Jenő Major

Lymphocyte phenotype analysis and chromosome aberration frequency of workers occupationally exposed to styrene, benzene, polycyclic aromatic hydrocarbons or mixed solvents

The aim of our study was to investigate the immunotoxicity of benzene, styrene and polycyclic aromatic hydrocarbon exposure, to establish the correlation between immunological and genotoxicological parameters, and to assess the possible effect of confounding factors such as age and smoking. The immune status of the donors was characterized by measuring the surface antigens of peripheral lymphocytes. The studied antigens were the following: CD3, CD4, CD8, CD14, CD19, CD25, CD38, CD45, CD45RO, CD54, CD56, CD62L, CD71 and HLA-DR. In our studies, we compared the immunological and genotoxicological parameters (chromosome aberration, sister chromatid exchange frequency, unscheduled DNA synthesis) of the different groups with healthy controls. Analysis revealed changes in the expression of surface antigens on peripheral lymphocytes in correlation with exposure. Confounding factors, such as smoking, increased the proportion of CD4 positive T lymphocytes and influenced the surface expression of several antigens. In our investigation the occurrence of chromosome aberrations negatively correlated with CD25 (IL-2R) expression in both CD4 and CD8 positive T cells. The presented data suggest that solvents such as benzene, styrene and PAHs activate peripheral lymphocytes, and cause changes in the incidence of CD25+/CD4+ T lymphocytes that may represent a distinct subset of immune-regulatory T cells.

Formaldehyde-induced chromosomal aberrations and apoptosis in peripheral blood lymphocytes of personnel working in pathology departments

Peripheral blood lymphocytes (PBL) of 37 formaldehyde-exposed women from four pathology departments in Hungary were investigated to collect data on the effects of occupational exposures to formaldehyde and to find a possible relationship between in vivo formaldehyde-induced apoptosis and genotoxic effects. The subjects were divided into two groups: 16 donors exposed to formaldehyde together with various organic solvents, and 21 subjects exposed mainly to formaldehyde. The results were compared with 37 controls (all women) without known occupational exposure. Ambient air concentrations of formaldehyde were measured in three work places, and ranged from 0.23 to 1.21mg/m(3) (mean 0.9mg/m(3)). Measures of genotoxicity included the determination of the frequencies of chromosomal aberrations (CA), sister-chromatid exchange (SCE), HPRT mutations (variant frequency, VF) and the measurement of UV-induced unscheduled DNA-repair synthesis (UDS). The percentages of premature centromere division (PCD) and of cells with a high frequency of SCE (HF/SCE) were also scored. Apoptosis and cell proliferation were determined by flow cytometry. In both formaldehyde-exposed groups, the apoptotic activity and the CA levels in PBLs were significantly higher than in controls. The CA were mostly breaks of the chromatid type. In the second group, which was mainly exposed to formaldehyde, CA were slightly lower in comparison with the group exposed to formaldehyde and solvents, which may be attributed to a different rate of elimination of damaged lymphocytes as a consequence of formaldehyde-induced apoptotic activity. In the second group, a significant decrease of VF and a non-significant increase in HF/SCE were found compared with the control and the other group. In conclusion, the results demonstrate that exposure to formaldehyde induces apoptosis and CA, indicating an excess cancer risk among subjects occupationally exposed to formaldehyde. The results also emphasize the importance of the measurement of occupational air pollutants, such as formaldehyde, in order to avoid genotoxic effects in the workers.

Follow-up biological and genotoxicological monitoring of acrylonitrile- and dimethylformamide-exposed viscose rayon plant workers

