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Find video protocols related to scientific articles indexed in Pubmed.
Asthma & Allergy Development: Contrasting Influences of Yeasts & Other Fungal Exposures.
Clin. Exp. Allergy
PUBLISHED: 09-10-2014
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Infancy is a developmental stage with heightened susceptibility to environmental influences on the risk of chronic childhood disease. Few birth cohort studies have detailed measures of fungal diversity data in infants' bedrooms, limiting the potential to measure long-term associations of these complex exposures with development of asthma or allergy.
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Long-term exposure to ambient air pollution and serum leptin in older adults: results from the MOBILIZE Boston study.
J. Occup. Environ. Med.
PUBLISHED: 09-06-2014
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Long-term exposure to traffic-related air pollution has been linked to increased risk of obesity and diabetes and may be associated with higher serum levels of the adipokine leptin, but this hypothesis has not been previously evaluated in humans.
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Short-term exposure to air pollution and digital vascular function.
Am. J. Epidemiol.
PUBLISHED: 08-05-2014
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We investigated associations between ambient air pollution and microvessel function measured by peripheral arterial tonometry between 2003 and 2008 in the Framingham Heart Study Offspring and Third Generation Cohorts. We measured particulate matter with aerodynamic diameter ?2.5 µm (PM2.5), black carbon, sulfates, particle number, nitrogen oxides, and ozone by using fixed monitors, and we determined moving averages for 1-7 days preceding vascular testing. We examined associations between these exposures and hyperemic response to ischemia and baseline pulse amplitude, a measure of arterial tone (n = 2,369). Higher short-term exposure to air pollutants, including PM2.5, black carbon, and particle number was associated with higher baseline pulse amplitude. For example, higher 3-day average PM2.5 exposure was associated with 6.3% higher baseline pulse amplitude (95% confidence interval: 2.0, 10.9). However, there were no consistent associations between the air pollution exposures assessed and hyperemic response. Our findings in a community-based sample exposed to relatively low pollution levels suggest that short-term exposure to ambient particulate pollution is not associated with vasodilator response, but that particulate air pollution is associated with baseline pulse amplitude, suggesting potentially adverse alterations in baseline vascular tone or compliance.
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Batting cage performance of wood and nonwood youth baseball bats.
J Appl Biomech
PUBLISHED: 08-02-2014
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The purpose of this study was to examine the batting cage performance of wood and nonwood baseball bats used at the youth level. Three wood and ten nonwood bats were swung by 22 male players (13 to 18 years old) in a batting cage equipped with a 3-dimensional motion capture (300 Hz) system. Batted ball speeds were compared using a one-way ANOVA and bat swing speeds were analyzed as a function of bat moment of inertia by linear regression. Batted ball speeds were significantly faster for three nonwood bat models (P<.001), significantly slower for one nonwood model, and not different for six nonwood bats when compared with wood bats. Bat impact speed significantly (P<.05) decreased with increasing bat moment of inertia for the 13-, 14-, and 15-year-old groups, but not for the other age groups. Ball-bat coefficients of restitution (BBCOR) for all nonwood were greater than for wood, but this factor alone did not correlate with bat performance. Our findings indicate that increases in BBCOR and swing speed were not associated with faster batted ball speeds for the bats studied whose moment of inertia was substantially less than that of a wood bat of similar length.
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Ambient particulate air pollution and microRNAs in elderly men.
Epidemiology
PUBLISHED: 07-31-2014
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Ambient particulate matter (PM) has been associated with mortality and morbidity for cardiovascular disease. MicroRNAs control gene expression at a posttranscriptional level. Altered microRNA expression has been reported in processes related to cardiovascular disease and PM exposure, such as systemic inflammation, endothelial dysfunction, and atherosclerosis. Polymorphisms in microRNA-related genes could influence response to PM.
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Long-term effects of traffic particles on lung function decline in the elderly.
Am. J. Respir. Crit. Care Med.
PUBLISHED: 07-17-2014
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Few studies have been performed on air pollution effects on lung function in the elderly, a vulnerable population with low reserve capacity, and even fewer have looked at changes in the rate of lung function decline.
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Controlling for seasonal patterns and time varying confounders in time-series epidemiological models: a simulation study.
Stat Med
PUBLISHED: 06-30-2014
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An important topic when estimating the effect of air pollutants on human health is choosing the best method to control for seasonal patterns and time varying confounders, such as temperature and humidity. Semi-parametric Poisson time-series models include smooth functions of calendar time and weather effects to control for potential confounders. Case-crossover (CC) approaches are considered efficient alternatives that control seasonal confounding by design and allow inclusion of smooth functions of weather confounders through their equivalent Poisson representations. We evaluate both methodological designs with respect to seasonal control and compare spline-based approaches, using natural splines and penalized splines, and two time-stratified CC approaches. For the spline-based methods, we consider fixed degrees of freedom, minimization of the partial autocorrelation function, and general cross-validation as smoothing criteria. Issues of model misspecification with respect to weather confounding are investigated under simulation scenarios, which allow quantifying omitted, misspecified, and irrelevant-variable bias. The simulations are based on fully parametric mechanisms designed to replicate two datasets with different mortality and atmospheric patterns. Overall, minimum partial autocorrelation function approaches provide more stable results for high mortality counts and strong seasonal trends, whereas natural splines with fixed degrees of freedom perform better for low mortality counts and weak seasonal trends followed by the time-season-stratified CC model, which performs equally well in terms of bias but yields higher standard errors. Copyright © 2014 John Wiley & Sons, Ltd.
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Acclimatization across space and time in the effects of temperature on mortality: a time-series analysis.
Environ Health
PUBLISHED: 06-13-2014
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Climate change has increased the days of unseasonal temperature. Although many studies have examined the association between temperature and mortality, few have examined the timing of exposure where whether this association varies depending on the exposure month even at the same temperature. Therefore, we investigated monthly differences in the effects of temperature on mortality in a study comprising a wide range of weather and years, and we also investigated heterogeneity among regions.
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Association between length of gestation and cervical DNA methylation of PTGER2 and LINE 1-HS.
