India enters age of 3D printed body parts

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., Jan 12: Disruption in one night's sleep can lead to getting Alzheimer's disease, a recent study has stated.

The interruption in the sound sleep for a single night aggravates the level of tau protein in any young male's body, thus gives rise to the chances of developing the disease.

According to CNN, the report was published on Wednesday in neurology, the medical journal of the American Academy of Neurology.

"Our study focuses on the fact that even in young, healthy individuals, missing one night of sleep increases the level of tau in blood suggesting that over time, such sleep deprivation could possibly have detrimental effects," says study author Dr Jonathan Cedernaes, a neurologist at Uppsala University in Sweden.

As defined by the Alzheimer's Association, tau is the name of a protein that helps in stabilizing the internal structure of the brain's nerve cells. An abnormal build-up of tau protein in the body can end up in causing interior cells to fall apart and eventually developing Alzheimer's.

"When you get more of that deep sleep and you get the REM sleep in the normal amounts, that improves clearance of abnormal proteins which we think is good," said Mayo Clinic neurologist Dr Donn Dexter, not the study author but a fellow of the American Academy of Neurology.

Earlier studies have also shown that getting deprived of sleep can allow higher tau development and accumulation. Thus that poor sleep can hasten the development of cognitive issues.

Researchers caution that the study is small and inconclusive, and acknowledged they were not able to determine what the increased levels might mean.

"This study raises more questions than answers," agreed Dexter on a concluding note, sharing, "What this is telling us is that we have to dig more deeply. Despite something we do for a third of our lives, we know so little about sleep and we're learning every day, particularly when it comes to sleep and dementia."

The World Health Organisation on Wednesday said that anti-malarial drug hydroxychloroquine (HCQ) will return to the solidarity trial for the potential treatment of coronavirus disease.

At a press conference in the WHO headquarters in Geneva, Director General Tedros Adhanom Ghebreyesus said: "On the basis of the available mortality data, the members of the committee recommended that there are no reasons to modify the trial protocol. The Executive Group received this recommendation and endorsed continuation of all arms of the solidarity trial, including hydroxychloroquine."

The world health body had temporarily suspended the usage of HCQ from the solidarity trial for coronavirus treatment on May 25 soon after a study published in one of the most reliable medical journals, which had suggested that the drug could cause more fatalities among COVID-19 patients.

However, the WHO chief said that the decision was taken as a precaution while the safety data was reviewed.

Ghebreyesus also said that the Data Safety and Monitoring Committee will continue to closely monitor the safety of all therapeutics being tested in the solidarity trial.

"So far, more than 3,500 patients have been recruited in 35 countries. WHO is committed to accelerating the development of effective therapeutics, vaccines and diagnostics as part of our commitment to serving the world with science, solutions and solidarity," he said.

Soon after HCQ was suspended from the trial, the Indian government had said that the antimalarial drug has been known for its benefits for a long time and its usage will be continued on the frontline workers, including police and healthcare professionals, as prophylaxis. The government had also said that studies were being conducted and the drug would be included in the clinical trial also for the treatment of coronavirus disease.

US President Donald Trump also had strongly advocated the use of HCQ and called it a "game-changer". He went to the extent of saying that he had taken the medicine.

Launched by WHO and partners, solidarity trial is an international clinical trial to find an effective treatment for COVID-19, including drugs to slow the progression of the disease or improve survival. The trial, which enrols patients from different countries, "will compare four treatment options against standard of care to assess their relative effectiveness against COVID-19", said WHO.