应用FRTL-5细胞甄别农药亚乙基硫脲、二甲戊乐灵甲状腺素干扰效应

目的　了解亚乙基硫脲 (ETU)、二甲戊乐灵对FRTL 5细胞分泌甲状腺球蛋白的影响。方法　首先用MTT法测这两种化学物的细胞毒性。然后根据细胞毒性结果确定染毒剂量并用放免法测细胞培养液甲状腺球蛋白的浓度。结果　MTT实验中 ,当二甲戊乐灵浓度大于 5ng μl,亚乙基硫脲浓度大于 36 0ng μl时 ,有明显细胞毒性。亚乙基硫脲和二甲戊乐灵在中高剂量均可引起甲状腺球蛋白浓度显著降低。结论　这两种化学物可能干扰甲状腺球蛋白的合成和分泌。     

过氯酸铵对肺成纤维细胞的作用研究

[目的]探讨过氯酸铵(ammoniumperchlorate ,AP)对肺成纤维细胞(fibroblast ,FB)纤维化作用。[方法]原代培养小鼠胚胎肺FB ,稳定传代3次后台盼蓝染色,以细胞成活率>95 %确定0～40 0mg/L作为染毒浓度,以不同浓度的AP(0、5 0、10 0、2 0 0、40 0mg/L)染毒肺FB 48h后,测定各组细胞总蛋白质含量、增殖指标(MTT法测培养细胞D值)及羟脯氨酸(HYP)含量。本试验同时以石英(3 0 0mg/L)对肺FB染毒作为阳性对照。[结果]各AP染毒组肺FB蛋白质含量为5 3 5 9～5 8.69μg/ml,D值为0 .13 6～0 .14 6,HYP含量为0 .610～0 .688μg/ml,各AP染毒组之间比较差异均无显著性。石英组蛋白质含量为63 .19μg/ml,与各AP染毒组比较差异无显著性,但其D值0 .194、HYP含量1.182 μg/ml与各AP染毒组比较差异有显著性(P <0 .0 1)。[结论]肺FB在AP直接染毒作用下,未见肺FB增殖和肺胶原纤维增生等改变。     

应用FRTL-5细胞探索五氯苯酚干扰甲状腺激素作用机制

目的利用FRTL-5细胞,在体外研究五氯苯酚干扰甲状腺激素活性的机制。方法设二甲亚砜溶剂对照组(DMSO);高氯酸钠摄碘阳性对照组;五氯苯酚:0.1μg/ml、0.3μg/ml和0.5μg/ml三个剂量组;五氯苯酚处理FRTL-5细胞24小时,用3H掺入法测其对FRTL-5细胞DNA合成的影响,放免法测其对培养液中甲状腺球蛋白浓度的影响;用五氯苯酚、高氯酸钠处理FRTL-5细胞12和24小时后,用同位素125I测摄碘能力的变化。结果3H掺入法显示五氯苯酚各剂量组对FRTL-5细胞DNA合成无显著影响;放免法显示五氯苯酚0.3μg/ml和0.5μg/ml剂量组显著降低甲状腺球蛋白浓度;五氯苯酚处理FRTL-5细胞12小时后,0.3μg/ml和0.5μg/ml剂量组使FRTL-5细胞摄碘能力显著增强,处理24小时后,FRTL-5细胞摄碘能力无显著改变,但有降低的趋势,高氯酸钠阳性对照组使FRTL-5细胞摄碘能力在12小时和24小时都极显著降低。结论五氯苯酚干扰甲状腺激素作用可能与其使甲状腺球蛋白浓度的改变有关。     

甲状腺素干扰物对甲状腺滤泡细胞分泌甲状腺球蛋白功能的影响

目的了解几种典型甲状腺素干扰物对甲状腺滤泡(FRTL-5)细胞分泌甲状腺球蛋白功能的影响,探讨其干扰甲状腺素水平的细胞学机制及建立甲状腺素干扰物甄别方法的可行性。方法将大鼠FRTL-5细胞体外培养后接种于24孔培养板,每孔细胞数2×105个,待细胞贴壁后分别加入受试物丙硫氧嘧啶、叶枯宁[N,N-甲撑-双(2-氨基-5-巯基-1,3,4-噻二唑)]、磺胺二甲嘧啶和杀草强,各设1组溶剂对照,置CO2孵箱培养48h后,每孔取1ml培养液,用放射免疫法测定甲状腺球蛋白的浓度。结果4个实验组的甲状腺球蛋白浓度与对照组相比均降低,差异有显著性(P<0.05),且可能存在剂量-效应关系。结论降低甲状腺细胞合成或分泌甲状腺球蛋白可能是这4种甲状腺素干扰物的作用机制之一。FRTL-5细胞分泌甲状腺球蛋白的功能是一个相对灵敏的指标,与其他体内体外实验结合可用于甲状腺素干扰物的一阶段甄别(初筛)方法。     

镉对人脐静脉内皮细胞的不良效应

[目的 ]分析镉对人脐静脉内皮细胞毒作用的剂量 效应和时间 效应关系 ,观察镉对内皮细胞分泌功能的影响。 [方法 ]原子吸收法测定细胞内镉浓度反映人脐静脉内皮细胞对镉的摄取 ;噻唑兰 (MTT)和乳酸脱氢酶 (LDH)实验测定镉对内皮细胞的毒作用 ;测定培养液中一氧化氮 (NO)和内皮素 1(ET 1)含量 ,细胞内结构型一氧化氮合酶 (cNOS)活力反映内皮细胞的分泌功能。 [结果 ]随着染毒剂量的增加 ,细胞内镉含量增加。MTT结果表明 <5 μmol/L镉剂量染毒12h可促进内皮细胞增殖 ,剂量 >5 μmol/L和染毒时间 >12h则抑制细胞活力 ,LDH结果与MTT一致。 0 .1～ 10 μmol/L镉染毒 2 4h抑制cNOS活力 ,12h降低培养液中NO浓度。培养液中ET 1浓度在染毒 12h后升高 ,随后下降。 [结论 ]细胞内镉浓度可作为细胞接触镉的内剂量。镉对内皮细胞的直接毒作用与细胞膜损伤有关 ,且存在毒性兴奋效应。镉可能经钙离子通道抑制cNOS活力 ,减少NO合成。镉能促进内皮细胞分泌ET 1但有时限性 ,可能与整体研究中镉升压作用的双相性有关。     

