Prolonged recovery of acute kidney injury following AngioJet rheolytic thrombectomy

AngioJet rheolytic thrombectomy, although a successful treatment modality for arterial thrombus removal and recanalization, has been shown to have increased rates of postoperative acute kidney injury (AKI) compared with other methods of treatment for acute limb ischemia. The postinterventional course of AKI can differ markedly from patient to patient, but typically resolves relatively quickly. Herein, we present a case of AKI secondary to AngioJet intervention that demonstrates an exceedingly prolonged but ultimately recoverable course with conservative management and without the need for renal replacement therapy

Management of complete iliofemoral artery avulsion with a hybrid technique

Transcatheter aortic valve replacement is a viable alternative for patients who are too high risk for traditional surgical aortic valve replacement, but it is not without risk of vascular complication. We report a case in which a hybrid stent and bypass graft technique was used to repair a complete iliofemoral artery avulsion after a transcatheter aortic valve replacement procedure. We believe that particular caution should be taken with patients with peripheral arterial disease in access vessels. Access vessel diameter must be considered in planning of procedures, and preprocedural preparation for potential major vascular complications is crucial for reducing morbidity and mortality

Long-term ozone exposure and mortality in a large prospective study

RATIONALE: Tropospheric ozone (O3) is potentially associated with cardiovascular disease risk and premature death. Results from long-term epidemiological studies on O3 are scarce and inconclusive. OBJECTIVES: In this study, we examined associations between chronic ambient O3 exposure and all-cause and cause-specific mortality in a large cohort of U.S. adults. METHODS: Cancer Prevention Study II participants were enrolled in 1982. A total of 669,046 participants were analyzed, among whom 237,201 deaths occurred through 2004. We obtained estimates of O3 concentrations at the participant's residence from a hierarchical Bayesian space-time model. Estimates of fine particulate matter (particulate matter with an aerodynamic diameter of up to 2.5 μm [PM2.5]) and NO2 concentrations were obtained from land use regression. Cox proportional hazards regression models were used to examine mortality associations adjusted for individual- and ecological-level covariates. MEASUREMENTS AND MAIN RESULTS: In single-pollutant models, we observed significant positive associations between O3, PM2.5, and NO2 concentrations and all-cause and cause-specific mortality. In two-pollutant models adjusted for PM2.5, significant positive associations remained between O3 and all-cause (hazard ratio [HR] per 10 ppb, 1.02; 95% confidence interval [CI], 1.01-1.04), circulatory (HR, 1.03; 95% CI, 1.01-1.05), and respiratory mortality (HR, 1.12; 95% CI, 1.08-1.16) that were unchanged with further adjustment for NO2. We also observed positive mortality associations with both PM2.5 (both near source and regional) and NO2 in multipollutant models. CONCLUSIONS: Findings derived from this large-scale prospective study suggest that long-term ambient O3 contributes to risk of respiratory and circulatory mortality. Substantial health and environmental benefits may be achieved by implementing further measures aimed at controlling O3 concentrations.M.C.T. was funded by a Government of Canada Banting Postdoctoral Fellowship. D.K. is the McLaughlin Chair in Risk Science at the University of Ottawa. Health Canada, the Centers for Disease Control and Prevention, and the National Institutes of Health funded the development of the PM2.5 exposure model. The American Cancer Society funded the creation, maintenance, and follow-up of the Cancer Prevention Study II cohort

Acetylsalicylic acid enhances purinergic receptor-mediated outward currents in rat megakaryocytes

