镁离子对小鼠CCl_4实验性肝损伤的保护作用

目的:探讨镁离子对实验性肝损伤的保护作用。方法:3月龄昆明种小鼠50只,随机分正常对照组、氧化对照组、不同浓度镁保护组,饲养10 d,腹腔注射0.15%CCl4致小鼠肝损伤,24 h取血分离血清,制备肝匀浆,测定血清中ALT、AST及肝匀浆中MDA、SOD、GSH的含量,观察镁离子对肝损伤的保护作用;结果:镁离子能显著降低小鼠血清中ALT和AST活性,以及肝细胞中脂质过氧化物MDA的含量。结论:镁离子能对抑制自由基的生成,促进自由基的清除,对肝损伤有保护作用。     

大蒜对酒精摄入致小鼠亚慢性肝毒性保护作用的探讨

[目的]研究大蒜对亚慢性酒精中毒肝毒性的保护作用及其可能机制。[方法]对60只清洁级ICR雄性小鼠随机分为6组:阴性对照组,酒精肝模型组,酒精 低、中、高剂量大蒜水提取液干预组和维生素E组。干预28天后,处死小鼠,测定相关指标。[结果]亚慢性酒精摄入可致小鼠血清ALT、AST的活力降低,肝匀浆γ-GGT活力受抑;提高肝脏组织MDA含量,抑制GSH-Px酶活力,消耗GSH,并降低SOD酶活力。中高剂量组可部分拮抗AST活力降低,恢复γ-GGT活力水平;抑制肝体系数的升高和肝细胞水肿、脂肪变及坏死;降低肝组织MDA含量,恢复GSH-Px和SOD酶活力,提高GSH含量和增强GST活力。维生素E仅能恢复γ-GGT活力,降低肝组织MDA含量,升高SOD酶活力。[结论]预先给予大蒜对亚慢性酒精摄入致肝毒性有良好拮抗作用,抗氧化作用是大蒜拮抗亚慢性酒精摄入所致肝脏损伤的重要机制,其中GSH解毒体系具有重要意义。     

白桦脂醇对酒精性肝损伤的治疗作用

[目的]观察白桦脂醇对酒精性肝损伤的治疗作用。[方法]将大鼠随机分为6组,正常组、低剂量组、中剂量组、高剂量组、阳性对照组和模型组。采用白酒灌胃的方法建立大鼠酒精性肝病模型,给予白桦脂醇保护。检测血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、碱性磷酸酶（ALP）。高密度脂蛋白（HDL）、低密度脂蛋白（LDL）以及肝匀浆中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—PX）、还原性谷胱甘肽酶（GSH）、谷胱甘肽-S-转移酶（GST）、丙二醛（MDA）水平,同时做肝脏的病理切片观察。[结果]酒精性肝损伤的大鼠血清ALT、AST、ALP活性和LDL含量明显升高。肝匀浆中SOD、GSH-PX、GST活力明显降低;MDA含量明显升高;GSH含量明显降低。白桦脂醇能明显降低模型组大鼠血清中ALT、AST、ALP活性（与模型组比较：P〈0．05）;可明显提高酒精性肝损伤大鼠肝组织中SOD、GSH-PX、GST活性（P〈0．01）和GSH含量（P〈0．05）;同时显著性降低肝组织中MDA含量（P〈0．05）。阳性对照组（益肝灵组）大鼠血清中ALT、AST、ALP活性明显降低和CHO含量明显降低（与模型组比较：P〈0．05）;可明显提高酒精性肝损伤大鼠肝组织中SOD、GSH—PX、GST活性（P〈0．01）和GSH含量（P〈0．05）;同时显著性降低肝组织中MDA含量（P〈0．05）。白桦脂醇还能明显改善由酒精引起的肝组织脂肪样变和坏死。[结论]白桦脂醇能抑制酒精诱导脂质过氧化反应对肝组织的损伤,对酒精性肝损伤有较好的治疗作用。     

镁离子、维生素C对小鼠实验性肝损伤的影响

目的：探讨镁离子、维生素C对昆明种小鼠急性肝损伤的保护作用。方法：昆明种小鼠50只随机分5组，设正常对照组、病理模型组、镁离子保护组，饮水中以MgS04的形式加入镁；维生素C保护组，饲料中加入维生素C；镁离子和维生素C保护组；饲养10d，腹腔注射0．15％0c14致小鼠肝损伤，观察镁离子、维生素C单独应用和联合应用对急性肝损伤的保护作用。结果：镁离子和维生素C能显著降低血清中ALT和AST，以及肝细胞中脂质过氧化物MDA的含量；镁和维生素C合用有协同效应。结论：镁离子和维生素C对实验性肝损伤有保护作用。     

不同给药途径的云芝多糖抗小鼠CCl4肝损伤的实验研究

[目的]研究不同给药途径的CVP抗CCl4肝损伤的作用及机制.[方法]昆明种4月龄雌性小鼠40只,分对照组、模型组、CVP灌胃和饲料中加CVP保护组.饲养8 d,末次灌胃2 h,正常对组腹腔注射调和油溶液,其余各组腹腔注射0.15%CCI4调和油溶液(10 ml/kg体重),18 h后眼球取血分离血清,取出肝脏称重计算肝体指数,制备10%的肝匀浆,测定血清中ALT和AST的活性,检测肝匀浆中SOD、NOS的活性和MDA、GSH和NO的含量.[结果]不同给药途径的CVP保护组与模型组比较,可降低肝体指数(P＜0.05)和MDA的含量(P＜0.001),降低血清中AST活性(P＜0.05),NOS活性及NO的含量(P＜0.01),提高SOD的活性和GSH的含量(P＜0.01).[结论]不同给药途径的CVP对CCl4肝损伤均有保护作用.     

