Radiation Medicine and Protection最新文献

Objective

To investigate the effect and mechanism of Nup50 on radiation-induced DNA damage repair to radiation and explore the potential role of Nup50 as radioprotective target.

Methods

The Nup50 gene was knocked down in HUVEC cells using lentiviruses. Colony formation, CCK-8, and flow cytometry were performed to determine the viability, proliferation and apoptosis of HUVEC cells treated with γ-rays，respectively. The extent of DNA damage was evaluated by using comet assay and immunofluorescence staining against γ-H2AX. In addition, we explored the role of Nup50 in DNA damage response (DDR) pathways through western blotting assay. Finally, nuclear and chromatin fractionation were performed to determine the potential molecular mechanism underlying the radiation protection function of Nup50 knockdown.

Results

Nup50 knockdown increased the cellular resistance to ionizing radiation. The CCK-8 data showed that cell viability was significantly increased in the Nup50 knockdown group after radiation (t ​= ​4.23, P ​< ​0.01). The Nup50 knockdown group also showed more survived colonies (t ​= ​10.06, P ​< ​0.001), less apoptosis rate (t ​= ​3.78, P ​< ​0.05) and less unrepaired DNA damage. Furthermore, Nup50 knockdown increased radiation-activated phosphorylation levels of DNA-PKcs in HUVEC cells. Finally, the nuclear and chromatin fractionation data showed that inhibiting Nup50 increased the recruitment of DNA-PKcs to chromatin after DNA damage.

Conclusions

Our findings revealed that Nup50 knockdown promoted radioresistance in normal HUVEC cells by regulating DNA-PKcs pathway, suggesting Nup50 as a potential target for radiation protection.

Skin Exposure of skin to ionizing radiation can induce acute or chronic biological effects, resulting in radiation-induced skin injury (RSI). Premature cellular senescence, caused by oxidative stress and/or DNA damage from chemical or physical agents, leads to the decrease of cellular proliferation and physiological function. Persistent DNA damage and accumulation of senescent cells are associated with the progression of radiation-induced injury. Atopic dermatitis and RSI have similar inflammatory symptoms. The treatment of tacrolimus (TAC) in atopic dermatitis may be associated with premature cellular senescence. TAC can prevent the onset of cellular senescence by inactivating the p38 mitogen-activated protein kinase (p38 ​MAPK). The activation of p38 ​MAPK can induce the senescence-associated secretory phenotype (SASP) by enhancing the transcriptional activity of nuclear factor kappa-B (NF-κB), which ultimately leads to premature cellular senescence. FK506 binding protein 51 (FKBP51) exhibits resistance to ionizing radiation, but the mechanism of TAC regulation of ionizing radiation-induced premature senescence still needs further study. This review discusses the mechanism of cellular senescence in RSI and the role of TAC in both dermatitis and RSI.

Objective

To evaluate the health-care level (HCL), one of the most extensively used indicators to assess the level of medical exposure, and its influencing factors in China.

Methods

Based on the data from the China Statistical Yearbook of the National Bureau of Statistics and other public documents, HCL was calculated in terms of the number of physicians per head of population throughout the country. Multiple linear regression was used to analyze the association of HCL with main socioeconomic factors, including population size, area, number of administrative divisions and gross domestic product (GDP).

Results

Since 2015, there has been at least one physician for every 1,000 people in China on average. However, by 2019, there has yet been one physician for more than 1,000 people in each of two provinces. By 2020, there was at least one physician for every 1,000 people across all 31 provincial-level administrative districts (provinces). The population size and GDP were the influencing factors on HCL, with correlation coefficients of 0.416 and −0.583, respectively. Furthermore, a moderate correlation was found between HCL and the frequency of medical exposure (FME) to ionizing radiation (r ​= ​−0.620, P ​= ​0.028).

Conclusion

There has been at least one physician for every 1,000 people since 2015, but there are great differences between various provinces. HCL as an indicator to evaluate level of medical exposure is warranted further research in China.

