Heavy-Metal Phytostabilizing Potential of Agrostis castellana Boiss. & Reuter

The soils of many abandoned mine sites in the central region of Spain are heavily polluted with a number of different metals. Having frequently found Agrostis castellana growing at these old mine sites, this study was designed to assess its remediation capacity for this type of setting. In an initial field study, plant specimens were collected from 4 abandoned mine sites to determine pollutant concentrations in their roots and shoots. This was followed by a 4-year bioassay in a controlled environment in which soils collected from the mines were used to set up microcosms. Maximum root concentrations of the most polluting elements present in the bioassay were 3625 mg kg(-1) Zn, 2793 mg kg(-1) Cu, 13042 mg kg(-1) Pb, 49 mg kg(-1) Cd and 957 mg kg(-1) As. These concentrations represent root bioaccumulation indices of over 1 and usually >2. In contrast, indices of transfer to above-ground phytomass were always < 1, indicating this species is a good candidate for use as a phytostabilizer. However, the high metal concentrations that could reach the above-ground mass of this plant determines a need for close monitoring and avoiding the use of areas under restoration for hunting or grazing.

Bullet on bullet fragmentation profile in soils

Lead-antimony alloy slugs encased in a brass jackets are common small arms caliber ammunition used for training and target practice. When small caliber ammunition is fired at testing and training ranges, these metals--some of which are toxic--are introduced into the environment. Research was conducted on the effects of bullet on bullet impacts and the resulting bullet fragmentation. The extent of bullet fragmentation, among other factors, affects the formation of mobile metal species from small arms firing ranges. Bullet on bullet impact can increase the surface area to mass ratio of the bullet metal alloys in the soil. The solubility of a metal is typically associated with the specific corrosion rate in the berm environment which is dependent on the surface area of the fragments. The purpose of the study was to analyze the bullet on bullet impact effects in six soil types. Changes in the metal distribution as a result of bullet impact was evaluated through sieve analysis and changes in the particle size distribution. The bullet on bullet impact observed in this study demonstrated a significant and observable shift in the fragmentation profiles for the lead, antimony, and copper in soils after shooting an average of 1050 tungsten-nylon bullets into the legacy lead soils. This study provides new information to assist with determining the potential environmental fate, transport, and environmental availability associated with constant bullet on bullet impact at testing and training ranges.

Transformation of heavy metal fractions on soil urease and nitrate reductase activities in copper and selenium co-contaminated soil

This study aims to explore the effects of the distribution, transformation and bioavailability of different fractions of copper (Cu) and selenium (Se) in co-contaminated soils on soil enzymes, providing references for the phytoremediation of contaminated areas and agriculture environmental protection. Pot experiments and laboratory analysis were used to investigate the transformation and bioavailability of additional Cu and Se for pakchoi (Brassica chinensis) in co-contaminated soil. In the uncontaminated soil, Cu mainly existed in residual form, whereas Se was present in residual form and in elemental and organic-sulfide matter-bound form. In the contaminated soil, Cu mainly bound to Fe-Mn oxidates, whereas Se was in exchangeable and carbonates forms. After a month of pakchoi growth, Cu tended to transfer into organic matter-bound fractions, whereas Se tended to bound to Fe-Mn oxidates. The IR (reduced partition index) value of Cu decreased as the concentrations of Cu and Se gradually increased, whereas the IR value of Se decreased as the concentration of Se increased. The IR value before pakchoi planting and after it was harvested was not affected by the concentration of exogenous Cu. Soil urease and nitrate reductase activities were inhibited by Cu and Se pollution either individually or combined in different degrees, following the order nitrate reductase>urease. The significant correlation between the IR value and soil enzyme activities suggests that this value could be used to evaluate the bioavailability of heavy metals in soil. Path analysis showed that the variations in exchangeable Cu and organic-sulfide matter-bound and elemental Se had direct effects on the activities of the two enzymes, suggesting their high bioavailability. Therefore, the IR value and the transformation of metals in soil could be used as indicators in evaluating the bioavailability of heavy metals.

Fate of copper complexes in hydrothermally altered deep-sea sediments from the Central Indian Ocean Basin

The current study aims to understand the speciation and fate of Cu complexes in hydrothermally altered sediments from the Central Indian Ocean Basin and assess the probable impacts of deep-sea mining on speciation of Cu complexes and assess the Cu flux from this sediment to the water column in this area. This study suggests that most of the Cu was strongly associated with different binding sites in Fe-oxide phases of the hydrothermally altered sediments with stabilities higher than that of Cu-EDTA complexes. The speciation of Cu indicates that hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may not significantly contribute to the global Cu flux. However, increasing lability of Cu-sediment complexes with increasing depth of sediment may increase bioavailability and Cu flux to the global ocean during deep-sea mining.

