Dynamic thiol disulfide homeostasis in painters as indices of oxidative stress.

This study was designed to determine thiol-disulfide homeostasis as indices of oxidative stress in painters by using a novel and automated colorimetric measurement method. Male painters (n = 117) were separated into three groups according to duration of work; group 1 (<5 years), group 2 (5-14 years) and group 3 (≥15 years). Hippuric acid, trichloroacetic acid (TCA), and phenol in urine was determined. Catalase activity and ischemia-modified albumin (IMA) levels were also assessed. Disulfide/Native Thiol and Disulfide/Total Thiol of group 2 and group 3 were significantly higher than those of group 1 (p < 0.001). A positive correlation was observed between urinary phenol and disulfide/native thiol (r = 0.214, p = 0.035), IMA (r = 0.305, p = 0.002), disulfide (r = 0.209, p = 0.040), and duration of work (r = 0.341, p < 0.001). The newly developed automated colorimetric method used in our study proposes a promising, practical and daily applicable test for evaluating oxidative status of painters.

Effect of chelation therapy on arrhythmogenic and basal ECG parameters of lead exposed workers.

Lead exposure has etiological role on cardiovascular system diseases as hypertension, atherosclerosis, stroke, and arrhythmic events. In this study, we aimed to compare the basal and arrhythmogenic ECG parameters of lead exposed workers before and after chelation therapy and to evaluate the effect of acute change of blood lead levels on ECG. Fourty consecutive occupationally lead exposed workers were enrolled, demographic, blood, echocardiographic, and electrocardiographic data's were analyzed before and after chelation therapy. Pmax, P min, P Wave Dispersion, and QT Dispersion values which are arrhythmia predictors were significantly lower after chelation therapy compared to values before chelation therapy. Lead exposed workers are under the risk of ventricular and atrial arrythmias and chelation treatment has a positive effect on these parameters.

Assessment of Diastolic Function and Thiol-Disulphide Homeostasis in Arsenic-Exposed Workers.

OBJECTIVES: Exposure to arsenic is associated with various cardiovascular diseases. The imbalance between antioxidant and oxidant homeostasis plays a crucial role in the cardiovascular effects of arsenic. The aim of this study was to investigate the effect of arsenic exposure on diastolic function by measuring thiol and disulphide in arsenic-exposed workers. METHODS AND RESULTS: A total of 107 male arsenic-exposed workers and 36 healthy subjects were enrolled. Mitral inflow velocity and parameters of diastolic function were measured. As oxidative stress indicators, total thiol, native thiol, disulphide, and their percent ratios were determined. The mean age was 39.1 ± 9.5 years in the arsenic-exposed group and 37.4 ± 9.6 years in the controls. The median blood arsenic level was 42 µg/dL in the arsenic-exposed group and 3.75 µg/dL in the controls. E-wave, E/A ratio, and e' wave were lower and left atrial diameter, A-wave, average E/e' ratio, and tricuspid regurgitation velocity were higher in the arsenic-exposed group. Native and total thiol concentrations were lower, and disulphide/native and disulphide/total thiol ratios were higher in the arsenic-exposed group. Fourteen (13.1%) workers had diastolic dysfunction, 26 (24.3%) had indeterminate, and 67 (62.6%) had normal diastolic function, compared to 1 (2.8%), 2 (5.6%), and 33 (97.7%) in the control group, respectively. In regression analysis, disulphide/native thiol ratio (p < 0.001) and blood arsenic level (p < 0.001) predicted increased average E/e' ratio in the arsenic-exposed group. CONCLUSIONS: This study showed strong associations among arsenic exposure, oxidative stress, and diastolic function, and revealed the influence of arsenic exposure on diastolic dysfunction through oxidative stress.

Assessment of potential cardiovascular risk in trichloroethylene exposure by serum methylated arginine levels.

