Medicine (St Vincent's) - Research Publications

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    Sugar-sweetened beverage (SSB) consumption, correlates and interventions among Australian Aboriginal and Torres Strait Islander communities: a scoping review
    Wright, KM ; Dono, J ; Brownbill, AL ; Pearson (nee Gibson), O ; Bowden, J ; Wycherley, TP ; Keech, W ; O'Dea, K ; Roder, D ; Avery, JC ; Miller, CL (BMJ PUBLISHING GROUP, 2019-06)
    OBJECTIVES: Sugar-sweetened beverage (SSB) consumption in Australian Aboriginal and Torres Strait Islander people is reported to be disproportionally high compared with the general Australian population. This review aimed to scope the literature documenting SSB consumption and interventions to reduce SSB consumption among Australian Aboriginal and Torres Strait Islander people. Findings will inform strategies to address SSB consumption in Aboriginal and Torres Strait Islander communities. METHODS: PubMed, SCOPUS, CINAHL, Informit, Joanna Briggs Institute EBP, Mura databases and grey literature were searched for articles published between January 1980 and June 2018. Studies were included if providing data specific to an Australian Aboriginal and/or Torres Strait Islander population's SSB consumption or an intervention that focused on reducing SSB consumption in this population. DESIGN: Systematic scoping review. RESULTS: 59 articles were included (1846 screened). While reported SSB consumption was high, there were age-related and community-related differences observed in some studies. Most studies were conducted in remote or rural settings. Implementation of nutrition interventions that included an SSB component has built progressively in remote communities since the 1980s with a growing focus on community-driven, culturally sensitive approaches. More recent studies have focused exclusively on SSB consumption. Key SSB-related intervention elements included incentivising healthier options; reducing availability of less-healthy options; nutrition education; multifaceted or policy implementation (store nutrition or government policy). CONCLUSIONS: There was a relatively large number of studies reporting data on SSB consumption and/or sales, predominantly from remote and rural settings. During analysis it was subjectively clear that the more impactful studies were those which were community driven or involved extensive community consultation and collaboration. Extracting additional SSB-specific consumption data from an existing nationally representative survey of Aboriginal and Torres Strait Islander people could provide detailed information for demographic subgroups and benchmarks for future interventions. It is recommended that a consistent, culturally appropriate, set of consumption measures be developed.
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    IL-23 costimulates antigen-specific MAIT cell activation and enables vaccination against bacterial infection
    Wang, H ; Kjer-Nielsen, L ; Shi, M ; D'Souza, C ; Pediongco, TJ ; Cao, H ; Kostenko, L ; Lim, XY ; Eckle, SBG ; Meehan, BS ; Zhu, T ; Wang, B ; Zhao, Z ; Mak, JYW ; Fairlie, DP ; Teng, MWL ; Rossjohn, J ; Yu, D ; de St Groth, BF ; Lovrecz, G ; Lu, L ; McCluskey, J ; Strugnell, RA ; Corbett, AJ ; Chen, Z (AMER ASSOC ADVANCEMENT SCIENCE, 2019-11-01)
    Mucosal-associated invariant T (MAIT) cells are activated in a TCR-dependent manner by antigens derived from the riboflavin synthesis pathway, including 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU), bound to MHC-related protein-1 (MR1). However, MAIT cell activation in vivo has not been studied in detail. Here, we have found and characterized additional molecular signals required for optimal activation and expansion of MAIT cells after pulmonary Legionella or Salmonella infection in mice. We show that either bone marrow–derived APCs or non–bone marrow–derived cells can activate MAIT cells in vivo, depending on the pathogen. Optimal MAIT cell activation in vivo requires signaling through the inducible T cell costimulator (ICOS), which is highly expressed on MAIT cells. Subsequent expansion and maintenance of MAIT-17/1-type responses are dependent on IL-23. Vaccination with IL-23 plus 5-OP-RU augments MAIT cell–mediated control of pulmonary Legionella infection. These findings reveal cellular and molecular targets for manipulating MAIT cell function under physiological conditions.
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    Evidence-Practice Gaps in Postdischarge Initiation With Oral Anticoagulants in Patients With Atrial Fibrillation.
