6th May 2015, 03:38 PM #1881
Re: Health Bulletin
கருப்பை புற்றுநோயை இரத்தப் பரிசோதனையில் கண்டறியலாம்: விஞ்ஞானிகள் தகவல்
பெண்களுக்கு ஏற்படும் கருப்பை புற்றுநோயை இரத்தப் பரிசோதனையின் மூலம் அறிந்து கொள்ள முடியும் என்று விஞ்ஞானிகள் நிரூபித்துள்ளனர்.
ஓவரியன் கேன்சர் என்று அழைக்கப்படும் கருப்பை புற்றுநோயை கண்டறியும் சாத்தியங்கள், இரத்தப் பரிசோதனையின் மூலம் கண்டறிவதன் மூலம் எளிதாகும்.
சுமார் 14 ஆண்டுகளாக நடைபெற்று வந்த இந்த ஆய்வில், ரத்தப் பரிசோதனை மூலம் இரண்டு மடங்கு துல்லியமாக கருப்பை புற்றுநோயை கண்டறிய முடியும் என்றும் நிரூபிக்கப்பட்டுள்ளது.
7th May 2015, 04:10 PM #1882
Re: Health Bulletin
Thermometer-like device could diagnose heart attacks
A simple, thermometer-like device that could make diagnosing heart attacks easier in remote or low-income locations has been developed.
Diagnosing a heart attack can require multiple tests using expensive equipment. But not everyone has access to such techniques, especially in remote or low-income areas.
Now scientists have developed a simple, thermometer-like device that could help doctors diagnose heart attacks with minimal materials and cost.
Sangmin Jeon from the Pohang University of Science and Technology in South Korea and colleagues note that one way to tell whether someone has had a heart attack involves measuring the level of a protein called troponin in the person's blood.
The protein's concentration rises when blood is cut off from the heart, and the muscle is damaged.
Today, detecting troponin requires bulky, expensive instruments and is often not practical for point-of-care use or in low-income areas.
Yet three-quarters of the deaths related to cardiovascular disease occur in low- and middle-income countries, researchers said.
Early diagnosis could help curb these numbers, so Jeon's team set out to make a sensitive, more accessible test.
Inspired by the simplicity of alcohol and mercury thermometers, the researchers created a similarly straightforward way to detect troponin.
It involves a few easy steps, a glass vial, specialised nanoparticles, a drop of ink and a skinny tube.
When human serum with troponin - even at a minute concentration - is mixed with the nanoparticles and put in the vial, the ink climbs up a protruding tube and can be read with the naked eye, just like a thermometer.
The research appears in the ACS journal Analytical Chemistry.
7th May 2015, 04:10 PM #1883
Re: Health Bulletin
Brain to blame for late-night snacking
People tend to snack at night because some areas of the brain do not get the same 'high' from food in the evening, a new study has found.
Researchers from Brigham Young University used MRI to measure how people's brains respond to high- and low-calorie food images at different times of the day.
The results showed that images of food, especially high-calorie food, can generate spikes in brain activity, but those neural responses are lower in the evening.
"You might over-consume at night because food is not as rewarding, at least visually at that time of day," said lead author Travis Masterson.
"It may not be as satisfying to eat at night so you eat more to try to get satisfied," Masterson said.
The study, which appears in the journal Brain Imaging and Behavior, also found that participants were subjectively more preoccupied with food at night even though their hunger and 'fullness' levels were similar to other times of the day.
For the study, researchers teamed up with BYU neuroscientist Brock Kirwan to use functional MRI to monitor the brain activity of study subjects while they viewed images of food.
The participants viewed 360 images during two separate sessions held one week apart - one during morning hours and one during evening hours.
Subjects looked at images of both low-calorie foods (vegetables, fruits, fish, grains) and high-calorie foods (candy, baked goods, ice cream, fast food).
As expected, the researchers found greater neural responses to images of high-calorie foods. However, they were surprised to see lower reward-related brain reactivity to the food images in the evening.
