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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 investigate the exposure level of ionizing radiation in medical radiation workers in Guangdong province, as well as their abnormality in the lens of the eye, and to analyze associated influence factors.Methods:In this study, 1 501 radiation workers from 60 hospitals were selected by using convenient sampling method for retrospecotive analysis of absorbed doses ( DL) to the lens of the eye, health examination information and the relevant influence factors. Results:The median value M and the 25 th and 75 th percentile values ( P25, P75)of the distribution of absorbed doses were 4.86, 2.99 and 7.90 mGy, respectively. The median values for male and female were 5.14 and 3.94 mGy, respectively. The median values for the Levels I, Ⅱ and Ⅲ medical institutions were 2.95, 3.51 and 5.06 mGy, respectively. The median values were radiotherapy 4.05 mGy, radiodiagnosis 4.84 mGy, interventional radiology 5.39 mGy and nuclear medicine 6.71 mGy, as well as nurses 3.48 mGy, physicians 5.03 mGy and technologists 5.03 mGy, respectively. There were statistically significant differences in dose distribution for different gender, age, length of radiation service, age at the beginning of radiation exposure, level of medical institution, occupational category and post ( Z=-6.72, H=389.64, 511.17, 70.29, 53.29, 49.06, 39.89, P<0.05). The detectable rate for increased cortical density of lens was 22.45% (337/1 501) and for lens turbidity was 8.19% (123/1 501). The detectable rate of increased cortical density showed a linear increasing trend with the increase in age, age of radiation service, age at the beginning of exposure to radiation, level of medical institution and dose ( χ2=366.36, 313.77, 15.18, 21.61, 92.13, P<0.05). The detectable rate of lens opacity increased linearly with the increase in age, length of radiation service, level of medical institution and dose( χ2=69.64, 67.65, 67.65, 37.37, P<0.05), and decreased linearly with the increase in age at the beginning of radiation exposure ( χ2=4.25, P<0.05). Logistic regression analysis showed that age was the influencing factor of increased cortical density ( χ2=165.98, P<0.05), and the risk of cortical densification increased with age ( OR=1.33, 95% CI: 1.27-1.39). Age, length of radiation service and occupation were the influencing factors of lens opacity ( χ2=25.78, 4.99, 6.88, P<0.05). The risk of lens opacity increased with age ( OR=1.17, 95% CI: 1.10-1.24). The risk of lens opacity increased with age of radiation service ( OR=1.06, 95% CI: 1.01-1.12). The risk of ocular opacity was higher in interventional radiology than that in diagnostic radiology, radiotherapy and nuclear medicine ( OR=2.59, 95% CI: 1.27-5.25). Conclusions:Long-term exposure to low dose ionizing radiation has a certain correlation with the abnormal lens detectable rate of medical radiation workers. Age, length of radiation service and occupation are the influencing factors of lens opacity.
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Objective:To explore the investigation level of individual monitoring for medical radiation workers.Methods:Monitoring and analysis of individual doses to the medical radiation workers in Guangdong province were performed, from 2016 to 2019, by the Individual Dose Monitoring Department of Guangdong Provincial Hospital for Occupational Disease Prevention and Control.Results:The numbers of monitored workers were diagnostic radiology 53 674, dental radiology 2 563, nuclear medicine 5 001, radiotherapy 16 687, interventional radiology 22 272 and others 2 087 from 2016 to 2019, of which the number of individuals with doses in excess of investigation level 1.25 mSv, were 76, 6, 18, 28, 133 and 2 respectively. The non-real doses made up 67.1 %, 100 %, 55.6 %, 82.1 %, 76.7 % and 100 % of their respective totals. Their 99th percentile doses P99 were 0.37, 0.39, 0.67, 0.35, 0.54 and 0.30 mSv, and the average periodic dose equivalent were 0.07, 0.06, 0.11, 0.06, 0.07 and 0.05 mSv respectively, indicating a statistically significant difference existing in the average annual effective dose between groups ( Z=-26.139--2.681, P<0.001). Conclusions:Due to non-reality of doses in excess of investigation levels and high labor cost, it is suggested to currently use 0.40 mSv per 3 months as investigation level for diagnostic radiology, dental radiology, radiotherapy and others, and 0.70 mSv per 3 months as for nuclear medicine and interventional radiology.
