Cancer mortality in workers at risk of occupational exposure to ionizing radiation in a company in the nuclear sector headquarters in São Paulo / Mortalidade por câncer em trabalhadores com risco de exposição ocupacional à radiação ionizante em empresa do setor nuclear sediada em São Paulo

ABSTRACT Objective: To compare cancer mortality among workers exposed to gamma and X radiation and the general population of the city of São Paulo, as well as that of the subgroup monitored with those not monitored for gamma and X radiation in a work unit with ionizing radiation based in the city of São Paulo. Methods: Between 2016 and 2021, a retrospective open cohort study was carried out with workers who were employed from 08/31/1956 to 12/31/2016 based on data collected at the company and in official institutions. Standardized mortality ratios (SMR) were calculated by sex, age and calendar period of cancers grouped according to type, risk factor and organ system in two analyses: in the external analysis, the mortality of the study population was compared with that of the general population of the city of São Paulo; In the internal analysis, the mortality of the monitored subgroup was compared with that of the subgroup not monitored for gamma and X radiation. Results: The external mortality analysis showed SMR=0.224 (95%CI 0.208-0.240) and the healthy worker effect, while the internal mortality analysis showed SMR=0.685 (95%CI 0.618-0.758). Conclusion: This study showed lower cancer mortality among exposed workers when compared to mortality in the general population and the healthy worker effect. Among workers monitored for gamma and X radiation, cancer mortality was lower when compared to those not monitored.

RESUMO Objetivo: Comparar a mortalidade por câncer entre trabalhadores expostos à radiação gama e X e a população geral do município de São Paulo, bem como a do subgrupo monitorado com o não monitorado para radiação gama e X em uma unidade de trabalho sediada no município de São Paulo. Métodos: Entre 2016 e 2021 foi realizado estudo de coorte aberta retrospectiva com trabalhadores que tiveram vínculo empregatício desde 31/08/1956 até 31/12/2016 a partir de dados coletados na empresa e em instituições oficiais. Foram calculadas as razões de mortalidade padronizadas (RMP) por sexo, idade e período calendário de cânceres agrupados segundo o tipo, o fator de risco e o sistema orgânico em duas análises: na análise externa, comparou-se a mortalidade da população de estudo com a da população geral do município de São Paulo; já na análise interna, comparou-se a mortalidade do subgrupo monitorado com a do subgrupo não monitorado para radiação gama e X. Resultados: A análise externa de mortalidade mostrou RMP=0,224 (IC95% 0,208-0,240) e o efeito do trabalhador sadio, enquanto a análise interna de mortalidade mostrou RMP = 0,685 (IC95% 0,618-0,758). Conclusão: Este estudo mostrou menor mortalidade por câncer entre os trabalhadores expostos quando comparada com a mortalidade da população geral e o efeito do trabalhador sadio. Entre os trabalhadores monitorados para radiação gama e X, a mortalidade por câncer foi menor quando comparada com a dos não monitorados.

Association between deacetylase Sirtuins and radiation-induced liver disease / 临床肝胆病杂志

Radiation-induced liver disease （RILD）， also known as radiation hepatitis， is subacute liver injury induced by radiation. As the focus of senescence-related studies， the deacetylase family Sirtuins （SIRTs） have the molecular functions including DNA repair and chromatin regulation， which makes SIRTs a hub for regulating genome and epigenome stability. Radiation-induced hepatic DNA damage and reaction is the primary physiological and pathological process of RILD， which is similar to the function of SIRTs. This article briefly introduces the structure and function of the SIRTs protein family， elaborates on the basic concepts and progress of the physical physiology of radiation therapy， discusses the internal relationship between SIRTs and RILD from the perspective of radiobiology， and points out the possibility of SIRTs as a target for the prevention and treatment of RILD.

Dimethyl fumarate inhibits NLRP3/AIM2 inflammasomes to prevent spleen radiation injury ZHANG / 中国药理学通报

Aim To investigate the protective effect of dimethyl fumarate on spleen injury induced by gamma radiation in mice and the related mechanism. Methods C57BL/6 mice were randomly divided into the blank control group, radiation model group and DMF administration group, which were administered once at 12 h before irradiation and once at 0. 5 h, 12 h, 24 h and 48 h after irradiation. The 30-day survival rate, body weight and pathological injury of spleen were measured after a one-time total body irradiation of Co 7 rays (8 Gy). TUNEL staining was used to detect apoptosis of spleen cells. Enzyme-linked immunoassay ( ELISA) was applied to detect the contents of TNF-a, IL-1 p, IL-6, IL-18, NLRP3 and AIM2 in spleen. Western blot test and immunofluorescence staining test was employed to verify the changes of NLRP3 and AIM2 contents in spleen tissue after irradiation. Results DMF could obviously improve the survival rate of irradiated mice, improve the weight loss of irradiated mice, re-duce the pathological injury of spleen, and inhibit the apoptosis of spleen cells after irradiation. ELISA results showed that DMF could significantly inhibit the increase of spleen inflammatory cytokines TNF-a, IL-lp, IL-6, IL-18 and inflammasome components NL-RP3 and AIM2 induced by irradiation. Western blot and tissue immunofluorescence staining also confirmed that DMF could inhibit the increase of NLRP3 and AIM2 inflammasome protein levels caused by irradiation. Meanwhile, NLRP3 agonist and AIM2 agonist could antagonize the radiation protection effect of DMF on spleen cells. Conclusion DMF can ameliorate spleen injury of Co 7-ray injured mice, and its mechanism is closely related to NLRP3/AIM2 inflamma-somes, which can be used as a potential protective drug for radiation injury.

