Chromosomal damage in peripheral blood lymphocytes from nurses occupationally exposed to chemicals

Purebred dogs show higher levels of genomic damage compared to mixed breed dogs

Inbreeding is a common phenomenon in small, fragmented or isolated populations, typical conditions of many threatened species. In the present paper, we used a new non-invasive approach based on the buccal micronucleus assay to evaluate the possible relationships between inbreeding and genomic damage using the dog as model species. In particular, we assessed the frequencies of micronuclei and other nuclear aberrations in a group of purebred dogs (n = 77), comparing the obtained data with those from a control group represented by mixed breed dogs (n = 75). We found a significant increase of micronuclei, nuclear buds and total nuclear aberrations frequencies in purebred dogs compared to mixed-bred dogs. The absence of significant differences in the frequency of micronuclei and other nuclear aberrations amongst different breeds reinforces the hypothesis that the observed increased genomic damage amongst purebred dogs may not be due to a different genomic instability typical of a particular breed, but to inbreeding itself. This hypothesis is further confirmed by the fact that other endogen confounding factors, such as sex, age and weight, do not contribute significantly to the increase of genomic damage observed amongst purebred dogs. In conclusion, results presented in this study showed that, in purebred dogs, inbreeding may increase the levels of genomic damage. Considering that genomic damage is associated with increased physiological problems affecting animal health, the results we obtained may represent a stimulus to discourage the use of intensive inbreeding practices in captive populations and to reduce the fragmentation of wild populations.

The meta-analysis of sister chromatid exchange as a biomarker in healthcare workers with occupational exposure to antineoplastic drugs

BACKGROUND

Sister chromatid exchange (SCE) can be used to identify early occupational health status in health care workers. Our aim is to comprehensively assess the relationship between long-term exposure to antineoplastic drugs (ADs) and SCE in health care workers via meta-analysis.

METHODS

Five databases were systematically searched for relevant articles published from inception to November 30, 2022. Literature data are expressed as mean difference and 95% confidence intervals (CI) or relative risk and 95% CI. For I2 > 50% trials, random effect model is used for statistical analysis, otherwise fixed effect model is used. This review was registered in the International Prospective Register of Systematic Reviews (identifier CRD42023399914).

RESULTS

Fourteen studies were included in this study. Results showed the level of SCE in healthcare workers exposed to ADs was significantly higher than in controls. The mean difference of the SCE trial was 0.53 (95% CI: 0.10-0.95, P = .01) under a random-effects model.

CONCLUSIONS

The findings suggested a significant correlation between occupational exposure to ADs in health care workers and SCE, requiring the attention of health care workers in general.

Regular Sport Activity Is Able to Reduce the Level of Genomic Damage

Regular physical activity is considered one of the most valid tools capable of reducing the risk of onset of many diseases in humans. However, it is known that intense physical activity can induce high levels of genomic damage, while moderate exercise can elicit a favorable adaptive response by the organism. We evaluated, by the buccal micronuclei assay, the frequencies of micronuclei, nuclear buds and binucleated cells in a sample of amateur athletes practicing different disciplines, comparing the obtained data with those of subjects who practiced sports just occasionally and subjects that did not practice sport at all. The aim was to evaluate whether physical activity affects background levels of genomic damage and whether the different sports disciplines, as well as some gene polymorphisms, differentially affect these levels. A total of 206 subjects, 125 athletes and 81 controls, were recruited. Athletes showed significantly lower values of micronuclei, nuclear buds and binucleated cells with respect to controls. Sprinters and Martial Artists displayed significantly higher frequencies of micronuclei than other categories of athletes. Finally, neither sex nor gene polymorphisms seemed to influence the levels of genomic damage, confirming that the observed genomic damage is probably due to the nature of the sport activity.