This paper presents a comprehensive overview of the historical trajectory and development in biophoton studies over the past 100 years, with a particular focus on the recent progress regarding the pivotal role of biophoton in mediating radiation-induced bystander effects (RIBE). The exploration of biophoton mystery starts from the initial observation of mitogenetic radiation and continues to develop to the contemporary science of biophotonics. The properties and underlying mechanisms of biophoton emission are described with illustrative examples from diverse biological systems such as plants, animals and humans. The conclusive evidence of cell-to-cell communication facilitated by biophoton signaling is presented, followed by an elaborate interpretation of potential mechanisms through which biophoton mediates RIBE. The engagement of mitochondria and exosomes in this process is extensively clarified, by highlighting their significant roles in biophoton-mediated RIBE. The advances in biophoton research in respect of bystander response to ionizing radiation may offer profound insights into radiobiology and provide for possible future applications as well in radiation medicine and protection.

Bioinformatics has become increasingly integral to radiation biology, also known as radiobiology, providing substantial support through data storage, conversion, visualization, and sharing. This review aims to deepen understanding of bioinformatics application in radiobiology by introducing key databases and analytical tools in radiobiology, including general bioinformatics databases, radiobiology-specific databases, data processing tools, and statistical analysis tools for differentially expressed genes (DEGs) and LC/MS analysis. This review also discusses bioinformatics applications in radiobiological fields, such as radioresistance and immune cell enrichment. Despite these advances, challenges such as data interoperability remain. Methods and projects to address these issues, such as GeCo and GMQL, are also examined.

Objective

To assess if there is a relationship between residential radon exposure and two lung cancer histological types, small-cell carcinoma (diagnosed in people with a smoking history) and adenocarcinoma (the most commonly diagnosed histologic type in people who have never smoked) among males and females in Canada.

Methods

With survey data of long-term radon measurements in residential homes, long-term averaged tobacco consumption rates in the units of cigarettes per day per person and long-term averaged age-standardized lung cancer incidence rates at provincial level, simple linear fitting (ANOVA linear regression) was applied in this study to determine the effect on lung cancer induction by smoking and exposure to indoor radon, and to assess if there is a relationship between residential radon exposure and lung cancer histological types.

Results

Lung cancer incidence rates correlate very well with the tobacco consumption rates (P ​< ​0.05). However, females appear to be more likely than males to develop lung cancer at a given amount of cigarette consumption. For both small-cell carcinoma and adenocarcinoma, a statistically significant correlation between incidence rate and mean radon concentration was observed for females, the correlation was much stronger for adenocarcinoma (P ​= ​0.0057) than small-cell carcinoma (P ​= ​0.0483). However, there was no such correlation for males.

Conclusion

It is possible that female non-smokers are more susceptible to radon-induced lung cancer, and the joint effect of radon exposure and tobacco smoking may be worse in female smokers compared to males, such that higher incidence rate of adenocarcinoma among females compared to males were observed in recent decades, even though females never smoked more than males.

Cellular senescence has emerged as an important contributor to aging and age-related diseases. Non-ionizing radiation (NIR), including ultraviolet radiation and electromagnetic fields, has been increasingly recognized as a key inducer of premature senescence. In this review, we discuss the molecular mechanisms of NIR-induced cellular senescence and its effects on aging and age-related diseases. We also summarize the modulation strategies for NIR-induced cellular senescence. A better understanding of the complex relationship between non-ionizing radiation, cellular senescence and age-related pathology may lead to interventions to ameliorate radiation damage and delay aging. Further research is still needed to elucidate the precise mechanisms, dose-response effects, and to develop protective strategies against radiation-induced senescence.

Objective

To analyze the current status of knowledge and practices among the Moroccan dentists in the region of Rabat-Salé-Kenitra, towards radiation protection.

Methods

This is a cross-sectional study based on a questionnaire related to knowledge and practice regarding radiation protection of patients and dental staff from April to June 2022. The study sample included 325 dentists practicing in the Rabat-Salé-Kénitra region. The target population consisted of all dentists working in public, semi-public and private workplaces.

