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1.  Contaminated Turmeric Is a Potential Source of Lead Exposure for Children in Rural Bangladesh 
Background. During the conduct of a cohort study intended to study the associations between mixed metal exposures and child health outcomes, we found that 78% of 309 children aged 20–40 months evaluated in the Munshiganj District of Bangladesh had blood lead concentrations ≥5 µg/dL and 27% had concentrations ≥10 µg/dL. Hypothesis. Environmental sources such as spices (e.g., turmeric, which has already faced recalls in Bangladesh due to high lead levels) may be a potential route of lead exposure. Methods. We conducted visits to the homes of 28 children randomly selected from among high and low blood lead concentration groups. During the visits, we administered a structured questionnaire and obtained soil, dust, rice, and spice samples. We obtained water samples from community water sources, as well as environmental samples from neighborhood businesses. Results. Lead concentrations in many turmeric samples were elevated, with lead concentrations as high as 483 ppm. Analyses showed high bioaccessibility of lead. Conclusions. Contamination of turmeric powder is a potentially important source of lead exposure in this population.
PMCID: PMC4158309  PMID: 25214856
2.  Functional Characterization of Polymorphisms in the Peptidase Inhibitor 3 (Elafin) Gene and Validation of Their Contribution to Risk of Acute Respiratory Distress Syndrome 
Elafin (peptidase inhibitor 3 [PI3]) and its biologically active precursor, pre-elafin, are neutrophil serine proteinase inhibitors with an important role in preventing excessive tissue injury during inflammatory events. Recently, we reported an association between single-nucleotide polymorphism (SNP) rs2664581 in the PI3 gene, increased risk of acute respiratory distress syndrome (ARDS) and pre-elafin circulating levels. This study aims to validate the legitimacy of this association by using a cohort of patients who met the criteria for systemic inflammatory response syndrome and were at risk of developing ARDS (n = 840). A comprehensive functional study of SNPs in PI3 gene was also performed. Luciferase assays and electrophoretic mobility shift assays were conducted to determine the functional relevance of promoter region variants. The effect of the coding SNP rs2664581 on the neutrophil elastase inhibitory activity and transglutaminase binding properties of pre-elafin was also investigated. The variant allele of rs2664581 (C) was significantly associated with increased ARDS risk, mainly among subjects with sepsis (odds ratio = 1.44; 95% confidence interval = 1.04–1.99; P = 0.0276, adjusted by age, sex, and Acute Physiology and Chronic Health Evaluation III). Pre-elafin recombinant protein carrying the amino acid change associated with rs2664581 (Thr34Pro, mutant protein [MT]) had greater capacity to undergo transglutaminase-mediated cross-linking to immobilized fibronectin than wild-type protein in vitro (P < 0.003). No differences were observed in the neutrophil elastase inhibitory activities of wild-type versus MT proteins. In addition, the risk allele–promoter construct had significantly lower cytokine-induced transcriptional activity. Electrophoretic mobility shift assay results indicated a differential binding of nuclear proteins to the G and A alleles of SNP −338G > A. Our results confirm the association between SNP rs2664581 and enhanced risk of ARDS, further supporting the role of PI3 in ARDS development. SNPs in the PI3 locus may act synergistically by regulating PI3 gene expression and pre-elafin biological functions.
PMCID: PMC4148037  PMID: 24617927
acute respiratory distress syndrome; elafin; single-nucleotide polymorphism; genetic association; replication
3.  Occupational Exposures and Longitudinal Lung Function Decline 
Few longitudinal studies have been conducted on occupational exposure and lung function. This study investigated occupational dust exposure effects on lung function and whether genetic variants influence such effects.
The study population (1,332 participants) was from the Framingham Heart Study, in which participant lung function measures were available from up to five examinations over nearly 17 years. Occupational dust exposures were classified into “more” and “less” likely dust exposure. We used linear mixed effects models for the analysis.
Participants with more likely dust exposure had a mean 4.5 mL/year excess loss rate of FEV1 over time. However, occupational dust exposures alone or interactions with age or time had no significant effect on FEV1/FVC. No statistically significant effects of genetic modifications in the different subgroups were identified for FEV1 loss.
Occupational dust exposures may accelerate the rate of FEV1 loss but not FEV1/FVC loss.
PMCID: PMC4512740  PMID: 25384732
job exposure matrix; forced expiratory volume in one second; chronic obstructive pulmonary disease; environmental lung disease; environmental health; occupational health; occupational respiratory disease
4.  Prognostic Significance of MTOR Pathway Component Expression in Neuroendocrine Tumors 
Journal of Clinical Oncology  2013;31(27):3418-3425.
Clinical studies have implicated the mechanistic target of rapamycin (serine/threonine kinase; MTOR) pathway in the regulation of neuroendocrine tumor (NET) growth. We explored whether expression of MTOR pathway components has prognostic significance in NET patients.
Patients and Methods
We evaluated immunohistochemical expression of MTOR and phospho (p) –MTOR; its downstream targets RPS6KB1, RPS6, and EIF4EBP1; and its upstream regulators, in a cohort of 195 archival neuroendocrine tumors. We correlated expression levels with clinical outcomes, after adjusting for other prognostic variables.
We observed anticipated correlations between expression of upstream components of the MTOR pathway and their downstream targets. Expression of PIK3CA, MTOR, or p-EIF4EBP1 was associated with high MKI67 (Ki-67) labeling index. We failed to identify clinical correlations associated with expression of the upstream regulators TSC1, TSC2, AKT, p-AKT, PDPK1, PTEN, PIK3R1, or PIK3CA. In contrast, high expression of MTOR or its activated downstream targets p-RPS6KB1, p-RPS6, or p-EIF4EBP1 was associated with adverse clinical outcomes.
