Chromosome Aberrations In Lymphocytes Research Articles

Analysis of Sheep Lymphocyte Chromosomal Aberrations after Exposition to Chlortetracycline

Tetracyclines are broad spectrum antibiotics and one type of various their compounds—chlortetracycline has been successfully used for our cytogenetic studies. We have selected for these studies the chromosomal assay because it is wellknown cytogenetic biomarker, which has been used to assess DNA damage at the chromosomal level. We analyzed the chromosomal aberrations and mitotic index in peripheral lymphocytes of sheep exposed by chlortetracycline chloride in pure tap water. To the food of the experimental group of animals (à n = 6) were added also 0.35 gof preparation Aureovit12 C80 plv. a. u. v. per kg b. w. and day (i.e. 168 mg of chlortetracycline hydrochloride/kg b. w.) daily in food. The frequencies of aberrant cells (ABC) in the experimental and control groups of sheep were stated to differ significantly (P = 0.001). In experimental group, chromatid breaks were the dominant type of chromosomal aberrations. No statistical differences in mitotic index values were found in the both groups (P > 0.05). Increased frequencies of chromosome aberrations in peripheral lymphocytes of sheep exposed by chlortetracycline in food, suggested a potential hazard which needs the attention from the viewpoint of human and animal health. This knowledge is useful for all, for the human and veterinary medicine, as well as for the aquaculture. Many of these chlortetracycline substances for their environmental persistence and chemical unstability are present in the environment for various periods, and as a result, they are responsible for several effects on human and animal health through food chain.

Генетические и цитогенетические предикторы радиочувствительности хромосом человека

We studied association between the frequencies of gamma-induced (1 Gy in vitro) chromosome aberrations in blood lymphocytes and polymorphism of 45 repair candidate genes, detoxification and oxidative stress genes (53 sites) for 99 healthy volunteers. The levels of chromosome-type aberrations correlated with carriage of the minor alleles of the genes OGG1 Ser326Cys, ABCB1 Ile1145 = and NQO1 Pro187Ser (p = 0.0002). We have shown that all the revealed genetic associations were less effective in predicting chromosomal radiosensitivity as compared to the correlations between spontaneous and gamma-induced aberrations (p = 1.0 x 10(-6)). The addition of genetic markers to cytogenetic predictors improved the predictive accuracy for chromosomal radiosensitivity with the multiple correlation coefficient reaching R = 0.58 (p = 3.1 x 10(-8)). Thereby we were able to explain more than 30% of the population variability in chromosomal radiosensitivity.

Effect of Hypogymnia physodes Extracts and their Depsidones on Micronucleus Distribution in Human Lymphocytes

Three lichen depsidones, physodalic acid (1), physodic acid (2), and 3-hydroxy physodic acid (3), were isolated from Hypogymnia physodes diethyl ether extract using column chromatography, and their structures determined by comparing their UV, 1H and 13C NMR spectroscopic and MS data with those given in the literature, as well as with data computed by CHEM draw ultra 11 software. The contents of 1, 2 and 3 were determined in the methanol (ME), acetone (AE), and diethyl ether (EE) extracts using reversed-phase high performance liquid chromatography with photodiode array detection. The extracts, isolated depsidones 1-3 and EE fraction F23 (consisting of 90% 2 and 3, in the ratio 5.5: 1) were evaluated for their in vitro effects on chromosome aberrations in peripheral human lymphocytes using the cytochalasin-B blocked micronucleus (CBMN) assay in doses of 1 microg/mL and 2 microg/mL of final culture solution. The frequency of MN was scored in binucleated cells, and nuclear proliferation index was calculated. It was found that 1, 2, 3, F23, and EE at 1.0 microg/mL exerted a beneficial effect on lymphocyte cells giving a significant decrease of the frequency of MN in comparison with the positive control Amifostin WR-2721.Among the tested depsidones at a concentration of 1 microg/mL, 3 exhibited the most prominent effect decreasing the frequency of MN by 30.3%, followed by 2 (28.2%) and 1 (22.0%). The extracts were less effective than the isolated depsidones.

