19th Mar 2014, 02:04 AM #901
Re: Health Bulletin
3,200-year-old skeleton with cancer found in Sudan
Archaeologists have discovered 3,200-year-old skeleton of a young man with a spreading form of cancer, the oldest known example of the disease often linked to a modern lifestyle.
The skeleton of the young adult male estimated to be between 25-35 years old was found in a tomb in modern Sudan in 2013 and dates back to 1200BC.
Analysis showed evidence of metastatic carcinoma - which spreads to other parts of the body from where it started - from a malignant soft-tissue tumour spread across large areas of the body, making it the oldest convincing complete example of metastatic cancer in the archaeological record.
Researchers said the discovery will help to explore underlying causes of cancer in ancient populations and provide insights into the evolution of cancer in the past.
Even though cancer is one of the world's leading causes of death, it remains almost absent from the archaeological record compared to other pathological conditions, giving rise to the conclusion that the disease is mainly a product of modern living and increased longevity.
These findings suggest that cancer is not only a modern disease but was already present in the Nile Valley in ancient times.
"Insights gained from archaeological human remains like these can really help us to understand the evolution and history of modern diseases," said lead author Michaela Binder from the Durham University, who excavated and examined the skeleton.
"Our analysis showed that the shape of the small lesions on the bones can only have been caused by a soft tissue cancer even though the exact origin is impossible to determine through the bones alone," Binder said.
The skeleton is of an adult male was found at the archaeological site of Amara West in northern Sudan, situated on the Nile, 750km downstream of the capital Khartoum.
It was buried extended on his back, within a badly deteriorated painted wooden coffin, and provided with a glazed faience amulet as a grave good.
Previously, there has only been one convincing, and two tentative, examples of metastatic cancer predating the 1st millennium BC reported in human remains.
However, because the remains derived from early 20th century excavations, only the skulls were retained, thus making a full re-analysis of each skeleton, to generate differential (possible) diagnoses, impossible.
The skeleton was examined by using radiography and a scanning electron microscope (SEM) which resulted in clear imaging of the lesions on the bones.
It showed cancer metastases on the collar bones, shoulder blades, upper arms, vertebrae, ribs, pelvis and thigh bones.
The findings were published in the journal PLOS ONE.
19th Mar 2014, 02:06 AM #902
Re: Health Bulletin
Now, a software to calculate risk of heart disease
Researchers from a Spanish university have developed a new computer software to diagnose cardiovascular risk on the basis of an eye scan.
Doctors from Valenica University have started studying the blood vessel network around the retina of low-birth weight babies. They scan the fundus of the retina to diagnose whether the child will develop hypertension or heart diseases in adult age.
"We want to know the caliber and the branching angle of the retinal vessels because that information helps us to understand how the blood is circulating,'' said Empar Lurbe, head of the paediatrics unit of the university hospital. The measurement of the branching angles and the characteristics of the vessels' caliber -if they are wider or narrower or if the branching angle is bigger or smaller- tells if the child who has a different branching angle could have an increase in blood pressure over the years.
Lurbe said children with fetuses with growth retardation are those who are at a greater risk of developing cardiovascular diseases, such as hypertension or type 2 diabetes. Because of this, we are using the measurements to see if the branching angles of the vessels of children who have intrauterine growth retardation are different than those who do not," the doctor added.
19th Mar 2014, 04:06 AM #903
Re: Health Bulletin
Eating a diet low in nutrients can extend lifespan
Consuming a diet very low in nutrients can extend lifespan in laboratory animals, says a theory published in BioEssays journal.
It has been known for some time that severely restricted food intake reduces the incidence of diseases of old age such as cancer. "This effect has been demonstrated in laboratories around the world, in species ranging from yeast to flies to mice," said lead author, Dr Margo Adler, an evolutionary biologist at the University of New South Wales, Australia.
The new theory is that this effect evolved to help animals continue to reproduce when food is scarce; they require less food to survive because stored nutrients in the cells can be recycled and reused.
It is this effect that could account for the increased lifespan of laboratory animals on very low-nutrient diets, because increased cellular recycling reduces deterioration and the risk of cancer.
"This is the most intriguing aspect, from a human health stand point. Although extended lifespan may simply be a side-effect of dietary restriction, a better understanding of these cellular recycling mechanisms that drive the effect may hold the promise of longer, healthier lives for humans," she said.
19th Mar 2014, 04:14 PM #904
Re: Health Bulletin
Lack of sleep causes loss of brain cells: Study
A new study has shown disturbing evidence that chronic sleep loss causes irreversible physical damage to and loss of brain cells.
Extended wakefulness — fast becoming common among humans, has now been inked to injury to, and loss of, the locus coeruleus (LC) neurons that are essential for alertness and optimal cognition.