Effects of Cu exposure on enzyme activities and selection for microbial tolerances during swine-manure composting

A simulated experiment of aerobic composting was conducted on swine manure to evaluate the effects of Cu at two exposure levels (200 and 2000 mg kg(-1), corresponding to low-Cu and high-Cu treatments, respectively) on the activity of microorganisms. In addition, the microbial pollution-induced community tolerance (PICT) to Cu and co-tolerance to selected antibiotics (tylosin and vancomycin) in the composted products were also investigated using the Biolog Ecoplates™ method. It was demonstrated that the enzymatic activities were significantly inhibited by the high-Cu treatment, with maximal inhibition rates of 56.8% and 65.1% for urease and dehydrogenase, respectively. In response to the PICT test, the IC50 (half-maximal inhibition concentrations) values on the microorganisms in the high-Cu-treated composts were clearly higher than those in the low-Cu-treated and control composts, for the toxicity tests on both Cu and antibiotics, including tylosin and vancomycin. The data demonstrated that high-Cu exposure to the microbial community during the composting not only selected for Cu resistance but also co-selected for antibiotic resistance, which was of significance because the tolerance might be transferred to the soil after the land application of composted manure.

Time-dependent effects of waterborne copper exposure influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta and their mechanism

The present study was conducted to determine the time-course of waterborne chronic copper (Cu) exposure effects influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta and their mechanisms. S. hasta were exposed to four waterborne Cu concentrations (2 (control), 18, 38 and 55 μg Cu/l) for 60 days. Sampling occurred on day 30 and day 60, respectively. Survival decreased and hepatic Cu content increased with increasing Cu levels. On day 30, Cu exposure increased hepatic lipid content, viscerosomatic index (VSI) and hepatosomatic index (HSI), and activities of lipogenic enzymes (6PGD, G6PD, ME, ICDH and FAS) as well as the mRNA levels of 6PGD, G6PD, ME, FAS, ACCα, LPL, PPARγ and SREBP-1 in the liver. However, the mRNA levels of ATGL, HSL and PPARα declined following Cu exposure. On day 60, Cu exposure reduced hepatic lipid content, HSI, VSI, activities of G6PD, ME, ICDH and FAS, and the mRNA expression of 6PGD, G6PD, ME, FAS and SREBP-1, but increased mRNA expression of CPT 1, HSL and PPARα. The differential Pearson correlation between transcriptional changes of genes encoding transcription factors (PPARα, PPARγ and SREBP-1), and the activities and mRNA expression of enzymes involved in lipogenesis and lipolysis were observed on day 30 and day 60, respectively. Cu exposure for 30 days induced hepatic lipid accumulation by stimulating lipogenesis and inhibiting lipolysis. However, 60-day Cu exposure reduced hepatic lipid content by inhibiting lipogenesis and stimulating lipolysis. To our knowledge, for the first time, the present study provided experimental evidence that waterborne chronic Cu exposure differentially influenced genes involved in lipogenic and lipolytic metabolic pathway and the enzymes encoded in a duration-dependent manner in fish, and provided new insight into the relationship between metal toxicity and lipid metabolism.

A rhodamine-based fluorescent probe for Cu(II) determination in aqueous solution

An 'off-on' rhodamine-based fluorescence probe for the selective detection of Cu(II) has been designed, exploiting the guest-induced structure transform mechanism. This system shows a sharp Cu(II)-selective fluorescence enhancement response in an aqueous system under physiological pH, and possesses high selectivity against a background of environmentally and biologically relevant metal ions. Under optimum conditions, the fluorescence intensity enhancement of this system is linearly proportional to the Cu(II) concentration from 50 nM to 6.0 μM with a detection limit of 29 nM.

Antioxidant and Metal Chelation-Based Therapies in the Treatment of Prion Disease

Many neurodegenerative disorders involve the accumulation of multimeric assemblies and amyloid derived from misfolded conformers of constitutively expressed proteins. In addition, the brains of patients and experimental animals afflicted with prion disease display evidence of heightened oxidative stress and damage, as well as disturbances to transition metal homeostasis. Utilising a variety of disease model paradigms, many laboratories have demonstrated that copper can act as a cofactor in the antioxidant activity displayed by the prion protein while manganese has been implicated in the generation and stabilisation of disease-associated conformers. This and other evidence has led several groups to test dietary and chelation therapy-based regimens to manipulate brain metal concentrations in attempts to influence the progression of prion disease in experimental mice. Results have been inconsistent. This review examines published data on transition metal dyshomeostasis, free radical generation and subsequent oxidative damage in the pathogenesis of prion disease. It also comments on the efficacy of trialed therapeutics chosen to combat such deleterious changes.

