Scientists edge closer to engineering blood vessels

WHO should not have dismissed Covid lab leak theory: Top virologist

Chennai: A top virologist on the UN health body's panel, Professor Marion Koopmans, has said that the World Health Organization (WHO) should never have dismissed the lab leak theory about the origin of the Covid pandemic. The WHO in its initial assessment in 2021 had stated that it was "extremely unlikely" that Covid might have spilled into humans from a lab.

In a breakthrough, a team of Australian scientists has developed a fast, inexpensive and scalable method for engineering blood vessels from natural tissue. By combining multiple materials and fabrication technologies, the team from University of Melbourne developed the method to create blood vessels with complex geometries like native blood vessels. Blood vessels serve an important function in sustaining life, by carrying oxygen-rich blood and essential nutrients to all parts of the body while removing toxic products. Illness and dysfunction in blood vessels, on the other hand, can result in life-threatening disorders such as heart attacks, strokes and aneurysms, making cardiovascular disease the number one killer globally.

According to Professor Andrea O’Connor, from the Department of Biomedical Engineering, the research is an exciting step in scientists’ ability to engineer human blood vessels. “We are now able to rapidly and cheaply manufacture blood vessels using living tissue that has appropriate mechanical properties and mimics the cellular orientation of the innermost layer of blood vessels.

“While the engineered blood vessels are not yet ready for bypass surgery, the findings mark a significant advancement in the field of tissue engineering,” O’Connor said, in the paper published in the journal ACS Applied Materials and Interfaces.

The tissue-engineered blood vessels are made from human cells and tissues. These created vessels have the potential to treat cardiovascular illness, as well as construct built-in blood supply for larger tissue creations.

Associate Professor Heath said researchers around the world have been trying to perfect blood vessel tissue engineering for many years. “Current methods are slow, require specialised and expensive equipment like bioreactors, and are low throughput -- meaning it’s difficult to provide the needed supply of engineered vessels,” Associate Professor Heath said. “By combining multiple materials and fabrication technologies, our method brings us closer to a future where engineered blood vessels will become a transformative solution for cardiovascular disease, especially for those patients who lack suitable donor vessels.”

Koopmans, who heads the Department of Viroscience at Erasmus Medical Center in Rotterdam in the Netherlands, is one of 12 people investigating the emergence of the pandemic on behalf of WHO. Speaking to the BBC podcast "Fever: The Hunt for Covid's Origin", Koopmans said the theory that the virus escaped from a secretive lab in Wuhan could never be ruled out, the Daily Mail reported. "We shouldn't have done that," she added. A team of experts from the WHO spent four weeks in China in January 2021 to investigate whether Covid-19 is the result of a lab-leak.

The agency announced that "all hypotheses remain on the table," and that "we have not yet found the source of the virus, and we must continue to follow the science and leave no stone unturned as we do." But the global health body ruled that the naturalorigins theory was the most likely -- and placed a leak from the

Wuhan Institute of Virology as "extremely unlikely" and behind the frozen-food origin theory.China, on the other hand, stated that the virus began in a US research facility in Maryland or in imported frozen food packaging. Meanwhile, Koopmans said that she hasn't ruled out both theories of the frozenfood and lab-leak. "Neither of them are ruled out in my mind," she was quoted as saying. Asked whether including the frozen-food theory in the final report undermined WHO's mission, Koopmans said: "I don't think so."

"Again, as a scientist, looking at the literature and looking at what is possible, I felt we should also not throw it out because it was pushed politically." In May, former Chinese CDC head Dr George Fu Gao, also said that the theory that Covid-19 is the result of a lableak should not be discounted. Gao directed China's CDC when Covid first emerged in Wuhan."You can always suspect anything. That's science. Don't rule out anything," Gao was quoted as saying to the same BBC podcast. China has since the beginning dismissed any suggestion the disease may have originated in a Wuhan laboratory.More than two years after the pandemic that has infected over 763 million and claimed more than 6.9 million lives globally, the origins of Covid-19 remain unclear.

Irregular sleep patterns like late sleeping on weekends, waking early on workdays could be associated with harmful bacteria in your gut and negatively affect your health, suggests a research. The study, published in The European Journal of Nutrition, is the first to find multiple associations between social jet lag -- the shift in your internal body clock when your sleeping patterns change between workdays and free days -- and diet quality, diet habits, inflammation and gut microbiome composition in a single cohort. Previous research has shown that working shifts disrupts the body clock and can increase risk of weight gain, heart problems and diabetes. However, there is less awareness that our biological rhythms can be affected by smaller incon- sistencies in sleeping patterns due to waking early with an alarm clock on workdays, for example, compared to waking naturally on non-work days for people working regular hours. Researchers found that just a 90-minute difference in the timing of the midpoint of sleep -- the halfway point between sleep time and wakeup time -- is associated with differences in gut microbiome composition.

Having social jet lag was associated with lower overall diet quality, higher intakes of sugar-sweetened beverages, and lower intakes of fruits and nuts, which may directly influence the abundance of specific microbiota in your gut. “Sleep is a key pillar of health, and this research is particularly timely given the growing interest in circadian rhythms and the gut microbiome. Even a 90-minute difference in the midpoint of sleep can encourage microbiota species which have unfavourable associations with your health,”said Kate Bermingham, from King’s College London.

“Maintaining regular sleep patterns, so when we go to bed and when we wake each day, is an easily adjustable lifestyle behaviour we can all do, that may impact your health via your gut microbiome for the better,” added Dr Sarah Berry from King’s College London. The composition of the microbes in your gut (microbiome) may negatively or positively affect your health by producing toxins or beneficial metabolites. Specific species of microbes can correspond to an individual’s risk of longterm health conditions such as diabetes, heart disease and obesity.The microbiome is influenced by the food you consume which makes the diversity of your gut adjustable.In a cohort of 934 people, researchers assessed blood, stool and gut microbiome samples as well as glucose measurements in those whose sleep was irregular compared to those who had a routine sleep schedule. While previous studies into the association between social jet lag and metabolic risk factors have been done in populations with obesity or diabetes, this cohort consisted of mainly lean and healthy individuals with most getting more than seven hours sleep per night throughout the week. Three out of the six microbiota species more abundant in the social jet lag group have ‘unfavourable’ associations with health.