Knowledge Update

​New York, May 3 (IANS) Antibiotics are essential for fighting bacterial infection, but, paradoxically, they can also make the body more prone to infection and diarrohea by allowing gut pathogens to “breathe”, says a study.

Antibiotics benefit pathogen growth by disrupting oxygen levels and fibre processing in the gut, the study said.

The findings, published in the journal Cell Host Microbe, could lead to development of new strategies to prevent the side effects of antibiotic treatment.

Exactly how the resident "good" microbes in the gut protect against pathogens, such as Salmonella, and how antibiotic treatments foster growth of disease-causing microbes have been poorly understood.

But the new research in a mouse model has identified the chain of events that occur within the gut lumen after antibiotic treatment that allow "bad" bugs to flourish.

The process begins with antibiotics depleting "good" bacteria in the gut, including those that breakdown fibre from vegetables to create butyrate, an essential organic acid that cells lining the large intestine need as an energy source to absorb water, said lead researcher Andreas Baumler, professor at University of California Davis Health System in the US.

The reduced ability to metabolise fibre prevents these cells from consuming oxygen, increasing oxygen levels in the gut lumen that favour the growth of Salmonella.

Most persons infected with Salmonella develop diarrohea, fever, and abdominal cramps 12 to 72 hours after infection, according to the US Centres for Disease Control and Prevention (CDC).

"Unlike Clostridia and other beneficial microbes in the gut, which grow anaerobically, or in the complete absence of oxygen, Salmonella flourished in the newly created oxygen-rich micro environment after antibiotic treatment," Baumler said. 

"In essence, antibiotics enabled pathogens in the gut to breathe," Baumler noted.​

New York, May 3 (IANS) There are nearly one trillion species on the Earth while 99.999 percent of species still remain undiscovered, the largest-ever analysis of microbial data has revealed.

Biologists from Indiana University have combined microbial, plant and animal community datasets from government, academic and citizen science sources, resulting in the largest compilation of its kind.

Altogether, the data represents over 5.6 million microscopic and non-microscopic species from 35,000 locations across all the world's oceans and continents, except Antarctica.

Estimating the number of species on the Earth is among the great challenges in biology.

"Our study combines the largest available datasets with ecological models and new ecological rules for how biodiversity relates to abundance. This gave us a new and rigorous estimate for the number of microbial species on Earth," said associate professor Jay T Lennon.

The advent of new genetic sequencing technology provides an unprecedented large pool of new information, he added.

These data sources pull together 20,376 sampling efforts on bacteria, archaea and microscopic fungi and 14,862 sampling efforts on communities of trees, birds and mammals.

"This research offers a view of the extensive diversity of microbes on Earth. It also highlights how much of that diversity still remains to be discovered and described," added Simon Malcomber, director of the National Science Foundation's Dimensions of Biodiversity programme.

The estimate, based on the intersection of large datasets and universal scaling laws, appeared in the journal Proceedings of the National Academy of Sciences.

The results suggest that actually identifying every microbial species on the Earth is an almost unimaginably huge challenge.

To put the task in perspective, the Earth Microbiome Project -- a global multidisciplinary project to identify microscope organisms -- has so far cataloged less than 10 million species.

"Of those cataloged species, only about 10,000 have ever been grown in a lab, and fewer than 100,000 have classified sequences," Lennon said.

"The results show that this leaves 100,000 times more microorganisms awaiting discovery -- and 100 million to be fully explored. Microbial biodiversity, it appears, is greater than ever imagined," the authors noted.​

​London, May 2 (IANS) Treating patients who have early stage lung cancer with radiotherapy can increase their risk of death from causes other than cancer, says a study.

In particular, they found that high doses to the left atrium of the heart and the superior vena cava had the strongest association and increased risk of non-cancer death.

"Our results show that even within a few years a radiation dose to the heart is associated with an increased risk of non-cancer death for early stage lung cancer patients, and they indicate which regions of the heart possibly play a role,” said Barbara Stam from the Netherlands Cancer Institute, Amsterdam.

"Validation and further investigations into the exact mechanisms and which heart structures are critical is warranted, but clinically, this could mean that patients might benefit from heart-sparing radiotherapy,” Stam noted.

The findings were presented at the European Society for Radiotherapy & Oncology's ESTRO 35 conference on Monday.

The researchers analysed data from 565 patients diagnosed with early stage non-small cell lung cancer (NSCLC) between 2006-2013 in five institutions in Europe and North America , who were treated with a type of radiotherapy called stereotactic body radiation therapy (SBRT). 

SBRT is a specialised type of external beam radiation therapy that can focus radiation beams with extreme accuracy on a tumour, thereby minimising the effect on nearby organs. 

With multiple organs nearby, minimising the dose to one organ is likely to result in a higher dose in another organ.

In order to work out how much radiation was delivered to which sub-structures of the heart, the researchers created a "template" image of the heart and its sub-structures on to which they could map the anatomy of each of the 565 patients -- a process called deformable image registration. 

Radiotherapy for lung cancer patients is linked to increased risk of non-cancer deaths, the findings showed.

