Analysis of chromosome aberration and micronucleus frequencies in 102 patients with cancer before and after radiotherapy and chemotherapy / 中国辐射卫生

@#<b>Objective</b> To investigate the changes of chromosome aberration and micronucleus frequencies in the peripheral blood of patients with cancer before and after treatment, and to provide a basis for clinical prevention and treatment. <b>Methods</b> We collected the physical examination data of 102 patients with cancer before and after treatment from 2016 to 2021 to analyze the changes of chromosome aberration and micronucleus frequencies in peripheral blood. <b>Results</b> Before and after treatment, there were significant differences in chromosome aberration frequency and micronucleus frequency in peripheral blood lymphocytes in patients having radiotherapy or chemoradiotherapy (all <i>P</i> < 0.05), but no significant difference was observed in either index for patients having chemotherapy (both <i>P</i> > 0.05). Before and after radiotherapy, there were significant differences in the numbers of patients with abnormal chromosome aberration frequency and those with abnormal micronucleus frequency in lymphocytes (both <i>P</i> < 0.001). Before and after chemotherapy, there was no significant difference in the number of patients with abnormal chromosome aberration frequency (<i>P</i> = 0.100) or those with abnormal micronucleus frequency (<i>P</i> = 0.110). <b>Conclusion</b> Radiotherapy can cause abnormalities in chromosome aberration and micronucleus frequencies in peripheral blood lymphocytes, which can be useful for monitoring radiotherapy injury to formulate effective emergency plans and evaluate radiation dose in each course of treatment.

An analysis of occupational health examination results of 450 radiation workers in a steel mill / 中国辐射卫生

@#<b>Objective</b> To investigate the occupational health status of 450 radiation workers in a steel mill when they resigned, and to provide references and suggestions for the occupational health monitoring of the enterprise employees and for the workers’ proper arrangement after their resignations. <b>Methods</b> Occupational health examinations were performedon 450 steel workers who were about to resign in accordance with the applicable laws and regulations. And the examination results were statistically analyzed. <b>Results</b> Among the 450 radiation workers, 82% had abnormal examination results which included chromosome aberration in peripheral blood lymphocytes (4.89%), lens opacity (44.44%), pinguecula (25.33%), hypertension (28.22%), thyroid dysfunction (9.59%), and abnormal liver ultrasound findings (30.89%). Compared with the normal population, these steel workers had a significantly higher chromosome aberration rate in peripheral blood lymphocytes and a significantly higher incidence rate of ocular disorders. <b>Conclusion</b> It is important to effectively manage the occupational health of radiation employees in steel mills, and to regularly provide training on occupational health protection. To avoid radiation damage, workers should pay close attention to radiation protection at work, especially eye protection, to avoid eye disorders.

Analysis of cytogenetic indexes in interventional radiology workers exposed to low dose long-term chronic irradiation / 中国职业医学

OBJECTIVE: To observe the effect of low dose long-term chronic irradiation on chromosome aberration and micronucleus in peripheral blood lymphocytes of interventional radiology workers.METHODS: A total of 100 interventional radiology workers in a grade A tertiary hospital of Henan Province were selected as the interventional group using a convenient sampling method, and 78 healthy individuals without radiation exposure were selected as the control group. The incidence of chromosomal aberration and micronucleus of peripheral blood lymphocytes in individuals of these two groups were investigated. RESULTS: The frequencies of cells with acentric fragment(ace), dicentric chromosome(dic), reciprocal translocation(t), chromosome type aberration and total aberration in the interventional group were higher than those in the control group, and the differences were statistically significant(0.55% vs 0.30%, 0.25% vs 0.03%, 0.38% vs 0.01%, 1.21% vs 0.34%, 1.37% vs 0.54%, all P<0.01). In the interventional group, the frequency of cell with chromosome type aberration was higher than that of chromatid type aberration(1.21% vs 0.16%, P<0.01).The frequency of cell with unstable chromosome aberration was higher than that of stable chromosome aberration(0.80% vs 0.41%, P<0.01), and the frequency of cell with chromosomal type aberrant in the interventional group ranked from high to low in order of ace, t, dic and deletion(P<0.01). The incidence of micronuclear cells and micronucleus in the interventional group were higher than those in the control group(0.86‰ vs 0.40‰, 0.89‰ vs 0.41‰, all P<0.01). The incidence of micronuclear cells and micronucleus of female interventional radiology workers were higher than those of male workers(1.12‰ vs 0.62‰, 1.19‰ vs 0.62‰, all P<0.01).CONCLUSION: Low dose and long-term chronic irradiation exposure can affect both chromosome aberration and micronucleus of interventional radiology workers. The main chromosomal aberrations were non-stable chromosomal aberrations ace, dic and stable chromosomal aberrations t.