Epigenetics
PUBLISHED: 05-14-2014
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Worldwide, more than 1 in 10 infants is born prior to 37 weeks gestation. Preterm birth can lead to increased mortality risk and poor life-long health and neurodevelopmental outcomes. Whether environmental risk factors affect preterm birth through epigenetic phenomena is largely unstudied. We sought to determine whether preterm risk factors, such as smoke exposure and education, were associated with cervical DNA methylation in the prostaglandin E receptor 2 gene (PTGER2) and a repetitive element, long interspersed nuclear element-1 Homo sapiens-specific (LINE 1-HS). Second, we aimed to determine whether mid-pregnancy DNA methylation of these regions in cervical samples could predict the length of gestation. We obtained a cervical swab between 16-19 weeks gestation from 80 women participating in a Mexico City birth cohort, used pyrosequencing to analyze DNA methylation of PTGER2 and LINE 1-HS, and examined associations with maternal covariates. We used accelerated failure time models to analyze associations of DNA methylation with the length of gestation. DNA methylation of both sequences was associated with Pap smear inflammation. LINE 1-HS methylation was associated with smoke exposure, BMI and parity. In adjusted models, gestations were 3.3 days longer (95%CI 0.6, 6.0) for each interquartile range of PTGER2 DNA methylation. Higher LINE 1-HS methylation was associated with shorter gestations (-3.3 days, 95%CI -6.5, -0.2). In conclusion, cervical DNA methylation was associated with risk factors for preterm birth and the length of gestation.
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Effects of temperature and relative humidity on DNA methylation.
Epidemiology
PUBLISHED: 05-10-2014
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Previous studies have found relationships between DNA methylation and various environmental contaminant exposures. Associations with weather have not been examined. Because temperature and humidity are related to mortality even on non-extreme days, we hypothesized that temperature and relative humidity may affect methylation.
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Short-term airborne particulate matter exposure alters the epigenetic landscape of human genes associated with the mitogen-activated protein kinase network: a cross-sectional study.
Environ Health
PUBLISHED: 05-02-2014
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Exposure to air particulate matter is known to elevate blood biomarkers of inflammation and to increase cardiopulmonary morbidity and mortality. Major components of airborne particulate matter typically include black carbon from traffic and sulfates from coal-burning power plants. DNA methylation is thought to be sensitive to these environmental toxins and possibly mediate environmental effects on clinical outcomes via regulation of gene networks. The underlying mechanisms may include epigenetic modulation of major inflammatory pathways, yet the details remain unclear.
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Consequences of kriging and land use regression for PM2.5 predictions in epidemiologic analyses: insights into spatial variability using high-resolution satellite data.
J Expo Sci Environ Epidemiol
PUBLISHED: 04-29-2014
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Many epidemiological studies use predicted air pollution exposures as surrogates for true air pollution levels. These predicted exposures contain exposure measurement error, yet simulation studies have typically found negligible bias in resulting health effect estimates. However, previous studies typically assumed a statistical spatial model for air pollution exposure, which may be oversimplified. We address this shortcoming by assuming a realistic, complex exposure surface derived from fine-scale (1?km × 1?km) remote-sensing satellite data. Using simulation, we evaluate the accuracy of epidemiological health effect estimates in linear and logistic regression when using spatial air pollution predictions from kriging and land use regression models. We examined chronic (long-term) and acute (short-term) exposure to air pollution. Results varied substantially across different scenarios. Exposure models with low out-of-sample R(2) yielded severe biases in the health effect estimates of some models, ranging from 60% upward bias to 70% downward bias. One land use regression exposure model with >0.9 out-of-sample R(2) yielded upward biases up to 13% for acute health effect estimates. Almost all models drastically underestimated the SEs. Land use regression models performed better in chronic effect simulations. These results can help researchers when interpreting health effect estimates in these types of studies.Journal of Exposure Science and Environmental Epidemiology advance online publication, 4 June 2014; doi:10.1038/jes.2014.40.
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Influence of multiple APOE genetic variants on cognitive function in a cohort of older men - results from the Normative Aging Study.
BMC Psychiatry
PUBLISHED: 04-20-2014
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APOE is the biomarker with the greatest known influence on cognitive function; however, the effect of complex haplotypes involving polymorphisms rs449647, rs405509, rs440446, rs429358 and rs7412 has never been studied in older populations.
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Traffic-related air pollution and sleep in the Boston Area Community Health Survey.
J Expo Sci Environ Epidemiol
PUBLISHED: 04-18-2014
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Little is known about environmental determinants of sleep. We investigated the association between black carbon (BC), a marker of traffic-related air pollution, and sleep measures among participants of the Boston Area Community Health Survey. We also sought to assess the impact of sociodemographic factors, health conditions, and season on associations. Residential 24-h BC was estimated from a validated land-use regression model for 3821 participants and averaged over 1-6 months and 1 year. Sleep measures included questionnaire-assessed sleep duration, sleep latency, and sleep apnea. Linear and logistic regression models controlling for confounders estimated the association between sleep measures and BC. Effect modification was tested with interaction terms. Main effects were not observed between BC and sleep measures. However, in stratified models, males experienced 0.23?h less sleep (95% CI: -0.42, -0.03) and those with low SES 0.25?h less sleep (95% CI: -0.48, -0.01) per IQR increase in annual BC (0.21??g/m(3)). In blacks, sleep duration increased with annual BC (?=0.34 per IQR; 95% CI: 0.12, 0.57). Similar findings were observed for short sleep (?5?h). BC was not associated with sleep apnea or sleep latency, however, long-term exposure may be associated with shorter sleep duration, particularly in men and those with low SES, and longer sleep duration in blacks.Journal of Exposure Science and Environmental Epidemiology advance online publication, 2 July 2014; doi:10.1038/jes.2014.47.
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Health effects of multi-pollutant profiles.
Environ Int
PUBLISHED: 04-15-2014
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The association between exposure to particle mass and mortality is well established; however, there are still uncertainties as to whether certain chemical components are more harmful than others. Moreover, understanding the health effects associated with exposure to pollutant mixtures may lead to new regulatory strategies.
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Occupational determinants of cumulative lead exposure: analysis of bone lead among men in the VA normative aging study.
J. Occup. Environ. Med.
PUBLISHED: 04-09-2014
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To examine the relation between occupation and cumulative lead exposure-assessed by measuring bone lead-in a community-dwelling population.
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Relation of long-term exposure to air pollution to brachial artery flow-mediated dilation and reactive hyperemia.
Am. J. Cardiol.
PUBLISHED: 03-20-2014
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Long-term exposure to ambient air pollution has been associated with cardiovascular morbidity and mortality. Impaired vascular responses may, in part, explain these findings, but the association of such long-term exposure with measures of both conduit artery and microvascular function has not been widely reported. We evaluated the association between residential proximity to a major roadway (primary or secondary highway) and spatially resolved average fine particulate matter (PM2.5) and baseline brachial artery diameter and mean flow velocity, flow-mediated dilation%, and hyperemic flow velocity, in the Framingham Offspring and Third Generation Cohorts. We examined 5,112 participants (2,731 [53%] women, mean age 49 ± 14 years). Spatially resolved average PM2.5 was associated with lower flow-mediated dilation% and hyperemic flow velocity. An interquartile range difference in PM2.5 (1.99 ?g/m(3)) was associated with -0.16% (95% confidence interval [CI] -0.27%, -0.05%) lower flow-mediated dilation% and -0.72 (95% CI -1.38, -0.06) cm/s lower hyperemic flow velocity%. Residential proximity to a major roadway was negatively associated with flow-mediated dilation%. Compared with living ?400 m away, living <50 m from a major roadway was associated with 0.32% lower flow-mediated dilation (95% CI -0.58%, -0.06%), but results for hyperemic flow velocity had wide confidence intervals -0.68 cm/s (95% CI -2.29, 0.93). In conclusion, residential proximity to a major roadway and higher levels of spatially resolved estimates of PM2.5 at participant residences are associated with impaired conduit artery and microvascular function in this large community-based cohort of middle-aged and elderly adults.
