Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin on trace elements, inflammation and viral clearance in the myocardium during coxsackievirus B3 infection in mice

A myocarditic coxsackievirus B3 (CB3) infection in adult male A/J mice was used to investigate the effects of 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) exposure on mortality and on inflammatory lesion, virus and trace element contents of the heart. The mice were injected with four weekly intraperitoneal (i.p.) injections of TCDD (a loading dose of 5 microg/kg followed by three maintenance doses of 1.4 microg/kg). To reach a steady-state body burden of TCDD the mice were allowed a 90-day recovery period before infection with CB3 virus. TCDD increased the infection-induced mortality rate, whereas in TCDD-exposed mice, heart lesions at day 7 after the virus inoculation (median value 0.67% of the tissue section area; interquartile range 0.28; not statistically significant) were one-third of that in non-exposed infected mice (2.07% of the tissue section area; interquartile range 3.06). The size of the inflammatory heart lesion correlated to the amount of virus (r(s) = 0.829, P < 0.01) as well as to the calcium (Ca: r(s) = 0.725, P < 0.01) and the magnesium (Mg: r(s) = -0.615, P < 0.05) contents. In TCDD-exposed mice in situ hybridisation of viral RNA in the myocardium at day 7 showed a tendency to decreased amounts of virus, as well as a less pronounced increase in myocardial Ca content, both supporting a milder myocardial disease after TCDD exposure. No effect of TCDD exposure was seen on the zinc (Zn) or selenium (Se) levels in the myocardium. In conclusion, although TCDD seemed to have a limiting effect on viral replication and the development of the inflammatory lesion in the myocardium, mortality was increased by TCDD in this infection model. However, TCDD had no significant effects on the selected trace elements that could be of importance for the severity of the inflammatory lesion (Ca, Se), for the local host response activation (Zn) or for the development of myocardial disease complications (Mg). Accordingly, the increased mortality may be a result of an infection-induced increase in TCDD toxicity to vital organs other than the heart, and/or a TCDD-induced change in the tissue affinity and virulence of the virus, possibly causing involvement of other target organs in the infectious process and changed pathogenesis.     

A Pb isotope and trace element study of rainwater from the Massif Central (France)

Lead isotope ratios and Zn, Pb, Cu, Cd, Sb and Rb contents were measured in samples of rainwater collected over a period of 15 months from the Massif Central (France). Each sample, collected automatically at monthly intervals, represents a series of rainfall events. Rainwater chemistry was interpreted in terms of the chemical contributions from wet deposition and from different source regions for dust in the centre of France. Trace element concentrations in rainwater samples showed a wide range, particularly for Pb (1.30-465 microg/l), with variations decreasing for Cd (0.07-1.70 microg/l), Zn (1.00-54.00 microg/l), Cu (0.20-25.00 microg/l), Sb (approximately 0-0.33 microg/l) and Ni (approximately 0-15.00 microg/l). Trace element contents do not correlate with rainfall amount and no inter-element correlations are evident in the data. Lead is the most common trace metal found in the rainwater (mean value = 996 microg/m2/y) while Sb is the least common element measured (mean value = 1.12 microg/m2/y). The composition of rainwater collected from the Massif Central shows a range in Pb isotope ratios from 17.935 to 19.22 (206Pb/204Pb), 15.578 to 15.73 (207Pb/204Pb) and 37.559 to 38.606 (208Pb/204Pb). A five-component mixing model involving contributions from the natural background, gasoline inputs from industrial and agricultural activity and a source resulting from mining waste may be used to explain both the Pb isotope signature and the fluctuations in trace metal contents of Massif Central rainwater.     

Effects of coxsackievirus B3 infection on the acute-phase protein metallothionein and on cytochrome P-4501A1 involved in the detoxification processes of TCDD in the mouse

