低剂量西维因和氰戊菊酯农药联合染毒对大鼠子宫及机体氧化应激的影响

目的探讨低剂量西维因和氰戊菊酯联合染毒对雌性大鼠子宫系统和机体氧化应激的影响。方法将40只清洁级成年雌性SD大鼠按2×2析因设计随机分为4组,分别为阴性对照(玉米油)组、西维因单独染毒组(1/50LD50,11.2 mg/kg)、氰戊菊酯单独染毒组(1/50 LD50,9.02 mg/kg)和西维因(11.2 mg/kg)+氰戊菊酯(9.02 mg/kg)联合染毒组,每组10只。采用经口灌胃方式进行染毒,每天1次,每周6 d,连续染毒8周。末次染毒24 h后,测量大鼠体重和子宫重量,并计算子宫系数;测定血清中超氧化物歧化酶(SOD)、谷胱甘肽S转移酶(GST)活力和还原性谷胱甘肽(GSH)、丙二醛(MDA)含量以及子宫一氧化氮合成酶(NOS)活力。结果西维因和氰戊菊酯联合染毒对雌性大鼠体重、血清中GST水平均无交互作用(P>0.05);对大鼠子宫系数、血清中MDA含量均存在拮抗作用(P<0.05);对血清中SOD活力、GSH含量及子宫NOS活力存在协同作用(P<0.05,P<0.01)。结论西维因和氰戊菊酯联合染毒对大鼠子宫系统存在联合毒性作用,可能是通过破坏氧化-抗氧化系统的平衡和影响子宫组织中NOS的活力等导致子宫功能的降低。     

低剂量西维因与氰戊菊酯联合染毒对雌性大鼠卵巢细胞凋亡的影响

目的观察西维因与氰戊菊酯联合染毒对雌性大鼠卵巢细胞凋亡的影响。方法将40只健康成年清洁级雌性SD大鼠按2×2析因设计随机分为4组,分别为阴性对照(玉米油)组、西维因(1/50 LD50,11.2 mg/kg)单独染毒组、氰戊菊酯(1/50 LD50,9.02 mg/kg)单独染毒组和西维因(11.2 mg/kg)+氰戊菊酯(9.02 mg/kg)联合染毒组,每组10只。采用经口灌胃方式进行染毒,每天1次,连续染毒8周。检测卵巢颗粒细胞的凋亡情况以及大鼠血清中雌性激素孕酮(P)、雌二醇(E2)、促卵泡激素(FSH)、黄体生成素(LH)含量,并统计卵巢组织中各级卵泡数目构成的变化。结果西维因和氰戊菊酯联合染毒对大鼠卵巢系数和卵巢细胞早期凋亡率均呈现拮抗作用(P<0.05,P<0.01),对血清中E2水平和卵巢组织中闭锁卵泡构成比呈现协同作用(P<0.05)。结论西维因和氰戊菊酯联合染毒可影响大鼠下丘脑-垂体-卵巢轴系统的调节,从而抑制卵巢分泌E2,影响卵巢的发育和分泌激素的功能,促进大鼠卵巢细胞凋亡,引起大鼠卵巢损伤。     

西维因与氰戊菊酯联合染毒对雄性大鼠睾丸细胞凋亡的影响

目的 观察西维因与氰戊菊酯联合染毒对雄性大鼠睾丸细胞凋亡的影响.方法 选择健康成年清洁级雄性SD大鼠40只,按2×2析因设计随机分为4组,分别为阴性对照组(玉米油)、西维因(1/50 LD50,11.2 mg/kg)单独染毒组、氰戊菊酯(1/50 LD5o,9.02mg/kg)单独染毒组和西维因(11.2mg/kg)+...     

