Characterisation of a microelectrochemical biosensor for real-time detection of brain extracellular d-serine.

A modified development protocol and concomitant characterisation of a first generation biosensor for the detection of brain extracellular d-serine is reported. Functional parameters important for neurochemical monitoring, including sensor sensitivity, O interference, selectivity, shelf-life and biocompatibility were examined. Construction and development involved the enzyme d-amino acid oxidase (DAAO), utilising a dip-coating immobilisation method employing a new extended drying approach.

A physiatrist's role in managing unique challenges in pregnancy and delivery in a patient with incomplete lumbar SCI: a case report.

Introduction: Women of childbearing age make up around 5-10% of individuals with spinal cord injury (SCI) and may face unique medical and functional complications during pregnancy, including prolonged hospitalization and increased risk of early rehospitalization due to falls.

Case Presentation: Here, we discuss a case of a young ambulatory woman with a lumbar motor incomplete spinal cord injury who underwent successful delivery via cesarean section and the role of the physiatrist in the management of the patient's antepartum, intrapartum, and postpartum complications. The patient faced significant antepartum challenges secondary to her neurogenic bladder and pelvic floor weakness, resulting in increased use of her manual wheelchair.

The Impacts of Burn Severity and Frequency on Erosion in Western Arnhem Land, Australia.

Wildfires are pivotal to the functioning of many ecosystems globally, including the magnitude of surface erosion rates. This study aims to investigate the relationships between surface erosion rates and wildfire intensity in the tropical north savanna of Australia. The occurrence of fires in western Arnhem Land, Northern Territory, Australia was determined with remotely sensed digital datasets as well as analogue erosion measurement methods.

Hyperthermia elevates brain temperature and improves behavioural signs in animal models of autism spectrum disorder.

Background: Autism spectrum disorders (ASD) are predominantly neurodevelopmental and largely genetically determined. However, there are human data supporting the idea that fever can improve symptoms in some individuals, but those data are limited and there are almost no data to support this from animal models. We aimed to test the hypothesis that elevated body temperature would improve function in two animal models of ASD.

Design optimisation and characterisation of an amperometric glutamate oxidase-based composite biosensor for neurotransmitter l-glutamic acid.

A polymer/enzyme composite biosensor for monitoring neurochemical glutamate was performance optimised in vitro for sensitivity, selectivity and stability. This first generation Pt/glutamate oxidase-based sensor displayed appropriate sensitivity (90.4 ± 2.

Quantifying spatial non-stationarity in the relationship between landscape structure and the provision of ecosystem services: An example in the New Zealand hill country.

Knowing how landscape structure affects the provision of ecosystem services (ES) is an important first step toward better landscape planning. Because landscape structure is often heterogenous across space, modelling the relationship between landscape structure and the provision of ES must account for spatial non-stationarity. This paper examines the relationship between landscape structure and the provision of ES using a hill country and steep-land case farm in New Zealand.

A first nation-wide assessment of soil-transmitted helminthiasis in Fijian primary schools, and factors associated with the infection, using a lymphatic filariasis transmission assessment survey as surveillance platform.

Background: Soil-transmitted helminthiasis (STH) is endemic in Fiji but its prevalence is not known and likely to have changed after a decade of mass drug administration (MDA) for lymphatic filariasis (LF). By linking with LF transmission assessment surveys (LF-TAS), we undertook the first nation-wide assessment of STH in Fijian primary schools, as well as an analysis of factors associated with STH infections.

Methodology/principal Findings: A cross-sectional assessment for STH was conducted in all four Divisions of Fiji from 2014 to 2015.

Development and validation of a real-time microelectrochemical sensor for clinical monitoring of tissue oxygenation/perfusion.

Oxygen is of critical importance to tissue viability and there is increasing demand for its reliable real-time clinical monitoring in order to prevent, diagnose, and treat several pathological disorders, including hypoxia, stroke and reperfusion injury. Herein we report the development and characterisation of a prototype clinical O2 sensor, and its validation in vivo, including proof-of-concept monitoring in patients undergoing surgery for carpal tunnel release. An integrated platinum-based microelectrochemical device was custom designed and controlled using a miniaturised telemetry-operated single channel clinical potentiostat.

