Co-administration of toluene and xylene antagonized the testicular toxicity but not the hematopoietic toxicity caused by ethylene glycol monoethyl ether in Sprague-Dawley rats

Urinary Volatiles and Chemical Characterisation for the Non-Invasive Detection of Prostate and Bladder Cancers

Bladder cancer (BCa) and prostate cancer (PCa) are some of the most common cancers in the world. In both BCa and PCa, the diagnosis is often confirmed with an invasive technique that carries a risk to the patient. Consequently, a non-invasive diagnostic approach would be medically desirable and beneficial to the patient. The use of volatile organic compounds (VOCs) for disease diagnosis, including cancer, is a promising research area that could support the diagnosis process. In this study, we investigated the urinary VOC profiles in BCa, PCa patients and non-cancerous controls by using gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) to analyse patient samples. GC-IMS separated BCa from PCa (area under the curve: AUC: 0.97 (0.93-1.00)), BCa vs. non-cancerous (AUC: 0.95 (0.90-0.99)) and PCa vs. non-cancerous (AUC: 0.89 (0.83-0.94)) whereas GC-TOF-MS differentiated BCa from PCa (AUC: 0.84 (0.73-0.93)), BCa vs. non-cancerous (AUC: 0.81 (0.70-0.90)) and PCa vs. non-cancerous (AUC: 0.94 (0.90-0.97)). According to our study, a total of 34 biomarkers were found using GC-TOF-MS data, of which 13 VOCs were associated with BCa, seven were associated with PCa, and 14 VOCs were found in the comparison of BCa and PCa.

Non-Invasive Detection and Staging of Colorectal Cancer Using a Portable Electronic Nose

Electronic noses (e-nose) offer potential for the detection of cancer in its early stages. The ability to analyse samples in real time, at a low cost, applying easy-to-use and portable equipment, gives e-noses advantages over other technologies, such as Gas Chromatography-Mass Spectrometry (GC-MS). For diseases such as cancer with a high mortality, a technology that can provide fast results for use in routine clinical applications is important. Colorectal cancer (CRC) is among the highest occurring cancers and has high mortality rates, if diagnosed late. In our study, we investigated the use of portable electronic nose (PEN3), with further analysis using GC-TOF-MS, for the analysis of gases and volatile organic compounds (VOCs) to profile the urinary metabolome of colorectal cancer. We also compared the different cancer stages with non-cancers using the PEN3 and GC-TOF-MS. Results obtained from PEN3, and GC-TOF-MS demonstrated high accuracy for the separation of CRC and non-cancer. PEN3 separated CRC from non-cancerous group with 0.81 AUC (Area Under the Curve). We used data from GC-TOF-MS to obtain a VOC profile for CRC, which identified 23 potential biomarker VOCs for CRC. Thus, the PEN3 and GC-TOF-MS were found to successfully separate the cancer group from the non-cancer group.

Nicotinamide Mononucleotide Restores the Meiotic Competency of Porcine Oocytes Exposed to Ethylene Glycol Butyl Ether

Ethylene glycol butyl ether (EGBE), a type of glycol ethers, is a common chemical used in both industrial and household products. Increasing animal studies have indicated that it produces reproductive problems, such as testicular damage, reduced female fertility, death of embryos, and birth defects. However, how it influences the female germ cells has not yet determined. Here, we found that EGBE exposure resulted in the defective porcine oocyte maturation via disruption of cytoskeleton dynamics, showing the abnormal spindle assembly, chromosome alignment, and actin organization. Meanwhile, EGBE exposure perturbed the mitochondrial distribution and function, leading to the accumulation of reactive oxygen species (ROS) and generation of DNA damage and apoptosis. Of note, nicotinamide mononucleotide (NMN) supplementation rescued the meiotic defects caused by EGBE exposure via restoring NAD⁺ level and mitochondrial function and thus eliminating the excessive ROS. Taken together, our observations illustrate that NMN supplementation is an effective strategy to protect oocyte quality against environmental pollutant-induced deterioration, contributing to improve the animal and human fertility.

Induction of oxidative damage in the testes and spermatozoa and hematotoxicity in rats exposed to multiple doses of ethylene glycol monoethyl ether

