Patterns of Urban Mercury Contamination Detected by Bioindication With Terrestrial Isopods

Mercury (Hg) is a trace element with high toxicological impact on potential receptors, including human beings. Global Hg emissions are predicted to increase significantly during the next 40 years. After emission, the metal is transported by air currents and precipitations, leading to increasing depositions even in areas far from emission sources. In the terrestrial environment, Hg is subjected to redistribution and transformation into different inorganic and metal-organic species that are taken up by vegetation and soil organisms. In the present study, the woodlouse (Porcellio scaber) was used as a biological indicator of total Hg pollution in the city of Dornbirn (province of Vorarlberg), Austria. Woodlice were collected from 30 sampling points scattered over the city area, 25 of them situated within a rectangular transect crossing the city area from west-northwest to east-southeast, starting near the Rheintal motorway and ending at the slopes of the Bregenzer Wald hills. In addition to woodlice, soil substrate samples were collected at nine of the selected sampling points. Total Hg concentrations were measured in isopod tissues and soil substrate samples by means of an Hg analyzer. Total Hg concentrations in isopod tissues were significantly correlated with Hg soil contents (P < 0.05). Moreover, a gradient of increasing Hg concentrations was observed in isopod samples along the transect across Dornbirn, with the lowest concentrations detected in woodlouse samples near the Rheintal motorway and the highest levels toward the ascending slopes of the Bregenzer Wald hills. This gradient of increasing Hg concentrations across the city matches a concomitant increase in wet precipitations along the same direction, indicating that deposition by wet precipitation may be an important source for Hg contamination in the city of Dornbirn. Overall, the degree of Hg contamination across the study area can be regarded as rather low, i.e., comparable with concentrations observed in other, unpolluted terrestrial habitats. It is concluded that bioindication by total Hg analysis in woodlice can be applied to distinguish between different levels and sources of contamination in urban areas.     

Effect of Metal Mixtures (Cd and Zn) on Body Weight in Terrestrial Isopods

The aim of this study was to determine the effect of exposure to cadmium and zinc mixtures on the weight of terrestrial isopods. Experiments were conducted using uncontaminated specimens of P. laevis. The isopods were exposed to various concentrations of cadmium and zinc sulfate in single- and mixed-metal experiments. The mean weight of the unexposed isopods in the control group increased over the 6 weeks of observation. It was concluded that cadmium and zinc, administered separately, had a negative effect on the weight of P. laevis. The weight change (gain or loss) of P. laevis in the exposures to mixtures of cadmium and zinc sulfate were different from those of woodlice where Cd and Zn were administered separately. Combination of the lowest concentrations of Cd and Zn (20 and 1000 mg · kg^-1) produced a stimulating effect compared to the control. Weight changes of the other two combinations of Cd and Zn (80/4000 and 160/8000 mg · kg^-1) showed no differences from those of the control, and weight changes of woodlice exposed to Cd and Zn mixtures were mostly the same as those of the control over the 6-week exposure period. It can thus be concluded that mixtures of Cd and Zn have an antagonistic effect on each other in terms of weight of P. laevis.     

镉对小白鼠睾丸附睾影响的定量组织学研究

镉处理后的小白鼠睾丸,早期,间质水肿、血管扩张。给药一周后,睾丸萎缩,六周后,睾丸重量下降62%,曲细精管相对体积减小38%,而间质(间质细胞和结缔组织)相对体积增加70%左右。附睾重量也稍减轻,附睾头郎附睾管正皮相对体积减小,而管间结缔组织增加。镉对附睾的损害可用锌来预防。     