"We thought the responses would be greater at night because we tend to over-consume later in the day," said study co-author Lance Davidson, a professor of exercise sciences.
"But just to know that the brain responds differently at different times of day could have implications for eating," he said.
7th May 2015, 04:11 PM #1884
Re: Health Bulletin
Now, muscles created from onion cells
The humble onion is proving its strength outside the culinary world, enabling scientists to develop artificial muscles by using gold-plated cells of the vegetable.
Unlike previous artificial muscles, this one, created by a group of researchers from National Taiwan University, can either expand or contract to bend in different directions depending on the driving voltage applied. "The initial goal was to develop an engineered micro-structure in artificial muscles for increasing the actuation deformation (the amount the muscle can bend or stretch when triggered)," said researcher Wen-Pin Shih.
"One day, we found that the onion's cell structure and its dimensions were similar to what we had been making," said Shih, who lead the study. The onion epidermis is a thin, translucent layer of blocky cells arranged in a tightly-packed lattice. Shih and his colleagues thought that onion epidermal cells might be a viable candidate for the tricky task of creating a more versatile muscle that could expand or contract while bending.
8th May 2015, 01:37 PM #1885
Re: Health Bulletin
Can't stick to a diet? It's how we're wired
If you are finding it difficult to stick to a weight-loss diet, the hunger-sensitive cells in your brain are to be blamed, scientists say.
Researchers have found that a set of neurons is responsible for the unpleasant feelings associated with hunger that make snacking irresistible.
Scientists at the Howard Hughes Medical Institute's Janelia Research Campus said the AGRP neurons in the hypothalamus make sense from an evolutionary point of view.
In an environment where food is readily available, their difficult-to-ignore signal may seem like an annoyance but for earlier humans or animals in the wild, pursuing food or water can mean venturing into a risky environment, which might require some encouragement, researchers said.
AGRP neurons do not directly drive an animal to eat, but rather teach an animal to respond to sensory cues that signal the presence of food.
AGRP neurons are known to be clearly involved in feeding behaviours: When the body lacks energy, AGRP neurons become active, and when AGRP neurons are active, animals eat.
Postdoctoral researcher Nicholas Betley and graduate student Zhen Fang Huang Cao in a series of behavioural experiments offered well-fed mice two flavoured gels - one strawberry and the other orange. Neither gel contained any nutrients, but the hungry mice sampled them both.
Then the scientists' manipulated the hunger signals in the animals' brains by switching AGRP neurons on while they consumed one of the two flavours. In subsequent tests, the animals avoided the flavour associated with the false hunger signal.
In a reverse experiment, the scientists switched AGRP neurons off while hungry animals consumed a particular flavour. The animals developed a preference for the flavour choice that led to silencing of AGRP neurons, suggesting they were motivated to turn off the cells' unpleasant signal.
In further experiments, the scientists found that mice also learn to seek out places in their environment where AGRP neurons had been silenced and avoid places where those cells were active.
Next, postdoctoral researcher Shengjin Xu used a tiny, mobile microscope to peer inside the brains of hungry mice and monitor the activity of AGRP neurons. As expected, the cells were active until the mice found food.
What was surprising, Sternson said, is that mice did not actually have to eat to quiet the neurons. Instead, the cells ceased activity as soon as an animal saw food - or even a signal that predicted food. And their activity remained low while the animal was eating.
That wouldn't make sense if the job of AGRP neurons was to make food taste better or if they directly controlled the individual actions that go into eating, which were two possibilities, said Scott Sternson, group leader at Janelia.
But to encourage eating, a negative signal would need to turn off when an animal consumed food, he said.
The findings are published in the journal Nature.
9th May 2015, 02:44 PM #1886
Re: Health Bulletin
An onion a day, keeps the doctor away
An onion a day keeps the doctor away. True. Researchers at the Allahabad University have proved that switching over to onion (around Rs 10 per kg) from apple (Rs 120 per kg) will provide the same nutritional value without burning a whole in your pocket.
