Knowledge Update

London, Sep 18 (IANS) Removing one carotid body from some patients with high blood pressure can provide immediate and sustained fall in blood pressure, finds a new study.

Carotid bodies, a small cluster of chemoreceptors and supporting cells located near the fork (bifurcation) of the carotid artery that feed the brain with blood, appear to be a cause of high blood pressure.

"The falls in blood pressure are impressive -- more than pharmacological medication -- and demonstrate the potential for targeting the carotid body to treat hypertension," said Angus Nightingale, researcher at the University of Bristol, England.

The carotid bodies detect the levels of oxygen in blood and when this falls they raise the alarm of a potential emergency by signalling to the brain to increase breathing and blood pressure.

"Treating the carotid body is a novel approach and a potential game changer as we believe we are reducing one of the main causes for hypertension in many patients. High blood pressure treatment typically tackles the symptoms targeting the end organs such as the heart, kidneys and blood vessels, and not the causes," said Julian Paton, researcher at the University of Bristol, England.

The clinical trial demonstrated that the carotid bodies in patients who responded to resection had raised carotid body activity. These patients breathed more at rest and produced exaggerated breathing responses when the oxygen level in their blood was lowered.

"Although this surgical approach to controlling high blood pressure was successful, we don't think this will be the solution in the long term. We now need to find a drug that dampens down an overactive carotid body and resets the blood pressure thermostat to a normal level," Nightingale added.

The research study was published recently in the Journal of American College of Cardiology: Basic to Translational Science.

​London, Sep 18 (IANS) The way people walk can give significant insights into their levels of aggression, a study has found.

The study revealed that the exaggerated movement of both the upper and lower body indicated aggression.

"When walking, the body naturally rotates a little, as an individual steps forward with their left foot, the left side of the pelvis will move forward with the leg, the left shoulder will move back and the right shoulder forward to maintain balance. An aggressive walk is one where this rotation is exaggerated," said lead researcher Liam Satchell from the University of Portsmouth in Britian.

People are generally aware that there is a relationship between swagger and psychology.

However, the research provides empirical evidence to confirm that personality is indeed manifested in the way we walk, the researchers said.

Further, identifying the potential relationship between an individual's biological motion and their intention to engage in aggression could be used to help prevent crime, Satchell noted.

"If CCTV observers could be trained to recognise the aggressive walk demonstrated in this research, their ability to recognise impending crimes could be improved further," he said.

For the study, the team assessed the personalities of 29 participants, before using motion capture technology to record them walking on a treadmill at their natural speed.

The researchers also used a standard personality test called the 'big five' to assess personality traits including openness, conscientiousness, extraversion, agreeableness and neuroticism.

Using motion capture technology, which records the actions of humans and uses the information to bring to life digital character models in 3D computer animation, the researchers analysed thorax and pelvis movements, as well as speed of gait.

New York, Sep 18 (IANS) A single dose of a bioengineered gel, developed by US researchers, could deliver a full course of antibiotic therapy for a common childhood ear infection, a preclinical study has found.

Middle-ear infection, or otitis media, is an ear infection that is usually caused by bacteria or viruses.

Common symptoms include ear pain and fever and in some cases, it may also cause drainage of fluid from the ear or hearing loss. Although most ear infections go away on their own, some require antibiotics.

As high doses of oral antibiotics are needed to get to the ear, side effects like diarrhea, rashes and oral thrush are common.

"With oral antibiotics, you have to treat the entire body repeatedly just to get to the middle ear," said Rong Yang, Ph.D., a chemical engineer at Boston Children's Hospital in Massachusetts, US.

However, "with the gel, a paediatrician can administer the entire antibiotic course all at once, and only where it's needed," Yang said.

Squirted into the ear canal, the gel quickly hardens and stays in place, gradually dispensing antibiotics across the eardrum into the middle ear.

"Our technology gets things across the eardrum that don't usually get across in sufficient quantity to be therapeutic," added Daniel Kohane from Boston Children's Hospital.

Previously, the eardrum (also called the tympanic membrane) was an impenetrable barrier, but the bioengineered gel gets drugs past it with the help of chemical permeation enhancers (CPEs).

