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Washington, Feb 21: The fat around arteries may play an important role in keeping the blood vessels healthy, according to a study in rats that may affect how researchers test for treatments related to plaque buildup, as seen in conditions leading to heart attack.

The study, published in the journal Scientific Reports, noted that the fat, known as perivascular adipose tissue, or PVAT, helps arteries let go of muscular tension while under constant strain.

According to the researchers, including Stephanie W. Watts from the Michigan State University in the US, this feature is similar to how the bladder expands to accommodate more liquid, while at the same time keeping it from spilling out.

"In our study, PVAT reduced the tension that blood vessels experience when stretched," Watts said.

"And that's a good thing, because the vessel then expends less energy. It's not under as much stress," she added.

According to Watts and her team, PVAT has largely been ignored by researchers believing its main job was to store lipids and do little more.

Until now, she said, scientists only divided blood vessels into three parts, the innermost layer called the tunica intima, the middle layer called the tunica media, and the outermost layer called the tunica adventitia.

Watts believes PVAT is the fourth layer, which others have called tunica adiposa.

Tunica, she said, meant a membranous sheath enveloping or lining an organ, and adiposa is a synonym for fat.

"For years, we ignored this layer -- in the lab it was thrown out. In the clinic it wasn't imaged. But now we're discovering it may be integral to our blood vessels," Watts said.

"Our finding redefines what the functional blood vessels are, and is part of what can be dysfunctional in diseases that afflict us, including hypertension. We need to pay attention to this layer of a blood vessel because it does far more than we originally thought," she added.

Earlier studies, Watts said, had shown that PVAT plays a role in the functioning of blood vessels, finding that it secretes substances that can cause blood vessels to relax as well as substances that can cause it to contract.

In the current study, the researchers decided to test whether PVAT provides a structural benefit to arteries by assisting the function of stress relaxation.

They tested the thoracic aorta in rats, and found those with intact PVAT had more stress relaxation than those without.

The study revealed that the pieces of artery with surrounding fat had measurably relaxed more than those without.

Watts and her colleagues then tested other arteries, and were able to duplicate the same response.

"It's not something you see only in this particular vessel or this particular species or this particular strain. But that maybe it's a general phenomenon," she 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.

Lower neighbourhood socioeconomic status and greater household crowding increase the risk of becoming infected with SARS-CoV-2, the virus that causes COVID-19, warn researchers.

"Our study shows that neighbourhood socioeconomic status and household crowding are strongly associated with risk of infection," said study lead author Alexander Melamed from Columbia University in the US.

"This may explain why Black and Hispanic people living in these neighbourhoods are disproportionately at risk for contracting the virus," Melamed added.

For the findings, published in the journal JAMA, the researchers examined the relationships between COVID-19 infection and neighbourhood characteristics in 396 women who gave birth during the peak of the Covid-19 outbreak in New York City. Since March 22, all women admitted to the hospitals for delivery have been tested for the virus, which gave the researchers the opportunity to detect all infections -- including infections with no symptoms -- in a defined population

The strongest predictor of COVID-19 infection among these women was residence in a neighbourhood where households with many people are common.The findings showed that women who lived in a neighbourhood with high household membership were three times more likely to be infected with the virus. Neighbourhood poverty also appeared to be a factor, the researchers said.Women were twice as likely to get COVID-19 if they lived in neighbourhoods with a high poverty rate, although that relationship was not statistically significant due to the small sample size.

The study revealed that there was no association between infection and population density.

"New York City has the highest population density of any city in the US, but our study found that the risks are related more to density in people's domestic environments rather than density in the city or within neighbourhoods," says co-author Cynthia Gyamfi-Bannerman."

The knowledge that SARS-CoV-2 infection rates are higher in disadvantaged neighbourhoods and among people who live in crowded households could help public health officials target preventive measures," the authors wrote.

Recently, another study published in the Journal of the American Planning Association, showed that dense areas were associated with lower COVID-19 death rates.