In Brief

May / June 2018   Comments

Viruses as intercontinental travellers

A staggering number of viruses and bacteria are being swept up into the Earth’s atmosphere each day and then dropping back down, according to a study published in the ISME Journal (a publication of the International Society for Microbial Ecology). Carried up into the air in soil dust and sea spray, they can rise to an altitude beyond the influence of weather systems and travel for thousands of kilometres before landing back on Earth.

A team of Canadian, Spanish and American scientists used platform sites high in Spain’s Sierra Nevada mountains to conduct their research. According to one of the senior authors of the study, 800 million viruses are deposited per square metre per day, or 25 viruses for each person in Canada. Nine to 461 times more viruses are deposited than bacteria.

The team’s findings help explain something that was first noticed about 20 years ago: genetically similar viruses crop up in very distant and different environments around the world. The study results show that viruses can hitch a ride on small, light, organic particles, get swept up into the atmosphere above 2,500 to 3,000 metres (where long-range transport is possible), and then drop onto another continent.

Multilingualism: Exercise for the brain

Several studies in healthy adults have shown that speaking more than one language is good for your brain. Researchers in Montreal have now demonstrated that the benefits extend to older people with Alzheimer’s disease and mild cognitive impairment, which is a risk state for the disease. Sixty-eight patients with mild cognitive impairment and 26 patients with Alzheimer’s disease participated in the research team’s study, which was published in Neuropsychologia. The investigators used data from high-resolution, whole-brain magnetic resonance imaging and sophisticated analytic techniques to measure the thickness of the cerebral cortex and grey matter density in brain areas known to be involved in language, cognition and memory.

They found that participants who spoke more than one language had thicker cortex in brain areas related to language and cognition than monolingual participants. The researchers also reported that the thicker the cortex in these areas in multilingual participants, the better the performance on memory tasks. The findings have led the investigators to hypothesize that people who know more than one language can compensate for the tissue loss that occurs with Alzheimer’s disease by processing memories in alternative ways in their brains.

A paper-based improvement in the drug discovery process

Engineers at McMaster University have invented a paper-based device that they expect will speed up the discovery of new drugs and make the process more affordable. Currently, thousands of possible drugs are screened to see if they have a chemical effect on a target molecule, and then promising candidates go through several stages of more extensive testing. The initial screening step produces many inaccurate results, mostly because candidate drugs can stick together and physically block the target molecule, triggering a positive test result. A lot of time and money are wasted on subsequently weeding out the drugs that do not chemically interact with the target molecule.

The researchers described their invention in Nature Communications. They created an inexpensive printable hydrogel, a network of polymers used in products ranging from disposable diapers to contact lenses. The thin layers of printed hydrogels in their device can form a cage around the target molecule so that candidate drugs cannot physically block the target. The device is expected to improve the accuracy of the screening step without requiring labs to significantly change how they currently screen for new drugs.

Eye movements may help the brain stitch memories together

New evidence shows that the brain uses eye movements to help people recall detailed images they have seen. Scientists at the Rotman Research Institute at Baycrest Health Sciences in Toronto asked 16 young adults to look at a set of 14 different images for a few seconds each and to remember as many details as they could. The participants were then told to mentally visualize the images within an empty rectangle projected on a screen. Their brain activity and eye movements were captured with brain scans and eye-tracking technology as they memorized and then recalled the images.

The study, published in Cerebral Cortex, showed that when the participants recalled an image, their eyes moved in the same way as when they first saw the picture and their brains showed a similar pattern of activity. The senior author suggested that our brains use the original pattern of eye movements as a blueprint for piecing together the different parts of a memory. The researchers hope their work could eventually lead to the development of a diagnostic tool that would use eye movements to alert practitioners earlier when a patient’s memory is failing.

Clues to how the body responds to inadequate blood flow

A newly discovered gene helps our body respond to inadequate blood flow by growing additional blood vessels. The findings could help improve our understanding of cardiovascular diseases that result from inadequate blood flow, such as heart disease and stroke.

A team from the University of Toronto and Harvard Medical School investigated a newly described group of genes called long non-coding RNAs, or lncRNAs. It has long been thought that the main role of RNA, or ribonucleic acid, is to transport the genetic code needed to create proteins from one part of a cell to another. But lncRNAs also have other roles, including determining what role individual cells will eventually play in an organism. In a study published in PNAS, the researchers discovered that one of the lncRNAs, called STEEL (for spliced-transcript endothelial-enriched lncRNA), sensed inadequate blood flow in microscopic blood vessels. One of the lead investigators noted that these findings could be used to develop methods to improve recovery and healing after injury caused by inadequate blood flow.

Discovery opens the door for Ebola research in more labs

The 2014 Ebola outbreak in West Africa was responsible for 11,000 deaths and triggered a huge international effort to contain the spread of the disease. Only a few labs in the world are currently equipped to work with the Ebola virus, because such research requires extreme biosafety measures. This situation is about to change, thanks to a new study by scientists at the University of Alberta. Their discovery will give researchers a tool to study inhibitors of the Ebola virus in any lab environment.

In an article published in Scientific Reports, the Alberta research team reports they have expressed, purified and biochemically characterized a polymerase (enzyme) complex that propagates the Ebola virus. They have also developed a lab test to show that the polymerase is active. In addition to being useful for research into better treatments for infections with Ebola and related viruses, the discovery should help scientists find new medicines for other viral infections that do not currently have effective treatments, such as measles, mumps and influenza.

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