乙苯对HEI-OC1细胞增殖及氧化应激水平的影响

目的:研究乙苯染毒后耳蜗毛细胞株（HEI-OC1）细胞增殖及氧化指标的变化。方法:于2019年7至12月,设置乙苯浓度分别为0、30、60、90、300、600、900 μmol/L和3、6、9、10 mmol/L,共11个浓度组,用CCK-8法测定乙苯染毒24 h后HEI-OC1细胞增殖活性;以0、1、2、4、8、1...     

氧化损伤对耳蜗毛细胞Caspase-3和Caspase-9蛋白表达水平的影响

为研究氧化应激损伤耳蜗毛细胞Caspase-3、Caspase-9蛋白的表达水平,以探讨氧化应激诱发毛细胞凋亡的机制,将处于对数生长期的耳蜗毛细胞(HEI-OC1细胞)分别暴露于含终浓度为0(对照)、50、100、200μmol/L过氧化氢的DMEM高糖培养基24 h,以构建毛细胞氧化应激损伤模型。检测毛细胞内丙二醛(MDA)含量及Caspase-3和Caspase-9蛋白的表达水平。结果显示,与对照组比较,各浓度过氧化氢染毒组HEI-OC1细胞内MDA的含量均增高,差异有统计学意义(P0.01);且随着过氧化氢染毒浓度的升高,HEI-OC1细胞内MDA的含量呈上升趋势。与对照组比较,各浓度过氧化氢染毒组HEI-OC1细胞内Caspase-3和Caspase-9蛋白的表达水平均增高,差异有统计学意义(P0.05);且随着过氧化氢染毒浓度的升高,HEI-OC1细胞内Caspase-3和Caspase-9蛋白的表达水平均呈先上升后下降的趋势。提示氧化应激损伤可诱导耳蜗毛细胞的凋亡,但凋亡水平随氧化应激损伤程度的加重而呈先升高后下降的趋势。     

不同剂量亚砷酸钠暴露不同时间对HaCaT细胞活性氧的影响

目的 探索不同剂量亚砷酸钠暴露不同时间对诱导人永生化角质形成(HaCaT)细胞活性氧(ROS)产生的影响以及低剂量亚砷酸钠预处理HaCaT细胞对诱导ROS水平改变的时间效应.方法 设未预处理组[分别加入终浓度为0(对照)、0.15、0.6、2.5、10 μmol/L的亚砷酸钠染毒8、24、72 h]和预处理8h组(加入0.15μmol/L亚砷酸钠预处理8h后,加入10 μmol/L亚砷酸钠染毒8h)及预处理24 h组(加入0.15 μmol/L亚砷酸钠预处理24 h后,加入10 μmol/L亚砷酸钠染毒8h).利用2’,7’-二乙酰二氯荧光素(DCFH-DA)通过流式细胞仪检测细胞内ROS水平.结果 与对照组比较,各浓度亚砷酸钠染毒8h和0.6、2.5、10μmol/L亚砷酸钠染毒24 h及0.6、2.5 μmol/L亚砷酸钠染毒72 h后HaCaT细胞内ROS水平均较高,而0.15、10μmol/L亚砷酸钠染毒72 h后HaCaT细胞内ROS水平均较低,差异有统计学意义(P＜0.05).亚砷酸钠染毒8h时,HaCaT细胞内ROS水平达到峰值;之后,低剂量(0.15、0.6 μmol/L)亚砷酸钠染毒组HaCaT细胞内ROS水平于24 h下降,72 h有所回升,而高剂量(≥2.5 μmol/L)亚砷酸钠染毒组HaCaT细胞内ROS水平则呈持续下降.预处理8h组HaCaT细胞内ROS水平高于预处理24h组,差异均有统计学意义(P＜0.05);与10 μmol/L亚砷酸钠染毒未预处理HaCaT细胞8h组比较,预处理8h组HaCaT细胞内ROS水平较高,预处理24 h组HaCaT细胞内ROS水平较低,差异均有统计学意义(P＜0.05).结论 HaCaT细胞急性暴露于亚砷酸钠后能够引起HaCaT细胞内ROS产生增加,而不同剂量亚砷酸钠暴露诱导HaCaT细胞ROS水平的改变与暴露时间密切相关,且低剂量亚砷酸钠暴露对HaCaT细胞产生的适应性反应可能取决于其作用时间.     