Purinergic receptor activation increases cytosolic Ca2+ concentration in a fluctuating fashion, triggering oscillatory outward Ca2+-activated K+ currents in rat megakaryocytes (MKs). Whole cell and nystatin-perforated patch-clamp techniques were used to analyze changes in ionic conductance in MK with acetylsalicylic acid (ASA), a cyclooxygenase-1 inhibitor and antithrombotic agent. MKs are a model for platelet reactivity, particularly in ASA treatment failure (ASA resistance). Freshly isolated MKs were incubated 30 min in the absence or presence of 1 mM ASA. Using a K+-rich internal solution, we recorded outward currents in response to 10 μM ATP, 10 μM ADP, and 5 μM 2-methyl-thio-ADP (2MeSADP) in the voltage-clamp mode. Agonist-induced currents decreased in amplitude over time, but this decline was attenuated by ASA in both continuous and repeated agonist challenge, indicating increased MK reactivity with ASA treatment. In separate experiments, heterologous desensitization was observed when MKs were stimulated with ADP after exposure to a thromboxane receptor agonist (U46619), indicating cross talk between thromboxane and purinergic pathways. Different cells, treated with ASA or MRS2179 (P2Y1 receptor antagonist), were stimulated with 2MeSADP. The dose-response curve was shifted to the left in both cases, suggesting increased MK reactivity. ASA also caused an increased interval between currents (delay). ASA attenuated desensitization of purinergic receptors and increased delay, again suggesting cross talk between purinergic and thromboxane pathways. These findings may be relevant to ASA resistance, because individual variations in sensitivity to the multiple effects of ASA on signaling pathways could result in insensitivity to its antiplatelet effects in some patients

Development of a Canadian socioeconomic status index for the study of health outcomes related to environmental pollution

BACKGROUND: Socioeconomic status (SES) is an important determinant of health and potential modifier of the effects of environmental contaminants. There has been a lack of comprehensive indices for measuring overall SES in Canada. Here, a more comprehensive SES index is developed aiming to support future studies exploring health outcomes related to environmental pollution in Canada. METHODS: SES variables (n = 22, Census Canada 2006) were selected based on: cultural identities, housing characteristics, variables identified in Canadian environmental injustice studies and a previous deprivation index (Pampalon index). Principal component analysis with a single varimax rotation (factor loadings ≥ │60│) was performed on SES variables for 52974 census dissemination areas (DA). The final index was created by averaging the factor scores per DA according to the three components retained. The index was validated by examining its association with preterm birth (gestational age < 37 weeks), term low birth weight (LBW, <2500 g), small for gestational age (SGA, <10 percentile of birth weight for gestational age) and PM(2.5) (particulate matter ≤ 2.5 μm) exposures in Edmonton, Alberta (1999–2008). RESULTS: Index values exhibited a relatively normal distribution (median = 0.11, mean = 0.0, SD = 0.58) across Canada. Values in Alberta tended to be higher than in Newfoundland and Labrador, Northwest Territories and Nunavut (Pearson chi-square p < 0.001 across provinces). Lower quintiles of our index and the Pampalon’s index confirmed know associations with a higher prevalence of LBW, SGA, preterm birth and PM(2.5) exposure. Results with our index exhibited greater statistical significance and a more consistent gradient of PM(2.5) levels and prevalence of pregnancy outcomes. CONCLUSIONS: Our index reflects more dimensions of SES than an earlier index and it performed superiorly in capturing gradients in prevalence of pregnancy outcomes. It can be used for future research involving environmental pollution and health in Canada. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12889-015-1992-y) contains supplementary material, which is available to authorized users

Temporal aspects of air pollutant measures in epidemiologic analysis: a simulation study

Numerous observational studies have assessed the association between ambient air pollution and chronic disease incidence, but there is no uniform approach to create an exposure metric that captures the variability in air pollution through time and determines the most relevant exposure window. The purpose of the present study was to assess ways of modeling exposure to air pollution in relation to incident hypertension. We simulated data on incident hypertension to assess the performance of six air pollution exposure metrics, using characteristics from the Black Women’s Health Study. Each metric made different assumptions about how to incorporate time trends in pollutant data, and the most relevant window of exposure. We use observed values for particulate matter ≤2.5 microns (PM(2.5)) for this cohort to create the six exposure metrics and fit Cox proportional hazards models to the simulated data using the six metrics. The optimal exposure metric depends on the underlying association between PM(2.5) and disease, which is unknown. Metrics that incorporate exposure information from multiple years tend to be more robust and suffer from less bias. This study provides insight into factors that influence the metric used to quantifying exposure to PM(2.5) and suggests the need for careful sensitivity analyses