Tag Archives: SARS-CoV-2
Diabetics die 3 times more of Covid-19
From the outset of the pandemic, data coming out of early coronavirus hot spots like China, Italy, and New York City foretold that certain groups of people would be more vulnerable to Covid-19. The disease hit older people and people with underlying medical conditions the hardest. As early as February, diabetes had emerged as one of the conditions associated with the highest risk. In one large study out of China, people with diabetes were more than three times as likely to die of Covid-19 than the overall population.
But that’s not what brought four diabetes experts from Australia and the United Kingdom onto a Zoom call back in April. They were supposed to just be catching up—a virtual tea among friends. But talk soon turned to something strange that they’d been seeing in their own hospitals and hearing about through the grapevine. The weird thing was that people were showing up in Covid-19 wards, after having tested positive for the virus, with lots of sugar in their blood. These were people with no known history of diabetes. But you wouldn’t know it from their lab results.
After that call, the experts reached out to colleagues in other countries to see if they’d seen or heard of similar cases. They had. Acute viral infections of all sorts can stress the body, causing blood sugar levels to rise. So that in itself wasn’t unusual, says Francesco Rubino, a bariatric surgeon and diabetes researcher at King’s College in London, who was on that first Zoom call. “What we were seeing and hearing was a little bit different.”
Doctors around the world had described to him strange situations in which Covid-19 patients were showing symptoms of diabetes that didn’t fit the typical two-flavor manifestation of the disease. In most people with type 1 diabetes, their immune cells suddenly turn traitorous, destroying the cells in the pancreas that produce insulin—the hormone that allows glucose to exit the bloodstream and enter cells. People with type 2 diabetes have a different problem; their body slowly becomes resistant to the insulin it does produce. Rubino and his colleagues were seeing blended features of both types showing up spontaneously in people who’d recently been diagnosed with Covid-19.
“That was the first clinical puzzle,” he says. For clues to an explanation, Rubino and his colleagues looked to ACE2, the protein receptor that SARS-CoV-2 uses to invade human cells. It appears in the airways, yes, but also in other organs involved in controlling blood sugar, including the gut. Doctors in China discovered copies of the coronavirus in the poop of their Covid-19 patients. And a meta-analysis found that gastrointestinal symptoms plague one out of 10 Covid-19 sufferers.
In the last few decades, scientists have discovered that the gut is not the passive digestive organ once thought. It actually is a major endocrine player—responsible for producing hormone signals that talk to the pancreas, telling it to make more insulin, and to the brain, ordering it to make its owner stop eating. If the coronavirus is messing with these signals, that could provide a biological basis for why Covid-19 would be associated with different forms of diabetes, including hybrid and previously unknown manifestations of the disease. Rubino is one of a growing number of researchers who think that the relationship between the coronavirus and diabetes is actually a two-way street. Having diabetes doesn’t just tip the odds toward contracting a worse case of Covid-19. In some people, the virus might actually trigger the onset of diabetes, and the potential for a lifetime of having to manage it.
Source: https://www.wired.com/
‘Game Changing’ 15-Minute Covid-19 Test Cleared in Europe
Becton Dickinson and Co.’s Covid-19 test that returns results in 15 minutes has been cleared for use in countries that accept Europe’s CE marking, the diagnostics maker said Wednesday. The test is part of a new class of quicker screening tools named for the identifying proteins called antigens they detect on the surface of SARS-CoV-2. Becton Dickinson expects to begin selling the test, which runs on the company’s cellphone-sized BD Veritor Plus System, in European markets at the end of October. It will likely be used by emergency departments, general practitioners and pediatricians.
Becton Dickinson said its antigen assay is 93.5% sensitive, a measure of how often it correctly identifies infections, and 99.3% specific, the rate of correct negative tests. The data, which differ from the U.S. label’s 84% sensitivity and 100% specificity, come from a new clinical study that was recently submitted to the U.S. , spokesman Troy Kirkpatrick said.
Coronavirus Vaccine: When Will We Have One?
There are around 40 different coronavirus vaccines in clinical trials – including one being developed by the University of Oxford that is already in an advanced stage of testing. The virus spreads easily, and the majority of the world’s population is still vulnerable to it. A vaccine would provide some protection by training people’s immune systems to fight the virus so they should not become sick. This would allow lockdowns to be lifted more safely, and social distancing to be relaxed.