Genotoxicity and Embryotoxicity Study of Bicyclol Methyl Ether, Main Impurity in Bicyclol / 中国结合医学杂志

OBJECTIVE@#To assess the genotoxicity and embryotoxicity of bicyclol methyl ether (BME), the main impurity in bicyclol.@*METHODS@#Five concentrations of BME (0.5, 5, 50, 500 and 5000 μg/plate) were used in the Ames test to detect gene mutation. In the chromosome aberration test, Chinese hamster lung cells were used to detect chromosomal aberration of BME (15, 30, 60, 120 μg/mL) with or without S9 mixture. Embryotoxicity test was also conducted to determine any embryotoxicity of BME (7.5, 22.5, 67.5 μg/L) using zebrafish embryos.@*RESULTS@#No significant differences were observed in the Ames test and the chromosome aberration test in the BME groups compared with the vehicle control group. The zebrafish embryos toxicity test also showed no embryo development toxicity of BME, including hatching rate, body length, pericardial area and yolk sac area.@*CONCLUSIONS@#Bicyclol methyl ether has no genotoxicity in vitro and embryotoxicity in zebrafish embryos, and the impurity in bicyclol is qualified.

Dose Estimation Curves Following In Vitro X-ray Irradiation Using Blood From Four Healthy Korean Individuals

Cytogenetic dosimetry is useful for evaluating the absorbed dose of ionizing radiation based on analysis of radiation-induced chromosomal aberrations. We created two types of in vitro dose-response calibration curves for dicentric chromosomes (DC) and translocations (TR) induced by X-ray irradiation, using an electron linear accelerator, which is the most frequently used medical device in radiotherapy. We irradiated samples from four healthy Korean individuals and compared the resultant curves between individuals. Aberration yields were studied in a total of 31,800 and 31,725 metaphases for DC and TR, respectively, obtained from 11 X-ray irradiation dose-points (0, 0.05, 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 5 Gy). The dose-response relationship followed a linear-quadratic equation, Y=C+αD+βD², with the coefficients C=0.0011 for DC and 0.0015 for TR, α=0.0119 for DC and 0.0048 for TR, and β=0.0617 for DC and 0.0237 for TR. Correlation coefficients between irradiation doses and chromosomal aberrations were 0.971 for DC and 0.6 for TR, indicating a very strong and a moderate correlation, respectively. This is the first study implementing cytogenetic dosimetry following exposure to ionizing X-radiation.

Establishment and validation of the dose-response curve of X-rays irradiation and chromosome aberrations in human peripheral blood cells / 中国职业医学

OBJECTIVE: To explore the dose-effect of X-ray irradiation and chromosome aberrations in human peripheral blood cells,and establish a dose-response curve of dicentric and ring(dic+r)aberration induced by X-ray irradiation.METHODS: Human peripheral blood samples were collected from three healthy individuals and were exposed to X-ray at the doses of 0.00,0.25,0.50,0.75,1.00,2.00,3.00,4.00 and 5.00 Gy in vitro.The dose rate was 1.158 Gy/min.The blood cells were harvested after routine culture,and the chromosome preparation was carried out.The dicentrics and rings in metaphase cells were counted under microscope,and a dose-response curve was fitted by using the software of CABAS.Dose estimation was performed according to the curve from two blind samples.RESULTS: Aberration of dic+r increased with irradiation doses in the range of 0.00-5.00 Gy(P<0.01).The dose-response relationship followed a linear-quadratic equation:■,where■ is the yield of dic+r,and D is the irradiated dose.The estimated doses of the two blind samples were in accordance with the actual doses.CONCLUSION: The dose-response curve and mathematical model of chromosome aberration following exposure to 0.00-5.00 Gy X-ray irradiation is established in this study provide a reliable method for the accurate dose estimation.

