阿维菌素原药诱导大鼠肝组织热应激蛋白70基因表达的研究

目的研究阿维菌素原药诱导大鼠肝组织HSP70基因表达的变化,为阿维菌素原药环境污染早期监控及暴露人群的保护提供依据。方法将清洁级Wistar大鼠随机分成3个染毒组和1个对照组,每组12只,雌雄各半,3个染毒组每日经口灌胃不同浓度阿维菌素原药植物油稀释液,最终染毒剂量分别为2.5、1.25、0.625 mg/kg,连续染毒14 d,对照组给予等量花生油。观察大鼠一般状况,测定血清总蛋白(TP),并运用RT-PCR扩增技术观察肝组织HSP70 mRNA表达的变化。结果2.5 mg/kg剂量组雌性大鼠血清TP低于对照组(P<0.05);各染毒组动物肝组织HSP70 mRNA表达呈剂量-效应关系,2.5 mg/kg及1.25 mg/kg剂量组HSP70 mRNA表达明显增加(P<0.05)。结论阿维菌素原药能够敏感地诱导HSP70基因的表达,提示检测HSP70基因表达可作为阿维菌素原药早期监控的指标之一。     

硝酸铅诱导大鼠肝组织及L-02细胞热应激蛋白70基因表达的研究

目的 研究铅诱导热应激蛋白70(HSP70)基因表达的变化.方法 以5、10、20μmol/L硝酸铅染毒胚胎肝细胞株L-02细胞,运用反转录-聚合酶链反应(RT-PCR)扩增技术观察HSP70 mRNA表达的变化.将Wistar大鼠以180、60、20mg/kg3个剂量染毒硝酸铅,并设正常对照组,每组16只,雌雄各半,连续染毒28 d;运用RT-PCR扩增技术观察肝组织HSP70 mRNA表达的变化,并用原子吸收光谱法检测动物肝脏铅含量.结果 在L-02细胞未出现明显细胞毒作用的20μmol/L染铅组HSPT0基因表达明显上调.大鼠肝组织HSP70 mRNA表达与硝酸铅浓度呈剂量-反应关系,180、60 mg/kg染铅组HSP70 mRNA表达明显增加,与阴性对照组比较,差异有统计学意义(P＜0.05);20 mg/kg染铅组与对照组的差异无统计学意义(P＞0.05).各染铅组大鼠肝脏铅含量较对照组明显增加,差异有统计学意义(P＜0.05).结论 硝酸铅能够诱导大鼠肝组织及L-02细胞HSP70 mRNA表达明显增强.     

毒死蜱对小鼠卵巢的毒性及其凋亡基因表达水平的影响

目的研究毒死蜱对小鼠卵巢的生殖毒性及对相关凋亡基因表达水平的影响。方法将40只健康6周龄无生育史清洁级ICR雌性小鼠按体重随机分为4组,分别为阴性对照(玉米油)组和7.5、15.0、30.0 mg/kg毒死蜱染毒组(采用灌胃方式染毒,染毒容量为10 ml/kg,每天1次,每周连续染毒6 d),每组10只。染毒时间为2周。统计各期卵泡构成和颗粒细胞凋亡情况,检测相关凋亡基因的表达水平。结果与阴性对照组比较,15.0、30.0 mg/kg毒死蜱染毒组原始卵泡以及30.0 mg/kg毒死蜱染毒组闭锁卵泡的构成比均较高,15.0、30.0 mg/kg毒死蜱染毒组生长卵泡以及30.0 mg/kg毒死蜱染毒组成熟卵泡的构成比均较低,差异均有统计学意义(P<0.05)。且随着毒死蜱染毒剂量的升高,原始卵泡的构成比呈上升趋势,成熟卵泡的构成比呈下降趋势,生长卵泡的构成比呈先上升后下降的趋势,而闭锁卵泡的构成比呈先下降后上升的趋势。仅30.0 mg/kg毒死蜱染毒组卵巢颗粒细胞凋亡指数显著增高,差异有统计学意义(P<0.05);且随着毒死蜱染毒剂量的升高,小鼠卵巢颗粒细胞凋亡指数呈上升趋势。15.0、30.0 mg/kg毒死蜱染毒组小鼠卵巢组织中mch3 mRNA的表达增高,bcl-2 mRNA的表达下降,差异均有统计学意义(P<0.05)。且随着毒死蜱染毒剂量的升高,小鼠卵巢组织中mch3 mRNA的表达呈上升趋势,bcl-2 mRNA的表达呈下降趋势。结论毒死蜱具有雌性生殖毒性,通过上调mch3的表达和下调bcl-2基因的表达,促进颗粒细胞凋亡,诱导卵泡闭锁,引起卵巢损伤,造成小鼠生育力降低。     

