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Comment by Dr. Krishna Kumari Challa on November 27, 2020 at 9:54am

Study is the first to link microbiota to dynamics of the human immune system

Researchers have uncovered an important finding about the relationship between the microbiota and the immune system, showing for the first time that the concentration of different types of immune cells in the blood changes in relation to the presence of different bacterial strains in the gut.

In recent years, the microbiota—the community of bacteria and other microorganisms that live on and in the human body—has captured the attention of scientists and the public, in part because it's become easier to study. It has been linked to many aspects of human health.

A multidisciplinary team from Memorial Sloan Kettering has shown for the first time that the gut microbiota directly shapes the makeup of the human immune system. Specifically, their research demonstrated that the concentration of different types of immune cells in the blood changed in relation to the presence of different bacterial strains in the gut. The results of their study, which used more than ten years of data collected from more than 2,000 patients, is being published November 25, 2020, in Nature.

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The data that were used in the study came from people receiving allogeneic stem cell and bone marrow transplants (BMTs). After strong chemotherapy or radiation therapy is used to destroy cancerous blood cells, the patient's blood-forming system is replaced with stem cells from a donor. For the first few weeks until the donor's blood cells—including the white blood cells that make up the immune system—have established themselves, the patients are extremely vulnerable to infections. To protect them during this time, patients are given antibiotics.

But many of these antibiotics have the unwanted side effect of destroying healthy microbiota that live in the gut, allowing dangerous strains to take over. When the patient's immune system has reconstituted, the antibiotics are discontinued, and the gut microbiota slowly starts to grow back.

The parallel recoveries of the immune system and the microbiota, both of which are damaged and then restored, gives us a unique opportunity to analyze the associations between these two systems.

Jonas Schluter et al. The gut microbiota is associated with immune cell dynamics in humans, Nature (2020). DOI: 10.1038/s41586-020-2971-8

https://medicalxpress.com/news/2020-11-link-microbiota-dynamics-hum...

Comment by Dr. Krishna Kumari Challa on November 27, 2020 at 9:43am

Scientists develop new gene therapy for eye disease

Scientists  have developed a new gene therapy approach that offers promise for one day treating an eye disease that leads to a progressive loss of vision and affects thousands of people across the globe.

The study also has implications for a much wider suite of neurological disorders associated with aging.

Characterized by degeneration of the optic nerves, DOA typically starts to cause symptoms in patients in their early adult years. These include moderate vision loss and some color vision defects, but severity varies, symptoms can worsen over time and some people may become blind. There is currently no way to prevent or cure DOA.

A gene (OPA1) provides instructions for making a protein that is found in cells and tissues throughout the body, and which is pivotal for maintaining proper function in mitochondria, which are the energy producers in cells.

Without the protein made by OPA1, mitochondrial function is sub-optimal and the mitochondrial network which in healthy cells is well interconnected is highly disrupted.

For those living with DOA, it is mutations in OPA1 and the dysfunctional mitochondria that are responsible for the onset and progression of the disorder. 

The scientists, led by Dr. Daniel Maloney and Professor Jane Farrar from Trinity's School of Genetics and Microbiology, have developed a new gene therapy, which successfully protected the visual function of mice who were treated with a chemical targeting the mitochondria and were consequently living with dysfunctional mitochondria.

The scientists also found that their gene therapy improved mitochondrial performance in human cells that contained mutations in the OPA1 gene, offering hope that it may be effective in people.

They used a clever lab technique that allows scientists to provide a specific gene to cells that need it using specially engineered non-harmful viruses. This allowed them to directly alter the functioning of the mitochondria in the cells theytreated, boosting their ability to produce energy which in turn helps protects them from cell damage.

