Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-12 (of 12 Records) |
Query Trace: Jain RB[original query] |
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Association of caffeine consumption and smoking status with the serum concentrations of polychlorinated biphenyls, dioxins, and furans in the general U.S. population: NHANES 2003-2004
Jain RB , Wang RY . J Toxicol Environ Health A 2011 74 (18) 1225-39 Smoking appears to enhance the body's clearance of dioxins and dioxin-like polychlorinated biphenyls (PCB) by inducing CYP1A2 activity based on studies with a limited number of participants. This hypothesis was evaluated by using data from National Health and Nutrition Examination Survey. Specifically, adult participants were identified and the sums of their serum lipid-adjusted concentrations of 12 polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) congeners, 33 PCB (total), 26 non-dioxin-like PCB, and 6 mono-ortho (dioxin-like) PCB were determined. In addition to evaluating the association of smoking, the association of caffeine consumption and the interaction between them was evaluated. Data analysis included regression models that were fitted with age, gender, race/ethnicity, and body mass index (BMI). R(2) varied from 34.8 to 66%. Smokers had significantly lower concentrations of total PCDD/PCDF than nonsmokers. New to this study, a siginificant interaction between caffeine consumption and smoking for total PCB was found. When caffeine was consumed less than once a day, smokers had higher concentrations of total PCB than nonsmokers. However, when caffeine was consumed at least once a day, smokers had lower concentrations than nonsmokers. A significant interaction between age and caffeine consumption frequency for each of the PCB groups was also observed. The differences in concentration between younger and older age groups were greater when caffeine was consumed at least once a day than when caffeine was consumed less frequently. Smoking and caffeine consumption need to be considered in the interpretation of human biomonitoring data because they appear to affect the serum concentrations of these chemicals. |
Tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in smokers in the United States: NHANES 2007-2008
Xia Y , Bernert JT , Jain RB , Ashley DL , Pirkle JL . Biomarkers 2010 16 (2) 112-9 The tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), has been measured in urine samples from all participants aged 6 years and older from the National Health and Nutrition Examination Survey 2007-2008. Participants with a serum cotinine concentration of ≥10 ng/mL were identified as tobacco users, primarily cigarette smokers. Regression models were developed to calculate geometric mean NNAL concentrations adjusted for serum cotinine, urinary creatinine, cigarettes per day, and Federal Trade Commission tar values of the cigarettes smoked. Significant differences were found by gender (p = 0.003) and race/ethnicity (p = 0.022 for non-Hispanic white versus non-Hispanic black smokers), but not by menthol type of the cigarettes. Females and non-Hispanic white smokers had the highest adjusted means for urinary NNAL (353 and 336 pg/mL, respectively). The results from this study demonstrated significant relationships between NNAL concentrations and serum cotinine (p < 0.001) and urine creatinine (p < 0.001). The joint effect of linear and quadratic terms for number of cigarettes smoked per day was also statistically significant (p = 0.001). In addition to addressing current NNK exposure levels, these results will form a baseline for future estimates of tobacco users' exposure to this carcinogen. |
Perchlorate, nitrate, and iodide intake through tap water
Blount BC , Alwis KU , Jain RB , Solomon BL , Morrow JC , Jackson WA . Environ Sci Technol 2010 44 (24) 9564-70 Perchlorate is ubiquitous in the environment, leading to human exposure and potential impact on thyroid function. Nitrate can also competitively inhibit iodide uptake at the sodium-iodide symporter and thus reduce thyroid hormone production. This study investigates the intake of perchlorate, nitrate, and iodide attributable to direct and indirect tap water consumption. The National Health and Nutrition Examination Survey collected tap water samples and consumption data from 3262 U.S. residents during the years 2005-2006. The median perchlorate, nitrate, and iodide levels measured in tap water were 1.16, 758, and 4.55 mug/L, respectively. Measured perchlorate levels were below the United States Environmental Protection Agency (U.S. EPA) drinking water equivalent level for perchlorate (24.5 mug/L). Significant correlations were found between iodide and nitrate levels (r = 0.17, p < 0.0001) and perchlorate and nitrate levels (r = 0.25, p < 0.0001). On the basis of 24 h recall, 47% of the study participants reported drinking tap water; 89% reported either direct or indirect consumption of tap water. For the adult population (age ≥ 20 yrs) the median tap water consumption rate was 11.6 mL/kg-day. Using individual tap water consumption data and body weight, we estimated the median perchlorate, nitrate, and iodide dose attributable to tap water as 9.11, 11300, and 43.3 ng/kg-day, respectively, for U.S. adults. This perchlorate exposure dose from tap water is relatively small compared to the total perchlorate exposure dose previously characterized for the U.S. adults (median 64 ng/kg-day) and the U.S. EPA reference dose (700 ng/kg-day). |