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Ozone trends and their relationship to characteristic weather patterns.
J Expo Sci Environ Epidemiol
PUBLISHED: 03-14-2014
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Local trends in ozone concentration may differ by meteorological conditions. Furthermore, the trends occurring at the extremes of the Ozone distribution are often not reported even though these may be very different than the trend observed at the mean or median and they may be more relevant to health outcomes. Classify days of observation over a 16-year period into broad categories that capture salient daily local weather characteristics. Determine the rate of change in mean and median O3 concentrations within these different categories to assess how concentration trends are impacted by daily weather. Further examine if trends vary for observations in the extremes of the O3 distribution. We used k-means clustering to categorize days of observation based on the maximum daily temperature, standard deviation of daily temperature, mean daily ground level wind speed, mean daily water vapor pressure and mean daily sea-level barometric pressure. The five cluster solution was determined to be the appropriate one based on cluster diagnostics and cluster interpretability. Trends in cluster frequency and pollution trends within clusters were modeled using Poisson regression with penalized splines as well as quantile regression. There were five characteristic groupings identified. The frequency of days with large standard deviations in hourly temperature decreased over the observation period, whereas the frequency of warmer days with smaller deviations in temperature increased. O3 trends were significantly different within the different weather groupings. Furthermore, the rate of O3 change for the 95th percentile and 5th percentile was significantly different than the rate of change of the median for several of the weather categories.We found that O3 trends vary between different characteristic local weather patterns. O3 trends were significantly different between the different weather groupings suggesting an important interaction between changes in prevailing weather conditions and O3 concentration.Journal of Exposure Science and Environmental Epidemiology advance online publication, 9 July 2014; doi:10.1038/jes.2014.45.
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Air pollution exposure and lung function in highly exposed subjects in Beijing, China: a repeated-measure study.
Part Fibre Toxicol
PUBLISHED: 03-03-2014
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BackgroundExposure to ambient particulate matter (PM) has been associated with reduced lung function. Elemental components of PM have been suggested to have critical roles in PM toxicity, but their contribution to respiratory effects remains under-investigated. We evaluated the effects of traffic-related PM2.5 and its elemental components on lung function in two highly exposed groups of healthy adults in Beijing, China.MethodsThe Beijing Truck-Driver Air Pollution Study (BTDAS) included 60 truck drivers and 60 office workers evaluated in 2008. On two days separated by 1-2 weeks, we measured lung function at the end of the work day, personal PM2.5, and nine elemental components of PM2.5 during eight hours of work, i.e., elemental carbon (EC), potassium (K), sulfur (S), iron (Fe), silicon (Si), aluminum (Al), zinc (Zn), calcium (Ca), and titanium (Ti). We used covariate-adjusted mixed-effects models including PM2.5 as a covariate to estimate the percentage change in lung function associated with an inter-quartile range (IQR) exposure increase.ResultsThe two groups had high and overlapping exposure distributions with mean personal PM2.5 of 94.6 ¿g/m3 (IQR: 48.5-126.6) in office workers and 126.8 ¿g/m3 (IQR: 73.9-160.5) in truck drivers. The distributions of the nine elements showed group-specific profiles and generally higher levels in truck drivers. In all subjects combined, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) did not significantly correlate with PM2.5. However, FEV1 showed negative association with concentrations of four elements: Si (-3.07%, 95%CI: -5.00; -1.11, IQR: 1.54), Al (-2.88%, 95%CI: -4.91; -0.81, IQR: 0.86), Ca (-1.86%, 95%CI: -2.95; -0.76, IQR: 1.33), and Ti (-2.58%, 95%CI: -4.44; -0.68, IQR: 0.03), and FVC showed negative association with concentrations of three elements: Si (-3.23%, 95%CI: -5.61; -0.79), Al (-3.26%, 95%CI: -5.73; -0.72), and Ca (-1.86%, 95%CI: -3.23; -0.47). In stratified analysis, Si, Al, Ca, and Ti showed associations with lung function only among truck drivers, and no significant association among office workersConclusionSelected elemental components of PM2.5 showed effects on lung function that were not found in analyses of particle levels alone.
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Increasing CO2 threatens human nutrition.
Nature
PUBLISHED: 02-24-2014
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Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies, causing a loss of 63?million life-years annually. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health.
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Mitochondrial haplogroups modify the effect of black carbon on age-related cognitive impairment.
Environ Health
PUBLISHED: 02-12-2014
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Traffic-related air pollution has been linked with impaired cognition in older adults, possibly due to effects of oxidative stress on the brain. Mitochondria are the main source of cellular oxidation. Haplogroups in mitochondrial DNA (mtDNA) mark individual differences in oxidative potential and are possible determinants of neurodegeneration. The aim of this study was to investigate whether mtDNA haplogroups determined differential susceptibility to cognitive effects of long-term exposure to black carbon (BC), a marker of traffic-related air pollution.
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Respiratory and sensory irritation symptoms among residents exposed to low-to-moderate air pollution from biodegradable wastes.
J Expo Sci Environ Epidemiol
PUBLISHED: 02-10-2014
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Previous studies have reported increased occurrence of respiratory and sensory irritation symptoms among residents living close to biodegradable waste sites. However, few studies have been able to quantify direct and annoyance-mediated effects based on individual-specific assessments of chemical exposures. We examined associations between residential exposures to a proxy gas (ammonia, NH3) from biodegradable wastes (mainly from farming, animal and agricultural activities) and odor annoyance and six respiratory and sensory irritation symptoms (self-reported), using adjusted logistic regression models and mediation analyses. Individual-specific NH3 exposures (n=454) in residential environments during 2005-2010 were calculated by the Danish Eulerian long-range transport model and the local-scale transport deposition model. Residential NH3 exposure was associated with increased frequency of four symptoms, including "eyes itching, dryness or irritation" and "cough" (ORadj=1.69; 95% CI: 1.09-2.61 and ORadj=1.75; 95% CI: 1.12-2.74, for each unit increase in loge(NH3 exposure)). Odor annoyance mediated the effect of exposure on cough and three sensory irritation symptoms. Mediation was either full (indirect-only effects) or partial (direct and indirect effects). This study provides support for the existence of indirect associations between residential exposures to low-to-moderate air pollution from wastes and symptoms, as well as direct dose-response associations for some of the symptoms.