Trichloroethylene (TCE) is a widely used solvent in industrial applications and has toxic effects on various systems. Methylated arginine amino acids (eg asymmetric dimethyl arginine (ADMA), symmetric dimethyl arginine (SDMA)) cause the development of cardiovascular disease by inhibiting NO synthesis, which is considered to be heart-protector. The aim of this study is to determine the risk of cardiovascular diseases in TCE exposure by methylated arginine biomarkers. About 98 controls and 100 TCE-exposed male subjects were included in the study. Trichloroacetic acid (urinary metabolite of TCE), arginine, homoarginine, citrulline ADMA, SDMA, and N-monomethyl L-arginine (L-NMMA) levels were found significantly higher than control group (p < 0.001). The strongest correlation was found between ADMA and Trichloroacetic acid (TCA) level (r = 0.453, p < 0.01). Long-term TCE exposure, may be an important risk factor for cardiovascular diseases by increasing methylated arginine levels.

Alteration of thiol disulfide homeostasis and ischemia-modified albumin levels as indicators of oxidative status in patients with silicosis.

The aim of this study was to evaluate the oxidative status in patients with silicosis by detecting dynamic thiol disulfide homeostasis (TDH), ischemia-modified albumin level (IMA) catalase (CAT) activity, and the correlation of these markers with pulmonary function tests. Male ceramic workers with silicosis (n = 91) and healthy individuals (n = 47) were recruited for the study. Radiographic abnormalities of pneumoconiosis were classified into three profusion categories (categories 1, 2, and 3), and patients with silicosis, those with category 1, were defined as group 1 and those with category 2 or 3 were defined as group 2. Plasma levels of native thiol (NT), total thiol (TT), disulfide (Ds), IMA, and CAT activities were determined. Pulmonary function tests of groups were compared. NT, TT, and NT/TT ratios were significantly lower in groups 1 and 2 than the control group (p < 0.05). These did not differ between patients with silicosis (groups 1 and 2) and control group (p = 0.421). Ds/NT and Ds/TT ratios were significantly higher in group 2 than the control group (p < 0.05). NT, TT, and Ds did not differ significantly between groups 1 and 2. The oxidant biomarker IMA was higher (p < 0.001), and the antioxidant parameters albumin and CAT were lower in groups 1 and 2 (p < 0.001) compared with the control group. The mean FEV1act, FVCact, forced expiratory volume in 1 second/forced vital capacity (%), and value of 25-75 percent maximum expiratory flow were significantly lower in groups 1 and 2 than control group. We have used a novel colorimetric method to assess TDH in patients with silicosis. Alteration of plasma thiol/disulfide homeostasis and IMA levels might be novel indicators of oxidative stress in silicosis.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Inflammatory Markers in Patients With Welders' Lung Disease.

OBJECTIVE: To investigate neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in patients with welders' lung disease (PWLD) and its relation with pulmonary function parameters. METHODS: One hundred sixteen male PWLD and 118 healthy non-exposed individuals were recruited. Pulmonary function tests (PFTs), complete blood count, erythrocyte sedimentation rate (SED), c-reactive protein (CRP), NLR and PLR of both groups were retrospectively analyzed. RESULTS: NLR, PLR, WBC, ESR, and CRP were significantly higher in PWLD compared to controls (all P < 0.001). All PFTs, except for FEV1/FVC, significantly decreased in PWLD compared to controls as. NLR correlated positively with ESR (r = 0.241 and P < 0.001). CONCLUSION: Our results show that NLR and PLR can be considered as new inflammatory markers in PWLD with their cheap, fast and easily measurable feature with routine blood count analysis.

Dynamic thiol/disulphide homeostasis as indicator of oxidative stress in automotive workers.