As a result of the new findings, researchers said they would be investigating ways to deliver radiotherapy while sparing the crucial heart structures as much as possible​

​London, May 2 (IANS) In a major step towards bringing to the clinic a “game-changing” new antibiotic that was discovered last year, a team of University of Lincoln researchers, including one of Indian-origin, has successfully produced two synthetic derivatives of Teixobactin.

Last year, the discovery of the antibiotic Teixobactin by researchers in the US was hailed as a ‘game-changer’ in the fight against antimicrobial resistance as it is the world’s first known antibiotic capable of destroying “drug resistant” bacteria.

The last new class of antibiotics was discovered nearly 30 years ago.

However, in order for Teixobactin to be developed as a potential drug treatment, several versions of the antibiotic must be produced via chemical synthesis in order to overcome the hurdles of drug development. 

Researchers in laboratories around the world have been working towards this objective since last year’s breakthrough. 

Now Ishwar Singh from the University of Lincoln and his colleagues have become the first group of scientists to synthetically produce two derivatives of Teixobactin, an official statement said.

"Teixobactin originally evolved in soil to kill the bacteria around it, so our challenge was to produce the antibiotic synthetically,” said Singh, a specialist in novel drug design at Lincoln’s School of Pharmacy.

"The method we created to do this uses commercially available ‘building blocks’ and has a single purification step, and we are delighted with the results - we are now able to present the total synthesis of two derivatives of Teixobactin,” Singh noted.

The findings appeared online in the journal Chemical Communications. 

The bacteria against which Teixobactin is effective have, thus far, not shown any detectable resistance and given its mechanisms of attack, scientists are also confident that this is unlikely to occur in the future.

"The process of bringing an antibiotic to clinic is an extremely lengthy one and can often take around 10-15 years. There is much more extensive research and testing to be carried out before we can even consider Teixobactin as a viable medical treatment,” Singh added​

​New York, May 2 (IANS) More than one-third of US children with autism spectrum disorders have wandered away from a safe environment within the past 12 months, new research shows.

"Elopement, or wandering, places children with autism spectrum disorders at risk of serious injury or even death once they are away from adult supervision," said senior investigator Andrew Adesman, chief of developmental pediatrics at Cohen Children's Medical Centre (CCMC) of New York.

Autism spectrum disorder (ASD) referes to a group of complex brain development disorders characterised by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviours.

"Despite its clear relevance to the safety of these children, there has been little research on elopement," Adesman pointed out.

The researchers examined data from a Centres for Disease Control and Prevention survey of parents and guardians of more than 4,000 children ages six to 17 diagnosed with ASD, an intellectual disability or developmental delay. 

For their studies, analysis was restricted to only those children with ASD.

The researchers found that wanderers were more likely to not realise when they are in danger, to have difficulty distinguishing between strangers and familiar people, to show sudden mood changes, to over-react to situations and people, to get angry quickly, and to panic in new situations or if change occurs.

The researchers also found that wanderers were more than twice as likely to elope from a public place, compared to their home or school. 

The findings were presented at the annual meeting of the Pediatric Academic Societies in Baltimore, US.

"As the prevalence of autism spectrum disorders in the United States continues to rise, there is a need to better understand the behaviors that may compromise the safety and well-being of these children," principal investigator of the study Bridget Kiely from CCMC noted.​

​London, May 2 (IANS) Two of Britain's leading charities have announced their biggest ever donations for research to curb dementia.

The Alzheimer's Society and Alzheimer's Research UK on Sunday announced their biggest ever financial commitments to the cause, each pledging 50 million pounds ($73 million), Xinhua news agency reported.

The 100 million pounds will be added to the $220 million already announced by Prime Minister David Cameron to pay for Britain's first ever Dementia Research Institute.

The Medical Research Council also announced on Sunday the launch of a search for an outstanding scientist to head the new institute, expected to be an expert to drive forward world class research.

The new institute, due to open in 2020, will bring together scientists and experts from across the globe to transform the landscape of dementia, one of the biggest conditions facing the human race.

The research will help to drive new approaches to diagnosis, treatment, care provision and ultimately prevention of the disease.

Science Minister Jo Johnson said: "We want Britain to lead the way in tackling this terrible condition, and scientific research and understanding is crucial to this."

Government officials estimate that in 20 years the number of Britons suffering from dementia will be around 1.7 million, double the current figure. 

​New York, May 1 (IANS) Imagine a brain-machine interface that does not just figure out what sounds you want to make, but what you want to say.

Researchers have taken a step in that direction by building a "semantic atlas" that shows in vivid colours how the brain organises different words by their meanings.

The atlas identifies brain areas that respond to words that have similar meanings.

Detailed maps showing how the brain organises different words by their meanings could eventually help give voice to those who cannot speak, such as people who have had a stroke, brain damage or motor neuron diseases such as ALS.

While mind-reading technology remains far off on the horizon, charting language organisation in the brain brings decoding inner dialogue a step closer to reality, the researchers said.

"This discovery paves the way for brain-machine interfaces that can interpret the meaning of what people want to express," said study lead author Alex Huth, postdoctoral researcher in neuroscience at University of California, Berkeley.