In order to investigate the genotoxic effects of occupational acrylonitrile (ACN) and dimethylformamide (DMF) exposures, clinical serum and urine parameters and genotoxicological endpoints such as chromosome aberration (CA), sister chromatid exchange (SCE), high frequency SCE (HFC), cell cycle kinetics, and UV‐induced unscheduled DNA synthesis (UDS) were followed up three times during a 20‐month period in peripheral blood lymphocytes (PBL) of 26 workers (13 maintainers and 13 fiber producers) occupationally exposed to ANC and/or DMF in a viscose rayon plant, 26 matched control subjects, and six industrial controls (all males). Six of the 26 exposed subjects were hospitalized because of liver dysfunction that had developed due to inhalative DMF exposure. The rate of smoking was estimated on the basis of serum thiocyanate (SCN) levels. Average peak air ACN and DMF concentrations were over the maximum concentration limits at the time of both investigations. Urine ACN and monomethyl‐formamide (MMF) excretions of the exposed subjects were almost doubled after work shifts. An increase in lymphocyte count (in months 0 and 7), and severe alterations in the liver function were observed in the exposed subjects. In PBLs the proliferative rate index (PRI) was already increased in month 0 compared with the controls. In each study, significant increases in CA and SCE frequencies, as well as increases in UDS were found in PBLs of the exposed subjects. The frequencies of chromatid breaks and acentric fragments further increased in month 7 and remained constantly elevated in month 20. Increased yields of both chromatid and chromosome‐type exchange aberrations first appeared in month 20, when HFCs were 2.72 times more frequent in fiber producers than in maintainers. The role of some important biological confounding factors (age, white blood cell count, and hematocrit) and lifestyle confounding factors (smoking and drinking habits) were subjected to an analysis of variance during the second study. Increased CA, SCE, and UDS were found both in control and exposed smokers when current smoking was established on the basis of the serum SCN levels. The cytogenetic data suggest that occupational exposures to ACN and DMF induce considerable genotoxic consequences and may increase the cancer risk in the exposed human populations. Environ. Mol. Mutagen. 31:301–310, 1998

Genotoxicological monitoring of 175 subjects living in the green belts, inner town or near chemical industrial estates in Greater Budapest agglomeration, Hungary.

We studied the effects of chronic low dose exposure to environmental pollutants on the peripheral blood lymphocytes (PBL) of subjects living in the green belts and the inner town, and/or working in the surrounding of industrial estates of Greater Budapest agglomeration, Hungary. The effects of some biological (gender, age, hematocrit and white blood cell counts), lifestyle (smoking, drinking habits and residential areas), and seasonal confounding factors were also considered. PBLs of 175 Hungarian donors of Budapest agglomeration, i.e. 45 subjects living in the green belts without significant genotoxic exposure (C1), 43 donors living in the inner town (C2), and 87 individuals living and/or working near chemical industrial estates (C3), were analysed for structural and numeric chromosome aberrations (CA), sister-chromatid exchanges (SCE), cell proliferation indices (lectine stimulation, LI; and proliferation rate index, PRI), and UV-light-induced unscheduled DNA synthesis (UDS). Each subject was interviewed personally and also investigated clinically. The three populations were matched for age, smoking and drinking habits. We excluded all donors with acute infectious and/or chronic non-infectious diseases, and/or with exposure to any known chemical hazard. For C1s, the base line CA and SCE frequencies were 0.25% and 6.41 per mitosis, respectively; in C2, these frequencies were 0.48% and 6.07 per mitosis, respectively, and in C3, these data were 1.60% and 5.71 per mitosis, respectively. A significant increase of CA due to chromosome type acentric fragments was demonstrated in the donors living in the inner town (C2), compared to those living in the green belts (C1). In C3s, significant (p < 0.05) elevations were found in the frequencies of gaps, aberrant cells, total aberrations (excluding gaps), chromatid and chromosome type aberrations, and in UDS, compared to C1s. Results indicate an increased genotoxicologic risk in donors living and/or working in industrial areas. Gender-related differences in SCE frequencies were demonstrated in C2 and C3; in the latter smoking-induced changes in UDS were also found. Light drinking did not appear to influence the results.

Immunotoxicity Monitoring of Hospital Staff Occupationally Exposed to Cytostatic Drugs

The aim of our study was to investigate the immunotoxicity of occupational cytostatic drug exposure, and to assess the possible effect of confounding factors, such as age and smoking. In this human study, the immunotoxic effect of antineoplastic drugs was investigated among 306 nurses working in oncology chemotherapy units. Results were compared to 98 non-exposed women. The immune status of the subjects was characterized by immune phenotyping of peripheral blood lymphocytes by flow cytometry, using monoclonal antibodies against surface antigens (CD3, CD4, CD8, CD19, CD25, CD45, CD56 and CD71). The killing ability of neutrophil leukocytes was assessed by the measurement of reactive oxygen intermediate production. Occupational exposure to antineoplastic drugs caused shifts in the major lymphocyte subpopulations, resulting in a statistically significant increase in the ratio of B cells. Cytostatic drug exposure also manifested itself in a decreased frequency of CD25 positive, activated T lymphocytes, and increased oxidative burst of neutrophil granulocytes, both of which may have a functional impact on the immune system of exposed subjects. In the younger subjects exposure also caused a shift in T cell subpopulations: a reduction in the cytotoxic T cell population lead to an elevated Th/Tc ratio. In the exposed group, smoking increased activation of T lymphocyte subpopulations. In conclusion, we have demonstrated that low dose occupational cytostatic drug exposure is immunotoxic, and age and smoking modify the effect of exposure.

