Knowledge Update

​Toronto, April 26 (IANS) A team of international researchers has found that blocking a key protein may prevent the formation of brain tumour, as well as lead to the development of new therapies for a deadly and incurable cancer.

The findings showed that blocking OSMR (Oncostatin M Receptor) -- a protein required for the formation of glioblastoma tumours which are one of the most deadly cancers, resistant to radiation, chemotherapy and difficult to remove with surgery -- can halt the formation of the tumour.

"The fact that most patients with these brain tumours live only 16 months is just heartbreaking," said lead researcher Arezu Jahani-Asl, assistant professor at at McGill University in Canada.

The researchers found that the higher the OSMR expression in the brain, the faster the patient died.

This was further confirmed in mouse studies, where animals injected with human brain tumour stem cells with low OSMR expression lived 30 percent longer than those infected with tumour stem cells with normal OSMR expression.

In brain cancer only a few kinds of cells have the ability to reproduce to form a whole tumour. If a single one of these brain tumour stem cells is left behind after surgery, it can create a whole new tumour.

The team found that blocking OSMR activity in these cells prevented them from forming tumours in mouse brains.

"Being able to stop tumour formation entirely was a dramatic and stunning result," said one of the researchers Rudnicki, professor at University of Ottawa in Canada.

OSMR activity could be a possible target for future treatments, the researchers noted in the paper published in Nature Neuroscience.

The team studied human brain tumour stem cells taken from 339 human glioblastoma patients and injected in mouse. 

Researchers previously knew that EGFRvIII -- an active form of the epidermal growth factor receptor -- drove tumour formation in glioblastoma, but so far therapies targeting this receptor have not worked against brain cancer.

The results also revelaed that EGFRvIII should be binded with OSMR before it can send out any tumour-forming signals.

This new understanding could pave the way for more effective treatments, not only for glioblastomas, but also for other cancers with highly amplified EGFR expression like breast, lung and cervical cancers, the researchers explained.

"The next step is to find small molecules or antibodies that can shut down the protein OSMR or stop it from interacting with EGFR. But any human treatment targeting this protein is years away," said another researcher Azad Bonni, professor at Washington University in US.​

New York, April 26 (IANS) Continuing to have social interaction is key to keeping your ears sensitive even in old age, suggests new research.

Hearing socially meaningful sounds can change the ear and enable it to better detect those sounds, the findings showed.

"The ear is modifiable," said one of the researchers Walter Wilczynski, professor at Georgia State University in the US. 

"It's plastic. It can change by getting better or worse at picking up signals, depending on particular types of experiences, such as listening to social signals,” Wilczynski explained.

The researchers studied the phenomenon in green treefrogs. Researchers used green treefrogs because they have a simple social system with only one or two vocal calls. 

In the lab, the experimental group heard their species' specific calls every night for 10 consecutive nights as they would in a normal social breeding chorus in the wild, while the control group heard random tones with no social meaning. 

Then the researchers placed electrodes on the skin near the frogs' ears and measured the response of their ears to sound.

"If frogs have a lot of experience hearing their vocal signals, the ones that are behaviourally meaningful to them, their ear changes to help them better cope with processing those signals," Wilczynski said.

The findings were published in the Journal of Experimental Biology.

The findings could have important implications for elderly people in nursing homes or prisoners in solitary confinement, both of whom have little social interaction. 

"My guess is people who have a lot of experience with our social vocal signal, which is our speech, this probably helps keep their sensory system in a healthy state that helps them pick out those signals," Wilczynski said.

The researchers are unsure, however, how this change in the ear occurs or what particular change has been made, although they believe the modification occurs in the inner ear based on electrophysiological tests.​

Sydney, April 26 (IANS) The elderly are often unable to adjust to new surroundings. This is partly due to the deterioration of a brain circuit that plays a key role in goal-directed learning, a new study conducted on mice has found.

The results revealed that the faulty activation of this brain circuit mixes both the new and old learning in the elderly mice, thus causing impairment in their ability to select the most appropriate action in response to a changing environment that leads to confusion.

"Flexibility issues in ageing have long been described in other navigation and spatial memory tasks. Here we describe a similar flexibility problem but applied to goal-directed action, which of course has more detrimental consequences for everyday life and potentially compromises survival," said J. Bertran-Gonzalez of the University of Queensland in Australia. 