Our observations suggest that expression of MTOR or its downstream targets may be adverse prognostic factors in neuroendocrine tumors.
PMCID: PMC3770868  PMID: 23980085
5.  Invasive Adenocarcinoma of the Lung is Associated with the Upper Lung Regions 
We postulated that ventilation-perfusion (V/Q) relationships within the lung might influence where lung cancer occurs. To address this hypothesis we evaluated the location of lung adenocarcinoma, by both tumor lobe and superior-inferior regional distribution, and associated variables such as emphysema.
Materials and Methods
One hundred fifty-nine cases of invasive adenocarcinoma and adenocarcinoma with lepidic features were visually evaluated to identify lobar or regional tumor location. Regions were determined by automated division of the lungs into three equal volumes: (upper region, middle region, or lower region). Automated densitometry was used to measure radiographic emphysema.
The majority of invasive adenocarcinomas occurred in the upper lobes (69%), with 94% of upper lobe adenocarcinomas occurring in the upper region of the lung. The distribution of adenocarcinoma, when classified as upper or lower lobe, was not different between invasive adenocarcinoma and adenocarcinoma with lepidic features (formerly bronchioloalveolar cell carcinoma, P=0.08). Regional distribution of tumor was significantly different between invasive adenocarcinoma and adenocarcinoma with lepidic features (P = 0.001). Logistic regression analysis with the outcome of invasive adenocarcinoma histology was used to adjust for confounders. Tumor region continued to be a significant predictor (OR 8.5, P=0.008, compared to lower region), whereas lobar location of tumor was not (P=0.09). In stratified analysis, smoking was not associated with region of invasive adenocarcinoma occurrence (p=0.089). There was no difference in total emphysema scores between invasive adenocarcinoma cases occurring in each of the three regions (P=0.155). There was also no difference in the distribution of region of adenocarcinoma occurrence between quartiles of emphysema (P=0.217).
Invasive adenocarcinoma of the lung is highly associated with the upper lung regions. This association is not related to smoking, history of COPD, or total emphysema. The regional distribution of invasive adenocarcinoma may be due to V/Q relationships or other local factors.
PMCID: PMC4004700  PMID: 24598367
Non-small cell lung cancer; tumor location; emphysema
6.  Smoking and smoking cessation in relation to the development of co-existing non-small cell lung cancerwith chronic obstructive pulmonary disease 
PMCID: PMC4008140  PMID: 23921845
Cigarette smoking; Smoking cessation; non-small cell lung cancer; coexisting chronic obstructive pulmonary disease; risk
7.  Toenail metal concentration as a biomarker of occupational welding fume exposure 
In populations exposed to heavy metals, there are few biomarkers that capture intermediate exposure windows. We sought to determine the correlation between toenail metal concentrations and prior 12 month work activity in welders with variable, metal-rich, welding fume exposures. Forty-eight participants, recruited through a local union, provided 69 sets of toenail clippings. Union-supplied and worker verified personal work histories were used to quantify hours welded and respirator use. Toenail samples were digested and analyzed for lead (Pb), manganese (Mn), cadmium (Cd), nickel (Ni) and arsenic (As) using ICP-MS. Spearman correlation coefficients were used to examine the correlation between toenail metal concentrations. Using mixed models to account for multiple participation times, we divided hours welded into three-month intervals and examined how weld hours correlated with log-transformed toenail Pb, Mn, Cd, Ni and As concentrations. Highest concentrations were found for Ni, followed by Mn, Pb and As, and Cd. All of the metals were significantly correlated with one another (rho range=0.28–0.51), with the exception of Ni and As (rho=0.20, p=0.17). Using mixed models adjusted for age, respirator use, smoking status and BMI, we found that Mn was associated with weld hours 7–9 months prior to clipping (p = 0.003), Pb was associated with weld hours 10–12 months prior to clipping (p=0.03) and over the entire year (p=0.04). Cd was associated with weld hours 10–12 months prior to clipping (p=0.05), and also with the previous year’s total hours welded (p=0.02). The association between Ni and weld hours 7–9 months prior to clipping approached significance (p=0.06). Toenail metal concentrations were not associated with the long-term exposure metric, years as a welder. Results suggest Mn, Pb, and Cd may have particular windows of relevant exposure that reflect work activity. In a population with variable exposure, toenails may serve as useful biomarkers for occupational metal fume exposures to Mn, Pb and Cd during distinct periods over the year prior to sample collection.
PMCID: PMC4019688  PMID: 24372360
Toenail; welding fume; lead; manganese; cadmium; biomarker
8.  Inverse association between toenail arsenic and body mass index in a population of welders 
Environmental research  2014;131:131-133.
Recent data show that arsenic may play a role in obesity-related diseases. However, urinary arsenic studies report an inverse association between arsenic level and body mass index (BMI). We explored whether toenail arsenic, a long-term exposure measure, was associated with BMI in 74 welders with known arsenic exposure. BMI showed significant inverse associations with toenail arsenic (p=0.01), which persisted in models adjusted for demographics, diet and work history. It is unclear whether low arsenic biomarker concentrations in high BMI subjects truly reflect lower exposures, or instead reflect internal or metabolic changes that alter arsenic metabolism and tissue deposition.
PMCID: PMC4035809  PMID: 24721130
Arsenic; toenail; BMI; welding fume; environmental health; metals; occupational health
9.  Association of Low to Moderate Levels of Arsenic Exposure With Risk of Type 2 Diabetes in Bangladesh 
American Journal of Epidemiology  2013;178(10):1563-1570.
