Objective This paper is to explore the DNA repair mechanism of immune adaptive response （AR） induced by low dose radiation （LDR）, the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic su...Objective This paper is to explore the DNA repair mechanism of immune adaptive response （AR） induced by low dose radiation （LDR）, the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic subunit （DNA-PKcs） and PARP-1 genes in the LDR-induced AR in EL-4 cells. Methods The apoptosis and cell cycle progression of EL-4 cells were detected by flow cytometry in 12 h after the cells received the pre-exposure of 0.075 Gy X-rays （inductive dose, D 1） and the succeeding high dose irradiation （challenge dose, D2; 1.0, 1.5, and 2.0 Gy X-rays, respectively） with or without wortmannin （inhibitor of ATM and DNA-PK） and 3-aminobenzamid （inhibitor of PARP-1）. And the protein expressions and mRNA levels related to these genes were detected with flow cytometry and reverse transcription-polymerase chain reaction in 12 h after irradiation with D2. Results The mRNA and protein expressions of p53 and PARP-1 in EL-4 cells in the D1 ＋ D2 groups were much lower than those in the D2 groups, and those of PARP-1 in the 3-AB ＋ D2 and the 3-AB ＋ D1 ＋ D2 groups were much lower than those in the D2 and the D1 ＋ D2 groups. The percentage of apoptotic EL-4 cells in the 3-AB ＋ D1 ＋ D2 groups was much higher than that in the D1 ＋ D2 groups, that in the G0/G1 and the G2 ＋ M phases was much higher, and that in the S phase were much lower. Although the ATM and DNA-PKcs mRNA and protein expressions in wortmannin ＋ D1 ＋ D2 groups were much lower than those in the D1 ＋ D2 groups, there were no significant changes in the apoptosis and cell cycle progression between the wortmannin ＋ D1 ＋ D2 and the D1 ＋ D2 groups. Conclusion PARP-1 and p53 might play important roles in AR induced by LDR.展开更多
Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhi...Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.展开更多
Background and Objective:Radiation usually results in paranasal sinusitis in patients with nasopharyngeal carcinoma (NPC), which influences patients' quality of life.This study aimed to determine the relationships...Background and Objective:Radiation usually results in paranasal sinusitis in patients with nasopharyngeal carcinoma (NPC), which influences patients' quality of life.This study aimed to determine the relationships between dose distribution in the nasal cavity and nasal mucous injury in patients with NPC treated by intensity-modulated radiation therapy (IMRT), and to find the tolerable radiation dose for the nasal mucous.Methods:Sixty-six patients with NPC treated by IMRT between October 2006 and November 2008 were enrolled.The irradiation dose in the nasal cavity was determined by the computer with the IMRT work platform.Mucociliary transport rate (MTR) was detected by modified saccharine test before IMRT, at the end of IMRT, and at 3, 6, and 12 months after IMRT.Results:The data were available for 129 nasal cavities.The cavities receiving a mean dose below or equal to 37 Gy showed substantial preservation of nasal mucous after IMRT.The MRT decreased to (62.82±38.59)%, (56.78±37.79)%, (64.05±39.37)%, and (71.13±39.55)% of pre-IMRT value at 4 time points after IMRT, with significant differences among the data (P<0.05).In contrast, when the cavities received a mean dose higher than 37 Gy, no significant differences in MTR among the time points were observed.At 3 months after IMRT, the MTR was the lowest (38.27% of pre-RT value).Conclusions:A mean radiation dose of ≤37 Gy for the nasal cavity is an optimal dose to protect the nasal cavity function.展开更多
In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given ...In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given spatial temperature profile. Our model is distilled from sub-step components in the ADT CHEETEH-E model developed at the Institute for Defense Analyses. Our model has only two parameters: the activation temperature of nociceptors and the critical threshold on the activated volume. When the spatial temperature profile is measurable, the two parameters can be determined from test data. We connect this dose-response relation to a temperature evolution model for electromagnetic heating. The resulting composite model governs the process from the electromagnetic beam deposited on the skin to the binary outcome of subject’s reflex response. We carry out non-dimensionalization in the time evolution model. The temperature solution of the non-dimensional system is the product of the applied power density and a parameter-free function. The effects of physical parameters are contained in non-dimensional time and depth. Scaling the physical temperature distribution into a parameter-free function greatly simplifies the analytical solution, and helps to pinpoint the effects of beam spot area and applied power density. With this formulation, we study the theoretical behaviors of the system, including the time of reflex, effect of heat conduction, biological latency in observed reflex, energy consumption by the time of reflex, and the strategy of selecting test conditions in experiments for the purpose of inferring model parameters from test data.展开更多