This flexibility problem could constitute a first step towards major motivational decline and, in some cases, seed further cognitive conditions and dementia, the researchers noted in the paper published in the journal Neuron.

The team found that the ability to make choices between distinct courses of action depends on a brain region called the striatum, which is located in the forebrain and associated with planning and decision-making. 

However, it has not been clear whether the age-related decline in striatal function impairs initial goal-directed learning per se or simply prevents the updating of this learning in face of new environmental demands.

Further, this decline in behavioural flexibility was also accompanied by the deterioration of a specific pathway in the brain, called the parafascicular-to-cholinergic interneuron pathway (PF-to-CIN), which resulted in faulty activation of striatal neurons.

Disrupting this pathway in young mice reiterated the behavioural deficits observed in old mice, resulting in interference between old and new action-outcome associations. 

The findings show that the age-related decline in the PF-to-CIN pathway impairs the ability of mice to adjust to environmental changes in goal-directed learning tasks.

For the study, the team placed aged mice in a chamber and trained them to press two levers: one to receive a grain-based food reward, and the other to receive a food pellet that was identical except that it had a sweet taste. 

Then the mice were placed in another box, where they were given unrestricted access to only one of the pellets -- grain-based pellets -- for an hour. 

Immediately afterward, the mice were again placed in the original chamber and allowed to choose between the differently flavoured food pellets and both young and old mice preferred to eat the sweetened food pellets.

The researchers next switched the associations, such that pressing lever one resulted in the delivery of sweetened food pellets, whereas lever two presses yielded grain-flavoured pellets. 

Young mice successfully adjusted to this environmental change, pressing lever one to receive the sweetened food pellet after having gorged on the grain-based food pellets, and vice versa. 

However, old mice became confused and pressed the two levers at similar rates.​

​New York, April 26 (IANS) Children with vision problems not correctable with glasses or contact lenses are twice as likely to have a diagnosis of attention deficit/hyperactivity disorder (ADHD) when compared to peers without such disorders, suggests a study.

"Children with vision problems should be monitored for signs and symptoms of ADHD so that this dual impairment of vision and attention can best be addressed," said the study's led author Dawn DeCarlo from the University of Alabama at Birmingham, the US.

The findings appeared in the journal of the American Academy of Optometry. 

The researchers analysed data on more than 75,000 children (aged four to 17) from the 2011-12 National Survey of Children's Health, conducted by the US Centres for Disease Control and Prevention. 

Parents were asked whether they had ever been told their child had some type of vision problem that was not correctable with standard glasses or contact lenses. 

Examples of such conditions include disorders of eye alignment or eye movement, such as strabismus or nystagmus.

A current diagnosis of ADHD was reported for 15.6 percent of children with vision problems, compared to 8.3 percent of those without vision problems. 

The findings add new evidence that children with vision problems not correctable by glasses or contact lenses have a higher prevalence of ADHD. The association is independent of differences in patient and family characteristics, the study said.​

​London, April 26 (IANS) Atmospheric carbon dioxide (CO2) concentration was the major driver behind the global climatic shifts that occurred in the "Eocene epoch" between 53 and 34 million years ago, says a new study.

The results support the view that elevated CO2 was responsible for the extreme warmth of the early Eocene and that CO2 decline was responsible for the subsequent cooling that ultimately led to the establishment of today’s polar ice sheets.

The researchers believe that the findings, published in the journal Nature, could help scientists better predict future climate change.

For the study, the research team developed new records of past CO2 levels by analysing ancient ocean sediments. 

"We cannot directly measure CO2 concentrations from that long ago,” said study lead author Eleni Anagnostou, postdoctoral researcher at University of Southampton in Britain.

"Instead we must rely on indirect ‘proxies’ present in the geological record. In this study, we used the chemical composition of marine fossils preserved in sediments to reconstruct ancient CO2 levels,” Anagnostou noted.

Applying pioneering geochemical techniques - developed at the University of Southampton over the past five years - the team used isotopes of the element boron in the shells as a proxy for pH (a measure of acidity), and used that to determine the atmospheric CO2 levels.

They found that between the early Eocene and the late Eocene, CO2 levels approximately halved. 

Using our current understanding of the relationship between sea surface temperature and CO2 at different latitudes, they also demonstrated that the changes in CO2 concentration can explain the majority of the cooling that occurred.