Chronic exposure to high levels of arsenic in drinking water is associated with increased risk of type 2 diabetes mellitus (T2DM), but the association between lower levels of arsenic and T2DM is more controversial. Therefore, this study evaluated the association between low to moderate arsenic exposure and T2DM. In 2009–2011, we conducted a study of 957 Bangladeshi adults who participated in a case-control study of skin lesions in 2001–2003. The odds ratio of T2DM was evaluated in relationship to arsenic exposure measured in drinking water and in subjects’ toenails (in 2001–2003) prior to the diagnosis of T2DM (in 2009–2011). Compared with those exposed to the lowest quartile of arsenic in water (≤1.7 µg/L), the adjusted odds ratio for T2DM was 1.92 (95% confidence interval (CI): 0.82, 4.35) for those in the second quartile, 3.07 (95% CI: 1.38, 6.85) for those in the third quartile, and 4.51 (95% CI: 2.01, 10.09) for those in the fourth quartile. The relative excess risk of T2DM was 4.78 for individuals who smoked and 8.93 for people who had a body mass index (weight (kg)/height (m)2) greater than 25. These findings suggest that exposure to modest levels of arsenic in drinking water was associated with increased risk of T2DM in Bangladesh. Being overweight or smoking was also associated with increased risk of T2DM.
PMCID: PMC3888275  PMID: 24049161
additive interaction; arsenic; Bangladesh; diabetes; overweight; smoking
10.  Circulating alanine transaminase (ALT) and γ-glutamyl transferase (GGT), but not fetuin-A, is associated with metabolic risk factors, at baseline and at two-year follow-up: the prospective Cyprus Metabolism Study 
To comparatively evaluate traditional liver tests and fetuin A as predictors of cardiometabolic risk, we studied associations between serum alanine transaminase (ALT), γ-glutamyl transferase (GGT), aspartate aminotransferase (AST) and fetuin-A and anthropometric, metabolic, and cardiovascular parameters cross-sectionally at baseline, and prospectively, after 2-years of follow-up.
Research Design and Methods
616 randomly enrolled young healthy participants in the Cyprus Metabolism Study, including all 93 subjects who participated in the follow-up study 2 years after baseline assessment, were included in this study.
In the cross-sectional study, serum ALT and GGT were strongly correlated with anthropometric, cardiovascular, and metabolic variables, while serum AST was only correlated with waist circumference and waist-to-hip ratio. Fetuin-A was correlated with anthropometric variables, systolic blood pressure (SBP), insulin, and homeostasis model of assessment-insulin resistance (HOMA-IR) in the unadjusted model. In the fully adjusted model, both serum ALT and GGT levels remained positively correlated with total and low-density lipoprotein (LDL) cholesterol. GGT levels also remained correlated with triglycerides. ALT levels remained strongly positively correlated with insulin (r=0.17, p<.0001) and HOMA-IR (r=0.16, p=0.0001). Serum fetuin-A levels were no longer significantly correlated with any variables. Prospectively, ALT and GGT were predictors of anthropometric variables and LDL cholesterol, while baseline levels of AST and fetuin-A were not predictors of any variables at 2-year follow-up.
We confirmed associations of ALT and GGT levels but failed to demonstrate an independent association between fetuin-A and cardiometabolic risk factors in young healthy men. Traditional liver tests (LFTs) are thus better than fetuin-A predictors of metabolic risk factors cross-sectionally and prospectively in young healthy adults.
PMCID: PMC4104665  PMID: 24726813
obesity; insulin resistance; metabolic syndrome
11.  IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans 
Pearce, Neil | Blair, Aaron | Vineis, Paolo | Ahrens, Wolfgang | Andersen, Aage | Anto, Josep M. | Armstrong, Bruce K. | Baccarelli, Andrea A. | Beland, Frederick A. | Berrington, Amy | Bertazzi, Pier Alberto | Birnbaum, Linda S. | Brownson, Ross C. | Bucher, John R. | Cantor, Kenneth P. | Cardis, Elisabeth | Cherrie, John W. | Christiani, David C. | Cocco, Pierluigi | Coggon, David | Comba, Pietro | Demers, Paul A. | Dement, John M. | Douwes, Jeroen | Eisen, Ellen A. | Engel, Lawrence S. | Fenske, Richard A. | Fleming, Lora E. | Fletcher, Tony | Fontham, Elizabeth | Forastiere, Francesco | Frentzel-Beyme, Rainer | Fritschi, Lin | Gerin, Michel | Goldberg, Marcel | Grandjean, Philippe | Grimsrud, Tom K. | Gustavsson, Per | Haines, Andy | Hartge, Patricia | Hansen, Johnni | Hauptmann, Michael | Heederik, Dick | Hemminki, Kari | Hemon, Denis | Hertz-Picciotto, Irva | Hoppin, Jane A. | Huff, James | Jarvholm, Bengt | Kang, Daehee | Karagas, Margaret R. | Kjaerheim, Kristina | Kjuus, Helge | Kogevinas, Manolis | Kriebel, David | Kristensen, Petter | Kromhout, Hans | Laden, Francine | Lebailly, Pierre | LeMasters, Grace | Lubin, Jay H. | Lynch, Charles F. | Lynge, Elsebeth | ‘t Mannetje, Andrea | McMichael, Anthony J. | McLaughlin, John R. | Marrett, Loraine | Martuzzi, Marco | Merchant, James A. | Merler, Enzo | Merletti, Franco | Miller, Anthony | Mirer, Franklin E. | Monson, Richard | Nordby, Karl-Cristian | Olshan, Andrew F. | Parent, Marie-Elise | Perera, Frederica P. | Perry, Melissa J. | Pesatori, Angela Cecilia | Pirastu, Roberta | Porta, Miquel | Pukkala, Eero | Rice, Carol | Richardson, David B. | Ritter, Leonard | Ritz, Beate | Ronckers, Cecile M. | Rushton, Lesley | Rusiecki, Jennifer A. | Rusyn, Ivan | Samet, Jonathan M. | Sandler, Dale P. | de Sanjose, Silvia | Schernhammer, Eva | Costantini, Adele Seniori | Seixas, Noah | Shy, Carl | Siemiatycki, Jack | Silverman, Debra T. | Simonato, Lorenzo | Smith, Allan H. | Smith, Martyn T. | Spinelli, John J. | Spitz, Margaret R. | Stallones, Lorann | Stayner, Leslie T. | Steenland, Kyle | Stenzel, Mark | Stewart, Bernard W. | Stewart, Patricia A. | Symanski, Elaine | Terracini, Benedetto | Tolbert, Paige E. | Vainio, Harri | Vena, John | Vermeulen, Roel | Victora, Cesar G. | Ward, Elizabeth M. | Weinberg, Clarice R. | Weisenburger, Dennis | Wesseling, Catharina | Weiderpass, Elisabete | Zahm, Shelia Hoar
Environmental Health Perspectives  2015;123(6):507-514.
