Research news in brief

Improved dressings urgently needed for IV catheter failures

Griffith University researchers have compared three alternative dressings and securements to try to prevent peripheral intravenous catheter (PIVC) failure in adults, with results published in The Lancet. IVCs are the most common invasive medical devices used in hospitals. Around 2 billion devices are sold globally each year, and most patients who are admitted to hospital require intravenous therapy. PIVC failure is unacceptably common: up to 69% of devices require removal due to dislodgement, pain, occlusion, leakage or infection. The National Health and Medical Research Council funded the research, which took place in Brisbane at the Royal Brisbane and Women’s Hospital and the Princess Alexandra Hospital. The trial took 1807 eligible patients aged 18 years and over who required PIVC insertion for clinical treatment for longer than 24 hours, and randomly assigned them to receive tissue adhesive with polyurethane dressing, bordered polyurethane dressing, a securement device with polyurethane dressing, or polyurethane dressing (control group). Overall, 41% of patients had all-cause PIVC failure. None of the interventions significantly reduced PIVC failure. All products tested, including polyurethane, were associated with PIVC failure and often needed reinforcement. The researchers wrote that innovation to develop effective, durable products is urgently needed, and that the study indicates that substantial savings could be made for the Australian health system if clinicians use low cost polyurethane dressings for PIVCs, in the absence of a clinical rationale for use of a more expensive product.

Plant science discovery may unlock treatments for genetic diseases

Researchers from Monash University have discovered a new molecular mechanism of gene regulation, which could have major implications for the development of treatment strategies for Friedreich’s ataxia – the most commonly inherited genetic ataxia affecting young adults, for which there is currently no cure. The disease occurs due to a type of DNA mutation referred to as “triplet repeat expansion”. In individuals affected by Friedreich’s ataxia, the mutation is present in a region (known as intron) of the affected gene, which is removed during the production of mRNA. However, the presence of the expansion typically leads to reduction in the levels of mRNA, which in turn results in reduced protein, leading to disease. In the Monash study, published in Cell, the researchers made their discovery using the model plant Arabidopsis thaliana. “When we found the first and only triplet expansion-associated genetic defect outside humans, we asked the fundamental question ‘how do triplet expansions lead to reduced mRNA levels?’,” Associate Professor Sureshkumar Balasubramanian said. “We show … that triplet repeat expansions lead to accumulation of small RNAs, and these small RNAs target the gene harbouring the repeat expansion via epigenetic gene silencing. We have pointed at least 11 different genes in this process, and it is remarkable that if we perturb these genes, we can abolish the negative impacts of this mutation – at least in plants.”

Researchers identify 40 new genetic markers for glaucoma

A team from QIMR Berghofer Medical Research Institute have identified 40 new genetic markers that increase a person’s risk of developing glaucoma. The genome-wide study of more than 134 000 people found 101 genetic markers that influence the fluid pressure in a person’s eye, called intraocular pressure. High intraocular pressure is commonly associated with an increased risk of developing glaucoma. Associate Professor Stuart MacGregor said that the study, published in Nature Genetics, found that individuals with a large number of the genetic markers had an almost six-fold increased risk of developing glaucoma compared with someone who had fewer genetic variants. “Although a predictive test for glaucoma is not available yet, our discovery is very promising. If we can identify who is most at risk of developing glaucoma at the earliest opportunity, we can make sure those individuals receive the preventative treatment they need to stop them from going blind as they age. While the findings increased the number of known genetic markers underpinning intraocular pressure by more than 90, the most surprising finding was the sheer number of those variants that were associated with developing glaucoma. We were able to show 53 of the genetic markers do directly increase your risk of developing glaucoma and particularly increase the risk of developing advanced glaucoma, the type that tends to cause blindness.”

Safely opening and closing the blood‒brain barrier

A phase 1 clinical trial in five patients with Alzheimer’s disease has shown that the blood–brain barrier (BBB) can be non-invasively and reversibly opened, as reported in Nature Communications. The results show that the procedure is safe; however, conclusions cannot be drawn about the efficacy of focused ultrasound in treating the clinical symptoms of Alzheimer’s. The BBB represents an obstacle for the delivery of therapeutics to the brain. Focused ultrasound, in combination with injectable microbubbles, has been used to effectively open the BBB and to promote amyloid clearance in animal models of Alzheimer’s disease. It has also been delivered to patients with brain tumours using an implanted device. The researchers, from Sunnybrook Health Sciences Centre in Canada, used a non-invasive device to deliver focused ultrasound to amyloid-rich regions in the right frontal lobe of five patients (three men and two women) with mild to moderate Alzheimer’s disease. Results showed that the procedure rapidly and reversibly led to BBB opening in all five patients, with no significant adverse events. No clinically significant changes were detected in amyloid imaging markers, or in the cognitive function of the patients. These results show that this procedure is safe, but larger studies will be required to determine whether the procedure is effective in clearing amyloid and improving cognitive function.

What’s new online at the MJA

30 July Research: Implantable cardioverter–defibrillator therapy in Australia, 2002–2015
Blanch et al; doi: 10.5694/mja17.01183
ICD procedures are becoming more frequent in Australia, particularly in people aged 70 years or more … OPEN ACCESS permanently

30 July Research: Drought-related stress among farmers: findings from the Australian Rural Mental Health Study
Austin et al; doi: 10.5694/mja17.01200
Farmers who are younger, experience financial hardship, or are isolated are at particular risk of drought-related stress … OPEN ACCESS permanently

30 July Podcast with Ms Emma Austin from the Centre for Water, Climate and Land at the University of Newcastle, and Professor David Perkins, Director of UON’s Centre for Rural and Remote Mental Health … OPEN ACCESS permanently

30 July Perspective: Glycaemic control apps for diabetes: lifting the lid
Barmanray et al; doi: 10.5694/mja18.00066
We need to establish guidelines and a framework to ensure the development of effective, safe and relevant health apps, with appropriate regulatory oversight … FREE ACCESS for one week

30 July Podcast with Adjunct Professor Kylie Ward, CEO of the Australian College of Nursing … OPEN ACCESS permanently

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