This research can also be used to gain a better understanding of how the Earth will respond to increasing levels of CO2 in the future, the scientists said.​

New York, April 23 (IANS) Contrary to popular perception, smoking cessation drugs do not increase the risk of serious neuropsychiatric adverse effects such as depression, hostility or suicidal behaviour, says a large study.

Researchers have found that compared to the nicotine patch and a placebo the smoking cessation drugs varenicline and bupropion do not show a significant increase in neuropsychiatric adverse events. 

"There are one billion smokers in the world and nearly six million smoking-related deaths each year, but there are only three approved medication treatments for quitting: nicotine replacement therapies like the patch and the two non-nicotine medications, bupropion and varenicline," said first author of the study Robert Anthenelli, professor at the University of California San Diego School of Medicine.

The study, published online in the journal The Lancet, is important because it prospectively examined the neuropsychiatric safety risks and quit-enhancing potential of the three medication classes versus placebo in a rigorous, adequately-sized, randomised controlled trial, Anthenelli said.

The researchers sought to directly assess the safety and efficacy of varenicline and bupropion compared to the nicotine patch and to a placebo in smokers with and without psychiatric disorders. 

The study involved examination of more than 8,000 smokers seeking to quit in 16 countries over a period from November 2011 to January 2015. 

Trial participants, investigators and research personnel were blinded to who received which treatment.

In terms of safety, approximately two percent of non-psychiatric participants reported moderate or severe adverse neuropsychiatric events for any of the treatments.

In the cohort of participants with psychiatric disorders, moderate and severe adverse neuropsychiatric events were slightly higher across the board: 6.5 percent for varenicline, 6.7 percent for bupropion, 5.3 percent for the nicotine patch and 4.9 percent for placebo.

Anthenelli said the risk difference in the incidence of serious neuropsychiatric adverse events for varenicline and bupropion was not significantly higher than placebo - but that psychiatric patients trying to stop smoking are likely to have more confounding factors in treatment and appear to have a harder time quitting.

​New York, April 24 (IANS) Researchers have found that adding salt to metal oxides increases their energy storage capacity by increasing their surface area.

The team, including researchers from Drexel University in the US, Huazhong University of Science and Technology (HUST) and Tsinghua University in China, published the results in the journal Nature Communications.

The results show that using salt crystals as a template to grow thin sheets of conductive metal oxides make the materials turn out larger and more chemically pure -- which makes them better suited for gathering ions and storing energy.

"The challenge of producing a metal oxide that reaches theoretical performance values is that the methods for making it inherently limit its size and often foul its chemical purity, which makes it fall short of predicted energy storage performance," said Jun Zhou, an author of the research, said.

"Our research reveals a way to grow stable oxide sheets with less fouling that are on the order of several hundreds of times larger than the ones that are currently being fabricated," Zhou, who is also a professor at HUST's Wuhan National Laboratory for Optoelectronics, added.

In theory, the best materials for the job should be thin sheets of metal oxides, because their chemical structure and high surface area makes it easy for ions to attach -- which is how energy storage occurs.

But the metal oxide sheets that have been fabricated in labs thus far have fallen well short of their theoretical capabilities, the paper said.

"This method of synthesis, called 'templating' -- where we use a sacrificial material as a substrate for growing a crystal -- is used to create a certain shape or structure," said Yury Gogotsi, another author of the paper.

"The trick in this work is that the crystal structure of salt must match the crystal structure of the oxide, otherwise it will form an amorphous film of oxide rather than a thing, strong and stable nanocrystal. This is the key finding of our research -- it means that different salts must be used to produce different oxides," Gogotsi added.​

New York, April 24 (IANS) Despite having extremely underdeveloped muscles and wings, young birds may acquire a mature flight stroke early in life by initially relying more on their legs and wings for power, finds a new study.

Adult birds have large wings and robust interlocking forelimb skeletons that may help meet the demands of flight.

But, the juvenile birds have small "protowings" or "mini wings" and flexible joints that lack many of the hallmarks of advanced flight.

Despite these limitations, young birds can flap their wings as they run up slopes and even briefly fly, challenging longstanding ideas about the origin of flight and flight development, the researchers said.

The team used X-ray analysis to visualise skeletal movement as birds like Chukar partridges, Alectoris flapped their wings while trying to climb steep slopes.

