Measurement of urinary arsenic profiles and DNA hypomethylation in a case-control study of urothelial carcinoma.

Environmental exposure to arsenic may be involved in the disturbance of DNA hypomethylation. The aim of this study is the first to explore the effect of interactions of urinary total arsenic levels, arsenic methylation capacity, 8-hydroxy-2'-deoxyguanosine (8-OHdG), plasma folate, and global 5-methyl-2'-deoxycytidine (5-MedC) levels on the risk of urothelial carcinoma (UC). A hospital-based case-control study was constructed. The research involved the histological recruitment and pathological verification of 178 UC patients and 356 age-/sex-matched controls without prior history of cancer. Arsenic species were determined by high-performance liquid chromatography (HPLC)-hydride generation and atomic absorption. 5-MedC levels were detected by HPLC and triple-quadrupole mass spectrometry (MS). 8-OHdG was processed by an online solid-phase extraction LC-MS/MS. Plasma folate levels were measured using the chemiluminescent technology. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multiple logistic regression analysis. Results indicate that the high levels of total urinary arsenic, inorganic arsenic percentage, and 8-OHdG and the low levels of DMA % and plasma folate were independent factors of UC. In addition, global 5-MedC levels in the first quartile versus fifth quartile significantly increased the twofold OR of UC after potential factors were adjusted (95% CI:1.10-4.03). The interaction of 5-MedC level and high total arsenic level, insufficient arsenic capacity, high 8-OHdG, and low folate levels was insignificant. Results of stepwise logistic regression analysis indicate that high total urinary arsenic levels (Q3 versus Q1), low plasma folate level, and low global 5-MedC (Q4 versus Q5) significantly increased the ORs of UC. The above results suggest that high total arsenic, low plasma folate, and 5-MedC levels affect the ORs of UC independently.

Novel vinylene-based covalent organic framework as a promising adsorbent for the rapid extraction of beta-agonists in meat samples.

Beta-agonists are potent bronchodilators approved for the treatment of asthma and tocolysis. However, they have been extensively misused as feed additives in the veterinary field to improve feed efficiency. The concern over their potential hazard to health has come to the fore again. In this study, a novel vinylene-based covalent organic framework (V-COF-1) with a two-dimensional structure was developed. The structure shows good tolerance in a variety of mediums, which can be attributed to the low polarity linkage. The high specific surface area and variable interaction with analytes accelerate the extraction time. Furthermore, the swelling resulting from the formation of hydrogen bonds by the protic solvent intercalation with the triazine group also improves the adsorption efficiency. Finally, due to its great reusability, it is economical material in sample preparation application. The V-COF-1 based µ-dSPE approach was coupled with UHPLC-MS/MS to develop a highly sensitive and selective method. The linearity of the method ranged from 0.05 to 20 ng g-1 with a correlation coefficient (R2) higher than 0.9958, and the limits of detection and quantification fell in the ranges of 0.01-0.10 ng g-1 and 0.04-0.32 ng g-1. The proposed method has been successfully applied to determine beta-agonists in meat samples, and the results indicated good recovery of 82.2-116%. The intra-day and inter-day precision were less than 6.61%, indicating the potential for sustainable application in food analysis.

Rapid microwave synthesis of MOF microrods: Dispersive SPE coupled with UHPLC-MS/MS to determine fluoroquinolones in honey.

A novel sorbent Cu-S metal-organic framework (MOF) microrods was prepared for dispersive solid-phase extraction via microwave synthesis and used to determine 12 fluoroquinolones (FQs) in honey samples employing ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The best extraction efficiency was achieved by optimizing sample pH, sorbent quantity, eluent type/volume, and extraction and elution time. The proposed MOF exhibits advantages such as rapid synthesis time (20 min) and outstanding adsorption ability toward zwitterionic FQs. These advantages can be attributed to multiple interactions, including hydrogen bonding, π-π interaction, and hydrophobic interaction. The limits of detection of analytes were 0.005-0.045 ng g-1. Acceptable recoveries (79.3%-95.6%) were obtained under the optimal conditions. Precision (relative standard deviation, RSD) was <9.2%. These results demonstrate the utility of our sample preparation method and the high capacity of Cu-S MOF microrods for rapid and selective extraction of FQs from honey samples.