The effects of non-functionalized polystyrene nanoparticles of different diameters on the induction of apoptosis and mTOR level in human peripheral blood mononuclear cells

Particles of various types of plastics, including polystyrene nanoparticles (PS-NPs), have been determined in human blood, placenta, and lungs. These findings suggest a potential detrimental effect of PS-NPs on bloodstream cells. The purpose of this study was to assess the mechanism underlying PS-NPs-induced apoptosis in human peripheral blood mononuclear cells (PBMCs). Non-functionalized PS-NPs of three diameters: 29 nm, 44 nm, and 72 nm were studied used in this research. PBMCs were isolated from human leukocyte-platelet buffy coat and treated with PS-NPs at concentrations ranging from 0.001 to 200 μg/mL for 24 h. Apoptotic mechanism of action was evaluated by determining the level of cytosolic calcium ions, as well as mitochondrial transmembrane potential, and ATP levels. Furthermore, detection of caspase-8, -9, and -3 activation, as well as mTOR level was conducted. The presence of apoptotic PBMCs was confirmed by the method of double staining of the cells with propidium iodide and FITC-conjugated Annexin V. We found that all tested NPs increased calcium ion and depleted mitochondrial transmembrane potential levels. The tested NPs also activated caspase-9 and caspase-3, and the smallest NPs of 29 nm of diameter also activated caspase-8. The results clearly showed that apoptotic changes and an increase of mTOR level depended on the size of the tested NPs, while the smallest particles caused the greatest alterations. PS-NPs of 26 nm of diameter activated the extrinsic pathway (increased caspase-8 activity), as well as intrinsic (mitochondrial) pathway (increased caspase-9 activity, raised calcium ion level, and decreased transmembrane mitochondrial potential) of apoptosis. All PS-NPs increased mTOR level at the concentrations smaller than those that induced apoptosis and its level returned to control value when the process of apoptosis escalated.

Systematic review of genotoxicity induced by occupational exposure to antineoplastic drugs

With increasing numbers of cancer cases, the use of antineoplastic agents is expected to rise. This will be accompanied by an increase in occupational exposure, which can cause unwanted health effects in workers. Our aim was to give an overview of genotoxic and epigenetic effects after occupational exposure to antineoplastic agents and to assess the concentration-effect relation. Four databases were searched for papers investigating genotoxic and/or epigenetic effects of occupational exposure to antineoplastic agents. Out of the 245 retrieved papers, 62 were included in this review. In this systematic literature review, we confirmed that exposure of healthcare workers to antineoplastic agents can lead to genotoxic damage. However, we observed a lack of data on exposure as well as genotoxic and epigenetic effects in workers other than healthcare workers. Furthermore, gaps in the current knowledge regarding the potential epigenetic effects caused by antineoplastic drug exposure and regarding the link between internal antineoplastic drug concentration and genotoxic and epigenetic effects after occupational exposure to antineoplastic agents were identified, offering a first step for future research.

The meta-analysis of cytogenetic biomarkers as an assessment of occupational risk for healthcare workers exposed to antineoplastic drugs

OBJECTIVE

Antineoplastic drugs (ADs) are widely used in clinical practice and have been demonstrated to be effective in treating malignant tumors. However, they carry a risk of cytogenotoxicity for healthcare workers. Studies have reported that genotoxic biomarkers can be applied to assess the occupational health status of healthcare workers at an early stage, but results of different studies are variable. The objectives of the review were examine the association between long-term exposure to ADs and cytogenetic damage to healthcare workers.

METHODS

We systematically reviewed studies between 2005 and 2021 using PubMed, Embase and Web of Science databases that used cytogenetic biomarkers to assess occupational exposure to ADs in healthcare workers. We used RevMan5.4 to analyze the tail length parameters of the DNA, frequency of the chromosomal aberrations, sister chromatid exchanges and micronuclei. A total of 16 studies were included in our study. The studies evaluate the quality of the literature through the Agency for Healthcare Research and Quality.

