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Comment by Dr. Krishna Kumari Challa on July 27, 2022 at 9:35am

Research breakthrough in mystery child hepatitis

Researchers reported a breakthrough this week in mysterious hepatitis cases affecting young children, finding the serious liver condition was linked to co-infection of two common viruses, but not the coronavirus.

The World Health Organization (WHO) has reported at least 1,010 probable cases, including 46 that required transplants and 22 deaths from the illness dating back to last October.

Previous theories had centered on a spike in commonly found adenovirus infections being behind the cases.

But in two new studies carried out independently and simultaneously in Scotland and London, scientists found another virus, AAV2 (adeno-associated virus 2) played a significant role and was present in 96 percent of all patients examined.

AAV2 is not normally known to cause disease and cannot replicate itself without another "helper" virus being present.

Both teams concluded that co-infection with either AAV2 and an adenovirus, or sometimes the herpes virus HHV6, offered the best explanation for the severe liver disease.

The presence of the AAV2 virus is associated with unexplained hepatitis in children. also cautioned it was not yet certain whether AAV2 was causing the disease or was rather a biomarker for underlying adenovirus infection that is harder to detect but was the main pathogen.

Both papers have been posted online to "preprint" servers and still await peer review before they are published in journals.

https://media.gosh.nhs.uk/documents/MEDRXIV-2022-277963v1-Breuer.pdf

https://www.medrxiv.org/content/10.1101/2022.07.19.22277425v1

https://medicalxpress.com/news/2022-07-breakthrough-mystery-child-h...

Comment by Dr. Krishna Kumari Challa on July 27, 2022 at 9:24am

Natural clean-up: Bacteria can remove plastic pollution from lakes

A study of 29 European lakes has found that some naturally-occurring lake bacteria grow faster and more efficiently on the remains of plastic bags than on natural matter like leaves and twigs.

The bacteria break down the carbon compounds in plastic to use as food for their growth.

The scientists say that enriching waters with particular species of bacteria could be a natural way to remove plastic pollution from the environment.

The effect is pronounced: the rate of bacterial growth more than doubled when plastic pollution raised the overall carbon level in lake water by just 4%.

The results suggest that the plastic pollution in lakes is 'priming' the bacteria for rapid growth— the bacteria are not only breaking down the plastic but are then more able to break down other natural carbon compounds in the lake.

Lake bacteria were found to favor plastic-derived carbon compounds over natural ones. The researchers think this is because the carbon compounds from plastics are easier for the bacteria to break down and use as food.

The scientists caution that this does not condone ongoing plastic pollution. Some of the compounds within plastics can have toxic effects on the environment, particularly at high concentrations.

Eleanor Sheridan, Plastic pollution fosters more microbial growth in lakes than natural organic matter, Nature Communications (2022). DOI: 10.1038/s41467-022-31691-9. www.nature.com/articles/s41467-022-31691-9

Comment by Dr. Krishna Kumari Challa on July 26, 2022 at 9:47am

Researchers identify how cells move faster through mucus than blood

Researchers  have discovered that certain cells move surprisingly faster in thicker fluid—think honey as opposed to water, or mucus as opposed to blood—because their ruffled edges sense the viscosity of their environment and adapt to increase their speed.

Their combined results in cancer and fibroblast cells—the type that often creates scars in tissues—suggest that the viscosity of a cell's surrounding environment is an important contributor to disease, and may help explain tumor progression, scarring in mucus-filled lungs affected by cystic fibrosis, and the wound-healing process.

The study, "Membrane ruffling is a mechanosensor of extracellular fluid viscosity," published today in Nature Physics, sheds new light on cell environments, an under-explored area of research.

The study found that the thicker the surrounding environment, the stronger the cells adhere to the substrate and the faster they move—much like walking on an icy surface with shoes that have spikes, versus shoes with no grip at all.

Jian Liu, Membrane ruffling is a mechanosensor of extracellular fluid viscosity, Nature Physics (2022). DOI: 10.1038/s41567-022-01676-y. www.nature.com/articles/s41567-022-01676-y

Comment by Dr. Krishna Kumari Challa on July 26, 2022 at 9:42am

Scientists blunt the impact of natural killer cells to improve vaccine effectiveness

Scientists have discovered that the body's own natural killer cells can suppress the immune benefits of therapeutic vaccines, a problem that can affect inoculations against chronic viral infections and cancer.

