河南两起辐射事故受照者染色体畸变和CB微核分析及生物剂量估算

[目的 ]对 2 0 0 0年河南许昌“3 0 6”60 Co辐射事故 1例受照者 (A)和 2 0 0 0年河南开封“6 2 6”辐射事故 1例过量放射性核素内污染致γ射线照射受照者 (B)的外周血淋巴细胞染色体畸变和CB微核进行分析 ,并估算其生物剂量。 [方法 ]受照者“A”为男性 ,37岁 ,照后 15d取血培养。受照者“B”为女性 ,2 7岁 ,照后 3d取血培养。外周血淋巴细胞染色体和CB微核的标本制备采用常规方法 ,双盲法阅片 ,记录每个细胞中的染色体结构畸变数或微核数 ,结果以染色体畸变百分率或微核千分率表示。 [结果 ]“A”的双 环率为 ( 19 5± 2 0 ) % ,估算剂量均值为1 44Gy ,95 %可信限范围为 1 2 7～ 1 6 1Gy ;GB微核率为 ( 15 4 0 0± 12 41)‰ ,估算剂量均值为 1 43Gy ,95 %可信限范围为 1 35～ 1 5 1Gy。“B”的双 环率为 ( 0 6 7± 0 47) % ,估算剂量均值为0 15Gy ,95 %可信限范围为 0 0 6～ 0 2 3Gy ;CB微核率为 ( 2 7 33± 4 2 7)‰ ,估算剂量均值为 0 2 2Gy ,95 %可信限范围为 0 13～0 30Gy。 [结论 ]用染色体畸变和微核分析 ,受照者受照剂量的估算结果 ,与临床症状和物理剂量基本一致。对剂量小于 1Gy的照射 ,CB微核剂量高于染色体畸变剂量。在小剂量照射条件下 ,由于自发微核率高、个体差异大、群体     

鼻咽癌放疗患者染色体畸变率及微核率检测分析

目的 探讨鼻咽癌患者放疗前后外周血淋巴细胞染色体畸变率和微核率的变化。方法 采用微量全血培养法进行染色体畸变分析和微核检测。结果 鼻咽癌患者染色体畸变率、微核率均明显高于对照组(P <0.01),且放疗后染色体畸变率和微核率较放疗前显著增高(P <0.01)。结论 外周血淋巴细胞染色体畸变率和微核率可作为判断放疗敏感性和预测放疗后肿瘤转归的生物剂量计来进一步研究。     

快中子与60Co-γ射线诱发人淋巴细胞生物效应研究

目的 18MeV中子和60Coγ射线照射离体人血淋巴细胞,建立染色体畸变和淋巴细胞微核的剂量-效应曲线;计算中子染色体畸变和微核的相对生物效应.方法 中子和60Coγ射线照射离体人血,吸收剂量率都为O.2Gy/min,吸收剂量为0.5～3.O Gy.记录染色体型畸变和双核淋巴细胞的微核,分别对双着丝粒体+着丝粒环和微核做曲线拟合,并计算中子的RBE.结果 中子和60Coγ射线照射离体人血诱发的染色体畸变(双+环)和淋巴细胞微核,呈良好的剂量-效应关系.中子诱发染色体畸变和微核的RBE值都随吸收剂量的增加而减少,在0.5～3.O Gy 范围内,诱发染色体(双+环)的RBE值是3.59～1.77;诱发微核的RBE值是2.91-1.24.结论 快中子照射离体人血淋巴细胞产生的染色体畸变(双+环)和微核的剂量一效应关系都符合线性平方模型.中子与60Coγ射线相比较,在照射剂量较低时,有较高的生物效应.     

83例外照射事故人员染色体畸变及淋巴细胞微核的检查分析

本文报道了83例外照射事故人员的照射剂量，染色体畸变与淋巴细胞微核的检出结果，阐明了在急性小剂量照射时，染色体畸变率和淋巴细胞微核率随照射量的增加而增高，呈直线关系，相关检验表明与受照剂量有关，相关系数分别为0．9825和0．9675，拟合直线回归方程为y1=0.402*10^-2 0.0709*10^-2D,y2=0.4757*10^-2 0.0595*10^-2D，同时还探讨了染色体畸变细胞率与淋巴细胞微核率的相互关系。     