硫酸镉诱导大鼠肝组织及L02细胞热应激蛋白70基因表达的研究

目的 研究重金属镉诱导热应激蛋白70( HSP70)基因表达的变化,探讨以HSP70基因表达作为环境污染及暴露人群监控的敏感性指标.方法 将Wistar大鼠随机分成25.0、8.0及3.0 mg/kg硫酸镉染毒组及正常对照共4组,每组16只,雌雄各半,连续染毒28 d;运用RT-PCR扩增技术观察肝组织HSP70 mR...     

巴豆醛致雄性大鼠神经毒性作用的研究

目的探讨巴豆醛暴露致雄性大鼠神经毒性作用,分析其可能的作用机制。方法于2019年7至10月,将24只SPF级雄性Wistar大鼠随机分为对照组和2.5、4.5、8.5 mg/kg染毒组,每组6只,分别经口给予0.0、2.5、4.5、8.5 mg/kg体重巴豆醛溶液,每周5次,连续染毒90 d。染毒结束后,测量大鼠体重,麻醉解剖取大鼠大脑组织和肝组织。测定大脑组织乙酰胆碱酯酶(AChE)活力及肝组织乙酰胆碱(ACh)水平;检测大脑组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力以及丙二醛(MDA)和还原型谷胱甘肽(GSH)水平;酶联免疫吸附测定(ELISA)法检测大脑组织中白细胞介素6(IL-6)、白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)水平。结果与对照组比较,2.5、4.5、8.5 mg/kg染毒组大鼠大脑组织中AChE活力明显降低,8.5 mg/kg染毒组大鼠肝组织中ACh水平明显升高,差异均有统计学意义(P<0.05);与对照组比较,4.5、8.5 mg/kg染毒组大鼠大脑组织中MDA水平明显升高,GSH水平和SOD、GSH-Px活力明显降低,差异均有统计学意义(P<0.05);与对照组比较,2.5、4.5、8.5 mg/kg染毒组大鼠大脑组织中TNF-α、IL-6水平明显升高,4.5、8.5 mg/kg染毒组IL-1β水平明显升高,差异均有统计学意义(P<0.05)。结论巴豆醛暴露可致大鼠神经系统损伤,可能与氧化平衡状态改变及上调大脑组织炎性因子表达等作用有关。     

亚慢性铝暴露对大鼠大脑皮质中β-位点切割酶1 mRNA和蛋白表达及活力的影响

目的 探讨铝暴露对大鼠大脑皮质中β-位点切割酶1 (beta-site APP cleaving enzyme1,BACE1 )mRNA、蛋白表达及活力的影响.方法 将16只健康清洁级雄性SD大鼠按体重随机分成4组,分别为对照(生理盐水)组和低(0.27 mg/kg)、中(0.54 mg/kg)、高(1.08 mg/kg)剂量麦芽酚铝染毒组,每组4只.采用腹腔注射方式进行染毒,染毒容量为1 ml/kg,连续染毒60 d.测定大鼠大脑皮质中的BACE1 mRNA、蛋白表达及活力.结果 0.54、1.08 mg/kg麦芽酚铝染毒组BACE1 mRNA和蛋白表达及活力均明显高于对照组,差异具有统计学意义(P＜0.05).且随着麦芽酚铝染毒剂量的升高,大鼠皮质BACE1 mRNA和蛋白表达及活力呈上升趋势.结论 铝暴露可导致大鼠大脑皮质BACE1 mRNA、蛋白表达和活力升高.     

