Blood holds key to liver regeneration, study suggests

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.

China, where the novel coronavirus originated, has reported 111 cases since beginning of May, which shows the infection rate has dipped, and 3 deaths since April 27, according to the WHO. A Shanghai-based Noida doctor says China is close to winning the battle against COVID-19, and the combination of zinc, hydroxychloroquine (HCQ) and antibiotic azithromycin has been able to save the lives of coronavirus patients.

Speaking to media persons, Dr Sanjeev Choubey, Medical Director Internal Medicine at St. Michael Hospital said this combination has been adopted as a line of treatment for patients infected with coronavirus, and as a result patients are recovering, decreasing their need for intensive care.

What is the line of treatment for COVID-19 patients, which also include asymptomatic patients?

The combination of zinc, hydroxychloroquine and antibiotic azithromycin has produced positive results, and it helped in the recovery of many COVID-19 patients. The combination -- Ascorbic Acid, B-complex, Zinc, Selenium, L-carnitine, Vitamin B-12 and Glutathione normal saline should be administered on patients twice a week for at least 6 weeks. This is COVID-19 treatment protocol for prophylaxis, and it implies both asymptomatic and symptomatic along with other medicine support.

Based on your experience on COVID-19 in China, after how many tests, is it safe to call a person coronavirus free?

The coronavirus should be performed at least 9 times, before terming a patient COVID-19 free. It is a standard in China. This procedure has worked in China and it will also work in India. Minimum five tests should be mandatory through RT-PCR.

Does coronavirus majorly attack the respiratory system or it could lead to organ failure too?

Line of treatment should not be just looking at the respiratory system, as the problem lies somewhere else. COVID-19 attacks many vital organs in the body. In China, a coronavirus patient died from a stroke. In the autopsy it was found that the innermost layer in the arteries was swollen. It was concluded that coronavirus had inflamed the layer of the arteries leading to clotting, which was a factor in generating a heart attack. Therefore, COVID-19 is not just a respiratory problem.

Amid the coronavirus pandemic, should autopsy be made mandatory in the case of unpredictable death or where reasons for death are not unknown?

Patients below 50 years, who die suddenly and the reasons are not known, then it should be mandatory to conduct the autopsy. After death, coronavirus is active in the body for five days, and it fades away on day 6. Therefore, if an autopsy is done then it will help in understanding this disease. In China, we have seen young COVID-19 patients, aged 22 and 28, succumbed to strokes.

Since the beginning of May, India has recorded more than 2,000 cases everyday in the first week, then it jumped past 3,000 mark in the second week. Finally, the tally is 4,987 on May 17. At 90,927 cases, has India progressed into community transmission or Stage3?

Yes, India has moved into Stage 3. The data suggests that 3,000 to 4,000 active COVID-19 cases, who are asymptomatic, are moving around and spreading the infection. The research has indicated that COVID-19 from an infected person spreads in 30 minutes to non-infected persons. The relaxation on the lockdown will certainly contribute to a high infection rate.

Do you think India has reached its peak in COVID-19 cases, or the sharp rise will continue till July end?

It seems India has already reached its peak and cases will begin to come down from June end or beginning of July first week. If social distancing norms are followed then certainly things can improve, but if not followed then it may get worse. High population density is a major contributor for the increase in cases. The government should continue to focus on finding hotspots, and urge people to follow the rules, eventually it is for people’s own benefit.

Has China won the battle against COVID-19?

It seems China has won the battle by not opening up Wuhan. The Chinese are following a COVID-19 patient’s engagement program, where the authorities continuously interact with people infected with the disease. The Government of India should reward people who follow the guidelines; it will help in setting up a positive trend in the society.

Geneva, May 17: Spraying disinfectant on the streets, as practised in some countries, does not eliminate the new coronavirus and even poses a health risk, the World Health Organization (WHO) warned on Saturday.

In a document on cleaning and disinfecting surfaces as part of the response to the virus, the WHO says spraying can be ineffective. "Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is... not recommended to kill the Covid-19 virus or other pathogens because disinfectant is inactivated by dirt and debris," explains the WHO.

"Even in the absence of organic matter, chemical spraying is unlikely to adequately cover all surfaces for the duration of the required contact time needed to inactivate pathogens." The WHO said that streets and pavements are not considered as "reservoirs of infection" of Covid-19, adding that spraying disinfectants, even outside, can be "dangerous for human health".

The document also stresses that spraying individuals with disinfectants is "not recommended under any circumstances".

"This could be physically and psychologically harmful and would not reduce an infected person's ability to spread the virus through droplets or contact," said the document.

Spraying chlorine or other toxic chemicals on people can cause eye and skin irritation, bronchospasm and gastrointestinal effects, it adds.

The organisation is also warning against the systematic spraying and fumigating of disinfectants on to surfaces in indoor spaces, citing a study that has shown it to be ineffective outside direct spraying areas.

"If disinfectants are to be applied, this should be done with a cloth or wipe that has been soaked in disinfectant," it says.

The SARS-CoV-2 virus, the cause of the pandemic that has killed more than 300,000 people worldwide since its appearance in late December in China, can attach itself to surfaces and objects.

However, no precise information is currently available for the period during which the viruses remain infectious on the various surfaces.

Studies have shown that the virus can stay on several types of surfaces for several days. However, these maximum durations are only theoretical because they are recorded under laboratory conditions and should be "interpreted with caution" in the real-world environment.