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OBJECTIVE: To explore the effect of long-term low-dose ionizing radiation exposure on arterial vascular elasticity in female residents. METHODS: A cluster random sampling method was used,95 female residents in 2 regions with high external γ radiation dose rate in the high radiation background area( HBRA) in Yangjiang City were selected as the HBRA group,and 96 female residents from the control area( CA) in Enping City were chosen as the CA group. The height,body mass,waist circumference,hip circumference and blood pressure were measured in individuals of these two groups. The fasting blood samples of elbow vein were collected to measure high-density lipoprotein cholesterol( HDL-C),low-density lipoprotein cholesterol( LDL-C),triglycerides( TG) and blood glucose. The cardio-ankle vascular index( CAVI) was measured using the blood pressure and pulse check device. RESULTS: The CAVI of the CA and HBRA groups were( 8. 09 ±1. 03) and( 8. 35 ± 1. 60) m/s,respectively. The abnormal rates of CAVI were 25. 00% and 29. 47%,respectively. The results of multiple linear regression analysis showed that after adjustment for age,HDL-C,LDL-C,TG,hypertension,abnormal glucose metabolism and abdominal obesity,the CAVI adjustment mean values of the CA and HBRA groups were8. 19 and 8. 25 m/s,respectively. The HBRA group was about 0. 73% higher than the CA group,but the difference was not statistically significant( standardized partial regression coefficient = 0. 021,P > 0. 05). After matching age of both groups,the difference of the adjusted mean of CAVI between the two groups was not statistically significant( P > 0. 05).CONCLUSION: Long-term low-dose radiation exposure is not associated with atherosclerosis in female population.
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Objective@#To investigate the molecular evolution characteristics of human coronavirus (HCoV) subtypes in patients with fever and respiratory tract infection in Guangzhou from 2010 to 2012.@*Methods@#Partial fragments of NP, RdRp and S genes of HCoV-OC43, HCoV-229E and HCoV-NL63 positive samples were amplified by RT-PCR and sequencing. Bioinformatics software, including Bio-edit, Mega4.0 and Clustal1.83 were used for comparison and analysis of NP, RDRp and S gene sequences. Molecular evolutionary tree of different gene regions of HCoV-OC43, HCoV-229E and HCoV-NL63 were built.@*Results@#No remarkable variation or recombinant strain of HCoV-OC43, HCoV-229E and HCoV-NL63 was found in Guangzhou during 2010—2012. The HCoV-OC43 substrains were genetically closest to the strains found in Belgium and Hong Kong (GenBank accession number JN129834 and AY903460). HCoV-229E substrains were genetically closest to those found in Amsterdam (GenBank accession number JX503060) and HCoV-NL63 most genetically close to those in Amsterdam and Beijing (GenBank accession number JX104161 and DQ445911). The NP and RDRp genes of all subtypes were highly conserved, while S gene was more variable.@*Conclusions@#There were at least 3 substrains of HCoV-OC43, HCoV-229E and HCoV-NL63 epidemic in Guangzhou during 2010—2012, and no remarkable variation or recombinant viral strain was found. The NP and RDRp genes of all subtypes were highly conserved and can be used in virus detection, while S gene was more variable and suitable for phylogenetic and variation study.
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Objective To observe the effects of anisodamine on levels of neurotensin in the plasma and lung homogenate during acute lung injury in rats after brain trauma.Methods The level of neurotensin in the plasma and lung organizes after brain trauma and that after administration with anisodamine were determined by radioimmunoassay(RIA).Results Level of neurotensin in the plasma and lung homogenate of rat with brain trauma was obviously higher than that in normal control group but significantly lower than that in anisodamine group.Conclusion Increase of neurotensin in the plasma and lung homogenate may be due to causing lung injury after brain trauma.Anisodamine can exert protective effect on acute brain injury by reducing level of neurotensin in in the plasma and lung homogenate.