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@#<b>Objective</b> To investigate the effects of lowdose ionizing radiation (LDIR) on oxidative stress and damage repair in human bronchial epithelial (HBE) cells. <b>Methods</b> HBE cells were divided into 0, 50, 100, and 200 mGy groups, and cultured for 24 and 48 h after X-ray irradiation, respectively. The cell viability, levels of glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy-2’-deoxyguanosine (8-OHdG), and transcriptional levels of DNA damage repair genes <i>PPP2R2D</i> and <i>TP53</i> were measured. <b>Results</b> At 24 h after irradiation, there was no significant difference in the cell viability between the dose groups and the control group (<i>P</i> > 0.05); all dose groups had significantly increased MDA level, dose-dependently decreased GSH level, dose-dependently increased 8-OHdG level, and significantly increased mRNA level of <i>PPP2R2D</i> gene (all <i>P</i> < 0.05); the mRNA expression level of <i>TP53</i> gene was significantly increased in the 50 mGy group (<i>P</i> < 0.05). At 48 h after irradiation, there were the highest cell viability, significantly decreased MDA and 8-OHdG levels, and significantly increased mRNA expression levels of <i>PPP2R2D</i> and <i>TP53</i> genes in the 50 mGy group compared with the control group (all <i>P</i> < 0.05); the GSH level in the 100 mGy group was significantly increased (<i>P</i> < 0.05). <b>Conclusion</b> LDIR, especially radiation at 50 mGy, can affect the oxidative-antioxidant level in HBE cells and the transcript-level differential expression of DNA damage repair genes.
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Background The thyroid gland is one of the organs sensitive to ionizing radiation, and there are few studies on the effects of long-term exposure to low doses of ionizing radiation on the thyroid gland of radiation workers. Objective To investigate thyroid abnormalities in workers in medical radiology departments in Guangdong Province and to identify potential influencing factors of thyroid abnormalities. Methods A total of 1657 radiation workers from 48 hospitals in Guangdong Province were selected as survey subjects using convenience sampling, and their personal dose monitoring results and health examination information were retrospectively analyzed to determine the factors affecting thyroid abnormalities. Results The M (P25, P75) of thyroid absorbed dose (DT) was 1.55 (0.65, 3.96) mGy in the 1657 investigated workers. The attribute-specific medians of DT were 1.29, 1.38, 1.99, and 3.51 mGy for departments of diagnostic radiology, interventional radiology, radiotherapy, and nuclear medicine, respectively; and 1.10, 1.55, and 1.80 mGy for job titles of nurse, technician, and physician, respectively. Differences in DT by gender, age, years of radiological work, age of radiation exposure onset, occupational category, and job title were statistically significant (Z=−6.35, H=708.52, 918.20, 31.19, 95.64, 39.28, P<0.05). The positive rate of thyroid abnormalities in investigated workers was 46.53% (771/1657). Among them, the positive rate of abnormal thyroid function was 22.87% (379/1657), that of abnormal thyroid morphology was 33.98% (563/1657), and that of thyroid nodule was 26.55% (440/1657). The differences in thyroid abnormality rates by gender, age, years of radiation work, age of radiation exposure onset, DT, and job title of radiation workers were statistically significant (χ2=51.89, 49.64, 20.54, 18.29, 12.07, 16.16, P<0.05). The differences in abnormal thyroid function positive rate by gender, age of radiation exposure onset, and job title were statistically significant (χ2=26.21, 6.21, 8.32, P<0.05). The differences in the positive rates of abnormal thyroid morphology and nodules were statistically significant by gender, age, years of radiological work, age of radiation exposure onset, DT, and job title (abnormal thyroid morphology, χ2=40.24, 64.17, 37.63, 15.17, 19.28, 15.05; nodules, χ2=31.41, 77.98, 42.11, 19.16, 21.70, 13.52, P<0.05). The positive rates of thyroid abnormality, thyroid morphology abnormality, and nodules all showed a linear increasing trend with increasing age, years of radiation work, and age of radiation exposure onset (P<0.05). The results of logistic regression analysis indicated that the factors influencing thyroid abnormalities were female (OR=2.17, 95%CI: 1.72-2.74), increased years of radiological work (OR=1.04, 95%CI: 1.03-1.06), onset of radiation exposure in age groups of 30-34 and ≥35 years (OR=1.63, 95%CI: 1.12-2.37; OR=2.58, 95%CI: 1.74-3.29), and working in department of diagnostic radiology (OR=1.40, 95%CI: 1.07-1.84). Conclusion Long-term exposure to low doses of ionizing radiation has an effect on thyroid abnormalities in medical radiation workers. Among them, being female, physicians, and working in department of diagnostic radiology are at a higher risk of abnormal thyroid function; being female, increased years of radiation work, and radiation exposure onset at age ≥30 years are associated with a higher risk of reporting abnormal thyroid morphology.
