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Comment by Dr. Krishna Kumari Challa on September 13, 2022 at 10:29am

Study finds antibiotics may make melanoma worse, by depleting the gut microbiome

The use of broad-spectrum antibiotics in mice with malignant melanoma, an aggressive form of skin cancer, accelerated their metastatic bone growth, likely because the drugs depleted the mice's intestinal flora and weakened their immune response, according to a new study by researchers.

The findings underscore the importance of the gut microbiome in overall health and suggest that doctors should carefully weigh the gastrointestinal effects when they use antibiotic therapies while treating cancer or other diseases.

Any disease or therapy that harms the gut microbiome could have a negative impact on our health.

This new study  found that the gut microbiome restrains the progression of melanoma bone lesions in mice by promoting the expansion of intestinal natural-killer (NK) cells and T helper (Th1) cells and enhancing their migration to the tumour site. Using oral antibiotics depleted the gut microbiome and reduced the population of intestinal NK cells and Th1 cells. This made the mice more vulnerable for tumour growth. They had a higher melanoma tumor burden than control mice whose gut microbiomes were intact.

https://www.jci.org/articles/view/157340

Comment by Dr. Krishna Kumari Challa on September 13, 2022 at 10:16am

Scientists discover how air pollution triggers lung cancer

Scientists  have identified the mechanism through which air pollution triggers lung cancer in non-smokers, a discovery one expert hailed as "an important step for science—and for society".

The research illustrated the health risk posed by the tiny particles produced by burning fossil fuels, sparking fresh calls for more urgent action to combat climate change. It could also pave the way for a new field of cancer prevention.

Scientists presented the research, which has not yet been published in a peer-reviewed journal, at the European Society for Medical Oncology's annual conference in Paris.

Air pollution has long been thought to be linked to a higher risk of lung cancer in people who have never smoked.

Researchers found that exposure to tiny PM2.5 pollution particles—which are less than 2.5 microns across—led to an increased risk of mutations in the EGFR gene. In laboratory studies on mice, they  showed that the particles caused changes in the EGFR gene as well as in the KRAS gene, both of which have been linked to lung cancer.

Finally, they analyzed nearly 250 samples of human lung tissue never exposed to carcinogens from smoking or heavy pollution.

Even though the lungs were healthy, they found DNA mutations in 18 percent of EGFR genes and 33 percent of KRAS genes.

They're just sitting there and the mutations seem to increase with age. On their own, they probably are insufficient to drive cancer.

But when a cell is exposed to pollution it can trigger a "wound-healing response" that causes inflammation. And if that cell harbours a mutation, it will then form a cancer.

In another experiment on mice, the researchers showed that an antibody could block the mediator—called interleukin 1 beta—which sparks the inflammation, stopping cancer from getting started in the first place.

LBA1 'Mechanism of action and an actionable inflammatory axis for air pollution induced non-small cell lung cancer in never smokers' will be presented by Charles Swanton during Presidential Symposium 1 on Saturday, 10 September, 16:30 to 18:00 CEST in Paris Auditorium. Annals of Oncology, Volume 33 Supplement 7, September 2022. www.esmo.org/meetings/esmo-congress-2022

Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:52am

A plastic film that can kill viruses using room lights

Researchers  have developed a plastic film that can kill viruses that land on its surface with room light. The self-sterilizing film is the first of its kind—it is low cost to produce, can be readily scaled and could be used for disposable aprons, tablecloths, and curtains in hospitals. It is coated with a thin layer of particles that absorb UV light and produce reactive oxygen species—ROS. These kill viruses, including SARS-CoV-2.

The technology used to create the film also ensures it is degradable—unlike the current disposable plastic films it would replace, which is much more environmentally friendly. The breakthrough could lead to a significant reduction in the transmission of viruses in healthcare environments but also in other settings that uses plastic films—for example, food production factories.

Researchers tested the film for anti-viral activity using four different viruses—two strains of influenza A virus, a highly-stable picornavirus called EMCV and SARS-CoV-2—exposing it to either UVA radiation or with light from a cool white light fluorescent lamp.

They found that the film is effective at killing all of the viruses—even in a room lit with just white fluorescent tubes.

Ri Han et al, Flexible, disposable photocatalytic plastic films for the destruction of viruses, Journal of Photochemistry and Photobiology B: Biology (2022). DOI: 10.1016/j.jphotobiol.2022.112551

Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:49am

Gut microbes may lead to therapies for mental illness, study reports

The role of the microbiome in intestinal and systemic health has garnered close attention among researchers for many years. Now evidence is mounting that this collection of microorganisms in the human gut can also impact a person's neurological and emotional health, according to a recent perspective article in Science by a UT Southwestern researcher.