RBE of thermal neutrons for induction of chromosome aberrations in human lymphocytes

The induction of chromosome aberrations in human lymphocytes irradiated in vitro with slow neutrons was examined to assess the maximum low-dose RBE (RBE(M)) relative to (60)Co γ-rays. For the blood irradiations, cold neutron beam available at the prompt gamma activation analysis facility at the Munich research reactor FRM II was used. The given flux of cold neutrons can be converted into a thermally equivalent one. Since blood was taken from the same donor whose blood had been used for previous irradiation experiments using widely varying neutron energies, the greatest possible accuracy was available for such an estimation of the RBE(M) avoiding the inter-individual variations or differences in methodology usually associated with inter-laboratory comparisons. The magnitude of the coefficient α of the linear dose-response relationship (α=0.400±0.018Gy(-1)) and the derived RBE(M) of 36.4±13.3 obtained for the production of dicentrics by thermal neutrons confirm our earlier observations of a strong decrease in α and RBE(M) with decreasing neutron energy lower than 0.385MeV (RBE(M)=94.4±38.9). The magnitude of the presently estimated RBE(M) of thermal neutrons is-with some restrictions-not significantly different to previously reported RBE(M) values of two laboratories.

Assessment of Chromosomal Aberrations and Micronuclei in Peripheral Lymphocytes from Tunisian Hospital Workers Exposed to Ionizing Radiation

Epidemiological studies suggest that cytogenetic biomarkers, such as micronuclei (MN) in peripheral blood lymphocytes may predict cancer risk because they indicate genomic instability. The objective of the present study was to evaluate the frequencies of MN and chromosome aberrations (CA) in peripheral blood lymphocytes of hospital workers exposed to ionizing radiation and healthy subjects. The study was conducted using peripheral blood lymphocytes from 30 workers from the radiology department and 30 from the cardiology department. This study included 27 healthy age- and sex-matched individuals as the control group. The assessment of chromosomal damage was carried out by the use of CA and micronucleus assays in peripheral lymphocytes. Our results show that CA and micronucleus frequencies were significantly higher among the exposed groups when compared to controls. Our finding of significant increase of CA and MN frequencies in peripheral lymphocytes in exposed workers indicates a potential cytogenetic hazard due to this exposure. The enhanced chromosomal damage of subjects exposed to genotoxic agents emphasizes the need to develop safety programs.

Correlations Between DNA Polymorphism and Frequencies of Gamma-Radiation Induced and Spontaneous Cytogenetic Damage

With the aim of developing genetic tests for elevated and reduced radiation sensitivity, the authors studied the correlations between various genotypes and frequencies of spontaneous and radiation-induced chromosome aberrations in human lymphocytes. Cytogenetic analysis and genotyping (19 sites of detoxification and DNA repair genes) were carried out for a group of cleanup workers of the Chernobyl nuclear power plant accident (83 people) and for a uniform control group of volunteers (97 people). In both cases, the frequencies of chromosome type aberrations were higher in carriers of minor alleles of gene XPD [sites T2251G (Lys751Gln) and G862A (Asp312Asn)] and the "positive" genotypes GSTM1/GSTT1. The polymorphism of these genes did not affect the frequency of aberrations induced by gamma radiation in the control group (1 Gy in vitro), which was associated with genotypes by loci OGG1, XRCC1, and CYP1A1. Thus, in the control group, spontaneous and in vitro induced cytogenetic effects are associated with different groups of polymorphic genes. In the cleanup workers group (irradiated in vivo), the elevated frequency of aberrations was observed in the carriers of those genotypes that typically have a higher level of spontaneous (but not in vitro induced) cytogenetic damage in the control. The genotype "minor XPD + insertion GST," having an estimated incidence of 64% in central Russia, was characterized and found to be strongly associated with an elevated frequency of chromosome type aberrations following irradiation in vivo (OR = 6.9; p = 0.008).