The effects of ethylene glycol monoethyl ether (EGEE) on the antioxidant systems of the testes and epididymal spermatozoa were investigated in rats at dose levels of 0, 100, 200 and 400 mg kg-1 body weight (bw) administered orally by gavage for 14 consecutive days. The bw gain of the EGEE-treated rats decreased significantly at 200 and 400 mg kg- 1 bw compared with the control group. There were no significant changes in the weights of the testes, epididymis, seminal vesicles and prostate glands of the EGEE-treated rats. In the testes, while EGEE treatment resulted in significant decrease in glutathione (GSH) level, superoxide dismutase (SOD) and catalase (CAT) activities, it markedly increased the malondialdehyde (MDA) level, glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) activities at 200 and 400 mg kg-1 dose levels but vitamin C content remained unaffected in all the groups. In the spermatozoa, administration of EGEE caused significant decrease in the activities of CAT, GST and LDH as well as in the levels of vitamin C and GSH but significantly increased the MDA level and SOD activity compared with the control rats. Histopathological examination showed severe degeneration of the testes, such as generalized erosion and necrosis of the germinal epithelium of the testes, but mildly affected the epididymis at 400 mg kg-1 dose only. Data on spermatozoa analysis of EGEE-treated rats revealed significant decrease in the epididymal spermatozoa number, testicular spermatozoa number, daily spermatozoa production and spermatozoa motility but significantly increased the total spermatozoa abnormalities without affecting the spermatozoa live-dead ratio at all dose levels when compared with the control group. Results of haematological examination showed that white blood cells (WBC), platelets neutrophils and mean corpuscular haemoglobin concentration (MCHC) were significantly lower whereas lymphocytes were increased in 200 and 400 mg/kg EGEE-exposed rats than in the controls. EGEE at 100 mg/kg bw produced minor effect on haematological parameters but adversely affected testes and spermatozoa. In summary, short term administration of EGEE is hematotoxic and gonadotoxic and its effects on male reproduction could be due to the induction of oxidative stress in testes and spermatozoa.

Hematological Follow‐up of an Intervention Program Adding Rubber Glove‐Wearing to Local Ventilation for 2‐Ethoxyethanol Acetate‐Exposed Workers

The objective of this study was to evaluate an intervention program, implemented in year 1999, of wearing rubber gloves in addition to engineering control, and to follow-up the hematological effects of 2-ethoxyethanol acetate (2-EEA) exposure among workers in a silk-screening factory. All workers from the printing department with direct exposure to 2-EEA were recruited as the exposed group. Workers from the other departments were recruited as the comparison group. Hematological parameters were measured during health surveys conducted 3 times every two years. Information on personal characteristics and working habits was obtained through a structured questionnaire. More female workers were involved in manual printing resulting in higher exposure to 2-EEA. Hemoglobin and haematocrit levels in female exposed workers were significantly lower than those of female comparison workers in the 1st (1998) health survey, but not in the 2nd (2000) and 3rd (2002) health surveys. No difference was found between male exposed and comparison workers for all three surveys. Longitudinal analysis after adjusting for confounders using the general estimating equation model showed the hemoglobin, haematocrit, and RBC count were significantly higher for 2-EEA exposed workers than comparison workers across the 3 surveys (n=42). The results show that wearing rubber gloves in addition to local ventilation was effective at preventing direct dermal exposure to 2-EEA and ameliorated the hematological effects of 2-EEA exposure.

Fertility and exposure to solvents among families in the Agricultural Health Study

BACKGROUND

Several studies have reported associations between solvent exposure and reduced female fertility, but the evidence is inconclusive for male fertility.

OBJECTIVES

To investigate the impact of solvent exposure on subfertility among families of male licensed pesticide applicators in the Agricultural Health Study cohort.

METHODS

The couples enrolled between 1993 and 1997. Cross-sectional questionnaire information on work tasks was used to assess exposure to solvents. The data were limited to couples (wife aged less than 40 years) with an attempt at pregnancy in the last four years (n = 2112).

RESULTS

Twenty eight per cent of the couples were defined as subfertile (not conceiving a pregnancy after at least 12 months of unprotected intercourse, regardless of whether or not a pregnancy ultimately occurred). Adjusted subfertility odds ratios (OR) for exposure to solvents were calculated with logistic regression. Female (OR 1.42, 95% CI 1.15 to 1.75) and male exposure to solvents (OR 1.21 (95% CI 0.93 to 1.57) for monthly exposure and 1.40 (95% CI 0.97 to 2.03) for daily or weekly exposure) were associated with subfertility. In farming, spouses may share or exchange jobs. To account for potential dual exposure, variables for parental exposure (either parent exposed or both parents exposed) were also defined. Both were strongly associated with subfertility (OR 1.62 (95% CI 1.20 to 2.17) and OR 2.10 (95% CI 1.22 to 3.60), respectively).

CONCLUSIONS

Solvents may impair fertility of either gender, though the evidence for female effects is stronger than for male effects.

Inhibition of cyclooxygenase activity, platelet aggregation and thromboxane B2 production by two environmental toxicants: m- and o-cresol

