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Comment by Dr. Krishna Kumari Challa on January 23, 2021 at 10:12am

How Do Bacteria Become Resistant to Antibiotics?

Comment by Dr. Krishna Kumari Challa on January 23, 2021 at 10:03am

Combined river flows could send up to 3 billion microplastics a day into the Bay of Bengal

The Ganges River—with the combined flows of the Brahmaputra and Meghna rivers—could be responsible for up to 3 billion microplastic particles entering the Bay of Bengal every day, according to new research.

The study represents the first investigation of microplastic abundance, characteristics and seasonal variation along the river and was conducted using samples collected by an international team of scientists as part of the National Geographic Society's Sea to Source: Ganges expedition.

Over two expeditions in 2019, 120 samples (60 each in pre- and post-monsoon conditions) were gathered at 10 sites by pumping river water through a mesh filter to capture any particles.

The samples were then analysed in laboratories at the University of Plymouth with microplastics found in 43 (71.6%) of the samples taken pre-monsoon, and 37 (61.6%) post-monsoon.

More than 90% of the microplastics found were fibres and, among them, rayon (54%) and acrylic (24%) - both of which are commonly used in clothing—were the most abundant.

Combining predicted microplastic concentration at the mouth of the river (Bhola, Bangladesh) with the discharge of the river, scientists estimate that between 1 billion and 3 billion microplastics might be being released from the Ganges Brahmaputra Meghna River Basin every day.

Imogen E. Napper et al, The abundance and characteristics of microplastics in surface water in the transboundary Ganges River, Environmental Pollution (2021). DOI: 10.1016/j.envpol.2020.116348

https://phys.org/news/2021-01-combined-river-billion-microplastics-...

Comment by Dr. Krishna Kumari Challa on January 23, 2021 at 9:22am

MRI helps unravel the mysteries of sleep

  The state of consciousness changes significantly during stages of deep sleep, just as it does in a coma or under general anesthesia. Scientists have long thought, but couldn't be certain, that brain activity declines during sleep. Most research on sleep is conducted using electroencephalography (EEG), a method that entails measuring brain activity through electrodes placed along a patient's scalp. However researchers now  investigated brain activity during sleep using magnetic resonance imaging (MRI).  

  MRI scans measure neural activity by detecting the hemodynamic response of structures throughout the brain, thereby providing important information in addition to EEGs.  During these experiments, researchers relied upon EEG to identify when the study participants had fallen asleep and pinpoint the different stages of sleep. Then they examined the MRI images to generate spatial maps of neural activity and determine different brain states. 

The brain activity data were recorded over a period of nearly two hours while participants were sleeping in an MRI machine. 

  After checking, analyzing and comparing all the data, what they found was surprising. They calculated exactly how many times networks made up of different parts of the brain became active during each stage of sleep and discovered that during light stages of sleep—that is, between when you fall asleep and when you enter a state of deep sleep—overall, brain activity decreases. But communication among different parts of the brain becomes much more dynamic - that's due to the instability of brain states during this phase. 

  What 's really surprising  in all this was the resulting paradox. During the transition phase from light to deep sleep, local brain activity increased and mutual interaction decreased. This indicates the inability of brain networks to synchronize.  

 Consciousness is generally associated with neural networks that may be linked to our introspection processes, episodic memory and spontaneous thought.   

Researchers  observed that the network between the anterior and posterior regions broke down, and this became increasingly pronounced with increasing sleep depth. A similar breakdown in neural networks was also seen in the cerebellum, which is typically associated with motor control.

These  findings are a first step toward a better understanding of states of consciousness during sleep. They show that consciousness is the result of interactions between different brain regions, and not in localized brain activity.

  By studying how our state of consciousness is altered during different stages of sleep, and what that means in terms of brain network activity, we can better understand and account for the wide range of brain functions that characterize us as human beings.  

Anjali Tarun et al, NREM sleep stages specifically alter dynamical integration of large-scale brain networks, iScience (2020). DOI: 10.1016/j.isci.2020.101923

https://medicalxpress.com/news/2021-01-mri-unravel-mysteries.html?u...

