硫化氢急性中毒大鼠肺组织氧化应激和Nrf2基因表达及乌司他丁的影响

目的 研究硫化氢急性中毒大鼠肺组织氧化应激水平及核转录因子NF-E2相关因子2(nuclear factor E2-related factor 2,Nrf2)基因表达的变化及乌司他丁(ulinastatin,UTI)的影响.方法 将96只清洁级SD大鼠随机分为正常对照组(8只)、UTI对照组(8只)、硫化氢染毒组(40只)、UTI干预组(40只).正常对照组和UTI对照组大鼠于染毒柜内吸人与硫化氢同样流量的空气1h,UTI对照组大鼠立即腹腔注射UTI(10万U/kg),2h后处死.硫化氢染毒组和UTI干预组大鼠在染毒柜内吸入硫化氢(浓度为283.515 mg/m3)1h,UTI干预组大鼠立即腹腔注射UTI(10万U/kg),两组大鼠分别于2、6、12、24、48 h处死,每组8只.检测肺组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化氢酶(GSH-Px)活力和谷胱甘肽(GSH)含量及Nrf2 mRNA的表达,观察肺组织病理学改变并行肺损伤评分.结果 与正常对照组比较,2、6、12 h硫化氢染毒组大鼠肺组织中SOD、CAT活力和GSH含量及2、6、12、24h GSH-Px活力明显降低,差异有统计学意义(P＜0.01或P＜0.05);2、6、12、24h硫化氢染毒组大鼠肺组织中MDA含量明显升高,差异有统计学意义(P＜0.01).与相应时间点硫化氢染毒组比较,UTI干预组6、12h时GSH-Px活力,2、6、12h时CAT活力,2、6、12、24h时GSH含量及2、6、12、24、48 h时SOD活力明显升高,差异均有统计学意义(P＜0.01或P＜0.05);UTI干预组2、6、12h时MDA含量明显低于相应时间点硫化氧染毒组,差异有统计学意义(P＜0.01).染毒后2、6、12、24 h,硫化氢染毒组肺组织中Nrf2 mRNA表达(0.314±0.011、0.269±0.010、0.246±0.011、0.221士0.018)明显高于正常对照组(0.149±0.012),差异有统计学意义(P＜0.01);与相应时间点硫化氢染毒组比较,2、6、12、24、48 h UTI干预组的Nrf2 mRNA表达(0.383:±-0.017、0.377±-0.014、0.425±0.017、0.407±0.011、0.381±0.010)明显升高,差异均有统计学意义(P＜0.01).光学显微镜下观察可见,硫化氢染毒组染毒后24h大鼠肺组织损害明显,UTI干预组大鼠肺损伤较硫化氢染毒组有所减轻.UTI干预组12、24、48 h时肺损伤评分明显低于相应时间点硫化氢染毒组,差异有统计学意义(P＜0.01).结论 氧化应激和Nrf2活化是参与硫化氢中毒急性肺损伤的重要因素,UTI能抑制氧自由基产生,纠正氧化还原失衡,上调Nrf2 mRNA表达水平,减轻氧化应激损伤,对肺组织损伤有保护作用.     

缺血后适应对肢体缺血-再灌注后肺损伤的影响

目的 探讨缺血后适应对肢体缺血再灌注后肺损伤的影响及作用机制. 方法 将实验动物随机分为三组:对照组、缺血再灌注组(IR)和缺血后适应组(IPC).检测各组血清及肺组织中丙二醛(MDA)及超氧化物岐化酶(SOD)的含量变化,并检测肺组织中髓过氧化物酶(MPO)的活性.HE染色光镜下观察肺组织病理形态学改变. 结果 与对照组比较,IR组和IPC组动物血清MDA含量均明显升高(P＜0.01),而SOD含量则明显降低(P＜0.01).与IR组比较,IPC组血清MDA含量明显下降(P＜0.01),SOD含量明显升高(P＜0.01).与对照组比较,IR组和IPC组动物肺组织中MDA含量均明显升高(P＜0.01),而SOD含量则明显降低(P＜0.01);IPC组与IR组之间比较,IPC组肺组织中MDA含量较IR组明显下降(P＜0.01),而SOD含量较IR组明显升高(P＜0.01).IR组动物肺组织中MPO活性明显高于对照组和IPC组(P＜0.01),IPC组肺组织中MPO活性略高于对照组,但差异无统计学意义.光镜下IR组表现为肺间质水肿和中度炎症等肺损伤病理改变,而IPC组肺损伤病理改变较轻. 结论 IPC可减轻大鼠LIR后的肺损伤,其机制与抑制氧化应激、PMN的活化及炎症反应的扩散有关.     