Effects of ionizing radiation on blood pressure and electrocardiography among healthcare workers in department of cardiovascular diseases / 中国辐射卫生

Objective To examine the effects of ionizing radiation on blood pressure and electrocardiography among healthcare workers in department of cardiovascular diseases, and to provide a reference for formulating the protective interventions against radiation exposure. Methods A total of 127 healthcare workers with radiation exposure in the Department of Cardiovascular Diseases of The 904th Hospital of the Joint Logistics Support Force of the PLA from 2018 to 2022 were included in the observation group. Meanwhile, 127 age- and gender-matched healthcare workers without radiation exposure in the same department during the same study period were included in the control group. The systolic blood pressure, diastolic blood pressure, heart rate, and the detection rates of hypertension and abnormal electrocardiography were compared between groups. Results There were no significant differences between groups in mean age (t = 0.77, P > 0.05), sex (χ2 = 0.02, P > 0.05), prevalence of smoking (χ2 = 0.28, P > 0.05), and alcohol consumption (χ2 = 0.02, P > 0.05). There were significant differences between the observation and control groups in systolic blood pressure [(127.77 ± 15.43) mmHg vs. (111.23 ± 19.10) mmHg; t = 4.21, P < 0.05], diastolic blood pressure [(79.32 ± 8.23) mmHg vs. (69.91 ± 10.21) mmHg; t = 4.09, P < 0.05], prevalence of hypertension [17.32% (22/127) vs. 8.66% (11/127); χ2 = 4.21, P < 0.05], heart rate [(81.10 ± 11.27) beats/min vs. (70.45 ± 10.55) beats/min; t = 4.33, P < 0.05], and abnormal rate of electrocardiography [21.26% (27/127) vs. 10.24% (13/127); χ2 = 5.82, P < 0.05]. Conclusion Ionizing radiation affects blood pressure and electrocardiography among healthcare workers in department of cardiovascular diseases. The prevention and monitoring of radiation exposure and occupational physical examination should be improved among healthcare workers with exposure to radiation in the department of cardiovascular diseases, with aims to reduce the hazard of radiation exposure and protect the health of healthcare workers.

Effects of fractionated low-dose ionizing radiation in the induction of EA.hy926 cell senescence / 中国辐射卫生

Objective To investigate the mechanism of fractionated low-dose ionizing radiation (LDIR) in the induction of EA.hy926 cell senescence. Methods EA.hy926 cells were irradiated with X-ray at 0, 50, 100, and 200 mGy × 4, respectively, and cultured for 24, 48, and 72 h. Several indicators were measured, including the levels of cellular senescence-associated β-galactosidase (SA-β-gal) staining, mRNA levels of senescence-associated cell cycle protein-dependent kinase inhibitor genes CDKN1A and CDKN2A, reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and phosphorylated H2A histone family member X (γ-H2AX). Results After 4 fractionated LDIR, compared with the control group, the treatment groups showed increased nucleus area, blurred cell edge, and increased SA-β-gal positive area (P < 0.05) at 24, 48 and 72 h. After 4 fractionated LDIR, the mRNA level of CDKN1A increased in the 100 and 200 mGy × 4 groups at 24 and 48 h (P < 0.05), and CDKN2A mRNA level increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). The fluorescence intensity of ROS increased in treatment groups at 24, 48, and 72 h after 4 fractionated LDIR (P < 0.05). After 4 fractionated LDIR, the T-AOC level increased in the 100 and 200 mGy × 4 groups at 24 h (P < 0.05), and T-AOC level increased in all treatment groups at 48 and 72 h (P < 0.05). After 4 fractionated LDIR, γ-H2AX fluorescence intensity increased in all treatment groups at 24 h (P < 0.05), and the fluorescence intensity increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). Conclusion Fractionated LDIR can induce cellular senescence in EA.hy926 cells by impacting the cellular oxidation-antioxidation and oxidative damage levels, and the effects were relatively evident at 100 and 200 mGy.

