牛黄及胆红素对三氯乙烯染毒小鼠脂质过氧化的拮抗作用

目的研究牛黄、胆红素对三氯乙烯(TCE)染毒ICR小鼠所致的脂质过氧化的拮抗作用。方法用TCE灌胃染毒ICR小鼠制造脂质过氧化模型,然后分别以牛黄、胆红素灌胃,测定ICR小鼠肝、肾组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH Px)、过氧化氢酶(CAT)。结果与阴性对照组比,TCE处理组肝、肾组织GSH Px、SOD、CAT活力降低,MDA含量增加,差异均有显著性(P<0.05);牛黄、胆红素染毒与TCE处理组比较,肝、肾组织GSH Px、SOD、CAT活力显著增强(P<0.05),脂质过氧化产物MDA含量减少。结论牛黄和胆红素均能较好地拮抗TCE所引起的ICR小鼠脂质过氧化。     

牛黄及制剂对正己烷致小鼠肝、肾脂质过氧化的保护作用研究

目的探讨牛黄和以其为主药的3个中药制剂对正己烷所致小鼠脂质过氧化性组织损伤的拮抗作用。方法36只CD小鼠分为6组,用牛黄和3个中药制剂对正己烷急性染毒的小鼠进行干预,分别观察小鼠的肝、肾脏器系数,肝、肾组织中丙二醛(MDA)水平及组织病理变化情况。结果正己烷染毒小鼠肝、肾组织中MDA增高并伴有明显的组织病理损伤。采用牛黄和中药制剂进行干预可明显降低肝、肾组织中MDA水平并减轻组织病理损伤程度。结论牛黄及其中药制剂对正己烷诱发肝、肾组织脂质过氧化作用具有一定保护效应。     

正己烷急性染毒对小鼠肝、肾损伤及机理探讨

目的探讨正己烷急性染毒对小鼠肝、肾的损伤及体内氧化应激反应的变化情况。方法分别以10、15和25mg/kg剂量的正己烷一次经口灌胃染毒小鼠,24h后观察小鼠肝、肾脏器系数、血清肝、肾相关生化指标、肝、肾组织总抗氧化能力(TAOC)和丙二醛(MDA)水平及肝、肾组织病理变化情况。结果正己烷急性染毒小鼠血清和肾组织中TAOC降低,MDA明显增高并伴有明显组织病理损伤;10mg/kg组小鼠肝组织TAOC升高,25mg/kg组肝组织TAOC则明显降低。染毒组小鼠血清总胆汁酸水平明显降低;血清TBIL有降低趋势,但与对照组相比差异无统计学意义。染毒组小鼠血清ALT、UA和BUN与对照组相比差异无统计学意义。结论正己烷急性染毒可通过诱导氧化应激反应造成肝、肾组织损伤,血清常规肝、肾损伤生化指标对正己烷急性染毒可能并不很敏感。     

混苯对大鼠血脂和脂质过氧化水平的影响及含晒果茶的拮抗作用

目的　探讨混苯对大鼠血脂和脂质过氧化的影响及复方果茶的拮抗作用。方法　按现场可能接触苯(BZ)、甲苯 (Tol)和二甲苯 (Xyl)的比例范围 ,配制混苯A(每L含BZ 440g、Tol 88g、Xyl 2 2g)和B(每L含BZ 5g、Tol 44g、Xyl 5 0 0g)。用山楂、制首乌、防己、白术、绿茶及亚硒酸钠配制复方果茶。混苯经腹腔注射染毒 ( 1ml/kg ,隔日 1次 ,共 18次 ) ,复方果茶经饮水给予 (每天 2 5ml/kg) ,同时设玉米油溶剂对照组 (方法同混苯组 )。结果　A组血清TC和TG明显高于对照组 (P <0 .0 5 ) ;A 果茶组血清TC和TG均低于A组 ,略高于对照组 ,但差异均无显著性。A和B组血清MDA含量明显升高 ,血清SOD和GSH Px活力均明显降低 (与对照组比较 ,皆P <0 .0 5 ) ;A 果茶组血清MDA浓度、SOD和GSH Px活力与对照组比较 ,差异均无显著意义。A组骨髓MDA含量、SOD和GSH Px活力均明显高于对照组 (P <0 .0 5 ) ;A 果茶组骨髓MDA浓度和GSH Px活力均明显低于A组 (P <0 .0 5 )。结论　混苯可导致大鼠体内脂质过氧化反应增强 ,血清抗氧化酶SOD和GSH Px活力下降 ;主要含苯的混苯还可引起大鼠血脂水平升高、骨髓脂质过氧化反应增强及SOD和GSH Px活力代偿性升高 ;复方果茶可降低混苯升高的血脂水平 ,抑制脂质过氧化作用 ,上调血清抗氧化酶活力     

丙烯酰胺对小鼠抗氧化能力和免疫功能的影响

小鼠经口给予不同剂量 ( 5 0、 10 0、 15 0mg/kg)的丙烯酰胺 (AAM ) ,每周 5次 ,6周后断头取血检测指标。结果显示 ,染毒小鼠体重明显下降 ,血清脂质过氧化代谢产物 (MDA)含量增高 (P <0 0 1) ,超氧化物歧化酶 (SOD)及全血谷胱甘肽氧化酶 (GSH Px)活性于 15 0mg/kg染毒组降低非常明显 (P <0 0 1) ,15 0mg/kg染毒组小鼠血中胶体炭粒清除速度明显降低 ,胸腺相对质量明显增加。说明AAM有抑制机体抗氧化能力和降低机体网状内皮系统吞噬功能的作用     

