经口镉染毒大鼠前列腺中金属硫蛋白基因表达水平的变化

目的 观察经口镉染毒对大鼠前列腺组织中锌、镉含量以及金属硫蛋白（MT）基因表达水平的影响。方法 48只大鼠随机分成8组，每组6只，其中设对照组和50、100、200mg/kg镉染毒组各2组。大鼠通过饮水给予氯化镉，并分别在染毒1个和6个月后分批（每批4组）处死大鼠。大鼠前列腺组织中锌、镉含量的测定采用原子吸收光谱法，而金属硫蛋白基因（MT－I和MT-Ⅱ）表达水平的测定采用RT－PCR的方法。结果 在镉染毒的每1个月和第6个月，随着镉染毒剂量的增加，锌在大鼠前列腺腹叶中的含量呈逐渐降低的趋势。其中在镉染毒1个月和6个月后，200mg/kg镉染毒组大鼠前列腺腹叶中锌的含量分别为9．5、8．5μg/g湿重，明显低于对照组的17．0、18．9μg/g湿重，差异有显著性（P＜0．05）。与锌相反，各染毒组大鼠前列腺腹叶和背侧叶中镉的含量均明显高于对照组，尤以背侧叶增高的幅度更明显。MT－I和MT－Ⅱ在前列腺腹叶的表达水平随着镉染毒剂量的增大而呈逐渐降低趋势；在染毒第1个月和第6个月，200mg/kg镉染毒组的MT－I基因相对表达丰度为0．410和0．339，MT－Ⅱ基因相对表达丰度为0．100和0．112，均明显低于对照组MT－I（0．760，0．830）和MT－Ⅱ（0．429，0．439）相对表达丰度，差异有显著性（P＜0．01）。显著 经口镉染毒能影响大鼠前列腺组织中锌、镉的含量和MT基因表达的水平。     

镉诱导PC-3细胞金属硫蛋白和锌转运体的基因表达

[目的]研究镉对前列腺癌PC-3细胞中金属硫蛋白(Metalllothionein,MT)和锌转运体(Zinctransporter,ZnT)基因表达的影响。[方法]0、10、20、40、80和100μmol/L氯化镉处理PC-3细胞,细胞存活率用噻唑蓝(MTT)方法检测;MT-1F、MT-1X、MT-2A和ZnT-1基因的mRNA表达用RT-PCR进行检测。[结果]氯化镉(≥40μmol/L)对PC-3细胞具有明显的抑制生长作用(P<0.05)。MT-1F和MT-2A的mRNA水平在5μmol/L氯化镉诱导时表达水平达最高,随着氯化镉浓度的增高mRNA的表达呈下降趋势。MT-1X的mRNA表达水平随氯化镉浓度增加呈不断上升趋势,在40μmol/L表达水平为最高。ZnT-1的mRNA在10μmol/L氯化镉诱导表达水平为最高,随着氯化镉浓度的增高mRNA表达呈下降趋势。[结论]镉可诱导PC-3细胞MT-1F、MT-1X、MT-2A和ZnT-1基因mRNA表达增高。     

镉诱导人胚肾细胞金属硫蛋白基因亚型的表达

[目的]研究镉对人胚肾细胞（HEK293T）金属硫蛋白（MT）各基因亚型表达的影响。[方法]以10μmol/LCdCl2染毒HEK 293T0、2、4、8、12、16、20、24h,2.5、5、10、20、40μmol/LCdCl2染毒HEK293T24h后,采用MTT法测定HEK 293T增殖活性;采用RT-PCR检测镉对HEK 293T MT-1A、MT-1B、MT-1E、MT-1F、MT-1G、MT-1H、MT-1X及MT-2A mRNA表达的影响。[结果]CdCl2染毒HEK 293T 24h后,经10μmol/LCdCl2诱导后,随时间MT-1A、MT-1F、MT-1G、MT-1H及MT-2A mRNA表达水平均呈先升高后降低趋势。MT-1X mRNA水平在8h明显升高（P〈0.05）,16h达到峰值并持续到24h。5μmol/L以上CdCl2均可明显抑制HEK293T活力,与对照组相比差异均有统计学意义（P〈0.05）。MT-1A、MT-1F、MT-1G、MT-1H及MT-2A mRNA在2.5μmol/LCdCl2诱导表达水平均达到峰值,随着剂量增加,MT-1F、MT-1G、MT-1H维持在较高水平,40μmol/L剂量水平仍明显高于对照组（P〈0.05）,MT-1A、MT-2A在40μmol/L降低到基础表达水平。MT-1X mRNA表达水平与染毒剂量呈线性正相关（r=0.75,P〈0.01）。MT-1X的表达与镉对HEK 293T毒性呈负相关关系（r=-0.88,P〈0.01）。[结论]镉可以诱导MT-1F、MT-1G、MT-1H、MT-1X及MT-2A mRNA表达水平明显升高,并表现出特定的剂量-效应和时间-效应关系。     