乙苯染毒对大鼠肺的氧化应激损伤及病理的影响

目的 观察亚慢性吸人乙苯染毒对大鼠肺组织氧化应激损伤和组织病理结构、细胞超微结构的影响.方法 将40只健康3周龄SPF级SD雄性大鼠随机分为4组,分别为对照组(新鲜空气)和低(433.5 mg/m3)、中(4335 mg/m3)和高(6500 mg/m3)剂量乙苯染毒组,每组10只.每天染毒6h,每周5d,连续染毒13周.检测肺组织中还原型谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力和丙二醛(MDA)含量并进行超微结构和病理学观察.结果 乙苯染毒大鼠肺组织出现肺泡壁毛细血管充血,肺泡间纤维组织增生、增厚等病理变化,超微结构的变化主要表现为肺组织大部分血管内皮细胞肿胀,胞质厚度增加.与对照组相比,各染毒组大鼠肺组织MDA含量均明显升高,差异有统计学意义(P＜0.05).中剂量组和高剂量组大鼠肺组织GSH和GSH-Px含量均明显低于对照组和低剂量组,差异有统计学意义(P＜0.05).与对照组相比,各剂量组大鼠肺组织SOD和CAT活力呈先升高后降低趋势;与低剂量组比较,中剂量组和高剂量组大鼠肺组织SOD活力和CAT含量均明显降低,差异有统计学意义(P均＜0.05).结论 亚慢性吸入乙苯染毒可诱导大鼠肺组织氧化应激损伤及组织病理结构、组织细胞超微结构的改变.     

氧化应激及核因子-κB在百草枯致大鼠肺损伤中的变化

目的 观察急性百草枯(PQ)中毒大鼠氧化应激及肺组织核因子-κB(NF-κB)的变化,探讨四氢吡咯二硫代氨基甲酸酯(PDTC)的治疗机制.方法 SD大鼠144只随机分为对照组6只、PDTC对照组36只、pQ染毒组56只、PDTC治疗组46只.染毒组和治疗组予生理盐水稀释PQ 80mg/kg一次性灌胃后2 h,治疗组给予PDTC 100 mg/kg一次性腹腔注射,染毒组予等量生理盐水腹腔注射;对照组和PDTC对照组于生理盐水1 ml/kg灌胃后2 h,PDTC对照组予PDTC 100 mg/kg一次性腹腔注射,对照组予等量生理盐水腹腔注射.不同处理后1、3、7、14、25、56 d观察大鼠肺组织病理改变;测定血清中丙二醛(MDA)含量及谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、髓过氧化物酶(MPO)活力;测定肺组织中羟脯氨酸(Hyp)含量及NF-κB p65的表达.结果 与对照组比较,染毒组血清中MDA含量和MPO活力升高,GSH-Px、CAT、SOD活力降低,相应时点差异有统计学意义(P<0.05或P<0.01);肺组织NF-κB活性在1、3、7、14 d明显升高,肺组织Hyp含量在14、28、56d明显升高,差异均有统计学意义(P<0.01).PDTC治疗组血清中MDA含量降低,GSH-Px、CAT、SOD活力升高,与染毒组比较,相应时点差异均有统计学意义(P<0.05或P<0.01),在14 dMPO活力为(119.56±21.23)U/L,明显低于染毒组,差异有统计学意义(P<0.05);与染毒组比较,治疗组在1、3、7 d肺组织中NF-κB活性明显降低,差异有统计学意义(P<0.05或P<0.01);治疗组肺组织中Hyp含量在28、56d分别为(0.89±0.05)、(0.93±0.13)μg/mg,明显低于染毒组,差异有统计学意义(P<0.01);病理检查结果显示,治疗组肺组织炎症及纤维化程度均较轻.结论 氧化应激及NF-κB活化是参与PQ致肺损伤的重要机制;PDTC能纠正氧化还原失衡,抑制NF-κB活化,减轻PQ中毒大鼠的肺损伤.     

亚慢性染毒2,3,7,8-四氯二苯并二噁英(TCDD)对大鼠血清中氧化应激指标的影响

目的 研究2,3,7,8-四氯二苯并二(噁)英(2,3,7,8-tetrachlorodibenzo-p-dioxin,TCDD)对大鼠血清中氧化应激指标的影响.方法 清洁级Wistar雄性大鼠32只,体重(100±10)g,随机分成4组,连续经口染毒TCDD 90 d,剂量分别为2.5、25、250 ng/kg,对照组给予二甲基亚砜(DMSO),测定SOD、CuZn-SOD、Mn-SOD、GSH-Px、GST活性及MDA的含量.结果 TCDD染毒90 d后,与对照组相比,各染毒组雄性大鼠血清中MDA含量明显增高(P＜0.05);各染毒组总SOD、CuZn-SOD、MnSOD、GSH-Px活力均有所下降,其中除CuZn-SOD外,与对照组相比差异均有统计学意义(P＜0.05).同时各染毒组GST活力显著增加,且各组间差异有统计学意义(P＜0.05).结论 亚慢性染毒引起MDA含量增加,大鼠血清中抗氧化指标出现异常改变,提示体内出现氧化与抗氧化系统失衡.     

