低剂量电离辐射对放射工作人员细胞遗传学影响

目的 分析低剂量电离辐射对放射工作人员细胞遗传学影响.方法 采用放射场所辐射剂量、个人剂量、细胞遗传学指标检测及流行病学横断面调查研究方法.结果 射线接触组染色体畸变率(0.16%)高于对照组(0.04%),染色体畸变检出率(17.05%)高于对照组(5.1%),微核率(1.0‰)高于对照组(0.2‰),微核检出率(48.06%)高于对照组(12.25%),差异均有统计学意义(x2=8.45,P＜0.01;x2=7.59,P＜0.01;x2=57.23,P＜0.01;x2=32.52,P＜0.01);不同年剂量、累积剂量组染色体畸变率、微核率与对照组比较,差异均有统计学意义;随着个人年剂量、累积剂量水平的增加,染色体畸变率、微核率、微核阳性检出率有增高趋势.结论 长期低剂量电离辐射,对淋巴细胞产生的辐射效应导致的染色体畸变率、微核率的增加并与放射人员个人累积吸收剂量密切相关.     

白藜芦醇对60Coγ射线离体照射人周围血淋巴细胞保护作用研究

目的 探讨白藜芦醇(RES)对60Coγ射线离体照射人周围血淋巴细胞的保护作用.方法 采集男性健康志愿者周围血分离培养淋巴细胞,设不加RES的照射对照组,照射前30 min分别给予RES 0.1、0.2和0.4 mmol/L的3个照射前给药组,及照射后立即分别给予RES 0.1、0.2和0.4 mmol/L的3个照射后给药组.用4 Gy60Coγ射线进行照射,采用淋巴细胞胞质分裂阻滞(CB)法和Annexin V-FITC/PI双染法分析淋巴细胞微核率和凋亡率的变化.结果 ①3个照射前给药组的微核率及凋亡率比照射对照组低(P ＜0.01 ～P＜0.001);②0.2、0.4 mmol/L照射后给药组微核率比照射对照组低(P＜0.05,P＜0.01),3个照射后给药组凋亡率比照射对照组低(P＜0.05～P＜0.01);③3个照射前给药组微核率均比3个照射后给药组低(P＜0.01～P＜0.001),0.4 mmol/L照射前给药组在抑制凋亡率方面强于0.4mmol/L照射后给药组(P＜0.05).结论 RES可以通过抑制60Coγ射线离体照射引起的人周围血淋巴细胞的微核率和凋亡率的升高,对辐射诱导的淋巴细胞DNA损伤起到防护作用,其辐射防护效果与RES的给药时间及给药剂量有关.     

辽宁省39年间93起放射事故分析

用胞浆阻滞微核法,观察到低剂量X线照射(0.075Gy)对大剂量X射线照射(1.5Gy)及N-甲基-N'-硝基-N-亚硝基胍(MNNG)诱导的双核淋巴细胞微核具有明显的抑制作用,微核细胞率的抑制率分别为48.6%及29.8%(P<0.01),微核率的抑制率分别为46.5%及33.5%(P<0.01),表明0.075GyX射线照射能诱导抗大剂量X线照射及MNNG损伤的适应性反应,该反应可能是由于低剂量照射刺激了某些酶系统,使DNA的修复能力增强所致。     

CB法微核实验检测细胞DNA损伤修复能力

目的 探讨一定剂量的x射线照射后双核淋巴细胞微核率作为检测细胞DNA损伤修复能力生物学指标的可行性。方法 采用CB法微核实验,检测人外周血离体培养24h后以0.5~4 Gy剂量X射线照射后的微核率,计算修复能力指数(DRC),建立以公认的辐射损伤模型和双核微核为观察终点的检测细胞DNA损伤修复能力的一种新方法。结果 CB法微核实验结果显示照射剂量和淋巴细胞微核率存在较紧密的相关性。随着辐射剂量增加,细胞微核率增大,细胞内微核个数增多,细胞死亡数亦增加。0.5 Gy剂量x射线照射后微核率明显增大,与0 Gy剂量组(对照组)相比,差异有统计学意义(t=2.64,P=0.03),阅片结果显示,两组实验的细胞死亡数较少,差异不明显。结论 从微核率,微核个数,死亡细胞数综合考虑,在实例验证基础上,本实验条件下,可选择0.5 Gy剂量X射线照射以检测细胞DNA损伤修复能力大小。     