Non-destructive analysis of the conformational differences among feedstock sources and their corresponding co-products from bioethanol production with molecular spectroscopy

The objective of this study was to determine the possibility of using molecular spectroscopy with multivariate technique as a fast method to detect the source effects among original feedstock sources of wheat and their corresponding co-products, wheat DDGS, from bioethanol production. Different sources of the bioethanol feedstock and their corresponding bioethanol co-products, three samples per source, were collected from the same newly-built bioethanol plant with current bioethanol processing technology. Multivariate molecular spectral analyses were carried out using agglomerative hierarchical cluster analysis (AHCA) and principal component analysis (PCA). The molecular spectral data of different feedstock sources and their corresponding co-products were compared at four different regions of ca. 1800-1725 cm(-1) (carbonyl CO ester, mainly related to lipid structure conformation), ca. 1725-1482 cm(-1) (amide I and amide II region mainly related to protein structure conformation), ca. 1482-1180 cm(-1) (mainly associated with structural carbohydrate) and ca. 1180-800 cm(-1) (mainly related to carbohydrates) in complex plant-based system. The results showed that the molecular spectroscopy with multivariate technique could reveal the structural differences among the bioethanol feedstock sources and among their corresponding co-products. The AHCA and PCA analyses were able to distinguish the molecular structure differences associated with chemical functional groups among the different sources of the feedstock and their corresponding co-products. The molecular spectral differences indicated the differences in functional, biomolecular and biopolymer groups which were confirmed by wet chemical analysis. These biomolecular and biopolymer structural differences were associated with chemical and nutrient profiles and nutrient utilization and availability. Molecular spectral analyses had the potential to identify molecular structure difference among bioethanol feedstock sources and their corresponding co-products.

Current understanding on ethylene signaling in plants: the influence of nutrient availability

The plant hormone ethylene is involved in many physiological processes, including plant growth, development and senescence. Ethylene also plays a pivotal role in plant response or adaptation under biotic and abiotic stress conditions. In plants, ethylene production often enhances the tolerance to sub-optimal environmental conditions. This role is particularly important from both ecological and agricultural point of views. Among the abiotic stresses, the role of ethylene in plants under nutrient stress conditions has not been completely investigated. In literature few reports are available on the interaction among ethylene and macro- or micro-nutrients. However, the published works clearly demonstrated that several mineral nutrients largely affect ethylene biosynthesis and perception with a strong influence on plant physiology. The aim of this review is to revisit the old findings and recent advances of knowledge regarding the sub-optimal nutrient conditions on the effect of ethylene biosynthesis and perception in plants. The effect of deficiency or excess of the single macronutrient or micronutrient on the ethylene pathway and plant responses are reviewed and discussed. The synergistic and antagonist effect of the different mineral nutrients on ethylene plant responses is critically analyzed. Moreover, this review highlights the status of information between nutritional stresses and plant response, emphasizing the topics that should be further investigated.

Pro-inflammatory effects and oxidative stress in lung macrophages and epithelial cells induced by ambient particulate matter

The objective of this study was to compare the toxicological effects of different source-related ambient PM10 samples in regard to their chemical composition. In this context we investigated airborne PM from different sites in Aachen, Germany. For the toxicological investigation human alveolar epithelial cells (A549) and murine macrophages (RAW264.7) were exposed from 0 to 96 h to increasing PM concentrations (0-100 μg/ml) followed by analyses of cell viability, pro-inflammatory and oxidative stress responses. The chemical analysis of these particles indicated the presence of 21 elements, water-soluble ions and PAHs. The toxicological investigations of the PM10 samples demonstrated a concentration- and time-dependent decrease in cell viability and an increase in pro-inflammatory and oxidative stress markers.

Phytoremediation potential of Brassica juncea in Cu-pyrene co-contaminated soil: comparing freshly spiked soil with aged soil

A comparison was made between the dissipation of pyrene as well as the uptake of copper (Cu) in soil freshly spiked with Cu, pyrene or Cu + pyrene and in aged soil. The potential of B juncea for phytoremediation was also investigated. The biomass of Brassica juncea significantly decreased (>50% reduction) in freshly spiked soil when compared to aged soil in all treatments. However, the accumulation of Cu in shoot was significantly reduced (60-88%) in aged soil after 60 days of planting. The total removal of Cu from co-contaminated soil was always higher (>2-3 fold) in aged soil than in freshly spiked soil when lower Cu concentration (50 mg kg(-1)) was co-contaminated with 250 or 500 mg kg(-1) of pyrene while in other co-contaminated treatments, the total removal of Cu from aged soil were significantly lower. The level of pyrene in both planted and un-planted freshly spiked soil decreased significantly (>67%) over the 60 days of plant trial. In aged soils, there were no significant differences in residual pyrene concentration between planted and unplanted soil. This suggests that the presence of B. juncea in aged soil did not enhance the dissipation of pyrene and that the prediction of pyrene dissipation in laboratory prepared soil may not have reflected the true situation in the fields.