镉对小鼠睾丸细胞DNA损伤及锌保护作用研究

目的 建立亚慢性镉中毒动物模型并研究镉对雄性小鼠睾丸细胞DNA损伤，及锌对亚慢性镉中毒的保护作用。方法 以不同剂量的氯化镉(0．4，0．8，1．6mg／kg)每天在ICR小鼠背部行皮下注射，连续7周。锌保护组在皮下注射1．6mg／kg体重氯化镉溶液的同时给予350μg／ml硫酸锌水溶液喂饲7周。动物处死后，取一侧睾丸做单细胞凝胶电泳实验以观察睾丸细胞DNA损伤水平，另一侧睾丸作病理切片镜下观察其组织形态变化。结果 各组血、肝镉浓度随染毒剂量增加而增加，呈现明显相关关系。病理损伤随剂量的增加而明显加重。睾丸细胞DNA损伤水平和损伤程度与染毒剂量呈现剂量—反应关系。高剂量染毒组部分睾丸细胞彗星图像呈凋亡改变。结论 亚慢性镉染毒可造成雄性小鼠睾丸组织的病理损伤，也可以引起睾丸细胞DNA损伤，且呈剂量—反应关系。锌对镉的亚慢性毒作用具有一定的保护作用，但锌似无驱镉作用，也不能降低镉中毒引起的睾丸细胞DNA损伤。     

镉经饮水染毒对去卵巢大鼠维生素D3代谢的影响

[目的 ]探讨镉经饮水染毒对去卵巢大鼠维生素D3 代谢的影响。 [方法 ]将雌性 6月龄SD大鼠行人工去卵巢术 ,分别经饮水给不同剂量的镉 ,2 4周后处死。用放射免疫法测定 2 5 羟维生素D3 和 1,2 5 双羟维生素D3 ,石墨炉原子吸收法测定血、尿镉 ,放射免疫法测定血清雌二醇、甲状旁腺激素 ,同时测定肾功能指标尿 β2 微球蛋白、尿N 乙酰 β D 氨基葡萄糖苷酶和尿钙。 [结果 ]去卵巢大鼠体内雌二醇下降 ,甲状旁腺激素显著升高。经镉染毒的去卵巢大鼠体内 1,2 5 双羟维生素D3 的水平降低 ,且有剂量 效应关系。而各组血清 2 5 羟维生素D3 水平无明显差异。与对照组相比 ,各镉染毒组的尿钙、β2 微球蛋白及NAG水平均升高 ,高剂量组 (2 0 0mg/L)有显著性差异。血液 1,2 5 (OH) 2 D3 水平与肾小管损伤指标尿 β2 微球蛋白及尿钙呈显著性负相关。 [结论 ]结果提示镉接触能造成去卵巢大鼠维生素D3 代谢损害 ,主要使活性维生素D3 水平下降 ,且与镉导致的肾功能损害相关     

硒对镉诱导的大鼠肝脏端粒酶逆转录酶和c-Myc及p53表达的影响

目的研究亚硒酸钠时氯化镉诱导的大鼠肝脏端粒酶逆转录酶（TERT）mRNA、c-Myc蛋白、p53蛋白表达的影响。方法健康雄性SD大鼠随机分为6组，对照组、硒组（5μmol／kg亚硒酸钠）、5μmol／kg氯化镉组、10μmol／kg氯化镉组、研（5μ／kg亚硒酸钠）＋5μmol／kg氯化镉组、硒（5μmol／kg亚硒酸钠）＋10μmol／kg氯化镉组。每组动物5只，染毒48h后取出肝脏，用RT-PCR方法检测TERP基因的表达，用免疫组织化学方法检测c-Myc蛋白和p53蛋白的表达。结果与对照组比较，5μmol／Lkg氯化镉组和10μmol／kg氯化镉组TERP表达增多，10μmol／L kg氯化镉组c-Myc蛋白表达增多，5μmol／L kg氯化镉组和10μmol／L kg氯化镉组p53蛋白表达增多。TERT的表达，硒＋10μmol／Lkg氯化镉组与10μmol／L kg氯化镉组比较降低；硒＋10μmol／L kg氯化镉组比10μmol／L kg氯化镉组c-Myc蛋白表达降低；硒＋5μmol／L kg氯化镉组、硒＋10μmol／L kg氯化镉组与相对应的镉组比较p53蛋白表达降低。结论镉在5～10μmol／L kg的剂量条件下可以诱导大鼠肝脏高表达TERT、c-Myc蛋白和p53蛋白，而硒对镉引起的TERT、c-Myc蛋白和p53蛋白的表达增高具有一定的拮抗作用。     

氯化镉染毒小鼠器官中微量元素分析

氯化镉染毒小鼠器官中微量元素分析王晓梅李建秀（河北省邯郸医学高等专科学校邯郸０５６００２）镉对人的多种器官具有危害，而锌能对抗镉，具有保护作用。本实验通过分析氯化镉染毒小鼠肝、肾及睾丸中的微量元素以探讨锌对于镉损伤的保护作用。材料和方法选用体重为１８...     

