牛磺酸对染铅大鼠学习记忆影响的改善作用

目的　探讨牛磺酸 (Tau)对染铅大鼠学习记忆影响的改善作用。方法　 4 0只Wistar大鼠随机均分为 5组 :空白对照组、铅染毒组 (40mg·kg-1·d-1醋酸铅灌胃 4周 )、Tau 10 0mg组 (10 0mg·kg-1·d-1)、Tau 4 0 0mg组 (40 0mg·kg-1·d-1)、Tau 80 0mg组 (80 0mg·kg-1·d-1) :染铅后继续灌胃 4周。第 5～ 8周每周用方位水迷宫试验测试学习记忆能力 1次。第 8周末处死动物 ,测定全血铅和脑丙二醛 (MDA)、超氧化物歧化酶 (SOD)、谷胱甘肽 (GSH)、谷胱甘肽过氧化物酶 (GSH PX)、一氧化氮合成酶 (NOS)、乙酰胆碱酯酶 (AChE)等指标水平。结果　 (1)水迷宫实验中 ,各Tau治疗组大鼠逃逸时间均少于铅染毒组 ,其中Tau 80 0mg组在第 6、7、8周实验、Tau 4 0 0mg组在第 6周的实验中 ,逃逸时间与铅染毒组比较 ,差异有显著性 (P <0 .0 5 )。 (2 )Tau 10 0、4 0 0mg组大鼠血铅水平分别为 (5 10 .90±5 7.5 6 )、(485 .4 0± 98.85 ) μg/L ,与铅染毒组比较 ,差异有显著性 (P <0 .0 5 )。 (3)Tau 80 0、4 0 0mg组大鼠脑MDA水平、SOD活力、NOS活力、AChE活力以及Tau 80 0mg组GSH含量、GSH PX活力与铅染毒组比较 ,差异有显著性 (P <0 .0 5或P <0 .0 1)。结论　Tau可改善染铅大鼠的学习记忆能力 ,对铅染毒大鼠的大脑有一定的     

某冶炼厂环境铅污染及其对人群健康影响的研究

目的　比较某冶炼厂环境铅污染 1 5年前后的变化 ,为该厂扩建投产后污染变化评价提供依据。方法　选取 1 980～ 1 982年调查时污染区中的厂南区和对照区 ,于 1 995～ 1 997年再次调查两区稻米、蔬菜、井水中的铅含量以及学龄儿童的血铅及δ-氨基乙酰丙酸脱水酶 (δ -ALAD)活力 ,并比较两次调查结果。结果　本次调查样品的几何均值米铅 (干重 )、菜铅 (湿重 )、井水铅、学生血铅和δ -ALAD酶活力 ,污染区分别为 2 6.7± 1 .65mg/kg、60 .4± 2 .67mg/kg、0 .0 1 4± 0 .0 0 5mg/L、2 0 6± 1 .7μg/L和 98± 1 .3IU/L ,对照区分别为 1 3 .2± 1 .85mg/kg、4 4.9± 2 .84mg/kg、0 .0 2 0± 0 .0 0 5mg/L、2 2 9± 1 .3 μg/L和 2 2 5± 1 .4IU/L。两区比较米铅含量污染区高于对照区 ,而酶活力前者明显低于后者 (P <0 .0 1 ) ;污染区有 2 2个学生 (占 2 1 .2 % )超过对照区学生血铅最高值 ( 3 1 2 .9μg/L) ,其中 8人的血铅值高达 4 50～ 762 μg/L。与 1 980～ 1 982年调查结果相比 ,污染区的稻米蔬菜铅含量显著增加。结论　该冶炼厂对污染区的铅污染有不断累积加重的趋势。     