The CPEs insert themselves into the membrane, opening up molecular pores that allow the antibiotics to seep through to the eardrum's outermost layer.

"Transtympanic delivery of antibiotics to the middle ear has the potential to enable children to benefit from the rapid antibacterial activity of antimicrobial agents without systemic exposure and could reduce emergence of resistant microbes," noted Stephen Pelton, paediatrician at Boston Medical Center.

The findings, published by the journal Science Translational Medicine, have led to better, easier and potentially safer treatment for middle ear infections, the researchers concluded.

London, Sep 18 (IANS) Computer-assisted smart power grids help reduce power generation shortfall, and result in improved delivery and more efficient billing, a study in Britain has concluded.

"A smart grid is a complex modern electricity system which utilises sensors, monitoring, communications and automation, to improve the electricity system," the researchers wrote in the study. 

"Smart grids fundamentally change the way in which we generate, distribute and monitor our electricity. They dramatically improve the efficiency, flexibility and reliability of the existing electricity infrastructure," the researchers said.

Carl Chalmers, Michael Mackay and Aine MacDermott of Liverpool John Moores University, in England, explained in their research, published in the International Journal of Smart Grid and Green Communications, the advantages of a smart grid over the traditional energy grid.

They said smart grids use a vast interconnected infrastructure that allows two-way communication and automation throughout the entire grid -- from generator to consumer and back -- striking out the possibility of a malicious manipulation into the metering system for the sake of sabotage, criminal or online military/terrorist action.

The researchers, however, suggested that after knowing the possible worst-case scenario with regard to the smart grid and smart meters, countries must put in place security measures to protect the infrastructure.

The research team noted that critical infrastructures present a tempting target for terrorists, military strikes and hackers wanting to cause disruption, steal information or incapacitate a country remotely.

New York, Sep 18 (IANS) Pathogens in the intestinal tract can manipulate mammalian cells to get the oxygen they need and thereby cause harm to the intestinal lining, a study has found.

The study also offers a new insight into developing strategies targeting the metabolism of the intestinal lining to prevent the expansion of harmful bacteria in the gut, a situation that is exacerbated by the overuse of antibiotics.

"The finding is important because it explains how some enteric pathogens can manipulate mammalian cells to get the oxygen they need to breathe," said Andreas Baumler, Professor at the University of California Davis School of Medicine in the study published in the journal Science.

A healthy large intestine is mostly free of oxygen and the beneficial microbes residing there thrive in this anaerobic environment. In contrast, enteric pathogens, such as Escherichia coli, in humans need oxygen to survive.

Baumler's team discovered how these pathogens change the gut environment to favour their own growth.

Enteric pathogens deploy virulence factors that damage the intestinal lining and cause diarrhea. To repair the damage, the body accelerates the division of epithelial cells that form the intestinal lining, which brings immature cells to the mucosal surface. 

These new cells contain more oxygen and wind up increasing oxygen levels in the large bowel, creating an environment that allows gut pathogens like E. coli to outcompete the anaerobic-loving resident microbes.

"The rise of antibiotic-resistant strains of bacteria has become a major public health threat worldwide. As more bacterial strains do not respond to the drugs designed to kill them, the advances made in treating infectious diseases over the last 50 years are in jeopardy," Baumler added.

New York, Sep 18 (IANS) A new study has found evidence that health becomes endangered when ageing cells lose control of rogue elements of DNA called transposons.

Research has shown that a low-calorie diet, a key intervention already known to increase lifespan, dramatically delays the onset of increased transposon activity.

The new study, published in the journal Proceedings of the National Academy of Sciences, strengthens the links that have led scientists to propose the "transposon theory of ageing".

"In this report, the big step forward is towards the possibility of a true causal relationship," said senior author of the study Stephen Helfand, Professor at the Brown University in Providence, at Rhode Island, in the US.

Transposons are rogue elements of DNA that break free in ageing cells and rewrite themselves elsewhere in the genome, potentially creating lifespan-shortening chaos in the genetic makeups of tissues.

