A practical method to simulate realistic reduced-exposure CT images by the addition of computationally generated noise.

Computed tomography (CT) scanning protocols should be optimized to minimize the radiation dose necessary for imaging. The addition of computationally generated noise to the CT images facilitates dose reduction. The objective of this study was to develop a noise addition method that reproduces the complexity of the noise texture present in clinical images with directionality that varies over images according to the underlying anatomy, requiring only Digital Imaging and Communications in Medicine (DICOM) images as input data and commonly available phantoms for calibration.

A Method of Correcting for the Effect of Temperature on Low-Contrast Penetration Measurement in Urethane Phantoms.

Urethane-based test objects are routinely used for ultrasound quality assurance because of their durability and robustness. The acoustic properties of these phantoms including speed of sound and attenuation, however, have a strong dependence on temperature. Reliable measurement of low-contrast penetration, which is widely used for ultrasound system quality assurance testing, with these phantoms is therefore problematic.

Can a renal nurse assess fluid status using ultrasound on the inferior vena cava? A cross-sectional interrater study.

Introduction: Ultrasound of the inferior vena cava (IVC-US) has been used to estimate intravascular volume status and fluid removal during a hemodialysis session. Usually, renal nurses rely on other, imprecise methods to determine ultrafiltration. To date, no study has examined whether renal nurses can reliably perform ultrasound for volume assessment and for potential prevention of intradialytic hypotension.

Is Grey Level a Suitable Alternative to Low-Contrast Penetration as a Serial Measure of Sensitivity in Computerised Ultrasound Quality Assurance?

The aim of this study was to test the hypothesis that grey levels are a suitable alternative measure of sensitivity in ultrasound imaging quality assurance, as there are several caveats in the use of penetration depth. In a primary cohort of nine probes, where measurements had been made for 6 to 34 mo, both penetration depth and mean grey level fell below tolerance for six probes; both penetration depth and mean grey level remained within tolerance for three probes. In a secondary cohort where a measurement programme had been in place for a shorter period, grey level and/or penetration depth fell below tolerance in 15 of 66 probes; the sensitivity and specificity of at least 10% loss of grey level in predicting >5% loss in penetration depth were 91% and 93%, respectively.

Use of ultrasound by registered nurses-a systematic literature review.

Background: In Western Australia (WA), most stable patients undergoing haemodialysis receive treatment in a satellite setting where no doctors are on-site during treatment hours, so nurses must make critical decisions about fluid removal. Some patients regularly experience adverse events during dialysis (intradialytic), often due to excessive ultrafiltration goals, with intradialytic hypotension being particularly challenging. Ultrasound of the inferior vena cava has been previously demonstrated being a rapid and non-invasive method for volume assessment on haemodialysis patients, thus could hold valuable information for the treating nurse.

Effects of emergency department Care Coordination Team referrals in older people presenting with a fall.

Objectives: The study aims to describe the characteristics of patients presenting to an ED with a fall and evaluate multidisciplinary Care Coordination Team (CCT) referrals on patient outcomes.

Methods: A single-centred retrospective analysis of electronic data at an adult tertiary hospital was performed using data from 2004 to 2009 of presentations for patients aged 65 years or over with a fall. The primary outcome measure was representation to hospital within 30 days, comparing patients referred to CCT and those not referred.

Direct and glia-mediated effects of GABA on development of central olfactory neurons.

Previously studied for its role in processing olfactory information in the antennal lobe, GABA also may shape development of the olfactory pathway, acting either through or on glial cells. Early in development, the dendrites of GABAergic neurons extend to the glial border that surrounds the nascent olfactory lobe neuropil. These neuropil glia express both GABAA and GABAB receptors, about half of the glia in acute cultures responded to GABA with small outward currents, and about a third responded with small transient increases in intracellular calcium.

Activation of glial FGFRs is essential in glial migration, proliferation, and survival and in glia-neuron signaling during olfactory system development.

Development of the adult olfactory system of the moth Manduca sexta depends on reciprocal interactions between olfactory receptor neuron (ORN) axons growing in from the periphery and centrally-derived glial cells. Early-arriving ORN axons induce a subset of glial cells to proliferate and migrate to form an axon-sorting zone, in which later-arriving ORN axons will change their axonal neighbors and change their direction of outgrowth in order to travel with like axons to their target areas in the olfactory (antennal) lobe. These newly fasciculated axon bundles will terminate in protoglomeruli, the formation of which induces other glial cells to migrate to surround them.