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The impact of source contribution uncertainty on the effects of source-specific PM2.5 on hospital admissions: a case study in Boston, MA.
J Expo Sci Environ Epidemiol
PUBLISHED: 02-05-2014
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Epidemiologic studies of particulate sources and adverse health do not account for the uncertainty in the source contribution estimates. Our goal was to assess the impact of uncertainty on the effect estimates of particulate sources on emergency cardiovascular (CVD) admissions. We examined the effects of PM2.5 sources, identified by positive matrix factorization (PMF) and absolute principle component analysis (APCA), on emergency CVD hospital admissions among Medicare enrollees in Boston, MA, during 2003-2010, given stronger associations for this period. We propagated uncertainty in source contributions using a block bootstrap procedure. We further estimated average across-methods source-specific effect estimates using bootstrap samples. We estimated contributions for regional, mobile, crustal, residual oil combustion, road dust, and sea salt sources. Accounting for uncertainty, same-day exposures to regional pollution were associated with an across-methods average effect of 2.00% (0.18, 3.78%) increase in the rate of CVD admissions. Weekly residual oil exposures resulted in an average 2.12% (0.19, 4.22%) increase. Same-day and 2-day exposures to mobile-related PM2.5 were also associated with increased admissions. Confidence intervals when accounting for the uncertainty were wider than otherwise. Agreement in PMF and APCA results was stronger when uncertainty was considered in health models. Accounting for uncertainty in source contributions leads to more stable effect estimates across methods and potentially to fewer spurious significant associations.
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Exposure to traffic and early life respiratory infection: A cohort study.
Pediatr. Pulmonol.
PUBLISHED: 01-29-2014
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We examined whether proximity to a major roadway and traffic density around the home during pregnancy are associated with risk of early life respiratory infection in a pre-birth cohort in the Boston area. We geocoded addresses for 1,263 mother-child pairs enrolled during the first trimester of pregnancy in Project Viva during 1999-2002. We calculated distance from home to nearest major roadway and traffic density in a 100?m buffer around the home. We defined respiratory infection as maternal report of ?1 doctor-diagnosed pneumonia, bronchiolitis, croup, or other respiratory infection from birth until the early childhood visit (median age 3.3). We used relative risk regression models adjusting for potential confounders to estimate associations between traffic exposures and risk of respiratory infection. Distance to roadway during pregnancy was associated with risk of respiratory infection. In fully adjusted models, relative risks (95% CI) for respiratory infection were: 1.30 (1.08, 1.55) for <100?m, 1.15 (0.93, 1.41) for 100 to <200?m, and 0.95 (0.84, 1.07) for 200 to <1,000?m compared with living ?1,000?m away from a major roadway. Each interquartile range increase in distance to roadway was associated with an 8% (95% CI 0.87, 0.98) lower risk, and each interquartile range increase in traffic density was associated with a 5% (95% CI 0.98, 1.13) higher risk of respiratory infection. Our findings suggest that living close to a major roadway during pregnancy may predispose the developing lung to infection in early life. Pediatr Pulmonol. © 2014 Wiley Periodicals, Inc.
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Lead exposure and rate of change in cognitive function in older women.
Environ. Res.
PUBLISHED: 01-29-2014
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Higher long-term cumulative lead exposure predicts faster cognitive decline in older men, but evidence of an association in women is lacking.
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Short-term effects of air pollution on oxygen saturation in a cohort of senior adults in Steubenville, Ohio.
J. Occup. Environ. Med.
PUBLISHED: 01-24-2014
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We examine whether ambient air pollution is associated with oxygen saturation in 32 elderly subjects in Steubenville, Ohio.
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Predicting DNA methylation level across human tissues.
Nucleic Acids Res.
PUBLISHED: 01-20-2014
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Differences in methylation across tissues are critical to cell differentiation and are key to understanding the role of epigenetics in complex diseases. In this investigation, we found that locus-specific methylation differences between tissues are highly consistent across individuals. We developed a novel statistical model to predict locus-specific methylation in target tissue based on methylation in surrogate tissue. The method was evaluated in publicly available data and in two studies using the latest IlluminaBeadChips: a childhood asthma study with methylation measured in both peripheral blood leukocytes (PBL) and lymphoblastoid cell lines; and a study of postoperative atrial fibrillation with methylation in PBL, atrium and artery. We found that our method can greatly improve accuracy of cross-tissue prediction at CpG sites that are variable in the target tissue [R(2) increases from 0.38 (original R(2) between tissues) to 0.89 for PBL-to-artery prediction; from 0.39 to 0.95 for PBL-to-atrium; and from 0.81 to 0.98 for lymphoblastoid cell line-to-PBL based on cross-validation, and confirmed using cross-study prediction]. An extended model with multiple CpGs further improved performance. Our results suggest that large-scale epidemiology studies using easy-to-access surrogate tissues (e.g. blood) could be recalibrated to improve understanding of epigenetics in hard-to-access tissues (e.g. atrium) and might enable non-invasive disease screening using epigenetic profiles.
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Effects of short-term exposure to inhalable particulate matter on DNA methylation of tandem repeats.
Environ. Mol. Mutagen.
PUBLISHED: 01-06-2014
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There is compelling evidence that particulate matter (PM) increases lung cancer risk by triggering systemic inflammation, and leukocyte DNA hypomethylation. However, previous investigations focused on repeated element sequences from LINE-1 and Alu families. Tandem repeats, which display a greater propensity to mutate, and are often hypomethylated in cancer patients, have never been investigated in individuals exposed to PM. We measured methylation of three tandem repeats (SAT?, NBL2, and D4Z4) by polymerase chain reaction-pyrosequencing on blood samples from truck drivers and office workers (60 per group) in Beijing, China. We used lightweight monitors to measure personal PM2.5 (PM with aerodynamic diameter ?2.5 µm) and elemental carbon (a tracer of PM from vehicular traffic). Ambient PM10 data were obtained from air quality measuring stations. Overall, an interquartile increase in personal PM2.5 and ambient PM10 levels was associated with a significant covariate-adjusted decrease in SAT? methylation (-1.35% 5-methyl cytosine [5mC], P = 0.01; and -1.33%5mC; P = 0.01, respectively). Effects from personal PM2.5 and ambient PM10 on SAT? methylation were stronger in truck drivers (-2.34%5mC, P = 0.02; -1.44%5mC, P = 0.06) than office workers (-0.95%5mC, P = 0.26; -1.25%5mC, P = 0.12, respectively). Ambient PM10 was negatively correlated with NBL2 methylation in truck drivers (-1.38%5mC, P = 0.03) but not in office workers (1.04%5mC, P = 0.13). Our result suggests that PM exposure is associated with hypomethylation of selected tandem repeats. Measuring tandem-repeat hypomethylation in easy-to-obtain blood specimens might identify individuals with biological effects and potential cancer risk from PM exposure.
