共查询到18条相似文献,搜索用时 8 毫秒
1.
Hart J 《Dose-response》2010,8(4):448-455
There is controversy as to whether low levels of radiation (i.e., < 5 rem) pose a health risk. This brief inquiry compares archived cancer mortality data in counties having relatively low (0-250 feet above sea level), medium (500-1000 feet above sea level), and high (3000+ feet above sea level) elevations also having corresponding greater natural background levels of radiation respectively. Cancer mortality was found to be lowest in the high elevation counties (mean = 58.2) followed by low elevation counties (67.5) and then medium elevation counties (70.4). Statistically significant differences were found between low -high elevations (p = 0.003), and medium - high elevations (p = 0.010), but not between low and medium elevations (p = 0.5). More rigorous research, with an accounting of confounding variables, is indicated. 相似文献
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This ecological inquiry compares cancer mortality rates in the U.S. to the predictor of natural background radiation (via land elevation means) along with eight other predictors thought to be associated with cancer mortality. Age-adjusted cancer mortality in 2006 was compared to the predictors of mean land elevation, percent of smokers, educational attainment, percent of population without health insurance, income, obesity, health perception, physical activity, and diet. Among the six predictors considered appropriate for multiple linear regression, three were found to be statistically significant; from strongest to weakest, these three were: smoking, land elevation, and educational attainment. The predictors of smoking and educational attainment have long been considered associated with cancer mortality. The finding that the predictor of land elevation / natural background radiation is inversely related to cancer mortality is another piece of evidence supporting the theory of radiation hormesis. In this study, land elevation / natural background radiation ranked second in predictive strength regarding cancer mortality, behind smoking and ahead of educational attainment. Since this is an ecological inquiry, no causal inferences can be made. 相似文献
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Hart J 《Dose-response》2011,9(3):348-355
A previous study compared cancer mortality in the six lowest versus six highest elevations in the U.S. for all races. This study looks at a single race since death rates tend to vary by race. In this ecological study, cancer mortality rates were compared between low and high states for a race that had sufficient number of counties reporting mortality data, that is, the white race. The average cancer mortality rate for low elevation counties was 73.47 + 18.35 compared to 53.90 + 13.76 for high elevation counties, a difference that was statistically significant (p < 0.0001), with a very large effect size (of 1.2). Higher elevation counties showed less cancer mortality rates for a single race compared to lower elevation counties, suggesting the presence of radiation hormesis. Further rigorous research is indicated to verify or refute these findings. 相似文献
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There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation. 相似文献
