二氯苯醌对秀丽隐杆线虫胚胎细胞DNA的损伤作用

目的研究新型饮用水氯化消毒副产物二氯苯醌对秀丽隐杆线虫胚胎细胞的DNA损伤作用。方法提取秀丽隐杆线虫的胚胎细胞,分别暴露于0(溶剂对照)、0.781 25、3.125、12.5、50、200、800μmol/L含二氯苯醌的L-15液体培养基染毒1 h,并设阳性对照(含300μmol/L过氧化氢的L-15液体培养基染毒15 min)。采用单细胞凝胶电泳技术测定DNA损伤情况。结果 3.125~800μmol/L二氯苯醌暴露组彗星实验Olive尾矩值均高于溶剂对照组,差异有统计学意义(P0.05,P0.01);且随着二氯苯醌暴露浓度的升高,秀丽隐杆线虫胚胎细胞Olive尾矩呈上升趋势。结论二氯苯醌对秀丽隐杆线虫胚胎细胞的DNA具有损伤作用。     

氯化甲基汞对秀丽隐杆线虫运动和感觉功能的影响

目的分析神经毒物氯化甲基汞对模式生物秀丽隐杆线虫运动和感觉行为的影响,初步探讨利用秀丽隐杆线虫研究氯化甲基汞神经毒性的可能性。方法采用氯化甲基汞对L1期、L4期幼虫分别急性(30 min)染毒[终浓度分别为0(溶剂对照)~202.5μmol/L和0~1 200μmol/L]和慢性(24 h)染毒[终浓度分别为0(溶剂对照)~80μmol/L和0~150μmol/L]。测定半数致死浓度(LC50)及行为学指标。结果氯化甲基汞致L1期、L4期秀丽隐杆线虫的LC50(30 min)分别为(65.93±8.89)μmol/L和(206.71±35.43)μmol/L,LC50(24 h)分别为(11.59±0.79)μmol/L和(24.89±4.88)μmol/L,L1期秀丽隐杆线虫对氯化甲基汞的毒性较L4期敏感。随着氯化甲基汞暴露剂量的升高,急性和慢性染毒L1期、L4期秀丽隐杆线虫的弯曲频率和头部摆动频率均呈下降的趋势,基本运动能力呈减弱趋势,触碰反应呈迟钝的趋势。结论氯化甲基汞可抑制运动和感觉功能,秀丽隐杆线虫可用于氯化甲基汞神经毒性的研究。     

壬基酚对秀丽隐杆线虫的生殖毒性

目的研究壬基酚(nonylphenol,NP)对秀丽隐杆线虫的生殖毒性。方法将秀丽隐杆线虫暴露于终浓度分别为含0(溶剂对照)、0.01、0.1、1、10、100mg/LNP的培养基24 h,并设空白对照。检测NP对线虫的半数致死浓度(LC50)、后代数目、世代时间和精子发生相关基因spe-10、spe-15、folt-1、fer-1 mRNA的表达水平。结果 NP对线虫的LC50远高于100 mg/L。与溶剂对照组比较,各浓度NP暴露组秀丽隐杆线虫世代时间延长,差异均有统计学意义(P0.05);而后代数目无明显改变;且随着NP暴露浓度的升高,秀丽隐杆线虫世代时间呈延长趋势,后代数目呈下降趋势。与溶剂对照组比较,仅1、100 mg/L NP暴露组秀丽隐杆线虫spe-10 mRNA的表达水平降低,差异均有统计学意义(P0.05);而各浓度NP暴露组秀丽隐杆线虫spe-15、folt-1、fer-1 mRNA的表达水平均无明显改变;且随着NP暴露浓度的升高,秀丽隐杆线虫spe-10、folt-1、fer-1 mRNA的表达水平呈下降趋势。结论 NP抑制线虫精子发生相关基因spe-10的表达,对后代数目和世代时间影响较小,本实验结果表明运用线虫模型评价NP的生殖毒性,其基因表达的改变先于表型指标。     