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Comment by Dr. Krishna Kumari Challa on January 23, 2021 at 9:01am

Scientists solve a 100-year-old mystery about cancer

In 1921, German physician Otto Warburg observed that cancer cells harvest energy from glucose sugar in a strangely inefficient manner: rather than "burn" it using oxygen, cancer cells do what yeast do—they ferment it. This oxygen-independent process occurs quickly, but leaves much of the energy in glucose untapped.  

Various hypotheses to explain the Warburg effect have been proposed over the years, including the idea that cancer cells have defective mitochondria—their "energy factories"—and therefore cannot perform the controlled burning of glucose. But none of these explanations has withstood the test of time. (Cancer cells' mitochondria work just fine, for example.)
Now a research team  offers a new answer, based on a hefty set of genetic and biochemical experiments and published January 21 in the journal Science.It comes down to a previously unappreciated link between Warburg metabolism and the activity of a powerhouse enzyme in the cell called PI3 kinase. PI3 kinase is a key signaling molecule that functions almost like a commander-in-chief of cell metabolism. Most of the energy-costly cellular events in cells, including cell division, occur only when PI3 kinase gives the cue. As cells shift to Warburg metabolism, the activity of PI3 kinase is increased, and in turn, the cells' commitment to divide is strengthened. It's a bit like giving the commander-in-chief a megaphone.The findings revise the commonly accepted view among biochemists that sees metabolism as secondary to cell signaling. They also suggest that targeting metabolism could be an effective way to thwart cancer growth.

As with immune cells, cancer cells may employ Warburg metabolism as a way to sustain the activity of this signaling pathway and therefore ensure their continued growth and division.

The results raise the intriguing possibility that doctors could curb cancer growth by blocking the activity of LDHA—the Warburg "switch."

 Ke Xu et al, Glycolysis fuels phosphoinositide 3-kinase signaling to bolster T cell immunity, Science (2021). DOI: 10.1126/science.abb2683

https://medicalxpress.com/news/2021-01-scientists-year-old-mystery-...

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Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 10:32am

S. Africa virus strain poses 're-infection risk': study

The coronavirus variant detected in South Africa poses a "significant re-infection risk" and raises concerns over vaccine effectiveness, according to preliminary research Wednesday, as separate studies suggested the British strain would likely be constrained by immunisations. Several new variants -- each with a cluster of genetic mutations -- have emerged in recent weeks, sparking fears over an increase in infectiousness as well as suggestions that the virus could begin to elude immune response, whether from prior infection or a vaccine. These new variants, detected from Britain, South Africa and Brazil, have mutations to the virus' spike protein, which enables the virus to latch onto human cells and therefore plays a key role in driving infections. But it is one mutation in particular -- known as E484K and present in the variants detected in South Africa and Brazil but not the one from Britain -- that has experts particularly worried about immunity "escape".

They found that it was resistant to neutralising antibodies built up from prior infection, but said more research was needed into the effectiveness of other parts of the immune response.

The 501Y.V2 lineage, which contains nine spike mutations and rapidly emerged in South Africa during the second half of 2020, is largely resistant to neutralising antibodies elicited by infection with previously circulating lineages. This suggests that, despite the many people who have already been infected with SARS-CoV-2 globally and are presumed to have accumulated some level of immunity, new variants such as 501Y.V2 pose a significant re-infection risk.

The researchers added that this might also affect the use of convalescent plasma as a treatment for Covid-19. They also suggested it could have "implications" for vaccines developed based on immune responses to the virus's spike protein.

https://researchnews.cc/news/4730/S--Africa-virus-strain-poses--re-...

Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 10:05am

Sci-COM : Storytelling can be a powerful tool for science

Credible science communication and storytelling are not mutually exclusive — they can be great allies.

In contrast with straight communication of experimental results, telling individual research stories portrays science as a human-driven endeavour, full of successes, uncertainties, missteps and failures, which in turn promotes transparency. What really matters is what story is being told and by whom.

https://www.nature.com/articles/d41586-021-00108-w?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 9:31am

Bubble micro-robots!

Lasers create miniature robots from bubbles

Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 9:26am

Cancer can be precisely diagnosed using a urine test with artificia...

