New eye layer may help treat blindness

London: An Indian-origin scientist in the UK has discovered an ultra-thin layer hidden deep in the eye that may help cure blindness caused by glaucoma.

The new layer in the human cornea, discovered by Professor Harminder Dua, of Nottingham University, plays a vital role in the structure of the tissue that controls the flow of fluid from the eye, research has shown.

The findings could shed new light on glaucoma, a devastating disease caused by defective drainage of fluid from the eye and the world's second leading cause of blindness, researchers said.

The latest research shows that the new layer, dubbed Dua's Layer, makes an important contribution to the sieve-like meshwork, the trabecular meshwork (TM), in the periphery of the cornea.The TM is a wedge-shaped band of tissue that extends along the circumference of the angle of the anterior chamber of the eye.

It is made of beams of collagen wrapped in a basement membrane to which trabecular cells and endothelial cells attach. The beams branch out randomly to form a 'meshwork'. Pressure within the eye is maintained by the balance of aqueous fluid production by eye tissue called the ciliary body
and drainage principally through the TM to the canal of Schlemm, a circular channel in the angle of the eye.

Defective drainage through the TM is an important cause of glaucoma, a condition that leads to raised pressure in the eye that can permanently affect sight, researchers said. Around 1 to 2 per cent of the world's population yearly have chronic glaucoma and globally around 45 million people have open angle glaucoma which can permanently damage the optic nerve - 10 per cent of whom are blind, researchers said.

The latest research sheds new light on the basic anatomy of Dua's Layer, which is just 15 microns thick but incredibly tough. Comprised of thin plates of collagen, it sits at the back of the cornea between the corneal stroma and Descemet's membrane.

By examining human donor eyes using electron microscopy, the researchers were able to look at Dua's Layer beyond the central part of the cornea to shed more light on its features at the extreme periphery of the cornea.

It is hoped the discovery will offer new clues on why the drainage system malfunctions in the eyes of some people, leading to high pressure.

The research was published in the British Journal of Ophthalmology.

Dogs too suffer from obsessive compulsive disorder!

Washington: Man's best friend can also suffer from obsessive compulsive disorder, say scientists who have identified four genes that are connected to OCD in dogs.   

Researchers said few breeds of dogs exhibit particularly high rates of OCD. These include Doberman Pinschers, bull terriers, Shetland sheepdogs and German shepherds, according to a report.

OCD is an anxiety disorder characterised by intrusive thoughts that produce uneasiness, apprehension, fear, or worry; by repetitive behaviours aimed at reducing the associated anxiety; or by a combination of such obsessions and compulsions, PTI reported.

Dogs with OCD may display behaviours such as incessant tail chasing, repetitive shadow stalking and relentless paw chewing.
Since dogs are genetically simpler than people, researchers turned to these canines in their search for OCD-related genes, 'Discovery News' reported. Elinor Karlsson, a computational biologist at the Broad Institute at Harvard University, and colleagues began by sequencing and comparing a large section of the genomes of 90 Dobermans that had OCD with 60 that didn't. They also searched for genes that looked the same in all of the Dobermans but that differed between that breed and
others.
When they had zeroed in on several suspicious areas of the genome, the researchers compared the suspect Doberman genes with genes from a sample of the three other breeds that also suffer higher-than-usual rates of OCD. Those analyses pinpointed four genes that have unusually high rates of mutations in dogs with obsessive and compulsive behaviours.
The genes implicated in the new study play roles in pathways that have also been connected to human OCD, Karlsson said, suggesting that dogs could provide a helpful model system for developing better treatments for people. The study was published in the journal Genome Biology.

Common HIV drug can kill HPV causing cervical cancer

London: In a world-first clinical trial, scientists have found that a commonly-used HIV drug can kill off the human papilloma virus (HPV) that leads to cervical cancer.

The trial was led by The University of Manchester in UK with Kenyatta National Hospital (KNH) in Nairobi. Researchers examined Kenyan women diagnosed with HPV positive early stage cervical cancer who were treated with the antiviral HIV drug lopinavir in Kenya.

The study looked at 40 women with both high and low-grade pre-cancerous disease of the cervix and the antiviral drug, normally used orally to treat HIV, was self-applied directly to the cervix as a pessary.

The results showed a high proportion of women diagnosed with HPV positive high-grade disease returned to normal following a short course of the new treatment, a report said.

The women were treated with one capsule of the antiviral drug twice a day for 2 weeks.

Repeat cervical smears showed a marked improvement within one month of the treatment although after three months, there was a definite response.