低剂量毒死蜱和氯氰菊酯联合染毒对雌性大鼠生殖发育的影响

目的 观察低剂量毒死蜱(氯吡硫磷)和氯氰菊酯联合染毒对雌性大鼠生育功能的影响。 方法 健康Wistar大鼠雌雄按2∶1合笼,将孕鼠分为对照组、毒死蜱组、氯氰菊酯组和联合染毒组等4组,每组8只。按照1 ml/kg量灌胃,毒死蜱组剂量为1.6 mg/kg,氯氰菊酯组剂量为2.5 mg/kg,联合染毒组给药毒死蜱1.6 mg/kg+氯氰菊酯2.5 mg/kg。从孕1~孕8 d染毒,孕19 d,处死孕鼠,记录黄体数和总着床数,活胎的体重和身长,并观察活胎外观是否有畸形。分离胎盘并记录胎盘重量,测定大鼠全血的乙酰胆碱酯酶(AchE)的活力,免疫组织化学检测P450aromA。 结果 孕第19 d,联合染毒组孕鼠体质量与对照组比较明显降低(P<0.05);各组孕鼠黄体数、总着床数、死胎率、胎仔性别比例和胎仔身长与对照组比较差异无统计学意义(P>0.05)。联合染毒组胎盘质量较对照组显著降低(P<0.05)。染毒各组活胎仔体质量较对照组明显降低(P<0.05)。联合染毒组孕鼠全血中AChE活力较对照组显著降低(P<0.05)。单独染毒组胎盘P450aromA蛋白表达与对照组相似,联合染毒组胎盘P450aromA蛋白表达显著高于对照组(P<0.05)。 结论 低剂量毒死蜱和氯氰菊酯联合染毒产生一定的胚胎毒性,造成仔鼠发育迟缓,并引起了孕鼠AchE的下降和胎盘P450aromA蛋白表达的增强。     

锰对大鼠大脑热休克蛋白27、70 mRNA表达的影响

[目的]探讨锰染毒条件下大鼠大脑热休克蛋白27(HSP27)和70(HSP70)的变化规律。[方法]健康2月龄雄性SD大鼠50只,随机分为5组:生理盐水对照组和Mn2+染毒2.5、5.0、10.0、20.0mg/kg组(分别以A、B、C、D和E组表示)。每只大鼠每天腹腔注射染毒0.5mL,连续30d,处死大鼠后采用等离子体原子发射光谱(ICP-AES)测定脑组织锰含量。通过实时荧光定量PCR(QT-PCR)检测大鼠亚慢性锰染毒后脑组织中HSP27和HSP70mRNA的相对表达水平。[结果]不同剂量组脑组织中的锰含量与对照组相比差异具有统计学意义(P<0.01)。与对照组相比,B、C、D、E组HSP27mRNA的相对表达量增加,分别为对照组的2.00、5.51、8.78和6.61倍;HSP70mRNA的相对表达量也增加,分别是对照组的1.68、10.27、22.88和2.20倍。[结论]锰可以调节大鼠脑组织HSP27和HSP70表达的变化。     

3种黄酮类化合物对铝染毒大鼠肝肾抗氧化系统的保护作用

目的探讨黄酮类化合物对铝染毒大鼠肝肾抗氧化系统的保护作用。方法将64只健康SPF级雄性Wistar大鼠按体重随机分为8组,分别为阴性对照组、三氯化铝染毒组和100、200 mg/kg芦丁、葛根素、水飞蓟素拮抗组,每组8只。采用灌胃方式进行染毒,每天1次,其中,阴性对照组连续12周给予1.0 ml/d生理盐水;前4周三氯化铝染毒组和各剂量芦丁、葛根素、水飞蓟素拮抗组分别给予281.40 mg/kg三氯化铝溶液;后8周分别给予1 ml生理盐水及相应剂量的黄酮类化合物。测定大鼠肝、肾组织中的丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、ATP酶(ATPase)活力。结果与阴性对照组相比,三氯化铝染毒组大鼠肝、肾组织中的MDA含量升高,而SOD、GSH-Px活力及Na~+K~+-ATP酶、Mg~(2+)-ATP酶、Ca~(2+)-ATP酶活力均下降,差异均有统计学意义(P0.05)。与三氯化铝染毒组比较,200 mg/kg芦丁拮抗组大鼠肝组织中的SOD活力以及200 mg/kg芦丁、葛根素拮抗组和各剂量水飞蓟素拮抗组大鼠肝组织中的GSH-Px活力均升高,差异均有统计学意义(P0.05);而各剂量芦丁、葛根素、水飞蓟素拮抗组大鼠肝组织中的MDA含量均无明显变化。与三氯化铝染毒组比较,各剂量芦丁、葛根素、水飞蓟素拮抗组大鼠肾组织中的MDA含量均较低,而200mg/kg芦丁拮抗组大鼠肾组织中的SOD、GSH-Px活力升高,差异均有统计学意义(P0.05)。与三氯化铝染毒组比较,200mg/kg芦丁、水飞蓟素拮抗组大鼠肝组织中的Na~+K~+-ATP酶活力及200 mg/kg芦丁、葛根素、水飞蓟素拮抗组大鼠肝组织中的Ca~(2+)-ATP酶活力以及200 mg/kg葛根素、水飞蓟素拮抗组和各剂量芦丁拮抗组大鼠肝组织中的Mg~(2+)-ATP酶活力均较高,差异有统计学意义(P0.05)。与三氯化铝染毒组比较,200 mg/kg芦丁、水飞蓟素拮抗组大鼠肾组织中的Na~+K~+-ATP酶活力及200 mg/kg葛根素、水飞蓟素拮抗组大鼠肾组织中的Ca~(2+)-ATP酶活力以及200 mg/kg芦丁拮抗组和各剂量水飞蓟素拮抗组大鼠肾组织中的Mg~(2+)-ATP酶活力均较高,差异有统计学意义(P0.05)。且随着芦丁、葛根素、水飞蓟素处理剂量的升高,三氯化铝染毒大鼠肝、肾组织中的MDA含量均呈下降趋势,而SOD、GSH-Px活力和Na~+K~+-ATP酶、Mg~(2+)-ATP酶、Ca~(2+)-ATP酶活力均呈上升趋势。结论黄酮类化合物(芦丁、葛根素、水飞蓟素)在一定剂量范围内对铝染毒大鼠肝肾组织抗氧化系统具有保护作用,可以有效地减轻铝造成的肝肾损伤。     