五溴联苯醚对大鼠甲状腺结构和功能的影响

目的研究五溴联苯醚(BDE-99)对大鼠甲状腺结构和功能的影响。方法将健康清洁级4周龄SD大鼠40只随机分为溶剂对照(玉米油)组和低(30mg/kg)、中(60mg/kg)和高(120mg/kg)剂量BDE-99染毒组,每组10只。采用灌胃方式进行染毒,染毒剂量为2.5ml/kg体重,连续染毒15d。采用放射免疫法测定游离三碘甲状腺原氨酸(FT3)、游离四碘甲状腺原氨酸(FT4)和促甲状腺素(TSH)的浓度。分别采用二氨基联苯胺(DAB法)和四唑氮(NBT)法对甲状腺过氧化物酶(thyroperoxidase,TPO)和琥珀酸脱氢酶(succinate dehydro-genase,SDH)的酶组织化学情况进行观察,并采用免疫组化检测和HE染色观察组织病理改变。电镜下观察甲状腺滤泡细胞超微结构改变。结果随着BDE-99染毒剂量的升高,血清FT4、FT3浓度呈降低趋势,而血清TSH浓度则呈升高趋势;甲状腺组织的TPO、SDH活力呈降低趋势,甲状腺组织的PCNA阳性细胞数则呈升高趋势。BDE-99染毒组TPO、SDH显色加深,电镜观察可见甲状腺滤泡细胞胞浆内有大量明显扩张呈囊状的粗面内质网,胞核、胞膜和线粒体未见损伤。结论 BDE-99有可能通过降低甲状腺球蛋白的合成水平而减低甲状腺激素的浓度,反馈性升高TSH浓度,从而导致腺体组织代偿性增生、细胞酶活力增高。     

Effects of the Antibiotic Amoxicillin on Key Species of the Terrestrial Environment

The antibiotic amoxicillin (AMX) is globally important for human and animal health. Although AMX is considered as a threat for the aquatic and terrestrial environment, limited data are present for its toxicity against key species such as denitrifying bacteria in soil, earthworms and plants. In the present research, the OECD protocols for environmental risk assessment were applied to study AMX acute toxicity, at nominal concentrations, close to the environmentally relevant, in soil bacteria responsible for nitrogen cycling, in the earthworm species Eisenia fetida and six plant species. The results revealed no significant effects of the antibiotic on the parameters related to the end-points of each respective test, at the selected concentration range. Therefore, the antibiotic did not present acute toxicity for the species, under the framework of the OECD tests. Further research is essential to be conducted also considering the patterns of degradation of AMX during the experimental periods.     

矽肺的定量危险度评价

矽肺是由于长期吸入矽尘所致的以肺部弥漫性纤维化为主的全身性疾病 ,是一种常见的且危害最为严重的职业病。定量危险度评价 (ｑｕａｎｔｉｔａｔｉｖｅｒｉｓｋａｓｓｅｓｓｍｅｎｔ)是研究与暴露环境和职业毒物有关的健康危险度而发展起来的一门方法学 ,主要用于预测暴露因子可能产生的健康效应类型 ,估计这些健康危害发生的概率并提出环境中可能接受的暴露因子水平。为了对矽肺的危险度作一定量评价 ,近十几年来 ,国内外学者作了不懈努力 ,现就这些学者研究的评价模型、评价结果及影响评价的因素作一扼要阐述。1　评价模型鉴于矽肺的累积…     

缺锌及补锌对大鼠甲状腺激素的影响

目的了解锌缺乏及补锌对大鼠甲状腺激素的影响。方法将出生后断乳1周的SD大鼠随机分为缺锌组、配喂组、对照组、补锌组和高锌组,缺锌组、对照组、高锌组分别用缺锌饲料(Zn含量<1mg/kg),常锌饲料(Zn含量为50mg/kg)和高锌饲料(Zn含量为150mg/kg)喂养8周,补锌组用缺锌饲料喂养3周后改用高锌饲料喂养5周,配喂组用常锌饲料喂养,给料量按缺锌组前一天实际进食量添加。8周后处死,用极谱法测定血清中锌的含量,用放射免疫法测定血清中FT3、FT4的含量。结果缺锌使大鼠血清中锌含量显著降低,血清中FT3含量下降,补锌后恢复正常,缺锌对FT4无影响。结论缺锌引起甲状腺激素FT3下降,而FT4不受影响。     

Effect of Zinc Addition to Soil on Nematode Community Structure

No abstract available.     