A 3-year follow-up cytogenetic observation on victims exposed to iridium-192 in a radioactive sourcer-loss accident in Nanjing City / 中国职业医学

OBJECTIVE: To observe the decay law of chromosome aberrations after 3 years iridium-192 radiation exposure in victims of Nanjing “5.7” radiation accident. METHODS: The peripheral blood of victims was collected 3 years after iridium-192 radiation exposure. The routine chromosome aberration analysis, micronucleus analysis and G-banding karyotype analysis were used to detect the chromosomal instability rate, the binuclear micronucleus rate and the stability distortion rate. A dose reconstruction was carried out based on the distortion results. RESULTS: The aberration frequency of dicentric(dic) and centric rings(r) was 6.5% after 3 years iridium-192 radiation exposure, which decreased to 31.0% at 6 days after exposure(the aberration frequency of dic and r was 21.0%). The estimated biological dose based on the aberration frequency of dic and r was 0.75 Gy, which is about 50.0% of the initial estimated dose(1.52 Gy) at 6 days after exposure. The micronucleus rate of the binuclear lymphocytes was 63.0‰, and the estimated biological dose based on the micronucleus rate was 0.71 Gy, which was similar to the estimated dose of aberration frequency of dic and r. The total frequency of chromosome aberration observed by karyotype analysis of G-bands by trypsin using Giemsa was 41.0%, the stability aberration frequency was 30.0%, and the translocation frequency was 15.0%. The result of dose reconstruction based on the translocation frequency was 1.50-1.89 Gy, which was very close to the initial estimated dose(1.52 Gy). CONCLUSION: The decay of unstable chromosome aberration may be influenced by many factors, more detailed data need to be accumulated to study the decay law. The use of stable chromosomal aberrations, especially translocation frequencies used in dose reconstruction in earlier exposures, is an ideal method.

Analysis of results of national biological dose estimation / 中华放射医学与防护杂志

Objective To analyze the biological dose estimation ability of the radiation health technology institutions nationwide from 2015 to 2017,and their development in recent years.Methods SPSS 19.0 software was used to analyze and pack the data involved in the 2015-2017 year assessments by using x2 test.Statistical analysis was conducted of qualification rate,excellent rate,participating units and dose estimation deviation distribution.Results The qualification rate gradually increased from 2015 to 2017.Compared with 2015,the passing rate significantly increased in 2017 with statistically significant difference(x2 =3.978,P ＜0.05).A total of 53 units participated in the biological dose assessment,of which 30 units were involved over the three consecutive years,accounting for 57％.In the distribution of the relative deviation of dose estimates made by the units participating in the three-year assessment,the proportion of estimated deviations in the range of 5％-10％ increased whereas those in the range of 15％-20％ and ＞ 20％ decreased.Conclusions During 2015-2017 year period the biological dose estimation ability of all units involved in the assessment nationwide was basically stable,with gradually improved test level,qualification rate and steady excellence rate.

Analysis on chromosome aberration rate, micronucleus cell rate and related factors of 3021 radiation workers in Changzhou / 中华劳动卫生职业病杂志

Objective@#To investigate the chromosomal aberration rate, micronucleus cell rate and the related factors of radiation workers in Changzhou, provide evidence for the occupational health and safety of radiation workers.@*Methods@#Descriptive analysis of the chromosomal aberration rate, micronucleus cell rate and the related factors of 3021 radiation workers who conducted occupational health examination in the Changzhou Center for Disease Control and prevention in 2017, multivariate logistic regression was used to analyze the data.@*Results@#The abnormal rate of chromosome aberration and micronucleus cells of 3021radiation workers in Changzhou were 1.32% and 3.34% respectively. The results of multivariate logistic regression showed that the exposure year (OR=1.501, 95%CI:1.078~2.089, P=0.016) was a risk factor for chromosome aberration. The risk of chromosome aberration in radiation therapy (OR=6.417, 95%CI:1.360~30.280, P=0.019) and interventional radiology (OR=4.598, 95%CI:1.688~12.524, P=0.003) was higher than that of industrial application. the exposure year (OR=1.245, 95%CI:1.007~1.539, P=0.043) is also a risk factor for micronucleus cell rate. The micronucleus cell rate abnormality Risk of nuclear medicine (OR=3.934, 95%CI:1.305~11.858, P=0.015) , radiation therapy (OR=3.802, 95%CI:1.101~13.128, P=0.035) , and interventional radiology (OR=2.953, 95%CI:1.324~6.584, P=0.008) is higher than industrial application.@*Conclusion@#The chromosome aberration rate and micronucleus rate of workers who are exposed to low dose ionizing radiation for long time are related to the exposure year of radiation workers and the occupational categories involved.