During acute infections, the synthesis of acute-phase proteins and other proteins participating in the host defence are stimulated in the liver and kidney. In previous studies of coxsackievirus B3 (CB3) infection in mice, we found that cadmium (Cd) accumulates in the kidney, whereas 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) accumulates in the liver. To study if CB3 infection affects the synthesis of the Cd-binding protein metallothionein (MT) and the TCDD-binding/detoxifying cytochrome P-450 (CYP-450) isozyme CYP1A1, the basal and TCDD-induced levels of serum MT and liver CYP1A1 isozyme were determined in healthy and CB3-infected A/J mice. Furthermore, because interferons affect CYP450 activity, the serum levels of the interferons alpha (IFN-alpha) and -beta (IFN-beta) were measured in CB3-infected mice and in mice treated with the interferon-inducer polyinosinic/polycytidylic acid (poly I/C). Virus or poly I/C was administered intraperitoneally (i.p.) on day 0 and 500 ng TCDD/kg bodyweight on day 1. On day 4, CB3 infection had induced MT approximately 10-fold, regardless of TCDD treatment (P < 0.01 in infected mice and P < 0.001 in infected, TCDD-treated mice). TCDD alone induced a 10-fold increase in CYP1A1 activity (P < 0.001), whereas infection alone suppressed the normal CYP1A1 activity by 75% (P < 0.001). Infection also suppressed the TCDD-induced CYP1A1 activity by approximately 30% (n.s.). Poly I/C suppressed CYP1A1 by 20-25% (n.s.) at both basal and TCDD-induced levels. Serum IFN-alpha and IFN-beta levels were undetectable in controls, in TCDD-treated and in the poly I/C-treated groups on day 4, probably because the short IFN peak is detectable only hours after injection. Conversely, on day 4 of the infection, IFN-alpha and IFN-beta were consistently raised in the TCDD-treated infected mice, whereas increased IFNs as a result of infection alone could be detected in only one individual. These results suggest that the normal host responses during acute infections down-regulate detoxifying processes in favour of acute-phase protein synthesis. This may explain the observed changed pattern of accumulation, excretion and toxicity of the environmental pollutants cadmium and TCDD during this common virus infection.     

我国塔式起重机行业发展历程(三)

4　 8 0年代80年代是我国塔机行业深化发展的十年。由于改革开放 ,城市建设规模扩大 ,建筑任务繁重 ,对塔机需求倍增。因而塔机年产量大幅度上扬 ,除个别年份外 ,历年产量均接近或超越千台 ,见表 5。表 5　我国 80年代塔机产量表 (台 )　年度 19811982 1983 19841985 19861987198819891990产量 70 0 698893 12 78111612 5 0 13 3 14 12 18610 2 5　　 80年代塔机行业的主要特点是由国外引进产品专利技术 :1 984年由法国POTAIN引进技术的产品型号是QTMR/ 36 0B、FO/ 2 3B、H3/ 36B ,1 986年由德国LIEBHERR引进的型号是 1 32HC。引…     

Lichen (Xanthoria parietina) biomonitoring of trace element contamination and air quality assessment in Pisa Province (Tuscany, Italy)

In the northern part of Pisa Province (Tuscany, Italy), the use of lichens as both airborne trace element biomonitors and air quality bioindicators is described. The following elements were analysed in Xanthoria parietina: As, Cd, Cr, Ni, Pb, V, Zn and Hg, and the results are compared with those we previously obtained in Livorno Province (Tuscany) using the same lichen species. The results identify spots of different environmental metal contamination and air quality. Median values of Pb, V and Ni concentrations were much lower than those of Livorno Province, with maximum values even nine times lower. Arsenic contamination was also lower, while Cd, Hg and Zn levels were similar in the two areas. In Pisa Province, the highest levels of contamination were recorded for Zn, Pb, Cr and Ni, and a degree of agreement was found between air quality and metal concentrations in lichens. The air quality in Pisa Province is better than in Livorno Province, even if the different climatic and orographic features of the two areas may influence the presence of lichen species and thus an assessment of air quality.     

热平衡是企业节能的基础(三)(真空挤出机成型、自然干燥、一座轮窑和一座隧道窑砖瓦混烧的热平衡)

能源平衡测试(通常简称热平衡). 本文以2条真空挤出机成型生产线、自然干燥、1座轮窑和1座隧道窑砖瓦混烧生产工艺生产红平瓦.通过对企业能源平衡测试结果的数据分析,对砖瓦企业不同生产工艺的能源利用率、轮窑、隧道窑的热效率、砖瓦企业机电效率、油利用率及不同工艺环节电能消耗的比例、能量在企业的流向、单位产量能耗、有效能、能源构成、热效率、电效率、电能损耗等几方面进行介绍,为砖瓦企业在循环经济模式中节省能源,减少排放,达到物质、能量利用最大化、废弃物排放最小化的目的提供科学依据.     