莱菔硫烷激活核转录因子NF-E2相关因子2通路在拮抗汞所致肝脏氧化损伤中的作用

目的探讨莱菔硫烷(sulforaphane,SFN)通过诱导核转录因子NF-E2相关因子2(nuclear factor erthroid 2-related factor 2,Nrf2)通路激活对汞所致肝脏氧化损伤的拮抗作用及其机制。方法将60只健康成年SPF级Wistar大鼠按体重随机分成6组,分别为对照(生理盐水)组,DMSO对照组,0.6、1.2、2.4 mg/kg氯化汞染毒组及SFN预处理(2.4 mg/kg氯化汞+2 mg/kg SFN)组,每组10只,雌雄各半。采用皮下注射SFN溶液,其余各组皮下注射生理盐水,DMSO对照组皮下注射DMSO;2 h后,腹腔注射氯化汞溶液,染毒容量均为5 ml/kg,每日1次,连续染毒3 d。测定血清乳酸脱氢酶(lactate dehydrogenase,LDH)及丙氨酸氨基转移酶(alanine transaminase,ALT)活力和肝细胞ROS水平以及肝组织Nrf2、血红素单加氧酶-1(HO-1)、γ-谷氨酰半胱氨酸合成酶催化亚基(γ-GCSh)的m RNA及蛋白的表达水平。结果与对照组比较,各剂量氯化汞染毒组大鼠血清LDH、ALT活力(除0.6 mg/kg氯化汞染毒组ALT活力外)和肝细胞ROS水平以及1.2 mg/kg氯化汞染毒组大鼠肝组织HO-1 m RNA的表达水平和2.4 mg/kg氯化汞染毒组大鼠肝组织Nrf2、HO-1、γ-GCSh m RNA的表达水平及1.2、2.4 mg/kg氯化汞染毒组大鼠肝组织Nrf2、HO-1、γ-GCSh蛋白的表达水平均升高,差异均有统计学意义(P0.05,P0.01);且随着氯化汞染毒剂量的升高,大鼠血清LDH、ALT活力和肝细胞ROS水平及肝组织Nrf2、HO-1、γ-GCSh蛋白和m RNA的表达水平均呈逐渐上升的趋势。与2.4 mg/kg氯化汞染毒组比较,SFN预处理组大鼠血清LDH、ALT的活力和肝细胞ROS水平均较低,而肝组织Nrf2、HO-1、γ-GCSh蛋白和m RNA的表达水平均较高,差异均有统计学意义(P0.05,P0.01)。结论 SFN可通过诱导Nrf2-ARE通路激活,促使肝细胞Nrf2及其下游抗氧化酶HO-1、γ-GCSh表达,进而清除细胞内过量的ROS,从而拮抗汞所致肝脏氧化应激损伤。     

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.