Knowledge Update

​New York, April 27 (IANS) Old age brings with it many health problems including the loss of vision, hearing and taste, and a new study says that the ability to smell the food through the mouth decreases with age.

Human beings not only pick up aromas through the nose, but also through the mouth while chewing the food. Retronasal smell, which is smelling from behind the nose comes into play when food is chewed and volatile molecules are released in the process.

These then drift through the mouth to the back of the nose where the odour is detected.

But, unfortunately, for some, this ability decreases with age, said Tyler Flaherty from Oregon State University in the US.

This might be, among other reasons, because of the prolonged use of medication or physical and mental changes associated with older age, the researchers noted in the study published in the journal Chemosensory Perception. 

One's ability to pick up smells through the mouth could also be influenced by, for instance, the use of dentures.

The results revealed that many of the older participants found it difficult to pick out specific odours.

However, younger participants fared better when individual smells where presented to them in combination with other tastes.

"Generally, large individual differences in odour responsiveness become even greater when ageing is considered as a factor," Flaherty said.

The team studied how people experience odours via their mouths, and whether age or gender has an influence on it. 

They included 102 non-smoking healthy people between the ages of 18 and 72 years old participants in the study.

The researchers then rated how intensely they pick up on two tastes (sweet and salty) and four odours (strawberry, vanilla, chicken and soy sauce) put to them. 

Participants were also exposed to these in combinations that go well together, such as sweet and vanilla, or salty and chicken.

Significantly, only three percent of the participants had trouble picking up any traces of the sweet or salty tastes, whereas up to 23 percent of them found it difficult to detect some of the sampled odours.

​New York, April 28 (IANS) A single antibody infusion can protect monkeys against infection with an HIV-like virus for up to 23 weeks, researchers have found.

The findings suggest that using infusion of broadly neutralising antibodies (bNAbs) as a prevention strategy potentially could protect people at high risk for HIV transmission. 

The study, published in the journal Nature, was led by scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health, and The Rockefeller University in New York.

In the study, the researchers rectally exposed macaques to weekly low doses of simian human immunodeficiency virus (SHIV), which contains components of HIV and a related monkey virus. 

On average, it took three weeks for detectable levels of virus to appear in the blood of untreated animals.

To investigate whether bNAb infusion could offer long-term protection against SHIV infection, the scientists gave single infusions of one of three individual bNAbs against HIV to three groups of six macaques, then exposed the animals weekly to low doses of SHIV. 

In all cases, the bNAb infusions delayed the acquisition of SHIV, with the longest period of protection lasting 23 weeks. 

The researchers found that the duration of protection depended on the antibody's potency and half-life - a measure of the antibody's lifespan in the blood and tissues.

Enrollment for the first of two planned human clinical trials assessing one of three individual bNAbs infusions for preventing HIV infection has already begun, the study pointed out.​

London, April 27 (IANS) Researchers have found that tablet computers loaded with literacy applications could improve the reading preparedness of young children living in economically disadvantaged communities.

The results of first three trials of the study were presented recently at the Association for Computing Machinery's Learning at Scale conference in Britain.

In all three cases, study participants' performance on standardised tests of reading preparedness indicated that the tablet use was effective.

The trials examined a range of educational environments. One was set in a pair of rural Ethiopian villages with no schools and no written culture; one was set in a suburban South African school with a student-to-teacher ratio of 60 to one; and one was set in a rural US school with predominantly low-income students.

In the African deployments, students who used the tablets fared much better on the tests than those who did not, and in the US deployment, the students' scores improved dramatically after four months of using the tablets.

"The whole premise of our project is to harness the best science and innovation to bring education to the world's most underresourced children," said study first author Cynthia Breazeal, associate professor of media arts and sciences at Massachusetts Institute of Technology (MIT) in the US.

The experiments consisted of an inexpensive tablet computer using Google's Android operating system. 

The researchers also developed their own interface for the tablets, which grants users access only to approved educational apps. Across the three deployments, the tablets were issued to children ranging in age from four to 11.

"When we do these deployments, we purposely don't tell the kids how to use the tablets or instruct them about any of the content," Breazeal said. ​

​London, April 27 (IANS) Danish researchers have developed a novel genetic method that could lead to the development of safe and effective vaccines for controlling diseases such as cancer, asthma, and allergies.

"The major research breakthrough is that we have created a general and user-friendly platform for the development of a special type of effective and safe vaccines,” said one of the researchers Adam Sander from University of Copenhagen in Denmark.

"The highly effective method opens a new door for controlling diseases such as cancer, asthma, allergies and cardiovascular diseases by means of vaccines,” Sander pointed out.

The method was described in the Journal of Nanobiotechnology.

The idea behind the new technique is to mimic the structure of a virus. When you have made the virus structure, it is used as a platform onto which are glued harmless parts of the disease which you want to vaccinate against. 

This creates an overall virus-like structure, which constitutes an important danger signal for the body. The immune system would therefore produce antibodies against the disease -- a mechanism which has been difficult to activate by traditional vaccines.