Background: Recently, the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also for the approach used to perform these evaluations. Some critics have claimed that failures of IARC Working Groups to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans.
Objectives: The authors of this Commentary are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We examined criticisms of the IARC classification process to determine the validity of these concerns. Here, we present the results of that examination, review the history of IARC evaluations, and describe how the IARC evaluations are performed.
Discussion: We concluded that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various disciplines and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed.
Conclusions: The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public’s health.
Citation: Pearce N, Blair A, Vineis P, Ahrens W, Andersen A, Anto JM, Armstrong BK, Baccarelli AA, Beland FA, Berrington A, Bertazzi PA, Birnbaum LS, Brownson RC, Bucher JR, Cantor KP, Cardis E, Cherrie JW, Christiani DC, Cocco P, Coggon D, Comba P, Demers PA, Dement JM, Douwes J, Eisen EA, Engel LS, Fenske RA, Fleming LE, Fletcher T, Fontham E, Forastiere F, Frentzel-Beyme R, Fritschi L, Gerin M, Goldberg M, Grandjean P, Grimsrud TK, Gustavsson P, Haines A, Hartge P, Hansen J, Hauptmann M, Heederik D, Hemminki K, Hemon D, Hertz-Picciotto I, Hoppin JA, Huff J, Jarvholm B, Kang D, Karagas MR, Kjaerheim K, Kjuus H, Kogevinas M, Kriebel D, Kristensen P, Kromhout H, Laden F, Lebailly P, LeMasters G, Lubin JH, Lynch CF, Lynge E, ‘t Mannetje A, McMichael AJ, McLaughlin JR, Marrett L, Martuzzi M, Merchant JA, Merler E, Merletti F, Miller A, Mirer FE, Monson R, Nordby KC, Olshan AF, Parent ME, Perera FP, Perry MJ, Pesatori AC, Pirastu R, Porta M, Pukkala E, Rice C, Richardson DB, Ritter L, Ritz B, Ronckers CM, Rushton L, Rusiecki JA, Rusyn I, Samet JM, Sandler DP, de Sanjose S, Schernhammer E, Seniori Costantini A, Seixas N, Shy C, Siemiatycki J, Silverman DT, Simonato L, Smith AH, Smith MT, Spinelli JJ, Spitz MR, Stallones L, Stayner LT, Steenland K, Stenzel M, Stewart BW, Stewart PA, Symanski E, Terracini B, Tolbert PE, Vainio H, Vena J, Vermeulen R, Victora CG, Ward EM, Weinberg CR, Weisenburger D, Wesseling C, Weiderpass E, Zahm SH. 2015. IARC Monographs: 40 years of evaluating carcinogenic hazards to humans. Environ Health Perspect 123:507–514;
PMCID: PMC4455595  PMID: 25712798
12.  Epigenome-wide DNA methylation changes with development of arsenic-induced skin lesions in Bangladesh: a case-control follow-up study 
Studies have found an association between aberrant DNA methylation and arsenic-induced skin lesions. Yet, little is known about DNA methylation changes over time in people who develop arsenic-induced skin lesions. We sought to investigate epigenome-wide changes of DNA methylation in people who developed arsenic-induced skin lesions in a ten year period. In 2009–2011, we conducted a follow-up study of 900 skin lesion cases and 900 controls and identified 10 people who developed skin lesions since a baseline survey in 2001–2003. The 10 cases (“New Cases”) were matched with 10 controls who did not have skin lesions at baseline or follow-up (“Persistent Controls”). Drinking water and blood samples were collected and skin lesion was diagnosed by the same physician at both time points. We measured DNA methylation in blood using Infinium HumanMethylation450K BeadChip, followed by quantitative validation using pyrosequencing. Two-sample t-tests were used to compare changes in percent methylation between New Cases and Persistent Controls. Six CpG sites with greatest changes of DNA methylation over time among New Cases were further validated with a correlation of 93% using pyrosequencing. One of the validated CpG site (cg03333116; change of %methylation was 13.2 in New Cases versus −0.09 in Persistent Controls; P <0.001) belonged to the RHBDF1 gene, which was previously reported to be hypermethylated in arsenic-exposed cases. We examined DNA methylation changes with the development of arsenic-induced skin lesions over time but nothing was statistically significant given the small sample size of this exploratory study and the high dimensionality of data.