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目的:探讨直肠癌调强适形放射治疗的可行性及优势。方法选取2007年6月~2014年12月在本院治疗的80例行放射治疗的直肠癌患者作为研究对象,随机分成两组,各40例。观察组行调强适形放射治疗,放疗剂量为50 Gy;对照组行常规放射治疗,放疗剂量为46~48 Gy,比较两组的治疗效果、术后并发症和早期不良反应发生率。结果两组的治疗效果比较,差异无统计学意义(P>0.05)。观察组的不良反应发生率为52.5%,多为Ⅰ~Ⅱ级不良反应,Ⅲ级以上不良反应发生率为2.5%。观察组的直肠反应发生率为25.0%,显著低于对照组的80.0%,差异有统计学意义(P<0.05)。观察组的生殖器反应发生率为37.5%,显著低于对照组的52.5%,差异有统计学意义(P<0.05)。观察组的保肛率为70%,显著高于对照组的25%,差异有统计学意义(P<0.05)。结论调强适形放射治疗能够提高肛门括<肌的保留机会,减少治疗的毒性反应,更好地保护直肠周边邻近的正常组织器官。 相似文献
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Gary M. Marsh Ada O. Youk Peter Morfeld James J. Collins J. Morel Symons 《Regulatory toxicology and pharmacology : RTP》2010
Three of us (G.M., A.Y., and P.M.) performed reanalyses of the National Cancer Institute cohort study on nasopharyngeal cancer (NPC) risk among formaldehyde exposed workers (Hauptmann et al., 2004). Both reanalyses (Marsh and Youk, 2005 and Marsh et al., 2007) were published in this journal. However, the mortality follow-up performed by the NCI working group reported in two publications by Hauptmann et al., 2003 and Hauptmann et al., 2004 was later stated to be incomplete (Beane Freeman et al., 2009a and Beane Freeman et al., 2009b). This incomplete follow-up may impact the validity of the results of our reanalyses. At this time, corrected estimates for solid cancer mortality risks including NPC as reported in Hauptmann et al. (2004) have not been provided as an erratum by the authors or reported anywhere else to our knowledge. We would like to inform readers about these issues and ask for a prompt corrigendum of the 2004 publication by the NCI working group since this study has played such a prominent role in causal evaluations. 相似文献
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Kazuhiro Nogawa Yuuka Watanabe Sayaka Sakuma Masaru Sakurai Muneko Nishijo Masao Ishizaki Yuko Morikawa Teruhiko Kido Hideaki Nakagawa Yasushi Suwazono 《Journal of applied toxicology : JAT》2022,42(9):1458-1466
The relationship between cadmium exposure, exposure-related renal tubular dysfunction, and mortality have been reported, mainly in the residents of Cd-contaminated areas in Japan. The aim of this study was to establish the cause–effect relationship between renal tubular dysfunction and cancer mortality in the general population in non-contaminated areas. A 19-year cohort study was conducted in 1110 men and 1703 women in 1993 or 1994, who lived in three cadmium-non-contaminated areas. Mortality risk ratios of urinary β2-microglobulin (β2MG) and N-acetyl-β-glucosaminidase (NAG) for all malignant neoplasms and specific cancers were estimated using the Fine and Gray competing risks regression model. Significant hazard ratios (HRs) for liver and pancreas cancer were observed for NAG (liver: HR corresponding to an increase of 1 IU/g cr, 1.10, 95%CI, 1.02–1.19, pancreas: HR, 1.10, 95%CI, 1.02–1.19) in men. In women, a negative HR was observed for NAG (lung cancer: HR 0.80, 95% CI, 0.67–0.96) and for β2MG (all malignant neoplasms: HR, 0.97, 95% CI, 0.93–1.00). The present study indicated that renal tubular dysfunction was significantly related to mortality in the general population of cadmium-non-contaminated areas in Japan. 相似文献
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John Hart 《Dose-response》2013,11(1):41-48