Quality control of chromosome preparation in the chromosome aberration test in vitro / 中国比较医学杂志

Objective To study the influencing factors and quality control of chromosome preparation during chromosome aberration test in vitro,and to summarize and analyze the method and key points of successful preparation of chromosome specimens in vitro. Methods Chinese hamster lung cells(CHL)were used for cell culture and chromosome preparation. Mitomycin and cyclophosphamide were used as positive mutagens. After routine hypotonic treatment,fixation, and squash preparation, finally, to read the film under the microscope. Results The CHL chromosome aberration test showed that both the chromosome aberration rates of mitomycin- and cyclophosphamide-treated cells were significantly increased(>20%),while the aberration rates in the negative control group were less than 5%, either with and without metabolic activation. The success rate was high and the prepared chromosomes were well dispersed with a moderate length. Conclusions Many factors can affect the specimen preparation in chromosome aberration test. Every step is very important,and it should be strictly following the operating procedures. It is of importance to grasp the principle of each step and to operate carefully,patiently and scientifically in order to prepare good specimens.

Effect of delayed pre-job occupational health examination on results of radiation exposed workers / 中国职业医学

OBJECTIVE: To explore the effect of delayed pre-job occupational health examination on occupational health surveillance by analyzing the results of pre-job occupational health examinations in radiation exposed workers. METHODS: A convenience sampling method was used to select 1 385 radiation workers as the research subjects in Guangdong Province in 2016 at a pre-job occupational health examination. Workers who did not engage in radiation work were selected as control group. Workers who engaged in radiation work but did not take pre-job occupational health examinations were selected as observation group. The difference of the results of occupational health examination between the two groups was analyzed. RESULTS: The proportion of the observation group was 55. 8%(773/1 385). The abnormal rates of the white blood cell( WBC) count,“double + ring”rate and lens in the observation group were higher than those in the control group(9. 3% vs 5. 7%,6. 0% vs 3. 6%,6. 2% vs 3. 6%,P < 0. 05),respectively. The WBC count in the observation group was lower than that in the control group [(6. 1 ± 1. 5) × 10~9/L vs(6. 7 ± 1. 5) × 10~9/L,P < 0. 01]. The contents of the thyroid stimulating hormone and triiodothyronine in the observation group were higher than those in the control group[(1. 3 ± 0. 4) m U/L vs(1. 2 ± 0. 3) m U/L,(1. 8 ± 0. 4) nmol/L vs(1. 7 ± 0. 5) nmol/L,P < 0. 01]. The tetraiodothyronine level in the observation group was lower than that in the control group [( 110. 8 ± 22. 4) nmol/L vs(113. 8 ± 23. 2) nmol/L,P < 0. 05]. CONCLUSION: The delay of pre-job occupational health examination of radiation exposed workers affects the examination results and the accuracy of basic health records.

Overview of current situation and future development of radiation biodosimetry study / 中华放射医学与防护杂志

Radiation biodosimetry is an important part of radiation medicine. Some new discoveries and progresses have been made in radiation biodosimetry studies in recent years. Cytogenetic method represented by chromosome aberration analysis as the golden standard of radiation biodosimeter is being transformed to automate analysis, and a number of international, regional and national laboratory networks of radiation biodosimetry are being established. As a widely acceptable molecular marker of DNA damage,γ-H2AX has made rapid progress in radiation dose estimation. Based on the expressions of protein and genes, further advancements have been made in the studies of metabolites and miRNAs. At the same time, with the development of proteomics technology, there are some breakthroughs in the study of using molecular expression profiling to evaluate radiation dose. The research progresses of radiation biodosimetry is reviewed in this paper.

Overview of current situation and future development of radiation biodosimetry study / 中华放射医学与防护杂志

Radiation biodosimetry is an important part of radiation medicine. Some new discoveries and progresses have been made in radiation biodosimetry studies in recent years. Cytogenetic method represented by chromosome aberration analysis as the golden standard of radiation biodosimeter is being transformed to automate analysis, and a number of international, regional and national laboratory networks of radiation biodosimetry are being established. As a widely acceptable molecular marker of DNA damage,γ-H2AX has made rapid progress in radiation dose estimation. Based on the expressions of protein and genes, further advancements have been made in the studies of metabolites and miRNAs. At the same time, with the development of proteomics technology, there are some breakthroughs in the study of using molecular expression profiling to evaluate radiation dose. The research progresses of radiation biodosimetry is reviewed in this paper.