This is the first study that confirms that sleep loss can actually result in a loss of neurons.
The study also trashes common wisdom that catch up sleep repays one's sleep debt, with no lasting effects.
Using a mouse model with of chronic sleep loss, Sigrid Veasey, associate professor of medicine at the Perelman School of Medicine and collaborators from Peking University have showed permanent loss of brain cells.
In mice, prolonged lack of sleep led to 25% of certain brain cells dying.
Most people appreciate that not getting enough sleep impairs cognitive performance.
For the chronically sleep-deprived such as shift workers, students, or truckers, a common strategy is simply to catch up on missed slumber on the weekends.
But this new Penn Medicine study confirms that lack of sleep may be more serious than previously thought.
Veasay said "In general, we've always assumed full recovery of cognition following short-and long-term sleep loss. But some of the research in humans has shown that attention span and several other aspects of cognition may not normalize even with three days of recovery sleep, raising the question of lasting injury in the brain. We wanted to figure out exactly whether chronic sleep loss injures neurons, whether the injury is reversible and which neurons are involved."
Mice were examined following periods of normal rest, short wakefulness or extended wakefulness, modelling a shift worker's typical sleep pattern.
The lab found that in response to short-term sleep loss, LC neurons up regulate the sirtuin type 3 (SirT3) protein, which is important for mitochondrial energy production and redox responses, and protect the neurons from metabolic injury.
SirT3 is essential across short-term sleep loss to maintain metabolic homeostasis, but in extended wakefulness, the SirT3 response is missing.
After several days of shift worker sleep patterns, LC neurons in the mice began to display reduced SirT3, increased cell death, and the mice lost 25% of these neurons.
The team now plans to examine shift workers post-mortem for evidence of increased LC neuron loss and signs of neurodegenerative disorders such as Alzheimer's and Parkinson's, since some previous mouse models have shown that lesions or injury to LC neurons can accelerate the course of those diseases.
While not directly causing these diseases, "injuring LC neurons due to sleep loss could potentially facilitate or accelerate neuro-degeneration in individuals who already have these disorders," Veasey says.
Recently frequent fliers, night shift workers and youngsters with a compulsive habit of staying up at night were told that irregular bed time hours and lack of sleep causes "profound disruption" to more than 1,000 genes, including those responsible with maintaining, repairing and protecting our body.
The study, conducted by sleep and systems biology researchers from the University of Surrey, has found that the daily rhythms of many genes are disrupted when sleep times shift.
19th Mar 2014, 09:42 PM #905
Re: Health Bulletin
Why dark chocolate is good for you
Gobbling chocolates has been a strict no, thanks to the calories they contain.
Strangely, the health benefits of eating dark chocolate have been extolled for centuries, but the exact reason has remained a mystery, until now.
Researchers have finally found that bacteria in the human stomach gobble dark chocolate and ferment it into anti-inflammatory compounds that are good for the heart.
When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke.
The team tested three cocoa powders using a model digestive tract, composed of a series of modified test tubes, to simulate normal digestion.
They then subjected the non-digestible materials to anaerobic fermentation using human fecal bacteria.
Cocoa powder, an ingredient in chocolate, contains several polyphenol or antioxidant, compounds such as catechin and epicatechin and a small amount of dietary fibre.
Both components are poorly digested and absorbed, but when they reach the colon, the desirable microbes take over.
"We found that there are two kinds of microbes in the gut: the good ones and the bad ones. The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate. When you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory. The other bacteria in the gut are associated with inflammation and can cause gas, bloating, diarrhoea and constipation. These include some Clostridia and some E coli," explained Maria Moore.
John Finley, who led the work said that this study is the first to look at the effects of dark chocolate on the various types of bacteria in the stomach.
The researchers are with Louisiana State University.
"In our study we found that the fibre is fermented and the large polyphenolic polymers are metabolized to smaller molecules, which are more easily absorbed. These smaller polymers exhibit anti-inflammatory activity," Finley said.
Finley also noted that combining the fibre in cocoa with prebiotics is likely to improve a person's overall health and help convert polyphenolics in the stomach into anti-inflammatory compounds.
"When you ingest prebiotics, the beneficial gut microbial population increases and outnumbers any undesirable microbes in the gut, like those that cause stomach problems,"he added.
Finley said that people could experience even more health benefits when dark chocolate is combined with solid fruits like pomegranates and acai. Looking to the future, he said that the next step would be for industry to do just that.
20th Mar 2014, 01:30 AM #906
Re: Health Bulletin
New method boon for kidney stone treatment
Modern fast paced lifestyle is leading to rising incidence of kidney stones in the world. Giving new hope to kidney stone patients engineers from Duke University in Durham have devised a way to improve the efficiency of lithotripsy .Lithotripsy is the medical procedure of demolishing kidney stones using focused shock waves.
