芹菜素对乙酸铅染毒小鼠脑组织中脂质过氧化指标的影响

目的探讨芹菜素对乙酸铅染毒小鼠脑组织的脂质过氧化指标影响。方法将健康成年昆明小鼠50只按体重随机分为正常对照组、染铅模型组及芹菜素低、中、高剂量组,每组10只。空白对照组给予等量的生理盐水,其他各组腹腔注射0.1 g/L乙酸铅[1 mg/(kg·d)]对小鼠染毒,连续1周。染毒结束后,芹菜素低、中、高剂量组每天给予芹菜素灌胃(350、700、1 400 mg/kg),其他组仅给予等体积的食用植物油灌胃,持续30 d。检测小鼠血铅、脑铅含量及脑组织中过氧化脂质(LPO)、丙二醛(MDA)含量和超氧化物岐化酶(SOD)、过氧化氢酶(CAT)的活力。结果与空白对照组比较,各染铅组小鼠血铅、脑铅含量均升高,脑组织中SOD、CAT活力均下降,MDA、LPO含量均升高,差异有统计学意义(P0.01)。与染铅模型组比较,芹菜素中、高剂量组血铅、脑铅含量明显降低,SOD活力升高,MDA含量降低;3个剂量组CAT活力均升高,LPO含量均下降,差异均有统计学意义(P0.05或P0.01)。结论芹菜素可以降低乙酸铅染毒小鼠血铅、脑铅水平,升高小鼠脑组织SOD和CAT活力,降低MDA和LPO含量,减轻脑组织的脂质过氧化损伤。     

乙二醛对小鼠脂质过氧化物水平及SOD活性的影响

目的 测定乙二醛染毒小鼠血清及组织中脂质过氧化主要产物丙二醛(MDA)的含量和超氧化物歧化酶(SOD)活力的变化,以探讨乙二醛毒性的可能机制。方法 40只小鼠分成1个对照组和3个实验组,实验小鼠的染毒剂量分别为1．29,mmol／kg、2．58mmol／kg和5．16mmol／kg,每天腹腔注射1次,连续染毒30d。用硫代巴比妥酸(TBA)比色法测定血清及组织中MDA含量,用黄嘌呤氧化酶法测定全血及组织中SOD活性。结果 乙二醛染毒小鼠高剂量组肾脏MDA含量与对照组相比显著升高,其他各项指标与对照组相比差异均无显著性;小鼠全血、肝脏和肾脏中SOD活性变化与对照组相比差异均无显著性。结论 乙二醛能够增高小鼠肾脏MDA含量,提示有可能导致肾组织氧化损伤。     

甲醛和苯联合染毒对雄性小鼠睾丸的毒性作用

目的 研究甲醛和苯联合染毒对雄性小鼠睾丸组织的毒性作用,为综合评价甲醛和苯的安全性提供科学依据.方法 选用78只健康清洁级昆明种纯系雄性小鼠为研究对象,按染毒剂量分为低(0.2 mg/kg)、中(2 mg/kg)、高(20 mg/kg)剂量甲醛组,以生理盐水为阴性对照组;低(100.0mg/kg)、中(200.0mg/kg)、高(400.0mg/kg)剂量苯组,以花生油为阴性对照组;低(0.1 mg/kg甲醛 50.0 mg/kg苯)、中(1 mg/kg甲醛 100.0 mg/kg苯)、高(10 mg/kg甲醛 200.0 mg/kg苯)剂量联合染毒组,以生理盐水 花生油为阴性对照组;以环磷酰胺(40 mg/kg)为阳性对照组.采用腹腔注射染毒,注射容量为0.01 ml/g,每日1次,连续5 d.染毒结束次日,处死小鼠,测定睾丸组织中超氧化物歧化酶(SOD)活力、丙二醛(MDA)、Cu、Zn含量.结果 甲醛、苯单独染毒组及联合染毒组的SOD活力、Cu、Zn含量均低于其阴性对照组,且随染毒剂量的升高而下降;MDA含量均高于其阴性对照组,且随染毒剂量的升高而上升.联合染毒组染毒剂量与SOD活力呈负相关(r=-0.967,P＜0.01),与MDA含量呈正相关(r=0.941,P＜0.01).与甲醛、苯单独染毒比较,联合染毒组SOD活力、Cu、Zn含量呈下降趋势,MDA含量呈升高趋势.结论 甲醛和苯联合染毒对小鼠睾丸组织的毒性作用大于甲醛、苯单独染毒时的作用;二者对小鼠睾丸组织的联合毒性作用可能具有协同作用.     

正己烷致大鼠过氧化损伤及肝细胞凋亡的实验研究

目的研究正己烷(n-hexane)对大鼠的脂质过氧化损伤和肝细胞凋亡的影响。方法40只雄性SD大鼠随机分成5组,即阴性对照组、染毒组(75、150、300 mg/kg)和阳性对照组(环磷酰胺),每组8只。经腹腔注射染毒4周后,检测肝组织匀浆超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活力,血清还原型谷胱甘肽(GSH)和丙二醛(MDA)含量;用流式细胞仪检测肝细胞凋亡情况。结果随着染毒剂量的增加,肝组织匀浆中SOD、GSH-Px活力、血清GSH含量降低,而血清MDA含量增大,组间比较差异有统计学意义(P<0.05或P<0.01),流式细胞仪检测结果显示,肝细胞凋亡率(AV /PI-)组间比较差异有统计学意义(P<0.01),与染毒剂量作相关分析,相关系数为0.913,无明显的相关性(P>0.05)。结论正己烷可引起或增强机体氧自由基反应,导致脂质过氧化损伤,引起肝细胞凋亡和坏死。     

