Evaluation Of Micronuclei Research Articles

Evaluation of micronuclei in tobacco users: A study in Punjabi population

Introduction:The assessment of micronuclei in exfoliated cells is a promising tool for the study of epithelial carcinogens and can be used to detect chromosome breakage or mitotic interference, thought to be relevant to carcinogenesis.Aim:The present study aimed to detect micronuclei in exfoliated oral mucosal cells in individuals using various tobacco forms from the last 5 years.Materials and Methods:A total of 75 healthy male subjects (25 smokeless tobacco users, 25 smokers, and 25 non–tobacco users) were selected for the study. Smears were obtained with moistened wooden spatula from buccal mucosa and fixed with 95% alcohol. All the cytologic smears were stained by Papanicolaou technique. From each slide, ~1000 cells were examined under the 400× magnification and where micronucleated (MN) cells were located, they were examined under the 1000× magnification.Result:MN cells were found to be significantly higher in smokeless tobacco users than in smokers and controls.Conclusion:A positive correlation is found between increased micronucleus frequency and tobacco-using habits. So micronucleus assay can be used as a biomarker of genotoxicity.

Micronucleus evaluation for determining the chromosomal breakages after radionuclide synovectomy in patients with hemophilia

To investigate the genotoxic effects of (90)Y and (186)Re in patients with hemophilia who were undergoing radionuclide synovectomy (RS) procedure in the last 3years. Nineteen patients were enrolled in the study. Most of the patients (n=17) were hemophilia-A (mean age 20.6±10.5years) and 18 patients (mean age 22.6±10.6years) with hemophilia who were not exposed to RS procedure were included in the study as control group. Most cases in the control group (n=13) were hemophilia-A. (90)Y for knee joints and (186)Re for elbow or ankle joints were used to perform RS in hemophilic patients. We studied the micronucleus (MN) test on peripheral blood lymphocytes as an indicator of radiation-induced cytogenetic damage and calculated nuclear division index. There was no significant difference between the patients with and without RS with respect to MN values. However, both values obtained in RS-exposed patients and control group were much elevated than values reported in literature from healthy controls. The mean MN values of patients below 20years old were much lower but not significant than those above 20years old. MN frequencies between (186)Re and (90)Y groups were also analyzed, and no significant difference was observed. Hemophilia patients who were treated with (186)Re showed higher levels of MN compared to patients treated with (90)Y although the difference was not significant. Radioisotope synovectomy (RS) seems to be a safe procedure not causing a significant genotoxic effect on hemophilic patients, however, further studies including larger series of patients are needed to better understand the effects of RS on patients' health.

Micronucleus evaluation in mitogen-stimulated lymphocytes of patients with acromegaly

Acromegaly is a syndrome characterized by a sustained elevation of circulating growth hormone and insulin-like growth factor-1 (IGF-1). Insulin-like growth factor-1 is a potent mitogen and has a role in the transformation of normal cells to malignant cells. This study aims to evaluate the spontaneous micronucleus (MN) frequency by using the cytokinesis-block MN assay to determine genetic damage in the lymphocytes of patients with acromegaly. The study was carried out in 20 patients who had active acromegaly and in 20 age- and sex-matched healthy controls. The MN values were measured in binucleated cells obtained from mitogen-stimulated lymphocytes of patients and control subjects. The distribution of binucleated cells with 1, 2, 3, or more MNs was also measured. We found significantly higher MN frequency values in the lymphocytes of acromegalic patients than in those of the control subjects (2.23 ± 0.68 vs 1.03 ± 0.54, P = .001). The MN frequency increased with increasing IGF-1 levels of acromegalic patients (P = .036, R = 0.47). We observed that the number of binucleated cells with 2 MNs was higher for the majority of patients with acromegaly than for control subjects. Furthermore, the receiver operating characteristic curve (area under the curve = 0.914, P < .0001) was calculated to assess the discriminative power of the MN frequency. Our results indicate that increased MN frequency in the lymphocytes of patients with acromegaly may reflect genomic instability and this increased MN frequency may be associated with elevated levels of circulating growth hormone and IGF-1.