Chemical Composition of Currant Seed Extracts and Their Protective Effect on Human Lymphocytes DNA

On the basis of LC/UV/MS analysis, 35 compounds from the extracts of seeds of black, red, and white currants (2 cultivars of each) were identified. Black currants cultivars contained protocatechuic acid and p-hydroxybenzoic acid, and traces of nitril containing phenolic acids. The presence of synapoyl glucoside was characteristic for cv. Malling Jewel. Sesquiterpenoid glycosides and carboxymethylindol glycosides were present mainly in white and red currant cultivars. Blackcurrant seeds contained higher amounts of flavonoids, especially rutin, isoquercetin, and taxifolin. The currant seed extracts were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (CBMN) assay. The frequency of MN was scored in binucleated cells, and the cultivars of black currants showed the best antioxidant potential. At a concentration of only 0.17 mg/mL, extract of the seed cv. Malling Jewel effected a decrease in the frequency of MN of 60% compared with control cell cultures. Our results provide evidence of protective effects of currant seed extracts and isolated pure compounds on cytogenetic damages in human lymphocytes. Thus, currant seed extracts could exert beneficial effects in quite a few diseases, for many of the biological actions have been attributed to their antioxidant properties.

High frequency of chromosome aberrations observed in lymphocytes in postmenopausal obese women

Epidemiological studies indicate that obesity is associated with an increased risk of 20-25% with several types of cancer. The frequency of chromosome aberrations was evaluated in lymphocytes from postmenopausal obese and non-obese women. Twenty obese and 20 non-obese women, all post-menopause, were recruited. The groups were matched according to age (± 5 years) and place of origin. After signing the consent form, women were interviewed using a structured questionnaire, and a blood sample (5 ml) was drawn into vacutainer tubes. From each sample, lymphocyte cell cultures were established with and without mitomycin C (challenge assay). Afterwards, the frequency of chromosome aberrations were recorded for each group and treatment. Data were analyzed using the statistical program SPSS, v. 14.0. Obese women had a higher frequency of chromosome aberrations when compared with non-obese women. After exposing the cell cultures to mitomycin C, obese women presented an increase in the number of total chromosome aberrations in comparison to non-obese women (3.7± 0.6 vs. 2.70±0.6; p=0.001). The higher frequency of chromosome aberrations in lymphocytes from postmenopausal obese women compared to non-obese women suggested differences in the DNA repair capacity. This may indicate an association between genomic instability and the higher incidence of cancer in this population.

Radiation Exposure—Do Urologists Take it Seriously in Turkey?

A questionnaire was administered to urologists to evaluate attitudes and behaviors about protection from radiation exposure during fluoroscopy guided endourological procedures. The questionnaire was e-mailed to 1,482 urologists, including urology residents, specialists and urologists holding all levels of academic degrees, between May and June 2011. The questionnaire administered to study participants was composed of demographic questions, and questions on radiation exposure frequency, and the use of dosimeters and flexible protective clothes. If a respondent reported not using dosimeters or protective clothes, additional questions asked for the reason. Of the 1,482 questionnaires 394 (26.58%) were returned, of which 363 had completed answers. A total of 307 physicians (84.58%) were exposed to ionizing radiation, of whom 79.61% stated that they perform percutaneous nephrolithotomy at the clinic. Fluoroscopy guidance was the initial choice of 96.19% of urologists during percutaneous nephrolithotomy. Despite the common use of lead aprons (75.24%) most urologists did not use dosimeters (73.94%), eyeglasses (76.95%) or gloves (66.67%) while 46.44% always used thyroid shields during fluoroscopy. When asked why they did not use protective clothing, the most common answers were that protective clothes are not ergonomic and not practical. Results clearly highlight the lack of use of ionizing radiation protection devices and dosimeters during commonly performed fluoroscopy guided endourological procedures among urologists in Turkey.

Estimating the effectiveness of human-cell irradiation by protons of a therapeutic beam of the joint institute for nuclear research phasotron using cytogenetic methods

The effectiveness of the impact of therapeutic proton beams in human cells with respect to the criterion of formation of chromosome aberrations in human-blood lymphocytes is estimated. The physical characteristics of radiation (proton LET at the input of the object and in the region of the modified Bragg peak) and the role of the biological factor (the differences in the radiosensitivity of nondividing cells corresponding to the irradiation of normal tissues along the proton-beam path and tumor tissues) are taken into account. The relative biological effectiveness of protons is ∼1 at the beam input of the object and ∼1.2 in the Bragg peak region. Taking into account the higher radiosensitivity of dividing cells in the G2 phase of the cell cycle, the irradiation effectiveness increases to ∼1.4.