蒽醌暴露对秀丽隐杆线虫的毒性作用

目的 研究蒽醌暴露对模式生物秀丽隐杆线虫的毒性作用,观察其对秀丽隐杆线虫急性致死效应、寿命、生殖能力及抗氧化酶的影响。方法 根据蒽醌的溶解度及急性毒性试验结果确定本研究剂量为0、8、20、50、125 μmol/L,另设1%二甲基甲酰胺（DMF）溶剂对照组,对同步化至L4期的秀丽隐杆线虫分别进行处理,测定其致死率、寿命、子代数目及抗氧化酶的变化。结果 蒽醌24 h急性暴露后,随剂量的增加,秀丽隐杆线虫致死率增加,20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比差异均有统计学意义（P<0.05或P<0.01）;8、20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比,超氧化物歧化酶（SOD）活力增加（均P<0.01）。蒽醌长期暴露后,125 μmol/L剂量组与1%DMF溶剂对照组相比子代数目减少（P<0.05）;20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比平均寿命明显减少（P<0.05或P<0.01）。结论 秀丽隐杆线虫暴露于蒽醌可对其致死率、寿命、生殖能力产生影响,并可激活其体内抗氧化酶,启动氧化防御系统。     

纳米二氧化钛毒性线虫模式生物评价

目的 利用模式生物--秀丽隐杆线虫探讨二氧化钛(TiO2)纳米颗粒的毒性作用,为建立线虫作为毒理学评价模型提供试验依据.方法 采用5,35,300 nm等3种粒径的二氧化钛对秀丽隐杆线虫以0.1,1.0,10.0 g/L等3个浓度染毒24 h,应用世代时间、后代数目、头部摆动频率和身体弯曲频率及体长等生殖、运动和发育的相关指标对纳米二氧化钛毒性作用进行综合评价.结果 与对照组比较,暴露于5 nm TiO2的线虫在中高浓度暴露组均出现生殖、运动和发育等多系统的异常(P<0.05);而暴露于35 nm TiO2的线虫仅在高浓度暴露组出现生殖、运动等指标的异常(P<0.05);暴露于300 nmTiO2时高浓度暴露组的线虫出现身体弯曲频率降低(P<0.05),其他浓度组未出现差异有统计学意义的改变.结论 纳米TiO2暴露可影响秀丽隐杆线虫运动、生殖和发育等多种系统,并与粒径和暴露浓度有关.     

锰铅镉复合暴露对人神经母细胞瘤细胞的毒性作用

目的探索重金属复合暴露对人神经母细胞瘤(SK-N-SH)细胞的毒性效应。方法将SK-N-SH细胞分别暴露于空白培养基(对照)和氯化锰(125、250、500、750、1 000、1 500、2 000、4 000、6 000μmol/L),乙酸铅(500、750、1 000、1 500、2 000、2 500、3 000μmol/L),氯化镉(5、10、15、20、30、40、60、80μmol/L)单一及二元、三元复合溶液24、48、96 h后,检测细胞存活率,计算锰、铅、镉的药物抑制浓度(IC)。其中,二元、三元复合溶液的浓度均为相应金属IC_(10)、IC_(20)、IC_(30)、IC_(50)的等毒效应比混合,分别用毒性单位法、混合毒性指数法对毒性效应进行评价。结果与对照组相比,不同浓度锰、铅、镉单独染毒不同时间SK-N-SH细胞的存活率均较低,除500μmol/L铅染毒24、96 h组和5μmol/L镉染毒24、48 h组外,差异均有统计学意义(P0.05);随着锰、铅、镉单独染毒浓度的升高和染毒时间的延长,SK-N-SH细胞的存活率均呈下降趋势。三种金属对SK-N-SH的细胞急性毒性依次为镉(IC_(50):38.728μmol/L)锰(IC_(50):442.739μmol/L)铅(IC_(50):1 624.850μmol/L)。同一金属不同染毒时间的IC_(50)排序均为96 h48 h24 h。锰和镉复合暴露对SK-N-SH细胞的联合毒性在24 h均表现为拮抗作用,在48 h均表现为协同作用;96 h在毒效应为IC_(10)、IC_(20)时均表现为部分相加作用,在IC_(30)、IC_(50)时均表现为协同作用。镉和铅对SK-N-SH细胞的联合毒性在24 h毒效应为IC_(10)、IC_(20)、IC_(30)时均表现为拮抗作用,在IC_(50)时表现为部分相加作用;在48 h毒效应为IC_(10)时表现为拮抗作用,在IC_(20)、IC_(30)、IC_(50)时均表现为部分相加作用;在96 h时均表现为部分相加作用。铅和锰对SK-N-SH细胞的联合毒性在24、96 h毒效应为IC_(50)时分别表现为简单相加、协同作用,其余均表现为部分相加作用。锰、铅、镉对SK-N-SH细胞的联合作用在24、96 h时均表现为部分相加作用;48 h时在IC_(10)、IC_(20)、IC_(30)均表现为协同作用,在IC_(50)时表现为部分相加作用。结论三种金属对SK-N-SH细胞的毒性均表现为随暴露时间的延长而增强的趋势。金属复合暴露呈现复杂的毒性效应,毒性效应与特定的金属组合、暴露时间、暴露浓度密切相关。     

