6,360 research outputs found
Support for mentors - An exploration of the issues
© 2016 MA Healthcare Ltd. Nursing and midwifery mentors are fundamental to the process of ensuring future practitioners are adequately prepared and supported during the practice element of their degrees. However, there is evidence to suggest that the infrastructure and support for the mentoring role is not always adequate. This article provides a review of some of the issues including the emotional labour associated with supporting pre-registration students, difficulties in accessing protected learning time for mentoring, and lack of supportive networks for mentors to develop within the role. The authors make recommendations on what is required to ensure that the mentor role is better acknowledged, supported and resourced
Using opioids in general practice for chronic non-cancer pain: An overview of current evidence
© 2016 AMPCo Pty Ltd. Produced with Elsevier B.V. All rights reserved. • Chronic non-cancer pain (lasting more than 3months) is highly prevalent in Australia (17% of males and 20%of females) and its optimal management is crucial to the health and wellbeing of the community. For 5% of the population, such pain interferesmarkedly with daily function. Part of the treatment for acute non-cancer pain for many people will include opioid analgesics at least for days to weeks. However, as pain becomes chronic, evidence to support ongoing prescription of opioids is lacking. There is increasing pressure to ensure that prescribing opioid analgesics is minimised to reduce not only the risk of dependence and illicit diversion but also the potential harms associated with tolerance, side effects and complications. • Frameworks for considering opioid prescribing include assessing suitability of the patient for opioids; initiating a trial of therapy; and monitoring long term use. There is limited evidence of the long term efficacy of opioids for chronic non-cancer pain, and documented clinical consequences beyond addiction include acceleration of loss of bone mineral density, hypogonadism and an association with increased risk of acute myocardial infarction. • Careful clinical selection of patients can help optimise the evidence-based use of opioids for chronic non-cancer pain: ► only treat pain that has been as well defined as possible when non-opioid therapies have not been effective; ► consider referral to specialist services for assessment if doses are above 100mg oral morphine equivalent per 24 hours or the duration of therapy is longer than 4 weeks; ► limit prescribing to only one practitioner; ► seek an agreement with the patient for the initiation and potential withdrawal of opioids if the therapeutic trial is not effective
Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum
Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribution is a common choice for this purpose (particularly for the inferential approach) because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions
On the potential for mapping apparent neural soma density via a clinically viable diffusion MRI protocol
Diffusion MRI is a valuable tool for probing tissue microstructure in the brain noninvasively. Today, model-based techniques are widely available and used for white matter characterisation where their development is relatively mature. Conversely, tissue modelling in grey matter is more challenging, and no generally accepted models exist. With advances in measurement technology and modelling efforts, a clinically viable technique that reveals salient features of grey matter microstructure, such as the density of quasi-spherical cell bodies and quasi-cylindrical cell projections, is an exciting prospect. As a step towards capturing the microscopic architecture of grey matter in clinically feasible settings, this work uses a biophysical model that is designed to disentangle the diffusion signatures of spherical and cylindrical structures in the presence of orientation heterogeneity, and takes advantage of B-tensor encoding measurements, which provide additional sensitivity compared to standard single diffusion encoding sequences. For the fast and robust estimation of microstructural parameters, we leverage recent advances in machine learning and replace conventional fitting techniques with an artificial neural network that fits complex biophysical models within seconds. Our results demonstrate apparent markers of spherical and cylindrical geometries in healthy human subjects, and in particular an increased volume fraction of spherical compartments in grey matter compared to white matter. We evaluate the extent to which spherical and cylindrical geometries may be interpreted as correlates of neural soma and neural projections, respectively, and quantify parameter estimation errors in the presence of various departures from the modelling assumptions. While further work is necessary to translate the ideas presented in this work to the clinic, we suggest that biomarkers focussing on quasi-spherical cellular geometries may be valuable for the enhanced assessment of neurodevelopmental disorders and neurodegenerative diseases
