according to a tally by Johns Hopkins University that experts agree understates the dimensions of the disaster because of limited testing, differences in counting the dead and concealment by some governments.

The US has recorded over 70,000 deaths and 12 lakh confirmed infections, while Europe has reported over 140,000 dead.

This week, the researchers behind a widely cited model from the University of Washington nearly doubled their projection of deaths in the US to around 134,000 through early August, in large part because of the easing of state stay-at-home restrictions. Newly confirmed infections per day in the US exceed 20,000 and deaths per day are running well over 1,000.

In hard-hit New York City, which has managed to bring down deaths dramatically even as confirmed infections continue to rise around the rest of the country, Mayor Bill de Blasio warned that some states may be reopening too quickly.

"My message to the rest of the country is learn from how much effort, how much discipline it took to finally bring these numbers down and follow the same path until you are sure that it is being beaten back," he said on CNN, "or else, if this thing boomerangs, you are putting off any kind of restart or recovery a hell of a lot longer."

A century ago, the Spanish flu epidemic's second wave was far deadlier than its first, in part because authorities allowed mass gatherings from Philadelphia to San Francisco.

"It is clear to me that we are in a critical moment of this fight. We risk complacency and accepting the preventable deaths of 2,000 Americans each day," epidemiologist Caitlin Rivers, a professor at Johns Hopkins, told a House subcommittee in Washington.

President Donald Trump, who has pressed hard to ease the restrictions that have throttled the economy and thrown more than three crore Americans out of work, pulled back Wednesday on White House plans revealed a day earlier to wind down the coronavirus task force.

He tweeted that the task force will continue meeting indefinitely with a "focus on SAFETY & OPENING UP OUR COUNTRY AGAIN".

Underscoring those economic concerns, the European Union predicted the worst recession in its quarter-century history. And the US unemployment rate for April, which comes out on Friday, is expected to hit a staggering 16 per cent, a level last seen during the Great Depression of the 1930s.

Governors continue to face demands, even lawsuits, to reopen. In Michigan, where armed demonstrators entered the Capitol last week, the Republican-led Legislature sued Democratic Governor Gretchen Whitmer, asking a judge to declare invalid her stay-at-home order, which runs at least through May 15.

In hard-hit Italy, which has begun easing restrictions, Dr Silvio Brusaferro, president of the Superior Institute of Health, urged "a huge investment" of resources to train medical personnel to monitor possible new cases of the virus, which has killed about 30,000 people nationwide.

He said that contact-tracing apps which are being built by dozens of countries and companies are not enough to manage future waves of infection.

German Chancellor Angela Merkel said after meeting with the country's 16 governors that restaurants and other businesses will be allowed to reopen in the coming weeks but that regional authorities will have to draw up a "restriction concept" for any county that reports 50 new cases for every 100,000 inhabitants within a week.

Lothar Wieler, head of Germany's national disease control centre, said scientists "know with great certainty that there will be a second wave" of infections.

Britain, with over 30,000 dead, the second-highest death toll in the world behind the US, plans to extend its lockdown but has begun recruiting 18,000 people to trace contacts of those infected.

In other developments, the US Centers for Disease Control and Prevention said nearly 5,000 coronavirus illnesses and at least 88 deaths have been reported among inmates in American jails and prisons. An additional 2,800 cases and 15 deaths were reported among guards and other staff members.

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Agencies
June 27,2020

After admitting that the world may have a COVID-19 vaccine within one year or even a few months earlier, the World Health Organisation (WHO) on Friday said that UK-based AstraZeneca is leading the vaccine race while US-based pharmaceutical major Moderna is not far behind.

WHO Chief Scientist Soumya Swaminathan stated that the AstraZeneca's coronavirus vaccine candidate is the most advanced vaccine currently in terms of development.

"I think AstraZeneca certainly has a more global scope at the moment in terms of where they are doing and planning their vaccine trials," she told the media.

AstraZeneca's Covid-19 vaccine candidate developed by researchers from the Oxford University will likely provide protection against the disease for one year, the British drug maker's CEO told Belgian radio station Bel RTL this month.

The Oxford University last month announced the start of a Phase II/III UK trial of the vaccine, named AZD1222 (formerly known as ChAdOx1 nCoV-19), in about 10,000 adult volunteers. Other late-stage trials are due to begin in a number of countries.

Last week, Swaminathan had said that nearly 2 billion doses of the COVID-19 vaccine would be ready by the end of next year.

Addressing the media from Geneva, she said that "at the moment, we do not have a proven vaccine but if we are lucky, there will be one or two successful candidates before the end of this year" and 2 billion doses by the end of next year.

Scientists predict that the world may have a COVID-19 vaccine within one year or even a few months earlier, said the Director-General of the World Health Organization even as he underlined the importance of global cooperation to develop, manufacture and distribute the vaccines.

However, making the vaccine available and distributing it to all will be a challenge and will require political will, WHO chief Tedros Adhanom Ghebreyesus said on Thursday during a meeting with the European Parliament's Committee for Environment, Public Health and Food Safety.

One option would be to give the vaccine only to those who are most vulnerable to the virus.

There are currently over 100 COVID-19 vaccine candidates in various stages of development.

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