Nanotechnology as a therapeutic tool to combat microbial resistance

Use of nanoparticles is among the most promising strategies to overcome microbial drug resistance. This review article consists of three parts. The first part discusses the epidemiology of microbial drug resistance. The second part describes mechanisms of drug resistance used by microbes. The third part explains how nanoparticles can overcome this resistance, including the following: Nitric oxide-releasing nanoparticles (NO NPs), chitosan-containing nanoparticles (chitosan NPs), and metal-containing nanoparticles all use multiple mechanisms simultaneously to combat microbes, thereby making development of resistance to these nanoparticles unlikely. Packaging multiple antimicrobial agents within the same nanoparticle also makes development of resistance unlikely. Nanoparticles can overcome existing drug resistance mechanisms, including decreased uptake and increased efflux of drug from the microbial cell, biofilm formation, and intracellular bacteria. Finally, nanoparticles can target antimicrobial agents to the site of infection, so that higher doses of drug are given at the infected site, thereby overcoming resistance.

Nanotechnology as a therapeutic tool to combat microbial resistance

Use of nanoparticles is among the most promising strategies to overcome microbial drug resistance. This review article consists of three parts. The first part discusses the epidemiology of microbial drug resistance. The second part describes mechanisms of drug resistance used by microbes. The third part explains how nanoparticles can overcome this resistance, including the following: Nitric oxide-releasing nanoparticles (NO NPs), chitosan-containing nanoparticles (chitosan NPs), and metal-containing nanoparticles all use multiple mechanisms simultaneously to combat microbes, thereby making development of resistance to these nanoparticles unlikely. Packaging multiple antimicrobial agents within the same nanoparticle also makes development of resistance unlikely. Nanoparticles can overcome existing drug resistance mechanisms, including decreased uptake and increased efflux of drug from the microbial cell, biofilm formation, and intracellular bacteria. Finally, nanoparticles can target antimicrobial agents to the site of infection, so that higher doses of drug are given at the infected site, thereby overcoming resistance.

Copper chelation and exogenous copper affect circadian clock phase resetting in the suprachiasmatic nucleus in vitro

Light stimulates specialized retinal ganglion cells to release glutamate (Glu) onto circadian clock neurons of the suprachiasmatic nucleus (SCN). Glu resets the phase of the SCN circadian clock by activating N-methyl-d-aspartate receptors (NMDAR) causing either delays or advances in the clock phase, depending on early- or late-night stimulation, respectively. In addition, these Glu-induced phase shifts require tropomyosin receptor kinase B (TrkB) receptor activity. Previous studies show that copper (Cu) released at hippocampal synapses can inhibit NMDAR activity, and application of exogenous Cu likewise inhibits NMDAR activity. We investigated the effects of Cu in acute SCN brain slices prepared from C57BL/6Nhsd adult, male mice using treatments that decrease or increase available Cu levels in vitro and recorded neuronal activity on the following day. When bath-applied for 10 min at zeitgeber time (ZT) 16 (where ZT0=lights-on in the donor animal colony), the Cu-specific chelators tetrathiomolybdate (TTM) and bathocuproine disulfonate each induce ∼2.5-3-h phase delays in circadian neuronal activity rhythms, similarly to Glu-induced phase delays. Co-application of 10 μM CuCl2, but not 10 μM CoCl₂ blocks TTM-induced phase delays. Furthermore, TTM causes phase advances when applied at ZT23. At both application times, TTM-induced phase shifts are blocked by NMDA or TrkB receptor antagonists. Surprisingly, bath-application of 10 μM Cu alone also induces phase shifts in analogous experiments at ZT16 and ZT23. Inhibiting NMDAR does not block Cu-induced phase shifts. TrkB inhibition blocks Cu-induced phase delays but not phase advances. Thus, increasing and decreasing Cu availability appear to shift the SCN clock phase through different mechanisms, at least at the receptor level. We propose that Cu plays a role in the SCN circadian clock by modulating Glu signaling.

Remediation of metal polluted hotspot areas through enhanced soil washing--evaluation of leaching methods

Soil washing offers a permanent remediation alternative for metal polluted sites. In addition, the washed out metals can be recovered from the leachate and re-introduced into the social material cycle instead of landfilled. In this paper, soil, bark and bark-ash washing was tested on four different metal polluted soil and bark samples from hotspots at former industrial sites. Six different leaching agents; HCl, NH4Cl, lactic acid, EDDS and two acidic process waters from solid waste incineration, were tested, discussed and evaluated. For the soil washing processes, the final pH in the leachate strongly influences the metal leachability. The results show that a pH < 2 is needed to achieve a high leaching yield, while <50 w% of most metals were leached when the pH was higher than 2 or below 10. The acidic process waste waters were generally the most efficient at leaching metals from all the samples studied, and as much as 90-100 w% of the Cu was released from some samples. Initial experiments show that from one of these un-purified leachates, Cu metal (>99% purity) could be recovered. After a single leaching step, the metal contents of the soil residues still exceed the maximum limits according to the Swedish guidelines. An additional washing step is needed to reduce the contents of easy soluble metal compounds in the soil residues. The overall results from this study show that soil and bark-ash washing followed by metal recovery is a promising on-site permanent alternative to remediate metal polluted soils and to utilize non-used metal resources.