PMCID: PMC4082746  PMID: 24677489
Arsenic; DNA methylation; Illumina 450K; longitudinal; skin lesion
13.  Effect of prenatal arsenic exposure on DNA methylation and leukocyte subpopulations in cord blood 
Epigenetics  2014;9(5):774-782.
Prenatal arsenic exposure is associated with increased risk of disease in adulthood. This has led to considerable interest in arsenic’s ability to disrupt fetal programming. Many studies report that arsenic exposure alters DNA methylation in whole blood but these studies did not adjust for cell mixture. In this study, we examined the relationship between arsenic in maternal drinking water collected ≤ 16 weeks gestational age and DNA methylation in cord blood (n = 44) adjusting for leukocyte-tagged differentially methylated regions. DNA methylation was quantified using the Infinium HumanMethylation 450 BeadChip array. Recursively partitioned mixture modeling examined the relationship between arsenic and methylation at 473,844 CpG sites. Median arsenic concentration in water was 12 µg/L (range < 1- 510 µg/L). Log10 arsenic was associated with altered DNA methylation across the epigenome (P = 0.002); however, adjusting for leukocyte distributions attenuated this association (P = 0.013). We also observed that arsenic had a strong effect on the distribution of leukocytes in cord blood. In adjusted models, every log10 increase in maternal drinking water arsenic exposure was estimated to increase CD8+ T cells by 7.4% (P = 0.0004) and decrease in CD4+ T cells by 9.2% (P = 0.0002). These results show that prenatal exposure to arsenic had an exposure-dependent effect on specific T cell subpopulations in cord blood and altered DNA methylation in cord blood. Future research is needed to determine if these small changes in DNA methylation alter gene expression or are associated with adverse health effects.
PMCID: PMC4063836  PMID: 24525453
arsenic; DNA methylation; cord blood; immune function; leukocytes; developmental programming
14.  Hemopexin in severe inflammation and infection: mouse models and human diseases 
Critical Care  2015;19(1):166.
Cell-free plasma hemoglobin is associated with poor outcome in patients with sepsis. Extracellular hemoglobin and secondarily released heme amplify inflammation in the presence of microbial TLR ligands and/or endogenous mediators. Hemopexin, a plasma protein that binds heme with extraordinary affinity, blocks these effects and has been proposed as a possible treatment approach to decrease inflammation in critically ill patients.
We studied mouse models of endotoxemia, burn wound infections and peritonitis in order to assess if a repletion strategy for hemopexin might be reasonable. We also measured hemopexin in small numbers of three patient populations that might be logical groups for hemopexin therapy: patients with sepsis and ARDS, patients with severe burns, and premature infants.
Despite severe disease, mean plasma hemopexin levels were increased above baseline in each murine model. However, plasma hemopexin levels were decreased or markedly decreased in many patients in each of the three patient populations.
Potentially different behavior of hemopexin in mice and humans may be important to consider when utilizing murine models to represent acute human inflammatory diseases in which heme plays a role. The findings raise the possibility that decreased hemopexin could result in insufficiently neutralized or cleared heme in some patients with ARDS, burns, or in premature infants who might be candidates to benefit from hemopexin administration.
Electronic supplementary material
The online version of this article (doi:10.1186/s13054-015-0885-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4424824  PMID: 25888135
15.  A community study of the effect of polycyclic aromatic hydrocarbon metabolites on heart rate variability using the Framingham score 
To investigate the effects of the urinary metabolite profiles of background exposure to the atmospheric pollutants polycyclic aromatic hydrocarbons (PAHs), and Framingham risk score (FRS), which assesses an individual’s cardiovascular disease risk, on heart rate variability (HRV).
The study, conducted from April to May 2011 in Wuhan, China, included 1,978 adult residents with completed questionnaires, physical examinations, blood and urine samples, and 5-min HRV indices [including standard deviation of NN intervals (SDNN), root mean square successive difference (rMSSD), low frequency (LF), high frequency (HF) and their ratio (LF/HF), and total power (TP)] obtained from 3-channel Holter monitor. 12 urinary PAH metabolites were measured by gas chromatography–mass spectrometry. FRS was calculated based on age, sex, lipid profiles, blood pressure, diabetes, and smoking status. Linear regression models were constructed after adjusting for potential confounders.
Elevated ΣOHNa was significantly associated, in a dose-responsive manner, with decreased SDNN and LF/HF (Ptrend = 0.014 and 0.007, respectively); elevated ΣOHFlu was significantly associated with reduced SDNN, LF, and LF/HF (Ptrend = 0.027, 0.003, and < 0.0001, respectively); and elevated ΣOH-PAHs was associated with decreased LF and LF/HF (Ptrend = 0.005 and < 0.0001, respectively). Moreover, increasing quartiles of FRS were significantly associated with decreased HRV indices, except LF/HF (Ptrend <0.001). Interestingly, individuals in low-risk subgroups had greater decreases in SDNN, LF, and LF/HF in relation to ΣOH-PAHs, ΣOHNa, and ΣOHFlu than those in high-risk subgroups (all P <0.05).
Environmental PAHs exposure may differentially affect HRV based on individual coronary risk profiles.
PMCID: PMC4393852  PMID: 24627303
Framingham risk score; heart rate variability; PAH
16.  Arsenic is associated with reduced effect of folic acid in myelomeningocele prevention: a case control study in Bangladesh 
Environmental Health  2015;14:34.