秀丽线虫中铝暴露导致的多重毒害在世代间具有可转移特性

目的 研究铝暴露可能导致的多重毒性是否在世代间具有可传递特性.方法 利用模式生物秀丽线虫对于铝(2.5、75、200 μmol/L)暴露导致的寿命、发育、生殖、运动行为、行为可塑性等多种毒性及其在世代间的可传递性进行了研究.每个参数进行4组平行试验分析,寿命、发育、生殖与运动行为的分析每组20条线虫,行为可塑性的分析每组100条线虫.实验结果 都用SPSS 13.0软件进行分析.结果 数据显示,铝暴露能导致线虫出现多种表型和行为缺陷.与0 μmol/L浓度处理[平均存活天数,24 d;体长(1.30±0.05)mm;后代数目(278士20)个;世代时间(64.0±1.2)h;身体弯曲频率(45.8±3.0)次;头部摆动频率(109.33±7.30)次;行为可塑性(3±4)%]相比,低浓度铝(2.5 μmol/L)暴露即可导致平均存活天数(20 d)、体长[(1.12±0.02)mm;t=14.55,P＜0.01]、后代数目[(145±23)个;t=30.62,P＜0.01]、运动行为[身体弯曲频率(29.8±3.0)次;t=20.31,P＜0.01.头部摆动频率(95.8±6.2)次;t=16.43,P＜0.01]等严重缺陷,而高浓度的铝暴露还可以导致世代时间[75μmol/L,(67.0±1.7)h;t=8.92,P＜0.01.200 μmol/L,(70.7±1.5)h;t=15.13,P＜0.01]与行为可塑性[75 p,μmol/L,(16.5±3.0)%;t=27.11,P＜0.05.200 μmol/L,(23.5±4.0)%;t=16.43,P＜0.01]等的严重缺陷.而且,大部分高浓度铝暴露导致的缺陷可以从暴露当代传递到后代,使后代仍然呈现出严重表型与行为缺陷.在这些后代中,各表型与行为缺陷只能得到有限的恢复(如体长、后代数目与运动行为),或没有明显的恢复(如高浓度铝暴露引起的寿命缺陷).尤其是,铝引起的世代时间缺陷在子代中会变得更为严重.结论 在秀丽线虫中,铝暴露导致的针对表型与行为的多重毒害在很大程度上可以从当代动物传递到后代个体中.     