Lipid peroxidation metabolites associated with biomarkers of inflammation and oxidation stress in workers handling carbon nanotubes and metal oxide nanoparticles.

The purpose of this study was to assess the effects of lipid peroxidation with occupational exposure to different types of nanomaterials (NMs). In this cross-sectional study, urine and exhaled breath condensate (EBC) samples were collected from 80 NM-handling workers [30 workers handling nano-titanium oxide (nano-TiO2), 28 handling nano-silicon dioxide (nano-SiO2), 22 handling carbon nanotubes (CNTs)], and 69 controls (office workers) from 2010 to 2012. Urinary 8-isoPGF2α, 2,3 dinor-8-isoPGF2α, PGF2α, and EBC 8-iso PGF2α were measured as lipid peroxidation biomarkers in 2013. A significant positive correlation was found between 8-isoPGF2α, 2,3 dinor-8-isoPGF2α, PGF2α, and total isoprostane in urine. Furthermore, significant positive correlations were noted between EBC 8-iso PGF2α and urinary 2,3 dinor-8-isoPGF2α (Spearman correlation r = 0.173, p = 0.035). Exposure to nano-TiO2 resulted in significantly higher levels of urinary 8-isoPGF2α, 2,3 dinor-8-isoPGF2α and PGF2α, even after controlling for confounding factors. Moreover, significant associations and exposure intensity-response relationships between EBC 8-iso PGF2α and NMs were observed in workers, whether handling nano-TiO2, nano-SiO2, or CNTs. Among them, the significant trends were identified based on the intensity of risk levels. These results provided evidence that exposure to nano-TiO2, nano-SiO2, and CNTs may lead to lipid peroxidation in EBC. For routine biomonitoring purposes, this finding, which came through noninvasive methods, may be useful for workers exposed to NMs.HighlightsData regarding the effects of nano-titanium oxide (nano-TiO2), nano-silicon dioxide (nano-SiO2), and carbon nanotubes (CNTs) on lipid peroxidation in workers are limited.8-Iso PGF2α in exhaled breath condensate of workers exposed to nanoparticles was higher than that of office workers.Exposure to titanium oxide (TiO2) and silica (SiO2) may lead to lipid peroxidation, as indicated by 8-isoPGF2α, 2,3 dinor-8-isoPGF2α, and PGF2α.Examination of lipid peroxidation in EBC has seems to be a useful technique for noninvasive monitoring of workers exposed to nanoparticles.

The association between urinary levels of 1,3-butadiene metabolites, cardiovascular risk factors, microparticles, and oxidative stress products in adolescents and young adults.

1,3-Butadiene (BD) is a synthetic colorless gas used in the production of synthetic rubber and polymers. Exposure to BD has been reported to increase oxidative stress and accelerate atherosclerosis in vitro and in animal studies. In occupational studies, BD exposure has been linked to cardiovascular disease (CVD). However, no previous research has been reported on whether BD exposure is associated with CVD risk factors and oxidative stress in the general population. We recruited 853 young participants to study the correlation between urinary levels of the BD metabolite, N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), CVD risk factors, serum levels of endothelial microparticles and platelet microparticles, and the urinary levels of 8-hydroxydeoxyguanosine (8-OHdG). The results showed the DHBMA levels were positively correlated with low-density lipoprotein-C, carotid intima-media thickness (CIMT), CD31+/CD42a - counts (endothelial apoptosis markers), and urinary 8-OHdG levels. Moreover, DHBMA levels were negatively correlated with CD62 P counts (platelet activation marker). The correlation between DHBMA, CIMT, and 8-OHdG was more evident when the levels of CD31+/CD42a - or CD62 P were above 50%. In conclusion, we reported that the urinary levels of DHBMA were associated with the lipid profile, CIMT, microparticles, and marker of oxidative stress in this young population. Future studies on BD exposure and atherosclerosis are needed.

Relationships among cigarette smoking, urinary biomarkers, and urothelial carcinoma risk: a case-control study.

