Research

New layer of cornea discovered by Indian doctor Harminder Dua

A new layer in the human cornea was discovered by the Indian doctor Harminder Dua at The University of Nottingham in 2014. It plays a vital role in the structure of the tissue that controls the flow of fluid from the eye.

The research was published in a paper in the British Journal of Ophthalmology.
The new finding could shed new light on glaucoma. The new layer named as Dua’s Layer 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.

It 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’.
Scientists had previously believed the cornea to be comprised of five layers – from front to back— the corneal epithelium, Bowman’s layer, the corneal stroma, Descemet’s membrane and the corneal endothelium.

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. Around 1 to 2% 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% of whom are blind.

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.
Glaucoma is a devastating disease caused by defective drainage of fluid from the eye. Glaucoma is the second largest leading cause of blindness of world.

Source: Zee News

 

Research links father’s gene to baby’s birth weight

Research suggests that expression of the father’s genes enhances a baby’s growth.

A father’s genetic code influences the weight of a baby at birth, according to a new study. The study led by the UCL Institute of Child Health (ICH) suggests that genes inherited from the mother and father regulate a baby’s growth at different times during the pregnancy, to ensure a successful birth as well as the mother’s survival.

Low birth weight is a well-known risk factor for Type 2 diabetes and cardiovascular problems in later life. One group of growth genes of particular interest are the imprinted genes inherited from one’s parents. If the paternal one is expressed, the maternal one is imprinted (silenced) and vice versa.

The ‘parental conflict hypothesis’ suggests that expression of the father’s genes enhances a baby’s growth, improving the success of the paternal genome to be passed on. In contrast, the mother’s genome limits foetal growth, distributing equal resources to each of her offspring, whilst ensuring her own survival post-birth allowing her to reproduce again.

The study, published in the journal PLOS ONE, looked at the relationship between birth weight and the paternally expressed Insulin-like growth factor 2 (IGF2) early in gestation, where IGF2 is a key hormone regulating growth in the womb. Professor Gudrun Moore, lead author at the UCL Institute of Child Health, says most of us think of both the mother’s and father’s genes as having an equal influence on birth weight, but this does not appear to be the case.

“Our study suggests that the two parental genomes may be acting at different times during the pregnancy in order to control the baby’s size. Whilst greater foetal growth appears to be promoted by the father’s genes early on, it must still require careful regulation by the mother to ensure a successful birth,” he said. He added that understanding the genetic basis of foetal growth is of critical importance in the prevention and monitoring of small and low weight babies.

Source: The Indian Express

 

Pain ‘dimmer switch’ discovered by UK scientists

Pain sensitivity is controlled by a genetic “dimmer switch”, which can be re-set, UK scientists have discovered.

Twins sharing 100% of genes have different pain thresholds, which can potentially be altered by lifestyle or medication, say researchers at King’s College, London.

The study could lead to new painkillers or lifestyle interventions, they report in Nature Communications.

One in five of the population suffers from acute or chronic pain.

Lead researcher Dr Jordana Bell said the potential to regulate genes involved in pain sensitivity “is very exciting and could lead to a more effective pain relief treatment for patients suffering with chronic pain”.

Sensitivity to pain is complex, with wide individual variation. Previous studies have suggested about half of the influence is explained by genes.

To identify levels of sensitivity to pain, scientists tested 25 pairs of identical twins using a heat probe placed on the arm.

Identical twins share 100% of their genes; therefore any difference between identical twins must be due to their environment or changes affecting the function of their genes.

Study participants were asked to press a button when the heat became painful for them, which allowed the researchers to determine their pain thresholds.

Using DNA sequencing, the researchers examined the whole genetic codes (genomes) of the twins and compared them with 50 unrelated individuals.

The research team found chemical changes within nine genes involved in pain sensitivity that were different in one twin but not in her identical sister.

These were most significant within a known pain sensitivity gene, which is already a target for the development of new painkillers.

Research into the switching on and off of genes, a process known as epigenetic regulation, is a big growth area for the development of new medicines.

‘Landmark’ study
Tim Spector, professor of genetic epidemiology at King’s College London, said epigenetic switching is “like a dimmer switch for gene expression”.

“This landmark study shows how identical twins, when combined with the latest technology to look at millions of epigenetic signals, can be used to find the small chemical switches in our genes that make us all unique – and in this case respond to pain differently.”

The chemical changes act like a “thermostat” or “dimmer switch” to set an individual’s pain sensitivity, Prof Spector added.

“Using drugs or changes in lifestyle, we might be able to reset that thermostat, allowing that person in the future to feel less pain,” he told BBC News.

“The epigenetic changes are potentially reversible.”