    Schaffer, AL ; Falster, MO ; Brieger, D ; Jorm, LR ; Wilson, A ; Hay, M ; Leeb, K ; Pearson, S ; Nasis, A (Ovid Technologies (Wolters Kluwer Health), 2019-12-17)
    Background Oral anticoagulant (OAC) therapy reduces the risk of stroke in people with atrial fibrillation (AF), and is considered best practice; however, there is little Australian evidence around the uptake of OACs in this population. Methods and Results We used linked hospital admissions, pharmaceutical dispensing claims, medical services, and mortality data for people in Australia's 2 most populous states (July 2010 to June 2015). Among OAC-naïve people hospitalized with AF, we estimated initiation of OAC therapy within 30 days of discharge, and persistence with therapy in the first year. We analyzed both outcomes using multivariable Cox regression. In 71 184 people with AF (median age 78 years, 49% female), 22.7% initiated OAC therapy. Initiation was lowest in July to December 2011 (17.0%) and highest in July to December 2014 (30.1%) after subsidy of the direct OACs. In adjusted analyses, initiation was most likely in people with a CHA2DS2-VA score ≥7 (versus 0) (hazard ratio=6.25, 95% CI 5.08-7.69), and a history of venous thromboembolism (hazard ratio=2.65, 95% CI 2.49-2.83). Of the people who initiated OAC therapy, 39.9% discontinued within 1 year; a lower risk of discontinuation was associated with a CHA2DS2-VA score ≥7 (versus 0) (hazard ratio=0.22, 95% CI 0.14-0.35), or initiation on a direct OAC (versus warfarin) (hazard ratio=0.55, 95% CI 0.50-0.60). Conclusions We found that OAC therapy was severely underutilized in people hospitalized with AF, even among high-risk individuals. Reasons for this underuse, whether patient, prescriber, or hospital related, should be identified and addressed to reduce stroke-related morbidity and mortality in people with AF.
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    Purulent pneumococcal pericarditis, a vaccine-preventable illness.
    Rees, MJ ; Wilson, A (Oxford University Press (OUP), 2019-08)
    A 74-year-old gentleman presented to hospital with a 1-day history of acute onset pleuritic chest pain and fever. He was found to have widespread ST segment elevation on electrocardiogram, and blood cultures taken were positive for Streptococcus pneumoniae. Two days following admission the patient developed dyspnea, and a large pericardial effusion and right middle lobe consolidation were demonstrated on a computed tomography scan of the chest. A transthoracic echocardiogram confirmed the presence of a large circumferential pericardial effusion with multiple prominent adhesions and marked heterogenous thickening of the pericardium, without evidence of tamponade. Pericardiocentesis drained a purulent exudate positive for pneumococcal antigen. The occurrence of purulent pericarditis secondary to pneumococcal community-acquired pneumonia is rare in the modern antibiotic era and represents an often-lethal manifestation of invasive pneumococcal disease (IPD). IPD is a vaccine-preventable illness for which adult vaccination rates are low despite high morbidity. Healthcare professionals need to vaccinate older patients opportunistically.
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    Efficacy of Endoscopic Dilation of Gastroduodenal Crohn's Disease Strictures: A Systematic Review and Meta-Analysis of Individual Patient Data
    Bettenworth, D ; Muecke, MM ; Lopez, R ; Singh, A ; Zhu, W ; Guo, F ; Matsui, T ; James, TW ; Herfarth, H ; Goetz, M ; Mao, R ; Kurada, S ; Hampe, J ; Matthes, K ; Karstensen, JG ; Valli, PV ; Duijvestein, M ; D'Haens, G ; Jairath, V ; Qiu, TB ; Ding, NS ; Rogler, G ; Rieder, F (ELSEVIER SCIENCE INC, 2019-11)
    BACKGROUND & AIMS: Little is known about the effects of endoscopic balloon dilation (EBD) for strictures of the upper gastrointestinal (UGI) tract in patients with Crohn's disease (CD). We performed a pooled analysis of the efficacy and safety of EBD for UGI CD-associated strictures. METHODS: We searched Embase, Medline, and the Cochrane library, as well as bibliographies of relevant articles, for cohort studies of adults with CD and strictures of the stomach or duodenum (up to the ligament of Treitz) who underwent EBD through December 2016. We obtained data from 7 international referral centers on 94 patients who underwent 141 EBDs. We performed a patient-level meta-analysis of data from published and unpublished cohort studies to determine mechanical and clinical success. We performed a time-to-event analysis to assess symptom recurrence and need for redilation or surgery. The patients analyzed had strictures of the duodenum (n = 107), stomach (n = 30), or spanning both (n = 4). RESULTS: The rate of technical success for EBD was 100%, with 87% short-term clinical efficacy; major complications arose from 2.9% of all procedures. During a median follow-up period of 23.1 months, 70.5% of patients had a recurrence of symptoms, 59.6% required redilation, and 30.8% required surgical intervention. Patients whose disease was located in the small bowel had a higher risk for symptom recurrence (hazard ratio [HR], 2.1; P = .003). Asian race (HR, 2.8; P < .001) and location of disease in the small bowel (HR, 1.9; P = .004) increased the need for redilation. Prestenotic dilation was a risk factor for needing surgery earlier (HR, 1.9; P = .001). CONCLUSIONS: In a meta-analysis, we found EBD for CD-associated strictures of the UGI to be an effective alternative to surgery, with a high rate of short-term technical and clinical success, moderate long-term efficacy, and an acceptable rate of complications.
