Sister Chromatid Exchanges In Lymphocytes Research Articles

Survival analysis and associated factors of highgrade glioma patients

High-grade gliomas are the most common primary brain tumors in adults, and they usually have a quick fatal course. Average survival is 18 months, mainly, because of tumor resistance to Stupp protocol. To determine high-grade glioma patient survival and the effect of persuasion variables on survival. We conducted a longitudinal descriptive study in which 80 untreated recently diagnosed high-grade glioma patients participated. A survey was conducted regarding their exposure to some risk factors, degree of genetic instability in peripheral blood using micronucleus quantification on binuclear lymphocytes, micronuclei in reticulocytes and sister-chromatid exchanges in lymphocytes. In the statistical analysis, this study constructed life tables, used the Kaplan-Meier, and the log-rank test, and in the multivariate analysis, a Cox proportional hazards model was constructed. Eighty patients' clinical, demographic and lifestyle characteristics were analyzed, as well as their survival rates and the average survival time is 784 days (interquartile range: 928). Factors like age, exposure at work to polycyclic hydrocarbons and the number of sister-chromatid exchanges in lymphocytes in the first sampling was significantly survivalrelated in the multivariate analysis. We determined that only three of the analyzed variables have an important effect on survival time when it comes to high-grade glioma patients.

Safety assessment of high fructose corn syrup and fructose used as sweeteners in foods

High Fructose Corn Syrup (HFCS) and Fructose (FR) are widely used sweeteners in many foods and beverages. This study aimed at investigating the cytotoxic effects of HFCS (5%–30%) and FR (62.5–2000 μg/mL) using MTT assay in Human Hepatocellular Carcinoma (HepG2) cells, and genotoxic effects of using Chromosome Aberrations (CAs), Sister Chromatid Exchanges (SCEs), Micronuclei (MN) and comet assays in human lymphocytes. HFCS significantly reduced the cell viability in HepG2 cells at between 7.5% and 30% for 24 and 48 h. 30% HFCS caused a very significant toxic effect. FR had a cytotoxic effect in HepG2 cells at all treatments. However, as fructose concentration decreased, the cell viability decreased. HFCS (10%–20%) and FR (250–2000 μg/mL) decreased the mitotic index at higher concentrations. IC50 value was found to be a 15% for 48 h. IC50 value of FR was detected as 62.5 μg/mL for 24 h and 48 h. HFCS significantly increased CAs frequency at 15% and 20%. FR significantly increased the frequency of CAs at 250, 1000, and 2000 μg/mL for 48 h. Both sweeteners increased the frequency of SCEs at all concentrations. HFCS (15% and 20%) and FR (250, 1000, and 2000 μg/mL) induced MN frequency at higher concentrations. HFCS caused DNA damage in comet assay at 10% −30%. FR increased tail intensity and moment at 125-2000 μg/mL and tail length at 62.5, 250 and 500 μg/mL. Therefore, HFCS and FR are clearly seen to be cytotoxic and genotoxic, especially at higher concentrations.

Evaluation of sister chromatid exchange in patients with breast cancer in relation to clinical stage

High levels of sister chromtid exchanges (SCE) in patients with breast caner reflects a genomic instability that may be operative in carcinogenesis.The frequency of sister chromatid exchanges in peripheral blood lymphocytes was analyzed in patients with breast cancer in relation to clinical stage in 12 stage II and 5 Stage IV untreated breast cancer patients.Moreover,SCE baseline values in patients were compared with a control group of 12 healthy women. A significant difference emerged between patients and control (P<0.01).SCE increased significantly in stage IV breast cancer patients compared with those patients of stage II (P<0.05).The results reveal that SCE frequency increases with the progression of clinical stage of breast cancer.

