Eating like your ancestors may boost health: study

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections, say scientists who have decoded the mechanisms, symptoms, and diagnosis of the disease caused by the SARS-Cov-2 coronavirus.

In a study published in the journal Frontiers in Public Health, the researchers explained step-by-step how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defences to overshoot with a "cytokine storm".

This storm is an over-activation of white blood cells, which release too-great amounts of cytokines -- inflammation-stimulating molecules --into the blood, they said.

"Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome," said study author Daishun Liu, Professor at Zunyi Medical University in China.

"The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus cause lung injury," Liu said.

The researchers explained that the cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, and blood clotting inside the body.

It also causes extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs, they said.

The researchers noted that white blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals.

This multiple organ dysfunction syndrome (MODS) may worsen and shutdown the lungs, a condition called acute respiratory distress syndrome, (ARDS), they said.

This, the researchers explained, happens due to the formation of a so-called hyaline membrane -- composed of debris of proteins and dead cells -- lining the lungs, which makes absorption of oxygen difficult.

Most deaths due to COVID-19 are therefore due to respiratory failure, they said.

The researchers explained that in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to the fight the symptoms, and lowering the mortality rate through intensive maintenance of organ function.

For example, an artificial liver blood purification system or renal replacement therapy can be used to filter the blood through mechanical means, they said.

The team noted that especially important are methods to supplement or replace lung function, for example with non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe, the administration of heated and humidified oxygen via a tube in the nose, or a heart-lung bypass.

The researchers stressed the importance of preventing secondary infections.

They noted that SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms.

The researchers advocate that this should be prevented with nutritional support, for example with probiotics -- beneficial bacteria that protect against the establishment of harmful ones -- and nutrients and amino acids to improve the immune defences and function of the intestine.

"Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition," Liu added.

Washington D.C, Feb 10: Children's vulnerability towards depression, anxiety, impulsive behaviour, and poor cognitive performance could be determined by considering the hours of sleep they manage to get.

Sleep states are active processes that support the reorganisation of brain circuitry. This makes sleep especially important for children, whose brains are developing and reorganising rapidly.

In a study by researchers from the University of Warwick -- recently published in the journal Molecular Psychiatry -- cases of 11,000 children aged between 9 and 11 years from the Adolescent Brain Cognitive Development dataset were analyzed to find out the relationship between sleep duration and brain structure.

The study was carried out by researchers Professor Jianfeng Feng, Professor Edmund Rolls, Dr. Wei Cheng and colleagues from the University of Warwick's Department of Computer Science and Fudan University.

Measures of depression, anxiety, impulsive behaviour and poor cognitive performance in the children were associated with shorter sleep duration. Moreover, the depressive problems were associated with short sleep duration one year later.

The reduced brain volume of areas such as orbitofrontal cortex, prefrontal, and temporal cortex, precuneus, and supramarginal gyrus was found to be associated with the shorter sleep duration.

Professor Jianfeng Feng, from the University of Warwick's Department of Computer Science, comments: "The recommended amount of sleep for children 6 to 12 years of age is 9-12 hours. However, sleep disturbances are common among children and adolescents around the world due to the increasing demand on their time from school, increased screen time use, and sports and social activities."

A previous study showed that about 60 per cent of adolescents in the United States receive less than eight hours of sleep on school nights.

Professor Jianfeng Feng further added: "Our findings showed that the total score for behavior problems in children with less than 7 hours sleep was 53 per cent higher on average and the cognitive total score was 7.8 per cent lower on average than for children with 9-11 hours of sleep. It highlights the importance of enough sleep in both cognition and mental health in children."

Professor Edmund Rolls from the University of Warwick's Department of Computer Science also commented: "These are important associations that have been identified between sleep duration in children, brain structure, and cognitive and mental health measures, but further research is needed to discover the underlying reasons for these relationships."

UN, Jul 14: There will be no return to the "old normal" for the foreseeable future as a result of the ongoing COVID-19 pandemic, and too many countries were still headed in the wrong direction, the chief of the World Health Organization (WHO) warned.

"The virus remains public enemy number one, but the actions of many governments and people do not reflect this," Xinhua news agency quoted WHO Director-General Tedros Adhanom Ghebreyesus at as saying a regular briefing on Monday.

He noted that mixed messages from leaders are undermining trust, which is the most critical ingredient of any response, while the only aim of the virus is to find people to infect.

Things are going to "get worse and worse and worse", he warned, unless governments communicate clearly with their citizens and roll out a comprehensive strategy focused on suppressing transmission and saving lives, while populations follow the basic public health principles of physical distancing, hand washing, wearing masks, coughing etiquette and staying home when sick.

COVID-19 has been gaining its momentum lately.

According to Tedros, Sunday saw a record of 230,000 cases reported to WHO, of which almost 80% were from just 10 countries and about half from just two countries.

"But it does not have to be this way," he said, asking every single leader, government and individual "to do their bit to break the chains of COVID-19 transmission and end the collective suffering".

To control the disease and get on with people's lives, Tedros said, three things are required. The first is to focus on reducing mortality and suppressing transmission; the second is to focus on an empowered, engaged community that takes individual behaviour measures in the interest of each other.

And the third is a strong government leadership and coordination of comprehensive strategies that are communicated clearly and consistently.

"We weren't prepared collectively, but we must use all the tools we have to bring this pandemic under control. And we need to do it right now," he added.

At the WHO briefing on Monday, health experts also said there was evidence to suggest that children under the age of 10 were only very mildly affected by Covid-19, while those over 10 seemed to suffer similar mild symptoms to young adults.

To what extent children can transmit the virus, while it appears to be low, remains unknown.

On Tuesday, the number of global coronavirus cases cross the 13 million mark, according to the Johns Hopkins University.

The total number of cases currently stood at 13,070,097, while the fatalities rose to 572,411, the University's Center for Systems Science and Engineering (CSSE) revealed in its latest update.

The US accounted for the world's highest number of infections and fatalities at 3,363,056 and 135,605, respectively, according to the CSSE.

Brazil came in the second place with 1,884,967 infections and 72,833 deaths.