RESULTS

The results revealed that under the random-effects model, the estimated standard deviation was 2.37 (95% confidence interval [CI] 0.92-3.81, P = 0.001) for the tail length parameters of the DNA, 1.48 (95% CI 0.71-2.25, P = 0.0002) for the frequency of chromosomal aberrations, 1.74 (95% CI 0.49-2.99, P = 0.006) for the frequency of sister chromatid exchanges and 1.64 (95% CI 0.83-2.45, P < 0.0001) for the frequency of micronuclei.

CONCLUSIONS

The results indicate that there is a significant association between occupational exposure to ADs and cytogenetic damage, to which healthcare workers should be alerted.

Polystyrene nanoparticles: the mechanism of their genotoxicity in human peripheral blood mononuclear cells

Plastic nanoparticles are widely spread in the biosphere, but health risk associated with their effect on the human organism has not yet been assessed. The purpose of this study was to determine the genotoxic potential of non-functionalized polystyrene nanoparticles (PS-NPs) of different diameters of 29, 44, and 72 nm in human peripheral blood mononuclear cells (PBMCs) (in vitro). To select non-cytotoxic concentrations of tested PS-NPs, we analyzed metabolic activity of PBMCs incubated with these particles in concentrations ranging from 0.001 to 1000 µg/mL. Then, PS-NPs were used in concentrations from 0.0001 to 100 μg/mL and incubated with tested cells for 24 h. Physico-chemical properties of PS-NPs in media and suspension were analyzed using dynamic light scattering (DLS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and zeta potential. For the first time, we investigated the mechanism of genotoxic action of PS-NPs based on detection of single/double DNA strand-breaks and 8-oxo-2'-deoxyguanosine (8-oxodG) formation, as well as determination of oxidative modification of purines and pyrimidines and repair efficiency of DNA damage. Obtained results have shown that PS-NPs caused a decrease in PBMCs metabolic activity, increased single/double-strand break formation, oxidized purines and pyrimidines and increased 8oxodG levels. The resulting damage was completely repaired in the case of the largest PS-NPs. It was also found that extent of genotoxic changes in PBMCs depended on the size of tested particles and their ζ-potential value.

Cytostatic drugs and risk of genotoxicity in health workers. A literature review

OBJECTIVE

To analyse the genotoxic risk of cytostatic drugs in health professionals after occupational exposure.

METHOD

Literature was searched for the databases PubMed, Lilacs, The Cochrane Library and Scopus with free and controlled language (MeSH terms) using boolean operators AND and OR. The research was limited to articles published between 2005-2016.

RESULTS

11 articles were selected depending on their relevancy to this review's aim. Nine of the 11 articles proved the existence of damage to genetic material (DNA) of health workers, who were exposed to cytostatics. Furthermore, current security practices do not eliminate the chance of exposure completely. Therefore, the creation of new clinical trials is required.

CONCLUSIONS

Handling cytostatic drugs can cause a genotoxic risk to health workers who are exposed to these substances. This exposure may cause damage on the workers' DNA. There are not enough data to prove a cause-effect relationship between the genotoxic risk and adverse reactions on individuals. Health education will be the main way to raise the awareness and prevention this problem.

Cystostatic drugs and risk of genotoxicity in health workers. A literature review

OBJECTIVE

To analyse the genotoxic risk of cytostatic drugs in health professionals after occupational exposure.

METHOD

The literature was searched using the databases PubMed, Lilacs, The Cochrane Library and Scopus with free and controlled language (MeSH terms) using Boolean operators AND and OR. The research was limited to articles published between 2005-2016.

RESULTS

11 articles were selected depending on their relevancy to this review's aim. Nine of the 11 articles proved the existence of damage to genetic material (DNA) of health workers, who were exposed to cytostatics. Furthermore, current security practices do not fully eliminate the chance of exposure. Therefore, new clinical trials are required.

CONCLUSIONS

Handling cytostatic drugs can cause a genotoxic risk to health workers who are exposed to these substances. This exposure may cause damage to the workers' DNA. There are not enough data to prove a cause-effect relationship between the genotoxic risk and adverse reactions in individuals. Health education will be the main way to raise awareness of and prevent this problem.