El conocimiento y cumplimiento de las normas de protección sobre la radiación ionizante en una clínica dental docente

Introducción: El uso de radiografías como elemento complementario para el diagnóstico es fundamental para la práctica profesional de todo cirujano dentista. Por tanto, es importante conocer no solo los beneficios de la radiología oral y los fundamentos de protección radiológica, sino también determinar su nivel de aplicación o la adherencia frente al cumplimiento de los aspectos normativos que regulan el uso de la radiación ionizante en odontología. Objetivo: Relacionar el conocimiento sobre los cuidados en radiología bucal, las ventajas y los peligros en la toma de radiografías con el cumplimiento de las normas de protección radiológica y radiación ionizante en estudiantes de odontología de una clínica dental docente. Métodos: La población de estudio estuvo constituida por 180 estudiantes del cuarto año de la carrera de odontología, que emplearon los equipos radiológicos en la clínica docente asistencial durante los años 2019 (segundo semestre) y 2020 (primer trimestre). Se tomó como muestra representativa a 104 estudiantes, incorporados al estudio mediante muestreo aleatorio simple. Se aplicaron dos instrumentos de recolección de datos, uno para evaluar el conocimiento (cuestionario) y otro para verificar el cumplimiento de normas (lista de chequeo) sobre la protección radiológica y el diagnóstico por imágenes en la práctica odontológica. Para el análisis estadístico se aplicó la prueba estadística chi cuadrado con un nivel de significancia del 95 %. Resultados: No se encontró relación estadísticamente significativa (p = 0,30) entre el conocimiento teórico sobre la protección radiológica y el diagnóstico por imágenes, respecto el cumplimiento de las normas que regulan su aplicación (p > 0,05). El 90 % de participantes tienen conocimientos entre regulares y excelentes. Sin embargo, solo el 32 % cumple las normas técnicas de protección sobre radiación ionizante en su práctica clínica. Conclusión: Los estudiantes de odontología tienen suficiente conocimiento sobre protección radiológica y diagnóstico por imágenes. Sin embargo, este conocimiento no se refleja en prácticas adheridas a las normas.

Introduction: The use of radiographs as a complementary element for diagnosis is fundamental to the professional practice of every dental surgeon. Therefore, it is important to know not only the benefits of oral radiology and the fundamentals of radiological protection, but also to determine their level of application or adherence to compliance with the regulatory aspects that regulate the use of ionizing radiation in dentistry. Objective: To relate the knowledge of oral radiology care, the advantages and dangers in taking radiographs with compliance with the norms of radiological protection and ionizing radiation in dental students of a dental teaching clinic. Methods: The study population consisted of 180 fourth year dental students who used the radiological equipment in the teaching dental clinic during 2019 (second semester) and 2020 (first quarter). A representative sample of 104 students was taken, incorporated into the study by simple random sampling. Two data collection instruments were applied, one to evaluate knowledge (questionnaire) and the other to verify compliance with standards (checklist) on radiological protection and diagnostic imaging in dental practice. For the statistical analysis the chi-square statistical test was applied with a significance level of 95 %. Results: No statistically significant relationship was found (p = 0.30) between theoretical knowledge of radiological protection and diagnostic imaging with respect to compliance with the norms that regulate its application (p > 0.05). Ninety percent of participants have fair to excellent knowledge. However, only 32 % comply with the technical norms of ionizing radiation protection in their clinical practice. Conclusion: Dental students have sufficient knowledge of radiation protection and diagnostic imaging. However, this knowledge is not reflected in practices that adhere to the standards.

Oral Long oil for prevention and treatment of radiation enteritis / 药学学报

Radiation enteritis (RE) is a common syndrome in the radiotherapy of abdominal and pelvic malignant tumors, heavy influencing living quality, but no specific clinical regimens are available. Long oil (LO) is composed of the fat components from cuttlebone, safflower, walnut oil and rapeseed oil and has been clinically used for wound healing. In this study, oral LO was applied for the prevention and treatment of RE and the mechanisms were explored. Animal experiments were approved by the Ethics Committee of the Beijing Institute of Radiation Medicine, Academy of Military Medical Sciences, and the experiments were conducted in accordance with relevant guidelines and regulations. An RE mouse model was established after single whole abdominal γ-ray radiation of 13 Gy. LO (8 mL·kg-1) was intragastrically administered to the mice 1 h pre-radiation. Compared to the models, the mice of the LO group had more regenerated intestinal crypts and longer villus on day 3.5, and remarkable increase in the abundance of gut microbiota on day 7, especially the amounts of probiotics including Eubacterium and Lactobacillus. Moreover, the mice of the LO group showed longer total movement distance, shorter immobility time, and higher speed than the model mice on day 7. On day 14, the mice of the LO group showed the high descending of proinflammatory factors including tumor necrosis factor-α and interleukin-6, close to the normal levels. Therefore, oral LO can alleviate the inflamed syndromes of RE and improve the repair of damaged intestinal tissues. Moreover, the mice of the LO group had highly low permeability of intestinal mucosa according to the fluorescence labeling experiment, which was close to the normal level. Oral LO can protect intestine mucosa and prevent RE by modification of the intestinal microenvironment, alleviation of the inflammatory response, and promotion of tissue repair.