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Pessimistic orientation in relation to telomere length in older men: the VA normative aging study.
Psychoneuroendocrinology
PUBLISHED: 01-02-2014
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Recent research suggests pessimistic orientation is associated with shorter leukocyte telomere length (LTL). However, this is the first study to look not only at effects of pessimistic orientation on average LTL at multiple time points, but also at effects on the rate of change in LTL over time.
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Air pollution and gene-specific methylation in the Normative Aging Study: association, effect modification, and mediation analysis.
Epigenetics
PUBLISHED: 01-02-2014
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The mechanisms by which air pollution has multiple systemic effects in humans are not fully elucidated, but appear to include inflammation and thrombosis. This study examines whether concentrations of ozone and components of fine particle mass are associated with changes in methylation on tissue factor (F3), interferon gamma (IFN-?), interleukin 6 (IL-6), toll-like receptor 2 (TLR-2), and intercellular adhesion molecule 1 (ICAM-1). We investigated associations between air pollution exposure and gene-specific methylation in 777 elderly men participating in the Normative Aging Study (1999-2009). We repeatedly measured methylation at multiple CpG sites within each gene's promoter region and calculated the mean of the position-specific measurements. We examined intermediate-term associations between primary and secondary air pollutants and mean methylation and methylation at each position with distributed-lag models. Increase in air pollutants concentrations was significantly associated with F3, ICAM-1, and TLR-2 hypomethylation, and IFN-? and IL-6 hypermethylation. An interquartile range increase in black carbon concentration averaged over the four weeks prior to assessment was associated with a 12% reduction in F3 methylation (95% CI: -17% to -6%). For some genes, the change in methylation was observed only at specific locations within the promoter region. DNA methylation may reflect biological impact of air pollution. We found some significant mediated effects of black carbon on fibrinogen through a decrease in F3 methylation, and of sulfate and ozone on ICAM-1 protein through a decrease in ICAM-1 methylation.
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The association of meningococcal disease with influenza in the United States, 1989-2009.
PLoS ONE
PUBLISHED: 01-01-2014
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Prior influenza infection is a risk factor for invasive meningococcal disease. Quantifying the fraction of meningococcal disease attributable to influenza could improve understanding of viral-bacterial interaction and indicate additional health benefits to influenza immunization.
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Associations between changes in city and address specific temperature and QT interval--the VA Normative Aging Study.
PLoS ONE
PUBLISHED: 01-01-2014
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The underlying mechanisms of the association between ambient temperature and cardiovascular morbidity and mortality are not well understood, particularly for daily temperature variability. We evaluated if daily mean temperature and standard deviation of temperature was associated with heart rate-corrected QT interval (QTc) duration, a marker of ventricular repolarization in a prospective cohort of older men.
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A novel genetic score approach using instruments to investigate interactions between pathways and environment: application to air pollution.
PLoS ONE
PUBLISHED: 01-01-2014
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Air pollution has been associated with increased systemic inflammation markers. We developed a new pathway analysis approach to investigate whether gene variants within relevant pathways (oxidative stress, endothelial function, and metal processing) modified the association between particulate air pollution and fibrinogen, C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Our study population consisted of 822 elderly participants of the Normative Aging Study (1999-2011). To investigate the role of biological mechanisms and to reduce the number of comparisons in the analysis, we created pathway-specific scores using gene variants related to each pathway. To select the most appropriate gene variants, we used the least absolute shrinkage and selection operator (Lasso) to relate independent outcomes representative of each pathway (8-hydroxydeoxyguanosine for oxidative stress, augmentation index for endothelial function, and patella lead for metal processing) to gene variants. A high genetic score corresponds to a higher allelic risk profile. We fit mixed-effects models to examine modification by the genetic score of the weekly air pollution association with the outcome. Among participants with higher genetic scores within the oxidative stress pathway, we observed significant associations between particle number and fibrinogen, while we did not find any association among participants with lower scores (p(interaction)?=?0.04). Compared to individuals with low genetic scores of metal processing gene variants, participants with higher scores had greater effects of particle number on fibrinogen (p(interaction)?=?0.12), CRP (p(interaction)?=?0.02), and ICAM-1 (pinteraction?=?0.08). This two-stage penalization method is easy to implement and can be used for large-scale genetic applications.
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Short-term changes in ambient temperature and risk of ischemic stroke.
Cerebrovasc Dis Extra
PUBLISHED: 01-01-2014
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Despite consistent evidence of a higher short-term risk of cardiovascular mortality associated with ambient temperature, there have been discrepant findings on the association between temperature and ischemic stroke. Moreover, few studies have considered potential confounding by ambient fine particulate matter air pollution <2.5 ?m in diameter (PM2.5) and none have examined the impact of temperature changes on stroke in the subsequent hours rather than days. The aim of this study was to evaluate whether changes in temperature trigger an ischemic stroke in the following hours and days and whether humid days are particularly harmful.
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Drinking water quality and hospital admissions of elderly people for gastrointestinal illness in Eastern Massachusetts, 1998-2008.
Water Res.
PUBLISHED: 01-01-2014
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We used a Poisson regression to compare daily hospital admissions of elderly people for acute gastrointestinal illness in Boston against daily variations in drinking water quality over an 11-year period, controlling for weather, seasonality and time trends. The Massachusetts Water Resources Authority (MWRA), which provides non-filtered water to 1.5 million people in the greater Boston area, changed its disinfection method from chlorination to ozonation during the study period so we were also able to evaluate changes in risk associated with the change in disinfection method. Other available water quality data from the MWRA included turbidity, fecal coliforms, UV-absorbance, and planktonic algae and cyanobacteriae concentrations. Daily weather, rainfall data and water temperature were also available. Low water temperature, increases in turbidity and, to a lesser extent, in fecal coliform and cyanobacteriae were associated with a higher risk of hospital admissions, while the shift from chlorination to ozonation has possibly reduced the health risk. The MWRA complied with US drinking water regulations throughout the study period.
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Associations Between Short-term Changes in Air Pollution and Correlates of Arterial Stiffness: The Veterans Affairs Normative Aging Study, 2007-2011.
Am. J. Epidemiol.
