Research news in brief

Australians living longer than British and Americans

Australians are living longer, with women living to around 85.5 years, while men are living to 81.5 years, according to research from the United States published in The BMJ. The study looked at life expectancy in 18 high income countries including Australia. Australia made life expectancy gains from 2010 all the way through to 2016, while most countries saw a dip in 2014–15, which the authors said was likely related to a particularly severe influenza season, as well as pneumonia, respiratory disease, cardiovascular disease, Alzheimer’s disease and other mental disorders. While other countries bounced back, life expectancy in the US and the UK continued to decline in 2016, which the researchers said raised questions about future trends in these countries. A second study, also published in The BMJ showed an increase in US death rates in the population aged 25–64 years involving all major racial groups, and cited a broad range of conditions as potential causes, including the opioid crisis. Although drug overdoses, suicides and alcoholism were the leading cause of US excess deaths, mortality rates also increased dramatically for organ diseases involving the heart, lung and other body systems. “The opioid epidemic is the tip of an iceberg,” said the authors. In a linked editorial, Domantas Jasilionis of the Max Planck Institute for Demographic Research in Germany said life expectancy was a key characteristic of human development and declines should be taken seriously. Historical evidence suggested that discontinuities in secular trends could lead to prolonged health crises — they are warning signs of fundamental and long-standing societal and health problems.

Men pick up motion faster than women

On average, men pick up on visual motion significantly faster than women do, according to US research published in Current Biology. Individuals representing both sexes are good at reporting whether black and white bars on a screen are moving to the left or to the right – needing only a tenth of a second and often much less to make the right call, the researchers found. But, in comparison to men, women regularly took about 25–75% longer. The researchers said that the faster perception of motion by males may not necessarily reflect better visual processing. They noted that similar performance enhancements in the same task have been observed in individuals diagnosed with autism spectrum disorder (ASD) or depression and in older individuals. The authors speculated that processes in the brain that down-regulate neural activity were disrupted in these conditions and may also be weaker in males. The authors said that the finding was “entirely serendipitous”. They were using the visual motion task to study processing differences in individuals with ASD. ASD shows a large sex bias, with boys being about four times more likely to be diagnosed with the condition than girls. As a result, the researchers included sex as a factor in their analysis of control individuals in the study who didn’t have ASD. The sex difference in visual perception of motion became immediately apparent. To confirm the findings, the researchers asked other investigators who had used the same task in their own experiments for additional data representing larger numbers of study participants. And those independent data showed the same pattern of sex difference. The authors reported that the observed sex difference in visual perception can’t be explained by general differences in the speed of visual processing, overall visual discrimination abilities, or potential motor-related differences. The differences aren’t apparent in functional magnetic resonance imaging scans of the brain either. Overall, they wrote, the results showed how sex differences can manifest unexpectedly. They also highlighted the importance of including sex as a factor in the design and analysis of perceptual and cognitive studies.

Hope for low allergy breads

Researchers from Murdoch University in Perth have shed light on a promising development for people with wheat allergies. The international team examined proteins with a proven relationship to coeliac disease, occupational asthma (baker’s asthma) or wheat-dependent exercise-induced anaphylaxis (WDEIA). The work is the first step in breeding low allergy wheat varieties, according to lead author Dr Angéla Juhász. “Understanding the genetic variability and environmental stability of wheat will help food producers to grow low allergen food that could be used as a safe and healthy alternative to complete wheat avoidance. We have developed the first complete representation of the proteins related to the different forms of immune response in humans, which has helped us to accurately determine the genetic variability of these proteins and their environmental vulnerability.” Along with mapping the location of these proteins on the wheat genome, the research team investigated how the environment affected the expression of proteins in developing grain and the resulting effect on human health. “Seed grain protein content strongly depends on the environmental conditions during growing and so it is extremely important for the development of low allergen wheat products.” The researchers identified that certain growing conditions had a strong effect on the amount of proteins triggering food allergies in wheat. “Climate change and the increase in global temperatures accompanied by more frequent spikes of extreme temperatures can stress crops in a range of ways, and we found this temperature stress changed the expression of the immunoreactive proteins. When the growing season had a cool finish we found an increase in proteins related to baker’s asthma and food allergies. On the other hand, high temperature stress at the flowering stage of the growing season increased the expression of major proteins associated with coeliac disease and WDEIA. These results will help food producers to identify grains with reduced allergen and antigen content.” The study is published in Science Advances.

Light at the end of the nano tunnel for imaging

Researchers from the University of Technology Sydney working with light and nanoparticles say they have found the sweet spot for super resolution imaging, demonstrating that safer and cheaper super resolution technology is a real possibility. Using a new nanomaterial, upconversion nanoparticles (UCNPs), to probe thick tissue, the researchers said that they have overcome two long-standing challenges to using photonics in super resolution imaging: using low laser power to break through the optical diffraction limit, and developing an efficient way to carry light beyond the first layers of human tissue to a depth that will allow single molecules or nanomedicines to be observed in 3D culture. “Light scatters, the deeper you penetrate tissue with light the more it is absorbed and the more it scatters, impairing the resolution,” said the authors. “We demonstrated that there is an optical narrow window in the near infrared wavelength range, a sweet spot if you like, that allows light to penetrate deeper into tissue, beyond 50 nanometers which, up until now, has been considered the limit of optical detection,” he says. Having overcome this first challenge, the team then used the unique emission wavelengths of a special type of UCNP (upconversion super dots) in the near infrared range to act as a probe. “Having broken through the 50 nm limit we demonstrated the technology at a liver, brain or kidney tissue depth of 100 microns [100 000 nm], where you could still see a single molecule, which means there is the potential to detect a single disease biomarker. This is a very powerful tool for nanomedicine.” The research is published in Nature Communications.

What’s new online and open access at the MJA

20 August Research: Dr Google in the ED: searching for online health information by adult emergency department patients
Cocco et al; doi: 10.5694/mja17.00889
The doctor–patient relationship can benefit from discussing health-related internet searches by adult patients … OPEN ACCESS permanently

20 August Podcast: Professor Peter Munk, Professor of Radiology, Orthopaedics and Palliative Care at the University of British Columbia, and Editor-in-Chief of the Canadian Association of Radiologists Journal, talking about predatory journals … OPEN ACCESS permanently

20 August Podcast: Dr Simone Visser, respiratory physician at Royal Prince Alfred Hospital, and Clinical Associate Professor Lucy Morgan, senior respiratory physician at Concord Repatriation General Hospital, talking about bronchiectasis … OPEN ACCESS permanently

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