急性氯化甲基汞染毒大鼠脑某些抗氧化指标的变化

目的 对SD大鼠经腹腔注射氯化甲基汞(MeH必)的急性染毒方式，观察其对大鼠脑组织和血清某些抗氧化指标的变化。方法 用甲基汞对大鼠染毒24h后，断头处死，取血清和脑组织检测谷胱甘肽过氧化物酶(GSH—Px)和超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量。结果 染毒24h后，5．00mg／kg和10．00mg／kg剂量的大鼠脑组织匀浆和血清中的GSH—Px活性和S0D活性下降，MDA含量上升。结论 甲基汞染毒24h后，GSH—Px和SOD活性下降，MDA含量上升，表明这种作用对MeHgCl引起的神经毒性有一定的敏感性。MeHgCl可使脑组织和血清中某些抗氧化指标发生变化。     

沥青烟对小鼠血清及脑组织氧化损伤指标的影响

目的 探讨沥青烟对小鼠血清及脑组织中谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)活力及过氧化氢(H2O2)、丙二醛(MDA)含量的影响.方法 将40只成年雄性小鼠按体重随机分为4组,分别为对照组(0 mg/m3)和低剂量(41 mg/m3,1/4 LD0)、中剂量(82 mg/m3,1/2 LD0)及高剂量(165 mg/m3,LD0)染毒组,每组10只.采用1 m3静式染毒柜行呼吸道吸入染毒,2 h/d,连续8周.测定各组小鼠血清和脑组织中GSH、H2O2、MDA含量及GSH-Px活力.结果 与对照组比较,染毒组小鼠血清和脑组织匀浆中GSH含量和GSH-Px活力显著下降,H2O2 、MDA含量显著升高.结论 沥青烟可致小鼠脑组织细胞发生氧化性损伤,使机体的抗氧化能力降低.     

铅对小鼠睾丸组织脂质过氧化作用及杭白菊对其保护作用的研究

本文通过给雄性小鼠腹腔注射醋酸铅染毒,测定各不同染毒剂量组与空白对照及杭白菊灌胃组中血铅、血浆中VitC和小鼠睾丸组织中T—SOD、GSH—Px活力,MDA含量．以观察铅对小鼠睾丸组织脂质过氧化作用及杭白菊对其保护作用。结果表明：铅染毒组T—SOD活力和GSH—Px活力下降．其中T—SOD活力与铅含量呈负相关（r＝-0．6098,P＜0．01）;杭白菊灌胃组T—SOD和GSH—Px活力上升,与铅染毒组相比,差异显著（P＜0．05）,其中GSH—Px恢复到对照水平。杭白菊灌胃组较染毒组血铅含量下降,血浆中VitC含量上升,差异显著（P＜0．05）。     

桐油对小鼠机体抗氧化能力的影响

[目的 ]实验观察桐油对小鼠机体抗氧化能力的影响。 [方法 ]将 40只BALB/C小鼠分为 4组 ,分别经口染毒桐油 0 ,2 0 0 0 ,40 0 0 ,6 0 0 0mg/kg,1次 /d ,连续 5d。 7d后测定血清超氧化歧化酶 (SOD)、总抗氧化能力及全血谷胱甘肽氧化酶 (GSH Px)的活性。 [结果 ]桐油染毒 4 0 0 0 ,6 0 0 0mg/kg的 2组小鼠 ,SOD、GSH Px活性和总抗氧化能力均低于对照组 (P <0 0 1 )。 [结论 ]口服 4 0 0 0mg/kg以上桐油有抑制小鼠机体抗氧化能力的作用     

维生素E对二甲基甲酰胺致小鼠急性肝损伤的拮抗作用

目的 探讨维生素E( Vitamin E,VE)对二甲基甲酰胺(N,N-dimethylformamide,DMF)致急性肝损伤的拮抗作用.方法 将50只健康SPF级雄性昆明小鼠随机分为5组,分别为正常对照组、VE( 10 mg/kg)对照组、DMF中毒模型组及低(5 mg/kg)、高(10 mg/kg)剂量VE保护组,每组10只.VE对照组和低、高剂量VE保护组采用灌胃方式染毒VE溶液,正常对照组和DMF中毒模型组分别染毒等体积玉米油,每天1次,连续5d;最后1次染毒VE后0.5 h,DMF中毒模型组及各剂量VE保护组一次性灌胃染毒2g/kg的DMF溶液,同时,正常对照组和VE对照组给等体积蒸馏水.检测小鼠血清丙氨酸氨基转氨酶(ALT)、天冬氨酸氨基转氨酶(AST)和黄嘌呤氧化酶(XOD)活力,肝脏匀浆中谷胱甘肽(GSH)和脂质过氧化产物丙二醛(MDA)的含量.结果 与DMF中毒模型组比较,VE保护组小鼠血清ALT、AST 、XOD活力显著降低(P＜0.05),肝脏GSH含量明显升高(P＜0.05),MDA含量显著下降(P＜0.05).结论 VE对DMF引起的小鼠肝损伤具有拮抗作用.     

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.