As cells get older, prior studies have shown, tightly wound heterochromatin wrapping that typically imprisons transposons becomes looser, allowing them to slip out of their positions in chromosomes and move to new ones, disrupting normal cell function.

Meanwhile, scientists have shown that potentially related interventions, such as restricting calories or manipulating certain genes, can demonstrably lengthen lifespans in laboratory animals.

The new results come from several experiments that are thorough and direct in connecting the dots among weakening heterochromatin, increased transposon expression, ageing and lifespan.

In one set of experiments, the team visually caught transposable elements in the act of jumping around in fruit flies as they aged.

They showed that an anti-HIV drug called 3TC, which inhibits activation of transposons and their movement into new positions in the genome, can restore some lifespan to flies that have a mutation that disables a gene called Dicer-2 which suppresses transposons.

​New York, Sep 18 (IANS) A team of researchers has created three-dimensional lung "organoids" -- laboratory-grown lung-like tissue -- to study diseases, including idiopathic pulmonary fibrosis.

The 3D dimensional drug has been created by coating tiny gel beads with lung-derived stem cells and allowing them to self-assemble into the shape of air sacs found in human lungs.

"While we haven't built a fully functional lung, we have been able to take lung cells and place them in the correct geometrical spacing and pattern to mimic a human lung," said Brigitte Gomperts, Associate Professor, at the University of California, at Los Angeles in the US.

Idiopathic pulmonary fibrosis is a chronic lung disease characterised by scarring of the lungs. The scarring makes the lungs thick and stiff, which over time results in progressively worsening shortness of breath and lack of oxygen to the brain and vital organs. 

To study the effect of genetic mutations or drugs on lung cells, researchers have previously relied on two-dimensional cultures of the cells. But when they take cells from people with idiopathic pulmonary fibrosis and grow them on these flat cultures, the cells appear healthy.

Gomperts and her colleagues, in the study published in the journal Stem Cells Translational Medicine, started with stem cells created using cells from adult lungs. They used those cells to coat sticky hydrogel beads and then they partitioned these beads into small wells, each only seven millimetres across. 

Inside each well, the lung cells grew around the beads, which linked them and formed an evenly distributed three-dimensional pattern. To show that these tiny organoids mimicked the structure of actual lungs, the researchers compared the lab-grown tissues with real sections of human lung.

"The technique is very simple. We can make thousands of reproducible pieces of tissue that resemble lung and contain patient-specific cells," said Dan Wilkinson, researcher at the University of California, Los Angeles.

Moreover, when the researchers added certain molecular factors to the 3D cultures, the lungs developed scars similar to those seen in the lungs of people who have idiopathic pulmonary fibrosis -- something that could not be accomplished using two-dimensional cultures of these cells.

London, Sep 19 (IANS) Individuals suffering from bipolar disorder or depression treated with a hormone best known to boost performance in sportspersons may also improve their cognitive functioning, a study has found.

The hormone erythropoietin (EPO), mostly produced by the kidney, is essential for the production of red blood cells. 

EPO gives the blood a greater capacity to carry oxygen, and is thus used as a performance-enhancing drug by the sportspersons, the study said. 

The findings showed that EPO had beneficial effects on patients' verbal memory, attention span as well as planning ability. 

The EPO-treated patients showed 11 per cent improvement while placebo treated patients improved only by 2 per cent. 

"This effect of EPO on cognition was maintained six-weeks after patients had completed their treatment," said lead researcher Kamilla Miskowiak from University of Copenhagen in Denmark. 

Further, the patients who performed poorly in neuropsychological tests showed remarkably greater cognitive benefits when given EPO. 

"This means that we may be able to target patients for EPO treatment and perhaps other future cognition treatments, based on how they do on neuropsychological tests," Miskowiak added. 

EPO based drugs are safe if patients' red blood cell levels are controlled regularly. 

However, the EPO may not be beneficial for people who smoke or who previously had blood clots or the have high risk of blood clots, the researchers said. 

"EPO may not be ready to be rolled out as a treatment just yet and may not be for everyone," Miskowiak noted.

Around 350 million people suffer from depression, with a further 60 million suffering from bipolar disorder, but the drugs normally used to treat depression and bipolar disorders don't have any major effect on cognition, according to recent reports from the World Health Organisation (WHO).

