Eating walnuts may help ward of several diseases: experts

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.

After admitting that the world may have a COVID-19 vaccine within one year or even a few months earlier, the World Health Organisation (WHO) on Friday said that UK-based AstraZeneca is leading the vaccine race while US-based pharmaceutical major Moderna is not far behind.

WHO Chief Scientist Soumya Swaminathan stated that the AstraZeneca's coronavirus vaccine candidate is the most advanced vaccine currently in terms of development.

"I think AstraZeneca certainly has a more global scope at the moment in terms of where they are doing and planning their vaccine trials," she told the media.

AstraZeneca's Covid-19 vaccine candidate developed by researchers from the Oxford University will likely provide protection against the disease for one year, the British drug maker's CEO told Belgian radio station Bel RTL this month.

The Oxford University last month announced the start of a Phase II/III UK trial of the vaccine, named AZD1222 (formerly known as ChAdOx1 nCoV-19), in about 10,000 adult volunteers. Other late-stage trials are due to begin in a number of countries.

Last week, Swaminathan had said that nearly 2 billion doses of the COVID-19 vaccine would be ready by the end of next year.

Addressing the media from Geneva, she said that "at the moment, we do not have a proven vaccine but if we are lucky, there will be one or two successful candidates before the end of this year" and 2 billion doses by the end of next year.

Scientists predict that the world may have a COVID-19 vaccine within one year or even a few months earlier, said the Director-General of the World Health Organization even as he underlined the importance of global cooperation to develop, manufacture and distribute the vaccines.

However, making the vaccine available and distributing it to all will be a challenge and will require political will, WHO chief Tedros Adhanom Ghebreyesus said on Thursday during a meeting with the European Parliament's Committee for Environment, Public Health and Food Safety.

One option would be to give the vaccine only to those who are most vulnerable to the virus.

There are currently over 100 COVID-19 vaccine candidates in various stages of development.

Bergen, Mar 5: Divorce of parents may impact the academics of children negatively, suggests a new study.

According to the study, parental divorce is associated with a lower grade point average (GPA) among adolescents, with a stronger association seen in teens with more educated mothers.

The study was published in the journal PLOS ONE.

Children and adolescents with divorced or separated parents are known to do less well in school than adolescents with nondivorced parents and to be less well-adjusted, on average, across a spectrum of physical and mental health outcomes.

In the new study, researchers used data from the youth@hordaland study, a population-based survey of adolescents aged 16-19 conducted in the spring of 2012 in Hordaland County, Norway.

19,439 adolescents were invited to participate and 10,257 agreed; of those, 9,166 are included in the current study.

Overall, adolescents with divorced parents had a 0.3 point lower GPA (standard error 0.022, p<0.01) than their peers.

Controlling for parental education reduced the effect by 0.06 points to 0.240 (SE 0.021, p<0.01). This heterogeneity was predominantly driven by maternal education levels, the researchers found.

After controlling for paternal education and income measures, divorce was associated with a 0.120 point decrease in GPA among adolescents whose mothers had a secondary school education level; a 0.175 point decrease when mothers had a Bachelor's level education; and a 0.209 point decrease when mothers had a Master's or PhD level education (all estimates relative to adolescents with a mother who had a basic level of education, such as ISCED 0-2).

Due to the cross-sectional structure of the study, researchers could not investigate specific changes between pre- and post-divorce family life, and future studies are needed to investigate potential mechanisms (such as reduced parental monitoring or school-involvement) which might drive this finding.

Nonetheless, this study provides new evidence that the negative association between divorce and teens' GPA is especially strong in families with more educated mothers.

"Among Norwegian adolescents, parental divorce was hardly associated with GPA among youth whose parents have low educational qualifications. In contrast, among adolescents with educated or highly educated mothers, divorce was significantly associated with lower GPA," said the authors.