Acute Inflammation Alters Brain Energy Metabolism in Mice and Humans: Role in Suppressed Spontaneous Activity, Impaired Cognition, and Delirium.

Systemic infection triggers a spectrum of metabolic and behavioral changes, collectively termed sickness behavior, which while adaptive, can affect mood and cognition. In vulnerable individuals, acute illness can also produce profound, maladaptive, cognitive dysfunction including delirium, but our understanding of delirium pathophysiology remains limited. Here, we used bacterial lipopolysaccharide (LPS) in female C57BL/6J mice and acute hip fracture in humans to address whether disrupted energy metabolism contributes to inflammation-induced behavioral and cognitive changes.

Environmental factors associated with diarrhoea prevalence among under-five children in the Mataniko settlements in Honiara, Solomon Islands.

Introduction: Children aged less than 5 years are often at high risk of diarrhoeal infection. In the Solomon Islands, diarrhoea is the second leading cause of under-five mortality with about one in every 10 children dying from it before reaching 5 years. This study aims to assess environmental factors that are associated with under-five diarrhoea prevalence in the Mataniko informal settlements, in Honiara, Solomon Islands.

The Use of the Abdominal Aortic and Junctional Tourniquet Versus Combat Gauze in a Porcine Hemicorporectomy Model.

Background: Junctional hemorrhage is a potentially preventable cause of death. The Abdominal Aortic and Junctional Tourniquet (AAJT) compresses major vascular structures and arrests blood flow in exsanguinating hemorrhage. In a human model, the AAJT was effective in stopping blood flow in the femoral arteries via compression of the distal aorta.

Cardiovascular Disease Risk Factors and Physical Fitness in Volunteer Firefighters.

Forty-seven percent of volunteer firefighter line of duty deaths are caused by cardiovascular events. Aggressive cardiovascular disease (CVD) risk factor reduction and improved physical fitness could reduce CVD mortality within this population. We assessed CVD risk factors and physical fitness in a large cohort of volunteer firefighters to help establish a health and fitness profile of this population, which may serve as evidence for the need to initiate programs aimed at reducing morbidity and mortality caused by CVD in the volunteer fire service.

Predictive risk mapping of an environmentally-driven infectious disease using spatial Bayesian networks: A case study of leptospirosis in Fiji.

Introduction: Leptospirosis is a zoonotic disease responsible for over 1 million severe cases and 60,000 deaths annually. The wide range of animal hosts and complex environmental drivers of transmission make targeted interventions challenging, particularly when restricted to regression-based analyses which have limited ability to deal with complexity. In Fiji, important environmental and socio-demographic factors include living in rural areas, poverty, and livestock exposure.

Multicomponent analysis using a confocal Raman microscope.

Measuring the concentration of multiple chemical components in a low-volume aqueous mixture by Raman spectroscopy has received significant interest in the literature. All of the contributions to date focus on the design of optical systems that facilitate the recording of spectra with high signal-to-noise ratio by collecting as many Raman scattered photons as possible. In this study, the confocal Raman microscope setup is investigated for multicomponent analysis.

Use of geographically weighted logistic regression to quantify spatial variation in the environmental and sociodemographic drivers of leptospirosis in Fiji: a modelling study.

Background: Leptospirosis is a globally important zoonotic disease, with complex exposure pathways that depend on interactions between human beings, animals, and the environment. Major drivers of outbreaks include flooding, urbanisation, poverty, and agricultural intensification. The intensity of these drivers and their relative importance vary between geographical areas; however, non-spatial regression methods are incapable of capturing the spatial variations.

Island-Wide Surveillance of Gastrointestinal Protozoan Infection on Fiji by Expanding Lymphatic Filariasis Transmission Assessment Surveys as an Access Platform.

As part of lymphatic filariasis (LF) transmission assessment surveys (TAS) on Fiji, an island-wide assessment of gastrointestinal protozoan infection was performed by inspection of a concomitant stool sample collection to investigate the distribution of parasitic protozoa. All grade 1 and 2 students of 69 schools on the two main islands were targeted in two phases (one in the Western Division and the other in the Central and Northern Divisions, except Taveuni sub-Division of Northern), where fecal samples of 1,800 students were available for coproscopy using formalin-ether-acetate concentration. The overall prevalence of infection was 1.

Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji.

Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen-specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji.

A cross-sectional seroepidemiological survey of typhoid fever in Fiji.

Fiji, an upper-middle income state in the Pacific Ocean, has experienced an increase in confirmed case notifications of enteric fever caused by Salmonella enterica serovar Typhi (S. Typhi). To characterize the epidemiology of typhoid exposure, we conducted a cross-sectional sero-epidemiological survey measuring IgG against the Vi antigen of S.

Real-time changes in hippocampal energy demands during a spatial working memory task.

Activity-dependent changes in hippocampal energy consumption have largely been determined using microdialysis. However, real-time recordings of brain energy consumption can be more accurately achieved using amperometric sensors, allowing for sensitive real-time monitoring of concentration changes. Here, we test the theory that systemic pre-treatment with glucose in rats prevents activity-dependent decreases in hippocampal glucose levels and thus enhances their performance in a spontaneous alternation task.

Coordinated Acetylcholine Release in Prefrontal Cortex and Hippocampus Is Associated with Arousal and Reward on Distinct Timescales.

Cholinergic neurotransmission throughout the neocortex and hippocampus regulates arousal, learning, and attention. However, owing to the poorly characterized timing and location of acetylcholine release, its detailed behavioral functions remain unclear. Using electrochemical biosensors chronically implanted in mice, we made continuous measurements of the spatiotemporal dynamics of acetylcholine release across multiple behavioral states.

The effect of NMDA-R antagonism on simultaneously acquired local field potentials and tissue oxygen levels in the brains of freely-moving rats.

Non-competitive NMDA receptor antagonists are known to induce psychosis-like symptoms in rodents. Administration of such compounds cause behavioural effects such as memory impairment and hyperlocomotion. Additionally, drugs such as phencyclidine (PCP), ketamine and MK-801 all cause distinctive increases in striatal local field potential (LFP) in the high frequency oscillation (HFO) band in the power spectrum (140-180 Hz).

Perioperative hepatocyte growth factor (HGF) infusions improve hepatic regeneration following portal branch ligation (PBL) in rodents.

Background: As hepatic surgery has become safer and more commonly performed, the extent of hepatic resections has increased. When there is not enough expected hepatic reserve to facilitate primary resection of hepatic tumors, a clinical adjunct to facilitating primary resection is portal vein embolization (PVE). PVE allows the hepatic remnant to increase to an appropriate size prior to resection via hepatocyte regeneration; however, PVE is not always successful in facilitating adequate regeneration.

Human Leptospirosis Infection in Fiji: An Eco-epidemiological Approach to Identifying Risk Factors and Environmental Drivers for Transmission.

Leptospirosis is an important zoonotic disease in the Pacific Islands. In Fiji, two successive cyclones and severe flooding in 2012 resulted in outbreaks with 576 reported cases and 7% case-fatality. We conducted a cross-sectional seroprevalence study and used an eco-epidemiological approach to characterize risk factors and drivers for human leptospirosis infection in Fiji, and aimed to provide an evidence base for improving the effectiveness of public health mitigation and intervention strategies.

Increased brain nitric oxide levels following ethanol administration.

Nitric oxide is a ubiquitous messenger molecule, which at elevated concentrations has been implicated in the pathogenesis of several neurological disorders. Its role in oxidative stress, attributed in particular to the formation of peroxynitrite, proceeds through its high affinity for the superoxide radical. Alcoholism has recently been associated with the induction of oxidative stress, which is generally defined as a shift in equilibrium between pro-oxidant and anti-oxidant species in the direction of the former.

A microelectrochemical biosensor for real-time in vivo monitoring of brain extracellular choline.

A first generation Pt-based polymer enzyme composite biosensor developed for real-time neurochemical monitoring was characterised in vivo for sensitive and selective detection of choline. Confirmation that the sensor responds to changes in extracellular choline was achieved using local perfusion of choline which resulted in an increase in current, and the acetylcholinesterase inhibitor neostigmine which produced a decrease. Interference by electroactive species was tested using systemic administration of sodium ascorbate which produced a rapid increase in extracellular levels before gradually returning towards baseline over several hours.