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Of course a nice glass of wine goes well with a hearty steak, and now researchers who study the way food feels in our mouths think they may understand why that is: The astringent wine and fatty meat are like the yin and yang of the food world, sitting on opposite ends of a sensory spectrum.
The findings, reported in the October 9th issue of Current Biology, a Cell Press publication, offer a whole new definition of the balanced meal. They also offer a new way of thinking about our eating habits, both good and bad.
'The mouth is a magnificently sensitive somatosensory organ, arguably the most sensitive in the body,' said Paul Breslin of Rutgers University and the Monell Chemical Senses Center. 'The way foods make our mouths feel has a great deal to do with what foods we choose to eat.'
It might explain the appeal of salad dressings, with their characteristic acids and oils, for example. Think also of the pink folds of ginger on the sides of our sushi plates or the soda with our burgers and fries.
The researchers knew that astringent wines feel rough and dry in our mouths. Fats, on the other hand, are slippery. There was the notion that the two might oppose each other, but it wasn't quite clear how that might really work. After all, the astringents we consume are only weakly astringent.
Breslin, Catherine Peyrot des Gachons, and colleagues now show that weakly astringent brews - in this case containing grape seed extract, a green tea ingredient, and aluminum sulfate - build in perceived astringency with repeated sipping. When paired with dried meat, those astringent beverages indeed counter the slippery sensation that goes with fattiness.
This natural tendency for seeking balance in our mouths might have benefits for maintaining a diversity of foods in our diet, Breslin says.
'The opposition between fatty and astringent sensations allows us to eat fatty foods more easily if we also ingest astringents with them,' he says.
As an aside, Breslin adds, fresh seeds and nuts could have a certain sort of appeal. 'These foods come both with their own fats and astringents in one package, so they may be self-balancing.'
Monday, October 22, 2012
Blocking Neuropathic Pain Before It Starts
>4.5 (2 votes)
Using tiny spheres filled with an anesthetic derived from a shellfish toxin, researchers at Boston Children's Hospital and the Massachusetts Institute of Technology have developed a way to delay the rise of neuropathic pain, a chronic form of pain that arises from flawed signals transmitted by damaged nerves.
The method could potentially allow doctors to stop the cascade of events by which tissue or nerve injuries evolve into neuropathic pain, which affects 3.75 million children and adults in the United States alone.
The researchers, led by Daniel Kohane, MD, PhD, of Boston Children's Department of Anesthesia and Robert Langer, ScD, of MIT, reported the results of animal studies online in the Proceedings of the National Academy of Sciences.
Neuropathic pain can be long lasting and debilitating. Caused by shingles, nerve trauma, cancer and other conditions, it arises because damaged nerves send unusual signals to the spinal cord and the brain. The constant signaling effectively reprograms the central nervous system to react to any stimulus to the affected area, or even no stimulus at all, by triggering unpleasant sensations ranging from tingling and numbness to shooting, burning pain.
'Currently neuropathic pain is treated with systemic medications, but there has been significant interest in using powerful local anesthetics to block aberrant nerve discharges from the site of injury to prevent the onset of neuropathic pain,' said Kohane. 'Others have tried with varying degrees of success to do this in animal models using a variety of methods, but if applied clinically, those methods would require surgical intervention or could be toxic to tissues. We want to avoid both of those concerns.'
The team's method combines saxitoxin, a powerful local anesthetic, and dexamethasone, which prolongs saxitoxin's effects. The two are packaged in liposomes - lipid spheres about 5.5 micrometers wide, or a bit smaller than a red blood cell - for nontoxic delivery to the site of nerve or tissue damage.
To assess whether the anesthetic-loaded liposomes (called SDLs for saxitoxin dexamethasone liposomes) might work as a potential treatment for neuropathic pain, Kohane and Langer - along with Sahadev Shankarappa, MBBS, MPH, PhD (a fellow in the Kohane lab) and others - attempted to use them to block the development of signs of neuropathy in an animal model of sciatic nerve injury. They found that a single injection of SDLs had a very mild effect, delaying the onset of neuropathic pain by about two days compared to no treatment. Three injections of SDLs at the site of injury over the course of 12 days, however, delayed the onset of pain by about a month.
