Teleost and elasmobranch eye lenses as a target for life-history stable isotope analyses

Incrementally grown, metabolically inert tissues such as fish otoliths provide biochemical records that can used to infer behavior and physiology throughout the lifetime of the individual. Organic tissues are particularly useful as the stable isotope composition of the organic component can provide information about diet, trophic level and location. Unfortunately, inert, incrementally grown organic tissues are relatively uncommon. The vertebrate eye lens, however, is formed via sequential deposition of protein-filled fiber cells, which are subsequently metabolically inert. Lenses therefore have the potential to serve as biochemical data recorders capturing life-long variations in dietary and spatial ecology. Here we review the state of knowledge regarding the structure and formation of fish eye lenses in the context of using lens tissue for retrospective isotopic analysis. We discuss the relationship between eye lens diameter and body size, describe the successful recovery of expected isotopic gradients throughout ontogeny and between species, and quantify the isotopic offset between lens protein and white muscle tissue. We show that fish eye lens protein is an attractive host for recovery of stable isotope life histories, particularly for juvenile life stages, and especially in elasmobranchs lacking otoliths, but interpretation of lens-based records is complicated by species-specific uncertainties associated with lens growth rates

Paracrine signalling events in embryonic stem cell renewal mediated by affinity targeted nanoparticles

AbstractStem cell growth and differentiation is controlled by intrinsic and extrinsic factors. The latter includes growth factors, which are conventionally supplied in vitro in media exchanged daily. Here, we illustrate the use of affinity targeted biodegradable nanoparticles to mediate paracrine stimulation as an alternative approach to sustain the growth and pluripotency of mouse embryonic stem cells. Leukaemia Inhibitory Factor (LIF) was encapsulated in biodegradable nanoparticles and targeted to the cell surface using an antibody to the oligosaccharide antigen SSEA-1. Sustained release of LIF from nanoparticles composed of a solid Poly(lactide-co-glycolic acid) polyester or a hydrogel-based liposomal system, we term Nanolipogel, replenished once after each cell passage, proved as effective as daily replenishment with soluble LIF for maintenance of pluripotency after 5 passages using 104-fold less LIF. Our study constitutes an alternative paradigm for stem cell culture, providing dynamic microenvironmental control of extrinsic bioactive factors benefiting stem cell manufacturing

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research

Out-of-hospital administration of corticosteroids to patients with acute asthma: A case study and literature review

Introduction Asthma is an important health problem in Australia with more than 2.2. million Australians currently diagnosed with Asthma. Asthma is associated with significant mortality and frequent use of emergency medical services. The objectives of this paper were to: a) present a case study of a near-fatal episode of severe acute asthma in which the patient was administered corticosteroids by an Ambulance Service of New South Wales Extended Care Paramedic; b) review the epidemiology and pathophysiology of acute asthma as well as current pharmacotherapy in asthma management; and c) conduct a literature search and critical appraisal of existing evidence supporting the out-of-hospital administration of corticosteroids for acute asthma by paramedics. Methods The purpose of the literature search was to identify comparative studies of adult patients with “acute” asthma treated by paramedics with corticosteroids prior to arrival at the emergency department (ED) to evaluate whether this intervention is associated with improved outcomes. A literature search of databases included the Cochrane Database of Systematic Reviews (Cochrane Reviews Issue 4 2008), Cochrane Central Register of Controlled Trials (Clinical Trials), Medline (1950- November 2008), EMBASE and CINAHL. A pre-hospital filter was applied to increase the sensitivity of the searches as appropriate. MeSH headings included exp/asthma, exp/hydrocortisone, exp/prednisone, exp/prednisolone and exp/glucocorticoids. Searched text words included asthma, hydrocortisone, prednisone and prednisolone. Titles and abstracts of interest were inspected to identify relevant articles with the full text of selected articles retrieved. Identified papers were independently appraised by two reviewers. Results Only two original studies were identified. The first was a retrospective comparative study of adult patients with moderate to severe asthma who received 125 mg methylprednisolone prior to transport to hospital or after arrival in the ED. The second study was a retrospective chart review to determine whether the out-of-hospital administration of systemic steroids to asthmatic patients had any effect on hospital admission rates. Conclusion Corticosteroids have been widely used in the hospital setting for many years in the treatment of acute asthma and there is good evidence to support their early administration in an ED setting. Out-of-hospital studies provide only weak evidence of benefit. There is insufficient evidence of adequate quality to determine if corticosteroids should be routinely used by paramedics. A prospective randomised controlled trial is needed to determine the true value of early corticosteroid administration in the ambulance setting