Source: BBC news

Cold weather can help you lose weight, study says

Keeping temperatures a bit chillier at home and work, even when it’s as cold as it is now, can make your body burn more calories to keep warm, Dutch researchers say.

Americans love to crank up the thermostat, especially in bitterly cold times like these.

But a new study suggests turning it down a few degrees could actually help you lose weight.

We know. Not what you wanted to hear right now.

But Dutch researchers say regular exposure to mildly cold temperatures can make your body burn more calories to keep warm.

“Since most of us are exposed to indoor conditions 90 percent of the time, it is worth exploring health aspects of ambient temperatures,”. “What would it mean if we let our bodies work again to control body temperature?”

Lichtenbelt and his team have been studying the phenomena for the past 10 years.

While most animals (humans included) shiver to stay warm, another type of shivering — called non-shivering thermogenesis — occurs when the temperature is cool but not cold, according to the research.

That type of shivering, activating what’s called “brown fat,” can burn up to 30 percent of the body’s energy and contribute to weight loss.

Brown fat, discovered in adults in 2009, burns calories instead of storing them like white fat.

So does this mean you should crank the heat down to 55 degrees and frolic about in a tank top and underwear?

Not necessarily. It’s more theory at this point, but researchers also said it wouldn’t hurt.

“It would do no harm,” Dr. Mitchell Lazar, chief of the division of endocrinology, diabetes and metabolism at the University of Pennsylvania, told HealthDay. “It’s worth a try for someone who is having trouble losing weight by diet and exercise alone.”

Source: global post

Pill camera to screen for colon cancer approved in U.S.

An ingestible pill camera to help screen for polyps and early signs of colon cancer has been approved for use in the U.S.

Given Imaging Ltd.’s PillCam Colon was originally touted as an alternative to traditional colonoscopy procedures, but the company’s research found images taken by the mini-camera aren’t as clear as those taken during the more invasive procedure.

The U.S. Food and Drug Administration approved the device for patients who have experienced an incomplete colonoscopy. The company estimates 750,000 U.S. patients are not able to complete the procedure each year, due to anatomy issues, previous surgery or various colon diseases.

“Colonoscopy is the most comprehensive option, but for up to 10 per cent of individuals, achieving a complete colonoscopy may not be possible,” Eric Hargis, CEO of the Colon Cancer Alliance, said in a release.

In 2001, Given Imaging received FDA approval for a similar device that images the small intestine.

The newly approved capsule has two miniature colour video cameras, a battery and light source. Once the patient ingests the capsule, it is designed to transmit images for about 10 hours.

Data is transferred from the device to a computer to be compiled. A doctor later reviews and reports the results.

Risks of the procedure include capsule retention, aspiration and skin irritation. Before the capsule is excreted, patients should not be near powerful electromagnetic fields, such as those created by an MRI device.

The PillCam Colon is commercially available in Canada, Japan, Europe, Latin America, Australia and parts of Asia and Africa.

Given Imaging also develops technology to visualize, diagnose and monitor the digestive system, including with its PillCam, a swallowed capsule endoscope.

A report by the Canadian Partnership Against Cancer suggested that in 2011, half of Canadians aged 50 to 74 surveyed said they were up to date with their colorectal cancer screening — a fecal occult blood test in the past two years and colonoscopy in the past five years.

Last month, Alberta Health Services announced a new at-home, non-invasive screening test called “fit” – a fecal immunochemical test – for people aged of 50 to 74 at average risk of colorectal cancer.

A review of 19 studies published in Monday’s online issue of the Annals of Internal Medicine concluded FITs have high overall diagnostic accuracy for colorectal cancers.

Like the traditional fecal occult stool test, FIT involves collecting a stool sample at home to look for traces of blood. People using FIT don’t need to restrict their diet or stop taking medications.

Source: CBC news

Cells from Dead people’s eyes helps blind people

Researchers have suggested that cells taken from the donated eyes of dead people may be able to give sight to the blind.

Tests in rats showed that the human cells can restore some vision to completely blind rats.

The team at University College London said similar results in humans would improve quality of life, but would not give enough vision to read.

The team extracted a special kind of cell from the back of the eye. These Muller glia cells – a type of adult stem cell – is capable of transforming into the specialized cells in the back of the eye and could be useful for treating a wide range of sight
disorders.

In the lab, the cells were transformed into rod cells that detected light in the retina, and injecting the rods into the backs of the eyes of completely blind rats partially restored their vision.

Brain scans showed that 50 percent of the electrical signals between the eye and the brain made a recovery after the treatment.

The study has been published in journal Stem Cells Translational Medicine.

Source: Zee News

Neurons in spinal cord send Cc of commands back to brain

Research group led by Professor Silvia Arber at the University of Basel’s Biozentrum and the Friedrich Miescher Institute for Biomedical Research has now discovered, that many neurons in the spinal cord send their instructions not only towards the musculature, but at the same time also back to the brain via an exquisitely organized network.
This dual information stream provides the neural basis for accurate control of arm and hand movements.

