Modalidades de radioterapia empregadas para o câncer de cabeça e pescoço / Radiotherapy modalities used for head and neck cancer

O câncer de cabeça e pescoço (CCP) refere-se ao grupo de tumores que atingem a laringe, cavidade nasal, nasofaringe, orofaringe, cavidade oral e glândulas salivares. A radioterapia no paciente com CCP representa uma terapia para manutenção do órgão, através da destruição das células neoplásicas malignas. O objetivo do presente estudo foi identificar estratégias radioterápicas aplicadas ao paciente com CCP e seus respectivos efeitos colaterais em cavidade oral, além de investigar as principais modalidades utilizadas nos sistemas de saúde do Brasil. Tratou-se de uma revisão narrativa da literatura com busca ativa das bases eletrônicas PUBMED, LILACS e SCIELO. Após todas as etapas de refinamento, um total de 58 artigos foram incluídos na presente revisão. A radioterapia possui papel de destaque no tratamento do CCP. No entanto, por não ser um método terapêutico com alta especificidade, resulta em efeitos adversos ao tratamento como mucosite oral, trismo e disfunção salivar, que findam por reduzir a qualidade de vida do paciente. Dentre as principais técnicas radioterapêuticas utilizadas no Brasil, a IMRT e VMAT caracterizam-se como as formas mais avançadas da terapia em 3D, proporcionando doses equivalentes para cada área da lesão tumoral, poupando áreas teciduais circunvizinhas que não necessitam de irradiação. Além da toxicidade reduzida, uma maior sobrevida pode ser observada em pacientes tratados com essas técnicas. Um dos maiores desafios atuais na radioterapia contra o CCP é a proteção de tecidos saudáveis. Nesse sentido, a IMRT e VMAT apresentam superioridade em relação às demais técnicas.

Head and neck cancer (CCP) refers to the group of tumors that affect the larynx, nasal cavity, nasopharynx, oropharynx, oral cavity and salivary glands. Radiotherapy in patients with CCP represents a therapy for organ maintenance, through the destruction of malignant neoplastic cells. The aim of this study was to identify radiotherapy strategies applied to patients with CCP and their respective side effects in the oral cavity, and to investigate the main modalities used in health systems in Brazil. It was a narrative review of the literature with active search of electronic databases PUBMED, LILACS and SCIELO. After all stages of refinement, a total of 58 articles were included in this review. Radiotherapy has a prominent role in the treatment of CCP. However, because it is not a therapeutic method with high specificity, it results in adverse effects to treatment such as oral mucositis, trismus and salivary dysfunction, which end up reducing the quality of life of the patient. Among the main radiotherapeutic techniques used in Brazil, IMRT and VMAT are characterized as the most advanced forms of 3D therapy, providing equivalent doses for each area of the tumor sparing surrounding tissue areas that do not require irradiation. In addition to reduced toxicity, greater survival can be observed in patients treated with these techniques. One of the biggest current challenges in radiation therapy against CCP is the protection of healthy tissues. In this sense, the IMRT and VMAT present superiority in relation to the other techniques.

Differential mRNA expression in fractional low-dose radiation-induced senescence of HBE cells / 中国辐射卫生

Objective To explore the differentially expressed mRNAs and related biological processes and pathways in fractional low-dose ionizing radiation (LDIR)-induced senescence of normal human bronchial epithelial (HBE) cells by high-throughput mRNA sequencing and bioinformatics techniques. Methods Senescence-associated β-galactosidase staining and senescence-associated secretion phenotype gene mRNA and protein expression levels were measured at 24 and 48 h after irradiating HBE cells 7 times at doses of 0, 50, 100, and 200 mGy, respectively. The differentially expressed genes were screened by high-throughput sequencing for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results The senescence-positive area of fractional low-dose irradiated HBE cells increased in a dose-dependent manner (P < 0.05). The mRNA levels and protein expression of transforming growth factor-β1(TGF-β1) and matrix metalloproteinase-9(MMP-9) genes were increased in the 100 mGy × 7 and 200 mGy × 7 groups at 24 and 48 h after the end of irradiation compared with the control group. High-throughput sequencing showed that there were 882, 475, and 1205 differentially expressed mRNAs in each dose group compared with the control group. GO analysis showed that the differentially expressed mRNAs in each dose group were mainly enriched in biological processes such as cell cycle regulation, regulation of nitrogen compound metabolic process, regulation of cell division and response to stimulus. KEGG analysis showed that the differentially expressed mRNAs were mainly enriched in the pathways of cell cycle, cell senescence, and ferroptosis. Conclusion Fractional LDIR induced senescence in HBE cells, and differentially expressed mRNA-associated biological processes and pathways in senescent cells are related to cell cycle and cell senescence.

