Publications by authors named "Brian Chambers"

We tested if the personality of captive-raised western ringtail possums (Pseudocheirus occidentalis), and the impact of other variables would influence their survival after release using radiotelemetry. We hypothesised a greater survival for individuals: (i) bold; (ii) habituated in advance to food collected from the release area; (iii) juveniles instead of adults, because more easily tolerated by wild individuals, and (iv) released in new dreys (nests) as they would not have the strong odour of old dreys and would be less attractive to foxes. After 3 months of radio tracking, out of 143 possums released, 79 died: 51 (64.

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Background: Significant recent efforts have facilitated increased access to clinical genetics assessment and genomic sequencing for children with rare diseases in many centres, but there remains a service gap for adults. The Austin Health Adult Undiagnosed Disease Program (AHA-UDP) was designed to complement existing UDP programs that focus on paediatric rare diseases and address an area of unmet diagnostic need for adults with undiagnosed rare conditions in Victoria, Australia. It was conducted at a large Victorian hospital to demonstrate the benefits of bringing genomic techniques currently used predominantly in a research setting into hospital clinical practice, and identify the benefits of enrolling adults with undiagnosed rare diseases into a UDP program.

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Article Synopsis
  • The study investigates how sitting and standing positions affect cerebral blood flow (MCAv) in stroke patients within the first 48 hours and also 3-7 days post-stroke.
  • Using transcranial Doppler, researchers measured MCAv changes across different positions and compared results between stroke patients with and without occlusive disease, as well as healthy controls.
  • Findings revealed that affected hemisphere MCAv significantly decreased when patients with occlusive disease adjusted from a lying to an upright position, indicating potential harm and highlighting the need for careful monitoring of upright activity post-stroke.
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The impact of out-of-bed upright activity on outcomes in ischemic stroke patients with severe extra- and intracranial stenosis or occlusion is unknown. Using ultrasound findings from a cohort recruited to A Very Early Rehabilitation Trial (AVERT) which compared higher dose very early mobilisation (VEM) to usual care (UC), we aimed to explore the association between occlusive disease and 3-month outcomes and occlusive disease-by-mobilisation treatment interactions. Participants with ischemic stroke, with carotid and transcranial Doppler ultrasounds performed ≤1 week after admission, were included in this single centre substudy in Melbourne, Australia.

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Article Synopsis
  • The study investigates how different head positions after an ischaemic stroke affect cerebral blood flow (CBF), using various imaging methods across 21 studies involving 529 patients.
  • Most studies suggest that lying flat increases CBF in the affected hemisphere, while more upright positions generally decrease it, although results varied widely and some studies had high bias risk.
  • Data indicate a significant increase in CBF velocity when changing head position from 30° to 0°, highlighting the need for more research on the effects of sitting or standing shortly after a stroke, as this is common in clinical practice.
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Variability in transcranial Doppler (TCD) detection of embolic signals (ES) is important for risk stratification. We tested the effect of time of day on ES associated with 60-99% asymptomatic carotid stenosis. Subjects were from the Asymptomatic Carotid Stenosis Embolus Detection (ASED) Study such that half were previously ES-positive and half ES-negative with 6-monthly 60-min TCD monitoring.

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A circular economy relies on demonstrating the quality and environmental safety of wastes that are recovered and reused as products. Policy-level risk assessments, using generalised exposure scenarios, and informed by stakeholder communities have been used to appraise the acceptability of necessary changes to legislation, allowing wastes to be valued, reused and marketed. Through an extensive risk assessment exercise, summarised in this paper, we explore the burden of proof required to offer safety assurance to consumer and brand-sensitive food sectors in light of attempts to declassify, as wastes, quality-assured, source-segregated compost and anaerobic digestate products in the United Kingdom.

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Background and Purpose- Impaired microvascular reperfusion despite complete recanalization (no-reflow) represents a potential therapeutic target to improve outcomes after recanalization therapies. Although well documented in animal models, this phenomenon has not been demonstrated clinically. We investigated whether transcranial Doppler can detect acute microvascular changes postrecanalization as a biomarker of the no-reflow phenomenon in stroke patients.

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The rapid and large-scale urbanization of peri-urban areas poses major and complex challenges for wildlife conservation. We used population viability analysis (PVA) to evaluate the influence of urban encroachment, fire, and fauna crossing structures, with and without accounting for inbreeding effects, on the metapopulation viability of a medium-sized ground-dwelling mammal, the southern brown bandicoot (Isoodon obesulus), in the rapidly expanding city of Perth, Australia. We surveyed two metapopulations over one and a half years, and parameterized the PVA models using largely field-collected data.

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Background: Cognitive impairment is common in type 2 diabetes mellitus, and there is a strong association between type 2 diabetes and Alzheimer's disease. However, we do not know which type 2 diabetes patients will dement or which biomarkers predict cognitive decline. Left ventricular hypertrophy (LVH) is potentially such a marker.

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Offshore oil production facilities are frequently victims of internal piping corrosion, potentially leading to human and environmental risks and significant economic losses. Microbially influenced corrosion (MIC) is believed to be an important factor in this major problem for the petroleum industry. However, knowledge of the microbial communities and metabolic processes leading to corrosion is still limited.

