Knowledge Update

London, Nov 26 (IANS) Researchers have engineered cells with a "built-in genetic circuit" that produces a molecule that impairs the ability of cancer cells to survive and grow in their low oxygen environment.

The genetic circuit produces the machinery necessary for the production of a compound that inhibits a protein which has a significant and critical role in the growth and survival of tumours. 

This results in the cancer cells being unable to survive in the low oxygen, low nutrient tumour micro-environment.

"In a wider sense, we have given these engineered cells the ability to fight back -- to stop a key protein from functioning in cancer cells," said lead researcher Ali Tavassoli, Professor at the University of Southampton in Britain.

"This opens up the possibility for the production and use of sentinel circuits, which produce other bioactive compounds in response to environmental or cellular changes, to target a range of diseases including cancer," Tavassoli said.

As tumours develop and grow, they rapidly outstrip the supply of oxygen delivered by existing blood vessels. This results in cancer cells needing to adapt to a low oxygen environment.

To enable them to survive, adapt and grow in the low oxygen or 'hypoxic' environment, tumours contain increased levels of a protein called Hypoxia-inducible factor 1 (HIF-1). 

This protein senses reduced oxygen levels and triggers many changes in cellular function, including a changed metabolism and sending signals for the formation of new blood vessels. 

It is thought that tumours primarily hijack the function of this protein (HIF-1) to survive and grow.

"In an effort to better understand the role of HIF-1 in cancer, and to demonstrate the potential for inhibiting this protein in cancer therapy, we engineered a human cell line with an additional genetic circuit that produces the HIF-1 inhibiting molecule when placed in a hypoxic environment," Tavassoli explained. 

"We've been able to show that the engineered cells produce the HIF-1 inhibitor, and this molecule goes on to inhibit HIF-1 function in cells, limiting the ability of these cells to survive and grow in a nutrient-limited environment as expected," Tavassoli noted.

The genetic circuit was incorporated onto the chromosome of a human cell line, which encodes the protein machinery required for the production of their cyclic peptide HIF-1 inhibitor.

The research, published in the journal ACS Synthetic Biology, demonstrates the possibility of adding new machinery to human cells to enable them to make therapeutic agents in response to disease signals.

Washington, Nov 25 (IANS) Researchers have found a novel way to make fuel cells more energy efficient and increase their power output by fine-tuning metal catalysts at the atomic scale.

A nano size squeeze can significantly boost the performance of platinum catalysts that help generate energy in fuel cells, according to the new study by scientists at Stanford University.

"Our tuning technique could make fuel cells more energy efficient and increase their power output," said study co-author Yi Cui, Professor at Stanford and SLAC National Accelerator Laboratory in California. 

"It could also improve the hydrogen-generation efficiency of water splitters and enhance the production of other fuels and chemicals," Cui noted.

The team bonded a platinum catalyst to a thin material that expands and contracts as electrons move in and out, and found that squeezing the platinum a fraction of a nanometre nearly doubled its catalytic activity. 

"In this study, we present a new way to fine-tune metal catalysts at the atomic scale," said lead author Haotian Wang, a former graduate student at Stanford now at Harvard University.

"We found that ordinary battery materials can be used to control the activity of platinum and possibly for many other metal catalysts," Wang noted.

The new technique described in the journal Science can be applied to a wide range of clean technologies, including fuel cells that use platinum catalysts to generate energy, and platinum electrolysers that split water into oxygen and hydrogen fuel, Wang said.

Catalysts are used to make chemical reactions go faster while consuming less energy. The performance of a metal catalyst depends on its electronic structure -- that is, how the electrons orbiting individual atoms are arranged.

The team introduced a novel way to compress or separate the atoms by 5 percent, a mere 0.01 nanometer.

"That might not seem like much, but it's really a lot," Cui said.

"We found that compression makes platinum much more active," Wang added. 

"We observed a 90 per cent enhancement in the ability of platinum to reduce oxygen in water. This could improve the efficiency of hydrogen fuel cells," Wang said.

New York, Nov 25 (IANS) Various brain regions that once synchronised their activity during memory tasks become smaller and lose cohesion as people age, says a study.

In the study, researchers from Princeton University in New Jersey, US, described a novel method to characterise and compare the brain dynamics of individual people.

The research showed that regardless of whether we were using memory, directing attention, or resting, the number of synchronous groups of connections within our brain was consistent. 

However, between different individuals, these numbers vary dramatically.

In fact, during memory specific actions, variations between people are closely linked to age.

Younger participants have only a few large synchronous groups that link nearly the entire brain in coordinated activity, while older participants show progressively more but smaller groups of connections.

In the older group this indicates loss of cohesive brain activity -- even in the absence of memory impairment, the authors noted.

"This method elegantly captures important differences between individual brains, which are often complex and difficult to describe," said Elizabeth Davison from Princeton University. 

"The resulting tools show promise for understanding how different brain characteristics are related to behaviour, health, and disease," Davison added.