There are a number of variables that are correlated with land elevation. Land elevation, and in particular, its surrogate variables such as natural background radiation, can be studied in relation to cancer rates. The present ecological study focuses on three such variables correlated with land elevation: natural background radiation (NBR), oxygen concentration (OC), and barometric pressure (BP). In addition, the study uses a novel approach for determining median land elevation values from which the surrogated variables are estimated. Inverse correlations were observed for NBR while direct correlations were found for OC and BP suggesting the presence of a protective effect with all three variables. Further study is indicated to either verify or refute these findings. 相似文献
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目的:比较替加氟与氟尿嘧啶治疗胃癌的临床疗效和安全性。方法:将62例胃癌患者随机分为观察组(32例)和对照组(30例)。观察组患者给予替加氟片68片,口服,每日3次,3个月为一疗程,休息1个月后重复下个疗程;对照组患者给予氟尿嘧啶注射液108片,口服,每日3次,3个月为一疗程,休息1个月后重复下个疗程;对照组患者给予氟尿嘧啶注射液1020 mg加入0.9%氯化钠注射液250 ml中,静脉滴注,每日1次,10 d为一疗程,休息20 d后重复下个疗程。两组患者均治疗1年后评价疗效。随访所有患者治疗1年、2年生存率和中位生存期,毒性反应及治疗费用。结果:两组患者总有效率,1年、2年生存率,中位生存期比较,差异均无统计学意义(P>0.05)。观察组患者除恶心、呕吐、腹泻、血小板降低发生率显著低于对照组外,其他不良反应发生率与对照组比较,差异均无统计学意义(P>0.05)。结论:替加氟与氟尿嘧啶治疗胃癌疗效相当,均可有效改善患者生存质量,但替加氟安全性优于氟尿嘧啶。 相似文献
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目的:探讨自拟中药煎剂灌肠治疗宫颈癌放疗致放射性直肠炎的临床疗效.方法:将2017年9月至2020年3月重庆大学附属肿瘤医院收治的120例宫颈癌放疗致放射性直肠炎患者采用随机数字表法分为中药治疗组和对照组,每组60例.中药治疗组患者给予自拟中药煎剂(葛根30 g,黄芩30 g,黄连30 g,白头翁30 g,地榆15 g... 相似文献
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OBJECTIVE: To determine whether the National Cancer Institute's (NCI) recent suggestion of a causal association between formaldehyde exposure and mortality from nasopharyngeal cancer (NPC) is robust with respect to alternative methods of data analysis and alternative categorizations of formaldehyde exposure. METHODS: The original authors provided the cohort data. We computed U.S. and local county (regional) rate-based standardized mortality ratios (SMRs) and internal cohort rate-based relative risks (RR) by categories of four formaldehyde exposure metrics (highest peak, average intensity, cumulative, and duration of exposure), using both NCI categories and an alternative categorization based on tertiles of all NPC deaths among exposed subjects. We computed SMRs and RRs for each of 10 study plants and by plant group (Plant 1 (n = 4261) vs. Plants 2-10 (n = 21,358)). RESULTS: Six of 10 NPC deaths observed in the NCI study occurred in only one plant (Plant 1) and the remaining four cases occurred individually in four of the other nine plants studied. A large, statistically significant, regional rate-based NPC SMR of 10.32 (95% CI = 3.79-22.47) among formaldehyde-exposed workers in Plant 1 contrasted sharply with a 35% deficit in NPC deaths (SMR = .65, 95% CI = .08-2.33) among exposed workers in Plants 2-10 combined. The statistically significant exposure-response relationship with formaldehyde and NPC reported in the NCI study for highest peak exposure was driven entirely by a large, statistically significant excess NPC risk in Plant 1 for the highest peak exposure category (4+ ppm). For the remaining nine plants, RRs for all non-baseline highest peak exposure categories were less than 1.0, and we observed no evidence of an exposure-response relationship. Most of the observed NPC excesses