102例癌患者放化疗前后染色体畸变和微核率分析

目的 分析癌症患者治疗前后外周血染色体畸变和微核率的变化，为其临床防治提供依据。方法 收集2016—2021年间四川省疾病预防控制中心102例癌症患者治疗前后的体检资料，分析其外周血染色体畸变和微核率相关指标的变化。结果 治疗前后，放疗和放化疗患者外周血染色体畸变率和微核率差异有统计学意义（P <0.05），化疗患者外周血淋巴细胞染色体畸变率和微核率差异无统计学意义（P> 0.05）；放射治疗淋巴细胞染色体畸变率异常人数差异有统计学意义（P <0.001），淋巴细胞微核率异常人数差异有统计学意义（P <0.001）；化疗淋巴细胞染色体畸变率异常人数差异无统计学意义（P> 0.05）；淋巴细胞微核率异常人数差异无统计学意义（P> 0.05）。结论 放射治疗会导致患者外周血淋巴细胞染色体畸变率和微核率异常，医疗机构可将其作为监测放疗对患者损害的剂量指标，制订有效的应急预案，及时做好每个疗程的放射剂量评估。     

烹调油烟冷凝物对人外周血淋巴细胞的遗传毒性

目的研究烹调油烟冷凝物对离体外周血淋巴细胞染色体畸变率和微核率的影响。方法人外周血淋巴细胞离体培养24h后,加入油烟冷凝物4、6、8、10μl,进行染色体畸变试验和微核试验。结果和对照组相比,加入油烟冷凝物后细胞染色体畸变率显著性升高(P<0.05),与加入油烟冷凝物的剂量呈正相关(r=0.987)。各剂量组微核率无显著性变化。结论烹调油烟冷凝物可引起外周血淋巴细胞的染色体畸变,对微核的产生影响较小。     

银耳孢糖组分对~(137)Cs γ射线照射小鼠骨髓细胞染色体畸变及微核率的影响

目的研究银耳孢子发酵物提取的均一体多糖组分A-BTF对γ射线照射诱发的小鼠骨髓细胞染色体畸变和骨髓嗜多染红细胞微核率的影响。方法实验组照射前24 h腹腔注射银耳孢糖组分,对照组腹腔注射生理盐水,小鼠接受137Csγ射线照射后进行小鼠骨髓细胞染色体畸变及骨髓多染红细胞微核率观察。结果银耳孢糖组分ABTF实验组小鼠的染色体畸变率和微核率明显低于对照组,差异具有统计学意义(P0.01)。结论实验结果表明该均一体银耳孢糖组分A-BTF对γ射线辐射所致小鼠骨髓细胞损伤有明显的防护作用。     

电离辐射对放射工作人员细胞遗传学的影响

目的 探讨长期小剂量电离辐射对放射工作人员细胞遗传学的影响,评价职业性受照射人群集体生物剂量和细胞遗传学效应的相关性。方法 用培养、MC法分别测定放射工作人员外周血淋巴细胞染色体畸变,微核率。结果 放射工作人员染色体畸变阳性率为15.2%,微核阳性率为9.3%,差异有显著性。其中医用X射线诊断工作者染色体畸变与微核阳性率分别为14.9%、11.0%;小型密封源操作者染色体畸变、微核阳性率分别为17.1%、5.2%;工业X射线探伤者染色体畸变、微核阳性率分别为0、21.4%;工业X射线探伤者比小型密封源操作者微核阳性率显著增高;染色体畸变、微核阳性率均随工龄的增加显著增长;放射工作人员男性染色体畸变阳性率显著高于女性。结论 小剂量电离辐射对细胞遗传学的影响与射线种类、能量、工种、工龄、性别及累积剂量是密切相关的,淋巴细胞染色体畸变、微核阳性率越高职业性受照射人群集体生物剂量累积越多,慢性放射性损伤细胞遗传学效应就越明显。     

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。     

低剂量γ射线照射诱导小鼠骨髓细胞染色体畸变的适应性反应

目的探讨低剂量照射后不同攻击剂量对小鼠骨髓细胞染色体畸变的适应性反应.方法小鼠预先用137 Cs γ射线0.05 Gy(D1,预照射剂量)低剂量全身照射(低剂量照射组)、剂量率0.054 Gy/min,3 h后再接受0.7 Gy或1.0 Gy(D2,攻击剂量)全身照射、剂量率0.87 Gy/min,同时设单纯较大剂量组为对照组,观察骨髓细胞染色体畸变率.结果 0.05 Gy低剂量全身照射后3 h再接受0.7 Gy或1.0 Gy全身照射组,小鼠骨髓细胞染色体畸变率和单体断裂(ctb)均明显低于其相应对照组,而与对照组相比,低剂量照射组断片(ace)减少不明确.结论预先的低剂量辐射能够诱导小鼠骨髓细胞染色体畸变的适应性反应,从而使随后较大剂量辐射所致的染色体损伤减轻.     

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.     

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.     

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.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

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.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.