These results  demonstrate that this OPA1-based gene therapy can potentially provide benefit for diseases like DOA, which are due to OPA1 mutations, and also possibly for a wider array of diseases involving mitochondrial dysfunction

https://www.frontiersin.org/articles/10.3389/fnins.2020.571479/full

https://www.tcd.ie/news_events/articles/scientists-develop-new-gene...

https://medicalxpress.com/news/2020-11-scientists-gene-therapy-eye-...

Comment by Dr. Krishna Kumari Challa on November 27, 2020 at 9:35am

**Study revealing the secret behind a key cellular process refutes biology textbooks

New research has identified and described a cellular process that, despite what textbooks say, has remained elusive to scientists until now—precisely how the copying of genetic material that, once started, is properly turned off.

The finding concerns a key process essential to life: the transcription phase of gene expression, which enables cells to live and do their jobs.

During transcription, an enzyme called RNA polymerase wraps itself around the double helix of DNA, using one strand to match nucleotides to make a copy of genetic material—resulting in a newly synthesized strand of RNA that breaks off when transcription is complete. That RNA enables production of proteins, which are essential to all life and perform most of the work inside cells.

Just as with any coherent message, RNA needs to start and stop in the right place to make sense. A bacterial protein called Rho was discovered more than 50 years ago because of its ability to stop, or terminate, transcription. In every textbook, Rho is used as a model terminator that, using its very strong motor force, binds to the RNA and pulls it out of RNA polymerase. But a closer look by these scientists showed that Rho wouldn't be able to find the RNAs it needs to release using the textbook mechanism.

Researchers started studying Rho, and realized it cannot possibly work in ways people tell us it works!

The research determined that instead of attaching to a specific piece of RNA near the end of transcription and helping it unwind from DNA, Rho actually "hitchhikes" on RNA polymerase for the duration of transcription. Rho cooperates with other proteins to eventually coax the enzyme through a series of structural changes that end with an inactive state enabling release of the RNA.

The team used sophisticated microscopes to reveal how Rho acts on a complete transcription complex composed of RNA polymerase and two accessory proteins that travel with it throughout transcription.

It answers a fundamental question—transcription is fundamental to life, but if it were not controlled, nothing would work. RNA polymerase by itself has to be completely neutral. It has to be able to make any RNA, including those that are damaged or could harm the cell. While traveling with RNA polymerase, Rho can tell if the synthesized RNA is worth making—and if not, Rho releases it.

"Steps toward translocation-independent RNA polymerase inactivation by terminator ATPase ρ" Science (2020). science.sciencemag.org/lookup/ … 1126/science.abd1673

https://phys.org/news/2020-11-revealing-secret-key-cellular-refutes...

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 10:35am

Covid-19 pandemic could be stopped if at least 70% public wore face...
The Covid-19 pandemic could be stopped if at least 70 per cent of the public wore face masks consistently, according to research published in the journal Physics of Fluids. The study suggests that the type of material used and the duration of mask use play key roles in their effectiveness. While surgical masks were said to be more efficient, cloth masks could also slow transmission.

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Humans are polluting the environment with antibiotic-resistant bacteria, and scientists are  finding them everywhere

https://theconversation.com/humans-are-polluting-the-environment-wi...

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** Keyhole wasps may threaten aviation safety

Over a period of 39 months, invasive keyhole wasps (Pachodynerus nasidens) at the Brisbane Airport were responsible for 93 instances of fully blocked replica pitot probes—vital instruments that measure airspeed—according to a study published November 25 in the open-access journal PLOS ONE by Alan House of Eco Logical Australia and colleagues. As noted by the authors, the results underscore the importance of risk-mitigating strategies, such as covering pitot probes when aircraft arrive and setting up additional traps to intercept the wasps.

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 10:23am

Researchers uncover the unique way stem cells protect their chromosome ends

Telomeres are specialized structures at the end of chromosomes which protect our DNA and ensure healthy division of cells. According to a new study from researchers at the Francis Crick Institute published in Nature, the mechanisms of telomere protection are surprisingly unique in stem cells.