Urine concentrations of a tobacco-specific nitrosamine carcinogen in the U.S. population from secondhand smoke exposure
Bernert JT , Pirkle JL , Xia Y , Jain RB , Ashley DL , Sampson EJ . Cancer Epidemiol Biomarkers Prev 2010 19 (11) 2969-77 BACKGROUND: The tobacco-specific nitrosamine NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) and its reduction product in the body, NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), are potent pulmonary carcinogens. We have measured total NNAL in the U.S. population of tobacco users and nonsmokers exposed to secondhand smoke (SHS). METHODS: We measured total urinary NNAL (free NNAL plus its glucuronides following hydrolysis) by using a sensitive and specific high-performance liquid chromatography / tandem mass spectrometry method. We calculated the percentage above the LOD, the 50th through 95th percentiles, and in some cases geometric means for groups classified by age, gender and race/ethnicity. RESULTS: Total urinary NNAL was measureable at or above its limit of detection (0.6 pg/mL) in 55% of the study participants, including 44% of nonsmokers. The population distribution of urinary NNAL included smoker and nonsmoker regions similar to the bimodal distribution of serum cotinine, and serum cotinine and total urinary NNAL were strongly correlated (r = 0.92; p<0.001). Among nonsmokers, children had significantly higher concentrations of NNAL than did adults aged ≥20 years (p < 0.001). CONCLUSIONS: Among NHANES participants, total NNAL was found at measurable levels in the urine of 44% of nonsmokers, and in 87.5% of those with substantial SHS exposure (with serum cotinine concentrations of 0.1 to 10 ng/mL). Children aged 6-11 years had the highest NNAL concentrations among all nonsmokers. IMPACT: We describe for the first time the distribution of total urinary NNAL in the entire U.S. population including both smokers and nonsmokers. NNAL was detected in 44% of all nonsmokers. |
Effect of differing levels of tobacco-specific nitrosamines in cigarette smoke on the levels of biomarkers in smokers
Ashley DL , O'Connor RJ , Bernert JT , Watson CH , Polzin GM , Jain RB , Hammond D , Hatsukami DK , Giovino GA , Cummings KM , McNeill A , Shahab L , King B , Fong GT , Zhang L , Xia Y , Yan X , McCraw JM . Cancer Epidemiol Biomarkers Prev 2010 19 (6) 1389-98 BACKGROUND: Smokers are exposed to significant doses of carcinogens, including tobacco-specific nitrosamines (TSNA). Previous studies have shown significant global differences in the levels of TSNAs in cigarette smoke because of the variation in tobacco blending and curing practices around the world. METHODS: Mouth-level exposure to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) measured in cigarette butts and urinary concentrations of its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were examined among 126 daily smokers in four countries over a 24-hour study period. RESULTS: As mouth-level exposure of NNK increased, the urinary NNAL increased even after adjustment for other covariates (beta = 0.46, P = 0.004). The relationship between mouth-level exposure to nicotine and its salivary metabolite, cotinine, was not statistically significant (beta = 0.29, P = 0.057), likely because of the very limited range of differences in mouth-level nicotine exposure in this population. CONCLUSIONS: We have shown a direct association between the 24-hour mouth-level exposure of NNK resulting from cigarette smoking and the concentration of its primary metabolite, NNAL, in the urine of smokers. Internal dose concentrations of urinary NNAL are significantly lower in smokers in countries that have lower TSNA levels in cigarettes such as Canada and Australia in contrast to countries that have high levels of these carcinogens in cigarettes, such as the United States. Impact: Lowering the levels of NNK in the mainstream smoke of cigarettes through the use of specific tobacco types and known curing practices can significantly affect the exposure of smokers to this known carcinogen. (c)2010 AACR. |
A recursive version of Grubbs' test for detecting multiple outliers in environmental and chemical data
Jain RB . Clin Biochem 2010 43 (12) 1030-3 OBJECTIVE: To compare the performance of Grubbs' outlier detection procedure with recursive Extreme Studentized Deviate (ESD) outlier detection procedure. DESIGN AND METHODS: Using simulated data, the powers of Grubbs' and ESD procedures were evaluated. RESULTS: Except when the sample contained exactly one outlier, the power of ESD procedure was higher than that of Grubbs' procedure. CONCLUSION: The ESD recursive procedure is the procedure of choice to detect multiple outliers in environmental and chemical data. |
Regression models to predict corrected weight, height and obesity prevalence from self-reported data: data from BRFSS 1999-2007