Association of GSTT1 null, XPD 751 CC and XPC 939 CC genotypes with increased levels of genomic damage among hospital pathologists

CONTEXT

Hospital workers are at risk for genotoxic damage following occupationally exposure to xenobiotics. Pathologists are exposed to chemicals during their use in health care environments, particularly throughout inhalation of airborne agents, absorption through skin or contact with the patient's body fluids.

OBJECTIVE

We evaluated the level of genomic damage in a sample of 61 hospital pathologists (occupationally exposed to antineoplastic drugs and sterilizing agents) and 60 control subjects.

MATERIALS AND METHODS

Lymphocytes were analyzed by SCEs and CAs assays and genotyped for GSTT1, GSTM1, CYP1A1 Ile/Val, XPD (A751C) and XPC (A939C) gene polymorphisms.

RESULTS

Pathologists showed significantly higher frequencies of SCEs and CAs with respect to control subjects. GSTT1 null genotype was found to be associated with higher SCEs and CAs frequencies, whereas XPD 751 CC and XPC 939 CC genotypes only with a higher level of SCEs.

DISCUSSION AND CONCLUSIONS

The SCEs and CAs results are consistent with other published data, placing hospital workers as a category at risk for genotoxic damage caused by chronic exposure to xenobiotics. The higher levels of cytogenetic damage observed among GSTT1 null, XPD 751 and XPC 939 CC homozygote subjects confirm the importance of the genetic polymorphisms analysis associated to genotoxicological studies.

Re-evaluation of the WHO (2010) formaldehyde indoor air quality guideline for cancer risk assessment

In 2010, the World Health Organization (WHO) established an indoor air quality guideline for short- and long-term exposures to formaldehyde (FA) of 0.1 mg/m3 (0.08 ppm) for all 30-min periods at lifelong exposure. This guideline was supported by studies from 2010 to 2013. Since 2013, new key studies have been published and key cancer cohorts have been updated, which we have evaluated and compared with the WHO guideline. FA is genotoxic, causing DNA adduct formation, and has a clastogenic effect; exposure-response relationships were nonlinear. Relevant genetic polymorphisms were not identified. Normal indoor air FA concentrations do not pass beyond the respiratory epithelium, and therefore FA's direct effects are limited to portal-of-entry effects. However, systemic effects have been observed in rats and mice, which may be due to secondary effects as airway inflammation and (sensory) irritation of eyes and the upper airways, which inter alia decreases respiratory ventilation. Both secondary effects are prevented at the guideline level. Nasopharyngeal cancer and leukaemia were observed inconsistently among studies; new updates of the US National Cancer Institute (NCI) cohort confirmed that the relative risk was not increased with mean FA exposures below 1 ppm and peak exposures below 4 ppm. Hodgkin's lymphoma, not observed in the other studies reviewed and not considered FA dependent, was increased in the NCI cohort at a mean concentration ≥0.6 mg/m3 and at peak exposures ≥2.5 mg/m3; both levels are above the WHO guideline. Overall, the credibility of the WHO guideline has not been challenged by new studies.

Highly sensitive LC-MS/MS methods for urinary biological monitoring of occupational exposure to cyclophosphamide, ifosfamide, and methotrexate antineoplastic drugs and routine application