金属硫蛋白对镍铬联合染毒小鼠肝脏损伤的拮抗作用

目的研究硫酸镍+重铬酸钾联合染毒对小鼠肝脏损伤的影响及金属硫蛋白(MT)的拮抗作用。方法将50只健康SPF级昆明小鼠按体重随机分为5组,分别为溶剂对照组(生理盐水)、镍铬(1.0 mg/kg硫酸镍+0.5 mg/kg重铬酸钾)联合染毒组和低、中、高剂量MT保护(1.0 mg/kg硫酸镍+0.5 mg/kg重铬酸+5.0、10.0、20.0 mg/kg MT)组,每组10只,雌雄各半。采取灌胃方式进行染毒,染毒容量为10 ml/kg,每天1次,连续染毒21 d。检测小鼠丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、γ-谷氨酰转肽酶(GGT)活力及肝组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)、谷胱甘肽(GSH)含量。结果与溶剂对照组比较,镍铬联合染毒组小鼠血清AST、ALT、GGT的活力均增高,差异均有统计学意义(P0.05)。各剂量MT保护组小鼠血清AST、ALT、GGT的活力均低于镍铬联合染毒组,差异均有统计学意义(P0.05);且随着MT染毒剂量的升高,MT保护组小鼠血清AST、ALT、GGT的活性均呈下降趋势。与溶剂对照组比较,镍铬联合染毒组小鼠肝组织SOD、GSH-Px活力和GSH含量均下降,而MDA含量升高,差异均有统计学意义(P0.05)。与镍铬联合染毒组比较,各剂量MT保护组小鼠肝组织SOD、GSH-Px活力和GSH含量均升高,而MDA含量均降低,差异均有统计学意义(P0.05),且随着MT染毒剂量的升高,MT保护组小鼠肝组织SOD、GSH-Px活力和GSH含量均呈上升趋势,而MDA含量呈下降趋势。结论 MT对镍铬联合染毒所致小鼠肝脏损伤有较好的拮抗作用,其作用机制可能与MT抗氧化作用有关。     

三氯乙烯对大鼠视网膜的损伤及诱导型一氧化氮合酶的影响

目的探讨三氯乙烯(trichloroethylene,TCE)对大鼠视网膜组织的脂质过氧化损伤效应及诱导型一氧化氮合酶(iNOS)表达的影响。方法将32只大鼠随机分为对照组和500、1 000、2 000mg/kg TCE3个剂量染毒组,测定视网膜组织中超氧化物歧化酶(SOD)活力、丙二醛(MDA)、一氧化氮(NO)的含量,光学显微镜下观察视网膜形态学变化,免疫组织化学法测定iNOS的表达。结果与对照组比较,TCE染毒1 000、2 000mg/kg组大鼠视网膜组织中SOD活力均降低(P0.01),TCE染毒500、1 000、2 000mg/kg组大鼠视网膜组织中MDA含量均升高(P0.05或P0.01);TCE染毒的3个剂量组中,大鼠视网膜组织中NO含量均高于对照组(P0.01)。TCE染毒组大鼠视网膜组织的内核层、外核层、节细胞层出现细胞核变大、水肿、空泡等变化。TCE染毒1 000、2 000mg/kg组大鼠视网膜组织中iNOS活力高于对照组(P0.05)。结论 TCE能激活视网膜组织iNOS表达,产生过量的NO可损伤视网膜细胞;视网膜脂质过氧化作用增强也是TCE所致视网膜损害的机制之一。     