Copper/zinc and copper/selenium ratios, and oxidative stress as biochemical markers in recurrent aphthous stomatitis

PROJECT

Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae, and oxidative stress presumably contributes to its pathogenesis. The aim of this study is to scrutinize the relationship between oxidative stress and serum trace elements (copper, Cu; zinc, Zn; selenium, Se), and to evaluate the ratios of Cu/Zn and Cu/Se in this disorder.

PROCEDURE

Patients with RAS (n = 33) and age- and sex-matched healthy control subjects (n = 30) were enrolled in this study. Malondialdehyde (MDA) concentrations in plasma and the activities of superoxide dismutase (SOD1; CuZnSOD), glutathione peroxidase (GPx) and catalase (CAT) in erythrocyte were determined as spectrophotometric. Also, the levels of Se, Zn and Cu in serum were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction.

RESULTS AND CONCLUSIONS

Oxidative stress was confirmed by the significant elevation in plasma MDA, and by the significant decrease in CAT, SOD1, and GPx (p < 0.05). When compared to controls, Zn and Se levels were significantly lower in patients, whereas Cu levels was higher in RAS patients than those in controls (p < 0.05). In addition, the correlation results of this study were firstly shown that there were significant and positive correlations between Se-CAT, Se-GPx, and Cu-MDA parameters, but negative correlations between Se-Cu, Se-MDA, Cu-CAT, Cu-SOD1 and Cu-GPx parameters in RAS patients. Furthermore, the ratios of Cu/Zn and Cu/Se were significantly higher in the patients than the control subjects (p < 0.05). Our results indicated that lipid peroxidation associated with the imbalance of the trace elements seems to play a crucial role in the pathogenesis of RAS. Furthermore, the serum Cu/Zn and Cu/Se ratios may be used as biochemical markers in these patients.

Effects of Zn²⁺ and Cu²⁺ on loach ovaries and ova development

This study compared the accumulation of Zn²⁺ and Cu²⁺ in the ovaries and ova of loaches under different concentrations of Zn²⁺ (1.00, 2.50 and 5.00 mg/L respectively) and Cu²⁺ (0.10, 0.25 and 0.50 mg/L respectively). The results showed that both Zn²⁺ and Cu²⁺ accumulated in the ovaries, and that the relationship between accumulation and time was linear over 20 days of exposure. The accumulation of the metals in ovaries was closely related to the concentration of exposure in the solutions (P<0.05), and was obviously affected by the time and doses. However, the Cu²⁺ concentration was significantly higher than Zn²⁺ (P<0.05). The development level of ova in the ovaries also correlated with the concentration and exposure period in the Zn²⁺ and Cu²⁺ solutions. This study compared the accumulation of Zn²⁺and Cu²⁺ in the ovaries and ova of loaches under different concentrations of Zn²⁺ (1.00, 2.50 and 5.00 mg/L respectively) and Cu²⁺ (0.10, 0.25 and 0.50 mg/L respectively). The results showed that both Zn²⁺ and Cu²⁺ accumulated in the ovaries, and that the relationship between accumulation and time was linear over 20 days of exposure. The accumulation of the metals in ovaries was closely related to the concentration of exposure in the solutions (P<0.05), and was obviously affected by the time and doses. However, the Cu²⁺ concentration was significantly higher than Zn²⁺(P<0.05). The development level of ova in the ovaries also correlated with the concentration and exposure period in the Zn²⁺ and Cu²⁺ solutions.

Trace elements (copper, zinc, selenium and molybdenum) as markers in oral sub mucous fibrosis and oral squamous cell carcinoma

Oral cancer is a major cause of cancer morbidity and mortality worldwide and is prevalent in most areas where tobacco related practices are observed. Essential elements play a role in many biochemical reactions as a micro-source and there is growing evidence that their concentrations are altered on the onset and progress of malignant disease. In this study the levels of copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) in serum of patients with oral sub mucous fibrosis (OSMF) (n = 30) and oral squamous cell carcinoma (OSCC) (n = 30); were determined and the alterations of these critical parameters were analyzed in comparison with controls (n = 30) to identify predictors amongst these parameters for disease occurrence and progression. The serum Cu and Zn were established using Flame Atomic Absorption Spectrometry. Serum estimation of Se and Mo was done by graphite furnace atomic absorption spectrometry (GFAAS). Data analysis revealed a marked, progressive and significant increase in Cu levels in precancer (OSMF) and cancer (OSCC) groups as compared to the normal group. The level of Zn in serum was slightly elevated in OSMF and OSCC though not statistically significant. Cu/Zn ratio was slightly but not significantly elevated. Serum levels of Se and Mo were significantly decreased in the precancer and cancer groups as compared to the normals.

