Comment

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:09am

Earlier this year, Krishnamurthy's group showed how cyanide can enable the chemical reactions that turn prebiotic molecules and water into basic organic compounds required for life. Unlike previously proposed reactions, this one worked at room temperature and in a wide pH range. The researchers wondered whether, under the same conditions, there was a way to generate amino acids, more complex molecules that compose proteins in all known living cells.

In cells today, amino acids are generated from precursors called α-keto acids using both nitrogen and specialized proteins called enzymes. Researchers have found evidence that α-keto acids likely existed early in Earth's history. However, many have hypothesized that before the advent of cellular life, amino acids must have been generated from completely different precursors, aldehydes, rather than α-keto acids, since enzymes to carry out the conversion did not yet exist. But that idea has led to debate about how and when the switch occurred from aldehydes to α-keto acids as the key ingredient for making amino acids.

After their success using cyanide to drive other chemical reactions, Krishnamurthy and his colleagues suspected that cyanide, even without enzymes, might also help turn α-keto acids into amino acids. Because they knew nitrogen would be required in some form, they added ammonia—a form of nitrogen that would have been present on the early earth. Then, through trial and error, they discovered a third key ingredient: carbon dioxide. With this mixture, they quickly started seeing amino acids form.

If you mix only the keto acid, cyanide and ammonia, it just sits there. As soon as you add carbon dioxide, even trace amounts, the reaction picks up speed.

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Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:08am

Scientists discover new 'origins of life' chemical reactions

Four billion years ago, the Earth looked very different than it does today, devoid of life and covered by a vast ocean. Over the course of millions of years, in that primordial soup, life emerged. Researchers have long theorized how molecules came together to spark this transition. Now, scientists have discovered a new set of chemical reactions that use cyanide, ammonia and carbon dioxide—all thought to be common on the early earth—to generate amino acids and nucleic acids, the building blocks of proteins and DNA.

In addition to giving researchers insight into the chemistry of the early earth, the newly discovered chemical reactions are also useful in certain manufacturing processes, such as the generation of custom labeled biomolecules from inexpensive starting materials.

Because the new reaction is relatively similar to what occurs today inside cells—except for being driven by cyanide instead of a protein—it seems more likely to be the source of early life, rather than drastically different reactions, the researchers say. The research also helps bring together two sides of a long-standing debate about the importance of carbon dioxide to early life, concluding that carbon dioxide was key, but only in combination with other molecules.

In the process of studying their chemical soup, the researchers discovered that a byproduct of the same reaction is orotate, a precursor to nucleotides that make up DNA and RNA. This suggests that the same primordial soup under the right conditions, could have given rise to a large number of the molecules that are required for the key elements of life.

 Ramanarayanan Krishnamurthy, Prebiotic synthesis of α-amino acids and orotate from α-ketoacids potentiates transition to extant metabolic pathways, Nature Chemistry (2022). DOI: 10.1038/s41557-022-00999-w. www.nature.com/articles/s41557-022-00999-w

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Comment by Dr. Krishna Kumari Challa on July 28, 2022 at 10:21am

FNDs

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...

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