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Background Radiation-induced liver damage is a major complication for primary liver cancer and other upper abdominal tumors during radiation therapy. The early biological effects of radiation-induced liver damage at different doses of radiation and its mechanisms of action have not yet been elucidated. Objective To establish X-ray-induced radioactive mouse liver damage model and explore the level of oxidative stress and its correlation with nuclear factor-κB (NF-κB) and transforming growth factor-β1 (TGF-β1). Methods A total of 24 male C57BL/6J mice aged 6 weeks were randomly divided into 4 groups (control, 0.8 Gy, 1.6 Gy, and 4 Gy), with 6 mice in each group. X-rays irradiated the whole body of mice singly in each dose group. At 24 h after radiation, histopathological changes in mouse liver were evaluated; peripheral blood cell count, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, as well as liver tissue superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, reduced glutathione (GSH) level, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) level were measured; real-time fluorescence quantitative PCR was used to detect liver tissue NF-κB p65 and TGF-β1 mRNA expression levels; the correlations of oxidative stress indicators with NF-κB p65 and TGF-β1 mRNA expression levels were analyzed by Pearson correlation. Results Compared with the control group, at 24 h after different doses of X-ray radiation, early injury-related histopathological changes were observed in liver, and the serum levels of AST and ALT were significantly increased in the 4 Gy group (P<0.05); the numbers of peripheral blood leukocytes and lymphocytes were decreased in the radiation exposure groups (P<0.05), showing a decreasing trend with increasing radiation doses; the levels of liver oxidative stress indicators (MDA, SOD, and GSH) in exposed mice were significantly increased (P<0.05), showing an increasing trend with increasing radiation doses. The liver 8-OHdG were significantly increased in the 1.6 Gy and 4 Gy groups compared with the control and the 0.8 Gy groups, respectively (P<0.05). The NF-κB p65 and TGF-β1 mRNA expression levels in the liver of mice were significantly increased in the 1.6 Gy and 4 Gy groups compared with the control group (P<0.05). The TGF-β1 mRNA expression level also exhibited an increasing trend with increasing radiation doses. The results of correlation analysis showed that the levels of MDA, SOD, GSH, and 8-OHdG in liver tissues were significantly and positively correlated with the expression levels of NF-κB p65 and TGF-β1 mRNA (P<0.05). Conclusion X-rays of various doses can affect the degree of liver injury, peripheral blood cell count, serum levels of AST and ALT, and liver oxidative stress levels in mice. The level of oxidative stress induced by X-ray is positively correlated with NF-κB and TGF-β1 in liver tissues, and it may participate in the process of radiation-induced liver injury.
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Objective:To analyze the serum lipid levels, and its influencing factors, of male residents around an uranium mine in order to provide a scientific basis for health risk assessment for such residents.Methods:With such a mine as the center, the surveyed subjects were divided into four groups as within 5, 10, 15 and 20 km of this mine, respectively. These male residents living around the mine were randomly selected as subjects. A health questionnaire survey was conducted among the subjects. The indicator such as height, weight and blood pressure were measured by means of the standard method. Peripheral venous blood was extracted from the subjects, and their venous blood glucose and serum lipid were detected. The levels of serum lipid and detectable rates of abnormal serum lipid were analyzed by using univariate analysis, and multivariate logistic regression analysis was used to analyze the influencing factors of dyslipidemia.Results:A total of 867 males at age 40 to 69 was included in the vicinity of the mine. The mean levels ( ± s) of TC, TG, LDL-C, and HDL-C were (5.46±1.11), (1.92±1.64), (3.19±1.02), and (1.39±0.43) mmol/L, respectively. 384 subjects with dyslipidemia were totally detected in the residents, and the detection rate was 44.29% (384/867). Of the residents with dyslipidemia, the majority was abnormal in two lipid related indexes (45.57%, 175/384). Univariate analysis result showed that there was statistically significant difference in TG level in different distance groups ( F=3.34, P<0.05). There were statistically significant differences in the abnormal detection rates of TG and HDL-C in subjects in different distance groups ( χ2=9.52, 10.18, P<0.05). The detection rates of dyslipidemia were significantly different in the groups of BMI, blood pressure and blood glucose ( χ2=45.91, 32.31, 11.42, P<0.05). Multivariate logistic regression analysis showed that excluding marital status and degree of education, the BMI, blood pressure and blood glucose all had an impact on dyslipidemia. The residents with overweight ( OR=2.08, 95% CI: 1.52-2.86) and obeseness ( OR=2.88, 95% CI: 1.58-5.24) had a higher risk for dyslipidemia than those with normal weight. The risks for dyslipidemia in the residents with hypertension ( OR=1.94, 95% CI: 1.45-2.60) and hyperglycemia ( OR= 2.17, 95% CI: 1.27-3.69) were higher than those with normal blood pressure and blood glucose, respectively. Conclusions:The detection rate of dyslipidemia is higher in male residents around the mine. The BMI, alcohol consumption, blood pressure, blood glucose and distance from the mine are influencing dyslipidemia and other relevant indexes. Overweight is an independent risk factor for dyslipidemia and its components. The distances from uranium mine has no significant effect on the dyslipidemia of male residents.