锌对神经细胞增殖和分化作用的影响

目的探讨锌对神经细胞增殖和分化作用。方法NT2细胞在锌鳌合剂TPEN作用下,检测神经的凋亡情况,用MTT方法检测细胞的增殖活性．细胞的神经发育标志蛋白GFAP和NeuN的表达情况。结果随着TPEN浓度的增高,细胞核荧光强度越强,凋亡越强;细胞增殖活性越低,GFAP和NeuN蛋白表达越低。结论锌对神经细胞增殖和分化有较严重的抑制作用。     

富锌鹌鹑蛋对儿童血锌铜钙营养的影响

目的了解富锌鹌鹑蛋对儿童生长发育和血清锌铜钙和其他生化的影响。方法在幼儿园挑选７３名４～４５岁全托健康儿童,随机分为两组,实验组３７例、对照组３６例,两组在同一膳食基础上,用称重法记录食物摄入量,实验组每人每日吃鹌鹑蛋５枚。对照组每人每日服１０％硫酸锌１０ｍｌ。结果两组儿童体格发育比较,实验组身高、体重、上臂肌围和三角肌皮皱厚度较实验前明显增加（Ｐ＜００５）,对照组身高、上臂围和三角肌皮皱厚度较前明显增加（Ｐ＜００５）,两组间体重身高无明显差异（Ｐ＞００５）,上臂肌围和三角肌皱厚度增加有组间差异（Ｐ＜００５）。实验后对照组血红蛋白下降,血清铜、游离原卟啉上升与实验组有显著差异（Ｐ＜００５）,实验组血红蛋白、游离原卟啉、血清铜变化不大。结论富锌鹌鹑蛋有益于儿童生长发育,对铁和血红蛋白影响小,硫酸锌可能干扰铁的吸收,营养状况好的儿童不宜盲目补锌。     

Protective Effects of Zinc on Testes of Cadmium-Treated Rats

In this microscopic study, the toxic effects of cadmium (Cd) and the protective role of a zinc (Zn) co-treatment were investigated in the testes of the rats treated with Cd. At the dose and duration used, Cd severely damaged the seminiferous tubules and caused the degeneration and disintegration of spermatogenic cells. Leydig cells were also lost after Cd treatment. The present study showed that zinc co-treatment protected testes against toxic effects of cadmium.     

锌在豚鼠卡那霉素中毒性耳聋中的作用

应用给豚鼠注射硫酸锌的方法，观察了锌对豚鼠卡那霉素中毒性耳聋的影响。通过观察给药组和对照组动物的耳廊反射（ＰＲ）阈，脑干听觉诱发电位（ＢＡＥＰｓ）阈变化及耳蜗底回外毛细胞缺失率，发现硫酸锌注射组和对照组豚鼠的４、６、８ＫＨｚＰＲ阈在处死时分别升高１４．５６±３．１２ｄＢ，１５．８８±３．３８ｄＢ，１８．１２±２．７０ｄＢ和１７．１２±３．５６ｄＢ，１６．１５±２．５８ｄＢ，１９．２５±３．０１ｄＢ（Ｐ＞０．０５）。实验结果说明补充锌对卡那霉素中毒性耳损害无明显对抗作用     

锌对骨组织钙吸收及骨密度的影响

目的探讨锌在骨形成过程中对骨组织Ca吸收及骨密度的影响及其机理。方法首次应用自制浸没式一次通气旋转装置对16天孕龄小鼠肢芽器官进行体外培养,采用⁴⁵Ca示踪和钼钯X-ray乳腺机摄片技术分析骨形成的变化。结果锌缺乏组和补锌组Ⅲ(Zn²⁺浓度分别为120μmol/L)与对照组相比骨组织钙吸收减少,骨密度降低;补锌组Ⅰ、Ⅱ(Zn²⁺浓度分别为45μmol/L及70μmol/L)与对照组相比骨组织钙吸收增加,骨密度升高。结论适量补锌有潜在促进骨形成的作用,锌缺乏/过量抑制骨组织的发育与钙化过程。     