Evaluation the Effect of Topiramate on the Induction Genotoxicity in Obesity Patients

Topiramate ( sulfamate - substituted monosaccharide) a weight loss drug used a pharmacotherapeutic agent for obesity , a study was performed to evaluate the effect of the topiramate to induce chromosome aberrations (CA) and sister chromatid exchange (SCE) in lymphocytes of obesity patients . CA and SCE, a sensitive measure of chromosome damage , were counted in peripheral blood lymphocytes from 32 obesity patients treated with topiramate dose ( 6 months with 81mg/day , 12 months with 129 mg/day) and 16 healthy person as control group who had never received topiramate and other drugs during the period of the study. All of the treated patients with topiramate ,have cells with CA and abnormal SCE frequencies, in analysis ,obesity patients, was significantly increased CA in 129mg/day and 81mg/day topiramate dose compared with control ( 4.08±1.51 and 3.56±1.21 ) respectively, vs (1.40± 0.81),(P<0.01).Furthermore, a significantly higher SCE/Cell frequency (10.42 ±0.75and 8.75±0.38) in treated obesity patients with 129 mg/day ,81mg/day dose respectively comparison with their control group (5.91±0.31), (P<0.001).
 The chromosome damage and genotoxics are related to the daily dose and may be determined by the duration of treatment .We conclude the patients treatment with topiramate may be associated with genetic toxicity according to byproducts of drug metabolism.

HPRT gene mutation, sister chromatid exchange and comet assay in peripheral lymphocytes of radiation laborers at Al-Amal Cancer Hospital in Baghdad

A Study performed on 30 Iraqi radiation Labors had been exposed tо a low dose tо ionizing radiation at Al-Amal Cancer Hospital in Baghdad the use of three genetic endpoints. Covered 12 females and 18 males between the aged tо (22-57) years. In addition to 20 Healthy individuals from the population, dwelling Baghdad, covered, 7 females and 13 males, aged (19 - 55) years which are non-smokers, non- alcoholic. The cytogenetic analysis, including, HPRT gene mutation¸ comet assay and SCE have been carried out on peripheral blood lymphocytes of labors and control groups. The HPRT gene mutation assay showed a significant increase (p<0.05) in the radiation labors. There were found a significant increase (p<0.05) in comet tail length and tail moment values in thе human lymphocyte in these radiation Labors compared with thе control group. Also the SCE in human lymphocyte for radiation Laborers was significantly (p<0.05) higher than in a control group. Results obtained confirmed the cytogenetic analysis; including, HPRT gene mutation¸ comet assay and SCE are useful as biodosimetric markers for the detection of human exposure to low doses of ionizing radiation. It reflects the simultaneous exposure and actual levels of DNA damage present in radiological laborers' peripheral blood leukocytes by detecting temporary DNA damage and / or repair activity.

In vitro effects of Sunset Yellow on Chromosomal Damage and Sister Chromatid Exchanges in Human Peripheral Lymphocytes

Sunset Yellow (SY) is an organic azo dye that is used extensively as a coloring agent in many industries, such as cosmetics, pharmaceuticals ,and foodstuffs. Many studies have conflicting results about the genotoxicity effect of SY. Thus, the purpose of this study was to provide additional data concerning SY genotoxicity in human lymphocytes by using chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) assay. Four concentrations of Sunset Yellow (1, 5, 20 ,and 50 mg/ml) were used on human lymphocyte cultures. Positive and negative controls were mitomycin C and distilled water, respectively. Compared to the control, SY caused a significant increase in CAs and SCEs frequencies at all concentrations. A total of five types of CAs were observed, such as gaps, fragments, RCF, stickiness,and polyploidy. According to the present results, high concentrations of SY are genotoxic in vitro to cultured human lymphocytes. To determine its full genotoxicity potential, SY should be tested in other test systems.

Environmental Tobacco Smoke in Occupational Settings: Effect and Susceptibility Biomarkers in Workers From Lisbon Restaurants and Bars

Environmental tobacco smoke (ETS) has been recognized as a major health hazard by environmental and public health authorities worldwide. In Portugal, smoke-free laws are in force for some years, banning smoking in most indoor public spaces. However, in hospitality venues such as restaurants and bars, owners can still choose between a total smoke-free policy or a partial smoking restriction with designated smoking areas, if adequate reinforced ventilation systems are implemented. Despite that, a previous study showed that workers remained continuously exposed to higher ETS pollution in Lisbon restaurants and bars where smoking was still allowed, comparatively to total smoke-free venues. This was assessed by measurements of indoor PM2.5 and urinary cotinine, a biomarkers of tobacco smoke exposure, demonstrating that partial smoking restrictions do not effectively protect workers from ETS. The aim of the present work was to characterize effect and susceptibility biomarkers in non-smokers from those hospitality venues occupationally exposed to ETS comparatively to non-exposed ones. A group of smokers was also included for comparison. The sister chromatid exchange (SCE), micronucleus (MN) and comet assays in whole peripheral blood lymphocytes (PBLs) and the micronucleus assay in exfoliated buccal cells, were used as biomarkers of genotoxicity. Furthermore, a comet assay after ex vivo challenge of leukocytes with an alkylating agent, ethyl methanesulfonate (EMS), was used to analyze the repair capacity of those cells. Genetic polymorphisms in genes associated with metabolism and DNA repair were also included. The results showed no clear association between occupational exposure to ETS and the induction of genotoxicity. Interestingly, the leukocytes from non-smoking ETS-exposed individuals displayed lower DNA damage levels in response to the ex vivo EMS challenge, in comparison to those from non-exposed workers, suggesting a possible adaptive response. The contribution of individual susceptibility to the effect biomarkers studied was unclear, deserving further investigation.