Establishing dose-response curve of chromosome aberration induced by in vitro X-ray irradiation in human peripheral blood / 中国职业医学

OBJECTIVE: To establish the dose-response curve of chromosome aberration induced by X-ray irradiation in human peripheral blood in vitro. METHODS: The median cubital vein blood of healthy male donors were collected and irradiated with X-ray at the dose of 0. 00-5. 00 Gy in vitro. The dose rate was 0. 8 mGy/s. The cells were cultured with colchicine and stained with routine Giemsa staining. The slices were blindly examined. The morphology of chromosomes were recorded as dicentric,multi-centric,dicentric plus rings or fragments( hereinafter referred to as dicentric + ring) in metaphase cells. The occurrence of dicentric + ring and the irradiation dose was used to create the dose-response curve.RESULTS: The results showed that the occurrence of dicentric + ring in abnormal cells increased with the increasing irradiation dose in the range of 0. 00-5. 00 Gy( P < 0. 01). The best fitting equation of 0. 00-1. 00 Gy is y = 23. 22 D2+4. 768 D-0. 018( P < 0. 01). The best fitting equation of 0. 50-5. 00 Gy is y = 34. 23 D-3. 072( P < 0. 01).CONCLUSION: The fitting degree of dose-response curve is good,which can be used as reference in laboratory to assess irradiation exposure dose.

Effects of different radiation on chromosome aberration in human lymphoblastoid cells / 中国职业医学

OBJECTIVE: To compare the effects of ~(56)Fe~(17+),~(12)C~(6+)ion beams and~(60)Co γ rays on chromosome aberration in human lymphoblastoid cells. METHODS: The human lymphoblastoid cells were divided into 0. 1,0. 3,0. 5,0. 7,1. 0,2. 0 Gy irradiated groups and 0. 0 Gy control group. They were separately exposed to ~(56)Fe~(17+)ion beams( linear energy transfer was 400. 0 ke V/μm),~(12)C~(6+)ion beams( linear energy transfer was 26. 0 ke V/μm) and~(60)C γ rays. Chromosome specimens were harvested 48 hours after irradiation. The effects of different radiation on dicentric plus centric ring( “d + r”) aberration rate and chromosome aberration in human lymphoblastoid cells were detected by light microscope with artificial counting. RESULTS: The “d + r”aberration rates induced by 0. 3-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)Co γ rays at the same dose( P < 0. 017). Chromosome aberration cell rates of 0. 1-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)C γ rays at the same dose( P < 0. 017). At the dose range of 0. 0-2. 0 Gy,chromosome aberration effects of three kinds of radiations were gradually increased( P < 0. 01). The relative biological effectiveness of ~(56)Fe~(17+)ion beams was lower than that of ~(12)C~(6+)ion beams.CONCLUSION: The chromosome aberration induced by ~(12)C~(6+)ion beams was more serious than that of~(60)Co γ rays and ~(56)Fe~(17+)ion beams.

Mutagenicity evaluation of the hydrolysate of Meretrix meretrix Linnaeus soft tissue / 中国实验动物学报

Objective To evaluate the mutagenicity of hydrolysate of Meretrix meretrix Linnaeus soft tissue, so as to provide experimental basis for its exploitation.Methods Three mutagenicity tests were used to evaluate the mutagenic effects, including Ames test, CHL chromosome aberration assay and bone marrow micronucleus assay in mice.Results In Ames test, the revertant colonies numbers in each group were twice less than the numbers of spontaneous revertant colo-nies, five bacterial strains showed negative results with or without S9 activation, and the result of Ames test was negative. The CHL chromosome aberration assay and bone marrow micronucleus assay showed that the chromosome aberration rate and micronucleus rate of each dose group showed no significant difference compared with the negative control group, respec-tively ( P>0.05) .Conclusions Under this condition, the results show that all of the Ames test, chromosome aberration assay and bone marrow micronucleus assay are negative, and no mutagenicity is observed in the hydrolysate of Meretrix mer-etrix Linnaeus soft tissue.