牛磺酸对染铅大鼠骨髓生化指标的影响

目的　探讨牛磺酸 (Tau)对染铅大鼠骨髓中一氧化氮 (NO)、谷氨酸 (Glu)信号分子等指标的影响。方法　将Wistar大鼠随机分为 2组 ,空白对照组和铅染毒组〔6 0mg/ (kg·d)〕的醋酸铅灌胃 ,然后将已染铅大鼠随机分为 4组 ,即铅对照组、3个牛磺酸治疗组〔2 0 0 ,4 0 0 ,80 0mg/ (kg·d)〕。Tau治疗 80d后处死动物 ,测定血铅和骨髓中NO、一氧化氮合酶 (NOS)、Glu、钙含量、巯基 ( SH)指标水平。结果　 (1 )各Tau治疗组大鼠血铅水平均低于铅对照组 ,差异有统计学意义 (P <0 0 5或P <0 0 1 )。 (2 )Tau 80 0mg组大鼠骨髓NO含量、总NOS活动、iNOS活力、巯基含量及Tau 4 0 0mg组Glu含量与铅对照组比较 ,差异有统计学意义 (P <0 0 5 )。结论　Tau能够调节铅暴露大鼠骨髓中信号分子NO、Glu的水平 ,能够拮抗铅的骨髓毒性。     

锌硒对铅致大鼠听力损伤的影响研究

目的 :主要研究铅中毒所致大鼠听力功能的损伤以及锌、硒的保护作用影响。方法 :染铅组大鼠灌胃 4mg/kg铅 (PbAC) ,补锌组同时灌胃 4mg/kg锌 (ZnSO4)和 4mg/kg铅 (PbAC) ,补硒组同时灌胃 2mg/kg硒(Na2 SeO3 )和 4mg/kg铅 (PbAC) ,对照组灌胃生理盐水 ,连续灌胃 30d ,脑干电诱发电位测定。结果 :染铅组大鼠脑干电诱发电位I波潜伏期为 2 2 8± 0 0 7ms ,明显长于对照组 (1 6 4± 0 0 5ms) ,补锌、硒组大鼠脑干电诱发电位I波潜伏期分别为 1 99± 0 0 7ms和 2 0 9± 0 0 4ms,明显短于染铅组而接近对照组。结论 :染铅组大鼠听力明显下降 ,而锌、硒能拮抗铅对大鼠听力功能的损害作用 ,使铅中毒引起的听力损失得到恢复。     

职业接触铅工人血细胞参数变化的调查

目的　对 5 98名工人的血铅及血细胞参数进行测定 ,以了解职业铅接触对工人造血系统的影响以及血细胞参数的变化。方法　据血铅测定水平将 5 98名职业接触铅工人分为 2组 :铅接触组 (血铅小于 2 .4 1μmol/ /L) 32 5名和铅吸收组 (血铅大于或等于 2 .4 1μmol/L) 2 73名。血铅测定采用石墨炉原子吸收法 ;血细胞参数的测定采用全自动血细胞分析仪进行测定。结果　铅吸收组的血红蛋白 (Hb) [男 :(12 9.3± 12 .3)g/L ,女 :(112 .2± 9.4 )g/L]、红细胞压积 (HCT) [男 :(0 .338± 0 .0 30 )L/L ,女 :(0 .30 2± 0 .0 2 8)L/L]明显低于正常组和铅接触组 ,差异均有显著性 (P <0 .0 5 ,P <0 .0 1) ;并且随血铅水平增高 ,Hb和HCT水平降低 ,血铅与Hb和HCT有弱的负相关关系。铅吸收组的红细胞平均分布宽度 (RDW) (男 :16 .6 8%± 0 .80 % ,女 :16 .98%± 0 .98% )明显高于正常组和铅接触组 ,铅接触组的RDW(男 :14 .77%± 0 .83% ,女 :14 .92 %± 1.13% )也明显高于正常组 ,差异均有显著性 (P <0 .0 5 ,P <0 .0 1) ;血铅与RDW有弱的正相关关系。结论　用Hb、HCT和RDW 3个指标可以反映铅作业工人是否贫血和贫血程度。     