Purpose: To examine thiol-disulphide homeostasis auto painters.Materials and methods: A total of 115 male workers, including 60 auto painters workers and 55 reference group, of the painting and assembly line units respectively, were included in the study. Thiol-disulphide parameters and ischaemia-modified albumin (IMA) of groups were determined. Urinary hippuric acid, (HA) phenol, hexanedione, trichloroacetic acid, arsenic and blood lead and manganese were analysed.Results: The median urinary HA level was significantly higher in auto painters when compared to the reference group [(2461 (1212) vs. 520 (513) µgr/L), (p < 0.001)] . The mean disulphide level [19.7 (4.3) vs 0.15.1(4.1) µmol/L, (p < 0.001)], the disulphide/native thiol ratio [4.72 (1.47) vs. 3.13 (1.21, (p < 0.001)] and the disulphide/total thiol ratio [4.31 (1.23) vs. 2.94 (1.06), (p < 0.001)] were higher in auto painters when compared to the reference group. There was a statistically significant positive correlation between urinary HA and disulphide concentrations (r = 0.536 and p < 0.001), disulphide/native thiol ratio (r = 0.564 and p < 0.001) and the disulphide/total thiol ratio (r = 0.564 and p < 0.001) and IMA (r = 0.396 and p < 0.001).Conclusion: The results presented in this study showed that oxidative stress can be associated with occupational exposure to toluene denoted by alteration of thiol disulphide homeostasis and ischaemia-modified albumin levels.

Assessment of Endothelial Dysfunction with Methylated Arginines and L-arginine in Cadmium-Exposed People: a Pilot Study.

BACKGROUND: Workers can be exposed to cadmium (Cd) in various industries. On the other hand, another potential source for Cd exposure is the food chain and smoking. Environmental pollution to Cd plays an important role in the development of atherosclerosis. Asymmetric dimethyl arginine (ADMA) levels promote the development of endothelial dysfunction and atherosclerosis-related diseases such as hypertension, acute coronary syndrome, congestive heart failure, and peripheral vascular diseases. The aim of this study is to evaluate the cardiovascular risks of non-symptomatic cadmium-exposed workers and to promote the value of methylated arginines in screening of toxic exposures. METHODS: A total 176 participants were included in the study which has been separated as control group (n = 79) and Cd-exposed group (n = 94). Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for toxicological analysis of Cd levels. Also, liquid Chromatography-Mass Spectrometry (LC-MS/MS) was used for levels of methylated arginines such as ADMA, symmetric dimethylarginine (SDMA), NG-monomethyl-L-arginine (L-NM-MA), homoarginine, and citrulline. RESULTS: Statistically significant differences were observed for control and Cd-exposed groups, respectively as follows: Cd levels (0.25 ± 0.13 µg/L and 1.33 ± 0.61 µg/L), ADMA (0.16 ± 0.04 µmol/L and 0.22 ± 0.11 µmol/L), SDMA (0.21 ± 0.06 µmol/L and 0.27 ± 0.07 µmol/L), L-NMMA(0.02 ± 0.01 µmol/L and 0.03 ± 0.01µmol/L), and arginine/ADMA levels (695.82 ± 620.63 and 478.30 ± 432.61). CONCLUSIONS: Our results suggest that workers chronically exposed to Cd showed imbalances in endothelial parameters.

Changing levels of selenium and zinc in cadmium-exposed workers: probable association with the intensity of inflammation.

Inflammation is a response mediated by multiple cytokines, such as IL-6, IL-10 and TNF-α. Cadmium (Cd) has been involved in the etiopathogenesis of many diseases via inflammation. Selenium (Se) and zinc (Zn) play a pivotal role in maintaining many physiological functions of cells as well as inhibiting Cd-induced cytotoxicity. This study investigated the anti-inflammatory effects of Se and Zn in cadmium-exposed workers by measuring the levels of IL-6, IL-10 and TNF-α cytokines in 68 control and 91 Cd-exposed subjects. Blood samples were obtained from each participant for immunological, toxicological and routine analysis. All samples were digested by microwave oven and analysed by inductively coupled plasma mass spectrometry (ICP-MS). IL-6, IL-10 and TNF-α cytokine levels were found to be statistically different (p < 0.001) between the control and Cd-exposed groups (23.50 ± 7.70 pg/mL vs. 69.05 ± 19.06 pg/mL; 28.61 ± 9.83 pg/mL vs. 51.79 ± 11.77 pg/mL; 3.44 ± 1.14 pg/mL vs. 5.79 ± 1.04 pg/mL, respectively). High positive correlations were found between Cd levels of participants and IL-6, IL-10, TNF-α and CRP levels (r = 0.568, r = 0.615, r = 0.614 and r = 0.296, respectively, p < 0.01). In terms of the regression analysis results, there were significant effects of Cd on IL-6, IL-10 and TNF-α levels (p < 0.05). The Cd, Zn and Se levels between control and exposed group were significantly different [0.26 ± 0.15 µg/L vs. 3.36 ± 1.80 µg/L; 143.91 ± 71.13 µg/dL vs. 121.09 ± 59.88 µg/dL; 92.98 ± 17.03 µg/L vs. 82.72 ± 34.46 µg/L (p < 0.001, p < 0.03, p < 0.015), respectively]. In conclusion, increasing levels of Se and Zn decreases the intensity of inflammation as measured by IL-6, IL-10 and TNF-α levels.