Analysis of micronucleus rate in 394 radiation workers with cytokinesis-block micronucleus method / 中国辐射卫生

Objective To analyze the micronucleus rate of radiation workers and to provide accurate occupational health monitoring basis in radiation workers exposed to low-level ionizing radiation for a long time. Methods The radiation group consisted of 353 radiation workers who had been exposed to ionizing radiation during work, while the control group consisted of 41 radiation workers who had not yet been exposed to ionizing radiation before work. The cytokinesis-block micronucleus method was used to determine the micronucleus rate. Results The average micronucleus rate in the radiation group was significantly higher than that in the control group (t = −2.95, P < 0.05). In the radiation group, the micronucleus rate gradually increased with age, and the difference was statistically significant (F = 8.36, P < 0.05). The micronucleus rates of workers with > 10 and > 30 years of service were significantly higher than those of workers with < 10 years of service (χ2 = −44.79, −60.47, P < 0.05). The micronucleus rate in females was significantly higher than that in males (t = 3.93, P < 0.05). The micronucleus rates in the diagnostic radiology group and the industrial detection group were significantly higher than that in the control group (t = 3.51, 3.65, P < 0.05). Conclusion The micronucleus rate has increased among the radiation workers exposed to low-level ionizing radiation for a long time. It is necessary to further strengthen occupational health monitoring and radiation protection education for radiation workers, especially the medical workers that constitute the largest population of radiation exposure workers.

Analysis of occupational health examination data of 215 radiation workers from hospitals in Jiayuguan, China / 中国辐射卫生

Objective To understand the effects of long-term exposure to ionizing radiation on the health of radiation workers. Methods A total of 215 radiation workers were randomly selected and assigned to the exposure group and 197 non-radiation workers were assigned to the control group. The occupational health examination results of the two groups were compared and analyzed. Results The WBC count of the exposure group was lower than that of the control group (P＜0.05), while the abnormality rates of ocular lens, ECG, liver function, and thyroid function were significantly higher in the exposure group than in the control group (P＜0.05). In the exposure group, the abnormality rate of liver function was lower in females than in males, and the abnormality rate of hemoglobin level was higher in females than in males (P＜0.01). The abnormality rate of ocular lens increased with age (P＜0.01). The abnormality rate of hemoglobin level was different among different age groups (P＜0.01). The abnormality rate of ocular lens increased with increasing years of service. The abnormality rates of RBC count and hemoglobin level in the general radiotherapy group were higher than those in the interventional radiotherapy group (P＜0.01). Sex was the influencing factor for abnormal liver function (P＜0.01). Conclusion Prolonged exposure to low doses of ionizing radiation can adversely affect the health of radiation workers in medical institutions.

Progress of research on health effects and healthy risk assessment of ionizing radiation / 中国辐射卫生

Occupational exposure to ionizing radiation represents a critical factor contributing to health risks in workplaces. Previous experimental and clinical studies have demonstrated that ionizing radiation affects human health. Therefore, scientific assessment of health risk caused by ionizing radiation and effective protection against ionizing radiation are of great importance to formulate the preventive interventions against occupational exposure to ionizing radiation. This review summarizes the advances in the research on health effects, health risk assessment methods, and protective interventions of ionizing radiation. We call for research on the health effects of low-dose radiation, individual difference, and optimization of preventive strategies. In addition, improved mechanisms of health monitoring, periodical healthy examinations, and monitoring of radiation doses should be implemented. Moreover, strict compliance to operating procedures and occupational preventive interventions are recommended. These measures aim to minimize the potential harmlessness of occupational exposure to ionizing radiation, thereby safeguarding the health and safety of individuals exposed to ionizing radiation.