Perfil sociodemográfico e situação de saúde dos pacientes expostos ao Césio 137 em Goiânia / Sociodemographic profile and health situation of patients exposed to Cesium 137 in Goiânia

Este trabalho teve por objetivo analisar os aspectos sociodemográficos e da situação de saúde dos indivíduos expostos ao Césio 137, que constam com cadastro ativo no Sistema de Informação ao Radioacidentado (SISRAD) do Centro de Assistência aos Radioacidentados (CARA). Métodos: Trata-se de um estudo descritivo, com análise transversal, realizado no período de outubro de 2019 a fevereiro de 2020 e que contempla dados registrados desde o ano de 1987. O público-alvo da pesquisa consistiu em indivíduos expostos de forma direta e indireta ao Césio 137 na cidade de Goiânia-Goiás, e que se encontram devidamente cadastrados no CARA. Levou-se em consideração aspectos sociodemográficos, a fim de construir o perfil dos pacientes. Realizado esse processo, procedeu-se à classificação e distribuição dos pacientes, através de critérios como a forma de contato e a dose de exposição. O levantamento de dados foi executado pela análise dos prontuários no SISRAD. Resultados e Conclusões: nos grupos mais jovens não foram identificados cânceres precoces ou malformações nos Grupos NGI e NGII, mas existem relatos que conflitam com as declarações de óbitos dos grupos GI e GII, o que trouxe dificuldades para uma análise estratificada e detalhada. As doenças psíquicas, apresentam maior prevalência, seguidas de causas associadas a hipertensão e a diabetes. Verificou-se a importância da análise de saúde dos radioacidentados como ferramenta de planejamento, preparação e avaliação dos grupos de risco

This study aimed to analyze the sociodemographic aspects and the health situation of individuals exposed to Cesium 137, who have an active record in the Information System for Radio Accidents (SISRAD) of the Assistance Center for Radio Accidents (CARA). Methods: This is a descriptive study, with cross-sectional analysis, carried out from October 2019 to February 2020 and which includes data recorded since 1987. The target audience of the research consisted of individuals exposed directly and indirect exposure to Cesium 137 in the city of Goiânia-Goiás, and who are duly registered with the CARA. Sociodemographic aspects were taken into account in order to build the profile of patients. Once this process was completed, the patients were classified and distributed using criteria such as the form of contact and the dose of exposure. Data collection was carried out by analyzing the medical records in SISRAD. Results and Conclusions: In the younger groups, no early cancers or malformations were identified in Groups NGI and NGII, but there are reports that conflict with the death certificates of groups GI and GII, which brought difficulties for a stratified and detailed analysis. Mental illnesses are more prevalent, followed by causes associated with hypertension and diabetes. The importance of analyzing the health of radio-accidents as a tool for planning, preparing and evaluating risk groups was verified

Thyroid abnormalities and influencing factors in medical radiology workers in Guangdong Province / 环境与职业医学

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.

Role of TLR4/NF-κB signaling pathway in hydrogen-rich water improving cognitive impairment induced by ionizing radiation in rats / 环境与职业医学