for the non-baseline categories of the other exposure metrics (average intensity, cumulative, and duration of formaldehyde exposure) were concentrated in Plant 1, and by contrast to the NCI findings, none of the corresponding exposure-response relationships was statistically significant. CONCLUSIONS: Overall, our reanalysis provided little evidence to support NCI's suggestion of a causal association between formaldehyde exposure and mortality from NPC. NCI's conclusion of a possible causal association was driven heavily by anomalous findings in one study plant (Plant 1). An independent and larger study of Plant 1 by the current authors concluded the NPC excess was not associated with formaldehyde exposure. Our findings cast considerable additional uncertainty regarding the validity of NCI's suggested causal association. 相似文献
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目的:观察小剂量紫杉醇+顺铂(TP)方案联合三维适形放疗治疗老年局部晚期非小细胞肺癌(NSCLC)的疗效和安全性。方法:46例老年局部晚期NSCLC患者均给予紫杉醇注射液150 mg/m2,静脉滴注,d1+顺铂注射液25 mg/m2,静脉滴注,d2-4+三维适形放疗照射肺部原发灶和肺门、纵膈淋巴结受累区,常规照射2 Gy/次,5次/周,剂量达40 Gy/20次后缩野,避开脊髓继续照射,总量达6065 Gy/3065 Gy/3033次,有锁骨上淋巴结转移者同时加野放疗。化疗前6、12 h分别给予地塞米松10 mg,口服;化疗前0.5 h给予甲氰咪胍0.4 mg,静脉滴注;化疗前0.5 h给予苯海拉明40 mg,肌肉注射。3周为1个周期,至少2个周期后评价疗效及毒性反应,并随访生存率。结果:所有患者接受至少2个周期的治疗后总有效率为73.9%,疾病控制率为89.1%。主要毒性反应为骨髓抑制,恶心、呕吐,放射性食管炎,放射性肺炎,但患者均可耐受。随访结束后14例生存,生存率为43.8%。结论:小剂量TP方案联合三维适形放疗治疗老年局部晚期NSCLC的疗效较显著,且安全性较好,可提高老年患者生存质量,但其远期疗效有待进一步观察。 相似文献
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To investigate trends in the sex odds before and after the Chernobyl accident, gender-specific annual birth statistics were obtained from the Czech Republic, Denmark, Finland, Germany, Hungary, Norway, Poland, and Sweden between 1982 and 1992. For parts of Germany, annual birth statistics and fallout measurements after Chernobyl are available at the district level. Trend models allowing for discontinuities of the male birth proportions are suggested. Superimposed on a downward trend in male proportions there was a jump in 1987 with a sex odds ratio of 1.0047 (95%-confidence interval: 1.0013–1.0081, p = 0.0061). A positive association of the male proportion in Germany between 1986 and 1991 with radioactive exposure at the district level is reflected by a sex odds ratio of 1.0145 per mSv/a (1.0021–1.0271, p = 0.0218). These findings suggest a possible long-term chronic influence of the Chernobyl Nuclear Power Plant accident on the human sex odds at birth in several European countries. 相似文献
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目的:探讨国产与进口奥沙利铂在直肠癌术后化疗中的安全性与有效性,指导临床用药。方法:对同期收治的TNMⅡ和Ⅲ期直肠癌患者共97例,随机分为国产奥沙利铂(奥沙利铂注射液)组52例,和进口奥沙利铂(乐沙定)组45例,进行术后辅助化疗,采用FOLFOX4方案,观察、记录患者的不良反应及术后局部复发、远处转移及生存情况,进行统计学分析。结果:两组患者化疗不良反应的差异无显著性意义(P〉0.05),3年后的局部复发及存活率存在一定的差异。结论:国产奥沙利铂使用仍然是安全、有效的,其3年生存率较高;对有经济条件的患者,可以考虑使用进口奥沙利铂,对患者整体术后治疗是有益的。 相似文献
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目的:比较替吉奥联合奥沙利铂与单用替吉奥治疗晚期胃癌的临床疗效和安全性。方法:选择我所收治的晚期胃癌患者72例,随机均分为观察组和对照组。对照组患者采用替吉奥单用治疗,给予替吉奥40 mg/m2,早晚各1次口服;观察组患者采用替吉奥联合奥沙利铂治疗,给予奥沙利铂130 mg/m2,静脉滴注,d1,并给予替吉奥40 mg/m2,早晚各1次口服。两组患者均每3周为1个治疗周期,连续治疗2个周期。比较两组患者治疗后的近期疗效、生存期及不良反应情况。结果:观察组患者治疗的有效率和疾病控制率均显著高于对照组,两组比较差异均有统计学意义(P<0.05);观察组患者的中位生存期显著长于对照组,两组比较差异有统计学意义(P<0.05)。观察组患者外周神经毒性发生率显著高于对照组,两组比较差异有统计学意义(P<0.05);观察组患者其他方面的不良反应发生率均略高于对照组,但两组比较差异均无统计学意义(P>0.05)。结论:替吉奥联合奥沙利铂相比单用替吉奥治疗晚期胃癌,可提高临床疗效及患者的生存质量,且安全性可接受。 相似文献