Possible interaction between a rodenticide treatment and a pathogen in common vole (Microtus arvalis) during a population peak

A common vole (Microtus arvalis) population peak in Northern Spain in 2007 was treated with large scale application of chlorophacinone, an anticoagulant rodenticide of the indandione family. Voles found dead and trapped alive were collected in treated and untreated areas. Residues of chlorophacinone were analyzed in liver of voles by HPLC-UV. Also, the presence of the pathogen Francisella tularensis was analyzed by PCR in samples of vole spleen. Chlorophacinone (82-3800 ng/g; wet weight liver) was only detected in voles found dead in treated areas (55.5%). The prevalence of F. tularensis in voles found dead in treated areas was also particularly high (66.7%). Moreover, chlorophacinone levels were lower in voles that were PCR-positive for F. tularensis (geometric mean [95% CI], 418 [143-1219] ng/g) than in those that were PCR-negative (1084 [581-2121] ng/g). Interactions between pathogens and rodenticides might be considered to reduce the doses used in baits or to avoid the use of the more toxic 2nd generation anticoagulant rodenticides.     

慢性应激对小鼠空间学习记忆的影响及脑内Wnt3a的表达

目的:研究慢性应激对小鼠空间学习记忆的影响及机制。方法 :慢性应激模型的建立采用的是持续21天的7种不同应激方式,通过Morris水迷宫实验检测小鼠的空间学习记忆能力,免疫组织化学方法检验小鼠脑内各脑区wnt3a的表达。结果:慢性应激组小鼠与对照组小鼠相比,在定位航行试验中,小鼠寻找平台的逃避潜伏期明显提高(P<0.05),空间搜索实验中,应激组小鼠在目标象限的游泳时间明显减少(P<0.05)。在小鼠脑内PFC区wnt3a表达显著减少(P<0.01)。结论 :慢性应激对小鼠空间学习记忆的能力具有损伤作用,这与wnt3a在脑内的表达关系密切。     

Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate element (CS-MIN3)

Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Many homogenization models for corrugated panels of different shapes have been proposed. However, there is a lack of investigations for verifying their accuracy and reliability. In addition, in the recent trend of development of smoothed finite element methods, the cell-based smoothed three-node Mindlin plate element (CS-MIN3) based on the first-order shear deformation theory (FSDT) has been proposed and successfully applied to many analyses of plate and shell structures. Thus, this paper further extends the CS-MIN3 by integrating itself with homogenization models to give homogenization methods. In these methods, the equivalent extensional, bending, and transverse shear stiffness components which constitute the equivalent orthotropic plate models are represented in explicit analytical expressions. Using the results of ANSYS and ABAQUS shell simulations as references, some numerical examples are conducted to verify the accuracy and reliability of the homogenization methods for static analyses of trapezoidally and sinusoidally corrugated panels.     

Regulation of human neutrophil type 3 complement receptor (iC3b receptor) expression during phagocytosis of Staphylococcus aureus and Escherichia coli

Human neutrophils (PMN) express a receptor for iC3b, a cleavage product of C3b. CR3 is an important receptor for phagocytosis of opsonized bacteria and its expression is enhanced by cell activation. We examined PMN CR3 expression during phagocytosis using flow cytometry and a CR3-specific monoclonal antibody. After 30 min phagocytosis of opsonized S. aureus and E. coli, CR3 expression increased to 151% and 221% of controls, respectively. Unopsonized S. aureus had no effect on CR3; however, unopsonized E. coli enhanced CR3 expression despite not being phagocytosed. Time-kinetic studies indicated a rapid initial fall in CR3 after addition of bacteria to PMN, followed by enhanced expression within 5-10 min. The initial fall in CR3 probably represented CR3 internalization rather than receptor destruction, as superoxide dismutase, catalase and protease inhibitors had no effect on this. Correlation of CR3 expression with the PMN oxidative response, measured with the intracellular fluorescent probe DCF-DA, demonstrated a dichotomy. Opsonized S. aureus and E. coli caused an oxidative response from PMN but unopsonized E. coli, which caused significant CR3 up-regulation, did not. CR3 up-regulation with unopsonized and opsonized E. coli was markedly inhibited by Polymyxin B, suggesting a role for endotoxin. These experiments indicate that CR3 expression can be regulated during phagocytosis, and the mechanisms responsible are distinct from those involved in the oxidative burst. CR3 up-regulation following exposure to bacteria in vivo may enhance neutrophil function at sites of infection.     