In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β valu...In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β value of fluoropolymer, which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter β and irradiation temperature (T_i)of fluoropolymer is established as follows:β=2.2×10^(-3) T_g+4×10^(-4)(T_g-T_i)+0.206.values of some tluoropolymers calculated from the above expression are in agreement with the experimental values.展开更多
Some polymers which are difficult to crosslink, even degrade, at room temperature can crosslink at high temperatures. Obviously, the irradiation temperature is closely related to the probability of radiation crosslink...Some polymers which are difficult to crosslink, even degrade, at room temperature can crosslink at high temperatures. Obviously, the irradiation temperature is closely related to the probability of radiation crosslinking or degradation reaction as well as the behaviors展开更多
The dose-response curves obtained by premature condensed chromosome (PCC)and conventional cellular genetic methods can be represented by two linear equations. The ratiO of the slopes, Kpcc/KM,, is about 28. In compari...The dose-response curves obtained by premature condensed chromosome (PCC)and conventional cellular genetic methods can be represented by two linear equations. The ratiO of the slopes, Kpcc/KM,, is about 28. In comparison to the conventional method, the PCC method has many advantages; e,g. it is faster, simpler, more sensitive and accurate. Its significance in the study of radiation damage is also discussed.展开更多
目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调...目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调查、身体测量和实验室检测。应用非条件逐步Logistic回归和限制性立方样条模型分析BMI与血脂异常患病关联及剂量-反应关系。结果最终共纳入3173例样本,武汉市江岸区居民超重、肥胖的标化患病率分别为31.30%和8.95%。血脂异常、高总胆固醇(TC)、高甘油三酯(TG)血症、高低密度脂蛋白(LDL-C)血症和低高密度脂蛋白(HDL-C)血症的标化患病率分别为20.49%、2.60%、9.78%、3.17%和6.08%。超重(OR=1.118,95%CI:1.083~1.154)和肥胖(OR=1.181,95%CI:1.123~1.243)与血脂异常患病显著相关。男性(χ^(2)=6.67,P<0.05)、女性(χ^(2)=6.07,P<0.05)、18~<45岁(χ^(2)=13.40,P<0.05)和45~<65岁(χ^(2)=8.02,P<0.05)人群的BMI与血脂异常患病呈非线性剂量-反应关系,随BMI升高,血脂异常患病风险逐渐增加继而又趋于平缓。而65岁及以上(χ^(2)=0.18,P>0.05)人群的BMI与血脂异常患病呈线性剂量-反应关系。结论BMI的连续变化和血脂异常的患病风险呈正相关的剂量-反应关系。血脂异常的指标预警防控工作需关口前移,应注重中青年的血脂防控工作,并通过倡导减轻体质量、进行早期预防和控制等措施,降低血脂异常患病风险。展开更多
基金supported by the National Natural Science Foundation of China(30570546 and 30870747)the Natural Science Foundation of Jilin Province (20090458 and 201015183)+1 种基金the Young Teachers Innovative Foundation of Jilin University(421010043430)the Young Scholars Research Foundation Program of China-Japan Union Hospital(2009)
文摘Objective This paper is to explore the DNA repair mechanism of immune adaptive response （AR） induced by low dose radiation （LDR）, the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic subunit （DNA-PKcs） and PARP-1 genes in the LDR-induced AR in EL-4 cells. Methods The apoptosis and cell cycle progression of EL-4 cells were detected by flow cytometry in 12 h after the cells received the pre-exposure of 0.075 Gy X-rays （inductive dose, D 1） and the succeeding high dose irradiation （challenge dose, D2; 1.0, 1.5, and 2.0 Gy X-rays, respectively） with or without wortmannin （inhibitor of ATM and DNA-PK） and 3-aminobenzamid （inhibitor of PARP-1）. And the protein expressions and mRNA levels related to these genes were detected with flow cytometry and reverse transcription-polymerase chain reaction in 12 h after irradiation with D2. Results The mRNA and protein expressions of p53 and PARP-1 in EL-4 cells in the D1 ＋ D2 groups were much lower than those in the D2 groups, and those of PARP-1 in the 3-AB ＋ D2 and the 3-AB ＋ D1 ＋ D2 groups were much lower than those in the D2 and the D1 ＋ D2 groups. The percentage of apoptotic EL-4 cells in the 3-AB ＋ D1 ＋ D2 groups was much higher than that in the D1 ＋ D2 groups, that in the G0/G1 and the G2 ＋ M phases was much higher, and that in the S phase were much lower. Although the ATM and DNA-PKcs mRNA and protein expressions in wortmannin ＋ D1 ＋ D2 groups were much lower than those in the D1 ＋ D2 groups, there were no significant changes in the apoptosis and cell cycle progression between the wortmannin ＋ D1 ＋ D2 and the D1 ＋ D2 groups. Conclusion PARP-1 and p53 might play important roles in AR induced by LDR.
文摘Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.