For the study, the researchers used functional magnetic resonance imaging (fMRI) to record healthy people's brain activity during memory tasks, attention tasks, and at rest. 

For each person, the fMRI data was recast as a network composed of brain regions and the connections between them. 

The scientists then use this network to measure how closely different groups of connections changed together over time.

The study was published in the journal PLOS Computational Biology.

London, Nov 25 (IANS) Researchers have found that depression in young people is often followed by arthritis and diseases of the digestive system, while skin diseases are common after anxiety disorders.

The findings suggest that mental disorders are antecedent risk factors of certain physical diseases in early life, but also vice versa, according to the researchers.

"Our results expand the relevance of mental disorders beyond mental to physical health care, and vice versa, supporting the concept of a more integrated mental-physical health care approach, and open new starting points for early disease prevention and better treatments, with relevance for various medical disciplines," the study said.

The research group led by Marion Tegethoff in collaboration with Professor Gunther Meinlschmidt from the University of Basel in Switzerland examined the temporal pattern and relationship between physical diseases and mental disorders in children and young people. 

They analysed data from a representative sample of 6,483 teenagers from the US aged between 13 and 18.

The researchers noted that some physical diseases tend to occur more frequently in children and adolescents if they have previously suffered from certain mental disorders. 

Likewise, certain mental disorders tend to occur more frequently after the onset of particular physical diseases.

Affective disorders such as depression were frequently followed by arthritis and diseases of the digestive system, while the same relationship existed between anxiety disorders and skin diseases, showed the study published in the journal PLOS ONE.

Anxiety disorders were more common if the person had already suffered from heart disease. A close association was also established for the first time between epileptic disorders and subsequent eating disorders.

The results offer important insights into the causal relationship between mental disorders and physical diseases.

​New York, Nov 25 (IANS) Taking a step further in identifying a possible therapy for the Zika infection, researchers have discovered the mechanism by which a human antibody previously identified to react with the Dengue virus, prevents Zika infection at a cellular level.

Previously, the antibody C10 was identified as one of the most potent antibodies able to neutralise Zika infection. The new study, published in the journal Nature Communications, determines how C10 prevents the infection.

"By defining the structural basis for neutralization, these studies provide further support for the idea that this antibody will protect against Zika infection, potentially leading to a new therapy to treat this dreaded disease," said Ralph Baric, Professor at University of North Carolina.

To infect a cell, virus particles usually undergo two main steps, docking and fusion, which are also common targets for disruption when developing viral therapeutics. 

During docking, the virus particle identifies specific sites on the cell and binds to them. With Zika infection, docking then initiates the cell to take the virus in via an endosome -- a separate compartment within the cell body. 

Proteins within the virus coat undergo structural changes to fuse with the membrane of the endosome, thereby releasing the virus genome into the cell, and completing the fusion step of infection.

Using a method called cryoelectron microscopy, which allows for the visualisation of extremely small particles and their interactions, the team visualised C10 interacting with the Zika virus under different pHs (potential of hydrogen, a scale of acidity), so as to mimic the different environments both the antibody and virus will find themselves in throughout infection. 

They showed that C10 binds to the main protein that makes up the Zika virus coat, regardless of pH, and locks these proteins into place, preventing the structural changes required for the fusion step of infection. 

Without fusion of the virus to the endosome, viral DNA is prevented from entering the cell, and infection is thwarted.

"Hopefully, these results will further accelerate the development of C10 as a Zika therapy to combat its effects of microcephaly (a birth defect) and Guillain-Barre (paralysis) syndrome," one of the researchers Lok Shee-Mei from Duke-National University of Singapore Medical School in Singapore.

​New York, Nov 24 (IANS) Researchers have developed a first-of-its-kind soft, flexible microfluidic device that easily adheres to the skin and connects wirelessly with a smartphone to measure the wearer's sweat to show how his or her body is responding to exercise.

Sweat is a rich, chemical broth containing a number of important chemical compounds with physiological health information, the researchers said.

The low-cost device, which is a little larger than a quarter and nearly the same thickness, connects wirelessly with a smartphone to analyse key biomarkers to help a person to find whether he/she needs to drink more water or energy drink to boost the electrolyte levels, or if something is medically going wrong in his/her body.

"The intimate skin interface created by this wearable, skin-like microfluidic system enables new measurement capabilities not possible with the kinds of absorbent pads and sponges currently used in sweat collection," said John A. Rogers, Professor at the Northwestern University, US.

For the study, published in the journal Science Translational Medicine, the team tested the device on two groups of cyclists. 

The device, which is designed for one-time use for a few hours, was placed directly on the skin of the forearm or back of the athletes.

It showed accurate accounts of the acidity of sweat and concentrations of glucose, chloride and lactate and could even detect the presence of a biomarker for cystic fibrosis.

To get the data, individuals had to use a smartphone to capture the photo of the device. An app then analyses that photo to display the relevant information.