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@#<b>Objective</b> To investigate the differences in output results between difference analysis software, and to provide a reference for the improvement of quality control and the standard revision of SPECT equipment. <b>Methods</b> The image analysis software for quality control held by 14 radiological health technical service institutions was selected as the research subjects using the cluster sampling method. The results of the comparison were analyzed and evaluated according to the Z-score method with certified reference values. <b>Results</b> In the comparison items of “intrinsic uniformity” and “intrinsic spatial linearity”, the number of software with suspicious, deviated and incorrect results accounted for a relatively high proportion, while the results of other comparison items were satisfactory. <b>Conclusion</b> The applicability of SPECT image analysis software lacks effective supervision measures. Relevant departments should introduce feasible measures to standardize the software production and update process, accelerate the construction of radiological health information reporting platform, and promote the healthy development of the radiation health testing industry.
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Objective To obtain the information on the frequency of diagnostic X-ray examinations in Guangdong province in order to provide reference data for the rational application of diagnostic radiology.Methods A typical stratified sampling method was used to select 56 medical institutions in 7 districts in Guangdong province for the survey of the frequencies of diagnostic X-ray examinations.Multiple linear regression analysis was performed using the relevant variables of the surveyed sample (total number of hospitals,number of outpatients,number of inpatients,number of radiation workers,and number of diagnostic equipment).The dependent independent variables were fitted to the linear regression equation to estimate the frequency of routine diagnostic X-ray examinations and diagnostic CT examinations and the total frequency of diagnostic medical X-ray examinations in Guangdong province in 2016.Results By the largest percentage contribution,chest radiography accounted for 60.84％ of the routine diagnostic X-ray examinations,brain scans 28.03％ of diagnostic CT examinations,and cardiovascular interventions 48.83％ of interventional radiology.For the group of above 40 years old,the largest percentage contributions were,respectively,routine diagnostic X-ray examination 47.95％,diagnostic CT examinations 65.41％,and interventional radiology 75.64％.All types of medical X-ray examinations are concentrated in the tertiary and secondary hospitals.Based on this survey,the examination frequencies for 2016 in Guangdong were estimated to be,respectively,diagnostic X-ray examination 699 examinations per 1 000 population and CT diagnostic 231 examinations per 1 000 population,with the total of 992 examinations per 1 000 population.Conclusions This survey was completed to a limited degree and less investment.The results showed that the diagnostic radiology in Guangdong province is developing with increased frequencies,with wide varieties of X-ray examination types in the tertiary and secondary hospitals.Relevant competent defpartments should pay attention to strengthening the radiation protection of examined individuals and actively providing guidance on the correct and rational applicc ation of diagnostic radiology so as to achieve profit and avoid disadvantages.