Assessment of structure and function in metal polluted grasslands using Terrestrial Model Ecosystems

Ecosystem effects of metal pollution in field situations are hard to predict, since metals occur often in mixtures and links between structural (organisms) and functional endpoints (ecosystem processes) are not always that clear. In grasslands, both structure and functioning was suspected to be affected by a mixture of copper, lead, and zinc. Therefore, the structural and functional variables were studied simultaneously using Terrestrial Model Ecosystems (TMEs). Comparing averages of low- and high-polluted soil, based on total metal concentrations, did not show differences in structural and functional variables. However, nematode community structure (Maturity Index) negatively correlated with metal concentrations. Next to that, multivariate statistics showed that enchytraeid, earthworm and, to lesser extent, nematode diversity decreased with increasing metal concentrations and a lower pH in the soil. Bacterial CFU and nematode biomass were positively related with decomposer activity and nitrate concentrations. Nitrate concentrations were negatively related to ammonium concentrations. Earthworm biomass, CO(2) production and plant yield were not related to metal concentrations. The most metal-sensitive endpoint was enchytraeid biomass. In all analyses, soil pH was a significant factor, indicating direct effects on organisms, or indicating indirect effects by influencing metal availability. In general, structural diversity seemed more positively related to functional endpoints than structural biomass. TMEs proved valuable tools to assess the structure and function in metal polluted field situations. The outcome feeds modeling effort and direct future research.     

定量超声在肌肉评估中的应用

肌肉是构成人体的重要组织,通过肌肉的收缩可以引导和控制身体的运动.目前可以通过肌电图学(Electromyography)、核磁共振成像(Magnetic Resonance Imaging)和超声成像的方法来评估肌肉功能.定量超声(Quantitative Ultrasound)可以提供有关肌肉结构的定量数据及其在收缩过程中的实时变化,正逐步成为一种可靠的研究和临床工具,在肌肉功能的评估中正扮演着越来越重要的角色.本文总结了定量超声在肌肉评估中的三个方面:肌肉功能性评估、人体运动分析和肌肉硬度(弹性)检测,并且讨论了当前定量超声在肌肉评估中的主要问题和困难.     

锌对致突变物诱发的CHO细胞突变的影响

<正> 人类食管癌的发病具有明显的地理环境倾向。对南非特兰斯开、伊朗北部及里海沿岸和我国华北太行山地区等食管癌高发区的研究表明,除当地土壤中缺锌外,居民的高谷物、低动物性食品的饮食结构也极易造成     

An Evaluation of Quantitative and Qualitative Assessment Techniques on the Impact of the SERR Curriculum

This study measured the effectiveness of a smoking risk reduction program for sixth grade students using a pretest/posttest control group design with the addition of a nonequivalent control group. Knowledge of the health consequences of smoking, decision-making, resistance-to-persuasion skills, and tobacco use were analyzed quantitatively; program implementation, participant views of the program, and program effects were analyzed qualitatively; and the quantitative data were analyzed in terms of its consistency with the qualitative data. Analysis of quantitative results revealed significant differences between groups on the smoking knowledge test, decision-making skills, and resistance-to-persuasion skills. Qualitative results not only substantiated quantitative results, but also revealed overall participant satisfaction with the program. They also indicated the need for a close working relationship between teachers, state and local health educators, reorganization of the curriculum, and relinquishing of curriculum to school districts for self-scheduling and organization. Utilization of both methods of analysis yielded a closer estimate of total program impact than if only method of analysis had been used.