1,2-二氯乙烷对体外培养SW620细胞增殖和细胞周期及凋亡的影响

目的 探讨1,2-二氯乙烷(1,2-DCE)对体外培养细胞周期、凋亡和增殖能力的影响.方法 不同浓度1,2-DCE染毒0.5或1h,噻唑蓝(MTT)法检测活细胞相对数和相对活力,流式细胞术(FCM)分析细胞周期和凋亡情况.结果 MTT法检测发现,随1,2-DCE染毒剂量的增加和染毒时间的延长,细胞相对存活率逐渐降低.与二甲亚砜(DMSO)组比较,染毒0.5 h,25、75、100、125、150、175、200 μmol/L 1,2-DCE组的细胞相对存活率降低,差异均有统计学意义(P＜0.05或P＜0.01);染毒1h,75、100、125、150、175、200 μmol/L 1,2-DCE组的细胞相对存活率降低,差异均有统计学意义(P＜0.05或P＜0.01);与0.5 h各组比,175μmol/L组染毒1h的细胞相对存活率降低,差异有统计学意义(P＜0.01);增殖曲线经标准化拟合后发现,染毒0.5 h,1,2-DCE的最适IC50为89.41 μmol/L,95％的可信区间为85.23～93.79μmol/L;染毒1h,1,2-DCE的最适IC50为87.68 μmol/L,95％的可信区间为83.71～91.82 μmol/L.FCM法检测发现,与对照组比较,1,2-DCE染毒1h,25、50、100、150、200 μmol/L组的G0/G1期比例降低,25、50、100 μmol/L组的S期比例降低,25、50、100、150、200 μmol/L组的G2/M期比例升高,差异均有统计学意义(P＜0.05或P＜0.01);但各组均不引起细胞凋亡.结论 1,2-DCE能够抑制体外培养SW620细胞增殖,使细胞周期停滞在G2/M期,但不诱导细胞凋亡.     

AMPK-mTOK信号通路参与百草枯致PC12细胞的自噬抑制作用

目的探讨AMPK-mTOR信号转导通路在百草枯(paraquat,PQ)诱导大鼠肾上腺髓质嗜铬细胞瘤细胞(PC12)自噬异常中的调控作用。方法用终浓度0、25、50、100、200、300、400 μmol/L PQ处理PC12细胞24 h,300 μmol/L PQ处理细胞不同时间(6、12、24、48 h),四甲基偶氮唑蓝(MTT)检测细胞相对存活率,确定剂量/时间-效应关系;终浓度0、100、200、300 μmol/L PQ处理细胞24 h,分光光度法检测培养上清中乳酸脱氢酶(LDH)活力;二氯荧光素双醋酸盐(DCFH-DA)法检测细胞内活性氧(ROS)水平;单丹磺酰尸胺(MDC)染色法观察自噬溶酶体的表达及分布变化;免疫荧光(IF)检测微管相关蛋白1轻链3(LC3)表达水平;免疫印迹法(Western blot)检测自噬相关蛋白LC3Ⅱ、p62、Beclin1及AMPK-mTOR信号通路蛋白p-AMPK、p-mTOR表达水平。结果与对照组比较,100、200、300、400 μmol/L PQ染毒组的细胞存活率明显降低,且呈剂量依赖关系,差异有统计学意义(P<0.05)。300 μmol/L PQ处理细胞不同时间(6、12、24、48 h),细胞存活率随染毒时间的延长而下降,其中12、24、48 h染毒组的差异有统计学意义(P<0.05)。与对照组比较,100、200、300 μmol/L PQ染毒组细胞上清液中LDH活力明显升高,细胞内ROS荧光强度明显增高,差异有统计学意义(P<0.05);MDC染色结果显示,PQ染毒组的自噬溶酶体在核周分布密度降低、荧光强度减弱、自噬水平降低;免疫荧光结果显示,PQ染毒组的LC3荧光强度减弱,细胞自噬水平下降,与MDC染色结果一致。Western blot结果显示,与对照组比较,PQ染毒组的自噬相关蛋白LC3Ⅱ、Beclin1表达水平均明显降低,而p62蛋白表达水平升高,差异有统计学意义(P<0.05)。200、300 μmol/L PQ染毒组的p-AMPK蛋白表达水平降低,p-mTOR蛋白表达水平升高,差异有统计学意义(P<0.05)。结论PQ致PC12细胞损伤过程中,细胞自噬水平降低,AMPK-mTOR信号通路发挥调节作用。     