Indeed, the scientific literature is replete with examples of otherwise effective vaccines sometimes proving impotent. Increasingly, the reasons are pointing to an enemy within the body itself: a friend that transforms into a foe.

Scientists have been investigating the conundrum and have turned to an animal model to decipher how natural killer cells inadvertently blunt the benefits of vaccines.

In Science Translational Medicine, researchers report that natural killer cells can react so overwhelmingly after vaccination that they negatively impact a critical constituent of the immune response—CD8+T cells. This vital population can become overworked and exhausted, they found, a phenomenon that causes vaccination to have little effectiveness.

Therapeutic vaccines for chronic infections have reduced efficacy because of the presence of exhausted T cells and [an] environment that limits vaccine response. The problem invariably begins with the aggression of natural killer cells.

Working with a mouse model, scientists have found that a combination treatment can boost robust immune responses after vaccination by acting on natural killer cells. The strategy, the team said, may eventually prove useful in the design and improvement of therapeutic vaccines for chronic viral infections and cancers.

Mariana O. Diniz et al, NK cells limit therapeutic vaccine–induced CD8 + T cell immunity in a PD-L1–dependent manner, Science Translational Medicine (2022). DOI: 10.1126/scitranslmed.abi4670

Comment by Dr. Krishna Kumari Challa on July 24, 2022 at 1:17pm

How Climate Patterns Thousands of Miles Away Affect US Bird Migration

Comment by Dr. Krishna Kumari Challa on July 23, 2022 at 10:12am

Engineering team develops process to make implants safer

An interdisciplinary team of researchers have developed a new plasma-enabled process that could limit the proliferation of toxins from implants into a patient's bloodstream. 

In their published paper,  the authors explain that a major challenge of developing nanoparticle-modified biomedical implant material is to stably attach metallic nanoparticles on different surfaces—particularly polymer surfaces.

For years, scientists have achieved synthesis of metallic nanoparticles in aqueous solutions using both chemical and biological (plant extracts) reducing agents. The challenge of attaching metallic nanoparticles is especially difficult in cases involving hydrophobic polymeric biomaterials, which most polymeric biomaterials fall under.

To address this challenge, Thomas and his team developed a plasma-enabled process called plasma electroless reduction. The PER process allows researchers to deposit gold and silver nanostructures on different 2D and 3D polymer material surfaces, such as cellulose paper, polypropylene-based facemasks and 3D printed polymer scaffolds.

It is well known that there are toxicity issues offered by the rapid and premature release of the metallic nanostructures from the implant material into the bloodstream. This issue could be addressed only by ensuring the stable anchoring of the metallic nanostructures on implant surfaces. This has inspired us to optimize our PER process by conducting systematic and in-depth investigation of concentration of the metallic precursor followed by sonication wash before cell culture in vitro.

The team  was able to successfully anchor silver nanoparticles on the surface of 3D printed polymers without any rapid release into the surroundings. The team's additive manufacturing expertise also allowed them to design smaller 3D scaffold wafers that will fit into the well of a 96-well plate.

This systematic optimization of making uniform metal nanostructures on 3D scaffolds with cytocompatibility and potential antibacterial properties will be highly relevant and can potentially make an impact on the future development of biocompatible scaffolds, especially for osteomyelitis disease.

Vineeth M. Vijayan et al, Plasma Electroless Reduction: A Green Process for Designing Metallic Nanostructure Interfaces onto Polymeric Surfaces and 3D Scaffolds, ACS Applied Materials & Interfaces (2022). DOI: 10.1021/acsami.2c01195

Comment by Dr. Krishna Kumari Challa on July 23, 2022 at 8:20am

While the study did show a potential way that neurons could be infected, the researchers didn’t show evidence that ACE2-positive cells could infect the types of epithelial cells that compose the blood-brain barrier. They also didn’t directly show that blood-brain barrier cells could form TNTs and transfer the virus to neurons. “Are blood-brain barrier cells capable of inducing these bridges?” scientists now will have to answer this Q.

Tunneling nanotubes provide a route for SARS-CoV-2 spreading

https://www.science.org/doi/10.1126/sciadv.abo0171

https://www.the-scientist.com/news-opinion/sars-cov-2-could-use-nan...

