Doctors bust cancer myths to create awareness

New York, May 19: Cigarette smoke spurs the lungs to make more of the receptor protein which the novel coronavirus uses to enter human cells, according to a study which suggests that quitting smoking might reduce the risk of a severe coronavirus infection.

The findings, published in the journal Developmental Cell, may explain why smokers appear to be particularly vulnerable to severe COVID-19 disease.

"Our results provide a clue as to why smokers who develop COVID-19 tend to have poor clinical outcomes," said study senior author Jason Sheltzer, a cancer geneticist at Cold Spring Harbor Laboratory in the US.

"We found that smoking caused a significant increase in the expression of ACE2, the protein that SARS-CoV-2 uses to enter human cells," Sheltzer said.

According to the scientists, quitting smoking might reduce the risk of a severe coronavirus infection.

They said most individuals infected with the virus suffer only mild illness, if they experience any at all.

However, some require intensive care when the sometimes-fatal virus attacks, the researchers said.

In particular, they said three groups have been significantly more likely than others to develop severe illness -- men, the elderly, and smokers.

Turning to previously published data for possible explanations for these disparities, the scientists assessed if vulnerable groups share some key features related to the human proteins that the coronavirus relies on for infection.

First, they said, they focused on comparing gene activity in the lungs across different ages, between the sexes, and between smokers and nonsmokers.

The scientists said both mice that had been exposed to smoke in a laboratory, and humans who were current smokers had significant upregulation of ACE2.

According to Sheltzer, smokers produced 30-55 per cent more ACE2 than their non-smoking counterparts.

While the researchers found no evidence that age or sex impacts ACE2 levels in the lungs, they said the influence of smoke exposure was surprisingly strong.

However, they said, the change seemed to be temporary.

According to the data, the level of the receptors ACE2 in the lungs of people who had quit smoking was similar to that of non-smokers.

The study noted that the most prolific producers of ACE2 in the airways are mucus-producing cells called goblet cells.

Smoking is known to increase the prevalence of such cells, the scientists said.

"Goblet cells produce mucous to protect the respiratory tract from inhaled irritants. Thus, the increased expression of ACE2 in smokers' lungs could be a byproduct of smoking-induced secretory cell hyperplasia," Sheltzer explained.

However, Sheltzer said other studies on the effects of cigarette smoke have shown mixed results.

"Cigarette smoke contains hundreds of different chemicals. It's possible that certain ingredients like nicotine have a different effect than whole smoke does," he said.

The researchers cautioned that the actual ACE2 protein may be regulated in ways not addressed in the current study.

"One could imagine that having more cells that express ACE2 could make it easier for SARS-CoV-2 to spread in someone's lungs, but there is still a lot more we need to explore," Sheltzer said.

The World Health Organisation has warned that the COVID-19 pandemic is entering a "new and dangerous" phase. Thursday saw the most cases in a single day reported to the WHO.

Tedros Adhanom Ghebreyesus said the day had seen 150,000 new cases with half of those coming from the Americas and large numbers also from the Middle East and South Asia, the BBC reported.

He said the virus was still spreading fast and the pandemic accelerating.

He acknowledged people might be fed up with self-isolating and countries were eager to open their economies but he said that now was a time for extreme vigilance.

Maria van Kerkhove, technical lead of the WHO's COVID-19 response, told a press conference the pandemic is "accelerating in many parts of the world".

"While we have seen countries have some success in suppressing transmission and bringing transition down to a low level, every country must remain ready," she said.

Mike Ryan, the head of the WHO's Health Emergencies Programme, said that some countries had managed to flatten the peak of infections without bringing them down to a very low level.

"You can see a situation in some countries where they could get a second peak now, because the disease has not been brought under control," he said.

"The disease will then go away and reduce to a low level, and they could then get a second wave again in the autumn or later in the year."

Washington DC, Apr 17: In recent research, scientists have linked the emotional, social and psychiatric problems in children and adolescents with higher levels of genetic vulnerability for adult depression. The study implies that the genetics passed from parents may be linked with psychiatric problems in children and adolescents and may also leading to depression in adults.

University of Queensland scientists made the finding while analysing the genetic data of more than 42,000 children and adolescents from seven cohorts across Finland, the Netherlands, Norway, Sweden and the UK.

Professor Christel Middeldorp said that researchers have also found a link with a higher genetic vulnerability for insomnia, neuroticism and body mass index.

"By contrast, study participants with higher genetic scores for educational attainment and emotional well-being were found to have reduced childhood problems," Professor Middeldorp said.

"We calculated a person's level of genetic vulnerability by adding up the number of risk genes they had for a specific disorder or trait and then made adjustments based on the level of importance of each gene We found the relationship was mostly similar across ages," Middeldorp added.

The results indicate there are shared genetic factors that affect a range of psychiatric and related traits across a person's lifespan.

Middeldorp said that around 50 per cent of children and adolescents with psychiatric problems, such as attention deficit hyperactivity disorder (ADHD), continue to experience mental disorders as adults, and are at risk of disengaging with their school community among other social and emotional problems.

"Our findings are important as they suggest this continuity between childhood and adult traits is partly explained by genetic risk," the Professor said.

"Individuals at risk of being affected should be the focus of attention and targeted treatment," Middeldorp continued.

"Although the genetic vulnerability is not accurate enough at this stage to make individual predictions about how a person's symptoms will develop over time, it may become so in the future, in combination with other risk factors. And, this may support precision medicine by providing targeted treatments to children at the highest risk of persistent emotional and social problems," Middeldorp added.