For the last 20 years, researchers have been working to understand how telomeres protect chromosome ends from being incorrectly repaired and joined together because this has important implications for our understanding of cancer and aging.

In healthy cells, this protection is very efficient, but as we age our telomeres get progressively shorter, eventually becoming so short that they lose some of these protective functions. In healthy cells, this contributes to the progressive decline in our health and fitness as we age. Conversely, telomere shortening poses a protective barrier to tumor development, which cancer cells must solve in order to divide indefinitely.

In somatic cells, which are all the cells in the adult body except stem cells and gametes, we know that a protein called TRF2 helps to protect the telomere. It does this by binding to and stabilizing a loop structure, called a t-loop, which masks the end of the chromosome. When the TRF2 protein is removed, these loops do not form and the chromosome ends fuse together, leading to "spaghetti chromosomes" and killing the cell.

However, in this latest study, Crick researchers have found that when the TRF2 protein is removed from mouse embryonic stem cells, t-loops continue to form, chromosome ends remain protected and the cells are largely unaffected.

As embryonic stem cells differentiate into somatic cells, this unique mechanism of end protection is lost and both t-loops and chromosome end protection become reliant on TRF2. This suggests that somatic and stem cells protect their chromosome ends in fundamentally different ways.

Phil Ruis et al. TRF2-independent chromosome end protection during pluripotency, Nature (2020). DOI: 10.1038/s41586-020-2960-y

https://phys.org/news/2020-11-uncover-unique-stem-cells-chromosome....

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 10:19am

Scientists discover potential method to starve the bacteria that cause tuberculosis

The infectious disease Tuberculosis (TB) is one of the leading causes of death worldwide.

Researchers have known for some time that the bacteria that causes TB (Mycobacterium tuberculosis) uses our body's cholesterol—a steroid—as a food source. Other relatives of the bacteria that do not cause disease share its ability to break down steroids. In this study scientists identified the structure of an enzyme (acyl CoA dehydrogenase) involved in steroid degradation in another member of the same bacteria family, called Thermomonospora curvata.

Determining the structure of enzymes that metabolize steroids moves scientists and pharmaceutical companies one step closer to creating drugs that can inhibit a similar enzyme found in M. tuberculosis, which would effectively starve TB of its food source. 

Alexander J. Stirling et al. A Key Glycine in Bacterial Steroid-Degrading Acyl-CoA Dehydrogenases Allows Flavin-Ring Repositioning and Modulates Substrate Side Chain Specificity, Biochemistry (2020). DOI: 10.1021/acs.biochem.0c00568

https://phys.org/news/2020-11-scientists-potential-method-starve-ba...

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 8:22am

Waste fishing gear threatens Ganges wildlife

Waste fishing gear in the River Ganges poses a threat to wildlife including otters, turtles and dolphins, new research shows.

The study says entanglement in fishing gear could harm species including the critically endangered three-striped roofed turtle and the endangered Ganges river dolphin.

Surveys along the length of the river, from the mouth in Bangladesh to the Himalayas in India, show levels of waste fishing gear are highest near to the sea.

Fishing nets—all made of plastic—were the most common type of gear found. local fishers revealed high rates of fishing equipment being discarded in the river—driven by short gear lifespans and lack of appropriate disposal systems.

"Ingesting plastic can harm wildlife, but our threat assessment focussed on entanglement, which is known to injure and kill a wide range of marine species."

The researchers used a list of 21 river species of "conservation concern" identified by the Wildlife Institute for India.

Sarah E. Nelms et al, Riverine plastic pollution from fisheries: Insights from the Ganges River system, Science of The Total Environment (2020). DOI: 10.1016/j.scitotenv.2020.143305

https://phys.org/news/2020-11-fishing-gear-threatens-ganges-wildlif...

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 7:53am

Tunable coating allows hitch-hiking nanoparticles to slip past the immune system to their target

Nanoparticles are promising drug delivery tools, offering the ability to administer drugs directly to a specific part of the body and avoid the awful side effects so often seen with chemotherapeutics.