Part 2

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Comment by Dr. Krishna Kumari Challa on July 23, 2022 at 8:18am

SARS-CoV-2 Could Use Nanotubes to Infect the Brain

Stressed cells can form hollow actin bridges to neighbors to get help, but the virus may hijack these tiny tunnels for its own purposes, a study suggests.

SARS-CoV-2 usually infects cells by binding with the angiotensin-2 converting enzyme receptor. But although many cells—including neurons and cells that make up the blood-brain barrier—lack this protein, bits of the virus have been found in the brains of infected people post-mortem. Scientists have wondered how the virus is able to enter such unwelcoming tissues. Now, a study published yesterday (July 20) in Science Advances suggests that the virus may be shuttling itself through tiny tubes that extend from infected host cells.

Tunneling nanotubes (TNTs) are delicate, hairlike structures that sprout from the cell body and pierce through neighboring cell membranes when cells are stressed, including when they’re low on oxygen or during infection. Through the tubes, which are made of the protein actin, cells can send and receive RNA, nutrients, even entire organelles—and, unfortunately, viruses. From previous work, Pasteur Institute cell biologist Chiara Zurzolo knew that some viruses use nanotubes to spread from cell to cell. 

 the researchers cultured Vero E6 cells, which model the cells that line our skin, organs, and blood vessels—and express angiotensin-2 converting enzyme (ACE2). Separately, the team also cultured SH-SY5Y, which model human neuronal cells and lack the ACE2 receptor. As predicted, the coronavirus easily infected the epithelial cells, but not the neurons. But when the scientists cultured infected epithelial cells and the neurons alongside one another, they detected viral proteins within the neurons after just one day. Furthermore, the researchers found that when ACE2 receptors were blocked, the virus was still able to find its way from infected epithelial cells to noninfected ones. 

Using a combination of fluorescence confocal microscopy and cryo-electron microscopy (cryo-EM)—a technique that involves flash-freezing samples and bombarding them with electrons, allowing researchers to capture 3D images of minuscule molecules—the scientists observed viral proteins and RNA within TNTs that were bridging cells. The TNTs also contained double-membrane vesicles, which are factories that churn out viral RNA. The researchers considered these findings strong evidence that the TNTs were acting as conduits for viral transmission, likely allowing the virus to bypass the blood-brain barrier and get into the brain.

Part 1

Comment by Dr. Krishna Kumari Challa on July 22, 2022 at 9:35am

Horizontal Gene Transfer Happens More Often Than Anyone Thought

DNA passed to and from all kinds of organisms, even across kingdoms, has helped shape the tree of life, to a large and undisputed degree in microbes and also unexpectedly in multicellular fungi, plants, and animals.

https://www.the-scientist.com/features/horizontal-gene-transfer-hap...

Comment by Dr. Krishna Kumari Challa on July 22, 2022 at 7:14am

Quantum computer works with more than zero and one

Computers work with zeros and ones, also known as binary information. This approach has been so successful that computers now power everything from ATMs to self-driving cars and planes and it is hard to imagine a life without them.

Building on this success, today's quantum computers are also designed with binary information processing in mind. The building blocks of quantum computers, however, are more than just zeros and ones. However, restricting them to binary systems prevents these devices from living up to their true potential.

A research team  now succeeded in developing a quantum computer that can perform arbitrary calculations with so-called quantum digits (qudits), thereby unlocking more computational power with fewer quantum particles. Their study is published in Nature Physics.

Although storing information in zeros and ones is not the most efficient way of doing calculations, it is the simplest way. Simple often also means reliable and robust, so binary information has become the unchallenged standard for classical computers.

In the quantum world, the situation is quite different. In the Innsbruck quantum computer, for example, information is stored in individual trapped Calcium atoms. Each of these atoms naturally has eight different states, of which typically only two are used to store information. Indeed, almost all existing quantum computers have access to more quantum states than they use for computation.

The physicists from Innsbruck have now developed a quantum computer that can make use of the full potential of these atoms, by computing with qudits. Contrary to the classical case, using more states does not make the computer less reliable. Quantum systems naturally have more than just two states and the researchers showed that they can control them all equally well.

Martin Ringbauer, A universal qudit quantum processor with trapped ions, Nature Physics (2022). DOI: 10.1038/s41567-022-01658-0. www.nature.com/articles/s41567-022-01658-0

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