锌缺乏对大鼠骨骼矿化的影响

目的　探讨缺锌对大鼠骨骼矿化的影响。方法　将 30只Wistar大鼠按体重随机分为缺锌组、对照组和对喂组 ,每组 10只。缺锌组饲料锌含量为 3 9mg/kg ,对照组饲料锌含量为 2 4 7mg/kg,对喂组饲对照组饲料 ,饲料摄入量与缺锌组相同。运用骨组织形态计量学方法测量骨骼矿化相关指标、测定股骨矿物质含量、骨密度、骨中锌、钙、磷、镁、锰、铜元素和骨骼羟脯氨酸含量及血中甲状旁腺激素、降钙素和骨钙素含量。结果　缺锌组大鼠与对照组和对喂组相比 ,骨矿化沉积速率、股骨磷、锌、骨羟脯氨酸及血清降钙素、骨钙素含量显著降低 ,缺锌组相应指标分别为 :( 3 2 6± 0 34) μm/d、( 6 4 5 4± 2 34)g/kg、( 5 4 4± 9 5 )mg/kg、( 9 2 8± 1 6 2 )g/kg、( 41 2± 13 5 ) μg/L、( 82± 30 ) μg/L ;对照组分别为 :( 5 37± 0 5 3) μm/d、( 6 9 0 1± 4 0 5 )g/kg、( 117 4± 8 0 )mg/kg、( 11 31± 1 30 )g/kg、( 6 8 3± 14 4)μg/L、( 131± 46 ) μg/L ;对喂组分别为 :( 5 45± 0 30 ) μm/d、( 6 7 81± 3 5 6 )g/kg、( 10 6 7± 8 4)mg/kg、( 10 88± 1 47)g/kg、( 6 3 7± 12 0 ) μg/L、( 12 0± 5 2 ) μg/L。骨矿化延迟时间和骨基质成熟时间显著增加 ,缺锌组相应指标分别为 :( 1 0 8± 0 19)     

铅对大鼠海马生长抑素神经元及其基因表达的影响

研究铅对大鼠海马不同亚区生长抑素 (SS)神经元及其基因表达的影响 ,Wistar大鼠采用饮水加2 0 0 0 μg ml醋酸铅 (PbAc)方法染毒 3个月后 ,用原子吸收分光光度法测定血液和海马铅的含量 ,并通过免疫组化和原位杂交技术检测海马SS和SSmRNA阳性神经元蛋白和基因表达。结果显示 ,染铅组大鼠血液和海马铅含量分别为 (1 30 0 5± 1 4 2 1 )mg L和 (1 0 1 1 62± 59 54)ng L ,较对照组的 (5 54± 0 76)mg L和 (1 81 98±47 2 7)ng L明显增高 ,差异有显著性 (P <0 0 5) ;染铅组大鼠海马CA1 区SS和SSmRNA阳性神经元数目分别为 (2 3 2 7± 4 58)和 (37 60± 9 69) ,较对照组的 (40 38± 7 61 )和 (53 48± 1 0 2 2 )明显减少 ,差异有非常显著性(P <0 0 1 ) ;染铅组大鼠海马CA3 区SS和SSmRNA阳性神经元数目为 (1 2 1 6± 3 40 )和 (1 6 1 8± 6 1 9) ,较对照组的 (1 7 68± 5 86)和 (2 5 93± 7 47)明显减少 ,差异有显著性 (P <0 0 5)。提示染铅后大鼠海马各区SS阳性神经元的蛋白、基因表达能力是降低的     

环境铅与幼儿体内铅水平及健康危害研究

目的　了解环境铅与幼儿体内铅水平及对幼儿体格发育的影响。方法　测定大气、食品、饮水等铅含量以及5 0 1例 3～ 6岁儿童发铅和血铅含量 ,并检查 2 6 4名儿童的体格发育情况。结果　计算获得市区幼儿每人每日摄入铅约 5 4 μg ,郊区约 4 5 μg ,市区和郊区幼儿发铅分别是 18 71± 8 8μg/g和 13 97± 8 0 μg/ g:血铅分别是 131 2± 72 1μg/L和 10 8 3± 6 8 1μg/L(1μg/L =0 0 0 4 83μmol/L) ;市区幼儿的发铅和血铅水平显著高于郊区 ,P <0 0 0 1;市区幼儿血铅≥ 10 0 μg/L者占 6 9 8% ,郊区占 4 0 1% ;以血铅 10 0 μg/L划线分组比较幼儿体格发育 ,各年龄段幼儿血铅 <10 0μg/L和≥ 10 0 μg/L组的身高、体重、胸围、头围和血色素含量无显著性差异。 结论　成都市环境铅污染严重 ,幼儿血铅水平及铅中毒流行率较高 ,应重视防治儿童铅中毒。     

