Radiation signature on exposed cells: Relevance in dose estimation (original) (raw)
Related papers
Biological Dosimetry - Cytogenetics Findings At Persons Occupationally Exposed To Ionizing Radiation
Bosnian Journal of Basic Medical Sciences
A large number of physical and chemical agents are capable to course chromosomal aberrations. Ionizing radiation is frequent and well known course of chromosomal aberrations. If deoxyribonucleic acid (DNA) is irradiated before synthesis chromosomal-type aberrations are caused. Chromatid-type aberrations are results of DNA damages occurred during or after synthesis. Some of these changes could exist at patients several years after exposition. Biological dosimetry-cytogenetics analysis of persons occupational exposed to ionizing radiation in Federation of Bosnia and Herzegovina have been carried out in "Center for Human Genetics" of Medical Faculty in Sarajevo. In this study we have evaluated cytogenetics findings of persons employed in a zone of radiation. Cytogenetics findings have been demonstrated in allowed limit in 154 (81.1%) examinees, and cytogenetics findings were out of normal values in 36 (18.9%) examinees. The majorities who have been employed in a zone of ioniz...
International Journal of Modern Physics: Conference Series, 2016
In case of a radiation accident, it is well known that in the absence of physical dosimetry biological dosimetry based on cytogenetic methods is a unique tool to estimate individual absorbed dose. Moreover, even when physical dosimetry indicates an overexposure, scoring chromosome aberrations (dicentrics and rings) in human peripheral blood lymphocytes (PBLs) at metaphase is presently the most widely used method to confirm dose assessment. The analysis of dicentrics and rings in PBLs after Giemsa staining of metaphase cells is considered the most valid assay for radiation injury. This work shows that applying the fluorescence in situ hybridization (FISH) technique, using telomeric/centromeric peptide nucleic acid (PNA) probes in metaphase chromosomes for radiation dosimetry, could become a fast scoring, reliable and precise method for biological dosimetry after accidental radiation exposures. In both in vitro methods described above, lymphocyte stimulation is needed, and this limits...
European Journal of Radiology, 2010
The aim of the present study was to assess occupationally induced chromosomal damage in hospital workers exposed to low levels of ionizing radiation. Thirty-two interventional cardiologists, 36 nuclear medicine physicians and 33 conventional radiologists were included in this study, along with 35 healthy age-and sex-matched individuals as the control group. We used conventional metaphase chromosome aberration (CA) analysis, cytokinesis-block micronucleus (MN) assay as important biological indicators of ionizing radiation exposure. Occupational dosimetry records were collected over the last year (ranged from 0.25 to 48 mSv) and their whole life exposure (ranged from 1.5 to 147 mSv). The results showed significantly higher frequencies of dicentric and acentric CAs (p < 0.001) and MN (p < 0.01) in all exposed groups than in the controls. Taking all the confounding factors into account, no obvious trend of increased chromosomal damages as a function of either duration of employment, exposed dose, sex or age was observed. Interventional cardiologists had the highest rates of CA and MN frequencies between the worker groups, though the differences were not significant. These results indicate that long term exposure to low dose ionizing radiation could result in DNA damage. Hence, the personnel who work in the hospitals should carefully apply the radiation protection procedures.
Radiation Research, 2004
A multicolor banding (mBAND) fluorescence in situ hybridization technique was used to investigate the presence in human populations of a stable biomarker-intrachromosomal chromosome aberrations-of past exposure to high-LET radiation. Peripheral blood lymphocytes were taken from healthy Russian nuclear workers occupationally exposed from 1949 onward to either plutonium, y rays or both. Metaphase spreads were produced and chromosomes 1 and 2 were hybridized with mBAND FISH probes and scored for intrachromosomal aberrations. A large yield of intrachromosomal aberrations was observed in both chromosomes of the individuals exposed to high doses of plutonium, whereas there was no significant increase over the (low) background control rate in the population who were exposed to high doses of y rays. Interchromosome aberration yields were similar in both the high plutonium and the high y-ray groups. These results for chromosome 1 and 2 confirm and extend data published previously for chromosome 5. Intrachromosomal aberrations thus represent a potential biomarker for past exposure to high-LET radiations such as a particles and neutrons and could possibly be used as a biodosimeter to estimate both the dose and type of radiation exposure in previously exposed populations.
International Journal of Low Radiation, 2006
The quantification of unstable chromosomal aberrations and micronuclei in peripheral blood lymphocytes is a method commonly used in biodosimetry by cytogenetic analysis, especially when physical dosimetry cannot be performed. In this context, the aim of this research was to compare these methods in the biomonitoring of health professionals occupationally exposed to ionising radiation. In parallel, the C-banding technique was applied to confirm the presence of unstable chromosomal aberrations (dicentrics and rings). For this, samples of peripheral blood from health professionals of three hospitals (Recife -Brazil) were collected and lymphocyte cultures were carried out based on classical cytogenetic techniques. The number of cells scored per subject was the same (1000) for each assay. Among the individuals, those who do not usually wear a lead apron had higher frequencies of unstable chromosomal aberrations and micronuclei than the ones who carefully observe the radioprotection rules.