Overlapping Patterns of Rapid Evolution in the Nucleic Acid Sensors cGAS and OAS1 Suggest a Common Mechanism of Pathogen Antagonism and Escape
A diverse subset of pattern recognition receptors (PRRs) detects pathogen-associated nucleic acids to initiate crucial innate immune responses in host organisms. Reflecting their importance for host defense, pathogens encode various countermeasures to evade or inhibit these immune effectors. PRRs directly engaged by pathogen inhibitors often evolve under recurrent bouts of positive selection that have been described as molecular ‘arms races.’ Cyclic GMP-AMP synthase (cGAS) was recently identified as a key PRR. Upon binding cytoplasmic double-stranded DNA (dsDNA) from various viruses, cGAS generates the small nucleotide secondary messenger cGAMP to signal activation of innate defenses. Here we report an evolutionary history of cGAS with recurrent positive selection in the primate lineage. Recent studies indicate a high degree of structural similarity between cGAS and 2’-5’-oligoadenylate synthase 1 (OAS1), a PRR that detects double-stranded RNA (dsRNA), despite low sequence identity between the respective genes. We present comprehensive comparative evolutionary analysis of cGAS and OAS1 primate sequences and observe positive selection at nucleic acid binding interfaces and distributed throughout both genes. Our data revealed homologous regions with strong signatures of positive selection, suggesting common mechanisms employed by unknown pathogen encoded inhibitors and similar modes of evasion from antagonism. Our analysis of cGAS diversification also identified alternately spliced forms missing multiple sites under positive selection. Further analysis of selection on the OAS family in primates, which comprises OAS1, OAS2, OAS3 and OASL, suggests a hypothesis where gene duplications and domain fusion events result in paralogs that provide another means of escaping pathogen inhibitors. Together our comparative evolutionary analysis of cGAS and OAS provides new insights into distinct mechanisms by which key molecular sentinels of the innate immune system have adapted to circumvent viral-encoded inhibitors
Identifying factors that predict worse constipation symptoms in palliative care patients: A secondary analysis
© Copyright 2017, Mary Ann Liebert, Inc. 2017. Objective: The aim of this work was to investigate whether variables identified as likely to impact the experience of constipation in other clinical settings similarly affected the experiences of constipated palliative care patients. Background: The majority of palliative care patients with cancer are likely to be bothered by constipation symptoms at some point in their disease trajectory. Despite this, it remains unclear as to which factors predict more severe problems. Methods: This study was conducted in a sample of 94 constipated palliative care patients who were asked to voluntarily complete a series of questions regarding their demographic and other characteristics, including whether they had chronic constipation symptoms, that is, constipation symptoms for 12 months. Other variables included age, body mass index, sex, performance status, and regular opioids and their doses. At the same time, they were asked to complete the Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires. Results: Descriptive statistics summarized baseline data. Unadjusted associations between the selected variables on PAC-SYM were examined by using bi-variate analyses. Significant variables identified on bi-variate analyses were included in a multivariate analysis. The final results identified that only the chronicity of constipation symptoms predicted more severe symptoms. This relationship persisted when this single variable was retained in the final model, illustrating that PAC-SYM scores are 0.41 higher in patients with chronic constipation compared with those without it (p = 0.02). In contrast, regular opioid use was not identified as a significant factor (p = 0.56). Discussion: This study suggests that the factor most likely to predict worse constipation symptoms was the duration that people had experienced problems. Further, those who perceived their constipation symptoms to be more severe had a poorer quality of life. More work is required to better define constipation risk factors and ways to best modify a patient's experiences
Prospectively Collected Characteristics of Adult Patients, Their Consultations and Outcomes as They Report Breathlessness When Presenting to General Practice in Australia