The findings showed that when flap-running at similar levels of effort, juvenile and adult birds showed similar patterns of joint movement.

Despite their undeveloped anatomy, young birds appeared to produce all of the elements of the avian flight stroke and modify their wing stroke for different behaviours, much like adults.

The force generated by flapping may push the birds forward as well as upward, improving traction as they climb.

Understanding flapping behaviour in young birds may provide insight into the possible use of mini-wings by extinct theropod dinosaurs, before flight evolved, the researchers suggested in the study published in the journal PLOS ONE.

"Baby birds anatomically look a lot like some of the dinosaur fossils that we see," said Ashley Heers from American Museum of Natural History in US.

"And so, by studying baby birds and looking at how they actually use these dinosaur-like anatomies, we can get a better sense of how these long-extinct animals might have been using their wings," Heers concluded.​

New York, April 24 (IANS) Fructose, a sugar common in the western diet, can damage hundreds of brain genes in a way that could lead to a range of diseases -- from diabetes to cardiovascular disease, and from Alzheimer's to attention deficit hyperactivity disorder -- warns a new study.

However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid (DHA) seems to reverse the harmful changes produced by fructose.

"DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable," said Xia Yang, assistant professor at the University of California - Los Angeles (UCLA).

DHA enhances learning and memory. It is abundant in wild salmon (but not in farmed salmon) and, to a lesser extent, in other fish and fish oil, as well as walnuts, flaxseed, and fruits and vegetables, co-senior author Fernando Gomez-Pinilla, an UCLA professor, pointed out.

The research was published online in the journal EBioMedicine.

To test the effects of fructose and DHA, the researchers trained rats to escape from a maze, and then randomly divided the animals into three groups.

For the next six weeks, one group of rats drank water with an amount of fructose that would be roughly equivalent to a person drinking a liter of soda per day.

The second group was given fructose water and a diet rich in DHA. The third received water without fructose and no DHA.

After the six weeks, the rats were put through the maze again. The animals that had been given only the fructose navigated the maze about half as fast than the rats that drank only water -- indicating that the fructose diet had impaired their memory.

The rats that had been given fructose and DHA, however, showed very similar results to those that only drank water -- which strongly suggests that the DHA eliminated fructose's harmful effects.

Other tests on the rats revealed more major differences: The rats receiving a high-fructose diet had much higher blood glucose, triglycerides and insulin levels than the other two groups.

Those results are significant because in humans, elevated glucose, triglycerides and insulin are linked to obesity, diabetes and many other diseases.

The research team sequenced more than 20,000 genes in the rats' brains, and identified more than 900 genes that were altered by the fructose.

The altered genes they identified, the vast majority of which are comparable to genes in humans, are among those that interact to regulate metabolism, cell communication and inflammation.

Among the conditions that can be caused by alterations to those genes are Parkinson's disease, depression, bipolar disorder, and other brain diseases, Yang said.​

​London, April 24 (IANS) Far from making you smarter, electrical stimulation of the brain's cells while solving challenging tasks can lead to mental overload, warn researchers.

The researchers wanted to test whether a treatment that sends a very weak electrical current through the skull to the outer layers of the brain, so-called transcranial direct current stimulation (tDCS), can actually make us smarter.

The tasks for the participants were divided into three levels -- simple, medium and difficult.

The researchers found no effect of stimulation when participants performed the simple and medium tasks, yet they found a large negative effect on the most difficult tasks.

"tDCS had a disruptive effect only on the most difficult tasks that demanded a lot of concentration," said one of the lead researchers, James Roe from the University of Oslo in Norway.

"We saw that participants experienced severe problems concentrating when the task was most difficult and the brain was being stimulated," Roe noted.

"It was as though tDCS had completely overloaded a brain region crucial to performing the task, as though it crashed it," Roe explained in a paper published in the journal Neuropsychologia.

In recent times neuroscientists have been showing increased interest for tDCS. Many claim that the device can, among other things, help improve memory, increase self-control and make us more creative.

tDCS is already implemented in the rehabilitation of a range of psychiatric and neurological conditions, such as depression, stroke, Alzheimer's disease, fibromyalgia and tinnitus.

While the researchers acknowledged that tDCS can indeed have a positive impact, they said the study shed light on the effects of tDCS when we solve tasks of varying difficulty.​