Rurality as a factor in ambulance use in health emergencies

Introduction Ambulance use in rural and remote parts of Australia has been reported anecdotally to be lower than urban areas. Experiences of paramedics in rural locations gave rise to questions of whether this phenomenon was occurring and to what degree. Methods Data from emergency department (ED) records was obtained from the Hunter New England Area Health Service from 1 July 2008 to 30 June 2009. In total, 354,909 records were obtained. These records were de-identified and analysed to determine the method of arrival to ED, specifically in high acuity patients. Results People from inner regional areas are 41.5% less likely overall and 27.7% less likely in serious health emergencies to attend EDs by ambulance compared to people in major cities. People from outer regional and remote areas are 55.1% less likely overall and 27.9% less likely in serious health emergencies to attend EDs by ambulance compared to people living in major cities. Logistic regression modelling indicated rurality was a significant factor in ambulance use in adults in areas outside major cities and in children in inner regional areas. Age was a significant predictor of ambulance demand with older people using ambulances more. Discussion This study indicates disparity between rates of ambulance use in urban and non-urban areas. The concept of unmet need should be considered as a more complex phenomenon than simply a utilisation gap and exploration of unmet need is warranted. Conclusion A clearer understanding of how rurality affects ambulance use has a number of implications for ambulance services

Prehospital non-invasive ventilation for acute cardiogenic pulmonary oedema : an evidence-based review

Background: Non-invasive ventilation (NIV) is increasingly being implemented by many ambulance jurisdictions as a standard of care in the out-of-hospital management of acute cardiogenic pulmonary oedema (ACPO). This implementation appears to be based on the body of evidence from the emergency department (ED) setting, with the assumption that earlier administration by paramedics would give benefits with regard to inhospital mortality and the rate of endotracheal intubation beyond those seen when initiated in the ED. This paper sought to identify and review the current level of evidence supporting NIV in the prehospital setting. Methods: Electronic searches of Medline, EMBASE, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Database of Controlled Trials were conducted and reference lists of relevant articles were hand searched. Results: The search identified 12 primary studies documenting the use of NIV, either continuous positive airway pressure or bi-level non-invasive ventilation, for ACPO in the out-of-hospital setting. Only three studies were randomised controlled trials, with none addressing inhospital mortality as a primary outcome measure. The majority of articles were non-comparative descriptive studies. Conclusion: Early prehospital NIV appears to be a safe and feasible therapy that results in faster improvement in physiological status and may decrease the need for intubation when compared with delayed administration in the ED. There is weak evidence that is may decrease mortality. The cost versus benefit equation of system-wide prehospital implementation of NIV is unclear and, based on the current evidence, should be considered with caution

The Sonographic OODA Loop : Proposing a beginner’s model for learning point of care ultrasound

Unlike practitioners of diagnostic sonography, point of care ultrasound users must often acquire basic ultrasound skills in far shorter time frames, with less time dedicated to obtaining mastery, and therefore often rely on conceptual models to achieve this. There is currently no introductory model which point of care ultrasound users might adopt to describe the cognitive processes involved in acquiring a basic ultrasound image, and in learning point of care ultrasonography. We propose the ‘Sonographic OODA Loop’ in reference to Boyd’s Observe -Orient –Decide-Act (OODA) decision loop, as a model which can be used initially by ultrasound-naive clinicians to understand the cognitive and motor processes that occur when they acquire ultrasound images, and hopefully achieve greater insight into their early practice

Delayed versus immediate defibrillation for out-of-hospital cardiac arrest due to ventricular fibrillation : a systematic review and meta-analysis of randomised controlled trials

Background: Humanstudies over the last decade have indicated that delaying initial defibrillation to allow a short period of cardiopulmonary resuscitation (CPR) may promote a more responsive myocardial state that is more likely to respond to defibrillation and result in increased rates of restoration of spontaneous circulation (ROSC) and/or survival. Out-of-hospital studies have produced conflicting results regarding the benefits of CPR prior to defibrillation in relation to survival to hospital discharge. The aim of this study was to conduct a systematic review and meta-analysis of randomised controlled trials comparing the effect of delayed defibrillation preceded by CPR with immediate defibrillation on survival to hospital discharge. Methods: A systematic literature search of key electronic databases including Medline, EMBASE, and the Cochrane Library was conducted independently by two reviewers. Randomised controlled trials meeting the eligibility criteria were critically appraised according to the Cochrane Group recommended methodology. Meta-analyses were conducted for the outcomes of survival to hospital discharge overall and according to response time of emergency medical services. Results: Three randomised controlled trials were identified which addressed the question of interest. All included studies were methodologically appropriate to include in a meta-analysis. Pooled results from the three studies demonstrated no benefit from providing CPR prior to defibrillation compared to immediate defibrillation for survival to hospital discharge (OR 0.94 95% CI 0.46–1.94). Meta-analysis of results according to ambulance response time (≤5 min or >5 min) also showed no difference in survival rates. Conclusion: Delaying initial defibrillation to allow a short period of CPR in out-of-hospital cardiac arrest due to VF demonstrated no benefit over immediate defibrillation for survival to hospital discharge irrespective of response time. There is no evidence that CPR before defibrillation is harmful. Based on the existing evidence, EMS jurisdictions are justified continuing with current practice using either defibrillation strategy