Introduction:Breathlessness is a subjective sensation, so understanding its impacts requires patients' reports, including prospective patient-defined breathlessness as a reason for presenting to general practitioners (GP).The aim of this study was to define the prevalence of breathlessness as a reason for GP consultations while defining the clinico-demographic factors of these patients and the characteristics and outcomes of those consultations.Methods:Using nine years of the Family Medicine Research Centre database of 100 consecutive encounters from 1,000 practices annually, the patient-defined reason for encounter 'breathlessness' was explored using prospectively collected data in people ≥18 years with clinical data coded using the International Classification for Primary Care V2. Dichotomous variables were analysed using chi square and 95% confidence intervals calculated using Kish's formula for a single stage clustered design.Results:Of all the 755,729 consultations collected over a nine year period from 1 April, 2000, 7255 included breathlessness as a reason for encounter (0.96%; 95% CI 0.93 to 0.99) most frequently attributed to chronic obstructive pulmonary disease. Only 48.3% of GPs saw someone reporting breathlessness. The proportion of consultations with breathlessness increased with age. Breathlessness trebled the likelihood that the consultation occurred in the community rather than the consulting room (p<0.0001) and increased 2.5 fold the likelihood of urgent referral to hospital (p<0.0001). Of those with breathlessness, 12% had undiagnosed breathlessness at the end of the consultation (873/7255) with higher likelihood of being younger females.Discussion:Breathlessness is a prevalent symptom in general practitioner. Such prevalence enables future research focused on understanding the temporal pattern of breathlessness and the longitudinal care offered to, and outcomes for these patients, including those who leave the consultation without a diagnosis. © 2013 Currow et al
Clinician-reported changes in octreotide prescribing for malignant bowel obstruction as a result of an adequately powered phase III study: A transnational, online survey
© The Author(s) 2018. Background: Translating research evidence into clinical practice often has a long lag time. Aim: To determine the impact of a phase III randomised controlled trial on palliative care clinicians’ self-reported practice change. Design: Online survey about use of octreotide in managing inoperable malignant bowel obstruction due to cancer or its treatments distributed in November 2016, 2 years after the first publication of the study in a peer-reviewed journal. Demographic, self-reported practice and the reasons underpinning this were collected. Responses were aggregated to ‘practice modified’ or ‘practice not modified’. A multinomial regression model explored predictors of practice change. Setting: Members of the Australian New Zealand Society of Palliative Medicine. Results: Response rate was 20.8% (106/509): 55.6% were aged >50 years, 56.5% were female and 77% had previously prescribed octreotide for this clinical indication. Out of 106 respondents, 52 (49.1%) indicated modified practice (60.9% of those who had previously prescribed octreotide in this setting). In those who reported practice change, most frequently octreotide was now used when other therapies failed; for not changing practice, ‘more confirmatory evidence was needed’ was most often cited. In the regression model, older age (clinician age = 50–59 years; relative risk = 0.147; 95% confidence interval = 0.024–0.918; p = 0.04) and having practices with lower proportions of people treated with octreotide (0%–20%; relative risk = 0.039; 95% confidence interval = 0.002–0.768; p = 0.033) predicted greater self-reported practice change. Conclusion: Clinician-reported change in practice in the survey is seen in the majority of respondents. This suggests that there is a cohort of ‘early adopters’ within palliative care practice as new evidence becomes available
A randomised, double blind, placebo-controlled trial of megestrol acetate or dexamethasone in treating symptomatic anorexia in people with advanced cancer
This multi-site, double blind, parallel arm, fixed dose, randomised placebo controlled phase III study compared megestrol acetate 480 mg/day with dexamethasone 4 mg/day for their net effects on appetite in people with cancer anorexia. Patients with advanced cancer and anorexia for ≥ 2 weeks with a score ≤ 4 (0-10 numeric rating scale (NRS) 0 = no appetite, 10 = best possible appetite) were recruited. Participants received megestrol 480 mg or dexamethasone 4 mg or placebo daily for up to 4 weeks. Primary outcomes were at day 7. Responders were defined as having a ≥ 25% improvement in NRS over baseline. There were 190 people randomised (megestrol acetate n = 61; dexamethasone n = 67, placebo n = 62). At week 1 (primary endpoint), 79·3% in the megestrol group, 65·5% in the dexamethasone group and 58·5% in the placebo group (p = 0.067) were responders. No differences in performance status or quality of life were reported. Treatment emergent adverse events were frequent (90·4% of participants), and included altered mood and insomnia. Hyperglycemia and deep vein thromboses were more frequent when on dexamethasone than the other two arms. There was no difference in groups between the three arms, with no benefit seen over placebo with anorexia improving in all arms.Trail registration: The trial was registered on 19/08/2008 with the Australian New Zealand Clinical Trials Registry (ACTRN12608000405314)
- …