铅镉联合染毒对小鼠初级精母细胞的毒性效应

目的研究乙酸铅和氯化镉对小鼠初级精母细胞(GC-2 spd)的联合毒性效应。方法将处于对数生长期的GC-2 spd细胞分别暴露于0(对照),不同浓度(10、20、40、80μmol/L)乙酸铅和(或)不同浓度氯化镉(1、2、4、8、16μmol/L)染毒24 h,采用CCK-8法检测细胞的存活率。采用活性氧(ROS)试剂盒检测20μmol/L乙酸铅及500μmol/L ROS保护剂N-乙酰半胱氨酸(NAC)分别与不同浓度氯化镉(0、1、2、4、8、16μmol/L)联合染毒24 h后的ROS水平。结果与对照组相比,20μmol/L乙酸铅染毒组GC-2 spd细胞的存活率上升,40、80μmol/L乙酸铅染毒组和2、4、8、16μmol/L氯化镉染毒组的细胞存活率均下降,差异均有统计学意义(P0.05);而10μmol/L乙酸铅染毒组和1μmol/L氯化镉染毒组的细胞存活率均无明显改变。与对照组相比,除10μmol/L乙酸铅+1μmol/L氯化镉染毒组和20μmol/L乙酸铅+1μmol/L氯化镉染毒组GC-2 spd细胞的存活率升高外,其他联合染毒组的细胞存活率均降低,差异均有统计学意义(P0.05);而20μmol/L乙酸铅+2μmol/L氯化镉组GC-2 spd细胞的存活率无明显变化。与相应浓度氯化镉单独染毒组相比,1μmol/L氯化镉+10、20μmol/L乙酸铅染毒组GC-2 spd细胞的存活率均升高,而1μmol/L氯化镉+40、80μmol/L乙酸铅染毒组的细胞存活率均降低,差异均有统计学意义(P0.05);仅2μmol/L氯化镉+20μmol/L乙酸铅染毒组的细胞存活率升高,而2μmol/L氯化镉+40、80μmol/L乙酸铅染毒组的细胞存活率降低,差异有统计学意义(P0.05);16μmol/L氯化镉+10、20、40、80μmol/L乙酸铅染毒组的细胞存活率均无明显变化,细胞基本全部死亡。与对照组相比,各浓度氯化镉染毒组GC-2 spd细胞的ROS水平均上升,差异有统计学意义(P0.05);与相应浓度氯化镉单独染毒组相比,500μmol/L NAC与不同浓度氯化镉联合染毒组、20μmol/L乙酸铅与不同浓度氯化镉联合染毒组GC-2 spd细胞的ROS水平均下降,差异有统计学意义(P0.05)。结论乙酸铅和氯化镉对GC-2 spd细胞毒性具有交互作用,表现为乙酸铅对低浓度氯化镉的GC-2 spd细胞毒性具有拮抗作用,对高浓度氯化镉的GC-2 spd细胞毒性具有协同作用。     