The somatostatin analogue peptide TT-232 induces apoptosis and chromosome breakage in cultured human lymphocytes

Somatostatin receptors are supposed to be important in the regulation of apoptosis. In this study, we measured apoptosis occurring spontaneously, or induced by the synthetic somatostatin analogue, the peptide TT-232. We examined isolated human peripheral blood lymphocytes (PBL) from 32 nurses exposed bedside to cytostatic drugs, 12 chronic lymphoid leukaemia (CLL) patients prior to treatment, and 19 unexposed, healthy donors without anamnestic occupational exposure to genotoxic agents. Cells were stimulated by phytohaemagglutinin-P (PHA) and cultured for 69 h with or without 15 microg/ml TT-232, respectively. Cell kinetic parameters and apoptosis were determined by flow cytometry after staining with FITC-labeled anti-BrdU and propidium iodide (PI) and the results on spontaneous and peptide-induced apoptosis were compared with the obtained chromosome aberration frequencies (CA). The peptide TT-232 unexpectedly induced chromosome breakage in addition to apoptosis. The mean spontaneous apoptotic fractions were 6.65+/-0.89%, 6.46+/-0. 53%, and 3.07+/-0.57%, and the mean CA yields in the samples without TT-232 were 1.74+/-0.46%, 2.44+/-0.40%, and 4.50+/-1.05%, for healthy subjects, nurses, and CLL patients, respectively. A total of 15 microg/ml TT-232 treatment in healthy subjects increased the mean CA frequency (10.38+/-1.57%), as well as the apoptotic cell fraction (2.63+/-0.45 times higher than the corresponding untreated sample). In TT-232-treated PBLs of nurses, CA remained unchanged and the mean apoptotic cell fraction showed only a slight increase (1.24+/-0.11 times higher than the untreated). Among CLL patients, TT-232 treatment significantly increased both CA (up to 17.83+/-4.04%) and the ratio of apoptotic cells (21.78+/-11.00 times higher than the untreated). These results demonstrated significant differences in apoptosis sensitivity in controls, nurses and CLL donors, after 15 microg/ml TT-232 treatment. Data also indicate that the induced CA yields in CLL donors with high CA are in correlation with TT-232-induced apoptosis.

Health, Genotoxicology, and Immune Status of Road Pavers in Hungary

Bitumen (asphalts) used for road pavement in Hungary have a low tar content since the 1960s. However, traditional bitumen, as a substance belongs to the IARC Group 2B of carcinogens, because of its tar content, which was radically reduced in the last decades to develop an environmentally friendly substance. Other carcinogens in the working environment which are used, are solvents such as crude oils (Group 1), and diesel exhaust gases (Group 2A). Lifestyle factors also affect the health status of road pavers. The aim of this study was to investigate the changes in health status and geno- and immunotoxicology parameters of asphalt exposed road pavers. Multiple end-point follow-up genotoxicology monitoring was performed in Hungarian road pavers between 1996–1999 and 2003–2006. The latter set was supplemented with immunotoxicological endpoints. Studied subjects were interviewed by a physician to collect data on age, medication, smoking and drinking habits, medical and work histories, and they took part in a routine clinical laboratory check-up, including hematology, liver and kidney function tests and risk factors. The multiple end-point genotoxicology monitor, developed in our laboratory, includes the determination of chromosome aberration (CA), sister-chromatid exchange, and HPRT mutation frequencies and the measurement of DNA repair performed in peripheral blood lymphocytes according to the standard methods. Immunotoxicology monitoring includes determination of lymphocyte subpopulations and the measurement of lymphocyte activation. Altogether 89 asphalt-exposed workers (23 managers, 23 hand pavers, 28 finishers and 15 mixers) were investigated. The results were compared to 33 non-exposed industrial controls. More than half of the studied subjects were active smokers and more than 80% were regular drinkers. Among the exposed the most frequent clinical symptoms were liver and kidney dysfunctions, hypertension, hyperglycemia, high cholesterol, rheumatoid complaints and high count of white blood cells. However, the low exposed management also suffered from hypertension, hyperglycemia and high cholesterol. For genotoxicology monitoring the most significant changes were in the mean CA yields. At the start (1996) CA was increased in exposed subjects. The highest CA was found among mixers, and CA was also elevated among finishers working in closed cabins and pavers cleaning equipment with crude oil. By 1999 the CAs of exposed subjects decreased and remained at the level of industrial controls, except that of mixers still above the control level in 2004. The immunotoxicological tests showed a shift of lymphocyte subpopulations both in the exposed workers and management controls as well as the activation of T and B cells. Alterations found in clinical parameters except rheumatoid complaints can be attributed to the lifestyles of the studied subjects. Data suggest that the main genotoxic agents were exhaust gases in the closed cabins among finishers and crude oil used for cleaning in pavers, as proper ventilation and the use of harmless detergents resulted in the decrease of CA yields.