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.

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.

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.

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.

Advances in research and application of ionizing radiation biomarkers / 中国药理学与毒理学杂志

Exposure to ionizing radiation intervenes in genomic stability and gene expression,resulting in the disruption of normal metabolic processes in cells and organs by causing complex biolog-ical responses.Altered genomic variations,gene expression and metabolite concentrations in blood or tissue samples reflect systemic radiation damage.With the application of new techniques and exten-sive study on the mechanisms for ionizing radiation damage,related indicators such as chromosomal variation,gene expression,lipid and metabolism are being recognized and promise to be the markers for early diagnosis and prognosis of radiation exposure.Therefore,this article reviews recent progress in and potential applications of biomarkers related to ionizing radiation injury.

Study on OS-induced DNA damage from X-ray activation and cellular premature aging of HaCaT cells / 中国医学装备

Objective:To explore the changes of oxidative stress(OS),DNA damage and the occurrence of cellular premature aging of human immortalized keratinocytes(HaCaT)after that was radiated by X-ray with different doses.Methods:HaCaT cells were radiated by X-ray,and they were divided into 0 Gy group,5 Gy group and 10 Gy group according to the irradiation dose.The levels of intracellular reactive oxygen species(ROS)were detected by 2,7-Dichlorofluorescein diacetate(DCFH-DA)fluorescent probe,and the intracellular content of malondialdehyde(MDA)of lipid peroxidation products and the activity of superoxide dismutase(SOD)were measured by colorimetry.Immunofluorescence staining was used to detect the phosphorylated histone 2A variant(γ-H2AX)in HaCaT cells that were radiated by X-ray with different doses.Cell count kit-8(CCK-8)was used to detect the effect of X-ray with different doses on the proliferation of HaCaT cells after X-ray with different doses radiated them.β-Galactosidase staining was used to detect the proportion of premature aging cells.The changes of p21 and p53 protein expressions after X-ray irradiation were detected by Western blot.Results:After HaCaT cells were radiated by X-ray for 24h,the fluorescence intensity of 2',7'-Dichlorofluorescein(DCF)in 5 Gy and 10 Gy groups were significantly higher than that in the 0 Gy group,and the MDA contents of them were significantly higher than that in the control group,and the SOD activities of them were significantly lower than that in the control group(F=38.35,92.22,5.22,P<0.05),respectively.The change of γ-H2AX focus showed a dose-dependent significant increase at 1 h after irradiation,and the difference between them and control group was statistically significant(F=129.3,P<0.05).At 6h,24h and 48h after X-ray radiated HaCaT cells,the cell proliferation abilities of 5 Gy group and 10 Gy group were significantly decreased than that of 0 Gy group(F=116.41,62.20,34.29,P<0.01),and the β-Galactosidase activity of the two groups were significantly increased than that of 0 Gy group,and the difference was significant(F=1629.22,P<0.01).At 72h after X-ray with different doses radiated HaCaT cells,the expression levels of p21 and p53 proteins of 5 Gy group and 10 Gy group increased,and the differences of them among three groups were significant(F=104.4,66.69,P<0.01),respectively.Conclusion:Ionizing radiation can induce the occurrences of oxidative stress and DNA damage in HaCaT cells,and cause the occurrence of cellular premature aging.

Mechanisms on radiation resistance induced by an estrogen receptor in breast cancer cells / 中华放射医学与防护杂志