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Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.

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Objectives & Methods: We evaluated internal jugular vein and vertebral vein volume flow using ultrasound, in patients with clinically isolated syndrome or mild multiple sclerosis and controls, to determine whether volume flow was different between the two groups.

Results: In patients and controls, internal jugular vein volume flow increased from superior to inferior segments, consistent with recruitment from collateral veins. Internal jugular vein and vertebral vein volume flow were greater on the right in supine and sitting positions.

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Objectives: We designed a prospective case-control study of patients with clinically isolated syndrome (CIS) and Relapsing-Remitting Multiple Sclerosis (RRMS) with an Expanded Disability Status Score (EDSS) of ≤2, compared with age-and-sex-matched healthy controls, to test the hypothesis that chronic cerebrospinal venous insufficiency (CCSVI) is more prevalent in patients with CIS or mild MS.

Methods: All subjects were examined using a Siemens Antares duplex ultrasound machine. The internal jugular, vertebral and intracranial veins were studied in subjects in both supine and sitting postures.

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Objective: This study investigated the sensitivity and specificity of the national mortality codes in identifying cardiovascular disease (CVD) deaths and documents methods of verification.

Methods: A 12-year retrospective case ascertainment of all ICD-coded CVD deaths was performed for deaths between 1990 and 2002 in the Melbourne Collaborative Cohort Study, comprising 41,528 subjects. Categories of non-CVD codes were also examined.

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Background: The endovascular treatment of carotid atherosclerosis with carotid artery stenting (CAS) remains controversial. Carotid endarterectomy remains the benchmark in terms of procedural mortality and morbidity. At present, there are no consensus Australasian guidelines for the safe performance of CAS.

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Introduction: Central nervous system (CNS) involvement is a common and less understood aspect of systemic lupus erythematosus (SLE). Microembolic signals (MES) have been reported in SLE. We conducted a prospective study to evaluate the frequency of MES among patients with CNS involvement and those without.

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Background And Purpose: End point adjudication committees (EPAC) are widely used in large-scale clinical trials to ensure the robustness of diagnosis for end points.

Methods: The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) was a double-blind randomized trial of blood pressure lowering in 6105 participants with pre-existing cerebrovascular disease. Separate estimates of the effects of randomized treatment were determined using Cox regression models that were based on the unadjudicated events initially reported by the investigator and on the final events assigned by the EPAC.

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Background And Purpose: We have noted the presence of small strip-like infarcts involving the cortex within the interdivisional territory of the middle cerebral artery (MCA) and sometimes extending to the periventricular region. The incidence in a stroke unit population, mechanisms, clinical expression and prognosis of patients with these cortical infarcts are unknown. To clarify these issues we retrospectively and prospectively identified these patients in our own stroke unit population.

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Microembolic signals (MES) detected by transcranial Doppler (TCD) have been reported in subarachnoid hemorrhage (SAH), although their origin and contribution to brain ischemia remain uncertain. We conducted a prospective study to evaluate the frequency of MES among patients with SAH and to determine their origin. Twenty-seven patients with SAH, comprising 15 aneurysmal and 12 non-aneurysmal patients, participated in the study.

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Background And Purpose: Small-vessel knock is a recently reported Doppler ultrasound finding that has been identified in patients with cerebral ischemia. It has been hypothesized that knock-type signals are linked to the presence of either small-vessel occlusion or wall motion. The aim of this study was to investigate the origins of "knock-type" signals by reproducing occlusion of a peripheral artery model in vitro.

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The benefit of prophylactic carotid endarterectomy (CEA) for patients with asymptomatic severe carotid stenosis in the major randomised surgical studies was small, expensive and may now be absorbed by improvements in best practice medical intervention. Strategies to identify patients with high stroke risk are needed. If surgical intervention is to be considered the complication rates of individual surgeons should be available.

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Asymptomatic carotid artery stenosis.

Curr Treat Options Cardiovasc Med

April 2007

Severe asymptomatic carotid stenosis is associated with a stroke risk of approximately 2% per annum. Aggressive management of risk factors is recommended, including cessation of smoking, and treatment of hypertension, diabetes, and hypercholesterolemia. Patients should be treated with antiplatelet agents.

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Grain Cd concentrations were determined in wheat (Triticum aestivum L.) grown in 1999, 2001 and 2003, at six sludge cake field experiments. Three of these sites also had comparisons with Cd availability from metal amended liquid sludge and metal salts.

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Background And Purpose: We tested the hypothesis that transcranial Doppler embolic signal (ES) detection identifies an increased risk of ipsilateral carotid stroke or transient ischemic attack (TIA) in subjects with asymptomatic severe carotid stenosis.

Methods: Subjects with duplex-determined 60% to 99% carotid stenosis, without other apparent cerebroembolic sources, underwent 6-monthly neurological assessment and 60-minute ES monitoring. ES positivity was defined as > or =1 ES detected in > or =1 study, ES negativity as no ES in any study, and consistent ES negativity as no ES in any study where > or =6 studies were performed.

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