慢性低剂量辐射小鼠模型的建立与评价

目的比较不同剂量X射线照射后实验小鼠生物学指标的变化,以建立辐射损伤动物模型。方法用三种辐射剂量率(0.04 Gy/h/d、0.08 Gy/h/d、0.12 Gy/h/d)的X射线对三组昆明小鼠(辐射剂量由低到高分为L、M、H组)进行连续7天全身照射,同时设立不接受辐射的对照组(NC),辐射后检测各组小鼠脏器指数、外周血细胞计数、骨髓有核细胞计数、血清MDA含量和SOD活性等指标的变化,同时比较辐射前后各组小鼠体质量和肝脏、脾脏指数的改变。结果照射后7天,L组小鼠体质量明显低于NC组以及M、H组(P0.05); M、H组小鼠脾脏指数显著低于NC组(P0.01)和L组(P0.05);不同剂量辐射组小鼠外周血WBC和骨髓有核细胞数量均较NC组显著降低(P0.05,P0.01);与NC组比较,M组小鼠血清MDA含量显著升高(P0.05)、SOD活性显著降低(P0.05)。结论慢性累积性低剂量辐射小鼠模型的最佳造模方法为辐射剂量率0.08 Gy/h/d、连续辐射7天,累积辐射剂量0.56 Gy。     

3例辐射事故受照者CB微核分析及生物剂量估算

[目的] 对河南新乡一起60Co源辐射事故中3例受照者进行了CB微核分析,并对其生物剂量进行估算.3例受照者A、B、C均为男性,受照时年龄分别为31、39和51岁,分别受照后24 d、44 d和96 d采血培养,进行CB微核分析和剂量估算.[方法] CB微核标本的制备方法为对3例受照者分别取0.3～0.4 ml肝素抗凝静脉血,加到4 ml含20%小牛血清和50 μg/ml PHA的混合培养液中,置37℃恒温培养箱中培养,培养至40～44 h,加入终浓度为6 mg/L的松胞素B,继续培养至72 h收获.常规制片,Giemsa染色.显微镜下观察双核淋巴细胞,并记录其微核数.结果以微核细胞率(CBCMN,‰)和微核率(CBMN,‰)表示,并估算剂量.生物剂量估算采用白玉书教授等建立的60Co γ射线照射离体人血诱发的CB微核的剂量曲线估算生物剂量.[结果] 照后24 d 3例受照者的CB微核率和CB微核细胞率均明显升高,由此估算的剂量分别为①3例受照者依据CBMN率估算的个体辐射剂量分别为0.97 Gy(A)、0.74 Gy(B)和0.58 Gy(C);②依据CBCMN率估算的个体辐射剂量分别为0.87 Gy(A)、0.64 Gy(B)和0.50 Gy(C).[结论] 本文用CBMN估算剂量与染色体"双+环"畸变剂量和物理剂量接近,与放射损伤的临床诊断亦相符合.说明CB微核分析估算事故照射受照者的照射剂量是准确可行的.而且本调查中照后取血时间对CB微核剂量的影响分析发现,照后44 d和96 d,3例受照者CB微核率和由此估算的剂量均明显下降.与国内外许多起辐射事故病例观察的结果一致.     

虾青素对60Coγ射线所致小鼠氧化损伤的保护作用

目的 探讨虾青素对60Coγ射线诱导的小鼠氧化损伤的保护作用.方法 50只昆明种小鼠随机分为5组,即对照组、模型组和虾青素高、中、低剂量组(10.2、2.0和4.0mg/kg).辐照前,各剂量组每日经口灌胃不同浓度的虾青素,模型组和对照组则给予等体积植物油,连续30天.30天后,除对照组外,其余各组给予8 Gy 60Coγ射线全身一次性照射.照射后第4天处死小鼠,取肝细胞进行彗星实验以观察细胞DNA损伤,制取肝匀浆测定MDA含量、SOD和GSH-Px活性,同时进行外周血粒细胞和骨髓有核细胞计数.结果 与对照组相比,模型组MDA含量显著升高(P＜0.01),SOD和GSH-Px活性显著降低(P＜0.01);与模型组相比,虾青素各组MDA含量显著降低(P＜0.01),SOD活性显著升高(P＜0.01),高剂量组GSH-Px活性显著升高(P＜0.01).模型组DNA损伤指标均显著高于对照组(P＜0.01),而虾青素各组DNA损伤显著低于模型组(P＜0.01),且随着虾青素剂量的增加,细胞拖尾率和OTM逐渐减少.与对照组相比,模型组粒细胞和骨髓有核细胞计数显著降低(P＜0.01),而虾青素各组粒细胞和中、高剂量组骨髓有核细胞显著高于模型组(P＜0.01).结论 虾青素对于辐射诱导的氧化损伤具有保护作用.     