Prostate cancer is one of the most common cancers among men. Patients are determined to have prostate cancer primarily based on PSA, a cancer factor in blood. However, as diagnostic accuracy is as low as 30%, a considerable number of patients undergo additional invasive biopsy and thus suffer from resultant side effects, such as bleeding and pain.

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Scientists shine new light on heat-damaged hair

A new technique allowed researchers to observe in greater detail how heat alters keratin proteins, helping in their search for ingredients that can prevent heat-damaged hair.

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As more bacteria grow resistant to antibiotics, scientists are figh...

Scottish bacteriologist Alexander Fleming's discovery of penicillin, the world's first antibiotic, saved countless lives. But even as the bacteria killer first hit the U.S. market—in the closing months of World War II—Fleming warned the world about what penicillin might unleash.

Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 9:25am

Antibiotic resistance may spread even more easily than expected

Pathogenic bacteria in humans are developing resistance to antibiotics much faster than expected. Now, computational research shows that one reason could be significant genetic transfer between bacteria in our ecosystems and to humans. This work has also led to new tools for resistance researchers.

Completely different species of bacteria can spread resistance genes to each other through plasmids—small DNA molecules where bacteria store some of their genes outside the chromosome. When two bacterial cells come into contact, they can copy plasmids to each other. This is called conjugation, and it is the most important mechanism for spreading antibiotic resistance.

In recent years, we've seen that resistance genes spread to human pathogens to a much greater degree than anyone expected.

Many of the genes appear to have originated in a wide array of bacterial species and environments, such as soil, water and plant bacteria. This has been difficult to explain, because although conjugation is very common, we've thought that there was a distinct limitation for which bacterial species can transfer plasmids to each other. Plasmids belong to different mobility groups, or MOB groups, so they can't transfer between just any bacterial species.

The results show, among other things, that:

• The number of oriT regions may be almost eight times higher than those found with the standard method used today.
• The number of mobile plasmids may be twice as high as previously known.
• The number of bacterial species that have mobile plasmids may be almost twice as high as previously known.
• Over half of these plasmids have oriT regions that match a conjugation enzyme from another plasmid that has previously been classified in a different MOB group. This means that they could be transferred by one of these plasmids that happens to be in the same bacterial cell.

The last part means that there may be transfer mechanisms between large numbers of bacterial species and environments where we previously believed there were barriers.

Jan Zrimec, Multiple plasmid origin‐of‐transfer regions might aid the spread of antimicrobial resistance to human pathogens, MicrobiologyOpen (2020). DOI: 10.1002/mbo3.1129

https://phys.org/news/2021-01-antibiotic-resistance-easily.html?utm...

Comment by Dr. Krishna Kumari Challa on January 22, 2021 at 9:11am

Some COVID-19 mutations may dampen vaccine effectiveness

Scientists are reporting troubling signs that some recent mutations of the virus that causes COVID-19 may modestly curb the effectiveness of two current vaccines, although they stress that the shots still protect against the disease.

Researchers expressed concern Wednesday about the preliminary findings, in large part because they suggest that future mutations could undermine vaccines.

A different, more limited study out Wednesday gave encouraging news about one vaccine's protection against some of the mutations.

One way vaccines work is to prompt the immune system to make antibodies that block the virus from infecting cells. The Rockefeller researchers got blood samples from 20 people who had received either the Moderna or Pfizer vaccine and tested their antibodies against various virus mutations in the lab.

With some, the antibodies didn't work as well against the virus—activity was one-to-threefold less, depending on the mutation. It's a small difference but it is definitely a difference. The antibody response is "not as good" at blocking the virus.

Earlier research established that the two vaccines are about 95% effective in preventing COVID-19 illness.

The latest findings were posted late Tuesday on an online website for researchers.

We don't want people thinking that the current vaccine is already outdated. That's absolutely not true. There's still immunity here ... a good level of protection but the mutations "do in fact reduce how well our immune response is recognizing the virus."

We've got an arms race between the vaccines and the virus. The slower we roll out vaccine around the world, the more opportunities we give this virus to escape" and develop mutations

https://www.biorxiv.org/content/10.1101/2021.01.15.426911v1

https://medicalxpress.com/news/2021-01-covid-mutations-dampen-vacci...

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