Scientists are unraveling the relationship of the microbiome to the brain, including connections to diseases such as depression and amyotrophic lateral sclerosis (ALS). 

Jane A. Foster, Modulating brain function with microbiota, Science (2022). DOI: 10.1126/science.abo4220

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Comment by Dr. Krishna Kumari Challa on September 10, 2022 at 8:46am

Antibiotics given in infancy may have adverse impact on adult gut health

Preterm and low birth-weight babies are routinely given antibiotics to prevent⁠—not just treat⁠—infections, which they have a high risk of developing. A new study published in The Journal of Physiology has found that early life exposure to antibiotics in neonatal mice has long-lasting effects on their microbiota, enteric nervous system, and gut function. This could mean that babies given antibiotics may grow up to experience gastrointestinal issues.

This discovery by a research team  is the first to show that antibiotics given to neonatal mice yields these long-lasting effects that result in disturbed gastrointestinal function, including the speed of motility through the gut and diarrhea-like symptoms in adulthood.

The research team gave mice an oral dose of vancomycin every day for the first ten days of their lives. They were then reared normally until they were young adults, and their gut tissue was looked at to measure its structure, function, microbiota, and nervous system. The investigators found that changes were also dependent on the sex of the mice. The females had long whole gut transit and the males had lower fecal weight than the control group. Both males and females had greater fecal water content, which is a diarrhea-like symptom.

Neonatal antibiotics have long-term sex-dependent effects on the enteric nervous system, The Journal of Physiology (2022). DOI: 10.1113/JP282939

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Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 10:20am

The first known surgical amputation

Prehistoric child’s amputation is oldest surgery of its kind

Skeleton missing lower left leg and dated to 31,000 years ago provides the earliest known evidence for surgical limb removal.

The skeleton of a person who lived 31,000 years ago bears hallmarks of the deliberate removal of their lower left leg — the earliest known surgery of its kind. Discovered in a limestone cave in Borneo, the remains pre-date the previous oldest known case of limb amputation by more than 20,000 years. The person appears to have survived for at least six to nine years after the surgery.

Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 9:45am

Two new trials find no link between vitamin D supplements and reduced risk of COVID-19

Two large clinical trials published by The BMJ today show that boosting vitamin D levels in adults during the SARS-CoV-2 pandemic was not associated with protection against respiratory tract infections or COVID-19.

Vitamin D metabolites have long been recognized to support innate immune responses to respiratory viruses and bacteria, and some studies have shown that vitamin D may protect against respiratory tract infections, particularly among those who are vitamin D-deficient.

Vitamin D has therefore received much attention for its potential role in preventing and treating COVID-19, but most studies published so far are observational and have shown mixed results.

The first trial was carried out in the UK between December 2020 and June 2021 and involved 6,200 adults (16 years and over) not using vitamin D supplements at enrollment.

Half (3,100 participants) were offered a vitamin D blood test and those found to have low vitamin D levels (2,674; 86%) received either 3200 IU/day or 800 IU/day of vitamin D supplements for six months, while the other half (controls) received no test or supplements.

Neither of the vitamin D doses showed any effect on diagnosed acute respiratory tract infections or lateral flow test or RT-PCR-confirmed COVID-19 cases over a six-month follow-up period. The number of adverse events was similar between groups, and no serious adverse event was attributed to study supplements.

The second trial was conducted in Norway between November 2020 and June 2021 using cod liver oil, which contains low doses of vitamin D and vitamin A as well as omega-3 fatty acids.

A total of 34,741 adults (18-75 years) who were not using vitamin D supplements received either 5 mL cod liver oil or 5 mL placebo (corn oil) daily for six months. The majority of participants (86%) who were tested had adequate vitamin D levels at the start of the study.

Again, the researchers found no effect of cod liver oil on acute respiratory infections or PCR-confirmed COVID-19, compared with placebo. The cod liver oil group had no more side effects than the placebo group and only low-grade side effects were reported.

Effect of a test-and-treat approach to vitamin D supplementation on risk of all cause acute respiratory tract infection and covid-19: phase 3 randomised controlled trial (CORONAVIT), The BMJ (2022). DOI: 10.1136/bmj-2022-071230

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

Intelligent microscopes for detecting rare biological events

Now researchers need not wait for hours together to image bacterial cells division

Biophysicists have now found a way to automate microscope control for imaging biological events in detail while limiting stress on the sample, all with the help of artificial neural networks. Their technique works for bacterial cell division, and for mitochondrial division. The details of their intelligent microscope are described in Nature Methods.

