Research news in brief

Lab-on-a-chip blood test good news for pregnant women

Researchers from the University of South Australia (UniSA) have isolated fetal cells from maternal blood using a tiny device etched with millions of microchannels, a microfluidic chip, allowing for improved genetic testing using tiny volumes of fluid. A wide range of fetal genetic abnormalities could soon be detected in early pregnancy thanks to the lab-on-a-chip (LOC), non-invasive technology. LOC technology integrates laboratory functions on a small device ranging from a few millimetres to a few square centimetres in size. The special design of the chip allows large volumes of blood to be screened, paving the way for an efficient, cheap and quick method of separating fetal cells from maternal blood cells. Currently, prenatal diagnostic tests involve an amniocentesis procedure or taking a sample of cells from the placenta (chorionic villus sampling), both of which carry a risk of inducing miscarriage. The UniSA researchers, working in collaboration with the University of Technology Sydney and specialists from the Women’s and Children’s Hospital, SA Pathology and Repromed, adapted the device from one initially developed to isolate tumour cells from the blood of patients with cancer. News of the breakthrough was published in Advanced Materials Technologies.

Foods combining fats and carbohydrates more rewarding for our brains

German researchers have shown that the reward centre of the brain values foods high in both fat and carbohydrates – that is, many processed foods – more than foods containing one or the other, according to a study published in Cell Metabolism. The study of 206 adults supports the idea that these kinds of foods hijack our body’s inborn signals governing food consumption. In work that could help explain brain–body mechanisms underlying the genetic predisposition for obesity, eating in the absence of hunger, and difficulty losing or keeping off excess weight, the researchers looked at the neural response to food cues. Test subjects underwent brain scans while being shown photographs of familiar snacks containing mostly fat, mostly sugar, and a combination of fat and carbohydrates. Allocated a limited amount of money to bid on their first-choice foods, subjects were willing to pay more for foods that combined fat and carbohydrates. The fat–carbohydrate combination lit up neural circuits in the reward centre of the brain more than a favourite food, a potentially sweeter or more energy-dense food, or a larger portion size. After the domestication of plants and animals and the development of grain and dairy production around 12 000 years ago, opportunities to consume fat and carbohydrates together increased, but processed foods such as doughnuts, which could contain 11 g of fat and 17 g of carbohydrate, have only been around for 150 years, not long enough for us to evolve a new brain response to them. Scientists believe our past experience with the nutritive properties of carbohydrates releases dopamine in the brain through an as-yet-unknown metabolic signal. These kinds of signals seem to help regulate what and how much we eat. The researchers theorised that the simultaneous activation of fat and carbohydrate signaling pathways launches an effect that human physiology has not evolved to handle. Consistent with this suggestion, rodents given access to fat alone or carbohydrate alone regulate their total daily caloric intake and body weight. But given unrestricted access to fat and carbohydrates, they quickly gain weight.

Hepatitis C-infected lungs may be safe as donor organs

Donor lungs from individuals infected with hepatitis C have been successfully transplanted into 10 patients at Toronto General Hospital (TGH) in Canada, according to experts presenting at the Global Hepatitis Summit on 14–17 June 2018. All patients have recovered from their transplant surgery. Eight of them have already tested negative for the virus after successfully completing a short course of the new directly acting antiviral (DAA) drugs, which cure hepatitis C. The last two patients have recently started taking the drug regimen. The transplants are part of a clinical trial that is the first to assess the safety of transplanting hepatitis-positive organs to non-infected patients using ex vivo technology. Developed at TGH in 2008, the Toronto Ex Vivo Lung Perfusion System (EVLP) perfuses organs outside of the body, allowing doctors to assess the organ and predict how well it will do before transplantation. In recent years, the latest drug regimen of sofosbuvir–velpatasvir for a 12-week period has been used to cure patients with hepatitis C around the world. However, there were still concerns around how this could affect transplants. The questions researchers want to answer are: can hepatitis C-negative patients be safely transplanted with infected donor organs, and can they clear the virus after their surgery. For this study, lungs were placed in the EVLP circuit in a sterile dome for 6 hours. The surgical team was able to evaluate the lung function and be certain that the organs were suitable for transplant, despite being infected with hepatitis C. After 6 hours, EVLP reduced the hepatitis C virus count to very low levels. As expected, patients still contracted the disease. However, they tested negative for hepatitis C within only 3 weeks of treatment with DAAs, on average.

What’s new online at the MJA

18 June Position statement summary: Australian standards of care and treatment guidelines for transgender and gender diverse children and adolescents
Telfer et al; doi: 10.5694/mja17.01044
These are the first guidelines to be developed for TGD children and adolescents in Australia … FREE ACCESS for one week.

18 June Podcast with Associate Professor Michelle Telfer, director of the Royal Children’s Hospital (Melbourne) Gender Service … OPEN ACCESS permanently.

18 June Podcast with Professor Michael Baigent, psychiatrist, and Dr Ruth Baigent, GP … OPEN ACCESS permanently.

18 June Podcast with Professor Saxby Pridmore, psychiatrist at University of Tasmania and St Helen’s Hospital, Hobart … OPEN ACCESS permanently.

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