Predictive risk factors for development of silicosis in Turkish ceramic workers.

INTRODUCTION: Silicosis is still one of the the most common occupational disease in the world. The ceramic industry is one of the main sectors where silicosis patients are increasingly reported. The aim of this study was to evaluate the differences in demographic characteristics, radiological findings and pulmonary function test results of the ceramic workers with silicosis and those did not develop the disease. MATERIALS AND METHODS: A total of 626 workers, 459 with silicosis and 167 without silicosis, working in the ceramics industry those admitted to Ankara Occupational and Environmental Diseases Hospital between 2009 and 2018 were included in the study. The cases were evaluated retrospectively. RESULT: The median age and duration of work of the workers with silicosis were significantly higher (p< 0.001) compared to workers without silicosis. The risk of silicosis was found to be 22.5 times higher in 50 years or older age. Working 11-20 years and more than 20 years increased the risk of silicosis by 3.1 fold and 3.9 fold respectively. Smoking more than 10 package-years was found to increase the risk of silicosis 2 fold. The workers who had worked in clay processing, sanding, glazing or smelting were found to have 5.2-fold, 3.8-fold 2.5 and 2.4 fold higher silicosis risk, respectively. CONCLUSIONS: In this study, it has been shown that older age, longer duration of work, smoking, working in clay processing, sanding, glazing or smelting sections increase the risk of silicosis in ceramic workers.

Radiological progression and lung function decrements among silica-exposed ceramic workers: a longitudinal study.

Objectives: This follow-up study set out to evaluate the natural course and radiographic progression of silicosis among ceramic workers and describe the risk factors related with disease progression. Materials and methods: We retrospectively analyzed the data of ceramic workers with silicosis who were referred to our hospital between February 2010 and March 2018. A total of 165 ceramic workers followed at least 24 months and with at least two chest radiographs were included in the study. Results: The duration of silica exposure ranged from 5.5 to 27 (median 13.6) years. The numbers of patients according to follow-up time were as follows: 38 (2-2.9) years, 77 (3-3.9) years, 26 (4-4.9) years, 17 (5-5.9) years, and 7 (≥6) years. Overall 62 of 165 (37.5%) cases showed radiologic evidences of progression ranging from 2 to 8.9 years (mean 3.7 years). Pulmonary function loss rate among silicosis patients was 36.9% (61/165). Multiple logistic regression analysis showed a significant relation between radiographic progression and age (OR, 1.079: 95% CI, 1.011-1.152), follow-up time (OR, 1.557: 95% CI, 1.144-2.118), and the ILO category (category 2 or 3) at first visit (OR, 3.507: 95% CI, 1.505-8.170). Conclusions: Our findings suggest that one-third of Turkish ceramic workers with silicosis who were followed up to 8.9 years showed progression that was related to increasing age greater ILO category at time of initial visit and follow-up duration.

The effects of occupational lead exposure on selected inflammatory biomarkers.