Genotoxicity linked to occupational exposure in uranium mine workers: Granzyme B and apoptotic changes.

Uranium mining and processing are an ancient occupation, recognized as being grueling and accountable for injury and disease. Uranium (U) is a radioactive heavy metal used in many industrial applications. It increases the micronuclei frequencies as well as chromosomal aberration and sister chromatid exchange in peripheral blood lymphocytes. Granzyme B and perforin are stored inside the leukocytes in secretory granules. These proteins are released outside the cells by a cell-to-cell contact under specific conditions for inducing apoptosis. So, this study investigated the potential health hazards with prominence on the biological effects of radiation exposure. A cross-sectional analytic research was conducted on Egyptian male mining field workers. Leucocytes' genotoxicity was evaluated using DNA fragmentation assay and comet assay. Furthermore, flow cytometric analysis of Granzyme B protein was done. A significant increase in dead cells after dual acridine orange/ethidium bromide (AO/EB) fluorescent staining in radiation-exposed groups was noticed compared to control groups. Moreover, a significant increase in the fragmented DNA was evident in exposed groups relative to the control one. Granzyme B protein levels showed a significant increase concerning control. A wide variety of adverse human health risks are considered a potential risk to Egyptian uranium miners. For employers working in both mining and processing fields, the most common molecular shift highlighted was the leucocyte damage in blood samples. To preserve the health of all employees, health education and administration of effective hazard management procedures are necessary.

Aldehyde degradation deficiency (ADD) syndrome: discovery of a novel fanconi anemia-like inherited BMF syndrome due to combined ADH5/ALDH2 deficiency

We have recently described the identification of a novel inherited bone marrow failure syndrome. The first set of patients was diagnosed through the exome analysis of cells from Japanese patients with hypoplastic anemia, which have been deposited to the JCRB cell bank for quite some time previously. Originally, these cases were diagnosed with a novel disorder based on increased levels of sister chromatid exchanges in lymphocytes; however, causative genes were clarified only after applying the recently developed next-generation sequencing technology. Aldehyde degradation deficiency syndrome (ADDS) is caused by combined defects in two genes, ADH5 and ALDH2, which are both critical for degrading endogenously generated formaldehyde. Formaldehyde is highly reactive and toxic to biological molecules including DNA, and its endogenous generation in the absence of the degradation system results in DNA damage that overwhelms the DNA repair capacity, leading to the development of BMF with loss of hematopoietic stem cells and progression to MDS/leukemia. In this short review, we would like to summarize what is known today about ADDS for a wide readership of hematology clinicians in Japan.

Genotoxic properties of Betonica officinalis, Gratiola officinalis, Vincetoxicum luteum and Vincetoxicum hirundinaria extracts

Genotoxicity of B. officinalis, G. officinalis, V. luteum and V. hirundinaria extracts, which demonstrated strong antioxidant capacity, was tested using chromosome aberration, sister chromatid exchange (SCE), cytokinesis-block micronucleus and alkaline single-cell gel electrophoresis (comet) assays in human lymphocytes in vitro and Ames Salmonella/microsome test. All tested extracts were not mutagenic in S. typhimurium strains TA98 and TA100 with and without metabolic activation and did not induce chromosome aberrations in human lymphocytes in vitro. Extract from G. officinalis was the only one, which induced significant increase in micronuclei, indicating possible aneugenic effect. All investigated plant extracts induced DNA damage evaluated by the comet assay, while B. officinalis and V. luteum extracts induced slight increase in SCE values. The determined variation in response might be due to the plant extract tested and donor susceptibility.