The engineers after intensive research devised that all it took was cutting a groove near the perimeter of the shock wave-focusing lens and changing its curvature,
“We’ve developed a simple, cost-effective and reliable solution that can be quickly implemented on their machines,” said Pei Zhong, professor of mechanical engineering and materials science at Duke University.
In laboratory tests, the researchers sent shock waves through a tank of water and used a fiber optic pressure sensor to ensure the shock wave was focusing on target.
They broke apart synthetic stones in a model human kidney and in anesthesised pigs and used a high-speed camera to watch the distribution of cavitation bubbles forming and collapsing - a process that happens too fast for the human eye to see.
During the past two decades, lithotripter manufacturers introduced multiple changes to their machines, but they couldn't improve effectiveness of kidney stone treatment.
While the current commercial version reduced 54 percent of the stones into fragments less than two millimeters in diameter, the new version pulverised 89 percent of the stones while also reducing the amount of damage to surrounding tissue.
20th Mar 2014, 01:31 AM #907
Re: Health Bulletin
Vitamin D supplements may not reduce depression: Study
Researchers have suggested that Vitamin D supplements may not be able to decrease depression.
The review, by Jonathan A. Shaffer, PhD, assistant professor of medical sciences at Columbia University Medical Center (CUMC), and team at CUMC's Center for Cardiovascular Behavioral Health, found that only seven trials with a total of approximately 3200 participants compared the effect of vitamin D supplementation on depression with no vitamin D supplementation.
Nearly all of these trials were characterized by methodological limitations, and all but two involved participants without clinically significant depression at the start of the study. The overall improvement in depression across all trials was small and not clinically meaningful.
However, additional analyses of the clinical data by Dr. Schaffer hinted that vitamin D supplements may help patients with clinically significant depression, particularly when combined with traditional antidepressant medication. New well-designed trials that test the effect of vitamin D supplements in these patients are needed to determine if there is any clinical benefit.
The authors note that supplementation with vitamin D also may be effective only for those with vitamin D deficiency. They also recommend that future studies consider how vitamin D dosing and mode of delivery contribute to its effects on depression .
The study has been published online in the journal Psychosomatic Medicine.
20th Mar 2014, 06:24 PM #908
Re: Health Bulletin
Saturated fat does not cause heart disease: Study
A dollop of ghee or butter in your diet does not cause as much harm to your heart as it was believed till now.
Researchers from the University of Cambridge and the British Heart Foundation have found there is actually no evidence that confirms changing the type of fat you eat from "bad" saturated to "healthier" polyunsaturated cuts heart risk.
The researchers analysed data from 72 unique studies with over 600,000 participants from 18 nations and found total saturated fatty acid, whether measured in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk in the observational studies.
Similarly, when analysing the studies that involved assessments of the consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, there were no significant associations between consumption and cardiovascular risk.
Saturated fat is the kind of fat found in butter, biscuits, red meat, sausages and bacon and cheese and cream. There has been a big drive to get more people eating unsaturated fats, such as olive and sunflower oils, and other non-animal fats instead.
But the latest study raises questions about the current guidelines that generally restrict the consumption of saturated fats and encourage consumption of polyunsaturated fats to prevent heart disease.
"These are interesting results that potentially stimulate new lines of scientific inquiry and encourage careful reappraisal of our current nutritional guidelines," said Dr Rajiv Chowdhury, lead author of the research at the University of Cambridge. "Cardiovascular disease, in which the principal manifestation is coronary heart disease, remains the single leading cause of death and disability worldwide. In 2008, more than 17 million people died from a cardiovascular cause globally. With so many affected by this illness, it is critical to have appropriate prevention guidelines which are informed by the best available scientific evidence."
The research collaboration led by the University of Cambridge analysed existing cohort studies and randomised trials on coronary risk and fatty acid intake. They showed that current evidence does not support guidelines which restrict the consumption of saturated fats in order to prevent heart disease.
The researchers also found insufficient support for guidelines which advocate the high consumption of polyunsaturated fats (such as omega 3 and omega 6) to reduce the risk of coronary disease.
Furthermore, when specific fatty acid subtypes (such as different types of omega 3) were examined, the effects of the fatty acids on cardiovascular risk varied even within the same broad family — questioning the existing dietary guidelines that focus principally on the total amount of fat from saturated or unsaturated rather than the food sources of the fatty acid subtypes.
Within saturated fatty acid, the researchers found weak positive associations between circulating palmitic and stearic acids (found largely in palm oil and animal fats, respectively) and cardiovascular disease, whereas circulating margaric acid (a dairy fat) significantly reduced the risk of cardiovascular disease.