Analysis of 22,655 presentations with back pain to Perth emergency departments over five years.

Background: Back pain is a significant cause of disability in the community, but the impact on Emergency Departments (EDs) has not been formally studied. Patients with back pain often require significant time and resources in the ED.

Aims: To examine the characteristics of patients presenting with back pain to the ED, including final diagnosis, demographics of those attending and temporal distribution of presentations.

Cardiovascular mortality in men with erectile dysfunction: increased risk but not inevitable.

Introduction: It is unclear whether men with erectile dysfunction (ED) ultimately die of cardiovascular (CV) causes.

Aim: This study examined the causes of death in men with ED and their risk of CV death.

Methods: Based on statutory death registrations and hospital morbidity data, the risk of CV death in men with ED in a linked-data study was assessed against the CV mortality risk in a reference male population.

Cell adhesion molecules in context: CAM function depends on the neighborhood.

Cell adhesion molecules (CAMs) are now known to mediate much more than adhesion between cells and between cells and the extracellular matrix. Work by many researchers has illuminated their roles in modulating activation of molecules such as receptor tyrosine kinases, with subsequent effects on cell survival, migration, and process extension. CAMs also are known to serve as substrates for proteases which can create diffusible fragments capable of signaling independently from the CAM.

Paediatric frequent attenders at emergency departments: a linked-data population study.

Aim: To characterise the phenomena of paediatric frequent attenders (FAs) to emergency departments (EDs) in Perth.

Methods: A linked data population study of all children (<15 years) attending Perth hospital EDs between 1 July 2000 and 31 December 2006. FAs attending five or more times annually were assessed for demographic characteristics, mode of arrival, urgency, clinical conditions and disposition by frequency of attendance.

Localization of a GABA transporter to glial cells in the developing and adult olfactory pathway of the moth Manduca sexta.

Glial cells have several critical roles in the developing and adult olfactory (antennal) lobe of the moth Manduca sexta. Early in development, glial cells occupy discrete regions of the developing olfactory pathway and processes of gamma-aminobutyric acid (GABA)ergic neurons extend into some of these regions. Because GABA is known to have developmental effects in a variety of systems, we explored the possibility that the glial cells express a GABA transporter that could regulate GABA levels to which olfactory neurons and glial cells are exposed.

Short-term risk of adverse outcome is significantly higher in patients returning an abnormal troponin result when tested in the emergency department.

Objective: Describe short-term mortality and hospitalization outcomes in patients undergoing troponin testing in Western Australia tertiary public hospital ED.

Methods: Retrospective cohort study of adults presenting to urban tertiary ED between July 2000 and December 2004, and undergoing troponin inhibitory or tropomyosin binding testing. Patient data relating to ED attendance, troponins, hospitalization and death were linked using probabilistic data linkage.

Erectile dysfunction as a predictor for subsequent atherosclerotic cardiovascular events: findings from a linked-data study.

Introduction: In spite of the mounting interest in the nexus between erectile dysfunction (ED) and cardiovascular (CV) diseases, there is little published information on the role of ED as a predictor for subsequent CV events.

Aim: This study aimed to investigate the role of ED as a predictor for atherosclerotic CV events subsequent to the manifestation of ED. Method.

Roles of specific membrane lipid domains in EGF receptor activation and cell adhesion molecule stabilization in a developing olfactory system.

Background: Reciprocal interactions between glial cells and olfactory receptor neurons (ORNs) cause ORN axons entering the brain to sort, to fasciculate into bundles destined for specific glomeruli, and to form stable protoglomeruli in the developing olfactory system of an experimentally advantageous animal species, the moth Manduca sexta. Epidermal growth factor receptors (EGFRs) and the cell adhesion molecules (IgCAMs) neuroglian and fasciclin II are known to be important players in these processes.

Methodology/principal Findings: We report in situ and cell-culture studies that suggest a role for glycosphingolipid-rich membrane subdomains in neuron-glia interactions.