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    The Fanconi Anemia Pathway and Fertility
    Tsui, V ; Crismani, W (ELSEVIER SCIENCE LONDON, 2019-03)
    Fanconi anemia (FA) is a life-threatening syndrome characterized by bone marrow failure and cancer predispositions. The past two decades have seen an explosion of data in the FA field, both in humans and other organisms, following the cloning of 22 FA genes. A common but notably understudied clinical feature of the disease is the reduced fertility of individuals with FA. This review focuses on the known causes of reduced fertility in FA, and integrates them with the emerging role of the FA pathway in double-strand break (DSB) repair at meiosis in a variety of organisms, as well as providing future directions for research and diagnostics.
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    Identification of a Neural Mass Model of Burst Suppression
    Jafarian, A ; Freestone, DR ; Nesic, D ; Grayden, D (IEEE, 2019)
    Burst suppression includes alternating patterns of silent and fast spike activities in neuronal activities observable in micro to macro scale recordings. Biological models of burst suppression are given as dynamical systems with slow and fast states. The aim of this paper is to give a method to identify parameters of a mesoscopic model of burst suppression that can provide insights into study underlying generators of intracranial electroencephalogram (iEEG) data. An optimisation technique based upon a genetic algorithm (GA) is employed to find feasible model parameters to replicate burst patterns in the iEEG data with paroxysmal transitions. Then, a continuous discrete unscented Kalman filter (CD-UKF) is used to infer hidden states of the model and to enhance the identification results from the GA. The results show promise in finding the model parameters of a partially observed mesoscopic model of burst suppression.
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    Slow-Fast Duffing Neural Mass Model
    Jafarian, A ; Freestone, DR ; Nesic, D ; Grayden, D (IEEE, 2019)
    Epileptic seizures may be initiated by random neuronal fluctuations and/or by pathological slow regulatory dynamics of ion currents. This paper presents extensions to the Jansen and Rit neural mass model (JRNMM) to replicate paroxysmal transitions in intracranial electroencephalogram (iEEG) recordings. First, the Duffing NMM (DNMM) is introduced to emulate stochastic generators of seizures. The DNMM is constructed by applying perturbations to linear models of synaptic transmission in each neural population of the JRNMM. Then, the slow-fast DNMM is introduced by considering slow dynamics (relative to membrane potential and firing rate) of some internal parameters of the DNMM to replicate pathological evolution of ion currents. Through simulation, it is illustrated that the slow-fast DNMM exhibits transitions to and from seizures with etiologies that are linked either to random input fluctuations or pathological evolution of slow states. Estimation and optimization of a log likelihood function (LLF) using a continuous-discrete unscented Kalman filter (CD-UKF) and a genetic algorithm (GA) are performed to capture dynamics of iEEG data with paroxysmal transitions.
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    Endoscopic features of buried Barrett's mucosa: visible to the trained eye?
    Yang, L ; Holt, B ; Williams, R ; Tsoi, E ; Cameron, G ; Desmond, P ; Taylor, A (Wiley, 2019-12-01)
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    Perceptions of Doppler ultrasound for rheumatoid arthritis disease activity assessment and education
    Joshua, F ; Bailey, C ; Marabani, M ; Romas, E ; White, R ; Wong, P (WILEY, 2019-01)
    AIM: The aim of this qualitative study was to report the findings of the Defining rheumatoid arthritis progression using Doppler Ultrasound in Clinical practice (DEDUCE) Medical Practice Activity, which was developed to facilitate the utilization of Doppler ultrasound (DUS) by Australian rheumatologists in the treatment of patients with rheumatoid arthritis (RA). METHOD: Twenty-one rheumatologists recruited a total of 80 patients with RA in Disease Activity Score of 28 joints (DAS28) remission for DUS assessment and completed a pre- and post-activity questionnaire assessing their experience with DUS, as well as a 6-month follow-up questionnaire. Rheumatologists discussed DUS results with patients using visual aids. Patients completed a pre- and post-DUS assessment questionnaire. Data were summarized using descriptive statistics. RESULTS: Following completion of the activity, 95% of rheumatologists (20/21) believed DUS was a useful assessment tool for patients with RA. The majority found the DUS results useful and more than half thought the DUS assessment fit well into their consultation. A majority of rheumatologists indicated they would use DUS imaging in patients with low disease activity and remission, and for disease activity assessment to inform in therapeutic decision-making. All patients who responded found the visual aids useful and most felt that discussing DUS results improved understanding of their disease and would help with medication adherence. CONCLUSION: Incorporation of DUS imaging into routine clinical practice is feasible, encourages rheumatologists to utilize and expand their clinical application of DUS imaging in patients with RA, and may improve patient understanding of their disease and adherence to medication.