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Early treatment with the antiviral drug remdesivir has been found to reduce viral load and prevent lung disease in macaques infected with SARS-CoV-2 that causes COVID-19, according to a study.

The findings, published in the journal Nature on Tuesday, support the early use of remdesivir treatment in patients with COVID-19 to prevent progression to pneumonia.

Researchers from the National Institutes of Health in the US noted that remdesivir has broad antiviral activity and has been shown to be effective against infections with SARS-CoV and MERS-CoV in animal models.

The drug is being tested in human clinical trials for the treatment of COVID-19, they said.

Researcher Emmie de Wit and colleagues investigated the effects of remdesivir treatment in rhesus macaques, a recently established model of SARS-CoV-2 infection.

Two sets of six macaques were inoculated with SARS-CoV-2.

One group was treated with remdesivir 12 hours later -- close to the peak of virus reproduction in the lungs -- and these macaques received treatment every 24 hours until six days after inoculation.

In contrast to the control group, the researchers found that macaques that received remdesivir did not show signs of respiratory disease, and had reduced damage to the lungs.

Viral loads in the lower respiratory tract were also reduced in the treated animals; viral levels were around 100 times lower in the lower-respiratory tract of remdesivir-treated macaques 12 hours after the first dose, they said.

The researchers said that infectious virus could no longer be detected in the treatment group three days after initial infection, but was still detectable in four out of six control animals.

Despite this virus reduction in the lower respiratory tract, no reduction in virus shedding was observed, which indicates that clinical improvement may not equate to a lack of infectiousness, they said.

Dosing of remdesivir in the rhesus macaques is equivalent to that used in humans, the researchers noted.

They cautioned that it is difficult to directly translate the timing of treatment used in corresponding disease stages in humans, because rhesus macaques normally develop only mild disease.

However, researchers said the results indicate that remdesivir treatment of COVID-19 should be initiated as early as possible to achieve the maximum treatment effect.

Feb 22: The subjective feeling of well-being experienced by many people with the practice of meditation is associated with specific changes in the brain, according to a study which may lead to better clinical recommendations of the practice.

The study, published in the journal Brain and Cognition, examined the effects of the technique known as Transcendental Meditation (TM), which consists of the silent repetition of a meaningless sound.

In the study, the researchers from the IMT School for Advanced Studies Lucca in Italy, enrolled 34 healthy young volunteers and divided them in two groups.

They said the first group practised TM 40 minutes per day in two sessions of 20 minutes each, one in the morning and the other in the evening.

The second group, the scientists said, did not change its daily routine.

Using questionnaires, they also measured the anxiety and stress levels of all the participants at the beginning of the study, as well as the subjects' ability to manage stressful situations.

According to the researchers, the participants were also subjected to a functional magnetic resonance imaging (fMRI) brain scan, in order to measure the organ's activity at rest, and changes in the excitation among different cerebral areas.

They repeated the tests after three months, at the end of the study.

According to the study, the levels of anxiety and stress perceived by the subjects who followed the meditation program were significantly reduced in comparison with those of the volunteers who did not practice TM.

"Magnetic resonance imaging also shows that the reduction of anxiety levels is associated with specific changes in the connectivity between different cerebral areas, such as precuneus, left parietal lobe and insula, which all have an important role in the modulation of emotions and inner states," said study co-author Giulia Avvenuti from the IMT School for Advanced Studies Lucca.

"In the control group, instead, none of these changes was observed. The fact that Transcendental Meditation has measurable effects on the 'dialogue' between brain structures involved in the modulation of affective states opens new perspectives for the understanding of brain-mind relationships," said Pietro Pietrini, IMT School's Director, and co-author of the study.

"It also extends the results of recent research suggesting that drugs therapies and psychotherapy leverage on the same biological mechanism," Pietrini said.

According to the researchers, even a few months of practice of TM can have positive effects which can be correlated with measurable changes in the brain.

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.