Objective:To explore the effects of estrogen receptor α (ERα) encoded by protein encoding gene ESR1 on the radiation resistance of breast cancer cells and their molecular mechanisms.Methods:The ESR1 overexpression plasmid was transfected into estrogen receptor (ER)-negative breast cancer cells. Then, the shRNA-ESR1 vector was introduced into ER-positive cell to establish models with different phenotype. The ATG5 mRNA level and protein expression levels of LC3B-I, LC3B-II, P62, FIP200, ATG5, ATG7, ATG12, Beclin1, ULK1 were detected using qPCR and Western blot techniques. Cell death was measured using flow cytometry. The radiation sensitivity was determined through the colony formation assay. The mortality of breast cancer cells under the autophagy gene knockdown and overexpression or treated with estrogen receptor inhibitor (TAM) combined with ionizing radiation were detected by trypan blue staining.Results:Under the condition of 8 Gy X-ray irradiation, the knockdown of ESR1 in ER-positive ZR75 breast cancer cells promoted cell death ( t = 3.49, 3.13, P < 0.05), while the overexpression of ESR1 in ER-negative MDA-MB-231 breast cancer cells inhibited cell death ( t = 4.16, 7.48, P < 0.05). Compared to the control group, the treatment with chloroquine increased the number of formed colonies of ESR1 knockdown ZR75 cells ( t = 8.49, P < 0.05), and inhibiting autophagy could reduce the death of ZR75 cells caused by ESR1 silencing. Under the treatment with ionizing radiation, the overexpression of ESR1 in MDA-MB-231 cells promoted protective autophagy, which, however, was reduced after ESR1 knockdown in ZR75 cells. Furthermore, it was observed that the knockdown of ATG5 in ZR75 cells was associated with reduced autophagy and an increase in cell death ( t = 4.19, 6.39, P < 0.05). In contrast, the overexpression of ATG5 in ZR75 cells reversed the increase in cell death caused by ESR1 knockdown ( t = 1.70, 4.65, P < 0.05). After the treatment of ER-positive ZR75 breast cancer cells with TAM, the expressions of ATG5 and ATG12 decreased, suggesting inhibited autophagy and an increase in cell death ( t = 18.70, P < 0.05). Furthermore, these processes were promoted by ionizing radiation ( t = 16.82, P < 0.05). Conclusions:The estrogen receptor encoded by ESR1 promotes protective autophagy of ER-positive breast cancer cells by increasing ATG5, further leading to radiation resistance in ER-positive breast cancer cells. Treatment with tamoxifen combined with ionizing radiation can increase the radiation sensitivity of ER-positive breast cancer cells.

Effects of sleep disorders on hematopoietic stem cells in bone marrow of irradiated mice / 中华放射医学与防护杂志

Objective:To investigate the effects of sleep disorders (SD) on the radiation injury of hematopoietic stem cells (HSCs) in bone marrow (BM).Methods:Totolly 56 C57BL/6J male mice aged 6-8 weeks were enrolled in this study. They were subjected to whole body irradiation of 60Co γ-rays with doses of 5.0 and 7.5 Gy. A SD model was established using a SD device. According to the random number table method, the mice were divided into seven groups: the control group (Con group), the SD group, the mere radiation group (IR group), the group of post-irradiation SD (IR+ SD group), the group of post-irradiation SD treated with phosphate buffer solution (IR+ SD+ PBS group), the group of post-irradiation SD treated with GSK2795039 (IR+ SD+ GSK group), and the group of post-irradiation SD treated with N-acetylcysteine (IR+ SD+ NAC group), with in eight mice each group. The changes in the peripheral blood of the mice after 5.0 Gy irradiation were detected using the collected tail venous blood, and the survival rates of the mice after 7.5 Gy irradiation were observed. The changes in the density and count of bone marrow cells were observed using hematoxylin and eosin (HE) staining. The number of hematopoietic stem cells in bone marrow (LSK cells), as well as their apoptosis level and changes in cell cycle, were detected using flow cytometry. Furthermore, indicators of LSK, such as reactive oxygen species(ROS) and mitochondrial-derived reactive oxygen species (mtROS), were analyzed. Nicotinamide adenine dinucleotide phosphate (NADP+ /NADPH) and glutathione (GSSG/GSH) were detected using an enzyme microplate reader in order to observe the oxidative stress level of LSK. Furthermore, flow cytometry was employed to sort the LSK cells from the mice, and flow cytometry was used to detect the expression of NADPH oxidase 2(NOX2) and cysteinyl aspartate specific proteinnase-1(Caspase-1), and polymerase chain reaction (PCR) was used to detect the expression of inflammatory factors such as NOX1-4, interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 18 (IL-18), and tumor necrosis factor α (TNF-α). Results:Compared to the IR group, the IR+ SD group exhibited significantly slower recovery of white blood cells (WBC) and platelets (PLT) ( t = 4.39, 6.37, P < 0.05), the bone marrow cell count decreasing from (2.14 ± 0.38) × 10 7 to (3.59 ± 0.29) × 10 7 ( t = 8.55, P < 0.05), significantly decreased proportion of G 0-phase LSK cells, significantly increased proportion of apoptotic cells ( t = 7.53, 8.21, P < 0.05), and significantly increased DCFH-DA, MitoSOX, and NADP+ /NADPH ( t = 22.99, 29.47, 3.77, P<0.05). In the case of IR, SD further promoted the activation of NOX2 and led to increases in the mRNA expression of downstream inflammatory factors such as IL-1β, IL-6, IL-18, and TNF-α ( t = 6.95, 6.01, 8.39, 4.91, 5.56, P < 0.05). Inhibition of NOX2-ROS could prevent the SD-induced aggravation of post-irradiation hematopoietic injury. This significantly reduced the apoptotic rate of LSK cells and the expression of inflammatory factors, ultimately accelerating the hematopoietic recovery of LSK cells ( t = 9.24, 3.92, P < 0.05). Conclusions:SD can aggravate the IR-induced injury of hematopoietic stem cells in bone marrow, primarily by activating the NOX2-ROS-Caspase-1 axis. This will increase the levels of intracellular inflammatory factors and ROS, promote cell apoptosis, and ultimately inhibit the hematopoietic recovery of bone marrow.

