Knowledge Update

Beijing, May 3 (IANS) A team of Chinese and French speleologists have determined that China's longest cave is around 186 km long, 25 km longer than a measurement from 2014.

The cave researchers conducted a joint expedition from April 16 to 28 at Shuanghe Cave in China's Guizhou province, Xinhua news agency reported.

They also discovered fossils of vertebrates at 13 sites in the cave. Most of them belonged to giant pandas, while others include possible bear and elephant skeletons.

The karst cave was uncovered in the late 1980s, and more than 10 large surveys have been carried out since by Chinese and foreign researchers. The surveys have found 203 entrances to the cave.​

​New York, May 4 (IANS) Overturning a common perception that herbs are safe because they have been used for many years, researchers have warned that long-term use of herbal remedies is no guarantee of their safety as many herbs may contain toxic or carcinogenic substances.

In a commentary published in the journal EMBO reports, researchers from Baylor College of Medicine and Stony Brook University discussed scientific evidence showing that the plant Aristolochia can cause aristolochic acid nephropathy (AAN). 

People with this condition experience interstitial nephritis, renal failure and cancers of the urinary track.

In Taiwan, according to the national prescription database, between 1997 and 2003, eight million people were exposed to herbal products containing Aristolochia, the authors remarked.

Studies of patients with renal failure and cancer in Taiwan and China show that tens of millions of people in those countries are at risk of AAN.

In genetically susceptible people, consuming Aristolochia can lead to the formation of complexes between aristolactam, a compound in Aristolachia, and DNA in renal tissues. 

These complexes lead to mutations in the TP53 tumour suppressor gene, which in turn initiate the process toward kidney cancer. Additional studies have shown that this process may also lead to the development of cancer in the liver and the bladder, researchers Donald Marcus, professor emeritus at Baylor and Arthur Grollman, distinguished professor of pharmacological sciences at Stony Brook University, explained.

Although Aristolochia has been used as a herbal remedy for more than 2,000 years, "the intrinsic toxicities were not recognised, owing, in large part, to the latency period between exposure and the onset of symptomatic disease, and, in part, to genetic determinants that confer susceptibility to only approximately five percent of those exposed to this herb", said the authors. 

The long-term scientific study of AAN revealed the association of the disease with Aristolochia.

"The history of Aristolachia indicates that other herbs that have been used for a long time may also have toxic and/or carcinogenic compounds," said the authors.

"It is prudent to assume that many herbs may contain toxic or carcinogenic substances that can cause subsequent health problems for humans," they noted.

Other herbal products and traditional medicines are responsible for severe adverse events in Africa and Asia, but in these cases epidemiological data are lacking, said the researchers suggesting that herbal remedies may be an overlooked global health hazard.​

New York, May 3 (IANS) Scientists have discovered three new species of mouse lemurs - the smallest primates in the world - in Madagascar.

Twenty years ago, there were only two species of mouse lemurs. Today, including the newly-discovered species Microcebus ganzhorni, Microcebus manitatra and Microcebus boraha, mouse lemurs comprise 24 species, which are only found in the highly biodiverse island of Madagascar.

"We didn't go into this work looking for a new species, but there was no real way to get around the fact that there are three new species here to describe," said lead study author Scott Hotaling from University of Kentucky in the US.

The findings were published in the journal Molecular Ecology.

"From a conservation perspective, knowing what's there is important," Hotaling said. 

"These animals are facing diminishing habitats and tremendous pressures," Hotaling pointed out.

According to the International Union for Conservation of Nature's Red List, 94 percent of lemurs are threatened with extinction. 

Of the 101 surviving lemur species, 22 are critically endangered, 48 are endangered and 20 are vulnerable - making them one of the most threatened groups of vertebrates on Earth.

But almost as important as the species discovered is how they were discovered -- using recently developed methods that allowed researchers to statistically model the evolutionary process on University of Kentucky's supercomputer.

The researchers believed that this objective approach to assessing genetic differences between individuals could have significant potential for clarifying diversity in other species.​

​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​

​Tokyo, May 2 (IANS) The G7 energy ministers on Monday agreed to step up energy security and boost investment to counter instability caused by the fall in crude oil prices.

Ministers from Japan, Canada, Germany, Italy, the US, Britain and France and representatives from the International Energy Agency (IEA) and The International Renewable

​New York, May 2 (IANS) Keeping tabs on tweets may be an effective tool to help prepare for -- and prevent -- increases in asthma emergencies, say researchers, including one of Indian-origin.

​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.​