The technology is also so effective that it can trick the immune system into attacking the body's own cells, which may be used in the treatment of a number of serious diseases, such as cancer, which are not caused by foreign organisms, the study said.

"Previously, it was a major problem to activate the immune system and get an adequate response. We have lacked the possibility to easily create a vaccine which mimics something that will trigger a natural response from the body, but the new virus-like platform now allows us to do so,” Susan Thrane from University of Copenhagen noted.

"In other words, we now have a unique technique that enables us to develop vaccines against diseases that we have so far been unable to fight," Thrane pointed out.

"It will be a game changer for low-income countries, which can now make vaccines targeted at widespread diseases such as tuberculosis and malaria. There is no doubt that the new results will have a significant impact on tomorrow's vaccines and public health," Ali Salanti, professor at University of Copenhagen, said.​

​New York, April 25 (IANS) Children exposed to chemicals used in liquid laundry detergent packets may have serious health effects such as breathing problems, heart problems, and even death, warns a study.

The study, published online in the journal Pediatrics, found that from January 2013 to December 2014 poison control centres in the US received 62,254 calls related to laundry and dishwasher detergent exposures among children younger than six years old.

Incidents related to laundry detergent packets saw the biggest rise -- increasing 17 percent over the two-year study period.

Poison control centres in the US received more than 30 calls a day about children who had been exposed to a laundry detergent packet, which is about one call every 45 minutes.

At least one child a day was admitted to the hospital due to a laundry detergent packet exposure.

In addition, the study also saw two child deaths which were associated with exposure to liquid laundry detergent packets.

"Many families don't realise how toxic these highly concentrated laundry detergent packets are," noted study co-author Marcel Casavant, chief of toxicology at Nationwide Children's Hospital in Ohio, US.

To curb incidents related to laundry detergent packets exposure, ASTM International -- a standards organisation that develops and publishes voluntary consensus technical standards for various products, published a voluntary standard safety specification for liquid laundry packets in 2015.

But, according to some experts, the report is ineffective or not substantial enough to reduce unintentional exposures to the contents of laundry detergent packets.

"This voluntary standard is a good first step, but it needs to be strengthened," one of the researchers Gary Smith, director of the Center for Injury Research and Policy at Nationwide Children's Hospital in Ohio said.

"Unless this unacceptably high number of exposures declines dramatically, manufacturers need to continue to find ways to make this product and it's packaging safer for children," Smith suggested.

Experts recommend that families with children younger than six-years old should use traditional detergent, which is much less toxic than laundry detergent packets, as well as store all laundry detergents up, away, and out of sight of the kids.

"Use traditional laundry detergent when you have young kids in your home. It isn't worth the risk when there is a safer and effective alternative available," Casavant pointed out.​

​Geneva, April 25 (IANS) As many as 21 countries, including six in the African region and four of India's neighbours -- Bhutan, China, Nepal and Malaysia, could be free of malaria by 2020, the World Health Organisation (WHO) has estimated in a report published on Monday to mark World Malaria Day.

One of the goals of WHO's 2016-2030 programme against malaria is to eliminate the disease in at least 10 countries by 2020.

To meet this target, a country must achieve at least one year of zero indigenous cases by 2020. 

"The 'Global Technical Strategy for Malaria 2016-2030', approved by the World Health Assembly in 2015, calls for the elimination of local transmission of malaria in at least 10 countries by 2020,” the Geneva-based organisation said in a statement.

"WHO estimates that 21 countries are in a position to achieve this goal, including six countries in the African Region, where the burden of the disease is heaviest,” the statement added.

"Our report shines a spotlight on countries that are well on their way to eliminating malaria,” said Pedro Alonso, director, WHO Global Malaria Programme. 

According to the WHO analysis presented in the report, these 21 countries are: Algeria, Belize, Bhutan, Botswana, Cabo Verde, China, Comoros, Costa Rica, Ecuador, El Salvador, Iran, Malaysia, Mexico, Nepal, Paraguay, Republic of Korea, Saudi Arabia, South Africa, Suriname, Swaziland and Timor-Leste.

"WHO commends these countries while also highlighting the urgent need for greater investment in settings with high rates of malaria transmission, particularly in Africa. Saving lives must be our first priority,” Alonso noted.

Since the year 2000, malaria mortality rates have declined by 60 percent globally, the report pointed out.

But reaching the next level -- elimination -- will not be easy, it added.

Nearly half of the world’s population, 3.2 billion people, remain at risk of malaria. Last year alone, 214 million new cases of the disease were reported in 95 countries and more than 400 000 people died of malaria, the report said

To make the world free of the disease, “new technologies must go hand in hand with strong political and financial commitment,” Alonso added.

Reaching the goals of the “Global Technical Strategy” will require a steep increase in global and domestic funding from $2.5 billion today to an estimated $8.7 billion annually by 2030, the report noted.​

​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.​