氟和砷联合染毒对大鼠在新环境中探究行为的影响及机制

目的 探讨氟、砷单独及其联合染毒对大鼠在新环境中的探究行为的影响及机制.方法 将96只健康初断乳SPF级SD大鼠随机分为对照(蒸馏水)组和NaF(120 mg/L)染毒组、亚砷酸钠(70 mg/L)染毒组及NaF(120 mg/L)+亚砷酸钠(70 mg/L)染毒组,每组24只,雌雄各半.采用饮水方式连续染毒3个月.采用旷场试验测试大鼠在新环境中的探究行为,检测大鼠血清和海马组织匀浆中总抗氧化能力(T-AOC)水平和丙二醛(MDA)、一氧化氮(NO)含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和一氧化氮合酶(NOS)活力.结果 NaF+亚砷酸钠染毒组大鼠旷场试验总得分低于对照组、NaF和亚砷酸钠染毒组(P＜0.01).NaF、亚砷酸钠和NaF+亚砷酸钠染毒组中央格停留时间均长于对照组(P＜0.01).与对照组比较,NaF、亚砷酸钠和NaF+亚砷酸钠染毒组大鼠血清T-AOC水平及亚砷酸钠染毒组和NaF+亚砷酸钠染毒组血清SOD、GSH-Px活力降低,MDA含量升高(P＜0.05,P＜0.01).与NaF染毒组比较,亚砷酸钠和NaF+亚砷酸钠染毒组大鼠血清中T-AOC水平和GSH-Px活力降低(P＜0.05,P＜0.01).与对照组比较,NaF、亚砷酸钠和NaF+亚砷酸钠染毒组大鼠海马组织匀浆中T-AOC水平均降低(P＜0.01).与亚砷酸钠染毒组比较,对照组、NaF染毒组和NaF+亚砷酸钠染毒组大鼠海马组织匀浆中GSH-Px的活力均较高(P＜0.01).与NaF+亚砷酸钠染毒组比较,NaF、亚砷酸钠染毒组和对照组大鼠海马组织匀浆中MDA含量均较低(P＜0.01).与对照组比较,NaF和NaF+亚砷酸钠染毒组大鼠血清NO含量以及NaF、亚砷酸钠和NaF+亚砷酸钠染毒组大鼠血清中NOS活力及海马组织中NO含量、NOS活力均下降(P＜0.05,P＜0.01).结论 氟、砷及其联合作用可损害大鼠在新环境中的探究行为,其机制可能与海马组织氧化损伤及NO含量和NOS活力降低有关.     

p,p'-DDE对青春前期大鼠睾丸组织氧化应激及凋亡的影响

目的 研究p,p'-DDE对青春前期大鼠睾丸组织氧化应激及凋亡的影响.方法 将健康清洁级22日龄雄性SD大鼠25只按体重随机分为5组,分别为对照组(玉米油)、低(20 ms/kg)、中(60 mg/kg)、高(100 mg/kg)剂量P,p'-DDE染毒组和VitE干预组(100mg/kg p,p'-DDE+100mg/kg Vit E),每组5只.采用腹腔注射方式进行染毒,注射容积为10ml/kg,每隔1 d染毒1次,共10 d.染毒结束后,处死动物,取睾丸称重,并计算睾丸脏器系数;将睾丸制备组织切片和组织匀浆,分光光度计法测定大鼠睾丸组织超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量和谷胱甘肽过氧化物酶(GSH-Px)活力,采用TUNEL法检测睾丸组织的细胞凋亡情况.结果 各组动物染毒前体重及染毒期间体重变化无差异.大鼠睾丸重量及其脏器系数间比较,差异无统计学意义(P＞0.05).与对照组比较,高、中、低剂量p,p'-DDE染毒组SOD活力降低,中、高剂量p,p'-DDE染毒组MDA含量升高,高剂量p,p'-DDE染毒组GSH-Px活力下降,差异均有统计学意义(P＜0.05).与高剂量p,p'-DDE染毒组比较,Vit E干预组SOD活力升高,差异有统计学意义(P＜0.05).Vit E干预组和高剂量p,p'-DDE染毒组MDA含量和GSH-Px活力间比较,差异无统计学意义(P＞0.05).高、中、低剂量p,p'-DDE染毒组和对照组均有睾丸细胞凋亡情况发生,对照组中凋亡细胞稀少;随着p,p'-DDE染毒剂量的升高,凋亡细胞数也逐渐增多,以精原细胞和精母细胞为主,伴有支持细胞.与对照组比较,高、中、低剂量P,p'-DDE染毒组的细胞凋亡指数均升高,差异有统计学意义(P＜0.05);Vit E干预组的细胞凋亡指数低于高剂量p,p'-DDE染毒组,差异有统计学意义(P＜0.05).结论 p,p'-DDE可通过引发睾丸组织氧化应激而诱导细胞凋亡.     

光气染毒造成小鼠肺脏的氧化损伤

目的　研究小鼠光气染毒后不同时间对肺脏的氧化损伤作用。方法　 4 0只雄性小鼠 ,随机分为 4组。正常对照组小鼠以空气为对照 ,染毒组小鼠给予 11.9mg/L剂量的光气 ,时间为5min ,分别染毒后 2h、4h、8h ,测定各组小鼠肺脏的湿干比和肺匀浆液的丙二醛 (MDA)含量、总超氧化物歧化酶 (T SOD)活力、还原型谷胱甘肽 (GSH)含量。结果　随着光气染毒时间的增加 ,小鼠肺脏的湿干比显著增加 (P <0 .0 5 ) ;染毒后 4h ,肺组织MDA含量和T SOD活力显著升高(P <0 .0 5 ) ,GSH含量在染毒后 2h显著降低 (P <0 .0 5 )。结论　光气染毒可引起小鼠肺水肿和肺脏氧化损伤。     

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.