福建水华微囊藻毒素对小鼠免疫细胞影响的体外实验研究

[目的]探讨福建省水华微囊藻毒素对机体免疫细胞的损害.[方法]无菌取小鼠脾细胞和腹腔巨噬细胞,MC-LR染毒剂量均为0、1、5、10 μg/ml,观察MC-LR对小鼠T、B淋巴细胞增殖的影响和MC-LR染毒24、48和72 h对小鼠巨噬细胞增殖的影响.[结果]1、5、10 μg/ml剂量组T淋巴细胞刺激指数(SI)下降;5、10 μg/ml剂量组B淋巴细胞刺激指数下降.染毒48 h,各剂量组腹腔巨噬细胞增殖受到不同程度抑制,其中5、10 μg/ml剂量组抑制增殖明显;染毒72 h,1、5、10 μg/ml剂量组抑制增殖明显,呈现一定的剂量效应关系.[结论]福建省水华微囊藻毒素可以明显抑制小鼠脾T、B淋巴细胞的增殖,损伤特异性免疫功能;还可明显抑制小鼠腹腔巨噬细胞的增殖,损伤非特异性免疫功能.     

乙烯硫脲对FRTL-5细胞甲状腺球蛋白合成分泌及摄碘功能的影响

目的探讨乙烯硫脲(ETU)对FRTL-5细胞的甲状腺球蛋白(TG)合成分泌和摄碘能力的影响。方法用30、150和270μg/ml乙烯硫脲处理FRTL-5细胞后,用MTT法和3H掺入法测乙烯硫脲的细胞毒性;放免法和免疫细胞化学法测乙烯硫脲对TG合成分泌的影响;RT-PCR检测乙烯硫脲对nis基因和tg基因的影响;同位素示踪法检测对细胞摄碘能力的影响。结果30～270μg/ml乙烯硫脲对FRTL-5细胞无显著细胞毒性。150μg/ml和270μg/ml乙烯硫脲显著降低培养液中TG浓度,对胞浆内TG无显著影响;使nis基因转录显著降低,对tg基因无显著影响;150μg/ml和270μg/ml乙烯硫脲显著降低细胞摄碘能力。结论乙烯硫脲可抑制FRTL-5细胞分泌TG,对TG合成无显著影响;乙烯硫脲各剂量组显著降低nis基因转录,但仅在高剂量组显著降低细胞摄碘能力。     

β-胡萝卜素与香烟烟气颗粒物对体外大鼠肺细胞毒性的交互作用

[目的 ]研究 β 胡萝卜素对香烟烟气颗粒物致肺细胞毒性的交互作用。[方法 ]建立大鼠肺Ⅱ型细胞体外培养模型 ,加入 β 胡萝卜素或 /和香烟烟气颗粒物用MTT比色法检测细胞活性。[结果 ] β 胡萝卜素剂量在 0 1～ 0 5 μg/ml时 ,肺细胞活性明显增加 ;剂量在 1 0～ 2 0 μg/ml时 ,肺细胞活性明显降低。β 胡萝卜素在 0 2 μg/ml剂量时 ,可抑制香烟烟气颗粒物毒性 ;而在 0 5～ 2 0 μg/ml剂量范围内可增强香烟烟气颗粒物的细胞毒性作用。[结论 ] β 胡萝卜素在 0 1～2 0 μg/ml剂量范围内对大鼠肺细胞的生长具有先促进后抑制的双重作用。β 胡萝卜素对香烟烟气颗粒物肺细胞毒性存在交互作用 ,低浓度时表现为拮抗作用 ,高浓度时为协同作用。其交互作用可能是在细胞内实现的     

硫酸镍与亚砷酸钠联合致叙利亚地鼠胚胎细胞转化作用的实验研究

目的　探讨砷在镍冶炼工肺癌病因中的作用。方法　采用细胞灶法观察硫酸镍与亚砷酸钠联合致叙利亚地鼠胚胎 (SHE)细胞的形态学转化作用。结果　硫酸镍、亚砷酸钠及硫酸镍与亚砷酸钠联合染毒三个组均有细胞转化灶形成 ,其形成率均呈现剂量依赖关系。刀豆球蛋白A凝集试验进一步验证了细胞转化结果。联合作用分析显示 ,硫酸镍为 2 .5 μg/ml,亚砷酸钠分别为 0 .12 5、0 .2 5 0、0 .5 0 0和 1.0 0 0 μg/ml,两化合物联合作用转化率实测值分别为 1.44 %、2 .34 %、3.30 %和3.94% ,而预期转化率分别为 1.78%、2 .2 2 %、3.38%和 3.37%。说明在等剂量原则下 ,硫酸镍、亚砷酸钠单独染毒的转化细胞灶形成率之和与两化合物同时染毒的转化细胞灶形成率非常接近 ;析因分析未见两者间有交互作用 (P =0 .6 16 )。结论　Ni2 、As3 具有细胞转化活性 ,二者联合呈相加作用。     

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.     

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.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.