Jain RB . Int J Obes (Lond) 2010 34 (11) 1655-64 BACKGROUND: Surveys such as the Behavioral Risk Factor Surveillance System (BRFSS) collect only self-reported data on height and weight to estimate obesity prevalence rates. Because of biased self-reporting of height and weight, obesity prevalence rates reported by these surveys are too low. OBJECTIVE: To develop regression models that can predict corrected height, weight and obesity prevalence from self-reported data, as well as to compare obesity prevalence rates based on self-reported and modeled data and test for trends in obesity prevalence by gender, age and race/ethnicity. DESIGN: Data from the National Health and Nutrition Examination Survey (NHANES) for the period 1999-2006 were used to develop regression models to predict corrected height, weight and obesity prevalence. Regression coefficients estimated from these models were used to predict corrected height, weight and obesity prevalence for BRFSS data for 1999-2007. RESULTS: Self-reported weights for males were higher by 0.1-0.2 kg and lower by about 1.25 kg than corrected weights for females. Underreporting of weights was lowest for Hispanics when compared with other race/ethnicities. In addition, underreporting of weight increased with an increase in body mass index. Self-reported heights for males were higher than corrected heights by about 2 cm, and for females, by about 1 cm. Overreporting of height increased with an increase in age. Self-reported obesity prevalence was 4.5-5.8% lower than corrected rates for males and by 4.4-5.1% for females. Underreporting of obesity prevalence increased with an increase in age. Obesity prevalence rates increased over time for each gender, race/ethnicity and age group for BRFSS data. CONCLUSION: Obesity prevalence calculated from self-reported data is too low and should be used with caution for health-care planning purposes. When it is not possible to have measured data, corrected heights and weights may be predicted by using models such as those presented by us from a relatively large data set that has both measured and self-reported data. International Journal of Obesity advance online publication, 13 April 2010; doi:10.1038/ijo.2010.80. |
Effect of body mass index and total blood volume on serum cotinine levels among cigarette smokers: NHANES 1999-2008
Jain RB , Bernert JT . Clin Chim Acta 2010 411 1063-8 INTRODUCTION: Body mass index (BMI) and total blood volume are not always considered as variables that affect serum cotinine concentrations. METHOD: We used data from the National Health and Nutrition Examination Survey (NHANES) for the years 1999-2008 and fitted regression models for smokers. In addition to traditionally used covariates like age, race, gender, and average number of cigarettes smoked daily, we used BMI and total blood volume (TBV) as continuous variables to evaluate the impact of these variables on serum cotinine levels. RESULTS: Adjusted serum cotinine levels increased statistically significantly with increase in age (p<0.001). Serum cotinine levels increased statistically significantly (p<0.001) with average number of cigarettes smoked daily. Levels of adjusted serum concentrations from high to low by race/ethnicity were: non-Hispanic blacks, non-Hispanic whites, other race/ethnicity, and Mexican-Americans; and all differences were statistically significant. A model of serum cotinine including BMI without TBV found BMI to be a significant predictor (p<0.001) and similarly a model including TBV without BMI found TBV to be a significant predictor (p<0.001). When BMI and TBV were both included in the model, the significance of BMI changed markedly (p=0.93) with substantive changes in the BMI coefficient and the significance of TBV changed also (p=.024) with small change in the TBV coefficient. DISCUSSION: TBV and BMI are significant predictors of serum cotinine concentrations. TBV or BMI, but not both, should be included in predictive models of serum cotinine concentrations. |
Regression models to estimate total polychlorinated biphenyls in the general US population: 2001-2002 and 2003-2004
Jain RB , Wang RY . Chemosphere 2010 79 (3) 243-52 Certain polychlorinated biphenyls (PCB) have long half-lives and, despite the regulatory bans on the industrial pollutants that expose humans to PCB, are detectable in human serum. However, many of them are not detectable because of the small quantities that may be present in body fluids. For this reason, attempts have been made to estimate the total concentration of PCB (SigmaPCB) using the relationship between SigmaPCB and the concentrations of a few of the PCB congeners which can be reliably measured at detectable levels. PCB 153 or a combination of PCB 153,138, and 180 have previously been used for this purpose. However, because of the unique populations investigated in these studies, the results are not necessarily applicable to the racially/ethnically heterogeneous US population. We defined SigmaPCB as the sum of the concentrations of 12 PCB congeners, and sum of 33 PCB congeners for NHANES 2001-2002 and 2003-2004 respectively. We built regression models in a step-wise fashion using SigmaPCB as the dependent variable and age, race/ethnicity, and gender as the covariates for both whole-weight and lipid-adjusted data. In addition, concentration of PCB 153 was used as the continuous independent variable for 2001-2002 models, and PCB 153 and PCB 180 for 2003-2004 models respectively. R(2) for both models for NHANES 2001-2002 was >86%. The R(2) for both NHANES 2003-2004 models was >81%. Thus, the estimate of SigmaPCB for the general US population can be improved by considering common demographic variables, such as race/ethnicity, and selected congeners. |
Comparison of three weighting schemes in weighted regression analysis for use in a chemistry laboratory