Out of 23 women initially diagnosed with high-grade disease, 19 (82.6 per cent) had returned to normal and two now had low-grade disease giving an overall positive response in 91.2 per cent of those treated. Furthermore, the 17 women initially diagnosed with borderline or low-grade disease also showed similar improvement.

Photographic images of the cervix before and after treatment showed clear regression of the cervical lesions and no adverse reactions were reported.

"For an early stage clinical trial the results have exceeded our expectations. We have seen women with high-grade disease revert to a normal healthy cervix within a comparatively short period of time," said Dr Ian Hampson from the Manchester University's Institute of Cancer Sciences, according to a PTI report.

"We are convinced that further optimisation of the dose and treatment period will improve the efficacy still further," Hampson said.

"Current HPV Vaccines are prophylactics aimed at preventing the disease rather than curing or treating symptoms. Other than surgery, as yet there is no effective treatment for either HPV infection or the pre-cancerous lesion it causes which is why these results are so exciting," added
Dr Lynne Hampson from Manchester University.

"Further work is needed but it looks as though this might be a potential treatment to stop early stage cervical cancer caused by HPV," Lynne said.

Spit-test can predict risk of depression in teens

London: Cambridge scientists have identified the first biomarker for clinical depression after they found that high levels of stress hormone in spit can indicate a serious risk of developing psychiatric disorders in teen boys.
 

Teenage boys with symptoms of depression and raised levels of the stress hormone cortisol are up to 14 times more likely to develop major depression than those without these traits, researchers found.
Clinical depression affects one in six people at some point in their lives. Until now, doctors have lacked a biomarker for clinical depression, partly because its causes and symptoms are so varied.
 

"Through our research, we now have a very real way of identifying those teenage boys most likely to develop clinical depression," said Professor Ian Goodyer of the University's Department of Psychiatry who led the study.
 

"This will help us strategically target preventions and interventions at these individuals and hopefully help reduce their risk of serious episodes of depression and their consequences in adult life," Goodyer said. The researchers collected spit samples from hundreds of teenagers and measured levels of cortisol in the saliva, as well as self-reported information on symptoms of depression.
 

This they used to divide the teenagers into one of four groups depending on their cortisol levels and symptoms of depression.
 

After following the group for 12 to 36 months, they were then able to work out which group was most likely to develop clinical depression and other psychiatric disorders. They found boys with high levels of cortisol and depressive symptoms were 14 times more likely to develop clinical depression than those with neither. In girls, however, this difference was less marked.
 

Girls with high cortisol and depressive symptoms were four times more likely to develop clinical depression than those with neither, suggesting gender differences in how depression develops.
 

The researchers hope that having an easily measurable biomarker - in this case, raised cortisol plus depressive symptoms - will allow primary care services to identify boys at high risk and consider new public mental health strategies for this part of the population.
 

"This new biomarker suggests that we may be able to offer a more personalised approach to tackling boys at risk for depression," said co-author Dr Matthew Owens.
 

The study was published in Proceedings of the National Academies of Science.

Scientists closer to find vaccine for dengue

Washington: Scientists have unveiled the mechanism behind how dengue enters cells of our immune system, a finding that could help develop vaccine for the deadly virus.

Dengue fever, an infectious tropical disease caused by a mosquito-borne virus, afflicts millions of people each year, causing fever, headache, muscle and joint pains and a characteristic skin rash, a PTI report quoting researchers, said.

In some people the disease progresses to a severe, often fatal, form known as dengue hemorrhagic fever. Despite its heavy toll, the prevention and clinical treatment of dengue infection has been a "dramatic failure in public health compared to other infectious diseases like HIV," said Ping Liu of the University of North Carolina at Chapel Hill.

Now, new research by Liu and her colleagues could offer vital insight into the mechanism of dengue virus entry into cells - and aid vaccine and clinical drug development.

Liu along with dengue fever expert Aravinda de Silva, used high-resolution microscopes to examine the expression of a particular protein, known as DC-SIGN, on the surface of immune system cells called dendritic cells.

The normal role of DC-SIGN (dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin) is to capture pathogens so that fragments of those pathogens can be presented as antigens on the surface of the dendritic cells.

Such antigens then are recognised by T cells - the workhorse cells of the immune system - "which is one of the first steps in the normal immune response," Liu said. While it has been known for some time that dengue used DC-SIGN to attach to cells, Liu and her colleagues used high-resolution microscopy to study exactly how the viruses used the protein to gain entry into cells.

"DC-SIGN has a unique carbohydrate recognition domain on its extracellular portion, which binds to all sorts of carbohydrates on pathogens," she said.

"An effective medication or vaccine should stop the process of dengue virus entry into cells," Liu said.
She said, de Silva and his colleagues have identified strong neutralisation antibodies that block dengue infection. By identifying the mechanism of antibody neutralisation, Liu and colleagues hope to advance the development of vaccines for dengue virus infections.