氧化应激损伤对内耳毛细胞内游离钙离子和钙调蛋白表达的影响

目的通过分析氧化应激损伤的内耳毛细胞内游离Ca~(2+)浓度和钙调蛋白(CaM)表达水平,探讨感音性耳聋的氧化应激损伤机制。方法采用不同浓度(50μmol/L、100μmol/L、200μmol/L)双氧水染毒培养内耳毛细胞,24 h后检测细胞过氧化氢酶(CAT)活性,Fluo-3 AM荧光探针定量检测细胞内Ca~(2+)浓度,免疫荧光法分析CaM表达水平。结果氧化损伤的毛细胞CAT活性明显下降,随着染毒浓度的增加下降更明显(F=689.9,P0.01);氧化损伤毛细胞游离Ca~(2+)浓度随着染毒浓度的增加而增加(F=716.107,P0.01);氧化损伤的毛细胞CaM表达水平明显增加,50μmol/L和100μmol/L H_2O_2染毒组随浓度增加表达增强,但200μmol/L H_2O_2染毒组表达水平有所回落(F=732.727,P0.01)。结论氧化应激损伤导致毛细胞内游离Ca~(2+)浓度和CaM表达增加诱发细胞凋亡是多类型感音性耳聋的重要发病机制,严重的氧化应激损伤可抑制细胞CaM表达。     

锰染毒对大鼠肾上腺嗜铬瘤细胞活性氧生成和miR-133b表达的影响

目的 研究锰对大鼠肾上腺嗜铬瘤细胞(PC12)活性氧(ROS)的生成和miR-133b表达的影响.方法 调整PC12细胞密度约为1×106/ml,以0(对照)、300、600 μmol/L MnCl2分别染毒PC12细胞72 h,采用DCFH-DA荧光探针检测ROS生成情况;以0(对照)、100、300 μmol/L ...     

活性氧在苯醌致HL-60细胞增殖过程中的作用

目的 探讨活性氧(ROS)在苯醌(BQ)引起HL-60细胞增殖过程中的作用.方法 取对数生长期的HL-60细胞,分为对照组(PBS处理细胞)、BQ染毒组(3 μmol/L BQ染毒)、过氧化氢酶(CAT)+BQ染毒组(3 μmol/L BQ染毒前加2000 U/ml CAT),用2'-7'-二氯荧光黄双乙酯(DCFH-DA)方法检测细胞内产生ROS的量,alamar blue法检测细胞增殖率.结果 BQ染毒组细胞内ROS的量(13.10±0.15)较对照组(11.32±0.09)明显增加.差异有统计学意义(P<0.05),并且该染毒组细胞增殖率(185%±30.00%)较对照组(100%±0.00%)明显增加,差异亦有统计学意义(P<0.05);与BQ染毒组相比,CAT+BQ染毒组细胞内ROS的量(10.29±0.24)和细胞增殖率(93.87%±10.00%)均明显降低,差异有统计学意义(P<0.05).结论 在BQ致HL-60细胞增殖过程中,ROS可能起着比较重要的作用.     

溴氰菊酯对PC12细胞活性氧生成的影响

目的 研究溴氰菊酯(DM)对大鼠肾上腺嗜铬细胞瘤(PC12)细胞活性氧(ROS)生成的影响.方法 对培养的PC12细胞分别进行处理:(1)终浓度为0、10和100 μmol/L的DM分别处理PC12细胞1、6和12 h(两因素析凶设计);(2)终浓度为0、10和100;μmol/L的DM分别处理PC12细胞1、6、24h或24、48 h;(3)PC12细胞分别在终浓度为10mmol/L乙酰半胱氨酸(NAC)预处理2 h、终浓度为500 μmol/L的DL-甲硫氨酸磺酰亚胺(BSO)及终浓度为40 μmol/L的叔丁基对苯二酚(tBHQ)预处理16 h,再给予10 μmol/LDM作用6ho所有处理结束时,用2',7'-二氯荧光黄双乙酸酯(DCFH-DA)探针法测定细胞ROS含量.结果 DM诱导ROS生成呈剂量和时间效应关系.10 μmol/L DM处理组PC12细胞增加ROS的DCF荧光强度,是溶剂对照组的2.24倍,差异有统计学意义(P<0.01).而分别用NAC、BSO及tBHQ预先处理PC12细胞均能明显降低DM所增加的ROS,分别是DM组的22%、62%、38%.差异均有统计学意义(P<0.05).结论 DM能诱导PC12细胞ROS生成增高,胞内巯基水平和抗氧化功能降低可能是ROS生成增高的影响因素.     

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.     

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.