Thiol/disulfide homeostasis in asphalt workers

Investigating industrial PAH air pollution in relation to population exposure in major countries: A scoring approach

Polycyclic aromatic hydrocarbons (PAHs) are common air pollutants worldwide, associated with industrial processes. In the general population, both modeling and field studies revealed a positive correlation between air PAH concentrations and urinary PAH metabolite levels. Many countries lack population urinary data that correspond to local PAH air concentrations. Thus, we proposed a scoring-based approximate approach to investigating that correlation in selected countries, hypothesizing that PAH air concentrations in selected regions could represent the national air quality influenced by industrial emission and further correlate to PAH internal exposure in the general population. This research compiled 85 peer-reviewed journal articles and 9 official monitoring datasets/reports covering 34 countries, 16 of which with both atmospheric PAH data and human biomonitoring data. For the air pollution score (AirS), Egypt had the highest AirS at 0.94 and Pakistan was at the bottom of the score ranking at -1.95, as well as the median in the UK (AirS: 0.50). For the population exposure score (ExpS), China gained the top ExpS at 0.44 and Spain was with the lowest ExpS of -1.52, with the median value in Italy (ExpS: 0.43). Through the correlation analysis, atmospheric PAHs and their corresponding urinary metabolites provided a positive relationship to a diverse extent, indicating that the related urinary metabolites could reflect the population's exposure to specific atmospheric PAHs. The findings also revealed that in the 16 selected countries, AirS indexes were positively correlated with ExpS indexes, implying that higher PAH levels in the air may lead to elevated metabolite urinary levels in general populations. Furthermore, lowering PAH air concentrations could reduce population internal PAH exposure, implying that strict PAH air regulation or emission would reduce health risks for general populations. Notably, this study was an ideal theoretical research based on proposed assumptions to some extent. Further research should focus on understanding exposure pathways, protecting vulnerable populations, and improving the PAH database to optimize PAH pollution control.

Analysis of thiol/disulphide homeostasis and oxidant-antioxidant status as a result of exposure to radio-frequency electromagnetic fields

The aim of the current study is to investigate the effect of daily long-term radio-frequency electromagnetic field (RF-EMFs) exposure on thiol/disulphide homeostasis and oxidant-antioxidant status in the serum of rats. Fourteen male Sprague Dawley rats were divided into two equal groups (n = 7). They were grouped as group 1 (sham-control) and group 2 (2100 MHz exposed). Group 2 rats were exposed to GSM-like signals for 5 h/day, 7 days per week for 14 days. In serum of blood samples, the native, total and native/total thiol levels and antioxidant-oxidant parameters were analyzed. The study revealed that the mean serum total thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,219); the mean serum native thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,416), and the mean serum disulphide levels of GSM exposure group was rather higher than sham-control group (p = 0,566). On the other hand, the mean serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) of GSM exposure group were higher than sham-control group. There are no data in the literature, that examine the effects of RF-EMFs on thiol/disulphide homeostasis. The results of this study, indicate that RF-EMFs did not cause oxidative stress and statistically changes in thiol/disulphide homeostasis. More sample sizes and longer-term exposures are needed to confirm the results of this study.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

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.

The change in serum Thiol/Disulphide homeostasis after transrectal ultrasound guided prostate biopsy

Objectives

The aim of this prospective clinical study was to investigate variations in a novel oxidative stress marker (thiol/disulphide homeostasis) in men who underwent transrectal ultrasound guided prostate biopsy (TRUSB).

Materials and Methods

A total of 22 men undergoing TRUSB of the prostate were enrolled in the study. Patients with abnormal digital rectal examination and/or total prostate specific antigen (PSA) over 4ng/mL underwent TRUSB with 12 cores. Serum samples were obtained before and just after the procedure to evaluate the possible changes in thiol/disulphide homeostasis. Mean age, total PSA and free PSA, prostate volume and histopathological data were also recorded.

Results

Mean age of the study population was 65.05±8.89 years. Significant decreases in native and total thiol levels were documented after the biopsy procedure. However, serum disulphide levels and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios did not significantly change after TRUSB. No correlation was observed between oxidative parameters and total PSA and free PSA levels, prostate volume and histopathology of the prostate. However, mean patient age was significantly correlated with mean native and total thiol levels.

Conclusion

Significant decreases in serum native and total thiol levels related to the prostate biopsy procedure suggest that TRUSB causes acute oxidative stress in the human body. Since our trial is the first in the current literature to investigate these oxidative stress markers in urology practice, additional studies are warranted.

A novel method for determining the relation between nasal polyposis and oxidative stress: the thiol/disulphide homeostasis

CONCLUSION

It is thought that oxidative stress may be the major cause of the increase in the oxide thiol form in the study group. The relationship between oxidative stress status and dynamic thiol/disulphide in nasal polyposis now needs to be investigated.

OBJECTIVES

The purpose of this study was to evaluate the relation between nasal polyposis and thiol/disulphide homeostasis, used as a marker of oxidative stress, by measuring that exchange using a novel technique.

MATERIALS AND METHODS

The study group consisted of 40 patients (mean age = 46.75 ± 13.92 years) with bilateral nasal polyposis patients admitted to the hospital. The control group consisted of 31 (mean age = 43.20 ± 5.68 years) age, sex, and body mass index matched healthy subjects. Thiol/disulphide homeostasis concentrations were measured using a newly-developed method (Erel & Neselioglu).

RESULTS

Native thiol and total thiol levels were lower in the study group compared to the control group (native thiol = 415.8 ± 69.1 μmol/L vs 448.7 ± 37.5 μmol/L, p < 0.05; total thiol = 449.02 ± 72.0 μmol/L vs 477.28 ± 44.5 μmol/L, p < 0.05, respectively). Disulphide level and the disulphide/native thiol and disulphide/total thiol ratios were higher in the study group compared to the control group (disulphide = 16.58 ± 5.04 μmol/L vs 14.28 ± 5.3 μmol/L, p < 0.05; disulphide/native thiol ratio = 4.07 ± 1.52% vs 3.14 ± 1.04%, p < 0.05, disulphide/total thiol ratio = 3.73 ± 1.23% vs 2.94 ± 0.92%, p < 0.05, respectively).