"The sweat analysis platform we developed will allow people to monitor their health on the spot without the need for a blood sampling and with integrated electronics that do not require a battery but still enable wireless connection to a smartphone," said Yonggang Huang, Professor at the Northwestern University, US.

In the future, it may be more broadly used for disease diagnosis, the researchers added.

Melbourne, Nov 25 (IANS) An Australian Nobel Prize-winning scientist is developing a drug to counter allergies and asthma, a statement said on Friday.

Still in its initial stage the the drug can be taken as tablets, capsules, liquids or powder, Xinhua news reported. 

Barry Marshall, a microbiology professor from University of Western Australia, who won the Nobel Prize in Physiology in 2005 for stomach ulcer research, is working on the new drug.

The medication, named Immbalance, aims to suppress an overactive immune system.

"This actually arose from work we were doing on helicobacter, the stomach bug, for which Robin Warren and I won the Nobel Prize a few years ago," Marshall said on Friday.

"We've discovered the way it survives in your body is by suppressing the immune system so you can't get rid of it.

"I can't guarantee that it's going to cure allergy sufferers... we think this kind of thing will bring people who are hyper reactive... down into the normal range."

Marshall, who spent the last seven years developing the drug, said that it can be formulated as tablets, capsules, liquids or powder.

"Children could spread the powder on their cereal or put it in a drink and over the course of a few months could suppress their allergic response," he said in a UWA media release.

"We think it's going to be 100 percent safe. It won't remove your immune system; it will just take the edge off."

Washington, Nov 23 (IANS) Using a 8.2-meter telescope on the summit of Mauna Kea in Hawaii, an international team of researchers has found what could be the faintest dwarf satellite galaxy of our Milky Way.

Called Virgo I, the new dwarf satellite galaxy lies in the direction of the constellation Virgo at a distance of 280,000 light years from our Sun, Xinhua news agency reported.

It has an absolute luminosity of -0.8 in the optical waveband and such a remote galaxy with faint brightness has not been identified in previous sky surveys.

Its discovery suggested the presence of a large number of yet-undetected dwarf satellites in the halo of the Milky Way, according to the study published this week in The Astrophysical Journal.

"This discovery implies hundreds of faint dwarf satellites waiting to be discovered in the halo of the Milky Way," study leader Masashi Chiba, a professor from the Tohoku University in Japan, said in a statement.

"How many satellites are indeed there and what properties they have, will give us an important clue of understanding how the Milky Way formed and how dark matter contributed to it."

So far, some 50 satellite galaxies to the Milky Way have been identified.

​London, Nov 24 (IANS) With the onset of Christmas season, millions of parents will lie to their children about the existence of Santa Claus or Christmas Father. A new study has suggested that this lie may damage their bond.

The study, published in Lancet Psychiatry, showed that the children's trust in their parents may be undermined by the Santa lie.

"The morality of making children believe in such myths has to be questioned. All children will eventually find out they've been consistently lied to for years, and this might make them wonder what other lies they've been told," asked Christopher Boyle, Professor at the University of Exeter in Britain.

But, according to the authors, the Christmas father fantasy may not be purely for the children.

Parents may not be motivated by purely creating magic for their children, but by a desire to return to the joy of childhood themselves.

For adults, it's a chance to go back to a time when they believed in magic.

"Many people may yearn for a time when imagination was accepted and encouraged, which may not be the case in adult life," Boyle said.

"The persistence of fandom in stories like Harry Potter, Star Wars and Doctor Who well into adulthood demonstrates this desire to briefly re-enter childhood," added Kathy McKay from the University of New England, Australia. 

However, the study contended that lying to children may sometimes be right.

"An adult comforting a child and telling them that their recently deceased pet will go to a special place (animal heaven) is arguably nicer than telling graphic truths about its imminent re-entry into the carbon cycle," Boyle observed.

​New York, Nov 23 (IANS) In the largest study of its kind, researchers have discovered rare genetic variations linked to schizophrenia, a severe mental disorder that often includes psychotic experiences, such as delusions or hearing voices that are not there.

The Psychiatric Genomics Consortium, an international team led by Jonathan Sebat from the University of California San Diego School of Medicine in the US analysed the genomes of more than 41,000 people.

Their study, published in the journal Nature Genetics, revealed several regions of the genome where mutations increase schizophrenia risk between four- and 60-fold.

These mutations, known as copy number variants, are deletions or duplications of the DNA sequence. 

A copy number variant may affect dozens of genes, or it can disrupt or duplicate a single gene. 

"This type of variation can cause significant alterations to the genome and lead to psychiatric disorders," said Sebat.

Analysing the genomes of 21,094 people with schizophrenia and 20,227 people without schizophrenia, the team of more than 260 researchers found eight locations in the genome with copy number variants associated with schizophrenia risk. 

The researchers also found that these copy number variants occurred more frequently in genes involved in the function of synapses, the connections between brain cells that transmit chemical messages.

"We're confident that applying this same approach to a lot of new data will help us discover additional genomic variations and identify specific genes that play a role in schizophrenia and other psychiatric conditions," Sebat said.