Emergency Department diagnosis of pulmonary embolism is associated with significantly reduced mortality: a linked data population study.

Objectives: We characterized patients admitted via ED with a principal hospital discharge diagnosis of pulmonary embolism (PE) and compared mortality of those diagnosed in the ED with those diagnosed after admission.

Methods: Patients with a hospital discharge diagnosis ICD 10 I26 presenting to the ED in Perth, Western Australia between 1 July 2000 and 30 December 2006 had records from the Emergency Department Information System linked to the Western Australian Hospital Morbidity Data System and the death registry.

Results: Of 2250 patients (mean age 60.

Use of emergency departments by older people from residential care: a population based study.

Objective: to investigate the differences between emergency department (ED) presentations of older people who do and do not live in residential care facilities (RCFs).

Design: a population-based retrospective cohort study. ED records linked to ambulance and hospital morbidity records.

Frequent attenders at emergency departments: a linked-data population study of adult patients.

Objectives: To examine the characteristics of adult patient attendances to emergency departments (EDs) in Perth hospitals by patients' frequency of attendance.

Design, Setting And Participants: A linked-data population study of adults (aged > or = 15 years) attending all nine Perth hospital EDs between 1 July 2000 and 31 December 2006.

Main Outcome Measures: Proportion of frequent attenders (FAs; those attending five or more times annually); and demographic characteristics, mode of arrival at the ED, disposition (admission, transfer, discharge or death), urgency and clinical conditions by frequency of attendance.

Activation of epidermal growth factor receptor mediates receptor axon sorting and extension in the developing olfactory system of the moth Manduca sexta.

During development of the adult olfactory system of the moth Manduca sexta, olfactory receptor neurons extend axons from the olfactory epithelium in the antenna into the brain. As they arrive at the brain, interactions with centrally derived glial cells cause axons to sort and fasciculate with other axons destined to innervate the same glomeruli. Here we report studies indicating that activation of the epidermal growth factor receptor (EGFR) is involved in axon ingrowth and targeting.

Glycosylation patterns are sexually dimorphic throughout development of the olfactory system in Manduca sexta.

In the moth Manduca sexta, development of the adult olfactory system depends on complex interactions between olfactory receptor neurons in the antenna, antennal-lobe neurons in the brain, and several classes of glial cells. As one approach to characterizing molecules that may play roles in these interactions, we used lectins to screen antennae and antennal lobes at different stages of adult development. We find that each of the major neural cell types has a distinct pattern of labeling by lectins.

Bidirectional influences between neurons and glial cells in the developing olfactory system.

Olfactory systems serve as excellent model systems for the study of numerous widespread aspects of neural development and also for the elucidation of features peculiar to the formation of neural circuits specialized to process odor inputs. Accumulated research reveals a fine balance between developmental autonomy of olfactory structures and intercellular interactions essential for their normal development. Recent findings have uncovered evidence for more autonomy than previously realized, but simultaneously have begun to reveal the complex cellular and molecular underpinnings of key interactions among neurons and glial cells at several important steps in olfactory development.

Presence of unsaturated sphingomyelins and changes in their composition during the life cycle of the moth Manduca sexta.

NMR and electrospray ionization tandem mass spectrometry were used to show for the first time the presence of sphingomyelins in extracts of the tobacco hornworm Manduca sexta (Lepidoptera). The sphingosine in the ceramide was identified as tetradecasphing-4-enine, and the fatty acids were C18:0, C20:0, C22:0, and C24:0 (compound 1). Heterogeneity in the ceramide was observed in sphingomyelins from M.

Objective measurements of image quality.

Tissue harmonic imaging (THI) and compound imaging have been reported clinically to improve contrast resolution, tissue differentiation and overall image quality. However, there have been limited studies to date to quantify objectively the improvements in image quality achieved with these new imaging techniques. The aim of this study was to quantify differences in image quality that exist between conventional B-mode imaging, harmonic imaging, compound imaging and harmonic compound imaging.

The effect of speed of sound in ultrasound test objects on lateral resolution.

Urethane test objects are available that are more durable than traditional gel-based objects. Their ultrasound (US) propagation speed differs from scanner calibration velocity. This is clearly a disadvantage in checking caliper accuracy, but its effect on other measurements such as resolution is not well known.