Additionally, when the authors investigated the effects of omega-3 and omega-6 fatty acid supplementations on reducing coronary disease in the randomised controlled trials, they did not find any significant effects — indicating a lack of benefit from these nutrients.
"This analysis of existing data suggests there isn't enough evidence to say that a diet rich in polyunsaturated fats but low in saturated fats reduces the risk of cardiovascular disease," said Professor Jeremy Pearson from the British Heart Foundation, which helped fund the study. "But large-scale clinical studies are needed, as these researchers recommend, before making a conclusive judgement. Alongside taking any necessary medication, the best way to stay heart healthy is to stop smoking, stay active and ensure our whole diet is healthy — and this means considering not only the fats in our diet but also our intake of salt, sugar and fruit and vegetables."
20th Mar 2014, 06:25 PM #909
Re: Health Bulletin
Engineered tissue closely mimics natural heart muscle that beats
Heart muscles that actually beat, created artificially in the lab, have for the first time become a reality.
In a major breakthrough that could repair millions of human hearts damaged after a massive heart attack, scientists have for the first time successfully implanted artificial heart tissue that actually beat in animals.
Researchers at the Brigham and Women's Hospital and Harvard Medical School in Boston and the University of Sydney in Australia have been able to combine a novel elastic hydrogel with micro scale technologies to create an artificial cardiac tissue that mimics the mechanical and biological properties of the native heart.
"Our hearts are more than just a pile of cells," said Ali Khademhosseini from Harvard Medical School. "They're very organized in their architecture".
To tackle the challenge of engineering heart muscle, Khademhosseini and Annabi have been working with natural proteins that form gelatin-like materials called hydrogels.
"The reason we like these materials is because in many ways they mimic aspects of our own body's matrix," Khademhosseini said. They're soft and contain a lot of water, like many human tissues.
His group has found that they can tune these hydrogels to have the chemical, biological, mechanical and electrical properties they want for the regeneration of various tissues in the body. But there was one way in which the materials didn't resemble human tissue.
Like gelatin, early versions of the hydrogels would fall apart, whereas human hearts are elastic. The elasticity of the heart tissue plays a key role for the proper function of heart muscles such as contractile activity during beating.
So, the researchers developed a new family of gels using a stretchy human protein aptly called tropoelastin. That did the trick, giving the materials much needed resilience and strength.
But building tissue is not just about developing the right materials. Making the right hydrogels is only the first step. They serve as the tissue scaffold. On it, the researchers grow actual heart cells.
To make sure the cells form the right structure, Khademhosseini's lab uses 3-D printing and micro engineering techniques to create patterns in the gels. These patterns coax the cells to grow the way the researchers want them to.
20th Mar 2014, 06:25 PM #910
Re: Health Bulletin
Humans may have two distinct cognitive systems
Scientists have found the strongest evidence yet that humans have separate and distinct cognitive systems with which they can categorize, classify and conceptualize their world.
The question of whether humans have discrete cognitive systems operating on different levels has been debated for years.
"This issue of whether there are separate cognitive systems famously arose regarding humans' declarative and procedural memory and in the field of categorisation," said lead researcher, cognitive psychologist J David Smith, of the University at Buffalo.
"Cognitive neuroscientists have hypothesised that humans have distinguishable systems for categorising the objects in their world - one more explicit (i.e, conscious and available to introspection), one less so, or more implicit," said Smith.
To grasp the differences between these two types of learning, Smith recommends that we remember certain distinctions in our performance of the tasks of daily life.
"For instance, when you select a cereal named 'Chocoholic' from the store shelf consider why you are doing so," Smith said.
"Is it a deliberate, explicit choice, or is it possibly an implicit-procedural chocolate reaction, one triggered by processes, memories and so on, of which you are generally unaware?" he said.
"Because of the considerable controversy surrounding the question of whether we have more than one cognitive system, researchers have continued to seek models that distinguish the processes of explicit and implicit category learning and this study presents the clearest distinction yet found between these systems," he said.
In the study, researchers asked participants to work for blocks of trials without any corrective feedback, and then deliver feedback when they were finished.
Smith likened this process to an undergraduate testing situation in which the student taking a test does not get item-by-item feedback, but receives a summary score once the test is completed.
Because this manipulation prevents the formation of automatic (implicit) stimulus-response associations, Smith and his colleagues hypothesised that it would undermine the processes of conditioning and eliminate the possibility of implicit category learning.
Researchers found that facing a task that could only be learned implicitly, participants with blocked feedback turned futilely to conscious strategies that were inadequate, because this was all they could do when implicit category learning was defeated.
"In the area of categorisation research the issue of single vs multiple systems is nearly closed," Smith said.
"The evidence is now very strong that there are multiple category-learning systems - in particular, the explicit-conscious and the implicit-procedural system," he said.
The study was published in the journal Psychological Science.