Jain RB . Clin Chim Acta 2009 411 270-9 BACKGROUND: To minimize the effect of heteroscedasticity in chemical and other data, weighted regression analysis is the preferred regression technique. In this work a regression weight that maximizes accuracy and precision was sought. METHOD: Using real and simulated data from a serum cotinine assay, performance of 3 weighting schemes, namely, 1/X, 1/X(2), and 1/s(2)(Y) to calibrate chemical data was evaluated. Two performance measures were used to evaluate the accuracy and precision of each scheme to estimate concentrations in unknown specimens. RESULTS: The weight, 1/X-particularly for low concentrations-was not acceptable. The performance of both, 1/X(2) and 1/s(2)(Y) was close, 1/X(2) being slightly better in many cases. Overall, however, when the variance of instrument signal increased beyond certain limits, none of the weighting schemes performed acceptably. CONCLUSION: Because of its simplicity and ease of use, 1/X(2) is recommended for general application. If, however, instrument signal variance is too high to be managed by statistical techniques, the only solution is to control such variance through laboratory-based solutions. |
A simple methodology to analyze inter-laboratory data: a simulation study
Jain RB . Clin Chim Acta 2009 410 79-84 BACKGROUND: Inter-laboratory experiments are conducted to assess how accurately and reproducibly various laboratories using different methods, instruments, analysts, and/or sample preparation procedures can perform measurements, in this case, the concentration of a chemical. In this work a 3-step methodology is proposed to analyze inter-laboratory experiments. METHODS: A simulation study based on 500 simulations was conducted for a cluster of 12 laboratories with different population means and SDs. The sample sizes varied from 10 to 50. Laboratories with too high a variance or too high a mean were recursively identified and removed by analysis of variance techniques. Outliers were identified and removed by a recursive algorithm. The remaining data were used to compute consensus mean, SD, repeatability, reproducibility, and CV for repeatability and reproducibility. RESULTS: Two laboratories with too high a variance were always identified for removal when the sample size was ≥20. Two laboratories with too high a mean were almost always identified irrespective of sample size. The average observed percent bias was never >+/-3.2% irrespective of the sample size. The average percent imprecision was also within +/-10.4% for all laboratories. The average CV was close to what was expected. CONCLUSIONS: With an optimal sample size of 20, the 3-step methodology presented here will adequately identify laboratories with variances or means that are too high or too low. |
Serum concentrations of selected persistent organic pollutants in a sample of pregnant females and changes in their concentrations during gestation
Wang RY , Jain RB , Wolkin AF , Rubin CH , Needham LL . Environ Health Perspect 2009 117 (8) 1244-9 OBJECTIVES: In this study we evaluated the concentrations of selected persistent organic pollutants in a sample of first-time pregnant females residing in the United States and assessed differences in these concentrations in all pregnant females during gestation. METHODS: We reviewed demographic and laboratory data for pregnant females participating in the National Health and Nutrition Examination Survey, including concentrations of 25 polychlorinated biphenyls (PCBs), 6 polychlorinated dibenzo-p-dioxins (PCDDs), 9 polychlorinated dibenzofurans (PCDFs), and 9 organochlorine pesticides. We report serum concentrations for first-time pregnant females (2001-2002; n = 49) and evaluate these concentrations in all pregnant females by trimester (1999-2002; n = 203) using a cross-sectional analysis. RESULTS: The chemicals with >or= 60% detection included PCBs (congeners 126, 138/158, 153, 180), PCDDs/PCDFs [1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1234678HpCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (123678HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzofuran (1234678HpCDF), 1,1'-(2,2-dichloroethenylidene)-bis(4-chlorobenzene) (p,p'-DDE)], and trans-nonachlor. The geometric mean concentration (95% confidence intervals) for 1234678HpCDD was 15.9 pg/g lipid (5.0-50.6 pg/g); for 123678HxCDD, 9.7 pg/g (5.5-17.1 pg/g); and for 1234678HpCDF, 5.4 pg/g (3.3-8.7 pg/g). The differences in concentrations of these chemicals by trimester were better accounted for with the use of lipid-adjusted units than with whole-weight units; however, the increase in the third-trimester concentration was greater for PCDDs/PCDFs (123678HxCDD, 1234678HpCDF) than for the highest concentration of indicator PCBs (138/158, 153, 180), even after adjusting for potential confounders. CONCLUSION: The concentrations of these persistent organic pollutants in a sample of first-time pregnant females living in the United States suggest a decline in exposures to these chemicals since their ban or restricted use and emission. The redistribution of body burden for these and other persistent organic pollutants during pregnancy needs to be more carefully defined to improve the assessment of fetal exposure to them based on maternal serum concentrations. Additional studies are needed to further the understanding of the potential health consequences to the fetus from persistent organic pollutants. |
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