二烯丙基一硫化物对小鼠急性酒精性肝损伤的保护作用

目的研究二烯丙基一硫化物(DAS)对急性酒精性肝损伤的保护作用。方法将40只健康SPF级雄性昆明小鼠随机分为4组,分别为对照组、模型组、DAS干预组和DAS对照组,每组10只。DAS干预组和DAS对照组小鼠经口灌胃给予50 mg/kg的DAS溶液,每天1次,连续7 d;对照组和模型组小鼠给予等体积的玉米油。末次给药2 h后,模型组和DAS干预组小鼠经口灌胃给予5 g/kg乙醇诱导肝损伤,连续3次,每次间隔12 h;对照组和DAS对照组小鼠给予等体积等热量的麦芽糖糊精。测定血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)的活力以及肝组织匀浆中谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPx)活力。结果与模型组比较,对照组、DAS干预组和DAS对照组小鼠血清ALT、AST活力和肝组织匀浆中MDA含量均较低,肝组织匀浆中GSH含量和SOD、GPx、GR活力均较高,差异有统计学意义(P<0.05或P<0.01)。结论 DAS对小鼠急性酒精性肝损伤有保护作用,机制可能与其具有的抗氧化活性有关。     

香菇多糖对小鼠实验性肝损伤保护作用的研究

目的 探讨香菇多糖对小鼠CCL4肝损伤的保护作用.方法 昆明种小鼠分对照组、模型组;香菇多糖分高、中、低保护组,每天按体重50、100和200 mg/kg体重香菇多糖灌胃饲养8d,对照组腹腔注射调和油溶液,其余各组腹腔注射0.15％CCl4调和油溶液,24 h眼球取血分离血清,处死小鼠制备肝匀浆,测血清ALT、AST、计算肝体指数,测定肝匀浆中MDA、SOD、GSH-Px、GSH.结果 香菇多糖各保护组能降低血清ALT、AST活性和肝体指数;增加肝细胞SOD、GSH-Px活性和GSH的含量,降低MDA的含量,与模型组比较,差异有统计学意义(P＜0.05～P＜ 0.01).结论 香菇多糖对CCL4肝损伤有保护作用.     

人参低聚肽对急性酒精性肝损伤大鼠的保护作用

目的 探讨人参低聚肽（GOP）对酒精诱导的大鼠急性肝损伤的保护作用及其可能机制。方法 采用SPF级SD雄性大鼠,随机分为7组,每组10只,包括,1个空白对照组、1个模型对照组、1个乳清蛋白对照组（0.250 0 g/kg）和4个GOP剂量组(0.062 5、0.125 0、0.250 0、0.500 0 g/kg)。连续灌胃30d后,采用体积分数 50%的酒精以 7g/(kg·BW)剂量灌胃造成大鼠急性酒精性肝损伤模型,测定大鼠血清ALT、AST活性和肝脏SOD、GSH、GSH-PX及MDA含量。结果 与模型对照组相比,GOP干预可以显著降低大鼠血清ALT、AST和肝组织MDA(P<0.05或P<0.01)的水平,增加肝组织SOD 、GSH和GSH-PX的活性（P<0.05或P<0.01)。结论 GOP对酒精诱导引起的大鼠急性肝损伤具有保护作用,其机制可能与提高机体抗氧化水平有关。     

林蛙油对老年雌性大鼠脂质过氧化的影响

[目的 ]林蛙油 (oviductusranae)是哈士蟆的干燥输卵管 ,其有效成份为雌酮 ,17β 雌二醇 ,17β 羟甾醇脱氢酶 ,睾酮、孕酮 ,胆甾醇 ,维生素A ,胡萝卜素 ,无机盐钾、钠、镁、钙、铁、锰和硒等。本文观察了林蛙油对老年雌性大白鼠的SOD ,GSH PX,MDA的影响。 [方法 ]样品为吉林干林蛙油 ,黄白色 ,不规则块状 ,有特殊油脂味。设 0 17,0 83和 4 2 5g/kg体重 3个剂量组 ,一个老年鼠对照组和一个青年鼠对照组 ,连续灌胃 2个月。测定血清SOD和GSH PX 含量和肝匀浆MDA值。 [结果 ]可见高剂量组血清SOD和GSH PX 含量升高 ;在高、中剂量组肝匀浆MDA含量降低。 [结论 ]林蛙油可能具有一定的抗脂质过氧化作用     

水溶性辅酶Q10与维生素E协同抗氧化作用研究

[目的]研究水溶性辅酶Q10与维生素E协同对老龄小鼠和D-半乳糖衰老模型小鼠的抗氧化作用。[方法]通过测定给药小鼠血液中或组织中超氧化物歧化酶（SOD）活性和丙二醛（MDA）的含量来研究水溶性辅酶Q10＋维生素E的抗氧化功能。[结果]老龄鼠组：与阴性对照组相比,辅酶Q10＋维生素E组能明显提高小鼠红细胞中SOD活力,MDA活性均不同程度下降;衰老模型组：与空白对照组和模型对照组相比,辅酶Q10＋维生素E组小鼠红细胞及肝脏组织中SOD活性有不同程度升高,MDA含量均有不同程度下降。[结论]辅酶Q10和维生素E具有协同作用,其抗氧化效果优于单独的维生素E。     

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.