But there's a problem. Nanoparticles struggle to get past the immune system's first line of defense: proteins in the blood serum that tag potential invaders. Because of this, only about 1 percent of nanoparticles reach their intended target.

A team of researchers have now  developed an ionic forcefield that prevents proteins from binding to and tagging nanoparticles.

In mouse experiments, nanoparticles coated with the ionic liquid survived significantly longer in the body than uncoated particles and, surprisingly, 50 percent of the nanoparticles made it to the lungs. It's the first time that ionic liquids have been used to protect nanoparticles in the blood stream.

"The fact that this coating allows the nanoparticles to slip past serum proteins and hitch a ride on red blood cells is really quite amazing because once you are able to fight the immune system effectively, lots of opportunities open up.

"Protein-avoidant ionic liquid (PAIL)–coated nanoparticles to increase bloodstream circulation and drive biodistribution" Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abd7563

https://phys.org/news/2020-11-tunable-coating-hitch-hiking-nanopart...

Comment by Dr. Krishna Kumari Challa on November 26, 2020 at 7:09am

A pocket cooling device based on a cascade mechanism

Recent technological advances have enabled the development of increasingly compact and flexible devices. This includes wearable or portable technology.

Researchers  have recently devised a strategy that could enable the fabrication of portable, compact and flexible electrocaloric cooling devices. This strategy, outlined in a paper published in Nature Energy, is based on a four-layer cascade mechanism that enables a significant temperature lift in a user's surroundings.

This pocket cooling device designed is made of an electrocaloric polymer film. When voltage is applied to the polymer, the device heats up due to a significant entropy reduction. Conversely, when the voltage is removed, the device's temperature drops.

Yuan Meng et al. A cascade electrocaloric cooling device for large temperature lift, Nature Energy (2020). DOI: 10.1038/s41560-020-00715-3

https://techxplore.com/news/2020-11-pocket-cooling-device-based-cas...

Comment by Dr. Krishna Kumari Challa on November 25, 2020 at 9:40am

Scientists Detect 'Superbolts' 1,000 Times Brighter Than Typical Lightning Strikes

scientists have just detected a new extreme in hotspots of lightning activity called 'superbolts': intense lightning strikes that shine up to 1,000 times brighter than typical lightning strikes. 

The observations come from researchers at the US Los Alamos National Laboratory, who used satellites to measure the extreme lightning events. The results force a rethink on what constitutes a superbolt, and shed new light on how and where superbolts originate. Unlike ground-based monitoring systems, which detect radio waves, the GLM measures the total brightness (optical energy) of lightning bolts within clouds, between clouds, plus lightning that strikes the ground.

There's also the question of whether superbolts are supercharged by some unique phenomenon, or if they're just bigger, brighter strikes of the usual lightening variety.

Understanding these extreme events is important because it tells us what lightning is capable of.

The researchers combed two years of data for lightning strikes that shone 100 times brighter than a typical bolt detected from space, and found about 2 million events intense enough to be called a superbolt – roughly one in every 300 lightning events. When the researchers raised the bar to lightning events at least 1,000 times brighter than an ordinary lightning strike, they identified key hotspots of energetic superbolt activity.

Scientists found one lightning stroke that exceeded 3 terawatts of power – thousands of times stronger than ordinary lightning detected from space.

The most powerful superbolts (producing more than 350 gigawatts of power) resulted from rare positively charged cloud-to-ground events, rather than negatively charged cloud-to-ground events, which characterises most lightning strikes.

The results also showed that superbolts often occur over the ocean and tend to spark from megaflashes, which stretch hundreds of miles horizontally from tip to tail.

Oceanic storm systems, particularly during the winter, and especially those located around Japan are shown to produce these intense superbolts.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033378

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033377

https://www.sciencealert.com/study-finds-superbolts-shine-1000-time...

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