Background In the process of radiotherapy, when radiation kills tumor cells, it inevitably damages normal tissue cells. Objective To investigate the role of Toll-like receptor 4 (TLR4)/nuclear factor−kappa B (NF-κB) signaling pathway in the improvement of cognitive impairment induced by ionizing radiation by hydrogen-rich water before and after whole brain irradiation in rats. Methods Fifteen male SD rats were randomly divided into three groups: control group, irradiated group (IR group), and hydrogen-rich water intervention group (IR+HRW group), with 5 rats in each group. The control group was not irradiated, but was given purified water (20 mL·kg−1) by gavage every day, while the IR group and the IR+HRW group were irradiated with a single dose of 20 Gy. Three days before, 10 min before, and 30 days after irradiation, purified water/hydrogen-rich water (20 mL·kg−1) was given by continuous gavage every day. The general condition of the rats was observed every day, and the body weight were measured on the 7th, 14th, 21st, and 30th days after irradiation. On the 30th day after irradiation, the learning and memory ability of the rats was tested by Morris water maze; the pathological changes of hippocampus were detected by hematoxylin-eosin (HE) staining after sacrificing the rats; the contents of glutathione (GSH), malondialdehyde (MDA), interleukin-1β (IL-1β), and hydroxyl radicals in brain tissues were detected by enzyme linked immunosorbent assay (ELISA); the mRNA and protein expression levels of TLR4, NF-κB, NOD-like receptor pyrin domain 3 (NLRP3), and cysteinyl aspartate specific proteinase 1 (Caspase 1) were detected by quantitative real-time PCR (qRT-PCR) and Western blotting in the hippocampus of rats. Results After irradiation, the rats in the IR group showed symptoms such as head hair removal and salivation, while the symptoms of the rats in the IR+HRW group were milder. No animal died in the control and the IR+HRW groups, while one rat died in the IR group. From day 14 to day 30 after irradiation, the body weight of the rats in the IR+HRW group tended to be higher than that in the IR group, but the difference was not statistically significant (P>0.05). The Morris water maze results showed that the escape latency of the IR+HRW group was shortened compared with that of IR group from day 1 to day 5 except day 3, but the difference was not statistically significant (P>0.05). For the rats in the IR+HRW group, it took less time to reach the original location of the platform after removing the platform on day 6 and the number of crossing the platform and the residence time in the original platform quadrant increased (P<0.05). The HE staining showed that the number of hippocampal cells in the IR+HRW group was slightly reduced and arranged neatly, without obvious nuclear hyperchromatic and pyknotic phenomenon. The ELISA results showed that the MDA and hydroxyl radical levels were decreased in the IR+HRW group compared with the IR group (P<0.05), the GSH content was increased, and the IL-1β concentration was decreased, but the differences were not statistically significant (P>0.05). The results of qRT-PCR showed that the mRNA expression levels of TLR4 and Caspase 1 in the hippocampus of the IR+HRW group were decreased compared with the IR group (P<0.05), and the mRNA expression levels of NF-κB and NLRP3 were also decreased, but the differences were not statistically significant (P>0.05). The results of Western blotting showed that the expression levels of TLR4 and Caspase 1 protein in the hippocampus of the IR+HRW group were decreased compared with the IR group (P<0.05), and the expression levels of NF-κB p65 and NLRP3 protein were also decreased, but the differences were not statistically significant (P>0.05). Conclusion Hydrogen-rich water can improve cognitive impairment induced by ionizing radiation in rats, and its mechanism may be related to regulating TLR4/NF-κB signaling pathway, inhibiting inflammatory factors, and attenuating oxidative stress.

Effect of hydrogen-rich water on brain injury in rats with acute radiation based on PI3K/AKT/Caspase-9 signaling pathway / 环境与职业医学

Background At present, radiation therapy is widely used in clinical treatment of tumors. However, while radiation therapy damages tumor cells, it also injures surrounding normal tissues. Studies have shown that hydrogen is a potential radiation-protective agent. Objective To investigate the neuroprotective mechanisms of hydrogen-rich water activating phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/cysteinyl aspartate specificproteinase-9 (Caspase-9) signaling pathway in acute radiation-induced brain injury. Methods Forty male SD rats were randomly divided into four groups: control group, irradiation only group (IR), high-dose hydrogen-rich water intervention group (IR+HHRW), and low-dose hydrogen-rich water intervention group (IR+LHRW), 10 rats in each group. Except for the control group, animals in each group received a single 20 Gy whole brain irradiation. Animals in all groups were gavaged once a day from 3 d before irradiation to 7 d after irradiation, pure water (20 mL·kg−1) was given to the control and the IR groups, and hydrogen-rich water (20 mL·kg−1, 10 mL·kg−1) was given to the IR+HHRW and the IR+LHRW groups. After 7 d of intervention, 5 rats in each group were selected for the Morris water maze experiment for behavioral evaluation. Autopsies were conducted after anesthesia for the remaining animals and blood samples were collected for hematological analysis. Rat brains were harvested for TUNEL staining to observe neuronal apoptosis. HE staining was performed to observe histopathological changes, enzyme-linked immunosorbent assay was adopted to detect oxidative stress-related indicators, and real-time PCR and Western blotting were used to measure the expressions of PI3K/AKT/Caspase-9 pathway-related genes and proteins. Results The body weight of rats receiving irradiation decreased after 7 d of irradiation compared with the control group (P<0.05), and the symptoms such as arched back and malaise occurred to varying degrees, and the symptoms of rats in the IR+HHRW group were significantly milder than those in the IR group. The behavioral test results showed that the escape latency of rats in the IR+HHRW group or the IR+LHRW group was shorter than that in the IR group from day 2 to day 5 (P<0.05), and it took less time for rats in the IR+HHRW group to reach the original position after removing the platform on day 6 (P<0.05). The hematological test results showed that red blood cell (RBC) count, hemoglobin (HGB) level, and white blood cell (WBC) count were significantly decreased in the IR group (P<0.05), and the changes in the IR+HHRW group were improved (P<0.05). The HE staining results showed that the number of abnormal nerve cells, broken and dissolved nuclei, and the degree of damage in the IR+HHRW group were significantly reduced than those in the IR group. The results of oxidative stress evaluation showed that the ability of the IR group to inhibit free radicals decreased, the level of malondialdehyde (MDA) increased (P<0.01); the MDA level decreased after LHRW intervention (P<0.05); the SOD activity was elevated after HHRW intervention (P<0.05). The TUNEL staining results showed that the apoptosis signals in the IR+HHRW group were sparser than those in the IR group (P<0.05). The real-time PCR results showed that compared with the IR group, the mRNA expression levels of PI3K and AKT in the IR+HHRW group and the IR+LHRW group increased (P<0.05), while the mRNA expression levels of Cytc and Caspase-9 decreased (P<0.05). The Western blotting results showed that compared with the IR group, the phospho-AKT (pAKT) protein expression level in the IR+HHRW group increased significantly (P<0.05), while the expression of Caspase-9 and Cytc proteins decreased significantly (P<0.05). Conclusion Hydrogen-rich water can significantly reduce inflammation and oxidative stress caused by acute irradiation-induced brain injury, and decrease neuronal apoptosis. The mechanism may be related to the PI3K/AKT/Caspase-9 signaling pathway.