For example, clinicians could track the brain activity of patients who have difficulty communicating and then match that data to semantic language maps to determine what their patients are trying to express.

Another potential application is a decoder that translates what you say into another language as you speak.

The findings, published in the journal Nature, are based on a brain imaging study that recorded neural activity while study volunteers listened to stories from "The Moth Radio Hour" - a public radio show in which people recount humorous and poignant autobiographical experiences.

They showed that at least on third of the brain's cerebral cortex -- including areas dedicated to high-level cognition -- is involved in language processing.

Notably, the study found that different people share similar language maps.

"The similarity in semantic topography across different subjects is really surprising," Huth said.​

​New York, May 1 (IANS) Have you ever been bullied in school, college or social media? A new study shows that the combined effect of both face-to-face and cyber-bullying may increase the risk of aggressive behaviour in teenagers.

These teenagers were twice as likely to show aggressive behaviours themselves like verbal hostility, physical fighting and damaging property.

Teenagers who were victims of both face-to-face and cyber-bullying, representing three percent of the youth, were more than twice as likely as those experiencing just one form of bullying to engage in aggressive behaviours.

"Victims who had been subjected to multiple forms of peer aggression were at increasingly greater risk of showing aggressive behaviours themselves," said senior author Andrew Adesman from Cohen Children's Medical Center of New York.

"These behaviours may involve retaliatory measures against their aggressors, acting aggressive in order to fend off future bullying attempts, or worse, learning by example and engaging in bullying of previously uninvolved peers," Adesman added.

The team analysed adolescents between ages 10 and 17 on how they behaved after experiencing face-to-face bullying, cyber-bullying and both.

The results revealed that overall, 43 percent of the teens in the study reported having been the victim of face-to-face bullying, while seven percent reported that they experienced some form of cyber-bullying.

The teenagers who experienced both forms of victimisation, 38 percent showed aggressive behaviour, compared with 15 percent of those who were cyber-bullied and 4 percent of those were victims of face-to-face bullying.

"This phenomenon may lead to a vicious cycle whereby bullies create bullies out of those they victimize."

The study was scheduled to be presented at the ongoing Pediatric Academic Societies 2016 Meeting in Baltimore in the US.​

New York, May 1 (IANS) To cut down the waste that fashion industry generates, a team of US researchers has developed a new fibre from a green tea by-product that is 100 percent biodegradable.

Young-A Lee and her research team have designed a vest and shoe prototype from the cellulosic fibre grown in LeBaron Hall on the Iowa State University campus, US, and testing it if it is a viable alternative.

"Fashion is an ephemeral expression of culture, art and technology manifesting itself in form. Fashion companies keep producing new materials and clothing to fulfill consumers' desire and needs," Lee said.

"These items eventually go underground and take spaces of Earth like other trash," Lee, who is an associate professor of apparel, merchandising and design at Iowa State, added.

LeBaron Hall has plastic bins in which all trash is dumped. The bins contain a gel-like film consisting of cellulose fibres --- a byproduct of kombucha tea -- that feeds off a mixture of vinegar and sugar.

The cellulose fibre reduces waste by creating a continuous cycle of reuse or regeneration, what is known as cradle-to-cradle design. Even if clothing is recycled or repurposed, it still eventually ends up in the trash.

The material has been tested for other applications, such as cosmetics, foods and biomedical tissue for wound dressing but it is relatively new to the apparel industry.

The fact that the fibre is 100 percent biodegradable is a significant benefit for the fashion industry, which by its very nature generates a lot of waste.

Lee said she envisions a truly sustainable fabric or material that is biodegradable and goes back into the soil as a nutrient rather than taking up space in a landfill.​

​New York, May 1 (IANS) Researchers have found that an elusive brain receptor may play an important role in the death of neurons from neurological diseases.

Strokes, seizures, traumatic brain injury and schizophrenia leads to persistent, widespread acidity around neurons in the brain.

Analysing NMDA (N-methyl-D-aspartate) - a family of brain receptors that are critical to learning and memory - the researchers found that one of these receptors called N3A functions through a different mechanism than all other NMDA receptors.

"We found that in contrast to all other NMDA receptors, acidity can reactivate dormant N3A receptors," said one of the researchers Gabriela K. Popescu, professor at University of Buffalo, in US.

The results, published in Scientific Reports, showed that, as acidity increases after a stroke or an epileptic seizure, reactivation of N3A receptors may be one reason why neurons die after these neurologic events.

"When the N3A receptors were exposed to acidic conditions they reactivate, causing neurons to become more sensitive to the neurotransmitter glutamate, which can, under certain circumstances, kill them," said lead author Kirstie A. Cummings, doctoral candidate.

Also, N3A proteins were found to be more abundant in brains of people with schizophrenia -- a disease associated with high acidity in the brain, causes brains to shrink.

Finding ways to prevent acidification or the reactivation of N3A receptors may prevent brain damage from strokes or seizures, the researchers suggested.

In addition, the researchers have identified the site on the receptor where acidity acts to reactivate these receptors, a different location from the site where acidity acts to inhibit all other NMDA receptors.

"This site is new and unique and thus can be used to make drugs that are very specific to the N3A receptor," Popescu said.​