镉致成骨细胞增殖、分化及矿化损伤的预后效应

[目的]探讨镉染毒和染毒中止后成骨细胞增殖、分化及矿化等生物学功能的改变。[方法]采用混合酶消化法,分离sD大鼠颅盖骨成骨细胞,在5％CO2、37℃条件下培养24h后,持续镉染毒组以不同浓度的氯化镉（0～2．000μmol／L）持续染毒72h;间断镉染毒组以同样浓度的氯化镉染毒48h后,更换成无镉培养液继续培养24h,以噻唑蓝（MTT）法测定细胞增殖能力改变,用对硝基苯磷酸二钠盐（PNPP）偶氮法检测碱性磷酸酶（ALP）活性。同时,成骨细胞培养7d后,以0．500μmol／L氯化镉持续作用3—13d,然后分别停止作用10、8、6、0d,采用茜素红S进行矿化结节染色并计算面积以观察镉暴露中止后成骨细胞矿化能力损伤的恢复情况。[结果]氯化镉可明显抑制成骨细胞增殖、ALP活性及矿化能力。间断镉染毒组在停止作用24h后,成骨细胞的增殖、分化仍然明显低于对照组（P〈0．05）,与持续作用组比较没有明显改善。同样,间断镉染毒组在停止作用不同时间后,成骨细胞矿化结节数量和面积仍然明显低于对照组（P〈O．05）,与持续作用组相比没有明显恢复。[结论]镉暴露中止一定时间后,镉对成骨细胞的影响作用仍明显存在,表现为对成骨细胞增殖、分化及矿化能力的持续抑制。     

邻苯二甲酸单乙基乙基酯和镉联合作用对大鼠血清氧化应激的影响

目的研究邻苯二甲酸单乙基乙基酯[mono-(2-ethylhexyl)phthalate,MEHP]和镉联合作用对大鼠血清氧化应激指标的影响。方法采用3×3析因设计,将54只成年清洁级SD雄性大鼠随机分为9组,分别为对照(4.5%DMSO)组和10、250 mg/kg MEHP染毒组及1、3 mg/kg氯化镉染毒组以及MEHP(10、250 mg/kg)+氯化镉(1、3 mg/kg)染毒组,每组6只。采用灌胃方式进行染毒,染毒容量为10 ml/kg,连续染毒28 d。测定大鼠血清中丙二醛(MDA)含量和总超氧化物歧化酶(TSOD)、谷胱甘肽过氧化物酶(GSH-Px)活力。结果与对照组比较,各组大鼠血清MDA含量均较高,GSH-Px和T-SOD活力均较低,除各浓度氯化镉染毒组及10 mg/kg MEHP染毒组外,差异均有统计学意义(P0.05)。MEHP和氯化镉联合染毒对MDA的影响不存在交互作用(P0.05);10 mg/kg MEHP+1 mg/kg氯化镉染毒对T-SOD的影响存在交互作用(P0.05),表现为拮抗效应;250 mg/kg MEHP+3 mg/kg氯化镉染毒对GSH-Px的影响存在交互作用(P0.05),表现为协同效应。结论 MEHP和镉联合染毒可以造成大鼠氧化损伤,其具体作用机制有待进一步研究。     

镉致DNA损伤及对原癌基因蛋白表达的影响

目的 研究氯化镉致人细胞和整体动物DNA损伤作用和对原癌基因等相关蛋白表达的影响.方法 雄性Wistar大鼠,体重约150 g,按每组8只分为1个对照组和2个染毒剂量组,以生理盐水配制氯化镉溶液经皮下注射进行染毒,剂量分别为5和20 μmol/kg,对照组注射生理盐水.用集落形成实验和四唑盐比色法（MTT）测定氯化镉的细胞毒性,用彗星实验检测氯化镉对DNA的损伤,采用流式细胞术测定细胞周期的变化,用免疫印迹和X-Gal染色检测相关蛋白的表达改变.结果 镉能明显抑制细胞增殖,对人成纤维和整体动物细胞DNA有明显的损伤作用,成纤维细胞彗星细胞率由对照组的6.1%增加到200μM剂量组的23.2%,差异有统计学意义（P＜0.01）.雄性大鼠各个脏器在镉染毒后彗星细胞的频率均随剂量的增高而增加,其中肾和腹侧前列腺的DNA损伤同对照组比较差异有统计学意义（P＜0.05）,镉能进一步引起细胞周期阻滞.原癌基因c-myc、c-Jun和老化标记蛋白β-Gal均被氯化镉诱导增加.结论 氯化镉能致DNA损伤并进一步引起细胞周期停滞,导致细胞老化、死亡.氯化镉诱导细胞的DNA损伤和原癌基因表达的增加也可能是镉致癌的重要原因.     

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.     

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.     

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.     

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.