Research is happening at breakneck speed. About 240 vaccines are in early development, with 40 in clinical trials and nine already in the final stage of testing on thousands of people. Trials of the Oxford vaccine show it can trigger an immune response, and a deal has been signed with AstraZeneca to supply 100 million doses in the UK alone. The first human trial data back in May indicated the first eight patients taking part in a US study all produced antibodies that could neutralise the virus. A group in China showed a vaccine was safe and led to protective antibodies being made. It is being made available to the Chinese military.
Other completely new approaches to vaccine development are in human trials. However, no-one knows how effective any of these vaccines will be. A vaccine would normally take years, if not decades, to develop. Researchers hope to achieve the same amount of work in only a few months. Most experts think a vaccine is likely to become widely available by mid-2021, about 12-18 months after the new virus, known officially as Sars-CoV-2, first emerged. That would be a huge scientific feat, and there are no guarantees it will work. But scientists are optimistic that, if trials are successful, then a small number of people – such as healthcare workers – may be vaccinated before the end of this year. It is worth noting that four coronaviruses already circulate in human beings. They cause common cold symptoms and we don’t have vaccines for any of them.
3D Mapping of Coronavirus Genome
The novel coronavirus uses structures within its RNA to infect cells. Scientists have now identified these configurations, generating the most comprehensive atlas to date of SARS-CoV-2’s genome. Although contained in a long, noodle-like molecule, the new coronavirus’s genome looks nothing like wet spaghetti. Instead, it folds into stems, coils, and cloverleafs that evoke molecular origami.
A team led by RNA scientist Anna Marie Pyle has now made the most comprehensive map to date of these genomic structures. In two preprints posted in July 2020 to bioRxiv.org, Pyle’s team mapped structures across the entire RNA genome of the coronavirus SARS-CoV-2, using living cells and computational analyses.
SARS-CoV-2 relies on its unique RNA structures to infect people and cause the illness COVID-19. But these structures’ contribution to infection and disease is often underappreciated, even among scientists, says Pyle, a Howard Hughes Medical Institute Investigator at Yale University.
Colorized scanning electron micrograph of a cell (blue) heavily infected with SARS-CoV-2 virus particles (red), isolated from a patient sample. Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland
“The general wisdom is that if we just focus on the proteins encoded in the virus’s genome, we’ll understand how SARS-CoV-2 works,” Pyle says. “But for these types of viruses, RNA structures in the genome can influence their ability to function as much as encoded proteins.”
Researchers can now begin to tease out just how these structures aid the virus—information that could ultimately lead to new treatments for COVID-19. Once scientists have identified RNA structures that carry out key tasks, for instance, it may be possible to devise ways to disrupt them—and interfere with infection.
Source: https://www.hhmi.org/
AND
https://phys.org/
Quick And Affordable Saliva-based COVID-19 Test
A saliva-based laboratory diagnostic test developed by researchers at the Yale School of Public Health to determine whether someone is infected with the novel coronavirus has been granted an emergency use authorization by the U.S. Food and Drug Administration (FDA).
The method, called SalivaDirect, is being further validated as a test for asymptomatic individuals through a program that tests players and staff from the National Basketball Association (NBA). SalivaDirect is simpler, less expensive, and less invasive than the traditional method for such testing, known as nasopharyngeal (NP) swabbing. Results so far have found that SalivaDirect is highly sensitive and yields similar outcomes as NP swabbing.
With the FDA’s emergency use authorization, the testing method is immediately available to other diagnostic laboratories that want to start using the new test, which can be scaled up quickly for use across the nation — and, perhaps, beyond — in the coming weeks, the researchers said. A key component of SalivaDirect, they note, is that the method has been validated with reagents and instruments from multiple vendors. This flexibility enables continued testing if some vendors encounter supply chain issues, as experienced early in the pandemic.
“This is a huge step forward to make testing more accessible,” said Chantal Vogels, a Yale postdoctoral fellow, who led the laboratory development and validation along with Doug Brackney, an adjunct assistant clinical professor. “This started off as an idea in our lab soon after we found saliva to be a promising sample type of the detection of SARS-CoV-2, and now it has the potential to be used on a large scale to help protect public health. We are delighted to make this contribution to the fight against coronavirus.”
Development of SalivaDirect as a means of rapidly expanding SARS-CoV-2 testing was spearheaded this spring by Nathan Grubaugh and Anne Wyllie, assistant professor and associate research scientist, respectively, at Yale School of Public Health. After finding saliva to be a promising sample type for SARS-CoV-2 detection, they wanted to improve the method further.
The preprint on the development and validation of SalivaDirect was recently posted on medRxiv.