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。     

褪黑素对饮水氟染毒大鼠脑组织氧化应激的影响

目的研究不同浓度饮水氟染毒对大鼠脑氧化应激状态的影响及褪黑素(MEL)的干预作用。方法将清洁级初断乳Wistar大鼠34只随机分为5组,分别为对照组(蒸馏水,8只),60、120mg/L氟单独染毒组(各7只),60mg/L氟+5mg/kg褪黑素联合染毒组和120mg/L氟+5mg/kg褪黑素联合染毒组(各6只)。各组大鼠饮用相应浓度的氟化钠溶液;从第7周开始腹腔注射褪黑素溶液,连续染毒10周。染毒结束后,取脑组织测定氟含量和谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平以及单纯氟染毒组大鼠血清褪黑素水平。结果与对照组比较,120mg/L氟单独染毒组以及60mg/L氟+5mg/kg褪黑素联合染毒组和120mg/L氟+5mg/kg褪黑素联合染毒组大鼠脑组织中氟含量均较高,差异有统计学意义(P0.01)。氟单独染毒各组之间比较,GSH、SOD、MDA含量差异无统计学意义。与相同浓度氟单纯染毒组比较,60mg/L氟+5mg/kgMEL联合染毒组大鼠脑组织中GSH含量和SOD活力均较高,但差异无统计学意义;120mg/L氟+5mg/kgMEL联合染毒组大鼠脑组织中GSH含量较高,SOD活力较低,差异均无统计学意义。各组大鼠脑组织中MDA含量间比较,差异无统计学意义。与对照组比较,60mg/L氟单独染毒组大鼠脑组织中褪黑素浓度略有升高,120mg/L氟单独染毒组大鼠脑组织中褪黑素浓度有下降趋势,但差异均无统计学意义(P0.05)。结论氟能透过血脑屏障在脑中蓄积,产生一定程度的氧化损伤,小剂量的褪黑素干预未能见到明显的抗氧化作用。     

三氧化二砷染毒小鼠肝脏中砷甲基化水平与肝脏氧化应激的关系

目的探讨三氧化二砷(As2O3)染毒小鼠肝脏组织中砷甲基化水平的变化及其与肝脏氧化应激关系,为揭示砷甲基化水平在砷毒性机制中的作用提供依据。方法将40只昆明种小鼠随机分为对照组(0.9%生理盐水)、As2O3低中高剂量组(1.0、2.0和4.0 mg/kg)组,连续灌胃5周;采用高效液相色谱与原子荧光联用技术(HPLC-HGAFS)测定肝脏组织中三价无机砷(As3+)、五价无机砷(As5+)、一甲基胂(MMA)、二甲基胂(DMA)含量及构成比(%),计算砷一甲基化指数(PMI)、二甲基化指数(SMI);利用试剂盒测定丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)。结果随着As2O3剂量增加,小鼠肝脏组织中各形态砷代谢产物含量增加(P0.001),砷甲基化水平(i As%、MMA%、DMA%、PMI、SMI)提高(P0.001);小鼠肝脏MDA显著高于对照组(P0.001),GSH、SOD、T-AOC显著低于对照组(P0.001);1 mg/kg染毒剂量时,PMI与T-AOC呈负相关(P0.05),SMI与GSH、SOD呈负相关(P0.05);在2 mg/kg染毒剂量时,PMI、SMI与MDA呈正相关(P0.05)而与GSH、SOD呈负相关(P0.05);在4 mg/kg染毒剂量时,PMI与MDA呈正相关(P0.05),PMI、SMI与GSH、SOD呈负相关(P0.05)。结论随着砷染毒剂量的增加,小鼠肝脏组织中各种形态砷含量增多,砷甲基化水平提高,进而导致小鼠肝脏氧化损伤严重。     

丙烯腈对大鼠睾丸抗氧化酶活力和脂质过氧化水平的影响

目的　探讨丙烯腈(ACN)的雄性生殖毒性机制。方法　健康雄性SD大鼠分别以0、7.5、15.0、30.0 mg/kg剂量腹腔注射ACN染毒,测定其睾丸谷胱甘肽(GSH)、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)、谷胱甘肽S 转移酶(GST)活力。结果　ACN染毒4周后,15.0、30.0 mg/kg组大鼠睾丸GSH含量[(7.44±0.96)、(6.95±0.77)mg/g pro]增加,30.0 mg/k组大鼠GSH Px活力[(70.89±4.01)U/mg pro]升高,与对照组的差异均有统计学意义(P<0.05,P<0.01)。ACN染毒8周后,30.0 mg/kg组大鼠睾丸GSH含量[(2.50±0.94)mg/g pro]降低,15.0、30.0mg/kg组大鼠SOD活力[(102.08±16.08)、(113.30±17.20)NU/mg pro]升高,与对照组的差异均有统计学意义(P<0.01)。ACN染毒13周后,15.0、30.0 mg/kg组大鼠睾丸GSH含量降低,30.0 mg/kg组GST活力下降,各染毒组GSH Px活力均低于对照组,30.0 mg/kg组MDA含量[(0.68±0.16)nmol/mgpro]高于对照组[(0.38±0.12)nmol/mg pro],差异均有统计学意义(P<0.01)。停止染毒后2周,大鼠睾丸GSH水平恢复;30.0 mg/kg组大鼠睾丸MDA含量下降,但仍高于对照组,GSH Px活力仍低于对照组,差异均有统计学意义(P<0.05)。结论　ACN能通过破坏氧化-抗氧化体系的平衡,诱导雄性大鼠睾丸脂质过氧化损伤。     