基金Sci-Tech Project of Guangdong Province (No.2006B36006006)
文摘Background and Objective:Radiation usually results in paranasal sinusitis in patients with nasopharyngeal carcinoma (NPC), which influences patients' quality of life.This study aimed to determine the relationships between dose distribution in the nasal cavity and nasal mucous injury in patients with NPC treated by intensity-modulated radiation therapy (IMRT), and to find the tolerable radiation dose for the nasal mucous.Methods:Sixty-six patients with NPC treated by IMRT between October 2006 and November 2008 were enrolled.The irradiation dose in the nasal cavity was determined by the computer with the IMRT work platform.Mucociliary transport rate (MTR) was detected by modified saccharine test before IMRT, at the end of IMRT, and at 3, 6, and 12 months after IMRT.Results:The data were available for 129 nasal cavities.The cavities receiving a mean dose below or equal to 37 Gy showed substantial preservation of nasal mucous after IMRT.The MRT decreased to (62.82±38.59)%, (56.78±37.79)%, (64.05±39.37)%, and (71.13±39.55)% of pre-IMRT value at 4 time points after IMRT, with significant differences among the data (P<0.05).In contrast, when the cavities received a mean dose higher than 37 Gy, no significant differences in MTR among the time points were observed.At 3 months after IMRT, the MTR was the lowest (38.27% of pre-RT value).Conclusions:A mean radiation dose of ≤37 Gy for the nasal cavity is an optimal dose to protect the nasal cavity function.
文摘In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given spatial temperature profile. Our model is distilled from sub-step components in the ADT CHEETEH-E model developed at the Institute for Defense Analyses. Our model has only two parameters: the activation temperature of nociceptors and the critical threshold on the activated volume. When the spatial temperature profile is measurable, the two parameters can be determined from test data. We connect this dose-response relation to a temperature evolution model for electromagnetic heating. The resulting composite model governs the process from the electromagnetic beam deposited on the skin to the binary outcome of subject’s reflex response. We carry out non-dimensionalization in the time evolution model. The temperature solution of the non-dimensional system is the product of the applied power density and a parameter-free function. The effects of physical parameters are contained in non-dimensional time and depth. Scaling the physical temperature distribution into a parameter-free function greatly simplifies the analytical solution, and helps to pinpoint the effects of beam spot area and applied power density. With this formulation, we study the theoretical behaviors of the system, including the time of reflex, effect of heat conduction, biological latency in observed reflex, energy consumption by the time of reflex, and the strategy of selecting test conditions in experiments for the purpose of inferring model parameters from test data.
文摘In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β value of fluoropolymer, which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter β and irradiation temperature (T_i)of fluoropolymer is established as follows:β=2.2×10^(-3) T_g+4×10^(-4)(T_g-T_i)+0.206.values of some tluoropolymers calculated from the above expression are in agreement with the experimental values.
文摘Some polymers which are difficult to crosslink, even degrade, at room temperature can crosslink at high temperatures. Obviously, the irradiation temperature is closely related to the probability of radiation crosslinking or degradation reaction as well as the behaviors
文摘The dose-response curves obtained by premature condensed chromosome (PCC)and conventional cellular genetic methods can be represented by two linear equations. The ratiO of the slopes, Kpcc/KM,, is about 28. In comparison to the conventional method, the PCC method has many advantages; e,g. it is faster, simpler, more sensitive and accurate. Its significance in the study of radiation damage is also discussed.
文摘目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调查、身体测量和实验室检测。应用非条件逐步Logistic回归和限制性立方样条模型分析BMI与血脂异常患病关联及剂量-反应关系。结果最终共纳入3173例样本,武汉市江岸区居民超重、肥胖的标化患病率分别为31.30%和8.95%。血脂异常、高总胆固醇(TC)、高甘油三酯(TG)血症、高低密度脂蛋白(LDL-C)血症和低高密度脂蛋白(HDL-C)血症的标化患病率分别为20.49%、2.60%、9.78%、3.17%和6.08%。超重(OR=1.118,95%CI:1.083~1.154)和肥胖(OR=1.181,95%CI:1.123~1.243)与血脂异常患病显著相关。男性(χ^(2)=6.67,P<0.05)、女性(χ^(2)=6.07,P<0.05)、18~<45岁(χ^(2)=13.40,P<0.05)和45~<65岁(χ^(2)=8.02,P<0.05)人群的BMI与血脂异常患病呈非线性剂量-反应关系,随BMI升高,血脂异常患病风险逐渐增加继而又趋于平缓。而65岁及以上(χ^(2)=0.18,P>0.05)人群的BMI与血脂异常患病呈线性剂量-反应关系。结论BMI的连续变化和血脂异常的患病风险呈正相关的剂量-反应关系。血脂异常的指标预警防控工作需关口前移,应注重中青年的血脂防控工作,并通过倡导减轻体质量、进行早期预防和控制等措施,降低血脂异常患病风险。