枸杞多糖对慢性辐射小鼠细胞凋亡及bc1-2基因表达的影响

目的:探讨枸杞多糖(LBP)对辐射小鼠细胞凋亡及凋亡相关基因bcl-2表达的影响。方法:以水提取-乙醇沉淀法制备枸杞多糖,并制成0.8%的饲料,给予受试小鼠(枸杞多糖组)。正常对照组、辐射对照组给予普通饲料。除正常对照组外,另两组均用60Coγ射线对动物进行全身性照射,每天照射1次,每天照射剂量为0.084Gy,每周照射5d,连续照射6w,照射总剂量为2.52Gy。检测骨髓微核率、睾丸精母细胞染色体畸变、精子畸形率、肝细胞caspase-3mRNA表达水平、细胞凋亡及凋亡相关基因bc1-2表达等指标。结果:LBP可使辐射引起的微核率、染色体畸变、及精子畸形率显著降低,骨髓细胞增殖活性提高,凋亡率降低,使辐射小鼠bc1-2基因表达提高、caspase-3mRNA表达水平降低。结论:枸杞多糖的抗辐射作用与其调控细胞bc1-2基因表达,影响细胞凋亡有关。     

银杏叶片剂对γ射线诱发的小鼠PCE和生殖细胞微核率的影响

[目的 ]研究60 Co γ射线照射小鼠后 6d和 12d对骨髓嗜多染红细胞 (PCE)和生殖细胞微核的影响及银杏叶片的纠正作用。 [方法 ]清洁级ICR小鼠 48只随机分为 6组 :6d未辐射组 (阴性对照组 )、辐射组 (阳性对照组 )、银杏组 ;12d未辐射组 (阴性对照组 )、辐射组 (阳性对照组 )、银杏组。每只小鼠全身一次性 5 .0Gy剂量60 Co γ射线照射 ,未辐射组假性辐射。此后每天银杏叶片 10mg灌胃 ,连续 6d或 12d。于未次灌胃后次日 (第 7天和第 13天 )观察小鼠PCE和睾丸生殖细胞微核率。 [结果 ]灌胃 6d ,辐射组PCE和睾丸生殖细胞微核率显著高于未照射组 (P <0 .0 1,P <0 .0 5 ) ,银杏组PCE微核率显著低于辐射对照组 (P <0 .0 5 ) ,但睾丸生殖细胞微核率差异无显著性 (P >0 .0 5 )。灌胃 12d辐射组PCE微核率与未照射组比差异无显著性 (P >0 .0 5 ) ,但显著低于灌胃 6d辐射组 (P <0 .0 5 )。辐射组、银杏组睾丸生殖细胞微核率显著高于未照射组 (P <0 .0 5 ) ,分别与 6d组比有下降但无统计学意义。 [结论 ]辐射后第 7天小鼠PCE、睾丸生殖细胞具有遗传损伤作用 ,银杏叶片具有纠正辐射引起的损伤作用。辐射后第 13天PCE、睾丸生殖细胞的微核率趋向自然修复     

Radaway抗辐射胶囊对小鼠辐射损伤的保护作用

目的 观察Radaway抗辐射胶囊对小鼠γ射线辐射损伤的保护作用。方法 将120只雄性昆明小鼠随机分为I(外周血白细胞计数)、Ⅱ(骨髓细胞微核检测)、Ⅲ(骨髓DNA含量测定)3大组,每大组又随机分为高、中、低剂量组和辐射对照组。各组根据不同指标选择不同的照射时间均以同一剂量γ射线全身照射1次。结果 以3Gy剂量照射后第14天各剂量组的外周血白细胞计数均显著高于辐射对照组(P < 0.01);照射后第3天,中、低剂量组的骨髓细胞微核率显著低于辐射对照组(P < 0.01),低剂量组的骨髓DNA含量显著高于辐射对照组(P < 0.01)。结论 Radaway抗辐射胶囊对小鼠γ射线辐射损伤具有显著的保护作用。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Fatigue and health in a seafaring population

Background Occupational fatigue is relatively common withinthe general population and has been linked to reduced performance,injury and longer term ill-health. Despite growing acknowledgementof this problem in the maritime sector, little research hasbeen conducted into the risk factors, prevalence and consequencesof seafarers' fatigue. Aims To examine the prevalence of fatigue among seafarers, identifypotential risk factors and assess possible links with poor performanceand ill-health. Methods Cross-sectional questionnaire survey of seafarers workingin the offshore oil support, short-sea and deep-sea shippingindustries. A number of tools were used including the fatiguesubscale of the profile of fatigue-related symptoms, the CognitiveFailures Questionnaire, the General Health Questionnaire andthe SF36 General Health scale. Results In all, 1855 questionnaires were completed giving anoverall response rate of 20%. Fatigue symptoms were associatedwith a range of occupational and environmental factors, manyunique to seafaring. Reporting a greater number of risk factorswas associated with greater fatigue [e.g. OR = 2.53 (1.90–3.35)for those with three or four risk factors and OR = 9.54 (6.95–13.09)for those with five or more risk factors]. There was also astrong link between fatigue and poorer cognitive and healthoutcomes, with fatigue the most important of a number of riskfactors, accounting for 10–14% of the variance. Conclusions Seafarers' fatigue could impact on safety withinthe industry and may be linked to longer term individual ill-health.It can only be addressed by considering how multiple factorscombine to contribute to fatigue.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.