Analysis of occupational health examination results of radiation workers in Dezhou, China / 中国辐射卫生

Objective To investigate the occupational health status of radiation workers in Dezhou, China, explore the effects of low-dose ionizing radiation on the health of radiation workers, and provide a basis for improving the health of radiation workers. Methods A total of 1101 radiation workers in Dezhou who underwent occupational health examination in 2021 were selected. The effects of physical examination type, type of work, sex, length of service, and age on the health status of radiation workers were compared and analyzed. Results The abnormal rates of abdominal color Doppler ultrasound and eye lens were significantly higher in pre-post radiation workers than in radiation works (P < 0.05). The abnormal rates of eye lens increased with the length of service in radiation workers (P < 0.05). The abnormal rate of abdominal color Doppler ultrasound in male workers was higher than that in female workers, while the abnormal rates of blood routine and thyroid function were higher in female workers than in male workers (P < 0.05). Conclusion The abdominal rates of color Doppler ultrasound and eye lens are relatively high among radiation workers in Dezhou. It is necessary to improve the protection awareness and strengthen the level of radiation protection, so as to ensure the occupational health of radiation workers.

Effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes / 中华放射肿瘤学杂志

Objective:To investigate the effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes.Methods:Twenty-four C57BL/6J mice were divided into two groups by random number table method: healthy control group (control group, n=6) and irradiation group (whole liver was irradiated with a single dose of 30 Gy X-ray, n=18). Mice were sacrificed at 6, 24 and 72 h (6 mice per time point) after irradiation to obtain liver tissue and plasma samples. The contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma were measured by automatic biochemical analyzer. The prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured by automatic biochemical analyzer. Pathological changes of liver tissues were observed by hematoxylin-eosin (HE) staining. The iron deposition in liver tissues was detected by Prussian blue staining. The expression levels of 4-Hydroxynonenal (4HNE) and hepcidin in the liver were determined by immunohistochemical staining, and quantitative analysis was performed. Plasma malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC) and glutathione (GSH) content were determined by microplate reader analysis according to the kit instructions. The expression levels of transferrin receptor 1 (TfR1), p53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in the liver were measured by Western blot. Results:Compared with the control group, the plasma contents of ALT ( t=5.15, 5.47, both P<0.001) , AST at 6 and 24 h after irradiation were increased ( t=8.42, 2.50, both P<0.001), the plasma PT was prolonged ( t=3.12, P=0.011) and the APTT was shortened ( t=3.26, P=0.009) at 72 h after radiation in the irradiation group. Histopathological results showed that evident liver edema was observed at 6, 24 and 72 h after irradiation ( t=9.58, 10.09, 18.70, all P<0.001). Different degrees of iron deposition were observed ( t=8.57, 15.31, 32.11, all P<0.001). The infiltration of hepcidin positive cells was significantly increased after irradiation ( t=5.36, 13.17, 17.11, all P<0.001). The number of 4HNE positive cells was significantly increased ( t=18.86, 22.67, 9.12, all P<0.001). At the same time, ionizing radiation induced a significant increase in plasma MDA content ( t=4.36, 7.47, 8.22, all P<0.001), and a decrease in SOD ( t=4.52, 5.80, 7.60, all P<0.001), T-AOC ( t=13.24, 20.49, 24.96, all P<0.001) and GSH ( t=2.78, 6.07, 11.25, P=0.020, <0.001, <0.001), respectively. The expression level of TfR1 protein was significantly up-regulated ( t=3.46, 5.40, P=0.026, 0.006), whereas that of GPX4 protein was significantly down-regulated ( t=11.88, 30.63, both P<0.001) at 24 and 72 h after irradiation. At 6, 24 and 72 h after irradiation, the expression level of p53 protein was significantly up-regulated and maintained at a high level ( t=7.84, 4.25, 8.22, P=0.001, 0.013, 0.001), while that of SLC7A11 protein was significantly down-regulated ( t=9.29, 19.96, 9.09, all P<0.001). Conclusion:Ionizing radiation induces the ferroptosis in hepatocytes, and its mechanism may be related to the activation of p53-SLC7A11-GPX4 pathway.

