97 research outputs found
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Spatial Heterogeneity in the Effects of Immigration and Diversity on Neighborhood Homicide Rates
This article examines the connection of immigration and diversity to homicide by advancing a recently developed approach to modeling spatial dynamics—geographically weighted regression (GWR). In contrast to traditional global averaging, we argue on substantive grounds that neighborhood characteristics vary in their effects across neighborhood space, a process of “spatial heterogeneity.” Much like treatment-effect heterogeneity and distinct from spatial spillover, our analysis finds considerable evidence that neighborhood characteristics in Chicago vary significantly in predicting homicide, in some cases showing countervailing effects depending on spatial location. In general, however, immigrant concentration is either unrelated or inversely related to homicide, whereas language diversity is consistently linked to lower homicide. The results shed new light on the immigration-homicide nexus and suggest the pitfalls of global averaging models that hide the reality of a highly diversified and spatially stratified metropolis.Sociolog
Stereological analysis of liver biopsy histology sections as a reference standard for validating non-invasive liver fat fraction measurements by MRI
© 2016 St. Pierre et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background and Aims: Validation of non-invasive methods of liver fat quantification requires a reference standard. However, using standard histopathology assessment of liver biopsies is problematical because of poor repeatability. We aimed to assess a stereological method of measuring volumetric liver fat fraction (VLFF) in liver biopsies and to use the method to validate a magnetic resonance imaging method for measurement of VLFF. Methods: VLFFs were measured in 59 subjects (1) by three independent analysts using a stereological point counting technique combined with the Delesse principle on liver biopsy histological sections and (2) by three independent analysts using the HepaFat-Scan® technique on magnetic resonance images of the liver. Bland Altman statistics and intraclass correlation (IC) were used to assess the repeatability of each method and the bias between the methods of liver fat fraction measurement. Results: Inter-analyst repeatability coefficients for the stereology and HepaFat-Scan® methods were 8.2 (95% CI 7.7-8.8)% and 2.4 (95% CI 2.2-2.5)% VLFF respectively. IC coefficients were 0.86 (95% CI 0.69-0.93) and 0.990 (95% CI 0.985-0.994) respectively. Small biases (=3.4%) were observable between two pairs of analysts using stereology while no significant biases were observable between any of the three pairs of analysts using Hepa-Fat-Scan®. A bias of 1.4±0.5% VLFF was observed between the HepaFat-Scan® method and the stereological method. Conclusions: Repeatability of the stereological method is superior to the previously reported performance of assessment of hepatic steatosis by histopathologists and is a suitable reference standard for validating non-invasive methods of measurement of VLFF
Secondary Endoleak Management Following TEVAR and EVAR.
Endovascular abdominal and thoracic aortic aneurysm repair and are widely used to treat increasingly complex aneurysms. Secondary endoleaks, defined as those detected more than 30Â days after the procedure and after previous negative imaging, remain a challenge for aortic specialists, conferring a need for long-term surveillance and reintervention. Endoleaks are classified on the basis of their anatomic site and aetiology. Type 1 and type 2 endoleaks (EL1 and EL2) are the most common endoleaks necessitating intervention. The management of these requires an understanding of their mechanics, and the risk of sac enlargement and rupture due to increased sac pressure. Endovascular techniques are the main treatment approach to manage secondary endoleaks. However, surgery should be considered where endovascular treatments fail to arrest aneurysm growth. This chapter reviews the aetiology, significance, management strategy and techniques for different endoleak types
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
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Transthoracic needle biopsy of lung masses: a survey of techniques
In order to assess the range and everyday use of the various techniques for percutaneous transthoracic needle biopsy of lung masses in the USA and Canada, we surveyed thoracic radiologists in academic and community practice on their standard approach to the procedure.
The 300 questionnaires that were mailed to members of the Society of Thoracic Radiology throughout the USA and Canada contained specific questions on their approach to a transthoracic needle biopsy of a routine case of a 3
cm lung mass located in the right lower lobe 1
cm from the pleural surface.
A total of 140 (47%) members responded. Of the 139 responders who performed lung biopsies, 103 (74%) were located at a teaching centre affiliated to a university or medical school, and 36 (26%) were community-based radiologists. In total 97 (70%) replied that they would perform the procedure under CT guidance, 31 (22%) under either CT or fluoroscopy guidance, and 11 (8%) only under fluoroscopy. Fine-needle aspiration was the procedure of choice for the given case by 101 (73%) responders, whereas 20 (14%) preferred doing core biopsy, and 18 (13%) chose both techniques. On-site cytology confirmation for obtaining diagnostic material was available to 101 (73%) responders. Before performing the procedure, 107 (77%) verified coagulation tests whereas 32 (23%) did not. Follow-up imaging for pneumothorax assessment was not routinely performed by 15 (11%) responders.
The majority of radiologists performed percutaneous transthoracic needle biopsy of a lung mass under CT guidance, by fine-needle aspiration, using repeated pleural puncture technique, and with a cytologist on site. A significant minority did not obtain coagulation screening before the procedure, and a small minority did not routinely assess for pneumothorax by late chest radiography
DIFFERENCE IN PHYSICAL ACTIVITY BETWEEN CHILDREN WITHOUT SIBLINGS AND WITH SIBLINGS
Chelsea L. SmithƗ1, Emily Gusemanǂ2, Laura Hubbs-Taitǂ3, Jennifer Graefǂ1, Sandra Arnoldǂ1, Allen Knehansǂ1, & Susan B. Sisson ǂ1, FACSM 1University of Oklahoma Health Sciences Center, 2Ohio University, 3Oklahoma State University
Children without siblings, singletons, have higher rates of obesity than children with siblings, non-singletons. Physical activity, such as increased moderate-to-vigorous physical activity (MVPA) and decreased sedentary behavior, can curb excess weight gain early in life.
PURPOSE: The purpose of this study is to examine the differences in physical activity and sedentary behavior between singleton and non-singleton children. METHODS: Mothers of singleton children ages 5.0-7.9 years old and mothers of non-singleton children ages 5.0-7.9 years old with a sibling between the ages of 2.0-4.9 years old in their primary household were recruited. Height, weight, and waist circumference (WC) of child were objectively measured. Mothers reported demographic characteristics of the child and self, and completed a questionnaire on their physical activity. Children wore an accelerometer at the ankle for at least 5 full days while parents recorded daily activities and time spent in away from home care (such as child care or kindergarten). Body mass index (BMI) was calculated, and BMI and WC percentiles were calculated for age and sex. MVPA and sedentary behavior per hour were calculated using accelerometer cut points and total wear time. RESULTS: 40 mother-child dyads (8 singletons and 32 non-singletons) participated. On average mothers were 34.7 years old, employed full time (62%), married (80%), and the child’s biological mothers (97%); while children were 6.16 years old and predominantly white (75%). Singletons had a higher BMI percentile (74.9±19.2) and waist circumference percentile (73.2±19.8) compared to non-singletons (52.9±28.6, p=0.02; 52.8±21.3, p\u3c0.01). In individual models, singletons did not differ in time away from home care (p=0.60) or in their mother’s average MET minutes per week compared to non-singleton children (p=0.90). After adjusting for child BMI percentile and month of wear, singletons spent 3.03 less minutes per hour in MVPA (p\u3c0.01) and 3.98 more minutes per hour in sedentary behavior compared to non-singletons (p=0.01). CONCLUSION: In this sample, singletons had a higher BMI percentile and were less active compared to non-singletons. Investigation into differences in singleton/non-singleton families, including family health behaviors, may support understanding of the mechanism
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