The signal blockade mounted by the SDLs also appeared to prevent reprogramming of the central nervous system. The team noted that astrocytes in the spine, which help maintain the pain signaling in neuropathic patients, showed no signs of pain-related activation five and 60 days after injury in animals treated with SDLs.
'Ultimately we'd like to develop a way to reversibly block nerve signaling for a month with a single injection without causing additional nerve damage,' Kohane explained. 'For the moment, we're trying to refine our methods so that we can get individual injections to last longer and figure out how to generalize the method to other models of neuropathic pain.
'We also need to see whether it is safe to block nerve activity in this way for this long,' he continued. 'We don't want to inadvertently trade one problem for another. But we think that this approach could be fruitful for preventing and treating what is really a horrible condition.'
Using tiny spheres filled with an anesthetic derived from a shellfish toxin, researchers at Boston Children's Hospital and the Massachusetts Institute of Technology have developed a way to delay the rise of neuropathic pain, a chronic form of pain that arises from flawed signals transmitted by damaged nerves.
The method could potentially allow doctors to stop the cascade of events by which tissue or nerve injuries evolve into neuropathic pain, which affects 3.75 million children and adults in the United States alone.
The researchers, led by Daniel Kohane, MD, PhD, of Boston Children's Department of Anesthesia and Robert Langer, ScD, of MIT, reported the results of animal studies online in the Proceedings of the National Academy of Sciences.
Neuropathic pain can be long lasting and debilitating. Caused by shingles, nerve trauma, cancer and other conditions, it arises because damaged nerves send unusual signals to the spinal cord and the brain. The constant signaling effectively reprograms the central nervous system to react to any stimulus to the affected area, or even no stimulus at all, by triggering unpleasant sensations ranging from tingling and numbness to shooting, burning pain.
'Currently neuropathic pain is treated with systemic medications, but there has been significant interest in using powerful local anesthetics to block aberrant nerve discharges from the site of injury to prevent the onset of neuropathic pain,' said Kohane. 'Others have tried with varying degrees of success to do this in animal models using a variety of methods, but if applied clinically, those methods would require surgical intervention or could be toxic to tissues. We want to avoid both of those concerns.'
The team's method combines saxitoxin, a powerful local anesthetic, and dexamethasone, which prolongs saxitoxin's effects. The two are packaged in liposomes - lipid spheres about 5.5 micrometers wide, or a bit smaller than a red blood cell - for nontoxic delivery to the site of nerve or tissue damage.
To assess whether the anesthetic-loaded liposomes (called SDLs for saxitoxin dexamethasone liposomes) might work as a potential treatment for neuropathic pain, Kohane and Langer - along with Sahadev Shankarappa, MBBS, MPH, PhD (a fellow in the Kohane lab) and others - attempted to use them to block the development of signs of neuropathy in an animal model of sciatic nerve injury. They found that a single injection of SDLs had a very mild effect, delaying the onset of neuropathic pain by about two days compared to no treatment. Three injections of SDLs at the site of injury over the course of 12 days, however, delayed the onset of pain by about a month.
The signal blockade mounted by the SDLs also appeared to prevent reprogramming of the central nervous system. The team noted that astrocytes in the spine, which help maintain the pain signaling in neuropathic patients, showed no signs of pain-related activation five and 60 days after injury in animals treated with SDLs.
'Ultimately we'd like to develop a way to reversibly block nerve signaling for a month with a single injection without causing additional nerve damage,' Kohane explained. 'For the moment, we're trying to refine our methods so that we can get individual injections to last longer and figure out how to generalize the method to other models of neuropathic pain.
'We also need to see whether it is safe to block nerve activity in this way for this long,' he continued. 'We don't want to inadvertently trade one problem for another. But we think that this approach could be fruitful for preventing and treating what is really a horrible condition.'