In exposure to toxic metals such as lead, determining lead and cytokine levels (IL-6, IL-10, and TNF-α) is essential for early detection of diseases. The aim of this study was to develop an model for early detection of inflammation and onset of atherosclerosis in the absence of clinical findings in young workers, which could help physicians take timely an action and start treatment. This study included 49 metal workers exposed to lead occupationally and 50 unexposed administrative workers (controls) who underwent immunological analysis for cytokines (IL-6, IL-10, and TNF-α) and atherosclerosis markers (h-FABP and VCAM-1), toxicological analysis for lead, and routine biochemical analysis (ALT, AST, creatinine) at the Ankara Occupational and Environmental Diseases Hospital in 2017. Lead levels correlated with IL-6, IL-10, and TNF-α (r=0.469, r=0.521 and r=0.279, respectively, p<0.01) but did not significantly affect h-FABP and VCAM-1 levels.

Arsenic-induced inflammation in workers.

Occupational and environmental exposures to metal and metalloids can result in neurotoxicity and immunotoxicity. Selenium (Se) is essential for the proper functioning of neutrophils, macrophages, natural killer (NK) cells, T-lymphocytes and other immune mechanisms, while zinc (Zn) is a trace element essential for basic cell activities, including cell growth and differentiation. Arsenic (As) may lead to different types of immunosuppressive effects. This study consisted of 62 male workers, who had been exposed to arsenic for different durations and 73 non-exposed male workers (control group) with no history of occupational toxic metal exposure. Whole blood and serum samples were taken from each participant for immunological, toxicological and routine analysis during their annual periodical examination. Arsenic, selenium and zinc levels were determined by the ICP-MS and cytokines, IL-6, IL-10, TNF-α, sE-selectin and VCAM-1, were measured by ELISA. There were statistically significant differences (p < 0.001) between control and As-exposed group in As (1.37 ± 0.42 vs. 4.27 ± 1.54 µg/L) and Se levels (106.37 ± 48.04 vs. 74.70 ± 30.45 µg/L). The changing levels of As, Zn and Se seems to affect the severity of inflammatory reactions based on IL-6, IL-10 and TNF-α levels (r = 0.755, r = 0.679 and r = 0.617, respectively, for all p < 0.01). Selenium was found to have a suppressive effect on cytokines, as evidenced by Pearson correlations and regression analysis. These findings support the need to closely monitor Se levels in individuals exposed to arsenic and benefits for Se supplementation in the case of arsenic exposure, occupationally or environmentally.

Serum endocan level and diastolic functions in the case of lead exposure

Background/aim: Lead can cause morphological and functional changes in heart, and inflammation and endothelial dysfunction in vasculature. Endocan, as a novel indicator of endothelial dysfunction, has been used for cardiovascular diseases. This study investigated the relationship between lead exposure, endocan levels, and diastolic functions. Materials and methods: A total of 51 lead-exposed workers without a known cardiovascular disease or risk factors and 54 healthy controls were enrolled. All participants underwent transthoracic echocardiography. Blood lead and serum endocan levels were analyzed. Results: Baseline demographic and clinical characteristics were found to be similar between groups. Median blood lead (32 vs 1.5 µg/dL, P < 0.001) and serum endocan levels (67 vs 57.1 pg/mL, P = 0.02) were significantly higher in the lead-exposed group. Serum endocan level showed a positive correlation with blood lead levels (r = 0.404, P = 0.003) in lead-exposed workers. Serum endocan level was an independent risk factor for increased E/E' ratio (ß = 0.704, P = 0.002) and left atrial volume index (ß = 1.158, P = 0.011) and higher level of lead in blood was an independent risk factor for increased E wave (ß = 8.004, P = 0.022) in lead-exposed workers. Conclusion: Worsened diastolic functions may be seen in the course of lead exposure. Due to sharing a similar mechanism, a higher serum level of endocan may be a valuable laboratory clue for impaired diastolic function in this population.

Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio as haematological indices of inflammatory response in ceramic workers' silicosis.