Citosztatikus kezelést végző kórházi dolgozók pajzsmirigy-elváltozásainak géntoxikológiai és immuntoxikológiai vonatkozásai@@@Genetic and immune-toxicologic studies on abnormal thyroid functions in hospital employees exposed to cytostatic drugs

INTRODUCTION Environmental exposure to harmful chemicals may produce severe consequences. AIM The aim of the authors was to perform geno- and immune-toxicological monitoring in female employees occupationally exposed to cytostatic agents in hospitals and compare the findings to those obtained from controls. METHOD Altogether 642 women working in hospital who were occupationally exposed to cytostatic drugs and 262 control women participated in the study. Frequency of chromosome aberrations, immune phenotype and activation of lymphocytes, and the production of reactive oxygen-species in neutrophil granulocytes were determined. RESULTS Markedly higher number (n=39) of thyroid alterations was observed among exposed subjects as compared to controls (n=3). In persons with abnormal thyroid functions, the frequency of chromosome aberrations (3.69%) was significantly higher (3.69%) than in exposed subjects without thyroid alterations (2.43%) and in controls (1.70% and 1.60% in control subjects with and without thyroid alterations, respectively). Significantly increased ratio of helper T lymphocytes and decreased ratio of cytotoxic T cells and transferrin-receptor (CD71) expressing B cells were observed in exposed subjects having abnormal thyroid functions as compared to controls. In addition, the ratio of B cells, CD71 expressing T cells and production of reactive oxygen-intermediates was significantly decreased in exposed subjects with thyroid alterations in comparison to exposed subjects without thyroid alterations. CONCLUSIONS The results indicate increased geno- and immune-toxic effects among exposed subjects having thyroid alterations. Further data are needed to clearly establish the underlying pathophysiological mechanism of this finding.Bevezetes: A veszelyes kornyezeti artalmak komoly kovetkezmenyeket okozhatnak. Celkitűzes: A szerzők citosztatikus kezelest vegző korhazi nőverek (nők) koreben folytattak gen- es immuntoxikologiai vizsgalatokat, es az eredmenyeket kontrollcsoporthoz hasonlitottak. Modszer: A vizsgalatban 642, citosztatikumexponalt korhazi nőver es 262 kontrollszemely (nő) vett reszt. A lymphocytakban meghataroztak a kromoszomaaberraciok gyakorisagat, immunfenotipusat es aktivaltsagat, valamint a neutrophil granulocytakban a reaktivoxigenintermedier-termelest. Eredmenyek: A citosztatikumexponaltak csoportjaban 39, mig a kontrollcsoportban mindossze 3 pajzsmirigybeteggel talalkoztak. Citosztatikumexponalt pajzsmirigybetegeknel szignifikansan gyakoribb volt a kromoszomaaberracio (3,69%), mint a pajzsmirigyelterest nem mutato exponaltaknal (2,43%) es a kontrolloknal (pajzsmirigyelteres nelkuli kontrollszemelyeknel 1,60%, pajzsmirigybetegeknel 1,70%), emellett szignifikansan emelkedett a helper, csokkent a citotoxikus T-lymphocytak es a transzferrinreceptort (CD71) expresszalo B-sejtek aranya a kontrollokhoz kepest. A pajzsmirigyelteressel nem rendelkező citosztatikumexponaltakhoz kepest a citosztatikumexponalt pajzsmirigybetegekben szignifikansan csokkent a B-sejtek es a CD71-et expresszalo T-sejtek aranya, valamint a reaktivoxigenintermedier-termeles. Kovetkeztetesek: Az eredmenyek a pajzsmirigyeltereseket mutato exponaltaknal fokozott gen- es immuntoxikologiai hatasokra utalnak a pajzsmirigyelteresekkel nem rendelkező exponaltakhoz kepest is, amelyek koroki osszefuggeset jovőbeni kutatasok hivatottak eldonteni. Orv. Hetil., 2015, 156(2), 60–66.