Biological dose estimation in the victim exposed to the iridium-192 in a radioactive source-loss accident in Nanjing City / 中国职业医学

OBJECTIVE: To estimate the biological dose by the chromosome aberration analysis in a victim suffered in the radioactive source-loss accident in Nanjing City. METHODS: Peripheral blood sample of the victim was collected 6 days after radioactive exposure. Individual radioactive biological dose was estimated by identifying the aberration of the dicentrics plus centric rings in the metaphase chromosome of cells. The distribution of chromosome aberration was tested by the Poisson distribution. Impure Poisson distribution was used to estimate the radiation dose. RESULTS: Among the 353 cells observed at metaphase,75 aberration of dicentrics plus centric rings were found,43 cells had 1 aberration and 7 cells had 2 aberrations. Moreover,there were 3 multi-aberration cells with 3,4 and 11 aberrations respectively. The average individual radiation dose was estimated to be 1. 52 Gy,which was consistent with the clinical diagnosis as mild acute bone marrow radiation disease. The Poisson distribution u test revealed that the patient suffered from nonhomogeneous radiation.By the impure Poisson distribution test,the radiation exposure proportion of the whole body was estimated to be 55% and the average dose was 3. 02 Gy. CONCLUSION: The biological dose estimation was successfully performed,the results showed that this was a case of nonhomogeneous irradiation.

Donación de ovocitos vitrificados en paciente con síndrome de Turner

El síndrome del Turner es una aberración cromosómica con pérdida total o parcial de uno de los dos cromosomas sexuales. La característica clásica es la baja estatura y la insuficiencia ovárica debido a la disgenesia ovárica. La donación de ovocitos ha hecho posible que pacientes con ST puedan gestar, pero con alta mortalidad materna por rotura de la arteria aorta o por desórdenes hipertensivos. Se da a conocer el embarazo múltiple de un paciente con ST en un programa de donación de ovocitos vitrificados.

Turner syndrome is a chromosome aberration with complete or partial loss of one of the sexual chromosomes. Classical characteristics are short stature and ovarian failure due to dysgenesia. Oocyte donation has made possible gestation in Turner's patients but resulting in high maternal mortality due to rupture of the aorta or hypertensive disorders. The case of a Turner syndrome patient resulting in multiple pregnancy in a vitrified oocyte donor program is presented.

Application of digital polymerase chain reaction technology for noninvasive prenatal test

Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.

Effects of high natural background radiation on chromosome aberration frequency of peripheral blood lymphocytes of long-term exposed inhabitants: a Meta analysis / 中华放射医学与防护杂志

Objective To quantitatively analyze the effects of high background radiation area (HBRA) on the frequencies of translocation and unstable chromosome aberrations in human peripheral blood lymphocytes.Methods Based on the data from 9 published articles retrieved from 7 electronic databases,the Meta-analysis was performed to evaluate the effects of high natural background radiation (HNBR) on the frequencies of chromosome aberrations in the peripheral blood lymphocytes in 17 777 persons from HBRA and 10 386 from the control area (CA).Cochrane's Q and I2 statistics were used to evaluate heterogeneity among studies and pooling odds ratio (OR) with 95％ confidence intervals (95％ CI) were calculated using random-effect models.Publication bias was also calculated by funnel plot,Egger linear regression test and Begg rank correlation test.Results The pooling OR of translocation [OR(95％ CI) =1.57(1.10-2.24)] and unstable chromosome aberration [OR(95％ CI) =2.04(1.32-3.14)] of long-term exposed inhabitants living in HBRA were higher than control.The subgroup analysis showed that,fortranslocation,the OR (95％ CI) were 1.24 (1.09-1.42,I2 =0.00) for male,1.37 (1.17-1.60,I2 =0.00) for female,1.17 (1.05-1.30,I2 =69.50％) for adults,and 1.38 (1.25-1.51,I2 =0.00) for Chinese.For unstable chromosome aberration,the OR (95％ CI) were 3.78 (2.40-5.97,I2 =0.00) for female,2.60 (2.25-3.00,I2 =69.60％) for adults,1.03(0.85-1.24,I2 =0.00) for children,3.19 (2.46-4.13,I2 =21.60％) for Iranian,and 1.64 (1.33-2.02,I2 =0.00) for Chinese.HBRA,age and sex differences were the reasons of above heterogeneity.Conclusions To the inhabitants living in HBRA,the frequencies of translocation and unstable chromosome aberration of peripheral blood lymphocytes are higher than those in control area.More comprehensive analysis should be performed to assess the health risk in HBRA inhabitants,which may arise new stragety in radiation protection.