PUBLISHED: 11-13-2013
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We investigated associations between short-term exposure to air pollution and central augmentation index and augmentation pressure, correlates of arterial stiffness, in a cohort of elderly men in the Boston, Massachusetts, metropolitan area. This longitudinal analysis included 370 participants from the Veterans Affairs Normative Aging Study with up to 2 visits between 2007 and 2011 (n = 445). Augmentation index (as %) and augmentation pressure (in mmHg) were measured at each visit by using radial artery applanation tonometry for pulse wave analysis and modeled in a mixed effects regression model as continuous functions of moving averages of air pollution exposures (over 4 hours and 1, 3, 7, and 14 days). The results suggest that short-term changes in air pollution were associated with augmentation index and augmentation pressure at several moving averages. Interquartile range (IQR) increases in 3-day average exposure to particles with aerodynamic diameter less than 2.5 ?m (3.6-?g/m(3) IQR increase) and sulfate (1.4-?g/m(3) IQR increase) and 1-day average exposure to particle number counts (8,741-counts/cm(3) IQR increase) were associated with augmentation index values that were 0.8% (95% confidence interval (CI): 0.2, 1.4), 0.6% (95% CI: 0.1, 1.2), and 1.7% (95% CI: 0.4, 2.9) higher, respectively. Overall, the findings were similar for augmentation pressure. The findings support the hypothesis that exposure to air pollution may affect vascular function.
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Serum bilirubin is associated with lung function in a Swiss general population sample.
Eur. Respir. J.
PUBLISHED: 10-31-2013
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Bilirubin is a strong antioxidant. Increased serum levels were associated with respiratory disease and mortality risk. We studied the association of bilirubin with lung function in the SAPALDIA cohort.Associations between natural logarithmized bilirubin and forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC, and mean forced expiratory flow between 25%-75% of FVC (FEF25-75) were tested using multiple linear regression in the whole study population (n=4195) and strata of ever smoking and high body mass index (BMI, defined by the highest distribution quartile). Associations were retested with single nucleotide polymorphism rs6742078, a genetic determinant of bilirubin.High bilirubin levels were significantly associated with higher FEV1/FVC and FEF25-75 overall. Upon stratification, significant associations persisted in ever smokers, amounting to 1.1 percent (95%-confidence interval 0.1 to 2.2) increase in FEV1/FVC, and 116.2 mL·sec(-1) (-15.9 to 248.4) in FEF25-75 per interquartile range of bilirubin exposure in smokers with high BMI. Associations were positive but non -significant in never smokers with high BMI. Similarly, rs6742078 genotype TT was associated with increased FEV1/FVC and FEF25-75.Our results suggest a possible protective role of bilirubin on lung tissue, which could be important for prevention and therapy.
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Associations between arrhythmia episodes and temporally and spatially resolved black carbon and particulate matter in elderly patients.
Occup Environ Med
PUBLISHED: 10-18-2013
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Ambient air pollution has been associated with sudden deaths, some of which are likely due to ventricular arrhythmias. Defibrillator discharge studies have examined the association of air pollution with arrhythmias in sensitive populations. No studies have assessed this association using residence-specific estimates of air pollution exposure.
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Blood pressure and cognition: factors that may account for their inconsistent association.
Epidemiology
PUBLISHED: 09-14-2013
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Studies of hypertension and cognition variously report adverse, null, and protective associations. We evaluated evidence supporting three potential explanations for this variation: an effect of hypertension duration, an effect of age at hypertension initiation, and selection bias due to dependent censoring.
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Endotoxin in concentrated coarse and fine ambient particles induces acute systemic inflammation in controlled human exposures.
Occup Environ Med
PUBLISHED: 08-16-2013
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Knowledge of the inhalable particulate matter components responsible for health effects is important for developing targeted regulation.
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Altered methylation in tandem repeat element and elemental component levels in inhalable air particles.
Environ. Mol. Mutagen.
PUBLISHED: 08-06-2013
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Exposure to particulate matter (PM) has been associated with lung cancer risk in epidemiology investigations. Elemental components of PM have been suggested to have critical roles in PM toxicity, but the molecular mechanisms underlying their association with cancer risks remain poorly understood. DNA methylation has emerged as a promising biomarker for environmental-related diseases, including lung cancer. In this study, we evaluated the effects of PM elemental components on methylation of three tandem repeats in a highly exposed population in Beijing, China. The Beijing Truck Driver Air Pollution Study was conducted shortly before the 2008 Beijing Olympic Games (June 15-July 27, 2008) and included 60 truck drivers and 60 office workers. On two days separated by 1-2 weeks, we measured blood DNA methylation of SAT?, NBL2, D4Z4, and personal exposure to eight elemental components in PM2.5 , including aluminum (Al), silicon (Si), sulfur (S), potassium (K), calcium (Ca) titanium (Ti), iron (Fe), and zinc (Zn). We estimated the associations of individual elemental component with each tandem-repeat methylation in generalized estimating equations (GEE) models adjusted for PM2.5 mass and other covariates. Out of the eight examined elements, NBL2 methylation was positively associated with concentrations of Si [0.121, 95% confidence interval (CI): 0.030; 0.212, False Discovery Rate (FDR)?=?0.047] and Ca (0.065, 95%CI: 0.014; 0.115, FDR?=?0.047) in truck drivers. In office workers, SAT? methylation was positively associated with concentrations of S (0.115, 95% CI: 0.034; 0.196, FDR?=?0.042). PM-associated differences in blood tandem-repeat methylation may help detect biological effects of the exposure and identify individuals who may eventually experience higher lung cancer risk. Environ. Mol. Mutagen., 2013. © 2013 Wiley Periodicals, Inc.
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Improved air quality and attenuated lung function decline: modification by obesity in the SAPALDIA cohort.
Environ. Health Perspect.
PUBLISHED: 06-27-2013
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Air pollution and obesity are hypothesized to contribute to accelerated decline in lung function with age through their inflammatory properties.
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Long-term exposure to black carbon and carotid intima-media thickness: the normative aging study.
Environ. Health Perspect.
PUBLISHED: 06-27-2013
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Evidence suggests that air pollution is associated with atherosclerosis and that traffic-related particles are a particularly important contributor to the association.
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Modifying roles of glutathione S-transferase polymorphisms on the association between cumulative lead exposure and cognitive function.
Neurotoxicology
PUBLISHED: 06-04-2013
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Glutathione-S-transferase gene (GST) polymorphisms can result in variable ability of these enzymes to remove electrophilic substrates. We investigated whether the GSTP1 Val105 and GSTM1 deletion polymorphisms modify the lead-cognitive function association.
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Automatic determination of an anatomical coordinate system for a three-dimensional model of the human patella.
J Biomech
PUBLISHED: 05-28-2013
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Measuring the in vivo 3-D kinematics of the patella requires a repeatable anatomical coordinate system (ACS). The purpose of this study was to develop an algorithm to determine an ACS using the patellas unique morphology. An ACS was automatically constructed that aligned the proximal/distal (PD) axis with the posterior vertical ridge. Inter-subject ACS repeatability was determined by registering all patellae and their associated ACSs to a reference patella. The mean angle between the reference patella ACS and each subjects axes was less than 2.5° and the 95% CI was 1.0°-4.0°. Here, we presented an anatomical coordinate system that is independent of the observers subjective judgement or orientation of the knee within the scanner.