Allelic variants of polymorphic genes associated with a higher frequency of chromosome aberrations

Genotypic associations were studied for the frequency of chromosome aberrations in human peripheral blood lymphocytes. Cytogenetic analysis (1000 metaphase plate per individual) and genotyping at 19 sites of genes involved in detoxification and DNA repair were performed in a sample of 83 Chernobyl liquidators and a matched control sample of 96 volunteers. In either sample, the frequency of chromosome aberrations was higher in carriers of the minor alleles of the XPD gene (sites 2251T > G and 862G > A) and the positive genotypes of the GSTM1-GSTT1 genes. The highest frequency of chromosome aberrations was observed in carriers of a combined genotype including at least one minor allele of the XPD sites + at least one insertion in the GSTM1-GSTT1 genes. The high-risk genotype, which had a prevalence of 64%, was strongly associated with a higher frequency of chromosome aberrations in both volunteers (OR = 6.9, P = 0.008) and Chernobyl liquidators (OR = 5.6, P = 0.002).

Integration of Pig‐a, micronucleus, chromosome aberration, and comet assay endpoints in a 28‐day rodent toxicity study with 4‐nitroquinoline‐1‐oxide

As part of the Stage III Pig-a multilaboratory validation trial, we examined the induction of CD59-negative reticulocytes and total red blood cells (RET(CD59-) and RBC(CD59-) , respectively) in male Sprague Dawley(®) rats treated with 4-nitroquinoline-1-oxide (4NQO), for 28 consecutive days by oral gavage, at doses of 1.25, 2.50, 3.75, 5.00, and 7.50 mg kg(-1) day(-1) (the high dose group was sacrificed on Day 15 due to excessive morbidity/mortality). Animals also were evaluated for: micronucleated reticulocytes (mnRET) by flow cytometry; DNA damage in peripheral blood, liver, and stomach using the Comet assay; and chromosome aberrations (CAb) in peripheral blood lymphocytes (PBL). All endpoints were analyzed at two or more timepoints where possible. Mortality, body and organ weights, food consumption, and clinical pathology also were evaluated, and demonstrated that the maximum tolerated dose was achieved at 5.00 mg kg(-1) day(-1) . The largest increases observed for the genetic toxicology endpoints (fold-increase compared to control, where significant; all at 5.00 mg kg(-1) day(-1) on Day 29) were: RET(CD59-) (21X), RBC(CD59-) (9.0X), and mnRET (2.0X). In contrast, no significant increases were observed for the CAb or Comet response, in any tissue analyzed, at any timepoint. Because 4NQO is a well known mutagen, clastogen, and carcinogen, the lack of response for these latter endpoints was unexpected. These results emphasize the extreme care that must betaken in dose and endpoint selection when incorporating genotoxicity endpoints into routine toxicity studies as has been recommended or is under consideration by various regulatory and industrial bodies.

Chromosome aberrations in peripheral blood lymphocytes of individuals living in high background radiation areas of Ramsar, Iran

In order to investigate the biological effects of exposure to low-dose radiation and to assess the dose-effect relationship in residents of high background radiation areas (HBRAs) of Ramsar, cytogenetic investigation of unstable-type aberrations was performed in 15 healthy elderly women in a HBRA of Ramsar, Talesh mahalle, and in 10 elderly women living in a nearby control area with normal background radiation. In total, 77,714 cells were analyzed; 48,819 cells in HBRA residents and 28,895 cells in controls. On average, 3,108 cells per subject were analyzed (range 1,475-5,007 cells). Significant differences were found in the frequency of dicentric plus centric rings in 100 cells (0.207 ± 0.103 vs. 0.047 ± 0.027, p < 0.0005), total chromosome-type aberrations per 100 cells (0.86 ± 0.44 vs. 0.23 ± 0.17, p < 0.0005), and chromatid-type aberrations per 100 cells (3.31 ± 2.01 vs. 1.66 ± 0.63, p = 0.01) by the Mann-Whitney U test between HBRA and the control, respectively. Using chromosomal aberrations as the main endpoint to assess the dose-effect relationship in residents of HBRAs in Ramsar, no positive correlation was found between the frequency of dicentric plus centric ring aberrations and the cumulative dose of the inhabitants estimated by direct individual dosimetry; however, obvious trends of increase with age appeared in the control group. Based on these results, individuals residing in HBRAs of Ramsar have an increased frequency of detectable abnormalities in unstable aberrations.