Fate of nine recycled water trace organic contaminants and metal(loid)s during managed aquifer recharge into a anaerobic aquifer: Column studies

Water quality changes associated with the passage of aerobic reverse osmosis (RO) treated recycled water through a deep anaerobic pyritic aquifer system was evaluated in sediment-filled laboratory columns as part of a managed aquifer recharge (MAR) strategy. The fate of nine recycled water trace organic compounds along with potential negative water quality changes such as the release of metal(loid)s were investigated in large-scale columns over a period of 12 months.The anaerobic geochemical conditions provided a suitable environment for denitrification, and rapid (half-life <1-25 days) degradation of the endocrine disrupting compounds (bisphenol A, 17β-estradiol, 17α-ethynylestradiol), and iodipamide. However, pharmaceuticals (carbamazepine and oxazepam), disinfection by-products (N-nitrosodimethylamine, N-nitrosomorpholine) and iohexol did not degrade rapidly (half-life > 100 days).High retardation coefficients (R) determined for many of the trace organics (R 13 to 67) would increase aquifer residence time and be beneficial for many of the slow degrading compounds. However, for the trace organics with low R values (1.1-2.6) and slow degradation rates (half-life > 100 days), such as N-nitrosodimethylamine, N-nitrosomorpholine and iohexol, substantial biodegradation during aquifer passage may not occur and additional investigations are required.Only minor transient increases in some metal(loid) concentrations were observed, as a result of either pyrite oxidation, mineral dissolution or pH induced metal desorption, followed by metal re-sorption downgradient in the oxygen depleted zone.     

CD5 (Ly-1)-negative,conventional splenic B cells make a substantial contribution to the bromelain plaque-forming cell response in CBA and BW mice

CD5 (Ly-1) B cells are a minor subpopulation in mouse spleen and are thought to be responsible for the production of natural autoantibodies to bromelain-treated autologous erythrocytes (Br-RBC). Here it is shown that substantial numbers of conventional, CD5-negative, splenic B cells also secrete these antibodies in CBA and (NZB x NZW)F1 mice, whereas in NZB and BALB/c mice they are all produced by the CD5 B-cell population. However, stimulation with bacterial lipopolysaccharide in vivo preferentially activates the CD5 B-cell group to anti-Br-RBC antibody secretion.     

Human placenta as a 'dual' biomarker for monitoring fetal and maternal environment with special reference to potentially toxic trace elements. Part 2: essential minor, trace and other (non-essential) elements in human placenta.

A survey of elemental composition of the human placenta was undertaken to evaluate reference values for minor and trace elements (essential and non-essential). The new data collection was narrowed down to results generated between the period of 1975-2000, since analytical methodology was becoming increasingly reliable with time for many elements. The search revealed the following results (microg/g, based on wet weight): Ca = 770; Cl = 1900; K = 1685; Mg = 100; Na = 360; P = 1700; and S = 350. However, Na, P and S need further confirmation. For a group of essential trace elements following average values were evaluated (microg/g, based on wet weight): Co = 0.007; Cr = 0.03; Cu = 0.9; Fe = 69; I = 0.005; Mn = 0.08; Mo = 0.02; Se = 0.2; and Zn = 10. However, the iodine value needs further confirmation. In addition, information values have been identified for a number of so-called non-essential elements such as Ag, Au, B, Ba, Br, Cs, F, La, Rb, Sb, Sc, Si, Sn, Sr, Ti, V and W. The survey results for toxic trace elements As, Cd, Hg, Ni and Pb are discussed in part 3 of this paper along with placenta as a biomonitor for toxic trace elements.     

Contrast and transferability of parameters of lumped water balance models in the Segura River Basin (Spain)

Knowing the water resources in a river basin is a key aspect to appropriate water planning, and they can be estimated by lumped water balance models. The possibility to transfer the calibrated parameters of a contrasted model to non‐gauged ones improves this knowledge with no need for direct measurements. This work studies the transferability of the parameters of the lumped models in five catchments in the southeast of Spain, testing the influence of the snow and the effect of serial autocorrelation in the goodness of fit. The results are also compared with those of the distributed model of reference in Spain (SIMPA). As principal results, the abcd model is the selected one, the snow effect is negligible, the transferability of parameters for this case is not totally possible, and serial autocorrelation must be included for this kind of modelling.     