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Acute exposure to air pollution triggers atrial fibrillation.
J. Am. Coll. Cardiol.
PUBLISHED: 05-22-2013
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This study sought to evaluate the association of air pollution with the onset of atrial fibrillation (AF).
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Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators.
J Expo Sci Environ Epidemiol
PUBLISHED: 04-29-2013
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Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR)=1.16, 95% confidence interval (CI) 1.05-1.27 for a 1?°C decrease in the 24-h average) and lower absolute humidity (OR=1.06, 95% CI 1.03-1.08 for a 0.5?g/m(3) decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients.Journal of Exposure Science and Environmental Epidemiology advance online publication, 30 October 2013; doi:10.1038/jes.2013.72.
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Effects of prenatal community violence and ambient air pollution on childhood wheeze in an urban population.
J. Allergy Clin. Immunol.
PUBLISHED: 04-12-2013
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Prenatal exposures to stress and physical toxins influence childrens respiratory health, although few studies consider these factors together.
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Inhalable particulate matter and mitochondrial DNA copy number in highly exposed individuals in Beijing, China: a repeated-measure study.
Part Fibre Toxicol
PUBLISHED: 04-12-2013
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Mitochondria are both a sensitive target and a primary source of oxidative stress, a key pathway of air particulate matter (PM)-associated diseases. Mitochondrial DNA copy number (MtDNAcn) is a marker of mitochondrial damage and malfunctioning. We evaluated whether ambient PM exposure affects MtDNAcn in a highly-exposed population in Beijing, China.
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Exposure to airborne particulate matter is associated with methylation pattern in the asthma pathway.
Epigenomics
PUBLISHED: 04-10-2013
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Asthma exacerbation and other respiratory symptoms are associated with exposure to air pollution. Since environment affects gene methylation, it is hypothesized that asthmatic responses to pollution are mediated through methylation.
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Association between blood pressure and DNA methylation of retrotransposons and pro-inflammatory genes.
Int J Epidemiol
PUBLISHED: 03-20-2013
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Methylation of deoxyribonucleic acid (DNA) is an epigenetic regulator of gene expression that changes with age, but its contribution to aging-related disorders, including high blood pressure (BP), is still largely unknown. We examined the relation of BP to the methylation of retrotransposon sequences of DNA and of selected candidate genes.
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Temperature, myocardial infarction, and mortality: effect modification by individual- and area-level characteristics.
Epidemiology
PUBLISHED: 03-07-2013
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Although several studies have examined associations between temperature and cardiovascular-disease-related mortality, fewer have investigated the association between temperature and the development of acute myocardial infarction (MI). Moreover, little is known about who is most susceptible to the effects of temperature.
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Effect modification by transferrin C2 polymorphism on lead exposure, hemoglobin levels, and IQ.
Neurotoxicology
PUBLISHED: 03-04-2013
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Iron deficiency and lead exposure remain significant public health issues in many parts of the world and are both independently associated with neurocognitive deficits. Polymorphisms in iron transport pathways have been shown to modify the absorption and toxicity of lead.
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Longitudinal relationship between personal CO and personal PM2.5 among women cooking with woodfired cookstoves in Guatemala.
PLoS ONE
PUBLISHED: 02-26-2013
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Household air pollution (HAP) due to solid fuel use is a major public health threat in low-income countries. Most health effects are thought to be related to exposure to the fine particulate matter (PM) component of HAP, but it is currently impractical to measure personal exposure to PM in large studies. Carbon monoxide (CO) has been shown in cross-sectional analyses to be a reliable surrogate for particles<2.5 µm in diameter (PM2.5) in kitchens where wood-burning cookfires are a dominant source, but it is unknown whether a similar PM2.5-CO relationship exists for personal exposures longitudinally. We repeatedly measured (216 measures, 116 women) 24-hour personal PM2.5 (median [IQR]?=?0.11 [0.05, 0.21] mg/m(3)) and CO (median [IQR]?=?1.18 [0.50, 2.37] mg/m(3)) among women cooking over open woodfires or chimney woodstoves in Guatemala. Pollution measures were natural-log transformed for analyses. In linear mixed effects models with random subject intercepts, we found that personal CO explained 78% of between-subject variance in personal PM2.5. We did not see a difference in slope by stove type. This work provides evidence that in settings where there is a dominant source of biomass combustion, repeated measures of personal CO can be used as a reliable surrogate for an individuals PM2.5 exposure. This finding has important implications for the feasibility of reliably estimating long-term (months to years) PM2.5 exposure in large-scale epidemiological and intervention studies of HAP.
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Little effect of gestation at 3,100 m on fetal fat accretion or the fetal circulation.
Am. J. Hum. Biol.
PUBLISHED: 02-20-2013
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While chronic hypoxia has been recognized as the principal causative factor for decreasing birth weight at high altitude, unknown is whether fetal fat accretion and vascular function are affected.
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Residential proximity to high-traffic roadways and poststroke mortality.
J Stroke Cerebrovasc Dis
PUBLISHED: 02-04-2013
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Living in areas with higher levels of ambient air pollution has been associated with a higher incidence of ischemic stroke and all-cause mortality but less is known about the relationship between traffic-related pollution and long-term survival after stroke.
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Associations between cadmium exposure and neurocognitive test scores in a cross-sectional study of US adults.
Environ Health
PUBLISHED: 01-29-2013
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Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III).
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Ozone exposure, vitamin C intake, and genetic susceptibility of asthmatic children in Mexico City: a cohort study.
Respir. Res.
PUBLISHED: 01-24-2013
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We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF(25-75)) in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695), and NQO1 (rs1800566).
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Modification by hemochromatosis gene polymorphisms of the association between traffic-related air pollution and cognition in older men: a cohort study.
Environ Health
PUBLISHED: 01-11-2013
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Previous studies found effect modification of associations between traffic-related air pollution and cardiovascular outcomes by polymorphisms in the hemochromatosis gene (HFE). As traffic-related air pollution may impact cognition through effects on cardiovascular health or through mechanisms which may also influence cardiovascular outcomes, we hypothesized that HFE polymorphisms would also modify a previously observed association between traffic-related air pollution exposure and cognition in older men.
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Static and dynamic error of a biplanar videoradiography system using marker-based and markerless tracking techniques.
