Research round-up for the week of February 27, 2012

A summary of recent McGill research news: Rapid flu tests, coastal drinking water and climate change, neuron memory and chronic pain, and the brain's response to rhythm.

By McGill Reporter Staff

 How accurate are rapid flu tests?

A new study conducted by researchers from McGill University, the Research Institute of the McGill University Health Centre (RI MUHC), and Sainte-Justine University Hospital Research Centre, Montreal, has put the accuracy of rapid influenza diagnostic tests (RIDTs) under the microscope. The meta-analysis of 159 studies showed three key findings: that RIDTs can be used to confirm the flu, but not to rule it out; that test accuracy is higher in children than it is in adults; and that RIDTs are better at detecting the more common influenza A virus than they are at detecting influenza B.

The research, led by by Dr. Caroline Chartrand, Sainte-Justine Hospital staff pediatrician and researcher, was published this week in the Annals of Internal Medicine.

What do the study results mean for patient care? “Our results suggest a case for routine implementation of these tests at the point-of-care, especially among children, during flu season,” explained Dr. Chartrand, who was a McGill master’s student when she conducted the research. “It would have to be shown in clinical practice, but the routine use of these tests could mean significant improvements in patient care, especially children. For example, if you know your patient has the flu, you might not need to run other tests. Maybe you’d be able to prescribe antiviral medication earlier. And perhaps flu patients would be triaged differently and sent home more quickly, which is great news for high-traffic emergency rooms and clinics during the flu season. But it is important to note that rapid flu tests can be falsely negative and therefore should not be used to rule out flu.”

 Coastal drinking water more vulnerable to water use than climate change

Human activity is probably a greater threat to the coastal groundwater needed for drinking water supplies than are the rising sea levels that result from climate change, according to a study conducted by geoscientists from McGill University and the University of Saskatchewan. Tom Gleeson from McGill’s Department of Civil Engineering worked with Grant Ferguson from the University of Saskatchewan’s Department of Civil and Geological Engineering to examine data from more than 1,400 coastal watersheds. They discovered that with the exception of very flat coastal areas that can be inundated with sea water – rare in North America – most coastal aquifers (underground layers of rock or sand that yield water) are relatively unaffected by rising sea levels. But what does appear to affect these aquifers is humans pumping water from wells for drinking, domestic use and irrigation. “Coastal aquifers are very vulnerable to increased water demand so we have real policy opportunities,” Gleeson says. “We can reduce consumption of groundwater in coastal areas or manage groundwater use wisely.” The study was published online February 19 in Nature Climate Change.

Neuron memory key to taming chronic pain

A team of researchers led by McGill neuroscientist Terence Coderre, who is also affiliated with the Research Institute of the McGill University Health Centre, has found the key to understanding how memories of pain are stored in the brain. More importantly, the researchers are also able to suggest how these memories can be erased, making it possible to ease chronic pain. Recent work has shown that the protein kinase PKMzeta plays a crucial role in building and maintaining memory by strengthening the connections between neurons. Now Coderre and his colleagues have discovered that PKMzeta is also the key to understanding how the memory of pain is stored in the neurons. In a study that was recently published in Molecular Pain, they were able to show that after painful stimulation, the level of PKMzeta increases persistently in the central nervous system (CNS). Coderre and his colleagues believe that building on this study to devise ways to target PKMzeta in pain pathways could have a significant effect for patients with chronic pain.

 Researchers uncover mathematical formula for rhythm and suggest our brains may be hardwired to respond to it

Whether it’s Bach or Brubeck, a new study shows that composers repeat rhythmic patterns in their works in such a way that the part is a copy of the larger whole. A research team led by neuroscientists Drs. Daniel Levitin and Vinod Menon, from McGill and Stanford Universities, respectively, analyzed the scores of close to 2,000 musical compositions written by more than 40 composers over the last 400 years in a large variety of Western musical genres. They discovered a mathematical formula governing the rhythmic patterns to which every single piece of music conformed. The researchers found that all the musical compositions they studied shared the same “fractal” quality, where the part is a more limited repetition of the whole. That is the larger temporal structure of well-formed musical pieces is composed of repeating motifs of their own short-term temporal structure. At the same time, researchers also discovered that each composer had his or her own highly individual rhythmic signature. “Mozart’s notated rhythms were the least predictable, Beethoven’s were the most, and Monteverdi and Joplin had nearly identical, overlapping rhythm distributions. But they each have their own distinctive rhythmic signature that you can capture,” says Levitin. “Our findings also suggest that rhythm may play an even greater role than pitch in conveying a composer’s distinctive style.” The study was published in a recent edition of the Proceedings of the National Academy of Sciences (PNAS).