Currently there is no available effective treatment to target cognitive problems in these patients, the report stated.

"The results of this study, albeit preliminary, gives hope to people suffering from mood disorders and associated neurocognitive symptoms," said Eduard Vieta, Professor at the University of Barcelona Hospital Clinic, in Spain in a comment.

For the study, the team conducted two randomised controlled trials. They assessed cognitive function in 79 patients suffering from depression or bipolar disorder.

Out of these, 40 patients were assigned on EPO for 9-weeks and the remaining 39 were given a placebo. 

They found that EPO had beneficial effects on patients' completion of a range of cognitive tests, including tests on verbal memory, attention span, and planning ability.

Tests showed that this improvement was maintained for at least 6-weeks after treatment finished (the longest follow-up time in the trials).

The results were presented at the European College of Neuropsychopharmacology (ECNP)conference in Vienna, recently.

London, Sep 19 (IANS) Have you ever wondered why we sometimes 'freeze' when we are frightened or under strong emotional stress? This may be because the response to anxiety may include not only the parts of the brain which deal with emotions, as has been long understood, but also movement control centres in the brain.

"This (study) is the first hard proof that strong emotions produce a response in brain areas concerned with movement," said lead researcher Laura Muzzarelli from Vita-Salute San Raffaele University in Milan, Italy.

The findings give us "a possible explanation for some motor inhibition associated with emotional stress", she added.

For the study, a group of Italian and Canadian researchers followed a selection of socially anxious and control group children from childhood to adolescence. 

The researchers tested 150 children who were between ages of eight to nine, for signs of social inhibition.

Some of these were shown to have early signs of social anxiety, and showed an increased tendency to withdraw from social situations. 

They also had more difficulty in recognising emotions, and particularly angry faces.

The anxious children, plus controls, were then followed into adolescence. At the ages of 14-15 they were tested again to see if signs of social anxiety had developed. 

The researchers also used functional MRI brain scans to test how the teenage brains responded to angry facial expressions.

"We found that when presented with an angry face the brain of socially anxious adolescents showed increased activity in the amygdala, which is the brain area concerned with emotions, memory and how we respond to threats," Muzzarelli said.

"Surprisingly, we also found this produced inhibition of some motor areas of the brain, the premotor cortex. This is an area which 'prepares the body for action', and for specific movements," she noted. 

The findings were presented at the ongoing European College of Neuropsychopharmacology (ECNP) conference in Vienna, Austria.

​Washington, Sep 16 (IANS) The 2016 Arctic sea ice cover tied with 2007 for the second lowest yearly minimum on record, according to a new report.

Arctic sea ice appeared to have reached its annual lowest extent on September 10, NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado at Boulder reported on Thursday.

At 4.14 million square kilometres, the 2016 Arctic sea ice minimum extent is effectively tied with 2007 for the second lowest yearly minimum in the satellite record. 

"The record makes it clear that the ice is not rebounding to where it used to be, even in the midst of the winter," said Claire Parkinson, main author of the study and a senior climate scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland

The lowest sea ice extent recorded was on September 17, 2012, when it fell to just 3.39 million square kilometres, CNN reported.

The sea ice cover of the Arctic ocean and surrounding seas helps regulate the planet's temperature, influences the circulation of the atmosphere and ocean, and impacts Arctic communities and ecosystems. 

Arctic sea ice shrinks every year during the spring and summer until it reaches its minimum yearly extent. 

Sea ice regrows during the frigid fall and winter months, when the sun is below the horizon in the Arctic.

This summer, the melt of Arctic sea ice surprised scientists by changing pace several times.

The melt season began with a record low yearly maximum extent in March and a rapid ice loss through May. 

But in June and July, low atmospheric pressures and cloudy skies slowed down the melt.

Then, after two large storms went across the Arctic basin in August, sea ice melt picked up speed through early September, the report said.

"It's pretty remarkable that this year's sea ice minimum extent ended up the second lowest, after how the melt progressed in June and July," Walt Meier, a sea ice scientist with NASA's Goddard Space Flight Center said.