Chemical constituents of fine particulate air pollution and pulmonary function in healthy adults: the Healthy Volunteer Natural Relocation study

The study examined the associations of 32 chemical constituents of particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅) with pulmonary function in a panel of 21 college students. Study subjects relocated from a suburban area to an urban area with changing ambient air pollution levels and contents in Beijing, China, and provided daily morning/evening peak expiratory flow (PEF) and forced expiratory volume in 1s (FEV₂₁) measurements over 6 months in three study periods. There were significant reductions in evening PEF and morning/evening FEV₂₁ associated with various air pollutants and PM₂.₅ constituents. Four PM₂.₅ constituents (copper, cadmium, arsenic and stannum) were found to be most consistently associated with the reductions in these pulmonary function measures. These findings provide clues for the respiratory effects of specific particulate chemical constituents in the context of urban air pollution.

Fifty years since the first European synchrotron-radiation-derived XAFS spectrum (Frascati, 1963)

The first absorption spectra recorded in Europe using synchrotron radiation as the X-ray source were the K-edge of Al and the LIII-edge of Cu taken at Frascati electron synchrotron in May 1963 by the French-Italian group comprised of Y. Cauchois, C. Bonnelle and G. Missoni.

C-terminals in the mouse branchiomotor nuclei originate from the magnocellular reticular formation

Large cholinergic synaptic boutons called "C-terminals" contact motoneurons and regulate their excitability. C-terminals in the spinal somatic motor nuclei originate from cholinergic interneurons in laminae VII and X that express a transcription factor Pitx2. Cranial motor nuclei contain another type of motoneuron: branchiomotor neurons. Although branchiomotor neurons receive abundant C-terminal projections, the neural source of these C-terminals remains unknown. In the present study, we first examined whether cholinergic neurons express Pitx2 in the reticular formation of the adult mouse brainstem, as in the spinal cord. Although Pitx2-positive cholinergic neurons were observed in the magnocellular reticular formation and region around the central canal in the caudal medulla, none was present more rostrally in the brainstem tegmentum. We next explored the origin of C-terminals in the branchiomotor nuclei by using biotinylated dextran amine (BDA). BDA injections into the magnocellular reticular formation of the medulla and pons resulted in the labeling of numerous C-terminals in the branchiomotor nuclei: the ambiguous, facial, and trigeminal motor nuclei. Our results revealed that the origins of C-terminals in the branchiomotor nuclei are cholinergic neurons in the magnocellular reticular formation not only in the caudal medulla, but also at more rostral levels of the brainstem, which lacks Pitx2-positive neurons.

Inhibitory effect of α-lipoic acid on thioacetamide-induced tumor promotion through suppression of inflammatory cell responses in a two-stage hepatocarcinogenesis model in rats

To investigate the protective effect of α-lipoic acid (a-LA) on the hepatocarcinogenic process promoted by thioacetamide (TAA), we used a two-stage liver carcinogenesis model in N-diethylnitrosamine (DEN)-initiated and TAA-promoted rats. We examined the modifying effect of co-administered a-LA on the liver tissue environment surrounding preneoplastic hepatocellular lesions, with particular focus on hepatic macrophages and the mechanism behind the decrease in apoptosis of cells surrounding preneoplastic hepatocellular lesions during the early stages of hepatocellular tumor promotion. TAA increased the number and area of glutathione S-transferase placental form (GST-P)(+) liver cell foci and the numbers of proliferating and apoptotic cells in the liver. Co-administration with a-LA suppressed these effects. TAA also increased the numbers of ED2(+), cyclooxygenase-2(+), and heme oxygenase-1(+) hepatic macrophages as well as the number of CD3(+) lymphocytes. These effects were also suppressed by a-LA. Transcript levels of some inflammation-related genes were upregulated by TAA and downregulated by a-LA in real-time RT-PCR analysis. Outside the GST-P(+) foci, a-LA reduced the numbers of apoptotic cells, active caspase-8(+) cells and death receptor (DR)-5(+) cells. These results suggest that hepatic macrophages producing proinflammatory factors may be activated in TAA-induced tumor promotion. a-LA may suppress tumor-promoting activity by suppressing the activation of these macrophages and the subsequent inflammatory responses. Furthermore, a-LA may suppress tumor-promoting activity by suppressing the DR5-mediated extrinsic pathway of apoptosis and the subsequent regeneration of liver cells outside GST-P(+) foci.