Vitamin B12 protects against DNA damage induced by hydrochlorothiazide

DNA damage induced by hydrochlorothiazide was previously reported in cultured human lymphocytes. In this study, we aimed to investigate the harmful effects of hydrochlorothiazide on DNA by measuring the spontaneous frequency of sister chromatid exchanges (SCEs) in cultured human lymphocytes. We also aimed to investigate the possible protection of that damage by vitamin B12. The results showed that hydrochlorothiazide (5 µg/mL) significantly increased the frequency of sister chromatid exchanges (P < 0.001) in human lymphocytes in comparison with control. Additionally, the frequency of hydrochlorothiazide-induced SCEs was significantly decreased by co-treatment with vitamin B12 at concentration of 13.5 µg/mL (P < 0.001). In conclusion, hydrochlorothiazide is genotoxic to human lymphocytes and its toxicity is reduced by vitamin B12.

The Effects of Aflatoxin B1 on Chromosome Aberrations and Sister Chromatid Exchanges in Human Lymphocytes

Aflatoxin B1 (AFB1) is a ubiquitous mycotoxin produced by toxicogenic Aspergillus species. AFB1 has been reported to cause serious adverse health effects, such as cancers and abnormal development and reproduction, in animals and humans. The aim of this study was to investigate the ability of aflatoxin B1 (AFB1) to induce chromosome aberrations (CA) and sister chromatid exchanges (SCE) in human lymphocytes. AFB1 exposure significantly increased the number of CA and the frequency of SCE when compared with the control group. This significant increase in CAs as well as SCE may be attributed to the fact that AFB1 can induce genotoxicity through DNA damage. Thus, the present study indicates that AFB1 was genotoxic in human lymphocytes.

Mutagenic and genotoxic effects of Anilofos with micronucleus, chromosome aberrations, sister chromatid exchanges and Ames test.

We aimed to evaluate the mutagenic effect of Anilofos, organophosphate pesticide, by using Ames/Salmonella/microsome test. Its cytotoxic and genotoxic effects were also determined by chromosome aberration (CA), sister chromatid exchange (SCE) and micronucleus (MN) test in human peripheral blood lymphocytes. In the Ames test, five different concentrations of Anilofos were examined on TA97, TA98, TA100 and TA102 strains in the absence and presence of S9 fraction. According to the results all concentrations of this pesticide have not shown any mutagenic activity on TA97, TA100 and TA102 strains in the absence and presence of S9 fraction. But, 10, 100 and 1000µg/plate concentrations of Anilofos were determined to be mutagenic on TA98 strain without S9 fraction. Lymphocytes were treated with various concentrations (25, 50, 100 and 200µg/ml) of Anilofos for 24 and 48h. The results of the assays showed that Anilofos did not induce SCE frequency, replication index and MN formation at all concentrations for both treatment periods. Anilofos significantly increased CA frequency at 100 and 200µg/ml concentrations at 24h treatment periods and at 50, 100 and 200µg/ml concentrations in 48h treatment periods. Additionally, it was determined that this pesticide decreased mitotic index and nuclear division index significantly. It was concluded that Anilofos has genotoxic and cytotoxic effects in human peripheral lymphocytes.

Early detection of lung cancer potential among Egyptian wood workers.

Wood dust is known to be a human carcinogen, with a considerable risk of lung cancer. The increased cancer risk is likely induced through its genotoxic effects resulting from oxidative DNA damage. This study aimed at assessing the genotoxicity of wood dust and demonstrating the role of sputum PCR as a screening tool for early prediction of lung cancer among wood workers. The study was carried out in the carpentry section of a modernized factory involved with the manufacture of wooden furniture in Greater Cairo, Egypt. Environmental assessment of respirable wood dust concentrations was done. Frequency of chromosomal aberrations (CA%) and sister chromatid exchanges (SCE%) in peripheral blood lymphocytes (PBL) was assessed and comet assays were performed in samples from among the study population (n=86). Levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes were measured. The polymerase chain reaction (PCR) was used to study hypermethylation of p16 and ̸or O6-methylguanine-DNA methyltransferase (MGMT) gene promoters in sputum DNA. The concentrations of respirable wood dust exceeded the Egyptian and international permissible limits with highest levels generated by sawing operations. Laboratory investigations revealed statistically significantly higher frequencies of CA and SCE as well as increased comet tail length associated with significant decrement in the levels of SOD and GPx among exposed group. A statistically significant elevation in the extent of hypermethylation was detected for the p16 and MGMT gene promoters in the sputum DNA of studied wood workers. The study results support the conclusion that prolonged unprotected occupational exposure to wood dust is associated with possible genotoxicity and oxidative stress that might raise the risk for carcinogenesis including lung cancer.