Onion has the potential of replacing apple. It also helps in fighting against various ailments effecting eyes, kidney, brain and blood circulation system, researches conducted by head of the biochemistry department, Allahabad University, Syed Ibrahim Rizvi and assistant professor Neetu Mishra, have shown.
Consumption of onion and apple is beneficial for diabetics. Both apple and onions are equally rich in a substance called 'quercetin', which enters the cell and adds to the capacity of human body in fighting oxidative stress, which is responsible for causing diabetes and complications associated with it, the research has shown.
"We have the experimental proof of protecting effect of 'quercetin' against the increased oxidative stress in normal humans. Diabetics are known to have increased oxidative stress. Higher intake of diet rich in 'quercetin' may protect diabetic patients from complications arising due to oxidative stress," said Rizvi.
He said that blood sample of 31 diabetics, from 58 to 75 years in age, was taken. Among them, 18 were men and 13 women. Care was taken to select patients with no family history of diabetes mellitus or hypertension (high blood pressure) for the last two generations and see that none of the women was receiving hormonal treatment.
Quercetin was than studied on human's red blood cells (RBCs).
It was observed that quercetin present in onions and apples protected RBC from the harmful effect of oxidative stress and it is absorbed much more from the human intestinal tract into the blood stream, he added.
9th May 2015, 02:49 PM #1887
Re: Health Bulletin
Natural substance to prevent dental plaque identified
An amino acid found naturally in meat, poultry, fish and dairy products breaks down dental plaque, which could help millions of people avoid cavities and gum disease, a new research has found.
Already used in dental products for tooth sensitivity, the amino acid, arginine, stops the formation of dental plaque, the findings showed.
The findings suggest that the naturally found compound could one day replace the chemical substances currently used in dental plaque control methods.
"This is important as bacteria like to aggregate on surfaces to form biofilms. Dental plaque is a biofilm," said one of the researchers Alexander Rickard, assistant professor at the University of Michigan.
"Biofilms account for more than 50 percent of all hospital infections. Dental plaque biofilms contribute to the billions of dollars of dental treatments and office visits every year in the United States."
Dental biofilms are the culprits in the formation of dental caries (cavities), gingivitis and periodontal disease.
Most methods for dental plaque control involve use of antimicrobial agents, such as chlorhexidine, which are chemicals aimed at killing plaque bacteria, but they can affect sense of taste and stain teeth.
Antimicrobial treatments have been the subject of debate about overuse in recent years.
Pending further clinical trials to verify their lab findings, the researchers said L-arginine could take the place of the current plaque-controlling biocide substances including chlorhexidine and other antimicrobials.
In conducting their research, team members used a model system they introduced in 2013 that mimics the oral cavity. The researchers were able to grow together the numerous bacterial species found in dental plaque in the laboratory, using natural human saliva.
11th May 2015, 12:40 PM #1888
Re: Health Bulletin
Master protein that initiates organ formation found
Researchers have identified the "master" protein that directs the development of multi-cellular animals.
One of developmental biology's most perplexing questions concerns what signals transform masses of undifferentiated cells into various organs.
The new research provides evidence that it all begins with a single "master" growth factor receptor that regulates the entire genome.
At the centre of the discovery is a single protein called nuclear Fibroblast Growth Factor Receptor 1 (nFGFR1).
"FGFR1 occupies a position at the top of the gene hierarchy that directs the development of multicellular animals," said study senior author Michal Stachowiak from University at Buffalo in the US.
The FGFR1 gene is known to govern gastrulation, occurring in early development, where the three-layered embryonic structure forms.
It also plays a major role in the development of the central and peripheral nervous systems and the development of the body's major systems, including muscles and bones.
"The finding provides a new level of understanding of the fundamental aspects of how organisms develop," Stachowiak said.
"Our research shows how a single growth factor receptor protein moves directly to the nucleus in order to programme the entire genome," he said.