Highly sensitive ESI-LC-MS/MS methods were developed for urinary biological monitoring of occupational exposure to cyclophosphamide (CP), ifosfamide (IF), and methotrexate (MTX), which are hazardous antineoplastic drugs frequently handled by healthcare professionals. Extraction methods consisted of liquid/liquid extraction for simultaneous urinary CP and IF assays, and of solid phase extraction for the urinary MTX assay. A good linearity (r2>0.997), precision (CV<14.6%), and accuracy (bias<9.9%) were achieved for all compounds. The limit of detection (LOD) was 10pg/ml and the lower limit of quantification (LOQ) was 20pg/ml for all three drugs. Applying these methods in routine, more than 116 healthcare professionals occupationally exposed to antineoplastic drugs were monitored and 635 urines were analysed. Eleven healthcare professionals (9.5%) were found to be contaminated to at least one of the three antineoplastic drugs. Among analysed urines, 22 samples were found positives. The measured concentrations ranged from 20.1 to 1850pg/ml and, for six samples, concentrations were at CP trace level, between the LOD and LOQ values (10-20pg/ml). Such efficient analytical tools combining high specificity with high sensitivity are essential for reliable detection and routine biological monitoring of healthcare professionals occupationally exposed to these widely used antineoplastic drugs. These methods allow to monitor the healthcare professionals exposure to antineoplastic drugs in the aim to assess the effectiveness of collective and individual protective measures.

Chromosomal aberrations, sister chromatid exchanges, and micronuclei in lymphocytes of oncology department personnel handling anti-neoplastic drugs

OBJECTIVE

Concern exists regarding the possible hazards to the personnel handling anti-neoplastic drugs. The purpose of the present study was to assess the genotoxicity induced by anti-neoplastic agents in oncology department personnel.

MATERIALS AND METHODS

To do this, the frequency of chromosomal aberrations (CAs) induced in peripheral blood lymphocytes was assessed at G₀ phase of the cell cycle using metaphase analysis, cytokinesis block-micronucleus (MN) assay and sister chromatid exchange (SCE) assay. These cytogenetic end points were measured among 71 nurses in oncology department and 10 drugstore personnel handling and preparing anti-neoplastic drugs. The results were compared to those of 74 matched nurses for age and sex not exposed to any anti-neoplastic agents.

RESULTS

There was no significant difference between the age of study subjects and control group (p > 0.05). The results showed that the mean frequency of cytogenetic damages in terms of CAs [chromatid breaks (p = 0.01), chromosome breaks (p = 0.005), total CAs (p = 0.001)], MN formation (p = 0.001), and SCE (p = 0.004) in lymphocytes of personnel handling anti-neoplastic drugs were significantly higher than those in control unexposed group.

CONCLUSION

Results of the present study demonstrate the cytogenetic damage in peripheral blood lymphocytes of oncology department personnel. Suitable training and proper knowledge when handling anti-neoplastic drugs are emphasized to avoid potential health hazards caused by cytostatic agents.

The effect of catechol on human peripheral blood mononuclear cells (in vitro study)

Catechol also known as pyrocatechol or 1,2-dihydroxybenzene is formed endogenously in the organism from neurotransmitters including adrenaline, noradrenaline, and dopamine. It is also a metabolite of many drugs like DOPA, isoproterenol or aspirin and it is also formed in the environment during transformation of various xenobiotics. We evaluated in vitro the effect of catechol on the structure and function of human peripheral blood mononuclear cells (PBMCs). The cells were incubated with xenobiotic at concentration range from 2 to 500μg/mL for 1h. Human blood mononuclear cells were obtained from leucocyte-platelet buffy coat taken from healthy donors in the Blood Bank of Łódź, Poland. Using flow cytometry we have evaluated necrotic, apoptotic and morphological changes in PBMCs incubated with catechol. Moreover, we have estimated changes in reactive oxygen species (ROS) formation, protein carbonylation and lipid peroxidation in the cells studied. The compound studied provoked necrotic (from 250μg/mL), apoptotic (from 100μg/mL), and morphological changes (from 250μg/mL) in the incubated cells. We have also noted that catechol decreased H2DCF oxidation at 2 and 10μg/mL but at higher concentrations of 250 and 500μg/mL it caused statistically significant increase in the oxidation of this probe. We also observed an increase in lipid peroxidation (from 250μg/mL) and protein carbonylation (from 50μg/mL) of PBMCs. It was observed that catechol only at high concentrations was capable of inducing changes in PBMCs. The obtained results clearly showed that catechol may induce change in PBMCs only in the caste of poisoning with this compound.