Evaluation of radiation risk: cytogenetic and molecular markers of low-dose radiation effects
For last 15 years, we have investigated low-dose radiation genetic effects on human populations affected by the Chernobyl accident. Cytogenetic longitudinal investigations showed that radiation markers for cleanup workers remained at an elevated level and had a trend to grow up with time. A dynamic profile of the amount of aberrations confirms that this group has symptoms of the genomic instability state formation. This situation correlated with the incidence of morbidity. The state of genomic instability correlates with accumulation in cleanup workers blood clastogenic factors, which are responsible for increased genomic instability. As a model, we used keratinocyte human line with blocked first check point of cell cycle. The same situation took place for gene mutations (investigated by T-cell receptor [TCR] test) and mitochondrial "common deletion" frequencies (in situ polymerase chain reaction [PCR]) in cleanup workers as for other groups in the affected population (for children, especially). The outcomes of biology dose reconstruction will be presented. Results of longitudinal investigations confirm that cytogenetic and molecular effects of irradiation can be fixed even 20 years after the Chernobyl accident.
Environmental …, 2007
The aim of the present study was to perform a cytogenetic analysis in peripheral lymphocytes of 36 individuals occupationally exposed to low levels of ionizing radiation, and compare the results with 36 controls, using the chromosomal aberrations test (CA), sensitivity to bleomycin and cytokinesis-blocked micronucleus assay (MN). The frequencies of CA/100 cells observed for the exposed workers were not significantly higher than in controls (P > 0.05). The mean break/cell (b/c) for the controls and exposed workers was 0.59 ± 0.39 and 0.57 ± 0.29, respectively (P > 0.01). The MN frequencies were significantly increased (P < 0.01) in exposed workers (6.13 ± 3.18) in comparison with controls (5.11 ± 3.85). The mean MN was also statistically higher in the non-smoker exposed when compared with non-smoker controls, 5.80 ± 3.09 and 5.15 ± 4.08, respectively (P < 0.01). The cytogenetic analysis of MN proved to be the most sensitive biological marker to assess the cellular response to low levels of irradiation.
Establishment and validation of a dose-effect curve for γ-rays by cytogenetic analysis
Mutation Research-fundamental and Molecular Mechanisms of Mutagenesis, 1995
A dose-effect curve obtained by analysis of dicentric chromosomes after irradiation of peripheral blood samples, from one donor, at 11 different doses of y-rays is presented. For the elaboration of this curve, more than 18000 first division metaphases have been analyzed. The results fit very well to the linear-quadratic model.
The micronucleus assay as a biological dosimeter of in vivo ionising radiation exposure
Mutagenesis, 2011
Biological dosimetry, based on the analysis of micronuclei (MN) in the cytokinesis-block micronucleus (CBMN) assay can be used as an alternative method for scoring dicentric chromosomes in the field of radiation protection. Biological dosimetry or Biodosimetry, is mainly performed, in addition to physical dosimetry, with the aim of individual dose assessment. Many studies have shown that the number of radiation-induced MN is strongly correlated with dose and quality of radiation. The CBMN assay has become, in the last years, a thoroughly validated and standardised technique to evaluate in vivo radiation exposure of occupational, medical and accidentally exposed individuals. Compared to the gold standard, the dicentric assay, the CBMN assay has the important advantage of allowing economical, easy and quick analysis. The main disadvantage of the CBMN assay is related to the variable micronucleus (MN) background frequency, by which only in vivo exposures in excess of 0.2-0.3 Gy X-rays can be detected.
Biosaintifika: Journal of Biology & Biology Education
Medical workers representing the group is the most consistently are exposed to low doses of ionizing radiation, prolonged low-level ionizing radiation can induce chromosomal aberrations (CAs). This study would evaluate the cytogenetic effect using the CAs based on dicentric, and cytokinesis-blocked micronucleus (CBMN) assay on hospital workers. The exposed group dividedto Interventional and Diagnostic groups then compared to non exposed group. The accumulated absorbed doses calculated for the radiation workers were below 5mSv. Blood samples were obtained from 29 samples of medical workers , and 15 samples of control. The Study showed that the frequency of dicentric chromosomes both in exposed and control were not found. In case of micronuclei, the mean frequencies were observed in exposed group that was (19 ±6.22) and (16.25 ± 6.04) respectively and the control group was (10.4±7.79). Frequency MN/1000 cell in the lymphocytes both in the two exposed group was relatively higher compared to control group. However the MN frequencies in all sample group was still in normal range. In this study chronic low radiation dose exposure in the hospital had no significant effect on chromosome aberration nor micronuclei. The benefit of the study is to enrich the potential usefulness of cytogenetic assay providing safety index in medical surveillance programs. The results suggest that education and retraining of staff concerning radiation safety guidelines need to be done to maintain the safety aspects of radiation.