Meta-analysis of the effects of low-dose ionizing radiation on the thyroid of medical radiation workers / 中华放射医学与防护杂志

Objective:To assess the effects of low-dose ionizing radiation on the thyroid of medical radiation workers.Methods:Based on the inclusion and exclusion criteria, 27 articles, involving 22 937 individuals, were screened finally from relevant literature published from 1996 to 2022. Meta-analysis was carried out using Stata 16.0 for serum levels of triiodothyronine (T 3), free triiodothyronine (FT 3), thyroid hormone (T 4), free thyroid hormone (FT 4), thyrotropin-stimulating hormone (TSH) and thyroid nodule rates. As well, subgroup analysis were carried out of thyroid function in different types of radiation workers. Results:The standardized mean difference (SMD) at T 3 and T 4 levels for radiation workers was -0.19 (-0.37, -0.01) and -0.34 (-0.38, -0.30), lower than that of control group ( Z=2.07, -16.06, P<0.05). The SMD at FT 4 levels for radiation workers was 0.22 (0.06, 0.39), higher than control group ( Z=2.61, P<0.05). The relative risk of thyroid nodules in radiation workers was 1.47 (1.19, 1.82), higher than that of control group ( Z=-3.58, P<0.05). The analysis result for subgroup showed that the SMD for T 3, T 4 and TSH levels in the interventional radiology workers were -0.29 (-0.51, -0.07), -0.31 (-0.47, -0.15) and -0.43 (-0.73, -0.13) ( Z=-2.55, -3.86, -2.82, P<0.05), respectively, and the SMD for T 4 levels in the nuclear medicine workers was -0.26 (-0.45, -0.07), which meaned a reduced risk compared to the control group ( Z=-2.70, P<0.05). Conclusions:Long-term low doses of ionising radiation may have adverse effects on thyroid hormone and thyroid nodule in radiation workers, particularly in interventional radiology workers, and attention should be focused on their radiation protection.

Mechanisms of copper transporter 1 gene in regulating radiation induced intestinal injury / 中华放射医学与防护杂志

Objective:To investigate the effects and mechanisms of copper transporter 1 (CTR1) in radiation induced intestinal injury in vitro. Methods:Human small intestinal epithelial cells (HIEC) were irradiated with 2, 4, 6, 8 Gy of X-rays and rat intestinal epithelial cells (IEC-6) were irradiated with 5, 10, 15, 20 Gy of X-rays. At 2, 4, 8, 24, and 48 h after irradiation, the expression of CTR1 was detected by Western blot assay. In some experiments, HIEC and IEC-6 cells were transfected with CTR1 shRNA and then exposed to X-rays. Copper levels were detected by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The radiosensitivity of cells was verified by colonogenic assay, the cellular reactive oxygen species (ROS) level and DNA damage were detected to further explore the related mechanism. In addition, Western blot was applied to detect the expressions of antioxidants and cuproptosis associated proteins in enterocytes after silencing CTR1 or irradiation.Results:The expression of CTR1 was increased by X-ray irradiation in a dose-dependent manner ( t=3.53, 3.45, 6.37, 11.11, 11.13, P<0.05). CTR1 expression was successfully diminished by CTR1 shRNA adenovirus vectors. According to the survival curves, the enhancement ratios of the radiosensitivity of HIEC and IEC-6 cells with CTR1 knocking-down were 1.146 and 1.201, respectively. Radiation-induced copper accumulation was alleviated after CTR1 silencing in IEC-6 cells ( t=3.10, P<0.05). At 0.5 h after irradiation, the ROS production in the CTR1 knockdown group was significantly lower than that in the control group ( t=5.23, 2.96, P<0.05). At 1 h after irradiation, the protein expression of γ-H2AX in the CTR1 knockdown group was obviously lower than that in the control group ( t=7.50, 4.29, P<0.05). The expressions of Nrf2 and HO-1 were increased after irradiation, which could be further increased after CTR1 silencing. In addition, cuproptosis associated protein DLAT, LIAS and FDX1 were reduced post-irradiation, which were recovered after CTR1 silencing. Conclusions:The radioresistance of HIEC and IEC-6 cells was enhanced after CTR1 silencing, possibly through the intracellular ROS and cuproptosis pathway.

Effect of circular RNA hsa_circZDHHC21_004 on the proliferation of the human small intestinal epithelial cells HIEC-6 exposed to 60Co γ-rays / 中华放射医学与防护杂志