Arsenic induces neural tube defects in several animal models, but its potential to cause neural tube defects in humans is unknown. Our objective was to investigate the associations between maternal arsenic exposure, periconceptional folic acid supplementation, and risk of posterior neural tube defect (myelomeningocele) among a highly exposed population in rural Bangladesh.
We performed a case–control study that recruited physician-confirmed cases from community health clinics served by Dhaka Community Hospital in Bangladesh, as well as local health facilities that treat children with myelomeningocele. Controls were selected from pregnancy registries in the same areas. Maternal arsenic exposure was estimated from drinking water samples taken from wells used during the first trimester of pregnancy. Periconceptional folic acid use was ascertained by self-report, and maternal folate status was further assessed by plasma folate levels measured at the time of the study visit.
Fifty-seven cases of myelomeningocele were identified along with 55 controls. A significant interaction was observed between drinking water inorganic arsenic and periconceptional folic acid use. As drinking water inorganic arsenic concentrations increased from 1 to 25 μg/L, the estimated protective effect of folic acid use declined (OR 0.22 to 1.03), and was not protective at higher concentrations of arsenic. No main effect of arsenic exposure on myelomeningocele risk was identified.
Our study found a significant interaction between drinking water inorganic arsenic concentration from wells used during the first trimester of pregnancy and reported intake of periconceptional folic acid supplements. Results suggest that environmental arsenic exposure reduces the effectiveness of folic acid supplementation in preventing myelomeningocele.
PMCID: PMC4404044  PMID: 25885259
Arsenic; Neural tube defect; Myelomeningocele; Birth defect; Folate deficiency
17.  The Association Between Global DNA Methylation and Telomere Length in a Longitudinal Study of Boilermakers 
Genetic epidemiology  2014;38(3):254-264.
The objectives of this study were to determine if global DNA methylation, as reflected in LINE-1 and Alu elements, is associated with telomere length and whether it modifies the rate of telomeric change. A repeated-measures longitudinal study was performed with a panel of 87 boilermaker subjects. The follow-up period was 29 months. LINE-1 and Alu methylation was determined using pyrosequencing. Leukocyte relative telomere length was assessed via real-time qPCR. Linear-mixed models were used to estimate the association between DNA methylation and telomere length. A structural equation model (SEM) was used to explore the hypothesized relationship between DNA methylation, proxies of particulate matter exposure, and telomere length at baseline. There appeared to be a positive association between both LINE-1 and Alu methylation levels, and telomere length. For every incremental increase in LINE-1 methylation, there was a statistically significant 1.0 × 10−1 (95% CI: 4.6 × 10−2, 1.5 × 10−1, P < 0.01) unit increase in relative telomere length, controlling for age at baseline, current and past smoking status, work history, BMI (log kg/m2) and leukocyte differentials. Furthermore, for every incremental increase in Alu methylation, there was a statistically significant 6.2 × 10−2 (95% CI: 1.0 × 10−2, 1.1 × 10−1, P = 0.02) unit increase in relative telomere length. The interaction between LINE-1 methylation and follow-up time was statistically significant with an estimate −9.8 × 10−3 (95% CI: −1.8 × 10−2, −1.9 × 10−3, P = 0.02); suggesting that the rate of telomeric change was modified by the degree of LINE-1 methylation. No statistically significant association was found between the cumulative PM exposure construct, with global DNA methylation and telomere length at baseline.
PMCID: PMC4031748  PMID: 24616077
telomere; LINE-1; Alu; DNA methylation; longitudinal
18.  Single nucleotide polymorphisms in the matrix metalloproteinase gene family and the frequency and duration of gastroesophageal reflux disease influence the risk of esophageal adenocarcinoma 
The matrix metalloproteinase (MMP) family of proteins mediates various cellular pathways, including apoptosis and angiogenesis. Polymorphisms of MMP genes are associated with increased esophageal adenocarcinoma (EAC) risk. Gastroesophageal reflux disease (GERD) is an established EAC risk factor. We examined whether MMP polymorphism-EAC risk is modified by GERD. In total, 309 EAC patients and 279 frequency-matched healthy controls underwent MMP1 1G/2G, MMP3 6A/5A, MMP12 −82A/G and MMP12 1082A/G genotyping. Questionnaires collected GERD history. EAC risk was analyzed using logistic regression, adjusted for key covariates and stratified by GERD. Joint effects models explored GERD severity and duration, whereas additional models explored genotype–GERD interactions in EAC risk. We determined that each MMP1 and MMP3 minor (variant) allele was independently associated with increased EAC risk (adjusted odds ratio (AOR) 3.2, 95% confidence interval (CI) 2.0–5.1, p < 0.001 and AOR 1.8, 95% CI 1.1–2.7, p = 0.01, respectively) only among those with GERD but not in GERD-free individuals (all p = nonsignificant). There were significant interactions between the MMP1 variants and the presence of GERD (p = 0.002) and between MMP3 variants and GERD (p = 0.04). There was an equally strong interaction between cumulative GERD severity and MMP1 (p = 0.002). The AOR of each variant allele was 14.9 (95% CI 1.6–136) for individuals with severe GERD, 1.7 (95% CI 1.0–2.7) for mild-moderate GERD and 0.98 (95% CI 0.7–1.4) for those without GERD. This was further reflected in separate analyses of frequency and duration of GERD. In conclusion, MMP1 1G/2G (and possibly MMP3 6A/5A) polymorphisms alter EAC risk differentially for GERD and GERD-free individuals.