基于秀丽线虫的5种重金属生物毒性评价

目的评估5种重金属对秀丽线虫的生物毒性效应。方法将L1期秀丽线虫暴露于氯化汞(汞浓度为0、2.5、5.0、10、20、40、50μmol/L)、氯化铅(铅浓度为0、50、75、100、125、150、200μmol/L)、氯化镉(镉浓度为0、300、400、500、600、700、1 000μmol/L)、重铬酸钠(铬浓度为0、50、75、100、200、300、400μmol/L)、砷酸钠(砷浓度为0、50、100、200、300、400、600μmol/L)溶液中,加入E.coli OP50悬液10μl,暴露48 h。采用半数致死浓度(LC_(50))比较5种重金属对线虫生物毒性效应。结果 Hg~(2+)、Pb~(2+)、Cr~(6+)、As~(5+)、Cd~(2+)对秀丽线虫的LC_(50)及其95%CI分别为17.83μmol/L(95%CI=16.15～19.52μmol/L)、124.34μmol/L(95%CI=120.72～127.63μmol/L)、231.79μmol/L(95%CI=186.99～276.68μmol/L)、305.83μmol/L(95%CI=226.17～380.88μmol/L)、558.30μmol/L(95%CI=498.99～609.01μmol/L)。采用评估因子法获得Hg~(2+)、Cr~(6+)、As~(5+)、Pb~(2+)、Cd~(2+)的预测无效应浓度(PNEC)分别为3.60、12.06、22.95、25.67、62.50μg/L。结论 5种重金属对线虫的生物毒性效应依次为Hg~(2+)Pb~(2+)Cr~(6+)As~(5+)Cd~(2+)。     

十氯酮诱导氧化应激损伤对秀丽隐杆线虫精细胞影响

目的探讨十氯酮对雄性秀丽隐杆线虫精细胞的毒性效应及其与氧化应激损伤作用的关系。方法幼虫1期线虫分别暴露于4个剂量十氯酮(0.02、0.20、2.00、20.00μg/L)、对照组(M9溶液),48 h后,计数后代数目和观测世代时间;通过二氢荧光素乙酰乙酸(CM-H2DCFDA)探针法检测线虫体内活性氧(ROS)水平;荧光显微镜观测线虫远端顶细胞(DTC)荧光强度;二脒基苯基吲哚(DAPI)染色后计数性腺有丝分裂区生殖细胞数;显微镜明场下观测线虫精子畸形率和体外活化率。结果十氯酮高剂量组秀丽隐杆线虫后代数目为(255.00±13.72)个,明显低于对照组(335.60±21.31)个;十氯酮高剂量组秀丽隐杆线虫世代时间为(69.60±1.96)h,长于对照组(55.80±1.94)h,差异有统计学意义(P0.05)。与对照组比较,十氯酮2.00、20.00μg/L组线虫体内活性氧水平升高,各剂量十氯酮组线虫远端顶细胞荧光强度降低(P0.05)。对照组线虫有丝分裂区生殖细胞数目为(87.90±3.75)个、精子畸形率为(12.70±1.16)%、体外活化率为(77.00±9.82)%,20.00μg/L十氯酮组线虫有丝分裂区生殖细胞数目[(47.90±5.42)个]下降、精子畸形率[(84.00±7.29)%]明显上升、体外活化率[(8.70±2.41)%]明显下降。结论氧化应激损伤可能是十氯酮暴露后引发生殖毒性作用的重要机制。     

维生素E对邻苯二甲酸二丁酯细胞毒性的影响

目的 探讨邻苯二甲酸二丁酯(DBP)对小鼠淋巴瘤细胞(EL4)的毒作用及维生素E(VitE)对细胞的保护作用.方法 分别用10、100、500、1 000 μmol/L DBP作用细胞24 h,并且VitE进行干预,检测细胞增殖、乳酸脱氢酶(LDH)活力及丙二醛(MDA)含量.结果 DBP作用EL4细胞24 h,100～1 000 μmol/L DBP均能明显促进EL4细胞增殖.1 000 μmol/L DBP可明显升高EL4细胞上清液中LDH活力及MDA含量.与1 000 μmol/L DBP组比较,50 μmol/L VitE能显著降低细胞上清液中LDH活力及MDA含量.结论 DBP使EL4细胞产生氧化损伤,这可能与DBP的免疫毒性有关.     

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.