Plasma leptin inhibits the response of nucleus of the solitary tract neurons to aortic baroreceptor stimulation

Leptin receptors have been identified within the nucleus of the solitary tract (NTS) and leptin injections into the caudal NTS inhibit the baroreceptor reflex. However, whether plasma leptin alters the discharge of NTS neurons mediating aortic baroreceptor reflex activity is not known. A series of electrophysiological single unit recording experiments was done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar and Zucker obese rat with either their neuroaxis intact or with mid-collicular transections. Single units in NTS antidromically activated by electrical stimulation of depressor sites in the caudal ventrolateral medulla (CVLM) were found to display a cardiac cycle-related rhythmicity. These units were tested for their responses to stimulation of the aortic depressor nerve (ADN) and intra-carotid injections of leptin (50-200ng/0.1ml). Of 63 single units tested in NTS, 33 were antidromically activated by stimulation of CVLM depressor sites and 18 of these single units responded with a decrease in discharge rate after intracarotid injections of leptin. Thirteen of these leptin responsive neurons (∼72%) were excited by ADN stimulation. Furthermore, the excitatory response of these single units to ADN stimulation was attenuated by about 50% after the intracarotid leptin injection. Intracarotid injections of leptin (200ng/0.1ml) in the Zucker obese rat did not alter the discharge rate of NTS-CVLM projecting neurons. These data suggest that leptin exerts a modulatory effect on brainstem neuronal circuits that control cardiovascular responses elicited during the reflex activation of arterial baroreceptors.

Heavy metals in agricultural soils and crops and their health risks in Swat District, northern Pakistan

This study assessed the concentrations of heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and zinc (Zn) in agricultural soils and crops (fruits, grains and vegetable) and their possible human health risk in Swat District, northern Pakistan. Cd concentration was found higher than the limit (0.05 mg/kg) set by world health organization in 95% fruit and 100% vegetable samples. Moreover, the concentrations of Cr, Cu, Mn, Ni and Zn in the soils were shown significant correlations with those in the crops. The metal transfer factor (MTF) was found highest for Cd followed by Cr>Ni>Zn>Cu>Mn, while the health risk assessment revealed that there was no health risk for most of the heavy metals except Cd, which showed a high level of health risk index (HRI⩾10E-1) that would pose a potential health risk to the consumers.

Protective effect of zinc supplementation against cadmium-induced oxidative stress and the RANK/RANKL/OPG system imbalance in the bone tissue of rats

It was investigated whether protective influence of zinc (Zn) against cadmium (Cd)-induced disorders in bone metabolism may be related to its antioxidative properties and impact on the receptor activator of nuclear factor (NF)-κΒ (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system. Numerous indices of oxidative/antioxidative status, and Cd and Zn were determined in the distal femur of the rats administered Zn (30 and 60mg/l) or/and Cd (5 and 50mg/l) for 6months. Soluble RANKL (sRANKL) and OPG were measured in the bone and serum. Zn supplementation importantly protected from Cd-induced oxidative stress preventing protein, DNA, and lipid oxidation in the bone. Moreover, Zn protected from the Cd-induced increase in sRANKL concentration and the sRANKL/OPG ratio, and decrease in OPG concentration in the bone and serum. Numerous correlations were noted between indices of the oxidative/antioxidative bone status, concentrations of sRANKL and OPG in the bone and serum, as well as the bone concentrations of Zn and Cd, and previously reported by us in these animals (Brzóska et al., 2007) indices of bone turnover and bone mineral density. The results allow us to conclude that the ability of Zn to prevent from oxidative stress and the RANK/RANKL/OPG system imbalance may be implicated in the mechanisms of its protective impact against Cd-induced bone damage. This paper is the first report from an in vivo study providing evidence that beneficial Zn impact on the skeleton under exposure to Cd is related to the improvement of the bone tissue oxidative/antioxidative status and mediating the RANK/RANKL/OPG system.

Simple Preparation of Novel Metal-Containing Mesoporous Starches

Metal-containing mesoporous starches have been synthesized using a simple and efficient microwave-assisted methodology followed by metal impregnation in the porous gel network. Final materials exhibited surface areas >60 m² g-1, being essentially mesoporous with pore sizes in the 10-15 nm range with some developed inter-particular mesoporosity. These materials characterized by several techniques including XRD, SEM, TG/DTA and DRIFTs may find promising catalytic applications due to the presence of (hydr)oxides in their composition.