Influence of Radiotherapy on Frequency of Sister Chromatid Exchange, Micronuclei and Binuclear Cells in Breast Cancer Patients

The aim of this study was to evaluate any cytogenetic change in sister chromatid exchange (SCE), micronuclei (MN) and binuclear cell (BNC) of peripheral blood lymphocytes in breast cancer patients treated with postoperative radiation therapy (RT). Frequency of the SCE, MN and BNC were examined in 22 breast cancer patients received RT and 10 healthy individuals. All parameters were measured before (RT-a), at the completion of (RT-b) and three months after the completion of (RT-c) RT. A significant difference emerged in SCE (p=0.008) and MN (p=0.004) between RT-a and control groups. There was not any statistically significant difference in the SCE frequencies between RT-b and RT-c measurements. The frequencies of MN were also significantly higher in RT-b (p=0.005) and RT-c (p=0.005) than in control group. MN levels decreased to pre-RT levels three months after completion of treatment. Increasing MN and SCE frequencies following radiotherapy is an expected situation. Decrease in MN frequency at 3-month after the completion of RT suggests that expected repair continues. Persistent SCE at the same period suggests that recovery in SCE has not completed yet and a longer period of time is needed.

Baseline frequency of chromosomal aberrations and sister chromatid exchanges in peripheral blood lymphocytes of healthy individuals living in Turin (North-Western Italy): assessment of the effects of age, sex and GSTs gene polymorphisms on the levels of genomic damage

Background: The increased exposure to environmental pollutants has led to the awareness of the necessity for constant monitoring of human populations, especially those living in urban areas.Aim: This study evaluated the background levels of genomic damage in a sample of healthy subjects living in the urban area of Turin (Italy). The association between DNA damage with age, sex and GSTs polymorphisms was assessed.Subjects and methods: One hundred and one individuals were randomly sampled. Sister Chromatid Exchanges (SCEs) and Chromosomal Aberrations (CAs) assays, as well as genotyping of GSTT1 and GSTM1 genes, were performed.Results: Mean values of SCEs and CAs were 5.137 ± 0.166 and 0.018 ± 0.002, respectively. Results showed age and gender associated with higher frequencies of these two cytogenetic markers. The eldest subjects (51–65 years) showed significantly higher levels of genomic damage than younger individuals. GSTs polymorphisms did not appear to significantly influence the frequencies of either markers.Conclusion: The CAs background frequency observed in this study is one of the highest reported among European populations. Turin is one of the most polluted cities in Europe in terms of air fine PM10 and ozone and the clastogenic potential of these pollutants may explain the high frequencies of chromosomal rearrangements reported here.

GENOTOXICITY OF FORMALDEHYDE IN PERIPHERAL BLOOD LYMPHOCYTES AMONG PATHOLOGY LABORATORY WORKERS

Introduction: Formaldehyde (FA) is a chemical, traditionally used in pathology and anatomy laboratories as a tissue preservative. Many studies clearly indicated that FA can induce genotoxic effects in peripheral blood lymphocytes. Aim of work: to evaluate the genotoxic effects of formaldehyde among medical and paramedical personnel in The Histopathology Laboratory. Materials and Methods: The study was conducted in histopathology laboratory including 30 workers occupationally exposed to formaldehyde and 29 persons from other lab in kasr Al Aini hospital matching the exposed group for age, sex and socioeconomic status with no history of occupational exposure to formaldehyde. A questionnaire was done including inquiries about age, sex, occupational history and special habits. All participants were subjected to the following laboratory investigations: measuring DNA protein crosslink (DPC), sister chromatid exchange (SCE) and micronucleus (Mn) frequency in peripheral blood lymphocytes. Environmental monitoring of the work place was done to measure the level of FA at different place in the pathology lab. Results: This study showed statistically significant increase of DPC with significant increase in sister chromatid exchange (SCE) and micronucleus MN in peripheral blood lymphocytes. Conclusion: The studied group was exposed to formaldehyde level above the exposure limits recommended by NIOSH, ACGIH and OSHA with adverse health effects in the form of increase in DPC, SCE and Mn as genotoxicity biomarkers. These genotoxicity biomarkers are considered to play an important role in the carcinogenesis of FA.