Elastic modulus of a rock mass based on the two parameter negative-exponential (TPNE) distribution of discontinuity spacing and trace length

The frequency, spacing and trace length of rock mass discontinuities appear to follow a negative exponential distribution. However, in some cases this distribution has limitations. To overcome this, it is necessary to choose a target distribution which is flexible enough to simulate the spacing and trace length of the discontinuities. The paper shows how the two parameter negative exponential (TPNE) distributions can meet the requirements. An improved constitutive equation of rock mass based on this new distribution has been determined from which a new method to calculate rock mass elastic modulus (Em) is proposed, taking into account the rock mass anisotropy. It was found that the geo-stresses influence Em in two ways: it varies with changes in the orientation of the geo-stress and with the size of geo-stress. The work is illustrated by a case study on the abutment slope of the 295 m high arched dam of the Xiao wan hydroelectric power station in Yunnan province, Southwest of China.     

Hepatic and renal concentrations of 10 trace elements in crocodiles (Crocodylus niloticus) in the Kafue and Luangwa rivers in Zambia

Hepatic and renal concentrations of the elements arsenic, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium and zinc were determined in samples collected from four crocodiles from the Kafue River, Kafue National Park and five crocodiles from the Luangwa River, Luangwa National Park, Zambia. The concentrations of the essential elements were similar to those reported in other vertebrates. Arsenic and cadmium concentrations were low (medians below 0.05 microg As/g and below 0.16 microg Cd/g, wet wt.). Mercury and lead concentrations were several orders of magnitude higher (medians up to 3.7 microg Hg/g, and up to 8.7 microg Pb/g, all wet wt.) than in hippopotami from the same rivers, probably as a result of food-chain biomagnification. Judging by the results obtained in this study, pollution from the mining activity around the Kafue River drainage area in the Copperbelt region has not significantly influenced the trace element concentrations in tissues of the crocodiles in the Kafue National Park. The trace element concentrations measured may serve as reference values in future studies on crocodilians.     

The uptake from fresh water and subsequent clearance of a vanadium burden by the common eel (Anguilla anguilla)

The uptake of ⁴⁸V vanadium from a solution of 10^?5M⁴⁸V-orthovanadate by freshwater elvers and the subsequent depletion of the vanadium burden was studied. At the end of the 8-week loading period, the levels of ⁴⁸V were still increasing in the liver, kidney, bone and carcase. The uptake rate for the whole fish over the 8-week period was 760 pg atom/h/100 g body wt and the depletion rate over the following 5 weeks in clean water was about one tenth of this. Liver contained the highest amount of ⁴⁸V at the end of the 8-week loading period, calculated as equivalent to 1.1 × 10⁴ g atom V/kg wet wt, and this level was unchanged at the end of the 5-week depletion period. Less than 1% of the carcase ⁴⁸V was present in the fraction of MW under 2000.     

Removal of pharmaceuticals and kinetics of mineralization by O(3)/H(2)O(2) in a biotreated municipal wastewater

The ozonation of an effluent from the secondary clarifier of two Municipal Wastewater Treatment Plants was performed by using alkaline ozone and a combination of ozone and hydrogen peroxide. Alkaline ozonation achieved only a moderate degree of mineralization, essentially concentrated during the first few minutes; but the addition of hydrogen peroxide eventually led to a complete mineralization. The evolution of total organic carbon (TOC) as a measure of the extent of mineralization and the concentration of dissolved ozone were analyzed and linked in a kinetic model whose parameter represented the product of the exposure to hydroxyl radicals and the kinetic constant of indirect ozonation. This rate parameter yielded the highest values during the first part of O(3)/H(2)O(2) runs. The kinetic constant for the decomposition of ozone at the end of the run was also measured and computed for the non-oxidizable water matrix and yielded essentially the same values regardless of whether or not hydrogen peroxide was used. A group of 33 organic compounds, mainly pharmaceuticals and some relevant metabolites present in the wastewater effluents, were evaluated before and after the ozonation process using a liquid chromatography-hybrid triple-quadrupole linear ion trap system (LC-QqLIT-MS). The results demonstrate that the ozonation degrades these compounds with efficiencies of over 99% in most cases, even under low mineralization conditions in alkaline ozonation.