Source: https://news.yale.edu/
Coronavirus And Cancer Hijack The Same Parts In Human Cells To Spread
Most antivirals in use today target parts of an invading virus itself. Unfortunately, SARS-CoV-2 – the virus that causes COVID-19 – has proven hard to kill. But viruses rely on cellular mechanisms in human cells to help them spread, so it should be possible to change an aspect of a person’s body to prevent that and slow down the virus enough to allow the immune system to fight the invader off.
A quantitative biologist built a map of how the coronavirus uses human cells. He used that map to find already existing drugs that could be repurposed to fight COVID-19 and has been working with an international group of researchers called the QBI Coronavirus Research Group to see if the identified drugs showed any promise. Many have.
For years, researchers have suspected that kinases – biological control switches that viruses use to take over cells – could be targeted to fight infections. Over the last few months, we built a second, more detailed map looking specifically for the kinases that the coronavirus is hijacking.
A few already existing cancer drugs have been identified which alter the function of the kinases that SARS-CoV-2 hijacks, and began testing them in coronavirus-infected cells. The results of these early tests are promising and human clinical trials have begun.
Coronavirus Uses Same Strategy As HIV To Dodge Immune Response
The novel coronavirus uses the same strategy to evade attack from the human immune system as HIV, according to a new study by Chinese scientists.
Both viruses remove marker molecules on the surface of an infected cell that are used by the immune system to identify invaders, the researchers said in a non-peer reviewed paper posted on preprint website bioRxiv.org on Sunday. They warned that this commonality could mean Sars-CoV-2, the clinical name for the virus, could be around for some time, like HIV.
Virologist Zhang Hui and a team from Sun Yat-sen University in Guangzhou also said their discovery added weight to clinical observations that the coronavirus was showing “some characteristics of viruses causing chronic infection”.
Their research involved collecting killer T cells from five patients who had recently recovered from Covid-19, the disease caused by the virus. Those immune cells are generated by people after they are infected with Sars-CoV-2 – their job is to find and destroy the virus.
The molecule is an identification tag usually present in the membrane of a healthy cell, or in sick cells infected by other coronaviruses such as severe acute respiratory syndrome, or Sars. It changes with infections, alerting the immune system whether a cell is healthy or infected by a virus. HIV uses the same strategy – MHC molecules are also absent in cells infected with that virus. “In contrast, Sars does not make use of this function,” Zhang said.
The coronavirus removes these markers by producing a protein known as ORF8, which binds with MHC molecules, then pulls them inside the infected cell and destroys them, the researchers said. ORF8 is known to play an important role in viral replication, and most commercial test kits target this gene to detect viral loads in nose or oral swabs.
While drugs being used to treat Covid-19 patients mainly targeted enzymes or structural proteins needed for viral replication, Zhang and his team suggested compounds be developed “specifically targeting the impairment of MHC by ORF8, and therefore enhancing immune surveillance for Sars-CoV-2 infection”.
Source: https://www.scmp.com/
New COVID-19 Vaccine Shows Promise
An experimental COVID-19 vaccine protected monkeys from catching the viral infection, according to an unreviewed report. The new vaccine has now entered clinical trials in China to test the drug in humans.
Although the animal study, posted April 19 to the preprint database bioRxiv, has not been subject to formal review, scientists took to Twitter to share their first impressions.
“So, this is the first ‘serious’ preclinical data I have seen for an actual vaccine candidate,” Florian Krammer, a professor in the Department of Microbiology at the Icahn School of Medicine at Mount Sinai, tweeted on April 22. Before being tested in healthy humans, vaccines undergo so-called preclinical tests in animals. The experimental vaccine, developed by the Beijing-based company Sinovac Biotech, showed promising results in rhesus macaques before entering human trials, Krammer noted. “I’m a fan,” he added in another tweet.
Now in clinical trials, various doses of the vaccine will be given to 144 individuals to determine whether it’s safe, meaning it does not cause dangerous side effects, according to ClinicalTrials.gov. The vaccine would then move into efficacy trials with more than 1,000 additional people to determine whether it triggers an adequate immune response, commented Meng Weining, Sinovac’s senior director for overseas regulatory affairs.
The Sinovac vaccine contains an inactivated version of SARS-CoV-2, the virus that causes COVID-19. By introducing an inactive virus into the body, the vaccine should prompt the immune system to build antibodies that target the pathogen without triggering an actual COVID-19 infection. When given to mice, rats and rhesus macaques, the vaccine sparked the production of such antibodies, according to the bioRxiv report. “This is old-fashioned technology,” which would make the product easy to manufacture, Krammer wrote on Twitter. “What I like most is that many vaccine producers, also in lower–middle-income countries, could make such a vaccine,” he added in an interview
Source: http://www.sinovac.com/
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https://www.livescience.com/
New Biosensor Measures The Concentration Of Covid-19 In The Air
A team of researchers from Empa, ETH Zurich and Zurich University Hospital has succeeded in developing a novel sensor for detecting the new coronavirus. In future it could be used to measure the concentration of the virus in the environment – for example in places where there are many people or in hospital ventilation systems.