PMCID: PMC3908453  PMID: 22422400
matrix metalloproteinase; gene polymorphism; gastroesophageal reflux disease; esophageal cancer
19.  Gender differences in the effect of occupational endotoxin exposure on impaired lung function and death: the Shanghai Textile Worker Study 
Airborne endotoxin exposure has both adverse and protective health effects. Studies show males have augmented acute inflammatory responses to endotoxin. In this longitudinal cohort study we investigated the effect of long-term exposure to endotoxin in cotton dust on health, and determined whether these effects differ by gender.
In the Shanghai Textile Worker Study, 447 cotton and 472 control silk textile workers were followed from 1981 to 2011 with repeated measures of occupational endotoxin exposure, spirometry, and health questionnaires. Impaired lung function was defined as a decline in forced expiratory volume in one second to less than the 5th percentile of population predicted. Death was ascertained by death registries. We used Cox proportional hazards models to assess the effect of endotoxin exposure on the time to development of impaired lung function and death.
128 deaths and 164 diagnoses of impaired lung function were ascertained between 1981 and 2011. Hazard ratios (HRs) for the composite endpoint of impaired lung function or death was 1.47 (95% CI 1.09-1.97) for cotton vs. silk workers and 1.04 (95% CI 1.01-1.07) per 10,000 endotoxin units (EU)/m3-years increase in exposure. HRs for all-cause mortality was 1.36 (95% CI 0.93-1.99) for cotton vs. silk workers and 1.04 (95% CI 0.99-1.08) per 10,000 EU/m3-years. The risk associated with occupational endotoxin exposure was elevated only in men.
Occupational endotoxin exposure is associated with an increase in the risk of impaired lung function and all-cause mortality in men.
PMCID: PMC4033669  PMID: 24297825
endotoxin; organic dust; gender; lung function; mortality
20.  Mitochondrial Variations in Non-Small Cell Lung Cancer (NSCLC) Survival 
Cancer Informatics  2015;14(Suppl 1):1-9.
Mutations in the mtDNA genome have long been suspected to play an important role in cancer. Although most cancer cells harbor mtDNA mutations, the question of whether such mutations are associated with clinical prognosis of lung cancer remains unclear. We resequenced the entire mitochondrial genomes of tumor tissue from a population of 250 Korean patients with non-small cell lung cancer (NSCLC). Our analysis revealed that the haplogroup (D/D4) was associated with worse overall survival (OS) of early-stage NSCLC [adjusted hazard ratio (AHR), 1.95; 95% CI, 1.14–3.33; Ptrend = 0.03]. By comparing the mtDNA variations between NSCLC tissues and matched blood samples, we found that haplogroups M/N and/or D/D4 were hotspots for somatic mutations, suggesting a more complicated mechanism of mtDNA somatic mutations other than the commonly accepted mechanism of sequential accumulation of mtDNA mutations.
PMCID: PMC4310616  PMID: 25657573
mitochondria genome; mitochondria mutations; lung cancer survival; haplogroup; mitochondrial genome resequencing
21.  Distinct and replicable genetic risk factors for acute respiratory distress syndrome of pulmonary or extrapulmonary origin 
Journal of medical genetics  2012;49(11):671-680.
The role of genetics in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) from direct or indirect lung injury has not been investigated specifically. The aim of this study was to identify genetic variants contributing to ARDS from pulmonary or extrapulmonary causes.
We conducted a multi-stage genetic association study. We first performed a large-scale genotyping (50K IBC Chip) in 1,717 Caucasian critically ill patients with either pulmonary or extrapulmonary injury, to identify single nucleotide polymorphisms (SNPs) associated with the development of ARDS from direct or indirect insults to the lung. Identified SNPs (p ≤ 0.0005) were validated in two separated populations (Stage II), with trauma (Population I; n = 765) and pneumonia/pulmonary sepsis (Population II; n = 838), as causes for ARDS/ALI. Genetic variants replicating their association with trauma related-ALI in Stage II were validated in a second trauma-associated ALI population (n = 224, Stage III).
In Stage I, non-overlapping SNPs were significantly associated with ARDS from direct/indirect lung injury, respectively. The association between rs1190286 (POPDC3) and reduced risk of ARDS from pulmonary injury was validated in Stage II (p < 0.003). SNP rs324420 (FAAH) was consistently associated with increased risk of ARDS from extrapulmonary causes in two independent ALI-trauma populations (p < 0.007, Stage II; p < 0.05, Stage III). Meta-analysis confirmed these associations.
Different genetic variants may influence ARDS susceptibility depending on direct vs indirect insults. Functional SNPs in POPDC3 and FAAH genes may be driving the association with direct and indirect ALI, respectively.
PMCID: PMC3654537  PMID: 23048207
acute respiratory distress syndrome; acute lung injury; pulmonary/extrapulmonary injury; single-nucleotide polymorphism; genetic susceptibility profile; large scale genomic association study; replication
Telomeres are genomic structures that reflect both mitotic history and biochemical trauma to the genome. Metals inherent in fine particulate matter (PM2.5) were shown to be genotoxic via oxidative damage. However, few studies investigated the induction time of cumulative PM2.5 exposure on telomere length in a longitudinal setting. Therefore, the purpose of this study was to assess the association between occupational PM2.5 exposure in various time windows and telomere length. The study population consisted of 48 boilermakers and the follow-up period was 8 yr. The main exposures were cumulative occupational PM2.5 in the month, year, and career prior to each blood draw, assessed via work history questionnaires and area air measures. Repeated telomere length measurements from leukocytes were assessed via real-time quantitative polymerase chain reaction (qPCR). Analysis was performed using linear mixed models controlling for confounders and white blood cell differentials. Cumulative PM2.5 exposure was treated continuously and categorized into quartiles, in separate analyses. At any follow-up time, for each milligram per cubic meter per hour increase in cumulative PM2.5 exposure in the prior month, there was a statistically significant decrease in relative telomere length of −0.04 units. When categorizing the exposure into quartiles, there was a significant negative association between telomere length and highest quartile of cumulative PM2.5 exposure in the prior month (−0.16). These findings suggest that genomic trauma to leukocyte telomeres was more consistent with recent occupational PM2.5 exposure, as opposed to cumulative exposure extending into the distant past.