INTRODUCTION: Occupational exposure to crystalline silica over time may result in silicosis: a fatal, irreversible occupational disease leading to lung function impairment. A complex inflammatory process, excessive accumulation of mesenchymal cells and collagen production are the primary mechanisms underlying silicosis. Neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) have emerged as representative indices of systemic inflammation. OBJECTIVES: The purpose of the present study was to investigate the relationship between NLR, PLR and silicosis. METHODS: We retrospectively analysed the demographic and laboratory data of ceramic workers who were referred to our Hospital between 2010 and 2018. Five hundred and seventy-three patients with silicosis and 222 ceramic workers without silicosis (controls) were included in the study. RESULTS: The radiographic ILO classification of silicosis patients was as follows: category 1 (71.5%), category 2 (19.2%), category 3 (7.5%). NLR and PLR in categories 2 and 3 were significantly higher when compared with the control group (P < .005). FEV1 , FEV1 %, FVC, FVC % and PEF were significantly lower in all silicosis patients and also in patients with subcategories (all P < .005). NLR showed a poor positive correlation with CRP (r = 0.095, P < .05) and ESR (r = 0.207, P = .000) while PLR only with ESR (r = 0.317, P = .000) in patients with silicosis. NLR and PLR showed negative correlations with FEV1 , FVC and PEF (all P < .005). CONCLUSION: We conclude that NLR and PLR have significant but poor correlations with pulmonary functions and severity of silicosis, especially in late radiographic profusion categories.

Fixed drug eruption due To 2,3-dimercapto-1-propanesulfonic acid (DMPS) treatment for mercury poisoning: a rare adverse effect.

BACKGROUND: Fixed drug eruptions (FDE) are characterized by recurrent, usually solitary erythematous or dark red macular, plaque or bullous lesions, all at the same site. Among the first choices for antidotal treatment in mercury exposure, 2,3-dimercapto-1-propanesulfonic acid (DMPS) is generally a drug with a low incidence of side effects. FDE due to DMPS was not detected in our literature research and so we aimed to present this rare case. CASE REPORT: Forty-eight-year-old male patient, gunpowder and explosives factory worker, was admitted to our hospital because of mercury exposure and we started DMPS treatment. On the second day of chelation treatment, swelling and felting on lips and complaints of wound formation in genital areas started. Annular, purple color plaque on penis with no angioedema was observed. Case was regarded as FDE. Systemic and topical steroid therapy was started after termination of chelation therapy and lesions regressed with steroids. DISCUSSION: Drug eruptions are substantially common dermatological problems and can be seen in about 2.2% of inpatients. The most common unexpected effects of DMPS are allergic skin reactions. The clinical state regress rapidly after the cessation of chelation therapy.

A new potential biomarker in early diagnosis of firefighter lung function impairment: dynamic thiol/disulphide homeostasis.

OBJECTIVES: The aim of this study was to investigate the associations between urinary arsenic, oxidative stress, assessed by thiol/disulphide homeostasis, and lung diseases in firefighters. METHODS: The study conducted among the municipality-based male firefighters (n = 100) who were admitted to occupational diseases clinic for periodic medical examination. The control group consisted of non-exposed male office workers (n = 50). Urinary arsenic levels, thiol/disulphide homeostasis parameters of participants were determined. Also, lung diseases were assessed by chest X-ray and pulmonary function tests. RESULTS: The mean age and work year did not differ in the study and control group. The median urinary arsenic concentration of firefighters was significantly higher than in the control group: 15.65 (2.5-246) µg/L and 3 (0.10-6) µg/L, respectively (p < 0.001). The parameters of pulmonary function tests (PFT) FVC (%), FEV1 (%), FEV1/FVC ratio and FEF 25-75 (%) were all significantly lower in firefighters compared to controls. A significant increase in mean serum disulphide concentration (17.10 ± 8.31 µmol/L vs. 7.48 ± 5.91) (Fig. 1) and disulphide/native thiol % ratio: 3.63 (0.53-11.43) vs. 1.51 (0.03-7.65) (p < 0.001) were found between exposed group and controls. The Spearman's correlation analysis revealed a positive correlation between urinary arsenic and disulphide (r = 0.422, p < 0.001), disulphide/native thiol % ratio (r = 0.409, p < 0.001). Nevertheless, urinary arsenic correlated negatively with all PFT parameters including FVC (%), FEV1 (%), FEV1/FVC and FEF 25-75 (%) (p < 0.001). CONCLUSION: We showed the arsenic-induced oxidative stress in firefighters with impairments of several lung functions determined by thiol/disulphide homeostasis using a novel method.