THE EFFECTS OF IRON AND COPPER AVAILABILITY ON THE COPPER STOICHIOMETRY OF MARINE PHYTOPLANKTON(1)

We studied the interactive effects of iron (Fe) and copper (Cu) availability on the growth rates, Cu quotas, and steady-state Cu-uptake rates (ρss Cu) of 12 phytoplankton (from four classes and two marine environments). A mixed-effect statistical model indicated that low Fe significantly decreased phytoplankton growth rates. In contrast, lowering Cu levels only decreased the growth rates of the oceanic phytoplankton. Under Fe/Cu sufficiency, the Cu quotas ranged from 0.36 to 3.8 μmol Cu · mol(-1) C. Copper levels in the growth medium had a significant positive effect on the Cu quotas, and this effect was dependent on the algal class. Under Fe/Cu sufficiency, the highest average Cu quotas were observed for the Bacillariophyceae, followed by the Cyanophyceae, Prymnesiophyceae, and lastly the Dinophyceae. Similar taxonomic trends were observed for the ρss Cu. Although the Cu:C ratios were not significantly higher in oceanic strains, there are five independent lines of evidence supporting a more important role of Cu in the physiology of the oceanic phytoplankton. The mixed-effect model indicated a significant Cu effect on the growth rates and ρss Cu of the oceanic strains, but not the coastal strains. In addition, lowering the Cu concentration in the media decreased the Cu quotas and ρss Cu of the oceanic strains to a greater extent (5.5- and 5.4-fold, respectively) than those of the coastals (3.8- and 4.7-fold, respectively). Iron limitation only had a significant effect on the Cu quotas of the oceanic strains, and this effect was dependent on Cu level and taxonomic class. Our results highlight a complex physiological interaction between Fe and Cu in marine phytoplankton.

Analysis of plasma zinc and copper concentration, and perceived symptoms, in individuals with depression, post zinc and anti-oxidant therapy

AIM

To assess plasma Zn and Cu levels in individuals with depression.

SUBJECTS AND METHODS

Plasma from 73 clinically depressed individuals, 38 individuals with anxiety and 16 controls were tested for plasma Zn and Cu concentration using inductively-coupled plasma-mass spectrometry.

RESULTS

Depressed individuals, with and without secondary anxiety, had decreased plasma Zn and elevated plasma Cu compared to controls. Zn normalized (increased to the level of normal controls) but Cu increased in individuals with depression (with and without secondary anxiety), after Zn therapy, whereas both plasma Zn increased and Cu levels decreased in anxiety, with and without secondary depression, after Zn therapy. Individuals with depression,with and without secondary anxiety, had significantly higher symptom severity when compared to neurotypical controls. Symptom severity in individuals with anxiety (both with and without secondary depression) significantly decreased after Zn therapy, whereas symptoms remained the same in individuals with primary depression.

DISCUSSION

These data show an association between Zn and Cu plasma levels and clinically depressed individuals, and suggest that high Cu levels are associated with high symptom severity.

Evaluation of serum levels of zinc, copper, iron, and zinc/copper ratio in cutaneous leishmaniasis

BACKGROUND

The purpose of this study was to evaluate the levels of zinc (Zn), copper (Cu), iron (Fe) and zinc/ copper ratio in the serum of patients with cutaneous leishmaniasis in Qom Province, center of Iran.

METHODS

Serum levels of zinc and copper were determined by flame atomic absorption spectrophotometer and serum iron concentration was measured by using an Auto Analyzer. The study group consisted of 60 patients with cutaneous leishmaniasis and the control group of 100 healthy volunteers from the same area who were not exposed to cutaneous leishmaniasis.

RESULT

There were no statistically significant differences in age and body mass index between the two groups. Serum Zn (P< 0.001) and Fe (P< 0.05) levels were lower in patients with cutaneous leishmaniasis than the control group. We also found serum Cu concentration (P< 0.05) in the patient group was significantly higher than that of the control group. However, zinc/ copper ratio (P< 0.001) was lower in patients with cutaneous leishmaniasis than in the control group.

CONCLUSION

Our data indicated that Zn/Cu ratio was significantly lower in patients with CL as compared to the controls. Earlier reports suggest that, this ratio imbalance could be a useful marker for immune dysfunction in leishmaniasis. There was also strong association of Zn, Cu and Fe with CL. It suggests the use of blood zinc, copper, iron concentration and the copper/zinc ratio (Zn/Cu), as a means for estimating the prognosis of CL.

Phylogenetic variation in heavy metal accumulation in angiosperms

•  The influence of phylogeny on shoot heavy metal content in plants was investigated and the hypothesis tested that traits impacting on the accumulation of cadmium, chromium, copper, nickel, lead and zinc in plant shoots are associated. •  Data suitable for comparative analyses were generated from a literature survey, using a residual maximum likelihood (REML) procedure. Both pair-wise regressions and principal components analyses (PCA) were performed on independent contrasts of shoot metal content. •  Significant variation in shoot metal content occurred at the classification level of order and above, suggesting an ancient evolution of traits. Traits impacting on the accumulation of metals in plant shoots were associated. •  This information can be used to improve predictions of soil-to-plant metal transfer, to formulate hypotheses on the origins of metal-accumulating phenotypes and to inform the exploitation of plant genetic resources for nutritional improvement and phytoremediation.