Role of senescence-associated secretory phenotype-related premature senescence in ionizing radiation-induced damage to vascular endothelial cells / 中华放射医学与防护杂志

Radiation-induced damage to vascular endothelium is a major complication of radiotherapy and a primary cause of morbidity and mortality in the population exposed to radiation. Ionizing radiation-induced cellular senescence serves as a critical factor in damage to vascular endothelial cells. Therefore, understanding the mechanisms of cellular senescence caused by senescence-associated secretory phenotype (SASP), as well as its role in ionizing radiation-induced damage to vascular endothelial cells, is significant for preventing and treating ionizing radiation-induced damage to vascular endothelial cells. In this study, the relationship between SASP-related premature senescence and this ionizing radiation-induced damage was explored from the following aspects: the mechanisms behind ionizing radiation-induced damage to vascular endothelial cells, ionizing radiation-induced cellular senescence, and the role of SASP-related premature senescence in the ionizing radiation-induced damage to vascular endothelial cells, as well as potential targets.

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.

El conocimiento y cumplimiento de las normas de protección sobre la radiación ionizante en una clínica dental docente / Knowledge and compliance with ionizing radiation protection standards in a teaching dental clinic

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.

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.

Research progress of irradiation injuries anti-agents / 中华劳动卫生职业病杂志

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

Research progress on the effects of ionizing radiation exposure on cardiovascular systems / 中国辐射卫生

With the rapid development and widespread application of medical imaging technologies, ionizing radiation has become unavoidable in human lives. Accurate assessment of healthy effects of ionizing radiation is of great significance to reduce the risk of exposure to radiation. Increasing evidence has proven the impact of ionizing radiation on cardiovascular systems. This article reviews the effects of ionizing radiation on heart, blood pressure, and blood vessels and the possible mechanisms, so as to provide insights into implementation of targeted protective interventions and reduction of ionizing radiation hazard.

Research progress on effects of radiation exposure during pregnancy on offspring health / 中国辐射卫生

With social development and technology progress, there is an increasing use of daily electronic products and radioactive medical devices, which increases the risk of exposure to radiation in medical practices, daily life activities, and work. Notably, the effects of radiation exposure on pregnant women and their offspring have attracted increasing attention. Comprehensive and accurate assessment and intervention of the effects of radiation exposure on pregnant women and their offspring are of great significance to reduce birth defects and achieve eugenics. This article reviews the effects of radiation exposure during pregnancy on offspring health based on animal experiments and clinical studies, and describes the possible mechanisms, so as to provide the basis for further studies.