Occupational exposure to asphalt fume can cause oxidative DNA damage among road paving workers.

OBJECTIVES: We designed the present study to determine the effect of occupational exposure to asphalt fumes on oxidative status and DNA damage in road paving workers. METHODS: Sixty road paving workers exposed to asphalt fumes and forty non-exposed control subjects were recruited. Occupational exposure to PAHs was assessed by urinary 1-hydroxypyrene (1-OHP) excretion. Serum thiol disulfide homeostasis (TDH), total oxidant status (TOS) and total antioxidant status (TAS) and urinary 8-hydro-deoxyguanosine (8-OH-dG) level were evaluated by automated colourimetric method. RESULTS: The urinary concentrations of 1-OHP and 8-OH-dG were significantly higher in the exposed group than in the control group (P < 0.001). Disulfide/thiol ratio, TOS, and TAS were also significantly higher for the asphalt workers. A positive correlation existed between urinary 1-OHP and 8-OH-dG, TOS and TAS. CONCLUSION: Study results indicate that exposure to PAHs induces oxidative stress and causes genotoxic effects in asphalt workers.

Alteration of thiol-disulfide homeostasis in workers occupationally exposed to arsenic.

This study evaluates the redox state in occupationally arsenic-exposed workers (n = 71) by assessing the dynamic serum thiol-disulfide homeostasis. We determined the serum thiol-disulfide homeostasis parameters of exposed workers and controls (n = 43) using a novel automated colorimetric assay. Median urinary As and 8-isoprostane levels of exposed group were significantly higher than control group (16.40 µg/L vs 2µg/L, p < .001 and 2.28 ng/ml vs 0.54 ng/ml, p < .001, respectively). Disulfide level, disulfide/native thiol ratio, and disulfide/total thiol ratio were significantly higher in exposed group. The mean ceruloplasmine and myeloperoxidase activities of As-exposed group were significantly higher than control group (117.15 U/L vs 87.02 U/L, p = .035 and 148.53 U/L vs 97.75 U/L, p = .000, respectively). The median catalase activity did not differ in the two groups. Our findings revealed that As disrupts the thiol-disulfide homeostasis in favor of disulfide.

Evaluation of the ambulatory arterial stiffness index in lead-exposed workers.

OBJECTIVE: Lead exposure has been associated with various cardiovascular disorders. It may also cause increased inflammation and fibrosis in the arterial system resulting in an increase in arterial stiffness. In this study, the ambulatory arterial stiffness index (AASI), which is a technique that measures arterial stiffness, was evaluated in occupationally lead-exposed workers. METHODS: In this cross-sectional study, 68 lead-exposed workers without known cardiovascular risk factors and 68 healthy subjects were evaluated according to the 24-hour ambulatory blood pressure monitorization (ABPM) profiles and blood and 24-hour urine lead levels. A regression slope of diastolic over systolic blood pressure (BP) was computed in each participant. AASI was defined as 1 minus the regression slope. RESULTS: There were no significant differences in terms of baseline demographic, clinical, echocardiographic characteristics, and ABPM profiles between the groups. In lead-exposed workers, the mean age was 34.7±8.1 years, and the median blood and urine lead levels were 40.5 µg/dL and 34.9 µg/L, respectively. AASI was 0.42±0.10 in lead-exposed workers and 0.37±0.10 in control subjects (p=0.007). In correlation analysis, AASI was correlated with both blood (r=0.417, p<0.001) and urine lead (r=0.242, p=0.047) levels. In regression analysis, blood lead level was found to be associated with AASI (ß=0.086, p<0.001). CONCLUSION: AASI, which is an indicator of arterial stiffness, was found to be higher in lead-exposed workers than in healthy individuals. Increased AASI may be considered an early sign of arterial involvement in case of lead exposure.