葡萄籽原花青素对NaF致雄性小鼠肝脏氧化损伤的拮抗作用

[目的]观察葡萄籽原花青素(GSPE)对氟化钠(NaF)致雄性小鼠肝脏组织氧化损伤的拮抗作用. [方法]将40只健康性成熟昆明种雄性小鼠随机分为4组:对照组(0mg/kg)、NaF组(20 mg/kg)、GSPE组(200 mg/kg)及NaF+GSPE组[NaF(20 mg/kg)+GSPE(200 mg/kg)],每组10只动物.灌胃染毒,每天1次,连续染毒5周.颈椎脱臼处死,采集肝脏组织样本,计算肝脏脏器系数,检测肝脏组织中谷丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)和超氧化物歧化酶(SOD)活性,谷胱甘肽(GSH)和丙二醛(MDA)含量以及总抗氧化能力(T-AOC)水平. [结果]各组肝脏脏器系数组间比较,差异有统计学意义(P＜0.05); NaF组高于对照组(P＜0.05),(NaF+GSPE)组低于NaF组(P＜0.05).各组AST、ALT含量组间比较,差异有统计学意义(均P＜0.05);NaF组和(NaF+GSPE)组高于对照组(P＜0.05),GSPE组和(NaF+GSPE)组低于NaF组(P＜0.05).各组GSH、SOD、MDA和T-AOC含量组间比较,差异有统计学意义(均P＜0.05);与对照组相比,NaF组和(NaF+GSPE)组小鼠肝脏中GSH、SOD和T-AOC含量较低(P＜0.05),MDA含量较高(P＜0.05);与NaF组相比,GSPE组和(NaF+GSPE)组GSH、SOD和T-AOC含量较高(P＜0.05),MDA含量较低(P＜0.05).析因分析显示:NaF与GSPE对AST、ALT、SOD活力、MDA含量,T-AOC水平存在拮抗作用. [结论]GSPE对NaF致雄性小鼠肝脏氧化损伤具有拮抗作用.     

茶多酚对甲醛染毒大鼠肺损伤的保护作用

[目的]探讨茶多酚对甲醛染毒大鼠肺损伤的保护作用。[方法]30只3月龄,体重(200±20)g的SPF级SD大鼠,随机分为空白对照组、模型组、茶多酚组。将除正常对照组外的其余两组动物暴露于气态甲醛(10mg/m3)中3个月,每天4h,茶多酚组给予茶多酚水溶液200mg/kg.d-1灌胃。检测肺组织超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽(GSH)及肺组织形态学变化。[结果]模型组大鼠肺组织SOD活性及GSH含量明显低于正常对照组(P﹤0.01),MDA含量明显高于正常对照组(P﹤0.01);茶多酚组大鼠肺组织SOD活性及GSH含量高于模型组(P﹤0.05),MDA含量低于模型组(P﹤0.05)。肺组织形态学改变:模型组大鼠肺组织呈现间质性肺炎和肺泡性肺炎的病理学特点,茶多酚组肺炎状况明显改善。[结论]茶多酚水溶液能提高甲醛染毒大鼠肺组织SOD活性及GSH含量,降低MDA含量,使受损肺组织形态部分改善,表明茶多酚水溶液对甲醛染毒大鼠肺损伤具有一定的保护作用。     

过氧化甲乙酮对雄性大鼠肝脏的氧化损伤及病理学观察

目的研究过氧化甲乙酮(MEKP)对大鼠肝脏的氧化损伤作用。方法 50只SD雄性大鼠随机分成3个MEKP染毒组(50、500、1 000 mg/m3)和1个溶剂对照组(2,2,4-三甲基-1,3-戊二醇二异丁酸脂)、1个空白对照组,每组10只,每周吸入染毒5d,每天6 h,13周后观察肝脏的组织形态学损伤,测定肝脏组织的还原型谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力。结果 500、1 000 mg/m3剂量染毒组大鼠肝小叶周围汇管区出现细胞核浓缩、脂肪变性,肝细胞轻度水肿及淋巴细胞浸润等病理学变化。500和1 000 mg/m3组肝脏组织MDA水平升高,SOD活力下降,GSH含量下降,差异均有统计学意义(P0.05)。结论 MEKP可诱导大鼠肝脏组织氧化应激损伤及组织病理学结构的改变。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

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.