Validation of a clinical decision rule: chest X-ray in patients with chest pain and possible acute coronary syndrome

Current literature suggests that a large proportion of chest X-rays (CXRs) performed in emergency department (ED) patients with chest pain and suspected acute coronary syndrome (ACS) are unnecessary. The Canadian ACS Guidelines aim to guide clinicians in the appropriate use of CXR within this patient population. This study determined the prevalence of clinically significant CXR abnormalities and assessed the utility of the guidelines in a population of ED patients with chest pain and suspected ACS. Included in the study were participants over the age of 18 who presented to an Australian metropolitan ED, over a 1-year period, with a primary complaint of chest pain and who had a CXR and troponin level ordered in the ED (N?=?760). We retrospectively compared their radiographic findings with their recommendations for CXR according to the ACS Guidelines. We found that 12 % of the participants had a clinically significant chest X-ray. The guidelines had a sensitivity of 80 % (95 % CI 0.70–0.87) and specificity of 50 % (95 % CI 0.47–0.54). The positive predictive value was 18 % (95 % CI 0.15–0.22) with a 95 % negative predictive value (95 % CI 0.92–0.97). Had the ACS guidelines been applied to our patient population, the number of CXR performed would have been reduced by 47 %. This study suggests that the ACS Guidelines has the potential to reduce the numbers of unnecessary CXR performed in ED patients. However, this would come at the expense of missing a minority of significant CXR abnormalities.     

Effects of voluntary wheel running on mitochondrial content and dynamics in rat skeletal muscle

Journal of Muscle Research and Cell Motility - This study reports that in rat skeletal muscle the proteins specifically responsible for mitochondrial dynamics, mitofusin-2 (MFN2) and mitochondrial...     

Mouse Lung Structure and Function after Long-Term Exposure to an Atmospheric Carbon Dioxide Level Predicted by Climate Change Modeling

Background: Climate change models predict that atmospheric carbon dioxide [CO2] levels will be between 700 and 900 ppm within the next 80 y. Despite this, the direct physiological effects of exposure to slightly elevated atmospheric CO2 (as compared with ∼410 ppm experienced today), especially when exposures extend from preconception to adulthood, have not been thoroughly studied.Objectives: In this study we aimed to assess the respiratory structure and function effects of long-term exposure to 890 ppm CO2 from preconception to adulthood using a mouse model.Methods: We exposed mice to CO2 (∼890 ppm) from prepregnancy, through the in utero and early life periods, until 3 months of age, at which point we assessed respiratory function using the forced oscillation technique, and lung structure.Results: CO2 exposure resulted in a range of respiratory impairments, particularly in female mice, including higher tissue elastance, longer chord length, and lower lung compliance. Importantly, we also assessed the lung function of the dams that gave birth to our experimental subjects. Even though these mice had been exposed to the same level of increased CO2 for a similar amount of time (∼8wk), we measured no impairments in lung function. This suggests that the early life period, when lungs are undergoing rapid growth and development, is particularly sensitive to CO2.Discussion: To the best of our knowledge, this study, for the first time, shows that long-term exposure to environmentally relevant levels of CO2 can impact respiratory function in the mouse. https://doi.org/10.1289/EHP7305