Objective:To study the influence of circular RNA hsa_circZDHHC21_004 on the proliferation of human small intestinal epithelial cells HIEC-6 after 60Co γ-rays exposure. Methods:HIEC-6 cells were exposed to 60Co γ-rays at 0, 5, 10, and 15 Gy with a dose rate of 1 Gy/min. The expression level of hsa_circZDHHC21_004 in the irradiated HIEC-6 cell was detected. Hsa_circZDHHC21_004 was knocked-down to investigate the influences of hsa_circZDHHC21_004 on the proliferation of irradiated HIEC-6 cells by CCK-8 assay and colony formation assay. Results:The expression level of hsa_circZDHHC21_004 in HIEC-6 cells was upregulated by (1.00±0.24), (1.34±0.28), (1.85±0.31), and (2.80±0.64) times of control after 0, 5, 10, and 15 Gy irradiation, respectively and there were significant difference between 10 or 15 Gy group and 0 Gy group ( F=10.86, P=0.008). Knockdown of hsa_circZDHHC21_004 significantly increased the proliferation rate of HIEC-6 cells at 24, 48, and 72 h after 10 Gy irradiation compared with non-irradiated control ( t=-6.25, -5.83, -7.75, P < 0.001). Under 2 and 5 Gy irradiation, the clone formation rates of the hsa_circZDHHC21_004 knockdown cells were significantly higher than those of the control ( t=-7.45, -8.83, P<0.01). Conclusions:Hsa_circZDHHC21_004 is increased after irradiation and influenced the proliferation of irradiated HIEC-6 cells.

Research progress of the roles of metabolic reprogramming in radiation-induced direct- and bystander-effects / 中华放射医学与防护杂志

Metabolic reprogramming refers to the phenomenon that tumor cells, in order to meet their own growth and energy needs, regulate their biological functions by changing their metabolic mode, help themselves resist external stresses, and thus enable cells to adapt to hypoxia, acid, nutrient deficiency and other microenvironments and rapidly proliferate. It was found that metabolic reprogramming could contribute to radiation resistance and it also could be induced in bystander cells which may result in radiation resistance and the cancellation. Investigation the mechanism of radiation-induced metabolic reprogramming may provide new ideas and a theoretical framework for radiation protection, radiotherapy, and radio-diagnosis. This article reviewed the research progress on the mechanism of metabolic reprogramming in the direct and bystander effects of radiation.

Research progress on the role and mechanism of premature cellular senescence on wound healing in radiation-induced skin injury / 中华放射医学与防护杂志

Radiation skin injury can be induced by medical exposure, occupational exposure, and emergency exposure. Many relevant studies focused on the prevention and treatment of radiation-induced skin injury, but the underlying molecular mechanisms have not been fully clarified. It has been demonstrated that radiation-induced premature cellular senescence is involved in radiation skin injury. To discuss the relationship between radiation-induced premature cellular senescence and radiation-induced skin injury, this paper reviewed the mechanism of radiation-induced skin injury, the promotion of premature cellular senescence and related signal pathways, and the role of premature cellular senescence in wound healing.

Research progress of radiation protection in interventional diagnosis and treatment of pediatric heart disease / 中国基层医药

Interventional diagnosis and treatment of heart disease is the gold standard to evaluate the anatomy and physiology of children with congenital heart disease. It plays an important role in the treatment of congenital heart disease. However, ionizing radiation is inevitably harmful to the health of children and surgery operators to varying degrees. More and more attention has been paid by surgery operators to children's unique characteristics, protective awareness and skills. This paper reviews recent literature regarding the application, radiation hazards, and research status of interventional surgery in children with congenital heart disease, which hope to help people to better understand the importance of ionizing radiation protection.

Analysis of high risk factors for chromosomal aberrations in peripheral blood lymphocytes of 200 radiation workers in Hainan Province / 上海预防医学

ObjectiveTo investigate the current status and high-risk factors of chromosomal aberrations in peripheral blood lymphocytes （PBL） of radiation workers in Hainan Province. MethodsA total of 200 radiological workers who underwent occupational health examination in Hainan Provincial Hospital of Traditional Chinese Medicine from January 2021 to December 2021 were selected to collect the occupational health examination data and the rate of PBL chromosomal aberrations. The influencing factors of PBL chromosomal aberrations were analyzed by logistic regression model. The predictive value of logistic regression prediction model on PBL chromosomal aberrations were determined by using the reciver operator characteristic （ROC） curve. ResultsA total of 20 000 cells （100 cells/person） were tested. The chromosomal aberration rate was 0.37% （74/20 000） and the PBL chromosomal aberration rate in the subjects was 6.00% （12/200）. Univariate analysis showed that PBL chromosomal aberrations in radiological workers were related to age， length of service， type of work and education （all P<0.05）， but not to gender （P>0.05）. The logistic regression prediction model was constructed based on the influencing factors， with χ2=9.413， df=9， P=0.852， suggesting a good model fit. The logistic regression prediction model predicted the area under the curve （AUC） for the occurrence of PBL chromosomal aberrations in radiation workers was 0.914 （95%CI： 0.866‒0.949）， with a cut-off value of 3.05， corresponding to a prediction sensitivity and specificity of 100.00% and 75.98%， respectively. ConclusionThe incidence of PBL chromosomal aberrations in radiological workers in Hainan Province was 6.00%， with age， working age and job type as high-risk factors and education level as a protective factor. The prediction model constructed by the above factors can provide a reliable basis for clinical prediction of PBL chromosomal aberrations in radiological workers.