CYTOKINESIS-BLOCK MICRONUCLEUS (CBMN) ASSAY/CBMN CYTOME ASSAY IN HUMAN LYMPHOCYTES AFTER IN VITRO IRRADIATION AND ITS USE IN BIODOSIMETRY

Summary Aim: Cytokinesis-block micronucleus (CBMN) assay and its comprehensive variant CBMN cytome assay are cytogenetic methods. CBMN is based on assessment of micronuclei in nucleated cells that have completed only one nuclear division. Besides micronuclei, CBMN cytome assay analyzes additional genotoxic (nucleoplasmic bridges and nuclear buds), cytostatic (nuclear division index), and cytotoxic (amount of necrotic and apoptotic cells) parameters. The aim of this study is to evaluate these parameters in human blood lymphocytes after in vitro irradiation and to assess its contribution to biodosimetry. Material and methods: Human blood from 6 donors was in vitro irradiated by 0, 1, 2, 3, 4, or 5 Gy and cultivated for 72 hours. Blood lymphocytes were stimulated with phytohemagglutinin and their cytokinesis was blocked by cytochalasin B. After cultivation, cultures were hypotonically treated, dropped onto glass slides and stained with Giemsa. Slides were evaluated by microscope. Results: We observed significantly increased amount of micronuclei, nucleoplasmic bridges, and nuclear buds measured in binucleated cells, significantly increased amount of micronuclei measured in mononucleated cells and significantly decreased nuclear division index after irradiation by 1, 2, 3, 4, and 5 Gy. Amount of death cells (apoptotic and necrotic) significantly increased after irradiation by 4 and 5 Gy. Conclusion: Although all parameters assessed by CBMN cytome assay have biodosimetric potential, practically feasible is only evaluation of micronuclei in binucleated cells. This parameter was used to construct in vitro linear-quadratic dose-response calibration curve which could be used as a biodosimetric tool for triage of radiation casualties.

Mutagenicity of Immunosuppressive Medications among Renal Transplant Recipients

Background: Immunosuppressive therapy is essential for patients after renal transplantation, but it may have mutagenic side effects. The frequency of micronuclei (MN) assessed by the cytokinesis block assay is well established in the diagnosis of DNA damage. Methods: We examined 79 patients before and after renal transplantation with the cytokinesis block assay. For MN evaluation, the criteria of the Human Micron Nucleus (HUMN) project were used. Results: Age and sex had no influence on the number of MN before transplantation. Patients with a shorter time on dialysis had fewer MN than patients with a longer time on dialysis. After 3 weeks of immunosuppressive therapy, the ability of cells to proliferate was reduced; therefore, only 36 patients could be analyzed. In these patients, MN frequency rose significantly. There was no linear relationship between MN after transplantation and age, sex, time on dialysis or graft function. The majority of patients (79%) were treated with cyclosporine A, mycophenolate mofetil and methylprednisolone when leaving the hospital. There was no difference between the different therapeutic schemes with regard to MN frequency after transplantation, but patients with mycophenolate mofetil showed less cellular proliferation. The function of the transplanted organ or the occurrence of rejection had no effect on MN frequency after transplantation. Conclusion: In patients with renal transplantation, immunosuppressive therapy intensifies the genotoxic damage of the preceding chronic renal failure.

Oxidative stress in normal cells exposed to carbon ions

The high efficiency of carbon ions versus photons, with an RBE (Relative Biological Efficiency) of 2 to 3, to treat various tumours was demonstrated in the main hadrontherapy centers (GSI, Germany and HIMAC, Japan). However, few extensive studies were performed in order to evaluate the impact of high-LET exposure on healthy tissues. In spite of a better accuracy of a carbon beam as compared to photons, normal cells could also be irradiated in vicinity of the tumours treated. Thus, in order to evaluate the possible secondary effects of a carbon treatment, we compare the exposure of normal human cells to carbon ions (75 MeV/u) and to photons (X-rays). Survival curves were performed to select irradiation doses in both cases, X- or C-exposure. Oxidative stress was assessed in these cells to observe induced early and long-term cellular responses following radiation exposure (hours, days and weeks). Since exposure to high-LET ions is known to create DNA damage that are difficult to repair and that often lead to cell death, DNA damage were measured using global or cell level techniques as comet assay and γ-H2AX immunostaining. These measurements were performed soon after the exposure and also after different periods of recovery (1 and 3 hours). The evaluation of micronuclei in the cell cultures up to 21 days after irradiation was also a good indicator of the global management of DNA injury. Then, lipid peroxidation products (MDA, 4-HNE) were quantified as well as reactive oxygen species production (by flow cytometry using DCFH-DA and HE probes). Enzymatic defence systems (catalase, superoxide dismutase and glutathione peroxidase activities) and non-enzymatic defence systems (vitamin E, reduced/oxidized gluthatione) were also investigated. First results indicated an increased efficiency in producing oxidative damage after carbon ions exposure compared to X-rays.