Scientists find safe way to kill cancer cells

Washington: Indian-origin scientists have successfully developed a radical new technique that may kill
brain tumours by hijacking them into toxic pits or areas of the body that are safer to operate on.

One factor that makes glioblastoma cancers so difficult to treat is that malignant cells from the tumours spread throughout the brain by following nerve fibres and blood vessels to invade new locations.     Now, researchers have learned to hijack this migratory mechanism, turning it against the cancer by using a film of nanofibres thinner than human hair to lure tumour cells away, a media report quoting PTI, said.

Instead of invading new areas, the migrating cells latch onto the specially-designed nanofibres and follow them to a location - potentially outside the brain - where they can be
captured and killed.

Using this technique, researchers can partially move tumours from inoperable locations to more accessible ones. Though it would not eliminate the cancer, the new technique reduced the size of brain tumours in animal models, suggesting that this form of brain cancer might one day be treated more like a chronic disease, researchers said.

"We have designed a polymer thin film nanofibre that mimics the structure of nerves and blood vessels that brain tumour cells normally use to invade other parts of the brain," said Ravi Bellamkonda, lead investigator and chair of the Wallace H Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

"The cancer cells normally latch onto these natural structures and ride them like a monorail to other parts of the brain. By providing an attractive alternative fibre, we can efficiently move the tumours along a different path to a destination that we choose," said Bellamkonda.

Treating the Glioblastoma multiforme cancer, also known as GBM, is difficult because the aggressive and invasive cancer often develops in parts of the brain where surgeons are
reluctant to operate.

Even if the primary tumour can be removed, however, it has often spread to other locations before being diagnosed. "The signalling pathways we were trying to activate to repair the spinal cord were the same pathways researchers would like to inactivate for glioblastomas," said first author
of the study, Anjana Jain, an assistant professor in the Department of Biomedical Engineering at Worcester Polytechnic Institute in Massachusetts.

Tumour cells typically invade healthy tissue by secreting enzymes that allow the invasion to take place, Jain said. That activity requires a significant amount of energy from the cancer cells.
"Our idea was to give the tumour cells a path of least resistance, one that resembles the natural structures in the brain, but is attractive because it does not require the cancer cells to expend any more energy," she said.

Details of the technique were reported in the journal Nature Materials.

Stay healthy with a glass of wine a day

Washington: Moderate alcohol consumption can boost your immune system and potentially improve your ability to fight infections, a new study has claimed.
 

A research team led by an immunologist at the University of California, Riverside found that moderate consumption of alcohol can improve immune response to vaccination.
 

The finding could pave the way for potentially new interventions to improve our ability to respond to vaccines and infections, benefiting vulnerable populations, such as the elderly for whom the flu vaccine, for example, has been found to be largely ineffective.
 

"It has been known for a long time that moderate alcohol consumption is associated with lower mortality," said Ilhem Messaoudi, an associate professor of biomedical sciences in the School of Medicine and lead author of the study published in the journal Vaccine.
 

"Our study, conducted on non-human  primates, shows for the first time that voluntary moderate alcohol consumption boosts immune responses to vaccination," Messaoudi said.
 

To study the impact of alcohol consumption on the immune system, the researchers trained 12 rhesus macaques to self-administer/consume alcohol on their own accord. The team first vaccinated the animals (against small pox) and then allowed them to access either 4 per cent ethanol (the experimental group) or calorically matched sugar water (the control group).
 

All the animals also had open access to water as an alternative fluid, as well as food. The researchers monitored the animals' daily ethanol consumption for 14 months. The animals were vaccinated one more time, seven months after the experiment began.
 

The research team found that over nine months of the animals' ethanol self-administration, mean daily ethanol intake varied markedly among them. "Like humans, rhesus macaques showed highly variable drinking behaviour. Some animals drank large volumes of ethanol, while others drank in moderation," Messaoudi said.
 

The animals' voluntary ethanol consumption segregated them into two groups: animals in the first group were those that consumed more alcohol, averaged a blood ethanol concentration (BEC) greater than the legal limit of 0.08 per cent and were therefore designated 'heavy drinkers'; animals in the second group consumed less alcohol, averaged a BEC of 0.02-0.04 per cent and were designated 'moderate drinkers.'
 

"Prior to consuming alcohol, all the animals showed comparable responses to vaccination. Following exposure to ethanol, however, the animals showed markedly different responses after receiving the booster vaccine," Messaoudi said. The researchers found that those animals that drank the
largest amounts of alcohol showed greatly diminished vaccine responses compared to the control group.