Persistent unstable chromosomal aberrations in lymphocytes of radiotherapy workers after 1st mitotic division

Persistent unstable chromosomal aberrations in lymphocytes of radiotherapy workers after 1st mitotic division

Blackberry Seed Extracts and Isolated Polyphenolic Compounds Showing Protective Effect on Human Lymphocytes DNA

The tentative identification of seed extracts from 3 cultivars of blackberry (blackberry seed extracts [BSEs]) constituents was performed by LC/UV/MS technique. The identified compounds belonged to ellagitannins, galic acid derivatives, and ellagic acid derivatives. Two ellagitannins, Lambertianin C and Sanguiniin H-6, and an ellagic acid derivative, 4-α-L-arabinofuranosylellagic acid, were isolated using semipreparative High-performance liquid chromatography. The structure elucidations were based on high resolution-mass spectrometry and nuclear magnetic resonance studies. The BSEs and 3 isolated pure compounds were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (MN) assay. The frequency of MN was scored in binucleated cells, and nuclear proliferation index was calculated. Among the tested extracts, the seeds of cv. Thornfree at concentration of 1 μg/mL exhibit the most prominent effect decreasing the frequency of MN by 62.4%, when compared with the controls cell cultures. Antioxidant potential of pure ellagitannins cannot explain the strong effect of BSEs. The assumption was that better antioxidant effect of BSEs result from synergistic effects of individual compounds contained in the extracts and/or some minor components possessed strong activity. PraCTICAL APPLICATION: Our results provide evidence of protective effects of BSEs and isolated pure compounds on cytogenetic damages in human lymphocytes. Thus, BSEs could exert beneficial effects in quite a few diseases, because many of the biological actions have been attributed to their antioxidant properties.

Cytogenetic effects induced by accelerated carbon ions with shielding

Our work aims to understand the effects of shielding on the induction of biological damage by heavy charged particles and to compare the shielding effects of different materials at the same LET from two aspects: the biological effectiveness including or not including secondary particles emitted at large angles and the biological effectiveness at different angles with respect to the beam direction. We designed and conducted biological experiments to determine the biological effectiveness of 200 MeV/u carbon ions after traversing different shielding materials (Lucite and aluminium). Whole blood samples, which were either attached to the shielding material (48 mm Lucite or 29 mm aluminium)or positioned at 300 cm away from it at different angles with respect to the beam axis, were exposed to carbon ion beams. For comparison, whole blood samples were exposed directly to 200 MeV/u carbon ions. Chromosomal aberrations in lymphocytes were scored. The results indicated that the biological effectiveness per unit dose was not significantly changed by 48 mm Lucite or 29 mm aluminium, and no significant differences were observed in lymphocytes attached to the target and in lymphocytes positioned at a distance of 300 cm away from the target, at 0º angle of the beam axis. However, when plotted as a function of the number of ions hitting the shielding target, the curves are separated and the shield increases the effectiveness per unit ion. The frequency of chromosomal aberrations at tilted angles behind 29 mm Al and 48 mm Lucite was almost the same. These lesions were considered to be caused by secondary particles due to the passage of particles through the shielding materials.

Intra- and Interindividual Variability in Lymphocyte Chromosomal Aberrations: Implications for Cancer Risk Assessment

Chromosomal aberration frequency in peripheral lymphocytes of healthy individuals has been found to be predictive of future cancer risk. The variability of chromosomal aberrations over time, which is largely unknown, should be clarified to interpret the strength of this association and to determine its use in cancer prediction. Intra- and interindividual variability in chromosomal aberration frequency was therefore determined. From a pooled database comprising 11 national cohorts (1965-2002), the authors included 9,433 blood samples from 3,550 subjects with at least one repeated chromosomal aberration measurement. The generalized concordance correlation coefficient of 0.19 was low, indicating high intraindividual variability compared with interindividual variability, resulting in a high likelihood of misclassification. The relation between chromosomal aberration frequency and future cancer risk has probably been underestimated in previous studies. A single chromosomal aberration measurement seems not to be representative of the whole lifespan level of chromosome instability and greatly limits the use of chromosomal aberration frequency-as measured with Giemsa staining-for individual risk assessment.