Biomonitoring of the cytogenetic effect of antitumor therapy by means of micronucleus assay in exfoliated epithelial cells

Data are presented concerning the possibility of using the micronuclei (MN) level as a biomarker for cytogenetic effects in exfoliated epithelial cells of cancer patients under therapy. The number of MN in buccal cells of cancer patients under chemotherapy are very contradictory. A significant dose-dependent increment of MN in tumor and normal epithelial cells due to radiotherapy was shown in most investigations. Evaluation of MN induced by radiotherapy in exfoliated tumor cells can potentially identify the radiosensitivity of tumors and the outcome of treatment after the first fractions of irradiation. This technique is almost completely noninvasive and easily done in accessible primary cancers (oral cavity and uterine cervix).

Investigation of micronucleus frequencies in lymphocytes of inhabitants environmentally exposed to chrysotile asbestos

Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. Many of the regions of Turkey have asbestos deposits. People in Doğanlı village – one of these regions – have been environmentally exposed to chrysotile asbestos since they were born. In this study the effects of asbestos on micronucleus (MN) frequencies of inhabitants exposed to chrysotile asbestos have been examined. Thirty subjects who had been environmentally exposed to chrysotile asbestos and living in Doğanlı village, and 25 controls were studied to assess the MN frequency. The control group was selected from healthy individuals with no exposure to asbestos and living in similar geographic conditions to Doğanlı village. Peripheral blood samples were collected from each subject and cultured for MN assay. Cytochalasin-B was added to lymphocyte cultures for evaluation of MN in binucleated (BN) cells. The differences between those exposed to chrysotile asbestos and controls were not statistically significant in terms of BN cells with MN (p > 0.05). There was not a significant relationship between MN frequencies and age, sex, smoking, both in chrysotile asbestos-exposed subjects and in controls (p > 0.05). Although the detection of calcified pleural plaques found in the inhabitants has indicated environmental exposure to chrysotile asbestos, our results show that chrysotile asbestos was not an inducer of MN in subjects exposed to chrysotile asbestos.

SFTG international collaborative study on in vitro micronucleus test: II. Using human lymphocytes

This study on the in vitro micronucleus assay, comprising 11 laboratories using human lymphocytes, was coordinated by an organizing committee supported by the SFTG (the French branch of the European Environmental Mutagen Society). Nine coded substances were assessed for their ability to induce micronuclei in human lymphocytes in vitro, mitomycin C being used as a positive control. Cultures were exposed to the test substances for a short (early or late) time or for a long time, followed by a short or long recovery period, in the presence of cytochalasin B. Each chemical was evaluated, generally in two laboratories, using three treatment schedules at least twice. The data were assessed for acceptability, and then classified as negative, positive or equivocal. Two of seven genotoxic compounds, namely colchicine and bleomycin, clearly induced micronuclei. Reproducible results were difficult to obtain for some substances, which tended to be those acting at specific stages of the cell cycle. Cytosine arabinoside, diethylstilboestrol and 5-fluorouracil were classified as equivocal. Urethane and thiabendazole were classified as negative. The two presumed non-genotoxic compounds, mannitol and clofibrate, did not induce micronuclei. Repeat testing, exposing cells at both an early and late time after mitogenic stimulation, was needed to detect substances classified as equivocal. These results show the importance of achieving sufficient inhibition of nuclear division to avoid the possibility of missing an effect. The evaluation of micronuclei in mononucleated as well as binucleated cells was particularly useful to detect aneugens. There were no false positive results using lymphocytes, indicating a high specificity. It is concluded that the clastogenic or aneugenic potential in vitro of the substances tested was correctly identified in this study, but that refining the protocol to take into account factors such as the stages of the cell cycle exposed to the compound, or the duration of recovery would be likely to improve the sensitivity of detection using lymphocytes.