Suliana Manley, Event-driven acquisition for content-enriched microscopy, Nature Methods (2022). DOI: 10.1038/s41592-022-01589-x. www.nature.com/articles/s41592-022-01589-x

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

Modern humans generate more brain neurons than Neandertals

What makes modern humans unique has long been a driving force for researchers. Comparisons with our closest relatives, the Neandertals, therefore provide fascinating insights. The increase in brain size, and in neuron production during brain development, are considered to be major factors for the increased cognitive abilities that occurred during human evolution. However, while both Neandertals and modern humans develop brains of similar size, very little is known about whether modern human and Neandertal brains may have differed in terms of their neuron production during development.

Researchers now show that the modern human variant of the protein TKTL1, which differs by only a single amino acid from the Neandertal variant, increases one type of brain progenitor cells, called basal radial glia, in the modern human brain. Basal radial glial cells generate the majority of the neurons in the developing neocortex, a part of the brain that is crucial for many cognitive abilities. As TKTL1 activity is particularly high in the frontal lobe of the fetal human brain, the researchers conclude that this single human-specific amino acid substitution in TKTL1 underlies a greater neuron production in the developing frontal lobe of the neocortex in modern humans than Neandertals.

Only a small number of proteins have differences in the sequence of their amino acids—the building blocks of proteins—between modern humans and our extinct relatives, the Neandertals and Denisovans. The biological significance of these differences for the development of the modern human brain is largely unknown. In fact, both, modern humans and Neandertals, feature a brain, and notably a neocortex, of similar size, but whether this similar neocortex size implies a similar number of neurons remains unclear.

The researchers focus on one of these proteins that presents a single amino acid change in essentially all modern humans compared to Neandertals, the protein transketolase-like 1 (TKTL1). Specifically, in modern humans TKTL1 contains an arginine at the sequence position in question, whereas in Neandertal TKTL1 it is the related amino acid lysine. In the fetal human neocortex, TKTL1 is found in neocortical progenitor cells, the cells from which all cortical neurons derive. Notably, the level of TKTL1 is highest in the progenitor cells of the frontal lobe.

Researchers observed that basal radial glial cells, the type of neocortical progenitors thought to be the driving force for a bigger brain, increased with the modern human variant of TKTL1 but not with the Neandertal variant. As a consequence, the brains of mouse embryos with the modern human TKTL1 contained more neurons.

They found that with the Neandertal-type of amino acid in TKTL1, fewer basal radial glial cells were produced than with the modern human-type and, as a consequence, also fewer neurons. This shows us that even though we do not know how many neurons the Neandertal brain had, we can assume that modern humans have more neurons in the frontal lobe of the brain, where TKTL1 activity is highest, than Neandertals.

Anneline Pinson et al, Human TKTL1 implies greater neurogenesis in frontal neocortex of modern humans than Neandertals, Science (2022). DOI: 10.1126/science.abl6422. www.science.org/doi/10.1126/science.abl6422

Comment by Dr. Krishna Kumari Challa on September 9, 2022 at 9:10am

Physicists invent intelligent quantum sensor of light waves

Physicists have demonstrated an atomically thin, intelligent quantum sensor that can simultaneously detect all the fundamental properties of an incoming light wave.

The research, published April 13 in the journal Nature, demonstrates a new concept based on quantum geometry that could find use in health care, deep-space exploration and remote-sensing applications.

Typically, when you want to characterize a wave of light, you have to use different instruments to gather information, such as the intensity, wavelength and polarization state of the light. Those instruments are bulky and can occupy a significant area on an optical table. Now we have a single device—just a tiny and thin chip—that can determine all these properties simultaneously in a very short time.

The device exploits the unique physical properties of a novel family of two-dimensional materials called moiré metamaterials. The 2D materials have periodic structures and are atomically thin. If two layers of such a material are overlaid with a small rotational twist, a moiré pattern with an emergent, orders-of-magnitude larger periodicity can form. The resulting moiré metamaterial yields electronic properties that differ significantly from those exhibited by a single layer alone or by two naturally aligned layers.

The sensing device that physicists now chose to demonstrate their new idea incorporates two layers of relatively twisted, naturally occurring bilayer graphene, for a total of four atomic layers.

Chun Ning Lau et al, Reproducibility in the fabrication and physics of moiré materials, Nature (2022). DOI: 10.1038/s41586-021-04173-z

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