PMCID: PMC4072226  PMID: 24627998
23.  Rare variants of large effect in BRCA2 and CHEK2 affect risk of lung cancer 
Wang, Yufei | McKay, James D. | Rafnar, Thorunn | Wang, Zhaoming | Timofeeva, Maria | Broderick, Peter | Zong, Xuchen | Laplana, Marina | Wei, Yongyue | Han, Younghun | Lloyd, Amy | Delahaye-Sourdeix, Manon | Chubb, Daniel | Gaborieau, Valerie | Wheeler, William | Chatterjee, Nilanjan | Thorleifsson, Gudmar | Sulem, Patrick | Liu, Geoffrey | Kaaks, Rudolf | Henrion, Marc | Kinnersley, Ben | Vallée, Maxime | LeCalvez-Kelm, Florence | Stevens, Victoria L. | Gapstur, Susan M. | Chen, Wei V. | Zaridze, David | Szeszenia-Dabrowska, Neonilia | Lissowska, Jolanta | Rudnai, Peter | Fabianova, Eleonora | Mates, Dana | Bencko, Vladimir | Foretova, Lenka | Janout, Vladimir | Krokan, Hans E. | Gabrielsen, Maiken Elvestad | Skorpen, Frank | Vatten, Lars | Njølstad, Inger | Chen, Chu | Goodman, Gary | Benhamou, Simone | Vooder, Tonu | Valk, Kristjan | Nelis, Mari | Metspalu, Andres | Lener, Marcin | Lubiński, Jan | Johansson, Mattias | Vineis, Paolo | Agudo, Antonio | Clavel-Chapelon, Francoise | Bueno-de-Mesquita, H.Bas | Trichopoulos, Dimitrios | Khaw, Kay-Tee | Johansson, Mikael | Weiderpass, Elisabete | Tjønneland, Anne | Riboli, Elio | Lathrop, Mark | Scelo, Ghislaine | Albanes, Demetrius | Caporaso, Neil E. | Ye, Yuanqing | Gu, Jian | Wu, Xifeng | Spitz, Margaret R. | Dienemann, Hendrik | Rosenberger, Albert | Su, Li | Matakidou, Athena | Eisen, Timothy | Stefansson, Kari | Risch, Angela | Chanock, Stephen J. | Christiani, David C. | Hung, Rayjean J. | Brennan, Paul | Landi, Maria Teresa | Houlston, Richard S. | Amos, Christopher I.
Nature genetics  2014;46(7):736-741.
We conducted imputation to the 1000 Genomes Project of four genome-wide association studies of lung cancer in populations of European ancestry (11,348 cases and 15,861 controls) and genotyped an additional 10,246 cases and 38,295 controls for follow-up. We identified large-effect genome-wide associations for squamous lung cancer with the rare variants of BRCA2-K3326X (rs11571833; odds ratio [OR]=2.47, P=4.74×10−20) and of CHEK2-I157T (rs17879961; OR=0.38 P=1.27×10−13). We also showed an association between common variation at 3q28 (TP63; rs13314271; OR=1.13, P=7.22×10−10) and lung adenocarcinoma previously only reported in Asians. These findings provide further evidence for inherited genetic susceptibility to lung cancer and its biological basis. Additionally, our analysis demonstrates that imputation can identify rare disease-causing variants having substantive effects on cancer risk from pre-existing GWAS data.
PMCID: PMC4074058  PMID: 24880342
25.  MTHFR Polymorphisms, Folate Intake, and Carcinogen DNA Adducts in the Lung 
The methylenetetrahydrofolate reductase (MTHFR) genes and folate in one-carbon metabolism are essential for DNA methylation and synthesis. However, their role in carcinogen DNA damage in target lung tissue, a dosimeter for cancer risk, is not known. Our study aimed to investigate the association between genetic and nutritional one-carbon metabolism factors and DNA adducts in target lung. Data on 135 lung cancer cases from the Massachusetts General Hospital were studied. Genotyping was completed for MTHFR C677T (rs1801133) and A1298C (rs1801131). Information on dietary intake for one-carbon related micronutrients, folate and other B vitamin, was derived from a validated food frequency questionnaire. DNA adducts in lung were measured by 32P-postlabeling. After adjusting for potential confounders, DNA adduct levels in lung significantly increased by 69.2% [95% confidence interval (CI), 5.5% to 171.5%] for the MTHFR 1298AC+CC genotype. The high risk group, combining the A1298C (AC+CC) plus C677T (CT+TT) genotypes, had significantly enhanced levels of lung adducts by 210.7% (95% CI, 21.4% to 695.2%) in contrast to the A1298C (AA) plus C677T (CC) genotypes. Elevation of DNA adduct was pronounced - 111.3% (95% CI, −3.0 to 360.5%) among 1298AC+CC patients who consumed the lowest level of folate intake as compared with 1298AA individuals with highest tertile of intake. These results indicate that DNA adducts levels are influenced by MTHFR polymorphisms and low folate consumption, suggesting an important role of genetic and nutritional factors in protecting DNA damage from lung carcinogen in at-risk populations.
PMCID: PMC3293105  PMID: 22052259
MTHFR; folate; genetic polymorphisms; DNA adducts; one carbon metabolism

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