Micronucleus frequency in human umbilical cord lymphocytes

The human fetus is exposed to a variety of environmental agents and drugs which cross the placenta and can induce DNA damage. Micronucleus (MN) determination is a suitable and sensitive method for measuring DNA damage and since umbilical cord blood is obtained without any risk for the newborn, we measured the frequency of MN in cells from cord blood in four groups of healthy newborns (NB): 35 NB whose mothers lived in two urban cities (groups I and II); 16 NB from an agricultural area (group III); and 15 NB of mothers with high-risk pregnancy (group IV). MN were also evaluated in the mothers of NB from group I ( n = 17) and group III ( n = 14). Acetylcholinesterase (AChE) concentration was measured in groups I and III. The average frequency of binucleated cells with MN was 3.7 ± 1.4 in 1000 cells in mothers and 1 ± 0.9 in 1000 cells in NB from urban areas; and 4.5 ± 2.4 in1000 cells in mothers and 2 ± 1.5 in 1000 cells in NB from the agricultural area. The correlation between the frequency of MN in mothers and NB was significant ( r = 0.61, p < 0.01). AChE levels of samples obtained both from group III mothers and from newborns were similar to those of group I. The Wilcoxon's rank-sum test was applied to measure differences in MN frequency; NB of group I were used as control group. A significant ( p < 0.01) higher frequency of MN (4 ± 2) was found only in lymphocytes from NB from high-risk pregnancies. Data indicate that MN evaluation in umbilical cord samples might be useful in the identification of transplacental mutagens.

P-448 Micronuclei evaluation of reduction in neoadjuvant chemotherapyrelated acute toxicity in Locally Advanced Non Small Cell Lung Cancer

P-448 Micronuclei evaluation of reduction in neoadjuvant chemotherapyrelated acute toxicity in Locally Advanced Non Small Cell Lung Cancer

Micronucleus evaluation in mitogen-stimulated lymphocytes of narrow-band (311 nm TL01) UVB-treated patients.

Narrow-band UVB (311 nm) lamps (TL01) are being increasingly used for phototherapy of psoriasis and other dermatoses, for their excellent effect compared with broad-band UVB sources and photochemotherapy. It is acknowledged that the TL01 lamp is probably two to three times more carcinogenic per minimum erythema dose than broad-band UVB, but the cumulative dose is considerably less than broadband UVB sources. Micronucleus (MN) test is used to detect both clastogenic (breaking) and aneugenic (abnormal segregation) effect of physical/chemical agents on chromosomes. The aim of this study is to evaluate MN frequencies in mitogen-stimulated lymphocytes of narrow-band UVB-treated patients. Frequency of micronuclei in 72 h cultivated/mitogen-stimulated lymphocytes of 36 patients (age 7-73 years, mean+/-SD: 25.33+/-18.54) have been evaluated at pretreatment and after 20, 40, 60 sessions of narrowband UVB treatment. While the beginning MN frequency +/-SD (%) was 1.07+/-0.63, it increased to 1.47+/-0.92, 1.47+/- 0.77, 1.41+/-0.31 corresponding, respectively, to 20, 40, 60 sessions. These sessions reciprocally correspond to 0.85+/-0.23, 2.97+/-0.72, 5.68+/-1.46 J/cm(2) doses of narrow-band UVB. Difference of MN frequency was statistically significant (P=0.002). Significant differences have been observed between the initial MN frequency and after that of 20, 40, 60 sessions (P=0.001, 0.004, 0.002, respectively). The results of this study show that narrow-band UVB treatment causes a detectable chromosome damaging effect.

Validation of a flow cytometric acridine orange micronuclei methodology in rats

Our laboratory has previously reported a flow cytometric acridine orange method for detection of micronucleus (MN) in the rat using cyclophosphamide as a test compound. To replace the manual method of scoring and satisfy Good Laboratory Practice (GLP) requirements, an extensive validation of the flow method was required. Therefore, manual scoring and flow cytometric determination of MN were compared using vincristine, chlorambucil, methotrexate, and doxorubicin compounds known to induce MN formation with various mechanisms of action. 1,2-Dimethylhydrazine (1,2-DH), a compound with negative or equivocal MN findings also was evaluated. The flow method consistently demonstrated dose- and time-dependent responses for MN production at all concentrations of vincristine, methotrexate, clorambucil, and doxorubicin. In contrast, manual scoring of slides failed to detect an increase in MN at the lowest doses of doxorubicin (1 mg/kg) at 24 or 48 h, and methotrexate at 48 h, or any dose of methotrexate (50, 100, or 250 mg/kg) at 24 h. Additionally, a dose–response for methotrexate at 48 h, and chlorambucil at 24 h were missed using manual scoring. For 1,2-DH, the flow method showed a low level (<1.4-fold) increase in MN at all doses and times. In contrast, the manual method showed five–seven-fold increases at 24 h, but a <two-fold increase at 48 h in the highest dose only. These data may suggest that the flow method has a greater sensitivity and possibly accuracy than manual scoring. Significant decreases in polychromatic erythrocytes (PCE) were seen using both methods at approximately the same dose for all compounds. However, absolute flow cytometric PCE values were consistently higher than manual. Additional cytotoxicity parameters obtained by the flow method allowed a more complete assessment of cytotoxicity than PCE alone. Furthermore, data reported here combined with improved throughput, shortened data turnaround and reporting times, and possibly better precision due to evaluation of much larger numbers of cells clearly demonstrate the usefulness of flow cytometry method in the routine micronucleus evaluation.