In vitro and in vivo effects of melatonin on sister chromatid exchange in human blood lymphocytes exposed to hypoxia

Objective: Many studies have shown that melatonin (MLT) has an anti-genotoxic effect in various tissues and cell lines. The aim of this study was to investigate the anti-genotoxic effect of MLT on normal human peripheral lymphocytes by assessing sister chromatid exchange (SCE) in vitro and in vivo. Materials and methods: Cells were treated with 50 and 200 μM of MLT. The human volunteers (n = 20) for the in vivo study were administered a single dose of 3 mg MLT daily for 2 weeks. After sufficient time for its clearance, 1.5 mg of MLT daily was then administered to the same volunteers at same the period. Results: Our results demonstrated the anti-genotoxic effect of MLT in human blood lymphocyte in vitro and in vivo. In vitro, hypoxia increased the SCE frequency compared to the control and both doses of MLT significantly decreased the SCE frequency in the hypoxic cells (p < 0.001). In vivo, oral administration of 3 mg MLT significantly increased the frequency of SCE, yet a small increase of SCE by hypoxia was found. Oral administration of 1.5 mg MLT showed no DNA damage but it had an anti-genotoxic effect. Discussion and conclusion: MLT may prove useful for reducing the genotoxic effects of hypoxia in peripheral lymphocytes and suggest its possible role for ischemic diseases.

Increased sister chromatid exchange in peripheral blood lymphocytes from humans exposed to pesticide: evidence based on a meta-analysis.

Sister chromatid exchange (SCE) in human peripheral blood lymphocytes is one of the most extensively studied biomarkers employed to evaluate genetic damage subsequent to pesticide exposure. To estimate the pooled levels of SCE in human peripheral blood lymphocytes among population exposed to pesticide. Meta-analysis on the association between SCE frequency and pesticide exposure was performed with STATA 10.0 software package and Review Manager 5.0.24 in this study. The overall means of SCE were 7.88 [95% confidence intervals (95%CI): 6.71-9.04] for exposure group and 6.05 (95%CI: 5.13-6.95) for controls, respectively. There was statistically significant difference in the SCE frequency in human peripheral blood lymphocytes between pesticide-exposed groups and control groups, and the summary estimate of weighted mean difference was 1.69 (95%CI: 1.01-2.38). We also observed that pesticide-exposed population had significantly higher SCE frequency than control groups among smokers, nonsmokers, pesticide applicator, pesticide producer, other exposure population and Asian population in stratified analyses. Data indicate that the SCE frequency in human peripheral blood lymphocytes might be an indicator of early genetic effects for pesticide-exposed populations.

Assessment of genotoxicity associated with Behcet’s disease using sister-chromatid exchange assay: vitamin E versus mitomycin C

Behcet's disease (BD) is a multisystemic chronic inflammatory disorder that presents throughout the world with high frequency in Turkey and Middle East. BD has been shown to be associated with genotoxicity as patients with the disease have demonstrated high rates of sister chromatid exchange (SCE) and oxidative DNA damage. In this study, we examined the effect of vitamin E, which is known for its strong antioxidant activity, on the rate of SCE in cultured lymphocytes obtained from BD patients. In addition, the susceptibility of patient lymphocytes to the mutagenic agent mitomycin C (MMC) was also investigated. The results showed significant elevation in the rate of SCE in lymphocytes obtained from patients compared to those from healthy subjects (P<0.01). Treatment with vitamin E normalized the elevated rate of SCE to a comparable level observed in the control group (P<0.01). Finally, treatment of cultures with MMC significantly increased the rate of SCE in the lymphocytes of both patients and controls (P<0.001). The magnitude of change in the rate of SCE induced by MMC was equivalent in both groups. This result suggests similar sensitivity of BD lymphocytes and control ones to MMC. In conclusion, genotoxicity associated with BD can be overcome by treatment with vitamin E. Lymphocytes of BD have normal sensitivity to the mutagenic agent MMC.