Genetic and immune-toxicologic studies on abnormal thyroid functions in hospital employees exposed to cytostatic drugs

INTRODUCTION Environmental exposure to harmful chemicals may produce severe consequences. AIM The aim of the authors was to perform geno- and immune-toxicological monitoring in female employees occupationally exposed to cytostatic agents in hospitals and compare the findings to those obtained from controls. METHOD Altogether 642 women working in hospital who were occupationally exposed to cytostatic drugs and 262 control women participated in the study. Frequency of chromosome aberrations, immune phenotype and activation of lymphocytes, and the production of reactive oxygen-species in neutrophil granulocytes were determined. RESULTS Markedly higher number (n=39) of thyroid alterations was observed among exposed subjects as compared to controls (n=3). In persons with abnormal thyroid functions, the frequency of chromosome aberrations (3.69%) was significantly higher (3.69%) than in exposed subjects without thyroid alterations (2.43%) and in controls (1.70% and 1.60% in control subjects with and without thyroid alterations, respectively). Significantly increased ratio of helper T lymphocytes and decreased ratio of cytotoxic T cells and transferrin-receptor (CD71) expressing B cells were observed in exposed subjects having abnormal thyroid functions as compared to controls. In addition, the ratio of B cells, CD71 expressing T cells and production of reactive oxygen-intermediates was significantly decreased in exposed subjects with thyroid alterations in comparison to exposed subjects without thyroid alterations. CONCLUSIONS The results indicate increased geno- and immune-toxic effects among exposed subjects having thyroid alterations. Further data are needed to clearly establish the underlying pathophysiological mechanism of this finding.Bevezetes: A veszelyes kornyezeti artalmak komoly kovetkezmenyeket okozhatnak. Celkitűzes: A szerzők citosztatikus kezelest vegző korhazi nőverek (nők) koreben folytattak gen- es immuntoxikologiai vizsgalatokat, es az eredmenyeket kontrollcsoporthoz hasonlitottak. Modszer: A vizsgalatban 642, citosztatikumexponalt korhazi nőver es 262 kontrollszemely (nő) vett reszt. A lymphocytakban meghataroztak a kromoszomaaberraciok gyakorisagat, immunfenotipusat es aktivaltsagat, valamint a neutrophil granulocytakban a reaktivoxigenintermedier-termelest. Eredmenyek: A citosztatikumexponaltak csoportjaban 39, mig a kontrollcsoportban mindossze 3 pajzsmirigybeteggel talalkoztak. Citosztatikumexponalt pajzsmirigybetegeknel szignifikansan gyakoribb volt a kromoszomaaberracio (3,69%), mint a pajzsmirigyelterest nem mutato exponaltaknal (2,43%) es a kontrolloknal (pajzsmirigyelteres nelkuli kontrollszemelyeknel 1,60%, pajzsmirigybetegeknel 1,70%), emellett szignifikansan emelkedett a helper, csokkent a citotoxikus T-lymphocytak es a transzferrinreceptort (CD71) expresszalo B-sejtek aranya a kontrollokhoz kepest. A pajzsmirigyelteressel nem rendelkező citosztatikumexponaltakhoz kepest a citosztatikumexponalt pajzsmirigybetegekben szignifikansan csokkent a B-sejtek es a CD71-et expresszalo T-sejtek aranya, valamint a reaktivoxigenintermedier-termeles. Kovetkeztetesek: Az eredmenyek a pajzsmirigyeltereseket mutato exponaltaknal fokozott gen- es immuntoxikologiai hatasokra utalnak a pajzsmirigyelteresekkel nem rendelkező exponaltakhoz kepest is, amelyek koroki osszefuggeset jovőbeni kutatasok hivatottak eldonteni. Orv. Hetil., 2015, 156(2), 60–66.

Comet assay alkalmazása olaj- és vegyipari exponált dolgozók kockázatbecslésében@@@Use of comet assay for the risk assessment of oil- and chemical-industry workers

INTRODUCTION The comet assay is a fluorescent microscopic method that is able to detect DNA strand-breaks even in non-proliferative cells in samples with low cell counts. AIM The aim of the authors was to measure genotoxic DNA damage and assess oxidative DNA damage caused by occupational exposure in groups exposed to benzene, polycyclic aromatic carbohydrates and styrene at the workplace in order to clarify whether the comet assay can be used as an effect marker tool in genotoxicology monitoring. METHOD In addition to the basic steps of the comet assay, one sample was treated with formamido-pirimidine-DNA-glycolase restriction-enzyme that measures oxidative DNA damage. RESULTS An increase was observed in tail moments in each group of untreated and Fpg-treated samples compared to the control. CONCLUSIONS It can be concluded that occupational exposure can be detected with the method. The comet assay may prove to be an excellent effect marker and a supplementary technique for monitoring the presence or absence of genotoxic effects.