Losing weight may cut breast cancer risk: study

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.

Jan 31: Cervical cancer could be eliminated worldwide as a public health issue within the next 100 years, according to two studies which may lead to better strategies for screening and vaccination against the malignant disease.

According to the studies, published in the journal The Lancet, more than 74 million cervical cancer cases, and 60 million deaths could be averted, and the disease eliminated in the 78 countries which have the highest disease burden.

The researchers, including those from Laval University in Canada, said cervical cancer is the second most frequent cancer among women in low-income and lower-middle-income countries (LMICs) with 2,90,000 (51 per cent) of the 5,70,000 new cases worldwide reported in women living in LMICs.

In the current studies, the scientists used the WHO draft strategy of cervical cancer elimination which defines plans for vaccination against the disease's causative agent, the human papillomavirus (HPV).

These plans, they explained, call for 90 per cent of girls to be vaccinated against HPV by 2030, and for 70 per cent of women to be screened for cervical cancer once or twice in their lifetime.

About 90 per cent of women with precancerous lesions, or cervical cancer are also advised to receive appropriate treatment, according to the WHO draft strategy, the scientists said.

In the second study, the research team analysed the impact of three elements of the WHO strategy on deaths from cervical cancer -- modelling the impact of scaling up cancer treatment, as well as vaccination and screening

"Our findings emphasise the importance of acting immediately to combat cervical cancer on all three fronts," said Karen Canfell from the University of Sydney in Australia, who co-led both the studies.

"In just 10 years, it's possible to reduce deaths from the disease by a third and, over the next century, more than 60 million women's lives could be saved. This would represent an enormous gain in terms of both quality of life, and lives saved," Canfell said.

By adding the two screening tests, and with the treatment of precancerous cervical lesions, cases of the cancer may drop by 97 per cent, and 72 million cervical cancer cases could be averted over the next century, the researchers said.

Scaling-up of appropriate cancer treatment could avert 62 million cervical cancer deaths, the study noted.

"For the first time, we've estimated how many cases of cervical cancer could be averted if WHO's strategy is rolled out and when elimination might occur," said Marc Brisson, study co-author from Laval University.

"Our results suggest that to eliminate cervical cancer it will be necessary to achieve both high vaccination coverage, and a high uptake of screening and treatment, especially in countries with the highest burden of the disease," Brisson added.

Based on the results of the studies, WHO's cervical cancer elimination strategy has been updated which will be presented for adoption at the World Health Assembly in May 2020, the scientists noted.

"If the strategy is adopted and applied by member states, cervical cancer could be eliminated in high income countries by 2040, and across the globe within the next century, which would be a phenomenal victory for women's health," Brisson said.

"However, this can only be achieved with considerable international financial and political commitment, in order to scale-up prevention and treatment," he added.

Singapore, May 25: COVID-19 patients are no longer infectious after 11 days of getting sick even though some may still test positive, according to a new study by infectious disease experts in Singapore.

A positive test "does not equate to infectiousness or viable virus," a joint research paper by Singapore's National Centre for Infectious Diseases and the Academy of Medicine, Singapore said. The virus "could not be isolated or cultured after day 11 of illness."

The paper was based on a study of 73 patents in the city-state.

The latest findings may have implications on the country's patient discharge policy. The discharge criteria is currently based on negative test results rather than infectiousness.

Singapore's strategy on managing COVID-19 patients is guided by the latest local and international clinical scientific evidence, and the Ministry of Health will evaluate if the latest evidence can be incorporated into its patient clinical management plan, according to a report by the Straits Times.

So far, 13,882, or about 45% of the total 31,068 Covid-19 patients in Singapore have been discharged from hospitals and community facilities. Singapore reported 642 new Covid-19 cases as of noon on Saturday.

The government has been actively screening pre-school staff as it prepares to reopen pre-schools from June 2. On Friday, two pre-school employees tested positive for the novel coronavirus, bringing the total number of confirmed cases among pre-school staff to seven, according to the Ministry of Health.