A more advanced understanding of how organisms form, based on this work, has the potential to significantly enhance the understanding and treatment of cancers, which result from uncontrolled development as well as congenital diseases, the researchers pointed out.
The new research also would contribute to the understanding of how stem cells work.
"We have known that the human body has almost 30,000 genes that must be controlled by thousands of transcription factors that bind to those genes, yet we did not understand how the activities of genes were coordinated so that they properly develop into an organism, " Stachowiak said.
"Now we think we have discovered what may be the most important player, which organises this cacophony of genes into a symphony of biological development with logical pathways and circuits," he said.
This work was conducted on mouse embryonic stem cells, not human cells.
The study appeared in the journal PLOS ONE.
12th May 2015, 01:01 PM #1889
Re: Health Bulletin
New device blocks pain signals from reaching brain
A new implantable device could soon put the minds of chronic pain sufferers at ease by distributing the body's own natural pain relief signals at just the right time.
Researchers at Linkoping University (LiU) and Karolinska Institutet (KI) in Sweden are the first in the world with technology that can stop pain impulses in living, freely moving rats using the body's own pain relief signals.
The implantable "ion pump" that delivers the body's own pain alleviators with exact dosage precisely to the location where the pain signals reach the spinal cord for further transmission to the brain, could be in clinical use in five to ten years, researchers said.
Firstly, the device gives hope to the seven per cent of the world's population suffering from nerve pain for whom no other cure has been found - until now, researchers said.
But the pump could also be used to supply therapeutic substances to the brain and other parts of the body in addition to the spinal cord.
"The ion pump can be likened to a pacemaker, except for alleviating pain," said Professor Magnus Berggren, head of the research.
While a pacemaker sends electrical impulses to the heart, the ion pump sends out the body's own pain alleviator - charged molecules of what are known as neurotransmitters - to the exact place where the damaged nerves come into contact with the spinal cord.
This means that the pain impulses never reach the brain. In this case, the device delivers the neurotransmitter gamma-aminobutyric acid (GABA), whose natural task is to inhibit stimuli in our central nervous system.
Researchers constructed the therapeutic implant using organic electronics - a class of materials capable of easy translation between electronic and biochemical signals - and that it has been used to block pain impulses in awake, freely-moving rats.
With the help of the ion pump, positively-charged ions can be administered in four different locations, adapted according to the exact points where the nerve endings meet the spinal cord.
An electric current through the ion pump is all that is needed for the GABA neurotransmitter to be spread as a thin cloud at these exact locations on the spinal cord. So far, the pain alleviation has had no negative side effects.
"What's unique is that we're using organic electronics to send the body's own chemical signals. The organic materials are easily accepted by the body, and they communicate just as in biology - with charged ions," said Assistant Professor Daniel Simon.
12th May 2015, 01:02 PM #1890
Re: Health Bulletin
Drug-resistant typhoid strain is spreading, warn experts
An antibiotic-resistant "superbug" strain of typhoid fever has spread globally, driven by a single family of the bacteria, called H58, according to the findings of a large international study.
The research, involving some 74 scientists in almost two dozen countries, is one of the most comprehensive sets of genetic data on a human infectious agent and paints a worrying scene of an "ever-increasing public health threat", they said.
Typhoid is contracted by drinking or eating contaminated matter and symptoms include nausea, fever, abdominal pain and pink spots on the chest. Untreated, the disease can lead to complications in the gut and head, which may prove fatal in up to 20% of patients.
Vaccines are available and regular strains of the infection can be treated with antibiotic drugs. However, this study found that the H58 "superbug" version, which is resistant to multiple types of antibiotics, is now becoming dominant.
"H58 is displacing other typhoid strains, completely transforming the genetic architecture of the disease and creating a previously under appreciated and on-going epidemic," the researchers said. Vanessa Wong of Britain's Wellcome Trust Sanger Institute said that since typhoid affects around 30 million people a year, detailed good global surveillance is critical to trying to contain it.