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Objective@#To investigate the distribution of gross α and gross β radioactive levels in drinking raw water from different regions of Guangdong province, and to establish the radioactive level base line value in raw water.@*Methods@#The samples from 191 drinking water sources in use in Guangdong province were collected in rainy season and dry season, respectively, and determined and analyzed under the standard examination method for drinking water-radiological parameters (GB/T 5750.13-2006). The levels of gross α and gross β radioactivity were evaluated under the standard for drinking water quality (GB 5749-2006).@*Results@#A total of 377 raw water samples were taken, including 189 samples in rainy season and 188 samples in dry season, in which 186 samples were matched between rainy season and dry season. In dry season, the gross α levels ranged from 0.008 Bq/L to 0.582 Bq/L, averaged at (0.034±0.060) Bq/L, while the gross β levels ranged from 0.014 Bq/L to 0.637 Bq/L, averaged at (0.108±0.091) Bq/L. In rainy season, the gross α levels ranged from 0.008 Bq/L to 0.402 Bq/L, averaged at (0.045±0.064) Bq/L, while the gross β levels ranged from 0.014 Bq/Lto 0.848 Bq/L, averaged at (0.125±0.128) Bq/L. The gross α and gross β radioactivity levels of other samples were much lower than the guidance values in the national radioactivity standards on drinking water radioactivity, except for a sample from Shanwei area. The gross α and gross β radioactivity levels in the rainy season were higher than in the dry water season, and the gross α radioactivity levels in the rainy season were significantly higher than in the dry water season. There were significant differences in gross α and gross β radioactivity levels in rainy(Frainy season=1.819, 2.709, P<0.05) and dry season (Fdry season=1.985, 8.461, P<0.05)in different water systems, and the levels of gross α and gross β radioactivity in the rivers in western Guangdong were the highest. The gross α and gross β radioactivity levels of groundwater in rainy season were higher than in river water and lake water, and the gross α and gross β radioactivity levels in river water were higher than in lake and reservoir water, with the statistically significant differences(Ftotal α=39.323, Ftotal β=25.911, P<0.05), the gross α and gross β radioactivity levels in dry season were higher than in river water and lake water, with the statistically significant difference(Ftotal α=11.520, Ftotal β=28.435, P<0.05). The highest radioactivity levels is in groundwater, followed by river water, and the lowest is in lake and reservoir water.@*Conclusions@#The natural radioactivity background levels in drinking raw water in Guangdong province is lower than the limit value on drinking water stipulated by our country. The radioactivity levels in raw water in western Guangdong is significantly higher than in other water systems, and the radioactivity level in river water is also significantly higher than in lake and reservoir water.
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Objective To survey the basic situation of diagnosis and treatment in clinical nuclear medicine across Guangdong province,evaluate the risks of exposure to the radiation workers and public and explore the countermeasures to control radiation exposre.Methods A survey team was set up to survey,by filling questionnaires,the basic information on nuclear medicine practices for workers,equipment,radionuclide,frequency and dose to workers and radiation protection measures.Results A total of 71 nuclear medicine institutions was involved in the survey with 733 radiation workers in 2016 in Guangdong.The average annual effective dose to nuclear medicine workers was (0.55±0.66) mSv per year.The total pieces of nuclear medical equipment was up to 189 in 2016 including 59 SPECT/CT scanners (5 SPECT),28 PET/CT scanners and 54 thyroid scanners.Total activity of 1.15× 10s MBq in radiopharmaceuticals was used in 325 903 examinations and treatments with the number of frequency of 2.97 examinations per 1 000 population.Concluions There have been a rapid progress in practice of nuclear medicine over the past 20 years in Guangdong province with departments of nuclear medicine set up in 18 of 21 cities.Compared with 1998,the activity in radiopharmaceuticals used has increased by 414％ in 2016 and the number of frequency of examination and treatment has increased by 111％.The rapid expansion of nuclear medicine practice has also caused potential risks of radiation to the public and environment.
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OBJECTIVE: To explore the status of occupational stress and its influencing factors in medical radiation workers using two occupational stress measurement models. METHODS: A total of 632 medical radiation workers from Guangdong Province were selected as the study subjects using cluster sampling method. Chinese version of Job Content Questionnaire and Effort Reward Imbalance Questionnaire were used to assess occupational stress with job demand-control( JDC) and effort-reward imbalance( ERI) models. RESULTS: The rate of occupational stress in the study subjects was 43. 8%( 277/632) using the JDC model. The rate of occupational stress was 38. 6%( 244/632) using the ERI model. The multivariate logistic analysis results showed that the risk of JDC occupational stress was higher in workers with more than 8 hours work daily and more than 40 hours weekly( P < 0. 01). The risk of ERI occupational stress was higher in the workers with age of30. 0-40. 0,public medical institutions,daily work more than 8 hours and weekly work more than 40 hours( P < 0. 01).CONCLUSION: Under the two theoretical models,medical radiation workers have a certain degree of occupational stress. The age,medical institution type,daily and weekly work hours are the main factors affecting occupational stress.