甲醛对小鼠的免疫毒性及氧化损伤的研究

目的 探讨甲醛对小鼠脾脏、胸腺T细胞亚群CD3、CD4、CD8含量和超氧化物歧化酶(superoxide dismutase,SOD)活力和丙二醛(maleic dialdehyde,MDA)含量的影响.方法 将昆明种小鼠随机分成5组(即阴性对照组,1、3、5 mg/m3染毒组和阳性对照组),每组6只.染毒组用静式吸入染毒方式染毒,每天染毒2 h,持续14 d.阴性对照组在同样的染毒柜中吸入过滤的新鲜空气,处理时间与染毒组相同.阳性对照组从第8天开始,每日按40 mg/kg体重腹腔注射环磷酰胺(CP),连续7 d,测定脾脏、胸腺中T细胞亚群CD3、CD4、CD8含量、SOD活力、MDA含量.结果 随甲醛染毒剂量的增高,小鼠脾脏、胸腺CD3、CD4、CD8含量呈明显下降趋势,CD4/CD8随染毒剂量的升高而明显增大.除1 mg/m3染毒组小鼠脾脏CD3、CD4含量及3 mg/m3染毒组CD4含量外,其他染毒组CD3、CD4、CD8含量与阴性对照组比较,差异均有统计学意义(均P＜0.05或P＜0.01),并且CD3、CD4、CD8阳性细胞数与甲醛染毒剂量间有明显的剂量-反应关系(r值分别为0.771、0.660、0.914,均P＜0.01).除1 mg/m3染毒组小鼠胸腺CD3、CD4、CD8含量外,其他染毒组CD3、CD4、CD8含量与对照组比较,差异均有统计学意义(P＜0.05或P＜0.01),并且CD3、CD4、CD8阳性细胞数与甲醛染毒剂量间有明显的剂量-反应关系(r值分别为0.881、0.763、0.969,均P＜0.01),与阴性对照组比较,差异有统计学意义(P＜0.05或P＜0.01).除1 mg/m3组小鼠胸腺SOD活力与阴性对照组比较,差异无统计学意义(P＞0.05)外,其他染毒组小鼠脾脏和胸腺的SOD活力与阴性对照组比较,差异均有统计学意义(P＜0.05或P＜0.01);各染毒组小鼠胸腺和脾脏MDA含量均显著高于阴性对照组,差异有统计学意义(P＜0.05或P＜0.01).各染毒组小鼠脾脏和胸腺T细胞亚群含量分别与其脾脏和胸腺的SOD活力成正相关(P＜0.01),与MDA含量成负相关(P＜0.01).结论 甲醛可引起小鼠脾脏、胸腺T细胞亚群CD3、CD4、CD8损伤和脾脏、胸腺脂质过氧化损伤;脂质过氧化损伤可能是甲醛导致免疫损伤的作用机制之一.     

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）。     

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。     

壳聚糖对镉致小鼠睾丸损伤的干预作用

目的探讨壳聚糖对镉致小鼠睾丸损伤的干预作用。方法50只健康昆明种雄性小鼠,随机分为5组,即对照组,单纯镉染毒组,壳聚糖50、150、450mg/kg 3个剂量干预组。壳聚糖干预组分别灌胃50、150、450mg/kg壳聚糖,对照组和单纯镉染毒组灌胃蒸馏水。2h后单纯镉染毒组和各剂量壳聚糖干预组腹腔注射氯化镉0.8mg/kg,对照组腹腔注射蒸馏水。连续14d。末次染毒后处死动物,剖取附睾和睾丸,分别测定精子畸形率、睾丸超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。结果小鼠染毒14d后,各处理组小鼠精子畸形率明显升高,与对照组比较,差异有统计学意义(P<0.05);睾丸SOD活力明显下降,其中单纯镉染毒组与对照组比较,差异有统计学意义(P<0.05);其余各剂量壳聚糖干预组与对照组比较,差异均无统计学意义(P>0.05)。MDA含量明显升高,与对照组比较,单纯镉染毒组、50和150mg/kg壳聚糖干预组差异有统计学意义(P<0.05)。随着壳聚糖摄入剂量的逐渐升高,小鼠精子畸形率有所降低,睾丸SOD活力有所升高,MDA含量有所下降,与单纯镉染毒组比较,差异均有统计学意义(P<0.05)。结论壳聚糖对镉致小鼠睾丸损伤有一定的干预作用。     

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。     

壬基酚对小鼠子宫氧化损伤效应的研究

为探讨壬基酚(NP)对小鼠子宫的氧化损伤效应,将32只健康SPF级雌性昆明小鼠按体重随机分为4组,分别为对照(玉米油)组和25、50、100 mg/kg NP染毒组,每组8只。采用经口灌胃方式进行染毒,每天1次,每周连续染毒5 d,共染毒8周。测定子宫总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活力及丙二醛(MDA)含量。结果显示,与对照组比较,50、100 mg/kg NP染毒组小鼠子宫的T-AOC、SOD活力均降低,而MDA含量均升高(均P0.05);而25 mg/kg NP染毒组小鼠子宫的T-AOC、SOD活力和MDA含量均无明显变化。且随着NP染毒剂量的升高,小鼠子宫的T-AOC、SOD活力均呈下降趋势,而MDA含量呈上升趋势。提示NP染毒可致小鼠子宫发生氧化损伤。     

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.