Micronucleus evaluation in mitogen-stimulated lymphocytes of PUVA treated patients.

PUVA describes the treatment of patients with psoralens plus an exposure to a source of UV light of 320-400 nm (UVA). Contradictory results have been reported on the chromosomal damage of PUVA when assayed by sister chromatid exchange (SCE) method. Micronucleus (MN) test is used to detect both clastogenic (breaking) and aneugenic (abnormal segregation) effect of physical/chemical agents on the chromosomes. No data have been found on the MN formation in the cells of PUVA treated patients. Frequency of micronuclei in 72 hours cultivated/mitogen-stimulated lymphocytes of patients have been evaluated at zero time and after 20, 40, 60 sessions of PUVA treatment. While the beginning MN frequency was approximately 0.22% (n=23), it raised to approximately 0.32 (n=23), approximately 0.42 (n=14) and approximately 0.53% (n=10) corresponding respectively to 20, 40 and 60 sessions. These sessions correspond reciprocally to 54+/-23, 172+/-48, 300+/-61 joules/cm2 of UVA and 13, 26, 39 mg/kg of 8-metoxypsoralen (8-MOP). While large interindividual variances were apparent, highly significant differences have been observed between initial MN frequency and after that of the 20, 40 and 60 sessions, (p = 0.000, p = 0.004, p = 0.005, reciprocally, Wilcoxon two-related samples test). The coefficient of correlation between MN frequency and UVA doses starting from zero to 60 sessions of treatment has been found as r = 0.61. This indicates a significant relationship between UVA doses and MN frequencies. However, MN inducibility and synergistic property of 8-MOP with UVA should be taken into account. Gradual MN increase during different sessions of PUVA treatment shows that--once appeared--a part of MN at least persist in the cells of patients from a few days to a few weeks. Smoking as a confounding factor seems to increase MN frequency (p = 0.053, Mann-Whitney U-test) in the beginning population, taken as the control population. This is the first report on the kinetics of MN formation during different sessions of PUVA treatment. Based on our results, we concluded that PUVA treatment causes a detectable chromosome damaging effect on the relatively profound cells/tissues of its human users. Therapists should be careful with its use, especially on the patients who may be more susceptible to carcinogenesis (e.g. immunosuppressed and/or elderly subjects).

In vivo rodent micronucleus assay: protocol, conduct and data interpretation

In vivo rodent micronucleus assay has been widely used to detect genotoxicity. Evaluation of micronucleus induction is the primary in vivo test in a battery of genotoxicity tests and is recommended by the regulatory agencies around the globe to be conducted as part of product safety assessment. The assay, when performed appropriately, detects both clastogenicity and aneugenicity. Methods for performing micronucleus evaluation have evolved since its initial description in the 1970s. In recent years, the focus has been directed toward improving micronucleus detection with high efficiency by proposing data-based recommendations to the standard initial protocol design. Such improvements include, e.g., the use of appropriate harvest time(s), inclusion of one or both sexes, number of doses tested, limit dose, integrating micronucleus assessment into the routine toxicology studies, use of fluorescent staining, automation of micronucleus detection and assessment of micronuclei in multiple tissues. This protocol paper describes: the mechanism of micronucleus formation, a generalized protocol for manual detection, enumeration of micronuclei, and data interpretation in light of published information thus far, on the regulatory aspects of this assay. Certain recent protocol issues that are practical in nature are equally valid in relation to standard manual method and provide robust database, which are also included for consideration. It is expected that such improvements of the protocol will continue to drive the utility of this assay in the product safety assessment.

Evaluation of micronuclei and chromosomal breakage in the 1cen-q12 region by the butadiene metabolites epoxybutene and diepoxybutane in cultured human lymphocytes.