Polymorphism of repair genes and cytogenetic radiation effects

Frequencies of spontaneous and γ-induced (1 Gy in vitro) chromosome aberrations in blood lymphocytes of 99 healthy volunteers were compared with the results of PCR genotyping for eight repair genes: XRCC1, XPD, ERCC1, APEX1, RAD23B, OGG1, ATM, and Tp53 (in all 11 polymorphic sites). The frequency of spontaneous aberrations of the chromosome type additively increased with the number of copies of minor allele variants 2251G and 862A of the nucleotide excision repair gene XPD (p = 0.025). The frequency of γ-induced chromosome aberrations proved to be elevated for the carriers of the minor allele OGG1 977G (p = 0.011). A significantly elevated level of γ-induced chromosome aberrations was also observed for the carriers of the major alleles XRCC1 G1996 and XRCC1 C580 (p = 0.002).

Estimation of relative biological effectiveness of tritium according to chromosome aberration frequency in human blood lymphocytes

The goal of this work was to determine the relative biological effectiveness (RBE) of tritium β-radiation according to the chromosome aberration frequency in the peripheral blood lymphocytes after in vitro and in vivo radiation exposures. The experimental RBE assessment of tritium β-radiation relative to 60Co γ-radiation according to unstable chromosome aberration frequency in the peripheral blood lymphocytes under particular conditions is described. It has been demonstrated that tritium β-radiation is, in general, more effective in the dose range of up to 1 Gy, which is most pronounced at low doses. The RBE value of tritium β-radiation at minimum doses reached 2.2 and decreased at higher doses (1 Gy) to 1.25. The data on comparative analysis of the frequency of stable chromosome aberrations in the blood lymphocytes of professional nuclear workers (Sarov, Russia) after long-term chronic exposure to tritium β-radiation, as compared with γ-irradiation, are reported for the first time. The higher biological effectiveness of tritium β-radiation was demonstrated and was estimated as 2.5.

A study protocol for the evaluation of occupational mutagenic/carcinogenic risks in subjects exposed to antineoplastic drugs: a multicentric project

BackgroundSome industrial hygiene studies have assessed occupational exposure to antineoplastic drugs; other epidemiological investigations have detected various toxicological effects in exposure groups labeled with the job title. In no research has the same population been studied both environmentally and epidemiologically. The protocol of the epidemiological study presented here uses an integrated environmental and biological monitoring approach. The aim is to assess in hospital nurses preparing and/or administering therapy to cancer patients the current level of occupational exposure to antineoplastic drugs, DNA and chromosome damage as cancer predictive effects, and the association between the two.Methods/DesignAbout 80 healthy non-smoking female nurses, who job it is to prepare or handle antineoplastic drugs, and a reference group of about 80 healthy non-smoking female nurses not occupationally exposed to chemicals will be examined simultaneously in a cross-sectional study. All the workers will be recruited from five hospitals in northern and central Italy after their informed consent has been obtained.Evaluation of surface contamination and dermal exposure to antineoplastic drugs will be assessed by determining cyclophosphamide on selected surfaces (wipes) and on the exposed nurses' clothes (pads). The concentration of unmetabolized cyclophosphamide as a biomarker of internal dose will be measured in end-shift urine samples from exposed nurses.Biomarkers of effect and susceptibility will be assessed in exposed and unexposed nurses: urinary concentration of 8-hydroxy-2-deoxyguanosine; DNA damage detected using the single-cell microgel electrophoresis (comet) assay in peripheral white blood cells; micronuclei and chromosome aberrations in peripheral blood lymphocytes. Genetic polymorphisms for enzymes involved in metabolic detoxification (i.e. glutathione S-transferases) will also be analysed.Using standardized questionnaires, occupational exposure will be determined in exposed nurses only, whereas potential confounders (medicine consumption, lifestyle habits, diet and other non-occupational exposures) will be assessed in both groups of hospital workers.Statistical analysis will be performed to ascertain the association between occupational exposure to antineoplastic drugs and biomarkers of DNA and chromosome damage, after taking into account the effects of individual genetic susceptibility, and the presence of confounding exposures.DiscussionThe findings of the study will be useful in updating prevention procedures for handling antineoplastic drugs.