Results

96.6% of dentists were aware of radiation protection. However, nearly 35% were aware of ALARA (as low as reasonably achievable) principle and 73.9% thought that dental X-rays are harmful. 63.6%of subjects used digital image receptor. Only 16.7% of them used a film holder and more than 60% didn't follow the position and distance rule. The median knowledge score was 7 [5, 9], and there was a statistically significant difference according to dentist qualification (P ​= ​0.007), dental radiation protection continuous training (P ​< ​0.0001), age (P = ​0.007) and years of experience (P ​= ​0.039). The median practice score was 5 [4, 6] and there was a statically significance association according to workplace setting (P ​= ​0.001). There was a significant positive relationship between knowledge score and practice score (r ​= ​0.24, P<0.0001). Dentist qualification (OR 0.51, 95%CI: 0.27–0.94, P ​= ​0.03) and continuous training (OR 2.40, 95%CI: 1.47–3.93, P<0.0001) were significant predictors of knowledge, while workplace setting (OR 0.54, 95%CI: 0.32–0.93, P ​= ​0.027) and knowledge score (OR 1.24, 95%CI: 1.12–1.38, P<0.0001) were predictors of practices.

Conclusion

Improving dentists' knowledge of radiation protection measures and tools as well as dose reduction techniques could increase their safe practices in dental radiology.

Objective

To assess the performance and advantages of HyperArc for radiotherapy of multiple brain metastases with dosimetric parameters with respect to coplanar volumetric modulated arc radiotherapy (c-VMAT), and characterize implicit correlations between tumor features and dosimetric parameters.

Methods

This retrospective study involved 40 patients with multiple brain metastases (4–16 tumors, 12.8–240.8 cm³) who received simultaneous radiotherapy at the Department of Radiation Oncology, Shenzhen People's Hospital from January 2019 to December 2022. Both HyperArc and c-VMAT plans were designed by the same and qualified physicist using the Eclipse system with Truebeam. A single isocenter and a 6 ​MV flattening filter-free (6FFF) photon beam were used for radiotherapy of multiple brain metastases in each plan. Dosimetric parameters of tumors and organs at risk (OARs) were compared between HyperArc and c-VMAT plans. Correlations between tumor features (number and volume) and dosimetric parameters were revealed and analyzed. Furthermore, monitor units (MUs) of both plan types were recorded to assess rays utilization and delivery efficiency.

Results

Compared to c-VMAT plans, HyperArc plans achieved higher maximum dose (D_max) (5.23%, t ​= ​7.87, P ​< ​0.01), but lower minimum dose (D_min) (3.94%, t ​= ​−2.12, P ​= ​0.04) and mean dose (D_mean) (1.05%, t ​= ​−3.29, P < ​0.01) for planning gross tumor volumes (PGTVs). The conformity index (CI), homogeneity index (HI), gradient index (GI) and R_50% of PGTVs with HyperArc were better than those with c-VMAT, with the improvements of 20.78%, 1.68%, 19.83% and 36.20%, respectively (P ​< ​0.01). The dosimetric parameters of OARs were significantly improved in HyperArc plans compared to c-VMAT plans. Specifically, the D_max and the D_mean to the brainstem decreased by 16.14% and 11.37%, respectively. The D_max for eye_L decreased by 16.88%, for eye_R decreased by 11.67%, for optical nerve_L decreased by 12.56 ​%, and for chiasm decreased by 18.12%. Few correlations were observed between the differences of CI/HI/GI/R_50% and the number of PGTVs between the two plan types. Whereas, regression analysis indicated that the differences of CI/ GI/ R_50% were negatively correlated with the volume of PGTVs, respectively. Moreover, although HyperArc plans reduced the MUs by 4.74 ​% compared to c-VMAT, no significant difference was observed (P ​> ​0.05).

Conclusions

This study demonstrates the promising performance of HyperArc for radiotherapy of multiple brain metastases, including better dose conformity for the tumors, more rapid dose drop and less dose spillage