1,3-Butadiene is a widely used industrial chemical and common environmental pollutant that has been associated with increased risks of leukemias and lymphomas. Butadiene and its metabolites, 1, 2-epoxybutene (EB) and diepoxybutane (DEB), have been shown to be genotoxic in a wide variety of test organisms. The objective of this research was to evaluate techniques for the rapid detection of chromosomal alterations occurring in humans exposed to butadiene. We have used a multicolored fluorescence in situ hybridization (FISH) method and the CREST-modified micronucleus assay to detect chromosomal breakage induced by EB (10-300 microM) and DEB (0.5-10 microM) in cultured human lymphocytes. A significant dose-related increase in the formation of micronuclei was seen in lymphocytes treated with DEB at concentrations as low as 2.5 microM, but not with EB over the dose range tested. Over 80% of the micronuclei induced by DEB were CREST-negative, indicating their origin from chromosomal breakage. Multicolor FISH using two adjacent chromosome-specific probes showed a significant increase in chromosomal breakage in the 1cen-q12 region induced by DEB at concentrations as low as 2.5 microM, but not by EB. Since DEB is likely to be one of the metabolites contributing to the genotoxic effects of butadiene, the sensitivity of the tandem FISH approach to detect breakage induced by diepoxybutane indicates that this technique may be useful for monitoring chromosomal alterations in butadiene-exposed workers.

OP3E144 - Rat alveolar type II cells—suitable model for evaluation of micronuclei induced by cigarette smoke

OP3E144 - Rat alveolar type II cells—suitable model for evaluation of micronuclei induced by cigarette smoke

Evaluation of micronuclei in exfoliated urothelial cells and urinary thioether excretion of smokers

Mutagens are present in large quantities in the urine of cigarette smokers, thus, their urothelial cells may represent a possible target for absorbed and excreted mutagens. Our aim is to validate the micronucleus (MN) test in exfoliated urothelial cells obtained from urine samples of cigarette smokers. The urinary thioether (UT) test is also carried out on the same individuals in order to find out whether there is any correlation between these two end-points. The mean (±SE) MN frequency and UT determination is 1.93 (±0.11)% and 9.71 (±1.61) mmol SH/mol creatinine for 23 smokers, and 0.66 (±0.05)% and 4.20 (±0.56) mmol SH/mol creatinine for 20 nonsmokers. Our results show a higher frequency of micronucleated cells ( p<0.001) and higher excretion of UT's ( p<0.05) in smokers as compared to nonsmokers. Concentrations of UTs and MN frequencies increased with tobacco consumption. The MN frequencies showed only a marginal increase, not significant ( p>0.05), after passive smoking compared to nonsmoking values. There was no significant correlation between MN frequencies and UTs, either in smokers ( r = 0.164, p > 0.05) or in nonsmokers ( r = −0.018, p > 0.05). Our data demonstrate tobacco-induced chromosome damage in bladder tissue consistent with increased risk of cancer at this site among smokers.

Technical aspects of automatic micronucleus analysis in rodent bone marrow assays

The mouse bone marrow micronucleus assay is an in vivo test commonly used in the pharmaceutical industry to evaluate the genotoxic potential of new compounds. The test detects agent-induced chromosomal damage or damage of the mitotic spindle apparatus. In this paper the state-of-the-art in automated rodent micronucleus evaluation using computerized image analysis in combination with high-quality slides obtained by the cellulose column fractionation technique is reviewed. The latter allows the effective removal of nucleated cells from rodent bone marrow. It has been found that automatic micronucleus scoring with the Leitz MIAC image analyzer is substantially faster than labor-intensive manual analysis. Automatic scoring can be performed overnight for up to 16 slides. We have been successfully using automatic micronucleus analysis for the testing of new pharmaceutical drugs for more than 3 years.

Cytogenetic monitoring of fishermen with environmental mercury exposure

Due to high mercury levels in many Mediterranean aquatic organisms, people who live in this area and consume large amounts of seafood are exposed to a toxicological hazard. A group of 51 fishermen exposed to mercury through eating contaminated seafood from the northern Tyrrhenian Sea underwent cytogenetic monitoring. This work is part of a research project consisting of the evaluation of micronuclei (MN), chromosomal aberrations (CA) and sister-chromatid exchanges (SCE) in peripheral blood lymphocytes. Here we present data on mercury levels in blood and on micronucleus frequencies in peripheral blood lymphocytes of fishermen. The range of mercury concentrations in blood was 10.08–304.11 ng/g fresh weight, the average was 88.97±54.09 ng/g. Micronucleus frequency was defined with at least 2000 binucleated cells scored for each person; the average was 8.74 ± 2.56 expressed on 1000 binucleated cells. A statistical correlation was found between MN frequency and total mercury concentration in blood ( p = 0.00041, r = 0.674), as well as between MN frequency and age ( p = 0.017). No other parameters taken into account correlated with MN frequency.