Jing Wang and his team at Empa and ETH Zurich usually work on measuring, analyzing and reducing airborne pollutants such as aerosols and artificially produced nanoparticles. However, the challenge the whole world is currently facing is also changing the goals and strategies in the research laboratories. The new focus: a sensor that can quickly and reliably detect SARS-CoV-2 – the new coronavirus.
But the idea is not quite so far removed from the group’s previous research work: even before the COVID-19 began to spread, first in China and then around the world, Wang and his colleagues were researching sensors that could detect bacteria and viruses in the air. The sensor will not necessarily replace the established laboratory tests, but could be used as an alternative method for clinical diagnosis, and more prominently to measure the virus concentration in the air in real time: For example, in busy places like train stations or hospitals.
Fast and reliable tests for the new coronavirus are urgently needed to bring the pandemic under control as soon as possible. Most laboratories use a molecular method called reverse transcription polymerase chain reaction, or RT-PCR for short, to detect viruses in respiratory infections. This is well established and can detect even tiny amount of viruses – but at the same time it can be time consuming and prone to error.
Jing Wang and his team have developed an alternative test method in the form of an optical biosensor. The sensor combines two different effects to detect the virus safely and reliably: an optical and a thermal one.
The sensor uses an optical and a thermal effect to detect the COVID-19-Virus safely and reliably
The sensor is based on tiny structures of gold, so-called gold nanoislands, on a glass substrate. Artificially produced DNA receptors that match specific RNA sequences of the SARS-CoV-2 are grafted onto the nanoislands. The coronavirus is a so-called RNA virus: Its genome does not consist of a DNA double strand as in living organisms, but of a single RNA strand. The receptors on the sensor are therefore the complementary sequences to the virus’ unique RNA sequences, which can reliably identify the virus.
The technology the researchers use for detection is called LSPR, short for localized surface plasmon resonance. This is an optical phenomenon that occurs in metallic nanostructures: When excited, they modulate the incident light in a specific wavelength range and create a plasmonic near-field around the nanostructure. When molecules bind to the surface, the local refractive index within the excited plasmonic near-field changes. An optical sensor located on the back of the sensor can be used to measure this change and thus determine whether the sample contains the RNA strands in question.
Source: https://www.empa.ch/
Coronavirus: A map of Sars-CoV-2 activated proteins
What happens when the pathogen responsible for the Covid-19 pandemic, the coronavirus Sars-CoV-2, makes contact with a human bronchial cell? A group of researchers from the University of Bologna and University of Catanzaro (Italy) mapped the interactions between the virus proteins and those of humans, showing which proteins are being “activated” and “de-activated” by Sars-CoV-2.
SARS-COV2/human interactome
“Gaining knowledge about the molecular effects of Sars-CoV-2 on human proteins is fundamental to devise effective drug therapies,” says Federico M. Giorgi, principal investigator of the study and a researcher at the University of Bologna. “Inhibiting the interactions that we mapped may represent an effective strategy for a therapy able to contain the disruptive force of Sars-CoV-2 and other coronaviruses on human cells.”
This study was published on the Journal of Clinical Medicine. The researchers were able to identify human cell defense mechanisms, when the virus enters the body, for example, as well as how Sars-CoV-2 spreads in the human body, e.g., via proteins favoring its replication.
Beta-coronaviruses, a sub-family of coronaviruses, mainly cause respiratory and intestinal diseases. To date, we are aware of seven strains of beta-coronavirus that affect humans. Three of them are particularly dangerous: Sars-CoV, causing Sars, Mers-CoV, causing Mers, and the new Sars-CoV-2, causing Covid-19, the illness that has already infected over 1 million people around the globe.
We know that Sars-CoV-2 has a lot in common with its beta-coronavirus “cousins,” and with Sars-CoV in particular. Nevertheless, a detailed description of how this virus attacks human cells is still missing. To shed some light on this issue, researchers compared the interactome (the set of interactions between proteins) deriving from the encounter between Sars-CoV-2 and a human cell with the available information on the behavior of Sars-CoV and Mers-CoV viruses.
Source: https://phys.org/