J Biomech Eng
PUBLISHED: 12-31-2011
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The use of biplanar videoradiography technology has become increasingly popular for evaluating joint function in vivo. Two fundamentally different methods are currently employed to reconstruct 3D bone motions captured using this technology. Marker-based tracking requires at least three radio-opaque markers to be implanted in the bone of interest. Markerless tracking makes use of algorithms designed to match 3D bone shapes to biplanar videoradiography data. In order to reliably quantify in vivo bone motion, the systematic error of these tracking techniques should be evaluated. Herein, we present new markerless tracking software that makes use of modern GPU technology, describe a versatile method for quantifying the systematic error of a biplanar videoradiography motion capture system using independent gold standard instrumentation, and evaluate the systematic error of the W.M. Keck XROMM Facilitys biplanar videoradiography system using both marker-based and markerless tracking algorithms under static and dynamic motion conditions. A polycarbonate flag embedded with 12 radio-opaque markers was used to evaluate the systematic error of the marker-based tracking algorithm. Three human cadaveric bones (distal femur, distal radius, and distal ulna) were used to evaluate the systematic error of the markerless tracking algorithm. The systematic error was evaluated by comparing motions to independent gold standard instrumentation. Static motions were compared to high accuracy linear and rotary stages while dynamic motions were compared to a high accuracy angular displacement transducer. Marker-based tracking was shown to effectively track motion to within 0.1?mm and 0.1 deg under static and dynamic conditions. Furthermore, the presented results indicate that markerless tracking can be used to effectively track rapid bone motions to within 0.15 deg for the distal aspects of the femur, radius, and ulna. Both marker-based and markerless tracking techniques were in excellent agreement with the gold standard instrumentation for both static and dynamic testing protocols. Future research will employ these techniques to quantify in vivo joint motion for high-speed upper and lower extremity impacts such as jumping, landing, and hammering.
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Childhood and adult socioeconomic position, cumulative lead levels, and pessimism in later life: the VA Normative Aging Study.
Am. J. Epidemiol.
PUBLISHED: 11-09-2011
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Pessimism, a general tendency toward negative expectancies, is a risk factor for depression and also heart disease, stroke, and reduced cancer survival. There is evidence that individuals with higher lead exposure have poorer health. However, low socioeconomic status (SES) is linked with higher lead levels and greater pessimism, and it is unclear whether lead influences psychological functioning independently of other social factors. The authors considered interrelations among childhood and adult SES, lead levels, and psychological functioning in data collected on 412 Boston area men between 1991 and 2002 in a subgroup of the VA Normative Aging Study. Pessimism was measured by using the Life Orientation Test. Cumulative (tibia) lead was measured by x-ray fluorescence. Structural equation modeling was used to quantify the relations as mediated by childhood and adult SES, controlling for age, health behaviors, and health status. An interquartile range increase in lead quartile was associated with a 0.37 increase in pessimism score (P < 0.05). Low childhood and adult SES were related to higher tibia lead levels, and both were also independently associated with higher pessimism. Lead maintained an independent association with pessimism even after childhood and adult SES were considered. Results demonstrate an interrelated role of lead burden and SES over the life course in relation to psychological functioning in older age.
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Exploring potential sources of differential vulnerability and susceptibility in risk from environmental hazards to expand the scope of risk assessment.
Am J Public Health
PUBLISHED: 10-20-2011
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Genetic factors, other exposures, individual disease states and allostatic load, psychosocial stress, and socioeconomic position all have the potential to modify the response to environmental exposures. Moreover, many of these modifiers covary with the exposure, leading to much higher risks in some subgroups. These are not theoretical concerns; rather, all these patterns have already been demonstrated in studies of the effects of lead and air pollution. However, recent regulatory impact assessments for these exposures have generally not incorporated these findings. Therefore, differential risk and vulnerability is a critically important but neglected area within risk assessment, and should be incorporated in the future.
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Expanding the scope of environmental risk assessment to better include differential vulnerability and susceptibility.
Am J Public Health
PUBLISHED: 10-20-2011
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The central paradigm of the Environmental Protection Agency is risk assessment. We examined how differential responses across population groups could be better integrated into the environmental risk assessment process, providing tools to achieve greater equity in health status in addition to risk reduction. Such integration was difficult with paradigms like reference dose and was easier with consideration of dose-response curves, which incorporated nontrivial effects observed at low doses for common exposures. We identified 6 assumptions implicit in standard chemical risk assessments that should changed: (1) risk independence, (2) risk averaging, (3) risk nontransferability, (4) risk synchrony, (5) risk accumulation and chaining, and (6) quantification of numbers of persons above certain thresholds or limit values sufficient to characterize risk.
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Expanding the scope of risk assessment: methods of studying differential vulnerability and susceptibility.
Am J Public Health
PUBLISHED: 10-20-2011
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Several methodological issues have been identified in analysis of epidemiological data to better assess the distributional effects of exposures and hypotheses about effect modification. We discuss the hierarchical mixed model and some more complex methods. Methods of capturing inequality are a second dimension of risk assessment, and simulation studies are important because plausible choices for air pollution effects and effect modifiers could result in extremely high risks in a small subset of the population. Future epidemiological studies should explore contextual and individual-level factors that might modify these relationships. The Environmental Protection Agency should make this a standard part of their risk assessments whenever the necessary information is available.
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Optimism in relation to inflammation and endothelial dysfunction in older men: the VA Normative Aging Study.
Psychosom Med
PUBLISHED: 09-23-2011
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Recent research suggests that optimism may reduce the risk of incident cardiovascular disease, but the mechanisms have not been determined. This study examines the association of optimism with change in inflammation and endothelial function over time in men.
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Associations of early childhood manganese and lead coexposure with neurodevelopment.
Environ. Health Perspect.
PUBLISHED: 09-01-2011
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Most toxicologic studies focus on a single agent, although this does not reflect real-world scenarios in which humans are exposed to multiple chemicals.
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Associations of toenail arsenic, cadmium, mercury, manganese, and lead with blood pressure in the normative aging study.
Environ. Health Perspect.
PUBLISHED: 08-30-2011
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Arsenic, cadmium, mercury, and lead are associated with cardiovascular disease in epidemiologic research. These associations may be mediated by direct effects of the metals on blood pressure (BP) elevation. Manganese is associated with cardiovascular dysfunction and hypotension in occupational cohorts.
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Effects of particulate air pollution on blood pressure in a highly exposed population in Beijing, China: a repeated-measure study.
Environ Health
PUBLISHED: 08-19-2011
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Particulate Matter (PM) exposure is critical in Beijing due to high population density and rapid increase in vehicular traffic. PM effects on blood pressure (BP) have been investigated as a mechanism mediating cardiovascular risks, but results are still inconsistent. The purpose of our study is to determine the effects of ambient and personal PM exposure on BP.
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Particulate air pollution and socioeconomic position in rural and urban areas of the Northeastern United States.
Am J Public Health
PUBLISHED: 08-11-2011
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Although differential exposure by socioeconomic position (SEP) to hazardous waste and lead is well demonstrated, there is less evidence for particulate air pollution (PM), which is associated with risk of death and illness. This study determined the relationship of ambient PM and SEP across several spatial scales.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.