Cresol is a well-known environmental pollutant, toluene metabolite, uremic toxicant and accidental poisoning product. Formocresol, a preparation of formalin and cresol, is also used as a root canal medicament and for pulpotomy of primary teeth. However, little is known about its effect on cardiovascular system. In this study, m-cresol inhibited the AA-induced platelet aggregation by 43-97% at concentrations ranging from 0.25 to 1 mM. Collagen-induced platelet aggregation was also inhibited by 0.25-1 mM of m-cresol by 47-98%. Accordingly, o-cresol (0.1-0.5 mM) also inhibited the AA-induced platelet aggregation by 46-96% and the collagen-induced platelet aggregation by 35-88% at concentrations of 0.1-1 mM. AA- and collagen-induced platelet thromboxane B(2) (TXB(2)) production was inhibited by even 0.1 mM of m-cresol with 88 and 54% of inhibition, respectively. The o-cresol (0.1 mM) also inhibited the AA- and collagen-induced platelet TXB(2) production with 91 and 97% respectively. Although m- and o-cresol (<1 mM) showed little effect on thrombin-induced platelet aggregation, they effectively inhibited the thrombin-induced platelet TXB(2) production. The m-cresol (2 and 5 mM) inhibited the COX-1 activity by 55-99%, but showed little effect on COX-2 enzyme activity. Moreover, o-cresol (0.5 and 1 mM) inhibited the COX-1 activity by 40-95%. COX-2 enzyme activity was inhibited by 68% at a concentration of 5 mM o-cresol. These results indicate that acute cresol-poisoning, direct root canal medication with formocresol or long-term occupational exposure to cresol and toluene may potentially suppress blood clot formation and lead to tissue hemorrhage via inhibition of platelet aggregation, TXB(2) production and COX enzyme activity.

Haematological effects among silk screening workers exposed to 2-ethoxy ethyl acetate

BACKGROUND

2-Ethoxy ethyl acetate (2-EEA) is a solvent with broad industrial and commercial applications. It has been reported to cause hematological toxicity, infertility, and teratogenesis.

AIMS

To investigate the haematological effects in 2-EEA exposed workers.

METHODS

Workers from one silk screening shop (n = 29), using 2-EEA as the major cleaning and printing solvent, were recruited as a high exposure group. Workers with indirect and non-exposure to 2-EEA (n = 56) were recruited as the comparison group. Venous blood was collected for blood routine examination. Air concentration of 2-EEA in this plant was measured by eight hour personal sampling.

RESULTS

The geometric mean (GM) of air concentration of 2-EEA in the high exposure group was 7.41 ppm (range 1.35-16.5 pppm). The mean exposure of female workers (GM = 9.34 ppm) was significantly higher than that of male workers (GM = 4.87 ppm). The GM of air 2-EEA concentration in the comparison group was 0.07 ppm (range: non-detectable to 3.62 ppm, n = 26). The haemoglobin and haematocrit in the female high 2-EEA exposure workers were significantly lower than those of female workers in the comparison group. No difference was found between male 2-EEA high exposure and comparison group workers. The haemoglobin, haematocrit, and RBC count in the study population had a significant dose-response relation with air 2-EEA levels.

CONCLUSION

Results suggest that 2-EEA is a haematological toxicant, which leads to anaemic status in high exposure female workers.

Flow cytometric assessment of ethylene glycol monoethyl ether on spermatogenesis in rats

The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in rats were investigated by a flow cytometric method. Rats were administered by gavage with EGEE at the various doses of 0 (saline alone), 100, 200, 400, and 800 mg/kg body weight/day for 4 weeks. The treatment of EGEE caused decreases in the weight of testis and epididymis and in the number of testicular cells. Histopathologically, exfoliation of germ cells into the tubular lumen was observed at the doses of above 200 mg/kg. The treatment of EGEE at the dose of 400 mg/kg caused moderate testicular degeneration. A significant depletion of haploid cells and a disproportionate ratio of diploid and tetraploid cells were observed as determined by flow cytometric analysis. These results indicate that the toxic effect of EGEE on the male reproductive system may be strongly associated with the disproportion of testicular germ cells.

Effects of long-term solvent exposure on blood cytokine levels and antioxidant enzyme activities in house painters

The aim of this study was to examine solvent-associated effects on blood cytokine levels, antioxidant enzyme activities, and malondialdehyde (MDA) concentration in house painters. Trace element (Cu and Zn) and nitrite and nitrate levels as well as protein concentrations in erythrocytes and serum were determined. Thirty male house painters and 30 male clerical workers were included in the study. There were 13 smokers and 17 nonsmokers in each group. Hemoglobin concentrations were significantly lower in house-painter blood compared to controls. House painters had significantly higher concentrations of erythrocyte protein (excluding hemoglobin), whereas no significant difference was observed between serum protein levels. Proinflammatory cytokine levels, such as tumor necrosis factor-alpha and interleukin-8, were significantly increased in house painters' sera. Interleukin-6 was below the detection limit of the assay in both groups. Interleukin-1beta and cytokine receptor interleukin 2R concentrations were not significantly affected. Furthermore, a three- to fourfold increase in nitrite and nitrate concentrations was found in house painters' sera. Serum superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities were significantly lower in house painters compared to controls. Malondialdehyde (MDA) concentration, a measure of lipid peroxidation, was found to be significantly elevated. In house painters, erythrocyte carbonic anhydrase and catalase activities were elevated approximately 11- fold and 2-fold, respectively. Zinc levels were significantly decreased in house painters' sera. Smoking was not found to be a major confounder for the association between solvent exposure and blood parameters.