Research news in brief

One-handed people point way to new brain theory

In people born with one hand, the brain region that would normally light up with that missing hand’s activity lights up instead with the activity of other body parts — including the arm, foot, and mouth — that fill in for the hand’s lost function, according to an international study published in Current Biology. Scientists from Israel and the UK say that the discovery could change fundamental understanding of how the brain is organised. The researchers studied 17 people who lacked a hand from birth along with 24 matched, two-handed controls. Each participant was video recorded while completing five everyday tasks, such as wrapping a present or handling money, to see how they went about it. Participants were also asked to move various parts of their bodies while their brains were scanned using functional magnetic resonance imaging. “We found that the traditional hand area gets used up by a multitude of body parts in congenital one-handers,” said researcher Tamar Makin, from University College London. “Interestingly, these body parts that get to benefit from increased representation in the freed-up brain territory are those used by the one-handers in daily life to substitute for their missing-hand function — say when having to open a bottle of water. In intact participants, all this is carried by the non-dominant hand,” she continued. “But the fact that we see such a strikingly different representation in that area in congenital one-handers may suggest that this is not actually the hand area. If true, this means we’ve been misinterpreting brain organisation based on body part, rather than based on function. The implications, if this interpretation is correct, are massive.” Her hope is to find a way to encourage the brain to represent and control artificial body parts, such as a prosthetic arm, using the brain area that would have controlled the missing hand.

Australian ad linking alcohol with cancer is a winner

Australian-led research published in BMJ Open has found that the effectiveness of alcohol harm reduction campaigns may be improved by directly communicating alcohol’s long term harms to the general adult population of drinkers, along with drinking guidelines. Researchers from the Cancer Council Victoria, Curtin University and Ohio State University in the US, randomly assigned 2174 Australian adult weekly drinkers to view three of 83 English-language alcohol harm reduction ads. Each ad was viewed and rated by a mean of 79 participants. After viewing each ad, participants reported the extent to which they felt motivated to reduce their drinking. Ads were ranked from most to least motivating using predicted means adjusted for demographic characteristics and alcohol consumption. They then compared the characteristics of the top-ranked 15% of ads (most motivating) with the middle 70% and bottom 15%. An Australian ad about the link between alcohol and cancer (“Spread”) was most motivating, whereas an ad that encouraged drinking water instead of beer (“Add nothing”) was least motivating. Top-ranked ads were more likely than other ads to feature a “why change” message and less likely to carry a “how to change” message, more likely to address long term harms, more likely to be aimed at the general adult drinking population and more likely to include drinking guidelines. There was substantial overlap in top-ranked ads for younger versus older adults, men versus women and high-risk versus low-risk drinker subgroups. With a mean score of 3.77, the highest ranked ad was “Spread”, developed and funded by the Western Australian state government as part of their Alcohol and cancer mass media campaign. The second most effective ad — “What you can’t see” (mean score of 3.62) — was from the same Western Australian campaign. The authors acknowledge that further research is needed to determine whether the motivation measure predicts subsequent reduced alcohol consumption.

Steroids no quick fix for sore throat

In patients with a sore throat that didn’t require immediate antibiotics, a single capsule of the corticosteroid dexamethasone did not increase the likelihood of complete symptom resolution after 24 hours, and although more patients taking the steroid reported feeling completely better after 48 hours, a role for steroids to treat sore throats in primary care was uncertain, according to a British study published in JAMA. The researchers randomly assigned adults with sore throat not requiring immediate antibiotics to a single oral dose of 10 mg of dexamethasone or placebo. Of the 565 eligible randomised participants (median age of 34 years), 288 received dexamethasone and 277 placebo. The primary outcome of the study was the proportion of participants experiencing complete resolution of symptoms at 24 hours. However, the researchers found that at 24 hours, participants receiving dexamethasone were not more likely than those receiving placebo to have complete symptom resolution. Results were similar among those who were not offered an antibiotic prescription and those who were offered a delayed antibiotic prescription. However, at 48 hours, more participants receiving dexamethasone than placebo (35% v 27%) had complete symptom resolution, which was also observed in patients not offered delayed antibiotics. There were no significant differences in other outcomes such as days missed from work or school and adverse events. The authors commented that there remained uncertainty about the role of oral corticosteroids for patients presenting in primary care with sore throat, but that there may be some clinical benefit.

High-fat, high-carb diet a cause of osteoarthritis

Researchers from the Queensland University of Technology have found that saturated fat changed the composition of cartilage, particularly in the weight-bearing joints of the hip and knee, making it a prime suspect in the onset of osteoarthritis in rats. In a study published in Scientific Reports, the researchers studied the effects on joints of diets rich in a variety of saturated fatty acids. “We found that a diet containing simple carbohydrates together with 20% saturated fats produced osteoarthritic-like changes in the knee,” said Professor Yin Xiao. “Saturated fatty acid deposits in the cartilage change its metabolism and weaken the cartilage, making it more prone to damage. This would, in turn, lead to osteoarthritic pain from the loss of the cushioning effect of cartilage. We also found changes in the bone under the cartilage on a diet rich in saturated fat.” The team tested lauric acid, a saturated fatty acid found in coconut oil, and found that when lauric acid replaced the meat fat in the rats’ diet there were decreased signs of cartilage deterioration and metabolic syndrome, in an apparent protective effect.

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