Movements of our arms and hands, in particular, call for extremely precise coordination.
The brain sends a constant stream of commands via the spinal cord to our muscles to execute a wide variety of movements.

This stream of information from the brain reaches interneurons in the spinal cord, which then transmit the commands via further circuits to motor neurons innervating muscles.

The research group led by Silvia Arber at the Biozentrum of the University of Basel and the Friedrich Miescher Institute for Biomedical Research has now elucidated the organization of a second information pathway taken by these commands.
The scientists showed that many interneurons in the mouse spinal cord not only transmit their signals via motor neurons to the target muscle, but also simultaneously send a copy of this information back to the brain.

“The motor command to the muscle is sent in two different directions – in one direction, to trigger the desired muscular contraction and in the other, to inform the brain that the command has actually been passed on to the musculature,” Chiara Pivetta, first author of the publication, said.

In analogy to e mail transmission, the information is thus not only sent to the recipient but also to the original requester.
What happens to the information sent by spinal interneurons to the brain? As Arber’s group discovered, this input is segregated by function and spatially organized within a brainstem nucleus.

Information from different types of interneurons thus flows to different areas of the nucleus. For example, spinal information that will influence left-right coordination of a movement is collected at a different site than information affecting the speed of a movement.

The findings are published in the journal Cell.

Source: Yahoo news

New drug target for Alzheimer’s identified

Researchers have identified abnormal expression of genes, resulting from DNA relaxation, that can be detected in the brain and blood of Alzheimer’s patients.

The protein tau is involved in a number of neurodegenerative disorders, including Alzheimer’s disease.

Previous studies have implicated DNA damage as a cause of neuron, or cell, death in Alzheimer’s patients.

Given that DNA damage can change the structure of DNA within cells, the researchers led by Bess Frost examined changes in DNA structure in tau-induced neurodegeneration.

They used transgenic flies and mice expressing human tau to show that DNA is more relaxed in tauopathy.

They then identified that the relaxation of tightly wound DNA and resulting abnormal gene expression are central events that cause neurons to die in Alzheimer’s disease.

“Our work suggests that drugs that modify DNA structure may be beneficial for treating Alzheimer’s Disease,” they wrote.

The study is published in the journal Nature Neuroscience.

Source: Business Standard

Being shorter may lead to feelings of inferiority, study says

A new study published in Psychiatry Today found that people who had their height “virtually lowered” felt inferior and mistrustful.

British researchers studied a group of 60 adult women who used a virtual reality (VR) simulation to take two rides on the London Underground subway. On the first trip, the participant’s perceived height was unaltered, but on their second simulated trip, their perceived height was lowered by 9.84 inches.

The participants commented on their experience, and after the second ride, there was a significant increase in reports of negative feelings – such as incompetence, inferiority and feeling unlikeable. Respondents also showed an increase in feelings of paranoia toward other virtual “passengers” on the train. Most participants did not realize their height had been lowered for the second round of the simulation.

Researchers said that people mostly behave the same in a VR environment as they do in real life.

The researchers noted that the participants were women who “were prone to having mistrustful thoughts,” but they say the new study provides key insight into paranoia.

people’s excessive mistrust of others directly builds upon their own negative feelings about themselves, lead researcher Daniel Freeman, professor at the University of Oxford, told Medical News Today. “The important treatment implication for severe paranoia that we can take from this study is that if we help people to feel more self-confident, then they will be less mistrustful.”

Source: News BCC

Faster way to catch food poisoning microbes

A team of scientists, led by an Indian-origin researcher Sibani Lisa Biswal, has developed a faster method to catch unwanted microbes before they can make people sick with food poisoning.

The Rice University scientists used an array of tiny ‘nanomechanical cantilevers’, anchored at one end, kind of like little diving boards.

The cantilevers have peptides attached to them that bind to Salmonella – one of the pathogens most commonly associated with foodborne illness which can cause fever, diarrhoea and abdominal cramps.

When the bacteria bind to the peptides, the cantilever arm bends, creating a signal.

The screening system rapidly distinguished Salmonella from other types of bacteria in a sample.

One of the peptides could tell eight different types of Salmonella apart from each other.

The researchers stated that the technique could be applied to other common food pathogens.

“The new approach for pathogen screening is far faster than current commercial methods,” said Biswal, assistant professor of chemical and biomolecular engineering at Rice University.

Conventional methods to detect harmful bacteria in food are reliable and inexpensive, but they can be complicated, time consuming and thus allow contamination to go undetected.

The findings are reported in the ACS journal Analytical Chemistry.

Source: sify