Wednesday, October 10, 2012
Does Reality Blend With Fiction When Making Decisions In Video Games?
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With a moral theme increasingly running through today's popular video games, scientists questioned whether moral decisions made by the players resulted from feelings of guilt, and whether immoral actions, including violence and theft, affected the enjoyment of the game.
There have been several studies analyzing the effects of video games, due to the great controversy these games have created. One study from 2011 indicated that teen aggression is increased by playing violent games.
Some scientists have suggested that how each player perceives characters and events within a game might be an important factor in determining the decisions they need to make for certain actions in a scene.
This study, in Cyberpsychology, Behavior, and Social Networking, observed whether ethical decisions are made because the characters are considered as real people to the individual player, and whether these choices are made to avoid a guilty conscious.
In order to identify the impact these decisions have on emotional reactions to the games, 75 volunteers aged 18 to 24 who reported an average of 7.5 hours per week spent on playing video games were asked to fill out the Moral Foundations Questionnaire (MFQ) to measure their different ideas on morality.
Participants played the game Fallout 3 on Xbox 360, and then were asked to fill out another questionnaire, regarding their reactions to the game and the moral choices they made.
The MFQ was able to predict individual differences in decision making. Results showed that most of the subjects thought of the characters as real, and any interactions made with them were interpreted as actual interpersonal interactions, which, in turn, caused them to make ethical choices.
Although behaving antisocially was found to have no effect on enjoyment, it did increase the player's guilt.
Brenda K. Wiederhold, PhD, MBA, BCIA, Editor-in-Chief of Cyberpsychology, Behavior, and Social Networking, from the Interactive Media Institute, San Diego, CA, concluded:
'Although preliminary, these results point to the utility of games as teaching and educational tools, as well as important tools for the assessment of behavior. These findings indicate how real the virtual world can become when one suspends disbelief and immerses oneself in the scenario.'
Previous research has shown that game players bring the virtual world into real life, indicating that teens who play mature-rated risk-glorifying games have a higher risk of becoming reckless drivers.
With a moral theme increasingly running through today's popular video games, scientists questioned whether moral decisions made by the players resulted from feelings of guilt, and whether immoral actions, including violence and theft, affected the enjoyment of the game.
There have been several studies analyzing the effects of video games, due to the great controversy these games have created. One study from 2011 indicated that teen aggression is increased by playing violent games.
Some scientists have suggested that how each player perceives characters and events within a game might be an important factor in determining the decisions they need to make for certain actions in a scene.
This study, in Cyberpsychology, Behavior, and Social Networking, observed whether ethical decisions are made because the characters are considered as real people to the individual player, and whether these choices are made to avoid a guilty conscious.
In order to identify the impact these decisions have on emotional reactions to the games, 75 volunteers aged 18 to 24 who reported an average of 7.5 hours per week spent on playing video games were asked to fill out the Moral Foundations Questionnaire (MFQ) to measure their different ideas on morality.
Participants played the game Fallout 3 on Xbox 360, and then were asked to fill out another questionnaire, regarding their reactions to the game and the moral choices they made.
The MFQ was able to predict individual differences in decision making. Results showed that most of the subjects thought of the characters as real, and any interactions made with them were interpreted as actual interpersonal interactions, which, in turn, caused them to make ethical choices.
Although behaving antisocially was found to have no effect on enjoyment, it did increase the player's guilt.
Brenda K. Wiederhold, PhD, MBA, BCIA, Editor-in-Chief of Cyberpsychology, Behavior, and Social Networking, from the Interactive Media Institute, San Diego, CA, concluded:
'Although preliminary, these results point to the utility of games as teaching and educational tools, as well as important tools for the assessment of behavior. These findings indicate how real the virtual world can become when one suspends disbelief and immerses oneself in the scenario.'
Previous research has shown that game players bring the virtual world into real life, indicating that teens who play mature-rated risk-glorifying games have a higher risk of becoming reckless drivers.
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