Cigarette smoke is a known risk factor for urothelial carcinoma (UC). However, there is limited information about the distributions and effects of volatile organic compounds (VOCs) on smoking-related UC risk. With this hospital-based case-control study, we explored the associations between urinary levels of cotinine and VOC metabolites (acrylamide, 1,3-butadiene, and benzene) and the risk of UC. Urological examinations and pathological verifications were used to confirm the diagnoses of UC. All study participants provided smoking-related information via questionnaires and face-to-face interviews; they also provided urine samples for the measurement of VOC metabolites, cotinine, and 8-hydroxydeoxyguanosine (8-OHdG), which was used as an indicator of oxidative stress. We applied multiple logistic regression analysis to estimate the risk of UC, and we found that levels of urinary cotinine and 8-OHdG were higher in the UC group than in the control group. Furthermore, urinary levels of VOC metabolites, including N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA), N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine, N-acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine-3, trans,trans-muconic acid (t,t-MA), and S-phenylmercapturic acid (SPMA), increased with increasing levels of urinary cotinine. After adjusting for potential risk factors, dose-response relationships were observed between UC risk and urinary levels of AAMA, t,t-MA, SPMA, and 8-OHdG. Participants with high urinary levels of cotinine, AAMA, t,t-MA, SPMA, and 8-OHdG had risks of UC that were 3.5- to 6-fold higher than those of participants with lower levels. Future, large-scale investigations of the risks of UC should be explored, and repeated measurement of VOC metabolites should be assessed.

The associations among lead exposure, bone mineral density, and FRAX score: NHANES, 2013 to 2014.

Lead exposure has been suspected as a risk factor for osteoporosis. However, in epidemiological studies, the association between environmental lead exposure and bone health were inconsistent. With the decrease of lead exposure in recent decades, we evaluated the association between lead exposure and bone mineral density (BMD) in the general US population in this study. We analyzed data on 1859 adults (aged ≥40 years) from the National Health and Nutrition Examination Survey (NHANES) conducted in 2013-2014 to determine the relationship among lead exposure measured by both blood and urine lead concentration, BMD of total spine and femur, and FRAX score in a cross-sectional study. In premenopausal women, the results showed a 1-unit increase in natural log-transformed blood and urine lead levels was associated with a decrease in total femur BMD of 0.061 g/cm2 (S.E. = 0.015; p = 0.001) and 0.046 g/cm2 (S.E. = 0.018; p = 0.020), respectively. Moreover, in premenopausal women, a 1-unit increase in natural log-transformed blood level was associated with a decrease in total spine BMD of 0.054 g/cm2 (S.E. = 0.019; p = 0.013). Both FRAX scores were positively correlated with blood and urine lead levels in subjects without fractures, while the 10-year hip fracture risk score was positively associated with lead exposure in subjects with a history of fracture or vertebral fracture. In conclusion, lead exposure was associated with decreased total femur and spine BMD, and FRAX score in the general US population. Further research is needed to elucidate the causal relationship among lead exposure, BMD, and fracture risk.

Global DNA methylation and oxidative stress biomarkers in workers exposed to metal oxide nanoparticles.

This is the first study to assess global methylation, oxidative DNA damage, and lipid peroxidation in workers with occupational exposure to metal oxide nanomaterials (NMs). Urinary and white blood cell (WBC) 8-hydroxydeoxyguanosine (8-OHdG), and exhaled breath condensate (EBC) 8-isoprostane were measured as oxidative stress biomarkers. WBC global methylation was measured as an epigenetic alteration. Exposure to TiO2, SiO2, and indium tin oxide (ITO) resulted in significantly higher oxidative biomarkers such as urinary 8-OHdG and EBC 8-isoprostane. However, significantly higher WBC 8-OHdG and lower global methylation were only observed in ITO handling workers. Significant positive correlations were noted between WBC and urinary 8-OHdG (Spearman correlation r=0.256, p=0.003). Furthermore, a significant negative correlation was found between WBC 8-OHdG and global methylation (r=-0.272, p=0.002). These results suggest that exposure to metal oxide NMs may lead to global methylation, DNA oxidative damage, and lipid peroxidation.