醋酸铅对大鼠脑细胞凋亡及bcl-2基因表达的影响

目的　探讨醋酸铅 (PbAc)对大鼠脑细胞凋亡的诱发作用及对bcl 2基因表达的影响。方法　SD大鼠腹腔分别注射PbAc 2 5、5 0、10 0mg/kg 5d ,第 6天用流式细胞仪分别测定其大脑皮层、海马和小脑组织的细胞凋亡率和bcl 2基因的表达产物Bcl 2蛋白含量。结果　染铅大鼠大脑皮层、海马、小脑细胞凋亡率 (% ) :2 5mg/kgPbAc组为 5 .80± 0 .87、4.82± 0 .37、4.82± 1.2 3 ,5 0 mg/kg组值高于 2 5mg/kg组 ,10 0mg/kg组值高于 5 0mg/kg组 ,均比对照组 (1.40± 0 .70、2 .0 0± 0 .6 3、1.6 6±0 .49)高 ,差异有显著性 (P <0 .0 1) ;并有剂量 -反应关系 (r值分别为 0 .998、0 .989、0 .997)。染铅大鼠大脑皮层、海马、小脑bcl 2基因表达 (FI指数 ) :2 5mg/kgPbAc组为 0 .6 8± 0 .0 3、0 .6 1± 0 .0 6、0 .6 9± 0 .0 5 ;5 0mg/kg、10 0mg/kg组值均与 2 5mg/kg组接近 ,但均比对照组 (1.0 0± 0 .13、1.0 0±0 .17、1.0 0± 0 .13)降低 ,差异有显著性 (P <0 .0 1) ;并有剂量 -反应关系 (r值分别为 0 .886、0 .787、0 .832 )。大鼠大脑皮层、海马和小脑细胞凋亡率与Bcl 2含量呈负相关 (r值分别为 - 0 .75 0、- 0 .5 0 9、- 0 .6 6 7)。结论　铅可以诱发大鼠脑细胞凋亡 ,其机制可能与脑组织内bcl 2基因表达下调有关     

铅对大鼠脑组织神经生长因子表达的影响及甲状腺激素的调节作用

目的　研究醋酸铅对大鼠脑组织神经生长因子 (NGF)表达的影响及甲状腺激素的调节作用。方法　对SD大鼠用 2 5、5 0、10 0mg/kg体重的醋酸铅腹腔注射 ;用丙基硫氧嘧啶 (PTU)制作甲状腺机能减退大鼠模型 ,再给予 5 0mg/kg体重的醋酸铅 ,分别以免疫组化测定脑组织中NGF蛋白的表达。以放射免疫方法测定血清中三碘甲状腺原氨酸 (T3 )、甲状腺素 (T4)、促甲状腺激素 (TSH)的含量及脑组织中T3 、T4的含量。结果　中、高剂量组皮层组织NGF平均灰度 (180 .4 9± 10 .33、16 9.72±19 .75 )与对照组 (2 0 0 .75± 3.2 7)相比 ,差异有显著性 (P <0 .0 1) ;各剂量组海马组织NGF面密度 (0 .0 8± 0 .14、0 .12± 0 .0 2、0 .13± 0 .0 4 )与对照组 (0 .0 2 5± 0 .0 15 )相比 ,差异有显著性 (P <0 .0 5 )。甲状腺机能减退后再用醋酸铅处理 ,皮层、海马组织NGF面密度和平均灰度未见明显改变。各剂量染铅组大鼠血清中T3 [(0 .6 8± 0 .0 2 )、(0 .5 7± 0 .0 4 )、(0 .5 4± 0 .0 2 ) μg/L]和T4[(2 8.30± 1.83)、(2 7.35± 2 .5 5 )、(2 4 .0 0± 3.0 1) μg/L]含量明显下降 ,而TSH[(6 .34± 1.13)、(7.74± 0 .79)、(9.16± 0 .77)IU]增高 ,与对照组T3 [(0 .97± 0 .14 ) μg/L]、T4[(5 4 .5 0± 3.70 ) μg/L]和TSH     

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.